Bacteriological

Microbiologia, 1995 Mar, 11(1), 33 - 42
Safety aspects of "sous vide" products and prevention of microbial risks; Martens T; The diversity and quantities of vacuum packed and vacuum cooked prepared meals and menu components are rapidly growing on the European market . Because of the minimal heat processing, high water activity, absence of preservatives, and the use of many different often exotic ingredients, these products have a high risk potential . For this reason, Anglo-Saxon governments and industries are very sceptical about the safety of "sous vide" products . Industrial practice, as well as parallel tests and recent studies on inoculated packs have shown that, in many cases, it is more a potential than a real risk . Quality is the primary concern for "sous vide" products, and safety must be guaranteed by the application of the Hazard Analysis Critical Control Point (HACCP) concept, along with an adequate combination of different inhibitory factors (temperature of heating and cooling, pH, incorporation of starter cultures, bacteriocins and some particular enzymes).

Arch Oral Biol, 1995 Mar, 40(3), 199 - 207
Induction of cytoskeletal rearrangements and loss of volume regulation in epithelial cells by Treponema denticola; De Filippo AB et al.; The early responses of oral epithelial cells to the adhesion of the oral spirochaete Treponema denticola were studied as a model of microbial perturbation of the plasma membrane . KB cell (ATCC CCL 17) monolayers were incubated with T . denticola (ATCC 35405) in alpha-MEM (minimal essential medium) for periods of 1-4 h at 37 degrees C without serum . Control cultures were exposed to bacteria-conditioned alpha-MEM without serum or bacteria or to alpha-MEM alone . At the end of each incubation, detached and attached epithelial cells were harvested and analysed separately . Compared with controls, T . denticola induced in 25% of cells a two-fold, time-dependent increase of detachment by 4 h . Detached cells in both T . denticola-exposed and control cultures exhibited 25% reductions in modal diameter, did not exclude propidium iodide, did not readhere, and did not form colonies . In T . denticola-exposed cultures, a larger subset (75%) of cells remained attached to the substratum, demonstrated no significant reduction of colony-forming efficiency and excluded propidium iodide . However, these cells exhibited a 21% reduction in diameter (p < 0.05), a 60% decrease of F-actin (p < 0.001), and a 74% reduction in the proportion expressing desmoplakin II (p < 0.01) after exposure to T . denticola . Flow cytometry showed a small (14%) but significant (p < 0.001) reduction in mean fluorescence intensity due to keratin expression in T . denticola-treated cultures . Exposure of cells to anisosmotic media demonstrated that, in contrast to controls, cultures challenged by bacteria failed to undergo compensatory volume regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Z Lebensm Unters Forsch, 1995 Mar, 200(3), 203 - 8
{Detection of enzyme activity in decontaminated spices in industrial use}; Muller R et al.; A range of decontaminated species of industrial use have been examined for their enzymes (catalase, peroxidase, amylase, lipase activity) . The genuine enzymes remain fully active in irradiated spices, whereas the microbial load is clearly reduced . In contrast steam treated spices no longer demonstrate enzyme activities . Steam treatment offers e.g . black pepper without lipase activity, which can no longer cause fat deterioration . Low microbial load in combination with clearly detectable enzyme activity in spices is an indication for irradiation, whereas, reduced microbial contamination combined with enzyme inactivation indicate steam treatment of raw material.

Clin Exp Immunol, 1995 Mar, 99(3), 392 - 7
Recognition of a unique peptide epitope of the mycobacterial and human heat shock protein 65-60 antigen by T cells of patients with recurrent oral ulcers; Hasan A et al.; T cell epitopes of the 65-kD heat shock protein (hsp) were investigated in patients with recurrent oral ulcers (ROU) . Peripheral blood mononuclear cells were stimulated with overlapping synthetic peptide (15ers), derived from the sequence of the 65-kD hsp of Mycobacterium tuberculosis . Specific lymphoproliferative responses were stimulated only with peptide 91-105 in ROU, compared with healthy or disease controls (P < 0.01) . This was confirmed by studying 760 short term cell lines generated with the 65-kD hsp and then stimulated with the peptides . The frequency of short term cells lines responding to peptide 91-105 in ROU was significantly greater than in healthy (P < 0.0001) or disease controls (P < 0.01) . A comparative investigation with the homologous human 60-kD hsp peptide 116-130 also showed significantly greater lymphoproliferative responses in ROU than in healthy (P < 0.01) or disease controls (P < 0.001) . The potential involvement of the T cell epitope 91-105 in the pathogenesis of ROU is supported by finding a significant increase in the lymphoproliferative responses stimulated with peptide 91-105 during the stage of ulceration, compared with remission in 9/11 patients studied sequentially (P < 0.05) . The results suggest that oral ulceration might be initiated by the microbial hsp peptide 91-105 stimulating the mucosal Langerhans cells, which may generate autoreactive T cell clones primed to the homologous peptide 116-130.

Nature, 1995 Feb 23, 373(6516), 721 - 4
Sequence specificity and transcriptional activation in the binding of lactoferrin to DNA; He J et al.; Lactoferrin, an iron-binding glycoprotein found in high concentrations in human milk and other epithelial secretions and in the secondary (specific) granules of neutrophils, is thought to be responsible for primary defence against microbial infection, mainly as a result of lactoferrin sequestration of iron required for microbial growth . Many other functions have been attributed to lactoferrin, including immunomodulation and cell growth regulation (reviewed in ref . 4) . Some of these functions appear to be at least in part independent of the iron-binding activity of lactoferrin . It also has been consistently observed that lactoferrin interacts avidly with nucleic acids . Lactoferrin enhancement of the activity of natural killer and lymphokine-activated killer cells in vitro is inhibited by RNA and DNA . Lactoferrin taken up by K562 human myelogenous leukaemia cells appears in the nucleus where it is bound to DNA . We report here that binding of lactoferrin to DNA occurs under stringent conditions with distinct sequence specificity, and that interaction between lactoferrin and these sequences intracellularly leads to transcriptional activation.

J Steroid Biochem Mol Biol, 1995 Feb, 52(2), 203 - 8
Microbial transformation of steroids--IX . Purification of progesterone hydroxylase cytochrome P-450 from Phycomyces blakesleeanus; Ahmed F et al.; Progesterone hydroxylase cytochrome P-450 was purified to homogeneity from Phycomyces blakesleeanus microsomes by a four step procedure . An M(r) value of 60,000 was determined for this protein by SDS-PAGE . The DEAE-cellulose and Blue-1 MIMETIC affinity fractions gave major peaks at 452 nm in a dithionite-reduced, carbon monoxide, difference spectrum . NaIO4-dependent progesterone hydroxylation was obtained by the pure enzyme without NADPH and NADPH-cytochrome P-450 reductase . NADPH-dependent hydroxylation required the addition of other Phycomyces microsomal proteins present in the Blue-1 fraction.

J Clin Invest, 1995 Feb, 95(2), 571 - 6
Direct demonstration of increased expression of Thomsen-Friedenreich (TF) antigen in colonic adenocarcinoma and ulcerative colitis mucin and its concealment in normal mucin; Campbell BJ et al.; Increased binding of the lectin peanut agglutinin is a common feature in epithelial malignancy and hyperplasia . This may have considerable functional importance in the intestine by allowing interaction between the epithelium and mitogenic lectins of dietary or microbial origin . Peanut agglutinin binds the disaccharide Thomsen-Friedenreich (TF, T or core 1) blood group antigen, Gal beta (1-3) GalNAc alpha-, but is not totally specific for this site . Consequently, there has been controversy about the presence of this structure in colon cancer; studies with anti-TF monoclonal antibodies have failed to detect it . We have examined the presence of TF antigen in colonic mucus glycoprotein (mucin) using endo-alpha-N-acetylgalactosaminidase (O-Glycanase), which specifically catalyzes the hydrolysis of TF antigen from glycoconjugates . Samples of adenocarcinoma, inflammatory bowel disease (ulcerative colitis), and normal mucin were treated with O-glycanase, the liberated disaccharide was separated from the glycoprotein and analyzed using dual CarboPac PA-100 column high performance anion-exchange chromatography coupled with pulsed amperometric detection . O-Glycanase treatment released increased amounts of TF antigen from both colonic adenocarcinoma (8.0 +/- 3.9 ng/micrograms protein, n = 11; P < 0.0001 ANOVA) and ulcerative colitis mucin (3.3 +/- 0.3 ng/micrograms protein, n = 5; P = 0.04) compared with mucin samples from histologically normal mucosa distant from carcinoma (1.5 +/- 1.1 ng/micrograms protein, n = 9) . However, after mild acid treatment to remove sialic acids and fucose, releasable TF antigen was increased in all nine of these histologically normal mucin samples (5.5 +/- 2.6 ng/micrograms protein, P < 0.0002) . We conclude that TF antigen is an oncofetal antigen which is expressed in colon cancer, but is concealed by further glycosylation (sialylation and/or fucosylation) in the normal colonic mucosa.

Dig Dis Sci, 1995 Feb, 40(2 Suppl), 81S - 95S
Effects of acid suppression on microbial flora of upper gut; Yeomans ND et al.; Decreased acid secretion, due to therapy or disease, predisposes to increased bacterial counts in gastric juice . As bacterial numbers increase, the number of nitrate-reducing strains and the concentration of luminal nitrite usually also increase . However, there is controversy (mainly because of assay problems) about whether decreased acid increases generation of N-nitroso compounds: these may be produced by acid or by bacterial catalysis, and the relative contributions of each are still uncertain . Other potentially important factors include ascorbate secretion (can prevent nitrite conversion to nitroso compounds) and the particular spectrum of nitroso compounds produced . Nitrosation of several histamine H2-receptor antagonists has been demonstrated experimentally, but under conditions that are very unlikely to be encountered clinically . Some acid suppressant therapies have been claimed to aid eradication of Helicobacter pylori, but more work is needed to evaluate this . If ulcer treatment regimens do not also address eradication of H . pylori (when present), gastritis will progress, and the recently documented association between H . pylori and gastric carcinoma needs to be considered . Enteric flora probably also increase if acid secretion is markedly reduced: this does not appear to have nutritional consequences but probably reduces the resistance to occasional infections, of which cholera is the best documented.

Emerg Med Clin North Am, 1995 Feb, 13(1), 105 - 31
Noninfectious manifestations of human immunodeficiency virus infection; Galetto G et al.; Infection with HIV is associated with an array of noninfectious conditions of which the emergency physician should be aware . The knowledge of these complications and their differentiation from microbial conditions also common with HIV is essential in treating such patients in the emergency department . These complications involve every organ system: they are discussed in some detail and the most common are considered more closely from a target organ perspective.

Am J Respir Crit Care Med, 1995 Feb, 151(2 Pt 1), 475 - 81
Modulation of airway intraepithelial dendritic cells following exposure to steroids; Nelson DJ et al.; Recent studies from our laboratory have identified a network of constitutively class II major histocompatibility complex (MHC) (Ia)-bearing dendritic cells (DC) within the epithelium of the conducting airways of laboratory animal species and in humans . These studies have also demonstrated that the density of the DC network increases within the airway epithelium in response to inflammatory challenge . In the present report, we demonstrate that exposure of adult rats to inhaled steroids leads to a rapid but readily reversible decrease both in the number of airway intraepithelial DC, and in their surface Ia expression . Similar changes are also seen in response to high doses of systemic dexamethasone . In addition, we demonstrate that steroid inhalation reduces the rate of postnatal expansion of the airway intraepithelial DC network in rat pups, and prevents the rapid expansion of the DC network in adults which occurs during the acute inflammatory response following inhalation of microbial stimuli.

Int Arch Allergy Immunol, 1995 Feb, 106(2), 97 - 100
Cytokines and sleep; Krueger JM et al.; Infectious challenges induce sleep responses in the host characterized by an increase in non-rapid eye movement sleep (NREMS) followed by a period of decreased NREMS . Such sleep responses represent one facet of the acute phase response and are thus probably beneficial to the host . Certain bacterial cell wall products such as lipopolysaccharide and peptidoglycan and viral double-stranded RNA also induce sleep responses . These microbial products share the ability to enhance cytokine production . Some cytokines such as interleukin-1, tumor necrosis factor, interferon-alpha and acidic fibroblast growth factor are somnogenic . Cytokines in turn alter production of neuroendocrines and neurotransmitters, e.g., growth hormone releasing hormone and nitric oxide, which are known to be involved in sleep-wake regulation . Microbial-altered sleep thus likely involves an amplification of ongoing normal sleep regulatory mechanisms.

J Virol, 1995 Feb, 69(2), 1339 - 43
Intracellular neutralization of influenza virus by immunoglobulin A anti-hemagglutinin monoclonal antibodies; Mazanec MB et al.; Traditionally, immunoglobulin A (IgA) was thought to neutralize virus by forming complexes with viral attachment proteins, blocking attachment of virions to host epithelial cells . Recently we have proposed an intracellular action for dimeric IgA, which is actively transported through epithelial cells by the polymeric immunoglobulin receptor (pIgR), in that it may be able to bind to newly synthesized viral proteins within the cell, preventing viral assembly . To this effect, we have previously demonstrated that IgA monoclonal antibodies against Sendai virus, a parainfluenza virus, colocalize with the viral hemagglutinin-neuraminidase protein within infected epithelial cells and reduce intracellular viral titers . Here we determine whether IgA can interact with influenza virus hemagglutinin (HA) protein within epithelial cells . Polarized monolayers of Madin-Darby canine kidney epithelial cells expressing the pIgR were infected on their apical surfaces with influenza virus A/Puerto Rico/8-Mount Sinai . Polymeric IgA anti-HA, but not IgG anti-HA, delivered to the basolateral surface colocalized with HA protein within the cell by immunofluorescence . Compared with those of controls, viral titers were reduced in the supernatants and cell lysates from monolayers treated with anti-HA IgA but not with anti-HA IgG . Furthermore, the addition of anti-IgA antibodies to supernatants did not interfere with the neutralizing activity of IgA placed in the basal chamber, indicating that IgA was acting within the cell and not in the extracellular medium to interrupt viral replication . Thus, these studies provide additional support for the concept that IgA can inhibit replication of microbial pathogens intracellularly.

Immunol Cell Biol, 1995 Feb, 73(1), 23 - 32
Expression and immune recognition of stress proteins in sarcoidosis and other chronic interstitial lung diseases; Staton JM et al.; Stress proteins (SP) are major immunogens in a number of microbial infections and have been implicated in some autoimmune diseases . The aetiology of sarcoidosis, a non-caseating granulomatous disease, remains unknown, but mycobacteria as well as autoimmunity have been considered . In the present study, patients diagnosed with sarcoidosis and other interstitial lung diseases (ILD), as well as healthy volunteers were studied to determine: (i) the level of expression of SP in alveolar macrophages and blood monocytes; (ii) the serum levels of antibodies specific for mycobacterial SP65 and SP70; and (iii) the reactivity of peripheral blood and alveolar lymphocytes to mycobacterial SP65 . Our results suggest that SP are expressed constitutively at high levels in alveolar macrophages, retrieved by bronchoalveolar lavage, from all individuals regardless of health status . In contrast, freshly isolated blood monocytes express low levels of SP, which are, however, readily upregulated following exposure to IFN-gamma and TNF-alpha . Lymphocyte reactivity and presence of antibodies against mycobacterial SP may reflect the current state of in vivo inflammation rather than the cause of inflammation.

Biosci Biotechnol Biochem, 1995 Feb, 59(2), 319 - 20
Isolation of an antioxidant from Penicillium roquefortii IFO 5956; Hayashi K et al.; In the search for antioxidants from microbial organisms, we found that Penicillium roquefortii IFO 5956 produced an antioxidant . This antioxidant was isolated from a culture broth of the strain, and its structure was identified to be 2,3-dihydroxy benzoic acid (1) . The antioxidative activity of 1 was nearly equal to that of tert-butyl-4-hydroxyanisol (BHA).

J Am Vet Med Assoc, 1995 Feb 1, 206(3), 338 - 41
Amphotericin B treatment of Candida arthritis in two horses; Madison JB et al.; Infectious arthritis caused by Candida spp was diagnosed in 2 horses . Source of infection was by direct inoculation in 1 horse and was presumed to be hematogenous in the other horse . On microbial culturing of synovial fluid and synovial membrane specimens, the organisms were isolated in both horses . In both horses, the joint infections resolved after i.v . administration of amphotericin B and joint drainage; however, 1 horse was eventually euthanatized because of signs of cervical pain and progressively worsening ataxia . Fungal organisms isolated on microbial culturing of joint specimens in horses, although uncommon, should not be dismissed as contaminants, particularly if the same organism is recovered from more than 1 specimen . Successful resolution of fungal arthritis may be achieved with appropriate antifungal treatment, combined with joint drainage.

J Dent Res, 1995 Feb, 74(2), 686 - 90
Association of free arginine and lysine concentrations in human parotid saliva with caries experience; Van Wuyckhuyse BC et al.; We determined the free-amino acid content of stimulated parotid (ductal) saliva from two groups of adult subjects whose caries experiences were markedly different . The levels of free arginine and free lysine in the parotid saliva of caries-free adults were significantly higher than those found in the parotid saliva of individuals with a history of dental decay . There was no correlation, however, between the levels of these amino acids and the DMFS score within the caries-susceptible groups . Microbial catabolism of dibasic amino acids contributes to the neutralization of plaque acids and may partially account for the higher resting plaque pH observed in caries-free subjects . Alternatively, the elevations observed in free levels of arginine and lysine may reflect a systemic alteration in amino acid metabolism which is common to the caries-free group of subjects.

Cell Immunol, 1995 Feb, 160(2), 264 - 9
Upregulation of interferon-induced indoleamine 2,3-dioxygenase in human macrophage cultures by lipopolysaccharide, muramyl tripeptide, and interleukin-1; Hissong BD et al.; The tryptophan decyclizing enzyme indoleamine 2,3-dioxygenase (IDO) was induced in human monocyte-derived macrophages (MDM) treated with human recombinant interferon-beta (IFN-beta) or interferon-gamma (IFN-gamma) . Treated cells exhibited dose-dependent increases in IDO when assayed 48 hr after treatment . Cells exposed to IFN-gamma were observed to exhibit consistently higher peak levels of IDO when compared with cells incubated in the presence of IFN-beta . When IFN-beta-treated cells were incubated in the presence of specified amounts of bacterial lipopolysaccharide (LPS) or liposome-encapsulated muramyl tripeptide (MTP), peak IDO activity increased such that enzyme activity was comparable to maximal activity observed with IFN-gamma-treated cells . LPS and MTP also upregulated IFN-gamma-mediated IDO activity when suboptimal amounts of IFN-gamma were used . When macrophages were costimulated with various concentrations of human recombinant interleukin 1 alpha (IL-1 alpha), along with either maximum-stimulating amounts of IFN-beta or suboptimal amounts of IFN-gamma, IDO activity was upregulated in a manner similar to results obtained using the microbial products as stimuli . While neither IL-1 alpha or IL-1 beta was detected in culture supernatants from macrophages treated with either LPS or MTP (alone or in combination with IFN), IL-1 alpha was detected in cell lysates of macrophages treated with these upregulators . Although neutralizing antibody to IL-1 alpha abolished the upregulatory effect of exogenous IL-1 alpha, it had no effect on upregulation by LPS or MTP . This suggests that although LPS and MTP may induce production of cell-associated IL-1 alpha, upregulation of IDO activity by these agents is independent of IL-1 alpha production and may be mediated through distinct pathways.

Mol Ecol, 1995 Feb, 4(1), 17 - 28
Molecular genetic analysis of the response of three soil microbial communities to the application of 2,4-D; Xia X et al.; The responses of three different soil microbial communities to the experimental application of 2,4-dichlorophenoxyacetic acid (2,4-D) were evaluated with a variety of molecular genetic techniques . Two of the three soil communities had histories of prior direct exposure to 2,4-D, and one had no prior direct application of any herbicide . Dominant 2,4-D degrading strains isolated from these soils the previous year were screened for hybridization with three catabolic genes (tfdA, tfdAII, and tfdB) cloned from the well-studied 2,4-D degradative plasmid, pJP4, revealing varying degrees of similarity with the three genes . Hybridization of total community DNA from the three soils with the tfd gene probes also indicated that pJP4-like tfd genes were not harboured by a significant percentage of the community . Community level response was evaluated by the comparison of different treatments by Random Amplified Polymorphic DNA (RAPD) fingerprints and by community DNA cross-hybridization . No differences between treatments within the same soil were detected in any of the RAPD fingerprints generated with 17 primers . Community DNA cross-hybridization also indicated that the application of 2,4-D at the applied rates did not quantitatively affect the structure of the soil microbial communities present in the three soils during the time-frame studied.

J Am Coll Nutr, 1995 Feb, 14(1), 18 - 23
Omega-3 fatty acids in respiratory diseases: a review; Knapp HR; The health benefits of dietary omega-3 fatty acids have been investigated in a variety of conditions but there have been few studies of their effects in human respiratory diseases . Although many of the physiological changes associated with omega-3 polyunsaturate ingestion have been attributed to alterations in endogenous eicosanoid production, effects on blood rheology, host-microbial interactions and lung surfactant production have also been described . In reviewing the literature, there is little evidence that these polyunsaturates have beneficial effects in allergic disorders, but they may have potential as modulators of respiratory diseases involving chronic inflammatory and infectious processes or impaired pulmonary blood flow . Further work on the effects of omega-3 fatty acids in several chronic pulmonary syndromes, for which there are currently no effective therapies, appears to be warranted.

Appl Environ Microbiol, 1995 Feb, 61(2), 784 - 7
Polyclonal antibodies to chlorosome proteins as probes for green sulfur bacteria; Cahill AD et al.; We found that polyclonal antibodies raised against chlorosome polypeptides from green sulfur bacteria reacted to Chlorobium tepidum, Chlorobium limicola, and Chlorobium phaeobacteroides but not to Chloroflexus aurantiacus . These antibodies successfully labeled only green sulfur species in marine microbial mat samples . Our results suggest that these antibodies may be useful as immunohistochemical probes.

Appl Environ Microbiol, 1995 Feb, 61(2), 763 - 8
Isolation and characterization of RNA from low-biomass deep-subsurface sediments; Ogram A et al.; Three methods for the isolation of microbial RNA from low-biomass deep-subsurface sediments have been developed and evaluated . RNA was isolated from samples taken from depths ranging from 173 to 217 m, and samples represented a variety of lithologies, including lacustrine, fluvial sand, and paleosol sediments . Cell numbers in these samples were estimated to be between log 4.0 and log 5.1/g on the basis of phospholipid fatty acid analysis . The most efficient method examined is based on the direct lysis of microbial cells followed by the extraction of RNA with alkaline phosphate buffers and subsequent inactivation of nucleases by extraction with guanidinium isothiocyanate . Estimated recoveries of mRNA for this method are approximately 26% . The recovered RNA included both mRNA and rRNA, as evidenced by the detection of sequences homologous to transcripts from the toluene-4-monooxygenase gene of Pseudomonas mendocina KR1 and bacterial, archaeal, and eukaryotic rRNA . An unexpectedly high relative concentration of archaeal rRNA (22 to 40%) was observed for these samples.

J Immunol, 1995 Feb 1, 154(3), 998 - 1006
V gamma 2V delta 2 TCR-dependent recognition of non-peptide antigens and Daudi cells analyzed by TCR gene transfer; Bukowski JF et al.; The predominant subpopulation of gamma delta T cells in human peripheral blood expresses TCR V region genes V gamma 2 paired with V delta 2 . Previous studies have shown that these V gamma 2V delta 2+ T cells proliferate in response to Daudi Burkitt lymphoma cells, synthetic alkyl phosphate molecules including monoethylphosphate (MEP), and an Ag chemically similar to MEP purified from mycobacterial extracts of several species including Mycobacterium tuberculosis . This proliferation is polyclonal and determined by the TCR V gene . However, because these alkyl phosphate molecules are so distinct from conventional peptides and superantigens, we questioned whether these substances induce gamma delta T cell proliferation via TCR-dependent recognition . Here we report that transfection of TCR- Jurkat T cells with cDNA constructs encoding a V gamma 2V delta 2 TCR enabled the transfectants to produce IL-2 in response to Daudi cells, mycobacterial extract, and MEP . The responses were dose dependent and Ag specific . These results demonstrate an essential role for the gamma delta TCR in V gamma 2V delta 2 T cell-mediated recognition of non-peptide Ags by human T cells and suggest a structural similarity or cross-reactivity between cellular and microbial Ags recognized by these gamma delta T cells.

Biochim Biophys Acta, 1995 Jan 18, 1243(1), 124 - 8
A sheep hydatid cyst glycoprotein as receptors for three toxic lectins, as well as Abrus precatorius and Ricinus communis agglutinins; Wu AM et al.; The binding properties of a glycoprotein with blood group P1 specificity isolated from sheep hydatid cyst fluid with Gal and GalNAc specific lectins was investigated by quantitative precipitin and precipitin inhibition assays . The glycoprotein completely precipitated Ricinus communis agglutinin (RCA1), Abrus precatorius agglutinin (APA) and Mistletoe toxic lectin-I (ML-I) . Only 1.0 microgram of P1 glycoprotein was required to precipitate 50% of 5.1 micrograms ML-I nitrogen . It also reacted well with abrin-a and ricin, precipitating over 73% of the lectin nitrogen added, but poorly or weakly with Dolichos biflorus (DBL), Vicia villosa (VVL, a mixture of A4, A2B2 and B4), VVL-B4, Arachis hypogaea (PNA), Maclura pomifera (MPL), Bauchinia purpurea alba (BPL) and Wistaria floribunda (WFL) lectins . When an inhibition assay in the range of 5.1 micrograms N to 5.9 micrograms N of lectins (ML-I, abrin-a; ricin, RCA1, and APA, and 10 micrograms P1 active glycoprotein interaction was performed; from 76 to 100% of the precipitations were inhibited by 0.44 and 0.52 mumol of Gal alpha 1-->4Gal and Gal beta 1-->4GlcNAc, respectively, but not or insignificantly with 1.72 mumol of GlcNAc . The Gal alpha 1-->4Gal disaccharide found in this P1 active glycoprotein is a frequently occurring sequence of many glycosphingolipids located at the surface of mammalian cell membranes, especially human erythrocytes and intestinal cells for ligand binding and microbial toxin attachment . The present finding suggests that the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in this P1 active glycoprotein is one of the best glycoprotein receptors for three toxic lectins (ricin, abrin-a, and ML-I) as well as for APA, and RCA1, and the result of inhibition assay implies that these lectins are recognizing part or all of the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in the P1 active glycoprotein.

Eur J Biochem, 1995 Jan 15, 227(1-2), 335 - 43
Stereoselectivity of microbial lipases . The substitution at position sn-2 of triacylglycerol analogs influences the stereoselectivity of different microbial lipases; Stadler P et al.; In the present study, the stereoselectivity of purified lipases from Candida rugosa, Chromobacterium viscosum, Pseudomonas species and Rhizopus arrhizus towards triacylglycerols in comparison to various structural analogs were investigated . Different triacylglycerol analogs with distinct polarities at position sn-2 of the glycerol backbone (1,3-diacyl-2-X-glycerol, where 2-X = 2-acyloxy, 2-alkyloxy, 2-deoxy-2-alkyl, or 2-deoxy-2-phenyl) were synthesized . Substrate hydrophobicity and steric requirement was modified by variation of the alkyl and acyl chain length . Hydrolysis of these substrates demonstrated that minor structural variations at C2 of triacylglycerol strongly affect the stereoselectivity of the lipases tested . It was noteworthy that the variation of substrate structure did not only affect the quantity of stereoselectivity expressed as percentage enantiomeric excess, but also resulted in a reversal of stereopreference in some cases . Replacement of the acylester in position 2 of glycerol by a non-ester-linked aliphatic moiety shifted the preference of Chromobacterium viscosum lipase from sn-3 to sn-1 . Lipases from Chromobacterium viscosum . Pseudomonas species and Rhizopus arrhizus exhibited sn-3 preference with 2-deoxy-2-phenyl analogs, while towards substrates with a 2-deoxy-2-alkyl moiety sn-1 stereobias was recorded . Candida rugosa lipase was rather insensitive to substrate variations concerning the polarity at position 2 of the glycerol backbone . However, variation of the acyl chain length significantly influenced stereoselectivity of this lipase.

Sci Total Environ, 1995 Jan 15, 160-161, 65 - 74
Air-water gas exchange and evidence for metabolism of hexachlorocyclohexanes in Resolute Bay, N.W.T; Falconer RL et al.; Paired air and water samples were collected at Resolute Bay (74 degrees N, 95 degrees W) in summer 1992 to estimate the direction of gas exchange of hexachlorocyclohexanes (HCHs) and investigate possible loss processes in the water column . Average concentrations of alpha-HCH and gamma-HCH in ocean surface water were 4.7 +/- 0.9 and 0.44 +/- 0.11 ng/l, respectively . These alpha- and gamma-HCH levels are approximately 66-104% and 54-72% of values reported for the central Arctic Ocean at the Canadian Ice Island in 1986 . Mean atmospheric concentrations of alpha-HCH and gamma-HCH (114 +/- 16 and 9.8 +/- 1.3 pg/m3) were 2-3 times lower than summer Arctic levels in the 1980s . The ocean surface water (-1.4 degrees C) was approximately within Henry's Law equilibrium with respect to atmospheric gamma-HCH levels . Water/air fugacity ratios were 1.03 for gamma-HCH and 1.57 for alpha-HCH, indicating a slight potential for volatilization of alpha-HCH . The two alpha-HCH enantiomers in air and water were separated by chromatography on a gamma-cyclodextrin capillary column . The enantiomeric ratio (ER = ratio of (+)alpha-HCH/(-)alpha-HCH) in air was 1.00 +/- 0.04 . This agrees excellently with ER = 1.00 +/- 0.01 found for a racemic alpha-HCH standard . The (+) enantiomer was depleted in seawater, resulting in ER = 0.93 +/- 0.06 in Resolute Bay . ERs of samples from Amituk Lake on Cornwallis Island ranged from 0.65 to 0.99, depending on location, date and relative contributions of fresh snowmelt and older lake water . These results suggest that microbial degradation of HCHs is taking place in Arctic lakes and near-shore marine waters.

Lancet, 1995 Jan 14, 345(8942), 79 - 83
Familial disseminated atypical mycobacterial infection in childhood: a human mycobacterial susceptibility gene?
Levin M, Newport MJ, D'Souza S, Kalabalikis P, Brown IN, Lenicker HM, Agius PV, Davies EG, Thrasher A, Klein N, et al.
Inherited defects in specific components of the immune system have provided many clues to the immunological mechanisms underlying resistance to microbial infection . We report a familial immune defect predisposing to disseminated atypical mycobacterial infection in childhood . 6 children with disseminated atypical mycobacterial infection and no recognised form of immunodeficency were identified . Four, including two brothers, come from a village in Malta, and two are brothers of Greek Cypriot origin . They presented with fever, weight loss, lymphadenopathy, and hepatosplenomegaly . They had anaemia and an acute phase response . A range of different mycobacteria (Mycobacterium fortuitum, M chelonei, and four strains of M avium intracellulare complex) were isolated . Treatment with multiple antibiotics failed to eradicate the infection, although treatment with gamma interferon was associated with improvement . Three have died and the surviving children have chronic infection . Tumour necrosis factor-alpha production in response to endotoxin and gamma-interferon was found to be defective in affected patients and their parents . T-cell proliferative responses to mycobacterial and recall antigens were reduced in parents of affected children and gamma-interferon production was diminished in the affected patients and their parents . Clinical and immunological features suggest that these patients are phenotypically similar to Lsh/Ity/Bcg susceptible mice . Understanding of this defect may provide insights into the mechanisms responsible for susceptibility to mycobacteria.

Presse Med, 1995 Jan 14, 24(2), 119 - 20, 123-8
{Whipple disease: a single or multiple origin?}; Cerf M et al.; After having been considered as an essentially digestive disease, Whipple's disease has appeared more and more to be a multivisceral disease with two main characteristics: on one hand Whipple's disease yields a diffuse infiltration of tissues by abnormal macrophages without any other inflammatory reaction; on the other hand, aspects of microbial invasion by intra or extracellular unique rod-shaped Gram+bacteria are found . This unusual pathological complex has alternatively been considered as suggestive of an immunological defect or as a very unusual type of bacterial infection . Though recent studies support the hypothesis of a primary microbial infection due to a hitherto undescribed bacterium (Tropheryma whippelii) or more or less related bacteria belonging to the actinomycetes family, they do not totally exclude a primary or acquired impairment of antigen processing by macrophages . Speculations about this fascinating pathophysiological model and about its optimal therapeutic modalities are not likely to reach a conclusion in the near future.

J Chromatogr B Biomed Appl, 1995 Jan 6, 663(1), 127 - 35
Solid-phase clean-up and thin-layer chromatographic detection of veterinary aminoglycosides; Medina MB et al.; Chemical methods are needed to confirm the presence of antibiotics detected by microbial inhibition assays in fluids and tissues of farm animals . We have optimized the conditions for the isolation of hygromycin B with a copolymeric bonded solid-phase silica column followed by thin-layer chromatography (TLC) separation and detection of its fluorescence derivative after reaction with fluorescamine . The detection limit of the drug was 50 ng . Serum and plasma samples fortified with hygromycin B were acidified and passed through the copolymerized solid-phase columns previously conditioned with phosphate buffer . Hygromycin B was trapped in the columns and eluted with diethylamine-methanol and analyzed by TLC using acetone-ethanol-ammonium hydroxide as the developing solvent . Hygromycin B bands were derivatized at acidic pH with fluorescamine and visualized under ultraviolet light . Hygromycin B added to bovine plasma was detectable at 25, 50, 100, 250 and 500 ng/ml (ppb) . Hygromycin B added to swine serum was detected at 50 ng/ml . However, the serum had to be deproteinized with trichloroacetic acid or acetonitrile prior to solid-phase extraction to gain accurate values . Neomycin and gentamicin (100 ng/ml aqueous solutions) could also be isolated with copolymeric solid-phase columns at a level of 50 ng . Gentamicin, neomycin, gentamicin, spectinomycin, hygromycin B and streptomycin could be separated by TLC, allowing multiresidue detection of these aminoglycosides . The respective RF values of 0.64, 0.56, 0.52, 0.33 and 0.20 indicate the separation of these five compounds . This procedure provides a rapid and sensitive method for the semi-quantitative estimation of aminoglycosides.

Biol Res, 1995, 28(4), 239 - 49
Plant proteinase inhibitors: a defensive response against insects . (Review); Casaretto JA et al.; Plants protect themselves against pests using their wide chemical defense arsenal . Among several defense proteins, proteinase inhibitors appear to be an important group . Proteinase inhibitors are widely present in plants and they are often found in storage organs . They are known to be inducible in plants by injuries, such as insect damage . Because these proteins inhibit digestive enzymes of insect larvae and microbial proteases, they may be considered as mechanisms to improve the plant defense against pests . In recent years, growing research on plant proteinase inhibitors has confirmed their important role in plant defense, although several aspects are still controversial . Although many plants have related proteinase inhibitors, which have been shown to affect metabolism and/or development of different insects, these plants do not seem to share a common inhibitor induction mechanism . This is an emerging field and much work is yet to be done.

Biofactors, 1995-96, 5(3), 139 - 46
Synthesis of esters of coenzyme PQQ and IPQ, and stimulation of nerve growth factor production; Urakami T et al.; Esters of pyrroloquinoline quinone (PQQ), a cofactor of microbial quinoprotein enzyme, and imidazopyrroloquinoline (IPQ, from PQQ and glycine) were synthesized, and their chemical stability, toxicity to L-M cells and nerve growth factor (NGF) inducing activity in L-M cells were studied . PQQ esters were found to be potent enhancers of NGF production, but IPQ esters had only marginal effects on NGF production . The monoester of PQQ with a methoxycarbonyl group at C-2 of PQQ is a most effective compound because of its NGF inducing activity, limited toxicity, safety and chemical stability . These results suggest that PQQ-2-esters could be developed as a curative or preventive drug for retrograde neural diseases in the central and perpheral nervous system.

Emerg Infect Dis, 1995 Jan-Mar, 1(1), 1 - 6
Emerging infections: getting ahead of the curve; Satcher D; The early history of infectious diseases was characterized by sudden, unpredictable outbreaks, frequently of epidemic proportion . Scientific advances in the late 19th and early 20th centuries resulted in the prevention and control of many infectious diseases, particularly in industrialized nations . Despite these improvements in health, outbreaks of infectious disease continue to occur, and new infections emerge . Since 1987, the National Academy of Science's Institute of Medicine (IOM) has published three reports that have identified erosion of the public health infrastructure among the factors contributing to new and reemerging infectious diseases . In partnership with many public and private organizations in the United States and abroad, the Centers for Disease Control and Prevention (CDC) has developed a strategic plan that addresses the priorities set forth in the IOM reports and serves as a guide for CDC and its partners to combat emerging microbial threats to health . Laboratory-based surveillance, better communication networks, and improvements in the public health infrastructure are the cornerstones of the strategy . Emerging Infectious Diseases, a new periodical produced by CDC, will serve as a forum for exchange of information about incipient trends in infectious diseases, analysis of factors contributing to disease emergence, and development and implementation of prevention measures.

