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91.
92.
P G Geer B C Wang G Flora-Ginter R J Leadley K L Goetz 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1988,187(3):327-334
An increase in atrial pressure has been shown to cause an increase in the concentration of atrial peptides (atriopeptin) in plasma. We therefore hypothesized that a reduction in atrial pressure would decrease the concentration of atriopeptin in plasma. In formulating this hypothesis we assumed that changes in the concentration of other circulating hormones or changes in cardiac nerve activity during hemorrhage would not affect the secretion of atriopeptin. To test the hypothesis, we bled sham-operated conscious dogs at a rate of 0.8 ml.kg-1.min-1 to decrease right and left atrial pressures. Hemorrhage was continued until a total of 30 ml of blood per kilogram body weight had been removed. Identical experiments were performed on conscious cardiac-denervated dogs. The concentration of plasma atriopeptin was decreased in each group of dogs after 10 ml of blood per kilogram of body weight had been removed, but the decrease achieved statistical significance only in the cardiac-denervated dogs. Further hemorrhage, however, produced no further decreases in circulating atriopeptin in either group even though atrial pressures continued to decline as more blood was removed. A comparison of the atriopeptin response to hemorrhage revealed no significant difference between the sham-operated and cardiac-denervated dogs, thus providing no evidence for a specific effect of cardiac nerves on atriopeptin secretion during hemorrhage. Our results demonstrate that the relationship between atrial pressure and plasma atriopeptin that has been observed repeatedly during atrial stretch is not evident during relatively slow, prolonged hemorrhage. There is, however, a small decline in circulating atriopeptin during the initial stage of hemorrhage that could be of biological significance. 相似文献
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Double-stranded DNA sequencing with T7 polymerase 总被引:11,自引:0,他引:11
Y Wang 《BioTechniques》1988,6(9):843-845
95.
The gene encoding human coagulation Factor V (FV), one of the cofactors in the blood clotting process, has been mapped to chromosome 1 by both Southern hybridization to DNA from human-hamster somatic cell hybrids and in situ hybridization. The whole plasmid pUC3A containing a 1.5-kb cDNA sequence for FV was 32P-labeled for Southern analysis and 3H-labeled for in situ hybridization to metaphase chromosomes. The results localized the FV gene to the region of 1q21-25. 相似文献
96.
我国浙江与日本和我国台湾森林植物区系的联系 总被引:6,自引:0,他引:6
作者在“试论浙江省森林植物区系”一文中对我国浙江与日本和我国台湾森林植物区系的联系已作了扼要的说明,本文就是在此基础上作更详尽的论述。浙江省东濒大海,隔海相望,东北方向有日本,其本部岛屿的南端为九州,和浙江北部的纬度相近,具有亚热带气候特征,出现了和浙江相类似的常绿阔叶林和竹林,九 相似文献
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Alternate use of divergent forms of an ancient exon in the fructose-1,6-bisphosphate aldolase gene of Drosophila melanogaster. 下载免费PDF全文
The fructose-1,6-bisphosphate aldolase gene of Drosophila melanogaster contains three divergent copies of an evolutionarily conserved 3' exon. Two mRNAs encoding aldolase contain three exons and differ only in the poly(A) site. The first exon is small and noncoding. The second encodes the first 332 amino acids, which form the catalytic domain, and is homologous to exons 2 through 8 of vertebrates. The third exon encodes the last 29 amino acids, thought to control substrate specificity, and is homologous to vertebrate exon 9. A third mRNA substitutes a different 3' exon (4a) for exon 3 and encodes a protein very similar to aldolase. A fourth mRNA begins at a different promoter and shares the second exon with the aldolase messages. However, two exons, 3a and 4a, together substitute for exon 3. Like exon 4a, exon 3a is homologous to terminal aldolase exons. The exon 3a-4a junction is such that exon 4a would be translated in a frame different from that which would produce a protein with similarity to aldolase. The putative proteins encoded by the third and fourth mRNAs are likely to be aldolases with altered substrate specificities, illustrating alternate use of duplicated and diverged exons as an evolutionary mechanism for adaptation of enzymatic activities. 相似文献