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Biomedical subjects

M Kaste

Publications and source records attributed to M Kaste.

At least 19 recordsLinked to original sources

Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. The European Cooperative Acute Stroke Study (ECASS)

OBJECTIVE: To evaluate the efficacy and safety of intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA) in patients with acute ischemic stroke. DESIGN: Randomized, prospective, multicenter, double-blind, placebo-controlled clinical trial. SETTING: A total of 75 hospitals in 14 European countries. PATIENTS: A total of 620 patients with acute ischemic hemispheric stroke and moderate to severe neurologic deficit and without major early infarct signs on initial computed tomography (CT). INTERVENTION: Patients were randomized to treatment with 1.1 mg per kilogram of body weight of rt-PA (alteplase) or placebo within 6 hours from the onset of symptoms. OUTCOME MEASURES: Primary end points included Barthel Index (BI) and modified Rankin Scale (RS) at 90 days. Secondary end points included combined BI and RS, Scandinavian Stroke Scale (SSS) at 90 days, and 30-day mortality. Tertiary end points included early neurologic recovery (SSS) and duration of in-hospital stay. Safety parameters included mortality and incidence of intracranial or extracranial hemorrhage. RESULTS: The distribution of demographic variables was similar among patients in the rt-PA and placebo treatment arms in both the intention-to-treat (ITT) analysis and the explanatory analysis for the target population (TP). A total of 109 patients (17.4%) were included in the trial despite major protocol violations but excluded from the TP. There was no difference in the primary end points in the ITT analysis, while the TP analysis revealed a significant difference in the RS in favor of rt-PA-treated patients (P = .035). Of the secondary end points, the combined BI and RS showed a difference in favor of rt-PA-treated patients in both analyses (P < .001). Neurologic recovery at 90 days was significantly better for rt-PA-treated patients in the TP (P = .03). The speed of neurologic recovery assessed by the SSS was significantly better up to 7 days in the ITT analysis and up to 30 days for the TP in the rt-PA treatment arm. In-hospital stay was significantly shorter in the rt-PA treatment arm in both analyses. There were no statistically significant differences in the mortality rate at 30 days or in the overall incidence of intracerebral hemorrhages among the rt-PA and placebo treatment arms in either analysis. However, the occurrence of large parenchymal hemorrhages was significantly more frequent in the rt-PA-treated patients. CONCLUSIONS: Intravenous thrombolysis in acute ischemic stroke is effective in improving some functional measures and neurologic outcome in a defined subgroup of stroke patients with moderate to severe neurologic deficit and without extended infarct signs on the initial CT scan. However, the identification of this subgroup is difficult and depends on recognition of early major CT signs of early infarction. Therefore, since treating ineligible patients is associated with an unacceptable increase of hemorrhagic complications and death, intravenous thrombolysis cannot currently be recommended for use in an unselected population of acute ischemic stroke patients.

Acute Disease

Arg506Gln factor V mutation (factor V Leiden) in patients with ischaemic cerebrovascular disease and survivors of myocardial infarction.

The point mutation Arg506- > Gln of factor V was recently shown to be an important and relatively common genetic cause of venous thromboembolism. Using a DNA technique based on polymerase chain reaction, we surveyed the blood samples of 236 patients with ischaemic stroke or a transient ischaemic attack, 122 survivors of myocardial infarction and 137 control subjects for the presence of this mutation. Although the frequency of the factor V mutation in patients with arterial disease (4.5%) was not significantly different from that in healthy blood donors (2.9%), a carrier status for this mutant gene was associated with symptoms of migraine and relatively mild angiographic abnormalities among patients with cerebrovascular disease. A more extensive study addressing the occurrence and significance of the mutant factor V mutation in patients with vasospastic cerebrovascular diseases seems to be warranted.

Adult

Snoring, sleep apnea syndrome, and stroke.

