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排序方式: 共有437条查询结果,搜索用时 216 毫秒
91.
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The Rev axis of HIV autoregulation is one of two critical viral regulatory pathways required for expression of viral genomic and mRNA and for replication. Consequently it is an attractive therapeutic target. Previous studies have investigated the anti-HIV efficacy of targeting to the RRE (the viral RNA target sequence of the Rev axis) a trans-dominant negative inhibitor mutant Rev, M10. In this study we have fused a portion of the influenza virus NS1 protein (which normally inhibits polyA(+) mRNA transport and splicing) to the Rev M10 gene while deleting the NS1 poly(A) binding region. The resulting chimera demonstrates specific and enhanced inhibition of viral-RRE-containing RNA expression. 相似文献
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Hari C. Sharma Abdul Rashid War Mandeep Pathania Suraj P Sharma S. MD. Akbar Rajendra S Munghate 《Arthropod-Plant Interactions》2016,10(2):171-181
Global atmospheric concentration of CO2 is likely to increase from 350 to 750 ppm over the next 100 years. The present studies were undertaken to understand the effects of elevated CO2 on enzymatic activity and secondary metabolites in chickpea in relation to expression of resistance to pod borer, Helicoverpa armigera. Fifteen-day-old chickpea plants [ICCL 86111—resistant and JG 11—commercial cultivar] grown in the greenhouse were transferred to open-top chambers (OTC) and kept under 350, 550 and 750 ppm of CO2. Twenty neonates of H. armigera were released on each plant at 7 days after shifting the pots to the OTCs. Un-infested plants were maintained as controls. After 7 days of infestation, the activities of defensive enzymes [peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL)] and amounts of total phenols and condensed tannins increased with an increase in CO2 concentration in chickpea. The nitrogen balance index was greater in plants kept at 350 ppm CO2 than in plants kept under ambient conditions. The H. armigera-infested plants had higher H2O2 content; amounts of oxalic and malic acids were greater at 750 ppm CO2 than at 350 ppm CO2. Plant damage was greater at 350 ppm than at 550 and 750 ppm CO2. This information will be useful for understanding effects of increased levels of CO2 on expression of resistance to insect pests to develop strategies to mitigate the effects of climate change. 相似文献
96.
Human T lymphocytes expressing the C3b/C4b complement receptor type one (CR1, CD35) belong to Fc gamma receptor-positive CD4-positive T cells 总被引:1,自引:0,他引:1
J H Cohen J P Aubry J P Revillard J Banchereau M D Kazatchkine 《Cellular immunology》1989,121(2):383-390
The phenotypic characteristics of human T lymphocytes expressing the C3b/C4b complement receptor type one (CR1, CD35) were investigated using dual-color surface immunofluorescence and cytofluorometric analysis of stained peripheral blood mononuclear cells (PBMC) from normal individuals. Two to ten percent of PBMC coexpressed CR1 and the CD5, CD2, or CD3 antigen. CR1 was detected on a subset of CD4+ T lymphocytes but not on CD8+ or on Leu-7+ lymphocytes. Costaining for CR1 and for the CD4 subpopulation markers anti-Leu-8, TQ1, OKT17, 2H4, and 4B4 indicated that CR1 on lymphocytes may be coexpressed with any of these phenotypic determinants. All CR1+ lymphocytes expressed Fc gamma receptors (Fc gamma Rs) as assessed by their ability to bind biotinylated dimeric human IgG. The expression of CR1 was increased in mixed lymphocyte reaction with kinetics similar to those of HLA-DR antigen expression. Coexpression of CR1 and Fc gamma R+ may provide a subset of CD4+ lymphocytes with an enhanced ability to bind and respond to C3-bearing complexes of IgG and antigen. 相似文献
97.
