Bacteriological

Pharmacol Toxicol, 1997 May, 80(5), 246 - 50
Bioavailability of enrofloxacin after oral administration to fed and fasted pigs; Nielsen P et al.; The disposition of enrofloxacin was measured after intravenous and oral administration to pigs . Eight clinically healthy pigs weighing 25 to 40 kg received a dose of 5 mg/kg intravenously and 10 mg/kg orally in both a fasted and a fed condition in a three-way cross-over design . Enrofloxacin was present in plasma for up to 72 hr after both intravenous and oral administration to fasted as well as fed pigs . The steady state volume of distribution was determined to 3.9 +/- 0.5 1/kg body weight which indicates that enrofloxacin was widely distributed in the body . The bioavailability was determined to 83 +/- 13% in fed and to 101 +/- 32% in fasted pigs . Based on the bioavailability and the resulting plasma concentrations it is concluded that a therapeutically active concentration for the most common porcine microbial pathogens are maintained for at least 24 hr after oral administration of 10 mg/kg body weight to fasted as well as to fed pigs . Ciprofloxacin which is an active metabolite of enrofloxacin was observed in plasma samples from all treated pigs, but the concentration never exceeded 0.1 microgram/ml . During the first 24 hr after the administration of enrofloxacin the concentration of the metabolite made up less than 10% of the corresponding concentration of the parent compound.

Biosci Biotechnol Biochem, 1997 May, 61(5), 830 - 5
High-level expression of the chemically synthesized gene for microbial transglutaminase from Streptoverticillium in Escherichia coli; Kawai M et al.; We developed a novel approach for the high-level production of a microbial transglutaminase (TGase) from Streptoverticillium in E . coli . The direct expression of the TGase gene in E . coli cells did not cause overproduction, probably due to the harmful influence of TGase activity, which introduces covalent crosslinks between proteins . Therefore, we fused the chemically synthesized TGase gene coding for the entire 331 amino acid residues at the amino terminus to a bacteriophage T7 gene 10 leader peptide (260 amino acids) using an inducible expression vector . The TGase gene was expressed as inclusion bodies in the E . coli cytoplasm . Restoring 15 amino acid residues upstream of the amino terminus of the mature TGase by a two-step deletion of the fusion sequence facilitated solubilization and subsequent proteolytic cleavage, thus releasing mature TGase . Although the mature form had less TGase activity than native TGase, because of the poor refolding rate, these results suggest that this system is suitable for the efficient production of TGase.

Br J Nutr, 1997 May, 77(5), 745 - 56
The energy value of short-chain fatty acids infused into the caecum of pigs; Jorgensen H et al.; The present work was undertaken to study the energy value of a mixture of acetic, propionic and butyric acids (0.682:0.226:0.092) infused intracaecally in growing pigs . A basal diet low in fibre (42 g NSP/kg DM) was given at below the requirement for maximum weight gain . In six 2-week periods, N and energy balance measurements in eight growing pigs were carried out with and without infusion of short-chain fatty acids (SCFA) . Heat production was measured using open-circuit chambers and the concentration of SCFA in faeces was determined . Less than 1% of the infused SCFA was excreted in faeces illustrating the capacity of the hind-gut to absorb and metabolize SCFA . Infusion of SCFA did not affect the digestibility of nutrients and energy . However, N retention increased demonstrating that SCFA are an energy source for protein gain when pigs are fed at below the requirement of energy . Increased CH4 production together with an increased excretion of branched-chain fatty acids in faeces suggested that there was a higher microbial activity in the hind-gut during infusion . The partial utilization of the infused energy in SCFA was 0.821 . A small proportion of the infused energy in SCFA was retained in protein (0.099) and a considerable amount was retained as fat (0.722).

J Hosp Infect, 1997 May, 36(1), 49 - 65
An evaluation of five protocols for surgical handwashing in relation to skin condition and microbial counts; Pereira LJ et al.; Five protocols for surgical handwashing (scrubbing) were evaluated for their efficiency of removal of micro-organisms and their drying effect on the skin . The scrubbing protocols tested were: (1) an initial scrub of 5 min and consecutive scrubs of 3.5 min with chlorhexidine gluconate 4% (CHG-5); (2) an initial scrub of 3 min and consecutive scrubs of 2.5 min with chlorhexidine gluconate 4% (CHG-3); (3) an initial scrub of 3 min and consecutive scrubs of 2.5 min with povidone iodine 5% and triclosan 1% (PI-3); (4) an initial scrub of 2 min with chlorhexidine gluconate 4% followed by a 30 s application of isopropanol 70% and chlorhexidine gluconate 0.5%, and a 30 s application of isopropanol 70% and chlorhexidine gluconate 0.5% for consecutive scrubs (IPA); and (5) an initial scrub of 2 min with chlorhexidine gluconate 4% followed by a 30 s application of ethanol 70% and chlorhexidine gluconate 0.5%, and a 30 s application of ethanol 70% and chlorhexidine gluconate 0.5% for consecutive scrubs (EA) . A convenience sample of 23 operating theatre nurses completed each scrub protocol for one week in a randomized order . A week of normal work activities intervened between each protocol . Subjects were assessed before commencing and after completing the week of each protocol to determine changes in the microbial counts and skin condition of the hands . Specimens for microbial analysis were collected before, immediately after and 2 h after an initial scrub, and 2 h after a consecutive scrub . The CHG-5, CHG-3 and PI-3 protocols, which used detergent-based antiseptics only, were compared with protocols incorporating an alcohol-based antiseptic (IPA and EA) . The protocols incorporating alcohol-based antiseptics and the CHG-5 protocol were generally associated with the lowest post-scrub numbers of colony forming units (cfu) . No difference between the CHG-5 protocol and the alcohol-based antiseptics was found at the beginning of the test week, but after exclusive use of the respective protocols for a week, the alcohol-based antiseptics were associated with significantly lower cfu numbers in two out of the three post-scrub samples (P = 0.003, P = 0.035) . Although virtually no statistically significant differences in skin condition were found, many subjects reported the alcohol-based antiseptic protocols to be less drying on the skin . The findings of this study support the proposition that a scrub protocol using alcohol-based antiseptics is as effective and no more damaging to skin than more time-consuming, conventional methods using detergent-based antiseptics.

J Formos Med Assoc, 1997 May, 96(5), 336 - 45
Constitutive fatty acid and enzyme profiles of Mycobacterium species; Teng LJ et al.; Sixty-one strains of Mycobacterium tuberculosis complex and 47 strains of nontuberculous mycobacteria were analyzed for fatty acids and enzyme profiles . Cellular fatty acids were extracted from bacteria, methylated and analyzed by gas liquid chromatography operated either manually (Perkin-Elmer) or by the automatic Microbial Identification System . The major cellular fatty acids in all mycobacterial species were C16:0 and C18:1 . Tuberculostearic acid was found in all species with the exception of Mycobacterium gordonae . The fatty acids with a carbon-length longer than 20 could be detected only by conventional gas chromatography . Strains of M . tuberculosis had a high ratio of C26:0 to C24:0, and a relatively low ratio of C14:0 to C15:0 . For determination of branched-chain fatty acids, the MIS provided more definitive results . The data indicated that the fatty acid profiles could provide rapid species identification . The results of the enzyme profile analysis using API-ZYM strips showed 39 different patterns from 59 strains of M . tuberculosis, and 41 different patterns from 46 nontuberculous mycobacteria strains, suggesting that enzyme profiles can also be used for strain characterization within the same species.

J Nat Prod, 1997 May, 60(5), 431 - 8
Isolation and characterization of new anti-HIV and cytotoxic leads from plants, marine, and microbial organisms; McKee TC et al.; New cytotoxic isomalabaricane triterpenes have been isolated from a sponge Stelletta sp . (1-7); anti-HIV pterocarpans (8 and 9) and isoflavanoids (12-16 and 18) were elucidated from two tropical plants in the genus Erythrina; and anti-HIV enniatins (20 and 22-23) were characterized from fungi in the genera Fusarium and Alternaria . The enniatins were evaluated for in vivo anti-HIV activity in the hollow fiber assay.

Obstet Gynecol, 1997 May, 89(5 Pt 2), 836 - 8
Postpartum endometritis caused by herpes simplex virus; Hollier LM et al.; BACKGROUND: Herpes simplex virus (HSV) is rarely the causative agent of endometritis and is usually found in association with pelvic inflammatory disease . Only one case of postpartum HSV endometritis has been reported . CASES: We describe two cases of herpes simplex postpartum endometritis . Neither patient had genital HSV lesions noted at the time of delivery . The first case developed after a preterm cesarean delivery in an 18-year-old primipara . She had persistent puerperal fever despite broad-spectrum anti-microbial treatment . The second case was a 16-year-old primipara whose vaginal delivery was complicated by severe postpartum endometritis . Vulvar and endometrial cultures were positive for HSV alone in both patients . Both infants died from disseminated HSV infection . CONCLUSION: Herpes simplex virus can cause clinical postpartum endometritis.

J Nutr, 1997 May, 127(5 Suppl), 951S - 957S
The public health threat of emerging viral disease; Morse SS; "Emerging diseases" are those that either have newly appeared in the population or are rapidly increasing their incidence or expanding their geographic range . Emerging viruses usually have identifiable sources, often existing viruses of animals or humans that have been given opportunities to infect new host populations ("viral traffic") . Environmental and social changes, frequently the result of human activities, can accelerate viral traffic, with consequent increases in disease emergence . Host factors, including nutrition, have often received less attention in the past but are of considerable importance . These factors, combined with the ongoing evolution of viral and microbial variants, make it likely that emerging infections will continue to appear and probably increase, emphasizing the need for effective surveillance.

J Nutr, 1997 May, 127(5 Suppl), 814S - 818S
Plant limitations to fiber digestion and utilization; Buxton DR et al.; Energy availability from forages is limited by fiber concentration because fiber is slowly and incompletely digested, whereas cell solubles are almost completely digested . Thus, the proportion of fiber to cell solubles is a major determinant of energy availability in forages . Grasses normally have more fiber than legumes, especially in leaves . Grass fiber is more digestible than that of legumes, but that of legumes digests at a faster rate . Ruminants digest 40-50% of legume fiber and 60-70% of grass fiber . Some fiber cannot be digested no matter how long it remains in the rumen . Lignin is thought to interfere with microbial degradation of fiber polysaccharides by acting as a physical barrier and by being cross-linked to polysaccharides by ferulate bridges . In addition to the effects of lignin, physical and structural barriers may limit fiber digestibility . Because the middle lamella and primary wall of thick-walled cells are so highly lignified, many cells can be digested only from the interior of the cell . For many cells, access to cell interiors is limited because of large particle sizes . Forage digestibility could be improved by reducing the amount of lignified cells or by developing improved cultivars so that lignified cells are more digestible.

Carcinogenesis, 1997 May, 18(5), 919 - 24
Mammalian DNA repair methyltransferases shield O4MeT from nucleotide excision repair; Samson L et al.; O6-Methylguanine (O6MeG) and O4-methylthymine (O4MeT) are potentially mutagenic DNA lesions that cause G:C-->A:T and A:T-->G:C transition mutations by mispairing during DNA replication, and the repair of O6MeG and O4MeT by DNA repair methyltransferases (MTases) is therefore expected to prevent methylation-induced transitions . The efficiency of O6MeG and O4MeT repair by different MTases can vary by several hundred-fold and the aim of this study was to establish the biological consequences of such differences in the efficiency of repair . The ability of three microbial and two mammalian MTases to prevent methylation-induced G:C-->A:T and A:T-->G:C transitions is taken as a measure of their ability to repair O6MeG and O4MeT in vivo respectively . All five MTases give complete protection against G:C-->A:T transitions . However, while the microbial MTases give complete protection against A:T-->G:C transitions, the mammalian MTases actually sensitize cells to A:T-->G:C transitions . We hypothesize that the mammalian MTases bind O4MeT lesions in vivo but that, because they are extremely slow at subsequent methyl transfer, binding shields O4MeT from repair by the nucleotide excision repair pathway . Results are presented to support this hypothesis.

Biochem Mol Biol Int, 1997 May, 41(6), 1137 - 41
Encystment-specific mRNA is accumulated in the resting cysts of the ciliate Colpoda inflata; Benitez L et al.; From a random amplified polymorphism cDNA study using vegetative, precystic and mature resting cysts of the ciliate Colpoda inflata, a stage-specific fragment was isolated from the resting cyst cDNA population . This fragment was used as an encystment probe to study the corresponding mRNA expression during this eukaryotic cell differentiation process . This transcript is accumulated in the resting cyst of this ciliate, and it is the first time that accumulation of specific mRNA molecules associated with the ciliate cryptobiosis process is reported . The meaning of this stored mRNA in microbial cryptobiotic stages is discussed.

Mol Ecol, 1997 May, 6(5), 475 - 82
Effect of PCR template concentration on the composition and distribution of total community 16S rDNA clone libraries; Chandler DP et al.; Total DNA from sediment samples was isolated by a direct lysis technique . Purified DNA was used as template either undiluted or diluted 1:10 prior to polymerase chain reaction (PCR) amplification of 16S rRNA genes . Full-length inserts were analysed for restriction fragment length polymorphisms (RFLP) with the enzyme Cfo1, and the resulting distribution and abundance of RFLP patterns compared between the undiluted and diluted PCR reactions . Results indicate that for low PCR template concentrations, in the range from a few picograms to tens of picograms DNA, proportional representation of specific RFLP types was not reproducible upon template dilution, confirming that PCR amplification of 16S rDNA cannot be used directly to infer microbial abundance . In particular, only 15-24% of the RFLP types recovered from a sample were present in both the undiluted and diluted extracts . We propose that very low template concentrations in the PCR generate random fluctuations in priming efficiency, which led to the contrast in RFLP types observed in the libraries from the undiluted and diluted extracts.

J Anim Sci, 1997 May, 75(5), 1415 - 24
Urea in dry-rolled corn diets: finishing steer performance, nutrient digestion, and microbial protein production; Milton CT et al.; In Exp . 1, 88 yearling steers (332 kg) were fed dry-rolled corn finishing diets to evaluate effects of dietary urea level on performance and carcass characteristics . Diets contained 0, .5, 1.0, or 1.5% urea (DM basis), which supplied all supplemental N, and 10% chopped prairie hay . Gains (P = .10) and gain efficiency (G/F; P < .05) were increased by .5% urea, with little improvement by additional urea . Regression analysis estimated optimal dietary urea at .9% of DM for ADG and G/F . Fat thickness (P < .05) and yield grade (P < .10) increased linearly with dietary urea level . In Exp . 2, four ruminally and duodenally cannulated steers (557 kg) were fed the diets used in Exp . 1 to evaluate effects of dietary urea on site and extent of digestion . True ruminal OM and starch digestion were increased 25 and 37%, respectively, by .5% urea, but higher urea levels did not differ from .5% . Flows of total N and microbial N to the duodenum were not affected by urea level . In Exp . 3, 100 yearling steers (347 kg) were fed dry-rolled corn finishing diets that contained 10% alfalfa hay as the dietary roughage to evaluate effects of dietary urea level on performance and carcass characteristics . Urea levels were 0, .35, .70, 1.05, or 1.40% urea (DM basis), with no other supplemental N provided . Dry matter intake (P = .10), ADG (P < .05), and G/F (P < .05) increased with intermediate concentrations of urea but decreased with the highest concentration . Regression analysis indicated that the optimal dietary urea level was .5% of DM for ADG and G/F . Urea increased dietary energy utilization but not metabolizable protein supply.

J Anim Sci, 1997 May, 75(5), 1299 - 307
Efficacy of Natuphos in sorghum-based diets of finishing swine; O'Quinn PR et al.; The efficacy of a recombinantly derived microbial phytase (Natuphos 5000, BASF Corp.) was evaluated in sorghum-soybean meal-based diets of finishing swine . During the 50- to 80- and 80- to 118-kg BW intervals, diets contained .40 and .39% plant P, respectively; control diets fed during the two weight intervals were supplemented with .08 and .04% inorganic P from dicalcium phosphate . The all plant-P diets were supplemented with 0, 300, or 500 phytase units (FTU) per kilogram of diet . Supplemental P (P = .09) and phytase (linear, P = .01) increased growth rate but did not affect feed efficiency . Dietary treatment did not affect quantitative carcass traits, CP, fat, or moisture content of the loin or taste panel scores of the cooked loin other than a quadratic decrease (P = .02) in connective tissue amount as phytase supplementation increased . Apparent ileal and total tract digestibilities of DM, GE, and N were not affected (P > .25) by phytase supplementation, whereas ileal and total tract digestibilities of Ca and P increased (P < .05 or P < .01) with increasing phytase supplementation . Ultimate load and ash content of the third and fourth metacarpals and metatarsals and serum P levels increased in response to inorganic P and phytase supplementation . Pig performance, carcass traits, and bone traits were essentially equal for the 300 and 500 FTU/kg treatments . These results show that phytase effectively liberates P in sorghum-based diets, and that 300 FTU/kg (or less) will optimize performance and carcass merit of finishing swine.

J Am Dent Assoc . 1997 May;128(5):648.
Antibiotic use in dentistry . ADA Council on Scientific Affairs; The usefulness of diagnostic tests on pericardial fluid; Department of Internal Medicine, Kansas University Medical Center, Kansas City, USASTUDY OBJECTIVES: To determine the physical, chemical, and cellular characteristics of pericardial fluid in various disease states and to assess their diagnostic accuracies . SETTING: A metropolitan university hospital . DESIGN: Consecutive case series . PATIENTS: One hundred seventy-five hospital patients, aged 1 month to 87 years, who had undergone pericardiocentesis (n = 165) or control subjects who had undergone open heart surgery (n = 10) between 1984 and 1996 . MEASUREMENTS: The appearance of pericardial fluid and results of chemistry tests, cell counts, cytologic studies, Gram's stain, and microbial cultures were obtained by chart review . The etiology of each pericardial fluid sample was determined using prospective diagnostic criteria . RESULTS: Exudates differed from transudates by higher leukocyte counts and ratios of fluid to serum lactate dehydrogenase levels . Fluid glucose levels were significantly less in exudates . Sensitivity for detecting exudates was high for specific gravity > 1.015 (90%), fluid total protein > 3.0 g/dL (97%), fluid to serum protein ratio > 0.5 (96%), fluid lactate dehydrogenase ratio > 0.6 (94%), and fluid to serum glucose ratio < 1.0 (85%) . None of these indicators were specific . Fluid total protein and specific gravity were moderately correlated (r = 0.56) . Fluid cytologic study had a sensitivity of 92% and specificity of 100% for malignant effusion . No other test was diagnostic for a specific etiology . Among infection-associated effusions, culture-positive fluid had more neutrophils, higher lactate dehydrogenase levels, and lower ratios of fluid to serum glucose than culture-negative (parainfective) fluid . CONCLUSIONS: Evaluation of pericardial fluid might be limited to cell count, glucose, protein, and lactate dehydrogenase determinations plus bacterial culture and cytology . While not used routinely, other tests that may be highly specific for particular diseases should be ordered only to confirm a high clinical suspicion.

Urology, 1997 May, 49(5A Suppl), 14 - 40
Interstitial cystitis: a critique of current concepts with a new proposal for pathologic diagnosis and pathogenesis; Elbadawi A; Interstitial cystitis (IC) has continued to be an unresolved problem in clinical urology despite intense investigation over the past 16 or more years . Its etiology and pathogenesis are still undetermined, and its pathologic diagnosis is essentially one of exclusion, with no specific or clear criteria . In this review, current concepts of the etiology/pathogenesis and pathology are critically analyzed, new pathologic observations summarized, and a proposal of neurogenic inflammation as the primary pathogenetic factor is presented in the context of all currently available information . The popular postulate attributing IC to a deficient or defective glycosaminoglycan urothelial surface layer is not substantiated by morphologic, experimental, clinical, or therapeutic observations . Although the consensus seems to discount an infectious etiology, there is sufficient evidence that a microbial factor-short of a bona fide clinical infection-may have a role . Both autoimmunity and mast cell infiltration also appear to have a role, despite the lack of evidence that either is involved as the primary etiologic factor . Claims that the so-called feline urologic syndrome may represent a natural animal model of IC are shaky . As it now stands, there is no natural or induced animal model that duplicates IC as it occurs in humans . No specific or diagnostic light microscopic pathologic features are provided by either routine histopathology or immunohistochemistry . Increasingly, it has been recognized that detrusor mast cell count has little or no diagnostic value . On the other hand, electron microscopy has provided important new observations: (a) presence of mast cells, activated by piecemeal degranulation, in close proximity to intrinsic nerves-particularly in suburothelium: (b) distinctive pathologic changes in urothelium, suburothelium, and muscularis in biopsy samples obtained after diagnostic bladder hydrodistension; (c) constant associated changes in venules, capillaries, and neural elements in the same biopsy samples; and (d) diffuse involvement of bladder wall, with the most evident and profound pathologic changes in posthydrodistension biopsy samples obtained from cystoscopically obvious lesions (glomerulations) . These features are sufficiently distinctive to allow definitive pathologic diagnosis of IC, and provide a firm basis for primary involvement of neurogenic inflammation in its pathogenesis . A proposal is presented regarding the mechanisms invoked by neurogenic inflammation . This proposal revolves around sensory nerve excitation, the release of neuropeptides, and activated differential secretion of potent mast cell mediators . This proposal can account for the heterogeneity and variability of observed pathologic features, and upholds the tacit acceptance of IC as a disease of pluricausal etiology and multifactorial pathogenesis.

Appl Environ Microbiol, 1997 May, 63(5), 1861 - 5
Preparation of GM1 ganglioside with sialidase-producing marine bacteria as a microbial biocatalyst; Fukano Y et al.; This paper describes the preparation of monosialoganglioside GM1 with sialidase-producing marine bacteria as a microbial biocatalyst . A new sialidase-producing bacterium, identified tentatively as Pseudomonas sp . strain YF-2, was isolated from seawater by enrichment culture with ganglioside as the sole source of carbon . When YF-2 was cultured in a synthetic medium containing crude bovine brain gangliosides at 25 degrees C for 3 days, 80 to 90% of the gangliosides were converted to GM1 . GM1 was then purified from the supernatant of YF-2 culture by C18 reverse-phased chromatography, followed by DEAE-Sephadex A25 anion-exchange chromatography . In a typical experiment, 178 mg of highly purified GM1 was obtained from 500 mg of the crude ganglioside fraction . The GM1 induced neurite outgrowth of neuroblastoma Neuro2a cells at a concentration of 33 to 100 microM in the presence of fetal calf serum . Sialidase was purified 33-fold with 13.3% recovery from the culture supernatant of YF-2 . The purified enzyme hydrolyzed polysialogangliosides to produce GM1 but did not act on GM1 . It was therefore concluded that polysialogangliosides in the culture of strain YF-2 were converted to GM1 by this sialidase.

Clin Infect Dis, 1997 May, 24(5), 945 - 50
Prospective analysis of genital ulcer disease in Brooklyn, New York; Dillon SM et al.; We prospectively studied 82 men and women with first episodes of genital ulceration . By using newer diagnostic techniques, a definite microbial etiology of 84 infections in 65 of the 82 patients evaluated was found . There were 33 cases of definite primary syphilis, 27 of definite chancroid, and 24 of definite genital herpes simplex . Conclusive evidence of more than one microbial etiology was found for 19 (23%) of the patients . Simultaneous primary syphilis and chancroid was the third most common ulcer infection . This finding underscores the need for both clinical suspicion of multiple infections in patients with genital ulcers and comprehensive testing for all suspicious etiologies.

Hepatology, 1997 May, 25(5), 1255 - 7
Association of seropositivity for hepatitis viruses and aplastic anemia in Thailand; Issaragrisil S et al.; Aplastic anemia is more common in the Orient than in western countries, with an incidence in Thailand that is 2- to 3-fold higher than in Europe . Aplastic anemia after hepatitis is a well characterized clinical entity, and clinical hepatitis is also prevalent in the Far East . We performed a prospective case-control study to determine risk factors for aplastic anemia in Bangkok and two rural regions during 1989 to 1994 . A total of 375 cases were identified, along with 1,174 hospital controls matched for age and sex . Historical data were collected by trained interviewers . Sera from a subset of cases (N = 177) and controls (N = 183) were tested for antibodies to hepatitis viruses A, B, and C and hepatitis B surface antigen . There was no evidence of association of aplastic anemia with hepatitis B or hepatitis C . Previous exposure to hepatitis A, as determined by immunoglobulin G (IgG) seropositivity, was significantly associated with aplastic anemia: the relative risk adjusted for confounding was 2.9 (95% confidence interval 1.2-6.7) . The same association also existed for persons under age 25 years, in whom the prevalence of hepatitis A IgG was lower than in the total population . However, no patients showed evidence of recent infection with hepatitis A (immunoglobulin M {IgM} seropositivity) . These results indicate that exposure to a hepatitis virus is a risk indicator for aplastic anemia in Thailand, and while itself unlikely to be etiologic, hepatitis A may be a surrogate marker for another enteric microbial agent.

Cancer Res, 1997 May 1, 57(9), 1710 - 6
Irreversible and reversible topoisomerase II DNA cleavage stimulated by clerocidin: sequence specificity and structural drug determinants; Binaschi M et al.; In contrast to other topoisomerase II poisons, the microbial terpenoid clerocidin was shown to stimulate irreversible topoisomerase II-mediated DNA cleavage . To establish the structural determinants for drug activity, in this study we have investigated intensity patterns and sequence specificity of clerocidin-stimulated DNA cleavage using 5'-end 32P-labeled DNA fragments . At a majority of the sites, clerocidin-stimulated cleavage did not revert upon NaCl addition; nevertheless, at some sites, cleavage completely reverted . Statistical analyses showed that drug-preferred bases were different in the two cases: guanine and cytosine were highly preferred at position -1 at irreversible and reversible sites, respectively . These results demonstrated that cleavage irreversibility was site selective and required a guanine at the 3' end of the cut . Further experiments revealed that some irreversible sites showed an abnormal electrophoretic mobility in sequencing gels with respect to cleaved bands generated by 4-(9-acridinylamino)methanesulfon-m-anisidide, suggesting a chemical alteration of the DNA strand . Interestingly, the ability to stimulate irreversible cleavage progressively decreased over time when clerocidin was stored in ethanol . Under these conditions, nuclear magnetic resonance measurements demonstrated that the drug underwent structural modifications that involved the C-12-C-15 side chain . Thus, the results indicate that a specific moiety of clerocidin may react with the DNA (guanine at -1) in the ternary complex, resulting in cleavage irreversibility and in altered DNA mobility in sequencing gels.

Mol Cells, 1997 Apr 30, 7(2), 192 - 9
Identification of putative phosphoinositide-specific phospholipase C genes in filamentous fungi; Jung OJ et al.; Five putative phosphoinositide-specific phospholipases C (PLC) genes were identified in three species of filamentous fungi . Using polymerase chain reaction with degenerate oligonucleotide primers, gene fragments encoding amino acid sequences homologous to PLCs of mammals and other organisms were amplified: one sequence from Botryotinia fuckeliana, one from Aspergillus nidulans, and three from Neurospora crassa . The molecular cloning and sequencing of a putative PLC gene (BCPLC1) from B . fuckeliana showed that it encoded a polypeptide containing X and Y domains, the two conserved regions found in all known PLCs . The hypothetical gene product of BCPLC1 was of delta type in its primary structural organization . The identification of three PLC genes in N . crassa shows that multiple PLC isozymes also occur in microbial eukaryotes.

J Biol Chem, 1997 Apr 18, 272(16), 10389 - 95
Identification and characterization of a novel Ets-2-related nuclear complex implicated in the activation of the human interleukin-12 p40 gene promoter; Ma X et al.; Interleukin-12 (IL-12) is a proinflammatory cytokine produced by antigen-presenting cells in response to many microbial infections . IL-12 plays an important role in the generation of T helper type-1 cells, which favor cell-mediated immune response . IL-12 is composed of two different subunits, p40 and p35, whose expression can be regulated concomitantly or differentially . Monocytic cells, the major producers of IL-12, can be primed by interferon-gamma (IFN-gamma) to produce optimal amounts of IL-12 in response to LPS stimulation as a consequence of bacterial infection . The priming effect is exerted primarily at the transcriptional level on the p40 promoter in conjunction with the effects of LPS, possibly by inducing specific transcription factors, which individually have no direct effect but which cooperatively can activate the promoter . We examined in detail one of these DNA-protein interactions observed around an Ets-2 element situated at -211/-207 of the p40 promoter, which is known to be a functionally critical site . This region interacts with a nuclear complex termed F1 that appears to be highly inducible by either IFN-gamma treatment for 16 h or lipopolysaccharide stimulation for 8 h . F1 binding to the Ets-2 site requires a considerable amount of spacing around the Ets-2 site, as revealed by gel mobility shift and in vitro methylation assays . Supershift experiments and DNA affinity purification indicated that both Ets-2 and a novel, antigenically related protein with an approximate molecular mass of 109 kDa are part of the F1 complex, together with additional components including IRF-1 and c-Rel . This novel protein is designated GLp109 for its inducibility by IFN-gamma or lipopolysaccharide . Its possible role in the activation of the IL-12 p40 promoter is discussed.

J Theor Biol, 1997 Apr 7, 185(3), 367 - 72
A mathematical model to determine the optimal number of fragments for comparison of bacterial chromosomic macrorestriction patterns; Mendez-Alvarez S et al.; To our knowledge, although comparison of chromosomic macrorestriction patterns has become one of the most feasible molecular tools of the current microbial taxonomy, a mathematical approach to optimize the choice of a restriction enzyme among the endonucleases tested for such comparison has not been previously described . The coincidence of restriction patterns for two tested bacterial strains with this chosen endonuclease will ensure a high genetic relatedness between them . We report a mathematical model to determine the probability of hazardously obtaining a particular chromosomic macrorestriction pattern by PFGE and to calculate the optimal number of fragments for its comparison . The model presented allows us to determine the optimal number of fragments in order to compare chromosomic restriction patterns . The model calculates this values as a function of the chromosome size and the restriction site length . The model is not useful for choosing a restriction enzyme previous to experimental steps, but as a tool for the choice of the restriction enzyme that yields the lowest probability of hazardously obtaining coincidences of chromosomic patterns . The applicability of this model has been exemplified by determining the optimal number of fragments for some well-characterized bacteria and by comparing these values with those that have been experimentally used.

Nervenarzt, 1997 Apr, 68(4), 292 - 7
{Infection: impaired consciousness as the initial symptom . Clinical and pathophysiologic aspects of septic encephalopathy}; Schwarz S et al.; Septic encephalopathy (SE) is present in up to 70% of all patients with sepsis . In some cases, SE may proceed other parameters of sepsis . Loss of consciousness to a various extent is the leading symptom . CSF findings and CCT are usually unremarkable . EEG is a sensitive parameter to monitor SE . EEG-changes deteriorate in correspondence to the degree of SE . If sepsis can be treated successfully, clinical and electrophysiological signs are completely reversible . SE has a complex etiology . Bacterial endotoxins and other microbial products trigger the release of a multitude of mediators of sepsis . Due to liver dysfunction in sepsis, the brain neurotransmitter profile may be deranged . Other etiological factors include bacteriemia, liver or renal dysfunction, fluid and electrolyte imbalance, hypoglycemia and drug effects . Due to the prognostic significance of early adequate treatment, recognition of SE as a possible initial sign may be crucial for patients with sepsis.

Biol Trace Elem Res, 1997 Apr, 57(1), 1 - 8
A longitudinal study of unsaturated iron-binding capacity and lactoferrin in unstimulated parotid saliva; Mukherjee S et al.; Availability of iron is one important nutritional parameter for microbial growth in saliva . This longitudinal study measured the diurnal and day-to-day variations in the total iron (TI), total iron-binding capacity (TIBC), unsaturated iron-binding capacity (UIBC), and lactoferrin (LF) in unstimulated human parotid saliva . Saliva was collected from 15 young male subjects in the morning and afternoon hours each day for five consecutive days . The TI and TIBC were determined by flameless atomic absorption spectroscopy, and UIBC was determined by subtraction of TI from TIBC . The LF was determined by "sandwich" enzyme-linked immunosorbent assay (ELISA) . One peripheral blood sample of each subject was also analyzed for TI, TIBC, and ferritin . The results showed no significant diurnal or day-to-day variation of TI, TIBC, UIBC, or LF in saliva for most subjects . However, significant between-subject variations were observed for most parameters . Variations ranged from subjects with constantly positive UIBC values to subjects with constantly negative UIBC values . The relationship between the LF values and the TI and TIBC values suggests that other iron-binding protein(s) are present in saliva . Also, saliva had significantly lower TIBC values than serum . This finding indicated that iron may be easily available in saliva . However, further studies are required to determine the relationship between UIBC value of saliva and oral and dental diseases, and also to detect the presence of other iron-binding proteins in saliva.

Chem Biol, 1997 Apr, 4(4), 279 - 86
Stevastelins, a novel group of immunosuppressants, inhibit dual-specificity protein phosphatases; Hamaguchi T et al.; BACKGROUND: Since the molecular target of the immunosuppressive reagents FK506 and cyclosporin A was revealed to be protein phosphatase PP2B (calcineurin), many researchers have been screening the protein phosphatase inhibitors from microbial metabolites to develop new immunosuppressive reagents . We isolated stevastelin B, which is composed of valine, threonine, serine and 3,5-dihydroxy-2,4-dimethyl stearic acid, and stevastelin A, which is a sulphonylated derivative of stevastelin B . To understand the action mechanism of stevastelins A and B, we synthesized a series of stevastelin derivatives and investigated their structure-activity relationships . RESULTS: A series of stevastelin derivatives have been systematically synthesized . Stevastelin B inhibited gene expression that is dependent on interleukin-2 (IL-2) or IL-6 promoters in situ, but it had no inhibitory activity against any protein phosphatases in vitro . In contrast, stevastelin A, which is a sulphonylated derivative of stevastelin B, inhibited the phosphatase activity of a dual-specificity phosphatase, VH1-related human protein (VHR), in vitro, but it had no inhibitory activity against gene expression or cell-cycle progression in situ . CONCLUSIONS: Stevastelin B is a novel immunosuppressant . It inhibited IL-2 or IL-6 dependent gene expression but did not inhibit the phosphatase activity of calcineurin . The structure-activity relationships show that the acidic functional group on the threonine residue and the stearic acid moiety in the stevastelin molecule are important for inhibitory effects on the dephosphorylation activity of VHR in vitro . Stevastelin B might be sulphonylated or phosphorylated after incorporation into the target cell, and then it interacts with protein tyrosine phosphatases and regulates cell-cycle progression.

Aliment Pharmacol Ther, 1997 Apr, 11(2), 317 - 22
Randomized study comparing omeprazole plus amoxycillin versus omeprazole plus clarithromycin for eradication of Helicobacter pylori; Spinzi G et al.; BACKGROUND: Dual therapy with omeprazole plus amoxycillin or with omeprazole plus clarithromycin has been proposed for eradication of Helicobacter pylori . The main problem is the great variability in the rate of eradication . METHODS: A group of 287 consecutive patients with active peptic ulcers and H . pylori infections were admitted to a prospective, randomized, multicentre study, to be given omeprazole 20 mg b.d . plus either amoxycillin 1 g b.d . or clarithromycin 500 mg t.d.s . for 2 weeks . Cure was defined as the absence of H . pylori infection, 4-6 weeks after completing anti-microbial therapy, assessed by urease activity and histology of antral and body gastric biopsies . RESULTS: The bacteria were eradicated in 68/143 patients (48%) treated with amoxycillin and omeprazole and 70/144 patients (49%) treated with clarithromycin and omeprazole (intention-to-treat analysis) . The ulcers were healed in 118/127 patients (93%) treated with amoxycillin and in 115/123 (94%) of those treated with clarithromycin . Undesirable effects were rare with both treatments . CONCLUSIONS: Combined treatment with omeprazole plus either amoxycillin or clarithromycin produced a high percentage of short-term healing of ulcers and was well tolerated, but is not useful as first-line anti-Helicobacter pylori treatment.

Biosci Biotechnol Biochem, 1997 Apr, 61(4), 609 - 14
Microbial extracellular glycolipid induction of differentiation and inhibition of the protein kinase C activity of human promyelocytic leukemia cell line HL60; Isoda H et al.; The biological activities of 7 microbial extracellular glycolipids including mannosylerythritol lipid (MEL)-A, MEL-B, polyol lipid (PL), rhamnolipid (RL), sophorose lipid (SL), succinoyl trehalose lipid (STL)-1, and STL-3 were investigated . All glycolipids except for RL were found to induce cell differentiation instead of cell proliferation in the human promyelocytic leukemia cell line HL60 . To identify the differentiation direction of the induced cells, the leukocyte esterase activities were cytologically investigated, and the results showed that MEL-A, MEL-B, and PL induced HL60 to differentiate into granulocytes, while SL, STL-1, and STL-3 induced differentiation into monocytes . The 6 effective glycolipids also increased nitroblue tetrazolium (NBT) reducing ability, which is a common differentiation-associated characteristic in monocytes and granulocytes . Furthermore, it was also observed that these 6 glycolipids inhibited the activity of phospholipid- and Ca(2+)-dependent protein kinase . Additionally, the 6 effective glycolipids also induced the human myelogenous leukemia cell line K562 and the human basophilic leukemia cell line KU812 to differentiate into monocytes, granulocytes, and megakaryocytes.

Biosci Biotechnol Biochem, 1997 Apr, 61(4), 592 - 8
Purification, characterization, and cDNA cloning of a novel alpha-galactosidase from Mortierella vinacea; Shibuya H et al.; A novel alpha-galactosidase, designated alpha-galactosidase II, was isolated from the culture filtrate of Mortierella vinacea . The molecular size of the purified enzyme estimated by gel filtration was 60 kDa, which agreed with that, 51-62 kDa, estimated by SDS-PAGE . The enzyme was thermolabile at neutral pH, but the addition of BSA to the enzyme solution at the concentration of 0.01% increased its stability considerably . The enzyme appears to be novel because it showed a distinct substrate specificity from other microbial alpha-galactosidases on galactomanno-oligosaccharides, prepared from galactomannan, that is, the enzyme liberated not only side-chain alpha-galactosyl residue from 6(3)-mono-alpha-D-galactopyranosyl-beta-1,4-D-mannotetraose but also terminal alpha-galactosyl residue from 6(3)-mono-alpha-D-galactopyranosyl-beta-1,4-D-mannotriose . In addition, the enzyme acted on galactomannans effectively . alpha-Galactosidase II cDNA was cloned and its nucleotides sequenced . The deduced amino acid sequence showed that the mature enzyme consisted of 376 amino acid residues with a molecular mass of 41,334 Da . The derived amino acid sequence of the enzyme showed 31-49% sequence similarity with those of alpha-galactosidases from other origins.

Microbiology, 1997 Apr, 143 ( Pt 4), 1451 - 9
Methylosphaera hansonii gen . nov., sp . nov., a psychrophilic, group I methanotroph from Antarctic marine-salinity, meromictic lakes; Bowman JP et al.; Methanotrophic bacteria were enumerated and isolated from the chemocline and surface sediments of marine-salinity Antarctic meromictic lakes located in the Vestfold Hills, Antarctica (68 degrees S 78 degrees E) . Most probable number (MPN) analysis indicated that at the chemocline of Ace Lake the methanotroph population made up only a small proportion of the total microbial population and was sharply stratified, with higher populations detected in the surface sediments collected at the edge of Ace Lake and Burton Lake . Methanotrophs were not detected in Pendant Lake . Only a single phenotypic group of methanotrophs was successfully enriched, enumerated and isolated into pure culture from the lake samples . Strains of this group were non-motile, coccoidal in morphology, did not form resting cells, reproduced by constriction, and required seawater for growth . The strains were also psychrophilic, with optimal growth occurring at 10-13 degrees C and maximum growth temperatures of 16-21 degrees C . The ribulose monophosphate pathway but not the serine pathway for incorporation of C1 compounds was detectable in the strains . The guanine plus cytosine (G + C) content of the genomic DNA was 43-46 mol% . Whole-cell fatty acid analysis indicated that 16:1 omega 8c (37-41%), 16:1 omega 6c (17-19%), 16:1 omega 7c (15-19%) and 16:0 (14-15%) were the major fatty acids in the strains . 16s rDNA sequence analysis revealed that the strains form a distinct line of descent in the family Methylococcaceae (group I methanotrophs), with the closest relative being the Louisiana Slope methanotrophic mytilid endosymbiont (91.8-92.3% sequence similarity) . On the basis of polyphasic taxonomic characteristics the Antarctic lake isolates represent a novel group I methanotrophic genus with the proposed name Methylosphaera hansonii (type strain ACAM 549).

