J Theor Biol, 1996 Aug 21, 181(4), 343 - 58 Two alternative models for spontaneous flagellar motor switching in Halobacterium salinarium; Naber H; Halobacteria are light-sensitive microorganisms which swim by means of rotating flagella . Under constant environmental conditions, they reverse their swimming direction about every 10-30 s . This is due to spontaneous switchings of the flagellar motors from clockwise to counterclockwise rotation or vice versa . However, it is unknown how the direction of rotation is regulated . In this paper, two stochastic models which could explain the characteristics of sequences of spontaneous switching events are discussed . The process is described in terms of a "motor switch" cyclically running through a sequence of states and triggering a reversal whenever a cycle is complete . Referring to previously stated hypotheses, modelling is based on the assumption that transitions between the states of the switch either occur with constant probability per unit time or are actively regulated by an endogenous biochemical oscillator . It is shown that both models yield a good description of the experimental data, though they are mutually exclusive. Ugeskr Laeger, 1996 Aug 19, 158(34), 4771 - 2 {Diagnosis of secondary aortointestinal fistulae}; Schantz V; A secondary aortoenteric fistula (SAIF) is a direct communication between the gastrointestinal (GI) tract and the aorta in a patient who has undergone major surgery on the aorta, often an aortic graft operation . The cardinal symptoms of a SAIF are septicaemia and/or GI-haemorrhage . In this case, a 40 year old man was admitted to the hospital because of repeated episodes of fever, chills and malaise . The patient had undergone an aortofemoral by-pass graft operation five years previously . Blood cultures showed repeated growth of different enteric-related microorganisms . None of the used diagnostic investigations revealed any signs of infection or fistulation near the aortic graft . After five months of hospitalization an endoscopy revealed the aortic graft protuding into the duodenal lumen, verifying the fistula . If GI-haemorrhage and/or septicaemia arise in a patient who has undergone major surgery on the aorta, one must suspect a secondary aortoenteric fistula and not hesitate too long to perform an explorative laporatomy . If untreated, the mortality rate of the condition is 100%. FEBS Lett, 1996 Aug 19, 392(1), 1 - 5 Purification and characterization of the membrane-bound nitrate reductase isoenzymes of Bradyrhizobium japonicum; Fernandez-Lopez M et al.; Two respiratory membrane-bound nitrate reductase (NR) isoenzymes, NRI and NRII, have been purified for the first time from one single microorganism . Triton X-100-solubilized NRs were purified by a three-step procedure of differential centrifugation, Q-Sepharose chromatography, and gel filtration on Sephacryl S-300 . Both isoenzymes were purified to homogeneity by the criteria of NR activity staining in polyacrylamide gels run under non-denaturating conditions and coincident staining of the protein band by silver nitrate . NRI is composed of three subunits of 116 kDa, 68 kDa, and 56 kDa, whereas NRII is composed of four subunits of 116 kDa, 68 kDa, 59 kDa, and 56 kDa . The 116-kDa subunit of NRI and the 59-kDa subunit of NRII exhibited immunological cross-reactivity with the respiratory NR of Pseudomonas stutzeri strain ZoBell. Orv Hetil, 1996 Aug 4, 137(31), 1699 - 704 {Nitric oxide . Basic research and possible clinical use}; Pronai L et al.; The journal Science considered nitric oxide (NO) the molecule of the year 1992 . This small, instable, potentially toxic gas freely crosses cell membranes . NO is produced from L-arginine by NO-synthase . The various physiological and pathological effects of NO can be explained by its reactivity and different routes of formation and metabolism . In mammals, at least three isoenzymes of NO-synthase (neuronal, endothelial and inducible forms) are known . NO exerts different effects in acidic, neutral and basic pH conditions, it is cell-protective when produced is small quantities whereas it is toxic when exceeds millimolar concentrations . Both the overproduction and suppression of NO release may have harmful effects . As a neurotransmitter, it plays important role in cell-signaling, in the erection of penis and also in the learning process . When produced by endothelial cells, it is a potent vasodilatator, and phagocytes use NO to kill microorganisms . NO also may play pathological role in chronic inflammations, immune processes and tumour generation . Based an our current knowledge, NO can be used in the therapy of pulmonary hypertension, cerebral ischemia and relaxation disturbances of smooth muscle sphincters, and the blockade of NO synthase activity may help in the management of septic shock, hypotension and inflammations. Pract Periodontics Aesthet Dent, 1996 Aug, 8(6), 581 - 4; quiz 584 Clinical management of infected root canal dentin; Love RM; Several hundred different species of bacteria are present in the human intraoral environment . Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system . These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment . The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin . Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required. Genetika, 1996 Aug, 32(8), 1061 - 7 {Mutator genes of the yeast Saccharomyces cerevisiae . Interaction of mutations him and his with mutations blocking three principal pathways of repair of induced DNA damage}; Koval'tsova SV et al.; During recent years, genes controlling mutation in higher eukaryotes have been found to be involved actively in carcinoma regeneration in cells . In this respect, studying the genetic control of mutagenesis becomes a key direction of research into mechanisms responsible for cancer generation . The results of studying interaction of mutations in the HIM and HSM genes, controlling spontaneous and induced mutagenesis in yeasts, and mutations impairing three known pathways of DNA damage repair in this microorganism, are described in this work . It was shown that mutation rev3 completely blocks UV-induced mutagenesis in all mutants studied . On the other hand, mutation rad2 synergistically interacts with mutations him1, hsm1, hsm3, hsm6, and hsm2, thus enhancing the frequency of UV-induced mutagenesis in double mutants multiple times . Mutations him2 and him3 manifested epistatic interaction with mutation rad2 . With mutation rad54, the interaction was epistatic for mutations him1 and hsm2 and was additive for mutations hsm1, him2, and him3 . On the basis of the data obtained, we developed a scheme for the appearance of mismatch bases in the process of repair of UV-induced DNA damage. Eur J Oral Sci, 1996 Aug, 104(4 ( Pt 1)), 327 - 34 Emotional stress effects on immunity, gingivitis and periodontitis; Breivik T et al.; Gingivitis and periodontitis are thought to result from an imbalance between those oral microorganisms which normally colonize tooth surfaces in close contact with the gingival margin, and the nature and efficiency of the host response . The bacteria are the triggering agents, but host defence mechanisms within the gingival/periodontal tissues seem to be responsible for most of the tissue damage and for the outcome and progression of the diseases . It has recently been shown that emotional or psychological load (stress) may influence immune activities directly via nerve messenger substances (neurotransmitters and neuropeptides) and/or indirectly via neuroendocrine (hormone) substances . This review discusses how emotional stressors and nervous and neuroendocrine responses to psychological stressors may modulate the immune response to bacteria, and thus be expected to influence the progression and course of gingivitis and periodontitis. Dermatol Nurs, 1996 Aug, 8(4), 287 - 95 The value and limitations of protective gloves in medical health service: part II; Mellstrom GA et al.; The value of protective gloves in the health care environment is well known . However, these gloves are not perfect . Some are permeable to microorganisms and various chemicals, and/or result in side effects for health care professionals . Gloves that offer the greatest protection and least side effects are highly desirable . Protection against microorganisms and protection against chemicals used in health care are described in Part II of this three-part series. Zentralbl Bakteriol, 1996 Aug, 284(4), 540 - 9 Evaluation of commercial kits for quantitative identification and tests on antibiotic susceptibility of genital mycoplasmas; Abele-Horn M et al.; In this study, commercial media and kits for identification and tests for antibiotic susceptibility of genital mycoplasmas were evaluated in comparison to standardized methods . A total of 298 specimens was routinely enrolled . Our results showed that all media corresponded for qualitative and semiquantitative identification with a specificity of 100% for both microorganisms and a sensitivity of 94% for U . urealyticum and of 88% for M . hominis . Standard methods were superior to commercial kits for qualitative and quantitative identification (sensitivity 85-97% for U . urealyticum and 79-83% for M . hominis) . There were large discrepancies when testing antibiotic susceptibility. Vet Parasitol, 1996 Aug, 64(1-2), 71 - 82 Irradiation as a cold pasteurization process of food; Loaharanu P; A number of emerging pathogenic microorganisms and parasites in food, the wide publicity of outbreaks of foodborne diseases and the increasing number of immuno-compromised population have resulted in a need to develop proper strategies and technologies to protect health of consumers . Regulations in most countries which are promulgated to ensure safety of foods, are not properly enforced to protect consumers' health especially with regard to food of animal origin . While regulations are in place and properly enforced for liquid foods such as milk or fruit juices, more solid foods especially those of animal origin, e.g . poultry, meat and seafood, which are often contaminated by pathogenic microorganisms and parasites, are not similarly regulated . The number of incidences of foodborne diseases can the subsequent economic impact to the society can be enormous . Recently, an increasing number of national and international organizations have recognised the use of irradiation as a method to ensure hygienic quality of more solid food of animal origin in the same manner as thermal pasteurization does for liquid foods . The effectiveness of irradiation as a cold pasteurization method to control foodborne disease caused by pathogenic microorganisms and parasites, especially in food to be consumed raw or partially processed, is established . Its role in overcoming trade barriers of food of animal origin based on the principle of the Agreement on the Application of Sanitary and Phytosanitary Measures, adopted during the GATT Uruguay Round will be discussed. Tissue Antigens, 1996 Aug, 48(2), 127 - 35 Apoptosis following interleukin-2 withdrawal from T cells: evidence for a regulatory role of CD18 (beta 2-integrin) molecules; Ropke C et al.; Following a successful immune response against invading microorganisms, the majority of activated T cells is eliminated, while a minor fraction survives as memory T cells . A decline in T lymphocyte growth factors such as interleukin-2 (IL-2) appears to play a role in the elimination of previously activated T cells . Thus, removal of IL-2 from proliferating T cells not only induces growth arrest, but triggers a massive cell death due to apoptosis . While the apoptotic response involves a series of well-described events, it remains less clear how apoptosis is regulated following IL-2 withdrawal . Here, we provide evidence that CD18 molecules (beta 2-integrins) play a regulatory role in the apoptotic response following removal of IL-2 from previously activated, antigen specific CD4+ T cell lines . Thus, CD18 mAb inhibited the apoptotic response to IL-2 deprivation, whereas mAb against other adhesion molecules (CD28, CD29, CD49d, CD80, CD86) did not . Secondly, IL-2 withdrawal resulted in a retarded apoptotic response in LFA-1 (CD11a/CD18) negative T cells obtained from a leukocyte adhesion deficiency (LAD) patient, as compared to LFA-1 positive T cell lines . Thirdly, co-culture of LFA-1 positive- and negative-T cells at different ratios induced apoptotic responses that were higher than expected, had the two lymphocyte populations not been interacting and significantly higher than that seen in pure LFA-1 negative T cells . Supernatants from LFA-1 positive T cell cultures undergoing apoptosis did not induce an enhanced apoptotic responses in LFA-1 negative T cells, and, reversely, culture supernatants from LFA-1 negative T cells did not rescue LFA-1 positive cells from undergoing apoptosis . The apoptotic response was partly blocked by IL-15, a newly identified T cell growth factor . Taken together, these findings suggest that CD18 molecules (beta 2-integrins) play a regulatory role in the apoptotic response following cytokine withdrawal, and that the regulation is mediated, at least partly, through T-T cell interactions . Thus, apoptotic death following IL-2 deprivation appears to be under "social" control by surrounding T cells. J Dairy Sci, 1996 Aug, 79(8), 1476 - 86 Do ruminal bacteria exchange genetic material? Morrison M. This paper discusses the reasons and current evidence for gene transfer between ruminal bacteria and other bacteria in the environment, possible routes for genetic exchange, and candidate genes . Gene transfer between ruminal bacteria has been demonstrated in vitro; however, success has been only minimal in obtaining plasmids and other self-transmissible