Bacteriological

Med Prog Technol, 1993, 19(2), 83 - 8
VAD Biomer blood sacs: mechanical tests and ultrastructural observations; Bedini R et al.; Ventricular Assist Devices (VADs) are a support to the heart function and are used as bridge to transplantation for a brief period in patients awaiting a donor heart . They consist of two sacs with two artificial valves that allow blood flow, the whole connected to a specific electronic equipment . This study examines the performance of a segmented-polyurethane elastomer, namely Biomer, that has been extensively used to manufacture pneumatically actuated VAD blood sacs . Specimens obtained from three VAD blood sacs explanted from three human patients and specimens from one unimplanted blood sac were investigated for mechanical performance of the material and for the changes it undergoes as a result of mechanical stress and interaction with the surrounding biological environment . The application of tensile strength at break yielded no relevant differences between unimplanted and explanted specimens . Biomer exhibited a high elongation at break for both groups, with somewhat lower values for explanted specimens . SEM observations carried out on the inner surface--in contact with blood--of unstressed explanted specimens showed no thrombotic deposits, calcifications, microbial contamination or structural changes . The complementary broken surfaces of stressed specimens showed a distinctive fracture pattern.

Adv Protein Chem, 1993, 44, 99 - 123
PapD and superfamily of periplasmic immunoglobulin-like pilus chaperones; Hultgren SJ et al.; The formation of a P pilus requires a molecular chaperone in the periplasm and a molecular usher in the outer membrane . Each pilus is composed of six different types of proteins that are assembled into a composite fiber in a defined order . The correct folding of subunits into domains that can serve as assembly modules requires an association with the periplasmic chaperone . PapD is the prototype member of the family of bacterial pilus chaperones that have a three-dimensional structure consistent with an immunoglobulin fold . In general, proteins with an immunoglobulin fold structure have molecular recognition functions in eukaryotic cells that are often integrated with effector functions . PapD has also a recognition function, binding nascently translocated pilus subunits and maintaining them in assembly-competent conformations . The association of the chaperone with the subunit triggers the targeting of the latter to an outer membrane usher . The usher serves as a molecular gatekeeper, allowing the ordered incorporation of the pilus subunits into the pilus structure from the periplasmic chaperone complexes . The two immunoglobulin-like domains of PapD are oriented to form a cleft that contains the subunit binding site . This is a different binding paradigm from that used by either antibodies or the growth hormone receptor . The blend of genetics, biochemistry, X-ray crystallography, and carbohydrate chemistry in the study of pili biogenesis will continue to give insight into some of the most basic intellectual challenges in molecular biology concerning how proteins fold into domains that serve as modules for the formation of larger assemblies, and relating these processes to microbial pathogenesis.

Antonie Van Leeuwenhoek, 1993-94, 64(2), 177 - 86
A-factor and streptomycin biosynthesis in Streptomyces griseus; Horinouchi S et al.; Accumulating data have shown that the metabolites with a gamma-butyrolactone ring functions as an autoregulatory factor or a microbial hormone for the expression of various phenotypes not only in a variety of Streptomyces spp . but also in the distantly related bacteria . A-factor, as a representative of this type of autoregulators, triggers streptomycin biosynthesis and cellular differentiation in Streptomyces griseus . A model for the A-factor regulatory cascade on the basis of recent work is as follows . At an early step in the A-factor regulatory relay, the positive A-factor signal is first received by an A-factor receptor protein that is comparable in every aspect to eukaryotic hormone receptors, and then, via one or more regulatory steps, transmitted to an A-factor-responsive protein that binds to the upstream activation sequence of the strR gene, a regulatory gene in the streptomycin biosynthetic gene cluster . The StrR protein thus induced appears to activate the other streptomycin biosynthetic genes . This review summarizes the characteristics of A-factor as a microbial hormone and the A-factor regulatory relay leading to streptomycin production.

Zh Mikrobiol Epidemiol Immunobiol, 1993 Jan-Feb, (1), 40 - 5
{The structure of populations of the causative agents of infectious diseases and the mechanism of the development of the epidemic process}; Beliakov VD et al.; The parameters of clonality and preservation capacity, characterizing the population structure of the causative agents of infectious diseases, have been worked out on the basis of the clonal concept and the concept of self-restructuring of microbial populations . Different correlations between these parameters determine the existence of 9 independent groups of infections . The mechanisms and manifestations of the epidemic process of these infections have been described and the priority directions of anti-epidemic measures formulated.

Antibiot Khimioter, 1993 Jan, 38(1), 28 - 33
{Clinical regularities of the interaction of pancreatic and microbial RNase with cells in vitro}; Kurinenko BM et al.; The kinetics of interaction of exogenic RNAses with isolated cell culture of the human amnion FL was studied in a mathematical model . It was shown that by a number of kinetic parameters the pancreatic RNAse had higher affinity to the cells which quite agreed with higher cytotoxicity of the enzyme as compared to that of the microbial RNAse in regard to the cell culture.

Rev Roum Virol, 1993 Jan-Jun, 44(1-2), 61 - 7
{The pathomorphological aspects of arteriopathies associated with viral and microbial infections}; Petica M et al.; Presence of Mycoplasma, Chlamydia, Rickettsia burnetii, influenza type B, herpes and adenoviruses was detected by immunofluorescence in artery fragments collected from patients with arteriopathy . Pathohistological examination of the samples revealed inflammatory--lympho-histiocytic infiltration--and mostly dystrophic alterations . Arteriopathies were localised mostly at the pelvic limb level, especially on femoral artery . Their incidence was statistically significant.

Biodegradation, 1993, 4(2), 101 - 5
A microbial biosensor system for dihalomethanes; Henrysson T et al.; A biosensor system able to measure dichloromethane (DCM) and other dihalomethanes has been developed . The analysis is based on Hyphomicrobium DM2 cells immobilized in alginate . A combination of transducers consisting of a flow-calorimeter followed by a chloride-sensitive electrode has been used . By this design it was possible to monitor different aspects of the cell metabolism from one and the same pulse of substrate . The detection limit for the biosensor was 0.1 microM dichloromethane . The biosensor system can be used for continuous measurements in a sample stream.

Genet Eng (N Y), 1993, 15, 225 - 36
The use of microparticle injection to introduce genes into animal cells in vitro and in vivo; Johnston SA et al.; The biolistic technology has had a tremendous impact on plant and microbial research and development . The experience to date indicates that it should also have important uses with animal applications . The in-chamber system should prove increasingly valuable for transfecting non-dividing cells, primary cells, and other difficult-to-transfect targets . The hand-held version is currently useful for in situ transfection of cells in skin, but has limited effectiveness for internal organ transfection . This limitation may be lessened with further improvements in gun design and microprojectile coating . For gene therapy the most promising applications of this technology appear to be for genetic immunization and protocols which elicit an anti-tumor response.

Planta, 1993, 189(4), 561 - 6
Physiological and biochemical characterization of glyoxalase I, a general marker for cell proliferation, from a soybean cell suspension; Paulus C et al.; Using a strictly auxin-dependent soybean (Glycine max (L.) Merr.) cell suspension, we studied the correlation of auxin-dependent cell proliferation and the activity of glyoxalase I (S-lactoylglutathione-lyase EC 4.4.1.5), and enzyme generally associated with cell proliferation in animal, microbial and, as reported recently, also plant systems . We found the activity of glyoxalase I to be modulated during the proliferation cycle, with a maximal activity between day 2 and day 4 of culture growth . After starving the culture of auxins for three subsequent periods, both the enzyme activity and cell-growth could be re-initiated with auxin . Enzyme activity reached its maximum 1 d before cell number was at a maximum . The enzyme was purified to homogeneity and characterized.

Biotechnol Prog, 1993 Jan-Feb, 9(1), 81 - 5
Application of an on-line turbidimeter for the automation of fed-batch cultures; Yamane T; Recent advances in the technology of continuous in situ turbidity measurements in microbial cultivations are reviewed . Some characteristics of commercially available on-line laser turbidimeters are estimated in relation to requirements of sensors for microbial cultures . A system for the automation of fed-batch cultures using an on-line turbidimeter is proposed . Experimental data are presented concerning fed-batch cultures grown on synthetic and natural complex media . In situ turbidity data were found to be particularly useful for the automation of the feeding of natural complex nutrient solutions by converting the data into dry cell mass concentration and at the same time utilizing the instantaneous data on the culture broth volume through a computer.

J Gerontol, 1993 Jan, 48(1), M19 - 25
Transient normalization of lymphocyte blastogenic and specific antibody responses following boosting of healthy elderly subjects with tetanus toxoid; Armitage KB et al.; The diminished in vitro blastogenic response of lymphocytes from the elderly to mitogenic stimuli is cited as evidence of immunosenescence, but the response to specific microbial antigens has not been well characterized . We measured the response to tetanus toxoid before and after boosting in young and elderly subjects . Elderly subjects (age > or = 70) and young controls (age < 35) were subjected to clinical, laboratory, and nutritional evaluation to ensure a cohort of healthy subjects . Responses of lymphocytes from the elderly to the mitogens phytohemagglutinin and concanavalin A were markedly diminished compared to those from the young . For all subjects, the average in vitro blastogenic response to tetanus toxoid of lymphocytes from elderly subjects (n = 23) was significantly diminished compared to young controls (n = 23; 31,985 +/- 4502 vs 14,411 +/- 3714 cpm, p < .01) . Following boosting with tetanus in those subjects in whom boosting with tetanus toxoid was indicated, blastogenesis was comparable between elderly (n = 17) and young subjects (n = 7; 38,078 +/- 11,451 vs 42,103 +/- 9247 cpm) . The boosted response to tetanus apparently was not sustained, since in the subset of subjects with a history of tetanus immunization in the past 10 years, the response of the elderly was much less than that of the young . Thus, a cohort of healthy elderly with diminished blastogenic responses to mitogens was capable of at least a transiently normal response to tetanus post boosting.

FEMS Microbiol Lett, 1992 Dec 15, 79(1-3), 461 - 7
Diversity of Pseudomonas plasmids: to what extent?
Boronin AM.
Results obtained in studies of the biology of Pseudomonas plasmids are presented here as a mini-review . These data indicate that plasmids are ubiquitous in Pseudomonas, but the frequency of their occurrence varies greatly in particular species, or groups of species and in different microbial habitats . Some species of Pseudomonas, for instance P . aeruginosa, possess great diversity of plasmids both from the viewpoint of their incompatibility properties and their ability to endow bacteria with additional features such as resistance to antibiotics or heavy metals, degradation of xenobiotics or inhibition of phage development.

FEMS Microbiol Lett, 1992 Dec 15, 79(1-3), 169 - 76
Physiological and energetic aspects of bacterial metabolite overproduction; Tempest DW et al.; This review attempts to provide a rational explanation for microbial metabolite over-production, a phenomenon manifest with many wild-type and mutant organisms . After analysing the relationships between catabolic and anabolic processes within the growing cell (which point to the presence of sufficient kinetic control elements to ensure a stringent coupling between the two), consideration is given to mechanisms that might allow the rate of catabolism to be varied independently of the rate of anabolism . It is in this latter context that an excretion of specific metabolites appears to play a key role.

Aliment Pharmacol Ther, 1992 Dec, 6(6), 659 - 69
Review article: urease, gastric ammonium/ammonia, and Helicobacter pylori--the past, the present, and recommendations for future research; Graham DY et al.; The presence of ammonium in gastric contents was described in 1852; urease activity in the stomach was identified 70 years later . The discovery of gastric urease resulted in intense research activity to discover its origin, function, and relation to the gastric levels of ammonium and urea . Interest in urease waned in the 1960s as most pertinent questions appeared to have been addressed and there was strong evidence that gastric urease was not a property of the stomach but was of microbial origin . Identification of Helicobacter pylori as the source of urease in the stomach in the last decade has resulted in a rebirth of interest in gastric urease and its products . There is little actual evidence to support a role for toxicity of ammonia in relation to H . pylori and the bulk of the evidence suggests that the products of urease activity are not toxic and may even be beneficial . The purpose of this review is to examine the older literature and to examine new findings in the perspective of what is already known and to suggest areas remaining to be examined . We ask, 'What is old, what is new, and what needs to be done?'

Nature, 1992 Dec 10, 360(6404), 593 - 7
CD1b restricts the response of human CD4-8- T lymphocytes to a microbial antigen; Porcelli S et al.; Molecules encoded by the human CD1 locus on chromosome 1 (ref . 33) are recognized by selected CD4-8- T-cell clones expressing either alpha beta or gamma delta T-cell antigen receptors . The known structural resemblance of CD1 molecules to antigen-presenting molecules encoded by major histocompatibility complex (MHC) genes on human chromosome 6 (refs 3, 4, 34, 35), suggested that CD1 may represent a family of antigen-presenting molecules separate from those encoded in the MHC . Here we report that the proliferative and cytotoxic responses of human CD4-8- alpha beta TCR+ T cells specific for Mycobacterium tuberculosis can be restricted by CD1b, one of the four identified protein products of the CD1 locus . The responses of these T cells to M . tuberculosis seemed not to involve MHC encoded molecules, but were absolutely dependent on the expression of CD1b by the antigen-presenting cell and involved an antigen processing requirement similar to that seen in MHC class II-restricted antigen presentation . These results provide, to our knowledge, the first direct evidence for the proposed antigen-presenting function of CD1 molecules and suggest that the CD1 family plays a role in cell-mediated immunity to microbial pathogens.

Thorax, 1992 Dec, 47(12), 1015 - 8
Notification of tuberculosis: how many cases are never reported?
Sheldon CD, King K, Cock H, Wilkinson P, Barnes NC.
BACKGROUND: Notification of tuberculosis is essential for local contact tracing and for assessing the national incidence of tuberculosis . The accuracy of notification figures is uncertain . This study examined the notification rates of all patients diagnosed as having tuberculosis at two hospitals in the East End of London over five years . METHODS: In a retrospective survey of all patients aged 16 years or more presenting with tuberculosis to the London Chest Hospital or the Royal London Hospital from 1 January 1985 to 31 December 1989, cases of tuberculosis were identified from microbiology and histology records, statutory notifications, necropsy reports, coroners' records, hospital activity data, and death certificates . Clinical data were obtained from case notes and notification was determined from the local authority notification lists . RESULTS: Six hundred and nine adult patients with tuberculosis were identified . Notes were available for 580 cases (95%), of which 426 (73%) had been notified . The proportion of cases notified varied according to the specialty of the clinician in charge of the patient at diagnosis . Patients with a past history of tuberculosis and those who died within one year were less likely to have had their tuberculosis notified . Age, race, and lack of microbial or histological confirmation of diagnosis did not influence the proportion of cases notified . One hundred and eighty five patients had smear positive sputum, but 25 of these cases (14%) were not notified . Eighty five patients who had presented with pulmonary tuberculosis did not have their disease notified; 20 (24%) had smear positive sputum . CONCLUSIONS: Many cases of tuberculosis are not notified (27%) . Fourteen per cent of all sputum smear positive cases of tuberculosis were not notified, and these patients are a considerable public health risk . The true incidence of tuberculosis in the area studied is at least one third higher than current notification figures suggest.

J Antibiot (Tokyo), 1992 Dec, 45(12), 1837 - 47
Production of new anthracycline antibiotics by microbial 4-O-methylation using a specific daunorubicin-negative mutant; Johdo O et al.; Microbial 4-O-methylation using a specific daunorubicin-blocked, nonproducing mutant provided the new anthracycline antibiotics 4-O-methylbetaclamycin T, 4-O-methylyellamycin A and 4-O-methyl-13-hydroxyoxaunomycin, from which 4-O-methyloxaunomycin and 4-O-methyl-6-deoxyoxaunomycin were then prepared by further photochemical N-demethylation . Antitumor activities in vitro and in vivo against L1210 cells were compared with those of their 4-O-demethyl derivatives . It was found that all the 4-O-methyl derivatives had a markedly reduced cytotoxicity in vitro as compared with the 4-O-demethyl compounds . However, some of them were endowed with a significantly improved antitumor activity in vivo.

Pharm Res, 1992 Dec, 9(12), 1540 - 5
Hydrogels for site-specific drug delivery to the colon: in vitro and in vivo degradation; Brondsted H et al.; Novel hydrogels based on N,N-dimethylacrylamide, N-t-butylacrylamide, and acrylic acid cross-linked with azoaromatic compounds of varying length and electron density of the azo bond were synthesized . The cross-links are degradable by microbial azoreductases present predominantly in the colon, and the gels appear to be suitable for colon-specific drug delivery . The degradability in vitro and in vivo was found to be related to the degree of swelling of the gels . The higher the degree of swelling, the higher the degradability . However, structural and electronic factors were also shown to influence reduction of azo bonds.

Steroids, 1992 Dec, 57(12), 579 - 92
The cortisone era: aspects of its impact . Some contributions of the Merck Laboratories; Hirschmann R; The announcement in 1949, by Hench at the Mayo Clinic, that cortisone had a dramatic beneficial effect on bed-ridden patients suffering from rheumatoid arthritis ushered in the cortisone era . This medical landmark was made possible by the prior steroid research of distinguished chemists and biologists in several countries . The first partial synthesis of cortisone by Sarett was the culmination of a worldwide chemical effort . This work ultimately enabled the process research department at Merck, under the direction of Max Tishler, to perform the 37-step conversion of deoxycholic acid to cortisone on a scale that made the initial clinical trials possible . In spite of the enormity of the project, and the fact that neither of two closely related analogs of cortisone had shown any interesting biological activity . Merck elected to embark on this synthetically challenging project . The clinical results reported in 1949, combined with the complexity of the partial synthesis, stimulated highly innovative research to discover new routes to cortisone and to cortisol, the active hormone . This research, particularly in the pharmaceutical industry in the United States, Mexico, and Europe, demonstrated, among other things, the value of microbial transformations in synthetic sequences . The recognition that the chronic administration of cortisol produces several unexpected side effects stimulated an intensive effort in many countries to discover an analog with an improved therapeutic index . This led to more novel chemistry and many analogs were discovered that proved to be more potent than cortisol . Prednisolone, discovered at the Schering Corporation, was the first compound that combined a high level of anti-inflammatory activity with reduced salt retention . Derek Barton contributed greatly to steroid research during the 1950s by applying creative structural thinking to systematize a host of seemingly unrelated chemical and biological observations . The cortisone era had a profound impact on drug discovery also, since it led to the logical application of steric and electronic concepts to medicinal chemistry . Last, but not least, the cortisone era taught medicinal chemists many important lessons about drug-receptor interactions.

Microbiol Rev, 1992 Dec, 56(4), 561 - 76
Biological control of chestnut blight: an example of virus-mediated attenuation of fungal pathogenesis; Nuss DL; Environmental concerns have focused attention on natural forms of disease control as potentially safe and effective alternatives to chemical pesticides . This has led to increased efforts to develop control strategies that rely on natural predators and parasites or that involve genetically engineered microbial pest control agents . This review deals with a natural form of biological control in which the virulence of a fungal pathogen is attenuated by an endogenous viral RNA genetic element: the phenomenon of transmissible hypovirulence in the chestnut blight fungus, Cryphonectria parasitica . Recent progress in the molecular characterization of a hypovirulence-associated viral RNA has provided an emerging view of the genetic organization and basic expression strategy of this class of genetic elements . Several lines of evidence now suggest that specific hypovirulence-associated virus-encoded gene products selectively modulate the expression of subsets of fungal genes and the activity of specific regulatory pathways . The construction of an infectious cDNA clone of a hypovirulence-associated viral RNA represents a major advancement that provides exciting new opportunities for examining the molecular basis of transmissible hypovirulence and for engineering hypovirulent strains for improved biocontrol . These developments have significantly improved the prospects of using this system to identify molecular determinants of virulence and elucidate signal transduction pathways involved in pathogenic responses . In addition, novel approaches are now available for extending the application of transmissible hypovirulence for management of chestnut blight and possibly other fungal diseases.

FEMS Microbiol Rev, 1992 Dec, 9(2-4), 323 - 31
Fungal degradation of polyhydroxyalkanoates and a semiquantitative assay for screening their degradation by terrestrial fungi; Matavulj M et al.; The current problems with decreasing fossile resources and increasing environmental pollution by petrochemical-based plastics have stimulated investigations to find biosynthetic materials which are also biodegradable . Bacterial reserve materials such as polyhydroxyalkanoates (PHA) have been discovered to possess thermoplastic properties and can be synthesized from renewable resources . Poly-beta-hydroxybutyric acid (PHB) is at present the most promising PHA; and BIOPOL, its copolymer with poly-beta-hydroxy-valerate (PHV), is already industrially produced (ICI, UK), and used as packaging material (WELLA, FRG) . According to the literature, PHA degradation has so far mainly been observed in bacteria; only under certain environmental conditions has fungal degradation of PHAs been indicated . Since fungi constitute an important part of microbial populations participating in degradation processes, a simple screening method for fungal degradation of BIOPOL, a PHA-based plastic, was developed . Several media with about 150 fungal strains from different terrestrial environments and belonging to different systematic and ecological groups were used . PHA depolymerization was tested on three PHB-based media, each with 0.1% BIOPOL or PHB homopolymer causing turbidity of the medium . The media contained either a comparatively low or high content of organic carbon (beside PHA) or were based on mineral medium with PHA as the principal source of carbon . The degradation activity was detectable due to formation of a clear halo around the colony (Petri plates) or a clear zone under the colony (test tubes).(ABSTRACT TRUNCATED AT 250 WORDS)

Mol Biother, 1992 Dec, 4(4), 184 - 7
Relation between the biologic activities and chemical structures of synthetic microbial lipopeptide analogs in mice; Shimizu T et al.; Mitogenicity, lethal toxicity, and antitumor activity against Meth A fibrosarcoma of chemically synthesized lipopeptide analogs, S-{2,3-bis(palmitoyloxy)-2R-propyl}-N-{(2,2,2)-tri- chloroethoxycarbonyl: Troc group}-cysteinyl-seryl-seryl-asparaginyl-alanine (compound KAB-2), which contain the amino acid sequence of lipopeptide in Escherichia coli, S-{2,3-bis(palmitoyloxy)- 2R-propyl}-N-(Troc- or amino-group)-cysteinyl-asparaginyl-seryl-glycyl-glycine (compound KAB-14 or -20), which is found in the amino acid sequence of lipopeptide in Streptomyces, and the compounds binding one to six amino acids, were examined . The analogs showed the mitogenic activity toward splenocytes of C3H/He mice . Low concentrations (0.4 and 2.0 micrograms/ml) of compounds KAB-20 and -21, which have five and six amino acids, respectively, increased the incorporation of {3H}thymidine better than a high concentration (50 micrograms/ml), suggesting that KAB compounds carrying amino groups exert better mitogenicity than KAB compounds carrying Troc group . The decrease of amino acid number in lipopeptide analogs appears to result in a lowering of mitogenicity at low concentrations . KAB-14 and KAB-2 did not exhibit the lethality at a high dose of 50 micrograms/mouse in galactosamine-loaded C57BL/6 mice . By twice intravenous injections of 50 micrograms against Meth A fibrosarcoma in BALB/c mice, KAB-2 showed a higher inhibitory effect than KAB-14 . Based on these results, we concluded that the difference of amino acid sequence in the synthetic lipopeptides affects the potency of biologic activities.

Appl Environ Microbiol, 1992 Dec, 58(12), 3941 - 8
Gene probe analysis of soil microbial populations selected by amendment with 2,4-dichlorophenoxyacetic acid; Holben WE et al.; Soils with a history of 2,4-dichlorophenoxyacetic acid (2,4-D) treatment at field application rates and control soils with no prior exposure to 2,4-D were amended with 2,4-D in the laboratory . Before and during these treatments, the populations of 2,4-D-degrading bacteria were monitored by most-probable-number (MPN) enumeration and hybridization analyses, using probes for the tfd genes of plasmid pJP4, which encode enzymes for 2,4-D degradation . Data obtained by these alternate methods were compared . Several months after the most recent field application of 2,4-D (approximately 1 ppm), soils with a 42-year history of 2,4-D treatment did not have significantly higher numbers of 2,4-D-degrading organisms than did control soils with no prior history of treatment . In response to laboratory amendments with 2,4-D, both the previously treated soils and those with no prior history of exposure exhibited a dramatic increase in the number of 2,4-D-metabolizing organisms . The MPN data indicate a 4- to 5-log population increase after one amendment with 250 ppm of 2,4-D and ultimately a 6- to 7-log increase after four additional amendments, each with 400 ppm of 2,4-D . Similarly, when total bacterial DNA from the soil microbial community of these samples was analyzed by using a probe for the tfdA gene (2,4-D monoxygenase) or the tfdB gene (2,4-dichlorophenol hydroxylase) a dramatic increase in the level of hybridization was observed in both soils.(ABSTRACT TRUNCATED AT 250 WORDS)

Am J Obstet Gynecol, 1992 Dec, 167(6), 1588 - 94
Association of cervicovaginal infections with increased vaginal fluid phospholipase A2 activity; McGregor JA et al.; OBJECTIVE: The purpose of this study was to determine if phospholipase A2 was detectable within vaginal fluid and to correlate its presence with the presence of common lower genital tract infection or microbial conditions . STUDY DESIGN: Pregnant women were examined at the first prenatal visit with standard clinical evaluations and microbiologic cultures or tests . Vaginal fluid samples were evaluated for phospholipase A2 activity by means of a standardized enzyme fluorometric assay . Data were stratified to control for coexisting infections . RESULTS: Phospholipase A2 activity was detected among 29.8% of women and was independently associated with the presence of bacterial vaginosis (p < 0.001), Trichomonas . vaginalis (p < 0.04), and Chlamydia trachomatis (p < 0.02) . The percentage of women with phospholipase A2 activity and the level of activity was increased in the presence of more than one infection . CONCLUSIONS: Elevated reproductive tract phospholipase A2 concentrations among pregnant women may play roles in the pathogenesis of preterm labor and birth . Identification of pregnant women with increased concentrations in vaginal fluid may allow for development of effective intervention strategies to reduce the risk of preterm birth.

J Immunol, 1992 Dec 1, 149(11), 3727 - 34
Effects of cytokines from activated immune cells on vascular cell growth and HIV-1 gene expression . Implications for AIDS-Kaposi's sarcoma pathogenesis; Barillari G et al.; Kaposi's sarcoma (KS) arises more frequently in homosexual and bisexual men than in other groups of HIV-1 infected individuals . Clinico-epidemiologic data indicate that homosexuals often are infected with multiple microbial agents and/or subjected to other antigenic stimuli, preceding or accompanying HIV-1 infection . Signs of immune activation, in fact, frequently have been detected in these individuals, and the onset of KS can precede any sign of immunodeficiency . These data have suggested that products from activated immune cells may affect the development of AIDS-KS . Here we report that conditioned media from activated or dysregulated T cells contain a variety of cytokines that promote the growth of spindle cells derived from KS lesions of AIDS patients (AIDS-KS cells) and induce normal vascular cells, potential cell progenitors of the AIDS-KS cells, to acquire features of the KS cell phenotype ("spindle" cell morphology and growth responsiveness to the mitogenic effect of extracellular HIV-1 Tat protein) . The same conditioned media or cytokines promote HIV-1 gene expression and rescue defective HIV-1 proviruses, interrupting HIV-1 latency and increasing Tat production . The cellular and viral effects of cytokines are increased in an additive or synergistic manner by picomolar concentrations of extracellular Tat . These data suggest that cytokines produced by activated immune cells cooperate with HIV-1 infection in AIDS-KS pathogenesis.

Mol Pharmacol, 1992 Dec, 42(6), 982 - 90
Inhibition by HS-142-1, a novel nonpeptide atrial natriuretic peptide antagonist of microbial origin, of atrial natriuretic peptide-induced relaxation of isolated rabbit aorta through the blockade of guanylyl cyclase-linked receptors; Imura R et al.; HS-142-1, a specific nonpeptide antagonist for the atrial natriuretic peptide (ANP) receptor, equally blocked rat ANP (rANP)-, porcine brain natriuretic peptide-, or porcine C-type natriuretic peptide-stimulated GMP production in cultured bovine aortic smooth muscle (BASM) and bovine aortic endothelial (BAE) cells in a concentration-dependent fashion, at concentrations of 1-300 micrograms/ml . But, even at 300 micrograms/ml, HS-142-1 only weakly inhibited the specific binding of 125I-rANP to the BASM and BAE cells, where only a small portion of the binding sites are linked to guanylyl cyclase . Further, with BAE cell membranes, HS-142-1 recognized only the 135-kDa ANP receptor, which is thought from 125I-rANP affinity cross-linking studies to be the guanylyl cyclase-linked receptor . HS-142-1 also, if anything, inhibited the labeling of 135-kDa ANP receptors in the affinity cross-linking studies with BASM membranes, suggesting that a major portion of the 135-kDa ANP receptors are HS-142-1 insensitive and only a small portion of the 135-kDa ANP receptors are responsible for the blockade by HS-142-1 of GMP production in BASM cells . At a concentration of 100 micrograms/ml, HS-142-1 reversibly prevented ANP-induced relaxation of the isolated rabbit thoracic aorta induced to contract with 3 x 10(-7) M phenylephrine, but not the relaxation induced by sodium nitroprusside, isoproterenol, or papaverine . These results suggest that HS-142-1 specifically inhibits natriuretic peptide-induced vasorelaxation through the blockade of guanylyl cyclase-linked natriuretic peptide receptors . HS-142-1 thus will be a powerful tool for understanding the physiological roles, in vasculature, of natriuretic peptides, which contribute to the homeostasis of blood pressure and intravascular volume.

Z Ernahrungswiss, 1992 Dec, 31(4), 269 - 77
{The effect of a supplement of microbial phytase on zinc availability}; Rimbach G et al.; A study of 35 (5 x 7) male, individually housed, albino rats (initial average weight = 50 g) was undertaken to examine the effect of an addition of microbial phytase to a diet containing phytate on the availability of zinc . The rats were fed a semisynthetic diet based of egg white and cornstarch over a 3-week period . All diets were supplemented with 20 mg Zn/kg . Group I (control) was fed the basal diet free of phytic acid (PA) and phytase . By replacing cornstarch by Na-phytate (0.5% in group II and 1.0% group III), molar phytate: Zn ratios of 25 and 50:1 were obtained, respectively . In groups IV (0.5% PA) and V (1.0% PA) 1000 U of microbial phytase were added . A molar phytate:Zn ratio of 25 (group II) and 50:1 (group III) resulted in a dose-dependent depression of growth and feed efficiency ratio . These negative effects of the addition of PA could be completely counteracted by the supplementation of 1,000 U of phytase in group IV and partially so in group V . Similarly, the apparent absorption and retention of Zn, Zn-concentration in femur and testes and different Zn-status-parameters in plasma (Zn-concentration, percent unsaturated plasma-Zn binding capacity, activity of alkaline phosphatase) were improved by adding 1,000 U microbial phytase/kg diet . The present study shows that an addition of microbial phytase to phytate-rich diets considerably improves the availability of Zn in growing rats.

J Periodontol, 1992 Dec, 63(12 Suppl), 1102 - 9
DNA probe and enzyme analysis in periodontal diagnostics; Loesche WJ; Recent research in periodontology has indicated that a finite number of bacterial species are associated with periodontal disease . This has generated the hypothesis that periodontal disease is essentially an infection due to one or more of the putative periodontopathogens; i.e., the specific plaque hypothesis (SPH) . This microbial specificity paradigm has already changed the way researchers and some clinicians view periodontal disease . The clinician must heed several cautions signs, however, if he is to use the SPH to provide treatment options that could enhance the delivery of care . There are several diagnostic technologies that can be used to detect and semi-quantitate those bacterial species that have been identified as periodontopathogens . This paper discusses diagnostic tests based upon the detection in plaque of DNA segments or enzyme activity(ies) that are unique for one or more of the suspected periodontopathogens.

J Anim Sci, 1992 Dec, 70(12), 3909 - 15
Effects of supplemental protein source and alkaline hydrogen peroxide treatment of wheat straw on site of nutrient digestion and flow of nitrogenous compounds to the duodenum of steers; Sultan JI et al.; The objective of this study was to determine the effects of soybean meal (SBM) or spray-dried blood meal (BM) supplementation of diets based on untreated (UNT-WS) or alkaline hydrogen peroxide-treated wheat straw (AHP-WS) . A 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments was used . Variables included nutrient digestion and flow to the duodenum . Four Simmental steers (average weight 477 kg) fitted with ruminal and duodenal cannulas were fed 65% UNT-WS or AHP-WS based diets in 12 equal portions daily . Diets were formulated to contain 10% CP . Chromic oxide was used as the digesta flow marker and purines were used as the microbial marker . There were no straw type x protein source interactions . Total tract and ruminal OM digestibility were approximately 25% greater (P < .04) when AHP-WS was fed than when UNT-WS was fed . Source of protein did not affect (P > .10) OM or fiber digestion in the rumen or total tract . Ruminal digestion of NDF and ADF was increased (P < .01) by 51 and 40%, respectively, when AHP-WS was fed than when UNT-WS was fed . Main effect means (P > .10) for N flow to the duodenum as a percentage of N intake were 128.2, 142.5, 133.4, and 137.6 for UNT-WS, AHP-WS, SBM, and BM treatments, respectively . Despite increased (P < .01) ruminal OM digestion for AHP-WS, microbial N flow to the duodenum was greater (P < .01) when UNT-WS was fed than when APH-WS was fed.(ABSTRACT TRUNCATED AT 250 WORDS)

J Exp Anim Sci, 1992 Dec, 35(3), 110 - 9
Changes in colonic mucins of germfree rats in response to the introduction of a "normal" rat microbial flora . Rat colonic mucin; Enss ML et al.; In order to determine the influence of bacterial colonization on amount and composition of colonic mucins, germfree male AS/Ztm rats were colonized with a rat specific intestinal flora for different times (2, 7, 14, 21, 28, 35, 120 days) . The amount of colonic mucins was determined by gel filtration on Sepharose CL-4B; the relative amount of acidic mucins was calculated after ion exchange chromatography . In addition, cecal weight and dry matter of feces were monitored . While germfree and SPF rats revealed similar amounts of colonic mucins (7.0 vs . 7.2 mg mucin/300 g body weight), the initial phase of association was characterized by considerably decreasing values . After four weeks of association, the total amount of colonic mucins had almost equalized in the two groups . The amount of acidic mucins, having decreased during the first three weeks of colonization, rendered values comparable to the SPF mucins after four months of adaptation . Cecomegaly in germfree rats disappeared within the first two days, while solidification of the intestinal content occurred within four months . Mucin losses during initial phase of association are attributed 1 . to the disappearance of the cecal mucin pool, and 2 . to the mucin degrading activity of some bacterial strains known to be present in the intestinal flora . Further development is conducted by a stimulation of mucin secretion, described to follow the colonization . The initially increased secretion of neutral mucins is attributed to a pronounced release of immature mucin glycoproteins, while the shift to more acidic mucins is considered to result from stimulated secretion as well as from a selective bacterial degradation of neutral mucin components.

Clin Lab Med, 1992 Dec, 12(4), 787 - 803
Inactivation of microbial contaminants of blood components; AuBuchon JP et al.; Despite the low risk of transfusion-transmitted infection currently present in the blood supply, processes to inactivate contaminating viruses and bacteria may improve the safety of transfusion even further . A variety of techniques, using both physical and chemical processes, are being explored . Particularly promising is adaptation of the solvent/detergent technique (already in use for plasma derivatives) to plasma for transfusion . Inactivation of viruses in cellular components may require a combination of techniques, possibly including leukocyte depletion filtration, photoactive compounds, and subsequent washing . Concerns about potential toxicity of the agents employed and retention of component efficacy after treatment and storage remain unresolved, however.

Ugeskr Laeger, 1992 Nov 30, 154(49), 3510 - 1
{Pseudomonas bacteremia developing after whirlpool bath}; Hojbjerg T et al.; Whirlpools may be responsible for transmission of microbial infections among the bathers if the technical hygienic conditions in the care of the bath are not observed . Two cases of infection with Pneudomonas bacteria were observed after use of whirlpools in a deluxe summer chalet . On the basis of the documented cases, the necessity for specific requirements concerning the installation, running and control of whirlpools used commercially should be considered . In their advisory brochures, the responsible authorities should ensure that the requirements made concerning whirlpools should be intensified so that these baths in summer chalets which are rented out should be subject to public control . Owners and users of whirlpools should be aware of the importance of meticulous hygiene in their care.

Clin Infect Dis, 1992 Nov, 15 Suppl 1, S5 - 32
General guidelines for the clinical evaluation of anti-infective drug products . Infectious Diseases Society of America and the Food and Drug Administration; Beam TR Jr et al.; This document provides new general guidelines for the design and execution of studies evaluating anti-infective drugs for the prevention or treatment of infectious diseases . The first step in evaluation is the determination of in vitro microbial susceptibility . Next, studies are conducted in animals . Several animal models provide information useful in the prediction of appropriate dosing and activity in humans . If the results of these studies are favorable, staged clinical trials are then conducted . These guidelines reflect changes in the practice of medicine, dealing with topics such as the switch from parenteral to oral drug administration during a course of therapy, treatment in settings other than acute-care hospitals, and the use of alternative comparison drugs for the study of indications or dosing schedules not covered by the product label . Because further changes in practice are anticipated, the present guidelines will need to be updated and revised periodically.

