血小板微粒在血栓性疾病中的诊断价值

正在血栓形成过程中,血管内皮细胞的受损起着非常重要的作用。内皮受损后暴露的胶原激活人体的凝血因子引起血小板聚集,引发凝血过程。血小板在活化的同时释放血小板微粒,血小板微粒具有促凝功能。目前,血小板微粒的检测方法主要是通过流式细胞技术,具有非常高的精确度。血小板微粒在冠心病、脑梗死、慢性阻塞性肺疾病、糖尿病等多种血栓性疾     

血小板微粒在血栓与出血性疾病中的研究进展

血小板微粒(platelet microparticle,PMP)是直径≤1.0μm的超微膜囊泡,经各种不同刺激在血液中导致血小板活化,进而脱落的细小颗粒。1967年,Wolf首先报道了PMP的存在,并将其定义为"血小板尘埃"。这些释放出来的微小颗粒从血小板的质膜中脱落而来,有促凝血和抗凝血的作用。这些微小的颗粒具有整套的血小板膜蛋白和膜脂质等膜结构,主要在血栓形成、促炎反应和调节血管功能方面     

胃黏膜相关淋巴组织恶性淋巴瘤

由于免疫学的进展,黏膜相关淋巴组织（mucosa—associated lymphoid tissue,MALT）淋巴瘤愈来愈多被发现。在胃原发恶性淋巴瘤中,免疫表型显示大多数胃淋巴瘤来自MALT,占原发性胃淋巴瘤50％以上,且以B细胞性MALT淋巴瘤为主,有低度和高度两个亚型。多见于中老年人,发病年龄平均55岁,男性多于女性。其临床生物学行为和组织形态学具有独特性,表现为局限性、惰性生长以及“归巢”的特点。在病因学、病理学、免疫表型和临床转归上有一定规律,属于胃恶性淋巴瘤中较特殊类型。本文将胃MALT的病因,病理,免疫表型和临床特点做一综述。     

血小板和组织因子

组织因子（tissue factor，TF）在凝血和血管内血栓形成中起重要作用，它不仅存在于血管外组织细胞中，而且也存在于血循环细胞中。血中单核细胞可以被内毒素等诱导表达组织因子。近年来许多研究证明，血小板上的P-选择蛋白、CD40配体及GPⅡb／Ⅲa受体等也影响单核细胞表达组织因子。除此之外，有相当多的证据表明，在生理情况下，血循环中也存在组织因子，血小板内的组织因子是其中一部分，它在一定的条件下释放，启动凝血反应。本文就参与凝血的血小板和组织因子的关系作一综述性分析．     

组织因子微粒的研究进展

组织因子微粒(tissue factor-bearing microparticles,TF+MPs)不仅在血栓与止血的生理过程中发挥着重要功能,其在肿瘤、心血管疾病、糖尿病、炎症、溶血性贫血等发病机制中的作用也日益受到关注。本文就TF+MPs的特征、功能、检测及临床应用的研究进展作一综述。     

血小板相关组织因子及其意义的研究

目的探讨正常人血小板是否含有组织因子(TF),血小板相关TF是否具有促凝活性。方法用Sepharose2B凝胶柱分离纯化血小板,ELISA法测定洗涤血小板破碎液TF含量;一期血浆凝固时间测定血小板相关TF促凝活性;RT-PCR法检测正常人血小板相关TF基因的表达。结果正常人血小板破碎液中TF含量为(16.37±6.39)ng/L;胶原活化的血小板可将TF释放到血浆中引起血浆TF水平明显升高(P<0.05);静息血小板无TF的促凝活性,胶原活化的血小板促凝活性显著增高(P<0.01),TF单抗及乏凝血因子Ⅶ(FⅦ)血浆能明显阻断该效应(P<0.01);RT-PCR法在血小板上未能检测到TF mRNA的存在;冠心病患者血小板破碎液TF水平为(20.71±8.78)ng/L,与正常对照相比明显增高(P<0.05),体外未经胶原活化的血小板促凝活性也较正常对照明显增高,并能被TF单抗抑制。结论血小板内含有TF;活化血小板可表现出TF促凝活性;血小板所含的TF可能并非自身合成;冠心病患者血小板相关TF的含量及活性较正常对照明显增高,提示血小板可能可以通过释放TF而参与凝血过程及血栓形成。     

去白细胞血小板对恶性淋巴瘤患者细胞免疫功能的影响

目的观察去白细胞血小板对恶性淋巴瘤患者细胞免疫功能的影响。方法将60名化疗期间需要输注血小板的恶性淋巴瘤患者随机分为两组,输注去白细胞血小板的观察组30例,输注常规血小板的对照组30例,两组患者的化疗方案基本相同。对两组治疗前后的T细胞亚群,NK细胞活性检测进行统计、对比及分析。结果两组患者的细胞免疫功能在治疗前无明显差异,治疗后观察组患者的细胞免疫功能(T3、T4、T4/T8、NK细胞活性)均明显高于对照组(P0.05或P0.01)。结论与常规血小板的输注相比,去白细胞血小板输注能够有效改善恶性淋巴瘤患者的细胞免疫功能。     

微颗粒在血栓及其相关性疾病发生中的作用

微颗粒是从各种不同细胞膜上脱落下来的一类膜性小囊泡,通过细胞表面的刺激,激发细胞凋亡或激活,使微颗粒释放.微颗粒具有促凝、促炎症、促使血管生成和调节内皮功能等作用.现就微颗粒在血栓疾病或血栓相关性疾病中的重要作用及研究进展进行综述.     