Folia Microbiol (Praha), 1995, 40(1), 4 - 16
Some developments in the biosynthesis of antibiotics; Thomas R; In Prague in 1964, the participants in the International Congress on Antibiotics collectively presented an authoritative account of the existing understanding of the mechanism of biosynthesis of many of the major groups of antibiotics and other microbial metabolites . This information was derived to a large extent from applications of the then comparatively novel radioisotopic technique for studying the mode incorporation of labelled precursors . The intervening 30 years has witnessed remarkable progress in techniques for manipulating microbial genes and enzymes, while at the chemical level, advances in spectroscopic and chromatographic procedures have facilitated the use of stable isotopes as direct probes for the small scale exploration of metabolic pathways . As a consequence, our understanding of many mechanistic details has been considerably enhanced . Some of the developments to date will be reviewed, with particular reference to the elaboration of biosynthetic pathways leading to many of the antibiotics and other natural products described at the earlier Prague symposium.

Rev Belge Med Dent, 1995, 50(4), 9 - 27
{Treatment planning . Learning to solve complicated dental problems}; Verdonschot EH; The importance of comprehensive care treatment planning in dental undergraduate and graduate curricula has long been underestimated . With a decreasing prevalence of dental diseases an increasing interest in the subject has been recognized . Comprehensive care treatment planning requires a strategic approach to resolve a patient's problems in a logical sequence and at a a priori estimation of treatment time and costs . The strategy outlined in this work comprises a phasing of the treatment along urgency criteria . Initially, immediate problems are resolved, followed by microbial problems, functional problems, after which a maintenance plan is established . A treatment planning model is introduced to enable students to hold track of the overall treatment plan and to advice students how to address specific dental problems.

Essays Biochem, 1995, 30, 59 - 75
Lectins--proteins with a sweet tooth: functions in cell recognition; Sharon N et al.; Lectins, non-enzymic proteins that bind mono- and oligosaccharides reversibly and with high specificity, occur widely in nature . They come in a variety of sizes and shapes, but can be grouped in families with similar structural features . The combining sites of lectins are also diverse, although they are similar in the same family . The specificities of lectins are determined by the exact shape of the binding sites and the nature of the amino acid residues to which the carbohydrate is linked . Small changes in the structure of the sites, such as the substitution of only one or two amino acids, may result in marked changes in specificity . The carbohydrate is linked to the protein mainly through hydrogen bonds, with added contributions from van der Waals contacts and hydrophobic interactions . Coordination with metal ions may occasionally play a role too . Microbial surface lectins serve as a means of adhesion to host cells of viruses (e.g . influenza virus), bacteria (e.g . E . coli) and protozoa (e.g . amoeba): a prerequisite for the initiation of infection . Blocking the adhesion by carbohydrates that mimic those to which the lectins bind prevents infection by these organisms . The way is thus open for the development of anti-adhesive therapy against microbial diseases . Lectin-carbohydrate mediated interactions between leucocytes and endothelial cells are the first step in the recirculation of lymphocytes and in the migration of neutrophils to sites of inflammation . Such interactions may also feature highly in the formation of metastases . Studies of these processes are expected to lead to the development of carbohydrate-based anti-adhesion drugs for the treatment of inflammatory diseases as well as cancer.

Biochimie, 1995, 77(9), 751 - 60
Do de-N-glycosylation enzymes have an important role in plant cells?
Berger S, Menudier A, Julien R, Karamanos Y.
In this review de-N-glycosylation was defined as the removal of the glycan(s) from a N-glycosylprotein, by means of enzymes acting on the di-N-acetylchitobiosyl part of the invariant pentasaccharide inner-core of N-glycosylproteins . Peptide-N4-(N-acetyl-beta-D-glucosaminyl) asparagine amidases (PNGase) and endo-N-acetyl-beta-D-glucosaminidases (ENGase) were both considered as de-N-glycosylation enzymes . A detailed description of the characterization and the function of plant PNGases and ENGases is presented, together with a brief presentation on the occurrence and the current knowledge on the function of microbial and animal enzymes . De-N-glycosylation of plant glycoproteins was proposed as a possible mechanism for the release of oligosaccharides displaying biological activities and the removal of N-glycans could also explain the regulation of protein activity . Each enzyme seems to have a specific function during germination and post-germinative development . All the arguments concur that de-N-glycosylation enzymes have an important role in plant cells and confirm that the N-glycosylation/de-N-glycosylation system should occur more commonly than presently recognized in living organisms.

Folia Microbiol (Praha), 1995, 40(4), 385 - 91
The gut as a lymphoepithelial organ: the role of intestinal epithelial cells in mucosal immunity; Tlaskalova-Hogenova H et al.; Mucosal surfaces covered by a layer of epithelial cells represent the largest and most critical interface between the organism and its environment . The barrier function of mucosal surfaces is performed by the epithelial layer and immune cells present in the mucosal compartment . As recently found, epithelial cells, apart from their participation in absorptive, digestive and secretory processes perform more than a passive barrier function and are directly involved in immune processes . Besides the well known role of epithelial cells in the transfer of polymeric immunoglobulins produced by lamina propria B lymphocytes to the luminal content of mucosals (secretory Igs), these cells were found to perform various other immunological functions, to interact with other cells of the immune system and to induce an efficient inflammatory response to microbial invasion: enzymic processing of dietary antigens, expression of class I and II MHC antigens, presentation of antigens to lymphocytes, expression of adhesive molecules mediating interaction with intraepithelial lymphocytes and components of extracellular matrix, production of cytokines and probable participation in extrathymic T cell development of intraepithelial lymphocytes . All these functions were suggested to influence substantially the mucosal immune system and its response . Under immunopathological conditions, e.g . during infections and inflammatory bowel and celiac diseases, both epithelial cells and intraepithelial lymphocytes participate substantially in inflammatory reactions . Moreover, enterocytes could become a target of mucosal immune factors . Mucosal immunosurveillance function is of crucial importance in various pathological conditions but especially in the case of the most frequent malignity occurring in the intestinal compartment, i.e . colorectal carcinoma . Proper understanding of the differentiation processes and functions of epithelial cells in interaction with other components of the mucosal immune system is therefore highly desirable.

C R Seances Soc Biol Fil, 1995, 189(6), 1081 - 96
{NO, ambivalent effector of non-specific immunity and of inflammation}; Drapier JC; Nitric oxide produced from the amino acid L-arginine is a short-lived free radical produced by many types of cells for a variety of biological functions, including defence against a range of pathogens . NO synthesis via NOS-2 is deeply intertwined in the cytokine network . Thus, expression of NOS-2 is induced by IFN-gamma, TNF and IL-1 as well as microbial products whereas IL-4, IL-10 and TGF-beta down-regulate its synthesis . In spite of this tight regulation, excessive production of NO as a result of immunological stimulation via NOS-2 could have potential toxic effects on hosts . Indeed, large amount of nitric oxide (NO) are produced at sites of inflammation through the action of NOS-2 . The role of NO in inflammation is unclear and may depend on the balance between NO and O2- . The somewhat paradoxical effects of NO might indeed be explained by its various chemical forms . Besides, understanding the regulation and function of NOS-2 is likely to lead to therapeutic approaches to treat a number of diseases.

Ann Nutr Metab, 1995, 39(6), 361 - 70
Effect of phytic acid and microbial phytase on Cd accumulation, Zn status, and apparent absorption of Ca, P, Mg, Fe, Zn, Cu, and Mn in growing rats; Rimbach G et al.; Three groups of individually housed albino rats (n = 6, initial average weight = 47 g) were fed diets based on egg white and cornstarch (basal diet 8 g Ca, 5.2 g P, 0.76 g Mg, 100 mg Zn, 100 mg Fe, 50 mg Mn, 7 mg Cu, and 5 mg Cd per kilogram diet) over a 4-week period . Group I (controls) was fed the basal diet free of phytic acid (PA) and microbial phytase . In groups II and III cornstarch was replaced by 0.5% PA from NaPA (molar PA/Zn ratio approximately 5) . In group III, 2,000 U of microbial phytase from Aspergillus niger per kilogram diet was added . Live weight gain, zinc status (zinc in plasma, femur, liver, and testes; activity of the plasma alkaline phosphatase), and apparent absorption of zinc, iron, copper, and manganese remained unchanged by the different dietary treatments . The apparent phosphorus absorption was highest in the phytase group . PA decreased and microbial phytase improved the apparent absorption of calcium and magnesium . Liver cadmium concentration, total liver and kidney cadmium content, as well as fractional liver and kidney cadmium accumulation in rats fed the diet containing PA were significantly higher than those in the controls . Phytase supplementation lowered liver and kidney cadmium accumulation . Differences in calcium and magnesium bioavailability due to PA and microbial phytase may be one factor in the alteration of tissue cadmium accumulation.

Aviakosm Ekolog Med, 1995, 29(5), 51 - 5
{Current problems of microbial safety of the interior environment of orbital stations after extended period of operation}; Viktorov AN et al.; The authors give considerations to one of the core hygienic problems arising in the process of long-term operation of orbital stations, i.e . ensuring microbial health of the milieu interior . Data pertaining the origin, interactions, and transformation of the microbial risk factors are analyzed as applied to this class of spacecraft . A concept of microbial health of the milieu interior including both medical and technological aspects relating to the reliability of space hardware is proposed . Based on the result of investigations in space flight, the developed criteria and indices of microbial health can be turned to practical use . The currently central tasks to be solved within the context of the problem and in view of the construction of international space station ALPHA are listed.

Biochem Soc Symp, 1995, 61, 247 - 58
Free radicals and food irradiation; Dodd NJ; Ionizing radiation can be used to control insect and microbial infestation of foodstuffs, inhibit sprouting, delay ripening and reduce the dangers from food-poisoning bacteria . Irradiation produces free radicals, most of which decay rapidly, although some are more persistent . These latter radicals can be detected and characterized by electron spin resonance (ESR) . In bone and other calcified tissues, the radiation-induced radicals are distinguishable from naturally occurring radicals, and their stability makes them ideal for radiation dosimetry . The radicals induced in plant material, such as seeds and dried spices, are generally indistinguishable from the endogenous radicals and decay over a period of days or weeks . However, in many of these materials, a radiation-specific radical can be detected at low concentration, thereby permitting identification of irradiated samples, although precluding accurate dosimetry . ESR, although not universally applicable, currently provides the most specific method for the detection of irradiated food.

Acta Med Croatica, 1995, 49(4-5), 177 - 80
Antibody-dependent cellular cytotoxicity, ingestion and digestion in Dermatophagoides pteronyssinus-sensitive asthmatic children; Baric I et al.; Dermatophagoides pteronyssinus (DP) is, for unknown reasons, the commonest cause of asthma attacks in children suffering from reaginic bronchial asthma . The underlying immune disorder is also unclear . The authors analyzed phagocytosis (ingestion), digestion and antibody-dependent cellular cytotoxicity (ADCC) of peripheral blood leukocytes in 20 asthmatic children hypersensitive to DP, aged 2 to 14 years . The tests were performed while the children were entirely asymptomatic and under no therapy . The aim was to determine the possible difference in comparison to healthy children and to assess the correlation of these results with the total serum IgE level, DP-specific IgE and duration of the disease . Ingestion in asthmatics did not differ significantly from that in controls, while digestion and ADCC were significantly (P < 0.01) lower in asthmatics . This phenomenon could contribute to their difficulties in the elimination of allergens, immune complexes and microbial, particularly viral antigens, making them more susceptible to allergic reaction and infections . No significant correlation to the total serum IgE level, DP-specific IgE and duration of the disease was found.

Rev Environ Contam Toxicol, 1995, 144, 95 - 146
Fate and effects of acrolein; Ghilarducci DP et al.; Acrolein is a highly toxic, reactive, and irritating aldehyde that occurs as a product of organic pyrolysis, as a metabolite of a number of compounds, and as a residue in water when used for the control of aquatic organisms . It is an intermediate in the production of acrylic acid, DL-methionine, and numerous other agents . Its major direct use is as a biocide for the control of aquatic flora and fauna . It is introduced to the environment from a variety of sources, including organic combustion such as automobile exhaust, cigarette smoke, and manufacturing and cooking emissions, as well as direct biocidal applications . Organic combustion from both fixed and mobile sources is the significant source of acrolein in the atmosphere; it represents up to 8% of the total aldehydes generated from vehicles and residential fireplaces and 13% of total atmospheric aldehydes . This reactive aldehyde also occurs in organisms as a metabolite of allyl alcohol, allylamine, spermine, spermidine, and the anticancer drug cyclophosphamide, and as a product of UV radiation of the skin lipid triolein . Furthermore, small amounts are found in foods; when animal or vegetable fats are overheated, however, large amounts are produced . Most human contact occurs during exposure to smoke from cigarettes, automobiles, industrial processes, and structural and vegetation fires . Besides cigarette smoke, occupational exposures are a common mode of human contact, particularly in industries that involve combustion of organic compounds . Firefighters, in particular, are exposed to extremely high levels during the extinguishment and overhaul phases of their work . Water may contain significant levels of the herbicide . It has been found in paper mill and municipal effluents at 20-200 micrograms/L, and at 30 micrograms/L as far as 64 km downstream from the point of application . The USEPA-recommended water quality criteria for freshwater are only 1.2 micrograms/L (24-hr avg) and 2.7 micrograms/L (maximum ceiling) . Acrolein is highly reactive, and intercompartmental transport is limited . However, it is eliminated from aqueous environments by volatilization and hydration to beta-hydroxypropanal, after which biotransformation occurs, with a half-life of 7-10 d . The Koc for acrolein is 24, and it is not likely to be retained in soil; activated carbon adsorbs only 30% from solution . Thus, the aldehyde is either leached extensively in moist soil or volatilizes quickly from dry soil . It is eliminated from air by reaction with .OH (half-life, 0.5-1.2 d), NOx (half-life, 16 d), and O3 (half-life, 59 d), as well as by photolysis and wet deposition . As expected from its high water solubility, bioaccumulation is low . Acrolein is highly toxic by all routes of exposure . The respiratory system is the most common target: exposure causes localized irritation, respiratory distress, pulmonary edema, cellular necrosis, and increased susceptibility to microbial diseases . Additionally, acute inhalation studies verify that it is a severe respiratory irritant that affects respiratory rates . Respiratory rate depression may have a protective effect by minimizing vapor inhalation, thereby explaining the subadditive effect of acrolein when combined with the other toxic combustion by-products CO and HCHO . Liquid contact with the skin and eyes causes severe irritation, opaque or cloudy corneas, and localized epidermal necrosis, but no allergic contact dermatitis . The cardiovascular system is affected, resulting in increased blood pressure, platelet aggregation, and quick cessation of beating in perfused rat hearts . It may also inhibit mitochondrial oxidative phosphorylation in the myocardium . Acute LD50s and LC50s are low . Levels are 7-46 mg/kg and 18-750 mg/m3, respectively, in rats; aquatic organisms are affected above 11.4 micrograms/L.(ABSTRACT TRUNCATED)

Medinfo . 1995;8 Pt 1:331.
Recurrent infections in children observed throughout electronic medical record; Bolens M et al.; This paper shows the usefulness of routinely collected structured clinical findings in an computerized patient record . Medical observations are collected as detailed clinical findings, without any interpretation, according to a time structure, visit by visit . In the present example, the role of the microbial colonization is studied in relationship with infected organs and other processes which could facilitate the infection.

Arch Tierernahr, 1995, 48(4), 347 - 55
Age dependent variation of caecal contents composition of young rabbits; Piattoni F et al.; In order to study the age dependent variation of caecal contents composition, a young rabbit was slaughtered out of 6 conventional litters at the age of 22; 25; 28; 32; 36; 42 and 56 days . Rabbits were fed a standard diet before and after weaning (at 28 days of age) . Daily growth and caecum size were determined . Caecal contents were analyzed for dry matter (DM), pH, crude protein (CP), neutral detergent fibre (NDF), ribonucleic acid (RNA), lactate, ammonia nitrogen and volatile fatty acids (VFA) . Between 22 and 25 days of age, a highly significant drop in CP content was found, associated with an increase in NDF content . RNA values tended to decrease with age, but it is striking that the RNA/CP ratio suggests that about 50% of CP is microbial N, very early in the development (22 days) . No significant changes of ammonia nitrogen concentration with age were observed, and lactic acid concentration showed some significant changes, suggestive of a decrease after weaning . Total VFA concentration is suggestive of a progressive and significant (P < 0.01) increase reaching a plateau after 42 days (83.7 mmoles/kg) . Molar proportions of propionate and butyrate varied significantly (P < 0.001) and inversely with age . Propionate drops by nearly 50% while butyrate proportion doubles between 22 and 56 days of age . The shift from a propionic to a butyric pattern occurs already at day 25 . Correlation analysis revealed significant associations between CP-NDF and RNA . The significant negative correlation between pH and daily weight gain reflects the relation caecal pH-animal health . PH was correlated with lactate and VFA concentration.

Crit Rev Oncog, 1995, 6(1), 47 - 56
Verruga peruana: an infectious endemic angiomatosis; Caceres-Rios H et al.; Microbial-related dysplastic and neoplastic angiomatous proliferative processes are seen with increased frequency, particularly in the acquired immunodeficiency syndrome (AIDS) . The microbial-encoded or -induced mediators of angiopathogenesis in AIDS-associated Kaposi's sarcoma and bacillary angiomatosis are actively being sought . The present review addresses the historical, epidemiologic, clinical, etio- and histopathogenic aspects of the verruga peruana (VP) . VP is a disease thus far endemic to high Andean valleys and characterized by dermal angioblastic proliferation in association with reactivation of latent Bartonella bacilliformis organisms . VP closely resembles AIDS-associated angiopathogenic manifestations at the clinical, histopathologic, and etiologic levels and therefore has been proposed as a model for the study of angiogenesis and endothelial cell dysplasia and neoplasia . Moreover, the recent epidemic outbreaks in endemic areas, the increased frequency of international travel to the region, the variable incubation period, and the possibility of not recognizing VP due to its rarity further underscore the relevance of studying this rare disorder and of including it in the differential diagnosis of angiomatous-proliferative disorders.

Pediatr Radiol, 1995, 25(8), 627 - 30
Radiographic patterns and viral studies in childhood pneumonia at various ages; Wahlgren H et al.; We aimed at evaluating the relationship between microbial etiology and chest radiograph appearance in various types of pneumonia . In a prospective study, the radiographic findings in 479 cases of acute pneumonia in children were compared with viral etiology and growth of potential bacterial pathogens in nasopharyngeal secretion . As the basis for viral etiology was most conclusive, the material was here classified according to the viral findings . The patients were divided into three age groups: 0-2, 3-5 and 6-15 years . The chest radiograms were analyzed blindly for the presence of hyperinflation and interstitial, alveolar and mixed interstitial-alveolar infiltrates . There was a statistically significant relationship between low age and occurrence of hyperinflation and interstitial infiltrates, and between high age and alveolar infiltrates . No unequivocal relationship was found between type of infiltrates or presence of atelectasis and proven viral etiology . We conclude that chest radiographs are not a useful indicator of microbial etiology in childhood pneumonia.

Annu Rev Microbiol, 1995, 49, 557 - 79
Biocatalytic syntheses of aromatics from D-glucose: renewable microbial sources of aromatic compounds; Frost JW et al.; Chemistry is moving into a new era in which renewable resources and starting materials such as D-glucose will likely be prominent features of industrial chemical manufacture . The keys to this progress are the design, development, and use of microbial biocatalysts . Aromatic biosynthesis serves as a paradigm for how biocatalysts can be manipulated to achieve the yield, rate, and purity criteria central to chemical manufacture . A disproportionate amount of the metabolic carbon flow of the biocatalyst must first be directed into the common pathway of aromatic amino acid biosynthesis . This review describes ways of achieving this goal through the traditional strategy of manipulating the catalytic activity of the first enzyme in the common pathway, as well as the amelioration of limitations in the in vivo availability of common-pathway enzyme substrates . The inability of individual enzymes to convert their substrate to product fast enough to avoid substrate accumulation further impedes carbon flow through the common pathway . This review also discusses identification and removal of these rate-limiting enzymes . Finally, we examine the creation of heterologous biocatalysts and how biocatalysis could be integrated with traditional chemical transformations to expand the number of organic chemicals that can be synthesized from glucose.

Med Trop (Mars), 1995, 55(3), 263 - 73
{Noma or cancrum oris: etiopathogenic and nosologic aspects}; Costini B et al.; Noma is a gangrenous disease that usually begins in the mouth and is characterized by rapid necrotizing destruction of soft tissue and underlying bone . The disease, which is associated with a strong putrid odor suggestive of mixed bacterial infection, develops only in predisposed persons, especially children whose natural defenses have been weakened by poor socio-economic living conditions . However a few atypical cases have recently been reported in adults in whom the main risk factor seemed to be immunodepression . The increasing number of wars in the Third World and the AIDS epidemic raise the likelihood that the number of cases of this disease will rise sharply particularly since the incidence has been grossly underestimated for many years . It now seems clear that a combination of local and systemic risk factors are implicated in the etiopathogenesis of noma with the common denominator being a weakened immune system . This would account for the fulminating course of the infectious process due to one or more opportunistic microbial or cytopathogenic agents or even to a still undetermined immunopathologic reaction that lead to massive tissue destruction . Poor understanding of the etiopathogenesis of noma is a major factor perpetuating the nosologic problems posed by this disease . Some authors add to the confusion by including a range of gangrenous diseases under the heading of noma . It is important that the term noma be applied only to necrotizing processes that begin in the mouth and present the characteristic features and course.

Caries Res, 1995, 29(6), 483 - 9
Effect of lactic acid and proteolytic enzymes on the release of organic matrix components from human root dentin; Dung SZ et al.; The mechanisms of organic matrix breakdown in the root caries process are not well understood . Therefore, the combined and separate effects of lactic acid and proteolytic enzymes on the degradation of human dentin collagen, glycoproteins, proteoglycans and phosphoproteins were investigated in the present study . Dentin powder was pretreated with lactic acid (pH 4.0), distilled and deionized (dd) water (pH 7.0) and EDTA/guanidine HCl (pH 7.4) for 24 h . Pellets of acid- or dd water-pretreated dentin powder were washed, dried, and then treated with trypsin, bacterial or mammalian tissue collagenase, or control buffer for 3 h . The released dentin proteins were analyzed by reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify degraded type I collagen, proteoglycans, glycoproteins and phosphoproteins . All water and acid pretreatment and enzyme treatment groups demonstrated two collagen fragment bands with molecular weights at approximately 79 kD . Further studies showed that the 79 kD proteins from acid-pretreated dentin collagen were degraded by tissue collagenase, suggesting that endogenous collagenase may be involved in the degradation of root dentin collagen . Dentin proteoglycans were detectable in all the treatment groups by protein slot blotting . Relatively few distinct glycoproteins and proteoglycans, and no phosphoproteins were detected by immunoblotting . Results from this study suggest that both acids and proteolytic enzymes from either host or microbial origin are important in the degradation of human dentin matrix and the mechanisms involved in the release of various noncollagenous proteins may be different.

J Basic Microbiol, 1995, 35(6), 433 - 9
Microbial transformation of isoprenoid systems by means of fungi of Zoophthora genus--microbial transformation of compounds with alpha-campholenic system by means of fungus Zoophthora (Neopandora) sp; Zabza A et al.; Unsaturated ketones (4 and 10) and epoxides (2-3 and 8-9) were the main products of biotransformation performed by means of Zoophthora (Neopandora) phyllobii . Enantiospecificity of both reactions leading to these compounds strongly depends on the distance of reacting fragment of molecule from the chiral center at C-1'.

Biosystems, 1995, 36(1), 19 - 35
Multistaged corpuscular models of microbial growth: Monte Carlo simulations; Hatzis C et al.; A new framework is developed by extending the existing population balance framework for modeling the growth of microbial populations . The new class of multistaged corpuscular models allows further structuring of the microbial life cycle into separate phases or stages and thus facilitates the incorporation of cell cycle phenomena to population models . These multistaged models consist of systems of population balance equations coupled by appropriate boundary conditions . The specific form of the equations depend on the assumed forms for the transition rate functions, the growth rate functions, and the partitioning function, which determines how the biological material is distributed at division . A growth model for ciliated protozoa is formulated to demonstrate the proposed framework . To obtain a solution to the system of the partial integro differential equations that results from such formulation, we adopted a Monte Carlo simulation technique which is very stable, versatile, and insensitive to the complexity of the model . The theory and implementation of the Monte Carlo simulation algorithm is analyzed and results from the simulation of the ciliate growth model are presented . The proposed approach seems to be promising for integrating single-cell mechanisms into population models.

Arch Tierernahr, 1995, 48(1-2), 147 - 58
{Evaluation of different markers for the determination of microbial nitrogen flow into the duodenum of dairy cows}; Schonhusen U et al.; 2,6-Diaminopimelic acid (DAPA), ribonucleic acid (RNA), 15N, D-alanine (D-ALA) and the amino acid profiles (AAP) were compared as microbial markers for determination of the microbial protein synthesis in the rumen . Three dairy cows (Schwarzbuntes Milchrind, LW 602 kg), each fitted with a rumen cannula and a re-entrant cannula in the proximal duodenum, were offered four isoenergetic and isonitrogenous diets (mean daily intake 15.0 +/- 0.45 kg DM; forage: concentrate = 50:50) in a periodic experiment . The diets contained soyabean extracted meal, meat and bone meal, pea meal and dried clover as major sources of protein . On the 4th day after administration of 9 g 15N-labelled urea (95 atom-% 15N-excess) per day, samples of rumen fluid and duodenal digesta were obtained 3 h after feeding . The bacteria were isolated by differential centrifugation . Bacteria harvested from the rumen had significantly higher 15N enrichment and D-ALA: N ratio than 'duodenal' bacteria . However, DAPA: N ratio was higher in 'duodenal' bacteria compared to rumen bacteria . There were no differences in RNA: N ratio between rumen and 'duodenal' bacteria . The source of the bacteria in the digestive tract has an influence on the ratio of microbial N: total N, especially when 15N, AAP, DAPA and D-ALA but not RNA were used as markers . The most reproducible method was D-ALA (C.V . 4.7 for rumen and 6.8 for 'duodenal' bacteria) followed by 15N (10.8 resp . 4.8) and RNA (9.7 resp . 8.2) . The results obtained with 15N and D-ALA agreed closely at the same source of bacteria . The RNA method reached the level of these markers (15N, D-ALA) when the bacteria were isolated from the duodenum . It is concluded that D-ALA (bacteria isolated from rumen and duodenum) and also 15N (bacteria isolated from duodenum) were the best markers for estimation of the microbial protein synthesis.

Arch Tierernahr, 1995, 48(1-2), 119 - 34
Transformations and effects of lipids in the rumen: three decades of research at Gent University; Demeyer DI et al.; A survey is given of research results on ruminant lipid digestion obtained at the authors' laboratory . Results are presented in terms of lipid changes occurring in the rumen and in terms of effects on nature, extent and site of digestion . The rumen can be adapted to an extremely high capacity for triglyceride lipolysis, preferentially releasing polyunsaturated fatty acids that are then further hydrogenated with accumulation of oleic acid isomers in vitro only . Evidence was obtained for both microbial incorporation and synthesis of polyunsaturated acids . In vitro lipolysis is inhibited by pH values below 6.3 and by ionophores . Free fatty acids inhibit methanogenesis with associated increases in propionate production and decreases in acetate and butyrate productions; the latter being related to their defaunating effect . Both in the faunated and defaunated rumen, free fatty acids decrease fibre digestion, which is shifted to the hindgut, at least in sheep . Defaunation increases rumen microbial growth efficiency and may result in a higher duodenal flow of both feed and microbial protein, provided these increases are not overcome by a decreased apparent rumen OM digestibility . Considerable between animal variability exists for these effects, associated with variable effects on rumen particle and liquid volumes and outflow rates.

Poult Sci, 1995 Jan, 74(1), 121 - 6
Effect of microbial phytase and 1,25-dihydroxycholecalciferol on dietary copper utilization in chicks; Aoyagi S et al.; Bile Cu accumulation in Cu-depleted chicks fed Cu concentrations between .56 and 1.56 mg Cu/kg (0, .5, or 1 mg supplemental Cu/kg) was used to investigate the effect of microbial phytase at 600 U/kg and 1,25-dihydroxycholecalciferol {1,25-(OH)2D3} at 10 micrograms/kg on Cu bioavailability from dehulled soybean meal (SBM) and cottonseed meal (CSM) . The bioavailability of Cu (relative to CuSO4.5H2O, which was set at 100%) in SBM and CSM was 43 and 39%, respectively . Phytase addition (600 U/kg diet) decreased Cu bioavailability in SBM to 21%, but did not affect that in CSM (34%) . Copper bioavailability in SBM was not affected by addition of 1,25-(OH)2D3 (10 micrograms/kg diet), but that in CSM was nearly doubled by 1,25-(OH)2D3 supplementation.

Immunology, 1995 Jan, 84(1), 105 - 10
Interaction between gamma delta T cells and B cells regulating IgG production; Hacker G et al.; Despite profound knowledge about the molecular structure of the gamma delta T-cell receptor (TCR), the physiological function of gamma delta T cells remains enigmatic . Participation of these cells in complex immune reactions, however, is suggested by the appearance of gamma delta T cells in sites of infectious and autoimmune-induced inflammations . Only a few in vitro models of gamma delta T-cell stimulation have been established: besides a reactivity in the presence of microbial ligands, human gamma delta T cells proliferate upon in vitro challenge with cells from an allogeneic B-lymphoblastic cell line (B-LCL) . We present data here demonstrating that this reactivity is not confined to allogenic B-LCL . Autologous B-LCL are also very strong stimulators for gamma delta T cells; more important, autologous B cells can stimulate gamma delta T cells after a period of mitogen-activation but not in a resting state . This activation seems to address a subgroup of gamma delta T cells, as the percentage of V delta 1+ cells is increased after stimulation . Activated gamma delta T cells, on the other hand, are able to exert an influence on B cells by inhibiting the secretion of IgG in coculture experiments . These data define a simple regulatory circle of B cells and gamma delta T cells in vitro and propose a model for gamma delta T-cell function which could explain many in vivo observations of gamma delta T-cell activation.

Appl Environ Microbiol, 1995 Jan, 61(1), 87 - 91
Persistence of inoculated hepatitis A virus in mixed human and animal wastes; Deng MY et al.; The persistence of hepatitis A virus (HAV) was determined both in mixtures of septic tank effluent (STE) with dairy cattle manure slurry (DCMS) and in mixtures of STE with swine manure slurry (SMS) . HAV was consistently inactivated more rapidly in the two types of mixed wastes than in STE alone or in the control Dulbecco's phosphate-buffered saline (PBS) . At 5 degrees C, the D values (time, in days, for a 90% reduction of virus titer) were 34.6 for the mixed STE and DCMS, 48.5 for the mixed STE and SMS, 58.5 for STE, and 217.4 for the Dulbecco's PBS control . At 22 degrees C, the D values were 23.0, 17.1, 35.1, and 90.1 for the four suspension media, respectively . A comparison of HAV inactivation in mixed wastes subjected to different treatments at the same pH and temperatures showed that the virus inactivation in the mixed wastes was related, at least in part, to microbial activity . In mixed STE and DCMS, the D values at 25 degrees C were 8.3 for raw mixed wastes, 15.1 for autoclaved mixed wastes, and 9.6 for bacterium-free filtrate of raw mixed wastes; D values at 37 degrees C were 6.8, 10.1, and 7.0 for these three suspension media, respectively . In mixed STE and SMS, the D values at 25 degrees C were 8.1 for raw mixed wastes, 14.3 for autoclaved mixed wastes, and 9.1 for bacterium-free filtrate of raw mixed wastes; the D values at 37 degrees C were 6.8, 9.4, and 6.9 for the three suspensions, respectively.

J Dent Res, 1995 Jan, 74(1), 345 - 50
Characterization of low-molecular-weight peptides in human parotid saliva; Perinpanayagam HE et al.; The low-molecular-weight components of human saliva remain poorly characterized . Therefore, low-molecular-weight peptides (Mr < 3000) have been purified from human parotid saliva and characterized with respect to their amino acid sequence . From the sequences obtained, it is likely that these peptides are derived from proteolysis of the hydroxyapatite-interactive human salivary proteins, histatins, proline-rich proteins, and statherins . Since human parotid saliva is an amicrobial fluid, much of the low-molecular-weight peptide fraction of this secretion appears to be derived from the proteolytic processing of the larger proteins . Because of their small size, these peptides are likely to be in exchange with dental plaque fluid and may therefore help modulate events such as demineralization/remineralization, microbial attachment, and dental plaque metabolism at the tooth-saliva interface.

J Antibiot (Tokyo), 1995 Jan, 48(1), 1 - 4
Terpendoles, novel ACAT inhibitors produced by Albophoma yamanashiensis . I . Production, isolation and biological properties; Huang XH et al.; A series of new acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors termed terpendoles were isolated from the culture broth of a fungal strain FO-2546 which was proposed to belong to a new genus designated as Albophoma yamanashiensis . Among four structurally related terpendoles, terpendole C showed the most potent ACAT inhibitory activity with an IC50 value of 2.1 microM in an in vitro enzyme assay, followed by terpendoles D (IC50: 3.2 microM), A (15.1 microM) and B (26.8 microM) . Evaluation of their ACAT inhibition in the cell assay using J774 macrophages indicated that terpendole D exhibited the highest specificity (cytotoxicity vs . ACAT inhibition) among microbial ACAT inhibitors we discovered so far.

Eur J Immunol, 1995 Jan, 25(1), 212 - 7
Spleen cells from antigen-minimized mice are superior to spleen cells from germ-free and conventional mice in the stimulation of primary in vitro proliferative responses to nominal antigens; Hooper DC et al.; T lymphocytes from mice reared under conditions of differential exposure to food, environmental and microbial antigens were compared for phenotypic shifts that may be associated with prior exposure to antigens as well as functional variations in the ability to respond to antigens de novo . While the intra-epithelial CD8 T cell compartment was found to differ significantly in the type of T cell receptor predominantly expressed, CD4 T cells from various lymphoid organs of conventionally reared specific pathogen-free (CL-SPF) mice showed only subtle phenotypic differences from cells obtained from antigen-minimized germ-free (AF) and germ-free (GF) mice . Cells derived from mice exposed to a reduced antigen load exhibited primary in vitro proliferative responses to antigens such as dinitrophenyl-keyhole limpet hemocyanin which were significantly enhanced when compared with similar responses of cells from conventional mice . In cell mixing experiments, differences in the reactivity of T cells from the spleens of AF, GF and CL-SPF mice were dependent on the source of the spleen cells employed as antigen-presenting cells (APC) . Experiments in which the T cell population was held constant revealed that, as APC, spleen cells from AF mice were most often superior to spleen cells from GF mice which were in turn considerably better than a similar population from SPF mice . We conclude that the enhanced primary reactivity of spleen cells from AF mice to nominal antigen in vitro is likely to be the result of a difference in the function and/or regulatory activities of the cell population employed as APC in this investigation.

Am J Gastroenterol, 1995 Jan, 90(1), 93 - 8
A novel stable isotope breath test: 13C-labeled glycosyl ureides used as noninvasive markers of intestinal transit time; Heine WE et al.; OBJECTIVES: Breath tests are widely used for diagnosis and control of treatment efficacy . There is a need for breath test substrates that reflect intestinal transit times under various conditions . METHODS: We synthesized a new class of breath test substrates, 13C-labeled glycosyl ureides, which are specific markers for the action of colonic microbial flora . We then investigated their usefulness as markers of intestinal transit time . RESULTS: Bolus ingestion of 1 g lactose or cellobiose 13C-ureide resulted in bacterial cleavage of the N-glycosyl bond and subsequent urea hydrolysis . 13CO2 appeared in breath and was determined by gas-isotope-ratio-mass spectrometry . Label first appeared after 5-6 h, peak excretion occurred between 8-14 h, and the signal returned to baseline after 18-24 h . Metoclopramide (10 mg) administered 1 h before the substrate advanced the onset of the signal by 2.4 +/- 1.95 h (mean +/- SD; n = 7; p < 0.05) and the time of peak response by 0.8 +/- 1.44 h . Loperamide (16 mg) broadened the peak and delayed the time of breath signal onset by 1.0 +/- 2.78 h and peak excretion by 4.0 +/- 3.7 h (p < 0.05) . CONCLUSIONS: The glycosyl ureide breath test reflected intestinal transit time and rapid changes in gastrointestinal motility . This test should be useful in the diagnosis of a variety of gastrointestinal motility disorders and in the development of drugs that affect gastrointestinal motility.

Int J Clin Lab Res, 1995, 25(1), 29 - 34
The role of cytokines in the acquired immunodeficiency syndrome; Yamamoto N; HIV replication in vitro is regulated by many factors, including various exogeneous stimuli and proteins encoded by either virus or cellular genomes . During the asymptomatic period, cells latently or chronically infected with HIV gradually express virus, leading to immunosuppression and opportunistic infection . These conditions would result in the increased secretion of cytokines, especially TNF, from infected and uninfected cells, which can induce HIV and killing of infected cells . A vicious circle is then set in motion in which heterologous microbial infections directly or indirectly activate HIV and the production of cytokines, thereby accelerating lymphocyte depletion and immunodeficiency . AIDS is a disorder of the immune network caused by a unique retrovirus HIV . However, if the whole story described above is true, this disease can also be termed a "cytokine disease" . Immunity resembles a "double-edged sword", with aspects not only protective, but also deleterious to the host . Therefore, it is essential to more extensively investigate the mechanism of cytokine regulation of HIV expression in vivo, not only to understand the complex pathophysiology of AIDS, but also to design a therapeutic strategy to halt this deadly disease.

