Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An epithelial cell line derived from the liver of a normal Buffalo rat (BRL) was transformed by Rous sarcoma virus (RSV). The RSV-transformed cells were separated into five clones (RSV-BRL1 through 5), which were morphologically different. RSV-BRL cells exhibited the following characteristics distinct from those of BRL cells: tumorigenicity, irregular cell arrangement, loose intercellular junction, growth in soft agar (anchorage-independent growth) except for RSV-BRL3 and 5, and loss of cell surface fibronectin. When BRL cells were cultured in the standard medium supplemented with the serum-free conditioned medium of RSV-BRL cells, the amount of the cell surface fibronectin decreased significantly. It was found that RSV-BRL cells secreted a proteinase capable of hydrolyzing the fibronectin, whereas BRL cells secreted hardly any of this proteinase. The fibronectin-hydrolyzing proteinase (FNase) could also hydrolyze plasma fibronectin added as an exogenous substrate. The hydrolysis of plasma fibronectin was inhibited by ethylenediamine tetraacetate, but stimulated by rho-chloromercuribenzoate and calcium ion. This indicates that FNase is a metallo-enzyme, but not a serine or thiol enzyme. In addition to the proteinase, RSV-BRL cells secreted plasminogen activator and a proteinase inhibitor which inhibited the activity of plasmin but not FNase.
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PMID:Transformation of rat liver cell line by Rous sarcoma virus causes loss of cell surface fibronectin, accompanied with secretion of metallo-proteinase that preferentially digests the fibronectin. 282 45

Left ventricular pump failure is today's main cause of in-hospital mortality from acute myocardial infarction and is directly dependent on infarct size. The first clinical attempts to preserve myocardium after acute infarction and to improve morbidity and prognosis by thrombolysis date from about twenty years ago. Through large multicenter studies and promising new agents, coronary thrombolysis has again attracted increased attention in the past two years. After a brief overview on the preconditions for successful thrombolysis, the efficacy, advantages, complications and problems of different thrombolytic agents and forms of administration are reviewed on the basis of the controlled studies published up to June 1986. They concern streptokinase by intracoronary and intravenous route, urokinase and the "clot specific" agents of the second generation, recombinant tissue-type plasminogen activator (rtPA) and anisoylated plasminogen streptokinase activator complex (APSAC) BRL 26921. Finally, questions that remain open even after successful thrombolysis with myocardial salvage are raised, and in particular the problem of reocclusion and postlytic treatment. In spite of justified hopes and the demonstrable feasibility of reopening a coronary artery, thrombolysis in acute myocardial infarction should not be used routinely as long as the beneficial long term effect is not definitely proven for patients, or at least for a known subgroup of patients, in terms of left ventricular function, mortality and morbidity following myocardial infarction.
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PMID:[Thrombolysis in acute myocardial infarct: prerequisites, current experiences and remaining problems]. 309 41

Fibrinolysis is a physiological process which aims at dissolving intravascular thrombi and is mediated by activation of plasminogen to plasmin. Streptokinase (SK) and urokinase (UK) are non-specific plasminogen activators. They have proved effective as thrombolytic agents, but their use is limited by the risk of haemorrhages due to systemic fibrinogenolysis. More fibrin-specific drugs have recently been developed. One is a tissue plasminogen activator (t-PA), the other is a urokinase precursor (pro-UK), also called single chain urokinase plasminogen activator (scu-PA). Genetic engineering techniques have resulted in the large-scale production of a "recombinant t-PA" (rt-PA) and a "recombinant scu-PA" (r scu-PA) for therapeutic use, notably in acute myocardial infarction. In vitro, these two drugs exhibit a thrombolytic activity that is equal to, or greater than that of SK or UK. In vivo, their fibrinogenolytic effect is less pronounced, and their thrombolytic effect greater than those of SK or UK. "Acyl-enzymes" have more recently emerged. These are inactive acylated SK-plasminogen complexes which progressively become effective in plasma after deacylation. So far, the most extensively studied of these complexes is BRL 26921 (anisoylated plasminogen streptokinase activator complex, or APSAC) which is administered by bolus intravenous injection. It is more thrombolytic than SK but produces systemic fibrinogenolysis to an equivalent degree. Injected intravenously (by infusion or bolus) during the first hours of a coronary infarction these three new thrombolytic agents have proved effective in promoting coronary reperfusion, with an early coronary patency rate of 70-75%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[New thrombolytic agents in myocardial infarction]. 312 22

