Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.68 (tissue plasminogen activator)
 11,311 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A consumption coagulopathy syndrome has frequently been reported in association with some cases of acute nonlymphoblastic leukemia (ANLL) and mainly in acute promyelocytic leukemia (M3). Eighteen cases of ANLL have been studied on admission, before chemotherapy was started. Levels of antithrombin III (AT-III), protein C (PC), protein S (PS), thrombin-antithrombin complex (T-AT-III), tissue plasminogen activator, plasminogen (Pg), alpha-2-antiplasmin (alpha-2-AP), D-dimer (DD) and fibrinogen (Fg) were determined. The results showed normal levels of AT-III and PS, decreased levels of PC, alpha-2-AP, Pg and Fg in some cases, and an elevation of DD and T-AT III complex in almost all patients. There was a continuous evolution of data from M1 cases in which only slight alterations were seen up to M3 cases where all those pathologic data were observed.
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PMID:A continuous spectrum of hypercoagulability exists in acute nonlymphoblastic leukemia. 128 98

We investigated heparin cofactor II (HC II) levels and their relationship to other haemostatic factors in the elderly in comparison with antithrombin III (AT III). We measured plasma HC II activity levels in 166 subjects aged from 61 to 99 years using a chromogenic method. HC II levels (94.4 +/- 18.5%) in the healthy elderly subjects were significantly (p less than 0.001) lower than in 40 healthy adult controls under 60 years of age (mean age: 51.5 years; 111.6 +/- 21.2%). HC II levels in the elderly subjects decreased further with age (r = 0.308, p less than 0.001) and the extent of the decrease was more marked than that for AT III (r = 0.179, p less than 0.05). There was no significant sex difference in HC II levels in the elderly. HC II levels correlated significantly with AT III levels and with acute phase reactants including sialic acid, fibrinogen, and PAI-1. HC II levels also correlated with factor VII, plasminogen, alpha 2-plasmin inhibitor, serum lipid, pseudocholinesterase, and albumin levels. These correlations were also found for AT III except active PAI-1 and tPA-PAI-1 complexes, but the correlations with acute phase reactants were stronger for HC II than AT III. We divided 154 elderly subjects into 4 groups by their pseudocholinesterase and albumin levels to estimate the effect of nutritional status on antithrombin activity in the elderly. HC II levels were normal in the elderly subjects with a good nutritional state (103 +/- 18%), but were significantly decreased in those with malnutrition (85 +/- 15%, p less than 0.001). AT III levels also showed the same tendency. These results indicate a decrease in the reserve capacity to inhibit thrombin generation at sites of atherosclerosis in response to trigger events. The deficiency of two major antithrombin factors in the elderly may indicate a tendency to thrombosis, especially in individuals with malnutrition. When considering the clinical significance of HC II, several other parameters, including age, nutritional status, hepatic synthetic ability, and the presence or absence of acute phase reaction should also be assessed.
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PMID:Heparin cofactor II deficiency in the elderly: comparison with antithrombin III. 138 49

In order to clarify the effect of hemodialysis (HD) on the fibrinolytic system, fibrinolytic activity was evaluated in 27 patients undergoing regular hemodialysis treatment (RDT) using new parameters including plasma alpha 2-plasmin inhibitor (alpha 2 PI), alpha 2-plasmin inhibitor-plasmin complex (alpha 2 PIC), cross-linked fibrin degradation products (XL-FDP), tissue plasminogen activator (t-PA) activity, t-PA antigen and plasminogen activator inhibitor-1 (PAI-1) antigen. Predialysis baseline levels of plasminogen and alpha 2PI activity in RDT patients were significantly lower and those of alpha 2PIC were significantly higher than normal control values. During a single HD session, alpha 2PIC exhibited a continuous, significant increase reaching about 180% of initial values by the end of HD. alpha 2PI activity was significantly decreased at the end of the HD, though there were no significant changes in plasminogen activity during HD. Predialysis baseline levels of XL-FDP in RDT patients were significantly higher than normal control values. No significant changes in XL-FDP were observed during HD. Both t-PA activity and t-PA antigen significantly increased during HD, and PAI-1 antigen significantly decreased during HD. Von Willebrand factor (vWF) antigen in plasma, which is regarded as reflecting a release reaction by vascular endothelial cells to certain stimuli, also significantly increased during HD. However, neither vWF antigen nor t-PA antigen was increased by heparin administration alone. The changes in alpha 2PI and alpha 2PIC levels suggest that fibrinolytic activity is slightly higher in RDT patients and is even higher during HD.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enhanced fibrinolytic activity during the course of hemodialysis. 138 98

