ABSTRACT
A Trombocitopenia imune (PTI) é uma doença imuno mediada adquirida de adultos e crianças caracterizada por plaquetopenia transitória ou persistente, onde o grau de plaquetopenia aumenta o risco de sangramento. Geralmente, os pacientes apresentam manifestações clínicas apenas em plaquetopenias abaixo de 50x103/mm3, e contagem de plaquetas entre 100 e 150 x103/mm3, se estável por mais de 6 meses, necessariamente não indica uma condição patológica. Tem sido sugerido diferentes processos fisiopatológicos relacionados às plaquetas de acordo com a intensidade da plaquetopenia, e que alterações na megacariocitopoiese e diminuição da sobrevida plaquetária são eventos determinantes na PTI. Contagem de plaquetas reticuladas em citometria de fluxo é um teste muito útil para avaliação da plaquetopenia, pois reflete a atividade megacariocitopoiética, destruição das plaquetas e a própria contagem de plaquetas. Tanto as plaquetas quanto os megacariócitos apresentam a via intrínseca da apoptose. A atividade dos principais mediadores da apoptose intrínseca, como Bax a Bak, é regulada por proteínas anti-apoptótica da família Bcl-2, tais como Bcl-xL. Um balanço entre Bcl-xL e Bax regula a sobrevivência plaquetária. Pacientes de PTI apresentam aumento da ativação plaquetária e da formação de micropartículas derivadas de plaquetas (MPP). Nosso objetivo foi avaliar a relação entre produção e apoptose plaquetária, e associá-la com a ativação plaquetária e a formação de MPP nos diferentes graus de intensidade da PTI. Os pacientes recrutados foram diagnosticados para trombocitopenia imune (PTI) primária, "idiopática", não esplenectomizados, acompanhados regularmente no ambulatório de Doenças Hemorrágicas e Trombóticas, do Serviço de Hematologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, e foram divididos grupos de acordo com contagem de plaquetas: < 50x103/mm3 (n=7); entre 50-100x103/mm3 (n=7); > 100x103/mm3 (n=7). Como grupo...
Immune thrombocytopenic (ITP) is an immune-mediated acquired disease of adults and children characterized by transient or persistent decrease of the platelet count and, depending upon the degree of thrombocytopenia, increased risk of bleeding. ITP usually presents with clinical manifestations only in platelet counts below 50x103/mm3, and counts between 100 and 150x103/mm3 if they have been stable for more than 6 months do not necessarily indicate a pathologic condition. It has been suggested the existence of different pathophysiological processes involving platelets according to the severity of thrombocytopenia, and that alterations in the megakaryopoiesis and reduced platelet lifespan play a key role in ITP. The flow cytometric analysis of reticulated platelets is useful for evaluating thrombocytopenia that reflect the activity megakaryopoiesis, platelets destruction, plataelet count, and age. Platelets and megakaryocytes contain intrinsic pathway of apoptosis. The activity of key mediators of intrinsic apoptosis, Bak and Bax, is tightly controlled by anti-apoptotic Bcl-2 family members, of which Bcl-xL, wich have been shown to coordinately regulate platelet survival. ITP patients have a larger amount of activated platelets that express P-selectin as well as an increase of platelets-derived microparticles (PMP). We suggest a relationship between platelet production and Bcl-xL and Bax expression in ITP patients from different degrees of thrombocytopenia, that has relate with platelet activation and PMP. Our aim was assessment of ratio between platelets production and apoptosis, and it associate with platelets activation and PMP in differents thrombocytopenia degree in ITP. Patients were considered eligible for the study if they were on regular follow-up at the clinic of haemorrhagic and thrombotic diseases of the Hematology Service of Clinics Hospital of University of São Paulo Medicine School diagnosed with primary immune thrombocytopenia, "idiopathic"....
Subject(s)
Apoptosis , Blood Platelets , Cell-Derived Microparticles , Platelet Activation , Purpura, Thrombocytopenic, IdiopathicABSTRACT
Objective To study the platelets activation in patients with acute cerebral hemorrhage and its significance in perihematoma edema.Methods 33 patients with cerebral hemorrhage were treated with minimally invasive surgery.The volume of edema perihematoma was determined by CT technique before operation.The expressions of platelets CD62p and TSP in intracerebral hematoma fluid and venous blood were detected by flow cytometry(FCM).The correlation between the two variables was also analyzed.Results The expressions of platelets CD62p and TSP were higher in patients with acute cerebral hemorrhage than those in healthy individuals,and the expressions of platelets CD62p and TSP in intracerebral hematoma fluid were higher than those in venous blood.There were significant positive correlations between the expression levels of CD62p and TSP from the surface of platelets in hematoma and the edema size perihematoma(CD62p:r=0.4781,TSP:r=0.5183,all P
ABSTRACT
Objective To study the parameters of the postprandial plasma lipoproteins metabolism and the platelet activity change in the elderly patients with coronary heart disease(CHD). Methods 48 elderly patients with CHD (CHD group) and 30 healthy elderly subjects (control group) were enrolled in this study. The levels of plasma lipoproteins including TG, CH, LDL-C and HDL-C, plama PDGF bioactivity, and vWF plasma concentration were measured at 12 hours after fasting and 4 hours after a fat-rich meal. Results The plasma levels of pre-prandial and postprandial TG, CH, LDL-C, PDGF and vWF in the CHD group were significantly higher than those in the control group, while plasma HLD-C level in the CHD group was significantly lower than that in the control group. Compared with fasting state, the levels of plasma TG, CH and LDL-C in the postprandial state significantly increased, but plasma HDL-C level did not significantly decreased. The plasm PDGF and vWF values of CHD group in the postprandial state significantly elevated. Conclusion These data suggested that the plasma lipoproteins metabolism of the elderly patients with CHD was abnormal, and the platelets activation in the elderly patients with CDH was correlated with the changes of postprandial plasma lipoproteins metabolism.
ABSTRACT
0.01).After incubation with trehalose for 4h,the expression of CD62p increased,and it decreased when platelets activation inhibitor PGE-1 and adenosine were added to the incubation buffer.The expression of PAC-1 showed no difference among the three groups. Conclusion The preprocessing before platelets lyophilization has no significant effects on the function and activity of platelets when the platelets activation inhibitor is added.