A procedure is described for the establishment of experimental clots, aged in vivo for 72 hr, in the jugular vein of beagle dogs. Two acylated derivatives of streptokinase-human (lys) plasminogen activator complex with greatly differing deacylation rates under physiological conditions were compared as thrombolytic agents in the model. These were BRL 26921 (deacylation half-life, 40 min) and BRL 33575 (deacylation half-life c. 17 hr). The pharmacokinetic clearance rate of BRL 33575 from the circulation was studied and gave a clearance half-life of about 7 hr. BRL 33575 was found to be the superior agent in lysing 72 hr aged clots, being effective at a single bolus dose of 420 micrograms/kg or in three equal divided doses of 140 micrograms/kg given at 12 hr intervals. The single dose regime gave moderate systemic plasminogen activation, and the effect was significantly reduced with the divided dose regime. Infusion of freshly formed streptokinase-human plasminogen activator complex at 420 micrograms/kg over 15 hr gave little thrombolysis despite marked systemic plasminogen activation.
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PMID:Acylated derivatives of streptokinase-plasminogen activator complex as thrombolytic agents in a dog model of aged venous thrombosis. 388 35

The role of thrombus-binding in the fibrinolytic response to the acylated streptokinase.plasminogen activator complex, BRL 26921, has been examined using human plasma clots, radiolabelled with 125I-fibrin, in vitro. When clots were briefly exposed to BRL 26921, washed and returned to homologous plasma, lysis continued for up to 3 hours and attained approximately 25% of that lysis achieved by incubating with BRL 26921 for 5 hours. This continuing lysis was potentiated by return of exposed clots to alpha 2-antiplasmin-depleted plasma, or buffer and is attributed to an initial uptake of BRL 26921 rather than the binding of exogenous plasmin that was observed for streptokinase and high concentrations of urokinase. The sustained lysis is not explained by transfer of loosely-associated surface material or by dissociation of agent from the clot with reuptake from a dilute systemic pool. The response can be attributed, at least in part, to specific fibrin binding, mediated by kringles 1-4, for a low-molecular weight plasminogen (Val442) variant was less active.
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PMID:Induction of a sustained fibrinolytic response by BRL 26921 in vitro. 389 61

In view of current interest in the possibility of rapid, high-dose administration of thrombolytic agents by the intravenous route in patients with coronary thrombosis (AMI), a study of this technique was carried out in the dog. Streptokinase-(human) plasmin activator complex (SK-Pm) and BRL 26921 (p-anisoylated streptokinase-(human) plasminogen activator complex) were each given at equivalent doses (28,500 IU/kg and 800 micrograms/kg respectively) to groups of beagle dogs by rapid injection over 10 sec and their effects on blood pressure, plasmin formation and kallikrein production were compared over the next 3h. SK-Pm produced, within 1-3 min, a pronounced hypotensive effect that was kinetically related to a rapid and steep rise in systemic plasmin and kallikrein concentrations. BRL 26921 had no hypotensive effect, the rise in plasmin production was slower and the rate and extent of kallikrein formation was significantly less than in the SK-Pm group.
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PMID:Comparison of the hypotensive effects of streptokinase-(human) plasmin activator complex and BRL 26921 (p-anisoylated streptokinase-plasminogen activator complex) in the dog after high dose, bolus administration. 639 Jul 76