Microbial

Ann N Y Acad Sci, 1999 Jun 30, 878, 404 - 12
C-telopeptide pyridinoline cross-links . Sensitive indicators of periodontal tissue destruction; Giannobile WV; C-telopeptides and related pyridinoline cross-links of bone Type I collagen are sensitive markers of bone resorption in osteolytic diseases such as osteoporosis and osteoarthritis . We have studied the release of C-telopeptide pyridinoline crosslinks of Type I collagen as measures of bone destruction in periodontal disease . Studies in preclinical animal models and humans have demonstrated the relationship between radiographic bone loss and crevicular fluid C-telopeptide levels . We have recently found that C-telopeptide levels correlate strongly with microbial pathogens associated with periodontitis and around endosseous dental implants . Host-modulation of bone-related collagen breakdown has been shown by studies in humans demonstrating that MMP inhibition blocks tissue destruction and release of C-telopeptides in patients with active periodontal disease.

Arch Microbiol, 1999 Aug, 172(2), 83 - 94
Specific detection of different phylogenetic groups of chemocline bacteria based on PCR and denaturing gradient gel electrophoresis of 16S rRNA gene fragments; Overmann J et al.; Specific amplification of 16S rRNA gene fragments in combination with denaturing gradient gel electrophoresis (DGGE) was used to generate fingerprints of Chromatiaceae, green sulfur bacteria, Desulfovibrionaceae, and beta-Proteobacteria . Sequencing of the gene fragments confirmed that each primer pair was highly specific for the respective phylogenetic group . Applying the new primer sets, the bacterial diversity in the chemoclines of a eutrophic freshwater lake, a saline meromictic lake, and a laminated marine sediment was investigated . Compared to a conventional bacterial primer pair, a higher number of discrete DGGE bands was generated using our specific primer pairs . With one exception, all 15 bands tested yielded reliable 16S rRNA gene sequences . The highest diversity was found within the chemocline microbial community of the eutrophic freshwater lake . Sequence comparison revealed that the six sequences of Chromatiaceae and green sulfur bacteria detected in this habitat all represent distinct and previously unknown phylotypes . The lowest diversity of phylotypes was detected in the chemocline of the meromictic saline lake, which yielded only one sequence each of the Chromatiaceae, beta-2-Proteobacteria, and Desulfovibrionaceae, and no sequences of green sulfur bacteria . The newly developed primer sets are useful for the detection of previously unknown phylotypes, for the comparison of the microbial diversity between different natural habitats, and especially for the rapid monitoring of enrichments of unknown bacterial species.

J Immunol, 1999 Aug 1, 163(3), 1570 - 6
Generation of nitric oxide by the inducible nitric oxide synthase protects gamma delta T cells from Mycobacterium tuberculosis-induced apoptosis; Sciorati C et al.; Gamma delta T cells are early recruited into mycobacterial lesions . Upon microbial Ag recognition, gamma delta cells secrete cytokines and chemokines and undergo apoptosis via CD95/CD95 ligand (CD95L) interaction, possibly influencing the outcome of infection and the characteristics of the disease . In this paper we show that activated phagocytes acquire, upon challenge with Mycobacterium tuberculosis, the ability to inhibit M . tuberculosis-induced gamma delta cell apoptosis . Apoptosis protection was due to NO because it correlated with NO synthase (NOS)-2 induction and activity in scavenger cells and was abrogated by NOS inhibitors . Furthermore, the NO donor S-nitrosoacetylpenicillamine mimicked the effect of enzyme induction . NO left unaffected the expression of CD95 and CD95L, suggesting interference with an event ensuing CD95/CD95L interaction . NO was found to interfere with the intracellular accumulation of ceramide and the activation of caspases, which were involved in gamma delta T cells apoptosis after M . tuberculosis recognition . We propose that NO generated by infected macrophages determines the life span and therefore the function of lymphocytes at the infection site, thus linking innate and adaptive immunity.

Med Parazitol (Mosk), 1999 Jan-Mar, (1), 55 - 8
{The survival of the causative agent of plaque in the long-tailed suslik from a Tuva natural focus in wintertime}; Maevskii MP et al.; The survival of the causative agent of plague in the long-tailed souslik in the Tuva natural focus in winter was experimentally studied . They were made in a special bunker laboratory just in the focus . The experimental conditions were close to the hygrothermal parameters of a long-tailed souslik's burrow . Inoculation and placement of the animals and fleas into the bunker were accomplished in the September to early October . The rodents and ectoparasites were examined after their hibernation in the late April to early May of the following year . The duration of the experiment was 7.5 months . It has been found that the long-tailed souslik can be infected with the causative agent of plague before hibernation through transmission . There were no cases of plague microbial infection through the bite of fleas in sousliks following hibernation . Low infection rates of the fleas hibernating with their host were notified . The causative agent was found to survive in the mummified carcasses of sousliks for 7.5 months (the follow-up period).

Plant Mol Biol, 1999 May, 40(2), 323 - 32
A novel E-type endo-beta-1,4-glucanase with a putative cellulose-binding domain is highly expressed in ripening strawberry fruits; Trainotti L et al.; Two full-length cDNA clones (faEG1 and faEG3, respectively) have been isolated by screening a cDNA library representing transcripts from red strawberry fruits . Southern blot analysis of genomic DNA suggests that the strawberry endo-beta-1,4-glucanases (EGases) are encoded by a multigene family . The cognate genes are predominantly expressed during the ripening process proper, although, in the case of faEG3, some expression has also been observed in large green fruits and, at low amounts, in young vegetative green tissues . In agreement with other ripening-related genes in strawberry, also the expression of faEG1 and faEG3 is down-regulated by treatment with an auxin analogue (1-naphthaleneacetic acid, NAA) . Differences in temporal expression of the two EGase genes in fruits are not accompanied by differences in spatial expression . The pattern of expression and the sequence characteristics of the two polypeptides suggest that the two strawberry EGases operate in a synergistic and coordinate manner . The protein encoded by faEG1 looks like one of the usual higher-plant EGases (average molecular mass of 54 kDa), while the protein encoded by faEG3 has a greater deduced molecular mass (about 68 kDa) due to the presence of an extra peptide of about 130 amino acids at the C-terminus . Such unusual peptide shows some features also found in microbial cellulases and contains a putative cellulose-binding domain . We propose that the faEG3-encoded EGase might especially hydrolyse the xyloglucans coating the cellulose microfibrils, thus rendering the cell wall more susceptible to the subsequent hydrolytic activity of the faEG1-encoded EGase.

Croat Med J, 1999 Sep, 40(3), 392 - 7
Histological analysis and ancient DNA amplification of human bone remains found in caius iulius polybius house in pompeii; Cipollaro M et al.; Thirteen skeletons found in the Caius Iulius Polybius house, which has been the object of intensive study since its discovery in Pompeii 250 years ago, have provided an opportunity to study either bone diagenesis by histological investigation or ancient DNA by polymerase chain reaction analysis . DNA analysis was done by amplifying both X- and Y-chromosomes amelogenin loci and Y-specific alphoid repeat locus . The von Willebrand factor (vWF) microsatellite locus on chromosome 12 was also analyzed for personal identification in two individuals showing alleles with 10/11 and 12/12 TCTA repeats, respectively . Technical problems were the scarcity of DNA content from osteocytes, DNA molecule fragmentation, microbial contamination which change bone structure, contaminating human DNA which results from mishandling, and frequent presence of Taq DNA polymerase inhibiting molecules like polyphenols and heavy metals . The results suggest that the remains contain endogenous human DNA that can be amplified and analyzed . The amplifiability of DNA corresponds to the bone preservation and dynamics of the burial conditions subsequent to the 79 A.D . eruption.

JAMA, 1999 Jul 14, 282(2), 175 - 81
The rational clinical examination . Does this adult patient have acute meningitis?
Attia J, Hatala R, Cook DJ, Wong JG.
CONTEXT: Early clinical recognition of meningitis is imperative to allow clinicians to efficiently complete further tests and initiate appropriate therapy . OBJECTIVE: To review the accuracy and precision of the clinical examination in the diagnosis of adult meningitis . DATA SOURCES: A comprehensive review of English- and French-language literature was conducted by searching MEDLINE for 1966 to July 1997, using a structured search strategy . Additional references were identified by reviewing reference lists of pertinent articles . STUDY SELECTION: The search yielded 139 potentially relevant studies, which were reviewed by the first author . Studies were included if they described the clinical examination in the diagnosis of objectively confirmed bacterial or viral meningitis . Studies were excluded if they enrolled predominantly children or immunocompromised adults or focused only on metastatic meningitis or meningitis of a single microbial origin . A total of 10 studies met the criteria and were included in the analysis . DATA EXTRACTION: Validity of the studies was assessed by a critical appraisal of several components of the study design . These components included an assessment of the reference standard used to diagnose meningitis (lumbar puncture or autopsy), the completeness of patient ascertainment, and whether the clinical examination was described in sufficient detail to be reproducible . DATA SYNTHESIS: Individual items of the clinical history have low accuracy for the diagnosis of meningitis in adults (pooled sensitivity for headache, 50% {95% confidence interval {CI}, 32%-68%}; for nausea/vomiting, 30% {95% CI, 22%-38%}) . On physical examination, the absence of fever, neck stiffness, and altered mental status effectively eliminates meningitis (sensitivity, 99%-100% for the presence of 1 of these findings) . Of the classic signs of meningeal irritation, only 1 study has assessed Kernig sign; no studies subsequent to the original report have evaluated Brudzinski sign . Among patients with fever and headache, jolt accentuation of headache is a useful adjunctive maneuver, with a sensitivity of 100%, specificity of 54%, positive likelihood ratio of 2.2, and negative likelihood ratio of 0 for the diagnosis of meningitis . CONCLUSIONS: Among adults with a clinical presentation that is low risk for meningitis, the clinical examination aids in excluding the diagnosis . However, given the seriousness of this infection, clinicians frequently need to proceed directly to lumbar puncture in high-risk patients . Many of the signs and symptoms of meningitis have been inadequately studied, and further prospective research is needed.

Eur J Biochem, 1999 Jun, 262(3), 915 - 23
The inhibitory properties and primary structure of a novel serine proteinase inhibitor from the fruiting body of the basidiomycete, Lentinus edodes; Odani S et al.; A novel proteinase inhibitor, Lentinus proteinase inhibitor, has been purified from the fruiting bodies of the edible mushroom, Lentinus edodes, by buffer extraction and affinity chromatography on immobilized anhydrotrypsin . The protein simultaneously inhibits bovine beta-trypsin and alpha-chymotrypsin at independent sites, with apparent dissociation constants of 3.5 x 10(-10) M and 4 x 10(-8) M, respectively . The purified protein is eluted as two well-separated peaks on reversed-phase HPLC, one of which is inhibitory-active and the other inactive, and they are interconvertible under folding/unfolding conditions . Among the mammalian and microbial serine proteinases examined, including human enzymes of blood coagulation and fibrinolysis, activated factor XI was inhibited by the Lentinus proteinase inhibitor . Chemical modification studies suggest involvement of one or more arginine residues in the inhibition of trypsin . The complete primary structure composed of 142 amino acids with an acetylated N-terminus was determined by protein analysis . The theoretical molecular mass (15999.2) from the sequence is close to the experimental value of 15999.61 +/- 0.61 determined by mass spectrometry . Although there are no apparently homologous proteinase inhibitors in the protein database, there is a rather striking similarity to the propeptide segment of a microbial serine proteinase, as well as to the N-terminal region of the mature enzyme.

Curr Opin Rheumatol, 1999 Jul, 11(4), 251 - 6
Psoriatic arthritis and the spectrum of syndromes related to the SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome; Winchester R; During the past year, the increasing use of nuclear magnetic resonance imaging techniques, with their ability to delineate cartilage and ligamentous structures and to identify edema, are providing a radical improvement in ascertainment of musculoskeletal abnormalities, although their significance remains incompletely delineated . A second theme has come from the study of spondyloarthropathies in different ethnic groups and societal environments, revealing that the Northern European and North American form of the disease, with its powerful association with HLA-B27, is little evident in the rest of the world's population and that different susceptibility genes and environmental factors operate in other regions and peoples . Related to this theme is the compelling evidence of the marked influence of HIV infection on the development of spondyloarthropathies in Africa . Two areas of immune recognition are discussed as examples of emerging fields that may provide useful paradigms for the experimental approach to mechanisms in psoriatic arthritis . One of these is the three-cell model of CD8 T-cell interaction, in which a dendritic cell presents a peptide from an immunogenic protein to both a CD4 and CD8 T-cell clone, providing a cognitive interaction that disrupts tolerance and results in the expansion of the cytotoxic T-cell clone . In this respect, the combination of an activated dendritic cell, together with enhanced availability of arthritogenic microbial antigens caused by microbial persistence, are interesting candidates to explore as the basis of the HIV-associated rheumatic diseases . The second area of immune recognition is the growing understanding of the outline of the solution to the problem of the association of a spondyloarthropathy with several

J Ophthalmic Nurs Technol, 1999 Mar-Apr, 18(2), 50 - 9; quiz 74-5
Practical ophthalmic microbiology; Levine J et al.; Infection is commonly encountered in everyday ophthalmic practice . It is of great importance that all ophthalmic personnel are familiar with the basic etiologies of these infections, and the basic techniques which are used in diagnosis . When evaluating a patient with possible infection, it is often of great help to be familiar with the normal microbial flora of the human body . This normal flora has been detailed in the article . The assumption is that knowledge of a patient's flora can help guide decisions about the possible etiologies of an infection . When presented with an obvious ocular infection, health care personnel should review the "usual suspects"--that is, the common etiologies for each type of infection . The key to combating ocular infections lies in accurate treatment of the presumed infectious agent . Therefore, the techniques and steps used in the identification of the etiology of an infection should be known to all ophthalmic personnel . The proper sterile techniques of obtaining a specimen from a suspected corneal ulcer or conjunctivitis and the plating of the specimen on specific agar for identification are essential to everyday practice (Figure 8) . Patients who will undergo surgery, regardless of the type, are being placed at a special risk for infection . These post-operative infections can destroy the work of the most careful and exact surgical technique . It is an essential part of the procedure that the patient be protected as best they can from subsequent infection . The techniques to reduce the risk of post-operative infection have been detailed above . Proper preparation of a sterile field, sterile draping, and perioperative antibiotics can reduce the chance of a subsequent infection . It is important that these basic steps of care be properly provided to help insure successful surgical outcomes and excellence in health care.

Am J Physiol, 1999 Jul, 277(1 Pt 1), G1 - 5
Mucosal immunity and inflammation . III . The mucosal antigen barrier: cross talk with mucosal cytokines; Perdue MH; We have known for many years that mucosal responses to antigens are regulated by immune cells and their molecular signals . More recently, it has become clear that epithelial cells also synthesize and secrete chemokines and cytokines . A sophisticated system of bidirectional cytokine signals is responsible for immune activation in the case of enteropathogens vs . immune suppression to food and commensal microbial antigens . A key factor in determining antigen handling is the route taken by antigens across the epithelial barrier . Cytokines and other mucosal messenger molecules play a critical role in the regulation of transepithelial antigen transport.

Rapid Commun Mass Spectrom, 1999 Jul, 13(13), 1311 - 1314
Carbon stable isotopes reveal complex trophic interactions in lake plankton; Grey J et al.; The lower trophic linkages in lake plankton food webs are generally described as relatively simple, even accounting for the additional complexity of potential 'microbial looping' . Crustacean zooplankton are frequently amalgamated into one trophic functional group as grazers of autotrophic production . The carbon stable isotope ratios for separated zooplankton species, particulate organic matter (POM) and phytoplankton from a number of lakes in Finland and the UK were analysed . These revealed greater complexity in trophic interactions than would otherwise be observed if the zooplankton had been represented by a mixed sample . Grazing zooplankton were usually depleted in (13)C relative to the bulk POM on which they might feed, with (13)C deviating by up to 17 per thousand There were no consistent differences between (13)C values for copepods and cladocerans . Predatory cladocerans were generally enriched by greater than 1 per thousand compared to their putative prey . We suggest that care in separating the zooplankton species for stable isotope analysis may expose otherwise undetected sources of carbon and facilitate unravelling trophic links further up the food web .

Rapid Commun Mass Spectrom, 1999, 13(13), 1291 - 4
Natural 13C abundance: a tool to trace the incorporation of dung-derived carbon into soil particle-size fractions; Amelung W et al.; During the decay of 13C enriched dung patches, the; delta 13C signal of surface soil (1-5 cm) increased with a temporary maximum after 42 d . To understand the underlying processes, we investigated the incorporation of dung-derived C into soil particle-size fractions . Dung, collected from beef steers fed on maize (delta 13C = -15.36/1000) or ryegrass (delta 13C = -25.67/1000), was applied in circular patches to a C3 pasture at North Wyke, UK . Triplicates were sampled from surface soil (1-5 cm) at 14, 28, 42, and 70 d after application, pooled, separated into fine (< 0.2 micron) and coarse clay (0.2-2 microns), silt plus fine sand (2-250 microns), and coarse sand (250-2000 microns), and analyzed for total C, N, and delta 13C . As particle-size diameter decreased, the C/N ratios decreased and delta 13C values increased at all plots due to increasing microbial alteration of soil organic matter . After dung application, ca . 60% of dung-derived C in soil was recovered in the 0.2-250 microns fractions during the whole experiment . The proportion of dung-derived C in the fine clay peaked 42 d after dung application, coinciding with the delta 13C maximum in the bulk soil and the maximum leaching rate measured in lysimeters at this time in another study at the same sites . The percentage of dung-derived C as particulate C in the coarse sand fraction increased until the end of the experiment . We conclude that incorporation of C into soil from decomposing dung patches involved both temporary sorption of leached dung C to < 0.2 micron fractions and continuous accumulation of particulate C (> 250 microns).

Rapid Commun Mass Spectrom, 1999 Jul, 13(13), 1284 - 1290
Isotopic ((13)C) fractionation during plant residue decomposition and its implications for soil organic matter studies; Schweizer M et al.; Carbon isotopic fractionations in plant materials and those occurring during decomposition have direct implications in studies of short-and longer-term soil organic matter dynamics . Thus the products of decomposition, the evolved CO(2) and the newly formed soil organic matter, may vary in their (13)C signature from that of the original plant material . To evaluate the importance of such fractionation processes, the variations in (13)C signatures between and within plant parts of a tropical grass (Brachiaria humidicola) and tropical legume (Desmodium ovalifolium) were measured and the changes in (13)C content (signatures) during decomposition were monitored over a period of four months . As expected the grass materials were less depleted in (13)C (-11.4 to -11.9 per thousand) than those of the legume (-27.3 to -25.8 per thousand) . Root materials of the legume were less (1.5 per thousand) depleted in (13)C compared with the leaves . Plant lignin-C was strongly depleted in (13)C compared with the bulk material by up to 2.5 per thousand in the legume and up to 4.7 per thousand in the grass . Plant materials were subsequently incubated in a sand/nutrient-solution/microbial inoculum mixture . The respiration product CO(2) was trapped in NaOH and precipitated as CaCO(3), suitable for analysis using an automated C/N analyser coupled to an isotope ratio mass spectrometer . Significant depletion in (13)C of the evolved CO(2) was observed during the initial stages of decomposition probably as a result of microbial fractionation as it was not associated with the (13)C signatures of the measured more decomposable fractions (non-acid detergent fibre and cellulose) . While the cumulative CO(2)-(13)C signatures of legume materials became slightly enriched with ongoing decomposition, the CO(2)-C of the grass materials remained depleted in (13)C . Associated isotopic fractionation correction factors for source identification of CO(2-)C varied with time and suggested errors of 2-19% in the estimation of the plant-derived C at 119 days of incubation in a soil of an intermediate (-20.0 per thousand) (13)C signature . Analysis of the residual material after 119 days of incubation showed little or no change in the (13)C signature partly due to the incomplete decomposition at the time of harvesting .

Glycobiology, 1999 Aug, 9(8), 747 - 55
Evolutionary considerations in relating oligosaccharide diversity to biological function; Gagneux P et al.; The oligosaccharide chains (glycans) attached to cell surface and extracellular proteins and lipids are known to mediate many important biological roles . However, for many glycans, there are still no evident functions that are of obvious benefit to the organism that synthesizes them . There is also no clear explanation for the extreme complexity and diversity of glycans that can be found on a given glycoconjugate or cell type . Based on the limited information available about the scope and distribution of this diversity among taxonomic groups, it is difficult to see clear trends or patterns consistent with different evolutionary lineages . It appears that closely related species may not necessarily share close similarities in their glycan diversity, and that more derived species may have simpler as well as more complex structures . Intraspecies diversity can also be quite extensive, often without obvious functional relevance . We suggest one general explanation for these observations, that glycan diversification in complex multicellular organisms is driven by evolutionary selection pressures of both endogenous and exogenous origin . We argue that exogenous selection pressures mediated by viral and microbial pathogens and parasites that recognize glycans have played a more prominent role, favoring intra- and interspecies diversity . This also makes it difficult to appreciate and elucidate the specific endogenous roles of the glycans within the organism that synthesizes them.

Neurol Res, 1999 Jun, 21(4), 391 - 8
Effects of microbial invasion on cerebral hemodynamics and oxygenation monitored by near infrared spectroscopy in experimental Escherichia coli meningitis in the newborn piglet; Park WS et al.; This study was carried out to elucidate the pathophysiologic mechanism of cerebral hyperemia observed during the early phase of bacterial meningitis . We tested the hypothesis that microbial invasion through the blood-brain barrier is responsible for cerebral vasodilation and hyperemia in meningitis . Escherichia coli was given either intravenously (i.v.) or intracisternally (i.c.) to closely mimic the primary or secondary bacterial invasion occurring in meningitis and newborn piglets were grouped according to their invasion results (+ or -); 12 in the i.v . (+) group, 14 in the i.v . (-) group, 13 in the i.c . (+) group, 15 in the i.c . (-) group . The results were compared with eight animals in the control group . Near infrared spectroscopy (NIRS) was employed to monitor changes in total hemoglobin (HbT), oxygenated hemoglobin (HbO), deoxygenated hemoglobin (Hb), deduced hemoglobin (HbD), and oxidized cytochrome aa3 (Cyt aa3) . HbT, as an index of cerebral blood volume, increased progressively in both i.v . (+) and i.v . (-) groups and became significantly different from control and baseline values at 2 h . Hb significantly increased only in i.v . (+) group . HbD, as an index of cerebral blood flow, decreased significantly in i.v . (+), i.v.(-) and i.c . (-) groups and this change was mitigated in i.c . (+) group, HbO was reduced in i.c . (-) group and this decrease was attenuated in i.c . (+) group . Increased Cyt aa3 was observed in all experimental groups after bacterial inoculation . Changes in ICP, blood pressure, cerebral perfusion pressure, blood or CSF glucose or lactate, CSF TNF-alpha level, or CSF leukocytes number were not associated with changes in NIRS findings . These findings suggest that primary or secondary bacterial invasion across the blood-brain barrier is primarily responsible for cerebral vasodilation and hyperemia observed during the early phase of bacterial meningitis.

Mol Immunol, 1999 Mar-Apr, 36(4-5), 249 - 60
Evasion of pathogens by avoiding recognition or eradication by complement, in part via molecular mimicry; Wurzner R; Most pathogens invading the human body are attacked by the host immune system directly following entry and usually also during most stages of the disease, especially when they are in contact with the blood . However, pathogens have developed an effective battery of specific strategies to overcome immune defense . This, far from being complete, review concentrates on evasion of pathogens by avoiding recognition or eradication by complement . The latter is achieved by removal of complement either by shedding it off the microbial surface, by consuming it away from the target membrane or by destroying it . Alternative procedures of avoiding eradication are the inhibition of complement activation or the employment of complement proteins via several highly sophisticated mechanisms, including the imitation of complement-like proteins (molecular mimicry).

Jpn J Thorac Cardiovasc Surg, 1999 May, 47(5), 199 - 203
Does preoperative chemotherapy cause adverse effects on the perioperative course of patients undergoing esophagectomy for carcinoma?
Baba M, Natsugoe S, Shimada M, Nakano S, Shirao K, Kusano C, Fukumoto T, Aikou T.
The aim of this study was to clarify whether preoperative chemotherapy caused adverse effects on the perioperative course of patients undergoing esophagectomy . A total of 42 esophageal cancer patients were entered into a randomized trial and were analyzed . Twenty-one patients were assigned to immediate surgery (Surgery Group) . The other 21 received two 5-day courses of chemotherapy comprising cisplatin (70 mg/m2) on day 1, and fluorouracil (700 mg/m2) and leucovorin (20 mg/m2) on each of days 1 to 5 (chemotherapy group) . Hospital mortality comprised of one patient (2.3%) who had undergone an operation in the beginning of this series at 21 days after chemotherapy . Thereafter, the interval between the chemotherapy and operation was prolonged, with the average being 35 +/- 7 days . Preoperatively, both the lymphocyte counts and serum albumin levels were not increased in the chemotherapy group of patients even though their body weights increased . In the chemotherapy group, the operation time and the blood loss were increased and, on the 1st postoperative day, the development of systemic inflammatory response syndrome was high but the level of C-reactive protein was low . The incidence of positive microbial cultures of sputum and/or wound discharge within 8 postoperative days was higher in the chemotherapy group (42.9%) than in the surgery group (4.8%) . The host defense damage caused by chemotherapy may be prolonged and may show adverse effects in patients undergoing esophagectomy in the early postoperative period . Minimally, a 4-week interval between the completion of chemotherapy and operation is recommended for preventing surgical mortality related to the preoperative chemotherapy.

J Biol Chem, 1999 Jul 16, 274(29), 20578 - 86
Broad spectrum thiopeptide recognition specificity of the Streptomyces lividans TipAL protein and its role in regulating gene expression; Chiu ML et al.; Microbial metabolites isolated in screening programs for their ability to activate transcription of the tipA promoter (ptipA) in Streptomyces lividans define a class of cyclic thiopeptide antibiotics having dehydroalanine side chains ("tails") . Here we show that such compounds of heterogeneous primary structure (representatives tested: thiostrepton, nosiheptide, berninamycin, promothiocin) are all recognized by TipAS and TipAL, two in-frame translation products of the tipA gene . The N-terminal helix-turn-helix DNA binding motif of TipAL is homologous to the MerR family of transcriptional activators, while the C terminus forms a novel ligand-binding domain . ptipA inducers formed irreversible complexes in vitro and in vivo (presumably covalent) with TipAS by reacting with the second of the two C-terminal cysteine residues . Promothiocin and thiostrepton derivatives in which the dehydroalanine side chains were removed lost the ability to modify TipAS . They were able to induce expression of ptipA as well as the tipA gene, although with reduced activity . Thus, TipA required the thiopeptide ring structure for recognition, while the tail served either as a dispensable part of the recognition domain and/or locked thiopeptides onto TipA proteins, thus leading to an irreversible transcriptional activation . Construction and analysis of a disruption mutant showed that tipA was autogenously regulated and conferred thiopeptide resistance . Thiostrepton induced the synthesis of other proteins, some of which did not require tipA.

J Biol Chem, 1999 Jul 16, 274(29), 20165 - 70
The inhibition of capacitative calcium entry due to ATP depletion but not due to glucosamine is reversed by staurosporine; Vemuri S et al.; The capacitative Ca2+ entry pathway in J774 macrophages is rapidly inhibited by the amino sugar glucosamine . This pathway is also inhibited by treatments such as 2-deoxy-D-glucose (2dGlc) or glucose deprivation that inhibit glycolysis and lead to significant decreases in cellular ATP and other trinucleotides . We sought to determine whether glucosamine's effect on capacitative Ca2+ entry was also due to ATP depletion, as has been suggested recently for its link to insulin resistance . In contrast to brief treatments with 2dGlc, there was no significant decrease in ATP following exposure to glucosamine . In addition, the 2dGlc-mediated inhibition of capacitative Ca2+ influx was reversed by staurosporine, a microbial alkaloid that inhibits a broad range of protein kinases . Staurosporine was also able to reverse the inhibition of capacitative Ca2+ entry seen following other treatments that decreased cellular ATP levels, including cytochalasin B and iodoacetic acid . Other inhibitors of protein kinase C, including bisindolylmaleimide, K252a, H-7, and calphostin C, were unable to mimic this effect of staurosporine . However, the inhibition of capacitative Ca2+ influx in the presence of glucosamine was not reversed by staurosporine . These data indicate that the inhibitory action on capacitative Ca2+ entry of glucosamine is distinct from that caused by ATP depletion.

Steroids, 1999 Mar, 64(3), 178 - 86
Recent advances in applied and mechanistic aspects of the enzymatic hydroxylation of steroids by whole-cell biocatalysts; Holland HL; Recent advances in microbial steroid hydroxylation are covered, including new biocatalysts and substrate groups and new methodologies such as the use of low-water systems, immobilised biocatalysts, genetically constructed biocatalysts and enzyme mimics . Mechanistic factors that control the regiochemistry and stereochemistry of steroid hydroxylation are also discussed.

Amino Acids, 1999, 16(3-4), 191 - 213
Enzymatic resolution of amino acids via ester hydrolysis; Miyazawa T; The present review outlines recent examples of enzyme-based resolution procedures for amino acids via the hydrolysis of their esters . The resolutions have been achieved by using proteases (alpha-chymotrypsin, subtilisin and other microbial proteases, and sulfhydryl proteases of plant origin) and lipases . Relevant work utilizing yeast and other microbial cells is also included.

J Mol Recognit, 1999 Jan-Feb, 12(1), 38 - 44
Receptins: a novel term for an expanding spectrum of natural and engineered microbial proteins with binding properties for mammalian proteins; Kronvall G et al.; A new term 'receptin', derived from recipere (lat.), is proposed to denote microbial binding proteins that interact with mammalian target proteins . An example of such a 'receptin' is staphyloccocal protein A which binds to the Fc part of many mammalian immunoglobulins . Several other types of 'receptins' are listed . This term may easily be distinguished from the similar term 'receptor', describing a binding site on a cell surface, mostly eukaryotic, where a secondary effect is induced inside the cell upon binding to a ligand . A receptin, however, does not necessarily have to induce a secondary event . Receptins include so called MSCRAMMs, adhesins, and also engineered receptins, affibodies, and engineered ligands . It denotes any protein of microbial origin, cell-bound or soluble, which can bind to a mammalian protein . It fulfills the need for an umbrella terminology for a large group of binding structures . In contrast, the term 'lectin' represents a group of proteins with affinity for carbohydrate structures . The new term 'receptin' includes a number of key microbial proteins involved in host-parasite interactions and in virulence . Some receptins are promising vaccine candidates .

Biotechnol Bioeng, 1999 Jul 5, 64(1), 74 - 81
Thermodynamic analysis of growth of methanobacterium thermoautotrophicum
Schill NA, Liu JS, Stockar Uv.
Growth of Methanobacterium thermoautotrophicum, an anaerobic archaebacterium using methanogenesis as the catabolic pathway, is characterized by large heat production rates, up to 13 W g-1, and low biomass yields, in the order of 0.02 C-mol mol-1 H2 consumed . These values, indicating a possibly "inefficient" growth mechanism, warrant a thermodynamic analysis to obtain a better understanding of the growth process . The growth-associated heat production (DeltarHX0, min) and the growth-associated Gibbs energy dissipation per mol biomass formed (DeltarGXmin) were -3730 kJ C-mol-1 and -802 kJ C-mol-1, respectively . The Gibbs energy change found in this study is indeed unusually high as compared to aerobic methylotrophes, but not untypical for methanogens grown on CO2 . It explains the low biomass yield . Based on the information available on the energetic metabolism and on an ATP balance, the biomass yield can be predicted to be approximately in the range of the experimentally determined value . The fact that the exothermicity exceeds vastly even the Gibbs energy change can be explained by a dramatic entropy decrease of the catabolic reaction . Microbial growth characterized by entropy reduction and correspondingly by unusually large heat production may be called entropy-retarded growth .

Biotechnol Bioeng, 1999 Jul 5, 64(1), 1 - 13
Efficiency of physical (light) or chemical (ABA, tetracycline, CuSO4 or 2-CBSU)-stimulus-dependent gus gene expression in tobacco cell suspensions; Boetti H et al.; In this study, the efficiency of inducible promoters to switch on gene expression in the presence of inducer or to switch it off in its absence was evaluated in tobacco cell suspensions transformed with the gus gene coding sequence . Either plant (pats1A, pSalT, pIn2-2) or microbial (pMre, pTet) inducible promoters were used to drive gus expression . The inducers were light, abscisic acid, 2-CBSU, CuSO4, tetracycline, respectively . For each construct (inducible promoter-gus coding sequence), the optimal induction conditions were determined (inducer concentration, induction time, and age of cells in culture cycle before induction) . The efficiency of the inducible promoter was then evaluated under optimal induction conditions . GUS-expression levels obtained under non-inducing and inducing conditions were systematically compared . Thirty or forty percent of the clones transformed with the pSalT-gus or pTet-gus construct, respectively, showed high induction rates (>1000) and GUS activities of the same order as those obtained with a constitutive system . However, basal GUS levels were always high for the pTet-gus cell lines . Seventy or eighty-five percent of the cell lines transformed with the pMre-gus or pln2-2-gus construct, respectively, had induction rates of 1.5 to 1000 . The pats1A-gus construct gave very low induction rates-55% of cell lines had induction rates less than 1.5 . Only the pSalt-gus construct gave both the highest induction rates and basal GUS-levels equivalent to the endogenous GUS background .

J Periodontol, 1999 Jun, 70(6), 610 - 7
Opsonophagocytic effect of antibody against recombinant conserved 40-kDa outer membrane protein of Porphyromonas gingivalis; Saito S et al.; BACKGROUND: Porphyromonas gingivalis is associated with the initiation and progression of adult periodontitis . The outer membrane proteins of the bacteria are potentially important targets for interaction with host defense systems . A 40-kDa outer membrane protein (40-kDa OMP) is conserved among many strains of P . gingivalis . We have cloned the gene for 40-kDa OMP from P . gingivalis 381 and produced a recombinant protein . For the development of recombinant 40-kDa OMP as a component of a vaccine for passive immunization, the elucidation of the roles of the anti-recombinant 40-kDa OMP antibody in the host defense against P . gingivalis is essential . The objective of this study was to determine the opsonic capacity of the antibody for phagocytosis by neutrophils which play a key role in the immune response to microbial infections . METHODS: To test the opsonic activity of a rabbit polyclonal antibody against r40-kDa OMP (r40-kDa OMP Ab) on human neutrophils to phagocytize P . gingivalis, we constructed a reproducible in vitro model of P . gingivalis-neutrophil interaction using the human promyelocytic cell line HL-60 . RESULTS: We demonstrated that r40-kDa OMP Ab in the presence of human complement successfully opsonized {3H}-thymidine-labeled P . gingivalis as a target for phagocytosis by HL-60 cells differentiated with dimethyl sulfoxide . The phagocytized bacteria were then intracellularly killed and lysed, and the radioactive degradation debris egested into the culture medium . CONCLUSIONS: We conclude that antibody against r40-kDa OMP has opsonic activity on human neutrophil function for phagocytosis of P . gingivalis . Subgingival bacteria are coated in vivo with immunoglobulin and complement . When the antibody is specific for crevicular bacteria, immunological interactions can be expected in the crevice . Our observations suggest that the anti-recombinant 40-kDa OMP antibody in concert with the crevicular complement may prevent P . gingivalis colonization r40-kDa OMP may contribute to the development of a local immunotherapy when applied to the crevice of a patient with P . gingivalis-related periodontitis which relates to susceptibility for certain systemic diseases such as diabetes mellitus, cardiovascular disease, and preterm labor.

Proc Natl Acad Sci U S A, 1999 Jul 6, 96(14), 7998 - 8002
The agricultural pathology of ant fungus gardens
Currie CR, Mueller UG, Malloch D.
Gardens of fungus-growing ants (Formicidae: Attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure "monocultures." We conducted extensive isolations of "alien" (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants . Contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that are only known from attine gardens and that are found in most attine nests . These specialized garden parasites, belonging to the microfungus genus Escovopsis (Ascomycota: anamorphic Hypocreales), are horizontally transmitted between colonies . Consistent with theory of virulence evolution under this mode of pathogen transmission, Escovopsis is highly virulent and has the potential for rapid devastation of ant gardens, leading to colony mortality . The specialized parasite Escovopsis is more prevalent in gardens of the more derived ant lineages than in gardens of the more "primitive" (basal) ant lineages . Because fungal cultivars of derived attine lineages are asexual clones of apparently ancient origin whereas cultivars of primitive ant lineages were domesticated relatively recently from free-living sexual stocks, the increased virulence of pathogens associated with ancient asexual cultivars suggests an evolutionary cost to cultivar clonality, perhaps resulting from slower evolutionary rates of cultivars in the coevolutionary race with their pathogens.

J Microbiol Methods, 1999 Jul, 37(1), 17 - 22
Quantification of bacterial lead resistance via activity assays; Konopka A et al.; The level of microbial resistance to heavy metals is an important issue for the microbial ecology of heavy metal-contaminated habitats . However, assays based upon growth in nutrient media will overestimate the resistance level due to metal ion interactions with inorganic and organic components . The analysis of Pb-resistant bacteria isolated from soils containing up to 38 mmol total Pb x kg(-1) indicated that PYT80B medium which did not contain inorganic salts, contained low amounts of organic matter, and was buffered with a molecule that did not interact with metal ions (2-N-morpholinoethanesulfonic acid (MES)) provided the lowest estimates of lead resistance . However, better results were obtained by assaying metabolic activity (aerobic respiration) of resting cells suspended in 10 mM MES . By this criterion, 50% inhibition of Arthrobacter JS7 was found at 37 microM Pb(NO3)2 . The effects of Pb+2 concentrations upon respiration of resting cells and growth rate in PYT80B medium were similar . The activity assay also showed that metal resistance was induced to higher levels when Arthrobacter JS7 was grown in the presence of Pb.

Am Fam Physician, 1999 Jun, 59(11), 3093 - 102, 3107-8
Kawasaki disease; Taubert KA et al.; Kawasaki disease is a leading cause of acquired heart disease among children in the United States and other developed countries . Most children who contract this illness are less than two years old, and 80 percent of affected children are younger than five years of age . A generalized vasculitis of unknown etiology, Kawasaki disease can cause coronary artery abnormalities, including coronary aneurysms . From 20 to 25 percent of untreated children develop coronary artery abnormalities, which may resolve or persist . These abnormalities are of particular concern because they can lead to thrombosis, evolve into segmental stenosis or, rarely, rupture . The principal cause of death from Kawasaki disease is myocardial infarction . The cause of the disease remains unknown, but epidemiologic investigations and the clinical presentation suggest a microbial agent . Diagnostic criteria, including fever and other principal features, have been established . In the acute phase of the disease, treatment with acetylsalicylic acid and intravenously administered immunoglobulin is directed at reducing inflammation of the coronary arteries and myocardium . Early recognition and treatment of Kawasaki disease can reduce the development of potentially life-threatening coronary artery abnormalities.

Trends Microbiol, 1999 Jul, 7(7), 275 - 81
The cellulosome concept as an efficient microbial strategy for the degradation of insoluble polysaccharides; Shoham Y et al.; The cellulosome is an extracellular supramolecular machine that can efficiently degrade crystalline cellulosic substrates and associated plant cell wall polysaccharides . The cellulosome arrangement can also promote adhesion to the insoluble substrate, thus providing individual microbial cells with a direct competitive advantage in the utilization of the soluble hydrolysis products.

J S C Med Assoc, 1999 Jun, 95(6), 227 - 30
The modifiable factors contributing to leading causes of death in South Carolina; Pilibosian ED et al.; In 1996, there were 34,035 deaths in South Carolina . Almost 70 percent of these deaths were due to chronic diseases . There are known ways to prevent chronic diseases from developing or at least delay their developmental process, thereby lengthening years of life . The purpose of this paper is to report modifiable risk factors for mortality related to leading causes of death . The top ten causes of death in South Carolina were obtained from the South Carolina Department of Health and Environmental Control . Estimates of the number of deaths due to certain modifiable risk factors were made using results of a study published by McGinnis and Foege . The percentage of deaths due to each cause was adapted to South Carolina death certificate data from the national estimates . Results indicate that small modifications in individual lifestyles could prevent or delay nearly 50 percent of deaths in South Carolina annually . Tobacco use, diet and physical activity, and misuse of alcohol contribute to the largest number of deaths . Other modifiable behaviors contributing to the 50 percent mortality are microbial agents, toxic agents, firearms, sexual behavior, motor vehicle accidents, and illicit use of drugs . The implication in these findings is that these risk factors for mortality are mainly modifiable . There are many causes of death that may be delayed due to these modifiable risk factors . By looking at preventable causes of death, rather than focusing on traditional causes of death, it becomes clear that prevention strategies are critically important.

