Bacteriological

Appl Environ Microbiol, 2001 Sep, 67(9), 4365 - 71
Diversity and distribution in hypersaline microbial mats of bacteria related to Chloroflexus spp; Nubel U et al.; Filamentous bacteria containing bacteriochlorophylls c and a were enriched from hypersaline microbial mats . Based on phylogenetic analyses of 16S rRNA gene sequences, these organisms form a previously undescribed lineage distantly related to Chloroflexus spp . We developed and tested a set of PCR primers for the specific amplification of 16S rRNA genes from filamentous phototrophic bacteria within the kingdom of "green nonsulfur bacteria." PCR products recovered from microbial mats in a saltern in Guerrero Negro, Mexico, were subjected to cloning or denaturing gradient gel electrophoresis and then sequenced . We found evidence of a high diversity of bacteria related to Chloroflexus which exhibit different distributions along a gradient of salinity from 5.5 to 16%.

Appl Environ Microbiol, 2001 Sep, 67(9), 4324 - 8
Mapping microbial biodiversity; Stoner DL et al.; We report the development of a prototype database that "maps" microbial diversity in the context of the geochemical and geological environment and geographic location . When it is fully implemented, scientists will be able to conduct database searches, construct maps containing the information of interest, download files, and enter data over the Internet.

Appl Environ Microbiol, 2001 Sep, 67(9), 4233 - 41
Bacteriophage latent-period evolution as a response to resource availability; Abedon ST et al.; Bacteriophages (phages) modify microbial communities by lysing hosts, transferring genetic material, and effecting lysogenic conversion . To understand how natural communities are affected it is important to develop predictive models . Here we consider how variation between models--in eclipse period, latent period, adsorption constant, burst size, the handling of differences in host quantity and host quality, and in modeling strategy--can affect predictions . First we compare two published models of phage growth, which differ primarily in terms of how they model the kinetics of phage adsorption; one is a computer simulation and the other is an explicit calculation . At higher host quantities (approximately 10(8) cells/ml), both models closely predict experimentally determined phage population growth rates . At lower host quantities (10(7) cells/ml), the computer simulation continues to closely predict phage growth rates, but the explicit model does not . Next we concentrate on predictions of latent-period optima . A latent-period optimum is the latent period that maximizes the population growth of a specific phage growing in the presence of a specific quantity and quality of host cells . Both models predict similar latent-period optima at higher host densities (e.g., 17 min at 10(8) cells/ml) . At lower host densities, however, the computer simulation predicts latent-period optima that are much shorter than those suggested by explicit calculations (e.g., 90 versus 1,250 min at 10(5) cells/ml) . Finally, we consider the impact of host quality on phage latent-period evolution . By taking care to differentiate latent-period phenotypic plasticity from latent-period evolution, we argue that the impact of host quality on phage latent-period evolution may be relatively small.

Burns, 2001 Sep, 27(6), 621 - 7
The use of silver coated dressings on donor site wounds: a prospective, controlled matched pair study; Innes ME et al.; Acticoat, a new silver-coated dressing, produces a moist healing environment along with the sustained release of ionic silver for improved microbial control . These properties suggest that Acticoat might be a useful donor site dressing . However, there are no human studies which assess Acticoat for this use . The purpose of this study was to compare the healing of human skin graft donor sites dressed with Acticoat, to the healing of those dressed with Allevyn, an occlusive moist-healing environment material, which is our standard donor site dressing . In burn patients who had undergone burn excision and grafting, identical side-by-side split thickness donor site wound pairs were dressed with Allevyn and Acticoat . Re-epithelialization was directly assessed daily by a single observer from post-operative day 6 onward, and by four independent observers who rated the extent of re-epithelialization by viewing standardized digital images of the wounds that had been obtained on post-operative days 6, 8, 10,and 12 . Donor sites were swabbed for bacterial culture on days 3, 6, and 9 . Subsequently, each study donor site scar was rated by a blinded observer using the Vancouver Scar Scale at 1, 2, and 3 months . Sixteen paired sites in 15 patients (3 female, 12 male) were studied . Donor sites dressed with Allevyn were >90% re-epithelialized at a mean of 9.1+/-1.6 days while donor sites dressed with Acticoat required a mean of 14.5+/-6.7 days to achieve >90% re-epithelialization (P=0.004) . The Allevyn sites had significantly greater estimated re-epithelialization at days 6, 8, 10 and 12 than the Acticoat sites based on the observations of the digital images . There were no significant differences in the incidence of positive bacterial cultures with either dressing at days 3, 6, and 9 . Donor sites dressed with Acticoat had significantly worse scars at 1 and 2 months but this difference resolved by 3 months . Our findings do not support the use of Acticoat as a skin graft donor site dressing.

Appl Microbiol Biotechnol, 2001 Jun, 55(6), 787 - 93
Microbial sulfate reduction with acetate: process performance and composition of the bacterial communities in the reactor at different salinity levels; Muthumbi W et al.; Microbial sulfate reduction with acetate as carbon source and electron donor was investigated at salinity levels between 0.53 and 1.48% . The experiment was carried out in a 2.3-1 upflow anaerobic sludge blanket reactor inoculated with granular methanogenic sludge . A pH of 8.3, a temperature of 32 +/- 1 degrees C and a chemical oxygen demand (COD)/SO4(2-)-S ratio of 2 were maintained in the reactor throughout the experiment . Sulfate reduction and the composition of the dominant bacterial communities in the reactor were monitored . The results showed that a maximal conversion rate for SO4(2-)-S of 14 g l(-1) day(-1) and a conversion efficiency of more than 90% were obtained at a salinity level of 1.26-1.39% . A further increase in the salinity level led to reactor instability . Denaturant gradient gel electrophoresis of 16S rDNA fragments amplified by PCR from total bacterial DNA extracted from the inoculum and reactor sludge showed that salinity level had an impact on the composition of the bacterial communities in the reactor . However, no clear relationship was found between reactor performance and the composition of the dominant bacterial communities in the reactor.

J Periodontol, 2001 Aug, 72(8), 1038 - 44
Regulation of cytokine production in human gingival fibroblasts following treatment with nicotine and lipopolysaccharide; Wendell KJ et al.; BACKGROUND: Patients who smoke are at increased risk for chronic periodontitis (CP) . Most studies suggest that the microbial flora in these patients is similar to that found in non-smoking CP patients . Thus, the increased risk for development of CP is not dependent on an altered microbial profile, but rather to some change in the host response to these periopathogens . There is evidence that human gingival fibroblasts (HGF) derived from diseased sites produce greater amounts of interleukin (IL)-6 and IL-8 in vitro than cells derived from healthy sites . This suggests that HGF subpopulations may be selected based upon the inflammatory milieu in which they reside . The hypothesis to be tested was that the combination of nicotine and lipopolysaccharide (LPS) could regulate HGF inflammatory mediator production . METHODS: HGF cell cultures were established from explants derived from 10 patients with CP . HGF cell cultures were stimulated with 1 mM, 1 microM, or 1 nM nicotine +/- Escherichia coli or Porphyromonas gingivalis LPS . At 12, 24, or 48-hour time points, the cells were counted and the supernatant was collected for subsequent IL-6 and IL-8 determination in an enzyme-linked immunosorbent assay . RESULTS: At the 24-hour time point, 1 nM nicotine stimulated IL-6 production compared to control (P=0.02) . E . coli LPS alone caused a 3- to 4-fold increase in IL-6 and IL-8 production, whereas P gingivalis LPS did not augment IL-6 or IL-8 . A synergistic effect upregulating IL-6 was observed with combined treatment of 1 mM nicotine and E . coli LPS or P gingivalis LPS at the 24-hour time point (P<0.0005 and P=0.002, respectively) . Similar effects were seen when IL-8 production was evaluated following HGF stimulation with high doses of nicotine and E . coli LPS or P gingivalis LPS . CONCLUSIONS: These results demonstrate that nicotine by itself can stimulate HGF IL-6 and IL-8 production . Moreover, the combination of high doses of nicotine and either E . coli or P gingivalis LPS can synergistically upregulate cytokine production . These findings support the hypothesis that a proinflammatory fibroblast phenotype may be elicited in an environment enriched with bacterial LPS and nicotine.

Curr Genet, 2001 Jul, 39(5-6), 365 - 70
Highly efficient expression of rabbit neutrophil peptide-1 gene in Chlorella ellipsoidea cells; Chen Y et al.; A highly efficient system was developed for the expression of foreign genes in Chlorella ellipsoidea cells . The effect of five promoters on the expression efficiency of beta-glucuronidase (GUS) gene was evaluated by transient expression of the UidA gene . Among these promoters, Ubiquitin-omega was found to be the most efficient and was selected to drive the expression of foreign genes in Chlorella cells . A gene encoding the mature rabbit neutrophil peptide-1 (NP-1) was introduced into the cells . Integration of the gene for NP-1 into the Chlorella genome was confirmed by PCR and Southern blot analysis . In, vitro anti-microbial testes demonstrated the expression of biologically active NP-1 by the transgenic Chlorella cells.

Structure (Camb), 2001 Apr 4, 9(4), 311 - 9
Crystal structures of a novel ferric reductase from the hyperthermophilic archaeon Archaeoglobus fulgidus and its complex with NADP+; Chiu HJ et al.; BACKGROUND: Studies performed within the last decade have indicated that microbial reduction of Fe(III) to Fe(II) is a biologically significant process . The ferric reductase (FeR) from Archaeoglobus fulgidus is the first reported archaeal ferric reductase and it catalyzes the flavin-mediated reduction of ferric iron complexes using NAD(P)H as the electron donor . Based on its catalytic activity, the A . fulgidus FeR resembles the bacterial and eukaryotic assimilatory type of ferric reductases . However, the high cellular abundance of the A . fulgidus FeR (approximately 0.75% of the total soluble protein) suggests a catabolic role for this enzyme as the terminal electron acceptor in a ferric iron-based respiratory pathway {1} . RESULTS: The crystal structure of recombinant A . fulgidus FeR containing a bound FMN has been solved at 1.5 A resolution by multiple isomorphous replacement/ anomalous diffraction (MIRAS) phasing methods, and the NADP+- bound complex of FeR was subsequently determined at 1.65 A resolution . FeR consists of a dimer of two identical subunits, although only one subunit has been observed to bind the redox cofactors . Each subunit is organized around a six-stranded antiparallel beta barrel that is homologous to the FMN binding protein from Desulfovibrio vulgaris . This fold has been shown to be related to a circularly permuted version of the flavin binding domain of the ferredoxin reductase superfamily . The A . fulgidus ferric reductase is further distinguished from the ferredoxin reductase superfamily by the absence of a Rossmann fold domain that is used to bind the NAD(P)H . Instead, FeR uses its single domain to provide both the flavin and the NAD(P)H binding sites . Potential binding sites for ferric iron complexes are identified near the cofactor binding sites . CONCLUSIONS: The work described here details the structures of the enzyme-FMN, enzyme-FMN-NADP+, and possibly the enzyme-FMN-iron intermediates that are present during the reaction mechanism . This structural information helps identify roles for specific residues during the reduction of ferric iron complexes by the A . fulgidus FeR.

FEMS Microbiol Rev, 2001 Aug, 25(4), 455 - 501
Classification and phylogeny of hydrogenases; Vignais PM et al.; Hydrogenases (H2ases) catalyze the reversible oxidation of molecular hydrogen and play a central role in microbial energy metabolism . Most of these enzymes are found in Archaea and Bacteria, but a few are present in Eucarya as well . They can be distributed into three classes: the {Fe}-H2ases, the {NiFe}-H2ases, and the metal-free H2ases . The vast majority of known H2ases belong to the first two classes, and over 100 of these enzymes have been characterized genetically and/or biochemically . Compelling evidence from sequences and structures indicates that the {NiFe}- and {Fe}-H2ases are phylogenetically distinct classes of proteins . The catalytic core of the {NiFe}-H2ases is a heterodimeric protein, although additional subunits are present in many of these enzymes . Functional classes of {NiFe}-H2ases have been defined, and they are consistent with categories defined by sequence similarity of the catalytic subunits . The catalytic core of the {Fe}-H2ases is a ca . 350-residue domain that accommodates the active site (H-cluster) . A few monomeric {Fe}-H2ases are barely larger than the H-cluster domain . Many others are monomeric as well, but possess additional domains that contain redox centers, mostly iron-sulfur . Some {Fe}-H2ases are oligomeric . The modular structure of H2ases is strikingly illustrated in recently unveiled sequences and structures . It is also remarkable that most of the accessory domains and subunits of H2ases have counterparts in other redox complexes, in particular NADH-ubiquinone oxidoreductase (Complex I) of respiratory chains . Microbial genome sequences are bringing forth a significant body of additional H2ase sequence data and contribute to the understanding of H2ase distribution and evolution . Altogether, the available data suggest that {Fe}-H2ases are restricted to Bacteria and Eucarya, while {NiFe}-H2ases, with one possible exception, seem to be present only in Archaea and Bacteria . H2ase processing and maturation involve the products of several genes which have been identified and are currently being characterized in the case of the {NiFe}-H2ases . In contrast, near to nothing is known regarding the maturation of the {Fe}-H2ases . Inspection of the currently available genome sequences suggests that the {NiFe}-H2ase maturation proteins have no similar counterparts in the genomes of organisms possessing {Fe}-H2ases only . This observation, if confirmed, would be consistent with the phylogenetic distinctiveness of the two classes of H2ases . Sequence alignments of catalytic subunits of H2ases have been implemented to construct phylogenetic trees that were found to be consistent, in the main, with trees derived from other data . On the basis of the comparisons performed and discussed here, proposals are made to simplify and rationalize the nomenclature of H2ase-encoding genes.

FEMS Microbiol Rev, 2001 Aug, 25(4), 425 - 35
Genomic style of proteins: concepts, methods and analyses of ribosomal proteins from 16 microbial species; Radomski JP et al.; We have introduced the concept of genomic 'style' of proteins . By style we understand those properties of a large set of proteins which are specific to the genome of one species (species primary-self) and different from the genome of another species (species contrasted-self) . To characterise the style, we took advantage of the frequencies of amino acids and dipeptides present in non-identical segments of the complete set of orthologous ribosomal proteins encoded by 16 microbial species . We confirm the dependence of the overall amino acid composition on the genomic (G+C) content, and introduce a rectification procedure making it possible to extricate appropriate species-specific characteristics, which are no longer related to this content . The rectified frequencies are used to calculate inter-species distance matrices, and to build genomic evolutionary trees . Remarkably, the phylograms derived from the frequencies of non-identical residues in proteins closely resemble the classical phylograms based upon the conservation of identical residues in ribosomal RNAs . We believe that the concept of genomic style of proteins can be a useful tool for the study of evolution.

Yakugaku Zasshi, 2001 Aug, 121(8), 593 - 600
{Efficient gene delivery into dendritic cells by fiber-mutant adenovirus vectors}; Okada N; Dendritic cells (DC) are professional antigen-presenting cells with a key function in the immune system as initiators of T-cell responses against microbial pathogens and tumors . Therefore, the immunization using DC loaded with tumor-associated antigens is potential to represent a powerful method of inducing anti-tumor immunity . Recent studies have demonstrated the usefulness of DC genetically modified by adenovirus vectors (Ad) to immunotherapy, while sufficient gene transduction into DC is required for high doses of Ad . Entry of Ad into target cells occurs by serial two steps: the binding of Ad-fiber knob to Coxsackie-adenovirus receptor (CAR) on the cell surface, and the subsequent interaction between Arg-Gly-Asp (RGD) motif located in Ad-penton base and alpha v-integrins . The reverse transcription-polymerase chain reaction analysis revealed that the relative resistance of DC to Ad-mediated gene transfer was due to the absence of CAR expression, and that DC expressed adequate alpha v-integrins . Therefore, we investigated whether fiber-mutant Ad (FM-Ad) containing the RGD sequence in the fiber knob can efficiently transduce and express high levels of the foreign gene into DC . The gene delivery by FM-Ad was more efficient than that by conventional Ad in both murine DC lines and normal human DC . Furthermore, both antigen presentations via major histocompatibility complex class I molecules and in vivo antigen-specific cytotoxic T lymphocyte induction by DC transduced with antigen gene by FM-Ad were superior to those by DC applied with conventional AD . We propose that alpha v-integrin-targeted FM-Ad is a very powerful tool to implement DC-based vaccination strategies.

J Endotoxin Res, 2000, 6(6), 453 - 7
Molecular mechanisms of NF-kappaB activation induced by bacterial lipopolysaccharide through Toll-like receptors; Zhang G et al.; Septic shock, caused by exaggerated host responses to various microbial products typified by lipopolysaccharide (LPS), remains the leading cause of death in trauma patients . Gaining insight into the nature of host interactions with LPS will certainly facilitate attempts to develop effective anti-sepsis drugs . Tremendous progress has been made during the past few years in understanding the mechanisms of pathogen-induced host responses . Toll-like receptor (TLR) 4 and 2 have been implicated as major receptors for signaling initiated by LPS and many other microbial products following their binding to CD14 . In addition, many signaling intermediates involved in LPS-induced cell activation, particularly activation of the transcription factor NF-kappaB, have been identified and characterized . Further investigations with these molecules will certainly reward us with more effective therapeutic drugs to treat septic shock as well as many other inflammatory and infectious disorders.

Early Hum Dev, 2001 Oct, 65(1), 11 - 9
The characterization of superoxide production of human neonatal neutrophil; Komatsu H et al.; To assess the role of neutrophil in neonatal host defense against microbial infection, we characterized the superoxide anion (O(2-)) production of neonatal neutrophil on a biochemical basis . After taking an appropriate informed consent, neutrophils were obtained from cord blood immediately after transvaginal delivery and divided into two groups: the Preterm group, 15 neonates (27-36 weeks' gestation) and the Term group, 15 neonates (37-41 weeks' gestation) . Eleven healthy adults served as controls in the Adult group . The value of N-formyl-methionyl-leucyl-phenylalanin (fMLP)-induced O(2-) production activity of neutrophils in the Preterm group using chemiluminescence assay was significantly lower than those values in both the Term and Adult groups (5.77+/-0.53x10(6) vs . 11.1+/-0.94x10(6) and 10.7+/-0.63x10(6) cpm; mean+/-S.E.M., p<0.05) . In phorbol 12-myristate 13-acetate (PMA)-stimulation, the values of O(2-) production activity of neutrophils in both the Preterm and Term groups were significantly lower than that in the Adult group (13.0+/-1.66x10(6) and 18.0+/-1.44x10(6) vs . 27.3+/-1.45x10(6) cpm, p<0.05) . Scatchard analysis of {(3)H}fMLP binding to neutrophil demonstrated a two-receptor model in each group, and the number of high-affinity receptors per neutrophil in the Preterm group was significantly lower than those in other groups (p<0.05) . However, cord blood levels of proinflammatory cytokines, such as interleukin (IL)-6, -8, and tumor necrosis factor-alpha (TNF-alpha) did not differ in either neonatal group . These results indicated that the fMLP-induced O(2-)production activity of neutrophils in the term neonates was enhanced at the level of the receptor and suggested that this enhanced production contribute to the neonatal host defense against microbial infection.

J Nat Prod, 2001 Aug, 64(8), 1098 - 9
Microbial transformation of pyrethrosin; Galal AM; Microbial transformation of the germacranolide pyrethrosin (1) using Rhizopus nigricans NRRL 1477 has resulted in the isolation of 6 alpha-acetoxy-1 beta,4 alpha-dihydroxy-5,7 alpha H,8 beta H-eudesm-11 beta,13-dihydro-8,12-olide (5), a new eudesmanolide-type metabolite, in addition to the previously reported eudesmanolides: 2, 3, 4, and 6 . The structure elucidation of these metabolites was based primarily on 1D and 2D NMR analyses . The isolated metabolites exhibited cytotoxic, antifungal, and antiprotozoal activities.

Am J Physiol Gastrointest Liver Physiol, 2001 Sep, 281(3), G764 - 78
Helicobacter-induced inflammatory bowel disease in IL-10- and T cell-deficient mice; Burich A et al.; Inflammatory bowel disease (IBD) is thought to result from a dysregulated mucosal immune response to luminal microbial antigens, with T lymphocytes mediating the colonic pathology . Infection with Helicobacter spp has been reported to cause IBD in immunodeficient mice, some of which lack T lymphocytes . To further understand the role of T cells and microbial antigens in triggering IBD, we infected interleukin (IL)-10(-/-), recombinase-activating gene (Rag)1(-/-), T-cell receptor (TCR)-alpha(-/-), TCR-beta(-/-), and wild-type mice with Helicobacter hepaticus or Helicobacter bilis and compared the histopathological IBD phenotype . IL-10(-/-) mice developed severe diffuse IBD with either H . bilis or H . hepaticus, whereas Rag1(-/-), TCR-alpha(-/-), TCR-beta(-/-), and wild-type mice showed different susceptibilities to Helicobacter spp infection . Proinflammatory cytokine mRNA expression was increased in the colons of Helicobacter-infected IL-10(-/-) and TCR-alpha(-/-) mice with IBD . These results confirm and extend the role of Helicobacter as a useful tool for investigating microbial-induced IBD and show the importance, but not strict dependence, of T cells in the development of bacterial-induced IBD.

Bioseparation, 2000, 9(6), 351 - 7
Sub-micron particle manipulation in an ultrasonic standing wave: applications in detection of clinically important biomolecules; Sobanski MA et al.; Separation of particles from the suspending phase is of interest, among others, to clinical analysts . A system that enables manipulation of sub-micron sized particles in suspensions of analytical scale volume (10-50 microl) using a non-cavitating ultrasonic standing wave is described . Particle suspensions, contained in glass capillary tubes of 1-2 mm internal dimension, are treated on the axis of a tubular transducer generating a radial standing wave field at 4.5 MHz . Microparticles (of average diameter range 0.3-10 microm) suspended in buffer are concentrated within seconds at preferred regions separated by submillimetre distances . Concentration of suspended latex particles was inhibited in solutions containing protein at levels similar to those occurring in clinical specimens when the suspensions were sonicated in capillaries of circular cross-section . This effect was associated with acoustic streaming of the suspending fluid . Silica microparticles (more dense and less compressible than latex) could be concentrated in the presence of streaming . Latex particles concentrated readily in square cross-section capillaries where no streaming was observed . With sub-micron particles, the geometry of the sample chamber, the suspending phase composition and the size, density and compressibility of the microparticles all influence particle manipulation . The radial standing wave system has been used to enhance agglutination of antibody-coated latex microparticles in the presence of antigen allowing rapid and highly sensitive detection of clinically important biomolecules . The sensitivity of conventional diagnostic tests for microbial antigen has been improved by application of ultrasound and clinical utility has been demonstrated, in particular, for detection of meningitis-causing bacteria.

J Anim Sci, 2001 Aug, 79(8), 2224 - 32
The effects of degradable and undegradable intake protein on the performance of lactating first-calf heifers; Anderson LP et al.; Two 60-d experiments were conducted to evaluate the effects of supplementing degradable (DIP) and(or) undegradable (UIP) intake protein on the performance of lactating first-calf heifers . Diets were formulated to meet the requirements for either DIP, metabolizable protein (MP), or both when diets contained low-quality grass hay and an efficiency of microbial protein synthesis estimate of 10% . In Exp . 1, 32 individually fed first-calf heifers (avg 395 kg) were allotted to a 2 x 2 factorial arrangement of treatments (main effects of DIP, MP, and DIP x MP interaction) 1 d after calving . Cows consumed a basal diet of chopped crested wheat grass hay (4.3% CP, 67% DIP) ad libitum . Supplemental DIP and UIP were supplied by varying the ratios of soybean meal (75% DIP) and a heat-treated, protected soybean meal (70% UIP) . Cow weight gain was better (P < 0.01) when adequate DIP was supplied than when DIP was deficient . However, calf weight gain was not increased by supplementing the cow with DIP . Supplemental UIP did not (P > 0.40) improve cow or calf weight gain . Blood urea N levels were higher (P < 0.01) for cows receiving supplemental DIP and UIP . However, milk production estimates were similar among treatments, as were digestibilities of OM and ADF . Nitrogen digestibility was greater when supplemental DIP was fed, but providing additional UIP did not (P = 0.15) change N digestibilities . Experiment 2 evaluated similar supplements using the same experimental design to determine changes in cow and calf weight gain, body condition score, and pregnancy rate . Seventy-two first-calf heifers (avg 441 kg) were allotted to supplement treatments 1 d after calving and were fed grass hay (5% CP, 53% DIP, 10% microbial efficiency) for ad libitum consumption for 60 d . Supplements were individually fed three times/week . Varying the ratios of soybean meal, heat-treated soybean meal, and corn gluten meal provided additional DIP and UIP . Unlike in Exp . 1, supplemental UIP improved (P < 0.05) cow weight gain . Calves from dams supplemented with DIP gained 5 kg more weight after 60 d than calves from dams deficient in DIP . Pregnancy rates in the fall were similar (P = 0.90) among treatments . These data suggest that DIP was more limiting in Exp . 1 than was UIP . Supplementing UIP in Exp . 2 improved cow weight gains but did not improve calf gains . Data suggest that the efficiency of microbial protein synthesis for this forage-based diet was probably less than 10%.

Adv Drug Deliv Rev, 2001 Sep 23, 51(1-3), 143 - 7
Bacteria-derived particles as adjuvants for non-replicating nasal vaccines; Haneberg B et al.; In attempts to mimic natural infections, vaccines consisting of microbial particles may be delivered directly to mucosal surfaces . In this way, the mucosal as well as the systemic immune systems can be activated . Even non-living particles of bacterial origin have been shown to elicit strong immune responses when administered intranasally . However, some particles such as formalin-inactivated influenza virus may need a mucosal adjuvant to be effective . The bacteria-derived particles seem to possess such an adjuvant activity when mixed with and given intranasally with the less immunogenic killed virus . Possibly, the bacterial particles facilitate uptake of the virus through the mucosal membranes, although an additional influence on the immune response to the virus might be mediated in the lymphoid tissue below the mucosal surface . Bacteria-derived particles in nasal vaccines may thus serve as an alternative adjuvant to derivatives of cholera toxin or the heat-labile toxin from E . coli.

Curr Biol, 2001 Jun 5, 11(11), R440 - 2
Evolution: towards a genetical theory of adaptation; Travisano M; The population genetic basis for adaptation has remained obscure despite a longstanding body of theory . Microbial selection experiments are beginning to provide some answers.

Int Immunopharmacol, 2001 Aug, 1(8), 1605 - 14
Bacterial DNA does not increase serum corticosterone concentration or prevent increases induced by other stimuli; Myers LP et al.; Bacterial DNA containing unmethylated CpG motifs (CpG DNA) and other microbial molecules such as lipopolysaccharide (LPS) have a broad range of immune stimulatory effects, which may include many shared cell signaling pathways leading to enhanced cytokine production . Some cytokines activate the hypothalamic-pituitary-adrenal (HPA) axis, and their production is downregulated by products of the HPA axis (glucocorticoids) . Because such interactions have practical implications in the clinical use of CpG DNA, the present study was done to examine the effects of CpG DNA and LPS on serum corticosterone concentrations . In contrast to LPS, administration of CpG DNA (DNA from Escherichia coli) (30-300 microg) alone did not significantly increase serum corticosterone concentrations 1 or 4 h after administration . Administration of CpG DNA to mice prior to LPS caused a synergistic increase in serum tumor necrosis factor-alpha (TNF-alpha), indicative of an immune stimulatory effect . LPS and TNF-alpha, however, induced similar levels of corticosterone with or without concomitant CpG DNA . Increasing doses of LPS caused peak corticosterone levels similar to those induced by LPS in combination with CpG DNA . Exogenous TNF-alpha administered in vivo induced comparable concentrations of corticosterone with or without CpG DNA . An alternative stressor (restraint) yielded similar levels of corticosterone with or without CpG DNA . These results indicate that CpG DNA does not induce corticosterone release or alter its release by other stimuli, indicating biologically important differences in its immune effect compared to those of LPS, and possibly reduced toxicity.

Braz J Biol, 2001 May, 61(2), 277 - 86
Microbial respiration and chemical composition of different sediment fractions in waterbodies of the upper Paraná River floodplain, Brazil; Thomaz SM et al.; Four size fractions of the sediment of six environments of the upper Parana River floodplain were analyzed for carbon, nitrogen, and phosphorus contents and microbial respiration (oxygen consumption) . Particle size did not affect nitrogen and phosphorus content or microbial activity, but did affect carbon content (F = 4.274, df = 3; 20, p = 0.020) . The carbon concentration of ultra-fine particles was significantly lower than that of other sizes of sediment particles . Microbial respiration values were well predicted by sediment chemical composition, as shown by multiple regression (microbial respiration = -0.39 - 0.210C + 0.108N + 0.796P; F = 7.0495, p = 0.0022) . However, phosphorus was the element which best explained the microbial respiration (partial coefficient = 0.796, p = 0.0039, n = 23) . Considering that i) phosphorus was the best predictor of microbial respiration; ii) phosphorus is trapped in the series of reservoirs located upstream from the section of the floodplain studied; and iii) microbial respiration is a measure of decomposition rates and nutrient cycling, we hypothesize that the long-term accumulation of litter detritus and reduction of nutrient cycling in environments of the upper Parana River floodplain are probable impacts of this decrease in phosphorus caused by the upstream reservoirs.

Trends Biotechnol, 2001 Sep, 19(9), 340 - 8
The biotechnological control of pitch in paper pulp manufacturing; Gutierrez A et al.; At present, microbial and enzymatic preparations for the control of triglyceride-containing pitch deposits during the manufacture of mechanical and sulfite paper is commercially available . However, biotechnological products for pitch control in other pulping processes, such as alkaline pulping, are under development . These products include new fungi for the removal of steroids involved in pitch deposit formation in chlorine-free pulps, to be used as a biological pretreatment of wood before pulping . Simultaneously, tailor-made enzymes are being produced using protein-engineering techniques, enabling the specific removal of pitch contaminant compounds from paper pulp.

Ann Occup Hyg, 2001 Aug, 45(6), 421 - 7
Sampling and detection of Legionella pneumophila aerosols generated from an industrial cooling tower; Ishimatsu S et al.; Cooling tower water has frequently been cited as a source of infection in outbreaks of Legionnaires' disease . However, there have been few reports on the presence of legionellae in aerosols from cooling towers . This paper describes our use of an impinger or a six-stage microbial impactor for detecting legionellae in air around a cooling tower contaminated with L . pneumophila (1.2+/-0.3x10(5) CFU/100 ml) . Phosphate-buffered saline, Page's saline, 2% yeast extract solution and buffered yeast extract (BYE) broth were tested to evaluate their collection efficiency . These solutions were compared in laboratory experiments using an aerosol of L . pneumophila serogroup (SG) 1 . Because BYE broth was the most efficient and storable collecting fluid among them, it was used for outdoor air sampling . In the outdoor air sampling, aerosolized L . pneumophila SG 6 was detected in the air around the cooling tower by the impinger (0.09 CFU/l . air) . No legionellae were detected by the impactor with Legionella-selective agar plates (WYOalpha) because the plates were overgrown with fungi . Repetitive element PCR (rep-PCR) and arbitrarily primed PCR (AP-PCR) were employed to assess the epidemiological relationship among Legionella isolates from the air sample and the cooling tower water samples . L . pneumophila SG 6 isolated from the aerosols produced rep-PCR and AP-PCR fingerprints identical to those of L . pneumophila SG 6 strains from the cooling tower water, suggesting that the bacterium was aerosolized from the cooling tower.

J Agric Food Chem, 2001 Aug, 49(8), 3718 - 24
Improvement of malt modification by use of Rhizopus VII as starter culture; Noots I et al.; The development of a selected starter culture on malting barley and its effects on malt quality aspects were studied . Application of Rhizopus sporangiospores in a malting process resulted in increased beta-glucanase and xylanase contents of the malting barley and improved starchy endosperm cell-wall degradation . Activation of the sporangiospores and optimization of the inoculation procedure led to a further increase in enzyme levels and to larger and more consistent impacts on cell-wall modification . Whereas the main effect of the starter culture on beta-glucan degradation was observed during malting, a further decrease in beta-glucan during mashing suggests that the microbial enzymes that survived the kilning step were active during mashing . Other quality aspects that were influenced by the starter culture activity were protein modification, wort color, and wort pH . The level of microbial enzymes produced was related to the amount of barley kernels infected with the starter culture.

Biochemistry, 2001 Aug 28, 40(34), 10371 - 81
Transient-state and steady-state kinetic studies of the mechanism of NADH-dependent aldehyde reduction catalyzed by xylose reductase from the yeast Candida tenuis; Nidetzky B et al.; Microbial xylose reductase, a representative aldo-keto reductase of primary sugar metabolism, catalyzes the NAD(P)H-dependent reduction of D-xylose with a turnover number approximately 100 times that of human aldose reductase for the same reaction . To determine the mechanistic basis for that physiologically relevant difference and pinpoint features that are unique to the microbial enzyme among other aldo/keto reductases, we carried out stopped-flow studies with wild-type xylose reductase from the yeast Candida tenuis . Analysis of transient kinetic data for binding of NAD(+) and NADH, and reduction of D-xylose and oxidation of xylitol at pH 7.0 and 25 degrees C provided estimates of rate constants for the following mechanism: E + NADH right arrow over left arrow E.NADH right arrow over left arrow E.NADH + D-xylose right arrow over left arrow E.NADH.D-xylose right arrow over left arrow E.NAD(+).xylitol right arrow over left arrow E.NAD(+) right arrow over left arrow E.NAD(+) right arrow over left arrow E + NAD(+) . The net rate constant of dissociation of NAD(+) is approximately 90% rate limiting for k(cat) of D-xylose reduction . It is controlled by the conformational change which precedes nucleotide release and whose rate constant of 40 s(-)(1) is 200 times that of completely rate-limiting E.NADP(+) --> E.NADP(+) step in aldehyde reduction catalyzed by human aldose reductase {Grimshaw, C . E., et al . (1995) Biochemistry 34, 14356-14365} . Hydride transfer from NADH occurs with a rate constant of approximately 170 s(-1) . In reverse reaction, the E.NADH --> E.NADH step takes place with a rate constant of 15 s(-1), and the rate constant of ternary-complex interconversion (3.8 s(-1)) largely determines xylitol turnover (0.9 s(-1)) . The bound-state equilibrium constant for C . tenuis xylose reductase is estimated to be approximately 45 (=170/3.8), thus greatly favoring aldehyde reduction . Formation of productive complexes, E.NAD(+) and E.NADH, leads to a 7- and 9-fold decrease of dissociation constants of initial binary complexes, respectively, demonstrating that 12-fold differential binding of NADH (K(i) = 16 microM) vs NAD(+) (K(i) = 195 microM) chiefly reflects difference in stabilities of E.NADH and E.NAD(+) . Primary deuterium isotope effects on k(cat) and k(cat)/K(xylose) were, respectively, 1.55 +/- 0.09 and 2.09 +/- 0.31 in H(2)O, and 1.26 +/- 0.06 and 1.58 +/- 0.17 in D(2)O . No deuterium solvent isotope effect on k(cat)/K(xylose) was observed . When deuteration of coenzyme selectively slowed the hydride transfer step, (D)()2(O)(k(cat)/K(xylose)) was inverse (0.89 +/- 0.14) . The isotope effect data suggest a chemical mechanism of carbonyl reduction by xylose reductase in which transfer of hydride ion is a partially rate-limiting step and precedes the proton-transfer step.

Chemosphere, 2001 Aug, 44(5), 1265 - 71
Fate of pyrene in contaminated soil amended with alternate electron acceptors; Nieman JK et al.; Creosote-contaminated soil samples from the Libby Ground Water Contamination Superfund Site in Libby, MT, were amended with the potential alternate electron acceptors (AEA) nitrate (KNO3), manganese oxide (MnO2), and amorphous iron oxyhydroxide (FeOOH) and incubated at low oxygen tensions (0-6% O2) . The fate of 14C-pyrene was evaluated with respect to the different soil amendments . The fate of 14C from the radiolabeled pyrene with regard to mineralization and bound residue formation within soil humic fractions was not significantly different from controls for the iron and manganese amended soils . Nitrate amendments appeared to stimulate 14C-pyrene mineralization at a level of 170 mg NO3-N kg(-1), and inhibit mineralization at 340 mg NO3-N kg(-1) . The stimulatory effect did not appear to be the result of nitrate serving as an electron acceptor . Although AEA amendments did not significantly affect the rate or extent of 14C-pyrene mineralization, results of oxygen-deprived incubations (purged with N2) indicate that AEA may be utilized by the microbial community in the unsaturated contaminated soil system.

Curr Drug Metab, 2001 Sep, 2(3), 215 - 43
Mechanism-based inactivators as probes of cytochrome P450 structure and function; Kent UM et al.; The cytochromes P450 superfamily of enzymes is a group of hemeproteins that catalyze the metabolism of an extensive series of compounds including drugs, chemical carcinogens, fatty acids, and steroids . They oxidize substrates ranging in size from ethylene to cyclosporin . Although significant efforts have been made to obtain structural information on the active sites of the microbial P450s, relatively little is currently known regarding the identities of the critical amino acid residues in the P450 active sites that are involved in substrate binding and catalysis . Since information on the crystal structures of the eukaryotic P450s has been relatively limited, investigators have used a variety of other techniques in attempts to elucide the structural features that play a role in the catalytic properties and substrate specificity at the enzyme active site . These include site-directed mutagenesis, natural mutations, homology modeling, mapping with aryl-iron complexes, affinity and photoaffinity labeling, and mechanism-based inactivators . A variety of different mechanism-based inactivators have proven to be useful in identifiying active site amino acid residues involved in substrate binding and catalysis . In this review we present a sampling of the types of studies that can be conducted using mechanism-based inactivators and highlight studies with several classes of compounds including acetylenes, isothiocyanates, xanthates, aminobenzotriazoles, phencyclidine, and furanocoumarins . Labeled peptides isolated from the inactivated proteins have been analyzed by N-terminal amino acid sequencing in conjunction with mass spectrometry to determine the sites of covalent modification . Mechanistic studies aimed at identifying the basis for the inactivation following adduct formation are also presented.

Chemosphere, 2001 Sep, 44(6), 1339 - 46
Iron-mediated reactions of polychlorinated biphenyls in electrochemical peroxidation process (ECP); Arienzo M et al.; A study was conducted to explore some of the basic processes of polychlorinated biphenyl (PCB) destruction by a new technology termed electrochemical peroxidation process (ECP) . ECP represents an enhancement of the classic Fenton reaction (H2O2 + Fe2+) in which iron is electrochemically generated by steel electrodes . Focus was on the extent of adsorption of a mixture of Aroclor 1248 on steel electrodes in comparison to iron filings . Commercially available zero-valent iron filings rapidly adsorbed PCBs from an aqueous solution of Aroclor 1248 . Within 4 h, all the PCBs were adsorbed at 1%, 5%, and 10% Fe0 (w/v) concentrations . Little difference in adsorption was found between acidic (2.3) and unamended solutions (pH 5.5), even though significant differences in iron oxidation state and Fe2+ concentrations were measured in solution . PCB adsorption also occurs on steel electrodes regardless of the pH or electric current applied (AC or DC), suggesting the combination of oxidizing (free radical-mediated reactions) and reducing (dechlorination reactions) iron-mediated degradation pathways may be possible . Extraction of the iron powder after 48 h of contact time yielded the progressive recovery of biphenyl with increasing Fe mass(from 0.4% to 3.5%) and changes of the PCB congener-specific pattern as a consequence of dechlorination . A variety of daughter congeners similar to those accumulated during anaerobic microbial dechlorination of Aroclor 1248 in contaminated sediments indicate preferential removal of meta- and para-chlorines.

