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The metabolism of human antithrombin III (heparin cofactor) was studied in four control subjects, in four subjects with peripheral obliterative arterial disease, in six patients with recent venous thrombosis and in one patient with clinically severe haemophilia A. The labelled antithrombin III has a high specific activity (5.75 units/mg) and displayed a(More)
BACKGROUND Recombinant staphylokinase offers promise for thrombolytic therapy in acute myocardial infarction, but it is immunogenic. Although reduced immunogenicity of heterologous proteinaceous drugs by protein engineering has not previously been reported, an attempt was made to achieve this in staphylokinase by site-specific mutagenesis. METHODS AND(More)
The activation of plasminogen by t-PA was measured in the presence and absence of fibrin stimulation, using natural human plasminogen (nPlg) and rPlg-Ala740, a recombinant plasminogen with the active site Ser740 mutagenized to Ala. Recombinant wild type t-PA (rt-PA) was used as well as rt-PA-Glu275, a recombinant single chain t-PA in which the Arg of the(More)
Coagulation and fibrinolysis were studied in patients with acute myocardial infarction during intravenous infusion of recombinant human tissue-type plasminogen activator (rt-PA) (0.75 mg/kg over 90 min, n = 101), streptokinase (1,500,000 IU over 60 min, n = 61), or placebo (n = 40). In the rt-PA group, the plasma level of rt-PA antigen was 1.2 +/- 0.6(More)
Rapid inhibition of tissue-type plasminogen activator (t-PA) in human plasma was measured by addition of 5 IU (50 ng) of purified t-PA per ml plasma and measurement of residual t-PA in the euglobulin precipitate after 5 min incubation at 37 degrees C. The recovery of both t-PA activity and t-PA related antigen in pooled plasma from healthy individuals was(More)
A potential synergic effect of tissue-type plasminogen activator (t-PA), single-chain urokinase-type plasminogen activator (scu-PA) or urokinase on clot lysis was investigated in a whole human plasma system in vitro. The system consisted of a human plasma clot labeled with 125I-fibrinogen, immersed in citrated whole human plasma, to which the thrombolytic(More)
The turnover of recombinant pro-urokinase (Rec-pro-UK), recombinant urokinase (Rec-UK) and natural urinary urokinase (Nat-UK) was studied in rabbits and in squirrel monkeys (Saimiri sciureus). Following intravenous injection, urokinase activity disappeared rapidly from the blood. The initial disappearance rate could be described by a single exponential term(More)
Induction of an immune response is strongly dependent on the phylogenetic distance between antigen and recipient. In general, antibodies will not be raised against self-antigens nor against highly conserved domains. In the present study we describe the production and characterization of murine monoclonal "auto-antibodies" against murine tissue-type(More)
Site directed mutagenesis (350 variants) of recombinant staphylokinase (SakSTAR), a potent fibrin-selective thrombolytic agent, was undertaken in order to reduce its antigenicity while maintaining its potency. Variants with K35A, (ie, Lys[K] in position 35 substituted with Ala[A]), E65D or E65Q, K74R or K74Q, E80A+D82A, K130T, and K135R displayed increased(More)
The pharmacokinetic and thrombolytic properties were determined of two recombinant single-chain chimeric plasminogen activators (PA) consisting of u-PA-33k, a low-molecular weight derivative of single-chain urokinase-type PA (scu-PA) comprising amino acids Ala132 through Leu411, and of either a single-chain variable region fragment (Fv) derived from the(More)