Prikl Biokhim Mikrobiol, 1992 Nov-Dec, 28(6), 803 - 17
{Enzymatic reactions in biotechnology (48th Bach lecture)}; Bezborodov AM; The paper is the 48th Bach Lecture presented under the same title . It covers the biochemical mechanisms of the biogenesis of microbial biosynthetic products, role of acetyl-CoA, function of the succinate-glycine cycle, reactions of the hexose-monophosphate pathway of carbon metabolism . The reversible action of hydrolases in enzymatic catalysis and degradation of xenobiotics are discussed . The data on redox reactions are pooled . Such modern biotechnological processes as epoxidation, synthesis of acrylamide and some monomers involved in chemical syntheses of polymers, synthesis of oligosaccharide and fluorine-containing amino acids are considered . Promising commercial applications of biocatalysis are discussed.

J Exp Biol, 1992 Nov, 172, 179 - 92
V-ATPases in phagocytic cells; Grinstein S et al.; V-ATPases in phagocytic cells are known to mediate the acidification of most intracellular organelles . Proton-pump-mediated acidification of these organellar compartments is vital to numerous cell processes, including receptor recycling, protein processing and sorting and microbial degradation . Recent studies have suggested a role for V-ATPases in cytoplasmic pH homeostasis . The present discussion will review the current knowledge regarding the presence of V-ATPases in both the plasmalemmal and organellar membranes of phagocytic cells, the regulation of proton pump activity in these locations and the functional significance of pump-mediated proton translocation.

Clin Exp Dermatol, 1992 Nov, 17(6), 463 - 5
Distal phalangeal metastasis of a chondrosarcoma presenting initially as bilateral onycholysis; Lambert D et al.; Onycholysis is the detachment of a nail plate from its distolateral attachments . There are numerous aetiologies: congenital, traumatic, microbial, toxic, dermatological, systemic and benign or malignant tumours . We report a case with onycholysis of the ring-fingers of both hands whose symmetrical and bilateral characteristics temporarily confused the diagnosis.

Nutrition, 1992 Nov-Dec, 8(6), 412 - 7
Fine-bore peripheral catheters versus central venous catheters for delivery of intravenous nutrition; Kohlhardt SR et al.; We present a descriptive study of 229 consecutive inpatients requiring intravenous nutrition . These patients received either complete peripheral intravenous nutrition via a fine-bore silicone catheter (n = 80) or short Teflon catheter (n = 15) or received conventional central intravenous nutrition (n = 134) . Nutrient delivery was similar for both systems, providing 0.2-0.4 g N.kg-1 x day-1 and 0.13-0.15 mJ.kg-1 x day-1 from preparations containing 4.3 MJ/L total energy (65-75% lipid: 25-35% glucose for peripheral support and 100% glucose for central delivery) with 6 g N/L . We compared the incidence of catheter complication and the probability of catheter function over time for the peripheral and conventional central systems . Venous access complications were seen only with central venous catheterization (10.4%) . Chemical phlebitis occurred in 17% of fine-bore catheters and 91.4% of Teflon catheters . The infective phlebitis rate of fine-bore silicone catheters was 1.02% and daily risk of phlebitis 0.016%, with no instance of device-related bacteremia or sepsis . Central-line microbial contamination (21.7%) and catheter-related sepsis (3%) were significantly greater (p < 0.0005, chi 2 goodness-of-fit test) than with fine-bore silicone and Teflon catheters . The probability of complication-free function against time was similar (0.75 < p < 0.90, log-rank test) in fine-bore silicone catheters and central venous catheters . We conclude that fine-bore silicone catheters provide long-term phlebitis-free delivery of complete peripheral intravenous nutrition.

J Antibiot (Tokyo), 1992 Nov, 45(11), 1746 - 52
Epoxomicin, a new antitumor agent of microbial origin; Hanada M et al.; An actinomycete strain No . Q996-17 produced a novel compound, epoxomicin, which exhibited in vivo antitumor activity against B16 melanoma . Structural studies indicated that it is a new member of the epoxy-beta-aminoketone group, and is closely related to eponemycin.

J Dairy Sci, 1992 Nov, 75(11), 3084 - 90
Effect of microbial inoculant on quality of alfalfa hay baled at high moisture and lamb performance; Emanuele SM et al.; The effectiveness of a microbial hay inoculant in high moisture alfalfa hay was evaluated . Alfalfa (third cutting) was baled at 72% DM without or with inoculant and at 82% DM without inoculant during yr 1 . In yr 2, alfalfa (second cutting) was baled at 75% DM without or with inoculant and at 82% DM without inoculant . Application rate of inoculant was 3.8 L/.98 tonne each year . At this application rate, 90 billion cfu were applied per .98 tonne of forage . Hays were core sampled at 0, 14, 30, and 60 d after baling to determine chemical composition . By d 30, all hays had DM content of 89% . In yr 2, 12 wether lambs were assigned to three treatments in a replicated 3 x 3 Latin square . Treatments were chopped, low moisture hay plus corn; chopped, inoculated high moisture hay plus corn; and chopped, high moisture hay plus corn . All diets contained 63% alfalfa hay, 35% ground corn, and 2% minerals and vitamins . In yr 1, inoculated and low moisture hays were not different in chemical composition but were higher in CP and lower in NDF than high moisture hay . Neither NDF nor CP were different among the three hays in yr 2 . Average daily gain was not different on the three diets . The feed to gain ratio was lowest for the inoculated hay, intermediate for the low moisture hay, and highest for the high moisture hay diet . Daily gain and feed to gain ratio were not different for lambs fed the inoculated hay baled at 75% DM compared with lambs fed untreated hay baled at 82% DM.

Int J Microcirc Clin Exp, 1992 Nov, 11(4), 383 - 401
Circulatory adaptation to the increased metabolism in the skin at the site of the tuberculin reaction; Abbot NC et al.; The sequence of changes at the site of a positive tuberculin test response were studied in 19 healthy young adults who had been immunised with BCG in childhood . The development of erythema preceded that of induration and both were most intense at 48-72 h . The strongest reactions showed higher laser Doppler (LD) flux at the periphery than at the center (central relative slowing) . All showed a substantial reduction in steady-state (ss) tcpO2 from 24 h onwards and the oxygen consumption rate (mlO2.kg-1.min-1), calculated from the rate of fall in tcpO2 during temporary cuff occlusion of arterial input, was raised (greater than two-fold) throughout the period of study (to 96 h) . The density of lymphocytes and macrophages in the inflammatory infiltrate in the dermis was related to the fall in tcpO2.ss and to the extent of thickening of the dermis . These experiments showed that the previously healthy dermal microcirculation can adapt to temporary increase in metabolic demands of leucocytes emigrated from the circulation into the tissue: in intense delayed hypersensitivity (DHS) reactions there is considerable hypoxia and respiratory debt, but maintenance of viability in the short-term . It is likely that similar adaptations occur in the period of establishment of microbial infection.

Arch Ophthalmol, 1992 Nov, 110(11), 1559 - 62
Risks of keratitis and patterns of use with disposable contact lenses; Matthews TD et al.; Disposable soft contact lenses have been marketed as a safer alternative to conventional soft lenses . We undertook a case-control study of patients attending the casualty unit of an eye hospital to quantify the relative risk of keratitis in disposable lens wear and to establish associated patterns of use . All eligible contact lens users were identified and asked to complete a questionnaire (n=242) . Keratitis, microbial or sterile, was the most common complication in disposable lens users, occurring in 16 of 41 subjects . The relative risks for all lens types were estimated by comparison with rigid lenses (the referent) . Both extended- and daily-wear disposable lenses were associated with higher risks of keratitis than other lens types including conventional extended-wear lenses . Poor hygiene, disinfectant system failure, and lens type may all account for these statistically significant trends.

J Am Vet Med Assoc, 1992 Nov 1, 201(9), 1404 - 6
Mycoplasma mycoides subspecies mycoides as the cause of a subauricular abscess and mastitis in a goat; Blikslager AT et al.; A 6-year-old female goat was admitted with right-sided subauricular swelling and facial nerve paralysis . Mastitis developed subsequently . The subauricular swelling localized to a mass and was excised . Mycoplasma mycoides subsp mycoides was cultured from samples obtained from the mass and mammary gland . After clinical improvement, the goat was discharged to the owner with instructions to isolate the goat and to submit milk samples from the rest of the herd for microbial culturing . Mycoplasma spp can spread to other tissues from an initial site of infection . In goats with clinical signs similar to those of the goat of this report, samples should be obtained for microbial culture on Mycoplasma medium . Goats infected with Mycoplasma spp should be isolated or culled because of the risk of transmission to uninfected animals.

Fertil Steril, 1992 Nov, 58(5), 1046 - 55
Differentiation of round cells in semen by means of monoclonal antibodies and relationship with male fertility; Eggert-Kruse W et al.; OBJECTIVE: To differentiate round cells in semen samples of subfertile men and evaluate the clinical significance during infertility investigation . PATIENTS: One hundred and eight randomly chosen couples with a median duration of infertility of 4 (range, 1 to 20) years presenting at the outpatient infertility clinic of the University of Heidelberg, Germany . MAIN OUTCOME MEASURES: Differentiation of round cells in semen by means of monoclonal antibodies (mABs) and a streptavidin-biotin system for staining . Correlation of results with medical history, outcome of clinical examination, sperm analysis, microbial screening of both partners, evaluation of sperm functional capacity in vivo by means of the postcoital test (PCT) and in vitro with the standardized crossed sperm-cervical mucus penetration test (SCMPT) and the subsequent fertility in a prospective study . RESULTS: The method used for differentiation of round cells proved to be practical and suitable for routine use . The percentage of leukocytes ranged from 0% to 58% with a median of 3% . Number of round cells and percentage of leukocytes did not differ markedly with regard to andrologic history, clinical findings, for example, varicocele, results of standard sperm analysis, and microbial colonization of semen samples . However, high rates of leukocytes of the round cells correlated with reduced sperm count and morphology and results of PCT . Leukocyte-positive (> 15% leukocytes) specimens were also significantly more frequent in case of inadequate SCMPT and reduced sperm penetration ability in vitro . CONCLUSIONS: In asymptomatic patients (in terms of genital tract infection), the majority of round cells consist of immature germ cells and < 5% are white blood cells . The streptavidin-biotin system and the mABs used in this study proved to be useful to identify patients with elevated rates of leukocytes in semen possibly reflecting subclinical genital tract infection with influence on sperm functional capacity and subsequent fertility . Thus the procedure can be recommended to be included in a comprehensive evaluation of male fertility.

J Steroid Biochem Mol Biol, 1992 Nov, 43(6), 543 - 7
Bioconversion of steroids by Cochliobolus lunatus--II . 11 beta-hydroxylation of 17 alpha, 21-dihydroxypregna-1,4-diene-3,20-dione 17-acetate in dependence of the inducer structure; Undisz K et al.; The 11 beta-hydroxylase of the filamentous fungus Cochliobolus lunatus m 118 was induced with the substrate 17 alpha, 21-dihydroxypregna-1,4-diene-3,20-dione 17-acetate (11 beta-deoxyprednisolone 17-acetate) itself, substrate analogues, different pregnane compounds, sterols, intermediates of microbial sterol side-chain degradation or bile acids, together with 24 different steroids in a standardized test system . The resulting 11 beta-hydroxylation rate, leading to prednisolone 17-acetate and prednisolone, respectively, was determined and compared with the hydroxylation rate of non-induced cultures . The transformation yield strongly depended on the inducer structure . The microbial sterol side-chain degradation intermediates (20S)-20-hydroxymethylpregn-4-en-3-one and the corresponding pregna-1,4-diene compound caused the highest induction effects (induction factors 5.1 and 4.9, respectively) . The metabolism of (20S)-20-hydroxymethylpregna-1,4-dien-3-one during the cultivation was elucidated . The induction effect decreased with the rising oxidation of the inducer . The significant increase of the 11 beta-hydroxylation rate of 1-dehydro-pregnane substrates by specific induction allows alternative pathways to glucocorticoid partial syntheses.

J Virol, 1992 Nov, 66(11), 6721 - 7
Coexpression of the simian immunodeficiency virus Env and Rev proteins by a recombinant human adenovirus host range mutant; Cheng SM et al.; Recombinant human adenoviruses (Ads) that replicate in the intestinal tract offer a novel, yet practical, means of immunoprophylaxis against a wide variety of viral and bacterial pathogens . For some infectious agents such as human immunodeficiency virus (HIV), the potential for residual infectious material in vaccine preparations must be eliminated . Therefore, recombinant human Ads that express noninfectious HIV or other microbial proteins are attractive vaccine candidates . To test such an approach for HIV, we chose an experimental model of AIDS based on simian immunodeficiency virus (SIV) infection of macaques . Our data demonstrate that the SIV Env gene products are expressed in cultured cells after infection with a recombinant Ad containing both SIV env and rev genes . An E3 deletion vector derived from a mutant of human Ad serotype 5 that efficiently replicates in both human and monkey cells was used to bypass the usual host range restriction of Ad infection . In addition, we show that the SIV rev gene is properly spliced from a single SIV subgenomic DNA fragment and that the Rev protein is expressed in recombinant Ad-SIV-infected human as well as monkey cells . The expression of SIV gene products in suitable live Ad vectors provides an excellent system for studying the regulation of SIV gene expression in cultured cells and evaluating the immunogenicity and protective efficacy of SIV proteins in macaques.

Biotechnol Prog, 1992 Nov-Dec, 8(6), 514 - 20
The use of pressure to modify enzyme activity in reversed micelles; Rao AM et al.; Pressurization of enzyme-containing AOT-water-isooctane reversed micelles with low molecular weight gases leads to markedly different responses in activity characteristics . Microbial lipases exhibit a total cutoff in activity with as low a pressure as 2 MPa and a remarkable activity regain with depressurization . The observation also holds for reaction in monophasic organic solvents . The protease, alpha-chymotrypsin, is unaffected by pressurization until a critical pressure wherein micellar instability occurs . The use of pressure as a switch for lipase reaction in nonaqueous media is discussed.

Enzyme Microb Technol, 1992 Nov, 14(11), 911 - 6
Resolution of 4-amino-cyclopentanecarboxylic acid methyl esters using hydrolytic enzymes; Mahmoudian M et al.; A number of esterases (EC 3.1.1.1) and lipases (EC 3.1.1.3) of microbial and mammalian origin were screened for the ability to resolve racemic 4-amino-cyclopentanecarboxylic acid methyl ester derivatives as potential intermediates in the production of carbocyclic nucleosides . Surprisingly, functionalization of the remote amino group had a profound effect on both the rate and enantioselectivity of hydrolysis of the methyl ester . 4-(Benzoylamino)-2-cyclopentenecarboxylic acid, methyl ester (V) with pig liver esterase gave the highest enantioselectivity . The residual ester, which was of the correct absolute stereochemistry {(+) 1S, 4R} for carbocyclic nucleoside synthesis, could be obtained in high optical purity . Optimization of pH, solvent type, and concentration improved the enantioselectivity of the process by a further twofold.

Trends Biotechnol, 1992 Nov, 10(11), 402 - 8
Enzymatic synthesis of acrylamide: a success story not yet over; Kobayashi M et al.; The application of enzymatic transformations is attracting increasing attention . Until recently, such an approach has generally been confined to producing fine chemicals difficult to obtain through conventional chemical methods . Microbial nitrile hydratase (NHase) has now been applied to the industrial, kiloton-scale production of the important chemical commodity acrylamide . Recent progress in understanding microbial nitrile metabolism at both the gene and protein levels is permitting improvement of the acrylamide production process.

Drug Metab Dispos, 1992 Nov-Dec, 20(6), 882 - 8
Microbial models of mammalian metabolism . N-dealkylation of furosemide to yield the mammalian metabolite CSA using Cunninghamella elegans; Hezari M et al.; Furosemide (Lasix), a widely used diuretic, is metabolized by the fungus Cunninghamella elegans (ATCC 36112) to 4-chloro-5-sulfamoyl anthranilic acid (CSA), a metabolite also present in mammalian systems . This metabolite was isolated following preparative-scale incubations of C . elegans, and was characterized by comparison with standard CSA using 13C-NMR, mass spectrometry (high-resolution mass spectra, electron impact mass spectra), UV, TLC, and HPLC with fluorescence detection . Because a known complication with furosemide studies is the spontaneous formation of CSA by decomposition of furosemide during incubation, extraction, and/or analysis, a time course study was conducted to determine the rate of CSA formation caused by metabolism vs . the relatively low rate of CSA formation caused by spontaneous decomposition.

Pediatr Med Chir, 1992 Nov-Dec, 14(6), 571 - 5
{Role of "leukocyte adhesion molecules" in early periodontal disease}; Vierucci S; The purpose of this paper is to focus on functional characteristics of leukocyte adhesion molecules, on their localization and specific ligands . In fact, leukocyte chemotaxis and adhesion to endothelium is an essential step in promoting adequate immune response to bacterial infections . Since periodontal health is highly dependent on neutrophil function against the microbial dental plaque, defects in chemotaxis and adhesion of leukocytes to endothelium often result in severe, early onset periodontitis . Furthermore, oral lesions may be the only clinical manifestation of neutrophil impairment.

Acta Cytol, 1992 Nov-Dec, 36(6), 900 - 4
Phenotypic analysis of bronchoalveolar lavage lymphocytes from acquired immunodeficiency patients with and without Pneumocystis carinii pneumonia; Guzman J et al.; A study was performed to reveal possible differences in lymphocyte subpopulations from bronchoalveolar lavage (BAL) of acquired immunodeficiency patients with and without Pneumocystis carinii pneumonia . Forty-one consecutive human immunodeficiency virus-seropositive patients were studied . Pneumocystis carinii infection was detected in the BAL fluid from 18 patients . The BAL lymphocyte subpopulations were determined by surface marker analysis with the immunoperoxidase slide assay . No significant differences in the percentage of CD4+ and CD8+ lymphocytes were found between the two groups . The percentage of CD57+ natural killer (NK) cells was significantly higher in the Pneumocystis carinii-negative group than in the -positive group . Since NK cells protect from microbial infections, it is conceivable that the loss of CD57+ NK cells may be one of the phenomena leading to the immunodeficiency state that underlies the pulmonary complications characteristic of the acquired immunodeficiency syndrome.

Am J Obstet Gynecol, 1992 Nov, 167(5), 1231 - 42
Evaluation of rapid diagnostic tests in the detection of microbial invasion of the amniotic cavity; Coultrip LL et al.; OBJECTIVE: We sought to determine and compare the value of several rapid diagnostic tests in the detection of intraamniotic infection . STUDY DESIGN: Gram stain, intraamniotic glucose level determination, leukocyte esterase assay, and the Limulus amebocyte lysate assay were performed on 144 amniotic fluid specimens retrieved by transabdominal amniocentesis in 136 patients with preterm premature rupture of the membranes or preterm labor . Diagnostic indices for a positive amniotic fluid culture and the development of clinical infection were calculated for each rapid test . Receiver-operator characteristic curves were generated to help select the optimal glucose level and combination of tests to detect intraamniotic infection . RESULTS: The greatest sensitivity for predicting either a positive culture or subsequent clinical infection in preterm labor patients and in predicting clinical infection in patients with preterm premature rupture of the membranes was demonstrated by a low glucose level . The Gram stain provided the greatest positive predictive value in patients with preterm labor . Combining the Gram stain and measurement of intraamniotic glucose levels did not improve sensitivity above glucose alone or positive predictive value above Gram stain alone . CONCLUSION: Leukocyte esterase determination and Limulus amebocyte lysate assay are insensitive indicators of intraamniotic infection . Selection of Gram stain or glucose level measurement alone or in combination as an appropriate screen for intraamniotic infection will depend on the clinicians' false-positive rate threshold.

J Chromatogr, 1992 Oct 30, 624(1-2), 195 - 209
Chromatographic methods for tetracycline analysis in foods; Barker SA et al.; The tetracyclines have served for decades as an important class of antibiotics in food animal health and production . As such, they have also been a source of concern for residue monitoring authorities around the world . In response to this concern a number of microbial inhibition, immunoassay and bacterial receptor methods have evolved for the detection of this class of compounds in various foods of animal origin . However, these methods often lack specificity and are subject to false positive and false negative results . For these reasons a number of chromatographic methods for the separation and determination of the tetracyclines isolated from foods have been developed that are capable of identifying and quantifying individual tetracycline drugs . We present here an overview of tetracycline analytical methods, including microbial inhibition, immunoassay and receptor technologies for detection, techniques for isolation from food matrices, and thin-layer chromatographic, high-performance liquid chromatographic, gas chromatographic and mass spectrometric procedures for determination of this class of compounds . A discussion of the variables involved in such methodology and a review of method criteria are offered.

FEBS Lett, 1992 Oct 26, 311(3), 281 - 4
Structural relationship between lipases and peptidases of the prolyl oligopeptidase family; Polgar L; In prolyl oligopeptidase and its homologues, which constitute a new serine protease family, the order of the catalytic Ser and His residues in the amino acid sequence is the reverse of what is found in the trypsin and subtilisin families . The exact position of the third member of the catalytic triad, an Asp residue, has not yet been identified in the new family . Recent determination of the three-dimensional structures of pancreatic and microbial lipases has shown that the order of their catalytic residues is Ser, Asp, His, and this fits the order Ser, His of prolyl oligopeptidase . However, there is no sequence homology between lipases and peptidases, except for a 10-residue segment, which encompasses the essential Ser, and for the immediate vicinity of the catalytic Asp and His residues . This comparison identifies the catalytic Asp residue in the prolyl oligopeptidase family . The relative positions of the three catalytic residues in peptidases and microbial lipases were the same and this indicated structural and possibly evolutionary relationship between the two families.

Biochim Biophys Acta, 1992 Oct 20, 1132(3), 290 - 6
Regulation of translation and proteolysis during the development of embryonic dorso-ventral polarity in Drosophila . Homology of easter proteinase with Limulus proclotting enzyme and translational activation of Toll receptor synthesis; Gay NJ et al.; The generation of dorso-ventral polarity during Drosophila embryogenesis is regulated by the action of 12 maternally expressed gene products, the dorsal group . These products act together to form a dorso-ventral nuclear gradient of the transcription factor dorsal . At least three of the dorsal group genes (snake, easter and gastrulation defective) encode secreted serine proteinases which probably function during early development in the perivitelline compartment of the embryo . Here, we report that the easter proteinase is homologous in its light chain sequence to the haemocyte proclotting enzyme (PCE) of the Japanese horseshoe crab Tachypleus tridentatus . PCE is the terminal member of a proteolytic cascade activated in response to microbial polysaccharides and acts to cleave coagulogen, an invertebrate equivalent of fibrinogen . On the basis of this homology we are able to predict with confidence the overall primary structure of the easter proteinase, its mode of activation and its substrate specificity . The result also suggests that easter functions zygotically in haemocytes in a Drosophila defence response analogous to that found in Tachypleus . We also show here that the Toll receptor protein is absent in early cleavage embryos but accumulates rapidly at the syncitial blastoderm stage, the developmental stage at which its function is required . This finding suggests that translation of Toll mRNA is regulated in response to fertilisation and egg deposition . These two observations are consistent with a model of dorso-ventral pattern formation in which a proteolytic cascade is activated uniformly in the perivitelline compartment of the embryo and causes the release of ventrally localised ligands of the Toll receptor . A possible alternative model in which a proteolytic cascade is activated in response to a ventrally restricted signal is also discussed.

J Clin Invest, 1992 Oct, 90(4), 1558 - 67
Myasthenia gravis . CD4+ T epitopes on the embryonic gamma subunit of human muscle acetylcholine receptor; Protti MP et al.; In myasthenia gravis (MG) an autoimmune response against muscle acetylcholine receptor (AChR) occurs . Embryonic muscle AChR contains a gamma subunit, substituted in adult muscle by a homologous epsilon subunit . Antibodies and CD4+ cells specific for embryonic AChR have been demonstrated in MG patients . We identified sequence segments of the human gamma subunit forming epitopes recognized by four embryonic AChR-specific CD4+ T cell lines, propagated from MG patients' blood by stimulation with synthetic peptides corresponding to the human gamma subunit sequence . Each line had an individual epitope repertoire, but two 20-residue sequence regions were recognized by three lines of different HLA haplotype . Most T epitope sequences were highly diverged between the gamma and the other AChR subunits, confirming the specificity of the T cells for embryonic AChR . These T cells may have been sensitized against AChR expressed by a tissue other than innervated skeletal muscle, possibly the thymus, which expresses an embryonic muscle AChR-like protein, containing a gamma subunit . Several sequence segments forming T epitopes are similar to regions of microbial and/or mammalian proteins unrelated to the AChR . These findings are consistent with the possibility that T cell cross-reactivity between unrelated proteins ("molecular mimicry"), proposed as a cause of autoimmune responses, is not a rare event.

Math Biosci, 1992 Oct, 111(2), 295 - 313
The growth of pure and simple microbial competitors in a moving distributed medium; Kung CM et al.; The dynamics of pure and simple competition between two microbial species are examined for the case of interaction arising in a distributed and nonstagnant environment . The environment is modeled as a tubular reactor . It is shown that for relatively small values of the dispersion coefficient (i.e., for small, but nonzero, backmixing of the medium), the two competing populations can coexist in a stable steady state . It has been assumed that the species grow uninhibited and that if there are maintenance requirements they are satisfied from endogenous sources . From numerical studies it has been found that a necessary condition for coexistence is that the net specific growth rate curves of the two competitors cross each other at a positive value of the concentration of the rate-limiting substrate . The model equations have been numerically solved by using the methods of orthogonal and spline collocation.

J Antibiot (Tokyo), 1992 Oct, 45(10), 1626 - 32
Inhibition of acyl-CoA: cholesterol acyltransferase activity by cyclodepsipeptide antibiotics; Tomoda H et al.; The effect was studied of the fungal cyclodepsipeptide antibiotics beauvericin and seven distinct enniatins on acyl-CoA: cholesterol acyltransferase (ACAT) activity . In an enzyme assay using rat liver microsomes, all the compounds were found to inhibit ACAT activity . The drug concentration that caused 50% inhibition (IC50 value) of the enzyme activity was determined to be 3.0 microM for beauvericin, indicating that the compound is one of the most potent ACAT inhibitors of microbial origin . Enniatins exhibited much higher IC50 values of 22 to 110 microM . More hydrophobic enniatins showed more potent inhibitory activity . Furthermore, the ACAT inhibitory activity was evaluated as inhibition of cholesteryl ester formation in a cell assay using J774 macrophages . Calculation of the ratio, CD50 value (the drug concentration causing 50% cell damage)/IC50 value of cholesteryl ester formation, indicated that beauvericin shows the highest specificity . These data indicate that beauvericin is one of the most potent and specific ACAT inhibitors of microbial origin.

Chem Pharm Bull (Tokyo), 1992 Oct, 40(10), 2749 - 52
Phenolic constituents in Erythrina x bidwilli and their activity against oral microbial organisms; Iinuma M et al.; Five flavonoid compounds, including two new isoflavanones, were isolated from the root bark of Erythrina x bidwilli . Their structures were determined to be 2,10-di(gamma,gamma-dimethylallyl)-3,9-dihydroxypterocarpan (erythrabyssin II), 6,8-di(gamma,gamma-dimethylallyl)-7,2',4'-trihydroxyisoflavanone (bidwillon A), 8-gamma,gamma-dimethylallyl-2',4'-dihydroxy-{6",6"-di-methylpyrano - (2",3":7,6)}isoflavanone (bidwillon B), 8-gamma,gamma-dimethylallyl-7,4'-dihydroxyisoflavone (8-gamma,gamma-dimethyl-allyldaidzein), and 8-gamma,gamma-dimethylallyl-5,2',4'-trihydroxy-{6",6"-dimethylpyrano+ ++- (2",3":7,6)}isoflavone (auriculatin), by means of spectroscopic analysis . Some potent activities against oral microbial organisms (Fusobacterium nucleatum and Prevotella intermedia) were shown in these flavonoid compounds.

Klin Monatsbl Augenheilkd, 1992 Oct, 201(4), 231 - 3
{Persistence and transient conjunctival pathogen colonization before planned intraocular interventions}; Rummelt V et al.; The risk of a postoperative endophthalmitis is influenced by the presence of a significant bacterial colonisation of the conjunctiva before intraocular surgery . Between February and August 1990 we performed conjunctival smears in 481 patients 1) on the eve of the operation and 2) just before planned intraocular surgery, to evaluate a persistent or transient microbial colonisation of the conjunctiva . 352 patients showed insignificant ("negative") and 129 patients a significant ("positive") bacterial growth in the first conjunctival smear . 96% of the patients (n = 336) had a negative result in both smears . 30% of the patients (n = 37) with a positive conjunctival smear showed a persisting bacterial colonisation, whereas 70% of the patients (n = 92) had a transient colonisation of the conjunctiva with a negative second smear . As a persisting microbial colonisation of the conjunctiva may be an important factor for the development of postoperative endophthalmitis, we recommend prophylactic conjunctival smears before surgery to diminish the risk of intraocular infections after surgery.

Vet Immunol Immunopathol, 1992 Oct, 34(1-2), 127 - 38
Identification and characterization of rat intestinal lamina propria cells: consequences of microbial colonization; Woolverton CJ et al.; Germ-free (GF) animals exhibit an abnormally diminished, cell-mediated immune response which can be rapidly normalized by bacterial colonization of the intestine . This conventionalization suggests that the development and/or regulation of the immune system is dependent upon intestinal bacteria or their products . Here we consider the ontogeny of gut-associated lymphoid tissue (GALT) immunocytes by isolating and characterizing the intestinal lamina propria cells (LPC) of GF rats responding to bacterial colonization or an irrelevant protein antigen, and compared to LPC of specific pathogen-free (SPF) rats which were conventionalized (CV) from birth . Isolation of cells was accomplished by successive EDTA washings of small intestine to remove the epithelium, and enzymatic digestion of the tissue generating single-cell suspensions . Resulting cell suspensions were characterized by monoclonal antibodies directed against leukocyte epitopes using flow cytometry . Functional characterization was measured by the tritiated thymidine proliferation assay with concanavalin A (Con A) and lipopolysaccharide (LPS) as co-stimulators . Germ-free and SPF rats had fewer total LPC than CV rats . Antibody staining revealed that GF rats had fewer total leukocytes than CV and SPF rats, and that CV rats had a greater percentage of T-cells and cells positive for the C3 receptor than GF rats . Co-stimulation of LPC with mitogens only increased proliferation of cells from CV rats compared to GF and SPF rats . In addition, spleen cells from CV rats demonstrated significantly enhanced proliferative responses compared to spleen cells from GF rat and were more analogous to spleen cells from SPF rats in their ability to proliferate in vitro, with and without mitogens . We conclude that T-cells and CD35-positive (C3BR+) cells are recruited and/or proliferate in response to intestinal bacteria and/or their products, and that this results in the induction of immune competency.

Oncol Nurs Forum, 1992 Oct, 19(9), 1337 - 42
Management of neutropenic enterocolitis in the patient with cancer; Smith LH et al.; Neutropenic enterocolitis is a life-threatening condition often seen in patients experiencing prolonged periods of neutropenia from conditions such as leukemia and lymphoma and from aggressive chemotherapy regimens . Its exact pathologic process remains unclear; however, it has been proposed that direct cytotoxic damage occurs to the bowel mucosa with subsequent microbial invasion complicated by the lack of adequate neutrophil response . The damage may progress to bowel perforation and septic shock . Early recognition and management by healthcare team members are crucial for the improved prognosis of these individuals . Controversy continues to exist concerning management options and the timing of these interventions . This article outlines nursing and medical management of the patient with neutropenic enterocolitis.

J Anim Sci, 1992 Oct, 70(10), 3238 - 47
Manipulation of amino acid supply to the growing ruminant; Merchen NR et al.; Quality of protein (indicated by amino acid {AA} composition) that enters the small intestine (SI) of growing ruminants is dictated largely by the AA composition of microbial protein . The AA supply is well-balanced and, although individual AA can be experimentally determined to be first- or second-limiting, it seems that several AA (sulfur AA, lysine, histidine, and possibly threonine, valine, and isoleucine) may be colimiting in many circumstances . Quality of the postruminal AA supply can be altered by increasing (maximizing) net microbial protein synthesis, manipulating supplemental protein source, or feeding ruminally protected AA . Defaunating the rumen increases postruminal AA supply by increasing flow of both bacterial and nonbacterial AA . Defaunation has little effect on proportions of individual AA entering the SI . Different feed proteins vary greatly in the quantity of individual AA that they supply for absorption from the SI . Most proteins are a poor source of at least one essential AA; feeding combinations of proteins may be the most practical approach to supplying AA in optimal proportions . Feeding individual ruminally protected AA can alter the profile of AA reaching the SI, but work is needed to identify dietary conditions under which use of such products will be most beneficial.

J Anim Sci, 1992 Oct, 70(10), 3223 - 33
Quantification of intraruminal recycling of microbial nitrogen using nitrogen-15; Firkins JL et al.; Studies were done to derive a technique to quantify intraruminal recycling of microbial nonammonia nitrogen (NAN) . After dosing 15NH4+ into the rumen, ruminal NH3N and NAN pools were sampled over time for analyses of 15N enrichment . Compartmental analysis of both pools was used to quantify the percentage of microbial NAN that recycles in the rumen . Microbial NAN does not need to be fractionated from total NAN, assuming that only microbial NAN becomes labeled with 15N and that the ratio of microbial NAN:nonmicrobial NAN remains constant over time . Based on the data obtained from eight nonlactating cattle fed 85% corn silage diets at 1.5 to 1.0% BW, percentage of intraruminal recycling of microbial NAN was related to efficiency of bacterial protein synthesis (grams of CP/100 g of OM truly digested) in a curvilinear manner (y = 100 - .073x2) . From this function, recycling was predicted to be approximately 75% for dairy cows consuming 50:50 forage:concentrate diets at 3.5% of BW . However, more data are needed to evaluate intraruminal recycling of microbial NAN using this technique under different dietary conditions.

J Anim Sci, 1992 Oct, 70(10), 2959 - 69
Comparative feeding value of supplemental fat in steam-flaked corn- and steam-flaked wheat-based finishing diets for feedlot steers; Zinn RA; One hundred thirty crossbred steers (324 kg) were used in a 121-d comparative slaughter trial to evaluate the feeding value of fat in steam-flaked corn- (SFC) or wheat- (SFW) based diets . Treatments consisted of an 88% concentrate finishing diet containing 1) SFC, no fat; 2) SFC, 6% yellow grease (YG); 3) SFC, 6% cottonseed oil soapstock (COS); 4) SFW, no fat; 5) SFW, 6% YG; and 6) SFW, 6% COS . There were no interactions (P greater than .10) between grain type and performance response to supplemental fat . Fat supplementation increased (P less than .05) ADG by 7.3% and decreased (P less than .01) DMI/gain by 10.6% . Fat supplementation decreased (P less than .05) ruminal OM digestion by 5% and net flow of microbial N to the small intestine by 14.5% but did not affect (P greater than .10) total tract digestion of OM, ADF, or starch . Substituting SFW for SFC did not influence (P greater than .10) ADG but tended (P greater than .10) to increase DMI/gain and decreased (P less than .05) the NEm and NEg of the diet by 3.4 and 4.3%, respectively . Ruminal OM digestion was similar (P greater than .10) for SFC and SFW . Flow of microbial N to the small intestine was 12% greater (P less than .05) with SFW . Total tract digestibilities of OM and starch were similar (P greater than .10) for both grains . However, ADF digestion was lower (34%, P less than .01) with SFW . It is concluded that the feeding value of supplemental fat is similar for wheat- and corn-based finishing diets . The performance response to supplemental YG and COS was similar . The NEm and NEg values of YG were 6.35 and 4.93 Mcal/kg, respectively, whereas the corresponding values for COS were 5.69 and 4.60 Mcal/kg . Supplementation of growing-finishing diets with up to 6% (.45 kilograms/day) of fat did not directly influence body composition . The NE value of SFW was approximately 96% of the value of SFC.

CLAO J, 1992 Oct, 18(4), 232 - 6
A European fitting philosophy for aspheric, high-Dk RGP contact lenses; Kok JH; Microbial keratitis, the most serious complication of contact lens wear, is most frequently associated with soft contact lenses . Rigid gas permeable (RGP) lens wearers are less often affected . Increased use of high-Dk RGP lenses could reduce the number of cases of microbial keratitis . In Europe, aspheric high-Dk RGP lenses are very popular . This article presents practical guidelines for computer-aided fitting of aspheric RGP lenses . Base curve selection using the keratometer to determine the corneal topography is described . This method, which is inexpensive and time-saving, is suitable for fitting cosmetic contact lenses or lenses used in treating such corneal pathology as keratoconus.

