AIMS To determine the distribution of factor VIII related antigen, CD31, CD34 and CD36 in normal and malignant human vascular tissues using a panel of well characterised monoclonal antibodies. METHODS Frozen and fixed material from a wide range of normal tissues and routinely processed material from 43 benign and malignant vascular tumours were examined. Single immunocytochemical labelling wa...

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...

A new type II variant form of von Willebrand's disease has been recognized in a mother and daughter who have bleeding manifestations typical of von Willebrand's disease. Laboratory findings include consistently prolonged bleeding times, with normal levels of factor VIII procoagulant and antigen, but decreased ristocetin cofactor activity. Electrophoresis in SDS 1.5% agarose gel and reaction wit...

Seven new cases of pregnancy combined with von Willebrand's disease have been reported. Altogether the patients had 11 deliveries, and one abortion after 10 weeks' gestation. The diagnosis was based on the determination of the bleeding time, factor VIII coagulant activity (VIII C), factor VIII-related antigen (VIII RAg) and the ristocetin cofactor (VIII RCoF). Two of our 6 parturients showed pr...

The possible role of Ca2+ as an essential constituent part of the human factor VIII complex has been investigated by stability studies, metal determinations, and gel filtration experiments. In citrated plasma, the factor VIII coagulant activity (VIII:C) deteriorated during storage in a biphasic manner. Collection of blood in heparin, instead of chelating anticoagulants, or neutralization of cit...

The factor VIII clotting activity (VIIIc1 and factor VIII related antigen (VIIIRAg) were determined repeatedly in 24 pairs of age-matched normal women, one of each pair being on oral contraceptives. No significant differences in either parameter or in the VIIIc/VIIIRAg ration were found between the two groups ,although the mean factor VIII clotting activity and VIIIc/VIIIRAg ratios for women on...

Factor VIII related antigen, an endothelial cell product, was markedly raised in systemic necrotising arteritis, reflecting disease activity, but was not raised in active cutaneous vasculitis. In rheumatoid arthritis high levels were only found in systemic vasculitis or Felty's syndrome, but in other connective tissue diseases increased levels were more frequently detected and usually related t...