genetic material from ruminal bacteria . The application of molecular biology techniques with ruminal microorganisms should permit the opportunity for an in vivo assessment of gene transfer . Studies that could provide pertinent information for ruminal microbiologists and dairy nutritionists are outlined. Int J Food Microbiol, 1996 Aug, 31(1-3), 263 - 71 Characteristics of a multicomponent first-order model for thermal inactivation of microorganisms and enzymes; Fujikawa H et al.; There are several mathematical models that express different types of non-linear thermal inactivation of microorganisms and enzymes . Among the models the characteristics of a multicomponent first-order model were studied on a calculative simulation . For the initial period of inactivation the pattern of the model was predominantly affected by the kinetics of the component with the highest initial concentration . For longer periods of inactivation the pattern was predominantly affected by the kinetics of the component whose rate constant was the lowest . It was also found that the observation period affected the apparent pattern of the model . The estimation method of parameter values of the model from inactivation curves was then studied. Int J Food Microbiol, 1996 Aug, 31(1-3), 45 - 58 Fluorogenic and chromogenic enzyme substrates in culture media and identification tests; Manafi M; Rapid detection and identification of microorganisms is extremely important in many fields of applied and research microbiology . In general, fluorogenic and chromogenic substrates have proved to be a powerful tool, utilizing specific enzymatic activities of certain microorganisms, either in parallel with or instead of traditional methods . By incorporation of synthetic fluorogenic or chromogenic substrates into primary selective media, enumeration and detection can be performed directly on the isolation plate . The introduction of many of these media and identification tests has led to improved accuracy and faster detection of target organisms, often reducing the need for isolation of pure cultures and confirmatory tests. Eur Respir J, 1996 Aug, 9(8), 1729 - 35 Stomach as a source of colonization of the respiratory tract during mechanical ventilation: association with ventilator-associated pneumonia; Torres A et al.; The aetiopathogenesis of ventilator-associated pneumonia (VAP) requires abnormal oropharyngeal and gastric colonization and the further aspiration of their contents to the lower airways . VAP develops easily if aspiration or inoculation of microorganisms occur in patients with artificial airways, in whom mechanical, cellular and/or humoral defences are altered . Well-known risk factors for gastric colonization include: alterations in gastric juice secretion; alkalinization of gastric contents; administration of enteral nutrition; and the presence of bilirubin . However, the role of the colonized gastric reservoir in the development of VAP remains debatable . Evidence in favour of the role of the stomach in the development of VAP comes mainly from randomized, controlled trials of selective gut decontamination and stress ulcer prophylaxis in the intensive care unit (ICU), in which reducing the bacterial burden of the stomach decreases the incidence of nosocomial respiratory infections . However, at least three studies of flora have found an absence of stomach origin of pneumonia occurring during mechanical ventilation . Prophylactic measures suggested to prevent VAP in relation to the gastric reservoir include: treatment for stress ulcers with sucralfate; prevention of duodenal reflux with metoclopramide; reduction of gastric burden and bacterial translocation by selective digestive decontamination; acidification of enteral feeding; and jejunal feeding . Gastro-oesophageal reflux can be prevented by using small bore nasogastric tubes and jejunal feeding . The aspiration of gastric contents can be reduced by positioning patients in a semirecumbent position, checking the patency of the tube cuff, and aspiration of subglottic secretions . The role of the stomach as a reservoir for microorganisms causing ventilator-associated pneumonia is still controversial but despite the debate, there is major evidence in the literature in favour of the gastric origin of part of these pulmonary infections. Proteins, 1996 Aug, 25(4), 456 - 72 Evolution of beta-amylase: patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms; Pujadas G et al.; Soybean and sweet potato beta-amylases are structured as alpha/beta barrels and the same kind of folding may account for all known beta-amylases . We provide a comprehensive analysis of both protein and DNA (coding region) sequences of beta-amylases . The aim of the study is to contribute to the knowledge of the evolutionary molecular relationships among all known beta-amylases . Our approach combines the identification of the putative eightfold structural core formed by beta-strands with a complete multi-alignment analysis of all known sequences . Comparing putative beta-amylase (alpha/beta)8 cores from plants and microorganisms, two differentiated versions of residues at the packing sites, and a unique set of eight identical residues at the C-terminal catalytical site are observed, indicating early evolutionary divergence and absence of localized three-dimensional evolution, respectively . A new analytical approach has been developed in order to work out conserved motifs for beta-amylases, mostly related with the enzyme activity . This approach appears useful as a new routine to find sets of motifs (each set being known as a fingerprint) in protein families . We demonstrate that the evolutionary mechanism for beta-amylases is a combination of parsimonious divergence at three distinguishable rates in relation to the functional signatures, the barrel scaffold, and alpha-helix-containing loops. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1996 Aug, 82(2), 218 - 24 Pathohistology of undecalcified primary teeth in vitamin D-resistant rickets: review and report of two cases; Hillmann G et al.; The basic dental defects in vitamin D-resistant rickets seem to be manifested in dentin . Enamel is usually reported to be normal . This histologic examination showed the penetration of microorganisms through the calcified structures of the enamel layer without visible caries . The microorganisms passed through the dentinoenamel junction and invaded dentin, which was characterized by calcospherites and large amounts of interglobular dentin . Furthermore, microorganisms could be detected in dentinal tubules, which were exposed to the oral cavity when enamel was removed . However, large areas of tertiary dentin extended between such tubules and the pulp . These light microscopic results suggest that clinical manifestations, such as, pulp recrosis and periapical lesions (without carious defects) may be caused by the penetration of microorganisms through microclefts of the enamel layer as well as pathologically altered enamel microstructures of affected teeth. Exp Appl Acarol, 1996 Aug, 20(8), 421 - 34 Wolbachia: intracellular manipulators of mite reproduction; Breeuwer JA et al.; Cytoplasmically transmitted Wolbachia (alpha-Proteobacteria) are a group of closely related intracellular microorganisms that alter reproduction in arthropods . They are found in a few isopods and are widespread in insects . Wolbachia are implicated as the cause of parthenogenesis in parasitic wasps, feminization in isopods and reproductive (cytoplasmic) incompatibility in many insects . Here we report on the widespread occurrence of Wolbachia in spider mites and predatory mites based on a PCR assay for a 730 bp fragment of the ftsZ gene with primers that are specific for Wolbachia . An additional PCR, using two primer pairs that amplify a 259 bp region of the ftsZ gene that are diagnostic for the two Wolbachia subdivisions A and B, showed that infected mites only carried type B and not type A Wolbachia . The fact that some species tested negative for Wolbachia does not mean that the entire species is uninfected . We found that natural populations of Tetranychus urticae are polymorphic for the infection . The possible effects of Wolbachia on mite reproduction and post-zygotic reproductive isolation are discussed. Appl Biochem Biotechnol, 1996 Aug, 60(2), 97 - 106 Determination of cyanide using a microbial sensor; Nakanishi K et al.; A microbial cyanide sensor was prepared, consisting of immobilized Saccharomyces cerevisiae and an oxygen electrode . When the electrode was inserted into a solution containing glucose, the respiration activity of the microorganisms increased . The change in the respiration activity is monitored with the oxygen electrode . When cyanide is added to the sample solution, the electron transport chain reaction of the respiration system in the mitochondria is inhibited, resulting in a decrease in respiration . The inhibition is caused by cyanide binding with respiration enzymes such as the cytochrome oxidase complex in the mitochondrial inner membrane . Therefore, the cyanide concentration can be measured from the change in the respiration rate . When the sensor was applied to a batch system at pH 8.0 and 30 degrees C, the cyanide calibration curve showed linearity in the concentration range between 0.3 microM and 150 microM CN-. New Horiz, 1996 Aug, 4(3), 333 - 7 A model of the transmission of antibiotic-resistant bacteria in the intensive care unit; Barza M; Antibiotic resistance is a growing problem, affecting microorganisms found both in hospitals and in the community . In most patients, resistant organisms arise by transmission of already resistant microorganisms from another person, rather than arising by mutation in the index patient . Antibiotic resistance genes are often borne on plasmids or transposons on which they may be spread rapidly to other organisms in the same species or in other species . Plasmids and transposons readily pick up genes for resistance to other antibiotics or nonantibiotic agents ("linked resistance") . Control of the spread of antibiotic resistance may require limitation of the usage of other agents with linked resistance as well as of the antibiotics of primary interest . A model is described for the analysis of the transmission of antibiotic-resistant enteric bacteria in the ICU . The model deals with the baseline level of antibiotic resistance in the "source" patient, the effect of antibiotics in augmenting the concentration of resistant organisms in that patient, the role of patient-to-patient contact, and factors which may influence the "colonizability" of the recipient patient . Possible measures to reduce the spread of antibiotic resistance are discussed . It is hoped that the model may serve to focus discussion on some key ingredients of the transmission cycle. Am J Ind Med, 1996 Aug, 30(2), 142 - 7 Industrial hygiene measurements in a new industry: the repulping and deinking of paper waste; Rix BA et al.; Six Danish paper recycling plants were included in an assessment of exposure to chemicals . A questionnaire on processes was completed, and in-plant industrial hygiene measurement data collected 1982-1994 were examined . The assessment of chemicals did not reveal a major use of possible carcinogens, but acrylamide may have been released in the work environment in one plant . A total of 197 hygiene measurements were recorded: 126 in the largest plant . Airborne concentrations of dust, microorganisms, and endotoxins varied widely between plants . High concentrations of dust were recorded in the paper machine area in one plant and in the repulping unit in another plant . In general, endotoxin levels were low, but endotoxin levels were increased in one plant when reuse of process water was intensified . Changes in procedures should be assessed by industrial hygiene measurements. J Antibiot (Tokyo), 1996 Aug, 49(8), 752 - 7 Heliquinomycin, a new inhibitor of DNA helicase, produced by Streptomyces sp . MJ929-SF2 I . Taxonomy, production, isolation, physico-chemical properties and biological activities; Chino M et al.; Heliquinomycin was isolated as a part of a program designed to find inhibitors of DNA helicase from microbial sources . It was purified from the culture broth of Streptomyces sp . MJ929-SF2 by solvent extraction and serial chromatographies of centrifugal partition chromatography, Sephadex LH-20 and Capcell Pak C18 (HPLC) . The isolated red powder was analyzed to have the molecular formula of C33H30O17 . It inhibited partially purified DNA helicase from HeLa cell in a non-competitive manner with the inhibition constant (Ki) of 6.8 mM . Heliquinomycin exhibited biological activity against microorganisms including MRSA, and cultured cell lines. Biochem Mol Med, 1996 Aug, 58(2), 151 - 5 Detection of Actinomyces species using nonradioactive riboprobes coupled with polymerase chain reaction; Kiyama M et al.; We have been focusing our attention on the detection and identification of oral bacteria which are frequently associated with periodontal disease . In previous studies, Actinomyces species-specific riboprobes were generated and used to identify this microorganism . However, problems lie in the low sensitivity of this method . We have developed a novel system for the detection of Actinomyces species using nonradioactive riboprobes coupled with polymerase chain reaction (PCR) in this study . This system employs two procedures; initially, DNA fragments specific for the target microorganism are amplified by PCR, and these specific fragments are further hybridized with nonradioactive riboprobes . PCR analysis using chromosomal DNA isolated from Actinomyces species including laboratory strains, clinical isolates, and Actinomyces naeslundii (ATCC 12104) indicated the presence of the