J Food Prot, 2001 Aug, 64(8), 1128 - 33
Response surface modeling for the inactivation of Escherichia coli O157:H7 on green peppers (Capsicum annuum L.) by chlorine dioxide gas treatments; Han Y et al.; The effects of chlorine dioxide (ClO2) gas concentration (0.1 to 0.5 mg/liter), relative humidity (RH) (55 to 95%), treatment time (7 to 135 min), and temperature (5 to 25 degrees C) on inactivation of Escherichia coli O157:H7 on green peppers were studied using response surface methods . A four-factor, central, composite, rotatable design was used . The microbial log reduction was measured as a response . A direct membrane-surface-plating method with tryptic soy agar and sorbitol MacConkey agar was used to resuscitate and enumerate ClO2-treated E . coli O157:H7 cells . The statistical analysis and the predictive model developed in this study suggest that ClO2 gas concentration, treatment time, RH, and temperature all significantly (P < 0.01) increased the inactivation of E . coli O157:H7 . ClO2 gas concentration was the most important factor, whereas temperature was the least significant . The interaction between ClO2 gas concentration and RH indicated a synergistic effect . The predictive model was validated, and it could be used to determine effective ClO2 gas treatments to achieve a 5-log reduction of E . coli O157:H7 on green peppers.

J Microencapsul, 2001 Sep-Oct, 18(5), 627 - 36
PLGA microsphere bioburden evaluation for radiosterilization dose selection; Geze A et al.; The aim of this study was to determine the bioburden of PLGA microspheres produced by the solvent emulsion/extraction process as a means of determining an appropriate gamma-irradiation dose for sterilization . Bioburden was evaluated on the basis of ISO specifications . The analysis of initial microbial contamination was performed on blank microspheres, prepared by a non-aseptic laboratory scale process . A mean bioburden of 36.04 CFU (colony forming units)/110 mg microspheres was determined . Most of the detected germs originated from human commensal flora . According to the ISO dose-selection method, a gamma-irradiation dose of 19.6 kGy was found sufficient to ensure a sterility level of 10(-6) . The effect of the selected irradiation dose on both the molecular weight of the polymer and the kinetics of 5-fluorouracil drug release from the microspheres was compared to the European Pharmacopeia recommended irradiation dose (25 kGy) . This 20% reduced dose showed a lower extent of molecular weight reduction of PLGA and a better control of 5-FU release from microparticles . This can be related to reduce polymer radiation damage.

Int J Circumpolar Health, 2001 Apr, 60(2), 150 - 6
Moulds, moisture and microbial contamination of First Nations housing in British Columbia, Canada; Lawrence R et al.; This paper reviews the difficulties experienced with mould growth in First Nations homes in British Columbia and to describe the team approach used in dealing with this problem . Humid, damp conditions promote the growth of bacteria, moulds, and dust mites . These organisms contribute to poor air quality and causes serious health problems . There is increasing evidence indicating an association between mould, particularly toxigenic moulds, and some diseases, notably asthma . These health problems usually improve when families are relocated to more suitable accommodation . Those particularly at risk include atopic, immunocompromised, very young and elderly individuals and those with chronic health conditions . Our experience suggests that substandard housing is a major contributor to poor health in First Nations communities.

Huan Jing Ke Xue, 2001 May, 22(3), 97 - 9
{Microbial degradation of polychlorinated dibenzo-p-dioxins}; Du X et al.; PCDDs-degrading bacterial strains were isolated from soil and oxic-sediments polluted by PCDDs . One of them was identified as Pseudomonas sp . EE41 . They are capable of growing on and degrade mono- and di-chlorinated dibenzo-p-dioxins as a sole carbon source . The biodegradability of TrCDD and TCDD can be enhanced through primary nutrient of co-metabolism of o-CDB, thus, 1,2,3-TrCDD and 2,3,7,8-TCDD were degraded by 33% (at the concentration of 1.2 mg/L, within 3 weeks) and 37.8% (at the concentration of 0.1 mg/L, within 3 weeks) respectively . Most highly chlorinated dibenzo-p-dioxins (P-CDD, H6-, H7-CDD and OCDD) tested in this study were accumulated in bacterial cells, but could not be degraded.

Nature, 2001 Aug 16, 412(6848), 701 - 5
Structural mimicry in bacterial virulence; Stebbins CE et al.; An important mechanism underlying the strategies used by microbial pathogens to manipulate cellular functions is that of functional mimicry of host activities . In some cases, mimicry is achieved through virulence factors that are direct homologues of host proteins . In others, convergent evolution has produced new effectors that, although having no obvious amino-acid sequence similarity to host factors, are revealed by structural studies to display mimicry at the molecular level.

J Interferon Cytokine Res, 2001 Jul, 21(7), 485 - 94
IFN-gamma inhibits lipopolysaccharide-induced interleukin-1 beta in primary murine macrophages via a Stat1-dependent pathway; De Boer ML et al.; Interleukin-1 (IL-1) plays an important role in host defenses against microbial pathogens . Excessive production of this cytokine, however, may be responsible in part for the lethality observed during sepsis . Our studies show that interferon-gamma (IFN-gamma) downregulates lipopolysaccharide (LPS)-induced interleukin-1beta (IL-1beta) transcription in primary macrophages . This phenomenon does not occur in splenocytes or bone marrow-derived macrophages from signal transducer and activator of transcription (Stat1)-deficient mice, suggesting that Stat1, a transcription factor involved in IFN signaling, plays a critical role in this process . Moreover, nitric oxide (NO) was also involved in the downregulation of LPS-induced IL-1 by IFN, as addition of the inducible nitric oxide synthase (iNOS) inhibitor L-N(6)-(1-iminoethyl)lysine (NIL) negated the effect . Kinetic analysis of IL-1 and IFN levels in LPS-treated mice in vivo suggests that IFN-mediated inhibition of IL-1 might be an important negative feedback mechanism for limiting IL-1 generation in vivo.

Org Lett, 2001 Aug 23, 3(17), 2677 - 80
Stereoselective synthesis of pseudopeptide microbial agent AI-77-B; Ghosh AK et al.; {structure: see text} . An efficient and highly stereoselective synthesis of the gastroprotective natural product AI-77-B is described . The stereocenters of the hydroxy amino acid moiety were generated by an ester-derived titanium-enolate-mediated syn-aldol reaction, a Curtius rearrangement, and application of Dondoni's aldehyde homologation . Condensation with the dihydroisocoumarin fragment and subsequent deprotecting transformations furnished optically active AI-77-B.

CLAO J, 2001 Jul, 27(3), 125 - 36
Seven-day extended wear and 30-day continuous wear of high oxygen transmissibility soft silicone hydrogel contact lenses: a randomized 1-year study of 504 patients; Nilsson SE; PURPOSE: To compare the performance and complication rates of PureVision (Bausch & Lomb, Inc.) high Dk/t silicone hydrogel lenses in 30-day continuous wear and 7-day extended wear . METHODS: Five-hundred four (504) patients were randomized to 30-day continuous wear (353 patients) or to 7-day extended wear (151 patients) and followed for 12 months . RESULTS: Eighty percent of patients did not report any symptoms/complaints at the follow-up exams . There were no cases of microbial keratitis . The annual incidence of the four most common clinically significant positive slit lamp findings related to lens wear for the 30-day and the 7-day groups, respectively, were as follows: corneal staining, 10.5% and 10.6%; corneal infiltrates, 4.6% and 2.3%; slight epithelial edema, 2.0% and 3.6%; and tarsal conjunctival abnormalities, 1.6% and 3.0% . There was no significant difference in complication rates between the groups . For reasons related to lens wear, 7.6% in the 30-day group and 13.2% in the 7-day group were dropped from the study . The patients' subjective judgment of comfort, visual quality, freedom from dryness, and lens handling varied from 89 to 95 on a scale of 0 to 100 . The success rate was 82.9%, slightly better for the 30-day group (84.4%) than for the 7-day group (79.5%) . CONCLUSION: The complication rate was low . Sight-threatening events, such as bacterial keratitis did not occur . Inflammatory changes were seen, although at a low rate . Anterior segment changes related to hypoxia were minimal . Limbal and bulbar hyperemiadecreased significantly after switching patients to PureVision lenses . There was no significant difference in complication rates between the 30-day group and the 7-day group.

Environ Technol, 2001 Jul, 22(7), 781 - 90
Comparison of two biocides--carbamate and glutaraldehyde--in the control of fouling in pulp and paper industry; Pereira MO et al.; Formation of fouling deposits is a serious problem facing paper mills . Despite the search for alternative methods, chemical biocides still represent the chief countermeasure to control microbial growth and general fouling buid-up in pulp and paper mills . The purpose of this work was to determine the effect of two biocides (carbamate and glutaraldehyde) on both planktonic cells and fouling layers of a paper machine system . A flow system was used for the study of fouling accumulation in an industrial white water circuit . Both biocides proved to be more effective in reducing the microbial loading of the white water circuit than the deposit accumulated on the stainless steel surfaces . Carbamate, in contrast to glutaraldehyde, had the ability of promoting cell agglomeration since the microbial loading decreased much more when the white water, treated with carbamate, was filtered through a filter-linen . The retention of suspended cells in the cellulose fibres acquires major importance since it is obtained by using an already existing physical process (filtration), which strongly enhances the overall microbial reduction obtained with the addition of the carbamate, without increasing the economic costs . These results also suggest that the use of conventional retention agents in pulp and paper processes can be efficient in controlling unwanted microbial effects.

J Clin Immunol, 2001 Jul, 21(4), 286 - 92
Altered expression of L-selectin (CD62L) on polymorphonuclear neutrophils of children vertically infected with human immunodeficiency virus type 1; Meddows-Taylor S et al.; The expression of the leukocyte adhesion molecule L-selectin (CD62L) on polymorphonuclear neutrophils (PMN) and circulating levels of the soluble form of the receptor (sCD62L) were determined for a group of HIV-1-infected children, categorized as having mild or severe disease, and a group of uninfected control children . The fluorescence intensity of CD62L on PMN was significantly reduced in the HIV-1-infected children with mild disease compared to the uninfected controls . The proportion of lymphocytes expressing CD62L, as well as their corresponding fluorescence intensities, was significantly reduced in both the mild and the severe disease groups compared to the uninfected children, while peripheral levels of sCD62L were significantly elevated in the HIV-1-infected children with mild and severe disease compared to the controls . Altered cell migration resulting from reduced expression of CD62L may be an important contributor to the increased susceptibility to secondary microbial infections seen in HIV-1-infected children.

Environ Sci Technol, 2001 Aug 1, 35(15), 3169 - 74
Chromium diffusion and reduction in soil aggregates; Tokunaga TK et al.; The distribution of metal contaminants such as chromium in soils can be strongly localized by transport limitations and redox gradients within soil aggregates . Measurements of Cr(VI) diffusion and reduction to Cr(III) were obtained in soil columns representing transects into soil aggregates in order to quantify influences of organic carbon (OC) and redox potentials on Cr transport distances and microbial community composition . Shifts in characteristic redox potentials, and the extent of Cr(VI) reduction to Cr(III) were related to OC availability . Depth profiles of Cr(VI, III) obtained with micro X-ray absorption near edge structure (micro-XANES) spectroscopy reflected interdependent effects of diffusion and spatially dependent redox potentials on reduction kinetics and microbial community composition . Shallow diffusion depths (2-10 mm) and very sharply terminated diffusion fronts in columns amended with OC (80 and 800 ppm) reflected rapid increases in Cr reduction kinetics over very short (mm) distances . These results suggest that Cr contamination in soils can be restricted to the outsides of soil aggregates due to localized transport and rapid reduction and that bulk sample characterization is inadequate for understanding the controlling biogeochemical processes.

Bioorg Med Chem, 2001 Aug, 9(8), 1985 - 92
Microbial and reducing agents catalyze the rearrangement of taxanes; Sun DA et al.; 5alpha, 7beta, 9alpha, 10beta, 13alpha-Pentahydroxy-4(20),11(12)-taxadiene derivative 1 was converted to two unprecedented 1(15-->11)abeo-taxanes and a taxane derivative with a C10-C11 double bond by Absidia coerula ATCC 10738a . A similar compound was obtained from treatment with zinc of a triacetoxy-4(20),11(12)-taxadiene derivative.

Cell Mol Biol (Noisy-le-grand), 2001 Jun, 47(4), 637 - 51
Role of interleukin-13 in innate and adaptive immunity; Brubaker JO et al.; Initially thought to be functionally redundant with IL-4 as a predominant anti-inflammatory factor secreted during type-2 T-cell responses, IL-13 possesses a number of additional properties that distinguish it from IL-4 in addition to having both anti-inflammatory and immune activating properties . This review centers primarily on the role of IL-13 in the regulation of cellular functions of innate immunity and acquired immunity against certain microbial pathogens . First, we discuss IL-13's regulation of innate cell targets and its impact on inflammation, antigen uptake and antigen presentation . Second, we focus on IL-13's involvement in acquired immunity to infectious helminths and protozoa . The role of this cytokine in immune responses is still being determined but evidence to date suggests this molecule has been conserved as an important regulatory factor involved in both early innate and late adaptive responses.

Acta Odontol Scand, 2001 Jun, 59(3), 154 - 60
Clinical, pathological and immunological aspects of periodontal disease; Kinane DF et al.; The inflammatory and immune responses during the development and progression of periodontitis are reviewed . Susceptibility to periodontitis may be related to whether plasma cells predominate in the tissues of an individual, or a site, in response to the microbial insult from dental plaque . The tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogenic bacteria and thus a predisposition to periodontitis . Selected pertinent areas of current interest in cellular and humoral immunology are considered within the periodontal context . These topical issues include (a) homing of immune and inflammatory cells to target tissues; (b) the local proliferation and synthetic activity of immune and inflammatory cells; (c) the cytokine profile of the inflammatory and immune cells; and (d) the immunoglobulin subclasses of locally produced antibodies.

Acta Odontol Scand, 2001 Jun, 59(3), 145 - 53
The mucosal immune system: from specialized immune defense to inflammation and allergy; Kiyono H et al.; The mucosal immune system is a first line of defense against foreign antigens, including microbial and dietary antigens . Under normal circumstances, the mucosal immune system employs tightly regulated dynamic mucosal intra- and internets consisting of inductive and effector sites for the induction of an appropriate immunological homeostasis between the host and mucosal environments . The common mucosal immune system (CMIS), which interconnects between inductive (e.g . Peyer patch) and effector (e.g . intestinal lamina propria) tissues for the induction of the IgA response, is well characterized . Recent results provide strong evidence for the presence of a CMIS-independent IgA induction pathway . Two distinct subsets of mucosal IgA-committed B cells termed B-1 and B-2, are associated with CMIS-independence and CMIS-dependent cascades respectively . In some cases, the breakdown of this tightly regulated mucosal immune system leads to pathological responses to different gut environmental antigens . As a result, disorders such as inflammatory bowel disease (e.g . IBD) and allergic gastroenteropathy can be evoked in the gastrointestinal tissues . Recently, many studies have described possible molecular and cellular mechanisms for this dysfunction in the gastrointestinal tissues by using murine models with specific gene manipulation . In this review we summarize recent findings from our group concerning the CMIS-dependent and CMIS-independent IgA induction pathways and gastrointestinal diseases (IBD and intestinal allergic diseases) . These observations may provide useful information for the development of new mucosal immune therapy.

Folia Microbiol (Praha), 2001, 46(1), 53 - 5
Application of flow cytometry for ecological monitoring of the rumen microbial ecosystem; Lipoglavsek L et al.; Flow cytometry in combination with fluorescently labeled ribosomal RNA oligonucleotide probes was used for enumeration and monitoring of ruminal bacteria . The polyanionic azo dye Trypan Blue was used for discrimination between live bacterial cells and inorganic particles and the separation was further improved by lysozyme treatment and sonication . Cy3-labeled universally conserved probe EUB338 and FITC-labeled Prevotella bryantii specific probe PBB14 were used for in situ hybridization in mixed culture experiments and in samples of crude rumen fluid . The results were analyzed by flow cytometry . The separation of P . bryantii and Butyrivibrio fibrisolvens, another ruminal bacterium, in mixed culture experiments was satisfactory and enabled monitoring of these bacteria in a test system . P . bryantii cells were detected in crude rumen fluid samples only after supplementation with pure culture cells; this implicates a low concentration of P . bryantii cells in vivo (less than 100/nL, i.e . 10(5) per mL).

Plant Physiol, 2001 Aug, 126(4), 1598 - 608
A novel phytase with sequence similarity to purple acid phosphatases is expressed in cotyledons of germinating soybean seedlings; Hegeman CE et al.; Phytic acid (myo-inositol hexakisphosphate) is the major storage form of phosphorus in plant seeds . During germination, stored reserves are used as a source of nutrients by the plant seedling . Phytic acid is degraded by the activity of phytases to yield inositol and free phosphate . Due to the lack of phytases in the non-ruminant digestive tract, monogastric animals cannot utilize dietary phytic acid and it is excreted into manure . High phytic acid content in manure results in elevated phosphorus levels in soil and water and accompanying environmental concerns . The use of phytases to degrade seed phytic acid has potential for reducing the negative environmental impact of livestock production . A phytase was purified to electrophoretic homogeneity from cotyledons of germinated soybeans (Glycine max L . Merr.) . Peptide sequence data generated from the purified enzyme facilitated the cloning of the phytase sequence (GmPhy) employing a polymerase chain reaction strategy . The introduction of GmPhy into soybean tissue culture resulted in increased phytase activity in transformed cells, which confirmed the identity of the phytase gene . It is surprising that the soybean phytase was unrelated to previously characterized microbial or maize (Zea mays) phytases, which were classified as histidine acid phosphatases . The soybean phytase sequence exhibited a high degree of similarity to purple acid phosphatases, a class of metallophosphoesterases.

Infect Immun, 2001 Sep, 69(9), 5270 - 7
Potent stimulation of the innate immune system by a Leishmania brasiliensis recombinant protein; Borges MM et al.; The interaction of the innate immune system with the microbial world involves primarily two sets of molecules generally known as microbial pattern recognition receptors and microbial pattern recognition molecules, respectively . Examples of the former are the Toll receptors present particularly in macrophages and dendritic cells . Conversely, the microbial pattern recognition molecules are conserved protist homopolymers, such as bacterial lipopolysaccharides, lipoteichoic acids, peptidoglycans, glucans, mannans, unmethylated bacterial DNA, and double-strand viral RNA . However, for protists that lack most of these molecules, such as protozoans, the innate immune system must have evolved receptors that recognize other groups of microbial molecules . Here we present evidence that a highly purified protein encoded by a Leishmania brasiliensis gene may be one such molecule . This recombinant leishmanial molecule, a homologue of eukaryotic ribosomal elongation and initiation factor 4a (LeIF), strongly stimulates spleen cells from severe combined immunodeficient (SCID) mice to produce interleukin-12 (IL-12), IL-18, and high levels of gamma interferon . In addition, LeIF potentiates the cytotoxic activity of the NK cells of these animals . Because LeIF is a conserved molecule and because SCID mice lack T and B lymphocytes but have a normal innate immune system (normal reticuloendothelial system and NK cells), these results suggest that proteins may also be included as microbial pattern recognition molecules . The nature of the receptor involved in this innate recognition is unknown . However, it is possible to exclude the Toll receptor Tlr4 as a putative LeIF receptor because the gene encoding this receptor is defective in C3H/HeJ mice, the mouse strain used in the present studies.

J Invertebr Pathol, 2001 Jul, 78(1), 1 - 8
Adult survival, maturation, and reproduction of the desert locust Schistocerca gregaria infected with the fungus Metarhizium anisopliae var acridum; Blanford S et al.; Studies were conducted with two different doses of Metarhizium anisopliae var acridum to examine the effects on survival and reproductive potential of adult Schistocerca gregaria under conditions that either limited thermoregulation or enabled optimal thermoregulation . Adult S . gregaria infected with the fungal pathogen showed either a rapid and high mortality at relatively constant temperatures or a much reduced mortality and lengthened survival time when allowed to thermoregulate . Mortality rate varied from >90% after 10 days under constant temperature conditions to 66% after 70 days under optimal thermoregulatory conditions . Effects of infection on maturation and reproduction depended on the age of the adults at the time of inoculation, the nighttime temperature regime, the fungal dose, and the length of time of the monitoring period . No difference in reproductive behaviors in treated and control insects were found in one experiment that utilized older adults and was conducted over 25 days . In a second experiment with newly fledged locusts, differences in maturation rates and total reproductive output were observed due to infection . The results from these experiments are discussed in terms of the potential of M . anisopliae var acridum to alter the balance of insect endocrine systems and the importance of the assessment of behavioral changes and their impact on microbial control agents in the long term .

Curr Opin Immunol, 2001 Aug, 13(4), 471 - 8
CD1-specific T cells in microbial immunity; Gumperz JE et al.; Recent results strengthen evidence that CD1-restricted T cells play important roles in host defense against microbial infections . Human subjects recently infected with Mycobacterium tuberculosis showed elevated responses to CD1c-mediated presentation of a microbial lipid antigen, compared with control donors . Activation of CD1d-restricted NKT cells with a synthetic glycolipid antigen results in improved immune responses to several infectious pathogens.

Biochem Soc Trans, 2001 Aug, 29(Pt 4), 598 - 601
Why and how are peptide-lipid interactions utilized for self defence?
Matsuzaki K.
Animals defend themselves against invading pathogenic micro-organisms by utilizing cationic anti-microbial peptides, which rapidly kill various micro-organisms without exerting toxicity against the host . Physicochemical peptide-lipid interactions provide attractive mechanisms for innate immunity . Many of these peptides form amphipathic secondary structures (alpha-helices and beta-sheets) which can selectively interact with anionic bacterial membranes by electrostatic interaction . Rapid, peptide-induced membrane permeabilization is an effective mechanism of anti-microbial action . Magainin 2 from frog skin forms a dynamic peptide-lipid supramolecular-complex pore that allows mutually coupled transmembrane transport of ions and lipids . The peptide molecule is internalized upon the disintegration of the pore . Several anti-microbial peptides are known to work synergistically.

Eur J Clin Pharmacol, 2001 Jun, 57(3), 211 - 9
Microdialysis . A novel tool for clinical studies of anti-infective agents; Joukhadar C et al.; In vivo microdialysis (MD) is an innovative clinical technique that has been employed in preclinical research and metabolic studies in patients for more than a decade . Recently, MD has been adopted for human drug studies and has opened up the opportunity to quantify tissue drug distribution in vivo . The particular advantage of MD for the anti-infective field relates to the fact that MD allows for online measurement of the unbound, pharmacologically active drug fraction in the interstitial space fluid (ISF), the anatomically defined target site for most bacterial infections . The aim of this review is to provide an overview of the current literature about MD in anti-microbial drug studies . It will be shown that MD has become feasible in most human tissues including brain and lung . So far, several MD studies have demonstrated that anti-microbial concentrations at the effect site may be subinhibitory, although effective concentrations are attained in serum, a finding that has significant impact on clinical decision making . In addition to its property as a pharmacokinetic sampling technique, MD offers unique opportunities in pharmacokinetic-pharmacodynamic (PK-PD) research and has the potential to streamline the decision process on proper drug dosing in drug development.

Regul Pept, 2001 Sep 15, 101(1-3), 157 - 61
Human alpha-defensin 1 (HNP-1) inhibits adenoviral infection in vitro; Bastian A et al.; Adenoviral gene transfer is a promising tool for direct treatment of cystic fibrosis by local application of the CFTR-gene via the airway . However, various host defense mechanisms reduce the adenoviral infectivity and hereby the success of adenoviral transduction . Twenty-eight of 62 BALs from various patients exerted strong inhibition of adenoviral infection of 293 cells . This soluble activity could be attributed to larger peptides rather than to small molecules . Beside immunoglobulins, certain epithelial cell-derived anti-microbial polypeptides called defensins might be involved . Therefore, we investigated the inhibitory potential of the defensins HNP-1 and HBD-2 on adenoviral infectivity . 293 cells infected with adenovirus-type 5 were treated with both peptides . Compared to control, HNP-1 reduced adenoviral infection by more than 95% if administered at 50 microg/ml, and the IC50-value was 15 microg/ml . In contrast, HBD-2 was much less efficient and did not block adenoviral infection at doses up to 50 microg/ml . Our data demonstrate that the presence of certain polypeptides in the BAL, i.e . the defensin HNP-1, might be the major obstacle for adenoviral gene transfer, particularly in patients with inflammatory diseases.

Am J Ind Med, 2001 Aug, 40(2), 199 - 210
Medical aspects of global warming; Yoganathan D et al.; BACKGROUND: Global warming is caused by increased carbon dioxide (CO2)resulting in a greenhouse effect with enhanced warming of the earth . Measurements of CO2 show a steady increase over the past 30 years caused by the burning of fossil fuels and from the loss of natural CO2 sinks . A 100-year increase in global temperature by 0.3 to 0.6 degrees C is reflected in atmospheric warming, glacier shrinkage, and rising sea levels . OBJECTIVES: Planetary ecosystem dynamics are being altered, challenging public health . It is predicted that morbidity and mortality will increase as a result of heat stress, as seen in recent heat waves in the U.S . Weather disaster effects will increase in number and magnitude, and both noninfectious and infectious diseases may flourish . A significant challenge will be the changes in life cycles of microbial species due to the warmer environs . Specific increases in incidence have been noted for vector-borne diseases, in addition to pulmonary findings, cardiovascular morbidity, neurological diseases, and occupational diseases . CONCLUSIONS: Warming can be demonstrated by the observed changes that have already occurred in the environment, particularly the thinning of polar ice caps . The United States Global Research Program has been established to coordinate research activities, which responds to issues deemed important by the United Nations Framework Convention on Climate Change . Research issues pertain to the scientific uncertainties in the greenhouse effect, temperature measurements at various atmospheric levels and latitudes, and impact on biota redistribution . The Kyoto Protocol has mandated specific solutions, e.g., a 7% reduction in CO2 levels within 10 years . Future recommendations involve supporting new technologies that are available to decrease emissions as well as understanding the role that occupational and environmental specialists have in global warming recognition .

Proc Natl Acad Sci U S A, 2001 Aug 14, 98(17), 9853 - 8 Epub 2001 Aug 07.
DNA/DNA hybridization to microarrays reveals gene-specific differences between closely related microbial genomes; Murray AE et al.; DNA microarrays constructed with full length ORFs from Shewanella oneidensis, MR-1, were hybridized with genomic DNA from nine other Shewanella species and Escherichia coli K-12 . This approach enabled visualization of relationships between organisms by comparing individual ORF hybridizations to 164 genes and is further amenable to high-density high-throughput analyses of complete microbial genomes . Conserved genes (arcA and ATP synthase) were identified among all species investigated . The mtr operon, which is involved in iron reduction, was poorly conserved among other known metal-reducing Shewanella species . Results were most informative for closely related organisms with small subunit rRNA sequence similarities greater than 93% and gyrB sequence similarities greater than 80% . At this level of relatedness, the similarity between hybridization profiles was strongly correlated with sequence divergence in the gyrB gene . Results revealed that two strains of S . oneidensis (MR-1 and DLM7) were nearly identical, with only 3% of the ORFs hybridizing poorly, in contrast to hybridizations with Shewanella putrefaciens, formerly considered to be the same species as MR-1, in which 63% of the ORFs hybridized poorly (log ratios below -0.75) . Genomic hybridizations showed that genes in operons had consistent levels of hybridization across an operon in comparison to a randomly sampled data set, suggesting that similar applications will be informative for identification of horizontally acquired genes . The full value of microbial genomic hybridizations lies in providing the ability to understand and display specific differences between closely related organisms providing a window into understanding microheterogeneity, bacterial speciation, and taxonomic relationships.

J Med Primatol, 2001 Apr, 30(2), 127 - 30
Subcutaneous hemangiosarcomas in a rhesus macaque (Macaca mulatta); Myers DD Jr et al.; Hemangiosarcoma is a malignant tumor of vascular endothelial cell origin . The occurrence of hemangiosarcoma in nonhuman primates has been rarely documented . An adult male rhesus monkey was reported having a firm subcutaneous swelling, approximately 4.5 cm in diameter, on the ventral midline of the abdomen . Fine-needle aspiration, microbial culture, biopsy, radiographs, exploratory laparotomy, histopathology, immunohistochemistry, hematology, and serology were performed . A second subcutaneous mass approximately 4.5 x 4.0 x 2.7 cm developed on the ventral midline several weeks later . A fine-needle aspirate of the first mass consisted of numerous erythrocytes with few polymorphonuclear cells and lymphocytes . Histopathology showed foci of spindle-shaped cells surrounding the vascular spaces . Many spindle-shaped cells had prominent nucleoli, and mitotic figures could occasionally be seen . Immunohistochemical staining of the masses for Factor VIII-related antigen, an endothelial cell and tumor marker, yielded positive results . Both masses were consistent with hemangiosarcoma.

J Immunol, 2001 Aug 15, 167(4), 2411 - 7
Down-regulation of IgE and IgG4 antibodies to tetanus toxoid and diphtheria toxoid by covaccination with cellular Bordetella pertussis vaccine; Gruber C et al.; Pertussis (P) toxin acts as adjuvant for IgE formation against simultaneously administered Ags in animal models . P vaccination may also have an adjuvant impact on IgE formation against coadministered diphtheria (D) and tetanus (T) Ags in humans . Sera of 103 D-T-P-immunized and 319 D-T-immunized children aged 2 years were analyzed for IgE, IgG4, and IgG to D and T (radioallergosorbent test), total IgE and IgE against common inhalant allergens (CAP radioallergosorbent test fluoroenzyme immunoassay) . Fewer D-T-P- than D-T-immunized children had sera positive for T-IgE (12.6 vs 53.6%, p < 0.001), T-IgG4 (71.6 vs 89.2%, p < 0.001), D-IgE (31.0 vs 70.5%, p < 0.001), and D-IgG4 (85.2 vs 93.4%, p = 0.039) . Suppression of T-IgE was not dependent on the cutoff chosen for a positive test result, but was dependent on the proportion of D-T immunizations given with P . The risk for sensitization to common environmental allergens did not differ (odds ratio 0.953, 95% confidence interval 0.815-1.114) . No significant differences between D-T- and D-T-P-immunized children were found with regard to T-IgG or D-IgG . In summary, IgE and IgG4 (but not IgG) serum levels to coadministered D- and T-Ags are suppressed among P-immunized children as compared with nonimmunized children . These results suggest that the presence of a microbial product during Ag exposure can down-regulate an IgE/IgG4 response in humans.

J Immunol, 2001 Aug 15, 167(4), 2193 - 201
Toxoplasma gondii tachyzoites inhibit proinflammatory cytokine induction in infected macrophages by preventing nuclear translocation of the transcription factor NF-kappa B; Butcher BA et al.; Control of microbial infection requires regulated induction of NF-kappaB-dependent proinflammatory cytokines such as IL-12 and TNF-alpha . Activation of this important transcription factor is driven by phosphorylation-dependent degradation of the inhibitory IkappaB molecule, an event which enables NF-kappaB translocation from the cytoplasm to the nucleus . In this study, we show that intracellular infection of macrophages with the protozoan parasite Toxoplasma gondii induces rapid IkappaB phosphorylation and degradation . Nevertheless, NF-kappaB failed to translocate to the nucleus, enabling the parasite to invade cells without triggering proinflammatory cytokine induction . Infected cells subsequently subjected to LPS triggering were severely crippled in IL-12 and TNF-alpha production, a result of tachyzoite-induced blockade of NF-kappaB nuclear translocation . Our results are the first to demonstrate the ability of an intracellular protozoan to actively interfere with the NF-kappaB activation pathway in macrophages, an activity that may enable parasite survival within the host.

J Clin Invest, 2001 Aug, 108(3), 485 - 93
Plasma CD14 decreases monocyte responses to LPS by transferring cell-bound LPS to plasma lipoproteins; Kitchens RL et al.; CD14, a myeloid cell-surface receptor and soluble plasma protein, binds LPS and other microbial molecules and initiates the innate immune response to bacterial invasion . The blood concentration of soluble CD14 (sCD14) increases during the systemic response to infection . Although high sCD14 blood levels have correlated with increased risk of dying from severe sepsis, sCD14 can diminish cell responses to LPS . We show here that in human serum, sCD14 increases the rate at which cell-bound LPS is released from the monocyte surface and binds to plasma lipoproteins . This enhanced rate of LPS efflux is associated with a significant reduction in the ability of monocytes to produce cytokines in response to LPS . Serum from septic patients reduced the LPS-monocyte interaction by as much as tenfold, and depletion of sCD14 from the serum restored LPS-monocyte binding and release kinetics to near normal levels . In serum from septic patients, monocyte-bound LPS also moved more rapidly into lipoproteins, which completely neutralized the biologic activity of the LPS that bound to them . In human plasma, sCD14 thus diminishes monocyte responses to LPS by transferring cell-bound LPS to lipoproteins . Stress-related increases in plasma sCD14 levels may help prevent inflammatory responses within the blood.

Anal Biochem, 2001 Aug 15, 295(2), 129 - 37
Quantification of intracellular metabolites in Escherichia coli K12 using liquid chromatographic-electrospray ionization tandem mass spectrometric techniques; Buchholz A et al.; The quantitative comprehension of microbial metabolic networks is a prerequisite for an efficient rational strain improvement ("metabolic engineering") . It is therefore necessary to accurately determine the concentration of a large number of reactants (i.e., metabolites, nucleotides, cofactors) in order to understand "in vivo" reaction kinetics . Quantification of intracellular concentrations of glycolytic intermediates and nucleotides in Escherichia coli K12 using a perchloric acid extraction and an LC-ESI-MS method was achieved . Intracellular metabolites (e.g., glucose 6-phosphate, fructose 1,6-bisphosphate, 6-phospho gluconate, acetyl-CoA, adenine nucleotides) were quantified under defined (glucose-limited steady-state) growth conditions . The method was verified by comparing the intracellular metabolite concentrations measured via LC-ESI-MS with enzymatic determinations . It is thus possible to identify and quantify more than 15 intracellular metabolites in parallel with a minimal amount of sample volume .

Arch Biochem Biophys, 2001 Aug 15, 392(2), 279 - 86
Characterization of a novel laccase produced by the wood-rotting fungus Phellinus ribis; Min KL et al.; The white-rot fungus Phellinus ribis produced a single form of laccase, which was purified to apparent electrophoretic homogeneity from cultures induced with 2,5-xylidine . This protein was a dimer, consisting of two subunits of 76 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . Carbohydrate analysis revealed that the enzyme contained about 28% carbohydrate content . The laccase appeared to be different from other known laccases by the UV-visible absorption spectrum analysis . One enzyme molecule contained one copper, one manganese, and two zinc atoms . The laccase showed optimal activity at pH 4.0-6.0, 5.0, and 6.0 with 2,6-dimethoxyphenol, ABTS {2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)}, and syringaldazine, respectively . The enzyme preferably oxidized dimethoxyphenol and aromatic amine compounds . The stability of the laccase was low at acidic pH, whereas it showed high stability at neutral pH and mild temperature . The N-terminal amino acid sequence revealed a very low homology with other microbial laccases . With some substrates, the addition of manganese and H2O2 resulted in a remarkable increase in the oxidation rate . Without an appropriate phenolic substrate, the enzyme could not oxidize Mn(II) in the presence of H2O2 or pyrophosphate .

Front Biosci, 2001 Aug 01, 6, D944 - 53
The structure and functions of human lysophosphatidic acid acyltransferases; Leung DW; Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are two phospholipids involved in signal transduction and in lipid biosynthesis in cells . LPA acyltransferase (LPAAT), also known as 1-acyl sn-glycerol-3-phosphate acyltransferase (1-AGPAT) (EC 2.3.1.51), catalyzes the conversion of LPA to PA . Two human isoforms of LPAAT, designated as LPAAT-alpha (AGPAT1) and LPAAT-beta (AGPAT2), have been extensively characterized . These two proteins contain extensive sequence similarities to microbial, plant and animal LPAAT sequences . LPAAT-alpha mRNA is uniformly expressed throughout most tissues with the highest level found in skeletal muscle; whereas LPAAT-beta is differentially expressed, with the highest level found in heart and liver, and negligible level in brain and placenta . The LPAAT-alpha gene is located on chromosome 6p21.3, an area within the class III region of the major hiscompatibility complex (MHC) and the LPAAT-beta gene is mapped to chromosome 9q34.3 . Enhanced transcription of LPAAT-beta is suggested for neoplasm of the female genital tract . Additionally, ectopic LPAAT expression in certain cytokine-responsive cell lines can effect amplification of cellular signaling processes, such as those leading to enhancement of synthesis of tumor necrosis factor-alpha and interleukin-6 from cells following stimulation with interleukin-1beta; this suggests that the LPAAT genes represent candidates for affecting the development of certain cancers or inflammation-associated diseases.

Biodegradation, 2000, 11(5), 323 - 9
Degradation of microbial polyester poly(3-hydroxybutyrate) in environmental samples and in culture; Manna A et al.; Poly(3-hydroxybutyrate) {P(3HB)} test-pieces prepared from the polymer produced by Azotobacter chroococcum were degraded in natural environments like soil, water, compost and sewage sludge incubated under laboratory conditions . Degradation in terms of % weight loss of the polymer was maximum (45%) in sewage sludge after 200 days of incubation at 30 degrees C . The P(3HB)-degrading bacterial cultures (36) isolated from degraded test-pieces showed different degrees of degradation in polymer overlayer method . The extent of P(3HB) degradation increases up to 12 days of incubation and was maximum at 30 degrees C for majority of the cultures . For most efficient cultures the optimum concentration of P(3HB) for degradation was 0.3% (w/v) . Supplementation of soluble carbon sources like glucose, fructose and arabinose reduced the degradation while it was almost unaffected with lactose . Though the cultures degraded P(3HB) significantly, they were comparatively less efficient in utilizing copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate {P(3HB-co-3HV)}.

Biodegradation, 2000, 11(5), 313 - 21
Quinones as terminal electron acceptors for anaerobic microbial oxidation of phenolic compounds; Cervantes FJ et al.; The capacity of anaerobic granular sludge for oxidizing phenol and p-cresol under anaerobic conditions was studied . Phenol and p-cresol were completely converted to methane when bicarbonate was the only terminal electron acceptor available . When the humic model compound, anthraquinone-2,6-disulfonate, was included as an alternative electron acceptor in the cultures, the oxidation of the phenolic compounds was coupled to the reduction of the model humic compound to its corresponding hydroquinone, anthrahydroquinone-2,6-disulfonate . These results demonstrate for the first time that the anaerobic degradation of phenolic compounds can be coupled to the reduction of quinones as terminal electron acceptor.

Pediatr Pathol Mol Med, 2001 Jul-Aug, 20(4), 293 - 318
Functional mapping of surfactant protein A; McCormack FX; Surfactant protein A (SP-A) is a highly ordered, oligomeric glycoprotein that is secreted into the airspaces of the lung by alveolar type II cells and Clara cells of the pulmonary epithelium . Although research has shown that SP-A is both a calcium-dependent phospholipid-binding protein that affects surfactant structure and function and a lectin that opsonizes diverse microbial species, our understanding of the physiologically relevant roles of SP-A in the lung remains incomplete . My review focuses on the putative biological functions of SP-A that are supported by experiments in mammals and on the structural basis of SP-A function.

Circ Res, 2001 Aug 3, 89(3), 244 - 50
Chlamydia pneumoniae and chlamydial heat shock protein 60 stimulate proliferation of human vascular smooth muscle cells via toll-like receptor 4 and p44/p42 mitogen-activated protein kinase activation; Sasu S et al.; An early component of atherogenesis is abnormal vascular smooth muscle cell (VSMC) proliferation . The presence of Chlamydia pneumoniae in many atherosclerotic lesions raises the possibility that this organism plays a causal role in atherogenesis . In this study, C pneumoniae elementary bodies (EBs) rapidly activated p44/p42 mitogen-activated protein kinases (MAPKs) and stimulated proliferation of VSMCs in vitro . Exposure of VSMCs derived from human saphenous vein to C pneumoniae EBs (3x10(7) inclusion forming units/mL) enhanced bromodeoxyuridine (BrdU) incorporation 12+/-3-fold . UV- and heat-inactivated C pneumoniae EBs also stimulated VSMC proliferation, indicating a role of direct stimulation by chlamydial antigens . However, the mitogenic activity of C pneumoniae was heat-labile, thus excluding a role of lipopolysaccharide . Chlamydial hsp60 (25 microg/mL) replicated the effect of C pneumoniae, stimulating BrdU incorporation 7+/-3-fold . Exposure to C pneumoniae or chlamydial hsp60 rapidly activated p44/p42 MAPK, within 5 to 10 minutes of exposure . In addition, PD98059 and U0126, which are two distinct inhibitors of upstream MAPK kinase 1/2 (MEK1/2), abolished the mitogenic effect of C pneumoniae and chlamydial hsp60 . Toll-like receptors (TLRs) act as sensors for microbial antigens and can signal via the p44/p42 MAPK pathway . Human VSMCs were shown to express TLR4 mRNA and protein, and a TLR4 antagonist abolished chlamydial hsp60-induced VSMC proliferation and attenuated C pneumoniae-induced MAPK activation and VSMC proliferation . Together these results indicate that C pneumoniae and chlamydial hsp60 are potent inducers of human VSMC proliferation and that these effects are mediated, at least in part, by rapid TLR4-mediated activation of p44/p42 MAPK.