Schweiz Monatsschr Zahnmed, 1995, 105(5), 629 - 32
{The intraoral bacterial colonization of temporary denture plastics}; Helfgen EH et al.; Plastic materials used for temporary crowns and bridges in prosthetic dentistry are investigated with regard to the possibility of their microbial colonization . For this purpose four different kinds of materials, i.e . Resincap, Trim, Snap (Polyalcylmethacrylate) and Protemp (Bisphenol-A-Glycidyl-Methacrylate) were chose . With the help of 10 test persons in vivo experiments were carried out . After a period of two weeks it could be verified, that the bacteria have a stronger affinity to Protemp than to Polyalcylmethacrylate . The hypothesis, that the different intensity of colonization is due to the roughness of certain surfaces could be confirmed by additional experiments.

Antonie Van Leeuwenhoek, 1995, 67(2), 181 - 200
Genes for beta-lactam antibiotic biosynthesis; Martin JF et al.; The genes pcbAB, pcbC and penDE encoding enzymes involved in the biosynthesis of penicillin have been cloned from Penicillium chrysogenum and Aspergillus nidulans . They are clustered in chromosome I (10.4 Mb) of P . chrysogenum, but they are located in chromosome II of Penicillium notatum (9.6 Mb) and in chromosome VI (3.0 Mb) of A . nidulans . Expression studies have shown that each gene is expressed as a single transcript from separate promoters . Enzyme regulation studies and gene expression analysis have provided useful information to understand the control of gene expression leading to overexpression of the genes involved in penicillin biosynthesis . Cephalosporin genes have been studied in Cephalosporium acremonium and also in cephalosporin-producing bacteria . In C . acremonium the genes involved in cephalosporin biosynthesis are separated in at least two clusters . Cluster I (pcbAB-pcbC) encodes the first two enzymes of the cephalosporin pathway which are very similar to those involved in penicillin biosynthesis . Cluster II (cefEF-cefG), encodes the last three enzymatic activities of the cephalosporin pathway . It is unknown, at this time, if the cefD gene encoding isopenicillin epimerase is linked to any of the two clusters . In cephamycin producing bacteria the genes encoding the entire biosynthetic pathway are located in a single cluster extending for about 30 kb in Nocardia lactamdurans, and in Streptomyces clavuligerus . The cephamycin clusters of N . lactamdurans and S . clavuligerus include a gene lat which encodes lysine-6-aminotransferase an enzyme involved in formation of the precursor alpha-aminoadipic acid . The N . lactamdurans cephamycin cluster includes, in addition, a beta-lactamase (bla) gene, a penicillin binding protein (pbp), and a transmembrane protein gene (cmcT) that is probably involved in secretion of the cephamycin . Little is known however about the mechanism of control of gene expression in the different beta-lactam producers . The availability of most of the structural genes provides a good basis for further studies on gene expression . This knowledge should lead in the next decade to a rational design of strain improvement procedures . The origin and evolution of beta-lactam genes is intriguing since their nucleotide sequences are extremely conserved despite their restricted distribution in the microbial world.

J Dairy Sci, 1995 Jan, 78(1), 161 - 71
In situ ruminal disappearance of essential amino acids in protein feedstuffs; Cozzi G et al.; Four protein sources were incubated in situ to estimate AA disappearance . Bags containing either soybean meal, corn gluten meal, herring meal, or meat meal were washed in water or suspended in the rumen of two Holstein cows for 8, 12, 16, 24, 48, 72, and 120 h . Cytosine, a bacterial marker for microbial contamination, was used to correct the essential AA profile for microbial contribution to determine the residual essential AA composition of the protein sources after incubation . Ruminal disappearance of individual essential AA was different among feedstuffs . Relative to original feed protein, soybean meal and corn gluten meal decreased the concentration of specific essential AA in the RUP . Concentration of all essential AA, except Arg and His, increased in undegraded meat meal protein . The difference between original and residual AA concentrations in herring meal approached statistical significance . Use of the original AA profile of the feed protein to predict essential AA available for absorption is not accurate because accuracy differs with sources.

Clin Infect Dis, 1995 Jan, 20(1), 1 - 8; quiz 9-10
Escherichia coli O157:H7: clinical, diagnostic, and epidemiological aspects of human infection; Tarr PI; E . coli O157:H7 is one of many E . coli organisms that contain genes encoding one or more toxins similar in structure and function to Shiga toxin . E . coli O157:H7 is the most frequently isolated diarrheagenic type of E . coli isolated in North America today; this pathogen can cause serious, even fatal disease . Syndromes caused by E . coli O157:H7 include diarrhea, hemorrhagic colitis, and HUS . Poorly cooked ground beef has been the most frequently implicated vehicle of transmission, but additional vehicles are being identified . Treatment consists of rehydration during hemorrhagic colitis and support of the patient during the multiple systemic complications of HUS . A policy of routine screening for E . coli O157:H7 in clinical microbiology laboratories, without reliance on the physician to request that this organism be sought or the technician to notice blood in the stool, is the most effective way to find cases . Timely and accurate diagnosis can prevent secondary transmission, avert unnecessary and possibly dangerous procedures and/or therapies, and detect continuing outbreaks . SLTEC strains other than E . coli O157:H7 may cause diseases similar to or less severe than those caused by E . coli O157:H7 . At present, however, screening for such pathogens in clinical laboratories is too labor-intensive to be practical . Education and legislation should promote safe food-preparation and food-handling practices . Research should be directed at reducing the carriage of E . coli O157:H7 at its bovine source, minimizing the microbial content of food and water, and averting systemic microangiopathic hemolytic anemia after infection with this pathogen.

Acta Otorhinolaryngol Belg, 1995, 49(1), 37 - 44
{Cervical complications in dental infections . Causes--diagnosis--treatment}; Boca P et al.; Head and neck complications due to dental infections . Six cases of deep neck infection are reported . The odontogenic origin was confirmed in five patients . In one case, the aetiology remained unknown . All case reports are discussed emphasizing cervical space anatomy, mixed microbial flora and potential iatrogenic treatment.

Clin Diagn Lab Immunol, 1995 Jan, 2(1), 62 - 8
Effect of malnutrition in Ecuadorian children on titers of serum antibodies to various microbial antigens; Brussow H et al.; The titers of serum antibodies to natural infection with enteric and respiratory pathogens, to a food antigen and to tetanus and diphtheria toxoid were evaluated by enzyme-linked immunosorbent assay in 1,554 Ecuadorian children younger than 5 years of age . The nutritional status of the children was assessed by anthropometry and measurement of biochemical status indicators . The children were enrolled in a representative national nutrition and health survey . Antibody titers were analyzed as a function of the nutritional status of the children . For 12 of 14 antibody concentrations tested, underweight children showed lower antibody titers than did control children . The difference was statistically significant for antibody to both T-cell-dependent antigens (tetanus toxoid, rotavirus, respiratory syncytial virus) and T-cell-independent antigens (lipopolysaccharide, polyribosyl-ribitol phosphate, capsular polysaccharide) . When children with a recent episode of diarrhea were excluded, many of the differences remained significant . When these children were further classified by age, only difference in titers of antibodies to respiratory syncytial virus and tetanus toxoid remained significant . No statistically significant difference was detected between underweight and control children with respect to protective antibody levels to four bacterial antigens . Anemic children showed significantly lower antibody levels to both T-cell-dependent and T-cell-independent antigens than did control children, and a higher proportion of anemic children had diphtheria antitoxin below a conservatively defined protective antibody level . No major differences in antibody titers were seen between children with different retinol and zinc concentrations in serum.

Int J Food Microbiol, 1995 Jan, 24(3), 407 - 12
Microbial degradation of amygdalin of bitter apricot seeds (Prunus armeniaca); Nout MJ et al.; Amygdalin is a cyanogenic glycoside occurring among others in almonds and bitter apricot seeds with interesting levels of dietary protein . Utilization of seeds for human or animal nutrition requires adequate detoxification . In the present paper, selected filamentous fungi (Mucor circinelloides, Penicillium nalgiovense) and yeasts (Hanseniaspora valbyensis, Endomyces fibuliger) were tested for their in-situ ability to decompose amygdalin . The latter (Endomyces fibuliger) was best able to grow on autoclaved bitter apricot seeds and detoxify them from 30 microMol CN/g dry matter to less than 1 microMol CN/g dry matter after 48 h of incubation at 27 degrees C.

Antimicrob Agents Chemother, 1995 Jan, 39(1), 79 - 86
Structure-activity and structure-selectivity studies on diaminoquinazolines and other inhibitors of Pneumocystis carinii and Toxoplasma gondii dihydrofolate reductase; Rosowsky A et al.; Twenty-eight 2,4-diaminopteridines with alkyl and aralkyl groups at the 6- and 7-positions, five 1,3-diamino-7,8,9,10-tetrahydropyrimido {4,5-c}isoquinolines with an alkyl, alkylthio, or aryl group at the 6-position, and nine 4,6-diamino-1,2-dihydro-s-triazines with one or two alkyl groups at the 2-position and a substituted phenyl or naphthyl group at the 1-position were evaluated as inhibitors of dihydrofolate reductase enzymes from Pneumocystis carinii, Toxoplasma gondii, and rat liver . Halogen substitution at the 5- or 6-position of 2,4-diaminoquinazoline favored selective binding to the P . carinii enzyme but not the T . gondii enzyme . For example, the 50% inhibitory concentrations of 2,4-diamino-6-chloroquinazoline as an inhibitor of P . carinii, T . gondii, and rat liver dihydrofolate reductase were 3.6, 14 and 29 microM, respectively, corresponding to 12-fold selectivity for the P . carinii enzyme but only marginal selectivity for the T . gondii enzyme . Greater than fivefold selectivity for P . carinii but not T . gondii dihydrofolate reductase was also observed for the 2,4-diaminoquinazolines with 5-methyl, 5-fluoro, 5- and 6-bromo, 6-chloro, and 5-chloro-6-bromo substitution . In contrast, alkyl and aralkyl substitution at the 6- and 7-positions of 2,4-diaminopteridines was found to be a favorable feature for selective inhibition of the T . gondii enzyme and, in two cases, for both enzymes . Nine of the fifty-one compounds tested against P . carinii dihydrofolate reductase and four of the thirty compounds tested against T . gondii dihydrofolate reductase displayed fivefold or greater selectivity for the microbial enzyme versus the rat liver enzyme . The most selective against both enzymes was 2,4-diamino-6,7-bis(cyclohexylmethyl) pteridine, with a selectivity ratio 2 orders of magnitude greater than the value reported for trimetrexate and piritrexim . Since substitution at the 7-position is generally considered to be detrimental to the binding of 2,4-diaminop-teridines and related compounds to mammalian dihydrofolate reductase, the selectivity observed in this study with the 6,7-bis(cyclohexylmethyl) analog may represent a useful approach to enhancing selective inhibition of the enzyme from nonmammalian species.

Important Adv Oncol . 1995;:3-18.
Interleukin-12: potential role in cancer therapy; Brunda MJ et al.; IL-12 is a heterodimeric cytokine that promotes cell-mediated immunity through its regulatory effects on T and NK cells . IL-12 produced endogenously in response to various microbial agents likely plays a role in the host response to infection by intracellular pathogens, and administration of rIL-12 to mice has bee shown to have dramatic therapeutic effects in a number of tumor models and models of infectious diseases . The relatively long serum half-life of IL-12 compared to other lower molecular weight cytokines such as IL-2 should permit more flexibility in dose scheduling . At doses which are efficacious in murine tumor models, IL-12 has been well tolerated . Phase I clinical trials with IL-12 in the treatment of human malignancies have recently been initiated . The results of such studies are required to determine whether the therapeutic potential IL-12 has displayed in murine disease models can be translated into clinical utility in man.

Chemotherapy, 1995, 41 Suppl 1, 20 - 32
Epidemiology of traveler's diarrhea; Castelli F et al.; Annually, over 75 million international passengers travel to tropical areas, more than 20 million of whom come from industrialized countries . They experience a high rate of traveler's diarrhea (TD), varying from 20 to 56%, which may result in serious limitations to their activities . The cause of TD is considered to be infectious in the overwhelming majority of cases and, apart from differences in relative importance, the list of responsible microbial agents is fairly constant regardless of geographic origin . The ingestion of contaminated food or water is considered to be the principal mode of transmission of the enteric pathogens of TD . Several factors have been proposed as playing a role in the etiogenesis of diarrhea in travelers, including personal (age, socioeconomic status, body weight, preexisting gastrointestinal illnesses), behavioral (mode of travel, standard of accommodation, eating in public places, dietary errors) and travel-related (destination, duration of stay, country of origin, season) factors, which are reviewed in detail.

Adv Exp Med Biol, 1995, 373, 103 - 13
Marijuana, receptors and immunomodulation; Friedman H et al.; THC, the major psychoactive component of marijuana, has been shown both in humans and experimental animals to have immunomodulatory properties . For example, marijuana smokers may show impaired immunological functions, including deficiency of blood leukocyte blastogenesis to mitogens . Detailed studies with mice have shown that animals given THC can show marked immunomodulation, including suppression of antibody formation, deficient cytokine production, etc . However, recent studies have also shown that lymphoid cells evince enhanced production or release or IL1, but suppression of IL2 and interferon production . Such lymphoid cells treated in vitro with THC also show suppressed blastogenesis to antigens and mitogens, suppressed NK activity, etc . In contrast, it has recently been shown that THC can enhance production or release of pro-inflammatory cytokines . This includes release of these cytokines from macrophages, including augmented release of IL1, TNF alpha, and IL6 activity . Susceptibility of mice to infection with opportunistic organisms such as L . pneumophila has been found and this increased susceptibility can be modulated by THC . A toxic shock-like death to Legionella has been induced by THC treatment given one day before and one day after infection . Receptors to THC have been detected in the brain as well as in peripheral tissues, including lymphoid cells . Thus, immunomodulation induced by THC may be related to receptor effects as well as unrelated to such receptors . It is clear that THC and other cannabinoids are excellent tools for studying the mechanisms of immune modulation, especially altered susceptibility to microbial infection.

Perspect Biol Med, 1995 Summer, 38(4), 605 - 23
The immune self: a selectionist theory of recognition, learning, and remembering within the immune system; Kradin RL; In this paper, I have briefly explored metaphors shared by the immune and nervous systems and shown that this exercise can lead to the elucidation of common principles of organization, as well as to predictions concerning how the immune system functions . Metaphor itself undoubtedly reflects the way in which we categorize and retrieve information 44}, so it is not surprising that the deep processes of language tend to sample information from related data categories . Although the nervous and immune systems are obviously not the same and metaphors are indeed just that, my primary goal has been to suggest that by virtue of their having evolved in parallel over millions of years, the nervous and immune systems currently use the same archetypal principles and strategies to address related challenges in information processing and retrieval . Ultimately, nature is conservative . One need only look at a tree, a river, the airways, or the vascular bed in order to see how a fractal pattern of repetitive dichotomous branching has been used by each, in order to optimize the transport of fluids over large distances {45} . While each system has had to adopt different materials in order to solve the problem, the shape of their solutions is remarkably alike . In the immune and nervous systems, the elements used to produce optimal functional responses are also quite different, but again the solutions have been achieved by comparable strategies . I am certain that these two great systems of information processing, each responding with vastly different kinetics, will prove to be far more integrally interdependent than has been previously recognized . For example, should a swift response by the immune system be required in an overwhelming invasion by microbial pathogens, the immune system may be able to cooperate with the rapidly reacting nervous system to rid the host of the invaders . In this regard, we have shown that the beta-adrenergic hormone epinephrine rapidly increases the traffic of memory T-cells to mucosal sites, presumably representing an immune component of the fight-or-flight response {46} . Neural evolution appears to have as its goal the development of more efficient information processing systems that lead to higher levels of consciousness . However, in modern times, technologic advances in information processing have rapidly outstripped the slower adaptations that can be made by evolution . In order to satisfy his compulsive quest for information, man has recently developed and recruited the aid of computers.(ABSTRACT TRUNCATED AT 400 WORDS)

Folia Biol (Praha), 1995, 41(2), 79 - 87
Functional characterization of peripheral blood neutrophils in patients with hyperthyroidism; Hrycek A; The thyroid hormones may exert an important effect on neutrophil functions which play a key role in the defence against microbial pathogens . Therefore investigations of the biological functions of neutrophils in peripheral blood of 80 women with hyperthyroidism were performed . The following functions of neutrophils were examined: nitroblue tetrazolium (NBT) reduction ability, phagocytosis, adherence to fibers as well as spontaneous migration of leukocytes and activity of lysozyme in serum . The total number of leukocytes and neutrophils was also determined . The results were compared with those in the control group consisting of 40 healthy women . The data show that in patients with hyperthyroidism, the number of leukocytes and neutrophils was decreased (respectively 4.90 x 10(9) +/- 1.20, 2.70 x 10(9) +/- 0.54 in patients, and 5.40 x 10(9) +/- 1.30, 3.00 x 10(9) +/- 0.74 in the control subjects), index of spontaneous reduction NBT was increased (17.1% +/- 4.5 in patients and 11.1% +/- 4.5 in the control group), index of phagocytosing cells was decreased (63.0% +/- 16.0, 80.3% +/- 14.0 in patients and 72.2% +/- 12.1, 87.4% +/- 12.0 in the control group), an increase in adherence (71% +/- 17 in patients and 58% +/- 10 in the control subjects), and a decrease in the lysozyme activity in undiluted and diluted serum was found (185 IU/ml +/- 85,209 IU/ml +/- 78 in patients and 284 IU/ml +/- 84,352 IU/ml +/- 140 in the control group).

Acta Haematol Pol, 1995, 26(2 Suppl 1), 86 - 92
{Objective and subjective screens for determining the effectiveness of allogenic bone marrow transplantation in hematologic diseases}; Lange A; 49 cases were reviewed with respect to the risk factors determining the outcome of alloBMT . The presence of HLA/MLC matched sibling or alternatively genetically haploidentical but phenotypically matched family or unrelated donor makes the transplantation possible . In the latter situation matching at the level of genomic DNA is advisable . Among prognostic factors stage of the disease and age of recipients play a significant role . More aggressive conditioning regime is associated with a risk of severe GvHD . A role of microbial status in promoting GvHD was discussed . An overall long term cumulative was 45% being higher in children (65%) and in patients in early stage of the disease (51%) . Acute GvHD causes majority of losses (24%) . Mild or moderate GvHD was associated with the highest survival due to a low risk of both transplant-related mortality and relapse . Unfortunately, a high proportion of patients were infected with hepatitis B or C virus.

Nat Toxins, 1995, 3(3), 129 - 37
Induction of apoptosis by T-2 toxin and other natural toxins in HL-60 human promyelotic leukemia cells; Ueno Y et al.; Based on the DNA fragmentation profile in gel electrophoresis and the morphological changes in electron microscopy, the induction of apoptotic nuclear changes by mycotoxins and other microbial products, in total 31 chemicals, was investigated in HL-60 human promyelotic leukemia cells, along with the cytotoxicity tests with 3-{4,5-dimethylthiazol-zyl}-2,5-diphenyltetrazolium bromide (MTT) and trypan blue exclusion . Among the chemicals tested, trichothecenes (T-2 toxin, roridin A, nivalenol, deoxynivalenol), certain anthraquinones (luteoskyrin, skyrin, 2-hydroxyemodin), diketopiperazines (emethallicin A, emestrin), isocoumarins (ochratoxin A, citrinin), lactone (penicillic acid), dihydrobisfuran (aflatoxin B1), potassium ionophore (valinomycin), and an inhibitor of interleukin-2 synthesis (cyclosporin A) were positive for the induction of DNA fragmentation . No DNA fragmentation was observed under the present conditions with fumonisin B1, cyclic peptides (cyclochlorotine, phalloidin, microcystin-LR), certain anthraquinones (emodin, chrysophanol, rugulosin), and others (sterigmatocystin, cytochalasin A, griseofulvin, fusaric acid, kojic acid, rubratoxin B, butenolide, wortmannin, FK506, and sphingosine) . The apoptotic changes in the cells exposed to T-2 toxin and luteoskyrin were confirmed by electron microscopic observation . Detailed experiments on dose and time dependencies revealed that T-2 toxin induced the apoptosis at 10 ng/ml (= 4 x 10(-8) M) levels within 2-6 hr without significant cytotoxicity evaluated by the dye exclusion and MTT.

Annu Rev Public Health, 1995, 16, 123 - 40
Microbial contamination of shellfish: prevalence, risk to human health, and control strategies; Wittman RJ et al.; There has been significant concern in recent times about the safety of molluscan shellfish for human consumption . Despite extensive efforts to assure a safe supply of molluscan shellfish, the number of cases of disease and death are still great enough to cause concern among the public . The number of cases of illness and death associated with the ingestion of shellfish falls in the lower end of the range of other similar microbial pathogen-related foodborne disease . Disease and deaths due to viruses and naturally occurring bacteria are now of greatest concern because they are the most often cited causative agents . The greatest risk of disease or death due to shellfish consumption is among the population with underlying health conditions who choose to consume raw shellfish . Control strategies to limit shellfish-borne disease should focus upon disease and death caused by viruses and naturally occurring bacteria among at-risk populations.

Annu Rev Immunol, 1995, 13, 399 - 415
Paracrine cytokine adjuvants in cancer immunotherapy; Pardoll DM; Advances in our understanding of the molecular events of antigen recognition by T cells and T cell activation are opening up new approaches to cancer immunotherapy . The identification and cloning of cytokines provide one important set of tools for manipulating immunologic responses . For cancer therapy, cytokines such as interleukin-2 have been administered systemically . However, systemic administration of cytokines ignores the paracrine nature of their action . Recently, an alternative approach has been explored that produces high concentrations of cytokines local to the tumor cells . This is achieved either by transduction of the tumor cells with the cytokine gene or by mixture of the tumor cells with cytokine containing biodegradable polymer microspheres . Under these circumstances, the locally released cytokine produces a strong local inflammatory response specific to the particular cytokine . In some cases, a potent tumor-specific T cell response results, capable of mediating regression of systemic tumor deposits . This paracrine delivery of cytokines can therefore be considered as a new type of adjuvant in the design of vaccines for cancer as well as microbial infections.

Biosens Bioelectron, 1995 Summer, 10(6-7), 517 - 26
An amperometric opiate assay; Holt PJ et al.; Current techniques for the detection and measurement of diacetylmorphine (heroin), morphine and their principal metabolite morphine-3-glucuronide (M3G) are based mainly on chromatography or immunoassay . No enzymatic method for the detection of these compounds has yet been reported . Two novel microbial enzymes have been isolated and characterized in this laboratory: an acetylmorphine carboxyesterase (heroin esterase) and a morphine dehydrogenase (MDH) . These highly specific enzymes have been incorporated in an amperometric assay for heroin and morphine using phenazine methosulphate as a mediator . The assay gives a rapid and sensitive response to heroin and morphine, with a detection limit for morphine of 6.8 micrograms ml-1 (23.7 microM).

J Anim Sci, 1995 Jan, 73(1), 267 - 77
Application of the Cornell Net Carbohydrate and Protein model for cattle consuming forages; Fox DG et al.; Accurate prediction of forage biological values and performance with animals fed forages requires accurately accounting for factors that influence animal requirements and feedstuff utilization . The Cornell Net Carbohydrate and Protein System (CNCPS) is an application model that uses a combination of mechanistic and empirical approaches to account for the effects of variation in animal factors and feed carbohydrate and protein fractions on animal performance . Thus, accurate animal and environmental descriptions, DMI, feed carbohydrate, and protein fractions and their digestion rates are required inputs . In 25 growth periods with calves fed high-forage diets, the CNCPS accounted for 74, 81, and 83%, respectively, of the variation in ADG predicted to be supported by the ME, metabolizable protein, and essential amino acid intake, the first-limiting of all three accounting for 81% of the variation with a -1% bias . Thus, the CNCPS can be used to accurately describe forage quality and the effects of changes in forage composition on animal performance . The model was sensitive to variations in NDF, CP, protein solubility, NDF and starch digestion rates, feed and microbial amino acid composition, maintenance protein requirement, body protein amino acid content, and the coefficient of efficiency of use of absorbed protein . Analysis of several trials indicates an improved efficiency of ME use with improved amino acid balances . Uses of the CNCPS discussed include interpreting, planning and applying research, teaching, developing tables of requirements and biological values for feeds, complex nutritional accounting, and predicting performance and profits.

J Orthop Trauma, 1995, 9(4), 303 - 11
Toxic effects of wound irrigation solutions on cultured tibiae and osteoblasts; Kaysinger KK et al.; Irrigating wounds with solutions of antiseptic or antibiotic agents is routinely performed in orthopaedic surgery to reduce the incidence of microbial infection . The effects of these agents on healthy bone tissue is unknown . Three commonly employed antiseptic agents (hydrogen peroxide, Betadine solution, Betadine scrub) and one antibiotic solution (bacitracin) were tested on tibiae and osteoblasts isolated from embryonic chicks . Osteoblast function was evaluated by glycolytic energy metabolism (lactate production), cell number (DNA content), and collagen synthesis ({3H}proline hydroxylation) . Two series of experiments were performed . To study concentration-related effects, tibiae or cells were exposed to a range of concentrations of the agents (diluted in saline, 0.9% NaCl) for 2 min, rinsed with saline, and incubated for 24 h in medium containing {3H}proline . For the recovery study, the cells were exposed to an effective, but nonlethal, concentration of the antiseptic agents for 2 min, rinsed with saline, and the incubation was continued in complete culture medium for 6, 12, 24, 48, or 72 h with {3H}proline added for the final 6 h . Solutions containing the antiseptic agents were cytotoxic to both bones and cells at concentrations well below those used clinically in irrigation solutions . In contrast, bacitracin at the concentrations tested was safe for osteoblasts and tibiae . These results suggest that the use of irrigation solutions containing H2O2, Betadine solution, or Betadine scrub on exposed bone tissue should be considered with caution.

J Cancer Res Clin Oncol, 1995, 121(9-10), 505 - 10
Antitumor antibiotics discovered and studied at the Institute of Microbial Chemistry; Takeuchi T; In 1951, we were pioneers in initiating screening of antitumor agents from microbial metabolites . We discovered bleomycin in 1962 and aclacinomycin in 1975 . Peplomycin, a derivative of bleomycin, and pirarubicin, a tetrahydropyranyl derivative of doxorubicin, were also studied . All of them have been clinically used for the treatment of cancer . Using new screening methods, we isolated spergualin in 1982 . This agent exhibited immunosuppressive activity as well as antitumor activity . Deoxyspergualin, a derivative of spergualin, is now clinically used for the treatment of acute rejection after kidney transplantation . Bestatin was screened as an inhibitor of aminopeptidase B in 1976 . It binds to the aminopeptidases located on the cell membrane of immunocompetent cells and modulates immune responses . It is now used for the treatment of acute non-lymphocytic leukemia . Microbial metabolites will become more important as a source of anticancer drugs in the future.

Transpl Int, 1995, 8(4), 327 - 9
Treatment of IgA deficiency in liver transplant recipients with human breast milk; Merhav HJ et al.; IgA deficiency is associated with high mortality (42% at 120 days) following liver transplantation (OLTx) . Most of the mortality has been associated with enteric infections . Mother's milk, or human breast milk (HBM), is a rich source of IgA that is considered to have beneficial effects in terms of protection from microbial translocation and enteric infections . Two IgA-deficient OLTx recipients were given HBM orally for 10 days perioperatively . HBM was given in order to replenish intestinal IgA . Both patients had an excellent infection-free post-operative course . IgA levels in the serum rose from 5 to 10 mg/dl in one patient and from 7 to 30 mg/dl in the other . No complications from HBM administration were observed . We conclude that HBM can be used in IgA-deficient liver transplant recipients to reduce the risk of infectious complications in the post-operative period.

Electrophoresis, 1995 Jan, 16(1), 39 - 42
Detection of pectinesterase in polyacrylamide gels; Alonso J et al.; A rapid and sensitive method of detecting pectinesterase activity following electrophoresis or isoelectric focusing in polyacrylamide gels is described . The method uses ruthenium red and requires no addition of substrate when making the gels, thus obviating direct enzyme-substrate contact during electrophoresis . Because of its versatility, the method can be used in a wide variety of applications, such as plant and microbial taxonomy, enzyme purification and characterization, or as an analytical method in fresh and processed plant technology.

J Antibiot (Tokyo), 1995 Jan, 48(1), 12 - 20
TAN-1323 C and D, new concanamycin-group antibiotics; detection of the angiostatic activity with a wide range of macrolide antibiotics; Ishii T et al.; We detected potent angiostatic activity in a MeOH extract from the mycelia of microbial strain S-45628 in the chick chorioallantoic membrane (CAM) assay . The producer was taxonomically characterized as Streptomyces purpurascens . Active principles designated TAN-1323 A-D were isolated and determined to be 18-membered macrolide antibiotics; components C and D are new members of this group, while components A and B are identical to concanamycins C and A, respectively . When tested in the CAM assay, components B and D gave huge avascular zones at the extremely low doses of 10-100 ng/disk, although components A and C showed far weaker activity due to their preferential tissue-damaging effect on the CAM . The discovery that these 18-membered macrolide antibiotics are angiostatic substances prompted us to examine other types of macrolide antibiotics, leading to the discovery that 16-membered macrolide antibiotics such as bafilomycin C1, tylosin and leucomycin also show angiostatic activity on the CAM . Thus, angiostatic potential is widely distributed among macrolide antibiotics . The mechanism of action of these macrolide antibiotics is also discussed.

Adv Neuroimmunol, 1995, 5(2), 171 - 88
Cytokines in sleep regulation; Krueger JM et al.; The central thesis of this essay is that the cytokine network in brain is a key element in the humoral regulation of sleep responses to infection and in the physiological regulation of sleep . We hypothesize that many cytokines, their cellular receptors, soluble receptors, and endogenous antagonists are involved in physiological sleep regulation . The expressions of some cytokines are greatly amplified by microbial challenge . This excess cytokine production during infection induces sleep responses . The excessive sleep and wakefulness that occur at different times during the course of the infectious process results from dynamic changes in various cytokines that occur during the host's response to infectious challenge . Removal of any one somnogenic cytokine inhibits normal sleep, alters the cytokine network by changing the cytokine mix, but does not completely disrupt sleep due to the redundant nature of the cytokine network . The cytokine network operates in a paracrine/autocrine fashion and is responsive to neuronal use . Finally, cytokines elicit their somnogenic actions via endocrine and neurotransmitter systems as well as having direct effects neurons and glia . Evidence in support of these postulates is reviewed in this essay.

Aliment Pharmacol Ther, 1995, 9 Suppl 1, 27 - 30
The role of Helicobacter pylori in gastritis and its progression to peptic ulcer disease; Blaser MJ; Helicobacter pylori infection is now recognized as the major cause of chronic gastritis throughout the world . A fraction of infected persons develop peptic ulcer disease or gastric cancer, accounting for its clinical significance . The pathophysiology of this infection can be better understood by considering five central concepts--heterogeneity of strains, persistence of infection, immunological down-regulation, physiological consequences and variability in outcome . Microbial, host and environmental factors must each contribute to the outcome variation.

Adv Immunol, 1995, 59, 369 - 455
The regulation of pulmonary immunity; Lipscomb MF et al.; No evidence has emerged which suggests that the principles of immunity derived from studies on cells from other body sites are contradicted in the lung and its associated lymphoid tissue . What is clear, however, is that the environment dictates the types of cells, their relationship to one another, and what perturbing events will set in motion either the development of an "active" immune response or tolerance . Investigating mechanisms for the development of lung immunity has increased our understanding of how human diseases develop and is continuing to suggest new ways to manipulate pulmonary immune responses . Demonstration that lung cells regulate both nonspecific inflammation and immunity through the expression of adhesion molecules and the secretion of cytokines offers hope for ways to design more effective vaccines, enhance microbial clearance in immunosuppressed hosts, and to suppress manifestations of immunologically mediated lung disease . Important lung diseases targeted for intensive research efforts in the immediate future are tuberculosis, asthma, and fibrotic lung disease . Perhaps even the common cold might be conquered . Considering the pace of current research on lung immunity, it may not be too ambitious to predict that these diseases may be conquered in the next decade.

Methods Enzymol, 1995, 253, 115 - 31
Use of synthetic peptides in characterization of microbial adhesins; Lee KK et al.; The characterization of microbial adhesins is greatly facilitated by the use of synthetic peptides . Synthetic peptides can be used to identify specific antigenic epitopes, to delineate receptor-binding domain of adhesins, and to facilitate the characterization of the adhesin, and they allow for a direct examination of structure-binding relationships.

J Biol Chem, 1994 Dec 30, 269(52), 32725 - 31
Cucumisin, a serine protease from melon fruits, shares structural homology with subtilisin and is generated from a large precursor; Yamagata H et al.; Cucumisin is a thermostable alkaline serine protease that is found in the juice of melon fruits (Cucumis melo L.) . We have determined the complete nucleotide sequence of a cucumisin cDNA (2,552 nucleotides) and deduced the corresponding amino acid sequence . The open reading frame of the cDNA consists of 731 codons and encodes a large precursor (molecular weight, 78,815) relative to the observed size of mature native cucumisin (67 kDa) . Sequence comparisons reveal that cucumisin has several features in common with the microbial proteases of the subtilisin family . The highly conserved sequences to the proximal regions of the catalytic triad amino acids Asp, His, and Ser, together with the substrate binding site in subtilisin, can be found within the deduced amino acid sequence of the protease domain of the cucumisin precursor . Cucumisin is the first known plant protease with such characteristics . Examination of the primary structure of cucumisin revealed that it is synthesized as a precursor, consisting of four functional domains: a possible signal peptide (22 amino acid residues), an NH2-terminal pro-sequence (88 residues), a 54-kDa protease domain (505 residues), which is the active enzyme domain of the 67-kDa native cucumisin, and a 14-kDa COOH-terminal polypeptide (116 residues), which arises by limited autolysis of the 67-kDa native cucumisin . This structure of cucumisin suggests that it is probably synthesized as an inactive precursor.

EMBO J, 1994 Dec 15, 13(24), 6143 - 51
A new class of DNA photolyases present in various organisms including aplacental mammals; Yasui A et al.; DNA photolyase specifically repairs UV light-induced cyclobutane-type pyrimidine dimers in DNA through a light-dependent reaction mechanism . We have obtained photolyase genes from Drosophila melanogaster (fruit fly), Oryzias latipes (killifish) and the marsupial Potorous tridactylis (rat kangaroo), the first photolyase gene cloned from a mammalian species . The deduced amino acid sequences of these higher eukaryote genes show only limited homology with microbial photolyase genes . Together with the previously cloned Carassius auratus (goldfish) gene they form a separate group of photolyase genes . A new classification for photolyases comprising two distantly related groups is proposed . For functional analysis P.tridactylis photolyase was expressed and purified as glutathione S-transferase fusion protein from Escherichia coli cells . The biologically active protein contained FAD as light-absorbing cofactor, a property in common with the microbial class photolyases . Furthermore, we found in the archaebacterium Methanobacterium thermoautotrophicum a gene similar to the higher eukaryote photolyase genes, but we could not obtain evidence for the presence of a homologous gene in the human genome . Our results suggest a divergence of photolyase genes in early evolution.

Nature, 1994 Dec 15, 372(6507), 691 - 4
Recognition of a lipid antigen by CD1-restricted alpha beta+ T cells; Beckman EM et al.; Major histocompatibility complex (MHC) class I and class II molecules bind immunogenic peptides and present them to lymphocytes bearing the alpha beta T-cell antigen receptor (TCR) . An analogous antigen-presenting function also has been proposed for the non-MHC-encoded CD1 molecules, a family of non-polymorphic, beta 2-microglobulin-associated glycoproteins expressed on most professional antigen-presenting cells . In support of this hypothesis, CD1 molecules are recognized by selected CD4-CD8- alpha beta or gamma delta TCR+ T-cell clones, and we have recently shown that CD1 molecules restrict the recognition of foreign microbial antigens by alpha beta TCR+ T cells . But the substantial structural divergence of CD1 from MHC class I and class II molecules, raises the possibility that the antigens presented by the CD1 system may differ fundamentally from those presented by MHC-encoded molecules . Here we report that a purified CD1b-restricted antigen of Mycobacterium tuberculosis presented to alpha beta TCR+ T cells is mycolic acid, a family of alpha-branched, beta-hydroxy, long-chain fatty acids found in mycobacteria . This example of non-protein microbial antigen recognition suggests that alpha beta TCR+ T cells recognize a broader range of antigens than previously appreciated and that at least one member of the CD1 family has evolved the ability to present lipid antigens.