Biophys J, 1999 Jul, 77(1), 493 - 504
Molecular dynamics of microbial lipases as determined from their intrinsic tryptophan fluorescence; Graupner M et al.; We have studied the intrinsic tryptophan fluorescence of the lipases from Chromobacterium viscosum (CVL), Pseudomonas species (PSL), and Rhizopus oryzae (ROL) in aqueous buffer, zwitterionic detergent micelles, and isopropanol-water mixtures . It was the purpose of this study to obtain information about biophysical properties of the respective enzymes under conditions that modulate enzyme activities and stereoselectivities to a significant extent . According to their decay-associated emission spectra, CVL tryptophans are located in the hydrophobic interior of the protein . In contrast, the PSL and ROL tryptophans are probably confined to the core and the surface of the lipase . From the tryptophan lifetime distributions it can be concluded that the conformation of CVL is not much affected by detergent or organic solvent (isopropanol) . Accordingly, CVL is enzymatically active in these systems and most active in the presence of isopropanol . In contrast, ROL and PSL show high conformational mobility, depending on the solvent, because their lifetime distributions are very different in the presence and absence of detergent or isopropanol . Time-resolved anisotropy studies provided evidence that the lipases exhibit very high internal molecular flexibility . This peculiar feature of lipases is perhaps the key to the great differences in activity and stereoselectivity observed in different reaction media . Furthermore, information about self-association of the lipases in different solvents could be obtained . PSL, but not CVL and ROL, forms aggregates in water . Lipase aggregation can be reversed by the addition of detergent or isopropanol, which competes for the hydrophobic surface domains of this protein . This dissociation could efficiently contribute to the increase in lipase activity in the presence of a detergent or isopropanol.

Appl Environ Microbiol, 1999 Jul, 65(7), 3164 - 74
Seasonal dynamics of bacterioplankton community structure in a eutrophic lake as determined by 5S rRNA analysis; Hofle MG et al.; Community structure of bacterioplankton was studied during the major growth season for phytoplankton (April to October) in the epilimnion of a temperate eutrophic lake (Lake Plusssee, northern Germany) by using comparative 5S rRNA analysis . Estimates of the relative abundances of single taxonomic groups were made on the basis of the amounts of single 5S rRNA bands obtained after high-resolution electrophoresis of RNA directly from the bacterioplankton . Full-sequence analysis of single environmental 5S rRNAs enabled the identification of single taxonomic groups of bacteria . Comparison of partial 5S rRNA sequences allowed the detection of changes of single taxa over time . Overall, the whole bacterioplankton community showed two to eight abundant (>4% of the total 5S rRNA) taxa . A distinctive seasonal succession was observed in the taxonomic structure of this pelagic community . A rather-stable community structure, with seven to eight different taxonomic units, was observed beginning in April during the spring phytoplankton bloom . A strong reduction in this diversity occurred at the beginning of the clear-water phase (early May), when only two to four abundant taxa were observed, with one taxon dominating (up to 72% of the total 5S rRNA) . The community structure during summer stagnation (June and July) was characterized by frequent changes of different dominating taxa . During late summer, a dinoflagellate bloom (Ceratium hirudinella) occurred, with Comamonas acidovorans (beta-subclass of the class Proteobacteria) becoming the dominant bacterial species (average abundance of 43% of the total 5S rRNA) . Finally, the seasonal dynamics of the community structure of bacterioplankton were compared with the abundances of other major groups of the aquatic food web, such as phyto- and zooplankton, revealing that strong grazing pressure by zooplankton can reduce microbial diversity substantially in pelagic environments.

Appl Environ Microbiol, 1999 Jul, 65(7), 3064 - 70
Composition of toluene-degrading microbial communities from soil at different concentrations of toluene; Hubert C et al.; Toluene-degrading bacteria were isolated from hydrocarbon-contaminated soil by incubating liquid enrichment cultures and agar plate cultures in desiccators in which the vapor pressure of toluene was controlled by dilution with vacuum pump oil . Incubation in desiccators equilibrated with either 100, 10, or 1% (wt/wt) toluene in vacuum pump oil and testing for genomic cross-hybridization resulted in four genomically distinct strains (standards) capable of growth on toluene (strains Cstd1, Cstd2, Cstd5, and Cstd7) . The optimal toluene concentrations for growth of these standards on plating media differed considerably . Cstd1 grew best in an atmosphere equilibrated with 0.1% (wt/wt) toluene, but Cstd5 failed to grow in this atmosphere . Conversely, Cstd5 grew well in the presence of 10% (wt/wt) toluene, which inhibited growth of Cstd1 . 16S ribosomal DNA sequencing and cross-hybridization analysis indicated that both Cstd1 and Cstd5 are members of the genus Pseudomonas . An analysis of the microbial communities in soil samples that were incubated with 10% (wt/wt) toluene with reverse sample genome probing indicated that Pseudomonas strain Cstd5 was the dominant community member . However, incubation of soil samples with 0.1% (wt/wt) toluene resulted in a community that was dominated by Pseudomonas strain Q7, a toluene degrader that has been described previously (Y . Shen, L . G . Stehmeier, and G . Voordouw, Appl . Environ . Microbiol . 64:637-645, 1998) . Q7 was not able to grow by itself in an atmosphere equilibrated with 0.1% (wt/wt) toluene but grew efficiently in coculture with Cstd1, suggesting that toluene or metabolic derivatives of toluene were transferred from Cstd1 to Q7.

Appl Environ Microbiol, 1999 Jul, 65(7), 2994 - 3000
Comparative diversity of ammonia oxidizer 16S rRNA gene sequences in native, tilled, and successional soils; Bruns MA et al.; Autotrophic ammonia oxidizer (AAO) populations in soils from native, tilled, and successional treatments at the Kellogg Biological Station Long-Term Ecological Research site in southwestern Michigan were compared to assess effects of disturbance on these bacteria . N fertilization effects on AAO populations were also evaluated with soils from fertilized microplots within the successional treatments . Population structures were characterized by PCR amplification of microbial community DNA with group-specific 16S rRNA gene (rDNA) primers, cloning of PCR products and clone hybridizations with group-specific probes, phylogenetic analysis of partial 16S rDNA sequences, and denaturing gradient gel electrophoresis (DGGE) analysis . Population sizes were estimated by using most-probable-number (MPN) media containing varied concentrations of ammonium sulfate . Tilled soils contained higher numbers than did native soils of culturable AAOs that were less sensitive to different ammonium concentrations in MPN media . Compared to sequences from native soils, partial 16S rDNA sequences from tilled soils were less diverse and grouped exclusively within Nitrosospira cluster 3 . Native soils yielded sequences representing three different AAO clusters . Probes for Nitrosospira cluster 3 hybridized with DGGE blots from tilled and fertilized successional soils but not with blots from native or unfertilized successional soils . Hybridization results thus suggested a positive association between the Nitrosospira cluster 3 subgroup and soils amended with inorganic N . DGGE patterns for soils sampled from replicated plots of each treatment were nearly identical for tilled and native soils in both sampling years, indicating spatial and temporal reproducibility based on treatment.

Biochemistry, 1999 Jun 15, 38(24), 7678 - 88
Escherichia coli methionine aminopeptidase: implications of crystallographic analyses of the native, mutant, and inhibited enzymes for the mechanism of catalysis; Lowther WT et al.; By improving the expression and purification of Escherichia coli methionine aminopeptidase (eMetAP) and using slightly different crystallization conditions, the resolution of the parent structure was extended from 2.4 to 1.9 A resolution . This has permitted visualization of the coordination geometry and solvent structure of the active-site dinuclear metal center . One solvent molecule (likely a mu-hydroxide) bridges the trigonal bipyramidal (Co1) and octahedral (Co2) cobalt ions . A second solvent (possibly a hydroxide ion) is bound terminally to Co2 . A monovalent cation binding site was also identified about 13 A away from the metal center at an interface between the two subdomains of the protein . The first structure of a substrate-like inhibitor, (3R)-amino-(2S)-hydroxyheptanoyl-L-Ala-L-Leu-L-Val-L-Phe-OMe, bound to a methionine aminopeptidase, has also been determined . This inhibitor coordinates the metal center through four interactions as follows: (i) ligation of the N-terminal (3R)-nitrogen to Co2, (ii, iii) bridging coordination of the (2S)-hydroxyl group, and (iv) terminal ligation to Co1 by the keto oxygen of the pseudo-peptide linkage . Inhibitor binding occurs with the displacement of two solvent ligands and the expansion of the coordination sphere of Co1 . In addition to the tetradentate, bis-chelate metal coordination, the substrate analogue forms hydrogen bonds with His79 and His178, two conserved residues within the active site of all MetAPs . To evaluate their importance in catalysis His79 and His178 were replaced with alanine . Both substitutions, but especially that of His79, reduce activity . The structure of the His79Ala apoenzyme and the comparison of its electronic absorption spectra with other variants suggest that the loss in activity is not due to a conformational change or a defective metal center . Two different reaction mechanisms are proposed and are compared to those of related enzymes . These results also suggest that inhibitors analogous to that reported here may be useful in preventing angiogenesis in cancer and in the treatment of microbial and fungal infections.

Microb Ecol, 1999 Jul, 38(1), 50 - 57
Decomposition and CO2 Evolution from Standing Litter of the Emergent Macrophyte Erianthus giganteus; Kuehn KA et al.; > Abstract Decomposition of standing litter of the emergent macrophyte Erianthus giganteus (plumegrass) was quantified in a small freshwater wetland in Alabama, USA . Living green shoots of E . giganteus were tagged and periodically retrieved for determination of leaf and culm mass loss, litter-associated fungal biomass (ergosterol), and nitrogen and phosphorus concentrations . Laboratory studies were also conducted to examine the effects of plant litter moisture content and temperature on rates of CO2 evolution from plant litter . Culm and leaf material lost 25 and 32% AFDM, respectively, during plant senescence and early litter decay . Fungal biomass, as determined by ergosterol concentrations, increased significantly in both leaf and culm litter during decomposition, with maximum biomass accounting for 3.7 and 6.7% of the total detrital weight in culm and leaf litter, respectively . Spatial differences in fungal biomass were observed along the culm axis, with upper regions of the culm accumulating significantly greater amounts of fungal mass than basal regions (p < 0.01, ANOVA) . Rates of CO2 evolution from both leaf and culm litter increased rapidly after wetting (0 to 76 microg CO2-C g-1 AFDM h-1 within 5 min) . In addition, rates of CO2 evolution from water saturated culms increased exponentially as the temperature was increased from 10 to 30 degrees C . These results provide evidence that considerable microbial colonization and mineralization of standing emergent macrophyte litter can occur before collapse of senescent shoot material to the water and sediment surface.http://link.springer-ny.com/link/service/journals/00248/bibs/38n1p50.html

Curr Opin Microbiol, 1999 Jun, 2(3), 257 - 64
Biodesulfurization; McFarland BL; Microbial sulfur-specific transformations have been identified that selectively desulfurize organic sulfur compounds in fossil fuels . Recent discoveries related to biodesulfurization mechanisms may lead to commercial applications of biodesulfurization through engineering recombinant strains for over-expression of biodesulfurization genes, removal of end product repression, and/or by combining relevant industrial and environmental traits with improvements in bioprocess design.

Curr Opin Microbiol, 1999 Jun, 2(3), 323 - 7
Terminal restriction fragment length polymorphism (T-RFLP): an emerging method for characterizing diversity among homologous populations of amplification products; Marsh TL; Terminal restriction fragment length polymorphism is a recent molecular approach that can assess subtle genetic differences between strains as well as provide insight into the structure and function of microbial communities . The technique has both high sensitivity and throughput making it ideal for comparative analyses.

Curr Opin Microbiol, 1999 Jun, 2(3), 306 - 11
The role of short sequence repeats in epidemiologic typing; van Belkum A; Short sequence repeats (SSRs), also known as variable number of tandem repeats or micro-satellites, are inherently unstable entities that undergo frequent variation in the number of repeated units through slipped strand mispairing during DNA synthesis . In humans, unit number variability in SSRs has been associated with the occurrence of specific genetic diseases, whereas in micro-organisms SSRs have been elegantly linked to modulation of gene expression . Knowledge of the functional constraints imposed upon the SSRs sheds light on their potential use as molecular clocks for monitoring microbial genome evolution . Although microbial SSR genotypes have been used with increasing frequency for studying the epidemiology and evolution of microbial strains and isolates, such approaches should be used with caution.

Gastroenterol Nurs, 1999 Mar-Apr, 22(2), 63 - 8
Microbial bioburden in endoscope reprocessing and an in-use evaluation of the high-level disinfection capabilities of Cidex PA; Vesley D et al.; Most endoscopy clinics use 2% glutaraldehyde as a high-level disinfectant for reprocessing flexible endoscopes . However, even with contact times greater than 30 minutes, survival of organisms has been documented . We compared the high-level disinfection capabilities of glutaraldehyde (45-minute immersion) with a new peracetic acid germicide (20- to 25-minute immersion) . Channels, valve housings, and outer sheaths were sampled to quantify bioburden levels after a patient procedure, after manual cleaning, and after disinfection . Total mean bioburden after clinical use was greater than 6 log10 colony-forming units (CFU) . Manual cleaning reduced the bioburden by means of 4.7 log10 CFU (gastroscopes) and 6.2 log10 CFU (colonoscopes) . High-level disinfection with the new product was achieved in five of six (product stressed by EPA Reuse Test) and 7 of 10 (product stressed by dilution and organic load) successfully disinfected endoscopes, whereas glutaraldehyde achieved it in 4 of 10 (product stressed by dilution and organic load) . We conclude that the new peracetic acid product (20- and 25-minute contact time) is at least as effective as glutaraldehyde (45-minute contact time) for reducing the bioburden of vegetative aerobic organisms in endoscopes.

Biomaterials, 1999 Jun, 20(12), 1143 - 50
Mechanical loading of bovine pericardium accelerates enzymatic degradation; Ellsmere JC et al.; Bioprosthetic heart valves fail as the result of two simultaneous processes: structural deterioration and calcification . Leaflet deterioration and perforation have been correlated with regions of highest stress in the tissue . The failures have long been assumed to be due to simple mechanical fatigue of the collagen fibre architecture; however, we have hypothesized that local stresses-and particularly dynamic stresses-accelerate local proteolysis, leading to tissue failure . This study addresses that hypothesis . Using a novel, custom-built microtensile culture system, strips of bovine pericardium were subjected to static and dynamic loads while being exposed to solutions of microbial collagenase or trypsin (a non-specific proteolytic enzyme) . The time to extend to 30% strain (defined here as time to failure) was recorded . After failure, the percentage of collagen solubilized was calculated based on the amount of hydroxyproline present in solution . All data were analyzed by analysis of variance (ANOVA) . In collagenase, exposure to static load significantly decreased the time to failure (P < 0.002) due to increased mean rate of collagen solubilization . Importantly, specimens exposed to collagenase and dynamic load failed faster than those exposed to collagenase under the same average static load (P = 0.02) . In trypsin, by contrast, static load never led to failure and produced only minimal degradation . Under dynamic load, however, specimens exposed to collagenase, trypsin, and even Tris/CaCl2 buffer solution, all failed . Only samples exposed to Hanks' physiological solution did not fail . Failure of the specimens exposed to trypsin and Tris/CaCl2 suggests that the non-collagenous components and the calcium-dependent proteolytic enzymes present in pericardial tissue may play roles in the pathogenesis of bioprosthetic heart valve degeneration.

Biopolymers, 1999 Aug, 50(2), 193 - 200
Enzymatic ligation for synthesis of single-chain analogue of monellin by transglutaminase; Ota M et al.; Monellin, a sweet protein, consists of two noncovalently associated polypeptide chains: an A chain of 44 amino acid residues and a B chain of 50 residues . Microbial transglutaminase (MTGase) was used for ligation of the monellin subunits without any protecting groups, and without activation of the C alpha-carboxyl group at the C-terminus . Since a peptide fragment LLQG is a good substrate for MTGase to form an amide bond between the gamma-amide group of the Gln residue and the epsilon-amino group of Lys, a monellin B chain analogue in which LLQG was elongated at the C-terminus (B-LLQG) was synthesized by solid-phase synthesis . The monellin A chain analogue in which KGK was elongated at the N-terminus (KGK-A) was synthesized by the same method as that of the B chain analogue . The KGK-A chain and the B-LLQG chain were coupled by MTGase to give single-chain analogue of monellin . The single-chain analogue of monellin was characterized by analytical reverse phase high performance liquid chromatography, electrospray ionization, and amino acid analyses . All analyses gave satisfactory results . The single-chain analogue of monellin was more heat stable than natural monellin.

J Rheumatol, 1999 Jun, 26(6), 1306 - 11
Presence of antibodies against Helicobacter pylori and its heat-shock protein 60 in the serum of patients with Sjögren's syndrome; Aragona P et al.; OBJECTIVE: Helicobacter pylori infection elicits a local and systemic immune response against bacterial antigens, including a heat-shock protein of 60 kDa (HSP60) . The homology between microbial and human HSP suggests that the immune response to bacterial HSP may play a role in the pathogenesis of autoimmune disorders . Since gastric involvement and H . pylori have been reported in Sjogren's syndrome (SS), we investigated the prevalence of antibodies against H . pylori and its specific HSP60 in sera from patients with SS . METHODS: Four groups of patients were studied . Group 1, 34 patients with primary SS (pSS); Group 2.19 patients with secondary SS; Group 3, 22 patients with various autoimmune diseases and Group 4, 43 healthy controls . Serum IgG levels against HSP60 were determined by an ELISA using recombinant full length HSP60 expressed in Escherichia coli, as the antigen . To confirm the H . pylori infection, a commercial ELISA was used . RESULTS: Out of 34 patients in Group 1, 27 (79.4%) and 30 (88.2%) had antibodies against H . pylori and its HSP60, respectively . The prevalence was significantly higher than that found in Group 3 (18.2%, p < 0.0001 and 27.3%, p < 0.0001) and in Group 4 (48.8%, p < 0.005 and 37.2%, p < 0.0001) but not than that of Group 2 (48.8% and 37.2%) . If the prevalence of patients either positive or negative for both antibodies was considered, a statistically significant difference was found between Group I and respectively Groups 3 and 4 . CONCLUSION: The hypothetical role of HSP60 in the development of the immune response both in pSS and secondary SS seems strictly linked to the prevalence rate of H . pylori infection.

Am J Dermatopathol, 1999 Jun, 21(3), 234 - 40
A clinical and histologic study of 37 cases of immunoglobulin A-associated vasculitis; Magro CM et al.; Immunoglobulin (Ig) A-associated vasculitis is commonly equated with the multiorgan systemic vasculitic syndrome Henoch-Schonlein purpura (HSP), which occurs predominantly in the pediatric age group . By natural language search of the databases of two outpatient dermatopathology practices, the authors selected for review 37 cases of IgA-associated vasculitis, 23 of which were associated with antecedent infection, most commonly of the upper respiratory tract . Criteria for a diagnosis of HSP were met in 15 cases, 13 of which were in the setting of prior infection . Lower extremity skin involvement was ubiquitous . A more widespread form of vasculitis was also seen, particularly in the setting of previous infection . Several of the patients with previous infection had underlying medical illnesses including rheumatoid arthritis, atopy, renal failure, lupus erythematosus, insulin dependent diabetes mellitus, autoimmune thyroid disease, and Wegener's granulomatosis . In those patients lacking an apparent microbial trigger, Sjogren's disease with anti-Ro antibodies and hypergammaglobulinemia, lupus erythematosus, inflammatory bowel disease, IgA paraproteinemia, bronchogenic and prostatic carcinoma, cryoglobulinemia, and lymphoma were uncovered . Regardless of whether an infectious stimulus was implicated, certain cofactors with the potential to enhance vascular injury were uncovered; these included anti-Ro antibodies, antineutrophil cytoplasmic antibody, diabetic microangiopathy, and a hyperviscosity state . In the infective group, a pustular vasculitis, defined as a neutrophilic vascular reaction in concert with epithelial pustulation, was seen in 81% of cases versus 33% in the noninfectious group (p = 0.02) . The prototypic histomorphology in the noninfective group was one of a mild cell poor leukocytoclastic vasculitis; Vasculitis was of greater severity in patients with antecedent infection (p = 0.026) . An infectious trigger, typically of mucosal origin, can frequently be identified in patients with cutaneous IgA-associated vasculitis, especially those with the symptom complex of HSP . The light microscopy appears to distinguish patients who have an infectious trigger from those who do not . IgA-associated vasculitis may be a clue to the presence of certain underlying disorders where there is immune dysregulation or enhanced susceptibility to immune complex entrapment.

J Microbiol Methods, 1999 Jun, 36(3), 203 - 13
Comparison of two kinds of Biolog microplates (GN and ECO) in their ability to distinguish among aquatic microbial communities; Choi KH et al.; We compared the abilities of Biolog's GN and ECO plates to distinguish among aerobic and heterotrophic bacterial communities in samples from six aquatic environments . The Biolog system is based on interpreting patterns of sole-carbon substrate utilization indicated by color development in a 96-well microtiter plate . Whether of fresh or saltwater origin, bacterial communities utilized > 95% of substrates in both types of plates . Samples from any one environment exhibited similar time courses of average well color development (AWCD) in both GN and ECO plates . Principal component analysis was performed on data sets resulting from combinations of algorithms (AWCD and curve-integration methods) and levels of color development (end-point and set-point approaches) . In all cases, the two types of plates demonstrated an equal capacity to discriminate among the heterotrophic expressions of the six microbial communities . Substantial deviation from an anticipated 1:1 correspondence occurred when color development of 25 substrates common to both types of plates was compared . The discrepancies likely are related to the different formulations of low-nutrient media in GN and ECO plates.

J Neuroimmunol, 1999 Jan 1, 93(1-2), 149 - 55
Synergistic interaction of catecholamine hormones and Mycobacterium avium results in the induction of interleukin-10 mRNA expression by murine peritoneal macrophages; Chen L et al.; The results of this investigation provides evidence that catecholamine hormones interact with macrophages that are infected with Mycobacterium avium resulting in the induction of IL-10 mRNA and protein . The effect of catecholamine hormones was prevented by treating the cells with the beta-adrenergic receptor antagonist propranolol but not by alpha-adrenergic antagonist phentolamine . The effect of catecholamine stimulation was mimicked by the addition of beta-2 adrenergic agonists and by the addition of cAMP to the infected macrophage cultures . These observations suggest that sympathetic nervous system activation together with microbial infection results in a synergistic interaction that could result in the control of inflammatory processes.

FEMS Immunol Med Microbiol, 1999 Jun, 24(2), 193 - 9
Molecular methods for typing of Helicobacter pylori and their applications; Colding H et al.; Microbial typing is a useful tool in clinical epidemiology for defining the source and route of infection, for studying the persistence and reinfection rates, clonal selection in the host and bacterial evolution . Phenotypic methods such as biotyping, serotyping and hemagglutinin typing have little discriminatory power compared to genotypic methods concerning the typing of Helicobacter pylori . Therefore great efforts have been made to establish useful molecular typing methods . In this context, the most frequently used genotypic methods are described based on our own experience and the literature: (1) restriction endonuclease analysis, (2) endonuclease analysis using pulsed-field gel electrophoresis, (3) ribotyping, (4) polymerase chain reaction (using either random primers or repetitive DNA sequence primers), and (5) polymerase chain reaction-restriction fragment length polymorphism analysis of e.g . the urease genes . Furthermore, reproducibility, discriminatory power, ease of performance and interpretation, cost and toxic procedures of each method are assessed . To date no direct comparison of all the molecular typing methods described has been performed in the same study with the same H . pylori strains . However, PCR analysis of the urease gene directly on suspensions of H . pylori or gastric biopsy material seems to be useful for routine use and applicable in specific epidemiological situations.

Bioessays, 1999 May, 21(5), 377 - 81
The genome of Rickettsia prowazekii and some thoughts on the origin of mitochondria and hydrogenosomes; Muller M et al.; The sequence of an alpha-proteobacterial genome, that of Rickettsia prowazekii, is a substantial advance in microbial and evolutionary biology . The genome of this obligately aerobic intracellular parasite is small and is apparently still undergoing reduction, reflecting gene losses attributable to its intracellular parasitic lifestyle . Evolutionary analyses of proteins encoded in the genome contain the strongest phylogenetic evidence to date for the view that mitochondria descend from alpha-proteobacteria . Although both Rickettsia and mitochondrial genomes are highly reduced, it appears that genome reduction in these lineages has occurred independently . Rickettsia's genome encodes an ATP-generating machinery that is strikingly similar to that of aerobic mitochondria . But it does not encode homologues for the ATP-producing pathways of anaerobic mitochondria or hydrogenosomes, leaving an important issue regarding the origin and nature of the ancestral mitochondrial symbiont unresolved.

J Anim Sci, 1999 Jun, 77(6), 1587 - 96
Influence of grain source on ruminal characteristics and rate, site, and extent of digestion in beef steers; Philippeau C et al.; Six cannulated Salers steers (305 +/- 17 kg initial BW) were used in a double 3 x 3 Latin square design to compare the effects of the nature of the cereal (wheat vs corn) and the corn genotype (dent vs flint) on rate, site, and extent of digestion of high-concentrate diets . The cereals were coarsely cracked, and the diets were balanced to have the same percentage of starch (47.7 +/- 2.3%) and CP (14.6 +/- .7%) . Differences in ruminal starch digestion were observed between wheat- and corn-based diets (86.6 vs 47.8%; P < .001) and between corn genotypes (60.8 vs 34.8% for dent and flint corns; P < .001) . For flint corn, more than half the starch was digested in the hindgut . Total tract digestion of starch was greater (P < .001) by steers fed wheat than by those fed corn and did not differ (P > .1) between the two corn genotypes . Ruminal mean pH (P < .01) was lower and total VFA concentration (P < .1) was higher for wheat- than for corn-based diets . Ruminal acetate:propionate tended to increase with the decrease in the amount of starch degraded in the rumen, but differences were not significant (P > .1) . When wheat replaced corn, nonammonia, nonmicrobial N duodenal flow decreased (P < .01), and microbial duodenal flow increased (P < .05), so there were no differences in the duodenal flow of nonammonia N duodenal flow (P > .1) . The lower nonammonia N duodenal flow for the dent corn- than for the flint corn-based diet (P < .05) was related to a lower passage of nonammonia, nonmicrobial N into the duodenum . Efficiency of microbial protein synthesis was inversely correlated with the amount of starch degraded in the rumen . Nature of the cereal, wheat vs corn, and genotype of the corn, dent vs flint, alter the site and extent of starch digestion.

J Anim Sci, 1999 Jun, 77(6), 1565 - 71
In situ neutral detergent insoluble nitrogen as a method for measuring forage protein degradability; Mass RA et al.; A method of estimating the undegraded intake protein (UIP) concentration of forages was developed and validated with a series of in situ experiments . The hypothesis was that UIP calculated from in situ neutral detergent insoluble N (NDIN) is equal to total in situ N minus the microbial N that is estimated from purines (MN) . The in situ disappearance rates of total in situ N (TN), MN, and NDIN were measured for six hay samples and two range masticate samples . Hypothetical rates of passage (2 or 5%/h) were used to calculate UIP (% of DM) for each N pool . Estimates of UIP from TN were higher (P = .0001) than those from either MN or NDIN, and MN estimates of UIP were similar (P = .48) to NDIN estimates . A low-N fiber source (solka floc) was incubated in situ for 8 h . Analysis of the residue detected purines before, but not after, neutral detergent extraction . Several in situ incubation (i.e., Dacron bag size and number of Dacron bags in a mesh bag) and neutral detergent extraction conditions were tested . None of the factors tested affected in situ NDIN disappearance (P > .05) . The hypothesis that NDIN is completely digestible in the rumen was tested . Estimates of the extent of NDIN digestion were made using 96-h in situ incubations, and UIP was recalculated for the test samples . Mean in situ UIP concentration decreased upon recalculation (P = .05) . In situ NDIN provides estimates of forage UIP that are equal to estimates from MN . Forage UIP estimates are less when extent of N degradation is estimated and included in the calculation.

Ann Acad Med Singapore, 1999 Jan, 28(1), 120 - 32
Immunological consequences of trauma and shock; Catania RA et al.; The immune system is a powerful, complex entity composed of numerous cell types and regulated by autocrine, paracrine, and hormonal mechanisms . Trauma and haemorrhagic shock induce numerous changes within this system which are ultimately deleterious and contribute to the high incidence of organ dysfunction and infectious complications seen following injury . Regional hypoxia and depletion of intracellular energy stores occur in response to diminished microcirculatory blood flow, and these changes alter cellular signalling and result in the release of pro-inflammatory cytokines and prostanoids which mediate further suppression of immune function . Neutrophil priming serves to induce tissue damage in critical organ systems such as the lungs, heart, liver, and gut, further insulting the injured organism . Depression of antigen presentation and cytokine elaboration by macrophages and other antigen presenting cells effectively prevents a normal response from the acquired immune system, and lymphocyte-monocyte interactions are squelched . The resulting depression in cell mediated and humoral immunity renders the organism susceptible to microbial infection and contributes to the morbidity and mortality associated with nosocomial infections . Hormonal modulation of the immune response is highly evident following trauma and haemorrhage, and the preponderance of male morbidity associated with sepsis can be explained by the depression in immune function seen in males, but not females in the pro-oestrous state . Despite the multitude of changes induced by trauma and haemorrhage, experimental studies have revealed several promising pharmacologic interventions which may serve to blunt the effect of injury on the immune system, and render the host competent to withstand the bacterial and viral challenges responsible for so much of the late mortality following severe injury.

Proteins, 1999 Jul 1, 36(1), 117 - 34
Conserved water molecules in a large family of microbial ribonucleases; Loris R et al.; We systematically analyzed the crystallographically determined water molecules of all known structures of RNase T1 and compared them to the ordered solvent in a large number of related microbial nucleases . To assess the crystallographers' impact on the interpretation of the solvent structure, we independently refined five validation structures from diffraction data derived from five isomorphous crystals of RNase T1 . We also compared the positions of water molecules found in 11 published isomorphous RNase T1 inhibitor complexes . These data suggest that the positions of most of the waters located on the surface of a protein and that are well-determined in the experimental electron density maps are determined primarily by crystal packing forces . Water molecules with less well-defined electron density are in general unique to one or a small number of crystal structures . Only a small number of the well-defined waters are found to be independent of the crystal environment . These waters have a low accessible surface area and B-factor, and tend to be conserved in the crystal structures of a number of evolutionary related ribonucleases as well . A single water molecule is found conserved in all known microbial ribonucleases.

Anticancer Res, 1999 Mar-Apr, 19(2A), 1037 - 42
Thionins from Viscum album L: influence of the viscotoxins on the activation of granulocytes; Stein GM et al.; BACKGROUND: Extracts from European mistletoe (Viscum album L.) are applied in adjuvant cancer treatment, and some components, especially the mistletoe lectins (ML) have been immunologically characterised, but not the thionins, termed viscotoxins (VT) . MATERIALS AND METHODS: The influence of the VT on human granulocytes was studied by flow cytometry: E.coli co-stimulated respiratory burst by oxidation of dihydrorhodamine 123 to rhodamine 123 and phagocytosis by ingestion of FITC-labelled E.coli . RESULTS: VT (25 and 250 micrograms/ml), in contrast to ML, significantly enhanced phagocytosis and burst activity . VT-rich mistletoe extracts also exerted significant effects . In addition, E.coli-activated granulocytes positively stain with Annexin-V and propidium iodide only due to 250 micrograms/ml VT incubation, suggesting that at this concentration burst activity was induced by the physiological activity of granulocytes after microbial ingestion and also by cytotoxic effects . CONCLUSION: Viscotoxins exert yet unknown strong immunomodulatory effects on human granulocytes, which might be of benefit for tumour patients, in addition to their cytotoxic properties.

Arch Dermatol Res, 1999 May, 291(5), 260 - 8
Stratum corneum thiol protease (SCTP): a novel cysteine protease of late epidermal differentiation; Watkinson A; Proteolytic enzymes play crucial roles in the formation of the stratum corneum barrier tissue and in its subsequent maturation . Despite this, the proteases involved in stratum corneum physiology are not well characterized . Hence, studies were performed to identify these proteolytic enzymes present in the peripheral layers of this tissue using a combination of tape stripping and zymography . Using this approach, a novel human cysteine protease was identified and characterized, and named stratum corneum thiol protease (SCTP) . Gelatin zymography revealed that SCTP is composed of two variants with apparent molecular weights of 34 and 35 kDa which do not correspond to any previously described stratum corneum protease . Mechanistically SCTP belongs to the cysteine proteinase class as shown by: (1) acid protease activity, (2) a requirement for mild reducing conditions, and (3) the specific inhibition of activity by E64 and Z-phe-ala-diazomethylketone . Further analysis using concanavalin A affinity chromatography demonstrated that the two 34 and 35 kDa variants are both glycoproteins, which, after removal of the oligosaccharide sidechains with the specific enzyme N-glycopeptidase F, reveal a single active core protease of 32 kDa . SCTP did not crossreact with antibodies raised against the lysosomal cysteine proteases cathepsins B, H or L, thereby distinguishing it from the classical cysteine cathepsins . Localization studies revealed that SCTP is present at all depths in the stratum corneum, thereby precluding microbial contamination as the enzyme source . Moreover, it was also present at all body sites investigated, except for the hyperkeratotic palmoplantar stratum corneum . SCTP was found to be a product of late differentiation in cultured human keratinocytes; the enzyme was synthesized by differentiated calcium-switched cells and secreted into the medium, whereas nondifferentiated basal keratinocytes did not produce this protease . Moreover, human fibroblast cultures did not produce the enzyme, suggesting that SCTP is not produced by the dermis and hence is epidermal specific . The function of SCTP is unknown, but the observed gelatinolytic activity coupled with its secretion into the medium by cultured keratinocytes indicates that physiologically it is responsible for the degradation of extracellular structural proteins . Furthermore, the optimal activity at acid pH suggests that it can function in the acidic environment of the stratum corneum . It remains to be elucidated whether this enzyme has a role in desquamation.

J AOAC Int, 1999 May-Jun, 82(3), 648 - 55
Microbial ranking of porous packaging materials (exposure chamber method), ASTM method: collaborative study; Placencia AM et al.; A collaborative study involving 11 laboratories was conducted to measure the microbial barrier effectiveness of porous medical packaging . Two randomly cut samples from each of 6 commercially available porous materials and one positive and one negative control were tested by one operator in each of 11 laboratories . Microbial barrier effectiveness was measured in terms of logarithm reduction value (LRV), which reflects the log10 microbial penetration of the material being tested . The logarithm of the final concentration is subtracted from that of the initial concentration to obtain the LRV . Thus the higher the LRV, the better the barrier . Repeatability standard deviations ranged from 6.42 to 16.40; reproducibility standard deviations ranged from 15.50 to 22.70 . Materials B(53), C(50), D(CT), and E(45MF) differ significantly from the positive control . The microbial ranking of porous packaging materials (exposure chamber method), ASTM method, has been adopted First Action by AOAC INTERNATIONAL.

Toxicol Sci, 1999 May, 49(1), 86 - 92
Factors contributing to the acute and subchronic adverse respiratory effects of machining fluid aerosols in guinea pigs; Gordon T et al.; Several physical, chemical, and microbial factors are potential contributors to the adverse pulmonary effects associated with occupational exposure to machining fluid aerosols . The present study examined the relative toxicity of 3 major classes of machining fluids (soluble, semi-synthetic, and synthetic) as well as that of unused (fresh) versus used (grab samples taken from manufacturing sites) machining fluids . Pulmonary function and changes in cellular and biochemical indices in bronchoalveolar lavage fluid were examined during and 24 h after exposure, respectively . Statistically significant differences in toxicity were observed in guinea pigs exposed for 3 h to respirable aerosols of unused machining fluids (semi-synthetic > soluble >> synthetic) . In addition, greater toxicity was observed in animals exposed to used, machining fluid aerosols compared to unused fluids . Moreover, within the used machining fluid types, significantly greater adverse effects were observed in animals exposed to poorly maintained fluids (i.e., heavy microbial contamination) versus well-maintained fluids . Changes in biochemical and cellular parameters in bronchoalveolar lavage fluid occurred after a single exposure to 5 mg/m3 of the poorly maintained used machining fluid aerosols . Changes in inflammation but not LDH and protein were observed in animals repeatedly exposed to semi-synthetic machining fluid aerosols . A statistically significant increase in lavage fluid neutrophils was observed in guinea pigs exposed to 5 mg/m3 used, semi-synthetic machining fluid aerosols for 4 weeks . In separate experiments, physicochemical properties of unused machining fluids were found to contribute to the production of adverse effects . Adjustment of the alkaline and hypotonic nature of the unused semi-synthetic machining fluid to isotonicity and pH 7 significantly reduced adverse effects . Together, these findings strongly suggest that multiple factors contribute to the adverse respiratory effects associated with occupational exposure to machining fluid aerosols.

Mol Biotechnol, 1999 Feb, 11(1), 55 - 65
Mechanisms and assessment of lectin-mediated mitogenesis; Kilpatrick DC; The discovery of lectin-mediated mitogenesis by Nowell in 1960 stimulated interest in the properties of lectins while advancing knowledge of immunology . Although some lectins are polyclonal activators both in vitro and in vivo, others may display a broad range of activities toward human lymphocytes . Indeed, the same lectin (e.g., wheat germ agglutinin or Datura lectin) may be mitogenic, comitogenic, or antimitogenic, depending on the experimental conditions . An individual lectin may bind to several glycoproteins on the lymphocyte surface, resulting in interactions that may or may not be functionally relevant, and that may have opposing effects . Studies with lectins and with monoclonal antibodies (MAbs) have established that a surprisingly large variety of cell-surface molecules can influence the initiation and regulation of lymphocyte activation and proliferation . Interactions between lymphocytes and accessory cells are crucial; some signals are cell-mediated, but others depend on soluble cytokines . Mitogenic lectins presumably bind to the T-cell receptor complex and also promote a positive costimulatory signal leading to the synthesis of interleukin 2 and interleukin 2 receptors (IL-2R) . Nonmitogenic, comitogenic, and antimitogenic lectin activities also probably act via accessory molecules involved in costimulation . Plant lectin-animal lymphocyte interactions presumably have no physiological significance, but it is suggested that the former mimics microbial superantigens, which may function in the colonization of host cells . Mitogenic stimulation of lymphocytes can be assessed in several ways . The standard technique measures {3H}-thymidine incorporation into DNA, but nonradioactive procedures are also available.

Int J Food Sci Nutr, 1998 Sep, 49(5), 343 - 52
Lipid content and fatty acid composition in foods commonly consumed by nursing Congolese women: incidences on their essential fatty acid intakes and breast milk fatty acids; Rocquelin G et al.; The fat content and fatty acid (FA) composition of nearly 40 foods, currently consumed by 102 nursing Congolese mothers living in Brazzaville, were determined to assess their impact on mothers' essential fatty acid (EFA) intakes and breast milk FA . Data on mothers' milk FA and dietary habits which allowed food selection were recently published (Rocquelin et al., 1998) . Most foods were locally produced . Food samples were collected at local markets, bleached if necessary to avoid microbial degradation, and stored at +4 degrees C or -20 degrees C . They were lyophilized upon their arrival in the laboratory before lipid analyses . FA composition of food lipids was determined by capillary gas chromatography . Staple diets included low-fat, high-carbohydrate foods (processed cassava roots, wheat bread) and high-polyunsaturated fatty acid (PUFA) foods: soybean oil (high in 18 : 2 n-6 and alpha-18 : 3 n-3), bushbutter (dacryodes edulis), peanuts, avocado (high in fat and 18 : 2 n-6), freshwater and salt-water fish (high in LC n-3 and/or n-6 PUFA), and leafy green vegetables (low in fat but very high in alpha-18 : 3 n-3) . Their frequent consumption by nursing mothers provided enough EFA to meet requirements due to lactation . It also explains why mothers' breast milk was rich in C8-C14 saturated FA (26% of total FA) and in n-6, n-3 PUFA (respectively 15.0% and 2.4% of total FA) highly profitable for breastfed infants' development . From this point of view, dietary habits of Congolese mothers have to be sustained for they are more adequate than most Western-type diets.

