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Biomedical subjects

G Boysen

Publications and source records attributed to G Boysen.

At least 109 records · Page 6Linked to original sources
PubMed1992

Reduction of infarct volume and mortality by thrombolysis in a rat embolic stroke model.

BACKGROUND AND PURPOSE: Thrombolytic therapy with recombinant tissue plasminogen activator was tested in a rat embolic stroke model. METHODS: The rat carotid territory was embolized with arterial-like microthrombi formed under pressure. Hemispheric cerebral blood flow before and after embolization was measured by the intraarterial Xenon-133 injection method. Fifteen minutes after embolization, 24 rats were treated with 3 mg/kg or 10 mg/kg tissue plasminogen activator, and 27 were treated with saline. Carotid angiography displayed the rate of occlusion of the cerebral arterial supply before and after treatment. Brains were fixed and evaluated neuropathologically and infarct volume was measured. RESULTS: Cerebral blood flow was reduced 70-86% after embolization. The comparison of pretreatment and posttreatment angiography showed significant (p = 0.0005) reperfusion in the treated rats. Thrombolytic therapy significantly reduced the infarct volume from 55.1% to 24.4% of embolized hemisphere volume (p = 0.007) and increased the survival rate from 0.48 to 0.96 (p = 0.0004). Fifty-three percent of the embolized rats recanalized completely after thrombolytic treatment and developed almost no infarction (median volume 2.8%), and all survived. No hemorrhagic complications were observed. CONCLUSIONS: Early thrombolytic therapy induced recanalization and reduced mortality and infarct volume after embolic stroke in this model.

Animals↗
PubMed1991

[Atrial fibrillation--thromboembolism and prevention].

Chronic non-rheumatic atrial fibrillation is associated with a risk of thromboembolic complications of about 5% per year. Previous myocardial infarction seems to be a significant risk factor for development of thromboembolic complications in chronic atrial fibrillation, whereas paroxysmal atrial fibrillation and isolated atrial fibrillation in younger patients may be associated with a lower risk of emboli. Silent cerebral infarction occurs more often in chronic atrial fibrillation than among controls in sinus rhythm. Three prospective trials of patients with atrial fibrillation found effect of warfarin on the occurrence of thromboembolic complications. In one study aspirin 325 mg daily was effective in patients below 75 years of age, but not in patients above this age. The other trials revealed no effect of aspirin.

Aged↗
PubMed1991

Cytotoxic activity in plasma from patients with amyotrophic lateral sclerosis.

The present study evaluates an assay of cytotoxic effect of plasma from patients with amyotrophic lateral sclerosis. Plasma from 20 recently diagnosed ALS patients induced hemolysis of normal red blood cells with a significantly greater intensity than that of normal controls. After at least 1 month of treatment with prednisone and azathioprine, the hemolytic activity of ALS plasma was reduced but was still higher than that of control plasma.

Aged↗
PubMed1990

Aniracetam tested in chronic psychosyndrome after long-term exposure to organic solvents. A randomized, double-blind, placebo-controlled cross-over study with neuropsychological tests.

In order to examine if the nootropic drug, aniracetam, was capable of improving cognitive performance, 44 subjects suffering from chronic psychosyndrome after long-term exposure to organic solvents were included in a randomized, double-blind, placebo-controlled, cross-over study. The treatment periods were 3 months with aniracetam 1 g daily and 3 months with placebo. Neuropsychological tests as well as a physical and neurological examination were performed at entry into the study and after each treatment period, together with an evaluation of the subjects' overall condition. Neither the doctors' nor the subjects' own assessment of the overall condition indicated that the trial medication had had any effect. No significant changes in neuropsychological symptoms were observed. A statistically significant difference in favour of antiracetam was found in only 1 of the 19 neuropsychological test measures, namely a test for constructional ability. However, in another test on visuo-spatial function, a statistically significant result was found in favour of placebo. Thus, aniracetam was found to be ineffective in the treatment of subjects suffering from chronic psychosyndrome after long-term exposure to organic solvents.

