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)

The duration and amount of analgesics required were investigated in 67 patients with myocardial infarction treated with intravenous recombinant tissue-type plasminogen activator (rtPA) or placebo in a randomized double-blind trial. Infusion of rtPA (100 mg)/placebo was started within 5 h after the onset of symptoms, and the requirement for analgesics during the following 48 h was recorded. Sixty-seven per cent of the 30 rtPA-treated patients required analgesic treatment for less than 6 h, compared to 38% of the 37 patients in the placebo group (P = 0.04). During the study period, patients in the rtPA group used the equivalent of 5.3 mg (median value) intravenous morphine, which was significantly less than the 11.2 mg used in the placebo group (P = 0.04). In conclusion, the present study suggests that early thrombolysis with intravenous rtPA reduces the amount and duration of analgesic treatment required by patients with myocardial infarction.
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PMID:Early thrombolytic treatment reduces analgesic requirement in patients with myocardial infarction. 190 Oct 76

Baseline plasminogen activator inhibitor (PAI) levels were examined for their influence on the responses to thrombolysis with recombinant tissue plasminogen activator (rt-PA) administered for acute myocardial infarction during the Thrombolysis and Myocardial Infarction (TAMI)-I study. Baseline PAI activity was 19 +/- 21 IU/ml (normal less than 5 IU/ml) and baseline PAI-1 antigen 54 +/- 53 ng/ml (normal 27 +/- 16 ng/ml), confirming previous findings of elevated PAI levels during acute myocardial infarction. Among clinical outcomes, lower PAI-1 antigen levels correlated weakly with greater patency at the 90 min angiogram. Thus, high baseline plasma PAI-1 levels may be detrimental to reperfusion with t-PA. There was no correlation with other major in-hospital clinical outcomes including reocclusion at the 7-10 day angiogram, survival to discharge, or bleeding. During the follow up period of 2.0 +/- 0.4 years, no relationship between baseline PAI levels and post-discharge reinfarction was observed.
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PMID:Correlation between baseline plasminogen activator inhibitor levels and clinical outcome during therapy with tissue plasminogen activator for acute myocardial infarction. 190 53

One hundred patients admitted to a centre of interventional cardiology with acute myocardial infarction of less than 6 hours, underwent coronary angioplasty of first intention because of contra-indications to thrombolytic therapy (n = 20) or after thrombolytic therapy with streptokinase (n = 54), acylenzymes (n = 12) or tissue type plasminogen activator (n = 14). The indication of angioplasty were those of the TIMI (Thrombolysis in Myocardial Infarction) classification (occluded artery, TIMI grade 0) (n = 60) (suboccluded artery, TIMI grade 1) (n = 40). The criterion of success of angioplasty was an increase greater than 1 of TIMI grade. Reperfusion of the coronary artery was obtained by angioplasty in 95% of failures of thrombolysis and in 90% of patients with contra-indications to thrombolytic therapy. The early reocclusion rate at D1 was 2%. Repeat angioplasty at D1 was successful in both these cases and the arteries were still patent at D21. The reocclusion rate at the third week in 75 patients who underwent control coronary angiography was 5.3%. In patients with arterial occlusion, immediate angioplasty attained two objectives in the same procedure: a high rate of emergency myocardial reperfusion and a low rate of reocclusion. The average left ventricular ejection fraction (all arteries) significantly improved (+9.2% in absolute values) when the artery remained patent (p less than 0.001), especially when the initial ejection fraction was low. In the patients who had occluded arteries at control angiography at 3 weeks, the ejection fraction decreased (-4% in absolute values) (NS). The following complications were observed: 4 coronary artery dissections and haematomas at the site of femoral puncture in patients who had received thrombolytic therapy (10 drained surgically). The hospital mortality was 3% and global mortality after an average follow-up period of 19.6 months was 5%. Coronary angioplasty in acute myocardial infarction carries a low risk and seems to be beneficial in patients with contra-indications to or failure of thrombolysis.
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PMID:[Acute myocardial infarction: immediate coronary angioplasty for failure or contra-indications of thrombolytic therapy. Apropos of a series of 100 cases]. 190 14

Recent technologic advances facilitate salvage of viable myocardium before the process of myocardial infarction is complete. The aim of thrombolytic agents is to restore antegrade flow of blood in occluded coronary arteries. The process of reperfusion may be dysrhythmogenic because of the heterogeneous return of electrical activity in myocardial cells. This study examined the incidence and type of dysrhythmia occurrence and the associated changes in mean arterial blood pressure (MAP) during infusion of tissue-type plasminogen activator (TPA). A retrospective chart review of 41 subjects showed that 80% of subjects experienced dysrhythmias during TPA therapy. The most common dysrhythmia was sinus bradycardia, followed by idioventricular/accelerated idioventricular rhythm, ventricular premature beats, and ventricular tachycardia/fibrillation. There was a significant difference between MAP changes when there were no dysrhythmias and MAP changes when dysrhythmias occurred (p less than 0.05). The largest change in MAP (-22.71 mm Hg) was observed when dysrhythmias occurred in those subjects with blockage of the left anterior descending artery, although there was no statistically significant difference in changes in MAP among the groups of different sites of blockage (p greater than 0.05).
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PMID:Dysrhythmias and blood pressure changes associated with thrombolysis. 190 43