Bioinformatics, 1999 May, 15(5), 362 - 9
Interpolated markov chains for eukaryotic promoter recognition; Ohler U et al.; MOTIVATION: We describe a new content-based approach for the detection of promoter regions of eukaryotic protein encoding genes . Our system is based on three interpolated Markov chains (IMCs) of different order which are trained on coding, non-coding and promoter sequences . It was recently shown that the interpolation of Markov chains leads to stable parameters and improves on the results in microbial gene finding (Salzberg et al., Nucleic Acids Res., 26, 544-548, 1998) . Here, we present new methods for an automated estimation of optimal interpolation parameters and show how the IMCs can be applied to detect promoters in contiguous DNA sequences . Our interpolation approach can also be employed to obtain a reliable scoring function for human coding DNA regions, and the trained models can easily be incorporated in the general framework for gene recognition systems . RESULTS: A 5-fold cross-validation evaluation of our IMC approach on a representative sequence set yielded a mean correlation coefficient of 0.84 (promoter versus coding sequences) and 0.53 (promoter versus non-coding sequences) . Applied to the task of eukaryotic promoter region identification in genomic DNA sequences, our classifier identifies 50% of the promoter regions in the sequences used in the most recent review and comparison by Fickett and Hatzigeorgiou ( Genome Res., 7, 861-878, 1997), while having a false-positive rate of 1/849 bp.

Exp Cell Res, 1999 Jun 15, 249(2), 240 - 7
NA22598, a novel antitumor compound, reduces cyclin D1 levels, arrests cell cycle at G1 phase, and inhibits anchorage-independent growth of human tumor cells; Kawada M et al.; NA22598, a novel antitumor compound isolated from a microbial cultured broth, inhibited the growth of human colon cancer DLD-1 cells in suspension cultures (anchorage-independent growth) severalfold more strongly than in substratum-attached monolayer cultures . It arrested the cell cycle progression at early G1 phase under both these culture conditions . Rb phosphorylation, cyclin D1 expression, and cdk2 activation in G1 progression were all inhibited by NA22598, but the amounts of cdk2 and p27 were not affected . Among these effects the inhibition of cyclin D1 expression was most prominent, and NA22598 was found to inhibit the synthesis of cyclin D1 without affecting mRNA expression or protein degradation . p27 binding to cdk2 was more markedly increased in suspension cultures than in attached cultures by NA22598, but the compound had no effect on total p27 . Apparently, the decrease of cyclin D1 induced redistribution of p27 from the cyclin D1/cdk4 to the cyclin E/cdk2 complexes during G1 phase in the suspension cultures . Because p27 is upregulated during suspension culture, a greater amount of it was associated with cyclin E/cdk2, thus producing greater growth inhibition . An agent, like NA22598, which induces the downregulation of cyclin D1 might offer a new anticancer strategy .

Ophthalmology, 1999 Jun, 106(6), 1166 - 70; discussion 1171
Risk factors in microbial keratitis leading to penetrating keratoplasty; Miedziak AI et al.; OBJECTIVE: To determine the characteristics of infectious corneal ulcers at the time of presentation to the cornea specialist associated with a favorable response to medical therapy versus a poor outcome manifested by the need for penetrating keratoplasty for therapy or visual rehabilitation . DESIGN: Retrospective, case-control study . PARTICIPANTS: A total of 162 patient records were reviewed, including the study group of 30 patients and the control group of 132 patients . INTERVENTION: A retrospective review of all cases of microbial keratitis presenting to the Cornea Service between January 1, 1989 and December 31, 1995 was conducted . The cases were divided into two groups . The study group consisted of patients with microbial keratitis who failed medical therapy and required penetrating keratoplasty . The control group included patients with infectious ulcers who responded to medical therapy alone . MAIN OUTCOME MEASURES: The influence of demographics, medical and ocular history, delay in presentation to the primary ophthalmologist or the corneal specialist, topical medications, and contact lens usage were compared . Visual acuity and ulcer characteristics were recorded . The statistical significance was evaluated by the chi-square test for independence and multiple logistic regression . RESULTS: Older age (P=0.001), delay in referral to the corneal specialist (P<0.03), and treatment with topical steroids prior to presentation (P<0.0001) were statistically significant factors associated with the need for penetrating keratoplasty . Steroid use and the delay in referral were correlated . A past history of ocular surgery (P=0.01), poor visual acuity at presentation (P<0.001), and ulcer characteristics, including central location (P<0.0001), large size (P<0.0001), presence of perforation or descemetocele (P<0.0001), limbal involvement (P<0.0001), and hypopyon (P=0.05), were all associated with the need for penetrating keratoplasty . CONCLUSIONS: Older age, delay in referral to the corneal specialist, topical steroid treatment, past ocular surgery, poor vision at presentation, large size, and central location of the ulcer are risk factors for poor outcome of microbial keratitis, as indicated by the need for penetrating keratoplasty.

Phytochemistry, 1999 May, 51(2), 257 - 61
Microbial metabolism of artemisitene; Orabi KY et al.; Studies on the microbial transformation of the sesquiterpene endoperoxide artemisitene have revealed that artemisitene was metabolized by Aspergillus niger (NRRL 599) to yield 11-epi-artemisinin, 9 beta-hydroxydeoxy-11-epi-artemisinin and 9 beta-hydroxy-11-epi-artemisinnin . These metabolites were characterized on the basis of their spectral data.

Science, 1999 Jun 11, 284(5421), 1835 - 7
The nature of the principal type 1 interferon-producing cells in human blood; Siegal FP et al.; Interferons (IFNs) are the most important cytokines in antiviral immune responses . "Natural IFN-producing cells" (IPCs) in human blood express CD4 and major histocompatibility complex class II proteins, but have not been isolated and further characterized because of their rarity, rapid apoptosis, and lack of lineage markers . Purified IPCs are here shown to be the CD4(+)CD11c- type 2 dendritic cell precursors (pDC2s), which produce 200 to 1000 times more IFN than other blood cells after microbial challenge . pDC2s are thus an effector cell type of the immune system, critical for antiviral and antitumor immune responses.

Curr Opin Biotechnol, 1999 Jun, 10(3), 225 - 9
16S rDNA methods in soil microbiology
O'Donnell AG, Gorres HE.
With the introduction of molecular methods, the past decade has seen renewed interest in soil microbiology . New and exciting molecular technologies and the promise of finally opening the microbial black box in soil drive much of this interest . Although these pioneering studies have added much to our knowledge of microbial diversity in soils, it is debatable whether they have as yet advanced our understanding of the relationship between this diversity and soil processes . Hopefully, over the next few years, the knowledge gained from molecular studies will provide a better understanding of microbial communities in soils and lead ultimately to improvements in land management and to the exploitation of the genetic resources of soil.

Curr Opin Biotechnol, 1999 Jun, 10(3), 220 - 4
Molecular approaches to the study of aquatic microbial communities
MacGregor BJ.
Molecular methods for studying microbial communities are still under development . Enormous sequence catalogues can be collected; they must now be related to microbial activities . Messenger RNA detection, fluorescent in situ hybridization, cell sorting, and oligonucleotide array technology are currently being explored . Biases are associated with all these methods, but combined approaches offer checks and balances.

N Y State Dent J, 1999 Apr, 65(4), 32 - 7
Current and future approaches for diagnosis of periodontal diseases; Papapanou PN et al.; Our understanding of the etiology and pathogenesis of periodontal diseases has grown in the recent past, and new findings have led to advances in patient management . This article summarizes important new knowledge and offers a description of traditional and novel diagnostic approaches . These include clinical and radiographic assessments of the periodontal tissues, evaluation of the microbial challenge and the host response, and certain elements of the host genotype that may confer susceptibility to destructive periodontal diseases.

Hum Cell, 1998 Dec, 11(4), 201 - 6
{Control of tumor-related angiogenesis}; Oikawa T; Tumor-related angiogenes is expected to become an important target for improving treatment of cancer, because it plays key roles in tumor growth, invasion and metastasis . We considered that the successful development of such angiostatic treatment depended entirely upon the development of useful anti-angiogenic agents, and attempted to find novel angiogenesis inhibitors by using three in vivo assays, based on an idea of ours . As a result we have demonstrated that different types of agents with low molecular weight including microbial metabolites, cell differentiation modulators like retinoids and steroids, exhibit anti-angiogenic activity, anti-metastatic activity and/or antitumor activity . Taken these findings, an ideal anti-angiogenic agent is discussed.

Am J Physiol, 1999 Jun, 276(6 Pt 1), C1231 - 42
Molecular mechanisms of cytoadherence in malaria; Ho M et al.; Microbial pathogens subvert host adhesion molecules to disseminate or to enter host cells to promote their own survival . One such subversion is the cytoadherence of Plasmodium falciparum-infected erythrocytes (IRBC) to vascular endothelium, which protects the parasite from being removed by the spleen . The process results in microcirculatory obstruction and subsequent hypoxia, metabolic disturbances, and multiorgan failure, which are detrimental to the host . Understanding the molecular events involved in these adhesive interactions is therefore critical both in terms of pathogenesis and implications for therapeutic intervention . Under physiological flow conditions, cytoadherence occurs in a stepwise fashion through parasite ligands expressed on the surface of IRBC and the endothelial receptors CD36, intercellular adhesion molecule-1 (ICAM-1), P-selectin, and vascular adhesion molecule-1 . Moreover, rolling on ICAM-1 and P-selectin increases subsequent adhesion to CD36, indicating that receptors can act synergistically . Cytoadherence may activate intracellular signaling pathways in both endothelial cells and IRBC, leading to gene expression of mediators such as cytokines, which could modify the outcome of the infection.

Eur Respir J, 1999 Apr, 13(4), 835 - 8
Antibiotic use in patients admitted with acute exacerbations of chronic obstructive pulmonary disease; Smith JA et al.; The objective of this report was to document the pattern of initial antibiotic prescribing in acute exacerbations of chronic obstructive pulmonary disease (COPD) in a hospital setting . All episodes of acute exacerbation of COPD, as diagnosed by the admitting doctor, in one hospital in the period January to May 1996, were identified . Case notes were reviewed retrospectively . Cases of radiographic pneumonia, bronchiectasis and incorrectly coded admissions were excluded . Symptoms, microbial cultures and initial antibiotic therapies were recorded . One hundred and fifty-nine patient episodes were identified; 40 were excluded yielding a sample of 119 . Nineteen case notes were unavailable leaving a sample of 100 (84%) episodes . Eighty were treated with antibiotics on admission; amoxycillin was the most frequently prescribed, in 46 (58%) episodes . Of the antibiotic treated group, 42 (53%) patients were given dual therapy, most commonly a macrolide antibiotic with either amoxycillin or a cephalosporin . Intravenous treatment was used in 22 (28%) cases . The duration of intravenous treatment was >48 h in 12 (15%) cases . A total of 76 sputum samples were analysed from 55 patient episodes: 34 (45%) were culture positive . In 15 (27%) patient episodes, antibiotic therapy was changed or instituted on the basis of culture results . These data suggest that antibiotic treatment is not optimal, with overuse of antibiotics, especially intravenous and dual therapy.

Zentralbl Bakteriol, 1999 Apr, 289(2), 147 - 54
Cold-induced augmentation of I blood group antigen interactions with galactophilic lectins; Sudakevitz D et al.; The I antigen appears on human cells in the postnatal period, by addition of N-acetyllactosamine (beta 1-6) branching to the fetal i antigen structure, which is specified by linear oligo N-acetyllactosamine (beta 1-3) chain . Concurrently with the I antigen appearance on adult human erythrocytes most human sera exhibit low levels of anti-I agglutinins . These antibodies induce hemagglutination mainly at low temperatures (4 degrees C) and scantly at body temperature . Therefore they were named "cold agglutinins" . We have used these antibodies and several hemagglutinating galactophilic animal, plant, and microbial lectins that also react with the I antigen, to study whether the cold-favored agglutination of the I antigen-bearing cells is a peculiar property of the anti-I antibodies or a special trait of that antigen . It has been found that the interactions of all of the examined lectins, irrespective of their source, with the adult human erythrocytes significantly increased at 4 degrees C, in contrast to those of the same cells with diverse I-insensitive antibodies and lectins, which were significantly higher at room temperature.

Int Immunol, 1999 Jun, 11(6), 899 - 906
Expansion of neonatal tolerance to self in adult life: I . The role of a bacterial adjuvant in tolerance spread; Grabie N et al.; T cell neonatal tolerance to self evolves perturbation of the Th1/Th2 balance towards Th2-type self-specific T cells . In the current study we have demonstrated that a tolerant state could be extended to another encephalitogenic determinant only if the neonatally tolerizing determinant was co-administered in adult life with an emulsion of Mycobacterium tuberculosis (i.e . complete Freund's adjuvant) . The mechanisms underlying tolerance elicitation and expansion were then explored by an in vitro system in which indirect suppression could be measured . Addition of a tolerizing epitope to splenic T cells from neonatally tolerized animals induced a marked suppression of the anti-MT response . This response could be restored by neutralizing antibodies to IL-4 . In contrast, the neutralizing antibodies to IL-4 had no affect on the response of these cells to the tolerizing determinant . These findings are highly significant not only because they explore the important role of microbial antigens in neonatal tolerance, but also because they distinguish, for the first time, between tolerizing and tolerized T cells.

J Allergy Clin Immunol, 1999 Jun, 103(6), 1153 - 7
A cross-sectional survey of sensitization to Aspergillus oryzae-derived lactase in pharmaceutical workers; Bernstein JA et al.; BACKGROUND: The presence of IgE-mediated occupational respiratory sensitization to microbial enzymes has been well documented in a variety of industries . Aspergillus oryzae -derived lactase is used as a dietary aid for patients with lactose intolerance . OBJECTIVE: In 1993, a cross-sectional survey of 94 pharmaceutical workers exposed to lactase for a mean duration of 23 months and 24 nonexposed recently hired employees was initiated to identify lactase-sensitized workers and potential risk factors that could be used in making recommendations for preventing future cases of lactase sensitization . METHODS: The survey included a physician-administered questionnaire, skin prick testing to lactase enzyme and a panel of common aeroallergens, and spirometry . RESULTS: Twenty-seven of 94 lactase-exposed workers (29%) had positive skin test responses to lactase . These workers were 9 times more likely to have upper or lower respiratory symptoms compared with workers with negative skin test responses . Atopic workers were 4 times more likely to have lactase skin sensitivity than nonatopic workers . However, atopy was not a risk factor for the development of upper and/or lower respiratory symptoms . Lactase skin reactivity was not observed in the 24 nonexposed employees . CONCLUSION: This cross-sectional survey revealed that atopic workers were more likely to have lactase sensitization and that lactase-sensitized workers were more likely to have upper and/or lower respiratory symptoms, but atopy was not a risk factor for upper or lower respiratory symptoms . In spite of these findings, the company allowed only nonatopic, nonlactase-sensitized workers to continue working in high lactase-exposure areas with careful symptom monitoring and use of protective clothing . Although this strategy was successful in total prevention of new cases of occupational respiratory disease after 5 years, the results of this cross-sectional survey do not support exclusion of atopic workers from working with industrial enzymes.

Proc Natl Acad Sci U S A, 1999 Jun 8, 96(12), 6862 - 7
The role of transient hypermutators in adaptive mutation in Escherichia coli; Rosche WA et al.; Microbial populations under nonlethal selection can give rise to mutations that relieve the selective pressure, a phenomenon that has come to be called "adaptive mutation." One explanation for adaptive mutation is that a small proportion of the cells experience a period of transient hypermutation, and that these hypermutators account for the mutations that appear . The experiments reported here investigated the contribution that hypermutators make to the mutations occurring in a Lac- strain of Escherichia coli during selection for lactose utilization . A broad mutational screen, loss of motility, was used to compare the frequency of nonselected mutations in starved Lac- cells, in Lac+ revertants, and in Lac+ revertants carrying yet another nonselected mutation . These frequencies allowed us to calculate that the hypermutating subpopulation makes up approximately 0.06% of the population and that its mutation rate is elevated approximately 200-fold . From these numbers we conclude that the hypermutators are responsible for nearly all multiple mutations but produce only approximately 10% of the adaptive Lac+ mutations.

Biochem J, 1999 Jun 15, 340 ( Pt 3), 793 - 801
Purification, characterization, DNA sequence and cloning of a pimeloyl-CoA synthetase from Pseudomonas mendocina 35; Binieda A et al.; A pimeloyl-CoA synthetase from Pseudomonas mendocina 35 was purified and characterized, the DNA sequence determined, and the gene cloned into Escherichia coli to yield an active enzyme . The purified enzyme had a pH optimum of approximately 8.0, Km values of 0.49 mM for pimelic acid, 0.18 mM for CoA and 0.72 mM for ATP, a subunit Mr of approximately 80000 as determined by SDS/PAGE, and was found to be a tetramer by gel-filtration chromatography . The specific activity of the purified enzyme was 77.3 units/mg of protein . The enzyme was not absolutely specific for pimelic acid . The relative activity for adipic acid (C6) was 72% and for azaleic acid (C9) was 18% of that for pimelic acid (C7) . The N-terminal amino acid was blocked to amino acid sequencing, but controlled proteolysis resulted in three peptide fragments for which amino acid sequences were obtained . An oligonucleotide gene probe corresponding to one of the amino acid sequences was synthesized and used to isolate the gene (pauA, pimelic acid-utilizing A) coding for pimeloyl-CoA synthetase . The pauA gene, which codes for a protein with a theoretical Mr of 74643, was then sequenced . The deduced amino acid sequence of the enzyme showed similarity to hypothetical proteins from Archaeoglobus fulgidus, Methanococcus jannaschii, Pyrococcus horikoshii, E . coli and Streptomyces coelicolor, and some limited similarity to microbial succinyl-CoA synthetases . The similarity with the protein from A . fulgidus was especially strong, thus indicating a function for this unidentified protein . The pauA gene was cloned into E . coli, where it was expressed and resulted in an active enzyme.

J Immunol, 1999 Jun 15, 162(12), 7322 - 9
Virus infection activates IL-1 beta and IL-18 production in human macrophages by a caspase-1-dependent pathway; Pirhonen J et al.; Monocytes and macrophages play a significant role in host's defense system, since they produce a number of cytokines in response to microbial infections . We have studied IL-1 beta, IL-18, IFN-alpha/beta, and TNF-alpha gene expression and protein production in human primary monocytes and GM-CSF-differentiated macrophages during influenza A and Sendai virus infections . Virus-infected monocytes released only small amounts of IL-1 beta or IL-18 protein, whereas 7- and 14-day-old GM-CSF-differentiated macrophages readily produced these cytokines . Constitutive expression of proIL-18 was seen in monocytes and macrophages, and the expression of it was enhanced during monocyte/macrophage differentiation . Expression of IL-18 mRNA was clearly induced only by Sendai virus, whereas both influenza A and Sendai viruses induced IL-1 beta mRNA expression . Since caspase-1 is known to cleave proIL-1 beta and proIL-18 into their mature, active forms, we analyzed the effect of a specific caspase-1 inhibitor on virus-induced IL-1 beta and IL-18 production . The release of IL-1 beta and IL-18, but not that of IFN-alpha/beta or TNF-alpha, was clearly blocked by the inhibitor . Our results suggest that the cellular differentiation is a crucial factor that affects the capacity of monocytes/macrophages to produce IL-1 beta and IL-18 in response to virus infections . Furthermore, the virus-induced activation of caspase-1 is required for the efficient production of biologically active IL-1 beta and IL-18.

J Immunol, 1999 Jun 15, 162(12), 7285 - 93
Generation of recombinant fragments of CD11b expressing the functional beta-glucan-binding lectin site of CR3 (CD11b/CD18); Xia Y et al.; CR3 (Mac-1; alphaMbeta2 integrin) functions as both a receptor for the opsonic iC3b fragment of C3 triggering phagocytosis or cytotoxicity and an adhesion molecule mediating leukocyte diapedesis . Recent reports have suggested that a CR3 lectin site may be required for both cytotoxic responses and adhesion . Cytotoxic responses require dual recognition of iC3b via the I domain of CD11b and specific microbial surface polysaccharides (e.g., beta-glucan) via a separate lectin site . Likewise, adhesion requires a lectin-dependent membrane complex between CR3 and CD87 . To characterize the lectin site further, a recombinant baculovirus (rBv) system was developed that allowed high level expression of rCD11b on membranes and in the cytoplasm of Sf21 insect cells . Six rBv were generated that contained truncated cDNA encoding various CD11b domains . Immunoblotting of rBv-infected Sf21 cells showed that some native epitopes were expressed by five of six rCD11b fragments . Lectin activity of rCD11b proteins was evaluated by both flow cytometry with beta-glucan-FITC and radioactive binding assays with {125I}beta-glucan . Sf21 cells expressing rCD11b that included the C-terminal region, with or without the I-domain, exhibited lectin activity that was inhibited by unlabeled beta-glucan or anti-CR3 mAbs . The smallest rCD11b fragment exhibiting lectin activity included the C-terminus and part of the divalent cation binding region . The beta-glucan binding affinities of the three C-terminal region-containing rCD11bs expressed on Sf21 cell membranes were not significantly different from each other and were similar to that of neutrophil CR3 . These data suggest that the lectin site may be located entirely within CD11b, although lectin site-dependent signaling through CD18 probably occurs with the heterodimer.

Pediatr Dent, 1999 May-Jun, 21(3), 164 - 8
Continuous effect of pit and fissure sealing on S . mutans presence in situ; Mass E et al.; PURPOSE: The effect of sealants on S . mutans presence in situ was investigated . METHODS: Four intact, fully erupted first permanent molars in each of 74 children, aged 6-8 years were required for inclusion in the study . Baseline examination included deft and plaque index . S . mutans presence on occlusal surfaces of the molars was evaluated, using a microbial replica method . Immediately after sealing the first permanent molars on one side, S . mutans presence in situ was re-evaluated, as well as three and six months thereafter . Three months after the initiation of the study, S . mutans presence was evaluated on the molars of the unsealed side, which were consequently sealed and re-evaluated immediately, and three months later . RESULTS: Positive correlation was found between deft scores, plaque indices and microbial replica values, at baseline . Sealing caused a significant reduction in S . mutans levels on the treated occlusal surfaces, in vivo (P < 0.001), which lasted, in most cases, up to six months . CONCLUSIONS: The data suggest that sealants enable a prolonged reduction of S . mutans presence in situ, indicating an additional prevention effect, by reducing one source of dissemination.

J Infect Dis, 1999 Jul, 180(1), 141 - 9
Phenotypically activated gammadelta T lymphocytes in the peripheral blood of patients with tuberculosis; Behr-Perst SI et al.; Surface molecules with the potential relevance for resistance against Mycobacterium tuberculosis were investigated . The expression of lymphocyte function antigen-1, very late antigen (VLA)-4, l-selectin, intercellular adhesion molecule (ICAM)-1, major histocompatibility complex class II, Fas, and CD40 on alphabeta T cells, gammadelta T cells, NK cells, and monocytes of healthy donors and patients with tuberculosis were analyzed . A high activation status of gammadelta T cells and increased levels of soluble ICAM-1 in plasma of patients with tuberculosis versus healthy individuals was detected . Tuberculosis patients with and without an underlying systemic disease could be segregated by differential expression of VLA-4 and ICAM-1 on gammadelta T cells and on monocytes . The composition of peripheral blood mononuclear cells varied slightly, whereas the proportion of monocytes decreased significantly in patients with tuberculosis, compared with healthy controls . The activation phenotype of peripheral gammadelta T cells in patients with tuberculosis emphasizes the role of these T cells in controlling the inflammatory process during tuberculosis and perhaps other microbial infections.

J Microbiol Methods, 1999 May, 36(1-2), 35 - 43
Elevated CO2 alters community-level physiological profiles and enzyme activities in alpine grassland; Mayr C et al.; Plots of an alpine grassland in the Swiss Alps were treated with elevated (680 microl l(-1)) and ambient CO2 (355 microl l(-1)) in open top chambers (OTC) . Several plots were also treated with NPK-fertilizer . Community level physiological profiles (CLPPs) of the soil bacteria were examined by Biolog GN microplates and enzyme activities were determined through the release of methylumbelliferyl (MUF) and methylcoumarin (MC) from MUF- or MC-labelled substrates . A canonical discriminant analysis (CDA) followed by multivariate analysis of variance showed a significant effect of elevated CO2 on the CLPPs both under fertilized and unfertilized conditions . Further, the installation of the OTCs caused significant shifts in the CLPPs (chamber effect) . Of the four enzyme activities tested, the beta-D-cellobiohydrolase (CELase) and N-acetyl-beta-D-glucosaminidase (NAGase) activity were enhanced under elevated CO2 . L-Leucin-7-aminopeptidase (APEase) activity decreased, when the plots received fertilizer . Beta-D-glucosidase (GLUase) remained unaffected . The results suggest effects of elevated CO2 on specific microbial activities even under low mineral nutrient conditions and when bulk parameters like microbial biomass or respiration, which have been investigated on the same site, remain unaffected . The observed medium-term changes point at possible long-term consequences for the ecosystem that may not be specified yet.

J Microbiol Methods, 1999 May, 36(1-2), 21 - 8
Use of biochemical indices in the mediterranean environment: comparison among soils under different forest vegetation; Pinzari F et al.; In the present study, soil biomass activity, organic carbon storage, and turnover times were compared in adjacent mediterranean biotopes with different forest vegetation, to analyze the effects of litter diversity and soil management protocols on microbial decomposition rates . Samples of forest soil from four vegetation types were collected at depths of 0-20 and 20-40 cm in the 'Tenuta Presidenziale di Castelporziano' Reserve on the Tyrrhenian coast, near Rome (Italy) . The samples were incubated under standard laboratory conditions (-33 kPa water tension, and 30 degrees C), in order to compare the microbial activity independently of temperature and humidity . The CO2-C accumulation curves over a 28-d incubation period showed substantially different kinetics between the samples; in particular, soils with above-ground diversity were characterised by high mineralization activity when compared with those sampled under monospecific vegetation . For all the sites, statistically significant linear correlation was observed between nitrogen concentration and potentially mineralizable carbon (r = 0.97), and microbial biomass carbon (Cmic) to total organic carbon (Corg) ratio and the microbial metabolic quotient q(CO2) (r = -0.96) . The q(CO2), indicator of the stability of ecosystems, was enhanced by plant diversity, while the Cmic:Corg ratio was reduced.

Bioorg Med Chem, 1999 Apr, 7(4), 639 - 44
Cysteine protease inhibitors as chemotherapy for parasitic infections; McKerrow JH et al.; Analysis of the evolution, localization and biologic function of papain family cysteine proteases in metazoan and protozoan parasites has provided important and often surprising insights into the biochemistry and cellular function of this diverse enzyme family . Furthermore, the relative lack of redundancy of cysteine proteases in parasites compared to their mammalian hosts makes them attractive targets for the development of new antiparasitic chemotherapy . The treatment of experimental models of parasitic diseases with cysteine protease inhibitors has provided an important 'proof of concept' for the use of cysteine protease inhibitors in vivo . Evidence has now accumulated that cysteine protease inhibitors can selectively arrest replication of a microbial pathogen without untoward toxicity to the host . Furthermore, this can be achieved with reasonable dosing schedules and oral administration of the drug . Initial studies have confirmed the efficacy of cysteine protease inhibitors in treatment of Trypanosoma cruzi, Plasmodium falciparum and Leishmania major . Work on Trypanosoma brucei, the agent of African trypanosomiasis, is preliminary but also promising . Target validation studies have shown that biotinylated or radiolabeled irreversible inhibitors specifically bind to the cysteine protease targets thought to represent the major activity within the parasite . In the case of T . cruzi, the effect of inhibitors appears to be predominantly in blocking protease processing . Transfection studies using variant constructs have supported this model . Finally, the generation of null mutants for the multiple protease genes in Leishmania mexicana has provided the first genetic support for the key role of this enzyme family in parasite virulence . Safety studies in rodents and analysis of uptake of inhibitors by parasites and host cells suggest that the selectivity of inhibitors for the parasite targets may reside in the lack of redundancy of parasite proteases, the higher concentration of host proteases in intracellular compartments, and differential uptake of inhibitors by parasites . Attempts to elicit resistance to cysteine protease inhibitors in parasite cultures suggest that mechanisms of induced resistance are independent of resistance to the traditional antiparasitic agents . This suggests that cysteine protease inhibitors may provide an alternative to traditional therapy in drug-resistant organisms.

Clin Chem Lab Med, 1999 Mar, 37(3), 179 - 86
Mechanisms of antigen presentation; Jensen PE; T-lymphocytes recognize short peptide antigens bound stably to polymorphic major histocompatibility complex (MHC)-encoded glycoproteins expressed on the surface of antigen-presenting cells (APC) . Two general pathways have evolved to generate peptide-MHC complexes . The MHC class II antigen processing pathway provides a mechanism for sampling proteins present in endosomal compartments . CD4+ regulatory T-cells recognize peptides bound to MHC class II molecules, which are selectively expressed in specialized APC that have efficient mechanisms for uptake of microbial antigens, and express costimulatory molecules required for activating naive T-cells . CD8+ T-cells recognize peptides bound to MHC class I molecules . Class I molecules are widely expressed and bind peptides derived from the normal turnover of cellular proteins, providing a mechanism to display a sampling of cellular components to be monitored for abnormalities by cytotoxic T-cells . Specialized accessory proteins influence the efficiency of antigen presentation and the specificity of immune responses through their roles in generating peptides, targeting antigen and MHC glycoproteins to selected intracellular compartments, and by direct participation in the peptide-loading mechanism . It has recently been discovered that some viruses have evolved ways to inhibit or subvert discrete steps in antigen processing, providing a mechanism to evade immune recognition.

J Immunol, 1999 Jun 1, 162(11), 6641 - 9
Mucosal T lymphocyte numbers are selectively reduced in integrin alpha E (CD103)-deficient mice; Schon MP et al.; The mucosal lymphocyte integrin alpha E(CD103)beta 7 is thought to be important for intraepithelial lymphocyte (IEL) localization or function . We cloned the murine integrin gene encoding alpha E, localized it to chromosome 11, and generated integrin alpha E-deficient mice . In alpha E-/- mice, intestinal and vaginal IEL numbers were reduced, consistent with the known binding of alpha E beta 7 to E-cadherin expressed on epithelial cells . However, it was surprising that lamina propria T lymphocyte numbers were diminished, as E-cadherin is not expressed in the lamina propria . In contrast, peribronchial, intrapulmonary, Peyer's patch, and splenic T lymphocyte numbers were not reduced in alpha E-deficient mice . Thus, alpha E beta 7 was important for generating or maintaining the gut and vaginal T lymphocytes located diffusely within the epithelium or lamina propria but not for generating the gut-associated organized lymphoid tissues . Finally, the impact of alpha E deficiency upon intestinal IEL numbers was greater at 3-4 wk of life than in younger animals, and affected the TCR alpha beta+ CD8+ T cells more than the gamma delta T cells or the TCR alpha beta+ CD4+CD8- population . These findings suggest that alpha E beta 7 is involved in the expansion/recruitment of TCR alpha beta+ CD8+ IEL following microbial colonization . Integrin alpha E-deficient mice will provide an important tool for studying the role of alpha E beta 7 and of alpha E beta 7-expressing mucosal T lymphocytes in vivo.

J Immunol, 1999 Jun 1, 162(11), 6552 - 61
Analysis of adjuvant function by direct visualization of antigen presentation in vivo: endotoxin promotes accumulation of antigen-bearing dendritic cells in the T cell areas of lymphoid tissue; Reis e Sousa C et al.; T cell activation requires exposure to processed Ag and signaling by cytokines and costimulatory ligands . Adjuvants are thought to enhance immunity primarily through up-regulation of the latter signals . Here, we explore the effect of the bacterial adjuvant, endotoxin, on Ag presentation by B cells and dendritic cells (DC) . Using an mAb (C4H3) specific for the hen egg lysozyme (HEL) 46-61 determinant bound to I-Ak, we analyze processed Ag expression and the tissue distribution of presenting cells following systemic administration of soluble HEL to mice . In both LPS-responsive and -hyporesponsive mice given endotoxin-containing HEL, B cells rapidly display surface 46-61/I-Ak complexes . In marked contrast, in LPS-hyporesponsive mice, splenic DC show little gain in C4H3 staining . In LPS-responsive animals, interdigitating DC in T cell areas show no staining above background at early times after HEL administration, but C4H3+ DC rapidly accumulate in the outer periarteriolar lymphoid sheaths (PALS) and in follicular areas . Within a few hours, C4H3+ DC appear in the T cell areas, concomitant with a decline in C4H3+ cells in the outer PALS, suggesting migration between these two sites . Endotoxin enhancement of C4H3 staining is seen for both CD8alpha- and CD8alpha+ DC subsets . These data suggest that a major effect of adjuvants is to promote mobilization of Ag-bearing DC to the T areas of lymphoid tissue, and possibly also to enhance Ag processing by these DC . Thus, microbial products promote T cell immunity not only through DC activation for cosignaling, but through improvement in signal 1 delivery.

J Immunol, 1999 Jun 1, 162(11), 6303 - 6
Cutting edge: clonally restricted production of the neurotrophins brain-derived neurotrophic factor and neurotrophin-3 mRNA by human immune cells and Th1/Th2-polarized expression of their receptors; Besser M et al.; Neurotrophins, such as neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF), are potent regulators of neuronal functions . Here we show that human immune cells also produce NT-3 mRNA, secrete BDNF, and express their specific receptors trkB and trkC . The truncated trkB receptor, usually expressed in sensory neurons of the central nervous system, was also constitutively expressed in unstimulated Th cells . Full-length trkB was detectable in stimulated PBMC, B cell lines, and Th1, but not in Th2 and Th0 cell clones . Clonally restricted expression was also observed for trkC, until now not detected on blood cells . The Th1 cytokine IL-2 stimulated production of trkB mRNA but not of trkC, whereas the Th2 cytokine IL-4 enhanced NT-3 but not BDNF mRNA expression . Microbial Ags, which influence the Th1/Th2 balance, could therefore modulate the neurotrophic system and thereby affect neuronal synaptic activity of the central nervous system.

J Nat Prod, 1999 May, 62(5), 726 - 9
Microbial transformation of sesquiterpene lactones by the fungi cunninghamella echinulata and rhizopus oryzae
Barrero AF, Oltra JE, Raslan DS, Saude DA.
Incubations of the fungi Cunninghamella echinulata and Rhizopus oryzae with the sesquiterpene lactones (+)-costunolide (1), (+)-cnicin (2), (+)-salonitenolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5), and (-)-eremantholide C (6) were perfomed . Incubation of 1 with C . echinulata afforded Delta11(13)-dihydrogenation and Delta1(10)-epoxidation products (7-10) . C . echinulata also hydrolyzed the side chain of 2, and transformed 4 into (+)-11alpha,13-dihydrodehydrocostuslactone (12), a new natural product . R . oryzae converted 4 into both Delta11(13)-dihydrogenation and Delta10(14)-epoxidation products (16 and 17) . Both fungi transformed 5 into (-)-16-(1-methyl-1-propenyl)eremantholanolide (13), providing experimental evidence for the biosynthesis of the eremantholide hemiketal unit . Compounds 3 and 6 were not metabolized by either fungus under the test conditions.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1999 May, 87(5), 617 - 27
Persistent periapical radiolucencies of root-filled human teeth, failed endodontic treatments, and periapical scars; Nair PN et al.; OBJECTIVE: This report describes 6 cases that demonstrate persistent periapical radiolucent lesions after conventional root canal treatment . STUDY DESIGN: Six teeth that had conventional root canal treatment or re-treatment with nonresolving periapical radiolucencies underwent periapical surgery . Biopsies were obtained and analyzed descriptively by correlative light and transmission electron microscopy for general features and microbial findings . RESULTS: Three findings were identified: periapical lesions with persisting infection in the apical root canal system (2 cases); a cyst (1 case); and periapical healing by scar tissue formation (2 cases) . CONCLUSIONS: These results confirm previous observations that associated factors in the failure of endodontic treatment include persistent intraradicular infection and periapical cysts . In addition, unresolved periapical radiolucencies may occasionally be due to healing by scar tissue, which may be mistaken as a sign of failed endodontic treatment.

J Appl Microbiol, 1999 May, 86(5), 785 - 95
Application of laser scanning for the rapid and automated detection of bacteria in water samples; Reynolds DT et al.; It is widely accepted that the heterotrophic plate count method may not support the growth of all viable bacteria which may be present within a water sample and that alternative procedures using 'viability markers' may yield additional information . In this study, ChemChrome B (CB), which is converted to a fluorescent product by esterase activity, was used to stain viable bacteria (captured by membrane filtration) from potable water samples . The labelled bacteria from each sample were subsequently enumerated using a novel laser scanning instrument (ChemScan) . Analysis of 107 potable water samples using this procedure demonstrated the presence of a significantly greater number of bacteria than were detected by culture (z-test, P < 0.05) . The mean number of bacteria isolated by culture on R2A agar incubated at 22 degrees C for 7 d was only 25.2% of the total number of viable bacteria detected using the CB/ChemScan viability assay . Further analysis of 81 water samples using a 5-cyano-2,3,4-tolyl-tetrazolium chloride (CTC) viability assay also demonstrated the presence of many viable bacteria which were not capable of growth under the culture conditions employed in this study . However, the results indicate that ChemChrome B has the ability to stain a significantly greater number of heterotrophs than CTC (z-test, P < 0.05) . In contrast, six potable waters were identified in which the CTC viability assay resulted in counts greater than those obtained using CB . The ChemScan instrument was successfully used for rapid and accurate enumeration of labelled micro-organisms, allowing information on the total viable microbial load of a water sample to be determined within 1 h . Furthermore, the ChemScan system has the potential for use in detecting specific organisms labelled with fluorescently-labelled antibodies or nucleic acid probes.

Appl Environ Microbiol, 1999 Jun, 65(6), 2784 - 8
Optimization of simultaneous chemical and biological mineralization of perchloroethylene; Buyuksonmez F et al.; Optimization of the simultaneous chemical and biological mineralization of perchloroethylene (PCE) by modified Fenton's reagent and Xanthobacter flavus was investigated by using a central composite rotatable experimental design . Concentrations of PCE, hydrogen peroxide, and ferrous iron and the microbial cell number were set as variables . Percent mineralization of PCE to CO2 was investigated as a response . A second-order, quadratic response surface model was generated and fit the data adequately, with a correlation coefficient of 0.72 . Analysis of the results showed that the PCE concentration had no significant effect within the tested boundaries of the model, while the other variables, hydrogen peroxide and iron concentrations and cell number, were significant at alpha = 0.05 for the mineralization of PCE . The 14C radiotracer studies showed that the simultaneous chemical and biological reactions increased the extent of mineralization of PCE by more than 10% over stand-alone Fenton reactions.

Appl Environ Microbiol, 1999 Jun, 65(6), 2527 - 33
Microbial control of the culture of Artemia juveniles through preemptive colonization by selected bacterial strains; Verschuere L et al.; The use of juvenile Artemia as feed in aquaculture and in the pet shop industry has been getting more attention during the last decade . In this study, the use of selected bacterial strains to improve the nutritional value of dry food for Artemia juveniles and to obtain control of the associated microbial community was examined . Nine bacterial strains were selected based on their positive effects on survival and/or growth of Artemia juveniles under monoxenic culture conditions, while other strains caused no significant effect, significantly lower rates of survival and/or growth, or even total mortality of the Artemia . The nine selected strains were used to preemptively colonize the culture water of Artemia juveniles . Xenic culture of Artemia under suboptimal conditions yielded better survival and/or growth rates when they were grown in the preemptively colonized culture medium than when grown in autoclaved seawater . The preemptive colonization of the culture water had a drastic influence on the microbial communities that developed in the culture water or that were associated with the Artemia, as determined with Biolog GN community-level physiological profiles . Chemotaxonomical characterization based on fatty acid methyl ester analysis of bacterial isolates recovered from the culture tanks was performed, and a comparison with the initially introduced strains was made . Finally, several modes of action for the beneficial effect of the bacterial strains are proposed.