J Periodontal Res, 1997 Apr, 32(3), 326 - 34
Bacterial metabolites sodium butyrate and propionate inhibit epithelial cell growth in vitro; Pollanen MT et al.; The structural and functional barrier preventing the free advancement of microbial plaque subgingivally along the tooth surface is formed by the junctional epithelial (JE) cells directly attached to the tooth (DAT cells) . The mechanism leading to degeneration of the DAT cells is not known . In the present study we examined the possible role of short chain fatty acids (SCFAs) on epithelial cells by making use of 2 epithelial cell cultures (HaCaT and ERM) and an explant culture model of human JE . The SCFAs butyrate and propionate were used in concentrations found in human plaque and gingival crevicular fluid (0.25-16.0 mM) . The SCFAs had no effect on primary cell adhesion nor on the epithelial attachment apparatus (EAA) . By contrast, even 0.25 mM of butyrate significantly retarded epithelial cell growth . Similar effects with propionate were first observed at concentrations higher than 1.0 mM . The retardation of epithelial cell growth was found to be due to inhibition of cell division . Furthermore, after butyrate treatment dense accumulations of intermediate filaments and cytoplasmic vacuolization were characteristically seen in cells adjacent to cells of normal appearance . This suggests that some cells of the growing epithelial cell population are more sensitive to the SCFAs than others, and agrees with previous reports on the DAT cells of periodontally-involved teeth in vivo . The results suggest that SCFAs are microbial factors that play a role in the initiation and progression of periodontal pocket formation by impairing epithelial cell function rather than having a direct effect on the EAA.

Biomaterials, 1997 Apr, 18(8), 635 - 41
Physico-chemical properties of a rifampicin-releasing polydimethylsiloxane shunt; Schierholz JM; Infection of implanted polymeric devices is a major problem in modern medicine . Silicone shunts were modified in order to prevent microbial colonization by incorporating rifampicin . The release mechanism and the altered properties of the silicone were studied . Release rates of rifampicin out of the polymeric shunt materia were measured in vitro for up to 60 d . For high velocity of rifampicin in the polymeric matrix and long-lasting controlled release rates, high compatibility of polymer and drug was required . Compatibility and therefore miscibility of drug and polymer were estimated by reduced solubility and cohesion energy densities (Hansen parameter, solubility parameter delta) . Mechanical properties of the polymer were influenced by incorporation of small drug amounts, characterized by stress-strain curves . Differential scanning calorimetry (DSC) measurements suggested thermodynamically controlled interaction of the macromolecules with the incorporated substance . The physico-chemical state of the drug in the internal phase and the surface of the polymer was studied by scanning electron micrography (SEM), showing homogeneous molecular dispersion of the drug in the polymeric material as well as crystalline structures on the surface.

J Hepatol, 1997 Apr, 26(4), 839 - 44
Early microbiologic diagnosis of spontaneous bacterial peritonitis with BacT/ALERT; Ortiz J et al.; BACKGROUND/AIMS: Inoculation of ascitic fluid into conventional blood culture bottles is more sensitive than conventional culture in the diagnosis of spontaneous bacterial peritonitis . BacT/ALERT is an automated colorimetric microbial detection system that has been shown to be faster than conventional blood culture bottles in the diagnosis of bacteremia . The aim of the study was to compare the BacT/ALERT system with the conventional culture and the conventional blood culture bottles method in the diagnosis of spontaneous bacterial peritonitis . METHODS: All the ascitic fluid samples from patients with cirrhosis hospitalized in our Department between September 1992 and May 1994 (n=1032) were prospectively evaluated . In all cases, an aliquot of ascitic fluid was sent for Gram's stain and conventional culture, and 20 ml were inoculated at the bedside into blood culture bottles: 10 ml into conventional blood culture bottles and 10 ml into BacT/ALERT . RESULTS: Thirty ascitic fluid infections (23 spontaneous bacterial peritonitis and 7 neutrocytic ascites) and 20 bacterascites were diagnosed . Conventional culture was positive in 10/30 ascitic fluid infections (33.3%), conventional blood culture bottles in 22/30 (73.3%) (p<0.01 compared to conventional culture) and BacT/ALERT in 20/30 (66.6%) (p<0.05 compared to conventional culture, pNS compared to conventional blood culture bottles) . The time elapsed for culture positivity was 43.4+/-34.2 h for conventional blood culture bottles and 13.3+/-9.2 h for BacT/ALERT (p<0.001) . Thirteen of the 23 cases of spontaneous bacterial peritonitis (56.5%) were detected within the first 12 h with BacT/ALERT, as compared to only three (13%) with conventional blood culture bottles (p<0.03) . CONCLUSION: The automated system BacT/ALERT provides an earlier microbiologic diagnosis of spontaneous bacterial peritonitis than conventional blood culture bottles with similar sensitivity.

J Immunol, 1997 Apr 1, 158(7), 3511 - 20
Vaccine-specific antibody responses induced by HIV-1 envelope subunit vaccines; Pincus SH et al.; The first generation of candidate vaccines to prevent HIV infection consisted of recombinant envelope proteins (Env, gp120, and gp160) derived from a single laboratory strain of HIV, designated IIIB/LAV, but produced with different expression systems . In this study we examined the fine specificity of the human Ab response to each vaccine and compared them to the responses of laboratory workers infected with the same strain of HIV . The best responders from each vaccine protocol were studied and compared . Detailed comparisons of the fine specificity of the Ab response were possible because all immunologic assays were performed using homologous recombinant proteins, peptides, and virus stocks . Although the total amounts of anti-Env Ab were comparable, the groups exhibited significant differences in epitope specificity, avidity, and functional capacity of the Ab response . The data demonstrate that the form of the immunogen (e.g., live virus or recombinant protein) is important in determining the quality of the Ab response . Conclusions are also drawn regarding characteristics of the anti-HIV-neutralizing Ab response . These studies represent one of the most detailed analyses of the human Ab response to any Ag and have implications for the development of vaccines for HIV as well as for other microbial pathogens.

J Anim Sci, 1997 Apr, 75(4), 904 - 9
Influence of flake density on the comparative feeding value of a barley-corn blend for feedlot cattle; Zinn RA et al.; Ninety-six medium-frame crossbred steers (209 kg) were used in an 86-d feeding trial . Dietary treatments consisted of a 92% concentrate diet containing 76.15% (DM basis) grain as 1) steam-flaked barley (SFB), flake density (FD) = .26 kg/L; 2) blend of 2/3 barley and 1/3 corn steam-flaked (SFBLEND), FD = .36 kg/L; 3) SFBLEND, FD = .31 kg/L; 4) SFBLEND, FD = .26 kg/L . There were no treatment effects (P > .10) on growth performance of feedlot steers or NE value of the diet . Weight gain averaged 1.46 kg/d . Feed efficiency was in close agreement (101%) with expected values based on observed DMI and tabular dietary NE values . Treatment effects on characteristics of ruminal and total tract digestion were evaluated using four Holstein steers (280 kg) with cannulas in the rumen and proximal duodenum in a 4 x 4 Latin square design . Ruminal digestibility of OM (P < .01), starch (P < .01), and feed N (P < .10) increased, and ruminal N efficiency (duodenal nonammonia N/N intake, P < .01) decreased (linear component) with decreasing FD . Net microbial N flow to the small intestine was greater (P < .05) for SFB than for the SFBLEND . Total tract digestion of OM (P < .01), starch (P < .05), and DE (P < .05) was greater for the SFBLEND than for SFB . There were no treatment effects (P < .10) on postruminal and total tract digestibility of N . We conclude that blending barley and corn before flaking will have very little impact on the feeding value of the grains compared with flaking the grains separately.

Pediatr Infect Dis J, 1997 Apr, 16(4), 381 - 5
Frequency of low level bacteremia in infants from birth to two months of age; Kellogg JA et al.; BACKGROUND: The frequency of low level bacteremia (< or = 10 colony-forming units/ml) in infants from birth to 2 months of age and the optimal volume of blood and number of blood cultures to be collected have not been well-documented . During 1991 guidelines at this hospital for collection of blood for culture from these infants were revised . METHODS: Blood from each infant with suspected bacteremia was usually inoculated into an Isolator 1.5 Microbial Tube (1.5 ml of blood) and a bottle of anaerobic broth (0.5 to 3.0 ml of blood) . The use of a second Isolator tube and the total blood volume recommended for culture (2 to 6 ml) depended on the weight and total blood volume of each infant . RESULTS: Forty-four bacterial pathogens were recovered from the blood of 40 (2.5%) of 1589 infants . Of 34 infants from whose blood the concentration of pathogens could be determined, 23 (68%) had low level bacteremia . Of 50 isolates of pathogens recovered from Isolator cultures, 32 (64%) were detected in counts of < or = 10 colony-forming units/ml . When 2 or 3 blood culture devices were inoculated with a total of 2 to 6 ml of blood from each infant, significantly more cases of bacteremia were detected (34 (3.0%) of 1126 infants had positive blood cultures) than when only one culture device containing < or = 1.5 ml of blood was used (2 (0.5%) of 398 infants had positive blood cultures; P = 0.008) . However, when 4 or more culture devices were inoculated with a total of > 6 ml of blood from each infant (5 (7.7%) of 65 infants had positive blood cultures), the difference in recovery of pathogens compared with the culturing of from 2 to 6 ml of blood per infant was not significant (P = 0.089) . CONCLUSIONS: Low level bacteremia was common in our infants' patient population . The culturing of up to 6 ml of blood which represented up to 4.5% of an infant's total blood volume was required for detection of the pathogens.

Int J Food Microbiol, 1997 Apr 1, 35(2), 187 - 93
Electronic nose for microbial quality classification of grains; Jonsson A et al.; The odour of grains is in many countries the primary criterion of fitness for consumption . However, smelling of grain for quality grading should be avoided since inhalation of mould spores or toxins may be hazardous to the health and determinations of the off-odours are subjective . An electronic nose, i.e . a gas sensor array combined with a pattern recognition routine might serve as an alternative . We have used an electronic nose consisting of a sensor array with different types of sensors . The signal pattern from the sensors is collected by a computer and further processed by an artificial neural network (ANN) providing the pattern recognition system . Samples of oats, rye and barley with different odours and wheat with different levels of ergosterol, fungal and bacterial colony forming units (cfu) were heated in a chamber and the gas in the chamber was led over the sensory array . The ANN could predict the odour classes of good, mouldy, weakly and strongly musty oats with a high degree of accuracy . The ANN also indicated the percentage of mouldy barley or rye grains in mixtures with fresh grains . In wheat a high degree of correlation between ANN predictions and measured ergosterol as well as with fungal and bacterial cfu was observed . The electronic nose can be developed to provide a simple and fast method for quality classification of grain and is likely to find applications also in other areas of food mycology.

FEMS Microbiol Lett, 1997 Apr 1, 149(1), 93 - 8
H4 histone in the macronucleus of Blepharisma japonicum (Protozoa, Ciliophora, Heterotrichida); Salvini M et al.; Two clones, obtained by polymerase chain reaction from macronuclear DNA of the unicellular ciliated protist Blepharisma japonicum, were isolated and sequenced . They correspond to fragments of two different putative H4 histone genes . The existence of multiple H4 histone genes was also suggested by Southern blot hybridisation experiments employing one of the obtained clones as a probe . Two B . japonicum H4 protein fragments, which were directly sequenced, show differences in the amino acid sequences too . The comparison of the obtained B . japonicum H4 partial amino acid sequences with each other, and with H4 from other ciliates and from representative microbial and multicellular organisms, highlights the larger histone heterogeneity of lower eukaryotes compared to that observed in higher organisms.

Mol Plant Microbe Interact, 1997 Apr, 10(3), 326 - 38
A peroxidase gene promoter induced by phytopathogens and methyl jasmonate in transgenic plants; Curtis MD et al.; The expression of two closely related peroxidase isogenes, Shpx6a and Shpx6b, of the legume Stylosanthes humilis was studied using isogene-specific reverse transcriptase PCR techniques . Results indicated that transcripts of both genes were rapidly induced following inoculation with the fungal pathogen Colletotrichum gloeosporioides, wounding and treatment with the defense regulator methyl jasmonate (MeJA) . In contrast treatment of leaves of S . humilis with abscisic acid (ABA) and salicylic acid (SA) did not induce transcripts of either isogene . A genomic clone containing the Shpx6b gene was isolated and 594 bp of 5' sequence upstream of the translation start was fused in frame to the coding region of the uidA reporter gene and introduced into tobacco . Expression from the Shpx6b promoter in transgenic plants was determined by histochemical staining and quantitative assays of beta-glucuronidase (GUS) . In transgenic tobacco, GUS expression was detected in cotyledons, vascular cells of young leaves, anthers, pollen, and the stigma and style . Wounding of the tobacco plants produced very localized GUS staining . Much more extensive staining for GUS was observed following inoculation of tobacco leaves with conidia of the fungal pathogen Cercospora nicotianae and the inoculation of wound sites with mycelium of the Oomycete pathogen Phytophthora parasitica var . nicotianae . Treatment of mature leaves with methyl jasmonate induced GUS activity while treatment with ABA, SA, and H2O2 had no effect . A similar strong induction of GUS activity was measured in young transgenic seedlings germinated on MeJA while some, but much weaker, induction of GUS activity was observed in seedlings treated with SA . The sequence of the promoter contained motifs homologous to putative cis elements in other plant genes responsive to MeJA . The Shpx6b gene is the first plant peroxidase gene shown to be induced by both microbial pathogens and MeJA and its promoter will be useful for investigations of signaling processes during fungal infection and for the expression of foreign gene products at infection sites.

Curr Opin Immunol, 1997 Apr, 9(2), 228 - 32
Generation of antibody diversity in rabbits; Knight KL et al.; Most rabbit B lymphocytes use the same VH gene in V(D)J gene rearrangements and undergo somatic diversification by gene conversion and hypermutation . Recent experiments have shown that V(D)J genes in essentially all rabbit B cells diversify shortly after birth and that this diversification occurs in the gut-associated lymphoid tissue . Still to be determined is whether this diversification is developmentally programmed or is driven by exogenous microbial antigens.

Am J Med Sci, 1997 Apr, 313(4), 236 - 8
Behçet's-like syndrome associated with idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large population of TCR alpha beta+ CD4- CD8- T cells; Venzor J et al.; Herein we report a patient with Behcet's like syndrome, idiopathic CD4+ T-lymphocytopenia, opportunistic infections, and a large polyclonal population of TCR alpha beta + CD4- CD8- T cells . Microfluorimetric analysis of peripheral blood mononuclear cells revealed CD4+ T-cell counts of 10 +/- 5/mm3 . The CD3+ T cells were 99% TCR alpha beta +, of which 74 +/- 5% were CD4- CD8- . No clonal populations were detected by southern analysis for T-cell receptor V beta gene rearrangements . No evidence of human immunodeficiency virus infection was present, although nocardia, candida, pneumocystis, cytomegalovirus, and herpes infections were documented . The concomitant presence of opportunistic infections and a large population of TCR alpha beta + CD4- CD8- T cells suggests a pathogenic association and an intense immune response to microbial lipid or lipoglycan antigens presented in the context of CD1 molecules . This case demonstrates the potential for idiopathic CD4+ T-lymphocytopenia to occur in Behcet's-like syndrome with lethal consequences.

Appl Environ Microbiol, 1997 Apr, 63(4), 1441 - 8
A novel delta-subdivision proteobacterial lineage from the lower ocean surface layer; Wright TD et al.; A small-subunit ribosomal RNA (16S rRNA) gene lineage (SAR324) affiliated with the delta-subdivision of the class Proteobacteria (DP) was discovered in a 16S rRNA gene clone library prepared from a water sample collected from 250 m in the western Sargasso Sea . This clone library of nearly full-length amplicons of bacterial 16S rRNA genes has been the subject of previous studies aimed at identifying bacteria that inhibit the lower ocean surface layer . The novel lineage was identified by randomly sequencing clones that did not hybridize to oligonucleotide probes specific for several abundant bacterioplankton groups identified in previous studies . Phylogenetic analysis indicated that SAR324 was most closely affiliated with the DP, although it showed no specific relationship to any DP 16S rRNA genes in databases . Eight of the clones in the library of 148 clones were identified as members of the SAR324 lineage by hybridization to an oligonucleotide probe specific for SAR324 . Subsequent hybridizations showed that the SAR324 group is stratified in the lower surface layer of both the Atlantic and Pacific Oceans, with maxima between 160 and 500 m . The repeated discovery of sequences belonging to different gene clusters with similar distributions in this region of the water column suggests that microbial communities in the lower surface layer may be functionally specialized.

Appl Environ Microbiol, 1997 Apr, 63(4), 1375 - 81
Seasonal distributions of dominant 16S rRNA-defined populations in a hot spring microbial mat examined by denaturing gradient gel electrophoresis; Ferris MJ et al.; Denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rRNA gene segments was used to examine the distributions of bacterial populations within a hot spring microbial mat (Octopus Spring, Yellowstone National Park) . Populations at sites along the thermal gradient of the spring's effluent channel were surveyed at seasonal intervals . No shift in the thermal gradient was detected, and populations at spatially or temperature-defined sites exhibited only slight changes over the annual sampling period . A new cyanobacterial 16S rRNA sequence type was detected at temperatures from 63 to 75 degrees C . A new green nonsulfur bacterium-like sequence type was also detected at temperatures from 53 to 62 degrees C . Genetically unique though closely related cyanobacterial and green nonsulfur bacterium-like populations were successively distributed along the thermal gradient of the Octopus Spring effluent channel . At least two cyanobacterial populations were detected at each site; however, a limited ability to detect some cyanobacterial populations suggests that only dominant populations were observed.

Appl Environ Microbiol, 1997 Apr, 63(4), 1367 - 74
Population structure and physiological changes within a hot spring microbial mat community following disturbance; Ferris MJ et al.; The influence of disturbance on a hot spring cyanobacterial mat community was investigated by physically removing the top 3.0 mm, which included the entire cyanobacterial layer . Changes in 16S rRNA-defined populations were monitored by denaturing gradient gel electrophoresis analysis of PCR-amplified 16S rRNA gene segments . Some previously absent cyanobacterial populations colonized the disturbed areas, while some populations which were present before the disturbance remained absent for up to 40 days . Changes in physiological activity were measured by oxygen microelectrode analyses and by 14CO2 incorporation into cyanobacterial molecular components . These investigations indicated substantial differences between the disturbed and undisturbed mats, including an unexplained light-induced oxygen consumption in the freshly exposed mat, increased carbon partitioning by phototrophs into growth-related macromolecules, bimodal vertical photosynthesis profiles, and delayed recovery of respiration relative to photosynthesis.

Proc Natl Acad Sci U S A, 1997 Apr 1, 94(7), 3284 - 9
Peptide-induced nasal tolerance for a mycobacterial heat shock protein 60 T cell epitope in rats suppresses both adjuvant arthritis and nonmicrobially induced experimental arthritis; Prakken BJ et al.; Adjuvant arthritis (AA) can be induced in Lewis rats by immunization with mycobacterial antigens . Passive transfer of a T cell clone recognizing the 180-188 amino acid sequence in mycobacterial heat shock protein 60 (hsp60) was found to induce AA . In the present study, we investigated whether tolerance was obtained for this AA-associated T cell epitope after intranasal or s.c . administration of a peptide containing this epitope . Two 15-mer peptides containing the mycobacterial hsp60 sequences 176-190 and 211-225 were used; 176-190 contained the T cell epitope 180-188, which was recognized by the arthritogenic T cell clone A2b and was the immunodominant hsp60 T cell epitope after induction of AA, and 211-225 contained a T cell epitope that was recognized both after induction of arthritis with whole Mycobacterium tuberculosis and after immunization with mycobacterial hsp60 . In rats treated intranasally or subcutaneously with 176-190 and immunized with mycobacterial hsp60, proliferative responses to 176-190 were reduced . Proliferative responses to 211-225 and to whole mycobacterial hsp60 were not affected . AA was inhibited intranasally in the 176-190-treated rats but not in the 211-225-treated rats . Moreover, intranasal 176-190 led to similar arthritis-protective effects in a nonmicrobially induced experimental arthritis (avridine-induced arthritis) . Therefore, tolerance for a disease-triggering, microbial cartilage-mimicking epitope may cause resistance to arthritis irrespective of the actual trigger leading to development of the disease.

Phytochemistry, 1997 Apr, 44(8), 1479 - 82
Enantioselective accumulation of (--)-pinoresinol through O-demethylation of (+/-)-eudesmin by Aspergillus niger; Kasahara H et al.; Microbial transformation of (+/-)-eudesmin by Aspergillus niger was investigated . Enantioselective accumulation of (--)-pinoresinol was shown through O-demethylation of (+/-)-eudesmin . This fungus O- demethylated both enantiomers of eudesmin, but the conversion rates for each enantiomer were clearly different.

Curr Opin Biotechnol, 1997 Apr 1, 8(2), 175 - 80
Developments in metabolic engineering; Cameron DC et al.; The complete sequencing of several microbial genomes has resulted in the increased availability of genes for metabolic engineering . The number of databases and computational tools to deal with this information has also increased . This development has stimulated, and will continue to stimulate, advances in metabolic engineering . Specific recent advances include improvement of pathways for aromatic metabolites, the development of a more complete understanding of the effect of bacterial hemoglobin on cell performance, the development of NMR-based methods for the monitoring of intracellular metabolites and metabolic flux, and the application of metabolic control analysis and metabolic flux analysis to a variety of systems.

Eur J Biochem, 1997 Mar 15, 244(3), 858 - 61
Characterization of hexose oxidase from the red seaweed Chondrus crispus; Groen BW et al.; Hexose oxidase from the red seaweed, Chondrus crispus was purified to homogeneity . The enzyme appeared to be encapsulated in particles obtained after mechanical disintegration of the fronds . Liberation of the enzyme in soluble form required either waiting for the spontaneous development of a suitable microbial flora in the suspension, or treatment with a mixture of proteases (pronase) . As deduced from (SDS/)PAGE, the enzyme has a molecular mass of 87 kDa and probably consists of subunits of 36 kDa and 25 kDa . The low isoelectric point of 2.8 and the presence of 25% (by mass) sugars indicate that the enzyme is a strongly acidic glycoprotein . The absorption spectrum of isolated enzyme minus that of the substrate-reduced enzyme, and the EPR spectrum of the free radical observed in the reduced enzyme revealed the presence of a flavin . This cofactor is probably covalently bound since flavins were not released upon denaturation of the enzyme by heat or acid treatment . Taking free FAD as a reference compound, the enzyme contains 1 mol flavin/mol enzyme . EPR spectroscopy of the purified preparation showed the presence of Cu2+ . However, since the amount was substoichiometric, substrate addition did not affect the signal, and the addition of chelator or Cu2+ did not affect the activity, the presence of this metal ion seems adventitious . It is concluded that the large discrepancies between the presently and the previously reported {Sullivan, J . D . & Ikawa, M . (1973) Biochim . Biophys . Acta 309, 11-22} characteristics of the enzyme probably originate from the characterization of a contaminating protein in the latter case.

J Pharm Pharmacol, 1997 Mar, 49(3), 263 - 9
Optimization of the chiral inversion of 2-phenylpropionic acid by Verticillium lecanii; Thomason MJ et al.; Previous studies have demonstrated that Verticillium lecanii might be used as a microbial model of the inversion of 2-arylpropionic acids in man . This paper describes the optimization of the inversion process in respect of culture medium, pH, cell density and substrate concentration . The study demonstrates that optimum inversion occurs in Sorensen's phosphate buffer at pH 5.5 . The extent and rate of inversion were also shown to be dependent on substrate concentration and cell density . This study will form the basis of the development of a microbial model of the metabolism of 2-arylpropionic acids which might be suitable for the in-vitro screening of new compounds in this class.

Drug Metab Dispos, 1997 Mar, 25(3), 301 - 10
Microbial models of mammalian metabolism . Fungal metabolism of phenolic and nonphenolic p-cymene-related drugs and prodrugs . I . Metabolites of thymoxamine; Moussa C et al.; This study was undertaken to validate the use of microbial biotransformation systems for drug metabolism studies . Thymoxamine 1 was rapidly hydrolyzed to desacetylthymoxamine (DAT) 2 by numerous fungi . Other known animal metabolites, such as N-desmethyl-desacetylthymoxamine 3 and desacetylthymoxamine-O-sulfate 6, were produced from DAT by Mucor rouxii and Mortierella isabellina . DAT-N-oxide 5, a putative animal microsomal metabolite, was also produced by M . isabellina, in addition, a few strains (such as Actinomucor elegans, Mucor hiemalis, and Mucor janssenii) produced a glycosylated metabolite that was identified by high-resolution 1H- and 13C-NMR, MS, and enzymatic hydrolysis as the corresponding {4-(2-dimethylaminoethoxy)-5-isopropyl-2-methyl-phenyl}-1-beta-D- glucopyranoside 7 . A similar glucosylation reaction was observed when thymohydroquinone 10 was incubated with A . elegans . Several strains were able to produce transiently thymohydroquinone from DAT-N-oxide 5, possibly through a beta-elimination mechanism.

Ann Periodontol, 1997 Mar, 2(1), 299 - 313
Clinical trials of endosseous implants: issues in analysis and interpretation; Listgarten MA; The majority of contemporary endosseous dental implant systems are based on designs and materials that, over the last three decades, have proved to be predictably reliable . With proper surgical and prosthetic protocols, rates of implant loss have been held to 15% or less over a 5-year period . This information was obtained largely through longitudinal descriptive studies, primarily aimed at obtaining implant survival rates under ideal clinical conditions, with strict inclusion and exclusion criteria for admitting patients into the studies . It is important to emphasize that under conditions of routine clinical practice, where patient selection may be more relaxed than in clinical trials and clinicians attempt to stretch the limits of current technology, the survival rates may not necessarily match those reported in the literature . Since "surviving" implants may exhibit characteristics likely to lead to eventual loss of the implant, for example severe osseous defects, such implants may not necessarily be considered successful . Successful implants should fulfill a list of other criteria considered essential for long-term survival . Differences in implant design preclude some of these criteria from being uniformly applied to all systems . There is a need to identify criteria for success that can be applied to the majority of implant systems . Implants that fail to meet these criteria should be considered failures . Since failure rates may include "failed" as well as "failing" ("ailing") implants, the two categories should be listed separately . From a practical standpoint, implant failures can be grouped into "early" failures, primarily the result of surgical and/or postoperative complications, and "late" failures that arise during and following the restorative phase . The ability of individual systems to achieve excellent success rates, despite some major differences in their design from other systems, suggests that some requirements, initially considered essential for success, may not be as critical as originally believed . Examples include the need for submerging implants during initial wound healing or the need for stress breaking devices . On the other hand, a basic requirement for implant success, such as primary stability at the time of insertion and following loading of the implant, may be the unifying principle behind the need for adequate bone volume and density, longer or wider implants, and the 3 to 6-month delay recommended before implants are placed in function . With relatively low failure rates, a large number of patients may have to be included in long-term clinical trials before a statistically significant association can be established between failure rates and potential contributing factors . For the same reasons, and to avoid type 2 errors, large populations may be needed to show that two systems have comparable success rates . Proving the superiority of one system over another may require fewer subjects . Given the overall low failure rate and the tendency of failures to cluster in individual subjects, failure rates could be markedly affected by the attrition of a few critical subjects . Additional research is needed to validate methods in current use for the clinical determination of osseointegration, and the diagnosis and treatment of occlusal trauma and microbial infections around implants . Also, more reliable methods are needed for the identification of the primary cause(s) of implant morbidity; i.e., infection or occlusal factors.

Xenobiotica, 1997 Mar, 27(3), 301 - 15
Fungal transformations of antihistamines: metabolism of cyproheptadine hydrochloride by Cunninghamella elegans; Zhang D et al.; 1 . Metabolites formed during incubation of the antihistamine cyproheptadine hydrochloride with the zygomycete fungus Cunninghamella elegans in liquid culture were determined . The metabolites were isolated by hple and identified by mass spectrometric and proton nmr spectroscopic analysis . Two C elegans strains, ATCC 9245 and ATCC 36112, were screened and both produced essentially identical metabolites . 2 . Within 72 h cyproheptadine was extensively biotransformed to at least eight oxidative phase-I metabolites primarily via aromatic hydroxylation metabolic pathways . Cyproheptadine was biotransformed predominantly to 2-hydroxycyproheptadine . Other metabolites identified were 1- and 3-hydroxycyproheptadine, cyproheptadine 10,11-epoxide, N-desmethylcyproheptadine, N-desmethyl-2-hydroxycyproheptadine, cyproheptadine N-oxide, and 2-hydroxycyproheptadine N-oxide . Although a minor fungal metabolite, cyproheptadine 10,11-epoxide represents the first stable epoxide isolated from the microbial biotransformation of drugs . 3 . The enzymatic mechanism for the formation of the major fungal metabolite, 2-hydroxycyproheptadine, was investigated . The oxygen atom was derived from molecular oxygen as determined from 18O-labelling experiments . The formation of 2-hydroxycyproheptadine was inhibited 35, 70 and 97% by cytochrome P450 inhibitors metyrapone, proadifen and 1-aminobenzotriazole respectively . Cytochrome P450 was detected in the microsomal fractions of C . elegans . In addition, 2-hydroxylase activity was found in cell-free extracts of C . elegans . This activity was inhibited by proadifen and CO, and was inducible by naphthalene . These results are consistent with the fungal epoxidation and hydroxylation reactions being catalysed by cytochrome P450 monooxygenases . 4 . The effects of types of media on the biotransformation of cyproheptadine were investigated . It appears that the glucose level significantly affects the biotransformation rates of cyproheptadine; however it did not change the relative ratios between metabolites produced.

Med Hypotheses, 1997 Mar, 48(3), 253 - 9
Superantigens as virulence factors in autoimmunity and immunodeficiency diseases; Soos JM et al.; Virulence factors are microbial products that are known to be harmful to the host and may assist in the pathogenesis of the micro-organism . Superantigens, including those produced by bacteria and viruses, clearly act as virulence factors . The clinical effects of superantigens can be not only acute but also chronic and complex . Recent evidence suggests that superantigens may play a central role in the pathogenesis of autoimmune and immunodeficiency disorders . It is our contention that superantigens, as environmental factors, can change a controllable disease into one that becomes relentless for susceptible individuals . To illustrate the detrimental effects of superantigens on disease outcome, modulation of experimental allergic encephalomyelitis by superantigen, as well as the potential role of superantigens in human immunodeficiency virus pathogenesis will be discussed . The information presented may provide valuable insight into the role of superantigens in autoimmunity and human immunodeficiency virus infection.

Int J Sports Med, 1997 Mar, 18 Suppl 1, S46 - 55
Exercise immunology and neutrophils; Smith JA; Neutrophils play important roles in host defense against infectious agents but, paradoxically, they are also involved in the pathology of various inflammatory conditions . Their microbicidal armory consists of oxidative and nonoxidative processes that are activated simultaneously upon phagocytosis . While destruction of infectious agents occurs intracellularly, release of cytotoxic molecules into the extracellular milieu can damage body tissues . Neutrophils are not a homogeneous cell population . Subpopulations exist in various stages from dormant to primed to fully activated . The activities of neutrophils are modulated by cytokines, hormones and bioactive lipids . As neutrophils represent 60% of the circulating leukocyte pool, they are readily accessible to experimental investigation . The sequence of events that occurs in the neutrophil response to microbial invasion includes adherence, chemotaxis, phagocytosis, the oxidative burst, degranulation and microbial killing . In general, high-intensity exercise suppresses most neutrophil functions both acutely and chronically while the effects of moderate exercise have been conflicting . This review will summarize where the field is now and present some suggestions for future research . Emphasis will be placed on resolving conflicting results that may be due to biological and technical variability, and determination of the regulatory events that may mediate exercise-induced changes in neutrophil function.

Ecotoxicol Environ Saf, 1997 Mar, 36(2), 162 - 8
Ecological effects assessment of industrial sludge for microarthropods and decomposition in a spruce plantation; Krogh PH et al.; Effects of dried, granulated industrial sludge-containing residues of organic pesticides and precursors were assessed for microarthropod fauna and the decomposition of a spruce forest floor . The investigation was highly realistic, using large plots of about 1/2 ha, and the application was done with professional equipment . The ecological effects of the sludge were compared with the ecological effects of an inorganic fertilizer . Decreases in abundance of the microarthropods ranged from 20 to 80% of the control level after 1 year . Isotoma notabilis Schaffer was the only species that exhibited stimulation at twice the control level due to the sludge . The least affected collembolan species was Lepidocyrtus cyaneus Tullberg, a member of the surface-dwelling life forms . Sensitive species were Isotoma anglicana Lubbock and Isotomiella minor Schaffer . In subhabitats with almost no application of sludge due to a heterogeneous horizontal distribution, the microarthropods were still affected to the same degree as those in the zones of maximum application . Laboratory tests with Folsomia candida Willem gave results similar to the effects on field populations concerning the sludge but revealed no adverse effects of the fertilizer . Decomposition was stimulated to the same extent in the field by the two types of fertilizer but in the laboratory the sludge caused the largest stimulation . The effects on the microarthropod fauna are suggested to be the result of a combination of direct toxicity and changes in the microbial community due to fertilizers.

Chest, 1997 Mar, 111(3), 676 - 85
Impact of BAL data on the therapy and outcome of ventilator-associated pneumonia; Luna CM et al.; STUDY OBJECTIVE: To define the impact of BAL data on the selection of antibiotics and the outcomes of patients with ventilator-associated pneumonia (VAP) . DESIGN: Prospective observation and bronchoscopy with BAL, performed within 24 h of establishing a clinical diagnosis of a new episode of hospital-acquired VAP or progression of a prior episode of nosocomial pneumonia (NP) . SETTING: A 15-bed medical and surgical ICU . PATIENTS: One hundred thirty-two patients hospitalized for more than 72 h, who were mechanically ventilated and had a new or progressive lung infiltrate plus at least two of the following three clinical criteria for VAP: abnormal temperature (> 38 degrees C or < 35 degrees C), abnormal leukocyte count (> 10,000/mm3 or < 3,000/mm3), purulent bronchial secretions . INTERVENTIONS: Bronchoscopy with BAL within 24 h of establishing a clinical diagnosis of VAP or progression of an infiltrate due to prior VAP or NP . All patients received antibiotics, 107 prior to bronchoscopy and 25 immediately after bronchoscopy . RESULTS: Sixty-five of the 132 patients were BAL positive (BAL{+}), satisfying a microbiologic definition of VAP (> 10(4) cfu/mL), while 67 were BAL negative (BAL{-}) . The BAL(+) patients had no differences in mortality, prior antibiotic use, and demographic features when compared with the BAL(-) patients . More of the BAL(+) patients (38/65) satisfied all three clinical criteria of VAP than did BAL(-) patients (24/67) (p < 0.05) . A total of 50 BAL(+) patients received antibiotic therapy prior to bronchoscopy, and when this prior therapy was adequate (n = 16), as defined by the results of BAL, then mortality was 38%, while if prior therapy was inadequate (n = 34), mortality was 91% (p < 0.001), and if no therapy was given (n = 15), mortality was 60% . When therapy changes were made after bronchoscopy, more patients (n = 42) received adequate therapy, but mortality in this group was comparable to mortality among those who continued to receive inadequate therapy (n = 23) . A total of 46 of the 65 BAL(+) patients died, with 23 of these deaths occurring during the 48 h after the bronchoscopy, before BAL results were known . When BAL data became available, 37 of the 42 surviving patients received adequate therapy, but their mortality was comparable to the patients who continued to receive inadequate therapy . CONCLUSIONS: Patients with a strong clinical suspicion of VAP have a high mortality rate, regardless of whether BAL cultures confirm the clinical diagnosis of VAP . When adequate antibiotic therapy is initiated very early (ie, before performing bronchoscopy), mortality rate is reduced if this empiric therapy is adequate, compared to when this therapy is inadequate or no therapy is given . If adequate therapy is delayed until bronchoscopy is performed or until BAL results are known, mortality is higher than if it had been given at the time of first establishing a clinical diagnosis of VAP . When patients were changed from inadequate antibiotic therapy to adequate therapy, based on the results of BAL, mortality was comparable to those who continued to receive inadequate therapy . Thus, even if bronchoscopy can accurately define the microbial etiology of VAP, this information becomes available too late to influence survival.

J Dent, 1997 Mar, 25(2), 79 - 89
Children, adolescents and periodontal diseases; Dibart S; OBJECTIVES: This manuscript attempts to critically review current literature regarding the natural history, aetiology and pathogenesis of the common periodontal diseases to affect children and adolescents . The logic behind the emergence of a new classification in the early 1990s is explained and potential problems with the interpretation of such systems outlined . DATA SOURCES: The manuscript focuses upon recent developments, reported in the international periodontal literature, aimed at unraveling the molecular basis for this group of diseases . The concept of one disease type progressing with time to another disease within the same individual is discussed, and early data presented that indicate the possibility of microbial transmission from deciduous to permanent dentition's within a subject . CONCLUSIONS: It is concluded that differing classification systems for adolescent and childhood periodontal diseases may lead to confusion within the dental profession, unless the clinical and molecular basis for such diseases is fully understood . Further advances in basic research using molecular biology tools should assist in our understanding of the aetiopathology at a molecular level and hopefully lead to the development of new treatment strategies.

J Math Biol, 1997 Mar, 35(4), 453 - 79
Population dynamics and competition in chemostat models with adaptive nutrient uptake; Tang B et al.; The standard Monod model for microbial population dynamics in the chemostat is modified to take into consideration that cells can adapt to the change of nutrient concentration in the chemostat by switching between fast and slow nutrient uptake and growing modes with asymmetric thresholds for transition from one mode to another . This is a generalization of a modified Monod model which considers adaptation by transition between active growing and quiescent cells . Global analysis of the model equations is obtained using the theory of asymptotically autonomous systems . Transient oscillatory population density and hysteresis growth pattern observed experimentally, which do not occur for the standard Monod model, can be explained by such adaptive mechanism of the cells . Competition between two species that can switch between fast and slow nutrient uptake and growing modes is also considered . It is shown that generically there is no coexistence steady state, and only one steady state, corresponding to the survival of at most one species in the chemostat, is a local attractor . Numerical simulations reproduce the qualitative feature of some experimental data which show that the population density of the winning species approaches a positive steady state via transient oscillations while that of the losing species approaches the zero steady state monotonically.

J Med Entomol, 1997 Mar, 34(2), 87 - 94
Black fly (Diptera:Simuliidae) salivary secretions: importance in vector competence and disease; Cupp EW et al.; When blood-feeding, black flies introduce secretions into the feeding lesion that act in a coordinated manner on the 3 arms of the vertebrate hemostatic system (platelet aggregation, coagulation, and vasoconstriction) . Apyrase activity inhibits platelet aggregation and is ubiquitous in the saliva of black flies, although activity per gland varies by species and has a positive association with anthropophagy . Anticoagulants target components in the final common pathway of the coagulation cascade, including factors V, Xa, and II (thrombin) . The antithrombin salivary protein may exert a redundant effect by inhibiting the role of thrombin in platelet aggregation . Antithrombin presence and activity also varies among black fly species, and exhibits a positive correlation with zoophagy . Vasodilation of capillaries to increase blood supply to the feeding wound appears to be an important requirement for Simulium spp., because substantial erythema-inducing activity, has been demonstrated in salivary glands of all New World species examined . Salivary glands of Simulium ochraceum (Walker), a highly anthropophilic vector of Onchocerca volvulus (Leuckhart), contain greater vasodilator activity than several other species, including S . metallicum Bellardi, a secondary zoophagic vector of human onchocerciasis . Simulium vittatum Zetterstedt saliva affects immune cell responses and cytokine production . The ability of the saliva to modulate components of the host immune system provides an opportunity for enhancing transmission of pathogens during bloodfeeding . Thus, the likely possibility that effective pathogen transmission relies on vector saliva may complement present efforts aimed at target epitopes of O . volvulus or identify additional molecules to be investigated as part of a "river blindness" vaccine cocktail . Components in saliva also may enhance the transmission of other microbial agents either by a cofeeding process similar to that observed in ixodid ticks or through rupture of the labrum during escape of Onchocerca infective stage larvae . In a few instances, saliva of some Simulium spp . also has been associated with extensive tissue and organ pathology, including hemorrhagic shock and death . Pathologic signs associated with this syndrome indicate an enhanced antihemostatic activity in saliva.

Inflamm Res, 1997 Mar, 46(3), 93 - 7
Pulmonary cell infiltration after chronic exposure to (1-->3)-beta-D-glucan and cigarette smoke; Sjostrand M et al.; OBJECTIVE AND DESIGN: To evaluate the effect of a microbial cell wall component--(1-->3)-beta-D-glucan--on the inflammatory effect induced by cigarette smoke in a subchronic exposure situation . MATERIAL: Groups of guinea-pigs were exposed 5 days/week to cigarette smoke, an aerosol of (1-->3)-beta-D-glucan, or to both . METHODS: The numbers of different inflammatory cells were studied in histological sections, enzyme digested lung tissue and in lung lavage . Cell enzyme production was measured . RESULTS: Exposure to (1-->3)-beta-D-glucan or cigarette smoke caused only minor alterations in inflammatory cells . Given together they caused an increase in cellularity in the tissue with significantly increased numbers of macrophages, lymphocytes, neutrophils and eosinophils . There was also an increase in subepithelial eosinophils . Lung lavage cell enzyme production was slightly lower in the combined exposure group . CONCLUSION: The results demonstrate that (1-->3)-beta-D-glucan synergistically increases the inflammation induced by cigarette smoke . The mechanism may be a downregulation of the macrophage control of inflammatory cell migration into the lung tissue.

