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| Curr Opin Microbiol, 1998 Apr, 1(2), 170 - 4 Initiation of bacterial development; Hoch JA; The discovery of a mitotic apparatus in bacteria has led to significant recent progress being made in understanding the regulatory connections between the cell cycle, chromosome segregation and the onset of developmental processes in sporulation . The control of developmental transcription by antagonism between protein kinase and protein phosphatase reached a new level of complexity with the discovery of peptide inhibitors of protein phosphatases that cycle between the interior and exterior cell surface as information messengers . New mechanisms of developmental regulation are being uncovered in a variety of microbial systems. Curr Opin Microbiol, 1998 Feb, 1(1), 12 - 6 Microbial genome sequencing and pathogenesis; Tang CM et al.; The year 1997 saw the publication of the complete nucleotide sequence of Helicobacter pylori and Escherichia coli . It is conceivable that the complete nucleotide sequence for all the major human bacterial pathogens will be available by the end of the century . Database alignments have been used to ascribe the putative functions of open reading frames in the sequenced isolates and to define the differences between bacterial species at the nucleotide level . The most striking finding from all genome projects has been the high proportion of open reading frames that have no known function . Experimental data demonstrating the utility of the genome sequencing projects are only just beginning to emerge. J Anim Sci, 1999 Jan, 77(1), 187 - 93 Mechanical maceration of alfalfa; Hintz RW et al.; Maceration is an intensive forage-conditioning process that can increase field drying rates by as much as 300% . Because maceration shreds the forage and reduces its rigidity, improvements in bulk density, silage compaction, and ensiling characteristics have been observed . Macerating forage also increases the surface area available for microbial attachment in the rumen, thereby increasing forage digestibility and animal performance . Feeding trials with sheep have shown increases in DMI of 5 to 31% and increases in DM digestibility of from 14 to 16 percentage units . Lactation studies have demonstrated increases in milk production and BW gain for lactating Holstein cows; however, there is a consistent decrease in milk fat percentage when dairy cattle are fed macerated forage . In vitro studies have shown that maceration decreases lag time associated with NDF digestion and increases rate of NDF digestion . In situ digestibility studies have shown that maceration increases the size of the instantly soluble DM pool and decreases lag time associated with NDF digestion, but it may not consistently alter the rate or extent of DM and NDF digestion. Sci Total Environ, 1999 Jan 26, 225(3), 181 - 209 Natural and anthropogenic inputs of hydrocarbons to the Strait of Georgia; Yunker MB et al.; Sediment cores from the Fraser estuary, Vancouver Harbour and Strait of Georgia, suspended sediment samples from the Fraser River and sediment grabs from Vancouver Harbour have been analyzed for alkanes and parent and alkyl PAHs (polycyclic aromatic hydrocarbons) . Principal components analysis (PCA) clearly distinguishes mixed sources by separating parent PAHs according to molecular size, and separating alkyl substituted PAHs from higher plant PAHs . We find the Fraser River to be the predominant source for natural and anthropogenic hydrocarbons to the Strait of Georgia . The natural hydrocarbon burden from the Fraser River is augmented principally by petroleum hydrocarbons and combustion PAHs from Vancouver . Contaminated sediments from Vancouver Harbour very likely have also been transported to a major ocean disposal site off the Fraser estuary . Petroleum alkanes, which dominate Fraser River suspended sediment samples, are lost by processes such as dissolution or microbial degradation during transport and sedimentation, while PAHs from the river are delivered essentially unchanged to sediments in the strait . Hydrocarbon composition undergoes little change with depth at a reference location in the Strait of Georgia, indicating that PAH inputs have changed very little since the early part of this century . In Vancouver Harbour the low rate of sediment accumulation coupled with surface mixing has led to the retention of contaminant PAHs within the surface mixed layer, while the rapid delivery of sediments from the Fraser River has buried contaminant PAHs from historical ocean disposal in the Strait of Georgia. Proc Natl Acad Sci U S A, 1999 Mar 2, 96(5), 2373 - 8 Induction of autoantibodies to mouse CCR5 with recombinant papillomavirus particles; Chackerian B et al.; The vertebrate immune system has evolved to respond vigorously to microbial infection but to ignore self-antigens . Evidence has emerged that B cell responses to viruses are initiated by immune recognition of ordered arrays of antigen on the viral surface . To test whether autoantibodies against a self-antigen can be induced by placing it in a context that mimics the ordered surface of a viral particle, a peptide representing an extracellular loop of the mouse chemokine receptor CCR5 was incorporated into an immunodominant site of the bovine papillomavirus virus L1 coat protein, which self-assembles into virus-like particles . Mice inoculated with chimeric L1-CCR5 particles generated autoantibodies that bound to native mouse CCR5, inhibited binding of its ligand RANTES, and blocked HIV-1 infection of an indicator cell line expressing a human-mouse CCR5 chimera . These results suggest a general method for inducing autoantibodies against self-antigens, with diverse potential basic research and clinical applications. Proc Natl Acad Sci U S A, 1999 Mar 2, 96(5), 2204 - 9 Yeast and human genes that affect the Escherichia coli SOS response; Perkins EL et al.; The sequencing of the human genome has led to the identification of many genes whose functions remain to be determined . Because of conservation of genetic function, microbial systems have often been used for identification and characterization of human genes . We have investigated the use of the Escherichia coli SOS induction assay as a screen for yeast and human genes that might play a role in DNA metabolism and/or in genome stability . The SOS system has previously been used to analyze bacterial and viral genes that directly modify DNA . An initial screen of meiotically expressed yeast genes revealed several genes associated with chromosome metabolism (e.g., RAD51 and HHT1 as well as others) . The SOS induction assay was then extended to the isolation of human genes . Several known human genes involved in DNA metabolism, such as the Ku70 end-binding protein and DNA ligase IV, were identified, as well as a large number of previously unknown genes . Thus, the SOS assay can be used to identify and characterize human genes, many of which may participate in chromosome metabolism. Appl Environ Microbiol, 1999 Mar, 65(3), 1251 - 8 Identification of a novel group of bacteria in sludge from a deteriorated biological phosphorus removal reactor; Nielsen AT et al.; The microbial diversity of a deteriorated biological phosphorus removal reactor was investigated by methods not requiring direct cultivation . The reactor was fed with media containing acetate and high levels of phosphate (P/C weight ratio, 8:100) but failed to completely remove phosphate in the effluent and showed very limited biological phosphorus removal activity . Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA was used to investigate the bacterial diversity . Up to 11 DGGE bands representing at least 11 different sequence types were observed; DNA from the 6 most dominant of these bands was further isolated and sequenced . Comparative phylogenetic analysis of the partial 16S rRNA sequences suggested that one sequence type was affiliated with the alpha subclass of the Proteobacteria, one was associated with the Legionella group of the gamma subclass of the Proteobacteria, and the remaining four formed a novel group of the gamma subclass of the Proteobacteria with no close relationship to any previously described species . The novel group represented approximately 75% of the PCR-amplified DNA, based on the DGGE band intensities . Two oligonucleotide rRNA probes for this novel group were designed and used in a whole-cell hybridization analysis to investigate the abundance of this novel group in situ . The bacteria were coccoid and 3 to 4 microm in diameter and represented approximately 35% of the total population, suggesting a relatively close agreement with the results obtained by the PCR-based DGGE method . Further, based on electron microscopy and standard staining microscopic analysis, this novel group was able to accumulate granule inclusions, possibly consisting of polyhydroxyalkanoate, inside the cells. Adv Parasitol, 1999, 42, 343 - 410 DNA vaccines: technology and application as anti-parasite and anti-microbial agents; Alarcon JB et al.; DNA vaccines have been termed The Third Generation of Vaccines . The recent successful immunization of experimental animals against a range of infectious agents and several tumour models of disease with plasmid DNA testifies to the powerful nature of this revolutionary approach in vaccinology . Among numerous advantages, a major attraction of DNA vaccines over conventional vaccines is that they are able to induce protective cytotoxic T-cell responses as well as helper T-cell and humoral immunity . Here we review the current state of nucleic acid vaccines and cover a wide range of topics including delivery mechanisms, uptake and expression of plasmid DNA, and the types of immune responses generated . Further, we discuss safety issues, and document the use of nucleic acid vaccines against viral, bacterial and parasitic diseases, and cancer . The early potential promise of DNA vaccination has been fully substantiated with recent, exciting developments including the movement from testing DNA vaccines in laboratory models to non-human primates and initial human clinical trials . These advances and the emerging voluminous literature on DNA vaccines highlight the rapid progress that has been made in the DNA immunization field . It will be of considerable interest to see whether the progress and optimism currently prevailing can be maintained, and whether the approach can indeed fulfil the medical and commerical promise anticipated. PDA J Pharm Sci Technol, 1998 Nov-Dec, 52(6), 326 - 30 Statistical analysis of environmental monitoring data: does a worst case time for monitoring clean rooms exist? Cundell AM, Bean R, Massimore L, Maier C. To determine the relationship between the sampling time of the environmental monitoring, i.e., viable counts, in aseptic filling areas and the microbial count and frequency of alerts for air, surface and personnel microbial monitoring, statistical analyses were conducted on 1) the frequency of alerts versus the time of day for routine environmental sampling conducted in calendar year 1994, and 2) environmental monitoring data collected at 30-minute intervals during routine aseptic filling operations over two separate days in four different clean rooms with multiple shifts and equipment set-ups at a parenteral manufacturing facility . Statistical analyses showed, except for one floor location that had significantly higher number of counts but no alert or action level samplings in the first two hours of operation, there was no relationship between the number of counts and the time of sampling . Further studies over a 30-day period at the floor location showed no relationship between time of sampling and microbial counts . The conclusion reached in the study was that there is no worst case time for environmental monitoring at that facility and that sampling any time during the aseptic filling operation will give a satisfactory measure of the microbial cleanliness in the clean room during the set-up and aseptic filling operation. Appl Environ Microbiol, 1999 Mar, 65(3), 982 - 8 Effect of phenylurea herbicides on soil microbial communities estimated by analysis of 16S rRNA gene fingerprints and community-level physiological profiles; el Fantroussi S et al.; The effect of three phenyl urea herbicides (diuron, linuron, and chlorotoluron) on soil microbial communities was studied by using soil samples with a 10-year history of treatment . Denaturing gradient gel electrophoresis (DGGE) was used for the analysis of 16S rRNA genes (16S rDNA) . The degree of similarity between the 16S rDNA profiles of the communities was quantified by numerically analysing the DGGE band patterns . Similarity dendrograms showed that the microbial community structures of the herbicide-treated and nontreated soils were significantly different . Moreover, the bacterial diversity seemed to decrease in soils treated with urea herbicides, and sequence determination of several DGGE fragments showed that the most affected species in the soils treated with diuron and linuron belonged to an uncultivated bacterial group . As well as the 16S rDNA fingerprints, the substrate utilization patterns of the microbial communities were compared . Principal-component analysis performed on BIOLOG data showed that the functional abilities of the soil microbial communities were altered by the application of the herbicides . In addition, enrichment cultures of the different soils in medium with the urea herbicides as the sole carbon and nitrogen source showed that there was no difference between treated and nontreated soil in the rate of transformation of diuron and chlorotoluron but that there was a strong difference in the case of linuron . In the enrichment cultures with linuron-treated soil, linuron disappeared completely after 1 week whereas no significant transformation was observed in cultures inoculated with nontreated soil even after 4 weeks . In conclusion, this study showed that both the structure and metabolic potential of soil microbial communities were clearly affected by a long-term application of urea herbicides. J Clin Periodontol, 1999 Feb, 26(2), 113 - 23 Etiologic models for incident periodontal attachment loss in older adults; Elter JR et al.; Etiologic factors for incident periodontal attachment loss (ALOSS) have not been conclusively identified . The purpose of this study was to develop etiologic models for ALOSS in older adults . Data on 697 older blacks and whites were obtained from 5 sequential examinations over 7 years in the Piedmont 65+ dental study, a complex random sample of older adults in North Carolina . Multivariable Poisson regression models were fit for average number of ALOSS events per person or site month at risk . In models for whites, molar sites, sites with adjacent caries, sites in persons who had: Porphyromonas gingivalis (P.g.) at least 2% of total microbial count (TMC), never had a dental checkup, more depression symptoms, fewer than 12 years of education, higher BANA score, or smoked, had significantly higher rates of ALOSS . In a separate model for blacks, interproximal and molar sites, sites in blacks who had: P.g . at least 2% of TMC, higher BANA score, never had a dental checkup, lower socioeconomic status (SES), or smoked, had significantly higher rates of ALOSS . These results confirm a multifactorial etiology for ALOSS in older adults and indicate that interventions aimed at infection, smoking, and preventive dental care utilization, may be most useful. Arch Bronconeumol, 1999 Jan, 35(1), 27 - 32 {Community-acquired pneumonia referred for hospital management . Its epidemiology and the diagnostic and therapeutic approaches}; Carretero Gracia JA et al.; OBJECTIVES: To determine the epidemiology of community-acquired pneumonia referred to the hospital and to characterize the diagnostic and therapeutic approach adopted by physicians . METHOD: Retrospective epidemiological and descriptive clinical study based on case histories consistent with a diagnosis of community-acquired pneumonia (Fang et al . Medicine, 1990; 69:307-16) of patients referred to hospitals in Soria (Spain) over a period of one year . The patients were grouped by severity and the presence of risk factors for unusual etiology . Initial approaches were compared to those advocated by various sources . RESULTS: Three hundred eight cases of community-acquired pneumonia were diagnosed, and 82% of the patients were admitted . Mean age was 68 +/- 26 years (43% over 80 years of age) . Men accounted for 56% . Two hundred seventeen patients (70%) were classified as seriously ill, 203 (66%) had risk factors for unusual etiology, and 166 (54%) were classified in both categories . Mortality among admitted patients was 13% . Etiological diagnoses did not correspond to the guidelines of the Spanish Society of Pneumology and Chest Surgery (SEPAR), with microbial identification achieved in 5% . Empirical treatment followed SEPAR guidelines in 45% of the cases . The Mensa guidelines were followed in 23% and the Sanford guidelines in 20% . CONCLUSIONS: The incidence of community-acquired pneumonia in this population is 3.2 cases per 1,000 inhabitants/year . The population is mainly elderly and comorbidity is common, although mortality is low . We believe common criteria should be adopted for managing community-acquired pneumonia and that empirical treatment should be directed toward germs identified in each setting, based on appropriate etiological investigation. Curr Opin Immunol, 1999 Feb, 11(1), 13 - 8 The Toll-receptor family and control of innate immunity; Kopp EB et al.; Innate immune recognition is mediated by a system of germline-encoded receptors that recognize conserved molecular patterns that are associated with microbial pathogens . These receptors are coupled to signal transduction pathways that control expression of a variety of inducible immune-response genes . Toll receptors and the associated signaling pathways of nuclear factor kappaB may represent the most ancient host defense system found in mammals, insects and plants. Nippon Rinsho, 1999 Jan, 57(1), 43 - 52 {Characteristics of anti-microbial agents and its clinical choice for H . pylori treatment}; Aoyama N et al.; Eradication of Helicobacter pylori (H . pylori) is now established as main treatment of upper-gastrointestinal diseases . Resistance to H . pylori and acid condition in the stomach were important factors which influenced H . pylori eradication . Recolonized H . pylori strains will be easily resistant to metronidazole and clarithromycin, whereas almost all of H . pylori strains are sensitive to amoxicillin . On the other hand, amoxicillin targets cell wall biosynthesis and clarithromycin inhibits protein synthesis of Helicobacter pylori mainly in the growth phase which induced high intragastric pH condition, however, metronidazole targets DNA and, therefore, is independent of the stationary or growth phase distribution . To established a optimal regimen for Helicobacter pylori treatment, several factors included them should be account according to the parmacokinetical standings. Int Rev Immunol, 1998, 17(5-6), 339 - 63 T cell receptor repertoire in rheumatoid arthritis; Goronzy JJ et al.; CD4+ T cells are a major component of the inflammatory infiltrate in rheumatoid synovitis . Within synovial lesions, clonal CD4+ T cell populations are detectable, supporting the notion of an antigen specific recognition even in the joint . In general, the clonal size of individual T cell clones is small and does not lead to a marked distortion of the synovial T cell receptor (TCR) repertoire . Comparison of TCR sequences derived from different patients has not provided evidence for common sequences . Either multiple antigens are recognized or the TCR repertoire is sufficiently plastic with a multitude of different TCR structures responding to the same antigen(s) . However, within one individual, the repertoire of clonal T cell populations is restricted . Identical T cell clones can be identified in different joints and at different timepoints of the disease, emphasizing that the spectrum of antigens recognized is conserved over time and that the T cell response pattern is not subject to evolution . Characterization of antigens involved in the latter stages of the disease may thus provide critical information on disease-initiating events . Recent data have led to the new concept that the role of T cells in rheumatoid arthritis (RA) is not limited to synovial inflammation . Evidence has been provided that the premorbid TCR repertoires of RA patients and normal controls can be distinguished . The T cell repertoire in RA patients is prone to recognize certain microbial products and autoantigens . The selection of this response pattern can only partially be attributed to the disease associated HLA-DRB1 alleles . Additional factors common in RA patients but not in HLA-DR matched control individuals seem to be important in shaping the TCR repertoire . Furthermore, the repertoire of mature T cells in RA patients is characterized by oligoclonality which involves T cells in the peripheral blood compartment . Possibly, these clonal T cell populations react to widespread autoantigens, raising the possibility that RA patients have a defect in controlling peripheral tolerance and an anomaly of lymphoproliferation . In contrast to joint residing CD4+ T cells, expanded clonotypes isolated from the blood of different patients have been described to share TCR beta chain structures . How these characteristic features of the global TCR repertoire in RA patients translate into mechanisms of disease remains to be elucidated. Biol Res, 1998, 31(4), 329 - 38 Is there a mucosal immune system associated with the mammalian oviduct? Cardenas H, Corvalan L, Imarai M. The oviduct is a key component of the reproductive system where essential states such as spermatozoa capacitation, fertilization and early embryo development take place . Recently, an additional role for the entire female reproductive tract has emerged with important implications for our understanding and management of reproductive health, namely, its role in mounting local immune responses against microbial pathogens . Most of the evidence about mucosal immune responses in the female reproductive tract is related to the vagina, with less information available for the uterus . The less known segment in this regard is the oviduct, which prompted us to review and summarize the current state of knowledge on the immune system at the level of the mammalian oviduct . A comprehensive search was conducted in Medline and--for the last two years--also in Current Contents . Result demonstrate that the mammalian oviduct is endowed with many of the elements that characterize a mucosal immune system . However, there are gaps in our knowledge that, in addition to important interspecies differences, make it essential to explore further some fundamental questions regarding this system. J Gastroenterol Hepatol, 1999 Jan, 14(1), 32 - 8 Optimal treatment for duodenal ulcer disease: a cost-decision analysis in Malaysian patients; Goh KL et al.; The aim of the present study was to determine the cost-efficiency of different duodenal ulcer disease treatment practices in Malaysia . Six Malaysian gastroenterologists met to discuss the direct costs related to Helicobacter pylori (HP) eradication treatment . Five treatment strategies were compared: (i) histamine H2 receptor antagonists (H2RA), acid suppression therapy for 6 weeks followed by maintenance therapy as needed; (ii) bismuth triple + proton pump inhibitor (PPI), bismuth (120 mg, q.i.d.), metronidazole (400 mg; t.i.d.), tetracycline (500 mg, q.i.d.) for 7 days and PPI, b.i.d., for 7 days; (iii) OAC, omeprazole (20 mg, b.i.d.), amoxycillin (1000 mg, b.i.d.) and clarithromycin (500 mg, b.i.d.) for 7 days; (iv) OMC, omeprazole (20mg, b.i.d.), metronidazole (400mg, b.i.d.) and clarithromycin (500 mg, b.i.d.) for 7 days; and (v) OAM, omeprazole (20 mg, b.i.d.), amoxycillin (1000 mg, b.i.d.) and metronidazole (400 mg, b.i.d.) for 7 days . A decision tree model was created to determine which therapy would be the most cost-effective . The model considered eradication rates, resistance to anti-microbial agents, compliance and cost implications of treatment regimens, physician visits and ulcer recurrences during a 1 year time period assumption . The H2RA maintenance therapy was the most expensive treatment at Malaysian Ringgit (MR) 2335, followed by bismuth triple therapy (MR 1839), OMC (MR 1786), OAM (MR 1775) and OAC, being the most cost-effective therapy, at MR 1679 . In conclusion, HP eradication therapy is superior to H2RA maintenance therapy in the treatment of duodenal ulcer disease . Of the HP eradication regimens, OAC is the most cost-effective. Int J Syst Bacteriol, 1999 Jan, 49 Pt 1, 149 - 62 New genus-specific primers for the PCR identification of members of the genera Pseudonocardia and Saccharopolyspora; Moron R et al.; Members of the family Pseudonocardiaceae are difficult to identify on the basis of their micromorphology only . The biochemical characterization of each new isolate is a painstaking and time-consuming task which cannot always be undertaken when handling large numbers of strains as is the case in natural product screening programmes . In this study, two sets of genus-specific oligonucleotides were designed which allow rapid detection of members of the genera Pseudonocardia and Saccharopolyspora by means of PCR-specific amplification . The genus specificity of these primers was validated on a wide range of collection strains and the primers were subsequently used to study a group of 106 wild-type isolates that possessed morphological characteristics of the family . Out of this group, 51 strains could be identified as members of the genus Pseudonocardia and only nine isolates could be assigned to the genus Saccharopolyspora . The diversity indicated by whole-cell fatty acid profiles of both wild-type and reference strains was compared with that identified using the oligonucleotide primers . The partial 16S rDNA sequencing of representative wild-type strains was used to validate their genus assignment by PCR-specific amplification . This study shows the industrial usefulness of the application of these direct identification tools as well as the complementary use of two sources of data, PCR-specific amplification results and fatty acid composition, to assess the diversity of a microbial population. FEBS Lett, 1999 Jan 29, 443(3), 290 - 6 Kinetics of oxidation of aliphatic and aromatic thiols by myeloperoxidase compounds I and II; Burner U et al.; Myeloperoxidase (MPO) is the most abundant protein in neutrophils and plays a central role in microbial killing and inflammatory tissue damage . Because most of the non-steroidal anti-inflammatory drugs and other drugs contain a thiol group, it is necessary to understand how these substrates are oxidized by MPO . We have performed transient kinetic measurements to study the oxidation of 14 aliphatic and aromatic mono- and dithiols by the MPO intermediates, Compound I (k3) and Compound II (k4), using sequential mixing stopped-flow techniques . The one-electron reduction of Compound I by aromatic thiols (e.g . methimidazole, 2-mercaptopurine and 6-mercaptopurine) varied by less than a factor of seven (between 1.39 +/- 0.12 x 10(5) M(-1) s(-1) and 9.16 +/- 1.63 x 10(5) M(-1) s(-1)), whereas reduction by aliphatic thiols was demonstrated to depend on their overall net charge and hydrophobic character and not on the percentage of thiol deprotonation or redox potential . Cysteamine, cysteine methyl ester, cysteine ethyl ester and alpha-lipoic acid showed k3 values comparable to aromatic thiols, whereas a free carboxy group (e.g . cysteine, N-acetylcysteine, glutathione) diminished k3 dramatically . The one-electron reduction of Compound II was far more constrained by the nature of the substrate . Reduction by methimidazole, 2-mercaptopurine and 6-mercaptopurine showed second-order rate constants (k4) of 1.33 +/- 0.08 x 10(5) M(-1) s(-1), 5.25 +/- 0.07 x 10(5) M(-1) s(-1) and 3.03 +/- 0.07 x 10(3) M(-1) s(-1) . Even at high concentrations cysteine, penicillamine and glutathione could not reduce Compound II, whereas cysteamine (4.27 +/- 0.05 x 10(3) M(-1) s(-1)), cysteine methyl ester (8.14 +/- 0.08 x 10(3) M(-1) s(-1)), cysteine ethyl ester (3.76 +/- 0.17 x 10(3) M(-1) s(-1)) and alpha-lipoic acid (4.78 +/- 0.07 x 10(4) M(-1) s(-1)) were demonstrated to reduce Compound II and thus could be expected to be oxidized by MPO without co-substrates. Poult Sci, 1999 Jan, 78(1), 75 - 9 Effects of microbial phytase supplementation on egg production, eggshell quality, and mineral retention of laying hens fed different levels of phosphorus; Um JS et al.; A 20-wk feeding trial (21 to 40 wk of age) was conducted to evaluate the effects of phytase supplementation on egg production, egg quality, nutrient retention, and P excretion of laying hens fed diets containing different levels of P . Nine hundred and sixty ISA Brown hens were randomly allocated to completely randomized block arrangement of four diets: corn-soybean diet (1.4% tricalcium phosphate, TCP) without (T1, control) and with phytase (T2); 0.7% TCP (T3) or 0% TCP (T4) diet with phytase . Dietary microbial phytase was added at a level of 500 U/kg . Both hen-day and hen-housed egg production of T2 were significantly (P < 0.05) higher than other treatments, which were not different among themselves . Egg weights were also significantly (P < 0.05) different among treatments ,with T2 being the highest . Feed consumption of T2 was significantly (P < 0.05) higher than other treatments but feed conversion ratio was not significantly different from others . Specific gravity and shell thickness of the eggs were highest in the control (T1) but eggshell strength and broken egg to total egg ratio were not different among treatments . Haugh units were not different among treatments . Retention of Ca, P, Mg, Fe, and Zn were greater (P < 0.05) in phytase-supplemented groups . There were significant (P < 0.05) differences in excretion of ash, P, and Zn . The excretion of these components were highest in the control, whereas P excretion was significantly lower in the T3 and T4 groups . In conclusion, supplementation of the microbial phytase to normal corn-soybean diet improved egg production and can reduce TCP level in the diet without affecting egg production and egg quality . Significant reduction of P excretion can be also achieved. J Endod, 1998 Oct, 24(10), 659 - 62 Intraorifice sealing of gutta-percha obturated root canals to prevent coronal microleakage; Pisano DM et al.; A study was conducted to evaluate Cavit, Intermediate Restorative Material, and Super-EBA as intraorifice filling materials to prevent coronal microleakage . Root canal instrumentation and obturation was done on 74 extracted single-rooted teeth . Three and one-half millimeters of the gutta-percha was removed from the coronal aspect of the root canal and replaced with one of the three filling materials . The teeth were suspended in scintillation vials containing trypticase soy broth, and human saliva was added to the pulp chambers . Microbial penetration was detected as an increase in turbidity of the broth corresponding to bacterial growth . At the end of 90 days, the results showed that 15% of the Cavit-filled orifices leaked, whereas 35% of the Intermediate Restorative Material and Super-EBA-filled orifices leaked . The gutta-percha obturated root canals that received an intraorifice filling material leaked significantly less than the obturated, unsealed control group--all of which leaked in < 49 days. Genome Res, 1999 Feb, 9(2), 175 - 81 Optical mapping of Plasmodium falciparum chromosome 2; Jing J et al.; Detailed restriction maps of microbial genomes are a valuable resource in genome sequencing studies but are toilsome to construct by contig construction of maps derived from cloned DNA . Analysis of genomic DNA enables large stretches of the genome to be mapped and circumvents library construction and associated cloning artifacts . We used pulsed-field gel electrophoresis purified Plasmodium falciparum chromosome 2 DNA as the starting material for optical mapping, a system for making ordered restriction maps from ensembles of individual DNA molecules . DNA molecules were bound to derivatized glass surfaces, cleaved with NheI or BamHI, and imaged by digital fluorescence microscopy . Large pieces of the chromosome containing ordered DNA restriction fragments were mapped . Maps were assembled from 50 molecules producing an average contig depth of 15 molecules and high-resolution restriction maps covering the entire chromosome . Chromosome 2 was found to be 976 kb by optical mapping with NheI, and 946 kb with BamHI, which compares closely to the published size of 947 kb from large-scale sequencing . The maps were used to further verify assemblies from the plasmid library used for sequencing . Maps generated in silico from the sequence data were compared to the optical mapping data, and good correspondence was found . Such high-resolution restriction maps may become an indispensable resource for large-scale genome sequencing projects. J Pediatr Surg, 1999 Jan, 34(1), 188 - 91; discussion 191-2 Acute chest syndrome in the postoperative sickle cell patient; Delatte SJ et al.; BACKGROUND/PURPOSE: Acute chest syndrome (ACS), a phenomenon of pulmonary sequestration in sickle cell disease (SCD) patients, is frequently missed in the postoperative SCD child . The constellation of symptoms range from fever and respiratory distress to abdominal discomfort . In its most fulminate state, the syndrome has been reported in some series to carry almost a 25% to 50% mortality rate in the postoperative patient . The incidence in pediatric patients in the era of minimally invasive surgery is unknown . METHODS: Since December 1995, 63 episodes of ACS have been documented in the nearly 500 SCD children seen at our institution . Six of 63 episodes occurred within 2 weeks after a surgical procedure under general anesthesia . During this period, 59 operations were performed by the pediatric surgery service on SCD patients with an ACS incidence of 10.2% . Careful review of the preoperative, intraoperative, and postoperative management of these patients was performed . RESULTS: All six received preoperative oxygen saturation monitoring and intravenous fluid (IVF) hydration . One half of these patients required transfusion to achieve a hemoglobin level of greater than 10 mg/dL . Documentation of intraoperative temperature, hypoxia, volume status, and hypercarbia as well as any atypical perioperative events were monitored and reviewed . All patients received postoperative oxygen supplementation and IVF hydration . Onset of ACS ranged from 1 hour to 7 days postoperatively . Only one of six was thought to be of microbial etiology (elevated mycoplasma titers), and all patients received prophylactic antibiotic and aggressive pulmonary therapy . Overall length of hospitalization was increased with an average stay of 6.1 days . There were no postsurgical ACS deaths . CONCLUSIONS: Despite close attention and avoidance of known risk factors for development of postoperative SCD complications, ACS occurred with an incidence much higher than previously reported in the literature (0.4% v 10.2%) . Interestingly, five of six cases were after laparoscopic procedures suggesting that the advantages of laparoscopy, such as reduced postoperative pain, do not extrapolate to decreased incidence of ACS. Biodegradation, 1998, 9(3-4), 301 - 10 Biotechnological possibilities for waste tyre-rubber treatment; Holst O et al.; Every year large amounts of spent rubber material, mainly from rubber tyres, are discarded . Of the annual total global production of rubber material, which amounts to 16-17 million tonnes, approximately 65% is used for the production of tyres . About 250 millions spent car tyres are generated yearly in USA only . This huge amount of waste rubber material is an environmental problem of great concern . Various ways to remediate the problem have been proposed . Among these are road fillings and combustion in kilns . Spent tyres, however, comprise valuable material that could be recycled if a proper technique can be developed . One way of recycling old tyres is to blend ground spent rubber with virgin material followed by vulcanization . The main obstacle to this recycling is bad adhesion between the crumb and matrix of virgin rubber material due to little formation of interfacial sulphur crosslinks . Micro-organisms able to break sulphur-sulphur and sulphur-carbon bonds can be used to devulcanize waste rubber in order to make polymer chains on the surface more flexible and facilitate increased binding upon vulcanization . Several species belonging to both Bacteria and Archaea have this ability . Mainly sulphur oxidizing species, such as different species of the genus Thiobacillus and thermoacidophiles of the order of Sulfolobales, have been studied in this context . The present paper will give a background to the problem and an overview of the biotechnological possibilities for solutions of waste rubber as an environmental problem, focusing on microbial desulphurization. Biodegradation, 1998, 9(3-4), 293 - 300 Technological and economic aspects of coal biodesulfurisation; Klein J; The sulfur found in coal is either part of the molecular coal structure (organically bound sulfur), is contained in minerals such as pyrite (FeS2), or occurs in minor quantities in the form of sulfate and elemental sulfur . When pyrite crystals are finely distributed within the coal matrix, mechanical cleaning can only remove part of the pyrite . It can, however, be removed by microbial action requiring only mild conditions . The process involves simple equipment, almost no chemicals, but relatively long reaction times, and treatment of iron sulfate containing process water . Different process configurations are possible, depending on the coal particle size . Coal with particle sizes of less than 0.5 mm is preferably desulfurised in slurry reactors, while lump coal (> 0.5 mm) should be treated in heaps . Investment and operating costs are estimated for different process configurations on an industrial scale . Concerning the organically bound sulfur in coal there is up to now no promising biochemical pathway for the degradation and/or desulfurisation of such compounds. Biodegradation, 1998, 9(3-4), 201 - 12 Bioenergetics of sulphate-reducing bacteria in relation to their environmental impact; Hamilton WA; The cellular physiology of the sulphate-reducing bacteria, and of other sulphidogenic species, is determined by the energetic requirements consequent upon their respiratory mode of metabolism with sulphate and other oxyanions of sulphur as terminal electron acceptors . As a further consequence of their, relatively, restricted catabolic activities and their requirement for conditions of anaerobiosis, sulphidogenic bacteria are almost invariably found in nature as component organisms within microbial consortia . The capacity to generate significant quantities of sulphide influences the overall metabolic activity and species diversity of these consortia, and is the root cause of the environmental impact of the sulphidogenic species: corrosion, pollution and the souring of hydrocarbon reservoirs. Chem Biol, 1999 Feb, 6(2), R39 - 48 How do peptide synthetases generate structural diversity? Konz D, Marahiel MA. Many low-molecular-weight peptides of microbial origin are synthesized nonribosomally on large multifunctional proteins, termed peptide synthetases . These enzymes contain repeated building blocks in which several defined domains catalyze specific reactions of peptide synthesis . The order of these domains within the enzyme determines the sequence and structure of the peptide product. J Am Pharm Assoc (Wash), 1999 Jan-Feb, 39(1), 27 - 31 Comparison of melatonin products against USP's nutritional supplements standards and other criteria; Hahm H et al.; OBJECTIVE: To evaluate and compare the quality of a sample of melatonin products, as measured by the United States Pharmacopeial Convention (USP) General Tests and Assays for Nutritional Supplements (other than Microbial Limits) and certain other tests . DESIGN: Five immediate-release, two sublingual, and two controlled-release products were randomly gathered from a health food store, groceries, and pharmacies in the Baltimore-Washington metropolitan area . MAIN OUTCOME MEASURES: Weight variation, disintegration (not applicable for controlled-release products), and drug dissolution, based on USP standards . Twelve-hour dissolution profiles were obtained from the controlled-release products . All tablets were also evaluated for friability following the USP procedure and for hardness following unofficial procedures . RESULTS: All products passed the weight variation test . Two products showed excessive friability . Three immediate-release products failed both the disintegration and the dissolution tests . One of the three products demonstrated a threefold difference in hardness . One controlled-release product released 90% of melatonin in four hours in the dissolution test; the other released 90% of its content in 12 hours . CONCLUSION: Some products showed evidence of poor formulation and/or poor quality control as indicated by excessive friability, failure to disintegrate and dissolve, and excessive variation in hardness . In vitro release profiles of the two controlled-release products were substantially different . The poor quality of some supplements should be a concern to consumers and health care providers. J Exp Med, 1999 Feb 15, 189(4), 741 - 6 Macrophage microbicidal mechanisms in vivo: reactive nitrogen versus oxygen intermediates in the killing of intracellular visceral Leishmania donovani; Murray HW et al.; To determine the relative contributions of respiratory burst-derived reactive oxygen intermediates (ROI) versus reactive nitrogen intermediates (RNI) to macrophage-mediated intracellular host defense, mice genetically deficient in these mechanisms were challenged with Leishmania donovani, a protozoan that selectively parasitizes visceral tissue macrophages . During the early stage of liver infection at wk 2, both respiratory burst-deficient gp91(phox)-/- (X-linked chronic granulomatous disease {X-CGD}) mice and inducible nitric oxide synthase (iNOS) knockout (KO) mice displayed comparably increased susceptibility . Thereafter, infection was unrestrained in mice lacking iNOS but was fully controlled in X-CGD mice . Mononuclear cell influx into infected liver foci in X-CGD and iNOS KO mice was also overtly impaired at wk 2 . However, granuloma assembly in parasitized tissue eventually developed in both hosts but with divergent effects: mature granulomas were functionally active (leishmanicidal) in X-CGD mice but inert in iNOS-deficient animals . These results suggest that (a) ROI and RNI probably act together in the early stage of intracellular infection to regulate both tissue recruitment of mononuclear inflammatory cells and the initial extent of microbial replication, (b) RNI alone are necessary and sufficient for eventual control of visceral infection, and (c) although mature granulomas have traditionally been associated with control of such infections, these structures fail to limit intracellular parasite replication in the absence of iNOS. Med Mycol, 1998, 36 Suppl 1, 194 - 206 New approaches to antifungal chemotherapy; Viviani MA et al.; The antifungal agents currently available to treat invasive fungal infections are limited in both number and usefulness . Treatment with the polyene amphotericin B (AmB), and with several azoles, in particular fluconazole and itraconazole, is the mainstay of antifungal chemotherapy . However, the clinical usefulness of these drugs is hampered by drawbacks associated with their safety and/or efficacy . There are two approaches to overcome this situation . One is to discover and develop new antifungal agents or formulations with advantages over and/or complementary to existing drugs . For this purpose, the following three categories of new drugs have been the major targets of study and development: (i) lipid formulations of polyenes, (ii) azoles (including cyclodextrin-complexes), and (iii) nonazole compounds, particularly those of microbial origin (antibiotics). Mol Microbiol, 1999 Jan, 31(1), 223 - 35 Molecular characterization of a novel peroxidase isolated from the ligninolytic fungus Pleurotus eryngii; Ruiz-Duenas FJ et al.; A haem peroxidase different from other microbial, plant and animal peroxidases is described . The enzyme is secreted as two isoforms by dikaryotic Pleurotus eryngii in peptone-containing liquid medium . The corresponding gene, which presents 15 introns and encodes a 361-amino-acid protein with a 30-amino-acid signal peptide, was isolated as two alleles corresponding to the two isoforms . The alleles differ in three amino acid residues and in a seven nucleotide deletion affecting a single metal response element in the promoter . When compared with Phanerochaete chrysosporium peroxidases, the new enzyme appears closer to lignin peroxidase (LiP) than to Mn-dependent peroxidase (MnP) isoenzymes (58-60% and 55% identity respectively) . The molecular model built using crystal structures of three fungal peroxidases as templates, also showed high structural affinity with LiP (C alpha-distance 1.2 A) . However, this peroxidase includes a Mn2+ binding site formed by three acidic residues (E36, E40 and D175) near the haem internal propionate, which accounts for the ability to oxidize Mn2+ . Its capability to oxidize aromatic substrates could involve interactions with aromatic residues at the edge of the haem channel . Another possibility is long-range electron transfer, e.g . from W164, which occupies the same position of LiP W171 recently reported as involved in the catalytic cycle of LiP. Coll Antropol, 1998 Dec, 22 Suppl, 103 - 9 Reduction of epithelial dendritic cells in keratotic lesion of oral lichen planus; Mravak-Stipetic M et al.; The number and distribution of epithelial dendritic cells (EDC) in oral mucosal lesions are variable depending on the degree of epithelial maturation/differentiation and disease activity . Localized absence of EDC might impair mucosal immunologic protection, allow microbial colonization and enhance carcinogenesis . Increased number of EDC during the early stage of oral lichen planus (OLP) suggests their increased antigen-presenting capability and immunologic activity with inflammatory reaction, but their role in the process of keratinization remains unclear . Therefore, the purpose of this study was to determine the number and distribution of EDC in 33 biopsy specimens from lesions of OLP and from 18 control specimens of leukoplakia (LPL) at sites undergoing increased keratinization . Cells were identified immunocytochemically by the presence of antigen CD68 and labeled with acid phosphatase (AP) and alpha-naphthyl acetate esterase (ANAE) techniques . Numbers of EDC were expressed per mm epithelial surface length . Significantly more EDC with prominent histoenzymatic activity of AP and ANAE were present in OLP than in LPL . Intense enzymatic activity of ANAE was expressed in EDC of OLP with hyperparakeratosis . In the lesions with increased keratinization the number of EDC was markedly reduced in OLP while in LPL remained unchanged . Reduced number and subbasal redistribution of EDC in OLP suggest diminution of immunologic reaction and disease activity but also increased tissue vulnerability to various antigen challenges. Math Biosci, 1998 Dec 15, 154(2), 87 - 102 On the