predicted common 756-bp fragment, a portion of the sialidase gene . These amplified DNA fragments were effectively visualized by hybridization with the digoxigenin-labeled riboprobes corresponding to the internal region of the amplified sialidase gene . With this system, approximately three orders of magnitude less chromosomal DNA was sufficient for the detection of specific microorganisms compared to the conventional riboprobe systems. Insect Mol Biol, 1996 Aug, 5(3), 217 - 21 Molecular identification of a Wolbachia endosymbiont in a Tetranychus urticae strain (Acari: Tetranychidae); Tsagkarakou A et al.; Wolbachia, a maternally inherited bacterium, is involved in alterations of arthropod sexuality . Reproductive incompatibilities are often observed in miles, but the existence of this microorganism in their cytoplasm has not yet been demonstrated . We identified the presence of Wolbachia in a strain of the spider mite Tetranychus urticae based on the amplification and sequencing of part of the 16S rDNA and ftsZ genes . In order to establish the phylogenetic relationships between Wolbachia found in T . urticae and in other arthropods, we aligned the resulting sequences with already published ones . For both 16S and ftsZ genes the Wolbachia carried by T . urticae clustered together with Wolbachia found in other arthropods. Can J Microbiol, 1996 Aug, 42(8), 875 - 9 A novel fluorochrome for the microscopic observation of microbial morphology in wet mounts; Chan EC et al.; A family of novel nontoxic fluorochromes, including trans-4-(p-N,N-dimethylaminostyryl)-N-butoxycarbonyl-methylpyridin ium bromide and other dimethylaminostyrylpyridinium salts, has been used for the examination of microorganisms in the living state . Equipment required is similar to that for immunofluorescence, but the technique does not necessitate the utilization of specific antibodies . Procaryotic vegetative cells and endospores were readily visualized by their fluorescence with no observable quenching . Other bacteria observed included capsule-forming species, acid-fast mycobacteria, and spirochetes . In addition, the technique is also applicable to the examination of eucaryotic microorganisms . The technique as described is simple and convenient, and serves as an alternate means for the microscopic study of viable microorganisms. Eur J Biochem, 1996 Aug 1, 239(3), 835 - 41 cDNA cloning of mouse nebulin . Evidence that the nebulin-coding sequence is highly conserved among vertebrates; Zhang JQ et al.; Nebulin is a family of giant myofibrillar proteins with molecular masses ranging over 700-900 kDa . Using a human nebulin cDNA probe, we isolated three nebulin cDNA clones from a mouse skeletal muscle cDNA library . These three clones, labeled 8c . 7a and 4b . carry inserts of 2.0, 3.0 and 3.5 kb, respectively . In Northern blots, each insert detected the same approximately = 25 kb message from skeletal muscle as the human nebulin probe, while detecting no messages from cardiac muscle . Sequence data in combination with reverse-transcriptase PCR indicates that clones 7a and 8c overlap to form 4076 bp contiguous sequence . Alignment with the published full-length human nebulin sequence indicates that clone 4b overlaps with clone 7a over 1596 bp . However, after the first 798-bp overlap, the sequence of these two mouse nebulin clones diverge, suggesting that they derive from distinct transcripts encoding isoforms of mouse nebulin . The mouse nebulin clones encode a series of = 245-residue super repeats, each of which can be subdivided into seven = 35-residue, weakly repeating modules centered around a conserved tyrosine residue, consistent with the human nebulin sequence . The mouse nebulin clones align along the central third of the full-length human sequence, corresponding to super repeats 8-16 of the 22 super repeats found in human nebulin . The translated sequence is greater than 90% identical to the human sequence, with the exception of a 200-amino-acid region at the C-terminus of clone 4b, which is less than 60% identical . In genomic Southern blots, a mouse nebulin probe detected a homologous sequence in a wide variety of vertebrate species under stringent conditions . However, no significant hybridization was observed to genomic DNA from invertebrates and microorganisms, even under very low stringency . The sequence and Southern-blot data suggest that the nebulin sequence is highly conserved among vertebrate species. Microbiology, 1996 Aug, 142 ( Pt 8), 1927 - 35 Growth rate control of protein and nucleic acid content in Streptomyces coelicolor A3(2) and Escherichia coli B/r; Shahab N et al.; Escherichia coli possesses regulatory mechanisms that coordinate cell growth with the synthesis of essential macromolecules (protein, RNA and DNA) . While fundamental differences have been identified in the growth habit and chromosome structure of E . coli and Streptomyces, little is known about these regulatory mechanisms in filamentous bacteria . This paper reports on the relationship between the macromolecule content of S . coelicolor A3(2) and its specific growth rate . The protein, RNA and DNA contents (g per 100 g biomass) of S . coelicolor A3(2) grown in steady-state continuous culture over a range of specific growth rates (0.025-0.3 h-1) were 31-45, 10-22 and 3.5-4.5% (w/w), respectively . This composition is qualitatively similar to that of other microorganisms . Changes in the macromolecular content of S . coelicolor A3(2) and E . coli B/r with specific growth rate appear to be essentially similar . However, the data indicate that the RNA content of S . coelicolor A3(2), grown under the conditions used, exceeds that of E . coli grown at the same specific growth rate . The data also suggest that overlapping rounds of replication are not a feature of DNA synthesis in S . coelicolor A3(2) . This may be a function of the organism's low maximum specific growth rate . Alternatively, it may be a consequence of regulatory mechanisms which act to inhibit the initiation of DNA synthesis in a linear chromosome which is already undergoing replication. Toxicol Lett, 1996 Aug, 86(2-3), 79 - 83 Chemicals and proteins as allergens and adjuvants; Kapsenberg ML; Small molecular weight chemicals may irritate tissues via the induction of the production of various proinflammatory and chemotactic molecules . The structure of these irritants is heterogenous, as is the pattern of their effects . Chemicals are potentially allergenic (i.e . haptens) when they are able to bind proteins such as immune response molecules . Sensitization will occur when these haptens additionally induce irritation resulting from an intrinsic adjuvant's activity of the chemical . In most cases haptens induce the activation of hapten-specific T cells with a type 1 cytokine profile mediating delayed hypersensitivity . A limited number of haptens induce the production of type 2 cytokines in T cells and, consequently, allergic reactions after inhalation . Similarly, inhaled proteins become allergenic when they activate protein allergen-specific T cells producing type 2 cytokines . In many individuals this cytokine profile is associated with atopy . It must be expected, however, that a type 2 cytokine profile can also be inflicted by the action of various adjuvants types, such as biologically active small molecular weight chemicals and proteins (i.e . enzymes) and microorganisms, thereby promoting allergic reactions. Ann N Y Acad Sci, 1996 Jul 23, 791, 314 - 7 Preharvest food safety; Childers AB et al.; Preharvest food safety is essential for the protection of our food supply . The production and transport of livestock and poultry play an integral part in the safety of these food products . The goals of this safety assurance include freedom from pathogenic microorganisms, disease, and parasites, and from potentially harmful residues and physical hazards . Its functions should be based on hazard analysis and critical control points from producer to slaughter plant with emphasis on prevention of identifiable hazards rather than on removal of contaminated products . The production goal is to minimize infection and insure freedom from potentially harmful residues and physical hazards . The marketing goal is control of exposure to pathogens and stress . Both groups should have functional hazard analysis and critical control points management programs which include personnel training and certification of producers . These programs must cover production procedures, chemical usage, feeding, treatment practices, drug usage, assembly and transportation, and animal identification . Plans must use risk assessment principles, and the procedures must be defined . Other elements would include preslaughter certification, environmental protection, control of chemical hazards, live-animal drug-testing procedures, and identification of physical hazards. Ann N Y Acad Sci, 1996 Jul 23, 791, 136 - 47 Reactive oxygen and nitrogen intermediates and products from polyamine degradation are Babesiacidal in vitro; Johnson WC et al.; Products released from activated macrophages have been demonstrated to have microbicidal activity against a variety of microorganisms . Reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) have been shown to affect the induction of degenerate (crisis) forms of Plasmodium spp . Polyamines are degraded into acrolein which has also been shown to be toxic to Plasmodium spp . We have investigated the possibility that these products act similarly with Babesia bovis . Crisis forms of B . bovis developed in erythrocyte cultures after the introduction of supernatants containing ROI, RNI, and acrolein . Xanthine degradation by xanthine oxidase leads to the formation of superoxide anion, hydrogen peroxide, and hydroxyl radicals . The degradation in the presence of B . bovis was toxic to the parasite . The toxicity was partially reversed by the addition of the ROI scavenger catalase . However, H2O2 added directly had little effect, suggesting a role for the other ROI products . Spermine degradation by polyamine oxidase and direct addition of acrolein was toxic in a dose-dependent manner . Finally, spontaneous generation of nitric oxide from sodium nitroprusside or S-nitroso-N-acetyl-penicillamine was also toxic in a dose-dependent manner . These data lead us to suggest a role for activated macrophages in the primary immune response against B . bovis. Proc Natl Acad Sci U S A, 1996 Jul 23, 93(15), 7979 - 84 16S rRNA genes reveal stratified open ocean bacterioplankton populations related to the Green Non-Sulfur bacteria; Giovannoni SJ et al.; Microorganisms play an important role in the biogeochemistry of the ocean surface layer, but spatial and temporal structures in the distributions of specific bacterioplankton species are largely unexplored, with the exceptions of those organisms that can be detected by either autofluorescence or culture methods . The use of rRNA genes as genetic markers provides a tool by which patterns in the growth, distribution, and activity of abundant bacterioplankton species can be studied regardless of the ease with which they can be cultured . Here we report an unusual cluster of related 16S rRNA genes (SAR202, SAR263, SAR279, SAR287, SAR293, SAR307) cloned from seawater collected at 250 m in the Sargasso Sea in August 1991, when the water column was highly stratified and the deep chlorophyll maximum was located at a depth of 120 m . Phylogenetic analysis and an unusual 15-bp deletion confirmed that the genes were related to the Green Non-Sulfur phylum of the domain Bacteria . This is the first evidence that representatives of this phylum occur in the open ocean . Oligonucleotide probes were used to examine the distribution of the SAR202 gene cluster in vertical profiles (0-250 m) from the Atlantic and Pacific Oceans, and in discrete (monthly) time series (O and 200 m) (over 30 consecutive months in the Western Sargasso Sea . The data provide robust statistical support for the conclusion that the SAR202 gene cluster is proportionately most abundant at the lower boundary of the deep chlorophyll maximum (P = 2.33 x 10(-5)) . These results suggest that previously unsuspected stratification of microbial populations may be a significant factor in the ecology of the ocean surface layer. Proc Natl Acad Sci U S A, 1996 Jul 23, 93(15), 7944 - 9 Induction of mucosal immune responses against a heterologous antigen fused to filamentous hemagglutinin after intranasal immunization with recombinant Bordetella pertussis; Renauld-Mongenie G et al.; Live vaccine vectors are usually very effective and generally elicit immune responses of higher magnitude and longer duration than nonliving vectors . Consequently, much attention has been turned to the engineering of oral pathogens for the delivery of foreign antigens to the gut-associated lymphoid tissues . However, no bacterial vector has yet been designed to specifically take advantage of the nasal route of mucosal vaccination . Herein we describe a genetic system for the expression of heterologous antigens fused to the filamentous hemagglutinin (FHA) in Bordetella pertussis . The Schistosoma mansoni glutathione S-transferase (Sm28GST) fused to FHA was detected at the cell surface and in the culture supernatants of recombinant B . pertussis . The mouse colonization capacity and autoagglutination of the recombinant microorganism were indistinguishable from those of the wild-type strain . In addition, and in contrast to the wild-type strain, a single intranasal administration of the recombinant strain induced both IgA and IgG antibodies against Sm28GST and against FHA in the bronchoalveolar lavage fluids . No anti-Sm28GST antibodies were detected in the serum, strongly suggesting that the observed immune response was of mucosal origin . This demonstrates, to our knowledge, for the first time that recombinant respiratory pathogens can induce mucosal immune responses against heterologous antigens, and this may constitute a first step toward the development of combined live vaccines administrable via the respiratory route. Front Biosci, 1996 Jul 01, 1, d72 - 90 Interactions between the components of the human NADPH oxidase: a review about the intrigues in the phox family; Leusen JH et al.; When microorganisms invade the body, they encounter a large asssortment of defense mechanisms . Among these, phagocytes play an important role in the process of killing pathogens . This event is mediated by two important processes, viz . activation of the NADPH oxidase enzyme, which leads to the production of toxic oxygen metabolites, and fusion of intracellular granules with the phagosome (the vesicle that contains the ingested micro-organisms), which causes release of the toxic granule contents into this vesicle . The human NADPH oxidase is a very complex enzyme, in two ways: 1 . it exists of at least 6 components: cytochrome b558 (a heterodimer comprised of gp91-phox and p22-phox), p47-phox, p67-phox, p40-phox, rac and Rap1A, and 2 . there are multiple signal transduction pathways leading to activation of the NADPH oxidase . The most likely reason for this complexity is the toxicity of the oxygen radicals produced by the active NADPH oxidase; these compounds are not only harmful to the invading pathogens, but also to the surrounding tissues . This latter effect is enforced by the activation of metalloproteases released by neutrophils and by oxidation of protease inhibitors by oxygen metabolites . Therefore, an improper activation of the NADPH oxidase must be prevented at all costs and, when the infection has been cleared, a rapid deactivation mechanism is imperative . In this review, the interaction between the different components of the NADPH oxidase and the activation of these proteins will be discussed. Mycoses, 1996 Jul-Aug, 39(7-8), 279 - 82 Partial characterization of proteolytic enzymes of Microsporum canis and Microsporum cookei; Simpanya MF et al.; Characterization by proteinase inhibitors of the enzymes produced by Microsporum spp . revealed that Microsporum canis and Microsporum cookei produce serine proteinase(s), but only M . canis expresses aspartic and cysteine proteinases and probably a metalloproteinase . Both M . canis and M . cookei expressed metalloelastinolytic proteinases . All the proteinase types have been implicated in the pathogenicity of a wide range of microorganisms. Rev Environ Health, 1996 Jul-Sep, 11(3), 149 - 65 Recombinant DNA technology: a 20-year occupational health retrospective; Cohen R et al.; During the past 20 years of recombinant DNA research and its commercial applications, neither unique occupational-health risks nor adverse effects from accidental occupational recombinant microorganisms has been reported . Such injuries as acid splashes, CNS-depressant effects from over-exposure to solvents, and infections may occur in all types of chemistry and microbiology laboratories . Because of the relative inexperience with the emerging technology of gene therapy, however, including possible vector replication or recombination, further vigilance in monitoring the safety of their applications is required. Todays Surg Nurse, 1996 Jul-Aug, 18(4), 27 - 9 Choosing the best protective gloves; Rosenblatt E; Gloves should provide two-way protection from the transmission of microorganisms between worker and patient . Until recently, glove manufacturers paid little attention to barrier properties . Because the operating room is a high-risk area, surgical nurses must be especially careful about gloving practices. Appl Microbiol Biotechnol, 1996 Jul, 45(6), 723 - 9 Safe biotechnology . 7 . Classification of microorganisms on the basis of hazard . Working Party "Safety in Biotechnology" of the European Federation Biotechnology; Lelieveld HL et al.; The current systems for classifying human pathogens on the basis of hazard are well developed and their basic criteria are in general agreement one with another . Of more importance, the safety practices based on these classifications have generally been successful . They have enabled extensive research activities, medical practice and industrial production to be conducted on an ever-increasing scale, involving dangerous microorganisms (e.g . in vaccine production and treatment of infected patients) with a very low incidence of adverse effects on the workers involved and the general public . Although the EU has adopted a harmonised list of agents in groups 1-4 there is as yet no complete agreement among member states and individual microbiologists . The purpose of this paper is to present a historical survey and to discuss the current processes for identifying and classifying the hazards posed by the use of microorganisms in research and technology . This is essential in the design of appropriate methods of counteracting potential risks. Genetika, 1996 Jul, 32(7), 922 - 6 {Mutator genes from Saccharomyces cerevisiae . Repair of artificial heteroduplexes in him and hsm mutants}; Gracheva LM et al.; During recent years, genes controlling mutation in higher eukaryotes have been found to be involved actively in carcinoma regeneration in cells . In this respect, studying the genetic control of mutagenesis becomes a key direction of research into mechanisms responsible for cancer generation . The results of studying interaction of mutations in the HSM3 and HSM6 genes, controlling spontaneous and induced mutagenesis in yeasts, and mutations impairing three known pathways of DNA damage repair in this microorganism, are described in this work . It was shown that mutation rev3 completely blocks UV-induced mutagenesis in all mutants studied . On the other hand, mutation rad2 synergistically interacts with mutations him1, hsm1, hsm3, hsm6, and hsm2, thus enhancing the frequency of UV-induced mutagenesis in double mutants multiple times . Mutations him2 and him3 manifested epistatic interaction with mutation rad2 . With mutation rad54, the interaction was epistatic for mutations him1 and hsm2 and was additive for mutations hsm1, him2, and him3 . On the basis of the data obtained, we developed a scheme for the appearance of mismatch bases in the process of repair of UV-induced DNA damage. Z Rheumatol, 1996 Jul-Aug, 55(4), 249 - 55 {Ankylosing spondylitis and urogenital infection: diagnosis of urologic infection and correlation with rheumatologic findings}; Lange U et al.; We examined 134 male patients with confirmed ankylosing spondylitis . The study protocol included a medical-rheumatological examination and thorough exploration for infections of the urinogential tract . An urethroadnexitis was found in 37 of 134 patients (27.6%): Two patients suffered from balanitis, 17 patients from urethritis, 18 patients from prostatitis, and two patients from epididymitis . Only four patients gave a history of urethritis and eight patients of prostatitis . The microorganisms isolated most frequently from patients with urogenital infection were Chlamydia trachomatis and, in few cases, Ureaplasma urealyticum . By comparing the urethroadnexitis group and the non-infected group with regard to other clinical parameters, we found a significantly increased C-reactive protein in the infected group . Other clinical parameters like involvement of the free spinal column, inflammatory involvement of the joints, and HLA-B27 correlation did not differ significantly. Lijec Vjesn, 1996 Jul-Aug, 118(7-8), 171 - 7 {Inhibition of bacterial adherence--possibilities of prevention and therapy}; Vranes J; The majority of bacterial infections begin with the adherence of pathogenic bacteria to the surfaces of epithelial cells . Microorganisms adhere to cells in a highly selective manner so that sneezing, coughing, peristalsis, and fluid flow cannot remove them . Even though the study of bacterial adherence gives a new insight: to the pathogenesis of infectious diseases, the question that always arises is whether infection can be prevented or treated by interfering with this first step in the pathogenesis of infectious diseases . Adherence may be inhibited by substances that block the interaction between the bacterial adhesin and the target cell receptor . These include the soluble form of receptor, antibodies against the receptor or against the adhesin, and antibiotics which impair bacterial adherence . In this review all three possibilities are considered. An Med Interna, 1996 Jul, 13(7), 347 - 52 {Superantigens: concept and applications in the pathogenesis and treatment of infectious and autoimmune diseases}; Quiros E et al.; The aim of this study was to review the characteristics of conventional antigens and the way they work, as well as to remark their differences with superantigens . They bind exclusively to the lymphocytic TCR V beta portion, are not processed by macrophages, are related to dependent HLA but not restrained HLA and are able to stimulate a hugh number of lymphocytes, leading them to destruction . Different microorganisms (toxins from S . aureus, S . pyogenes, M . arthritidis, etc . produce a high number of superantigens, which have been associated with infectious diseases, especially by HIV . They have also been related to immunological disorders such as multiple sclerosis, diabetes mellitus, Siogren's syndrome, sarcoidosis, etc . In conclusion, these new molecules will enable us to review the etiology of many diseases and, the most relevant from a clinical point of view, its treatment. Acta Otorrinolaringol Esp, 1996 Jul-Aug, 47(4), 314 - 6 {Acute otitis media caused by Nocardia asteroides}; Salvo Gonzalo S et al.; Nocardia asteroides is a bacteria that is distributed widely in nature and produces infection in most organs . Pulmonary nocardiosis is the most common form of clinical presentation . Few references exist regarding ear disease produced by this microorganism . A case of acute otitis media caused by N . asteroides produced subtotal tympanic perforation in a 45-year-old immunocompetent patient . The causal diagnosis was made by pure culture growth, repeated isolation and visualization of the microorganism in Gram-stained specimens of ear exudate . The strain was resistant to cotrimoxazole, but the patient was treated successfully with ciprofloxacin. J Endod, 1996 Jul, 22(7), 352 - 5 Effect of protoporphyrin IX limitation on porphyromonas gingivalis; Schifferle RE et al.; Porphyromonas gingivalis has been shown to require hemin or hemoglobin for in vitro growth . We have previously shown that protoporphyrin IX and inorganic iron can replace the hemin requirement, suggesting that the hemin requirement of this microorganism is actually a porphyrin requirement . We examined the effect of protoporphyrin IX limitation to P . gingivalis strain A7A1-28 in the presence of sufficient iron on growth characteristics, proteolytic enzyme production, virulence in a mouse abscess model, and expression of membrane proteins . Bacterial cells were grown in medium varying between 0 to 5 microM reduced growth by at least 50% . Protoporphyrin IX availability did not affect proteolytic enzyme production or virulence in a mouse abscess model . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of membrane preparations demonstrated that protoporphyrin IX limitation induced the expression of new proteins at 42, 34, 30, 29, and 18 kDa and suppressed the production of proteins at 47, 27, 17, and 15 kDa . These studies suggest that in vivo protoporphyrin availability may modulate membrane protein expression and in turn affect host immune responses against P . gingivalis. Rev Invest Clin, 1996 Jul-Aug, 48(4), 261 - 5 Helicobacter pylori and lymphoid follicles in primary gastric MALT-lymphoma in Mexico; Herrera-Goepfert R et al.; We reviewed our cases of gastric MALT-lymphomas over a 12-year period at a national oncological referral center, the Instituto Nacional de Cancerologia in Mexico City, looking for morphological evidence of Helicobacter pylori infection near the primary neoplasia . H pylori as well as lymphoid follicles and chronic active gastritis were carefully searched for in the adjacent mucosa . There were 23 (85%) low-grade and four (15%) high-grade MALT-lymphomas . H pylori microorganisms were found adjacent to the neoplasia in 23 cases (85%; CI 95% = 72-99%) but the lymphoid follicles were seen in 15 of 23 (65%; CI = 56-74%) . Chronic active gastritis was present in 25 cases (93%; Cl = 90-95%) . There was a close association between H pylori and gastric MALT-lymphoma . Lymphoid follicles were a reliable indicator of infection and the claimed pathophysiological substrate for MALT-lymphoma . We conclude that patients in whom gastric lymphoid follicles are detected, must remain under clinical follow-up since H pylori is a plausible promoter of neoplastic transformation. Mol Microbiol, 1996 Jul, 21(2), 293 - 300 A stringently controlled expression system for analysing lateral gene transfer between bacteria; Jaenecke S et al.; The lateral transfer of genetic information among microorganisms is a major force driving the outstanding adaptability of microbial communities to environmental changes . Until now little information has been obtained on gene transfer in natural ecosystems . We present here a genetic circuit for detecting and quantifying horizontal gene transfer from a defined donor microorganism to recipient organisms in the absence of selection for a recipient-specific phenotype . The system consists of an engineered lacZ (encoding beta-galactosidase) reporter gene whose expression is controlled by a synthetic regulatory element based on a fusion between the Pr promoter-operator from lambda bacteriophage and the 