人乳腺珠蛋白的研究进展

人乳腺珠蛋白 (hMAM)为乳腺组织特异性蛋白 ,是一种新的可能具有临床应用前景的乳腺癌标志物。近几年国内外研究者对hMAM在乳腺、淋巴结、外周血和骨髓中的表达及其与乳腺癌的关系做了大量工作 ,结果不尽相同 ,提出了不同的观点。现对hMAM及其基因在乳腺癌检测中的研究现状作一综述     

血小板型磷脂酶A2抗菌活性的研究进展

磷脂酶A2(PLA2)是一类能水解磷脂Sn-2位脂键的酶,也是生物化学、基因工程和药理学研究的热点酶类.近几年来一个重要发现就是某些型别PLA2具有抗菌功能,研究得最早且最多的是血小板型PLA2,它主要对G+菌具有强的抗菌活性,在宿主防御细菌感染中发挥重要作用.现就血小板型PLA2抗菌活性的研究进展作一综述.     

Animal models for studies on cold-induced platelet activation in human beings

When human platelets are chilled below about 20 degrees C, they spontaneously activate, a phenomenon that limits their storage lifetime. We have previously shown that this activation in chilled human platelets is associated with passage through a lipid phase transition. Because animal models are necessary for Investigating methods for cold storage of platelets, it is essential to determine whether such phase transitions and chilling-induced activation are found in these models. In this study we examined platelets from some commonly used animal models-pigs, rhesus monkeys, mice, dogs, and rabbits. Using Fourier transform infrared spectroscopy (FTIR), we detected the thermotropic membrane phase transition in Intact platelets and assessed the morphologic response of the platelets to chilling. Statistical analysis of both FTIR and shape change show that of the animal models tested, pig platelets are most similar to human platelets. These studies suggest that pigs and pig platelets are the models of choice for the study of cold-induced platelet activation in human beings.     

超广谱β—内酰胺酶的研究进展

产生超广谱β-内酰胺酶是大多数细菌对β-内酰胺类抗生素耐药的重要机制。笔对超广谱β-内酰胺酶的产生机制、分类、检测方法、耐药谱及其主要的产生菌种等研究进展进行了综述。     

血小板直接胶原受体的研究进展

胶原是内皮下基质的主要成分，现已发现有18种，至少有7种胶原存在于血管壁，以Ⅰ、Ⅲ和Ⅳ型胶原最为重要。胶原不仅引起血小板黏附，而且还是血小板聚集的强诱导剂。当血管壁受损后，会暴露出内皮细胞下的胶原，血小板迅速与胶原相互作用，伸展于暴露的内皮细胞表面，并被活化释放出颗粒中的物质，活化的血小板其表面糖蛋白成分、含量和构象都发生了变化，引起血小板聚集并促进凝血，最终导致血栓的形成。在这个过程中，血小板与胶原相互作用，即血小板黏附是始动因素，引发了下游一系列的反应，如血小板聚集、释放反应等，最终导致血栓形成。     

血小板微粒释放及对肿瘤作用的研究进展

随着单采血小板保存时间的延长,血小板活化增加,血小板微粒释放增多。血小板微粒是直径为100 nm—1μm的活化的血小板膜脱落的囊泡,具有细胞间信息传递的作用,是血小板功能的延伸,具有促凝、促进炎症反应和促进肿瘤浸润和转移,影响肿瘤细胞生长等作用。血小板微粒中含有微粒内有蛋白、线粒体、mRNA、miRNA和其他非编码RNA等物质调节自身的功能。血小板微粒能释放和运输生长因子、细胞受体、micRNA和促进炎性细胞因子,促进肿瘤的浸润和转移,影响肿瘤的增值。血小板微粒通过MAPK、MMPs和EMT等途径影响肿瘤细胞释放外泌体。研究表明血小板微粒中多种miRNA参与肿瘤增值和转移的调控作用。     

漫游球菌的研究进展

1989年Collins等报道了漫游球菌属,当时只有1个种,截止到2004年已增加到5个种,其中只有河流漫游球菌与人类感染有关,可从患者的血液、腹膜液和伤口中分离而来,其他漫游球菌尚未发现有引起人类感染的报道,鉴于国内尚无报道,临床细菌学实验室在从临床标本分离出肠球菌样细菌时,应注意与漫游球菌的鉴别,以免漏检.     