Appl Environ Microbiol, 1999 Jun, 65(6), 2478 - 84
Detritus-dependent development of the microbial community in an experimental system: qualitative analysis by denaturing gradient gel electrophoresis; van Hannen EJ et al.; Correlations between the biomass of phytoplankton and the biomass of bacteria and between the biomass of bacteria and the biomass of protozoans suggest that there is coupling between these compartments of the "microbial loop." To investigate this coupling on the species level, bacteria and protozoans from untreated lake water inocula were allowed to grow on detritus of the green alga Ankistrodesmus falcatus or the cyanobacterium Oscillatoria limnetica in continuous-flow systems for 1 month . Denaturing gradient gel electrophoresis (DGGE) of the 16S and 18S rRNA genes was used to monitor the development of the bacterial community structure and the eukaryotic community structure, respectively . Nonmetric multidimensional scaling of the DGGE profiles revealed the changes in the microbial community structure . This analysis showed that significantly different bacterial communities developed on the green algal detritus and on the cyanobacterial detritus . Although similar results were obtained for the eukaryotic communities, the differences were not significant . Hence, our findings indicate that the origin of detritus can affect the structure of at least the bacterial community . A phylogenetic analysis of 20 18S ribosomal DNA clones that were isolated from the continuous cultures revealed that many sequences were related to the sequences of bacterivorous protozoans (members of the Ciliophora, Rhizopoda, Amoeba, and Kinetoplastida) . One clone grouped in a recently established clade whose previously described members are all parasites . The affiliations of about 20% of the clones could not be determined.

Appl Environ Microbiol, 1999 Jun, 65(6), 2402 - 8
Vertical distribution of methanogens in the anoxic sediment of Rotsee (Switzerland); Zepp Falz K et al.; Anoxic sediments from Rotsee (Switzerland) were analyzed for the presence and diversity of methanogens by using molecular tools and for methanogenic activity by using radiotracer techniques, in addition to the measurement of chemical profiles . After PCR-assisted sequence retrieval of the 16S rRNA genes (16S rDNA) from the anoxic sediment of Rotsee, cloning, and sequencing, a phylogenetic analysis identified two clusters of sequences and four separated clones . The sequences in cluster 1 grouped with those of Methanosaeta spp., whereas the sequences in cluster 2 comprised the methanogenic endosymbiont of Plagiopyla nasuta . Discriminative oligonucleotide probes were constructed against both clusters and two of the separated clones . These probes were used subsequently for the analysis of indigenous methanogens in a core of the sediment, in addition to domain-specific probes against members of the domains Bacteria and Archaea and the fluorescent stain 4', 6-diamidino-2-phenylindole (DAPI), by fluorescent in situ hybridization . After DAPI staining, the highest microbial density was obtained in the upper sediment layer; this density decreased with depth from (1.01 +/- 0.25) x 10(10) to (2.62 +/- 0.58) x 10(10) cells per g of sediment (dry weight) . This zone corresponded to that of highest metabolic activity, as indicated by the ammonia, alkalinity, and pH profiles, whereas the methane profile was constant . Probes Eub338 and Arch915 detected on average 16 and 6% of the DAPI-stained cells as members of the domains Bacteria and Archaea, respectively . Probe Rotcl1 identified on average 4% of the DAPI-stained cells as Methanosaeta spp., which were present throughout the whole core . In contrast, probe Rotcl2 identified only 0.7% of the DAPI-stained cells as relatives of the methanogenic endosymbiont of P . nasuta, which was present exclusively in the upper 2 cm of the sediment . Probes Rotp13 and Rotp17 did not detect any cells . The spatial distribution of the two methanogenic populations corresponded well to the methane production rates determined by incubation with either {14C}acetate or {14C}bicarbonate . Methanogenesis from acetate accounted for almost all of the total methane production, which concurs with the predominance of acetoclastic Methanosaeta spp . that represented on average 91% of the archaeal population . Significant hydrogenotrophic methanogenesis was found only in the organically enriched upper 2 cm of the sediment, where the probably hydrogenotrophic relatives of the methanogenic endosymbiont of P . nasuta, accounting on average for 7% of the archaeal population, were also detected.

J Nat Prod, 1999 May, 62(5), 761 - 3
Glucosidation of betulinic acid by Cunninghamella species; Chatterjee P et al.; Microbial transformation of the antimelanoma agent betulinic acid (1) was studied . Preparative scale biotransformation with resting-cell suspensions of Cunninghamella species NRRL 5695 resulted in the production of a fungal metabolite of 1, which has been characterized as 28-O-beta-D-glucopyranosyl 3beta-hydroxy-lup-20(29)-en-28-oate (2) based on spectral and enzymic data . The in vitro cytotoxicity assay of metabolite 2 revealed no activity against several human melanoma cell lines.

Electrophoresis, 1999 Apr-May, 20(4-5), 790 - 7
Characterization of periplasmic Escherichia coli protein expression at high cell densities; Franzen B et al.; We have used two-dimensional electrophoresis (2-DE) to analyze changes in protein expression profiles during a microbial cultivation process on an industrial scale . An Escherichia coli strain W31 10 containing the gene for recombinant human growth hormone production was used . Samples were taken at time intervals ranging from fast to slow growth rate (late growth phase at high cell density/starvation) and 2-DE analysis combined with image analysis using the PDQuest software showed significant alterations in expression levels of a number of proteins . Twenty-four protein spots were identified using a combination of matching with SWISS-2DPAGE E . coli map, N-terminal sequence analysis and mass spectrometry matrix-assisted laser desorption/ionization (MALDI) . Two of the most abundant proteins expressed at late growth phase (pI 5.4/28 kDa and pI 5.5/28 kDa) were subjected to N-terminal sequence analysis after electrotransfer of the proteins from a preparative 2-DE gel to polyvinylidene difluoride (PVDF) membrane . Sequence tags of five amino acids in combination with approximate pI and Mr identified both proteins as deoxyribose phosphate aldolase (gene name deoC) . In addition, both spots were subjected to tryptic in-gel digestion and analyzed using MALDI . Peptide mass fingerprints from both spots showed similar MALDI spectra and 10 of 10 tryptic fragments confirmed the identity as deoC . The identification of the acidic variant of deoC on 2-DE gels and the observation of this variant as induced during late growth phase is novel.

Healthc Hazard Mater Manage, 1998 Sep-Oct, 12(1-2), 1 - 7
Water: friend and foe; Analysis of Arabidopsis genome sequence reveals a large new gene family in plants; Wolfson Laboratory for Plant Molecular Biology, School of Biological Sciences, University of Birmingham, UKA detailed analysis of the currently available Arabidopsis thaliana genomic sequence has revealed the presence of a large number of open reading frames with homology to the stigmatic self-incompatibility (S) genes of Papaver rhoeas . The products of these potential genes are all predicted to be relatively small, basic, secreted proteins with similar predicted secondary structures . We have named these potential genes SPH (S-protein homologues) . Their presence appears to have been largely missed by the prediction methods currently used on the genomic sequence . Equivalent homologues could not be detected in the human, microbial, Drosophila or C . elegans genomic databases, suggesting a function specific to plants . Preliminary RT-PCR analysis indicates that at least two members of the family (SPH1, SPH8) are expressed, with expression being greatest in floral tissues . The gene family may total more than 100 members, and its discovery not only illustrates the importance of the genome sequencing efforts, but also indicates the extent of information which remains hidden after the initial trawl for potential genes.

Pol Merkuriusz Lek, 1999 Jan, 6(31), 37 - 40
{The role of bacteria in allergic and pseudoallergic reactions}; Szymaniak L et al.; The variety of microbial pathogenic factors and relations between human and bacterial cells in allergo-inflammatory diseases are presented . A special attention have been paid to sugar-lectin interactions in pseudoallergic processes . The role of specific antibodies as modifiers of basophils releaseability is considered.

Transpl Immunol, 1998 Dec, 6(4), 235 - 41
Procalcitonin: a new marker for diagnosis of acute rejection and bacterial infection in patients after heart and lung transplantation; Hammer S et al.; The aim of the study was to investigate the reliability of procalcitonin (PCT), a new potential marker for detection of bacterial, fungal and protozoal infections, in order to differentiate these from viral infections and early rejections in heart, heart-lung and lung transplanted patients . PCT is a propeptide of calcitonin with unknown origin which is not detectable in plasma of healthy subjects . It increases rapidly and significantly under severe microbial infections . METHODS: PCT plasma levels were measured using an immuno-luminescence assay . C-reactive protein and white blood cells were quantified to validate the PCT values . RESULTS: Increased levels of PCT were found in all transplant patients with bacterial, fungal and protozoal infections . The magnitude of the values were clearly associated with the severity of the infection . Trauma of operation or inflammatory events such as viral infections and rejections did not trigger PCT-production . The release of PCT did not depend on the type of pathogens even though Aspergillum resulted in the highest levels measured . Sensitivity, specificity and prognostic value of PCT for systemic infections were higher than of the other parameters investigated . CONCLUSION: PCT is a highly specific analyte which shows significant diagnostic validities when nonviral infections are compared with rejection episodes . PCT discriminates between inflammatory events such as rejection or viral infections and nonviral-infections including bacterial, fungal and protozoal infections . The half-life of PCT is 24 h indicating clearly a competent antibiotic treatment . Unnecessary antibiotic therapy can be avoided due to the early exclusion of bacterial and fungal infections.

Med Tr Prom Ekol, 1999, (4), 15 - 9
{The role of biological factors in the formation of working conditions at agricultural enterprises}; Tsapko VG et al.; The analysis of the results of hygienic studies carried out in agricultural sector: cattlebreeding farms, fodder production plants, the enterprises of process raw materials-meat refinery, allowed to consider biological factors as the major adversity factor . The main of them are organic dust of composite contents, microbial flora . It's determine the possible effect of physical, chemical and biological factors . The analyses consent to formulate the basic principles and priorities in researches connected with new biotechnologies.

J Neurosci . 1999 Jun 1;19(11):RC7.
Exacerbation of facial motoneuron loss after facial nerve transection in severe combined immunodeficient (scid) mice; Serpe CJ et al.; The immune system functions to protect an organism against microbial infections and may be involved in the reparative response to nerve injury . The goal of this study was to determine whether the immune system plays a role in regulating motoneuron survival after a peripheral nerve injury . After a right facial nerve axotomy, facial motoneuron (FMN) survival in C.B-17 (+/+) wild-type mice was found to be 87 +/- 3.0% of the unaxotomized left side control . In contrast, facial nerve axotomy in C.B-17 (-/-) severe combined immunodeficient (scid) mice, lacking functional T and B lymphocytes, resulted in an average FMN survival of 55 +/- 3.5% relative to the unaxotomized left side control . This represented an approximately 40% decrease in FMN survival compared with wild-type controls . The reconstitution of scid mice with wild-type splenocytes containing T and B lymphocytes restored FMN survival in these mice to the level of the wild-type controls . These results suggest that immune cells associated with acquired immunity play a role in regulating motoneuron survival after a peripheral nerve injury.

Emerg Infect Dis, 1999 May-Jun, 5(3), 346 - 52
Iron loading and disease surveillance; Weinberg ED; Iron is an oxidant as well as a nutrient for invading microbial and neoplastic cells . Excessive iron in specific tissues and cells (iron loading) promotes development of infection, neoplasia, cardiomyopathy, arthropathy, and various endocrine and possibly neurodegenerative disorders . To contain and detoxify the metal, hosts have evolved an iron withholding defense system, but the system can be compromised by numerous factors . An array of behavioral, medical, and immunologic methods are in place or in development to strengthen iron withholding . Routine screening for iron loading could provide valuable information in epidemiologic, diagnostic, prophylactic, and therapeutic studies of emerging infectious diseases.

J Food Prot, 1999 May, 62(5), 520 - 5
Reliability of an ordinal rating system for assessing the amount of mud and feces (tag) on cattle hides at slaughter; Jordan D et al.; A study was conducted to provide a quantitative description of the amount of tag (mud, soil, and bedding) adhered to the hides of feedlot beef cattle and to appraise the statistical reliability of a subjective rating system for assessing this trait . Initially, a single rater obtained baseline data by assessing 2,417 cattle for 1 month at an Ontario beef processing plant . Analysis revealed that there was a strong tendency for animals within sale-lots to have a similar total tag score (intralot correlation = 0.42) . Baseline data were summarized by fitting a linear model describing an individual's total tag score as the sum of their lot mean tag score (LMTS) plus an amount representing normal variation within the lot . LMTSs predicted by the linear model were adequately described by a beta distribution with parameters nu = 3.12 and omega = 5.82 scaled to fit on the 0-to-9 interval . Five raters, trained in use of the tag scoring system, made 1,334 tag score observations in a commercial abattoir, allowing reliability to be assessed at the individual level and at the lot level . High values for reliability were obtained for individual total tag score (0.84) and lot total tag score (0.83); these values suggest that the tag scoring system could be used in the marketing and slaughter of Ontario beef cattle to improve the cleanliness of animals presented for slaughter in an effort to control the entry of microbial contamination into abattoirs . Implications for the use of the tag scoring system in research are discussed.

J Anim Sci, 1999 May, 77(5), 1295 - 305
Effects of increasing ruminally degraded nitrogen and abomasal casein infusion on net portal flux of nutrients in yearling heifers consuming a high-grain diet; Krehbiel CR et al.; Seven Meat Animal Research Center (MARC) III heifers (410+/-25 kg) fitted with hepatic portal, mesenteric venous, carotid catheters, and an abomasal cannula were used in a 7 x 5 incomplete Latin square design experiment . The objective was to evaluate the effects of increasing levels of ruminally degradable N (RDN) with or without the addition of abomasally infused casein on portal-drained visceral (PDV) flux of nutrients . Treatments consisted of dietary CP percentage levels of 9.5 (control), control plus .72% dietary urea (11.5U), control plus 1.44% dietary urea (13.5U), control plus abomasally infused casein (250 g/d; 11.5C), or control plus .72% dietary urea and abomasally infused casein (250 g/d; 13.5UC) . All diets contained (DM basis) 80% ground corn, 15% corn silage, and 5% dry supplement and were provided for ad libitum consumption . Nitrogen intake increased (linear, P < .001) as CP increased from 9.5 to 13.5% . Portal-drained visceral release of ammonia N increased (linear, P < .10) as RDN increased, and was greater (P < .05) when protein was fed compared with heifers fed control (P < .10) . Urea N removal by PDV was not affected ( P > . 10) by level of RDN but was greatest when 11.5C was fed and least when 13.5UC was fed . Net alpha-amino N (AAN) release by PDV was greatest when 13.5UC was fed (309 mmol/h), least when 9.5% CP was fed (112 mmol/h), and intermediate for the other groups (205 to 252 mmol/h) . These data suggest that removal of N by the PDV may promote microbial protein synthesis when dietary RDN is low . When RDN needs have been met and amino acids are deficient for the host, escape protein should be fed to increase amino acid absorption.

J Anim Sci, 1999 May, 77(5), 1113 - 9
Physiological changes and digestive capabilities of newly received feedlot cattle; Loerch SC et al.; Newly arrived feedlot calves undergo numerous stressors that result in 1) transient endocrine responses, 2) altered products of energy and protein metabolism, 3) changes in appetite and growth rate, 4) possible limited compromise of digestive and rumen function, and 5) a challenged immune system . The most consistent endocrine and metabolic responses to marketing, transport, and feedlot adaptation are seen with cortisol and epinephrine . In contrast to earlier work done with indirect in vitro gas production measurements, recent research has shown that the ruminal microbial population is able to effectively digest available substrate immediately following a calfs weaning, trucking, and 24 h of feed and water deprivation . Additionally, a period of feed and water deprivation up to 72 h coupled with 8 h of trucking does not reduce the concentration or total numbers of either the viable cellulolytic or total bacteria present in the rumen of newly weaned or feedlot-adapted calves . However, ruminal volume, DM, total weight of ruminal contents, and total protozoal numbers decrease as duration of feed deprivation increases . To compensate for the reduced DMI that occurs in the first 2 wk after arrival at the feedlot, increased nutrient density is needed to meet an animal's requirements for nutrients . Limited data suggest that newly arrived calves prefer a diet that is similar in moisture and texture to feeds with which they are familiar . Additionally, modification of the stress-associated behavior using trainer animals may improve the feed intake of newly received calves and may reduce calf morbidity.

Surv Ophthalmol, 1999 Mar-Apr, 43(5), 379 - 96
Vasculitic peripheral ulcerative keratitis; Messmer EM et al.; The onset of peripheral ulcerative keratitis in the course of a connective tissue disorder, such as rheumatoid arthritis, relapsing polychondritis, or systemic lupus erythematosus, may reflect the presence of potentially lethal systemic vasculitis . Moreover, peripheral ulcerative keratitis may be the first sign of systemic necrotizing vasculitis in patients with Wegener's granulomatosis, polyarteritis nodosa, microscopic polyangiitis, or Churg-Strauss syndrome . Although the exact pathogenesis of this severe corneal inflammation and destruction is not well understood, evidence points to a dysfunction in immunoregulation with immune complexes formed in response to autoantigens or to some unknown microbial antigen depositing in scleral and limbal vessels . These events lead to changes that are mainly responsible for the resulting tissue damage . In pauci-immune vasculitides positive for antineutrophil cytoplasmic antibodies, cell-mediated cytotoxicity may play an important role in the pathogenesis of peripheral ulcerative keratitis . Untreated systemic conditions such as those mentioned above may carry a grave prognosis for the eye and may also be life-threatening . Immunosuppressive therapy with corticosteroids and cytotoxic agents is, we believe, mandatory in the treatment of these multisystem disorders associated with vasculitic peripheral ulcerative keratitis.

Infect Dis Clin North Am, 1999 Jun, 13(2), 427 - 47, x
Neutrophil and endothelial cell interactions in sepsis . The role of adhesion molecules; Parent C et al.; Although adhesion molecules present on circulating neutrophils and endothelial cells are essential for normal host defense, generalized activation of these molecules has been implicated in the inflammatory tissue injury occurring during sepsis and septic shock . A review of both preclinical and clinical studies suggests, however, that although these molecules mediate tissue injury related to a variety of microbial and host inflammatory mediators, their predominant role during sepsis with infection is a protective one.

Eksp Klin Farmakol, 1999 Mar-Apr, 62(2), 43 - 7
{The polyclonal nature of the immune response to xenobiotics and endobiotics}; Bykova AA; The results of many experiments and clinical observations showed that each chemical agent and its metabolites introduced into or mobilized in the organism act, along with others, on the lymphoid cells obligatorily inducing a polyclonal immune response directed at restoration of the chemism of the internal medium . The specificity of the response is attested by the absence of intensification of the immune rosette formation phenomenon in administration of a chemical agent of a different structure into the animal, as well as when erythrocytes, sensibilized by some other chemical agent not introduced or freed in the organism is used in the reaction . That an excess of the agent saturates the receptors of cells only specific of its clone testifies to the monospecificity of each of the lymphocyte clones . Our data are in agreement in this respect with one of the main postulates of immunology on the narrow specialization and strict manner of clone formation of the lymphocyte B-pool . Our data may possibly set the way for understanding the phenomenon of the polyclonal character of the immune response to various antigens and effects . We studied intensified immune responses specific of endobiotics, in exposure of the lymphocytes of animal organs to the effect fo PGA, tuberculin, antiglobulin sera, foreign protein, genetically foreign cells (sheep erythrocytes), microbial antigens and toxins . This, possibly, underlies the well known phenomenon of synthesis of nonspecific immunoglobulins in the organism in response to the effect of an antigen, the mechanism of which is still not clear.

Arch Biochem Biophys, 1999 Jun 1, 366(1), 125 - 30
Neutrophil myeloperoxidase is a potent and selective inhibitor of mast cell tryptase; Cregar L et al.; Myeloperoxidase (MPO) is an important component of the neutrophil response to microbial infection . In this paper we report an additional activity of MPO, the potent and selective inhibition of human mast cell tryptase . MPO inhibits human mast cell tryptase in a time-dependent manner with an IC50 of 16 nM at 1 h . In contrast, MPO does not inhibit trypsin, thrombin, plasmin, factor Xa, elastase, or cathepsin G . It is the native protein conformation of MPO and not its enzyme activity that is responsible for tryptase inhibition . Heparin, at high concentrations, can prevent the inhibition of tryptase by MPO . We have shown by size-exclusion chromatography that MPO promotes the dissociation of active tryptase tetramer to inactive monomer . These data suggest that MPO inhibits tryptase by interfering with the heparin stabilization of tryptase tetramer . We have previously shown that lactoferrin (another neutrophil-associated protein) also inhibits tryptase activity by a similar mechanism . The finding that MPO is a potent inhibitor of tryptase lends further support to the hypothesis that neutrophil proteins, such as MPO and lactoferrin, may play a regulatory role as endogenous suppressers of tryptase enzyme activity .

Anal Biochem, 1999 Jun 1, 270(2), 220 - 30
Characterization of metabolites in intact Streptomyces citricolor culture supernatants using high-resolution nuclear magnetic resonance and directly coupled high-pressure liquid chromatography-nuclear magnetic resonance spectroscopy; Abel CB et al.; A novel NMR spectroscopic approach to the direct biochemical characterization of bacterial culture broths is presented . A variety of one- and two-dimensional 1H NMR spectroscopic methods were used to characterize low-molecular-weight organic components of broth supernatants from cultures of Streptomyces citricolor . By applying 1H NMR spectroscopy to analyze whole, untreated culture supernatants, it was possible to identify and monitor simultaneously a range of media substrates and excreted metabolites . Identified metabolites include 2-phenylethylamine, trehalose, succinate, acetate, uridine, and aristeromycin, a secondary metabolite with antibiotic properties . Directly coupled HPLC-NMR spectroscopy was also applied to the analysis of broth supernatants for the first time, to aid spectral assignments, especially where signals were extensively overlapped in the 1H NMR spectra of the whole broth mixtures . Two-dimensional NMR methods such as 1H-1H correlation spectroscopy, 1H-13C heteronuclear single quantum correlation, and 1H-13C heteronuclear multiple bond correlation aided the structure elucidation and peak assignments of individual components in the mixtures by providing information on 1H-1H coupling networks and 13C chemical shifts . This work shows that high-resolution NMR spectroscopic methods provide a rapid and efficient means of investigating microbial metabolism directly without invasive or destructive sample pretreatment .

J Microbiol Methods, 1999 Apr, 35(3), 225 - 35
Characterization of microbial communities using randomly amplified polymorphic DNA (RAPD); Franklin RB et al.; Similarity among a number of aquatic microbial communities was examined using randomly amplified polymorphic DNA (RAPD), a common polymerase chain reaction (PCR)-based DNA fingerprinting technique . After amplification of whole-community DNA extracts, the PCR products were resolved by agarose gel electrophoresis and the band patterns compared to determine percent similarity . Twelve different primers were used to amplify approximately 100 fragments (total) from each DNA sample; the bands were scored as present or absent and the similarity between each sample was determined using Jaccard's coefficient . From this information . dendrograms were constructed and a bootstrapping procedure was used to assess how well supported the tree topologies were . Principal component analyses were also conducted as a means of visualizing the relationships among samples . Results obtained for two different experimental systems (a pair of tidal creeks and several wells in a shallow groundwater aquifer) correlated well with the temporal and spatial variations in environmental regime at the sites confirming that arbitrarily primed PCR-based DNA fingerprinting techniques such as RAPD are useful means of discriminating among microbial communities and estimating community relatedness . Moreover, this approach has several advantages over other DNA-based procedures for whole-community analysis; it is less laborious and uses smaller quantities of DNA, making it amenable to sample-intensive monitoring, and it does not depend on culturing or the use of selective PCR primers.

Prim Dent Care, 1996 Sep, 3(2), 53 - 6
Endodontic disease: development and treatment; Walker RT; Endodontic disease requires the involvement of micro-organisms . Microbial contamination of the pulp-dentine complex occurs in a number of different ways . The loss of integrity of teeth and the penetration of the pulp-dentine complex by a mixed microbial flora characterises the disease processes which can lead to pulpal and periradicular inflammation and infection . Endodontology is that part of dental science which deals with the biology of the pulp-dentine complex in health and disease, an understanding of which is a prerequisite to the provision of sound conservative care . The principles of endodontic treatment require the control of micro-organisms and potential nutrients by the microbial decontamination of teeth, the denaturing of protein and the sealing of dentine to prevent recolonisation.

Can J Gastroenterol, 1999 Apr, 13(3), 229 - 34
Understanding disease outcome following acquisition of Helicobacter pylori infection during childhood; Day AS et al.; Helicobacter pylori causes chronic active (type B) gastritis in the overwhelming majority of infected individuals . The relative contribution of virulence factors in the bacterium and host responses to the microbial infection in determining which subjects will go on to develop complications - such as peptic ulceration, gastric cancers and gastric lymphomas - is the subject of current investigative activities.

J Leukoc Biol, 1999 May, 65(5), 665 - 70
Superantigens augment antigen-specific Th1 responses by inducing IL-12 production in macrophages; Bright JJ et al.; Superantigens (SAg) are microbial proteins that mediate antigen-presenting cell (APC)-T cell interaction by cross-linking MHC class II molecules with subsets of TcRVbeta . SAgs are implicated in the pathogenesis of several infectious, inflammatory, and autoimmune diseases . In this study, we examined the influence of SEB on interleukin-12 (IL-12) production and the activation of antigen-specific Th1 responses . Addition of SEB augmented the antigen-induced proliferation of HS-17, a murine MBPp91-103 peptide-specific TcRVbeta6+ CD4+ Th1 clone . SEB augments HS-17 T cell proliferation through its interaction with IA(S) molecules on macrophages, but not with the TcRVbeta6 on HS-17 cells . On binding to IA(S), SEB induces IL-12 production in macrophages, which in turn augments antigen-induced proliferation of HS-17 T cells . Treatment with anti-IA(S) nmAb 10-3.6 inhibited the antigen- and SEB-induced IL-12 production and T cell proliferation . These results suggest that SAgs augment antigen-specific T cell responses by inducing IL-12 production in macrophages.

Acta Microbiol Immunol Hung, 1999, 46(1), 25 - 32
Chromium-resistant soil actinomycetes: their tolerance to other metals and antibiotics; Basu M et al.; Chromium occurs widely in most soils, but generally in trace amounts . Actinomycetes, one of the important components of the microbial population in soils interact with a variety of metals including chromium . This study was aimed to evaluate the tolerance of soil actinomycetes to Cr6+, other metals and antibiotics . Thirty-two actinomycete isolates were screened for their tolerance to Cr6+ on tryptone yeast extract agar medium supplemented with Cr6+ at concentrations ranging from 100 to 2000 micrograms ml-1 . Thirteen Cr-tolerant isolates were selected on the basis of their growth at the highest concentration, but their performance was not satisfactory in Cr6+ containing liquid salts medium . Resistance of these isolates to other metals and antibiotics was assessed using agar-cup assay and disc diffusion technique, respectively . The sequence of metal toxicity for the actinomycete isolates was in the order Hg2+ > Ni2+ > Cu2+ > Co2+ > Cd2+, but the Cr6+ resistance of the isolates could not be correlated with their antibiotic-resistance profile.

Ecotoxicol Environ Saf, 1999 May, 43(1), 83 - 90
Effects of organic pollutants on soil microbial activity: the influence of sorption, solubility, and speciation; Welp G et al.; The Fe(III) reduction test was used to measure the toxicity of 12 organic chemicals {dichlorophenoxyacetic acid (2,4-D), trichlorophenoxyacetic acid (2,4,5-T), atrazine, picloram, 4-chlorobenzeneamine, pentachlorophenol (PCP), hexachlorobenzene (HCB), 1,1-bis-4-chlorophenyl-2,2,2-trichloroethane (DDT), trichloroethene, benzene, phenol, linear alkylbenzenesulfonate (LAS)} . The different inherent toxicity of the pollutants is strongly modified by interactions with the soils . The total amounts that cause 10, 50, and 90% inhibitions (effective doses, ED10, ED50, ED90) can be statistically related to soil parameters that control the sorption and solubility of the chemicals . Sorption experiments with 2,4-D, 2,4,5-T, PCP, and LAS confirm that the degree of sorption and the concentration in the soil solution are important for potential toxic effects . However, toxic solution concentrations of a chemical (effective concentrations, EC10, EC50, EC90) also vary considerably . For some chemicals the influence of soil pH on their speciation in the soil solution is mainly responsible for this, e.g., the transformation from anionic to nonionic species with decreasing pH . The nonionic species of 2,4-D, 2,4,5-T, and PCP formed under acidic conditions are more toxic than the anionic species . Thus, depending on the chemical parameters of the soils that determine the degree of sorption and the speciation of toxicants in the liquid phase, soils either can "buffer" high loads of toxicants or can be very sensitive toward contamination .

Am J Physiol, 1999 May, 276(5 Pt 1), C1139 - 47
P2Z/P2X7 receptor-dependent apoptosis of dendritic cells; Coutinho-Silva R et al.; Macrophages and thymocytes express P2Z/P2X7 nucleotide receptors that bind extracellular ATP . These receptors play a role in immune development and control of microbial infections, but their presence on dendritic cells has not been reported . We investigated whether extracellular ATP could trigger P2Z/P2X7 receptor-dependent apoptosis of dendritic cells . Apoptosis could be selectively triggered by tetrabasic ATP, since other purine/pyrimidine nucleotides were ineffective, and it was mimicked by the P2Z receptor agonist, benzoylbenzoyl ATP, and blocked by magnesium and the irreversible antagonist, oxidized ATP . RT-PCR analysis confirmed the mRNA expression of the P2Z/P2X7 receptor and the absence of P2X1 . Caspase inhibitors and cycloheximide had only a partial effect on the apoptosis, suggesting that a caspase-independent mechanism may also be operative . Brief treatment with ATP led to an increase in the intracellular calcium concentration and permeabilization of the plasma membrane to Lucifer yellow, which diffused throughout the dendritic cell cytosol . Other small extracellular molecules may thus attain a similar intracellular distribution, perhaps activating endogenous proteases that contribute to initiation of apoptosis.

Haematologica, 1999 May, 84(5), 452 - 60
Antithrombin replacement in patients with sepsis and septic shock; Giudici D et al.; Sepsis is a frequent complication of critically ill patients and its incidence is increasing . Currently, septic shock is the most common cause of death in non-coronary intensive care units . Over the last 10 to 15 years, new antibiotics and increasingly sophisticated critical care have had little impact on the mortality rate of septic shock . The Italian SEPSIS Study, carried out in 99 intensive care units in 1994, reported mortality rates of 52% and 82% for severe sepsis and septic shock respectively . New therapeutic approaches aimed at neutralizing microbial toxins and modulating host mediators have shown some efficacy in large clinical trials and/or in animal models, but to date, no therapy of sepsis aimed at reversing the effects of bacterial toxins or of harmful endogenous mediators of inflammation has gained widespread clinical acceptance . Because of the strong association of severe sepsis with a state of activation of blood coagulation and of the potential role of capillary thrombosis in the development of the multiple organ dysfunction syndrome, anticoagulant agents have been tested in the setting of septic shock . However, neither administration of heparin nor of active site-blocked factor Xa or of anti-tissue factor antibodies have proven effective in preventing deaths due to septic shock in animal models . In contrast, infusion of antithrombin, protein C, or tissue factor pathway inhibitor all resulted in a significant survival advantage in animals receiving lethal doses of E . Coli . Antithrombin concentrates have been used in a significant number of critically ill patients . A double-blind, placebo controlled study carried out in 3 italian intensive care units has recently shown that the administration of antithrombin aimed to normalize plasma antithrombin activity had a net beneficial effect on 30-day survival of patients requiring respiratory and/or hemodynamic support because of severe sepsis and/or post-surgery complications.

Wei Sheng Yan Jiu, 1997 Jul, 26(4), 226 - 31
{Study on the best sampling time and the time distribution of atmospheric bacterial particle}; Hu Q; The changes of atmospheric bacterial particle concentrations in three areas--Beijing, Tianjin and Shenyang, were investigated in different seasons and period of one day . The samplers used in this study were MF-45 and HTK-201 air microbial samplers . The results showed that the concentrations of atmospheric bacterial particle in Beijing and Tianjin are higher in spring than those in other seasons . They are 2053/m3 and 2556/m3 respectively in spring, 995/m3 and 1064/m3 respectively in summer . The concentrations of atmospheric bacterial particle in Shenyang is higher in autumn (10108/m3) and lower in winter (1294/m3) . The changes of atmospheric bacterial particle concentrations have two peak values during a day . The two high peak values are at 6:00 to 7:00 and 18:00, while the two low values are at 11:00 to 13:00 and 1:00 to 2:00 . We sampled the atmospheric bacterial particles at 4 different combinations of sampling time in the three cities . They were 12, 8, 6 and 4 times a day . The sampling time combination was analyzed by mathematical statistics according to the results . The best sampling time was decided by the statistics results and time distribution character of atmospheric bacterial particle concentration in different seasons and period of one day . The concentration of atmospheric bacterial particle should be detected in the middle month of the four seasons: January, April, July and October . Sampling time at 7:00, 10:00, 13:00, 16:00, 19:00, 22:00, 1:00 and 4:00 could be selected for 8 times sampling a day . The sampling time sequence should be at 5:00, 11:00, 17:00 and 23:00 for 4 times sampling a day . The four times sampling at daytime in spring and fall should be at 6:00, 9:00, 12:00 and 19:00; 5:00, 9:00, 13:00 and 17:00 in summer; 7:00, 10:00, 13:00 and 16:00 in winter.

J Clin Microbiol, 1999 Jun, 37(6), 2080 - 3
Variation in Microbial Identification System accuracy for yeast identification depending on commercial source of Sabouraud dextrose agar; Kellogg JA et al.; The accuracy of the Microbial Identification System (MIS; MIDI, Inc . ) for identification of yeasts to the species level was compared by using 438 isolates grown on prepoured BBL Sabouraud dextrose agar (SDA) and prepoured Remel SDA . Correct identification was observed for 326 (74%) of the yeasts cultured on BBL SDA versus only 214 (49%) of yeasts grown on Remel SDA (P < 0.001) . The commercial source of the SDA used in the MIS procedure significantly influences the system's accuracy.

Pharm, Sci . Technol . Today . 1999 May, 2(5), 197 - 204
Coated dosage forms for colon-specific drug delivery; Leopold CS; Coating materials used in the manufacture of colon-specific solid oral dosage forms include polymers with a pH-dependent solubility that rely on the difference in pH between the small and the distal large intestine (pH-controlled release), polymers with a slow or pH-dependent rate of swelling, dissolution or erosion that take advantage of the constant small intestinal transit time (time-controlled release), polymers that are degradable by the microbial enzymes in the colon (enzyme-controlled release) and polymers that form firm layers that are destroyed by an increase of the luminal pressure in the colon caused by peristaltic waves (pressure-controlled release) . This review gives an overview of coated dosage forms that have been developed to achieve colon specificity.

J Bacteriol, 1999 May, 181(10), 3003 - 9
Growth of Azospirillum irakense KBC1 on the aryl beta-glucoside salicin requires either salA or salB; Faure D et al.; The rhizosphere nitrogen-fixing bacterium Azospirillum irakense KBC1 is able to grow on pectin and beta-glucosides such as cellobiose, arbutin, and salicin . Two adjacent genes, salA and salB, conferring beta-glucosidase activity to Escherichia coli, have been identified in a cosmid library of A . irakense DNA . The SalA and SalB enzymes preferentially hydrolyzed aryl beta-glucosides . A Delta(salA-salB) A . irakense mutant was not able to grow on salicin but could still utilize arbutin, cellobiose, and glucose for growth . This mutant could be complemented by either salA or salB, suggesting functional redundancy of these genes in salicin utilization . In contrast to this functional homology, the SalA and SalB proteins, members of family 3 of the glycosyl hydrolases, show a low degree of amino acid similarity . Unlike SalA, the SalB protein exhibits an atypical truncated C-terminal region . We propose that SalA and SalB are representatives of the AB and AB' subfamilies, respectively, in glycosyl hydrolase family 3 . This is the first genetic implication of this beta-glucosidase family in the utilization of beta-glucosides for microbial growth.

Life Sci, 1999, 64(16), 1435 - 45
Cloning and cytotoxicity of fusion proteins of EGF and angiogenin; Yoon JM et al.; Targeted toxins represent a new approach to specific cytocidal therapy . Immunotoxins based on plant and microbial toxins are very immunogenic . To develop a targeted therapy that is less immunogenic and easily invades target tissues, four fusion proteins containing human angiogenin targeted by human EGF have been constructed . EGF is a single chain polypeptide, which binds to epidermal growth factor receptor (EGFR) and is known to be internalized by endocytosis . Angiogenin has been separately fused either at the amino terminus or the carboxyl terminus of EGF via linkers, giving rise to angiogenin-gly-EGF, angiogenin-(gly)4ser-EGF and EGF-angiogenin, EGF-gly-angiogenin, respectively . The fusion proteins were over-expressed in Escherichia coli and purified from periplasmic eluents by affinity chromatography . EGF-angiogenin and EGF-gly-angiogenin maintained receptor-binding activity of EGF and RNase activity of angiogenin in a single peptide and actively inhibited growth of human EGFR-positive target cells in culture . They are expected to have a very low immunogenic potential in humans because of their endogenous origin and also to have another potential therapeutic advantage because these fusion proteins may have overcome conventional immunotoxin and possess increased ability to penetrate because of their small size.

Proc Soc Exp Biol Med, 1999 May, 221(1), 80 - 6
Dietary intrinsic phytate protects colon from lipid peroxidation in pigs with a moderately high dietary iron intake; Porres JM et al.; High iron consumption has been proposed to relate to an increase in the risk of colon cancer, whereas high levels of supplemental sodium phytate effectively reduce iron-induced oxidative injury and reverse iron-dependent augmentation of colorectal tumorigenesis . However, the protective role of intrinsic dietary phytate has not been determined . In this study, we examined the impact of removing phytate present in a corn-soy diet by supplemental microbial phytase on susceptibility of pigs to the oxidative stress caused by a moderately high dietary iron intake . Thirty-two weanling pigs were fed the corn-soy diets containing two levels of iron (as ferrous sulfate, 80 or 750 mg/kg diet) and microbial phytase (as Natuphos, BASF, Mt . Olive, NJ, 0 or 1200 units/kg) . Pigs fed the phytase-supplemented diets did not receive any inorganic phosphorus to ensure adequate degradation of phytate . After 4 months of feeding, liver, colon, and colon mucosal scrapings were collected from four pigs in each of the four dietary groups . Colonic lipid peroxidation, measured as thiobarbituric acid reacting substances (TBARS), was increased by both the high iron (P< 0.0008) and phytase (P< 0.04) supplementation . Both TBARS and F2-isoprostanes, an in vivo marker of lipid peroxidation, in colonic mucosa were affected by dietary levels of iron (P< 0.03) . Mean hepatic TBARS in pigs fed the phytase-supplemented, high iron diet was 43%-65% higher than that of other groups although the differences were nonsignificant . Moderately high dietary iron induced hepatic glutathione peroxidase activity (P= 0.06) and protein expression, but decreased catalase (P< 0.05) in the colonic mucosa . In conclusion, intrinsic phytate in corn and soy was protective against lipid peroxidation in the colon associated with a moderately high level of dietary iron.

Int J Syst Bacteriol, 1999 Apr, 49 Pt 2, 887 - 97
Description of Pseudaminobacter gen . nov . with two new species, Pseudaminobacter salicylatoxidans sp . nov . and Pseudaminobacter defluvii sp . nov; Kampfer P et al.; An aerobic bacterium, strain BN12T, which degrades substituted naphthalenesulfonates and substituted salicylates was isolated from a 6-aminonaphthalene-2-sulfonate-degrading microbial consortium originating from the River Elbe, Germany . Chemotaxonomic investigations of quinones, polyamines and polar lipids allowed allocation of this strain to the alpha-subclass of the Proteobacteria and revealed similarity to species of the genera Aminobacter, Chelatobacter and Mesorhizobium . This was confirmed by typing with 16S rRNA-targeted oligonucleotide probes and 16S rDNA sequencing and phylogenetic analysis, indicating that BN12T clusters most closely with a strain 'Thiobacillus' THI 051T and with the above genera but comprising a separate branch . DNA-DNA hybridizations demonstrated that strain BN12T is different from all species of Aminobacter currently described and recognized . The fatty acid patterns, substrate utilization profile and biochemical characteristics displayed no obvious similarity to the characteristics of Aminobacter and Chelatobacter species . 'Thiobacillus' THI 051T, however, revealed phenotypic similarities to BN12T . Furthermore, 16S rRNA sequences of Chelatobacter heintzii showed a high similarity to the 16S rRNA sequences of all currently recognized Aminobacter species . On the basis of these and previously published results, the new genus Pseudaminobacter is proposed, harbouring the two new species Pseudaminobacter salicylatoxidans sp . nov . and Pseudaminobacter defluvii sp . nov . The type strains are BN12T (= DSM 6986T) and THI 051T (= IFO 14570T), respectively.