5' non-coding leader region of the inp gene encoding the IS 10 transposase function . Expression of this reporter cassette in the recombinant microorganism is completely shut down by two chromosomally encoded trans-acting repressors working at the level of transcription (the Cl-EK117 protein from the lambda phage), and at the level of translation (the antisense RNA-OUT of the IS 10 element) . When the reporter element is transferred to a different host by any mechanism, it escapes repression and becomes expressed . The system was validated with Pseudo-monas putida, and conjugational transfer frequencies of the reporter element as low as 10(-6) were detected . The modular design and broad host range of the genetic circuit, in combination with biomarkers which permit real-time in situ detection, will facilitate the monitor-ing of gene flow in a non-disruptive manner within the environment. Int J Food Microbiol, 1996 Jul, 30(3), 315 - 24 Genetically modified starter and protective cultures; Geisen R et al.; Modern approaches towards starter and protective culture improvement rely on advances in molecular biology . For most microorganisms used for food production, gene technological methods have been well developed . By recombinant DNA technology, 'tailor-made' starter and protective cultures may be constructed so as to combine technically desirable features . A single strain which normally would fail to accomplish a given 'task' may now be improved so as to meet a set of requirements necessary for a specific production or preservation process (e.g . wholesomeness, no off-flavour production, overproduction of bacteriocins or particular enzymes) . In addition, undesirable properties (e.g . mycotoxin or antibiotic production by cheese moulds) may be eliminated by techniques such as 'gene disruption'. Antonie Van Leeuwenhoek, 1996 Jul, 70(1), 1 - 10 DNA in soil: adsorption, genetic transformation, molecular evolution and genetic microchip; Trevors JT; This review examines interactions between DNA and soil with an emphasis on the persistence and stability of DNA in soil . The role of DNA in genetic transformation in soil microorganisms will also be discussed . In addition, a postulated mechanism for stabilization and elongation/assembly of primitive genetic material and the role of soil particles, salt concentrations, temperature cycling and crystal formation is examined. Dent Clin North Am, 1996 Jul, 40(3), 611 - 47 Pharmacologic management of the patient with disorders of the cardiovascular system . Infective endocarditis; Cowper TR; IE, although an infrequent event, remains a serious and frequently lethal complication in patients at risk . Oral microorganisms undoubtedly play a significant role in the development of IE in such patients . For example, in a retrospective review of prosthetic cardiac valve candidates (156) at the Cleveland Clinic Foundation, 15% were found to have at least one abscessed tooth, whereas approximately 17% were found to have severe (class IV) periodontal disease . Cardiac defects in conjunction with bacteremias from such dental pathoses clearly elevate the risk, although a small but increasing number of noncardiac conditions and behavioral patterns seem also to be able to induce susceptibility . Whether dental or other medical procedures are truly direct inducers of IE, however, remains to be proven and in all probability are only minor contributors overall . Despite its ubiquitous use, antibiotic prophylaxis has not been proven in human clinical trials, and its underlying rationale is arbitrary and questionable at best; nevertheless, its efficacy in animal models has led to the current human protocols . A more profitable strategy, and certainly an adjunctive one, should be to direct one's effort at eliminating oral pathology and educating and motivating patients at risk toward meticulous oral hygiene--an exhortation published many years before the advent of antibiotics and still undoubtedly the best recommendation today. Vet Microbiol, 1996 Jul, 51(1-2), 179 - 85 Improved method for preparation of samples for the polymerase chain reaction for detection of Coxiella burnetii in milk using immunomagnetic separation; Muramatsu Y et al.; Immunomagnetic separation (IMS) improved the detection of Coxiella burnetii in cow's milk by the polymerase chain reaction (PCR) . IMS represents a novel approach to the isolation of microorganism from milk . The combination of IMS and PCR analysis has an adequate sensitivity for detection of C . burnetii. Vet Microbiol, 1996 Jul, 51(1-2), 85 - 93 The sensitizing effect of a Brucella abortus antigen in cattle after repeated intradermal inoculations; Bercovich Z et al.; An antigen prepared from a mucoid strain of B . abortus was repeatedly injected intradermally into cattle to determine whether it sensitizes cattle so that they test false positive with the skin delayed-type hypersensitivity (SDTH) test . Cattle (n = 14) that were experimentally inoculated . with microorganisms that serologically cross-react with B . abortus, and uninfected cattle (n = 15) were tested with the antigen 2 to 5 times over a period of 16 to 17 weeks . An increase in skinfold thickness of > or = 2.0 mm on the injection site was considered a reaction elicited by the antigen . The sera from the cattle were tested with the serum agglutination test, complement fixation test, and an enzyme-linked immunosorbent assay for antibodies against B . abortus . Results showed that none of the animals had an increase in skinfold thickness of > or = 2.0 mm on the injection site of the antigen, which is considered a positive reaction . However, cattle experimentally inoculated with microorganisms other than B . abortus tested seropositive for brucellosis after one SDHT test only . We conclude that the B . abortus antigen inoculated intradermally does not sensitize cattle after repeated inculations, and therefore does not interfere with the subsequent use of the SDTH test in the diagnosis of brucellosis. Adv Ren Replace Ther, 1996 Jul, 3(3), 232 - 6 Peritonitis in peritoneal dialysis patients: an overview; Tzamaloukas AH; The incidence of peritonitis in peritoneal dialysis (PD) patients has decreased as a result of improvements in PD technology . Nevertheless, peritonitis remains a major problem in PD, with a substantial percent of patients developing persistent or relapsing infections . Current treatment guidelines emphasize the use of intraperitoneal antibiotics and once-a-day administration of aminoglycosides and provide indications for removal of the peritoneal catheter . Further clinical studies testing these guidelines are needed . In addition, guidelines for patients on PD treatment modalities other than standard continuous ambulatory peritoneal dialysis (CAPD) need to be developed . Peritonitis may lead to extensive adhesion formation, peritoneal fibrosis of varying severity, permanent loss of peritoneal ultrafiltration, severe malnutrition, sepsis, and death . Special forms of peritonitis requiring great care and further study include those caused by fungi, mycobacteria, and multiple microorganisms, and those developing in HIV-positive PD patients. Clin Infect Dis, 1996 Jul, 23(1), 101 - 6 Detection of a vacuolating cytotoxin in stools from children with diarrhea; Luzzi I et al.; A cytotoxin inducing vacuolation in HEp-2 cells was detected in 19 (3.1%) of 618 stool specimens from children with diarrhea but in none of 135 from control children . Common enteric pathogens were found in only two (10.5%) of the 19 cytotoxin-positive stool specimens . The vacuoles induced by stool filtrates resembled those induced by the vacuolating toxin (VacA) of Helicobacter pylori . The vacuolating toxin was heat-labile and protease-sensitive, and it had an apparent molecular weight of > 100,000 but was not neutralized by an antiserum to H . pylori VacA . Although proper prospective case-control studies are needed to definitely assess the etiologic association between the new vacuolating cytotoxin and diarrhea, the present study suggests that microorganisms of the gastrointestinal tract produce a Helicobacter-like vacuolating toxin and may be responsible for cases of childhood diarrhea whose etiology is currently considered unknown. J Prosthet Dent, 1996 Jul, 76(1), 8 - 14 Dimensional stability of seven elastomeric impression materials immersed in disinfectants; Thouati A et al.; Dental impressions can increase the transmission of microorganisms and infections . The purpose of this study was to assess the influence of three disinfectant solutions on the dimensional accuracy of seven elastomeric impression materials . Impressions of a test block were either left untreated (controls) or treated by immersion in a disinfectant solution . Measurements were taken on die stone replicas of the impressions . Comparisons were made between (1) the measurements for the variations in the nontreated impressions and those for the treated impressions and (2) measurements for the treated impressions and the test block . Results indicated that the aminoamphoteric agent or glutaraldehyde derivative-based solutions created little change in relation to the initial dimensional accuracy of the impression products . However, the sodium hypochlorite solution often leads to expansion by comparison with controls . By comparison to the test block, this expansion then makes it possible in most cases to obtain better dimensional accuracy than initially . Within the limits of this study this expansion could lead to an improvement in clinical fixed prosthodontic procedures. Nihon Kyobu Shikkan Gakkai Zasshi, 1996 Jul, 34(7), 804 - 9 {Allergic bronchopulmonary mycosis caused by Schizophyllum commune}; Tomita K et al.; In December 1989, a 72-year-old woman was hospitalized with atelectasis in the left lower lobe . The atelectasis resolved after bronchoscopic removal of impacted mucous plugs . Histopathological examination showed pulmonary mycosis . Microscopy suggested that a species of Aspergillus was responsible, but no definite diagnosis was made . After treatment with flucytosine and nebulized amphotericin, the patient's condition improved and she was discharged . In the middle of August 1994, she visited a local hospital complaining of fatigue . Eosinophilia (22%) was detected, and a few days later she visited that hospital again due to sudden dyspnea . A chest X-ray examination showed an abnormal shadow, and she was referred to our hospital . Atelectasis was seen in the left upper lobe . This finding, together with eosinophilia, suggested recurrence of pulmonary mycosis, and therefore bronchoscopy was performed . White mucous plugs obstructing the left upper lobe were observed and were bronchoscopically removed . Microscopical examination of the mucous plugs showed marked eosinophil infiltration and hyphae . Cultures of specimens obtained during bronchoscopy showed Schizophyllum commune, and allergic bronchopulmonary mycosis due to this microorganism was diagnosed . Identification of this microorganism as a cause of deep-seated pulmonary mycosis is very rare. Neurochem Int, 1996 Jul, 29(1), 83 - 7 Inhibition of cytokine-inducible nitric oxide synthase in rat microglia and murine macrophages by methyl-2,5-dihydroxycinnamate; Zielasek J et al.; Microglial cells are resident macrophages in the central nervous system (CNS) which serve specific functions in the defence of the CNS against microorganisms, the removal of tissue debris in neurodegenerative diseases or during normal development, and in autoimmune inflammatory disorders of the brain . Microglia express a cytokine-inducible isoform of nitric oxide synthase, which leads to the production of nitric oxide (NO) . Since NO is highly toxic to neurons and oligodendrocytes, we were interested to test down-regulating neuropeptides and second messenger de-activators in order to identify novel antagonists of cytokine-induced NO production . We found that only the tyrosine kinase inhibitor methyl-2,5-dihydroxycinnamate suppressed cytokine-induced NO production by rat microglial cells and murine macrophages, while a range of other tyrosine kinase inhibitors, neuropeptides and growth factors was ineffective . Since NO production may play a role in the pathogenesis of experimental neuro-immunological disorders like experimental autoimmune encephalomyelitis and experimental autoimmune neuritis, our findings suggest a possible therapeutic role for tyrosine kinase inhibitors. Kansenshogaku Zasshi, 1996 Jul, 70(7), 710 - 6 {Development of a detection system for Helicobacter pylori DNA in gastric juice}; Tamatsukuri S et al.; A rapid and sensitive PCR-based microwell plate assay (PCR-MWP) system to detect the 16 S ribosome RNA gene of Helicobacter pylori was developed . Analytical sensitivity, evaluated with purified recombinant plasmid DNA and genomic DNA of H . pylori, was one copy of DNA per PCR . Specificity was validated with a panel of DNA from 75 kinds of microorganisms including Helicobacter showed weak positives, when 1 pg of DNA was input . Other microorganisms gave negative signals even when 100 pg of DNA was used for PCR . When compared with a Nested-PCR system to detect the urease A-subunit gene performed by a commercial reference laboratory, the results obtained (sensitivity 93.3% and specificity 73.3%) was almost equivalent . The PCR-MWP was rapid and easy for the detection of H . pylori DNA in gastric juice specimen. Eur J Cancer B Oral Oncol, 1996 Jul, 32B(4), 264 - 70 Human papillomavirus in oral premalignant lesions; Nielsen H et al.; The aetiology of oral premalignant lesions is generally accepted to be multifactorial . Tobacco and alcohol are established as important cofactors in malignant development in the oral cavity, but in addition microorganisms, such as human papillomavirus (HPV), have gained much interest over the past decade . For many years, HPV has been accepted as an important cofactor in the development of cervical cancer, originating from a mucous membrane with similarities to the oral mucosa . 