漫游球菌的研究进展

1989年Collins等报道了漫游球菌属,当时只有1个种,截止到2004年已增加到5个种,其中只有河流漫游球菌与人类感染有关,可从患者的血液、腹膜液和伤口中分离而来,其他漫游球菌尚未发现有引起人类感染的报道,鉴于国内尚无报道,临床细菌学实验室在从临床标本分离出肠球菌样细菌时,应注意与漫游球菌的鉴别,以免漏检。     

深部真菌耐药性的研究进展

近年来深部真菌感染的发病率呈上升趋势,由于抗真菌药物在临床上大量使用,深部真菌的耐药现象日益增多,耐药真菌感染的治疗已成为一个棘手的临床问题.对耐药机制的深入探讨,可为寻找控制耐药真菌感染的最佳策略提供线索.     

深部真菌耐药性的研究进展

近年来深部真菌感染的发病率呈上升趋势,由于抗真菌药物在临床上大量使用,深部真菌的耐药现象日益增多,耐药真菌感染的治疗已成为一个棘手的临床问题。对耐药机制的深入探讨,可为寻找控制耐药真菌感染的最佳策略提供线索。     

Study on fibrinolysis and platelet function]

The aim of this study is to evaluate the relationship between tissue plasminogen activator (tPA)/PA inhibitor (PAI) complex and PAI, and platelet in the circulating blood. tPA/PAI complex and active PAI (act PAI; Teijin Co., Japan), and PAI antigen (PAI ant; Biopool AB, Sweden) were assayed by enzyme immunoassay (EIA). The mean concentrations (ng/10(9) platelets) in supernatant from lysate of platelet rich plasma (PRP) and washed platelets were 27.1 +/- 9.2, 1.5 +/- 1.2 in tPA/PAI complex, 188.7 +/- 46.1, 83.3 +/- 7.5 in act PAI and 236.2 +/- 41.6, 191.9 +/- 45.1 in PAI ant, respectively. PRP was mixed with ADP (10(-5), 10(-4), 10(-3) M), for 3 min and the supernatant after centrifugation then was provided for assay of PAI and tPA/PAI complex. Concentrations of act PAI, PAI ant and tPA/PAI complex dose-dependently increased with ADP. Almost the same results were obtained, when collagen and other agents were used instead of ADP. This study revealed that platelets contained quantities PAI (as free PAI) and released PAI during aggregation, and that a part of the PAI immediately formed a complex with tPA. Those findings suggested that platelets may play an important role on the formation of thrombus, in the way of anti-fibrinolysis, in addition to novel platelet functions, such as aggregation.     

Survivin的研究现状

Survivin是一个新发现的凋亡蛋白抑制剂 (inhibitorofapoptoticprotein ,IAP)家族成员 ,它具有独特的结构和功能。本文就Survivin的结构和生物学特性 ,Survivin在胚胎、肿瘤和正常成人组织的表达及Survivin与肿瘤的诊断、治疗和预后的研究现状作一综述     

Studies on human platelet protease activity

Solubilized protein derived from human platelets was fractionated by DEAE cellulose column chromatography and analyzed for protease activity using three substrates: denatured bovine hemoglobin, alpha casein, and purified plasminogen-free human fibrinogen. A protein fraction was found with proteolytic activity which was heat labile and not attributable to plasmin. The activity was not potentiated by cysteine or inhibited by iodoacetamide. Studies of pH optima indicated a broad range of enzyme activity with peaks in both the acid and alkaline region. Cathepsin A activity was detected in the platelet protease fraction by hydrolysis of the synthetic substrate N-carbobenzoxy-α-L-glutamyl-L-tyrosine. Similar proteolytic activity was found when the proteins derived from isolated platelet granules were examined. The results indicate that human platelets possess potent intracellular proteolytic enzymes. The relationship of this proteolytic activity to the hemostatic process is discussed.     

Studies on human platelet protease activity

SOLUBILIZED PROTEIN DERIVED FROM HUMAN PLATELETS WAS FRACTIONATED BY DEAE CELLULOSE COLUMN CHROMATOGRAPHY AND ANALYZED FOR PROTEASE ACTIVITY USING THREE SUBSTRATES: denatured bovine hemoglobin, alpha casein, and purified plasminogen-free human fibrinogen. A protein fraction was found with proteolytic activity which was heat labile and not attributable to plasmin. The activity was not potentiated by cysteine or inhibited by iodoacetamide. Studies of pH optima indicated a broad range of enzyme activity with peaks in both the acid and alkaline region. Cathepsin A activity was detected in the platelet protease fraction by hydrolysis of the synthetic substrate N-carbobenzoxy-alpha-L-glutamyl-L-tyrosine. Similar proteolytic activity was found when the proteins derived from isolated platelet granules were examined. The results indicate that human platelets possess potent intracellular proteolytic enzymes. The relationship of this proteolytic activity to the hemostatic process is discussed.