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

Since thromboembolic complications in transplanted patients are generally attributed to combined abnormalities in platelets and coagulo-lytic system, some hemostatic parameters tPA (tissue plasmogin activator):Ag and activity, its inhibitor-PAIAg and activity, tPA/PAI, thrombin-antithrombin (TAT) and plasmin-antiplasmin complexes (PAP), urokinase-uPA, euglobulin clot lysis time-ECLT, fibrinogen, plasminogen, protein C activity, D-dimer, prothrombin fragments1+2 (F1+2), fibrin monomers, fibronectin, lipoprotein-a, and von Willebrand factor(vWF), were evaluated using commercially available kits. The studies were performed on kidney transplant recipients treated with CsA, azathioprine and prednisone (n=21), and healthy volunteers (n=21). ECLT was significantly prolonged in kidney transplant recipients together with a rise in F1+2,lipoprotein-a, fibrinogen, fibronectin, and vWF when compared with controls. The TPA level was lower, whereas the PAI level was higher in kidney transplant recipients when compared with controls. In conclusion, CsA-treated kidney transplant recipients show evidence of pronounced impairment in fibrinolysis and endothelial damage in comparison with healthy volunteers.
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PMID:The coagulo-lytic system and endothelial function in cyclosporine-treated kidney allograft recipients. 882 84

DNA damage results from a wide variety of external agents such as chemicals and radiation. The consequences of exposure to agents that damage DNA have been traditionally studied from the perspective of cell survival and mutagenesis. Mutations are late endpoints of DNA damage. Cells respond to the earlier stages of DNA damage by inducing the expression of several genes, including those specific of the nature of the lesion. These early transcriptional responses are likely to predetermine the later fate of the damaged cell. Genes activated during this early response include those involved in DNA repair, replication, and growth control. We are interested in the transcriptional mechanisms by which cells respond to DNA damaging agents. To facilitate the measurement of gene induction, we used seven different reporter constructs integrated stably into the RKO cell line derived from a human colon carcinoma. These constructs were derived from promoters and/or response elements isolated from genes associated with DNA damage responses in human cells, and were fused to the bacterial reporter gene, choramphenicol acetyl transferase (CAT). The cell lines generated in this manner contain the promoters and/or response elements representing DNA polymerase beta, p53, gadd (growth arrest and DNA damage) 45 and 153, c-fos, TPA response element, and tissue-type plasminogen activator. These recombinant cell lines were assembled in a 96-well microtiter plate permitting their simultaneous exposure to compounds and subsequent CAT protein measurement. This assembly has been designated the CAT-Tox (D) assay. These cell lines were exposed to different classes of DNA damaging agents including those which covalently join bases to form dimers (e.g., UVC irradiation), generate DNA adducts by alkylation (e.g., methylmethane sulfonate [MMS], ethylmethane sulfonate [EMS], N-methyl-N-nitro-N-nitrosoguanine [MNNG], dimethylnitrosamine [DMN]), cross-link DNA (e.g., mitomycin C), and inhibit DNA replication by intercalative (e.g., actinomycin D) and nonintercalative (e.g., hydroxyurea) mechanisms. The transcriptional responses were measured as a function of the accumulation of CAT protein using antibodies against CAT protein in a standard ELISA. Endogenous cellular responses were evaluated for a number of the genes represented in the assay at both the mRNA and protein levels by Northern and Western blot analysis, respectively. These data corroborate the stress-induced responses measured by CAT ELISA in the CAT-Tox (D) assay, demonstrating the usefulness of this assay as a rapid and sensitive method for detection of DNA damaging agents in human cells.
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PMID:Stress responses to DNA damaging agents in the human colon carcinoma cell line, RKO. 895 Mar 45

