Hydrogen sulfide induced by nitric oxide mediates ethylene-induced stomatal closure of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Pharmacological, laser scanning confocal microscopic (LSCM), real-time PCR and spectrophotographic approaches are used to study the roles of hydrogen sulfide (H2S) and nitric oxide (NO) in signaling transduction of stomatal movement response to ethylene in Arabidopsis thaliana. In the present study, inhibitors of H2S synthesis were found to block ethylene-induced stomatal closure of Arabidopsis. Treatment with ethylene induced H2S generation and increased L-/D-cysteine desulfhydrase (pyridoxal-phosphate-dep...     

电针对大脑中动脉阻塞大鼠一氧化氮合酶mRNA表达的影响

本课题旨在探讨电针对动物急性脑缺血时神经保护作用的可能机制，由于ＮＯ的作用在脑缺血不同阶段及细胞来源而有所不同，因此，观察了电针对脑缺血后各型ＮＯＳｍＲＮＡ表达的影响，结果表明，针刺可能通过抑制脑缺血后ｎＮＯＳｍＲＮＡ，ｉＮＯＳｍＲＡＮ的过量表达而起到对神经元的保护作用     

Ag/TiO_2/AC光催化氧化NO性能研究

以活性炭(AC)为载体,采用溶胶-凝胶法和浸渍法制备新型光催化剂Ag/TiO_2/AC,利用SEM、XRD、BET和UV-Vis光谱等手段对样品进行了表征,并以模拟烟气中的NO为对象,进行光催化氧化性能测试。结果表明,Ag/TiO_2/AC的比表面积为895.21 m~2/g,且对光响应波长已扩展到可见光区,该催化剂在光催化氧化NO反应中具有优异的活性,NO的氧化率高于60.5%。     

尖镰孢菌细胞色素P45055A1与NO相互作用的荧光光谱法研究

以大肠杆菌为宿主表达了尖镰孢菌细胞色素P450 55A1(CYP450 55A1),并采用荧光光谱法研究了其与NO的相互作用.结果表明:在大肠杆菌(DE3)中成功表达了具有酶活性的CYP55A1.在280 nm波长激发下,NO的加入使CYP55A1的荧光逐渐降低,但随温度的变化差异较小;在413 nm波长激发下,NO的加入使CYP55A1的荧光逐渐升高,但加入NADH后其荧光又恢复到原来的值.     

瑞舒伐他汀对急性脑梗死患者血hsCRP及NO水平的影响

目的观察瑞舒伐他汀对急性脑梗死患者血浆超敏C反应蛋白(hs CRP)及一氧化氮(NO)水平的影响.方法140例脑梗死急性期患者随机分为两组,常规治疗组70例,给予常规抗血小板聚集、改善循环、营养神经治疗;瑞舒伐他汀治疗组70例,在常规治疗组基础上每晚加服瑞舒伐他汀10 mg,均治疗14 d,观察治疗前后hs CRP,NO的变化情况.结果 1)与常规治疗前比较,瑞舒伐他汀治疗后hs CRP显著下降,差异具有统计学意义(P0.05);2)各组在治疗14 d后,瑞舒伐他汀治疗组NO较常规组明显升高,差异具有统计学意义(P0.05);3)治疗前hs CRP与神经功能缺损评分呈正相关(r=0.397,P=0.001);治疗前NO与神经功能缺损评分呈显著负相关(r=-0.365,P=0.006).结论血浆hs CRP,NO与急性脑梗死的严重程度密切相关,瑞舒伐他汀能明显降低急性脑梗死患者血浆hs CRP水平,升高NO水平,瑞舒伐他汀可作为治疗急性脑梗死早期应用药物.     

温莪术油对脂多糖活化巨噬细胞释放一氧化氮的抑制作用

研究温莪术挥发油及其主要有效成分对活化巨噬细胞释放一氧化氮的抑制作用．方法：以脂多糖（LPS）诱导小鼠单核巨噬细胞RAW264．7释放NO，通过Griess法测定培养上清中NO的释放量并计算抑制率，通过MTT法评价细胞毒性．结果：温莪术挥发油在1-10μg·mL^-1浓度范围内对活化的小鼠巨噬细胞释放NO具有明显的抑制作用，并呈现良好的剂量依赖关系．其主要有效成分呋喃二烯、莪术烯、吉马酮与莪术醇对脂多糖诱导的小鼠巨噬细胞释放NO表现出显著的抑制活性，IC50分别为6．5、5．8、9．4、9．9μmol·L^-1,结论：呋喃二烯、吉马酮、莪术烯、莪术醇对活化的小鼠巨噬细胞释放NO具有明显的抑制作用，以上结果可为温莪术油的临床应用提供一定的理论基础和科学依据．     

外源一氧化氮供体SNP对UV-B辐射下红芸豆叶片中SOD,CAT和POD同工酶的影响

以对UV-B敏感的红芸豆为材料,采用一氧化氮的供体硝普钠(SNP)研究15μmol/(m<'2>·S)的UV-B辐射下SNP对植物抗氧化酶的影响.结果表明:红芸豆叶片超氧化物歧化酶、过氧化氢酶和过氧化物酶等抗氧化酶活性的增加,同工酶电泳也显示100 μmolSNP促进SOD,CAT,POD同工酶的表达,特别是诱导一些同工酶条带提前出现,还出现一些单独UV-B处理所没有的条带.说明100μmolSNP可以提高UV-B作用下抗氧化酶的活性,在一定程度上减轻植物遭受UV-B伤害.     

NO与C2H2的热反应的量子化学研究

用ＡＭ１方法研究了ＮＯ与Ｃ２Ｈ２热反应的机理。结果表明，生成ＣＯ与ＨＣＮ和ＣＨ２Ｏ与ＨＣＮ反应的速控步的活化能分别为２００．５９３ｋＪ．ｍｏｌ＾－１和２５２．８４３ｋＪ．ｍｏｌ＾－１。     

Inducible nitric oxide synthase expression is related to angiogenesis,bcl—2 and cell proliferation in hepatocellular carcinoma

In this study,we examined the expression of inducible nitric oxide synthase(iNOS) and vascular endothelial growth factor(VEGF) by immunohistochemical staining in 76 tissue sections collected from bepa-tocellular carcinoma(HCC) patients undergoing hepatectomy.Microvascular density (MVD) was determined by counting endothelial cells immunostained using anti-CD34 antibody.We performed DNA-flow cytometric analyses to elucidate the impact of iNOS and VEGF expression on the cell cycle of HCC.Most of the HCC cells that invaded stroma were markedly immunostained by iNOS antibody.The iNOS stain intensity of the liv-er tissue close to the tumor edge was stronger than that of HCC tissue,and the strongest was the hepatocytes colser to the tumor tissue.However,iNOS expression in 10 normal hepatic samples was undetectable.VEGF positive expression ratio was 84.8% in iNOS positive expression cases,and the ratio was 35.3% in negative cases.There was significant correlation(P=0.000) between iNOS and VEGF expression.Moreover,iNOS expression was significantly associated with bcl-2 and MVD,but without p53 expression.DNA-flow cytometric analyses showed that combined expression of iNOS and VEGF had significant impact on the cell cycle in HCC.PI(Proliferating Index) and SPF(S-phase fraction)in the combined positive expression of iNOS and VEGF group was significantly higher than that in the combined negative group.The present findings suggested that iNOS expression was significantly associated with angiogenesis,bcl-2 and cell proliferation of HCC.