J Vet Med Sci, 1992 Oct, 54(5), 891 - 5
Experimental Tonsillophilus suis granuloma in rats and guinea pigs; Murakami S et al.; Rats and guinea pigs were experimentally infected by intradermal and intraperitoneal inoculation of T . suis . These animals were observed for pathologic changes at various stages . Macroscopic observation disclosed visible grayish white soft nodules at the injection site in those inoculated intradermally and many grayish white nodules in the peritoneum of those inoculated intraperitoneally . Histopathological examination revealed the presence of characteristic microbial elements in the centre of the lesions . Various stages of the lesions were recognized; the early stage being abscess, the advanced stage being pus-forming granuloma and the final stage being residual granuloma . The microbial elements were composed of spores, thalli and multilocular tubers . Clubs were formed around microbial elements in rats inoculated intradermally and in guinea pigs inoculated intraperitoneally . The characteristic T . suis lesions in pigs were reproduced by experimental infection of this organisms in rats and guinea pigs, and thus the pathogenicity of T . suis was confirmed.

Cancer Res, 1992 Oct 1, 52(19), 5353 - 8
Differential inhibition of the epidermal growth factor-, platelet-derived growth factor-, and protein kinase C-mediated signal transduction pathways by the staurosporine derivative CGP 41251; Andrejauskas-Buchdunger E et al.; The microbial alkaloid staurosporine is a potent but nonselective inhibitor of protein kinases . The derivative CGP 41251 has been shown to exert a high degree of selectivity for inhibition of protein kinase C activity . Both compounds are powerful inhibitors of proliferation of both normal and transformed cells in vitro and exert antitumor efficacy in vivo . In this work we have studied the mode of action of these compounds by analyzing their effects on early events in the induction of proliferation by different growth stimuli . Both drugs blocked the phorbol ester-induced expression of the c-fos proto-oncogene . The effect of CGP 41251 was reversible, since its removal led to a normal expression of c-fos mRNA in response to phorbol 12-myristate 13-acetate . Submicromolar concentrations of CGP 41251 and staurosporine directly inhibited both the platelet-derived growth factor (PDGF) receptor autophosphorylation and the c-fos mRNA expression induced by PDGF stimulation of intact BALB/c 3T3 cells . In contrast, ligand-induced epidermal growth factor receptor autokinase activity in A431 carcinoma cells and epidermal growth factor-dependent c-fos mRNA expression were relatively insensitive to inhibition by CGP 41251 . Staurosporine suppressed signal generation by the epidermal growth factor receptor by reducing overall levels of the receptor . We conclude that CGP 41251 is a potent reversible inhibitor of protein kinase C and PDGF-mediated signal transduction . It inhibits the kinase activity of both protein kinase C and the PDGF receptor tyrosine kinase and the subsequent signaling cascade . The broad inhibition of kinases by staurosporine is also reflected at the cellular level and might contribute to the high toxicity of this compound, in comparison to CGP 41251.

Mol Ecol, 1992 Oct, 1(3), 175 - 81
The nodular endophytes of Coriaria spp . form a distinct lineage within the genus Frankia; Nick G et al.; Repeated attempts at isolating the Frankia endophyte of Coriaria spp . have not yielded infective microbial cultures that could fulfil Koch's postulates . In order to circumvent the critical isolation step, nodule endophytes of Coriaria were characterized directly by means of specific amplification of nodule DNA (PCR) followed by sequencing of part of the 16S rDNA gene . Three closely related sequences were obtained from nodules originating from France, Mexico and New Zealand, containing unique sequences different from all other Frankia strains characterized so far . The sequences obtained were closest (with 5 or 6 substitutions) to those of Frankia alni and those of Casuarina-infective Frankia strains, respectively . Two nucleotides unique to the Coriaria endophyte sequences were used to define specific primers, resulting in a hybridization test that could discriminate between Frankia DNAs originating from Coriaria nodules and those recovered from all cultured Frankia strains tested . The endophytes of Coriaria thus appear to form a distinct Frankia lineage.

Enferm Infecc Microbiol Clin, 1992 Oct, 10(8), 462 - 5
{Annual cost of microbial immunological tests for HIV-positive individuals in a hospital center}; Maroto MC et al.; The goal of this study is to increase the knowledge of the AIDS cost in a hospital . We have studied the HIV patients diagnosed during a year in our hospital and the charges of the serological tests performed to them . 20.8% of the tests were to study antibodies against HIV (only 20% were positive) . After patient distribution between extra or intrahospital origin, we highlight that 61% of the charges are attributed to patients who do not belong to the hospital but to its catchment area . We emphasize the problem that AIDS patients are creating to hospital, being necessary that personal select only useful tests honestly.

Kidney Int Suppl, 1992 Oct, 38, S68 - 77
Interleukin-1 and tumor necrosis factor and their naturally occurring antagonists during hemodialysis; Dinarello CA; Cytokines are polypeptides which possess various biological properties affecting host defense function and response to disease . Two cytokines, interleukin-1 (IL-1) and tumor necrosis factor (TNF) induce fever, hypotension and inflammation when injected into animals or human subjects . In humans injected with either IL-1 or TNF, sleepiness, generalized myalgias and headache are commonly reported . Therefore, the production of IL-1 and TNF as a consequence of hemodialysis was hypothesized to explain, in part, the signs and symptoms of the dialysis patient . Laboratory studies confirmed that the activation of complement and the passage of microbial products from the dialysate into the blood compartment induces the synthesis of IL-1 and TNF . Although elevated production of IL-1 and TNF in the mononuclear cells and in the circulation of patients during and after hemodialysis have been reported, these levels have not been a consistent finding and are low compared to the amount of dialysis related symptoms . Recent studies, however, demonstrate that IL-1 and TNF have naturally occurring antagonists which specifically block the biological activities of these two cytokines . The IL-1 receptor antagonist blocks IL-1 binding to cells but has no IL-1 activity of itself . Soluble TNF receptors prevent TNF from binding to its cellular receptors and hence serve as anti-TNF mechanisms . These inhibitors are currently in clinical trials for sepsis where efficacy has been demonstrated; however, the IL-1 receptor antagonist (IL-1Ra) and soluble TNF receptors (sTNFR) are likely candidates for use in dialysis patients with symptomatic hypotension . Although levels of IL-1Ra and sTNFR are elevated in patients on HD, these levels reflect the host response to inflammation . It is unclear whether acute or chronic administration of IL-1Ra or sTNFR will be beneficial in treating some of the acute or chronic changes seen in dialysis patients.

J Pharmacol Exp Ther, 1992 Oct, 263(1), 241 - 5
Pharmacological profile of HS-142-1, a novel nonpeptide atrial natriuretic peptide (ANP) antagonist of microbial origin . II . Restoration by HS-142-1 of ANP-induced inhibition of aldosterone production in adrenal glomerulosa cells; Oda S et al.; Atrial natriuretic peptide (ANP) is known to inhibit the aldosterone production by adrenal glomerulosa cells stimulated by angiotensin II . However, the mechanism of the inhibitory action is still somewhat uncertain . In this study we used HS-142-1, a novel nonpeptide antagonist for ANP receptor, to examine the role of cyclic GMP in the inhibition of aldosterone production by ANP . Aldosterone production by isolated bovine adrenal glomerulosa cells was stimulated by angiotensin II at a concentration of 10(-8) M . The angiotensin II-stimulated aldosterone production was inhibited by rat ANP in a dose-dependent manner at concentrations ranging from 10(-9) to 10(-7) M . HS-142-1, at concentrations of 0.1 to 100 micrograms/ml, reversed the inhibition by ANP of the angiotensin II-stimulated aldosterone production . On the other hand, intracellular concentration of cyclic GMP increased rapidly as early as 1 min after the exposure of the cells to 10(-8) M ANP in the presence of angiotensin II . This increase of intracellular cyclic GMP level was again reduced by HS-142-1 at concentrations similar to those that reversed the inhibition by ANP of the aldosterone production . These results suggest that ANP inhibits the aldosterone production through a guanylyl cyclase-coupled pathway in adrenal glomerulosa cells.

Crit Care Nurse, 1992 Oct, 12(7), 64 - 71
Pneumocystosis in patients with acquired immunodeficiency syndrome; Timby BK; Nurses need to be aware that pneumocystosis is one of the most common and lethal opportunistic infections among AIDS patients . They are extremely susceptible because HIV impairs physiological mechanisms for microbial defense . Patients exhibit only minor symptomatology while the unchecked P carinii organisms accumulate and replicate . Eventually as the sporozoans create a physical barrier between the alveolar-capillary membranes, ventilation becomes impaired and severe hypoxemia develops . Early clinical and diagnostic studies mimic the findings characteristic of ARDS . Unless correct staining techniques are used on sputum specimens, the organism often escapes identification . Thus, the diagnosis and specific treatment of PCP is often delayed . While supporting ventilation, the treatment of choice is administration of antimetabolite drugs, either trimethoprim-sulfame-thoxazole or pentamidine isethionate . The search for more effective, as well as safer, treatment of PCP continues . Life-threatening nursing diagnoses such as impaired gas exchange urgently require priority attention . Besides physical care, the severe hypoxemia demands nursing approaches to help the critically ill patient deal with fear and powerlessness . The nurse also assumes a surrogate role to patients abandoned by family and friends . The psychosocial aspects of nursing care require enormous skill and finesse, because the blood and respiratory isolation precautions can communicate mixed messages to lonely, frightened patients.

Res Microbiol, 1992 Oct, 143(8), 785 - 90
A one-step microbial DNA extraction method using "Chelex 100" suitable for gene amplification; de Lamballerie X et al.; "Chelex 100" chelating resin has been previously proposed for the rapid extraction of human DNA for polymerase chain reaction . Protocols are given for the rapid extraction of bacterial and viral DNA from cultures or clinical samples . The DNA samples obtained were suitable for use in polymerase chain reaction.

Adv Colloid Interface Sci, 1992 Sep 28, 41, 101 - 25
Nonlamellar phases formed by membrane lipids; Lindblom G et al.; A brief review of membrane lipids forming cubic and reversed hexagonal phases is presented . An emphasis is made on anionic lipids and particular microbial lipids.

Biochem J, 1992 Sep 15, 286 ( Pt 3), 923 - 7
Modification of vertebrate and algal prolyl 4-hydroxylases and vertebrate lysyl hydroxylase by diethyl pyrocarbonate . Evidence for histidine residues in the catalytic site of 2-oxoglutarate-coupled dioxygenases; Myllyla R et al.; A search for conserved amino acid residues within the cDNA-derived amino acid sequences of 2-oxoglutarate-coupled dioxygenases revealed the presence of two distinct motifs, spaced 49-71 amino acids apart, toward the C-terminal regions of these proteins . Each of the two common motifs contains an invariant histidine residue at a conserved position . The 2-oxoglutarate-coupled dioxygenases function in diverse processes, including the post-translational hydroxylation of proline and lysine residues in vertebrate collagens and the biosynthesis of microbial cephalosporins, yet they have a common reaction mechanisms, which requires the binding of Fe2+, 2-oxoglutarate, O2 and ascorbate at the catalytic site . The two regions of homology, and specifically the identical histidines, potentially represent functionally important sites related to their catalytic activity . Modification of histidine residues by diethyl pyrocarbonate inactivated vertebrate and algal prolyl 4-hydroxylase and vertebrate lysyl hydroxylase, indicating that histidine residues function in the catalytic site of these 2-oxoglutarate-coupled dioxygenases . Inactivation was prevented by the presence of co-substrates, but not by the peptide substrate . It is proposed that the histidine residues in the conserved motifs may function as Fe(2+)-binding ligands.

J Environ Pathol Toxicol Oncol, 1992 Sep-Oct, 11(5-6), 247 - 63
Ecotoxicological testing: small is reliable; Cairns J Jr et al.; The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact . Prominent in this change is an increasing emphasis on protecting the integrity of natural ecosystems, which incorporate community- and system-level properties as well as organismal and population processes . Consequently, support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as well . The reason for this trend is clear: the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests alone . Many of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or overcome . In particular, the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity testing . This article includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing protocols . An increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes . A shift in research focus is needed, however, to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.

Mol Cell Biol, 1992 Sep, 12(9), 3827 - 33
Isolation of a gene required for programmed initiation of development by Aspergillus nidulans; Adams TH et al.; In contrast to many other cases in microbial development, Aspergillus nidulans conidiophore production initiates primarily as a programmed part of the life cycle rather than as a response to nutrient deprivation . Mutations in the acoD locus result in "fluffy" colonies that appear to grow faster than the wild type and proliferate as undifferentiated masses of vegetative cells . We show that unlike wild-type strains, acoD deletion mutants are unable to make conidiophores under optimal growth conditions but can be induced to conidiate when growth is nutritionally limited . The requirement for acoD in conidiophore development occurs prior to activation of brlA, a primary regulator of development . The acoD transcript is present both in vegetative hyphae prior to developmental induction and in developing cultures . However, the effects of acoD mutations are detectable only after developmental induction . We propose that acoD activity is primarily controlled at the posttranscriptional level and that it is required to direct developmentally specific changes that bring about growth inhibition and activation of brlA expression to result in conidiophore development.

J Cell Physiol, 1992 Sep, 152(3), 646 - 53
Reversible G1 arrest of a human lung epithelial cell line by staurosporine; Lin Y et al.; Staurosporine, a microbial-derived protein kinase inhibitor, reversibly blocked non-synchronized, replicating cultures of the human lung epithelial cell line EKVX in the G1 phase of cell cycle and inhibited DNA synthesis and cell replication . The mechanism of this cell-cycle arrest in EKVX cells by staurosporine was likely due to inhibition of protein kinase C (PKC) because: 1) dose-dependent inhibition of DNA synthesis occurred at levels of staurosporine that inhibit phosphorylation of PKC substrate, 2) inhibition of DNA synthesis was also seen after treatment with another PKC inhibitor H7, but not by the chemically similar HA1004, which has a relative inhibitory specificity for cAMP-dependent protein kinase, and 3) the DNA synthesis was not inhibited by specific tyrosine kinase inhibitors Genistein and Lavendustin A at concentrations that inhibit tyrosine kinase activity . Removal of staurosporine from cell culture media resulted in a rebound in PKC activity and synchronized DNA synthesis in EKVX cultures . The reversibility of the inhibition was noted even after 5 days of treatment with staurosporine, and DNA synthesis remained synchronized for at least two rounds of cell replication after removal of staurosporine . Flow cytometric analysis confirmed that more than 90% of the cell population was blocked in the G1 phase after cells were treated with staurosporine for 24 h . Agents such as staurosporine may be useful for synchronizing cell populations to study cell-cycle specific biochemical events important for the regulation of cell replication in the EKVX cell line.

Int J Food Microbiol, 1992 Sep, 17(1), 37 - 45
Inhibition of PCR by components of food samples, microbial diagnostic assays and DNA-extraction solutions; Rossen L et al.; We have tested the influence on the polymerase chain reaction (PCR) of a large number of compounds found in food, in media used for selective propagation of food-borne pathogens or in DNA-extraction methods . PCR was found to be sensitive to large volumes of complex food samples containing high amounts of fat and protein, however, an extraction procedure based on treatment with hot NaOH/SDS reduced the effect significantly . Some culture media (Fraser, MLEB, MRB and Rappaport) interfered with the analysis and for most of the media it was possible to assign the inhibitory effect to one or more individual components . Several compounds (detergents, lysozyme, NaOH, alcohols, EDGA, EGTA) used in DNA extraction procedures were found to have some inhibitory effect . The inhibitory effects need to be taken into consideration when designing new tests.

Trans R Soc Trop Med Hyg, 1992 Sep-Oct, 86(5), 517 - 9
Determination of anti-giardial activity in vitro by means of soluble formazan production; Wright CW et al.; A new microplate assay for the determination of activity in vitro against Giardia intestinalis has been developed in which viability is measured by soluble formazan production from a tetrazolium reagent . Metabolic reduction of the latter gives rise to a coloured product which may be determined directly by optical density measurement . Using this method the anti-giardial activities of more than 20 anti-microbial compounds have been assessed . The results obtained with a number of known anti-giardial agents, including metronidazole (50% inhibitory concentration {IC50} = 2.98 microM) and furazolidone (IC50 = 4.14 microM), compare well with previously published data; mepacrine, however, was found to produce a biphasic dose-response curve from which two IC50 values (0.816 and 6.83 microM) were obtained . This method provides a convenient means by which the search for new anti-giardial agents may be facilitated.

Prikl Biokhim Mikrobiol, 1992 Sep-Oct, 28(5), 694 - 7
{Sorption of enzymes on ion exchange resins of various structure}; Rudometova NV et al.; The isothermic adsorption of microbial and animal enzymes on carboxyl and sulpha-cation exchange resins was studied . The adsorption isotherms are curves with a maximum . The adsorption of alpha-amylase was studied in the presence of organic solvents . It was found that organic solvents influenced the isothermic adsorption of alpha-amylase, which is associated with changes in the interactions between protein molecules in solution . The adsorption system was in equilibrium in all the cases.

Biofizika, 1992 Sep-Oct, 37(5), 900 - 9
{Conservativeness of residues in nonpolar nuclei of microbial ribonucleases}; Il'in VA et al.; We present the application of a new method for analysis of nonpolar structure of proteins . A detailed analysis of the composition and properties of nonpolar nuclei and microclusters of microbial ribonucleases with known sequence have been carried out on the basis of 3D-structure of RNase Pbi and that of RNase Ti . It has been shown that all residues in nonpolar nuclei have high homology, about 95% for proteins with an identical scheme of S-S bridges and about 75% for nonidentical scheme of S-S bridges . The stability of nonpolar nuclei, conservation of their composition and their position in the protein globule allows one to assume that they play an important functional role in protein structure and possibly can be considered as independent structural elements of 3D-structure of a protein.

Immunol Today, 1992 Sep, 13(9), 345 - 8
The role of hsp90 in fungal infection; Matthews R et al.; The immunodominant antigens of many microbial pathogens are heat shock proteins (hsps) . In systemic candidal infections, a major target of protective antibody is an epitope shared with human hsp90 . Here, Ruth Matthews and James Burnie suggest that fungal hsp90 plays a key pathogenic role in systemic infection by either binding to certain serum proteins, causing them to malfunction, or by mimicking the functional activity of other proteins.

J Dairy Sci, 1992 Sep, 75(9), 2517 - 23
Effects of lasalocid and undegradable protein on growth and body composition of Holstein heifers; Steen TM et al.; Effects of lasalocid (0 or 200 mg/d per head) and undegradable intake protein (32 vs . 42% of CP in concentrate) on growth and body composition were evaluated using 32 Holstein heifers (253 kg initial BW, SE = 4) . Heifers were housed in an open barn in eight pens of 4 heifers and fed 12.7 kg per pen daily of experimental concentrate with medium quality fescue hay for ad libitum consumption for 12 28-d periods . Body measurements were taken every 28 d; ultrasonic fat and muscle depths at the 13th rib, empty body fat, and protein were measured every 84 d . Heart girth and fat and muscle depth at the 13th rib increased when lasalocid and undegradable protein were fed individually, but not in combination . Rates of average daily gain and feed efficiency were not increased significantly when lasalocid and undegradable protein were fed . Data suggest that the combination of lasalocid and undegradable protein may have impaired microbial protein synthesis in the rumen, thereby influencing changes in body composition.

J Dairy Sci, 1992 Sep, 75(9), 2447 - 53
In vivo degradation of protein in diets formulated for two degradabilities; Seymour WM et al.; In vivo protein degradability of two basal diets and bacterial protein synthesis were determined in four lactating dairy cows equipped with ruminal and duodenal cannulas . The diets contained corn silage, high moisture corn, and either soybean meal or a 60:40 mixture of soybean meal and corn gluten meal . Diets had calculated ruminal protein degradabilities of 69.3 and 62.3%, respectively . Both diets contained approximately 14% CP and 21% ADF . Duodenal flows of total N, total protein N, microbial N, and duodenal recovery of ingested N tended to be higher for the soybean meal and corn gluten meal diet; ruminally degraded CP was significantly lower than for the soybean meal diet . Ruminal ammonia and plasma urea concentrations tended to be higher for the soybean meal diet, as were molar percentages of butyrate and valerate . Ruminal and total tract apparent digestibilities of CP and OM were not significantly different between diets . Ruminal degradation of protein in the two diets differed by the amount predicted by the NRC system for lactating cows, although absolute values were lower than most previous estimates for similar diets.

J Clin Periodontol, 1992 Sep, 19(8), 595 - 600
Clinical effects of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine . Mediating influence of periodontal probing depth; Reynolds MA et al.; The clinical and microbial effects of a single episode of simultaneous ultrasonic scaling and subgingival irrigation with chlorhexidine (CHX) were studied as a function of clinical probing depth in patients with adult periodontitis . 60 patients were randomly assigned to receive subgingival irrigation under cavitation with either sterile water or 0.12% CHX delivered through the tip of an ultrasonically activated scaler as part of initial periodontal therapy in a double-blind study design . 3 periodontal sites were randomly selected for examination from each patient on the basis of clinical probing depth, with 1 site being selected within each of the following ranges: 1-3 mm, 4-6 mm, and 7-9 mm . Pretreatment and post-treatment (days 14 and 28) clinical assessments included a plaque index (PI), gingival index (GI), and clinical probing depth (CPD) . Subgingival specimens also were collected from 1-3 mm and 4-6 mm sites on a random subset of patients (15 per group) . Plaque counts of spirochetes and motile organisms were made by darkfield microscopy . Significant reductions in PI, GI, and CPD were observed among all sites within both treatment groups at 14 and 28 days post-treatment . CHX irrigation resulted in a significantly greater reduction in CPD than did water among sites initially probing 4-6 mm at both 14 and 28 days post-treatment (25% versus 13% and 31% versus 18%, respectively) . Spirochete counts were modestly but nonsignificantly reduced at 14 days post-treatment among sites 4-6 mm within both treatment groups . These results suggest that subgingival irrigation with CHX during ultrasonic scaling provides differential clinical benefits that are site-dependent.

Baillieres Clin Obstet Gynaecol, 1992 Sep, 6(3), 439 - 60
Complement and pregnancy: new insights into the immunobiology of the fetomaternal relationship; Holmes CH et al.; Recent studies have revealed that human trophoblast expresses three membrane-bound proteins which function specifically to regulate the activity of complement . These proteins are already known to be widely distributed in normal adult tissues where they protect host cells from damage resulting from the fortuitous deposition of activated complement components . Their activities are focused at two distinct steps in the complement pathway . Decay accelerating factor (DAF, CD55) and membrane co-factor protein (MCP, CD46) act at the level of the C3 convertase enzymes which activate C3 to C3b . A further protein, CD59, directly regulates the formation and function of the terminal cytolytic membrane attack complex (MAC) by specifically interacting with C8 and C9 . These proteins appear to play an important role in the maintenance of normal human pregnancy . DAF, MCP and CD59 are all expressed where trophoblast surfaces are in contact with maternal blood and tissues and expression occurs from at least 6 weeks of gestation . The semi-allogeneic human conceptus therefore appears to be effectively protected from maternal complement-mediated damage arising either from alternative or classical pathway activation or in a bystander fashion following a response to microbial infection in the mother . Complement regulatory protein deficiency disorders with clinically demonstrable consequences especially in terms of haemolytic disease are known to exist and have proved valuable in establishing the biological role of these proteins in vivo . The demonstration of this new family of immunoregulatory proteins on trophoblast raises important questions about the potential involvement of these products in pregnancy pathologies.

Br J Nutr, 1992 Sep, 68(2), 365 - 72
Acetylation of peptides inhibits their degradation by rumen micro-organisms; Wallace RJ; Proteins and peptides were acetylated using acetic anhydride in order to block their N-terminal amino groups and thereby to prevent their hydrolysis by rumen microbial aminopeptidases . The effects of acetylation on peptide breakdown and ammonia production were determined by incubating unmodified and acetylated substrates with sheep rumen micro-organisms in vitro . Ammonia production from casein and lactalbumin was affected little by acetylation, but acetylation of the corresponding enzymic hydrolysates caused ammonia production to be more than halved after 3-6 h incubation . Estimation of peptides remaining in rumen fluid showed that the decreased ammonia production was a consequence of peptides being hydrolysed more slowly . Acetylated Ala-Ala, Ala-Ala-Ala (Ala3), Leu-Gly-Gly, Phe-Gly-Gly and Val-Gly-Ser-Glu survived incubation with rumen fluid in vitro for 6 h, whereas almost none of the corresponding unmodified peptides was present at 6 h . The protection afforded to larger pure peptides was less reliable: for example, 72% of acetylated bradykinin was hydrolysed after 1 h . N-Acetyl Ala3 had only a minor inhibitory effect on the breakdown of Ala3 and Ala4, suggesting that although acetyl peptides were broken down more slowly than unmodified peptides they did not inhibit peptidase activity.

Br J Nutr, 1992 Sep, 68(2), 349 - 64
The intake, digestion and protein degradation of grazed herbage by early-weaned lambs; Cruickshank GJ et al.; Sixty-four intact lambs and twenty-four lambs fitted with a duodenal cannula were weaned at 6 weeks of age and grazed pure species swards of either lucerne (Medicago sativa), white clover ((Trifolium repens), ryegrass (Lolium perenne) or prairie grass (Bromus catharticus) for 6 weeks . Intake and duodenal digesta flow were estimated when lambs were 8 and 12 weeks of age . Lambs grazing the two legume species grew at a similar rate, as did lambs grazing the two grass species . Legumes promoted a 38% higher growth rate than grasses . The higher growth rate of lambs grazing legumes was associated with a 36% higher digestible organic matter intake (DOMI; 29.5 and 21.7 g/kg body-weight per d for legume and grass respectively) and a 33% higher duodenal non-ammonia-nitrogen (NAN) flow (1.22 and 0.92 g/kg body-weight per d respectively) . There was no species difference in the site of organic matter digestion; on average 0.56 of DOMI was apparently digested in the rumen and 0.77 of DOMI was truly digested in the rumen . There was no difference in duodenal NAN flow, relative to DOMI (average, 43 g/kg) or to organic matter apparently digested in the rumen (80 g/kg) . Similarly, there was no difference in microbial N flow relative to duodenal NAN (0.50 g/g) and organic matter apparently (41 g/kg) or truly (29 g/kg) digested in the rumen . It was concluded that the higher growth rates achieved by lambs grazing legumes were due to higher intakes which increased the total quantity of nutrients supplied despite more protein being lost in the rumen of lambs consuming legumes.

Appl Environ Microbiol, 1992 Sep, 58(9), 3020 - 6
Importance of unattached bacteria and bacteria attached to sediment in determining potentials for degradation of xenobiotic organic contaminants in an aerobic aquifer; Holm PE et al.; The bacterial abundance, distribution, and degradation potential (in terms of degradation versus lack of degradation) for four xenobiotic compounds in an aerobic aquifer sediment have been examined in laboratory and field experiments . The xenobiotic compounds studied were benzene, toluene, o-xylene, and naphthalene (all at concentrations of approximately 120 micrograms/liter) . The aerobic degradation experiments ran for approximately 90 days at 10 degrees C, which corresponded to the groundwater temperature . At the end of the experiment, the major part of the microbial biomass, quantified as acridine orange direct counts, was attached to the groundwater sediment (18 x 10(6) to 25 x 10(6) cells per g {dry weight}, and only a minor part was unattached in the groundwater (0.6 x 10(6) to 5.5 x 10(6) cells per ml) . Experiments involving aquifer sediment suspensions showed identical degradation potentials in the laboratory and in the field . However, laboratory experiments involving only groundwater (excluding aquifer sediment) showed less degradation potential than in situ experiments involving only groundwater, indicating that the manipulation or approach of the laboratory experiments could affect the determination of the degradation potentials . No differences were observed between the groundwater-only and the sediment compartments in the in situ experiments in the ability to degrade the compounds, but the maximum degradation rates were substantially lower in the groundwater-only compartment . Preparations used in laboratory experiments for studying the degradation potential for xenobiotic organic contaminants should contain sediment to obtain the highest numbers of bacteria as well as the broadest and most stable degradation.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1992 Sep, 58(9), 2901 - 9
Dynamic mathematical model to predict microbial growth and inactivation during food processing; Van Impe JF et al.; Many sigmoidal functions to describe a bacterial growth curve as an explicit function of time have been reported in the literature . Furthermore, several expressions have been proposed to model the influence of temperature on the main characteristics of this growth curve: maximum specific growth rate, lag time, and asymptotic level . However, as the predictive value of such explicit models is most often guaranteed only at a constant temperature within the temperature range of microbial growth, they are less appropriate in optimization studies of a whole production and distribution chain . In this paper a dynamic mathematical model--a first-order differential equation--has been derived, describing the bacterial population as a function of both time and temperature . Furthermore, the inactivation of the population at temperatures above the maximum temperature for growth has been incorporated . In the special case of a constant temperature, the solution coincides exactly with the corresponding Gompertz model, which has been validated in several recent reports . However, the main advantage of this dynamic model is its ability to deal with time-varying temperatures, over the whole temperature range of growth and inactivation . As such, it is an essential building block in (time-saving) simulation studies to design, e.g., optimal temperature-time profiles with respect to microbial safety of a production and distribution chain of chilled foods.

Appl Environ Microbiol, 1992 Sep, 58(9), 2840 - 5
Effects of Beauveria bassiana on embryos of the inland silverside fish (Menidia beryllina); Genthner FJ et al.; A chemical toxicity and teratogenicity test was adapted to assess potential adverse effects of a microbial pest control agent on a nontarget fish . Developing embryos of the inland silverside, Menidia beryllina, were exposed to conidiospores of the insect-pathogenic fungus Beauveria bassiana . Embryo rupture and death were observed . Embryo rupture did not always result in death, nor was death always associated with embryo rupture . Adherence of spores to the chorion, followed by germination and penetration by the germ tube, probably caused the embryos to rupture . Statistically significant (P less than or equal to 0.05) responses were observed in tests in which conidiospore concentrations were greater than or equal to 8.3 x 10(4) or less than or equal to 1.5 x 10(6)/ml . Conidiospores treated with a dispersant (biological detergent) showed significantly less binding (P less than or equal to 0.01) to embryos than did untreated spores . Both detergent-treated and heat-killed spores failed to cause significant adverse effects.

Z Gesamte Inn Med, 1992 Sep, 47(9), 391 - 3
{Current status and change in infectiology}; Handrick W et al.; Clinical infectiology had passed through a marked transformation in the past, it is changing in the present time and will do so in the future . The most important factors for these changes are: the change of the living standard of the people, the increased number of persons with dispositions for infections, a better knowledge about the microbial etiology of infections and new possibilities of diagnostics and therapy of infectious diseases . The importance of these changes are in Germany inadequately reflected not only in the clinical practice but also in medical teaching and research . The reintegration of the infectiology as an important medical specialty in the Germany's medicine is urgently indicated.

J Pharm Sci, 1992 Sep, 81(9), 849 - 57
A time hierarchy-based model for kinetics of drug disposition and its use in quantitative structure-activity relationships; Balaz S et al.; By using the time hierarchy of the processes determining the fate of drugs in biosystems (absorption, transport, distribution, protein binding, and elimination), a one-compartment open model is formulated at a subcellular level for the disposition phase of pharmacokinetics . The resulting disposition function describes the kinetics of the intracellular disposition of drugs as determined by their hydrophobicity, acidity or basicity, affinity to proteins, and rate parameters of elimination . Structure-activity relationships, based on the function with incorporated extrathermodynamic relations, fit the literature data well (fixed-time bioactivity-hydrophobicity profiles, kinetics of microbial degradation of organic compounds, and kinetics of analgesic effects of fentanyl derivatives in rats) . Application of the approach, creating a basis for the construction of model-based quantitative structure-time-activity relationship, to biosystems of varying complexity is discussed.

Acta Paediatr Suppl, 1992 Sep, 381, 149 - 54
Oral gentamicin is not effective treatment for persistent diarrhea; Bartlett AV et al.; We conducted a randomized, double-blind, placebo controlled clinical trial of oral gentamicin (10 milligrams/kilogram body weight/day for five days) in treatment of unselected cases of persistent diarrhea (duration 14-18 days at initiation of treatment) among 3-36-month-old children in a rural Guatemalan community . Following random assignment of each child to a treatment group, the appropriate dose of gentamicin or placebo was administered to the child three times daily by a study nurse; this nurse also identified the presence or absence of diarrhea on each day of treatment and for the next two days . Cure was defined as cessation of diarrhea during the five-day treatment period, sustained through at least the two days after completion of treatment . Among 92 evaluable cases who entered the clinical trial, there was essentially no difference in cure rate between gentamicin and placebo treatment groups (42% versus 43%) . Enteroadherent strains of Escherichia coli were identified in 46% of children tested in this trial; no significant difference existed between treatment groups in frequency of isolation of this or any other enteropathogen . Among 40 children having successful duodenal cultures immediately prior to beginning treatment, > or = 10(4) aerobic organisms per milliliter of fluid were identified in 12 (30%); treatment groups did not differ substantially with respect to proportion of children identified with this level of duodenal microbial colonization . Failure of gentamicin treatment did not appear to be explained by emergence of resistance, although a small number of resistant enteropathogens were identified near the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Anal Chem, 1992 Sep 1, 64(17), 1755 - 9
Bioluminescence detection system of mutagen using firefly luciferase genes introduced in Escherichia coli lysogenic strain; Lee SM et al.; A rapid and convenient microbial sensing system for mutagens was developed based upon the induction of prophage from Escherichia coli lysogenic strain and bioluminescence . The system consisted of lysogenic E . coli encoding firefly luciferase genes and a photodetection system . Measurement of mutagen mitomycin C was achieved by measuring the luminescence intensity emitted from E . coli lysogenic strain for the recombinant phage in the presence of luminescence substrates . Approximately 1 h after addition of mitomycin C, the luminescence began to be observed, and 3 h after, it attained a level of 2 times greater than that of 1 h . Irradiation with ultraviolet light also produced light based on induction of phage from the E . coli lysogenic strain for the recombinant phage . On the other hand, when nonmutagenic toxic compounds like sodium azide were added to the reaction medium, luminescence was not observed . Mitomycin C could be detected within 1 h with this sensing system, at concentrations down to 10(2) ng/assay.

Allerg Immunol (Paris), 1992 Sep, 24(7), 256 - 61
{Skin tests in allergic vasculitis}; Grosshans E et al.; For etiologic checking of cutaneous vasculitis, skin testing may be of valuable help: epicutaneous patch-tests with delayed lecture (48 h.) performed with contact haptens (rubber allergens, azo dyes, resins ...) or drugs in pigmented progressive purpuric skin eruptions; prick-tests submitted to delayed (6-8 h.) clinic and histologic lecture, performed with miscellaneous drug or food-derived, microbial or environmental antigens in necrotizing vasculitis . In these conditions skin testing should be approached with great caution, because of the occurrence of non relevant positive reactions and the risk of precipitation of cutaneous or disseminated lesions of vasculitis.

J Clin Invest, 1992 Sep, 90(3), 906 - 12
Live Borrelia burgdorferi preferentially activate interleukin-1 beta gene expression and protein synthesis over the interleukin-1 receptor antagonist; Miller LC et al.; Lyme arthritis is one of the few forms of chronic arthritis in which the cause is known with certainty . Because cytokines are thought to contribute to the pathogenesis of chronic arthritis, we investigated the effect of the Lyme disease spirochete, Borrelia burgdorferi, on the gene expression and synthesis of IL-1 beta and the IL-1 receptor antagonist (IL-1ra) in human peripheral blood mononuclear cells . Live B . burgdorferi induced fivefold more IL-1 beta than IL-1 alpha and sevenfold more IL-1 beta than IL-1ra; LPS or sonicated B . burgdorferi induced similar amounts of all three cytokines . This preferential induction of IL-1 beta was most dramatic in response to a low passage, virulent preparation of B . burgdorferi vs . three high passage avirulent strains . No difference in induction of IL-1ra was seen between these strains . The marked induction of IL-1 beta was partially diminished by heat-treatment and abrogated by sonication; IL-1ra was not affected . This suggested that a membrane component(s) accounted for the preferential induction of IL-1 beta . However, recombinant outer surface protein beta induced little IL-1 beta . By 4 h after stimulation, B . burgdorferi induced sixfold more IL-1 beta protein than LPS . In contrast to LPS-induced IL-1 beta mRNA which reached maximal accumulation after 3 h, B . burgdorferi-induced IL-1 beta mRNA showed biphasic elevations at 3 and 18 h . B . burgdorferi-induced IL-1ra mRNA peaked at 12 h, whereas LPS-induced IL-1ra mRNA peaked at 9 h . IL-1 beta synthesis increased in response to increasing numbers of spirochetes, whereas IL-1ra synthesis did not . The preferential induction by B . burgdorferi of IL-1 beta over IL-1ra is an example of excess agonist over antagonist synthesis induced by a microbial pathogen, and may contribute to the destructive lesion of Lyme arthritis.