Adult↗
PubMed1990

Thrombolytic therapy of cerebral arterial occlusion with recombinant tissue plasminogen activator.

This report describes three patients, with acute cerebral arterial occlusion, treated with recombinant tissue plasminogen activator (rt-PA). In one patient with basilar artery occlusion thrombolytic treatment was initiated 12 h after onset of the symptoms. In two patients with angiographically verified occlusion of the middle cerebral artery, the treatment was initiated approximately 4.5 h after onset of the symptoms. Recombinant tissue plasminogen activator 80-120 mg, was infused intra-arterially over 90-100 min via a catheter the tip of which was close to the occlusion. This regimen resulted in recanalization in all the patients; however, in two patients it was verified by repeat CT scan only. In two patients the thrombolytic treatment was successful (the patients improved clinically); the third patient died of massive cerebral infarct-related oedema. In none of the patients did significant bleeding or other obvious side-effects occur. From this preliminary report it is concluded that angiographically proven thrombolytic recanalization in acute cerebrovascular occlusion is possible with rt-PA. In some patients, however, the treatment is initiated too late. Further investigation of the possible indication for thrombolytic therapy in stroke is needed.

Adult↗
PubMed1990

Immunosuppressive treatment of patients with amyotrophic lateral sclerosis.

Documented treatment for amyotrophic lateral sclerosis (ALS) is not available. Several studies have suggested an immunological etiology and an effect on the course of disease, when ALS-patients were treated with immunosuppressants. The aim of the present study was to evaluate the effect of immunosuppressive therapy in ALS-patients comparing the course of disease in treated patients and in historic controls with ALS; 21 patients were included in the study, 17 men and 4 women. Median age at admission was 54 years for men and 61 years for women. 5 had progressive bulbar palsy, 7 both upper and lower motor neuron affections and 9 progressive muscular atrophy. Patients were treated with prednisolone and azathioprine for 1 year and examined regularly; 12 were treated and followed for more than a year. No definite difference between survival in treated patients and their controls was found.

Administration, Oral↗
PubMed1990

Risk factors for thromboembolic complications in chronic atrial fibrillation. The Copenhagen AFASAK study.

As previously reported, 1007 patients with chronic atrial fibrillation participated in the Copenhagen AFASAK study. Before inclusion to trial, they all had a physical examination, chest roentgenogram, and echocardiogram with determination of left atrial size. This study evaluated the importance of cardiovascular risk factors for development of thromboembolic complications. To exclude any treatment effects on occurrence of thromboembolic complications, we included only the 336 patients from the placebo group. Using Cox's regression model, previous myocardial infarction was a significant risk factor for development of thromboembolic complications. Age, gender, heart failure, chest pain, hypertensive heart disease, diabetes, systolic and diastolic blood pressure, smoking, relative heart volume, and left atrial size were all without statistical importance.

Aged↗
PubMed1989

Placebo-controlled, randomised trial of warfarin and aspirin for prevention of thromboembolic complications in chronic atrial fibrillation. The Copenhagen AFASAK study.

From November, 1985, to June, 1988, 1007 outpatients with chronic non-rheumatic atrial fibrillation (AF) entered a randomised trial; 335 received anticoagulation with warfarin openly, and in a double-blind study 336 received aspirin 75 mg once daily and 336 placebo. Each patient was followed up for 2 years or until termination of the trial. The primary endpoint was a thromboembolic complication (stroke, transient cerebral ischaemic attack, or embolic complications to the viscera and extremities). The secondary endpoint was death. The incidence of thromboembolic complications and vascular mortality were significantly lower in the warfarin group than in the aspirin and placebo groups, which did not differ significantly. 5 patients on warfarin had thromboembolic complications compared with 20 patients on aspirin and 21 on placebo. 21 patients on warfarin were withdrawn because of non-fatal bleeding complications compared with 2 on aspirin and none on placebo. Thus, anticoagulation therapy with warfarin can be recommended to prevent thromboembolic complications in patients with chronic non-rheumatic AF.

