紫球藻凝集素的糖蛋白特性

从紫球藻中纯化出紫球藻凝集素(PCL)。经测定该凝集素是一种分子量为39.6kD的糖蛋白,分子中含有28.4%的中性糖。氨基酸组成中缬氨酸(Val)含量最高,异亮氨酸(Iie)含量最低。PLC能凝集兔与猪的红细胞,其凝血活性可被某些单糖或二糖及胃粘蛋白所抑制。PLC对温度变化较为敏感,对酸、碱处理有较好的稳定性。     

体外血小板流动腔研究方法的建立和应用

目的建立模拟体内血液流动环境下，实时观察、研究血小板与血管表面血管性假性血友病因子（vWF）相互作用的模型。方法利用包被vWF的细玻璃管模拟血管，分别采用负压装置、蠕动泵和恒流注射泵产生不同流态和精确剪切率的流体环境，结合倒置显微镜和电荷耦合器件图像传感器（CCD，Charge—coupled device）实时观察和记录血小板或细胞在流体作用下的一系列反应。结果血小板和转染了血小板糖蛋白Ⅰb-Ⅸ的中国仓鼠卵巢细胞（Chinese hamster ovary，CHO），在不同流态下都可与玻璃管壁上的vWF相互作用，从而介导血小板或CHO细胞与玻璃管壁的瞬时结合（滚动），并最终牢固结合在玻璃管壁上。结论本研究方法可以在精确剪切率和不同流态的流体环境条件下，实时地观察、记录血小板与vWF相互作用的情况，为血小板各种生理功能的研究以及相关药物的研究应用创造条件。     

检测大肠癌患者血清糖类抗原CA—50的临床意义

本文应用免疫放射分析法对46例大肠癌患者进行血清糖类抗原CA-50测定,阳性率为 63.04％,均值为 29.57±77.60μ/ml。发现浸润型癌、粘液癌、高分化腺癌 CA—50值明显升高,并与肿瘤大小、侵犯深度、转移情况等呈正相关。提示CA-50值越高,临床病期越晚,手术切除肿瘤的可能性越小,预后亦差。术后定期复查CA-50,如持续不降或下降后又升高,说明肿瘤有复发或转移之可能。     

人正常与结石性胆囊上皮细胞分泌颗粒和溶酶体的定量分析及其意义

作者对２０例胆固醇结石和１５例正常人的胆囊上皮细胞分泌颗粒和溶酶体进行了定量分析，同时测定其胆囊胆汁中的糖蛋白含量，比较两组间的差异。结果显示：结石组胆囊上皮细胞分泌颗粒数、体密度和总面积均明显高于对照组，而溶酶体含量则明显低于对照组；结石组胆汁中糖蛋白含量较对照组高，且胆汁中糖蛋白含量与细胞分泌颗粒数呈正相关，与溶酶体含量呈负相关。作者认为胆囊上皮细胞分泌颗粒影响胆汁糖蛋白量的变化，而溶酶体则可能与细胞内分泌颗粒或蛋白的降解有关，提示胆囊粘膜细胞内结构改变对结石形成起有一定作用。     

A defined peptide that inhibits the formation of the glycoprotein IIb and IIIa complex

Collagen–platelet interaction plays an important role in hemostasis and pathological thrombosis. The proposed mechanism of the interaction was the activation of platelets→releasing of contents from granules→aggregation. The common end point is the platelets and fibrin aggregates. Platelet glycoprotein (GP) IIb/IIIa (the IIbβ3 integrin) complexes serve as a receptor for the binding of fibrinogen to form firmed aggregates. Blockading of GP IIb/IIIa has been proposed to prevent platelet aggregation independent of the substance(s) responsible for activating the platelets. The development of various forms of GP IIb/IIIa inhibitor has resulted in the inhibition of platelet aggregation, although studies of IIbβ3 receptor function and various GP IIb/IIIa inhibitors have demonstrated the potential for these agents to produce effects on other aspects of platelet function as well as having nonplatelet effects. This study investigated platelet inhibition provided by blocking the GP IIb/IIIa complex formation by using a peptide derived from the GP IIIa molecule. The peptide inhibits both types I and III collagen-induced platelet aggregation in a dose-dependent manner. The defined peptide interferes with the formation of the GP IIb/IIIa complex by inhibiting the binding of FITC–PAC-1 onto ADP-, type I collagen-, and type III collagen-activated platelets. However, P-selectin secretion is not affected by the peptide. In addition, the peptide is not interfering with the binding of FITC–PAC-1 to platelets that were preincubated with indomethacin. Results from this study may suggest that the defined peptide is an effective agent to block the interaction of types I and III collagen with platelets.     