Phytochemistry, 1999 Apr, 50(7), 1147 - 52
Microbial conversion of jasmonates-hydroxylations by Aspergillus niger; Miersch O et al.; Aspergillus niger is able to hydroxylate the pentenyl side chain of (-)-jasmonic acid (JA) leading to (11S)-(-)-hydroxy-JA/(11R)- (-)-hydroxy-JA (2:1) and (-)-11,12-didehydro-JA . Methyl (-)-jasmonate (JA-Me) is converted upon hydrolysis . During prolonged cultivation or at non-optimized isolation procedures, the 11-hydroxy-(9Z)-pentenyl side chain may isomerize to (10E)-9-hydroxy- and (9E)-11-hydroxy-compounds by allylic rearrangement . The fungus hydroxylates (+/-)-9,10-dihydro-JA at position C-11 into 11 xi-hydroxy-9,10- dihydro-JA . As JA-ME, the methyl dihydro-JA is hydroxylated only upon hydrolysis into the free acid.

Differentiation, 1999 Mar, 64(3), 133 - 41
Differentiation of hemangioblasts from embryonic mesothelial cells? A model on the origin of the vertebrate cardiovascular system; Munoz-Chapuli R et al.; The existence of the hemangioblast, a common progenitor of the endothelial and hematopoietic cell lineages, was proposed at the beginning of the century . Although recent findings seem to confirm its existence, it is still unknown when and how the hemangioblasts differentiate . We propose a hypothesis about the origin of hemangioblasts from the embryonic splanchnic mesothelium . The model is based on observations collected from the literature and from our own studies . These observations include: (1) the extensive population of the splanchnic mesoderm by mesothelial-derived cells coinciding with the emergence of the endothelial and hematopoietic progenitors; (2) the transient localization of cytokeratin, the main mesothelial intermediate filament protein, in some embryonic vessels and endothelial progenitors; (3) the possible origin of cardiac vessels from epicardial-derived cells; (4) the origin of endocardial cells from the splanchnic mesoderm when this mesoderm is an epithelium; (5) the evidence that mesothelial cells migrate to the hemogenic areas of the dorsal aorta . (6) Biochemical and antigenic similarities between mesothelial and endothelial cells . We suggest that the endothelium-lined vascular system arose as a specialization of the phylogenetically older coelomic cavities . The origin of the hematopoietic cells might be related to the differentiation, reported in some invertebrates, of coelomocytes from the coelomic epithelium . Some types of coelomocytes react against microbial invasion and other types transport respiratory pigments . We propose that this phylogenetic origin is recapitulated in the vertebrate ontogeny and explains the differentiation of endothelial and blood cells from a common mesothelial-derived progenitor.

Biochemistry (Mosc), 1999 Apr, 64(4), 365 - 72
Phenol hydroxylases: An update
Solyanikova IP, Golovleva LA.
This paper reviews the enzymology of microbial degradation of chlorinated phenols, a significant group of dangerous environmental pollutants . Two groups of phenol hydroxylases responsible for hydroxylation of (halo)phenols in the ortho or para position have been described . Among ortho-hydroxylating phenol hydroxylases, one-component flavoproteins or multicomponent enzyme systems are recognized, whereas single- or two-component enzyme systems catalyze para-hydroxylation of halophenols.

Immunology, 1999 Apr, 96(4), 511 - 6
Co-immunization with DNA vaccines expressing granulocyte-macrophage colony-stimulating factor and mycobacterial secreted proteins enhances T-cell immunity, but not protective efficacy against Mycobacterium tuberculosis; Kamath AT et al.; The development of more effective antituberculosis vaccines would assist in the control of the global problem of infection with Mycobacterium tuberculosis . One recent vaccination strategy is immunization with DNA plasmids encoding individual microbial genes . Using the genes for the M . tuberculosis-secreted proteins, MPT64 (23 000 MW) and Ag85B (30 000 MW) as candidate antigens, we previously prepared DNA vaccines and demonstrated their ability to stimulate T-cell responses and confer protection in a mouse model of aerosol tuberculosis (TB) . The protective efficacy of the DNA vaccines was less than that promoted by the current vaccine Mycobacterium bovis bacille Calmette-Guerin (BCG) . To improve the immunogenicity and protective efficacy of these mycobacterial vectors, co-immunization of a plasmid expressing granulocyte-macrophage colony-stimulating factor (GM-CSF) was investigated . Intramuscular immunization with DNA expressing MPT64 or Ag85B and GM-CSF enhanced the antigen-specific cellular immune response, with increased proliferative response and production of interferon-gamma (IFN-gamma) . The titre of antimycobacterial protein immunoglobulin G (IgG) antibodies was unchanged . Mice immunized with DNA vaccines showed reduced pulmonary bacterial load following an aerosol challenge of M . tuberculosis, but codelivery of the plasmid expressing GM-CSF did not increase the protective effect . Therefore, despite modifying the cellular immune response to DNA vaccines, GM-CSF does not improve their protective efficacy at the peak of infection after an aerosol challenge with 100 c.f.u . of M . tuberculosis.

Eur J Oral Sci, 1999 Apr, 107(2), 131 - 7
Expression of IL-8 by cells of the odontoblast layer in vitro; Levin LG et al.; Due to their peripheral location in the dental pulp and their cellular extension into dentin, odontoblasts are the first pulpal cells to encounter dental pathogens . The association of odontoblasts with immunoglobulins and dendritic cells during microbial invasion of dentin implies that these cells may possess a role in the innate and adaptive pulpal immune responses, however this has not been examined . A pivotal step in the innate immune response is the detection of foreign antigen and the recruitment of immune effector cells to the area . IL-8 is a potent chemotactic cytokine that plays an important role in the inflammatory response . The purpose of this study was to determine if odontoblasts are capable of expressing the pro-inflammatory chemokine IL-8 . Human odontoblasts from intact, noncarious third molars were maintained in culture and exposed to Escherichia coli lipopolysaccharide (LPS) (serotype 055:B5) on day 4 for 8-10 h in a humidified 5% CO2 incubator . Control and experimental samples were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot for the production of IL-8 mRNA and protein . Analysis of the PCR products revealed that cells of the odontoblast layer maintained in this culture model constitutively expressed low levels of IL-8, which were increased in response to E . coli LPS exposure . Western blotting confirmed that the mRNA was translated into protein . These results imply that odontoblasts are capable of producing of pro-inflammatory mediators, thereby actively participating in the recruitment of neutrophils in response to bacterial by-products.

Immunol Lett, 1999 Apr 1, 67(2), 147 - 52
Molecular mimicry between host and pathogen: examples from parasites and implication; Abu-Shakra M et al.; The studies summarized in this paper suggest that parasites may trigger activation of autoimmune mechanisms . The association between parasites and autoimmunity could by manifested by the development of pathogenic anti-parasitic antibodies and cytotoxic T cells that attack and damage self tissues as a result of molecular mimicry between host and parasites . On the other hand, the homology between self and parasitic antigens may enable parasites to protect themselves from the immune system and to induce a state of immunosuppression . Although classic autoimmune diseases have not been shown to be more common amongst patients with chronic parasitic infections than in the general population, it is clear that autoimmune activity does occur in patients with chronic parasitic infections . It is possible that infection with parasites and other microbial agents may be followed by the activation of the immune system and, in genetically predisposed individuals, by loss of functional tolerance to self, activation of autoreactive cell that leads to progression to an overt autoimmune disease.

Poult Sci, 1999 Apr, 78(4), 550 - 5
Influence of supplemental phytase on performance of broilers four to six weeks of age; Sohail SS et al.; The influence of dietary phytase on phytate P availability was investigated using Ross x Hubbard male broiler chicks . A randomized complete block design with a factorial arrangement of 2 x 3 was used with eight replicates (n = 2,400; 50 chicks per replicate) per treatment . Diets were formulated to contain two levels of nonphytate P (NPP; 0.225 and 0.325%) and three levels of phytase {0, 300, and 600 phytase units (FTU)/kg} with 0.75% Ca . An additional diet with 0.425% NPP and 0.85% Ca was used as a positive control (n = 400) . Prior to assigning treatments, all chicks were fed a commercial starter mash adequate in all nutrients until 3 wk of age . Neither performance nor bone strength was significantly influenced by a reduction of NPP to 0.325% and Ca to 0.75% as compared to the positive control . However, when NPP was reduced to 0.225% and Ca to 0.75%, significant negative impacts on body weight, feed consumption, feed efficiency, and bone strength were observed . Phytase significantly increased BW at the lower NPP level but not at the higher NPP level . A significant NPP by phytase interaction occurred in bone criteria and livability . Phytase (300 FTU/kg) had greater influence on bone mineral content, bone density, bone breaking strength, and livability in broilers fed 0.225% NPP than in broilers fed 0.325% NPP . This study indicates that supplementing phytase in grower diets containing reduced levels of NPP and Ca significantly improved performance and bone strength of broilers . In diets containing marginal to deficient levels of either NPP or Ca or both, the addition of microbial phytase at 300 to 600 FTU/kg feed prevents P deficiency symptoms . Increasing phytase levels from 300 to 600 FTU/kg feed provided no additional benefit.

Environ Health Perspect, 1999 Feb, 107 Suppl 1, 207 - 17
Drinking water disinfection byproducts: review and approach to toxicity evaluation; Boorman GA; There is widespread potential for human exposure to disinfection byproducts (DBPs) in drinking water because everyone drinks, bathes, cooks, and cleans with water . The need for clean and safe water led the U.S . Congress to pass the Safe Drinking Water Act more than 20 years ago in 1974 . In 1976, chloroform, a trihalomethane (THM) and a principal DBP, was shown to be carcinogenic in rodents . This prompted the U.S . Environmental Protection Agency (U.S . EPA) in 1979 to develop a drinking water rule that would provide guidance on the levels of THMs allowed in drinking water . Further concern was raised by epidemiology studies suggesting a weak association between the consumption of chlorinated drinking water and the occurrence of bladder, colon, and rectal cancer . In 1992 the U.S . EPA initiated a negotiated rulemaking to evaluate the need for additional controls for microbial pathogens and DBPs . The goal was to develop an approach that would reduce the level of exposure from disinfectants and DBPs without undermining the control of microbial pathogens . The product of these deliberations was a proposed stage 1 DBP rule . It was agreed that additional information was necessary on how to optimize the use of disinfectants while maintaining control of pathogens before further controls to reduce exposure beyond stage 1 were warranted . In response to this need, the U.S . EPA developed a 5-year research plan to support the development of the longer term rules to control microbial pathogens and DBPs . A considerable body of toxicologic data has been developed on DBPs that occur in the drinking water, but the main emphasis has been on THMs . Given the complexity of the problem and the need for additional data to support the drinking water DBP rules, the U.S . EPA, the National Institute of Environmental Health Sciences, and the U.S . Army are working together to develop a comprehensive biologic and mechanistic DBP database . Selected DBPs will be tested using 2-year toxicity and carcinogenicity studies in standard rodent models; transgenic mouse models and small fish models; in vitro mechanistic and toxicokinetic studies; and reproductive, immunotoxicity, and developmental studies . The goal is to create a toxicity database that reflects a wide range of DBPs resulting from different disinfection practices . This paper describes the approach developed by these agencies to provide the information needed to make scientifically based regulatory decisions.

Environ Health Perspect, 1999 Feb, 107 Suppl 1, 109 - 14
Selected phenolic compounds in cultivated plants: ecologic functions, health implications, and modulation by pesticides; Daniel O et al.; Phenolic compounds are widely distributed in the plant kingdom . Plant tissues may contain up to several grams per kilogram . External stimuli such as microbial infections, ultraviolet radiation, and chemical stressors induce their synthesis . The phenolic compounds resveratrol, flavonoids, and furanocoumarins have many ecologic functions and affect human health . Ecologic functions include defense against microbial pathogens and herbivorous animals . Phenolic compounds may have both beneficial and toxic effects on human health . Effects on low-density lipoproteins and aggregation of platelets are beneficial because they reduce the risk of coronary heart disease . Mutagenic, cancerogenic, and phototoxic effects are risk factors of human health . The synthesis of phenolic compounds in plants can be modulated by the application of herbicides and, to a lesser extent, insecticides and fungicides . The effects on ecosystem functioning and human health are complex and cannot be predicted with great certainty . The consequences of the combined natural and pesticide-induced modulating effects for ecologic functions and human health should be further evaluated.

Infect Dis Obstet Gynecol, 1999, 7(1-2), 58 - 63
Surface-associated heat shock proteins of Legionella pneumophila and Helicobacter pylori: roles in pathogenesis and immunity; Hoffman PS et al.; Bacterial heat shock proteins (Hsps) are abundantly produced during the course of most microbial infections and are often targeted by the mammalian immune response . While Hsps have been well characterized for their roles in protein folding and secretion activities, little attention has been given to their participation in pathogenesis . In the case of Legionella pneumophila, an aquatic intracellular parasite of protozoa and cause of Legionnaires' disease, Hsp60 is uniquely located in the periplasm and on the bacterial surface . Surface-associated Hsp60 promotes attachment and invasion in a HeLa cell model and may alter an early step associated with the fusion of phagosomes with lysosomes . Avirulent strains of L . pneumophila containing defined mutations in several dot/icm genes are defective in localizing Hsp60 onto their surface and are reduced approximately 1000-fold in their invasiveness towards HeLa cells . For the ulcer-causing bacterium Helicobacter pylori, surface-associated Hsp60 and Hsp70 mediate attachment to gastric epithelial cells . The increased expression of these Hsps following acid shock correlates with both increased association with and inflammation of the gastric mucosa . A role for Hsps in colonization, mucosal infection and in promoting inflammation is discussed.

Infect Dis Obstet Gynecol, 1999, 7(1-2), 35 - 8
Immunity to heat shock proteins and pregnancy outcome; Witkin SS; Heat shock proteins are among the first proteins produced by the zygote after fertilization . In addition, the maternal decidua also expresses heat shock proteins during the early stages of pregnancy . Autoimmunity to heat shock proteins is not typically evident in healthy women of reproductive age . However, a chronic microbial infection, such as an asymptomatic Chlamydia trachomatis upper genital tract infection, results in prolonged exposure of the immune system to the microbial 60 kDa heat shock protein (hsp60) . This may result in immunity to conserved hsp60 epitopes and subsequent autoimmunity to self hsp60 . Women undergoing in vitro fertilization (IVF) who never realized they had a chlamydial infection but who were positive for cervical antichlamydial immunoglobulin A (IgA) antibodies had a much lower pregnancy rate than did women who were negative for these antibodies . Furthermore, cervical IgA antibodies to the chlamydial hsp60, as well as to a synthetic peptide corresponding to an hsp60 epitope present in both the chlamydial and human hsp60, also correlated with IVF failure . In vitro incubation of newly fertilized human embryos in medium containing maternal serum was shown to be deleterious to embryo development if the sera was positive for antibodies reactive with human hsp60 . In another study, the ability of human hsp60 to elicit a lymphocyte proliferative response (cell-mediated immunity) correlated with a history of spontaneous early stage pregnancy loss . Thus, autoimmunity to hsp60 might increase susceptibility to early stage pregnancy loss.

Infect Dis Obstet Gynecol, 1999, 7(1-2), 23 - 5
Detection of the human 70-kD and 60-kD heat shock proteins in the vagina: relation to microbial flora, vaginal pH, and method of contraception; Giraldo P et al.; The expression of the 60-kD and 70-kD heat shock proteins (hsp60 and hsp70) in the vaginas of 43 asymptomatic women of reproductive age with or without a history of recurrent vulvovaginitis (RVV) were compared . Vaginal wash samples were obtained and assayed by enzyme-linked immunosorbent assay (ELISA) for human hsp60 and hsp70 . Heat shock protein 70 was not detected in any of the 19 women with no history of RVV, and hsp60 was present in only one woman in this group . In contrast, in the RVV group, 11 (45.8%) were hsp60-positive and eight (33.3%) were hsp70-positive . The presence of either heat shock protein in the vagina was associated with an elevated vaginal pH (>4.5) . Bacterial vaginosis or Candida was identified in some of the asymptomatic subjects; their occurrence was significantly higher in women with vaginal hsp70 than in women with no heat shock proteins . Oral contraceptives were used by 35.7% of subjects who were negative for vaginal heat shock proteins, as opposed to only 12.5% of women who were positive for hsp70 and 8.3% who were positive for hsp60 . Expression of heat shock proteins in the vagina may indicate an altered vaginal environment and a susceptibility to vulvovaginal symptoms.

Infect Dis Obstet Gynecol, 1999, 7(1-2), 10 - 6
Heat shock protein expression during gametogenesis and embryogenesis; Neuer A et al.; When cells are subjected to various stress factors, they increase the production of a group of proteins called heat shock proteins (hsp) . Heat shock proteins are highly conserved proteins present in organisms ranging from bacteria to man . Heat shock proteins enable cells to survive adverse environmental conditions by preventing protein denaturation . Thus the physiological and pathological potential of hsps is enormous and has been studied widely over the past two decades . The presence or absence of hsps influences almost every aspect of reproduction . They are among the first proteins produced during mammalian embryo development . In this report, the production of hsps in gametogenesis and early embryo development is described . It has been suggested that prolonged and asymptomatic infections trigger immunity to microbial hsp epitopes that are also expressed in man . This may be relevant for human reproduction, since many couples with fertility problems have had a previous genital tract infection . Antibodies to bacterial and human hsps are present at high titers in sera of many patients undergoing in vitro fertilization . In a mouse embryo culture model, these antibodies impaired the mouse embryo development at unique developmental stages . The gross morphology of these embryos resembled cells undergoing apoptosis . The TUNEL (terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling) staining pattern, which is a common marker of apoptosis, revealed that embryos cultured in the presence of hsp antibodies stained TUNEL-positive more often than unexposed embryos . These data extend preexisting findings showing the detrimental effect of immune sensitization to hsps on embryo development.

Am J Clin Pathol, 1999 May, 111(5), 647 - 54
Medical and economic benefit of a comprehensive infection control program that includes routine determination of microbial clonality; Hacek DM et al.; Nosocomial infections are a major part of the problem of reemerging pathogens causing infectious diseases, affecting 5% of patients hospitalized in the United States during 1995 . We assessed the medical and economic effects on the overall nosocomial infection rate of an intervention that provided an enhanced, integrated infection control program, including an in-house molecular typing laboratory capability to rapidly assess microbial clonality . Data on nosocomial infections for 24 months prior to the change in approach to infection control were compared with data from the 24 months immediately following implementation of the new program . Infections per 1,000 patient-days and percentage of hospitalized patients in whom nosocomial infection developed were assessed . Overall, nosocomial infections per 1,000 patient-days decreased more than 10% (P = .027), and percentage of patients with nosocomial infection decreased 23% during the post-intervention period compared with the previous control 24 months . This translated to a mean reduction of some 270 patients per year with nosocomial infection, and lowering of actual health care costs for our institution by $4,368,100 over the 2 years of the intervention.

J Anim Sci, 1999 Mar, 77(3), 600 - 10
Behavioral, nutritional, and toxicological responses of cattle to ensiled leafy spurge; Heemstra JM et al.; Yearling cattle (n = 25; 416.1 +/- 25.9 kg) were stratified by weight and gender across five groups . Group 1 (OAT) was offered oat/rape haylage (ORH) for ad libitum consumption during two daily feeding periods . Group 2 (SPURGE) was offered leafy spurge/grass haylage (LSGH) for ad libitum consumption during the same feeding periods . Group 3 was offered ORH in an amount equal to the average amount of LSGH consumed by SPURGE at the previous feeding . Group 4 (MIX) was offered LSGH mixed with ORH for ad libitum consumption during the two feeding periods . Group 5 (PAIR) received the equivalent amount of ORH consumed by MIX at the previous feeding . The DMI for OAT, SPURGE, and MIX were similar at the first feeding (P = .52) . The SPURGE group consumed very little LSGH thereafter and was removed from the trial . The OAT and MIX groups consumed similar amounts of DM daily on d 1 to 4 when the ration offered to MIX was only 7% LSGH (P = .33) . When LSGH made up > or = 21% of the mixture (d 7 to 32), the OAT group consumed more daily DM than did MIX (P < .05) . The spurge/oatlage ration offered to MIX was less digestible than the oatlage-only ration offered to PAIR (P < or = .01) . Even though blood chemistry did not indicate that LSGH consumption caused organ damage, its intake caused minor alterations (P < or = .05) in serum albumin, calcium, gamma glutamyltransferase, P, K, and urea nitrogen . No gross or microscopic lesions, infectious agents, or significant numbers of parasites were detected in any of the carcasses or tissues examined . The MIX group had diarrhea for much of the trial . In Trial 2, five yearling cattle were adapted to a mixture of 21% LSGH and 79% ORH . Then they were simultaneously offered three mixtures of spurge and oat haylages: 1) spurge ensiled with a microbial inoculant (LSGH); 2) spurge ensiled with the same inoculant and a cellulolytic/hemicellulolytic enzyme (ENZ); and 3) spurge ensiled with the same inoculant and molasses (MOL) . The mixture with ENZ was preferred over those with MOL or LSGH (P < .001), but the amounts consumed were low and similar to those for LSGH-ORH in Trial 1 when amounts of ENZ and LSGH in the mixtures were similar . The ENZ mixture may have been more palatable than LSGH and MOL because it had less (P < .05) lactic acid, but intake of ENZ indicates that it had aversive characteristics, like LSGH . Ensiling leafy spurge did little, if anything, to improve its palatability to cattle.

Poult Sci, 1999 May, 78(5), 699 - 706
Influence of microbial phytase on apparent ileal amino acid digestibility of feedstuffs for broilers; Ravindran V et al.; The influence of microbial phytase on the ileal amino acid digestibilities in three cereals (corn, sorghum, and wheat), four oilseed meals (soybean meal, canola meal, cottonseed meal, and sunflower meal) and two cereal by-products (wheat middlings and rice polishings) was determined using 5-wk-old broilers . Supplementation of microbial phytase (1,200 FTU/kg) improved (P < 0.001 to 0.10) the digestibilities of protein and amino acids in all feedstuffs, but the magnitude of response varied depending on the feedstuff and the amino acid considered . Mean digestibility of the 15 amino acids in the feedstuffs without and with phytase were: corn, 78.0 and 80.4%; sorghum, 74.7 and 79.4%; wheat, 77.7 and 84.6%; soybean meal, 82.2 and 85.5%; canola meal, 78.7 and 80.7%; cottonseed meal, 70.8 and 74.2%; sunflower meal, 76.7 and 80.2%; wheat middlings, 70.8 and 73.4%; and rice polishings 62.1 and 66.9%, respectively . When individual amino acids were considered, the increments in digestibility were relatively higher for threonine and valine . This effect was consistent across all feedstuffs . The observed variations in response among feedstuffs were influenced by the inherent protein digestibility, but not by dietary phytic acid concentration . No correlations were determined between the dietary concentrations of phytic acid and phytase responses in terms of protein digestibility (r = 0.20; P > 0.31) and mean amino acid digestibility (r = 0.12; P > 0.51); however a significant negative correlation was observed between inherent protein digestibility and phytase responses in protein digestibility (r = -0.42; P < 0.03) . It appears that solubilities of phytate salts and protein, and their influence on the degree of phytate-protein complexing in different feedstuffs, may be more relevant than total phytic acid concentrations . Interestingly, dietary phytic acid concentrations were negatively correlated with inherent protein (r = -0.81; P < 0.001) and mean amino acid (r = -0.85; P < 0.001) digestibilities of the feedstuffs evaluated in this study.

J Immunol, 1999 May 1, 162(9), 5449 - 54
Augmentation of the CD8+ T cell response by IFN-gamma in IL-12-deficient mice during Toxoplasma gondii infection; Ely KH et al.; The importance of IFN-gamma in regulating the host CD8+ T cell response during microbial infection has not been delineated . Mice deficient for the p40 chain of the IL-12 heterodimer have impaired IFN-gamma production and are susceptible to infection with the intracellular parasite Toxoplasma gondii . The administration of exogenous IFN-gamma to parasite-infected p40-/- mice increases survival and up-regulates the depressed CD8+ T cell response following infection . CD8+ T cells isolated from cytokine-treated p40-/- mice exhibit an increase in both precursor CTL frequency and IFN-gamma production compared with untreated controls . The enhancement of the CD8+ T cell response is independent of CD4+ T cell help . These CD8+ T cells induce protective immunity against a lethal challenge when adoptively transferred into naive p40-/- and IFN-gamma-/- mice . These observations indicate that IFN-gamma can regulate the CD8+ T cell response during T . gondii infection.

J Immunol, 1999 May 1, 162(9), 5380 - 8
In vitro induction of the expression of multiple IgA isotype genes in rabbit B cells by TGF-beta and IL-2; Spieker-Polet H et al.; The rabbit genome has 13 different Calpha genes that are expressed at different levels in mucosal tissues . To analyze the factors involved in the differential expression of these Calpha genes, we cloned and sequenced the promoters of the Ialpha regions that control the expression of sterile mRNA . We found that all Calpha genes, including Calpha3 and Calpha8, which are not expressed, and Calpha4, which is expressed at high levels, have similar nucleotide sequences in the Ialpha region, and all contain the recognition elements for TGF-beta in the promoter . B lymphocytes from popliteal lymph nodes or Peyer's patch activated in vitro could be induced by TGF-beta to express sterile IgA transcripts of all IgA isotypes, except Calpha2, Calpha3, and Calpha8 . Many single B lymphocytes transcribed sterile mRNA of more than one IgA isotype, which demonstrates that transcription of sterile mRNA alone does not regulate the IgA isotype switch . The addition of IL-2 led to the expression of transcripts of mature IgA of all isotypes, except Calpha2, Calpha3, and Calpha8 . The predominantly expressed isotype in these experiments was Calpha4 . With the use of an IgA4-specific mAb we found that IgA4+ plasma cells are unevenly distributed throughout the small intestine such that many of the IgA+ plasma cells in the duodenum-jejunum produced IgA4, whereas in the lower part of the ileum IgA4-producing cells were almost absent . Because the microbial flora varies throughout the intestine, we suggest that the microbial flora creates different local environments and thus affects either isotype switching or homing of IgA-expressing cells.

Microb Ecol, 1999 Apr, 37(3), 197 - 207
Distribution and Composition of Microbial Populations in a Landfill Leachate Contaminated Aquifer (Grindsted, Denmark); Ludvigsen L et al.; > Abstract To investigate whether landfill leachates affected the microbial biomass and/or community composition of the extant microbiota, 37 samples were collected along a 305-m transect of a shallow landfill-leachate polluted aquifer . The samples were analyzed for total numbers of bacteria by use of the acridine orange direct count method (AODC) . Numbers of dominant, specific groups of bacteria and total numbers of protozoa were measured by use of the most probable number method (MPN) . Viable biomass estimates were obtained from measures of ATP and ester-linked phospholipid fatty acid (PLFA) concentrations . The estimated numbers of total bacteria by direct counts were relatively constant throughout the aquifer, ranging from a low of 4.8 x 10(6) cells/g dry weight (dw) to a high of 5.3 x 10(7) cells/g dw . Viable biomass estimates based on PLFA concentrations were one to three orders of magnitude lower with the greatest concentrations (up to 4 x 10(5) cells/g dw) occurring at the border of the landfill and in samples collected from thin lenses of clay and silt with sand streaks . Cell number estimates based on ATP concentrations were also found to be lower than the direct count measurements (<2.2 x 10(6) cells/g dw), and with the greatest concentrations close to the landfill . Methanogens (Archaea) and reducers of sulfate, iron, manganese, and nitrate were all observed in the aquifer . Methanogens were found to be restricted to the most polluted and reduced part of the aquifer at a maximum cell number of 5.4 x 10(4) cells/g dw . Populations of sulfate reducers decreased with an increase in horizontal distance from the landfill ranging from a high of 9.0 x 10(3) cells/g dw to a low of 6 cells/g dw . Iron, manganese, and nitrate reducers were detected throughout the leachate plume all at maximum cell numbers of 10(6) cells/g dw . Changes in PLFA profiles indicated that a shift in microbial community composition occurred with increasing horizontal distance from the landfill . The types and patterns of lipid biomarkers suggested that increased proportions of sulfate- and iron-reducing bacteria as well as certain microeukaryotes existed at the border of the landfill . The presence of these lipid biomarkers correlated with the MPN results . There was, however, no significant correlation between the abundances of the specific PLFA biomarkers and quantitative measurements of redox processes . The application of AODC, MPN, PLFA, and ATP analyses in the characterization of the extant microbiota within the Grindsted aquifer revealed that as distance increased from the leachate source, viable biomass decreased and community composition shifted . These results led to the conclusion that the landfill leachate induced an increase in microbial cell numbers by altering the subsurface aquifer so that it was conducive to the growth of methanogens and of iron-and sulfate-reducing bacteria and fungi.

Food Chem Toxicol, 1999 Feb-Mar, 37(2-3), 233 - 64
A review of the studies of the safety of polydextrose in food; Burdock GA et al.; Polydextrose (CAS no . 68424-04-4) is a water-soluble polymer of glucose that provides to foods the bulk and texture of sucrose . There are two main forms of polydextrose, an acidic form (PD-A) and a neutralized potassium salt (PD-N) . Polydextrose is resistant to mammalian metabolic and microbial degeneration, rendering it both low in caloric value and non-cariogenic . Little polydextrose is absorbed intact although some is metabolized by caecal/colonic bacteria . At high enough levels of ingestion, this bacterial metabolism results in flatus, bloating, loose stools and ultimately a frank diarrhoea . Microbial metabolism also produces some volatile fatty acids that are absorbed by the animal and have calorigenic value . The species and dose threshold for persistent loose stools/watery diarrhoea determines the degree of electrolyte loss by the animal . In the dog, an obligate carnivore, sodium-sparing activity by the kidney and concomitant and obligatory calcium reuptake result in a well-defined aetiology of hypercalcaemia and subsequent nephrocalcinosis, particularly for PD-N . Of the species tested, the dog was the most sensitive to this carbohydrate with a no-effect level of 2000 mg/kg body weight/day . Omnivores, including the rat, mouse and monkey, have a no-effect level ranging from 2500 to 10,000 mg/kg body weight/day . No toxicity has been demonstrated in man, although the dose for laxation (to be distinguished from diarrhoea) is approximately 90 g/day (v . sorbitol at 70 g/day) . Polydextrose did not show any reproductive toxicity, teratology, carcinogenesis, mutagenicity or genotoxicity . Polydextrose has been approved for food additive use (21 CFR 172.841) in the US, and an "ADI not specified" by the Joint WHO/FAO Expert Committee on Food Additives (JECFA, 1987) . It has been approved in over 50 countries around the world and has been used extensively in the diet for over15 years . Specification monographs are published in the Food Chemicals Codex (FCC) (NAS, 1996) and the FAO Compendium (JECFA, 1995) . This review provides an overview of the studies and salient data, not previously reported in the scientific literature, which had been submitted to regulatory agencies in support of these approvals.

Vet Microbiol, 1999 Apr 19, 66(3), 209 - 22
Antibody detection-based differential ELISA for NDV-infected or vaccinated chickens versus NDV HN-subunit vaccinated chickens; Makkay AM et al.; With the advent of subunit vaccines for microbial diseases it is becoming increasingly important to be able to differentiate naturally infected animals from those vaccinated with the corresponding subunit vaccine . For avian viruses such as Newcastle disease virus (NDV), a whole virus-based ELISA cannot make such a differential diagnosis since in both cases the antisera would react with the whole virus . The nucleocapsid protein (NP) gene of the NDV Hitchner B1 strain was cloned, sequenced and expressed to develop a differential ELISA . The B1 NP had 95.7 and 96.1% amino acid identities with the NP of the d26 and Ulster 2C strains, respectively . The B1 NP expressed in a baculovirus expression vector (recNP) was the expected size and reacted with NDV-specific antibodies (Ab) in Western blots and by radioimmunoprecipitation . The ELISA using recNP-coated wells, tested on serum samples from flocks pretested with a commercial NDV kit gave results corresponding to those of the kit . Furthermore, use of both the renNP-based ELISA and a whole virus ELISA allowed the differentiation of birds vaccinated and a NDV haemagglutinin-neuraminidase (HN) expressing fowlpox virus from birds infected with NDV . This provides the basis for establishing an ELISA that discriminates between the antibody response to a recombinant fowlpox vaccine (expressing NDV HN protein) and that to live and inactivated NDV.

Chemotherapy, 1999 May-Jun, 45(3), 213 - 6
Postprostatectomy orchitis: reduction in incidence using perioperative ceftriaxone and postoperative ciprofloxacin; Anyanwu SN; Postoperative orchitis increases the morbidity and overall hospital stay after prostatectomy . A retrospective review of our initial series of 174 cases revealed an incidence of 6% which is similar to other studies . We reviewed our bacterial flora and antibiogram and subsequently started a prospective study combining peri-operative ceftriaxone and postoperative ciprofloxacin, which we compared to our previous series where we used perioperative ceftriaxone followed by postoperative gentamicin and ampicillin . There was an abolition of orchitis as a consequence and a significant reduction in the rate of wound infection . We conclude that a combination of ceftriaxone and ciprofloxacin is efficacious in reducing the rate of infective complications following prostatectomy . We recommend the use of these or similar drugs based on local microbial flora.

Clin Diagn Lab Immunol, 1999 May, 6(3), 345 - 51
Impaired interleukin-8-induced degranulation of polymorphonuclear neutrophils from human immunodeficiency virus type 1-infected individuals; Meddows-Taylor S et al.; Degranulation of peripheral blood polymorphonuclear leukocytes (PMNLs) was monitored in human immunodeficiency virus (HIV) type 1 (HIV-1)-infected individuals with or without pulmonary tuberculosis (HIV/TB and HIV groups, respectively) by measuring the release of beta-glucuronidase induced by interleukin-8 (IL-8) . This was increased in a dose-dependent manner in the control groups consisting of healthy blood donors and patients with pulmonary tuberculosis . In contrast, PMNLs from the HIV and HIV/TB groups responded reciprocally in the same assay; that is, higher IL-8 input concentrations resulted in the release of less enzyme than lower IL-8 input concentrations . The degranulation response of PMNLs from HIV-1-infected individuals was similarly altered for another agonist, N-formyl-methionyl-leucyl-phenylalanine, suggesting that impairment of the nonoxidative armature of PMNL was a more generalized phenomenon . However, impaired IL-8-induced degranulation was found to be associated with the reduced expression of both IL-8 receptors, A and B, on whole-blood PMNLs from HIV-1-infected patients compared with that on whole-blood PMNLs from healthy persons . The density of IL-8RA, in particular, was most reduced on the surfaces of PMNLs from those patients with the poorest degranulation in response to IL-8 . Inefficient agonist-induced degranulation may contribute to the increased susceptibility of HIV-1-infected persons to secondary microbial infections, this being further exacerbated in HIV/TB patients who, in addition, display defects in phagocytosis and oxidative burst.

Blood Rev, 1999 Mar, 13(1), 36 - 44
The classification, recognition and significance of polyagglutination in transfusion medicine; Horn KD; Polyagglutination, although an uncommon phenomenon in transfusion medicine, is becoming increasingly recognized as a potential pitfall in correct ABO typing and can hinder the rapid allocation of accurately crossmatched blood products . Polyagglutination refers to erythrocytes which demonstrate agglutination with the majority of adult sera upon initial ABO crossmatch testing . Most types of polyagglutination involve alteration of red cell surface antigens through microbial enzymatic activity in patients with sepsis, and subsequent interaction of these newly exposed 'cryptantigens' with naturally occuring IgM antibody which is present in most adult sera . Less common variants include essential inborn variations in red cell development, and have been associated with myelodysplastic syndromes, congenital anemias, and various leukemias; it has been suggested that patients shown to possess these types of polyagglutination may benefit from increased hematologic surveillance . Recognition of polyagglutination in these settings is important to allow successful resolution of ABO typing discrepancies and permit efficient administration of appropriate blood products to these patients, who are often quite ill . The classification and method of laboratory recognition of polyagglutination is reviewed.

Vopr Pitan, 1999, 68(2), 32 - 40
{Probiotics, prebiotics and probiotic products . Current status}; Sheveleva SA; This review contains information about eubiotics, probiotics and probiotical products . Such new definitions as prebiotics, synbiotics are described . Review considers characteristics of different kinds of probiotical substances and factors which provide normalization of intestinal microbial balance and related to probiotical action.

Appl Environ Microbiol, 1999 May, 65(5), 2253 - 5
Rapid microbial production of filamentous sulfur mats at hydrothermal vents
Taylor CD, Wirsen CO, Gaill F.
During recent oceanographic cruises to Pacific hydrothermal vent sites (9 degrees N and the Guaymas Basin), the rapid microbial formation of filamentous sulfur mats by a new chemoautotrophic, hydrogen sulfide-oxidizing bacterium was documented in both in situ and shipboard experiments . Observations suggest that formation of these sulfur mats may be a factor in the initial colonization of hydrothermal surfaces by macrofaunal Alvinella worms . This novel metabolic capability, previously shown to be carried out by a coastal strain in H2S continuous-flow reactors, may be an important, heretofore unconsidered, source of microbial organic matter production at deep-sea hydrothermal vents.

Appl Environ Microbiol, 1999 May, 65(5), 2276 - 8
Microbial degradation of octamethylcyclotetrasiloxane; Grumping R et al.; The microbial degradation of low-molecular-weight polydimethylsiloxanes was investigated through laboratory experiments . Octamethylcyclotetrasiloxane was found to be biodegraded under anaerobic conditions in composted sewage sludge, as monitored by the occurrence of the main polydimethylsiloxane degradation product, dimethylsilanediol, compared to that found in experiments with sterilized control samples.

Appl Environ Microbiol, 1999 May, 65(5), 2116 - 21
Role of methanogens and other bacteria in degradation of dimethyl sulfide and methanethiol in anoxic freshwater sediments; Lomans BP et al.; The roles of several trophic groups of organisms (methanogens and sulfate- and nitrate-reducing bacteria) in the microbial degradation of methanethiol (MT) and dimethyl sulfide (DMS) were studied in freshwater sediments . The incubation of DMS- and MT-amended slurries revealed that methanogens are the dominant DMS and MT utilizers in sulfate-poor freshwater systems . In sediment slurries, which were depleted of sulfate, 75 micromol of DMS was stoichiometrically converted into 112 micromol of methane . The addition of methanol or MT to DMS-degrading slurries at concentrations similar to that of DMS reduced DMS degradation rates . This indicates that the methanogens in freshwater sediments, which degrade DMS, are also consumers of methanol and MT . To verify whether a competition between sulfate-reducing and methanogenic bacteria for DMS or MT takes place in sulfate-rich freshwater systems, the effects of sulfate and inhibitors, like bromoethanesulfonic acid, molybdate, and tungstate, on the degradation of MT and DMS were studied . The results for these sulfate-rich and sulfate-amended slurry incubations clearly demonstrated that besides methanogens, sulfate-reducing bacteria take part in MT and DMS degradation in freshwater sediments, provided that sulfate is available . The possible involvement of an interspecies hydrogen transfer in these processes is discussed . In general, our study provides evidence for methanogenesis as a major sink for MT and DMS in freshwater sediments.

Biol Chem, 1999 Mar, 380(3), 375 - 9
DNA-plasmids of HIV-1 induce systemic and mucosal immune responses; Asakura Y et al.; DNA-based immunization has been shown to induce protective immunity against several microbial pathogens including HIV-1 . Several routes of DNA vaccination have been exploited . However, the properties of the immune responses seem to differ with the different routes used for DNA delivery, ultimately affecting the outcome of experimental challenge . We measured the primary immune response following one vaccination . This report presents differences associated with three different DNA delivery routes: intramuscular injection, intranasal application, and gene-gun based immunization . Induction of systemic humoral immune responses was achieved most efficiently by either intranasal or gene-gun mediated immunization, followed by intramuscular injection . Mucosal IgA was reproducibly induced by intranasal instillation of the DNA, and found in lung washings, faeces, and vaginal washings . Cytotoxic T cells were not induced by a single immunization, but were observed after three immunizations using intramuscular injections.