Increasing evidence suggests that snoring and sleep apnea are associated with cerebrovascular diseases. Several other factors may be involved in this association because many established or potential risk factors for stroke are related to snoring and sleep apnea. These include arterial hypertension, coronary heart disease, age, obesity, smoking, and alcohol consumption. Recent epidemiologic and clinical studies indicate, however, that snoring can increase the risk of stroke independently of these confounding factors. Accumulating epidemiologic evidence of long-term harmful effects of the obstructive sleep apnea syndrome appears to be related to increasing vascular morbidity and mortality. Potential mediators among snoring, obstructive sleep apneas, and stroke include cardiac arrhythmias and other hemodynamic disturbances, increased levels of catecholamines, and disturbances in cerebral blood flow caused by sleep apneas, as well as hypoxemic periods that may potentiate atherosclerosis.

Cardiovascular Diseases

Regional cerebral blood flow after human cardiac arrest. A hexamethylpropyleneamine oxime single photon emission computed tomographic study.

We studied 30 patients 24 hours after out-of-hospital cardiac arrest and 13 age-matched normal controls with the use of technetium Tc 99m-hexamethylpropyleneamine oxime single photon emission computed tomography. All patients were followed up for 12 months or until death. Frontal hypoperfusion (anteroposterior perfusion ratio, less than 0.90) was observed in 23 patients (77%). In eight patients who remained comatose and died, the total size of perfusion defects was larger (38% +/- 20%) than in the 21 patients who recovered consciousness (24% +/- 14%), but the anteroposterior ratio was similar in both of these patient groups (0.83 +/- 0.09) and significantly lower than in the controls (0.96 +/- 0.03). During follow-up, both the anteroposterior perfusion ratio and the relative defect size improved, but frontal hypoperfusion was still observed in seven of 13 patients. After cardiac arrest, regional cerebral blood flow is characterized by frontal hypoperfusion that tends to improve over time but that persists in most patients.

Adult

Effects of exercise and ethanol ingestion on platelet thromboxane release in healthy men.

We studied the effects of repeated bicycle exercises and ethanol ingestion (1.5 g/kg) on platelet aggregation and thromboxane (TxB2) release in 10 healthy male volunteers. After a bicycle exercise performed in the morning, the adenosine diphosphate (ADP)-induced platelet aggregation and the aggregation-associated thromboxane release were found to be decreased in fasting men. In contrast, after ingestion of fruit juice and a second exercise at noon, platelet aggregation and thromboxane release were increased. These latter changes were negligible when ethanol was ingested together with fruit juice. A third exercise, performed in the evening, again caused a decrease in the aggregation and associated thromboxane release during the control session, but provoked an increase during the ethanol session. Exercise increased the urinary excretion of 2,3-dinor-6-keto-PGF1 alpha. Changes in the plasma arachidonic acid (AA) concentration probably influenced the platelet thromboxane release. The results suggest that both physical exercise and ingestion of ethanol in fruit juice influence the ADP-stimulated platelet thromboxane release.

Adenosine Diphosphate

Angiographic vasospasm and release of platelet thromboxane after subarachnoid hemorrhage.

We studied adenosine diphosphate-induced platelet aggregation and the associated release of thromboxane B2 in 49 patients with subarachnoid hemorrhage in relation to angiographic vasospasm. Postoperative cerebral angiography was performed less than or equal to 3 (median 1) days after surgery for an aneurysm 5-14 days after subarachnoid hemorrhage. Correspondingly, one sample from each patient was taken within 24 hours either before or after angiography. The occurrence of severe as well as diffuse, moderate, or severe angiographic vasospasm was associated with the presence of delayed cerebral ischemia (p less than 0.05). Patients with diffuse angiographic vasospasm had significantly higher (p less than 0.05) values for thromboxane B2 release than the others, even after adjustment by the clinical grades on admission and before surgery, the timing of surgery, the time from subarachnoid hemorrhage to angiography and blood sampling, and nimodipine therapy. Severe and diffuse angiographic vasospasm were also associated with poor outcome at 1 year (p less than 0.05). Our results suggest that augmented release of platelet thromboxane may be involved in the pathogenesis of vasospasm in large cerebral arteries.

Adenosine Diphosphate

Reduced platelet aggregability and thromboxane release after rebleeding in patients with subarachnoid hemorrhage.