coexistence of three microbial populations competing for two complementary substrates in configurations of interconnected chemostats; Thomopoulos NA et al.; We examine the question of coexistence of three microbial populations competing for two complementary rate-limiting substrates in configurations of interconnected chemostats . It is known that coexistence of two populations competing for two rate-limiting substrates is possible in a single chemostat, but coexistence is not possible when three populations are involved . We examine whether coexistence of three populations becomes possible by considering configurations of two or three interconnected chemostats, thus allowing for effects of spatial heterogeneity . Computational analysis of the model equations indicates that in the case of two chemostats coexistence is possible only for specific discrete parameter values where the system is structurally unstable and therefore the coexistence state is not practically attainable, whereas in the case of three chemostats coexistence is possible for a whole range of parameter values where the system is structurally stable and therefore the coexistence state can be realized in practice. Zh Mikrobiol Epidemiol Immunobiol, 1998 Nov-Dec, (6), 23 - 5 {Effect of technogenic pollution on bacterial biocenoses of a water reservoir}; Boiko AV et al.; The industrial pollution of a water reservoir (the Volga), both indirect and direct, not exceeding the highest admissible level, has been shown to lead to the transformation of water microbial associations . The total amount of bacteria increases simultaneously with the decrease of their specific diversity, the ratio of the members of different microbiocenoses changes towards an increase in the proportion of bacteria, resistant to stress influences, which may lead to the growth of the epidemic danger of the polluted areas of the water reservoir. Adv Biochem Eng Biotechnol, 1999, 63, 109 - 23 Production of chiral C3- and C4-units by microbial enzymes; Shimizu S et al.; Enzyme (biocatalysis) reactions display far greater specificities, such as substrate specificity, stereospecificity, regiospecificity and so on, than more conventional forms of organic reactions . Using these specificities of the enzymes, many useful compounds have been enzymatically produced . Compounds possessing C3- and C4-units with additional functional groups are promising materials for the synthesis of various useful compounds . In particular, optically active C3- and C4-synthetic units are quite important intermediates for the preparation of pharmaceuticals and fine chemicals . Microbial transformation with enzymes showing stereo-specificities have been applied to the asymmetric synthesis of optically active substances . In this article the recent works on the practical production of chiral C3- and C4-synthetic units with microbial enzymes are described. Dtsch Tierarztl Wochenschr, 1998 Dec, 105(12), 472 - 4 Forestomach motility in llamas and camels; von Engelhardt W; Major aspects of forestomach anatomy in llamas and camels are described . The pattern of forestomach motility is a succession of motoric cycles, consisting of A- and B-contraction sequences and a pause . Respective differences between llamas and camels are discussed . Observations on regulation of motility are mentioned . Occurrences and courses of rumination and eructation within the motility cycles are emphasized . Motility of the forestomach achieves a selective retention of feed particles in the forestomach; a long retention time is a prerequisite for an effective microbial digestion, especially of poor quality feed. Cas Lek Cesk, 1998 Nov 16, 137(22), 694 - 9 {Treatment of febrile neutropenia in patients with solid tumors}; Novotny J et al.; BACKGROUND: Febrile neutropenia (FN) is one of the most serious complications of anti-tumourous treatment calling for early diagnosis and intensive treatment . The objective of the trial was to recommend a standard procedure for the treatment of febrile neutropenia at their Oncological Clinic, based on analyses of attacks of febrile neutropenia and the current microbial situation . METHODS AND RESULTS: In 1995-1997 in 30 patients (24 women, 6 men) 39 attacks of febrile neutropenia were treated . The age distribution of patients was within the range of 20-68 years, the mean age being 50 years . In the group patients with breast cancer predominated (14), soft tissue sarcomas (4), colorectal carcinoma (3), other diagnoses participated with 9 episodes . The analysis of the microbial situation was based on cultivation findings made in patients with attacks of FN . For empirical treatment of FN the authors use at combined treatment piperacillin-gentamicin or sultamicillin-cefpodoxim/or ciprofloxacin . If empirical treatment fails, therapy is based on the results of cultivation and the patient's clinical condition . Growth factors are indicated for treatment only in FN complicated by mycotic infection, inflammatory pulmonary infiltrates or cardiopulmonary failure . CONCLUSIONS: The standard procedure in the treatment of FN should be broad spectrum bactericidial antibiotics . The use of growth factors is reserved for complicated episodes of FN. J Pediatr Adolesc Gynecol, 1999 Feb, 12(1), 23 - 5 Combined oral and vaginal treatment of severe vulvovaginitis during childhood; Creatsas G et al.; STUDY OBJECTIVE: To evaluate the efficacy and safety of combined oral and vaginal administration of antibiotics . DESIGN: Treatment and follow-up examination of 54 cases of severe vulvovaginitis . SETTING: Division of Pediatric and Adolescent' Gynecology, Second Department of Obstetrics and Gynecology, University of Athens, Greece . PARTICIPANTS: Girls aged 1-10 years seen at the clinic of the above-listed institution . INTERVENTIONS: Vaginal application of antibiotics . MAIN OUTCOME MEASURES: Vaginal culture and vaginoscopy . RESULTS: Treatment achieved microbial eradication in 51 of 54 patients (94%) . In most patients, relief of symptoms was achieved after 2-3 days . No adverse effects were reported . CONCLUSIONS: Treatment was highly effective and simple to administer, and no complications were observed . A further advantage of this approach is the shorter duration of treatment. Clin Cardiol, 1999 Jan, 22(1 Suppl 1), I17 - 22 Intrapericardial treatment of inflammatory and neoplastic pericarditis guided by pericardioscopy and epicardial biopsy--results from a pilot study; Maisch B et al.; From a registry of 136 patients undergoing pericardiocentesis, 14 patients with autoimmune and 15 patients with neoplastic effusions were selected . All underwent pericardioscopy, epicardial and pericardial biopsy with histologic, immunohistologic, and polymerase chain reaction/or in situ hybridization analysis for microbial DNAs and RNA . Pericardioscopy identified neoplastic effusions by the high occurrence of protrusions . Fibrin threads and layers and neovascularization were found in both groups . For identification of the inflammatory and neoplastic process, the combined analysis of the cytology of the effusion and epicardial biopsy evaluation proved to be most important . Epicardial biopsy demonstrated a slightly higher sensitivity for identifying neoplastic disorders in the pericardium than cytology alone . Pericardial biopsy was inconclusive . Intrapericardial administration of 1 g of crystalloid triamcinolone in autoreactive pericarditis prevented recurrence in 13 of the 14 cases after 3 months and in 12 of the 14 cases after 1 year . In neoplastic effusion, intrapericardial administration of 50 mg cis-platin for 24 h prevented recurrence of a hemodynamically relevant effusion after 3 months in all, and after 6-12 months in 14 of 15 patients . Mortality in neoplastic effusion due to noncardiac tumor progression was 47 and 80%, respectively, after 3 and 6 months, as can be expected in endstage neoplastic disease . This pilot study demonstrates that local drug application is feasible, life-saving, and well tolerated by the patients . It opens perspectives for local drug application in other cardiac disorders as well. Microb Ecol, 1999 Feb, 37(2), 86 - 94 Growth Rates of Marine Bacterial Isolates on Particulate Organic Substrates Solubilized by Freely Released Extracellular Enzymes; Vetter YA et al.; > Abstract Growth rates of marine bacterial isolates on particulate organic substrates were measured using a novel apparatus which restricts bacterial cells to the uptake of hydrolysate produced from particulate substrates only by enzymes that are actively released from the bacterium into the culture medium . Significant, varying growth rates were measured for four different marine bacteria, using three different, ecologically significant particulate organic substrates (preparations of amylopectin, chitin, and animal hide) . Growth rates sometimes approached but were usually lower than rates that have been reported in laboratory experiments using dissolved organic growth substrates . These results are consistent with recent model predictions and have important implications for microbial ecology and material cycling in diverse liquid-bathed environments. Eur J Epidemiol, 1998 Dec, 14(8), 749 - 54 Cancer increased after a reduction of infections in the first half of this century in Italy: etiologic and preventive implications; Mastrangelo G et al.; Two rate ratios indicating the disappearance of infections and the growth of tumours, respectively, were simultaneously plotted against the calendar years of occurrence in a period during which mortality rates were reasonably comparable to incidences . The transformation used gave upward trend time variations for infectious diseases, providing strong evidence that in Italy during the first half of this century variations in infectious diseases preceded variations in cancer . While some bacteria and viruses are known to be cancer agents, sparse studies indicate that a host's immune response to infection may destroy cancer cells . With a decreasing mortality from infectious illnesses, there may have been a reduction in the activation of immunological mechanisms against transformed cells in early phases of carcinogenesis . If cancer growth is a consequence of a lower exposure to chronic sublethal doses of microbial agents, bacterial derivates could be potentially useful in cancer chemoprevention. Ann N Y Acad Sci, 1998 Dec 30, 862, 100 - 4 Xenozoonoses and the xenotransplant recipient; Michaels M; The use of animal cells, tissues, or organs for humans is being investigated as an alternative to allotransplantation and as therapy for a broad range of disease states including diabetes, Parkinson's disease, and neurologic pain control . The risk of transmitting novel infections with these tissues, xenozoonoses, has led to much debate . It is well recognized that infections are a hazard with the use of all biologic agents . In addition, infections from human donors remain a major cause of morbidity and mortality after allotransplantation . Accordingly the potential for animal microbial agents to be pathogenic in the human recipient after xenotransplantation and be transmissible to others must be critically examined . Along with laboratory-based research, clinical trials must be conducted in a manner to evaluate the transmission of potential animal infections . Pretransplant evaluation should include discussions with the candidate and, if possible, with close contacts . Information must be provided as to the potential risks of infection and transmission to others . Behavioral modifications which can decrease spread of infections should be emphasized . Serial samples should be obtained from the patients at defined intervals and if recipients become ill . In addition, archiving samples for future evaluation is critical . Prospective evaluation will enhance the ability to define and understand the spectrum of xenogeneic infections. Ann N Y Acad Sci, 1998 Dec 13, 864, 87 - 95 Chiral alcohol synthesis with microbial carbonyl reductases in a water-organic solvent two-phase system; Shimizu S et al.; Production of chiral 4-chloro-3-hydroxybutanoate ethyl esters (CHBE) was performed through microbial asymmetric reduction of 4-chloroacetoacetate ethyl ester (CAAE) . The enzymes reducing CAAE to (R)- and (S)-CHBE were found to be produced by Sporobolomyces salmonicolor and Candida magnoliae, respectively . The enzyme of S . salmonicolor is a novel NADPH-dependent aldehyde reductase (AR) belonging to the aldo-keto reductase superfamily . When AR-overproducing Escherichia coli transformant cells or C . magnoliae cells were incubated in an organic solvent-water two-phase system, 300 or 90 mg/mL of CAAE was almost stoichiometrically converted to (R)- or (S)-CHBE (> 92% ee), respectively. Cancer Res, 1999 Jan 15, 59(2), 482 - 6 Mannosylerythritol lipid is a potent inducer of apoptosis and differentiation of mouse melanoma cells in culture; Zhao X et al.; Malignant melanomas are tumors that are well known to respond poorly to treatment with chemotherapeutic reagents . We report here that mannosylerythritol lipid (MEL), an extracellular glycolipid from yeast, markedly inhibited the growth of mouse melanoma B16 cells in a dose-dependent manner . Exposure of B16 cells to MEL at 10 microM and higher concentrations caused the condensation of chromatin, DNA fragmentation, and sub-G1 arrest, all of which are hallmarks of cells that are undergoing apoptosis . Analysis of the cell cycle also suggested that both the MEL-mediated inhibition of growth and apoptosis were closely associated with growth arrest in the G1 phase . Moreover, MEL exposure stimulated the expression of differentiation markers of melanoma cells, such as tyrosinase activity and the enhanced production of melanin, which is an indication that MEL triggered both apoptotic and cell differentiation programs . Forced expression of Bcl-2 protein in stably transformed B16 cells had a dual effect: it interfered with MEL-induced apoptosis but increased both tyrosinase activity and the production of melanin as compared with these phenomena in vector-transfected MEL-treated control B16 cells . These results provide the first evidence that growth arrest, apoptosis, and the differentiation of mouse malignant melanoma cells can be induced by a microbial extracellular glycolipid. J Periodontol, 1998 Dec, 69(12), 1382 - 91 Periodontitis-associated marker bacteria in an urban North American patient population: application of a commercial immunoassay; Eggert FM et al.; We used an immunoassay to demonstrate marker organisms (Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans) in 3 private practice populations (F-ME periodontist, 55 patients; MHM periodontist, 179 patients; and EWM general dentist, 19 patients) . Occurrence of the marker organisms involves the whole oral environment, not just individual sites, as shown by close correlation between presence of the marker organisms in 2 independent sites/samples within a single mouth . Presence of the marker P . gingivalis (and P . intermedia) relates closely to periodontal pocketing while presence of A . actinomycetemcomitans does not have this pocket-associated characteristic . There was no significant relationship between presence of the marker organisms and the number of teeth in a mouth, and in the periodontal practice patients there was no significant effect of gender on occurrence of the marker organisms . A . actinomycetemcomitans and the other 2 markers were found over the entire age range (12 to 75) of our patients . Regular periodontal treatment reduced occurrence of all marker organisms and increased the frequency of marker-negative patients and sites . Occurrence of the marker organisms above immunoassay threshold levels appears to represent how receptive a patient is to each individual organism . Most patients appear receptive to the presence of P . intermedia whether treated or not . Significantly fewer patients who underwent regular treatment show the presence of P . gingivalis or A . actinomycetemcomitans when compared to untreated patients . Diagnostic application of microbial markers requires ongoing clinical assessment of patients and careful clinical judgment . 1391. Appl Environ Microbiol, 1999 Feb, 65(2), 795 - 801 Changes in bacterial and eukaryotic community structure after mass lysis of filamentous cyanobacteria associated with viruses; van Hannen EJ et al.; During an experiment in two laboratory-scale enclosures filled with lake water (130 liters each) we noticed the almost-complete lysis of the cyanobacterial population . Based on electron microscopic observations of viral particles inside cyanobacterial filaments and counts of virus-like particles, we concluded that a viral lysis of the filamentous cyanobacteria had taken place . Denaturing gradient gel electrophoresis (DGGE) of 16S ribosomal DNA fragments qualitatively monitored the removal of the cyanobacterial species from the community and the appearance of newly emerging bacterial species . The majority of these bacteria were related to the Cytophagales and actinomycetes, bacterial divisions known to contain species capable of degrading complex organic molecules . A few days after the cyanobacteria started to lyse, a rotifer species became dominant in the DGGE profile of the eukaryotic community . Since rotifers play an important role in the carbon transfer between the microbial loop and higher trophic levels, these observations confirm the role of viruses in channeling carbon through food webs . Multidimensional scaling analysis of the DGGE profiles showed large changes in the structures of both the bacterial and eukaryotic communities at the time of lysis . These changes were remarkably similar in the two enclosures, indicating that such community structure changes are not random but occur according to a fixed pattern . Our findings strongly support the idea that viruses can structure microbial communities. Appl Environ Microbiol, 1999 Feb, 65(2), 718 - 23 Diversity of arbuscular mycorrhizal fungus populations in heavy-metal-contaminated soils; Del Val C et al.; High concentrations of heavy metals have been shown to adversely affect the size, diversity, and activity of microbial populations in soil . The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long-term experiment . Due to the reduced number of indigenous AM fungal (AMF) propagules in the experimental soils, several host plants with different life cycles were used to multiply indigenous fungi . Six AMF ecotypes were found in the experimental soils, showing consistent differences with regard to their tolerance to the presence of heavy metals . AMF ecotypes ranged from very sensitive to the presence of metals to relatively tolerant to high rates of heavy metals in soil . Total AMF spore numbers decreased with increasing amounts of heavy metals in the soil . However, species richness and diversity as measured by the Shannon-Wiener index increased in soils receiving intermediate rates of sludge contamination but decreased in soils receiving the highest rate of heavy-metal-contaminated sludge . Relative densities of most AMF species were also significantly influenced by soil treatments . Host plant species exerted a selective influence on AMF population size and diversity . We conclude based on the results of this study that size and diversity of AMF populations were modified in metal-polluted soils, even in those with metal concentrations that were below the upper limits accepted by the European Union for agricultural soils. Br Poult Sci, 1998 Dec, 39(5), 612 - 21 Strategies to improve the nutritive value of rice bran in poultry diets . IV . Effects of addition of fish meal and a microbial phytase to duckling diets on bird performance and amino acid digestibility; Martin EA et al.; 1 . Ducklings were given diets with vegetable protein (VP) and 0 or 600 g rice bran/kg; fish meal (60 g/kg) and a phytase (+, -) were added to the diets (VP + AP) . An additional 40 g soyabean meal/kg was added to the diet with rice bran (VP ++) . Amino acid digestibility and mineral retention were measured in the lower ileum of ducklings killed at 23 d of age . Acid insoluble ash was used as an inert marker . Trypsin and amylase activities were also measured and weights of the pancreas and small intestine recorded at slaughter . 2 . Addition of soyabean meal (VP ++) to the diet with rice bran improved growth rate and food intake compared to the diet without (VP) and gave the same food intake and growth rate as the comparable basal diet (VP) without rice bran . Fish meal improved growth rate on the diets without rice bran and improved food intake on this diet (VP + AP) . Rice bran depressed growth rate and food conversion ratio (FCR); protein source affected growth rate, food intake and FCR; phytase increased food intake only . There were several interactions . 3 . Determined total amino acid composition of the diets appeared to meet the essential amino acid requirements of ducklings . Rice bran depressed the ileal digestibility of virtually all amino acids and phytase had no direct effect, although there were interactions . Fish meal addition to diets with rice bran improved the apparent digestibility of several essential amino acids as well as that of dry matter and crude protein . 4 . Ileal retention of some minerals and tibia ash content were reduced by rice bran . Fish meal and phytase inclusion increased P retention and ash in tibia . 5 . Higher intestinal trypsin activity and increased pancreas size were seen in ducklings on diets with rice bran compared to those without . Intestinal amylase activity was reduced in ducklings given rice bran, probably because of its low starch content . 6 . The stimulating effect of fish meal on duckling performance was probably caused in part by the improvement in the digestibility of some amino acids . The addition of small amounts of minerals in fish meal may have increased mineral retention . Phytase gave benefits anticipated from our previous work, but also improved lysine and threonine digestibility in diets containing vegetable protein only. Cancer Biochem Biophys, 1998 Nov, 16(4), 375 - 85 The instability of polyhydroxylated aromatic protein tyrosine kinase inhibitors in the presence of manganese; Ramdas L et al.; Inhibition of the tyrosine kinase activity of Src by forty-three different compounds from five chemical families (cinnamic acid, salicylic acid, phenol, coumarin and flavonoid derivatives) representing plant and microbial secondary metabolites were studied in the presence of MgCl2 versus MnCl2 . Within each chemical family, compounds containing multiple hydroxyl substituents demonstrated the greatest inhibitor potency . The ortho-substituted dihydroxy compounds were the most inhibitory . Except for the flavonoids, inhibition was higher in the presence of manganese compared to that observed with magnesium . UV-Vis spectra, HPLC, and mass spectrometric analyses demonstrate that manganese catalyzed the oxidation of these compounds . The general instability of such compounds, especially in the presence of manganese, and the associated problems it causes in the use of such compounds for developing selective protein tyrosine kinase inhibitors, is discussed. Br J Ophthalmol, 1998 Nov, 82(11), 1272 - 5 Disposable contact lens use as a risk factor for microbial keratitis; Radford CF et al.; AIMS: A case-control study was performed to evaluate soft contact lens (SCL) wear modality as a risk factor for microbial keratitis . METHODS: Contact lens wearers presenting as new patients to Moorfields Eye Hospital accident and emergency department during a 12 month period completed a self administered questionnaire detailing demographic data and contact lens use habits . Cases were patients with a clinical diagnosis of SCL related microbial keratitis . Controls were SCL users attending with disorders unrelated to contact lens wear . Odds ratios (estimates of relative risks) and 95% confidence limits (CL) were calculated through multivariable logistic regression analysis . RESULTS: There were 89 cases and 566 controls . A substantially increased risk with 1-4 weekly disposable SCL compared with non-disposable SCL was identified among both daily wear (DW) (odds ratio = 3.51, 95% CL 1.60-7.66, p = 0.002) and extended wear (odds ratio 4.76, 95% CL 1.52-14.87, p = 0.007) users after adjustment for demographic, lens use and hygiene variables . Other significant factors among DW users were "occasional" overnight use, use of chlorine based (as opposed to other chemical) systems in combination with poor storage case hygiene, and irregular disinfection . CONCLUSION: Properties of some disposable SCL may be partly responsible for these excess risks . It is also possible, however, that this finding is largely a reflection of widespread complacency among patients and practitioners with respect to disposable SCL fitting and use. Br J Nutr, 1998 Oct, 80(4), 371 - 9 Transfers of N metabolites across the ovine liver in response to short-term infusions of an amino acid mixture into the mesenteric vein; Lobley GE et al.; The effect of acute (4.5 h) infusions into the mesenteric vein of an amino acid (AA) mixture, which simulated the composition of rumen microbial protein, on net transfers of NH3, urea and total AA across the portal-drained viscera (PDV) and liver in the ovine has been examined . Four wether sheep were surgically prepared with vascular catheters across the PDV and liver (Lobley et al . 1995) and were offered a basal diet of 1000 g grass pellets/d (approximately 1.4 x energy maintenance) . Each animal was infused at weekly intervals with one of four dilutions of the AA mixture . These dilutions provided 0.44, 0.88, 1.32 and 1.84 mmol AA-N/min infused, the lowest of which approximately doubled the net absorption of AA-N from the basal diet . Animals were treated with heparin to allow continuous collection of blood by peristaltic pump for 2 h preceding, and between 0.5-2.5 and 2.5-4.5 h after, the start of the AA infusions . Blood flow in the hepatic artery increased (100 v . 208 g/min; P = 0.002) in response to AA infusion, while hepatic portal venous flow decreased (2090 v . 1854 g/min; P = 0.006) . The AA infusion also stimulated O2 uptake by the PDV (P < 0.001) and liver (P = 0.016) . Absorption across the PDV and hepatic removal of NH3 were unchanged between basal and amino acid infusion conditions . Urea-N removal across the PDV was unaltered, but hepatic production increased (P < 0.001) with level of AA infusion . During infusions, net appearance of AA across the PDV was below the theoretical level . This may have been due to inhibition of AA uptake from the small intestine, and/or increased removal by the digestive tract of AA from the systemic circulation associated with greater arterial concentrations . Hepatic extraction of AA increased with level of infusion, both for total AA and those included in the infusate . Total hepatic urea-N production tended towards a maximum (estimated as 2 mumol N/g liver wet weight per min) . The AA removed by the liver and not used for ureagenesis remained similar (170 mumol AA-N/min) between basal and AA infusions . This was presumed available for anabolic purposes (mainly synthesis of export proteins) . The proportion of net AA-N appearance (absorption plus infused) across the PDV removed by the liver declined from 0.71 to 0.53 between basal and AA infusions . In contrast to findings from cattle (Wray-Cahen et al . 1997), increased AA infusion did not alter the net removal of glutamine across the liver . This may reflect differences between the studies in NH3: AA-N absorbed . Further differences between the cattle study and the current findings may relate to the different physiological state (pregnancy v . growth), which may alter the partition of AA between anabolic and catabolic fates. Science, 1999 Jan 29, 283(5402), 686 - 9 Acetogenesis from H2 plus CO2 by spirochetes from termite guts; Leadbetter JR et al.; Pure cultures of termite gut spirochetes were obtained and were shown to catalyze the synthesis of acetate from H2 plus CO2 . The 16S ribosomal DNA sequences of two strains were 98 percent similar and were affiliated with those of the genus Treponema . However, neither was closely related to any known treponeme . These findings imply an important role for spirochetes in termite nutrition, help to reconcile the dominance of acetogenesis over methanogenesis as an H2 sink in termite hindguts, suggest that the motility of termite gut protozoa by means of attached spirochetes may be based on interspecies H2 transfer, and underscore the importance of termites as a rich reservoir of novel microbial diversity. J Public Health Med, 1998 Dec, 20(4), 386 - 95 Impact of infection on mortality and hospitalization in the North East of England; Wilson D et al.; BACKGROUND: Current modes of presentation of mortality and hospitalization data, based on codes in Chapter 1 of the International Classification of Diseases (ICD), hide the true importance of infection and other microbial diseases (infections) . Our aim was to produce a new aggregation of ICD-9 to estimate their true impact . METHODS: ICD-9 codes for infections, irrespective of ICD-9 chapter, were extracted to form the new aggregation . We reanalysed routine mortality (1979-1983 and 1989-1993) and hospital finished consultant episode data (FCEs) (1989-1993) in the area of the former Northern Regional Health Authority (population approximately 3 million) using the new aggregation of codes . This area is in the North East of England . Age- and sex-specific rates of death and FCE from infection were calculated using mid-1981 and mid-1991 population estimates . RESULTS: Using ICD-9 Chapter 1 codes, 839 (0.4 per cent) deaths in 1989-1993 were classified as due to infection, compared with 12655 (6.7 per cent) with the new aggregation . In 1979-1983, 10.3 per cent of all deaths were due to infection . The highest rates of infection death were in the oldest age groups and infants . FCEs for infections were 1.2 per cent using ICD-9 Chapter 1 codes, but 5.4 per cent using the new aggregation . The highest rates of infection FCEs were in infants . Most infection deaths and hospitalizations were for respiratory disorders . Using the new aggregation, infection moved from the 13th ranking cause of death to the third ranking cause; and from the 15th ranking cause of hospitalization to the 10th . CONCLUSIONS: The usual method of presenting data coded by ICD-9 chapters greatly understates the contribution of infection to morbidity and mortality and may mislead policy makers assessing the priority to be given to infections. Int J Prosthodont, 1998 Sep-Oct, 11(5), 433 - 41 Microbial colonization of the peri-implant environment and its relevance to long-term success of osseointegrated implants; Ellen RP; PURPOSE: This article provides a critical examination of the literature on the colonization of the peri-implant environment and its impact on clinically significant infection, in the context of a comparison with the microbial etiology of periodontitis . MATERIALS AND METHODS: Previous journal article bibliographies and MEDLINE searches provided comprehensive access to current literature on this topic . References that provided significant or novel advancements in knowledge were included in this review . Since it was prepared for a workshop that would examine this issue critically, this review offers provocative commentary . RESULTS: There are many similarities in peri-implant and periodontal microbiology, both in health and in infection leading to progressive deterioration . Periodontal pockets serve as reservoirs for the colonization of implants by periodontal pathogens in partially edentulous patients . Implant design and material composition affect the colonization of implant surfaces . Infections around implants can be treated by similar strategies used for periodontitis . Investigators are beginning to adopt research designs used in periodontology to study the pathogenesis and treatment of peri-implant infections . Research in this area is impeded by the lack of surrogate variables for crestal bone resorption . CONCLUSION: Some implants fail as a result of infection, but the frequency of failure by infection or any other cause is unknown . This paper suggests areas where much more additional research is needed, including critical consideration of strategies that have led to the past few decades' advancements in the pathogenesis of periodontitis. Am J Respir Cell Mol Biol, 1999 Feb, 20(2), 219 - 27 Brief exposure to 95% oxygen alters surfactant protein D and mRNA in adult rat alveolar and bronchiolar epithelium; Aderibigbe AO et al.; Surfactant protein D (SP-D), which has structural homology to C-type lectin binding regions, may play a role in host defense and has no known surfactant function . Because other surfactant proteins have been shown to be increased after prolonged periods of hyperoxia, we sought to evaluate the early effects of hyperoxia (95% O2) on expression of SP-D in the adult male rat lung . Animals were exposed to air or to 12, 36, or 60 h of 95% O2 . Northern blot analysis of total lung RNA revealed marked SP-D mRNA increases at 12 h 95% O2 compared with air-exposed controls, with decreasing expression to near that of air-exposed animals by 60 h . Semiquantitative in situ RNA hybridization demonstrated parallel results, with increased numbers of labeled alveolar epithelial (AE) and bronchiolar epithelial (BE) cells at 12 h and increased intensity of labeled alveolar cells, compared with air-exposed controls . After 60 h of exposure to 95% O2, mRNA label intensity in AE and BE was decreased to levels near those seen in air-exposed animals . In contrast, Western blotting showed a decline in total lung SP-D with 95% O2 exposure, beginning at 12 h and continuing at 36 and 60 h, respectively . Semiquantitative immunohistochemistry demonstrated a decline in AE labeling parallel to the total lung Western blot results, but labeled total BE cell numbers increased (P = 0.10) . Hyperoxia had differential effects on SP-D abundance in AE and BE cells, and therefore may influence the availability of SP-D to bind microbial pathogens in the airways depending on cell type and location. J Food Prot, 1999 Jan, 62(1), 10 - 5 Influence of various commercial packaging conditions on survival of Escherichia coli O157:H7 to irradiation by electron beam versus gamma rays; Lopez-Gonzalez V et al.; Irradiation of ground beef patties inoculated with the organism Escherichia coli O157:H7 was performed either by gamma rays from a cobalt 60 source or by electron beam generated by a linear accelerator . Patties were packaged in one of the following materials: nylon/polyethylene bags, Saran/polyester/polyethylene bags (PM2), or Saran overwrap with a Styrofoam tray inside . Bags were sealed in air or under vacuum and were irradiated at either 5 or -15 degrees C . Average D10 values (dose required to inactivate 90% of a microbial population) ranged from 0.27 to 0.63 kGy, depending on the conditions . Overall, higher D10 values (P<0.0001) were obtained upon irradiation at -15 degrees C as compared with 5 degrees C . Cells inoculated in samples packaged in PM2 had the highest D10 values, but only if irradiated by electron beam at -15 degrees C (P<0.001) . Since PM2 had the lowest oxygen permeability rate and since the temperature was too low for radicals to migrate easily, these conditions may have minimized the effect of oxygen- and water-derived radicals on microbial survival . Irradiation by gamma rays resulted in higher D10 values (P<0.047) than irradiation by electron beam, with the highest values being observed at -15 degrees C . Differences may be attributed to dose rate (1.0 kGy/h for gamma, 17 kGy/min for electron beam) since it is possible that, at low dose rates, microbial enzymes may have more time to repair damage to the cell due to irradiation, resulting in higher D10 values. J Parasitol, 1998 Dec, 84(6), 1274 - 7 Beneficial effect of selenium supplementation during murine infection with Trypanosoma cruzi; Davis CD et al.; Selenium (Se) has been shown to function as an antioxidant that may enhance immunity during microbial infection . To investigate the effect of elevated levels of Se on the course of experimental Chagas' disease, 5 groups of C3HeB/FeJ mice were infected with 10(3) bloodform trypomastigotes of a Brazil strain of Trypanosoma cruzi while receiving supplements of 0 ppm, 2 ppm, 4 ppm, 8 ppm, or 16 ppm Se as sodium selenate in drinking water . After 64 days of infection, survival ranged from 0 to 60%, with groups receiving 4 ppm and 8 ppm Se exhibiting 60% survival and the group without Se exhibiting 0% survival . In addition, parasitemia levels of mice supplemented with Se were significantly lower (P<0.01) than in nonsupplemented mice . The results of the present study suggest that Se supplementation does have a beneficial effect during murine infection with T . cruzi, resulting in decreased parasitemias and increased longevity. Cell Immunol, 1999 Jan 10, 191(1), 49 - 59 An inhibitor of CD28-CD80 interactions impairs CD28-mediated costimulation of human CD4 T cells; Fine JS et al.; We have identified and characterized a microbial extract-derived inhibitor of T cell CD28-dependent costimulation, NP1835-2, utilizing an in vitro system in which anti-human CD3 antibody and a human CD80-Ig fusion protein are immobilized on protein A-coated microspheres . This system is CD28-CD80-dependent, as judged by the specific ability of anti-CD80 antibody or cytotoxic T lymphocyte antigen-4-Ig to block human CD4 T cell responses . Activation of CD4 T cells in this system in presence of NP1835-2 resulted in a concentration-dependent inhibition of T cell proliferation (IC50 of 1-4 microg/ml), surface activation marker expression, and the production of many T cell cytokines, with the exception of TGFbeta . Impairment of T cell activation correlated with a blockade of cell cycle progression at G0/G1 and was only partly restored by addition of 100 U/ml IL-2 . No inhibition by NP1835-2 of T cell proliferation stimulated by plate-bound anti-CD3 antibody, phorbol 12-myristate 13-acetate + A23187, or P815 cells expressing the costimulatory molecule CD58 was observed . NP1835-2 was unable to modulate anti-IgM-stimulated B cell proliferation or LPS-induced monocyte activation . Suboptimal concentrations of NP1835-2 and cyclosporin together were able to impair T cell activation in an additive fashion . NP1835-2 was also able to inhibit the primary human MLR . These data indicate that NP1835-2 may belong to a class of molecules capable of selectively impairing CD28-mediated T cell costimulation and suggest its potential usefulness in the treatment of a variety of T cell-dependent diseases . Moreover, NP1835-2 may serve as a useful probe for investigating the mechanisms involved in T cell nonresponsiveness . Cell Immunol, 1999 Jan 10, 191(1), 20 - 5 Tetanus toxin impairs accessory and secretory functions in interferon-gamma-treated murine macrophages; Pitzurra L et al.; Tetanus neurotoxin (TT), a product of microbial origin, acts as a zinc endopeptidase on vesicle-associated membrane proteins (VAMP) . We have demonstrated that TT displays inhibitory effects on secretory and accessory functions in the murine macrophage (Mphi) cell line GG2EE . Nitric oxide (NO) secretion was decreased when interferon (IFN)-gamma-pretreated GG2EE Mphis were coincubated with a fungal costimulus (SMP200) and TT . When heat-inactivated TT was used this effect was not evident . The TT-mediated phenomenon was dose-dependent and specific since, under the same experimental conditions, it did not affect interleukin-6 or tumor necrosis factor-alpha secretion . Furthermore, IFN-gamma-induced major histocompatibility complex class II molecule expression and GG2EE accessory function, assessed by SMP200-stimulated lymphoproliferation, were also inhibited by TT . Such inhibition was incomplete, in line with our previous results showing that TT partially cleaves VAMP proteins in murine Mφ . Mycoses, 1998 Nov, 41(9-10), 383 - 8 Airborne fungi and their secondary metabolites in working places in a compost facility; Fischer G et al.; The present study investigates in detail the exposure to airborne fungal spores in working places in compost facilities . The fungal species composition in the air is compared with the spectrum of microbial metabolites with regard to the physiological properties of different fungal species . The results indicate that the spectrum of microbial volatile organic compounds (MVOCs) and the production of mycotoxins can be specific for certain species . In addition to the pathogenic and allergological relevance, the fungi may have different toxicological health impacts. Infect Immun, 1999 Feb, 67(2), 946 - 53 Human intestinal M cells display the sialyl Lewis A antigen; Giannasca PJ et al.; The biochemical features that distinguish human M cells from other intestinal epithelial cell types are important for understanding microbial pathogenesis and for targeting vaccines to the mucosal immune system . We applied a large panel of carbohydrate-specific monoclonal antibodies and lectins to Peyer's patch and cecum biopsy specimens from three normal individuals and a patient with inflammatory bowel disease . The results show that human M-cell glycosylation patterns are distinct from those of other species examined and that human M cells preferentially display the sialyl Lewis A antigen . This carbohydrate epitope is also present in a small subpopulation of enterocytes in the follicle-associated epithelium and in goblet cell mucins. Infect Immun, 1999 Feb, 67(2), 504 - 12 Genetic and physiologic characterization of urease of Actinomyces naeslundii; Morou-Bermudez E et al.; Ammonia production from urea by ureolytic oral bacteria is believed to have a significant impact on oral health and the ecological balance of oral microbial populations . In this study we cloned and characterized the urease gene cluster of Actinomyces naeslundii, which is one of the pioneer organisms in the oral cavity and a significant constituent of supragingival and subgingival dental plaque in children and adults . An internal fragment of the ureC gene of A . naeslundii WVU45 was initially amplified by PCR with degenerate primers derived from conserved amino acid sequences of the large catalytic subunit of urease in bacteria and plants . The PCR product was then used as a probe to identify recombinant bacteriophages carrying the A . naeslundii urease gene cluster and roughly 30 kbp of flanking DNA . Nucleotide sequence analysis demonstrated that the gene cluster was comprised of seven contiguously arranged open reading frames with significant homologies at the protein and nucleotide sequence levels to the ureABCEFGD genes from other organisms . By using primer extension, a putative transcription initiation site was mapped at 66 bases 5' to the start codon of ureA . A urease-deficient strain was constructed by insertion of a kanamycin resistance determinant within the ureC gene via allelic replacement . In contrast to the wild-type organism, the isogenic mutant was unable to grow in a semidefined medium supplemented with urea as the nitrogen source and was not protected by the addition of urea against killing in moderately acidic environments . These data indicated that urea can be effectively utilized as a nitrogen source by A . naeslundii via a urease-dependent pathway and that ureolysis can protect A . naeslundii against environmental acidification at physiologically relevant pH values . Therefore, urease could confer to A . naeslundii critical selective advantages over nonureolytic organisms in dental plaque, constituting an important determinant of plaque ecology. Curr Opin Rheumatol, 1999 Jan, 11(1), 11 - 6 Molecular approaches for identification of infectious agents in Wegener's granulomatosis and other vasculitides; Nikkari S et al.; The primary symptoms of many vasculitides resemble those of infectious diseases . Patients with Wegener's granulomatosis usually seek medical care for respiratory tract symptoms resembling those caused by infection or allergy . In addition, vasculitis is a well-documented manifestation of infection by some known microbial agents . There have been relatively few controlled studies, however, seeking to identify infectious agents as the triggering factors in systemic vasculitides . Molecular methods offer powerful approaches for the identification of infectious agents in diseases of previously unknown origin . These methods include broad-range amplification of microbial nucleic acid sequences and comparative or subtractive methods, such as differential display and representational difference analysis . Host gene expression profiles (using DNA-chip technology) may also provide clues as to the possible infectious cause of an idiopathic disease . Furthermore, the application of molecular methods may reveal pathologic mechanisms and novel therapeutic strategies for the vasculitides. Biotechniques, 1999 Jan, 26(1), 134 - 8, 140-1 General method for plasmid construction using homologous recombination; Raymond CK et al.; We describe a general method for plasmid assembly that uses yeast and extends beyond yeast-specific research applications . This technology exploits the homologous recombination, double-stranded break repair pathway in Saccharomyces cerevisiae to join DNA fragments . Synthetic, double-stranded "recombination linkers" were used to "subclone" a DNA fragment into a plasmid with > 80% efficiency . Quantitative data on the influence of DNA concentration and overlap length on the efficiency of recombination are presented . Using a simple procedure, plasmids were shuttled from yeast into E . coli for subsequent screening and large-scale plasmid preps . This simple method for plasmid construction has several advantages . (i) It bypasses the need for extensive PCR amplification and for purification, modification and/or ligation techniques routinely used for plasmid constructions . (ii) The method does not rely on available restriction sites, thus fragment and vector DNA can be joined within any DNA sequence . This enables the use of multifunctional cloning vectors for protein expression in mammalian cells, other yeast species, E . coli and other expression systems as discussed . (iii) Finally, the technology exploits yeast strains, plasmids and microbial techniques that are inexpensive and readily available. J Eur Acad Dermatol Venereol, 1998 Sep, 11 Suppl 1, S8 - 12; discussion S28-9 Topical therapy in acne; Gollnick H et al.; The majority of acne patients will receive a topical treatment either as monotherapy or in combination with a systemic drug therapy depending on the severity of the disease . The currently available topical agents affect at least one of the four main pathogenetic factors responsible for the development of acne, i.e . hyperkeratosis, microbial colonization, immune response and inflammation . Retinoids, azelaic acid, benzoyl peroxide and topical antibiotics represent the spectrum of the established and proven topical agents . Presumably, antiandrogenic agents will soon be available for topical use to treat the important factor of seborrhea . In general, by combining topical agents, their potency can be enhanced and toxicity diminished . Unfortunately, bacterial resistances are beginning to emerge as a significant problem. Rheum Dis Clin North Am, 1998 Nov, 24(4), 753 - 70 Features of spondyloarthritis around the world; Lau CS et al.; This article elucidates the prevalence and pathogenic roles of the MHC and microbial infections and clinical features and treatment of SpA across different populations from the arctic and subarctic regions to Central America, Asia, and Africa . Preliminary evidence suggests significant genetic and environmental influences on the onset and presentation of SpA, particularly AS, in these populations, which are different than those reported in white Caucasians; however, community surveys and longitudinal and case control studies are difficult to undertake in many of the developing countries . Thus, most of the currently available data have been devised from short-term and retrospective studies and should be treated with caution . Differences in referral and follow-up practices and the availability of rheumatology expertise and relevant resources may explain some of the differences observed in the populations discussed in this article . Furthermore, widely accepted criteria for the classification of SpA may not be applicable to non-Caucasians and need to be evaluated in these subjects . With gradual improvement in the economic status in many of the developing countries in Asia and Africa, it is hoped that with improvement in medical services, more physicians and specialty clinics in rheumatology, and changing referral patterns, better documentation of the various aspects of different SpA can be achieved . Future research should focus on the evaluation of specific risk or protective factors in population groups to better delineate the relative importance of genetic and environmental effects in the pathogenesis of SpA. J Dairy Sci, 1998 Dec, 81(12), 3350 - 69 Modeling ruminal digestibility of carbohydrates and microbial protein flow to the duodenum; Firkins JL et al.; Carbohydrates are the major source of energy for dairy cows and for microbial protein synthesis in the rumen . The prediction of ruminal carbohydrate digestibility and of the flow of microbial protein to the small intestine is difficult because of the variability among various feeds in the kinetics of digestion and passage of neutral detergent fiber and starch . Disappearance of fiber and starch in vitro or in situ and gas production in vitro have been extensively evaluated, improved, and reviewed . Similarly, markers and models to measure ruminal passage rate have been extensively researched and improved . Sources of variation and decreased accuracy for these techniques are discussed . Variation and potential errors also remain for the prediction of microbial protein flow to the duodenum using in vivo procedures . However, when in vivo results were accumulated into a database, microbial N flow to the duodenum over a wide range of conditions could be predicted accurately by intake of net energy for lactation or by dry matter intake and percentage of neutral detergent fiber in the diet . Although evaluation of feeding interactions and specific dietary limitations for microbial protein production in the rumen are possible with some models but not with this regression approach, mechanistic models need further validation and more accurate rate constants for improved accuracy over a wide range of conditions. J Dairy Sci, 1998 Dec, 81(12), 3248 - 58 Glucose metabolism and milk yield of cows infused abomasally or ruminally with starch; Knowlton KF et al.; The effect of ruminal or abomasal starch infusion on milk yield and glucose metabolism of early lactation cows was measured . Four cows were continuously infused in the rumen or abomasum with partially hydrolyzed starch (1500 g/d) or were not infused (control) for three 14-d periods during wk 4 to 12 postpartum . Milk yield averaged over 40 kg/d throughout the experiment . Milk and milk lactose yields tended to increase when starch was infused and DMI was decreased, regardless of the site of infusion . Starch infusion increased mean insulin concentration and tended to decrease the concentration of serum nonesterified fatty acids . Ruminal starch infusion did not affect glucose irreversible loss rate but tended to increase glucagon concentration and decrease glucose oxidation . The increased milk yield that occurred when starch was infused ruminally relative to the milk yield of control cows could be a result of increased microbial protein supply or increased energy availability . Compared with ruminal starch infusion, abomasal starch infusion tended to increase the irreversible loss rate of glucose and to increase glucose oxidation . Abomasal infusion tended to increase plasma insulin concentration and to decrease the nonesterified fatty acid concentration relative to ruminal infusion . Infusion of starch abomasally resulted in increases of most uses of glucose, including milk lactose production, glucose oxidation, and the possible storage of glucose as body fat, which indicates that the early lactation dairy cow has a greater capacity for glucose metabolism than is provided by voluntary feed intake of average diets, but that not all available glucose is partitioned to the mammary gland . These data should be useful in testing current concepts and equations in nutritional and metabolic models of dairy cattle. J Dairy Sci, 1998 Dec, 81(12), 3214 - 21 Effect of a Saccharomyces cerevisiae culture on nutrient digestion in lactating dairy cows; Doreau M et al.; The digestive effects of a Saccharomyces cerevisiae culture were investigated . Four cows in early lactation that were fitted with ruminal and duodenal cannulas were used in a crossover design . The diet, which consisted of 60% corn silage and 40% concentrates, was supplemented or not supplemented with a daily dose of 50 g of premix containing 0.5 g of S . cerevisiae (6 x 10(8) cfu/g of premix) . Total and ruminal digestibilities of organic matter, duodenal flows of nonmicrobial and microbial N, solid and liquid turnover rates, ruminal protozoal numbers, pH, ammonia N and volatile fatty acid concentrations, and concentrations of some plasma metabolites were not modified by the addition of S . cerevisiae . Ruminal dry matter content increased when S . cerevisiae was supplemented to the diet . In situ ruminal degradabilities of dry matter and neutral detergent fiber from corn stalk and of N from soybean meal were not modified; degradability of acid detergent fiber from corn stalk increased (32.5% vs . 