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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antistreptokinase antibodies present in patients as a result of previous streptococcal infections might theoretically influence the thrombolytic response to streptokinase or anistreplase. The potential influence of antibody, measured as antigen binding to immunoglobulin G, was investigated in a randomized, double-blind, multicenter patency comparison of intravenous streptokinase (1.5 million units/60 minutes) and intravenous anistreplase (30 units/2 to 5 minutes) in patients with acute myocardial infarction. Antibody results were evaluated in 333 patients (from a total study population of 370 patients) less than 76 years of age with ECG evidence of ST segment elevation who could be treated within 4 hours of the onset of symptoms. Variations in pretreatment circulating levels of antibody did not influence angiographically defined early coronary patency rates (Thrombolysis in Myocardial Infarction grade 2 or 3 perfusion, measured at a mean of 140 minutes after therapy was begun) for either streptokinase or anistreplase. Similarly the lytic response represented by systemic plasminogen activation and measured as changes in plasma plasminogen and fibrinogen levels after dosing (at mean times of 90 minutes and 24 hours) was not correlated with baseline antibody levels. Furthermore, pretreatment antibody was not a risk factor for poor outcome in response to streptokinase or anistreplase (reocclusion within 24 hours, in-hospital death, or stroke) and did not correlate with hypotension or allergic-type reactions recorded as adverse events. In conclusion, within the population limits defined by the inclusion and exclusion criteria of the study (patients were excluded if they had received streptokinase or anistreplase within the previous 6 months), pretreatment antistreptokinase immunoglobulin G is not a significant determinant of the efficacy response to streptokinase or anistreplase.
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PMID:Lack of influence of pretreatment antistreptokinase antibody on efficacy in a multicenter patency comparison of intravenous streptokinase and anistreplase in acute myocardial infarction. 163 74

A study was made of blood coagulation, physiological anticoagulants and fibrinolysis in 120 elderly patients with cerebrovascular diseases, including 50 subjects in the acute period of ischemic brain stroke. To estimate activation of the fibrinolytic system, the levels of plasminogen and free plasmin were measured. Phasic changes in the system of blood coagulation were detected, variants of antithrombin III depression were delineated, and a relationship was established between the activity of enzymes of the fibrinolytic system and the site of an ischemic focus in the brain. Five coagulopathic syndromes of the acute period of brain stroke were distinguished, the principles of their differentiated treatment were based.
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PMID:[Diagnosis and treatment of coagulopathic syndromes in ischemic stroke]. 166 74

To study the thrombolytic effect of tissue plasminogen activator (t-PA) on cerebral emboli, we characterized cerebral embolization in stroke-prone spontaneously hypertensive rats (SHRSPs) and Wistar Kyoto rats (WKYs). [125I]Fibrin clot particles (20-100 microns diameter) were injected twice at an interval of 90 min into the left internal carotid artery of WKYs and SHRSPs. After each injection, spontaneous embolus dissolution was monitored with a gamma-ray detector placed on the head of the embolic rats. Embolus dissolution was spontaneously generated in 15 min after the injection of fibrin clots. In WKYs, 21% and 42% of the clots were dissolved 30 and 90 min after the second embolization, respectively. On the other hand, the spontaneous embolus dissolution in SHRSPs was significantly lower than that of WKYs, indicating that the endogenous fibrinolytic ability of SHRSPs is less potent than that of normotensive rats. The intravenous administration of t-PA at doses of 75, 250 and 750 micrograms/kg caused a dose-dependent embolus dissolution in SHRSPs. Furthermore, systematically applied t-PA produced embolus dissolution without causing systemic plasminogen activation, fibrinogen breakdown or bleeding. In conclusion, the intravenous administration of t-PA produces selective embolus dissolution without systemic fibrino(geno)lysis in a cerebral embolic SHRSP.
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PMID:Fibrinolytic effect of tissue plasminogen activator on cerebral embolism in stroke-prone spontaneously hypertensive rats. 181 26