J Clin Pharmacol, 1997 Mar, 37(3), 175 - 8
Relationship between the prescriber's instructions and compliance with antibiotherapy in outpatients treated for an acute infectious disease; Favre O et al.; Antibiotics are frequently prescribed in everyday practice for the management of acute microbial infections . The present study was designed to assess the relationship between the prescriber's instructions and the patient's adherence to a prescribed schedule of twice-daily doses of antibiotic for at least 5 days to treat an infectious disease . The trial was conducted by ten practicing physicians on ambulatory patients . Compliance with the antibiotic regimen was evaluated using a microelectronic device, the Medication Event Monitoring System (MEMS) . Seventy patients were prescribed an antibiotic in twice-daily doses for 5 to 14 days (mean = 8) . Data were available for analysis from 68 of them, aged 18 to 84 years (mean = 44) . The "taking compliance" for the whole story group, which corresponded to the ratio of the number of times the bottle was opened and the total number of doses prescribed during the monitoring period, was nearly perfect at 99.6% . However, only 32.6% of the medications was taken within 1 hour before or after the 12-hour interval expected to be optimal for a twice-daily regimen . It therefore seems highly desirable that physicians give more detailed recommendations to their patients regarding the drug regimens they prescribe.

Lipids, 1997 Mar, 32(3), 263 - 71
Differentiation of human promyelocytic leukemia cell line HL60 by microbial extracellular glycolipids; Isoda H et al.; Microbial extracellular glycolipids, succinoyl trehalose lipid (STL), and mannosylerythritol lipid (MEL) inhibited the growth of a human promyelocytic leukemia cell line, HL60, and induced their morphological changes . The results of specific and nonspecific leukocyte esterase activities showed that STL induced monocytotic differentiation while MEL induced granulocytic differentiation . STL and MEL markedly increased common differentiation-associated characteristics in monocytes and granulocytes, such as nitroblue tetrazolium (NBT) reducing ability, expression of Fc receptors, and phagocytic activities in HL60 cells, respectively . Neither sugar moieties nor fatty acids in the free form, the individual components of STL and MEL, were effective at inducing the differentiation of HL60 cells . The induction of differentiation was not due to surface activities of STL and MEL on the basis of the complete ineffectiveness of the analogues tested . The composition of cell surface glycosphingolipids (GSL) changed such that the GM3/LacCer ratio increased in STL-treated cells, whereas it decreased in MEL-treated cells . HL60 cells treated with STL and MEL exhibited a significant decrease in the activity of the intracellular phospholipid- and Ca(2+)-dependent protein kinase (protein kinase C) . Furthermore, the serine/threonine phosphorylations in intact HL60 cells were clearly inhibited by the presence of GM3 and MEL, but not by LacCer and STL . These results suggest that the differentiation-inducing activity of STL and MEL is not due to a simple detergent-like effect but due to a specific action on the plasma membrane . The inhibitory effect of STL on protein kinase activity was through increasing GM3, but MEL had a direct inhibitory effect.

Cornea, 1997 Mar, 16(2), 125 - 31
Contact lens-related microbial keratitis: Part I: Epidemiology; Liesegang TJ; PURPOSE: To put into perspective the individual risk and the societal burden of contact lens microbial keratitis . METHODS: I reviewed the available epidemiologic data on contact lens microbial keratitis with emphasis on distinguishing microbial from nonmicrobial keratitis, determining the incidence of the disease, the relative risk with different styles of contact lenses, and the risk factors . RESULTS: Contact lens wear can be classified in multiple different ways (indications for wear, contact lens material, wearing schedule, and replacement schedule) . Adverse effects of contact lens wear on the cornea have been documented by several studies . Distinction between aseptic and septic focal infiltrates is discussed . The incidence rates for bacterial microbial keratitis range from approximately two/10,000 per year for rigid contact lens, 2.2-4.1/10,000 per year for daily-wear soft contact lens, to 13.3-20.9/10,000 per year for extended-wear soft contact lenses . The risk with therapeutic contact lenses is much higher: approximately 52/10,000 per year . Comparative studies suggest that the relative risk of microbial keratitis is approximately 1 for rigid gas-permeable lenses (RGPs; the referent), 0.5-2.74 for polymethylmethacrylate (PMMA), 1.0-4.2 for daily-wear soft contact lenses, 2.7-36.8 for extended-wear soft contact lenses, and 13.0-13.3 for disposable soft contact lens wear . The most significant risk factors include overnight wear, smoking, male sex, and socioeconomic status . CONCLUSIONS: There is a significant health concern for the 26 million wearers of contact lenses with some potentially modifiable risk factors . Identification of the risk factors and further studies of the pathogenesis allow contact lens manufacturers to direct research efforts and practitioners to provide better information and informed consent to patients.

FASEB J, 1997 Mar, 11(4), 248 - 55
Sialic acids as ligands in recognition phenomena; Varki A; The sialic acids are acidic monosaccharides typically found at the outermost ends of the sugar chains of animal glycoconjugates . They potentially can inhibit intermolecular and intercellular interactions by virtue of their negative charge . However, they can also act as critical components of ligands recognized by a variety of proteins of animal, plant, and microbial origin (sialic acid binding lectins) . Recognition can be affected by specific structural variations and modifications of sialic acids, their linkage to the underlying sugar chain, the structure of these chains, and the nature of the glycoconjugate to which they are attached . Presented here is a summary of the various proteins that can recognize and bind to this family of monosaccharides, comparing and contrasting the structural requirements and mechanisms involved in binding . Particular attention is focused on the recently evolving information about sialic acid recognition by certain C-type lectins (the selectins), I-type lectins (e.g., CD22 and sialoadhesin), and a complement regulatory protein (the H protein) . The last two instances are examples of the importance of the side chain of sialic acids and the effects of natural substitutions (e.g., 9-O-acetylation) of this part of the molecule.

Appl Environ Microbiol, 1997 Mar, 63(3), 1143 - 7
Molecular beacons: trial of a fluorescence-based solution hybridization technique for ecological studies with ruminal bacteria; Schofield P et al.; Molecular beacons are fluorescent probes developed for solution rather than membrane hybridization . We have investigated the utility of these probes to study rumen microbial ecology . Two cellulolytic species, Ruminococcus albus and Fibrobacter succinogenes, were tested . Membrane and solution hybridizations gave similar results in competition experiments with cocultures of R . albus 8 and F . succinogenes S85.

Appl Environ Microbiol, 1997 Mar, 63(3), 888 - 95
Plasmids isolated from marine sediment microbial communities contain replication and incompatibility regions unrelated to those of known plasmid groups; Sobecky PA et al.; Two hundred ninety-seven bacteria carrying plasmids that range in size from 5 to 250 kb were identified from more than 1,000 aerobic heterotrophic bacteria isolated from coastal California marine sediments . While some isolates contained numerous (three to five) small (5- to 10-kb) plasmids, the majority of the natural isolates typically contained one large (40- to 100-kb) plasmid . By the method of plasmid isolation used in this study, the frequency of plasmid incidence ranged from 24 to 28% depending on the samples examined . Diversity of the plasmids occurring in the marine sediment bacterial populations was examined at the molecular level by hybridization with 14 different DNA probes specific for the incompatibility and replication (inc/rep) regions of a number of well-characterized plasmid incompatibility groups (repB/O, FIA, FII, FIB, HI1, HI2, I1, L/M, X, N, P, Q, W, and U) . Interestingly, we found no DNA homology between the plasmids isolated from the culturable bacterial population of marine sediments and the replicon probes specific for numerous incompatibility groups developed by Couturier et al . (M . F . Couturier, F . Bex, P . L . Bergquist, and W . K . Maas, Microbiol . Rev . 52:375-395, 1988) . Our findings suggest that plasmids in marine sediment microbial communities contain novel, as-yet-uncharacterized, incompatibility and replication regions and that the present replicon typing system, based primarily on plasmids derived from clinical isolates, may not be representative of the plasmid diversity occurring in some marine environments . Since the vast majority of marine bacteria are not culturable under laboratory conditions, we also screened microbial community DNA for the presence of broad- and narrow-host-range plasmid replication sequences . Although the replication origin of the conjugally promiscuous broad-host-range plasmid RK2 (incP) was not detectable in any of the plasmid-containing culturable marine isolates, DNA extracted from the microbial community and amplified by PCR yielded a positive signal for RK2 oriV replication sequences . The strength of the signal suggests the presence of a low level of the incP replicon within the marine microbial community . In contrast, replication sequences specific for the narrow-host-range plasmid F were not detectable in DNA extracted from marine sediment microbial communities . With the possible exception of mercuric chloride, phenotypic analysis of the 297 plasmid-bearing isolates did not demonstrate a correlation between plasmid content and antibiotic or heavy metal resistance traits.

Cancer Res, 1997 Mar 1, 57(5), 812 - 4
Intestinal neoplasia in the ApcMin mouse: independence from the microbial and natural killer (beige locus) status; Dove WF et al.; We have tested the hypothesis that enteric bacteria are necessary for formation of intestinal adenomas in C57BL/6-ApcMin/+ mouse . Germ-free mice developed 2-fold fewer adenomas than conventional controls in the medial small intestine (7.3 versus 14.9; P < 0.003), but there were no significant differences in the rest of the intestinal tract . We conclude that microbial status does not strongly alter the adenoma phenotype in this mouse model of familial adenomatous polyposis . In parallel, we have found that C57BL/6-ApcMin/+ mice mutated at the beige locus, which controls natural killer activity, are also unaltered in adenoma multiplicity.

Environ Manage, 1997 Mar, 21(2), 233 - 8
Effects of Recreational Impacts on Soil Microbial Communities
ZABINSKI CA, GANNON JE.
/ The functional diversity of soil microbial communities in heavilyimpacted subalpine campsites and adjacent undisturbed areas was comparedusing the Biolog method of carbon utilization profiles . Principal componentsanalysis of patterns and level of microbial activity indicate that microbialcommunities differentiate in response to disturbance in the top 6 cm of soil,while below 6 cm there were no recognizable differences between disturbed andundisturbed soil communities . Analysis of the factors that differentiate theupper microbial communities between disturbed and undisturbed sites revealedthat the percent of total carbon sources utilized was significantly less inthe disturbed (54%) than in undisturbed areas (95%) . Carbonsubstrates important in the discrimination between soil communities includeplant, invertebrate, and microbial derivatives that could not be metabolizedby microbial communities from disturbed sites . Comparisons of totalculturable actinomycetes, bacteria, and fungi reveal no difference in overallnumber of colony forming units (CFU) on disturbed and undisturbed sites, buta marked decrease in actinomycetes on disturbed sites . Biolog andspread-plate data combined indicate a shift in the structure and function ofthe microbial community in campsite soils, which may be a useful indicator ofsoil community disturbance.KEY WORDS: Microbial functional diversity; Anthropogenic disturbance;Recreational impacts; Carbon source profile; Subalpine

Presse Med, 1997 Feb 22, 26(5), 204 - 6
{The concept of reactive arthritis}; Dougados M; More than fifty years after the clinical syndrome was described by Reiter, Fiessinger and Leroy, the diagnostic criteria of what has now been termed reactive arthritis are still under debate . Reactive arthritis can be defined as an aseptic inflammatory joint disease occurring either in a patient with a bacterial infection located in a distant organ or with a particular genetic predisposition . The lack of specific criteria has led to a certain degree of liberty in interpreting the three basic elements of reactive arthritis: clinical presentation, "distant" infection, genetic predisposition . It is generally accepted that limiting the diagnosis of reactive arthritis only to patients with the classic oculo-uretro-synovial manifestations is unsatisfactory . The question remains open as to whether only patients presenting both inflammatory joint disease and spondylarthropathy have reactive arthritis or whether any undetermined etiology of arthritis is sufficient if the patient also has a "distant" infection and a specific genetic predisposition (HLA B27) . Two new elements further complicate the situation . The first is the recent demonstration that the synovial fluid in patients with reactive arthritis might contain microbial antigens . The second is that longterm antibiotics (more than 3 months) could have a beneficial effect . Asking when the diagnosis should be entertained is thus not a moot question . Although we still have no clear answer, it is reasonable to state that the diagnosis of reactive arthritis should be retained only in patients with both inflammatory joint disease and criteria compatible with spondylarthropathy . Clinical research is required to determine whether the germ is actually present or not within the joint and to assess the effect of long-term antibiotherapy.

Eur J Pharmacol, 1997 Feb 19, 321(1), 87 - 96
The protective role of thiols against nitric oxide-mediated cytotoxicity in murine macrophage J774 cells; Zamora R et al.; Nitric oxide (NO) plays an important role in the cytotoxic activity of macrophages towards tumour cells and microbial pathogens . We investigated whether alteration of intracellular thiol levels modulates the cytotoxic effects of different NO donors and lipopolysaccharide-induced NO in the murine macrophage cell lin J774A.1 . The NO-releasing compound S-nitroso-N-acetylpenicillamine caused a significant concentration-dependent loss of viability of the macrophages only under glucose-limiting conditions . The cytotoxic effect of S-nitroso-N-acetylpenicillamine was prevented by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) . Depletion of total glutathione before exposure to S-nitroso-N-acetylpenicillamine further decrease cell viability while pretreatment with N-acetylcysteine was protective . Comparing equimolar concentrations of various NO donors including S-nitrosoglutathione, S-nitrosocysteine and 3-morpholino-sydnonimine hydrochloride, cytotoxicity appeared to be related to the relative stability of the test compound . Both the order of stability and the order of potency for cell killing was S-nitrosoglutathione > S-nitroso-N-acetylpenicillamine > S-nitrosocysteine = 3-morpholino-sydnonimine hydrochloride . Stimulation of the macrophages with lipopolysaccharide and interferon-gamma resulted in dose-dependent cell injury and NO production . Glutathione depletion prior to stimulation considerably decreased macrophage viability as well as the NO production . In contrast to the protective effect on S-nitroso-N-acetylpenicillamine-mediated injury, pretreatment with N-acetylcysteine did not influence the lipopolysaccharide-mediated cytotoxicity . These results demonstrate that (a) reduction in the availability of glucose and intracellular glutathione renders the cells more vulnerable to the cytotoxic effects of NO donors, (b) in this model of cytotoxicity, long-lived NO donors were more cytotoxic than short-lived NO donors, (c) the differential effects of N-acetylcysteine on S-nitroso-N-acetylpenicillamine-induced and bacterial lipopolysaccharide-mediated cytotoxicity support the existence of other toxic species different from NO or NO-related compounds with a potent cytotoxic activity in immunostimulated macrophages, and (d) other non-protein thiols like N-acetylcysteine may substitute for glutathione as a major component of the cellular antioxidant defense system.

Proc Natl Acad Sci U S A, 1997 Feb 18, 94(4), 1321 - 6
A genetic system to identify DNA polymerase beta mutator mutants; Washington SL et al.; DNA polymerase beta (pol beta) is a 39-kDa protein that functions in DNA repair processes in mammalian cells . As a first step toward understanding mechanisms of polymerase fidelity, we developed a genetic method to identify mammalian pol beta mutator mutants . This screen takes advantage of a microbial genetics assay and the ability of rat pol beta to substitute for Escherichia coli DNA polymerase I in DNA replication in vivo . Using this screen, we identified 13 candidate pol beta mutator mutants . Three of the candidate mutator mutants were further characterized in vivo and shown to confer an increased spontaneous mutation frequency over that of wild-type pol beta to our bacterial strain . Purification and subsequent analysis of one of our putative mutator proteins, the pol beta-14 protein, showed that it possesses intrinsic mutator activity in four different assays that measure the fidelity of DNA synthesis . Therefore, residue 265, which is altered in pol beta-14 and another of our mutant proteins, pol beta-166, is probably critical for accurate DNA synthesis by pol beta . Thus, our genetic method of screening for pol beta mutator mutants is useful in identifying active mammalian DNA polymerase mutants that encode enzymes that catalyze DNA synthesis with altered fidelity compared with the wild-type pol beta enzyme.

Virology, 1997 Feb 17, 228(2), 123 - 31
Desialylation of peripheral blood mononuclear cells promotes growth of HIV-1; Stamatos NM et al.; Activation of peripheral blood CD4+ helper T lymphocytes establishes a permissive state for growth of HIV-1 . Activated T lymphocytes expressed increased sialidase (neuraminidase) activity and were hyposialylated . Treatment of freshly isolated peripheral blood mononuclear cells (PBMCs) with microbial neuraminidase (NANase) or phytohemagglutinin (PHA) prior to infection at low multiplicity with T cell line-adapted HIV-1IIIB resulted in production of large amounts of p24 antigen and reverse transcriptase . In contrast, neither viral component was detected in the medium of mock-treated cells infected at a similar multiplicity through 21 days in culture . The titer of a stock solution of HIV-1IIIB was 1.4 +/- 0.18 log10 greater in NANase-treated PBMCs than in mock-treated cells; the titer was similarly raised 1.5 to 1.76 +/- 0.18 log10 in PHA-treated cells . Growth of the primary isolate HIV-1(91/US/056) was also enhanced in NANase-treated PBMCs; the titer of a stock solution of HIV-1(91/US/056 was 1.0 +/- 0.16 log10 greater in NANase-treated PBMCs than in mock-treated cells 7 days after infection . No enhancement of viral growth in PBMCs was detected when NANase was heat-inactivated or specifically inhibited with 2,3-dehydro-2-desoxy-N-acetyl-neuraminic acid prior to use . Treatment of PBMCs with NANase did not alter the distribution of lymphocyte subsets nor change the density of CD4 antigen per cell after 7 days in culture . Whereas PHA treatment of PBMCs was mitogenic, pretreatment with NANase was not; the amount of {3H}thymidine incorporated into DNA and culture growth characteristics were similar for NANase- and mock-treated cells . Thus, desialylation of PBMCs promoted a permissive state for growth of HIV-1 without affecting the rate of DNA synthesis or relative number of target CD4+ cells.

Anal Biochem, 1997 Feb 15, 245(2), 226 - 30
An automated high throughput filtration assay: application to polymerase inhibitor identification; Wu P et al.; A high throughput filtration assay was developed and automated for screening compounds and natural product extracts using 96-well filterplates . The selection of a hydrophobic membrane and appropriate capture conditions enabled us to perform the enzymatic reaction, capture of products, vacuum filtration, and detection in a single filtration microplate, without any transfer step . The hydrophobic membrane has the advantage of preventing any loss of aqueous solution during the enzymatic reaction . The results are comparable with those obtained in a solid plate format followed by transferring the reaction mixture to a traditional hydrophilic filterplate . This assay is being used to screen for microbial RNA polymerase inhibitors as potential new drugs for treatment of emerging antibiotic-resistant bacterial and fungal infections . The filtration setup can be applied to a variety of assay systems.

Schweiz Med Wochenschr, 1997 Feb 8, 127(6), 219 - 30
{Bronchiectasis--current aspects of an old disease}; Frey HR et al.; Bronchiectasis is pathologically defined as an abnormal and permanent dilatation of one or several bronchi . There are localized and generalized types of bronchiectasis . A vicious circle hypothesis, including an initial insult to the lower airways, impaired mucociliary clearance, microbial colonization/infection, bronchial obstruction and a local inflammatory response, has been proposed to explain the damage to the bronchial tree and the adjacent lung parenchyma . The clinical picture is variable and affected individuals might be asymptomatic or suffer from severe respiratory failure . Daily sputum production is the most common, though unspecific symptom of bronchiectasis . Other common symptoms are hemoptysis and recurrent episodes of sputum purulence, fever and pleurisy . Occasionally, major, life-threatening hemoptysis from a ruptured bronchial artery occurs . Infectious complications, e.g . lung abscess, empyema, brain abscess, and secondary amyloidosis are rarely seen today . The chest radiograph reveals changes suggestive of bronchiectasis in the majority of patients with clinically important disease . High resolution computed tomography of the lung has almost completely replaced bronchography for diagnosis, the latter rarely being of value if surgery is contemplated . No etiology is identified in about one- to two-thirds of the patients, although there are many diseases eventually associated with bronchiectasis . Prevention and therapy of underlying diseases are most important . Traditionally, the therapy of symptomatic bronchiectasis is based on antibiotics, antibronchoobstructive medication, and chest physical therapy . Surgical resection is the treatment of choice for localized symptomatic disease . Bilateral lung transplantation should be considered in younger patients with severe, generalized bronchiectasis and respiratory failure . Prospective, randomized, largescale trials supporting any of the different treatment strategies are not available, but antibiotics and surgery probably have improved the long-term outcome of many patients with bronchiectasis . In this review, some recent findings regarding the classification, pathogenesis, pathology, etiology, diagnosis, treatment, and prognosis of bronchiectasis are discussed.

Pathol Biol (Paris), 1997 Feb, 45(2), 110 - 4
{Nitric oxide and macrophages}; Drapier JC; Nitric oxide (NO) is a gaseous radical enzymatically produced from L-arginine by virtually every cell . This versatile molecule is involved in a variety of biological functions including defense against pathogens . Micro-organisms whose development is inhibited by NO include fungi, bacteria, protozoa, helminths and viruses . In murine macrophages, a high output NO synthase (NOS II) is regulated transcriptionally by cytokines and microbial products . In the past few years, investigators have identified many other cell types expressing NOS II . However, in human monocytes/macrophages, the existence of the L-arginine-NO pathway has long been questioned . Recent findings and new developments in this respect are commented in this short review.

Infect Control Hosp Epidemiol, 1997 Feb, 18(2), 97 - 103
Handwashing and glove use in a long-term-care facility; Thompson BL et al.; OBJECTIVES: To determine glove use and handwashing practices, the factors associated with infection control practices, and the frequency of potential microbial transmission in a long-term-care facility (LTCF) . DESIGN: Observational study of 230 staff-resident interactions in an LTCF . We recorded resident characteristics, type of activity, staff credentials, and movements of the staff member's hands, then used the LTCF's guidelines to judge appropriateness of glove use and handwashing . SETTING: 255-bed, university-based LTCF in Baltimore, Maryland . PARTICIPANTS: A systematic sample of staff-resident interactions . RESULTS: Gloves were worn in 139 (82%) of 170 interactions when indicated, but changed appropriately in only 1 (16%) of 132 . Hands were washed when needed before an interaction in 27%, during an interaction in 0%, and after an interaction in 63% . Gloves were less likely to be used when caring for residents with gastrostomy tubes compared with other residents (relative risk, 0.85; 95% confidence interval, 0.73-0.98) . Guidelines were followed more frequently during wound care than during other activities . Microbial transmission potentially could have occurred in 158 (82%) of 193 evaluable interactions . CONCLUSIONS: We documented marked deficiencies in glove and handwashing, demonstrated the possible impact of these deficiencies, and identified factors associated with inadequate handwashing and glove use . This information can be used in future educational and research efforts to improve infection control practices.

Protein Expr Purif, 1997 Feb, 9(1), 49 - 52
High-performance liquid chromatographic separation of Porphyromonas gingivalis fimbriae; Sojar HT et al.; Fimbriae are responsible for the adherence of many bacterial species to the surfaces they eventually colonize . Porphyromonas gingivalis is an important pathogenic agent involved in periodontal disease . Fimbriae of P . gingivalis have been thought to mediate binding of the bacterium to oral surfaces . In order to study the role of fimbriae in microbial adhesion, it is important to purify fimbriae to homogeneity . A simple and rapid reverse-phase high-performance liquid chromatography (HPLC) method is developed to purify P . gingivalis fimbriae . The crude fimbriae were precipitated from sonic extract of P . gingivalis cells with the 40% ammonium sulfate precipitation . The dialyzed crude fimbriae preparation was subjected to reverse-phase HPLC separation . The purity and size of purified fimbrial proteins were confirmed by SDS-polyacrylamide gel electrophoresis(SDS-PAGE) followed by Western immunoblot using polyclonal antibodies against fimbriae . The purified major fimbrial protein from strain 33277 of P . gingivalis had apparent molecular mass of 41 kDa . The method is useful for analytical as well as preparative purification with 25% yields from the ammonium sulfate-precipitated crude fimbriae preparation, and represents increased speed and efficiency over earlier published methods.

Intensive Crit Care Nurs, 1997 Feb, 13(1), 26 - 9
Do dressings with increased permeability reduce the incidence of central venous catheter related sepsis?
Reynolds MG, Tebbs SE, Elliott TS.
The incidence of catheter-related sepsis associated-with the use of Tegaderm or Opsite IV3000 dressings on 100 critically ill patients with liver disease was studied . All the patients had central venous catheters in situ and they were randomly assigned to one of the two dressings . In this study the sites of insertion were assessed at each dressing change, together with any fluid under the dressing . No statistically significant difference between the two dressings was found in accumulation of fluid, skin microbial colonization, local infection or systemic infection of patients in our sample . There was no apparent advantage to using the more permeable Opsite IV3000 dressing.

Aust N Z J Obstet Gynaecol, 1997 Feb, 37(1), 88 - 91
Candida glabrata chorioamnionitis following in vitro fertilization and embryo transfer; Sfameni SF et al.; Candida glabrata is a yeast which is considered to be a commensal of the vagina with limited pathogenicity in the immunocompetent host . We report 2 cases of severe chorioamnionitis occurring in pregnancies achieved by in vitro fertilization techniques which resulted in preterm delivery and pregnancy loss . Candida glabrata as the causative agent was probably introduced into the uterus by the cannula at the time of embryo transfer . It is recommended that appropriate investigation of the microbial flora of the cervix be undertaken and treatment instituted prior to embryo transfer in order to prevent this complication.

Biosci Biotechnol Biochem, 1997 Feb, 61(2), 298 - 303
Cloning and expression of an intracellular alkaline protease gene from alkalophilic Thermoactinomyces sp . HS682; Tsuchiya K et al.; An intracellular alkaline serine protease gene of alkalophilic Thermoactinomyces sp . HS682 was cloned and expressed in Escherichia coli . Sequence analysis showed a putative promoter region, a putative transcriptional termination signal, and an open reading frame of 963 bases, coding for a polypeptide of 321 amino acids . The protease expressed in E . coli was purified by DEAE-Toyopearl 650M and Sephadex G-75 chromatography . The N-terminal sequence (30 amino acids) of the purified protein was coincident with Asp16-Val45 of the deduced amino acid sequence of the ORF . Fifteen amino acids in the N-terminal region were removed during the purification procedures . The deduced amino acid sequence showed high similarity with microbial intracellular serine proteases . The molecular mass of this enzyme was estimated to be 38 kDa by SDS-PAGE . The enzyme was stable at pH 6.0-12.0 and below 60 degrees C in the presence of Ca2+ . The temperature and pH optima of the enzyme were 65 degrees C and pH 11.0, respectively . The enzyme was inhibited by DFP and PMSF, but not by MIA and EDTA.

Xenobiotica, 1997 Feb, 27(2), 147 - 57
Novel metabolites of warfarin produced by Beauveria bassiana and Streptomyces rimosus: a novel application of hplc-nmr; Cannell RJ et al.; 1 . Biotransformation of warfarin by the fungus Beauveria bassiana (ATCC 7159) yielded the first reported phase II warfarin metabolite, 3'4'-dihydroxywarfarin-3'-{4-methoxyglucoside}, another previously unreported metabolite, 3',4'-dihydroxywarfarin and also 4'-hydroxywarfarin . 2 . Biotransformation of warfarin by Streptomyces rimosus (NRRL 2234) yielded the previously unreported metabolites, 12-hydroxywarfarin, 4'-hydroxy-11-methoxywarfarin, and also 7-hydroxywarfarin and 4'-hydroxywarfarin, which have not been previously reported as biotransformation products from this organism . 3 . Hplc-nmr has been used to identify biotransformation products of warfarin by S . rimosus directly from the microbial broth without prior isolation and purification.

Am J Infect Control, 1997 Feb, 25(1), 24 - 7
The effect of rings on microbial load of health care workers' hands; Salisbury DM et al.; BACKGROUND: The hands of health care workers (HCWs) serve as a major route for transmission of nosocomial infection . Although handwashing is known to reduce cross-transmission of infection, the influence of rings on the efficacy of handwashing and the carriage of bacteria on the hands has not been well established . METHODS: In this study, 50 HCWs with rings were paired by unit with 50 HCWs without rings . Cultures were obtained by use of a timed-friction rinse before and after a timed handwashing . Standard laboratory procedures were followed for identification of the bacteria . RESULT: When colony counts before handwashing are taken into consideration, a significant difference is seen after handwashing between the two groups (R2 = 0.56) . The regression model showed that the slope was significantly steeper (p < 0.0014) for the group with rings . This effect is more apparent when the colony count on hands is greater than 1000 colony forming units before handwashing . CONCLUSIONS: A standardized, timed handwashing procedure was effective in decreasing the bioload of HCWs' hands . The effect of rings on the bioload was significant in this study.

Poult Sci, 1997 Feb, 76(2), 355 - 60
Microbial phytase improves amino acid utilization in young chicks fed diets based on soybean meal but not diets based on peanut meal; Biehl RR et al.; Studies were conducted to evaluate the ability of supplemental microbial phytase to improve performance of young chicks fed phytate-containing, amino acid-deficient diets . Diets based on corn and peanut meal or soybean meal (SBM) and dextrose were fed to young chicks housed in battery cages for 10- and 13-d experimental periods . Assays were designed to evaluate phytase supplementation of both amino acid-deficient and amino acid-adequate diets . Weight gain, feed intake, and gain:feed values of chicks increased (P < 0.05) when deficient amino acids were serially supplemented to either the corn-peanut meal or SBM-dextrose diets . Phytase supplementation (600 and 1,200 U/kg) to the corn-peanut meal diet resulted in no significant differences in weight gain, feed intake, or gain:feed values of chicks when the diet was either deficient or adequate in amino acids . However, phytase supplementation (1,200 U/kg) produced significant increases (P < 0.05) in gain:feed values, but not weight gain, of chicks when they were fed the amino acid-deficient, but not the amino acid-adequate, SBM-dextrose diet . This gain:feed response to phytase supplementation of the amino acid-deficient SBM-dextrose diet occurred in both crossbred (New Hampshire x Columbian) and commercial (Ross x Hubbard) chicks . A digestibility assay was also performed using cecectomized roosters fed dehulled SBM containing three levels of phytase (0, 600, and 1,200 U/kg) . When averaged across nine essential amino acids and cystine, true amino acid digestibility (TAAD) values were increased by approximately 2% when 1,200 U/kg phytase was included with SBM and administered to cecectomized roosters . However, neither TAAD values nor TMEn were significantly improved by the phytase addition.

J Anim Sci, 1997 Feb, 75(2), 490 - 501
Forage intake by and site and extent of digestion in beef cattle grazing midgrass prairie rangeland or plains bluestem pasture throughout the summer; Gunter SA et al.; Eight beef steers fitted with esophageal (four steers/pasture) and 12 beef calves fitted ruminal and duodenal (six calves/pasture; beginning BW = 267 +/- 6 kg) cannulas grazed either midgrass prairie rangeland (excellent range condition; MIDGRASS) or plains bluestem (Bothriochloa ischaemum var . Plains) pasture (BLUESTEM) during mid-May, late June, mid-August, and mid-October of 1990 and 1991 in order to compare nutrient intake and digestion . Forage OM intake (OMI) by cattle grazing MIDGRASS or BLUESTEM was similar (P > .05) in June and August . In May and October, cattle grazing MIDGRASS consumed more (P < .05) OM than cattle grazing BLUESTEM . The extent of true ruminal OM digestion was similar (P > .05) between forage types except in October 1991, when the extent of digestion for BLUESTEM was greater (P < .05) than for MIDGRASS . The N intake by cattle interacted by year and forage (P < .05) . Nitrogen intake by cattle grazing MIDGRASS tended to be lower in June and August than in May and October . The N intake by cattle grazing BLUESTEM peaked (P < .05) in August during 1990; however, N intake was lowest (P < .05) in August during 1991 . Duodenal non-ammonia N (NAN) flow was higher (P < .05) in cattle grazing BLUESTEM than in cattle grazing MIDGRASS from May through August; however, duodenal NAN flow in cattle grazing BLUESTEM was lower (P < .05) in October 1991 . Duodenal microbial N synthesis (grams/day) responded quadratically (P < .05) to total ruminal OM digestion (kilograms/day) . Extent of true ruminal N digestion of both forages decreased (P < .05) as forage became more mature and lower in total N . Midgrass prairie seemed superior to BLUESTEM in May and October because of higher energy intakes and BLUESTEM seemed to be a good alternative to MIDGRASS during June through August, suggesting that these forages would make excellent complements . Furthermore, these data suggest that, in cattle grazing either forage, duodenal NAN flow was disproportionately high relative to energy intake.

Antonie Van Leeuwenhoek, 1997 Feb, 71(1-2), 143 - 50
Biodiversity within hot spring microbial mat communities: molecular monitoring of enrichment cultures; Ward DM et al.; We have begun to examine the basis for incongruence between hot spring microbial mat populations detected by cultivation or by 16S rRNA methods . We used denaturing gradient gel electrophoresis (DGGE) to monitor enrichments and isolates plated therefrom . At near extincting inoculum dilutions we observed Chloroflexus-like and cyanobacterial populations whose 16S rRNA sequences have been detected in the 'New Pit' Spring Chloroflexus mat and the Octopus Spring cyanobacterial mat . Cyanobacterial populations enriched from 44 to 54 degrees C and 56 to 63 degrees C samples at near habitat temperatures were similar to those previously detected in mat samples of comparable temperatures . However, a lower temperature enrichment from the higher temperature sample selected for the populations found in the lower temperature sample . Three Thermus populations detected by both DGGE and isolation exemplify even more how enrichment may bias our view of community structure . The most abundant population was adapted to the habitat temperature (50 degrees C), while populations adapted to 65 degrees C and 70 degrees C were 10(2)- and 10(4)-fold less abundant, respectively . However, enrichment at 70 degrees C favored the least abundant strain . Inoculum dilution and incubation at the habitat temperature favored the more numerically relevant populations . We enriched many other aerobic chemoorganotrophic populations at various inoculum dilutions and substrate concentrations, most of whose 16S rRNA sequences have not been detected in mats . A common feature of numerically relevant cyanobacterial, Chloroflexus-like and aerobic chemorganotrophic populations, is that they grow poorly and resist cultivation on solidified medium, suggesting plating bias, and that the medium composition and incubation conditions may not reflect the natural microenvironments these populations inhabit.

Immunity, 1997 Feb, 6(2), 187 - 97
The mannose receptor delivers lipoglycan antigens to endosomes for presentation to T cells by CD1b molecules; Prigozy TI et al.; We have characterized the CD1b-mediated presentation pathway for the mycobacterial lipoglycan lipoarabinomannan (LAM) in monocyte-derived antigen-presenting cells . The macrophage mannose receptor (MR) was responsible for uptake of LAM . Antagonism of MR function inhibited both the internalization of LAM and the presentation of this antigen to LAM-reactive T cells . Intracellular MRs were most abundant in early endosomes, but they also were located in the compartment for MHC class II antigen loading (MIIC) . Internalized LAM was transported to late endosomes, lysosomes, and MIICs . MRs colocalized with CD1b molecules, suggesting that the MR could deliver LAM to late endosomes for loading onto CD1b . LAM and CD1b colocalized in organelles that may be sites of lipoglycan antigen loading . This pathway links recognition of microbial antigens by a receptor of the innate immune system to the induction of adaptive T cell responses.

Microbiology, 1997 Feb, 143 ( Pt 2), 449 - 55
Investigation of space flight effects on Escherichia coli and a proposed model of underlying physical mechanisms; Klaus D et al.; Previous investigations have reported that space flight may produce a stimulating effect on microbial metabolism; however, the specific underlying mechanisms associated with the observed changes have not yet been identified . In an effort to systematically evaluate the effect of space flight on each phase of microbial growth (lag, exponential and stationary), a series of experiments was carried out using in vitro suspension cultures of Escherichia coli aboard seven US Space Shuttle missions . The results indicated that, as a result of space flight, the lag phase was shortened, the duration of exponential growth was increased, and the final cell population density was approximately doubled . A model was derived from these cumulative data in an attempt t associate gravity-dependent, extracellular transport phenomena with unique changes observed in each specific phase of growth . It is suggested that a cumulative effect of gravity may have a significant impact on suspended cells via their fluid environment, where an immediate, direct influence of gravity might otherwise be deemed negligible.

Mayo Clin Proc, 1997 Feb, 72(2), 149 - 59
Prophylactic antibiotics in cataract operations; Liesegang TJ; The rationale for prophylactic antibiotics in cataract operations must be continually reevaluated in light of cost-effectiveness and adverse reactions . The principles learned from wound infections associated with general surgical procedures should be applied to the limited knowledge about the rare event of endophthalmitis . Herein the literature on experimental and clinical wound infections in general surgical procedures is reviewed, with analysis of microbial flora, pathophysiology of wound infections, and pharmacokinetics of antibiotics . Experimental and clinical studies on prophylactic antibiotics to prevent endophthalmitis are reviewed, including information on topically applied antibiotics, chemical antisepsis, and administration of subconjunctival, intracameral, and systemic antibiotics . In addition, the benefits, limitations, and risks of the various types of prophylactic antibiotics are discussed . Because of the limited data on prophylactic antibiotics in cataract operations, providing dogmatic statements is difficult . General recommendations are offered based on the currently available literature, and a stratified approach is suggested based on wound construction and number of anterior segment maneuvers.

Biotechnol Appl Biochem, 1997 Feb, 25 ( Pt 1), 13 - 8
Stability assessment of lyophilized intravenous immunoglobulin after reconstitution in glass containers and poly(vinyl chloride) bags; Parti R et al.; Human intravenous immunoglobulin (IGIV) has been in use for the past 20 years . This biological product is commonly provided in liquid or lyophilized dosage form . When the lyophilized product is rehydrated, it is usually administered within 2-3 h from time of complete dissolution . While this practice is advisable whenever possible, occasionally the patient or care-giver may need to delay the infusion . Hence, a study of the stability of lyophilized IGIV after reconstitution with water for injection was conducted . The reconstituted product was stored either in its original glass container or pooled into poly(vinyl chloride) (PVC) bags . The effect of extended storage on the active ingredient (IgG), excipients (glucose, albumin) and extractables {sodium from glass vials, and di-(2-ethyl-hexyl) phthalate and cyclohexanone from PVC bags} was evaluated . The stability of the active ingredient was evaluated by physico-chemical tests (molecularsize distribution, pH, appearance, total protein), monitoring titres of a specific antibody (hepatitis B surface antigen) and an antibody functional test (bacterial opsonization) . To evaluate the risk of microbial contamination during reconstitution and pooling procedures, sterility, pyrogen and animal-safety tests were included in the protocol . The potential of IgG polymerizing in solution during storage and subsequent complement activation was evaluated by assaying for non-specific binding of complement (anti-complement activity) . Results show that aseptically reconstituted IGIV is stable and remains sterile up to 48 h at 5 degrees C . The reconstituted product was also found to be stable at room temperature (25 degrees C) up to 12 h.

Clin Exp Immunol, 1997 Feb, 107(2), 306 - 11
Diagnostic value of CD45RO expression on circulating T lymphocytes of fetuses and newborn infants with pre-, peri- or early post-natal infections; Bruning T et al.; We examined the expression of the CD45RO antigen, which characterizes the antigen primed/memory phenotype of T lymphocytes, as a marker for congenital infection in blood samples of newborns and fetuses . CD45RO expression on T cells was determined by triple-colour fluorescence flow cytometry . In total 537 blood samples of newborns and infants up to an age of 3 months and 89 fetal blood samples from gestational weeks 19-31 were analysed . Of the newborns and infants, 74 had a clinically, serologically and/or antigenically evident infection, and four of the fetuses had a confirmed intra-uterine infection . In 35 infants with acute predominantly bacterial infections such as sepsis or pneumonia, 17 (48.6%) had elevated CD45RO(bright) expression . In 39 infants with proven pre-, peri- or early post-natal infections with toxoplasmosis, cytomegalovirus (CMV), rubella, herpes simplex virus (HSV) or human herpes virus type 6 (HHV6), 25 (64.1%) exhibited enhanced CD45RO(bright) expression . Three of four fetuses with confirmed intra-uterine infection (three with CMV, one with parvovirus B19) exhibited elevated CD45RO(bright) expression . The specificity of the CD45RO assay for detecting microbial infections was 94.6% for newborns and infants up to 3 months and 90.6% for fetuses . It is concluded that elevated numbers of CD45RO(bright) T cells in infants up to 3 months of age strongly suggest an infection . However, the sensitivity of the CD45RO assay is not sufficient to enable the test to be used as a general marker for prescreening infants to detect pre-, peri- or early post-natally acquired infections.

J Histochem Cytochem, 1997 Feb, 45(2), 189 - 201
Upregulation of alpha 9 integrin and tenascin during epithelial regeneration after debridement in the cornea; Stepp MA et al.; Stratified epithelia are exposed to abrasive forces and are required to respond rapidly to injury to minimize fluid loss and the risk for microbial infection . Healing involves a cell migratory phase to reestablish barrier function and cell proliferation to restratify the epithelium . Cell migration during re-epithelialization involves cell sliding, termed sheet movement, during which cells retain their cell-cell junctions while dynamically altering their shape and cell-substrate interactions to permit movement across the exposed wound bed . Proteins of the integrin family of receptor molecules modulate cell shape, cell migration, and signal transduction in many cell types . In epithelial cells, integrins of the beta 1 family have been implicated in regulating cell proliferation and differentiation, alpha 9 beta b1 is one of the newer members of the integrin beta family and has been recently shown to function as a tenascin receptor . Although little is known about its function in vivo, studies in developing mouse cornea and eyelid suggest that it may play a role in epithelial differentiation . Using a debridement wound model in the mouse cornea, we show in this study that (a) in response to small debridement wounds that close without cell proliferation, alpha 9 integrin protein and mRNA are not induced during migration but are induced during restratification, (b) larger debridement wounds that require cell proliferation to generate the cells necessary for sheet movement result in a dramatic induction of alpha 9 protein and its mRNA during both migration and restratification, and (c) tenascin, an alpha 9 beta 1 ligand, accumulates beneath epithelial cells during restratification but not during cell migration . Therefore, alpha 9 integrin protein production and tenascin accumulation are dynamically regulated in response to corneal epithelial injury.