The following factors of fibrinolysis: tissue plasminogen activator (t-PA) and tissue plasminogen activator inhibitor-1 (PAI-1) play an important role in patients after trauma. Their possible mechanisms in head-injured patients remain unknown. We studied the maintenance of those markers of fibrinolysis in the plasma and cerebrospinal fluid of 19 patients after severe head injury (initially GCS less than 8 p) without intracranial haematoma. We measured changes of the level of t-PA antigen and PAI-1 activity in days 0-3, 4-6 and later. T-PA antigen level in the plasma was higher than normally (4-8 ng/ml). T-Pa was present in the cerebrospinal fluid, but its level reached only 30% of the plasma level. In the days following injury the t-PA antigen level decreased. The PAI-1 activity in the plasma was normal (0-15 IU/ml). However, its activity in csf was high and reached, 80% of the plasma level and systematically increase in the following days particularly in patients who died. PAI-1 activity can be connected with the presence of damaged brain tissue and its necrosis and its increase can be a marker of poor prognosis.
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PMID:[Tissue plasminogen activator (T-PA) and tissue plasminogen activator inhibitor (PAI-1) in patients after head injury]. 896 77

The role of heparin in conjunction with thrombolytic therapy for the management of patients with acute myocardial infarction continues to be controversial. Many issues, including the possible benefits and risks of this therapy, are unresolved. Administration of high-dose subcutaneous heparin in the presence of thrombolytic therapy results in a significant mortality reduction during the treatment period of 55 lives saved per 10,000 patients treated (p < 0.01). At 35 days mortality is not significantly decreased by 22 lives and 18 nonfatal infarctions, at a cost of 32 transfusions and 6 strokes (half of which result in full recovery) per 10,000 patients treated. There have been fewer than 1250 patients randomized in trials comparing intravenous heparin with no heparin in patients receiving thrombolytic therapy and aspirin. These trials are too small to draw reliable conclusions, although several trials have suggested that intravenous heparin is beneficial for maintaining patency after t-PA therapy. In the the Global Use of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) trial, patients receiving streptokinase were randomized to receive either delayed subcutaneous heparin or intravenous heparin. There were no differences in clinical endpoints. However, despite 36% crossover to intravenous heparin among patients randomized to receive subcutaneous heparin with streptokinase, patency of the infarct-related artery was 17% higher (84% vs. 72%, p < 0.05) at 5-7 days in patients randomized to receive intravenous heparin and streptokinase. This significant difference could potentially translate into an important effect on long-term prognosis. Therapy for acute myocardial infarction should include aspirin and a thrombolytic agent for patients without contraindications. Based on the current evidence, it is reasonable to also administer intravenous heparin with either streptokinase or TPA.
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PMID:Is heparin of value in the management of acute myocardial infarction? 914 Jun 86

Proteolytic destruction of basement membrane and tumor surrounding is a prerequisite of invasion and metastasis. In 587 frozen samples of malignant and nonmalignant tissue of breast, uterus, vulva, and ovary, levels of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) were examined with enzyme-linked immunosorbent assay (ELISA) and cathepsin D (cath D) with radioimmunoassay. UPA, PAI-1 and cath D were raised in malignant tissue with significantly higher levels in breast cancer (uPA, PAI-1) and ovarian cancer (cath D). TPA levels were lower in malignant tissue. In 393 primary breast cancer samples, uPA, PAI-1, and cath D were not related to other prognostic factors, whereas tPA levels were significantly raised in prognostic more favorable carcinomas. Over a follow-up period up to 46 months (median 30 months) the log-rank test showed in the whole group of breast cancer patients a significantly higher rate of relapse (p < 0.05) and death (p < 0.001) with tPA levels < 2.5 ng/mg. PAI-1 levels > 3 ng/mg were associated with shorter overall (p < 0.02; p = 0.01), disease-free (p < 0.008; p < 0.01), and metastasis-free (p < 0.04; p = 0.005) survival in all patients and in the node-negative subgroup, respectively. Higher uPA and cath D levels were not associated with rate of relapse or death over this follow-up period. The prognostic value of tumor-associated proteases could be of interest also in ovarian and cervical cancer.
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PMID:Protease levels in breast, ovary, and other gynecological tumor tissues: prognostic importance in breast cancer. 930 48

