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951.
The rate of proteolysis is an important determinant of the intracellular protein content. Part of the degradation of intracellular
proteins occurs in the lysosomes and is mediated by macroautophagy. In liver, macroautophagy is very active and almost completely
accounts for starvation-induced proteolysis. Factors inhibiting this process include amino acids, cell swelling and insulin.
In the mechanisms controlling macroautophagy, protein phosphorylation plays an important role. Activation of a signal transduction
pathway, ultimately leading to phosphorylation of ribosomal protein S6, accompanies inhibition of macroautophagy. Components
of this pathway may include a heterotrimeric Gi3-protein, phosphatidylinositol 3- kinase and p70S6 kinase. Recent evidence
indicates that lysosomal protein degradation can be selective and occurs via ubiquitin- dependent and -independent pathways.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
952.
953.
F. Vardar-Sukan 《Biotechnology letters》1991,13(2):107-112
The foam collapse and foam formation properties of four different simulated fermentation media were compared in the presence and absence of natural oils. It was found that optimum effective natural oil concentration resulting in optimum foam suppression did not always correspond with the optimum for foam collapse, nor the optimum for maximum foam collapse rate. 相似文献
954.
A method based on the infection of CaCo-2 cells and molecular hybridization with a specific cDNA probe has been developed for the detection of infectious astroviruses in environmental samples. By this procedure wild-type astroviruses have been detected in water from an area where a concurrent gastroenteritis outbreak was reported. 相似文献
955.
956.
Reintroducing the European Beaver to Britain: nostalgic meddling or restoring biodiversity? 总被引:1,自引:0,他引:1
The European Beaver Castor fiber once occurred throughout Europe, but in many countries was exterminated or greatly reduced by over-hunting. In the UK, Beavers were last recorded in Scotland in the sixteenth century. Thirteen countries have carried out reintroduction programmes to restore the range of the Beaver in Europe, We provide a basis for discussing the feasibility and desirability of reintroducing the Beaver to Britain. The basic biology of the Beaver is described, followed by summaries of reintroductions in Europe and an evaluation of their successes and failures. We address the fundamental questions of propagule size, habitat requirements, habitat size and provenance of Beavers to be released, before examining in theory whether reintroducing Beavers to Britain is likely to fulfil UKCINC and IUCN criteria relating to environmental impact, socioeconomics and conservation. We then make suggestions as to how a reintroduction to Britain could proceed. Essential work outstanding includes site assessment and public consultation. The restoration of the Beaver to Britain could be a fitting start to the millennium. 相似文献
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959.
F Velge-Roussel C Verwaerde J M Grzych A Auriault A Capron 《Journal of immunology (Baltimore, Md. : 1950)》1989,142(7):2527-2532
A rat IgE mAb specific for larval Ag (26 kDa, 56 kDa) has been shown to protect rats against Schistosoma mansoni infection. Immunizations of Lou/M rats performed with this IgE (Ab1) induced the production of antiidiotypic antibodies (Ab2). Moreover, after this Ab2 production, anti-antiidiotypic antibodies (Ab3) were revealed. The screening of Ab3 isotypes showed the presence of IgG Ab3 and more interestingly of IgE Ab3, i.e., the same isotype as Ab1. These IgE and IgG antibodies recognized predominantly the 26-kDa Ag and were cytotoxic for schistosomula in the presence of platelets for IgE Ab3 and eosinophils for IgG Ab3. Both IgE and IgG Ab3 conferred by passive transfer protective immunity to infected rats (up to 50%). Thus the immunization with an IgE mAb led in part to the production of Ab3 of the same isotype as Ab1. In conclusion, these results suggest that the isotype selection of the antibodies of the third generation (Ab3) might be influenced by the Ab1. The respective role of the idiotope and isotype of Ab1 in isotype regulation is discussed. 相似文献
960.