SH3GL2在无病灶性难治性癫(癎)患者脑组织中的表达

目的:分析无病灶性难治性癫患者脑组织中SH3GL2 mRNA与蛋白的表达水平,探讨可能的发病机制。方法:运用逆转录-聚合酶链式反应(RT-PCR)和Westernblot分别检测10例无病灶性难治性癫患者及10例对照组脑组织SH3GL2 mRNA及蛋白的表达。结果:RT-PCR检测显示,无病灶性难治性癫患者脑组织SH3GL2 mRNA表达的相对水平为(102.23±54.68),对照组为(44.59±17.12),两者差异有显著统计学意义(P<0.01);Westernblot分析表明,无病灶性难治性癫患者脑组织的SH3GL2蛋白表达相对水平(229.54±89.82)高于对照组(143.88±59.69),两者差异也有显著统计学意义(P<0.05)。结论:SH3GL2 mRNA与蛋白表达水平在无病灶性难治性癫患者脑组织中明显增强,提示表达于中枢神经系统的SH3GL2可能在人类难治性癫的发病机制中起了一定作用。     

胃癌第一站淋巴结窦组织细胞增生生发中心增生对胃癌预后的影响

目的 :研究胃癌第一站淋巴结窦组织细胞增生 (SH)、生发中心增生 (GCH)对胃癌第一站淋巴结转移及预后的影响。方法 :将SH、GCH分别分为 - ,+ ,+ +三级 ,分析SH ,GCH对胃癌第一淋巴结转移的影响 ,比较其 5年生存率。结果 :①SH -患者淋巴结转移率明显比SH + ,SH + +高 (P <0 .0 0 5 ) ;5年生存率随SH分级数升高而升高 (P <0 .0 0 5 ) ;②GCH -患者淋巴结转移率明显比GCH + ,GCH+ +高 (P <0 .0 0 5 ) ;5年生存率随GCH分级数升高而升高 (P <0 .0 1)。结论 :SH ,GCH患者胃癌第一站淋巴结转移率较低 ;SH ,GCH分级数越高预后越好 ;SH ,GCH可作为预测胃癌预后的指标之一。     

VEGF参与CoCl2预处理对神经细胞缺氧损伤的保护作用

目的：探讨CoCl2对体外培养分化SH-SY5Y细胞的缺氧损伤保护作用及缺氧诱导基因产物VEGF在其中的作用。方法：分化的SH-SY5Y细胞随机分为对照组、化学缺氧预处理组（预处理组,细胞先用50μM CoCl2预处理3 h,换液后常氧培养1 h,然后在2%的低氧孵箱内缺氧28 h）、缺氧组（无CoCl2预处理过程,其余同预处理组）。用Western Blotting法测细胞VEGF的蛋白表达,RT-PCR测VEGF的mRNA表达,通过乳酸脱氢酶释放率和MTT细胞活力测定判断细胞损伤程度。然后,进一步通过添加VEGF单克隆抗体、重组人VEGF,验证VEGF在化学缺氧预处理组中的保护作用。结果：化学缺氧预处理组细胞VEGF蛋白、VEGF mRNA表达都显著高于缺氧组（P〈0.01）,预处理组细胞较缺氧组细胞存活率高,乳酸脱氢酶释放率减少（P〈0.01）。MTT细胞活力测定显示,40μg/ml VEGF单克隆抗体可抑制预处理的保护作用,而100 ng/ml重组人VEGF可模拟预处理组的保护作用。结论：CoCl2化学预缺氧可保护神经型细胞对缺氧产生耐受,VEGF可能在其中发挥重要的保护作用。     

SH2A 基因对细胞信号转导的影响及其亚细胞定位

目的 研究Src同源域2(src homology 2，SH2)A基因在细胞信号转导中的作用并进行亚细胞定位。方法 通过RT—PCR方法扩增SH2A cDNA编码序列，构建真核重组表达载体pcDNA3．1-SH2A，利用脂质体转染肝癌Bel7402细胞、COS7细胞，检测蛋白酶C(protein kinaseC，PKC)、酪氨酸蛋白激酶(tyrosine protein kinase，TPK)、丝裂原激活蛋白激酶(mitogen activated protein kinase，MAPK)活性的改变；另构建pEGEP—SH2A，转染同前，荧光显微镜观察荧光定位。结果 测序结果显示真核重组表达载体pcDNA3．1-SH2A及pEGFP—SH2A中均含有SH2AcDNA编码序列；肝癌Bel7402细胞、COS7细胞转染pcDNA3．1-SH2A后，胞浆PKC的活性下降了40％左右，MAPK和TPK活性未见明显改变。荧光显微镜观察发现SH2A基因在细胞质中表达。结论 SH2A基因编码蛋白在PKC信号转导通路中起抑制作用；SH2A基因编码蛋白定位于细胞质。     