Arch Biochem Biophys, 1992 Sep, 297(2), 362 - 7
Inhibition of glucocerebrosidase and induction of neural abnormality by cyclophellitol in mice; Atsumi S et al.; Cyclophellitol, a cyclitol with an epoxide, is a novel microbial secondary metabolite that inhibits beta-glucosidase and beta-glucocerebrosidase . Daily administration of cyclophellitol induces a severe abnormality of the nervous system in mice while it has no toxicity in various cultured cells . It was shown to inhibit glucocerebrosidase in vivo significantly in mice and the content of glucocerebroside in liver, spleen, and brain was increased markedly . The enzyme activity was completely suppressed in brain, liver, spleen, kidney, and muscle . On the other hand hexosaminidase activity was not affected in all tissues . After a single administration of cyclophellitol the maximal inhibition of glucocerebrosidase was observed within 30 min in brain and liver, and the inhibition lasted for 2-4 days . A single administration of cyclophellitol also induced a severe abnormality of the nervous system known as Gaucher's-like disease in mice . Conduritol B epoxide is also known to inhibit glucocerebrosidase and induce Gaucher's like-disease in mice by repetitive injection . Cyclophellitol was shown to be more potent than conduritol B epoxide in inhibition of glucocerebrosidase and in induction of the neural abnormality.

Arch Biochem Biophys, 1992 Sep, 297(2), 199 - 204
Characterization and partial purification of an insulinase from Neurospora crassa; Kole HK et al.; An insulin-binding metal- and thiol-dependent proteinase has been purified 1491-fold from high speed cytosolic fractions of the fungus Neurospora crassa . This enzyme resembles insulin-degrading enzymes (insulinases) present in mammalian cells and in Drosophila melanogaster in the following ways: (i) it degrades radiolabeled insulin with a specificity similar to that of rat muscle insulinase, as demonstrated by HPLC analysis of the degradation products; (ii) it is inhibited by bacitracin, EDTA, 1,10-phenanthroline, and the sulfhydryl-reactive compounds N-ethylmaleimide and p-chloromercuribenzoate, but not by inhibitors of serine proteases or by lysosomal protease inhibitors . Cross-linking with 125I-insulin labels a band of ca . 120 kDa, and several smaller bands which may represent degradation products . The N . crassa insulinase is stimulated by Mn2+ and strongly inhibited by Zn2+; Mn2+ can also reactivate the enzyme after inhibition by EDTA, but Zn2+ is ineffective . The N . crassa protein differs in this regard from mammalian and insect insulinases which are generally activated by both Mn2+ and Zn2+ . This finding extends the apparent evolutionary conservation of these metal- and thiol-dependent proteases into the microbial realm.

Neurochem Res, 1992 Sep, 17(9), 887 - 91
Molecular mimicry and the autoimmune response to the peripheral nerve myelin P0 glycoprotein; Adelmann M et al.; In the Lewis rat immunisation with the myelin P0 glycoprotein can induce an inflammatory demyelinating disease of the peripheral nervous system, experimental allergic neuritis (EAN), which has many clinical and histopathological parallels with the human disease the Guillain-Barre syndrome . In view of the reported association of GBS with a number of infectious agents we have investigated whether "molecular mimicry" may occur between microbial antigens and the P0 protein that could possibly trigger a similar pathogenic autoimmune response in man . A computer search of the available protein sequence data bases identified several absolute sequence homologies between P0 and viral proteins that involve five or more consecutive amino acid residues . Four of these sequence homologies involved viral pathogens previously associated with the Guillain-Barre syndrome, namely Epstein-Barr virus (EBV), cytomegalovirus (CMV), Varicella zoster virus (VZV) and human immunodeficiency virus I (HIV I) . Although, sequence homologies were also found between viral peptides and the neuritogenic determinants of P0, residues 56-71 and 180-199, these homologies proved incapable of eliciting EAN in the Lewis rat . These observations are discussed with reference to the role that molecular mimicry between T cell epitopes on pathogen derived antigens and the P0 protein may play in the pathogenesis of the Guillain-Barre syndrome.

Br J Pharmacol, 1992 Sep, 107(1), 22 - 6
Different patterns of protein kinase C redistribution mediated by alpha 1-adrenoceptor stimulation and phorbol ester in rat isolated left ventricular papillary muscle; Otani H et al.; 1 . In rat left ventricular papillary muscle, phenylephrine, an alpha 1-adrenoceptor agonist, had a staurosporine-sensitive positive inotropic effect and increased the particulate-associated protein kinase C (PKC) activity without significant changes in total PKC activity or in cytosolic Ca2+/phospholipid-independent kinase (PKI) activity . 2 . A PKC stimulant, phorbol 12,13-dibutyrate (PDBu), decreased contractility and slightly increased PKC activity in the particulate fractions, with a marked decrease and increase in total PKC and PKI activities, respectively . 3 . The PDBu-induced negative inotropic response was attenuated by two protease inhibitors, leupeptine and a microbial peptide isolated from Aspergillus japonicus (E-64), which are known to inhibit the conversion of particulate-associated PKC to PKI . 4 . Such differences in the patterns of PKC redistribution, i.e . marked increases in particulate PKC and cytosolic PKI activities caused by phenylephrine and PDBu, respectively, may account for the opposite inotropic effects of PKC stimulation by an alpha 1-agonist and a phorbol ester.

J Environ Pathol Toxicol Oncol, 1992 Sep-Oct, 11(5-6), 293 - 7
Agriculture and environment; Hafiz A; Agriculture came into existence about 15,000 years ago and passed through different stages of gathering, hunting, hoe culture, and sedentary agriculture, followed by modern agriculture . It began simultaneously in five world centers concentrating on different crops, most suited to the respective areas, and it was affected by changes in climate which determined the distribution of populations and their occupations . With the increase in population, the need for food progressively increased, necessitating introduction of modern agriculture to enhance production . The indiscriminate and faulty use of advanced technology to meet the food demand of fast-increasing populations added to its share to the destruction of the environment . The two approaches that contributed to this were horizontal expansion and vertical expansion . The former resulted in deforestation, desertification, soil erosion, land salting, and water logging, as well as the frequent occurrence of droughts and famines; the latter destroyed the soil structure and fertility through decreased microbial populations, fish culture, wildlife and bird sanctuaries, in addition to producing water and soil pollution and serious health hazards in human beings and fauna . The real culprit of this geobiologic devastation is the population growth rate, which needs to be contained at safer levels.

Appl Biochem Biotechnol, 1992 Sep, 36(3), 199 - 210
A biosensor for L-proline determination by use of immobilized microbial cells; Simonian AL et al.; A biosensor to quantify L-proline within 10(-5)-10(-3) mole/L concentration is described . Immobilized Pseudomonas sp . cells grown in a medium containing L-proline as the only source of carbon and nitrogen were used to create the biosensor . The cells oxidized L-proline specifically consuming O2 and did not react with other amino acids and sugars . The change in oxygen concentration was detected with a Clark oxygen membrane electrode . The cells were immobilized by entrapment in polyvinyl alcohol (PVA) cryogel . The resultant biocatalyst had a high mechanical strength and retained its L-proline-oxidizing ability for at least two months.

Khirurgiia (Mosk), 1992 Sep-Oct, (9-10), 29 - 35
{Intralymphatic drug therapy--a pathogenetically substantiated method of treatment in peritonitis}; Kuliev SH et al.; The method of endolymphatic drug therapy (EDT) suggested by the authors has some advantages over the method of endoarterial therapy (which has proved to be effective in clinical practice) because it is aimed not only at control of the microbial flora, but also at correction of rheologic and microcirculatory disorders, improvement of the processes of tissue respiration and metabolism, stimulation of the intestine, prevention of the damaging effect of enzymes, toxins, and poisons on the organs and tissues of the body, and at correction of disorders of the immune status with promotion of the barrier function of the lymph nodes and the lymphatic system as a whole . EDT may be recommended for wide use in the clinic in the treatment of patients with peritonitis and other serious surgical infections unresponsive to the generally applied methods of management.

FEBS Lett, 1992 Aug 31, 309(1), 68 - 72
The amino acid sequence of a 20 kDa bifunctional subtilisin/alpha-amylase inhibitor from bran {correction of brain} of rice (Oryza sativa L.) seeds; Ohtsubo K et al.; A 20 kDa bifunctional inhibitor of the microbial proteinase, subtilisin, and the alpha-amylase from the larvae of the red flour beetle (Tribolium castaneum) was purified from bran of rice seeds by saline extraction, precipitation with ammonium sulphate, ion-exchange chromatography on DEAE-Cellulose and Toyopearl CM-650, and preparative HPLC on Vydac C18 . The complete primary structure was determined by automatic degradation of the intact, reduced and S-alkylated protein, and by manual DABITC/PITC micro-sequencing of peptides obtained from the protein following separate enzymic digestions with trypsin, pepsin, chymotrypsin, elastase and the protease from S . aureus V8 . The protein sequence, which contained 176 residues, showed strong homology with similar bifunctional inhibitors previously isolated from wheat and barley which are related to the Kunitz family of proteinase inhibitors from legume seeds.

Eur J Biochem, 1992 Aug 15, 208(1), 41 - 51
The three-dimensional structure of guanine-specific ribonuclease F1 in solution determined by NMR spectroscopy and distance geometry; Nakai T et al.; Two-dimensional 1H-NMR studies have been performed on ribonuclease F1 (RNase F1), which contains 106 amino acid residues . Sequence-specific resonance assignments were accomplished for the backbone protons of 99 amino acid residues and for most of their side-chain protons . The three-dimensional structures were constructed on the basis of 820 interproton-distance restraints derived from NOE, 64 distance restraints for 32 hydrogen bonds and 33 phi torsion-angle restraints . A total of 40 structures were obtained by distance geometry and simulated-annealing calculations . The average root-mean-square deviation (residues 1-106) between the 40 converged structures and the mean structure obtained by averaging their coordinates was 0.116 +/- 0.018 nm for the backbone atoms and 0.182 +/- 0.015 nm for all atoms including the hydrogen atoms . RNase F1 was determined to be an alpha/beta-type protein . A well-defined structure constitutes the core region, which consists of a small N-terminal beta-sheet (beta 1, beta 2) and a central five-stranded beta-sheet (beta 3-beta 7) packed on a long helix . The structure of RNase F1 has been compared with that of RNase T1, which was determined by X-ray crystallography . Both belong to the same family of microbial ribonucleases . The polypeptide backbone fold of RNase F1 is basically identical to that of RNase T1 . The conformation-dependent chemical shifts of the C alpha protons are well conserved between RNase F1 and RNase T1 . The residues implicated in catalysis are all located on the central beta-sheet in a geometry similar to that of RNase T1.

J Immunol, 1992 Aug 15, 149(4), 1304 - 10
Components of the protein kinase C pathway induce Ia expression after injection into macrophages; Smith MR et al.; Macrophages are activated by a variety of microbial and cytokine stimuli . One feature of activation is the induction of class II Ag (Ia) on the cell surface . To understand the intracellular events that occur during activation, we investigated various agents with intracellular activities, and examined their effects on the induction of Ia . We first noted that several agents that activate protein kinase C (PKC) induced Ia, and that several inhibitors of PKC inhibited Ia induction by IFN-gamma . To directly test whether PKC induced Ia, we microinjected normal peritoneal macrophages with this enzyme and other intracellular mediators, then examined Ia expression . We observed that injection of PKC itself, or of other intracellular proteins thought to participate in the PKC pathway (Ras or phospholipase C gamma) strongly induced Ia expression . The Ia-inducing activity of transforming Ras protein was blocked by kinase inhibitor treatment of cells, suggesting that Ras signal transduction requires kinase activity . On the other hand, components of the protein kinase A pathway (phospholipase A2 and protein kinase A itself) did not induce Ia . Thus, the PKC pathway can control expression of macrophage surface Ia, possibly by regulating the genes of the MHC, and may play many other roles in the activation of macrophages.

Sci Total Environ, 1992 Aug 12, 123-124, 205 - 17
Biological and chemical interactions of pesticides with soil organic matter; Bollag JM et al.; There is little doubt that organic matter plays a major role in the binding of pesticides in soil, and that this phenomenon is usually the most important cause for interaction of pesticides in the soil environment . Fulvic or humic acids are the chemicals most commonly involved in the binding interactions . Binding can occur with the original pesticide or a transformation product, the reaction being caused by abiotic agents or biotic agents (microbial or plant enzymes) . The reactions or processes involved appear to be the same as those responsible for the formation of humic substances, i.e . for the humification process . Binding of pesticides to organic matter can occur by sorption (Van der Waal's forces, hydrogen bonding, hydrophobic bonding), electrostatic interactions (charge transfer, ion exchange or ligand exchange), covalent bonding or combinations of these reactions . Our investigation focused primarily on the binding of substituted phenols and aromatic amines to humus monomers and humic substances . In model reactions, we demonstrated the formation of covalent linkages between pesticides and humus constituents and fulvic or humic acids in the presence of phenol oxidases or clay minerals . With chlorinated phenols and carboxylic acids, it was possible to isolate and identify cross-coupling products and to elucidate the site and type of binding . The binding of chlorinated phenols to humic substances was determined by using 14C-labelled chemicals and by measuring the uptake of radioactivity by the humic material . These experiments provide a base for explaining the formation of bound residues in certain cases and for assuming the toxic potential of the immobilized pollutants.

J Anim Sci, 1992 Aug, 70(8), 2533 - 41
Digestion, feed intake, and live weight gain by cattle consuming bermudagrass hay supplemented with whey; Galloway DL Sr et al.; Three experiments were conducted with cattle consuming bermudagrass hay to determine whether low-level supplements of whey alone, corn alone, or whey plus corn affect feed intake, digestion, and(or) BW gain . Six ruminally and duodenally cannulated beef cows (574 kg), used in a Latin-square trial (Exp . 1), were fed bermudagrass hay without supplementation (control) or with 2.8% whey (low whey, LW), 5.6% whey (high whey, HW), 17.4% ground corn (C), 2.8% whey plus 14.9% corn (C-LW), or 5.6% whey plus 12.4% corn (C-HW) . Supplementing with whey and(or) corn increased ruminal butyrate (8.8, 9.4, 10.0, 9.6, 10.5, and 11.0 mol/100 mol of total VFA for control, LW, HW, C, C-LW, and C-HW, respectively; SE = .20) . Supplements did not affect microbial N flow at the duodenum . Six Holstein steer calves (158 kg) in a Latin square (Exp . 2) consumed bermudagrass hay ad libitum alone (control) or with .075 or .15% BW whey (LW and HW, respectively), .5% BW ground corn (C), or corn-whey mixes made by substituting whey for corn (C-LW and C-HW) . Substituting .15% BW of whey for corn increased (P less than .05) total OM intake slightly (3.99, 3.84, 3.75, 4.11, 4.28, and 4.47 kg for control, LW, HW, C, C-LW, and C-HW, respectively; SE = .10) . In an 84-d randomized block experiment (Exp . 3), 96 beef calves (194 kg) consumed (ad libitum) low-quality bermudagrass hay alone or with C, LW, HW, C-LW, or C-HW supplements.(ABSTRACT TRUNCATED AT 250 WORDS)

J Immunol Methods, 1992 Aug 10, 152(2), 177 - 90
Biological activities of polyethylene-glycol immunoglobulin conjugates . Resistance to enzymatic degradation; Cunningham-Rundles C et al.; Serum IgG has been covalently bonded to polyethylene glycols of either 2000 or 8000 molecular weight to produce immunoglobulin conjugates with 4.4-27.2% of primary amines bonded to polyethylene glycol . Polyethylene glycol immunoglobulin conjugates retain the ability, comparable to native IgG, to bind to a range of protein and microbial antigens, but have a reduced ability to bind to Fc receptors or to fix complement C3 . When 6.8% or more of available primary amines are conjugated, IgG-PEG conjugates are impervious to trypsin, and at 14% or more conjugation, more resistant than native IgG to pepsin and chymotrypsin . We suggest that PEG-Ig conjugates may be useful for the oral treatment of various gastrointestinal diseases in which secretory humoral immunity is insufficient.

J Chromatogr, 1992 Aug 7, 579(1), 85 - 91
Quantitation by gas chromatography with selected-ion monitoring mass spectrometry of "natural" diazepam, N-desmethyldiazepam and oxazepam in normal human serum; Duthel JM et al.; During the past five years, the literature has tended to prove the occurrence of "natural benzodiazepines" in tissues and biological fluids of non-medicated humans . Several have been identified but very few papers deal with their quantitation in biological material . We present here a method for the specific and sensitive measurement of serum levels of diazepam, N-desmethyldiazepam and oxazepam by gas chromatography with selected-ion monitoring mass spectrometry in twenty human volunteers without medication . Diazepam was found over the whole population, in the range 7.3-32.0 pg/ml, identical in males and females . The other two were present in only some individuals (1.0-7.6 pg/ml for N-desmethyldiazepam and 2.0-13.0 pg/ml for oxazepam) . The origin (endogenous, dietary or microbial) of these substances is still to be elucidated.

J Pharm Technol, 1992 Sep-Oct, 8(5), 195 - 7
Potential for microbial contamination of ADD-Vantage admixtures; Hudson TJ et al.; OBJECTIVE: To test for potential bacterial contamination of the ADD-Vantage system when the components are assembled in various hospital environments . STUDY DESIGN: One hundred fifty ADD-Vantage units were assembled by three different people in three separate locations within a hospital . Each person assembled ten units per day; the study spanned five days . After 72 hours of incubation, units were inspected for evidence of contamination . SETTING: ADD-Vantage units were assembled by a pharmacist in a laminar-flow hood, a pharmacy student using the pharmacy counter, and a nurse at a patient's bedside table . Personnel at each site wore their regular work attire . Each person observed handwashing techniques normally used during routine working hours . DATA EXTRACTION: Positive results were sent to the hospital microbiology laboratory for determination of growth type . RESULTS: After 72 hours, none of the systems exhibited microbial growth on visual inspection . No differences in microbial contamination of the ADD-Vantage systems relative to assembly site, day of assembly, or person performing the assembly were observed . The incidence of contamination was calculated at less than seven percent . CONCLUSIONS: There is minimal risk of bacterial contamination when ADD-Vantage systems are compounded either on a pharmacy counter or at a patient's bedside . Larger samples must be studied in order to detect differences in the incidence of contamination among assembly sites.

J Nutr, 1992 Aug, 122(8), 1717 - 25
Abomasal infusion of casein enhances nitrogen retention in somatotropin-treated steers; Houseknecht KL et al.; The effects of bovine somatotropin (bST) administration and abomasal protein infusion on nitrogen metabolism were investigated using four abomasally-cannulated Holstein steers in a 4 x 4 Latin square design . Treatments were factorially arranged to include daily abomasal infusion (water or casein, 0.9 g/kg body wt) and daily bST injection (0 or 200 micrograms/kg body wt) . Each treatment period lasted for 23 d and consisted of an adjustment period (d 1 to 7), casein infusion (d 8 to 23) and bST treatment (d 10 to 23) . Nitrogen metabolism and serum insulin-like growth factor-I (IGF-I) profiles were characterized on d 16-22 . Animals were fed a total mixed diet balanced to achieve 0.75 kg gain/d and supplemented to provide 115% of requirements for crude protein and minerals . Nitrogen retention was increased by casein and bST individually (21 and 33%, respectively) or in combination (75%) . Somatotropin treatment increased the biological value of absorbed N, which was consistent with reductions in plasma urea nitrogen . Circulating IGF-I was increased by bST and was highly correlated (r = 0.73) with N retention . Overall, bST altered requirements so that less absorbed N was required per unit of N retained . However, results also demonstrated that because of limitations in amino acids supplied from microbial and ruminal escape protein in young growing cattle, amino acid supply may limit the magnitude of N retention response to bST under many situations.

Clin Exp Immunol, 1992 Aug, 89(2), 305 - 9
Disease association of antibodies to human and mycobacterial hsp70 and hsp60 stress proteins; Elsaghier A et al.; Structural homology between microbial and human stress proteins has been postulated to be a basis for autoimmunization in chronic inflammatory diseases . Therefore, we estimated by ELISA titration the antibody levels to mycobacterial (M) and human (H) recombinant hsp70 and M-hsp65 heat-shock proteins in sera of patients with Crohn's disease (n = 29), ulcerative colitis (n = 20) and nontuberculous mycobacterial disease of the lungs (n = 20) . Antibodies to H-hsp60, separated by two-dimensional gel electrophoresis, were tested in six sera of each group of patients . In Crohn's disease, antibody titres to the M-hsp65 antigen without detectable H-hsp60 binding were significantly elevated in 52% of the patients . In contrast titres to both M-hsp70 and H-hsp70 were demonstrable and correlated, but increased over control values only in four (14%) patients . The antibody pattern in ulcerative colitis was found to be quite different: anti-H-hsp60 binding was demonstrable in most patients, although anti-M-hsp65 titres were not elevated . Furthermore, 25% of patients had significantly elevated titres to M-hsp70, but not to H-hsp70 . In non-tuberculous mycobacterial pulmonary disease, about 50% of patients had elevated titres to both hsp65 and hsp71 mycobacterial antigens but not to the corresponding human proteins; patients with Mycobacterium xenopi infection had the highest titres in this group . These results demonstrate the existence of distinct disease-associated patterns in the human antibody response to stress protein antigens . However, these data are not sufficient to imply sensitization with mycobacteria in patients with inflammatory bowel diseases, since certain epitopes of heat-shock proteins are shared by several bacterial genera.

Am J Infect Control, 1992 Aug, 20(4), 185 - 91
Isolation gowns: a false sense of security?
Lovitt SA, Nichols RL, Smith JW, Muzik AC, Pearce PF.
BACKGROUND: Isolation gowns have traditionally been used in health care situations to protect against microbial contamination . There is now concern over protection of the health care worker from contamination by patients' blood and body fluids . We quantitatively determined the effectiveness of commercially available isolation gowns against human blood leakage or strike through . METHODS: More than 1200 samples of 11 types of disposable gown and one type of reusable gown (new and washed 40 and 80 times) were tested at five different pressures (0.25 to 2 psi) and six durations (1 second to 2 minutes) by means of an apparatus designed to simulate pressures generated during gown usage . RESULTS: In all studied conditions, testing showed significant differences (p less than 0.0001) in the amount of strike through allowed by the gowns and demonstrated important differences in the gowns' protective capabilities . CONCLUSION: Although traditional thought assumes that isolation gowns protect the wearer from contamination, our data show this belief may provide a false sense of security.

Poult Sci, 1992 Aug, 71(8), 1384 - 90
The effectiveness of ligating or detaching ceca as an alternative to cecectomy; Poppema TF et al.; Cecectomy (the surgical removal of ceca) is a technique that has been used to explore the nutritional and osmoregulatory role of the ceca in domestic fowl and other birds . The operation imposes a high level of physiological stress on a bird . The current study describes the effectiveness of ligating or detaching the ceca in young turkeys as an alternative to complete removal of the organ . Birds with ligated ceca showed less postsurgical depression and initiated feeding and other normal activities sooner than birds with detached ceca . Birds with detached ceca also had a significantly slower rate of weight gain 1 wk after surgery . Both surgically treated groups were more depressed than were sham-operated turkeys . Post-mortem examinations revealed that cecal detachment was more successful in actually separating the ceca from the rectum and in preventing flow of digesta in and out of the ceca . Evidence of growth of cecal stumps that remained attached to the rectum was found following both ligation and detachment . Post-mortem examinations revealed that in four birds both ligated or detached ceca left in the abdominal cavity became enlarged and filled with a dark, pasty, odorous substance . This increase in cecal size and volume of contents with time apparently indicates that some microbial metabolic activity continued in the cecal lumen . If so, this might have negative implications for studies that assume that such ceca are no longer functional.

Scand J Immunol, 1992 Aug, 36(2), 279 - 83
Aberrations in titre and avidity of serum IgM and IgG antibodies to microbial and food antigens in IgA deficiency; Cardinale F et al.; The antibody levels and relative avidity of serum IgM and IgG antibodies against E . coli O antigens, poliovirus type 1 and beta-lactoglobulin were determined with enzyme-linked immunosorbent techniques in IgA deficient (IgAd) patients with frequent respiratory tract infections and healthy IgAd individuals . Healthy individuals with normal immunoglobulin levels served as controls . The IgM antibody levels against the bacterial, viral and food antigens and the IgG antibody levels against the bacterial antigens were significantly higher in the IgAd group with recurrent infections than in the group of healthy IgAd individuals . The symptomatic IgAd group had significantly higher levels of the IgG antibodies against the bacterial antigen, also when compared with controls . In contrast the healthy IgAd individuals had the highest avidities of IgM antibodies to the viral and food antigens . The high avidities of antibodies could be a compensatory host defence mechanism in IgAd . These aberrations may appear as a consequence of increased mucosal exposure in IgAd to antigens such as E . coli or beta-lactoglobulin, but presumably not to poliovirus which is only exceptionally present in the milieux . They could also be a result of the previously suggested dysregulation of antibody responses in IgAd.

J Exp Med, 1992 Aug 1, 176(2), 313 - 25
Desialylation of lysosomal membrane glycoproteins by Trypanosoma cruzi: a role for the surface neuraminidase in facilitating parasite entry into the host cell cytoplasm; Hall BF et al.; Trypanosoma cruzi enters host cells via formation of an acidic vacuole which is subsequently disrupted, allowing the parasite access to the cytoplasm . We show that in an acid environment, release of the parasite surface neuraminidase is enhanced, and this release is likely mediated by a phosphatidylinositol-specific phospholipase C (PIPLC), since antibodies to a carbohydrate epitope (CRD) revealed in glycosylphosphatidylinositol (GPI)-anchored proteins after PIPLC cleavage remove the great majority of the soluble neuraminidase activity from culture supernatants . The neuraminidase is active at acidic pH, and is capable of desialylating known vacuolar constituents, i.e., lysosomal membrane glycoproteins . Parasite escape into the cytoplasm is significantly facilitated in terminal sialylation-defective mutant Lec 2 cells, and enzymatically desialylated membranes are more susceptible to lysis by a parasite hemolysin previously implicated in vacuole membrane rupture . These findings provide evidence that terminal sialylation on carbohydrate moieties contributes to maintaining lysosomal membrane integrity, and indicate a role for a protozoan-derived neuraminidase in facilitating parasite entry into host cells . These observations raise the possibility that other microbial neuraminidases may serve a similar function in acidic intracellular compartments.

AIDS Res Hum Retroviruses, 1992 Aug, 8(8), 1355 - 9
Lymphocytes from some long-term seronegative heterosexual partners of HIV-infected individuals proliferate in response to HIV antigens; Kelker HC et al.; A comparison of the proliferative responses of lymphocytes to human immunodeficiency virus (HIV) antigens from long-term, seronegative heterosexual partners of HIV-infected subjects, from normal unexposed controls and from healthy seropositive heterosexual partners or seropositive, asymptomatic men, reveals that lymphocytes from healthy seropositive individuals with strong proliferative responses to recall, microbial antigens respond only minimally to HIV proteins or envelope peptides, and that even these low responses do not occur in all individuals . If the frequency of responses to several HIV antigens are analyzed, lymphocytes from both HIV-exposed seropositive and seronegative partners of infected individuals proliferate to HIV antigens to a greater degree than lymphocytes from unexposed, normal control individuals . Although lymphocytes from seropositive partners proliferate to a greater degree than those from seronegative partners, the latter are more similar to seropositive partners than they are to normal controls . This observation suggests that these seronegative partners may have become sensitized to HIV antigens through sexual exposure but without infection, and/or that the presence or development of these small immune responses in some individuals might be associated with a failure to become infected.

Vnitr Lek, 1992 Aug, 38(8), 764 - 8
The effect of Hylak drops on symptomatology in persons with irritable bowel syndrome}; Zboril V et al.; The authors present an account on the therapeutic effect of Hylak drops of Merckle Co . in patients with irritable bowel syndrome . They assume that in the pathophysiological mechanism of the disease an important part is played by intestinal dysmicrobia . After two weeks' administration Hylak, 3 x 40 drops, they recorded in 20 patients with the exception of one female patient (where ex post lactose intolerance was revealed which is a contraindication of this treatment), partial or complete regression of subjective complaints in particular as regards intestinal discomfort and the number of imperative bowel movements . As to objective indicators, they proved changes in the pH of faeces and qualitative as well as quantitative changes of the microbial spectrum in faeces.

Int J Immunopharmacol, 1992 Aug, 14(6), 1061 - 8
In vitro activation of murine peritoneal exudate cells (PEC) and peritoneal macrophages by ST 789; Foresta P et al.; ST 789 is a new synthetic compound characterized by an amino acidic group joined to the N9 position of the hypoxanthine ring, which has been shown recently to have immunomodulating properties and minimal toxicity . The drug has been reported to protect immunosuppressed mice from microbial infections and tumour growth, and to restore the mitogen-induced proliferation of splenocytes from immunosuppressed young mice . In this study, we show that in vitro addition of ST 789 is able to markedly augment the sheep red blood cells (SRBC) phagocytosis by PEC, and to potentiate the cytotoxic activity of peritoneal exudate (PE) macrophages (M phi) vs the L-M tumour cell line . We also found that ST 789 enhanced the rIFN-gamma-induced NO2- release from cultured PE M phi . Similarly, in vitro addition of ST 789 to the latter cultures significantly increased the production of interleukin 1 (IL-1) and tumour necrosis factor (TNF) induced by lipopolysaccharide (LPS) . These studies demonstrate that ST 789 is a potent phagocyte activator for the induction of cytokine release, phagocytosis and cytotoxic activity against tumour cells in vitro.

Acta Crystallogr B, 1992 Aug 1, 48 ( Pt 4), 341 - 56
Folding, aggregation and molecular recognition in peptides; Karle IL; In past years, most of the X-ray structure determinations of oligopeptides were for cyclic peptides or for short linear peptides . Longer peptides usually presented many difficulties in obtaining suitable crystals since the molecules are intrinsically very flexible . More recently, it has been appreciated that the aminoisobutyric acid residue (Aib), which occurs naturally in many peptides of microbial origin, initiates helix folding . Several score of 7- to 15-residue linear peptides containing Aib have been synthesized, crystallized and had their structures determined to high resolution . Many of the peptide structures have been determined in more than one crystalline form . These peptide structures have yielded a plethora of information on types of helices, modes of hydration, water penetration into helical backbones, helices bent by Pro residues, parallel and antiparallel association of helices, effects of Leu residues on association of peptides, an example of a zipper assembly by side chains, and an example of a possible ion channel with a gating mechanism.

Oral Microbiol Immunol, 1992 Aug, 7(4), 244 - 8
Actinobacillus actinomycetemcomitans, Capnocytophaga and Porphyromonas gingivalis in subgingival plaque of adolescents with Down's syndrome; Barr-Agholme M et al.; Levels of Actinobacillus actinomycetemcomitans, Capnocytophaga and Porphyromonas gingivalis were determined in subgingival plaque samples from 37 adolescents with Down's syndrome and 37 healthy controls matched with respect to age and sex . Gingival inflammation, supra- and subgingival calculus, periodontal pockets ( > 4 mm) and alveolar bone loss were registered . Alveolar bone loss was more frequent in Down's syndrome subjects (32%) than in the controls (3%) . A . actinomycetemcomitans was detected in the subgingival plaque in 35% of the Down's syndrome adolescents and in 5% of the controls . On site level, A . actinomycetemcomitans and Capnocytophaga were more frequent in the subgingival plaque samples of Down's syndrome children than in those of controls . Comparing Down's syndrome subjects positive or negative for A . actinomycetemcomitans and Capnocytophaga, no significant differences were found in terms of gingival inflammation, periodontal pockets ( > 4 mm) or number of sites with alveolar bone loss . The results indicate an altered microbial composition of the subgingival plaque of Down's syndrome subjects compared with healthy controls, with higher frequency of A . actinomycetemcomitans.

Kidney Int, 1992 Aug, 42(2), 341 - 53
Extrarenal cytokines modulate the glomerular response to IgA immune complexes; Montinaro V et al.; Clinical episodes of IgA nephropathy coincide recurrently with microbial infections . Cytokines produced during such infections may play a role in the pathogenesis of IgA-associated glomerulonephritis . To test this hypothesis, we examined the influence of passively administered proinflammatory cytokines (IL-1, IFN-gamma and IL-6) on the development of glomerulonephritis in an experimental model of IgA nephropathy . Glomerular IgA immune deposits were induced in mice by administration of IgA anti-phosphorylcholine (PC) with either a PC-containing carbohydrate antigen of Pneumococcal C polysaccharide (PnC) or a protein antigen of PC-conjugated bovine serum albumin (PC-BSA) . The effect of IL-1 on the IgA-PC-BSA induced glomerular changes resulted in an increase of mesangial hypercellularity that was associated with mild proteinuria and hematuria . Mice treated with IL-1 and IgA-PnC developed diffuse proliferative glomerulonephritis with proteinuria and hematuria . In contrast, IL-6 treatment with IgA-PC-BSA of IgA-PnC failed to exert any significant renal effect . The combination of IL-6 and IL-1, however, intensified the mesangial hypercellularity of the IgA-PC-BSA, and induced severe proliferative glomerulonephritis with inflammatory monocytes and neutrophils infiltrates in the IgA-PnC treated mice . These glomerular changes were also accompanied by increased proteinuria and hematuria . Similarly, the combination of IFN with IL-1 produced histologic changes and compromised renal function more than IFN or IL-1 exerted independently . These results suggest that extrarenal cytokines influence the renal response to IgA immune deposits . We also conclude that a synergy of multiple cytokines and nephritogenic antigens immobilized in glomerular IgA immune deposits may lead to rapid progression of IgA-associated glomerulonephritis.

J Dairy Sci, 1992 Aug, 75(8), 2215 - 25
Protein digestion and intestinal amino acids in dairy cows fed fresh Lolium perenne with different nitrogen contents; Van Vuuren AM et al.; An experiment was carried out to study digestion and intestinal AA in three ruminally and duodenally cannulated, lactating cows fed freshly cut grass (Lolium perenne) fertilized with 500 and 275 kg of N/ha per yr, respectively . High N grass was fed in June and October, and low N grass was offered in July and September . Composite samples of the grass fed in each period also were tested for in situ degradation of OM, CP, and NDF . When low N grass was fed, the digestibilities of OM and CP were lower than when high N grass was fed . On low N grass, the duodenal N flow expressed per unit of N intake was higher, although the flow of AA N on low N grass was reduced in September, mainly because of reduced microbial protein synthesis from slower OM degradation of low N grass . Duodenal N flow per unit of N intake was related negatively to the N:OM ratio of the diet . The rate of N fertilization had no effect on ruminal OM and NDF turnover rates . Turnover and passage rates in this experiment were not different from reported data on cows on winter rations with similar DMI.