49 patients with oral premalignant lesions and 20 control patients with normal oral mucosa and no history of HPV infection were examined for the presence of HPV by immune histochemical staining using the peroxidase anti-peroxidase technique (PAP), DNA-DNA in situ hybridisation (ISH), and polymerase chain reaction (PCR) analysed by Southern blot hybridisation with an HPV 16 specific probe . The investigations revealed that HPV was found in 62.5% of the verrucous leucoplakias, 50.0% of the erythroplakias, 45.5% of the homogeneous leucoplakias, 33.3% of erythroleucoplakias and in 12.5% of the nodular leucoplakias . An overall HPV detection rate in the examined premalignant lesions was 40.8% and no patients in the control sample were positive . Concerning oral cancer development, it seems likely that HPV may be a cofactor, as 100% of patients who developed oral cancers within 4-12 years were all positive for HPV, one being positive for HPV 16. Trends Genet, 1996 Jul, 12(7), 263 - 70 The yeast genome project: what did we learn? Dujon B. The bakers' yeast, Saccharomyces cerevisiae, a microorganism of major importance for bioindustries, and one of the favored model organisms for basic biological research, is the first eukaryote whose genome is entirely sequenced . Beyond the wealth of novel biological information, it is the extent of what remains to be understood in the genome of a simple unicellular organism that is the most striking result: a significant proportion of yeast genes are orphans of unpredictable function . Offering the possibility of large-scale reverse genetics, yeast will be a powerful model for post-sequencing studies . But geneticists are now faced with the difficulty of asking novel questions. Kyobu Geka, 1996 Jul, 49(8 Suppl), 630 - 5 {Clinical problems in surgical treatment for active infective endocarditis}; Emmoto T et al.; From October, 1982, to December, 1995, 22 patients with active infective endocarditis underwent surgical treatment . Of 22 patients, 12 patients (group P) demonstrated microorganisms on blood culture obtained at the operation and/or in the excised valve, and 10 patients (group N) showed acute inflammatory reaction in the excised valve microscopically . Operative mortality in group P was significantly higher than that in group N (50% versus 0%,p < 0.01) . Especially in group P, five of six patients (83%) with uncontorolled infection for more than eight days died within 30 days of operation . This showed that prolonged preoperative periods of uncontrolled infection influenced the surgical outcome of active infective endocarditis . In conclusion, patients who do not promptly response to antibiotic treatment must be considered for early operation within seven days of the diagnosis of infective endocarditis to decrease operative mortality . The plasma level of CRP and definition of sepsis may be useful as indicators of uncontrolled infection. Infect Immun, 1996 Jul, 64(7), 2649 - 56 The major surface glycoprotein of Trypanosoma cruzi amastigotes are ligands of the human serum mannose-binding protein; Kahn SJ et al.; Trypanosoma cruzi, an obligate intracellular protozoan parasite, chronically infects mammals and causes Chagas' disease in humans . T . cruzi evasion of the mammalian immune response and establishment of chronic infection are poorly understood . During T . cruzi infection, amastigotes and trypomastigotes disseminate in the mammalian host and invade multiple cell types . Parasite surface carbohydrates and mammalian lectins have been implicated in the invasion of mammalian cells . A recent study has demonstrated that the human mannose-binding protein and the macrophage mannose receptor, two mammalian C-type lectins, bind to T . cruzi (S . J . Kahn, M . Wleklinski, A . Aruffo, A . Farr, D . Coder, and M . Kahn, J . Exp . Med . 182:1243-1258,1995) . In this report we identify the major surface glycoproteins, including the SA85-1 glycoproteins, as T . cruzi ligands of the mannose-binding protein . Further characterization of the interaction between the mannose-binding protein and T . cruzi demonstrates that (i) the SA85-1 glycoproteins are expressed by amastigotes and trypomastigotes but only amastigotes express the mannose-binding protein ligand, (ii) treatment of amastigotes with alpha-mannosidase inhibits the binding of mannose-binding protein, and (iii) amastigote binding of mannose-binding protein is stable despite the spontaneous shedding of some glycoproteins from its surface . Together, the data indicate that developmentally regulated glycosylation of surface glycoproteins controls the expression of ligands that affect the interactions between T . cruzi and mannose-binding protein . It has been established that the binding of mannose-binding protein to microorganisms facilitates their uptake into phagocytic cells . Preferential opsonization of amastigotes with mannose-binding proteins may account for their clearance from the circulation and may contribute to the parasite's ability to invade different cell types. Infect Immun, 1996 Jul, 64(7), 2391 - 9 Ability of Escherichia coli isolates that cause meningitis in newborns to invade epithelial and endothelial cells; Meier C et al.; Escherichia coli isolates that cause meningitis in newborns are able to invade the circulation and subsequently cross the blood-brain barrier . One mechanism for traversing the blood-brain barrier might involve transcytosis through the endothelial cells . The ability of the meningitis isolate E . coli IHE3034, of serotype 018:K1:H7, to invade epithelial (T24) and endothelial (EA-hy926) cells was investigated by the standard gentamicin survival assay and by electron microscopy . Human bladder epithelial and endothelial cells were efficiently invaded by strain IHE3034, whereas epithelial human colon Caco-2 cells, canine kidney MDCK cells, and the opossum {correction of opposum} epithelial kidney cell line OK were not invaded . The ability to invade human epithelial cells of the bladder could also be demonstrated for several other newborn meningitis E . coli strains and one septicemic E . coli strain . Studies utilizing inhibitors which act on eukaryotic cells revealed a dependence on microfilaments as well as on microtubules in the process of E . coli IHE3034 entry into T24 and EA-hy926 cells . These results indicated that cell cytoskeletal rearrangements are involved in bacterial uptake and suggest that there are either two pathways (microtubule dependent and microfilament dependent) or one complex pathway involving both microtubules and microfilaments . The intracellular IHE3034 organisms were contained in a host-membrane-confined compartment mainly as single microorganisms . Intracellular replication of 1HE3034 was not detected, nor did the number of intracellular bacteria decrease significantly during a 48-h period . The ability of E . coli O18:K1 to invade and survive within certain eukaryotic cells may be another virulence factor of meningitis-associated E . coli. Gastroenterology, 1996 Jul, 111(1), 19 - 27 Association between Helicobacter and gastric ulcer disease of the pars esophagea in swine; Queiroz DM et al.; BACKGROUND & AIMS: Swine present spontaneously peptic ulcer in the gastric pars esophagea and are frequently colonized by a spiral bacterium that is of the same species as Helicobacter heilmannii type 1 . This organism is also observed in the gastric mucosa of patients with gastric symptoms and who present with gastritis at histology . The aim of this study was to investigate the association between the presence of H . heilmannii type 1 and lesions of the pars esophagea . METHODS: H . heilmannii type 1 infection was investigated by mouse inoculation, urease test, and carbolfuchsin stain in 20 stomachs with ulcer, 30 stomachs with preulcer lesions, and 20 stomachs with a macroscopically normal pars esophagea . RESULTS: The microorganism was more frequently found in the stomachs with ulcer (100%) and in those with preulcer lesions (90%) than in stomachs with macroscopically normal pars esophagea (35%) . Histological alterations were observed in the pars esophagea and in the glandular regions of bacterium-positive stomachs . CONCLUSIONS: It has been shown that the microorganism is strongly associated with naturally occurring ulcer and preulcer lesions of the pars esophagea of swine, which raises the possibility that the bacterium is an important factor in the pathogenesis of these lesions. Am J Respir Crit Care Med, 1996 Jul, 154(1), 91 - 7 Effect of ventilator-associated pneumonia on mortality and morbidity; Papazian L et al.; The aim of this study was to evaluate the attributable mortality and excess intensive care unit (ICU) stay as linked to ventilator-associated pneumonia (VAP) in a medical-surgical ICU . We performed a matched cohort study . The diagnosis of VAP was established when clinical, biologic, and radiologic signs of VAP were associated with the presence of at least one microorganism at a concentration > or = 10(3) CFU/ml on the protected specimen brush sample . Each case patient with VAP was matched to one control patient on the basis of the following potential confounding factors: same diagnosis and same indication for mechanical ventilation, same age +/-5 yr, same sex, same APACHE II score +/-5 on admission . In addition, control patients had to be ventilated for at least as long as the case patient prior to the onset of VAP, and date of admission of the case and control patients had to be matched within 1 yr . In 85 of the 97 patients with VAP, we were able to match one case patient with one control patient . Mortality was similar in both case (40%) and control (38.8%) patients . The duration of mechanical ventilation was increased in survivor case patients (27.2 +/- 24.7 d) compared with survivor control patients (18.5 +/- 15.7 d) (p < 0.01) . The duration of hospitalization in ICU was increased in survivor case patients (34.9 +/- 23.6 d) compared with survivor control patients (26.1 +/- 18.6 d) (p < 0.02) . When confounding factors were controlled, VAP did not appear to increase mortality. Microb Ecol, 1996 Jul, 32(1), 59 - 71 Relationship Between Abundance of N2-fixing Cyanobacteria and Environmental Features of Spanish Rice Fields Quesada A, Valiente EF. In order to estimate the potential utilization of N2-fixing (heterocystous) cyanobacteria as natural biofertilizers in the Valencian rice fields (Spain), the distribution and seasonal variation of these microorganisms in water and sediment samples were evaluated, and the relationships among cyanobacterial abundance and physical and chemical characteristics of soil and water were investigated . N2-fixing cyanobacteria were present in all the samples analyzed (25 sampling points sampled three times per year during two years) . The relative cyanobacterial abundance in soil and water followed contrasting patterns, maximum presence in soil coincided with minimum abundance in water . Correlation analysis showed that cyanobacterial abundance in the two phases (water and sediment) was influenced more by water than by soil properties . Salinity,mineralization variables, and soluble reactive phosphate (SRP) correlated positively with heterocystous cyanobacteria presence . Furthermore, dissolved inorganic nitrogen (DIN) and the ratio DIN:SRP correlated negatively with cyanobacterial abundance . However DIN:SRP ratio better described the cyanobacterial distribution, with a threshold effect: below the Redfield ratio value (7.2 in mass units) cyanobacterial abundance was clearly higher. Proc Natl Acad Sci U S A, 1996 Jun 25, 93(13), 6626 - 30 A human axillary odorant is carried by apolipoprotein D; Zeng C et al.; The characterization of the source of the odor in the human axillary region is not only of commercial interest but is also important biologically because axillary extracts can alter the length and timing of the female menstrual cycle . In males, the most abundant odor component is known to be E-3-methyl-2-hexenoic acid (E-3M2H), which is liberated from nonodorous apocrine secretions by axillary microorganisms . Recently, it was found that in the apocrine gland secretions, 3M2H is carried to the skin surface bound to two proteins, apocrine secretion odor-binding proteins 1 and 2 (ASOB1 and ASOB2) with apparent molecular masses of 45 kDa and 26 kDa, respectively . To better understand the formation of axillary odors and the structural relationship between 3M2H and its carrier protein, the amino acid sequence and glycosylation pattern of ASOB2 were determined by mass spectrometry . The ASOB2 protein was identified as apolipoprotein D (apoD), a known member of the alpha2mu-microglobulin superfamily of carrier proteins also known as lipocalins . The pattern of glycosylation for axillary apoD differs from that reported for plasma apoD, suggesting different sites of expression for the two glycoproteins . In situ hybridization of an oligonucleotide probe against apoD mRNA with axillary tissue demonstrates that the message for synthesis of this protein is specific to the apocrine glands . These results suggest a remarkable similarity between human axillary secretions and nonhuman mammalian odor sources, where lipocalins have been shown to carry the odoriferous signals used in pheromonal communication. Proc Natl Acad Sci U S A, 1996 Jun 25, 93(13), 6241 - 6 A psychrophilic crenarchaeon inhabits a marine sponge: Cenarchaeum symbiosum gen . nov., sp . nov; Preston CM et al.; Archaea, one of the three major domains of extant life, was thought to comprise predominantly microorganisms