STAT3 couples with 14-3-3σ to regulate BCR signaling,B-cell differentiation,and IgE production

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高钾时心室肌电——机械交替活动的分析

高钾（１２ｍｍｏｌ／Ｌ）条件下，突然增快刺激频率（１ＨＺ－４Ｈｚ），豚鼠乳头肌发生两轮２：１电－机械交替（ＥＭＡ）。第一轮ＥＭＡ历时约２２－３０ｓ宽的动作电位（ＡＰ）马低的收缩力（Ｆｃ）相对应。间隔性ＡＰ脱落期发生在两轮ＥＭＡ之间，历时约４－６ｍｉｎ。第二轮ＥＭＡ期间，高宽的ＡＰ与高的Ｆｃ相对应。ＡＰ交替消失时Ｆｃ交替也随之消失。第二轮ＥＭＡ历时２２－３４ｍｉｎ（２６±５ｍｉｎ，ｎ＝７），奎尼丁（１μｇ／ｍｌ）显著增强第二轮ＥＭＡ，异搏定（０．５μｇ／ｍｌ）则相反。提示高钾诱发的ＥＭＡ可能与Ｎａ＋，Ｃａ２＋离子流有关。     

In vivo and in vitro effects of imidacloprid on sheep keds (Melophagus ovinus): a light and electron microscopic study

The effects of imidacloprid (Advantage) on sheep keds (Melophagus ovinus Linné 1758) were studied in vivo and in vitro by means of direct observation (monitored on video tape) and by light and electron microscopy. It was found that: 1. Imidacloprid acted rapidly on all motile stages of the sheep keds. Within 3–4 min after exposure they became immobile and their legs and the abdomen started tetanic trembling movements for 15–30 min, leading to death. 2. The compound is apparently taken up by the body, since it also acted on those sheep keds that had been exclusively exposed to imidacloprid-contaminated filter papers. 3. The compound is available and active for more than 1 month in the wool of sheep; even rainfall does not reduce its efficacy. Body contact between treated mother sheep and their lambs protects them from infestation with these ectoparasites. 4. The compound initiates an ultimately lethal destruction of the ganglia, nerve chords and related muscle fibers, as can be seen in electron micrographs. Received: 7 October 2000 / Accepted: 18 October 2000     

地奥心血康对心肌缺血再灌犬心肌细胞膜Na~＋，K~＋—ATP酶活性与LPO含量

１６只成年杂种犬复制心肌缺血再灌模型。分为地奥心血康治疗组（ＤＡＸＸＫＧ）和生理盐水对照组（ＮＳＣＧ）。差速离心分离心肌细胞质膜，无机磷法测定心肌细胞膜Ｎａ￣＋，Ｋ￣＋－ＡＴＰ酶活性，荧光法测定心肌细胞膜与血清脂质过氧化物（ＬＰＯ）含量。结果表明：（１）ＤＡＸＸＫＧＮａ￣＋，Ｋ￣＋－ＡＴＰ酶活性明显高于ＮＳＣＧ（Ｐ＜０．０１）；（２）血清ＬＰＯ含量，随着再灌时间延长，ＮＳＣＧ呈上升趋势，ＤＡＸＸＫＧ略下降，再灌２４０ｍｉｎ两组比较差异显著（Ｐ＜０．０１）；心肌细胞膜ＬＰＯ含量，ＤＡＸＸＫＧ低于ＮＳＣＧ（Ｐ＜０．０５）；（３）心肌细胞膜Ｎａ￣＋，Ｋ￣＋－ＡＴＰ酶活性与ＬＰＯ含量呈明显负相关（ｒ＝－０．８３，Ｐ＜０．０１）。这些结果提示ＤＡＸＸＫ可通过抗脂质过氧化而实现其保护心肌细胞膜的效应。     

Human T lymphocyte activation induces tyrosine phosphorylation of α-tubulin and its association with the SH2 domain of the p59fyn protein tyrosine kinase

A glutathione-S-transferase-src-homology domain 2 (GST-SH2) fusion protein was employed to identify molecules interacting with the protein tyrosine kinase p59^fyn. Among several proteins which bound to the fyn SH2 domain in lysates of human Jurkat T lymphocytes, α- and β-tubulin were identified by N-terminal sequencing. Further analysis established that α-tubulin exists as a tyrosine-phosphorylated protein in Jurkat cells, where it interacts with p59^fyn, but not with p56^lck. By contrast, in untransformed resting human T lymphocytes α-tubulin is not detectable as a tyrosine phosphorylated protein. However, following T cell activation, it becomes rapidly phosphorylated on tyrosine residues and subsequently associates with the SH2 domain of fyn. Interestingly, constitutively tyrosine-phosphorylated α-tubulin that is able to interact with the fyn-SH2 domain is expressed in peripheral blood T lymphoblasts isolated from leukemic patients in the absence of external stimulation.