FEBS Lett, 1997 Jan 27, 402(1), 4 - 8
Does selective gene activation direct evolution?
Wright BE.
Mechanisms may have evolved such that the unique metabolic reaction to a particular environmental stress results in higher mutation rates of those genes most likely to solve the problem . Evidence is presented indicating that the environment in effect directs the evolution of organisms by (1) presenting various kinds of stress resulting in metabolic activities that target particular genes for increased rates of transcription and mutation, and (2) selecting among this specifically enriched mutant population those variants that alleviate the imposed stress . This process should be ongoing and would be expected to accelerate the rate of microbial evolution.

J Exp Med, 1997 Jan 20, 185(2), 207 - 18
Absence of respiratory burst in X-linked chronic granulomatous disease mice leads to abnormalities in both host defense and inflammatory response to Aspergillus fumigatus; Morgenstern DE et al.; Mice with X-linked chronic granulomatous disease (CGD) generated by targeted disruption of the gp91phox subunit of the NADPH-oxidase complex (X-CGD mice) were examined for their response to respiratory challenge with Aspergillus fumigatus . This opportunistic fungal pathogen causes infection in CGD patients due to the deficient generation of neutrophil respiratory burst oxidants important for damaging A . fumigatus hyphae . Alveolar macrophages from X-CGD mice were found to kill A . fumigatus conidia in vitro as effectively as alveolar macrophages from wild-type mice . Pulmonary disease in X-CGD mice was observed after administration of doses ranging from 10(5) to 48 spores, none of which produced disease in wild-type mice . Higher doses produced a rapidly fatal bronchopneumonia in X-CGD mice, whereas progression of disease was slower at lower doses, with development of chronic inflammatory lesions . Marked differences were also observed in the response of X-CGD mice to the administration of sterilized Aspergillus hyphae into the lung . Within 24 hours of administration, X-CGD mice had significantly higher numbers of alveolar neutrophils and increased expression of the proinflammatory cytokines IL-1 beta and TNF-alpha relative to the responses seen in wild-type mice . By one week after administration, pulmonary inflammation was resolving in wild-type mice, whereas X-CGD mice developed chronic granulomatous lesions that persisted for at least six weeks . This is the first experimental evidence that chronic inflammation in CGD does not always result from persistent infection, and suggests that the clinical manifestations of this disorder reflect both impaired microbial killing as well as other abnormalities in the inflammatory response in the absence of a respiratory burst.

J Clin Invest, 1997 Jan 15, 99(2), 336 - 41
Interferon-gamma differentially regulates interleukin-12 and interleukin-10 production in leprosy; Libraty DH et al.; The ability of monocytes to influence the nature of the T cell response to microbial pathogens is mediated in part by the release of cytokines . Of particular importance is the release of IL-12 and IL-10 by cells of the monocyte/macrophage lineage upon encountering the infectious agent . IL-12 promotes cell mediated immunity (CMI) to intracellular pathogens by augmenting T-helper type 1 responses, whereas IL-10 downregulates these responses . The ability of IFN-gamma to modulate the balance between IL-12 and IL-10 production was examined by studying leprosy as a model . In response to Mycobacterium leprae stimulation, IFN-gamma differentially regulated IL-12 and IL-10 production resulting in upregulation of IL-12 release and downregulation of IL-10 release . Furthermore, we determined that the mechanism by which IFN-gamma downregulates IL-10 was through the induction of IL-12 . The data suggest a model of lymphocyte-monocyte interaction whereby the relative presence or absence of IFN-gamma in the local microenvironment is a key determinant of the type of monocyte cytokine response, and hence the degree of CMI in the host response to infection.

MMWR Morb Mortal Wkly Rep, 1997 Jan 10, 46(1), 4 - 8
Outbreaks of Escherichia coli O157:H7 infection and cryptosporidiosis associated with drinking unpasteurized apple cider--Connecticut and New York, October 1996; Characterization and functional analysis of 12 naturally occurring reactive site variants of serpin-1 from Manduca sexta; Department of Biochemistry, Kansas State University, Manhattan 66506, USASerpin gene-1 from the tobacco hornworm, Manduca sexta, encodes, through alternative exon usage, 12 reactive site variants (Jiang, H., Wang, Y . and Kanost, M . R., (1994) J . Biol . Chem . 269, 55-58; Jiang, H., Wang, Y., Huang, Y., Mulnix, A . B., Kadel, J., Cole, K., and Kanost, M . R . (1996) J . Biol . Chem . 271, 28017-28023) . These 43-kDa proteins differ from each other only in their COOH-terminal 39-46 residues, which include the reactive site . To test the hypothesis that these proteins are proteinase inhibitors of diverse selectivities and to begin to elucidate their physiological functions, we expressed the 12 serpin-1 variants in Escherichia coli . Seven of the variants inhibited mammalian serine proteinases, with association rate constants comparable with those of human serpins . Serpin-1A, with a P1 Arg residue, inhibited both trypsin and plasmin . Serpin-1B (P1 Ala) and serpin-1F (P1 Val) inhibited porcine pancreatic elastase and human neutrophil elastase . Serpin-1H, -1K, and -1Z, all with a Tyr residue at the P1 position, inhibited chymotrypsin and cathepsin G . Serpin-1I (P1 Leu) inhibited both elastase and chymotrypsin . Nine of the serpin variants were active as inhibitors of microbial serine proteinases, including subtilisin Carlsberg, proteinase K, and two proteinases secreted by an entomopathogenic fungus, Metarhizium anisopliae . In addition, one of the serpin variants, serpin-1J, strongly inhibited activation of M . sexta hemolymph phenoloxidase, a pathway involving a serine proteinase cascade . This pathway is a component of the defensive response of insects to microbial infection . These results suggest that the products of M . sexta serpin gene-1 may be important in regulating both exogenous and endogenous serine proteinases in hemolymph.

J Biol Chem, 1997 Jan 10, 272(2), 961 - 5
Isolation and characterization of mycophenolic acid-resistant mutants of inosine-5'-monophosphate dehydrogenase; Farazi T et al.; Mycophenolic acid (MPA) is a potent and specific inhibitor of mammalian inosine-monophosphate dehydrogenases (IMPDH); most microbial IMPDHs are not sensitive to MPA . MPA-resistant mutants of human IMPDH type II were isolated in order to identify the structural features that determine the species selectivity of MPA . Three mutant IMPDHs were identified with decreased affinity for MPA The mutation of Gln277 --> Arg causes a 9-fold increase in the Ki of MPA, a 5-6-fold increase in the Km values for IMP and NAD, and a 3-fold decrease in kcat relative to wild type . The mutation of Ala462 --> Thr causes a 3-fold increase in the Ki for MPA, a 2.5-fold increase in the Km for NAD, and a 1.5-fold increase in kcat . The combination of these two mutations does not increase the Ki for MPA, but does increase the Km for NAD 3-fold relative to Q277R and restores kcat to wild type levels . Q277R/A462T is the first human IMPDH mutant with increased Ki for MPA and wild type activity . The third mutant IMPDH contains two mutations, Phe465 --> Ser and Asp470 --> Gly . Ki for MPA is increased 3-fold in this mutant enzyme, and Km for IMP is also increased 3-fold, while the Km for NAD and kcat are unchanged . Thus increases in the Ki for MPA do not correlate with changes in Km for either IMP or NAD, nor to changes in kcat . All four of these mutations are in regions of the IMPDH that differ in mammalian and microbial enzymes, and thus can be structural determinants of MPA selectivity.

World Health Stat Q, 1997, 50(1-2), 51 - 6
Chronic health effects of microbial foodborne disease; Bunning VK et al.; The acute effects of foodborne disease are sometimes not the end of the illness . Several significant foodborne pathogens are capable of triggering chronic disease, and even permanent tissue or organ destruction, probably via immune mechanisms . Arthritis, septic and reactive, inflammatory bowel disease, haemolytic uraemic syndrome, Guillain-Barre syndrome, and possible several autoimmune disorders can be triggered by foodborne pathogens or their toxins . Research is needed to more fully understand the mechanisms by which the immune system is inappropriately activated by these common foodborne disease-causing agents.

World Health Stat Q, 1997, 50(1-2), 5 - 11
Global estimation of foodborne diseases; Motarjemi Y et al.; Foodborne diseases are one of the most widespread health problems, but because of weaknesses in foodborne disease surveillance and variation in reporting systems between countries, it is difficult to make an estimation of their true incidence . This paper describes the constraints in the collection of information on the incidence and/or prevalence of foodborne diseases, including investigation and reporting at national and international levels . It also makes an attempt to semiquantify the occurrence of foodborne diseases of microbial and parasitical origin in different regions of the world.

Indian J Exp Biol, 1997 Jan, 35(1), 1 - 17
Enzymes that regulate ethylene levels--1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, ACC synthase and ACC oxidase; Penrose DM et al.; The plant enzymes, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase, catalyze essential steps in the biosynthesis of the phytohormone ethylene; the microbial enzyme ACC deaminase catalyses the hydrolytic cleavage of ACC, the immediate precursor of ethylene, and is therefore an inhibitor of ethylene biosynthesis . In this manuscript, the biochemical properties and mechanisms of these three enzymes and the genes that encode them are examined and compared . Despite the fact that ACC oxidase and ACC deaminase both act on the same substrate, i.e., ACC, these two enzymes and the mechanisms that they employ are quite different . Conversely, although ACC synthase catalyses the synthesis of ACC and ACC deaminase catalyses its hydrolysis, these enzymes share a number of important physical and biochemical properties.

Adv Pediatr, 1997, 44, 43 - 72
Bacterial adhesins: determinants of microbial colonization and pathogenicity; St Geme JW 3rd; Bacterial adhesins are a critical determinant of microbial colonization and are fundamental to disease pathogenesis . In this chapter, I have reviewed certain paradigms that exist with respect to structure, variation of expression, and biologic activity . No two adhesins are identical, reflecting the fact that each organism has a distinct ecological niche and is exposed to a different set of evolutionary pressures . Continued investigation is likely to identify additional paradigms and novel nuances . The hope is that we might use all this information to improve our approach to the treatment and prevention of bacterial disease.

Psychoneuroendocrinology, 1997, 22 Suppl 1, S95 - 101
What are ago-antagonistic couples? Their role in normal and pathological situations . Therapeutical consequences; Nunez EA et al.; Two classes of steroid hormones are successively produced following a microbial infection stress in rat and man . First there are those of attenuation and acceptation, the glucocorticoids and progestins, which correspond to the temporization phase of reaction to stress . Secondly, there are those of rejection or creative reinforcement, namely the adrenal androgens converted in certain circumstances to estrogens by aromatization, which are necessary to fight against or accept the stressor . We suggest that these two classes of signal carrier molecules function as agonistic-antagonistic couples which work to prevent the organism from going too far in the direction of attenuation-acceptation or, on the contrary, in the direction of rejection-reinforcement . The presence of agonistic-antagonistic couples can be identified as regulating numerous other steps in the signal networks . Dysfunctions of such couples result in pathological situations, characterized by an imbalance in the concentration and correspondingly in the biological activity of one of the partners due to a change in the 'equilibrium constant' of the ago-antagonistic couple, changes in the level of synthesis or catabolism of one of the partners, the presence in adequate time and location of the partners, or the deficiency of the receptor of at least one of the partners . Different 'paradoxical' therapeutical strategies are envisaged to reequilibrate the imbalance.

Scand J Infect Dis, 1997, 29(3), 291 - 6
Amniotic fluid leukocytes and leukocyte esterase activity in parturients delivered by caesarean section; Keski-Nisula L et al.; Amniotic fluid specimens from parturients undergoing caesarean delivery were examined for leukocytes and leukocyte esterase activity, as well as for amniotic fluid bacteria and mycoplasmas by cultivation . The aim of this study was to evaluate the intrauterine environment in noninfected parturients and the associations between leukocyte test results, amniotic fluid microbial colonization and postcaesarean endometritis . Samples were obtained by direct aspiration at operation from 289 parturients with no clinical intrauterine infection . Among the total study population, leukocytes were found in 41% of the amniotic fluid samples by Gram staining and in 39% of the samples by the leukocyte esterase activity test . Leukocytes and leukocyte esterase activity were observed significantly more often in the amniotic fluids of parturients undergoing operation after onset of labour or ruptured membranes compared with those operated upon with intact membranes and no labour (p < 0.0001 and p < 0.0001) . Of 255 amniotic fluid cultures, microbial colonization was observed in 82 (32%) parturients . Positive results in the leukocyte tests were associated significantly with amniotic fluid microbial colonization among parturients who underwent operation with intact membranes, or who underwent operation after rupture of the membranes and had cervical dilatation of < 5 cm at the operation (Gram stain: p < 0.0001; leukocyte esterase: p < 0.003) . If cervical dilatation was > or = 5 cm, no such association was observed . In the population studied, endometritis developed in 2% and 4% of the parturients with positive test results . Thus, neither the presence of leukocytes nor detected leukocyte esterase activity were predictive of subsequent postoperative endometritis . In the detection of amniotic fluid microbial colonization, the tests functioned best in non-laboring parturients with intact membranes and in those operated on at the early stage of labour.

Bacteriol Virusol Parazitol Epidemiol, 1997 Jan-Jun, 42(1-2), 65 - 9
{The effect of products of plant and microbial origin on phagocytic function and on the release of oxygen free radicals by mouse peritoneal macrophages}; Dolganiuc A et al.; The effect of in vivo stimulation with an aqueous extract obtained from roots of Symphytum officinale and Cantastim on mouse peritoneal macrophages was investigated . The results obtained showed that these products initially activated the respiratory burst of the cells and later inhibited it, activating the synthesis of catalase, SOD etc . These data suggest that macrophages challenged by various ingested antigens destroy them initially through oxygen dependent mechanisms and later through enzymatic digestion in order to retain unimpaired their epitopes.

Arch Tierernahr, 1997, 50(2), 173 - 85
Rumen dry matter and crude protein degradability of extracted or untreated oilseeds and Leucaena leucocephala leaves; Gralak MA et al.; A study was undertaken to determine the rumen DM and CP degradability characteristics of soyabean, canola seed, peanut, palm kernel and Leucaena leucocephala leaves . The oilseeds were either treated with n-hexane to extract the fat or left untreated . Nylon bags were incubated in each of four rumen cannulated sheep for 0, 2, 4, 6, 12, 24 and 48 h . Animals were fed on a diet consisting of meadow hay (ad libitum) and 150 g of concentrate twice daily . Fat extraction caused a decrease (P < or = 0.05) in DM disappearance of soyabean at 0, 2, 4, 6 and 12 h and of peanuts at all incubation times . CP disappearance from peanuts was reduced (P < or = 0.05) as a result of fat extraction at 0, 2, 4, 6 and 12 h . Fat extraction of canola seed increased CP disappearance at 0, 2, 4, 6 and 24 h (P < or = 0.05) . However, in the case of defatted canola seed, an increase in DM disappearance (P < or = 0.05) was observed in the first 4 incubation times and a decrease (P < or = 0.05) in the later times . Fat extraction increased (P < or = 0.05) DM disappearance of palm kernel at 0 and 48 h, but reduced it at 4, 6 and 24 h . CP disappearance of palm kernel was improved by treatment (P < or = 0.05) at 0, 4, 24 and 48 h and decreased at 12 h . In the case of palm kernel the largest differences in DM and CP disappearance occurred between the 24 and 48 h incubation times . Degradability characteristics for DM and CP of full-fat soyabean, canola seed and peanut were comparable to those of the full fat samples . Effective DM degradability of soyabean, canola seed and peanuts was 72.2 and 71.9; 74.1 and 66.8; and 85.9 and 70.8 for full fat and extracted feeds, respectively . Effective CP degradability was similar in all oilseeds with the exception of the extracted canola seed . Therefore, the incorporation of full-fat soyabean, canola seed and peanut into ruminant rations can be considered as a means of increasing the energy balance . Both palm kernel DM and CP degradabilities were characterized by slow rates of degradation by negative values "b" . This suggests the predominance of microbial colonization over disappearance during incubation . DM and CP disappearance of Leucaena leucocephala leaves originating from Cuba were lower than those from Nigeria . Degradability characteristics for CP and DM of Cuban leucaena leaves showed that the linear model resulted in a better fit than the exponential one.

Free Radic Biol Med, 1997, 23(3), 480 - 8
The effects of ozone on antioxidant responses in plants; Sharma YK et al.; The response of plants to ozone exposure includes a number of physiological and biochemical changes that are the direct result of selective increases or decreases in gene expression and the resulting changes in the accumulation of the corresponding protein products . Major classes of ozone-induced proteins include antioxidant enzymes and a number of stress-related proteins associated with other biotic and abiotic stresses . In particular, there is a significant overlap in the pattern of gene induction observed in ozone-treated plants and plants exhibiting pathogen defense responses . Current knowledge concerning the specific molecular events associated with the alterations of gene expression caused by ozone and the precise roles of ozone-induced proteins in conferring tolerance to ozone is rather limited . This review summarizes some of the recent results that have been obtained concerning the molecular basis of ozone-induced responses in plants, with an emphasis on studies of the model plant system, Arabidopsis thaliana . These studies demonstrate that ozone-induced responses are caused in part by the activation of a salicylic acid dependent signaling pathway that is also required for the expression of resistance to microbial pathogens.

Arch Tierernahr, 1997, 50(1), 63 - 74
Preileal digestibility of coconut fat and soybean oil in horses and their influence on metabolites of microbial origin of the proximal digestive tract; Meyer H et al.; Three horses (approximately 190 kg BW) fitted with a permanent fistula at the end of the jejunum were used . To a control diet (1/3 hay, 2/3 mixed feed) one of two fat types (coconut fat or soybean oil) were added at 2 levels resulting in fat intakes of 0.1 g (control diet) to 0.5 or 1 g/kg BW 0.5 d, respectively . Each experimental period consisted of 2 weeks adaptation, 2 days of breath tests (before and hourly after the morning meal) and 5 days sampling of chyme . Crude fat, crude protein, concentrations of organic acids (SCFA, lactic acid), pH, and the minerals calcium, magnesium and phosphorus were determined in the chyme; H2 and CH4 in the expired air . The following results were obtained: 1) Fat feeding significantly (P < 0.01) stimulated (independent of amount or kind of fat) the jejunoileal flow of chyme . 2) Preileal fat digestibility increased significantly (P < 0.01) from 30-38% during the control periods to 73-80% (moderate fat intake) and 82-86% (high fat intake) . Differences between the fat sources were not significant . 3) Fat addition resulted dose dependent in a reduction (P < 0.05) of lactic acid as well as SCFA concentrations of chyme (at 5th h postprandial) . 4) Fat intake caused a reduction in the H2-concentration of the exhaled air (P < 0.05) . Such effect was not found with the CH4-concentration, except the high soybean oil level which tended to reduce the concentration . 5) The addition of fat had no significant effects on preileal net absorption of magnesium and calcium, whilst the net secretion of phosphorus significantly increased (P < 0.01) . 6) The preileal protein digestibility (control periods 48-53%) was slightly decreased (P < 0.05), due to the fat inclusion.

Int Rev Immunol, 1997, 14(1), 89 - 96
New perspective on Behçet's disease; Sakane T; There are many distinct differences between Behcet's disease of Silk Route and that of outside Silk Route; genetic factors, role of neutrophils, and severity of this disease . We have thus emphasized that we prefer the term "Behcet's syndrome" rather than "Behcet's disease" . In this chapter, Behcet's disease seen along the Silk Route will be mainly discussed . HLA-B51 molecules themselves may be responsible, at least in part, for the neutrophil hyperfunction in Behcet's disease; a significant correlation was observed between the neutrophil hyperfunction and the possession of HLA-B51 phenotype, regardless of the presence of the disease, in both humans and HLA-B transgenic mice . T cells in this disease, proliferated vigorously in response to a specific peptide of human heat shock protein (HSP)-60; however, T cells from normal subjects or patients with rheumatoid arthritis, did not . This peptide has the amino acid sequence of 336-351 of human HSP-60, which is similar, but not identical to specific peptide of mycobacterial HSP-65 . We have further analyzed T cell receptor (TCR) usage of HSP-responsive T cells by means of TCR V beta subfamily specific monoclonal antibodies and polymerase chain reaction and single strand conformation polymorphism-based technique . We found that T cells with specific TCR V beta subfamilies proliferated and increased in number in response to the peptide by an antigen-specific fashion . The result of recurrent exposure to the HSP may break the tolerance to self-HSP, and provoke T cell responses to self- and microbial-HSP . Such T cells produced Th1-like proinflammatory and/or inflammatory cytokines . This leads to tissue injury, possibly via delayed-type hypersensitivity reaction, macrophage activation, and activation and/or recruitment of neutrophils . Our data shed a new light on the autoimmune nature of Behcet's disease; a novel multistep molecular mimicry mechanisms may induce and/or exacerbate Behcet's disease by bacterial antigens that activate T cells previously educated by self-peptides of HSP . This would lead to positive selection of autoreactive T cells in this disease.

Scand J Gastroenterol Suppl, 1997, 223, 43 - 5
New developments in Helicobacter pylori eradication therapy; Pounder RE; BACKGROUND: The optimal strategy for the eradication of Helicobacter pylori has yet to be determined . This paper summarizes some of the latest treatment strategies for eradicating H . pylori infection . METHOD: Literature review by author . RESULTS: Successful eradication of H . pylori requires the use of combination therapy involving control of gastric acid secretion together with anti-microbial drugs . The two most popular strategies use either a proton-pump inhibitor or an H2 antagonist plus two antibiotics-usually metronidazole, amoxycillin or clarithromycin . Ranitidine bismuth citrate is a co-precipitate of ranitidine hydrochloride and bismuth citrate, producing a high rate of H . pylori eradication when combined with clarithromycin . Future development of this combination may involve the addition of a second antibiotic . CONCLUSION: Modern combination therapy usually results in an 80-95% H . pylori eradication rate in compliant patients.

Chirality, 1997, 9(3), 254 - 60
A mechanistic investigation of the microbial chiral inversion of 2-phenylpropionic acid by Verticillium lecanii; Thomason MJ et al.; Previous investigations have described the development of nongrowing suspensions of Verticillium lecanii as a microbial model of the mammalian chiral inversion of the 2-arylpropionic acids (2-APAs) . Mechanistic studies in mammals have shown that inversion involves loss of the alpha-methine proton but retention of the original atoms at the beta-methyl position, and a mechanism has been proposed involving enzymatic epimerisation of acyl-CoA thioester derivatives of the substrate . Inversion of the 2-APAs by V . lecanii exhibits extensive intersubstrate variation in the presence, rate, extent, and direction of inversion, which are different from those observed in mammalian systems, possibly indicating differences in the mechanism of inversion between mammalian and microbial cells . This study involved the investigation of proton/deuterium exchange by 1H-nuclear magnetic resonance following incubation of deuterated derivatives of 2-phenylpropionic acid (2-PPA), a model compound, in cell suspensions of V . lecanii and incubation of undeuterated 2-PPA in cell suspensions containing D2O . The results indicated that the inversion of 2-PPA by V . lecanii also involved exchange of the alpha-methine proton but complete retention of the original atoms at the beta-methyl position . No kinetic deuterium isotope effect was observed, indicating that loss of the alpha-methine proton is not the rate-limiting step of the inversion process . This suggests that the observed differences between microbial and mammalian systems probably involve the stereoselective acyl-CoA thioester formation step and not the subsequent epimerisation of the resultant diastereomers.

Crit Rev Oral Biol Med, 1997, 8(2), 217 - 36
Factors affecting IL-1-mediated collagen metabolism by fibroblasts and the pathogenesis of periodontal disease: a review of the literature; Havemose-Poulsen A et al.; Fibroblasts have been studied extensively for their contribution to connective tissue destruction in diseases where the metabolism of extracellular matrix components plays an essential part in their pathogenesis . A considerable dissolution, especially of collagen fibrils, is a well-known characteristic of the periodontal ligament and the gingival connective tissue in microbial-induced periodontal disease . Fibroblasts, responsible for the assembly of the extracellular matrix, are capable of responding directly to oral microbial challenges or indirectly, following activation of the host immune response, and can alter the composition of connective tissue in several ways: synthesis of inflammatory mediators, their receptors and antagonists; fibroblast proliferation; collagen synthesis; phagocytosis of collagen fibrils; and synthesis of proteolytic enzymes, including matrix metalloproteinases and their corresponding inhibitors . The contributions of these cellular fibroblastic properties to the pathogenesis of periodontal disease are reviewed in the context of the cytokine, interleukin-1, as the inflammatory regulator.

Scand J Gastroenterol Suppl, 1997, 222, 65 - 7
The metabolic importance of unabsorbed dietary lipids in the colon; Vonk RJ et al.; Digestion and absorption of lipids is a highly efficient process . From Western diets about 95% will be absorbed . This implies that together with lipids from endogenous sources 6-8 g of lipids will enter the colon daily . This input significantly increases during various lipid malabsorption syndromes . It has long been assumed that the biological fate of unabsorbed lipids is physiologically not relevant . However, significant microbial lipid metabolism occurs . Circumstantial evidence is arising which supports a role of unabsorbed lipid metabolites in the development of colonic diseases . Lipid metabolites may act as detergents in the colon, leading to mucosal injury and reactive hyperproliferation, which in its turn could promote tumour development . Lipid metabolites could also be transformed in biological active metabolites, which have a tumour promoting potency . More mechanistic information is needed on the colonic metabolic fate of lipids in order to develop strategies for manipulating colonic flora in the prevention of lipid related colonic diseases.

Prikl Biokhim Mikrobiol, 1997 Jan-Feb, 33(1), 43 - 8
{Comparative characteristics of microbial proteases by the level of hydrolysis of protein substrates}; Rimareva LV et al.; Screening of enzyme preparations displaying a maximum proteolytic activity at pH 4.0-5.5 and effecting deep proteolysis of plant proteins was performed . Amyloprotooryzin prepared from Aspergillus oryzae 387 containing a complex of proteolytic enzymes was the most effective . The amino acid composition of the hydrolysates obtained was studied . Amyloprotooryzin increased the contents of amino acids by 108-227%, depending on the substrate used . The enzymatic complex of amyloprotooryzin was studied; in addition, proteases, alpha-amylase, exo-beta-glucanase, and xylanase were detected in the complex.

Arch Oral Biol, 1997 Jan, 42(1), 89 - 92
The relationship between microbial factors and gingival crevicular fluid glycosaminoglycans in human adult periodontitis; Smith AJ et al.; Counts of cultivable Porphyromonas gingivalis, assays of microbial proteases and the concentration in gingival crevicular fluid of proteoglycan metabolites were investigated at periodontitis and gingivitis sites in 16 patients with chronic adult periodontitis before and after treatment . Two periodontitis sites and two gingivitis sites were selected from each patient on the basis of a clinical examination . Gingival crevicular fluid from each site was analysed for the concentrations of the glycosaminoglycans chondroitin-4-sulphate and hyaluronan and subgingival plaque samples were analysed for cultivable P . gingivalis and microbial trypsin-like proteases assayed by benzoyl-DL-arginine-naphthylamide (BANA) hydrolysis . Significantly higher concentrations (p = 0.007) of chondroitin-4-sulphate were found at periodontitis than gingivitis sites but there was no significant difference in hyaluronan (p = 0.36) between these sites . Although the majority of periodontal sites were P . gingivalis-negative (23/32), there were significantly higher concentrations of chondroitin-4-sulphate (p = 0.05) and hyaluronan (p = 0.04) at the P . gingivalis-positive, compared to negative, periodontitis sites . At BANA-positive periodontitis sites there were also higher concentrations of chondroitin-4-sulphate (p = 0.0015) and hyaluronan (p = 0.0001) than at BANA-positive gingivitis sites . There was a significant decrease in concentrations of chondroitin-4-sulphate and hyaluronan at periodontitis sites after treatment . This study lends support to the hypothesis that P . gingivalis may be actively involved in the destruction of connective tissue components at culture-positive sites but shows that elevated concentrations of connective tissue breakdown products may occur in gingival crevicular fluid from periodontal sites where this organism is absent.

Biol Neonate, 1997, 71(4), 207 - 14
Bile acid concentrations in serum and duodenal aspirates of healthy preterm infants: effects of gestational and postnatal age; Boehm G et al.; In 41 healthy human-milk-fed preterm infants the preprandial total bile acid (BA) concentrations in serum and duodenal juice were simultaneous measured during the first 60 days of life . The infants were subdivided into four groups according to their gestational age: 6 infants with a gestational age of 27 and 28 weeks, 7 infants with a gestational age of 29 and 30 weeks, 21 infants with a gestational age of 31 and 32 weeks and 7 infants with a gestational age of 33 and 34 weeks . The BA levels were enzymatically determined using 3-alpha-hydroxysteroid dehydrogenase . In the duodenal juice, cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid and lithocholic acid were separately quantified by thin-layer chromatography . During the first month of life, the serum BA concentrations increased significantly with postnatal age (p < 0.01) but remained nearly constant during the second month of life . In the duodenal aspirates, the BA concentrations increased continuously up to the end of the observations period (p < 0.001) . In the duodenal aspirates, the CA/CDCA ratio was high immediately after birth and decreased significantly with increasing postnatal age (p < 0.001) . During the first weeks of life, the BA levels were preferentially conjugated with taurine, but in spite of the taurine-rich diet during the whole observation period the taurine/glycine ratio decreased with postnatal age (p < 0.001) . In all samples of duodenal juice, the sum of primary BA was > 98% of total 3-alpha-hydroxy-BA . These data indicate that the establishment of an intestinal microbial flora necessary for intestinal BA transformation and the development of the enterohepatic BA circulation lasts some months of postnatal life . The serum BA concentration reflects hepatic synthesis, intestinal absorption, renal excretion and hepatocellular transport into bile in a very complex way which may limit the diagnostic value of serum BA during this time . Additionally, a duodenal BA concentration below 4 mmol/l, as found in this study during the first 2 weeks of life, may be of clinical importance due to its possible effects on fat absorption.

Biochemistry (Mosc), 1997 Jan, 62(1), 28 - 37
Characterization of O-antigens from different strains of Pseudomonas syringae pv . tabaci; Zdorovenko GM et al.; O-Antigens (lipopolysaccharides, LPS) were isolated by NaCl extraction from microbial biomass of Pseudomonas syringae pv . tabaci and purified by ultracentrifugation . Individual structural components of the LPS macromolecule (O-specific polysaccharide (O-PS), core oligosaccharide, and lipid A) were obtained and characterized . Fatty acids 3-OH-C10:0, C12:0, 2-OH-C12:0, 3-OH-C12:0, C16:1, C16:0, C18:1, and C18:0 were identified in the lipid A composition . Glucosamine, ethanolamine, and phosphoethanolamine were found in the hydrophilic part of the lipid A macromolecule in all strains tested . Lipid A preparations contained phosphorus and amino acids . Rhamnose, glucose, glucosamine, 2-keto-3-deoxyoctulosonic acid, heptose, alanine, and phosphorus were identified as the main core components . The strains differed in O-PS structure . We describe the O-chain of LPS in strain P-28 . It contains repeating units of the following structure: {formula: see text} The O-PS structures of LPS from strains P-28 and 225 are identical, however, they differ substantially from that of strain 223 . Both structures from strains 223 and 225 were reported previously . Antibodies to antigenic epitopes of O-PS, core, and lipid A were revealed in O-serum against the whole bacterial cells . Correlation of O-PS structure with the serological grouping of strains was observed.

Adv Biochem Eng Biotechnol, 1997, 58, 45 - 87
Screening of novel microbial enzymes for the production of biologically and chemically useful compounds; Shimizu S et al.; Enzymes have been generally accepted as superior catalysts in organic synthesis . Micro-organisms in particular have been regarded as treasure sources of useful enzymes . The synthetic technology using microbial enzymes or micro-organisms themselves is called microbial transformation . In designing a microbial transformation process, one of the most important points is to find a suitable enzyme for the reaction of interest . Various kinds of novel enzymes for specific transformations have been discovered in micro-organisms and their potential characteristics revealed . This article reviews our current results on the discovery of novel enzymes for the production of biologically and chemically useful compounds, and emphasizes the importance of screening enzymes in a diverse microbial world.

PDA J Pharm Sci Technol, 1997 Jan-Feb, 51(1), 2 - 6
The impact of non-endotoxin LAL-reactive materials on Limulus amebocyte lysate analyses; Cooper JF et al.; Limulus amebocyte lysate (LAL) is activated by bacterial endotoxins and certain glucans (beta-D-glucan, LAL-RM) . The potential for conflicting inter-laboratory results for LAL tests exists because commercial LAL reagents are highly variable in response to LAL-reactive glucans . The nature of beta-D-glucan activation of LAL and means for rendering LAL non-responsive to glucan are reviewed to provide a background for resolving conflicting data . Kinetic LAL methods are particularly useful for screening materials potentially contaminated with glucan . The presence of beta-D-glucan in parenterals is uncommon and is likely limited to products exposed to microbial or cellulosic materials . A scheme is suggested for identifying LAL-reactive glucans and for LAL release-testing without glucan interference.

Blood Purif, 1997, 15(1), 54 - 60
Impact of terminal heat sterilization on the quality of peritoneal dialysis solutions; Martis L et al.; In order to meet the sterility requirements imposed by the various regulatory bodies around the world, peritoneal dialysis solutions are terminally heat-sterilized at an acid pH . There is growing concern that both acid pH and the glucose degradation products formed during terminal heat sterilization adversely affect the quality of the therapy provided to the end-stage renal failure patient on peritoneal dialysis . Acid pH and glucose degradation products are thought to contribute to impaired host defense and hence to increased risk of infection, loss of ultrafiltration, and peritoneal fibrosis . On the other hand, peritoneal dialysis solutions prepared by aseptic processing are devoid of in vitro cytotoxicity and hence are considered more biocompatible than heat-sterilized solutions . With new technologies permitting aseptic processing to achieve sterility assurance levels approaching solutions manufactured by terminal heat sterilization, it is possible to produce solutions that are more biocompatible than heat-sterilized products without increasing the risk of microbial contamination.

J Periodontal Res, 1997 Jan, 32(1 Pt 1), 47 - 53
On the interpretation of microbial clusters in periodontal disease; Cohen ME; Cluster analysis is sometimes used in periodontal research to describe patterns of microbial identifications observed among cases (subjects or sites) . These patterns are assumed to define subsets of cases that are meaningful, in the sense of defining periodontal subgroups that have reliable differences in some aspect of their disease . However, cluster analysis is an exploratory, first-stage technique that does not incorporate the machinery that allows one to evaluate the statistical significance and reliability of the patterns observed . Problems inherent in drawing inferences from cluster analysis are discussed and, as one methodological example of how the statistical significance of clustering might be determined, a randomization-based test for binary scaled microbial identifications is described . The introduction of cluster analysis to the study of periodontal microbiology was important and innovative, but future work needs to incorporate validation by either statistical means or independent replication . The present rarity of such confirmatory methods in the literature suggests caution in accepting specific cluster-based hypotheses about patient-microbial patterns.

J Periodontal Res, 1997 Jan, 32(1 Pt 1), 1 - 8
Detection and possible biological role of chondroitinase and heparitinase enzymes produced by Porphyromonas gingivalis W50; Smith AJ et al.; Gingival crevicular fluid levels of the glycosaminoglycan (GAG) chondroitin-4-sulphate (C-4-S) have received increased attention as potential indicators of periodontal tissue turnover . However, little is known about the relationship between crevicular fluid connective tissue metabolites and microbial factors . In this study Porphyromonas gingivalis, a periodontopathogen, was investigated for its ability to degrade the GAGs C-4-S, dermatan sulphate (DS) and heparan sulphate (HS) in vitro . The effect of P . gingivalis extracts on the proteoglycans (PG) derived from human gingiva were also investigated . The presence of chondroitinase and heparitinase eliminase enzymes were identified from the vesicle fraction of P . gingivalis W50 . These enzymes were extracted from the vesicle fraction by a differential centrifugation technique and partially purified by non-denaturing gel filtration chromatography which revealed heparitinase enzyme peaks at 200 and 150 kDa and chondroitinase at 70 kDa . Gingival proteoglycans for use as substrates were purified using 4 M guanidinium chloride extraction and anion exchange chromatography; these proteoglycans contained 48% DS, 27% C-4-S and 13% HS P . gingivalis chondroitinase and heparitinase enzymes were capable of the degradation of C-4-S and HS but not DS GAGs . The presence of chondroitinase enzymes produced by P . gingivalis may influence levels of connective tissue metabolites in crevicular fluid . Furthermore these enzymes, particularly the heparitinase, may be involved in the initial permeation of the gingival epithelium, permitting the ingress of further microbial virulence factors.

J Clin Periodontol, 1997 Jan, 24(1), 72 - 7
The interleukin-1 genotype as a severity factor in adult periodontal disease; Kornman KS et al.; Although specific bacteria, dental plaque, and age are associated with periodontal disease, there are currently no reliable predictors of periodontitis severity . Studies in twins have suggested a genetic contribution to the pathogenesis of periodontitis, but previous attempts to identify genetic markers have been unsuccessful . The pro-inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) are key regulators of the host responses to microbial infection . IL-1 is also a major modulator of extracellular matrix catabolism and bone resorption . We report a specific genotype of the polymorphic IL-1 gene cluster that was associated with severity of periodontitis in non-smokers, and distinguished individuals with severe periodontitis from those with mild disease (odds ratio 18.9 for ages 40-60 years) . Functionally, the specific periodontitis-associated IL-1 genotype comprises a variant in the IL-1B gene that is associated with high levels of IL-1 production . In smokers severe disease was not correlated with genotype . In this study, 86.0% of the severe periodontitis patients were accounted for by either smoking or the IL-1 genotype . This study demonstrates that specific genetic markers, that have been associated with increased IL-1 production, are a strong indicator of susceptibility to severe periodontitis in adults.

Bioorg Med Chem, 1997 Jan, 5(1), 193 - 203
Screening of cell cycle inhibitors from microbial metabolites by a bioassay using a mouse cdc2 mutant cell line, tsFT210; Osada H et al.; We have established a bioassay system using a mouse cdc2 mutant cell line, tsFT210, to detect inhibitors of the mammalian cell cycle . When cultured at the high temperature, restrictive temperature at 39.4 degrees C, tsFT210 cells can be arrested at G2 phase and are large in size . Four hours after release from G2 arrest, the cells entered into the G1 phase . At this time, G1 phase cells were easily discriminated from the G2/M-cells by their size under microscopic observation . The cell-morphology-based bioassay utilizing tsFT210 cells is very simple and sensitive for detecting cdc2 kinase inhibitors and also G2/M-phase inhibitors of the mammalian cell cycle . To demonstrate the merits of this bioassay, the effects of protein kinase inhibitors isolated from actinomycetes were investigated . RK-286C and RK-1409, which are structurally related to staurosporine, inhibited cell cycle progression at the G2 phase in both G2-synchronized and nonsynchronized cultures of tsFT210 cells . Another kinase inhibitor, sangivamycin, inhibited cell cycle progression at the G2 phase of cells released from temperature arrest but did not inhibit that of the exponentially growing cells . Using the bioassay system, we carried out screening of the cell cycle inhibitors from the microbial metabolites and have discovered several new inhibitors, including novel compounds such as tryprostatins A, B and acetophthalidin . Thus, this bioassay allowed for the detection of cell cycle inhibitors and provided a convenient and useful method for the screening of new inhibitors from the microbial metabolites.

Biochem Mol Biol Int, 1997 Jan, 41(1), 11 - 23
The fungus Gibberella fujikuroi produces copper/topaquinone-containing amine oxidase when induced by N-butylamine; Frebort I et al.; Crude extract of Gibberella fujikuroi AKU 3802 mycelium induced with n-butylamine showed a single amine oxidase activity band in a non-denaturing gel that cross-reacted with the antibody against copper/topaquinone-containing amine oxidase from Aspergillus niger . The enzyme was purified by a procedure involving four chromatographic steps . Purified enzyme was pink with an absorption maximum at 490 nm . Molecular mass of 135 kDa estimated by gel chromatography and 70 kDa found by SDS-PAGE confirmed the dimeric structure of the enzyme . The enzyme readily oxidized n-hexylamine, n-butylamine, benzylamine and histamine, but not spermine or spermidine . Inactivation by carbonyl reagents and copper chelators suggested the presence of a copper/topaquinone cofactor . Spectrophotometric titration by p-nitrophenylhydrazine showed one reactive carbonyl group per subunit and redox-cyclic quinone staining confirmed the presence of a quinone cofactor . pH-dependent shift of the absorption spectrum of the enzyme p-nitrophenylhydrazone (465 nm at neutral to 580 nm at alkaline pH) supports the identity of the cofactor, with topaquinone . The N-terminal amino acid sequence of the enzyme showed high similarity to other microbial copper/topaquinone-containing amine oxidases.

