排序方式: 共有9条查询结果,搜索用时 15 毫秒
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Neuronal cell killing by the envelope protein of HIV and its prevention by vasoactive intestinal peptide 总被引:38,自引:0,他引:38
D E Brenneman G L Westbrook S P Fitzgerald D L Ennist K L Elkins M R Ruff C B Pert 《Nature》1988,335(6191):639-642
The clinical manifestations of AIDS (acquired immune deficiency syndrome) often include neuropsychiatric and neurological deficits, including early memory loss and progressive dementia. HIV (human immunodeficiency virus), the aetiological agent of AIDS, is probably carried by infected macrophages in the central nervous system. The virus enters cells by binding its envelope glycoprotein gp120 to the CD4 antigen present on brain and immune cells. From the data reported in this paper, we now suggest that the neuronal deficits associated with HIV may not be entirely a result of infectivity, but that gp120 shed from HIV could directly produce the neuropathology as a result of its interference with endogenous neurotrophic substances. It is known that an analogue of a sequence contained in vasoactive intestinal peptide (VIP) occurs in all known sequenced gp120 isolates and that VIP is important for neuronal survival in cell culture. Here we show that purified gp120 from two diverse HIV isolates and a recombinant gp120 from a third isolate were all potent in specifically producing significant neuronal cell death in dissociated hippocampal cultures derived from fetal mice, and that this could be reduced by monoclonal antibodies against the murine CD4 antigen and completely antagonized by VIP. 相似文献
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Haskin LA Wang A Jolliff BL McSween HY Clark BC Des Marais DJ McLennan SM Tosca NJ Hurowitz JA Farmer JD Yen A Squyres SW Arvidson RE Klingelhöfer G Schröder C de Souza PA Ming DW Gellert R Zipfel J Brückner J Bell JF Herkenhoff K Christensen PR Ruff S Blaney D Gorevan S Cabrol NA Crumpler L Grant J Soderblom L 《Nature》2005,436(7047):66-69
Gusev crater was selected as the landing site for the Spirit rover because of the possibility that it once held a lake. Thus one of the rover's tasks was to search for evidence of lake sediments. However, the plains at the landing site were found to be covered by a regolith composed of olivine-rich basaltic rock and windblown 'global' dust. The analyses of three rock interiors exposed by the rock abrasion tool showed that they are similar to one another, consistent with having originated from a common lava flow. Here we report the investigation of soils, rock coatings and rock interiors by the Spirit rover from sol (martian day) 1 to sol 156, from its landing site to the base of the Columbia hills. The physical and chemical characteristics of the materials analysed provide evidence for limited but unequivocal interaction between water and the volcanic rocks of the Gusev plains. This evidence includes the softness of rock interiors that contain anomalously high concentrations of sulphur, chlorine and bromine relative to terrestrial basalts and martian meteorites; sulphur, chlorine and ferric iron enrichments in multilayer coatings on the light-toned rock Mazatzal; high bromine concentration in filled vugs and veins within the plains basalts; positive correlations between magnesium, sulphur and other salt components in trench soils; and decoupling of sulphur, chlorine and bromine concentrations in trench soils compared to Gusev surface soils, indicating chemical mobility and separation. 相似文献
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Christensen PR McSween HY Bandfield JL Ruff SW Rogers AD Hamilton VE Gorelick N Wyatt MB Jakosky BM Kieffer HH Malin MC Moersch JE 《Nature》2005,436(7050):504-509
Compositional mapping of Mars at the 100-metre scale with the Mars Odyssey Thermal Emission Imaging System (THEMIS) has revealed a wide diversity of igneous materials. Volcanic evolution produced compositions from low-silica basalts to high-silica dacite in the Syrtis Major caldera. The existence of dacite demonstrates that highly evolved lavas have been produced, at least locally, by magma evolution through fractional crystallization. Olivine basalts are observed on crater floors and in layers exposed in canyon walls up to 4.5 km beneath the surface. This vertical distribution suggests that olivine-rich lavas were emplaced at various times throughout the formation of the upper crust, with their growing inventory suggesting that such ultramafic (picritic) basalts may be relatively common. Quartz-bearing granitoid rocks have also been discovered, demonstrating that extreme differentiation has occurred. These observations show that the martian crust, while dominated by basalt, contains a diversity of igneous materials whose range in composition from picritic basalts to granitoids rivals that found on the Earth. 相似文献
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Genetics of gene expression surveyed in maize,mouse and man 总被引:111,自引:0,他引:111
Schadt EE Monks SA Drake TA Lusis AJ Che N Colinayo V Ruff TG Milligan SB Lamb JR Cavet G Linsley PS Mao M Stoughton RB Friend SH 《Nature》2003,422(6929):297-302
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J L Parrot F Dray G Allouche M C Santais C Foussard F Dubois F Ruff 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1976,282(13):1289-1292
In guinea pigs actively sensitized with ovalbumin and shocked, we have measured blood histamine and histaminase, pulmonary content in cycli AMP and prostaglandins (PG) E1, E2 and F2alpha. In pulmonary efferent blood, both PGE and PGF are increased. In lung tissue, only PGF2alpha, which are bronchoconstructive mediators, are increased. Th increased level in PG seems to have two origins: first a specific increase, then an increased synthesis secondary to histamine release. 相似文献
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Ecdysteroid hormone action 总被引:1,自引:0,他引:1
Klaus-Dieter Spindler C. Hönl Ch. Tremmel S. Braun H. Ruff M. Spindler-Barth 《Cellular and molecular life sciences : CMLS》2009,66(24):3837-3850
Several reviews devoted to various aspects of ecdysone research have been published during the last few years. Therefore,
this article concentrates mainly on the considerable progress in ecdysone research observed recently, and will cover the results
obtained during the last 2 years. The main emphasis is put on the molecular mode of ecdysteroid receptor-mediated hormone
action. Two examples of interaction with other hormonal signalling pathways are described, namely crosstalk with juvenile
hormone and insulin. Some selected, recently investigated examples of the multitude of hormonal responses are described. Finally,
ecological aspects and some practical applications are discussed. 相似文献
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