Twenty patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator (rt-PA) had endogenous factor XII-dependent fibrinolytic activity levels measured throughout the hospital period and those levels were prospectively correlated with the incidence of recurrent myocardial infarction until 8 weeks after hospital discharge. Within the follow-up period, recurrent myocardial infarction was observed in 8 patients, whereas the remaining 12 patients showed no clinical evidence of recurrence. The patients in the reinfarction group were characterized by a more pronounced depletion of and sustained lower levels of factor XII-dependent fibrinolytic activity than were the patients with no reinfarction (p less than 0.05). The decrease in fibrinolytic activity during rt-PA therapy was significantly associated with a depletion of functional alpha 2-antiplasmin, the primary plasmin inhibitor. These results indicate that, paradoxically, coronary thrombolysis with rt-PA involves depletion of endogenous factor XII-dependent fibrinolytic activity levels, which constitutes a risk for early myocardial reinfarction.
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PMID:Depression of factor XII-dependent fibrinolytic activity characterizes patients with early myocardial reinfarction after recombinant tissue-type plasminogen activator therapy. 190 4

Tissue-type plasminogen activator (tPA) is a serine protease which cleaves plasminogen to its active form, plasmin. tPA plays a physiologic role in hemostasis, wound healing, and embryogenesis. Therapeutically, recombinant human tPA is used as a thrombolytic in myocardial infarction. Although production of therapeutic quantities of tPA in Chinese hamster ovary (CHO) cells transfected with the human gene for tPA is practical, production costs remain high. One important factor which determines the ultimate cost of tPA (or any other recombinant protein expressed in mammalian cells) is its production level on a per cell basis. We have used postembedding immunocytochemical staining with colloidal gold to study the subcellular localization of tPA in CHO cells expressing recombinant tPA (rCHO) in an effort to understand the factor(s) which might limit secretion. Staining for tPA was evaluated visually and by morphometric analysis and was specific and reproducible. Serially passaged rCHO showed no significant change in staining density over 31 serial passages. Staining density was greatest over dilated cisternae of the rough endoplasmic reticulum and nuclear envelope. Golgi stacks and large acid phosphatase-positive vacuoles (probably lysosomes) were also heavily stained. Staining of lysosomal vacuoles suggested that rCHO might be degrading nascent tPA. Incubation of rCHO with 125I-tPA showed that the cells were not internalizing tPA from the media. These results suggest that rCHO fail to secrete a portion of the tPA they synthesize and that it is degraded in lysosomes. This observation may have important implications on the choice of expression systems for efficient production of large quantities of recombinant proteins.
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PMID:Quantitative immunocytochemical staining for recombinant tissue-type plasminogen activator in transfected Chinese hamster ovary cells. 190 92

The (Thrombolysis in Myocardial Infarction) TIMI-I trial led to the hypothesis that the greater reperfusion rate seen with recombinant tissue-type plasminogen activator (rt-PA) versus streptokinase would result in greater reductions in infarct size and mortality in patients with acute myocardial infarction. Despite extensive investigation, no trial comparing rt-PA with streptokinase (European Cooperative Study Group, Plasminogen Activator Italian Multicenter Study [PAIMS], Gruppo Italiano per lo Studio della Sopravvivenze nell'Infarto Miocardico [GISSI-2], International Study on Infarct Survival [ISIS-3], even TIMI-I itself) nor rt-PA and anisoylated plasminogen-streptokinase activator complex (APSAC or anistreplase) (Bassand, TEAM-3, ISIS-3), have confirmed this hypothesis. In a reversal of traditional scientific method, the studies, rather than the unconfirmed hypothesis, have been rejected. A lack of independent review of this subject may have contributed to this outcome. It is proposed that standards of review and editorial comment mandating true critical distance and independence be followed, permitting greater independence of scientific inquiry, review and debate.
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PMID:Thrombolysis: the need for a critical review. 193 63