Am J Pathol, 2001 Aug, 159(2), 537 - 46
cis Interaction of the cell adhesion molecule CEACAM1 with integrin beta(3); Brummer J et al.; CEACAM1 is a cell adhesion molecule that has been implicated in a number of physiological processes (eg, tumor suppressor in epithelial tissues, potent angiogenic factor in microvessel formation, microbial receptor in human granulocytes and epithelial cells) . The mechanism of CEACAM1 action is still largely unresolved but recent findings demonstrated that the cytoplasmic CEACAM1 domain is linked indirectly to the actin-based cytoskeleton . We have isolated integrin beta(3) as an associated protein using CEACAM1 tail affinity purification . This association depends on phosphorylation of Tyr-488 in the CEACAM1 cytoplasmic domain . Confocal laser scanning microscopy confirmed in vivo colocalization of both molecules in human granulocytes and epithelial cells . Furthermore, the concentrated colocalization at the tumor-stroma interface of invading melanoma masses suggests a functional role of CEACAM1-integrin beta(3) interaction in melanoma invasion . Moreover, colocalization of the two adhesion molecules is also found at the apical surface of glandular cells of pregnancy endometrium . Colocalization of CEACAM1 and integrin beta(3) at the transitional zone from proliferative to invasive extravillous trophoblast of the maternal-fetal interface supports a role for CEACAM1/integrin beta(3) complexes in cell invasion.

Trends Genet, 2001 Aug, 17(8), 429 - 31
Intrinsic errors in genome annotation; Devos D et al.; Genome sequencing is usually followed by routine annotation of protein function based on the assumption that similar sequences will have similar functions . Here, we introduce a simple calculation to estimate the magnitude of any possible annotation errors . We counted the number of discrepancies in the annotation of well-established sets of similar proteins and extrapolated these values to the pairs of similar sequences used for the annotation of different microbial genomes . We conclude that the number of potential errors in the prediction of detailed functions is higher than is usually believed.

Immunity, 2001 Jul, 15(1), 127 - 35
MASP-3 and its association with distinct complexes of the mannan-binding lectin complement activation pathway; Dahl MR et al.; The mannan-binding lectin (MBL) pathway of complement activation is part of the innate immune defense . The binding of MBL to microbial carbohydrates activates the MBL-associated serine proteases (MASPs), which recruit the complement factors, C4 and C2, to generate the C3 convertase or directly activate C3 . We present a phylogenetically highly conserved member of the MBL complex, MASP-3, which is generated through alternative splicing of the MASP-1/3 gene . The designation of MASP-3 as a protease is based on homology to known MASPs . Different MBL oligomers were found to have distinct MASP composition and biological activities . MASP-1, MAp19, and direct C3-cleaving activity are associated with smaller oligomers whereas MASP-3 is found together with MASP-2 on larger oligomers . MASP-3 downregulate the C4 and C2 cleaving activity of MASP-2.

Biochem Biophys Res Commun, 2001 Aug 10, 286(1), 87 - 93
Regulation of protein kinase CKII by direct interaction with the C-terminal region of p47(phox); Kim YS et al.; Protein kinase CKII is a Ser/Thr kinase which is involved in many proliferation-related processes in the cell . p47(phox) is a component of the leukocyte NADPH oxidase, which is an important element of host defense against microbial infection . In this study, we demonstrate that a truncated form of the p47(phox) lacking its N-terminal region (p47(phox)/SH3-C), but not a truncated form of the p47(phox) lacking its C-terminal region (p47(phox)/N-SH3), undergoes better phosphorylation by CKII in the presence of arachidonic acid . The yeast two-hybrid test and the glutathione S-transferase (GST) pull-down assay showed that p47(phox) interacts specifically with the regulatory beta subunit (CKIIbeta), but not with the catalytic alpha subunit (CKIIalpha) of the tetrameric CKII holoenzyme . The binding of p47(phox) to CKIIbeta requires the C-terminal region of p47(phox) and is completely abolished by addition of spermine, indicating that a highly basic region in the C-terminal region of p47(phox) contributes to binding to CKIIbeta . In addition, p47(phox) stimulates the catalytic activity of CKII holoenzyme; this stimulation also requires the C-terminal region of p47(phox) . Coimmunoprecipitation experiments showed that CKII holoenzyme interacts with p47(phox) in human neutrophils . Taken together, the present data indicate that the C-terminal region of p47(phox) plays a significant role in the arachidonic acid-dependent phosphorylation of p47(phox) by CKII and that the same region of p47(phox) associates directly with CKIIbeta and can modulate the catalytic activity of CKII holoenzyme .

Nat Rev Mol Cell Biol, 2001 Aug, 2(8), 578 - 88
Pathogenic trickery: deception of host cell processes; Knodler LA et al.; Microbial pathogens cause a spectrum of diseases in humans . Although the disease mechanisms vary considerably, most pathogens have developed virulence factors that interact with host molecules, often usurping normal cellular processes, including cytoskeletal dynamics and vesicle targeting . These virulence factors often mimic host molecules, and mediate events as diverse as bacterial invasion, antiphagocytosis, and intracellular parastism.

Biologicals, 2001 Mar, 29(1), 39 - 43
Development of control serum for microbial antibody tests; Uemura Y et al.; Control sera are an essential component of in-vitro clinical diagnostic reagents . We have developed a control serum for HBsAg, anti-HCV, anti-HIV and anti- Treponema pallidum testing . Since this control serum is prepared from human plasma, we paid special attention to viral safety . We incorporated three viral inactivation methods into the manufacturing process that maintain the necessary characteristics of a stable control serum .

Chemosphere, 2001 Aug, 44(4), 697 - 700
Oxidation of triphenylarsine to triphenylarsineoxide by Trichoderma harzianum and other fungi; Hofmann K et al.; Arsenic resistant strains of bacteria and fungi were isolated from soil contaminated by chemical warfare agents . Until now, no metabolic products of microbial attack against the phenyl residues of the model substrate triphenylarsine (TP) were found if it was incubated together with these strains in liquid culture assays . However, one of the isolated fungi, Trichoderma harzianum As 11, was found to oxidize TP to triphenylarsineoxide (TPO) . The yeast Trichosporon mucoides SBUG 801 and the white-rot fungus Phanerochaete chrysosporium were also able to oxidize the As(III) in TP . In addition, P . chrysosporium transformed phenylarsineoxide (PAO) to phenylarsonic acid (PAA) under O2-atmosphere . By means of a respirometer system, the oxidation of TP by T . harzianum As 11 was confirmed by a significantly higher consumption of oxygen in the presence of these compounds . HPLC analysis of the oxidation products TPO and PAA in the medium of the assays provided evidence for the transfer reaction of As(III) to As(V) in organic bonds . The oxidation products TPO and PAA are more hydrophilic than TP and PAO . Therefore, it was concluded that particular fungi contribute to the mobilization of arsenic in soil contaminated by chemical warfare agents.

Chemosphere, 2001 Aug, 44(4), 621 - 5
Effect of photosensitizer riboflavin on the fate of 2,4,6-trinitrotoluene in a freshwater environment; Cui H et al.; The effect of riboflavin (1 microM) on the fate of TNT (20 mg/l) in a natural water environment was studied . The relative contribution of photolysis, microbial assemblages and freshwater matrix to TNT degradation was examined . The rates, extent and products of TNT and riboflavin transformation were compared under different experimental conditions . It was found that riboflavin significantly enhanced the degradation of TNT in natural water environment . Thus it is a potentially useful photosensitizing agent for the treatment of TNT-contaminated surface water . Furthermore, in the presence of riboflavin, two new intermediates with max . absorption wavelength of 230 nm were found, demonstrating that transformation of TNT in the presence of riboflavin undergoes different pathways.

J Vet Diagn Invest, 2001 May, 13(3), 219 - 29
Differential detection of Bartonella species and strains in cat scratch disease diagnostics by polymerase chain reaction amplification of 16S ribosomal RNA gene; Tapp RA et al.; Cat scratch disease (CSD) has been difficult to diagnose in animals because of the protracted clinical course of infection and the quiescent phases when the microbial culprit lies dormant . The causative agent in CSD appears to be multiple species and strains of Bartonella . Using polymerase chain reaction (PCR) techniques for amplification of highly variable regions of the 16S ribosomal RNA (rRNA) gene sequence, a very sensitive species- and strain-specific assay for CSD-causing Bartonella species was developed . PCR primers were designed to specifically amplify the 16S rRNA gene of Bartonella species but not of other microbial pathogens . This initial PCR was multiplexed with a universal primer set, based on conserved sequence regions in the 16S rRNA gene, that provides a 162-bp fragment in all species tested . Subsequently, 3 distinct nested PCR primer sets enabled the individual amplification and specific detection of Bartonella henselae type 1, B . henselae type II, and B . clarridgeae . Thus, this 2-step PCR procedure enabled the sensitive detection and identification of these species and the B . henselae genotype by exploiting minor sequences differences . Verification of these results were demonstrated with both sequencing and ligase chain reaction techniques . The diagnostic usefulness of this CSD test has been demonstrated by the analysis of specimens from control and infected cats . The diagnosis was confirmed and the specific B . henselae strain was correctly identified in peripheral blood specimens obtained from control and strain-specific CSD-infected cats . Such an accurate and sensitive diagnostic tool for the detection and identification of CSD causative agents should be a useful for the medical, veterinary, and scientific communities.

Bioresour Technol, 2001 Sep, 79(2), 147 - 54
Influence of one or two successive annual applications of organic fertilisers on the enzyme activity of a soil under barley cultivation; Marcote I et al.; The effect of cow manure and two rates of addition of municipal solid waste (MSW) compost on the enzymatic activity of a soil supporting barley cultivation was studied and compared with mineral fertilisation (MF) . The experiment was carried out in unirrigated land in field conditions for two years . One set of plots was fertilised only once, at the start of the experiment, while another set of plots was fertilised annually (before each sowing) . In general, the organic amendments stimulated soil enzyme activity but mineral fertilisation did not . The annual addition of large quantities of MSW compost, in general, led to lower levels of enzyme activity than similar rates of amendment in the plots receiving a single addition, probably because of the toxic effect which the heavy metals incorporated with the MSW compost had on microbial development . In the second year, plot receiving a single application of organic amendment showed higher protease hydrolysing casein, beta-glucosidase and dehydrogenase activities than control or soil with mineral fertilisation . This implied that the addition of organic waste, and particularly MSW compost, had a catalysing effect in the soil which lasted for the following years . Barley yields obtained with organic amendments were, in general, similar to, or even higher, than those obtained with mineral fertilisation . The annual addition of high doses of compost had an inhibitory effect on enzyme activity and barley yield (compared with the results obtained with the low addition of compost) due to the negative effect of the heavy metals incorporated with the compost.

Environ Sci Technol, 2001 Jul 15, 35(14), 2961 - 6
Evidence for simultaneous abiotic-biotic oxidations in a microbial-Fenton's system; Howsawkeng J et al.; The conditions that support the simultaneous activity of hydroxyl radicals (OH.) and heterotrophic aerobic bacterial metabolism were investigated using two probe compounds: (1) tetrachloroethene (PCE) for the detection of OH . generated by an iron-nitrilotriacetic acid (Fe-NTA) catalyzed Fenton-like reaction and (2) oxalate (OA) for the detection of heterotrophic metabolism of Xanthobacter flavus . In the absence of the bacterium in the quasi-steady-state Fenton's system, only PCE oxidation was observed; conversely, only OA assimilation was found in non-Fenton's systems containing X . flavus . In combined Fenton's-microbial systems, loss of both probes was observed . PCE oxidation increased and heterotrophic assimilation of OA declined as a function of an increase in the quasi-steady-state H2O2 concentration . Central composite rotatable experimental designs were used to determine the conditions that provide maximum simultaneous abiotic-biotic oxidations, which were achieved with a biomass level of 10(9) CFU/mL, 4.5 mM H2O2, and 2.5 mM Fe-NTA . These results demonstrate that heterotrophic bacterial metabolism can occur in the presence of hydroxyl radicals . Such simultaneous abiotic-biotic oxidations may exist when H2O2 is injected into the subsurface as a microbial oxygen source or as a source of chemical oxidants . In addition, hybrid abiotic-biotic systems could be used for the treatment of waters containing biorefractory organic contaminants present in recycle water, cooling water, or industrial waste streams.

J Biol Chem, 2001 Oct 5, 276(40), 37692 - 9 Epub 2001 Jul 26.
Toll-like receptor 2 (TLR2) and TLR4 differentially activate human dendritic cells; Re F et al.; Toll-like receptors (TLRs) mediate cell activation by various microbial products . Here, we demonstrate that activation of dendritic cells by TLR2 or TLR4 agonists, although it led to comparable activation of NF-kappa B and mitogen-activated protein kinase (MAPK) family members, resulted in striking differences in cytokine and chemokine gene transcription, suggesting that TLR2 and TLR4 signaling is not equivalent . A TLR4 agonist specifically promoted the production of the Th1-inducing cytokine interleukin (IL) 12 p70 and the chemokine interferon-gamma inducible protein (IP)-10, which is also associated to Th1 responses . In contrast, TLR2 stimulation failed to induce IL-12 p70 and interferon-gamma inducible protein (IP)-10 but resulted in the release of the IL-12 inhibitory p40 homodimer, producing conditions that are predicted to favor Th2 development . TLR2 stimulation also resulted in preferential induction of IL-8 and p19/IL-23 . Involvement of phosphatidylinositol 3-kinase and p38 MAPK in the TLR-mediated induction of several cytokine and chemokine messages was demonstrated using specific inhibitors . Thus, TLRs can translate the information regarding the nature of pathogens into differences in the cytokines and chemokines produced by dendritic cells and therefore may contribute to the polarization of the acquired immune response.

Q J Nucl Med, 2001 Jun, 45(2), 167 - 73
New concepts in infection/inflammation imaging; Rennen HJ et al.; Although autologous leukocytes, labelled with 111In or 99mTc, is still considered the "gold standard" nuclear medicine technique to image infection and inflammation, there is a great need for a less cumbersome and less hazardous approach . Over the last few decades the range of radiopharmaceuticals to investigate infectious and non-microbial inflammatory disorders is vastly expanding . Radiolabelled monoclonal antibodies and antibody-fragments, radiolabelled chemotactic peptides and cytokines, and radiolabelled antibiotics are promising new approaches in the field of nuclear medicine . Recently, positron emission tomography (PET) with 18FJDG has been introduced and has been shown to delineate infectious and inflammatory foci with high sensitivity . Here, a survey is presented of the different approaches in use or under investigation.

J Appl Microbiol, 2001 Aug, 91(2), 351 - 63
Advances in disinfection testing and modelling; Lambert RJ; AIMS: To develop a set of kinetic equations which more ably describe the disinfection process . METHODS AND RESULTS: A group of functions, the fat equations, based on the model used for the quantification of microbial inhibition, was produced . These functions introduce a limit to the numbers of micro-organisms capable of being disinfected . These new expressions were shown to be more general forms of currently-used (e.g . log-linear) disinfection models, and accommodate the lags and/or tails of non-linear log-survivor--time plots . An advance in the experimental procedures used to obtain disinfection data, using an optical density technique, was developed concomitantly . CONCLUSION: The methods of analyses (experimental and modelling) allow the researcher to examine, more ably, five-minute disinfection (or specific time disinfection tests) as well as the more important disinfection rate analyses . SIGNIFICANCE AND IMPACT OF THE STUDY: The fat equations are an improvement over commonly-used rate models of disinfection, which are shown to be special cases of these equations . This raises the question as to whether our current understanding of the kinetic basis of disinfection requires revision.

J Nat Prod, 2001 Jul, 64(7), 874 - 82
The complestatins as HIV-1 integrase inhibitors . Efficient isolation, structure elucidation, and inhibitory activities of isocomplestatin, chloropeptin I, new complestatins, A and B, and acid-hydrolysis products of chloropeptin I; Singh SB et al.; From the screening of a microbial extract library, isocomplestatin (1), a new axial-chiral isomer of complestatin (2) which is a known rigid bicyclic hexapeptide, was identified as a potent natural product inhibitor of HIV-1 integrase, a unique enzyme responsible for viral replication . Isocomplestatin showed inhibitory activities (IC(50)) in coupled 3'-end processing/strand transfer (200 nM), strand transfer (4 microM), and HIV-1 replication (200 nM) in virus-infected cells . Attempted large-scale isolation of 1 by the literature method, used for the isolation of complestatin, led to lower yield and limited availability . We have developed several new, two-step, high-yielding absorption/elution methods of isolation based on reverse-phase chromatography at pH 8 that are applicable to scales from one gram to potential industrial quantities . We have also discovered and determined the structure of two new congeners of 1, namely, complestatins A (4) and B (5), with almost equal HIV-1 integrase activity . They differ from 1 at C2' and C3' of the tryptophan moiety (residue F) . Selective acid hydrolysis of chloropeptin I (3), itself a known acid-catalyzed rearranged isomer of 1 and 2 (8'- vs 7'-substitution in tryptophan residue F, respectively), an isomer of complestatin, and isocomplestatin resulted in a number of fragments (6-10) with retention of most of the HIV-1 integrase activity . The structure-activity relationship as revealed by these compounds could possibly lead to the design of better inhibitors or understanding of the HIV-1 integrase target.

Bioinformatics, 2001, 17 Suppl 1, S39 - 48
Probe selection algorithms with applications in the analysis of microbial communities; Borneman J et al.; We propose two efficient heuristics for minimizing the number of oligonucleotide probes needed for analyzing populations of ribosomal RNA gene (rDNA) clones by hybridization experiments on DNA microarrays . Such analyses have applications in the study of microbial communities . Unlike in the classical SBH (sequencing by hybridization) procedure, where multiple probes are on a DNA chip, in our applications we perform a series of experiments, each one consisting of applying a single probe to a DNA microarray containing a large sample of rDNA sequences from the studied population . The overall cost of the analysis is thus roughly proportional to the number of experiments, underscoring the need for minimizing the number of probes . Our algorithms are based on two well-known optimization techniques, i.e . simulated annealing and Lagrangian relaxation, and our preliminary tests demonstrate that both algorithms are able to find satisfactory probe sets for real rDNA data.

Environ Microbiol, 2001 Jun, 3(6), 371 - 9
Development of specific oligonucleotide probes for the identification and in situ detection of hydrocarbon-degrading Alcanivorax strains; Syutsubo K et al.; The genus Alcanivorax comprises diverse hydrocarbon-degrading marine bacteria . Novel 16S rRNA-targeted oligonucleotide DNA probes (ALV735 and ALV735-b) were developed to quantify two subgroups of the Alcanivorax/Fundibacter group by fluorescence in situ hybridization (FISH), and the conditions for the single-mismatch discrimination of the probes were optimized . The specificity of the probes was improved further using a singly mismatched oligonucleotide as a competitor . The growth of Alcanivorax cells in crude oil-contaminated sea water under the biostimulation condition was investigated by FISH with the probe ALV735, which targeted the main cluster of the Alcanivorax/Fundibacter group . The size of the Alcanivorax population increased with increasing incubation time and accounted for 91% of the 4',6-diamidino-2-phenylindole (DAPI) count after incubation for 2 weeks . The probes developed in this study are useful for detecting Alcanivorax populations in petroleum hydrocarbon-degrading microbial consortia.

Water Res, 2001 Aug, 35(12), 2833 - 40
Evaluation of new methods for the monitoring of alkalinity, dissolved hydrogen and the microbial community in anaerobic digestion; Bjornsson L et al.; New methods for spectrophotometric alkalinity measurement, dissolved hydrogen monitoring and for obtaining a fingerprint of the microbial community were evaluated as tools for process monitoring in anaerobic digestion . The anaerobic digestion process was operated at organic loading rates of 1.5, 3.0 and 4.5 g volatile solids l(-1)d(-1) and subjected to pulse loads of carbohydrate, lipid, protein and a mixed sludge substrate . The spectrophotometric alkalinity monitoring method showed good agreement with traditional titrimetric alkalinity monitoring and has the advantage of being easy to modify to on-line monitoring applications . The on-line monitoring of dissolved hydrogen gave valuable information about approaching process overload and can be a good complement to the conventional monitoring of volatile fatty acids . Changing process conditions were also reflected in the microbial fingerprint that could be achieved by partitioning in two-phase systems . The investigated methods showed potential for application in increasing our understanding of the anaerobic digestion process as well as for being applicable for monitoring in the complex environment of full-scale anaerobic digestion processes.

Water Res, 2001 Aug, 35(12), 2811 - 8
Influence of sediment and pore-water composition on nitrite accumulation in a nitrate-perfused freshwater sediment; Stief P; Anaerobic nitrate consumption was accompanied by the accumulation of nitrite in the range of 3-52 micromoll(-1) in laboratory sediment cores continuously perfused with nitrate from below . Highest interstitial nitrite concentrations were observed in organically poor sediment cores with a low extractable protein content . Supplemented with an additional source of fixed nitrogen (ammonium), the nitrate-perfused sediments exhibited considerably lower nitrite concentrations than the respective control treatments . The simultaneous addition of ammonium and chloramphenicol, however, resulted in high nitrite concentrations . This suggests that in the absence of chloramphenicol an ammonium-fuelled bacterial protein de novo synthesis prevented the accumulation of nitrite in the course of anaerobic nitrate consumption . Additional DOC (glucose, methanol) generally increased the anaerobic nitrate consumption rate and the interstitial nitrite concentrations . The different scales of these increases were probably related to the degradability of the respective DOC compound and to the taxonomic composition of the microbial community evolving under different feeding regimes.

Dtsch Tierarztl Wochenschr, 2000 Sep, 107(9), 355 - 8
{Animal nutrition for veterinarians--recent cases: odor variations in eggs from brown hens and also possibly in "noncritical" feed composition}; Zentek J et al.; Fishy or unpleasant egg taint occurred in a high frequency (10%) in a herd of brown layers . The hens were fed a commercial standard diet, that did not contain the known critical ingredients as fish meal or rape seed and had an average choline concentration . Sensory tests of the drinking water did not reveal any abnormalities . In a subsequent feeding trial an oral antibiotic treatment with neomycin alone had no positive effects while neomycin and tetracycline reduced egg taint significantly until it became almost normal . Microbial activities in the GI tract were therefore obviously responsible for the egg taint.

Int Immunol, 2001 Aug, 13(8), 1053 - 61
IL-1 beta induces dendritic cells to produce IL-12; Wesa AK et al.; The cytokine IL-12, a product of dendritic cells (DC), plays a major role in cellular immunity, notably by inducing lymphocytes to produce IFN-gamma . Microbial products, T cell signals and cytokines induce the production of IL-12 . Here, IL-1 beta is identified as a new IL-12-inducing agent, acting conjointly with CD40 ligand (CD40L) on human monocyte-derived DC in vitro . The effects of IL-1 beta were dose dependent, specifically blocked by neutralizing antibodies, and were observed both in immature and mature DC . Immature DC secreted more IL-12 than mature DC, but the effects of IL-1 beta were not due to a block of DC maturation as determined by analysis of DC surface markers . The mechanisms of action of IL-1 beta could be contrasted to that of other inducers of IL-12 such as IFN-gamma and lipopolysaccharide (LPS) . Either IL-1 beta or IFN-gamma co-induced IL-12 with CD40L but conjointly, IL-1 beta, CD40L and IFN-gamma synergized, inducing very high levels of IL-12 . The effects of IL-1 beta differed from those of LPS in that IL-1 beta, unlike LPS, could not induce IL-12 solely after IFN-gamma priming; and when combined with CD40L, IL-1 beta, unlike LPS, induced little IL-10 . The mechanism of action of IL-1 beta involves IL-12 alpha mRNA up-regulation, and we show that the combination of CD40L and IL-1 beta induces high levels of IL-12 alpha and IL-12 beta mRNA in DC . Altogether, these results delineate a new mechanism linking adaptive and innate immune responses for the regulation of IL-12 production in DC and for the role of IL-1 beta in the development of cellular immunity.

Curr Gastroenterol Rep, 2001 Aug, 3(4), 343 - 50
Probiotics and functional foods in gastrointestinal disorders; Floch MH et al.; Probiotics are live microbial food supplements that benefit the host animal by improving intestinal microbial balance . When they are fed in yogurts, they can fall into the category of functional foods . Functional foods include these probiotics, prebiotics, and, to a certain extent, dietary fiber . Prebiotics are nondigestible food ingredients or supplements that alter the intestinal flora and stimulate the growth of healthy bacteria . Dietary fibers are part of plant foods that are nonstarch polysaccharides and are poorly digested or not digested by human enzymes . The physiologic process in which probiotics and functional foods affect the intestinal flora is through the balance of the intestinal microecology . This review looks at the four major components of intestinal microecology and describes the probiotics in use today and their clinical relevance . Although probiotics hold great promise and appear to be useful in some settings, more clinical study is needed to firmly establish the relevance of probiotic therapy.

Curr Drug Targets, 2001 Jun, 2(2), 135 - 66
Update on antifolate drugs targets; Costi MP et al.; Antifolate drugs are molecules directed to interfere with the folate metabolic pathway at some level . They can be recognized among the first rationally designed compounds applying the principle of structural analogy with the substrate developing the antimetabolite strategy . This strategy has taken advantage of the basic different features of the microbial and human folate metabolism and therefore allows targeting the pathway at different steps generating a specificity tools for Medicinal Chemists . Two main problems are giving renewed importance to such targets and therefore improving the efforts to discover new targets in the folate metabolism area . The first one is the increasing resistance to the present drugs due to different mechanisms such as the enzyme modification and the increased production of enzymes with not well recognized importance . The second one is the development of techniques directed to highlight the interference at genetic level of molecular probes as antifolate drug to develop new enzymes previously unknown . This approach is defined as genetic approach to drug discovery, from gene to drugs . The present article describes the importance in drug design and discovery of some antifolate targets among the best known at the present status of research such as thymidylate synthase (TS), dhydrofolate reductases, (DHFR) serine hydroxymethyltransferase (SHMT), folyilpolyglutamyl synthetase (FPGS), gamma-glutamyl hydrolase (gamma-GH), glycinamide-ribonucleotide transformylase (GARTfase), amino-imidazole-carboxamide-ribonucleotide transformylase (AICARTfase) and Folate transporters . Discovery, known functions, structure/function studies and inhibition will be described.

MMW Fortschr Med, 2001 Jun 14, 143(24), 30 - 3
{Diagnosis of eczema . Can you recognize what your patient's symptom?}; Iliev D et al.; The term eczema is applied to specific non-infectious inflammatory reactions of the skin, and covers a number of etiologically highly heterogeneous conditions which, however, demonstrate common features in terms of clinical presentation and pathogenesis . Eczematous disorders account for approximately 20% of the dermatological disturbances . They include allergic, contact and irritant contact dermatitis, atopic dermatitis, seborrheic dermatitis, nummular-microbial and dyshidrotic eczema, and stasis eczema . They have a high individual and socio-economic impact, and are dependent on individual predisposition.

Protein Sci, 2001 Aug, 10(8), 1658 - 68
Involvement of the amino-terminal beta-hairpin of the Aspergillus ribotoxins on the interaction with membranes and nonspecific ribonuclease activity; Garcia-Ortega L et al.; Ribotoxins are a family of potent cytotoxic proteins from Aspergillus whose members display a high sequence identity (85% for about 150 amino acid residues) . The three-dimensional structures of two of these proteins, alpha-sarcin and restrictocin, are known . They interact with phospholipid bilayers, according to their ability to enter cells, and cleave a specific phosphodiester bond in the large subunit of ribosome thus inhibiting protein biosynthesis . Two nonconservative sequence changes between these proteins are located at the amino-terminal beta-hairpin of alpha-sarcin, a characteristic structure that is absent in other nontoxic structurally related microbial RNases . These two residues of alpha-sarcin, Lys 11 and Thr 20, have been substituted with the equivalent amino acids in restrictocin . The single mutants (K11L and T20D) and the corresponding K11L/T20D double mutant have been produced in Escherichia coli and purified to homogeneity . The spectroscopic characterization of the purified proteins reveals that the overall native structure is preserved . The ribonuclease and lipid-perturbing activities of the three mutants and restrictocin have been evaluated and compared with those of alpha-sarcin . These proteins exhibit the same ability to specifically inactivate ribosomes, although they show different activity against nonspecific substrate analogs such as poly(A) . The mutant variant K11L and restrictocin display a lower phospholipid-interacting ability correlated with a decreased cytotoxicity . The results obtained are interpreted in terms of the involvement of the amino-terminal beta-hairpin in the interaction with both membranes and polyadenylic acid.

J Immunol, 2001 Aug 1, 167(3), 1542 - 9
Mycobacterium tuberculosis 19-kDa lipoprotein promotes neutrophil activation; Neufert C et al.; Certain microbial substances, e.g., LPS, can activate neutrophils or prime them to enhance their response to other activating agents, e.g., fMLP . We investigated the role of the Mycobacterium tuberculosis (MTB) 19-kDa lipoprotein in activation of human neutrophils . MTB 19-kDa lipoprotein initiated phenotypic changes characteristic of neutrophil activation, including down-regulation of CD62 ligand (L-selectin) and up-regulation of CD35 (CR1) and CD11b/CD18 (CR3, Mac-1) . In addition, exposure of neutrophils to MTB 19-kDa lipoprotein enhanced the subsequent oxidative burst in response to fMLP as assessed by oxidation of dihydrorhodamine 123 (determined by flow cytometry) . LPS also produced these effects with similar kinetics, but an oligodeoxynucleotide containing a CpG motif failed to induce any priming or activation response . Although the effects of LPS required the presence of serum, neutrophil activation by MTB 19-kDa lipoprotein occurred independently of serum factors, suggesting the involvement of different receptors and signaling mechanisms for LPS and MTB 19-kDa lipoprotein . Thus, MTB 19-kDa lipoprotein serves as a pathogen-associated molecular pattern that promotes neutrophil priming and activation.

J Immunol, 2001 Aug 1, 167(3), 1423 - 30
IL-12 induction by a TH1-inducing adjuvant in vivo: dendritic cell subsets and regulation by IL-10; Huang LY et al.; IL-12 induction is critical for immune responses against many viruses and intracellular bacterial pathogens . Recent studies suggest that IL-12-secreting dendritic cells (DC) are potent Th1-inducing APC . However, controversy exists concerning the function of DC subsets . Murine studies have suggested that CD8(+) DC preferentially induce Th1 responses, whereas CD8(-) DC induce Th2 development; in this model, different DC subsets prime different responses . Alternatively, the propensity of DC subsets to prime a Th1 response could depend upon the type of initial stimulus . We used a prototypic Th1-inducing adjuvant, heat-killed Brucella abortus (HKBA) to assess stimulation of DC subsets, relationship between Ag burden and IL-12 production, and down-regulation of DC subset IL-12 production by IL-10 . In this study, we show that DC were sole producers of IL-12, although most HKBA uptake was by splenic macrophages and granulocytes . More CD8(-) than CD8(+) DC produced IL-12 after HKBA challenge, whereas only CD8(+) DC produced IL-12 after injection of another Th1-promoting microbial substance, soluble Toxoplasma gondii Ags . Studies in IL-10-deficient mice revealed that IL-10 down-regulates frequency and duration of IL-12 production by both DC subsets . In the absence of IL-10, IL-12 expression is enabled in CD11c(low) cells, but not in macrophages or granulocytes . These findings support the concept of DC as the major IL-12 producers in spleens, but challenge the notion that CD8(+) and CD8(-) DC are destined to selectively induce Th1 or Th2 responses, respectively . Thus, the nature of the stimulating substance is important in determining which DC subsets are activated to produce IL-12.

J Bacteriol, 2001 Aug, 183(16), 4866 - 75
Oxidation of phenolate siderophores by the multicopper oxidase encoded by the Escherichia coli yacK gene; Kim C et al.; A gene (yacK) encoding a putative multicopper oxidase (MCO) was cloned from Escherichia coli, and the expressed enzyme was demonstrated to exhibit phenoloxidase and ferroxidase activities . The purified protein contained six copper atoms per polypeptide chain and displayed optical and electron paramagnetic resonance (EPR) spectra consistent with the presence of type 1, type 2, and type 3 copper centers . The strong optical A(610) (E(610) = 10,890 M(-1) cm(-1)) and copper stoichiometry were taken as evidence that, similar to ceruloplasmin, the enzyme likely contains multiple type 1 copper centers . The addition of copper led to immediate and reversible changes in the optical and EPR spectra of the protein, as well as decreased thermal stability of the enzyme . Copper addition also stimulated both the phenoloxidase and ferroxidase activities of the enzyme, but the other metals tested had no effect . In the presence of added copper, the enzyme displayed significant activity against two of the phenolate siderophores utilized by E . coli for iron uptake, 2,3-dihydroxybenzoate and enterobactin, as well as 3-hydroxyanthranilate, an iron siderophore utilized by Saccharomyces cerevisiae . Oxidation of enterobactin produced a colored precipitate suggestive of the polymerization reactions that characterize microbial melanization processes . As oxidation should render the phenolate siderophores incapable of binding iron, yacK MCO activity could influence levels of free iron in the periplasm in response to copper concentration . This mechanism may explain, in part, how yacK MCO moderates the sensitivity of E . coli to copper.

J Anim Sci, 2001 Jul, 79(7), 1892 - 904
Effects of tallow on the energy metabolism of wethers fed barley finishing diets; Nelson ML et al.; A balance trial was conducted to titrate the effects of tallow on the energy metabolism of wethers fed barley finishing diets . Six dietary levels of tallow (0, 2, 4, 6, 8, or 10%) in a barley finishing diet were fed to six crossbred wethers (35+/-1.1 kg) in a randomized complete block design . Diets were 73% barley, 10% tallow and(or) bentonite, 10% alfalfa pellets, and 7% supplement . There was no effect of tallow level on OM intake (1,103.1+/-51 g/d), OM digestibility (84+/-0.9%), GE digestibility (83+/-1.1%), or cell solubles digestibility (84.2+/-1.2%) . The level of tallow quadratically decreased ADF digestibility (P < 0.05), methane emissions, and methane energy as a percentage of GE P < 0.01) . There were linear increases in dietary GE (megacalories per kilogram of OM {P < 0.01}), dietary DE (megacalories per kilogram of OM {P < 0.05}), and dietary ME (megacalories per kilogram of OM {P < 0.01}), as dietary tallow increased . Numbers of ruminal protozoa (Entodinium spp . and Polyplastron sp.) decreased linearly (P < 0.05) with increased level of tallow . The energy value of tallow (calculated by difference) was low . The total-tract fatty acid digestibility of tallow was calculated by linear regression, without intercept, after accounting for the fatty acids digested from the base diet (0% tallow fed to a wether in a period) . Fatty acids of the same carbon length were pooled for the regression analysis . All linear regressions were significant (P < 0.10) indicating no effect of tallow level on fatty acid digestibility . Lauric acid had low digestibility . The high digestibility of all C16 (89%) and C18 (104%) fatty acids suggests an effect of tallow on endogenous and microbial fatty acid excretion . Fatty acid digestibility was probably a minor contributor to the low energy content of tallow, calculated by difference, in these diets.

Curr Drug Metab, 2001 Mar, 2(1), 67 - 85
Bestatin as an experimental tool in mammals; Scornik OA et al.; Bestatin, an antibiotic of microbial origin, is a potent inhibitor of some, but not all aminopeptidases . It can be administered, with low toxicity, to cultured cells, intact animals and humans . It has become a useful tool in elucidating the physiological role of some mammalian exopeptidases in the regulation of the immune system, in the growth of tumors and their invasion of surrounding tissues, and in the degradation of cellular proteins . Bestatin-sensitive enzymes play important roles in the digestion and absorption of peptides in the brush border of the intestine and the kidney, in the reproductive system, and in the metabolism of opioid peptides and leukotrienes . Aminopeptidase N emerges as the major target for the effects of bestatin on the immune system and some of its effects on tumor growth and the endometrium . It is also the major bestatin-sensitive enzyme involved in the degradation of oligopeptides on the surface of intestine and kidney brush borders, and the inactivation of enkephalins in the brain . Bestatin-sensitive cytosolic exopeptidases are important in the degradation to amino acids of di- and tripeptides generated in most cells by cellular protein degradation, as well as those absorbed through the brush border of intestine and kidney . Inhibition of one of these exopeptidases, cytosol alanine aminopeptidase, results in apoptosis . Bestatin-sensitive cystinyl aminopeptidase is abundant in placenta . Two bestatin-sensitive enzymes, aminopeptidase B and nardilysin, are particularly abundant in late spermatids . Finally bestatin-sensitive LTA4 hydrolase generates the potent chemotactic agent, LTB4.

Eur J Immunol, 2001 May, 31(5), 1475 - 84
Toxoplasma gondii down-regulates MHC class II gene expression and antigen presentation by murine macrophages via interference with nuclear translocation of STAT1alpha; Luder CG et al.; The obligate intracellular protozoan parasite Toxoplasma gondii is able to establish persistent infections within human and animal hosts . We have shown recently that T . gondii down-regulates IFN-gamma-induced MHC class II expression in murine bone marrow-derived macrophages (BMM4) . As shown in this study, the capacity of IFN-gamma-activated murine BMMphi to present ovalbumin to CD4+ T cell hybridomas was dose-dependently inhibited by T . gondii . IFN-gamma-induced up-regulation of H2-Aa, H2-Ab, H2-Eb, H2-Ma, H2-Mb, H2-Oa and invariant chain transcripts was prominently down-regulated by T . gondii . Furthermore, mRNA levels of class II transactivator and interferon-regulatory factor-1 were significantly diminished . Electromobility shift assays demonstrated a decrease in the binding activity of nuclear extracts to the IFN-gamma-activated site after infection with T . gondii, indicating parasitic interference with IFN-gamma-induced signaling . However, neither the expression of the IFN-gammaR nor the IFN-gamma-induced tyrosine phosphorylation of IFN-gammaR alpha chain and signal transducer and activator of transcription (STAT) 1alpha was diminished by T . gondii . IFN-gamma-induced nuclear translocation of STAT1alpha was nevertheless inhibited after infection as demonstrated by immunofluorescence microscopy and subcellular fractionation analyses . In conclusion, this novel mechanism of microbial interference with MHC class II gene expression may contribute to intracellular survival and establishment of persistent infection with T . gondii.

Pest Manag Sci, 2001 Jul, 57(7), 640 - 4
The effect of the herbicide diuron on soil microbial activity; Prado AG et al.; The inhibitory effect of the herbicide diuron {3-(3,4-dichlorophenyl)-1,1-dimethylurea} on microbial activity in red Latosol soil was followed using microcalorimetry . The activity of the micro-organisms in 1.50 g of soil sample was stimulated by addition of 6.0 mg of glucose and 6.0 mg of ammonium sulfate under 35% controlled humidity at 298.15 (+/- 0.02) K . This activity was determined by power-time curves that were recorded for increasing amounts of diuron, varying from zero to 333.33 micrograms g-1 soil . An increase in the amount of diuron in soil caused a decrease of the original thermal effect, to reach a null value above 333.33 micrograms g-1 of herbicide . The power-time curve showed that the lag-phase period and peak time increased with added herbicide . The decrease of the thermal effect evolved by micro-organisms and the increase of the lag-phase period are associated with the death of microbial populations caused by diuron, which strongly affects soil microbial communities.