26.3%) with the addition of S . cerevisiae . A short-term increase in N degradation was observed after 4 and 8 h of incubation . This experiment showed no effect of S . cerevisiae on most quantitative digestive events; however, a positive transitory postprandial effect on some parameters of microbial activity was observed. J Dairy Sci, 1998 Dec, 81(12), 3182 - 213 Effects of rumen-undegradable protein on dairy cow performance: a 12-year literature review; Santos FA et al.; In order to integrate and analyze knowledge on the use of protein supplements and protein nutrition of lactating dairy cows, we compiled a review of 108 studies published throughout the world, but principally in the Journal of Dairy Science between 1985 and 1997 . In 29 comparisons from 15 metabolism trials, soybean meal was replaced by high amounts of rumen undegradable protein (RUP) as a supplement; the benefits were not consistently observed for flow to the duodenum, essential amino acids, or lysine and methionine . High RUP diets resulted in decreased microbial protein synthesis in 76% of the comparisons . However, fish meal provided a good balance of lysine and methionine when calculated as a percentage of total essential amino acids . In 127 comparisons from 88 lactation trials that were published from 1985 to 1997, researchers studied the effects of replacing soybean meal with high RUP sources, such as heated and chemically treated soybean meal, corn gluten meal, distillers grains, brewers grains, blood meal, meat and bone meal, feather meal, or blends of these sources; milk yield was significantly higher in only 17% of the comparisons . Fish meal and treated soybean meal accounted for most of the positive effects on milk yield from RUP; corn gluten meal resulted in mostly negative results . The percentage of fat in milk was depressed more by fish meal than by other RUP sources . Protein percentage was decreased in 28 comparisons and increased in only 6 comparisons, probably reflecting the decrease in microbial protein synthesis, as was observed for diets high in RUP . The data strongly suggest that increased RUP per se in dairy cow diets, which often results in a decrease in RDP and a change in absorbed AA profiles, does not consistently improve lactational performance. Biochemistry, 1999 Jan 5, 38(1), 247 - 56 Two short-chain dehydrogenases confer stereoselectivity for enantiomers of epoxypropane in the multiprotein epoxide carboxylating systems of Xanthobacter strain Py2 and Nocardia corallina B276; Allen JR et al.; Epoxide carboxylase from the bacterium Xanthobacter strain Py2 is a multicomponent enzyme system which catalyzes the pyridine nucleotide-dependent carboxylation of aliphatic epoxides to beta-ketoacids as illustrated by the reaction epoxypropane + CO2 + NADPH + NAD+ --> acetoacetate + H+ + NADP+ + NADH . The combination of four distinct proteins, designated components I-IV, are required for the reconstitution of epoxide carboxylase activity with racemic mixtures of short-chain (C3-C5) terminal epoxyalkanes . In this work, components III and IV of the epoxide carboxylase system are shown to confer specificity for epoxyalkane enantiomers . Components I-III supported the carboxylation of (R)-epoxypropane, while components I, II, and IV supported the carboxylation of (S)-epoxypropane . At fixed concentrations of components I and II, the rates of (R)- and (S)-epoxypropane carboxylation saturated with increasing concentrations of component III or IV to give identical maximal rates for the two epoxide substrates . (S)-Epoxypropane was an inactivator of (R)-epoxypropane carboxylation by components I- III, while (R)-epoxypropane was an inactivator of (S)-epoxypropane carboxylation by components I, II, and IV . These inactivating effects were fully reversed upon the addition of the correct complementing dehydrogenase component . Amino acid sequence analysis of components III and IV demonstrates that they belong to the short-chain dehydrogenase/reductase (SDR) family of enzymes . Both components contain highly conserved residues within the coenzyme binding fold and catalytic regions found in SDR enzymes . Components III and IV are proposed to catalyze the NAD+-dependent abstraction of a hydride from a chiral secondary alcohol-like intermediate bound to the active site component of the enzyme system to form the corresponding beta-ketone intermediate . A multicomponent epoxide carboxylase system was purified to homogeneity from Nocardia corallina B276, a bacterium phylogenetically unrelated to Xanthobacter Py2, and found to consist of four proteins with functions identical to those of the Xanthobacter Py2 system . The stereoselective dehydrogenases of the Xanthobacter epoxide carboxylase system were able to substitute for the corresponding components of the N . corallina system when using (R)- and (S)-epoxypropane as substrates, and vice versa . These results provide the first demonstration of the involvement of stereospecific dehydrogenases in aliphatic epoxide metabolism and provide new insights into microbial strategies for the utilization of chiral organic molecules. Curr Opin Biotechnol, 1998 Dec, 9(6), 618 - 23 Implications of sequencing bacterial genomes for pathogenesis and vaccine development; Saunders NJ et al.; Improvements in homology search methodology and functional predictions are being complemented by the increase in the volume of sequence data with which comparative analyses can be performed . The experimental methods needed for investigation of gene function and expression in a variety of model systems of infection continue to develop . The identification of surface-exposed microbial structures and their conservation in natural populations of pathogenic species offers prospects for developing novel vaccines . A major challenge is the development of efficient screening methods to select the most promising candidates, such as immunisation with DNA. Science, 1999 Jan 15, 283(5400), 404 - 6 Diminishing returns from mutation supply rate in asexual populations; Arjan JA et al.; Mutator genotypes with increased mutation rates may be especially important in microbial evolution if genetic adaptation is generally limited by the supply of mutations . In experimental populations of the bacterium Escherichia coli, the rate of evolutionary adaptation was proportional to the mutation supply rate only in particular circumstances of small or initially well-adapted populations . These experiments also demonstrate a "speed limit" on adaptive evolution in asexual populations, one that is independent of the mutation supply rate. J Immunol, 1999 Jan 1, 162(1), 366 - 71 CD1-restricted microbial lipid antigen-specific recognition found in the CD8+ alpha beta T cell pool; Rosat JP et al.; It is generally accepted that TCR alphabeta+ CD8+ T cells recognize immunogenic peptides bound to MHC-encoded class I molecules . This recognition is a major component of the cellular response mediating immune protection and recovery from viral infections and from certain intracellular bacterial infections . Here, we report two human CD8+ TCR alphabeta+ T cell lines specific for Mycobacterium tuberculosis Ags presented in the context of CD1a or CD1c Ag-presenting molecules . These T cells recognize lipid Ags and display cytotoxicity as well as strong Th cell type I cytokine responses . By extending presentation by the CD1 system to the major TCR alphabeta+ CD8+ T cell pool, this system gains wider applicability beyond the double negative subset of T cells previously shown to have this reactivity . This implies that previous assumptions about the role of CD8+ T cells in microbial immunity may require revision as the relative proportions of CD1-restricted and MHC class I-restricted CD8+ T cells are further defined. Blood, 1999 Jan 15, 93(2), 590 - 8 Definition of dendritic cell subpopulations present in the spleen, Peyer's patches, lymph nodes, and skin of the mouse; Anjuere F et al.; Dendritic cells (DC) are highly efficient antigen-presenting cells (APC) that have an essential function in the development of immune responses against microbial pathogens and tumors . Although during the past few years our understanding of DC biology has remarkably increased, a precise characterization of the different DC subpopulations remains to be achieved with regard to their phenotype and lineage relationships . In this report, we have extensively studied the DC subpopulations present in the thymus, spleen, Peyer's patches, lymph nodes (LN) and skin of the mouse . Thymus DC and 60% spleen DC have a lymphoid DC phenotype, ie, CD8(+) DEC-205(high) Mac-1(low), whereas 40% spleen DC have a myeloid DC phenotype, ie, CD8(-) DEC-205(low) Mac-1(high) . Both CD8(+) and CD8(-) DC are leukocyte function-associated antigen-1 (LFA-1)high and highly adherent . Within Peyer's patches the majority of DC correspond to the CD8(+) DEC-205(high) Mac-1(low) lymphoid category . In the LN, together with CD8(+) and CD8(-) DC, an additional nonadherent CD8(int) LFA-1(int) subpopulation with lymphoid DC characteristics is described . Finally, in the skin both epidermal Langerhans cells (LC) and dermal DC are CD8(-)DEC-205(high) Mac-1 (high), and do not express LFA-1 . Interestingly, LC migration experiments indicate that LC underwent the upregulation of CD8 and LFA-1 upon migration to the LN, supporting the hypothesis that LC belong to the CD8(+) lymphoid lineage. Diagn Microbiol Infect Dis, 1998 Nov, 32(3), 165 - 76 Comparative study of five different techniques for epidemiological typing of Escherichia coli O157; Grif K et al.; A set of 47 Austrian human, food, and veterinary Escherichia coli O157:H7 isolates was used to evaluate five different epidemiological typing methods . Ribotyping using an automated microbial characterization system (RiboPrinter) was not suitable for detection of epidemiological relatedness . All but one E . Coli strain were typeable by phage typing . Random amplified polymorphic DNA-PCR fingerprinting was performed using primer M13 containing the sequence 5'-GAG GGT GGC GGT TCT-3' and primer 1247 (5'-AAGAGCCCGT-3') . Although both methods recognized only two clusters, both dendrograms grouped most of the EHEC O157 isolates into epidemiologically related subgroups . Pulsed-field gel electrophoresis of XbaI digested total DNA was a valuable subtyping system . We found that major differences can exist between results of multiple subtyping methods . E . coli O157 isolates should not be classified as epidemiologically related or nonrelated on the basis of a single typing method alone. Dig Dis Sci, 1998 Dec, 43(12), 2733 - 7 Halitosis and Helicobacter pylori: a possible relationship; Ierardi E et al.; With the aim of investigating a possible relationship between "objective" halitosis (established by sulfide levels in the breath) and Helicobacter pylori, we performed a study in 58 dyspeptic patients reported to suffer from "bad breath." Furthermore, we evaluated the effects on halitosis of eradication therapy (only for H . pylori-positive patients) and chlorhexidine antiseptic mouth rinses (in all patients) . Sulfide compound assay indicated objective halitosis in 52/58 patients, 30 of whom were positive and 22 negative for H . pylori . In 19/30 eradication by double therapy provoked a decrease to below the cutoff value of sulfide levels in 15 . In the other 11 of the 30 subjects, in whom H . pylori positivity persisted, halitosis parameters did not change . Chlorexidine reduced sulfides to below the cutoff value in 16/22 H . pylori-negative patients, but did not provoke any change in the 11 unsuccessfully treated H . pylori-positive subjects . In these, objective halitosis disappeared only after a successful eradication by triple therapy (9/11) . Our results show a possible association between halitosis and H . pylori since bacterial eradication may resolve the symptom . Antiseptic mouthwashes may be effective only in absence of H . pylori, when halitosis may be due to oral putrefactive microbial activity . In a small number of subjects the cause and treatment of halitosis need to be clarified. J Enzyme Inhib, 1998 Feb, 13(1), 41 - 55 Inhibition of DNA topoisomerases by microbial inhibitors; Suzuki K et al.; New inhibitors of DNA topoisomerase named 2280-DTI and 2890-DTI have been discovered in the culture filtrates of Micromonospora sp . strain No . 2280 and Streptomyces sp . strain No . 2890, respectively . Both inhibitors were purified from each culture filtrate by column chromatography on Diaion, Dowex and gel filtration . Both inhibitors were thermostable acidic substances with high molecular weight and inhibited topoisomerase I in a non-competitive manner . They differed from well-known inhibitors of topoisomerases such as camptothecin and doxorubicin, which inhibit the DNA rejoining reaction of the enzyme by intercalation into DNA strands or stabilizing the cleavable complex (enzyme-DNA reaction intermediate) . 2280-DTI and 2890-DTI did not intercalate into DNA strands and also had no ability to stabilize the cleavable complex . It is suggested that 2280-DTI and 2890-DTI inhibit the DNA breaking and rejoining reactions of topoisomerase by direct action on the enzyme molecule. Theor Popul Biol, 1998 Dec, 54(3), 257 - 69 Acidic deposition, plant pests, and the fate of forest ecosystems; Gragnani A et al.; We present and analyze a nonlinear dynamical system modelling forest-pests interactions and the way they are affected by acidic deposition . The model includes mechanisms of carbon and nitrogen exchange between soil and vegetation, biomass decomposition and microbial mineralization, and defoliation by pest grazers, which are partially controlled by avian or mammalian predators . Acidic deposition is assumed to directly damage vegetation, to decrease soil pH, which in turn damages roots and inhibits microbial activity, and to predispose trees to increased pest attack . All the model parameters are set to realistic values except the inflow of protons to soil and the predation mortality inflicted to the pest which are allowed to vary inside reasonable ranges . A numerical bifurcation analysis with respect to these two parameters is carried out . Five functioning modes are uncovered: (i) pest-free equilibrium; (ii) pest persisting at endemic equilibrium; (iii) forest-pest permanent oscillations; (iv) bistable behavior with the system converging either to pest-free equilibrium or endemic pest presence in accordance with initial conditions; (v) bistable behavior with convergence to endemic pest presence or permanent oscillations depending on initial conditions . Catastrophic bifurcations between the different behavior modes are possible, provided the abundance of predators is not too small . Numerical simulation shows that increasing acidic load can lead the forest to collapse in a short time period without important warning signals . J Autoimmun, 1998 Dec, 11(6), 621 - 33 TCR-Vbeta usage in the thymus and blood of myasthenia gravis patients; Navaneetham D et al.; In myasthenia gravis (MG) the muscle acetylcholine receptor (AChR) is the target of an autoimmune response . The anti-AChR response may originate in the thymus, which is abnormal in most MG patients and contains anti-AChR T and B cells . Microbial superantigens (sAg) may trigger autoimmune responses and in this study we sought clues as to whether sAg play a role in the pathogenesis of MG . We investigated the frequency of use of the different TCR Vbeta families by the thymus and blood T cells in MG patients and in control subjects, using a multi-primer PCR assay . Identical TCR-Vbeta usage was found in the thymi of MG patients and controls, except Vbeta2, which showed a small increase in MG patients' thymi . Blood T cells of MG patients used Vbeta4, Vbeta6, Vbeta15, Vbeta16 and Vbeta24 significantly more than those of the controls . Vbeta4 and Vbeta6 are the gene families most frequently used by anti-AChR CD4(+) cells in MG patients . Blood T cells from MG patients used Vbeta12, Vbeta14, Vbeta17 and Vbeta18 significantly less than controls . MG patients used Vbeta4 and Vbeta6 significantly more in the blood than in the thymus, while the opposite occurred for Vbeta7, Vbeta12 and Vbeta14 . Controls used Vbeta17 more and Vbeta24 less in the blood than in the thymus . The preferential expansion of Vbeta4 and Vbeta6 in MG patients might reflect the immunodominance of certain AChR epitopes, or the action of a sAg outside the thymus . The minimal differences in the TCR-Vbeta usage in the blood and thymus of control subjects might be due to expansion of T cell clones specific for common antigens . Identical Vbeta usage in the thymi of MG patients and controls does not support an important role of the thymus as the location of anti-AChR sensitization when MG is clinically evident . The differences observed in the Vbeta usage in blood and thymi of MG patients are likely to be due to preferential Vbeta usage by the anti-AChR T cells in the blood . J Infect Dis, 1999 Feb, 179(2), 329 - 36 Prolonged suppression of human immunodeficiency virus type 1 (HIV-1) viremia in persons with advanced disease results in enhancement of CD4 T cell reactivity to microbial antigens but not to HIV-1 antigens; Rinaldo CR Jr et al.; CD4 T cell responses were studied for >2 years in 27 zidovudine-experienced patients with advanced human immunodeficiency virus type 1 (HIV-1) infection who received triple combination drug therapy with indinavir, zidovudine and lamivudine or zidovudine plus lamivudine or zidovudine alone for 24-42 weeks before switching to the three-drug therapy . Subjects initially given the three drugs had viremia suppressed to undetectable levels and increases in T cell proliferative and cytokine responses to microbial antigens through 2 years of follow-up . Patients receiving the triple-drug therapy after either indinavir or zidovudine-lamivudine treatment had similar increases in T cell responses only if they also had suppression of virus load . CD4 T cell reactivity to HIV-1 antigens was not restored . Prolonged indinavir-zidovudine-lamivudine treatment has significant but incomplete enhancing effects on CD4 T cell reactivity, which could be important in host control of microbial and persistent HIV-1 infections. Int J Cancer Suppl, 1998, 11, 29 - 33 Review of the evidence for an association between infant feeding and childhood cancer; Davis MK; To assess the association between infant feeding and childhood cancer, a qualitative review of 9 published case-control studies was undertaken . The results of this synthesis suggest that children who are never breast-fed or are breast-fed short-term have a higher risk than those breast-fed for > or = 6 months of developing Hodgkin's disease (HD), but not non-Hodgkin's lymphoma or acute lymphoblastic leukemia . HD has features of a complex cellular immune disorder and of chronic infection . Human milk contains an extensive array of anti-microbial activity and appears to stimulate early development of the infant immune system . Artificially fed infants negotiate exposure to infectious agents without the benefits of this immunologic armament and do not do as well as breast-fed infants in resisting infection . Thus, human milk may make the breast-fed infant better able to negotiate future carcinogenic insults by modulating the interaction between infectious agents and the developing infant immune system or by directly affecting the long-term development of the infant immune system . Further research should attempt to confirm the association between infant feeding and HD in large, population-based, case-control studies . Improved measurement of infant feeding must be addressed if future studies are to advance our understanding of this association . In addition, studies of specific measures of immunity, particularly of cellular immune responses, should be conducted in populations of breast-fed and non-breast-fed young children. Appl Environ Microbiol, 1999 Jan, 65(1), 231 - 40 Population dynamics of chesapeake bay virioplankton: total-community analysis by pulsed-field gel electrophoresis Wommack KE, Ravel J, Hill RT, Chun J, Colwell RR. Recognition of viruses as the most abundant component of aquatic microbial communities has stimulated investigations of the impact of viruses on bacterio- and phytoplankton host communities . From results of field studies to date, it is concluded that in most aquatic environments, a reduction in the number of bacteria on a daily basis is caused by viral infection . However, the modest amount of in situ virus-mediated mortality may be less significant than viral infection serving to maintain clonal diversity in the host communities directly, through gene transmission (i.e., transduction), and indirectly, by elimination of numerically dominant host species . If the latter mechanism for controlling community diversity prevails, then the overall structure of aquatic viral communities would be expected to change as well over short seasonal and spatial scales . To determine whether this occurs, pulsed-field gel electrophoresis (PFGE) was used to monitor the population dynamics of Chesapeake Bay virioplankton for an annual cycle (1 year) . Virioplankton in water samples collected at six stations along a transect running the length of the bay were concentrated 100-fold by ultrafiltration . Viruses were further concentrated by ultracentrifugation, and the concentrated samples were embedded in agarose . PFGE analysis of virus DNA in the agarose plugs yielded several distinct bands, ranging from 50 to 300 kb . Principal-component and cluster analyses of the virus PFGE fingerprints indicated that changes in virioplankton community structure were correlated with time, geographical location, and extent of water column stratification . From the results of this study, it is concluded that, based on the dynamic nature of the Chesapeake Bay virioplankton community structure, the clonal diversity of bacterio- and phytoplankton host communities is an important component of the virus community. Appl Environ Microbiol, 1999 Jan, 65(1), 198 - 205 Changes in quinone profiles of hot spring microbial mats with a thermal gradient Hiraishi A, Umezawa T, Yamamoto H, Kato K, Maki Y. The respiratory and photosynthetic quinones of microbial mats which occurred in Japanese sulfide-containing neutral-pH hot springs at different temperatures were analyzed by spectrochromatography and mass spectrometry . All of the microbial mats that developed at high temperatures (temperatures above 68 degreesC) were so-called sulfur-turf bacterial mats and produced methionaquinones (MTKs) as the major quinones . A 78 degreesC hot spring sediment had a similar quinone profile . Chloroflexus-mixed mats occurred at temperatures of 61 to 65 degreesC and contained menaquinone 10 (MK-10) as the major component together with significant amounts of either MTKs or plastoquinone 9 (PQ-9) . The sunlight-exposed biomats growing at temperatures of 45 to 56 degreesC were all cyanobacterial mats, in which the photosynthetic quinones (PQ-9 and phylloquinone) predominated and MK-10 was the next most abundant component in most cases . Ubiquinones (UQs) were not found or were detected in only small amounts in the biomats growing at temperatures of 50 degreesC and above, whereas the majority of the quinones of a purple photosynthetic mat growing at 34 degreesC were UQs . A numerical analysis of the quinone profiles was performed by using the following three parameters: dissimilarity index (D), microbial divergence index (MDq), and bioenergetic divergence index (BDq) . A D matrix tree analysis showed that the hot spring mats consisting of the sulfur-turf bacteria, Chloroflexus spp., cyanobacteria, and purple phototrophic bacteria formed distinct clusters . Analyses of MDq and BDq values indicated that the microbial diversity of hot spring mats decreased as the temperature of the environment increased . The changes in quinone profiles and physiological types of microbial mats in hot springs with thermal gradients are discussed from evolutionary viewpoints. J Exp Med, 1999 Jan 4, 189(1), 195 - 205 Molecular recognition of lipid antigens by T cell receptors; Grant EP et al.; The T cell antigen receptor (TCR) mediates recognition of peptide antigens bound in the groove of major histocompatibility complex (MHC) molecules . This dual recognition is mediated by the complementarity-determining residue (CDR) loops of the alpha and beta chains of a single TCR which contact exposed residues of the peptide antigen and amino acids along the MHC alpha helices . The recent description of T cells that recognize hydrophobic microbial lipid antigens has challenged immunologists to explain, in molecular terms, the nature of this interaction . Structural studies on the murine CD1d1 molecule revealed an electrostatically neutral putative antigen-binding groove beneath the CD1 alpha helices . Here, we demonstrate that alpha/beta TCRs, when transferred into TCR-deficient recipient cells, confer specificity for both the foreign lipid antigen and CD1 isoform . Sequence analysis of a panel of CD1-restricted, lipid-specific TCRs reveals the incorporation of template-independent N nucleotides that encode diverse sequences and frequent charged basic residues at the V(D)J junctions . These sequences permit a model for recognition in which the TCR CDR3 loops containing charged residues project between the CD1 alpha helices, contacting the lipid antigen hydrophilic head moieties as well as adjacent CD1 residues in a manner that explains antigen specificity and CD1 restriction. J Exp Med, 1999 Jan 4, 189(1), 1 - 12 Human non-germinal center B cell interleukin (IL)-12 production is primarily regulated by T cell signals CD40 ligand, interferon gamma, and IL-10: role of B cells in the maintenance of T cell responses; Schultze JL et al.; Interleukin (IL)-12 is expressed mainly in antigen-presenting cells after challenge with microbial material or after CD40 activation . Although IL-12 was cloned from human Epstein-Barr virus (EBV)-transformed B cell lines, surprisingly, CD40 ligation on murine B cells did not lead to IL-12 production, suggesting that murine B cells do not produce IL-12 . Here we demonstrate that a subset of human tonsillar B cells can be induced to express and secrete bioactive IL-12 . The major stimulus to produce IL-12 in human B cells was CD40 ligation . In contrast, B cell receptor cross-linking did not induce IL-12 . Expression of IL-12 after CD40 activation was restricted to CD38(-)IgD+/- non-germinal center (non-GC) B cells . CD40 ligation and interferon (IFN)-gamma exhibited synergistic effects on IL-12 production, whereas IL-10 abrogated and IL-4 significantly inhibited IL-12 production by these B cells . In contrast to IL-12, production of IL-6 is conversely regulated, leading to significant increase after CD40 ligation in the presence of the T helper type 2 (Th2) cytokine IL-4 . Cord blood T cells skewed towards either a Th1 or a Th2 phenotype maintained their cytokine expression pattern when restimulated with allogeneic resting B cells . Blockade of CD40 and/or IL-12 during T-B interaction significantly reduced IFN-gamma production by the T cells . This suggests a model whereby B cells produce either IL-12 or IL-6 after contact with T cells previously differentiated towards Th1 or Th2 . Furthermore, IL-12 and IL-6 might provide a positive feedback during cognate T-B interactions, thereby maintaining T cells' differentiation pattern during amplification of the immune response. Eur J Biochem, 1998 Dec 1, 258(2), 623 - 56 Identification of highly fucosylated N-linked oligosaccharides from the human parotid gland; Guile GR et al.; The glycosylation of a number of constituents of human saliva is known to modify its biological roles, such as its lubricating properties and binding of microbial flora . Gillece-Castro et al . {Gillece-Castro, B . L., Prakobphol, A., Burlingame, A . L., Leffler, H . & Fisher, S . J . (1991) J . Biol . Chem . 266, 17358-17368} have proposed that the major glycan on the salivary proline-rich glycoproteins is a trifucosylated biantennary sugar with one difucosylated and one unfucosylated antenna . Furthermore, they proposed that the non-fucosylated antenna mediated adherence to a peridontal pathogen, Fusobacterium nucleatum . The detailed structures and roles of other highly fucosylated glycans that co-exist in the parotid gland are not fully known . In view of the influence of outer-arm fucosylation on carbohydrate recognition processes in general, this paper reports the use of a combination of HPLC (normal and reversed phase), matrix-assisted laser-desorption/ionisation (MALDI) mass spectrometry and exoglycosidase digestions to dissect the detailed structures of the most abundant of these polyfucosylated glycans . For measurement of reversed-phase HPLC retention times, new calibration units were used which paralleled the glucose units used for normal-phase HPLC . These differed in that the difference in retention times were compared with those derived from a ladder of 2-aminobenzamide-labelled arabinose oligomers instead of the corresponding oligomers from partially hydrolysed dextran . Over sixty neutral sugars were identified from the parotid gland and many of these were additionally found substituted with sialic acid (both alpha2-3-linked and alpha2-6-linked) and sulphate . These glycans were mainly bi- and tri-antennary sugars with up to five and seven fucose residues respectively, containing fucose alpha1-3-linked to the outer-arm GlcNAc residues and alpha1-2-linked to the galactose . All fucosylated structures contained a core (alpha1-6-linked) fucose . The detailed structure of the trifucosylated biantennary glycan was confirmed, together with the structures of another 12 fucosylated biantennary glycans . Smaller amounts of hybrid and tetraantennary structures were also found and bisected glycans were shown to be constituents of parotid glycoproteins for the first time . Acidic glycans were mainly substituted with sialic acid . Most were monosialylated as the presence of fucose on the antennae was found to suppress the addition of extra sialic acid moieties . The possible functional significance of highly fucosylated N-glycans is discussed in relation to their modification of the availability of other non-reducing terminal monosaccharides for recognition processes. Appl Environ Microbiol, 1999 Jan, 65(1), 283 - 6 Phylogenetic analysis of an anaerobic, trichlorobenzene-transforming microbial consortium; von Wintzingerode F et al.; A culture-independent phylogenetic survey for an anaerobic trichlorobenzene-transforming microbial community was carried out . Small-subunit rRNA genes were PCR amplified from community DNA by using primers specific for Bacteria or Euryarchaeota and were subsequently cloned . Application of a new hybridization-based screening approach revealed 51 bacterial clone families, one of which was closely related to dechlorinating Dehalobacter species . Several clone sequences clustered to rDNA sequences obtained from a molecular study of an anaerobic aquifer contaminated with hydrocarbons and chlorinated solvents (Dojka et al., Appl . Env . Microbiol . 64:3869-3877, 1998). Nature, 1998 Dec 17, 396(6712), 695 - 9 An asparaginyl endopeptidase processes a microbial antigen for class II MHC presentation; Manoury B et al.; Foreign protein antigens must be broken down within endosomes or lysosomes to generate suitable peptides that will form complexes with class II major histocompatibility complex molecules for presentation to T cells . However, it is not known which proteases are required for antigen processing . To investigate this, we exposed a domain of the microbial tetanus toxin antigen (TTCF) to disrupted lysosomes that had been purified from a human B-cell line . Here we show that the dominant processing activity is not one of the known lysosomal cathepsins, which are generally believed to be the principal enzymes involved in antigen processing, but is instead an asparagine-specific cysteine endopeptidase . This enzyme seems similar or identical to a mammalian homologue of the legumain/haemoglobinase asparaginyl endopeptidases found originally in plants and parasites . We designed competitive peptide inhibitors of B-cell asparaginyl endopeptidase (AEP) that specifically block its proteolytic activity and inhibit processing of TTCF in vitro . In vivo, these inhibitors slow TTCF presentation to T cells, whereas preprocessing of TTCF with AEP accelerates its presentation, indicating that this enzyme performs a key step in TTCF processing . We also show that N-glycosylation of asparagine residues blocks AEP action in vitro . This indicates that N-glycosylation could eliminate sites of processing by AEP in mammalian proteins, allowing preferential processing of microbial antigens. DNA Res, 1998 Oct 30, 5(5), 261 - 9 Phosphate transporter gene family of Arabidopsis thaliana; Okumura S et al.; Using a high-affinity phosphate transporter gene of Arabidopsis thaliana, PHT1, as a probe, three Arabidopsis homologs were isolated, named PHT4, PHT5 and PHT6, in addition to the previously isolated PHT2 and PHT3 . The amino acid sequences deduced from the three nucleotides were 32-42% homologous with microbial phosphate transporters of Saccharomyces cerevisiae (PHO84), Neurospora crassa (PHO-5) and Glomus versiforme (GvPT) . PHT1, PHT2, PHT3 and PHT6 were clustered in a 25-kbp region of chromosome V . PHT1 and PHT4 transcripts were detected in roots . Interestingly, suspension-cultured cells expressed only PHT4 . PHT4 and PHT5 located within a genetic distance of 6.4 cM on chromosome II, and were close to a phosphate accumulation mutant pho2 . Genomic sequencing revealed no difference in the sequences of the two genes in both pho2 and wild-type . The PHT4 transcript was expressed at similar levels in the mutant and wild-type . These results demonstrate that neither PHT4 nor PHT5 is allelic to PHO2. Nephrol Dial Transplant, 1998, 13 Suppl 7, 55 - 60 Which level of cytokine production is critical in haemodialysis? Cappelli G, DiFelice A, Perrone S, Ballestri M, Bonucchi D, Savazzi AM, Ciuffreda A, Lusvarghi E. Monocyte activation with cytokine production is a well known event in the course of dialysis treatment but its relation to symptoms of haemodialysis or long-term pathological changes in chronic dialysis patients is still under discussion . Cytokine production depends on the balance between inducers and inhibitors while effects rely on the peculiar uraemic environment and cell metabolism . 