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Embryotoxic effects of 1,2-dibromoethane (DBE), a compound still widely used in industry, have been analyzed using chick embryos in ovo. Administration on embryonic days (ED) 3,4 or 5 induced dose-dependent embryotoxicity, manifested namely as the early embryonic death. A serious disturbance of the vascular system represented probably the main cause of strong embryolethality and growth retardation in the group of survivors. Amniotic bands in the parietal region and defects of brain and aorta prevailed in the malformation spectrum registered on ED 10. The local character of early induced changes suggests a direct effect of DBE itself in the embryotoxic action. This process is probably accomplished through interaction with lipids in cell membranes owing to the hydrophobic character of DBE molecules. The results, however, did not exclude an involvement of reactive metabolites in final embryotoxicity via the formation of DNA-adducts. In any case, a decreasing embryotoxicity of DBE with the age of treated embryos documented that the onset of liver function, assumed to occur on ED 5, did not increase the efficacy of DBE bioactivation. Our results confirmed the short-term embryotoxic properties of DBE reported in rat embryonic cultures. In addition, the in ovo system enabled us to reveal also long-term consequences represented namely by the formation of amniotic bands, not detectable in studies in vitro. The results obtained with the chick embryo in ovo confirmed the suitability of this system for embryotoxicity testing.  相似文献
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Collagen types I and III were isolated from osteoarthrotic cartilage. Immunofluorescence study has shown that these two collagen types are present in the deep layers of cartilage. Additional staining for fibronectin revealed the presence of the cell-adhesive protein in osteoarthrotic cartilage. Neither collagen type I and type III nor fibronectin were found in control cartilage. A passive haemagglutination assay determined anticollagen antibodies (against types I, II and III) in sera of some osteoarthrotic patients.  相似文献
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The fatty acid (FA) composition of fresh mycelia of anaerobic rumen fungi was determined. The fatty acids methyl esters (FAME) of six strains belonging to four genera (Neocallimastix, Caecomyces, Orpinomyces, Anaeromyces) and one unknown strain were analyzed by gas chromatography. All studied fungi possess the same FAs but differences were found in their relative concentrations. The FA profile of anaerobic fungi comprises carbon chains of length ranging from 12 to 24; the most common fatty acids were stearic (C(18:0)), arachidic (C(20:0)), heneicosanoic (C(21:0)), behenic (C(22:0)), tricosanoic (C(23:0)) and lignoceric (C(24:0)) with relative amount representing >4% of total FA. Significant differences were determined for heptadecanoic, oleic, behenic and tricosanoic acids. Rumen anaerobic fungi can contain very long chain fatty acids; we found unsaturated fatty acids including cis-11-eicosenoic (C(20:1)), cis-11,14-eicosadienoic (C(20:2)), erucic (C(22:1n9)), cis-13,16-docosadienoic (C(22:2)) and nervonic (C(24:1)) acids in very small amounts but their presence seems to be unique for anaerobic fungi.  相似文献
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