Water Sci Technol, 2001, 43(12), 229 - 32
Degradation of cyanobacterial hepatotoxins in batch experiments; Miller MJ et al.; Bank filtration offers a cost effective and low maintenance technique for the removal of cyanobacterial hepatotoxins from drinking water . For bank filtration to be effective, the toxins must be degraded . The broad aim of this research was to determine whether the hepatotoxins, nodularin and microcystin-LR, could be completely removed from the soil/water matrix of three soils by microbial degradation . The results indicated that complete toxin removal was possible within 10-16 d in 2/3 soils that were incubated in the dark at 20 degrees C . The soils with the highest organic carbon content (2.9%) and the highest clay content (16.1%) were the most effective at removing the toxins in batch experiments . However, the sandy soil (98.5% sand) was incapable of degrading either toxin . The half-lives of toxin losses due to adsorption, desorption and degradation were calculated and for all soils . The degradation process had the highest half-life for both toxins . This suggested that degradation was likely to be the rate-limiting step of complete toxin removal . It was concluded that when a bank filtration site was being chosen, the degradation potential and the textural properties of the riverbank soil would be important when considering complete removal of cyanobacterial hepatotoxins.

Water Sci Technol, 2001, 43(12), 19 - 22
Correlations between microbial parameters from water samples: expectations and reality; Tillett HE et al.; Data which are collected in order to estimate the correlation between parameters must be analysed with caution . Classical statistics of correlation are often inappropriate . The "r" statistic is very easily distorted by non-Normal data . Non-parametric statistics can be helpful . The interpretation and usefulness of the estimates of correlation will depend on the study plan . If water samples come from disparate sources (e.g . upstream or downstream from sewage outlets) then parameters A and B may occur in their highest and lowest numbers according to how close the samples were to contamination sources thus correlating closely . However, if all samples come from sources with similar pollution levels then plots of A and B will show considerable scatter and apparently little correlation . So what is the relationship between A and B? An example of "perfect" correlation, as demonstrated by replicate counts of a single parameter from split samples, gave an r value of only 0.63 (p = 0.62) due to random variation in numbers of organisms between the two halves of the sample . Thus large amounts of data are needed for studying true correlation because relationships between parameters are embedded in the natural variation . This also illustrated that Standards for a single parameter can be "passed" or "failed" by two halves of the same sample . Study design is clearly of fundamental importance . Consideration must be given to the appropriate way of asking questions about correlation between different parameters.

J Hosp Infect, 2001 Aug, 48(4), 304 - 7
Comparison of microbial contamination of enteral feeding solution between repeated use of administration sets after washing with water and after washing followed by disinfection; Oie S et al.; We compared microbial contamination of in-use enteral feeding solution from repeatedly used administration sets (a delivery bag and an infusion tube) after washing with water or washing followed by disinfection . In eight hospitals where administration sets were re-used after washing with water, residual solution was collected from both the delivery bag and the distal end of the infusion tube immediately after use and the microbial contamination level and microbial species found examined . The residual enteral feeding solution (28 samples) in the delivery bag grew 10(2)-10(8) colony forming units (cfu)/mL and 36 samples from the distal end of the infusion tube grew 10(2)-10(9) cfu/mL . Re-processing was changed to washing with water followed by disinfection with 0.1% (100 ppm) sodium hypochlorite, and similar examinations were performed . The residual solutions in the bag (22 samples) and in the distal end of the infusion tube (24 samples) were contaminated with < 10(1)-10(4) cfu/mL each, a significant decrease (P < 0.01, Wilcoxon U-test) compared with washing with water alone .

J Hosp Infect, 2001 Aug, 48(4), 289 - 97
Mechanisms and risk factors for infection of pulmonary artery catheters and introducer sheaths in cancer patients admitted to an intensive care unit; Blot F et al.; Pulmonary artery catheters (PACs) are typically inserted for short periods, and the extra-luminal route is assumed to be the overriding source of contamination and/or infection . Our aim was to assess the incidence of PAC and introducer colonization in cancer patients, and to study the mechanisms and risk factors for infection . Patients with a Swan-Ganz catheter admitted to an intensive care unit were prospectively analyzed over 14 months . As soon they were no longer necessary, PACs and introducer sheaths were removed and cultured . We recorded the mean duration of placement, the number of times PACs were handled and the site of insertion . Seventy-nine catheters were inserted in 68 patients . The median (range) duration was three days (0-10) for PACs, and 3.6 days (0-18) for introducers . PAC and/or percutaneous introducer sheath colonization was diagnosed in seven patients (8.9%), but in only one case were both colonized . Colonization rates were 15.5 per 1000 days for PACs and 14.1 per 1000 days for introducers . Introducers were mainly colonized before the 5th day, while PACs were mainly colonized after the 5th day . No PAC or introducer-related local infection or bacteraemia was diagnosed . Colonization was more frequent on catheters inserted into the internal jugular vein . The colonization rate was 5% for PACs and introducers . Our findings suggest that contamination of introducers and PACs may be dissociated and could result from either extraluminal or endoluminal colonization . As three of four PAC colonizations occurred after 5 days, the duration of catheter placement should be considered important . There was little clinical impact of microbial colonization .

Mar Environ Res, 2000 Jul-Dec, 50(1-5), 141 - 5
Metabolism and organ distribution of nonylphenol in Atlantic salmon (Salmo salar); Arukwe A et al.; Nonylphenol (NP) is a breakdown product of alkylphenol polyethoxylates (APEs), an important class of non-ionic surfactants that are widely used in many detergent formulations and plastic products for industrial and domestic use . A complex microbial degradation pattern, characterized by the formation of several metabolic products that are more toxic than the parent compound, has been established for APEs . We have studied the in vivo metabolism and organ distribution of NP in juvenile salmon . Fish were exposed to a single oral dose of {3H}-4-n-NP (1295 KBq, 25 micrograms) and sampled at 24, 48 and 72 h after exposure . Metabolites were separated by radio-high-performance liquid chromatography and tentatively identified by cochromatography with standards characterized by mass spectrometry . Our results show that 4-n-NP was mainly metabolized in vivo to its corresponding glucuronide conjugate and to a lesser extent to various hydroxylated and oxidated compounds . Biliary excretion at 72 h after dosing amounted to 2.83 +/- 0.75% of the administered radioactivity . Kinetic analysis shows that NP-glucuronide accounted for 83, 95 and 81% of total radioactivity in the HPLC-injected bile sample at 24, 48 and 72 h, respectively, after exposure . The half-life of residues in carcass and muscle was between 24 and 48 h after exposure.

Proc Natl Acad Sci U S A, 2001 Jul 17, 98(15), 8334 - 41
Stationary-phase mutation in the bacterial chromosome: recombination protein and DNA polymerase IV dependence; Bull HJ et al.; Several microbial systems have been shown to yield advantageous mutations in slowly growing or nongrowing cultures . In one assay system, the stationary-phase mutation mechanism differs from growth-dependent mutation, demonstrating that the two are different processes . This system assays reversion of a lac frameshift allele on an F' plasmid in Escherichia coli . The stationary-phase mutation mechanism at lac requires recombination proteins of the RecBCD double-strand-break repair system and the inducible error-prone DNA polymerase IV, and the mutations are mostly -1 deletions in small mononucleotide repeats . This mutation mechanism is proposed to occur by DNA polymerase errors made during replication primed by recombinational double-strand-break repair . It has been suggested that this mechanism is confined to the F plasmid . However, the cells that acquire the adaptive mutations show hypermutation of unrelated chromosomal genes, suggesting that chromosomal sites also might experience recombination protein-dependent stationary-phase mutation . Here we test directly whether the stationary-phase mutations in the bacterial chromosome also occur via a recombination protein- and pol IV-dependent mechanism . We describe an assay for chromosomal mutation in cells carrying the F' lac . We show that the chromosomal mutation is recombination protein- and pol IV-dependent and also is associated with general hypermutation . The data indicate that, at least in these male cells, recombination protein-dependent stationary-phase mutation is a mechanism of general inducible genetic change capable of affecting genes in the bacterial chromosome.

Nature, 2001 Jun 14, 411(6839), 848 - 53
Programmed cell death, mitochondria and the plant hypersensitive response; Lam E et al.; The plant response to attempted infection by microbial pathogens is often accompanied by rapid cell death in and around the initial infection site, a reaction known as the hypersensitive response . This response is associated with restricted pathogen growth and represents a form of programmed cell death (PCD) . Recent pharmacological and molecular studies have provided functional evidence for the conservation of some of the basic regulatory mechanisms underlying the response to pathogens and the activation of PCD in animal and plant systems . In animals, the mitochondrion integrates diverse cellular stress signals and initiates the death execution pathway, and studies indicate a similar involvement for mitochondria in regulating PCD in plants . But many of the cell-death regulators that have been characterized in humans, worms and flies are absent from the Arabidopsis genome, indicating that plants probably use other regulators to control this process.

Nature, 2001 Jun 14, 411(6839), 843 - 7
Natural products and plant disease resistance; Dixon RA; Plants elaborate a vast array of natural products, many of which have evolved to confer selective advantage against microbial attack . Recent advances in molecular technology, aided by the enormous power of large-scale genomics initiatives, are leading to a more complete understanding of the enzymatic machinery that underlies the often complex pathways of plant natural product biosynthesis . Meanwhile, genetic and reverse genetic approaches are providing evidence for the importance of natural products in host defence . Metabolic engineering of natural product pathways is now a feasible strategy for enhancement of plant disease resistance.

Nature, 2001 Jun 14, 411(6839), 786 - 9
Proteorhodopsin phototrophy in the ocean; Beja O et al.; Proteorhodopsin, a retinal-containing integral membrane protein that functions as a light-driven proton pump, was discovered in the genome of an uncultivated marine bacterium; however, the prevalence, expression and genetic variability of this protein in native marine microbial populations remain unknown . Here we report that photoactive proteorhodopsin is present in oceanic surface waters . We also provide evidence of an extensive family of globally distributed proteorhodopsin variants . The protein pigments comprising this rhodopsin family seem to be spectrally tuned to different habitats--absorbing light at different wavelengths in accordance with light available in the environment . Together, our data suggest that proteorhodopsin-based phototrophy is a globally significant oceanic microbial process.

J Gen Virol, 2001 Aug, 82(Pt 8), 1941 - 50
Mutational analysis of the major heparan sulfate-binding domain of herpes simplex virus type 1 glycoprotein C; Mardberg K et al.; Heparan sulfate (HS) has been identified as a receptor molecule for numerous microbial pathogens, including herpes simplex virus type 1 (HSV-1) . To further define the major HS-binding domain of the HSV-1 attachment protein, i.e . glycoprotein C (gC), virus mutants carrying alterations of either two neighbouring basic amino acid residues or a single hydrophobic amino acid residue within the N-terminal domain of the protein (residues 26-227) were constructed . In addition, a mutant lacking the Asn148 glycosylation site was included in the study . Binding of purified mutated gC proteins to isolated HS chains showed that viruses with mutations at residues Arg(129,130), Ile142, Arg(143,145), Arg(145,147), Arg(151,155) and Arg(155,160) had significantly impaired HS binding, in contrast to the other mutations, including Asn148 . Impairment of the HS-binding activity of gC by these mutations had profound consequences for virus attachment and infection of cells in which amounts of HS exposed on the cell surface had been reduced . It is suggested that basic and hydrophobic residues localized at the Cys127-Cys144 loop of HSV-1 gC constitute a major HS-binding domain, with the most active amino acids situated near the C-terminal region of the two cysteines.

Vet Immunol Immunopathol, 2001 Aug 10, 80(3-4), 209 - 23
Opsonization of yeast cells with equine iC3b, C3b, and IgG; Grondahl G et al.; The main opsonins in serum are antibodies and complement factor C3 . The opsonization mechanisms including complement activation and deposition are important in studies of phagocytosis and of mechanisms of microbial immune evasion . The objective of the present study was to monitor the deposition of complement C3 and IgG from equine serum on yeast cells (Saccharomyces cerevisiae) using a flow cytometric immunoassay . Correlations were made between the opsonic coating and phagocytic capacity using equine blood neutrophils . In addition, the bound C3 fragments were characterized by SDS-PAGE and Western blot analyses.Opsonic coating of yeast with equine C3 and IgG occurred rapidly with detectable levels with as little as 0.75% serum . C3 deposition was a result of complement activation and no passive adsorption was observed . When complement was inactivated, the fluorescence indicating IgG deposition increased 3-6-fold, indicating spatial competition between C3 and IgG at binding.Opsonization with 1.5% serum led to suboptimal equine neutrophil phagocytosis of yeast cells which was dependent on complement activation by the classical pathway . With > or =6.25% serum, IgG contributed to opsonization and phagocytosis . With 50% serum and more, C3 was deposited also by the alternative pathway . Phagocytosis rates became optimal with 3% serum, and did not increase further with higher serum concentrations . The main form of C3 on the yeast cells was iC3b and the rest was C3b without any detectable breakdown products (C3c or C3dg) . The equine complement components are similar in size to the human equivalents.It may be concluded that opsonization of yeast particles leading to phagocytosis, occurs at very low serum concentrations (1.5%) and that it is dependent on activation of the classical complement pathway at this low opsonic level . This is an important finding for efficient host defense, e.g . extravascular phagocytosis at infection sites.

Biomaterials, 2001 Aug, 22(16), 2215 - 28
Examination of in vivo influences on bioluminescent microbial assessment of corrosion product toxicity; Shettlemore MG et al.; The composition of ionically dissolved and precipitated corrosion products from both free corrosion of ASTM F75 Co-Cr-Mo and galvanostatic polarization of Co-Cr-Mo and F138 316L stainless steel was determined using differential pulse polarography and inductively coupled plasma atomic emission spectroscopy . A bacterial bioluminescence assay, Microtox, was used to assess the toxicity of the solid and dissolved corrosion products produced by galvanostatic polarization and the individual ions within them . The role of in vivo salinity, temperature, and protein content as modulators of corrosion product toxicity assessment was investigated empirically and mechanistically . Co-Cr-Mo products were found to be more toxic than those of 316L, and the most toxic ions were Cr6+, Ni2+, and Co2+ . Ringer's solution potentiated the toxicity of the more toxic metal ions and reduced the toxicity of the less toxic ions . Using theoretical analysis in conjunction with experimental measurements, the ions in both alloys were found to interact in an antagonistic fashion . The presence of albumin was found to decrease metal toxicity, presumably by chelation.

Pest Manag Sci, 2001 Apr, 57(4), 333 - 40
An appraisal of methods for measurement of pesticide transformation in the groundwater zone; Leistra M et al.; Laboratory and field studies show that pesticides may be transformed in the groundwater zone . Possible reaction mechanisms are chemical hydrolysis, catalytic reduction and aerobic or anaerobic microbial transformation . Transformation in the groundwater zone can be an important element in the advanced evaluation of the potential risk arising from a pesticide in the public drinking water supply . However, rate and pathway of transformation can show large differences, depending on the bio-geochemical conditions in the groundwater zone . Knowledge of the reaction mechanisms and the effect of aquifer conditions would allow vulnerable and low-vulnerable application areas for a pesticide to be delimited . An outline is given of possible approaches to quantifying these transformation processes and using the results in registration procedures, especially in the EU and its member states . Furthermore, areas where there is need for continued research and better understanding are highlighted.

Proteins, 2001 Aug 15, 44(3), 392 - 6
Self-repair of biological fibers catalyzed by the surface of a virus crystal; Kuznetsov YG et al.; Helical fibers, presumably proteinaceous and of microbial origin, have been visualized by atomic force microscopy on the surfaces of crystals of satellite tobacco mosaic virus . If the crystals are growing, then the fibers are incorporated intact into the crystal lattice . If broken on the crystal surface, then within a few minutes, the fibers self-reassemble to reestablish continuity . This, we believe, is the first observation of such a crystal surface-catalyzed repair of a biological structure . The surfaces of virus crystals provide ideal workbenches for the visualization and manipulation of nanoscale objects, particularly extended structures such as these fibers.

Am J Vet Res, 2001 Jul, 62(7), 1104 - 12
Experimental induction of chronic borreliosis in adult dogs exposed to Borrelia burgdorferi-infected ticks and treated with dexamethasone; Chang YF et al.; OBJECTIVE: To develop a method to experimentally induce Borrelia burgdorferi infection in young adult dogs . ANIMALS: 22 healthy Beagles . PROCEDURE: All dogs were verified to be free of borreliosis . Twenty 6-month-old dogs were exposed to Borrelia burgdorferi-infected adult ticks and treated with dexamethasone for 5 consecutive days . Two dogs not exposed to ticks were treated with dexamethasone and served as negative-control dogs . Clinical signs, results of microbial culture and polymerase chain reaction (PCR) testing, immunologic responses, and gross and histologic lesions were evaluated 9 months after tick exposure . RESULTS: Predominant clinical signs were episodic pyrexia and lameness in 12 of 20 dogs . Infection with B burgdorferi was detected in microbial cultures of skin biopsy specimens and various tissues obtained during necropsy in 19 of 20 dogs and in all 20 dogs by use of a PCR assay . All 20 exposed dogs seroconverted and developed chronic nonsuppurative arthritis . Three dogs also developed mild focal meningitis, 1 dog developed mild focal encephalitis, and 18 dogs developed perineuritis or rare neuritis . Control dogs were seronegative, had negative results for microbial culture and PCR testing, and did not develop lesions . CONCLUSIONS AND CLINICAL RELEVANCE: Use of this technique successfully induced borreliosis in young dogs . Dogs with experimentally induced borreliosis may be useful in evaluating vaccines, chemotherapeutic agents, and the pathogenesis of borreliosis-induced arthritis.

Vopr Pitan, 2000, 69(6), 22 - 4
{Possibility of participation of bacterial factor in the correction of histamine metabolism in the body}; Kuiarov AV et al.; Microbial factor belongs a significant role in mechanisms of regulation of contents free histamine in the organism . Magnified amounts this mediator connected with the condition of microbial ecology, can stimulate a number of pathophysiological effects . This dictates need of further studying dug autoflora master in processes of accumulation free histamine in the organism and their correction.

Transfusion, 2001 Jul, 41(7), 873 - 7
WBC-reduced blood transfusions and clinical outcome in children with acute lymphoid leukemia; Rios JA et al.; BACKGROUND: WBC reduction offers a variety of benefits to patients requiring multiple transfusions during induction therapy for childhood acute lymphoid leukemia (ALL), including reductions in febrile transfusion reactions, HLA alloimmunization, and CMV transmission . One potential benefit is a reduction in the deleterious effects of transfusion immunomodulation . In the surgical setting, transfusion immunomodulation has been linked to increases in postoperative infections and decreases in host cellular immunity that are mitigated by WBC reduction of transfused blood . STUDY DESIGN AND METHODS: A retrospective review was conducted of the medical records of 68 consecutive children undergoing induction therapy for newly diagnosed ALL from 1988 through 1995, a period whose midpoint is 1991, the year WBC reduction was introduced in this hospital . RESULTS: WBC reduction of platelet and RBC transfusions was associated with fewer days with fever (mean, 5.7 days {no WBC reduction} and 2.1 days {WBC reduction}; p = 0.012) and days with positive microbial cultures (mean, 1.5 {no WBC reduction} and 0.71 {WBC reduction}; p = 0.0055) . There were more high-risk ALL patients in the group receiving WBC-reduced transfusions . CONCLUSION: Allogeneic WBCs in transfused blood may cause impairment of host defenses against microbial infection during induction therapy for childhood ALL.

Science, 2001 Aug 24, 293(5534), 1499 - 503 Epub 2001 Jul 12.
Crystal structure of sensory rhodopsin II at 2.4 angstroms: insights into color tuning and transducer interaction; Luecke H et al.; We report an atomic-resolution structure for a sensory member of the microbial rhodopsin family, the phototaxis receptor sensory rhodopsin II (NpSRII), which mediates blue-light avoidance by the haloarchaeon Natronobacterium pharaonis . The 2.4 angstrom structure reveals features responsible for the 70- to 80-nanometer blue shift of its absorption maximum relative to those of haloarchaeal transport rhodopsins, as well as structural differences due to its sensory, as opposed to transport, function . Multiple factors appear to account for the spectral tuning difference with respect to bacteriorhodopsin: (i) repositioning of the guanidinium group of arginine 72, a residue that interacts with the counterion to the retinylidene protonated Schiff base; (ii) rearrangement of the protein near the retinal ring; and (iii) changes in tilt and slant of the retinal polyene chain . Inspection of the surface topography reveals an exposed polar residue, tyrosine 199, not present in bacteriorhodopsin, in the middle of the membrane bilayer . We propose that this residue interacts with the adjacent helices of the cognate NpSRII transducer NpHtrII.

FEMS Microbiol Ecol, 2001 Jul, 36(2-3), 139 - 151
PCR-SSCP comparison of 16S rDNA sequence diversity in soil DNA obtained using different isolation and purification methods; Stach JE et al.; This study compared different methods of direct DNA extraction and purification from a silt loam soil and investigated the relationship between DNA quantity and sequence diversity . Five extraction methods and four purification techniques were investigated . Quantities of DNA extracted were between 3.4+/-0.55 and 54.3+/-8.18 &mgr;g g(-1) (dry wt) of soil with OD(260)/OD(230) purity ratios between 0.80 and 1.15 . Analysis of sequence diversity in all extracts was conducted using PCR-single strand conformation polymorphism (SSCP) . Profiles generated using universal 16S rDNA primers (Com1/Com2) were found to be identical when used to amplify 16S rDNA extracted directly from soil . The genus Pseudomonas was targeted in order to reduce profile complexity, which was apparent when using universal 16S rDNA primers, and which hindered direct comparison of sequence diversity . A Pseudomonas culture library and non-cultured Pseudomonas 16S rDNA genes were used to provide a background count of Pseudomonas operational taxonomic units present in the soil . Cloning and sequencing of amplicons generated using a Pseudomonas-specific (Ps-for) and a universal 16S rDNA (Com2) primer, coupled with nested amplification (Com1/Com2 amplification from Ps-for/Ps-rev amplicons), used in conjunction with SSCP, revealed that environmental contaminants co-extracted with DNA, such as humic acid, significantly reduced primer specificity . SSCP was sensitive enough to reveal template bias in different primer sets . PCR-restriction fragment length-SSCP of Pseudomonas 16S rDNA amplified from soil-extracted DNA revealed distinct differences in sequence representation between extraction methods and showed that greater DNA yield is not synonymous with higher sequence diversity . We, therefore, suggest that DNA extractions from soil should be evaluated not only in terms of quantity and purity, but also in terms of the sequence diversity present . SSCP proved to be a valuable tool for the assessment of the methodologies commonly used in PCR-mediated microbial ecology studies.

Contemp Top Lab Anim Sci, 2001 Jul, 40(4), 32 - 5
Exclusion of mouse hepatitis virus from a filtered, plastic rodent shipping container during an in transit field challenge; Orcutt RP et al.; Although leading suppliers of laboratory mice and rats continue to use filtered shipping boxes to protect their animals from contamination during transport to the end user, no information had been available in the literature to demonstrate that any of these boxes actually accomplish this task . To test this hypothesis, 12 plastic shipping boxes with filters and tight-fitting lids and six cardboard shipping boxes without filters (controls) were each stocked with adult, adventitious disease-free mice . All 18 shipping boxes were transported to a facility housing a breeding colony of mice enzootically infected with four murine viruses, including mouse hepatitis virus (MHV), and were placed inside the colony for 15 h . The boxes were then transported to a commercial testing laboratory, at which the animals were aseptically removed and were held in microisolation cages for 28 days, after which their sera tested for antibody to all four murine viruses . All serum samples from mice held in the control boxes were positive for antibody to MHV, whereas sera from all mice held in filtered boxes were negative for antibody to any of the four viruses . This study demonstrates that at least one type of filtered shipping container protects mice from a field challenge of MHV . To the best of our knowledge, this is the first documentation of any microbial efficacy testing conducted on filtered shipping containers for laboratory animals.

Adv Microb Physiol, 2001, 45, 271 - 340
Flux analysis: a basic tool of microbial physiology; Holms H; Flux analysis (FA) is a means of organizing data to show flux through the central metabolic pathways (CMPs) . It quantifies flux from uptake of carbon to the outputs of the CMPs, which are the precursors used for biosynthesis, acetate excretion and CO2 . Fluxes to precursors reflect the commands of the genome and acetate excretion balances fluxes to precursor supply when uptake exceeds the capacity of the CMPs to allocate carbon in exactly the correct amount to each precursor . No other products have been detected in 11 phenotypes of Escherichia coli ML308 . FA of each of these 11 phenotypes (with some additional variations in culture conditions, some selected mutations and one genetic construct) are shown as flux (mol (kg dry weight biomass)-1 h-1) and are the starting point for further exploration of the physiology of E . coli: FAs suggest the possibility of four strategies to reduce acetate excretion and these have been tested in two of the phenotypes (glucose and pyruvate) . All are successful to some degree but results are not always what were expected . FA of such interventions suggest that some 'global' control mechanisms operate in E . coli ML308 independent of carbon source . There is a division in the CMPs between those pathways that use phosphorylated intermediates and those that do not and these, in turn, are divided into the Krebs cycle and the C2 and C3 monocarboxylic acids . Altogether, there are four 'compartments' and each contains intermediates that are also precursors.

Eur J Immunol, 2001 Jul, 31(7), 2236 - 45
IFN-alpha and IL-18 synergistically enhance IFN-gamma production in human NK cells: differential regulation of Stat4 activation and IFN-gamma gene expression by IFN-alpha and IL-12; Matikainen S et al.; IFN-gamma, a product of NK and T cells, is a key cytokine contributing innate and adaptive immunity . IFN-gamma production is induced via direct cell-cell contacts with APC and IFN-gamma -producing cells or by cytokines . During microbial infections macrophage-derived IFN-alpha, IL-12, and IL-18 enhance IFN-gamma production and Th1 response . Here we show that IFN-alpha in combination with IL-18 very efficiently induces IFN-gamma expression also in primary, nonactivated NK cells and in NK-92 cell line . Comparison of the kinetics of IFN-gamma mRNA expression in nonactivated NK cells, NK-92 cells and activated T cells stimulated with IFN-alpha or IL-12 revealed that, although both of these cytokines directly up-regulate IFN-gamma mRNA expression, its levels remain elevated much longer with IL-12 stimulation . In both NK cells and T cells, Stat4 is known to be critical in IL-12 and IFN-alpha signaling . We show that Stat4 activation is transient in cells stimulated with IFN-alpha, whereas IL-12 induces more long-lasting activation of the transcription factor . This prolonged activation of IFN-gamma gene by IL-12 may result in more efficient IFN-gamma production compared to that of IFN-alpha . Our results demonstrate that IFN-alpha and IL-18 are important innate cytokines in inducing NK cell IFN-gamma production.

Plant Cell, 2001 Jul, 13(7), 1527 - 40
Evidence for an important role of WRKY DNA binding proteins in the regulation of NPR1 gene expression; Yu D et al.; The Arabidopsis NPR1 gene is a positive regulator of inducible plant disease resistance . Expression of NPR1 is induced by pathogen infection or treatment with defense-inducing compounds such as salicylic acid (SA) . Transgenic plants overexpressing NPR1 exhibit enhanced resistance to a broad spectrum of microbial pathogens, whereas plants underexpressing the gene are more susceptible to pathogen infection . These results suggest that regulation of NPR1 gene expression is important for the activation of plant defense responses . In the present study, we report the identification of W-box sequences in the promoter region of the NPR1 gene that are recognized specifically by SA-induced WRKY DNA binding proteins from Arabidopsis . Mutations in these W-box sequences abolished their recognition by WRKY DNA binding proteins, rendered the promoter unable to activate a downstream reporter gene, and compromised the ability of NPR1 to complement npr1 mutants for SA-induced defense gene expression and disease resistance . These results provide strong evidence that certain WRKY genes act upstream of NPR1 and positively regulate its expression during the activation of plant defense responses . Consistent with this model, we found that SA-induced expression of a number of WRKY genes was independent of NPR1.

Chromosome Res, 2001, 9(5), 345 - 55
Key word: chromosome; Zacharias H; The word chromosome has survived for over 100 years, because it succinctly defines what early cytologists were able to see with the most modern instrument of their time, a light microscope . It was introduced in a review that became widely known and was published almost simultaneously in German, English and French (Waldeyer 1888, 1889, 1890a, 1890b) . In the late 19th century, these three languages were in strong competition for international status as the idiom of science . At the same time, Greek was also considered as a candidate for a nationalistically neutral language of science, and it seems more than coincidence that the word {Greek letters: see text} matches well the coherent Greek terminology used to describe the cell cycle in mitosis as well as meiosis . Emil Heitz (1935) maintained--in the face of reactionary German efforts to replace the term--that in using "the ineradicable word chromosome we think last of all that it indicates a body, that stains intensely," . Significantly, the key word is no longer restricted to eukaryotes, but has been readily adopted by microbial geneticists (Heidelberg el al . 2000) and acknowledged as defining the elementary unit of genomic partition.

J Chem Ecol, 2001 Apr, 27(4), 807 - 29
Can simultaneous inhibition of seedling growth and stimulation of rhizosphere bacterial populations provide evidence for phytotoxin transfer from plant residues in the bulk soil to the rhizosphere of sensitive species?
Staman K, Blum U, Louws F, Robertson D.
In order to demonstrate that allelopathic interactions are occurring, one must, among other things, demonstrate that putative phytotoxins move from plant residues on or in the soil, the source, through the bulk soil to the root surface, a sink, by way of the rhizosphere . We hypothesized that the incorporation of phytotoxic plant residues into the soil would result in a simultaneous inhibition of seedling growth and a stimulation of the rhizosphere bacterial community that could utilize the putative phytotoxins as a sole carbon source . If true and consistently expressed, such as relationship would provide a means of establishing the transfer of phytotoxins from residue in the soil to the rhizosphere of a sensitive species under field conditions . Presently, direct evidence for such transfer is lacking . To test this hypothesis, cucumber seedlings were grown in soil containing various concentrations of wheat or sunflower tissue . Both tissue types contain phenolic acids, which have been implicated as allelopathic phytotoxins . The level of phytotoxicity of the plant tissues was determined by the inhibition of pigweed seedling emergence and cucumber seedling leaf area expansion . The stimulation of cucumber seedling rhizosphere bacterial communities was determined by the plate dilution frequency technique using a medium containing phenolic acids as the sole carbon source . When sunflower tissue was incorporated into autoclaved (to reduce the initial microbial populations) soil, a simultaneous inhibition of cucumber seedling growth and stimulation of the community of phenolic acid utilizing rhizosphere bacteria occurred . Thus, it was possible to observe simultaneous inhibition of cucumber seedlings and stimulation of phenolic acid utilizing rhizosphere bacteria, and therefore provide indirect evidence of phenolic acid transfer from plant residues in the soil to the root surface . However, the simultaneous responses were not sufficiently consistent to be used as a field screening tool but were dependent upon the levels of phenolic acids and the bulk soil and rhizosphere microbial populations present in the soil . It is possible that this screening procedure may be useful for phytotoxins that are more unique than phenolic acids.

Crit Care Med, 2001 Jul, 29(7 Suppl), S13 - 5
Macrophage migration inhibitory factor and innate immune responses to bacterial infections; Froidevaux C et al.; OBJECTIVES: To review the role of macrophage migration inhibitory factor (MIF) in host responses to infection and to explore the potential of MIF as a novel target for therapeutic intervention in patients with severe sepsis and septic shock . DATA SOURCES: Published articles on the role of MIF in innate immune responses against microbial pathogens . DATA SUMMARY: MIF has emerged recently as an important effector molecule of the innate immune system . MIF is expressed constitutively by monocytes/macrophages, T cells, B cells, endocrine cells, and epithelial cells . Microbial toxins and cytokines are powerful inducers of MIF release by immune cells . MIF expression is up-regulated during the course of inflammatory and infectious diseases and was found to play an important role in the pathogenesis of sepsis and septic shock . CONCLUSION: Given the role of MIF in innate immune responses against microbial pathogens and in the regulation of inflammatory responses, modulation of MIF production or neutralization of its activity may offer new therapeutic options for the management of patients with sepsis.

Crit Care Med, 2001 Jul, 29(7 Suppl), S2 - 6; discussion S6-7
Sepsis and evolution of the innate immune response; Beutler B et al.; OBJECTIVE: To review the role of the Toll-like receptors (TLR) as the principal sensors used by the innate immune system in the context of the pathologic processes underlying sepsis and septic shock . DATA SOURCES: Literature review . DATA SUMMARY: Through the Toll-like receptors, macrophages and other defensive cells "see" endotoxin (TLR4), peptidoglycan (TLR2), and bacterial DNA (TLR9) . Representatives of the family predated the divergence of plants and animals and, at that time, had already acquired a defensive function . The strengths and liabilities of the innate immune system, which defends against infection and which also may cause shock and death, are rooted in its ancient origins . In the current era of shock research, the nature of the signals that Toll-like receptors transduce and the effects of genetic variation on microbial sensing are two major challenges.

FEMS Microbiol Lett, 2001 Jul 10, 201(1), 1 - 7
Bacterial virulence: can we draw the line?
Wassenaar TM, Gaastra W.
The molecular approach to microbial pathogenesis has resulted in an impressive amount of data on bacterial virulence genes . Bacterial genome sequences rapidly add candidate virulence genes to electronic databases . The interpretation of this overwhelming information is obscured because every gene involved in pathogenicity is called a virulence gene, regardless of its function in the complex process of virulence . This review summarizes the changing concept of bacterial virulence and the detection and identification strategies followed to recognize virulence genes . A refined definition of virulence genes is proposed in which the function of the gene in the virulence process is incorporated . We propose to include the life-style of bacteria in the assessment of their putative virulence genes . A universal nomenclature in analogy to the EC enzyme numbering system is proposed . These recommendations would lead to a better insight into bacterial virulence and a more precise annotation of (putative) virulence genes, which would enable more efficient use of electronic databases.

Environ Pollut, 2001, 114(1), 129 - 36
Toxicological response of a bioluminescent microbial assay to Zn, Pb and Cu in an artificial soil solution: relationship with total metal concentrations and free ion activities; Ritchie JM et al.; The relationship between toxicological response and both total concentrations and free ion activities of Pb, Cu and Zn in an artificial soil solution has been investigated using lux-marked Escherichia coli HB101 (pUCD607) as a bioassay . SO4(2-) (as K2SO4) was added as an inorganic complexing agent up to 0.01 M representing the range of ionic strengths found in soil solutions and giving a wide range of free metal ion activities . EC50 values expressed in terms of concentration, varied significantly with K2SO4 molarity for all metals . However, when EC50 values were expressed in terms of free ion activity they were not significantly different for Pb and Zn, supporting the free ion activity model . Conversely, EC50 values expressed as free Cu activity did vary significantly with K2SO4 molarity, possibly due to a greater degree of adsorption of Cu onto inactive sites on the cell surfaces than for Zn and Pb . Linear regression analysis of bioluminescence on free ion activity revealed significant correlations for each metal above the toxicity threshold . In conclusion, lux-marked E . coli is suitable for investigating the toxicity of metal ions and complexes in non saline systems although cell surface adsorption effects could be important for some metals, e.g . Cu.

Adv Anat Embryol Cell Biol, 2001, 160, III - IX, 1-91
Carbohydrate expression in the intestinal mucosa; Sharma R et al.; The understanding of mechanisms responsible for alterations in mucin synthesis and secretions is essential in elucidating the aetiology of intestinal disorders . The existence of distinct mucins and M-cell transport mechanisms, and their beneficial effects, have long been recognised . Since nutritional and bacterial factors alter the mucin characteristics and are relevant to planning preventative strategies for intestinal diseases, the studies described in this monograph were designed to test the hypothesis that mucin composition and endocrine status of the intestinal tract are altered by dietary constituents and microbial flora . A study of gut-associated lymphoid tissue (GALT) was undertaken to test the hypothesis that lymphocyte-epithelial interactions influence the glycosylation of cells overlying Peyer's patches . The effects of diet and microbial flora were analysed by comparing the data from male Wistar germ-free rats, with conventional or human flora . Such rats were fed either a commercial diet, containing crude fibre, or a purified diet . Bone marrow transfers from syngeneic Balb/c mice to severe combined immunodeficient (SCID) mice were made to induce the formation of GALT . A comparison was made of the glycoconjugate profile of Peyer's patches in the guts of mice and humans . The results of the study showed that feeding a fibre-rich diet to germ-free rats resulted in increased villus-crypt lengths, decreased carboxylated mucin content of goblet cells, increased N-acetylglucosamine and sialic acid residues in the surface goblet cells, and a reduction in the number of endocrine cells in the small intestine . The lectin markers revealed M-cell development in the dome epithelium of the reconstituted SCID mice . Mouse M cells were labelled by fucose-specific lectins but in human Peyer's patches no distinct M-cell-staining pattern was observed . CONCLUSIONS: (1) the interactions between diet and flora alter the mucosal architecture and the activity of endocrine cells; (2) the dietary changes are influential in modifying the epithelial mucin predominantly in the small intestine while the microbial flora influences the mucosal architecture predominantly in the large intestine; (3) the use of bone marrow transplantation from syngeneic mice into SCID mice along with lectin markers for M cells can be used to study the histogenesis of Peyer's patches; (4) the distinct differences between mouse and human Peyer's patches suggest that when considering cell surface glycoconjugates as target molecules appropriate lectin should be used for each species . A future challenge in intestinal epithelial cell biology is identifying the nature and distribution of cell surface receptors for specific dietary components and bacteria.

Vet Surg, 2001 Jul-Aug, 30(4), 380 - 5
Combined omental pedicle grafts and thoracodorsal axial pattern flaps for the reconstruction of chronic, nonhealing axillary wounds in cats; Lascelles BD et al.; OBJECTIVE: To assess the results of an omental pedicle graft in combination with a thoracodorsal axial pattern flap for the reconstruction of chronic nonhealing axillary wounds in 10 cats caused by forelimb entrapment within a collar . STUDY DESIGN: A prospective, clinical trial . ANIMALS USED: Ten client-owned domestic shorthair cats . METHODS: Routine biochemical and hematologic evaluation was performed on each cat, and all were tested for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) . Microbial culture was performed on samples from the wounds . After surgical debridement, omentalization using a vascular pedicle of greater omentum, and closure of the chronic axillary wounds, using a thoracodorsal axial pattern flap, was performed . All excised tissue was examined histologically . RESULTS: The sex distribution was 7 males and 3 females, with a mean age of 3.5 years . The cats had undergone a median number of 3 previous repair attempts over a 1.5- to 25-month period before referral (mean, 10.2 months) . No hematologic or biochemical abnormalities were noted apart from moderately elevated creatine kinase and aspartate transaminase concentrations in some cats . All cats were negative for FIV and FeLV . Histologic examination of resected tissue revealed hair (foreign body) in 2 cats and an unidentified foreign-body reaction in 3 other cats . Complete healing occurred in all cats (mean follow-up period of 21.7 months), with 2 cats requiring further surgery: 1 for flap dehiscence at 4 days after surgery, and 1 for donor-site dehiscence at 4 days after surgery . One other cat developed a large seroma in the axilla that resolved by 10 days following surgery . CONCLUSION: The use of an omental pedicle graft in combination with a thoracodorsal axial pattern flap is the first consistently successful 1-step technique for the management of chronic nonhealing axillary wounds in cats .

Arch Environ Contam Toxicol, 2001 Apr, 40(3), 318 - 26
Toxicity of freshwater sediments in the vicinity of an old sawmill: application of three bioassays; Lyytikainen M et al.; Toxicity of contaminated sediments collected from an old sawmill area and the downstream river-lake system was assessed with three different bioassays . Survival and growth were used as endpoints in subchronic (10-day) test with Chironomus riparius and growth and reproduction in long-term (28-day) test with Lumbriculus variegatus . A microbial bioluminescent direct contact assay, the Flash test, was also included in the test set to measure acute toxicity . In every bioassay, sediment from a pool of the sawmill was found to be toxic, and some adverse effects were found in other sediments as well . The bioassays were then compared to chemical analysis results, which showed the presence of several toxicants . These results could not, however, be directly connected to any individual toxicant, nor did they show any obvious trend downstream from the mill.

