Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty-three (75 per cent) of forty-four unselected children who had Legg-Perthes disease were found to have coagulation abnormalities. Twenty-three children had thrombophilia (a deficiency in antithrombotic factor C or S, with an increased tendency toward thrombosis); nineteen of the twenty-three children had protein-C deficiency and four had protein-S deficiency. Seven children had a high level (0.25 gram per liter or more) of lipoprotein(a), a thrombogenic, atherogenic lipoprotein associated with osteonecrosis in adults. Three children had hypofibrinolysis (a reduced ability to lyse clots). The mean age of the children when the Legg-Perthes disease was first diagnosed was 5.8 +/- 2.7 years, and the mean age at the time of the present study was 10.1 +/- 4.4 years. At least one of the first-degree relatives of eleven of the nineteen probands who had a low protein-C level had a low protein-C level as well; all of these low levels represented previously undiagnosed familial protein-C deficiency. The eleven probands who had familial protein-C deficiency were more likely to have early onset of Legg-Perthes disease (at or before the age of five years) than the eleven children who had normal levels of protein C, protein S, and lipoprotein(a) as well as normal fibrinolytic activity (chi-square = 6.6; p = 0.01). At least one first-degree relative of one of the four probands who had a low protein-S level had a low protein-S level and previously undiagnosed familial protein-S deficiency. At least one first-degree relative of six of the seven probands who had a high level of lipoprotein(a) had a familial high level of lipoprotein(a). Six of the seven children who had a high level of lipoprotein(a) also had a low level of stimulated tissue-plasminogen activator activity, the major initiator of fibrinolysis. At least one first-degree relative of one of the three probands who had normal levels of protein C, protein S, and lipoprotein(a) but low stimulated tissue-plasminogen activator activity also had low stimulated tissue-plasminogen activator activity (familial hypofibrinolysis). Legg-Perthes disease, thrombophlebitis, premature myocardial infarction, and stroke, which are ramifications of the familial thrombophilic-hypofibrinolytic disorders, were common in the first and second-degree relatives of the thirty-three children with Legg-Perthes disease who also had thrombophilic-hypofibrinolytic disorders.
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PMID:Association of antithrombotic factor deficiencies and hypofibrinolysis with Legg-Perthes disease. 956 92

Thrombolytic therapy provides clinical benefit in patients with vascular occlusions, depending upon the organ or limb that is threatened. The impact of therapeutic intervention varies from the quiet alteration of the course of deep vein thrombosis, for which non-life threatening post-phlebitic syndrome can be largely avoided, to the sometimes striking reversal of pulmonary hypertension and possible life-saving benefit in massive pulmonary embolism, the immediate alteration of clinical course in acute peripheral arterial occlusion by reducing the need for surgical intervention, cardiopulmonary complication and one year mortality, and finally to the dramatic and life-saving potential when applied in patients with acute myocardial infarction. Since the risk of serious hemorrhage, especially intracranial hemorrhage, is a constant, regardless of the underlying thrombotic problem, thrombolytic therapy will necessarily be applied variably according to the different potential therapeutic benefits. The balance of potential benefit versus the risk of intracranial hemorrhage in the situation of cerebrovascular thrombosis and stroke remains to be clarified by ongoing studies. As to the evidence for superiority of any single thrombolytic agent or regimen, direct comparative studies are still needed for patients with venous thrombosis and arterial occlusion. Available direct comparisons of two or three agents (streptokinase, urokinase, alteplase and anistreplase) in studies of pulmonary embolism and myocardial infarction show a consistent pattern that documents positive clinical benefit for all of the agents, with striking similarity in quantitative aspects despite marked differences in biochemical properties of the agents.
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PMID:Thrombolytic therapy: overview of results in major vascular occlusions. 857 40

Intravenous heparin is routinely given after thrombolytic therapy for patients with acute myocardial infarction in the United States and in some, but by no means all, other countries. Several trials have documented improved infarct-artery patency in patients treated with heparin; however, none was large enough individually to assess the effect of heparin on clinical outcomes. We performed a systematic overview of the 6 randomized controlled trials (1,735 patients) to summarize the available data concerning the risks and benefits of intravenous heparin versus no heparin after thrombolytic therapy. Mortality before hospital discharge was 5.1% for patients allocated to intravenous heparin compared with 5.6% for controls (relative risk reduction of 9%, odds ratio 0.91, 95% confidence interval 0.59 to 1.39). Similar rates of recurrent ischemia and reinfarction were observed among those allocated to heparin therapy or control. The rates of total stroke, intracranial hemorrhage, and severe bleeding were similar in patients allocated to heparin; however, the risk of any severity of bleeding was significantly higher (22.7% vs 16.2%; odds ratio 1.55, 95% confidence interval 1.21 to 1.98). There was no significant difference in the observed effects of heparin between patients receiving tissue-type plasminogen activator and those receiving streptokinase or anisoylated plasminogen streptokinase activator complex, or between patients who did and did not receive aspirin. The findings of this overview demonstrate that insufficient clinical outcome data are available to support or to refute the routine use of intravenous heparin therapy after thrombolysis. It is not known if these findings are due to lack of statistical power, inappropriate levels of anticoagulation, or lack of benefit of intravenous heparin. Large randomized studies of heparin (and of new antithrombotic regimens) are needed to establish the role of such therapy.
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PMID:Overview of randomized trials of intravenous heparin in patients with acute myocardial infarction treated with thrombolytic therapy. 861 Jun 1

