培养大鼠皮层神经元NMDA受体蛋白单分子原子力显微镜定位研究

为在纳米尺度对 NMDA受体蛋白分子进行神经细胞膜表面原位定位和探讨原子力显微镜在生物单分子操纵和调控中的应用 ,本研究应用原子力显微镜分别对分布在云母表面的膜 NMDA受体蛋白分子标记物抗 NMDAR1Ig G-葡萄球菌蛋白 A-胶体金复合物分子和结合标记物分子后的神经元膜进行扫描 ,三维形貌测定 ,通过颗粒度分析结果 ,明确标记物分子的特征性三维形貌 ,对比确定经过免疫胶体金结合后的 NMDA受体蛋白单分子在神经元膜表面的定位。结果显示 ,空白云母表面标记物分子为分散均匀的平均粒径为 49nm的球形颗粒 ,在神经元膜表面结合 NMDA目的受体蛋白分子后 ,免疫复合物分子呈现出粒径为 5 3 nm的散在分布球形或短棒状颗粒 ,长径约为宽径的 2倍 ,长轴截面可见典型的双峰三维结构。上述结果表明 ,NMDA受体蛋白单分子可以结合 1个或 1个以上的胶体金标记物分子 ;原子力显微镜可以在纳米尺度对神经元膜 NMDA受体蛋白进行标记和其免疫复合物的三维形貌测定。胶体金颗粒标记 ,原子力显微镜测定是免疫细胞化学新方法。     

细胞间黏附分子1基因K469E多态性与冠状动脉粥样硬化性心脏病的关联研究

目的研究中国汉族人群中细胞间黏附分子1（intercellular adhesion moleculel，ICAM1）基因K469E多态性与冠状动脉粥样硬化性心脏病（简称冠心病）的关联。方法采用聚合酶链反应．限制性片段长度多态性方法检测了173例冠心病患者和141名对照的ICAM1基因K469E基因型和等位基因的分布。结果基因型频率符合Hardy-Weinberg平衡。冠心病组的KK基因型的频率显著高于对照组（64．2％比48．9％，P〈0．01），同样，冠心病组K等位基因的频率显著高于对照组（79．2％比69．9％，P〈0．01）。经Logistic回归分析排除年龄，性别，和冠心病其它危险因素的影响后，KK纯合子患冠心病的危险性是KE和EE基因型的2．35倍（95％CI：1．03-5．36，P〈0．05）。结论ICAM1基因K469E多态性与中国汉族人冠心病的危险性相关，其中K等位基因可能是冠心病的遗传危险因素。     

Expression of CD4-like structure on murine egg vitelline membrane and its signal transductive roles through p56lck in fertilization.

Expression of CD4-like molecule on vitelline membrane of murine eggs was demonstrated by indirect immunofluorescence (IIF) test and immunoprecipitation corresponding to the expression of major histocompatibility complex (MHC) class II molecule on murine sperm detected by immunoblotting. This molecule showed slightly larger size than that of the authentic CD4 molecule from T-cells on SDS-PAGE. This molecule was suggested to bind to MHC class II structure on sperm during fertilization because anti-CD4 monoclonal antibody (mAb) blocked in vitro fertilization (IVF). In addition, src-related tyrosine protein kinase (p56lck) was demonstrated in the inner vitelline membrane of eggs by means of IIF with anti-p56lck mAb and immune-complex kinase assay. This molecule was suggested to be associated with CD4-like molecule.     

