Mouse primary skin fibroblasts were infected with a recombinant retrovirus containing human factor IX cDNA. Bulk infected cells capable of synthesizing and secreting biologically active human factor IX protein were embedded in collagen, and the implant was grafted under the epidermis. Sera from the transplanted mice contain human factor IX protein for at least 10-12 days. Loss of immunoreactive...

Thrombosis and transmission of viral diseases are the principal adverse effects of current replacement therapy for factor IX deficiency when using heat-treated concentrates of vitamin K-dependent coagulation factors. More highly purified factor IX preparations could decrease the risk of disease transmission, reduce patient exposure to allogeneic proteins, and reduce the risk of thrombosis. In t...

In this paper, we report an inhibitor antibody to factor XI (FXI) in a woman with severe inherited FXI deficiency, induced by FXI present in an Rh immune globulin preparation. The patient is homozygous for the Glu117Stop mutation, associated with a FXI level of less than 1 U/dL. Unlike all previously described patients with severe FXI deficiency and an inhibitor, the patient had never been expo...

Previous studies have shown that factor IX and its activated form, factor IXa, bind to cultured vascular endothelial cells and that cell-bound factor IXa retains its procoagulant activity. The present studies provide evidence that factor IX bound to cultured bovine aortic endothelial cells can be activated. Factor IX activation was assessed by finding cleavage of the factor IX molecule on NaDod...

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,...

Hemophilia B is a rare X-linked recessive disorder with plasma factor IX (FIX) deficiency. 1-3% of patients treated with exogenous FIX-containing products develop inhibitors (i.e. polyclonal high affinity immunoglobulins) that neutralize the procoagulant activity of a specific coagulation factor. Although the incidence of inhibitors in hemophilia B patients is low, most are "high titer" and fre...

The effect of two arginine-specific cysteine proteinases (gingipains R) from Porphyromonas gingivalis, an aetiological factor of adult periodontitis, on the activation of human factor IX was investigated in the presence of ethylene glycol, an activity enhancer of activated factor IX (factor IXa), with the use of a fluorogenic oligopeptide substrate. Each gingipain R rapidly activated factor IX ...

abstract  introduction: during extrinsic coagulation pathway, a complex is developed between factor vii, calcium and tissue factor (a cell membrane lipoprotein that is exposed after cell injury). factor vii needs calcium and vitamin k for its biologic activation. coronary artery disease (cad) can be induced by increased level and activity of the coagulation factors vii, viii and ix. in postmeno...

Hemophilia is a bleeding disorder that results from genetic alteration in production of coagulation factors that are important to maintain hemostasis. The commonest type is hemophilia A due to deficiency of factor VIII (FVIII), which is important zymogen co factor for clot formation. Hemophilia A is an X-linked disease that affects males at prevalence of 1:5000-10000. Hemophilia B is due to def...