Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heparin-induced thrombocytopenia with thrombotic complications is a serious clinical problem. The diagnosis is confirmed by a positive heparin-induced platelet aggregation test and/or detection of white clots upon pathological exam after a presumptive diagnosis based on these criteria: (1) Development of thrombocytopenia of less than 100,000 mm3 while receiving heparin therapy; (2) Normalization of the platelet count after an interruption in heparin therapy; (3) The presence of thrombotic complications; and (4) Exclusion of other causes of thrombocytopenia. Eight patients with heparin-induced thrombocytopenia were encountered at the Charleston Area Medical Center, Memorial Division, in a recent 20-month period. Various types of heparin, routes of administration, and indications were implicated. The mean platelet nadir was 25,750 mm3 and the mean time to onset of of heparin-induced thrombocytopenia was 4.9 days. Thrombotic complications included seven patients with arterial occlusions of the legs, six with deep-vein thrombosis of the legs (three had pulmonary embolism), and five with combined arterial and venous thrombosis. Treatment strategies included discontinuation of heparin in all patients; intravenous infusion of dextran in five patients, followed by arterial thrombectomy in three patients; urokinase therapy in two patients for arterial thrombotic complications; and insertion of Greenfield filters in four patients for venous thrombotic complications. All surviving patients were given warfarin. The mortality rate was 25 percent and the morbidity rate was 38 percent. In conclusion, an initial platelet count should be obtained on all patients prior to receiving heparin, followed by repeat platelet counts every two to three days. Once thrombocytopenia or thrombosis is diagnosed, heparin should be discontinued and other therapeutic modalities considered.
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PMID:Heparin-induced thrombocytopenia with thrombotic complications. 157 77

Thrombolysis of acute pulmonary embolism can be accomplished more rapidly and safely with 100 mg of recombinant human tissue-type plasminogen activator (rt-PA) (Activase) than with a conventional dose of urokinase (Abbokinase) given as a 4,400-U/kg bolus dose, followed by 4,400 U/kg per h for 24 h. To determine the effects of a more concentrated urokinase dose administered over a shorter time course, this trial enrolled 90 patients with baseline perfusion lung scans and angiographically documented pulmonary embolism. They were randomized to receive either 100 mg/2 h of rt-PA or a novel dosing regimen of urokinase: 3 million U/2 h with the initial 1 million U given as a bolus injection over 10 min. Both drugs were delivered through a peripheral vein. To assess efficacy after initiation of therapy, repeat pulmonary angiograms at 2 h were performed in 87 patients and then graded in a blinded manner by a panel of six investigators. Of the 42 patients allocated to rt-PA therapy, 79% showed angiographic improvement at 2 h, compared with 67% of the 45 patients randomized to urokinase therapy (95% confidence interval for the difference in these proportions [rt-PA minus urokinase] is -6.6% to 30.4%; p = 0.11). The mean change in perfusion lung scans between baseline and 24 h was similar for both treatments. Three patients (two treated with rt-PA and one with urokinase) had an intracranial hemorrhage, which was fatal in one. The results indicate that a 2-h regimen of rt-PA and a new dosing regimen of urokinase exhibit similar efficacy and safety for treatment of acute pulmonary embolism.
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PMID:Recombinant tissue-type plasminogen activator versus a novel dosing regimen of urokinase in acute pulmonary embolism: a randomized controlled multicenter trial. 160 32

This study describes our experience with 12 patients with white clot syndrome encountered during a recent 36-month period. The diagnosis was based on the following criteria: (1) development of thrombocytopenia of less than 100,000/mm3 during administration of heparin therapy, (2) normalization of the platelet count after an interruption in heparin therapy, (3) exclusion of other causes of thrombocytopenia, (4) a positive heparin-induced platelet aggregation test, (5) detection of white clots on pathologic examination, and (6) the presence of thrombotic complications. Of 2,500 patients who received heparin therapy, 12 (0.48%) developed white clot syndrome. Various indications, routes of administration, and types of heparin were implicated. The mean platelet nadir was 26,900/mm3, and the mean time to onset of heparin-induced thrombocytopenia was 5 days. Thrombotic complications included arterial occlusions of the legs in 11 patients, deep vein thrombosis of the legs in 9 patients (4 had pulmonary embolism), and combined arterial and venous thrombosis in 8 patients. Treatment strategies included discontinuation of heparin in all patients and intravenous infusion of dextran, followed by arterial thrombectomy in four patients, urokinase therapy in two patients for arterial complications, and insertion of Greenfield filters in six patients. All patients were given warfarin. The mortality rate was 25% and the morbidity rate was 50%. An initial platelet count should be obtained on all patients prior to receiving heparin, followed by repeat platelet counts every 2 to 3 days. Once thrombocytopenia or thrombosis is diagnosed, heparin should be discontinued and other methods of therapy considered.
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PMID:Diagnostic and therapeutic strategies of white clot syndrome. 171 45