Genitourin Med, 1992 Aug, 68(4), 245 - 8
Sexual behaviour in Zulu men and women with genital ulcer disease; O'Farrell N et al.; OBJECTIVE--To investigate patterns of sexual behaviour in men and women with genital ulcer disease (GUD) and their relevance to HIV-1 transmission . METHODS--A sexual behaviour questionnaire was administered by the same interviewer to all participants who were also entered into a study of the microbial aetiology of GUD . SETTING--City Health Sexually Transmitted Diseases Clinic, King Edward VIII Hospital, Durban, South Africa . PARTICIPANTS--100 Zulu men and 100 Zulu women . RESULTS--36 (%) of men and 36 (%) of women had continued with sexual intercourse despite GUD . Patients with donovanosis and secondary syphilis were more likely than those with other causes of GUD to have intercourse despite ulcers . During swab collection bleeding was observed from ulcers in 59 women and 26 men . Prostitutes were not identified and were rarely named as source contacts . Men had more sexual partners (190) than women (122) during the previous three months . Condom use was minimal . Men who migrated between urban and rural areas appeared to have the most sexual partners . Urban women had more partners than women from rural areas . CONCLUSIONS--Men and women with GUD are practising riskful sexual behaviour and could benefit from behaviour modification programmes . In this community men who travel between urban and rural areas and who present late with GUD that bleeds easily are probably the most important high-frequency HIV transmitter core group . A significant potential risk of blood to blood contact during sexual intercourse exists in patients with GUDPIP: This study sought to investigate the patterns of sexual behavior in men and women with genital ulcer disease (GUD) and their relevance to HIV-1 transmission . Participants were 100 Zulu men and 100 Zulu women at the City Health Sexually Transmitted Disease Clinic . King Edward VIII Hospital, in Durban, South Africa; a sexual behavior questionnaire was administered by the same interviewer to all of the above participants who were also included in a study of the microbial etiology of GUD . 36% of the men and 36% of the women continued with sexual intercourse despite GUD . Patients with donovanosis and secondary syphilis were more likely than those with other causes for their GUD to have intercourse despite ulcers . During swab collection, bleeding was observed from ulcers in 59 women and 26 men . Prostitutes were not identified and were rarely named as source contacts . Men had more sexual partner (190) than women (122) during the previous 3 months . Condom use was minimal . Men who migrated between urban and rural areas appeared to have the most sexual partners . Urban women had more partners than women from rural areas . The authors concluded that men and women with GUD are practicing risky sexual behavior and could benefit from behavior modification programs . In this community, men who travel between rural and urban areas and who present late with GUD that bleeds easily are probably the most important high-frequency HIV transmitter core group . A significant potential risk of blood-to-blood contact during sexual intercourse exists in patients with GUD . author's modified

Zentralbl Hyg Umweltmed, 1992 Aug, 193(2), 150 - 9
Infectious risk of replacing venous catheters by the guide-wire technique; Bach A et al.; During the perioperative period cardiac surgical patients are often monitored by pulmonary artery (PA) catheters . This catheter, which is floated through the right heart into the pulmonary artery, enables the intensivist to measure and calculate indices of myocardial performance . After a variable period of time this invasive monitoring can often be abandoned following cardiovascular stabilization in these patients, but patients usually still require a central venous (CV) access for diagnostic and therapeutic purposes . To place this CV catheter either a de novo puncture at a new site or a guide-wire change at the existing exit site through the PA catheter in place can be performed . Each de novo puncture is associated with a risk of traumatising internal vessels or organs . In contrast, guide-wire change avoids this risk but inherits a potential risk of transferring bacteria by manipulation of contaminated lines . Our study included 159 consecutive cardiac surgical patients in whom PA monitoring was established preoperatively and terminated within a period of up to 72 hours postoperatively . At random the PA catheter was replaced by a CV line either by de novo puncture or by guide-wire change . All CV lines were left in place for 7 days according to standard practice in our intensive care unit (ICU) . After removal of CV catheters all catheter tips were cultured semiquantitatively by rollplate technique according to Maki (26) and subsequent immersion broth culture . A positive culture was defined as growth of one up to 15 colonies on the agar-plate or any microbial growth in the broth . A significant colonization was assumed in catheters yielding more than 15 colony forming units (cfu) on the blood agar plate (26) . Our results show a significant risk of colonization and catheter-related infection associated with the guide-wire technique as opposed to the de novo puncture . The figures for relevant colonization were 33.3% in the guide-wire group as opposed to 10.5% in the de novo group . However, this difference was noted only in the subgroup in which replacement of PA catheters by CV catheters was performed beyond 48 h after initial insertion of PA catheters . Within the time intervals of 24 and 25 to 48 h, respectively, we could not detect any significant difference between groups.

Immunol Lett, 1992 Aug, 33(3), 307 - 14
The antigen-specific induction of normal human lymphocytes in vitro is down-regulated by a conserved HIV p24 epitope; Luzzati AL et al.; Synthetic peptides containing amino acid sequence 218-238 of the core protein p24 of human immunodeficiency virus type 1 (HIV-1) and progressively shorter sequences at its C-terminus, were tested for their effect on antigen dependent in vitro responses of peripheral blood lymphocytes (PBL) from normal human donors . A peptide as short as 7 amino acids, corresponding to a highly conserved sequence, was able to inhibit in a dose-dependent manner the induction of a specific primary antibody response to the sheep red cell (SRC) antigen, as well as the proliferative response to recall microbial antigens . The results of this study constitute additional evidence of the immunoinhibitory effects of HIV components and may help to unravel some of the pathogenic mechanisms of AIDS . Moreover, they are of potential relevance for the development of immunoprophylactic and therapeutic strategies.

J Biochem (Tokyo), 1992 Aug, 112(2), 229 - 34
Cross-linking of contractile proteins from skeletal muscle by treatment with microbial transglutaminase; Huang YP et al.; The action on muscle proteins of microbial transglutaminase (MTGase), which catalyzes the formation of a "zero-length" covalent cross-link between glutamine and lysine residues in peptides, was studied in order to define a basis for future application of MTGase cross-linking to the study of muscle protein interaction . We examined the cross-linking of skeletal muscle myosin, myosin subfragments, actin, and myofibrils by treatment with MTGase and the possible side-effects of the cross-linking on the enzymic activity of myosin, and found that the rod portions of myosin in myosin filaments were quickly cross-linked to each other by the action of MTGase, but myosin subfragment 1 was not cross-linked to actin . The MgATPase activities at 0.5 M KCl of myosin, heavy meromyosin, subfragment 1, and subfragment 1-actin were not significantly affected by the MTGase reaction . A very small fraction of the head portion of heavy meromyosin was cross-linked to actin in their rigor complexes by MTGase, and the ATPase activity at 0.5 M KCl of the cross-linked heavy meromyosin-actin complexes was slightly enhanced.

Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1992 Aug, 25(3), 129 - 37
Microbial production of citric acid from salad oil; Pan TM et al.; Strain CCU-U2-N4-41 was derived from a wild strain of yeast CCU-087 . This strain can produce large amounts of citric acid from salad oil . The optimal medium for citric acid production is one liter of medium containing salad oil 100 g, yeast extract 2.0 g, CH3COONH4 3.0 g, KH2PO4 5.0 g, MgSO4 500 ppm, 1 ppm each of MnSO(4).5 H2O and CuSO(4).2 H2O, pH: 7.0 . The optimal culture conditions are: temperature: 28 degrees C; agitation: 110 rpm; 100 mL medium in 500-mL Hinton flask; 1.5% CaCO3 added after 12 hr incubation . With 96 hr cultivation 71.2 g/L of citric acid can be produced . Citric acid produced was compared with authentic citric acid by melting point determination, IR, NMR and Mass . From the spectra, it was found that they were identical.

J Biochem (Tokyo), 1992 Aug, 112(2), 299 - 302
Inhibition of CDP-DG: inositol transferase by inostamycin; Imoto M et al.; Inostamycin, a novel microbial secondary metabolite, inhibited {3H}inositol and 32P1 incorporation into phosphatidylinositol (PtdIns) induced by epidermal growth factor (EGF) in cultured A431 cells, the IC50 being 0.5 micrograms/ml, without inhibiting macromolecular synthesis . The drug inhibited cellular inositol phosphate formation only when it was added at the same time as labeled inositol . It was found to inhibit in vitro CDP-DG:inositol transferase activity of the A431 cell membrane, the IC50 being about 0.02 micrograms/ml . It did not inhibit tyrosine kinase, PtdIns phospholipase C, or PtdIns kinase . Therefore, inhibition of PtdIns turnover by inostamycin must be due to the inhibition of CDP-DG:inositol transferase . Thus, inostamycin is a novel inhibitor of CDP-DG:inositol transferase.

Proc Natl Acad Sci U S A, 1992 Aug 1, 89(15), 6901 - 5
Intracellular neutralization of virus by immunoglobulin A antibodies; Mazanec MB et al.; IgA is thought to neutralize viruses at the epithelial surface of mucous membranes by preventing their attachment . Since IgA, a polymeric immunoglobulin, is transported through the lining of epithelial cells by the polymeric-immunoglobulin receptor and since viruses are obligate intracellular parasites, we hypothesized that IgA antibodies may also interfere with viral replication by binding to newly synthesized viral proteins within infected cells . Polarized monolayers of Madin-Darby canine kidney epithelial cells expressing the polymeric-immunoglobulin receptor were infected on the apical surface with Sendai virus . Anti-Sendai virus IgA monoclonal antibody delivered from the basolateral surface colocalized with viral protein within the cell, as documented by immunofluorescence . More importantly, anti-viral IgA reduced virus titers greater than 1000-fold (P less than 0.0001) in apical supernatants and greater than 10-fold (P less than 0.0001) in cell lysates from monolayers treated with anti-viral IgA compared with those treated with either anti-viral IgG or an irrelevant IgA monoclonal antibody . We believe that the differences in viral titers between cell layers treated with specific IgA, which enters the epithelial cell by binding to the polymeric-immunoglobulin receptor, and those treated with specific IgG, which does not enter the cells, or irrelevant IgA indicate that specific intracellular IgA antibodies can inhibit viral replication . Thus, in addition to the classical role of humoral antibodies in extracellular defense, IgA antibody may be able to neutralize microbial pathogens intracellularly, giving IgA a role in host defense that has traditionally been reserved for cell-mediated immunity.

Nutr Clin Pract, 1992 Aug, 7(4), 187 - 96
Intravenous fat emulsions in clinical practice; Warshawsky KY; The use of intravenous fat emulsions has become an integral part of the provision of parenteral nutrition . In the past, this was achieved by the administration of lipids separately from the dextrose-amino acid base solution . More recently, lipids have been admixed along with the dextrose-amino acid formula as a total nutrient admixture (TNA) . This article discusses the advantages and disadvantages of TNAs, the factors that affect the stability of emulsions, the potential for microbial growth in TNAs, and guidelines for the compounding of TNAs.

Biochem Biophys Res Commun, 1992 Jul 31, 186(2), 775 - 81
Evaluation of nitrite production by human monocyte-derived macrophages; Padgett EL et al.; Reactive nitrogen intermediates are important in the anti-tumor and anti-microbial activities of rodent macrophages, but it is not known whether this is the case for human macrophages . In the present study, nitrite concentrations in vitro were used as an indicator of reactive nitrogen intermediate production by mouse, rat, and human macrophages . Human macrophages derived by culturing peripheral blood monocytes did not consistently produce detectable nitrite levels in response to any stimulus examined . Human macrophages were viable and metabolically active as indicated by the MTT assay, and their respiratory burst response to phorbol myristate acetate was increased following incubation with Interferon-gamma, as expected for typical macrophages . In contrast, rat or mouse peritoneal macrophages produced nitrite concentrations of approximately 20-100 microM in response to lipopolysaccharide, Interferon-gamma, or both . These results demonstrate substantial differences in the production of nitrites by rodent and human macrophages . Because of the heterogeneity among macrophage populations, these findings may not be applicable to all human macrophage populations, but they suggest a need for caution in extrapolating from rodent studies regarding the role of reactive nitrogen intermediates in anti-tumor or anti-microbial functions of human macrophages.

J Biol Chem, 1992 Jul 25, 267(21), 14884 - 92
The ES-242s, novel N-methyl-D-aspartate antagonists of microbial origin, interact with both the neurotransmitter recognition site and the ion channel domain; Toki S et al.; ES-242-1 approximately 5 are novel microbial bioxanthracenes which do not contain nitrogen . The ES-242s inhibited the binding of {3H}TCP and {3H}CGS19755 to the N-methyl-D-aspartate (NMDA) receptor complex . They had no effect on the binding of the specific ligands for the non-NMDA receptor . The biochemical and pharmacological properties of ES-242-1 were fully examined since it is the most potent of the five compounds . ES-242-1 is highly specific for the NMDA receptor; it has no effect on other receptors . Kinetic analyses indicated that ES-242-1 inhibited the binding of {3H}TCP and {3H}CGS19755 in a competitive manner, respectively, suggesting that ES-242-1 interacts with both the transmitter recognition site and the channel domain . ES-242-1 selectively inhibited NMDA-induced Ca2+ influx in primary cultures of mouse hippocampal neurons . ES-242-1 also specifically blocked the increase in cyclic GMP accumulation induced by NMDA or L-glutamate in rat cerebellar slices . In a concentration range of 0.1-1.0 microM, ES-242-1 was as potent as MK-801 in preventing glutamate-induced neurotoxicity in primary cultures of mouse hippocampal neurons . These results show that ES-242-1 is a potent and specific antagonist for the NMDA receptor . The antagonistic properties of the ES-242s appear to be due to a novel mechanism of action at the NMDA receptor.

FEBS Lett, 1992 Jul 20, 306(2-3), 189 - 92
Crystal and molecular structure of RNase Rh, a new class of microbial ribonuclease from Rhizopus niveus; Kurihara H et al.; The crystal structure of RNase Rh, a new class of microbial ribonuclease from Rhizopus niveus, has been determined at 2.5 A resolution by the multiple isomorphous replacement method . The crystal structure was refined by simulated annealing with molecular dynamics . The current crystallographic R-factor is 0.200 in the 10-2.5 A resolution range . The molecular structure which is completely different from the known structures of RNase A and RNase T1 consists of six alpha-helices and seven beta-strands, belonging to the alpha+beta type structure . Two histidine and one glutamic acid residues which were predicted as the most probably functional residues by chemical modification studies are found to be clustered . The steric nature of the active site taken together with the relevant site-directed mutagenesis experiments (Irie et al.) indicates that: (i) the two histidine residues are the general acid and base; and (ii) an aspartic acid residue plays a role of recognizing adenine moiety of the substrate.

Gene, 1992 Jul 15, 116(2), 119 - 27
Purification and characterization of wheat alpha-gliadin synthesized in the yeast, Saccharomyces cerevisiae; Blechl AE et al.; The development of efficient methods for production and purification of plant seed storage proteins in heterologous microbial hosts would facilitate structure-function studies of these proteins . This report describes such methods applied to the production and isolation of wheat alpha-gliadin, a prolamine-type seed storage protein, from Saccharomyces cerevisiae . Beginning with the vector, growth conditions, and extraction methods of Neill et al . {Gene 55 (1987) 303-317}, we implemented several improvements to increase the yields of alpha-gliadin per volume of yeast cell culture . The CYCl::Gli-A2-Y transcriptional fusion vector, pAY31 (Neill et al., 1987), was modified by replacing the ARS1 region of replication with that of the 2 mu plasmid of yeast . We formulated a new medium, a derivative of synthetic defined (SD) medium supplemented with several nitrogen sources, that allows both selection for maintenance of plasmids and growth to high cell densities . Stationary phase cultures of cells bearing the modified expression vector, and grown in this medium with glycerol and lactate as carbon sources, contain significantly higher levels of alpha-gliadin than log-phase cultures grown in SD glucose . Sonication in 80% ethanol selectively and efficiently extracts the alpha-gliadin from cell pellets of small- or large-scale cultures, allowing the purification of several hundred micrograms of the wheat protein per liter in just a few high-yield steps . The alpha-gliadin isolated from yeast elutes at the same position in HPLC as the A-gliadin fraction purified from wheat flour . N-terminal amino acid (aa) sequencing reveals that the signal peptide is removed from the gliadin precursor in yeast cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Ophthalmology, 1992 Jul, 99(7), 1153 - 60; discussion 1160-1
Retinal manifestations of ocular lymphoma (reticulum cell sarcoma); Ridley ME et al.; BACKGROUND: Diagnosis and treatment of ocular large cell lymphoma may lessen visual loss and prolong life . Although reports in the literature have described retinal infiltrates in eyes with large cell lymphoma, they have focused on the more prominent vitreous and subretinal pigment epithelial findings . Eyes with retinal infiltrates and hemorrhagic retinal necrosis are usually believed to harbor a microbial infection . The authors describe 5 patients, aged 57 to 85 years, with ocular lymphoma in whom the most prominent initial findings were in the retina . METHOD: Patients presented with findings suggestive of an infectious retinal necrosis . When the initial therapy failed, investigators performed a vitreous biopsy . Two patients had a concomitant retinal biopsy . Radiation therapy was given to four patients . RESULTS: All five patients had vitreous cells . Three patients had prominent perivascular exudate . Four patients had grayish-white retinal infiltrates, and three patients had associated retinal hemorrhage . Three patients had subretinal small white spots . An edematous thickened retina developed in three patients, and hemorrhagic retinal necrosis developed in three patients . The initial diagnosis was believed to be acute retinal necrosis (ARN) in three patients, toxoplasmosis in one patient, and frosted branch angiitis in one patient . Vitreous biopsy was positive in two patients but negative in three patients . In two of these three patients, the diagnosis was established by retinal biopsy . CONCLUSION: Ocular lymphoma should be considered in the differential diagnosis of retinal vasculitis or necrotizing retinitis in a middle-aged or older patient . Retinal biopsy may be helpful in establishing the diagnosis.

Curr Opin Ophthalmol, 1992 Aug, 3(4), 466 - 72
Contact lenses and corneal shields; Lang GE; Contact lenses are widely used all over the world . If fitted and handled properly, contact lenses can be good cosmetic and therapeutic tools . In this review, the different indications for contact lens wear are discussed . Contact lenses can also lead to serious problems . Tear film and morphologic alterations of the cornea, as well as corneal infections of microbial origin, are reviewed . Collagen bandage lenses have been used for some time in the treatment of corneal epithelial defects . Currently, these lenses are being tested as drug delivery systems, especially for use with poorly penetrating drugs, in serious infections of the cornea.

Lancet, 1992 Jul 4, 340(8810), 5 - 9
Double-blind study of selective decontamination of the digestive tract in intensive care; Hammond JM et al.; Selective decontamination of the digestive tract (SDD), by means of non-absorbable antibiotics, to prevent infection in intensive-care units (ICUs) remains controversial; there is evidence that the regimen reduces the incidence of secondary infection, but no convincing reduction in morbidity or mortality has been shown and the costs and effect on microbial resistance patterns need further study . In a double-blind, placebo-controlled trial, we have tried to find out whether SDD should be used routinely in all ICU patients at high risk of secondary infection . All patients admitted to the ICU who were thought likely to stay in the unit for at least 5 days and to need intubation for longer than 48 h were enrolled and randomly allocated to groups receiving placebo or SDD (amphotericin, colistin, and tobramycin applied to the oropharynx and enterally); all patients received intravenous cefotaxime for 72 h . Of 322 patients randomised, 83 were withdrawn (80 ICU stay or duration of intubation too short, 3 protocol violations) . 239 medical, trauma, and surgical patients completed the trial period (114 SDD, 125 placebo) . There were no differences between SDD and placebo groups in incidence of infection (30 {26%} vs 43 {34%} patients; p = 0.22), duration of ICU stay (mean 16.2 {14.3} vs 16.8 {12.3} days), hospital stay (29.9 {SD 25.0} vs 31.9 {22.2} days), or mortality (21 {18%} vs 21 {17%}) . SDD substantially increased the costs of intensive care . Mechanisms other than bacterial colonisation of the gut may bring about substantial numbers of secondary infections in ICUs . Routine use of SDD in multidisciplinary ICUs cannot be recommended.

Regul Pept, 1992 Jul 2, 40(1), 1 - 12
Effect of chymotrypsin on human cholecystokinin release: use of clostripain in the validation of a new radioimmunoassay; Beardshall K et al.; We have developed and validated a new radioimmunoassay for cholecystokinin . In order to establish that the antiserum binds large and small forms of CCK to an equal extent, we used the microbial enzyme clostripain, which cleaves large forms of CCK yielding CCK 8 . Cleavage by clostripain of synthetic and purified forms of CCK, and CCK extracted at from human jejunum and CCK in human plasma was found not to affect immunoactivity, indicating that the antiserum reacts similarly with all forms of CCK . There is controversy over whether intraduodenal trypsin inhibits release of CCK in man . We used our radioimmunoassay to investigate whether chymotrypsin, rather than trypsin, could be the major mediator of negative feedback control of CCK release . Six normal subjects received an intraduodenal infusion of L-phenylalanine and L-tryptophan on two occasions, with the addition of either 1 g/l bovine chymotrypsin or 1 g/l albumin . Plasma CCK concentrations rose in response to the amino acid infusion, but were not affected by the addition of chymotrypsin, indicating that this enzyme is not a mediator of CCK feedback regulation in man.

J Am Vet Med Assoc, 1992 Jul 1, 201(1), 125 - 8
Meningitis in neonatal calves: 32 cases (1983-1990); Green SL et al.; Case records of 32 neonatal calves with the antemortem diagnosis of meningitis were reviewed . Mean age at admission was 6 days (range, 11 hours to 30 days), and the most common concurrent clinical problem was diarrhea (16/32) . Twenty-seven of the calves were available for necropsy . At postmortem, there was evidence of septicemia in 22 (81%) of these calves . Escherichia coli was the organism most frequently isolated (11/16; 69%) from the CNS . The major clinical signs of CNS disturbance observed over the course of hospitalization were lethargy, recumbency, anorexia, loss of suckle reflex, and coma . Leukocytosis and a left shift was evident in 11 of 15 (73%) calves . Concurrent metabolic problems that could have aggravated the CNS disturbance included hyperkalemia and respiratory acidosis . Analysis cerebrospinal of fluid from 22 of the calves, revealed pleocytosis, xanthochromia, turbidity, and high total protein concentration . Cytologically, neutrophils predominated in the CSF in calves with acute disease . Mononuclear cells dominated in calves with chronic disease . Microscopically, bacteria were evident in 10 of 22 (45%) of the antemortem CSF samples and bacteria were isolated from slightly more than half (11/19) of the specimens subjected to microbial culturing . Escherichia coli was the agent most frequently isolated from the CSF . Two of the 9 E coli isolates were resistant to trimethoprim potentiated sulfonamide drugs and all (4/4) of the CSF E coli isolates tested for susceptibility to triple-sulfonamide drugs were resistant . Twenty-seven of the 32 calves died or were euthanatized within 2.43 days after hospitalization.(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1992 Jul, 58(7), 2168 - 75
Structure, organization, and transcription of a cellobiohydrolase gene cluster from Phanerochaete chrysosporium; Covert SF et al.; Restriction mapping and sequence analysis of cosmid clones revealed a cluster of three cellobiohydrolase genes in Phanerochaete chrysosporium . P . chrysosporium cbh1-1 and cbh1-2 are separated by only 750 bp and are located approximately 14 kb upstream from a cellulase gene previously cloned from P . chrysosporium (P . Sims, C . James, and P . Broda, Gene 74:411-422, 1988) . Within a well-conserved region, the deduced amino acid sequences of P . chrysosporium cbh1-1 and cbh1-2 are, respectively, 80 and 69% homologous to that of the Trichoderma reesei cellobiohydrolase I gene . The conserved cellulose-binding domain typical of microbial cellulases is absent from cbh1-1 . Transcript levels of the three P . chrysosporium genes varied substantially, depending on culture conditions . cbh1-1 and cbh1-2 were not induced in the presence of cellulose, nor did they appear to be subject to glucose repression . Therefore, aspects of the chromosomal organization, structure, and transcription of these genes are unlike those of any previously described cellulase genes.

Proc Natl Acad Sci U S A, 1992 Jul 1, 89(13), 6045 - 9
The deep, hot biosphere; Gold T; There are strong indications that microbial life is widespread at depth in the crust of the Earth, just as such life has been identified in numerous ocean vents . This life is not dependent on solar energy and photosynthesis for its primary energy supply, and it is essentially independent of the surface circumstances . Its energy supply comes from chemical sources, due to fluids that migrate upward from deeper levels in the Earth . In mass and volume it may be comparable with all surface life . Such microbial life may account for the presence of biological molecules in all carbonaceous materials in the outer crust, and the inference that these materials must have derived from biological deposits accumulated at the surface is therefore not necessarily valid . Subsurface life may be widespread among the planetary bodies of our solar system, since many of them have equally suitable conditions below, while having totally inhospitable surfaces . One may even speculate that such life may be widely disseminated in the universe, since planetary type bodies with similar subsurface conditions may be common as solitary objects in space, as well as in other solar-type systems.

J Dent Res, 1992 Jul, 71(7), 1457 - 8
New agents in the chemical control of plaque and gingivitis--reaction paper; Van Dyke TE; The papers of Drs . Christersson, Marsh, Cummins, and Ciancio focus on the issues and problems associated with the efficacious delivery of chemical agents intended to control plaque and gingivitis . The infectious nature of periodontal disease, the importance of oral microbial ecology, the success of triclosan formulations, and the review of our current knowledge based upon clinical trials are emphasized.

Plant Mol Biol, 1992 Jul, 19(4), 555 - 61
Characterisation of a wound-induced transcript from the monocot asparagus that shares similarity with a class of intracellular pathogenesis-related (PR) proteins; Warner SA et al.; We report the isolation and characterisation of a wound-induced cDNA designated AoPR1 from a suspension of mesophyll cells that had been mechanically isolated from cladodes of light-grown Asparagus officinalis seedlings by grinding in a mortar and pestle . The transcript abundance is up-regulated following cell separation and in chopped mesocotyl tissue from dark-grown seedlings . The expression of AoPR1 was shown by northern analysis to be located around the site of damage . Sequence analysis revealed similarity between the predicted AoPR1 polypeptide and bean PvPR1 and PvPR2 proteins, the potato pSTH2 protein, the pea PI49 protein, the parsley PcPR1-1 protein and a major pollen allergen from birch (BetvI) . These transcripts have been shown to be induced in response to microbial attack or fungal elicitation . To our knowledge, this is the first example of a monocot cDNA belonging to this class of intracellular pathogenesis-related proteins (IPRs).

Eur J Immunol, 1992 Jul, 22(7), 1701 - 6
A V region-connected autoreactive subfraction of normal human serum immunoglobulin G; Dietrich G et al.; Mouse and human natural IgM autoantibodies have been shown to be polyreactive and "connected" through V region-dependent interactions . In the present study, we have identified a connected subfraction of normal human serum IgG by using affinity chromatography of F(ab')2 fragments of pooled IgG (IVIg) or of IgG from a single donor on Sepharose-bound F(ab')2 fragments of the same source of IgG . The connected fraction of IgG exhibited a high content of autoantibodies directed against a wide panel of evolutionarily conserved self antigens and of self antigens that may be targets of autoantibodies in autoimmune diseases . Connected IgG also contained higher amounts of antibodies directed against commonly encountered microbial antigens than unfractionated IgG . The connected fraction did not, however, differ from unchromatographed IgG nor from non-connected IgG in its content of antibodies to vaccinal antigens and to distant foreign antigens . Thus, in humans as in mice, connectivity is a prominent feature of autoantibodies . Our observations are suggestive of a tight control by IgG of the expressed autoreactive repertoire in healthy individuals and strengthen the concept that the therapeutic infusion of pooled normal IgG (IVIg) may be effective in autoimmune diseases by bringing to patients normal regulatory components of the immunoglobulin network.

Mutagenesis, 1992 Jul, 7(4), 235 - 41
Organ-specific distribution of genotoxic effects in mice exposed to cooked food mutagens; Knasmuller S et al.; The induction of organ-specific genotoxic effects of five cooked food mutagens in Swiss albino mice was investigated in microbial animal-mediated assays . The indicator of the induction of DNA damage was a pair of Escherichia coli K12 strains, differing vastly in repair capacity (uvrB/recA versus uvr+/rec+) . All compounds gave positive results in the tested dose range between 2.5 and 40 mg/kg body weight (i.p . administration, exposure time 120 min) . 2-amino-3,4-dimethylimidazo{4,5-f}quinoline (MeIQ) and 2-amino-3-methylimidazo{4,5-f}quinoline (IQ) were slightly more genotoxic than 2-amino-3,8-dimethylimidazo{4,5-f}quinoline (MeIQx), 3-amino-1-methyl-5H-pyrido{4,3-b}indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimidazo{4,5-b}pyridine (PhIP) which caused similar effects . When the compounds were administered orally, higher doses were required to induce repairable DNA damage . The pattern of organ-specific effects was essentially similar for all compounds; genotoxicity was most pronounced in livers and lungs, whereas in kidneys, spleen and testes comparatively lower effects were measured . The activity of PhIP, MeIQ and IQ in the blood was similar to that observed in the liver . The results obtained in vivo were compared with data gained in vitro with subcellular organ fractions . Our findings indicate the following . (i) The concentrations required to induce repairable DNA damage in microbial animal-mediated assays are substantially higher than might be expected on the basis of the liquid suspension tests . (ii) The ranking order of the genotoxicity of the various compounds in vitro is similar to that measured in vivo, but the differences in genotoxic potencies are less pronounced in the living animal.(ABSTRACT TRUNCATED AT 250 WORDS)

Dtsch Tierarztl Wochenschr, 1992 Jul, 99(7), 290 - 2
{Changes in the dynamics of viral infectious diseases}; Moennig V; Modern methods of molecular biology are suitable to analyse evolutionary processes in the area of infectious diseases . Visible expression of this evolution is the emergence of "new" infectious agents, e.g., canine parvovirus, the agent of the porcine reproductive and respiratory syndrome and phocine distemper virus . In addition a gradual change of disease syndromes may be observed, e.g., classical and African swine fever and myxoma . These processes are based on genomic changes of the respective infectious agents, i.e., point mutations and recombinations . Especially RNA viruses are prone to genomic change, and the plasticity of their genomes enables them to adapt to varying selective pressures . Human activities in agriculture, global commerce and tourism may enhance and precipitate microbial evolution.

Anal Biochem, 1992 Jul, 204(1), 40 - 6
Quantitative fluorometric analysis of plant and microbial chitosanases; Osswald WF et al.; A quantitative fluorometric assay for chitosanase activity in bacterial and plant tissues was developed . The assay can be conducted with either finely milled preparations of chitosan in suspension or dissolved chitosan; activity is based on measurements of glucosamine (GlcN) or oligomers of GlcN . GlcN is detected fluorometrically after reaction with fluorescamine with detection in the nanomole range . Fluorescence measurements of chitosanase activity and radioassay of chitinase in commercial preparations of chitinase from Streptomyces griseus revealed that both activities were present . Specific activities for the S . griseus chitosanase using suspended and soluble chitosans were respectively 1.24 and 6.4 mumol GlcN.min-1.mg protein-1 . Specific activity of the S . griseus chitinase was 0.98 mumol GlcN.min-1.mg protein-1 . Sweet orange callus tissue was tested for chitosanase and chitinase activity . It was necessary to remove small amine-containing molecules from the callus preparations before chitosanase activity could be assayed . The specific activity for chitinase and chitosanase in desalted extracts of nonembryogenic Valencia sweet orange callus tissue was determined to be 18.6 and 89.4 nmol GlcN.min-1.mg protein-1, respectively.

Z Lebensm Unters Forsch, 1992 Jul, 195(1), 1 - 2
Application of a microbial sensor for determination of short-chain fatty acids in raw milk samples; Ukeda H et al.; A microbial sensor system, based on the use of immobilized Arthrobacter nicotiana and an oxygen electrode, was applied to determine free short-chain fatty acids in raw milk samples and the result was compared with gas chromatography (GC) and a titrimetric method . The sensor response was linearly related to the concentration of short-chain fatty acids obtained by GC (n = 10, r = 0.92) and to the total concentration of free fatty acids obtained by titrimetric measurement (n = 10, r = 0.78) . This result suggests that the present microbial sensor can selectively determine free short-chain fatty acids in raw milk samples and may be useful as a very fast detection method of rancidity in milk.

Med Biol Eng Comput, 1992 Jul, 30(4), CE2 - 7
Opportunities for the cellular approach in biomedical engineering; Vadgama P; This review is a commentary on recent, altered perspectives about biomedical engineering and its role in medicine . It is argued that, rather than being a peripheral specialty, medical engineering and engineering principles in general have a direct application to biochemical medicine and cell biology . A brief description is given of the cell as a compartmentalised reactor system, and the ways in which it is possible to replace lost or aberrant cell function . Specific topics are then covered to illustrate the general thesis . These are: polymers for cell mimicry, cell-surface interactions, biomolecule transport, cell transport phenomena, cell signalling, harnessing of cells for therapy and microbial interactions . These disparate subject areas have a common thread of interest for the biomedical engineer, and are presented here in a way which highlights key points of relevance for engineering . Though necessarily brief, the various descriptions in this review provide a film indication that a rigorous approach to the assessment, modelling and use of cells along sound engineering lines is vital for the future . It is concluded that, without this approach, our understanding of cell biology will remain semiquantitative and semiempirical.

Reg Immunol, 1992 Jul-Aug, 4(4), 209 - 15
Ontogeny of lymphocyte activating factors in conventional and germfree rats; Granholm T et al.; Immune regulatory cytokines have previously been demonstrated outside the immune system in, e.g., the skin, testis, and brain, and suggested to serve as barrier site defence mediators . We have recently demonstrated constitutive production of an interleukin-1 (IL-1)-like factor(s) in the proximal gastrointestinal tract, liver, and placenta of adult rats . In the present study we have investigated the developmental production of IL-1-like factors in these tissues in conventional rats and in rats raised under germfree conditions . Slight IL-1 bioactivity was detected at a gestational age of 18 days in the skin and esophagus, and on day 19 significant amounts were detected in the skin, tongue, esophagus, and stomach . The activity was maximal at gestational day 20-21, and stationary at all later time-points . The placenta and liver contained high amounts of IL-1 activity throughout fetal life . The brain showed a transient appearance of IL-1 bioactivity at a gestational age of 19-21 days, but no activity at later time-points . Germfree rats showed no significant difference in the ontogeny or amounts of IL-1 bioactivity compared to conventional rats . It can be concluded that the IL-1 bioactivity appears at a definite time point in all measured tissues in fetal life and that exposure to microbial antigens does not seem to influence its production . As the investigated tissues show a high proliferation rate, it is tempting to suggest that the detected IL-1 (-like factors) might have an alternate function in these tissues, e.g., to serve as growth factors.

Mikrobiologiia, 1992 Jul-Aug, 61(4), 652 - 9
{Directed autoselection of bacteria during turbidostat cultivation}; Evdokomov EV et al.; A method has been proposed for directed bacteria autoselection, based on their sensitivity to growth inhibitors during continuous unlimited cultivation . A smooth increase of a growth inhibitor concentration in the medium has been used in response to the appearance and autoselection of more resistant strains . The aim can be reached by continuous measurements of the specific microbial growth rate during the process and its keeping at the required level by the inhibitor additions . The experimental data are given showing application of the method for Escherichia coli and Pseudomonas sp . turbidostat cultivation with valine, low pH and formaldehyde as inhibitors.

Bioessays, 1992 Jul, 14(7), 495 - 500
Use of the HPRT gene and the HAT selection technique in DNA-mediated transformation of mammalian cells: first steps toward developing hybridoma techniques and gene therapy; Szybalski W; In 1956, I decided to apply my experience in microbial genetics to developing analogous systems for human cell lines, including the selection of mutants with either a loss or gain of a biochemical function . For instance, mutants resistant to azahypoxanthine showed a loss of the HPRT enzyme (hypoxanthine phosphoribosyl transferase), whereas gain of the same enzyme was accomplished by blocking de novo purine biosynthesis with aminopterin, while supplying hypoxanthine and thymine (HAT selection) . Using HAT selection, we: (i) genetically transformed HPRT- mutant cells to HPRT+ wild type by using DNA extracted from HPRT+ cells, and (ii) selected HPRT+ hybrid cells by fusing HPRT- D98/AH2 cells with skin cells . These approaches, which we dubbed in 1962 as a 'first step toward gene therapy', contributed to the later development of (i) cell fusion techniques, (ii) the development of monoclonal antibodies, (iii) routine transformation of mammalian cells with cloned genes, and (iv) methods for creating transgenic organisms.

Cornea, 1992 Jul, 11(4), 334 - 42
Age-related morphological changes in lid margin and meibomian gland anatomy; Hykin PG et al.; Meibomian gland dysfunction (MGD) is responsible for recurrent irritative symptoms . Attempts to characterize MGD have largely concentrated on microbial and lipid abnormalities in meibomian gland secretions . Few reports describe histological abnormalities in this disease, and fewer still morphological changes . This article follows a previous study that established a classification for MGD . This was based on morphological changes in the meibomian gland and lid margin . Using this classification, we studied the age-related changes in 80 subjects, between 5 and 87 years of age without ocular disease . The lid margin became thicker after childhood . Lid margin vascularity and cutaneous hyperkeratinization increased with age in both lids, whereas, telangiectasia increased with age in the lower lid and squamous blepharitis and posterior lid margin rounding were more common after 50 years of age in the upper lid . Multiple rows of meibomian gland orifices occurred more frequently in the upper than lower lid, and orifice narrowing and pouting increased with age . No age-related changes in the shape or form of the mucocutaneous function, gland ducts, or acini were found . Meibomian gland secretions were less easily expressed in the elderly . We have attempted to define a normal range of lid morphology in healthy children and adults that we believe to be important for the subsequent definition of lid disease, and in particular, posterior blepharitis.

