background: among diverse protein purification systems, affinity chromatography is the most attractive one in the purification process of coagulation factors. coagulation factor vii is a plasma serine protease that has a significant role in natural human hemostasis and its recombinant form such as aryoseventm, has been applied in clinical treatment of bleeding disorders. immunoaffinity chromato...

background recombinant activated factor vii (rfviia; novoseven® rt, novo nordisk, bagsvaerd, denmark) is a synthetic pro-coagulation factor derived from hamster kidney cells. objectives the purpose of this study was to evaluate the prescribing patterns of recombinant factor viia (rfviia) at a single, tertiary care pediatric hospital by indication of usage and dose administered. materials and me...

Activation of factor IX in an umbilical vein model was established to result solely from factor VIIa/tissue factor (TF) activity generated within the umbilical vein wall, and the model was then used to study regulation of such extravascular factor VIIa-TF complexes. Vein segments were filled with a reaction mixture containing factor VIIa, Ca2+, a substrate, either [3H]factor IX or [3H]factor X,...

Because free factor VIIa is inactivated only very slowly by a plasma concentration of antithrombin III (AT III) even in the presence of heparin, it has been assumed that AT III plays no significant role in regulating the initiation of tissue factor-dependent blood coagulation. However, in the present study, we present evidence that factor VIIa bound to tissue factor, unlike free factor VIIa, is...

Standard treatment for Glanzmann thrombasthenia, a severe inherited bleeding disorder, is platelet transfusion. Recombinant factor VIIa is reported to be effective in Glanzmann thrombasthenia with platelet antibodies and/or refractoriness to platelet transfusions. We aimed to evaluate recombinant factor VIIa effectiveness and safety for the treatment and prevention of surgical bleeding in patie...

High doses of recombinant factor VIIa are useful in managing bleeding in hemophiliacs with inhibitors. Whether this therapeutic effect of factor VIIa is dependent on tissue factor (TF) is a matter of debate. We examined the ability of freshly isolated human monocytes (which lack TF) to support the activation of coagulation-factor X by factor VIIa. The rate of factor-X activation by factor VIIa ...

We have extended earlier studies (Blood 66:204, 1985) of a mechanism of inhibition of factor VIIa/tissue factor activity that requires a plasma component (called herein extrinsic pathway inhibitor or EPI) and factor Xa. An activated peptide release assay using 3H-factor IX as a substrate was used to evaluate inhibition. Increasing the tissue factor concentration from 20% to 40% (vol/vol) overca...

The ability of factor VIIa to initiate thrombin generation and clot formation in blood from healthy donors, blood from patients with hemophilia A, and in anti-factor IX antibody-induced ("acquired") hemophilia B blood was investigated. In normal blood, both factor VIIa-tissue factor (TF) complex and factor VIIa alone initiated thrombin generation. The efficiency of factor VIIa was about 0.0001 ...

Human coagulation Factors VII and VIIa bind with equal affinity to monocytes stimulated with endotoxin. Equilibrium binding studies performed at 0 degrees C using 125I-labeled Factor VII and VIIa showed the dissociation constant (Kd) to be congruent to 82 pM with congruent to 3,600 binding sites/monocyte. Ca++ was required for Factor VII and VIIa interaction with monocytes (optimal CaC12 concen...

The ability of factor VIIa to initiate thrombin generation and clot formation in blood from healthy donors, blood from patients with hemophilia A, and in anti–factor IX antibody–induced (“acquired”) hemophilia B blood was investigated. In normal blood, both factor VIIa–tissue factor (TF) complex and factor VIIa alone initiated thrombin generation. The efficiency of factor VIIa was about 0.0001 ...