Women with premature menopause are at high risk for vascular compications associated with thrombogenesis and atherogenesis. The use of hormone-replacement therapy (HRT), however, may protect against these complications. Hemostatic abnormalities and endothelial function are closely related to the processes of thrombogenesis and atherogenesis. The purpose of the study was to evaluate the effects of premature menopause on markers of hemostasis, platelet function, and endothelial function and the effects of starting HRT. This is a prospective longitudinal study of premenopausal women undergoing surgical menopause in whom estrogen HRT is started. We measured sequential changes in plasma levels of the hemostatic factors (fibrinogen, fibrin D-dimer, and plasminogen activiator inhibitor [PAI]), markers of platelet function (soluble leukocyte adhesion molecule P-selectin) and endothelial function (von Willebrand factor [vWf], soluble thrombomodulin [sTM], and tissue plasminogen activator [TPA]), and serum lipid levels, including lipoprotein A. Twenty-seven premenopausal women (mean age 43.6 +/- 6.5 years) undergoing hysterectomy and bilateral salpingo-oophrectomy were studied. In the postsurgical menopausal state (visit 2), there was a significant elevation in sTM levels (paired Wilcoxon test, p = 0.008). There was also a trend toward higher median soluble P-selectin, PAI, and mean TPA levels and lower vWf levels. After 6 weeks of HRT (visit 3), there was a significant reduction in mean vWf (paired Wilcoxon test, p = 0.0026), sTM (p = 0.039), and TPA levels (p = 0.02) compared with premenopausal levels. There were no significant changes in plasma fibrinogen, fibrin D-dimer, and PAI levels at visit 2 or visit 3 compared with premenopausal levels. There was a significant increase in serum lipoprotein A (paired Wilcoxon test, p = 0.008), cholesterol, and triglyceride levels after surgical menopause (paired t test, p < 0.01). Lipoprotein A and cholesterol levels after HRT (visit 3) were not significantly different from prehysterectomy levels, although triglyceride levels were increased further. HRT results in a significant reduction in vWf, sTM, and TPA levels, suggesting beneficial effects on endothelial function and atherogenesis. Although there was a significant increase in serum lipoprotein A and cholesterol levels after surgical menopause, lipoprotein A and cholesterol levels after HRT were not significantly different from presurgery levels. These observations are consistent with the beneficial effects of HRT in cardiovascular hemodynamics and cardiovascular disease.
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PMID:Effects of hormone-replacement therapy on hemostatic factors, lipid factors, and endothelial function in women undergoing surgical menopause: implications for prevention of atherosclerosis. 935 46

Different immunosuppressive agents, in particular OKT3, have been implicated as causative factors in the risk for renal thrombosis in the period immediately after kidney transplantation. Also, in different types of vascular surgery, a state similar to hypercoagulation has been reported. To assess the extent to which OKT3, cyclosporine A (CsA), and surgery itself affect coagulation and fibrinolysis, a study was conducted of 20 patients divided into two groups: group A, 10 patients received OKT3 (first dose during the induction of anesthesia); and group B, 10 patients received CsA (first dose at least 2 hours before transplantation). Basal determinations and determinations at 2, 4, and 24 hours after the induction of anesthesia were made. No differences were found between the groups with respect to the clinical and usual coagulation parameters. The following were studied in both groups: (1) markers of coagulation activity (prekallikrein [PKK] levels and formation of thrombin-antithrombin complexes [TATc]), (2) inhibitors and suppressors of hemostasis (antithrombin III [AT-III] and protein C [PC] activity), (3) markers of fibrinolysis activation (levels of plasminogen [PLG] and of alpha2-antiplasmin [alpha2-APL]), and (4) markers of endothelial damage (tissue plasminogen activator [TPA] and thrombomodulin [TMD]). In both groups, an important formation of TATc was observed early, together with a decrease in PKK levels and consumption of both AT-III and PC, which reached their lowest levels at 24 hours. This points to an activation of coagulation through the intrinsic route and a secondary consumption of hemostasis inhibitors, both possibly caused by surgery. A consumption of PLG and alpha2-APL was also observed, reflecting stimulation of the fibrinolytic system and a physiological response to the activation of coagulation. A greater release of endothelial TPA was only observed in the patients receiving OKT3 (P < 0.0001), possibly signaling endothelial activation. It is concluded that surgical stress could be the major factor triggering the alterations seen in hemostasis and their possible consequences.
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PMID:Changes in coagulation and fibrinolysis in the postoperative period immediately after kidney transplantation in patients receiving OKT3 or cyclosporine A as induction therapy. 977 17

