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目的探讨内质网应激(ERS)在蛛网膜下腔出血(SAH)后早期脑损伤中的作用机制。方法采用血管穿刺法制作大鼠SAH模型,应用ERS 激动剂衣霉素(Tm)、抑制剂牛磺熊去氧胆酸(TUDCA)以及自噬抑制剂3- 甲基腺嘌呤(3-MA)研究ERS 与自噬在SAH 后早期脑损伤中的作用。在SAH 模型建立后24h对大鼠进行神经功能评估,留取脑组织后分别行分子生物学和免疫组织化学检测。结果SAH后24h ERS水平显著激活,Tm预处理可显著改善SAH 大鼠的神经功能,抑制促凋亡分子caspase-3的表达,减少TUNEL阳性细胞的数量。TUDCA则显著加重SAH 大鼠神经功能障碍并导致神经细胞凋亡。Western blot结果显示,Tm预处理可显著降低自噬标记蛋白Beclin 1表达水平及LC3-Ⅱ/LC3-Ⅰ比值,而TUDCA 具有相反的作用。通过侧脑室内给予3-MA则可显著抑制Tm介导的抗凋亡作用。结论ERS对SAH后早期脑损伤具有神经保护作用,该作用与自噬的激活密切相关。 相似文献
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阳离子型微乳液聚合丙烯酰胺的表征 总被引:10,自引:0,他引:10
自从Hoar[1]和Schulman[2]利用乳化剂、水和油制得均一透明的微乳液以来,微乳液在许多领域中得到广泛应用.Candau[3,4]通过微乳液聚合得到分子量很高(105~106)的纳米级聚合物粒子,且聚合物分子链采取紧密缠绕的构象.Antonietti[5]在对苯乙烯微乳液聚合的研究报道中认为,聚合物分子链是以一种类似于网状交联结构的形态存在的,这些结果表明,通过微乳液聚合所得聚合物可能存在着一些特殊的性质.本文采用阳离子型乳化剂十六烷基三甲基溴化铵(CTAB)和脂肪族醇助乳化剂制备的油包水(W/O)型反相微乳液体系来聚合丙烯酰胺(Am),并与使用相同乳… 相似文献
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Objective To investigate the effect of minocycline on early brain injury (EBI) following subarachnoid hemorrhage(SAH) in rats. Methods SAH was induced by the filament perforation model in male Sprague Dawley rats. SD rats(n=77) were randomly assigned to sham (n=22), SAH+vehicle (n=28), and SAH+minocycline (n=27) groups. Minocycline (135mg/kg) or equal volume of vehicle was administered 1 h after SAH induction. Mortality, neurological scores, brain edema were evaluated 24 h after SAH. Cell apoptosis were examined by TUNEL staining, and the expression of caspase-3 and Bcl-2 was assayed by Western blot at the same time point. Results The mortality was 21.4% in SAH+vehicle group, 18.5% in the SAH+minocycline group, while no death was observed in sham-operated rats; there was no significant difference in mortality between SAH+vehicle and SAH+minocycline groups (P>0.05), but the mortality in these two groups was much higher than that in shamgroup(P<0.05). The water content of brain was significantly increased in the SAH+vehicle group (80.00±0.16)% compared with that in sham group [(79.13±0.08)%, P<0.05]. Minocycline treatment markedly reduced brain water content (79.36±0.07)% compared with that in SAH+vehicle group (P<0.05). Caspase-3 levels were markedly increased in SAH+vehicle group (1.53±0.24) compared with sham group (1.00±0.21). Minocycline treatment significantly reduced caspase-3 levels, compared to SAH+vehicle group (1.11±0.18, P<0.05). A significant decrease in Bcl-2 expression was observed in SAH+vehicle group(0.65±0.03) compared with the sham group (1.00±0.12). The treatment of minocycline upregulated the expression of Bcl-2,compared to SAH+vehicle group (0.93±0.13, P<0.05). TUNEL-positive cells were increased in the cortex of SAH+vehicle rats,compared to sham group [(31.50±3.70)%, P<0.05]. Minocycline treatment significantly reduced the number of TUNEL positive cells, compared to SAH+vehicle group [(14.25±2.50)%, P<0.05]. Conclusion Minocycline may reduce early brain injury after subarachnoid hemorrhage in rats by inhibiting cell apoptosis, which is associated with down-regulation of caspase-3 and up-regulation of Bcl-2. 相似文献
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设计合成了具有光热和NO释放性的抗菌、抗氧化水凝胶。利用Fe3+和戊二醛将聚赖氨酸、单宁酸(TA)交联形成水凝胶,并负载NO供体分子S-亚硝基-N-乙酰基-DL-青霉胺(SNAP)获得兼具光热和NO控释功能的水凝胶(NO-Fex-TA20, x=5, 7, 9)。所合成的Fe9-TA20水凝胶具有良好的光热性能,在1 W/cm2近红外光照射下10 min内温度可达到43.8℃。在可见光和37℃恒温下,NO-Fe9-TA20水凝胶3 h累计释放的NO达到36.48μmol/L。抗菌实验表明,水凝胶对金黄色葡萄球菌具有优异的杀菌活性,杀菌活性大于99.9%;同时,其能够高效清除2,2-联苯基-1-苦基胼基(DPPH)自由基,清除率大于84.3%,抗氧化效果显著。 相似文献