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991.
本文通过200例成人颅颈静脉窝的观察与测量,对颈静脉窝的形态、位置及其与颅后窝、面神经管垂直部、鼓环的局部解剖关系进行研究,为临床应用及体质调查提供资料。 相似文献
992.
应用单链构象多态性分析多聚酶链反应EB染色法(PCR-SSCP-EB)对40例肺癌组织标本的P53基因序列5~8外显子突变进行分析,同时应用PCR方法检测上述标本及18例肺良性疾病组织标本中HPV16、18型DNA相关序列,旨在分析二者在肺鳞癌发病中的作用及相互关系,并就肺鳞癌与P53基因结构和功能异常的关系进行初步探讨。 相似文献
993.
建立了小鼠脾脏、胸腺细胞体外转化微量培养系统,确定了最佳实验条件.点蜡法充CO_2,简便易行,效果好.RPMI-1640培养基内补充胎牛血清,其浓度确定为在脾细胞培养为10%,在胸腺细胞培养为20%.脾细胞培养最适细胞密度为2~5×10~6/ml,Con A最适量为2~4μg/培养;胸腺细胞培养细胞最适密度为1×10~7/ml,Con A最适量为2~4μg/培养.两种已知免疫活性的药物在脾细胞培养体系有明确肯定的反应. 相似文献
994.
真皮下血管网岛状皮瓣抗菌力的实验研究 总被引:2,自引:0,他引:2
为研究真皮下血管网薄皮瓣用于感染创面的可行性,在家猪臀部两侧分别形成以旋髂深血管主干分支为蒂的传统岛状皮瓣和远侧50%修薄的真皮下血管网岛状皮瓣。用细菌计数、吖啶橙荧光染色测定白细胞吞噬指数和白细胞内杀菌率,应用激光多普勒、墨汁灌注、透明标本等方法,对两种皮瓣的抗菌力作自身对照研究。结果表明,真皮下血管网岛状皮瓣的抗菌力明显降低,可能与皮瓣修薄后血供减少,白细胞功能相应降低有关。 相似文献
995.
Further studies of the role of Ser-16 in the regulation of the activity of phenylalanine hydroxylase. 总被引:3,自引:1,他引:2 下载免费PDF全文
D Kowlessur X J Yang S Kaufman 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(11):4743-4747
It was previously proposed that the activation of rat liver phenylalanine hydroxylase (EC 1.14.16.1) by cAMP-dependent protein kinase-mediated phosphorylation of Ser-16 is due to the introduction of the negatively charged phosphate group. To explore the validity of this proposal, we have applied site-directed mutagenesis to specifically replace Ser-16 with negatively charged amino acids, glutamic and aspartic; with polar uncharged amino acids, asparagine and glutamine; with the positively charged amino acid lysine; and with the nonpolar hydrophobic amino acid alanine. The wild-type and mutant enzymes were purified to homogeneity, and the importance of Ser-16 in the activation of phenylalanine hydroxylase was examined by comparing the state of activation of the phosphorylated form of the wild-type hydroxylase with that of the mutants. The kinetic studies carried out on the wild-type phosphorylated hydroxylase showed that all the activation could be accounted for by an increase in Vmax with no change in Km for either phenylalanine or the pterin cofactor. Replacement of Ser-16 with a negatively charged residue, glutamate of aspartate, resulted in the activation of the hydroxylase by 2- to 4-fold, whereas replacement with glutamine, asparagine, lysine, or alanine resulted in a much more modest increase. Further, lysolecithin was found to stimulate the phosphorylated hydroxylase and the mutant enzymes S16E and S16D by a factor of 6-7. In contrast, the mutants S16Q, S16N, and S16A all showed the same magnitude of activation as the wild-type with lysolecithin. Therefore, this study demonstrates that activation of the enzyme by phosphorylation of Ser-16 by cAMP-dependent protein kinase is due to the introduction of negative charge(s) and strongly suggests the involvement of electrostatic interaction between the regulatory and catalytic domains of the hydroxylase. 相似文献
996.
997.
The effect of established infection with penicillin-resistant staphylococcus aureus on m'icrbarterial anastomosis was studied in an experimental model. The infection was treated with wound debridement and systemic antibiotics before the surgical procedure. It was found that the anastomotic patency rate of microarte-rial repair was 95.1%. The presence of established infection, if properly treated, should not be a contraindication to microarterial surgery. 相似文献
998.
脐血干细胞的采集及储存 总被引:1,自引:0,他引:1
刘玉英 《中国实用护理杂志》2007,23(2)
人类脐血中含有大量的造血干细胞/祖细胞,现已广泛应用于许多疾病的治疗,特别是针对目前无法解决的医学难题,脐血干细胞的应用前景更是被看好。近年来,随着全国各地脐血库的建立,我院脐血干细胞的采集和储存逐年增多,积累了许多护理经验,现报道如下。 相似文献
999.
1000.
Objective: To study the rapid effect of glucocorticoids (GCs) on NMDA receptor activity in hippocampal neurons in stress and to elucidate its underlying probable membrane mechanisms. Methods: Whole-cell patch-clamp recording was used to assess the effect of stress concentration corticosterone (B) on the responses of cultured hippocampal neurons to glutamate and NMDA (N-methy-D-asparatic acid). To make clear the target of B, intracellular dialysis of B(10μmol/L)through patch pipette and extracellular application of bovine serum albumin-conjugated corticosterone (B-BSA, 10μmol/L)were carried out to observe their influence on peak amplitude of NMDA-evoked current. Results: B had a rapid, reversible and inhibitory effect on peak amplitude of GLU-or NMDA-evoked current in cultured hippoeampal neurons. Furthermore, B-BSA had the inhibitory effect on INMDA as that of B, but intraeeUularly dialyzed B had no significant effect on INMDA. Conclusion: These results suggest that under the condition of stress, GCs may rapidly, negatively regulate excitatory synaptic receptors-glutamate receptors (GluRs), especially NMDA receptor (NMDAR) in central nervous system, which is mediated by rapid membrane mechanisms, but not by classical, genomic mechanisms. 相似文献