Ann Allergy, 1994 Dec, 73(6), 457 - 68; quiz 468-70
Primary ciliary dyskinesia (the immotile cilia syndrome); Schidlow DV; OBJECTIVE: The purpose of this review is to familiarize the reader with the genetic aspects, clinical manifestations, diagnostic techniques and management of the primary ciliary dyskinesia syndrome . Further, this article illustrates some unusual features of this syndrome and discusses some speculative hypotheses concerning its pathogenesis and clinical presentation . DATA SOURCES: The bibliography includes references in English as well as some references of historical interest in German . Both human and veterinary literature are quoted . Sources included computerized bibliographic searches of recent literature and reviews of literature . STUDY SELECTION: Selection of papers was made based on their historic importance in the definition and characterization of the disease, and on reviews of large bodies of novel or interesting information . Some review papers were not included to avoid repetition . RESULTS: Although the incidence of primary ciliary dyskinesia is low, the inclusion of this condition in the differential diagnosis of chronic and recurrent sinobronchial disease in children and older individuals is very common . Primary ciliary dyskinesia should be suspected in individuals who present chronic respiratory symptoms already in the neonatal period, develop profuse, chronic mucopurulent rhinorrhea, and chronic otitis media and sinusitis . Chronic cough, obstructive lung disease, and bronchorrhea associated with the aforementioned manifestations should also make clinicians suspect this syndrome . Male sterility is almost universally present and situs inversus is present in 50% of affected persons . The diagnosis of primary ciliary dyskinesia is clinical and is confirmed by studies of ciliary motility and ultrastructure of the respiratory mucosa . Management is directed to microbial suppression by frequent antibiotic administration, and to clearing of retained secretions . CONCLUSIONS: The diagnosis of primary ciliary dyskinesia requires familiarity with the clinical picture and the specific techniques of identification . Although the basic mechanism of disease is known, the molecular genetics of primary ciliary dyskinesia and the causes for the phenotypic variability remain to be explained . Future research should be directed to the identification of the gene(s) responsible for the manifestations of the disease and to effective methods of activation, in vivo, of dysfunctional cilia.

J Leukoc Biol, 1994 Dec, 56(6), 672 - 86
Neutrophils, host defense, and inflammation: a double-edged sword; Smith JA; Neutrophils play important roles in host defense against all classes of infectious agents but, paradoxically, they are also involved in the pathology of various inflammatory conditions . Their microbicidal armory consists of oxidative and nonoxidative processes that are activated simultaneously upon phagocytosis . Although destruction of infectious agents occurs intracellularly, release of cytotoxic molecules into the extracellular milieu can damage body tissues . Neutrophils are heterogeneous . Subpopulations exist in various stages from dormant to primed to fully activated . The activities of neutrophils are regulated locally in microenvironments and systemically by a plethora of mediators including cytokines, "classical" neuroendocrine hormones, and bioactive lipids . The net response depends on a complex balance of stimulatory and inhibitory pathways that are regulated by these mediators . Although some effector and regulatory pathways are vital, considerable redundancy is also evident . Identification of the essential mediators and the unraveling of any interactions may be the keys to understanding the neutrophil paradox and developing therapeutic strategies that optimize microbial killing and minimize host tissue damage . Finally, reports that neutrophils can act as drug delivery vectors and that their function is influenced by stress and other lifestyle factors suggest that new homeostatic functions for these cells, outside their traditional roles in host defense and inflammation, remain to be identified: some are speculated on here.

J Immunol, 1994 Dec 1, 153(11), 4915 - 24
Active induction of unresponsiveness (tolerance) to DNFB by in vivo ultraviolet-exposed epidermal cells is dependent upon infiltrating class II MHC+ CD11bbright monocytic/macrophagic cells; Hammerberg C et al.; Contact sensitizers, tumor Ags, and microbial pathogens presented through UV-exposed skin result in T cell-mediated immune tolerance (inhibition of acquisition of responsiveness) to these normally potent immunogens . The APC in UV-exposed skin that delivers the signals inducing tolerance remains highly controversial and is the subject of this study . Application of the contact sensitizer, 2,4-dinitro-1-fluorobenzene (DNFB), to C3H/HeN mice immediately after a single dose of 72 mJ/cm2 UVB (138 mJ/cm2 total UVB) resulted in unresponsiveness to an initial DNFB ear challenge, but failed to block the development of responsiveness after a second sensitization on previously unexposed skin (no tolerance) . A state of tolerance could only be achieved if a delay of 72 h was allowed to elapse between the UV exposure and the initial sensitization . Epidermal cell suspensions (EC) were prepared from the skin of normal controls and from skin exposed to the same UV dose 3 days before (UV-EC) . Three days after in vivo UV exposure, Langerhans cells (CD11blow Ia+) were depleted, and CD11bbright Ia+ macrophages had appeared in the epidermis along with GR-1+ neutrophils . Intracutaneous injection of 2,4 dinitrobenzenesulfonic acid (DNBSO3)-haptenated UV-EC, but not normal controls, resulted in the induction of locally inducible Ag-specific tolerance to DNFB, indicating the presence and dominance of tolerogenic signal within in vivo-irradiated epidermis . Removal of CD11b+ and class II MHC+ cells within UV-EC showed that a CD11b+ class II MHC+ population was indeed critical for tolerance induction . In addition, tolerance induction by UV-EC was not a result of surviving, UV-exposed Langerhans cells, because haptenated 3-day cultured EC from epidermis removed 5 h after UV exposure (before leukocytic infiltration) failed to induce a tolerogenic state . In conclusion, the ability of UV-exposed skin to induce peripheral adult tolerance to a normally potent immunogen is critically dependent on inflammatory class II MHC+, CD11bbright monocytic/macrophagic cells that infiltrate UV-irradiated skin at the same time the ability to tolerize is acquired.

Am J Respir Cell Mol Biol, 1994 Dec, 11(6), 682 - 91
Regulation of the immunostimulatory activity of rat pulmonary interstitial dendritic cells by cell-cell interactions and cytokines; Armstrong LR et al.; Pulmonary dendritic cells (DC) are potent antigen-presenting cells that are thought to play a critical role in the initiation of immune responses within the lung . Because the lung is both a site of entry into the body for microbial pathogens and the organ of gas exchange, pulmonary immune responses must be meticulously regulated to achieve a balance between host defense and respiration . The initial interaction of DC with T cells in the lung is an excellent point at which to control local immune responses . Studies of the regulation of DC accessory cell function have been greatly hampered by difficulties in obtaining pure populations of pulmonary DC that have not been subjected to prolonged incubations during which the DC may undergo functional alteration . We now describe a method for isolating pulmonary DC from the rat that yields 1 x 10(5) cells/rat with > 90% purity . These cells are potent accessory cells, inducing T cell proliferation in a mixed leukocyte reaction (MLR) at a stimulator-to-responder ratio of 1:1,000 . This method, which involves flow cytometric separation of nonphagocytic cells that stain brightly for class II MHC (OX6) from a population of low-density pulmonary interstitial cells, avoids extended incubations at 37 degrees C and thus allows study of a relatively pure population of cells that have functional capacities resembling those of naive cells from the normal lung . With these cells, we demonstrate that the functional capacity of pulmonary DC as stimulator cells in an MLR is significantly increased by exposure to the cytokines interleukin-1 or granulocyte/macrophage colony-stimulating factor (GM-CSF) and by culture with interstitial, but not alveolar, macrophages . Furthermore, DC are heterogeneous with respect to the cell surface expression of receptor for GM-CSF, and this expression is subject to modulation in cell culture . From these studies, we conclude that the immunostimulatory capacity of pulmonary DC is a function of local interactions with cytokines and other parenchymal cells . This suggests that DC function may be an important regulatory point for the local control of pulmonary immune responses.

Trends Microbiol, 1994 Dec, 2(12), 485 - 9
Computer processing of microscopic images of bacteria: morphometry and fluorimetry; Wilkinson MH et al.; Several techniques that use computer analysis of microscopic images have been developed to study the complicated microbial flora in the human intestine, including measuring the shape and fluorescence intensity of bacteria . These techniques allow rapid assessment of changes in the intestinal flora and could apply equally to other complex microbial ecosystems.

Infect Agents Dis, 1994 Dec, 3(6), 275 - 8
"Teaching microbiology" vs . "learning microbiology"; Hinshaw VS; Microbiology is great! Our challenge is to convey that excitement to our students and to stimulate them to actively pursue knowledge about microbiology . Their future will be loaded with microbial issues, ranging from safety of the hamburgers they eat to the appropriateness of the therapies for their diseases . Thus it is critical that all of our students develop problem-solving skills in microbiology . In this article, I discuss ideas about current challenges, as well as opportunities, related to teaching and learning about microbiology.

Plant Mol Biol, 1994 Dec, 26(5), 1611 - 36
GTP-binding proteins in plants: new members of an old family; Ma H; Regulatory guanine nucleotide-binding proteins (G proteins) have been studied extensively in animal and microbial organisms, and they are divided into the heterotrimeric and the small (monomeric) classes . Heterotrimeric G proteins are known to mediate signal responses in a variety of pathways in animals and simple eukaryotes, while small G proteins perform diverse functions including signal transduction, secretion, and regulation of cytoskeleton . In recent years, biochemical analyses have produced a large amount of information on the presence and possible functions of G proteins in plants . Further, molecular cloning has clearly demonstrated that plants have both heterotrimeric and small G proteins . Although the functions of the plant heterotrimeric G proteins are yet to be determined, expression analysis of an Arabidopsis G alpha protein suggests that it may be involved in the regulation of cell division and differentiation . In contrast to the very few genes cloned thus far that encode heterotrimeric G proteins in plants, a large number of small G proteins have been identified by molecular cloning from various plants . In addition, several plant small G proteins have been shown to be functional homologues of their counterparts in animals and yeasts . Future studies using a number of approaches are likely to yield insights into the role plant G proteins play.

Microbiol Rev, 1994 Dec, 58(4), 641 - 85
Bacterial dehalogenases: biochemistry, genetics, and biotechnological applications; Fetzner S et al.; This review is a survey of bacterial dehalogenases that catalyze the cleavage of halogen substituents from haloaromatics, haloalkanes, haloalcohols, and haloalkanoic acids . Concerning the enzymatic cleavage of the carbon-halogen bond, seven mechanisms of dehalogenation are known, namely, reductive, oxygenolytic, hydrolytic, and thiolytic dehalogenation; intramolecular nucleophilic displacement; dehydrohalogenation; and hydration . Spontaneous dehalogenation reactions may occur as a result of chemical decomposition of unstable primary products of an unassociated enzyme reaction, and fortuitous dehalogenation can result from the action of broad-specificity enzymes converting halogenated analogs of their natural substrate . Reductive dehalogenation either is catalyzed by a specific dehalogenase or may be mediated by free or enzyme-bound transition metal cofactors (porphyrins, corrins) . Desulfomonile tiedjei DCB-1 couples energy conservation to a reductive dechlorination reaction . The biochemistry and genetics of oxygenolytic and hydrolytic haloaromatic dehalogenases are discussed . Concerning the haloalkanes, oxygenases, glutathione S-transferases, halidohydrolases, and dehydrohalogenases are involved in the dehalogenation of different haloalkane compounds . The epoxide-forming halohydrin hydrogen halide lyases form a distinct class of dehalogenases . The dehalogenation of alpha-halosubstituted alkanoic acids is catalyzed by halidohydrolases, which, according to their substrate and inhibitor specificity and mode of product formation, are placed into distinct mechanistic groups . beta-Halosubstituted alkanoic acids are dehalogenated by halidohydrolases acting on the coenzyme A ester of the beta-haloalkanoic acid . Microbial systems offer a versatile potential for biotechnological applications . Because of their enantiomer selectivity, some dehalogenases are used as industrial biocatalysts for the synthesis of chiral compounds . The application of dehalogenases or bacterial strains in environmental protection technologies is discussed in detail.

Microbiol Rev, 1994 Dec, 58(4), 603 - 15
Use of fluorochromes for direct enumeration of total bacteria in environmental samples: past and present; Kepner RL Jr et al.; Understanding the role of bacteria in microbial food webs is intimately connected to the methods applied in the direct enumeration of bacteria . We have examined over 220 papers describing studies in which fluorochrome staining followed by epifluorescent microscopic direct counts was used to estimate total bacterial abundances . In this review, we summarize patterns in the use of 3,6-bis{dimethylamino}acridinium chloride (acridine orange) and 4',6-diamidino-2-phenylindole (DAPI), the two stains most frequently used in bacterial enumeration . The staining of samples with these fluorochromes, followed by filtration and direct counting of bacterial cells on filter surfaces, has become routine over the past 10 years . We examine trends in features of the standard direct count methods, such as sample preservation and preparation techniques, membrane filter types used, applied stain concentrations, duration of staining, and counting strategies, in relation to the types of samples being examined . The high variability in bacterial counts observed within similar sample types may be partially accounted for by differences in methods . Synthesizing review findings, we include a recommended method for the direct enumeration of bacteria in environmental samples.

Epidemiol Mikrobiol Imunol, 1994 Dec, 43(4), 192 - 5
{Serologic detection of microbial diseases--present status and perspectives}; Votava M; The cost of serological diagnostic products amounts to more than a quarter of total laboratory material expenses . The major problem in serological diagnostics is correct interpretation of the presence of specific antibodies . Aspects influencing diagnostic conclusions drawn from serological finding include: 1 . Features of infectious agents and pathogenesis of infection . 2 . Principle of serological assay . 3 . Condition of antigen used in the assay . 4 . Individual reactivity of the patient . 5 . Temporal data and data on the course of the disease . Modern serological methods such as ELISA and indirect immunofluorescence have, compared to classical techniques (i.e . complement fixation test, agglutination, immunoprecipitation and neutralization), a number of advantages . Nevertheless, they also have drawbacks of and classical methods should be used at least in selected cases for a number of years in future . Novel approaches such as immunoblotting, body fluid antibody detection, IgA and IgE determination and low avidity antibody detection are gaining importance and promise new insights.

FEMS Microbiol Rev, 1994 Dec, 15(4), 369 - 410
Industrial production of heterologous proteins by fed-batch cultures of the yeast Saccharomyces cerevisiae; Mendoza-Vega O et al.; This review concerns the issues involved in the industrial development of fed-batch culture processes with Saccharomyces cerevisiae strains producing heterologous proteins . Most of process development considerations with fed-batch recombinant cultures are linked to the reliability and reproducibility of the process for manufacturing environments where quality assurance and quality control aspects are paramount . In this respect, the quality, safety and efficacy of complex biologically active molecules produced by recombinant techniques are strongly influenced by the genetic background of the host strain, genetic stability of the transformed strain and production process factors . An overview of the recent literature of these culture-related factors is coupled with our experience in yeast fed-batch process development for producing various therapeutic grade proteins . The discussion is based around three principal topics: genetics, microbial physiology and fed-batch process design . It includes the fundamental aspects of yeast strain physiology, the nature of the recombinant product, quality control aspects of the biological product, features of yeast expression vectors, expression and localization of recombinant products in transformed cells and fed-batch process considerations for the industrial production of Saccharomyces cerevisiae recombinant proteins . It is our purpose that this review will provide a comprehensive understanding of the fed-batch recombinant production processes and challenges commonly encountered during process development.

Gaoxiong Yi Xue Ke Xue Za Zhi, 1994 Dec, 10 Suppl, S62 - 6
Pest control industry and vector control activities in Taiwan; Wang CH et al.; At the end of 1993, there were 117 private pest control companies in Taiwan, with 438 technical managers and 274 technicians . Their business includes the control of mosquitoes, cockroaches, fleas, rodents, termites, houseflies, etc . Pyrethroids and some organophosphates are employed . At present, no applications of insect growth regulators or microbial agents are used by private pest control operators . During dengue epidemics they assist the government in space spraying with insecticides . The Environmental Protection Administration, Executive Yuan, R.O.C., is responsible for the training and management of pest control operators . In addition, the Administration is also in charge of affairs concerning the manufacture, import, registration and sale of environmental pesticides and microbial agents . It establishes protocols for testing the efficacy of insecticides and promotes pest control on the community level.

J Antibiot (Tokyo), 1994 Dec, 47(12), 1376 - 84
Panclicins, novel pancreatic lipase inhibitors . II . Structural elucidation; Yoshinari K et al.; Panclicins A-E are novel and potent pancreatic lipase inhibitors produced by Streptomyces sp . NR 0619 . Their structures have been elucidated based on NMR and FAB-MS experiments . The relative configurations have also been determined by NMR experiments . The absolute stereochemistry has been determined by the chiral HPLC analysis of the hydrolysates of panclicins A and B and by modified Mosher's method on a derivative of panclicin A . They are structurally related to beta-lactone esterase inhibitors of microbial origin, lipstatin, valilactone, ebelactones and esterastin . Panclicins also contain a beta-lactone structure with two alkyl chains, one of which has an N-formylalanyloxy or N-formylglycyloxy substituent.

Appl Environ Microbiol, 1994 Dec, 60(12), 4297 - 302
Mineralization of the herbicide atrazine as a carbon source by a Pseudomonas strain; Yanze-Kontchou C et al.; Strain YAYA6 was isolated from a mixed microbial community that was growing on atrazine as a sole carbon source and formed quantitative amounts of chloride and nitrate . This strain was identified as a member of the true pseudomonad group (RNA group I) and was given the designation DMS 93-99 . The growth yield when atrazine was the sole carbon and nitrogen source was 80 g (dry weight) of cells per mol of atrazine, and the cell doubling time was around 11 h . Approximately 20% of {U-ring 14C}atrazine was mineralized during primary degradation of atrazine . After atrazine disappeared from the culture supernatant, mineralization continued until the level of mineralization was more than 50% . Under different experimental conditions 10% of the atrazine supplied initially was converted to cyanuric acid and < 1% was converted to other s-triazines after prolonged incubation . Degradation proceeded via dechlorination and N-dealkylation . Atrazine was degraded until the concentration was circa 0.1 milligrams/liter . We obtained evidence showing that strain YAYA6 has specific uptake mechanisms for atrazine but less specific degradation mechanisms for s-triazines.

Biodegradation, 1994 Dec, 5(3-4), 249 - 57
Genetics and biochemistry of 1,2-dichloroethane degradation; Janssen DB et al.; Dichloroethane (1,2-DCE) is a synthetic compound that is not known to be formed naturally . Nevertheless, several pure microbial cultures are able to use it as a sole carbon source for growth . Degradation of 1,2-DCE proceeds via 2-chloroethanol, chloroacetaldehyde and chloroacetate to glycolate . The genes encoding the enzymes responsible for the conversion of 1,2-DCE to glycolic acid have been isolated . The haloalkane dehalogenase and an aldehyde dehydrogenase are plasmid encoded . Two other enzymes, the alcohol dehydrogenase and the haloacid dehalogenase, are chromosomally encoded . Sequence analysis indicates that the haloacid dehalogenase belongs to the L-specific 2-chloroproprionic acid dehalogenases . From the three-dimensional structure and sequence similarities, the haloalkane dehalogenase appears to be a member of the alpha/beta hydrolase fold hydrolytic enzymes, of which several are involved in the degradation of aromatic and aliphatic xenobiotic compounds.

Appl Microbiol Biotechnol, 1994 Dec, 42(4), 636 - 41
Metabolism of the polycyclic aromatic hydrocarbon pyrene by Aspergillus niger SK 9317; Wunder T et al.; The metabolism of pyrene, a polycyclic aromatic hydrocarbon consisting of four rings, by Aspergillus niger SK 9317 was investigated . The metabolites formed were isolated and identified as 1-hydroxypyrene, 1,6- and 1,8-pyrenequinone, 1,6- and 1,8-dihydroxypyrene, 1-pyrenyl sulphate and 1-hydroxy-8-pyrenyl sulphate . This is the first report of 1-hydroxy-8-pyrenyl as a metabolite in the microbial metabolism of pyrene . The results suggest that A . niger metabolizes pyrene by cytochrome P-450 monooxygenase enzyme systems.

Biotechnology (N Y), 1994 Dec, 12(13), 1357 - 60
Recombinant proteins can be isolated from E . coli cells by repeated cycles of freezing and thawing; Johnson BH et al.; Repeated cycles of freezing and thawing are sufficient to separate highly expressed recombinant proteins away from the cellular milieu of E . coli . Freezing and thawing liberates recombinant proteins from the bacterial cytoplasm, but does not release the bulk of endogenous E . coli proteins . Furthermore, protein secretion is not required . Fractionation of overexpressed proteins by freeze/thaw treatment does not depend on the identity of the recombinant protein and has been observed for thirty-five different recombinant proteins expressed in E . coli . These include proteins originally found in plant, animal or microbial sources, as well as several proteins designed de novo . Freezing and thawing typically yields approximately 50% of the recombinant protein in relatively pure form . Thus the freeze/thaw treatment can be utilized as a general method for the isolation of recombinant proteins from E . coli.

Environ Health Perspect, 1994 Dec, 102 Suppl 12, 45 - 8
Pollutant effects on the microbial ecosystem; Ford T; Genetic diversity of a microbial community will inevitably be affected by environmental stress . However, our understanding of the implications of these effects is limited . Genetic exchange between natural microbial communities appears to be a common phenomenon, mediated by a number of microbial processes (conjugation, transformation, and transduction) . These mechanisms of change are presumably adaptations to natural environmental perturbation, e.g., the low levels of antibiotics produced by other organisms . However, anthropogenic influences on the environment may be accelerating genetic change within microbiologic ecosystems, beyond these natural adaptation rates . This article highlights some of the perceived risks to ecosystem health and research questions that need to be addressed.

Hum Gene Ther, 1994 Dec, 5(12), 1457 - 66
Consequences of stable transduction and antigen-inducible expression of the human interleukin-7 gene on tetanus-toxoid-specific T cells; Kim JH et al.; Interleukin-7 (IL-7) has previously been shown to increase antigen-specific immune responses; the effect of IL-7 on human antigen-specific T cell lines has not directly been addressed . A tetanus-toxoid (TT)-specific T cell line exhibited increased proliferation in the presence of exogenous IL-7, suggesting that IL-7 may be useful in the potentiation of immune responses to defined microbial antigens . Murine retroviral vectors encoding the human IL-7 gene and the neomycin phosphotransferase gene (neoR) were packaged into murine retroviral particles, and supernatants containing these retroviral vectors were used to infect a CD4+ lymphoblastoid cell line . Stable integration of the retroviral vector and constitutive expression of the IL-7 gene were observed . Successful IL-7 gene transduction into TT-specific T cells was also accomplished . Detection of neoR DNA sequences and expression of IL-7-specific mRNA increased with selection in geneticin . Production of IL-7 in these cells was induced by exposure to TT . Production of IL-4, IL-6, and interferon-gamma (IFN-gamma) was detected after antigenic stimulation; there was, however, no effect of IL-7 on the pattern or kinetics of cytokine production by these cells . Human IL-7 transduced cells showed greater proliferation to TT than control T cells, particularly at subthreshold TT concentrations . These dta imply that genetic modification of antigen-specific T cells may be a plausible strategy for the study and manipulation of the immune responses to microbial pathogens.

J Am Mosq Control Assoc, 1994 Dec, 10(4), 574 - 84
Mosquito control then, now, and in the future; Mulla MS; This is a memorial lecture honoring the late Professor Stanley B . Freeborn of the University of California . In the spirit of his life-long academic and research interests in mosquitoes and mosquito-borne diseases, I am presenting here the evolution of vector control technology, especially that pertaining to mosquitoes and mosquito-borne diseases during the 20th century . Vector control technology in the first half of this century was relatively simple, utilizing source reduction, larvivorous fish, petroleum hydrocarbon oils, and some simple synthetic and botanical materials . During the 2nd half of this century, however, various classes of synthetic organic chemicals, improved petroleum oil formulations, insect growth regulators, synthetic pyrethroids, and microbial control agents were developed and employed in mosquito control and control of other disease-vectoring insects . Among these groups of control agents, petroleum oil formulations have endured to be used through the whole century . It is likely that petroleum oil formulations, insect growth regulators, and microbial control agents will provide the main thrust against vectors at least during the first quarter of the 21st century . It is also possible that effective tools through the development of vaccines and molecular entomology techniques might become available for the control of vectors and vector-borne diseases during this period of the 21st century.

Contraception, 1994 Dec, 50(6), 551 - 61
Lea's Shield, a new barrier contraceptive preliminary clinical evaluations three-day tolerance study; Hunt WL et al.; In this study the Lea's Shield was evaluated for its tolerance by women who wore the device for three consecutive days . Ten women who wore the Lea's Shield for 72 hours completed the tolerance study without adverse effects . Examination of the cervix and vagina revealed that the device did not provoke any significant cellular or microbial changes among the wearers . No major changes in the appearance or prevalence of vaginal flora occurred in the women after three days of wearing the device . A gradient in the pH could be detected between the contents of the vagina, which was more acidic than the contents of the bowl of the device . The range of cervical shapes and vaginal morphology among the study participants has had no influence upon the ability of the device to remain in its proper position . The device "settles in place" as it is pushed in, thereby obviating any special maneuvers for proper positioning . No vaginal nor cervical trauma occurred . We have concluded from these basic clinical evaluations that Lea's Shield is well tolerated during three days of use . Efficacy trials in women at risk recently completed have confirmed the high degree of acceptability and that the device can function adequately as one size fits allPIP: Ten women wore the newly developed vaginal barrier contraceptive Lea's Shield for 72 hours so researchers could evaluate its acceptability . It is made of soft, pliable, nonabrasive, medical-grade silicone that does not support bacterial growth . It is an elliptical, cup-shaped device that completely covers the cervix, but is held in place by the suction created by the vaginal wall around it rather than by the cervix . A valve vents the air between the device and the cervix during insertion, which allows the device to settle in position and to drain cervical secretions and menstrual flow . The U-shaped control loop serves as a guide during insertion into the vagina, stabilizes the device's position, and allows the wearer to remove the device . Lea's Shield did not cause any vaginal trauma . None of the women experienced any changes in cervical cytology during the 3-day use of Lea's Shield . The contents of the bowl of Lea's Shield were less acidic than the vaginal environment, which might reduce the survival time and motility of sperm . No major changes occurred in the vaginal flora . The position of the uterus did not affect the ability of Lea's Shield to settle in place . These findings suggest that Lea's Shield is well tolerated by women . These findings, combined with positive results of previously conducted postcoital studies and of a large-scale efficacy study, indicate that this new type of contraception can be a significant new woman-controlled addition to the assortment of contraceptives .

J Dairy Sci, 1994 Dec, 77(12), 3538 - 44
Factors affecting the ability of a high beta-galactosidase yogurt to enhance lactose absorption; Kotz CM et al.; Lactose in yogurt is better absorbed by lactase-deficient subjects than is an equivalent quantity of lactose in milk, presumably because of the microbial activity of the beta-galactosidase present in yogurt . In this study, we describe a process that increases the beta-galactosidase of yogurt 5- to 6-fold and the ability of this high lactase yogurt to enhance lactose absorption in lactase-deficient subjects . These subjects ingested the yogurt meals after a 12-h fast, and lactose malabsorption was determined by measuring breath hydrogen . Breath hydrogen was reduced 39% following ingestion of high lactase yogurt from that after consumption of conventional yogurt, indicating that the high lactase yogurt enhanced lactose absorption . However, the reduction after high lactase yogurt was less than expected, given the 5- to 6-fold increment in beta-galactosidase measured in vitro . In vivo activity of beta-galactosidase requires that the enzyme resist acid denaturation in the stomach . The beta-galactosidase in high lactase yogurt was much less acid resistant than was the beta-galactosidase in conventional yogurt, and the relative inability of high lactase yogurt to enhance lactose absorption was likely due to the destruction of the beta-galactosidase in the stomach.

Rev Saude Publica, 1994 Dec, 28(6), 454 - 63
{Treatment of human rabies: a summary of its history}; Schneider MC et al.; A historical review of the treatment of human rabies from ancient times up to the present is undertaken . An attempt is made to trace parallel between the concept of the main cause of rabies in a certain period and the kind of treatment utilized . The ancient Greek goddess Artemis was considered to be a healer of rabies; they already identified wound cauterization . People of the first century A.D . knew of the infection deriving from the saliva of a rabid dog and called it virus (in Latin) . During medieval times when a magical and religious concept regarding health was prevalent, the principal protector was called St . Humbert . During the Renaissance many experiments were carried out and new information on the disease was obtained, both were basic in opening the way for new findings in the future . At that time the miasmatic and contagious theories were predominant . Pasteur strongly objected to the idea of the spontaneity of rabies . At the end of the XIXth . century and based on microbial discoveries, Pasteur brought about a great scientific revolution as regards the possibility of treating rabies by using a vaccine . At the present time, vaccines are of the nervous type or not, and the recommended dose varies . A large-number of studies on vaccination have been undertaken . In Latin America the most used are those by Fuenzalida and Palacios . At present, WHO recommends the vaccine made by cell culture.

Clin Oral Implants Res, 1994 Dec, 5(4), 239 - 44
Microbial penetration along the implant components of the Brånemark system . An in vitro study; Quirynen M et al.; This study examined in vitro the existence of microbial leakage along the components of the Branemark implant system . Thirty-two implant/abutment assemblies were installed in a liquid blood medium previously inoculated with oral micro-organisms . To examine the leakage at the implant-abutment interface, 16 assemblies were partially immersed . The remaining 16 were completely immersed to observe the leakage at both the implant-abutment and abutment-prosthesis interface . After 7 days of anaerobic incubation, the micro-organisms in the internal part of the implants were collected and incubated on blood agar plates in anaerobic conditions . Micro-organisms were found in the completely immersed assemblies and at lower numbers in the partially immersed implants, indicating that bacterial leakage at both levels seems to exist . Several penetrating bacteria have been associated with peri-implantitis . The clinical importance of this bacterial leakage is not yet well understood . Although the longevity of the Branemark implants is well documented, this bacterial leakage might play a role in peri-implantitis, both in the etiology as well as in the treatment.

J Cell Biol, 1994 Dec, 127(5), 1477 - 83
Beta 2 integrin-dependent tyrosine phosphorylation of paxillin in human neutrophils treated with tumor necrosis factor; Fuortes M et al.; The focal adhesion protein paxillin undergoes tyrosine phosphorylation in response to signals mediated by integrins, neuropeptides and oncogene products, possibly via activation of the focal adhesion-associated kinase, p125FAK . In the present work, tumor necrosis factor-alpha (TNF) stimulated tyrosine phosphorylation of paxillin in human neutrophils . Cell adhesion and participation of the beta 2 integrin CD18 were necessary, but not sufficient, for the response . Adherent neutrophils also tyrosine phosphorylated paxillin in response to phorbol ester, formylmethionyl-leucyl-phenylalanine and opsonized bacteria . In contrast, p125FAK was constitutively tyrosine phosphorylated in a manner unaffected by adherence and/or TNF . Thus, cytokines and microbial products are among the stimuli that can induce the tyrosine phosphorylation of paxillin, and kinases other than p125FAK may be responsible . This is the first identification of paxillin and p125FAK in human cells and neutrophils, and one of the few identifications of a specific protein that undergoes tyrosine phosphorylation in response to any agonist in neutrophils or in response to TNF in any cell.

Sci Total Environ, 1994 Nov 25, 156(2), 139 - 43
Identification of metabolic intermediates in microbial degradation of phenol using laser desorption time-of-flight mass spectrometry; Xu N et al.; Laser desorption time-of-flight (LD-TOF) mass spectrometry was utilized to determine the metabolic intermediates in microbial degradation of phenol . The identified components were in good agreement with the well-documented pathway . This technique also demonstrated excellent precision . Analytical merits, instrumentation and methodology are discussed.

J Biol Chem, 1994 Nov 25, 269(47), 29462 - 7
Structure and biological activity of a 1,3-beta-D-glucan-binding protein in crustacean blood; Cerenius L et al.; The prophenoloxidase activating system, an enzyme cascade present in arthropod blood, has been shown to be involved in defense and recognition reactions . This system is converted to its active form by fungal 1,3-beta-D-glucans through binding to a plasma protein, a 1,3-beta-D-glucan-binding protein . Here the molecular cloning and carbohydrate composition of the 1,3-beta-D-glucan-binding protein from the freshwater crayfish Pacifastacus leniusculus are reported . It is also demonstrated that this protein can act as an opsonin, stimulating phagocytic uptake of yeast particles by isolated blood cells . The deduced amino acid sequence of 1,339 residues shows no significant similarity to proteins with similar functions in other animals such as the mannan-binding and lipopolysaccharide-binding proteins present in mammals . However, a short sequence motif with similarity to the active site of microbial 1,3-1,4-beta-D-glucan 4-glucanohydrolases was found to occur twice in the 1,3-beta-D-glucan-binding protein.

Cell, 1994 Nov 18, 79(4), 583 - 93
H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response; Levine A et al.; Microbial elicitors or attempted infection with an avirulent pathogen strain causes the rapid production of reactive oxygen intermediates . We report here that H2O2 from this oxidative burst not only drives the cross-linking of cell wall structural proteins, but also functions as a local trigger of programmed death in challenged cells and as a diffusible signal for the induction in adjacent cells of genes encoding cellular protectants such as glutathione S-transferase and glutathione peroxidase . Thus, H2O2 from the oxidative burst plays a key role in the orchestration of a localized hypersensitive response during the expression of plant disease resistance.

Biochem Biophys Res Commun, 1994 Nov 15, 204(3), 1150 - 7
Multiple effects on peripheral hematology following administration of recombinant human interleukin 12 to nonhuman primates; Bree AG et al.; Interleukin 12 has demonstrated a wide spectrum of bioactivity on T and NK cells both in vitro and in vivo . Therapeutic potential of these activities has been suggested by studies in murine tumor, viral and microbial models of disease . We have investigated the in vivo effect of rhlL-12 in cynomolgus monkeys treated with 1 micrograms/kg/day by bolus i.v . or s.c . injection for 5 days . Treated group transient decreases in total WBC counts as compared to controls, with reversable decreases seen mainly in the lymphocyte and monocyte subsets . Phenotypic analysis showed a decrease in the number of CD4+ and CD8+ cells/microL on Days 2 and 4 . Reversible thrombocytopenia and anemia were noted in both treated groups as compared to controls . Plasma neopterin concentrations were increased in both treated groups as compared to controls . These data show that rhlL-12 has multiple effects on peripheral hematology and suggests that this model may be useful to investigate in vivo bioactivity of rhlL-12.

Transplantation, 1994 Nov 15, 58(9), 1037 - 43
Disruption of T cell development and repertoire selection by calcineurin inhibition in vivo; Hollander GA et al.; The microbial products FK506 and CsA are potent immunosuppressive agents that prevent early transcriptional events in TcR-mediated activation . Their mode of action is dependent upon the inhibition of calcineurin, a serine/threonine phosphatase positioned within the calcium-dependent signaling pathway . TcR-mediated activation of thymocytes constitutes an important prerequisite for their development and selection to mature T cells . Disruption of the cross-talk between thymic APC and thymocytes results in the loss of normal T cell ontogeny . To study the role of calcineurin in T cell maturation and repertoire selection in vivo, mice were treated with either FK506 or CsA . Administration of either drug inhibited the progression of CD4+CD8+ positive thymocytes to mature single positive T cells . Furthermore, both drugs disrupted the process of negative thymic selection, causing an increased frequency of self-reactive cells among the few positively selected T cells . These effects correlated directly with the degree of inhibition of in vivo calcineurin enzyme activity . Blocking calcineurin activity appears to disrupt positive thymic selection and to prevent the deletion of self-reactive thymocytes.

Appl Environ Microbiol, 1994 Nov, 60(11), 3920 - 5
Evidence for microbial iron reduction in a landfill leachate-polluted aquifer (Vejen, Denmark); Albrechtsen HJ et al.; Aquifer sediment samples obtained from the anaerobic part of a landfill leachate plume in Vejen, Denmark, were suspended in groundwater or in an artificial medium and incubated . The strictly anaerobic suspensions were tested for reduction of ferric iron {Fe(III)} oxides, which was measured as an increase in the concentration of dissolved Fe(II) . Iron reduction did not occur when the medium was inoculated with inactive sediment and when the organisms in the inoculated medium were killed by formaldehyde, by chloroform, or by pasteurization, whereas the level of iron reduction was significant when living bacteria were present . Mixed cultures were obtained from the sediment samples, and differences in apparent iron reduction rates among the different cultures were maintained during several transfers . In addition, iron reduction was observed in unamended incubation mixtures containing whole sediment and groundwater . Synthetic amorphous Fe(III) oxides, as well as naturally occurring sediment-bound Fe(III) oxides, could be reduced by the cultures . Together, our results provide evidence that iron-reducing bacteria are present and microbial iron reduction occurs in the polluted aquifer sediments which we studied.

J Exp Med, 1994 Nov 1, 180(5), 1979 - 84
T cell cross-reactivity between coxsackievirus and glutamate decarboxylase is associated with a murine diabetes susceptibility allele; Tian J et al.; Limited regions of amino acid sequence similarity frequently occur between microbial antigens and host proteins . It has been widely anticipated that during infection such sequence similarities could induce cross-reactive T cell responses, thereby initiating T cell-mediated autoimmune disease . However, the nature of major histocompatibility complex (MHC)-restricted antigen presentation confers a number of constraints that should make this type of T cell cross-reactivity a rare, MHC allele-dependent event . We tested this prediction using two insulin-dependent diabetes mellitus (IDDM)-associated antigens, coxsackievirus P2-C (Cox P2-C) protein and glutamate decarboxylase (GAD65), which share a prototypic sequence similarity of six consecutive amino acids within otherwise unrelated proteins . We surveyed a panel of 10 murine MHC class II alleles that encompass the spectrum of standard alleles for the ability to cross-reactively present Cox P2-C and GAD65 . Out of the 10 restriction elements tested, the sequence similarity regions were both dominant determinants and were cross-reactively displayed after the natural processing of whole antigens, only in the context of I-Anod . These data show that cross-reactive T cell recognition of sequence similarity regions in unrelated proteins is confined to certain MHC alleles, which may explain MHC association with autoimmune disease . It is striking that these two diabetes-associated antigens were cross-reactively recognized only in the context of a diabetes susceptibility allele . Since the human and the murine class II alleles associated with IDDM share conserved features, cross-reactive T cell recognition of GAD65 and Cox P2-C may contribute to the pathogenesis of human IDDM and account for the epidemiological association of coxsackievirus with IDDM.