We evaluated the genotypes of the angiotensin-converting enzyme (ACE) gene in 101 subjects with and 109 subjects without a history of ischemic stroke. All were attending a metabolic ward. The two groups were compared for major risk factors for ischemic events. Genotypes were determined by polymerase chain reaction with oligonucleotide primers flanking the polymorphic region in intron 16 of the ACE gene. Deletion polymorphism of the ACE gene (DD genotype) was shown to be more common in subjects with a history of stroke than in those without (relative risk, 1.76; confidence intervals, 1.02 to 3.05). A positive family history for ischemic complications of atherosclerosis was also more common in subjects with documented events (relative risk, 1.99; confidence intervals, 1.10 to 3.59). DD genotype and a positive family history were strong independent discriminators of cerebral ischemia. Plasma levels of tissue-type plasminogen activator (TPA) and plasminogen activator inhibitor-1 help identify subjects with a history of cerebral ischemic episodes. When such fibrinolytic variables were included in the analysis, the DD genotype still strongly and independently discriminated subjects with a stroke history and significantly interacted with TPA levels > 10 ng/mL in such identification. We conclude that in subjects attending a metabolic ward, homozygosity for a deletion polymorphism of the ACE gene consistently discriminates subjects with a stroke history. Interaction with TPA improves such identification.
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PMID:Deletion polymorphism in the angiotensin-converting enzyme gene in patients with a history of ischemic stroke. 862 Mar 47

The fibrinolytic system is thought to be impaired in older hypertensive adults, thus contributing to the elevated risk of atherothrombosis, stroke, and acute myocardial infarction in this population. However, studies that have examined the fibrinolytic system in hypertensive individuals have failed to control for the confounding effects of other metabolic risk factors, making it difficult for one to determine the independent effect of hypertension on the fibrinolytic system. The purpose of the present study was to test the hypothesis that the fibrinolytic system is not impaired in older sedentary hypertensive men when the confounding effects of cardiovascular disease, diabetes, and dyslipidemia are controlled. Plasma concentrations of tissue-type plasminogen activator antigen and activity as well as plasminogen activator inhibitor-1 antigen and activity were measured under resting conditions in 12 hypertensive (69.4 +/- 1.4 years) and 11 normotensive 65.2 +/- 1.3 years) older men. The hypertensive and normotensive subjects had similar anthropometric and metabolic characteristics. There were no significant differences between the hypertensive and normotensive men in tissue-type plasminogen antigen (7.3 +/- 0.5 versus 6.1 +/- 0.6 ng/mL) and activity (1.8 +/- 0.3 versus 1.7 +/- 0.2 IU/mL) or plasminogen activator inhibitor-1 antigen (14.1 +/- 2.3 versus 10.8 +/- 2.2 ng/mL) and activity (17.4 +/- 1.2 versus 17.5 +/- 1.8 arbitrary units [AU]/mL) levels. In addition, the molar concentration ratio of active tissue type plasminogen activator to active plasminogen activator inhibitor-1 did not differ between the hypertensive (1:9.7 +/- 2.3) mmol/L) and normotensive (1:10.5 +/- 2.2 mmol/L) subjects, indicative of no impairment in fibrinolytic potential in either group. These results support the hypothesis that hypertension does not directly result in impaired fibrinolytic function in older adults. Furthermore, our findings suggest that abnormalities in fibrinolytic function in older hypertensive men are likely due to the primary effects of other metabolic disorders that usually accompany hypertension, such as hyperinsulinemia and dyslipidemia.
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PMID:The fibrinolytic system is not impaired in older men with hypertension. 862 Nov 96

This study was designed to evaluate the effects of tissue-type plasminogen activator (tPA) and 21- amino steroid (U74006F) in experimental embolic stroke in rabbits. The size of infarction from embolism was compared to controls with tPA alone, 21-amino steroid alone, and in combination. The middle cerebral artery of the rabbit was embolized by injecting an arterial ('white') thrombus in the right internal carotid artery. The rabbit treatment was 2 mg kg-1 of tissue-type plasminogen activator and/or 3 mg kg-1 of 21 amino steroid started at 2 h post-embolization. The animals were terminated 4 h post-treatment and brains were examined for evidence of ischemia and/or hemorrhage. Administration of tissue-type plasminogen activator and/or 21-amino steroid in the raw data show that there is a tendency for all treatments to reduce the ischemic volume when compared to the control group, also it is evident the standard deviation of these estimates is rather large when compared to the differences between treatments. The results of the analysis of variance shows that the differences expressed are not statistically significant. (No statistical differences were found between the treatment groups and the control group.) The results show that administration of tissue-type plasminogen activator and/or 21 amino steroid at 2 h post-embolization alone or in simultaneous administration does not significantly reduce the volume of infarction. Further studies need to be addressed in regards to the region of viable brain in the peri-infarct area, in reducing the time to treatment.
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PMID:Influence of a 'brain protector' drug 21-amino steroid on the effects of experimental embolic stroke treated by thrombolysis. 862 95