Ned Tijdschr Tandheelkd, 2001 Jun, 108(6), 216 - 22
{Diagnosis and therapy of non-odontogenic orofacial infections}; Spijkervet FK et al.; This article discusses the non-odontogenic inflammations of the oral mucosa, connective tissue, bone and temporomandibular joint . Their occurrence, course and treatment are related to the patient's immune status, and to microbial and environmental factors, as is always the case with infectious processes . The article concerns peculiarly several clinical and therapeutic consequences of non-dontogenic orofacial infections.

Plant J, 2001 May, 26(4), 395 - 407
Constitutive salicylic acid-dependent signaling in cpr1 and cpr6 mutants requires PAD4; Jirage D et al.; Salicylic acid (SA)-dependent signaling controls activation of a set of plant defense mechanisms that are important for resistance to a variety of microbial pathogens . Many Arabidopsis mutants that display altered SA-dependent signaling have been isolated . We used double mutant analysis to determine the relative positions of the pad4, cpr1, cpr5, cpr6, dnd1 and dnd2 mutations in the signal transduction network leading to SA-dependent activation of defense gene expression and disease resistance . The pad4 mutation causes failure of SA accumulation in response to infection by certain pathogens, while the other mutations cause constitutively high levels of SA, defense gene expression and resistance . The cpr1 pad4, cpr5 pad4, cpr6 pad4, dnd1 pad4 and dnd2 pad4 double mutants were constructed and assayed for stature, presence of spontaneous lesions, resistance to Pseudomonas syringae and Peronospora parasitica, SA levels, expression of PAD4, PR-1 and PDF1.2, and accumulation of camalexin . We found that the effects of the cpr1 and cpr6 mutations on SA-dependent gene expression are completely dependent on PAD4 function . In contrast, SA accumulation in the lesion-mimic mutant cpr5 is partially PAD4-independent, while in dnd1 and dnd2 mutants it is completely PAD4-independent . A model describing a possible arrangement of activities in the signal transduction network is presented.

Proc Natl Acad Sci U S A, 2001 Jul 3, 98(14), 7940 - 5
Genes linked by fusion events are generally of the same functional category: a systematic analysis of 30 microbial genomes; Yanai I et al.; Recent work in computational genomics has shown that a functional association between two genes can be derived from the existence of a fusion of the two as one continuous sequence in another genome . For each of 30 completely sequenced microbial genomes, we established all such fusion links among its genes and determined the distribution of links within and among 15 broad functional categories . We found that 72% of all fusion links related genes of the same functional category . A comparison of the distribution of links to simulations on the basis of a random model further confirmed the significance of intracategory fusion links . Where a gene of annotated function is linked to an unclassified gene, the fusion link suggests that the two genes belong to the same functional category . The predictions based on fusion links are shown here for Methanobacterium thermoautotrophicum, and another 661 predictions are available at http://fusion.bu.edu.

Proc Natl Acad Sci U S A, 2001 Jul 3, 98(14), 7684 - 9
Functional dynamics in the active site of the ribonuclease binase; Wang L et al.; Binase, a member of a family of microbial guanyl-specific ribonucleases, catalyzes the endonucleotic cleavage of single-stranded RNA . It shares 82% amino acid identity with the well-studied protein barnase . We used NMR spectroscopy to study the millisecond dynamics of this small enzyme, using several methods including the measurement of residual dipolar couplings in solution . Our data show that the active site of binase is flanked by loops that are flexible at the 300-micros time scale . One of the catalytic residues, His-101, is located on such a flexible loop . In contrast, the other catalytic residue, Glu-72, is located on a beta-sheet, and is static . The residues Phe-55, part of the guanine base recognition site, and Tyr-102, stabilizing the base, are the most dynamic . Our findings suggest that binase possesses an active site that has a well-defined bottom, but which has sides that are flexible to facilitate substrate access/egress, and to deliver one of the catalytic residues . The motion in these loops does not change on complexation with the inhibitor d(CGAG) and compares well with the maximum k(cat) (1,500 s(-1)) of these ribonucleases . This observation indicates that the NMR-measured loop motions reflect the opening necessary for product release, which is apparently rate limiting for the overall turnover.

J Invertebr Pathol, 2001 May, 77(4), 269 - 79
Pathological and physiological changes in the South African freshwater crab Potamonautes warreni calman induced by microbial gill infestations; Schuwerack PM et al.; The impact of microbial gill infestations on the pathology and physiology of the freshwater crab Potamonautes warreni was investigated by comparison of infested and uninfested crab populations from, respectively, a polluted and an unpolluted site along the Mooi River, North West Province, South Africa . Heavy gill infestations by bacteria (70%), peritrichous ciliates such as Lagenophrys sp . (15%), Zoothamnium sp . (10%), and Epistylis sp . (5%), and motile protozoans resulted in species-specific lesions in the gill epithelia of P . warreni and physiological changes in crabs from the polluted site . Bacterial colonies enmeshed in polysaccharide-like films produced indentations of the gill cuticular surfaces and dissociation of microvillous membranes at the basal zone of epithelial cells of gill lamellae of P . warreni . Lagenophrys sp . induced large subcuticular spaces with an unfolding or resorption of the plasma membrane in the gill epithelia . The attachment of stalks of Zoothamnium and Epistylis resulted in dilation of lamellar tissues, the formation of vacuoles, and an increase in subcuticular spaces in the epithelia . Physiological changes in infested crabs included significant differences (P = 0.001) in increments of wet body mass and a reduced growth rate over time compared with uninfested crabs . The specific oxygen consumption (M(O2)) in rested infested crabs significantly increased (31.29 +/- 5.8 micromol O2/kg/min) compared with the M(O2) in uninfested crabs (27.92 +/- 5.6 micromol O2/kg/min; P = 0.009) . The heart rate of infested rested P . warreni was significantly lower (40.77 +/- 13.79 beats/min; P < 0.02) than that in uninfested crabs (61.09 +/- 29.02 beats/min) but the heart rate of infested crabs increased significantly with body mass (r = 0.53, P = 0.02) . These findings suggest an interrelationship among organic pollution, microbial gill infestations, and specific pathological and physiological responses in the crab host . The role of P . warreni and its microbial gill communities as bioindicators of pollution are discussed .

J Autoimmun, 2001 Jun, 16(4), 479 - 84
Crossreactivity of human anti-dsDNA antibodies to phosphorylcholine: clues to their origin; Sharma A et al.; The presence of anti-double stranded DNA (dsDNA) antibodies is a serological diagnostic feature of systemic lupus erythematosus (SLE), an autoimmune rheumatic disorder . Studies by several investigators have suggested that a response to a microbial antigen can lead to the induction of SLE-like autoimmunity, in both humans and mice, since anti-dsDNA antibodies have been shown to crossreact with foreign antigens . In particular, anti-DNA antibodies have been shown to crossreact with phosphorylcholine (PC), a dominant epitope on pneumococcal cell wall polysaccharide . We have investigated the binding characteristics of human polyclonal anti-DNA antibodies from the sera of SLE patients . In this study we show that the DNA binding of polyclonal serum derived antibodies can be partially inhibited by phosphorylcholine (PC) . The binding of affinity-purified anti-DNA antibodies from the sera of patients with SLE was also found to be inhibited by PC . We further demonstrated that the serum IgG1 (T dependent) anti-DNA response was more likely to crossreact with PC than the IgG2 (T independent) response to DNA . The studies suggest there may be a T dependent and T independent response to DNA with the T dependent response displaying more crossreactivity with microbial antigen .

Water Sci Technol, 2001, 43(10), 179 - 86
Bacterial responses to ultraviolet irradiation; Blatchley ER 3rd et al.; The UV dose-response behavior of laboratory cultures of waterborne bacteria were examined for UV doses ranging from ca . 0-100 mW.s/cm2 using a collimated-beam reactor . Specific physiological responses measured in these tests included viability (ability to reproduce) and respiration (oxygen uptake rate) . The results of these exposures indicated that resistance to UV-imposed loss of viability in E . coli cultures can be partially attributed to agglomeration during the irradiation process . From these results, it is conjectured that a bacterial population may be comprised of two sub-populations: one with low resistance (discrete or paired cells) and a second with high resistance (bacterial aggregates) . A small fraction of the high-resistance portion of the population appears to be essentially unaffected by UV irradiation, thereby causing a discontinuity in the measured dose-response behavior . Moreover, the dose-response behavior of the highly resistant fraction is variable and difficult to describe quantitatively . The basis of these statements and most information in the literature is microbial viability as quantified by the membrane filtration assay . In contrast to these findings, the results of analyses for bacterial activity (respiration) suggest that comparatively little change in the population can be found to result from UV irradiation . This suggests that UV radiation accomplishes inactivation of the bacteria, but does not "kill" the bacterial cells per se, thereby highlighting the importance of considering bacterial repair processes in the design of UV disinfection systems.

J Leukoc Biol, 2001 Jul, 70(1), 142 - 8
Signaling pathways initiated in macrophages after engagement of type A scavenger receptors; Coller SP et al.; Scavenger receptors are macrophage cell surface molecules associated with endocytic uptake of lipoproteins and binding of microbial ligands . Macrophage class A scavenger receptors (SR-As) interact with ligands to induce cellular signaling leading to gene transcription and cytokine release . We used inhibitors of early and late signaling to block SR-A-mediated polyinosinic-polycytidilic acid (poly I:C) and lipoteichoic acid (LTA) activation of RAW 264.7 macrophages . Effects of multiple inhibitors on tumor necrosis factor (TNF)-alpha release were monitored to determine requirements for inflammatory cytokine production . Cycloheximide, monodansylcadaverine, and cytochalasin B all blocked TNF-alpha release from macrophages stimulated with LTA or poly I:C, whereas monensin only nominally reduced TNF-alpha production . Selected inhibitors of downstream signaling events reduced SR-A-dependent TNF-alpha release by >95% after stimulation with either ligand, whereas others were ineffective . The PKC inhibitor H7 reduced LTA-dependent secretion of TNF-alpha by 94% but inhibited poly I:C-dependent TNF-alpha production only by 50% . Priming of RAW 264.7 cells with interferon-gamma potentiated the response to poly I:C but did not alter inhibitor effects . These results demonstrated that for both ligands tested here, early events of receptor internalization are requisite for cellular activation . The response pattern suggests that tyrosine phosphorylation and activation of the MAP kinase pathway are key components of SR-A-mediated signal transduction cascades.

Blood, 2001 Jul 15, 98(2), 436 - 41
Improved superoxide-generating ability by interferon gamma due to splicing pattern change of transcripts in neutrophils from patients with a splice site mutation in CYBB gene; Ishibashi F et al.; Chronic granulomatous disease (CGD) is an inherited disorder of host defense against microbial infections caused by defective activity of the phagocyte NADPH oxidase . Based on an increase of neutrophil superoxide-generating ability in response to interferon gamma (IFN-gamma) in a single patient with CGD, multicentered group studies demonstrated a beneficial effect of prophylactic IFN-gamma . However, no apparent increase of the phagocyte superoxide generation was found in patients enrolled in these studies . The present report offers an additional kindred in whom an IFN-gamma-dependent increase in neutrophil superoxide production was observed in 3 affected patients . The defect in the CYBB gene for gp91-phox was identified as an otherwise silent mutation adjacent to the third intron of the CYBB gene that alters messenger RNA splicing . By molecular analysis, significant differences were found in the splicing pattern of CYBB gene transcripts in patient neutrophils between 1 and 25 days after administration of IFN-gamma . Furthermore, a complete transcript containing the missing exons could be detected in all specimens after the treatment . The changes in the splicing pattern of the transcripts and the prolonged effect on superoxide-generating ability of patient neutrophils indicate that IFN-gamma induced a partial correction of the abnormal splicing of CYBB gene transcripts in myeloid progenitor cells.

Int J Hyg Environ Health, 2001 May, 203(4), 301 - 10
GIS-based analysis of drinking-water supply structures: a module for microbial risk assessment; Kistemann T et al.; Water-related infections constitute an important health impact world-wide . A set of tools serving for Microbial Risk Assessment (MRA) of waterborne diseases should comprise the entire drinking-water management system and take into account the Hazard Analysis and Critical Control Point (HACCP) concept which provides specific Critical Control Points (CCPs) reflecting each step of drinking-water provision . A Geographical Information System (GIS) study concerning water-supply structure (WSS) was conducted in the Rhein-Berg District (North Rhine-Westphalia, Germany) . As a result, suitability of the existing water databases HYGRIS (hydrological basis geo-information system) and TEIS (drinking-water recording and information system) for the development of a WSS-GIS module could be demonstrated . Spatial patterns within the integrated raw and drinking-water data can easily be uncovered by GIS-specific options . The application of WSS-GIS allows a rapid visualization and analysis of drinking-water supply structure and offers huge advantages concerning microbial monitoring of raw and drinking water as well as recognition and investigation of incidents and outbreaks . Increasing requests regarding health protection and health reporting, demands for a better outbreak management and water-related health impacts of global climate change are major challenges of future water management to be tackled with methods including spatial analysis . GIS is assumed to be a very useful tool to meet these requirements.

Int J Cancer, 2001 Aug 1, 93(3), 307 - 16
Thiolutin, an inhibitor of HUVEC adhesion to vitronectin, reduces paxillin in HUVECs and suppresses tumor cell-induced angiogenesis; Minamiguchi K et al.; Recent studies have shown that integrin alpha v beta 3, a receptor for vitronectin, plays an important role in tumor-induced angiogenesis and tumor growth and that antagonists of alpha v beta 3 inhibit angiogenic processes including endothelial cell adhesion and migration . On the other hand, most inhibitors of integrin alpha v beta 3 are peptide antagonists that include the Arg-Gly-Asp (RGD) motif . We therefore reasoned that non-peptide inhibitors of endothelial cell adhesion to vitronectin might be useful for inhibition of tumor angiogenesis in vivo . We screened for low-molecular-weight natural products able to inhibit adhesion of human umbilical vein endothelial cells (HUVECs) to vitronectin, and pyrrothine group compounds including aureothricin, thioaurin and thiolutin were isolated from microbial culture broths . Of these compounds, thiolutin inhibited adhesion of HUVECs to vitronectin the most effectively (IC(50), 0.83 microM) . In vivo experiments showed that thiolutin significantly suppressed angiogenesis induced by tumor cells (S-180), a pathological form of neovascularization, in a mouse dorsal air sac assay system . To explore the mechanism of inhibition of HUVEC adhesion to vitronectin by thiolutin, we examined the effect of this agent on intracellular cell adhesion signaling . We found that the amount of paxillin in HUVECs was significantly reduced by thiolutin treatment, while those of other focal adhesion proteins including vinculin and focal adhesion kinase (FAK) were not . Metabolic labeling experiments showed that thiolutin enhanced degradation of paxillin in HUVECs . Protease inhibitors (MG115 and E64-D) decreased the rate of degradation of the paxillin induced by thiolutin and partially restored thiolutin-induced inhibition of HUVEC adhesion to vitronectin . Based on these findings, we concluded that thiolutin, an inhibitor of HUVEC adhesion to vitronectin, reduces the paxillin level in HUVECs and suppresses tumor cell-induced angiogenesis in vivo .

Biodegradation, 2000, 11(4), 229 - 37
Hydrolysis of newspaper polysaccharides under sulfate reducing and methane producing conditions; Pareek S et al.; The initial decomposition rates of cellulose and hemicellulose were measured using toluene to specifically inhibit the microbial uptake of hydrolysis products during the degradation of newspaper under sulfate reducing and methane producing conditions . The amount of glucose and xylose accumulation in the first 2 weeks of incubation period was higher in the sulfate reducing condition compared to the methane producing condition . It was estimated that 28 and 6% of initially loaded cellulose in the sulfate reducing condition and the methane producing condition was hydrolyzed, respectively . Accordingly, the newspaper-cellulose hydrolysis rate constant was estimated to be 6.7 times higher in sulfate reducing condition than in methane producing condition . Based on the glucose accumulation patterns, when sulfate reducing bacteria (SRB) were inhibited by anthraquinone and molybdate (Na2MoO4), it may be suggested that SRB might have contributed to the hydrolysis of cellulose, while their effect on the hydrolysis of hemicellulose could not be elucidated.

Science, 2001 Jun 29, 292(5526), 2492 - 5
Contribution of aerobic photoheterotrophic bacteria to the carbon cycle in the ocean; Kolber ZS et al.; The vertical distribution of bacteriochlorophyll a, the numbers of infrared fluorescent cells, and the variable fluorescence signal at 880 nanometers wavelength, all indicate that photosynthetically competent anoxygenic phototrophic bacteria are abundant in the upper open ocean and comprise at least 11% of the total microbial community . These organisms are facultative photoheterotrophs, metabolizing organic carbon when available, but are capable of photosynthetic light utilization when organic carbon is scarce . They are globally distributed in the euphotic zone and represent a hitherto unrecognized component of the marine microbial community that appears to be critical to the cycling of both organic and inorganic carbon in the ocean.

Br J Nutr, 2001 Jun, 85(6), 689 - 98
Response in hepatic removal of amino acids by the sheep to short-term infusions of varied amounts of an amino acid mixture into the mesenteric vein; Lobley GE et al.; Under conditions of chronic supply the liver removes most amino acids (AA) in excess of net anabolic needs . Little information is available, however, on how acute alterations in AA supply (as might occur with once-daily feeding regimens) are controlled by the liver . Are these also extracted completely in a 'first-pass' manner or are there limitations to hepatic uptake? Furthermore, is the rate of removal 'saturable' (by Michaelis-Menten kinetics) over the range of supply experienced under normal feeding conditions? These questions have been addressed in a study that involved acute (4.5 h) increases in AA supply . Four sheep were prepared with trans-hepatic vascular catheters and were offered a basal diet (equivalent to 1.6xenergy maintenance) throughout . On four occasions, at 7 d intervals, they were infused with various amounts of an AA mixture into the mesenteric vein over a 4.5 h period . The mixture contained fourteen AA in the proportions present in rumen microbial protein . The amounts infused were calculated to provide an additional one, two, three and four times that absorbed from the basal diet . Continuous blood collections were removed over 2 h intervals before (basal diet only) and at 0.5-2.5 and 2.5-4.5 h of AA infusion . Transfers of AA, from the digestive tract and to the liver, were calculated for both plasma and total blood . The recovery of the infused AA across the portal-drained viscera (PDV) was quantitative (100%) only for histidine and proline, the remaining AA were recovered at 56-83 % . These losses correlated with the arterial concentrations and were probably due to removal of AA from the systemic circulation by the tissues of the digestive tract . Despite the wide range of net PDV appearances (i.e . absorbed plus infused), the percentage of most AA removed by the liver remained constant, but the percentage varied with AA (from 34 for proline to 78 for tryptophan for blood transfers) . Thus, even when supply was increased 5-fold over baseline there was no indication that the transport into the liver declined, indeed the absolute removals continued to increase . In contrast, the branched-chain AA (isoleucine, leucine and valine) did not exhibit constant percentage extractions . Their percentage extractions were always the lowest (16, 10 and 25 respectively) and tended to decline at the highest infusion rates, indicative of saturation in hepatic transport and/or metabolism . The arterial concentrations of all infused AA increased with rate of infusion, again indicative that the liver did not extract all the net AA available across the PDV . Absolute amounts removed were similar between plasma and blood, indicating that most of the hepatic transfers occurred from plasma . The fractional rates of transfer from total inflow to the liver (i.e . with re-circulated AA included) were 3- to 4-fold lower than rates based on the amounts absorbed plus infused . The highest percentage extraction for total blood inflows was for serine (27), but most were between 6 and 16, except for the branched-chain AA, which were all <1 . Use of percentage extractions based on total inflows are probably more appropriate for development of mathematical models of liver metabolism, and the current data suggest that constant values may be applied . The needs of the liver for specific mechanisms involving phenylalanine and histidine (plasma protein synthesis), glycine (detoxification of xenobiotics) and alanine (gluconeogenesis) probably also require to be included in such models.

J Nat Prod, 2001 Feb, 64(2), 222 - 5
Microbial transformation of ent-kaurenoic acid and its 15-hydroxy derivatives by the SG138 mutant of Gibberella fujikuroi; Barrero AF et al.; Feeding experiments with ent-kaurenoic acid (4), 15 alpha-hydroxy-ent-kaurenoic acid (5), 15 beta-hydroxy-ent-kaurenoic acid (6), and mixtures of 4 plus 5 and 4 plus 6 were conducted using the SG138 mutant of Gibberella fujikuroi, to gain information about the phenotype of this unique strain . The biotransformation of 5 gave 7 beta,15 alpha-dihydroxykaurenolide (9) and 7 beta,15 alpha-dihydroxy-ent-kaurenoic acid (13) . The incubation of 6 produced 7 beta,15 beta-dihydroxy-ent-kaurenoic acid (7) and 7 beta,15 beta-dihydroxykaurenolide (10) . No 15-hydroxylated gibberellins were detected in any of these experiments . The results indicated that a hydroxy group at C-15 does not inhibit 7 beta-hydroxylase activity but in the SG138 strain obstructs the enzymatic ring-B contraction of ent-kaurenoids to gibberellins . Exogenous 4 stimulated both the excretion of ent-kaurene and the fungal metabolism of 5 and 6.

Cytometry, 2001 Jul 1, 44(3), 236 - 46
Monitoring phytoplankton, bacterioplankton, and virioplankton in a coastal inlet (Bedford Basin) by flow cytometry; Li WK et al.; BACKGROUND: To establish the prevailing state of the ecosystem for the assessment of long-term change, the abundance of microbial plankton in Bedford Basin (Nova Scotia, Canada) is monitored weekly by flow cytometry . METHODS: Phytoplankton are detected by their chlorophyll autofluorescence . Those that contain phycoerythrin are designated as Synechococcus cyanobacteria or cryptophyte algae according to the intensity of light scatter . Bacteria and viruses are stained with DNA-binding fluorochromes and detected by green fluorescence . Distinction is made between bacterial and viral subpopulations exhibiting high and low fluorescence . RESULTS: Time series data are presented for weekly observations from 1991 to 2000 . Weekly averages are computed for the complete annual cycle of temperature, salinity, river discharge, nitrate, phosphate, silicate, chlorophyll, total phytoplankton including Synechococcus and cryptophytes, total bacteria including high and low-fluorescence subpopulations, and total viruses including high and low-fluorescence subpopulations . CONCLUSIONS: The microbial biomass in the surface water of Bedford Basin is dominated by phytoplankton . The spring bloom of phytoplankton represents a maximum in algal biovolume, but not in cell number . Phytoplankton, bacteria, and viruses all attain their annual numerical maxima between the summer solstice and the autumn equinox . A vigorous microbial loop and viral shunt is envisioned to occur in the summer .

Cytometry, 2001 Jul 1, 44(3), 218 - 25
Detection of subgroups from flow cytometry measurements of heterotrophic bacterioplankton by image analysis; Andreatta S et al.; BACKGROUND: Flow cytometry is an invaluable tool for the analysis of large series of samples in aquatic microbial ecology . However, analysis of the resulting data is often inefficient or does not reflect the complexity of natural communities . Because bacterioplankton assemblages frequently fall into several clusters with respect to their cellular properties, these subgroups seem to be a promising level of abstraction . Image analysis was used to detect clusters from flow cytometry data . The method was tested on a bacterial community under heavy protozoan grazing pressure . METHODS: A bivariate histogram of flow cytometry data was transformed into a gray-scale image for image analysis . After low-pass filtration, regional maxima were delimited by a watershed algorithm . The resulting areas were then used as gates on the original measurements . RESULTS: Three clusters could be detected from the bacterial assemblage . Protozoan grazing had a strong impact on the bacterial community, which could be analyzed in detail at the level of individual subgroups . CONCLUSIONS: Investigation at the level of bacterial subgroups allowed a more detailed analysis than whole-community statistics and delivered essential and ecologically meaningful information . Image analysis proved to be an adequate tool to detect the subgroups without a priori knowledge .

Microbiology, 2001 Jul, 147(Pt 7), 1719 - 29
Repeated ruminal dosing of Ruminococcus spp . does not result in persistence, but changes in other microbial populations occur that can be measured with quantitative 16S-rRNA-based probes; Krause DO et al.; Digestibility of fibre in ruminants may be improved by the introduction of highly fibrolytic strains of ruminal bacteria . This approach may be feasible if, for example, strains of Ruminococcus that are significantly more fibrolytic than the normal population of Ruminococcus are used for inoculation purposes . Introduced strains of bacteria, irrespective of ecosystem, often decline after inoculation, and in this study, highly fibrolytic strains of Ruminococcus were continuously dosed to ensure that measurements of fibre digestion were made in the presence of significant numbers of the introduced bacteria . During dosing the total culturable count increased significantly (P<0.05), but declined post-dosing . The level of dosed Ruminococcus, and total Ruminococcus, Fibrobacter succinogenes and eukaryotes measured by 16S rRNA probes increased significantly (P<0.05) during the dosing period, but also declined post-dosing . When in vitro nylon bag digestibility, feed intake or whole-tract digestibility was measured, no improvement could be measured.

Biotechnol Bioeng, 2001 Sep 5, 74(5), 424 - 34
Mechanistic study of microbial control of hydrogen sulfide production in oil reservoirs; Nemati M et al.; Microbial control of biogenic production of hydrogen sulfide in oil fields was studied in a model system consisting of pure cultures of the nitrate-reducing, sulfide-oxidizing bacterium (NR-SOB) Thiomicrospira sp . strain CVO and the sulfate-reducing bacterium (SRB) Desulfovibrio sp . strain Lac6, as well as in microbial cultures enriched from produced water of a Canadian oil reservoir . The presence of nitrate at concentrations up to 20 mM had little effect on the rate of sulfate reduction by a pure culture of Lac6 . Addition of CVO imposed a strong inhibition effect on production of sulfide . In the absence of added nitrate SRB we were able to overcome this effect after an extended lag phase . Simultaneous addition of CVO and nitrate stopped the production of H2S immediately . The concentration of sulfide decreased to a negligible level due to nitrate-dependent sulfide oxidation activity of CVO . This was not prevented by raising the concentration of Na-lactate, the electron donor for sulfate reduction . Similar results were obtained with enrichment cultures . Enrichments of produced water with sulfide and nitrate were dominated by CVO, whereas enrichments with sulfate and Na-lactate were dominated by SRB . Addition of an NR-SOB enrichment to an SRB enrichment inhibited the production of sulfide . Subsequent addition of sufficient nitrate caused the sulfide concentration to drop to zero . A similar response was seen in the presence of nitrate alone, although after a pronounced lag time, it was needed for emergence of a sizable CVO population . The results of the present study show that two mechanisms are involved in microbial control of biogenic sulfide production . First, addition of NR-SOB imposes an inhibition effect, possibly by increasing the environmental redox potential to levels which are inhibitory for SRB . Second, in the presence of sufficient nitrate, NR-SOB oxidize sulfide, leading to its complete removal from the environment . Successful microbial control of H2S in an oil reservoir is crucially dependent on the simultaneous presence of NR-SOB (either indigenous population or injected) and nitrate in the environment .

Clin Diagn Lab Immunol, 2001 Jul, 8(4), 702 - 5
In vitro hydroxyurea decreases Th1 cell-mediated immunity; Weinberg A; Hydroxyurea (HU) is used in the treatment of hematologic disorders and is sometimes added to antiretroviral combination therapy to potentiate human immunodeficiency virus (HIV) suppression . However, HU has toxic effects on rapidly dividing cells, including the effectors of the immune response . To determine whether HU affects specific T-cell responses, we measured lymphocyte proliferation and cytokine production in response to microbial antigen and mitogen stimulation in the presence of added HU (10 to 1,000 microM) . HU treatment of peripheral blood mononuclear cells obtained from HIV-infected patients and uninfected controls decreased lymphocyte proliferation and gamma interferon production compared with untreated cells . Interleukin-2 (IL-2) and IL-10 production was not affected by HU . The HU-mediated decrease of lymphocyte proliferation was similar in peripheral blood mononuclear cells from HIV-infected patients and from uninfected controls . The inhibitory effect of HU required continuous exposure to the drug and could be reverted by washing the drug out of the culture environment . These findings suggest that HU-containing therapeutic regimens might decrease Th1-cell-mediated immune responses in vivo.

J Colloid Interface Sci, 2001 Jul 15, 239(2), 328 - 333
Heteroflocculation of Sulfate Polystyrene Latex and Anticarsia gemmatalis Nucleopolyhedrovirus as a Model System for Studying Sunlight Protection; de Moraes Lessa M et al.; Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) is a baculovirus widely used as a pest control agent . Data on field persistence of this microbial insecticide reveal that sunlight is the most destructive of the environmental factors . The introduction of a physical barrier to protect the baculovirus from sunlight has been proposed . In the present work we report on the coating of a baculovirus surface with a uniform layer of smaller particles . The coating was carried out at pH 3, a condition where the baculovirus surface becomes positively charged and can be covered by sulfate polystyrene latex particles . The heteroflocculation was assessed by isotherm measurements and scanning electron microscopy . High-affinity isotherms were obtained for the two sizes of latex used, and the number of latex particles bound per baculovirus was not affected when pH was changed back to neutral range (5<pH<7) . Two cycles of centrifugation and washing with deionized water did not wash the sulfate polystyrene from the polyhedron surface .

Glycobiology, 2001 May, 11(5), 365 - 72
Fucosylated human milk oligosaccharides vary between individuals and over the course of lactation; Chaturvedi P et al.; Specific human milk oligosaccharides, especially fucosylated neutral oligosaccharides, protect infants against specific microbial pathogens . To study the concentrations of individual neutral oligosaccharides during lactation, a total of 84 milk samples were obtained from 12 women at 7 time periods during weeks 1-49 postpartum . The neutral oligosaccharides from each sample were isolated, perbenzoylated, resolved, and quantified by reversed-phase high-performance liquid chromatography . The resultant oligosaccharide peaks, identified by co-elution with authentic standards and mass spectrometry, ranged in size from tri- to octasaccharides . The total concentration of oligosaccharides declined over the course of lactation; the mean concentration at 1 year was less than half that in the first few weeks postpartum . One of the 12 donors produced milk fucosyloligosaccharides that were essentially devoid of alpha1,2 linkages (but contained alpha1,3- and alpha1,4-linked fucose) until late in lactation, consistent with the nonsecretor phenotype . In milk samples from the remaining 11 donors, fucosyloligosaccharides containing alpha1,2-linked fucose were prevalent, and their profiles were distinct from those of fucosyloligosaccharides devoid of alpha1,2-linked fucose . The ratio of alpha1,2-linked oligosaccharide concentrations to oligosaccharides devoid of alpha1,2-linked fucose changed during the first year of lactation from 5:1 to 1:1 . Furthermore, the absolute and the relative concentrations of individual oligosaccharides varied substantially, both between individual donors and over the course of lactation for each individual . The patterns of milk oligosaccharides among individuals suggest the existence of many genotype subpopulations . This variation in individual oligosaccharide concentrations suggests that the protective activities of human milk could also vary among individuals and during lactation.

Appl Environ Microbiol, 2001 Jul, 67(7), 3002 - 9
Ecological physiology of Synechococcus sp . strain SH-94-5, a naturally occurring cyanobacterium deficient in nitrate assimilation; Miller SR et al.; Synechococcus sp . strain SH-94-5 is a nitrate assimilation-deficient cyanobacterium which was isolated from an ammonium-replete hot spring in central Oregon . While this clone could grow on ammonium and some forms of organic nitrogen as sole nitrogen sources, it could not grow on either nitrate or nitrite, even under conditions favoring passive diffusion . It was determined that this clone does not express functional nitrate reductase or nitrite reductase and that the lack of activity of either enzyme is not due to inactivation of the cyanobacterial nitrogen control protein NtcA . A few other naturally occurring cyanobacterial strains are also nitrate assimilation deficient, and phylogenetic analyses indicated that the ability to utilize nitrate has been independently lost at least four times during the evolutionary history of the cyanobacteria . This phenotype is associated with the presence of environmental ammonium, a negative regulator of nitrate assimilation gene expression, which may indicate that natural selection to maintain functional copies of nitrate assimilation genes has been relaxed in these habitats . These results suggest how the evolutionary fates of conditionally expressed genes might differ between environments and thereby effect ecological divergence and biogeographical structure in the microbial world.

Lancet, 2001 Jun 16, 357(9272), 1933 - 6
Pharmacopoeial quality of drugs supplied by Nigerian pharmacies; Taylor RB et al.; BACKGROUND: The quality of medicines available in some less-developed countries is inadequate in terms of content of active ingredient . Reasons for the poor quality of drugs include widespread counterfeiting of medicines in less-developed countries, excessive decomposition of active ingredient as a result of high temperature and humidity, and poor quality assurance during the manufacture of medicinal products . Our aim was to investigate the quality of different drugs obtained from retail pharmacies in two urban areas of Nigeria, and, in instances of poor quality, to ascertain the reason why . METHODS: We randomly collected 581 samples of 27 different drugs from 35 pharmacies in Lagos and Abuja in Nigeria . We analysed the medicines for drug content by validated chromatographic methods, and compared our results with pharmacopoeial requirements . FINDINGS: 279 (48%) samples did not comply with set pharmacopoeial limits, and this proportion was uniform for the various types of drugs tested . Although some preparations contained no active ingredient, most had amounts just outside the pharmacopoeial limits . We identified samples with both too much and too little active drug content . INTERPRETATION: The most probable cause of the poor quality of drugs is absence of adequate quality assurance during manufacture . Substandard drugs sold in the pharmacies of less-developed countries could contribute to global microbial resistance and therapeutic failure of infectious diseases.

Environ Technol, 2001 May, 22(5), 577 - 85
Characterisation and anaerobic batch degradation of materials accumulating in anaerobic digesters treating poultry slaughterhouse waste; Salminen E et al.; We characterised materials accumulating in two failed mesophilic semi-continuous anaerobic digesters treating poultry slaughterhouse waste and, for reference, materials in the two well-performing digesters, to find the anaerobic degradability of these materials and the factors affecting their degradation . We also studied materials accumulating and stratifying in various layers in one of the two well-performing digesters . The material from the most severely failed digesters produced methane sluggishly and did not improve appreciably even with 33 percent dilution suggesting that the recovery of failed process is slow . The methane production was apparently affected by the accumulated long-chain fatty acids, totalling 8.1 g l-1, which degraded slowly . However, the material produced methane in the end, which shows that the failure was reversible . In the well-performing digester, considerable amounts of long-chain fatty acids already floated on top of the digester after 20 hours without mixing, a phenomenon which may have affected their bioavailability and toxicity . However, materials from the top, middle, and bottom layers of the digester were readily and largely methanised by the microbial populations present in them and additional inocula did not markedly enhance the methanation . The results indicate that long-chain fatty acids are apparently the main factor affecting both the failure and recovery of a poultry slaughterhouse waste digester . Thus excessive feeding of lipids into the digester should be avoided.

J Ind Microbiol Biotechnol, 1999 Oct, 23(4-5), 268 - 272
Sphingomonads from marine environments; Cavicchioli R et al.; Sphingomonas species play an important role in the ecology of a range of marine habitats . Isolates and 16S-rRNA clones have been obtained from corals, natural and artificial sources of marine hydrocarbons and eutrophic and oligotrophic waters, and have been isolated as hosts for marine phages . In addition they are found in oceans spanning temperature ranges from polar to temperate waters . While less is known about marine sphingomonads in comparison to their terrestrial counterparts, their importance in microbial ecology is evident . This is illustrated by, for example, the numerical dominance of strain RB2256 in oligotrophic waters . Furthermore, the known marine sphingomonads represent a phylogenetic cross-section of the Sphingomonas genus . This review focuses on our present knowledge of cultured isolates and 16S-rDNA clones from marine environments.

Phytochemistry, 2001 Jul, 57(6), 1035 - 42
NMR studies of molecular structure in fruit cuticle polyesters; Fang X et al.; The cuticle of higher plants functions primarily as a protective barrier for the leaves and fruits, controlling microbial attack as well as the diffusion of water and chemicals from the outside environment . Its major chemical constituents are waxes (for waterproofing) and cutin (a structural support polymer) . However, the insolubility of cutin has hampered investigations of its covalent structure and domain architecture, which are viewed as essential for the design of crop protection strategies and the development of improved synthetic waterproofing materials . Recently developed strategies designed to meet these investigative challenges include partial depolymerization using enzymatic or chemical reagents and spectroscopic examination of the intact polyesters in a solvent-swelled form . The soluble oligomers from degradative treatments of lime fruit cutin are composed primarily of the expected 10,16-dihydroxyhexadecanoic and 16-hydroxy-10-oxo-hexadecanoic acids; low-temperature HF treatments also reveal sugar units that are covalently attached to the hydroxyfatty acids . Parallel investigations of solvent-swollen cutin using 2D NMR spectroscopy assisted by magic-angle spinning yield well-resolved spectra that permit detailed comparisons to be made among chemical moieties present in the intact biopolymer, the soluble degradation products, and the unreacted solid residue.

Scand J Immunol, 2001 Jun, 53(6), 533 - 9
Regulation of IL-18 expression in virus infection; Pirhonen J; Since its discovery as an interferon (IFN)-gamma-inducing factor, it has become evident that interleukin (IL)-18 plays a crucial role in the generation of protective immunity against microbial infections . Macrophages are the major source of biologically active IL-18, and they express constitutively IL-18 mRNA and proIL-18 protein . Microbial infections enhance the IL-18 gene expression in macrophages but post-translational processing of proIL-18, rather than transcriptional activation, is predominant in the regulation of IL-18 secretion . This review summarizes the current knowledge of proinflammatory and immunomodulatory properties of IL-18, and focuses on the role of caspases in the proteolytic activation of IL-18 in response to virus infection.

J Clin Periodontol, 2001 Jul, 28(7), 634 - 41
A multifactorial investigation of the ability of oral health care products (OHCPs) to alleviate oral malodour; Silwood CJ et al.; AIM, BACKGROUND: Oral malodour (halitosis) is generally ascribable to oral microbial putrefaction generating malodorous volatile sulphur compounds which predominantly comprise dihydrogen sulphide and methyl mercaptan . This study assesses the relative effectiveness of 6 oral health care products in reducing oral cavity volatile sulphur compound concentrations . METHOD: A mixed model 3-factor factorial experimental design involving 6 volunteers, 7 treatment regimens (products I-VI* and water placebo) and 5 time-points (0.00-5.29 h) was undertaken . Electron-donating volatile sulphur compound levels were determined in triplicate using a sulphide monitor (Interscan model 1170) both prior to (0.00 h) and following oral rinsing (20 ml of 5 of the products) or chewing (2 capsules of the remaining product) episodes with each product examined (0.29, 1.29, 2.29 and 5.29 h post-administration) . RESULTS: Results were recorded as peak and steady-state volatile sulphur compound equivalents (ppb) . With the exception of one of the products, each oral health care product tested was found to reproducibly reduce volatile sulphur compound concentrations within 20 min of treatment; the mean % decreases in peak (and corresponding steady-state) levels ranging from 3.6 (0.0) to 16.8 (16.4)% . Subsequently, volatile sulphur compound concentrations returned to their zero-control (baseline) values within 5 h, the rate of this regression being in the reverse of the order observed for the magnitude of the primary 20 min reduction for both peak and steady-state measurements . As expected, the water placebo exerted no influence on oral cavity volatile sulphur compound levels . The most effective oral health care products contained admixtures of chlorite anion and chlorine dioxide (both of these agents have the ability to directly oxidise volatile sulphur compounds to non-malodorous products and the latter is also powerfully cidal towards odourigenic micro-organisms) . CONCLUSIONS: We therefore conclude that oral health care products containing such oxohalogen oxidants may provide a useful therapeutic strategy for the treatment of oral malodour.

