人胚胎海马发育的形态学研究 Ⅴ.室管膜的发生

运用HE和Nissl染色、免疫组织化学法、透射电镜及扫描电镜，对60例6周至足月的人胚胎海马室管膜上皮变化进行了观察。发现胚胎发育过程中室管膜发生了剧烈变化。最早室管层神经上皮细胞为假复层柱状，随着未分化细胞向外迁徙，海马室管膜层神经上皮细胞迅速增殖，形成复层上皮。当室管膜层细胞停止迁徙时，室管膜开始向假复层柱状及单层柱状上皮转变。电镜观察，胚胎早期神经上皮细胞由未分化细胞构成；其特点是，细胞质内各种特化细胞器匮乏，但糖原丰富。15周左右未分化细胞开始向长突细胞及室管膜细胞分化。长突细胞电子密度高，底部有细长突起，表面有微绒毛，胞质内微丝丰富；而室管膜细胞电子密度低，底部无突起，但表面有丰富的纤毛。对长突细胞及免疫组化染色的GFAP阳性细胞进行形态和发育特征的比较，提示两者属同一类细胞。扫描电镜下，15周前室管膜表面微绒毛较多，以后纤毛逐步发育，大量密集纤毛布满于室管膜表面。此外，还能见到一类接触脑脊液神经元，这类神经元可为多极或双极，并有突起伸入室管膜上皮内。     

Differential expression of binding sites for chemokine RANTES on human T lymphocytes

The C-C chemokine RANTES, a T lymphocyte chemoattractant, is considered an important mediator of inflammation, allergy, and host defense against HIV-1 infection. In this study, we investigated the modulation of binding of RANTES to T lymphocytes. Human peripheral blood CD3+ T cells, when freshly isolated from buffy-coat blood, expressed a considerable number of high-affinity binding sites for RANTES. These cells also showed significant chemotactic migration in response to RANTES in vitro. After 6–15 h incubation at 37°C, the binding of RANTES, but not of macrophage inflammatory protein-1α (MIP-1α) or of monocyte chemotactic protein-3 (MCP-3), consistently increased. Scatchard analyses indicated that the number of binding sites for RANTES increased about threefold by 15 h without any change in the affinity. The increase in RANTES binding was no longer detected by 24 h. This increase in the specific binding was mainly attributable to CD4⁺ T cells and was not associated with increased chemotactic activity of these cells in response to RANTES. Incubation with anti-CD3 antibody for 15 h markedly reduced the binding capability of T cells for RANTES and was associated with decreased chemotactic activity. On the other hand, when T cells were incubated with interleukin-2 (IL-2) for 1 week, the specific binding for all three C-C chemokines, RANTES, MIP-1α, and MCP-3 was markedly increased in comparison to cells cultured in the absence of IL-2. These results suggest that the expression of binding sites on T cells for RANTES is differentially modulated, indicating the existence of novel receptors for RANTES that do not bind MIP-1α.     

Absence of a prominent Th2 cytokine response in human tuberculosis.

Depressed Th1 responses are a prominent feature of human tuberculosis, but an enhanced Th2 response has not been detected in peripheral blood T cells stimulated in vitro with Mycobacterium tuberculosis. In disease due to Mycobacterium leprae, Th2 cells predominate in tissue lesions of patients with extensive disease but are absent from peripheral blood. To determine if Th2 cells are present in tissue lesions of tuberculosis patients, we evaluated patterns of cytokine expression in lymph nodes from tuberculosis patients with or without human immunodeficiency virus infection and in controls without tuberculosis. Gamma interferon and interleukin-10 (IL-10) mRNA expression in tuberculosis patients with or without human immunodeficiency virus infection was high, whereas IL-4 expression in the same patients was low. Immunolabeling studies showed that macrophage production of IL-12 was increased in lymph nodes from tuberculosis patients, that gamma interferon was produced by T cells, and that IL-10 was produced by macrophages rather than Th2 cells. These results indicate that Th2 responses are not enhanced either systemically or at the site of disease in human tuberculosis.     