Appl Microbiol Biotechnol, 1999 Mar, 51(3), 293 - 309
Microbial hydantoinases--industrial enzymes from the origin of life?
Syldatk C, May O, Altenbuchner J, Mattes R, Siemann M.
Hydantoinases are valuable enzymes for the production of optically pure D- and L-amino acids . They catalyse the reversible hydrolytic ring cleavage of hydantoin or 5'-monosubstituted hydantoins and are therefore classified in the EC nomenclature as cyclic amidases (EC 3.5.2.) . In the EC nomenclature, four different hydantoin-cleaving enzymes are described: dihydropyrimidinase (3.5.2.2), allantoinase (EC 3.5.2.5), carboxymethylhydantoinase (EC 3.5.2.4), and N-methylhydantoinase (EC 3.5.2.14) . Beside these, other hydantoinases with known metabolic functions, such as imidase and carboxyethylhydantoinase and enzymes with unknown metabolic function, are described in the literature and have not yet been classified . An important question is whether the distinct hydantoinases, which are frequently classified as L-, D-, and non-selective hydantoinases depending on their substrate specificity and stereoselectivity, are related to each other . In order to investigate the evolutionary relationship, amino acid sequence data can be used for a phylogenetic analysis . Although most of these enzymes only share limited sequence homology (identity < 15%) and therefore are only distantly related, it can be shown (i) that most of them are members of a broad set of amidases with similarities to ureases and build a protein superfamily, whereas ATP-dependent hydantoinases are not related, (ii) that the urease-related amidases have evolved divergently from a common ancestor and (iii) that they share a metal-binding motif consisting of conserved histidine residues . The difference in enantioselectivity used for the classification of hydantoinases on the basis of their biotechnological value does not reflect their evolutionary relationship, which is to a more diverse group of enzymes than was assumed earlier . This protein superfamily probably has its origin in the prebiotic conditions of the primitive earth.

Arch Biochem Biophys, 1999 May 1, 365(1), 170 - 4
Isoprenoid biosynthesis via a mevalonate-independent pathway in plants: cloning and heterologous expression of 1-deoxy-D-xylulose-5-phosphate reductoisomerase from peppermint; Lange BM et al.; Two distinct pathways are utilized by plants for the biosynthesis of isopentenyl diphosphate, the universal precursor of isoprenoids . The classical acetate/mevalonate pathway operates in the cytosol, whereas plastidial isoprenoids originate via a novel mevalonate-independent route that involves a transketolase-catalyzed condensation of pyruvate and D-glyceraldehyde-3-phosphate to yield 1-deoxy-D-xylulose-5-phosphate as the first intermediate . Based on in vivo feeding experiments, rearrangement and reduction of deoxyxylulose phosphate have been proposed to give rise to 2-C-methyl-D-erythritol-4-phosphate as the second intermediate of this pyruvate/glyceraldehyde-3-phosphate pathway (1-3) . The cloning of an Escherichia coli gene encoding an enzyme capable of converting 1-deoxy-D-xylulose-5-phosphate to 2-C-erythritol-4-phosphate was recently reported (4) . A cloning strategy was developed for isolating the gene encoding a plant homolog of this enzyme from peppermint (Mentha x piperita), and the identity of the resulting cDNA was confirmed by heterologous expression in E . coli . Unlike the microbial reductoisomerase, the plant ortholog encodes a preprotein bearing an N-terminal plastidial transit peptide that directs the enzyme to plastids where the mevalonate-independent pathway operates in plants . The peppermint gene comprises an open reading frame of 1425 nucleotides which, when the plastidial targeting sequence is excluded, encodes a deduced enzyme of approximately 400 amino acid residues with a mature size of about 43.5 kDa .

Genetica, 1998, 104(2), 85 - 132
The AIDS dilemma: drug diseases blamed on a passenger virus; Duesberg P et al.; Almost two decades of unprecedented efforts in research costing US taxpayers over $50 billion have failed to defeat Acquired Immune Deficiency Syndrome (AIDS) and have failed to explain the chronology and epidemiology of AIDS in America and Europe . The failure to cure AIDS is so complete that the largest American AIDS foundation is even exploiting it for fundraising: 'Latest AIDS statistics-0,000,000 cured . Support a cure, support AMFAR.' The scientific basis of all these unsuccessful efforts has been the hypothesis that AIDS is caused by a sexually transmitted virus, termed Human immunodeficiency virus (HIV), and that this viral immunodeficiency manifests in 30 previously known microbial and non-microbial AIDS diseases . In order to develop a hypothesis that explains AIDS we have considered ten relevant facts that American and European AIDS patients have, and do not have, in common: (1) AIDS is not contagious . For example, not even one health care worker has contracted AIDS from over 800,000 AIDS patients in America and Europe . (2) AIDS is highly non-random with regard to sex (86% male); sexual persuasion (over 60% homosexual); and age (85% are 25-49 years old) . (3) From its beginning in 1980, the AIDS epidemic progressed non-exponentially, just like lifestyle diseases . (4) The epidemic is fragmented into distinct subepidemics with exclusive AIDS-defining diseases . For example, only homosexual males have Kaposi's sarcoma . (5) Patients do not have any one of 30 AIDS-defining diseases, nor even immunodeficiency, in common . For example, Kaposi's sarcoma, dementia, and weight loss may occur without immunodeficiency . Thus, there is no AIDS-specific disease . (6) AIDS patients have antibody against HIV in common only by definition-not by natural coincidence . AIDS-defining diseases of HIV-free patients are called by their old names . (7) Recreational drug use is a common denominator for over 95% of all American and European AIDS patients, including male homosexuals . (8) Lifetime prescriptions of inevitably toxic anti-HIV drugs, such as the DNA chain-terminator AZT, are another common denominator of AIDS patients . (9) HIV proves to be an ideal surrogate marker for recreational and anti-HIV drug use . Since the virus is very rare (< 0.3%) in the US/European population and very hard to transmit sexually, only those who inject street drugs or have over 1,000 typically drug-mediated sexual contacts are likely to become positive . (10) The huge AIDS literature cannot offer even one statistically significant group of drug-free AIDS patients from America and Europe . In view of this, we propose that the long-term consumption of recreational drugs (such as cocaine, heroin, nitrite inhalants, and amphetamines) and prescriptions of DNA chain-terminating and other anti-HIV drugs, cause all AIDS diseases in America and Europe that exceed their long-established, national backgrounds, i.e . > 95% . Chemically distinct drugs cause distinct AIDS-defining diseases; for example, nitrite inhalants cause Kaposi's sarcoma, cocaine causes weight loss, and AZT causes immunodeficiency, lymphoma, muscle atrophy, and dementia . The drug hypothesis predicts that AIDS: (1) is non-contagious; (2) is non-random, because 85% of AIDS causing drugs are used by males, particularly sexually active homosexuals between 25 and 49 years of age, and (3) would follow the drug epidemics chronologically . Indeed, AIDS has increased from negligible numbers in the early 1980s to about 80,000 annual cases in the early '90s and has since declined to about 50,000 cases (US figures) . In the same period, recreational drug users have increased from negligible numbers to millions by the late 1980s, and have since decreased possibly twofold . However, AIDS has declined less because since 1987 increasing numbers of mostly healthy, HIV-positive people, currently about 200,000, use anti-HIV drugs that cause AIDS and other diseases . (ABSTRACT TRUNCATED)

Proc Natl Acad Sci U S A, 1999 Apr 27, 96(9), 5141 - 6
Murine natural killer T(NKT) cells {correction of natural killer cells} contribute to the granulomatous reaction caused by mycobacterial cell walls; Apostolou I et al.; Mice injected with deproteinized cell walls prepared from the strain H37rv of Mycobacterium tuberculosis develop a granuloma-like lesion in which NKT cells are predominant . NKT cells play a primary role in the granulomatous response, because the latter does not occur in Jalpha281(-/-) mice, which miss NKT cells . The glycolipidic fraction of the cell walls is responsible for the recruitment of NKT cells; the recruiting activity is associated with fractions containing phosphatidylinositolmannosides . These results define a powerful experimental set up for studying the in vivo induction of NKT cell responses to microbial components.

Infect Control Hosp Epidemiol, 1999 Apr, 20(4), 237 - 41
Survival of mycobacteria on N95 personal respirators; Reponen TA et al.; OBJECTIVES: The overall aim of this study was to investigate the survival and possible growth of Mycobacterium tuberculosis simulant bacteria on respirator filters . METHODS: Mycobacterium smegmatis was used as a biochemical simulant for M tuberculosis . Bacterial survival was tested on National Institute for Occupational Safety and Health-certified N95 respirators from three manufacturers . The first experiments simulated one-time respirator use and subsequent storage for 1 to 9 days under ideal conditions for the growth of mycobacteria: 37 degrees C and 85% relative humidity . The bacteria were loaded on the respirator filters under three different nutritional conditions: in the absence of nutrients; in the presence of human saliva (simulating conditions when the respirator is worn); and in the presence of nutrient broth (for ideal growth potential) . The subsequent experiments simulated respirator wear for 2 hours under medium work-load conditions at a breathing rate of 56 L/min . RESULTS: It was found that M smegmatis did not grow on the tested respirators, even when the respirators were stored at temperature, humidity, and nutrition conditions most favorable for microbial growth . However, these bacteria could survive on respirators for up to 3 days during storage . The culturability of M smegmatis was not affected by airflow that simulated the breathing rate associated with medium work-load conditions for 2 hours . CONCLUSIONS: This study shows that M tuberculosis surrogate bacteria collected on a respirator are not able to grow and are able to survive only in ideal (ie, not clinically relevant) conditions . Based on these experiments, we conclude that M tuberculosis is unlikely ever to become an infectious problem in the air again, once it is removed by a respirator.

Histochem Cell Biol, 1999 Apr, 111(4), 259 - 64
Expression of tenascin-C and the integrin alpha 9 subunit in regeneration of rat nasal mucosa after chemical injury: involvement in migration and proliferation of epithelial cells; Yoshimura E et al.; Nasal mucosa covered by pseudostratified ciliated epithelia can be injured by microbial infection and physical and chemical agents . To elucidate mechanisms of regeneration, erosion of rat nasal mucosa was produced by intranasal instillation of trichloroacetic acid, and tissue specimens were then sequentially obtained after 1-14 days . Since tenascin-C (TN-C) and its receptor, alpha 9 beta 1 integrin, are assumed to play important roles in regeneration of stratified squamous epithelia, their expression was evaluated by immunohistochemistry and in situ hybridization . Three to five days after the injury, TN-C mRNA was found in epithelial cells of migrating fronts and in epithelial sheets recovering ulcerated surfaces between the fronts and normal regions . TN-C deposition was increased under such sheets . Enhanced alpha 9 staining was also evident in the involved epithelium . 5-Bromo-2'-deoxyuridine incorporation assays revealed significant increase in proliferating cells in cell sheets over TN-C deposits at 3-7 days . Therefore, we conclude that regenerating epithelial cells produce and secrete TN-C, associated with an increase in alpha 9 expression, and that interactions between these molecules could regulate migration and proliferation of the epithelial cells in an autocrine manner.

Clin Immunol, 1999 Apr, 91(1), 77 - 83
The time-dependent clearance of virulent Treponema pallidum in susceptible and resistant strains of guinea pigs is significantly different; Wicher V et al.; The kinetics of clearance of Treponema pallidum spp . pallidum Nichols from skin and testes of susceptible C4-deficient (C4D) and -resistant Albany (Alb) strains of guinea pigs (gps) was evaluated using the polymerase chain reaction (PCR) and the rabbit infectivity test (RIT) . For each strain there were two groups of animals, one infected with virulent T . pallidum (TP) and one control injected with heat-killed treponemes (HKTP) . The kinetic studies and their statistical analysis showed that in the C4D strain the microbial clearance in both tissues was significantly slower (p < 0.005) and still incomplete at 3 months after infection . In the Alb strain the clearance was faster and apparently completed within a month . A greater permissiveness in bacterial growth in C4D compared to Alb appears to be one critical factor determining the different rate of local elimination after primary infection . In both strains there was some correlation between the severity and duration of cutaneous lesions and the local persistence of viable organisms . This correlation was not observed in testes . These studies suggest a genetic basis for the strain-specific susceptibility and resistance phenotypes in the pathogenesis of syphilis.

Rev Environ Contam Toxicol, 1999, 161, 1 - 156
Nitroaromatic munition compounds: environmental effects and screening values; Talmage SS et al.; Available data on the occurrence, transport, transformation, and toxicity of eight nitroaromatic munition compounds and their degradation products, TNT, TNB, DNB, DNA, 2-ADNT, RDX, HMX, and tetryl were used to identify potential fate in the environment and to calculate screening benchmarks or safe environmental levels for aquatic and terrestrial organisms . Results of monitoring studies revealed that some of these compounds persist at sites where they were produced or processed . Most of the compounds are present in soil, sediment, and surface water or groundwater at military sites . Soil adsorption coefficients indicate that these chemicals are only moderately adsorbed to soil and may leach to groundwater . Most of these compounds are transformed by abiotic or biotic mechanisms in environmental media . Primary transformation mechanisms involve photolysis (TNT, RDX, HMX, tetryl), hydrolysis (tetryl), and microbial degradation (TNT, TNB, DNB, DNA, 2-ADNT, and HMX) . Microbial degradation for both nitro and nitramine aromatic compounds involves rapid reduction of nitro groups to amino groups, but further metabolism is slow . With the exception of DNB, complete mineralization did not usually occur under the conditions of the studies . RDX was resistant to microbial degradation . Available ecotoxicological data on acute and chronic studies with freshwater fish and invertebrates were summarized, and water quality criteria or ecotoxicological screening benchmarks were developed . Depending on the available data, criteria/benchmarks were calculated according to USEPA Tier I or Tier II guidelines . The munitions chemicals are moderately to highly toxic to freshwater organisms, with chronic screening values < 1 mg/L . For some chemicals, these low values are caused by inherent toxicity; in other cases, they result from the conservative methods used in the absence of data . For nonionic organic munitions chemicals, sediment quality benchmarks were calculated (based on Kow values and the final chronic value) according to USEPA guidelines . Available data indicate that none of the compounds is expected to bioconcentrate . In the same manner in which reference doses for humans are based on studies with laboratory animals, reference doses or screening benchmarks for wildlife may also be calculated by extrapolation among mammalian species . Chronic NOAELs for the compounds of interest were determined from available laboratory studies . Endpoints selected for wildlife species were those that diminish population growth or survival . Equivalent NOAELs for wildlife were calculated by scaling the test data on the basis of differences in body weight . Data on food and water intake for seven selected wildlife species--short-tailed shrew, white-footed mouse, meadow vole, cottontail rabbit, mink, red fox, and whitetail deer--were used to calculate NOAELs for oral intake . In the case of TNB, a comparison of toxicity data from studies conducted with both the white-footed mouse and the laboratory rat indicates that the white-footed mouse may be more resistant to the toxic effects of chemicals than the laboratory rat and may further indicate the lesser sensitivity of wildlife species to chemical insult . Chronic NOAEL values for the test species based on the laboratory studies indicate that, by the oral route of exposure, TNB and RDX are not highly toxic to mammalian species . However, as seen with TNB, values are less conservative when chronic studies are available or when studies were conducted with wildlife species . Insufficient data were located to calculate NOAELs for avian species . In the absence of criteria or guidelines for terrestrial plants, invertebrates, and soil heterotrophic processes, LOECs were used as screening benchmarks for effect levels in the environment . In most cases, too few data were available to derive a screening benchmark or to have a high degree of confidence in the benchmarks that were derived . (ABSTRACT TRUNCATED)

Biochem J, 1999 May 1, 339 ( Pt 3), 667 - 73
Molecular cloning and expression of adenosine kinase from Leishmania donovani: identification of unconventional P-loop motif; Sinha KM et al.; The unique catalytic characteristics of adenosine kinase (Adk) and its stage-specific differential activity pattern have made this enzyme a prospective target for chemotherapeutic manipulation in the purine-auxotrophic parasitic protozoan Leishmania donovani . However, nothing is known about the structure of the parasite Adk . We report here the cloning of its gene and the characterization of the gene product . The encoded protein, consisting of 345 amino acid residues with a calculated molecular mass of 37173 Da, shares limited but significant similarity with sugar kinases and inosine-guanosine kinase of microbial origin, supporting the notion that these enzymes might have the same ancestral origin . The identity of the parasite enzyme with the corresponding enzyme from two other sources so far described was only 40% . Furthermore, 5' RNA mapping studies indicated that the Adk gene transcript is matured post-transcriptionally with the trans-splicing of the mini-exon (spliced leader) occurring at nt -160 from the predicted translation initiation site . The biochemical properties of the recombinant enzyme were similar to those of the enzyme isolated from leishmanial cells . The intrinsic tryptophan fluorescence of the enzyme was substrate-sensitive . On the basis of a multiple protein-alignment sequence comparison and ATP-induced fluorescence quenching in the presence or the absence of KI and acrylamide, the docking site for ATP has been provisionally identified and shown to have marked divergence from the consensus P-loop motif reported for ATP- or GTP-binding proteins from other sources.

Appl Biochem Biotechnol, 1998 Oct, 75(1), 13 - 24
Mechanism and functional role of antibody catalysis; Paul S; The light (L) chain of a model antibody (Ab) was deduced to contain a serine protease-like catalytic site capable of cleaving peptide bonds . The catalytic site is encoded by a germline VL gene . The catalytic activity can potentially be improved by somatic sequence diversification and pairing of the L chain with the appropriate heavy chain . Autoimmune disease is associated with increased synthesis of antigen (Ag)-specific Abs, but the reasons for this phenomenon are not known . Only recently has attention turned to the functional role of the catalytic function . Preliminary studies confirm that the catalytic cleavage of peptide bonds is a more potent means to achieve Ag neutralization, compared to reversible Ag binding . Administration of a monoclonal Ab to VIP in experimental animals induces an inflammatory response in the airways, suggesting that catalytic autoantibodies to this peptide found in airway disease and lupus are capable of causing airway dysfunction . The phenomenon of autoantibody catalysis can potentially be applied to isolate efficient catalysts directed against tumor or microbial Ags by exposing the autoimmune repertoire to such Ags or their analogs capable of recruiting the germline VL gene encoding the catalytic site.

Acta Vet Hung, 1999, 47(1), 53 - 63
The effect of Saccharomyces cerevisiae1026 used alone or with vitamin-mineral premix on biochemical parameters of blood and milk in dairy cows; Iwanska S et al.; When evaluating the effects of yeast culture (Saccharomyces cerevisiae1026) supplied with or without a vitamin premix and mineral bioplexes on some intermediates and end-products involved in the synthesis of milk constituents in 30 early-lactation Black and White Lowland cows, no significant differences were found in the glucose level, mineral contents and enzyme activities of the blood serum . The effect of yeast culture on the availability of minerals for milk synthesis depended upon the dynamics of degradation of mineral bioplexes in the rumen and the cows' mineral status . The insignificant increase found in blood total protein content and the simultaneous small differences in blood urea nitrogen (BUN) and milk urea nitrogen (MUN) values in cows supplied with the yeast culture were probably associated with a high ammonia incorporation into microbial protein in the rumen, which increased protein supply for milk protein synthesis and decreased the nitrogen loss.

Int Rev Cytol, 1999, 187, 203 - 59
The regulation of apoptosis by microbial pathogens; Moss JE et al.; In the past few years, there has been remarkable progress unraveling the mechanism and significance of eukaryotic programmed cell death (PCD), or apoptosis . Not surprisingly, it has been discovered that numerous, unrelated microbial pathogens engage or circumvent the host's apoptotic program . In this chapter, we briefly summarize apoptosis, emphasizing those studies which assist the reader in understanding the subsequent discussion on PCD and pathogens . We then examine the relationship between virulent bacteria and apoptosis . This section is organized to reflect both common and diverse mechanisms employed by bacteria to induce PCD . A short discussion of parasites and fungi is followed by a detailed description of the interaction of viral pathogens with the apoptotic machinery . Throughout the review, apoptosis is considered within the broader contexts of pathogenesis, virulence, and host defense . Our goals are to update the reader on this rapidly expanding field and identify topics in the current literature which demand further investigation.

J Appl Microbiol, 1999 Apr, 86(4), 673 - 81
Environmental factors affecting the occurrence of mycobacteria in brook sediments; Iivanainen E et al.; The occurrence of mycobacteria was studied in aerobic brook sediments from 39 drainage areas in Finland . The culturable counts of mycobacteria were related to climatic conditions, characteristics of the drainage area, chemical characteristics of the sediment and water, culturable counts of other heterotrophic bacteria, and microbial respiration rate in the sediment . The counts of mycobacteria varied from 1.1 x 10(2) to 1.5 x 10(4) cfu g-1 dry weight of sediment . They correlated positively with the proportion of the drainage area consisting of peatland, total content of C, content of Pb, microbial respiration rate in the sediment, and chemical oxygen demand of the water . The correlations of the mycobacterial counts with pH of sediment and alkalinity of water were negative . The results of the present sediment study and of the forest soil study published earlier strongly suggest that an increase in acidity increases the counts of mycobacteria and decreases the counts and activity of other heterotrophic bacteria . Mycobacterial counts were more than 100 times higher (per dry weight) in forest soils with pH 3.5-4.3 than in sediments with pH 4.5-6.3.

J Vet Pharmacol Ther, 1999 Feb, 22(1), 41 - 51
Pharmacokinetics and milk discard times of pirlimycin after intramammary infusion: a population approach; Whittem T; A population pharmacokinetic approach was used to analyse milk concentration data to determine whether milk discard times and the clearance of intramammary infusions of pirlimycin could be adequately predicted by readily available demographic variables . Milk samples were collected at 12 hourly milking intervals after dosing with pirlimycin during product development from both normal cows (primary data) and cows with naturally occurring mastitis (validation data) and pirlimycin concentration was determined by microbial inhibition assay . The data were analysed by the conditional estimation/ maximum likelihood population approach within the computer program PPharm and fitted a two compartment open model . Bayesian estimates of individual parameters allowed solutions for each cow, predicting the time after last dosing by which milk concentration reached the target safe concentration . From this population of times, the 95% confidence interval of the 99th percentile was defined as the milk discard time . After elimination of one very low producing outlier, the calculated discard time agreed with the label recommendation of 36 h (3 milkings, USA) after the last dose . Milk pirlimycin clearance was strongly and positively correlated to the logarithm of the kilograms of milk produced in 24 h at time of dosing (r2=0.939) . Agreement was strong at most time points between predicted and measured pirlimycin concentrations in milk from cows with mastitis . This alternative method for determining milk discard times was compared to existing recommendations.

Curr Opin Biotechnol, 1999 Apr, 10(2), 130 - 6
Combinatorial biocatalysis: taking the lead from nature; Altreuter DH et al.; Combinatorial biocatalysis is an emerging technology in the field of drug discovery . The biocatalytic approach to combinatorial chemistry uses enzymatic, chemoenzymatic, and microbial transformations to generate libraries from lead compounds . Important recent advances in combinatorial biocatalysis include iterative derivatization of small molecules and complex natural products, regioselectively controlled libraries, novel one-pot library syntheses, process automation, and biocatalyst enhancements.

Int J Colorectal Dis, 1999 Feb, 14(1), 13 - 7
Inflammatory bowel disease and the genes for the natural resistance-associated macrophage protein-1 and the interferon-gamma receptor 1; Stokkers PC et al.; The genes for the interferon-gamma receptor 1 and the natural resistance-associated macrophage protein 1 (NRAMP1) control the immune response to intracellular microbial pathogens . Such pathogens, in particular Mycobacterium paratuberculosis, have been implicated in the pathogenesis of Crohn's disease . We studied markers in the genes for NRAMP1 and two mutations in the interferon-gamma receptor in relation to inflammatory bowel disease (IBD) in the following groups: 270 healthy individuals, 74 patients with Crohn's disease, 72 patients with ulcerative colitis, and 40 patients with primary sclerosing cholangitis . We studied the allele frequencies of two restriction fragment length polymorphisms in the gene for NRAMP1 and the prevalence of two mutations in the interferon-gamma receptor 1 gene . The markers in the NRAMP1 gene were not associated with inflammatory bowel disease . Also, the mutations in the interferon-gamma receptor 1 were not found in the 186 IBD patients . Genetic markers in NRAMP1 are thus not associated with IBD . Therefore this gene is not likely to play a role in the pathogenesis of IBD . The mutation in the interferon-gamma receptor was not found in our IBD patients group.

Plant J, 1999 Feb, 17(4), 329 - 39
Molecular cloning and functional expression of O-methyltransferases common to isoquinoline alkaloid and phenylpropanoid biosynthesis; Frick S et al.; In cell suspension cultures of the meadow rue Thalictrum tuberosum, biosynthesis of the anti-microbial alkaloid berberine can be induced by addition of methyl jasmonate to the culture medium . The activities of the four methyltransferases involved in the formation of berberine from L-tyrosine are increased in response to elicitor addition . Partial clones generated by RT-PCR with methyltransferase-specific primers were used as hybridization probes to isolate four cDNAs encoding O-methyltransferases from a cDNA library prepared from poly(A)+ RNA isolated from methyl jasmonate-induced cell suspension cultures of T . tuberosum . RNA gel blot hybridization indicated that the transcripts for the methyltransferases accumulated in response to addition of methyl jasmonate to the cell culture medium . The cDNAs were functionally expressed in Spodoptera frugiperda Sf9 cells and were shown to have varying and broad substrate specificities . A difference of a single amino acid residue between two of the enzymes was sufficient to alter the substrate specificity . The four cDNAs were expressed either as four homodimers or as six heterodimers by co-infection with all possible combinations of the four recombinant baculoviruses . These 10 isoforms thus produced displayed distinct substrate specificities and in some cases co-infection with two different recombinant baculoviruses led to the O-methylation of new substrates . The substrates that were O-methylated varied in structural complexity from simple catechols to phenylpropanoids, tetrahydrobenzylisoquinoline, protoberberine and tetrahydrophenethylisoquinoline alkaloids, suggesting that some biosynthetic enzymes may be common to both phenylpropanoid and alkaloid anabolism.

J Leukoc Biol, 1999 Apr, 65(4), 444 - 52
The cellular immunology of multiple sclerosis; Al-Omaishi J et al.; Multiple sclerosis (MS) is a neurological disease that affects the central nervous system (brain and spinal cord) resulting in debilitating motor and sensory dysfunction . Its mean age of onset is 30 years and, with the exception of trauma, MS remains the most frequent cause of neurological disabilities for young adults . The disease is highly variable in its onset and progression . It may not be easily diagnosed, at least in its earliest stages . Significant disability is a hallmark of MS . Indeed, up to 50% of patients require walking aids and 10% are wheelchair-bound at 15 years after an initial diagnosis . Clinical features include deficits in sensory (parasthesias and numbness), motor (difficulties with fine movements and gait), balance, bladder, and sexual functions . Although the etiology for MS is not yet known, it is thought to be related to microbial, genetic, and/or environmental factors . Pathologically, MS is characterized by inflammation . An influx of mononuclear cells occurs through a disrupted blood-brain barrier into an immune-privileged central nervous system . The secretion of a variety of inflammatory cytokines and chemokines from glial cells leads to loss of myelin, disruption of oligodendrocyte integrity, and axonal loss . These events, in large measure, affect progressive neural atrophy . How brain inflammatory activities affect transendothelial migration of leukocytes into the brain and alter the process of myelination are the focal points for MS research activities.

J Hosp Infect, 1999 Mar, 41(3), 195 - 201
Comparative efficiency of nitrocellulose membranes versus RODAC plates in microbial sampling on surfaces; Poletti L et al.; The efficiency of nitrocelluose membranes in collecting microbial samples from rigid and flat surfaces has been studied and compared with that of RODAC plates . The experimental design was based on multiple samplings in close succession in the same place . The median efficiency of membrane filters (78.55) was higher than that of RODAC plates (65.37) . The data demonstrate the reliability of membranes and show that membranes are more efficient than RODAC plates as a sampling method for measuring surface microbial contamination.

Vestn Ross Akad Med Nauk, 1999, (2), 10 - 5
{Active oxygen metabolites in provision and control of natural cytotoxic reactions}; Cheknev SB; Whether the redox active compounds that are able to generate and capture free oxygen radicals utilized in natural cytotoxicity (NCT) are involved in the provision and control of NCT in the body of man and animals is discussed . Evidence is given for the participation of endogenous metal-binding peptido(proteo)glycans (MBPPG) in the establishment and maintenance of regulatory balance in the complex of NCT reactions . Cyanobacterial exometabolites and their related metal-binding amphipathic compounds yielded in the exosystem was substantiated to be involved in the rational limitation of lymphocytic cytotoxicity . The findings suggest that exogenous redox active microbial products exert their action on NCT cells by changing the rate of generation and capture of free oxygen radicals by exogenous MBPPG.

AIDS, 1999 Feb 4, 13(2), 177 - 84
Immunopathology as a result of highly active antiretroviral therapy in HIV-1-infected patients; Foudraine NA et al.; OBJECTIVE: Unusual clinical inflammatory syndromes associated with underlying previously unrecognized opportunistic infections are increasingly being noted shortly after starting highly active antiretroviral therapy (HAART) . This study examined the possible relationship between such unexpected disease manifestations and in vitro parameters of microbial antigen-specific immune reactivity in patients infected with HIV-1 who had a Mycobacterium avium intracellulare or Mycobacterium xenopi infection . DESIGN: In vitro T-cell proliferation experiments were performed after specific stimulation of a patient's peripheral blood mononuclear cells (PBMC) with M . avium and M . xenopi antigen and non-specific stimulation with phytohaemagglutinin (PHA) . The results were compared with appropriate controls . PATIENTS: Five patients who presented with unusual clinical syndromes associated with M . avium or M . xenopi infection within weeks of experiencing large rises in CD4+ cell counts following the initiation of antiretroviral therapy . RESULTS: In all patients except one, mycobacteria-specific lymphoproliferative responses rose significantly following HAART; this was temporally associated with elevations in CD4+ cell counts and the occurrence of clinical disease . The patient with M . xenopi infection appeared to clear his infection subsequently without antimycobacterial therapy . In three of the four patients with M . avium infection, antimycobacterial treatment could be stopped without recurrence of infection . CONCLUSION: Our findings support the hypothesis that HAART may lead to clinically relevant inflammation as a result of restoration of specific immune reactivity against microbial pathogens that are subclinically present at the time treatment is initiated . Continuation of HAART may subsequently result in protective immunity and clearance of infection.

J Immunol, 1999 Apr 15, 162(8), 4910 - 3
Inflammation alone evokes the response of a TCR-invariant mouse gamma delta T cell subset; Mukasa A et al.; Whether gamma delta T lymphocytes respond to microbial Ags or to inducible host Ags remains a matter of controversy . Using several different disease models and mouse strains, we and others have seen that V gamma 6/V delta 1 gamma delta T cells preferentially increase among the gamma delta T cells infiltrating inflamed tissues . However, it was not clear whether bacteria are necessary to bring about this response . Therefore, we have reexamined this question using a disease model in which inflammation is induced by a purely autoimmune process involving no bacteria, bacterial products, or other foreign material: testicular cell-induced autoimmune orchitis . Using this model we found that gamma delta T cells were still plentiful among the infiltrating T lymphocytes, being 9- to 10-fold more prevalent than in spleen, and that V gamma 6/V delta 1+ cells again represented the predominant gamma delta T cell type . This finding shows that the response of the V gamma 6/V delta 1+ subset does not, in fact, depend upon the presence of bacteria or bacterial products . The stimulus triggering the response of the V gamma 6/V delta 1 gamma delta T cells appears to be neither foreign nor organ-specific in origin, but instead consists of a self-derived host Ag or signal induced during the inflammatory process.

J Am Vet Med Assoc, 1999 Apr 1, 214(7), 1048 - 50
Specificity of assays used by regulatory agencies to detect antibiotic residues in tissues of culled dairy cows; Payne MA et al.; OBJECTIVE: To determine percentage of false-positive test results for assays used by regulatory agencies to detect antibiotic residues in tissues . DESIGN: Prospective study . ANIMALS: 426 dairy cows . PROCEDURE: Dairy cows scheduled for culling that were identified as being unlikely to have antibiotic residues in tissues on the basis of strict inclusion criteria were used . A sample of kidney obtained from each cow at slaughter was tested on-site, using the swab test on premises (STOP; 97 samples) or the fast antibiotic screening test (FAST; 329 samples) . Frozen samples (n = 1,278) of liver, muscle, and kidney were thawed and retested at a federal laboratory, using the same screening assays . Kidney and liver samples (n = 852) were also tested using the 7-plate bioassay confirmation test used for confirmation and identification of antibiotic residues . RESULTS: Results of screening assays performed onsite were negative . When frozen samples were retested, 20 (12 liver, 7 kidney, and 1 muscle) had positive FAST results, but none had positive STOP results . Of the samples tested with the 7-plate bioassay confirmation test, 4 liver samples had results indicating a tetracycline (n = 3) or an unidentified microbial inhibitor (1) as a residue . CLINICAL IMPLICATIONS: Results suggest it is unlikely that regulatory action will be taken against producers sending untreated cattle to market . However, because results of the FAST and 7-plate bioassay confirmation test were positive when applied to frozen tissue, use of assays based on microbial inhibition may not be valid for confirmation of residues.

AIDS, 1999 Feb 25, 13(3), 375 - 80
Bone marrow macrophage iron grade and survival of HIV-seropositive patients; de Monye C et al.; OBJECTIVE: Increased iron stores predispose to certain microbial infections . This association might be especially important in patients whose immune system is impaired by HIV . This study examined the relationship between iron stores and the survival times of patients with HIV infection . DESIGN: Retrospective analysis of iron stores, as determined directly in bone marrow aspirates, and of hospital records . SETTING: The George Washington University Hospital, an urban academic tertiary care institution . PATIENTS: Three hundred and forty-eight HIV-seropositive adults who had diagnostic bone marrow aspirates between January 1985 and June 1996 . MEASUREMENTS: Bone marrow macrophage iron stores were graded on a scale of 0 to 5 . For analysis of the influence of iron stores on survival, we compared patients with grades 4-5 iron stores (markedly or massively increased; n = 188) to those with grades 0-2 iron stores (normal or decreased; n = 130) . RESULTS: Infections caused by Candida spp., Pneumocystis carinii, and Mycobacterium spp . were more common in patients with high macrophage iron grades than in patients with low or normal iron grades (P < or = 0.006) . The adjusted estimated rate of death (hazards ratio) was higher in patients with high iron stores compared with patients with low or normal iron stores, both from the time of the bone marrow study (ratio of 2.1; 95% confidence interval 1.3-3.5; P = 0.003) and the determination of HIV-seropositivity (ratio of 2.8; 95% confidence interval 1.4-4.9; P = 0.001) . CONCLUSION: High iron stores, as determined by bone marrow macrophage iron grade, may be associated with shorter survival times in patients with HIV infection.

J Nutr Sci Vitaminol (Tokyo), 1998 Dec, 44(6), 841 - 51
Class specific influence of dietary Spirulina platensis on antibody production in mice; Hayashi O et al.; In the present study, we investigated antibody productions of IgA and other classes, such as IgE and IgG1, in mice as possible evidence of the protective effects of Spirulina toward food allergy and microbial infection . An increase of IgE antibody level in the serum was observed in the mice that were orally immunized with crude shrimp extract as an antigen (Ag group) . The antibody level, however, was not further enhanced by treatment with Spirulina extract (SpHW) . IgG1 antibody, on the other hand, which was increased by antigen administration, was further enhanced by Spirulina extract . It was noted that the IgA antibody level in the intestinal contents was significantly enhanced by treatment with Spirulina extract concurrently ingested with shrimp antigen, in comparison with that of the Ag group treated with shrimp antigen alone . An enhancement of IgA antibody production by Spirulina extract was also observed in culture supernatant of lymphoid cells, especially in the spleen and mesenteric lymph node from mice treated with Spirulina extract for 4 weeks before antigen stimulation . These results suggest that Spirulina may at least neither induce nor enhance allergic reaction such as food allergy dependent on an IgE antibody, and that when ingested both concurrently with antigen and before antigen stimulation, it may significantly enhance the IgA antibody level to protect against allergic reaction.

Implant Dent, 1998, 7(4), 331 - 7
Tissue compatibility to different surfaces of dental implants: in vitro studies; Keller JC; Factors affecting cell and tissue responses to dental implant biomaterials are typically characterized as spatial and temporal . Spatially, a dental implant must form an interface with both bone tissue for the development and maintenance of biomechanical stability and soft tissue for the prevention of microbial infection that can lead to peri-implantitis . There is a developing body of knowledge regarding the reactions of host tissues to implant materials, although the specific mechanisms by which these responses are not yet totally understood . From a temporal standpoint, there seems to be a sequence of events after placement of an implant that involves cell attachment, migration, and differentiation . These early wound healing responses appear to be influenced significantly by the properties of the underlying implant surface . Our laboratory has focused its attention on the first cellular event, i.e., cell attachment at the interface between bone and the implant surface . An in vitro primary cell model has been developed and used to study the influence of materials selection (Ti, Ti-6Al-4V, hydroxyapatite-like coatings), surface topography (smooth to rough), and surface chemistry (as a function of preparation treatments) on the cellular events that occur at implant surfaces . Currently, we believe that both uncoated Ti implants and those fabricated with calcium phosphate or hydroxyapatite-like coatings are capable of supporting initial cellular attachment, although they probably occur by different and incompletely understood mechanisms . The initial interactions of the host tissues with the implant surface remain key for long-term acceptance and must be understood if new generations of tissue engineered devices are to be developed and used clinically.

Biotechnol Prog, 1999 Mar, 15(2), 147 - 57
Application of enzymes in the pulp and paper industry
Bajpai P.
The pulp and paper industry processes huge quantities of lignocellulosic biomass every year . The technology for pulp manufacture is highly diverse, and numerous opportunities exist for the application of microbial enzymes . Historically, enzymes have found some uses in the paper industry, but these have been mainly confined to areas such as modifications of raw starch . However, a wide range of applications in the pulp and paper industry have now been identified . The use of enzymes in the pulp and paper industry has grown rapidly since the mid 1980s . While many applications of enzymes in the pulp and paper industry are still in the research and development stage, several applications have found their way into the mills in an unprecedented short period of time . Currently the most important application of enzymes is in the prebleaching of kraft pulp . Xylanase enzymes have been found to be most effective for that purpose . Xylanase prebleaching technology is now in use at several mills worldwide . This technology has been successfully transferred to full industrial scale in just a few years . The enzymatic pitch control method using lipase was put into practice in a large-scale paper-making process as a routine operation in the early 1990s and was the first case in the world in which an enzyme was successfully applied in the actual paper-making process . Improvement of pulp drainage with enzymes is practiced routinely at mill scale . Enzymatic deinking has also been successfully applied during mill trials and can be expected to expand in application as increasing amounts of newsprint must be deinked and recycled . The University of Georgia has recently opened a pilot plant for deinking of recycled paper . Pulp bleaching with a laccase mediator system has reached pilot plant stage and is expected to be commercialized soon . Enzymatic debarking, enzymatic beating, and reduction of vessel picking with enzymes are still in the R&D stage but hold great promise for reducing energy . Other enzymatic applications, i.e., removal of shives and slime, retting of flax fibers, and selective removal of xylan, are also expected to have a profound impact on the future technology of the pulp and paper-making process.

Vaccine, 1999 Mar 26, 17(13-14), 1612 - 9
DNA immunization: mechanistic studies; Whitton JL et al.; DNA immunization works, as has been amply demonstrated in a variety of microbial and tumor models . However, the mechanisms which underpin its success remain unclear . Using intramuscular delivery of DNA, we wish to precisely define how DNA-encoded antigens induce CD8+ T-cells (most cytotoxic T-cells; CTL), CD4+ T-cells (mostly helper cells) and antibodies; and to use the accrued knowledge to rationally manipulate DNA vaccines, thus enabling us to optimize each of the above three types of immune response . We consider it likely that different mechanisms operate in each case . We have designed a DNA vaccine which induces CTL, but not antibodies . We will present evidence that CTL are induced by endogenously-synthesized protein, not by protein released from cells; and that in the absence of release of intact protein, antibodies are not induced, while CTL induction remains strong . We have used plasmid-encoded minigenes and have found that these short sequences also induce CTL; this, too, argues that CTL are induced by antigens presented following endogenous synthesis . We are attempting to determine how antigens are released from transfected cells, to interact with B-cells and induce antibodies, and are currently evaluating the CD4 responses induced by DNA vaccines.