滋养层细胞侵入相关基因在先兆子痫胎盘中的表达

探讨与滋养层侵入有关的细胞外基质分子相关基因在先兆子痫胎盘中的表达，采用分别点样有220余种人细胞因子相关基因和人类激素相关基因cDNA片段的两款基因芯片，检测经过严格配伍的先兆子痫和正常胎盘组织的基因表达谱差异。结果显示：钙粘蛋白、胶原、整合素、选择蛋白等18种细胞外基质分子基因的表达在先兆子痫和正常胎盘组织间相差2倍以上，且全部表现为在先兆子痫胎盘中的表达增强。先兆子痫患者的胎盘组织中基质金属蛋白酶(MMP)-10、-13、-15和金属蛋白酶组织抑制因子(TIMP)-2、TIMP-3、纤溶酶原、纤溶酶原激活物等的表达均较正常者高。提示胎盘中细胞外基质分子及其降解酶基因表达异常可能与先兆子痫的病理发生关系密切。     

Molecular weights of individual proteins correlate with molecular volumes measured by atomic force microscopy

 Proteins are usually identified by their molecular weights, and atomic force microscopy (AFM) produces images of single molecules in three dimensions. We have used AFM to measure the molecular volumes of a number of proteins and to determine any correlation with their known molecular weights. We used native proteins (the TATA-binding protein Tbp, a fusion protein of glutathione-S-transferase and the renal potassium channel protein ROMK1, the immunoglobulins IgG and IgM, and the vasodilator-stimulated phosphoprotein VASP) and also denatured proteins (the red blood cell proteins actin, Band 3 and spectrin separated by SDS-gel electrophoresis and isolated from nitrocellulose). Proteins studied had molecular weights between 38 and 900 kDa and were imaged attached to a mica substrate. We found that molecular weight increased with an increasing molecular volume (correlation coefficient = 0.994). Thus, the molecular volumes measured with AFM compare well with the calculated volumes of the individual proteins. The degree of resolution achieved (lateral 5 nm, vertical 0.2 nm) depended upon the firm attachment of the proteins to the mica. This was aided by coating the mica with suitable detergent and by imaging using the AFM tapping mode which minimizes any lateral force applied to the protein. We conclude that single (native and denatured) proteins can be imaged by AFM in three dimensions and identified by their specific molecular volumes. This new approach permits detection of the number of monomers of a homomultimeric protein and study of single proteins under physiological conditions at the molecular level. Received: 14 February 1997 / Received after revision: 8 September 1997 / Accepted: 8 September 1997     

ICAM-3, the third LFA-1 counterreceptor,is a co-stimulatory molecule for both resting and activated T lymphocytes

Optimal activation of human T cells mediated by ligation of CD3/T cell receptor (TcR) complex requires co-stimulatory signals. These can be provided by the adhesive interaction between receptor molecules on T cells and their counter-receptors on antigen-presenting cells. Soluble ICAM-3, anti-ICAM-3 and anti-CD3 mAb were utilized to address the role of the ICAM-3/LFA-1 pathway in TcR/CD3-dependent or -independent T cell activation. Immunoaffinity-purified ICAM-3 co-immobilized with suboptimal concentrations of anti-CD3 monoclonal antibody (mAb) stimulated T lymphocytes as monitored by the expression of the lymphocyte activation antigens CD25 and CD69. The mechanism underlaying this activation appear to involve the interaction of ICAM-3 with a β2 integrin, likely to be LFA-1, since mAb to the CD18 chain completely inhibited T cell activation. Similar experiments demonstrated that anti-ICAM-3 mAb were able to co-stimulate both resting (cord blood) and activated (T cell clones) T lymphocytes. On the contrary, anti-ICAM-1 mAb were only co-stimulatory for CD25 expression on activated but not on resting T cells. In addition, we have found that some γδ T cell clones bearing the Vδ1 segment were activated by direct mAb engagement of ICAM-3 in the absence of TcR/CD3 occupancy. Furthermore, immobilized anti-ICAM-3 mAb also induced development of dentritic processes. In conclusion, our data suggest that ICAM-3 on the surface of both T cells and antigen-presenting cells plays an essential role in the initiation of the immune response.     