In our previous study (Adv. Exp. Med & Biol., 247B. 569. 1989, 198B. 41. 1986, blood & vessel, 17: 51. 1986), we reported on the mechanism of coagulation-fibrinolysis system and kallikrein-kinin system in the utero-placental circulation during normal pregnancy, labor and puerperium. The samples were collected from the uterine artery (UA), uterine vein (UV) and peripheral vein (PV). In this study, we tried to elucidate the mechanism of coagulation-fibrinolysis with relation to kks by measuring of Thrombin/Antithrombin III complex (TAT), tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI) complex (tPA.PAI.C), active plasminogen activator inhibitor 1 (active PAI), alpha 2-plasmin inhibitor/plasmin complex (PIC). In 20 normal pregnant women, the levels of TAT, tPA.PAI.C and active PAI significantly increased the first trimester (TAT 4.31 +/- 2.05 ng/ml, tPA.PAI.C 39.52 +/- 17.34 ng/ml, active PAI 39.58 +/- 15.29 ng/ml, n = 20 M +/- SD P < 0.001) to the third trimester (TAT 6.39 +/- 1.93 ng/ml, tPA.PAI.C 57.94 +/- 30.80 ng/ml, active PAI 304.24 +/- 148.64 ng/ml, n = 20 M +/- SD P < 0.001) as compared with those of non-pregnant women (TAT 1.60 +/- 0.89 ng/mg, tPA.PAI.C 11.72 +/- 4.59 ng/ml, active PAI 11.53 +/- 7.48 ng/ml, n = 16 M +/- SD). In utero-placental circulation, the levels of TAT significantly increased (TAT 22.12 +/- 20.03 ng/ml n = 20 M +/- SD P < 0.001) in UV, and tPA.PAI.C and PIC. markedly increased (tPA.PAI.C 93.38 +/- 56.05 ng/ml, PIC 1.03 +/- 0.94 micrograms/ml n = 20 M +/- SD P < 0.02) in UV, but active PAI markedly decreased (active PAI 244.18 +/- 87.55 ng/ml n = 20 M +/- SD P < 0.02) as compared with those in PV (TAT 6.1 +/- 2.09 ng/ml, tPA.PAI.C 59.34 +/- 18.99 ng/ml, PIC 0.49 +/- 0.24 micrograms/ml, active PAI 349.14 +/- 157.34 ng/ml, n = 20 M +/- SD). These findings suggest that the significant increase in those complexes in UA has produced a deposition of fibrin clots in the area in contact with utero-placental blood vessel, although the marked increase in tPA.PAI.C and PIC incompletely inhibited the fibrinolytic activity of tPA by the active PAI. The kks shows a consumption of prekallikrein, LMW-kininogen and HMW-kininogen, and an overproduction of kinin in UV.
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PMID:Studies on blood coagulation-fibrinolysis system regarding kallikrein-kinin system in the utero-placental circulation during normal pregnancy, labor and puerperium. 146 39