Environ Microbiol, 2001 May, 3(5), 323 - 31
Phylogenetic analysis of ribosomal RNA operons from uncultivated coastal marine bacterioplankton; Suzuki MT et al.; Analyses of small subunit ribosomal RNA genes (SSU rDNAs) have significantly influenced our understanding of the composition of aquatic microbial assemblages . Unfortunately, SSU rDNA sequences often do not have sufficient resolving power to differentiate closely related species . To address this general problem for uncultivated bacterioplankton taxa, we analysed and compared sequences of polymerase chain reaction (PCR)-generated and bacterial artificial chromosome (BAC)-derived clones that contained most of the SSU rDNAs, the internal transcribed spacer (ITS) and the large subunit ribosomal RNA gene (LSU rDNA) . The phylogenetic representation in the rRNA operon PCR library was similar to that reported previously in coastal bacterioplankton SSU rDNA libraries . We observed good concordance between the phylogenetic relationships among coastal bacterioplankton inferred from SSU or LSU rDNA sequences . ITS sequences confirmed the close intragroup relationships among members of the SAR11, SAR116 and SAR86 clades that were predicted by SSU and LSU rDNA sequence analyses . We also found strong support for homologous recombination between the ITS regions of operons from the SAR11 clade.

Med Hypotheses, 2001 Jul, 57(1), 59 - 60
Iron loading: a risk factor for Whipple's disease?
Weinberg ED.
Because of impairment of microbial iron acquisition ability, some potential pathogens can cause disease only in iron loaded hosts . Tropheryma whippelii, the etiologic agent of Whipple's disease, is a possible example . Whipple's disease is non-contagious, occurs mainly in middle-aged white males, and displays many, but not all, of the complications of hereditary haemochromatosis . Tropheryma whippelii is a gastrointestinal commensal that causes disease in persons who have a Th1-Th2 imbalance . Host susceptibility may be exacerbated by iron loading . Consideration should be given to have patients evaluated for levels of interferon-gamma and interleukin-4 as well as for serum ferritin and transferrin iron saturation .

J Ind Microbiol Biotechnol, 2001 Mar, 26(3), 140 - 4
Metabolism of the veterinary fluoroquinolone sarafloxacin by the fungus Mucor ramannianus; Parshikov IA et al.; To investigate the microbial biotransformation of veterinary fluoroquinolones, Mucor ramannianus was grown in sucrose/peptone broth with sarafloxacin for 18 days . Cultures were extracted with ethyl acetate and extracts were analyzed by liquid chromatography . The two metabolites (26% and 15% of the A280, respectively) were identified by mass and 1H nuclear magnetic resonance spectra as N-acetylsarafloxacin and desethylene-N-acetylsarafloxacin . The biological formation of desethylene-N-acetylsarafloxacin has not been previously observed.

J Immunol, 2001 Jul 1, 167(1), 36 - 41
Structural features of nonpeptide prenyl pyrophosphates that determine their antigenicity for human gamma delta T cells; Morita CT et al.; Human Vgamma2Vdelta2(+) T cells proliferate in vivo during many microbial infections . We have found that Vgamma2Vdelta2(+) T cells recognize nonpeptide prenyl pyrophosphates and alkylamines . We now have defined structural features that determine the antigenicity of prenyl pyrophosphates by testing synthetic analogs for bioactivity . We find that the carbon chain closest to the pyrophosphate moiety plays the major role in determining bioactivity . Changes in this area, such as the loss of a double bond, abrogated bioactivity . The loss of a phosphate from the pyrophosphate moiety also decreased antigenicity 100- to 200-fold . However, nucleotide monophosphates could be added with minimal changes in bioactivity . Longer prenyl pyrophosphates also retained bioactivity . Despite differences in CDR3 sequence, Vgamma2Vdelta2(+) clones and a transfectant responded similarly . Ag docking into a Vgamma2Vdelta2 TCR model reveals a potential binding site in germline regions of the Vgamma2Jgamma1.2 CDR3 and Vdelta2 CDR2 loops . Thus, Vgamma2Vdelta2(+) T cells recognize a core carbon chain and pyrophosphate moiety . This recognition is relatively unaffected by additions at distal positions to the core Ag unit.

Gene, 2001 Jun 27, 271(2), 261 - 71
Cloning of a novel 2',5'-oligoadenylate synthetase-like molecule, Oasl5 in mice; Shibata S et al.; The 2',5'-oligoadenylate synthetase (2-5OAS) is a enzyme that catalyzes synthesis of 2',5'-oligoadenylates (2-5A) in a dsRNA-dependent manner, and known as a major component of the IFN-induced host defense mechanisms against microbial infections . Here, we report the presence of a novel 2-5OAS-like molecule, termed Oasl5, in mice . The size of Oasl5 cDNA was about 2 kb and encoded a protein consisting of 362 aa . The amino acid sequence showed 76% similarity to the mouse 2-5OAS, however, several motifs being important for the enzyme activity were not conserved . The Oasl5 mRNA was most significantly expressed in the brain, and relatively weak expression was found in other organs such as the spleen, kidney, ovary and testis . It was also expressed in embryonic stem (ES) cells . The Oasl5 mRNA expression in ES cells was elevated 5-fold after treatment with IFN and about 2-fold in the brain when stimulated with IFN inducer, polyinosinic-polycytidylic acid (poly{I:C}) . In situ hybridization analysis revealed that Oasl5 is expressed in neurons in the central nervous system in adult mice . When Oasl5 was expressed in E . coli, it yielded 42 kDa protein that binds to dsRNA, but it did not show oligoadenylate synthetase activity . These findings suggest a novel function of Oasl5, which are independent of oligoadenylate synthetase activity, in the brain and developing embryos.

Gene, 2001 Jun 27, 271(2), 233 - 8
Diptericin-like protein: an immune response gene regulated by the anti-bacterial gene induction pathway in Drosophila; Lee JH et al.; Insects produce various anti-microbial peptides in response to injury and infection . In Drosophila, diptericin has previously been studied as an anti-bacterial immune response gene . Here, we report the cloning of the diptericin-like protein (dptlp) gene as a paralog of Drosophila diptericin . By comparison of their sequences, we found that the dptlp gene has all of the functional domains conserved in the diptericin gene and other anti-bacterial proteins . The dptlp gene was rapidly induced by bacterial infections and showed different time-dependent gene expression patterns from those of diptericin . Like diptericin, dptlp was specifically produced from the fat body, and its expression was strictly dependent on bacterial infections . In addition, the dptlp gene expression was almost completely abolished in the imd mutant, which implicates that its expression is regulated by the anti-bacterial arm of the Drosophila innate immune regulatory pathways . In support of this, we found GATA, interferon consensus responding element, and kappa B binding sites, which is known to be important for the proper expression of anti-bacterial genes, in the proximal promoter region of the dptlp gene . Taken together, our findings support that dptlp is a novel anti-bacterial peptide whose expression is regulated by the anti-bacterial immune response mechanism.

J Dairy Sci, 2001 Jun, 84(6), 1294 - 309
Invited review: adhesion mechanisms of rumen cellulolytic bacteria; Miron J et al.; We divided the adhesion process of the predominant cellulolytic rumen bacteria Fibrobacter succinogenes, Ruminococcus flavefaciens, and Ruminococcus albus into four phases: 1) transport of the nonmotile bacteria to the substrate; 2) initial nonspecific adhesion of bacteria to unprotected sites of the substrate that is dominated by constitutive elements of bacterial glycocalyx; 3) specific adhesion via adhesins or ligands formation with the substrate, which can be dominated by several bacterial organelles including cellulosome complexes, fimbriae connections, glycosylated epitopes of cellulose-binding protein (CBP) or glycocalyx, and cellulose-binding domain (CBD) of enzymes; 4) proliferation of the attached bacteria on potentially digestible tissues of the substrate . Each of the phases and its significance in the adhesion process are described . Factors affecting bacterial adhesion are described including: 1) factors related to bacterial age, glycocalyx condition, and microbial competition; 2) factors related to the nature of substrate including, cuticle protection, surface area, hydration, and ionic charge; and 3) environmental factors including pH, temperature, and presence of cations and soluble carbohydrate . Based on the information available from the literature, it appears that each of the predominant rumen bacteria--F . succinogenes, R . flavefaciens, and R . albus--has a specific mechanism of adhesion to cellulose . In F . succinogenes, both the glycosidic residues of the outer membrane CBP and especially of the 180-kDa CBP, and the distinct CBD of EG2 EGF and Cl-stimulated cellobiosidase, may play a role in the adhesion to cellulose . No direct evidence, except scanning electron microscopy observations, yet supports the existence of either cellulosome complex or fimbriae structures involved in the adhesion mechanism of F . succinogenes . At least two mechanisms, cellulosome-like complexes and carbohydrate epitopes of the glycocalyx layer are involved in the specific adhesion of R . flavefaciens to cellulose . Ruminococcus albus possesses at least two mechanisms for specific adhesion to cellulose: a cellulosomal-like mechanism, and a CbpC (Pil)-protein mechanism that probably involves the production of fimbrial-like structures . Indirect and direct studies suggested that carbohydrate epitopes of CBPs and CBD epitope of cellulases may also be involved mostly in the nonspecific phase of adhesion of R . albus.

J AOAC Int, 2001 May-Jun, 84(3), 629 - 33
Determination of phytase activity in feed by a colorimetric enzymatic method: collaborative interlaboratory study; Engelen AJ et al.; Fourteen laboratories participated in a collaborative study (coded fyt9404) and 13 laboratories participated in a study (coded fyt9410) to validate a colorimetric assay for determination of microbial phytase activity in feed . For each study, all laboratories received 6 laboratory samples provided by one commercial supplier (phytase activity levels within the range of 200-400 per kg) to be analyzed in duplicate . Method performance was calculated and statistical calculations were executed according to AOAC guidelines . Results from 3 laboratories for study fyt9404 and from one laboratory for study fyt9410 were excluded from statistical analysis because of invalid data determined during initial review by Youden pair, value versus laboratory . For study fyt9404, repeatability relative standard deviation (RSDr) values ranged from 6.2 to 8.6%, and reproducibility relative standard deviation (RSDR) values ranged from 14.1 to 27.6% . No outliers were identified . For study fyt9410, RSDr values ranged from 3.9 to 7.9%, and RSDR values ranged from 14.0 to 20.5% . With outliers excluded, RSDr values ranged from 2.5 to 7.9%, and RSDR values ranged from 14.0 to 20.5%.

Risk Anal, 2001 Apr, 21(2), 319 - 30
Perceived risks of conventional and organic produce: pesticides, pathogens, and natural toxins; Williams PR et al.; Public risk perceptions and demand for safer food are important factors shaping agricultural production practices in the United States . Despite documented food safety concerns, little attempt has been made to elicit consumers' subjective risk judgments for a range of food safety hazards or to identify factors most predictive of perceived food safety risks . In this study, over 700 conventional and organic fresh produce buyers in the Boston area were surveyed for their perceived food safety risks . Survey results showed that consumers perceived relatively high risks associated with the consumption and production of conventionally grown produce compared with other public health hazards . For example, conventional and organic food buyers estimated the median annual fatality rate due to pesticide residues on conventionally grown food to be about 50 per million and 200 per million, respectively, which is similar in magnitude to the annual mortality risk from motor vehicle accidents in the United States . Over 90% of survey respondents also perceived a reduction in pesticide residue risk associated with substituting organically grown produce for conventionally grown produce, and nearly 50% perceived a risk reduction due to natural toxins and microbial pathogens . Multiple regression analyses indicate that only a few factors are consistently predictive of higher risk perceptions, including feelings of distrust toward regulatory agencies and the safety of the food supply . A variety of factors were found to be significant predictors of specific categories of food hazards, suggesting that consumers may view food safety risks as dissimilar from one another . Based on study findings, it is recommended that future agricultural policies and risk communication efforts utilize a comparative risk approach that targets a range of food safety hazards.

Immunol Rev, 2001 Apr, 180, 65 - 77
gC1q-R/p33, a member of a new class of multifunctional and multicompartmental cellular proteins, is involved in inflammation and infection; Ghebrehiwet B et al.; Human gC1q-R (p33, p32, C1qBP, TAP) is a ubiquitously expressed, multiligand-binding, multicompartmental cellular protein involved in various ligand-mediated cellular responses . Although expressed on the surface of cells, an intriguing feature of the membrane-associated form of gC1q-R is that its translated amino acid sequence does not predict the presence of either a sequence motif compatible with a transmembrane segment or a consensus site for a glycosylphosphatidylinositol anchor . Moreover, the N-terminal sequence of the pre-pro-protein gC1q-R contains a motif that targets the molecule to the mitochondria and as such was deemed unlikely to be expressed on the surface . However, several lines of experimental evidence clearly show that gC1q-R is present in all compartments of the cell, including the extracellular cell surface . First, surface labeling of B lymphocytes with the membrane-impermeable reagent sulfosuccinimidyl 6-(biotinamido)hexanoate shows specific biotin incorporation into the surface-expressed but not the intracellular form of gC1q-R . Second, FACS and confocal laser scanning microscopic analyses using anti-gC1q-R IgG mAb 60.11 or 74.5.2, and the fluorophore Alexa 488-conjugated F(ab')2 goat anti-mouse IgG as a probe, demonstrated specific staining of Raji cells (>95% viable) . Three-dimensional analyses of the same cells by confocal microscopy showed staining distribution that was consistent with surface expression . Third, endothelial gC1q-R, which is associated with the urokinase plasminogen activator receptor, and cytokeratin 1 bind 125I-high molecular weight kininogen in a specific manner, and the binding is inhibited dose-dependently by mAb 74.5.2 recognizing gC1q-R residues 204-218 . Fourth, native gC1q-R purified from Raji cell membranes but not intracellular gC1q-R is glycosylated, as evidenced by a positive periodic acid Schiff stain as well as sensitivity to digestion with endoglycosidase H and F . Finally, cross-linking experiments using C1q as a ligand indicate that both cC1q-R and gC1q-R are co-immunoprecipitated with anti-C1q . Taken together, the evidence accumulated to date supports the concept that in addition to its intracellular localization, gC1q-R is expressed on the cell surface and can serve as a binding site for plasma and microbial proteins, but also challenges the existing paradigm that mitochondrial proteins never leave their designated compartment . It is therefore proposed that gC1q-R belongs to a growing list of a class of proteins initially targeted to the mitochondria but then exported to different compartments of the cell through specific mechanisms which have yet to be identified . The designation 'multifunctional and multicompartmental cellular proteins' is proposed for this class of proteins.

Dan Med Bull, 2001 May, 48(2), 84 - 8
Penicillin as empirical therapy for patients hospitalised with community acquired pneumonia at a Danish hospital; Kirk O et al.; INTRODUCTION: We report on the outcome of a study of patients hospitalised with community acquired pneumonia (HCAP) at a Danish university hospital . METHODOLOGY: In a retrospective study of 243 consecutive patients with radiographically verified HCAP, data on clinical and laboratory findings and outcome parameters were collected . Three groups were established according to the initial choice of antibiotic(s): penicillin only (n = 160); non-allergic patients starting broader spectrum therapy (n = 54); and patients with suspected penicillin allergy (n = 29) . RESULTS: The overall mortality within three months was 12% and the readmission rate within three months was 20% . The three treatment groups were comparable with respect to most demographic and clinical criteria at baseline . No significant differences in outcome between the groups were found: the mortality was 12.5%, 13.0%, and 10.3%, respectively, p = 0.94, and the readmission rate 20.3%, 24.0%, and 14.8%, respectively; p = 0.63 . CONCLUSION: Patients treated for community-acquired pneumonia at a Danish university hospital had clinical outcomes fully at height with findings from other countries, and half of the patients were successfully treated with penicillin monotherapy . No differences in clinical outcomes were documented between patients treated empirically with broad-spectrum therapy and penicillin monotherapy . Therefore, penicillin seems to be a reasonable first choice for initial therapy of HCAP in Denmark as in other regions with similar patterns of microbial pathogens and resistance.

J Microbiol Methods, 2001 Jul 30, 46(1), 51 - 62
Bacteria in gel probes: comparison of the activity of immobilized sulfate-reducing bacteria with in situ sulfate reduction in a wetland sediment; Edenborn HM et al.; A novel method was used to examine the microbial ecology of iron-rich wetland sediments receiving neutral-pH coal mine drainage . Gel probes inserted into the sediments allowed analysis of the distribution and activity of bacterial sulfate reduction (BSR) . A mixed population of sulfate-reducing bacteria enriched from anoxic wetland sediments was immobilized in low temperature-gelling agarose held in grooved rods or probes . The probes were inserted vertically into sediments and were allowed to incubate in situ for 48 h . After their retrieval, the gels were sectioned and analyzed for residual BSR activity and were compared to in situ BSR rates and chemical porewater profiles . The depth distribution of residual BSR activity in the immobilized cell gel probes differed significantly from the BSR measured in situ . Approximately 51% of the total integrated residual sulfate reduction activity measured in the gel probes occurred between 0 and 7 cm of the upper 20 cm of sediment . In contrast, ca . 99% of the integrated in situ BSR occurred between 7- and 20-cm depth, and only 1% of the total integrated rate occurred between 0- and 7-cm depth . Lactate-enriched bacteria immobilized in the gel may have been atypical of the majority of sulfate-reducing bacteria in the sediment . Agarose-immobilized sulfate-reducing bacteria might also be able to proliferate in the otherwise inhospitable zone of iron reduction, where sulfate and labile carbon compounds for which they are usually outcompeted can diffuse freely into the gel matrix . Gel probes containing particulate iron monosulfide (FeS) indicated that FeS remained stable in sediments at depths greater than 2 to 3 cm below the sediment-water interface, consistent with the shallow penetration of oxygen into surface sediments.

J Microbiol Methods, 2001 Jul 30, 46(1), 37 - 49
Microbial community assessment in oil-impacted salt marsh sediment microcosms by traditional and nucleic acid-based indices; Bachoon DS et al.; The effect of oil amendment in salt marsh sediment microcosms was examined by most probable number (MPN), DNA-hybridization with domain-specific oligonucleotide probes and whole community 16S rDNA-hybridizations . Gas chromatography (GC/MS) analysis of oil residues in sediments from microcosms after 3 months of operation showed that the quantity of petroleum hydrocarbons was lower in microcosms amended with oil compared to microcosms amended with oil+plant detritus . Bacterial numbers (total-MPN) increased in all experimental microcosms (amended with plant detritus, oil, and oil+plant detritus) . In comparison to the intact sediment, the proportions of oil-degrading bacteria increased >100-fold in the oil amended microcosm and >10-fold in the plant detritus and the oil+plant detritus amended microcosms . DNA-hybridizations with Bacteria, Archaea and Eukarya oligonucleotide probes indicated few changes in the petroleum contaminated sediment community profile . In contrast, rDNA-hybridizations indicated that the bacterial community profile of the oil-impacted sediments, after 1 month of exposure, was significantly different from the control sediment.

FEBS Lett, 2001 Jun 8, 498(2-3), 219 - 22
Antibiotic activities of peptides, hydrogen peroxide and peroxynitrite in plant defence; Garcia-Olmedo F et al.; Genes encoding plant antibiotic peptides show expression patterns that are consistent with a defence role . Transgenic over-expression of defence peptide genes is potentially useful to engineer resistance of plants to relevant pathogens . Pathogen mutants that are sensitive to plant peptides in vitro have been obtained and a decrease of their virulence in planta has been observed, which is consistent with their hypothetical defence role . A similar approach has been followed to elucidate the potential direct anti-microbial role of hydrogen peroxide . Additionally, a scavenger of peroxynitrite has been used to investigate its involvement in plant defence.

Lett Appl Microbiol, 2001 Jun, 32(6), 384 - 7
Use of temporal temperature gradient gel electrophoresis to identify flaA and fim3 sequence types in Bordetella bronchiseptica; Shina A et al.; AIMS: The aim of this study was to develop an approach to detect variation in the flaA and fim3 genes amongst animal isolates of Bordetella bronchiseptica using temporal temperature gradient gel electrophoresis (TTGE) . METHODS AND RESULTS: Amplicons representing three flaA and two fim3 sequence types were subjected to TTGE analysis . It was possible to distinguish clearly between each of the sequence types using TTGE . CONCLUSION: This suggests that TTGE could be a useful tool for studying the epidemiology of B . bronchiseptica . Significance and Impact of the Study: PCR amplification coupled to TTGE offers a general method for the rapid screening of large numbers of microbial strains for variations in gene sequences.

J Immunol Methods, 2001 Aug 1, 254(1-2), 109 - 18
Simultaneous measurement of six cytokines in a single sample of human tears using microparticle-based flow cytometry: allergics vs . non-allergics; Cook EB et al.; Tears play an essential role in maintaining corneal and conjunctival integrity by providing a tightly regulated, optimal extracellular environment critical to its numerous functions, which include anti-microbial defense, wound healing and inflammatory responses such as allergies . Elevated levels of inflammatory cytokines have been reported in tears from various ocular disease states . Characterization of tear cytokines has been limited by the small volume (microliter amounts) attainable . This limitation was addressed with the newly developed Becton Dickinson Cytometric Bead Array (CBA), which combines the principles of the "sandwich" immunoassay with the capability of flow cytometry for simultaneous measurement of the characteristics of multiple particles . This technique allows determination of six human cytokine (IFNgamma, TNFalpha, IL-2, IL-4, IL-5, IL-10) concentrations simultaneously in a single tear sample . Tears were collected from the inferior fornix of non-allergic (n=7) and allergic (n=9) donors . Each tear sample or cytokine standard was incubated with a mixture of capture Ab-bead reagent and detector Ab-phycoerythrin (PE) reagent, and analyzed using flow cytometry . All six cytokines were detectable in both non-allergic and allergic tears . Tears from allergic donors contained significantly less IL-10 (p=0.035), and had significant increases in the ratios of TNFalpha/IFNgamma, IL-5/IFNgamma and IL-5/IL-10 (p=0.0008, 0.0124 and 0.011, respectively) . The small volume required (5-10 microl/test) by the Cytometric Bead Array allows measurement of all six cytokines from a single collection of tears . This decreases collection time, minimizing the confounding effect of stimulation on cytokine concentration in tears, as well as allowing calculation of cytokine ratios.

Curr Opin Biotechnol, 2001 Jun, 12(3), 254 - 8
Microbial dehalogenation; Janssen DB et al.; Novel dehalogenases have been identified recently in various bacteria that utilise halogenated substrates . X-ray studies and sequence analysis have revealed insight into the molecular mechanisms of hydrolytic dehalogenases . Furthermore, genetic and biochemical studies have indicated that reductive dehalogenases are extra-cytoplasmic corrinoid-containing iron-sulphur proteins . Sequence analysis and mutagenesis studies indicate that several dehalogenases are homologous to enzymes that carry out transformations on non-halogenated substrates.

Adv Microb Physiol, 2001, 44, 183 - 213
Microbial metallothioneins; Robinson NJ et al.; Bacterial metallothioneins bind, sequester and buffer excess intracellular zinc . At present, the vast majority of the available experimental data relate to cyanobacterial metallothionein, SmtA, from Synechococcus PCC 7942 . SmtA is required for normal resistance to zinc and smtA-mediated zinc resistance has been used as a selectable marker . The imidazole groups of histidine residues, in addition to the thiol groups of cysteine residues, co-ordinate zinc in bacterial metallothioneins . The structure of bacterial metallothionein must facilitate some discrimination between 'adventitious' and 'adventageous' zinc-binding sites such that under excess zinc conditions metal is predominantly scavenged from the former . It remains unclear whether or not bacterial metallothionein also acts as a zinc store that supplies zinc-requiring proteins or if under some conditions it deactivates a subset of proteins via zinc removal . Expression of smtA is induced in response to elevated concentrations of zinc via the action of SmtB . SmtB has some sequence similarity to the arsenic responsive repressor ArsR and genes encoding related proteins are present in many bacterial genomes . Metal perception by SmtB differs from ArsR . The latter contains a characteristic Cys-Val-Cys motif associated with a DNA-binding helix-turn-helix (the ArsR motif), while the former contains metal-binding motifs associated with a carboxyl-terminal alpha-helix that forms the interface between SmtB dimers (the SmtB motif) . Some SmtB-ArsR family proteins, including the zinc sensor ZiaR from the cyanobacterium Synechocystis PCC 6803, have the metal-sensory motifs of both SmtB and ArsR . The mechanisms of action, and the features that allow discrimination between different metal ions by these sensors, are discussed.

Curr Microbiol, 2001 May, 42(5), 339 - 44
Fluorescein diacetate hydrolysis as a measure of fungal biomass in soil; Gaspar ML et al.; The fatty acid methyl esters of lipids extracted from an agricultural soil in the preharvest period of soybean or middle growth cycle from wheat were characterized and quantified by gas-liquid chromatography . The fatty acids 18:2omega6 and 16:1omega5 were used as markers of saprotrophic and arbuscular mycorrhizal fungi . In parallel, biomass estimation through plate counts in selective media for cellulolytic and saprotrophic fungi was also performed all throughout a soybean crop or middle growth cycle of wheat . As an enzymatic method, the fluorescein diacetate (FDA) hydrolytic activity of the samples was determined . Owing to the high relationship exhibited by FDA hydrolysis with organic carbon and total nitrogen content of soil, the enzymatic activity was correlated with the microbial biomass estimated through marker lipids or plate counts . The results obtained point out that FDA hydrolysis may be used as a rapid, cheap, and reliable estimator of fungal biomass.

Biochemistry (Mosc), 2001 Apr, 66(4), 369 - 77
Characterization of the lipopolysaccharide and structure of the O-specific polysaccharide of the bacterium Pseudomonas syringae pv . atrofaciens IMV 948; Zdorovenko GM et al.; Lipopolysaccharide (LPS) was isolated from the phytopathogenic bacterium Pseudomonas syringae pv . atrofaciens IMV 948 by mild extraction of the microbial cells with saline, and the properties, composition, and structure of the LPS were studied . The LPS showed low toxicity in D- galactosamine-sensitized mice and low biological activity in plants . Structural components of LPS--lipid A, core oligosaccharide, and O-specific polysaccharide (OPS)--were obtained by mild acid degradation and characterized . The lipid A contained fatty acids 3-HO-C10:0, C12:0, 2-HO-C12:0, 3-HO-C12:0, C16:0, C16:1, C18:0, and C18:1, as well as components of the hydrophilic moiety: GlcN, ethanolamine, phosphate, and phosphoethanolamine . The LPS core contained components typical of pseudomonads: glucose, rhamnose (Rha), L-glycero-D-manno-heptose, GlcN, GalN, 2-keto-3-deoxy-D-manno-octonic acid, alanine, and phosphate . The OPS consisted of L-Rha and D-GlcNAc in the ratio 4 : 1 and was structurally heterogeneous . The main pentasaccharide repeating unit of the OPS has the following structure: {structure see text} . Immunochemical studies showed that P . syringae pv . atrofaciens IMV 948 is serologically separate from other P . syringae strains, including those that have structurally similar OPS.

J Theor Biol, 2001 Jun 21, 210(4), 425 - 34
Adaptive value of polymorphism in intracellular self/not-self discrimination?
Forsdyke DR.
A microbial pathogen species can adapt to its host species to the extent that members of the host species are uniform . Loss of this uniformity would make it difficult for a pathogen species to transfer, from one member of the host species to another, what it had "learned" through selection of its members with advantageous mutations . The existence of major histocompatibility complex (MHC) polymorphism indicates that non-uniformity within a species is an effective host defence strategy . By virtue of this molecular discontinuity among its members the host species can "present a moving target" to the pathogen . Many proteins other than MHC proteins show polymorphism - a phenomenon which has suggested that mutations in regions of protein molecules which do not affect overt function are neutral . However, in the context of the author's differential aggregation theory of intracellular self/not-self discrimination as previously applied to the problem of the antigenicity of cancer cells, such polymorphism should serve for the recruitment of subsets of self-antigens into the antigenic repertoire of an infected cell . These would act as "intracellular antibodies" by virtue of their weak, but specific, aggregation with pathogen proteins . Peptides from the self-antigens, as well as (or instead of) those from the antigens of the pathogen, would then serve as targets for attack by cytotoxic T cells . Thus, polymorphism of intracellular proteins should be of adaptive value, serving to amplify and individualize the immune response to intracellular pathogens .

Best Pract Res Clin Gastroenterol, 2001 Jun, 15(3), 413 - 31
Current role of acid suppressants in Helicobacter pylori eradication therapy; Labenz J; Helicobacter pylori induces chronic active gastritis that may progress to atrophy . Serious clinical consequences are peptic ulcer disease and gastric malignancies . Today, treatment of the infection is an appropriate option and is strongly recommended in various clinical situations . Although many antibiotics are effective against H . pylori in vitro, few substances are suitable for use in vivo . This is because H . pylori lives in a unique environment in which several factors may affect the pharmacokinetic and pharmacodynamic properties of the anti-microbial agents . One of the most important factors is gastric acidity . This article reviews the effects of acid suppression on H . pylori and the associated gastritis, the potential mechanisms by which anti-secretory drugs such as proton pump inhibitors might enhance the activity of anti-microbials in vivo, and the results of clinical trials supporting the current view that proton pump inhibitors are a mainstay in the treatment of this infection.

J Chromatogr A, 2001 May 11, 917(1-2), 167 - 77
Development and application of a high resolution liquid chromatographic method for the analysis of complex pigment distributions; Airs RL et al.; Ternary and binary gradient systems have been developed for the high-performance liquid chromatographic analysis of complex pigment distributions typical of natural samples . Improved chromatographic resolution reveals significantly more pigment components in extracts from a sediment (Priest Pot, Cumbria, UK), a microbial mat (les Salines de la Trinital, South Catalonia, Spain) and a culture (C . phaeobacteroides) including novel bacteriochlorophyll derivatives . The methods developed are directly suited to LC-MS analysis and the automated acquisition of MS/MS data for pigments.

J Food Prot, 2001 Jun, 64(6), 826 - 32
Traditional versus hazard analysis and critical control point-based inspection: results from a poultry slaughter project; Cates SC et al.; Federal meat and poultry inspection has changed little since the Federal Meat Inspection Act was passed in 1906, followed by the Poultry Products Inspection Act of 1957 and related amendments . These acts mandate sensory or organoleptic (sight, smell, and touch) inspection of all carcasses . For several decades, the U.S . Department of Agriculture's Food Safety and Inspection Service (FSIS) has been urged by various organizations to move to a scientific, risk-based inspection system . In partial response to these calls, the FSIS has developed new slaughter inspection models that are currently being tested with volunteer plants in the hazard analysis and critical control point (HACCP)-based inspection models project . To evaluate whether plants operating under the new inspection models perform at least as well as they did under the current or traditional system, microbial and organoleptic data are being collected before and after the implementation of the new inspection models . In this article, we describe the baseline and models data collection procedures and present the results of the baseline and models data collection for eight plants that slaughter young chickens . The results from the first eight volunteer plants suggest that inspection under the new models is equivalent and in some ways superior to that of traditional inspection . This pilot project suggests that new slaughter inspection systems, which rely on HACCP principles with FSIS oversight and verification services, can maintain or even improve food safety and other consumer protection conditions relative to traditional hands-on inspection methods.

Arch Virol, 2001, 146(4), 767 - 75
Replication of Chilo iridescent virus in the cotton boll weevil, Anthonomus grandis, and development of an infectivity assay; Henderson CW et al.; The boll weevil, Anthonomus grandis Boheman, is a devastating pest of cotton . Chemical pesticides are problematic due to relative lack of target specificity and resistance . Microbial pesticides may provide viable alternatives because of their narrow host range . Chilo iridescent virus (CIV) is the type species for genus Iridovirus, family Iridoviridae: large, icosahedral cytoplasmic viruses containing a double-stranded DNA genome . Earlier work suggested that CIV replicated in the boll weevil; however, efficiency or production of infectious virus was not established . We showed that CIV undergoes a productive cycle in A . grandis . CIV DNA levels in boll weevil pupae increased significantly from 0 to 3 days post infection . Moreover, virogenic stromata and complete virus particles were observed in the cytoplasm by 7 days . An endpoint dilution assay using viral DNA replication as indicator suggested a 10(5)-fold increase in infectious virus titer over 7 days . This is the first such demonstration in larval infections with genus Iridovirus . Our study establishes that CIV undergoes a productive cycle in the boll weevil and provides an important and useful model system for replication at the organismal level . These results have important implications for the potential of CIV and its components in boll weevil control.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2001 Jun, 91(6), 654 - 8
Anxiety and pain suppress the natural killer cell activity in oral surgery outpatients; Koga C et al.; OBJECTIVE: Psychological stress has an influence on natural killer cell (NK) activity, which plays a central role in protection against microbial infection and cancer . Anxiety concerning cancer is a typical type of psychological stress observed in patients and is associated with various diseases . In this study, we examined whether anxiety about cancer reduces the NK activity or quality of life (QOL), or both, of outpatients . PATIENTS AND METHODS: NK activity was determined by means of a 4-hour 51 chromium-release assay, and a QOL questionnaire by the World Health Organization called QOL-BRIEF was also used . One hundred forty-four patients were asked a variety of questions about anxiety with respect to cancer and pain on their first visit to the outpatient clinic of our Department of Oral Surgery . RESULTS: The NK activity in patients with anxiety about cancer was significantly lower (P < .001) than that in those with no such anxiety . In contrast, NK activity was not influenced by any other factor tested, including differences in diseases and QOL scores . CONCLUSION: Anxiety about cancer may be one of the primary factors for suppression of NK activity in oral surgery outpatients.

Plant Cell, 2001 Jun, 13(6), 1467 - 75
Directed proteomics identifies a plant-specific protein rapidly phosphorylated in response to bacterial and fungal elicitors; Peck SC et al.; The perception of microbial signal molecules is part of the strategy evolved by plants to survive attacks by potential pathogens . To gain a more complete understanding of the early signaling events involved in these responses, we used radioactive orthophosphate to pulse-label suspension-cultured cells of Arabidopsis in conjunction with two-dimensional gel electrophoresis and mass spectrometry to identify proteins that are phosphorylated rapidly in response to bacterial and fungal elicitors . One of these proteins, AtPhos43, and related proteins in tomato and rice, are phosphorylated within minutes after treatment with flagellin or chitin fragments . By measuring (32)P incorporation into AtPhos43 immunoprecipitated from extracts of elicitor-treated hormone and defense-response mutants, we found that phosphorylation of AtPhos43 after flagellin treatment but not chitin treatment is dependent on FLS2, a receptor-like kinase involved in flagellin perception . Induction by both elicitors is not dependent on salicylic acid or EDS1, a putative lipase involved in defense signaling.

Eur Respir J, 2001 Apr, 17(4), 791 - 801
Microbial investigation in ventilator-associated pneumonia; Ioanas M et al.; Ventilator-associated pneumonia (VAP) is a serious infectious condition in intensive care unit (ICU) patients, currently related to a high mortality rate . Therefore, this complication of mechanical ventilation requires a prompt diagnosis and adequate antibiotic treatment . The detection of the causative organism is imperative for guiding an appropriate therapy as there is strong evidence of the adverse effect of inadequate empirical treatment on outcome . The major difficulty of the microbial investigation is to obtain the sample from the lower respiratory tract, mainly because of the potential contamination with upper airways flora, which may result in a misinterpretation of the cultures . Microbial investigation in VAP is based on the culture of samples obtained from lower respiratory tract by noninvasive or invasive methods . The most common techniques of sampling are the endotracheal aspirate (ETA), which is considered a noninvasive method, the protected specimen brush (PSB) and the bronchoalveolar lavage (BAL), both being invasive methods of investigation . The latter were designed as an attempt to avoid the colonizing flora of the upper airways . The best of these diagnostic approaches is still controversial . In terms of outcome, there is strong evidence that the impact of both invasive and noninvasive methods seems to be similar . In terms of cost, however, the endotracheal aspirate is less expensive compared to BAL or PSB . On the other hand, invasive methods could be particularly beneficial in patients who are not responding to the initial empirical antibiotic treatment . The rationale for the quantitative culture of the respiratory samples is to differentiate between infection and colonization of lower airways, because the bacterial colonization is a frequent event in mechanically ventilated patients . The thresholds currently employed for the diagnosis of the pneumonia are the following: ETA samples, > or = 10(5)-10(6) colony forming units (cfu).mL(-1); PSB samples, > or =10(3) cfu.mL(-1); and BAL samples, > or =10(4) cfu.mL(-1) . Intending to provide a practical approach to the issue, the present manuscript reviews the available noninvasive (blood culture, endotracheal aspirate) and invasive (protected specimen brush, bronchoalveolar lavage, blinded methods and lung biopsy) techniques used for the diagnosis of ventilator-associated pneumonia.

Med Hypotheses, 2001 Jun, 56(6), 731 - 4
Iron, infection and sudden infant death; Weinberg ED; Three risk factors for sudden infant death syndrome are well established: maternal smoking, prone sleeping position and non-breast feeding . Two additional risk factors have been proposed: microbial infection in the gastrointestinal or respiratory tracts and iron loading . This review endeavors to integrate these five disparate factors into a unifying concept.

Carbohydr Res, 2001 Apr 23, 331(4), 423 - 30
Synthesis of branched cyclomaltooligosaccharide carboxylic acids (cyclodextrin carboxylic acids) by microbial oxidation; Ishiguro T et al.; Novel branched cyclomaltooligosaccharide carboxylic acid (cyclodextrin carboxylic acid) derivatives were synthesized by microbial oxidation using Pseudogluconobacter saccharoketogenes to oxidize five types of branched cyclodextrins, including maltosyl beta-cyclodextrin (maltosyl-beta-CyD) . For each novel cyclodextrin carboxylic acid derivative synthesized, the hydroxymethyl group of the terminal glucose residue in the branched part of the molecule was regiospecifically oxidized to a carboxyl group to give the corresponding uronic acid . In addition, the physicochemical properties of cyclomaltoheptaosyl-(6-->1)-alpha-D-glucopyranosyl-(4-->1)-alpha-D-glucopyranosiduronic acid (GUG-beta-CyD) (1) and its sodium salt were studied more extensively, as these compounds are most likely to have a practical application.

Appl Microbiol Biotechnol, 2001 May, 55(4), 395 - 403
Microbial metabolites as eco-friendly agrochemicals for the next millennium; Saxena S et al.; As a result of the increasing environmental and health-related problems caused by the synthetic agrochemicals currently used, suitable and non-hazardous innovative alternatives are being sought . Antagonism and allelopathy, both in nature and in agro-ecosystems, have attracted these researchers' attention, with the main goal of using these phenomena in the biological control of weeds . This article presents a review on the use and efficacy of microbial secondary metabolites which have potential as natural herbicides, either directly or as templates for bio-rational eco-friendly agrochemicals (allelochemicals) . Their merits as alternatives to synthetic chemicals and biological control agents have been highlighted for an holistic approach in integrated pest/weed management.

Bioresour Technol, 2001 Aug, 79(1), 29 - 33
Microbial decomposition of post-harvest sugarcane residue; Boopathy R et al.; A laboratory in situ composting study was conducted as a possible alternative method for the current practice of open air burning of post-harvest sugarcane residue by sugarcane farmers . In situ composting of the sugarcane residue by the indigenous bacteria and fungi was accelerated using molasses as an initial substrate . A one-time application of molasses boosted the soil microbial population . which started to decompose the ligno-cellulosic fractions of the residue . The study showed significant differences in several parameters among the control and molasses applied treatments, namely, visual decomposition of residue, bacterial and fungal population, soil pH, cellulose content, cellulase activity . and soil organic matter . Further study is needed to refine the process for the future application of this technology as a possible alternative to the current practice of open air burning of sugarcane residue by farmers.

J Am Vet Med Assoc, 2001 Jun 1, 218(11), 1800 - 2, 1779
Scedosporium prolificans infection associated with arthritis and osteomyelitis in a horse; Swerczek TW et al.; Scedosporium prolificans was associated with arthritis and degenerative osteomyelitis in a 6-year-old Thoroughbred racehorse . The horse was suspected to have an inflammatory lesion of the interosseous tendon, but treatment had resulted in only a minimal response . Shortly after diagnostic arthrocentesis of the left metacarpophalangeal joint was performed, the joint became severely swollen, and radiography of the area revealed lysis of the distal end of the third metacarpal bone, the proximal sesamoid bones, and the proximal end of the proximal phalanx . The horse did not respond to treatment and was euthanatized . At necropsy, severe erosive arthritis and degenerative osteomyelitis of the left metacarpophalangeal joint were seen . Swab specimens of the ulcerated lesions of the articular cartilage were submitted for microbial culture, and Scedosporium prolificans was isolated . Scedosporium prolificans is a newly recognized opportunistic fungal pathogen of humans and animals . In humans, S prolificans typically causes focal locally invasive infections that primarily involve musculoskeletal tissues; most often, infection is a result of penetrating trauma or surgical incision . In immunocompromised patients, fatal disseminated infection can occur . The fungus is resistant to almost all currently available antimycotic agents.

