title: [Heparin and antiheparin in young children. 1. Report: development of a method for determining heparin and antiheparin in the antithrombin-thrombin system].
abstract: A new method of determining the biological activity of heparin and antiheparin is described. The principle is based on measuring the coagulation time in the antithrombin-thrombin system. By using a partially purified antithrombin III preparation and after coagulating the plasma samples with small amounts of thrombin the measuring system proves to be mostly independent on the inhibitory content of the test plasmas to be investigated. Heat defibrinated plasma cannot be used because it has essential properties with a close affinity to heparin. Additions of sodium and calcium ions will make the system more sensitive. Criteria of reaction kinetics are used for standardizing the antithrombin-thrombin system. The heparin level of up to 0.01 U/ml and the antiheparin titre of up to 0.005 U/ml can be covered by the procedure presented. Thus, it has a high sensitivity. The quality controls which were performed give evidence of the high precision of this method.
mesh_terms: D000990:Antithrombin III / Q000494:pharmacology* / Q000592:standards; D001774:Blood Chemical Analysis / Q000379:methods*; D001779:Blood Coagulation Factors / Q000032:analysis*; D001780:Blood Coagulation Tests / Q000379:methods; D002648:Child; D006493:Heparin / Q000097:blood* / Q000592:standards; D006801:Humans; D010978:Platelet Factor 4 / Q000032:analysis*; D011786:Quality Control; D013917:Thrombin / Q000494:pharmacology / Q000592:standards
chemical_list: D001779:Blood Coagulation Factors; D010978:Platelet Factor 4; D000990:Antithrombin III; D006493:Heparin; D013917:Thrombin
vernacular_title: Heparin und Antiheparin im Kindesalter. 1. Mitteilung: Entwicklung eines Verfahrens zur Heparin- und Antiheparinbestimmung im Antithrombin-Thrombin-System.