'Foot-prints' for monocyte activation have been found, but no marker for clinical symptoms has been demonstrated clearly . In this scenario it is almost impossible to link a specific symptom to a definite stimulus such as dialysate microbial contamination or membrane complement generation . The topics discussed in this paper include cytokines synthesis modulation factors, levels in haemodialysis patients, and results of finding markers of clinical relevance . Special attention is paid to microbial contamination of dialysis fluid with analysis of cytokine inducing substances in commercial sterile solutions . Data on cytokine synthesis and activity in the aged are also discussed, with special regard to the haemodialysis setting. J Biochem Biophys Methods, 1998 Nov 18, 37(3), 117 - 29 New zwitterionic butanesulfonic acids that extend the alkaline range of four families of Good buffers: evaluation for use in biological systems; Thiel T et al.; Four new zwitterionic butanesulfonic acid buffers that are structurally related to four families of Good buffers were evaluated for use in biological systems . These buffers, with pKa values from 7.6 to 10.7, were compared with a variety of other buffers from the same family and with unrelated buffers to determine their effect on enzyme activity and on microbial growth . The activity of four enzymes with optimum pH values in the alkaline range were tested: beta-galactosidase, esterase, phosphodiesterase and alkaline phosphatase . In general, all the Good buffers, including the new butanesulfonic acid buffers, gave good activity; however, there was variation in activity of certain enzymes with certain buffers . Tris, glycine, and phosphate buffers typically showed variation in activity compared to the family of Good buffers . beta-Galactosidase, in particular, showed greater activity with Good buffers than with phosphate or Tris buffers . Similarly, growth of seven bacterial strains was consistent, with a few exceptions, for all the Good family of buffers with Tris often inhibiting growth . Quantitation of alkaline phosphatase conjugated to antibodies is an important tool in many applications in molecular biology . Several Good buffers gave good signals when compared with Tris at pH 9.5 for detection of proteins using alkaline phosphatase-conjugated antibodies. J Clin Periodontol, 1998 Dec, 25(12), 988 - 93 Sonic and mechanical toothbrushes . An in vitro study showing altered microbial surface structures but lack of effect on viability; MacNeill S et al.; The purpose of the present study was to compare the in vitro effects of a mechanical and a sonic toothbrush on the viability of Actinomyces viscosus, the rationale being that induction of irreparable microbial damage resulting from aggressive mechanical action or sonic energy, may inhibit or disrupt the process of successional colonization . Cultures of A . viscosus were grown to a standardized optical density and subdivided into 3 treatment groups of 20 specimens each . Treatment groups consisted of an untreated control and exposure to a mechanical or sonic toothbrush for 15, 30, 45, and 60 s . Subsequent to the prescribed treatment, samples were taken from each specimen dish, subcultured, and the number of CFUs determined . Additional samples were obtained for negative staining and examination by electron microscopy . The mean number of CFUs for each treatment group at each treatment interval were statistically analyzed by ANOVA and multiple pairwise comparisons . Results showed a significant main effect for toothbrushes (p<0.0001) and exposure time (p<0.01), but only marginal significance for the interaction of toothbrush with exposure time (p<0.055) . Post-hoc tests showed a significantly greater number of CFUs for the sonic toothbrush compared to both the untreated control and mechanical toothbrush groups . Electron microscopic examination revealed a decrease in aggregation tendency and loss of fimbriae in the sonic toothbrush group . Based on the lack of morphologic evidence that would indicate cell damage and the increase in CFUs over that of the control group, it appeared that neither the mechanical or sonic toothbrushes affected cell viability. J Nutr, 1998 Dec, 128(12), 2473 - 87 Long-chain polyunsaturated fatty acid levels in formulae influence deposition of docosahexaenoic acid and arachidonic acid in brain and red blood cells of artificially reared neonatal rats; Ward GR et al.; We studied the effects of dietary long-chain polyunsaturated fatty acids (PUFA) on the fatty acid composition of the brain and red blood cells in gastrostomized rat pups reared artificially from postnatal Days 5-18 . These pups were fed rat milk substitutes in which the fat comprised 10% linoleic acid and 1% alpha-linolenic acid and, using a 3 x 3 factorial design, one of three levels of both arachidonic acid (AA) and docosahexaenoic acid (DHA) supplied as single cell microbial oils (0.0, 0.4 and 2.4% fatty acids) . A tenth group was reared by nursing dams . The fatty acid composition of the phosphatidylethanolamine (PE) and phosphatidylserine/phosphatidylinositol (PS/PI) phospholipids in the brain and red blood cells on Day 18 reflected the dietary composition in that pups receiving long-chain supplementation of each had higher levels of the supplemented PUFA, but lower levels of the other, relative to unsupplemented groups . In contrast to these results, there were few changes in the brain in phosphatidylcholine (PC) phospholipids whereas, in the red blood cells, changes in PC were similar to those in PE and PS/PI . Regression analyses showed that DHA levels in the brain correlated more closely with those of the red blood cells than did AA levels . The results of this study indicate that, although supplementation of formula with AA or DHA during the period of rapid brain development in rats increases deposition of the long-chain PUFA in the developing tissues, each also affects the levels of the other. Scand J Gastroenterol, 1998 Nov, 33(11), 1170 - 4 Serosal but not mucosal endotoxin exposure increases intestinal permeability in vitro in the rat; Osman NE et al.; BACKGROUND: Microbial endotoxins are normally present in the gut, usually without apparent harmful effects, whereas systemically administered endotoxin impairs the mucosal barrier function . Our aim was to investigate whether in vitro exposure to bacterial lipopolysaccharide (LPS) could affect the intestinal barrier properties of the rat small intestine . METHODS: Small-intestinal segments from rats were mounted in Ussing diffusion chambers, and the mucosal to serosal permeation of the marker molecules bovine serum albumin (BSA) and 51Cr-ethylenediaminetetraacetic acid (EDTA) was measured after addition of LPS to the mucosal or serosal side . RESULTS: Mucosal exposure to LPS (0.01, 0.05, 0.25 mg/ml) had no effects on the permeation of BSA and 51Cr-EDTA, whereas when added to the serosal side at 0.05 or 0.25 mg/ml, LPS increased the marker permeation . CONCLUSION: Serosal LPS exposure in vitro increased the intestinal permeability to the different-sized markers, whereas mucosal LPS did not, indicating that the mechanisms leading to intestinal barrier impairment can be initiated in the intestinal wall itself. Mol Biol Evol, 1998 Dec, 15(12), 1658 - 73 Granule-bound starch synthase: structure, function, and phylogenetic utility; Mason-Gamer RJ et al.; Interest in the use of low-copy nuclear genes for phylogenetic analyses of plants has grown rapidly, because highly repetitive genes such as those commonly used are limited in number . Furthermore, because low-copy genes are subject to different evolutionary processes than are plastid genes or highly repetitive nuclear markers, they provide a valuable source of independent phylogenetic evidence . The gene for granule-bound starch synthase (GBSSI or waxy) exists in a single copy in nearly all plants examined so far . Our study of GBSSI had three parts: (1) Amino acid sequences were compared across a broad taxonomic range, including grasses, four dicotyledons, and the microbial homologs of GBSSI . Inferred structural information was used to aid in the alignment of these very divergent sequences . The informed alignments highlight amino acids that are conserved across all sequences, and demonstrate that structural motifs can be highly conserved in spite of marked divergence in amino acid sequence . (2) Maximum-likelihood (ML) analyses were used to examine exon sequence evolution throughout grasses . Differences in probabilities among substitution types and marked among-site rate variation contributed to the observed pattern of variation . Of the parameters examined in our set of likelihood models, the inclusion of among-site rate variation following a gamma distribution caused the greatest improvement in likelihood score . (3) We performed cladistic parsimony analyses of GBSSI sequences throughout grasses, within tribes, and within genera to examine the phylogenetic utility of the gene . Introns provide useful information among very closely related species, but quickly become difficult to align among more divergent taxa . Exons are variable enough to provide extensive resolution within the family, but with low bootstrap support . The combined results of amino acid sequence comparisons, maximum-likelihood analyses, and phylogenetic studies underscore factors that might affect phylogenetic reconstruction . In this case, accommodation of the variable rate of evolution among sites might be the first step in maximizing the phylogenetic utility of GBSSI. Ned Tijdschr Geneeskd, 1998 Oct 10, 142(41), 2242 - 5 {Infections and aging}; Cools HJ et al.; Elderly people are exposed to infectious risks in ways different from younger people . These risks relate to environment, transmission routes and vectors, microbial colonisation of body surfaces and quality of host defence . Admission to a nursing home or a hospital may easily lead to colonisation with (resistant) potentially pathogenic micro-organisms, while pre-existing morbidity, medication and functional disability impair the quality of host defence, to a greater degree than the process of aging . In general, infections have a great impact on the elderly patient . Not only are infections in the elderly often serious, but they often have a deleterious effect on comorbidity and functional ability . Infections in elderly people with serious comorbidity face the physician with the dilemma how far to go with diagnostic procedures and therapy. Endod Dent Traumatol, 1998 Jun, 14(3), 127 - 32 The effect of systemic tetracycline on resorption of dried replanted dogs' teeth; Sae-Lim V et al.; The use of systemic penicillin after an avulsion injury has been recommended to decrease the occurrence of resorption complications . Tetracycline antibiotics have been reported to possess anti-resorptive properties in addition to their anti-microbial actions . The purpose of this study was to evaluate histologically the effect of systemically administered tetracycline and amoxicillin on the inhibition of resorption due to attachment damage after replantation of dogs' teeth . Thirty-one roots from the teeth of four beagle dogs were endodontically treated to inhibit subsequent inflammatory root resorption of pulpal origin . They were then extracted and left to bench dry for 1 h to ensure severe periodontal ligament damage before replantation . For the teeth in the experimental groups, two dogs were given tetracycline hydrochloride and the other two dogs were given amoxicillin, administered orally, on the day of extraction/replantation and for the following 6 days . The control group were teeth in these animals treated in the same manner but where no antibiotics had been given . After 12-16 weeks, the dogs were sacrificed and histological sections were prepared and evaluated for complete healing, inflammatory and replacement root resorption, and the groups were compared . It was shown that healing in the amoxicillin and the control groups was poor (10.90% and 11.28%, respectively), while for the tetracycline group, 35.45% showed complete healing . Individual teeth with over 50% complete healing sites were considered as having good healing, and significantly more of these teeth were found in the tetracycline group (5 of 11 teeth) compared to the amoxicillin (1 of 11 teeth) or control group (1 of 8 teeth). Biomed Environ Sci, 1998 Sep, 11(3), 218 - 25 Lindane degradation and effects on soil microbial activity; Farghaly M et al.; The degradation of U-14C-lindane in two Egyptian soils was determined in a three-month laboratory incubation . Lindane mineralization was slow and limited in both soils . Evolution of 14CO2 increased with time but only reached 3.5 to 5.5% of the initial 14C-concentration within 90 days . At that time both soils contained about 88% of the applied radiocarbon; 33% to 37% of the initial dose was unextractable and assumed bound to the soils . The methanol-extractable 14C primarily contained lindane with traces of minor metabolites . Radiorespirometry was used to evaluate the effect of lindane on soil microbial activity . Low concentrations of the insecticide initially supressed 14CO2 evolution from U-14C-glucose and microbial activity was significantly inhibited by 10 mg lindane/kg soil. Ann Agric Environ Med, 1998, 5(2), 147 - 53 Effects of exposure to grain dust in Polish farmers: work-related symptoms and immunologic response to microbial antigens associated with dust; Skorska C et al.; Medical examinations were performed in a group of 76 Polish farmers heavily exposed to grain dust during harvesting and threshing, and in a group of 63 healthy urban dwellers not exposed to organic dusts (controls) . The examinations included: interview concerning the occurrence of respiratory disorders and work-related symptoms, physical examination, lung function tests, and allergological tests comprising skin prick test with 4 microbial antigens associated with grain dust and agar-gel precipitation test with 12 microbial antigens . As many as 34 farmers (44.7%) reported the occurrence of work-related symptoms during harvesting and threshing . The most common was dry cough reported by 20 individuals (26.3%) . Dyspnoea was reported by 15 farmers (19.7%), tiredness by 12 (15.7%), chest tightness by 8 (10.5%), plugging of nose and hoarseness by 5 each (6 . 5%) . No control subjects reported these work-related symptoms . The mean spirometric values in the examined group of farmers were within the normal range, but a significant post-shift decrease of these values was observed after work with grain . The farmers showed a frequency of the positive early skin reactions to environmental allergens in the range of 10.8 - 45.5%, and a frequency of positive precipitin reactions in range of 3.9 - 40.8% . The control group responded to the majority of allergens with a significantly lower frequency of positive results compared to the farmers . The obtained results showed a high response of grain farmers to inhalant microbial allergens and indicate a potential risk of occupational respiratory diseases (such as allergic alveolitis, asthma, Organic Dust Toxic Syndrome) among this population Gene, 1998 Nov 26, 223(1-2), 55 - 66 Targeting and retrofitting pre-existing libraries of transposon insertions with FRT and oriV elements for in-vivo generation of large quantities of any genomic fragment; Wild J et al.; A procedure is described that converts the pre-existing transposon insertion libraries to a collection of 'pop-out' strains, each allowing generation of 20- to 100-kb genomic fragments directly from the genome . The procedure consists of two steps: (1) single transposon insertions are targeted and retrofitted with excision and amplification elements (FRT and oriV), by homologous recombination with an FRT-oriV-carrying plasmid; and (2) two retrofitted neighbouring transposons are brought together by P1 transduction . From each strain, a 20- to 100-kb genomic fragment, bound by a pair of retrofitted transposons, could be excised and amplified upon supplying in trans the excision (Flp) and replication (TrfA) functions . To enhance the efficiency of crossing-in the FRT-oriV cassette, we transiently increased the copy number of our retrofitting plasmids using a temperature-sensitive TrfA-supplying helper plasmid . Using FRT-oriV and helper plasmids, we retrofitted four Tn10KmR and three Tn10CmR insertions . Subsequently, the FRT-oriV retrofitted insertions were crossed with each other in pairs (KmRxCmR), using P1 phage transductions . The resulting CmRFRT-{28-65-kb}-KmRFRT strains were transformed with a plasmid expressing FLP and trfA genes from the tightly controlled Ptet promoter . Induction of this tightly repressed promoter by autoclaved chlortetracycline (cTc) resulted in the efficient excision and amplification of genomic fragments located between FRT sites, but only in productive strains, i.e . having two parallel FRTs . We have shown that genomic fragments of 28-, 40-, 50- and 65-kb were efficiently excised and amplified . Furthermore, we could convert non-productive strains (having FRTs in non-parallel orientation), to productive combination of parallel FRTs, because one of the FRT elements was flanked by two convergent loxP sites, and thus could be inverted by the Cre function delivered either by the P1 phage or by a specially constructed temperature-sensitive Plac-cre plasmid . Although several microbial genomes were recently sequenced, the described method will help in supplying large quantities of any genomic fragment (prepared without the conventional cloning and its artifacts) for refined sequence comparison among strains and species, and for further analysis of uncharacterized ORFs, various mutations, and regulatory elements or functions . The excised and circularized DNA fragments (plasmids) could be propagated like any other large plasmids but only in hosts that could supply the appropriate Rep function . Our original 'pop-out' method {Posfai et al . (1994) Nucleic Acids Res . 22, 2392-2398} was already employed for sequencing of the E . coli genome {Blattner et al . (1997) Science 277, 1453-1462} . Moreover, the Flp-mediated recombination between two FRT elements resulted in bacterial strains with large deletions (for parallel FRT orientations) or with large inversions (for inverted FRT orientations). J Exp Med, 1998 Dec 21, 188(12), 2381 - 6 A critical role of natural immunoglobulin M in immediate defense against systemic bacterial infection; Boes M et al.; To evaluate the role of natural immunoglobulin (Ig)M in the immediate response against microbial infection, we tested mutant mice that are deficient in secreted (s)IgM in an acute peritonitis model induced by cecal ligation and puncture (CLP) . 20% of wild-type mice died within 32 h of CLP, whereas 70% of sIgM-deficient mice died within the same time period . The increased susceptibility was associated with a reduced level of tumor necrosis factor (TNF)-alpha, a decreased neutrophil recruitment and an increased bacterial load in the peritoneum, and elevated levels of endotoxin and proinflammatory cytokines in the circulation . Resistance to CLP by sIgM-deficient mice was restored by reconstitution with polyclonal IgM from normal mouse serum . Reconstitution with a monoclonal IgM specific to phosphatidylcholine, a conserved cell membrane component, has a modest effect but a monoclonal IgM specific to phosphocholine is not protective . These findings demonstrate a critical role of natural IgM in the immediate defense against severe bacterial infection. Science, 1998 Dec 18, 282(5397), 2254 - 6 Microscale nutrient patches in planktonic habitats shown by chemotactic bacteria Blackburn N, Fenchel T, Mitchell J. Are nutrients available to microbial communities in micropatches long enough to influence growth and competition? And what are the sources of such patches? To answer these questions, the swimming behavior of chemotactic bacteria in seawater samples was examined . Clusters of bacteria formed in conjunction with cell lysis and excretion by protozoa . These point sources of nutrients spread into spherical patches a few millimeters in diameter and sustained swarms of bacteria for about 10 minutes . Within that time, a large proportion of the nutrients was encountered by bacteria, chemotactic and nonchemotactic alike . Chemotaxis is advantageous for bacteria using patches over a certain size. Eksp Klin Farmakol, 1998 Sep-Oct, 61(5), 24 - 6 {The evaluation of the action of microbial enzyme preparations on the motility of the rat and canine small intestine}; Beliaev OA et al.; The effect of combined microbial enzyme agents trizyme and triaze containing alkaline and neutral proteases, lipase, and amilase on the evacuation capacity of the small intestine of conscious rats and of the dog small intestine operated on by the Thiry-Vella method . Therapeutic doses of the enzymatic agents had no noticeable effect on the evacuation function of the intestine . The contraction of bands of the rat intestine induced by electrical stimulation depended on the concentration of the perfusate of the solution of the enzymatic agents . Low concentration of the agents caused no effect or weakly activated the contractions of the smooth intestinal muscles . Doses of the agents higher than the mean therapeutic doses caused decrease of the contraction amplitude of the intestinal bands by 30-40%. Anticancer Res, 1998 Sep-Oct, 18(5D), 3907 - 15 The search for a potent DNA vaccine against AIDS: the enhancement of immunogenicity by chemical and genetic adjuvants; Sasaki S et al.; DNA vaccination is a new way to generate antigen specific immune responses by inoculating plasmid DNA encoding microbial genes . We believe that the use of immunologic adjuvants together with DNA vaccines is a promising way to enhance and optimize DNA-derived immunity . Various chemical and genetic adjuvants have been explored in our recent study . Data from these studies suggests that adjuvants exert their immunomodulatory properties through several mechanisms such as lymphoid cells recruitment, cytokine induction, and the facilitation of DNA entry into cells . Furthermore, each adjuvant has unique immunomodulatory effects on cell-mediated and humoral immune responses induced by DNA vaccination to human immunodeficiency virus type 1 . To optimize the desirable immune response, the choice of adjuvant and decision of immunization route are important considerations . A similar approach may be useful potentiating anticancer immunotherapy as well. Proteins, 1998 Dec 1, 33(4), 518 - 34 Patterns of protein-fold usage in eight microbial genomes: a comprehensive structural census; Gerstein M; Eight microbial genomes are compared in terms of protein structure . Specifically, yeast, H . influenzae, M . genitalium, M . jannaschii, Synechocystis, M . pneumoniae, H . pylori, and E . coli are compared in terms of patterns of fold usage-whether a given fold occurs in a particular organism . Of the approximately 340 soluble protein folds currently in the structure databank (PDB), 240 occur in at least one of the eight genomes, and 30 are shared amongst all eight . The shared folds are depleted in allhelical structure and enriched in mixed helix-sheet structure compared to the folds in the PDB . The top-10 most common of the shared 30 are enriched in superfolds, uniting many non-homologous sequence families, and are especially similar in overall architecture-eight having helices packed onto a central sheet . They are also very different from the common folds in the PBD, highlighting databank biases . Folds can be ranked in terms of expression as well as genome duplication . In yeast the top-10 most highly expressed folds are considerably different from the most highly duplicated folds . A tree can be constructed grouping genomes in terms of their shared folds . This has a remarkably similar topology to more conventional classifications, based on very different measures of relatedness . Finally, folds of membrane proteins can be analyzed through transmembrane-helix (TM) prediction . All the genomes appear to have similar usage patterns for these folds, with the occurrence of a particular fold falling off rapidly with increasing numbers of TM-elements, according to a "Zipf-like" law . This implies there are no marked preferences for proteins with particular numbers of TM-helices (e.g . 7-TM) in microbial genomes. Ann Biol Clin (Paris), 1998 Nov-Dec, 56(6), 681 - 92 {Bartonellosis: I . Bartonella henselae}; Piemont Y et al.; The recent discovery of the bacterium Bartonella henselae was mainly due to the development of molecular biology techniques adapted to microbial diagnosis and to the description of new human diseases linked to Aids . About 10% of pet cats and 33% of stray cats harbour that bacterium in their blood . In immunocompetent patients, that bacterium is responsible for human cat scratch disease, characterized essentially by a localized lymph nodes enlargement in the vicinity of the entry site of the bacteria . This disease occurs more likely in pet cats less than 1-year-old and infested with fleas . The bacterium is transmitted to humans by scratches or bites; the role of fleas is possible, but is not yet documented . In 5 to 13% of cases, the cat scratch disease appears as more severe, including health impairment, hepatitis, Parinaud's oculo-glandular syndrome, neurological complications or stellate retinitis . In immunocompromised patients, B . henselae is responsible for various clinical presentations: bacillary angiomatosis, bacillary peliosis, recurrent or persistent bacteremia or endocarditis . Diagnosis of infections due to B . henselae can be performed by serological specific testing with sensitivity and specificity values ranging from 75 to 100% . Cultivation of the bacterium is fastidious, particularly in cases of cat scratch disease . The most efficient diagnostic test is the in vitro DNA amplification which has the drawback to require a lymph node sample . Antibiotics are usually inefficient for the treatment of cat scratch disease . By contrast, in immunocompromised patients, these infections are successfully treated for a more or less long time by macrolides or tetracyclines or rifampin. Gene, 1998 Oct 9, 221(1), 1 - 9 The Drosophila ebony gene is closely related to microbial peptide synthetases and shows specific cuticle and nervous system expression; Hovemann BT et al.; The previously detected ebony (e) locus (Caizzi et al., 1987) consists of a complex gene structure that is divided into seven exons . An open reading frame encoding the putative Ebony protein of 98.5 kDa exhibits homology to a family of peptide synthetases (Stachelhaus and Marahiel, 1995), in good correlation with the proposed function as beta-alanyl-dopamine synthetase . Multiple ebony transcripts are detected throughout development . P-factor mediated transformation of genomic DNA rescues the cuticle, electrophysiological and behavioural phenotypes . Fusion of the ebony reading frame with that of beta-galactosidase of E . coli reveals expression in cuticle and nervous system . Strong staining in the first and, to a lesser extent, in the second optic neuropile may reflect the pronounced visual defect observed in ebony mutants . In addition, weak central brain and thoracic ganglion expression is detected in flies . Conservation of a multidomain protein structure known from peptide synthetases should have functional implications on the putative reaction mechanism of peptide bond formation. Microb Ecol, 1999 Jan, 37(1), 70 - 77 The Impact of Oxygen Tension on Cell Density and Metabolic Diversity of Microbial Communities in Alkane Degrading Continuous-Flow Cultures; Berthe-Corti L et al.; Abstract The impact of the dissolved O2 tension (DOT) and the dilution rate on the metabolic diversity of an autochthonous hexadecane-degrading community in continuous-flow cultures containing hexadecane-coated intertidal sediment was determined in a set of experiments . The DOT was kept constant within each culture at values of 80% (168 micromol O2L-1) or 0.4% (0.84 micromol O2 L-1) . The dilution rate was increased from D = 0.012 h-1 to D = 0.06 h-1 . To determine the culture activity, we analyzed the hexadecane degradation rate, the protein production rate, and the oxygen consumption rate . The cell concentration of different metabolic groups was determined by colony forming units (CFU), and by most probable number (MPN) . The metabolic diversity was determined by the substrate utilization spectrum in Biolog GN microtiter plates . The substrate utilization pattern of the cultures decreased considerably as D increased . This effect was more pronounced at 0.4% of DOT than at 80% of DOT . The MPN and CFU revealed that as D increased, only minor changes occurred in the community structure . The hexadecane degradation rate, the protein production rate, and the oxygen consumption rate increased parallel to D independently of the DOT . This means that the biocenosis at 0.4% of DOT was different from the biocenosis at 80% of DOT, although the metabolic activity of the cultures was unaffected by a 200-factor difference in the oxygen tension and revealed a considerable buffer capacity with respect to changes in DOT. Microb Ecol, 1999 Jan, 37(1), 23 - 35 Influence of Three Contrasting Detrital Carbon Sources on Planktonic Bacterial Metabolism in a Mesotrophic Lake; Wehr JD et al.; Abstract Lakes receive organic carbon from a diversity of sources which vary in their contribution to planktonic microbial food webs . We conducted a mesocosm study to test the effects of three different detrital carbon sources (algae, aquatic macrophytes, terrestrial leaves) on several measures of microbial metabolism in a small meso-eutrophic lake (DOC approximately 5 mg/L) . Small DOC additions (DeltaC < 1 mg/L) affected bacterial numbers, growth, and pathways of carbon acquisition . Macrophyte and leaf detritus significantly increased TDP and color, but bacterial densities initially (+12 h) were unaffected . After 168 h, densities in systems amended with terrestrial detritus were 60% less than in controls, while production rates in mesocosms with macrophyte detritus were 4-fold greater . Detritus treatments resulted in greater per-cell production rates either through stable cell numbers and greater growth rates (macrophyte-C) or lower densities with stable production rates (terrestrial-C) . After only 12 h, rates of leucine aminopeptidase (LAPase) activity were 2.5x greater in macrophyte-C systems than in controls, but LAPase and beta-N-acetylglucosamindase activities in systems amended with terrestrial-C were only 50% of rates in controls . After 168 h, beta-xylosidase rates were significantly greater in communities with terrestrial and phytoplankton detritus . Microbial utilization of >20% of 102 carbon sources tested were affected by at least one detritus addition . Macrophyte-C had positive (6% of substrates) and negative (14%) effects on substrate use; terrestrial detritus had mainly positive effects . An ordination based on carbon-use profiles (+12 h) revealed a cluster of macrophyte-amended communities with greater use of psicose, lactulose, and succinamic acid; controls and algal-detritus systems were more effective in metabolizing two common sugars and cellobiose . After 168 h, communities receiving terrestrial detritus were most tightly clustered, exhibiting greater use of raffinose, pyroglutamic acid, and sebacic acid . Results suggest that pelagic bacterial communities respond to changes in organic carbon source rapidly and by different routes, including shifts in per-cell production rates and variations in degradation of a variety of compounds comprising the DOC pool. Microb Ecol, 1998 Nov, 36(3), 328 - 335 Vegetation Composition Determines Microbial Activities in a Boreal Forest Soil; Ohtonen R et al.; Abstract Forest soil ecology was studied in Fennoscandinavian dry Scots pine forests grazed by reindeer to varying extents (ungrazed, lichen-dominated-sites; grazed sites; and bryophyte-dominated sites) . We hypothesized that the productivity parameters of the site (i.e., tree growth and soil nutrient concentrations), the vegetation composition, and the microbial activities are directly correlated . Since the productivity of the lichen-dominated ecosystem is low, microbial activities are assumed to be naturally low . Grazing was expected to decrease both the amount of Scots pine fine roots and the soil microbial activities . Several variables on the characteristics of the soil microbial community, Scots pine fine roots, soil nutrients, and tree growth were studied in relation to vegetation composition by using non-metric multidimensional scaling (NMDS) . Basal respiration (Bas), metabolic quotient of the microbial community (qCO2), and pine fine root parameters increased toward the ungrazed, nutrient-poor, lichen-dominated sites, which were grouped at one end of the first axis in the NMDS ordination . Soil nutrient and tree growth parameters and thickness of the humus layer increased toward bryophyte-dominated sites, which were grouped at the other end of the first axis in the ordination . The grazed sites fell between them . These were characterized by lower Bas and qCO2 values and longer lag, compared to ungrazed lichen- or bryophyte-dominated sites, probably due to decreased carbon input and microclimatic change (the soil without lichen carpet is exposed to direct sunlight and wind) . Microbial biomass (Cmic), fungal biomass (ergosterol concentration), and the specific growth rate (microCO2) were not related to vegetation ordination . The high fine root production is the most plausible explanation for the high microbial activities at nutrient-poor, lichen-dominated sites, which produce qualitatively poor and slowly decomposing litter, as fine roots secrete considerable amounts of organic substances . At bryophyte-dominated sites, the higher soil nutrient concentrations and the higher production of easily decomposable substrates are likely to maintain the microbial activities. Microb Ecol, 1998 Nov, 36(3), 303 - 315 Microbial Diversity and Community Structure in Two Different Agricultural Soil Communities; Ovreas L et al.; Abstract In this study, two different agricultural soils were investigated: one organic soil and one sandy soil, from Stend (south of Bergen), Norway . The sandy soil was a field frequently tilled and subjected to crop rotations . The organic soil was permanent grazing land, infrequently tilled . Our objective was to compare the diversity of the cultivable bacteria with the diversity of the total bacterial population in soil . About 200 bacteria, randomly isolated by standard procedures, were investigated . The diversity of the cultivable bacteria was described at phenotypic, phylogenetic, and genetic levels by applying phenotypical testing (Biolog) and molecular methods, such as amplified rDNA restriction analysis (ARDRA); hybridization to oligonucleotide probes; and REP-PCR . The total bacterial diversity was determined by reassociation analysis of DNA isolated from the bacterial fraction of environmental samples, combined with ARDRA and DGGE analysis . The relationship between the diversity of cultivated bacteria and the total bacteria was elucidated . Organic soil exhibited a higher diversity for all analyses performed than the sandy soil . Analysis of cultivable bacteria resulted in different resolution levels and revealed a high biodiversity within the population of cultured isolates . The difference between the two agricultural soils was significantly higher when the total bacterial population was analyzed than when the cultivable population was . Thus, analysis of microbial diversity must ultimately embrace the entire microbial community DNA, rather than DNA from cultivable bacteria. Microb Ecol, 1998 Nov, 36(3), 251 - 258 Extracellular Enzyme Activities in Relation to Hydrodynamics in the Pomeranian Bight (Southern Baltic Sea); Nausch M et al.; Abstract The Pomeranian Bight in the southern Baltic Sea is characterized by a huge input of nutrients from the Oder river . This input shows seasonal variation . In winter, the nutrients are introduced in inorganic form . Particulate organic material is dominant in the growth season (summer/autumn) . From 1993 to 1996, extracellular enzyme activities (alkaline phosphatase, peptidase, alpha-, beta-glucosidase, and chitinase) were investigated to describe microbial reaction to the input of organic material and the modification of introduced material . The distribution patterns of extracellular enzyme activities in salinity gradients were studied, in response to the nutrient load . These activities were distinctly lower in winter than in summer and autumn . A close relationship to other biological parameters (Chl a, POC, PON) was observed during the growth season, but not in winter . Changes in peptidase and phosphatase activities between summer and autumn were also observed . The peptidase activity was 9 to 72 times higher in autumn than in summer . In contrast, the alkaline phosphatase activity was 5 to 30 times higher in summer than in autumn . The organic compound turnover rate/hydrolysis rate (To/Hr) ratio is a relative index which describes the coupling of enzymatic hydrolysis and utilization of monomers from investigated substrates (carbohydrates and proteins) . In summer, after dilution, the raised To/Hr quotients of glucose indicated limited importance for hydrolysis products in bacterial turnover . The increased demand for glucose resulted in a parallel decrease in monosaccharides . In autumn, the relationship between the turnover of glucose and amino acids and the supply of these substances by enzymatic degradation remained at the same level. Microb Ecol, 1998 Nov, 36(3), 239 - 250 Bacterioplankton Dynamics in the McMurdo Dry Valley Lakes, Antarctica: Production and Biomass Loss over Four Seasons; Takacs CD et al.; Abstract Research of the microbial ecology of McMurdo Dry Valley lakes has concentrated primarily on phototrophs; relatively little is known about the heterotrophic bacterioplankton . Bacteria represent a substantial proportion of water column biomass in these lakes, comprising 30 to 60% of total microplankton biomass . Bacterial production and cell numbers were measured 3 to 5 times, within four Antarctic seasons (October to January), in Lakes Fryxell, Hoare, and Bonney . The winter-spring transition (September to October) was included during one year . Lake Fryxell was the most productive, but variable, lake, followed by Lakes Bonney and Hoare . Bacterial production ranged from 0 to 0.009 microg C ml-1 d-1; bacterial populations ranged from 3.2 x 10(4) to 4.4 x 10(7) cells ml-1 . Bacterial production was always greatest just below the ice cover at the beginning of the season . A second maximum developed just above the chemocline of all the lakes, as the season progressed . Total bacterioplankton biomass in the lakes decreased as much as 88% between successive sampling dates in the summer, as evidenced by areal integration of bacterial populations; the largest decreases in biomass typically occurred in mid-December . A forward difference model of bacterial loss in the trophogenic zone and the entire water column of these lakes showed that loss rates in the summer reached 6.3 x 10(14) cells m-2 d-1 and 4.16 x 10(12) cells m-2 d-1, respectively . These results imply that bacteria may be a source of carbon to higher trophic levels in these lakes, through grazing. Can J Microbiol, 1998 Sep, 44(9), 886 - 95 Use of almond mesocarp for production of the entomopathogenic fungus Verticillium lecanii; Lopez-Llorca LV et al.; Almond mesocarp (AM) has been evaluated for production of Verticillium lecanii . Microbial flora of AM has been studied . After ground AM dilution plating, 5.3 x 10(5) +/- 2.6 x 10(4) fungal CFU.g-1 of dry AM were found . Common fungal saprophytes (Rhizopus sp . and Alternaria spp.) were found in more than 80% of the samples . Aspergillus sp . and yeasts were found less commonly . Rhizopus sp., Alternaria spp., and Aspergillus sp . inhibited growth of several V . lecanii; therefore, AM was treated with sterilization agents to eliminate endogenous mycoflora . Small samples (10 g) of AM saturated in distilled water treated with steam (120 degrees C and 100 kPa) were completely sterilized after 15 min . Ground AM incorporated on agar increased the biomass of V . lecanii compared with controls . This suggested AM as suitable substrate for the production of the fungus . In petri dishes, 9.7 x 10(7) +/- 2.9 x 10(7) conidia.g-1 of dry AM were produced after inoculating 10 conidia.g-1 of AM and incubating for 2 weeks . Viability of conidia produced was more than 90% . These conidia (5 x 10(4) conidia per larvae) caused Galleria mellonella mortality, calculated as median lethal time (LT50 5.3 +/- 1.6 days), that was significantly higher (F = 10.93; P < 0.05) than untreated controls (LT50 11.3 +/- 1.1 days) . Larger scale tests have to be optimized before mass production. J AOAC Int, 1998 Nov-Dec, 81(6), 1135 - 40 Identification of beta-lactam antibiotics in tissue samples containing unknown microbial inhibitors; Moats WA et al.; Antibiotic residues in animal tissues can be detected by various screening tests based on microbial inhibition . In the 7-plate assay used by the U.S . Department of Agriculture's Food Safety and Inspection Service (FSIS), penicillinase is incorporated into all but one plate to distinguish beta-lactam antibiotics from other types . However, beta-lactams such as cloxacillin and the cephalosporins are resistant to degradation by penicillinase . They may not be identified as beta-lactams by this procedure, and thus, they may be identified as unidentified microbial inhibitors (UMIs) . However, these penicillinase-resistant compounds can be degraded by other beta-lactamases . The present study describes an improved screening protocol to identify beta-lactam antibiotics classified as UMIs . A multiresidue liquid chromatographic procedure based on a method for determining beta-lactams in milk was also used to identify and quantitate residues . The 2 methods were tested with 24 tissue FSIS samples classified as containing UMIs . Of these, 3 contained penicillin G, including one at a violative level, and 5 contained a metabolite of ceftiofur . The others were negative for beta-lactam antibiotics. Int J Food Microbiol, 1998 Oct 20, 44(1-2), 49 - 68 Application of artificial neural networks as a non-linear modular modeling technique to describe bacterial growth in chilled food products; Geeraerd AH et al.; In many chilled, prepared food products, the effects of temperature, pH and %NaCl on microbial activity interact and this should be taken into account . A grey box model for prediction of microbial growth is developed . The time dependence is modeled by a Gompertz model-based, non-linear differential equation . The influence of temperature, pH and %NaCl reflected in the model parameters is described by using low-complexity, black box artificial neural networks (ANN's) . The use of this non-linear modeling technique makes it possible to describe more accurately interacting effects of environmental factors when compared with classical predictive microbiology models . When experimental results on the influence of other environmental factors become available, the ANN models can be extended simply by adding more neurons and/or layers. J Periodontol, 1998 Nov, 69(11), 1283 - 90 Scanning electron microscopic study of the effects of Er:YAG laser on root cementum; Fujii T et al.; Use of Er:YAG laser has been proposed for the removal of microbial deposits and calculus present on teeth affected by periodontal disease . However, the influence of Er:YAG laser irradiation on root surfaces has not yet been fully investigated . The aim of the present study was to evaluate the effects of Er:YAG laser irradiation on root cementum by scanning electron microscopy (SEM) . Specimens were obtained from extracted human periodontally-diseased teeth using a water-cooled high-speed bur . An Er:YAG laser beam was then applied at various powers ranging from 25 to 100 mJ/ pulse/sec . The laser irradiation was performed under water irrigation, with the tip held perpendicular to the root surface in the contact mode . Following laser exposure, specimens were fixed, dehydrated, and dried at critical-point in liquid CO2 . After mounting on SEM plates and sputter-coating with gold, the cementum surface was examined by SEM . Observations of the root surface showed a relatively flat surface in control specimens . In Er:YAG exposed specimens, the laser beam created a circular, notched-edge, crater-like defect on the root . The bottom of the lesion showed an irregular and sharp-pointed surface . Subsequently, the specimens were fractured with a sharp scalpel perpendicularly to the surface . SEM observations of these specimens showed a 15 microm layer of damaged tissue within the laser-irradiated cementum . The tissue presented an amorphous appearance and the Sharpey's and matrix fiber bundles were not clearly distinguishable . These observations indicate that cementum tissue could be damaged by Er:YAG laser irradiation. Med Hypotheses, 1998 Nov, 51(5), 421 - 7 Microbiology of the intestinal lymph follicle: a clue to elucidate causative microbial agent(s) in Crohn's disease; Chiba M et al.; It has been suggested that microbial agent(s) are involved in the onset of Crohn's disease . None of the candidates, however, has been unequivocally demonstrated to be a causative agent . The macroscopically earliest lesion takes place in the lymph follicle, irrespective of the initial attack or relapse in Crohn's disease . Human leucocyte antigen-DR (HLA-DR) antigens are expressed on the epithelium around the lymph follicle even in areas endoscopically uninvolved in Crohn's disease . These observations make the lymph follicle critical in the onset of Crohn's disease . The lymph follicle is a port of entry of a variety of microbial agent(s), leading to the speculation that microbial agent(s) exist in the lymph follicle . Polymerase chain reaction (PCR) using universal primers designed from conserved regions of bacterial ribosomal RNA or techniques such as representational difference analysis, may well identify microbial agent(s) in the lymph follicle that are specific to Crohn's disease . The existence of bacteria in the lymph follicle is here indicated by preliminary studies. Toxicol Sci, 1998 Oct, 45(2), 195 - 203 Allergic responses to the biopesticide Metarhizium anisopliae in Balb/c mice; Ward MD et al.; Metarhizium anisopliae is used as a microbial pesticide to control cockroaches and other insects . M . anisopliae has demonstrated neither infectivity nor toxicity in mammals . However, allergenicity has not been assessed . M . anisopliae is a prototype for other organisms released into the environment for pesticide or other beneficial applications . Hence this study is part of an effort to develop methods for screening such organisms for allergenic potential . Soluble factors from fungal components were combined in equal protein amounts to form a crude fungal antigen (MACA) . Balb/c mice were intratracheally (IT) challenged with 25 micrograms fungal antigen 13 days post intraperitoneal sensitization with the fungal antigen in alhydrogel adjuvant . Additionally, mice were sensitized with adjuvant alone or chitin media in adjuvant as experimental controls . Serum and bronchoalveolar lavage fluid (BALF) were harvested prior to challenge and at 1 and 7 days post IT challenge (DPIT) . These mice exhibited immune and pulmonary inflammatory responses to MACA characteristic of allergy . Total serum IgE for antigen-sensitized animals increased 7.6- and 14.7-fold over that for chitin media and adjuvant controls, respectively, at 7 DPIT . Less striking increases were seen at 24 DPIT and prior to challenge . BALF IL-4 was dramatically elevated only in MACA-sensitized and challenged mice and only at 1 DPIT . Additionally, there was a dose-dependent increase in BALF eosinophils from MACA-sensitized mice at both 1 and 7 DPIT . While lymphocyte counts were increased for all treatment groups at 1 DPIT, by 7 DPIT lymphocyte counts for MACA-sensitized mice only were significantly elevated compared to controls . Pulmonary inflammation, edema, and cell damage were apparent at 1 DPIT (25 micrograms MACA), as indicated by a neutrophilic influx and elevated levels of total protein and LDH, in both sensitized and control groups . These effects were significantly decreased, but not eliminated by reduction of the challenge dose to either 10 or 5 micrograms MACA . While BALF IL-4 was also reduced at the lower challenge doses, eosinophilia and total IgE were unchanged . The data suggest that the crude fungal extract MACA contains one or more potent allergens and that total IgE may be useful in the identification of the allergen(s). Kansenshogaku Zasshi, 1998 Oct, 72(10), 1056 - 63 {Occurrence of free-living amoebae and Legionella in whirlpool bathes}; Kuroki T et al.; Occurrence of both Legionella species and free-living amoebae were surveyed in whirlpool bathes installed in 11 private houses, 8 public bathes and 13 spas . Free-living amoebae that are known to be the hosts of Legionella were isolated from 24 out of 32 water samples (75%) . Single Legionella species, L . pneumophila, with different serogroups (SG) predominantly SG3 (18.3%), SG5 (23.7%) and SG6 (15.8%), were isolated from 21 damples, ranging from 10(1) to 10(4) CFU/100 ml . Further studies were conducted for 10 consecutive weeks to monitor the occurrence of both free-living amoebae and Legionella in the whirlpool bathes of 4 private houses . Free-living amoebae, such as Hartmannella and Vexillifera, and L . pneumophila SG1, SG3, SG4, SG5 and SG6 were consistently isolated from all the water samples throughout the monitoring periods . Bath basins in which Hartmennella and Vannella were isolated tended to harbor large number of Legionella . Management practices such as frequent washing filter elements and/or frequent addition of tap water to bath basins is highly recommended to reduce microbial contaminants. Public Health Rep, 1998 Sep-Oct, 113(5), 398 - 409 The indoor air we breathe; Oliver LC et al.; Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis . Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue . Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust . Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance . A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades . Organizational issues and psychological variables often contribute to the problem and hinder its resolution . This article describes the health problems related to poor indoor air quality and offers solutions. J Colloid Interface Sci, 1998 Sep 1, 205(1), 185 - 90 Electrophoretic Mobilities of Protein-Coated Hexadecane Droplets at Different pH; van der Mei HC et al.; Electrophoretic mobilities of hexadecane droplets in 10 mM potassium phosphate solutions (pH between 3.0 and 7.0) and in phosphate buffered saline (pH 7.0) were measured during adsorption of bovine (BSA) and human (HSA) serum albumin, immunoglobulin G (IgG), and fibrinogen (Fg) from single-protein solutions as well as during protein adsorption from binary HSA/IgG and HSA/Fg mixtures and from diluted plasma . Electrophoretic mobilities became less negative upon adsorption of proteins within 1.5 min after the initiation of adsorption . Only for IgG, was a time-dependent change of the electrophoretic mobilities of the protein-hexadecane complex observed . In phosphate buffered saline, less negative electrophoretic mobilities were measured than in the potassium phosphate solution . Iso-electric points of the protein-hexadecane complexes in 10 mM potassium phosphate were located at pH 5.0 for albumin, at pH 5.5 for Fg, and at pH 6.6 for IgG, i.e., about the iso-electric points of the pure unadsorbed proteins . This confirms that the net charge addition upon protein adsorption, which is positive below the iso-electric point of the proteins, at low protein concentrations determines the effects on the final electrophoretic mobilities of the protein-hexadecane complexes . As a name for the methodology applied, we propose PATH (protein adsorption to hydrocarbons), in analogy to the well-known MATH (microbial adhesion to hydrocarbons) method . The major advantage of PATH is that it represents an in situ method to study protein adsorption, without artifactual rinsing steps, while furthermore the hydrocarbon phase can be replaced by organic solvents to study the role of acid-base interactions in protein adsorption . In combination with drop-shape analysis techniques, PATH also enables us to determine in situ effects of protein adsorption on interfacial tensions . Nucleic Acids Res, 1999 Jan 1, 27(1), 171 - 3 A new version of the RDP (Ribosomal Database Project); Maidak BL et al.; The Ribosomal Database Project (RDP-II), previously described by Maidak et al . { Nucleic Acids Res . (1997), 25, 109-111}, is now hosted by the Center for Microbial Ecology at Michigan State University . RDP-II is a curated database that offers ribosomal RNA (rRNA) nucleotide sequence data in aligned and unaligned forms, analysis services, and associated computer programs . During the past two years, data alignments have been updated and now include >9700 small subunit rRNA sequences . The recent development of an ObjectStore database will provide more rapid updating of data, better data accuracy and increased user access . RDP-II includes phylogenetically ordered alignments of rRNA sequences, derived phylogenetic trees, rRNA secondary structure diagrams, and various software programs for handling, analyzing and displaying alignments and trees . The data are available via anonymous ftp (ftp.cme.msu . edu) and WWW . The WWW server provides ribosomal probe checking, approximate phylogenetic placement of user-submitted sequences, screening for possible chimeric rRNA sequences, automated alignment, and a suggested placement of an unknown sequence on an existing phylogenetic tree . Additional utilities also exist at RDP-II, including distance matrix, T-RFLP, and a Java-based viewer of the phylogenetic trees that can be used to create subtrees. Nucleic Acids Res, 1999 Jan 1, 27(1), 263 - 7 Recent improvements of the ProDom database of protein domain families; Corpet F et al.; The ProDom database contains protein domain families generated from the SWISS-PROT database by automated sequence comparisons . The current version was built with a new improved procedure based on recursive PSI-BLAST homology searches . ProDom can be searched on the World Wide Web to study domain arrangements within either known families or new proteins, with the help of a user-friendly graphical interface . Recent improvements to the ProDom server include: ProDom queries under the SRS Sequence Retrieval System; links to the PredictProtein server; phylogenetic trees and condensed multiple alignments for a better representation of large domain families, with zooming in and out capabilities . In addition, a similar server was set up to display the outcome of whole genome domain analysis as applied to 17 completed microbial genomes . Curr Eye Res, 1998 Nov, 17(11), 1082 - 6 Defensin gene expression in the cornea; Gottsch JD et al.; PURPOSE: To determine whether defensin genes are expressed in human corneas and bovine corneal keratocytes . METHODS: In situ hybridization and immunohistochemistry were used to localize defensin mRNA and protein in normal and diseased human corneas . Cultured bovine keratocytes were stimulated with IL-1alpha or TNFalpha to determine whether defensin mRNA production occurred . Reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify defensin cDNA from cytokine-induced keratocytes, and Southern blots were used to verify the specificity of RT-PCR amplification products . RESULTS: Defensin mRNA and protein were not detected in normal human corneal stroma, but were readily detectable in the corneal stroma in cases of rejected transplants and postinfectious keratitis . IL-1alpha was a potent inducer of defensin gene expression in keratocytes, which began 12 h after challenge and peaked at 18 to 24 h . TNFalpha weakly induced defensin mRNA in keratocytes at about 18 h . Southern blots of the RT-PCR products probed with an oligonucleotide complementary to internal sequences of defensin demonstrated the appropriately sized products (198 bp) specific for defensin . CONCLUSIONS: This report demonstrates the presence of defensin in the human cornea and the capacity of corneal keratocytes to produce defensin mRNA in response to IL-1alpha and TNFalpha . Release of defensins by keratocytes in response to cytokines elaborated in corneal inflammation may contribute to the host defense response in microbial keratitis. Transplantation, 1998 Nov 27, 66(10), 1340 - 7 Differential immune response to influenza and pneumococcal vaccination in immunosuppressed patients after heart transplantation; Dengler TJ et al.; INTRODUCTION: Patients after solid organ transplantation are at an increased risk for microbial infections . Due to therapeutic immunosuppression, the response to active immunizations may be reduced . The serological efficacy of pneumococcal and influenza vaccination was studied in heart transplant recipients . PATIENTS AND METHODS: Sixteen patients over 1 year after heart transplantation and control patients were immunized with a 23-valent pneumococcal vaccine and a triple-split influenza vaccine . Pre- and postvaccinal antibody titers were serologically determined, including quantitation of specific antibodies against nine pneumococcal serotypes . RESULTS: Both vaccines were well tolerated without systemic reactions or infectious complications . Median postvaccinal pneumococcal antibody titers in the transplant patients were comparable to controls (5513 U/ml, range: 694-41007, vs . 