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Selected AbstractsDominant sugar utilizers in sediment of Lake Constance depend on syntrophic cooperation with methanogenic partner organismsENVIRONMENTAL MICROBIOLOGY, Issue 6 2008Nicolai Müller Summary Six strains of novel bacteria were isolated from profundal sediment of Lake Constance, a deep freshwater lake in Germany, by direct dilution of the sediment in mineral agar medium containing a background lawn of the hydrogen-scavenging Methanospirillum hungatei as a syntrophic partner. The numbers of colony-forming units obtained after incubation for more than 2 months were in the same range as those of total bacterial counts determined by DAPI staining (up to 108 cells per millilitre) suggesting that these organisms were dominant members of the community. Identical dilution series in the absence of methanogenic partners yielded numbers that were lower by two to three orders of magnitude. The dominant bacteria were isolated in defined co-culture with M. hungatei, and were further characterized. Growth was slow, with doubling times of 22,28 h at 28°C. Cells were small, 0.5 × 5 ,m in size, Gram-positive, and formed terminal oval spores. At 20°C, glucose was fermented by the co-culture strain BoGlc83 nearly stoichiometrically to 2 mol of acetate and 1 mol of methane plus CO2. At higher temperatures, also lactate and traces of succinate were formed. Anaerobic growth depended strictly on the presence of a hydrogen-scavenging partner organism and was inhibited by bromoethane sulfonate, which together indicate the need for a syntrophic partnership for this process. Strain BoGlc83 grew also aerobically in the absence of a partner organism. All enzymes involved in ATP formation via glycolysis and acetyl CoA were found, most of them at activities equivalent to the physiological substrate turnover rate. This new type of sugar-fermenting bacterium appears be the predominant sugar utilizer in this environment. The results show that syntrophic relationships can play an important role also for the utilization of substrates which otherwise can be degraded in pure culture. [source] Immunotherapy of HIV-infected patients with Gc protein-derived macrophage activating factor (GcMAF)JOURNAL OF MEDICAL VIROLOGY, Issue 1 2009Nobuto Yamamoto Abstract Serum Gc protein (known as vitamin D3 -binding protein) is the precursor for the principal macrophage activating factor (MAF). The MAF precursor activity of serum Gc protein of HIV-infected patients was lost or reduced because Gc protein is deglycosylated by ,- N -acetylgalactosaminidase (Nagalase) secreted from HIV-infected cells. Therefore, macrophages of HIV-infected patients having deglycosylated Gc protein cannot be activated, leading to immunosuppression. Since Nagalase is the intrinsic component of the envelope protein gp120, serum Nagalase activity is the sum of enzyme activities carried by both HIV virions and envelope proteins. These Nagalase carriers were already complexed with anti-HIV immunoglobulin G (IgG) but retained Nagalase activity that is required for infectivity. Stepwise treatment of purified Gc protein with immobilized ,-galactosidase and sialidase generated the most potent macrophage activating factor (termed GcMAF), which produces no side effects in humans. Macrophages activated by administration of 100 ng GcMAF develop a large amount of Fc-receptors as well as an enormous variation of receptors that recognize IgG-bound and unbound HIV virions. Since latently HIV-infected cells are unstable and constantly release HIV virions, the activated macrophages rapidly intercept the released HIV virions to prevent reinfection resulting in exhaustion of infected cells. After less than 18 weekly administrations of 100 ng GcMAF for nonanemic patients, they exhibited low serum Nagalase activities equivalent to healthy controls, indicating eradication of HIV-infection, which was also confirmed by no infectious center formation by provirus inducing agent-treated patient PBMCs. No recurrence occurred and their healthy CD,+,cell counts were maintained for 7 years. J. Med. Virol. 81:16,26, 2009. © 2008 Wiley-Liss, Inc. [source] Analgesic and hepatotoxic effects of Ononis spinosa L.PHYTOTHERAPY RESEARCH, Issue 6 2006Betül Sever Yõlmaz Abstract The present study investigated the analgesic and hepatoprotective activities of a water extract of Ononis spinosa L. (OS) in mice. Analgesic activity was based on the pain thresholds measured with the tail-flick test before administration at 30, 90 and 150 min. The results were analysed with one-way variance analysis. The extract of Ononis spinosa showed analgesic activity equivalent to aspirin at 30 and 90 min and even higher than aspirin with the 50 mg/kg dose. At a dose of 100 mg/kg OS showed an analgesic effect equivalent to aspirin at all time points. The hepatoprotective influence of OS on carbon tetrachloride (CCl4)-induced acute liver toxicity was also studied. The extract had no significant effect on the increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and bilirubin in CCl4 treated animals (p > 0.05). Thus, the results reveal that the extract of OS had no hepatoprotective effect on CCl4 -induced acute liver toxicity. Copyright © 2006 John Wiley & Sons, Ltd. [source] Segmentation induced by intraluminal fatty acid in isolated guinea-pig duodenum and jejunumTHE JOURNAL OF PHYSIOLOGY, Issue 2 2004Rachel M. Gwynne Small intestinal movements depend on the composition of the chyme with mixing predominating at high nutrient levels and propulsion being prevalent at low nutrient levels. The mechanisms coupling nutrients to motility are unknown. We used computer analysis of video recordings of isolated guinea-pig duodenum, jejunum and ileum to examine movements induced by a fatty acid, decanoic acid. Increasing intraluminal pressure past a threshold using control saline consistently evoked propulsive reflexes: lumen-occluding constrictions appeared at the oral end propagating at 20.4 ± 2.4 mm s,1 (mean ±s.d., jejunum) to the anal end before being repeated until the intraluminal pressure was returned to control. Subthreshold pressure increases sometimes evoked a transient series of constrictions appearing at the oral end and propagating anally at 18.4 ± 4.7 mm s,1 (jejunum). At basal pressures, decanoic acid dose-dependently induced motor activity consisting of 40,60 s episodes of constrictions separated by 40,200 s periods of quiescence and lasting up to 2 h. Five contraction patterns were identified within episodes including localized stationary constrictions; constrictions that propagated slowly (5,8 mm s,1) for short distances orally or anally; and constrictions that propagated orally or anally for the length of the preparation at 14,20 mm s,1. Decanoic acid induced motor activity was reversibly abolished by tetrodotoxin (3 ,m), hyoscine (1 ,m) and hexamethonium (100 ,m), but was insensitive to blockade of P2 purinoceptors by PPADS (60 ,m). Thus, decanoic acid induces motor activity equivalent to segmentation in guinea-pig small intestine in vitro and this depends on intrinsic neural pathways. [source] | ||||||||||