Destruction of factor VIII procoagulant activity in tissue culture media

Destruction of factor VIII procoagulant activity in tissue culture media.

Human endothelial cells have been repoded to synthesize protein that has von Willebrand factor activity and reacts with a heterologous antibody to plasma factor VIll/von Willebrand factor ( FVlll/vWF); however, no FVlll procoagulant activity has been associated with the protein produced by endothelial cells. Of its three biologic properties, only the FVlll procoagulant activity of purified plas...

Apparent molecular weight of purified human factor VIII procoagulant protein compared with purified and plasma factor VIII procoagulant protein antigen.

We have compared apparent molecular weights of purified factor VIII procoagulant protein (VIII:C) and VIII:C antigen (VIII:CAg) by two different NaDodSO4 gel electrophoretic techniques. In a discontinuous NaDodSO4-7.5% polyacrylamide system, reduced and unreduced VIII:C, purified from commercial factor VIII concentrates by a monoclonal antibody immunoadsorption technique, showed a major doublet...

GLucocorticoids inhibit the generation of leukocyte procoagulant (tissue factor) activity.

Expression of tissue factor procoagulant activity: regulation by cytosolic calcium.

Intact bovine fibroblasts, pericytes, and kidney cells manifested significantly less tissue factor procoagulant activity than their disrupted counterparts. Addition of calcium ionophore A23187 rapidly and reversibly enhanced the cell-surface expression of tissue factor in intact cells up to the level achieved by disruption. Inhibitors of calmodulin blocked the ionophore-dependent enhancement of...

Factor VIII procoagulant antigen levels in normal pregnancy and preeclampsia.

It has been suggested that the basis for the marked discordance in factor VIII parameters in preeclampsia is the result of proteolysis of the factor VIII procoagulant component (VIII:C) owing to activation of the coagulation system. To investigate this further, levels were compared of factor VIII:C and VIII:C (Ag), the immunologic equivalent of the procoagulant activity, in a series of preeclam...