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

We retrospectively evaluated 66 patients younger than 40 years of age who presented with acute nonhemorrhagic cerebral infarction (n = 63) or transient ischemic attacks (n = 3) to determine the possible etiology and long-term outcome at a mean follow-up interval of 3 years after initial presentation. A probable cause for the stroke was identified in 24 patients (36%); this group included one woman with a history of recurrent spontaneous abortions and a positive test for the presence of the lupus anticoagulant. We performed detailed hemostatic investigations at follow-up in 38 (90%) of the remaining 42 patients in whom the cause of the stroke was unknown or uncertain; results of the basic hemostatic screening tests (including that for fibrinogen) were uniformly normal. All 38 patients demonstrated a normal fibrinolytic response as measured by tissue plasminogen activator release to a standard venous occlusion stress test; concentration of the inhibitor of tissue plasminogen activator was not increased. No abnormalities in the concentrations of the inhibitory proteins C or S or antithrombin III were identified, and none of the 38 patients had evidence of a lupus anticoagulant. Neurologic recovery was complete or the residual disability mild in 46 of 59 (78%) patients. Overall prognosis was excellent and independent of whether a precipitating factor for the stroke could be identified.
Stroke 1989 Apr
PMID:Etiology, prognosis, and hemostatic function after cerebral infarction in young adults. 249 81

We present the case of a 42-year-old female, who suffered an embolic occlusion of the right middle cerebral artery (MCA). Recanalization was achieved with tissue plasminogen activator (t-PA) within 7 h after onset of stroke. Post-t-PA infusion angiographic and CT examinations revealed fragmentation of the thrombus and a small putaminal haemorrhage associated with early reperfusion of the MCA. No clinical deterioration was observed and complete recovery occurred within 10 days.
 ...
PMID:Putaminal haemorrhage after recanalization of an embolic MCA occlusion treated with tissue plasminogen activator. 249 2

Early fibrinolytic therapy with full molecular tissue plasminogen activator (t-PA) has been observed to be both angiographically and clinically effective when employed in animal stroke models. Preliminary clinical trials with t-PA are in progress. It is possible to refine t-PA by developing fragments or analogues of the drug. Using recombinant DNA technology in the Escherichia coli system, a t-PA analogue consisting of the catalytic fragment of t-PA and a dimer of the B fragment of staphylococcal protein A (Fb-Fb-CF) has been produced. Because this analogue has a long serum half-life of 90 minutes, we employed Fb-Fb-CF in a rabbit cerebral embolic stroke model to assess its efficacy as a reperfusion agent. When given as a bolus to 10 animals 15 minutes after embolization, Fb-Fb-CF produced angiographic cerebral reperfusion in 48 +/- 21 minutes (+/- SD), while in 8 saline-treated controls, reperfusion was not observed at 180 minutes in any animal (p less than 0.01). In another experiment reperfusion was demonstrated at 66 +/- 32 minutes in 11 animals treated with Fb-Fb-CF 90 minutes after embolization as compared with 100 +/- 25 minutes in 12 saline-treated controls (p less than 0.01). A small macroscopic hemorrhage within an infarct was seen in 1 Fb-Fb-CF-treated animal in the 15-minute experiment and in none of the controls. In the 90-minute experiment, macroscopic hemorrhagic infarction was seen in 4 Fb-Fb-CF-treated animals and in 3 controls.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The effects of a new tissue plasminogen activator analogue, Fb-Fb-CF, on cerebral reperfusion in a rabbit embolic stroke model. 249 44

The use of local low dose thrombolysis is gradually increasing. Most experience is with streptokinase, although newer agents such as recombinant tissue plasminogen activator (rTPA) may offer more effective lysis with reduced complications. We have reviewed the experience documented in 19 prospective series published between 1974 and 1988 in an attempt to define the incidence of stroke, major haemorrhage and minor haemorrhage. The overall risk of stroke was 1.0 per cent of patients (14 cases). Major haemorrhage occurred in 5.1 per cent of patients (71 cases) and minor haemorrhage occurred in 14.8 per cent (92 out of 620 cases). There was little difference between the two thrombolytic agents, although the experience with lower doses of rTPA suggests it may offer a reduced risk of haemorrhagic complications. It is essential that all studies concerning thrombolysis should give their exclusion and inclusion criteria in full to allow an accurate appraisal of haemorrhagic complications, with the hope of improved patient selection and reduced morbidity in the future.
 ...
PMID:Local low dose intra-arterial thrombolytic therapy: the risk of stroke or major haemorrhage. 251 2