J Am Diet Assoc, 1994 Nov, 94(11), 1263 - 6
A cost-evaluation of glutamine-supplemented parenteral nutrition in adult bone marrow transplant patients; MacBurney M et al.; OBJECTIVE: In a randomized, double-blind, prospective clinical trial, we evaluated the metabolic effects of glutamine-supplemented parenteral nutrition in patients with bone marrow transplants . We compared hospital charge and cost data for the two groups of patients in the trial . DESIGN: Retrospective review . SETTING: Bone Marrow Transplant Unit, Brigham and Women's Hospital, Boston, Mass . SUBJECTS: Forty-three patients admitted to the Bone Marrow Transplant Unit were assigned randomly to receive either standard parenteral nutrition or an isocaloric, isonitrogenous parenteral nutrition solution containing glutamine starting on day 1 after bone marrow transplant . The two groups were well matched for diagnosis, antineoplastic treatment, and sex . MEASURES: The primary clinical end points evaluated were nitrogen balance, length of hospitalization, incidence of infection, and results of microbial culture . After completion of the study, we compared the hospital charges for the categories of room and board, surgery, laboratory, pharmacy, radiology, ancillary, and miscellaneous between the two groups of patients . STATISTICAL ANALYSIS PERFORMED: The two groups were compared using the unpaired t test or Mann-Whitney test for nonparametric measurements . A P value of < .05 was considered significant . RESULTS: Nitrogen balance improved in the glutamine-supplemented group compared with control subjects (-1.4 +/- 0.5 g/day vs 4.2 +/- 1.2 g/day, respectively; P = .002) . Length of hospitalization was significantly shorter in the glutamine-supplemented group than in the control group (29 +/- 1 day vs 36 +/- 2 days, respectively; P = .017) . The incidence of positive microbial cultures and clinical infection was also significantly lower with glutamine supplementation . Hospital charges were $21,095 per patient less in the glutamine-supplemented group compared with charges for patients who received standard therapy . Room and board charges were significantly different: $51,484 +/- 2,647 for the glutamine-supplemented group vs $61,591 +/- 3,588 in the control group (P = .02) . CONCLUSION: This intervention study using a new therapy demonstrated clinical and nutritional benefits to patients and cost savings to the hospital.

Analyst, 1994 Nov, 119(11), 2279 - 82
Recent developments in piezoelectric immunosensors . A review; Suleiman AA et al.; The development of piezoelectric (PZ) devices as immunosensors is reviewed . The recent advances in sensor design have stimulated great interest in PZ technology and facilitated diverse applications in a variety of matrices . Methods of antibody immobilization on crystals and several applications are reported including microgravimetric immunoassays, microbial toxins and other contaminants.

Poult Sci, 1994 Nov, 73(11), 1673 - 8
Adenosine triphosphate bioluminescence as a method to determine microbial levels in scald and chill tanks at a poultry abattoir; Bautista DA et al.; According to Hazard Analysis of Critical Control Points (HACCP) programs developed for the poultry industry, poultry processing waters should be actively monitored to minimize cross-contamination between chicken carcasses . In order to monitor HACCP programs, a test is required that provides results on a real time basis . A modified adenosine triphosphate (ATP) bioluminescence test has been developed that can assess microbial levels in poultry processing waters within 15 min . A study was conducted to determine the effectiveness of this test for examining scald, prechill, and chill tank waters . The results showed that the modified ATP bioluminescence method gave results comparable to plate counts . The microbial levels were dependent on the tank and the time of sampling . The highest microbial levels were detected in the scald tank . In all three tanks, the microbial levels increased over time during the day.

Oncol Nurs Forum, 1994 Nov-Dec, 21(10), 1687 - 94
A national survey of infection prevention practices on bone marrow transplant units; Poe SS et al.; PURPOSE/OBJECTIVES: To identify and describe bone marrow transplant (BMT)-specific infection prevention measures in the United States . DESIGN: Survey design using a mailed questionnaire . SETTING: BMT programs across the United States . SAMPLE: 91 BMT programs (80.5% response rate) . METHODS: A questionnaire containing both closed- and open-ended items was mailed to identified nurse contacts following introductory phone calls . Descriptive statistics were computed on responses to closed-ended questions; content analysis was performed on responses to open-ended questions . FINDINGS: Although all programs used some type of protected environment, practices varied considerably . Wide variation existed in cover-garment and hand-washing practices, regardless of the type of protected environment in use . Other protective measures included skin decontamination (69%), gut decontamination with oral nonabsorbable antibiotics (30%), antifungal therapy (73%), acyclovir therapy (82%), immunotherapy (73%), granulocyte-macrophage colony stimulating factor therapy (58%), and modified microbial diets (66%) . Numerous mouth care regimens, visitor and patient precautions, and environmental maintenance routines were described . CONCLUSION: Little standardization of infection-prevention practices exists nationwide . IMPLICATIONS FOR NURSING PRACTICE: Efforts should be made to test the cost effectiveness and benefits of the various measures in use prior to the development of national standards.

Clin Geriatr Med, 1994 Nov, 10(4), 703 - 18
Infections of the bone, joint, and bursa; Norman DC et al.; Infections of the skeletal system, specifically bone, joint, and bursa, cause major morbidity as well as substantial number of deaths in older patients . In this article, the discussion focuses on the cause, pathogenesis, microbial causes, diagnosis, treatment, and available preventive interventions of septic arthritis, prosthetic joint infection, setic bursitis, and osteomyelitis in elderly patients.

Immunology, 1994 Nov, 83(3), 347 - 52
gamma delta T cells play a crucial role in the expression of 65,000 MW heat-shock protein in mice immunized with Toxoplasma antigen; Nagasawa H et al.; Toxoplasma gondii is an obligate intracellular protozoan parasite and cellular immunity plays a crucial role in protection against infection with this pathogen . When mice are immunized with Toxoplasma homogenate, they readily acquire resistance against infection with a lethal dose of a low virulence Beverley strain of T . gondii . We have reported previously that expression of 65,000 MW heat-shock protein (hsp 65) in host macrophages closely correlates with protective potentials of hosts, while this protein is not expressed in Toxoplasma themselves . In this study, we examined the mechanism of expression of hsp 65 in mice immunized with Toxoplasma homogenate . Heat-shock protein was detected in peritoneal macrophages of BALB/c mice immunized 7 days previously by electroblot assay with a specific monoclonal antibody (mAb) for microbial hsp 65 . Furthermore, an immunogold ultracytochemistry assay demonstrated that this protein was expressed on the cell surface of peritoneal macrophages in immune mice . This expression was not induced in those of immune athymic nude mice and SCID mice . Treatment of BALB/c mice with anti-Thy-1.2 mAb 1 day before immunization led to an almost complete loss of the expression of hsp 65 . To determine the subsets of T cells responsible for induction of this protein, mice were depleted of gamma delta T cells, alpha beta T cells, CD4+ T cells or CD8+ T cells by treating with corresponding antibodies before immunization . From these experiments, gamma delta T cells were shown to be essential for the expression of hsp 65, although CD4+ alpha beta T cells also contributed to some extent . Thus, gamma delta T cells appear to play an important role in protective immunity against infection with T . gondii through mediating the expression of hsp 65 in host macrophages.

Br J Nutr, 1994 Nov, 72(5), 679 - 99
Simulation of the dynamics of protozoa in the rumen; Dijkstra J; A modified mathematical model is described that simulates the dynamics of rumen micro-organisms, with specific emphasis on the rumen protozoa . The model is driven by continuous inputs of nutrients and consists of nineteen state variables, which represent the N, carbohydrate, fatty acid and microbial pools in the rumen . Several protozoal characteristics were represented in the model, including preference for utilization of starch and sugars compared with fibre, and of insoluble compared with soluble protein; engulfment and storage of starch; no utilization of NH3 to synthesize amino acids; engulfment and digestion of bacteria and protozoa; selective retention within the rumen; death and lysis related to nutrient availability . Comparisons between model predictions and experimental observations showed reasonable agreement for protozoal biomass in the rumen, but protozoal turnover time was not predicted well . Sensitivity analyses highlighted the need for more reliable estimates of bacterial engulfment rate, protozoal maintenance requirement, and death rate . Simulated protozoal biomass was increased rapidly in response to increases in dietary starch content, but further increases in starch content of a high-concentrate diet caused protozoal mass to decline . Increasing the sugar content of a concentrate diet, decreased protozoa, while moderate elevations of the sugar content on a roughage diet increased protozoal biomass . Simulated protozoal biomass did not change in response to variations in dietary neutral-detergent fibre (NDF) content . Reductions in dietary N resulted in an increased protozoal biomass . Depending on the basal intake level and dietary composition, protozoal concentration in the rumen was either increased or decreased by changes in feed intake level . Such changes in relative amounts of protozoal and bacterial biomass markedly affected the supply of nutrients available for absorption . The integration of protozoal, bacterial and dietary characteristics through mathematical representation provided an improved understanding of mechanisms of protozoal responses to changes in dietary inputs.

Md Med J, 1994 Nov, 43(11), 977 - 80
Neutropenia and fever in patients receiving chemotherapy in a community teaching hospital: results of a retrospective chart review; Obadina M et al.; A retrospective chart review study of factors that may influence the outcome of cancer patients hospitalized with febrile neutropenia indicates that positive microbial cultures, older age, and hematologic malignancies may be associated with poor outcome (death during the hospitalization) . The absolute neutrophil count was statistically significant only in patients with positive cultures . Good outcome was associated with negative microbial cultures and shorter length of hospital stay.

Can J Microbiol, 1994 Nov, 40(11), 969 - 73
Detection of soluble methane monooxygenase producing Methylosinus trichosporium OB3b by polymerase chain reaction; Mohan KS et al.; The soluble methane monooxygenase (sMMO) enzyme complex of methanotrophs cometabolizes haloaliphatic compounds such as trichloroethylene . Two 18-mer oligonucleotides as primary primers and a nested primer of the same length were selected to amplify specific DNA sequences of the sMMO gene cluster using polymerase chain reaction (PCR) . Two DNA fragments of sizes 270 and 400 base pairs were obtained when purified DNA from the methanotroph Methylosinus trichosporium OB3b was used as template . The primers were specific for sMMO sequences of M . trichosporium, since none of the 13 bacterial isolates screened yielded the expected length of PCR-amplified DNA fragments . The detection limit of the PCR method was 5 x 10(2) cells of M . trichosporium . The sMMO sequences were successfully amplified in groundwater (containing native microbial population) when seeded with M . trichosporium, FP1 sense (5'-ATGTCCAGCGCTCATAAC-3'), RP1 antisense (5'-TCAGATGTCGGTCAGGGC-3'), FP2 sense nested (5'GCCATCATCGGTCAGGGC-3'), and FP2 sense nested (5'-GCCATCATCGAGGACATC-3').

J Ind Microbiol, 1994 Nov, 13(6), 361 - 6
Alternative method for rapidly screening microbial isolates for their potential to degrade volatile contaminants; Strong-Gunderson JM et al.; A method is described for rapidly screening the metabolic potential of bacteria to oxidize semivolatile and volatile compounds as a sole carbon source . The method is based on an automated system that utilizes Microplates manufactured by Biolog, Inc . (Hayward, CA, USA) . This system detects bacterial respiratory activity from the oxidation of a carbon source introduced in volatile form . This is in contrast to the original design, which is based on inoculating a carbon source directly into each well . The 96-well (MT) microtiter plates contain nutrients and a tetrazolium dye . When a bacterial species is capable of oxidizing a volatile carbon substrate, the dye turns purple, and a spectrophotometric plate reader quantifies the response . As a test of this method 150 isolates, including isolates known to degrade some of the test compounds and negative controls were evaluated for their potential to oxidize carbon tetrachloride, toluene, and o-xylene . Thirty-seven isolates (25%) were qualitatively identified as contaminant oxidizers, and thirteen of these (35%) showed significant degradation capabilities for both toluene and o-xylene.

J Anim Sci, 1994 Nov, 72(11), 2969 - 79
Ruminal characteristics, microbial populations, and digestive capabilities of newly weaned, stressed calves; Fluharty FL et al.; Eight ruminally fistulated steers, 7 to 8 mo old, were used in a completely randomized, 2 x 2 factorial experiment to determine the effects of energy density and protein source in receiving diets on in situ DM, NDF, and N disappearance, concentrations of ruminal bacteria, protozoa, ammonia, and pH . Two energy densities (1.80 and 1.48 Mcal/kg of NEm) and two protein sources (spray-dried blood meal {SDBM} and soybean meal {SBM}) were compared . Fistulated steers were weaned, transported by truck, and held in a sale barn before their arrival at the feedlot . On d 0 (day of arrival at the feedlot), DMI was 62% of DMI on d 7 after arrival . Overall, feeding a high-energy diet resulted in lower (P < .01) in situ DM disappearance (DMD) of orchardgrass than feeding a low-energy diet at both 24 and 48 h . In situ 24-h DMD averaged 46.6% on d-3 and 41.6% on d 0, whereas 48-h in situ DMD on d -3 and 0 averaged 58.2 and 58.6%, respectively, indicating the ruminal microbial population was not inhibited in its ability to digest available substrate . Additionally, there were no differences (P > .10) in 48-h in situ NDF disappearance between d -3 and 0 (58.8 vs 57.8%), respectively . No differences (P > .10) occurred in the concentration of total bacteria, or cellulolytic bacteria, due to feed and water deprivation . Concentration of total protozoa was lower (P < .05) on d 0 than at any other time . Entodinium averaged 72.5% of genera before weaning, and more than 90% of genera found on all treatments by d 21 . Diplodinium and Epidinium percentages tended to decline after weaning . Isotricha concentrations were low and Dasytricha were eliminated after d 7 . In conclusion, the concentration of ruminal bacteria and the ability to digest available substrate were not decreased immediately after weaning, trucking, and 24 h of feed and water deprivation.

J Anim Sci, 1994 Nov, 72(11), 2962 - 8
Isolation and characteristics of the protozoal and bacterial fractions from bovine ruminal contents; Martin C et al.; Four cows were fed once a day either a Cocksfoot hay diet (H) or a diet consisting of 65% hay and 35% pelleted ground barley (HB) . 15(NH4)2SO4 was continuously infused into the rumen as a microbial marker and ruminal digesta samples were collected during the 24-h postprandial period for the isolation of liquid-associated protozoa and bacteria (LAP, LAB) and particle-associated bacteria (PAB) . There were marked differences between ruminal pH diurnal variations with diets H and HB . Irrespective of the diet and sampling time, the chemical composition (OM, N, DAPA, 15N) of the protozoa was clearly different from that of the bacteria (P < .001) . The LAP contained more OM but less N and 15N than the bacterial fractions . The DAPA used to validate the isolation technique for the mixed ciliate population was not detected in protozoal fractions . The OM content of LAB was lower than that of PAB, whereas the N, DAPA, and 15N contents were higher . The observed effects of diet (P < .01) on LAP mean N contents were due to the different N contents of the LAP samples isolated 23 h after feeding and were correlated with the variation in the number of Endodiniomorphid protozoa (r = .72; P < .05) . The N content of LAB was not affected (P > .05) by diet but that of the PAB was increased on diet HB (P < .05) . The diet did not affect the 15N content of any of the three microbial populations . However, the 15N content of the bacteria decreased shortly after feeding (P < .001).

Appl Environ Microbiol, 1994 Nov, 60(11), 4059 - 65
merA gene expression in aquatic environments measured by mRNA production and Hg(II) volatilization; Nazaret S et al.; The relationship of merA gene expression (specifying the enzyme mercuric reductase) to mercury volatilization in aquatic microbial communities was investigated with samples collected at a mercury-contaminated freshwater pond, Reality Lake, in Oak Ridge, Tenn . Levels of merA mRNA transcripts and the rate of inorganic mercury {Hg(II)} volatilization were related to the concentration of mercury in the water and to heterotrophic activity in field samples and laboratory incubations of pond water in which microbial heterotrophic activity and Hg(II) concentration were manipulated . Levels of merA-specific mRNA and Hg(II) volatilization were influenced more by microbial metabolic activity than by the concentration of mercury . merA-specific transcripts were detected in some samples which did not reduce Hg(II), suggesting that rates of mercury volatilization in environmental samples may not always be proportional to merA expression.

J Med Chem, 1994 Oct 28, 37(22), 3701 - 6
Nitrogen-in-the-ring pyranoses and furanoses: structural basis of inhibition of mammalian glycosidases; Asano N et al.; Seven pyranoses and three furanoses with a nitrogen in the ring were prepared by chemical synthesis, microbial conversion, and isolation from plants to investigate the contribution of epimerization, deoxygenation, and conformation to the potency of inhibition and specificity of mammalian glycosidases . The seven pyranoses are 1-deoxynojirimycin (1), the D-manno (2), D-allo (3), and D-galacto (4) isomers of 1, fagomine (1,2-dideoxynojirimycin, 5), and the D-allo (6) and D-galacto (7) isomers of 5, while the three furanoses are 2,5-dideoxy-2,5-imino-D-mannitol (8), 1,4-dideoxy-1,4-imino-D-arabinitol (9), and 1,4-dideoxy-1,4-imino-D-ribitol (10) . The 2-deoxygenation and/or 3-epimerization of 1 enhanced the potency for rat intestinal lactase and bovine liver cytosolic beta-galactosidase . Especially compound 6 showed a potent inhibitory activity against both enzymes, and compound 8, a mimic of beta-D-fructofuranose, was a potent inhibitor of both beta-galactosidases as well . Compound 4, which has been known as a powerful alpha-galactosidase inhibitor, exhibited no significant inhibitory activity for most of mammalian beta-galactosidases . In addition, compound 6 fairly retained a potency of 1 toward rat intestinal isomaltase . In this study, compound 8, known as a processing alpha-glucosidase I inhibitor in cell culture, has been found to have no effect on processing alpha-glucosidase II, whereas 9 has been shown to be a good nonspecific inhibitor of intestinal isomaltase, processing alpha-glucosidase II, Golgi alpha-mannosidases I and II, and porcine kidney trehalase . It has been speculated that glycosidase inhibitors have structures which resemble those of the respective glycosyl cations . This Broad inhibitory activity of 9 toward various glycosidases suggest that it superimposes well on the various glycosyl cations.

Biochim Biophys Acta, 1994 Oct 18, 1219(2), 457 - 64
A birch gene family encoding pollen allergens and pathogenesis-related proteins; Swoboda I et al.; Bet v I, the major pollen allergen of birch (Betula verrucosa), shows high sequence homology to a family of pathogenesis-related (PR) proteins that have recently been identified in several other plant species . We have used a pollen Bet v I cDNA clone and anti-Bet v I antibodies as probes to study the expression of Bet v I genes in birch cell suspension cultures under different experimental conditions . Induction of Bet v I-related proteins was detected in immunoblots of cell extracts upon co-cultivation with microbial pathogens . Northern analysis revealed the rapid induction of Bet v I transcripts in the presence of bacteria and fungi, but not by stress treatments (heat shock, metal ions) or by chemical elicitors . RNase protection experiments showed that the pathogen-inducible RNAs did not correspond to the pollen cDNA clone but most likely to the products of transcription of other members of the Bet v I gene family, sharing high sequence homology with the pollen-specific gene within the 5'-half of the coding region . We conclude that the Bet v I gene family of pollen allergens includes a subset of defense-related genes that are transcriptionally activated in the presence of microbial pathogens.

Mutat Res, 1994 Oct 16, 310(2), 187 - 209
Comparative mutagenicity of chemicals selected for test in the International Program on Chemical Safety's collaborative study on plant systems for the detection of environmental mutagens; Grant WF et al.; A review has been made for the four compounds (maleic hydrazide, methyl nitrosourea, sodium azide, azidoglycerol) tested in the International Program on Chemical Safety's collaborative study on plant systems . Maleic hydrazide (MH) is a weak cytotoxic/mutagenic chemical in mammalian tissues and is classified as a class 4 chemical . In contrast, with few exceptions such as Arabidopsis, MH is a potent mutagen/clastogen in plant systems . The difference in its response between plant and animal tissue is likely due to differences in the way MH is metabolized . MH appears to be noncarcinogenic and has been given a negative NCI/NTP carcinogen rating . Methyl nitrosourea (MNU) is a toxic, mutagenic, radiomimetic, carcinogenic, and teratogenic chemical . It has been shown to be a mutagen in bacteria, fungi, Drosophila, higher plants, and animal cells both in vitro and in vivo . MNU is a clastogen in both animal and human cell cultures, plant root tips and cell cultures inducing both chromosome and chromatid aberrations as well as sister-chromatid exchanges . Carcinogenicity has been confirmed in numerous studies and involves the nervous system, intestine, kidney, stomach, bladder and uterus, in the rat, mouse, and hamster . MNU produces stage-specific teratogenic effects and also interferes with embryonic development . The experimental evidence that strongly indicates the mutagenic effects of MNU underlines the possible hazard of this compound to human beings . The experimental evidence for the stringent handling of this compound is clear . Sodium azide (NaN3) is cytotoxic in several animal and plant systems and functions by inhibiting protein synthesis and replicative DNA synthesis at low dosages . It is mutagenic in bacteria, higher plants and human cells and has been used as a positive control in some systems . In general, tests for clastogenicity have been negative or weakly positive . No evidence of carcinogenicity has been reported in a 2-year study seeking carcinogenic activity in male and female rats . Its advantages in comparison to other efficient mutagens are claimed to be a high production of gene mutations accompanied by a low frequency of chromosomal rearrangements and safer handling because of its nonclastogenic and noncarcinogenic action on humans . Azidoglycerol (AG) is a very potent mutagen in bacteria, yeast and higher plants including Arabidopsis and Tradescantia; however, it only slightly enhances the frequencies of recessive lethals in Drosophila . AG is at best a weak clastogen and is without effect in inducing chromosomal aberrations and SCEs in human peripheral lymphocytes in vitro . In microbial and plant systems, AG is considerably more potent than sodium azide in the maximal frequencies of mutation induced . In particular, in Saccharomyces cerevisae, AG is 3000-fold more mutagenic than sodium azide . Its carcinogenic and teratogenic properties are unknown.

J Mol Biol, 1994 Oct 14, 243(1), 116 - 22
Bacterial expression of catalytically active fragments of the multifunctional enzyme enniatin synthetase; Haese A et al.; Enniatin synthetase catalyzes the biosynthesis of N-methylated cyclohexadepsipeptides . The 347 kDa enzyme is encoded by the esyn1 gene of Fusarium scirpi and contains two domains (EA and EB) homologous to each other and to regions of other microbial peptide synthetases . Parts of the esyn1 gene were subcloned in frame to a small lacZ gene portion of Escherichia coli expression vectors . Overproduced recombinant proteins showed a high tendency towards inclusion body formation and could be only partially dissolved in 8 M urea or 6 M guanidine hydrochloride . After renaturation, a 121 kDa recombinant protein representing the N-terminal conserved domain EA of enniatin synthetase was shown to activate D-hydroxyisolvaleric acid via adenylation . Similarly, a 158 kDa recombinant protein comprising the C-terminal conserved domain EB catalyzed the activation of the substrate amino acid (e.g . L-valine) . Moreover, this protein could be photolabeled with S-{methyl-14C}adenosyl-L-methionine, (AdoMet) indicating the presence of the methyltransferase . Both functions, L-valine activation and AdoMet binding, could be assigned to a 108 kDa recombinant protein encompassing the A and the M segment of domain EB . The fact that a 65 kDa recombinant protein representing the M portion could be photolabeled, indicated the localization of the methyltransferase in this region . Three deletion mutants of the 65 kDa protein were shown to be inactive with respect to UV-induced AdoMet labeling.

Proc Natl Acad Sci U S A, 1994 Oct 11, 91(21), 10173 - 7
Community structure of a microbial mat: the phylogenetic dimension; Risatti JB et al.; Traditional studies of microbial communities are incomplete because of the inability to identify and quantify all contributing populations . In the present study, we directly determine the abundance and distribution of sulfate-reducing bacterial populations in a microbial mat community by using hybridization probes complementary to the 16S-like rRNAs of major phylogenetic groups . Most of the major groups were found in this single community, distributed for the most part in nonoverlapping depth intervals of the mat . The reflection of the phylogenetic structure in the community structure suggests that those species making up the major phylogenetic groups perform specific interrelated metabolic functions in the community . Comparison of population profiles to previously observed rates of sulfate reduction suggests there are additional populations of sulfate-reducing bacteria both within the photooxic zone and deeper in the mat.

Proc Natl Acad Sci U S A, 1994 Oct 11, 91(21), 10089 - 93
Constitutive and inducible nitric oxide synthase gene expression, regulation, and activity in human lung epithelial cells; Asano K et al.; Histochemical activity and immunoreactivity of nitric oxide synthase (NOS, EC 1.14.13.39) have been recently demonstrated in human lung epithelium . However, the molecular nature of NOS and the regulation and function of the enzyme(s) in the airway is not known . A549 cells (human alveolar type II epithelium-like), BEAS 2B cells (transformed human bronchial epithelial cells), and primary cultures of human bronchial epithelial cells all exhibited constitutive NOS activity that was calcium dependent and inhibitable by the NOS inhibitor NG-monomethyl-L-arginine . Nitric oxide production by epithelial cells was enhanced by culture in the presence of interferon gamma, interleukin 1 beta, tumor necrosis factor alpha, and lipopolysaccharide; the NOS activity expressed under these conditions showed less dependence on calcium, reminiscent of other inducible forms of NOS . Two distinct NOS mRNA species, homologous to previously identified constitutive brain (type I) and inducible hepatic (type II) NOS, were demonstrated by reverse transcription-polymerase chain reaction in all cell lines . Northern analysis confirmed the expression of inducible NOS mRNA . Cell culture with epidermal growth factor, a principal regulator of epithelial cell function, decreased inducible NOS activity by posttranscriptional action but did not affect constitutive NOS activity . The coexistence of constitutive and inducible NOS in human alveolar and bronchial epithelial cells is consistent with a complex mechanism evolved by epithelial cells to protect the host from microbial assault at the air/surface interface while shielding the host from the induction of airway hyperreactivity.

Am J Surg Pathol, 1994 Oct, 18(10), 1048 - 53
Mucous membrane plasmacytosis of the upper aerodigestive tract . A clinicopathologic study; Ferreiro JA et al.; We report 9 patients with an unusual plasma cell proliferative disorder of the upper aerodigestive tract . Six patients were men and three, women . The age at presentation ranged from 40 to 67 years with a mean of 54 years . Symptoms at presentation included dysphonia, dysphagia, difficulty breathing, and oral pain . These plasma cell lesions typically produced a cobblestone or warty appearance of the upper aerodigestive tract mucosa including the larynx, pharynx, palate, lips, mouth, tongue, and trachea in varying combination of multiple sites in each patient . Histologically, all lesions were characterized by psoriasiform epithelial hyperplasia with dyskeratosis and dense subepithelial plasmacytosis . Plasma cells were mature but so expansive and diffuse in infiltration as to suggest extramedullary plasmacytoma . Immunohistochemistry for kappa and lambda light chain showed polyclonal immunoglobulin content in all cases examined . Microbial cultures and Warthin-Starry stains were negative for organisms . A variety of treatments including antibiotic therapy, corticosteroid administration, and surgical resection were unsuccessful . In two patients, the process required tracheostomy . This disorder has not been previously described with the exception of a single reported case, which is included in this series . The etiology, pathogenesis, and successful management of mucous membrane plasmacytosis remain unknown.

Can J Microbiol, 1994 Oct, 40(10), 865 - 72
Adherence of Legionella pneumophila to U-937 cells, guinea-pig alveolar macrophages, and MRC-5 cells by a novel, complement-independent binding mechanism; Gibson FC 3rd et al.; In the absence of serum, Legionella pneumophila demonstrated wash-resistant adherence to U-937 cells, primary guinea-pig alveolar macrophages, and MRC-5 cells . Neither complement nor antibody was required for binding . The dynamics of adherence following inoculation of L . pneumophila at increasing 10-fold multiplicities of infection to each of the three host cell types resulted in a first-order kinetic relationship of binding, indicative of one bacterial adhesin molecule recognized by one host cell receptor moiety . Host cell receptor saturation studies showed that depending on the cell type, 2-8% of the bacterial inoculum adhered to cells under these nonopsonic conditions . Preliminary adhesin and receptor characterization studies were performed to define the chemical composition of the binding structures on both the organism and the three different host cell surfaces . The adherence phenomenon was investigated using competitive binding assays in the presence of putative adhesin analogs as well as following treatments modifying the microbial and host cell surface membranes . Attachment was evaluated both by viable bacterial cell colony counts and by indirect immunofluorescent assay . With the exception of aldehyde treatments, the various membrane-modifying regimes and the presence of the adhesin analogs were shown to have no effect on organism or host cell viability . Data suggested that the L . pneumophila adhesin responsible for opsonin-independent binding to these host cells was a protein structure with lectin-like properties . Furthermore, this protein would appear to be intimately associated with carbohydrate or lipid structures located on the bacterial outer membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Plant Cell, 1994 Oct, 6(10), 1485 - 93
Two divergent endo-beta-1,4-glucanase genes exhibit overlapping expression in ripening fruit and abscising flowers; Lashbrook CC et al.; Two structurally divergent endo-beta-1,4-glucanase (EGase) cDNAs were cloned from tomato . Although both cDNAs (Cel1 and Cel2) encode potentially glycosylated, basic proteins of 51 to 53 kD and possess multiple amino acid domains conserved in both plant and microbial EGases, Cel1 and Cel2 exhibit only 50% amino acid identity at the overall sequence level . Amino acid sequence comparisons to other plant EGases indicate that tomato Cel1 is most similar to bean abscission zone EGase (68%), whereas Cel2 exhibits greatest sequence identity to avocado fruit EGase (57%) . Sequence comparisons suggest the presence of at least two structurally divergent EGase families in plants . Unlike ripening avocado fruit and bean abscission zones in which a single EGase mRNA predominates, EGase expression in tomato reflects the overlapping accumulation of both Cel1 and Cel2 transcripts in ripening fruit and in plant organs undergoing cell separation . Cel1 mRNA contributes significantly to total EGase mRNA accumulation within plant organs undergoing cell separation (abscission zones and mature anthers), whereas Cel2 mRNA is most abundant in ripening fruit . The overlapping expression of divergent EGase genes within a single species may suggest that multiple activities are required for the cooperative disassembly of cell wall components during fruit ripening, floral abscission, and anther dehiscence.

Gan To Kagaku Ryoho, 1994 Oct, 21 Suppl 3, 302 - 9
{Preclinical studies for development of anti-cancer drugs: current and historical status and problems}; Okabe M et al.; In this review, we present the current and historical status of preclinical studies for development of new anti-cancer drugs . In our company, especially focusing on the stage of drug screening, pharmacology, toxicology and pharmacokinetic studies . We have discovered numerous new compounds with anti-cancer potential mainly with microbial origins, from which some drugs have been developed to clinical trials . We hope that clinical trials of drugs with a new mode of action will be designed and conducted with a more rational basis, and followed by analysis of the pharmacokinetics and pharmacodynamics so as to predict the toxicity and efficacy of the drugs in humans.

FEMS Microbiol Rev, 1994 Oct, 15(2-3), 195 - 215
Microbial metabolism of sulfur- and phosphorus-containing xenobiotics; Kertesz MA et al.; The enzymes involved in the microbial metabolism of many important phosphorus- or sulfur-containing xenobiotics, including organophosphate insecticides and precursors to organosulfate and organosulfonate detergents and dyestuffs have been characterized . In several instances their genes have been cloned and analysed . For phosphonate xenobiotics, the enzyme system responsible for the cleavage of the carbon-phosphorus bond has not yet been observed in vitro, though much is understood on a genetic level about phosphonate degradation . Phosphonate metabolism is regulated as part of the Pho regulon, under phosphate starvation control . For organophosphorothionate pesticides the situation is not so clear, and the mode of regulation appears to depend on whether the compounds are utilized to provide phosphorus, carbon or sulfur for cell growth . The same is true for organosulfonate metabolism, where different (and differently regulated) enzymatic pathways are involved in the utilization of sulfonates as carbon and as sulfur sources, respectively . Observations at the protein level in a number of bacteria suggest that a regulatory system is present which responds to sulfate limitation and controls the synthesis of proteins involved in providing sulfur to the cell and which may reveal analogies between the regulation of phosphorus and sulfur metabolism.

Ophthalmology, 1994 Oct, 101(10), 1738 - 44
Acute corneal hydrops in keratoconus; Tuft SJ et al.; PURPOSE: To determine the clinical factors associated with the development of acute corneal hydrops and its subsequent outcome . METHODS: The authors identified 147 eyes (124 patients) with acute hydrops from a database of 5242 eyes (2723 patients) with keratoconus . They compared the clinical features of patients in whom hydrops developed with unaffected patients and assessed the progression to penetrating keratoplasty by actuarial methods . RESULTS: Patients in whom acute hydrops developed tended to be younger males who had advanced corneal ectasia and a poor corrected Snellen visual acuity at the diagnosis of their keratoconus (P < 0.001) . Acute hydrops also was more common in the presence of severe allergic eye disease (P < 0.001) . The development of hydrops was a very significant risk factor for subsequently receiving a penetrating keratoplasty (P < 0.00001) and at the end of the study period 87 (59%) of the 147 eyes had surgery for visual rehabilitation . These eyes had a greater rate of graft rejection than eyes grafted without hydrops (P = 0.02) . After resolution of the hydrops, 46 of the 60 unoperated eyes had been refitted with contact lenses, of which 28 (61%) achieved a Snellen visual acuity of 20/40 or better, although a better visual acuity often was present in the contralateral eye . Microbial keratitis developed in two of these eyes after refitting . CONCLUSIONS: Although a penetrating keratoplasty often is indicated for visual rehabilitation after acute corneal hydrops, there is an increased rate of rejection . Only a minority of eyes were re-established in contact lenses after resolution of hydrops, but some patients achieved a functional level of visual acuity such that the procedure could be delayed or avoided.

Chest, 1994 Oct, 106(4), 1129 - 33
Gelatinolytic and type IV collagenolytic activity in bronchiectasis; Sepper R et al.; To evaluate the extracellular matrix (ECM) degradation in bronchiectasis (BE), the level of gelatinolytic and type IV collagenolytic activity was analyzed in bronchoalveolar lavage fluid (BALF) by using zymographies . The BALF of patients with bronchiectasis revealed a high gelatinolytic and type IV collagenolytic activity whereas no such activities were detected in BALF of the healthy controls . Furthermore, the level of degradative activity correlated with the severity of disease with a spectrum varying from patients characterized by frequent pneumonia and bronchitis, mucopurulent and purulent sputum production, and saccular changes of bronchi having high activities of both 92-kd and 72-kd gelatinases type IV collagenases (corresponding to the neutrophil type MMP-9 and fibroblast type MMP-2 activities, respectively) to patients having few clinical symptoms and displaying only a weak activity at the 92-kd area . These findings suggest a role for the matrix metalloproteinases MMP-2 (72-kd gelatinase/type IV collagenase) and MMP-9 (92-kd gelatinase/type IV collagenase) in the degradation of ECM of bronchial wall and lung tissue . In addition, severe bronchiectasis was associated with the presence of low-molecular weight gelatinases reflecting in vivo metalloproteinase activation and/or the presence of microbial-derived gelatinolytic proteinases.

Vet Immunol Immunopathol, 1994 Oct, 43(1-3), 151 - 6
The immune system of the respiratory tract in pigs; Pabst R et al.; Although the lung is not a lymphoid organ it contains large numbers of lymphocytes . These can be found in different compartments: (1) the pulmonary intravascular pool, which is organ-specific and shows a unique migration pattern; (2) the interstitial lymphocyte pool, which is equivalent in size to the whole blood pool; (3) the bronchus-associated lymphoid tissue (BALT) which develops as a result of microbial stimulation; (4) the intraepithelial and lamina propria lymphocytes of the bronchi, with their typical subset composition; (5) the lymphocytes in the bronchoalveolar space, which can be sampled by bronchoalveolar lavage . The size and kinetics of the lymphocyte pools have been studied in the pig in more detail than in most other species . Despite this organotypic compartmentalisation of the pulmonary lymphoid cells in the pig, the lung is part of the integrated mucosal immune system, as shown by protective oral immunisation against the lung-pathogenic bacteria Actinobacillus pleuropneumoniae . The lung immune system in the pig is not only of veterinary interest, but also a relevant model for the human respiratory tract.

