Using a new technique for antigen localization. we have demonstrated platelet proteins in megakaryocytes in plastic-embedded biopsy specimens of normal human bone marrow. In a series of 25 specimens. megakaryocytes showed labeling with antibodies to the integral membrane glycoproteins lIla. llb. and the lIb-Illa complex; granule membrane protein 140; and five alpha-granule matrix proteins: thro...

Epithelioid hemangioendothelioma is a relatively rare lesion. Although its histogenesis has been well described, its immunohistochemical characteristics remain controversial. A case of epithelioid hemangioendothelioma of the soft tissue of the right leg in a 67-year-old Chinese woman is reported. Histologic findings of intracytoplasmic lumina in the tumor cells and positive immunostaining for v...

Epinephrine infusion causes variable increases in the components of the Factor VIII (antihemophilic factor) complex in patients with von Willebrand's disease. The increase in antihemophilic factor procoagulant activity was greater than that of Factor VIII-related antigen and von Willebrand factor activity in two patients with von Willebrand's disease. Similar increases in the three individual f...

In normal plasma, the ratio of the procoagulant activity of factor VIII (VIII(AHF)) to that of the von Willebrand factor activity (ristocetin cofactor, VIII(VWF)) or factor VIII antigen (VIII(AGN)) is approximately 1, but ratios > 1 (e.g., VIII(AHF) > VIII(VWF) or VIII(AGN)) may be observed in some patients with von Willebrand's disease and in the "late" posttransfusion plasmas of patients with...

The development of anti-factor VIII antibodies is a major complication of the treatment of patients with hemophilia A. Generation of high affinity anti-factor VIII antibodies is dependent on help provided by CD4+ T cells that recognize factor VIII-derived peptides presented on class II major histocompatibility complex on the surface of antigen-presenting cells. In order to identify the immune-d...

Concentration of factor VIII from fresh plasma by cryoprecipitation remains the basis for preparation of products used to treat haemophilia A. This paper describes the preparation of a factor VIII concentrate from small plasma pools in transfusion centres with drying facilities. The dried concentrate from one litre of plasma dissolves very well in 50 or 100 ml of distilled water and contains ar...