胃黏膜相关淋巴组织淋巴瘤研究进展

1983年英国学者Isaacson和Wright首先提出黏膜相关淋巴组织（mucosa—associated lymphoid tissue，MALT）淋巴瘤这一概念，1994年的Real分类将其正式纳入淋巴瘤分类。MALT淋巴瘤的组织病理学定义为发生于黏膜和腺体等组织，具有边缘区B细胞分化和表型的低度恶性的结外B细胞淋巴瘤，约占非霍奇金淋巴瘤的5％-10％，可发生于胃肠道、肺、胸腺、乳腺、腮腺、泪腺、结膜等多处解剖部位，其中胃MALT淋巴瘤是最常见、研究得最透彻的，代表了MALT淋巴瘤的特征。     

Human cell-derived microparticles promote thrombus formation in vivo in a tissue factor-dependent manner

Summary. Background: Circulating microparticles of various cell types are present in healthy individuals and, in varying numbers and antigenic composition, in various disease states. To what extent these microparticles contribute to coagulation in vivo is unknown. Objectives: To examine the in vivo thrombogenicity of human microparticles. Methods: Microparticles were isolated from pericardial blood of cardiac surgery patients and venous blood of healthy individuals. Their numbers, cellular source, and tissue factor (TF) exposure were determined using flow cytometry. Their in vitro procoagulant properties were studied in a fibrin generation test, and their in vivo thrombogenicity in a rat model. Results: The total number of microparticles did not differ between pericardial samples and samples from healthy individuals (P = 0.786). In both groups, microparticles from platelets, erythrocytes, and granulocytes exposed TF. Microparticle‐exposed TF antigen levels were higher in pericardial compared with healthy individual samples (P = 0.036). Pericardial microparticles were strongly procoagulant in vitro and highly thrombogenic in a venous stasis thrombosis model in rats, whereas microparticles from healthy individuals were not [thrombus weights 24.8 (12.2–41.3) mg vs. 0 (0–24.3) mg median and range; P < 0.001]. Preincubation of pericardial microparticles with an inhibitory antibody against human TF abolished their thrombogenicity [0 (0–4.4) mg; P < 0.01], while a control antibody had no effect [19.6 (12.6–53.7) mg; P > 0.05]. The thrombogenicity of the microparticles correlated strongly with their TF exposure (r = 0.9524, P = 0.001). Conclusions: Human cell‐derived microparticles promote thrombus formation in vivo in a TF‐dependent manner. They might be the direct cause of an increased thromboembolic tendency in various patient groups.     

黏膜相关淋巴组织国际预后指数对中国人群黏膜相关淋巴组织淋巴瘤预后的评估价值

目的:探讨黏膜相关淋巴组织(MALT)国际预后指数(IPI)在中国人群MALT淋巴瘤患者中的适用性,并比较不同风险分层方法对MALT淋巴瘤的预后评估价值。方法:回顾2007年1月至2016年12月129例MALT淋巴瘤患者的临床资料,采用Kaplan-Meier法和log-rank法计算并比较MALT-IPI与IPI不同分层分组患者的总体生存率(OS)和无进展生存率(PFS)。结果:129例患者中位发病年龄56岁(22~82岁),其中胃MALT淋巴瘤53例(41.1%),肺MALT淋巴瘤33例(25.6%);Ann ArborⅠ~Ⅱ期71例(55.1%),Ⅲ~Ⅳ期58例(44.9%)。中位随访时间26个月(1~378个月)。总体5年PFS为69.41%,5年OS为90.23%。IPI评分低危、中低危和中高危/高危组患者5年OS、PFS差异无统计学意义;MALT-IPI评分低危、中危和高危组患者5年OS、PFS率逐渐降低,差异有统计学意义(P0.05)。结论:MALT-IPI评分适用于中国人群;相较于IPI评分,MALT-IPI评分对MALT淋巴瘤患者预后具有更好的评估价值。     