This study was conducted to compare the thrombolytic effect of a novel modified tissue plasminogen activator, E6010, with that of recombinant human tissue plasminogen activator (t-PA), administered by single intravenous bolus injection in pigs with occlusive coronary thrombosis. Thrombosis was induced by electrical stimulation of the intimal surface of the left circumflex coronary artery. Coronary blood flow velocity and hemodynamic parameters were observed for 1 hr after complete cessation of coronary flow. Ten minutes after heparin injection (300 U/kg), E6010, t-PA or placebo was intravenously administered as a bolus. E6010 at 0.2 and 0.4 mg/kg caused recanalization of the occluded coronary artery in 1 of 6 and 5 of 5 pigs, respectively. The time to recanalization after 0.4 mg/kg of E6010 was 22 +/- 11 min (mean +/- S.E.M.). t-PA (0.4 mg/kg) caused recanalization in only 1 of 5 pigs. Recanalization did not occur in any of the 6 animals administered placebo. Plasma clearance of E6010 was smaller than that of t-PA (4.9 +/- 0.3 vs. 9.4 +/- 3.8 ml/min/kg). There were no significant differences in plasma levels of fibrinogen, alpha 2-plasmin inhibitor and plasminogen among the placebo, E6010 and t-PA groups. These results suggest that the slower clearance of E6010 from plasma contributes to the effective thrombolytic action of E6010 following single intravenous bolus injection.
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PMID:Thrombolytic effects of a novel modified tissue plasminogen activator, E6010, on coronary thrombosis in the pig. 151 78

A series of fucoidan [sulfated poly(L-fucopyranose)] derivatives were prepared by chemical sulfation and desulfation, and they were tested for their abilities to stimulate tissue plasminogen activator (t-PA)-catalyzed plasminogen activation, clot lysis, and the inhibition of fibrin polymer formation. The magnitude of their activities was dependent upon the degree of sulfation. A striking feature of the sulfated fucoidan was that, unlike heparin, it stimulated t-PA-induced plasma clot lysis by protecting plasmin activity from alpha 2-plasmin inhibitor and decreased the rate of fibrin polymer formation. The inhibition of hyaluronic acid-mediated enhancement of fibrin clot formation was also observed with the fucoidan derivative. We also showed that highly sulfated fucoidan prevents significantly endotoxin-induced hepatic vein thrombosis in the hyperlipemic rat model. The present results are the first to describe the fibrinolytic and anticoagulant activities of fucoidan, and thus may provide useful clues for the development of an ideal thrombolytic agent.
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PMID:Fibrinolytic and anticoagulant activities of highly sulfated fucoidan. 153 20

The effects of physical training on hemostatic parameters were evaluated in 56 postmyocardial infarction (MI) patients before and after one month of systematic physical training and in 30 control post-MI patients, who did not undergo such training. There were no significant changes in prothrombin time (PT) and alpha 1-antitrypsin (alpha 1AT) at the beginning and end of the study in either group. Levels of fibrinogen, Factor VIII: C (VIII:C) and von Wildebrand antigen (vWf:Ag), and activities of ATIII and plasminogen (Plg) were significantly decreased in the group with physical training (p less than 0.05), while values were unchanged in the control group. Hematocrit, platelet counts, and alpha 2-plasmin inhibitor (alpha 2PI) activities also decreased in the physical training group (p less than 0.05). In contrast, these variables increased in the control group (p less than 0.05). Activated partial thromboplastin time (aPTT) tended to be prolonged in the group with physical training, while it was shortened in the control group. In a subset of 20 patients with physical training, resting levels of plasmin-alpha 2PI complex (PIC), thrombin-antithrombin III complex (TAT), protein-C (P-C:Ag), plasminogen activator inhibitor-1 (PAI-1), VII:C, and P-C activities had significantly decreased after one month of physical training (p less than 0.05), although tissue plasminogen activator activities remained unchanged. Physical training appeared to suppress coagulability as indicated by the decrease in fibrinogen, VIII:C, vWf:Ag, VII:C, and TAT, and prolongation of aPTT. The decrease in plasminogen, t-PA:Ag, alpha 2PI, PAI-1, and PIC after physical training may result from the decreased coagulability. In conclusion, physical training appears to induce a suppression of the coagulation system in patients in the recovery phase of MI.
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PMID:Blood coagulability and fibrinolytic activity before and after physical training during the recovery phase of acute myocardial infarction. 162 56