To test the utility and safety of percutaneous transluminal coronary angioplasty (PTCA) after recombinant tissue plasminogen activator (t-PA), we performed the procedure in all suitable candidates with acute myocardial infarction (MI) who had successful t-PA mediated coronary thrombolysis. Twenty consecutive patients with MI received t-PA after coronary angiographic conformation of total occlusion. Successful recanalization with t-PA was achieved in 13 patients, leaving a residual obstruction of 84 +/- 6% in the nine patients for whom PTCA was attempted at a mean of 21.6 h. Success was achieved in seven patients, leading to a residual lesion of 29 +/- 7%. In the two patients for whom PTCA was unsuccessful, total reocclusion occurred prior to the attempt despite therapy with heparin, aspirin, dipyridamole, and nifedipine. All PTCA procedures were uncomplicated. Serial two-dimensional echocardiography at 10 days, compared to admission, demonstrated infarct zone wall motion index improvement in the patients with successful PTCA (group A, 0.83 +/- 0.36 to 1.46 +/- 0.49) as compared to the 13 patients without thrombolysis or successful PTCA (group B, 0.61 +/- 0.26 to 0.66 +/- 0.39), (P less than 0.05). One patient of group A sustained a massive stroke at 2 weeks after hospital discharge. In the remaining six patients, follow-up exercise testing and/or coronary arteriography demonstrated a negative treadmill test and/or patent infarct vessel, respectively. After successful PTCA, no patient had clinical signs of reocclusion, reinfarction, postinfarction angina, or congestive heart failure. At 9.4 +/- 2 months, all six patients are asymptomatic and have returned to work. Thus, sequential PTCA after t-PA can be performed safely and successfully in patients with MI and this approach may be associated with improved regional function and a favorable post-MI course.
 ...
PMID:Applicability of percutaneous transluminal coronary angioplasty to patients with recombinant tissue plasminogen activator mediated thrombolysis. 293 Nov 76

Early experience with the use of tissue plasminogen activator (tPA) in acute myocardial infarction is reviewed, including comparisons with other thrombolytic agents, a summary of hemorrhagic complications associated with its use, and the rationale for adjunctive therapeutic strategies. The use of tPA has been associated with improvement in left ventricular function, a lower mortality, and a decrease in congestive heart failure signs and symptoms. A protocol for evaluation of patients with possible myocardial infarction for thrombolytic therapy is presented. Consideration must be given to other possible diagnoses, and the ECG must be evaluated carefully to ensure that appropriate criteria are met. Risk factors for hemorrhagic complications include recent trauma, surgery, gastrointestinal and genitourinary bleeding, stroke, and focal neurologic findings. Greater benefit of therapy is expected in patients with larger infarcts who have more marked ST segment changes or evidence of hemodynamic compromise, especially when they are treated early after the onset of symptoms (within the first several hours). Adjunctive measures that can be considered in the emergency department include prophylactic lidocaine, IV nitroglycerin, beta blockade, aspirin, volume replacement and monitoring for dysrhythmias, bleeding, and recurrent ischemia. A comprehensive understanding of these rapidly evolving concepts will assist the emergency physician in the evaluation and management of patients with acute myocardial infarction.
 ...
PMID:Experience with the use of tPA in the treatment of acute myocardial infarction. 297 70