Fundam Appl Toxicol, 1992 Jul, 19(1), 117 - 23
Acute respiratory effects of endotoxin-contaminated machining fluid aerosols in guinea pigs; Gordon T; Exposure to machining fluid aerosols in the automotive industry is associated with a variety of respiratory symptoms including cross-shift changes in pulmonary function, cough, asthma, and phlegm . Lubricating and cooling fluids used in machining operations are predominantly water and thus are susceptible to microbial growth . In the present study, the role of endotoxin in the acute pulmonary injury produced by machining fluid aerosols was examined in guinea pigs . Animals were exposed to nebulized water, unused machining fluid, or used machining fluid . At the end of a 3-hr exposure, specific airway conductance (SGaw) was not affected by exposure to the vehicle water, but was decreased in a dose-dependent manner by exposure to aerosols of the used machining fluid . SGaw decreased from preexposure baseline values by 0, 7, and 40% in animals exposed to 1, 10, and 100 mg/m3 used machining fluid, respectively . These exposure levels also produced acute lung injury as evidenced by changes in cellular and biochemical indices in lavage fluid . These adverse respiratory effects may have been due to microbial contamination of the used machining fluid as the aerosol exposures were associated with airborne endotoxin concentrations of 0.3, 1.9, and 5.3 micrograms/m3, respectively . Animals exposed to aerosols of the endotoxin-free unused machining fluid had no statistically significant adverse functional, cellular, or biochemical effects except for a fourfold increase in neutrophils at 100 mg/m3 . These results suggest that contamination of machining fluid during use or storage may lead to the adverse respiratory effects of aerosolized machining fluids.(ABSTRACT TRUNCATED AT 250 WORDS)

Biotechnol Prog, 1992 Jul-Aug, 8(4), 347 - 52
Production and purification of a recombinant elastomeric polypeptide, G-(VPGVG)19-VPGV, from Escherichia coli; McPherson DT et al.; An elastomeric polypeptide was produced, with the sequence G-(VPGVG)19-VPGV, as a fusion to glutathione S-transferase using the vector pGEX-3X . The fusion protein was expressed to high levels in Escherichia coli as indicated by SDS-PAGE analysis of induced cells . The fusion protein was affinity purified and cleaved with protease factor Xa, and the elastomeric polypeptide was recovered to a high degree of purity as indicated by SDS-PAGE followed by staining with CuCl2 . The physical characterizations of carbon-13 and proton nuclear magnetic resonance and of the temperature profile for turbidity formation for the inverse temperature transition of hydrophobic folding and assembly attest to the successful microbial synthesis of the polypentapeptide of elastin . The results of these studies provide the initial progress toward achieving a more economical and practical means of producing material for elastic protein-based polymer research and applications.

Baillieres Clin Haematol, 1992 Jul, 5(3), 703 - 21
Transforming growth factor beta and interleukin-1: a paradigm for opposing regulation of haemopoiesis; Ruscetti FW et al.; The polypeptide cytokines, IL-1 and TGF-beta affect nearly every tissue and cell type in the body . IL-1 is the prototype of the proinflammatory molecule while TGF-beta is essentially anti-inflammatory . IL-1 is part of the cascade of cytokines that are produced during microbial invasion or bodily injury and enhance a variety of host responses, particularly in the immunological and haemopoietic systems, while TGF-beta acts as an inhibitor of these responses . At several levels, IL-1 and TGF-beta act in opposition to one another . IL-1 stimulates the expression of many genes in lymphoid and marrow stromal cells that stimulate haemopoietic cell growth and differentiation, while TGF-beta inhibits these IL-1 mediated effects . Also, TGF-beta stimulates secretion of the IL-1Ra . In addition, IL-1 induces the cell surface expression of cytokine receptors on lymphoid and haemopoietic cells, while TGF-beta dramatically inhibits the cell surface expression of these receptors, including the IL-1 receptor . Finally, IL-1 augments lymphoid and haemopoietic cell growth and TGF-beta potently inhibits this proliferation . The interactions of these cytokines serve to illustrate that the net balance of stimulatory and inhibitory signals determines the fate of a given cell which may be responsible for regulating homeostatic cell growth (Figure 1) . Thus, the regulation of cytokine production and/or antagonism of their effects continues to be a therapeutic goal in the treatment of many diseases.

J Clin Periodontol, 1992 Jul, 19(6), 417 - 22
Subgingival temperature (III) . Relation to microbial counts; Haffajee AD et al.; The present investigation examined the relationship of selected bacterial species and subgingival temperature . 35 subjects were measured at 6 sites per tooth for clinical parameters and subgingival temperature . Measurements were repeated for 21 subjects at 2 month intervals providing a total of 66 subjects visits . At each visit, subgingival plaque samples were taken from the mesial aspect of each tooth and anaerobically dispersed, diluted and plated on non-selective media . After anaerobic incubation, colonies were lifted to nylon filters and specific species detected using digoxigenin-labeled whole chromosomal DNA probes . Species enumerated were; A . actinomycetemcomitans serotypes a and b, B . forsythus, B . gingivalis, B . intermedius I and II, C . ochracea, F . nucleatum ss . vincentii, P . micros, S . intermedius, S . sanguis I and II, V . parvula and W . recta . Total viable counts and counts of Capnocytophaga sp . were determined directly from the primary isolation plates . A total of 1581 samples were evaluated . Subject visits with higher mean subgingival temperatures had significantly higher mean %s of B . intermedius I and P . micros, and lower mean %s of Capnocytophaga sp . Sites with higher subgingival temperatures had elevated proportions of B . intermedius I and II, A . actinomycetemcomitans serotype a and B . gingivalis more frequently than sites with lower temperatures, while Capnocytophaga sp . were elevated more often at cooler sites . 43 of the subject visits had follow up attachment level measurements at 2 months . The 1026 microbial samples and the subgingival temperature measurements from these visits were related to longitudinal attachment change.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochim Biophys Acta, 1992 Jun 29, 1135(3), 301 - 8
Effect of staurosporine on fMet-Leu-Phe-stimulated human neutrophils: dissociated release of inositol 1,4,5-trisphosphate, diacylglycerol and intracellular calcium; Nigam S et al.; Staurosporine, a microbial alkaloid, enhances inositol 1,4,5-trisphosphate (IP3) and 1,2-diacylglycerol (DG) production rapidly and dose-dependently in fMet-Leu-Phe (FMLP)-stimulated human neutrophils showing maximal effects at 1 microM concentration . The IP3 increase was specific for staurosporine as three other putative protein kinase C (PKC) inhibitors, H7, sphingosine and palmitoylcarnitine were unable to enhance the IP3 generation in FMLP-stimulated human neutrophils . Staurosporine, at concentrations 0.3-1.0 microM, did not affect the initial mobilization of FMLP-induced intracellular Ca2+ (Ca2+i), although a sustained elevation of cytosolic Ca2+ level was observed within 5 min . This effect could not be suppressed, even by 1 microM phorbol-myristate 12,13-acetate (PMA) . Whereas lower concentrations of staurosporine (less than or equal to 100 nM) were unable to affect FMLP-induced IP3 production, DG accumulation and Ca2+i, the PMA-inhibited initial Ca2+i signal and IP3 formation triggered by FMLP were almost completely restored . At higher concentrations (greater than or equal to 300 nM) staurosporine reversed the inhibitory effect of other protein kinases, distinct from the PMA-inducible one, which may be responsible for the phosphatidyl inositol 4,5-bisphosphate (PIP2) breakdown, thus causing accumulation of IP3 and DG and an elevation of C2+i level . Whereas IP3 declined to basal level within 5 min, the DG level remained elevated during the same period . This phenomenon is attributed to phospholipase D (PLD) stimulation by staurosporine, which augments the DG synthesis, in part through PA degradation via phosphatidic acid (PA) phosphohydrolase.

Sci Total Environ, 1992 Jun 18, 120(3), 205 - 12
Bioaccumulation of 137Cs and 60Co by a tropical marine teleost Epinephelus sp; Guimaraes JR; As part of a project on the behaviour of radionuclides released by the Angra Nuclear Power Station in the marine environment, laboratory experiments were performed to study cesium and cobalt accumulation by juvenile groupers (Epinephelus sp.) . The fishes were kept in aquariums equipped with gravel-bed filters spiked with 60Co (150 KBq/l) and 137Cs (75 KBq/l) . Uptake was only via water since the fishes received only non-radioactive food during the 4 months of experiment . Cesium accumulation in muscle was higher than in any other organ, reaching concentration factors (CFs) of 5 (fresh weight basis) . Cobalt, in contrast, was concentrated mostly in the liver, gut and skin and scales . Cobalt CF in muscle tissue was 8 x 10(-2), lower than any previously reported figure . Chromatographic analysis of the water at the beginning and end of the experiment showed that cobalt had been completely converted from 60CoCl2 to non-cationic forms, most probably through complexation with organic ligands, mediated by the intense microbial activity of the filter bed . This conversion apparently enhanced cobalt bioavailability since a second experiment performed with this aged seawater yielded CFs for muscle tissue higher by a factor of 2.5.

Gene, 1992 Jun 15, 115(1-2), 159 - 65
Secondary metabolites as chemical signals for cellular differentiation; Beppu T; Several microbial secondary metabolites function as essential chemical signals for induction of cellular differentiation in the producing organisms . The role of A-factor and its analogues such as essential autoregulators in actinomycetes is discussed and a review is given of fungal metabolites with hormonal activities . Divergent secondary metabolites with the capability to induce cellular differentiation in other organisms are also discussed as to their possible involvement in a symbiotic relationship in the ecosystem.

Gene, 1992 Jun 15, 115(1-2), 141 - 9
The expanded horizon for microbial metabolites--a review; Omura S; Modern screening methods have been used for a variety of new natural products . By taking advantage of the side effects of erythromycin, a derivative, EM523, and several related substances (motilides) have been synthesized . These compounds are agonists of the peptide hormone, motilin . By screening for microbial metabolites which may substitute for biologically active peptides, we discovered lactacystin . It has nerve growth-factor-like activity and induces differentiation in mouse neuroblastoma Neuro2A cells . An inhibitor of protein kinase, staurosporine, a microbial alkaloid found by chemical screening, has a variety of pharmacological activities, such as the relaxation of rabbit aortic strips and the inhibition of changes in platelet shape induced with phorbol myristate acetate . Triacsin, an inhibitor of acetyl-CoA synthetase, which was isolated from Streptomyces sp . SK-1894, potentiated platelet-activating factor production of A23187-treated rat polymorphonuclear leukocytes . Phthoxazolin, an inhibitor of cellulose biosynthesis isolated from Streptomyces sp . OM-5714, inhibited the growth of velvet leaf when treated after its emergence . These products provide examples of the possible utility of newly discovered microbial metabolites.

Transfus Sci, 1992 Jul, 13(3), 353 - 6
Effective concentration of bone marrow mononuclear cells using density gradient separation within an automated cell separator; Baker PK et al.; An effective method for concentrating bone marrow is described . Concentration was achieved using an intermittent flow cell separator . Elimination of mature haemopoietic cells was enhanced by the addition of a density separation medium (Ficoll-metrizoate) which was then removed by washing . All procedures were undertaken using the cell separator, this allowed for standardization of procedure and less manipulation which is associated with enhanced mononuclear cell recovery and less risk of microbial contamination . Mature granulocytes were depleted by 86.8% and red cells by 97.7% whilst mononuclear cells showed a 49% recovery . Marrows processed in this way and subsequently purged and/or cyropreserved were shown to successfully engraft when reinfused.

Biochim Biophys Acta, 1992 Jun 5, 1126(1), 41 - 8
Inhibition of the accumulation of lipid droplets in macrophage J774 by bafilomycin B1 and destruxin E; Naganuma S et al.; Two microbial metabolites, bafilomycin B1 and destruxin E, have been found to inhibit significantly the oxidized low density lipoprotein (LDL)-induced accumulation of lipid droplets at 3 nM and 0.5 microM, respectively, in macrophage J774 . The incorporation of {14C}oleate into cholesteryl esters in the cells incubated with oxidized LDL was inhibited to the same extent by the two compounds . Both compounds had no effect on the cell surface binding at 4 degrees C and the internalization of oxidized 125I-LDL as well as on the activity of acyl-CoA:cholesterol acyltransferase . However, when incubated with these compounds at 37 degrees C, receptors for oxidized LDL were partially trapped within the cell . In accordance with receptor accumulation, ATP-dependent acidification of endosomes and lysosomes was significantly inhibited by 50 nM bafilomycin B1 and 1 microM destruxin E, respectively . From these results it was concluded that the inhibition of ATP-dependent acidification of endosomes and lysosomes by bafilomycin B1 and destruxin E resulted in the reduction of oxidized LDL-induced synthesis of cholesteryl ester and thereby caused a reduced accumulation of lipid droplets in macrophage J774.

J Anim Sci, 1992 Jun, 70(6), 1957 - 64
Effects of ruminally degradable and escape protein supplements on steers grazing summer native range; Karges KK et al.; One experiment was conducted during 1989 to determine whether a deficiency exists for either ruminally degradable or escape protein in steers grazing summer native range . Increasing levels of ruminally degradable (.15, .27, and .37 kg/d) and escape protein (.07, .14, and .21 kg/d) replaced a cornstarch and molasses (energy control) supplement . Supplements were isoenergetic and fed individually to steers (.88 kg/d) . No response to the degradable protein supplement (P = .15) was observed; however, a linear gain response (P less than .01) was observed in steers fed escape protein in addition to ruminally degradable protein . An in vitro study indicated that more (P less than .01) microbial protein was synthesized from the energy supplement than from the degradable protein; this finding presumably relates to the numerical decrease in weight gains observed for steers fed degradable protein supplements . Analyses of esophageal extrusa samples indicated that CP was relatively constant for the 1989 growing season compared with the 1988 growing season (P less than .05) . Escape protein values differed (P less than .01) between years and among months within year . Forages that were apparently grazed in 1989 were never deficient in degradable protein . Additional gain observed from feeding escape protein would indicate that microbial protein synthesis may be insufficient to satisfy the metabolizable protein requirement, which probably limited gains by steers grazing summer native range.

Gut, 1992 Jun, 33(6), 801 - 6
Mucosal immune defence mechanisms in enterocolitis complicating Hirschsprung's disease; Imamura A et al.; Enterocolitis remains an important cause of morbidity and mortality in Hirschsprung's disease . The aetiology of enterocolitis is uncertain-ischaemic and bacterial causes and recently, rotavirus infections, have been suggested . Bowel tissue from 12 patients with Hirschsprung's disease who underwent Swenson's operation (five of whom had clinical evidence of enterocolitis) and colon from six controls subjects were examined to investigate possible immunopathological mechanisms associated with the disease . IgA, IgM, and J chain (but not IgG) containing plasma cells were significantly increased in the lamina propria along the entire length of resected bowel in enterocolitis patients, compared with non-enterocolitis patients and controls (p less than 0.01) . Luminal secretory component staining of the anganglionic segment of colon from enterocolitis patients was considerably reduced . Lamina propria CD68 positive monocyte/macrophages and CD45RO positive leukocytes were increased in enterocolitis patients compared with non-enterocolitis patients (p less than 0.01) . CD57 positive natural killer (NK) cells showed a unique distribution pattern compared with other cell types . Patients with enterocolitis showed a significant increase in CD57 positive NK cells in the lamina propria of ganglionic bowel only (p less than 0.05) . NK cell values in ganglionic bowel of non-enterocolitis patients and in aganglionic bowel in all patients were similar to controls . The diversity of altered local immune response seen in this study may reflect a multifactorial microbial aetiology in enterocolitis associated with Hirschsprung's disease.

J Am Diet Assoc, 1992 Jun, 92(6), 719 - 23
Irradiated or aseptically prepared frozen dairy desserts: acceptability to bone marrow transplant recipients; Dong FM et al.; Sterile ice cream and frozen yogurt were offered to immunosuppressed patients recovering from bone marrow transplantation . To obtain sterile products, two of the dairy desserts (prepackaged ice cream and frozen yogurt bars) were exposed to 40 kGy of cobalt 60 irradiation . Four different flavors of ice cream were aseptically prepared under a laminar airflow hood using commercially sterilized ingredients . A commercially sterile, frozen milk-based drink on the low-microbial menu served as the control . Ratings of the seven products by 17 patients indicated that a frozen vanilla milk-based drink and aseptically prepared chocolate ice cream were highly acceptable to recovery immunosuppressed patients who have difficulty eating most foods . However, the seven desserts received higher ratings from a sensory panel of healthy individuals than from the patient panel, confirming that new foods for the low-microbial diet should be "market-tested" by the targeted patient population before inclusion in the menu.

Am J Hosp Pharm, 1992 Jun, 49(6), 1467 - 70
Stability of flecainide acetate in an extemporaneously compounded oral suspension; Wiest DB et al.; The stability of flecainide acetate in an oral diluent stored for 45 days under various conditions was studied . A suspension was prepared by triturating 100-mg tablets of flecainide acetate with a commercially available oral diluent . The final theoretical drug concentration was 5 mg/mL . The suspension was poured into 12 2-oz amber glass prescription bottles for a per-bottle volume of 60 mL . Three bottles were refrigerated at 5 degrees C and shaken before analysis, three were stored at room temperature and shaken, three were refrigerated and not shaken, and three were kept at room temperature and not shaken . On days 0, 15, 30, and 45, flecainide acetate concentrations were determined by stability-indicating high-performance liquid chromatography . The concentration of flecainide acetate in the sediment in each bottle was determined on day 46 . On day 45, the mean flecainide acetate concentration for each group of bottles remained above 90% of the initial concentration . Mean +/- S.D . flecainide acetate concentrations in sediment ranged from 0.53 +/- 0.30 to 1.18 +/- 0.36 mg per gram . Eight of the 12 samples contained microbial growth on at least one of the test days . Flecainide acetate 5 mg/mL oral suspension was stable for up to 45 days under the conditions investigated.

J Trop Pediatr, 1992 Jun, 38(3), 132 - 6
Host factors and acute lower respiratory infections in pre-school children; Johnson WB et al.; The relationship between certain host-related variables and the short-term outcome of hospitalization for severe acute lower respiratory infections was studied prospectively in a cohort of 103 pre-school Nigerian children . The respective mean ages of those with bronchiolitis and croup were 3.2 months and 18.9 months while the corresponding M:F ratios were 2.5:1 and 1:1 . It was highly significant that all the eight children that died were malnourished (P less than 0.01) . Furthermore, malnourished subjects with pleural effusion, in whom bacteraemia was common, stayed longest in hospital while subjects with bronchiolitis and croup, in whom malnutrition was distinctly uncommon, had the shortest duration of admission . Multiple microbial identifications and bacteraemia were common in malnourished subjects with ALRI . Mortality was significantly higher in older children (P less than 0.05), but sex, immunization/breast-feeding status and co-existing measles or pertussis, were individually neither related to the admission outcome nor the duration . It is concluded that malnutrition is a strong predictor of ALRI-related death in the pre-school child . The significance of bacteraemia and multiple microbial identifications in malnourished children, and the ARI-control implications of the study are discussed.

Plant Cell, 1992 Jun, 4(6), 721 - 33
Two anthranilate synthase genes in Arabidopsis: defense-related regulation of the tryptophan pathway; Niyogi KK et al.; Arabidopsis thaliana has two genes, ASA1 and ASA2, encoding the alpha subunit of anthranilate synthase, the enzyme catalyzing the first reaction in the tryptophan biosynthetic pathway . As a branchpoint enzyme in aromatic amino acid biosynthesis, anthranilate synthase has an important regulatory role . The sequences of the plant genes are homologous to their microbial counterparts . Both predicted proteins have putative chloroplast transit peptides at their amino termini and conserved amino acids involved in feedback inhibition by tryptophan . ASA1 and ASA2 cDNAs complement anthranilate synthase alpha subunit mutations in the yeast Saccharomyces cerevisiae and in Escherichia coli, confirming that both genes encode functional anthranilate synthase proteins . The distributions of ASA1 and ASA2 mRNAs in various parts of Arabidopsis plants are overlapping but nonidentical, and ASA1 mRNA is approximately 10 times more abundant in whole plants . Whereas ASA2 is expressed at a constitutive basal level, ASA1 is induced by wounding and bacterial pathogen infiltration, suggesting a novel role for ASA1 in the production of tryptophan pathway metabolites as part of an Arabidopsis defense response . Regulation of key steps in aromatic amino acid biosynthesis in Arabidopsis appears to involve differential expression of duplicated genes.

Anticancer Drugs, 1992 Jun, 3(3), 293 - 9
Effect of 15-deoxyspergualin, a microbial angiogenesis inhibitor, on the biological activities of bovine vascular endothelial cells; Oikawa T et al.; We found recently that 15-deoxyspergualin, an analog of spergualin, which is an antibiotic and includes a spermidine moiety in its structure, exhibits anti-angiogenic activity . We have now carried out in vitro experiments with bovine vascular endothelial cells to determine which events occurring during angiogenesis are affected by this microbial angiogenesis inhibitor . 15-Deoxyspergualin did not inhibit the production of urokinase-type plasminogen activator (u-PA) or type IV collagenase by vascular endothelial cells . The direct inhibition of u-PA activity by 15-deoxyspergualin was not observed either . The angiostatic antibiotic neither affected the migration of vascular endothelial cells nor inhibited the endothelial cell proliferation in a two-dimensional culture system . We also examined the effect of 15-deoxyspergualin on the proliferation of endothelial cells in a three-dimensional culture system involving collagen gel, in which cell growth resembles more closely the endothelial cell proliferation during in vivo angiogenesis than that in a two-dimensional culture system without collagen gel . The antibiotic inhibited cell proliferation in a dose-dependent manner, indicating that the three-dimensional culture system is useful for finding a new angiogenesis inhibitor with a different mode of action from those of angiogenesis inhibitors found by using a two-dimensional assay system; however, no cause-effect relationship has yet been established . Taken together, these results suggest the possible involvement of the inhibition of vascular endothelial cell growth by 15-deoxyspergualin in its angiogenesis-inhibitory effect . 15-Deoxyspergualin appears to be a promising candidate as an angiogenesis inhibitor for controlling aberrant angiogenic responses occurring in different states, including tumor development.(ABSTRACT TRUNCATED AT 250 WORDS)

Plant Mol Biol, 1992 Jun, 19(3), 391 - 9
The isolation and characterisation of a cDNA clone encoding L-asparaginase from developing seeds of lupin (Lupinus arboreus); Lough TJ et al.; An L-asparaginase cDNA clone, BR4, was isolated from a Lupinus arboreus Sims developing seed expression library by screening with polyclonal antibodies to the seed asparaginase . The cDNA hybridised with an oligonucleotide probe designed from amino acid sequence data and was found on sequencing to be 947 bp in length . Six polypeptide sequences obtained previously could be placed along the longest open reading frame . Computer-aided codon use analysis revealed that the cDNA sequence was consistent with other plant genes in terms of codon use . The cDNA insert was used to analyse asparaginase transcription in various tissues by northern blot analysis . A transcript size of approximately 1.2 kb was detected in L . arboreus seed total and poly(A)+ RNA . The level of this transcript declined from 30 days after anthesis to an undetectable level by day 55 . Furthermore, under the high stringency conditions used, the seed asparaginase cDNA did not hybridise with total or poly(A)+ RNA isolated from root tips, suggesting that the asparaginase known to be present in this tissue may be the product of a different gene . Southern analysis suggested the seed asparaginase is a single-copy gene . The plant asparaginase amino acid sequence did not have any significant homology with microbial asparaginases but was 23% identical and 66% similar (allowing for conservative substitutions) to a human glycosylasparaginase.

J Biotechnol, 1992 Jun, 24(1), 33 - 51
The way to adequate control of microbial processes passes via real-time knowledge-based supervision; Konstantinov KB et al.; Knowledge-based supervision is viewed as a major tool for achieving high-performance control of microbial processes . By providing an adequate insight into the integral state of the cell culture, knowledge-based supervisory systems allow for monitoring and handling various important phenomena which usually remain outside the scope of the conventional control approach . The present paper focuses on the development of a computer system for knowledge-based supervision of bioprocesses . Its application to the control of fed-batch cultivation of recombinant Escherichia coli for phenylalanine production is also discussed.

J Anim Sci, 1992 Jun, 70(6), 1941 - 9
Site and extent of nutrient digestion by steers fed a low-quality bromegrass hay diet with incremental levels of soybean hull substitution; Grigsby KN et al.; Five ruminally and duodenally cannulated steers were fed bromegrass hay (H; 5.6% CP; 70.9% cell wall) substituted with 0, 15, 30, 45, or 60% soybean hulls (SH; 10.5% CP; 87.9% cell wall) at 90% of ad libitum DMI . Diets were made isonitrogenous (11% CP) by addition of isolated soybean protein (91.5% CP) . Total ruminal VFA concentration, molar proportion of acetate, and molar acetate:propionate ratio increased (linear; P less than .02) with increasing level of SH substitution, but propionate (mol/100 mol) and ruminal fluid passage rate decreased (linear; P less than .01) . Ruminal pH and ammonia concentration decreased more rapidly, and to a greater extent and duration, as level of SH increased; neither was decreased to levels considered detrimental to fiber digestion . Ruminal and total tract DM, OM, and cell wall digestibilities increased (linear; P less than .01), whereas total tract N digestibility decreased (linear; P = .03), as level of SH increased Total N flow to the duodenum increased (linear, P = .03) with increasing level of SH, and microbial N flow tended (cubic, P = .09) to increase . Microbial efficiencies were unchanged (P = .10) with SH level . True ruminal digestibilities of N did not differ (P greater than .10) among diets . Rate of in situ DM disappearance of H and SH was not influenced (P greater than .10) by SH substitution, although rate tended to be fastest with 30 and 45% SH (quadratic, P = .14) . We infer from these data that SH can replace 60% of the DMI of a low-quality forage diet without decreasing OM or cell wall digestion.

Lab Anim Sci, 1992 Jun, 42(3), 307 - 11
Evaluation of a subcutaneously implanted chamber for antibody production in rabbits; Clemons DJ et al.; Polyclonal antibody production in subcutaneous chambers was compared to traditional antibody production methods in rabbits . The chamber, a sterilized plastic wiffle golf ball that had been surgically implanted in the subcutis of the thoracic region, was immunized via a percutaneous injection of antigen into the core of the ball through one of the perforations in the chamber wall . Rabbits bearing chambers were immunized on the same schedule and with the same concentrations of antigens as were provided the adjuvant injected rabbits . Fluid volumes of 12 to 22 ml could be removed from each chamber at weekly intervals . Chamber antibody to specific microbial antigens was equal to or better than serum antibody produced to the same antigens with Freund's or acrylamide adjuvants . The comfort of the rabbit, the ease in chamber immunization, and the recovery of high titer antibody in large volumes make the subcutaneous chamber an attractive method for polyclonal antibody production.

Fogorv Sz, 1992 Jun, 85(6), 163 - 70
{Chemical plaque control}; Keszthelyi G; Most of the diseases with which dentists must deal with are related to microbial plaque and bacterial infection . The mechanical removal of supra- and subgingival plaque by the patient and by the dentist respectively, is time consuming and exacting, furthermore it is not one hundred per cent successful . There has been extensive search for many years for chemical agents that could supplement or even substitute mechanical plaque removal . Many chemical agents delivered in different ways were tested . Chemotherapeutics of various modes of action have to meet pharmacokinetic and biological requirements . Apparently the ideal anti-plaque agent is not yet available, so that they should be reserved for well defined clinical situations and short--or medium--term application.

Endod Dent Traumatol, 1992 Jun, 8(3), 93 - 8
Oral defense factors in the elderly; Tenovuo J; Continuously increasing proportion of elderly people in the human population creates new challenges for the dental care . Because the microbial etiology of the most common oral diseases, dental caries, endodontal and periodontal diseases, is not substantially different in different age groups, the altered host response during aging may modify the progression of these diseases . Most prevalent and severe change in the oral defense is hyposalivation or xerostomia but aging as such does not seem to reduce neither parotid nor whole salivary flow rate . However, submandibular and minor salivary glands produce less saliva at old age which may be the reason for the frequently reported symptoms of oral dryness even if the stimulated flow rate is normal . Concomitantly to the changes in the flow rate the daily output of many saliva-mediated defense factors declines but age-related impairment has been described only for specific IgA response to external antigens, for salivary opsonic activity, and for T-lymphocyte function . The non-immunoglobulin defense factors seem to act with full capacity over the entire life-span . Therefore, elderly people with normal salivary flow rate possess no special risk group for the development of oral diseases.

Infect Agents Dis, 1992 Jun, 1(3), 121 - 35
Immunity, microbial pathogenesis, and immunophilins: finding the keys, now where are the locks?
High KP, Handschumacher RE.
The discovery and clinical use of the immunosuppressants cyclosporin A, FK506, and rapamycin have greatly advanced solid organ and bone marrow transplantation . Though active as antibiotics against a variety of pathogens, their utility has been severely limited by toxicity . Research on the immunophilins, the major binding proteins of these drugs, has given new insights into protein folding and transport as well as mediators of signal transduction in mammalian cells . Microbial immunophilins may also have direct relevance to the intracellular survival of important human pathogens . Defining the mechanisms of enhanced virulence generated by these proteins holds great promise for understanding both the fundamental pathogenesis of these organisms and the immune response generated against them . Such an understanding may provide novel targets for the design of anti-infective agents as well as assist in the development of future immunosuppressives.

Cell, 1992 May 29, 69(5), 861 - 9
Mechanism of C . trachomatis attachment to eukaryotic host cells; Zhang JP et al.; A novel trimolecular mechanism of microbial attachment to mammalian host cells was characterized for the obligate intracellular pathogen Chlamydia trachomatis . Using purified glycosaminoglycans (GAGs) and specific GAG lyases, we demonstrated that a heparan sulfate-like GAG present on the surface of chlamydia organisms is required for attachment to host cells . These observations were supported by inhibition of attachment following binding of heparan sulfate receptor analogs to chlamydiae and by demonstrating that chlamydiae synthesize a unique heparan sulfate-like GAG . Furthermore, exogenous heparan sulfate, as an adhesin analog, restored attachment and infectivity to organisms that had lost these attributes following treatment with heparan sulfate lyase . These data suggest that a GAG adhesin ligand mediates attachment by bridging mutual GAG receptors on the host cell surface and on the chlamydial outer membrane surface.

Med J Aust, 1992 May 18, 156(10), 683 - 7
Chronic colitis associated with human immunodeficiency virus infection; Hing MC et al.; OBJECTIVE: A clinical and pathological description of chronic colitis associated with human immunodeficiency virus (HIV) infection . DESIGN: A retrospective case review . SETTING: Tertiary referral institution and specialist gastroenterology practice . PATIENTS: A series of six patients with human immunodeficiency virus infection and chronic colitis observed for up to four years . RESULTS: The six patients had chronic diarrhoea for longer than six months, rectal bleeding, abdominal pain and stool leukocytosis . The mucosal pattern on colonoscopy showed diffuse proctocolitis, consisting of contact bleeding, superficial ulcerations, exudates, and/or loss of vascular pattern . Colonic biopsies showed a persisting diffuse colitis characterised principally by a mixed inflammatory cell infiltrate (mononuclear cells and neutrophils) and essentially preserved crypt architecture after six to 39 months of histological follow-up . The histopathology over this time frame was not typical of ulcerative colitis or Crohn's disease, nor of the conventionally described forms of infective colitis . HIV nucleic acid was identified by insitu hybridisation in colonic biopsies from four patients . In two of three patients tested, the presence of HIV DNA was confirmed by Southern blot analysis . No other microbial agent could be demonstrated as the cause of diarrhoea . At presentation all patients had CD4+ lymphocyte counts greater than 265 x 10(6)/L and none had the acquired immunodeficiency syndrome . Four patients have gone into remission, the other two patients were not in remission at four and a half to five years after onset . CONCLUSION: We suggest that chronic colitis may represent a new entity related to infection of the colon with human immunodeficiency virus.

Ann Intern Med, 1992 May 15, 116(10), 821 - 8
Clinical and metabolic efficacy of glutamine-supplemented parenteral nutrition after bone marrow transplantation . A randomized, double-blind, controlled study; Ziegler TR et al.; OBJECTIVE: To determine whether glutamine-supplemented parenteral nutrition improves nitrogen retention and reduces hospital morbidity compared with standard parenteral nutrition after bone marrow transplantation . DESIGN: Double-blind, randomized, controlled clinical trial . SETTING: University teaching hospital . PATIENTS: Forty-five adults receiving allogeneic bone marrow transplants for hematologic malignancies . INTERVENTION: Parenteral nutrition was initiated the day after bone marrow transplantation (day 1) . The experimental solution was supplemented with L-glutamine (0.57 g/kg body weight per day) and provided estimated requirements for energy and protein . The control solution was a standard, glutamine-free, isonitrogenous, isocaloric formula . MEASUREMENTS: Nitrogen balance was determined between days 4 and 11 in the initial 23 patients . The incidence of clinical infection and microbial colonization, time until bone marrow engraftment, indices of clinical care, and other data related to hospital morbidity were recorded for all patients . RESULTS: The glutamine-supplemented patients (n = 24) were clinically similar to the controls (n = 21) at entry . Nutrient intake was similar in both groups; however, nitrogen balance was improved in the glutamine-supplemented patients relative to the controls (-1.4 +/- 0.5 g/d compared with -4.2 +/- 1.2; P = 0.002) . Fewer experimental patients developed clinical infection (three compared with nine in the control group; P = 0.041), and the incidence of microbial colonization was also significantly reduced . Hospital stay was shortened in patients receiving glutamine supplementation (29 +/- 1 d compared with 36 +/- 2 d; P = 0.017) . CONCLUSION: Patients receiving glutamine-supplemented parenteral nutrition after bone marrow transplantation had improved nitrogen balance, a diminished incidence of clinical infection, lower rates of microbial colonization, and shortened hospital stay compared with patients receiving standard parenteral nutrition . These effects occurred despite no differences between groups in the incidence of fever, antibiotic requirements, or time to neutrophil engraftment.

J Immunol, 1992 May 15, 148(10), 3264 - 70
Infection with Schistosoma mansoni alters Th1/Th2 cytokine responses to a non-parasite antigen; Kullberg MC et al.; Schistosoma mansoni infection in the mouse has been shown to be accompanied by a down-regulation in parasite-Ag- and mitogen-induced Th1 cytokine secretion (IL-2 and IFN-gamma) with a simultaneous increase in the production of Th2 cytokines (IL-4, IL-5, and IL-10), suggesting a generalized imbalance in lymphocyte function . In the present study, we examined whether infection with S . mansoni would also influence the character of immune responses to a non-parasite Ag, sperm whale myoglobin (SwMb) . When spleen cells (SC) from schistosome-infected SwMb-immunized animals were stimulated with SwMb, their production of IL-2 and IFN-gamma per CD4+ cell was found to be significantly reduced (by 45% and 59%, respectively) compared with the responses observed in immunized uninfected animals . Moreover, SwMb-induced secretion of IL-4 per CD4+ cell was increased threefold in SC cultures from infected mice . No myoglobin-induced IL-5 was detected in the same cultures . Addition to SC cultures of a neutralizing mAb specific for IL-10 partly restored the suppressed IFN-gamma response to SwMb seen in infected mice, suggesting a role for IL-10 in the observed down-regulation . S . mansoni-infected mice also showed an impaired antibody response to SwMb, with levels ranging from 10% to 27% of those observed in uninfected mice, although no differences in IgG isotype were evident . Taken together, these results suggest that infection with S . mansoni induces a down-regulation of Th1 responses and elevation of Th2 responses to unrelated foreign immunogens as well as to parasite Ag themselves . One implication of these findings is that helminth-infected individuals may have altered cell-mediated immune function to other microbial agents.

Surg Gynecol Obstet, 1992 May, 174(5), 435 - 40
The role of the complement system in trauma and infection; Gallinaro R et al.; The complement system is an important immediate host defense mechanism after trauma, extensive burn injury and after invasion by microbial pathogens . Massive complement activation, however, seems to be detrimental and may contribute further to the disease process and eventually to multiple organ failure or the septic state . In clinical situations in which complement is damaging, the logical therapy should be, if at all possible, the removal of the activated complement components from the circulation . However, much of the protein is attached to the membrane and effective locally, so prevention of the enzymatic cascade may be more appropriate . There has been little progress in manipulating the complement system to effectively alter such disease processes caused by the clinical situations and there is an important need for further research in the field.

Immunology, 1992 May, 76(1), 129 - 32
Influence of H-2 genes on growth of Mycobacterium tuberculosis in the lungs of chronically infected mice; Brett S et al.; Mice infected by intraperitoneal injection of Mycobacterium tuberculosis were studied over a 23-week period . They showed progressive infection in the lung (with increasing microbial count and granuloma size) whereas viable bacillary counts remained largely stationary in the spleen and in the liver . The influence of H-2 genes on the progression of the lung infection was studied in four congenic strains of animals with B10 and three congenic strains of animals with BALB backgrounds . H-2k mice had significantly higher bacterial counts in the lung than H-2b mice on both B10 and BALB backgrounds, BALB . K (H-2k) mice were also more susceptible than BALB/c (H-2d) mice . Results with recombinant strains showed that bacillary counts and granulomatous infiltration were lower in the B10 (KbAbE-Db) compared with B10.A(3R) (KbAbEbDd) strain and in B10.A(4R) (KkAkE-Db) compared with B10.BR (KkAkEkDk) mice . This resistance to the late expansion of tuberculous infection in the lungs may be associated with the lack of an expressed I-E molecular or with the expression of the Db molecule.

FEMS Microbiol Lett, 1992 May 1, 71(3), 229 - 33
Biosynthesis of glyantrypine by Aspergillus clavatus; Penn J et al.; The biosynthesis of glyantrypine from radiolabelled amino acid precursors has been shown experimentally to involve anthranilic acid, tryptophan and glycine . Low values for percentage incorporation of radiolabel into glyantrypine were partly influenced by a complex array of other novel alkaloids shown by the radiolabelling experiments to be related to glyantrypine . Interpretation of radiolabel incorporation from {14C-carboxyl}-anthranilic acid into microbial metabolites seen to contain an anthranilyl moiety in various biosynthetic arrangements is discussed . The possibility of diversion of anthranilic acid from the kynurenine pathway to glyantrypine biosynthesis is recognised.