Twelve centers participated in a double-blind study in which 63 patients with angiographically documented acute massive pulmonary embolism were randomly assigned to treatment with either urokinase (4,400 U/kg as an intravenous bolus infusion, then 4,400 U/kg per h over 12 h; n = 29) or alteplase (10 mg as an intravenous bolus infusion, then 90 mg over 2 h) followed by heparin (n = 34). The primary objective was to compare the resolution of pulmonary embolism as judged by the change in total pulmonary resistance over the initial 2 h. Further objectives were to evaluate the changes in total pulmonary resistance over the next 10 h and the degree of angiographic resolution at 12 to 18 h. At 2 h, total pulmonary resistance decreased by 18 +/- 22% in the urokinase group and by 36 +/- 17% in the alteplase group (p = 0.0009). Continuous monitoring of pulmonary artery mean pressure, cardiac index and total pulmonary resistance revealed that these variables improved faster in the alteplase group, with consistently significant intergroup differences from 30 min up to 3 to 4 h. After 12 h, the decrease in total pulmonary resistance was 53 +/- 19% in the urokinase group compared with 48 +/- 17% in the alteplase group and the reduction in the angiographic severity score was 30 +/- 25% compared with 24 +/- 18%, respectively, with no significant intergroup differences. Bleeding was equally frequent in the two treatment groups, except that more urokinase-treated patients experienced hematomas at puncture sites.
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PMID:Effects of intravenous urokinase versus alteplase on total pulmonary resistance in acute massive pulmonary embolism: a European multicenter double-blind trial. The European Cooperative Study Group for Pulmonary Embolism. 173 48

For the treatment of massive pulmonary embolism thrombolytic therapy is efficient in reducing late mortality and complications from chronic pulmonary hypertension. Best results are achieved if treatment is started as soon as possible. Even after days or weeks after pulmonary thromboembolism, however, thrombolytic therapy is beneficial. In life threatening conditions due to right heart failure an initial bolus of 2,000,000 U urokinase should be administered. The number of contraindications can be markedly reduced due to the well controlled thrombolysis with urokinase.
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PMID:Thrombolytic therapy in fulminant pulmonary thromboembolism. 178 41