The GUSTO trial and an Australian consensus meeting in 1993 led to the recommendation that recombinant tissue plasminogen activator (r-TPA) was the preferred thrombolytic in patients with acute myocardial infarction (AMI) and ST segment elevation under the age of 75, whose infarction was anterior, who could be treated within four hours of the onset of symptoms and who did not have a contraindication to thrombolysis. Available data suggest that streptokinase (SK) should not be administered in a patient who has received this drug three days or more previously. New data on the risks of stroke confirm that the use of r-TPA is associated with a higher risk of intracranial haemorrhage than SK, and those with a high risk profile for intracranial haemorrhage (hypertension and advanced age) should receive SK rather than r-TPA. It may be justified to give r-TPA to any patient with a large infarct regardless of location, within four hours of the onset of infarction in an attempt to achieve TIMI flow grade 3 (complete) reperfusion, reduce mortality and improve left ventricular function and clinical outcomes. The focus for the future will be on how to treat more patients earlier with thrombolytic agents, rather than the choice of agent.
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PMID:Alteplase (r-TPA) vs streptokinase. 977 31

Myocardial infarction is the result of thrombotic coronary artery occlusion. Although present-day thrombolytics have major value by increasing the frequency of reopening of arteries responsible for myocardial infarction, by preserving myocardial function and, thereby, significantly reduce mortality. Nevertheless, they are subject to the following limitations: 1) excellent arterial partency is only obtained in 50% of cases: 2) reocclusion occurs in 5 to 10% of cases; 3) severe complications such as cerebral haemorrhage are observed in about 0.5% of cases. Therefore, the search to improve thrombolytic agents is intense. This article reports the recent advances in concept and production of new thrombolytic agents. The most recent results concern the production of mutants of T-PA (tissue plasmogen activator). Of these mutants, the reteplase (r-PA) has already received authorization for its commercialisation. Other t-PA mutants under development (phase 3) include TNK-t-PA and lanoteplase. Over the last few years, there has been renewed interest in staphylokinase. The results of the initial clinical trials with this agent have also been reported. Paradoxically, the mode of action of thrombolytic agents has an inherent pro-thrombotic effect. This explains some of the interest for anti-thrombotic agents as an adjuvant treatment of thrombolysis. The initial results of the association of thrombolytics with new glycoprotein IIb/IIIa platelet inhibitors and anti-thrombin agents are reported.
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PMID:[New thrombolytic agents in myocardial infarction]. 1032 49

The purpose of this article is to report four patients with massive pulmonary embolism treated with percutaneous catheter and guidewire fragmentation and local administration of recombinant tissue plasminogen activator (r-TPA). Four patients with massive pulmonary embolism initially underwent pulmonary angiography. Thrombus fragmentation was performed with both standard angiographic guidewires and catheters followed by local infusion of 41-200 mg of r-TPA. Pulmonary angiography was repeated after treatment. All patients survived with improvement in their clinical status and eventual discharge from hospital. Angiography in all patients post treatment demonstrated improvement in pulmonary perfusion (mean Miller score before treatment 22.5; mean Miller score after treatment 5.75). No patient had a significant complication. Mechanical fragmentation of the thrombus followed by local infusion of r-TPA was an effective treatment for massive pulmonary embolism in these four patients with no significant complications.
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PMID:Percutaneous catheter and guidewire fragmentation with local administration of recombinant tissue plasminogen activator as a treatment for massive pulmonary embolism. 1037


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