5490 U/ml, range: 1088-38042; P=NS); vaccination was successful in 23/23 (100%) of controls and in 15/16 (94% plus 1 borderline positive case) of the transplant recipients . Specific antibody titers were similar for eight of nine serotypes; only the immune response against serotype 3 was reduced after transplantation . The efficacy of influenza vaccination was significantly impaired in transplant patients against all three virus strains (62% vs . 97%, P<0.01/50% vs . 94%, P<0.001/37% vs . 80%, P<0.01), but 9/16 (56%) of patients still showed a sufficient immune response to two out of three virus strains . No clinical or demographic predictors of successful vaccination could be established . CONCLUSIONS: Pneumococcal vaccination under cyclosporine-based immunosuppression after heart transplantation is safe and equally effective as in healthy controls . In contrast, the immune response to influenza vaccination is significantly reduced, although not completely abolished . This differential response might be accounted for by T cell-independent antibody production against polysaccharide antigens contained in the pneumococcal vaccine. PDA J Pharm Sci Technol, 1998 Sep-Oct, 52(5), 215 - 27 Validation of a high voltage leak detector for use with pharmaceutical blow-fill-seal containers--a practical approach; Moll F et al.; Proposed requirements for pharmaceutical package integrity testing outlined in the EU Guide for Sterile Medicinal Products may make it necessary to evaluate and validate alternate ways to perform 100% leak inspection . One such method is high voltage leak detection (HVLD) . Even though HVLD has been used for glass ampoules and vials for years, qualification and validation strategies are not well established . In this article, we describe and discuss our practical approach to validation and the protocols used to qualify and validate a high voltage leak detector for use with blow-fill-seal containers . For this work, we used laser drilled pinholes as a model for pinholes produced during manufacturing and defined a "window diagram." This diagram allowed us to plot the parameters of influence and the settings of the HVLD in an easy to visualize pictorial display . In the validation step, we initially determined the most sensitive standard integrity test for our product and container design from the available choices, the vacuum chamber, dye bath and microbial challenge visual inspection tests . In the next phase of our work, the HVLD was crossed-validated against the most sensitive of these tests, the dye bath visual inspection test . This was accomplished with a large number of containers mixed with deliberately defective ampoules . Our conclusion from this work is that the HVLD is an appropriate and feasible integrity test for 100% inspection of blow-fill-seal containers. Acta Otorhinolaryngol Ital, 1998 Apr, 18(2), 107 - 10 {Bacterial and fungal colonization in indwelling total laryngectomy phonatory prostheses: identification of microbial agents, treatment protocol and prevention}; Nazionale G et al.; Today, after the erygmophonic voice, the application of phonatory prostheses is the rehabilitation strategy of choice in patients who had undergone laryngectomy . This is because the surgical procedure is simple and because they are highly successful . The main cause of complications is infection or biofouling . The present study examined the results of cultures taken from phonatory prostheses in 15 laryngectomy patients . The dominating strains of the bacteria and fungi were tested to determine their sensitivity to various pharmacological treatments . By working up and applying a preventive and treatment protocol to reduce prosthetic infections, the average duration of these devices, and thus their functionality, has been increased by approximately 50% bringing it from 6 to 9 months. Circulation, 1998 Dec 8, 98(23), 2534 - 7 Enterovirus infections as a possible risk factor for myocardial infarction; Roivainen M et al.; BACKGROUND: An increasing body of evidence suggests that, in addition to the well-known classic risk factors, some microbial infections may be associated with the development of atherosclerosis and myocardial infarction (MI) . The aim of our study was to evaluate the possible role of enteroviral infections in the pathogenesis of MI . METHODS AND RESULTS: Stored sera, collected in Eastern Finland in 1977, from a set of 12 155 randomly selected men and women aged 25 to 64 years were used in prospective, nested case-control study . The study sample comprised 183 men and 81 women with MI and matched controls . The sera were tested for IgG antibodies to a newly identified enterovirus-common (EVC) antigen, to heat-denatured coxsackievirus B5 (CBV-5), and to adenovirus hexon protein . Raw data from enzyme immunoassays were converted to relative units before analysis . In univariate analysis, EVC antibodies were significantly associated with the risk of MI in men (P=0.009) but not in women . Men with MI had a significantly higher mean level of EVC antibodies than matched controls (P=0.014) . High antibody levels to EVC were associated with an increased risk of MI in men aged 25 to 49 years (relative risk {RR} 4.34, P<0.001) but not in older men (>50 years of age) . Women with MI also showed a trend toward higher antibody levels than control women, but the difference was not statistically significant . Antibody levels to whole CBV-5 or adenovirus hexon protein appeared to be no different among case patients versus control subjects . CONCLUSIONS: If we assume that a high level of EVC antibodies reflects a history of relatively frequent enterovirus infections, the present observation might suggest that enterovirus infections increase the risk of MI at least in middle-aged men . Further studies are needed to understand possible clinical significance of this observation. Biochemistry, 1998 Nov 10, 37(45), 15865 - 76 Characterization of pKa values and titration shifts in the cytotoxic ribonuclease alpha-sarcin by NMR . Relationship between electrostatic interactions, structure, and catalytic function; Perez-Canadillas JM et al.; The electrostatic behavior of titrating groups in alpha-sarcin was investigated using 1H NMR spectroscopy . A total of 209 chemical shift titration curves corresponding to different protons in the molecule were determined over the pH range of 3.0-8.5 . Nonlinear least-squares fits of the data to simple relationships derived from the Henderson-Hasselbalch equation led to the unambiguous determination of pKa values for all glutamic acid and histidine residues, as well as for the C-terminal carboxylate and most of the aspartic acids in the free enzyme . The ionization constants of catalytically relevant histidines, His50 and His137, and glutamic acid, Glu96, in the alpha-sarcin-2'-GMP complex were also determined . The pKa values of 15 ionizable groups (C-carboxylate, six aspartic acids, four glutamic acids, and four histidines) were found to be close to their normal values . On the other hand, a number of side chain groups, including those in the active center, showed pKa values far from their intrinsic values . Thus, the pKa values for active site residues His50, Glu96, and His137 were 7.7, 5.2, and 5.8 in the free enzyme and 7.6, approximately 4.8, and 6.8 in the alpha-sarcin-2'-GMP complex, respectively . The pKa values and the activity profile against ApA, as a function of pH, are in agreement with the proposed enzymatic mechanism (in common with RNase T1 and the family of the microbial ribonucleases), in which Glu96 and His137 act as a general base and general acid, respectively . In almost all microbial ribonucleases, a Phe-His interaction is present, which affects the pKa of one of the His residues at the active site (His137) . The absence of this interaction in alpha-sarcin would explain the lower pKa value of this His residue, and provides an explanation for the decreased RNase activity of this protein as compared to those of other microbial ribonucleases. Biosens Bioelectron, 1998 Nov 1, 13(10), 1083 - 90 Determination of BOD-values of starch-containing waste water by a BOD-biosensor; Reiss M et al.; The control of waste water plants is difficult or even impossible using the classical determination method for biological oxygen demand (BOD), because of its high time consumption of five days . A determination within some minutes is possible by microbial BOD-sensors . However, high molecular weight substances cannot be detected, a problem which can be overcome by the use of additional enzymes . For the application in a flow-through system to analyse starch containing waste water, alpha-amylase and amyloglucosidase were immobilized by adsorption to polystyrene or polypropylene carriers followed by crosslinking . Furthermore, covalent coupling to different nylon carriers, derivatives of chitin, silanized glass beads and silanized beads of foamed glass was tried . Chitin and Lewatit were the best suited carriers for the immobilization of alpha-amylase and amyloglucosidase . Two glass columns were filled with the immobilized enzymes and inserted into a commercial BOD-sensor containing the yeast Trichosporon cutaneum as biological component . The system was stable for more than two months under storage and one month under working conditions . A comparison of different starch types resulted in a hydrolysis of more than 80% in case of potato starch whereas grain starch was hydrolized only for 40-50% . Sensor-determined BOD-values of waste water with potato starch were nearly identical with BOD5-values resulting from the classical method. Eur J Biochem, 1998 Nov 1, 257(3), 615 - 21 Molecular cloning of cDNA for pro-phenol-oxidase-activating factor I, a serine protease is induced by lipopolysaccharide or 1,3-beta-glucan in coleopteran insect, Holotrichia diomphalia larvae; Lee SY et al.; Previously, we identified two pro-phenol oxidase-activating factors, named PPAF-I and PPAF-II, directly involved in the activation of the purified pro-phenol oxidase (pro-PO) from the hemolymph of the coleopteran, Holotrichia diomphalia larvae {Lee, S . Y., Kwon, T . H., Hyun, J . H., Choi, J . S., Kawabata, S . I., Iwanga, S, & Lee, B . L . (1998) Eur . J . Biochem . 254, 90-97} . Here, we report molecular cloning of cDNA for PPAF-I . Based on the sequence of the cloned cDNA, the PPAF-I gene appears to encode a member of serine protease zymogen consisting of 365 amino acid residues with a molecular mass of 40193 Da . The 109 amino acid residues preceding the amino-terminus Ile residue of the mature protein seem to constitute a prepro-sequence . The mature protein is a serine protease composed of 256 amino acids with a calculated molecular mass of 28009 Da . The overall structure is highly similar to that of Drosophila easter serine protease (42.9% identity), an essential serine protease zymogen for pattern formation in normal embryonic development . The locations of disulfide linkages in the pro-segment of PPAF-I were similar to those of Tachypleus proclotting enzyme and the mammalian neutrophil-derived defensin . Furthermore, {3H}diisopropylphosphate (iPr2P)-labeled PPAF-I was specifically produced from the crude preparation of PPAF-I zymogen by incubation with lipopolysaccharide or 1,3-beta-glucan, whereas {3H}iPr2P-labeled PPAF-I was not produced under the same conditions in the absence of these microbial polysaccharides . These results indicate that the pro-PO-activation system in H . diomphalia larvae may proceed with the activation of PPAF-I zymogen by microbial polysaccharides. Biosens Bioelectron, 1998 Oct 15, 13(9), 945 - 52 Microbial O2- and H2O2-electrode sensors for alcohol assays based on the use of permeabilized mutant yeast cells as the sensitive bioelements; Gonchar MV et al.; Two types of alcohol-specific microbial/electrochemical biosensors have been developed using specially constructed mutant cells of the methylotrophic yeast Hansenula polymorpha . The cells were immobilized in a calcium alginate gel, and placed between two membranes on the surface of oxygen or hydrogen peroxide-electrodes . The O2 electrode based biosensor contained mutant cells with strongly elevated alcohol oxidase activity . The peroxide electrode based biosensor consisted of catalase-defective mutant cells which produce hydrogen peroxide in the presence of alcohol . Both types of mutant cells were used in permeabilized form in order to release some components of the cellular respiration system, thus increasing the selectivity of the cellular respiration response to alcohol (cell/O2-biosensor) Permeabilization also increased sensitivity of the signal and shortened the response time (cell/H2O2-biosensor) . Cell/O2 biosensors were linear up to 1.2 mM for ethanol and 0.35 mM for methanol, cell/H2O2 biosensors were linear up to 4.0 mM for ethanol, and 1.2 mM for methanol . Results were reproducible, sample pretreatment was not required, and the sensors exhibited good operational and storage stability . The use of sucrose, dulcitol or inositol during the preparation of the sensors resulted in increased stability of cells during their liophilization and storage in the dried state . Both biosensors had similar selectivity towards alcohols in the order of methanol (100%), ethanol (21%), and formaldehyde (12%) . No signal was observed with glucose or glycerol as substrates. Mediators Inflamm, 1998, 7(2), 69 - 72 Serum levels of pro- and anti-inflammatory cytokines in non-pregnant women, during pregnancy, labour and abortion; Vassiliadis S et al.; Disturbance of the cytokine equilibrium has been accused for many pathological disorders . Microbial infections, autoimmune diseases, graft rejection have been correlated to over- or under-production of specific cytokines which are produced as responder molecules to the various immune stimuli . The sole naturally occurring immune reaction in the organism is developed during the gestational period where, despite the presence of a semi-allogeneic graft, maternal immunoreactivity is driven to support fetal growth . The successful embryo development has been attributed to the important intervention of cytokines where some have been characterized as indispensable and others deleterious to fetal growth . However, the physiological levels of many factors during the gestational process have not been determined . Thus, in the present study we have measured and established the values of IL-1alpha, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, GM-CSF, TNF-alpha and IFN-gamma during all phases of human pregnancy (first, second and third trimester of pregnancy, labour, abortions of the first trimester) as well as in the non-pregnant control state . This is an attempt to assess serum protein concentrations and present the physiological levels of these cytokines at certain time intervals providing thus a diagnostic advantage in pregnancy cases where the mother cannot immunologically support the fetus . Exploitation of this knowledge and further research may be useful for therapeutic interventions in the future. CMAJ, 1998 Nov 3, 159(9), 1129 - 36 Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria; Khachatourians GG; Microbial Resistance to antibiotics is on the rise, in part because of inappropriate use of antibiotics in human medicine but also because of practices in the agricultural industry . Intensive animal production involves giving livestock animals large quantities of antibiotics to promote growth and prevent infection . These uses promote the selection of antibiotic resistance in bacterial populations . The resistant bacteria from agricultural environments may be transmitted to humans, in whom they cause disease that cannot be treated by conventional antibiotics . The author reviews trends in antibiotic use in animal husbandry and agriculture in general . The development of resistance is described, along with the genetic mechanisms that create resistance and facilitate its spread among bacterial species . Particular aspects of resistance in bacterial species common to both the human population and the agrifood industry are emphasized . Control measures that might reverse the current trends are highlighted. Appl Environ Microbiol, 1998 Dec, 64(12), 4983 - 9 Novel euryarchaeotal lineages detected on rice roots and in the anoxic bulk soil of flooded rice microcosms Gro kopf R, Stubner S, Liesack W. Because excised, washed roots of rice (Oryza sativa) immediately produce CH4 when they are incubated under anoxic conditions (P . Frenzel and U . Bosse, FEMS Microbiol . Ecol . 21:25-36, 1996), we employed a culture-independent molecular approach to identify the methanogenic microbial community present on roots of rice plants . Archaeal small-subunit rRNA-encoding genes were amplified directly from total root DNA by PCR and then cloned . Thirty-two archaeal rice root (ARR) gene clones were randomly selected, and the amplified primary structures of ca . 750 nucleotide sequence positions were compared . Only 10 of the environmental sequences were affiliated with known methanogens; 5 were affiliated with Methanosarcina spp., and 5 were affiliated with Methanobacterium spp . The remaining 22 ARR gene clones formed four distinct lineages (rice clusters I through IV) which were not closely related to any known cultured member of the Archaea . Rice clusters I and II formed distinct clades within the phylogenetic radiation of the orders "Methanosarcinales" and Methanomicrobiales . Rice cluster I was novel, and rice cluster II was closely affiliated with environmental sequences obtained from bog peat in northern England . Rice cluster III occurred on the same branch as Thermoplasma acidophilum and marine group II but was only distantly related to these taxa . Rice cluster IV was a deep-branching crenarchaeotal assemblage that was closely related to clone pGrfC26, an environmental sequence recovered from a temperate marsh environment . The use of a domain-specific oligonucleotide probe in a fluorescent in situ hybridization analysis revealed that viable members of the Archaea were present on the surfaces of rice roots . In addition, we describe a novel euryarchaeotal main line of descent, designated rice cluster V, which was detected in anoxic rice paddy soil . These results indicate that there is an astonishing richness of archaeal diversity present on rice roots and in the surrounding paddy soil. Appl Environ Microbiol, 1998 Dec, 64(12), 4950 - 7 Analysis of the dynamics of bacterial communities in the rhizosphere of the chrysanthemum via denaturing gradient gel electrophoresis and substrate utilization patterns Duineveld BM, Rosado AS, van Elsas JD, van Veen JA. In order to gain a better understanding of the spatial and temporal dynamics of bacterial communities of the rhizosphere of the chrysanthemum, two complementary methods were used: a molecular bacterial community profiling method, i.e., 16S rRNA gene-based PCR followed by denaturing gradient gel electrophoresis (DGGE), and an agar plate method in which 11 sole-carbon-source utilization tests were used . The DGGE patterns showed that the bacterial communities as determined from direct rhizosphere DNA extracts were largely stable along developing roots of the chrysanthemum, with very little change over time or between root parts of different ages . The patterns were also similar to those produced with DNA extracts obtained from bulk soil samples . The DGGE patterns obtained by using microbial colonies from dilution plates as the source of target DNA were different from those found with the direct DNA extracts . Moreover, these patterns showed differences among plant replicates but also among replicate plates . Results obtained with the sole-carbon-source utilization tests indicated that the metabolic profile of the bacterial communities in the rhizosphere of the root tip did not change substantially during plant growth . This suggests selective development of specific bacterial populations by the presence of a root tip . On the other hand, the metabolic profile of bacterial communities in the rhizosphere of the root base changed during plant growth . With eight sole-carbon-source utilization tests, a significant effect of the development stage of the plant on the number of bacteria which were able to grow on these carbon sources was observed. Poult Sci, 1998 Nov, 77(11), 1671 - 7 Stability of porcine and microbial lipases to conditions that approximate the small intestine of young birds; Kermanshahi H et al.; In vitro experiments were conducted to study the stability of lipase activities from bacterial, fungal, and animal sources under conditions that approximate the small intestine . In the first experiment, the effects of preincubation with trypsin (500, 1,000, and 2,000 U/mL), chymotrypsin (200, 400, and 800 U/mL), and trypsin plus chymotrypsin (TC; 2,000 U/mL trypsin + 800 U/inL chymotrypsin) for 30 min at 40 C, on lipase activities from sources of Pseudomonas spp . (PL1, PL2), Chromobacterium viscosum (CVL), and Aspergillus niger (ANL) were determined . None of the enzymes were inhibited by trypsin . The chymotrypsin decreased the activity of all of the lipases . The TC had no additional negative effect on the activities of PL1 and PL2; however, ANL and CVL activities were further decreased relative to the chymotrypsin only treatment . In the second study, the effects of Na taurodeoxycholate (0.1 to 16 mM) on the activities of PL1, PL2, CVL, ANL, and crude porcine lipase (CPL) at 23 and 40 C were evaluated . At 23 C, in order of potency, Na taurodeoxycholate inhibited the activities of ANL, CPL, and CVL . At this temperature, Na taurodeoxycholate did not inhibit PL1 and PL2 . An increase in the temperature to 40 C increased the activity of all of the enzymes tested . At 40 C, Na taurodeoxycholate had similar effects on lipase activities; however, higher Na taurodeoxycholate levels were required to inhibit ANL activity, and only a partial inhibition of CPL occurred . At 23 C, porcine colipase restored the activity of CPL but had no effect on ANL and CVL in the presence of inhibitory levels of Na taurodeoxycholate . At 40 C, porcine colipase had no effect on Na taurodeoxycholate inhibition of lipase activity . The results of this study indicate that PL is more stable than CVL and ANL, and that colipase addition has no beneficial effects on microbial lipase activities under conditions that approximate the avian small intestine. Poult Sci, 1998 Nov, 77(11), 1665 - 70 Stability of porcine and microbial lipases to conditions that approximate the proventriculus of young birds; Kermanshahi H et al.; In vitro experiments were conducted to characterize the activity and the stability of lipase from animal (crude porcine, CPL; lyophilized porcine, LPL), fungal (Rhizopus arrhizus, RAL; Aspergillus niger, ANL), and bacterial (two Pseudomonas spp., PL1, PL2; and Chromobacterium viscosum, CVL) sources when exposed to conditions associated with the glandular stomach . Activity was measured at pH 3 to 8, 40 C and then monitored in response to temperature (40 C), time of exposure (0 and 30 min), pH (3 and 7), and pepsin level (5, 50, and 500 U/mL) . All lipases except ANL and CVL had maximum activity at pH 7 to 8 . The optimal pH for ANL and CVL were 5 and 6 to 8, respectively . Exposure of lipases to 40 C and pH 7 for 30 min reduced the activity of all lipases except ANL . In contrast, 40 C increased ANL activity 2.5-fold . Although activity of all lipases was reduced by exposure to pH 3, it was nearly eliminated for CPL and LPL . Pepsin concentration had only minor effects on lipase activity and then only at high concentration . The results demonstrate that bacterial lipases (PL1, PL2, and CVL) and ANL are more stable under conditions that approximate the glandular stomach and may explain why dietary porcine lipase has been ineffective in preventing fat malabsorption in previous in vivo studies. Eur Cytokine Netw, 1998 Sep, 9(3 Suppl), 65 - 8 Ignition of the type 1 response to intracellular infection by dendritic cell-derived interleukin-12; Sher A et al.; Host resistance to many intracellular pathogens is dependent on the induction of host IFN-gamma . This response in turn is triggered by the critical initiation cytokine, IL-12 . Activated macrophages provide a major source of IL-12 during infection yet are unlikely to be the initial cell to produce the cytokine because of their need for IFN-gamma priming and/or other co-stimulatory signals . We have utilized an in vivo approach to identify the primary IL-12 producing cells which respond to the intracellular protozoan Toxoplasma gondii . Our results indicate that in spleen interdigitating dendritic cells (IDC) but not macrophages rapidly synthesize IL-12 after injection of parasite products or live tachyzoites . This response is both IFN-gamma and T lymphocyte independent . The same microbial stimulus results in the migration of IDC precursors into T cell areas and the upregulation of co-stimulatory cell-surface molecules . We postulate that these early dendritic cell activation events represent the "ignition switch" for the subsequent Type 1 cytokine response which leads to control of infection. Eur Cytokine Netw, 1998 Sep, 9(3 Suppl), 54 - 64 Positive and negative regulation of interleukin-12 gene expression; Ma X et al.; Interleukin-12 (IL-12) is a pivotal cytokine representing the link between the cellular and humoral branches of an effective host immune defense apparatus . IL-12 is a heterodimer produced by phagocytic, B, dendritic, and possibly other accessory cells in both innate and adaptive immune responses . It is a key factor in the induction of T cell-dependent and independent activation of macrophages, generation of T helper type 1 (Th1) and cytotoxic T cells, suppression of IgG1 and IgE production, induction of organ-specific autoimmunity, and resistance to bacterial and parasitic infections {1} . IL-12 has a powerful anti-tumor and anti-metastatic activity against many murine tumors {2-5} as well as human tumors {6-17} . The genes encoding the two heterologous chains of IL-12, p40 and p35 are located on different human chromosomes . Together, p40 and p35 form the biologically active IL-12 . Their expressions are highly coordinated during an effective immune response . However, under some pathological conditions, IL-12 is under- or overexpressed, resulting either in a lack of resistance to microbial infection and to uncontrolled tumor growth, or in destructive inflammation, respectively . A transient or irreversible dysregulation of IL-12 production may reflect a pathogen/tumor cell-induced disruption in the highly coordinated expression of p40 and p35 . The understanding of the molecular mechanisms governing the expression of IL-12 p40 and p35 genes in the context of interactions between pathogens and the immune system is essential in efforts aimed at designing therapeutic strategies to treat infectious and malignant diseases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1998 Nov, 86(5), 578 - 81 The effect of periradicular endodontic pathosis on the apical region of adjacent implants; Shaffer MD et al.; Implants have become standard for dentate individuals . A potential problem to consider is implant lesions from microbial contamination; these may occur if there is not careful diagnosis and treatment planning . A factor of concern during treatment planning is the pulpal and periradicular condition of teeth adjacent to the implant site . Periradicular pathosis may jeopardize the implant . Therefore, if endodontic pathosis is identified, root canal treatment or extraction should be initiated before implant placement to prevent microbial contamination of the implant during healing . In reviewing clinical cases, the authors found several that illustrated problems with adjacent teeth that contributed to inflammation surrounding the implant. Lett Appl Microbiol, 1998 Nov, 27(5), 265 - 9 Mycobacterium tuberculosis complex DNA in calcified pleura from remains 1400 years old; Donoghue HD et al.; Mycobacterium tuberculosis complex DNA was isolated and identified in calcified pleura from remains 1400 years old, with the polymerase chain reaction . This is the first demonstration of tuberculosis in non-mummified archaeological tissue other than bone; the presence of mycobacterial mycolic acids in the sample supports this conclusion . The study of ancient DNA from microbial pathogens is of interest as it enables verification of traditional diagnoses, may answer long-standing questions in the history of disease, and provides ancient DNA sequences that can be compared with those of modern isolates. J Food Prot, 1998 Nov, 61(11), 1560 - 6 Simulation modeling for microbial risk assessment; Cassin MH et al.; Quantitative microbial risk assessment implies an estimation of the probability and impact of adverse health outcomes due to microbial hazards . In the case of food safety, the probability of human illness is a complex function of the variability of many parameters that influence the microbial environment, from the production to the consumption of a food . The analytical integration required to estimate the probability of foodborne illness is intractable in all but the simplest of models . Monte Carlo simulation is an alternative to computing analytical solutions . In some cases, a risk assessment may be commissioned to serve a larger purpose than simply the estimation of risk . A Monte Carlo simulation can provide insights into complex processes that are invaluable, and otherwise unavailable, to those charged with the task of risk management . Using examples from a farm-to-fork model of the fate of Escherichia coli O157:H7 in ground beef hamburgers, this paper describes specifically how such goals as research prioritization, risk-based characterization of control points, and risk-based comparison of intervention strategies can be objectively achieved using Monte Carlo simulation. J Food Prot, 1998 Nov, 61(11), 1550 - 9 Topics in dose-response modeling; Coleman M et al.; Great uncertainty exists in conducting dose-response assessment for microbial pathogens . The data to support quantitative modeling of dose-response relationships are meager . Our philosophy in developing methodology to conduct microbial risk assessments has been to rely on data analysis and formal inferencing from the available data in constructing dose-response and exposure models . The probability of illness is a complex function of factors associated with the disease triangle: the host, the pathogen, and the environment including the food vehicle and indigenous microbial competitors . The epidemiological triangle and interactions between the components of the triangle are used to illustrate key issues in dose-response modeling that impact the estimation of risk and attendant uncertainty . Distinguishing between uncertainty (what is unknown) and variability (heterogeneity) is crucial in risk assessment . Uncertainty includes components that are associated with (i) parameter estimation for a given assumed model, and (ii) the unknown "true" model form among many plausible alternatives such as the exponential, Beta-Poisson, probit, logistic, and Gompertz . Uncertainty may be grossly understated if plausible alternative models are not tested in the analysis . Examples are presented of the impact of variability and uncertainty on species, strain, or serotype of microbial pathogens; variability in human response to administered doses of pathogens; and effects of threshold and nonthreshold models . Some discussion of the usefulness and limitations of epidemiological data is presented . Criteria for development of surrogate dose-response models are proposed for pathogens for which human data are lacking . Alternative dose-response models which consider biological plausibility are presented for predicting the probability of illness. J Food Prot, 1998 Nov, 61(11), 1535 - 40 Estimating distributions of numbers of organisms in food products; Marks H et al.; Procedures of sampling and measurement contribute variability and uncertainty to exposure models that predict incidence and levels of organisms in food products . This paper focuses on methods that account for sampling and measurement error in fitting distributions of organisms in food products for use in exposure models for microbial risk assessment . Define y to be a measured density on a sample selected with stipulated probability from a population, and define x to be the "true" density for that sample . Designate the conditional distribution of y given the sample with "true" value x as g(y/x), and let F(x) be the unknown cumulative density of x . The distribution of the observed values y, h(y), can be expressed through the integral equation h(y) = integral of g(y/x) dF(x) . Knowledge of g(y/x) and h(y) enables an estimate of the unknown distribution of the organism's F(x) . In applications to risk assessment, use of continuous distributions described by a few parameters is desirable . Also desirable may be imputation or assignment of possible nonzero values for nondetect observations--those results below the limit of detection of the methodology--that may not be truly zero . This paper explores the use of the above formulation for estimating distributions of organisms used for microbial risk assessment and presents some simple examples. Biosens Bioelectron, 1998 Oct 1, 13(7-8), 795 - 9 Effects of high oxygen concentrations on microbial biosensor signals . Hyperoxygenation by means of perfluorodecalin; Reshetilov AN et al.; Amperometric biosensors register oxygen depletion in response to analyte catabolism, and thus are limited by the availability of dissolved oxygen . Microbial sensors containing immobilized cells of Gluconobacter oxydans were hyperoxygenated to 400% of control levels and the effects on sensor responses to glucose were determined . Oxygenated perfluorodecalin (a completely fluorinated organic substance) was as effective in hyperoxygenation as direct sparging with O2, increasing sensor base medium oxygen concentrations from 9.3 to 37 mg/l . Hyperoxygenation enhanced maximal biosensor response amplitudes, particularly at high cell loading densities . Maximal response rates were also improved, although less dramatically . Results suggest that hyperoxygenation may be a new general approach for modulating biosensor responses. Biosens Bioelectron, 1998 Oct 1, 13(7-8), 787 - 93 Detection of ethanol in a two-component glucose/ethanol mixture using a nonselective microbial sensor and a glucose enzyme electrode; Reshetilov AN et al.; Chemometric theory was applied to a microbial sensor for determinations of ethanol in the presence of glucose . Microbial sensors, consisting of Gluconobacter oxydans cells immobilized on Clark-type amperometric oxygen electrodes, exhibited good sensitivity but low selectivity toward ethanol and glucose . An Eksan-G commercial glucose analyzer was used as a second sensor for multivariate calibration and analyses . Microbial sensors exhibited nearly complete additivity for total glucose plus ethanol concentrations from 0.0 to 0.6 mM . Within this linear range, chemometric analyses provided estimates of ethanol concentration with measurement errors of less than 8% . Multivariate calibration thus is a promising approach to enhance the usefulness of microbial sensors. Biosens Bioelectron, 1998 Sep 15, 13(6), 653 - 63 Surface plasmon resonance biosensors as a tool in antibody engineering; Alfthan K; Modern gene technology combined with efficient microbial expression systems provides tools to produce antibodies with reduced functional size and improved binding properties as well as antibody fusions or novel antibodies . Surface plasmon resonance based biosensors, which measure antigen-antibody interactions in real-time, can be used for a diverse characterization of the modified antibodies . To date, the majority of published work originates from real-time biospecific interaction analysis based on the BIAcore instruments . This article describes the range of applications in antibody engineering in which BIAcore has been applied. Crit Rev Oral Biol Med, 1998, 9(4), 498 - 521 Periapical inflammatory responses and their modulation; Stashenko P et al.; Periapical inflammatory responses occur as a consequence of bacterial infection of the dental pulp, as a result of caries, trauma, or iatrogenic insult . Periapical inflammation stimulates the formation of granulomas and cysts, with the destruction of bone . These inflammatory responses are complex and consist of diverse elements . Immediate-type responses--including vasodilatation, increased vascular permeability, and leukocyte extravasation--are mediated by endogenous mediators, including prostanoids, kinins, and neuropeptides . Non-specific immune responses--including polymorphonuclear leukocyte and monocyte migration and activation, and cytokine production--are elicited in response to bacteria and their products . Interleukin-1 and prostaglandins in particular have been implicated as central mediators of periapical bone resorption . Chronic periapical inflammation further involves specific T- and B-cell-mediated anti-bacterial responses, and activates a network of regulatory cytokines which are produced by Th1- and Th2-type T-lymphocytes . Various naturally occurring and genetically engineered models of immunodeficiency are beginning to help elucidate those components of the immune system which protect the pulpal/periapical complex . Both specific and non-specific responses interface with and are regulated by the neural system . The modulation of these responses by immune response modifies, cytokine antagonists, and other novel therapeutic agents is discussed . As an experimental model, periapical inflammation has many advantages which permit it to be used in studies of microbial ecology and pathogenesis, host response, neuroimmunology, and bone resorption and regeneration. J Biotechnol, 1998 Sep 17, 64(1), 53 - 62 Novel techniques for analysing microbial diversity in natural and perturbed environments; Torsvik V et al.; Molecular techniques were applied for analysing the entire bacterial community, including both the cultivated and non-cultivated part of the community . DNA was extracted from samples of soils and sediments, and a combination of different molecular methods were used to investigate community structure and diversity in these environments . Reassociation of sheared and thermally denatured DNA in solution was used to measure the total genetical diversity . PCR-denaturing gradient gel electrophoresis (DGGE) analysis of rRNA genes gave information about changes in the numerically dominating bacterial populations . Hybridisation with phylogenetic group specific probes, and sequencing provided information about the affiliation of the bacterial populations . Using DNA reassociation analysis we demonstrated that bacterial communities in pristine soil and sediments may contain more than 10,000 different bacterial types . The diversity of the total soil community was at least 200 times higher than the diversity of bacterial isolates from the same soil . This indicates that the culturing conditions select for a distinct subpopulation of the bacteria present in the environment . Molecular methods were applied to monitor the effects of perturbations due to antropogenic activities and pollution on microbial communities . Our investigations show that agricultural management, fish farming and pollution may lead to profound changes in the community structure and a reduction in the bacterial diversity. Am J Obstet Gynecol, 1998 Nov, 179(5), 1248 - 53 A role for matrix metalloproteinase-9 in spontaneous rupture of the fetal membranes; Athayde N et al.; OBJECTIVES: Preterm premature rupture of fetal membranes is responsible for 30% to 40% of preterm deliveries . Fetal membranes are composed primarily of collagen . Matrix metalloproteinases are enzymes capable of degrading extracellular matrix macromolecules, including collagens . Expression of matrix metalloproteinase-9 (gelatinase B, 92 kd) and its tissue inhibitor (tissue inhibitor of metalloproteinase-1) has been localized in amnion and chorion . The objective of this study was to determine whether rupture of fetal membranes and intrauterine infection are associated with changes in the expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 . STUDY DESIGN: Two hundred one women in the following categories had amniotic fluid retrieved: (1) preterm labor and intact membranes in the presence (n = 42) or absence (n = 21) of microbial invasion of the amniotic cavity, (2) preterm premature rupture of the membranes with (n = 29) or without (n = 23) microbial invasion of the amniotic cavity, and (3) term gestation with intact membranes (n = 50) or with premature rupture of the membranes (n = 40) . Women in groups 1 and 2 were matched for gestational age at amniocentesis . Microbial invasion of the amniotic cavity was defined by a positive amniotic fluid culture for micro-organisms . Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were measured with use of sensitive and specific immunoassays that were validated for amniotic fluid . RESULTS: Spontaneous rupture of membranes at term is associated with a significant increase in the amniotic fluid concentrations of matrix metalloproteinase-9 (premature rupture of membranes, no labor: median 3.9 ng/mL, range 2 . 7 to 11.1 ng/mL vs no premature rupture of membranes, no labor: median <0.4 ng/mL, range <0.4 to 22.4 ng/mL; P <.001) . Patients with preterm premature rupture of the membranes had higher median matrix metalloproteinase-9 concentrations than those with preterm labor and intact membranes who were delivered at term (7.6 ng/mL, range <0.4 to 230.81 ng/mL vs <0.4 ng/mL, range <0.4 to 1650 ng/mL; P =.06) . Women with microbial invasion of the amniotic cavity had higher median matrix metalloproteinase-9 concentrations than did those without microbial invasion regardless of membrane status (preterm labor: 54.5 ng/mL, range <0.4 to 3910 ng/mL vs <0.4 ng/mL, range <0 . 4 to 1650 ng/mL; P <.01; preterm premature rupture of membranes: 179 . 