Am J Orthod Dentofacial Orthop, 1999 Apr, 115(4), 423 - 8
Site-specific subgingival colonization by Actinobacillus actinomycetemcomitans in orthodontic patients; Paolantonio M et al.; A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed . The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances . Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study . After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa . Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth . Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus . Altogether, 192 periodontal sites were examined . After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites) . Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks . At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed . The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively . Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study . It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth . The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth.

Hematol Cell Ther, 1999 Feb, 41(1), 1 - 3
Leukocyte recovery from umbilical cord blood by poligeline; Perutelli P et al.; Umbilical cord blood (UCB) collected at delivery is a source of transplantable stem/progenitor cells; it represents an alternative to bone marrow to restore hematopoiesis in patients affected by malignant and non-malignant disease . Therefore, large-scale UCB banks would be a natural complement to bone marrow donor registries . Storage of unmanipulated whole UCB units requires a great number of liquid nitrogen containers . Separation of leukocytes allows UCB storage in smaller space, thus lowering banking costs; unfortunately, UCB processing may cause significant losses of stem cells . We report about the use of poligeline to remove erythrocytes from UCB units . After erythrocyte sedimentation at 1xg (30' or 40') or 50xg, leukocyte-rich supernatant was collected and centrifuged to recover the leukocyte pool in view of stem cell transplantation . Erythrocyte depletion was always satisfactory, ranging from 82.6% to 88.9%, but 1xg sedimentation for 40' enabled us to achieve the best CD34+ cell recovery (mean value 80.5%) . The proposed UCB-processing method allowed us to lower the final sample volume down to 1/10 of the initial one, in this way making UCB banking feasible . Erythrocyte depletion took place directly in the collection bag, thus reducing microbial contamination risk.

Clin Exp Immunol, 1999 Mar, 115(3), 435 - 42
The modulating effects of proinflammatory cytokines interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and immunoregulating cytokines IL-10 and transforming growth factor-beta (TGF-beta), on anti-microbial activity of murine peritoneal macrophages against Mycobacterium avium-intracellulare complex; Sano C et al.; We assessed the roles of proinflammatory cytokines IFN-gamma and TNF-alpha, and immunoregulatory cytokines IL-10 and TGF-beta in the modulation of the anti-microbial activity of murine peritoneal macrophages against Mycobacterium avium-intracellulare complex (MAIC) . First, both IFN-gamma and TNF-alpha significantly reduced the bacterial growth in macrophages, indicating that these cytokines participate in up-regulation of macrophage anti-MAIC function . Second, although MAIC-infected macrophages produced substantial amounts of IL-10 and TGF-beta, neutralization of endogenous IL-10 and TGF-beta with anti-IL-10 and anti-TGF-beta antibodies, respectively, did not affect the intracellular growth of MAIC in macrophages from mice with BcgS (MAIC-susceptible) or BcgI (MAIC-resistant) genotype, regardless of the virulence of test MAIC strains . The same result was also obtained for macrophages stimulated with IFN-gamma or TNF-alpha . Third, in MAIC-infected mice, the growth of organisms at the sites of infection (lungs and spleens) was not affected by administration of anti-IL-10 or anti-TGF-beta antibodies . These findings indicate that, in the case of mice, endogenous IL-10 and TGF-beta are essentially ineffective in down-regulating macrophage anti-MAIC functions not only in vitro but also in vivo.

Thorax, 1998 Nov, 53(11), 927 - 32
Early childhood infection and atopic disorder; Farooqi IS et al.; BACKGROUND: Atopy is of complex origins but the recent rise in atopic diseases in westernized communities points to the action of important environmental effects . One candidate mechanism is the changing pattern of microbial exposure in childhood . This epidemiological study investigated the relationship between childhood infections and subsequent atopic disease, taking into account a range of social and medical variables . METHODS: A total of 1934 subjects representing a retrospective 1975-84 birth group at a family doctor practice in Oxfordshire were studied . Public health and practice records were reviewed; temporal records were made of all diagnoses of infections and their treatments, all immunisations, and diagnoses of asthma, hay fever and eczema; maternal atopy and a number of other variables were documented . RESULTS: Logistic regression analysis identified three statistically significant predictors of subsequent atopic disease: maternal atopy (1.97, 95% CI 1.46 to 2.66, p < 0.0001), immunisation with whole-cell pertussis vaccine (1.76, 95% CI 1.39 to 2.23, p < 0.0001), and treatment with oral antibiotics in the first two years of life (2.07, 95% CI 1.64 to 2.60, p < 0.0001) . There was no significant association found for maternal smoking, bottle feeding, sibship size, or social class . CONCLUSIONS: The prediction of atopic disease by maternal atopy mainly reflects the effect of acknowledged genetic factors . Interpretation of the prediction of atopic disorders by immunisation with wholecell pertussis vaccine and treatment with oral antibiotics needs to be very cautious because of the possibilities of confounding effects and reverse causation . However, plausible immune mechanisms are identifiable for the promotion of atopic disorders by both factors and further investigation of these association is warranted.

J Dent, 1999 May, 27(4), 313 - 6
Effect of sterilisation methods on the structural integrity of artificial enamel caries for intra-oral cariogenicity tests; Amaecha BT et al.; Enamel blocks bearing artificial caries are used in intra-oral appliances for cariogenicity tests . These blocks are often sterilised to prevent the possibility of cross-infection via this route . This study therefore aimed to determine the effect of sterilisation methods on the structural integrity of artificial enamel caries used for intra-oral cariogenicity tests . Four experimental groups were devised . Ten bovine incisors were used in each group . Artificial caries was produced in each tooth which was subsequently cut into two halves . One half of each tooth was reserved as control while the other was sterilised . The four groups were subjected to respective sterilisation methods: gamma irradiation (approximately equal to 25 KGy), steam autoclaving (121 degrees C for 15 min), sodium hypochlorite (12% w/v for 24 h) and povidone-iodine (7.5% w/v for 24 h) . The control and sterilised specimens in each group were examined for microbial growth after incubation in nutrient broth for up to 7 days at 37 degrees C under aerobic and anaerobic conditions . Mineral loss and lesion depth were quantified from microradiographs of sections from control and sterilised specimens using transverse microradiography . Data were analysed statistically by paired Student's t-test . Microbial growth was observed only in control specimens . Gamma irradiation and NaOCL caused cream discolouration and bleaching of the enamel surface, respectively . Autoclaving, sodium hypochlorite and povidone-iodine resulted in further demineralisation of the lesions . The four sterilisation methods were all effective sterilants for artificial caries . However, gamma irradiation appears the most acceptable method considering the more adverse effects of the other methods with regards to cariogenicity tests.

J Microbiol Methods, 1999 Mar, 35(2), 157 - 61
Estimating microbial population counts by 'most probable number' using Microsoft Excel; Briones AM Jr et al.; A computer-assisted method for determining population counts using the 'most probable number' (MPN) was developed . The Microsoft Excel spreadsheet and its Solver tool were used to generate MPNs, error estimates and confidence limits . Our method was flexible, allowing the use of unbalanced replication schemes and varying replication numbers and inoculation volumes . Furthermore, it required no programming skills and generated fast results, which were comparable to those of standard MPN tables and MPN software.

Cell Biochem Funct, 1999 Mar, 17(1), 35 - 45
Effect of Aspergillus terreus mycotoxins on nitric oxide synthase activity in human erythroid K-562 cells; Pugliese A et al.; Because several stimuli of microbial origin enhance the activity of nitric oxide synthase (NOS) in human cells of the myeloid lineage, we decided to investigate whether cellular damage induced by Aspergillus terreus mycotoxins could be associated with an increase in NOS activity . A pool of mycotoxins rather than individual toxins was tested so that the natural conditions could be mimicked . In the present study, we report that a crude extract of A . terreus induces cellular damage and increases NOS activity in K-562 cells, an erythroleukaemic cell line in which NOS is particularly active . The specificity of this association was further investigated by using NOS inhibitors and by comparing, in the same cellular model, the effects of the extract with the activity of other microbial toxins of a defined mechanism of action . Canavanine, an inhibitor of NOS, significantly reduced cell death in the presence of the extract, suggesting that cellular damage, induced by the mycotoxins of A . terreus is at least in part mediated by NOS activity . Moreover, Escherichia coli lipopolysaccharide (LPS), known to be a potent NOS inducer, increased NOS activity in our experimental model as well . In contrast, Bordetella pertussis toxin did not show any effect on NOS activity . The results of this study suggest that NOS may be involved in mycotoxicoses.

Biotechnol Bioeng, 1998 Apr 20-May 5, 58(2-3), 162 - 9
How will bioinformatics influence metabolic engineering?
Edwards JS, Palsson BO.
Ten microbial genomes have been fully sequenced to date, and the sequencing of many more genomes is expected to be completed before the end of the century . The assignment of function to open reading frames (ORFs) is progressing, and for some genomes over 70% of functional assignments have been made . The majority of the assigned ORFs relate to metabolic functions . Thus, the complete genetic and biochemical functions of a number of microbial cells may be soon available . From a metabolic engineering standpoint, these developments open a new realm of possibilities . Metabolic analysis and engineering strategies can now be built on a sound genomic basis . An important question that now arises; how should these tasks be approached? Flux-balance analysis (FBA) has the potential to play an important role . It is based on the fundamental principle of mass conservation . It requires only the stoichiometric matrix, the metabolic demands, and some strain specific parameters . Importantly, no enzymatic kinetic data is required . In this article, we show how the genomically defined microbial metabolic genotypes can be analyzed by FBA . Fundamental concepts of metabolic genotype, metabolic phenotype, metabolic redundancy and robustness are defined and examples of their use given . We discuss the advantage of this approach, and how FBA is expected to find uses in the near future . FBA is likely to become an important analysis tool for genomically based approaches to metabolic engineering, strain design, and development .

Biotechnol Bioeng, 1998 Apr 20-May 5, 58(2-3), 154 - 61
Application of mathematical tools for metabolic design of microbial ethanol production; Hatzimanikatis V et al.; Many attempts to engineer cellular metabolism have failed due to the complexity of cellular functions . Mathematical and computational methods are needed that can organize the available experimental information, and provide insight and guidance for successful metabolic engineering . Two such methods are reviewed here . Both methods employ a (log)linear kinetic model of metabolism that is constructed based on enzyme kinetics characteristics . The first method allows the description of the dynamic responses of metabolic systems subject to spatiotemporal variations in their parameters . The second method considers the product-oriented, constrained optimization of metabolic reaction networks using mixed-integer linear programming methods . The optimization framework is used in order to identify the combinations of the metabolic characteristics of the glycolytic enzymes from yeast and bacteria that will maximize ethanol production . The methods are also applied to the design of microbial ethanol production metabolism . The results of the calculations are in qualitative agreement with experimental data presented here . Experiments and calculations suggest that, in resting Escherichia coli cells, ethanol production and glucose uptake rates can be increased by 30% and 20%, respectively, by overexpression of a deregulated pyruvate kinase, while increase in phosphofructokinase expression levels has no effect on ethanol production and glucose uptake rates .

Am J Health Syst Pharm, 1999 Mar 15, 56(6), 547 - 50
Stability of fumagillin in an extemporaneously prepared ophthalmic solution; Abdel-Rahman SM et al.; The stability of fumagillin 70 microg/mL (as the bicyclohexylammonium crystal) in an extemporaneously prepared ophthalmic solution was studied . An ophthalmic solution of fumagillin 70 microg/mL was prepared by combining 120 mg of fumagillin bicyclohexylammonium crystals with 20 mL of 0.9% Sodium Chloride Injection, USP, and 20 mL of an ophthalmic irrigating solution . The solution was stored in 12 sterile semi-opaque dropper bottles; 4 bottles were stored at 25 degrees C exposed to light, 4 were stored at 25 degrees C in the dark, and 4 were stored at 4 degrees C in the dark . Samples were taken on days 0, 7, 14, 21, and 28 and analyzed by high-performance liquid chromatography . Sterility was tested as well . In the solutions stored at 25 degrees C, 17-30% of the initial drug concentration was lost during the first week . The solution protected from light and stored at 4 degrees C lost about 12% of active drug by week 4 . There was no change in color or odor in any of the solutions and only a minor change in pH over the study period . There was no evidence of microbial growth in any of the solutions tested . Fumagillin 70 microg/mL (as the bicyclohexylammonium crystal) in 0.9% sodium chloride injection and an ophthalmic irrigating solution containing benzalkonium chloride was stable in the dark for 14 days at 4 degrees C.

Vet Microbiol, 1999 Mar 12, 65(3), 241 - 54
Influence of age and plasma treatment on neutrophil phagocytosis and CD18 expression in foals; Grondahl G et al.; The aim of this study was to evaluate the influence of age and plasma treatment on neutrophil phagocytosis, CD18 expression and serum opsonic capacity in foals in field settings . Microbial infections constitute a large threat in young foals and neutrophil functions are crucial for the defense . Blood samples were obtained from 13 foals at seven time points between the ages of 2 and 56 days and once from 16 adult horses . Six of the foals were treated with adult plasma at the age of 1 week . Neutrophil phagocytosis of yeast after various opsonizations and the expression of complement adhesion receptor CD18 were analysed by flow cytometry . Autologous serum opsonization resulted in 52+/-6.1% phagocytic neutrophils in 2-day-old foals (n = 12), a significantly lower rate than in adult horses (mean 84+/-3.1%; n = 16) . In foals, yeast ingestion per neutrophil was also lower than in adults . Opsonic capacity increased with age (p < 0.05), reaching adult levels at 3-4 weeks . An increase in serum opsonic capacity followed plasma treatment (p < 0.05) . The phagocytic capacity of foal neutrophils at the time-points studied was equal to or higher than that in the adults, when pooled adult horse serum or anti-yeast IgG was used as opsonin . In foals, serum IgG concentration was negatively correlated to serum opsonic capacity . CD18 receptor expression was higher in neutrophils from foals (<21 days old) than in those from adult horses (p < 0.05) . The results indicate that foals are transiently deficient in serum opsonic capacity, which negatively affects their capacity for neutrophil phagocytosis . These changes in serum opsonins, unrelated to IgG, may be important factors in susceptibility to infections in foals.

Appl Environ Microbiol, 1999 Apr, 65(4), 1619 - 26
Biphasic extracellular proteolytic enzyme activity in benthic water and sediment in the northwestern mediterranean Sea
Tholosan O, Lamy F, Garcin J, Polychronaki T, Bianchi A.
In this study, we used the fact that bacteria are able to cleave a fluorogenic substrate analog (L-leucine-7-amido-4-methylcoumarin) to determine the maximal ectoproteolytic activities (Vm) and affinities (Km) of natural benthic microbial communities by the multiconcentration kinetic method . This investigation was performed during the winter and summer of 1997 with a set of 36 samples of near-bottom water and sediment collected from a coastal area and an offshore area in the western part of the Gulf of Lions . The existence of biphasic microbial ectoproteolysis was statistically confirmed for both the near-bottom water and the sediment, regardless of the spatial and seasonal conditions . Globally, 72.2% of the entire set of bacterial consortia collected at the water-sediment boundary layer showed biphasic microbial kinetics . A specific estimator of the biphasicity indicated that deep benthic bacterial consortia responded better with episodic nutrient supplies than shallower benthic bacterial consortia responded.

Appl Environ Microbiol, 1999 Apr, 65(4), 1662 - 9
Levels of bacterial community diversity in four arid soils compared by cultivation and 16S rRNA gene cloning; Dunbar J et al.; Techniques based on amplification of 16S rRNA genes for comparing bacterial communities are now widely used in microbial ecology, but calibration of these techniques with traditional tools, such as cultivation, has been conspicuously absent . In this study, we compared levels of bacterial community diversity in two pinyon rhizosphere soil samples and two between-tree (interspace) soil samples by analyzing 179 cultivated bacterial isolates and 801 16S rRNA genes amplified from extracted soil DNA . Phylotypes were defined by performing a restriction fragment length polymorphism analysis of 16S rRNA gene sequences with the enzymes RsaI and BstUI . The average level of 16S rRNA gene sequence similarity of members of a phylotype was 86.6% based on an analysis of partial sequences . A total of 498 phylotypes were identified among the 16S ribosomal DNA (rDNA) clones, while 34 phylotypes occurred among the cultivated isolates . Analysis of sequences from a subset of the phylotypes showed that at least seven bacterial divisions were represented in the clone libraries, whereas the isolates represented only three . The phylotype richness, frequency distribution (evenness), and composition of the four culture collections and the four clone libraries were investigated by using a variety of diversity indices . Although cultivation and 16S rRNA cloning analyses gave contradictory descriptions of the relative phylotype richness for one of the four environments, the two methods identified qualitatively consistent relationships when levels of evenness were compared . The levels of phylotype similarity between communities were uniformly low (15 to 31%) . Both methods consistently indicated that one environment was distinct from the other three . Our data illustrate that while 16S rDNA cloning and cultivation generally describe similar relationships between soil microbial communities, significant discrepancies can occur.

Appl Environ Microbiol, 1999 Apr, 65(4), 1627 - 35
Selection of clc, cba, and fcb chlorobenzoate-catabolic genotypes from groundwater and surface waters adjacent to the Hyde park, Niagara Falls, chemical landfill; Peel MC et al.; The frequency of isolation of three nonhomologous chlorobenzoate catabolic genotypes (clc, cba, and fcb) was determined for 464 isolates from freshwater sediments and groundwater in the vicinity of the Hyde Park industrial landfill site in the Niagara watershed . Samples were collected from both contaminated and noncontaminated sites during spring, summer, and fall and enriched at 4, 22, or 32 degrees C with micromolar to millimolar concentrations of chlorobenzoates and 3-chlorobiphenyl (M . C . Peel and R . C . Wyndham, Microb . Ecol: 33:59-68, 1997) . Hybridization at moderate stringency to restriction-digested genomic DNA with DNA probes revealed the chlorocatechol 1,2-dioxygenase operon (clcABD), the 3-chlorobenzoate 3,4-(4,5)-dioxygenase operon (cbaABC), and the 4-chlorobenzoate dehalogenase (fcbB) gene in isolates enriched from all contaminated sites in the vicinity of the industrial landfill . Nevertheless, the known genes were found in less than 10% of the isolates from the contaminated sites, indicating a high level of genetic diversity in the microbial community . The known genotypes were not enriched from the noncontaminated control sites nearby . The clc, cba, and fcb isolates were distributed across five phenotypically distinct groups based on Biolog carbon source utilization, with the breadth of the host range decreasing in the order clc > cba > fcb . Restriction fragment length polymorphism (RFLP) patterns showed that the cba genes were conserved in all isolates whereas the clc and fcb genes exhibited variation in RFLP patterns . These observations are consistent with the recent spread of the cba genes by horizontal transfer as part of transposon Tn5271 in response to contaminant exposure at Hyde Park . Consistent with this hypothesis, IS1071, the flanking element in Tn5271, was found in all isolates that carried the cba genes . Interestingly, IS1071 was also found in a high proportion of isolates from Hyde Park carrying the clc and fcb genes, as well as in type strains carrying the clcABD operon and the biphenyl (bph) catabolic genes.

Appl Environ Microbiol, 1999 Apr, 65(4), 1372 - 7
Formation of hydride-Meisenheimer complexes of picric acid (2,4, 6-trinitrophenol) and 2,4-dinitrophenol during mineralization of picric acid by Nocardioides sp . strain CB 22-2; Behrend C et al.; There are only a few examples of microbial conversion of picric acid (2,4,6-trinitrophenol) . None of the organisms that have been described previously is able to use this compound as a sole source of carbon, nitrogen, and energy at high rates . In this study we isolated and characterized a strain, strain CB 22-2, that was able to use picric acid as a sole source of carbon and energy at concentrations up to 40 mM and at rates of 1.6 mmol . h(-1) . g (dry weight) of cells(-1) in continuous cultures and 920 micromol . h(-1) . g (dry weight) of cells(-1) in flasks . In addition, this strain was able to use picric acid as a sole source of nitrogen at comparable rates in a nitrogen-free medium . Biochemical characterization and 16S ribosomal DNA analysis revealed that strain CB 22-2 is a Nocardioides sp . strain . High-pressure liquid chromatography and UV-visible light data, the low residual chemical oxygen demand, and the stoichiometric release of 2.9 +/- 0.1 mol of nitrite per mol of picric acid provided strong evidence that complete mineralization of picric acid occurred . During transformation, the metabolites detected in the culture supernatant were the {H-}-Meisenheimer complexes of picric acid and 2,4-dinitrophenol (H--DNP), as well as 2,4-dinitrophenol . Experiments performed with crude extracts revealed that H--DNP formation indeed is a physiologically relevant step in picric acid metabolism.

Immunopharmacology, 1999 Feb, 41(2), 89 - 107
PGG-glucan, a soluble beta-(1,3)-glucan, enhances the oxidative burst response, microbicidal activity, and activates an NF-kappa B-like factor in human PMN: evidence for a glycosphingolipid beta-(1,3)-glucan receptor; Wakshull E et al.; PGG-Glucan, a soluble beta-(1,6)-branched beta-(1,3)-linked glucose homopolymer derived from the cell wall of the yeast Saccharomyces cerevisiae, is an immunomodulator which enhances leukocyte anti-infective activity and enhances myeloid and megakaryocyte progenitor proliferation . Incubation of human whole blood with PGG-Glucan significantly enhanced the oxidative burst response of subsequently isolated blood leukocytes to both soluble and particulate activators in a dose-dependent manner, and increased leukocyte microbicidal activity . No evidence for inflammatory cytokine production was obtained under these conditions . Electrophoretic mobility shift assays demonstrated that PGG-Glucan induced the activation of an NF-kappaB-like nuclear transcription factor in purified human neutrophils . The binding of 3H-PGG-Glucan to human leukocyte membranes was specific, concentration-dependent, saturable, and high affinity (Kd approximately 6 nM) . A monoclonal antibody specific to the glycosphingolipid lactosylceramide was able to inhibit activation of the NF-kappaB-like factor by PGG-Glucan, and ligand binding data, including polysaccharide specificity, suggested that the PGG-Glucan binding moiety was lactosylceramide . These results indicate that PGG-Glucan enhances neutrophil anti-microbial functions and that interaction between this beta-glucan and human neutrophils is mediated by the glycosphingolipid lactosylceramide present at the cell surface.

Chemosphere, 1999 Apr, 38(10), 2415 - 30
Ratio of the concentration of anthraquinone to anthracene in coastal marine sediments; McKinney RA et al.; The ratio of the concentration of the oxidation product anthraquinone to that of its parent polycyclic aromatic hydrocarbon anthracene is reported for several coastal marine sediments . The ratio ranges from 0.317 in a highly contaminated industrialized harbor to 2.81 in a remote, less contaminated site . We hypothesize that differences in this ratio result from the input source of PAHs, with input from atmospheric deposition at remote sites resulting in a predominance of anthraquinone (ratio > 1), and direct discharge to highly contaminated industrialized harbors resulting in a predominance of anthracene (ratio < 1) . To support this hypothesis, the fate of anthracene in the marine environment was investigated with respect to conversion to its oxidation product, anthraquinone . Once associated with sediments, anthracene is believed to be relatively persistent; however, it can potentially be subjected to oxidation via biological (microbial degradation) and chemical (chemical oxidation and photooxidation) processes . An assessment of the extent of oxidation of anthracene associated with sediments was conducted both under conditions simulating those found in the marine environment and under rigorous conditions by exposure to UV radiation . Results of this study show that while anthracene associated with marine sediments does not readily undergo oxidation to anthraquinone under conditions normally encountered in the marine environment, under extreme conditions anthracene is photooxidized by exposure to UV radiation . The extent of oxidation is influenced by sediment characteristics such as percent organic carbon, humic acid content and sediment surface area . The relative stability of anthracene under normal conditions may help to validate the use of the anthraquinone to anthracene ratio in marine sediments as an environmental marker of contaminant source.

Biosens Bioelectron, 1999 Feb, 14(2), 131 - 8
Measurement of biodegradable substances using the salt-tolerant yeast Arxula adeninivorans for a microbial sensor immobilized with poly(carbamoyl) sulfonate (PCS) Part I: Construction and characterization of the microbial sensor; Chan C et al.; A microbial biosensor based on the yeast Arxula adeninivorans LS3 has been developed for measurement of biodegradable substances . Arxula is immobilized in the hydrogel poly(carbamoyl) sulfonate (PCS) . The immobilized yeast membrane is placed in front of an oxygen electrode with -600 mV versus Ag/AgCl . Arxula is salt tolerant; it can give a stable signal up to 2.5 M NaCl in sample (120 mM in measuring cell) . The sensor's measurements are highly correlated to BOD5 measurements . It has a very high stability which can last for 40 day without any decrease in signal . The linear range of the sensor is up to a corresponding BOD value of 550 mg/l.

Biotechnol Bioeng, 1999 Jan 20, 62(2), 242 - 5
A simple method to determine the water activity of ethanol-containing samples
Hallsworth JE, Nomura Y.
The water activity (aw) of microbial substrates, biological samples, and foods and drinks is usually determined by direct measurement of the equilibrium relative humidity above a sample . However, these materials can contain ethanol, which disrupts the operation of humidity sensors . Previously, an indirect and problematic technique based on freezing-point depression measurements was needed to calculate the aw when ethanol was present . We now describe a rapid and accurate method to determine the aw of ethanol-containing samples at ambient temperatures . Disruption of sensor measurements was minimized by using a newly developed, alcohol-resistant humidity sensor fitted with an alcohol filter . Linear equations were derived from aw measurements of standard ethanol-water mixtures, and from Norrish's equation, to correct sensor measurements . To our knowledge, this is the first time that electronic sensors have been used to determine the aw of ethanol-containing samples .

Biotechnol Bioeng, 1999 Jan 20, 62(2), 200 - 7
Inhibitory effects and biotransformation of acrylic acid in computer-controlled pH-stat CSTRs; Demirer GN et al.; In this study, the inhibitory effects and anaerobic biotransformation of acrylic acid in computer-controlled pH-stat completely stirred tank reactors (CSTRs) with two different cultures, namely unacclimated and acrylate-acclimated acetate-enriched Methanosarcina and homogenized (crushed) granular cultures, were investigated . The microbial acclimation, influent concentration, and loading rate of acrylic acid were studied in the experiments . The experimental results revealed that methanogenic cultures at a concentration of 3200 +/- 80 mg/L as volatile suspended solids (VSS) could be acclimated to acrylic acid up to a loading rate of 220 mg/L per day (0.068 g acrylic acid/g VSS per day) in the presence of a constant acetate concentration of 2000 +/- 200 mg/L as the primary substrate after 300 days of acclimation . The same cultures (680 +/- 80 mg/L as VSS), after 80 days of acclimation to acrylic acid as the sole carbon source, transformed acrylic acid up to the loading rate of about 200 mg/L per day (0.29 g acrylic acid/g VSS per day) almost completely (>99%) to acetic and propionic acid, but could not effectively metabolize these intermediate products . Acrylate-acclimated homogenized granular cultures (6900 +/- 80 mg/L as VSS) effectively metabolized 2200 mg/L per day (0.32 g acrylic acid/g VSS per day) of acrylic acid, as the sole carbon source, after 50 days of severe inhibition .

Biotechnol Bioeng, 1999 Jan 20, 62(2), 160 - 5
Reductive dechlorination of chlorinated ethene DNAPLs by a culture enriched from contaminated groundwater; Nielsen RB et al.; A microbial culture enriched from a trichloroethene-contaminated groundwater aquifer reductively dechlorinated trichloroethene (TCE) and tetrachloroethene (PCE) to ethene . Initial PCE dechlorination rate studies indicated a first-order dependence with respect to substrate at low PCE concentrations, and a zero-order dependence at high concentrations . Studies of TCE and vinyl chloride (VC) dechlorination indicated a first-order dependence at all substrate concentrations . VC had little or no effect on the initial rate of TCE dechlorination . With subsaturating concentrations of chlorinated ethenes, nearly stoichiometric amounts of the toxic intermediate vinyl chloride accumulated prior to its dechlorination to ethene . In contrast, under saturating conditions, in which a dense, nonaqueous-phase liquid existed in equilibrium with the aqueous phase, the chlorinated ethene was dechlorinated to ethene, at a rapid rate, with the accumulation of relatively small amounts of chlorinated intermediates .

Biotechnol Bioeng, 1998 Sep 20, 59(6), 732 - 46
A unified model describing the role of hydrogen in the growth of desulfovibrio vulgaris under different environmental conditions
Noguera DR, Brusseau GA, Rittmann BE, Stahl DA.
A unified model for the growth of Desulfovibrio vulgaris under different environmental conditions is presented . The model assumes the existence of two electron transport mechanisms functioning simultaneously . One mechanism results in the evolution and consumption of hydrogen, as in the hydrogen-cycling model . The second mechanism assumes a direct transport of electrons from the donor to the acceptor, without the participation of H2 . A combination of kinetic and thermodynamic conditions control the flow of electrons through each pathway . The model was calibrated using batch experiments with D . vulgaris grown on lactate, in the presence and absence of sulfate, and was verified using additional batch experiments under different conditions . The model captured the general trends of consumption of substrates and accumulation of products, including the transient accumulation and consumption of H2 . Furthermore, the model estimated that 48% of the electrons transported from lactate to sulfate involved H2 production, indicating that hydrogen cycling is a fundamental process in D . vulgaris . The presence of simultaneous electron transport mechanisms might provide D . vulgaris with important ecological advantages, because it facilitates a rapid response to changes in environmental conditions . This model increases our ability to study the microbial ecology of anaerobic environments and the role of Desulfovibrio species in a variety of environments .

Biotechnol Bioeng, 1998 Jul 5, 59(1), 116 - 21
The dynamical analogy between microbial growth on mixtures of substrates and population growth of competing species; Narang A; There is a similarity between the metabolic dynamics of a microbial species growing on a mixture of two substrates and the dynamics of growth of two competing populations . Specifically, the enzymes catalyzing the uptake and catabolism of substrates exhibit phenomena analogous to extinction and coexistence."Extinction" of the enzymes associated with one of the substrates results in sequential utilization of the substrates (diauxie) (Monod, 1942) . "Coexistence" of the enzymes associated with the substrates results in simultaneous utilization of the substrates (Egli, 1995) . Here, we formulate a simple model that shows the basis for this dynamical similarity: The equations describing the evolution of the enzyme levels are dynamical analogs of the Lotka-Volterra model for two competing species . The analogy suggests ways of capturing the experimentally observed preculture-dependent growth patterns, i.e., growth patterns that vary depending on the physiological state of the preculture .

Biotechnol Bioeng, 1998 Jun 20, 58(6), 617 - 24
Biooxidation capacity of the extremely thermoacidophilic archaeon metallosphaera sedula under bioenergetic challenge
Han CJ, Kelly RM.
The biooxidation capacity of an extremely thermoacidophilic archaeon Metallosphaera sedula (DSMZ 5348) was examined under bioenergetic challenges imparted by thermal or chemical stress in regard to its potential use in microbial bioleaching processes . Within the normal growth temperature range of M . sedula (70-79 degrees C) at pH 2.0, upward temperature shifts resulted in bioleaching rates that followed an Arrhenius-like dependence . When the cells were subjected to supraoptimal temperatures through gradual thermal acclimation at 81 degrees C (Han et al., 1997), cell densities were reduced but 3 to 5 times faster specific leaching rates (Fe3+ released from iron pyrite/cell/h) could be achieved by the stressed cells compared to cells at 79 degrees C and 73 degrees C, respectively . The respiration capacity of M . sedula growing at 74 degrees C was challenged by poisoning the cells with uncouplers to generate chemical stress . When the protonophore 2,4-dinitrophenol (5-10 muM) was added to a growing culture of M . sedula on iron pyrite, there was little effect on specific leaching rates compared to a culture with no protonophore at 74 degrees C; 25 muM levels proved to be toxic to M . sedula . However, a significant stimulation in specific rate was observed when the cells were subjected to 1 muM nigericin (+135%) and 2 muM (+63%); 5 muM levels of the ionophore completely arrested cell growth . The ionophore effect was further investigated in continuous culture growing on ferrous sulfate at 74 degrees C . When 1 muM nigericin was added as a pulse to a continuous culture, a 30% increase in specific iron oxidation rate was observed for short intervals, indicating a potential positive impact on leaching when periodic chemical stress is applied . This study suggests that biooxidation rates can be increased by strategic exposure of extreme thermoacidophiles to chemical or thermal stress, and this approach should be considered for improving process performance .

J Anim Sci, 1999 Feb, 77(2), 467 - 75
Supplemental cracked corn for steers fed fresh alfalfa: II . Protein and amino acid digestion; Elizalde JC et al.; The effects of different levels of cracked corn on N intake, ruminal bacterial CP synthesis, and duodenal flows and small intestinal digestion of amino acids (AA) in steers fed fresh alfalfa indoors were determined . Angus steers (n = 6; average BW 338 +/- 19 kg) cannulated in the rumen, duodenum, and ileum were fed each of five diets over five periods in a Latin square design with an extra animal . Steers consumed 1) alfalfa (20.4% CP, 41.6% NDF) ad libitum (AALF); 2), 3), and 4) AALF supplemented (S) with three levels of corn (.4, .8, or 1.2% of BW, respectively), or 5) alfalfa restricted (RALF) to the average forage intake of S steers . Average N intake and duodenal flow of nonammonia N (NAN) were greater (P < .01) in S than in RALF steers . Greater duodenal flows of NAN in S compared with RALF were due to a trend toward higher (P = .06) flows of both bacterial and dietary N . Levels of corn decreased (P < .01) linearly N intake and increased (P < .01) linearly duodenal flow of NAN owing to a numerical linear increase in nonbacterial N (P = .15) with no increase in bacterial N flow . Duodenal NAN flows as percentages of N intake increased (P < .01) linearly (69.3 to 91.0%) as corn increased . Ruminal NH3 N concentration, ruminal CP degradability, and the proportion of bacterial N in duodenal NAN were decreased (P < .01) linearly as corn increased . Efficiency of net microbial CP synthesis was not affected (P > .05) by treatment (average 42.6 and 30.9 g N/kg of OM apparently or truly digested in the rumen, respectively) . Small intestinal disappearance of total N and individual AA, except for threonine and lysine, and small intestinal digestibility of N and individual AA, except for methionine, histidine, and proline, increased (P < .01) linearly with level of corn and were greater (P < .01) in S than in RALF steers . Supplementing corn to steers fed fresh alfalfa reduced ruminal N losses and CP degradability and increased the duodenal flow and the small intestinal disappearance and digestibility of total N and total, essential, and nonessential AA.

Pharm Res, 1999 Feb, 16(2), 281 - 7
Enantioselective synthesis and pharmacological evaluation of a new type of verapamil analog with hypotensive and calcium antagonist activities; Holland HL et al.; PURPOSE: The syntheses and evaluation for cardiovascular activity in the rat of both enantiomers of a verapamil analog in which the cyano group has been replaced by hydroxyl . METHODS: (+)- and (-)-alpha-{3-{{2-(3,4-Dimethoxyphenyl)ethyl}methylamino}propyl}- 3,4-dimethoxy-alpha-(1-methyl ethyl)benzyl alcohol were prepared from chiral sulfoxides produced by microbial biotransformations using Mortierella isabellina ATCC 42613 or Helminthsporium species NRRL 4671, and were examined for hypotensive and calcium antagonist activity using anaesthetized normotensive rats and isolated rat aorta and atria . RESULTS: The analogs showed a pharmacological profile similar to that exhibited by verapamil, possessing a remarkable hypotensive activity, accompanied by a significant bradycardia, in anaesthetized normotensive rats . In vitro, these analogs displayed clear inhibitory effects: in isolated rat aorta they inhibited, in a concentration-dependent fashion, the contractions and 45Ca2+ uptake induced by norepinephrine and high KCl, and in isolated rat atria the analogs considerably decreased the rate of contraction (negative chronotropic effects) . No significant differences between the quantitative cardiovascular effects produced by the two enantiomers of the verapamil analogs were observed . CONCLUSIONS: The results suggest that, like that of verapamil, the cardiovascular activity exhibited by the new compounds seems to be due, at least in part, to a blockage of transmembrane calcium channels present in vascular smooth muscle cells.

Microsc Res Tech, 1999 Feb 15, 44(4), 237 - 53
Cell adhesion and the immune system: a case study using earthworms; Cooper EL et al.; In the earthworm's immune system, cell adhesion, which occurs by putative receptors on leukocytes, is essential after recognition of self vs . non-self . Confrontation with foreign antigens is a normal event in the environment, replete with microbial pathogens that pose a threat to survival . To better understand what happens when an effector cell first recognizes a foreign target followed by its adhesion to it, isolated leukocytes, in sufficient quantities to be subjected to various analyses, have been extremely beneficial . In vitro approaches when accompanied by biochemical, immunological, and molecular technologies, have opened up new vistas concerning the immune response of earthworms and other invertebrates . The most recent discovery includes the preliminary identification of cell differentiation (CD) markers that play vital roles in recognitive and adhesive events . Certain leukocyte effectors show characteristics of natural killer (NK) cells that may act differently depending upon their source, whether autogeneic, allogeneic, xenogeneic, or expressed under normal or varying environmental conditions including exposure to xenobiotics . At the level of earthworm evolution, there is apparently a dissociation of phagocytosis from the process of killing by NK-like effectors . There are at least three future challenges . First, it is essential to determine the precise nature of the CD markers with respect to their molecular structure . Second, once their molecular and biochemical characteristics have been defined, the role of these markers in cellular and humoral mechanisms must be clarified in order to define effector cell products and resulting immune responses . Third, there is a need to differentiate between the several lytic factors that have been found in earthworms with respect to molecular structure, and biochemical and functional characterization.

Proc Natl Acad Sci U S A, 1999 Mar 30, 96(7), 4023 - 7
Evolution of microbial diversity during prolonged starvation; Finkel SE et al.; Models of evolutionary processes postulate that new alleles appear in populations through random spontaneous mutation . Alleles that confer a competitive advantage in particular environments are selected and populations can be taken over by individuals expressing these advantageous mutations . We have studied the evolutionary process by using Escherichia coli cultures incubated for prolonged periods of time in stationary phase . The populations of surviving cells were shown to be highly dynamic, even after many months of incubation . Evolution proceeded along different paths even when the initial conditions were identical . As cultures aged, the takeovers by fitter mutants were incomplete, resulting in the coexistence of multiple mutant forms and increased microbial diversity . Thus, the study of bacterial populations in stationary phase provides a model system for understanding the evolution of diversity in natural populations.

Mol Microbiol, 1998 Nov, 30(4), 711 - 23
Decorin-binding adhesins from Borrelia burgdorferi; Guo BP et al.; Lyme disease is a tick-transmitted infection caused by the spirochete Borrelia burgdorferi . Ticks deposit B . burgdorferi into the dermis of the host, where they eventually become associated with collagen fibres . We demonstrated previously that B . burgdorferi is unable to bind collagen, but can bind the collagen-associated proteoglycan decorin and expresses decorin-binding proteins (Dbps) . We have now cloned and sequenced two genes encoding the proteins, DbpA and DbpB, which have a similar structure, as revealed by circular dichroism (CD) spectroscopy of recombinant proteins . Competition experiments revealed a difference in binding specificity between DbpA and DbpB . Western blot analysis of proteinase K-treated intact B . burgdorferi and transmission electron microscopy studies using antibodies raised against recombinant Dbps demonstrated that these proteins are surface exposed . DbpA effectively inhibits the attachment of B . burgdorferi to a decorin substrate, whereas DbpB had a marginal effect, suggesting a difference in substrate specificity between the two Dbps . Polystyrene beads coated with DbpA adhered to a decorin-containing extracellular matrix produced by cultured skin fibroblasts, whereas beads coated with OspC did not . Taken together, these data suggest that Dbps are adhesins of the MSCRAMM (microbial surface component-recognizing adhesive matrix molecule) family, which mediate B . burgdorferi attachment to the extracellular matrix of the host.