A hybrid hybridoma (FU1-74), secreting a bispecific monoclonal antibody (bs mAb), was obtained by fusion of a murine hybridoma secreting a monoclonal antibody (mAb) specific for human fibrin with a murine hybridoma secreting a mAb against urokinase-type plasminogen activator (u-PA). The bs mAb (MA-FU1-74), purified to homogeneity from mouse ascitic fluid, migrated as a single band with apparent Mr 150,000 on nonreduced SDS-PAGE and had an affinity for both human fibrin (Ka = 2 x 10(7) M-1) and for u-PA (Ka = 10(8) M-1) comparable to that of the mAbs obtained from the respective parental hybridomas. MA-FU1-74 did not influence the enzymatic activity of two-chain u-PA (tcu-PA) towards plasminogen or towards a chromogenic substrate. The complex of MA-FU1-74 with recombinant single chain u-PA (rscu-PA) or with tcu-PA (urokinase) enhanced the fibrinolytic potency of the plasminogen activator towards clotted human plasma 20-fold and 5-fold, respectively. In a hamster pulmonary embolism model, the rscu-PA/MA-FU1-74 complex had a 13- to 17-fold increased thrombolytic potency (percent lysis per mg/kg u-PA administered) relative to that of rscu-PA. The specific thrombolytic activity (percent lysis per microgram/ml steady state plasma level of u-PA antigen) of the complex was, however, not significantly different from that of rscu-PA. The complex of rscu-PA with the parental anti-u-PA mAb (MA-UK1-3) had only a 2-fold enhanced thrombolytic potency relative to that of rscu-PA and had a 5-fold decreased specific thrombolytic activity. The plasma clearance rates of the complexes of rscu-PA with both MA-FU1-74 and MA-UK1-3 were about 10-fold lower than that of rscu-PA. In a rabbit jugular vein thrombosis model, the rscu-PA/MA-FU1-74 complex had a 4-fold enhanced thrombolytic potency, an unchanged specific thrombolytic activity and 20-fold reduced plasma clearance. In both animal models, the rscu-PA/MA-FU1-74 complex did not cause more extensive systemic activation of the fibrinolytic system than rscu-PA. It is concluded that the bispecific anti-fibrin/anti-u-PA mAb MA-FU1-74 targets u-PA to the fibrin clot, resulting in a significantly enhanced thrombolytic potency of the plasminogen activator.
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PMID:Enhancement of clot lysis in vitro and in vivo with a bispecific monoclonal antibody directed against human fibrin and against urokinase-type plasminogen activator. 179 14

170 patients were treated with continuous infusion of epirubicin, mitoxantrone, carboplatin or 5-fluorouracil through an implanted venous access port with a portable infusion pump. A total of 440 cycles were given on an outpatient basis. The patients were instructed how to dissolve their drugs and to change the syringes. The complication rate was low. 10 patients developed a thrombosis of the subclavian vein, resulting in cessation of therapy in 5. Pulmonary embolism occurred twice, in 1 patient during a period of subclavian vein thrombosis. Needle dislocation occurred 6 times and catheter occlusion 20 times. Patency was restored with saline or urokinase. Local infection occurred 3 times and systemic infection only once. This technique is suitable for continuous infusion of different cytostatic drugs on an outpatient basis. Patients were able to prepare their drugs at home and the system can remain in situ for 3 weeks without increasing the complication rate.
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PMID:Continuous infusion of chemotherapy on an outpatient basis via a totally implanted venous access port. 182 78

The murine monoclonal antiplatelet antibodies MA-TSPI-1 (directed against human thrombospondin) and MA-PMI-2, MA-PMI-1, and MA-LIBS-1 (directed against ligand-induced binding sites [LIBS] on human platelet glycoprotein IIb/IIIa) were conjugated with recombinant single-chain urokinase-type plasminogen activator (rscu-PA) using the cross-linking reagent N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The conjugates (rscu-PA/MA-TSPI-1, rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, and rscu-PA/MA-LIBS-1), purified by immunoadsorption and gel filtration, were obtained with recoveries of 34% to 45%, with an average stoichiometry of 1.6 to 1.8 IgG molecules per rscu-PA molecule, and with unaltered specific activities and affinities. Preincubation of human platelet-rich plasma with rscu-PA/MA-PMI-2, rscu-PA/MA-PMI-1, or unconjugated rscu-PA resulted in partial inhibition of ADP-induced aggregation; 25% inhibition was obtained with 63 micrograms/mL rscu-PA and with 6 micrograms u-PA/mL rscu-PA/MA-PMI-2 or 1.2 micrograms u-PA/mL rscu-PA/MA-PMI-1. In an in vitro system composed of a 125I-fibrin-labeled platelet-rich human plasma clot immersed in normal human plasma, the conjugates had threefold to greater than 15-fold less fibrinolytic potency than unconjugated rscu-PA. The thrombolytic potency of rscu-PA/MA-PMI-1 and rscu-PA/MA-LIBS-1 was compared with that of rscu-PA and that of a control conjugate rscu-PA/MA-1C8 in a pulmonary embolism model in the hamster, using clots prepared from platelet-poor or platelet-rich human plasma. Lysis was measured 30 minutes after the end of a 60-minute intravenous infusion of the thrombolytic agents. rscu-PA, rscu-PA/MA-PMI-1, rscu-PA/MA-LIBS-1, as well as rscu-PA/MA-1C8 had comparable thrombolytic potencies (percent lysis per dose administered) towards platelet-poor human plasma clots. In contrast, the thrombolytic potency of rscu-PA/MA-PMI-1 and of rscu-PA/MA-LIBS-1 towards platelet-rich clots was 2.3- to 3-fold higher than that of rscu-PA (P less than .005) and fivefold to sevenfold higher than that of the control conjugate (P less than .01).
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PMID:Effect of chemical conjugation of recombinant single-chain urokinase-type plasminogen activator with monoclonal antiplatelet antibodies on platelet aggregation and on plasma clot lysis in vitro and in vivo. 183 Oct 57