In the Thrombolysis in Myocardial Infarction, Phase II pilot and clinical trial, 908 patients [326 (35.9%) in the pilot study and 582 (64.0%) in the randomized study] were treated with 150 mg recombinant tissue-type plasminogen (rt-PA) activator in combination with heparin and aspirin, and 3,016 patients [64 (2.1%) in the pilot study and 2,952 (97.9%) in the randomized study] were treated with 100 mg rt-PA in combination with heparin and aspirin. Adverse neurological events occurred in 23 patients treated with 150 mg rt-PA (2.5%) [nine cerebral infarctions (1.0%), 12 intracerebral hemorrhages (1.3%), and two subdural hematomas (0.2%)] and in 33 patients treated with 100 mg rt-PA (1.1%) [20 cerebral infarctions (0.7%), 11 intracerebral hemorrhages (0.4%), and two subdural hematomas (0.1%)]. The difference in adverse neurological events observed comparing the two rt-PA regimens was primarily due to a higher frequency of intracerebral bleeding among patients treated with 150 mg rt-PA (1.3% versus 0.4%, p less than 0.01). Patients with recent (within 6 months) histories of stroke were not eligible for the study, and patients with any history of cerebrovascular disease were declared ineligible early in the study. The small number of patients (89, or 2.3%) with any history of neurological disease, intermittent cerebral ischemic attacks, or stroke who were enrolled before the stricter eligibility criteria were imposed or on the basis of incomplete baseline information experienced an increased frequency of intracerebral hemorrhage compared with patients without such histories (3.4% versus 0.5%). Mortality at 6 weeks after presentation among 23 patients who had intracerebral hemorrhage was 47.8%. Intracerebral hemorrhage is a severe but infrequent complication of rt-PA therapy for acute myocardial infarction. The combined frequency of intracerebral hemorrhage, subdural hematoma, and cerebral infarction after treatment with 100 mg rt-PA is comparable to that observed in other trials with thrombolytic agents in acute myocardial infarction.
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PMID:Intracerebral hemorrhage, cerebral infarction, and subdural hematoma after acute myocardial infarction and thrombolytic therapy in the Thrombolysis in Myocardial Infarction Study. Thrombolysis in Myocardial Infarction, Phase II, pilot and clinical trial. 189 64

Recombinant tissue plasminogen activator may be effective in preventing cerebral vasospasm after subarachnoid hemorrhage by resolving subarachnoid clots. We previously demonstrated that blood placed on the adventitial surface of cerebral arteries enhances intimal platelet accumulation, positively correlating with endothelial damage and other pathologic changes in vessel walls. In this study, we investigated the ability of a single bolus injection of tissue plasminogen activator to prevent platelet accumulation in cerebral vessels after subarachnoid hemorrhage. Subarachnoid hemorrhage was produced in cats by the transorbital intracisternal injection of 2.5 ml autologous arterial blood around the proximal part of the right middle cerebral artery. In 10 animals, 25 micrograms tissue plasminogen activator was injected at intervals of 10 (five cats) and 60 minutes (five cats) after subarachnoid hemorrhage. Intracisternal physiological saline (0.5 ml) was injected in six cats 10 minutes after subarachnoid hemorrhage. Platelets labeled with indium-111 were injected intravenously just before subarachnoid hemorrhage, and their radioactivity was measured in cerebral arteries at death. The results indicated that, after subarachnoid hemorrhage, early injection of tissue plasminogen activator inhibited intimal platelet accumulation, but later injection did not, although the extent of subarachnoid clot was reduced at both plasminogen injection times.
Stroke 1991 Jun
PMID:Effect of tissue plasminogen activator on intimal platelet accumulation in cerebral arteries after subarachnoid hemorrhage in cats. 190 29