Oral Microbiol Immunol, 1998 Aug, 13(4), 231 - 7
Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults; Mombelli A et al.; The aim of this study was to determine the presence or absence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in young Chinese adults and to examine the A . actinomycetemcomitans isolates from positive subjects with regard to the serotype distribution, presence of the leukotoxin gene lktA and the promoter for the leukotoxin operon as well as the incidence of phage Aa phi 23 . Sixty subjects, working in a knitting factory in the Province of Guangzhou, People's Republic of China, were investigated . Subgingival microbial samples were taken from both upper first molars . They were cultured both anaerobically and in 5% CO2 . P . gingivalis was found in 33 subjects . On average, it constituted 7% of the total anaerobic cultivable counts . A . actinomycetemcomitans was detected in 37 subjects of which seven yielded counts > 10(5) . Twenty-one subjects were positive for both organisms . A . actinomycetemcomitans serotype a was found in 9 subjects, serotype c was found in 23 and serotype e in 5 . A . actinomycetemcomitans serotypes b and d were not detected in any subjects . Presence of the leukotoxin gene lktA was demonstrated for all A . actinomycetemcomitans isolates; however, none of the A . actinomycetemcomitans strains from the present study had a deletion in the promoter region of the leukotoxin operon . The results of this investigation show a high frequency of the putative periodontal pathogens P . gingivalis and A . actinomycetemcomitans and corroborate the concept that there is variation in virulence and pathogenic potential among isolates from different subjects.

Int J Periodontics Restorative Dent, 1998 Oct, 18(5), 474 - 87
Oral tissue reactions to suture materials; Selvig KA et al.; Tissue reactions to natural and synthetic braided and monofilament suture materials in gingiva and oral mucosa were studied . A total of 138 sutures made of four commonly used materials were placed in the edentulous ridges and vestibular mucosa of eight beagle dogs . Biopsy specimens including the suture loop and surrounding tissues were obtained after 3, 7, and 14 days and processed for histologic analysis . The inflammatory reaction was more rapid and intense than the reaction that has been reported after suture placement in skin . Bacterial invasion of the suture track was a common sequela regardless of the material used, but it was particularly prominent for silk . The formation of a perisutural epithelial sleeve was well under way at 3 days and in some instances included the entire suture track within 7 days . Connective tissue reactions consisted of several well-defined, concentric perisutural zones . At 14 days, these zones were partly replaced by granulation tissue surrounded by a fibrous capsule . The synthetic monofilament suture elicited a mild inflammatory tissue response . The results showed that sutures placed in gingiva and oral mucosa produce a prolonged tissue response that is most likely a result of the continual influx of microbial contamination along the suture channel, which may be a lesser problem when sutures are placed in other surgical compartments . The results indicate that chromic gut sutures are rapidly and unpredictably absorbed when used in an environment characterized by moisture and infectious potential.

Int J Circumpolar Health, 1998, 57 Suppl 1, 211 - 4
Ooligan grease: a traditional food fat of western Canada and Alaska; Kuhnlein HV et al.; First Nations Peoples prepare ooligan grease by ripening several tons of the small fish, Thaleichthys pacificus, and rendering the fish oil . Eighteen samples from different family preparations of five cultural areas were analyzed for a spectrum of nutrients, organochlorines, and heavy metals . Ooligan grease was found to be a rich source of retinol (2444 +/- 1198 RE/100 g) and n-3 fatty acids, but had less vitamin A compared to fat of raw fish . There was a 10-fold increase in n-3 fatty acids in grease compared to raw fish fat, which may be attributed to microbial conversion of other fatty acids to DHA . Whole fish were good sources of Ca, Fe, and Zn; heavy metals were below guideline levels in grease . Chlorinated pesticides and PCB increased from north to south locations in British Columbia, with mean levels being 110 ng/g lipid of total chlorinated pesticides and 30 ng/g lipid of PCB . These levels are below regulation limits established by Health Canada . It is concluded that ooligan grease is a superior food fat and safe for human consumption.

J Biol Chem, 1999 Apr 2, 274(14), 9494 - 502
Transient and steady-state kinetics of the oxidation of substituted benzoic acid hydrazides by myeloperoxidase; Burner U et al.; Myeloperoxidase is the most abundant protein in neutrophils and catalyzes the production of hypochlorous acid . This potent oxidant plays a central role in microbial killing and inflammatory tissue damage . 4-Aminobenzoic acid hydrazide (ABAH) is a mechanism-based inhibitor of myeloperoxidase that is oxidized to radical intermediates that cause enzyme inactivation . We have investigated the mechanism by which benzoic acid hydrazides (BAH) are oxidized by myeloperoxidase, and we have determined the features that enable them to inactivate the enzyme . BAHs readily reduced compound I of myeloperoxidase . The rate constants for these reactions ranged from 1 to 3 x 10(6) M-1 s-1 (15 degrees C, pH 7.0) and were relatively insensitive to the substituents on the aromatic ring . Rate constants for reduction of compound II varied between 6.5 x 10(5) M-1 s-1 for ABAH and 1.3 x 10(3) M-1 s-1 for 4-nitrobenzoic acid hydrazide (15 degrees C, pH 7.0) . Reduction of both compound I and compound II by BAHs adhered to the Hammett rule, and there were significant correlations with Brown-Okamoto substituent constants . This indicates that the rates of these reactions were simply determined by the ease of oxidation of the substrates and that the incipient free radical carried a positive charge . ABAH was oxidized by myeloperoxidase without added hydrogen peroxide because it underwent auto-oxidation . Although BAHs generally reacted rapidly with compound II, they should be poor peroxidase substrates because the free radicals formed during peroxidation converted myeloperoxidase to compound III . We found that the reduction of ferric myeloperoxidase by BAH radicals was strongly influenced by Hansch's hydrophobicity constants . BAHs containing more hydrophilic substituents were more effective at converting the enzyme to compound III . This implies that BAH radicals must hydrogen bond to residues in the distal heme pocket before they can reduce the ferric enzyme . Inactivation of myeloperoxidase by BAHs was related to how readily they were oxidized, but there was no correlation with their rate constants for reduction of compounds I or II . We propose that BAHs destroy the heme prosthetic groups of the enzyme by reducing a ferrous myeloperoxidase-hydrogen peroxide complex.

Philos Trans R Soc Lond B Biol Sci, 1999 Jan 29, 354(1379), 111 - 9
How microbial ancient DNA, found in association with human remains, can be interpreted; Rollo F et al.; The analysis of the DNA of ancient micro-organisms in archaeological and palaeontological human remains can contribute to the understanding of issues as different as the spreading of a new disease, a mummification process or the effect of diets on historical human populations . The quest for this type of DNA, however, can represent a particularly demanding task . This is mainly due to the abundance and diffusion of bacteria, fungi, yeasts, algae and protozoans in the most diverse environments of the present-day biosphere and the resulting difficulty in distinguishing between ancient and modern DNA . Nevertheless, at least under some special circumstances, by using rigorous protocols, which include an archaeometric survey of the specimens and evaluation of the palaeoecological consistency of the results of DNA sequence analysis, glimpses of the composition of the original microbial flora (e.g . colonic flora) can be caught in ancient human remains . Potentials and pitfalls of this research field are illustrated by the results of research works performed on prehistoric, pre-Columbian and Renaissance human mummies.

Poult Sci, 1999 Mar, 78(3), 366 - 77
Microbial phytase in finisher diets of White Pekin ducks: effects on growth performance, plasma phosphorus concentration, and leg bone characteristics; Orban JI et al.; Two experiments (Exp.) were conducted to determine the growth response of White Pekin ducks to inclusion of microbial phytase in finisher diet . In Exp . 1, 1-d-old male ducks (240 total) were reared in litter-floor pens and fed regular starter diet until 3 wk of age . At 3 wk of age, ducks were randomly divided into six groups of 10 ducks each and each group was fed one of four diets . Three finisher diets containing 16% CP and 0.18% available phosphorus (AP) without supplemental P were formulated with microbial phytase (Natuphos) added at 0, 750, or 1,500 phytase units/kg of diet . The fourth diet was a control finisher diet that was supplemented with dicalcium phosphate (DCP) to supply dietary AP of 0.41% . Group BW and feed intake were measured weekly to assess growth response . At 6 wk of age, leg bones (tibia, femur, metatarsus) from five randomly selected ducks were removed and analyzed for bone characteristics . In Exp . 2, a total of 120 ducks reared as in Exp . 1 were randomly divided into six groups of five ducks each and fed one of four diets . A basal finisher diet was formulated to contain 16% CP and 0.18% AP . Monosodium phosphate was added to the basal diet to give dietary AP levels of 0.18, 0.27, and 0.36% . The fourth diet was the basal diet supplemented with microbial phytase (750 phytase units/kg of diet) . Ducks were fed these diets from 3 to 6 wk of age . At the end of the study, ducks were bled by cardiac puncture and blood plasma was analyzed for P concentration . Leg bones from all ducks were removed and analyzed for bone characteristics as in Exp . 1 . Feed intake increased linearly with increased level of dietary phytase, whereas the weight gain response was quadratic only during the last week of Exp . 1 . In Exp . 2, there was a quadratic response for weight gain due to dietary AP . Weight gain due to phytase (750 units) was not different from ducks fed diets at 0 or 0.18% AP . Plasma P concentration increased linearly as dietary AP increased . Plasma P levels of ducks fed phytase were similar to those of ducks fed 0.18% AP but lower than in ducks fed 0.27% AP . Estimates of AP resulting from the addition of 750 units of phytase to basal diet were 0.05 and 0.07% based on plasma P concentration and weight gain, respectively . Using regression analysis, the AP due to phytase effect in the diet was estimated to range from 0.06 to 0.08% . Results suggest that phytase can be used in finisher diets similar to the one used in this study for ducks from 3 to 6 wk of age to improve growth performance and leg bone development similar to ducks fed diets supplemented with P from inorganic sources.

Lab Anim Sci, 1998 Jun, 48(3), 228 - 33
Xenotransplant-associated infections; Michaels MG; Xenotransplantation is considered increasingly as a solution to the current shortage of human organs for allotransplantation . In addition, it is being investigated as a treatment for a number of other diseases such as Parkinson's disease, diabetes mellitus, and acquired immunodeficiency disease . The potential risk of novel zoonotic infections is a concern associated with these procedures . Accordingly, the role of animal microbial agents must be critically examined . This review examines the concerns and proposed mechanisms for xenogeneic infections and details what is known and what still needs to be learned as the field of xenotransplantation progresses . Emphasis is placed on microbial agents of baboons and swine because they are currently the most common species considered as donor sources for xenotransplantation.

Arch Anat Cytol Pathol, 1999, 47(1), 38 - 43
{Primary gastric MALT lymphoma in children . Report of 2 cases}; Mezlini A et al.; Primary gastric MALT non-Hodgkin's lymphoma is rare in immunocompetent children . To our knowledge, only two cases have been previously described . We report two cases of gastric MALT lymphoma associated with Helicobacter pylori . Clinico-pathological features are similar to those observed in adults . The relationship between the microbial infection and non-Hodgkin's lymphoma development is discussed.

Int J Mol Med, 1999 Apr, 3(4), 343 - 53
CD40-CD154 interaction in experimental and human disease (review); Biancone L et al.; Cell-to-cell signals between T lymphocytes and antigen-presenting cells strictly regulate the development of the immune response . It has clearly emerged that among these signals few cell surface receptor-ligand pairs, such as CD40 and its ligand, CD154, are mandatory for the induction of lymphocyte activation . The early observation that mutations of CD154 gene are responsible for a human severe immunodeficiency primed an impressive number of studies aimed to functionally characterize this receptorial system in view of therapeutically exploiting its properties . Indeed, various approaches aimed to disrupt natural CD40-CD154 interaction were highly effective in the prevention and treatment of several experimental models of autoimmune disease and transplant rejection . In parallel, abnormalities of this pathway were constantly found in several immunologically-mediated human diseases . Furthermore, a number of studies have dissected the role of CD40 and its ligand in the immune response against various microbial and viral pathogens . Since these molecules are often expressed by tumor cells, it is not surprising that great efforts have been made to address their function also in the development of cancer . Most recent data strongly suggest an involvement of endothelial CD40 in the vascular processes that lead to atherogenesis . This review focuses on the most significant advances in the understanding of the molecular regulatory events involving CD40 and its ligand in experimental and human disease.

Infect Immun, 1999 Apr, 67(4), 1757 - 62
A novel urease-negative Helicobacter species associated with colitis and typhlitis in IL-10-deficient mice; Fox JG et al.; A spiral-shaped bacterium with bipolar, single-sheathed flagella was isolated from the intestines of IL-10 (interleukin-10)-deficient (IL-10(-/-)) mice with inflammatory bowel disease . The organism was microaerobic, grew at 37 and 42 degrees C, and was oxidase and catalase positive but urease negative . On the basis of 16S rRNA gene sequence analysis and biochemical and phenotypic criteria, the organism is classified as a novel helicobacter . Cesarean section-rederived IL-10(-/-) mice without helicobacter infection did not have histological evidence of intestinal inflammation . However, helicobacter-free IL-10(-/-), SCID/NCr, and A/JNCr mice experimentally inoculated with the novel urease-negative Helicobacter sp . developed variable degrees of inflammation in the lower intestine, and in immunocompetent mice, the experimental infection was accompanied by a corresponding elevated immunoglobulin G antibody response to the novel Helicobacter sp . antigen . These data support other recent studies which demonstrate that multiple Helicobacter spp . in both naturally and experimentally infected mice can induce inflammatory bowel disease . The mouse model of helicobacter-associated intestinal inflammation should prove valuable in understanding how specific microbial antigens influence a complex disease process.

Infect Immun, 1999 Apr, 67(4), 1702 - 7
Differential protective efficacy of DNA vaccines expressing secreted proteins of Mycobacterium tuberculosis; Kamath AT et al.; The development of more-effective antituberculosis vaccines would assist in the control of the global problem of infection with Mycobacterium tuberculosis . One recently devised vaccination strategy is immunization with DNA plasmids encoding individual microbial genes . Using the genes for the M . tuberculosis secreted proteins MPT64 (23 kDa), Ag85B (30 kDa), and ESAT-6 (6 kDa) as candidate antigens, DNA vaccines were prepared and tested for immunogenicity and protective efficacy in a murine model of aerosolized tuberculosis (TB) . Intramuscular immunization with DNA-64 or DNA-85B resulted in the activation of CD4(+) T cells, which produce gamma interferon (IFN-gamma), and high titers of specific immunoglobulin G antibodies . Further, DNA-64 induced major histocompatibility complex class I-restricted CD8(+) cytotoxic T cells . The addition of a eukaryotic leader sequence to mpt64 did not significantly increase the T-cell or antibody response . Each of the three DNA vectors stimulated a significant reduction in the level of M . tuberculosis infection in the lungs of mice challenged 4 weeks after immunization, but not to the levels resulting after immunization with Mycobacterium bovis BCG . The vaccines showed a consistent hierarchy of protection, with the most effective being Ag85B, followed by ESAT-6 and then MPT64 . Coimmunization with the three vectors resulted in a greater degree of protection than that induced by any single vector . This protective efficacy was associated with the emergence of IFN-gamma-secreting T cells earlier than in infected animals immunized with a control vector . The efficacy of these DNA vaccines suggests that multisubunit vaccination may contribute to future vaccine strategies against TB.

Kidney Int Suppl, 1999 Mar, 69, S125 - 30
Iron and infection; Patruta SI et al.; Intravenous iron therapy maintains iron stores and decreases erythropoietin demand in patients undergoing regular dialysis therapy . Microbiology studies show a close relationship between the availability of iron and bacterial virulence . Iron is also an essential requirement of bacteria for multiplication in the host . Therefore, clinical conditions associated with iron excess in the host may increase the risk for infection . Parenteral iron has already been shown in human and animal studies to be harmful when administered during infection . There is now convincing evidence that hydroxyl radicals, produced either by the Fenton reaction or by the iron-catalyzed Haber-Weiss reaction, are species responsible for the damaging effects of iron . The unavailability of iron limits microbial growth but also impairs host resistance . In end-stage renal disease, patients' overtreatment with iron enhances the pre-existing risk for infectious complications caused by dialysis procedure per se, malnutrition, increased intracellular calcium, as well as low and high molecular weight uremic toxins . Intravenous iron therapy may not only adversely affect phagocytes in end-stage renal disease patients, but also T and B lymphocytes.

J Infect Dis, 1999 Mar, 179 Suppl 2, S331 - 7
How intestinal bacteria cause disease; Guerrant RL et al.; An improved understanding of how intestinal bacteria cause disease has become increasingly important because of the emergence of new enteric pathogens, increasing threats of drug resistance, and a growing awareness of their importance in malnutrition and diarrhea . Reviewed here are the varied ways that intestinal bacteria cause disease, which provide fundamental lessons about microbial pathogenesis as well as cell signaling . Following colonization, enteric pathogens may adhere to or invade the epithelium or may produce secretory exotoxins or cytotoxins . In addition, by direct or indirect effects, they may trigger secondary mediator release of cytokines that attract inflammatory cells, which release further products, such as prostaglandins or platelet-activating factor, which can also trigger secretion . An improved understanding of pathogenesis not only opens new approaches to treatment and control but may also suggest improved simple means of diagnosis and even vaccine development.

J Microencapsul, 1999 Mar-Apr, 16(2), 243 - 50
Ocular drug targeting by liposomes and their corneal interactions; Velpandian T et al.; Topical drug delivery is preferred in the eye to avoid under or over medication and undesired side effects of systemic administration . In order to maintain adequate drug levels in ocular tissues, frequent drug installation is necessary in vision threatening conditions like glaucoma, corneal ulcers due to microbial infections, etc . Only a part of the installed drug reaches the aqueous humor and the rest of it is drained by the nasolacrimal duct . Positively charged liposomes have been found to enhance the penetration of drugs into the cornea . The present study was conducted to visualize the interaction of liposomes with the cornea . Briefly, positively charged liposomes entrapped with Carboxyfluorescein (CF), Propidium iodide (PI), Horseradish peroxidase (HRP), Biotin, Hydroxy benzimide (Hoechst No: 33258), and Ethoxy benzimide (Hoechst No: 33342) were prepared by sonication . Their size and shape were analysed by laser dynamic light spectra and electron microscopy, respectively . The liposome encapsulated and free materials in buffer were instilled, in a volume of 20 microliters, into eyes of anesthetized albino rats . After 30 min and 1 h, the eyes were enucleated and quickly processed for cryosections of 3-5 microns thickness . The interaction of liposome entrapped propidium iodide and HRP was visualized on the outer epithelium of the cornea after specific processing.

Cleve Clin J Med, 1999 Mar, 66(3), 173 - 80
Evolving concepts in the management of patients with neutropenia and fever; Avery RK et al.; Much has changed in the treatment of patients with fever and neutropenia, including the patterns of microbial flora and drug resistance and the drugs used . More patients now have indwelling central venous catheters, exposing them to new types of infections . This article reviews the recent treatment guidelines published by the Infectious Diseases Society of America.

J Mol Recognit, 1998 Winter, 11(1-6), 240 - 2
Preliminary studies on the purification of a monoclonal antibody by affinity precipitation with Eudragit S-100; Taipa MA et al.; A simple procedure for the purification of an IgG-type monoclonal antibody by affinity precipitation using Eudragit S-100 is presented . The ligand, a microbial lipase previously used as antigen, was coupled to the polymer at a concentration of 40 mg lipase/g Eudragit . This macroligand was reversibly precipitated by manipulating the pH at values higher and lower than 4.8 . The effects of polymer concentration and dilution of hybridoma culture supernatant on the overall precipitation process were evaluated . The best purification factor was achieved with a polymer concentration of 0.1% (w/v) and a supernatant dilution of 1:3 . The preliminary studies reported here enabled the purification of a monoclonal antibody in one step with an activity yield (by ELISA) of 50%-55% and a purification factor of ca 6.

J Mol Recognit, 1998 Winter, 11(1-6), 217 - 21
The use of affinity adsorbents in expanded bed adsorption; Chase HA; The potential for the use of affinity ligands in expanded bed adsorption (EBA) procedures is reviewed . The use of affinity ligands in EBA may improve its use in direct recovery operations, as the enhanced selectivity of the adsorbent permits selective capture of the target from complex feedstocks and high degrees of purification . The properties of ligands suitable for use in EBA processes are identified and illustrated with examples . In addition to its use in the recovery of soluble products, such as proteins and nucleic acids, from particulate feedstocks, EBA can also be used to recover particulate entities, such as cells and packaged DNA (viruses and phages), from feedstocks . Affinity ligands coupled to appropriate chosen support materials will be required for such processes in order to achieve the necessary selectivity for the required particulate entity . The latter point is illustrated by the use of proteinaceous ligands immobilized to perfluorocarbon emulsions to achieve separations of microbial cells.

J Chemother, 1999 Feb, 11(1), 28 - 33
The increase in carbapenem use and emergence of Stenotrophomonas maltophilia as an important nosocomial pathogen; Sanyal SC et al.; Carbapenems, being the broadest spectrum antibiotics, may allow those organisms intrinsically resistant to these drugs to be involved more frequently in nosocomial infections . Imipenem was introduced to the specialized hospital units in Kuwait in October, 1992 and meropenem in late 1996 . The main objective of this study was to observe prospectively whether, under similar laboratory conditions for microbial isolation/identification while these drugs are in use in the hospital, there is any proportional increase over time in the recovery of Stenotrophomonas maltophilia in relation to the number of yearly admissions and drug use . In addition, we also looked for categories of patients infected by S . maltophilia, type of infection and antibiotic susceptibility . There was an increase in the number of S . maltophilia isolates from 1993 to 1997 significantly correlated with the increase in year-wise consumption of carbapenems (p<0.004) . No correlation was observed between yearly number of admissions and both the consumption of carbapenems (p>0.51) and isolation of the organism (p>0.59) . Most isolates were from cancer, burns and cardiac patients . The commonest types of infection were wound and septicemia . The organisms were susceptible mostly to ciprofloxacin and co-trimoxazole . The study thus indicates that carbapenem use in a hospital environment may result in emergence of nosocomial infections due to multiresistant S . maltophilia in high risk patients with very limited choice of antibiotics for therapy.

Appl Microbiol Biotechnol, 1999 Jan, 51(1), 105 - 11
Bioavailability of hydrocarbons during microbial remediation of a sandy soil; Loser C et al.; The microbial degradation of hydrocarbons was studied in an artificially contaminated sandy soil, using a pilot-scale percolator system . After a short lag period, an intensive degradation occurred, which diminished in time and completely stopped in the end, despite large residual contaminations (residues of 56% diesel fuel, 20% n-hexadecane and 3.5% phenanthrene at the initial loadings of each 3000 mg/kg) . The remaining pollutant content was influenced by the kind of hydrocarbon but was nearly independent of its initial loading . According to a model-aided analysis of the carbon dioxide production during remediation, the observed stagnation of degradation was caused by a limited bioavailability of the pollutants . The degradation in the soil-free aqueous phase was more extensive than in the soil, which suggests that the limited bioavailability in the soil can be attributed mainly to matrix-dependent rather than substrate-dependent influences . Generally, fine particles and organic matter are mainly responsible for the adsorption of pollutants to the soil matrix . Our sandy soil also bound hydrocarbons adsorptively although it contained neither silty material nor significant amounts of organic matter . As shown by Brunauer Emmett Teller (BET) analysis, the soil particles were covered by micropores, which enlarged the soil surface by a factor of 120 in comparison with the macroscopic surface area . The microporosity is the reason for the hydrocarbons being more strongly adsorbed to the sandy soil than expected.

Appl Microbiol Biotechnol, 1999 Jan, 51(1), 22 - 32
Rhamnose lipids--biosynthesis, microbial production and application potential; Lang S et al.; Biosurfactants containing rhamnose and beta-hydroxydecanoic acid and called rhamnolipids are reviewed with respect to microbial producers, their physiological role, biosynthesis and genetics, and especially their microbial overproduction, physicochemical properties and potential applications . With Pseudomonas species, more than 100 g l-1 rhamnolipids were produced from 160 g l-1 soybean oil at a volumetric productivity of 0.4 g l-1 h-1 . The individual rhamnolipids are able to lower the surface tension of water from 72 mN m-1 to 25-30 mN m-1 at concentrations of 10-200 mg l-1 . After initial testing, rhamnolipids seem to have potential applications in combating marine oil pollution, removing oil from sand and in combating zoosporic phytopathogens . Rhamnolipids are also a source of L-rhamnose, which is already used for the industrial production of high-quality flavor components.

Genome Res, 1999 Mar, 9(3), 297 - 307
Analysis of sequence-tagged-connector strategies for DNA sequencing; Siegel AF et al.; The BAC-end sequencing, or sequence-tagged-connector (STC), approach to genome sequencing involves sequencing the ends of BAC inserts to scatter sequence tags (STCs) randomly across the genome . Once any BAC or other large segment of DNA is sequenced to completion by conventional shotgun approaches, these STC tags can be used to identify a minimum tiling path of BAC clones overlapping the nucleation sequence for sequence extension . Here, we explore the properties of STC-sequencing strategies within a mathematical model of a random target with homologous repeats and imperfect sequencing technology to understand the consequences of varying various parameters on the incidence of problem clones and the cost of the sequencing project . Problem clones are defined as clones for which either (A) there is no identifiable overlapping STC to extend the sequence in a particular direction or (B) the identified STC with minimum overlap comes from a nonoverlapping clone, either owing to random false matches or repeat-family homology . Based on the minimum overlap, we estimate the number of clones to be entirely sequenced and, then, using cost estimates, identify the decision rule (the degree of sequence similarity required before a match is declared between an STC and a clone) to minimize overall sequencing cost . A method to optimize the overlap decision rule is highly desirable, because both the total cost and the number of problem clones are shown to be highly sensitive to this choice . For a target of 3 Gb containing approximately 800 Mb of repeats with 85%-90% identity, we expect <10 problem clones with 15 times coverage by 150-kb clones . We derive the optimal redundancy and insert sizes of clone libraries for sequencing genomes of various sizes, from microbial to human . We estimate that establishing the resource of STCs as a means of identifying minimally overlapping clones represents only 1%-3% of the total cost of sequencing the human genome, and, up to a point of diminishing returns, a larger STC resource is associated with a smaller total sequencing cost.

J Microbiol Methods, 1999 Feb, 35(1), 37 - 42
Impedance microbiology: quantification of bacterial content in milk by means of capacitance growth curves; Felice CJ et al.; The impedancimetric method is a technique for the rapid evaluation of milk bacterial content and also of its subproducts . Several authors have made use of culture conductance changes during bacterial growth for quantitative and qualitative assessments of microbial growth . However, interface capacitance curves, Ci, have not been used . In this paper, we quantify bacteria in cow raw milk by following their growth as the above-mentioned capacitance change time course event . With it, bigger growth variations, shorter detection times and a better coefficient of correlation with the plate count method were obtained than those yielded by conductance curves . Calibration was performed by plotting initial known concentrations, IC (CFU/ml), as a function of the time detection theshold (TDT).

J Exp Med, 1999 Mar 15, 189(6), 999 - 1004
A critical role for the RelA subunit of nuclear factor kappaB in regulation of multiple immune-response genes and in Fas-induced cell death; Ouaaz F et al.; Binding sites for the nuclear factor (NF)-kappaB transcription factor have been identified within control regions of many genes involved in inflammatory and immune responses . Such kappaB sites are often found adjacent to those of interferon (IFN)-gamma-inducible transcription factors, suggesting a requirement for multiple signaling pathways for gene regulation . Using fibroblasts from RelA (p65)-deficient mice generated by gene targeting, we have investigated the role of this subunit of NF-kappaB in gene activation by microbial lipopolysaccharide, tumor necrosis factor alpha, and in possible synergism with the IFN-gamma-signaling pathway . Our results indicate not only that RelA is required for activation of key genes involved in adaptive (acquired) immune responses, including major histocompatibility complex class I, CD40, and the Fas death receptor, but also that both NF-kappaB-inducing signals and IFN-gamma are necessary for maximal activation . In contrast, neutrophil-specific chemokine genes KC and MIP-2, which can function as nonspecific mediators in innate immune responses, were strongly induced by RelA in the absence of IFN-gamma . Our results show that RelA plays a critical role in activation of immune system genes in response to nonspecific stimuli and demonstrate a novel proapoptotic function for this protein in Fas-induced cell death.

Biotechnol Appl Biochem, 1999 Apr, 29 ( Pt 2), 119 - 31
The realm of microbial lipases in biotechnology; Pandey A et al.; In this review, a comprehensive and illustrious survey is made of the applied aspects of microbial lipases in modern biotechnological practices . Lipases are the most versatile biocatalyst and bring about a range of bioconversion reactions such as hydrolysis, interesterification, esterification, alcoholysis, acidolysis and aminolysis . After a brief description of the microbial sources of lipases, the pivotal role of lipases in the processes and products of the food and flavourings industry is illustrated . An illustration is presented of biomedical applications . The panorama of lipases in the manufacture of fine chemicals is depicted with special emphasis on pharmaceuticals, pesticides, cosmetics, biosensors and detergents . Widening applications such as those in waste management and improved tanning techniques are other novel aspects of lipase utilization that are discussed in this review.

Microbiology, 1999 Feb, 145 ( Pt 2), 411 - 7
Molecular evidence for the existence of additional members of the order Chlamydiales; Ossewaarde JM et al.; Respiratory tract infections in man may be caused by several members of the genus Chlamydia and also by two Chlamydia-like strains, 'Simkania negevensis' (Z-agent) and 'Parachlamydia acanthamoebae' (Bng) . To facilitate diagnostic procedures a PCR assay able to detect all known Chlamydiaceae sequences in one reaction was developed . For this purpose, primers were selected to amplify a fragment of the 16S rRNA gene . Characterization of the amplified fragments was done by hybridization with specific probes and by sequencing . PCR assays were carried out using DNA isolated from nose/throat specimens or from peripheral blood mononuclear cells of patients with respiratory tract infections, and from vessel wall specimens of abdominal aneurysms . Six of the 42 nose/throat swab specimens analysed yielded strong bands and one yielded a faint band . Three of these bands were identified as Chlamydia pneumoniae and one as Chlamydia trachomatis by sequencing . Analysis of the three other bands yielded two different new sequences . DNA isolated from peripheral blood mononuclear cells of one patient yielded a third new sequence . DNA isolated from peripheral blood mononuclear cells of four healthy controls was negative . One of the abdominal aneurysm specimens also yielded a strong band . Sequencing revealed a fourth new sequence . All negative controls included during specimen processing and PCR analysis remained negative . The typical secondary structure of microbial 16S genes was present in all four new sequences indicating the validity of the sequence data . All four new sequences were distinct from other bacteria and clustered together with known Chlamydiaceae sequences . Phylogenetic analysis suggested a new lineage, separating the four new sequences, 'S . negevensis' and 'P . acanthamoebae' from the genus Chlamydia with the four known chlamydial species . In conclusion, this study provides evidence for the existence of several new members of the order Chlamydiales . Since the source of the Chlamydia-like strains has not been identified and serological and/or molecular cross-reactivities may be expected, results of identification of infecting recognized organisms should be interpreted cautiously.

Am J Physiol, 1999 Mar, 276(3 Pt 2), R864 - 71
Role of central melanocortins in endotoxin-induced anorexia; Huang QH et al.; Inflammation and microbial infection produce symptoms, including fever, anorexia, and hypoactivity, that are thought to be mediated by endogenous proinflammatory cytokines . Melanocortins are known to act centrally to suppress effects on fever and other sequelae of proinflammatory cytokine actions in the central nervous system, but the roles of melanocortins in anorexia and hypoactivity occurring during the acute phase response are unknown . The present study was designed to determine the effects of exogenous and endogenous alpha-melanocyte stimulating hormone (alpha-MSH) on lipopolysaccharide (LPS)-induced anorexia in relation to their effects on fever . Rats were fasted overnight to promote feeding behavior, then injected intraperitoneally with LPS (100 micrograms/kg ip), followed 30 min later by intracerebroventricular injection of either alpha-MSH or the melanocortin receptor subtype 3/subtype 4 (MC3-R/MC4-R) antagonist SHU-9119 . Food intake, locomotor activity, and body temperature (Tb) were monitored during the ensuing 24-h period . Each of two intracerebroventricular doses of alpha-MSH (30 and 300 ng) potentiated the suppressive effects of LPS on food intake and locomotion, despite the fact that the higher dose alleviated LPS-induced fever . In control rats that were not treated with LPS, only the higher dose of alpha-MSH significantly inhibited food intake, and Tb and locomotor activity were unaffected . To assess the roles of endogenous central melanocortins, LPS-treated rats received intracerebroventricular SHU-9119 (200 ng) . Central MC3-R/MC4-R blockade did not affect Tb or food intake in the absence of LPS treatment, but it reversed the LPS-induced reduction in 24-h food intake and increased LPS-induced fever without altering the LPS-induced suppression of locomotion . Taken together, the results suggest that exogenous and endogenous melanocortins acting centrally exert divergent influences on different aspects of the acute phase response, suppressing LPS-induced fever but contributing to LPS-induced anorexia and hypoactivity.

J Dairy Sci, 1999 Feb, 82(2), 391 - 403
Effects of an enzyme feed additive on extent of digestion and milk production of lactating dairy cows; Yang WZ et al.; A study was conducted using lactating Holstein cows with ruminal and duodenal cannulas in a 4 x 4 Latin square design to investigate fibrolytic enzyme supplementation on site and extent of nutrient digestion . The four diets consisted of 45% concentrate, 10% barley silage, and 45% cubed alfalfa hay (dry matter basis) and differed in enzyme supplementation: 1) control cubes, 2) cubes treated with 1 g of enzyme mixture/kg of cubes, 3) cubes treated with 2 g of enzyme mixture/kg of cubes, and 4) both concentrate and cubes treated with 1 g of enzyme mixture/kg of dry matter . The enzyme supplement contained primarily cellulase and xylanase activities . Digestion of organic matter and neutral detergent fiber in the total tract was higher for cows fed the high dosage of enzyme than for cows fed the control cubes . Ruminal digestibility of crude protein was higher, but that of organic matter and neutral detergent fiber was only numerically higher, for cows fed the high dosage of enzyme compared with that of cows fed the control cubes . Higher ruminal digestibility associated with the high dosage of enzyme resulted in more microbial protein synthesis . Milk production increased for cows fed the high dosage of enzyme compared with cows fed the control cubes and effects of the addition of enzyme on milk composition were minimal . The results demonstrated the benefits of using a fibrolytic enzyme additive to enhance feed digestion and milk production by dairy cows . The response to enzyme supplementation was affected more by amount of enzyme than by whether the enzyme was added to forage or concentrate.

Bioinformatics, 1999 Jan, 15(1), 2 - 15
Imagene: an integrated computer environment for sequence annotation and analysis; Medigue C et al.; MOTIVATION: To be fully and efficiently exploited, data coming from sequencing projects together with specific sequence analysis tools need to be integrated within reliable data management systems . Systems designed to manage genome data and analysis tend to give a greater importance either to the data storage or to the methodological aspect, but lack a complete integration of both components . RESULTS: This paper presents a co-operative computer environment (called Imagenetrade mark) dedicated to genomic sequence analysis and annotation . Imagene has been developed by using an object-based model . Thanks to this representation, the user can directly manipulate familiar data objects through icons or lists . Imagene also incorporates a solving engine in order to manage analysis tasks . A global task is solved by successive divisions into smaller sub-tasks . During program execution, these sub-tasks are graphically displayed to the user and may be further re-started at any point after task completion . In this sense, Imagene is more transparent to the user than a traditional menu-driven package . Imagene also provides a user interface to display, on the same screen, the results produced by several tasks, together with the capability to annotate these results easily . In its current form, Imagene has been designed particularly for use in microbial sequencing projects . AVAILABILITY: Imagene best runs on SGI (Irix 6.3 or higher) workstations . It is distributed free of charge on a CD-ROM, but requires some Ilog licensed software to run . Some modules also require separate license agreements . Please contact the authors for specific academic conditions and other Unix platforms . CONTACT: imagene home page: http://wwwabi.snv.jussieu.fr/imagene

Vaccine, 1999 Feb 26, 17(7-8), 867 - 74
Vaccination against tick-borne encephalitis under therapeutic immunosuppression . Reduced efficacy in heart transplant recipients; Dengler TJ et al.; Patients after organ transplantation are at an increased risk of microbial infections and might benefit from active vaccination . Due to therapeutic immunosuppression the efficacy of immunizations is, however, reduced and difficult to predict . Efficacy of vaccination against tick-borne encephalitis (TBE) using an abbreviated immunization schedule was compared in 31 heart transplant recipients (age: 54.5 +/- 11.5 years, mean time after transplantation: 53.5 +/- 23.7 months) under cyclosporine-based immunosuppression and 29 controls . TBE vaccination was well tolerated by the transplant recipients; spectrum and frequency of adverse events were similar to controls . In the transplant patients, seroconversion rate (35% versus 100%; p < 0.001) and the geometric mean of post-vaccinal antibody titres (0.98 (SF: 2.3) U/ml versus 5.46 (2.2) U/ml; p < 0.001) were markedly reduced in comparison to the control group . No clinical or demographic predictors of vaccination success could be established in the transplant patients . Due to the limited efficacy, TBE vaccination cannot be recommended as a routine procedure in heart transplant recipients at risk of TBE virus infection . TBE vaccination may be performed safely in selected cases, but repeated titre controls to confirm vaccination success would be required.

Stomatologiia (Mosk), 1998, 77(6), 7 - 8
{Changes in the quantitative composition of the microbial flora of dental deposits during the intensification of oral hygiene}; Lukinykh LM et al.; The efficacy of hygienic treatment of the oral cavity in combination with ozone therapy is assessed . This combination mechanically removes soft dental deposit and decreases bacterial contamination.

Curr Opin Plant Biol, 1998 Aug, 1(4), 347 - 52
Transgenic approaches to microbial disease resistance in crop plants; Salmeron JM et al.; Recent progress in the genetic dissection of plant disease resistance signaling pathways has opened a number of new avenues towards engineering pathogen resistance in crops . Genes controlling race-specific and broad-spectrum resistance responses have been cloned, and novel induced resistance pathways have been identified in model and crop systems . Advances continue to be made in identification of antifungal proteins with effects inhibitory to either pathogen development or accumulation of associated mycotoxins.

Curr Opin Microbiol, 1998 Dec, 1(6), 674 - 7
Coordinate control of secondary metabolite production and asexual sporulation in Aspergillus nidulans; Adams TH et al.; Microbial secondary metabolite production is frequently associated with developmental processes such as sporulation, but there are few cases where this correlation is understood . Recent work with the filamentous fungus Aspergillus nidulans has provided new insights into the mechanisms coordinating production of the toxic secondary metabolite sterigmatocystin with asexual sporulation . These processes have been shown to be linked through a common need to inactivate a heterotrimeric G protein dependent signaling pathway that, when active, serves to stimulate growth while blocking both sporulation and sterigmatocystin biosynthesis.

Curr Opin Microbiol, 1998 Jun, 1(3), 359 - 63
Flow cytometry and bacterial pathogenesis; Valdivia RH et al.; Our understanding of microbial adaptations to diverse and threatening environments is limited by the assumption that the behavior of individual bacteria can be accurately determined by measuring the behavior of populations . Recent advances in gene expression reporter systems, fluorescence microscopy and flow cytometry allow microbiologists to explore the complex interactions between bacteria and their environment with single cell resolution . The application of these technologies has been particularly useful in systems, such as host-pathogen interactions, where genetic analysis is often cumbersome . Recently, flow cytometry is increasingly being applied to study host-pathogen interactions.

Curr Opin Microbiol, 1998 Jun, 1(3), 286 - 90
What's up down there?
White DC, Phelps TJ, Onstott TC.
The development of careful quality assurance criteria assuring freedom from contamination in all aspects of sample recovery has opened the window to studies of a fascinating new microbial biome in the deep subsurface . Organisms have been recovered with unusual metabolic capabilities and a chemosynthetic lifestyle independent of the recent surface photosynthetically derived energy inputs . The properties of the subsurface microbiota are critical when assessing aspects such as the utility of burying radioactive waste, the remediation of mixtures of organics, metals, and nuclides, and the search for life in extreme environments on Earth as well as on Mars and other extraterrestrial sites . In addition this pioneering work provides a foundation for examining life processes in extreme environments, such as the environment beneath the ocean floor.

Curr Opin Microbiol, 1998 Jun, 1(3), 296 - 302
Structure and function of anthropogenically altered microbial communities in coastal waters; Paerl HW; Human-based (anthropogenic) nutrient and other pollutant enrichment of the world's coastal waters is causing unprecedented changes in microbial community structure and function . Symptoms of these changes include accelerating eutrophication, the proliferation of harmful microalgal blooms, excessive oxygen consumption (hypoxia, anoxia), increasing toxicity, altered routes and fluxes of organic and inorganic matter cycling, and disruption of food webs . Biogeochemical and trophic consequences are expanding on local, regional and global scalesPublication Types:

	Review
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