GITR: a multifaceted regulator of immunity belonging to the tumor necrosis factor receptor superfamily

Glucocorticoid-induced TNFR-related gene (GITR; TNFRSF18), a receptor belonging to the TNFR superfamily (TNFRSF), is activated by GITRL. GITR is expressed at low levels on resting responder T lymphocytes and is up-regulated in T regulatory cells (Treg cells) and in activated T cells. GITRL is expressed in endothelial and antigen-presenting cells. The cytoplasmic region of GITR has a striking homology with other TNFRSF members (4-1BB, CD27, OX40) and binds TRAF molecules and Siva. Over recent years, the role of GITR in the development and in the pathophysiology of the immune system has been actively explored by several groups. GITR triggering induces both pro- and anti-apoptotic effects, abrogates the suppressive activity of Treg cells and co-stimulates responder T cells, with the latter activities over-stimulating the immune system. In vivo, GITR activation causes development of autoimmune diseases and restores immune responses in a persistent retroviral infection model and in a tumor model. Intriguingly, GITR knockout mice demonstrate lower mortality in an ischemia model. The GITR-GITRL system appears crucial in regulating immunity and warrants further study.     

Effects of ethanol on murine aggression assessed by biting of an inanimate target

The effects of acutely administered ethanol (0, 0.5, 1.0 and 2.0 g/kg, IP) were studied in a tube-restraint/target biting model of aggressive responding using naive group-and individually-housed male Swiss mice. Behavioural measures were the latency to the first bite and the biting frequency. In saline-injected control animals, the levels of responding were significantly higher in group-housed than isolated mice. Animals given alcohol exhibited a dose-dependent suppression of biting frequency, and an increase in biting latency. Mice experienced in the tube-testing situation showed reduced baseline levels of biting, but alcohol produced similar effects to those in naive mice. There was no evidence of a biphasic action of alcohol.     

目标管理在医疗设备维修管理中的应用与效果分析

分析目标管理在医疗设备维修管理中的应用效果,选取2019年1月至2020年12月医疗设备维修数据,对比分析实施目标管理前后的设备整体平均维修时长、维修关单良好率、基础性设备(病床、监护仪及泵类)平均维修时长和工程师维修关单良好率,为医院维修管理精细化实践提供参考。     

不同阻滞阶段非梗阻性无精子症的生物信息学分析

目的：利用生物信息学筛选不同阻滞阶段非梗阻性无精子症（NOA）相关的调控因子及其调控途径,为后续的功能研究提供依据。方法：从GEO（Gene Expression Omnibus）数据库中获得GSE45885的基因表达谱矩阵,筛选其中的正常样本以及不同阻滞阶段NOA样本,包括4例正常生精样本和20例NOA患者样本,20例NOA患者中有2例患者处于减数分裂前期阻滞阶段（PRE）,7例处于减数分裂期阻滞阶段（MEI）,11例处于减数分裂后期阻滞阶段（POST）。将正常生精样本设置为对照组（CON）,使用GEO2R在线工具鉴定正常生精样本与不同阻滞阶段NOA样本之间的差异基因,对GEO芯片中不同阻滞阶段的NOA数据整合归一化并进行矫正后取交集。对差异表达的基因以及其靶基因进行GO（Gene Ontology）和KEGG（Kyoto Encyclopedia of Genes and Genomes）富集分析,获取关键通路;基于在线工具（STRING）构建蛋白质相互作用（PPI）网络图。然后利用Cytoscape中的CytoHubba插件对枢纽基因进行筛选。结果：在PRE中筛选出463个上调基因,12个下调基因;在MEI和POST中分别发现2个和3个下调基因,无上调基因。PRE中上调基因通过一些重要途径,如精子发生、精子细胞发育、精子的运动、纤毛运动和微管形成等功能来调控生精过程。在上述的3个阻滞阶段NOA中筛选出2个共同差异基因,均为微小RNA（miRNA）,2个miRNA有58个共同靶基因。利用在线生物信息学工具STRING成功构建PRE中上调基因的PPI网络图,并使用Cytoscape筛选出网络中前10个枢纽基因,包括DNAI1、DNAI2、PGK2、ROPN1L、ARMC4、DRC1、DNAAF3、CABYR、ZMYND10和CCDC65。结论：识别枢纽基因和共同差异基因及其通路为后续研究NOA的发生机制提供了有价值的参考,DRC1、ARMC4、MIR15A和MIR509-3可作为后续NOA发病机制研究的潜在靶点。