Phytochemistry, 2001 Jun, 57(3), 385 - 91
Blend effects in the toxicity of the essential oil constituents of Ocimum kilimandscharicum and Ocimum kenyense (Labiateae) on two post-harvest insect pests; Bekele J et al.; The lethal toxicity of major components of the essential oils of Ocimium kilimandscharicum and O . kenyense and of selected blends of these against Sitophilus zeamais and Rhyzopertha dominica were compared with those of the full blends of the essential oils . The compounds were assayed in amounts and proportions present in the minimum 100% lethal dose of the oils . Whereas a major component of O . kilimandscharicum was found to be largely responsible for the toxic action of its essential oil against R . dominica, the results with the other treatments indicated that the toxic action of the essential oils were due to the combined effects of different components, either with or without significant individual toxic action of their own against the insects . The significance of the results and their implication in screening and using plants and their phytochemicals for pest and microbial control are highlighted.

Am J Clin Nutr, 2001 Jun, 73(6), 1147S - 1151S
Clinical applications of probiotic agents; Saavedra JM; In the past century the beneficial roles of nonpathogenic bacteria in the intestinal lumen were described . In the past decade there has been a dramatic increase in scientific work supporting the concept that there are clinical benefits to ingesting specific nonpathogenic organisms (probiotics) . The potential benefits of modifying the intestinal flora composition of certain high-risk groups, eg, premature infants, travelers, and children receiving antibiotics, are emerging in the literature . Studies documenting prophylactic and therapeutic benefits in acute viral gastroenteritis and in atopic disease point not only to the potential applications, but also to the fact that the mechanisms of action of these agents may be due to their interaction with the gut as an immunologic organ . The benefits documented thus far are of varying degree and are most likely dependent on the number of agents, the dose, the dosing patterns, and the characteristics of the host and its underlying luminal microbial environment . Consequently, the safety and specification of a particular probiotic agent and methods of delivery to a particular population for a particular purpose should be carefully documented before making broad recommendations . The cost-benefit assessment of adding probiotics to our diet for prophylactic or therapeutic purposes, as well as better regulation of these agents as commercial products, is also needed.

Exp Biol Med (Maywood), 2001 May, 226(5), 353 - 66
The immune response to ocular herpes simplex virus type 1 infection; Carr DJ et al.; Herpes simplex virus type 1 (HSV-1) is a prevalent microbial pathogen infecting 60% to 90% of the adult world population . The co-evolution of the virus with humans is due, in part, to adaptations that the virus has evolved to aid it in escaping immune surveillance, including the establishment of a latent infection in its human host . A latent infection allows the virus to remain in the host without inducing tissue pathology or eliciting an immune response . During the acute infection or reactivation of latent virus, the immune response is significant, which can ultimately result in corneal blindness or fatal sporadic encephalitis . In fact, HSV-1 is one of the leading causes of infectious corneal blindness in the world as a result of chronic episodes of viral reactivation leading to stromal keratitis and scarring . Significant inroads have been made in identifying key immune mediators that control ocular HSV-1 infection and potentially viral reactivation . Likewise, viral mechanisms associated with immune evasion have also been identified and will be discussed . Lastly, novel therapeutic strategies that are currently under development show promise and will be included in this review . Most investigators have taken full advantage of the murine host as a viable working in vivo model of HSV-1 due to the sensitivity and susceptibility to viral infection, ease of manipulation, and a multitude of developed probes to study changes at the cellular and molecular levels . Therefore, comments in this review will primarily be restricted to those observations pertaining to the mouse model and the assumption (however great) that similar events occur in the human condition.

Microb Ecol, 2001 Apr, 41(3), 210 - 221
Microbial Competition in Reactors with Wall Attachment; Ballyk MM et al.; Competition for nutrient and the ability of bacteria to colonize the gut wall are factors believed to play a role in the observed stability of the indigenous microbiota of the mammalian large intestine . These factors were incorporated into the two-strain continuous-stirred tank reactor (CSTR) model formulated and numerically investigated by Freter et al . In their model simulations, the reactor is parameterized using data for the mouse intestine . An invading bacterial strain is introduced into a CSTR that has already been colonized by a resident strain . The two strains compete for a single growth-limiting nutrient and for limited adhesion sites on the wall of the reactor . The mathematical model described in this paper is motivated in part by the CSTR model, but is based on the plug flow reactor (PFR) . Parameter values and initial conditions are chosen so that the numerical performance of the PFR can be compared to that of the CSTR . In simulations bearing a remarkable qualitative and quantitative resemblance to those of the CSTR it is found that the invader is virtually eliminated, despite the fact that it has uptake rate and affinity for the wall identical to those of the resident . The PFR model is then parametrized using data for the human large intestine, and the two-strain simulations are repeated . Though obvious quantitative differences are noted, the more important qualitative outcome is preserved . It is also found that when three strains compete for a single nutrient and for adhesion sites there exists a steady-state solution characterized by the segregation of the bacterial strains into separate nonoverlapping segments along the wall of the reactor.

J Immunol, 2001 Jun 15, 166(12), 7469 - 76
Cytosolic phospholipase A2 participates with TNF-alpha in the induction of apoptosis of human macrophages infected with Mycobacterium tuberculosis H37Ra; Duan L et al.; Macrophage (MPhi) apoptosis, an important innate microbial defense mechanism induced by Mycobacterium tuberculosis (Mtb) H37Ra, depends on the induction of TNF-alpha synthesis . When protein synthesis is blocked, both infection with Mtb and addition of TNF-alpha are required to induce caspase 9 activation, caspase 3 activation and apoptosis . In this study, we show that the second protein synthesis-independent signal involves activation of group IV cytosolic phospholipase A2 (cPLA2) . Apoptosis of Mtb-infected MPhi and concomitant arachidonic acid release are abrogated by group IV cPLA2 inhibitors (methyl arachidonyl fluorophosphate and methyl trifluoromethyl ketone), but not by inhibitors of group VI Ca2+-independent (iPLA2; bromoenol lactone) or of secretory low molecular mass PLA2 . In MPhi homogenates, the predominant PLA2 activity showed the same inhibitor sensitivity pattern and preferred arachidonic acid over palmitic acid in substrates, also indicating the presence of one or more group IV cPLA2 enzymes . In concordance with these findings, MPhi lysates contained transcripts and protein for group IV cPLA2-alpha and cPLA2-gamma . Importantly, group IV cPLA2 inhibitors significantly reduced MPhi antimycobacterial activity and addition of arachidonic acid, the major product of group IV cPLA2, to infected MPhi treated with cPLA2 inhibitors completely restored the antimycobacterial activity . Importantly, addition of arachidonic acid alone to infected MPhi significantly reduced the mycobacterial burden . These findings indicate that Mtb induces MPhi apoptosis by independent signaling through at least two pathways, TNF-alpha and cPLA2, which are both also critical for antimycobacterial defense of the MPhi.

J Immunol, 2001 Jun 15, 166(12), 7389 - 97
Gamma delta T cell-deficient mice have a down-regulated CD8+ T cell immune response against Encephalitozoon cuniculi infection; Moretto M et al.; Gamma(delta) T cells have been reported to play an essential effector role during the early immune response against a wide variety of infectious agents . Recent studies have suggested that the gamma(delta) T cell subtype may also be important for the induction of adaptive immune response against certain microbial pathogens . In the present study, an early increase of gamma(delta) T cells during murine infection with Encephalitozoon cuniculi, an intracellular parasite, was observed . The role of gamma(delta) T cells against E . cuniculi infection was further evaluated by using gene-knockout mice . Mice lacking gamma(delta) T cells were susceptible to E . cuniculi infection at high challenge doses . The reduced resistance of delta(-/-) mice was attributed to a down-regulated CD8+ immune response . Compared with parental wild-type animals, suboptimal Ag-specific CD8+ T cell immunity against E . cuniculi infection was noted in delta(-/-) mice . The splenocytes from infected knockout mice exhibited a lower frequency of Ag-specific CD8+ T cells . Moreover, adoptive transfer of immune TCR(alpha)beta+ CD8+ cells from the delta(-/-) mice failed to protect naive CD8(-/-) mice against a lethal E . cuniculi challenge . Our studies suggest that gamma(delta) T cells, due to their ability to produce cytokines, are important for the optimal priming of CD8+ T cell immunity against E . cuniculi infection . This is the first evidence of a parasitic infection in which down-regulation of CD8+ T cell immune response in the absence of gamma(delta) T cells has been demonstrated.

J Immunol, 2001 Jun 15, 166(12), 7128 - 35
An essential role of the NF-kappa B/Toll-like receptor pathway in induction of inflammatory and tissue-repair gene expression by necrotic cells; Li M et al.; Tissue damage induced by infection or injury can result in necrosis, a mode of cell death characterized by induction of an inflammatory response . In contrast, cells dying by apoptosis do not induce inflammation . However, the reasons for underlying differences between these two modes of cell death in inducing inflammation are not known . Here we show that necrotic cells, but not apoptotic cells, activate NF-kappaB and induce expression of genes involved in inflammatory and tissue-repair responses, including neutrophil-specific chemokine genes KC and macrophage-inflammatory protein-2, in viable fibroblasts and macrophages . Intriguingly, NF-kappaB activation by necrotic cells was dependent on Toll-like receptor 2, a signaling pathway that induces inflammation in response to microbial agents . These results have identified a novel mechanism by which cell necrosis, but not apoptosis, can induce expression of genes involved in inflammation and tissue-repair responses . Furthermore, these results also demonstrate that the NF-kappaB/Toll-like receptor 2 pathway can be activated both by exogenous microbial agents and endogenous inflammatory stimuli.

Blood, 2001 Jun 15, 97(12), 3790 - 7
Activation of protease-activated receptors by gingipains from Porphyromonas gingivalis leads to platelet aggregation: a new trait in microbial pathogenicity; Lourbakos A et al.; The bacterium Porphyromonas gingivalis is a major etiologic agent in the pathogenesis of adult periodontitis in humans . Cysteine proteinases produced by this pathogen, termed gingipains, are considered to be important virulence factors . Among many other potentially deleterious activities, arginine-specific gingipains-R (RgpB and HRgpA) efficiently activate coagulation factors . To further expand knowledge of the interaction between gingipains and the clotting cascade, this study examined their effects on cellular components of the coagulation system . The enzymes induced an increase in intracellular calcium in human platelets at nanomolar concentrations and caused platelet aggregation with efficiency comparable to thrombin . Both effects were dependent on the proteolytic activity of the enzymes . Based on desensitization studies carried out with thrombin and peptide receptor agonists, and immunoinhibition experiments, gingipains-R appeared to be activating the protease-activated receptors, (PAR)-1 and -4, expressed on the surface of platelets . This was confirmed by the finding that HRgpA and RgpB potently activated PAR-1 and PAR-4 in transfected cells stably expressing these receptors . Cumulatively, the results indicate the existence of a novel pathway of host cell activation by bacterial proteinases through PAR cleavage . This mechanism not only represents a new trait in bacterial pathogenicity, but may also explain an emerging link between periodontitis and cardiovascular disease . (Blood . 2001;97:3790-3797)

Biosci Biotechnol Biochem, 2001 Apr, 65(4), 982 - 5
Improvement of shark type I collagen with microbial transglutaminase in urea; Nomura Y et al.; In the presence of urea, type I collagen could form a gel with crosslinks with microbial transglutaminase (MTGase) . Collagen self-assembly was accelerated with the addition of MTGase . The proportion of reconstructed collagen fibrils was raised with the addition of MTGase . MTGase-treated collagen gel remained gelled at high temperatures at which collagen denatured . By treatment with MTGase, collagen could form the gel under impossible condition to collagen self-assembly, and that denaturation temperature was raised.

Croat Med J, 2001 Jun, 42(3), 260 - 6
DNA typing from skeletal remains: evaluation of multiplex and megaplex STR systems on DNA isolated from bone and teeth samples; Alonso A et al.; AIM: To evaluate the performance of three multiplex short tandem repeat (STR) systems (AmpflSTR Profiler, AmpflSTR Profiler Plus, and AmpflSTR COfiler), and a megaplex STR system (PowerPlex 16) on DNA extracted from the skeletal remains . By performing a microbial DNA challenge study, we also evaluated the influence of microbial DNA on human DNA typing . METHODS: A subset of 86 DNA extracts isolated from 8-50 years old bone and teeth samples, corresponding to 20 identification cases from mass graves in Croatia and Bosnia and Herzegovina, and to 4 paternity cases involving deceased parents in Spain, were analyzed by the above systems . RESULTS: Bone samples with no detectable human DNA (tested with Quantiblot), as well as teeth samples with detectable human DNA, were successfully amplified . Surprisingly, even in highly degraded samples, PowerPlex 16 offered very robust amplification for the both Penta E and Penta D markers . We observed a few non-specific extra peaks of 202 and 308 base pairs, which appeared to match 16S rRNA of the Pseudomonas halodenitrificans . CONCLUSION: AmpflSTR Profiler Kit, AmpflSTR Profiler Plus Kit, the AmpflSTR COfiler Kit, and the PowerPlex 16 system are very sensitive multiplex STR amplification systems, which can be successfully used to obtain a multilocus STR profile from old teeth and bone samples with minimal amounts (pg) of human DNA or even with no detectable human DNA.

Biotechnol Prog, 2001 May-Jun, 17(3), 568 - 72
Raspberry ketone from submerged cultured cells of the basidiomycete Nidula niveo-tomentosa; Boker A et al.; The basidiomycete Nidula niveo-tomentosa produced 4-(4-hydroxyphenyl)-butan-2-one (raspberry ketone), one of the character impact components of raspberry flavor, and its corresponding alcohol . A systematic attempt was made to improve the productivity of this fungus . Variation of nutrient medium composition, precursor amount, time of supplementation, and cultivation period yielded a 50-fold increase in metabolite concentrations . Raspberry ketone and alcohol were easily isolated from the culture medium by solvent extraction . Glycosidically bound forms or accumulation of raspberry compounds in fungal cells were not detected . This microbial process offers an alternative for the production of natural raspberry flavor.

Ecotoxicol Environ Saf, 2001 Jun, 49(2), 164 - 70
Environmental dissipation of fungicide triphenyltin acetate and its potential as a groundwater contaminant; Yen JH et al.; The effects of various factors on fungicide triphenyltin acetate dissipation in selected soil types were studied; temperature is clearly the most important factor of these . Residues of this fungicide in Fangtzupo clay loam and Lanyang loam incubated at 30 degrees C for 32 days (water content 100, 70, or 40% of field capacity) were 25% of the original amounts . In soil samples incubated at 10, 30, or 40 degrees C with 100% field capacity water content, residues were 80, 26, and 5.5% for Fangtzupo soil, respectively, and 83, 26, and 7.0% for Lanyang soil, respectively . No significant difference in dissipation rate was found between sterilized and unsterilized soil, suggesting that microbial degradation is not an important factor in this process . Rapid degradation rates were observed-half-lives of 8.3 to 19.4 days in Fangtzupo clay loam and 8.0 to 16.3 days in Lanyang loam at temperatures ranging from 30 to 40 degrees C (soil water content of 100, 70, and 40% of field capacity) . Significant increases in half-life (approximately 150 days) occurred at lower temperatures (10 degrees C) in both soil types . The potential of triphenyltin acetate to contaminate groundwater was tested using the behavior assessment and groundwater pollution-potential models . Results indicate that the leaching rate of the fungicide is very slow (1.0 cm day(-1)) under normal conditions .

Antonie Van Leeuwenhoek, 2000 Dec, 78(3-4), 399 - 405
Rare genera of actinomycetes as potential producers of new antibiotics; Lazzarini A et al.; A literature survey covering more than twenty-three thousand bioactive microbial products including eight thousand antiinfectives demonstrated the increasing relevance of the so called 'rare' actinomycetes as a source of new antibiotics . Past and present efforts in the isolation of rare actinomycetes have enriched the Biosearch Italia Strain Collection with more than twenty thousand strains, showing that, when selective isolation methods are developed and extensively applied, some genera, such as Actinomadura, Actinoplanes, Micromonospora, Microtetraspora, are not rare at all and can be recovered from many soil samples . The current focus is on the isolation of members of Streptosporangiaceae family, given their promising chemical diversity.

Mikrobiologiia, 2001 Mar-Apr, 70(2), 149 - 67
{Bacterial soil variety: evaluation of methods, possibilities, and prospects }; Dobrovol'skaia TG et al.; The paper presents a comparative description of the modern molecular genetic and routine culture techniques for assessing microbial diversity in soils and gives analysis for the different results obtained by these two groups of methods . The necessity of the collaboration of soil scientists, microbiologists, and molecular biologists in integrating different research methods for a proper assessment of soil microbial diversity is discussed . The paramount importance of soil as the source and reserve of biodiversity on the Earth is emphasized.

Water Sci Technol, 2001, 43(7), 271 - 8
Identification of model structure for aquatic ecosystems using regionalized sensitivity analysis; Osidele OO et al.; The Regionalized Sensitivity Analysis (RSA) was developed in 1978, for identifying critical unknown processes in poorly defined systems, thus directing the focus of further scientific investigations . Here, we demonstrate its application to model structure identification, by ranking the constituent hypotheses and identifying the critical elements for progressive revision of the model . Our case study is Lake Oglethorpe--a small monomictic impoundment in South-eastern Georgia, USA . Recent studies indicate that the warm temperate regional climate affords an extended growing season--typically from March to October--which promotes bacterial productivity in the lake . The result is a summer food web dominated by microbial processes, in contrast to the conventional phytoplankton-dominated food chains typically observed in the cold temperate lakes of Europe and North America . Starting with a simple phytoplankton-based food web model and a qualitative definition of system behaviour, we use the RSA procedure to establish the critical role of bacteria-mediated decomposition in Lake Oglethorpe, thus justifying the inclusion of microbial processes . Further analysis reveals the importance of size-dependent selective consumption of phytoplankton and bacteria . Finally, we discuss important practical implications of this novel application of the RSA regarding sampling efficiency and statistical robustness.

Am J Ind Med, 2001 Jun, 39(6), 616 - 28
Hypersensitivity pneumonitis in a metal-working environment; Hodgson MJ et al.; BACKGROUND: An outbreak of lung disease among workers in a metal-working plant included 16 biopsy-confirmed cases of hypersensitivity pneumonitis and additional patients with asthma, bronchiolitis and emphysema, usual interstitial pneumonitis, and sarcoidosis . Study design Clinical examination of patients; cross-sectional questionnaire survey of the outbreak plant and two control plant areas, one with and one without MWF exposures, in a separate facility; industrial hygiene survey with laboratory characterization of microbial flora; and immunological investigation . METHODS: Patients with suspected hypersensitivity pneumonitis underwent a clinical examination including detailed lung function, imaging, and tissue studies . A plant walk-through identified metal-working processes, microbial aerosols, and work practices . Microbial characteristics of the three microbial aerosol-producing processes were characterized . Antibodies to those agents were determined in patient sera . A questionnaire survey was conducted in the case plant and in two areas of a control plant, one with and one without metal-working fluids exposure . RESULTS: Thirty-nine (79.6%) patients described symptoms consistent with work-related lung disease, eight received other diagnoses, and two did not complete their examinations . Sixteen patients had hypersensitivity pneumonitis confirmed on biopsy . Mean decrements in lung forced expiratory volume in 1 s and force vital capacity from before to after work were similar in the 16 biopsy-confirmed cases of hypersensitivity pneumonitis ( - 6.3%; - 7.2%) and the 19 symptomatic patients without biopsies ( - 11.2%, - 10.1%) . Symptoms were more common in the case plant than in a non-MWF control plant area . Three sources of water-based aerosols were identified that grew similar microbial flora . Although machining increased airborne bacterial levels, the increase was not related to the concentration of viable bacteria in the sumps . Antibody testing did not identify a specific single organisms . Endotoxin levels were similar in case and MWF control plant . CONCLUSIONS: Lung disease in environments with water-based aerosols may be more common than usually recognized . Patients with HP often present with only subtle abnormalities and may be missed if multiple clinical abnormalities are required to document disease .

Nature, 2001 May 31, 411(6837), 599 - 603
Association of NOD2 leucine-rich repeat variants with susceptibility to Crohn's disease; Hugot JP et al.; Crohn's disease and ulcerative colitis, the two main types of chronic inflammatory bowel disease, are multifactorial conditions of unknown aetiology . A susceptibility locus for Crohn's disease has been mapped to chromosome 16 . Here we have used a positional-cloning strategy, based on linkage analysis followed by linkage disequilibrium mapping, to identify three independent associations for Crohn's disease: a frameshift variant and two missense variants of NOD2, encoding a member of the Apaf-1/Ced-4 superfamily of apoptosis regulators that is expressed in monocytes . These NOD2 variants alter the structure of either the leucine-rich repeat domain of the protein or the adjacent region . NOD2 activates nuclear factor NF-kB; this activating function is regulated by the carboxy-terminal leucine-rich repeat domain, which has an inhibitory role and also acts as an intracellular receptor for components of microbial pathogens . These observations suggest that the NOD2 gene product confers susceptibility to Crohn's disease by altering the recognition of these components and/or by over-activating NF-kB in monocytes, thus documenting a molecular model for the pathogenic mechanism of Crohn's disease that can now be further investigated.

Nat Med, 2001 Jun, 7(6), 732 - 7
Overexpression of heat-shock proteins reduces survival of Mycobacterium tuberculosis in the chronic phase of infection; Stewart GR et al.; Elevated expression of heat-shock proteins (HSPs) can benefit a microbial pathogen struggling to penetrate host defenses during infection, but at the same time might provide a crucial signal alerting the host immune system to its presence . To determine which of these effects predominate, we constructed a mutant strain of Mycobacterium tuberculosis that constitutively overexpresses Hsp70 proteins . Although the mutant was fully virulent in the initial stage of infection, it was significantly impaired in its ability to persist during the subsequent chronic phase . Induction of microbial genes encoding HSPs might provide a novel strategy to boost the immune response of individuals with latent tuberculosis infection.

J Nutr, 2001 Jun, 131(6), 1792 - 7
Microbial phytase does not improve protein-amino acid utilization in soybean meal fed to young chickens; Peter CM et al.; Three growth trials were conducted with young chicks to evaluate crude protein (CP) utilization in soybean meal (SBM) as affected by dietary addition of microbial phytase . In assay 1, chicks were fed two CP-deficient (50 or 150 g CP/kg) levels of dehulled SBM, and each SBM level was then supplemented with equimolar amounts of cystine or methionine (Met) or with 1200 U phytase/kg . At 50 g CP/kg, cystine or Met supplementation improved (P < 0.05) measures of growth performance, but when 150 g CP/kg from SBM was fed, only Met addition improved (P < 0.05) weight gain, food efficiency and protein efficiency ratio (PER) . Thus, Cys was more limiting than Met in the diet that contained 50 g CP/kg, but Met was clearly first-limiting in the diet that contained 150 g CP/kg . Phytase supplementation did not improve (P > 0.10) chick performance at either level of CP . Chicks in assay 2 were fed 100 g CP/kg furnished by SBM, casein or corn gluten meal in the absence and presence of 1200 U phytase/kg . Weight gain, gain/food and PER values were greater (P < 0.05) in chicks fed SBM than in those fed casein, and greater (P < 0.05) in chicks fed casein than in those fed corn gluten meal . Phytase supplementation had no effect (P > 0.10) on any measure of chick performance, regardless of the protein source fed . In assay 3, three deficient levels of CP (50, 100 and 150 g/kg) from SBM were fed in the absence and presence of 1200 U dietary phytase/kg . Weight gain, food efficiency and protein accretion increased linearly (P < 0.05) as a function of protein intake, but phytase supplementation had no effect (P > 0.10) on slopes of the body weight and protein accretion curves . Likewise, phytase addition did not affect (P > 0.10) measures of protein utilization, i.e., weight gain/protein intake and protein gain/protein intake at any of the CP levels that were fed . Because sulfur amino acids are the growth-limiting factors when protein-deficient levels of SBM are fed to young chicks, we conclude that dietary addition of phytase does not improve sulfur amino acid utilization in SBM.

Brain Res, 2001 Jun 1, 902(2), 171 - 7
Monocyte chemoattractant protein-1 expressed in neurons and astrocytes during focal ischemia in mice; Che X et al.; Focal cerebral ischemia elicits an inflammatory response characterized by the infiltration and accumulation of leukocytes, as well as the secretion of inflammatory mediators (Clark et al., Brain Res . Bull., 35 (1994) 387-392; Garcia et al., Am . J . Pathol., 144 (1994) 188-199; Wang et al., J . Neurochem . 71 (1998) 1194-1204) . Leukocytes eliminate microbial invaders and necrotizing tissue debris, and can also turn against surrounding healthy tissue and exacerbate tissue injury (Furie and Randolph, Am . J . Pathol., 146 (1995) 1287-1301; Kochanek and Hallenbeck, Stroke 23 (1992) 1367-1379) . Inflammatory mediators are considered to play an important role in attracting and stimulating leukocytes (Weiss, N . Engl . J . Med., 320 (1989) 365-376) . Monocyte chemoattractant protein-1 (MCP-1) functions as an inflammatory mediator, whose source and role in focal cerebral ischemia is worth studying . MCP-1, a potent chemoattractant factor, may play an important role in ischemia-induced inflammatory response . The aim of the present study is to determine the time course and cell type of MCP-1 protein expression after permanent focal ischemia in mice . ELISA and immunohistochemical staining were used to detect the expression of MCP-1 protein after 0 h, 2 h, 4 h, 12 h, 1 day, 2 days, 3 days, 5 days and 7 days of middle cerebral artery occlusion (n=3-5 in each group) . Double-labeled fluorescent staining was used to examine the cellular localization of MCP-1 . The results demonstrated that MCP-1 expression was mainly observed in the ischemic core after 12 h of middle cerebral artery occlusion, then gradually increased and extended to the ischemic perifocal area . MCP-1 expression peaked at 2 days and 3 days, and gradually decreased after 5 days of MCAO . Double-labeled immunostaining for MCP-1 and neuron specific enolase (NSE) or glial fibrillary acidic protein (GFAP) showed that MCP-1 positive neurons were observed as early as 12 h of ischemia, while MCP-1 positive astrocytes were observed after 2 days of ischemia . These results support the functional role of MCP-1 in ischemic brain injury and reveal a distinct temporal and spatial expression of MCP-1 in cells believed to be neurons and astrocytes.

BMC Microbiol . 2001;1(1):5 . Epub 2001 May 16.
Phylogenetic analysis of methanogens from the bovine rumen; Whitford MF et al.; BACKGROUND: Interest in methanogens from ruminants has resulted from the role of methane in global warming and from the fact that cattle typically lose 6 % of ingested energy as methane . Several species of methanogens have been isolated from ruminants . However they are difficult to culture, few have been consistently found in high numbers, and it is likely that major species of rumen methanogens are yet to be identified . RESULTS: Total DNA from clarified bovine rumen fluid was amplified using primers specific for Archaeal 16S rRNA gene sequences (rDNA) . Phylogenetic analysis of 41 rDNA sequences identified three clusters of methanogens . The largest cluster contained two distinct subclusters with rDNA sequences similar to Methanobrevibacter ruminantium 16S rDNA . A second cluster contained sequences related to 16S rDNA from Methanosphaera stadtmanae, an organism not previously described in the rumen . The third cluster contained rDNA sequences that may form a novel group of rumen methanogens . CONCLUSIONS: The current set of 16S rRNA hybridization probes targeting methanogenic Archaea does not cover the phylogenetic diversity present in the rumen and possibly other gastro-intestinal tract environments . New probes and quantitative PCR assays are needed to determine the distribution of the newly identified methanogen clusters in rumen microbial communities.

J Dairy Sci, 2001 May, 84(5), 1020 - 6
Recombinant lamb chymosin as an alternative coagulating enzyme in cheese production; Rogelj I et al.; Recombinant lamb chymosin (RLC) was prepared and tested for its potential use in cheese production . The milk clotting activity and proteolytic activity of RLC were evaluated in comparison with commercial recombinant calf chymosin (RCC), cow rennet (CR), and microbial coagulant (MC) . RLC, RCC, and MC showed similar responses to pH, with a sharp increase of the coagulation time at pH 6.6 to 6.8 and decrease of curd firmness at the pH 6.5 to 6.6 . In the case of CR, we observed two clear increases in the coagulation time and decreases in the curd firmness, at pH 6.4 to 6.5 and 6.6 to 6.8 . Optimal clotting activity was obtained for RLC at 40 degrees C, for both CR and RCC at 45 degrees C, and for MC at 60 degrees C . The temperature instability of RLC at temperatures above 45 degrees C could constitute a benefit in making hard cheese varieties . The additon of CaCl2 to milk resulted in enhanced clotting activity of all coagulants, most prominently for CR . The proteolytic activity of RLC was significantly lower from that of CR but not significantly different from the activity of RCC . The lower proteolytic activity in the cheese made with RLC did not have negative effect on organoleptic properties . The overall quality of the cheese made with RLC was at least comparable to that of the cheese made with RCC, and both cheeses were better scored than the cheese made with CR.

Chirurg, 2001 May, 72(5), 566 - 72
{Surgical therapy of alveolar echinococcosis and long-term outcome}; Buttenschoen K et al.; INTRODUCTION: The incidence of alveolar echinococcosis (AE) is low, and studies and progress reports with regard to surgical procedures are rare . METHODS: Retrospective analysis of surgical therapy of AE and its long-term results between 1983 and 2000 by evaluating medical records and questionnaires . SETTING: German university hospital within the endemic area . RESULTS: Twenty-five surgical procedures were performed in 19 patients with AE (12x partial resection of the liver, 3 of them with additional extrahepatic resection; 3x just extrahepatic resection, 4x bilidigestive anastomosis, 5x exploratory laparotomy, 1x bypass procedure) . Fifteen patients were operated on the first time with that diagnosis, four due to a relapse . Seven surgical procedures were estimated to be curative, whereas 18 were palliative, because the parasitic mass could not be resected in toto . One patient died from persistent systemic sepsis as a consequence of microbial superinvasion of a splenic parasitic mass . Morbidity was 28% . All patients had additional medical treatment and periodic follow-up . Three of seven patients estimated for curative surgery developed a relapse . One of the patients discharged following palliative surgery died 13 years after diagnosis with liver insufficiency . Advances in conservative and interventional treatments have greatly improved the prognosis of the disease . CONCLUSION: Curative surgery for AE is feasible only in a minority of patients, because frequently the disease has already spread widely when diagnosed . The minimum distance between the lesion and the cut surface should be 2 cm . Taking the advances in conservative treatment into consideration, the benefit of palliative surgery is uncertain and today there is no evidence for prolonged survival by palliative surgical procedures . Palliative surgery should therefore be reserved for cases with complications that could not be managed by conservative and interventional treatment.

Arch Microbiol, 2001 Apr, 175(4), 250 - 8
Microbial biosynthesis of halometabolites; van Pee KH; Halometabolites are compounds that are commonly found in nature and they are produced by many different organisms . Whereas bromometabolites can mainly be found in the marine environment, chlorometabolites are predominately produced by terrestrial organisms; iodo- and fluorocompounds are only produced infrequently . The halogen atoms are incorporated into organic compounds by enzyme-catalyzed reactions with halide ions as the halogen source . For over 40 years haloperoxidases were thought to be responsible for the incorporation of halogen atoms into organic molecules . However, haloperoxidases lack substrate specificity and regioselectivity, and the connection of haloperoxidases with the in vivo formation of halometabolites has never been demonstrated . Recently, molecular genetic investigations showed that, at least in bacteria, a different class of halogenases is involved in halometabolite formation . These halogenases were found to require FADH2, which can be produced from FAD and NADH by unspecific flavin reductases . In addition to FADH2, oxygen and halide ions (chloride and bromide) are necessary for the halogenation reaction . The FADH2-dependent halogenases show substrate specificity and regioselectivity, and their genes have been detected in many halometabolite-producing bacteria, suggesting that this type of halogenating enzymes constitutes the major source for halometabolite formation in bacteria and possibly also in other organisms.

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001, 36(2), 123 - 39
Effect of bioaugmentation on microbial transport, water infiltration, moisture loss, and surface hardness in pristine and contaminated soils; Mehmannavaz R et al.; Three different soils, a clay, a pristine sandy loam and a PCB-contaminated sandy loam, were bioaugmented to determine the influence of clay content and contaminants on the transport of bacteria in unsaturated soils, using surface irrigation water as a transport medium . The results indicate that the transport of the implanted bacteria was influenced negatively more by the presence of PCBs than by the clay content of the soil . Transport was directly related to the frequency of irrigation and length of the intervals between irrigation periods, making these variables important factors to consider when applying bioaugmentation via downward percolating water . Other parameters measured after bacterial bioaugmentation were water infiltration, moisture loss, and surface hardness of these soils . Surface water infiltration was affected more by the soil clay content than by the hydrophobic contaminant . Infiltration was significantly but differently influenced by bioaugmentation, positively in clay, negatively in sandy loam, and negatively (to a lesser extent) in the PCB-contaminated sandy loam soils . Moisture loss was slower in the bioaugmented soil than in the control soils, with this difference being most pronounced in the PCB soil . High moisture loss in the bioaugmented clay soil rendered it the hardest soil for surface penetration.

Water Sci Technol, 2000, 41(3), 9 - 16
Microbial ecology of the leach bed anaerobic digestion of unsorted municipal solid waste; Silvey P et al.; The microbial ecology of the sequential, leach-bed, mesophilic anaerobic digestion of unsorted, coarse municipal solid waste (MSW) was examined over 80 days . The methane yield was approximately 75% of the ultimate biochemical methane potential (BMP) of the waste loaded into the digesters . The operational strategy involved a sequence of two digesters containing fresh and anaerobically stabilised MSW respectively . Cell wall phospholipid fatty acid (PLFA) and ether lipid (PLEL) analysis was used to monitor changes in microbial biomass . Both Bacterial and Archaeal biomass were heavily influenced by pH during the two-week start up period . Archaeal biomass peaked just before the methane production rate reached a maximum whereas Bacterial biomass peaked at a later stage . Changes in the phylogenetic diversity of the population were monitored by denaturing gradient gel electrophoresis (DGGE) . An analysis of the changes in DGGE banding patterns suggested that rapid start-up of a new reactor was effected by inoculation as well as the provision of buffering capacity from the mature reactor leachate.

Water Sci Technol, 2000, 41(3), 1 - 8
Monitoring of a biogas process using electronic gas sensors and near-infrared spectroscopy (NIR); Nordberg A et al.; The use of electronic gas sensors and near-infrared spectroscopy (NIR) to monitor the dynamics in a biogas process was evaluated using multivariate data analysis . The digester, a completely stirred 8 l tank reactor fed with a mixture of cellulose, albumin and minerals, was exposed to an overload of glucose after which monitoring of electronic gas sensor responses, NIR spectra as well as traditional chemical variables and analysis of microbial community structure were done . The responses from an array of electronic gas sensors consisting of MOS and MOSFET-sensors were correlated against volatile compounds in the headspace using partial least square (PLS) regressions . The root mean square error of prediction (RMSEP) was 0.15 g/l for acetate in the range of 0.14-1.72 g/l and the RMSEP for methane was 2.3% in the range of 27-73% . Selected wavelengths from the second derivative of the original NIR spectra (400-2500 nm) resulted in a PLS-model for predicting microbial biomass, measured as total phospholipid fatty acids, with a RMSEP of 9 nmol/ml in the range of 163-293 nmol/ml . The NIR model developed for acetate had a RMSEP of 0.20 g/l within the range of 0.14-1.72 g/l . The results clearly show that both NIR and an array of electronic gas sensors can provide simultaneous non-invasive in situ monitoring of important process variables in anaerobic digesters.

Water Sci Technol, 2001, 43(6), 193 - 6
Effect of carbohydrate and protein in the EPS on sludge settling characteristics; Shin HS et al.; EPSs have been believed to play a bonding role in microbial floc formation . However, the precise role is not well known . In this study, sludge settling characteristics and the carbohydrate to protein ratio in the EPS were tested at various airflow rates . Sludge was collected from three modified sequencing batch reacetors (MSBRs), which were operated with airflow rates of 0.8 L/min, 2 L/min and 4 L/min, respectively . During the operation periods, the reactor operated at an airflow rate of 0.8 L/min showed a sludge volume index (SVI) of 80 to 90 mL/g and a constant ratio of carbohydrate to protein in the EPS, while a significant increase of this ratio and the SVI occurred in the other reactors . High airflow rate increased the amount of carbohydrate in the EPS, but the protein level was almost constant for reactors with airflow rates of 2 L/min and 4 L/min . The higher ratio of carbohydrate to protein caused the bulking of the sludge; hence it was not favourable for sludge settling . The ratio of carbohydrate and protein in the EPS is inferred to be essential for solid floc formation.

Infect Control Hosp Epidemiol, 2001 Apr, 22(4), 202 - 5
Bacterial contamination associated with electronic faucets: a new risk for healthcare facilities; Hargreaves J et al.; OBJECTIVE: To investigate the safety of the hospital water supply following a major flood . DESIGN: Surveillance was conducted of the hospital water supply as it entered the hospital and at randomly selected water faucets throughout the facility . SETTING: A newly constructed surgical critical-care unit in a 265-bed community hospital that had to be evacuated and was out of operation for 6 weeks following a major flood of the city . METHODS: Random water samples throughout the facility were analyzed for heterotrophic plate counts (HPCs), chlorine, and coliforms utilizing standard methods . RESULTS: Water samples entering the hospital met appropriate standards, indicating the city water distribution system was not contaminated . Of 169 faucets tested, 13 (22%) of 59 electronic faucets exceeded the HPC threshold, and 12 (11%) of 110 manual faucets exceeded the HPC threshold (P<.14) . A comparison of two brands of electronic faucets with manual faucets and with each other revealed that the HPC threshold was exceeded by 11 (32%) of 34 brand A faucets as compared to 12 (11%) of 110 manual faucets (P<.006) . The HPC threshold was exceeded by 2 (8%) of 25 brand B faucets compared to 12 (11%) of 110 manual faucets (P<.94) . Contamination rates of brand A and brand B faucets differed significantly (P<.003) . Similar testing 2 months after hyperchlorination of the water supply indicated that the HPC threshold was exceeded by 16 (52%) of 31 brand A faucets compared to 10 (9.%) of 110 manual faucets (P<.0000003) and by 2 (18%) of 25 brand B faucets compared to 10 (9%) of 110 manual faucets (P=1.0) . CONCLUSIONS: A certain brand of electronic water faucet used in the hospital was associated with unacceptable levels of microbial growth in water and was a continuing source of bacteria potentially hazardous to patients.

Water Sci Technol, 2001, 43(1), 51 - 7
A molecular method to study population and activity dynamics in anaerobic digestors; Delbes C et al.; The applicability of a new molecular fingerprinting method (Single Strand Conformation Polymorphism) to study the microbial populations of anaerobic digestors was investigated . After extraction of total nucleic acids, the 16S rDNA and 16S rRNA molecules were amplified and the amplicons were separated by SSCP electrophoresis . Characteristic and complex peak patterns were obtained, where each peak could be correlated with the 16S rDNA sequence of one micro-organism . The rDNA peak patterns should consist of the most abundant sequences and thus would reflect the diversity of prominent species of different digestors . Ribosomal DNA patterns were compared to rRNA patterns and revealed the bacteria that were the most active metabolically . The SSCP method also revealed dynamic changes in the presence and activity of populations, following perturbations such as an acidic shock which caused an increase in activity of two species . After cloning the 16S rDNA, the species corresponding to the peaks of interest, such as the archaeal species, could be identified by screening the clones according to their SSCP patterns and sequencing the 16S rDNA.