Appl Environ Microbiol, 1992 May, 58(5), 1719 - 26
Chlorobenzene degradation by bacteria isolated from contaminated groundwater; Nishino SF et al.; Bacterial isolates were obtained from groundwater and soils contaminated with chlorobenzene (CB) . The isolates were tested to determine whether the natural community could remove the groundwater contaminants . These isolates were identified and characterized as to their ability to grow on CB and related aromatic compounds . The complete consortium could mineralize approximately 54% of the CB within 7 days, with no accumulation of 3-chlorocatechol . Metabolic pathways were evaluated for several isolates . One phenotype was characterized by the ability to degrade CB by the modified ortho pathway . One strain also degraded p-dichlorobenzene by using the same pathway . Isolates exhibiting a second phenotype degraded p-cresol, benzene, and phenol by the classical ortho pathway and accumulated 3-chlorocatechol when grown in the presence of CB . Strains of the third phenotype grew on complex media in the presence of CB but did not transform any of the aromatic compounds tested . The results suggest that the indigenous microbial community at the contaminated site would be able to degrade CB if provided with the appropriate conditions.

Appl Environ Microbiol, 1992 May, 58(5), 1554 - 63
Mineralization of glucose and lignocellulose by four arctic freshwater sediments in response to nutrient enrichment; McKinley VL et al.; Microbial biomass and activity were examined in four different arctic sediments: littoral lake sediment and profundal lake sediment from Toolik Lake, Alaska, thaw pond sediment, and eroding river bank peat . The thaw pond sediment had the largest viable microbial biomass, while the profundal sediment had the smallest . Rates of glucose or acetate incorporation into lipids, glucose mineralization, and lignocellulose mineralization (all normalized per unit of biomass) were highest in the river peat sample, however . The kinetics of glucose mineralization in the profundal sediment were very different from those in the other three samples: although the initial rate of mineralization was five times lower than that in the peat and two times lower than that in the littoral and thaw pond sediments, the maximum amount of 14CO2 evolved from {14C}glucose eventually equaled that in the peat and exceeded that in the littoral and thaw pond sediments by 2.0 and 3.5 times, respectively . Carex aquatilis {14C-cellulose}- and {14C-lignin}lignocellulose mineralization rates in the profundal sediment equaled or exceeded those in the littoral sediment after 16 and 46 days, but the pattern of nutrient limitation differed: the profundal sediment was the only one sampled that exhibited nitrogen limitation, while the other three sediments appeared to be limited primarily by phosphorus . The addition of nitrogen and phosphorus together had no cumulative effects on lignocellulose mineralization . When the rates of mineralization or incorporation of glucose are compared with those of lignocellulose, the results of this study indicate that profundal sediment communities may be better able to utilize the more recalcitrant substrates relative to the labile substrates than microbial communities from sediments rich in detritus and standing macrophytes.

Respir Med, 1992 May, 86(3), 225 - 35
An investigation of the relationship between microbial and particulate indoor air pollution and the sick building syndrome; Harrison J et al.; The sick building syndrome has been the subject of research for approximately 10 years . Although it is often suggested that symptoms in office workers are due to circulating micro-organisms or particles, epidemiological studies investigating the relationship between them have been lacking . This cross-sectional study has combined medical and aerobiological assessments of offices in Great Britain and has found that, although airborne particulates and micro-organisms are unlikely to be the sole cause of the sick building syndrome, positive associations between symptom prevalence rates and levels of airborne viable bacteria and fungi within groups of buildings with similar ventilation systems, suggest a possible causal link that should be explored.

Pharm Res, 1992 May, 9(5), 623 - 5
Microbial production of a crisnatol metabolite; Hufford CD et al.; Microbial metabolism studies of crisnatol (1), a new DNA intercalator, has resulted in the isolation and characterization of a major metabolite identified as the C-1 hydroxylated crisnatol (2) . The structure of the metabolite was established by comparison of its spectral data to that of crisnatol . Complete 13C-NMR assignments for crisnatol and its C-1 hydroxylated metabolite were also made.

Anaesthesia, 1992 May, 47(5), 414 - 20
A comparison of the filtration properties of heat and moisture exchangers; Hedley RM et al.; Heat and Moisture Exchangers are used increasingly as filters to prevent the contamination of breathing apparatus and to limit cross-infection . A series of laboratory tests has been developed to evaluate the microbial filtration and air flow resistance properties of these devices . The tests were designed to simulate the clinical situation and therefore evaluated devices in both dry and wet conditions . The devices tested (Engstrom Edith, Pall BB50T, Dar Hygrobac, Intersurgical Filtatherm and Intersurgical Filtaguard) were each representative of a particular type of construction . The simple hygroscopic device (Engstrom Edith) showed poor airborne and liquid-borne filtration efficiency, but its resistance to air flow remained low in all conditions . The composite devices (Dar Hygrobac, Intersurgical Filtatherm and Intersurgical Filtaguard), which all possessed relatively large pores, performed well in terms of dry airborne filtration efficiency, but showed substantial increases in air flow resistance and poor filtration efficiency in the presence of liquid . The pleated membrane filter (Pall BB50T), which possessed small pores, showed good airborne filtration efficiency and prevented the passage of liquid . The latter property enabled this device to prevent the passage of liquid-borne contamination and to maintain a low resistance to air flow in wet conditions . It would appear that in terms of contamination control and air flow resistance the pleated membrane filter provides a wider margin of safety than either the hygroscopic or composite devices.

Am J Obstet Gynecol, 1992 May, 166(5), 1382 - 8
The relationship between acute inflammatory lesions of the preterm placenta and amniotic fluid microbiology; Romero R et al.; OBJECTIVE: Our objective was to determine the relationship between microbial invasion of the amniotic cavity and the presence and severity of acute inflammatory lesions in the placenta . STUDY DESIGN: Placental histologic and amniotic fluid microbiologic studies were performed in 92 consecutive patients who were admitted with preterm labor and intact membranes and delivered within 48 hours after amniocentesis . RESULTS: The prevalence of a positive amniotic fluid culture was 38% (35 of 92) . There was a strong association between the presence and severity of inflammation in the amnion, chorion-decidua, umbilical cord, and chorionic plate and the results of the amniotic fluid culture (p less than 0.0001 for each tissue section) . Three patterns of inflammation of the chorion-decidua were identified: marginating, nonmarginating, and a mixed pattern . The marginating and the mixed patterns of inflammation were strongly associated with the presence of a positive amniotic fluid culture . Acute inflammation of the chorionic plate was the most sensitive indicator of a microbial invasion of the amniotic cavity (sensitivity 96.6%), and funisitis and umbilical vasculitis had the highest specificity (85.7%) . CONCLUSION: The presence of acute inflammatory lesions of the chorioamniotic membranes can serve as a marker of microbial invasion of the amniotic cavity.

Toxicol Lett, 1992 May, 60(3), 307 - 14
Production of a toxic, novel mammalian metabolite of N-methylcarbazole predicted by a fungal cell model of mammalian metabolism; Yang W et al.; The formation of N-hydroxymethylcarbazole (NHMC), carbazole, 1-hydroxy-N-methylcarbazole, 2-hydroxy-N-methylcarbazole, and 3-hydroxy-N-methylcarbazole as products of mammalian liver microsomal metabolism of N-methylcarbazole (NMC) has been documented by several investigators . In previous studies in our laboratory, the fungus Cunninghamella echinulata (ATCC 9244) produced two new metabolites, 3-hydroxy-N-hydroxymethylcarbazole (3-OH-NHMC), and 3-hydroxycarbazole (3-OH-carbazole), in addition to the known mammalian metabolites, NHMC and carbazole . One of the two novel metabolites isolated from the microbial models, 3-OH-NHMC, was also identified and characterized in rat liver microsomes by analytical (HPLC) and spectral (UV and NMR) comparisons with a reference standard . The two metabolites, 3-OH-NHMC and 3-OH-carbazole, were shown to be cytotoxic to cultured rat hepatocytes as assessed by lactate dehydrogenase (LDH) leakage and neutral red (NR) uptake . These studies demonstrate the prospective potential of microbial models for predicting the formation of metabolites from drugs and other xenobiotics in mammalian systems.

Ophthalmology, 1992 May, 99(5), 800 - 4
Comparison of techniques for culturing corneal ulcers; Benson WH et al.; All consecutive cases of presumed microbial keratitis were cultured with both a platinum spatula and calcium alginate swab moistened with trypticase soy broth . Ten (77%) of the 13 culture-proven ulcers in this series showed a greater number of colonies and more confluent growth on the agar plates inoculated with a moistened swab compared with a much lower yield obtained using a platinum spatula . All culture-positive bacterial ulcers showed growth when cultured with a swab . Two ulcers that were partially treated before culturing yielded very light growth from those rows inoculated with a swab and no growth from those rows inoculated with a spatula . Two ulcers showed equal growth between the two methods . One ulcer (Actinomycetes-Streptomyces/Nocardia) had greater growth obtained with a spatula compared with a swab . This series demonstrated a significantly greater retrieval of organisms from bacterial keratitis when a calcium alginate swab moistened with trypticase soy broth was used to rub the ulcer and directly inoculate the solid agar media . The single case of filamentous bacteria suggests that a spatula may yield better organism retrieval from ulcers caused by filamentous organisms.

Transfusion, 1992 May, 32(4), 312 - 7
Impact of blood transfusion and burn injury on microbial translocation and bacterial survival; Gianotti L et al.; The role of the immune system in microbial translocation must be clarified . In these studies, the effect of blood transfusion-related immunosuppression on translocation was investigated in a burn animal model previously known to increase the gut's permeability to 14C-radiolabeled Escherichia coli . In a first experiment, Balb/c mice underwent transfusion (T) with 0.2 mL per mouse of allogeneic C3H/HeJ mouse blood 5 days prior to undergoing 30-percent burn injury (B) and simultaneous gavage (G) with 10(9) E . coli bacteria labeled with 14C . An additional six groups of Balb/c mice underwent different combinations of T, B, and G procedures (TG, BG, TB, T, B, G) . Survival rate was recorded for all groups on Day 10 . This experiment suggested that B and T, to a lesser extent, were the factors affecting survival, although the combination of T, B, and G clearly showed a synergistic effect on mortality . In a second experiment, 18 Balb/c mice belonging to TBG, BG, TG, and G groups were sacrificed 1, 4, and 24 hours after burn or gavage . The residual radioactivity and the percentage of viable bacteria were computed for mesenteric lymph nodes, spleen, liver, lungs, blood, and peritoneal fluid . Statistical analysis of the radionuclide counts recognized B as the only variable able to enhance the magnitude of 14C E . coli translocation . The percentage of viable bacteria showed that T and, more moderately, B were the factors leading to the failure of bacterial clearance in the tissues.

Clin Exp Rheumatol, 1992 May-Jun, 10(3), 271 - 83
T cell receptor usage in rheumatic disease; Richardson BC; Protection against microbial attack or invasion is a fundamental function of the immune system . Crucial to this function is the ability to distinguish "self" from the invading organism, and tolerate "self" while removing "non-self" . The ability to distinguish self from non-self is not inherent in the immune system, but rather is acquired and continuously maintained . Unfortunately, the mechanisms maintaining self-tolerance are not perfect, and at times break down . In these instances an autoimmune disease results . T cells initiate normal immune responses, and it is now clear that T cells can also initiate pathologic immune responses . In animal models, T cells produce diseases resembling rheumatoid arthritis (RA) (1-3), systemic lupus erythematosus (4-6) and progressive systemic sclerosis (7,8) . It is likely that T cells participate in human autoimmune diseases as well . The molecular basis of T cell antigen recognition has been clarified over the past decade . These advances now allow direct examination of the T cell receptor (TCR) molecules participating in autoimmune responses, and raise the exciting possibility that the cells inducing autoimmune responses may finally be identified . Selective agents might then be developed which would interfere with or inhibit the cells . Understanding these developments requires detailed knowledge of how T cells recognize antigen, and of the receptors involved in autoimmune diseases . This article reviews the current literature on T cell receptor structure, and summarizes what is currently known about the usage of specific T cell receptors in autoimmune rheumatic disease.

Toxicon, 1992 May-Jun, 30(5-6), 591 - 7
Inhibition of the proteolytic activity of hemorrhagin-e from Crotalus atrox venom by antihemorrhagins from homologous serum; Weissenberg S et al.; Antihemorrhagic proteins from Crotalus atrox serum were tested for their ability to inhibit the proteolytic activity of the hemorrhagic toxin-e from Crotalus atrox venom and of several other proteolytic enzymes: trypsin, collagenase and thermolysin . The antihemorrhagic proteins inhibited the proteolytic activity of hemorrhagin-e when tested on gelatin type I and collagen type IV, the proteolytic activity of trypsin on photofilm gelatin and the proteolytic activity of whole venom when tested on azocollagen and photofilm gelatin . The antihemorrhagins failed to inhibit the proteolytic activity of trypsin when tested on the specific synthetic substrate N-acetyl-DL-phenylalanine-beta-naphthyl ester (APNE), the activity of microbial collagenase on N-(3-{2-furyl}acryloyl)-Leu-Gly-Pro-Ala (FALGPA) or on azocollagen and the activity of thermolysin on N-(3-{2-furyl}acryloyl)-Gly-Leu amide (FAGLA) . It is tentatively suggested that the antihemorrhagins from snake blood serum are proteinase inhibitors that underwent specialization towards the neutralization of the proteolytic activity of hemorrhagic toxins.

Oral Surg Oral Med Oral Pathol, 1992 May, 73(5), 550 - 4
Postscaling bacteremia in HIV-associated gingivitis and periodontitis; Lucartorto FM et al.; Aseptic venipuncture was used to obtain samples of blood from 22 patients seropositive for human immunodeficiency virus (HIV) with gingivitis (HIV-G) and 19 HIV-seropositive patients with periodontitis (HIV-P), 15 and 30 minutes after the initiation of routine dental scaling and root planing . The presence of colony forming units in 1.2 ml aliquots of blood collected with the Isostate system (DuPont Isostat System, Doraville, Ga.) was assayed on trypticase soy blood agar . Six of the samples from HIV-G subjects were positive for colony forming units 15 minutes after scaling but not at 30 minutes . Similar evidence of bacteremia was found in seven of the HIV-P patients 15 minutes after scaling was initiated in this group, with no microbial growth detectable in samples obtained at 30 minutes . In two HIV-G and three HIV-P patients with demonstrable bacteremias a postoperative fever developed . For both HIV-G and HIV-P groups no significant difference was found between the absolute CD4 T-cell counts of nonbacteremic versus bacteremic patients (p greater than 0.05) . These observations suggest that special provisions for antibiotic prophylaxis in this patient group may be unnecessary.

Sci Total Environ, 1992 May 1, 116(1-2), 159 - 67
Monitoring of air for microbial and metal contamination at selected sites in the vicinity of Johannesburg, South Africa; Yousefi V et al.; A preliminary survey was undertaken to identify air contamination in the vicinity of industrial, residential and hospital sites . In many developing countries, poor town planning has resulted in growth of residential and commercial sites in close proximity to the industrial works, without the provision of a buffer zone . As prevailing winds blow across the industrial works to the other areas, undesirable pollution may be experienced . Before steps are taken to reduce factory emissions, the impact of the industry on the surrounding area needs to be clearly defined . In this study, the total particulate matter and the level of microbial contamination at the selected sites is reported . The elemental composition of the particulate matter is described.

Appl Environ Microbiol, 1992 May, 58(5), 1490 - 5
Identification and cloning of Bradyrhizobium japonicum genes expressed strain selectively in soil and rhizosphere; Bhagwat AA et al.; The growth of Bradyrhizobium japonicum USDA 110 and USDA 438 in soil extract-supplemented medium led to transcription of a large amount of DNA not expressed in basal medium . Strain USDA 438 was more competitive for the nodulation of soybean than strain USDA 110 . To identify and isolate DNA regions which were expressed specifically in strain USDA 438 but not in strain USDA 110 in response to soil extract or soybean root exudate, we developed a subtractive RNA hybridization procedure . Several cosmid clones which showed strain-specific gene expression were isolated from a USDA 438 gene library . Two clones enhanced competitive nodulation when mobilized to USDA 110 . The method described may be useful for identifying genes expressed in response to environmental stimuli or genes expressed differently in related microbial strains.

J Leukoc Biol, 1992 May, 51(5), 472 - 7
Mycobacterial infection primes T cells and macrophages for enhanced recruitment of neutrophils; Appelberg R; C57BL/6 mice intraperitoneally infected with Mycobacterium bovis BCG (substrain Pasteur) recruited significantly higher numbers of neutrophils after an intraperitoneal inoculation of either BCG protein antigen or of endotoxin than uninfected control mice . Antigen-induced neutrophil recruitment was mediated by T cells of both CD4+ and CD8+ phenotype and was also observed in the C5-deficient DBA/2 mouse strain . The adoptive transfer of immune serum did not prime mice for enhanced antigen-mediated recruitment of neutrophils . The endotoxin-mediated recruitment of neutrophils was also enhanced in infected as compared to uninfected DBA/2 mice . Finally, endotoxin-pulsed purified macrophages from infected C57BL/6 mice recruited higher numbers of neutrophils than endotoxin-pulsed macrophages from normal mice in an adoptive transfer to peritoneal cavities of naive recipient mice . These data show that during mycobacterial infection, T cells and macrophages are primed for recruitment of neutrophils after being triggered in specific or nonspecific ways . This may represent a means to cope with secondary infections by allowing for extensive neutrophil infiltration readily upon microbial challenge.

J Biotechnol, 1992 May, 23(3), 291 - 301
Production of recombinant human interferon-alpha 1 by Escherichia coli using a computer-controlled cultivation process; Yang XM et al.; Genetically engineered E . coli K12 BMH-71-18 with plasmid PBV-867 was used for constitutive expression of human interferon-alpha 1 (IFN) with a defined medium . A manual, time-based, fed-batch cultivation process produced a cell density of 26.3 g l-1 (OD550 89), an IFN activity of 1.55 x 10(8) IU l-1 and a specific IFN productivity of 0.65 x 10(6) IU g-1 . An analysis was conducted to characterize the problems involved in the high density microbial processes of recombinant protein production . The strategy suggested by the analysis is to establish a nutrient feeding profile that improves both the plasmid stability and the overall productivity of IFN . The nutrient feeding procedure developed here was based on the growth dynamics and a glucose consumption model . By using this procedure to continuously supply nutrients during cultivations, cell density reached 58 to 80 g l-1 and the specific IFN productivities of these runs were increased over that of the manual process . Nutrient feeding rates were found to affect the specific IFN productivity substantially . The optimized process achieved an IFN activity of 1.26 x 10(9) IU l-1, a cell density of 58 g l-1 and a specific IFN productivity of 2.2 x 10(7) IU g-1 . More significantly, the overall productivity IU l-1 h-1 of the optimized, computer-controlled cultivation process was increased 12.9-fold over that of the manual cultivation process.

Comp Biochem Physiol C, 1992 May, 102(1), 125 - 8
The involvement of collagenase in the necrosis induced by the bites of some spiders; Atkinson RK et al.; 1 . The midgut extracts of 13 Australian spider species produced cellular disruption in mouse skin in tissue culture conditions . 2 . Microbial collagenase and the venoms of some of these species had similar effects . 3 . Five venoms also caused severe dermonecrosis in living mice . 4 . Pre-mixing the venoms with L-cysteine caused complete in vivo and partial in vitro inhibition of their effects . 5 . It was concluded that collagenase is a major factor in the aetiology of necrotic arachnidism.

Arch Biochem Biophys, 1992 May 1, 294(2), 440 - 5
Purification and properties of an aminopeptidase from rat-liver cytosol; Hiroi Y et al.; An aminopeptidase was purified from the rat-liver cytosolic fraction to apparent electrophoretic homogeneity . The enzyme is a monomeric protein of 95 kDa, having an isoelectric point of 4.9 . Amino acid analyses indicate that the enzyme is rich in acidic amino acids and is poor in cysteine . The enzyme hydrolyzed a broad spectrum of amino acid beta-naphthylamides at a neutral pH . The enzyme also hydrolyzed di-, tri-, and oligopeptides, including physiologically active peptides such as enkephalins and Met-Lys-bradykinin . The enzyme was inhibited by metal-chelating agents, sulfhydryl-reactive reagents, N-P-tosyl-L-phenylalaninechloromethyl ketone, N-P-tosyl-L-lysinechloromethyl ketone, and puromycin but not by protease inhibitors of microbial origin . The enzyme was activated by the addition of Co2+ and sulfhydryl compounds . The aminopeptidase enhanced proteolysis when the enzyme was added to the protease assay system with purified rat-liver cytosolic neutral protease, suggesting the cooperative action of aminopeptidase in the overall process of protein degradation.

Ann N Y Acad Sci, 1992 Apr 30, 641, 21 - 36
Field studies on the sick building syndrome; Hodgson M; Field studies of the sick building syndrome have generally used questionnaires developed to define symptoms present over weeks and months, such as those asking " . . . do you usually . . .?" Although such studies have implicated ventilation systems as a major contributor to indoor air quality complaints, no specific exposures have been identified . An alternative approach is based on the short-term quantification of symptoms and characterization of the indoor environment with direct-reading or short-term sampling techniques . This paper summarizes the development of such a method in two studies in problem buildings and its subsequent application in a study in nonproblem buildings . The method correctly identified the postulated cause in a first building and generated a hypothesis for intervention in the second . In the nonproblem buildings, the levels of complaints appear related to the levels of VOCs, lighting, hours spent at desks, and crowding . This approach has suggested that dose-response relationships do exist in the sick building syndrome . Weaknesses of this approach include an inability to adequately address microbial characterization of indoor environments and the social and organizational predictors of complaints that are recognized to be of importance.

Rev Prat, 1992 Apr 15, 42(8), 960 - 5
{Infectious endophthalmitis}; Salvanet-Bouccara A et al.; Bacterial endophtalmitis is a disastrous postoperative complication of any intraocular surgery which can lead to blindness . With prompt endocular taps for appropiate laboratory investigations, the use of large spectrum antibiotics with good intraocular penetration, the intraocular injections of antibiotics, most of the eyes can be salvaged . Although it is unlikely that postoperative microbial endophthalmitis can be avoided entirely, all efforts should be made to reduce the incidence of this complication . Under this point of view, in addition to the available sterile techniques during the surgery, the topical and systemic antibiotic prophylaxis requires that carefully controlled studies be performed on very large numbers of patients to attain statistical validity.

Rev Prat, 1992 Apr 15, 42(8), 955 - 9
{Non herpetic keratitis}; Hoang-Xuan T; Nonherpetic keratitis includes keratitis caused by other viruses, and bacterial, fungal, and acanthamoebic keratitis . Epidemic keratoconjunctivitis, one of the most common corneal manifestations induced by nonherpetic viruses, has usually a good outcome . Conversely, non viral keratitis has more severe complications . Early clinical and microbial diagnosis are the keystones to treat successfully these keratitis . Diagnostic and therapeutic principles are detailed in this review.

Am J Surg, 1992 Apr, 163(4), 417 - 21
Untreated diabetes mellitus promotes intestinal microbial overgrowth; Roza AM et al.; Gastrointestinal dysfunction is a common secondary complication of insulin-dependent diabetes mellitus, yet its etiology is unclear . Enteric microbial overgrowth may play a role . To quantitate the changes in mucosal-adherent enteric microbial populations in untreated diabetes mellitus and to assess the impact of two forms of insulin replacement therapy upon enteric microbial populations, age-matched male Lewis rats were rendered diabetic by the administration of intravenous streptozotocin (55 mg/kg) . After diabetes was confirmed (blood glucose level greater than 250 mg/dL), rats were divided into three groups: no treatment (no insulin), treatment with daily insulin to maintain normoglycemia (3 to 7 units of protamine zinc insulin subcutaneously), or transplantation with a vascularized heterotopic duct-ligated pancreatic isograft . After 1 month, rats were killed, and segments of the proximal, middle, and distal small bowel were obtained . Mucosal samples were rinsed in phosphate-buffered saline to remove nonadherent bacteria prior to aerobic and anaerobic culturing . Microbial recovery was expressed as the log10 colony-forming unit/mg tissue wet weight . Untreated diabetes resulted in an overgrowth of mucosal-associated small bowel aerobic and anaerobic microbial populations compared with populations in normal nondiabetic age-matched control rats . Insulin treatment and pancreatic transplantation prevented microbial overgrowth in the diabetic small intestine . Pancreatic transplantation resulted in strict normoglycemia equivalent to that in nondiabetic control rats, whereas insulin treatment resulted in slightly higher blood glucose levels at sacrifice and wide fluctuations in blood glucose levels compared with nondiabetic control rats . These data suggest that sustained normalization of glucose levels is not required to prevent microbial overgrowth in diabetic rats.

J Mol Biol, 1992 Apr 5, 224(3), 847 - 59
The folding of an enzyme . VI . The folding pathway of barnase: comparison with theoretical models; Serrano L et al.; The sequence of events in the refolding pathway of barnase has been analysed to search for general principles in protein folding . There appears to be a correlation between burying hydrophobic surface area and early folding events . All the regions that fold early interact extensively with the beta-sheet . These interactions involve predominantly hydrophobic interactions and the burial of very extensive hydrophobic areas in which multiple, close, hydrophobic-hydrophobic contacts are established around a central group of aliphatic residues . There is no burial of hydrophilic residues in these regions; those that are partly screened from the solvent make hydrogen bonds . All the regions or interactions that are made late in the folding pathway do not make extensive contacts with the beta-sheet . Their buried hydrophobic regions lack a central hydrophobic residue or residues around which other hydrophobic residues pack . Further, in some of these regions there is an extensive burial of hydrophilic residues . The results are consistent with one of the earlier events in protein folding being the local formation of native-like secondary structure elements driven by local hydrophobic surface burial . A possible candidate for an initiation site is a beta-hairpin between beta-strands 3 and 4 that is conserved in the microbial ribonuclease family . A comparison of structures in this family shows that those regions that can be superimposed, or have sequence homology, correspond to elements of structure that are formed and interact with each other early in the folding pathway, suggesting that some of these residues could be involved in directing the folding process . The data on barnase combined with results from other laboratories suggest the following tentative conclusions for the refolding of small monomeric proteins . (1) The refolding pathway is, at least in part, sequential and of compulsory order . (2) Secondary structure formation is driven by local hydrophobic surface burial and precedes the formation of most tertiary interactions . These elements are then stabilized and sometimes elongated by tertiary interactions . It is plausible that there are stop signals encoded in the linear sequence that prevent the elongation of isolated secondary structure elements in solution to a larger extent than is found in the folded protein . (3) Many tertiary interactions are not very constrained in the intermediate but become more and more defined as the hydrophobic cores consolidate, loop structures form and the configuration of surface residues takes place . The interactions between different elements of secondary structure are the last ones to be consolidated while the interactions within the secondary structure elements are consolidated earlier.(ABSTRACT TRUNCATED AT 400 WORDS)

Food Chem Toxicol, 1992 Apr, 30(4), 333 - 40
Propionic acid and the phenomenon of rodent forestomach tumorigenesis: a review; Harrison PT; Propionic acid (PA) is widely used as an antifungal agent in food . It is present naturally at low levels in dairy products and occurs ubiquitously, together with other short-chain fatty acids (SCFA), in the gastro-intestinal tract of humans and other mammals as an end-product of the microbial digestion of carbohydrates . It has significant physiological activity in animals . PA is irritant but produces no acute systemic effects and has no demonstrable genotoxic potential . Rats receiving PA at 4% in the diet develop hyperplastic lesions and tumours of the forestomach . Such changes are also reported to have been produced by a variety of other chemicals, mechanical and chemical irritants, parasites, and even various dietary insufficiencies or imbalances . Evidence suggests that repeated or persistent damage to cells of the forestomach epithelium and associated proliferative responses may be a common factor in rodent forestomach tumorigenesis . Although humans do not have a forestomach, the mouth, pharynx and oesophagus are lined with similar epithelium and thus are potential target organs . However, food contact time is considerably less in these organs than in the rodent forestomach . On current evidence, PA cannot be considered a carcinogenic risk to humans; nevertheless, to determine a safe level of dietary exposure it is suggested that no-observable-effect levels should be determined for epithelial cell damage and proliferative responses in the squamous mucosa of laboratory animals, particularly in those parts of the gastro-intestinal tract having a counterpart in humans, such as the pharynx and oesophagus.

Ther Umsch, 1992 Apr, 49(4), 216 - 21
{Infectious sinusitis and otitis}; Krause M; Insight into the pathogenesis and knowledge of the microbial flora provide the basis for the treatment of sinus and ear infections . Reduced oxygen tension and impaired mucociliary transport are important factors that influence the pathogenesis of both acute and chronic sinusitis and otitis . Therefore, topical decongestion and antibiotic regimens belong to the main therapeutic principles . The choice of an antibiotic for treatment of acute infections is usually empiric; however, in chronic and recurrent infections identification of the microbiology by fluid aspiration from the sinus or middle ear is desirable before long-term antibiotic therapy is initiated . It is also important to recognize underlying predisposing conditions such as nasal polyps, anatomic deformities or tooth abscesses which should be corrected to prevent further recurrences . External otitis is a painful condition seen most frequently in the swimming season (swimmer's ear) and is often associated with the use of cotton swabs . Repeated removal of debris from of the external canal and ototopical antibiotics are mostly successful; however, in severe cases like in necrotizing external otitis antibiotic therapy is indicated.

Immun Infekt, 1992 Apr, 20(2), 36 - 8
{Microbial diagnosis of atypical mycobacteria}; Rusch-Gerdes S et al.; The introduction of the radiometric system in the diagnostic of tuberculosis caused an increase of positive specimens and shortened the time of detection markedly . This is true for strains of tuberculosis complex and especially atypical mycobacteria . The majority of these is highly resistant to drugs . Therefore, the conventional method of susceptibility tests gives no relevant results for therapy . These are obtained when combinations of drugs are tested . The most important character of atypical mycobacteria is optional pathogenicity . This is why one has to decide for each isolation whether an infection has to be assumed or a colonization only . Atypical mycobacteria are present in the environment of men and are able to multiply under unfavourable conditions . Therefore, they are a potential hazard for men.

Appl Environ Microbiol, 1992 Apr, 58(4), 1326 - 34
Physicochemical and structural investigation of the surfaces of some anaerobic subgingival bacteria; Cowan MM et al.; The surfaces of nine clinical isolates of Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, and Peptostreptococcus micros and that of laboratory strain P . gingivalis W83 were studied by using contact angle measurements, X-ray photoelectron spectroscopy, infrared spectroscopy, microelectrophoresis of whole cells, and transmission electron microscopy of whole and sectioned cells . P . intermedia strains were hydrophilic, as judged from their small water contact angles, and had highly negative zeta potentials, consistent with the presence of a prominent ruthenium red (RR)-staining layer and fibrillar appendages which are probably partly carbohydrate . The two clinical isolates of P . gingivalis were also hydrophilic and highly negatively charged despite the presence of prominent fibrils, which usually yield less negative zeta potentials . This finding suggests that the RR-staining layer dominates the suspension characteristics of P . gingivalis and P . intermedia strains . P . gingivalis W83 had no demonstrable fibrils and a morphologically distinct RR-staining layer, and it was more hydrophobic than the two clinical isolates of P . gingivalis . P . micros isolates were hydrophobic and much less negatively charged than the other species . The A . actinomycetemcomitans strains displayed long, prominent fibrils and a very thin RR-staining layer, which resulted in high hydrophobicity but distinctly different zeta potentials for the two . Physicochemical data on microbial cell surfaces usually have clear and predictable relationships with each other . For the strains in this study that did not follow these relationships, their aberrant behavior could be explained as due to a masking effect caused by specific surface architecture . We conclude that this combined analysis provides a detailed image of subgingival bacterial surface architecture.

Wei Sheng Wu Xue Bao, 1992 Apr, 32(2), 148 - 50
{The characterization of mutant No . 68 from midecamycin producing strain S . mycarofaciens 1748}; Wang Y et al.; A stable mutant No . 68 was obtained by treatment of S . mycarofaciens 1748 spores at high temperature . The electromicroscopic examination has shown that the mutant No . 68 and parent strain 1748 both have the spore chains of the spiratype . The spores of both strain are cylindrical in shape . The only difference is that the spores of the mutant No . 68 are of smooth surface, but the 1748 are of thorny . The physiological characteristics of both strains are also very similar with slight differences in utilization of few carbon sources and in cultural characters in few medium . Feeding experiment has shown that the mutant No . 68 was blocked in the formation of the macrolide lactone in the midecamycin biosynthetic pathway . This suggested that the mutant No . 68 might be a polyketide synthase genes deficient mutant . The ability of the mutant No . 68 to convert spiramycin into 4"-propionylspiramycin indicated that the mutant No . 68 contained the midecamycin 4"-propionyltransferase and could be used for microbial bioconversion of spiramycin into 4"-propionylspiramycin.

J Rheumatol Suppl, 1992 Apr, 33, 98 - 104
The role of infection in chronic arthritis; Inman RD; The hypothesis that in arthritis an infectious agent functions at least as a triggering factor, if not a perpetuating one, has inspired decades of clinical investigation . Increasingly these studies are using more sophisticated tools of molecular biology which are applied in microbiology, immunology and immunogenetics . In the spondyloarthropathies these newer techniques are defining the molecular bases for the interplay of microbial antigen and the MHC antigens . The clues to provocative antigens are still elusive, although the class II MHC susceptibility is becoming clarified . Both viral and mycobacterial antigens are being examined in rheumatoid arthritis, but definitive answers are still lacking.

J Dent Res, 1992 Apr, 71 Spec No, 905 - 7
Technical advances in intra-oral model systems used to assess cariogenicity: experimental design and analysis (reactor paper); Stephen KW; In situ cariogenicity-testing models must show evidence of compliance with valid clinical parameters, and this has been achieved with respect to pyrophosphate-, monofluorophosphate-, and zinc citrate trihydrate-containing dentifrices, where earlier in vitro studies failed to predict clinical efficacy . Parameters for validity testing should include the use of enamel fluoride uptake, plaque and/or saliva fluoride assessments, re-/demineralization assays of appliance-borne enamel slabs or slices, and plaque microbial, biochemical, and pH studies . Model reliability must be capable of withstanding repeat calibration experiments where the dosage, frequency of application, and/or duration of exposure to a new product may be varied . Furthermore, the number of enamel slabs/slices carried per appliance (and the number of artificial caries lesions per enamel insert) requires to be defined . Such studies should be repeated, but whether in the same or different subjects, or with or without cross-over, has to be determined . However, the capability of reproducing a clinically proven dose-response is essential . Models must be sensitive enough to detect changes in any test product F-concentration, but only equivalence claims should be permitted . Thus, superiority cannot be established, since accuracy may not be assumed beyond the upward limits of a clinically validated range . Finally, models should not be so exclusive in design as to preclude independent verification of their findings.

J Dent Res, 1992 Apr, 71 Spec No, 822 - 7
The ICT in situ experimental model in dental research; Koulourides T et al.; The intra-oral cariogenicity test (ICT) in situ experimental model was introduced in 1964 for the study of caries on sample enamel in the human mouth . Slabs of human or bovine enamel are mounted with a Dacron gauze cover in the acrylic flanges of prosthetic appliances . The extent of enamel demineralization or remineralization of lesions is assessed from surface microhardness measurements and microradiography of the enamel sections . The ICT model offers the potential of studying various parameters related to caries . This publication presents a typical ICT study comparing the cariogenicity of 10% sucrose solutions containing 1, 3, 10, and 30 ppm F with that of the control solution, 10% sucrose (without fluoride) . The treatments were applied to the ICT as 10-minute extra-oral immersions . The results indicate: (1) a strong effect of F in decreasing demineralization of sound enamel and increasing remineralization of pre-softened enamel in the ICT; (2) pronounced resistance to a subsequent in vitro acid test; (3) pronounced F incorporation into pre-softened enamel; and (4) a characteristic acid-resistant zone, as seen in microradiographs, associated with exposure to F . This in situ model enables one to study experimental caries with repeated testing of enamel that follows the development and/or the regression of subsurface enamel lesions, F incorporation, increased acid resistance, cariogenicity of substrates, and other parameters of caries that can be assessed under standard conditions of tooth substrate and microbial sheltering.

