Fibrinolysis最新文献

For genetic population studies, human genomic DNA is commonly isolated from peripheral blood. A fast, non-invasive DNA sampling method is developed involving oral samples taken with cotton swabs. In addition various procedures were compared for isolation of DNA from different sources: whole blood or buffy-coats stored at −20°C for 5–10 years or buccal cells collected freshly with the non-invasive method. The differences in these procedures, which do not contain a phenol-extraction, are based on the use of either 1) high concentration ammonium acetate followed by DNA precipitation or 2) high concentration potassium acetate, followed by chloroform extraction and normal DNA precipitation.

Various coagulation abnormalities were reported in HIV-infected patients, which were usually considered as risk factors for thrombosis in the general population or in other disease states. This study was undertaken to determine whether HIV-infection was associated with an on-going pre/prothrombotic state. For that purpose, 70 consecutive HIV-infected out-patients were evaluated at distance of any acute episode. (55 males and 15 females with a mean age of 34 years, range: 19–69). 29 patients (41%) with a CD4+ lymphocytes count below 200 × 10⁶/L were classified as having AIDS. The control group consisted of 33 age and sex-matched healthy individuals. The plasma levels of sensitive markers of thrombin generation (prothrombin fragment 1+2 and thrombin-antithrombin complex), plasmin generation (plasmin-plasmin inhibitor complex), and plasmin activity (fibrin degradation products) were measured using ELISAs. The plasma level of these markers were significantly higher in HIV-infected patients than in healthy HIV-negative controls. Moreover, the plasma levels of these markers were found to be highly significantly correlated (p<0.001) in the patients group, suggesting an increased activation of both coagulation and fibrinolysis. However, despite trends toward increasing levels with decreasing CD4+ lymphocyte count, the plasma levels of these markers were not significantly different in AIDS and in non AIDS patients (classified upon the CD4+ lymphocytes count below and above 200 × 10⁶/L). These results suggest that HIV-infection is associated with an activation of both the coagulation and fibrinolytic systems, which could lead to a prothrombotic state in some of the patients.

The objective of this study was to investigate the role of the plasminogen activation system in the migration of human vascular smooth muscle cells in vitro. After wounding of confluent human smooth muscle cell cultures by stripping cells from their extracellular matrix, cells start to migrate from the wounded edge into the denuded area. Addition of plasmin to the culture medium resulted in an approximately 50% increase of migrated cells after 24 hours. The plasmin inhibitor aprotinin was able to reduce this effect to control levels. Migration could also be stimulated by addition of urokinase-type plasminogen activator (HMW-u-PA) (30%) or tissue-type plasminogen activator (t-PA) (28%). Simultaneous addition of aprotinin reduced this increase below control levels, indicating that both HMW-u-PA and t-PA mediated plasminogen activation contributes to smooth muscle cell migration. Addition of low molecular weight u-PA (LMW-u-PA), a u-PA form lacking the receptor binding domain, or the aminoterminal fragment of u-PA (ATF), lacking the active site, had no effect on migration. These results suggest that both t-PA and u-PA can contribute to human smooth muscle cell migration in vitro, most likely via plasminogen activation. For the stimulation of migration by u-PA, activity as well as binding to its cell-surface receptor appears to be involved.