Orthostatic stress causes significant plasma shift and raises transmural pressure in lower extremities, resulting in an increase in endothelial activation and plasma proteins concentrations, possibly including coagulation factors. This may lead to activation of the coagulation system during standing. To test this hypothesis, we recruited 18 healthy volunteers (9 females and 9 males; mean age: 2...

BACKGROUND Recombinant activated factor VII (factor VIIa) is a prohemostatic agent that can be used for patients with complicated coagulation disorders. Recombinant factor VIIa is, however, increasingly used for several other indications, including patients with a preexistent normal coagulation system but who experience serious bleeding, for example, after major surgery or trauma. DATA SOURCE...

Cerebral venous thrombosis (CVT) rarely recurs, and the factors associated with a recurrence remain unclear. Recently, however, elevated plasma coagulation factor VIII has been considered a factor related to recurrent venous thromboembolism. Here we report a patient who had recurrent CVT associated with significantly elevated levels of factor VIII despite the chronic use of an antiplatelet agen...

During surface-initiated blood coagulation in vitro, activated factor XII (fXIIa) converts factor XI (fXI) to fXIa. Whereas fXI deficiency is associated with a hemorrhagic disorder, factor XII deficiency is not, suggesting that fXI can be activated by other mechanisms in vivo. Thrombin activates fXI, and several studies suggest that fXI promotes coagulation independent of fXII. However, a recen...

During surface-initiated blood coagulation in vitro, activated factor XII (fXIIa) converts factor XI (fXI) to fXIa. Whereas fXI deficiency is associated with a hemorrhagic disorder, factor XII deficiency is not, suggesting that fXI can be activated by other mechanisms in vivo. Thrombin activates fXI, and several studies suggest that fXI promotes coagulation independent of fXII. However, a recen...