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641.
H. F. Stähelin 《Cellular and molecular life sciences : CMLS》1996,52(1):5-13
The immunosuppressant cyclosporin A (Sandimmune®) has become the first line treatment for preventing rejection of transplanted organs and for certain, autoimmune diseases. The discovery of that drug and its preclinical development are described, and it is shown that most earlier accounts of the history of this compound are, in important respects, incorrect and misleading. 相似文献
642.
B. Schär 《Cellular and molecular life sciences : CMLS》1967,23(9):716-717
Summary Embryonic chick bones were cultured in vitro in the presence of progesterone and of a series of progesterone metabolites. It was found that only 5-pregnane-3,20-dione, 3-hydroxy-5-pregnane-20-one, and 4-pregnene-20-ol-3-one influence the growth of bones in vitro in a manner similar to progesterone. All other investigated progesterone metabolites exert either a different or no demonstrable action on bone growth. 相似文献
643.
644.
M. Vašák Ch E. McClelland H. A. O. Hill J. H. R. Kägi 《Cellular and molecular life sciences : CMLS》1985,41(1):30-34
Summary pKa-Values of lysine residues of mammalian metallothionein were determined by chemical titration measurements of -CH2 lysine resonances in the1H-NMR spectra. They are about 0.5 pH-unit higher than the average pKa-value of a metal-free derivative, suggesting interaction of the positively charged residues with the two three-fold negatively charged metal-thiolate clusters of the metal-containing form. Deprotonation of the lysines leads to circular dichroism changes attributable to an electrostatically induced structural transition of the protein.To whom correspondence concerning this paper should be addressed. 相似文献
645.
G. Pallavicini A. Bardoni A. Profumo A. A. Castellani P. Schiatti A. Glässer 《Cellular and molecular life sciences : CMLS》1984,40(4):371-372
Summary Oral administration to fasted rats of absolute ethanol produces extensive necrotic lesions of gastric mucosa as well as a massive leakage of proteins and mucus glycoproteins into gastric lumen. When the new synthetic prostaglandin MDL 646, belonging to the PGE1 series, is administered intragastrically (2 or 10 g/kg) 30 min before ethanol administration, a significant protection of rat gastric mucosa against alcohol injury is observed.This work was supported in part by a contribution from Ministero della Pubblica Istruzione (MPI), Rome, Italy. 相似文献
646.
647.
Summary The differences in responses of Tb, Tf and
both to intrahypothalamic and i.v. administration of NA were measured both at noon and at midnight in the pigeon. Although the Tb and
were at a higher level in the daytime, no differences in the magnitude of the fall in
and Tb were obtained after either intrahypothalamic or i.v. injections of NA, whether it was measured during the day or at night. The only marked difference was the more prominent vasodilatation in the daytime after both routes of injection. 相似文献
648.
Freshwater gastropods (Basommatophora and Prosobranchia) harbor a variety of mating systems. In particular, apomictic parthenogenesis in prosobranchs and self-fertilization in the hermaphrodite pulmonates may be viable alternatives to outcrossing sexuality in a number of species. The coexistence of different mating systems in extant populations provides opportunities to examine the forces directing their evolution. We review the models analyzing and predicting genetic variability in subdivided populations, with an emphasis on the effects of inbreeding. Population genetic data on freshwater pulmonates are examined in the context of selfing rates and the loss of variability under selfing. Furthermore, the genetic and demographic factors thought to influence mating system evolution are considered, and we highlight the different approaches available to estimate mating system parameters, in particular the selfing rate. Recent population biological studies on polyploid species (Bulinus truncatus, Ancylus fluviatilis) indicate that selfing is the predominant mating system. These studies have contributed to a deeper understanding of conceptual issues in the evolution of selfing rates. Throughout, we emphasize the need for further carefully designed studies. 相似文献
649.
650.
Specificity in Toll-like receptor signalling through distinct effector functions of TRAF3 and TRAF6 总被引:1,自引:0,他引:1
Häcker H Redecke V Blagoev B Kratchmarova I Hsu LC Wang GG Kamps MP Raz E Wagner H Häcker G Mann M Karin M 《Nature》2006,439(7073):204-207
Toll-like receptors (TLRs) are activated by pathogen-associated molecular patterns to induce innate immune responses and production of pro-inflammatory cytokines, interferons and anti-inflammatory cytokines. TLRs activate downstream effectors through adaptors that contain Toll/interleukin-1 receptor (TIR) domains, but the mechanisms accounting for diversification of TLR effector functions are unclear. To dissect biochemically TLR signalling, we established a system for isolating signalling complexes assembled by dimerized adaptors. Using MyD88 as a prototypical adaptor, we identified TNF receptor-associated factor 3 (TRAF3) as a new component of TIR signalling complexes that is recruited along with TRAF6. Using myeloid cells from TRAF3- and TRAF6-deficient mice, we show that TRAF3 is essential for the induction of type I interferons (IFN) and the anti-inflammatory cytokine interleukin-10 (IL-10), but is dispensable for expression of pro-inflammatory cytokines. In fact, TRAF3-deficient cells overproduce pro-inflammatory cytokines owing to defective IL-10 production. Despite their structural similarity, the functions of TRAF3 and TRAF6 are largely distinct. TRAF3 is also recruited to the adaptor TRIF (Toll/IL-1 receptor domain-containing adaptor-inducing IFN-beta) and is required for marshalling the protein kinase TBK1 (also called NAK) into TIR signalling complexes, thereby explaining its unique role in activation of the IFN response. 相似文献