Adult↗
PubMed1989

Cerebral blood flow before and after cardioversion of atrial fibrillation.

In nine patients with atrial fibrillation (AF) of less than 3 months' duration, CBF was measured the day before and after and again 30 days after electrical cardioversion therapy to sinus rhythm. The day before cardioversion therapy, median CBF (expressed as initial slope index 1, ml/100 g.min-1) was 35.8 and the day after it was 37.1. After 30 days in sinus rhythm, CBF was 39.4 (NS), although the end-tidal PCO2 values were lower than the pretreatment values. After correction for changes in end-tidal PCO2, the median CBF had increased significantly from 35.8 to 40.3 on day 1 and to 46.7 on day 30. The reduced CBF during AF could be a contributing factor in the development of cerebrovascular complications in patients with AF.

Adult↗
PubMed1989

Echocardiography and cerebral computed tomography in chronic atrial fibrillation.

Chronic atrial fibrillation (CAF) may be complicated by asymptomatic small silent cerebral infarctions as well as by stroke. The echocardiographic findings in 29 patients with CAF and 29 controls in sinus rhythm are presented. The cerebral computed tomography (CT) findings in these patients were previously published and significantly more small low-density lesions, probably reflecting previous infarctions, were found in patients with CAF than in controls. The aim of the present study was to evaluate if patients with such cerebral lesions had characteristic echocardiographic abnormalities with special reference to patients with CAF. No significant differences could be detected between the groups with and without cerebral lesions regarding the occurrence of valvular heart disease, left ventricular dysfunction, end-diastolic diameter of the left ventricle, left atrial dimension and left ventricular fractional shortening. Only seven patients with CAF (24%) compared with 21 in sinus rhythm (72%) had normal echocardiograms (P less than 0.001). In conclusion, echocardiography gave no guidance to why some patients developed cerebral low-density areas on CT.

Aged↗
PubMed1989

Sleep disturbances in torture survivors.

One of the main complaints in torture survivors is sleep disturbance with nightmares, too little sleep and daytime fatigue. Seven subjects, who had been exposed to torture from 6 months to seven years previously, were examined by polysomnography. All had abnormal sleep patterns compared with normal age- and sex-matched controls. The subjects woke frequently from REM sleep, had reduced REM sleep duration, absent Stage 4 sleep, short total sleep time and low sleep efficiency. This study revealed that previously healthy young persons subjected to extreme stress may develop an abnormal sleep pattern.

Adult↗
PubMed1989

Neuropeptides and neural cell adhesion molecule (NCAM) in CSF from patients with ALS.

In 10 patients with amyotrophic lateral sclerosis (ALS), the CSF content of the neuropeptides vasoactive intestinal polypeptide (VIP) and cholecystokinin (CCK) as well as neural cell adhesion molecule (NCAM) was investigated. Compared with normal controls, no deviations were found in CCK or NCAM, while the values of VIP were significantly lower in ALS patients. This finding may reflect a loss of motor neurons.

Adult↗
PubMed1989

Cerebral computed tomography in paroxysmal atrial fibrillation.

Atrial fibrillation (AF) is associated with an increased risk of stroke. In patients with chronic AF, without clinically known cerebrovascular disease, computed tomography (CT) has revealed a high frequency of abnormal low-density areas suggesting old asymptomatic infarcts. To investigate the frequency of such lesions in paroxysmal AF, 30 patients with paroxysmal AF and 30 controls matched in sinus rhythm, without history of cerebrovascular disease, were CT scanned. Four patients with paroxysmal AF (13%) and 3 controls (10%) had abnormal CT scans with areas of low density with sharp demarcation from surrounding tissue. The abnormal areas probably reflected small, clinically silent infarcts. There were no differences between paroxysmal AF and controls in number and size of abnormal areas with apparent tissue loss. In contrast to chronic AF, the risk of such lesions in paroxysmal AF does not seem to be increased compared with matched sinus rhythm controls. This is in agreement with the clinical experience of a low risk of stroke in paroxysmal AF.

Adult↗