胎肝细胞质液对重症病毒性肝炎患者外周血TL－CFU及mIL－2R影响的实验观察

采用半固体一步单层琼脂培养法和单克隆荧光抗体技术分别观察重症肝炎外周血ＴＬ－ＣＦＵ和ｍＩＬ－２Ｒ，发现重症肝炎患者ＴＬ－ＣＦＵ（１０４．４±３２．６）及ｍＩＬ－２Ｒ（３５．６±８．６）较正常人明显降低。在培养体系中加胎肝细胞质液后，无论在重症肝炎组还是在正常组均不能明显地提高ＴＬ－ＣＦＵ，说明胎肝细胞质液不含具生物佐的促ＴＬ－ＣＦＵ因子。但对ｍＩＬ－２Ｒ表达的影响，在重症肝炎组病人，只有在ＰＨＡ存在条件下才能促进ｍＩＬ－２Ｒ的表达，说明胎肝细胞质波含有某种（些）物质能协同ＰＨＡ促进重症肝炎患者外周血淋巴细胞ｍＩＬ－２Ｒ表达。     

ST2作为Th2细胞亚群标志以及其与支气管哮喘的关系的研究

各自主要分泌IFN γ和IL 4的Th1和Th2亚群 ,与临床疾病的关系十分密切。如何从表面标志上加以区分是一项迫切需要解决的问题。ST2是近年来提出的Th2细胞的稳定标志物。本工作在体外成功地诱导人脐带血T细胞向Th1或Th2分化的基础上 ,应用逆转录PCR分析了ST2mRNA的表达特点。证实ST2在人Th2细胞上的选择性表达。为了探索ST2、Th2与支气管哮喘的关系 ,本工作进一步检测了正常人和支气管哮喘患者外周血单个核细胞中 β actin、ST2以及IFN γ和IL 4的mRNA水平。结果显示 :支气管哮喘患者ST2mRNA水平升高 ,IL 4水平也明显升高 ,但IFN γ无变化。这提示ST2作为Th2细胞的标志物 ,有可能成为Th2极化性疾病如哮喘发病机制研究的一个参考性标志 ,至于ST2是否有可能作为治疗的靶分子 ,有待进一步探讨     

保留瓣下结构的几种机械瓣下游血流动力学多普勒超声研究

了解二尖瓣置换术mitralvalvereplacement,MVR保留瓣下结构对不同类型机械瓣下游血流动力学的影响,为合理选择术式以最大限度减少手术并发症提供科学依据。方法采用彩色多普勒超声结合计算机图像分析技术,对保留瓣下结构的不同类型机械瓣置换术后患者机械瓣下游湍流剪应力turbulentshearstress,TSS等指标进行体内定量研究。结果无论保留全瓣或后瓣,跨瓣血流边界位点TSS在两种不同构型机械瓣组间均存在显著性差异(P<0.05),单叶机械瓣(单叶瓣)TSS较双叶机械瓣(双叶瓣)高。对于单叶瓣,TSS在保留全瓣瓣下结构组(保留全瓣组)、保留后瓣瓣下结构组(保留后瓣组)与未保留瓣下结构组(未保留组)间均存在显著差异(P<0.05)。而对于双叶瓣,保留全瓣组TSS均高于其它2组(P<0.05)。结论保留瓣下结构可改善术后患者心功能,但却在一定程度上增加跨瓣血流扰动性,使下游TSS增大。这种影响以全瓣保留者为著,单叶瓣甚于双叶瓣。对于心功能较差,有必要保留全瓣瓣下结构者,可尽量使用双叶瓣,以减轻对人工心瓣下游血流动力学可能产生的不良影响。     

细胞低温显微图象的计算机处理及定量分析

本文用计算机图象处理技术对细胞显微图象进行处理和定量分析,求出了细胞面积在低温保存中极其重要的参数。实验证明,计算机测量比人工精度高,误差小,同时新颖的标号去噪方法也非常有效。     

股骨上端形态曲线的测量、参数化与统计分析

通过对84根完好的中国人成人股骨标本进行正位和侧位两个方向的X线摄影，得到股骨正、侧两方位的X光片。对X光片上股骨上端髓腔内侧形态进行描绘，将描绘好的图像输入计算机，由计算机进行图像预处理后提取其曲线形态数据，并将形态数据参数化，从而得到可比较的、能准确表现股骨形态的量化数据，为股骨形态的分类分析和系列型人工髋关节的参数设计打下基础。     

人Nanog基因的克隆及其在COS-7L细胞中的表达

目的 :克隆人Nanog基因 ,构建其真核表达载体 ,并观察其在哺乳动物细胞COS 7L中的表达。方法 :利用HE2 93细胞的人基因组DNA为模板 ,以LA PCR技术 ,扩增Nango的基因 ,定向克隆到带Flag标签的pCMV载体中 ,测序后 ,挑选序列正确的真核表达质粒pFlag Nanog转染COS 7L细胞。用抗Flag标签的抗体 ,进行Westernblot和间接免疫荧光染色法检测Nango蛋白的表达。结果 :从人基因组DNA中克隆到序列正确的Nanog全长编码序列。所构建的Nanog质粒在COS 7L细胞中获得高效表达。结论 :人Nanog基因的克隆、真核表达载体的构建及在COS 7L中的表达均获得成功 ,为进一步研究其功能 ,尤其是探讨其在神经干细胞中的作用奠定了基础。