Experience has shown that the bolus injection of streptokinase during resuscitation in case of fulminant pulmonary embolism considerably improves the prognosis. In the case presented here a 64-year old female patient with a fulminant pulmonary embolism was injected with 2 x 1,000,000 I.U. urokinase after 20 minutes of unsuccessful cardiopulmonary resuscitation. Ten minutes after the second injection the circulation could be stabilised by drugs only. The patient survived without any lasting damage. The mechanism of fibrinolysis during resuscitation is discussed. It is also possible to check the diagnosis during resuscitation using echocardiography or angiography. However, treatment must usually start immediately only on clinical diagnosis. Resuscitation in the case of a pulmonary embolism can even be successful after much longer than one hour. Contra-indications must be ignored in such cases. Side effects, which are usually haemorrhages, can as a rule be treated. In our opinion urokinase should be given by preference in the bolus injection during resuscitation. The exception to this is the primary operation during resuscitation. Pulmonary embolectomy is also possible after unsuccessful fibrinolysis.
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PMID:[Successful treatment of a fulminant pulmonary embolism using a high-dose bolus injection of urokinase during cardiopulmonary resuscitation]. 186 80

The recombinant chimeric plasminogen activator, rt-PA-delta FE/scu-PA-e, consisting of amino acids 1 to 3 and 87 to 274 of tissue-type plasminogen activator (t-PA) and amino acids 138 to 411 of single-chain urokinase-type plasminogen activator (scu-PA), has a markedly increased thrombolytic potency following its continuous intravenous infusion in animal models of venous thrombosis (Collen et al, Circulation, in press). In the present study, the thrombolytic potencies of intravenous bolus injections of rt-PA-delta FE/scu-PA-e, of recombinant t-PA (rt-PA), and of recombinant scu-PA (rscu-PA), given alone or in combination, were compared with those of intravenous infusions in a hamster pulmonary embolism model. Dose-dependent clot lysis was obtained in the absence of systemic activation of the fibrinolytic system and fibrinogen breakdown. In bolus injection experiments, the maximal rate of clot lysis, expressed in percent clot lysis per milligrams per kilogram compound administered, was 120 +/- 10 for rt-PA, 54 +/- 8 for rscu-PA, and 2,100 +/- 500 for rt-PA-delta FE/scu-PA-e (P less than .01 v rt-PA or rscu-PA). Comparative results with continuous infusion over 1 hour were 270 +/- 64, 99 +/- 18, and 1,500 +/- 250 (P less than .01 v rt-PA or rscu-PA) percent lysis per mg/kg compound infused for rt-PA, rscu-PA, and rt-PA-delta FE/scu-PA-e, respectively. Thus, rt-PA and rscu-PA are more potent when administered as an infusion than as a bolus, whereas rt-PA-delta FE/scu-PA-e is at least as potent when administered as a bolus. Combined bolus injections of rt-PA and rscu-PA had a 2.2-fold synergistic effect on clot lysis, but no synergism was observed with combined bolus injections or with combined infusions of rt-PA and rt-PA-delta FE/scu-PA-e, or of rscu-PA and rt-PA-delta FE/scu-PA-e. The present study thus shows that rt-PA-delta FE/scu-PA-e is much more potent for clot lysis than rt-PA or rscu-PA when administered as a bolus injection, but no synergistic interaction is observed between the chimera and either rt-PA or rscu-PA.
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PMID:Comparative thrombolytic properties of bolus injections and continuous infusions of a chimeric (t-PA/u-PA) plasminogen activator in a hamster pulmonary embolism model. 190 51


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