A functional assay for equine plasminogen was established, using urokinase as the activator, a synthetic chromogenic substrate, a computer-assisted centrifugal analyzer, and acidified/neutralized plasma. One documented effect of plasma acidification appears to be inactivation of alpha-2-antiplasmin. Intra- and interassay precision testing yielded coefficients of variation of 4.1% (n = 10) and 5.6% (n = 26), respectively. Plasminogen was stable in equine plasma stored up to 1 week at 4 C and up to 5 months at -70 C. Plasminogen in nonacidified equine plasma was not activated by urokinase, streptokinase, tissue plasminogen activator, or tissue plasminogen activator plus soluble fibrin. Streptokinase also failed to activate plasminogen in acidified/neutralized equine plasma.
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PMID:Chromogenic assay for equine plasminogen. 169 46

A hybrid plasminogen activator consisting of the "A" chain of plasmin linked to the "B" chain of rt-PA was inhibited in vitro in human and guinea pig plasmas 4 to 5-fold more rapidly than its parent activator, two-chain t-PA. Using zymographic and autoradiographic techniques together with the use of immunodepleted plasma the major inhibitor was identified as alpha-2-antiplasmin. The pharmacokinetic profile of the hybrid in guinea pigs was determined by two different methods: disappearance of fibrinolytic activity and removal of radiolabelled hybrid from the circulation. Fibrinolytic activity was cleared rapidly via inhibitory mechanisms, whilst radiolabelled material was cleared considerably more slowly due to the formation of hybrid-inhibitor complexes. When the active site of the hybrid was reversibly acylated inhibitory mechanisms were evaded and a prolonged pharmacokinetic profile of activity was observed.
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PMID:Interaction of a plasmin A-chain/t-PA B-chain hybrid enzyme with plasma inhibitors in vivo and in vitro. 169 16

In disseminated intravascular coagulation (DIC) with acute promyelocytic leukemia (APL) in the absence of severe infection, marked fibrinolysis was noted in comparison with normal levels of antithrombin III, which is a major inhibitor of the coagulation system. Increased plasminogen activator inhibitor-1 (PAI-1) antigen levels in plasma from patients with septicemia decreased the ratio of the plasma clot lysis rate induced by an anti-alpha 2-plasmin inhibitor monoclonal antibody to the tissue-type plasminogen activator (t-PA) concentration. This decrease was not as prominent in plasma from patients with DIC, especially those with APL. To explore the character of PAI-1 in these plasmas, we measured the specific activity of PAI-1 by determining the ratio of active PAI-1 antigen to t-PA-unbound PAI-1 antigen. To calculate the amount of active PAI-1 antigen, the amount of t-PA/PAI-1 complex before and after the addition of a fixed amount of t-PA to the sample was measured by a sandwich solid-phase enzyme-linked immunosorbent assay using anti-PAI-1 and anti-t-PA monoclonal antibodies. The assay to measure total PAI-1 antigen used three monoclonal anti-PAI-1 antibodies and had similar sensitivities to free active, latent, vitronectin-bound and t-PA-bound PAI-1. The specific activity of PAI-1 decreased in patients with DIC (43.7% +/- 30.6%) and in DIC cases with APL (10.3% +/- 6.0%) in comparison to patients with septicemia (83.7% +/- 20.2%) or normal controls (85.8% +/- 27.3%). In DIC associated with APL, degraded forms of PAI-1 were detected in plasma by immunoblotting. These results suggest that a decrease in the specific activity of PAI-1 and an increase in secondary fibrinolysis result in a hyperfibrinolytic state in DIC patients with APL.
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PMID:The specific activity of plasminogen activator inhibitor-1 in disseminated intravascular coagulation with acute promyelocytic leukemia. 170 94


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