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.<