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71.
Impact of Plant Functional Group, Plant Species, and Sampling Time on the Composition of nirK-Type Denitrifier Communities in Soil 下载免费PDF全文
Christina Bremer Gesche Braker Diethart Matthies Andreas Reuter Christof Engels Ralf Conrad 《Applied microbiology》2007,73(21):6876-6884
We studied the influence of eight nonleguminous grassland plant species belonging to two functional groups (grasses and forbs) on the composition of soil denitrifier communities in experimental microcosms over two consecutive years. Denitrifier community composition was analyzed by terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified nirK gene fragments coding for the copper-containing nitrite reductase. The impact of experimental factors (plant functional group, plant species, sampling time, and interactions between them) on the structure of soil denitrifier communities (i.e., T-RFLP patterns) was analyzed by canonical correspondence analysis. While the functional group of a plant did not affect nirK-type denitrifier communities, plant species identity did influence their composition. This effect changed with sampling time, indicating community changes due to seasonal conditions and a development of the plants in the microcosms. Differences in total soil nitrogen and carbon, soil pH, and root biomass were observed at the end of the experiment. However, statistical analysis revealed that the plants affected the nirK-type denitrifier community composition directly, e.g., through root exudates. Assignment of abundant T-RFs to cloned nirK sequences from the soil and subsequent phylogenetic analysis indicated a dominance of yet-unknown nirK genotypes and of genes related to nirK from denitrifiers of the order Rhizobiales. In conclusion, individual species of nonleguminous plants directly influenced the composition of denitrifier communities in soil, but environmental conditions had additional significant effects. 相似文献
72.
Koufaki M Detsi A Theodorou E Kiziridi C Calogeropoulou T Vassilopoulos A Kourounakis AP Rekka E Kourounakis PN Gaitanaki C Papazafiri P 《Bioorganic & medicinal chemistry》2004,12(18):4835-4841
Novel hybrids of lipoic acid and trolox connected through triamine spacers as well as analogues in which the lipoic acid was attached at different positions of the chroman moiety of vitamin E through an amide bond, were synthesized and exhibited strong inhibition of the microsomal lipid peroxidation. Moreover, the new molecules, at 1 microM concentration, reduced reperfusion arrhythmias and MDA content on isolated rat heart preparations, with the 2- and 5-subtituted chromans possessing the better cardioprotective activity. 相似文献
73.
Böttcher S Maresch C Granzow H Klupp BG Teifke JP Mettenleiter TC 《Journal of virology》2008,82(12):6009-6016
Herpesviruses specify a ubiquitin-specific protease activity located within their largest tegument protein. Although its biological role is still largely unclear, mutation within the active site abolished deubiquitinating (DUB) activity and decreased virus replication in vitro and in vivo. To further elucidate the role of DUB activity for herpesvirus replication, the conserved active-site cysteine at amino acid position 26 within pUL36 of Pseudorabies virus (PrV) (Suid herpesvirus 1), a neurotropic alphaherpesvirus, was mutated to serine. Whereas one-step growth kinetics of the resulting mutant virus PrV-UL36(C(26)S) were moderately reduced, plaque size was decreased to 62% of that of the wild-type virus. Ultrastructural analysis revealed large accumulations of unenveloped nucleocapsids in the cytoplasm, but incorporation of the tegument protein pUL37 was not abolished. After intranasal infection with PrV-UL36(C(26)S) mice showed survival times two times longer than those of mice infected with wild-type or rescued virus. Thus, the DUB activity is important for PrV replication in vitro and for neuroinvasion in mice. 相似文献
74.
Nonalcoholic fatty liver disease and measures of early brain health in middle‐aged adults: The CARDIA study 下载免费PDF全文
75.
Feng DM Wai JM Kuduk SD Ng C Murphy KL Ransom RW Reiss D Chang RS Harrell CM MacNeil T Tang C Prueksaritanont T Freidinger RM Pettibone DJ Bock MG 《Bioorganic & medicinal chemistry letters》2005,15(9):2385-2388
A novel class of 2,3-diaminopyridine bradykinin B1 receptor antagonists is disclosed. Structure-activity relationship studies (SARs) that led to compounds with significantly improved potency and pharmacokinetic properties relative to the lead compound are described. 相似文献
76.