Although thrombolytic agents were discovered nearly 60 years ago, it is only within the past decade that the clinical use of these agents has revolutionized the treatment of acute myocardial infarction. There are four currently available agents approved for use in treatment of myocardial infarction: streptokinase, urokinase, tissue plasminogen activator, and anistreplase. Although each of these agents works in a unique fashion, the common end point of therapy is the dissolution of a fibrin clot by the conversion of plasminogen to plasmin. A number of clinically measurable end points have been used to determine the effectiveness of these agents in the treatment of acute myocardial infarction, including mortality, reperfusion, patency, left ventricular function, left ventricular volumes, and quantitative creatine kinase isoenzyme analysis. Secondary end points have included bleeding and stroke, as well as recurrent ischemic events. Numerous clinical studies have demonstrated the effectiveness of all of these agents in achieving the desired end points and comparative studies, including several large-scale trials, have failed to differentiate among these agents with regard to efficacy. Newer dosing regimens for currently available thrombolytic agents, as well as new thrombolytic agents, are currently under active investigation and will be the subject of intense research over the next few years. Despite the lack of consensus as to which agent is superior, it is clear that thrombolytic therapy for acute myocardial infarction is the treatment of choice.
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PMID:Thrombolytic therapy: then and now. 191 23

Hemostatic disorders in coronary heart disease and cerebrovascular disease patients were examined by studying two groups of prothrombotic and prethrombotic markers. Sixty subjects (28 male, 32 female aged 64 +/- 6 years) were included in the study of which 30 suffered from coronary heart disease and 30 from cerebral vascular disease; the first group was subdivided into those subjects with quiescent preinfarction angina (21 cases) and those with acute myocardial infarction (9 cases), whereas the second group was subdivided into subjects with cerebral stroke (20 cases) and those with TIA (10 cases). Each subject underwent an assay to assess fasting blood levels of fibrinogen, factor VII, antithrombin III (using a chromogenic method), plasminogen tissue activator, beta-thromboglobulin and dimer-D (ELISA method) 24 hours after being admitted to hospital. From an analysis of results it was observed that of the four prothrombotic markers used, fibrinogen and factor VII showed a generic increase in comparison to coronary heart disease and cerebrovascular disease patients; this was paralleled by significant reduction of antithrombin III; differences were even more marked and significant in acute thrombo-occlusive (infarction, stroke) compared to functional forms (angina, TIA). In line with other studies, the Authors favour an irritative type endothelial response leading to a marked and surprising increase of tPA. The two prothrombotic markers (BTG, D-D) also showed a thrombotic development in the two groups of patients examined with more significant findings in the occlusive forms (infarction, stroke) in comparison to transitory forms. On the basis of these and other published results the Authors confirm the usefulness of monitoring prothrombotic markers (fibrinogen, factor VII, AT III) in apparently normal subjects with or without risk factors or with slight initial signs of arteriosclerotic disease; these call for longitudinal or cross-sectional studies of an epidemiology type, in addition to isolated assay for a generic assessment of the patient's biological status, even if it is not yet possible to elaborate a protocol for the certain and specific diagnosis of a thrombophilic condition. The value of prethrombotic markers is apparent in the acute occlusive stage of the disease as a form of prognostic and therapeutic monitoring, and in preinfarction and above all silent transitory forms where, together with the use of other techniques (Holter), it provides interesting openings for confirming the diagnosis of an in vivo microthrombotic genesis and the consequent introduction of antithrombotic drug therapy.
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PMID:[The thrombophilic status and ischemic cardiopathy]. 195 44

We describe a patient with inherited plasminogen deficiency who developed extensive cerebral venous thrombosis. Several other conditions that might have contributed to a hypercoagulable state, including mild thrombocytosis, thyrotoxicosis, and a chronic inflammatory lung disorder, were present. We also discuss the evidence linking plasminogen deficiency with a thrombophilic state. The diagnosis of cerebral venous thrombosis in this case was readily established by nuclear magnetic resonance imaging, a technique that is ideally suited for the evaluation and follow-up of patients with this condition.
Stroke 1991 Mar
PMID:Cerebral venous thrombosis with plasminogen deficiency. 200 11