J Dent Res, 1997 Jan, 76(1), 575 - 9
Short-chain carboxylic acid concentration in human gingival crevicular fluid; Niederman R et al.; Short-chain carboxylic acids (e.g., lactic acid, propionic acid, butyric acid) are metabolic by-products of bacterial metabolism which can accumulate in the gingival crevice . It is of no small consequence, therefore, that 1- to 5-mM concentrations of these acids exhibit significant biological activity, including the ability to alter cell proliferation and gene expression in cells of importance to the periodontium . This communication reports on the in vivo concentrations of propionic and butyric acid in the gingival crevices of periodontal subjects with severe and mild disease . The results indicated that severely diseased subjects exhibited a > 10-fold increase in the mM concentration of these acids when compared with mildly diseased subjects (mean propionic acid-severe = 9.5 +/- 1.8 mM, and mild = 0.8 +/- 0.3 mM; mean butyric acid-severe = 2.6 +/- 0.4 mM, and mild = 0.2 +/- 0.04 mM) . These differences (mean +/- SE) were significant (p < 0.0001) . The propionic and butyric acid concentrations were below detection limits in healthy sites of mildly diseased subjects . The propionic and butyric acid concentrations also associated significantly with clinical measures of disease severity (e.g., pocket depth, attachment level) and inflammation (e.g., subgingival temperature, % of sites bleeding when probed), and with the total microbial load (all p < 0.05) . Taken together, these data suggest that short-chain carboxylic acids play a mediating role in periodontal disease pathogenesis.

Biotechnol Prog, 1997 Jan-Feb, 13(1), 8 - 13
Dynamics of glucose consumption in yeast; Sonnleitner B et al.; When a continuously grown yeast culture was allowed to rest at the low dilution rate for an extended time period and was then challenged by increasing the dilution rate, applied as a step function, an overshoot of the concentration of residual glucose occurred reproducibly . A structural extension of the bottleneck model describing another intracellular bottleneck in glucose consumption allowed to predict such overshoots quantitatively . The model assumes that an intracellular enzymatic pool increases in response to a challenge by excess substrate supply, and experimentally, the relaxation time was determined to be on the order of 1 h . When the culture is reset to more limiting conditions, the enzymatic pool shrinks with a relaxation time determined by the reciprocal of the current specific growth rate . Generalized, microbial populations do memorize their (recent) history by adapting their metabolic outfit.

Poult Sci, 1997 Jan, 76(1), 59 - 66
Influence of dietary levels of fat, fiber, and copper sulfate and fat rancidity on cecal activity in the growing turkey; Leeson S et al.; Two experiments were conducted with 6- to 10-wk-old turkeys . In Experiment 1, 6-wk-old turkeys were fed diets varying in level of fat (4.4 to 10%) or fiber (2.5 to 9.0%) . The diets also contained extra copper as copper sulfate at either 0.1 or 0.2% of the diet . At 8 wk of age, 15 replicate birds were housed in individual cages and all excreta was collected . Excreta was separated as being "regular" or "cecal" in origin based on appearance . At 10 wk of age, 10 birds per treatment were killed and cecal contents removed under anaerobic conditions . Cecal contents were assayed for various nutrients and viscosity was measured . In a second comparable study, turkeys were fed animal-vegetable fat or regular or rancid canola oil (60.25 vs 120.24 ng/g malonaldehyde, respectively) . In Experiment 1, feeding copper sulfate had the most noticeable effect on various cecal parameters . There was an increase (P < 0.01) in dry matter cecal droppings produced and the cecal contents were of increased viscosity (P < 0.05) . Copper had no effect on pH or microbial colony count of the cecal contents . Feeding copper resulted in a significant increase in the high molecular weight (> 300,000) fraction of cecal contents and this fraction was of higher viscosity . Feeding copper sulfate resulted in a dramatic increase in copper content of cecal contents (280 to 11,848 ppm), although the copper content of regular excreta was also increased (17 to 1,008 ppm) . The various levels of fiber and fat generally had no effect on cecal parameters . Feeding rancid canola oil did result in increased viscosity of cecal contents, compared to the situation seen with fresh canola oil . Fat rancidity per se, however, failed to influence other parameters such as total mass of cecal material produced and composition of cecal material . Feeding copper sulfate or rancid fat will increase the viscosity of cecal material, which may contribute to litter management problems.

Poult Sci, 1997 Jan, 76(1), 37 - 46
Utilization of phytate phosphorus and calcium as influenced by microbial phytase, cholecalciferol, and the calcium: total phosphorus ratio in broiler diets; Qian H et al.; The present study was performed to evaluate the potential of microbial phytase and cholecalciferol (D3) for improving the utilization of phytate P and Ca and the influence of the Car:total (t) P ratio in a corn-soybean meal diet fed to broilers from hatch to 21 d of age . A 4 x 4 x 2 factorial arrangement of treatments was used: 1.1, 1.4, 1.7, and 2.0:1 Ca:tP ratio; 0, 300, 600, and 900 U of phytase/kg of diet; and 66 and 660 micrograms of D3/kg of diet . Another four treatments were included: the four Ca:tP ratios with 6,600 micrograms of D3 addition, but without phytase . Added phytase linearly increased (P < 0.001) BW gain, feed intake, toe ash content, and P and Ca retention; these measurements were negatively influenced by widening the dietary Ca:tP ratio, and synergetically improved by addition of D3 . Increasing the Ca:tP ratio decreased (P < 0.001) all measurements in the presence or absence of supplemental phytase and D3 . Dietary Ca:tP ratios between 1.1:1 to 1.4:1 appears critical to the efficient use of supplemental phytase and D3 for improving the utilization of phytate P and Ca . The addition of D3 in corn-soybean meal diets indicated a potential for improving the utilization of phytate P and Ca by increasing Ca and P retention by about 5 to 12% in birds, which led to an increase in toe ash content (P < 0.03) . The enhanced phytate P utilization (P < 0.001) was also observed during assay of the phytase activity in the mixed diets with an addition of D3 and without added phytase . In summary, the findings of this study suggested that phytase, D3, and Ca:tP are important factors in degrading phytate and improving phytate P and Ca utilization in broilers.

Immunol Invest, 1997 Jan-Feb, 26(1-2), 275 - 81
Superantigens: their role in infectious diseases; Stevens DL; In the last 10 years many of the superantigens of the microbial world have been defined and the mechanisms of cellular interaction between lymphocytes and antigen presenting cells has been elucidated in great detail . The consequences of superantigen stimulation of the immune system, though less well defined, can be considered in three separate stages: T-cell proliferation, apoptosis, and recovery . Understanding these stages may explain why diverse superantigens may cause markedly different clinical processes ranging from acute shock to chronic arthritis and may form the basis for novel treatments of these diverse diseases.

Plant Mol Biol, 1997 Jan, 33(2), 257 - 66
The promoter of the tobacco Tnt1 retrotransposon is induced by wounding and by abiotic stress; Mhiri C et al.; The transcription of the tobacco Tnt1 retrotransposon was previously shown to be induced, in tobacco and in heterologous species, by microbial elicitors and by pathogen infections . We report here that the expression of the Tnt1 promoter is also activated in heterologous species such as tomato and Arabidopsis by wounding, freezing and by other abiotic factors known to induce the plant defence response, such as salicylic acid, CuCl2, or oxidative stress . A similar regulation is observed in tobacco for most treatments . The induction of the Tnt1 promoter expression by wounding remains localized around injury points . In CuCl2-treated Arabidopsis plants, the transcription of Tnt1 is correlated with accumulation of the phytoalexin camalexin and with the expression of the EL13 defence gene . The interest of the Tnt1 promoter as a sensitive indicator of the plant defence responses is discussed.

J Periodontol, 1997 Jan, 68(1), 67 - 72
A correlation study of inflammatory cell mobilization in response to subgingival microbial colonization; Leknes KN et al.; This study evaluated site-by-site the relations between subgingival microbial colonization and gingival tissue reactions . Experimental, deep periodontal defects were established at buccal surfaces of mandibular and maxillary canine teeth in 5 beagle dogs . The root surfaces were instrumented by a flame-shaped, fine-grained, rotating diamond point, or by a sharp curet . Following a 10-day postsurgical healing period, the dogs were fed a plaque-inducing diet for 70 days . The animals were then sacrificed and tissue blocks of the experimental sites including teeth and periodontal tissues were secured . The buccal gingiva was removed and processed for histomorphometric analysis while the teeth were prepared for scanning electron microscopic evaluation of the extent of subgingival microbial colonization . The results revealed that inflammatory cell density in the junctional epithelium and in the connective tissue were positively correlated to subgingival microbial colonization (P < 0.01) . Furthermore, the degree of significance decreased with increasing distance from the plaque . The present study demonstrates that a close relation may exist between the extent of subgingival microbial colonization and inflammatory gingival tissue reactions.

Int J Food Microbiol, 1997 Jan, 34(1), 89 - 94
The effect of previous growth conditions on the lag phase time of some foodborne pathogenic micro-organisms; Dufrenne J et al.; In current models for predicting microbial growth, the lag phase duration is expressed as a function of the growth rate of the micro-organism . We observed that in addition to the growth rate (as influenced by incubation temperature and NaCl contents), the pre-incubation temperature influences the lag phase duration of foodborne pathogenic micro-organisms.

J Invertebr Pathol, 1997 Jan, 69(1), 46 - 50
Effects of diet-age and streptomycin on virulence of Autographa californica M nucleopolyhedrovirus against the tobacco budworm; Hoover K et al.; Addition of the antibiotic streptomycin to two artificial diets routinely used in bioassays of neonate lar vae of Heliothis virescens (tobacco budworm) infected with Autographa californica M nucleopolyhedrovirus (AcMNPV) increased lethal times of the virus . After storage of diets for 3 weeks at 4 degrees C, lethal times of infected larvae were significantly slower compared to those for larvae bioassayed using diets stored for 2 weeks or less . The effect of diet-age on rate of mortality was not the result of a change in total protein content or pH of the diet, but was apparently the result of some other alteration in the quality of the diet (e.g . microbial spoilage, palatibility, and/or nutritional value unrelated to total protein) . Although we did not determine why lethal times were slower in response to streptomycin concentration or diet-age, we did find that slower lethal times were correlated with slower relative growth rates (RGR) of infected larvae . In addition, RGR of infected larvae decreased as a function of increasing streptomycin concentration, diet-age, and the interaction of the two factors . These results demonstrate that it is difficult to obtain consistent and comparable bioassay results if antibiotic composition and diet-age are not controlled . We suggest a standardized diet or highly standardized procedures for a given diet be developed that permits comparison of bioassays among and within laboratories.

Nephrol Dial Transplant, 1997 Jan, 12(1), 157 - 60
One-dose cefuroxime i.v . and i.p . reduces microbial growth in PD patients after catheter insertion; Wikdahl AM et al.; BACKGROUND: When a peritoneal dialysis catheter is inserted intra-abdominally in a patient starting peritoneal dialysis (PD) there is always a risk for postoperative wound infection and peritonitis . At our centre, PD is started immediately after the dialysis catheter is inserted . This may increase the postoperative risk for peritonitis and wound infection . The aim of this prospective, randomized, study was to evaluate whether the incidence of microbial growth postoperatively (within 10 days) after catheter insertion could be reduced by prophylactic antibiotic therapy . SUBJECTS AND METHODS: During a period of 27 months, 38 patients, who consecutively entered the PD programme, (11 women and 27 men, mean age 57 years) were included in the study . Eighteen patients were given cefuroxime 1.5 g i.v . preoperatively and 250 mg i.p . in the first dialysis bag (containing 1 litre fluid) as prophylaxis . Twenty patients were not given prophylactic antibiotics (control group) . All catheter insertions were performed in an operating theatre by the same surgeons using the same technique . RESULTS: In the test group, none of the patients showed microbial growth in the dialysis fluid during the post-operative period, while in the control group six of 20 patients (30%) suffered from such growth (P = 0.021) . CONCLUSION: Prophylactic treatment by cefuroxime i.v . pre- and i.p . perioperatively may reduce the risk for microbial growth and peritonitis after insertion of a Tenckhoff catheter.

Anal Biochem, 1997 Jan 1, 244(1), 55 - 61
Detection and characterization of phospholipase D by flow injection analysis; Becker M et al.; A precisely working automated system for the investigation of phospholipases D (PLDs, EC 3.1.4.4) from plant and microbial sources with flow injection analysis (FIA) has been developed . The two versions of the FIA setup described are based on the oxidation of choline liberated from phosphatidylcholine by PLD action and catalyzed by choline oxidase and the chemiluminescence detection of hydrogen peroxide produced by this reaction . The correlation between this chemiluminescence signal and the PLD activity was linear in the range between 1 and 100 mU/ml PLD . The sampling frequency was 12 samples per hour . This method was used to compare three different PLDs from cabbage and microbial sources with respect to their pH optima, temperature stability, effectors, and v/{S}-characteristics.

Am J Obstet Gynecol, 1997 Jan, 176(1 Pt 1), 173 - 8
Vaginal flora changes associated with Mycoplasma hominis; Mardh PA et al.; OBJECTIVE: The aim of this study was to investigate any association between vaginal carriage of Mycoplasma hominis and genital signs and symptoms, other microbial findings, and some risk behavior factors in women with and without bacterial vaginosis . STUDY DESIGN: Women who had attended two family planning clinics and a youth clinic for contraceptive advice were divided depending on the result of vaginal culture for Mycoplasma hominis and the occurrence of bacterial vaginosis . The study population included 123 (12.3%) women who harbored Mycoplasma hominis . Those 873 (87.7%) with a negative culture for Mycoplasma hominis served as a comparison group . In the former group, 50 (40.7%) had bacterial vaginosis, which was also the case in 81 (9.3%) of the women in the comparison group . The groups were compared with regard to genital signs and symptoms, results of vaginal wet smear microscopy and other office tests, vaginal flora changes as detected by culture, and other means and detection of sexually transmitted diseases . Any history of sexually transmitted diseases and other genital infections, reproductive history, use of oral contraceptives, and smoking habits were registered . RESULTS: Women who harbored Mycoplasma hominis had significantly more often complained of a fishy odor, had a positive amine test, a vaginal pH > 4.7, and clue cells than did the comparison group; all these statements were true before and after bacterial vaginosis had been excluded . Vaginal discharge was not significantly more often complained of, and a pathologic discharge was not more often detected in the Mycoplasma hominis carriers . Ureaplasma urealyticum occurred in 75% of the Mycoplasma hominis-positive women and in 59% of the comparison group (p = 0.001) . The leukocyte/epithelial cell ratio did not differ significantly from that of the Mycoplasma hominis culture-negative controls . CONCLUSION: The study suggests that Mycoplasma hominis is associated with a number of genital signs and symptoms even after exclusion of bacterial vaginosis.

Scand J Immunol, 1997 Jan, 45(1), 36 - 42
An endogenous superantigen in the rat gut lumen as a model to study the role of human protein-Fv; Guihard AI et al.; Protein-Fv (pFv) is a human B superantigen which can bind the variable domain (VH) of the heavy chain of immunoglobulins (Igs) and enhance the effector functions of secretory antibodies in the gut lumen . This study describes a rat molecule related to pFv by a similar specificity to the human VH3 domain . Investigation of the content of different gut segments shows that the rat pFv is usually hidden by its binding to local Igs to form macromolecular complexes similar to the immune fortresses described in normal humans . Furthermore, the pFv level generally increases from the jejunum to the colon in parallel with the decreasing water dilution, and finally a discontinuous presence can occur along the digestive tract . Detection of this molecule in the fetus proves its non-microbial origin . Variations of the release of pFv, according to the breeding and to littermating, suggest the influence of external factors . This animal model allows the development of a study of the functions of pFv in vivo using a current laboratory species and has already provided evidence that the synthesis of this important molecule of the secretory immune system is regulated by environmental factors.

Anat Embryol (Berl), 1997 Jan, 195(1), 41 - 50
Jejunal and ileal Peyer's patches in pigs differ in their postnatal development; Barman NN et al.; The postnatal development of the jejunal and ileal Peyer's patches was studied before and after weaning in 1-, 1.5- and 2-month-old pigs . The follicles of the jejunal Peyer's patches grew with age and were two times longer and wider in specified pathogen-free and conventional pigs than in germ-free animals, thus indicating an influence of the living microbial antigens from the gut lumen . In germ-free pigs the size of the ileal Peyer's patch follicles increased between the 1st and 2nd month, whereas in the specified pathogen-free and conventional animals these follicles were comparable in size in all three age groups . In 1- to 1.5-month-old pigs the interfollicular area of jejunal Peyer's patches was wider (0.1 +/- 0.04 mm) than that of the ileal Peyer's patch (0.04 +/- 0.03 mm) . Immunohistological studies showed that in germ-free pigs preferentially surface IgM+ but few IgA+ B cells were present in the follicles, domes and dome epithelia . In specified pathogen-free and conventional pigs the B cells expressed different levels of surface or cytoplasmic IgM or IgA . In all groups studied, more T cells were observed in the jejunal than in the ileal Peyer's patch . Here, few T lymphocytes were found because of the small interfollicular areas . Small numbers of Null cells were distributed in the interfollicular regions of all animals . The results show that living microbial antigens have a major influence on the jejunal and ileal Peyer's patches in pigs . The morphological differences between the two types of Peyer's patches are an indication that they develop differently during postnatal life . So far it remains unclear whether these morphological differences reflect a specific function of the pig's ileal Peyer's patch, such as the expansion of the genetically determined B cell repertoire as has been reported for sheep.

FEMS Microbiol Lett, 1997 Jan 1, 146(1), 13 - 22
Microbial ribulose 1,5-bisphosphate carboxylase/oxygenase: a molecule for phylogenetic and enzymological investigation; Watson GM et al.; Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) catalyzes the key reaction of the Calvin reductive pentose phosphate cycle and as such is responsible for life as we know it . This enzyme has been intensively studied for decades . Evidence that RubisCO phylogenies are incongruent with those derived from other macromolecules has been accumulating and recent discoveries have driven home this point . Here we review findings regarding RubisCO phylogeny and discuss these in the context of the important biochemical and structural features of the enzyme . The implications for the engineering of improved RubisCO enzymes are considered.

Appl Environ Microbiol, 1997 Jan, 63(1), 63 - 70
Diversity and depth-specific distribution of SAR11 cluster rRNA genes from marine planktonic bacteria; Field KG et al.; Small-subunit (SSU) ribosomal DNA (rDNA) gene clusters are phylogenetically related sets of SSU rRNA genes, commonly encountered in genes amplified from natural populations . Genetic variability in gene clusters could result from artifacts (polymerase error or PCR chimera formation), microevolution (variation among rrn copies within strains), or macroevolution (genetic divergence correlated with long-term evolutionary divergence) . To better understand gene clusters this study assessed genetic diversity and distribution of a single environmental SSU rDNA gene cluster, the SAR11 cluster . SAR11 cluster genes, from an uncultured group of the alpha subclass of the class Proteobacteria, have been recovered from coastal and midoceanic waters of the North Atlantic and Pacific . We cloned and bidirectionally sequenced 23 new SAR11 cluster 16S rRNA genes, from 80 and 250 m in the Sargasso Sea and from surface coastal waters of the Atlantic and Pacific, and analyzed them with previously published sequences . Two SAR11 genes were obviously PCR chimeras, but the biological (nonchimeric) origins of most subgroups within the cluster were confirmed by independent recovery from separate gene libraries . Using group-specific oligonucleotide probes, we analyzed depth profiles of nucleic acids, targeting both amplified rDNAs and bulk RNAs . Two subgroups within the SAR11 cluster showed different highly depth-specific distributions . We conclude that some of the genetic diversity within the SAR11 gene cluster represents macroevolutionary divergence correlated with niche specialization . Furthermore, we demonstrate the utility for marine microbial ecology of oligonucleotide probes based on gene sequences amplified from natural populations and show that a detailed knowledge of sequence variability may be needed to effectively design these probes.

Infect Immun, 1997 Jan, 65(1), 293 - 7
Identification of CD14 residues involved in specific lipopolysaccharide recognition; Shapiro RA et al.; CD14 is a key molecule responsible for the innate host inflammatory response to microbial infection . It is able to bind a wide variety of microbial ligands and facilitate the activation of both myeloid and nonmyeloid cells . However, its specific contribution to the innate recognition of bacteria is not known . Presently there is no information on the contribution of individual CD14 residues to Escherichia coli lipopolysaccharide (LPS) binding or on the molecular basis of the interaction between CD14 and LPS from other bacteria . LPS obtained from Porphyromonas gingivalis, a bacterium associated with chronic inflammatory disease, binds CD14 and activates myeloid cells but does not facilitate the activation of nonmyeloid cells . The transfer and binding of these two LPS species to soluble CD14 recombinant globulin proteins with single point mutations was examined . Functional activity of the mutant proteins was monitored by E-selectin expression on human umbilical cord endothelial cells . The analysis identified a charge reversal mutation in a single residue, E47, that demonstrated selective binding to E . coli LPS but not to P . gingivalis LPS . E-selectin activation assays indicated that proteins with mutations at position E47 maintained their structural integrity . Other mutations, including a charge reversal mutation of residue E58, did not significantly reduce the binding of either LPS ligand or the ability of the molecule to facilitate E-selectin activation . These data demonstrate that CD14 can selectively recognize different LPS ligands.

Adv Biochem Eng Biotechnol, 1997, 56, 33 - 59
Biotransformation for L-ephedrine production; Rogers PL et al.; L-ephedrine is widely used in pharmaceutical preparations as a decongestant and anti-asthmatic compound . One of the key intermediates in its production is L-phenylacetylcarbinol (L-PAC) which can be obtained either from plants (Ephedra sp.), chemical synthesis involving resolution of a racemic mixture, or by biotransformation of benzaldehyde using various yeasts . In the present review, recent significant improvements in the microbial biotransformation are assessed for both fed-batch and continuous processes using free and immobilised yeasts . From previous fed-batch culture data, maximal levels of L-PAC of 10-12 gl-1 were reported with yields of 55-60% theoretical based on benzaldehyde . However, recently concentrations of more than 22 gl-1 have been obtained using a wild-type strain of Candida utilis . This has been achieved through optimal control of yeast metabolism (via microprocessor control of the respiratory quotient, RQ) in order to enhance substrate pyruvate production and induce pyruvate decarboxylase (PDC) activity . Processes involving purified PDC have also been evaluated and it has been demonstrated that L-PAC levels up to 28 gl-1 can be obtained with yields of 90-95% theoretical based on the benzaldehyde added . In the review the advantages and disadvantages of the various strategies for the microbial and enzymatic production of L-PAC are compared . In view of the increasing interest in microbial biotransformations, L-PAC production provides an interesting example of enhancement through on-line control of a process involving both toxic substrate (benzaldehyde) and end-product (L-PAC, benzyl alcohol) inhibition.

Toxicology, 1996 Dec 18, 114(3), 243 - 52
Effects of ozone upon macrophage-interferon interactions; Cohen MD et al.; Lung cell populations may be directly exposed to environmental airbone toxicants such as ozone (O3) . Since pulmonary macrophages (M phi) play a pivotal role in host pulmonary immunocompetence, their function in this regard may be compromised by pollutant exposure thereby giving rise to an increased incidence of pulmonary disease . The current in vitro study was designed to provide some insight into possible mechanisms by which O3 induces decreased host pulmonary resistance against microbial pathogens . Specifically, this study investigated the impact of an acute O3 exposure upon the ability of a cultured mouse M phi cell line (WEHI-3) to interact with, and respond to, the major M phi-activating cytokine, interferon-gamma (IFN gamma) . The results of this study indicate that WEHI-3 exposure to 1 ppm O3 for 4 h reduced both the binding of, and responsivity to, IFN gamma . Among the functional parameters affected by this inability to properly bind/respond to IFN gamma were: reactive oxygen intermediate production, phagocytic activity, and cellular calcium ion elevation; IFN gamma-enhanced expression of surface histocompatibility antigens was unaffected by O3 exposure . The reduced activity of any one of these critical M phi functions could provide a basis for previously-documented increases in microbial pathogen survival in the lungs, and overall compromise of host health following O3 exposure.

J Immunol, 1996 Dec 15, 157(12), 5521 - 7
Induction of gammadelta T cells during acute murine infection with Toxoplasma gondii; Kasper LH et al.; The importance of the host gammadelta T cell response to microbial pathogens is not yet fully understood . We report that inbred mice infected with T . gondii developed a gammadelta T cell proliferative response to parasite Ag . Mice depleted of either the alphabeta or gammadelta TCR were found to be significantly more susceptible to infection than the parent mouse strain . Proliferation of gammadelta T cells was observed in mice deficient in the TCR-alphabeta in response to UV-irradiated parasites . These T cells lyse parasite-infected syngenic macrophages . Adoptive transfer of these gammadelta T cells into beta2 microglobulin-deficient mice that have been depleted of both CD4+ and NK cells prolongs survival against acute parasite challenge when compared with nontransferred controls . The gammadelta T cells isolated from infected alpha -/- mice express a 10-fold increase in mRNA and produce high titers of IFN-gamma . These data suggest that gammadelta T cells may play an important role in the early host response to infection with T . gondii.

J Immunol, 1996 Dec 15, 157(12), 5394 - 402
Rapid immune activation by CpG motifs in bacterial DNA . Systemic induction of IL-6 transcription through an antioxidant-sensitive pathway; Yi AK et al.; Unmethylated CpG dinucleotides (CpG motif) in bacterial DNA or synthetic oligodeoxynucleotides (CpG DNA) rapidly activate murine B cells to secrete IL-6 and IgM, as well as to proliferate . Within 30 min after CpG DNA stimulation in vivo, IL-6 mRNA levels were increased in liver, spleen, and thymus cells . Serum IL-6 protein was markedly increased within 1 h of stimulation . Treatment of a B cell line with CpG DNA led to an increase in the transcriptional activity of the IL-6 promoter . This CpG DNA-induced IL-6 production was not mediated via either a protein kinase C (PKC)-, protein kinase A (PKA)-, or nitric oxide (NO.)-dependent pathway but was inhibited by an antioxidant . In addition, the level of intracellular reactive oxygen species was increased within 20 min after CpG DNA, but not control non-CpG DNA, treatment . These results suggest that CpG DNA-induced IL-6 production is mediated through a reactive oxygen intermediate-dependent pathway . CpG DNA-mediated IL-6 production was enhanced by simultaneous signals delivered through the Ag receptor . The addition of neutralizing Abs against IL-6 to B cell cultures along with CpG oligodeoxynucleotides essentially abolished the CpG DNA-induced increased IgM secretion but had no significant effect on the B cell proliferation induced by the CpG motif . Our results suggest that the induction of IL-6 expression in response to CpG motifs in bacterial DNA may be an important immune defense mechanism that facilitates a rapid response to microbial infection.

Biochim Biophys Acta, 1996 Dec 13, 1304(3), 229 - 44
Inhibition of microbial lipases with stereoisomeric triradylglycerol analog phosphonates; Stadler P et al.; 1,2(2,3)-Diradylglycero O-(p-nitrophenyl) n-hexylphosphonates were synthesized, with the diradylglycerol moiety being di-O-octylglycerol, 1-O-hexadecyl-2-O-pyrenedecanylglycerol, or 1-O-octyl-2-oleoyl-glycerol, and tested for their ability to inactivate lipases from Chromobacterium viscosum (CVL) and Rhizopus oryzae (ROL) . The experimental data indicate the formation of stable, covalent 1:1 enzyme-inhibitor adducts with the di-O-alkylglycero phosphonates . The differences in reactivity of diastereomeric phosphonates with opposite configuration at the glycerol backbone was less expressed with both enzymes tested as compared to the influence of the stereochemistry at the phosphorus . Both lipases exhibited the same preference for the chirality at the phosphorus that was independent from the absolute configuration at the glycerol backbone . However, with CVL and ROL the inhibitors with the active site serine-directed phosphonate linked at position sn-1 of the glycerol moiety reacted significantly faster than the corresponding sn-3 analogs, reflecting the sn-1 stereopreference of the enzymes towards triacylglycerol analogs with a sn-2 O-alkyl substituent . In contrast, the phosphonates based on the 1-O-octyl-2-oleoylglycerol did not significantly inactivate CVL . Unexpectedly, these substances were hydrolyzed in the presence of lipase.

Biochim Biophys Acta, 1996 Dec 12, 1314(3), 239 - 46
Modulation of degranulation and superoxide generation in human neutrophils by unsaturated fatty acids of odd carbon numbers; Ishida-Okawara A et al.; Unsaturated fatty acids of odd carbons, 13:1(12), 17:1(10trans), 19:1(7) and 19:1(10) inhibited release of myeloperoxidase (MPO) from fMet-Leu-Phe-cytochalasin B-treated neutrophils . The inhibitory effect was smaller than that of aseanostatins which have been isolated as microbial-derived free fatty acids with a methyl blanch (i-14:0 and ai-15:0) (Journal of Antibiotics (1991) 44, 524-532) . These unsaturated fatty acids also inhibited lactoferrin release by the same treatment . On the other hand, 13:1(12), 15:1(10) and 19:1(10) inhibited fMet-Leu-Phe-stimulated superoxide generation of neutrophils, and the fatty acids 15:1(10), 17:(10) and 19:2(10,13) induced superoxide generation in both unstimulated cells and the cell-free system . However, none of unsaturated fatty acids of odd carbons tested inhibited beta-glucuronidase release, whereas 15:1(10), 17:1(10), 19:1(10) and 19:2(10,13) rather enhanced an increase in beta-glucuronidase activity liberated from cells at high concentrations over 35 microM, indicating cellular damages by these fatty acids . These observations suggest that unsaturated free fatty acids having odd carbons such as 13, 15, 17 and 19 may act as modulators of neutrophil functions including degranulation and superoxide generation.

Clin Oral Implants Res, 1996 Dec, 7(4), 405 - 9
The influence of periodontitis on the subgingival flora around implants in partially edentulous patients; Papaioannou W et al.; The hypothesis that teeth act as reservoirs of micro-organisms for the colonization of oral implants has recently been stated several times . The present study aimed at examining, in partially edentulous patients with severe periodontitis, whether pockets around teeth and implants harbored a comparable micro-flora . In 6 patients (3 with refractory periodontitis and 3 with advanced chronic adult periodontitis), plaque samples were taken from a deep and shallow pocket around both teeth and implants for differential phase contrast microscopy and DNA probe analysis . The results showed important differences in the sub-gingival flora between the 2 disease groups, as well as between deep and shallow pockets, around both implants and teeth . On the other hand, when pockets around teeth and implants with equal depths were compared a striking similarity was observed in the microbial composition . These observations confirm the hypothesis that pockets around teeth act as a reservoir and highlight the importance of periodontal health when oral implants are planned.

Arch Latinoam Nutr, 1996 Dec, 44(4 Suppl 1), 21S - 25S
Interaction of proteases with legume seed inhibitors . Molecular features; de Seidl DS; After having found that raw black beans (Phaseolus vulgaris) were toxic, while the cooked ones constitute the basic diet of the underdeveloped peoples of the world, in the sixties, our research directed by Dr . Jaffe, concentrated mainly around the detection and identification of the heat labile toxic factors in legume seeds . A micromethod for the detection of protease inhibitors (PI) in individual seeds was developed, for the purpose of establishing that the multiple trypsin inhibitors (TI) found in the Cubagua variety were expressions of single seeds and not a mixture of a non homogenous bean lot . Six isoinhibitors were isolated and purified, all of which were "double-headed" and interacted with trypsin (T) and chymotrypsin (CHT) independently and simultaneously, as shown by electrophoresis of their binary and ternary complexes with each and both enzymes . However, their affinity for the enzymes, including elastases, was rather variable, as well as their amino acid composition which consisted of 51 units for inhibitor V, the smallest, and 83 amino acids for inhibitor I, the largest . A low molecular weight protein fraction that inhibited subtilisin (S), but recognized neither T, CHT nor pancreatic elastase was detected in 63 varieties of Phaseolus vulgaris as well as in broad beans (Vicia faba), chick peas (Cicer arietinum), jack beans (Canavalia ensiformis), kidney beans (Vigna aureus), etc., It was absent though, in soybeans (Glycine max), lentils (Lens culinaris), green peas (Pisum sativum), cowpea (Vigna sinensis) and lupine seeds (Lupinus sp) . Subtilisin inhibitors (SI) were isolated from black beans, broad beans, chick peas and jack beans . Their Mr is between 8-9KD and they show a rather high stability in the presence of denaturing agents . They are specific toward microbial proteases, in addition to subtilisins, Carlsberg and BPN', they inhibit the alkaline protease from Tritirachium album (Protease K), from Aspergillus oryzae and one isolated from Streptomyces griseus, but do not interact with either animal digestive or plant thiol enzymes.

Nippon Geka Gakkai Zasshi, 1996 Dec, 97(12), 1054 - 9
{Cytokine-mediated biological response to severe infections in surgical patients}; Aikawa N et al.; Cytokines serve to initiate the acute inflammatory response and to integrate nonspecific and specific immunological responses to infections occurring in perioperative patients . Microbial substances induce macrophages to produce pivotal cytokines (TNF-alpha and IL-1 beta) . This results in an activation of other cytokine productions including IL-2, IL-3, IL-4, IL-6, chemokines, and IL-10 . Also, other host-originated humoral mediators are released from macrophages, neutrophils, platelets, and endothelial cells Various cytokines are also produced by helper-T (Th) cells, and the Th1/Th2 balance is regulated by cytokines and stress hormones . This nonspecific inflammatory response and specific immunological response which are mediated by cytokines are crucial for the host defense against invading pathogens . On the other hand, the blood levels of TNF-alpha, IL-6, IL-8, and MIP-1 alpha were correlated with the severity and mortality in patients with sepsis . Also we found that in patients with inhalation injury the high IL-8 levels in bronchoalveolar lavage fluid on admission predicted the development of respiratory insufficiency . In severe infection, a systemic release of various cytokines is not properly regulated, and the high blood levels of the proinflammatory cytokines cause an autodestructive systemic inflammatory response syndrome (SIRS) . This condition is termed "Cytokine Storm" by the author . In cytokine storm, not only proinflamamtory cytokines, but also anti-inflammatory cytokines appear in circulating blood, leading to septic shock, multiple organ dysfunction, and immunosuppression . With further understanding of the roles of cytokines in sepsis, modulation of cytokine responses could be a new modality of the treatment.

J Dairy Sci, 1996 Dec, 79(12), 2247 - 54
Influence of niacin supplementation on in vivo digestibility and ruminal digestion in dairy cows; Doreau M et al.; The effect of niacin supplementation on digestion was investigated using four cows in a crossover design . After peak lactation, cows received a diet of corn silage (55%) and concentrates (45%), including a formaldehyde-treated mixture of soybean meal, rapeseed meal, and urea . This diet was either supplemented with niacin (6 g/d) or not supplemented . Total tract apparent digestibility of OM and fiber and ruminal digestibility of OM were not modified by treatment . Niacin supplementation enhanced the theoretical degradability of ruminal DM in situ (44.7% vs . 40.6%) and concentration of protozoa in ruminal fluid (459 vs . 311 x 10(3)/ml), especially Ophryoscolecidae . The percentage of butyrate in the VFA mixture of ruminal fluid was increased by niacin supply, but acetate and propionate percentages and total VFA concentration did not vary . Ruminal digesta, ruminal pools, and ruminal kinetics were not affected by treatment . Duodenal flow of nonmicrobial N tended to increase with niacin supplementation . Duodenal flow of microbial N did not vary, as measured using a microbial sample, for fluid-associated bacteria or for a mixture of fluid-associated and particle-associated bacteria . These results are discussed in relation to the characteristics of the diet.

Immunology, 1996 Dec, 89(4), 494 - 501
Microbial colonization influences composition and T-cell receptor V beta repertoire of intraepithelial lymphocytes in rat intestine; Helgeland L et al.; Studies in mice have shown that the composition of intestinal intraepithelial lymphocytes (IEL) may be markedly altered by gut microbial colonization . Such modulation was studied in a rat model by the use of germ-free and conventionalized animals from which IEL from the small intestine were isolated and analysed by flow cytometry . Conventionalization caused expansion as well as phenotypic alterations of T-cell receptor (TCR) alpha/beta + IEL in that the proportions of CD4+ and CD8 alpha beta + TCR alpha/beta + cells were increased, while the double negative (CD4- CD8-) fraction was reduced . microbial colonization also influenced the TCR V beta repertoire of CD8+ IEL in that the proportions of V beta 8.2+ and V beta 10+ cells were increased, whereas V beta 8.5+ and V beta 16+ cells were relatively decreased . Moreover, conventionalization influenced the levels of TCR cell surface expression in the same V beta subsets . Three-colour flow-cytometric analysis demonstrated that skewing of the V beta repertoire was most pronounced in the CD8 alpha alpha + subset, although the numerical increase of IEL mainly included the CD8 alpha beta + subset . In contrast to IEL, the TCR V beta repertoire in mesenteric lymph nodes was unchanged after intestinal colonization . These results confirm that TCR alpha/beta + IEL subpopulations respond dynamically to the microbial gut flora and suggest that their V beta repertoire can be shaped by luminal microbial antigens.

Rev Rhum Engl Ed, 1996 Dec, 63(11), 815 - 22
Spondylarthropathic diseases in indigenous circumpolar populations of Russia and Alaska; Benevolenskaya LI et al.; AIMS: To compare the nature and frequency of spondylarthropathy in geographically separated but genetically related populations with a high prevalence of HLA-B27 . METHODS: Using a common questionnaire and disease criteria, cases were ascertained through cross-sectional community surveys in Russia and by examination and study of possible cases identified through rheumatic disease registries and the Native Health Service's computerized patient care data system in Alaska . RESULTS: Similar overall prevalences of spondyloarthropathy (2.0-3.4%) and a similar spectrum of disease were found, including reactive arthritis, ankylosing spondylitis and undifferentiated spondylarthropathy . Psoriatic arthritis was very rare . CONCLUSION: No predisposition to one particular form of spondyloarthropathy was observed; genetic and microbial settings for a spectrum of disease were present . Among adults positive for the presence of HLA-B27 the prevalence of all types of spondylarthropathies was estimated to be 4.5%, all populations combined, and the prevalence of AS was estimated to be 1.6%.

J Pharm Pharmacol, 1996 Dec, 48(12), 1237 - 42
Preservative efficacy tests in formulated nasal products: reproducibility and factors affecting preservative activity; Hodges NA et al.; Preservative efficacy tests were performed in triplicate on each of three batches of three formulated nasal spray preparations to assess the inter- and intra-batch variation in preservative performance which typically results from these procedures, and to assess the relative importance of factors influencing preservative performance in nasal products . Tests were conducted using procedures conforming, as far as possible, to both the European and the US pharmacopoeias and the results interpreted using the performance criteria of both . Despite the adoption of practices designed to maximize reproducibility, a marked variation in the degree of microbial inactivation was observed, both within and between batches of product . A preservative system comprising benzalkonium chloride and phenylethyl alcohol was found to be far superior to combinations of either benzalkonium chloride plus disodium edetate or potassium sorbate plus disodium edetate, both of which failed to satisfy the EP performance criteria on a number of occasions . Proposals are made for the adoption of inactivation criteria which incorporate realistic error limits reflecting the inherent problems of reproducibility of the viable counting procedures involved.

Poult Sci, 1996 Dec, 75(12), 1516 - 23
Efficacy of supplemental microbial phytase at different dietary calcium levels on growth performance and mineral utilization of broiler chickens; Sebastian S et al.; A 3-wk feeding trial with 240 sexed, day-old broiler chickens was conducted to determine the efficacy of microbial phytase at different levels of dietary Ca on performance and utilization of minerals in broiler chickens fed a low-P corn-soybean diet . The experimental design was a 3 x 2 factorial arrangement of treatments; Ca at 0.6, 1.0, and 1.25% and phytase at 0 and 600 phytase U/kg diet . Phytase supplementation, regardless of Ca level, increased (P < or = 0.005) feed intake, (P < or = 0.0001) body weight, and (P < or = 0.025) feed efficiency at 21 d; the optimum levels of body weight, feed intake, and feed efficiency were obtained with low (0.6%) dietary Ca plus phytase . Retentions of P, Ca, and N were increased (P < or = 0.05) by phytase supplementation . Although maximum retentions of P and N were obtained at the 1.0 and 1.25% Ca levels, respectively, they were not significantly different from the values obtained at 0.6% Ca . The increasing level of dietary Ca decreased plasma P ( P < or = 0.05) and Cu (P < or = 0.06) . Phytase supplementation had the opposite effect; i.e., increased plasma P (P < or = 0.03) and Cu (P < or = 0.02) . The maximum level of plasma P was obtained with phytase at the 1.0% Ca level, but this value was not significantly different from the value obtained with phytase at the 0.6% Ca level . Phytase supplementation increased (P < 0.04) the ash content of both tibia head and shaft but had no effect on mineral contents in the ash . The optimum level of ash content was observed with the 0.06% Ca diet plus phytase . The results show that microbial phytase supplementation to a low P diet improved growth performance and mineral utilization in broiler chickens . Dietary Ca levels had a significant effect on the response to phytase; the optimum growth performance and mineral utilization were achieved at the low (0.6%) level of dietary Ca supplemented with phytase.