环孢菌素A与细胞因子联合逆转白血病多药耐药性的体外研究

目的 探讨环孢菌素Ａ（ＣｓＡ）联合细胞因子对耐药细胞系Ｋ５６２／Ａ０２的逆转作用,方法 以甲基四唑蓝法测定柔红霉素（ＤＮＲ）的细胞毒性,用流式细胞仪技术测定细胞内罗丹明（Ｒｈ１２３）浓度,用ＲＴ－ＰＣＲ及ＪＳＢ－１抗体分别检测多药耐药（ＭＤＲ１）ｍＲＮＡ及其Ｐ糖蛋白的表达。结果 １μｍｏｌ／ＬＣｓＡ,５００Ｕ／ｍｌ干扰素２００Ｕ／ｍｌ白介素２（ＩＬ－２）均能增加ＤＮＲ对耐药细胞系Ｋ５６２／Ａ０２的     

Intranasal vaccination with ebola virus GP amino acids 258–601 protects mice against lethal challenge

Ebola virus (EBOV) disease (EVD) leads to lethal hemorrhagic fever with a case fatality rate as high as 90%, thus posing a serious global public health concern. However, while several vaccines based on the EBOV glycoprotein have been confirmed to be effective in animal experiments, no licensed vaccines or effective treatments have been approved since the first outbreak was reported in 1976. In this study, we prepared the extracellular domain of the EBOV GP protein (designated as N20) by prokaryotic expression and purification via chromatography. Using CTA1-DD (designated as H45) as a mucosal adjuvant, we evaluated the immunogenicity of N20 by intranasal administration and the associated protective efficacy against mouse-adapted EBOV challenge in mice. We found that intranasal vaccination with H45-adjuvanted N20 could stimulate humoral immunity, as supported by GP-specific IgG titers; Th1 cellular immunity, based on IgG subclasses and IFN-γ/IL-4 secreting cells; and mucosal immunity, based on the presence of anti-EBOV IgA in vaginal lavages. We also confirmed that the vaccine could completely protect mice against a lethal mouse-adapted EBOV (MA-EBOV) challenge with few side effects (based on weight loss). In comparison, mice that received N20 or H45 alone succumbed to lethal MA-EBOV challenge. Therefore, mucosal vaccination with H45-adjuvanted N20 represents a potential vaccine candidate for the prevention of EBOV in an effective, safe, and convenient manner.     

Entactin: ultrastructural localization of an ubiquitous basement membrane glycoprotein in mouse skin

Summary Entactin is a recently described sulfated glycoprotein component of mouse endodermal cell-derived extracellular matrix and is present in a number of basement membranes. It has been ultrastructurally localized to both lamina densa and adjacent epithelial cell membranes in rodent kidney. In the present study, we have sought to determine the localization of entactin in mouse skin. Indirect immunofluorescence and immunoelectron microscopy (the latter via immunoperoxidase technique) were performed on both intact and NaCl-separated mouse skin, using a well-characterized IgG class entactin-specific ratxmouse monoclonal antibody. At the light microscopic level, entactin was present in all skin basement membranes. On NaCl-split skin, staining was noted solely on the dermal portion. At the electron microscopic level, in intact skin, entactin was primarily localized to the lamina densa and adjacent upper papillary dermis. However, smaller amounts of immunoreaction products were also detectable within the lamina lucida and in close apposition to overlying hemidesmosomes. In partially separated skin, immunoreactants were similarly noted above the level of the lamina densa. However, in completely separated areas, hemidesmosomal or cell membrane staining was no longer visible. We conclude that entactin is an ubiquitous component of mouse skin basement membranes. Similar to previous findings in rodent kidney, entactin is present in multiple regions of skin basement membrane, although its primary localization remains within and directly beneath the lamina densa.Presented in part at the annual Southern Regional meeting of the Society for Investigative Dermatology, New Orleans, Louisiana, February 3, 1989. Supported in part by the National Institutes of Health (NIAMS AR34861, JDF; NIAMS AR36457 & AF39741, JRC)