8 ng/mL, range <0.4 to 611 ng/mL vs 7.6 ng/mL, range <0.4 to 230.81; P <.001) . CONCLUSION: Our data support a role for matrix metalloproteinase-9 in the mechanisms responsible for membrane rupture in term and preterm gestations. J Chemother, 1998 Oct, 10(5), 354 - 9 Assessment of presystemic factors on the oral bioavailability of rifampicin following multiple dosing; Zhang JN et al.; This study was carried out to elucidate the possible mechanism(s) responsible for reduced oral rifampicin bioavailability after multiple dosing . In addition to autoinduction, the relative contribution of the two possible controlling factors, e.g., intestinal metabolism and microbial degradation, was investigated using a rat model . Pharmacokinetic studies were carried out to assess the absolute rifampicin bioavailability by both oral and intravenous drug administration before and after 8 daily doses of 25 mg/kg . To estimate the possible involvement of microbial degradation, rifampicin kinetics were also assessed in rats on day 8 after receiving multiple oral dosing and concurrent administration of nonabsorbable triple antibiotics for gut sterilization 3 days prior to the study day . Pharmacokinetic parameters were generated by noncompartmental analysis . The results revealed a significant decrease in rifampicin levels for rats after multiple exposure, compared to single dosing; the mean clearance determined by intravenous dosing increased by 43% from 3.7 ml/min/kg and the half-life decreased by 24% from 238 min . However, the extent of decrease in rifampicin exposure following multiple dosing was substantially greater for rats dosed orally than intravenously; estimated absolute oral bioavailability decreased by 15% from 0.89 on day 1 to 0.76 on day 8 . No apparent alterations in any of the pharmacokinetic parameters were observed after gut sterilization, suggesting minimal contribution of microbial degradation to the reduction in oral rifampicin absorption after multiple dosing . In addition to hepatic enzyme autoinduction, these results strongly suggest the involvement of enhanced intestinal metabolism as a contributing factor to the decrease in oral rifampicin bioavailability following prolonged exposure. J Immunol, 1998 Nov 15, 161(10), 5673 - 80 IL-7 deficiency prevents development of a non-T cell non-B cell-mediated colitis; von Freeden-Jeffry U et al.; IL-7 is a stromal cell-derived cytokine with a well-established physiologic role in lymphocyte biology . This report describes an unexpected role for IL-7 in the development of colitis in a T and B cell-deficient environment . Recombination-activating gene-2 (RAG-2)-deficient mice (RAG-2(-/-)) were exposed to and subsequently maintained a horizontally transmitted microbial flora that included Helicobacter hepaticus . These animals mounted a strong myeloid cell response and developed both systemic and local signs of a severe colitis . A striking infiltration of F4/80 and MHC class II-positive cells was seen in the colon and cecum of animals undergoing the disease . Mice mutant for both IL-7 and RAG-2 (IL-7/RAG-2(-/-)) that were colonized by the same flora showed no signs of myeloid responses or colitis, indicating that IL-7 plays a critical role in exacerbating a non-T cell/non-B cell-mediated chronic inflammatory response . Recombinant IL-10 protein therapy was able to prevent the occurrence of colitis in susceptible mice, suggesting a pivotal role for macrophages . The implications of a role for IL-7 in this disease model with respect to human inflammatory bowel disease are discussed. Biochemistry, 1998 Nov 17, 37(46), 16192 - 200 Contribution of a conserved asparagine to the conformational stability of ribonucleases Sa, Ba, and T1; Hebert EJ et al.; The contribution of hydrogen bonding by peptide groups to the conformational stability of globular proteins was studied . One of the conserved residues in the microbial ribonuclease (RNase) family is an asparagine at position 39 in RNase Sa, 44 in RNase T1, and 58 in RNase Ba (barnase) . The amide group of this asparagine is buried and forms two similar intramolecular hydrogen bonds with a neighboring peptide group to anchor a loop on the surface of all three proteins . Thus, it is a good model for the hydrogen bonding of peptide groups . When the conserved asparagine is replaced with alanine, the decrease in the stability of the mutant proteins is 2.2 (Sa), 1.8 (T1), and 2.7 (Ba) kcal/mol . When the conserved asparagine is replaced by aspartate, the stability of the mutant proteins decreases by 1.5 and 1.8 kcal/mol for RNases Sa and T1, respectively, but increases by 0.5 kcal/mol for RNase Ba . When the conserved asparagine was replaced by serine, the stability of the mutant proteins was decreased by 2.3 and 1.7 kcal/mol for RNases Sa and T1, respectively . The structure of the Asn 39 --> Ser mutant of RNase Sa was determined at 1.7 A resolution . There is a significant conformational change near the site of the mutation: (1) the side chain of Ser 39 is oriented differently than that of Asn 39 and forms hydrogen bonds with two conserved water molecules; (2) the peptide bond of Ser 42 changes conformation in the mutant so that the side chain forms three new intramolecular hydrogen bonds with the backbone to replace three hydrogen bonds to water molecules present in the wild-type structure; and (3) the loss of the anchoring hydrogen bonds makes the surface loop more flexible in the mutant than it is in wild-type RNase Sa . The results show that burial and hydrogen bonding of the conserved asparagine make a large contribution to microbial RNase stability and emphasize the importance of structural information in interpreting stability studies of mutant proteins. Curr Opin Chem Biol, 1998 Oct, 2(5), 597 - 603 Technological advances in high-throughput screening; Fernandes PB; A variety of assay technologies continue to be developed for high-throughput screening . These include cell-based assays, surrogate systems using microbial cells such as yeast and bacterial two-hybrid and three-hybrid systems, and systems to measure nucleic acid-protein and receptor-ligand interactions . Modifications have been developed for cell-free, homogeneous assay systems, such as time-resolved fluorescence, fluorescence polarization and the scintillation proximity assay . Innovations in engineering and chemistry have led to delivery systems for nanoliter volumes and sensitive biosensors for ultra-high-throughout screening conducted in nanoliter and picoliter volumes . Spectroscopic methods have been extended to read single molecule fluorescence . Technologies are being developed to identify new targets from genomic information in order to design the next generation of screens. Clin Cancer Res, 1997 May, 3(5), 771 - 6 K252a inhibits proliferation of glioma cells by blocking platelet-derived growth factor signal transduction; Chin LS et al.; Growth factors are known to regulate glioma proliferation . The glioma cell lines U87 and T98G were examined for evidence of an autocrine stimulatory loop involving the neurotrophin family of growth factors . Although neurotrophin-3 and TrkC RNA were detected by reverse transcription-PCR, there was no evidence of significant interaction between neurotrophin-3 and its cognate receptor TrkC . The microbial alkaloid K252a has been described to inhibit both Trk tyrosine kinase activity and neuroblastoma cell proliferation . K252a inhibited proliferation in U87 (IC50 = 1170 nM) and T98G (IC50 = 529 nM) but induced apoptosis in U87 cells only . At concentrations of 500 nM to 1 microM, K252a blocked only platelet-derived growth factor (PDGF)-mediated receptor autophosphorylation . These results suggest that an autocrine loop involving PDGF is functional and important for maintaining tumor growth . There is no evidence to support the existence of a neurotrophin-mediated autocrine loop . K252a, through inhibition of PDGF signal transduction, may be a novel therapeutic agent in the treatment of human gliomas. J Travel Med, 1997 Jun 1, 4(2), 65 - 71 Dengue: A Literature Review and Case Study of Travelers from the United States, 1986-1994; Rigau-Perez JG et al.; Dengue fever is an acute, mosquito-transmitted viral disease characterized by fever, headache, arthralgia, myalgia, rash, nausea, and vomiting . Infections are caused by any of four virus serotypes (DEN-1, DEN-2, DEN-3, and DEN-4) . The incidence of dengue is increasing in most tropical areas throughout the world (Fig . 1) . Although dengue is not endemic in the continental United States, Hawaii, or Alaska, more than 500 laboratory-positive cases of introduced dengue were reported from 1977 through 1994 in U.S . residents who visited dengue-endemic areas throughout the world.1-4 In addition, two competent mosquito vectors (Aedes aegypti and Aedes albopictus) are found in the southeastern United States, and both could possibly transmit an introduced virus . In Hawaii, Ae . albopictus is the dominant mosquito on all islands; Ae . aegypti has only focal distribution on Molokai and the Kona coast of Hawaii . Economic, political, technologic, ecologic, and demographic changes have brought about the emergence of new microbial diseases, as well as an increase in the incidence of previously known infections . The increase in dengue activity in Asia, Africa, and the Americas represents a pandemic that is being facilitated by increased air travel; global urbanization; population growth; greater abundance of disposable, nondegradable containers that can serve as Aedes production sites; and lack of effective mosquito control programs.5,6 This report summarizes information about risk factors for severe disease, recent dengue outbreaks throughout the world, and cases of dengue virus infection in travelers who have been diagnosed on return to the United States. J Travel Med, 1997 Mar 1, 4(1), 8 - 10 A Cluster of Severe Reactions Following Improperly Administered Takeda Japanese Encephalitis Vaccine; Beecham III HJ et al.; Japanese encephalitis (JE) is an infection caused by a mosquito-transmitted virus present in many parts of Asia, including India, and Oceania . Infection is usually asymptomatic, leading to overt encephalitis in only 0.1-5% of infected individuals . When encephalitis occurs it is usually severe, with a 25% fatality rate, and 30% of cases resulting in permanent neurologic deficiencies . Since 1981, eight cases of JE have occurred in United States (U.S.) military personnel and their dependents stationed overseas.1 JE vaccine manufactured by Biken (Research Institute for Microbial Diseases, Osaka, Japan) is given to certain military personnel assigned to endemic areas in Asia . Concern about vaccine-associated hypersensitivity reactions has limited more widespread use . We report three cases of severe hypersensitivity following JE vaccination with a non-Biken JE vaccine (Takeda) under unusual circumstances. J Anim Sci, 1998 Oct, 76(10), 2717 - 29 Standardization of in situ techniques for ruminant feedstuff evaluation; Vanzant ES et al.; Over the last two decades, in situ techniques have been used extensively for measuring ruminal degradation of feedstuffs . Current predictive models put renewed emphasis on the need for quantitative information regarding rates and extents of ruminal degradation . However, in situ techniques suffer from tremendous variation, both within and among laboratories . A considerable number of studies have evaluated the influence of various factors on in situ-derived estimates of ruminal degradation . Factors that should be addressed in a standardized procedure include bag and sample sizes; bag material and pore size; sample processing; animal diet, feeding level, and frequency; bag insertion and removal procedures; location of bags within the rumen and containment procedures for the bags; rinsing procedures; microbial correction; incubation times; mathematical models; and numbers of replicate animals, days, and bags required to obtain repeatable estimates of ruminal degradation . Several recommendations that should increase the precision of in situ measurements are presented . Currently, the lack of standardization in rinsing techniques and the failure or inability to correct for microbial contamination of in situ residues seem to be the major sources of variability with in situ procedures. J Anim Sci, 1998 Oct, 76(10), 2649 - 56 Adding wheat middlings, microbial phytase, and citric acid to corn-soybean meal diets for growing pigs may replace inorganic phosphorus supplementation; Han YM et al.; Three experiments were conducted with 96 growing Landrace x Yorkshire x Duroc crossbreds to determine the collective effectiveness of cereal phytase from wheat middlings, microbial phytase, and citric acid in improving phytate-P bioavailability in corn-soy diets . In Exp . 1, 40 gilts (7 wk old) were fed five diets for 8 wk . Diets 1, 2, and 3 were low-P, corn-soybean meal diets (CSB) + 0, .1, or .2% inorganic P (Pi) as calcium phosphate, respectively . Diet 4 was a similar corn-soy diet that included 15% wheat middlings (461 cereal phytase U/kg) . Diet 5 was the CSB + microbial phytase (1,200 U/kg; Natuphos, BASF, Mount Olive, NJ) . In Exp . 2, 16 barrows (8 wk old) were fed two diets for 6 wk . Diet 1 was the same as Diet 3 of Exp . 1 (.2% Pi) . Diet 2 was Diet 4 of Exp . 1 + microbial phytase (300 U/kg) . In Exp . 3, 40 barrows and gilts (6 wk old) were fed four diets for 6 wk . Diets 1 and 2 were the same as those in Exp . 2 . Diet 3 was Diet 2 of Exp . 2 + 1.5% citric acid . Diet 4 was similar to Diet 3 but contained 10 instead of 15% wheat middlings . In Exp . 1, pigs fed the low-P, CSB (Diet 1) had lower (P < .05) ADG, ADFI, plasma Pi concentration, bone strength, and mobility score than pigs of the other four treatments . Measurements for pigs fed the 15% wheat middlings diet were not significantly different from those of pigs fed the CSB + .1% Pi or microbial phytase . In Exp . 2, ADG (P=.06) during wk 1 to 3 and gain:feed ratio (P < .02) and plasma Pi concentration (P < .005) during all weeks favored pigs fed the CSB + .2% Pi compared with the other diet including 15% wheat middlings . In Exp . 3, identical ADG during all weeks and similar plasma Pi concentrations at wk 4 and 6 were observed between pigs fed the two citric acid diets (Diets 3 and 4) and the CSB + .2% Pi (Diet 1) . Pigs fed Diet 4 (10% wheat middlings) had even higher (P < .02) gain:feed ratio during wk 1 to 3 than those fed Diet 1 . It seems feasible to completely replace calcium phosphate with 10 to 15% wheat middlings, 300 U microbial phytase/ kg, and 1.5% citric acid in the corn-soy diets for growing pigs. Virology, 1998 Nov 10, 251(1), 59 - 70 The effect of low-profile serine substitutions in the V3 loop of HIV-1 gp120 IIIB/LAI on the immunogenicity of the envelope protein; Peet NM et al.; Many microbial antigens contain powerful hypervariable epitopes that fail to induce broadly protective immunity because they dominate the immune response at the expense of more conserved but weaker epitopes . If the undesired B cell epitopes are eliminated, the immune system could be focused on the conserved epitopes and produce a stronger antibody response to conserved parts of the protein and thus become a more efficacious immunogen for a vaccine . We examined this possibility using the human immunodeficiency virus envelope glycoprotein (gp)120 IIIB/LAI and selectively replaced the amino acids from the V3 region and analyzed the overall immunogenicity of the mutant proteins after nucleic acid immunization in mice . The most variable residues of the human immunodeficiency virus type 1 gp120 V3 loop sequence were replaced with serine, which has a small uncharged hydrophilic side chain and therefore is likely to be less immunogenic than amino acids found in wildtype V3 sequences . The serine substitutions did not affect the ability of soluble CD4 to bind the mutant molecules compared with wildtype gp120 and monoclonal antibodies against both linear and discontinuous epitopes located in the V1/V2, C1, and C4 regions of the molecule . These data suggest that the V3 loop substitutions did not grossly affect the overall conformation of the envelope molecule . Immunization of CBA x BALB/c F1 mice with DNA expression plasmids for the wild-type gp120 sequence induced a predominantly IgGI antibody response with end point titers of 10(4)-5 x 10(4) . The antibodies reacted only with conformationally intact gp120 . Serine replacements targeted to both sides of the V3 loop had a major impact on gp120 immunogenicity, with a markedly reduced response in the majority of animals tested . Analysis of the epitope specificity of the responses suggests that N-terminal amino acids in the V3 loop contribute to the major immunodominant epitope and provides no evidence that their removal enhances immunogenicity of the conserved regions . Lett Appl Microbiol, 1998 Oct, 27(4), 203 - 6 Evidence that sorbic acid does not inhibit yeast as a classic 'weak acid preservative'; Stratford M et al.; Weak-acid preservatives are widely used to maintain microbial stability in foods and beverages . Classical weak-acid theory proposes that undissociated acid molecules pass through the plasma membrane, dissociate in the neutral pH of the cytoplasm, release protons and inhibit growth through acidification of the cytoplasm . Inhibitory concentrations of sorbic acid are shown to liberate fewer protons than other weak-acid preservatives . Sorbic acid shows similar inhibition to other six-carbon acids, alcohols and aldehydes, the latter being unable to act as weak acids . A survey of 22 yeasts showed high correlation between sorbate resistance and ethanol tolerance . Inhibition by short-chain acids or alcohols showed strong correlation with lipophilicity . It is proposed that sorbic acid acts as a membrane-active substance rather than as a weak-acid preservative. J Dairy Sci, 1998 Oct, 81(10), 2595 - 603 H(+)-coupled uphill transport of the dipeptide glycylsarcosine by bovine intestinal brush-border membrane vesicles; Wolffram S et al.; In monogastric species, a considerable portion of amino acid nitrogen is absorbed across the brush-border membrane of the small intestine as small peptides (e.g., tripeptides and dipeptides) . In ruminants, however, this process is less clear . Therefore, we investigated the uptake of radioactively labeled glycylsarcosine as a model dipeptide across the intestinal brush-border membrane using brush-border membrane vesicles prepared from the bovine small intestine . Uphill transport of glycylsarcosine was energized by a transmembrane H+ gradient and was further stimulated by an electrical potential difference across the membrane . Transport mediated by a carrier contributes to total glycylsarcosine transport across the brush-border membrane . Comparison of the apparent kinetic constants between brush-border membranes prepared from the proximal jejunum or ileum revealed similar half-saturating substrate concentrations (1.28 and 0.93 mmol/L for proximal jejunum and ileum, respectively), but maximal transport rates appeared to be somewhat higher in the proximal small intestine (2.15 and 1.20 nmol/mg of protein per 3 s for proximal jejunum and ileum, respectively) . Uptake of glycylsarcosine was strongly inhibited by other dipeptides, but the amino acids glycine and sarcosine did not affect transport . Inhibition of glycylsarcosine uptake by cephalexin indicated an affinity of the carrier for cephalosporin antibiotics . Transport of intact dipeptides across the brush-border membrane of the small intestine might be of physiological importance in ruminants because the microbial and dietary proteins resistant to rumen degradation are digested and absorbed in the small intestine. J Am Coll Cardiol, 1998 Nov, 32(5), 1384 - 8 Safety and efficacy of hydrogen peroxide plasma sterilization for repeated use of electrophysiology catheters; Bathina MN et al.; OBJECTIVES: The purpose of this study was to evaluate a new technique for sterilizing nonlumen electrophysiology catheters that uses hydrogen peroxide gas plasma . BACKGROUND: The reuse of electrophysiology catheters may potentially result in a significant cost savings . While ethylene oxide sterilization appears to be safe and effective from a clinical standpoint, toxic ethylene oxide residuals, which exceed Food and Drug Administration standards, have been reported . METHODS: Ten nonlumen electrophysiology catheters were extensively evaluated . Each catheter was used five times and resterilized after each use with hydrogen peroxide gas plasma . Tests for sterility, mechanical and electrical integrity, chemical residuals and standard and electron microscopic inspection were performed . RESULTS: Loss of electrical integrity or mechanical integrity was not observed in any catheter . No evidence of microbial contamination was found . Surface integrity was preserved except for one ablation catheter that exhibited fraying of the insulation at the insulation-electrode interface . Surface inspection using standard magnification and electron microscopy revealed no significant change in surface characteristics associated with the sterilization process . Hydrogen peroxide was the only chemical residual noted, with an average concentration of 0.22% by weight, which is within accepted American Association for the Advancement of Medical Instrumentation limits . The cost for a standard electrophysiology catheter ranges from $200 to $800, and one sterilization cycle costs $10 . If electrophysiology catheters are used five times, resterilization could potentially result in a savings of $2,000 per catheter, or $9,000 for five ablation procedures . CONCLUSIONS: Hydrogen peroxide gas plasma sterilization may provide a cost-effective means of sterilizing nonlumen electrophysiology catheters without the problem of potentially harmful chemical residuals . However, careful visual inspection of catheters, particularly at the insulation-electrode interface, is required if catheter reuse is performed. Carcinogenesis, 1998 Oct, 19(10), 1815 - 9 Prevention of colonic aberrant crypt foci and modulation of large bowel microbial activity by dietary coffee fiber, inulin and pectin; Rao CV et al.; The present experiments were aimed at developing novel dietary fibers to aid in reduction of colon cancer risk . We assessed the effects of coffee (non-fiber fraction), coffee fiber (arabino-galactose polymer) and inulin (oligo-fructose) in male F344 rats using formation of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the colon as the measure of preventive efficacy (or lack of such) . At 5 weeks of age, groups of rats were fed the AIN-76A (control) and experimental diets that contained 1% coffee, 10% coffee fiber, 10% inulin, 10% pectin (positive control for fiber) or 200 p.p.m . piroxicam (a known ACF inhibitor) . At 7 weeks of age, all animals were s.c injected with AOM (15 mg/kg body wt) once weekly for 2 weeks . All rats were killed 8 weeks after the last AOM injection and ACF were counted . The contents of the cecum were analyzed for bacterial beta-glucuronidase activity and short-chain fatty acids (SCFAs) . Dietary administration of coffee fiber significantly suppressed AOM-induction of colonic ACF, in terms of total number, as well as crypt multiplicity and number of ACF/cm2 colon (P < 0.01-0.001) . Inulin diet had no significant effect on total ACF, but had reduced the number of ACF/cm2 (P < 0.05) . Whereas coffee had no effect on ACF formation, 10% pectin diet and 200 p.p.m . piroxicam significantly suppressed colonic ACF (P < 0.001) as had been expected . A significant reduction of cecal beta-glucuronidase activity was observed in the rats fed coffee, coffee fiber and pectin diets . Further, coffee fiber, inulin and pectin increased cecal SCFA levels 3- to 5-fold . These results suggest that coffee fiber can prevent colon cancer risk . Further studies are warranted to determine the full potential of this fiber in pre-clinical efficacy studies. Microbiology, 1998 Oct, 144 ( Pt 10), 2803 - 8 Phylogenetic mapping of bacterial morphology; Siefert JL et al.; The availability of a meaningful molecular phylogeny for bacteria provides a context for examining the historical significance of various developments in bacterial evolution . Herein, the classical morphological descriptions of selected members of the domain Bacteria are mapped upon the genealogical ancestry deduced from comparison of small-subunit rRNA sequences . For the species examined in this study, a distinct pattern emerges which indicates that the coccus shape has arisen and accumulated independently multiple times in separate lineages and typically survived as a persistent end-state morphology . At least two other morphologies persist but have evolved only once . This study demonstrates that although bacterial morphology is not useful in defining bacterial phylogeny, it is remarkably consistent with that phylogeny once it is known . An examination of the experimental evidence available for morphogenesis as well as microbial fossil evidence corroborates these findings . It is proposed that the accumulation of persistent morphologies is a result of the biophysical properties of peptidoglycan and their genetic control, and that an evolved body-plan strategy based on peptidoglycan may have been a fate-sealing step in the evolution of Bacteria . More generally, this study illustrates that significant evolutionary insights can be obtained by examining biological and biochemical data in the context of a reliable phylogenetic structure. Int J Food Microbiol, 1998 Sep 8, 43(3), 195 - 203 Final optical density and growth rate; effects of temperature and NaCl differ from acidity; Krist KA et al.; Most predictive models used in food microbiology accurately describe microbial growth rate responses to conditions in the environment, but do not improve understanding of mechanisms . The effects of temperature, water activity and acid constraints on the growth of Escherichia coli are investigated using substrate-limited batch culture experiments . Final optical densities of substrate-limited batch cultures indicate the efficiency of substrate conversion to biomass and, therefore, the relative energetic burdens that different environmental conditions pose for microbial growth . Typical growth rate responses are observed . At suboptimal temperatures, the square root of growth rate declines linearly with temperature . With increasingly stringent water activity conditions, the growth rate declines linearly . It also declines linearly (but only slightly) with increasing hydrogen-ion concentration . Similar deltaOD (the change in optical density from the initial value to the value where the final population density is reached) responses are observed for temperature and water activity (adjusted using sodium chloride) . Over most of the growth permissive ranges, the deltaOD remains high for both factors . Close to the growth boundaries, however, at the low water activity extreme and at the low and high temperature extremes, cell production declines to zero suddenly . The influence of water activity on growth rate is partly relieved by the compatible solute betaine . However, the main influence of betaine on deltaOD is to extend (to a lower water activity value) the water activity growth boundary and, therefore, the water activity value where cell production declines suddenly . In contrast to the temperature and water activity responses, the deltaOD declines steadily with increasing hydrogen-ion concentration . This indicates that temperature and water activity constraints, despite their marked influence on growth rate, may not impose large energetic burdens . However, when acid stress is applied, the efficiency of substrate conversion to biomass appears to be reduced. Semin Immunol, 1998 Oct, 10(5), 383 - 90 Role of early cytokines, including alpha and beta interferons (IFN-alpha/beta), in innate and adaptive immune responses to viral infections; Biron CA; Innate cytokine responses are important mediators of early defense against infections . Certain of their effects can be delivered directly to activate protective mechanisms in infected cells . Others activate innate immune cells, including natural killer (NK) cells and macrophages, to mediate defense . Still others shape adaptive immune responses . The compositions and magnitudes of innate cytokine responses are modulated, by the nature of the infectious agent, to facilitate accessing of the anti-microbial defense functions most beneficial in defense against the particular infection . In the context of viral infections, interferons alpha and beta (IFN-alpha/beta) are induced to high levels, and help to mediate and regulate immune responses most effective against this class of agents . The cytokines induce anti-viral mechanisms in infected cells, negatively regulate interleukin 12 expression, and activate NK cell-mediated lysis . Protective development of adaptive immunity to viral infections includes prominent CD8 T cell expansion and activation, and IFN-alpha/beta can mediate functions with the potential to promote these T cell responses . Together, the characteristics define regulation of unique or unique prominent defense mechanisms in place to fight off viral infections . Semin Immunol, 1998 Oct, 10(5), 355 - 61 The complement system and adaptive immunity; Fearon DT; The complement system covalently attaches C3d to microbial antigens which binds to CR2 on B lymphocytes, leading to a markedly enhanced adaptive immune response to that antigen . The enhancement is mediated by the cross-linking of the CR2-CD19 complex to mIg which augments the activation of several intracellular signalling pathways . Two additional receptors of the B lymphocyte, FcgammaRIIB and CD22, have opposing effects when cross-linked to mIg, the former suppressing signalling by recruiting the inositol phosphatase, SHIP, and the latter by activating the phosphotyrosine phosphatase, SHP-1 . Two principles emerge from these studies: innate immunity guides the adaptive immune response, and activation of the B lymphocyte is determined by co-receptors which evaluate the biological characteristics of antigen . Oncology (Huntingt), 1998 Oct, 12(10), 1521 - 30; discussion 1532-4 Early detection of cutaneous lymphoma; Abd-el-Baki J et al.; Cutaneous lymphomas comprise a spectrum of diseases characterized by infiltration of the skin by malignant lymphocytes . The clinical manifestations of cutaneous lymphomas vary, and they can mimic benign dermatoses, as well as nodal or visceral malignancies with cutaneous spread . Cutaneous lymphomas are divided into T-cell lymphomas and B-cell lymphomas . Cutaneous T-cell lymphomas include mycosis fungoides, Sezary syndrome, lymphomatoid papulosis, CD30+ large cell lymphoma, and adult T-cell leukemia/lymphoma . The extent and severity of skin manifestations in cutaneous T-cell lymphomas are prognostic indicators of extracutaneous involvement . Primary cutaneous B-cell lymphomas comprise 10% to 25% of all primary cutaneous non-Hodgkin's lymphomas and are classified according to their cell of origin . Most cutaneous B-cell lymphomas have an indolent course and excellent prognosis when compared to their nodal counterparts . Many factors have been implicated in the etiology of cutaneous lymphomas, including chemical and drug exposures, as well as microbial agents, such as the Epstein-Barr virus (EBV), human T-lymphocyte virus-1 (HTLV-1), and Borrelia burgdorferi . Immunohistochemistry and lymphocyte-receptor gene rearrangement studies are useful in distinguishing malignant from benign conditions. J Food Prot, 1998 Oct, 61(10), 1352 - 7 Microbial populations of Botrytis cinerea-inoculated strawberry fruit exposed to four volatile compounds; Ntirampemba G et al.; Aerobic, microaerophilic, coliform, and mold populations of Botrytis cinerea-inoculated strawberry fruit not exposed (control) or exposed to low and high quantities of four volatile compounds during storage at 2 degrees C were determined after storage for 7 days and after removal of the volatile and transfer to 22 degrees C for 3 days . Fruit harvested at the ripe stage were inoculated with 10(6) conidia B . cinerea per ml and were placed in plastic containers containing no volatile compound (control) or two quantities of (E)-2-hexenal (10 or 100 microliters), (E)-2-hexenal diethyl acetal (30 or 300 microliters), benzaldehyde (30 or 300 microliters), or methyl benzoate (12 or 60 microliters) . The fruit containers were overwrapped with a low-density polyethylene film, sealed, stored at 2 degrees C for 7 days, and then transferred to 22 degrees C for 3 days . Aerobic, microaerophilic, and coliform populations of fruit exposed to volatile compounds tended to be lower than the controls after storage at 2 degrees C for 7 days and, depending on the volatile compound, similar, lower, or higher than the controls after transfer and storage at 22 degrees C . However, due to variability in initial aerobic, microaerophilic, and coliform populations of the fruit used in the different trials (P < 0.05), none of the differences between control and treatment and between treatments within a sample time were significant (P > 0.05) . Strawberry fruit exposed to 100 microliters of (E)-2-hexenal was the only treatment that did not show a significant increase in mold populations after transfer and storage at 22 degrees C for 3 days . Additional studies are needed to determine if (E)-2-hexenal can be used in combination with other postharvest storage conditions, such as low temperature and controlled/modified atmosphere, to delay mold spoilage and extend the shelf life of the strawberry. Immunol Cell Biol, 1998 Oct, 76(5), 441 - 7 Cell-cell signalling in the regulation of blood cell formation and function; Metcalf D; Blood cell formation is continuous in adult life and requires complex regulatory control to achieve the necessary cell proliferation, differentiation commitment and maturation . Much of this control is achieved by specific glycoprotein haemopoietic regulators, more than 20 of which have now been identified and produced in recombinant form . For the granulocyte-macrophage lineage, major regulators are the colony stimulating factors (CSF) that are produced by many cell types dispersed throughout the body . The production of CSF is rapidly increased in response to induction signals, most usually of microbial origin, representing a demand-generated signalling system designed to activate and generate cells to rapidly eliminate the micro-organisms . The CSF not only control cell division but certain aspects of differentiation commitment, maturation initiation and functional activation . These multiple responses are initiated by signals arising from different regions of the cytoplasmic domains of the CSF membrane receptors . Less well understood are the signalling systems controlling the special gene activation events required to initiate the formation of the first haemopoietic cells and the specialized microenvironmental cells needed to support haemopoietic cells as they respond to haemopoietic regulators. Appl Environ Microbiol, 1998 Nov, 64(11), 4410 - 5 Analysis of airborne actinomycete spores with fluorogenic substrates; Gazenko SV et al.; The reactions between seven fluorogenic substrates and different groups of enzymes, esterases, lipases, phosphatases, and dehydrogenases, were studied in a search for a new method for the detection of actinomycete spores . Fluorescence measurement was chosen as a fast and sensitive method for microbial analysis . The focus of the research was on the spores of important air contaminants: Streptomyces albus and Thermoactinomyces vulgaris . For the measurement of the enzymatic activity, the chosen fluorogenic substrate was added to a mixture of spores and nutrient media, and the resulting fluorescence was measured with a spectrofluorometer . Fluorogenic substrates were found to show enzymatic activities even for dormant spores . Comparison of the enzymatic activities of dormant spores with those of vegetative cells showed similarity of the enzymatic profiles but higher activity for vegetative cells . The increase of enzymatic activity from dormant spores to vegetative cells was not linear but fluctuating . The largest fluctuations were found after 4 to 5 h of incubation . The enzymatic activities of S . albus were 10 to 50 times lower than those of T . vulgaris, except for the dehydrogenase activity, which was seven times higher . These results indicate that analysis with fluorogenic substrates has the potential for becoming a fast and sensitive method for the enumeration and identification of airborne actinomycete spores. Reprod Nutr Dev, 1998 Jul-Aug, 38(4), 401 - 16 The effect of Saccharomyces cerevisiae and Aspergillus oryzae on the digestion of the cell wall fraction of a mixed diet in defaunated and refaunated sheep rumen; Jouany JP et al.; The objective of this study was to determine the effect of two probiotics, Saccharomyces cerevisiae (SC) and Aspergillus oryzae (AO), without their culture medium, on the digestion of plant cell wall components in sheep that had been successively defaunated and refaunated . Six sheep fitted with large rumen cannulae were used to study 1) defaunated sheep with no probiotic, 2) defaunated sheep with SC or AO, 3) refaunated sheep with no probiotic, 4) refaunated sheep with SC or AO . The apparent digestibility of the plant cell walls was not altered (P > 0.05) by the probiotics in defaunated sheep but was increased (P < 0.05) with SC (+16%) in refaunated sheep . Simultaneously, SC stimulated the growth of the protozoal population in the rumen . As noted in most previous experiments, the positive effect of the presence of protozoa on plant cell wall digestion (P < 0.001) was confirmed here . The effect (P > 0.05) of SC or AO on in situ ADF digestion was either not significant or negative in defaunated rumens, whereas it became positive in refaunated rumen after a residence time of 12 h . The improvement of in situ ADF digestion due to the presence of protozoa was significant (P < 0.05 for NDF; P < 0.001 for ADF) . However, we could not determine whether this was a direct effect of protozoa or an indirect effect operating via bacteria . The limits of the nylon bag technique for evaluating the microbial activity are discussed in relation to the ability of protozoa to enter and grow in the bags, and the pH regulation inside the bags . The pH values below 5.5 noted inside the bags can significantly alter the bacterial and protozoal populations and limit the validity of the technique . SC increased (P < 0.05) the specific activity of CMCase and xylanase of the solid-adherent bacteria (SAB) isolated from the rumen digesta of refaunated sheep . Stimulation of both the bacterial activity and protozoa numbers could explain the positive effect of SC on cell wall digestion in the rumen since the modelling of marker excretion in faeces showed that the ruminal mean retention time of hay measured from the model of Danhoa et al . was not modified (P > 0.05) by either refaunation or the presence of probiotics . AO increased (P < 0.05) the total retention time of the solid particles in the whole digestive tract and increased the ruminal liquid volume in the refaunated animals but it had no effect on the protozoa population or on the polysaccharidase activity of the SAB, which could explain the absence of effect of AO on the total digestibility of plant cell walls . Both probiotics decreased the liquid turnover in defaunated rumens (P < 0.05) but neither had any effect (P > 0.05) on this parameter after refaunation . The improvement of plant cell wall degradation in the whole digestive tract is probably due to a stimulation of digestion at the rumen level as indicated by the higher activity of the SAB in rumen digesta and the growth of protozoa. Immunol Rev, 1998 Aug, 164, 175 - 84 Diversification of response to hsp65 during the course of autoimmune arthritis is regulatory rather than pathogenic; Moudgil KD; Determinant spreading has been implicated in the pathogenesis of certain autoimmune diseases in animal models . We have observed that during the course of adjuvant arthritis (AA) in the Lewis rat, there is 'diversification' of response to the bacterial 65-kDa heat shock protein (Bhsp65) towards its carboxy-terminal determinants (BCTD) . Strikingly, pretreatment of naive Lewis rats with BCTD affords significant protection from AA . Our preliminary studies indicate that the diversification of response to BCTD in the Lewis rat is probably triggered in vivo by the induction and enhanced processing of self(rat) hsp65 . Thus, the self hsp65-directed T-cell responses appear to be involved in mediating natural remission from acute inflammatory arthritis induced by a foreign antigen, Mycobacterium tuberculosis . This the first report describing that the new T-cell specificities arising during the course of an autoimmune disease are regulatory/protective rather than pathogenic . Moreover, our results suggest that a final common mechanism involving BCTD might be recruited by other rat strains which either are resistant to AA (WKY rats) or whose susceptibility to AA is modulated significantly by microbial flora (Fisher rats) . The results of this study would contribute significantly to understanding of the pathogenesis of human rheumatoid arthritis, and in devising new therapeutic strategies for this disease. Immunol Rev, 1998 Aug, 164, 169 - 74 Heat-shock protein T-cell epitopes trigger a spreading regulatory control in a diversified arthritogenic T-cell response; van Eden W et al.; Adjuvant arthritis (AA) in Lewis rats is T-cell mediated and seems to depend on T cells recognising the 180-188 epitope of mycobacterial heat-shock protein (hsp) 60 . Analysis of arthritogenic T-cell clone A2b has revealed a mimicry of this particular epitope with an articular cartilage-associated target T-cell epitope . Nasal administration of synthetic peptides covering this 180-188 sequence led to epitope-specific tolerance and resistance to AA . Since this tolerisation protocol also inhibited avridine arthritis, one may conclude that this form of epitope-specific tolerance had effectuated a spreading tolerisation at the level of target antigens that included a diverse set of possible arthritis-associated antigens . In vitro anergised T cells exhibited suppressive activity in a co-culture system . As in this case--depending on the presence of the antigen of the anergic T cell--such T cells suppressed responder T cells of a different antigenic specificity, we postulated that anergic T cells may be responsible for a spreading of tolerance . It seemed that such spreading of tolerance was channelled through the antigen-presenting cells (APC) and was dependent on direct cell-cell contact . This and additional forms of spreading of tolerance could be responsible for specific nasal tolerance, causing inhibition of the development of an arthritogenic inflammatory response . This can be similarly the case for the arthritis protection that resulted from immunisation with hsps . Analysis of T-cell responses following hsp immunisations revealed that the arthritis inhibitory activity resided in T cells with specificity for a conserved part of microbial hsp 60 . The same T cells cross-responded to rat self-hsp60 . Low level expression of the latter molecule on non-professional APC could possibly have induced a suppressive anergic state in these autoreactive cells . Thus, immunisation with microbial hsp would have led to an expansion of such T cells, leading to raised disease-suppressive potential when selectively trapped and activated in the inflamed self-hsp-overexpressing joint . Alternatively, the cross-recognised self-hsp epitope could have the regulatory qualities of an altered peptide ligand or a partial agonist for T cells that see the microbial homologue as the full agonist. Curr Opin Immunol, 1998 Oct, 10(5), 539 - 42 Zoonosis in xenotransplantation; Patience C et al.; Species barriers against microbial infection will be lowered to an unprecedented degree in xenotransplantation settings . Our knowledge about micro-organisms in donor animals is limited and it is difficult to predict the consequence of such cross-species infection. J Biol Chem, 1998 Nov 6, 273(45), 29776 - 85 Multiple forms of arginase are differentially expressed from a single locus in Neurospora crassa; Marathe S et al.; The Neurospora crassa catabolic enzyme, arginase (L-arginine amidinohydrolase, EC 3.5.3.1), exists in multiple forms . Multiple forms of arginase are found in many vertebrates, but this is the only reported example in a microbial organism . The two major forms are structurally similar with subunit sizes of 36 and 41 kDa, respectively . The larger form is produced by mycelia growing in arginine-supplemented medium . Both forms are localized in the cytosol . The structural gene for arginase, aga, has been cloned and sequenced; it contains a 358-codon open reading frame with three in-frame ATGs at the amino terminus . Mutagenesis of these ATGs revealed that the first ATG initiates the 41-kDa protein and the third ATG initiates the 36-kDa protein . Mutation of the second ATG has no effect on translation . Northern analysis demonstrated that a 1.4-kilobase (kb) transcript is synthesized in minimal medium and both a 1.4- and 1.7-kb transcript are produced in arginine-supplemented medium . Primer extension identified the 5' ends of each transcript and demonstrated that the first and third ATG of the open reading frame are the initial AUGs of the 1.7- and 1 . 