Thrombolytic therapy is used in many cardiovascular diseases other than myocardial infarction and pulmonary embolism. In unstable angina, the results of trials have rather been disappointing. In prosthetic valve thrombosis, the role of thrombolytic therapy is increasing. In peripheral arterial thrombosis, intravenous thrombolysis was practically abandonned and local administration has been tried but no systematic attitude can be deduced. In cerebral arterial thrombosis intravenous alteplase thrombolytic treatment is effective and relatively safe in a well defined subgroup of stroke patients with moderate to severe neurologic deficit and without extended infarct signs on the initial CT scan.
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PMID:[Thrombolytic therapy in arterial disorders other than myocardial infarction]. 867 42

The use of fibrinolytic agents in acute ischemic stroke has received increasing attention due to the completion of several prospective studies examining the efficacy and safety of these drugs in this clinical setting. Experience with plasminogen activators indicates that recanalization of carotid and vertebrobasilar territory occlusion is feasible within 4-6 hours of symptom onset. The optimal plasminogen activator, its dose-rate and delivery system, however, is not known. The phase III trial of the European Cooperative Acute Stroke Study (ECASS) suggests potential modest benefit in outcome, although recombinant tissue plasminogen activator (rt-PA) had an increased risk of hemorrhage attributable to those patients with early CT-scan signs of ischemia. Complete cervical internal carotid artery occlusions by in situ thrombosis appear more resistant to thrombolysis than occlusions of the stem and major branches of the middle cerebral artery. The issue of hemorrhagic transformation is unsettled. It seams to be increased by delayed intervention on the one hand, but it is not different from that observed in placebo patients in phase I/II series.
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PMID:Thrombolysis in acute stroke. 871 49

The successful application of thrombolytic therapy to acute myocardial infarction has prompted a reinvestigation of thrombolytic therapy for acute stroke. However, an examination of safety and efficacy of thrombolytic therapy in acute thromboembolic stroke has precluded the entry of patients taking either antiplatelet or anticoagulant therapy. It was therefore of interest, in an established rabbit model of thromboembolic stroke, to examine the use of tissue plasminogen activator therapy in combination with ticlopidine treatment. Following ticlopidine administration (10 mg kg-1, i.v., daily for 5 days), rabbits (n = 7) were embolized by injecting a tin-laden clot into the internal carotid artery with clot placement confirmed by x-ray. Three hours later, t-PA was initiated as a square-wave pulse (6.3 mg kg-1 total dose, given as a 20% bolus, with the remainder administered over 2 h as a continuous infusion). The protocol was continued for a total of 7 h following embolization. Complete clot lysis was demonstrated in 6 of 7 animals. Brain infarct size (triphenyltetrazolium chloride staining) was 36.0 +/- 12.9% hemisphere (mean +/- SEM). Both clot lysis rate and infarct size were very similar to that previously seen following administration of t-PA alone (58% and 31.6 +/- 6.4% hemisphere, respectively) but in marked contrast to previous results seen with intravenous aspirin (no clot lysis). These results suggest that antiplatelet agents used clinically for stroke prophylaxis (aspirin or ticlopidine) may influence the success rate of thrombolysis following initiation of thrombolytic therapy for acute thromboembolic stroke.
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PMID:Combination tissue plasminogen activator and ticlopidine therapy in a rabbit model of acute thromboembolic stroke. 871 36

Therapy for stroke is undergoing major changes. Many of the changes parallel the advances made in the therapy for myocardial infarction. Acute intervention with cytoprotective and thrombolytic agents is undergoing active investigation. Cytoprotective therapy includes drugs that act to prevent cell death during ischemia and reperfusion. These agents include calpain inhibitors, voltage-sensitive calcium- and sodium-channel antagonists, receptor-mediated calcium-channel antagonists [including N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) antagonists], glutamate-synthesis inhibitors, glutamate-release antagonists, gamma-aminobenzoic acid (GABA) antagonists, 5-HT (serotonin) receptor agonists, gangliosides, antioxidants, growth factors, antiapoptotic agents, and antiadhesion molecules. Thrombolysis is effective in myocardial infarction. Thrombolysis is undergoing evaluation in stroke with streptokinase, anisoylated plasminogen streptokinase activator complex (APSAC), tissue plasminogen activator (t-PA; including recombinant t-PA), urokinase, and single-chain urokinase (scu-PA). Both systemic and selective administration are being evaluated. Preventive therapy with both antiplatelet and anticoagulant drugs sheds new light on how best to stratify patients in terms of a risk-benefit ratio. Continuing public education will be essential as stroke therapy advances.
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PMID:Medical therapy for ischemic stroke. 877 66


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