Protein Eng, 1994 Oct, 7(10), 1189 - 95
Non-polar nuclei in fungal microbial RNases; Ilyin VA; An application of a previously proposed method for the analysis of the non-polar structure of proteins is presented . A detailed analysis of the composition and properties of non-polar nuclei and microclusters of fungal microbial ribonucleases has been performed on the basis of the 3-D structures of RNase T1 and related proteins . Three hydrophobic nuclei were found in these structures . It has been shown that all residues in non-polar nuclei have high homology (approximately 89%) . Residues in the nuclei are practically fully buried in the interior of a molecule . Detailed analysis of non-polar nuclei properties shows that these nuclei determine the hydrophobic core of a protein and the location and role of each residue in the non-polar interior of proteins . In addition it was found that there are variable residues not only on the surface of a protein but on the surface of the nuclei inside the protein and between the nuclei and that there is a consistent region in all proteins, the hydrophobic gamma-nuclei . An evaluation of the stability of non-polar nuclei, the conservation of their compositions and their positions in the protein globule, allows one to assume that these three nuclei play an important functional role in the stability and folding of molecules of RNases and possibly can be considered as independent structural elements of 3-D structures of these proteins.

Biomaterials, 1994 Oct, 15(12), 996 - 1000
In-vitro efficacy of an antibiotic releasing silicone ventricle catheter to prevent shunt infection; Schierholz J et al.; Infection due to implanted polymeric devices is a major problem in modern medicine . Microbial colonization of implants in neurosurgery, e.g . cerebrospinal fluid (CSF) shunts is the main reason for their failure, and often results in the consequent removal of the infected implants . In this paper we report on new approaches in the prevention of bacterial infections by incorporation of an antibiotic (rifampicin) into the polymer devices (silicone) . Drug release characteristics are investigated, and the physico-chemical mechanism of the delivery is discussed . Measurements of killing kinetics and the bacterial adhesion to the antibiotic-loaded silicone in a static adhesion assay reveal that only the liberation of high antibiotic doses over a period of weeks can prevent the bacterial colonization of the polymeric surface.

J Cell Biochem, 1994 Oct, 56(2), 150 - 4
Manipulation of cellular interactions with biomaterials toward a therapeutic outcome: a perspective; Pierschbacher MD et al.; Manipulation of the wound healing process and the manner in which tissues interact with inert biomaterials were both made possible with the discovery of arginine-glycine-aspartic (RGD) acid as a major cell recognition signal in the extracellular matrix . Whether promoting cell adhesion or selectively inhibiting cell-cell aggregation mediated by integrin cell surface receptors, RGD-containing peptides can be rationally designed to incorporate both stability and integrin specificity . Synthetic peptides containing this sequence have been linked to biodegradable biopolymers and introduced for the enhancement of dermal and corneal would healing . By accelerating the healing reaction using RGD-containing peptides, the quality of regenerated tissue seems to be improved, the extent of fibrosis restricted, and the risk of microbial infection may be reduced . Controlling the degree of fibrosis that often accompanies the healing of wounds and the reaction of tissue to foreign materials can also be achieved by natural antagonists of fibrogenic activity of TGF-beta animal models of kidney fibrosis . These advances in the biotechnology of wound healing and tissue regeneration eventually will have an overall impact on the quality of health care.

Biometals, 1994 Oct, 7(4), 287 - 91
Detection and differentiation of microbial siderophores by isoelectric focusing and chrome azurol S overlay; Koedam N et al.; Siderophores are microbial, low molecular weight iron-chelating compounds . Fluorescent Pseudomonads produce different, strain-specific fluorescent siderophores (pyoverdines) as well as non-fluorescent siderophores in response to low iron conditions . We present an isoelectric focusing method applicable to unpurified as well as to purified pyoverdine samples where the fluorescent siderophores are visualized under UV illumination . Siderophores from different Pseudomonas sp., amongst which are P . aeruginosa, P . fluorescens and P . putida, including egg yolk, rhizospheric and clinical isolates as well as some derived Tn5 mutants were separated by this technique . Different patterns could be observed for strains known to produce different siderophores . The application of the chrome azurol S assay as a gel overlay further allows immediate detection of non-fluorescent siderophores or possibly degradation products with residual siderophore activity . The method was also applied to other microbial siderophores such as deferrioxamine B.

J Clin Periodontol, 1994 Oct, 21(9), 638 - 40
The effect of porcelain laminate veneers on gingival health and bacterial plaque characteristics; Kourkouta S et al.; The aim of this study was to evaluate the response of microbial plaque and gingival inflammation to the placement of porcelain laminate veneers on anterior teeth . 9 patients, 7 female and 2 male (mean age of 30 years), with a total of 35 veneers were examined . The volume of gingival crevicular fluid (GCF), level of neutral proteolytic enzyme activity, gingival index (GI), plaque index (PlI) and plaque bacteria vitality were measured at baseline and after the placement of veneers . The volume of GCF increased after the placement of veneers (p = 0.03) . No statistically significant differences were found in proteolytic enzyme activity or GI (p > 0.05) . There were statistically significant reductions in PlI (p = 0.000) and plaque bacteria vitality (p = 0.018) . Further research is required to assess the long-term influence of porcelain laminate veneers on gingival health and microbial plaque characteristics.

J Clin Periodontol, 1994 Oct, 21(9), 615 - 20
Diagnosis of periodontal disease activity by detection of key microbial antigens; Smith GL; This paper reviews the development of various rapid microbial identification techniques and their potential role in the diagnosis of active periodontal tissue destruction . It also explores the concerns expressed by some, that although these techniques offer enormous promise as research tools, validation and translation of test results to clinical diagnosis, prognosis and treatment planning are still problematic . It may be premature to recommend these tests to clinicians in practice . Further longitudinal studies are required to establish the best use of these techniques in a clinical setting.

Chem Pharm Bull (Tokyo), 1994 Oct, 42(10), 2097 - 107
Synthesis and biological activity of new 3-hydroxy-3-methylglutaryl-CoA synthase inhibitors: 2-oxetanones with a side chain mimicking the extended structure of 1233A; Hashizume H et al.; Structural analogs of 1233A, a microbial metabolite inhibiting 3-hydroxy-3- methylglutaryl coenzyme A (HMG-CoA) synthase, were designed and synthesized . The 2-oxetanone moiety was left intact . All analogs prepared were tested for inhibition of HMG-CoA synthase activity and sterol synthesis in mouse liver and for effect on serum triglyceride levels . Of these analogs, trans-4-{2-{3-(7-carboxy-2- naphthyl)phenyl}ethyl}-3-hydroxymethyl-2-oxetanone (4a) showed the highest inhibitory activity in vitro, and also had in vivo inhibitory activity without causing any increase in triglyceride level.

Biotechnology (N Y), 1994 Oct, 12(10), 1012 - 6
A high capacity microbial screen for inhibitors of human rhinovirus protease 3C; McCall JO et al.; We have developed a high capacity screen for compounds that inhibit the 3C protease of human rhinovirus-1b . The assay uses a recombinant strain of Escherichia coli expressing both the protease and a tetracycline resistance-conferring protein modified to contain the minimal protease cleavage site . Cultures growing in microtiter plates containing tetracycline are treated with potential inhibitors and simultaneously monitored for change in growth over time using an oxygen probe . Most of the cultures, not containing an inhibitor of the 3C protease, show reduced growth due to cleavage of the essential gene product; normal growth is seen only in the infrequent culture that contains an inhibitor . In the present example, we have used the tetA gene of plasmid pACYC184 as the modified gene . The system has been validated using inhibitors of protease 3C, and has been used to identify three new inhibitors of the enzyme, active in the micromolar range.

Clin Immunol Immunopathol, 1994 Oct, 73(1), 27 - 37
A case of germinal center formation by CD45RO T and CD20 B lymphocytes in rheumatoid arthritic subchondral bone: proposal for a two-compartment model of immune-mediated disease with implications for immunotherapeutic strategies; Watson WC et al.; In rheumatoid arthritis (RA) disease activity occurring as joint destruction of cartilage and bone is thought to be driven by inflammatory reactions which are initiated by exogenous microbial mechanisms and perpetuated by endogenous autoimmune mechanisms . According to the synovial model of RA, these reactions originate in the adjacent synovial tissues . The following set of observations is presented herein to suggest an alternate model involving subchondral bone . Lymphocytic infiltrates accompanied by immunoglobulin deposits were identified in rheumatoid subchondral bone near areas of cartilage undergoing destruction by local subchondral inflammation . CD45RO T lymphocytes also were identified with these infiltrates as well as with CD20 B lymphocytes in an area of subchondral bone containing a well-organized germinal center . Analysis of extracts of rheumatoid subchondral bone revealed a high incidence of autoantibodies directed against type II collagen, the major protein constituent of cartilaginous tissue . Analysis of IgG subclass and cyanogen bromide peptide specificity revealed a pathogenic subset of these autoantibodies . A passive transfer study utilizing similar antibodies from collagen arthritic animals confirmed that such autoantibodies would have the potential of contributing directly to disease activity observed in rheumatoid subchondral bone . These studies suggest that (i) subchondral bone may be playing an active role in RA as a local site of immune-mediated disease activity and (ii) basic and therapeutic studies aimed at understanding and eventually controlling RA should be diversified to include the study of not only synovial tissue, but also subchondral bone as a local source of the antigenic, cellular, and humoral immune components of joint destruction.

Biochem Pharmacol, 1994 Sep 15, 48(6), 1211 - 7
Malformin-A1 inhibits the binding of interleukin-1 beta (IL1 beta) and suppresses the expression of tissue factor in human endothelial cells and monocytes; Herbert JM et al.; Malformin-A1, a cyclic pentapeptide of microbial origin, antagonized in a competitive manner the binding of 125I-IL1 beta (interleukin-1 beta) to human monocytes and cultured human umbilical vein endothelial cells (HUVEC) with IC50 values (doses which reduce specific binding by 50%) of 250 +/- 80 and 230 +/- 25 nM, respectively (N = 3) . IL1 increased in a dose-dependent manner the expression of tissue factor, a ubiquitous membrane-anchored glycoprotein that initiates blood coagulation at the surface of HUVEC and human monocytes . Malformin-A1 strongly inhibited IL1-induced tissue factor expression in HUVEC and monocytes with IC50 values of 420 +/- 35 and 105 +/- 25 nM, respectively (N = 3), and reduced IL1-induced expression of intercellular adhesion molecule-1 (ICAM-1, CD54) on HUVEC (IC50 = 125 +/- 18 nM) (N = 4) . These observations demonstrate that malformin-A1 recognizes and blocks IL1 beta binding to its receptor sites on monocytes and endothelial cells and protects these cells from IL1-induced procoagulant changes.

Science, 1994 Sep 2, 265(5177), 1401 - 4
Vaccine technologies: view to the future; Rabinovich NR et al.; The development of vaccines to prevent infectious diseases has been one of the most important contributions of biomedical science . Recent advances in the basic sciences are now fueling the development of a new generation of vaccines that will be based on rational design approaches . Two factors are making this possible: an improved understanding of the microbial factors required for virulence and the nature of the immune response to infection . The status of new vaccine technologies is summarized here.

J Allergy Clin Immunol, 1994 Sep, 94(3 Pt 1), 498 - 507
Characterization of skin prick testing responses for detecting sensitization to detergent enzymes at extreme dilutions: inability of the RAST to detect lightly sensitized individuals; Bernstein DI et al.; We observed that a group of detergent enzyme workers with known exposure to the subtilisin enzyme, Alcalase (Novo Industries, Bagsvaerde, Denmark), exhibited percutaneous sensitivity to Savinase (Novo Industries), a microbial protease, to which there was no previous occupational exposure . This was attributed to either cross-reactivity between these enzymes or to foreign enzyme contaminants contained in the Savinase antigen . The aims of this study were to determine the range of concentrations eliciting percutaneous responses to Alcalase and to another enzyme, Rapidase (an alpha-amylase) (Gist Brocades, Belgie, Netherlands); to compare the sensitivity of RAST and skin prick testing; and to characterize the relationship between wheal size and antigen concentration . Prick testing was conducted over six log10 antigen dilutions of Alcalase and Rapidase in 30 workers with previous exposure and skin reactivity to enzymes (group 1) and compared to nonexposed control groups, which included 60 atopic subjects (group 2) and 30 nonatopic subjects (group 3) . The RAST was performed with Alcalase and Rapidase antigens . The percutaneous threshold concentrations in group 1 subjects varied widely from 10(3) to 10(-3) micrograms of protein per milliliter . Of 19 group 1 workers with skin test reactivity to Alcalase, 84% had positive RAST results; 83% of 24 workers who were reactive to Rapidase had positive RAST results . It was concluded that skin prick testing is preferred over in vitro methods for longitudinal monitoring of human sensitization to workplace allergens . In addition, the data predicted that based on a known Alcalase level of 0.07% in Savinase, 26% of Alcalase-sensitized subjects could react to Savinase . An excellent correlation (r > 0.97) was found between log concentration of antigen and wheal size parameters, with the log diameter and log area performing equally as well (r > 0.98) . Analysis of variance revealed that more than 60% of intragroup variation represented human variability in wheal parameters at each concentration tested, whereas at least 95% of intergroup variation was due to regression . The excellent correlations of both wheal diameter and area with antigen concentrations were attributed to the very small changes observed between test concentrations.

J Bacteriol, 1994 Sep, 176(18), 5814 - 9
An unusual gene containing a dnaJ N-terminal box flanks the putative origin of replication of Mycoplasma genitalium; Bailey CC et al.; Origins of replication are known to be highly conserved among widely divergent microbial species, with the gene order in those regions being dnaA-dnaN-recF-gyrB . On the basis of sequence identities to entries in GenBank, the gene order of a 6-kb fragment of Mycoplasma genitalium DNA was determined to be dnaN-orf311-gyrB-gyrA-serS, which is structurally similar to the ancestral origin of replication . We have directly linked the dnaN gene to the M . genitalium dnaA gene by PCR amplification . However, we found a novel open reading frame, designated orf311, in place of an expected sequence encoding recF . Orf311 contains a DnaJ box motif at its N terminus, but it has no overall homology to any other protein or sequence in the database . We are unable to detect any recF homolog in M . genitalium by hybridization or during a random sequencing survey of the genome.

J Am Acad Dermatol, 1994 Sep, 31(3 Pt 1), 467 - 73
Atopic dermatitis: triggering factors; Morren MA et al.; Atopic dermatitis is a hereditary disorder, frequently associated with allergic rhinitis and bronchial asthma . The disease may be influenced by many triggering factors such as irritants, aeroallergens, food, microbial organisms, sex hormones, stress factors, sweating, and climatologic factors . Moreover, it is important to be aware of contact allergy as a complicating factor . This review deals with recent clinical, experimental, and some therapeutic data on these triggering factors.

Int J Cancer, 1994 Sep 1, 58(5), 730 - 5
Inhibition of growth of human tumor cells in nude mice by a metalloproteinase inhibitor; Naito K et al.; The effects of a new metalloproteinase inhibitor, BE16627B {L-N-(N-hydroxy-2-isobutylsuccinynamoyl)-seryl-L-valine, MW: 375.2} isolated from microbial cultures, on human tumor cell growth in nude mice were investigated . BE16627B inhibited metalloproteinases in enzyme assays, as well as gelatinolysis and collagenolysis in cell cultures . BE16627B at 100 micrograms/ml showed no apparent cytotoxicity to human tumor cells in culture and its LD50 in mice was more than 1,000 mg/kg (i.p.) . The effects of BE16627B on the in vivo growth of 2 human tumor cell lines were examined: HT1080 fibrosarcoma, which overproduces metalloproteinases, and HCT116 colon carcinoma, which barely secretes metalloproteinases . When BE16627B was administered to mice at 2 mg/mouse/day by an osmotic pump implanted s.c . for 3 weeks from 1 week after i.v . inoculation of HT1080 cells, the number and size of nodules of HT1080 cells on the lung surface were reduced to 24.3 and 46.4%, respectively, of those of controls, and the increase in lung weight due to tumor-cell growth was inhibited 85.5% without body-weight loss . Moreover, BE16627B inhibited 71.2% of the growth of HT1080 cells inoculated s.c . into mice under the same conditions, but did not significantly inhibit the s.c . growth of HCT116 human colon-carcinoma cells . Thus, BE16627B inhibited metalloproteinase-dependent human tumor-cell growth as well as lung colonization without showing cytotoxicity in nude mice.

Obstet Gynecol, 1994 Sep, 84(3), 343 - 8
Bacterial vaginosis in pregnancy and efficacy of short-course oral metronidazole treatment: a randomized controlled trial; McDonald HM et al.; OBJECTIVE: To characterize the natural history of bacterial vaginosis in pregnancy and to assess the efficacy of short courses of oral metronidazole therapy for long-term suppression of bacterial vaginosis flora . METHODS: This was a randomized, double-blind, placebo-controlled study of two 2-day courses of metronidazole (400 mg twice daily) in pregnant women with bacterial vaginosis (by Gram stain) and/or heavy growth of Gardnerella vaginalis . The first course was given at 24 weeks' gestation and a second course at 29 weeks if the follow-up vaginal swab grew G vaginalis . Follow-up swabs were performed at 28, 32, and 36 weeks' gestation . RESULTS: On the basis of their G vaginalis colonization, 196 women were enrolled, and 137 were evaluable for efficacy, including 66 with bacterial vaginosis . The microbial ecology of bacterial vaginosis in 36 women in the placebo group was relatively stable, with 72% persistence at 28 weeks and 57% at 32 weeks' gestation . Metronidazole effectively suppressed bacterial vaginosis for 4 weeks after the first course in 76%, compared with 28% in the placebo group, and had a cumulative efficacy of 87% compared to 44% 4 weeks after the second course (odds ratio 0.12, 95% confidence interval 0.03-0.5) . CONCLUSIONS: The microbial ecology of bacterial vaginosis in pregnant women is relatively stable . Long-term suppression of bacterial vaginosis flora for 2-3 months can be achieved by short courses of metronidazole therapy in 87% of women in mid-pregnancy . Because bacterial vaginosis has been associated with an increased risk of preterm labor, these findings provide the foundation for an intervention study of women with bacterial vaginosis in pregnancy.

J Anim Sci, 1994 Sep, 72(9), 2209 - 15
Interaction of forage level and monensin in diets for feedlot cattle on growth performance and digestive function; Zinn RA et al.; A feedlot growth-performance trial and a metabolism trial were conducted to evaluate the interaction of forage level (10 vs 20%) and monensin (0 vs 28 mg/kg, air-dry basis) on utilization of a steam-flaked corn-based finishing diet . There were no treatment interactions (P > .10) on feedlot cattle growth performance or site and extent of digestion of OM, ADF, N, and starch . Monensin supplementation did not influence (P > .10) ADG, DM intake, feed efficiency, estimated NE value of the diet, or ruminal and total tract digestibility of OM, ADF, and starch . Monensin decreased (14.5%, P < .10) passage of microbial N to the small intestine and ruminal digestion of feed N (10.4%, P < .05) . Ruminal pH tended to be slightly lower (1.9%, P < .10) with monensin supplementation . Monensin did not affect (P > .10) ruminal molar proportions of acetate and butyrate . There was an interaction between forage level and monensin on ruminal molar proportions of propionate . With the low-forage diet, molar proportions of propionate were 9.4% higher with monensin supplementation . In contrast, with the high-forage diet ruminal molar proportions of propionate were 5.5% lower with supplemental monensin . Monensin did not affect (P > .10) estimates of methane production . Decreasing the forage in the diet from 20 to 10% increased ADG (10.8%, P < .10), feed efficiency (11.6%, P < .01), and diet NEg (11.3%, P < .05) . Ruminal digestibility of ADF, OM, and starch were not affected (P > .10) by forage level.(ABSTRACT TRUNCATED AT 250 WORDS)

Scanning, 1994 Sep-Oct, 16(5), 307 - 11
Limitations in tandem scanning confocal microscopy as a diagnostic tool for microbial keratitis; Irvine JA et al.; One potential application of tandem scanning confocal microscopy is the detection of in vivo pathogens . Our study of an experimental model of Acanthamoeba keratitis demonstrates that while this technology can successfully detect certain organisms, there are currently limitations . These limitations relate to instrument configuration, movement of either the tissue or the microscope, difficulty in reproducibly returning to the area of interest for serial examination, the lack of a distinctive morphology of some pathogens, and limited resolution of the microscope.

J Periodontol, 1994 Sep, 65(9), 848 - 54
The influence of supragingival plaque control on clinical and microbial outcomes following the use of antibiotics for the treatment of periodontitis; Kornman KS et al.; Although supragingival plaque control is essential to successful periodontal therapy, the role of plaque control following systemic antibiotic use in periodontal disease has not been well defined . This study evaluated, following antibiotic use, which clinical and microbial parameters appeared to be influenced primarily by the antibiotics, independent of plaque control, and which outcomes appeared to be dependent on plaque control . Two hundred thirty-six patients (236) with moderate to severe periodontitis were clinically evaluated and microbial samples were taken by their private-practice periodontists . All patients were treated with scaling and root planing and a variety of systemic antibiotics, which were selected based on the microbial and clinical profile of the patient . Three months after therapy, patients were reevaluated and grouped by post-treatment plaque control, as either having very good oral hygiene (LoPl: N = 143; < or = 10% plaque-covered surfaces) or poor oral hygiene (HiPl: N = 93; > or = 25% plaque-covered surfaces) . The two groups had different plaque and bleeding scores initially, but similar numbers of pockets probing > 5 mm and similar microbial patterns . Although the LoPl group had a significantly greater reduction in plaque than the HiPl group, bleeding scores and probing depths changed comparably in both groups after antibiotic therapy . Plaque control influenced outcomes significantly, but in a complex manner . The LoPl group exhibited a significantly greater reduction in certain bacteria, for example P . gingivalis . Interactions between plaque control and specific microbial parameters significantly affected clinical outcomes, although neither alone was sufficient to predict outcomes following antibiotic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

J Periodontol, 1994 Sep, 65(9), 820 - 6
Actinobacillus actinomycetemcomitans in adult periodontitis . I . Topographic distribution before and after treatment; Mombelli A et al.; The aim of this investigation was to study the topographic distribution of Actinobacillus actinomycetemcomitans in patients with adult periodontitis before and after mechanical periodontal treatment (repeated oral hygiene instructions, systematic deep scaling, and root planing) . In 10 A . actinomycetemcomitans-positive patients, subgingival microbial samples were obtained from the mesial and distal aspect of every tooth (38 to 56 sites per patient, 479 sites in total) before and one month after treatment . The samples were cultured on TSBV agar . A . actinomycetemcomitans was identified based on phenotypical and serological criteria . A . actinomycetemcomitans was present in 40% of the samples taken before and in 23% of the samples taken after treatment . Before treatment, the frequency of A . actinomycetemcomitans-positive samples per patient was wide spread and ranged from 7 to 90% . After treatment, two patterns of A . actinomycetemcomitans distribution could be recognized: the majority of the patients showed only a limited percentage of positive samples and yielded less than 10(5) A . actinomycetemcomitans . In three subjects, however, relatively high numbers of positive sites were still present, and many of these positive sites showed high A . actinomycetemcomitans counts . Logistic multiple regression showed the presence of A . actinomycetemcomitans before treatment depended strongly on the individual and was significantly associated with probing depth (P < 0.001) and bleeding upon sampling (P = 0.07) . The highest chance of detecting A . actinomycetemcomitans existed in deep pockets which bled upon sampling . After treatment, there was a strong individual influence and an influence of probing depth (P < 0.001) . The highest chance of detecting A . actinomycetemcomitans existed in residual pockets in the range of 5 mm.

J Nihon Univ Sch Dent, 1994 Sep, 36(3), 191 - 8
Use of membranes containing 20% chlorhexidine and 40% doxycycline for treatment of chronic periodontal pockets; Ozcan G et al.; A study was carried out to compare the effects of subgingival applications of resorbable hydroxypropylmethylcellulose (HPMC) membranes containing 20% chlorhexidine (CHx) and 40% doxycycline (DOXY) placed subgingivally in periodontal pockets greater than 5 mm in depth . Each of 11 patients had at least four pockets . HPMC strips containing CHx and DOXY were inserted into each pocket twice a week for 6 w . One pocket was kept as a control and the other received subgingival scaling and root planing at 0, 1, 3 and 6 w . The microbial flora of 44 pockets from the 11 patients was examined using dark-field microscopy at the baseline and at 1, 3, 6 and 10 w . Clinical parameters including probing depth, crevicular fluid flow, bleeding on probing and gingival shrinkage were also recorded . The CHx and DOXY-administered or root-planed pockets showed marked reduction of both pocket depth and the number of motile organisms . Less bleeding was also observed in CHx and DOXY-inserted pockets.

Kansenshogaku Zasshi, 1994 Sep, 68(9), 1093 - 104
{Phase III clinical trial of KRN8601 (rhG-CSF) for neutropenia in patients with human immunodeficiency virus infection}; Kimura S et al.; The efficacy of KRN8601 for neutropenia associated with HIV infection was evaluated in 24 patients . KRN8601 was infused intravenously at a dosage of 200 micrograms/m2 for 14 consecutive days . Neutrophil counts recovered in 19 (90.5%) out of 21 evaluable patients by KRN8601 treatment . The concomitant myelosuppressive agents for the treatment of HIV infection and complications could be continued without dose reduction in 15 (88.2%) out of 17 patients . The clinical improvement was observed in 66.7% (12/18) of patients who were treated with anti-microbial agents for opportunistic infections which indicates that KRN8601 shows an additive effect on infections when it was given with anti-microbial agents . Adverse events and abnormal laboratory findings were observed in 3 and 7 patients, respectively, and they were reversible and tolerable . This study demonstrated that KRN8601 improved neutropenia with HIV infection, made possible to continue the full dose of myelosuppressive treatments and have additive effect on the treatment of secondary infections.

Eur J Pediatr, 1994 Sep, 153(9), 656 - 8
Haemolytic anaemia in association with Escherichia coli O157 infection in two sisters; Pennings CM et al.; Two sisters, 2 and 5 years of age, suffered from acute haemolytic anaemia occurring after gastroenteritis with Escherichia coli O157 . One patient developed clinical signs of severe and acute intravascular haemolysis and sepsis . She received transfusion and antibiotic therapy . The second patient presented with mild to moderate haemolytic symptoms only . None of them developed renal impairment . In serum of both children, elevated titres of short-lived agglutinins were demonstrated in the indirect haemagglutination assay consisting of sheep erythrocytes coated with lipopolysaccharide from E . coli O157 . By immunoblot analysis IgM antibodies against the O157 lipopolysaccharide were demonstrated in the acute phase sera but not in follow up sera taken 2 months after disease . On erythrocyte membranes, adsorption of microbial antigens was detected by use of a pool-immunoglobulin fluorescence test . The immunological status of both patients was normal . Complete recovery from haemolytic disease was observed without further therapy . Microbial antigens attached to the cell surface were assumed to be the pathophysiological cause of E . coli O157 associated haemolytic anaemia in two siblings.

Chemosphere, 1994 Sep, 29(6), 1349 - 56
Degradation of tri-n-butyltin in Ise Bay sediment; Yonezawa Y et al.; The vertical distribution patterns of the transformation products of tri-n-butyltin (TBT) in sediment cores collected from 6 sites in Ise Bay, Japan indicated that TBT was transformed by two pathways: methylation and debutylation . Anaerobic incubation of sediment spiked with TBT showed that the methylation was mainly supported by sulfate reducing activity and debutylation was mainly supported by nitrate reducing activity . These results showed that contribution of the two transformation reactions of TBT varied according to the dominant microbial activities in the sediment . The two types of vertical distribution of butyltins observed in the sediment cores appear to be the result of different dominant microbial activity in the sediment.

FEMS Microbiol Rev, 1994 Sep, 15(1), 29 - 63
Bacterial lipases; Jaeger KE et al.; Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids . They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium . A characteristic property of lipases is called interfacial activation, meaning a sharp increase in lipase activity observed when the substrate starts to form an emulsion, thereby presenting to the enzyme an interfacial area . As a consequence, the kinetics of a lipase reaction do not follow the classical Michaelis-Menten model . With only a few exceptions, bacterial lipases are able to completely hydrolyze a triacylglycerol substrate although a certain preference for primary ester bonds has been observed . Numerous lipase assay methods are available using coloured or fluorescent substrates which allow spectroscopic and fluorimetric detection of lipase activity . Another important assay is based on titration of fatty acids released from the substrate . Newly developed methods allow to exactly determine lipase activity via controlled surface pressure or by means of a computer-controlled oil drop tensiometer . The synthesis and secretion of lipases by bacteria is influenced by a variety of environmental factors like ions, carbon sources, or presence of non-metabolizable polysaccharides . The secretion pathway is known for Pseudomonas lipases with P . aeruginosa lipase using a two-step mechanism and P . fluorescens lipase using a one-step mechanism . Additionally, some Pseudomonas lipases need specific chaperone-like proteins assisting their correct folding in the periplasm . These lipase-specific foldases (Lif-proteins) which show a high degree of amino acid sequence homology among different Pseudomonas species are coded for by genes located immediately downstream the lipase structural genes . A comparison of different bacterial lipases on the basis of primary structure revealed only very limited sequence homology . However, determination of the three-dimensional structure of the P . glumae lipase indicated that at least some of the bacterial lipases will presumably reveal a conserved folding pattern called the alpha/beta-hydrolase fold, which has been described for other microbial and human lipases . The catalytic site of lipases is buried inside the protein and contains a serine-protease-like catalytic triad consisting of the amino acids serine, histidine, and aspartate (or glutamate) . The Ser-residue is located in a strictly conserved beta-epsilon Ser-alpha motif . The active site is covered by a lid-like alpha-helical structure which moves away upon contact of the lipase with its substrate, thereby exposing hydrophobic residues at the protein's surface mediating the contact between protein and substrate.(ABSTRACT TRUNCATED AT 400 WORDS)

J Am Dent Assoc, 1994 Sep, 125(9), 1205 - 11
Assessing microbial contamination in clean water dental units and compliance with disinfection protocol; Williams HN et al.; With proper maintenance, clean water dental units should provide water that contains few, if any, bacteria . In this evaluation of 24 units, all but one were found to be contaminated . Further investigation revealed a breakdown in the proper disinfection and maintenance of these clean water units . Results of the study and a disinfection protocol are provided.

J Am Dent Assoc, 1994 Sep, 125(9), 1189 - 97
Practical infection control for the 1990s: applying science to government regulations; Molinari JA; Optimal infection control is achieved more by understanding infectious diseases than by meeting federal and state regulations . A basic review of microbial transmission, aseptic technique and universal precautions provides a better understanding of the rationale behind recommended procedures.

J Antibiot (Tokyo), 1994 Sep, 47(9), 969 - 75
Microbial metabolites with tipA promoter inducing activity . II . Geninthiocin, a novel thiopeptide produced by Streptomyces sp . DD84; Yun BS et al.; Geninthiocin was isolated from the mycelium of Streptomyces sp . DD84 as a tipA promoter inducing substance . Based on various NMR studies, its structure was established as a thiopeptide with oxazole and thiazole moieties, and several unusual amino acids.

Bull Math Biol, 1994 Sep, 56(5), 923 - 43
A differential geometric treatment of protein structure comparison; Ding DF et al.; The technique of model-building a protein of known sequence but unknown tertiary structure from the structures of homologous proteins is probably so far the most reliable means of mapping from primary to tertiary structure . A key step towards the realization of the aim is to develop ways of aligning three-dimensional structures of homologous proteins, thereby deriving the rules useful for protein modelling . We have developed a generalized differential-geometric representation of protein local conformation for use in a protein comparison program which aligns protein sequences on the basis of their sequence and conformational knowledge . Because the differential-geometric distance measure between local conformations is independent of the coordinate frame and remains chirality information, the comparison program is easily implemented, relatively rational and reasonably fast . The utility of this program for aligning closely and distantly related homologous proteins is demonstrated by multiple alignment of globins, serine proteinases and aspartic proteinase domains . Particularly, the method has reached the rational alignment between the mammalian and microbial serine proteinases as compared with many published alignment programs.

Plant Foods Hum Nutr, 1994 Sep, 46(2), 167 - 73
Production and storage stability of non-alcoholic pawpaw beverage powder; Mugula JK et al.; Powder for instant non-alcoholic pawpaw beverage formulation was manufactured by traditional sundrying and controlled ovendrying . The reconstituted beverage was organoleptically acceptable . The effect of sundrying on mats and ovendrying on product quality was investigated . Sundrying resulted into losses of vitamins A and C, and total sugar by 97, 98 and 87 percent; while, oven drying losses were 92, 98 and 87 percent, respectively . Nutrient losses during storage in transparent polythene bags at ambient conditions reached 98, 98 and 82 percent in sundried samples and; 87, 99 and 67 percent in ovendried samples respectively . The moisture content of sundried and oven dried samples increased by 14 percent during storage . The increase in microbial load during storage was higher in sundried samples.

Plasmid, 1994 Sep, 32(2), 101 - 30
Mathematics of microbial plasmid instability and subsequent differential growth of plasmid-free and plasmid-containing cells, relevant to the analysis of experimental colony number data; Proctor GN; Differential growth of plasmid-containing and plasmid-free microbial cells occurs in many and probably most plasmid systems . Misinterpretation of differential growth as replicational, recombinational, or segregational stability or instability can unfortunately result in grossly erroneous conclusions about replication, recombination, or segregation in plasmid model systems for studies of such phenomena . The differential growth rate should ideally be measured every time that the rate of loss due to instability per se is measured . Unfortunately, the possibility of differential growth has been ignored in most plasmid model systems, since the mathematics of instability and differential growth has not usually been dealt with in ways that are intuitively understandable to experimental microbiologists . Nevertheless, rapid diagnosis of differential growth, and accurate estimation of differential growth rate and rate of loss due to instability per se, can be done by analysis of colony number data using only the relatively simple mathematics described in this review . This review is intended for experimental microbiologists rather than for theoretical population geneticists or for pure mathematicians . However, the same mathematics described in this review is also applicable to certain simple model systems for plasmid ecology or evolution in natural or clinical environments.

Semin Respir Infect, 1994 Sep, 9(3), 192 - 8
Empirical therapy of community-acquired pneumonia; Niederman MS; An empiric approach to the therapy of community-acquired pneumonia (CAP) is needed because of the limitations of traditional approaches to antibiotic selection . The use of sputum Gram's stain and culture tests to guide initial therapy is potentially inaccurate and of limited use . Clinical syndromes cannot be reliably used to predict microbial pathogens, primarily because host, as well as bacterial factors, contribute to the presence of specific clinical signs and symptoms . The routine use of extensive diagnostic testing on all patients with CAP is expensive and of limited clinical usefulness . An empirical approach is presented that is based on an assessment of three factors that can help to predict the likely etiologic pathogens and thus guide initial therapy . These factors are the place of therapy, the presence of advanced age and/or comorbidity, and the severity of illness on initial clinical presentation . When these factors are used to guide empirical therapy, it is important to recognize and appropriately evaluate the nonresponding patient, and it is in this setting that an extensive diagnostic evaluation may be most useful.

Semin Respir Infect, 1994 Sep, 9(3), 130 - 9
The pathology of community-acquired pneumonia; Barnes P; A good understanding of pathologic processes facilitates clinical approaches to the diagnosis of respiratory disorders . The pathology of community-acquired pneumonia is reviewed . The gross appearance and microscopic features of bronchopneumonia, lobar pneumonia, interstitial pneumonia, and mixed patterns are compared . Next, features of lung injury incited by specific microbial agents are discussed . Specific histological clues to diagnosis of the causative agent are highlighted where applicable . Special techniques are available to aid the pathologist in diagnosis of specific microbial agents in biopsy materials . The benefits and pitfalls of using immunohistochemical stains and molecular biologic techniques, such as in situ hybridization and the polymerase chain reaction are briefly presented . Finally, the methods by which material for study are obtained, (open lung biopsy, fine needle aspiration, and bronchoalveolar lavage), are discussed with respect to advantages and limitations.

Comput Appl Biosci, 1994 Sep, 10(5), 477 - 88
BIOESTIM: software for automatic design of estimators in bioprocess engineering; Farza M et al.; This paper describes BIOESTIM, a software package devoted to on-line estimation in bioprocess engineering . BIOESTIM enables bioengineers automatically to design state and parameter estimators from a minimal knowledge of the process kinetics . Such estimators allow development of software sensors capable of coping with the lack of reliable instrumentation suited to real-time monitoring . The estimator building procedure through BIOESTIM starts up from a dynamical material balance model of the bioprocess . This model, supplied by the user, is next completed by other information with no requirement for numerical values: the user has only to specify available measurements, coupled reactions and the known yield coefficients . On the base of this knowledge, BIOESTIM proceeds to symbolic algebraic manipulations on the model in order to study estimation possibilities and check identifiability of yield coefficients . When the design of an estimator is possible, the corresponding equations are automatically generated . Moreover, these estimators are stored in a user-specified file which is automatically interfaced with a specialized simulation software including data treatment and numerical integration packages . Thus, the user can simulate the estimator performances under various operational conditions using available experimental measurements . A typical example dealing with microbial growth and biosynthesis reactions is given in order to illustrate the main functional capabilities of BIOESTIM . BIOESTIM has been designed and written in a modular fashion . The module dealing with estimators design makes use of symbolic computation; it is written in Mathematica and runs on every computer on which this language is available.