that inhabit extreme environments, inhospitable to most Eucarya and Bacteria . However, molecular phylogenetic surveys of native microbial assemblages are beginning to indicate that the evolutionary and physiological diversity of Archaea is far greater than previously supposed . We report here the discovery and preliminary characterization of a marine archaeon that inhabits the tissues of a temperate water sponge . The association was specific, with a single crenarchaeal phylotype inhabiting a single sponge host species . To our knowledge, this partnership represents the first described symbiosis involving Crenarchaeota . The symbiotic archaeon grows well at temperatures of 10 degrees C, over 60 degrees C below the growth temperature optimum of any cultivated species of Crenarchaeota . Archaea have been generally characterized as microorganisms that inhabit relatively circumscribed niches, largely high-temperature anaerobic environments . In contrast, data from molecular phylogenetic surveys, including this report, suggest that some crenarchaeotes have diversified considerably and are found in a wide variety of lifestyles and habitats . We present here the identification and initial description of Cenarchaeum symbiosum gen . nov., sp . nov., a symbiotic archaeon closely related to other nonthermophilic crenarchaeotes that inhabit diverse marine and terrestrial environments. J Immunol Methods, 1996 Jun 21, 193(2), 149 - 56 Assessment of in vivo attachment/phagocytosis by alveolar macrophages; Weaver T et al.; Alveolar macrophages (AMs) are recognized as an important first line of cellular host defense within the lung . Although mechanisms underlying AM response to microorganisms or particulates are well characterized in vitro, experimental approaches to the study of AMs in vivo are limited . To circumvent these limitations, a new assay was developed using fluorescently labelled liposomes or Pneumocystis carinii (PC) organisms which were administered intratracheally into mechanically ventilated rats . After 30 min, the lungs were lavaged and the percentage of administered liposomes or PC bound to AMs was determined by quantifying fluorescence . Factors known to enhance attachment/phagocytosis by AMs in vitro were assayed to determine their effect in vivo . For example, vitronectin (VN)-coated liposomes increased attachment from 25.2 +/- 2.4% to 47.2 +/- 3.0% (p < 0.001), while addition of VN increased the binding of PC to AMs from 16.5 +/- 1.7% to 24.5 +/- 2.2% (p < 0.05) . Confocal laser microscopy of cells obtained by lavage provided morphologic evidence of attachment/phagocytosis by AMs . This model will permit the quantitative assessment of the interaction of fluorescently labelled liposomes or microorganisms with AMs in the lower respiratory tract of living animals. J Cell Biochem, 1996 Jun 15, 61(4), 562 - 8 Carbohydrate-carbohydrate interactions in adhesion; Spillmann D et al.; Cell-cell interactions play an important role in the development, maintenance, and pathogenesis of tissues . They are highly dynamic processes which include migration, recognition, signaling, adhesion, and finally attachment . Cells on their pathway to a final location have to pass and interact with their substratum formed of matrix and cell layers . Testing and recognition are important keys for the proper result of tissue formation . They can, however, also lead to diseases when they are misused in pathological situations, by microorganisms or malignant cells, for instance . Carbohydrates, which are the most prominent surface-exposed structures, must play an important role as recognition molecules in such processes . The rich variability of carbohydrate sequences which cell surfaces can present to lectins, adhesion molecules, and other ligands creates a refined pattern of potential attachment sites . The subtle control of the surface presentation density can provide variations in attachment strength . Not only the carbohydrate sequences but also the fact that carbohydrates can be branched while proteins cannot and that the oligosaccharide chains can be attached to the protein backbone in different densities and patterns will create yet more interaction possibilities . Maximal use of the combinatorial richness of carbohydrate molecules would be made when carbohydrate sequences could interact with other carbohydrate sequences . Such interactions have only very rarely been considered for biochemically and biologically relevant situations since they are difficult to measure . A few are known and will be summarized here with the hope that this wealth of possible chemical interactions may be considered more and more by surface cell biochemists when analyzing fine tuning in cellular interactions. Clin Lab Sci, 1996 Jul-Aug, 9(4), 207 - 12 The laboratory diagnosis of tuberculosis in a period of resurgence: challenge for the laboratory; Amsterdam D; OBJECTIVE: To review the current and contemporary approaches to the laboratory diagnosis of Mycobacterium tuberculosis and related mycobacteria . DATA SOURCES: Current literature . STUDY SELECTION: Determined by the author . DATA EXTRACTION: Determined by the author . DATA SYNTHESIS: The definitive diagnosis of mycobacterial disease depends upon the laboratory for the isolation and identification of the infecting microorganism . Laboratory studies encompass microscopic examination for the presence of AFB; isolation and recovery of the organism by cultural methods; phenotypic biochemical or other contemporary means to identify the recovered organism; and anti-tuberculosis susceptibility testing . Because of the extended growth period of this group of organisms, it is imperative that the lab use the most rapid means to provide information to the clinician for isolation of the patient if needed and for the initiation of prompt rational therapy as determined by susceptibility testing . More than 25 species in the Mycobacterium genus are capable of causing human disease . In the United States, the five most frequently encountered species are M . tuberculosis, M . avium, M . kansasii, M . fortuitum and M . chelonei . CONCLUSION: Tuberculosis is a reemerging disease with significant health problem implications in the US and worldwide . Diagnosis and appropriate treatment are dependent on the prompt response of the laboratory. J Ind Microbiol, 1996 Jun, 16(6), 360 - 3 Genes, enzymes and secondary metabolites in industrial microorganisms . The 1995 Thom Award Lecture; Beppu T; Apparently contrasting approaches, ie genetic engineering and screening of new microorganisms, play essential complementary roles to develop current industrial microbiology . Three topics, production and modification of milk-clotting proteinases by genetic engineering, hormonal control of secondary metabolism in streptomycetes, and screening of bioactive metabolites, are introduced as cases of such a hybrid approach, while symbiotic microorganisms are discussed as an example of the vast terra incognita still remaining for the future microbiology. Arq Neuropsiquiatr, 1996 Jun, 54(2), 324 - 7 {Cerebral malaria and AIDS: case report}; Hinrichsen SL et al.; Although it has not been definitely proven that the severity of malaria is associated to human immunodeficiency virus (HIV) we know that infection through Plasmodium falciparum can favor a rapid evolution of the HIV infection . Besides, association of malaria with HIV/AIDS from a clinical point of view can be clinically severe in the face of the occurrence of other microorganisms or neoplasias, which worsens the evolution and prognosis of the affected patients . The concurrence of HIV with Plasmodium in malaria endemic zones is a possibility which should always be taken into consideration, since transmission is related to risk factors caused by people's behavior which are not always promptly revealed and/or identified . The authors report one case of brain malaria infection by Plasmodium vivax and Plasmodium falciparum in a patient with AIDS . They describe the clinical evolution and therapy. Ceska Gynekol, 1996 Jun, 61(3), 144 - 7 {Infectious agents and treatment of infertility with IVF and ET}; Dostal J et al.; An infectious agent is a confirmed etiological factor of female tubal sterility . In conjunction with the recorded decline of fertility of the male population the participation of infection in this trend can be taken into consideration . In the submitted paper the authors are concerned with the detection of an infectious agent in spermatozoa in the sterile population and its role when using assisted reproduction techniques (ART) . From the results ensues that cultivation examinations of spermatozoa before a programme of in vitro fertilization and embryo transfer (IVF + ET) has its place in the screening of the treated couple . Detection of virulent types of microorganisms has a negative effect on results of IVF + ET . Groups of men with this finding should be treated with antibiotics with regard to sensitivity and at the same time cultivation examinations of their partners should be made an necessary treatment and provided. Rev Sci Tech, 1996 Jun, 15(2), 409 - 22 Importation of aquaculture seedlings to Japan; Wakabayashi H; Japan is one of the largest consumers of fishery products in the world . Importation of various fishery commodities - including larvae and eggs for aquaculture - is increasing due to high consumer demand . Elvers of Anguilla anguilla have been imported from Europe since the late 1960s . Eyed eggs of coho salmon (Oncorhynchus kisutch) are imported from North America . During the last decade, over-production caused the price of Japanese amberjack (or 'yellowtail') (Seriola quinqueradiata) and Japanese seabream (Pagrus major) to drop, forcing farmers to venture into the culture of other species . A variety of marine fish seedlings are now imported from Asian countries . Almost all aquaculture production of coho salmon, greater amberjack (Seriola dumerili), seabass (Lateolabrax japonicus), rockfish (Sebastes spp.) and groupers (Epinephlus septemfaciatus, etc.) depends on imported seedlings . These species accounted for approximately 9% by value of marine finfish production in Japan in 1993 . Apart from ubiquitous or endemic pathogens, a considerable number of exotic microorganisms and parasites are suspected to have accompanied fish eggs and larvae imported for aquaculture purposes . On a voluntary basis, 80-90% of imported salmon eggs are being examined for bacterial kidney disease and salmon viruses by semi-governmental organisation . Voluntary inspections are also being conducted on some other fish species imported from foreign countries . No legislation exists, however, for the control of exotic fish pathogens. Int J Food Microbiol, 1996 Jun, 30(1-2), 113 - 23 Sensitive populations: who is at the greatest risk? Gerba CP, Rose JB, Haas CN. The purpose of this article was to review the existing literature to define those groups of individuals who would be at the greatest risk of serious illness and mortality from water and foodborne enteric microorganisms . This group was found to include the very young, the elderly, pregnant women, and the immunocompromised . This segment of the population currently represents almost 20% of the population in the United States and is expected to increase significantly by the beginning of the next century, because of increases in life-span and the number of immunocompromised individuals . More than half of documented deaths from gastroenteritis and hepatitis A illness occur in the elderly in developed countries . The overall case fatality ratio for foodborne bacterial gastroenteritis outbreaks in nursing homes is 10 times greater than the general population . Pregnant mothers suffer from a case fatality ratio from hepatitis E infections ten times greater than the general population during waterborne disease outbreaks . Enteric diseases are most common and devastating among the immunocompromised . Cryptosporidium is a serious problem among patients with acquired immuno-deficiency syndrome (AIDS) . Cancer patients undergoing chemotherapy and transplant patients, are also at significantly greater risk of dying from enteric viral infections than the general population . This review indicates the need for consideration of enhanced protection for certain segments of the population who will suffer the most from food and waterborne pathogens. Eur J Oral Sci, 1996 Jun, 104(3), 322 - 4 Elevated cortisol levels in whole saliva in HIV infected individuals; Enwonwu CO et al.; Free cortisol concentrations in unstimulated whole saliva samples, collected at 10.00 to 11.00 h, from 23 unmedicated HIV-positive patients and 14 control subjects were measured by radioimmunoassay . Mean cortisol level (nmol/l +/- SD) was significantly higher in the HIV patients than in control subjects (27.4 +/0 9.3 vs . 