Summary Coexistence of peptides in the small intensely fluorescent cells was demonstrated by immunocytochemistry for met-enkephalin-Arg-Gly-Leu, vasoactive intestinal polypeptide, somatostatin, neuropeptide Y and dynorphin. In the extreme example, a single cell was immunoreactive to all 5 peptides examined. Four peptides coexisted in 8% and three peptides in 13% of SIF cells. In 10% of SIF cells no peptide immunoreactivity could be detected. The most prevalent peptide was met-enkephalin (in 46% of cells), then vasoactive intestinal polypeptide (45%), somatostatin (39%), neuropeptide Y (31%) and dynorphin (24%). Met-enkephalin and vasoactive intestinal polypeptide coexisted most commonly (25%). 相似文献
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Early and late passage C-6 glial cell growth: Similarities with primary glial cells in culture 总被引:10,自引:0,他引:10
Dimitra Mangoura MD Ph.D Nikos Sakellaridis M.D Ph.D. Jackeline Jones Antonia Vernadakis 《Neurochemical research》1989,14(10):941-947
Earlier studies in our laboratory have shown that C-6 glial cells in culture exhibit astrocytic properties with increasing cell passage. In this study, we tested the responsiveness of early and late passage C-6 glial cells to various cultures conditions: culture substrata (collagen, poly-L-lysine, plastic), or supplements for the culture medium, DMEM, [fetal calf, or heat inactivated (HI) serum, or media conditioned from mouse neuroblastoma cells (NBCM) or primary chick embryo cultured neurons (NCM)]. Glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP), astrocytic and oligodendrocytic glial markers, were used. Cell numer and protein content increased exponentially with days in culture regardless of the type of the substratum or cell passage. Differences in cell morphology among the three types of substratum were also reflected on GS activity, which rose by three-fold on culture day 3 for cells grown on collagen; thereafter, GS profiles were similar for all substrata. This early rise in GS is interpreted to reflect differential cell adhesion processes on the substrata; specifically, cell adhesion on the collagen stimulated differentiation into astrocytic phenotype.Analogous to immature glia cells in primary cultures, early passage C-6 glial cells responded to neuronal factors supplied either from NCM or NBCM by expressing reduced GS activity, the astrocytic marker and enhanced CNP activity, the oligodendrocytic marker. Thus, early passage cells can be induced to express either astrocytic or oligodendrocytic phenotype. In accordance with our previous reports on primary glial cells, late passage C-6 cells exhibit their usual astrocytic behavior, responding to serum factors with GS activity. Moreover, whereas NCM or NBCM alone markedly lowered GS activity, a combination with serum restored activity. The present findings confirm our previous observations and further establish the C-6 glial cells as a reliable model to study immature glia.Special issue dedicated to Dr. Paola S. Timiras. 相似文献
100.
M Laude-Sharp N Haeffner-Cavaillon M Caroff F Lantreibecq C Pusineri M D Kazatchkine 《Cytokine》1990,2(4):253-258
In this study we compared the interleukin 1 (IL 1)-inducing capacity and the reactivity in the Limulus amoebocyte assay (LAL) of purified lipopolysaccharides (LPSs) from various bacterial strains. LPSs differed greatly in their capacities (on a weight basis) to induce IL 1 release from serum-free cultured human monocytes. LPS species that induced high levels of IL 1 release from human monocytes exhibited a high thiobarbiturate-reactive 2-keto-3-deoxy-octonic acid (KDO) content. No relationship was found between the IL 1-inducing activity and the LAL reactivity of purified LPSs. Filtration experiments in which membranes of decreasing size-exclusion limits were used demonstrated that molecular species of LPS with an apparent Mr below 3,000 may induce IL 1, whereas only species with an apparent Mr above 8,000 are recognized in the LAL assay. The latter observation suggests that the reaction with LAL requires an aggregated form of LPS. These results indicate that biologically active LPS species can cross dialysis membranes in vivo although no LAL reactive material is detected in the blood compartment. The Limulus assay is an insufficient criterion for the absence of LPS in biological fluids. 相似文献