Am J Reprod Immunol, 1994 Sep, 32(2), 108 - 13
Macrophage inflammatory protein-1 alpha in term and preterm parturition: effect of microbial invasion of the amniotic cavity; Romero R et al.; PROBLEM: This study was conducted to determine whether: (1) gestational age, parturition, and microbial invasion of the amniotic cavity (MIAC) are associated with changes in amniotic fluid concentrations of immunoreactive macrophage inflammatory protein-1 alpha; (2) amniotic fluid concentrations of macrophage inflammatory protein-1 alpha are correlated with the white blood cell count and the concentrations of interleukin-8 in amniotic fluid . METHOD: Amniotic fluid was retrieved by amniocentesis from 126 patients; 54 women with preterm labor and intact membranes (no MIAC-delivery at term, N = 21; no MIAC-preterm delivery, N = 16; MIAC-preterm delivery, N = 17); 62 patients at term (no labor, N = 19; labor-no MIAC, N = 20; labor-MIAC, N = 23); and 10 patients in the midtrimester of pregnancy . Amniotic fluid was cultured for aerobic, anaerobic and Mycoplasma species . Determinations of amniotic fluid macrophage inflammatory protein-1 alpha and interleukin-8 were performed with immunoassays validated for amniotic fluid (sensitivity: 14.2 pg/ml and 0.3 ng/ml, respectively) . Kruskal-Wallis analysis of variance (ANOVA) for censored data, Mann-Whitney U test and Spearman's rank correlation were performed for analysis . RESULTS: 1) Amniotic fluid macrophage inflammatory protein-1 alpha was present in only 31.0% (9/29) of patients not in labor (midtrimester and term) . 2) Patients with preterm labor and MIAC had higher amniotic fluid concentrations of macrophage inflammatory protein-1 alpha than those without MIAC (no MIAC-delivery at term: median 0.0 pg/ml, range 0.0-221.2; no MIAC-preterm delivery: median 37.4 pg/ml, range 0.0-494.6; MIAC-preterm delivery: median 7171.0 pg/ml, range 402.5-37994.0; P < 0.00001) . 3) Among patients at term, MIAC was associated with higher concentrations of amniotic fluid macrophage inflammatory protein-1 alpha than patients without MIAC (no labor: median 0.0 pg/ml, range 0.0-25.6; labor-no MIAC: median 16.7 pg/ml, range 0.0-161.6; labor-MIAC: median 103.8 pg/ml, range 0.0-4349.0, P < 0.001) . 4) Among patients in preterm labor, a strong correlation was found between amniotic fluid concentrations of macrophage inflammatory protein-1 alpha and interleukin-8 (r = 0.9, P < 0.00001) and between amniotic fluid macrophage inflammatory protein-1 alpha concentrations and amniotic fluid white blood cell count (r = 0.6, P < 0.0001) . CONCLUSIONS: (1) Macrophage inflammatory protein-1 alpha is undetectable in most amniotic fluid samples from patients in the midtrimester of pregnancy and at term not in labor . (2) Microbial invasion of the amniotic cavity is associated with increased concentrations of immunoreactive amniotic fluid macrophage inflammatory protein-1 alpha in both term and preterm gestations . (3) Amniotic fluid macrophage inflammatory protein-1 alpha concentrations significantly correlate with interleukin-8 levels and white blood cell count in amniotic fluid . Our data strongly suggest a role for macrophage inflammatory protein-1 alpha in the mechanisms responsible for the recruitment of leukocytes into the amniotic cavity during the course of intrauterine infection.

Eur J Obstet Gynecol Reprod Biol, 1994 Sep, 56(3), 153 - 60
Cytokine levels in amniotic fluid and inflammatory changes in the placenta from normal deliveries at term; Halgunset J et al.; Cytokine levels in amniotic fluid have been shown to increase towards term in normal pregnancies, and may play a regulatory role in parturition by stimulating the local production of prostaglandins . The work reported in the present paper was conducted in order to test the hypothesis that the increased cytokine levels may be induced by a subclinical inflammatory reaction in intrauterine tissues . The concentrations of tumor necrosis factor (TNF), interleukin 1 (IL-1), interleukin 2 (IL-2) and interleukin 6 (IL-6) were determined in samples of amniotic fluid from 38 women in delivery at term, after a clinically normal pregnancy . In 33 of the cases, tissue material was available for histological examination . In these, the extent of inflammatory cell infiltration was assessed in the fetal membranes, placenta and umbilical cord . A close interrelation was observed between the levels of the mediators typically released during inflammatory processes (TNF, IL-1, IL-6) . Frank chorioamnionitis was not found in any of the histological specimens, although most placentae showed varying degrees of granulocyte infiltration in the fibrin layer under the chorion, sometimes also in the chorionic membrane . The degree of such leukocytic infiltration correlated positively with the levels of TNF, IL-1 and IL-6 . These findings lend support to the hypothesis that a low-level inflammatory process may be a normal occurrence in the term placenta, and that this process may induce the production of cytokines, which, in turn, may play a role in the regulation of parturition . Such inflammation could be due to exposure of the fetal membranes to microbial material from the vagina, as the cervix dilates towards term.

Aviat Space Environ Med, 1994 Sep, 65(9), 851 - 7
Volatile organic contaminants found in the habitable environment of the Space Shuttle: STS-26 to STS-55; James JT et al.; The health and performance of spacecraft crews can be adversely affected by contaminants present in the respirable air . Contaminants originate from hardware offgassing, crew and microbial metabolism, use of utility chemicals, leakage from fluid systems and payload experiments, and from electrical overheating . The quality of Shuttle air is measured by collecting contaminants in evacuated cylinders or on sorbent resin for later ground-based analysis by gas chromatography (GC) and GC mass spectrometry (MS) . The results of those analyses are presented for 28 missions, including 5 Spacelabs which were flown in the payload bay of the Shuttle . The major contaminants were relatively nontoxic alcohols (ethanol, isopropanol), ketones (acetone, diacetone alcohol), alkanes, halocarbons (Halon 1301, Freon 113), and siloxanes . Occasionally, more toxic contaminants, such as methanol, acetaldehyde, and tetrachloroethene, were present at low concentrations (below 1 mg/m3) . The contaminant concentrations measured in spacecraft air were compared to spacecraft maximum allowable concentrations (SMAC's) which are set to protect the crew from adverse health effects or performance decrements . Aggregate toxicity assessments (T values) of the contaminants present during each mission, calculated by summing the ratios of measured concentrations to each contaminant's SMAC, showed that air quality consistent met the criterion that the T value be less than 1.

JPEN J Parenter Enteral Nutr, 1994 Sep-Oct, 18(5), 453 - 7
Evaluation of "closed" vs "open" systems for the delivery of peptide-based enteral diets; Wagner DR et al.; BACKGROUND: The study was designed to quantitate factors such as preparation time, waste, and contamination associated with three different feeding systems for peptide-based diets and to determine appropriate hang times . METHODS: Intensive care unit patients were randomized to receive a peptide-based diet in 1500-mL prefilled, sterile closed-system containers (CS) infused more than 24 hours, as open systems decanted from cans (OS-Can), or as open systems mixed from powder (OS-Powder) . Open-system groups were provided a 12-hour supply twice daily in commercially clean 1-L bags with preattached sets . Samples were taken for culture during preparation and after infusion . Preparation time, initial and final microbial concentrations, and total waste were quantified . RESULTS: Preparation time was significantly shorter for CS than for OS-Can or for OS-Powder (2 minutes vs 7.5 minutes vs 13.0 minutes) . Initially, 100% of the OS-Powder and 30% of the OS-Can bags were contaminated, with significant contamination exceeding 10(4) colony-forming units/mL in 40% and in 5% of the bags, respectively . On final culture, significant contamination occurred in only 2% of the CS bags compared with 83% of the OS-Powder and 60% of the OS-Can bags . Average time from potential initial contamination to final culture in CS was 49.9 hours vs 38.8 hours for OS-Can and 32 hours for OS-Powder . Total waste was greater in CS than in OS-Can or OS-Powder but could be eliminated by extending allowable hang times . CONCLUSIONS: Nonvented closed-delivery containers may be safely infused for up to 48 hours . They are associated with reduced labor and contamination.

J Refract Corneal Surg, 1994 Sep-Oct, 10(5), 545 - 9
Retrospective comparison of simultaneous and non-simultaneous bilateral radial keratotomy; Moreira H et al.; PURPOSE: Many radial keratotomy surgeons advocate bilateral simultaneous surgery, in which there is an inherent, although rare, risk of bilateral sight-threatening complications such as microbial keratitis . This study was designed to evaluate the refractive outcomes of simultaneous and non-simultaneous radial keratotomy performed by a single surgeon . METHODS: We retrospectively compared the results of radial keratotomy performed simultaneously (both eyes operated on the same day, 20 patients) versus non-simultaneously (right and left eyes operated on different days, 71 patients) by a single surgeon . Both eyes had the same surgical procedure, including clear zone diameter and number of incisions . RESULTS: The refractive results of bilateral simultaneous and non-simultaneous surgery were largely equivalent for all parameters analyzed except one . The variability of the difference in postoperative refractive error between right and left eyes was less for those patients undergoing simultaneous surgery (p = .0008) . CONCLUSION: Our data suggest that performing radial keratotomy as a bilateral simultaneous procedure increases the symmetry of the refractive effect . In view of recent reports of sight-threatening risks such as bilateral microbial keratitis following bilateral keratotomy, however, the potential risks and benefits of bilateral surgery should be carefully considered before operating on both eyes on the same day.

Immunol Today, 1994 Sep, 15(9), 418 - 22
MHC class II signaling in B-cell activation; Scholl PR et al.; The cognate interaction between T cells and antigen-presenting cells (APCs), mediated by major histocompatibility complex (MHC) class II molecules, results in the delivery of activation signals to the APC . These signals contribute to the expression of co-stimulatory activity by APCs and have important consequences for cell effector function . MHC class II molecules also serve as receptors for B-cell stimulation by microbial superantigens . In this review, Paul Scholl and Raif Geha discuss recent advances in our understanding of mechanisms of MHC class II signaling and analyse their role in human B-cell activation.

Proc Natl Acad Sci U S A, 1994 Aug 16, 91(17), 8175 - 9
Nonpeptide ligands for human gamma delta T cells; Tanaka Y et al.; gamma delta T cells respond to a variety of microbial pathogens and transformed cells . Their limited receptor repertoire and activation by mycobacterial antigens resistant to proteases suggest that they may recognize nonpeptide antigens . We have tested a variety of nonpeptide molecules for stimulation of human gamma delta T cells . Synthetic alkyl phosphates, particularly monoethyl phosphate (MEP), selectively activated gamma delta T cells and stimulated their proliferation in vitro . All gamma delta T cells stimulated by MEP expressed V gamma 2/V delta 2 receptors . The purified natural ligand of mycobacteria is chemically similar to, though distinct from, MEP and contains a phosphate residue that is critical for biological activity . Recognition and expansion of a specific T-cell receptor-bearing population to non-peptide ligands is unprecedented among T cells . We suggest that MEP mimics small natural ligands capable of expanding one subset of gamma delta T cells and that this recognition of nonpeptide antigens may play an important role in human immunity to pathogens.

Eur J Biochem, 1994 Aug 15, 224(1), 125 - 34
Purification and characterization of active and stable recombinant plasminogen-activator inhibitor accumulated at high levels in Escherichia coli; Sancho E et al.; Plasminogen-activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of tissue-type plasminogen activator, is an unusual member of the serine protease inhibitor (serpin) superfamily in that it spontaneously converts to a latent form lacking activity . This latent form can be reactivated by denaturation and refolding, but the activation is usually incomplete and often leads to aggregation of the protein . In this study we have developed a high-level expression system that leads to the accumulation of PAI-1 at 30-50% total microbial protein . We have developed a single-step purification protocol which can be completed in a few hours, yielding approximately 20 mg purified recombinant PAI-1/litre culture . The purified PAI-1 was 80-100% active and was stable upon incubation at 37 degrees C with a half-life of approximately 48 h . At 20 degrees C, PAI-1 activity was stable for a week and at 4 degrees C it retained its activity completely for up to two months . Freezing caused significant loss of activity . The stability of PAI-1 activity was found to be dependent on pH and ionic strength, being most stable at pH 5.6 and at an ionic strength of 1 M salt . We show that by a combination of high-level expression and rapid purification under optimum conditions, it is possible to produce active and stable PAI-1 in high yield.

Schweiz Rundsch Med Prax, 1994 Aug 9, 83(32), 873 - 6
{Sense and nonsense in the treatment of exocrine pancreatic insufficiency}; Mossner J; Application of pancreatic digestive enzymes is indicated in cases of a quantitatively decreased exogenous secretion or an asynchronous secretion of enzymes with regard to the duodenal passage of chyme . A clear indication for therapy is a proven steatorrhea, a relative indication loss weight of and/or uncharacteristic abdominal discomfort in patients with proven pancreatic disease, i.e . chronic pancreatitis . Uncharacteristic abdominal discomfort alone, which is regarded as a consequence of 'maldigestion' without proven pancreatic disease, is not an indication for therapy . To prevent a destruction of exogenously applied lipase by gastric acid and to enable a synchronous gastroduodenal passage of the enzymes together with food, acid-protected micropellets or -tablets with an ideal diameter around 1.4 mm containing high amounts of lipase are requested . In cases of anacidity i.e . gastrectomy or type-A gastritis, lipase rich 'conventional' enzymes applied as granulate are sufficient . Combinations (pancreatic enzymes with bile acids) or fungal lipases have either more side effects (diarrhea) or are less efficient when compared to porcine enzymes . Acid-resistant microbial lipases may be useful in the near future . Application of pure proteases or pancreatic enzymes with high concentrations of proteases as treatment of pain in chronic pancreatitis ('negative feedback regulation') are a rather expensive form of treatment when compared to analgetics and are probably ineffective.

J Theor Biol, 1994 Aug 7, 169(3), 275 - 87
Host-host-pathogen models and microbial pest control: the effect of host self regulation; Begon M et al.; A model has been investigated of the dynamics of the interaction between two hosts that are both attacked by a common pathogen with free-living infective stages, where the hosts are also subject to self-regulation . If either host interacted with the pathogen alone, two types of dynamics would be possible: an uninfected state where the host settles at its carrying capacity, and an infected state where the host settles at, or cycles around, a density lower than the carrying capacity . The three possible combination of two hosts have been investigated: uninfected-uninfected (both hosts uninfected if alone with the pathogen), infected-uninfected and infected-infected . A range of dynamics is generated, depending on parameter values, including infected co-existence of the two hosts (arrived at by a variety of routes), uninfected co-existence of the two hosts, exclusion of one host by the other which remains in an infected state, and a number of outcomes contingent on the initial densities in the system . Free-living infective stages make uninfected co-existence more likely and introduce additional contingency into the dynamics . The implications for microbial pest control are into the dynamics . The implications for microbial pest control are markedly different from those derived from related models without host self-regulation . There appears to be little chance of a non-target host undermining pest control, relatively little chance of the non-target enhancing pest control and a small but non-negligible threat to non-targets when parameter values are appropriate . The application of the results is commended but great caution is urged.

Transfus Sci, 1994 Sep, 15(3), 207 - 20
Molecular and biological actions of cyclosporin A and FK506 on T cell development and function; Hollander GA et al.; The microbial products cyclosporin A (CsA) and FK506 are potent immunosuppressive agents in experimental and clinical transplantation . Binding of both drugs to intracellular immunophilins results in the inhibition of calcineurin activity and the prevention of interleukin-2 gene transcription and, thus, in the inhibition of T cell receptor-dependent T cell activation . CsA and FK506 also have a profound effect on the structure and function of the thymus with disruption of positive and negative selection of T cells . These influences on thymic microenvironment and T cell ontogeny disrupt the induction or maintenance of self-tolerance (or both) and are thus of relevance to clinical transplantation immunology.

Proc Natl Acad Sci U S A, 1994 Aug 2, 91(16), 7440 - 4
Gene for an extracellular matrix receptor protein from Pneumocystis carinii; Narasimhan S et al.; An initial and crucial step in the establishment of many microbial infections is the attachment of the pathogen to the host cells . Thus, adherence of Pneumocystis carinii (Pc) to type I pneumocytes is believed to be important in the induction of Pc pneumonia . Little is known about the nature of the attachment of Pc to type I cells, although extracellular matrix (ECM) proteins, such as fibronectin and laminin, have been implicated in the process . We report here the isolation of a Pc gene encoding a receptor protein that binds both fibronectin and laminin in vitro . A cDNA clone encoding the Pc ECM receptor was isolated from a Pc cDNA library and identified on the basis of sequence homology to the human colon carcinoma laminin receptor . Southern blot analysis of Pc genomic DNA confirmed that the cDNA was of Pc origin . Northern blot analysis of Pc total RNA showed a predominant mRNA of approximately 1400 nucleotides that hybridized to the ECM receptor gene . The ECM receptor predicted from the cDNA sequence is 295 amino acid residues long, with a molecular mass of 32.8 kDa . The C-terminal third of the polypeptide is highly negatively charged, whereas the N-terminal two-thirds contains hydrophobic segments that may play a role in membrane association . Sequence analysis and alignment of the N terminus with the laminin receptor cDNA sequence of human colon carcinoma support the conclusion that the Pc ECM receptor cDNA clone is a full-length clone . A Western blot of the overexpressed ECM receptor protein bound both laminin and fibronectin in vitro . Antibodies raised to the overexpressed receptor protein interacted with a 33-kDa protein in total Pc cell lysates . These findings raise the possibility that the Pc ECM receptor protein may mediate the organism's attachment to type I pneumocytes and, thus, may play a crucial role in Pc pathogenesis.

Appl Environ Microbiol, 1994 Aug, 60(8), 2677 - 83
Accumulation of selenium in a model freshwater microbial food web; Sanders RW et al.; The transfer of selenium between bacteria and the ciliated protozoan, Paramecium putrinum, was examined in laboratory cultures . The population growth of the ciliate was not inhibited in the presence of the highest concentrations of dissolved selenite or selenate tested (10(3) micrograms liter-1) . Experiments with radioactive 75selenite or 75selenate indicated that accumulation of selenium by ciliates through time was low when feeding and metabolism were reduced by incubating at 0 degrees C . However, selenium accumulated in ciliate biomass during incubation with dissolved 75Se and bacteria at 24 degrees C and also when bacteria prelabeled with 75Se were offered as food in the absence of dissolved selenium . When 75Se-labeled bacterial food was diluted by the addition of nonradioactive bacteria, the amount of selenite and selenate in ciliates decreased over time, indicating depuration by the ciliates . In longer-term (> 5-day) fed-batch incubations with 75selenite-labeled bacteria, the selenium concentration in ciliates equilibrated at approximately 1.4 micrograms of Se g (dry weight)-1 . The selenium content of ciliates was similar to that of their bacterial food on a dry-weight basis . These data indicate that selenium uptake by this ciliate occurred primarily during feeding and that biomagnification of selenium did not occur in this simple food chain.

Compendium . 1994 Aug;15(8):958, 960, 962 passim; quiz 972.
Assessing bacterial risk factors for periodontitis and peri-implantitis: using evidence to enhance outcomes; Newman MG et al.; This article discusses the use of microbial diagnostics and their relationship to the treatment of periodontal and peri-implant disease . Clinical and microbiologic characteristics are described to help the practitioner recognize patients with periodontitis and peri-implant infections . By using available information (evidence) to guide the choice of therapeutic intervention, the clinician can enhance the outcomes resulting from therapy.

Genetics, 1994 Aug, 137(4), 903 - 17
Microbial evolution in a simple unstructured environment: genetic differentiation in Escherichia coli; Rosenzweig RF et al.; Populations of Escherichia coli initiated with a single clone and maintained for long periods in glucose-limited continuous culture, become polymorphic . In one population, three clones were isolated and by means of reconstruction experiments were shown to be maintained in stable polymorphism, although they exhibited substantial differences in maximum specific growth rates and in glucose uptake kinetics . Analysis of these three clones revealed that their stable coexistence could be explained by differential patterns of the secretion and uptake of two alternative metabolites acetate and glycerol . Regulatory (constitutive and null) mutations in acetyl-coenzyme A synthetase accounted for different patterns of acetate secretion and uptake seen . Altered patterns in glycerol uptake are most likely explained by mutations which result in quantitative differences in the induction of the glycerol regulon and/or structural changes in glycerol kinase that reduce allosteric inhibition by effector molecules associated with glycolysis . The evolution of resource partitioning, and consequent polymorphisms which arise may illustrate incipient processes of speciation in asexual organisms.

Trends Microbiol, 1994 Aug, 2(8), 271 - 7
Microbial sialidases: does bigger always mean better?
Vimr ER.
Sialidases are a superfamily of N-acylneuraminate-releasing (sialic-acid-releasing) exoglycosidases found mainly in higher eukaryotes and in some, mostly pathogenic, viruses, bacteria and protozoans . The functions of sialidases are poorly understood and, until recently, their biochemical and evolutionary relationships were unclear . A comparative approach has demonstrated the remarkable similarities and differences between nonviral sialidases, and is providing clues about their functions.

Nurse Pract, 1994 Aug, 19(8), 53 - 60
The prevention and diagnosis of infective endocarditis . The primary care provider's role; Matthews D; Infective endocarditis, a microbial infection of the endocardium, is a complex multifaceted disease that may affect any organ system . Despite advances in diagnostic technology and treatment, overall mortality rates from infective endocarditis remain between 15-45%, and as high as 40-70% among the elderly . Explanations for the persistence of high mortality rates have focused on delays or errors in diagnosis . The classic diagnostic triad of fever, cardiac murmur, and positive blood cultures are not always present . Elderly patients often have more non-specific symptoms than do younger patients . Infective endocarditis should be considered in conditions dominated by the insidious onset of congestive heart failure, acute mental status or neurological changes, or the acute onset of arthralgias or myalgias . This article reviews the pathogenesis, epidemiology and etiology, risk factors, and clinical presentations of infective endocarditis, as well as current recommendations for antibiotic prophylaxis.

Kidney Int, 1994 Aug, 46(2), 443 - 54
Immunohistochemical studies of the peritoneal membrane and infiltrating cells in normal subjects and in patients on CAPD; Suassuna JH et al.; We performed immunohistochemical studies on biopsies of the parietal peritoneal membrane of 33 subjects to investigate whether other cell populations, in addition to mononuclear cells free in the dialysate, might participate in the defense of the peritoneum against microbial invasion during CAPD . Leukocytes were found to concentrate in two areas: a submesothelial layer composed of elongated macrophages displaying activation and maturation markers, and perivascular, less mature macrophages closely associated with T cells and HLA-DR, ICAM-1 and VCAM-1 expressing endothelial cells . Normal mesothelial cells were found to express constitutively the transferrin receptor and the adhesion molecules ICAM-1 and VCAM-1 but not ELAM-1 . There were no major differences between normal and uremic subjects, while peritoneal dialysis patients exhibited minor derangements of the submesothelial layer and slight up-regulation of the expression of HLA-DR on endothelial cells . Peritonitis was associated with increased submesothelial cellularity and, particularly, perivascular leukocyte infiltration accompanied by increased expression of HLA-DR and adhesion molecules . Besides mononuclear cells free in the dialysate, this study demonstrates the existence of two additional peritoneal membrane leukocyte populations: submesothelial macrophages, and perivascular macrophages and T cells . It also suggests the existence of a fourth population of intracavitary leukocytes adherent to mesothelial cells . Studies are now necessary to evaluate their exact role in the host defence against peritonitis during CAPD.

J Dairy Sci, 1994 Aug, 77(8), 2341 - 56
Effects of fat saturation and source of fiber on site of nutrient digestion and milk production by lactating dairy cows; Pantoja J et al.; Six primiparous cannulated cows were assigned to six treatments in a 6 x 6 Latin square design to evaluate the effects of degree of fat saturation and amount and source of effective fiber on site of nutrient digestion and milk production . Cows were fed for ad libitum intake a control diet with no added fat or diets with 5% added fat from saturated tallow, tallow, or animal-vegetable fat; the diets with animal-vegetable fat had 40% forage, 40% forage plus 20% soyhulls, or 60% forage . Ruminal acetate:propionate was higher when soyhulls replaced forage NDF because of the higher digestibility of soyhulls in the rumen and total tract . Ruminal digestion of NDF was decreased as unsaturation of fat increased . True and apparent efficiencies of bacterial protein synthesis were increased as fat unsaturation increased, probably because of reduced recycling of microbial N in the rumen . The digestibility of fatty acids in the small intestine was higher in cows fed no fat than in those fed fat and was reduced as fat unsaturation decreased, primarily because of the saturated tallow . Dry matter intake was decreased 14% by increased fat unsaturation . All fat supplements depressed milk protein percentage . Production of 4% FCM tended to decrease linearly as unsaturation of fat increased . In diets with 5% added fat, a degree of saturation between saturated tallow and tallow (iodine values of 18 and 62) appears to be optimum for fatty acid digestibility and DMI.

Aust Dent J, 1994 Aug, 39(4), 228 - 32
Physiopathology of primary periodontitis associated with plaque . Microbial and host factors . A review . Part 1; Liebana J et al.; Microbial factors involved in the genesis of periodontitis include colonization, bacterial penetration of the epithelium, multiplication and invasive-destructive capacity . Colonization of the gingival sulcus is related, to a certain extent, to supragingival plaque . Bacterial multiplication is induced by nutrients in the gingival fluid, and nutrients produced by degradative and excretory microbial activity . Invasion and destruction are mediated by exotoxins, structural elements of the bacteria, enzymes, metabolites, polyclonal lymphocyte activity, fibroblastic cytotoxicity, and leukocyte chemotactic inhibition.

Gut, 1994 Aug, 35(8), 1047 - 52
Role of bile in non-specific defence mechanisms of the gut; Kalambaheti T et al.; The effect of depriving the intestine of bile for 48 hours was studied to determine any influence on various parameters of innate immunity in the gastrointestinal tract . Groups of rats were prepared by bile duct cannulation (with or without fluid replacement) or bile duct ligation . Normal and sham operated animals were used for comparing the thickness of the mucus layer and the cells contained therein, enumeration of goblet cells, and measurement of villus size . Histological examination indicated that the intestinal tissues of treated and control rats were similar . Though villus size and numbers of goblet cells were unaffected, a significant reduction occurred in the thickness of the mucus blanket in the duodenal regions of rats deprived of bile, and there were significantly lower numbers of mucus associated enterocytes and lymphocytes, suggesting a lower turnover rate of the epithelium . The balance of the bacterial populations in the caecum and intestine was altered by bile deprivation-increased numbers of coliform organisms were found in both regions . The range of factors, including antibodies and other known constituents, present in bile may contribute to the maintenance of tissue integrity and influence the balance in indigenous bacterial populations in the intestine . Disturbance of the host's biliary system and concomitant effects on the microbial flora may weaken the overall processes of defence in the intestine.

Curr Opin Pediatr, 1994 Aug, 6(4), 383 - 7
Pelvic inflammatory disease in the adolescent; Rome ES; This article reviews new developments in the detection and treatment of pelvic inflammatory disease, including known risk factors, microbial etiologies, treatment standards, and associated morbidity . The use of transvaginal ultrasound and the role of the male partner in infection control is also discussed.

East Afr Med J, 1994 Aug, 71(8), 527 - 30
An aetiological survey of paraplegia in Accra; Nyame PK; Sixty-four cases of non-traumatic paraplegia in Accra, Ghana, were investigated . The commonest cause of paraplegia was tuberculosis (29.69%) . Next were transverse myelitis and the Guillain-Barre syndrome, each accounting for 10.94% of cases . Parasitic causes were not seen in this study . The other important causes are neoplastic conditions (14.07%) and degenerative conditions namely, cervical spondylosis with myelopathy (12.5%), and motor neurone disease (6.25%) . It is concluded that the major causes of non-traumatic paraplegia in Accra are related to non-parasitic microbial infections (51.57%).

J Chemother, 1994 Aug, 6 Suppl 3, 23 - 8
{Do effects of biological response modifiers in vitro correspond to clinical results?}; Graninger W et al.; There has been renewed interest in drug-host defence interaction because of increasing numbers of immunocompromised individuals in whom even a marginal influence on host response may have a beneficial effect on clinical outcome . The immunomodulating activity of several antibiotics has been investigated in the past . Unfortunately most of these studies have focussed on in vitro effects . Many controversies arise from the use of non-standardized techniques . In vivo experiments performed in animals might be far from the clinical situation . The effect of antibiotics on pagocyte function has been studied most intensively . Immunostimulating and depressing activities of antibiotics have been described . The clinical relevance is still controversial, e.g., the intracellular uptake of an antibiotic does not necessarily mean better microbial killing . Synergistic activities have been found with some macrolides and newer cephalosporins, but until now clinical studies in humans are still missing . Not only patients with abnormal host defence mechanisms, but also patients with transient immunosuppression during operations or after burns, could benefit from antibiotics with additional immunomodulating activities . More studies in humans are required before optimal clinical applications can be recommended.

Int J Biol Macromol, 1994 Aug, 16(4), 177 - 80
Solubility and structure of N-carboxymethylchitosan; Muzzarelli RA et al.; N-Carboxymethylchitosan from crab and shrimp chitosans was obtained in water-soluble form by proper selection of the reactant ratio, i.e . using equimolar quantities of glyoxylic acid and amino groups . HPLC determinations of glyoxylic and glycolic acids, in conjunction with NMR analysis, permitted identification of the structure of the product, which is partly N-mono-carboxymethylated (0.3), N,N-dicarboxymethylated (0.3) and N-acetylated depending on the level of deacetylation of the starting chitosan (0.08-0.15) . The preparation can be made successfully even in the presence of large concentrations of glycolic acid . The use of enzymes exerting hydrolysing activity on the high-molecular-weight fractions helps to avoid gel formation during storage and precipitate formation on addition of anti-microbial agents.

Eur J Epidemiol, 1994 Aug, 10(4), 467 - 70
Influenza: global surveillance for epidemic and pandemic variants; Cox NJ et al.; Influenza viruses, unlike other viruses for which vaccines have been developed, undergo rapid and unpredictable antigenic variation in the hemagglutinin (HA), the surface glycoprotein primarily responsible for eliciting neutralizing antibodies during infection . Because of this antigenic variability and its consequences, the World Health Organization (WHO) in 1947 established an international network of collaborating laboratories to monitor the emergence and spread of new epidemic and pandemic strains of influenza . This network now includes three international WHO collaborating centers and over 100 WHO national collaborating laboratories . The primary purpose of this network is to detect, through laboratory surveillance, the emergence and spread of antigenic variants of influenza that may signal a need to update the formulation of the influenza vaccine . This laboratory surveillance network has provided the strains needed to update the vaccine as well as a repository of influenza viruses useful for studying the antigenic and genetic evolution of this virus . Knowledge gained from molecular studies on the evolution of drift variants and on the emergence of pandemic strains has made influenza a useful model for understanding the potential threat of other emerging or reemerging microbial diseases.

Aust N Z J Ophthalmol, 1994 Aug, 22(3), 175 - 81
Sterile ocular inflammatory reactions to monofilament suture material; Sullivan LJ et al.; OBJECTIVE: To report six cases of sterile inflammatory reactions to fine monofilament suture materials, which is exceedingly rare in ophthalmology . METHODS: We report six patients (four underwent penetrating keratoplasty and two underwent cataract surgery) with unusually severe local inflammatory reactions to suture material . RESULTS: Patients developed multiple focal inflammatory infiltrates and corneal oedema related to 10/0 monofilament nylon sutures . Four patients had evidence of either atopy or raised serum IgE and one had an autoimmune disorder (systemic lupus erythematosis) . Onset was four to 11 days in five cases and six weeks in one . Allograft reaction occurred in two of the four corneal grafts, and three grafts failed . One of the cataract patients developed significant against-the-rule astigmatism . Microbial cultures of corneal scrapings, donor corneal rims, and suture material were generally negative . Polymorphonuclear leucocytes were noted on Gram stain in four cases, and cytology of corneal scrapings demonstrated eosinophils in one case . CONCLUSIONS: Sterile inflammatory reactions to monofilament suture material are an uncommon complication of ocular surgery which may lead to corneal graft failure, and which is more common in atopic individuals . Systemic steroid therapy may be required.

Antibiot Khimioter, 1994 Aug, 39(8), 3 - 14
{Role of biocatalysis in the creation and improvement of production of beta-lactam antibiotics in Russia}; Nys PS et al.; The paper presents the results of the studies carried out by the authors within 20 years on development of processes for production of beta-lactam antibiotics with using biocatalysis . The proposed general principles for the development of efficient biocatalytic technologies are discussed in regard to production of the key compounds and synthesis of beta-lactams . The paper includes 4 parts concerned with comparison of the biocatalytic and chemical processes for production of beta-lactam antibiotics, requirements to the quality of the biocatalysts used and criteria for estimation of the efficiency of the stage of the technological biocatalyst production . The criteria provided determination of the optimal biocatalyst for production of the key compounds in the synthesis of beta-lactams . A retrospective analysis of the biocatalytic processes for production of 6-amino-penicillanic acid is presented and the impact of the activity and the form of the biocatalyst on the process efficiency is substantiated . Various schemes of the enzymatic synthesis of beta-lactam antibiotics and the approaches to the improvement of the technological processes including those with the use of immobilized microbial cultures at the stage of the production of the initial biosynthetic antibiotics are described . The prospects for the improvement of the processes for production of drugs with the use of biocatalysis are indicated and the main trends of the research required for the large scale use of the immobilized enzymes, microbial cells, oligo-enzymatic and poly-enzymatic systems in transformation and synthesis of organic compounds are defined.

Nucleic Acids Res, 1994 Jul 25, 22(14), 2731 - 9
A novel fluorogenic substrate for ribonucleases . Synthesis and enzymatic characterization; Zelenko O et al.; The synthesis and enzymatic characterization of DUPAAA, a novel fluorogenic substrate for RNases of the pancreatic type is described . It consists of the dinucleotide uridylyl-3',5'-deoxyadenosine to which a fluorophore, o-aminobenzoic acid, and a quencher, 2,4-dinitroaniline, have been attached by means of phosphodiester linkages . Due to intramolecular quenching the intact substrate displayed very little fluorescence . Cleavage of the phosphodiester bond at the 3'-side of the uridylyl residue by RNase caused a 60-fold increase in fluorescence . This allowed the continuous and highly sensitive monitoring of enzyme activity . The substrate was turned over efficiently by RNases of the pancreatic type, but no cleavage was observed with the microbial RNase T1 . Compared to the dinucleotide substrate UpA, the specificity constant with RNase A, RNase PL3 and RNase U(s) increased 6-, 18-, and 29-fold, respectively . These differences in increased catalytic efficiency most likely reflect differences in the importance of subsites on the enzyme in the binding of elongated substrates . Studies on the interactions of RNase inhibitor with RNase A using DUPAAA as a reporter substrate showed that it was well suited for monitoring this very tight protein-protein interaction using pre-steady-state kinetic methods.

Cancer Lett, 1994 Jul 15, 82(1), 99 - 104
Antitumor activity of bacteria and bacterial products: enhancement of the tumor-protective effect of bacteria by lipoteichoic acid; Keller R et al.; The ability of some microbial agents and/or their products to affect local tumor growth was assessed in the D-12 DA rat ascites tumor model . Various bacteria and bacterial products markedly enhanced tumor resistance when injected i.p . several days before tumor cell challenge . The tumor-protective effect of these compounds was amplified further by lipoteichoic acid (LTA) inoculated i.p . a few days after tumor cell challenge . Under these conditions, the majority of animals did not exhibit progressive tumor growth.

J Virol, 1994 Jul, 68(7), 4673 - 8
A baculovirus gene involved in late gene expression predicts a large polypeptide with a conserved motif of RNA polymerases; Passarelli AL et al.; We have identified and sequenced a novel baculovirus gene, late expression factor eight gene (lef-8), of Autographa californica nuclear polyhedrosis virus that is necessary for efficient expression from late and very late virus gene promoters in a transient expression assay . The predicted gene product, LEF-8, has a molecular mass of 102 kDa and contains a conserved sequence motif, GXKX4HGQ/NKG, found in DNA-directed RNA polymerases throughout the animal, plant, and microbial kingdoms.

Math Biosci, 1994 Jul, 122(1), 25 - 66
Microbial predation in coupled chemostats: a global study of two coupled nonlinear oscillators; Taylor MA et al.; Predator-prey systems in continuously operated chemostats exhibit sustained oscillations over a wide range of operating conditions . When two such chemostats interact through flow exchange, the interplay of the oscillation frequencies gives rise to a wealth of dynamic behavior patterns . Using numerical bifurcation techniques, we perform a detailed computational study of these patterns and the transitions between them as the coupling strength and relative frequencies of the two chemostats vary . We concentrate on certain strong resonance phenomena between the two frequencies as well as their mutual extinction and provide a representative sampling of possible phase portraits for our model system . Our observations corroborate recent mathematical results and case studies of coupled nonlinear chemical oscillators in which regions of mutual extinction as well as the Arnol'd structure for two-parameter families of maps of the plane have been observed . We highlight certain unexpected features of the operating diagram discovered through our computational study and discuss their implication for the dynamic response of the chemostat system.

J AOAC Int, 1994 Jul-Aug, 77(4), 848 - 54
Preparation of milk samples for immunoassay and liquid chromatographic screening using matrix solid-phase dispersion; Barker SA et al.; The use of drugs to maintain the health and maximize the output of dairy cattle has made the monitoring of milk for such agents essential . Screening tests based on immunological, microbial inhibition, and bacterial receptor assays have been developed for the detection of violative levels of therapeutic substances . However, such assays are not infallible, and false positive or negative results can occur when contaminants bind receptors or compete for the binding of the target residues . Such effects may arise from dietary sources, diseases, or other variables . Thus, a violation by such a test is not definitive until further confirmation is obtained . Our laboratory has developed extraction procedures for several drugs used in dairy production . Our method uses matrix solid-phase dispersion (MSPD) to isolate drugs away from contaminants and to eliminate many possible interferences . MSPD can also be used to enhance the specificity of such assays by fractionating various classes of drugs that may cross-react . Similarly, such methods may be used for liquid chromatographic screening and confirmation of a suspect sample.