C. Scott Mahan Maria Walusimbi Denise F. Johnson Christina Lancioni Edwin Charlebois Joyce Baseke Keith A. Chervenak Roy D. Mugerwa Diane V. Havlir Harriet Mayanja-Kizza Christopher C. Whalen W. Henry Boom for the Uganda-Case Western Research Collaboration 《PloS one》2010,5(2)
Background
Both HIV and TB cause a state of heightened immune activation. Immune activation in HIV is associated with progression to AIDS. Prior studies, focusing on persons with advanced HIV, have shown no decline in markers of cellular activation in response to TB therapy alone.Methodology
This prospective cohort study, composed of participants within a larger phase 3 open-label randomized controlled clinical trial, measured the impact of TB treatment on immune activation in persons with non-advanced HIV infection (CD4>350 cells/mm3) and pulmonary TB. HIV load, CD4 count, and markers of immune activation (CD38 and HLA-DR on CD4 and CD8 T cells) were measured prior to starting, during, and for 6 months after completion of standard 6 month anti-tuberculosis (TB) therapy in 38 HIV infected Ugandans with smear and culture confirmed pulmonary TB.Results
Expression of CD38, and co-expression of CD38 and HLA-DR, on CD8 cells declined significantly within 3 months of starting standard TB therapy in the absence of anti-retroviral therapy, and remained suppressed for 6 months after completion of therapy. In contrast, HIV load and CD4 count remained unchanged throughout the study period.Conclusion
TB therapy leads to measurable decreases in immune activation in persons with HIV/TB co-infection and CD4 counts >350 cells/mm3. 相似文献77.
Jinsook Kim Christina Lilliehook Amanda Dudak Johannes Prox Paul Saftig Howard J. Federoff Seung T. Lim 《The Journal of biological chemistry》2010,285(30):22919-22926
Nectin-1 is known to undergo ectodomain shedding by α-secretase and subsequent proteolytic processing by γ-secretase. How secretase-mediated cleavage of nectin-1 is regulated in neuronal cells and how nectin-1 cleavage affects synaptic adhesion is poorly understood. We have investigated α-and γ-secretase-mediated processing of nectin-1 in primary cortical neurons and identified which protease acts as a α-secretase. We report here that NMDA receptor activation, but not stimulation of AMPA or metabotropic glutamate receptors, resulted in robust α- and γ-secretase cleavage of nectin-1 in mature cortical neurons. Cleavage of nectin-1 required influx of Ca2+ through the NMDA receptor, and activation of calmodulin, but was not dependent on calcium/calmodulin-dependent protein kinase II (CaMKII) activation. We found that ADAM10 is the major secretase responsible for nectin-1 ectodomain cleavage in neurons and the brain. These observations suggest that α- and γ-secretase processing of nectin-1 is a Ca2+/calmodulin-regulated event that occurs under conditions of activity-dependent synaptic plasticity and ADAM10 and γ-secretase are responsible for these cleavage events. 相似文献
78.
Marjuki H Alam MI Ehrhardt C Wagner R Planz O Klenk HD Ludwig S Pleschka S 《The Journal of biological chemistry》2006,281(24):16707-16715
79.
Proteome analysis of rat liver mitochondria reveals a possible compensatory response to endotoxic shock 总被引:2,自引:0,他引:2
Miller I Gemeiner M Gesslbauer B Kungl A Piskernik C Haindl S Nürnberger S Bahrami S Redl H Kozlov AV 《FEBS letters》2006,580(5):1257-1262
Organ failure induced by endotoxic shock has recently been associated with affected mitochondrial function. In this study, effects of in vivo lipopolysaccharide-challenge on protein patterns of rat liver mitochondria in treated animals versus controls were studied by two-dimensional electrophoresis (differential image gel electrophoresis). Significant upregulation was found for ATP-synthase alpha chain and superoxide dismutase [Mn]. Our data suggest that endotoxic shock mediated changes in the mitochondrial proteome contribute to a compensatory reaction (adaptation to endotoxic shock) rather than to a mechanism of cell damage. 相似文献
80.