10.1 +/- 3.5) . Two HIV patients with pseudomembranous candidiasis had the highest saliva cortisol concentrations (mean of 48.5 nmol/l) . Two other HIV patients (one with Kaposi's sarcoma and the other with periodontitis) had a mean cortisol value of 29.9 nmol/l . The possibility of plasma contamination of whole saliva in the HIV patients with inflammatory oral mucosal lesions notwithstanding, our findings suggest an increased oral burden of cortisol in both the asymptomatic and symptomatic HIV-infected individuals . Glucocorticoids caused immunosuppression, provide selective growth advantage to various microorganisms including the fungi, and enhance replication or reactivation of latent viruses (e.g . EBV, CMV, Kaposi's sarcoma-associated herpes viruses) . Our findings suggest a need to evaluate the relevance of endogenous glucocorticoid excess in blood and saliva to the causation of some major AIDS-associated oral lesions such as candidiasis, Kaposi's sarcoma, oral hairy leukoplakia and necrotizing gingivitis. Curr Opin Obstet Gynecol, 1996 Jun, 8(3), 211 - 5 Contraception in the 1990s; Shoupe D; Contraceptive technology has recently provided the market place with new barrier methods, new progestin oral contraceptives, an injectable contraceptive, the female condom, new male condoms, and the contraceptive implant . During the last decade, epidemiologists have clearly defined the non-contraceptive benefits of current contraceptive methods that include decreased infections, protection from various cancers, protection from many gynecologic problems that lead to surgery, as well as symptomatic relief from many gynecologic conditions . In conjunction with medical specialists, contraceptive researchers have established the increased safety and benefits of various contraceptive choices in women with medical conditions that, until recently, were contra-indications for their use . That these advances have occurred despite multiple legal and scientific assaults gives hope that the field will continue to growPIP: In the face of legal challenges and adverse scientific publications that threaten the acceptance of various methods of contraception, this article reviews the forms of contraception currently available in the US and assesses their safety, efficacy, and medical benefits . Information is provided on 1) male and female condoms, which offer protection from pregnancy and from sexually transmitted diseases; 2) the spermicide Nonoxynol-9, which kills harmful microorganisms but is toxic to vaginal epithelium; 3) the contraceptive sponge; 4) the diaphragm (used with spermicides) and cervical cap; 5) Norplant, which is associated with troublesome side effects but still scores 78% satisfaction ratings; 6) Depo-Provera, which has been associated with bone loss; and 7) IUDs, which were used by 10% of women in the 1970s but are used by less than 2% today . The bulk of the report is devoted to oral contraceptives (OCs), which are described as "one of the most thoroughly studied pharmacological agents of the 20th century." The risks associated with OC use are reviewed, as are such topics as failure rates, mechanism of action, side effects, beneficial effects, effects of use on cancer rates, safety for breast-feeding women, contraindications, and the risk of venous thromboembolism associated in recent studies with formulations containing third-generation progestins . It is concluded that the development of contraceptive technology is being guided by a new emphasis on protecting health while preventing pregnancy . Pharmacol Rev, 1996 Jun, 48(2), 289 - 326 Toxicology and pharmacology of the chemical warfare agent sulfur mustard; Dacre JC et al.; There have been reports of chemical attacks in which sulfur mustard might have been used (a) on Iranian soldiers and civilians during the Gulf War in 1984 and 1985 and (b) in an Iraqi chemical attack on the Iranian-occupied village of Halbja in 1988, resulting in many civilian casualties . Heavy use of chemical warfare in Afghanistan by the Soviet military is a recent innovation in military tactics that has been highly successful and may ensure further use of chemical agents in future military conflicts and terrorist attacks as a profitable adjunct to conventional military arms . Mustard is a poisonous chemical agent that exerts a local action on the eyes, skin, and respiratory tissue, with subsequent systemic action on the nervous, cardiac, and digestive systems in humans and laboratory animals, causing lacrimation, malaise, anorexia, salivation, respiratory distress, vomiting, hyperexcitability, and cardiac distress . Under extreme circumstances, dependent upon the dose and length of exposure to the agent, necrosis of the skin and mucous membranes of the respiratory system, bronchitis, bronchopneumonia, intestinal lesions, hemoconcentration, leucopenia, convulsions with systemic distress, and death occur . Severe mustard poisoning in humans is associated with systemic injury, which is manifested as headache, epigastric distresses, anorexia, diarrhea, and cachexia and is usually observed at mustard doses of 1000 mg/min/m3 with damage to hematopoietic tissues and progressive leucopenia . Sulfur mustard is a cell poison that causes disruption and impairment of a variety of cellular activities that are dependent upon a very specific integral relationship . These cytotoxic effects are manifested in widespread metabolic disturbances whose variable characteristics are observed in enzymatic deficiencies, vesicant action, abnormal mitotic activity and cell division, bone marrow disruption, disturbances in hematopoietic activity, and systemic poisoning . Indeed, mustard gas readily combines with various components of the cell such as amino acids, amines, and proteins . Although evidence of an association between lung cancer and mustard gas encountered on the battlefields of World War I is at best suggestive if not problematical (Case and Lea, 1955; Beebe, 1960; Norman, 1975), the epidemiological data accumulated from the poison gas factories in Japan (Yamada et al., 1953; Wada et al., 1968; Inada et al., 1978; Shigenobu, 1980; Nishimoto et al., 1983; Hirono et al., 1984; Takuoka et al., 1986), in Germany (Weiss, 1958; Hellmann, 1970a; Weiss and Weiss, 1975; Klehr, 1984) and in England (Manning et al., 1981; Easton et al., 1988) are substantial (International Agency for Research on Cancer, 1975) . Unfortunately, attempts to seek confirmatory and substantial evidence in laboratory animals such as mice (Boyland and Horning, 1949; Heston, 1950; Heston, 1953a; McNamara et al., 1975) and rats (Griffin et al., 1951; McNamara et al., 1975; Sasser et al., 1996) have not been consistent . Sulfur mustard has been shown to be mutagenic in a variety of different species using many different laboratory techniques from fruit flies, microorganisms and mammalian cell cultures (Fox and Scott, 1980) . Evidence is slowly accumulating from human data (Hellmann, 1970a; Lohs, 1975; Wulf et al., 1985) . Evidence for the teratogenicity of mustard has been negative in assessment of fetotoxicity and adverse effects of mustard on the reproductive potential of both human and animal studies . Indeed, investigations of women adversely affected by mustard are minimal because most of the studies have been performed on former men employees of poison gas factories and have been negative or questionable . We have recently emphasized the need to assess the affect of a suspected teratogen on maternal toxicity in laboratory animals before any conclusions can be made.(ABSTRACT TRUNCATED) Appl Environ Microbiol, 1996 Jun, 62(6), 1913 - 21 Ribulose-1,5-bisphosphate carboxylase/oxygenase gene expression and diversity of Lake Erie planktonic microorganisms; Xu HH et al.; Carbon dioxide fixation is carried out primarily through the Calvin-Benson-Bassham reductive pentose phosphate cycle, in which ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO) is the key enzyme . The primary structure of the large subunit of form I RubisCO is well conserved; however, four distinct types, A, B, C, and D, may be distinguished, with types A and B and types C and D more closely related to one another . To better understand the environmental regulation of RubisCO in Lake Erie phytoplanktonic microorganisms, we have isolated total RNA and DNA from four Lake Erie sampling sites . Probes prepared from RubisCO large-subunit genes (rbcL) of the freshwater cyanobacterium Synechococcus sp . strain PCC6301 (representative of type IB) and the diatom Cylindrotheca sp . strain N1 (representative of type ID) were hybridized to the isolated RNA and DNA . To quantitate rbcL gene expression for each sample, the amount of gene expression per gene dose (i.e., the amount of mRNA divided by the amount of target DNA) was determined . With a limited number of sampling sites, it appeared that type ID (diatom) rbcL gene expression per gene dose decreased as the sampling sites shifted toward open water . By contrast, a similar trend was not observed for cyanobacterial (type IB) rbcL gene expression per gene dose . Complementary DNA specific for rbcL was synthesized from Lake Erie RNA samples and used as a template for PCR amplification of portions of various rbcL genes . Thus far, a total of 21 clones of rbcL genes derived from mRNA have been obtained and completely sequenced from the Ballast Island site . For surface water samples, deduced amino acid sequences of five of six clones appeared to be representative of green algae . In contrast, six of nine sequenced rbcL clones from 10-m-deep samples were of chromophytic and rhodophytic lineages . At 5 m deep, the active CO2-fixing planktonic organisms represented a diverse group, including organisms related to Chlorella ellipsoidea, Cylindrotheca sp . strain N1, and Olisthodiscus luteus . Although many more samplings at diverse sites must be accomplished, the discovery of distinctly different sequences of rbcL mRNA at different water depths suggests that there is a stratification of active CO2-fixing organisms in western Lake Erie. Curr Opin Biotechnol, 1996 Jun, 7(3), 321 - 5 Co-metabolism: is the emperor wearing any clothes? Wackett LP. Co-metabolism is a term used for biochemically undefined observations in catabolic enzyme substrate specificity, the interplay between enzyme specificity and metabolic regulation, the metabolic interdependence of microorganisms, and co-substrate requirements in the catabolism of xenobiotic compounds . Recent findings in these four areas of microbial biochemistry necessitate a re-evaluation of the widespread use of the term. Clin Infect Dis, 1996 Jun, 22(6), 1096 - 8 Lymphocyte subset counts during the course of community-acquired pneumonia: evolution according to age, human immunodeficiency virus status, and etiologic microorganisms; Fantin B et al.; We investigated the evolution of lymphocyte subsets in blood samples from 94 consecutive patients with community-acquired pneumonia; these samples were obtained 72 hours after hospitalization and at follow-up, when the patients were considered to be cured . Acute-phase lymphocyte counts, as compared with follow-up counts, were decreased in the overall population (P < .0001); however, the percentage of CD4+ T cells remained unchanged during the course of pneumonia in each patient . These changes that were noted for the overall population were not significantly influenced by age, the presence (or not) of infection with human immunodeficiency virus (HIV), or etiologic microorganisms . Of the 68 HIV-seronegative patients, 12 had initial CD4+ T cell counts of < 200/mm3; multivariate analysis revealed that this finding was significantly associated with the presence of an underlying disease or tuberculosis and an age of > or = 60 years. Clin Perinatol, 1996 Jun, 23(2), 287 - 304 Neonatal gastrointestinal mucosal immunity; Mannick E et al.; The gastrointestinal mucosal immune system is a complex system with multiple interacting cells, which express different markers and elaborate a variety of mediators in response to noxious stimuli and pathogens . At birth this system is quite immature, putting the newborn mammal at risk for a variety of infectious and noninfectious diseases . With age and antigenic stimulation, maturation occurs and intestinal host defense then functions quite effectively to protect the host from ingested noxious substances and microorganisms. Microbiologia, 1996 Jun, 12(2), 207 - 18 Molecular basis of Brucella pathogenicity: an update; Sangari FJ et al.; Microorganisms belonging to the genus Brucella can infect humans and many species of animals . Virulence of the brucellae is thought to be essentially due to their capacity to survive and replicate within the phagocytic cells . However, many gaps remain in our understanding of this ability of brucellae to elude the bactericidal effects of host phagocytes, and basic questions remain unanswered . Identification of Brucella gene products which are related to intracellular survival, as well as those which contribute to the induction of protective immunity, is critical to elucidate the molecular mechanisms of the pathogenesis of the organism . The present article summarizes the current status of the research on gene products and other structural or metabolic factors associated with virulence of the brucellae. Monaldi Arch Chest Dis, 1996 Jun, 51(3), 188 - 93 Changes of serum concentration of lipid peroxidation products in patients with pneumonia; Nowak D et al.; During lower respiratory tract infection, massive influx and activation of phagocytes is observed . Reactive oxygen species (ROS) released by macrophages and polymorphonuclear neutrophils (PMNs) kill microorganisms and cause damage to host tissues . One feature of this damage may be enhanced lipid peroxidation . Therefore, the aim of this study was to estimate the serum concentration of lipid peroxidation products in combination with clinical and biochemical indicators of inflammation in 32 patients with pneumonia . Serum concentration of lipid peroxides (CLP) and malondialdehyde (CMDA) was measured at Day 1, 4, 10 and 14 of observation, whilst chest radiography and routine blood analysis were performed at Day 1 and 14 during a 2 week treatment of lower airway infection . The CLP decreased during treatment (p < 0.05) from 0.059 +/- 0.024 to 0.043 +/- 0.017 (A532 nm) and the CMDA (p < 0.05) from 3.5 +/- 1.4 to 2.8 +/- 1.3 nmol.mL-1 . A negative correlation between CLP and radiological regression (r = 0.49) and a drop in white blood cell count (WBC) (r = 0.39) was observed during the treatment . A positive correlation between CMDA and serum trypsin inhibitory capacity (STIC) (r = 0.47) and erythrocyte sedimentation rate (ESR) (r = 0.43) was found . Our data ind