The incidence of myocardial infarction and sudden cardiac death is highest in the morning. Inhibition of fibrinolytic activity in blood also peaks in the morning and this inhibition may favor the development of arterial thrombosis. It has been reported that patients treated with beta blockers do not show the typical circadian pattern of onset of myocardial infarction and sudden cardiac death. This study was undertaken to investigate whether beta blockade alters the circadian rhythm of 2 major fibrinolytic factors, tissue-plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). Repeated blood samples were taken over a 24-hour period in 13 healthy volunteers: 7 taking 160 mg/day of long-acting propranolol orally for 14 days, and the other 6 taking no medications. Blood samples were analyzed for the plasma levels of t-PA activity, t-PA antigen, PAI activity and PAI-1 antigen. A significant circadian variation of all 4 parameters was present in both groups. No significant differences in peak and nadir values, 24-hour mean, amplitude of fluctuation, and time of peak and nadir were found between the treated and untreated subjects. The data therefore suggest that propranolol treatment does not affect the plasma concentrations at rest or the endogenous circadian rhythm of t-PA and PAI-1 in healthy volunteers. The reported alteration in the circadian pattern of onset of myocardial infarction and sudden cardiac death by beta blockers does not appear to be mediated by effects on the fibrinolytic system.
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PMID:Effect of propranolol (long-acting) on the circadian fluctuation of tissue-plasminogen activator and plasminogen activator inhibitor-1. 195 Nov 15

This study sought to determine whether clinical variables can be used to identify patients at high risk of recurrent spontaneous myocardial ischemia or hemodynamic compromise during the 1st 4 days after intravenous thrombolysis for acute myocardial infarction. Of 288 patients randomly assigned to a conservative postthrombolysis strategy, 54 (19%) required urgent cardiac catheterization within 24 h; 75 (26%) underwent urgent cardiac catheterization within 4 days of admission. Of the clinical variables examined by multiple logistic regression analysis, only patient age and anterior wall myocardial infarction correlated with the need for urgent cardiac catheterization (p = 0.0016 and p = 0.017, respectively). Compared with recombinant tissue-type plasminogen activator or urokinase monotherapy, combination therapy with these agents was associated with a lower need for acute intervention during the 1st 24 h after admission, but the difference did not reach statistical significance (14% for combination therapy vs. 21% for each agent alone, p = 0.30). Of the 75 patients undergoing urgent coronary angiography, only 39% had an occluded infarct-related artery. Emergency coronary angioplasty was performed in 49% of the patients and coronary artery bypass graft surgery was performed urgently in 3%. Despite these interventions, the need for urgent cardiac catheterization was associated with an in-hospital mortality rate of 7% (vs. 3% in the group not requiring urgent angiography, p = 0.36); mean left ventricular ejection fraction was 50.5 +/- 11% (vs. 54.3 +/- 10.8%, p = 0.12) and regional infarct zone wall motion was -2.68 +/- 1.07 SD/chord (vs. -2.46 +/- 1.19 SD/chord; p = 0.44).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Determinants of the need for early acute intervention in patients treated conservatively after thrombolytic therapy for acute myocardial infarction. TAMI-5 Study Group. 196 Mar 2

The safety and efficacy of a new regimen of intravenous recombinant tissue-type plasminogen activator (rt-PA) potentially suitable for either pre- or in-hospital administration were assessed in 60 patients with acute myocardial infarction in an open label coronary angiographic study. The regimen consisted of a 20-mg bolus dose followed 30 min later by a delayed infusion of 80 mg over 2 h. This regimen was designed to facilitate prehospital administration of rt-PA. Infarct-related artery patency (Thrombolysis in Myocardial Infarction [TIMI] grade 2 or 3 flow) was observed in 40 of 53 patients at 60 min (75.5%, 95% confidence intervals [CI] 61% to 84%) and in 55 of 60 patients at 90 min (91.7%, 95% CI 80% to 95%) after the rt-PA bolus. By 90 min the majority of patients (55%) exhibited TIMI grade 3 flow; infarct artery patency at 120 min was 84.9%. During hospitalization definite recurrent ischemia occurred in nine patients (15%); nonfatal recurrent infarction was noted in one (1.7%). Four patients (6.7%) experienced major bleeding, including one with intracranial bleeding. There were seven deaths (11.7%). Mortality was significantly influenced by the occurrence of cardiogenic shock, which was present in five patients at the time of enrollment. Blood fibrinogen levels were obtained before and during rt-PA infusion. At baseline and 30 and 150 min after the bolus dose, the mean fibrinogen level (+/- SD) was 284.83 +/- 77.39, 237.96 +/- 76.92 and 192.04 +/- 57.82 mg/dl, respectively. Compared with the baseline value, there was a significant (p less than 0.05) decrease in fibrinogen at both 30 and 150 min.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Safety and efficacy of a new regimen of intravenous recombinant tissue-type plasminogen activator potentially suitable for either prehospital or in-hospital administration. 196 Mar 29


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