Serial blood samples were obtained from 80 patients with subarachnoid hemorrhage (SAH) to study adenosine diphosphate-induced platelet aggregation and associated thromboxane B2 release. The goal of the investigation was to detect whether reduced platelet function is involved in rebleeds. Seventeen patients (21%) suffered a rebleed, six of those experiencing their first rebleed within 24 hours after SAH. Therefore, most platelet function studies were performed after rebleeds. Thromboxane release was lower in patients with rebleeds than in the others, both before and after rebleeding, although statistical significance was reached only in samples collected after rebleeds. Patients rebleeding within 24 hours after SAH had lower platelet aggregability (p = 0.037) than patients without a rebleed in the samples taken within 3 days after SAH. The results suggest that reduced platelet aggregability and thromboxane release are involved in rebleeds following primary SAH.

Adenosine Diphosphate

Platelet thromboxane release and delayed cerebral ischemia in patients with subarachnoid hemorrhage.

Adenosine diphosphate-induced platelet aggregation and associated thromboxane B2 release were studied in 52 patients with subarachnoid hemorrhage (SAH) in order to detect a possible association between altered platelet function and development of cerebral ischemic complications after SAH. Compared to the values on admission, the patients showed significantly increased platelet aggregability (p less than 0.05) and thromboxane release (p less than 0.001) 1 to 2 weeks after SAH. The highest values of thromboxane release were seen in patients who deteriorated due to delayed cerebral ischemia with a permanent neurological deficit. Thromboxane release was significantly higher (p less than 0.05) before the onset of severe delayed ischemia in six patients with preoperative ischemia compared to the patients without delayed ischemia. In five others, both ischemic deterioration and elevated thromboxane release occurred after operation. These patients had preoperative values similar to the values in those without ischemic symptoms. The observations suggest that increased platelet aggregability and thromboxane release are associated with delayed cerebral ischemia both before and after surgery.

Adult

Nimodipine after resuscitation from out-of-hospital ventricular fibrillation. A placebo-controlled, double-blind, randomized trial.

One hundred fifty-five consecutive patients resuscitated after out-of-hospital ventricular fibrillation by a physician-manned advanced life support unit were randomly assigned to receive nimodipine or placebo at a dosage of 10 micrograms/kg as an intravenous injection immediately after restoration of spontaneous circulation, followed by an infusion of 0.5 micrograms/kg per minute for 24 hours. No significant difference was found in the 1-year survival rate of nimodipine-treated (30 [40%] of 75 patients) and placebo-treated patients (29 [36%] of 80 patients). Recurrent ventricular fibrillation during the treatment occurred in one patient in the nimodipine group compared with 12 patients in the placebo group. In a post hoc analysis of patients with very long delays in advanced life support (more than 10 minutes), the 1-year survival rate was higher with nimodipine (eight [47%] of 17 patients) than with placebo (two [8%] of 26 patients). Nimodipine may be of benefit in patients with delayed resuscitation.

Aged

Platelet thromboxane release after subarachnoid hemorrhage and surgery.

We studied adenosine diphosphate-induced platelet aggregation and the associated release of thromboxane B2 in platelet-rich plasma from 88 patients with subarachnoid hemorrhage and 26 healthy controls. During the first 3 days after subarachnoid hemorrhage, the patients showed significantly decreased (p less than 0.05) platelet aggregability and thromboxane release relative to the controls, but these effects disappeared in a few days. Platelet count increased for 3 weeks after subarachnoid hemorrhage. Surgery in 67 patients was followed by significant increases in platelet aggregability (p less than 0.05) and thromboxane release (p less than 0.001). Greatest thromboxane release was found in the eight patients showing delayed (postoperative) ischemic deterioration with a permanent neurologic deficit. Although platelet hyperaggregability and increased thromboxane release were particularly prominent in these eight patients, the role of these hematologic parameters in the pathogenesis of delayed ischemic deterioration remains unclear.

Adult

Effect of nimodipine on platelet function in patients with subarachnoid hemorrhage.

