A murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable fr...

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...

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...

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...

A persistent low-titer factor IX Inhibitor was discovered in a patIent with severe hemophllia B. The Inhibitor was very likely an immunoglobulin, since it was present in serum, was not dialyzable, retained its potency after heating to 56#{176}C, and was bound by staphylococcal protein A (SPA). When the hemophilia B patient with the inhibItor was given therapeutic infusions of factor Ix concentr...

DNA from nine hemophilia B patients who produce anti-factor IX inhibitors (antibodies), including two brothers, was analyzed by the Southern blotting method and hybridization with factor IX cDNA, intragenomic, and 3'-flanking probes. Two inhibitor patients were shown to have total deletions of the factor IX gene. Two other inhibitor patients, the brothers, were shown to have a presumably identi...