4-kb mRNA, respectively . The results suggest that a basal promoter produces the 1.4-kb transcript and an arginine "activated" promoter is responsible for the 1.7-kb transcript . Tandem promoters are rare in eukaryotic organisms, and they often regulate developmental or tissue-specific gene expression . The possibility that arginase has a role in differentiation in N . crassa is being investigated. Toxicon, 1998 Nov, 36(11), 1493 - 502 An overview of the marine food poisoning in Mexico; Sierra-Beltran AP et al.; In the course of the last decade, huge events related to harmful algal blooms (HAB) have severely affected the environment in Mexico, even causing several human casualties . The tally of the toxins known up to date in Mexican waters includes: neurotoxin shellfish poisoning (NSP), paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), tetrodotoxin (TTX) or puffer fish poisoning, ciguatera fish poisoning (CFP) and diarrhetic shellfish poisoning (DSP) . Actual epidemiological figures profoundly modified the trends manifested on previous decades . Notwithstanding that the red tides are a long time known phenomena in Mexican coasts, no regular observation of the marine environment has been set up . Although there are monitoring activities for PSP toxins on the shellfish culturing facilities that are exploited for export to the U.S.A., these are only effectively applied on specific spots of the Mexican coasts, implying that the biggest part of the country coastal zones are not formerly surveyed . The misleads caused by the medical conception that food poisoning events are mainly due to microbial contamination, is among the factors why the marine food poisoning events are a neglected disease . In spite of the fact that no official statistics consider HAB related events as a subject of research or further monitoring by the health authorities, sporadic scientific documents related to poisoning events were produced in Mexico . An interesting picture is presented for most of the marine toxins mentioned . Trend and prognosis estimates made with such scarce information, provide a minimum measurement of the reality and urge the need for a permanent monitoring program on the Mexican coasts, a place with one of the greatest marine toxin diversity worldwide. Khirurgiia (Mosk), 1998, (9), 11 - 3 {Role of B.A . Petrov in foundation and development of free flap skin transplantation problem}; Smirnov SV et al.; The article reviews the history of development of free-flap skin transplantation and basic role of acad . B.A . Petrov who was the first to show the role of dermatom skin transplantation in vast granulating wounds as the only method saving the life of patients with severe burns . He also suggested to solve an actual problem--deficiency of resources of donor skin--by repeated excision of skin flaps from previously used donor sites and use of cadaver skin . Very important is ales the role of B.A . Petrov in development of such particular questions as the role of patient's condition, wound bed am microbial flora of the wound in survival of skin transplants . In aspect of historical relationships the perspective of new approach to treatment of deep burns by transplantation of ceratinocytes, cultivated outside the patient's organism is shown. Anaesthesiol Reanim, 1998, 23(4), 93 - 8 {Value of aspiration of tracheal secretions and bronchoalveolar lavage in diagnosis of nosocomial pneumonia in ventilated patients}; Schreiber T et al.; The diagnostic value of endotracheal aspirates with quantitative assessment and bronchoalveolar lavage (BAL) was investigated in 104 mechanically ventilated patients in an anaesthesiologic/surgical intensive care unit . Patients were either considered as "pneumonia positive" (77 patients) according to clinical, radiological or laboratory criteria or "pneumonia negative" (27 patients) . Using a threshold of 10(5) colony forming units (cfu) per ml for endotracheal aspirates and 10(4) cfu/ml for BAL-fluid, the results were similar for both techniques (sensitivity 74% and 77% respectively; specifity 63%) . In our investigation, in 80% of the cases microbial growth was observed in either both or neither of the techniques . Therefore 20% of the patients had positive results in only one of the two diagnostic procedures . As a consequence of the presented study, quantitative assessment of endotracheal aspirates as a cost-effective, low-invasive and simple technique could be helpful in diagnosing nosocomial pneumonia in mechanically ventilated patients . Performance of BAL is indicated in patients with clinical signs of nosocomial pneumonia and negative results in endotracheal aspirates (< 10(5) cfu/ml) . Nevertheless, diagnostic uncertainty will remain in about 15% of all cases, even when both techniques are applied . The primary use of invasive bronchoscopic techniques, such as BAL, in diagnosis of nosocomial pneumonia has to be considered critically. Trends Cell Biol, 1998 Oct, 8(10), 384 - 7 Cellular microbiology: cycling into the millennium; Henderson B et al.; Cellular microbiology is a newly developing science born from the realization that many different aspects of eukaryotic cell biology are targeted by microbial virulence mechanisms . One example of this is the emerging evidence that several bacteria can interfere, directly or indirectly, with the eukaryotic cell cycle . This article discusses the cell-cycle effects of bacterially generated molecules, their role in virulence and their possible therapeutic potential. Proc Natl Acad Sci U S A, 1998 Oct 27, 95(22), 13108 - 13 PCR-based subtractive hybridization and differences in gene content among strains of Helicobacter pylori; Akopyants NS et al.; Genes that are characteristic of only certain strains of a bacterial species can be of great biologic interest . Here we describe a PCR-based subtractive hybridization method for efficiently detecting such DNAs and apply it to the gastric pathogen Helicobacter pylori . Eighteen DNAs specific to a monkey-colonizing strain (J166) were obtained by subtractive hybridization against an unrelated strain whose genome has been fully sequenced (26695) . Seven J166-specific clones had no DNA sequence match to the 26695 genome, and 11 other clones were mixed, with adjacent patches that did and did not match any sequences in 26695 . At the protein level, seven clones had homology to putative DNA restriction-modification enzymes, and two had homology to putative metabolic enzymes . Nine others had no database match with proteins of assigned function . PCR tests of 13 unrelated H . pylori strains by using primers specific for 12 subtracted clones and complementary Southern blot hybridizations indicated that these DNAs are highly polymorphic in the H . pylori population, with each strain yielding a different pattern of gene-specific PCR amplification . The search for polymorphic DNAs, as described here, should help identify previously unknown virulence genes in pathogens and provide new insights into microbial genetic diversity and evolution. Phytochemistry, 1998 Oct, 49(4), 971 - 8 Production and characterisation of monoclonal antibodies to phytoene synthase of Lycopersicon esculentum; Fraser PD et al.; Monoclonal antibodies have been prepared against the tomato (Lycopersicon esculentum Mill.) fruit ripening-enhanced phytoene synthase (PSY1) . The antigen was prepared as a beta-galactosidase fusion protein by cloning a 1.13 kb fragment of Psy1 cDNA into pUR291, followed by transformation of E . coli . The fusion protein, induced by IPTG, was purified by preparative SDS-PAGE and used to elicit an immune response . The cell lines were screened for cross-reactivity against beta-galactosidase-phytoene synthase fusion protein in E . coli extracts using western blotting and ELISA detection procedures . Positive clones were further screened for their ability to cross-react with the mature phytoene synthase protein on western blots as well as their ability to inhibit enzyme activity . Eleven monoclonal lines were obtained . Nine of these, all of the IgM isotype, exhibited strong responses to phytoene synthase of ripe tomato fruit on western blots, but did not inhibit enzyme activity effectively . The other two lines (IgG/la 2 isotypes) inhibited phytoene synthase activity in ripe tomato stroma, but produced a poor response to the protein on western blots . The monoclonals identified a ripe fruit phytoene synthase of 38 kDa, exclusively located in the chromoplast . In contrast, antibodies were unable to detect microbial phytoene synthases, nor phytoene synthase of maize leaf, tomato chloroplast or mango fruit extracts, either on western blots or from inhibition of phytoene synthase activity . However, they did cross-react with a 44 kDa protein from carrot leaf stroma and with three different proteins (44, 41, and 37 kDa) in carrot root . Cross-reactivity was also found with a 37 kDa protein from pumpkin fruit stroma. Phytochemistry, 1998 Oct, 49(4), 957 - 63 A cysteine proteinase inhibitor purified from apple fruit; Ryan SN et al.; A cysteine proteinase inhibitor has been purified from immature fruit of Malus domestica (var . Royal Gala) . The M(r) of this apple cystatin is estimated to be 10,700 by MALDI-TOF mass spectrometry, 11 300 by SDS-PAGE and 11,000 by gel filtration . It is a relatively strong inhibitor of papain with a Ki value of 0.21 nM and also inhibits ficin and bromelain but not cathepsin B . An amino acid sequence was obtained from a peptide produced by trypsin digestion of the inhibitor . Comparison with other plant sequences shows a high degree of homology with other phytocystatins . As the single cysteine proteinase inhibitor detectable in immature apple fruit (5-8 mm diameter), levels of 83.3 pmol/g FW were determined . In larger fruit (up to 16 mm diameter) significantly less inhibitor was present (6.9 pmol/g FW) . Given these low levels, it is postulated that this inhibitor has an endogenous role in apple fruit development rather than one of protection against pest or microbial attack. Int Arch Allergy Immunol, 1998 Oct, 117(2), 120 - 5 Neoallergens in heated soybean hull; Codina R et al.; BACKGROUND: During the process of harvest, transport and storage, microbial and mold contamination can raise the temperature of soybeans to 75 degreesC or higher . The purposes of this study were (1) to evaluate the allergenicity of fresh and stored soybean hulls and (2) to ascertain whether heat alters the allergenicity of stored soybean hulls . METHODS: Allergen extracts were prepared from (1) stored soybean hulls, (2) fresh soybean hulls and (3) stored soybean hulls heated to 37 degreesC (E1), 55 degreesC (E2) and 80 degreesC (E3) or kept at room temperature (E4) for 16 h . Individual serum from 68 soybean asthmatic (SA) subjects, 30 nonallergic subjects and two serum pools made from 4 SA sera and 4 sera from asthmatics not sensitive to soybean were studied . All sera and serum pools were assayed for content of specific IgE (radioallergosorbent test) and IgG4 (ELISA) . The following additional studies were done for extracts E1-E4: (1) SDS-PAGE, (2) SDS-PAGE/Western blot for specific IgE and IgG4 using both serum pools, and (3) study of the effects of heat on inhibiting activity of the extracts prepared from stored soybean hulls using the pool of SA sera . RESULTS: Test results demonstrated a reduced binding of specific IgE and IgG4 to fresh soybean hull extract compared to stored soybean hull extract, and an increased binding for heated extracts (E1-E3) compared to unheated ones (E4) . Moreover, there was an increase in potency for IgE and IgG4 bindings for the heated (E1-E3) compared to unheated (E4) extract, as measured by the amount of protein to produce 50% inhibition . Several protein bands with a molecular weight (MW) higher than 20 kD were absent from the SDS-PAGE for E3 but were present in E1, E2 and E4, and a new protein band (MW 15.3 kD) appeared for E3 only . Two new protein bands, with MWs of 15.3 and 10 kD, which bind specific IgE, were present on Western blot and one of the 3 main soybean hull allergens, probably Gly m 2, disappeared in E3 . IgG4 Western blot showed similar results, but only the 10 kD protein band was present . CONCLUSION: The results demonstrate that soybean hull allergenicity is affected by heat, and suggest that the heat generated during storage and transport of soybeans could generate 2 new allergen determinants or increases in epitope exposure as a result of conformational changes . The significance of these new IgE and IgG4 binding proteins has yet to be determined. J Dairy Sci, 1998 Sep, 81(9), 2394 - 407 Influence of processed corn grain in diets of dairy cows on digestion of nutrients and milk composition; Crocker LM et al.; Five primiparous Holstein cows (55 d in milk) that were fitted with ruminal and duodenal cannulas were used in a 4 x 5 incomplete Latin square to determine the effects of blends of steam-flaked and dry-rolled corn on site and extent of nutrient digestion and milk yield and composition . Diets were fed as total mixed rations and consisted of 45% forage and 55% concentrate; each diet contained 27% corn grain . Dietary treatments were composed of blends of dry-rolled and steam-flaked corn in ratios of 100:0, 67:33, 33:67, and 0:100 . Intake of dry matter; digestibilities of dry matter, organic matter, acid detergent fiber, cellulose, neutral detergent fiber, fatty acids, and N; and microbial efficiency were unaffected by diet . Ruminal, postruminal, and total tract digestion of starch increased linearly, and starch passage to the duodenum decreased linearly, as the proportion of dry-rolled corn in the diet decreased . Ruminal propionate and valerate increased linearly, and acetate, butyrate, isovalerate, and the acetate to propionate ratio decreased linearly, as proportions of dry-rolled corn in the diet decreased; however, no changes in total volatile fatty acid concentrations in ruminal fluid were observed . Ruminal fluid pH was similar across diets . A decrease in dry-rolled corn decreased ruminal ammonia N and plasma urea N linearly . Milk yield and composition, as well as milk N fractions, were similar across diets . Although changes in fatty acid composition of milk fat were small, linear decreases in percentages of trans-C16:1 and cis-9- and cis-10-C18:1, as well as a linear increase in the percentage of C18:2 occurred as the proportion of dry-rolled corn in the diet decreased . An increased proportion of dry-rolled corn in the diet decreased digestion of starch in the rumen, and patterns of volatile fatty acid concentrations shifted accordingly . However, no effects on lactational parameters were observed. Domest Anim Endocrinol, 1998 Sep, 15(5), 439 - 44 Cytokines as markers for infections and their effect on growth performance and well-being in the pig; Fossum C; Exposure to micro-organisms commonly elicit the production of cytokines . These soluble factors enhance several innate immune functions that aim to limit the spread of infection . Further, many of the pro-inflammatory cytokines regulate the ensuing specific immune response . In addition to their effects on cells of the immune system, cytokines also are important regulators in the so called immune-neuroendocrine network . The microbial structures that are necessary for induction of cytokine production are not conclusively determined but in general, bacteria preferentially induce the production of IL-1, TNF-alpha, IL-6, and IL-8, whereas virus induce the production of Type 1 interferons (IFN-alpha/beta) . The onset of production of these cytokines is rapid, and several of them may reach systemic levels during a short period after infection . Thus, cytokines can serve as markers for ongoing infections and be used for discrimination between infections of bacterial or viral origin . Results from experimental and field studies show that serum IFN-alpha and IL-6 seem to be useful markers for ongoing (subclinical) viral and bacterial infections, respectively, in the pig . Consequently, demonstration of these cytokines can be valuable tools in heard health monitoring programs. Anal Chem, 1998 Oct 1, 70(19), 4140 - 5 Biosensor for direct determination of organophosphate nerve agents using recombinant Escherichia coli with surface-expressed organophosphorus hydrolase . 1 . Potentiometric microbial electrode; Mulchandani A et al.; A potentiometric microbial biosensor for the direct measurement of organophosphate (OP) nerve agents was developed by modifying a pH electrode with an immobilized layer of Escherichia coli cells expressing organophosphorus hydrolase (OPH) on the cell surface . OPH catalyzes the hydrolysis of organophosporus pesticides to release protons, the concentration of which is proportional to the amount of hydrolyzed substrate . The sensor signal and response time were optimized with respect to the buffer pH, ionic concentration of buffer, temperature, and weight of cells immobilized using paraoxon as substrate . The best sensitivity and response time were obtained using a sensor constructed with 2.5 mg of cells and operating in pH 8.5, 1 mM HEPES buffer . Using these conditions, the biosensor was used to measure as low as 2 microM of paraoxon, methyl parathion, and diazinon . The biosensor had very good storage and multiple use stability . The use of cells with the metabolic enzyme expressed on cell surface as a biological transducer provides advantages of no resistances to mass transport of the analyte and product across the cell membrane and low cost due to elimination of enzyme purification, over the conventional microbial biosensors based on cells expressing enzyme intracellularly and enzyme-based sensors, respectively. Infect Immun, 1998 Nov, 66(11), 5157 - 66 Helicobacter hepaticus triggers colitis in specific-pathogen-free interleukin-10 (IL-10)-deficient mice through an IL-12- and gamma interferon-dependent mechanism; Kullberg MC et al.; Mice rendered deficient in interleukin-10 (IL-10) by gene targeting (IL-10(-/-) mice) develop chronic enterocolitis resembling human inflammatory bowel disease (IBD) when maintained in conventional animal facilities . However, they display a minimal and delayed intestinal inflammatory response when reared under specific-pathogen-free (SPF) conditions, suggesting the involvement of a microbial component in pathogenesis . We show here that experimental infection with a single bacterial agent, Helicobacter hepaticus, induces chronic colitis in SPF-reared IL-10(-/-) mice and that the disease is accompanied by a type 1 cytokine response (gamma interferon {IFN-gamma}, tumor necrosis factor alpha, and nitric oxide) detected by restimulation of spleen and mesenteric lymph node cells with a soluble H . hepaticus antigen (Ag) preparation . In contrast, wild-type (WT) animals infected with the same bacteria did not develop disease and produced IL-10 as the dominant cytokine in response to Helicobacter Ag . Strong H . hepaticus-reactive antibody responses as measured by Ag-specific total immunoglobulin G (IgG), IgG1, IgG2a, IgG2b, IgG3, and IgA were observed in both WT and IL-10(-/-) mice . In vivo neutralization of IFN-gamma or IL-12 resulted in a significant reduction of intestinal inflammation in H . hepaticus-infected IL-10(-/-) mice, suggesting an important role for these cytokines in the development of colitis in the model . Taken together, these microbial reconstitution experiments formally establish that a defined bacterial agent can serve as the immunological target in the development of large bowel inflammation in IL-10(-/-) mice and argue that in nonimmunocompromised hosts IL-10 stimulated in response to intestinal flora is important in preventing IBD. J Invertebr Pathol, 1998 Nov, 72(3), 246 - 51 Modeling and biological implication of time-dose-mortality data for the entomophthoralean fungus, zoophthora anhuiensis, on the green peach aphid myzus persicae Feng MG, Liu CL, Xu JH, Xu Q. The entomophthoralean fungus Zoophthora anhuiensis frequently causes epizootics in populations of the green peach aphid, Myzus persicae, infesting cruciferous crops in the middle and lower regions of the Changjiang River, China, during late autumn and early winter . In this study, a bioassay was conducted by exposing aphids on detached leaves to varying doses of Z . anhuiensis conidia discharged from in vitro cultures . Ten doses (1.5-198 conidia/mm2) were used, with each dose including 64-120 aphids . The aphids were maintained at 18 degreesC under a photophase of 12:12 (L:D) and observed daily for mortality . The resulting time-dose-mortality data fitted well to a conditional mortality probability model based on the Hosmer-Lemeshow test (C = 9.52, df = 8, P = 0.70), resulting in a cumulative mortality probability model . The parameters from the latter model were used to estimate the lethal dose (LD50) and time (LT50) for the fungal species against the pest . The LD50 values were 87, 44, and 34 conidia/mm2 on days 5, 6, and 7 after exposure, respectively . The estimates of the LT50 values decreased from 6.7 days at 37 conidia/mm2 to 4.5 days at 198 conidia/mm2 . The results indicate that Z . anhuiensis could be a promising aphid pathogen for microbial control competitive with other Zoophthora species . The model is recommended for use in the analysis of time-dose-mortality data for fungus-insect associations . The biological implications of the parameters and the advantages of the modeling technique over the conventional method of probit analysis are discussed . J Interferon Cytokine Res, 1998 Sep, 18(9), 697 - 703 Differential induction of IL-12 by IFN-beta and IFN-gamma in human macrophages; Jiang H et al.; Interleukin-12 (IL-12) is a proinflammatory cytokine secreted by antigen-presenting cells (APC) in response to microbial antigens and mitogens . IL-12 induces interferon-gamma (IFN-gamma) production and enhances cellular immune responses . Conversely, IFN-gamma does not induce IL-12 but can prime its production by phagocytic cells in response to antigenic stimuli . In this study, we examined the effect of IFN-beta on IL-12 production in human macrophages, as IFN-beta is a natural protein produced by virus-infected cells . We demonstrate that, unlike IFN-gamma, IFN-beta is able to induce IL-12 production in macrophages . However, IFN-gamma can enhance IFN-beta-induced IL-12 in these cells . These findings suggest that IFN-beta could influence the immune response to virus infection indirectly through IL-12. J Anim Sci, 1998 Sep, 76(9), 2239 - 46 Influence of tempering on the feeding value of rolled corn in finishing diets for feedlot cattle; Zinn RA et al.; Crossbred yearling steers (n = 125; 372 kg) were used in a 109-d finishing trial . Steers were fed an 88% concentrate diet containing 65% corn (DM basis) as 1) dry rolled corn (DRC); 2) tempered rolled corn (TRC), 43 mg surfactant (SarTemp)/kg corn; 3) TRC, 172 mg surfactant/kg corn; 4) TRC, 430 mg surfactant/kg corn; and 5) steam-flaked corn (SFC) . Corn moisture was greater (3.5%, P < .01) for TRC than for DRC but less (10%, P < .05) than for SFC . Starch enzymatic reactivity was less for TRC than for either DRC (18%, P < .05) or SFC (42%, P < .01) . Tempering increased the integrity of rolled corn and reduced the amount of particles less than 2 mm in diameter by 54% (P < .01) . Steam flaking corn increased (P < .01) proportion (78%) of the grain having a particle size distribution of greater than 8 mm, as compared with TRC (25%) and DRC (3%) . Compared with DRC, tempering enhanced (P < .10) ADG (9%), feed efficiency (5%), and dietary NE (3%) . Daily weight gain was similar (P > .10) for TRC and SFC . Feed efficiency (P < .10) and dietary NE (P < .01) were greater (6%) for SFC than for TRC . There were no differences (P > .10) between DRC and TRC in ruminal and total tract digestion of OM, N, and starch, and in ruminal microbial efficiency . Ruminal digestion of OM decreased (linear effect, P < .05) and ruminal microbial efficiency increased (linear effect, P < .05) with increasing surfactant concentration . Ruminal digestion of OM and starch, and flow of nonammonia N to the small intestine were greater (31, 56, and 14%, respectively, P < .01) for SFC than for TRC . Postruminal and total tract digestion of OM, N, and starch, and dietary DE were greater (P < .01) for SFC than for TRC . We concluded that tempering corn will enhance animal performance . Increasing the concentration of surfactant used in tempering may enhance ruminal microbial efficiency and lean tissue growth. J Immunol, 1998 Oct 15, 161(8), 3890 - 5 Effects of bacterial DNA on cytokine production by (NZB/NZW)F1 mice; Gilkeson GS et al.; Microbial DNA has multiple immune effects including the capacity to induce polyclonal B cell activation and cytokine production in normal mice . We recently described the accelerated induction of anti-DNA Abs in NZB/NZW mice immunized with Escherichia coli (EC) dsDNA; paradoxically these mice developed less renal disease than unimmunized mice or mice immunized with calf thymus DNA . We postulated that alterations in cytokine production induced by bacterial DNA may play a key role in renal protection . To determine the effect of bacterial DNA on cytokine production in NZB/NZW mice, we measured the serum cytokine levels, cell culture supernatant cytokine levels, and number of cytokine-producing splenocytes in NZB/NZW mice injected with EC DNA, calf thymus DNA, or an immune active oligonucleotide . There was a 10- to 25-fold increase in the number of cells secreting IFN-gamma compared with IL-4 in mice immunized with EC DNA . IL-12-secreting cells were also increased by bacterial DNA immunization . In parallel with the increase in IFN-gamma secreting cells, there was a significant rise in serum IFN-gamma levels in mice receiving EC DNA . These results indicate that EC DNA modulates systemic cytokine levels in NZB/NZW mice, selectively increasing IL-12 and IFN-gamma while decreasing IL-4 production . The cytokine response of NZB/NZW mice to bacterial DNA may be of significance in disease pathogenesis and relevant to the treatment of lupus-like disease. Syst Appl Microbiol, 1998 Aug, 21(3), 442 - 9 The use of biologically produced ferrihydrite for the isolation of novel iron-reducing bacteria; Straub KL et al.; Ferric iron was produced anaerobically from ferrous iron through the metabolic activity of recently described ferrous iron-oxidizing, nitrate-reducing bacteria . It was identified as poorly crystallized 2-line ferrihydrite with a particle size of 1-2 nm . This biologically produced ferrihydrite was shown to be a suitable electron acceptor for dissimilatory ferric iron-reducing bacteria in freshwater enrichment cultures, and was completely reduced to the ferrous state; no magnetite formation occurred . Geobacter metallireducens was also able to completely reduce the biologically produced ferrihydrite . These results indicate the possibility of an anaerobic, microbial cycling of iron . Using the biologically produced ferric iron, two isolates of obligately anaerobic, dissimilatory ferric iron-reducing bacteria, strains Dfr1 and Dfr2, were obtained from freshwater enrichment cultures . Analysis of 16S rRNA gene sequences revealed an affiliation with the Geobacter cluster within the family Geobacteraceae . The sequence similarity between strains Dfr1 and Dfr2 is 92.5% . The closest relative of strain Dfr1 is Geobacter sulfurreducens with 92.9%, and of strain Dfr2 Geobacter chapelleii with 93.7% sequence similarity . In addition, strains Dfr1 and Dfr2 are both able to grow by dissimilatory reduction of Mn(IV), S degree, and fumarate . Furthermore, strain Dfr2 is able to reduce akaganeite (beta-FeOOH), a more crystallized type of ferric iron oxide. Appl Biochem Biotechnol, 1998 May-Jun, 73(2-3), 243 - 56 Microbial sensor for new-generation cephalosporins based in a protein-engineered beta-lactamase; Garcia JL et al.; A protein-engineered beta-lactamase, constructed by site-directed mutagenesis in Escherichia coli (E104M/G238S), and having broadened specificity, was able to degrade cephalosporins of first, second, and third generations . Manipulations of culture conditions allowed an increase in beta-lactamase specific activity by up to twofold . The resultant bacteria were used to construct an immersable whole-cell biosensor for the detection of new-generation cephalosporins . Cells were immobilized on agar membranes, which in turn were attached to the surface of a flat pH electrode, thus constituting a biosensor based on the detection of pH changes . The sensor was able to detect second- and third-generation cephalosporins: cefamandole (0.4-4 mM), cefotaxime (0.4-3.5 mM), and cefoperazone (0.3-1.85 mM) . Response times were between 3.5 and 11 min, depending on the kind of cephalosporin tested . The biosensor was stable for at least 7 d, time during which up to 100 tests were performed. Rev Med Chil, 1998 Jun, 126(6), 702 - 14 {Laboratory diagnosis of Lyme borreliosis}; Gutierrez J et al.; Some direct methods that can be used for the diagnosis of Lyme borreliosis are the culture, direct visualization or the detection of microbial DNA using polymerase chain reactions, in body tissues or fluids . Unfortunately, all these methods have a low sensitivity . There is a wide assortment of tests and antigens for indirect diagnosis, and the most recommended are ELISA tests and Western blot . The main inconvenient of these tests are the existence of shared serologic reactions, the variability of immune response and the difficult interpretation of results . Therefore, we propose the following guidelines for the diagnosis of Lyme borreliosis: For sero-epidemiological studies and to diagnose infection, antibodies should be determined in subjects with a compatible clinical picture, using an ELISA test that must be positive in at least two separate samples . All positive ELISA results should be confirmed with Western blot analysis, that must be interpreted using established criteria . Polymerase chain reactions should be used when they are available. Orig Life Evol Biosph, 1998 Oct, 28(4-6), 475 - 83 Biomarkers as tracers for life on early earth and Mars; Simoneit BR et al.; Biomarkers in geological samples are products derived from biochemical (natural product) precursors by reductive and oxidative processes (e.g., cholestanes from cholesterol) . Generally, lipids, pigments and biomembranes are preserved best over longer geological times and labile compounds such as amino acids, sugars, etc . are useful biomarkers for recent times . Thus, the detailed characterization of biomarker compositions permits the assessment of the major contributing species of extinct and/or extant life . In the case of the early Earth, work has progressed to elucidate molecular structure and carbon isotropic signals preserved in ancient sedimentary rocks . In addition, the combination of bacterial biochemistry with the organic geochemistry of contemporary and ancient hydrothermal ecosystems permits the modeling of the nature, behavior and preservation potential of primitive microbial communities . This approach uses combined molecular and isotopic analyses to characterize lipids produced by cultured bacteria (representative of ancient strains) and to test a variety of culture conditions which affect their biosynthesis . On considering Mars, the biomarkers from lipids and biopolymers would be expected to be preserved best if life flourished there during its early history (3.5-4 x 10(9) yr ago) . Both oxidized and reduced products would be expected . This is based on the inferred occurrence of hydrothermal activity during that time with the concomitant preservation of biochemically-derived organic matter . Both known biomarkers (i.e., as elucidated for early terrestrial samples and for primitive terrestrial microbiota) and novel, potentially unknown compounds should be characterized. J Periodontol, 1998 Sep, 69(9), 1076 - 80 Acceptance Program Guidelines . Chemotherapeutic agents to slow or arrest periodontitis . Council on Scientific Affairs . American Dental Association; Constructing multigenome views of whole microbial genomes; Mathematics and Computer Science Division, Argonne National Labortory, Illinois, USAWe have designed and implemented a system to carry out cross-genome comparisons of open reading frames (ORFs) from multiple genomes . This implementation includes a genome profiling system that allows us to explore pairwise comparisons at different levels of match similarity and ask biologically motivated queries involving number and identity of ORFs, their function, functional category, distribution in genomes or in biological domains, and statistics on their matches and match families . This analysis required precise definition of new classification terms and concepts . We define the terms genomic signature, summary signature, biologic domain signature, domain class, match level, match family, and extended match family, then use these terms to define concepts, including genomically universal proteins and proteins characteristics of sets of genomes . We initiate an analysis based on automated FASTA (Pearson, 1996) comparison of 22,419 conceptually translated protein sequences from nine microbial genomes. Rev Med Interne, 1998 Jun, 19(6), 431 - 3 {Geotrichum capitatum infection in a neutropenic patient . Apropos of a case and review of the literature}; Fouassier M et al.; INTRODUCTION: Geotrichum capitatum sepsis are rare, occurring exclusively in immunocompromised patients . EXEGESIS: We report the case of a patient with acute leukemia, presenting with chemotherapy-induced neutropenia and hospitalized in an intensive care unit for a severe sepsis . In spite of an antibiotic and antifungal treatment, the patient died of cardiorespiratory failure . Later on, blood cultures proved to be positive for Geotrichum capitatum . CONCLUSION: If fungal infections are common in neutropenic patients, Geotrichum capitatum sepsis remain exceptional . The portal of entry is digestive or respiratory, and the invasion is favored by immunodepression and suppression of the normal microbial flora . Induced lesions can be multiorganic . The treatment is not well established, and the association of either amphotericine B and 5-fluorocytosine or amphotericine B and itraconazole would lead to better results . Nevertheless, the prognosis is still unfavorable, with a mortality rate of approximately 75%. Biochim Biophys Acta, 1998 Oct 14, 1388(1), 279 - 83 Cloning of cDNAs encoding new peptides of the dermaseptin-family; Wechselberger C; Dermaseptins are a group of basic (lysine-rich) peptides, 27-34 amino acids in length and involved in the defense of frog skin against microbial invasion . By using a degenerated oligonucleotide primer binding to the 5'-untranslated region of previously characterized cDNAs of these peptides, it was possible to identify new members of the dermaseptin family in the South American frogs Agalychnis annae and Pachymedusa dacnicolor . Amino acid alignment and secondary structure prediction reveals, that only five of the deduced peptides can be supposed to be also functional homologs to the known dermaseptins from Phyllomedusa bicolor and Phyllomedusa sauvagei . The remaining six peptides described in this paper have not been isolated and characterized yet. J Chir (Paris), 1997 Dec, 134(7-8), 296 - 300 {Microbial overgrowth syndrome after gastrectomy . Recent diagnostic aspects}; Baranger B et al.; Blind loop syndrome is the most common syndrome of bacterial overgrowth following gastrectomy . We report two cases with diarrhea, steatorrhea, exudative enteropathy and major nutritional deficiency . Diagnosis was based on the breath test and aspirate analysis . Surgery with restoration of the duodenal continuity was the treatment . Patients with contraindications for surgery should be given prolonged antibiotic therapy which should be repeated if symptoms reoccur. J Biotechnol, 1998 Aug 12, 63(2), 155 - 66 Rapid and highly automated determination of adenine and pyridine nucleotides in extracts of Saccharomyces cerevisiae using a micro robotic sample preparation-HPLC system; Mailinger W et al.; An ion-pair reversed-phase chromatography method was adapted for the simultaneous separation and quantification of adenine and pyridine nucleotide concentrations in cell extracts of Saccharomyces cerevisiae . Microbial extracts including metabolites, macromolecular constituents and inorganic compounds were loaded onto a ODS pre-column in the presence of triethylamine phosphate (TEA-Pi) resulting in a selective binding of the nucleotides and removing of interfering compounds . After washing the enrichment cartridge with 30 mM TEA-Pi buffer, adenine and pyridine nucleotides were eluted with a gradient of Mg(II), the competing hetaeron . This combined cleaning and concentration step leads to remarkable improvement of the detection limit for all nucleotides of interest and column lifetimes . The clean up and separation procedures were performed automatically with a micro robotic-system and a control software package written in PASCAL . The paper reports about the application of the proposed method to separation of adenine and pyridine nucleotides in cells extracts of S . cerevisiae grown anaerobically in a continuous culture (D = 0.1 h-1) . Rapidity of analysis, high sensitivity as well as reproducibility of the system and the accurate evaluation of the adenine and pyridine nucleotide concentrations make this method particularly useful for routine analysis. J AOAC Int, 1998 Sep-Oct, 81(5), 963 - 72 A screening method for beta-lactams in tissues hydrolyzed with penicillinase I and lactamase II; Medina MB et al.; Antibiotic residues above tolerance levels are not allowed in foods derived from farm animals . Microbial inhibition assays are used to screen antibiotics in U.S . regulatory laboratories . We developed a screening approach to classify beta-lactams through selective hydrolysis of the beta-lactam ring with Penase or lactamase II, thereby inactivating the beta-lactam activity . Optimum conditions for hydrolysis of beta-lactams with Penase and lactamase II were determined . beta-Lactams were detected by a microbial inhibition assay and with enzyme-linked immunosorbent assays before and after hydrolysis . beta-Lactams (10-100 ppb) were spiked in kidney extracts and hydrolyzed . Results indicate a pattern that tentatively classified the beta-lactams into 3 subgroups . Desfuroyl-ceftiofur-cysteine, a major metabolite of ceftiofur, was clearly detected . Penicillin G, ampicillin, amoxicillin, and cloxacillin were distinguishable from cephapirin, ceftiofur metabolite, and high levels of hetacillin . Liver and kidney tissue samples were analyzed with the combined enzyme hydrolysis and screening assays, which tentatively identified the residues . This approach can speed up screening analysis of beta-lactam residues prior to identification and quantitation by chromatographic analysis, thus enhancing positive identification of residues to provide a safer food supply. Proc Natl Acad Sci U S A, 1998 Oct 13, 95(21), 12111 - 6 A gene cluster for macrolide antibiotic biosynthesis in Streptomyces venezuelae: architecture of metabolic diversity; Xue Y et al.; In a survey of microbial systems capable of generating unusual metabolite structural variability, Streptomyces venezuelae ATCC 15439 is notable in its ability to produce two distinct groups of macrolide antibiotics . Methymycin and neomethymycin are derived from the 12-membered ring macrolactone 10-deoxymethynolide, whereas narbomycin and pikromycin are derived from the 14-membered ring macrolactone, narbonolide . This report describes the cloning and characterization of the biosynthetic gene cluster for these antibiotics . Central to the cluster is a polyketide synthase locus (pikA) that encodes a six-module system comprised of four multifunctional proteins, in addition to a type II thioesterase (TEII) . Immediately downstream is a set of genes for desosamine biosynthesis (des) and macrolide ring hydroxylation . The study suggests that Pik TEII plays a role in forming a metabolic branch through which polyketides of different chain length are generated, and the glycosyl transferase (encoded by desVII) has the ability to catalyze glycosylation of both the 12- and 14-membered ring macrolactones . Moreover, the pikC-encoded P450 hydroxylase provides yet another layer of structural variability by introducing regiochemical diversity into the macrolide ring systems . The data support the notion that the architecture of the pik gene cluster as well as the unusual substrate specificity of particular enzymes contributes to its ability to generate four macrolide antibiotics. Cell Biol Int, 1997 Nov, 21(11), 697 - 706 Mapping cell wall polysaccharides of living microbial cells using atomic force microscopy; Gad M et al.; Functionalized atomic force microscope tips were used to sense specific forces of interaction between ligand-receptor pairs and to map the positions of polysaccharides on a living microbial cell surface . Gold-coated tips were functionalized with concanavalin A using a cross-linker with a spacer arm of 15.6 A . It was possible to measure the binding force between concanavalin A and mannan polymers on the yeast (Saccharomyces cerevisiae) cell surface . This force ranged from 75 to 200 pN . The shape of the force curve indicated that the polymers were pulled away from the cell surface for a fairly long distance that sometimes reached several hundred nanometres . The distribution of mannan on the cell surface was mapped by carrying out the force measurement in the force volume mode of atomic force microscopy (AFM) . During the measurement, the maximum cantilever deflection after contact between the tip and the sample was kept constant at 10 nm using trigger mode to keep the pressing force on the sample surface as gently as possible at a force of 180 pN . This regime was used to minimize the non-specific adhesion between the tip and the cell surface . Specific molecular recognition events took place on specific areas of the cell surface that could be interpreted as reflecting a non-uniform distribution of mannan on the cell surface. Rev Cubana Med Trop, 1992, 44(3), 226 - 7 {Applying an ultramicroanalytical system to the diagnosis of infectious diseases}; Rivas Arjona MI et al.; The multiple applications and advantages of the ultramicro analytical system in the serodiagnosis of different diseases produced by viruses, bacteria, and parasites are briefly reported . Also, perspectives in the use of this technology, not only for the diagnosis, but for the detection of microbial antigens are pointed out. J Microsc, 1998 Sep, 191(3), 311 - 319 X-ray microanalysis of native airway surface liquid collected by cryotechnique; Baconnais S et al.; The airway surface liquid (ASL) that lines the surface epithelium of the tracheobronchial tree is of vital importance to the airway defence against microbial invasion and damage due to environmental factors . Little is known about the ASL collected in situ in native conditions, owing to difficulties in collecting ASL without causing damage to the airway mucosa . We have developed a method to collect and analyse the elemental composition of tracheal ASL in pathogen-free mice . A specially designed cryoprobe, adapted to the internal curvature of the mouse trachea, was used to collect the native ASL from the tracheal surface . The complete ASL elemental composition including {Na} = 5.5 +/- 0.3, {Cl} = 1.3 +/- 0.3, {K} = 1.1 +/- 0.2, {Ca} = 1.2 +/- 0.3, {P} = 1.5 +/- 0.8, {S} = 1.7 +/- 0.4 and {Mg} = 1.3 +/- 0.4 mmol L-1 was determined by X-ray micro analysis . We demonstrate here that the technique that we used for ASL collection maintained perfectly the airway epithelial integrity and functionality. J Food Prot, 1998 Sep, 61(9), 1216 - 28 A general framework illustrating an approach to quantitative microbial food safety risk assessment; McNab WB; Hazard analysis critical control point (HACCP), risk assessment, predictive microbiology, and dose-response modeling have been recognized as important tools for the assessment and management of health risks posed by food-borne pathogens . Unfortunately, the biology of both the food chain and food poisoning is complex and dynamic . Therefore, mathematical modeling of microbial risk from food production through to consumption and illness is difficult . Nevertheless, previous authors have made impressive progress in modeling specific pathogen-food-consumer combinations . In this study a framework for a Monte Carlo model of a generic food system was developed . It links together food ingredients, batch processing, cross contamination, microbial growth, cooking, recontamination, consumption, human exposure to pathogens, the dose-response relationship, and the biologic and economic impact components of such risks . This framework is presented to illustrate one potential approach to quantitative risk assessment for microbial food safety . It requires refinement with appropriate distributions and mathematical relationships before it can be applied to a specific pathogen-food-consumer situation. Viral Immunol, 1998, 11(2), 65 - 72 Effect of plasmid DNA on immunogenicity of HBsAg-anti-HBs complex; Qu D et al.; Hepatitis B surface antigen (HBsAg) complexed with anti-HBs is more immunogenic than HBsAg alone in mice . This complex is usually used with alum as an adjuvant, which can enhance humoral response but inhibits cell-mediated immune responses . To improve the immunogenicity of HBsAg-anti-HBs, we immunized mice with a combination of this immunogenic complex and pCMVHBs, a plasmid encoding HBsAg, or the vector pCMV . Both plasmids enhanced the anti-HBs response induced by the immunogenic complex . We found 20 microg of plasmid or vector enhanced the anti-HBs response in all mice, whereas 1 microg was less effective . Splenocytes from different immunized groups were stimulated with HBsAg in vitro, and the highest level of IL-2 detected in the supernatant was found in mice immunized with HBsAg-anti-HBs plus pCMVHBs . A plasmid (pcDNA3c191) encoding core protein of hepatitis C virus (HCV) was used as an adjuvant to the immunogenic complex . A preliminary result showed that pcDNA3c191 not only enhanced the immunogenicity of HBsAg-anti-HBs, but also induced anti-HCV core antibodies . Immunization using a plasmid DNA encoding one viral antigen in combination with antigen and antibody complex of another microbial origin could be a new approach to the development of multivalent vaccines. Semin Respir Infect, 1998 Sep, 13(3), 184 - 96 Cytokines in sarcoidosis; Agostini C et al.; Although the cause of sarcoidosis is still unknown, the combination of the characteristic morphologic aspect and the immunohistologic pattern of the sarcoid granulomatous lesions suggest that they are the result of an antigen-driven process . In particular, sarcoid granuloma is considered to be the consequence of an exaggerated immunological response against an undefined antigen which has persisted at the sites of disease involvement . Taking advantage of the availability of pure recombinant cytokines and molecular probes for cytokines and their receptors, in the last few years it has been possible to keenly study the involvement of several cytokines in the pathologic changes associated with sarcoidosis . The purpose of this review is to summarize the interactions between cytokines and their receptors which define regulatory networks ultimately contributing to the sarcoid granuloma formation at sites of disease activity . After a concise overview of the main cytokines involved in the sarcoid inflammatory response, we will briefly discuss the biological effects of Th1 and Th2 cytokines in sarcoid lung and then concentrate on the importance of the local production of those molecules whose release has been recently shown within the lung of patients with sarcoidosis, such as interleukin-12, interleukin-15, and chemokines . Furthermore, we will focus the discussion on the cytokines which, pivotal to the activation of the host defenses, may contribute to lung damage and the consequent lung fibrosis . The final section of this article reviews the lung release of cytokines in the context of recent hypotheses claiming microbial pathogens as putative causative agents of sarcoidosis. J R Coll Physicians Lond, 1998 Jul-Aug, 32(4), 328 - 32 Community acquired pneumonia; Finch R; CAP affects all ages but predominantly the elderly . The microbial aetiology is diverse and rarely established at the time of admission . Initial management includes assessment of severity, correction of dehydration and imbalances of gas exchange, and prompt administration of antibiotic . The regimens will vary by risk factor and severity assessment . Mortality remains high, especially in those requiring intensive care . Prevention includes control of underlying disease, smoking and ethanol abuse, and the appropriate use of influenza and pneumococcal vaccines. Int J Food Microbiol, 1998 Aug 18, 43(1-2), 39 - 52 A novel modelling approach for predicting microbial growth in a raw cured meat product stored at 3 degrees C and at 12 degrees C in air; Aggelis G et al.; To predict microbial growth during chill storage of a traditional Greek raw sausage, a numerical model was developed and validated . In our novel approach, the specific growth rate of each microbial population was calculated on the basis of the main microbial populations grown in the sausage . In addition, the specific destructive effect of the sausage ecosystem was introduced to evaluate microbial growth . The model was integrated by the Runge-Kutta method and the parameter values were optimised by the least squares method . Fitting of the model to the experimental data derived from four sausage batches stored aerobically at 3 and 12 degrees C successfully described the microbial growth kinetics in the sausage niche . Finally, the parameter values estimated by the fitting of the model on the data set from each batch were used to predict microbial growth in the other batches at both storage temperatures. Protein Sci, 1998 Sep, 7(9), 2033 - 7 Characterization of recombinant human cathepsin B expressed at high levels in baculovirus; Steed PM et al.; The lysosomal cysteine protease cathepsin B has been studied intensely for many years because of its unique characteristics and its potential involvement in disease states . A reproducible, high yield expression system for active recombinant protein is key to biochemical and biophysical studies as well as rational drug design . Although several microbial and mammalian expression systems for recombinant human cathepsin B have been described, these have been limited by low or variable yields . Further, in some of these systems hyper-glycosylation of the enzyme near the active site affects its activity . We describe a baculovirus expression system and purification scheme that solve all of these problems . Yields of active, protected enzyme were reproducibly in excess of 25 mg/L . Since this protein was not hyper-glycosylated, it had greater activity than cathepsin B produced in yeast systems as indicated by a threefold increase in Kcat . In addition, the biophysical properties of the baculovirus-expressed cathepsin B, as measured by dynamic light scattering, were more amenable to crystallographic study since the data indicated proteins of more uniform size . Therefore, this system for the production of recombinant human cathepsin B constitutes a major improvement in both quantity and quality over those previously reported . Further, we demonstrate that the manner of expression and purification of this enzyme has profound effects on its kinetic and physical parameters. Int J Food Microbiol, 1998 Aug 18, 43(1-2), 97 - 104 Relation between the generation time and the lag time of bacterial growth kinetics; Delignette-Muller ML; In predictive microbiology, the relation between the lag time (Lag) and the generation time (Tg) is commonly assumed to be proportional, as long as the pre-incubation environmental conditions remain constant . This relation was statistically examined in nine published datasets . For every dataset, it was roughly proportional . However, a more advanced study showed that the ratio Lag/Tg was not totally independent of the environmental conditions . In particular, a significant negative effect of the pH on this ratio was observed in five of the nine datasets . For modeling the environmental dependence of microbial growth parameters, some authors independently deal with Lag and Tg . Other authors only model the environmental dependence of