共查询到20条相似文献,搜索用时 625 毫秒
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下面所列4个名词代表了遗传工程操作系统中的4种不同技术方法,在目前生物医学研究领域中出现频率很高.为了使读者不致混淆其概念,兹予以简要说明和解释.
Transgeni(转基因,转基因的)
是一种通过转移外源性基因或DNA片段而改变生物体内遗传物质的遗传工程技术和方法. 相似文献
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《Medical electronics》1984,15(1):136-193
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The frequencies of selected alleles in the ABO, Rh, MNS, Duffy, Kidd, Yt, Scianna, and Colton blood group systems were determined among four indigenous Chinese ethnic populations: Han, Tajik, She, and Yugu. Genotypes were determined by PCR or PCR with sequence specific primers (PCR-SSP). In the Han population, the frequencies of A1, A2, B, and O1 alleles were 0.189, 0.003, 0.170, and 0.638, respectively, and the O2 allele was not identified. Among D+ Hans, the frequencies of C and c alleles were 0.67 and 0.33 and the frequencies of E and e were 0.22 and 0.78, respectively. Among D- Hans, the frequencies of C and c alleles were 0.23 and 0.77 and the frequencies of E and e were 0.04 and 0.96, respectively. The frequencies of M and N alleles were 0.478 and 0.522 among Hans and 0.655 and 0.345 among Tajiks, respectively. The frequencies of Fya and Fyb alleles were 0.94 and 0.06 among Hans and 0.98 and 0.02 among Shes, respectively. The frequencies of Jka and Jkb alleles were 0.49 and 0.51 among Hans and 0.56 and 0.44 among Shes, respectively. The frequency of the Yta allele was 1.00 among Hans. The frequencies of Yta and Ytb alleles were 0.94 and 0.06 among Tajiks, respectively. The frequency of the Sc1 allele was 1.00 in both Han and Tajik ethnic populations. The frequency of the Coa allele was 1.00 in Han, She, and Tajik ethnic populations. 相似文献
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A deficiency in mitochondrial frataxin causes an increased generation of mitochondrial reactive oxygen species (ROS), which may contribute to the cell degenerative features of Friedreich's ataxia. In this work the authors demonstrate mitochondrial iron-sulfur cluster (ISC) defects and mitochondrial heme defects, and suggest how both may contribute to increased mitochondrial ROS in lymphoblasts from human patients. Mutant cells are deficient in the ISC-requiring mitochondrial enzymes aconitase and succinate dehydrogenase, but not in the non-ISC mitochondrial enzyme citrate synthase; also, the mitochondrial iron-sulfur scaffold protein IscU2 co-immunoprecipitates with frataxin in vivo. Presumably as a consequence of the iron-sulfur cluster defect, cytochrome c heme is deficient in mutants, as well as heme-dependent Complex IV. Mitochondrial superoxide is elevated in mutants, which may be a consequence of cytochrome c deficiency. Hydrogen peroxide, glutathione peroxidase activity, and oxidized glutathione (GSSG) are each elevated in mutants, consistent with activation of the glutathione peroxidase pathway. Mutant status blunted the effects of Complex III and IV inhibitors, but not a Complex I inhibitor, on superoxide production. This suggests that heme defects late in the electron transport chain of mutants are responsible for increased mutant superoxide. The impact of ISC and heme defects on ROS production with age are discussed. 相似文献
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Dr. med. Carl R. H. Rabl 《Virchows Archiv : an international journal of pathology》1924,249(1):335-356
Zusammenfassung Kalkablagerung und Wachstum des Knochens bei der Frakturheilung lassen sich durch künstlich herbeigeführten periodischen Wechsel der Blutreaktion fördern, durch Übersäuerung (außer durch solche mit Phosphorsäure) hemmen. Daher dürften die vonH. Straub für den gesunden Organismus nachgewiesenen rhythmischen Schwankungen der Blutreaktion für den normalen Kalkstoffwechsel, für das Knochenwachstum und für den Kalkspiegel im Blut ebenfalls von Bedeutung sein. Unter Berücksichtigung dieser Zusammenhänge ergeben sich neue Gesichtspunkte für die Beurteilung der Rachitis und Tetanie. 相似文献