Curr Opin Microbiol, 2001 Jun, 4(3), 330 - 5
Microbial pathway engineering for industrial processes: evolution, combinatorial biosynthesis and rational design; Rohlin L et al.; Microbial pathway engineering has made significant progress in multiple areas . Many examples of successful pathway engineering for specialty and fine chemicals have been reported in the past two years . Novel carotenoids and polyketides have been synthesized using molecular evolution and combinatorial strategies . In addition, rational design approaches based on metabolic control have been reported to increase metabolic flux to specific products . Experimental and computational tools have been developed to aid in design, reconstruction and analysis of non-native pathways . It is expected that a hybrid of evolutionary, combinatorial and rational design approaches will yield significant advances in the near future.

FEMS Microbiol Ecol, 2001 Jun, 36(1), 11 - 19
The effect of long-term mercury pollution on the soil microbial community; Muller AK et al.; The effect of long-term exposure to mercury on the soil microbial community was investigated in soil from three different sites along a pollution gradient . The amount of total and bioavailable mercury was negatively correlated to the distance from the center of contamination . The size of the bacterial and protozoan populations was reduced in the most contaminated soil, whereas there was no significant difference in fungal biomass measured as chitinase activity . Based on the number of colony morphotypes, moreover, the culturable bacterial population was structurally less diverse and contained a higher proportion of resistant and fast-growing forms . The profiles of amplified 16S rDNA sequences obtained from community DNA by denaturating gradient gel electrophoresis (DGGE) also reflected the altered community structure and decreased diversity along the mercury gradient as expressed in terms of the number and abundance of bands . The functional potential of the microbial population measured as sole carbon source utilization by Ecoplates((R)) differed between the soils, but there was no change in the number of substrates utilized . The observed changes in the different soil microbial populations are probably a combination of both direct and indirect effects of the mercury contamination.

Chemosphere, 2001 May-Jun, 43(4-7), 643 - 8
Dioxin cycling in aquatic sediments: the Passaic River Estuary; Fu QS et al.; The contribution of dechlorination reactions to the transformation of dioxins in river sediments was evaluated under a range of geochemical conditions mimicking freshwater, estuarine and marine environments, and interpreted in the light of recent evidence for their accumulation at the air-water interface . The yield of dechlorinated products increased with salinity, but never exceeded 20% of the initial dioxins present . Among the homologue groups in saline conditions, diCDDs were dominant at 32-47 mol% (8-16 nM) . The production of 2,3,7,8-TCDD increased with decreasing salinity and in the presence of dissolved organic matter, exhibiting a maximum ratio (2,3,7,8-TCDD:non-2,3,7,8-TCDD) of 0.5 . These differences in patterns may be related to the dominant microbial respiratory processes responsible for carbon turnover under the imposed conditions, and are strongly affected by the presence of organic matter . Based on these results, a conceptual dechlorination and carbon turnover model is proposed to help explain the likely reactivity of dioxins in the Passaic River Estuary.

Microbiol Res, 2001, 156(1), 13 - 8
Cell lysis in Escherichia coli cultures stimulates growth and biosynthesis of recombinant proteins in surviving cells; Corchero JL et al.; Cell growth and production of recombinant proteins in stationary phase cultures of Escherichia coli recover concomitantly with spontaneous lysis of a fraction of the ageing cell population . Further exploration of this event has indicated that sonic cell disruption stimulates both cell growth and synthesis of plasmid-encoded recombinant proteins, even in exponentially growing cultures . These observations indicate an efficient cell utilisation of released intracellular material and also that this capability is not restricted to extreme nutrient-starving conditions . In addition, the efficient re-conversion of waste cell material can be viewed as a potential strategy for an extreme exploitation of carbon sources and cell metabolites in production processes of both recombinant and non-recombinant microbial products.

Blood, 2001 Jun 1, 97(11), 3470 - 7
Investigation of human spleen dendritic cell phenotype and distribution reveals evidence of in vivo activation in a subset of organ donors; McIlroy D et al.; Although the mouse spleen dendritic cell (DC) is perhaps the most intensively studied DC type, little has been published concerning its human equivalent . In this report, rare event flow cytometry and in situ immunofluorescence were used to study the surface phenotype and distribution of HLA-DR(+) CD3(-)14(-)16(-)19(-) human spleen DC . Spleens from organ donors with different clinical histories were used . Most (81% +/- 9%; n = 14) spleen DCs expressed high levels of the integrin CD11c . CD11c(+) DCs were distributed in 3 distinct regions-the peri-arteriolar T-cell zones, the B-cell zones, and the marginal zone, where they formed a ring of cells surrounding the white pulp, just inside a ring of CD14(+) red pulp macrophages, apparently more regularly organized than the previously described marginating DC population in the mouse spleen . The T-cell zones contained CD86(+) DCs, among which a subpopulation expressed CD83 . These mature/activated CD86(+) DCs represented a minority (12% +/- 8%) of total spleen DCs in most organ donors: most spleen DCs are immature . In 3 of 18 (17%) donors, however, most (54%-81%) of spleen DCs were CD86(+), suggesting that in vivo DC activation had occurred . In one donor, a radical shift in DC distribution from the marginal zone to the T-cell zones was also observed . This activation of spleen DCs in vivo was reminiscent of the effects of experimental microbial product injection in mice, and it seemed to correlate with bacterial infection or multiple trauma . (Blood . 2001;97:3470-3477)

J Agric Food Chem, 2001 May, 49(5), 2376 - 81
Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon (Salmo salar) analyzed by GC-MS and multivariate regression; Jorgensen LV et al.; Changes were studied in the concentration of 38 volatile compounds during chilled storage at 5 degrees C of six lots of commercially produced vacuum-packed cold-smoked salmon and sterile cold-smoked salmon . The majority of volatile compounds produced during spoilage of cold-smoked salmon were alcohols, which were produced by microbial activity . Partial least-squares regression of volatile compounds and sensory results allowed for a multiple compound quality index to be developed . This index was based on volatile bacterial metabolites, 1-propanol and 2-butanone, and 2-furancarboxaldehyde produced by autolytic activity . Only a few of the volatile compounds produced during spoilage of cold-smoked salmon had an aroma value high enough to indicate contribution to the spoilage off-flavor of cold-smoked salmon . These were trimethylamine, 3-methylbutanal, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-penten-3-ol, and 1-propanol . The potency and importance of these compounds was confirmed by gas chromatography-olfactometry . The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop biosensors for on-pack shelf-life determinations.

Arch Biochem Biophys, 2000 Dec 15, 384(2), 305 - 10
Molecular cloning of cDNA encoding alpha-N-acetylgalactosaminidase from Acremonium sp . and its expression in yeast; Ashida H et al.; Alpha-N-acetylgalactosaminidase (alpha-GalNAc-ase; EC 3.2.1.49) is an exoglycosidase specific for the hydrolysis of terminal alpha-linked N-acetylgalactosamine in various sugar chains . The cDNA, nagA, encoding alpha-GalNAc-ase from Acremonium sp . was cloned, sequenced, and expressed in yeast Saccharomyces cerevisiae . The nagA contains an open reading frame which encodes for 547 amino acid residues including 21 residues of a signal peptide in its N-terminal . The calculated molecular mass of mature protein from the deduced amino acid sequence of nagA is 57260 Da, which corresponds to the value obtained from SDS-PAGE of native and recombinant enzymes treated with endo-beta-N-acetylglucosaminidase H . The amino acid sequence of NagA showed significant similarity to those of eukaryotic alpha-GalNAc-ases and alpha-galactosidases (alpha-Gal-ases), particularly alpha-Gal-ase A (AglA) from Aspergillus niger . Phylogenetic analysis revealed that NagA does not belong to the cluster of vertebrate alpha-GalNAc-ase and alpha-Gal-ase but forms another cluster with AglA and yeast alpha-Gal-ases . Thus, the evolutionary origin of the fungal alpha-GalNAc-ase is suggested to be different from that of vertebrate alpha-GalNAc-ase . This is the first report of a microbial alpha-GalNAc-ase gene.

Chemosphere, 2001 Jun, 43(8), 1127 - 32
A hybrid fenton oxidation-microbial treatment for soil highly contaminated with benz(a)anthracene; Lee BD et al.; In order to mitigate the strong microbial resistance of benz(a)anthracene {B(a)A} in soil, a hybrid treatment of Fenton oxidation followed microbial culture was carried out . Based on optimal Fenton oxidation . i.e., 1.0 ml of ethanol, 0.2 ml of 0.5 M Fe2+, and 0.3 ml of 30% H2O2 per 1 g of 500 mg B(a)A/kg soil, about 43% of B(a)A-7,12-dione was generated during oxidation of 97% B(a)A . When the comparative biodegradability between B(a)A-contaminated soil and B(a)A-contaminated soil after Fenton oxidation was examined, it was found that 98% of B(a)A-7,12-dione degraded after 63 d in comparison with only 12% of B(a)A over the same period; results demonstrating that Fenton oxidation enhances biodegradability of B(a)A through B(a)A-7,12-dione.

NIAID AIDS Agenda . 1995 Dec;:10-1.
NIAID funds STD research centers . National Institute of Allergy and Infectious Diseases; Hilovsky J; AIDS: Seven research centers have been established by the National Institute of Allergy and Infectious Diseases (NIAID) to support collaborative multi-disciplinary studies of serious infections . The Sexually Transmitted Diseases Cooperative Research Centers (STD-CRCs) will focus on the objectives of the NIAID STD program, which include prevention of four serious consequences of STDs: infertility, adverse outcomes of pregnancy, cancer of the cervix and other anogenital sites, and HIV infection . Investigators will work together to bridge biomedical, clinical, behavioral, and epidemiological research, promote productive collaborations, and facilitate the development of intervention-oriented research . Studies will focus on: preventing reproductive tract infections, evaluating the microbial etiology of non-gonococcal ureteritis, determining new approaches to primary and secondary STD prevention, answering biomedical and behavioral questions associated with chlamydia and gonococcus, and creating prevention strategies .

Environ Microbiol, 2001 Apr, 3(4), 256 - 64
Phylogenetic structure of unusual aquatic microbial formations in Nullarbor caves, Australia; Holmes AJ et al.; The nature of unusual aquatic microbial formations in flooded passages of cave systems in the Nullarbor region of Australia was investigated using electron microscopy and DNA analysis . The caves are located in a semiarid region but intersect the watertable at depths of approximately 100 m below the surface . Throughout submerged portions of the caves divers have noted the presence of unusual microbial formations . These 'microbial mantles' comprise sheets or tongues of mucoid material in which small crystals are embedded . Examination of the biomass revealed it to be primarily composed of densely packed, unbranched filaments, together with spherical-, rod- and spiral-shaped cells, and microcrystals of calcite in a mucoid matrix . Molecular phylogenetic analysis of the community structure revealed approximately 12% of clones showed high similarity to autotrophic nitrite-oxidizing bacteria (Nitrospira moscoviensis) . The remainder of the clones exhibited a high proportion of phylogenetically novel sequence types . Chemical analysis of water samples revealed high levels of sulphate and nitrate together with significant nitrite . The community structure, the presence of nitrite in the water, and the apparent absence of aquatic macrofauna, suggest these microbial structures may represent biochemically novel, chemoautotrophic communities dependent on nitrite oxidation.

J Leukoc Biol, 2001 May, 69(5), 691 - 7
Participation of mammalian defensins and cathelicidins in anti-microbial immunity: receptors and activities of human defensins and cathelicidin (LL-37); Yang D et al.; Defensins and cathelicidins are the two major families of mammalian anti-microbial proteins . They contribute to host, innate, anti-microbial defense by disrupting the integrity of the bacterial cell membrane . However, several members of the mammalian anti-microbial proteins including defensins and cathelicidins have been shown recently to have chemotactic effects on host cells . Human neutrophil alpha-defensins are chemotactic for resting, naive CD45RA/CD4 T cells, CD8 T cells, and immature dendritic cells . Human beta-defensins are also chemotactic for immature dendritic cells but induce the migration of memory CD45RO/CD4 T cells . In contrast, cathelicidin/LL-37 is chemotactic for neutrophils, monocytes, and T cells but not for dendritic cells . Thus, these anti-microbial peptides have distinct, host-target cell spectra . The chemotactic activities of human beta-defensins and cathelicidin/LL-37 are mediated by human CC chemokine receptor 6 and formyl peptide receptor-like 1, respectively . The capacities of defensins and cathelicidins to mobilize various types of phagocytic leukocytes, immature dendritic cells, and lymphocytes, together with their other effects such as stimulating IL-8 production and mast cell degranulation, provide evidence for their participation in alerting, mobilizing, and amplifying innate and adaptive anti-microbial immunity of the host.

J Steroid Biochem Mol Biol, 2001 Apr, 77(1), 87 - 96
Microbial transformations of steroids--XII . Progesterone hydroxylation profiles are modulated by post-translational modification of an electron transfer protein in Streptomyces roseochromogenes; Berrie JR et al.; When Streptomyces roseochromogenes strain 10984 was incubated with exogenous progesterone for 25 h the major monohydroxylated metabolite, 16alpha-hydroxyprogesterone was produced in 3.6 fold excess to the minor metabolite 2beta,16alpha-dihydroxyprogesterone . In a reconstituted system containing highly purified progesterone 16alpha-hydroxylase cytochrome P-450, and electron transfer proteins ferredoxin-like redoxin (roseoredoxin) and redoxin reductase (roseoredoxin reductase), both metabolites were produced but in a 10:1 ratio . When S . roseochromogenes was pre-incubated for 8 h with 0.32 mM progesterone and the purified components of the hydroxylase system incubated as before, the ratio of 16alpha-hydroxyprogesterone to 2beta,16alpha-dihydroxyprogesterone produced decreased to 2.8:1, virtually identical to the ratio in whole cell transformations . Reconstitution assays containing all combinations of hydroxylase proteins purified from progesterone pre-incubated and control cells showed that the roseoredoxin was solely responsible for the observed changes in in vitro metabolite ratios . The fact that the lower 16alpha-hydroxyprogesterone to 2beta,16alpha-dihydroxyprogesterone ratio was also obtained when S . roseochromogenes was exposed to 0.335 mM cycloheximide for 8 h prior to the progesterone pre-incubation, pointed to post-translation modification of the roseoredoxin . Separation of two isoforms of roseoredoxin by isoelectric focusing supported this proposition.

J, Exp . Mar . Biol . Ecol. . 2001 Jun 1, 260(2), 133 - 153
Roles of larval supply and behavior in determining settlement of barnacles in a temperate mangrove forest; Satumanatpan S et al.; Recruitment is often a major influence on the spatial distribution of populations of benthic marine invertebrates, but the contributions of different components of recruitment are not well known, with the added complication that the relative importance of various life-history processes may be scale-dependent . Previously, we have shown that over a large scale across a mangrove (Avicennia marina) forest in southeastern Australia, settlement of the barnacle Elminius covertus explained its patterns of recruitment, which in turn explained the distribution of adults on mangrove pneumatophores . Post-settlement mortality had little influence on this pattern . In contrast, small-scale vertical distributions of adult barnacles along individual pneumatophores were determined by the pattern of recruitment, which differed from the pattern of settlement, so post-settlement mortality determined the vertical patterns of adults.In this study, we tested whether larval supply and/or settlement behavior influence the observed settlement patterns of E . covertus across a forest (from seaward to landward zones) . We also tested whether larval supply could explain the vertical settlement patterns along the pneumatophores . A pumping system was used to collect cypris larvae from seaward, mid and landward zones of a mangrove forest and an adjacent, unvegetated shore and from three heights above the sediment surface . We also used transplantation of wooden stakes bearing microbial films and barnacle recruits between horizontal zones of the forest to determine whether settlement was influenced by these films or recruits.Both cyprid supply and cyprid behavior were important factors in determining the patterns of settlement of E . covertus across the forest . Cyprid supply was a result of three-fold differences in immersion times of different (landward, mid and seaward) zones across the forest and a decrease in density of cyprids in the water column from the seaward zone of the forest to the landward sections . In the absence of mangroves immediately adjacent to the forest, there was no temporally consistent difference in cyprid density across the shore and even the differences in immersion time did not produce consistent differences in cyprid supply across the shore . Wooden substrata that had been immersed at seaward sections of the forest attracted consistently more settlers than substrata immersed initially at other sections of the forest and settlement could be induced beyond the normal distribution of adults of E . covertus by stakes transplanted from the seaward zone.The vertical settlement pattern could not be explained by the supply of cyprids, suggesting that larval behavior must determine the vertical settlement pattern.

Pediatr Dermatol, 2001 Mar-Apr, 18(2), 93 - 6
Skin barrier, hydration, and pH of the skin of infants under 2 years of age; Giusti F et al.; The goal of this study was to instrumentally evaluate the skin of healthy infants and to compare it to adult skin . A total of 70 infants, 45 girls and 25 boys, ages 8-24 months, and 30 healthy women were studied by means of transepidermal water loss (TEWL), capacitance, and pH measurements at two different skin sites, the volar forearm and the buttocks . No significant differences in TEWL were found between infants and adults, either on the buttocks or on the volar forearm . On the contrary, capacitance values were higher in infants . Their skin also appeared less acid than that of adults, with high statistical significance . No TEWL, capacitance, or pH variations were observed in infants according to sex and age . On the basis of the above data, the skin of infants 8-24 months of age shows functional signs of immaturity . This may lead to an increased permeability and a reduced capacity for defense against chemical and microbial aggression.

Water Res, 2001 Jun, 35(9), 2314 - 9
Fenton oxidation of ethanol-washed distillation-concentrated benzo(a)pyrene: reaction product identification and biodegradability; Lee BD et al.; After multiple ethanol washings followed by distillation, concentrated benzo(a)pyrene (B(a)P) in ethanol (approximately 85 mg L(-1)) was treated by Fenton oxidation, where > 99.8% of B(a)P was removed under a pseudo-first-order reaction . GC-MS and HPLC analysis identified B(a)P-1,6-, -3,6-, and -6,12-dione as Fenton oxidation products; all of which are known to have lower toxicity than B(a)P . Microbial resistance experiments demonstrated that B(a)P-1.6-, -3.6-, and -6,12-dione are more easily degraded than B(a)P . These results indicate that the proposed treatment can be effectively applied to remediate B(a)P-contaminated soil.

Int Immunopharmacol, 2001 Apr, 1(4), 677 - 87
Recombinant expression of human mannan-binding lectin; Vorup-Jensen T et al.; Mannan-binding lectin (MBL) constitutes an important part of the innate immune defence by effecting the deposition of complement on microbial surfaces . MBL deficiency is among the most common primary immunodeficiencies and is associated with recurrent infections and symptoms of poor immune complex clearance . Plasma-derived MBL has been used in reconstitution therapy but concerns over viral contamination and production capacity point to recombinant MBL (rMBL) as a future source of this protein for clinical use . Natural human MBL is an oligomer of up to 18 identical polypeptide chains . The synthesis of rMBL has been accomplished in several mammalian cell lines, however, the recombinant protein differed structurally from natural MBL . In this, study we compare rMBL produced in myeloma cells, Chinese hamster ovary (CHO) cells, human hepatocytes, and human embryonic kidney (HEK) cells . We report that rMBL structurally and functionally similar to natural MBL can be obtained through synthesis in the human embryonic kidney cells followed by selective carbohydrate affinity chromatography.

Prikl Biokhim Mikrobiol, 2001 Mar-Apr, 37(2), 247 - 52
{Electrooptical properties of soil nitrogen-fixing bacterium Azospirillum brasilense: effect of copper ions}; Ignatov OV et al.; The effects of copper ions on the uptake of some essential metals in the biomass and the electrooptical properties of cell suspensions of the nitrogen-fixing soil bacterium Azospirillum brasilense sp . 245 were studied . Copper cations were shown to be effectively taken up by the cell biomass from the culture medium . The addition of copper ions increased the rate of uptake of some other metals present in the culture medium . This was accompanied by changes in the electrooptical characteristics of cell suspension as measured within the orienting electric field frequency range of 10 to 10,000 kHz . The effects observed during short-term incubation of A . brasilense in the presence of copper cations were less significant than during long-term incubation . These results can be used for rapid screening of microbial cultures for enhanced efficiency of sorption and uptake of metals.

Prikl Biokhim Mikrobiol, 2001 Mar-Apr, 37(2), 175 - 80
{Degradation of mineral oils by a selected microbial association}; Muratovba AIu et al.; A series of microbial associations capable of degrading various petroleum oils, emulsols, and crude oil were obtained by selection during periodic or continuous cultivation . The formation of these associations and oil-product degradation occurred most efficiently during aerobic flow cultivation . Under these conditions, oils were degraded by 92% on average . The microbial degradation of a petroleum oil depended on its brand, concentration, emulsification, and aeration.

J Prosthet Dent, 2001 May, 85(5), 461 - 5
The influence of intracrevicular crown margins on gingival health: preliminary findings; Kancyper SG et al.; STATEMENT OF PROBLEM: The effect on gingival tissue of various crown materials in combination with different abutment biomaterials should be investigated . PURPOSE: This in vivo study determined the gingival health and subgingival levels of periodontal inflammation-associated bacteria adjacent to various crown and abutment material combinations . MATERIAL AND METHODS: . Patients in the study received 1 of 5 treatments: an all-ceramic crown luted to a natural tooth, a metal-ceramic (titanium) crown luted to natural tooth, a metal-ceramic (high noble alloy) crown luted to natural tooth, an all-ceramic crown luted to a titanium implant abutment, or a metal-ceramic (high noble alloy) crown luted to a titanium implant abutment . Plaque was collected at least 6 months after luting by paper point from the gingival sulcus of each crown and an adjacent unrestored (control) tooth . DNA probe analysis was performed to determine the levels of Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans . In addition, plaque, gingival redness, swelling, and bleeding scores were recorded with use of the California Dental Association scale . Statistical analysis was used to determine the effect of restoration/abutment type on levels of the bacterial species and clinical parameters pertaining to gingival health . RESULTS: None of the sulci sampled contained detectable levels of the 3 bacteria . Plaque levels and gingival redness, swelling, and bleeding scores were low . All treatment groups had similar soft tissue response as measured by gingival redness, swelling, and bleeding . Plaque scores from all-ceramic crown/implant abutment sites were higher than plaque scores from all-ceramic crown/natural tooth sites . However, differences between experimental and control sites within the same treatment group were not observed (P>.05) with any of the 4 clinical measures . CONCLUSION: In patients with suitable oral hygiene, tooth-supported and implant-supported crowns with intracrevicular margins were not predisposed to unfavorable gingival and microbial responses.

Res Vet Sci, 2001 Apr, 70(2), 169 - 73
Treatment of broiler litter with organic acids; Ivanov IE; Experiments for treatment of contaminated broiler litter with citric, tartaric and salicylic acids were performed . At days 2 and 6 after the treatment, pH values (using a pH-meter), the ammonia concentrations (titration with 0.1 N HCl) and the microbial cells counts were determined in both experimental and control specimens of litter . The cost of acidification of litter was also determined . Our studies showed that the treatment of the contaminated litter with 5 per cent citric acid, 4 per cent tartaric acid and 1.5 per cent salicylic acid created an acid medium with pH under 5.0 and thus reduced the microbial counts to 2.2 x 10(3)colony forming units per gram manure litter . The treatment reduced the content of ammonia in the litter and in the air under the hygienic limits, i.e . 25-50 ppm . The cost of acidification of litter with these organic acids amounted to 0.1 $ per bird and 1.5 $ per 15 birds on one square metre in a growth period of 50 days .

J Chromatogr A, 2001 Apr 13, 913(1-2), 365 - 70
Determination of sialic acids by liquid chromatography-mass spectrometry; Shaw CJ et al.; Sialic acids are widely found in nature as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers . Existing methods for determining these acids are long, tedious, and not specific . A simple, rapid, and sensitive method for determining the most commonly occurring acids, N-acetylneuraminic and N-glycolylneuraminic acid, using LC-MS is described . Standard solutions of the sialic acids with the internal standard, N-acetylneuraminic acid methyl ester, were quantitatively analyzed by positive ion electrospray ionization . Fetuin was used as a model glycoprotein and the hydrolysate was injected directly onto an ES Industries AquaSep 3 microm 150x4.6 mm column eluted with a 0.1% aqueous formic acid mobile phase at a flow-rate of 0.5 ml/min . Detection was achieved using the Finnigan Navigator MS system in the selected ion monitoring mode for the protonated molecular ions at m/z 310, 324, and 326 . The linearity over the dynamic range 10 to 1000 ng of sialic acids on-column had a correlation coefficient greater than 0.999 . The amount of sialic acids found in the fetuin hydrolysate was in agreement with values reported in the literature.

Oral Dis, 2000 Nov, 6(6), 335 - 50
Periodontal infections and cardiovascular disease--how strong is the association?
Armitage GC.
In the past decade there has been renewed interest in the old hypothesis that infections increase the risk of developing cardiovascular disease and stroke . There is now a convincing body of evidence that atherosclerosis has a major inflammatory component and is much more than the simple vascular accumulation of lipids . Infectious agents that have been linked to an increased risk of coronary heart disease (CHD) include Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpesviruses . The concept has emerged that each of these agents is an independent risk factor for CHD and that common chronic infections are important . In addition, periodontal infections have also been implicated as one of several factors contributing to the development of CHD . Evidence supporting a causative role of chronic infections in CHD is largely circumstantial . However, the evidence is sufficiently strong to warrant further examination of the possible link between chronic infections and CHD . In this review the lines of evidence for a causative role of C . pneumoniae in the development of CHD are summarized and contrasted with the lines of evidence suggesting a periodontal infection--CHD association . If common or widespread chronic infections are truly important risk factors for CHD, it is unlikely that a single infection will be shown to be causative . It is likely that the entire microbial burden of the patient from several simultaneous chronic infections is more important (e.g., H . pylori-caused gastric ulcers + C . pneumoniae-caused bronchitis + periodontitis) . Increased cooperation between cardiologists and periodontists will be required to determine if, and what, combinations of common chronic infections are important in the pathogenesis of CHD and stroke.

Aust Dent J, 2001 Mar, 46(1), 2 - 12
Periodontal manifestations of systemic disease; Kinane DF et al.; Periodontitis is a chronic bacterial infection of the supporting structures of the teeth . The host response to infection is an important factor in determining the extent and severity of periodontal disease . Systemic factors modify periodontitis principally through their effects on the normal immune and inflammatory mechanisms . Several conditions may give rise to an increased prevalence, incidence or severity of gingivitis and periodontitis . The effects of a significant number of systemic diseases upon periodontitis are unclear and often it is difficult to causally link such diseases to periodontitis . In many cases the literature is insufficient to make definite statements on links between certain systemic factors and periodontitis and for several conditions only case reports exist whereas in other areas an extensive literature is present . A reduction in number or function of polymorphonuclear leukocytes (PMNs) can result in an increased rate and severity of periodontal destruction . Medications such as phenytoin, nifedipine, and cyclosporin predispose to gingival overgrowth in response to plaque and changes in hormone levels may increase severity of plaque-induced gingival inflammation . Immuno-suppressive drug therapy and any disease resulting in suppression of the normal inflammatory and immune mechanisms (such as HIV infection) may predispose the individual to periodontal destruction . There is convincing evidence that smoking has a detrimental effect on periodontal health . The histiocytoses diseases may present as necrotizing ulcerative periodontitis and numerous genetic polymorphisms relevant to inflammatory and immune processes are being evaluated as modifying factors in periodontal disease . Periodontitis severity and prevalence are increased in diabetics and worse in poorly controlled diabetics . Periodontitis may exacerbate diabetes by decreasing glycaemic control . This indicates a degree of synergism between the two diseases . The relative risk of cardiovascular disease is doubled in subjects with periodontal disease . Periodontal and cardiovascular disease share many common risk and socio-economic factors, particularly smoking, which is a powerful risk factor for both diseases . The actual underlying aetiology of both diseases is complex as are the potential mechanisms whereby the diseases may be causally linked . It is thought that the chronic inflammatory and microbial burden in periodontal disease may predispose to cardiovascular disease in ways proposed for other infections such as with Chlamydia pneumoniae . To move from the current association status of both diseases to causality requires much additional evidence . Determining the role a systemic disease plays in the pathogenesis of periodontal disease is very difficult as several obstacles affect the design of the necessary studies . Control groups need to be carefully matched in respect of age, gender, oral hygiene and socio-economic status . Many studies, particularly before the aetiological importance of dental plaque was recognised, failed to include such controls . Longitudinal studies spanning several years are preferable in individuals both with and without systemic disease, due to the time period in which periodontitis will develop.

J Chromatogr A, 2001 Apr 13, 913(1-2), 365 - 70
Determination of sialic acids by liquid chromatography-mass spectrometry; Shaw CJ et al.; Sialic acids are widely found in nature as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers . Existing methods for determining these acids are long, tedious, and not specific . A simple, rapid, and sensitive method for determining the most commonly occurring acids, N-acetylneuraminic and N-glycolylneuraminic acid, using LC-MS is described . Standard solutions of the sialic acids with the internal standard, N-acetylneuraminic acid methyl ester, were quantitatively analyzed by positive ion electrospray ionization . Fetuin was used as a model glycoprotein and the hydrolysate was injected directly onto an ES Industries AquaSep 3 microm 150x4.6 mm column eluted with a 0.1% aqueous formic acid mobile phase at a flow-rate of 0.5 ml/min . Detection was achieved using the Finnigan Navigator MS system in the selected ion monitoring mode for the protonated molecular ions at m/z 310, 324, and 326 . The linearity over the dynamic range 10 to 1000 ng of sialic acids on-column had a correlation coefficient greater than 0.999 . The amount of sialic acids found in the fetuin hydrolysate was in agreement with values reported in the literature.

Rev Pneumol Clin, 2001 Apr, 57(2), 91 - 8
{Prevention of nosocomial infection during nebulization and spirometry}; Dautzenberg B; The nebulizer, designed for the delivery of important quantities of drugs to the bronchi and lungs can also deliver microbial deposits . The risk can be one of recontaminating a patient with his/her own bacteria, contaminating other individuals (other patients or staff during a nebulization session from a patient infected by an ordinary germ or tuberculosis), or transmission via unclean equipment, contaminated water or medicines . The use of single-dose drug preparations, single-patient devices, sterile water, and rigorous applications of the protocols can considerably reduce the risk . Although respiratory function tests are done with expensive equipment that has to be reused, sometimes by a large number of patients in the same day, cases of cross-contamination are exceptional . Closed spirometers are however a risk . The use of single-use filters can save money and time needed to clean all the device parts used in connection with the inspiratory circuit during respiratory tests . In intensive care units, the passage of spirometers from one patient to the next without a cleaning procedure is a situation of risk . In all these situations, implementation of cleaning protocols allows to reduce this risk, although zero risk cannot be achieved especially for recontamination of patients by their own bacteria during nebulization.

J Dairy Sci, 2001 Apr, 84(4), 784 - 91
Effect of various dairy packaging materials on the shelf life and flavor of ultrapasteurized milk; Simon M et al.; Raw milk from three different dairies (each a separate trial: 1, 2, and 3) was standardized to 2% fat and processed at 140.6, 129.4, 118.3, and 107.2 degrees C (temperatures 1, 2, 3, and 4, respectively) for 2 s and packaged into six different packaging boards, {standard (A) milk boards with standard seam, juice boards with standard (B) and J-bottom (D) seams, barrier boards with standard (C) and J-bottom (E) seams and foil (F) boards with J-bottom seam}, resulting in 24 different treatments . Standard plate count (SPC) was used to test for microbial quality, and taste panels were employed for flavor acceptability and difference in the milk stored at 6.7 degrees C at 1, 2, 3, 5, 10, and 15 wk . Lipolysis was measured by standard procedures for acid degree value (ADV) of milk . Statistical analysis of taste panel data showed that the flavor of 14 milk samples deteriorated over time . The flavor of UP milk packaged in standard (A) and juice (B and D) boards deteriorated at a faster rate than UP milk packaged in barrier (C and E) and foil (F) boards . At wk 6, a slightly hammy or cardboardy flavor was detected for milk packaged in boards with standard seams (A, B, and C) and a slightly cooked flavor was detected for milk packaged in barrier and foil boards with J-bottom (E and F) seams . The hammy or cardboardy flavor intensified with storage time, and all of the cooked flavor dissipated at wk 10 . Milk processed at 118.3 and 129.4 degrees C maintained the lowest bacterial growth rates, and milk processed at 107.2 degrees C had the highest bacterial growth rates during 15 storage wk . More than 87% of milk processed at 118.3, 129.4, and 140.6 degrees C maintained acceptable level of bacterial counts at wk 15 . The extent of lipolysis showed that ADV of milk increased with storage time . The ranges of ADV for trials 1, 2, and 3 were 0.76 to 0.85 (from 12 to 22 wk), 0.39 to 0.51 (from 6 to 16 wk), and 0.53 to 0.60 (from 6 to 16 wk), respectively.

J Dairy Sci, 2001 Apr, 84(4), 767 - 73
Effect of various dairy packaging materials on the shelf life and flavor of pasteurized milk; Simon M et al.; Milk from three different dairies (each a separate trial: 1, 2, and 3) was standardized to 2% fat and pasteurized at 92.2, 84.0, and 76.4 degrees C (temperatures 1, 2, and 3, respectively) for 25 s and packaged into six different packaging boards, {standard (A) milk boards with standard seam; juice boards with standard (B) and J-bottom (D) seams; barrier boards with standard (C) and J-bottom (E) seams; and foil (F) boards with J-bottom seam}, resulting in 18 different treatments . Standard plate count (SPC) was used to test for microbial quality, and taste a panel was employed for flavor acceptability and difference on the milk stored at 6.7 degrees C at 1, 2, 3, and 4 wk . Statistical analysis of taste panel data showed that the flavor of milk samples A2, B2, and D2 deteriorated faster than the blind control (freshly high temperature, short time pasteurized low fat milk processed at 80.6 degrees C for 25 s) . The flavor of milk packaged in standard (A) and juice (B and D) boards deteriorated at a faster rate than milk packaged in barrier (C and E) and foil (F) boards . Microbial counts showed that milk samples stored at 6.7 degrees C in trials 2 and 3 produced high SPC at wk 3 (ranges of bacteria in cfu/ml for trial 2: 9.9 x 10(1)-1.8 x 10(6) and trial 3: 2.5 x 10(5)-5.5 x 10(8)) . In trial 1, high SPC began at wk 4 (9.9 x 10(1)-5.5 x 10(5) cfu/ml) . Milk processed at 76.4 degrees C had the lowest bacterial growth rate, and milk processed at 84.0 degrees C had the highest bacterial growth rate . Different boards had no effects (P > 0.05) on the bacterial growth rates . It appeared that the lower the SPC of the raw milk, the slower the bacterial growth rate after 2 wk of storage . Milk samples stored at 1.7 degrees C maintained low SPC at wk 4, with counts of 0 to 40 cfu/ml for trial 2 and 0 to 200 cfu/ml for trial 3.

Environ Sci Technol, 2001 Jan 1, 35(1), 133 - 41
Uncertainties of Monod kinetic parameters nonlinearly estimated from batch experiments; Liu C et al.; Monod kinetic parameters (Ks, micromax, and Y) that are estimated from batch experimental data can have large uncertainties due to linear correlations between them . The degree of correlation and the resulting uncertainties of the Monod parameters are functions of the initial experimental conditions, the values of the parameters, the type and magnitude of measurement errors, and the sampling number . Careful manipulation of experimental conditions can reduce the correlations between Monod parameters allowing for the estimation of Monod kinetic parameters with the lowest degree of uncertainty . By dimensionless analysis, the correlation and relative standard deviations of Monod parameters were found to be functions of a few dimensionless variables involving the initial substrate (S0) and cell (X0) concentrations . Quantitative relationships were analyzed between the dimensionless variables and the correlation and the uncertainties of the Monod parameters . This analysis allowed for identification of the optimal experimental conditions for estimating Monod parameters under both no growth and growth conditions coupled with two kinds of measurement errors: those with constant absolute standard deviation and those with constant relative standard deviation . Examples involving the microbial reduction of iron(III) as an electron acceptor are used to illustrate the application of the developed technique.

Environ Pollut, 2001, 113(1), 19 - 26
A microbial biosensor to predict bioavailable nickel in soil and its transfer to plants; Tibazarwa C et al.; Ralstonia eutropha strain AE2515 was constructed and optimised to serve as a whole-cell biosensor for the detection of bioavailable concentrations of Ni2+ and Co2+ in soil samples . Strain AE2515 is a Ralstonia eutropha CH34 derivative containing pMOL1550, in which the cnrYXH regulatory genes are transcriptionally fused to the bioluminescent luxCDABE reporter system . Strain AE2515 was standardised for its specific responses to Co2+ and Ni2+ . The detection limits for AE2515 were 0.1 microM Ni2+ and 9 microM Co2+, respectively . The signal to noise (S/N) bioluminescence response and the metal cation concentration could be linearly correlated: for Ni2+ this was applicable within the range 0.1-60 microM, and between 9 and 400 microM for Co2+ . The AE2515 biosensor strain was found to be highly selective for nickel and cobalt: no induction was observed with Zn(II), Cd(II), Mn(II), Cu(III) and Cr(VI) . In mixed metal solutions, the bioluminescent response always corresponded to the nickel concentrations . Only in the presence of high concentrations of Co2+ (2 mM), the sensitivity to nickel was reduced due to metal toxicity . AE2515 was used to quantify the metal bioavailability in various nickel-enriched soils, which had been treated with additives for in situ metal immobilisation . The data obtained with strain AE2515 confirmed that the bioavailability of nickel was greatly reduced following the treatment of the soils with the additives beringite and steel shots . Furthermore, the data were found to correlate linearly with those on the biological accumulation of Ni2+ in specific parts of important agricultural crops, such as maize and potato . Therefore, the test can be used to assess the potential transfer of nickel to organisms of higher trophic levels, in this case maize and potato plants grown on nickel-enriched soils, and the potential risk of transfer of these elements to the food chain.

Environ Sci Technol, 2001 Feb 1, 35(3), 455 - 61
Fate and origin of 1,2-dichloropropane in an unconfined shallow aquifer; Tesoriero AJ et al.; A shallow aquifer with different redox zones overlain by intensive agricultural activity was monitored for the occurrence of 1,2-dichloropropane (DCP) to assess the fate and origin of this pollutant . DCP was detected more frequently in groundwater samples collected in aerobic and nitrate-reducing zones than those collected from iron-reducing zones . Simulated DCP concentrations for groundwater entering an iron-reducing zone were calculated from a fate and transport model that included dispersion, sorption, and hydrolysis but not degradation . Simulated concentrations were well in excess of measured values, suggesting that microbial degradation occurred in the iron-reducing zone . Microcosm experiments were conducted using aquifer samples collected from iron-reducing and aerobic zones to evaluate the potential for microbial degradation of DCP and to explain field observations . Hydrogenolysis of DCP and production of monochlorinated propanes in microcosm experiments occurred only with aquifer materials collected from the iron-reducing zone, and no dechlorination was observed in microcosms established with aquifer materials collected from the aerobic zones . Careful analyses of the DCP/1,2,2-trichloropropane ratios in groundwater indicated that older fumigant formulations were responsible for the high levels of DCP present in this aquifer.

Environ Toxicol Chem, 2001 Jan, 20(1), 205 - 12
Congener-specific model for polychlorinated biphenyl effects on otter (Lutra lutra) and associated sediment quality criteria; Traas TP et al.; A model for risk assessment was built for simultaneous, congener-specific PCB bioaccumulation from sediment to fish to otters (Lutra lutra) . Toxic equivalence factors (TEFs) were used to sum individual congeners in otters to a toxic equivalent concentration (TEQ) relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin . Microbial dechlorination and burial in sediments and bioaccumulation are modeled to predict time trends of PCB concentrations in otters . Effects of accumulated PCBs on otters were assessed for vitamin A metabolism and reproduction, taking model uncertainty into account . Three locations in The Netherlands were modeled with PCB levels in sediment of 1 to 171 pg TEQ/g organic carbon (OC) . Almost 100% reduction in litter size was predicted for the most polluted area in 1996 . Due to large associated uncertainty, a period of 25 to 80 years may be needed for recovery of otter vitamin A levels and litter size at this site . Calculated median sediment quality criteria (SQC) range between 1 and 12 pg TEQ/g OC, depending on the chosen effect criterion . Uncertainty in calculated effects and SQCs is substantial and is mainly caused by uncertainty in PCB congener 126 accumulation.

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