The present studies were undertaken to determine whether factor VIII/von Willebrand factor (vWF) present in the vessel wall (in addition to that in plasma) may mediate the attachment of platelets to subendothelium. Subendothelium from everted rabbit aorta was exposed to human citrated blood flowing through an annular perfusion chamber at 40 mL/min (wall shear rate of 2,600 s-1 for five minutes)...

The synthesis, processing, and secretion of factor VIII expressed from heterologous genes introduced into Chinese hamster ovary cells has been studied. The results show factor VIII to be synthesized as a primary translation product of approximately 230 kDa that can be detected in the lumen of the endoplasmic reticulum. In this compartment, the majority of the factor VIII is in a complex with a ...

BACKGROUND: Combined factor V and VIII deficiency (CF5F8D) is a rare autosomal recessive disorder, with an estimated prevalence of about 1:100,000 in the Jewish population. Affected individuals have between 5 and 30% of normal levels of factor V and VIII, whereas the levels of other plasma proteins are not altered. This bleeding disorder has been treated by replacement therapy with plasma infus...

Fulminant hepatic failure (FHF) in humans produces a bleeding diathesis due in large part to a reduction in the biosynthesis of liver-derived coagulation factors. Remarkably, factor VIII procoagulant activity is elevated in most of these patients despite widespread liver cell death. FHF can be modeled in mice by administration of azoxymethane, the active ingredient found in cycad palm nuts. We ...

Introduction. Elevated factor VIII population in the Indian population has not been studied as a possible risk factor for deep vein thrombosis (DVT). High factor VIII level is considered a predisposing factor for DVT and its recurrence. However it is known to vary between populations and its exact role in the etiopathogenesis of thrombophilia remains unknown. Material and Methods. Factor VIII l...

Activated platelets release their granule content in a concentrated fashion at sites of injury. We examined whether ectopically expressed factor VIII in developing megakaryocytes would be stored in alpha-granules and whether its release from circulating platelets would effectively ameliorate bleeding in a factor VIIInull mice model. Using the proximal glycoprotein 1b alpha promoter to drive exp...

When purified antihemophilic factor (Factor VIII) was rechromatographed on 4% agarose in 0.15 M NaCl or 1.0 M NaCl, a single protein peak, containing both procoagulant activity and von Willebrand factor activity, as defined by ristocetin-induced platelet aggregation, was eluted in the void volume. Purified Factor VIII immediately lost about 30% of its procoagulant activity when dissolved in 0.2...

The physiologic activities concerned with hemostasis and associated with the Factor VIII macromolecular complex were investigated in swine with von Willebrand's disease after infusion of cryoprecipitate, a lyophilized Factor VIII concentrate, or porcine serum. Immediately after each infusion the various activities antihemophilic factor, von Willebrand platelet aggregating factor, and Factor VII...

An elevated factor VIII level has been shown to be an independent risk factor for venous thrombosis. However, physicians screen for this factor far less frequently than they screen for other coagulopathies. The causes of increased factor VIII levels are likely a combination of genetic and acquired variables. The authors describe a case of a healthy 48-year-old woman found to have a cerebral ven...

UNLABELLED INTRODUCTION The development of factor VIII inhibitors is a serious complication of replacement therapy in patients with congenital hemophilia A. Immune tolerance induction has been accepted as the only clinically proven treatment allowing antigen-specific tolerance to factor VIII. However, some of its issues, such as patient selection, timing, factor VIII dosing, use of immunosup...