All thrombolytic agents convert plasminogen to plasmin, either directly, as in the case of urokinase, saruplase, and alteplase, or indirectly, as in the case of streptokinase. In the majority of recent clinical trials with streptokinase, a high-dose (0.7-1.5 million units), brief-duration (30-90 minutes) drug regimen has been used. After a mean interval of 4.2 hours from onset of chest pain to intravenous infusion of streptokinase, repeat angiography performed 60-90 minutes after the start of thrombolytic treatment gave a reperfusion rate of 43%; the corresponding figures for anistreplase, saruplase, and alteplase are 56%, 67%, and 69%. The patency rates obtained in similar studies with the same end point are 56% for streptokinase, 77% for anistreplase, 62% for urokinase, 71% for saruplase, and 75% for alteplase. The in-hospital mortality in randomized trials (six large studies in a total of 31,713 randomized patients) with intravenous high-dose streptokinase decreased from 12.0% in the control group to 9.47% in the streptokinase group. In a mortality study involving 1,258 patients randomized to intravenous anistreplase or placebo, the 30-day mortality was reduced by 47%, from 12.2% to 6.4%. In a large trial in which 5,011 patients were randomized to alteplase or placebo, the 30-day mortality was 7.2% compared with 9.8% in controls, a reduction of 27% by alteplase. In another trial, 721 patients were randomized to placebo or alteplase; all patients received acetylsalicylic acid and intravenous heparin. The 14-day mortality was only 2.8% in the alteplase group, 51% less than that in the control group. It is most important that the favorable impact on hospital survival be maintained at 1 year for any thrombolytic drug. Large-scale trials directly comparing mortality after alteplase, streptokinase, or anistreplase are being performed or are in the planning phase. The risk of bleeding exists with any thrombolytic agent; intracranial bleeding is the most serious risk. In a large trial in 5,011 patients with acute myocardial infarction, stroke occurred in 1.1% of alteplase-treated patients compared with 1.0% in placebo-treated controls. Haunting problems are residual stenosis of the coronary artery and reocclusion. Urgent angioplasty does not seem to be the right answer; more effective antithrombotic strategies have yet to be developed.
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PMID:Thrombolytic treatment in acute myocardial infarction. 211 32

Ten clinically healthy subjects (5 men and 5 women), 31 +/- 11 yrs of age, were studied at six timepoints (0800, 1200, 1600, 2000, 0000, 0400) distributed over a 1-week span. Circadian rhythms in platelet aggregation in response to adenosine diphosphate (ADP) and adrenalin (A), platelet adhesiveness measured as retention in a glass bead column, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen, Factor VIII activity and alpha-1-antitrypsin antigen showed circadian rhythms. The plasma concentrations of plasminogen, alpha-2-macroglobulin, and antithrombin III (AT III) antigen, Factor V and fibrinogen degradation products showed no circadian rhythm by ANOVA or cosinor analysis. The phase relations of the rhythms of different coagulation parameters are of interest in the physiology and pathobiology of the coagulation-fibrinolytic system. The extent of the circadian rhythm (range of change) described is not of a magnitude to lead to diagnostic problems in the clinical laboratory. The timing of these rhythms, however, may determine transient risk states for thromboembolic phenomena, including myocardial infarction and stroke. Several but not all coagulation parameters suggest a transient state of hypercoagulability during the morning hours. The recognition of these rhythmic, and thus in the time of the occurrence predictable temporary risk states for thromboembolic phenomena, may lead to timed treatment and/or effective prevention.
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PMID:Circadian variations in blood coagulation parameters, alpha-antitrypsin antigen and platelet aggregation and retention in clinically healthy subjects. 212 46


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