急性脑血栓形成和脑动脉硬化患者的血小板活性变化

同步测定了45例急性脑血栓形成、20例脑动脉硬化患者和30例健康人的血小板粘附率、聚集率和血浆β血栓球蛋白(β-TG)、血小板Ⅳ因子(PF_4)含量。结果4项指标在急性脑血栓形成组和脑动脉硬化组均显著高于对照组(P均<0.01),急性脑血栓形成组又显著高于脑动脉硬化组(P<0.01)。作者认为血小板可能是在缺血性脑血管病(ICVD)发生发展的多个环节上起作用的因素。因此,在ICVD的治疗中,抑制血小板活性异常亢进,对改善脑血循环,减轻脑缺血等应是有益的。     

Chitosan microparticles as injectable scaffolds for tissue engineering

The use of chitosan microparticles as injectable carriers for cell transplantation represents a promising alternative to avoid the drawbacks of the implantation of other forms of three-dimensional (3D) scaffolds seeded with cells. In this study, a 3D construct is obtained in vitro by combining chitosan microparticles crosslinked with genipin and goat bone marrow stromal cells (GBMCs). Cell viability and the morphology of GBMCs were evaluated after culture for 7 and 14 days. Our results show the feasibility of chitosan microparticles as potential injectable scaffolds for tissue engineering and regenerative medicine.     

Chemotherapy-induced thrombin generation via procoagulant endothelial microparticles is independent of tissue factor activity

BACKGROUND: Cisplatin-based chemotherapy predisposes cancer patients to thromboembolic events. OBJECTIVES: To investigate whether endothelial damage, via formation of procoagulant endothelial microparticles (EMPs), contributes to cisplatin-related hypercoagulability. METHODS: Cell viability and caspase-3/7 activities were assessed in two endothelial cell (EC) lines [human umbilical vein ECs (HUVECs) and human pulmonary microvascular ECs (HMVEC-Ls)] after exposure to cisplatin (1, 2.5, 5, 10 and 20 microm) for up to 120 h. Counts and procoagulant activity of EMPs were measured by flow cytometry and a thrombin generation assay, respectively. Tissue factor (TF) antigen and TF-dependent procoagulant activity of EMP were determined by enzyme-linked immunosorbent assay and a novel functional assay. RESULTS: By inducing apoptosis, cisplatin dose- and time-dependently decreased the viability of confluent HUVECs and HMVEC-Ls. Progression of EC death was accompanied by an increased release of EMPs (relative increase at 20 microm cisplatin for 48 h vs. control: HUVECs 6.5-fold, P < 0.001; HMVEC-Ls 18.4-fold, P < 0.001). EMPs were highly procoagulant (relative increase at 20 microm cisplatin for 48 h vs. control: HUVECs 2.5-fold, P < 0.001; HMVEC-Ls 5.9-fold, P < 0.001). EMP-driven thrombin generation, however, was not dependent on TF: TF expression and TF procoagulant activity levels on microparticles were only marginal and EMP-associated thrombin generation remained unchanged when the extrinsic pathway was blocked by omission of factor VIIa and/or incubation with an anti-human TF antibody. In contrast, blocking of phospholipids by annexin V markedly diminished EMP-associated procoagulant activity. CONCLUSIONS: In vitro, cisplatin induced the release of EMPs that showed TF-independent procoagulant activity.     

Role of fibronectin assembly in platelet thrombus formation

Fibronectin is a component of subendothelial matrices and abundant in plasma. A role of fibronectin in thrombogenesis has been suspected for three decades. Soluble fibronectin is assembled by adherent fibroblasts and platelets and thus converted to an insoluble form that mediates cell adhesion. Recently, in vivo studies using intravital videomicroscopy revealed that plasma fibronectin is important for stabilization of platelet aggregates after vascular injury. This review goes over roles of fibronectin in platelet functions with a focus on fibronectin assembly within developing platelet thrombi.     

急性脑梗死血小板相关参数的改变

目的 研究急性脑梗死患者治疗前后血小板相关参数的变化.方法 以本院住院的67例急性脑梗死患者为研究对象,利用流式细胞仪、Coulter STKS血球仪同时进行血小板计数(PLT)、血小板平均体积(MPV)、血小板分布宽度(PDW)、血小板膜糖蛋白(CD62P、CD63)、血小板比容(PCT)检测,观察治疗前后血小板相关参数的变化.结果 脑梗死患者治疗前的PLT、MPV、PDW、CD62P、CD63、PCT分别是(155.73±54.73)× 109/L,(9.56±0.27)fl,(16.24±0.35)%,(6.24±3.79)%,(6.23±3.54)%,(0.15±0.07)%;治疗后分别是(175.45±62.49)×109/L,(9.16±0.64)fl,(17.03±0.67)%,(0.98±0.57)%,(2.25±1.50)%,(0.16±0.02)%.MPV、PDW、CD62P、C1363、PCT治疗前后差异有统计学意义(P＜0.05).结论 血小板相关参数的检测结果治疗前后差异有统计学意义,提示与脑梗死的发病具有一定的相关性.