J Anim Sci, 1996 Dec, 74(12), 2960 - 6
Efficacy of supplemental 1 alpha-hydroxycholecalciferol and microbial phytase for young pigs fed phosphorus- or amino acid-deficient corn-soybean meal diets; Biehl RR et al.; Young pigs (5 wk of age and 8 kg) were used to test the efficacy of 1 alpha-hydroxycholecalciferol (1 alpha-OH D3) and microbial phytase for improving the utilization of phytate phosphorus (P) and amino acids present in corn-soybean meal (SBM) diets . Phytase supplementation (1,200 units/kg) to a vitamin D3-adequate, P-deficient corn-SBM diet elicited a marked response (P < .05) in weight gain and ash content of fibula, scapula, and metatarsal bones, but dietary addition of 1 alpha-OH D3 (20 micrograms/kg) was without effect . A P- and vitamin D3-adequate, amino acid-deficient corn-SBM diet (15.5% CP) also was supplemented with 1,200 units/kg of phytase to evaluate the efficacy of phytase in improving amino acid utilization . Pigs gained faster (P < .05) and more efficiently (P < .05) when this diet was supplemented with limiting amino acids, and phytase addition also increased (P < .05) weight gain, regardless of whether the diet was deficient or adequate in amino acids . Feed efficiency was improved (P < .05) by phytase addition to the amino acid-deficient diet but not to the amino acid-adequate diet . Pigs fed the low-CP, amino acid-fortified diet gained as fast and as efficiently as those fed a 19.5% CP (1.19% lysine) positive-control diet.

Curr Biol, 1996 Dec 1, 6(12), 1653 - 63
Mutations that suppress the thermosensitivity of green fluorescent protein; Siemering KR et al.; BACKGROUND: The green fluorescent protein (GFP) of the jellyfish Aequorea victoria has recently attracted great interest as the first example of a cloned reporter protein that is intrinsically fluorescent . Although successful in some organisms, heterologous expression of GFP has not always been straight forward . In particular, expression of GFP in cells that require incubation temperatures around 37 degrees C has been problematic . RESULTS: We have carried out a screen for mutant forms of GFP that fluoresce more intensely than the wild-type protein when expressed in E . coli at 37 degrees C . We have characterized a bright mutant (GFPA) with reduced sensitivity to temperature in both bacteria and yeast, and have shown that the amino acids substituted in GFPA act by preventing temperature-dependent misfolding of the GFP apoprotein . We have shown that the excitation and emission spectra of GFPA can be manipulated by site-directed mutagenesis without disturbing its improved folding characteristics, and have produced a thermostable folding mutant (GFP5) that can be efficiently excited using either long-wavelength ultraviolet or blue light . Expression of GFP5 results in greatly improved levels of fluorescence in both microbial and mammalian cells cultured at 37 degrees C . CONCLUSIONS: The thermotolerant mutants of GFP greatly improve the sensitivity of the protein as a visible reporter molecule in bacterial, yeast and mammalian cells . The fluorescence spectra of these mutants can be manipulated by further mutagenesis without deleteriously affecting their improved folding characteristics, so it may be possible to engineer a range of spectral variants with improved tolerance to temperature . Such a range of sensitive reporter proteins will greatly improve the prospects for GFP-based applications in cells that require relatively high incubation temperatures.

Proc Soc Exp Biol Med, 1996 Dec, 213(3), 248 - 57
The relevance of opioids and opioid receptors on immunocompetence and immune homeostasis; Carr DJ et al.; Since the previous review on the role of opioids in the immune system, numerous investigative teams have contributed to the growing pool of information illustrating the tangible relationship between opioids and immune function, particularly as this association pertains to bacterial and viral pathogens . In addition, the recent cloning of both neural- and immune-derived opioid receptors will ultimately facilitate the identification of molecular events that are responsible for the immunomodulatory effects that are mediated by receptor ligation . Specifically, the administration of opioids in vivo can potentially affect the immune system either through direct interaction with receptors on the effector cells or indirectly, through the ligation of receptors found within the central nervous system . This indirect routing is hypothesized to involve secondary pathways including the hypothalamic pituitary adrenal (HPA) axis and the sympathetic nervous system ultimately resulting in immunomodulation . Consequently, a portion of this review addresses the recent data on leukocyte-derived opioid receptors and the potential immunoregulatory role relative to opiold receptors found within the central nervous system . In addition, recent observations on the effects of opioids and immunocompetence is reviewed from both a molecular and cellular perspective . Finally, the consequence of opioid exposure on the competence of the host immune system to microbial pathogens is summarized.

J Neuroimmunol, 1996 Dec, 71(1-2), 3 - 10
Prior exposure to superantigen can inhibit or exacerbate autoimmune encephalomyelitis: T-cell repertoire engaged by the autoantigen determines clinical outcome; Das MR et al.; Experimental allergic encephalomyelitis (EAE) is inducible in experimental animals immunized with myelin basic protein (MBP), proteolipid protein (PLP) or their peptides . We compared T-cell responses to encephalitogenic epitopes of PLP(43-64) and MBP(Ac1-11) in a single mouse strain, (PL/J x SJL)F1 . MBP(1-11)-specific T-cell hybridomas expressed predominantly TCR V beta 8 or V beta 4, while PLP(43-64)-specific hybridomas expressed a diverse TCR repertoire . To analyze the biologic significance of the TCR repertoire (limited vs . diverse) to disease susceptibility, we pretreated mice with a superantigen (SEB), and then induced disease with these autoantigens . Mice injected with SEB and immunized with MBP(Ac1-11) showed significant inhibition of EAE, whereas SEB-pretreated mice immunized with PLP(43-64) had an increased severity of EAE and developed a chronic disease . These data demonstrate that prior exposure to microbial superantigens can significantly alter the autoimmune disease course depending upon the TCR repertoire used by the autoantigen.

Med Anthropol Q, 1996 Dec, 10(4), 657 - 74
Technology and alternative cancer therapies: an analysis of heterodoxy and constructivism; Hess DJ; Theories of the construction of technology are reviewed from the wider interdisciplinary conversation known as science and technology studies (STS) and from the growing field of the anthropology of science and technology . These theories are used to contribute to research situated at the intersection of the anthropology of alternative medicine and of medical technologies . Cases drawn from the research tradition on microbial theories of cancer are considered to show how unorthodox medical theories become embedded in technologies through choices in microscope design and treatment technologies . In turn, the technologies contribute to the heterodox standing of the researchers, their research, and their therapies.

Eur J Immunol, 1996 Dec, 26(12), 3230 - 3
Genetic control of anti-idiotypic vaccination against coronavirus infection; Yu MW et al.; The idiotypic network can be experimentally altered to induce protective immune responses against microbial pathogens . Both internal image and noninternal image anti-idiotypic (anti-Id) antibodies have been shown to trigger antigen (Ag)-specific immune responses . Therefore, mechanisms of anti-Id vaccination appear to go beyond structural mimicry of Ag, but remain undefined . Using the neurotropic murine coronavirus animal model, we have previously shown that a polyclonal noninternal image anti-Id (Ab2) could vaccinate BALB/c mice . To characterize its mode of action, we have examined the immune modulating capability of this Ab2 in vivo in strains of mice with different H-2 haplotypes . Even though only internal image anti-Id are expected to induce non-genetically restricted immunity, this noninternal image Ab2 induced protective immunity in four of eight genetically different strains of mice susceptible to coronavirus infection . These were BALB/c (H-2d), DBA/2 (H-2d), DBA/1 (H-2q), and SWR (H-2q) mice . Protection was generally correlated with the induction of specific antiviral Ab (Ab3) that showed biological properties, such as virus neutralization in vitro, similar to the initial Ab1 . To evaluate the genetic implication of the H-2 haplotypes in protection, congenic mice were also tested . Vaccination profiles suggest that cooperation between background gene(s) of the BALB/c mouse with H-2d and H-2q loci is necessary for an optimal protective immune response, although the main genetic element(s) regulating the antiviral response to Ab2 inoculation appeared to be located outside the major histocompatibility complex . These results are consistent with the ability of Ab2 to induce protective antiviral antibodies in genetically different animals by biological mimicry.

J Exp Med, 1996 Dec 1, 184(6), 2109 - 17
Apoptosis of Fashigh CD4+ synovial T cells by borrelia-reactive Fas-ligand(high) gamma delta T cells in Lyme arthritis; Vincent MS et al.; The function of the minor subset of T lymphocytes bearing the gamma delta T cell antigen receptor is uncertain . Although some gamma delta T cells react to microbial products, responsiveness has only rarely been demonstrated toward a bacterial antigen from a naturally occurring human infection . Synovial fluid lymphocytes from patients with Lyme arthritis contain a large proportion of gamma delta cells that proliferate in response to the causative spirochete, Borrelia burgdorferi . Furthermore, synovial gamma delta T cell clones express elevated and sustained levels of the ligand for Fas (APO-1, CD95) compared to alpha beta T cells, and induce apoptosis of Fashigh CD4+ synovial lymphocytes . The findings suggest that gamma delta T cells contribute to defense in human infections, as well as manifest an immunoregulatory function at inflammatory sites by a Fas-dependent process.

Appl Environ Microbiol, 1996 Dec, 62(12), 4556 - 62
Microbial dechlorination of historically present and freshly spiked chlorinated dioxins and diversity of dioxin-dechlorinating populations; Barkovskii AL et al.; The ability of a microbial consortium eluted from dioxin-contaminated Passaic River sediments to dechlorinate polychlorinated dibenzo-p-dioxins (PCDDs) was investigated under methanogenic conditions . Aged 2,3,7,8-tetraCDD, which had partitioned into the microbial consortium from sediments, was stoichiometrically converted to tri- and monoCDD congeners . During dechlorination, dominant microbial activity within the consortium shifted from methanogenic to nonmethanogenic activity . Freshly spiked octaCDD was converted to hepta-, hexa-, penta-, tetra-, tri-, di-, and monochlorinated isomers, but the reaction stoichiometry was not determined . No methanogenic activity was observed, and the maximum yield of protein coincided with the production of less-chlorinated DD congeners . Two distinct pathways of dechlorination were observed: the peri-dechlorination pathway of 2,3,7,8-substituted hepta- to pentaCDDs, resulting in the production of 2,3,7,8-tetraCDD, and the peri-lateral dechlorination pathway of non-2,3,7,8-substituted congeners . Direct evidence of further lateral dechlorination of 2,3,7,8-tetraCDD was obtained from the historically contaminated incubations; no isomer-specific identification of triCDDs in spiked incubations was determined . Pasteurized cells exhibited no peri-dechlorination pathway, and triCDDs were the least-chlorinated congeners produced in these treatments . These results demonstrate that (i) both freshly spiked and aged PCDDs are available to microbial reductive dechlorination, (ii) the peri and triCDD dechlorinations are attributed to activities of nonmethanogenic, non-spore-forming microbial subpopulations, and (iii) the 2,3,7,8-residue patterns in historically contaminated sediments are likely affected by microbial activity.

Hepatology, 1996 Dec, 24(6), 1517 - 29
A hitchhiker's guide to antisense and nonantisense biochemical pathways; Branch AD; Antisense pharmaceutical research has sought to provide drugs that would yield effective therapies for diseases resulting from the production of deleterious proteins . The original concept was straightforward: eliminate production of unwanted proteins, such as oncogenic proteins, by blocking the function of their mRNAs; and block their mRNAs by adding "antisense" nucleic acids that bind them through complementary base pairing . However, it has proven difficult to develop clinically useful antisense strategies . Conventional antisense nucleic acids are large, highly charged, complex molecules that interact with a wide variety of unintended cellular and microbial components, often causing "nonantisense effects." It is now clear that a broad knowledge of nucleic acid biochemistry will be needed to optimize antisense molecules for use in patients . The efficacy of naturally occurring antisense molecules and the success of antisense agricultural strategies prove that antisense approaches can be powerful and specific . Pharmaceutical antisense research can be expected to yield many valuable products once sufficient information about antisense mechanisms has been gathered and applied . This article explains the biochemical events that give rise to both antisense and nonantisense effects and provides guidelines for designing and evaluating antisense experiments.

Hepatology, 1996 Dec, 24(6), 1487 - 91
Stimulation of bile acid independent bile flow with bromo-cyclic guanosine monophosphate; St-Pierre MV et al.; The second messenger, cyclic guanosine monophosphate (cGMP), mediates the actions of nitric oxide, natriuretic peptides, and microbial toxins on cellular contractility and electrolyte movement . Because both hepatocellular contractility and electrolyte secretion participate in bile formation, we investigated the actions of cGMP on this process in intact liver . In rat liver perfused with 8-bromo-cyclic GMP (bcGMP) at 0.5 and 3 micromol/min, bile flow increased by 5% and 31%, respectively . The biliary excretion of the bile acid, taurocholate ({3H}-labeled; 1 micromol/min) and of the organic anion, bromosulfophthalein ({35S}-labeled; tracer dose), was unchanged . The paracellular and transcytotic pathways of biliary excretion, assessed by horseradish peroxidase (HRP), were unaffected . BcGMP was concentratively secreted into bile and the accompanying 30% increase in the biliary clearance of erythritol suggested that the choleresis was primarily osmotic in nature . Unlike cyclic adenosine monophosphate (cAMP), which stimulates bile acid dependent bile flow and transcytosis, bcGMP increased bile acid independent bile flow mainly as a result of its concentrative biliary secretion.

Mol Gen Genet, 1996 Nov 27, 253(1-2), 259 - 65
PHH1, a novel gene from Arabidopsis thaliana that encodes a protein similar to plant blue-light photoreceptors and microbial photolyases; Hoffman PD et al.; A cDNA from Arabidopsis thaliana similar to microbial photolyase genes, and designated AT-PHH1, was isolated using a photolyase-like cDNA from Sinapsis alba (SA-PHR1) as a probe . Multiple isolations yielded only PHH1 cDNAs, and a few blue-light-receptor CRY1 (HY4) cDNAs (also similar to microbial photolyase genes), suggesting the absence of any other highly similar Arabidopsis genes . The AT-PHH1 and SA-PHR1 cDNA sequences predict 89% identity at the protein level, except for an AT-PHH1 C-terminal extension (111 amino acids), also not seen in microbial photolyases . AT-PHH1 and CRY1 show less similarity (54% p4erein identity), including respective C-terminal extensions that are themselves mostly dissimilar . Analysis of fifteen AT-PHH1 genomic isolates reveals a single gene, with three introns in the coding sequence and one in the 5'-untranslated leader . Full-length AT-PHH1, and both AT-PHH1 and AT-PHH1 delta C-513 (truncated to be approximately the size of microbial photolyase genes) cDNAs, were overexpressed, respectively, in yeast and Escherichia coli mutants hypersensitive to ultraviolet light . The absence of significant effects on resistance suggests either that any putative AT-PHH1 DNA repair activity requires cofactors/chromophores not present in yeast or E . coli, or that AT-PHH1 encodes a blue-light/ultraviolet-A receptor rather than a DNA repair protein.

Structure, 1996 Nov 15, 4(11), 1263 - 75
The structure of the C-terminal domain of methionine synthase: presenting S-adenosylmethionine for reductive methylation of B12; Dixon MM et al.; BACKGROUND: In both mammalian and microbial species, B12-dependent methionine synthase catalyzes methyl transfer from methyltetrahydrofolate (CH3-H4folate) to homocysteine . The B12 (cobalamin) cofactor plays an essential role in this reaction, accepting the methyl group from CH3-H4folate to form methylcob(III)alamin and in turn donating the methyl group to homocysteine to generate methionine and cob(I)alamin . Occasionally the highly reactive cob(I)alamin intermediate is oxidized to the catalytically inactive cob(II)alamin form . Reactivation to sustain enzyme activity is achieved by a reductive methylation, requiring S-adenosylmethionine (AdoMet) as the methyl donor and, in Esherichia coli, flavodoxin as an electron donor . The intact system is controlled and organized so that AdoMet, rather than methyltetrahydrofolate, is the methyl donor in the reactivation reaction . AdoMet is not wasted as a methyl donor in the catalytic cycle in which methionine is synthesized from homocysteine . The structures of the AdoMet binding site and the cobalamin-binding domains (previously determined) provide a starting point for understanding the methyl transfer reactions of methionine synthase . RESULTS: We report the crystal structure of the 38 kDa C-terminal fragment of E.coli methionine synthase that comprises the AdoMet-binding site and is essential for reactivation . The structure, which includes residues 901-1227 of methionine synthase, is a C-shaped single domain whose central feature is a bent antiparallel betasheet . Database searches indicate that the observed polypeptide has no close relatives . AdoMet binds near the center of the inner surface of the domain and is held in place by both side chain and backbone interactions . CONCLUSIONS: The conformation of bound AdoMet, and the interactions that determine its binding, differ from those found in other AdoMet-dependent enzymes . The sequence Arg-x-x-x-Gly-Tyr is critical for the binding of AdoMet to methionine synthase . The position of bound AdoMet suggests that large areas of the C-terminal and cobalamin-binding fragments must come in contact in order to transfer the methyl group of AdoMet to cobalamin . The catalytic and activation cycles may be turned off and on by alternating physical separation and approach of the reactants.

Proc Natl Acad Sci U S A, 1996 Nov 12, 93(23), 13377 - 82
Three members of a novel small gene-family from Arabidopsis thaliana able to complement functionally an Escherichia coli mutant defective in PAPS reductase activity encode proteins with a thioredoxin-like domain and "APS reductase" activity; Gutierrez-Marcos JF et al.; Three different cDNAs, Prh-19, Prh-26, and Prh-43 {3'-phosphoadenosine-5'-phosphosulfate (PAPS) reductase homolog}, have been isolated by complementation of an Escherichia coli cysH mutant, defective in PAPS reductase activity, to prototrophy with an Arabidopsis thaliana cDNA library in the expression vector lambda YES . Sequence analysis of the cDNAs revealed continuous open reading frames encoding polypeptides of 465, 458, and 453 amino acids, with calculated molecular masses of 51.3, 50.5, and 50.4 kDa, respectively, that have strong homology with fungal, yeast and bacterial PAPS reductases . However, unlike microbial PAPS reductases, each PRH protein has an N-terminal extension, characteristic of a plastid transit peptide, and a C-terminal extension that has amino acid and deduced three-dimensional homology to thioredoxin proteins . Adenosine 5'-phosphosulfate (APS) was shown to be a much more efficient substrate than PAPS when the activity of the PRH proteins was tested by their ability to convert 35S-labeled substrate to acid-volatile 35S-sulfite . We speculate that the thioredoxin-like domain is involved in catalytic function, and that the PRH proteins may function as novel "APS reductase" enzymes . Southern hybridization analysis showed the presence of a small multigene family in the Arabidopsis genome . RNA blot hybridization with gene-specific probes revealed for each gene the presence of a transcript of approximately 1.85 kb in leaves, stems, and roots that increased on sulfate starvation . To our knowledge, this is the first report of the cloning and characterization of plant genes that encode proteins with APS reductase activity and supports the suggestion that APS can be utilized directly, without activation to PAPS, as an intermediary substrate in reductive sulfate assimilation.

J Biol Chem, 1996 Nov 8, 271(45), 28492 - 501
Salicylic acid is a modulator of tobacco and mammalian catalases; Durner J et al.; Salicylic acid (SA) plays a key role in the establishment of resistance to microbial pathogens in many plants . The discovery that SA inhibits catalase from tobacco led us to suggest that H2O2 acts as second messenger to activate plant defenses . Detailed analyses of SA's interaction with tobacco and mammalian catalases indicate that SA acts as an electron donor for the peroxidative cycle of catalase . When H2O2 fluxes were relatively low (1 microM/min or less), SA inhibited catalase, consistent with its suggested signaling function via H2O2 . However, significant inhibition was only observed at 100 microM SA or more, a level reached in infected, but not in uninfected, leaves . This inhibition was probably due to siphoning catalase into the slow peroxidative reaction . Surprisingly, SA was also able to protect catalase from inactivation by damaging levels of H2O2 (lower millimolar range), which is generally assumed to reflect accumulation of inactive ferro-oxy intermediates . SA did so by supporting or substituting for the protective function of catalase-bound NADPH . These results add new features to SA's interaction with heme enzymes and its in vivo redox properties . Thus, SA, in addition to its proposed signaling function, may also have an important antioxidant role in containing oxidative processes associated with plant defense responses.

Rev Invest Clin, 1996 Nov, 48 Suppl, 67 - 86
{Lactose-free formula products available in Mexico . Their significance and applications}; Rosado JL et al.; Lactose in milk and dairy products can be significantly reduced by the utilization of microbial beta-galactosidases . These enzymes can be used to treat milk during its processing or they can be administered with milk at meal time as an enzyme replacement therapy in which case hydrolysis occurs in vivo in the gastrointestinal tract . Lactose in milk can alternatively be eliminated by ultrafiltration, a process that divides milk components based on their size . A third way of reducing or eliminating lactose content is formulating a product or even "milk" from ingredients which avoid the use of lactose . Technologies like these are used to develop infant formula, enteral formula products and low-lactose milks . In this paper products of this kind available in Mexico are described.

Anticancer Res, 1996 Nov-Dec, 16(6B), 3695 - 703
Direct and indirect stimulation of megakaryocytopoiesis by TAN-1511 A, a microbial lipopeptide; Nishi K et al.; TAN-1511 A, a microbial lipopeptide, stimulates granulocytopoiesis through the induction of various hematopoietic cytokines . The ability of synthetic TAN-1511 A to affect megakaryocytopoiesis was examined . TAN-1511 . A augmented the activity of acetylcholine esterase (AChE), which is a cell-lineage marker enzyme of megakaryocytes in cultured murine bone marrow cells and enhanced megakaryocyte colony formation in fibrin clot culture . These effects were observed not only in the presence, but also in the absence of IL-3, which is a megakaryocyte colony-stimulating factor . The increase in AChE activity mediated by TAN-1511 A was blocked by anti-IL-6 but not anti-IL-3 or anti-GM-CSF neutralizing antibodies . RT-PCR analysis also showed that the remarkable induction of IL-6 was triggered by treatment with TAN-1511 A, while each message level of c-mpl ligand and c-mpl remained unchanged, suggesting that the IL-6 induced by the lipopeptide plays a role in enhanced megakaryocytopoiesis . TAN-1511 A also stimulated the proliferation of CMK86, a human megakaryoblastic cell line . This promoted growth was partially and additively affected by anti-IL-3, anti-IL-6, and anti-GM-CSF antibodies . TAN-1511 A slightly reduced the expression of GpIb and GpIIb/IL1a in CMK86 cells . The enhanced platelet recovery mediated by TAN-1511 A was also demonstrated in a model of myelosuppressive mice . These results suggest that TAN-1511 A directly affects megakaryocytopoiesis, and indirectly modulates megakaryocytopoiesis through the induction of cytokines such as IL-6.

J Dent Res, 1996 Nov, 75(11), 1827 - 34
Chemokine expression in human oral keratinocyte cell lines and keratinized mucosa; Bickel M et al.; Chemoattractant cytokines regulate the immune response within the tissue by recruiting neutrophils and macrophages . These so-called chemokines include a large family of peptide molecules encoded by distinct genes . Their expression is controlled by a variety of microbial and host factors . Among host factors, interleukin-1 (IL-1) is thought to be a key regulator of tissue destruction and mediator of the local immune response . To study its influence on chemokine expression, we used a highly sensitive, semi-quantitative method to assess gene expression at the level of mRNA . RNA was extracted from human oral keratinocyte cell lines after treatment with recombinant human IL-1 . To test the method further and possibly establish a chemokine mRNA expression pattern, we also extracted RNA from healthy oral keratinized mucosa . Purified RNA was reverse-transcribed and subsequently amplified in a polymerase chain reaction (RT-PCR) by means of specific primer pairs . Amplified sequences were analyzed by agarose gel electrophoresis, visualized by ethidium bromide staining, transferred to nylon membranes, and hybridized to biotinylated oligonucleotide probes . Detection was achieved by streptavidin-conjugated alkaline phosphatase, a chemiluminescent substrate, and autoradiography . Autoradiographs were analyzed by densitometric measurements . IL-1 stimulation resulted in an increase of the chemokine mRNAs encoding interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and GRO gamma . Macrophage inflammatory protein-1 alpha (MIP-1 alpha) mRNA was not detectable in keratinocytes . In healthy oral mucosa, we found considerable variation between the subjects . Detection of chemokine mRNAs by RT-PCR proved to be sensitive, specific, and fast . It allows for the study of not only cell-line-derived RNA, but also of RNA isolated directly from biopsy material . The latter feature makes this method well-suited for diagnostic purposes.

J Antibiot (Tokyo), 1996 Nov, 49(11), 1110 - 8
Microbial glycosylation of macrolide antibiotics by Streptomyces hygroscopicus ATCC 31080 and distribution of a macrolide glycosyl transferase in several Streptomyces strains; Sasaki J et al.; In the course of our microbial transformation study on erythromycin derivatives, Streptomyces hygroscopicus ATCC 31080, which produces a polyether antibiotic carriomycin, was found to transform erythromycin derivatives to their inactivated derivatives . The structures of inactivated derivatives prepared by enzyme reaction using the cell extract, UDP-glucose (or UDP-galactose) and Mg2+ (or Mn2+) were elucidated on the basis of analysis of thei spectral data to be the compounds glycosylated at C-2' of a desosamine moiety, indicating that the enzyme is a macrolide glycosyl transferase (MGT) . The MGT activity of cell extract from S . antibioticus ATCC 11891, a producing organism of oleandomycin, could be distinguished from that of ATCC 31080, based on the ability to glycosylate tylosin . We examined 32 actinomycete strains producing such polyketides as macrolide and polyether antibiotics, and found that 15 strains of Streptomyces have macrolide glycosyl transferase activity . It suggests that the MGTs have been distributed among at least polyketide producing Streptomyces strains.

Maturitas, 1996 Nov, 25(3), 223 - 9
Lack of microbial proliferation and phototoxic potential of a new matrix patch for estradiol delivery; Mulberry GK et al.; OBJECTIVES: To examine the potential of a new matrix system developed for estradiol delivery to cause microbial proliferation under the occluded site or to cause acute phototoxicity reactions . METHODS: Twenty healthy post-menopausal women participated in a microbial proliferation study and 11 in a phototoxicity study . Both studies were single centre, single blind and placebo controlled . Microbial proliferation was assessed by quantitative counts of the total aerobic bacterial population and of eight individual species before patch application and after removal following a 4 day application period on the abdomen . Acute phototoxicity potential was assessed following an 8 h application period on the abdomen by irradiating the application site after patch removal with ultra violet A radiation and visible light and evaluating the sites for up to 48 h post irradiation . Non-irradiated active and placebo patches on the other side of the abdomen served as controls . RESULTS: Total aerobic bacterial populations both before and after the matrix patch application period were low as expected for dry skin . Separate counts of microbial species were also low and did not change in any meaningful or consistent manner after patch application . In the phototoxicity study, mild erythema was observed in some patients at 0, 0.5 and 24 h post patch removal with no differences between irradiated and non-irradiated sites . CONCLUSIONS: These two studies demonstrate that a new matrix patch developed for estradiol delivery does not promote microbial proliferation under the occluded patch site or cause acute phototoxicity following removal.

J Periodontol, 1996 Nov, 67(11), 1193 - 200
Bacterial colonization of bioabsorbable barrier material and periodontal regeneration; De Sanctis M et al.; The objective of the study was to evaluate bacterial colonization of the tooth-facing surface of bioabsorbable membranes and to determine its effect on the clinical outcome of membrane supported reconstructive periodontal surgery . Twenty systemically healthy subjects affected by chronic adult periodontitis were enrolled in the study . One non-furcation tooth site per patient, associated with an angular bony defect and a probing attachment loss of > 5 mm, was selected to be treated by means of a guided tissue regeneration procedure using a polyglicolactic membrane . Antibiotics (amoxicillin/clavulanate potassium 1 g per day) for 2 weeks were prescribed, in addition to the use of chlorhexidine for post-surgical plaque control . All patients were recalled once a week for 5 weeks for professional tooth cleaning . At 5 weeks sites with clinically exposed membranes underwent a second surgery to harvest residual barrier material which was analyzed by scanning electronic microscopic (SEM) for bacterial colonization . Sites with no membrane exposure at 5 weeks were allowed to heal without any other surgical intervention . Professional tooth cleaning and reinforcement of self-performed oral hygiene measures were given at 1 month intervals for the duration of the study . For each treated site the difference in probing attachment loss between baseline examination and a follow-up examination made 6 months after the second surgery was calculated . Gain of probing attachment was statistically (P < 0.001) greater in sites with no membrane exposure when compared to sites with partially exposed barrier material (4.2 +/- 0.5 vs . 3.3 +/- 0.6) . The results of SEM analysis revealed that bacterial colonization was evident in all the microscopic fields of the exposed areas of the membranes . In the mid-part of the membranes 16 out of 39 microscopic fields (41%) demonstrated microbial colonization, while no bacteria-positive field was observed in the most apical portion of the membranes . Regression analysis indicated that gain in probing attachment level was negatively correlated to microbial colonization of the mid-part of the membranes . It was suggested the midportion of the tooth-facing surface of polyglicolactic membrane is a critical area for the healing process since its bacterial colonization was detrimental to the outcome of the GTR surgery.

J Clin Periodontol, 1996 Nov, 23(11), 1039 - 46
Bacterial colonization of barrier material and periodontal regeneration; De Sanctis M et al.; The objective of this study was to evaluate the relationship between the presence of bacteria on the tooth-facing surface of ePTFE barriers and the clinical outcome of membrane supported reconstructive periodontal surgery . 20 systemically healthy subjects affected by chronic periodontitis were enrolled . One tooth site per patient, associated with an angular bony defect and a probing attachment loss of > 4 mm, was selected to be treated by means of a guided tissue regeneration procedure using an ePTFE barrier membrane . Antibiotics (Augmentin 1 g/day) for 2 weeks were prescribed . In addition to the use of chlorhexidine for post-surgical plaque control, all patients were recalled once a week for professional tooth cleaning . The barrier material was harvested for SEM analysis after 4-6 weeks . Professional tooth cleaning and reinforcement of sel-performed oral hygiene measures were given at 1 mouth intervals after membrane removal . For each treated site, the difference in probing attachment loss between baseline examination and a follow-up examination after 6 months of healing was calculated . The results of the SEM-analysis revealed that bacterial colonization was evident in the collar area of all the retrieved membranes . In the mid part of the membranes 30 out of 60 microscopic fields (50%) demonstrated microbial colonization, and in the most apical part 9 out of 60 fields (15%) . Regression analysis indicated that gain in probing attachment level was positively correlated to initial attachement loss and negatively correlated to microbial colonization of the mid part of the membranes . It was concluded that bacterial colonization in the mid part of the ePTFE membrane reduced the potential gain in probing attachment following GTR-therapy with almost 50%.

Br J Rheumatol, 1996 Nov, 35(11), 1082 - 90
Antigen-presenting cells but not lymphocytes in the joint may indicate the cause of reactive arthritis; Stagg AJ et al.; T cells and antigen-presenting cells (APC) accumulate in the joint in reactive arthritis and there are reports that the T cells are a population selected for responsiveness to the causative agent . In this work, the latter view is questioned by detailed studies of the antigen specificities of the lymphocytes within the joint (SFMC) and peripheral blood (PBMC) of patients with reactive arthritis triggered by infection with Chlamydia trachomatis . Using a hanging-drop microculture system . SFMC displayed enhanced responses not only to antigens from the triggering organism, but also to other antigens, including PPD and tetanus toxoid, to which the patients were likely to have had prior exposure . No evidence was obtained for a dominant cross-reactive T-cell response to epitopes common to these antigen preparations, confirming the polyclonal nature of the infiltrate . In contrast to the broad specificity of the T-cell infiltrate, two experimental approaches indicated that APC within the joint carried chlamydial antigen . The failure of antigen-bearing APC to interact with T cells at this site may underlie the inability to clear microbial antigen from the joint.

J Viral Hepat, 1996 Nov, 3(6), 293 - 9
Oxidative burst response of neutrophils primed with PreS1 antigen of hepatitis B virus in patients with chronic hepatitis B and convalescents; Sulowska Z et al.; The pathogenesis of liver damage in the course of hepatitis B virus (HBV) infection depends on the host's specific and non-specific immune response to various viral antigens . The role of polymorphonuclear neutrophils (PMN) in the natural immune reaction and during secondary microbial infections is well documented . Increased free radical production is associated with many pathological conditions such as shock, ischaemia or chronic inflammatory diseases . We studied the oxidative metabolism of neutrophils in patients with chronic HBV and after recovery (convalescents) . The effect of the PreS1 fragment of HBV antigen on some neutrophil functions in vitro was also examined . There were significant differences in the values of spontaneous and stimulated oxidative burst of neutrophils, measured using luminol-chemiluminescence, in patients with HBV when compared with the convalescents . PreS1 antigen did not by itself induce the respiratory burst in human neutrophils but it potentiated their response to a second stimulus . Hence we observed a priming of neutrophils, for an enhanced respiratory burst, by PreS1 antigen.

J Appl Bacteriol, 1996 Nov, 81(5), 501 - 8
Indices for performance evaluation of predictive models in food microbiology; Ross T; Two complementary measures are proposed as simple indices of the performance of models in predictive food microbiology . The indices assess the level of confidence one can have in the predictions of the model and whether the model displays any bias which could lead to 'fail-dangerous' predictions . The use of the indices is demonstrated using data collated from independent and published literature . This analysis supports previous reports that evaluation of predictive models by comparison to published microbial growth rate data may be inappropriate because of limitations in that data . The indices may fail to reveal some forms of systematic deviation between observed and predicted behaviour . It is concluded, however, that the indices provide an objective and readily interpreted summary of model performance and may serve as a first step towards the development of an objective and useful definition of the term 'validated model' in predictive food microbiology.

Arch Microbiol, 1996 Nov, 166(5), 301 - 7
Iron-limited growth and kinetics of iron uptake in Magnetospirillum gryphiswaldense; Schuler D et al.; Growth and magnetite formation in Magnetospirillum gryphiswaldense MSR-1 were found close to the maximum at an extracellular iron concentration of 15-20 microM . Ferrous iron was incorporated by a slow, diffusion-like process . Several iron chelators including various microbial siderophores were unable to promote transport of iron into the cells . In contrast, spent culture fluids stimulated the uptake of ferric iron in iron-depleted cells at a high rate, whereas fresh medium and transport buffer were unable to promote iron uptake . However, no siderophore-like compound could be detected in spent culture fluids by the Chrome Azurol S assay . Ferric iron uptake followed Michaelis-Menten kinetics with a Km of 3 microM and a Vmax of 0.86 nmol min-1 (mg dry weight)-1, suggesting a comparatively low-affinity, but high-velocity transport system . Iron incorporation was sensitive to 2,4-dinitrophenol and carbonylcyanide-m-chlorophenylhydrazone, indicating an energy-dependent transport process.

J Anim Sci, 1996 Nov, 74(11), 2785 - 802
Development of a mechanistic model of intake and chewing activities of sheep; Sauvant D et al.; A mechanistic model of intake and chewing activities was developed using data from confined sheep in order to integrate the relationships between feeding behavior and digestive processes . The model consists of two interconnected submodels . The ruminal digestion submodel describes flows of nutrients and is based on differential equations to simulate the dynamic evolution of particulate matter and volatile fatty acids (VFA) in the reticulorumen . The diet is characterized by cell wall content and its potential digestibility, by the proportion of large particles (LP) retained on a 1-mm mesh sieve, and by an index of palatability . Particle comminution occurs during eating and ruminating . Intake is determined from attributes of the diet, animal live weight, and satiety status . Particulate outflow is calculated from a description of the activity of the reticulo-omasal orifice . Microbial digestion rates vary with lag phase, chemical fraction, size of particles, and ruminal pH . The VFA are aggregated into one compartment . The feeding decision submodel distinguishes among eating, ruminating, and resting . The choice among these activities is decided at each minute of simulation according to the relative values of functions of intake motivation (FMI) and of satiety (FSAT) . The FMI function is based on diet palatability, energy balance, and the diurnal cycle . The FSAT function is determined by rumen load signals and energy balance . When the animal does not eat, the decision between ruminating and resting is related to the proportion of long particles in the rumen . Sensitivity analysis and validations indicate that the overall behavior of the model is adequate.

Int J Food Microbiol, 1996 Nov, 33(1), 65 - 83
Shelf life prediction: status and future possibilities; McMeekin TA et al.; Although there is rapid progress in the field of chemical detection technology, little of this technology appears to have found application in estimation of the remaining shelf life of foods and early detection of spoilage . Predictive microbiology aims to summarise the probable behaviour of specific spoilage organisms and the progression of spoilage processes in foods . The quantitative knowledge generated in the field of predictive microbiology provides a sound basis for the rational development of devices with which to monitor loss of product shelf life during storage, distribution and retail sale . To predict remaining shelf life accurately it is necessary, however, to consider the microbial ecology of the food system . Aspects of microbial ecology and physiology relevant to the spoilage of foods are briefly reviewed and the potential benefits of the use of predictive microbiology in shelf life estimation are described . These points are exemplified by reference to a modelling program undertaken to develop, validate and 'package' in an easily useable from, models of the effect of temperature, water activity and pH on the growth rate of psychrotrophic spoilage pseudomonads . Necessary properties of devices to monitor loss of shelf life are discussed . 'Bioindicators' are identified as potential monitors of spoilage and suggestions made for their development based on the concept of 'upper limiting bacterial growth' rates, for which preliminary evidence is presented.

Arch Surg, 1996 Nov, 131(11), 1155 - 63
Inhibition of nitric oxide with aminoguanidine reduces bacterial translocation after endotoxin challenge in vivo; Sorrells DL et al.; BACKGROUND: Administration of lipopolysaccharide (LPS) has been shown to increase bacterial translocation (BT) in vivo and in vitro . In addition, LPS upregulates inducible nitric oxide synthase expression in the intestinal epithelium-a phenomenon that can either enhance microbial killing, or alternatively, promote BT by impairing the gut barrier . OBJECTIVE: To determine the effect, if any, of an inhibitor of nitric oxide synthase, namely, aminoguanidine (AG), on BT after LPS challenge . DESIGN: Sprague-Dawley rats were randomized to receive either AG or normal saline solution via subcutaneously placed osmotic pumps (Alzet), followed 18 hours later by LPS injection (5 mg/kg or 20 mg/kg intraperitoneally) . Quantitative cultures of the cecum, mesenteric lymph nodes, liver, and spleen were obtained, and plasma nitrite and nitrate levels were measured at 24 hours . Transmembrane potential difference and mucosal permeability to fluorescein isothiocyanate-labeled dextran and fluorescein isothiocyanate-labeled Escherichia coli C25 were measured in the Using chamber . The intestinal membrane was examined by light, transmission electron, and confocal laser microscopy . RESULTS: Rats that were given high-dose LPS had elevated levels of nitrite and nitrate and a 100% incidence of BT . In contrast, AG infusion significantly reduced both BT (22%) and nitrite and nitrate levels . Animals that received LPS and normal saline solution had a significantly lower transmembrane potential difference than those that received LPS and AG . High-dose LPS resulted in sloughing of the apical enterocytes at the villus tips where bacterial entry seemed to occur, as seen with confocal laser microscopy . CONCLUSIONS: Inhibition of nitric oxide production with AG decreases BT after high-dose LPS challenge . The mechanism may involve increased cellular viability and decreased damage to the gut mucosal barrier in rats that receive AG.

Appl Environ Microbiol, 1996 Nov, 62(11), 4210 - 5
Molecular identification of bacteria from a coculture by denaturing gradient gel electrophoresis of 16S ribosomal DNA fragments as a tool for isolation in pure cultures; Teske A et al.; Molecular information about the bacterial composition of a coculture capable of sulfate reduction after exposure to oxic and microoxic conditions was used to identify and subsequently to isolate the components of the mixture in pure culture . PCR amplification of 16S ribosomal DNA fragments from the coculture, analyzed by denaturing gradient gel electrophoresis, resulted in two distinct 16S ribosomal DNA bands, indicating two different bacterial components . Sequencing showed that the bands were derived from a Desulfovibrio strain and an Arcobacter strain . Since the phylogenetic positions of bacteria are often consistent with their physiological properties and culture requirements, molecular identification of the two components of this coculture allowed the design of specific culture conditions to separate and isolate both strains in pure culture . This approach facilitates the combined molecular and physiological analysis of mixed cultures and microbial communities.

Appl Environ Microbiol, 1996 Nov, 62(11), 4162 - 7
Direct ribosome isolation from soil to extract bacterial rRNA for community analysis; Felske A et al.; A simple method that combines an adapted ribosome isolation method and a common RNA extraction step has been developed for selective recovery of intact rRNA from natural microbial communities in soil . After mechanical cell lysis, ribosomes are separated by centrifugation steps, avoiding massive humic acid contamination and RNA degradation . The protocol accommodates the complex composition of soils by blocking adsorbing surfaces and humic acids with polyvinylpyrrolidone and bovine serum albumin . A usual RNA extraction step yields rRNA accessible for hybridization or reverse transcription-PCR . Hybridization with specific oligonucleotide probes was used for group-specific yield comparison . By using a probe hybridizing to the 16S rRNA of the bacterial kingdom, total bacterial rRNA yield was estimated to be in the range of 0.2 microgram per g for different soils . Group-specific probes did not indicate a selectivity of the isolation procedure and differentiated the compositions of different soil microbial communities . The sequence diversity of the isolated RNA population was also revealed by temperature gradient gel electrophoresis of reverse transcription-PCR amplification products by using a region of the 16S rRNA as a target . The pattern obtained by this analysis differed from a similar one resulting from the separation of amplification products of community DNA preparations . This different view of the community composition is attributable to the correlation of ribosome numbers to the metabolic activity of bacteria in the habitat under observation.