Am J Trop Med Hyg, 1994 Jul, 51(1), 26 - 35
Twelve messages from enteric infections for science and society; Guerrant RL; Diarrheal diseases hold profound messages as well as opportunities that range from public health to basic science . From the spread of cholera around the world, we are reminded of the global impact of tropical diseases, that disease may provide a litmus test for poverty to drive a sanitary revolution, that disease spread may be worsened by political denial, and that many ecologic and epidemiologic secrets such as interepidemic microbial niches remain poorly understood . Diarrheal diseases other than cholera teach us that heavy disease burdens do not control population growth but are associated with population overgrowth (i.e., improved health is key to controlling the population explosion), the societal impact of diarrhea morbidity may exceed even that of its mortality, that new agents continue to emerge, and that nosocomial diarrhea is an underrecognized threat in our hospitals . Finally, from the laboratory of the developing world also come messages for basic science . Microbial toxins continue to elucidate a new understanding of cell signaling, and mechanisms once thought to be clear (such as that of cholera toxin) now appear much more complex . Traditional remedies hold new pharmacologic secrets, e.g., such as gingko extracts that inhibit platelet-activating factor . Finally, from basic physiology can come widely applicable practical solutions such as oral rehydration therapy and simplified diagnostics for inflammatory diarrhea . Health problems such as diarrheal diseases that plague the disadvantaged are linked to population overgrowth and provide some of the greatest challenges to modern science and the industrialized world.

Surgery, 1994 Jul, 116(1), 76 - 82
Role of intestinal mucus in transepithelial passage of bacteria across the intact ileum in vitro; Albanese CT et al.; BACKGROUND . Although gastrointestinal mucus is one of a number of putative host defense mechanisms that protect the gut barrier against microbial translocation, little experimental data are available to show its role in this process . The present study sought to determine the role of mucus depletion on the transepithelial passage of bacteria across viable segments of rat ileum mounted in Ussing chambers in vitro . METHODS . Intestinal mucus was depleted in 12 rats after injection with pilocarpine (160 mg/kg intraperitoneally) 45 minutes before intestinal harvest . The mucosal surfaces of the perfused gut segments mounted in the Ussing chamber were exposed to 5 x 10(9) CFU/ml Escherichia coli C-25 . Viability was monitored by continuous measurements of the potential difference generated by the membranes . The electrical characteristics were unaltered by pilocarpine pretreatment or exposure to bacteria . RESULTS . Bacterial passage occurred in 100% of pilocarpine membranes as compared with 33.3% in controls (p < 0.05) . Pilocarpine-treated membranes resulted in 19.9 +/- 7.5 mg of retrievable mucus as compared with 28.8 +/- 7.2 mg in controls (p < 0.05) . Light and transmission electron microscopy revealed an intact epithelial surface in all membranes . There was a marked decrease in mucus on the surface of pilocarpine-treated membranes . CONCLUSIONS . Intestinal mucus secretion is a critical factor in the barrier function of the gut, and its depletion results in a dramatic increase in bacterial passage across the intact rat ileum.

Immunol Lett, 1994 Jul, 41(2-3), 121 - 2
Human T-cell repertoire, heterogeneity and memory: relevance to malaria; Beverley PC; There is abundant evidence that most non-exposed donors have cells able to respond to malaria antigens . These cells have the properties of memory T cells and probably arise as a result of cross-reactive priming by other microbial antigens . The existence of a high frequency of cross-reactive primed cells would be predicted to bias the response to malaria antigens, both in terms of specificity and the type of effector cells generated . It is possible that this bias may interfere with the development of effective anti-malaria responses.

Zh Mikrobiol Epidemiol Immunobiol, 1994 Jul-Aug, (4), 103 - 8
{A rapid specific reaction of the blood phagocytes to bacteria and the new possibilities for its diagnostic determination in infections}; Kaplin VN; Materials on the study of specific reaction of phagocytes, rapidly appearing after the contact of the body with soluble microbial substances, are presented . The study has established that of the reaction-inducing stimulus has a non-antigenic character and it acts directly on phagocytes . The method for the determination of phagocytic reaction by the ratio of the phagocytosis levels in the specific and control objects has been developed, which makes it possible to use a common diagnostic criterion for different infections and to diagnose them from the onset of the disease.

Exp Toxicol Pathol, 1994 Jul, 46(2), 127 - 32
Peroxisome proliferation of hepatocytes in rats by a microbial degradation product of cholic acid, 4-(decahydro-6-methyl-3-oxocyclopenta(f)quinoline-7-yl)valeric acid; Hayashi Y et al.; Three-week oral administration of 4-(decahydro-6-methyl-3-oxo-cyclopenta(f)quinoline-7-yl)valeric acid (32-1328) in the diet supplemented at concentrations of 0.1% or 0.3% was associated with hepatomegaly and hypotriglyceridemia in male F344 rats . Electron microscopic examination of the liver revealed a remarkable increase of peroxisomes in hepatocytes both in number and size . Biochemically, there were increased activities of peroxisomal marker enzymes including the heat-labile enoyl-CoA hydratase and catalase while the mitochondrial enoyl-CoA hydratase activity was unchanged after feeding of 32-1328 . These findings indicate that 32-1328 can exert peroxisome-proliferating activity to rat liver in a manner similar to typical peroxisome proliferators such as clofibrate or di(2-ethylhexyl)phthalate.

Immunology, 1994 Jul, 82(3), 457 - 64
Nitrite production by macrophages derived from BCG-resistant and -susceptible congenic mouse strains in response to IFN-gamma and infection with BCG; Barrera LF et al.; Reactive nitrogen intermediates (RNI) have been implicated in the interferon-gamma (IFN-gamma)-induced anti-microbial action of macrophages against a wide variety of pathogens . We have been studying the production of NO2- by macrophage lines derived from the bone marrow of either B10.A (Bcgs) strain mice (B10S cell lines), or their congenic BCG-resistant partners of the B10A.Bcgr (Bcgr) strain (B10R cell lines) . We have discovered that there is a significant difference in the production of NO2- of B10S compared with B10R macrophages in response to IFN-gamma . By 48 hr following treatment with 10 U/ml IFN-gamma, B10R macrophages had produced an approximately threefold higher level of NO2- than B10S macrophages . Similar results were obtained when experiments were performed with total splenic cells harvested from the spleens of B10.A.Bcgr and B10.A strain mice . The bacteriostatic activity, as assessed by the {3H}uracil incorporation by Mycobacterium bovis BCG, was higher in B10R macrophages compared to B10S macrophages . The bacteriostatic activity of B10R and B10S macrophages correlated with the amount of nitric oxide produced by the macrophages . The anti-mycobacterial activity was inhibited by NgMMLA, a specific inhibitor of nitrite and nitrate synthesis from L-arginine . Addition of L-arginine to IFN-gamma-stimulated macrophages in the presence of NgMMLA restored nitrite production and bacteriostatic activity of macrophages . Northern blot analysis of macrophage nitric oxide synthase (iNOS) revealed that the difference in NO2- production by IFN-gamma-treated B10S and B10R lines was reflective of the difference in iNOS mRNA expression.

Genomics, 1994 Jul 1, 22(1), 108 - 17
A versatile method for efficient YAC transfer between any two strains; Hugerat Y et al.; The ability to transfer yeast artificial chromosome (YAC) clones among yeast hosts greatly enhances their utility as cloned DNAs by increasing the range of methods available for experimental manipulation . An effective method for the transfer of YACs between strains in Kar1- matings is described in the accompanying paper (F . Spencer et al., 1994, Genomics 22, 118-126) . To evaluate the general nature of the new methodology, we compare YAC transfer in matings in which the YAC donor, the recipient, or both partners carry the kar1 mutation . A set of four universal kar1 intermediary strains that allow YAC transfer from any source to any target strain of the same or of opposite mating type is described . The procedure requires elementary microbial manipulations, including yeast culture and replica plating, and pulsed-field gel electrophoresis for verification of the YAC transfer and integrity . Transfer of YACs by Kar1- mating provides an efficient, reliable, and highly flexible technique that will greatly facilitate YAC manipulation required for a wide variety of applications.

Vet Clin North Am Food Anim Pract, 1994 Jul, 10(2), 371 - 82
Update on llama medicine . Ophthalmology; Gionfriddo JR; Review of the limited literature on camelid eyes suggests they are anatomically similar to those of domestic livestock species, except they lack meibomian glands and have iridial folds (rather than corpora nigra) . The microbial flora of the healthy camelid conjunctival sac also appears to be similar to those of domestic livestock and pets, except that no Mycoplasma have been isolated from camelids . Ocular diseases for which camelids are presented to veterinarians are numerous and varied . The most frequently presented conditions are ocular trauma and congenital abnormalities . Trauma to cornea, conjunctiva, eyelids, and sclera has been reported . Therapies for these injuries are the same as for other animals . Most congenital abnormalities are cataracts and optic nerve colobomas, but congenital eyelid defects, conjunctival cysts, and multiple ocular defects have been reported . Although these conditions are not demonstrably hereditary, breeding of animals with congenital ocular defects is strongly discouraged . Intraocular inflammatory diseases are seen commonly in camelids . Uveitis and chorioretinitis may cause permanent visual loss, usually with no indication of cause . Equine herpesvirus 1 has been isolated from camelids with severe ocular inflammation and is a known cause of chorioretinitis and neurologic abnormalities . Systemic aspergillosis causes severe chorioretinitis in alpacas . More research is needed to improve our understanding of ocular physiology and pathology in camelids . Genetic studies also are needed to establish hereditary patterns of ocular maldevelopment . Additional information from researchers and practitioners should improve our ability to recognize and treat ocular disease in camelids.

Br Poult Sci, 1994 Jul, 35(3), 345 - 54
Use of a marker organism in poultry processing to identify sites of cross-contamination and evaluate possible control measures; Mead GC et al.; 1 . Nine different sites at a poultry processing plant were selected in the course of a hazard analysis to investigate the degree of microbial cross-contamination that could occur during processing and the effectiveness of possible control measures . 2 . At each site, carcases, equipment or working surfaces were inoculated with a non-pathogenic strain of nalidixic acid-resistant Escherichia coli K12; transmission of the organism among carcases being processed was followed qualitatively and, where appropriate, quantitatively . 3 . The degree of cross-contamination and the extent to which it could be controlled by the proposed measures varied from one site to another.

Int J STD AIDS, 1994 Jul-Aug, 5(4), 257 - 61
Effect of sexual practices on T cell subsets and delayed hypersensitivity in transsexuals and female sex workers; Ratnam KV; To determine whether ano-receptive unprotected sexual intercourse (SI) practised by transsexuals produces immunological abnormalities we compared delayed hypersensitivity skin tests (DTH) and T cell helper (CD4) and suppressor (CD8) subsets in 57 transsexuals and 69 female sex worker controls . The populations were matched for age, duration of prostitution, number of clients and previous use of antibiotics . Heterosexual males and females and transsexuals who practised protected SI, were also included as controls . All were HIV negative . There were significantly increased absolute CD4 and CD8 counts and decreased DTH and CD4/CD8 ratios in those who practised unprotected ano-receptive SI . These changes were unlikely to be due to any of the microbial agents tested . We conclude that ano-receptive sexual intercourse results in increased immunological abnormalities in these sex workers possibly as a result of rectal exposure to seminal alloantigens . These abnormalities could play an important role as co-factors in disease transmission.

J Pathol, 1994 Jul, 173(3), 269 - 82
Borrelia burgdorferi-induced ultrastructural alterations in human phagocytes: a clue to pathogenicity?
Rittig MG, Haupl T, Krause A, Kressel M, Groscurth P, Burmester GR.
A chronic infection with the spirochaete Borrelia burgdorferi typically results in a multistage, multisystem illness . Thus, Lyme borreliosis may provide an interesting model to study the pathomechanisms of microbial persistence . In the present investigation, human peripheral blood monocytes, polymorphonuclear leukocytes, and synovial macrophages were incubated with B . burgdorferi and examined by light and electron microscopy . It was found that incubation with the spirochaetes induced distinct features in the phagocytes . Features which may be related to the pathogenesis of Lyme disease included the segmental uptake of spirochaetes with leaky lysosomes, the invagination of large membrane areas, the extra-lysosomal degradation of internalized B . burgdorferi cells and, finally, the formation of mononuclear syncytial cells and homotypic cell clusters . Features of unknown relevance were the occurrence of two types of cytoplasmic inclusion bodies and exocytic vesicles . These novel findings suggest that reactive alterations of the phagocytes may contribute to the pathogenesis of Lyme borreliosis, which could help to focus future histopathological studies . Moreover, these results may provide new insights into the pathogenesis of other infectious diseases characterized similarly by microbial persistence.

Biophys J, 1994 Jul, 67(1), 29 - 35
Mechanism of light modulation: identification of potential redox-sensitive cysteines distal to catalytic site in light-activated chloroplast enzymes; Li D et al.; Light-dependent reduction of target disulfides on certain chloroplast enzymes results in a change in activity . We have modeled the tertiary structure of four of these enzymes, namely NADP-linked glyceraldehyde-3-P dehydrogenase, NADP-linked malate dehydrogenase, sedoheptulose bisphosphatase, and fructose bisphosphatase . Models are based on x-ray crystal structures from non-plant species . Each of these enzymes consists of two domains connected by a hinge . Modeling suggests that oxidation of two crucial cysteines to cystine would restrict motion around the hinge in the two dehydrogenases and influence the conformation of the active site . The cysteine residues in the two phosphatases are located in a region known to be sensitive to allosteric modifiers and to be involved in mediating structural changes in mammalian and microbial fructose bisphosphatases . Apparently, the same region is involved in covalent modification of phosphatase activity in the chloroplast.

Adv Dent Res, 1994 Jul, 8(2), 320 - 8
Pathogenic mechanisms in periodontal disease; Smalley JW; Periodontal diseases have been considered as "infections" in which micro-organisms initiate and maintain the destructive inflammatory response . Host-mediated tissue destruction occurs via complement activation and the release of lysosomal enzymes, and connective tissue matrix metalloproteinases . Microbial enzymes may damage connective tissues directly, and, together with toxic metabolites and structural materials, are thought to disrupt the reparative activities of fibroblasts and cells of the immune defenses . The significance and relative contributions of host and microbial factors to the disease process remain unresolved . Environmental changes in the gingival sulcus and periodontal pocket and tissues, the degree of the host response and nutrient availability, concomitant with disease progression, compromise tissue metabolism and repair, and allow for enhanced or de novo expression of microbial virulence factors, such as proteases, which alter microbial pathogenicity . Proteolytic destruction of specific antibodies and complement by both viable and non-viable bacterial cells may retard phagocytic killing and removal of pathogens, thus prolonging the inflammatory response . Bacterial products may indirectly mediate tissue destruction by stimulating release of matrix metalloproteinases or by proteolytically inactivating the specific inhibitors of these enzymes.

Adv Dent Res, 1994 Jul, 8(2), 229 - 38
Caries-protective factors in saliva; Lagerlof F et al.; Saliva influences caries attack mainly by its rate of flow and by its content of fluoride . The salivary flow rate influences to a high degree the rate of oral and salivary clearance of bacterial substrates included in foods and snacks . This influence is site-dependent . The basal salivary fluoride concentration is low, about 1 mumol/L, independent of salivary flow rate, and not influenced by diurnal variation . After an exposure of the oral cavity to fluoride, the increased fluoride level is decreased by a process influenced mainly by the salivary flow rate and the volumes of saliva in the mouth before and after swallowing . Other less important caries-protective factors in saliva include its buffer ability, its content of calcium, inorganic phosphate, pH-increasing substances, and anti-microbial agents.

Microb Pathog, 1994 Jul, 17(1), 51 - 62
Phosphatase-negative mutants of Legionella pneumophila and their behavior in mammalian cell infection; Kim MJ et al.; Microbial phosphatases are known or suspected to play a role in the pathogenesis of several intracellular pathogens, including Legionella micdadei . Legionella pneumophila also possess phosphatase activities, but their possible roles in cellular infection are unknown . We generated mutants of a serogroup 1 isolate of L . pneumophila that lack the major phosphatase . Isolation of a Pho- mutant after random mutagenesis with transposon MudII4041 allowed us to dissociate the major alkaline phosphatase (pH optimum approximately 8) from a minor acid phosphatase activity . Both activities were concentrated in the bacterial periplasm . The gene encoding the major alkaline phosphatase (pho) was cloned by expression in E . coli and used to generate a site directed mutation in two L . pneumophila strains . Each parent-mutant pair was compared in a U937 cell tissue culture assay for capacity to infect, lyse, and grow within mammalian cells . Although the parental stains differed in their U937 cell cytopathicity, neither was significantly more infective than its Pho- derivative, suggesting that the alkaline phosphatase activity is not essential for cellular infection . Because they are not attenuated, Pho- mutants can be used to generate gene fusions with E . coli alkaline phosphatase to study and secretion and cellular infectivity in L . pneumophila.

Bioorg Med Chem, 1994 Jul, 2(7), 697 - 705
Inhibition of lipases by phosphonates; Bjorkling F et al.; Ethyl hexylchlorophosphonate and analogues thereof were investigated as inhibitors of lipases . Both microbial and mammalian lipases were irreversibly inhibited . The inhibition could be monitored by p-nitrophenol release from the corresponding ethyl p-nitrophenyl hexylphosphonate inhibitor . Quantitative analysis of the data indicated that a 1:1 lipase-inhibitor complex was formed during inhibition . Enantioselective inhibition was found for the lipases derived from Candida antarctica and Rhizomucor miehei using pure enantiomers of ethyl p-nitrophenyl hexylphosphonate as inhibitors . Using the same inhibitor, reversed enantioselectivity was found for the protease alpha-chymotrypsin as compared to the two lipases.

Stomatologiia (Mosk), 1994 Jul-Sep, 73(3), 5 - 7
{The dental pulp reaction to microbial action in different methods of treating the carious cavity}; Elizova LA et al.; Under study were the effects of bacterial stimulation of prepared dentin on dental pulp . Traditional method of drug treatment of prepared cavity with alcohol and either was compared with methods reducing dentin permeability making use of calcium hydroxide, potassium nitrate, and calcium oxalate . Inflammatory reaction of the pulp was more pronounced after traditional treatment . Reduction of dentin permeability with agents blocking dentin tubes reduced the severity of inflammatory reaction.

Am J Physiol, 1994 Jul, 267(1 Pt 2), R53 - 61
Somnogenic effects of rabbit and recombinant human interferons in rabbits; Kimura M et al.; Interferons (IFNs) are antiviral cytokines that possess several central nervous system activities . IFN therapy is associated with sleepiness, and the IFNs expressed during viral infection may be involved in the excess sleep associated with these infections . Most viruses stimulate the production of both IFN-alpha and IFN-beta . Although large doses of human IFN-alpha 2 are somnogenic in rabbits, the effects of species-specific IFNs on sleep in the rabbit have not been documented . We compared the somnogenic and antiviral effects of IFNs derived from rabbits to the effects of recombinant human (rh) IFN-alpha and IFN-beta . When injected intracerebroventricularly, rhIFN-alpha A/D, rabbit IFN-alpha/beta, and rabbit reference IFN induced non-rapid-eye-movement sleep and fever in a dose-dependent manner . However, the doses of rabbit IFNs required to induce sleep were much lower than those of human IFNs . Heat treatment of both rabbit IFNs and human IFNs greatly reduced their in vitro antiviral effects . The in vivo activities of rabbit IFNs and rhIFN-alpha A/D were significantly attenuated after heat treatment . However, rhIFN-beta retained its sleep-promoting action after heat treatment, suggesting that microbial contaminants were responsible for its somnogenic and pyrogenic activities . We conclude that IFN-alpha is somnogenic.

J Biol Chem, 1994 Jun 24, 269(25), 17146 - 51
Superoxide-dependent hydroxylation by myeloperoxidase; Kettle AJ et al.; When stimulated, neutrophils undergo a respiratory burst converting oxygen to superoxide . Although superoxide is critical for microbial killing by phagocytic cells, the precise role it plays has yet to be established . It has been proposed to optimize their production of hypochlorous acid and to be required for the generation of hydroxyl radicals . Superoxide is also involved in the hydroxylation of salicylate by neutrophils . However, the mechanism of this reaction is unknown . We found that neutrophils stimulated with opsonized zymosan hydroxylated salicylate to produce mainly 2,5-dihydroxybenzoate . Its formation was dependent on superoxide and a heme protein but was independent of hydrogen peroxide and hydroxyl radicals . Production of 2,5-dihydroxybenzoate was enhanced by methionine, which scavenges hypochlorous acid . Neutrophils from an individual with myeloperoxidase deficiency hydroxylated salicylate at only 13% of the level of control cells . Purified human myeloperoxidase and xanthine oxidase plus hypoxanthine hydroxylated salicylate to produce 2,5-dihydroxybenzoate . As with neutrophils, the reaction required superoxide but not hydrogen peroxide and was unaffected by hydroxyl radical scavengers . Thus, myeloperoxidase catalyzes superoxide-dependent hydroxylation . This newly recognized reaction may be relevant to the in vivo functions of superoxide and myeloperoxidase.

Tidsskr Nor Laegeforen, 1994 Jun 20, 114(16), 1827 - 8
{Immunopathogenesis of atopic eczema}; Bjerke JR; The role of elevated serum IgE in patients with atopic eczema has been unclear . It has recently been shown that antigens from house dust mites may penetrate the skin, bind to IgE on Langerhans' cells, which in turn mediate the activation of antigen-specific TH2 cells that are the predominant T cells found in early atopic skin lesions . TH2 cells produce IL-4, which stimulates the IgE production by B lymphocytes, and are chemotactic for eosinophilic granulocytes . The discovery of microbial superantigens that activate T cells more easily and less specifically than the traditional antigens do, helps us to understand how local microbial agents can provoke the outburst of new atopic skin lesions.

J Immunol, 1994 Jun 15, 152(12), 5776 - 84
Administration of recombinant human IL-7 to mice alters the composition of B-lineage cells and T cell subsets, enhances T cell function, and induces regression of established metastases; Komschlies KL et al.; These studies investigate the effects of exogenously administered recombinant human IL-7 (rhIL-7) on mouse leukocyte subsets in vivo in normal and tumor-bearing mice . The administration of rhIL-7 to normal mice caused a pronounced leukocytosis (three- to fivefold increase over background) in the spleen and lymph nodes, with B-lineage and T cells, NK cells, and macrophages all being increased . CD8+ T cells increased disproportionately, such that the CD4 to CD8 ratio decreased dramatically . The rhIL-7-induced effects were dose-dependent, increased with duration of treatment, and were reversible after cessation of rhIL-7 administration . T cell number increases after rhIL-7 treatment were primarily a result of an expansion of the peripheral T cell population . Importantly, splenocytes from rhIL-7-treated mice have enhanced proliferative responses to various T cell stimuli in vitro and were able to potentiate an allogeneic CTL response in vivo . The rhIL-7-induced changes in T cell number and the CD4 to CD8 ratio also were observed in mice bearing early Renca renal adenocarcinoma pulmonary metastases, and these changes coincided with up to a 75% reduction in pulmonary metastases . Overall, these results demonstrate that the administration of rhIL-7 to mice profoundly increases the number of B and T cells, and reduces the number of pulmonary metastases . The results also suggest that IL-7 may be useful for restoring lymphoid subsets in immunosuppressed hosts and in enhancing T cell-mediated immune responses . Such effects may be useful in the treatment of microbial diseases and cancer.

Gene, 1994 Jun 10, 143(2), 265 - 9
Structure of the bovine lactoferrin-encoding gene and its promoter; Seyfert HM et al.; Lactoferrin (Lf), a ferric ion (Fe3+)-binding glycoprotein, is found most notably in milk, probably to mediate protection against microbial infection of the mammary gland . Based on an initial isolation and sequencing of a complete cDNA of the bovine Lf gene (bLf), the complete gene was obtained from genomic libraries on five overlapping phage lambda EMBL3 clones . A detailed restriction map and the complete exon/intron structure of the gene are presented, together with 1 kb of sequence data of the promoter upstream from the proximal exon . The coding sequence is dispersed over 17 exons spanning 34.5 kb of genomic DNA . While the exons are of similar size, as in other members of the transferrin gene family (Tf), some of the intron sizes are very different . Evolutionary conservation of both exon sizes and their contribution to the various domains of the protein molecule add to the evidence that Lf originated via an internal sequence duplication . The promoter sequence lacks some of the sequence motifs for transcriptional enhancers found in the promoters of human and mouse Lf, suggesting a potential reason for the relatively weak expression of bLf.

Immunol Cell Biol, 1994 Jun, 72(3), 262 - 6
Immunity and inflammation: the cosmic view; Quintans J; This paper presents an overview of the evolution of defence reactions in multicellular animal life . The co-evolution of hosts and pathogens provides the context to describe the major features of defence reactions and the countermeasures they evoke in their targets . Three major types of solutions to the riddle of self-non-self discrimination are discussed briefly: non-clonal recognition mediated by lectins, the preferential accumulation of C3 in microbial surfaces and vertebrate clonal immunity . Vertebrate immunity is described as a specialized type of inflammation against infectious agents that evolved in response to countermeasures successfully used by intracellular pathogens against non-specific defences.

J Dairy Sci, 1994 Jun, 77(6), 1556 - 62
Effect of isocaloric infusion of glucose in the rumen or propionate in the duodenum; Wu Z et al.; This study was undertaken to understand better the mechanisms causing increased milk protein . Cows fed steam-flaked sorghum have increased milk protein compared with that of cows fed dry-rolled sorghum because of a large shift of starch digestion from the intestine to the rumen . Five cannulated lactating cows were infused with glucose in the rumen or with propionate in the duodenum in two trials . The experimental design was a 2 x 2 Latin square with 7 d of adjustment and 7 d of infusion . During the experiment, cows received a TMR containing 19.3% CP and 1.56 Mcal/kg of NEL (on a DM basis); alfalfa hay and dry-rolled sorghum grain were the principal ingredients . Similar concentrations in feces of cows among propionate treatments suggested complete absorption of infused propionate . Milk yield did not differ, but protein percentage of milk was higher (2.88 versus 2.72%) for cows infused ruminally with glucose than for those infused in the duodenum with propionate . For the respective treatments, duodenal flows were 2.11 and 1.76 kg/d for microbial protein and 3.44 and 2.73 kg/d for total CP (or 85 and 74% of CP intake) . These data demonstrate that increased propionate availability for gluconeogenesis and a possible sparing of essential AA did not result in increased milk protein content, but ruminal infusion of glucose, which tended to increase microbial protein synthesis, did increase the protein percentage of milk.

AIDS Educ Prev, 1994 Jun, 6(3), 249 - 65
Magical contagion and AIDS risk perception in a college population; Nemeroff CJ et al.; This study examined whether common reactions to AIDS are consistent with operation of the "magical law of contagion," a traditional belief that describes the transfer of properties, whether moral or physical, harmful or beneficial, through contact . Three features of magical contagion, explored in previous work, were re-examined . These features sometimes contrast with microbial contamination as described by modern germ theory . They are: permanence of effects; dose-insensitivity; and potential for effects to act backwards (i.e., from recipient back onto source) . A fourth characteristic, previously unaddressed, was also explored: "moral-germ conflation," i.e., the tendency to incompletely distinguish illness from evil . Three hundred and ninety-nine college students completed a survey assessing each feature with regard to AIDS-related scenarios . Also assessed was general AIDS knowledge . Subjects were very well-informed about AIDS, yet a significant subset showed "magical" features of thinking . Consistent with moral-germ conflation, degree of worry about getting AIDS was better predicted by guilt than by risk behaviors and knowledge that they are risky . Implications are discussed.

Z Ernahrungswiss, 1994 Jun, 33(2), 128 - 35
Dietary effect of phytogenic phytase and an addition of microbial phytase to a diet based on field beans, wheat, peas and barley on the utilization of phosphorus, calcium, magnesium, zinc and protein in piglets; Pallauf J et al.; The effect of the addition of microbial phytase to a diet based on field beans (30%), wheat (28%), peas (25%), and barley (14%) was studied in a 2-week experiment with 3 x 8 castrated male, individually housed, hybrid piglets (live weight range 12-16 kg) . All diets contained about 4.7 g Ca, 4.2 g P (77% present as phytate phosphorus), 1.0 g Mg, 60 mg Zn per kg diet, and 17% crude protein . Group I was fed the basal diet with a native phytase-activity of about 260 U per kg diet . In group II, 350 U, in group III, 700 U of microbial phytase per kg diet were added . The addition of microbial phytase improved the apparent P absorption (% of intake) from 48% (group I) to 66% (group II) and 71% (group III) . Comparable positive effects from the phytase treatment were obtained for the calcium utilization . The phytase supplementation also enhanced plasma zinc concentration significantly . The concentration of inorganic phosphorus in plasma, the zinc digestibility, and the magnesium balance were improved in tendency . The utilization of nitrogen remained unchanged.

Immunol Today, 1994 Jun, 15(6), 281 - 7
Chemokine receptors and molecular mimicry; Ahuja SK et al.; Chemokines are small pro-inflammatory peptides that are best known for their leukocyte-chemoattractant activity . The cloned leukocyte chemokine receptors, interleukin 8 receptor (IL-8R) types A and B and the macrophage inflammatory protein 1 alpha (MIP-1 alpha)/RANTES receptor, are related by sequence and chemokine binding to two herpesvirus products, and to the Duffy antigen that mediates erythrocyte invasion by the malaria-causing parasite Plasmodium vivax . Here, Sunil Ahuja, Ji-Liang Gao and Philip Murphy suggest that, in addition to the activation of leukocytes, chemokines may be important in the function of erythrocytes and, through molecular mimicry, in microbial pathogenesis.

Pharmazie, 1994 Jun, 49(6), 428 - 32
{Determination of E . coli with MUG (Fluorocult)-lauryl sulfate broth for the testing of microbial contamination in drugs}; Huang H et al.; A test method for the determination of Escherichia coli in plant materials with the MUG (Fluorocult)-lauryl sulfate broth is described . It was found that more than 75% of the commonly used vegetable drugs exhibit fluorescence quench effects to different degrees when determining E . coli with the MUG-lauryl sulfate broth . Therefore a simple combination of two procedures was evaluated in order to avoid the matrix interferences: in a first step the drug sample was diluted eight times in a proportion of 1:10 with MUG-lauryl sulfate broth in eight separate tubes from 1 g down to 10(-7) g/tube (1st test series) and the resulting samples were incubated for 40 h at 36 degrees C . Subsequently, the tubes were tested for fluorescence . If the first tube of this series was found without fluorescence, in a second step a subsequent series of MUG-lauryl sulfate broth (2nd test series) was inoculated with 0.5 ml of the incubated culture from each of the first three tubes of series 1 and incubated again for 24 h at 36 degrees C . The results were evaluated from gas production, fluorescence as well as indole formation . Thus, the method allowed a simple and reproducible enumeration of E . coli for the test on microbial contamination in medicinal plant materials . The method was successfully applied to samples of 38 vegetable drugs for quantitative determination of E . coli (8 samples were found being contaminated with E . coli).

J Prosthet Dent, 1994 Jun, 71(6), 603 - 6
Effectiveness of a professional formula disinfectant for irreversible hydrocolloid; Kaplan BA et al.; In this study, the effectiveness of Professional Lysol (PL) disinfectant in both its spray and solution forms was evaluated as a surface disinfectant for irreversible hydrocolloid (IH) impressions . Sixteen impressions of a typodont were made with IH, immersed in a microbial broth, and then rinsed in running tap water . The impressions were then treated as follows: four were immersed in PL for 2.5 minutes; four were sprayed by PL and stored for 10 minutes; four were immersed in 2% glutaraldehyde for 10 minutes; four were untreated . Pretest plates showed an average of 421 colonies per plate (c/p) . The glutaraldehyde group showed 0.00 c/p . The PL spray group showed 1.75 c/p . The PL immersion group showed 19.00 c/p and showed evidence of surface deterioration in the IH . The untreated group showed 426.25 c/p.

Am J Respir Cell Mol Biol, 1994 Jun, 10(6), 658 - 64
A mouse model of lung injury induced by microbial products: implication of tumor necrosis factor; Denis M et al.; Mice of the C57BL/6 strain were injected with bacterial lipopolysaccharide (LPS) followed by formylnorleucyl-leucyl-phenylalanine (FNLP) by the intraperitoneal route; markers of acute lung injury were examined in mice given a fusion protein of soluble human tumor necrosis factor-alpha (TNF-alpha) receptor (p80) linked to the Fc portion of human IgG (TNFR:Fc) or excipient . Challenge with LPS/FNLP elicited an adult respiratory distress syndrome-like pathology characterized by sharp increases in levels of lactate dehydrogenase (LDH) and total proteins in bronchoalveolar lavage as well as in lung myeloperoxidase (MPO) content at 16 and 20 h after challenge . Infusion of 1 mg of TNFR:Fc 2 h before challenge very significantly abrogated the increases in LDH, protein levels, and MPO . Histologic analysis revealed that LPS/FNLP infusion resulted in an intravascular neutrophil agglomerate and perivascular/peribronchial damage; the extent of tissue lesions was significantly reduced, but not abrogated, by TNF-alpha depletion . There were moderate levels of antigenic TNF-alpha in lung homogenates at 16 and 20 h after challenge, not affected by infusion with TNFR:Fc . No bioactive TNF-alpha was detected in lung homogenates of challenged mice given TNFR:Fc . High levels of antigenic interleukin-6 (IL-6) were found in lung homogenates of challenged mice treated with TNFR:Fc or with diluent . Elevated levels of antigenic IL-6 and TNF-alpha were found in sera of challenged mice at 16 and 20 h after injection; TNFR:Fc-treated mice had a higher level of antigenic TNF-alpha than did challenged mice given diluent, but it was not bioactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Int J Biol Macromol, 1994 Jun, 16(3), 121 - 4
Depolymerization reactions of hyaluronic acid in solution; Rehakova M et al.; Samples of microbial sodium hyaluronate were degraded by heating, ultrasonication ultraviolet (UV) and gamma-ray irradiation and enzymatic treatment . The weight-average molecular weight, Mw, of hyaluronate in 0.15 M NaCl and 0.06 M Na2HPO4 was determined by gel filtration with UV detection . The Mw of the degraded samples varied from 8 x 10(4) to 1.38 x 10(6) . Depolymerization processes can be described by linear relationship (1/Mw)2 = f(t) in the case of ultrasonic treatment and by non-linear relationships in the cases of heating and UV irradiation at 257 nm . Gamma-ray irradiation and enzymatic treatment caused chemical degradation and depolymerization to oligosaccharides, respectively.

Int J Biol Macromol, 1994 Jun, 16(3), 115 - 9
Biosynthesis from gluconate of a random copolyester consisting of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoates by Pseudomonas sp . 61-3; Abe H et al.; Pseudomonas sp . 61-3 isolated from soil was found to produce a polyester consisting of 3-hydroxyalkanoic acids of even carbon numbers C4, C6, C8, C10 and C12 when sodium gluconate was fed as the sole carbon source . The polyester produced was fractionated with boiling acetone . The acetone-insoluble fraction (28 wt%) of the polyester was a poly(3-hydroxybutyrate) homopolymer, while the acetone-soluble fraction (72 wt%) was composed of seven different 3-hydroxyalkanoate (3HA) units ranging from C4 to C12: 40 mol% 3-hydroxybutyrate (3HB), 5 mol% 3-hydroxyhexanoate (3HH), 20 mol% 3-hydroxyoctanoate (3HO), 24 mol% 3-hydroxydecanoate (3HD), 1 mol% 3-hydroxy-5-cis-decenoate (3H5D), 4 mol% 3-hydroxydodecanoate (3HDD) and 6 mol% 3-hydroxy-5-cis- dodecenoate (3H5DD) . The copolymer was characterized by nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography and differential scanning calorimetry . The acetone-soluble fraction of this amorphous copolymer was shown to have a random sequence distribution of the seven 3HA units of C4 to C12 by analysis of the 150 MHz 13C-NMR spectrum . This is the first example of microbial synthesis of a random copolyester consisting of 3HB and medium-chain-length 3HA units.

J Clin Pharm Ther, 1994 Jun, 19(3), 181 - 7
Influence of background air on microbial contamination during simulated i.v.-admixture preparation; van Doorne H et al.; The effect of the cleanliness of environmental air on the microbial contamination of a simulated i.v.-admixture during its preparation by aseptic transfer was studied under three conditions: (i) in a laminar air flow (LAF) bench situated in a class 1000 clean room, (ii) in an LAF bench in a microbiology laboratory and (iii) on a bench in an ordinary laboratory . Three thousand bottles were manually filled with 10 ml of a nutrient broth under each of the three conditions . The liquid was transferred by means of a syringe and a needle that pierced through the rubber closures of the bottles . The numbers of contaminated bottles under those three conditions were 1, 1 and 2, respectively . Background contamination had no demonstrable effect on the incidence of contamination, provided that preparation of the simulated i.v.-admixture solution was performed by skilled personnel in an LAF cabinet and air contact is avoided.

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