Biomaterial Database

In vivo recovery of factor VIII: a comparison of one-stage and two-stage assay methods. 1979

I M Nilsson, and T B Kirkwood, and T W Barrowcliffe

The recovery and half-life of VIII:C in the plasma of severely haemophilic patients was measured by one-stage and two-stage assays after injection of two Factor VIII concentrates (Hemofil, Hyland and Fraction I-O, Kabi). Plasma volumes were measured with an Evans' Blue technique, and both concentrates and post-infusion samples were measured against the same plasma standard. There was a highly significant difference in recoveries estimated by the two assay methods. The one-stage assays gave the most consistent results, in that the average recovery was 100%, whereas the two-stage assays gave only about 80% of the value expected from in vitro assays. There was no differences in recoveries between the two concentrates. The two-stage assays gave a slightly shorter half-life than the one-stage assays, and the half-life of Hemofil was also shorter than that of Fraction I-O.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D005169	Factor VIII	Factor VIII of blood coagulation. Antihemophilic factor that is part of the factor VIII/von Willebrand factor complex. Factor VIII is produced in the liver and acts in the intrinsic pathway of blood coagulation. It serves as a cofactor in factor X activation and this action is markedly enhanced by small amounts of thrombin.	Coagulation Factor VIII,Factor VIII Clotting Antigen,Factor VIII Coagulant Antigen,Factor VIII Procoagulant Activity,Thromboplastinogen,Blood Coagulation Factor VIII,F VIII-C,Factor 8,Factor 8 C,Factor Eight,Factor VIIIC,Hyate-C,Hyatt-C,F VIII C,Hyate C,HyateC,Hyatt C,HyattC
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D006467	Hemophilia A	The classic hemophilia resulting from a deficiency of factor VIII. It is an inherited disorder of blood coagulation characterized by a permanent tendency to hemorrhage.	Factor VIII Deficiency,Hemophilia,Autosomal Hemophilia A,Classic Hemophilia,Deficiency, Factor VIII,Factor 8 Deficiency, Congenital,Factor VIII Deficiency, Congenital,Haemophilia,Hemophilia A, Congenital,Hemophilia, Classic,As, Autosomal Hemophilia,Autosomal Hemophilia As,Classic Hemophilias,Congenital Hemophilia A,Congenital Hemophilia As,Hemophilia A, Autosomal,Hemophilia As,Hemophilia As, Autosomal,Hemophilia As, Congenital,Hemophilias, Classic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001681	Biological Assay	A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.	Bioassay,Assay, Biological,Assays, Biological,Biologic Assay,Biologic Assays,Assay, Biologic,Assays, Biologic,Bioassays,Biological Assays