We studied platelet function in 41 patients with subarachnoid hemorrhage who were randomized to receive either nimodipine or placebo in a double-blind fashion. Nimodipine was given to 21 patients, intravenously for 7-10 days and then orally until 21 days after the subarachnoid hemorrhage. The other 20 patients received placebo in a similar manner. Nimodipine did not significantly influence platelet aggregability. For the first 1-5 days after the subarachnoid hemorrhage, nimodipine treatment did not have any notable effect on adenosine diphosphate-induced platelet thromboxane B2 release, but a significant (p less than 0.05) inhibitory effect was observed thereafter. During intravenous administration, nimodipine prevented the increase in thromboxane release otherwise observed after subarachnoid hemorrhage. Concomitant with the decrease in thromboxane release, nimodipine increased the platelet count both before and after surgery so that the capacity for thromboxane formation per liter of blood decreased less than expected on the basis of thromboxane release per 10(7) platelets. Our study suggests that nimodipine might diminish the chance of cerebral ischemia by inhibiting platelet thromboxane release.

Adult

Alcohol abuse and brain infarction.

Recent findings on the relation between alcohol abuse and ischaemic brain infarction are reviewed. Much of the association has hitherto been explained by the effects of confounding factors such as smoking. Alcohol increases blood pressure in both hypertensive and normotensive subjects and alcohol induced hypertension enhances the risk of both hemorrhagic and ischaemic strokes. Analysis of case histories shows that alcohol abuse has precipitated cerebral embolism in conjunction with cardiac diseases including alcoholic cardiomyopathy and paradoxical embolism due to deep vein thrombosis via atrial septal defect. Among young adults, falling when intoxicated with alcohol has caused traumatic dissection of the carotid artery and consequent brain infarction. Alcohol may predispose individuals to cerebral embolism, thrombosis and ischaemia via its effects on the coagulation cascade, platelet count and function and contractility of the cerebral vessels. Further studies are needed to prove that these mechanisms are significant and to identify any other mechanisms which may mediate the risk associated with alcohol abuse. On the basis of current data, alcohol should be considered as an independent risk factor for ischaemic cerebral infarction in young adults.

Alcohol Drinking

Neurological outcome after out-of-hospital cardiac arrest. Prediction by cerebrospinal fluid enzyme analysis.

The prognostic value of cerebrospinal fluid (CSF) and serum neuron-specific enolase and brain-type creatine kinase isozyme (CK-BB) measurements was studied in 75 consecutive victims of out-of-hospital cardiac arrest. All patients with a CSF neuron-specific enolase level of more than 24 ng/mL 24 hours after cardiac arrest remained unconscious and died. The CSF CK-BB level was as reliable as an index of brain injury. Cerebrospinal fluid neuron-specific enolase, CSF CK-BB and serum neuron-specific enolase levels correlated with the neurological outcome at 3 months. Thus, the analysis of these enzymes in CSF seems to be useful in the early prognostic assessment of cardiac arrest victims.

Adult

Dental infections in association with cerebral infarction in young and middle-aged men.

The association between dental infections and cerebral infarction was investigated in a case-control study involving 40 patients with ischaemic cerebral infarction under the age of 50, and 40 randomly selected community controls matched for sex and age. Poor oral health, as assessed by two indices measuring the severity of infections of teeth and periodontium, or by the presence of subgingival calculus or the presence of suppuration in the gingival pockets, were more common in male patients than in male controls, but no difference was observed in females. If severe dental infections were combined with other probable bacterial infections there were altogether 16 patients (40%) but only two controls (5%) who had suffered from a probable bacterial infection within 1 month or at the time of the stroke or when examined as a control (P less than 0.01). Our results suggest an association between bacterial infection and ischaemic cerebrovascular disease in patients under 50 years of age. Severe chronic dental infection seems to be an important type of infection associated with cerebral infarction in males.

Adolescent

The effects of earlier surgery and shorter bedrest on the outcome in patients with subarachnoid haemorrhage.

The effects of earlier surgery and shorter bedrest on the outcome in 338 consecutive patients with subarachnoid haemorrhage admitted within five years to a primary emergency hospital were evaluated. Mortality from rebleeds diminished more than surgical mortality increased. Shortened bedrest did not increase the number of rebleeds in patients not operated on. The combined mortality from rebleed and surgery decreased by 32% and the overall mortality by 21%.

Activities of Daily Living