Cornea, 1996 Nov, 15(6), 571 - 6
Results of large penetrating keratoplasty in microbial keratitis; Cristol SM et al.; Extensive corneal disease secondary to microbial keratitis can result in frank or impending corneal perforation requiring a large penetrating keratoplasty . In an 8-year period, 26 penetrating keratoplasties with recipient beds of > or = 9.5 mm were performed on 22 eyes: 11 for bacterial keratitis, 10 for fungal keratitis, and one for a mixed bacterial and fungal keratitis . The graft failed in 18 of 19 eyes (94.7%), with a median time to failure of 12.9 weeks in bacterial keratitis and 4.0 weeks in fungal keratitis . After large keratoplasty, 17 of 20 eyes (85.0%) maintained the structural integrity of the globe . The remainder became phthisical or required enucleation . With preservation of the structural integrity of the globe, a subsequent smaller optical penetrating keratoplasty is an option in some of these eyes.

Microb Ecol, 1996 Nov, 32(3), 323 - 35
Horizontal and Vertical Migration Patterns of Phormidium corallyticum and Beggiatoa spp . Associated with Black-Band Disease of Corals
Richardson LL.
An in situ field study of the motility patterns exhibited by Phormidium corallyticum and Beggiatoa spp . in black-band disease of corals was conducted over a 5-day period . Measurements were made at a spatial resolution of 50 &mgr;m to document the horizontal migration of black-band across living coral tissue, while vertical migrations within the band were documented by observation and macrophotography of the black-band surface . It was determined that horizontal migration occurred both day and night, with the fastest movements by the front of the band during the day and the back of the band at night . Beggiatoa would rise to the band surface at night, and would often remain above the cyanobacterial population during extended periods of illumination the following day . The migration patterns are discussed in terms of motility cues and microbial physiology.

Microb Ecol, 1996 Nov, 32(3), 293 - 303
Detection of the merA gene and its expression in the environment
Jeffrey WH, Nazaret S, Barkay T.
Bacterial transformation of mercury in the environment has received much attention owing to the toxicity of both the ionic form and organomercurial compounds . Bacterial resistance to mercury and the role of bacteria in mercury cycling have been widely studied . The genes specifying the required functions for resistance to mercury are organized on the mer operon . Gene probing methodologies have been used for several years to detect specific gene sequences in the environment that are homologous to cloned mer genes . While mer genes have been detected in a wide variety of environments, less is known about the expression of these genes under environmental conditions . We combined new methodologies for recovering specific gene mRNA transcripts and mercury detection with a previously described method for determining biological potential for mercury volatilization to examine the effect of mercury concentrations and nutrient availability on rates of mercury volatilization and merA transcription . Levels of merA-specific transcripts and Hg(II) volatilization were influenced more by microbial activity (as manipulated by nutrient additions) than by the concentration of total mercury . The detection of merA-specific transcripts in some samples that did not reduce Hg(II) suggests that rates of mercury volatilization in the environment may not always be proportional to merA transcription.

Biochem Biophys Res Commun, 1996 Oct 23, 227(3), 684 - 7
Lactacystin increases LDL receptor level on HepG2 cells; Miura H et al.; Low density lipoprotein (LDL) receptor expression is regulated by proteolysis of transcription factors, sterol regulatory element binding proteins . To investigate the involvement of proteasome in this regulatory process, the effect of lactacystin, a specific proteasome inhibiton of microbial origin, was tested on LDL receptor expression on HepG2 cells . The addition of lactacystin to the cell culture increased the number of LDL receptors, indicating that proteasome plays a down-regulatory role in LDL receptor expression.

Chem Biol Interact, 1996 Oct 21, 102(2), 79 - 92
Formation of mammalian metabolites of cyclobenzaprine by the fungus, Cunninghamella elegans; Zhang D et al.; The fungus, Cunninghamella elegans, was used as a microbial model of mammalian drug metabolism to biotransform a tricyclic antidepressant, cyclobenzaprine . Seventy-five percent of this drug at a concentration of 1 mM was metabolized within 72 h by C . elegans grown on Sabouraud dextrose broth . Milligram amounts of fungal metabolites were isolated by reversed-phase high performance liquid chromatography (HPLC) and their structures were characterized by 1H NMR spectroscopy, mass spectrometry, and UV spectroscopy analyses . The major fungal metabolites of cyclobenzaprine were 2-hydroxycyclobenzaprine (59%), N-desmethylcyclobenzaprine (21%), cyclobenzaprine trans-10,11-dihydrodiol (5%), N-desmethyl-2-hydroxy-cyclobenzaprine (3%), 3-hydroxycyclobenzaprine (3%), and cyclobenzaprine N-oxide (1%) . These fungal metabolites were used as standards to investigate the metabolism of cyclobenzaprine by rat liver microsomes . Rat liver microsomes also biotransformed cyclobenzaprine to produce similar metabolites as the fungus . The isotope labeling of 2-hydroxycyclobenzaprine by 18O2 and the trans-configuration of the dihydrodiol suggested that these reactions were catalyzed by cytochrome P-450 monooxygenases in C . elegans . These results also demonstrated that the fungal biotransformation system could be used to predict and synthesize the mammalian drug metabolites.

Arch Microbiol, 1996 Oct 17, 166(4), 224 - 33
Phenotype variability of identical genotypes: the need for a combined approach in cyanobacterial taxonomy demonstrated on Merismopedia-like isolates
Palinska KA, Liesack W, Rhiel E, Krumbein WE.
Five Merismopedia-like cyanobacterial strains were collected from microbial mats at Norderney Island, subcultured in the laboratory, and finally grown as unicyanobacterial cultures . As a sixth strain, Merismopedia glauca from the rising dbl quote, left (low)Sammlung von Algenkulturen" at Gottingen (SAG) was used for comparisons . According to morphological and physiological characteristics initially observed in the field and during initial subculturing, the five strains were assigned to the species Merismopedia glauca, Merismopedia punctata, or Merismopedia elegans . However, after prolonged maintenance under laboratory conditions, the formation of platelet-like colonies stopped, whereas cell sizes, production of extracellular polymeric substances, and division patterns were stably maintained . These physiological and morphological parameters allowed us to divide the six strains into two clusters . This division was further supported by the profiling of total cell protein and phycobilisomes using SDS-PAGE . The nearly complete 16S rDNA sequence of three of the six isolates was determined . The comparative sequencing analysis revealed an almost 100% identity of these three Merismopedia-like strains . The evolutionary distance dendrogram constructed placed this Merismopedia cluster into a common line of descent with Synechocystis sp . strain PCC6906 . Based on the analysis of common stretches of 1,050 nucleotides, the overall similarity between the sequence types of rising dbl quote, left (low)Merismopedia" and rising dbl quote, left (low)Synechocystis" is 96-97% . The values of the different methods for taxonomic classification of unicyanobacterial strains, the relationship of the cyanobacterial genera Merismopedia, Synechococcus, Synechocystis, and Eucapsis sp., and the functional role of different Merismopedia morphologies within microbial mats are discussed . It is suggested that all analyzed Merismopedia strains be combined into one species, namely Merismopedia punctata Meyen (1839).

Res Microbiol, 1996 Oct, 147(8), 625 - 35
Characterization of Escherichia coli strains isolated from environmental water habitats and from stool samples of healthy volunteers; Muhldorfer I et al.; This study was undertaken to determine the frequency of pathogenic Escherichia coli strains among wild-type E . coli strain isolates from the microbial flora of healthy volunteers and from natural residential water habitats of a defined geographic area . In total, 131 stool and 95 water isolates as well as 14 E.coli K12 strains were examined for DNA sequences specific for 20 different genes encoding E . coli pathogenicity factors, including adherence factors, toxins, invasins, capsules and iron uptake systems . The expression of the corresponding pathogenicity factors was also investigated . No pathogenicity factors were found to be present in the tested E . coli K12 strains . In contrast, 41.0% of the water samples and 63.4% of the stool samples contained pathogenicity factors specific for extraintestinal E . coli pathogens . While no virulence determinants specific for intestinal E . coli pathogens were found among the investigated environmental water isolates, 4.5% of the stool samples contained either only intestinal or both intestinal and extraintestinal virulence genes . Both the prevalence of the virulence genes and the expression of the corresponding pathogenicity factors were, in general, higher in stool than in water samples . These findings might indicate the prevalence of different clonal types and/or differential regulation of pathogenicity factor expression in diverse ecological niches.

Mol Immunol, 1996 Oct, 33(15), 1183 - 96
Plasmacytoma-refractory BALB/cAnPt mice have naive T cell and highly specific B cell responses to antigen; McDonald AH et al.; Recently, a reduction in the incidence of pristane-induced plasmacytomas in BALB/cAnPt (BALB/c) mice that were kept in viral specific pathogen-free (SPF) conditions has been reported . Environmentally, these SPF-BALB/c mice differed from conventionally-housed (CON) mice only in viral exposure and diet (i.e . sterilization of mouse chow), since microbial colonization of the intestinal tract was seen to be equivalent . This report assessed the ability of SPF- and CON-BALB/c mice to respond to immunologic challenge with soluble antigen, i.e . hen egg white lyzosyme (HEL), as a means of evaluating differences in T and B cell function and, indirectly, evaluating the possible effects these differences might have on plasmacytoma development . When cultured in vitro for 5 days with HEL, HEL-primed lymph node cells (LNC) from SPF-BALB/c mice proliferated to a significantly lesser extent than HEL-primed CON-BALB/c LNC . Moreover, HEL-induced production of IFN-gamma and IL-5 was significantly lower in SPF LNC . Serum IgG1 levels were 10-fold lower in SPF-BALB/c mice with, or without prior immunization with HEL and were not reconstituted by repeated injections of HEL in adjuvant . Serum IgM levels of SPF- and CON-BALB/c mice were equivalent . This reduction in immune responses could not be attributed to a lack of colonization of secondary lymphoid organs, since flow cytometric analysis of LNC revealed no difference in the number of recoverable cells and the proportion of lymphocyte subsets (CD4+, CD8+ and CD45+ cells) obtained from SPF- and CON-BALB/c mice . However, only CON LNC were induced to increase surface expression of CD44 after antigenic or mitogenic stimulation in vitro . Antibody responsiveness to HEL, as evidenced by serum anti-HEL binding or splenic hybridoma studies, demonstrated higher levels of IgG1 antibodies in CON BALB/c mice than in SPF mice . However, a greater proportion of the SPF IgG1 antibodies present were specifically directed against HEL, so that specific activity was greater in SPF-BALB/c mice . Therefore, while SPF BALB/c mice have a more restricted response to HEL than CON-BALB/c mice, those antibodies that are produced are more specifically directed against HEL with very little apparent bystander/polyclonal activation of multireactive cells . Resistance to plasmacytomas in SPF-BALB/c mice, therefore, may stem from a reduced number of circulating memory T and B cells, which are capable of reacting and/or crossreacting with a chronic inflammatory stimulus.

West Afr J Med, 1996 Oct-Dec, 15(4), 190 - 5
Consequences of inadvertent microbial contamination of dextrose solutions; Mendie UE et al.; Most intravenous infusion fluids and non-sterile liquid products contain dextrose which serves as a sweetener or an energy source for critically ill or traumatized patients . Hence dextrose was critically examined for stability in the presence of some micro-organism which are commonly known to contaminated i.v . infusion fluids . In the presence of these test organisms, the dextrose component of these solutions was found to be remarkably degraded with average rates of 0.065-3.153% per hour depending on the type of organism . Micro-organisms such as Ps . aeruginosa and E . coli gave low rates of degradation of 0.065-0.88% per hour while the values of 0.770-3.153% per hour were obtained for K . pneumonia; B-lac+ Staph . aureus and B . subtilis . The degradation of dextrose by C . albicans however, increased with dextrose concentration with average rate of 1.147-1.21% per hour . The degradations were gradually accompanied by increases in total acidity and decreases in pH of the dextrose solutions . The variation in the rates of degradation of dextrose by the test organisms is attributable to their survival rates in dextrose solutions and it is of great significance especially at the low inoculum size of 100 cells/ml . The results thus obtained necessitate the maintenance of a high level of aseptic procedures to prevent inadvertent contamination of i.v . fluids and other glucose containing solutions during clinical and other use conditions.

J Antibiot (Tokyo), 1996 Oct, 49(10), 967 - 73
ZG-1494 alpha, a novel platelet-activating factor acetyltransferase inhibitor from Penicillium rubrum, isolation, structure elucidation andbiological activity; West RR et al.; A novel inhibitor of platelet-activating factor (PAF) acetyltransferase, an essential enzyme in the remodeling pathway of platelet-activating factor synthesis, was identified by a high throughout screen of natural product extracts of microbial origin . The compound, ZG-1494 alpha, was isolated from an ethyl acetate extract of a culture broth of Penicillium rubrum through bioassay guided fractionation . The structure of ZG-1494 alpha was determined by spectroscopic methods . A key feature of the structure, which is relatively rare among natural products, is the 5-hydroxy-3-pyrrolin-2-one moiety . A 13C-13C INADEQUATE was utilized to unambiguously determine the regiochemistry of this molecule.

Electrophoresis, 1996 Oct, 17(10), 1627 - 32
Analysis of the biotin-binding protein actinavidin using affinity capillary electrophoresis; Okun VM et al.; Affinity capillary electrophoresis (ACE) was applied to study the bioaffinity of ligand-receptor interaction between the microbial biotin-binding protein actinavidin and biotin . The ACE method is based on short time incubation of a mixture of actinavidin and increasing concentrations of biotinylated oligonucleotide (bio-ON), which was found to be an effective affinity ligand . Separation of intermediate loading forms of actinavidin from unbound ligand in the presence of micellar phase and by capillary zone electrophoresis enabled the quantitation of free bio-ON, permitting the evaluation of the biotin-binding capacity of actinavidin in absence and presence of sodium dodecyl sulfate (SDS) . Although in the latter case actinavidin lost a part of its binding capacity (not more than 12%), it was still possible to develop an indirect, noncompetitive assay for the determination of actinavidin in culture liquid, utilizing the combination of micellar electrokinetic capillary chromatography (MEKC) and ACE . Due to the affinity interaction, actinavidin in the sample decreases the amount of bio-ON added, enabling quantitation of the protein . SDS, which is required in this assay to prevent protein adsorption to the capillary wall, greatly enhances the reproducibility and peak shape . Actinavidin levels determined are in agreement with those obtained by commonly used solid-phase analysis . The limit of detection was about 500 ng/mL . Thus the proposed method was found to be well suited for the evaluation of actinavidin affinity and monitoring of its levels in cultivation process.

Immunology, 1996 Oct, 89(2), 268 - 73
Development and cytolytic function of intestinal intraepithelial T lymphocytes in antigen-minimized mice; Kawaguchi-Miyashita M et al.; Intraepithelial T lymphocytes in the small intestine (IEL) consist of alpha beta T-cell receptor (TCR)-bearing T cells (alpha beta-IEL) and gamma delta TCR-bearing T cells (gamma delta-IEL) . Development and cytolytic activation of alpha beta-IEL sharply attenuate in germ-free (GF) mice fed a natural diet (Nat-GF), but the number and cytotoxicity of gamma delta-IEL are comparable between conventional (CV) and Nat-GF mice . In this report, we compared the properties of IEL in Nat-GF mice and GF mice fed antigen-minimized diet (AgM-GF mice) of C57BL/6 strain to evaluate an influence of gut antigenic load on IEL development . Numbers of alpha beta-IEL and gamma delta-IEL in AgM-GF mice were less by 1.9- and 1.4-fold than those in Nat-GF mice, respectively . Significant decreases in the proportions of CD4+8-, CD4-8 alpha beta +, and CD4+8+ subsets and a resultant increase in the ratio of CD4-8 alpha alpha + subset were evident in alpha beta-IEL of Nat-GF mice compared with CV mice, but the subset constitution of alpha beta-IEL was similar between Nat-GF and AgM-GF mice . In contrast, relative composition of gamma delta-IEL was not different between CV, Nat-GF, and AgM-GF mice . alpha beta-IEL displayed low cytolytic activity in Nat-GF mice and were almost deprived of their cytotoxicity under the antigen-minimized condition . While gamma delta-IEL were strongly cytolytic in Nat-GF mice their cytolytic activity was remarkably reduced in AgM-GF mice . These results indicate that gamma delta-IEL are activated independently of microbial colonization in the gastrointestinal tract but their activation occurs in response to the exogenous antigenic substances other than live micro-organisms.

Int J Biochem Cell Biol, 1996 Oct, 28(10), 1123 - 30
Geotrichum candidum P-5 produces an intracellular serine protease resembling chymotrypsin; Litthauer D et al.; A wide range of intra- and extracellular microbial proteases has been studied and characterized . These enzymes are mostly extracellular and in some cases they may resemble 'classical' serine proteases . As part of a programme in which the lipase and protease activities of the fungus Geotrichum candidum are being studied, an intracellular protease with an apparent chymotrypsin-like specificity was detected . The serine protease was isolated from biomass using ion-exchange and exclusion chromatography . Kinetic characterization was done using a series of synthetic substrates and inhibitors . Aprotinin-sepharose affinity chromatography was used to isolate a fraction for molecular size determination on SDS-PAGE . The purified protease, which could hydrolyse haemoglobin as protein substrate, was obtained with a 30-fold purification and a yield of 44%, but it was very unstable and rapidly lost activity . The enzyme which bound to the affinity column had a single subunit mass of 278 kDa . Kinetic analysis showed a similarity with trypsin and chymotrypsin, but tending more towards chymotrypsin in that a bulky aromatic group, e.g . phenylalanine in the P1 position, was preferred . The optimum pH was in the region of 7-8.25 . Inhibition patterns indicated that the enzyme was a serine protease with no metal dependence, although it was stabilized by magnesium ions . The enzyme seems to share some properties with other intra- and extracellular microbial serine proteases . The exact function of the enzymatic activity is still unclear, but it is suggested that it may be involved with intracellular protein turnover.

J Dairy Sci, 1996 Oct, 79(10), 1802 - 08
Lasalocid effects on ruminal degradation of protein and postruminal supply of amino acids in Holstein steers; Wessels RH et al.; Five ruminally and duodenally cannulated Holstein steers (305 kg) were used in a switchback experiment with three periods to evaluate two experimental treatments: a basal diet with or without 45 ppm of lasalocid . The basal diet contained approximately 43% rolled corn, 45% alfalfa hay, and 10% soybean meal (DM basis) . Lasalocid did not affect feed intake or ruminal digestion of OM and NDF . Ruminal digestion of ADF tended to increase with supplemental lasalocid . Total tract digestion of OM, NDF, ADF, and N and intestinal flow of amino acids were not affected by lasalocid . Also, the ratio of microbial to nonmicrobial N fractions at the duodenum remained unchanged . Ruminal pH and concentrations of NH3, VFA, peptides, and amino acids were not affected by lasalocid . Ruminal protease activity decreased with supplemental lasalocid, but this decrease was not reflected in other variables, such as ruminal concentrations of peptides and amino acids . Ruminal deaminase activity remained unchanged . Thus, we concluded that dietary lasalocid did not alter ruminal protein degradation or postruminal flow of amino acids.

Fundam Appl Toxicol, 1996 Oct, 33(2), 173 - 81
Subchronic, developmental, and genetic toxicology studies with the ethane sulfonate metabolite of alachlor; Heydens WF et al.; The ethane sulfonate (ESA) metabolite of the herbicide alachlor is formed in soil by microbial action . The present studies were conducted to assess the toxicity of ESA and provide a base set of data for risk assessment . ESA did not induce chromosomal effects in a mouse bone marrow micronucleus assay following acute administration . Administration of ESA to rats in drinking water at concentration of 200, 2000, and 10,000 ppm for 91 days elicited biologically significant indications of toxicity only at the high-dose level (1002 mg/kg/day) . The observed responses included decreases in body weights and food consumption as well as effects on clinical chemistry values . Many of the changes appeared to be due to decreased palatability of the drinking water . There were no ESA-induced gross pathology findings, organ weight changes, or microscopic lesions . ESA did not produce any adverse effects in pregnant rats or their offspring even at 1000 mg/kg/day, the highest dose tested . These findings show that the subchronic and developmental toxicity of ESA are low . Furthermore, comparison of results from studies with alachlor and its metabolite shows that the toxicity of ESA is substantially lower . Margins of exposure for ESA range from 133,824 to 2,573,529 even using worst-case estimates of exposure, indicating that the metabolite poses little risk of producing adverse effects at the very low levels occasionally encountered . These results and accompanying analyses support the conclusion that ESA is not of toxicological concern.

Curr Opin Struct Biol, 1996 Oct, 6(5), 692 - 702
Syntheses and some applications of chemically defined multivalent glycoconjugates; Roy R; Classical multivalent neoglycoproteins have been widely used to study a great number of carbohydrate-protein interactions . The synthesis of other neoglycoconjugates with various shapes, valencies, and conformations has reached considerable levels of sophistication and holds promise as a new tool for glycobiology and biomedical applications . Within the last few years, advances have been made towards both the syntheses and understanding of the antigenic properties of water-soluble glycopolymers . Some of these glycopolymers are finding applications as inhibitors of microbial adhesins and as carriers for drug delivery to specific cells . Novel dendritic carbohydrate structures are emerging as potent ligands for carbohydrate-binding proteins.

Int J Biol Macromol, 1996 Oct, 19(3), 171 - 6
Intracellular depolymerase functionality and location in Pseudomonas oleovorans inclusions containing polyhydroxyoctanoate; Stuart ES et al.; Microbial poly-3-hydroxyoctanoate inclusion bodies produced by Pseudomonas oleovorans when grown on n-octanoic acid, are complex macromolecular structures consisting of polyester, organized paracrystalline lattice arrays and lipids . While it is known that the polymer in the granules maintains its native, amorphous state while it is surrounded by the components of this complex, the precise functions of the various components during polymer production and utilization have yet to be established . By utilizing electron microscopy, SDS-PAGE, and gel filtration chromatography along with in vitro assays for depolymerase activity, the present study demonstrates that a protein species with molecular weight of approximately 32 kDa is the depolymerase protein of the polymer inclusion . When exogenous carbon was exhausted, cell viability required utilization of the stored polyester . Under these conditions, the concentration of the depolymerase increased while the concentrations of the polymerase decreased . Thus, the association of the depolymerase with the granules was shown to be under metabolic regulation relative to the polymerase . The results from the present studies show that careful manipulation of the substrate concentration can selectively, and differentially, alter the level of inclusion associated proteins as well as the quantity and quality of the polyester which is accumulated.

J Anim Sci, 1996 Oct, 74(10), 2310 - 6
Influence of dietary forage level and forage coarseness of grind on growth performance and digestive function in feedlot steers; Calderon-Cortes JF et al.; We conducted two trials to examine the influence of dietary forage level (FL; 16 and 8% sudangrass hay) and forage coarseness of grind (COG; ground to pass through a 2.5- vs 7.6-cm diameter screen) on growth performance and digestive function in feedlot steers fed a steam-flaked corn-based finishing diet . Thirty-two Mexican crossbred steers (297 kg) were used to determine treatment effects on growth performance during an 80-d finishing period . There were no treatment interactions (P > .10) . Reducing FL increased (17%, P < .05) ADG . decreased (23%, P < .01) feed/gain, and increased (17% and 22%, P < .01) dietary NEm and NEg . Coarseness of grind did not affect (P > .10) steer performance . Treatment effects on digestive function were evaluated using four Holstein steers with cannulas in the rumen and proximal duodenum . There were no treatment interactions (P > .10) on nutrient digestibility . Forage level did not affect (P > .10) ruminal digestion of OM, N, or microbial efficiency . However, decreasing FL increased (P < .05) total tract digestion of OM (5.0%), N (5.7%), and ME (8.7%) . Increasing COG increased total tract digestibility of OM (2.3%, P < .01), ADF (24.4%, P < .01); N (3.8%, P < .01), and ME (3.7%, P < .05) . Increasing FL increased (P < .10) ruminal pH and decreased (P < .10) ruminal molar proportions of butyrate . Increasing COG did not influence (P > .10) ruminal pH or ruminal VFA molar proportions . We conclude that increasing coarseness of ground sudangrass may not improve the performance of feedlot steers when the forage is fed at either 8 or 16% of diet DM, although measures of ruminal and total tract nutrient digestibility may be slightly increased.

J Anim Sci, 1996 Oct, 74(10), 2303 - 9
Interaction of dietary calcium and supplemental fat on digestive function and growth performance in feedlot steers; Zinn RA et al.; Four Holstein steers (261 +/- 2 kg) with cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square experiment to evaluate the interaction of dietary Ca (.45 vs . 90%) and supplemental fat (0 vs 5% yellow grease) on characteristics of digestion . There were no treatment interactions (P > .10) . Supplemental Ca did not influence (P > .10) digestibility of OM, NDF, starch, N, and fatty acids . Supplemental fat decreased ruminal (21%, P < .05) and total tract (3%, P < .01) digestibility of OM and ruminal (25%, P < .10) and total tract (20%, P < .01) digestibility of NDF . Supplemental fat increased (P < .10) ruminal microbial efficiency . Ruminal free Ca was not affected (P > .10) by Ca intake but was closely associated with ruminal pH and fatty acid intake (R2 = .84) . Apparent ruminal Ca absorption was generally negative, being increased (P < .05) by Ca supplementation and decreased (P < .10) by fat supplementation . Postruminal (P < .05) and total tract (P < .01) apparent Ca absorption was increased by Ca supplementation . Supplemental fat did not influence (P > .10) postruminal or total tract Ca absorption . One hundred forty-four medium-frame crossbred steers were used to evaluate treatment effects on feedlot growth performance . There were no treatment interactions (P > .10) . Increasing dietary Ca did not influence (P > .10) steer performance . Supplemental fat decreased (P < .01) DMI and increased NE value of the diet (P < .01) . It is concluded that increasing dietary Ca from .45 to .9% in high-grain finishing diets will not affect the feeding value of supplemental fat and that high levels (5%) of supplemental fat will not have a detrimental effect on Ca absorption.

Can J Microbiol, 1996 Oct, 42(10), 1051 - 60
In vitro degradation of dicyclopentadiene by microbial consortia isolated from hydrocarbon-contaminated soil; Stehmeier LG et al.; Degradation of dicyclopentadiene (DCPD) to carbon dioxide and oxygenated intermediates was established in the laboratory . Screening of many inocula using BIOLOGMT plates showed that no single colony isolate readily mineralized DCPD . Mixed cultures from a variety of environmental sources produced 14CO2 when incubated with {14C}DCPD, but most of the DCPD was metabolized to oxygenated intermediates that could be extracted from the culture liquid and detected using gas chromatography and mass spectroscopy . Stimulation of environmental inocula with nutrients and preexposure to DCPD before testing for degradation gave mineralization rates after 25 days of in vitro incubation that were twice as fast as those previously reported.

Am J Clin Pathol, 1996 Oct, 106(4), 504 - 10
Bronchoalveolar lavage cytology in pulmonary alveolar proteinosis; Burkhalter A et al.; Pulmonary alveolar proteinosis (PAP) is an uncommon disease in which alveoli are progressively filled with surfactant-related material . Although a definitive diagnosis is usually made by an open lung biopsy, bronchoalveolar lavage (BAL) cytology may play a decisive role in the clinical work-up of these patients, and, in some cases, may spare a patient a more invasive diagnostic procedure . The authors present three patients in whom BAL cytology specimens contained the characteristic (although not specific) globules of amorphous proteinaceous PAS-positive material accompanied by only rare background macrophages and inflammatory cells . The patients include a 40-year-old man with an 8-year history of fever of unknown origin, a 30-year-old man with a chronic nonproductive cough, and a 6-year-old boy diagnosed at 5 months of age with osteopetrosis and hypogammaglobulinemia who subsequently developed a disseminated Mycobacterium avium-intracellulare infection . All specimens stained with Gomori methenamine silver (3) and Ziehl-Neelsen (2) were negative for microbial organisms, Ultrastructural examination of two specimens revealed the characteristic lamellar structures of surfactant, increasing diagnostic specificity . Lung biopsies and/or autopsy subsequently confirmed the diagnosis in all three cases . The characteristic cytologic and ultrastructural features of PAP in BAL specimens are presented along with the morphologic differential features of other entities which potentially could be confused with PAP.

J Am Vet Med Assoc, 1996 Oct 1, 209(7), 1283 - 6
Eosinophilic keratoconjunctivitis in seven horses; Yamagata M et al.; Eosinophilic keratoconjunctivitis was diagnosed in 7 horses at The Ohio State University between 1976 and 1994 . All horses had moderate-to-severe blepharospasm, chemosis, and conjunctival hyperemia; epiphora; and extensive yellow-to-white caseous mucoid discharge . Corneal ulcers associated with this disease were perilimbal and extended centrally . All ulcers were covered with a white necrotic plaque firmly attached to the underlying cornea . Other ophthalmic abnormalities were not detected . Corneal scrapings examined cytologically contained numerous eosinophils interspersed between epithelial cells, few mast cells, and neutrophils . Microbial organism were not seen . Bacterial and fungal cultures were negative for ocular pathogens . The initial diagnosis of eosinophilic keratoconjunctivitis was made on the basis of clinical and cytologic findings . In 5 horses, the condition completely resolved after topical treatment with corticosteroid (0.05% dexamethasone) and triple antibiotic ointments . However, the duration of treatment was prolonged, with a mean treatment time of 64 days (range, 45 to 106 days) . All corneal ulcers remained superficial, and despite the prolonged duration of treatment, none of the horses developed secondary bacterial or fungal keratitis . One horse underwent superficial keratectomy and had the shortest resolution time (14 days).

J Immunol, 1996 Oct 1, 157(7), 3089 - 96
Tumor necrosis factor-alpha modulates the expression of its p60 receptor and several cytokines in rat tracheal epithelial cells; Bader T et al.; The epithelium of the conducting airways is frequently the target of toxic chemical and microbial agents causing inflammation, hypersecretion, and epithelial necrosis . TNF-alpha is a prototypical inflammatory cytokine released by macrophages and other inflammatory cells . The purpose of this study was to characterize TNF-alpha receptors in fully differentiated rat tracheal epithelial (RTE) cells in culture and to examine the effects of TNF-alpha on this epithelium . We demonstrated the presence of approximately 250 TNF-alpha receptors per RTE cell . Both known receptor types, p60 (TNF-RI, CD 120a) and p80 (TNF-RII, CD 120b), were expressed . The level of p80 mRNA was unaffected by TNF-alpha treatment, whereas p60 mRNA was down-regulated, and soluble TNF-RI was shed from cells within 30 min . Treatment of RTE cultures with TNF-alpha (1000 U) caused no cytotoxicity (as determined by lactate dehydrogenase release) . However, TNF-alpha exposure of the cultures induced the expression of several inflammatory mediators, as determined by reverse transcription-PCR and ELISA . Low levels of IFN-gamma mRNA became detectable after 4 h . Increased levels of TNF-alpha mRNA and protein were found, which peaked after 6 h of TNF-alpha treatment, but neither IL-1 alpha nor IL-1 beta was detectable . Calcium-independent nitric oxide synthase transcripts were elevated two- to threefold within 2 to 6 h of TNF-alpha treatment . These findings suggest that the airway epithelium may actively participate in the pathogenesis of airway inflammation through the production of mediators similar to those found in a Th1 response.

Eur J Nucl Med, 1996 Oct, 23(10), 1384 - 7
Detection of anaerobic odontogenic infections by fluorine-18 fluoromisonidazole; Liu RS et al.; Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation . Anaerobic microbial infections are the most common causes . This study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections . Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10 mCi) of FMISO in 26 nasopharyngeal carcinoma patients and six controls with healthy teeth . Tomograms were interpreted visually to identify hypoxic foci in the jaw . All patients received thorough dental examinations as a pre-radiotherapy work-up . Fifty-one sites of periodontitis, 15 periodontal abscesses, 14 sites of dental caries with root canal infection, 23 sites of dental caries without root canal infection, and seven necrotic pulps were found by dental examination . Anaerobic pathogens were isolated from 12 patients . Increased uptake of FMISO was found at 45 out of 51 sites of periodontitis, all 15 sites of periodontal abscess, all 14 sites of dental caries with root canal infection, all seven sites of necrotic pulp and 15 sites of dental caries without obvious evidence of active root canal infection . No abnormal uptake was seen in the healthy teeth of patients or in the six controls . The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of FMISO PET scan in detecting odontogenic infections were 93%, 97%, 84%, 99% and 96%, respectively . 18F-fluoride ion bone scan done in three patients showed that 18F-fluoride ion plays no role in the demonstration of anaerobic odontogenic infection . FMISO PET scan is a sensitive method for the detection of anaerobic odontogenic infections, and may play a complementary role in the evaluation of the dental condition of patients with head and neck tumours prior to radiation therapy.

Blood, 1996 Sep 15, 88(6), 2151 - 61
Evidence for an in vivo superantigenic activity in human immunodeficiency virus-infected individuals; Garcia S et al.; In a previous study, we reported the existence of a specific anergy affecting selectively the V beta 8 subset in both CD4 and CD8 T cells from human immunodeficiency virus (HIV)-infected persons . Because this observation gives evidence for a previous in vivo activation of this subset by a superantigen, we further characterize, in the present study, this V beta 8-anergy associated with HIV infection . Molecular T cell receptor analysis indicates that the V beta 8-anergized T cells are polyclonal . Furthermore, we show the dependence of this anergy on the expression of allelic forms of HLA class II DRB1 molecules . These observations explain the frequency of anergic persons among HIV-infected donors (56%) and are consistent with a previous in vivo superantigenic activity . Comparative analyses of disease evolution between V beta 8 responder and anergic persons do not show any clear relation between the V beta 8 status and acquired immunodeficiency syndrome pathogenesis . However, the stability of the V beta 8 status, the absence of correlation with previous microbial infections, and the previously reported precocity of V beta 8 anergization are in favor of a strong association between the in vivo existence of a V beta 8-specific superantigen and HIV infection . Finally, the functional dichotomy we observe for all anergized donors between blood and lymph node T cells raises the question of the in vivo localization of the superantigenic activity.

J Immunol, 1996 Sep 15, 157(6), 2528 - 38
IL-10 enhances the growth of Legionella pneumophila in human mononuclear phagocytes and reverses the protective effect of IFN-gamma: differential responses of blood monocytes and alveolar macrophages; Park DR et al.; Legionella pneumophila is a facultative intracellular pathogen that parasitizes human alveolar macrophages and blood monocytes recruited to the lungs . The inhibitory cytokines IL-10, TGF-beta, and IL-4 generally deactivate macrophages and permit enhanced microbial growth in some models of intracellular infection, but their effects on human alveolar macrophages are unknown . We hypothesized that inhibitory cytokines could facilitate the infection of human alveolar macrophages and monocytes by virulent intracellular lung pathogens . Therefore, we tested the effects of IL-10, TGF-beta, and IL-4 in an in vitro model of human alveolar macrophage and monocyte infection with L . pneumophila . We found that unstimulated alveolar macrophages supported over 100-fold greater L . pneumophila growth than did unstimulated monocytes . IL-10 treatment significantly enhanced L . pneumophila growth in monocytes, and completely reversed the protective effect of IFN-gamma against intracellular L . pneumophila replication . IL-10 had similar but less potent effects on alveolar macrophages . In contrast, TGF-beta and IL-4 had no significant effects on L . pneumophila growth in resting or IFN-gamma-activated monocytes or alveolar macrophages . IL-10 blocked TNF-alpha production by infected cells, but exogenous TNF-alpha did not reverse the activating defect in cells cocultured with IFN-gamma and IL-10 . Finally, L . pneumophila-infected monocytes produced substantially more IL-10 than did infected alveolar macrophages . In summary, IL-10 significantly enhances the growth of L . pneumophila in human monocytes, reverses the protective effect of IFN-gamma, blocks TNF-alpha secretion, and is secreted by infected monocytes and alveolar macrophages . Induction of IL-10 may be a virulence mechanism that promotes intracellular bacterial replication in human legionellosis.

J Biotechnol, 1996 Sep 13, 50(1), 1 - 12
Glucose uptake kinetics of Saccharomyces cerevisiae monitored with a newly developed FIA; Rothen SA et al.; The glucose content of the culture liquid during shift experiments and synchronized cultures of Saccharomyces cerevisiae H1022 (ATCC 32167) was monitored using a greatly improved and highly precise FIA . During shift-up experiments on the dilution rate, an overshoot of the glucose-concentration was observed . The amplitude of the overshoot showed a dependency on the duration of undisturbed cultivation before application of the shift . Mutarotational non-equilibrium was excluded as the cause of the observed overshoot . For the first time glucose measurements of oscillating cultures of Saccharomyces cerevisiae are demonstrated with high accuracy and reproducibility . The data strongly support the proposals by Munch et al . (1992a, b) that faint oscillations in glucose concentration are responsible for the persistence of the synchronization . Analytical subsystems prove to be a powerful tool for investigation of the dynamics of metabolic pathways of microbial organisms . Accurate glucose measurements at low concentrations point out the limits and allow refinements of commonly used models.

J Med Chem, 1996 Sep 13, 39(19), 3842 - 6
Rediscovering an endothelin antagonist (BQ-123): a self-deconvoluting cyclic pentapeptide library; Spatola AF et al.; A "self-deconvoluting" cyclic pentapeptide library, designed to produce 82,944 head-to-tail-linked peptides in 48 vials, has been prepared . The mixture included amino acids found in a recently optimized endothelin antagonist, BQ-123, originally isolated from microbial sources by Banyu investigators . Using a positional scan approach, the most potent of 12 residues at each of the four variable positions uniquely rediscovered the BQ-123 sequence or cyclo(L-Pro-D-Val-L-Leu-D-Trp-D-Asp) . Resynthesis of the four most potent amino acid combinations gave the following values of relative potency: cyclo(L-Pro-D-Val-L-Leu-D-Trp-D-Asp) or BQ-123 = 1.0, cyclo(L-Pro-D-Pro-L-Leu-D-Trp-D-Asp) = 0.0, cyclo(L-Pro-D-Pro-L-Trp-D-Trp-D-Asp) = 0.0, and cyclo(L-Pro-D-Val-L-Trp-D-Trp-D-Asp) = 0.1 . This study reflects the first time that the positional scan approach has been applied to cyclic peptide libraries using a known target . Although no analogs more potent than BQ-123 were discovered, our results provide verification of our synthetic methods for preparing head-to-tail cyclic peptide libraries and also lend support to the use of carefully designed sublibraries for the rapid elucidation of potential leads within a relatively constrained set of peptide macrocycles.

Proc Natl Acad Sci U S A, 1996 Sep 3, 93(18), 9454 - 9
Primordial emergence of the recombination activating gene 1 (RAG1): sequence of the complete shark gene indicates homology to microbial integrases; Bernstein RM et al.; The rearrangement of antibody and T-cell receptor gene segments is indispensable to the vertebrate immune response . All extant jawed vertebrates can rearrange these gene segments . This ability is conferred by the recombination activating genes I and II (RAG I and RAG II) . To elucidate their origin and function, the cDNA encoding RAG I from a member of the most ancient class of extant gnathostomes, the Carcharhine sharks, was characterized . Homology domains identified within shark RAG I prompted sequence comparison analyses that suggested similarity of the RAG I and II genes, respectively, to the integrase family genes and integration host factor genes of the bacterial site-specific recombination system . Thus, the apparent explosive evolution (or "big bang") of the ancestral immune system may have been initiated by a transfer of microbial site-specific recombinases.

Acta Anaesthesiol Sin, 1996 Sep, 34(3), 141 - 9
{Similarity and synergy of trauma and sepsis: role of tumor necrosis factor-alpha and interleukin-6}; Tang GJ; Both trauma and infection cause a rise in body temperature, white blood cell count, acute phase proteins, fluid and sodium retention and negative nitrogen balance . This phenomenon is often described as "acute phase response" or "systemic inflammatory response syndrome" to denote a coordinated systemic response to significant tissue injury and/or microbial invasion . It is generally agreed that the acute phase response is mediated through the interaction of cytokine and neuroendocrine pathways . Tumor Necrosis Factor-alpha (TNF-alpha) and interleukin-6 (IL-6) are two of the major key cytokines involved in the generation of acute phase response . Interleukin-6 are consistently found in septic, trauma and post-operative patients and correlated well with the severity of sepsis or injury . IL-6 is responsible for the fever and metabolic changes in the acute phase . In addition to IL-6, TNF-alpha was proved to be the mediator that orchestrates the hemodynamic and tissue injury in septic shock . TNF-alpha destroys endothelial cells and induces disseminated intravascular coagulation, fluid shift, shock, multiple organ system failure and death . On many clinical occasions, both infection and trauma may happen simultaneously on the same patient . Our study demonstrated that operation on the infected patients would cause a synergistic effect on both TNF-alpha and IL-6 levels . The pulse increase in TNF-alpha and the persistent elevation of IL-6 were responsible for the post-operative unstable clinical condition in the infected patients . Should we block the cytokine signal and inflammatory response that appear to be harmful? Animal studies have shown that the septic shock to endotoxin challenge can be prevented by pretreatment with monoclonal antibody against TNF-alpha . The transcription of TNF-alpha can be blocked with corticosteroid in vivo . The post-operative increase in IL-6 and its related inflammation can be attenuated with corticosteroid, epidural anesthesia and narcotics . However, although blocking the inflammatory response has a beneficial effect of stress free it also eliminates our ability to fight with bacterial infection by lowering our immune response . How to manipulate these cytokines is a question of art more than science.

