Thrombosis research
-
Thrombosis research · Apr 1985
Assessment of thrombogenicity of prothrombin complex concentrates in a porcine model.
Infusion of prothrombin complex concentrates into pigs resulted in evidence of disseminated intravascular coagulation manifested by positive fibrin monomer tests, depletion of coagulation factors and platelets, and the presence of fibrin in small blood vessels at autopsy. All of the nine prothrombin complex concentrates were found to be thrombogenic. The response appeared to be dose-related, and the two activated materials were more thrombogenic than the non-activated products. ⋯ Four of these animals received 200 factor IX units/kg, which was twice the dose used for any of the other products. Control animals received human plasma or albumin with no evidence of coagulation changes or fibrin deposition at autopsy. The porcine model is more sensitive than other animal models for detection of the thrombogenic effects of prothrombin complex concentrates and may be useful for testing new products found to be non-thrombogenic in other test procedures.
-
Thrombosis research · Mar 1985
Comparative StudyThe role of fibronectin in factor VIII/von Willebrand factor cryoprecipitation.
To evaluate the role of fibronectin (Fn) in factor VIII (FVIII) and von Willebrand factor (vWf) cryoprecipitation, factor VIII procoagulant activity, factor VIII coagulant antigen, factor VIII-related antigen and von Willebrand ristocetin cofactor activity were measured in cryoprecipitate and cryosupernatant from normal and Fn-depleted plasmas. Following cryoprecipitation of normal plasmas, most of the FVIII and almost all the FvWf recovered were found with a part of Fn and of fibrinogen in cryoprecipitate. ⋯ Experiments performed with Fn-depleted plasma to which purified fibronectin had been added, and samples of plasma with decreased Fn levels (0.01 to 0.2 g/l) suggest that there is a relation between initial Fn level and the extent of FVIII/vWf cryoprecipitation. We conclude that Fn, like fibrinogen, is necessary to induce cryoprecipitation of FVIII/vWf and that an initial plasma level of 0.2 g/l is sufficient to obtain good recovery of FVIII/vWf in cryoprecipitate.