Recent success with thrombolytic therapy for acute myocardial infarction has stimulated interest in its use for stroke. To determine the hemorrhagic potential of thrombolytic therapy in experimental cerebral infarction, we compared a group of tissue plasminogen activator-treated rabbits (n = 4) with 2 groups of streptokinase-treated rabbits (n = 6 in each), as well as with 3 groups of heparin-treated rabbits (n = 5 in each) and untreated controls (n = 12). Focal cerebral infarction was produced in rabbits by occlusion of the right common carotid and middle cerebral arteries coupled with 2 hours of halothane-induced hypotension. Treatment with heparin or thrombolytic agents began 24 hours after occlusion. One additional group was treated with streptokinase 1 hour after occlusion (n = 6) to determine the hemorrhagic potential of thrombolytic agents in evolving infarction. Rabbits were killed 29-33 hours after occlusion, and brain sections were examined using light microscopy. The results demonstrate that microscopic hemorrhage is frequently present in infarcted tissue irrespective of treatment. Gross cerebral hemorrhage did not occur in untreated rabbits or in rabbits treated with streptokinase 1 hour after occlusion. Only rabbits treated with streptokinase, tissue plasminogen activator, or excessive doses of heparin 24 hours after occlusion, at a time when cerebral infarction was well established, exhibited gross hemorrhage in the area of infarction. These data suggest that treatment of ischemic stroke with thrombolytic agents carries an increased risk of cerebral hemorrhage unless the agents are given early after the onset of symptoms.
Stroke
PMID:Hemorrhagic complications of thrombolytic therapy in experimental stroke. 312 Mar 60

We evaluated the efficacy of intravenously administered recombinant tissue plasminogen activator to lyse laser-induced arterial thrombi in the stroke-prone, spontaneously hypertensive rat model. The arterial thrombi were confirmed histologically, and assessed by color photographs and fluorescein angiography before and after intravenous tissue plasminogen activator or saline therapy. Experimental animals received tissue plasminogen activator (1 mg/kg of body weight) given intravenously over one hour, and control animals received similar volumes of normal saline. Tissue plasminogen activator was effective in lysing experimental retinal arterial thrombi.
 ...
PMID:Recombinant tissue plasminogen activator to lyse experimentally induced retinal arterial thrombi. 312 46

We describe a model of thromboembolic stroke in rabbits that utilizes the Seldinger technique and digital arteriography. The internal carotid arteries of 14 rabbits were catheterized selectively and embolized with autologous blood clots. After embolization, eight rabbits received IV tissue plasminogen activator (tPA); the remaining six were infused with saline and served as controls. After embolization, cerebral arteriograms were obtained at 30-min intervals for 180 min. Cerebral arteriograms obtained after tPA therapy revealed partial or complete thrombus dissolution in seven (88%) of the eight treated rabbits. In the control group, none of the arteriograms of the embolized internal carotid arteries showed thrombus dissolution. In the tPA-treated group, the median time for thrombus dissolution was 60 min. This stroke model is economical, reproducible, and less traumatic to the brain than most of the previously described animal models. It also provides a means to compare the safety and efficacy of various thrombolytic agents in small animals.
 ...
PMID:Selective embolization and clot dissolution with tPA in the internal carotid artery circulation of the rabbit. 314 Jun 34

Significant current interest has focused on the possible value of fibrin-selective thrombolytic agents in acute stroke. Acute thrombosis contributes to carotid and vertebrobasilar arterial occlusions in the majority of acute stroke patients. Hence, fibrin(ogen)olytic agents may produce arterial recanalization and clinical benefit in thrombotic stroke. There are, however, unique features of cerebral tissue that suggest caution with the use of fibrin-selective agents in cerebral ischemia. The specific vascular anatomy and collateral flow suggest that salvage of the "ischemic penumbra" following vascular recanalization in focal ischemia is more likely to be successful than attempts in global ischemia. Recanalization may be associated with reperfusion injury and, more importantly, the risk of hemorrhagic transformation. There is little concrete information regarding the relative contribution of either event to post-thrombolysis cerebral injury. Early studies with exogenous fibrinolytic agents (urokinase, streptokinase) in completed stroke were regarded as inconclusive, demonstrating only an increased risk of intracerebral hemorrhage. Subsequent pilot studies in carotid and in vertebrobasilar territory thrombotic stroke have demonstrated that recanalization can result when exogenous agents are infused just proximal to the cerebral artery occlusion by interventional neuroradiological techniques. This experience and the advent of fibrin-selective agents (tissue plasminogen activator [tPA] and single-chain urokinase plasminogen activator) have led to the development of a multicenter prospective safety/dose-ranging study of tPA in acute (less than eight hours from symptom onset) thrombotic stroke. Following initial clinical assessment, computed tomography scan, and angiography, each patient with a documented cerebral artery occlusion appropriate to the clinical syndrome receives a preassigned intravenous dose of tPA over 60 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Investigational use of tPA in acute stroke. 314 17


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>