Immunobiology, 1992 Apr, 184(4-5), 295 - 310
Class II MHC molecules and monocytes/macrophages in the respiratory system of conventional, germ-free and interferon-gamma-treated rats; Steiniger B et al.; The localization of I-A-like class II major histocompatibility complex (MHC) molecules and cells of the monocyte/macrophage lineage was studied immunohistologically in the trachea and lungs of conventional, specified pathogen-free (SPF) and germ-free rats . In the three groups of animals I-A-like class II MHC molecules occurred in epithelia of the bronchus-associated lymphatic tissue (BALT), in B lymphocytes, in dendritic-shaped and elongated interstitial cells and in type II pneumocytes . Conventional and SPF rats were distinguished from germ-free animals only by the larger number of class II MHC-positive respiratory epithelial cells in the lower trachea and main bronchi . The distribution of monocytes/macrophages (ED1-positive cells) did not differ between the groups . After systemic treatment of SPF rats with interferon-gamma class II MHC molecules were newly induced in all respiratory epithelia and in the endothelium of large vessels . In addition, interferon-gamma sometimes led to pulmonary infiltration and caused class II-positive activated monocytes to accumulate in medium-sized pulmonary vessels and in alveolar capillaries . It is concluded that the microbial status does not qualitatively alter the distribution of class II MHC molecules and monocytes/macrophages in rat respiratory organs . Interferon-gamma can, however, provoke profound changes.

Trends Biochem Sci, 1992 Apr, 17(4), 147 - 50
Mammalian hormones in microbial cells; Lenard J; Hormones and hormone-binding proteins resembling those of vertebrates are widespread in fungi, yeast and bacteria . Functional responses of microbial cells to mammalian hormones have also been found . The evolutionary roots of the vertebrate endocrine system may, therefore, be far more ancient than is generally believed.

Lab Invest, 1992 Apr, 66(4), 437 - 43
Histopathologic and immunohistochemical changes in gut-associated lymphoid tissues after treatment of rabbits with dexamethasone; Roy MJ et al.; Corticosteroids cause impaired cell-mediated immunity which may encourage development of gastrointestinal and respiratory infections . In order to better understand the effects of corticosteroids on gastrointestinal immunity, immunological and histological changes in gut-associated lymphoid tissues were examined after intravenous administration of dexamethasone to rabbits . In treated animals, lymphoid domes and follicles were considerably reduced in size, and the dome epithelial layer was markedly depleted of M cells and lymphocytes . There were numerous open lesions at the luminal surface of dome epithelium, consistent with necrosis of M cells, and a striking depletion of follicular B cells in treated animals . These immunologic and histologic effects of corticosteroids could have found profound, deleterious effects on mucosal immune responses and host resistance to microbial infections.

Clin Microbiol Rev, 1992 Apr, 5(2), 101 - 19
Human infections due to Malassezia spp; Marcon MJ et al.; The genus Malassezia contains three member species: Malassezia furfur and Malassezia sympodialis, both obligatory lipophilic, skin flora yeasts of humans, and Malassezia pachydermatis, a nonobligatory lipophilic, skin flora yeast of other warm-blooded animals . Several characteristics suggest the basidiomycetous nature of these yeasts, although a perfect stage has not been identified . Classically, these organisms are associated with superficial infections of the skin and associated structures, including pityriasis versicolor and folliculitis . Recently, however, they have been reported as agents of more invasive human diseases including deep-line catheter-associated sepsis . The latter infection occurs in patients, primarily infants, receiving parenteral nutrition (including lipid emulsions) through the catheter . The lipids presumably provide growth factors required for replication of the organisms . It is unclear how deep-line catheters become colonized with Malassezia spp . Skin colonization with M . furfur is common in infants hospitalized in neonatal intensive care units, whereas colonization of newborns hospitalized in well-baby nurseries and of older infants is rarely observed . Catheter colonization, which may occur without overt clinical symptoms, probably occurs secondary to skin colonization, with the organism gaining access either via the catheter insertion site on the skin or through the external catheter hub (connecting port) . There is little information on the colonization of hospitalized patients by M . sympodialis or M . pachydermatis . Diagnosis of superficial infections is best made by microscopic examination of skin scrapings following KOH, calcofluor white, or histologic staining . Treatment of these infections involves the use of topical or oral antifungal agents, and it may be prolonged . Diagnosis of Malassezia catheter-associated sepsis requires detection of the organism in whole blood smears or in buffy coat smears of blood drawn through the infected catheter or isolation of the organism from catheter or peripheral blood or the catheter tip . Culture of M . furfur from blood is best achieved with Isolator tubes and plating onto a solid medium supplemented with a lipid source . Appropriate treatment of patients requires removal of the infected catheter with or without temporary stoppage of lipid emulsions; administration of antifungal therapeutic agents does not appear to be necessary . Because many patients who develop Malassezia catheter-associated sepsis have severe underlying illnesses, caution must be exercised in attributing all clinical deterioration to Malassezia infection . Our better understanding of how these organisms cause disease awaits the development of a useful typing scheme for epidemiologic studies and further studies on microbial virulence factors and the role of the immune response in pathogenesis.

J Periodontol, 1992 Apr, 63(4 Suppl), 338 - 55
Host responses in periodontal diseases: current concepts; Genco RJ; In periodontal diseases, bacteria trigger inflammatory host responses which, along with the direct destructive effects of the bacteria, cause most of the tissue destruction . Periodontal inflammatory responses are, by and large, immunologic, and our understanding of these reactions has been advanced by the explosion of knowledge in immunobiology, some of which is discussed in this review . Understanding the role of immune cells and their regulatory cell surface molecules such as the MHC, CD antigens, and receptors, as well as knowledge of effector systems set into motion such as phagocytes and cytotoxic T-cells, and the effector molecules such as antibodies, complement, and cytokines, have led to better understanding of the complex pathogenesis of periodontal disease . The role of mediators including the matrix metalloproteinases, proteoglycans, the kinins and anaphylatoxins, and low molecular weight mediators including products of arachidonic metabolism is beginning to be elucidated in periodontal disease . Important avenues of research for development of diagnostic tests based upon host response are apparent . For example, tissue products released during periodontal inflammation including the metalloproteinases, elastase, cytokines, prostaglandins, antibodies, and complement components may provide the basis for future diagnostic indicator tests . The recognition that the neutrophil/antibody/complement axis is critical for protection against periodontal bacteria and that abnormalities in this system often lead to increased periodontal susceptibility provide approaches for the development of diagnostic tests assessing risk . A group of factors which are negative regulators of inflammation including TGF-beta, gamma-interferon, and IL-1 receptor antagonist provide potential for assessment of periodontal disease in remission or in the healing phase . Finally, factors such as HLA associations and the molecular basis for neutrophil abnormalities may provide genetic markers for periodontal disease susceptibility . Diagnostic factors based upon host response measures offer great potential for predicting host susceptibility and will likely be used in combination with microbial diagnostics which identify specific infecting organisms.

J Periodontol, 1992 Apr, 63(4 Suppl), 322 - 31
The bacterial etiology of destructive periodontal disease: current concepts; Socransky SS et al.; The interpretation of diagnostic tests for the detection of subgingival bacterial species is dependent on knowledge of the microbial etiology of destructive periodontal diseases . Specific etiologic agents of these diseases have been sought for over 100 years; however, the complexity of the microbiota, an incomplete understanding of the biology of periodontal diseases, and technical problems have handicapped this search . Nonetheless, a number of possible pathogens have been suggested on the basis of their association with disease, animal pathogenicity, and virulence factors . The immunological response of the host to a species and the relation of successful therapy to the elimination of the species have also been used to support or refute suspected periodontal pathogens . Current data suggest that pathogens are necessary but not sufficient for disease activity to occur . Factors which influence activity include susceptibility of the individual host and the presence of interacting bacterial species which facilitate or impede disease progression . Recent studies have attempted to distinguish virulent and avirulent clonal types of suspected pathogenic species and seek transmission of genetic elements needed for pathogenic species to cause disease . Finally, the local environment of the periodontal pocket may be important in the regulation of expression of virulence factors by pathogenic species . Thus, in order that disease result from a pathogen, 1) it must be a virulent clonal type; 2) it must possess the chromosomal and extra-chromosomal genetic factors to initiate disease; 3) the host must be susceptible to this pathogen; 4) the pathogen must be in numbers sufficient to exceed the threshold for that host; 5) it must be located at the right place; 6) other bacterial species must foster, or at least not inhibit, the process; and 7) the local environment must be one which is conducive to the expression of the species' virulence properties.

J Trop Pediatr, 1992 Apr, 38(2), 83 - 5
Malarial parasitaemia in febrile children with sickle cell anaemia; Okuonghae HO et al.; One-hundred-and-sixty-six episodes of fever in 162 children with sickle cell anaemia (SCA) aged 6 months to 16 years, presenting to the children emergency room of the University of Benin Teaching Hospital, Nigeria with rectal temperature greater than or equal to 38.3 degrees C were studied for malarial parasitaemia . Non-sicklers of similar ages and with similar temperatures were also studied as controls . Malarial parasitaemia was documented in 9 per cent of children with sickle cell anaemia, and 29 per cent of controls (P less than 0.0001) . Bacteraemia occurred in 33 per cent of children with SCA and 26 per cent of controls (P greater than 0.10) . Bacteraemia was, therefore, the commonest cause of pyrexia in febrile children with sickle cell anaemia on antimalarial prophylaxis . It is suggested that children with SCA on regular anti-malarial prophylaxis who present with significant pyrexia should be carefully screened for bacterial infection and appropriate anti-microbial therapy instituted.

Eur Respir J, 1992 Apr, 5(4), 418 - 23
High prevalence of asthma in patients with bronchiectasis in Hong Kong; Ip MS et al.; Eighty five Chinese patients with diffuse or localized bronchiectasis (non-cystic fibrosis) were studied regarding the prevalence of asthma . Twenty three of the 85 had concomitant asthma, diagnosed by history and reversibility on lung function testing either spontaneously or after bronchodilator . None fulfilled the diagnostic criteria of allergic bronchopulmonary aspergillosis (ABPA) . Asthma preceded the onset of bronchiectasis in 13 patients and developed after long duration of bronchiectasis in seven, while the temporal onset could not be differentiated in three patients . Patients with both asthma and bronchiectasis had inferior spirometric values, higher prevalence of bronchial hyperresponsiveness to methacholine, higher prevalence of skin atopy, elevated serum immunoglobulin E (IgE), and more sputum eosinophilia, compared with their non-asthmatic counterparts . Possible mechanisms by which asthma and bronchiectasis predispose to each other include asthmatic obstruction contributing to development of bronchiectasis, and sensitization of airways with increased lability due to microbial colonization of the ectatic bronchial tree.

J Med Microbiol, 1992 Apr, 36(4), 229 - 38
Adherence and entry of Borrelia burgdorferi in Vero cells; Hechemy KE et al.; Adherence to and entry of the parasite into the host is one of the essential elements of microbial pathogenicity . We investigated the adherence to and entry into primate kidney epithelial (Vero) cells of Borrelia burgdorferi by radiolabelling techniques, immunofluorescence and electronmicroscopy . The attachment to and subsequent entry of both untreated and heat (50 degrees C)-treated B . burgdorferi into Vero cells occurred at cell-surface sites associated with aggregated coated pits . In contrast, there was minimal attachment of spirochaetes heated at 60 degrees C . Radiometric studies showed that, with untreated cells, there was incorporation of both 14C-glucose-1-phosphate and 14C-thymidine, whereas with the 50 degrees C-treated spirochaetes only glucose-1-phosphate was incorporated, and with the 60 degrees C-treated spirochates neither radionuclide was incorporated . Spirochaetes heated at 50 degrees C or 60 degrees C did not grow at 35 degrees C in culture medium . These results suggest that the presence of certain metabolic activities of the spirochaete but not viability (ability to grow) are necessary for the attachment process . After entry of untreated B . burgdorferi, most of the spirochaetes were either free in the cytoplasm or tightly bound to the host membrane . In contrast, 50 degrees C-treated spirochaetes remained bound to host membrane in large phagosome-like vesicles.

Proc Natl Acad Sci U S A, 1992 Apr 1, 89(7), 3155 - 8
Induction of heat shock protein closely correlates with protection against Toxoplasma gondii infection; Nagasawa H et al.; Heat shock proteins (HSPs) are evolutionarily highly conserved polypeptides that appear to be produced by many cells to preserve cellular functions under a variety of conditions of stress, including infections . We report that a 65-kDa HSP is present in mouse peritoneal cells that have been infected with a low-virulence (Beverley) strain of Toxoplasma gondii, as determined by electroblot assay using a monoclonal antibody specific for microbial HSP65 . This HSP is, however, not expressed when infection occurs with the high-virulence RH strain of T . gondii . Furthermore, HSP was demonstrable in mice that acquired resistance against infection with a lethal dose of bradyzoites of the Beverley strain or even of an inoculum of a highly virulent strain of T . gondii (RH) . From these results, it can be suggested that HSPs play an important role in developing effective defenses that include effective immune responses against infection with Toxoplasma parasites in vivo.

Clin Exp Immunol, 1992 Apr, 88(1), 62 - 7
T and B cell responses following immunization with tetanus toxoid in IgA nephropathy; Fortune F et al.; The B and T cell responses were investigated in IgA nephropathy before and after immunization with tetanus toxoid (TT) . Both IgA and IgG anti-tetanus toxoid antibodies were elicited, but the IgA antibodies were significantly greater in patients (92.6 +/- 11.7 ELISA units) than in the controls (49.2 +/- 7.5 ELISA units) . This was associated with a significantly greater proportion of IgA+ B cells in patients than controls before immunization . However, a significant increase in the proportion of IgA1 binding CD4 and CD8 cells was also found . The proportion of CD3 cells with gamma delta T cell receptors (CD3+TCR gamma delta +), was significantly greater before immunization in the IgA nephropathy patients (37.0% +/- 2.4), compared with controls (10.0% +/- 2.3; P less than 0.001) . Immunization with TT further enhanced the CD3+TCR gamma delta + cells in patients to 45.8% +/- 7.2 compared with controls (16.3% +/- 4.5), with a corresponding decrease in CD3+TCR alpha beta + cells in the patients (P less than 0.001) . CD3+TCR gamma delta + cells are upregulated by common microbial antigens and clinical exacerbations of IgA nephropathy are frequently associated with mucosal infections and a rise in serum IgA concentration . The increased TCR gamma delta expression may be responsible for the enhanced IgA antibody response in IgA nephropathy . The increase in IgA antibodies may than exert a controlling effect by binding to augmenting T cells and thereby inhibiting their function.

Clin Exp Immunol, 1992 Apr, 88(1), 149 - 56
Functional heterogeneity of human T cell clones from atopic and non-atopic donors; Chambers CA et al.; Several distinct T helper (TH) subsets have been identified, based on the cytokines secreted . Recently, it has been demonstrated that these subsets can regulate the isotype of humoral responses . To investigate the possible differences in TH subsets between atopic donors which have elevated serum IgE and donors with normal serum IgE, we examined series of human TH cell clones . A total of 31 and 22 CD4+ T cell clones from the atopic and non-atopic donors, respectively, were characterized for the ability to help for IgE synthesis in vitro . T cell clones generated with allergen AgE from the atopic donor were autoreactive and all induced IgE synthesis . Tetanus toxoid-specific (TT) and phytohaemagglutinin clones were generated from both donors . There was significant heterogeneity between the T cells isolated with different stimuli from the same atopic donor . Also, there was a significant difference in the number of T cells generated from the atopic versus the non-atopic donor which helped for IgE, although there was no significant difference between the total number of T cells able to help for immunoglobulin synthesis of other isotypes . Most importantly, there was a higher frequency of clones able to support IgE synthesis between TT-specific T cell clones generated from the atopic versus the non-atopic donor . These results suggest that there are changes in subsets of TH cells specific for microbial antigens as well as allergens in atopics, which may have important implications for the aetiology of atopic disease.

Khirurgiia (Mosk), 1992 Apr, (4), 69 - 77
{A method of preparing the large intestine for surgery by using the peroral administration of a polyethylene oxide solution}; Datsenko BM et al.; A new method for preparing the large intestine for operation is suggested, it is based on oral administration of a solution of polyethylene oxides with chloramphenicol . The preparation possesses a marked hydrophilic activity, which causes inhibition of absorption processes in the lumen of the intestinal tube . This leads to accumulation of the intestinal contents and their quicker passage . Polyethylene oxides also ensure accumulation of antibiotics in the tissues of the intestinal wall . The suggested method was used to prepare the intestine for operation in 93 patients . Comparative evaluation proved its advantages according to the main clinico-laboratory criteria: the method is technically simple, reduces the period of preparation of the intestine, has no negative effect on the homeostasis values, ensures adequate preparation of the large intestine with decrease of the level of its microbial contamination . With the use of the method the number of postoperative purulent complications in interventions on the large intestine reduced.

Khirurgiia (Mosk), 1992 Apr, (4), 44 - 7
{Specific immunity in patients with inflammatory diseases of the abdominal cavity}; Perfil'ev DF; In most patients with pyoinflammatory diseases of the abdominal cavity caused by Cl . perfringens microbial associations accumulation of agglutinins occurred during the disease . In purulent abdominal processes caused by Cl . perfringens microbial associations a connection exists between the increased antibody level and wound suppuration . The rise of the antibody level was most marked, whatever the character of the bacterial associations, in patients with generalized peritonitis, abdominal abscess, and in young patients (10-40 years of age) and least in those with phlegmonous cholecystitis and in elderly patients (61-70 years of age) . Patients with destructive forms of appendicitis and individuals aged 41-60 took an intermediate position according to these values . Antibody production was weaker in patients with 5 species in the microbial association than in monoinfection . A agglutinin titer in the blood of patients beginning with 1:80 and higher should be considered diagnostic.

J Am Optom Assoc, 1992 Apr, 63(4), 243 - 8
Laboratory workup of microbial keratitis; Perrigin J; Accurate diagnosis is the key to proper management of microbial keratitis . Haphazard therapy for keratitis often results in frustration for both the doctor and the patient . Unsuccessful therapy allows the condition to linger on, and may provide the opportunity for more serious corneal complications to occur . In-office cytological and gram stain smears along with laboratory cultures, sensitivities, and endotoxin testing are essential in developing an accurate initial diagnosis and successful treatment plan for microbial keratitis.

J Anim Sci, 1992 Apr, 70(4), 1159 - 68
The effect of supplementary Aspergillus niger phytase in diets for pigs on concentration and apparent digestibility of dry matter, total phosphorus, and phytic acid in different sections of the alimentary tract; Jongbloed AW et al.; Six barrows of approximately 37 kg BW, fitted with two simple T-cannulas in the duodenum (25 cm posterior to the pylorus) and terminal ileum (12 to 15 cm anterior to the ileocecal junction), were fed two diets containing 2.1 g of P/kg in the form of phytic acid and a low intrinsic phytase activity (corn-soybean meal based diet {Diet A} or a typical Dutch diet {Diet B}) without or with supplementary microbial phytase from Aspergillus niger (var . ficuum) equal to 1,500 phytase units per kilogram of diet, in a crossover design . The apparent duodenal, ileal, and total tract (overall) digestibilities of DM, total P, and phytate P (phytic acid x .282) were calculated using both Cr-NDR (neutral detergent residue mordanted with Cr) and Co-EDTA as dual-phase markers . Concentration of total P in the ileal digesta (P less than .01) and feces (P less than .001) of pigs fed microbial phytase was lower than without this enzyme, irrespective of the diet . Ileal digestibility of total P was 18.5 and 29.8 percentage units higher (which was a 1.7- to 2.9-fold increase) due to added Aspergillus niger phytase (P less than .05) . Also, total tract (overall) digestibility increased by 27.0 to 29.7 percentage units (P less than .01) . Phytic acid concentration in the duodenal and ileal digesta of pigs receiving microbial phytase was lower (P less than .01 or .001), resulting in its higher ileal digestibility (dephosphorylation rate) by 50.1 percentage units for Diet A and by 75.4 percentage units for Diet B . Irrespective of the treatment, no phytase activity could be detected in the ileal digesta of pigs.

J Periodontol, 1992 Apr, 63(4), 270 - 3
Treponema denticola and Porphyromonas gingivalis as prognostic markers following periodontal treatment; Simonson LG et al.; Subgingival plaque samples were collected from individuals with advanced periodontitis before and 3 to 11 weeks after scaling and root planing periodontal treatment . The plaque levels of Treponema denticola and Porphyromonas gingivalis antigens were measured before and after treatment by a quantitative immunoassay procedure using monoclonal antibodies specific for these oral bacteria . A decrease in mean levels of T . denticola (P less than .05) and P . gingivalis antigens (P less than .09) were observed following periodontal therapy . Improved health, as measured by a decrease in probing depth, was associated with a decrease in T . denticola antigen (P less than .05) . These results suggest that the T . denticola levels of successfully treated sites decreased, while non-responding sites had levels of this microbial marker which were equal to or greater than the pre-treatment levels . These results provide additional evidence that T . denticola is associated with human adult severe periodontal disease, and can serve as a prognostic marker for disease recurrence.

Gastroenterology, 1992 Apr, 102(4 Pt 1), 1199 - 211
Effect of colonic inflammation on mucin inhibition of Escherichia coli RDEC-1 binding in vitro; Mack DR et al.; Intestinal mucus protects the underlying epithelium against adhesion and invasion by microbial pathogens and their products . In inflamed colonic mucosa there are both histochemical and biochemical changes in the major organic constituent of mucus, goblet cell-derived mucin . To determine if these changes result in differences in functional properties of mucin, inhibition of adherence of piliated Escherichia coli, strain RDEC-1 (serotype O15:H-), by mucin purified from distal colons of normal rabbits was compared with inhibition by mucin from colons of rabbits with dinitrochlorobenzene-induced colitis . Histology from inflamed colons revealed evidence of chronicity with a chronic inflammatory cell infiltrate, depletion of mucous glands, and branching of crypts . Mucin was purified from crude mucus of distal colonic mucosa by sequential ultracentrifugation and characterized by gel electrophoresis and amino acid analysis . The rabbit enteropathogen RDEC-1 was grown to promote expression of adherence pili . A nonpiliated mutant, strain M34, was used as a negative control . A concentration-dependent inhibition of piliated RDEC-1 binding was shown using mucins derived from both inflamed and noninflamed colons . However, equivalent dry weights of mucin purified from inflamed colons showed less inhibition of bacterial binding (10.3% inhibition +/- 5.2%; mean +/- SD) compared with mucin from normal colons (47.6% +/- 10.8%; P less than 0.05) . Mucin purified from additional animals with hapten-induced colitis but treated with the oral leukotriene B4-receptor antagonist SC-41930 showed intermediate inhibition of RDEC-1 binding (35.6% +/- 14.3%) . It is concluded that mucin derived from inflamed distal colon of rabbits failed to inhibit in vitro binding of piliated RDEC-1, and by decreasing mucosal inflammation, this functional alteration of mucin was partially reversed.

Eur J Pharmacol, 1992 Mar 12, 225(3), 203 - 7
HS-142-1, a novel nonpeptide atrial natriuretic peptide (ANP) antagonist, blocks ANP-induced renal responses through a specific interaction with guanylyl cyclase-linked receptors; Morishita Y et al.; HS-142-1, a novel microbial product, blocked 125I-labeled rat atrial natriuretic peptide (rANP) (= ANF(99-126)) binding to bovine adrenocortical membranes, where guanylyl cyclase-containing receptors are predominantly expressed . However, HS-142-1 only slightly inhibited {125I}rANP binding to bovine lung membranes where only a small portion of binding sites are coupled to guanylyl cyclase . Further, HS-142-1 only recognized the 135 kDa ANP receptor, which is considered to be the guanylyl cyclase-containing receptor based on the results obtained in affinity cross-linking studies with bovine adrenocortical and lung membranes . Under identical conditions, Atriopeptin I selectively recognized guanylyl cyclase-free receptors both in binding and affinity cross-linking experiments . When injected intravenously (1 mg/kg) to anesthetized rats, HS-142-1 abolished ANP-induced diuresis and natriuresis . These results suggest that HS-142-1 works in vivo through a specific interaction with the ANP functional receptor, and that HS-142-1 will be a powerful tool for understanding the physiological roles of ANP in distinction from its pharmacological effects.

Am J Hosp Pharm, 1992 Mar, 49(3), 615 - 8
Stability of midazolam hydrochloride in a flavored, dye-free oral solution; Steedman SL et al.; The stability of injectable midazolam hydrochloride in a solution for oral use was studied at three temperatures over 56 days . A 2.5-mg/mL oral solution was prepared from injectable midazolam hydrochloride and a flavored, dye-free syrup . Samples of solution were stored in amber glass bottles at 7, 20, or 40 degrees C . Duplicate samples were analyzed by high-performance liquid chromatography on days 0, 1, 3, 5, 14, 21, 35, and 56 . Samples were also visually inspected on each sampling day . The concentrations of all samples remained greater than 90% of the original concentration and there were no visual signs of microbial growth or changes in color, turbidity, or odor throughout the 56-day period . A 2.5-mg/mL solution of injectable midazolam in syrup was stable for 56 days at 7, 20, or 40 degrees C.

J Nat Prod, 1992 Mar, 55(3), 269 - 84
Metabolism of the Catharanthus alkaloids: from Streptomyces griseus to monoamine oxidase B; Rosazza JP et al.; More than three decades after their discovery and implementation in medicine, essentially nothing is known about the metabolism or the implications of metabolism in mechanism of action or toxicity of the Catharanthus alkaloids . The frustrating paucity of information about pathways of metabolism has limited a major source of structure-activity relationship information and has blocked a critical avenue necessary for the logical development of new and more useful Catharanthus alkaloids . Microbial transformations, peroxidases, copper oxidases, mouse and rat cytochrome P-450 systems, and mouse brain and bovine liver monoamine oxidase (MAO) preparations have been explored in the study of Catharanthus alkaloid metabolism . In this report, we present results which have clarified the involvement of enzymatic and chemically catalyzed one-electron oxidations that yield nitrogen-centered cation radicals, iminium, and carbinolamine intermediates, all of which explain how new carbon-carbon and carbon-oxygen bonds form, or break and rearrange . The dimeric Catharanthus alkaloids are recalcitrant to oxidations catalyzed by monoamine oxidases and to both normal and induced P-450 rat microsomal preparations . However, the Catharanthus alkaloids appear to be selective reversible inhibitors of MAO-B . Chemical and biochemical aspects of the metabolic transformations of dimeric Catharanthus alkaloids are reviewed together with the implications of our findings.

Recenti Prog Med, 1992 Mar, 83(3), 131 - 5
{Usefulness of microbial investigations in community-acquired pneumonia}; Putinati S et al.; Community acquired pneumonia (CAP) is a common and well known disease, however there is no definite agreement on a common diagnostic-therapeutic strategy . To evaluate the usefulness of microbial investigations in the clinical practice we performed a prospective study on 93 consecutive patients with a diagnosis of CAP . Group I consisted of 46 patients that underwent a diagnostic protocol including sputum, blood cultures and detection of specific antibodies against M . pneumoniae, adenovirus, respiratory syncytial virus, and L . pneumophila . Group II consisted of 47 patients, in which only sputum samples were collected and cultured . No significant differences concerning the aetiologic diagnosis, the outcome and the length of hospitalization were observed in the two groups . The aetiological diagnosis was obtained in 17 patients (18.3%) . As result of information obtained from microbiol tests, antibiotic therapy was changed only in 6 patients . Among the prognostic factors only a low albumin level was correlated with the length of hospitalization (p less than 0.01) . From our data, the detection of microbial aetiology should not be routinely performed in patients with CAP, but should be reserved only to the severe forms.

Appl Environ Microbiol, 1992 Mar, 58(3), 786 - 93
Microbial degradation of toluene under sulfate-reducing conditions and the influence of iron on the process; Beller HR et al.; Toluene degradation occurred concomitantly with sulfate reduction in anaerobic microcosms inoculated with contaminated subsurface soil from an aviation fuel storage facility near the Patuxent River (Md.) . Similar results were obtained for enrichment cultures in which toluene was the sole carbon source . Several lines of evidence suggest that toluene degradation was directly coupled to sulfate reduction in Patuxent River microcosms and enrichment cultures: (i) the two processes were synchronous and highly correlated, (ii) the observed stoichiometric ratios of moles of sulfate consumed per mole of toluene consumed were consistent with the theoretical ratio for the oxidation of toluene to CO2 coupled with the reduction of sulfate to hydrogen sulfide, and (iii) toluene degradation ceased when sulfate was depleted, and conversely, sulfate reduction ceased when toluene was depleted . Mineralization of toluene was confirmed in experiments with {ring-U-14C}toluene . The addition of millimolar concentrations of amorphous Fe(OH)3 to Patuxent River microcosms and enrichment cultures either greatly facilitated the onset of toluene degradation or accelerated the rate once degradation had begun . In iron-amended microcosms and enrichment cultures, ferric iron reduction proceeded concurrently with toluene degradation and sulfate reduction . Stoichiometric data and other observations indicate that ferric iron reduction was not directly coupled to toluene oxidation but was a secondary, presumably abiotic, reaction between ferric iron and biogenic hydrogen sulfide.

Semin Dermatol, 1992 Mar, 11(1), 37 - 47
Kawasaki syndrome; Wortmann DW; Kawasaki syndrome is an acute mucocutaneous syndrome of young children characterized by prolonged fever, rash, mucositis, cervical adenitis, and changes of the peripheral extremities . Unlike most other illnesses, the rash is not distinctive and is remarkable for its variable morphology, site of onset, and pattern of progression . The cause and pathogenesis of Kawasaki syndrome remain a mystery, but most investigators favor a microbial agent as the trigger, followed by an immune-mediated vasculitis that has a predilection for the coronary arteries . Serious complications include coronary artery aneurysms, aneurysmal thrombosis, and death . Aspirin has been the most widely used treatment for Kawasaki syndrome, but it has not been shown to alter the basic pathology . Treatment with aspirin plus intravenous gamma globulin can reduce the frequency of coronary artery abnormalities . Definitive therapy of Kawasaki syndrome awaits the discovery of its cause and pathogenesis.

J Oral Pathol Med, 1992 Mar, 21(3), 100 - 4
Reduction of Langerhans cells in smokeless tobacco-associated oral mucosal lesions; Daniels TE et al.; Localized absence of epithelial Langerhans cells (LC) has been shown to affect systemic immune responses, allow microbial colonization and play a possible role in carcinogenesis . Because use of smokeless tobacco is associated with abnormal oral mucosal changes and development of carcinoma, we examined lesion and control specimens from 17 current users of smokeless tobacco to determine whether lesions showed changes in LC number or antigen expression . We identified LC by immunohistochemistry with antibodies to the antigens T6, HLA-DR, HLA-DQ, and HLA-DP . Lesion specimens contained fewer LC (means of 6 LC/mm and 10 LC/mm2) than did the corresponding control specimens (means of 14 LC/mm and 30 LC/mm2), and in each pair of lesion and autologous control specimens the reduction in LC was on average 58% (range, 3% to 95%) . There were no apparent differences between lesion and control specimens in the number of LC expressing each of the four marker antigens . Reductions in LC occurred in all types of smokeless tobacco-associated lesions, regardless of increased epithelial thickness or changes in keratinization . Our data indicate that smokeless tobacco reduces the number of Langerhans cells at its site of contact with the oral mucosa.

J Anim Sci, 1992 Mar, 70(3), 915 - 23
Effect of a supply of raw or extruded rapeseeds on digestion in dairy cows; Ferlay A et al.; The influence of extruded oilseeds on total tract digestibility and ruminal digestion in dairy cows was studied in three cows fed a hay-concentrate (60.5/39.5; 3.7% fatty acids in diet on DM basis) control diet (C) or the same diet supplemented with raw (R) or extruded (ER) rapeseeds (8.0% fatty acids in diet DM) . The experimental design was a 3 x 3 Latin square design . Compared with diet C, diets containing rapeseed decreased ruminal OM digestibility (9.5%, P less than .10) and increased (P less than .05) the proportion of propionate in ruminal fluid VFA . Extrusion had no effect on DM and OM total tract digestibilities and increased (P less than .10) N digestion . Microbial N flow at the duodenum was calculated taking into account solid-adherent bacteria (SAB) and liquid-associated bacteria (LAB) . Duodenal flows of total, SAB, and LAB of OM and N did not change with diet . Extrusion of the rapeseeds did not modify (P less than .10) the proportion of bacterial N at the duodenum and had no effect on crude fiber digestibility . This trial demonstrates that rapeseeds in hay-based diets can be fed at levels of up to 14% of the diet without adversely affecting crude fiber digestibility.

Eur J Immunol, 1992 Mar, 22(3), 641 - 5
V beta repertoire in rats and implications for endogenous superantigens; Smith LR et al.; Endogenous superantigens of mice, encoded by mammary tumor virus proviral integrants, induce intrathymic deletion of entire T cell populations that express specific V beta gene products, a phenomenon proposed to be important in self-tolerance and prevention of toxic responses to exogenous microbial superantigens . Evidence for the presence of V beta selecting/deleting endogenous superantigens in other species is lacking . We report here that rats do not exhibit endogenous superantigen-induced V beta clonal deletions despite their strong response to bacterial superantigens . These findings indicate that endogenous superantigens are not obligatory in V beta repertoire shaping.

J Investig Allergol Clin Immunol, 1992 Mar-Apr, 2(2), 73 - 7
In vivo effects of OK-432, inosine pranobex and its salt components on macrophage subpopulations in spleen and peritoneum of mice during the primary humoral immune response; Zwadlo-Klarwasser G et al.; Subsets of macrophages (BM 8-, la- and esterase-positive subtypes) in the spleen and the peritoneum of mice were affected differently by immunomodulators during the humoral immune response . I.p . application of inosine pranobex (INPX), as well as of its salt moiety (DIPPACBA) and its dimethylaminopropanol (DIP) and acetamidobenzoic acid (PACBA) components, increased the number of nonspecific esterase-bearing cells in the peritoneum on day 3 . INPX and DIPPACBA stimulated the la+ macrophage on day 3, DIPPACBA the BM 8+ macrophage only on day 1 and DIP on day 5 . In spleen, DIP and PACBA had marked effects on the la+ subset in addition to a marginal effect on the BM 8+ phenotype on day 1 . DIPPACBA also influenced the BM 8+ macrophage slightly on day 1 . In contrast, the microbial product OK-432 stimulated BM 8+ and la+ macrophages in spleen markedly on day 1, but only marginally on days 3 and 5 . However, it exerted a strong effect on both subtypes in peritoneum on days 3 and 5 . OK-432 was found to be without any influence on esterase-bearing macrophages . The results show that the heterogeneity of macrophages is not only represented by subset markers, but also by their susceptibility to immunomodulators in different organs and stages of the immune response.

J Biol Chem, 1992 Feb 5, 267(4), 2157 - 63
Wortmannin, a microbial product inhibitor of myosin light chain kinase; Nakanishi S et al.; We have found that a fungal strain, Talaromyces wortmannin KY12420, produces a potent inhibitor of smooth muscle myosin light chain kinase (MLCK) . This active product, designated as MS-54, was isolated and purified from the culture broth of the fungus and identified as wortmannin . The inhibition of MLCK by wortmannin was prevented by a high concentration of ATP . The activity of the catalytic domain, which was disclosed by partial tryptic digestion, was also inhibited by wortmannin . These results suggest that wortmannin acts at or near to the catalytic site of the enzyme . It was shown clearly by kinetic analyses, preincubation studies, and dialysis experiments that the inhibitory action of wortmannin on MLCK was irreversible . Under the condition of preincubation for 3 min, 0.3 microM wortmannin inhibited the activity of MLCK, while 10 microM wortmannin had no effect on the activities of cAMP-dependent protein kinase, cGMP-dependent protein kinase, and calmodulin-dependent protein kinase II, and had little effect on protein kinase C activity . These data expressed clearly the marked selectivity of the compound for MLCK . Furthermore, wortmannin also inhibited both the phosphorylation of myosin light chain and the contraction in rat thoracic aorta stimulated with KCl, which indicates the effectiveness of the compound in the cellular level as an MLCK inhibitor.

Clin Exp Immunol, 1992 Feb, 87(2), 304 - 9
Phagocytosis of Giardia lamblia trophozoites by cytokine-activated macrophages; Belosevic M et al.; Phagocytosis of Giardia lamblia trophozoites by cytokine-activated and non-activated bone marrow-derived macrophages was examined in vitro . Macrophages treated with recombinant interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS) ingested a significantly higher number of in vitro-grown trophozoites than untreated macrophages . Maximal uptake of parasites occurred after 4 h and 6 h of incubation where 81.4% and 79.1% of macrophages were positive for trophozoites . Other cytokines tested, IL-2, IL-3, IL-4, IL-5, GM-CSF, CSF-1 and tumour necrosis factor-alpha (TNF-alpha) either alone or in combination with LPS, failed to activate macrophages to phagocytose G . lamblia . The induction of this activated macrophage anti-microbial function was achieved pharmacologically using phorbol myristate acetate (PMA) and ionophore A23187 . The giardicidal activity of macrophages activated with IFN-gamma and LPS or that induced by PMA and A23187 was inhibited by H-7, indicating the role for protein kinase C in the intracellular events following activation.

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