J Exp Med, 1996 Sep 1, 184(3), 993 - 1001
Identification of a heparin-binding hemagglutinin present in mycobacteria; Menozzi FD et al.; Adherence to mammalian host tissues is an important virulence trait in microbial pathogenesis, yet little is known about the adherence mechanisms of mycobacteria . Here, we show that binding of mycobacteria to epithelial cells but not to macrophages can be specifically inhibited by sulfated carbohydrates . Using heparin-Sepharose chromatography, a 28-kD heparin-binding protein was purified from culture supernatants and cell extracts of Mycobacterium bovis and Mycobacterium tuberculosis . This protein, designated heparin-binding hemagglutinin (HBHA), promotes the agglutination of rabbit erythrocytes, which is specifically inhibited by sulfated carbohydrates . HBHA also induce mycobacterial aggregation, suggesting that it can mediate bacteria-bacteria interactions as well . Hemagglutination, mycobacterial aggregation, as well as attachment to epithelial cells are specifically inhibited in the presence of anti-HBHA antibodies . Immunoelectron microscopy using anti-HBHA monoclonal antibodies revealed that the protein is surface exposed, consistent with a role in adherence . Immunoblot analyses using antigen-specific antibodies indicated that HBHA is different from the fibronectin-binding proteins of the antigen 85 complex and p55, and comparison of the NH2-terminal amino acid sequence of purified HBHA with the protein sequence data bases did not reveal any significant similarity with other known proteins . Sera from tuberculosis patients but not from healthy individuals were found to recognize HBHA, indicating its immunogenicity in humans during mycobacterial infections . Identification of putative mycobacterial adhesins, such as the one described in this report, may provide the basis for the development of new therapeutic and prophylactic strategies against mycobacterial diseases.

J Exp Med, 1996 Sep 1, 184(3), 1045 - 59
Role of the glycocalyx in regulating access of microparticles to apical plasma membranes of intestinal epithelial cells: implications for microbial attachment and oral vaccine targeting; Frey A et al.; Transepithelial transport of antigens and pathogens across the epithelial barrier by M cells may be a prerequisite for induction of mucosal immunity in the intestine . Efficient transport of antigens and pathogens requires adherence to M cell apical surfaces . Coupling of antigen-containing particles to the pentameric binding subunit of cholera toxin (CTB) has been proposed as a means for increasing antigen uptake because the CTB receptor, ganglioside GM1, is a glycolipid present in apical membranes of all intestinal epithelial cells . To test the accessibility of enterocyte and M cell membrane glycolipids to ligands in the size ranges of viruses, bacteria, and particulate mucosal vaccines, we analyzed binding of CTB probes of different sizes to rabbit Peyer's patch epithelium . Soluble CTB-fluorescein isothiocyanate (diameter 6.4 nm) bound to apical membranes of all epithelial cells . CTB coupled to 14 nm colloidal gold (final diameter, 28.8 nm) failed to adhere to enterocytes but did adhere to M cells . CTB-coated, fluorescent microparticles (final diameter, 1.13 microns) failed to adhere to enterocytes or M cells in vivo or to well-differentiated Caco-2 intestinal epithelial cells in vitro . However, these particles bound specifically to GM1 on BALB/c 3T3 fibroblasts in vitro and to undifferentiated Caco-2 cells that lacked brush borders and glycocalyx . Measurements of glycocalyx thickness by electron microscopy suggested that a relatively thin (20 nm) glycocalyx was sufficient to prevent access of 1-micron microparticles to glycolipid receptors . Thus, the barrier function of the intestinal epithelial cell glycocalyx may be important in limiting microbial adherence to membrane glycolipids, and in CTB-mediated targeting of vaccines to M cells and the mucosal immune system.

Vestn Otorinolaringol, 1996 Sep-Oct, (5), 10 - 2
{Malformations of intranasal structures and rhinosinusitis in children}; Garashchenko TI; 240 patients with acute and 233 children with chronic nasal and paranasal sinus disease aged under 14 years have undergone endoscopic examination . It was found that the number of serious developmental defects hindering drainage of the paranasal sinusis was higher in children with rhinogenic orbital complications than in those with acute sinusitis . Chronic affections of the nose and paranasal sinusis in most examinees were accompanied by malformations of the intranasal structures deteriorating mucociliary transport both in nasal cavity and paranasal sinusis . The occurrence of the above and septal defects increased with age . The conclusion is made that defects of the intranasal structures contribute significantly to the onset of acute sinusis (AS) in children, AS transformation into chronic form, emergence of complications along with general and local immunodeficiency, microbial virulence . The findings support the principal conception of sinusitis pathogenesis offered by W . Messerklinger which justifies early functional endoscopic operations in nasal cavity for prevention and treatment of nasal and paranasal diseases.

Plant Mol Biol, 1996 Sep, 31(6), 1163 - 72
Molecular cloning of cDNAs encoding (1-->4)-beta-xylan endohydrolases from the aleurone layer of germinated barley (Hordeum vulgare); Banik M et al.; Heteroxylans are major constituents of cell walls in the graminaceous monocotyledons . Degradation of walls in the starchy endosperm of germinated cereal grains is mediated, in part at least, by the action of (1-->4)-beta-xylan endohydrolases (EC 3.2.1.8) . Complementary DNAs encoding (1-->4)-beta-xylan endohydrolases from the aleurone layer of germinated barley have been isolated and characterized . Southern blot analyses suggest that the enzymes are derived from a family of 3 or 4 genes, and cDNAs corresponding to two of these genes have been sequenced . The amino acid sequence deduced from one cDNA almost exactly matches the amino acid sequence determined previously from the purified enzyme . This enzyme is designated (1-->4)-beta-xylan endohydrolase isoenzyme X-I . The mature enzyme consists of 395 amino acid residues, has a calculated M(r) of ca . 44600 and an isoelectric point of 6.1, and is likely to adopt an (alpha/beta)8 barrel conformation . The amino acid sequence of the barley (1-->4)-beta-xylan endohydrolase encoded by the other cDNA, which is designated isoenzyme X-II, shows ca . 13% sequence divergence compared with isoenzyme X-I . Both enzymes exhibit sequence and structural similarities with microbial xylanases . Expression of the genes in germinated grain appears to be confined largely to the aleurone layer, and no mRNA transcripts could be detected in young vegetative tissues.

J Dairy Sci, 1996 Sep, 79(9), 1647 - 53
Ruminal degradation, amino acid composition, and intestinal digestibility of the residual components of five protein supplements; Maiga HA et al.; Two ruminally cannulated Holstein cows (approximately 202 DIM) were used to determine the in situ degradability of five protein supplements: blood meal, meat and bone meal, corn gluten meal, expeller soybean meal, and solvent extracted soybean meal . Dacron bags containing 4 g of each supplement in duplicate were soaked in water and then incubated in the rumen for 0, 3, 6, 12, 18, and 24 h for 3 d . Four extra sample bags of each supplement were incubated in the rumen for 12 h to determine the in vitro intestinal digestibility and AA analysis of the residues . Protein supplements were also analyzed for their AA content . Ruminal degradability of individual supplements varied . Solvent soybean meal was the most degradable, and blood meal was the least degradable . Specific first-limiting essential AA were isoleucine for blood meal and meat and bone meal, lysine for corn gluten meal, and methionine for the soybean meals . The RUP fraction in solvent-extracted and expeller soybean meals tended to be more intestinally digestible than did the protein in blood meal and meat and bone meal . In general, all protein supplements, except solvent-extracted soybean meal, were high in RUP and had the potential to provide good quality AA to complement microbial AA for production.

J Dairy Sci, 1996 Sep, 79(9), 1627 - 37
Synthesis of microbial protein in ruminally cannulated cows fed alfalfa silage, alfalfa hay, or corn silage; Hristov AN et al.; Six ruminally cannulated cows were used in an experiment with a 3 x 3 Latin square design . Three all forage diets-alfalfa silage, alfalfa hay, or corn silage plus 2.2% urea (DM basis)-were fed for ad libitum intake four times daily . The microbial protein marker 15NH3 and the liquid marker Cr-EDTA were infused continuously into the rumen for 72 and 48 h, respectively; the solid marker, Yb-labeled forage, was dosed into the rumen twice daily for 60 h . Pool sizes of ruminal NAN were determined by emptying the rumen . Proportions of bacterial N formed from NH3 were 57, 46, and 82% for the alfalfa silage, alfalfa hay, and corn silage diets, respectively . For all diets, flows of microbial NAN with the liquid and solid phases were about equal . Although feed NAN in the liquid pool was only 12% of ruminal feed NAN, 30% of feed NAN that escaped the rumen flowed with the liquids . Flow of microbial NAN was highest for corn silage (243 g/d) and lowest for alfalfa hay (212 g/d); microbial NAN represented 50% (alfalfa silage and hay) and 76% (corn silage) of total NAN flow . Proportions of NAN intake that were degraded in the rumen were 61, 56, and 57% for alfalfa silage, alfalfa hay, and corn silage (without urea N), respectively; these values were lower than those reported by the NRC . Total flows of NAN from the rumen were 472, 424, and 321 g/d for the alfalfa silage, alfalfa hay, and corn silage diets, respectively . Use of liquid (Cr-EDTA) and solid (Yb) markers to compute the rate of passage of microbial protein proved to be less variable than regression of 15N enrichment of bacterial NAN over time.

Bull Pan Am Health Organ, 1996 Sep, 30(3), 197 - 205
Microculture in biphasic medium with silicone-coated slides for isolation of mycobacteria; Shibayama H et al.; The study reported here, seeking to develop a simple, practical, sensitive, and inexpensive technique for microbial diagnosis of tuberculosis, used a combination of biphasic media and microculture techniques to augment the sensitivity of traditional culture methods . A total of 540 sputum samples (5 mL each) were obtained from 180 patients with suspected tuberculosis in Mexico City . These samples were treated with Hanks reagent, neutralized with 25% HCl, and centrifuged . In each case the resulting residue was combined with liquid media (Sula medium or a phosphate-buffered control solution) and was inoculated into a bottle containing a solid medium (Lowenstein-Jensen-Holm or Middlebrook) . A silicone-coated slide appropriate for culture of hydrophobic mycobacteria was inserted in each bottle, and the cultures (examined weekly) were incubated at 37 degrees C until the first macroscopic bacterial growth was detected or for up to eight weeks if none was detected . When such growth was detected, or at the end of eight weeks, each slide was withdrawn from the bottle, sterilized, stained by Kinyoun's method, and examined microscopically . Following 2-4 weeks of incubation, macroscopic bacterial growth was detected in 71 bottles and was confirmed by microscopic examination of the corresponding slides . No macroscopic bacterial growth was found in any of the remaining 469 bottles, but microscopic growth was observed on 77 of the slides examined after eight weeks . The authors conclude that this method represents a noteworthy improvement over standard culture methods in terms of bacterial isolation and suggest that its case, economy, and practicality make it suitable for application in developing countries.

Microbiologia, 1996 Sep, 12(3), 425 - 34
Development of methanogenic consortia in fluidized-bed batches using sepiolite of different particle size; Sanchez JM et al.; The addition of support materials, such as sepiolite, to fluidized-bed anaerobic digesters enhances the methane production by increasing the colonization by syntrophic microbiota . However, the efficiency in the methanogenesis depends on the particle size of the support material, the highest level of methane production being obtained by the smaller particle size sepiolite . Because of the porosity and physico-chemical characteristics of these support materials, the anaerobic microbial consortia formed quickly (after one week of incubation) . The predominant methanogenic bacteria present in the active granules, detected both by immunofluorescence using specific antibodies and by scanning electron microscopy, were acetoclastic methanogens, mainly Methanosarcina and Methanosaeta.

J Clin Periodontol, 1996 Sep, 23(9), 816 - 22
The effect of tetracycline fiber therapy on beta-glucuronidase and interleukin-1 beta in crevicular fluid; Lamster IB et al.; Treatment with the tetracycline HCL-containing (Actisite infinity) fiber has been shown to improve clinical measures of periodontitis, as well as reduce the number of sites infected with putative periodontal pathogens . In this study, we examined the effect of the tetracycline fiber on biochemical mediators of the host's inflammatory response in gingival crevicular fluid (GCF) . The total amount of the lysosomal enzyme beta-glucuronidase (beta G), considered a marker of primary granule release from polymorphonuclear leukocytes and interleukin-1 beta, a cytokine with important proinflammatory effects, were examined in GCF . Patients with localized recurrent periodontitis were followed over a 16 week period . Treated teeth (Tx), teeth adjacent to treated teeth (ADJ) and control teeth (Cx) were studied . Following fiber therapy, the Tx teeth displayed statistically significant reductions in mean probing depth, depth of the deepest site and bleeding on probing over the 16 weeks of the trial . Significant reduction in the depth of the deepest site was also seen for the ADJ teeth over 16 weeks . Total beta G in GCF was reduced for the Tx teeth comparing baseline to 16 weeks, but no significant changes were observed for the ADJ or Cx teeth . Prior to treatment, total beta G for the Tx teeth was 211 +/- 49 U (mean +/- standard error), versus 146 +/- 174 U for the ADJ teeth and 121 +/- 33 U for the Cx teeth . 16 weeks treatment, the mean values for these 3 categories of teeth were comparable (Tx = 95 +/- 20 U, ADJ = 93 +/- 42 U and Cx = 103 +/- 29 U) . For the Tx teeth, the maximum reduction in total beta G following therapy occurred at 6 weeks (65%) . Total IL-1 beta was significantly reduced for the Tx teeth at 3 and 6 weeks, but rebounded at 16 weeks . In contrast to what was seen for beta G, the maximum reduction in total IL-1 beta for the Tx teeth was observed at 3 weeks (68%) . These data suggest that host mediators associated with increased risk for active disease are reduced following tetracycline fiber therapy . Future studies will determine the relative importance of a reduced microbial challenge versus a tetracycline-mediated direct modification of the host response to account for the reduction in the host inflammatory response in GCF following tetracycline fiber therapy.

Scand J Gastroenterol, 1996 Sep, 31(9), 868 - 74
Effects of perorally applied endotoxin on colonic mucins of germfree rats; Enss ML et al.; BACKGROUND: The intestinal epithelium, with the potential to restrict luminal noxae from the host, secretes a mucous layer with various protective functions . Microbial colonization of germfree (GF) rats stimulates this mucin-secreting tissue . The present study determined the effect of bacterial lipopolysaccharides (LPS) on this process . METHODS: One, 3, and 5 days after peroral application of 35 micrograms LPS/100 g body weight (from Escherichia coli O55:B5), LPS concentrations were monitored in ingesta, intestinal tissue, and liver . Mucin high molecular weight glycoproteins (HMG), released in response to LPS, were isolated and separated into mucins, i) attached to the colonic epithelium (EM) and ii) mixed to the luminal content (LM), respectively . Subsequently, the binding capacity of both mucin fractions for various lectins and for type-1 pili expressing E . coli was determined . RESULTS: Ingesta and tissue had maximal LPS concentrations on days 3 (jejunum) and 5 (colon) . Maximal EM secretion was found on day 3, release of LM further increased to day 5 . Both mucin fractions had altered glycosylation patterns: augmentation of beta-galactose, alpha-N-acetyl galactosamine, and mannose coincided with a decrease in alpha-fucose . Compared with the controls, attachment of E . coli to EM increased slightly on day 1 only; the binding capacity of LM increased continuously up to day 5 . CONCLUSION: Results suggest that mucins, released in response to LPS, in addition to the epithelial protection, support the gut microbial clearance system.

Eur J Cell Biol, 1996 Sep, 71(1), 99 - 104
Response of germfree rat colonic mucous cells to peroral endotoxin application; Enss ML et al.; During microbial colonization, mucin-releasing goblet cells of germ-free (GF) rats proliferate and upregulate their mucin synthesis, thus improving the intestinal mucus barrier . The present study determined the significance of bacterial membrane constituents for this development . A single dose of lipopolysaccharide (LPS) (35 micrograms/100 g body weight) and lipid A (3.5 micrograms/100 g body weight, respectively), was perorally administered to GF AS/Ztm rats . One, 3 and 5 days later, sections of the proximal and distal colon served for characterization of mucin-secreting goblet cells, released mucins were isolated in parallel . Maximal goblet cell diameters were evidenced at day 3 . LPS generated a maximal goblet cell hyperplasia one day after challenge, lipid A stimulated the goblet cell proliferation continuously up to day 5 . Three days after challenge with one of the stimuli, either, intracellular mucins had shifted significantly to neutral constituents . In addition, mucins, adherent to the colon mucosa and submerged to the luminal content, respectively, then were augmented . At day 5, adherent mucins were similar to the controls, while luminal, soluble constituents had further increased . Histometrical and biochemical methods evidenced a transient, inflammatory response of mucin-secreting cells, followed by an upregulated release of immature mucins.

Infect Control Hosp Epidemiol, 1996 Sep, 17(9), 595 - 604
Epidemiologic typing systems; Maslow J et al.; Microbial strain typing is a useful adjunct to clinical epidemiology . Phenotypic typing systems examine expressed characteristics, whereas genotypic systems, including recent PCR-based systems, examine chromosomal or plasmid DNA . Typing systems have evaluated bacteria, fungi, and viruses successfully . The criteria used to assess the utility of each system include typeability, reproducibility, and discriminatory power.

FEMS Immunol Med Microbiol, 1996 Sep, 15(2-3), 129 - 34
Detection of peptidoglycan and beta-glucan with silkworm larvae plasma test; Tsuchiya M et al.; A method to detect peptidoglycan and (1-->3) beta-D-glucan with silkworm larvae plasma (SLP) derived from the hemolymph of the silkworm, Bombyx mori was developed . SLP contains all of the factors of the pro-phenol oxidase cascade, an important self-defense mechanism of insects . Peptidoglycan or (1-->3)-beta-D-glucan initiates the cascade, in which pro-phenol oxidase is finally activated to phenol oxidase . The phenol oxidase activity was colorimetrically or visually detected with 3,4-dihydroxyphenylalanine as a substrate . SLP displayed high reactivity with peptidoglycan and polysaccharides containing 1,3-beta-glucosidic linkages, but not with endotoxins . SLP is useful for the detection of microbial contamination because peptidoglycan and (1-->3)-beta-D-glucan are cell wall components of bacteria and fungi, respectively.

J Clin Microbiol, 1996 Sep, 34(9), 2180 - 4
Clinical importance of increased sensitivity of BacT/Alert FAN aerobic and anaerobic blood culture bottles; McDonald LC et al.; Two recent multicenter blood culture studies found that BacT/Alert FAN (FAN) bottles (Organon Teknika, Durham, N.C.) had increased yields in detecting bacteremia and fungemia compared with standard BacT/Alert (STD) bottles . Because the clinical importance of this increase in microbial recovery is unknown, we performed a retrospective analysis to determine the frequency with which FAN bottles were the sole means of detecting an episode of bacteremia . There were 1,047 positive blood cultures in which both study bottles were adequately filled and the organism isolated was judged to be the cause of sepsis: 240 (23%) were positive only in FAN bottles and 73 (7%) were positive only in STD bottles . Of a total of 664 episodes of bacteremia, 126 (19%) were identified only by FAN bottles and 43 (7%) were identified only by STD bottles (P < 0.0001) . Episodes detected only by FAN bottles more often were recurrent events (23 of 126, or 18%) than episodes detected only by STD bottles (2 of 43, or 5%) (P < 0.05) and more commonly occurred in patients receiving theoretically effective antibiotic therapy (33 of 126 {26%} versus 4 of 43 {9%}) (P < 0.05) . The medical records for patients with 127 of these episodes (92 FAN bottles only; 35 STD bottles only) were available for review . More than half of both FAN bottle-only (60 of 92, or 65%) and STD bottle-only (20 of 35, or 57%) episodes were judged to be clinically important . We conclude that FAN bottles improve the detection of bacteremia and that the majority of the additional episodes detected are clinically important . The benefits of the greater yield in specific patient populations must be balanced against the higher costs of FAN bottles.

J Am Dent Assoc, 1996 Sep, 127(9), 1359 - 63
Dental considerations in asplenic patients; De Rossi SS et al.; The spleen plays an important role in the body's defense mechanism against microbial infections . However, trauma or diseases sometimes make removal of this important organ necessary, which predisposes patients to certain infections . This increased risk of infection and the underlying reason for the organ's removal both may affect the provision of dental care . This article reviews the structure and function of the spleen, conditions that may require its removal or cause its dysfunction, and provides considerations for dentists who care for asplenic patients.

Acta Cytol, 1996 Sep-Oct, 40(5), 885 - 8
Efficiency of PAPNET in detecting infectious organisms in cervicovaginal smears; Ashfaq R et al.; OBJECTIVE: To evaluate the effectiveness of the PAPNET system in identifying microbial organisms . STUDY DESIGN: Two hundred forty-nine previously screened cervicovaginal smears with a diagnosis of an infectious agent were rescreened by PAPNET system . The images were reviewed on a high-resolution monitor and the presence or absence of coccobacilli, trichomonads, and Candida and herpes organisms was noted . RESULTS: Of 99 cervicovaginal smears with excessive coccobacilli, 16 were missed by PAPNET (percentage of accuracy, 84) . Only 60% of Candida organisms (33 of 55) and 77% of trichomonads (42 of 54) were identified by PAPNET . Herpesvirus was diagnosed correctly on PAPNET in 24 of 41 cases . Two or more infectious agents were present in 14 cases, 5 of which were correctly identified by PAPNET . The accuracy of PAPNET in identifying infectious organism when measured against manual screening was 70%, with a high false negative rate (30%) . CONCLUSION: The PAPNET system identifies coccobacilli, trichomonads and Candida organisms in decreasing order of frequency, missing a high percentage of Candida organisms and trichomonads (40% and 33%, respectively), the most common causative agents in female genital tract infections.

Analyst, 1996 Sep, 121(9), 1203 - 5
Microbial volatile organic compounds--what substances can be found in sick buildings?
Wessen B, Schoeps KO.
There is a relationship between damp buildings and health complaints . Damp conditions in building constructions also favour the growth of micro-organisms . Growth of micro-organisms results in the production of volatile organic compounds, which has been shown to have an impact on Indoor-air monitored via a microbial volatile organic compound (MVOC) analysis . In order to widen the applicability of MVOC analysis, it is necessary to increase this analysis by including more volatiles . By active sampling on Anasorb 747 and selected ion monitoring on a mass spectrometer equipped with a quadropole detector, it is possible to determine these volatiles with sufficient accuracy in indoor air of non-industrial buildings.

Analyst, 1996 Sep, 121(9), 1197 - 201
Measurement methods and strategies for non-infectious microbial components in bioaerosols at the workplace; Eduard W; Exposure to micro-organisms can be measured by different methods . Traditionally, viable methods and light microscopy have been used for detection of micro-organisms . Most viable methods measure micro-organisms that are able to grow in culture, and these methods are also common for the identification of micro-organisms . More recently, non-viable methods have been developed for the measurement of bioaerosol components originating from micro-organisms that are based on microscopic techniques, bioassays, immunoassays and chemical methods . These methods are important for the assessment of exposure to bioaerosols in work environments as non-infectious micro-organisms and microbial components may cause allergic and toxic reactions independent of viability . It is not clear to what extent micro-organisms should be identified because exposure-response data are limited and many different micro-organisms and microbial components may cause similar health effects . Viable methods have also been used in indoor environments for the detection of specific organisms as markers of indoor growth of micro-organisms . At present, the validity of measurement methods can only be assessed by comparative laboratory and field studies because standard materials of microbial bioaerosol components are not available . Systematic errors may occur especially when results obtained by different methods are compared . Differences between laboratories that use the same methods may also occur as quality assurance schemes of analytical methods for bioaerosol components do not exist . Measurement methods may also have poor precision, especially the viable methods . It therefore seems difficult to meet the criteria for accuracy of measurement methods of workplace exposure that have recently been adopted by the CEN . Risk assessment is limited by the lack of generally accepted reference values or guidelines for microbial bioaerosol components . The cost of measurements of exposure to microbial bioaerosol components may be high owing to expensive analyses and highly variable exposure levels . The use of qualitative indicators of microbial growth, recording of health effects, specific immunoglobulin G antibody levels to prevalent species in serum of exposed workers and stratified sampling may help to reduce the costs of exposure assessment . An example of a combined strategy for assessment of health risks from handling mouldy timber is shown.

J Nutr, 1996 Sep, 126(9), 2199 - 208
Arachidonate and docosahexaenoate added to infant formula influence fatty acid composition and subsequent eicosanoid production in neonatal pigs; Huang MC et al.; As natural components of human milk, arachdonic and docosahexaenoic acids play important roles in neonatal development; thus, addition of these fatty acids to infant formula has been suggested . This study examined the effects of supplementation of infant formula with microbial sources of either arachidonate or docosahexaenoate or both on accretion of these fatty acids in phospholipids and subsequent modulation of eicosanoid production in neonatal pig lung . One-day-old piglets received for 25 d one of four diets (n = 5): 1) standard diet containing a fat blend similar to that of conventional infant formula, 2) diet containing 0.9 g/100 g of total fatty acids as arachidonate, 3) diet containing 0.7 g/100 g as docosahexaenoate, or 4) a diet containing both 1.0 g/100 g as arachidonate and 0.8 g/100 g as docosahexaenoate . Arachidonate supplementation resulted in 30-60% significantly greater arachidonate in lung phosphatidylethanolamine and phosphatidylcholine . In phosphatidylinositol, however, arachidonate was resistant to dietary manipulation . Accretion of docosahexaenoate in all three phospholipid classes was 2.6- to 4.7-fold greater in docosahexaenoate-supplemented groups than in the standard group . Inclusion of arachidonate in the diet augmented both prostacyclin and thromboxane production by 25 to 35% . Docosahexaenoate supplementation resulted in the least eicosanoid production among the treatments, and significant suppression was observed for thromboxane when supplementation with both fatty acids was compared with supplementation with arachidonate alone . Thus, dietary arachidonic acid and docosahexaenoic acid at concentrations only slightly greater than those found in human milk tended to exercise opposing effects on lung eicosanoid production.

Clin Immunol Immunopathol, 1996 Sep, 80(3 Pt 1), 325 - 32
Differences in immune functions between human T-lymphotropic virus type I carriers and patients with adult T-cell leukemia/lymphoma; Funai N et al.; A variety of immunologic tests were compared between human T-lymphotropic virus type I (HTLV-I) carriers and patients with adult T-cell leukemia/lymphoma (ATL) . The mitogenic responses of the lymphocytes to concanavalin A and phytohemagglutinin were depressed in the ATL patients but not in the carriers, while the response to pokeweed mitogen in the carriers and ATL patients was depressed compared to the HTLV-I-seronegative controls . A positive tuberculin reaction in the carriers was as frequent as in the controls, but less frequent in the ATL patients . A marked inhibition of the intracellular multiplication of Legionella pneumophila was observed within the monocytes isolated from the carriers, but not in the ATL patients or the normal controls . These results indicate that the ATL patients have severe immunodeficiency, while the HTLV-I carriers have some activation of anti-microbial activity in monocytes although they are somewhat immunosuppressed.

Appl Environ Microbiol, 1996 Sep, 62(9), 3360 - 5
Intraspecies variability of cellular fatty acids among soil and intestinal strains of Desulfovibrio desulfuricans; Dzierzewicz Z et al.; A comparison of cellular fatty acid profiles of Desulfovibrio desulfuricans DSM 642 and 14 wild strains of this species, isolated from two completely different environments, soil and the human intestine, was carried out . All the D . desulfuricans strains grown on lactate and sulfate indicated the presence of considerable amounts of i-C15:0, i-C17:1 and C16:0 . Although differences in the quantities of individual fatty acids present in each strain were clear in the group of soil strains (similarity, 67.6%), in contrast to almost identical fatty acid patterns (similarity, near 100%) in the intestinal strains, the results were variable within the limits acceptable for species demonstration . The higher similarity of the fatty acid profiles of intestinal strains may be a result of the similarity of biocenoses in the human digestive tract . The coefficients of variability of i-C17:1 and i-C15:0 (the major branched-chain fatty acids), as well as clustering of the investigated strains compared with strains described in the literature after plotting percentages of i-C17:1 fatty acid against i-C15:0 fatty acid, confirmed a certain heterogeneity of cellular fatty acid profiles within the group of soil strains, in contrast to almost ideal homogeneity within the group of intestinal isolates . Intestinal strains contained a higher ratio of saturated to unsaturated fatty acids (2.2 +/- 0.14) than did soil strains (1.6 +/- 0.2; in one case, 2.7) . We propose that intestinal D . desulfovibrio bacteria should be assumed to be a highly homogeneous group and should be represented by the strain D . desulfuricans subsp . intestinus in collections of microbial cultures.

J Infect Dis, 1996 Sep, 174(3), 483 - 9
In vitro effect of interleukin-12 on antigen-specific lymphocyte proliferative responses from persons infected with human immunodeficiency virus type 1; Uherova P et al.; The relationship between CD4 lymphocyte count and the in vitro effect of interleukin (IL)-12 on lymphocyte proliferative responses to Candida, tetanus toxoid, and streptokinase antigens was studied in peripheral blood mononuclear cells (PBMC from 30 human immunodeficiency virus (HIV)-infected persons and 10 seronegative controls . IL-12 significantly increased proliferative responses to microbial recall antigens of PBMC from HIV-infected persons with >200 CD4 lymphocytes/mm3 but had little effect on PBMC from patients with more advanced disease . The greatest increase was seen in patients with 200-500 CD4 cells/mm3 . Results of limiting dilution analysis suggested that the increase in antigen-specific lymphocyte proliferation in the presence of IL-12 was due to an increase in the number of responding cells rather than an increase in the extent of proliferation of a fixed number of responder cells.

Infect Immun, 1996 Sep, 64(9), 3800 - 10
Gastric invasion by Trypanosoma cruzi and induction of protective mucosal immune responses; Hoft DF et al.; Trypanosoma cruzi is an intracellular parasite transmitted from a reduviid insect vector to humans by exposure of mucosal surfaces to infected insect excreta . We have used an oral challenge murine model that mimics vector-borne transmission to study T . cruzi mucosal infection . Although gastric secretions have microbicidal activity against most infectious pathogens, we demonstrate that T . cruzi can invade and replicate in the gastric mucosal epithelium . In addition, gastric mucosal invasion appears to be the unique portal of entry for systemic T . cruzi infection after oral challenge . The mucosal immune responses stimulated by T . cruzi gastric infection are protective against a secondary mucosal parasite challenge . This protective mucosal immunity is associated with increased numbers of lymphocytes that secrete parasite-specific immunoglobulin A . Our results document the first example of systemic microbial invasion through gastric mucosa and suggest the feasibility of a mucosal vaccine designed to prevent infection with this important human pathogen.

J Biotechnol, 1996 Aug 20, 49(1-3), 219 - 29
Rapid determination of plasmid copy number; Schmidt T et al.; Plasmid copy number, the number of expression vectors per host cell, is a key variable in recombinant microbial cultivation . Therefore, it would be very helpful, if the plasmid copy number could be determined during the operating process period . A rapid quantification of this important process variable would even open the possibility of its use in process control . However current assays like gel electrophoresis, CsCl-gradient centrifugation, HPLC and other methods are time consuming and difficult to quantify . Indirect methods, like the correlation of copy number with, e.g . the activity of an enzyme, coded on the plasmid, are prone to errors due to the production kinetics, turnover rate and protein denaturation . Here, a method is presented, which enables the plasmid copy number to be determined in less than 30 min . This novel procedure based on plasmid isolation by means of a commercial DNA-isolation kit and quantification by capillary electrophoresis, should allow the copy number to be used in process control.

J Immunol, 1996 Aug 15, 157(4), 1474 - 84
B cells selected for apoptosis in the sheep ileal Peyer's patch have enhanced mutational diversity in the Ig V lambda light chain; Maybaum TA et al.; To investigate the molecular events associated with B cell apoptosis, we analyzed follicular B cells from the large Peyer's patch (PP) in the sheep ileum . Over 95% of B cells generated in the ileal PP are rapidly destroyed by apoptosis . Ig V lambda sequences from apoptotic B cells were compared with sequence from B cells about to emigrate from the PP . The sequences originated from two germline genes, V lambda 5.1 and V lambda 5.3 . Only V lambda 5.1 was rearranged in apoptotic cells, whereas both V lambda 5.1 and V lambda 5.3 were rearranged in B cells about to emigrate . Apoptotic B cells had evidence of increased Ig sequence diversity based on: 1) significantly greater replacement to silent mutation ratios in the complementarity determining regions, 2) the more random distribution of mutations, and 3) the lack of mutational specificity compared with the mutational bias favoring transitions and purines in B cells about to emigrate . Based on this analysis, we propose that the continual proliferation of B cells in the PP follicle might increase their affinity to local Ags . Those Ags that are sequestered in this environment might be expected to stimulate the production of B cells with such high-affinity receptors that ligation would trigger apoptosis . This could account for the deletion of B cells with specificity for self-antigens, selecting ligands as well as gut-derived food and microbial Ags . This process could contribute to the elimination of self-reactive B cells, the expansion of the antibody repertoire, and the generation of oral tolerance.

Proc Natl Acad Sci U S A, 1996 Aug 6, 93(16), 8782 - 6
CAX1, an H+/Ca2+ antiporter from Arabidopsis; Hirschi KD et al.; Reestablishment of the resting state after stimulus-coupled elevations of cytosolic-free Ca2+ requires the rapid removal of Ca2+ from the cytosol of plant cells . Here we describe the isolation of two genes, CAX1 and CAX2, from Arabidopsis thaliana that suppress a mutant of Saccharomyces cerevisiae that has a defect in vacuolar Ca2+ accumulation . Both genes encode polypeptides showing sequence similarities to microbial H+/Ca2+ antiporters . Experiments on vacuolar membrane-enriched vesicles isolated from yeast expressing CAX1 or CAX2 demonstrate that these genes encode high efficiency and low efficiency H+/Ca2+ exchangers, respectively . The properties of the CAX1 gene product indicate that it is the high capacity transporter responsible for maintaining low cytosolic-free Ca2+ concentrations in plant cells by catalyzing pH gradient-energized vacuolar Ca2+ accumulation.

Front Biosci, 1996 Aug 01, 1, e55 - 64
Immunoglobulin therapy in Kawasaki syndrome and RSV prophylaxis; Meissner HC et al.; Kawasaki syndrome and RSV infection are common illnesses that afflict infants and young children . Recent studies demonstrate that intravenous immunoglobulin (IVIG) treatment significantly reduces the clinical severity of these illnesses . The purpose of the current review will be initially to examine mechanisms of disease pathogenesis in KS and RSV infection . This will be followed by a discussion of the potential mechanisms by which IVIG acts in these two illnesses . In both KS and RSV prophylaxis, an important action by which IVIG may work is primarily through toxin or microbial neutralization resulting in the dampening or prevention of the inflammatory response . Other immunomodulatory actions of IVIG are likely to be operative in these diseases and will be an active area of future research.

Berl Munch Tierarztl Wochenschr, 1996 Aug, 109(8), 270 - 2
{A method for specific isolation of verotoxin-producing Escherichia coli colonies}; Timm M et al.; The described colony immunoblot is a special double membrane-agar technology, which permits the specific isolation of VTEC in biological materials decided VT-positive by EIA or PCR . The produced Verotoxin (VT) is detected on the surface of the lower membrane by help of monoclonal antibodies . A direct allocation of the corresponding VT-expressing E . coli-colonies on the upper membrane is possible . So the isolation and further characterisation of potential VTEC is practicable in materials with a high microbial contamination too . This isolation method is available for the examination of VT-positive faeces and foods . In the case of foods it is necessary to work with an enrichment culture.

Appl Microbiol Biotechnol, 1996 Aug, 46(1), 10 - 4
Disposable sensor for biochemical oxygen demand; Yang Z et al.; Disposable-type microbial sensors were prepared for the determination of biochemical oxygen demand (BOD) . The yeast, Trichosporon cutaneum, was directly immobilized on the surface of miniature oxygen electrodes using an ultraviolet crosslinking resin (ENT-3400) . The oxygen electrodes (15 mm x 2 mm x 0.4 mm) were made on silicon substrates using micromachining techniques . They were Clark-type two-electrode systems with-1021 mV applied to the working electrode . Typical response times of the BOD sensors were in the range of 7-20 min . At 20 degrees C, the sensors' dynamic range was from 0 to 18 mg/1 BOD when a glucose/glutamate BOD standard solution was used . The lower limit of detection was 0.2 mg/l BOD . This value was one order of magnitude lower than that of sensors previously reported . The sensors' operational lifetime of 3 days was satisfactory for a disposable type . The sensors' responses were reproducible to within 8% relative standard deviation . The BOD sensors' were applied to untreated and treated waste waters from industrial effluents and municipal sewage . BOD values determined using these sensors correlated well with those determined by the conventional 5-day BOD determination method.

Trends Biotechnol, 1996 Aug, 14(8), 290 - 3
Microbial pathogen genomes--new strategies for identifying therapeutics and vaccine targets; Smith DR; Advances in high-throughput DNA-sequencing techniques have given us the unprecedented ability to rapidly determine the nucleotide sequences of entire bacterial genomes . The application of these methods to the genomes of microbial pathogens, combined with efficient analytical tools and genome-scale approaches for studying gene expression, is revolutionizing our approach to the selection of targets for drug screening and vaccine development . This is bringing new life to this important, but long-neglected, field of research.

Rozhl Chir, 1996 Aug, 75(8), 407 - 10
{Comprehensive treatment of venous ulcer of the leg}; Brychta P et al.; A comprehensive approach to the treatment of venous leg ulcer is described . Its main characteristics are: 1 . Maximum debridement of wound area of the ulcer and suppressing of its microbial contamination 2 . Wound conditioning and its preparation for autografting and especially 3 . Simultaneous operation of varicose veins (stripping of vena saphena and ligature of venae perforates Cocketti) and application of dermoepidermal autograft to the ulcer . The procedure is presented as a case report.

Eur J Oral Sci, 1996 Aug, 104(4 ( Pt 2)), 459 - 69
Restoring oral health . On the rise and fall of dental caries in Iceland; Einarsdottir KG et al.; During the last decade, a continuous decrease in dental caries has been observed among schoolchildren in Iceland . In this paper, various epidemiological studies have been reviewed and summarized to illustrate caries prevalence, and how it has changed during the last decades . Furthermore, an attempt has been made to describe some of the factors involved and their possible effects on caries disease . During this period, sugar consumption increased, especially in the form of sweets and soft drinks . At the same time, the import of toothpaste increased, and preventive measures such as fissure sealants and fluoride rinsing programs were intensified . Other factors likely to have had an impact were changes in treatment philosophy and increased personnel resources . There does not seem to be any single factor responsible for the onset of the caries decline . It rather looks as if this was a multifactorial effect due to a number of different preventive measures . During recent years, a change in treatment philosophy, the evident increase in fluoride toothpaste consumption, and possible changes in the oral microbial flora, together with the use of fluoride varnishes, sealants, and increased manpower, may explain the decline.

Eur J Oral Sci, 1996 Aug, 104(4 ( Pt 1)), 363 - 71
Cellular events concurrent with Porphyromonas gingivalis invasion of oral epithelium in vitro; Sandros J et al.; The aim of the present study was to elucidate events related to receptor function, signal transmission and cytoskeletal rearrangements concurrent with Porphyromonas gingivalis invasion of oral epithelial cells in vitro . Porphyromonas gingivalis strain FDC 381 and the KB cell line (ATCC CCL 17) were used in a previously described antibiotic protection assay . The involvement of a receptor-mediated endocytosis pathway in the internalization process was demonstrated after treatment of the epithelial cells with monodansylcadaverine and ouabain, substances that inhibit formation of coated pits, resulting in reduction in the number of invading P . gingivalis: Treatment of the epithelial cells with the protein kinase (PK) inhibitor staurosporine and the tyrosine-specific PK inhibitor genistein was also found to significantly decrease the number of invading bacteria, suggesting involvement of tyrosine phosphorylation in signal transduction during invasion . This was further supported by the identification of a 43 kD protein acting as a substrate for tyrosine phosphorylation subsequent to the microbial-host cell interaction . Tyrosine phosphorylation of the 43 kD protein was strongly reduced by treatment with PK inhibitors . The decrease in invasion observed after treatment of epithelial cells with colchicine and nocodazole, inhibitors of microtubuli polymerization, suggested that the bacterial-receptor interaction and the phosphotyrosine-dependent intracellular signalling trigger an internalization process involving rearrangements of cytoskeletal microtubuli.

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