The kinetics of the tissue factor-dependent activation of Factors IX and X have been studied in a bovine plasma system. Heat-defibrinated plasma, which lacks Factors VIII, V, and fibrinogen, was depleted of Factors IX and X by using specific antibodies coupled to Sepharose. Activation initiated by the addition of bovine brain thromboplastin was studied by adding back to the plasma radiolabeled ...

Immunoaffinity chromatography using conformation-specific antibodies yields pure factor IX from human plasma in a single rapid, facile purification step. We evaluated this technique to determine whether factor IX can be separated from human T cell leukemia virus-I (HTLV-I) and human immunodeficiency virus (HIV) in plasma supplemented with these viruses. Viral content was determined with an enzy...

Studies were performed to elucidate the functional significance of factor Xa interactions at the monocyte membrane in the presence and absence of factor Va, with respect to prothrombin and factor IX cleavage. Factor Xa-catalyzed prothrombin activation at the monocyte surface was absolutely dependent on the addition of factor Va, indicating that thrombin was generated solely by a membrane-bound ...

We describe the synthesis of a haemoglobin (Hb) wrapped covalently by recombinant human serum albumin mutants [HSA(Y161H)] containing Mn(III) protoporphyrin IX (MnPP), the Hb-[HSA(Y161H)-MnPP]3 cluster, highlighting the formation of its O2-complex stable even in H2O2 solution.

The putative heme oxygenase inhibitor zinc protoporphyrin IX (ZnPP IX) is known to exert diverse actions, including inhibitory action on smooth muscle relaxation by vasoactive intestinal polypeptide (VIP). The studies were performed in the opossum lower esophageal sphincter (LES) smooth muscle to determine the site of the inhibitory action of ZnPP IX in the smooth muscle relaxation by VIP. We a...

We have used the polymerase chain reaction to amplify the entire coding region of canine factor IX from a hemophilia B animal. When the sequence was compared to that which codes for normal canine factor IX, a single missense mutation was identified. This mutation (G----A at nucleotide 1477) results in the substitution of glutamic acid for glycine-379 in the catalytic domain of the molecule. The...

Labeled factor IX was infused five time into four patients with hemophilia-B. Ten-minute plasma recovery average 35% (SD +/- 2) and the mean T 1/2 beta-phase elimination was 23 hr (+/- 5). No alteration in the postinfusion 125I-factor-IX could be detected by radioautography of plasma samples run on polyacrylamide gels or on crossed-immunoelectrophoresis. Label was excreted into the urine as fre...

We have studied the interaction between purified human factor XIa and antithrombin in the presence and absence of well-characterized preparations of heparin. The concentrations of hemostatic enzyme. protease inhibitor. and mucopolysaccharide were 5.76 x iO8 mol/L. 5.76 x iO mol/L. and either 5.88 x iO mol/L or 0. respectively. Kinetic investigation of this process using a tritiated factor IX su...