Tg, assuming Lag/Tg to be constant . These two modeling methods were statistically compared for the nine datasets under study . Results differed from one dataset to another . For some, the model developed with a constant ratio Lag/Tg sufficed to describe the data, whereas for the others, an independent modeling of Lag and Tg was more satisfactory. Cell Mol Life Sci, 1998 Aug, 54(8), 833 - 50 Bacterial nonspecific acid phosphohydrolases: physiology, evolution and use as tools in microbial biotechnology; Rossolini GM et al.; Bacterial nonspecific acid phosphohydrolases (NSAPs) are secreted enzymes, produced as soluble periplasmic proteins or as membrane-bound lipoproteins, that are usually able to dephosphorylate a broad array of structurally unrelated substrates and exhibit optimal catalytic activity at acidic to neutral pH values . Bacterial NSAPs are monomeric or oligomeric proteins containing polypeptide components with an M(r) of 25-30 kDa . On the basis of amino acid sequence relatedness, three different molecular families of NSAPs can be distinguished, indicated as molecular class A, B and C, respectively . Members of each class share some common biophysical and functional features, but may also exhibit functional differences . NSAPs have been detected in several microbial taxa, and enzymes of different classes can be produced by the same bacterial species . Structural and phyletic relationships exist among the various bacterial NSAPs and some other bacterial and eucaryotic phosphohydrolases . Current knowledge on bacterial NSAPs is reviewed, together with analytical tools that may be useful for their characterization . An overview is also presented concerning the use of bacterial NSAPs in biotechnology. Appl Environ Microbiol, 1998 Oct, 64(10), 3838 - 45 Enzymatic activity, bacterial distribution, and organic matter composition in sediments of the ross sea (Antarctica) Fabiano M, Danovaro R. Enzymatic activities of aminopeptidase and beta-glucosidase were investigated in Antarctic Ross Sea sediments at two sites (sites B and C, 567 and 439 m deep, respectively) . The sites differed in trophic conditions related to organic matter (OM) composition and bacterial distribution . Carbohydrate concentrations at site B were about double those at site C, while protein and lipid levels were 10 times higher . Proteins were mainly found in a soluble fraction (>90%) . Chloropigment content was generally low and phaeopigments were almost absent, indicating the presence of reduced inputs of primary organic matter . ATP concentrations (as a measure of the living microbial biomass) were significantly higher at site B . By contrast, benthic bacterial densities at site C were about double those at site B . Bacterial parameters do not appear to be "bottom-up controlled" by the amount of available food but rather "top-down controlled" by meiofauna predatory pressure, which was significantly higher at site B . Aminopeptidase and beta-glucosidase extracellular enzyme activities (EEA) in Antarctic sediments appear to be high and comparable to those reported for temperate or Arctic sediments and characterized by low aminopeptidase/beta-glucosidase ratios (about 10) . Activity profiles showed decreasing patterns with increasing sediment depth, indicating vertical shifts in both availability and nutritional quality of degradable OM . Vertical profiles of aminopeptidase activity were related to a decrease in protein concentration and/or to an increase in the insoluble refractory proteinaceous fraction . The highest aminopeptidase activity rates were observed at site C, characterized by much lower protein concentrations . Differences in EEA between sites do not seem to be explained by differences in the in situ temperature (-1.6 and -0.8 degreesC at sites B and C, respectively) . Aminopeptidase activity profiles are consistent with the bacterial biomass and frequency of dividing cells . Enzyme substrate affinity was generally dependent upon substrate concentrations . EEA, normalized to bacterial numbers, indicated specific activities comparable to those reported for equally deep sediments at temperate latitudes . Vertical patterns of specific enzymatic activity appeared to be controlled by chloroplastic pigment concentrations that accumulate in the deeper sediment layers . The overall conclusion from the analysis of EEA in Antarctic sediments is that enzyme-dependent transformations of OM proceed at rates similar to those measured in temperate environments . Protein carbon potentially liberated by aminopeptidase activities (12.597 to 26.190 mg of C m-2 day-1) indicates that the whole protein pool could be mobilized within 1.3 to 17 h . Carbohydrate carbon mobilization (773 to 2,552 mg of C m-2 day-1) is sufficient to turn over the carbohydrate pool within 16 to 20 h . Such rates are 6 to 45 times higher than fluxes of particulate organic proteins and carbohydrates, indicating an "uncoupled hydrolysis" by the Antarctic benthic assemblages, in which bacteria appear to be able to rapidly exploit episodic OM pulses. J Immunol, 1998 Oct 1, 161(7), 3307 - 14 Expansion by self antigen is necessary for the induction of experimental autoimmune encephalomyelitis by T cells primed with a cross-reactive environmental antigen; Carrizosa AM et al.; Cross-reactivity with environmental antigens has been postulated as a mechanism responsible for the induction of autoimmune disease . Experimental autoimmune encephalomyelitis is a T cell-mediated autoimmune disease model inducible in susceptible strains of laboratory animals by immunization with protein constituents of myelin . We used myelin proteolipid protein (PLP) peptide 139-151 and its analogues to define motifs to search a protein database for structural homologues of PLP139-151 and identified five peptides derived from microbial Ags that elicit immune responses that cross-react with this self peptide . Exposure of naive SJL mice to the cross-reactive environmental peptides alone was insufficient to induce autoimmune disease even when animals were treated with Ag-nonspecific stimuli (superantigen or LPS) . However, immunization of SJL mice with suboptimal doses of PLP139-151 after priming with cross-reactive environmental peptides consistently induced experimental autoimmune encephalomyelitis . Furthermore, T cell lines from mice immunized with cross-reactive environmental peptides and restimulated in vitro with PLP139-151 could induce disease upon transfer into naive recipients . These data suggest that expansion by self Ag is required to break the threshold to autoimmune disease in animals primed with cross-reactive peptides. Appl Environ Microbiol, 1998 Oct, 64(10), 4084 - 8 Effective recovery of bacterial DNA and percent-guanine-plus-cytosine-based analysis of community structure in the gastrointestinal tract of broiler chickens; Apajalahti JH et al.; A DNA-based, direct method for initial characterization of the total bacterial community in ileum and cecum of the chicken gastrointestinal (GI) tract was developed . The efficiencies of bacterial extraction and lysis were >95 and >99%, respectively, and therefore the DNA recovered should accurately reflect the bacterial communities of the ileal and cecal digesta . Total bacterial DNA samples were fractionated according to their percent G+C content . The profiles reflecting the composition of the bacterial community were reproducible within each compartment, but different between the compartments of the GI tract . This approach is independent of the culturability of the bacteria in the consortium and can be used to improve our understanding of how diet and other variables modulate the microbial communities of the GI tracts of animals. Infect Control Hosp Epidemiol, 1998 Aug, 19(8), 565 - 9 Comparative and library epidemiological typing systems: outbreak investigations versus surveillance systems; Struelens MJ et al.; A number of high-resolution molecular typing systems have been developed in recent years . Their availability raises the new issues of selecting the method (s) best suited for a particular purpose and interpreting and communicating typing results . Most of the currently available methods are comparative only: they allow testing of a sample of isolates for delineation of those closely related from those markedly different in genomic backgrounds . This approach is adequate for outbreak investigation, allowing determination of clonal spread in a microenvironment and identification of the source of infection . Comparative methods with sufficient resolution for most pathogens include restriction fragment-length polymorphism (RFLP), pulsed-field gel electrophoresis (PFGE), and arbitrarily primed and randomly amplified polymorphic DNA-polymerase chain reaction (PCR) analysis . For surveillance systems, monitoring clonal spread and prevalence in populations over extended periods of time requires library typing systems . These must be standardized, must have a high throughput, and must use a uniform nomenclature . Promising or validated methods include serotyping, insertion sequence fingerprinting, ribotyping, PFGE, amplified fragment-length polymorphism (AFLP), infrequent-restriction-site amplification PCR, interrepetitive element PCR typing (rep-PCR) and PCR-RFLP of polymorphic loci . PCR methods generating arrays of size-specific amplicons (AFLP, rep-PCR) can be more reproducibly analyzed by using denaturing polyacrylamide gel or capillary electrophoresis with automated laser detection . Binary probe typing systems appear optimal and should be enhanced further through use of DNA chip technology . In these systems, amplification of polymorphic regions is followed by solid-phase hybridization with a reference panel of sequence-variant specific probes . The resulting binary type results allow determination of reproducible, numeric profiles . However, interpretation and nomenclature of typing results for large-scale surveillance purposes still require a better understanding of population structure and microevolution of most microbial pathogens. Biosci Biotechnol Biochem, 1998 Aug, 62(8), 1568 - 73 Synthesis and biological activities of (-)-6-n-octyl-indolactam-V, a new potent analogue of the tumor promoter (-)-indolactam-V; Nakagawa Y et al.; (-)-Indolactam-V (1) without a hydrophobic chain at positions 6 and 7 of the indole ring is a weak tumor promoter compared with teleocidin Bs . To investigate the effects of the hydrophobic substituent at position 6 of teleocidin Bs, we synthesized (-)-6-n-octyl-indolactam-V (2) by a palladium-catalyzed coupling reaction from (-)-6-bromo-indolactam-V (7) which had been obtained by microbial conversion with Streptoverticillium blastmyceticum NA34-17 as the key step . (-)-7-n-Octyl-indolactam-V (3) with potent biological activities comparable to those of teleocidin Bs was similarly synthesized from (-)-7-bromo-indolactam-V as a positive control . Compound 2 showed similar biological activities to those of 3, indicating that the effect of the hydrophobic substituent at position 6 of 1 was identical to that at position 7. Science, 1998 Oct 2, 282(5386), 80 - 3 Triploblastic animals more than 1 billion years ago: trace fossil evidence from india Seilacher A, Bose PK, Pfluger F. Some intriguing bedding plane features that were observed in the Mesoproterozoic Chorhat Sandstone are biological and can be interpreted as the burrows of wormlike undermat miners (that is, infaunal animals that excavated tunnels underneath microbial mats) . These burrows suggest that triploblastic animals existed more than a billion years ago . They also suggest that the diversification of animal designs proceeded very slowly before the appearance of organisms with hard skeletons, which was probably the key event in the Cambrian evolutionary explosion, and before the ecological changes that accompanied that event. J Clin Pharm Ther, 1998 Feb, 23(1), 41 - 7 Stability of cefazolin sodium eye drops; How TH et al.; OBJECTIVE: Assessing the stability of cefazolin sodium in preservative-free and preservative-containing eye drops . METHOD: Extemporaneous formulations of eye drops were prepared from a commercially-available parenteral product of cefazolin sodium: eye drops 'A' contained 50mg/ml of cefazolin sodium in 0.45% w/v sodium chloride solution, and eye drops 'B' contained 50 mg/ml, 0.005% w/v thiomersal and 1% w/v glycerol in water-for-injection . Cefazolin sodium concentrations in these eye drops were monitored by a stability-indicating HPLC assay method . Measurements of pH and osmolality, as well as tests for microbial contamination, were conducted . RESULTS: The eye drops stored at 4 degrees C were stable for 42 days with minimal changes in pH and osmolality, but eye drops stored at room temperature were only stable for a few days with greater increments in pH and osmolality . None of the samples cultured had bacterial or fungal growth after 7 days of incubation . CONCLUSION: Extemporaneously prepared formulations of cefazolin are unstable at room temperature and should be stored in a refrigerator. J Microsc, 1998 Sep, 191 ( Pt 3), 311 - 9 X-ray microanalysis of native airway surface liquid collected by cryotechnique; Baconnais S et al.; The airway surface liquid (ASL) that lines the surface epithelium of the tracheobronchial tree is of vital importance to the airway defence against microbial invasion and damage due to environmental factors . Little is known about the ASL collected in situ in native conditions, owing to difficulties in collecting ASL without causing damage to the airway mucosa . We have developed a method to collect and analyse the elemental composition of tracheal ASL in pathogen-free mice . A specially designed cryoprobe, adapted to the internal curvature of the mouse trachea, was used to collect the native ASL from the tracheal surface . The complete ASL elemental composition including {Na} = 5.5 +/- 0.3, {Cl} = 1.3 +/- 0.3, {K} = 1.1 +/- 0.2, {Ca} = 1.2 +/- 0.3, {P} = 1.5 +/- 0.8, {S} = 1.7 +/- 0.4 and {Mg} = 1.3 +/- 0.4 mmol L-1 was determined by X-ray micro-analysis . We demonstrate here that the technique that we used for ASL collection maintained perfectly the airway epithelial integrity and functionality. Hepatology, 1998 Oct, 28(4), 906 - 13 Cryptosporidium parvum is cytopathic for cultured human biliary epithelia via an apoptotic mechanism; Chen XM et al.; While the clinical features of sclerosing cholangitis secondary to opportunistic infections of the biliary tree in patients with acquired immunodeficiency syndrome (AIDS) are well known, the mechanisms by which microbial pathogens such as Cryptosporidium parvum associated with this syndrome actually cause disease are obscure . We established an in vitro model of biliary cryptosporidiosis employing a human biliary epithelial cell line . Using morphological and biochemical techniques, we examined the interaction of C . parvum with cultured human cholangiocytes . When the apical plasma membrane of polarized, confluent monolayers of human biliary epithelial cells was exposed to C . parvum oocysts that had been excysted in vitro, sporozoites attached to and invaded the cells in a time-, dose-, temperature-, and pH-dependent manner . The infectious process was both plasma membrane domain- and cell-specific, because no attachment or invasion occurred when the basolateral membrane of cholangiocytes was exposed to the parasite, or when a human hepatocyte cell line (HepG2) was used . Time-lapse video microscopy and scanning electron microscopy (SEM) showed that sporozoite attachment was rapid, involved extensive cholangiocyte membrane ruffling, and culminated in parasite penetration into a tight-fitting vacuole formed by invagination of the plasma membrane similar to those found in naturally occurring infection in vivo . Transmission electron microscopy (TEM) showed that C . parvum organisms formed parasitophorus vacuoles and were able to undergo a complete reproductive cycle, forming both asexual and sexual reproductive stages . Unexpectedly, direct cytopathic effects were noted in infected monolayers, with widespread programmed cell death (i.e., apoptosis) of biliary epithelial cells as assessed both morphologically and biochemically beginning within hours after exposure to the organism . The novel finding of specific cytopathic invasion of biliary epithelia by C . parvum may be relevant to the pathogenesis and possible therapy of the secondary sclerosing cholangitis seen in AIDS patients with biliary cryptosporidiosis. Biochim Biophys Acta, 1998 Oct 1, 1400(1-3), 213 - 22 Mutagenic properties of topoisomerase-targeted drugs; Baguley BC et al.; Topoisomerases maintain DNA structure by relieving torsional stress occurring in DNA during transcription, replication and cell division . Topoisomerases are of two main types, causing transient breaks in one (type I) or both (type II) and strands of DNA, and a number of clinical anticancer drugs are thought to act by inhibiting religation of these transient breaks . Topoisomerase II appears to have a close association with the SMC (stable maintenance of chromosomes) family of proteins involved in organisation of the chromatin in a series of loops on the proteinaceous chromosomal scaffold . Inhibition of topoisomerase II function can result in deletions of such loops, probably mediated by reciprocal exchange of topoisomerase subunits . Disruption of topoisomerase I and/or II function during DNA replication results in smaller DNA deletions and other mutations, probably arising from non-homologous recombination . Inhibition of topoisomerase II action during mitosis and meiosis can cause incomplete separation of chromatids and chromosomes, with the consequent production of genomic mutations . Topoisomerase-mediated mutagenicity is important because it can lead not only to drug resistance but also to drug-induced secondary cancers . Mutagenicity of topoisomerase-directed agents has been underestimated in the past, since these drugs are not usually capable of reacting covalently with DNA and usually have low mutagenicity in microbial assays. J Biomater Sci Polym Ed, 1998, 9(9), 931 - 42 A swine model for the evaluation of efficacy of anti-microbial catheter coatings; Gilbert JA et al.; A swine model was developed to investigate the efficacy of percutaneous venous catheters with anti-microbial coatings . The catheters used in the study consisted of silver-coated and uncoated catheters, both designed for percutaneous venous access . Five commercial pigs were each implanted with three venous catheters and followed for a period of 90 days . Two of the three catheters were coated and one was uncoated . To evaluate the percutaneous aspects of the catheters in the model, two venous access catheters were implanted percutaneously, parallel to the dorsal midline . These catheters were just caudal to the region that is dorsal to the scapula in each animal . In each case, the catheter to the left of the dorsal midline was silver-coated while the catheter to the right of the dorsal midline was uncoated . A silver-coated catheter was also implanted in the left external jugular vein of each animal and buried subcutaneously in order to evaluate the elution of the coating through the body under venous contact . Over the 90 day period, the concentration of silver in the blood rose to a mean peak level of 23.2 ppb following implantation of the catheters and then decreased after the second post-surgery week . The histological evaluation and macroscopic inspection at necropsy revealed minimal tissue response to both coated and uncoated materials . Data on bacterial growth indicated that bacteria were present at the terminal subcutaneous end of two of the uncoated percutaneous catheters . Based upon serum silver levels, exudate formation, histological examination, and bacterial growth information, the swine model was deemed to be suitable for testing the efficacy of catheters containing anti-microbial coatings. Chemosphere, 1998 Jun, 36(15), 3033 - 41 Aerobic microbial degradation of aromatic sulfur-containing compounds and effect of chemical structures; Zhang AQ et al.; Batch data of aerobic microbial degradation rate constants Kb of phenylthio, phenylsulfinyl and phenylsulfonyl acetates have been determined, and the qualitative relationships between their Kb and chemical structures were analyzed . The phenylthio acetates were most subject to microbial transformation, followed by the phenylsulfonyl acetates . The compounds with a methoxy group were easier degraded than those with a isopropoxy group . The nitro-group and chloro-group on benzene were shown to lower the biodegradability, while the nitro-group at the para-position had stronger side effect on degradation than at the ortho-position. Mol Cell Biochem, 1998 Aug, 185(1-2), 39 - 46 The inflammation modulatory protein (IMP) of cowpox virus drastically diminishes the tissue damage by down-regulating cellular infiltration resulting from complement activation; Kotwal GJ et al.; Vaccinia virus (VV) and other pathogenic poxviruses encode for a complement control protein . The VV complement control protein or VCP, was one of the first soluble microbial proteins postulated to have an active role in the immunomodulation of the host defense . Since then, 2 other poxviruses, including variola virus and cowpox virus (CPV), were found to have corresponding proteins . Based upon earlier studies which demonstrated the role of the CPV complement control protein in modulating the specific tissue responses in BALB/c and congenic-matched C5-sufficient and C5-deficient mice, the CPV equivalent has been renamed the inflammation modulatory protein (IMP), so as to specifically reflect its function . In this study, the in vivo cellular response of mice injected with CPV or a recombinant virus lacking the IMP sequence (CPV-IMP) was examined using a connective tissue air pouch model . Microscopic examination revealed that CPV-IMP caused a significant mononuclear cell infiltration into the connective tissue and adjacent dermal tissue of the skin . To characterize IMP's ability to regulate the observed cellular infiltration through both complement derived and non-complement derived chemotactic factors, footpad and skin connective tissue of C3 knockout mice and footpad of MIP-1alpha knockout mice received injections of CPV and CPV-IMP . In comparison to the matched control, significantly greater footpad specific swelling response was seen in C3 -/- mice injected with CPV . This indicates an important role for C3 in poxvirus pathogenesis . However, MIP-1 alpha -/- mice injected with CPV-IMP recovered earlier than mice injected with CPV alone . This indicates that the function of IMP in vivo in mice with a complete repertoire of immune components is to limit cellular infiltration by down regulating the complement derived chemotactic analphylotoxins, thereby modulating the inflammatory response contributing to a diminished tissue pathology and preservation of viral habitat. J Theor Biol, 1998 Aug 21, 193(4), 717 - 29 Biological effects of high ultraviolet radiation on early earth--a theoretical evaluation; Cockell CS; The surface of early Earth was exposed to both UVC radiation (< 280 nm) and higher doses of UVB (280-315 nm) compared with the surface of present day Earth . The degree to which this radiation environment acted as a selection pressure on organisms and biological systems has rarely been theoretically examined with respect to the biologically effective irradiances that ancient organisms would receive . Here action spectra for DNA inactivation and isolated chloroplast inhibition are used to estimate biologically effective irradiances on archean Earth . Comparisons are made with present day Earth . The theoretical estimations on the UV radiation screening required to protect DNA on archean Earth compare well with field and laboratory observations on protection strategies found in present day microbial communities . They suggest that many physical and biological methods may have been effective and would have allowed for the radiation of life even under the high UV radiation regimes of archean Earth . Such strategies would also have provided effective reduction of photoinhibition by UV radiation . The data also suggest that the UV regime on the surface of Mars is not a life limiting factor per se, although other environmental factors such as desiccation and low temperatures may contribute towards the apparent lack of a surface biota. Trends Biotechnol, 1998 Sep, 16(9), 396 - 403 Microbial lipases form versatile tools for biotechnology; Jaeger KE et al.; Lipases are secreted into the culture medium by many bacteria and fungi . They catalyse not only the hydrolysis but also the synthesis of long-chain acylglycerols . Important uses in biotechnology include their addition to detergents, the manufacture of food ingredients, pitch control in the pulp and paper industry, and biocatalysis of stereoselective transformations . This makes them the most widely used class of enzymes in organic chemistry . Immobilization in hydrophobic sol-gel matrices and in vitro evolution are promising novel approaches to increasing the stability or enantioselectivity, respectively, of lipases. Trends Biotechnol, 1998 Sep, 16(9), 390 - 5 Microbial denitrogenation of fossil fuels; Benedik MJ et al.; The microbial degradation of nitrogen compounds from fossil fuels is important because of the contribution these contaminants make to the formation of nitrogen oxides (NOx) and hence to air pollution and acid rain . They also contribute to catalyst poisoning during the refining of crude oil, thus reducing process yields . We review the current status of microbial degradation of aromatic nitrogen compounds and discuss the potential of microbial processes to alleviate these problems. Int J Biochem Cell Biol, 1998 Aug, 30(8), 857 - 62 The p21Rac/Cdc42-activated kinases (PAKs); Knaus UG et al.; The p21-activated kinases (PAKs) are mammalian Rac/Cdc42-associated serine/threonine protein kinases . They contain diverse structural regulatory elements that allow them not only to participate as effectors in signaling processes initiated by activated GTPases but also in signal transduction events mediated by Src3 homology domains (SH3) or caspase-mediated proteolytic cleavage . The biological functions of PAK protein kinases result from the interplay of N- and C-terminal-mediated protein-protein interactions and signals derived from phosphorylation of downstream substrates . The potential regulation of microbial killing, stress responses, apoptosis, and cell motility by PAKs suggest it may be a therapeutically useful target in a number of disease states. J Immunol, 1998 Sep 15, 161(6), 2994 - 3000 Inducible nitric oxide synthase is not required for long-term vaccine-based immunity against Toxoplasma gondii; Khan IA et al.; Induction of reactive nitrogen intermediates by IFN-gamma is presumed an important mechanism of host resistance against acute and chronic infection with Toxoplasma gondii . Although nitric oxide (NO) has been shown to be important in the control of parasite replication in vivo, the role of this molecule in vaccine-based immunity against T . gondii is unknown . Mice with a targeted disruption of inducible NO synthase (iNOS) were immunized with an avirulent temperature-sensitive strain of this parasite (ts-4) . Both the parental C57BL/6 and the iNOS(-/-) mice survived infection with the ts-4 mutant . Oral challenge of the vaccinated mice with a lethal dose of cysts containing bradyzoites resulted in reduced parasite burden and increased survival compared with nonvaccinated control mice . Host immunity in the iNOS(-/-) mice, similar to that observed in the parental strain, appears dependent upon both IFN-gamma and CD8+ T cells . These findings suggest that although vaccine-based long-term immunity against T . gondii is dependent upon the induction of IFN-gamma, it does not rely upon the anti-microbial effect of NO. Nahrung, 1998 Aug, 42(3-4), 162 - 5 Substrate and binding specificity of aspartic proteases with milk clotting properties; Krause W et al.; The hydrolysis of whole casein and isolated casein components were investigated with the purpose of obtaining information concerning the kinetic and specifty of aspartic proteases in rennin, pepsin and 4 microbial rennet substitutes . The velocity of hydrolysis decreased rapidly within the first hour . However, the hydrolysis was not completed after 2 days . A mathematical description of the slope of hydrolysis is possible by use of exponential equations . More than 40 peptides were detected by capillary electrophoresis or PAGE . The characterization of the C- and N-terminal amino acids of peptides shows that the hydrolysis of any peptide bond depends mainly on the structure of the C-terminal side chains of the amino acids . The detection of the basic amino acids lysin and arginin in the C-terminal position of peptides is a new result, furthering the knowledge about the specificity of aspartic proteases . Differences in the reaction velocity or in the extent of hydrolysis are one of the possible explanations for the described differences in the rennet curd yield . It was concluded that the rennet enzymes are active also in the later phases of cheese ripening and are able to support the action of cheese ripening flora. Nahrung, 1998 Aug, 42(3-4), 151 - 4 Crosslinking of sodium caseinate by a microbial transglutaminase; Lorenzen PC et al.; Sodium caseinate is an effective substrate for transglutaminase . Crosslinking takes place at fast reaction rates resulting in high degrees of crosslinking . The polymers can be hydrolysed by trypsin, but the proteolysates contain residual portions of non- or partlyhydrolysed aggregates . Crosslinking of hydrolysed sodium caseinate decreased the number of free amino groups, but leads only to a very small increase in molecular weight of the peptides. Przegl Epidemiol, 1998, 52(1-2), 171 - 82 {Sterile packaging}; Rohm-Rodowald E et al.; After decontamination, cleaning, maintenance and functional testing, sterilized items must be packed suitably . The package must protect sterilized items against microbial contamination during removal from the sterilising chamber, and during storage or transport until use . The sterilized material must be packaged in suitable packaging material in accordance with the sterilising method . Sterilization packaging must conform to standards . There are not Polish standards for sterile packaging of medical devices . The article give general guidelines about: properties of sterile packaging, various national standards and European Standard, the packaging materials, general compatibility with the sterilization process which is intended to be used, general compatibility with the package forming process, and shelf life considerations. Schweiz Med Wochenschr, 1998 Aug 4, 128(31-32), 1175 - 80 {How (deficient) copper causes illness}; Solioz M et al.; Copper is an essential cofactor in all cells . However, it remains largely unknown how cells deal with this element, which is essential yet toxic . Through the study of microbial model systems on the one hand, and the investigation of inherited diseases in copper metabolism on the other, important insights into the way cells deal with copper can be gained . Two key new elements of copper metabolism have emerged from these studies: ATP-driven copper pumps and intracellular copper transport proteins, the copper chaperones. Planta, 1998 Oct, 206(2), 167 - 74 Fatty acid signaling in Arabidopsis; Farmer EE et al.; Many organisms use fatty acid derivatives as biological regulators . In plants, for example, fatty acid-derived signals have established roles in the regulation of developmental and defense gene expression . Growing numbers of these compounds, mostly derived from fatty acid hydroperoxides, are being characterized . The model plant Arabidopsis thaliana is serving a vital role in the discovery of fatty acid-derived signal molecules and the genetic analysis of their synthesis and action . The Arabidopsis genome sequencing project, the availability of large numbers of mutants in fatty acid biosynthesis and signal transduction, as well as excellent pathosystems, make this plant a tremendously useful model for research in fatty acid signaling . This review summarizes recent progress in understanding fatty acid signaling in A . thaliana and highlights areas of research where progress is rapid . Particular attention is paid to the growing literature on the jasmonate family of regulators and their role in defense against insects and microbial pathogens. J Neurosci, 1998 Sep 15, 18(18), 7296 - 305 Regional selective neuronal degeneration after protein phosphatase inhibition in hippocampal slice cultures: evidence for a MAP kinase-dependent mechanism; Runden E et al.; The regional selectivity and mechanisms underlying the toxicity of the serine/threonine protein phosphatase inhibitor okadaic acid (OA) were investigated in hippocampal slice cultures . Image analysis of propidium iodide-labeled cultures revealed that okadaic acid caused a dose- and time-dependent injury to hippocampal neurons . Pyramidal cells in the CA3 region and granule cells in the dentate gyrus were much more sensitive to okadaic acid than the pyramidal cells in the CA1 region . Electron microscopy revealed ultrastructural changes in the pyramidal cells that were not consistent with an apoptotic process . Treatment with okadaic acid led to a rapid and sustained tyrosine phosphorylation of the mitogen-activated protein kinases ERK1 and ERK2 (p44/42(mapk)) . The phosphorylation was markedly reduced after treatment of the cultures with the microbial alkaloid K-252a (a nonselective protein kinase inhibitor) or the MAP kinase kinase (MEK1/2) inhibitor PD98059 . K-252a and PD98059 also ameliorated the okadaic acid-induced cell death . Inhibitors of protein kinase C, Ca2+/calmodulin-dependent protein kinase II, or tyrosine kinase were ineffective . These results indicate that sustained activation of the MAP kinase pathway, as seen after e.g., ischemia, may selectively harm specific subsets of neurons . The susceptibility to MAP kinase activation of the CA3 pyramidal cells and dentate granule cells may provide insight into the observed relationship between cerebral ischemia and dementia in Alzheimer's disease. J Mol Biol, 1998 Sep 18, 282(2), 435 - 46 Elucidation of the mode of interaction of thermolysin with a proteinaceous metalloproteinase inhibitor, SMPI, based on a model complex structure and a structural dynamics analysis; Tate S et al.; SMPI is a proteinaceous microbial metalloproteinase inhibitor that was isolated from Streptomyces nigrescens TK-23 in 1979 . SMPI is known to selectively inhibit the metalloproteinases in the gluzincin family, according to the Rawling and Barrett classification . There has been no report on the interaction of a metalloproteinase in the family of gluzincins with its specific proteinaceous inhibitor . We have solved the solution structure of SMPI by NMR . Here, we report the binding mode of SMPI to thermolysin, based on the model complex structure generated using our high-resolution NMR structure of SMPI and the crystal structure of thermolysin . The obtained complex model shows that the extruded loop of SMPI, with the scissile bond Cys64-Val65, is complementary in shape to the active cleft of thermolysin . In the complex, the Cys64 (P1) carbonyl oxygen atom can form a tetrahedral coordination to the active zinc in thermolysin, and simultaneously, the methyl groups of Val65 (P1') are closely located in the hydrophobic S1' pocket in thermolysin . From the electrostatic potential surface calculation, the active loop of SMPI and the active cleft in thermolysin have been shown to be complementary in the surface charge distribution, resulting in the stabilization of the complex . The apparently large active loop is less flexible, but maintains a conformation in the nano- to picosecond time-scale, as elucidated from the 15N spin relaxation analysis . This is a quite different structural feature of SMPI from the flexible binding loop generally found in the serine proteinase inhibitors, such as SSI and eglin c, and can be related to the narrow specificity of SMPI . The present study provides the first insight into the interaction between a proteinaceous inhibitor and a gluzincin metalloproteinase . J Theor Biol, 1998 Aug 7, 193(3), 429 - 44 A stochastic model for the rapid emergence of specific vertebrate immunity incorporating horizontal transfer of systems enabling duplication and combinational diversification; Marchalonis JJ et al.; Recent molecular data indicate that the antigen-specific combinatorial immune response is restricted to jawed vertebrates where it is found in representatives of all class from cartilagenous fishes to mammals . Here, we analyse the relatively rapid emergence of the combinatorial system terms of three stochastic process, with the system reaching essentially full capacity in immunoglobulin recognition elements and diversification and recombination of gene segments in an evolutionary span of time of less than 20 million years . The mechanisms for inducibility were coopted from ancient and widely spread processes in phylogeny for regulation of cell division . The proposed process of formation entailed the evolution of unknown ancestral genes into those specifying bona fide immunoglobulin domains, and the generation of multiple copies of these via a series of events facilitated by horizontal transfer of site-specific recombinases and recombination signal sequences most probably from microbial and fungal sources . The second process is one of rapid "decay" (evolution) which occurred in about 10 million year under stringent selective conditions to generate proper conserved canonical sequences . The third process is that of the long term evolution of these characteristic immunoglobulin domains over the 450 million years since their emergence . As a first approximation the rates of these three processes were computed using first order differential equations . The rate of formation has a magnitude of 10-7 substitutions per site per year, and that of rapid modifications is 10-8 substitutions per site per year . The long term rate of immunoglobulin evolution is comparable to that of other moderately conserved proteins, (1-3) x 10-9 substitutions per site per year) . This model is testable by searching for "footprints" of microbial and fungal DNA processing enzymes and recombination mechanisms . The hypothesis raises the general concept that horizontal transfer of genes facilitating rearrangement and duplication can catalyse major steps of macroevolution. J Virol, 1998 Oct, 72(10), 8281 - 8 Long-term CD4 Th1 and Th2 memory following acute lymphocytic choriomeningitis virus infection; Whitmire JK et al.; CD4 T cells play a central role in viral immunity . They provide help for B cells and CD8 T cells and can act as effectors themselves . Despite their importance, relatively little is known about the magnitude and duration of virus-specific CD4 T-cell responses . In particular, it is not known whether both CD4 Th1 memory and CD4 Th2 memory can be induced by viral infections . To address these issues, we quantitated virus-specific CD4 Th1 (interleukin 2 {IL-2} and gamma-interferon) and Th2 (IL-4) responses in mice acutely infected with lymphocytic choriomeningitis virus (LCMV) . Using two sensitive assays (enzyme-linked immunospot assay and intracellular stain) to measure cytokine production at the single-cell level, we found that both CD4 Th1 and Th2 responses were induced during primary LCMV infection . At the peak (day 8) of the response, the frequency of LCMV-specific CD4 Th1 cells was 1/35 to 1/160 CD4 T cells, and the frequency of Th2 cells was 1/400 . After viral clearance, the numbers of virus-specific CD4 T cells dropped to 1/260 to 1/3,700 and then were maintained at this level indefinitely . Upon rechallenge with LCMV, both CD4 Th1 and Th2 memory cells made an anamnestic response in vivo . These results show that unlike some microbial infections in which only Th1 or Th2 responses are seen, an acute viral infection can induce a mixed CD4 T-cell response with long-term memory. J Biol Chem, 1998 Sep 18, 273(38), 24309 - 13 Phosphatidylinositides bind to plasma membrane CD14 and can prevent monocyte activation by bacterial lipopolysaccharide; Wang PY et al.; Although bacterial lipopolysaccharides (LPS) and several other microbial agonists can bind to mCD14 (membrane CD14), a cell-surface receptor found principally on monocytes and neutrophils, host-derived mCD14 ligands are poorly defined . We report here that phosphatidylinositol (PtdIns), phosphatidylinositol-4-phosphate, and other phosphatidylinositides can bind to mCD14 . Phosphatidylserine (PS), another anionic glycerophospholipid, binds to mCD14 with lower apparent affinity than does PtdIns . LPS-binding protein, a lipid transfer protein found in serum, facilitates both PS- and PtdIns-mCD14 binding . PtdIns binding to mCD14 can be blocked by anti-CD14 monoclonal antibodies that inhibit LPS-mCD14 binding, and PtdIns can inhibit both LPS-mCD14 binding and LPS-induced responses in monocytes . Serum-equilibrated PtdIns also binds to mCD14-expressing cells, raising the possibility that endogenous PtdIns may modulate cellular responses to LPS and other mCD14 ligands in vivo. Arch Environ Contam Toxicol, 1998 Oct, 35(3), 404 - 11 Influence of trophic status on the toxic effects of a herbicide: A microcosm study Pratt JR, Barreiro R. Naturally derived microbial communities were developed in the laboratory under three nutrient regimes by manipulating phosphate and nitrate concentrations . Resulting communities differed in both functional and structural attributes . Low nutrient microcosms (0.05 mg N-NO3-/L + 0.01 mg P-PO4-3/L) showed the sharpest differences . Medium (0.5 mg N-NO3-/L + 0.1 mg P-PO4-3/L) and high (5.0 mg N-NO3-/L + 1.0 mg P-PO4-3/L) nutrient treatments differed in total algal biomass and algal community composition . After a 25-day acclimation period, a single dose of the herbicide diquat (3.5 mg/L) was added to test the response of the microbial communities to herbicide stress . Regardless of nutrient regime, diquat-dosed microcosms had decreased electron transport system activity (ETSA), an almost complete absence of cyanobacteria, and reduced gross photosynthesis (GP), respiration, and pH relative to undosed microcosms . Inorganic nutrients (PO4-3, NO3-) were released from the stressed algal communities, probably as a result of their altered metabolism . Alkaline phosphatase activity (APA), total microbial biomass (estimated as protein), algal biomass (estimated as chlorophyll), and relative abundance of green algal taxa proved highly insensitive to herbicide action . Nutrient treatments had a small influence on toxicant effects; the magnitude of the herbicide effects was comparable across nutrient levels . Only the capacity of recovery from the toxic stress was affected by trophic status . At the end of the study period, ETSA had recovered to control values in high nutrient microcosms but not in medium and low ones . Microcosm pH, and to a lesser extent GP, showed recovery under both high and medium nutrient treatments . Trophic status affected the diquat disappearance rate; the herbicide persisted longer in low nutrient microcosms than in high and medium nutrient ones . Differences in recovery capacity may stem from higher nutrient level microcosms reaching less toxic herbicide levels in a shorter period of time. Dig Dis, 1998 Jul-Aug, 16(4), 192 - 7 Helicobacter infection in man: problems to be solved; Tytgat GN; Helicobacter pylori (Hp) infection in man has several disease outcomes, varying from asymptomatic chronic gastric inflammation to Hp-associated dyspepsia, pepic ulcer disease, gastric adenocarcinoma, and Malt lymphoma . Particularly controversial is the role of Hp infection in the genesis of chronic dyspeptic symptoms . Only a small percentage of chronic dispeptics have long-lasting remission of the complaints after cure of the infection . It is now well established that healing of the inflammation through microbial eradication cures peptic ulcer disease . The high efficacy of bismuth or PPI triple and quadruple therapies is overshadowed by the rising resistance to metronidazole and clarithromycin . The exact role of Hp in gastric carcinogenesis in the various geographical areas needs further study . The results of ongoing trials, evaluating the long-term outcome of Hp cure, on cancer rates are anxiously awaited . The acquisition rate of new knowledge through basal and clinical Hp research has rarely been witnessed in medicine. Hepatology, 1998 Sep, 28(3), 620 - 3 Increased CD1d expression on small bile duct epithelium and epithelioid granuloma in livers in primary biliary cirrhosis; Tsuneyama K et al.; Cluster of differentiation 1 (CD1) is a family of four distinct nonpolymorphic major histocompatibility complex class I-like molecules that can present microbial nonpeptide lipid antigens to T cells . Among the CD1 gene family, CD1d is found in a wide range of tissues including the intestine and liver, and has been proposed to play an important role in mucosal immunity . Primary biliary cirrhosis (PBC) is an immune-mediated liver disease involving the intrahepatic small bile ducts, which also belong to the mucosal immune system . In this study, we studied the expression of CD1d in patients with PBC and compared the data with those of patients with hepatic sarcoidosis, primary sclerosing cholangitis (PSC), chronic viral hepatitis (CVH), and normal liver as controls . CD1d was found to be expressed in hepatocytes in all cases examined, and in epithelioid granuloma cells in 19 of 22 PBC livers and in 4 of 4 livers with hepatic sarcoidosis . In addition, CD1d was focally expressed on epithelial cells of the small bile ducts in approximately 50% of the PBC patients but in no controls . Such bile duct epithelial staining of CD1d was seen in early-stage PBC and virtually absent in late-stage PBC . Moreover, there was no evidence of expression of CD1d in large bile duct epithelial cells of PBC . The CD1d on biliary epithelial cells in PBC may be involved in the antigen presentation of microbial lipid antigen(s) to surrounding T cells . Alternatively, modified endogenous lipidic compounds may share analogy with bacterial lipid antigens and explain CD1d expression, a possible epiphenomenon rather than a proof of bacterial involvement. Acta Medica (Hradec Kralove), 1998, 41(2), 91 - 3 How long can the previously assembled cardiopulmonary bypass circuit stay sterile? Lonsky V, Voxova B, Dominik J, Mandak J, Kubicek J, Bimova J, Markova D, Matoulkova P. The sterility of previously assembled cardiopulmonary bypass circuits was investigated for 100 extracorporeal circuits . The closed circuits were assembled using aseptic technique and remained in the pump room until time of use . The mean time from point of setup to point of priming for the 100 consecutive circuits was 32 hours, with a range of 19 to 89 hours . Circuits were primed with the calculated volume of priming solution, circulated for 5 minutes and tested for microbial contamination by withdrawing 20 ml of the priming solution and 10 days incubated in Thioglycolate and Sabouraud culture mediums . All were found to be free of microbial contamination . The results of this investigation demonstrate that the sterility of the extracorporeal circuit, pre-assembled in advance of actual priming, can be maintained over an extended interval when standard aseptic technique is used . This allows the utilization of a pre-assembled circuit for emergency cardiopulmonary support.
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