| 1. |
- Lindgren, Arne, et al.
(författare)
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Electrocardiographic changes in stroke patients without primary heart disease
- 1994
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Ingår i: Clinical Physiology. - 1365-2281. ; 14:2, s. 223-231
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Tidskriftsartikel (refereegranskat)abstract
- Consecutive electrocardiograms were recorded in 28 stroke patients without signs of primary heart disease. Individuals with subarachnoidal haemorrhage, or electrolyte disturbances were excluded. A computerized tomography of the brain was performed in each case and showed a cerebral haemorrhage (n = 4), cortical infarction (n = 6), subcortical infarction (n = 14) and normal finding (n = 4). One patient developed atrial fibrillation but no other case of serious disturbances in rate of rhythm occurred. None developed AV block, bundle branch blocks or significant changes in QRS complexes. The most common abnormalities in ECG were transient STT changes in lateral leads, which were seen in 13 cases. The typical findings were flat or slightly negative T waves, horizontal or down-sloping ST segments and sometimes a small ST depression. In no case did ECG show typical signs of acute myocardial infarction. A transient prolonged QT interval was seen in three patients and transient U waves in four. ECG did not correlate to the location of the vascular lesion seen on CT or the clinical outcome. It is concluded that STT changes of a small magnitude are seen in about half of the cases of stroke patients without primary heart disease and that they do not resemble the typical pattern of acute myocardial ischaemia.
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| 2. |
- Rorsman, Ia, et al.
(författare)
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Reduction of visuo-spatial neglect with vestibular galvanic stimulation
- 1999
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Ingår i: Scandinavian Journal of Rehabilitation Medicine. - : Informa UK Limited. - 0036-5505. ; 31:2, s. 117-124
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the present investigation was to determine the effect of galvanic vestibular stimulation on visuo-spatial neglect without inducing nystagmus and associated discomfort. Fourteen patients with right-hemisphere stroke with neglect were assessed with two visuo-motor tasks ("Line crossing" and "Star cancellation") on three occasions. Seven of the subjects received galvanic vestibular stimulation during the second condition (Experiment 1), whereas the other seven received stimulation during the third assessment (Experiment 2). Between-group comparisons of stimulation effects were performed by analyzing change on visuo-spatial neglect from the first to the second condition in the two experimental groups. A significantly larger effect was demonstrated on the "Line crossing" task in Experiment 1. This finding suggests a stimulation effect beyond practice/spontaneous recovery, and may provide new possibilities in rehabilitation research because the stimulation can be given without discomfort.
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| 3. |
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| 4. |
- Ansved, Tor, et al.
(författare)
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Enzyme-histochemical and morphological characteristics of fast- and slow-twitch skeletal muscle after brain infarction in the rat
- 1996
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Ingår i: Journal of the Neurological Sciences. - 1878-5883. ; 144:1-2, s. 14-20
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Tidskriftsartikel (refereegranskat)abstract
- The right middle cerebral artery was permanently occluded in 12-week-old male spontaneously hypertensive rats. After the surgery the rats were subjected to repeated behavioural tests during the observation period. Fourteen weeks after surgery the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus muscle of both sides were removed and examined with regard to muscle fibre characteristics obtained by histochemical and morphometrical methods. Comparisons were made with age-matched controls. Limb placement and the ability to traverse a beam or a rotating pole were repeatedly tested 2-13 weeks after the operation. In spite of permanent sensorimotor deficits in limb placement and when traversing a rotating pole or beam, no increase in pathological changes was noted in either EDL or soleus. The number and proportion of fibre types remained unchanged in both muscles. There was no difference in muscle fibre size in either EDL or soleus. It is concluded that brain infarction in the rat, although causing marked impairment of contralateral motor function, does not have a major influence on the muscle-fibre morphology or fibre-type composition, irrespective of muscle type.
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| 5. |
- Grabowski, Martin, et al.
(författare)
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Brain capillary density and cerebral blood flow after occlusion of the middle cerebral artery in normotensive Wistar-Kyoto rats and spontaneously hypertensive rats
- 1993
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Ingår i: Journal of Hypertension. - 1473-5598. ; 11:12, s. 1363-1368
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In order to elucidate why spontaneously hypertensive rats (SHR) develop larger brain infarcts distal to an arterial occlusion than normotensive Wistar-Kyoto (WKY) rats, we determined the surface and volume densities of cerebral capillaries, and the regional cerebral blood flow distal to an arterial occlusion in SHR and WKY rats. DESIGN: Occlusion of the middle cerebral artery was chosen because the middle cerebral artery territory is most commonly affected by cerebral infarcts in man. METHODS: Surface and volume densities of capillaries in the neocortex of the middle cerebral artery territory were measured by stereological techniques on histological sections. Fifteen minutes after ligation of the right middle cerebral artery, regional cerebral blood flow was measured autoradiographically by the [14C]-iodoantipyrine method. RESULTS: The capillary density of the neocortex did not differ between the SHR and WKY rats. The blood flow was significantly lower within the middle cerebral artery territory in the SHR than in the WKY rats. CONCLUSIONS: The reduced blood flow distal to the occlusion in SHR is probably a consequence of structural adaptation of arterial resistance vessels, rather than being caused by reduced capillary density.
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| 6. |
- Grabowski, Martin, et al.
(författare)
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Fetal neocortical grafts implanted in adult hypertensive rats with cortical infarcts following a middle cerebral artery occlusion: ingrowth of afferent fibers from the host brain
- 1992
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Ingår i: Experimental Neurology. - 0014-4886. ; 116:2, s. 105-121
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Tidskriftsartikel (refereegranskat)abstract
- This study is focused on the survival of fetal neocortical grafts placed in the infarcted adult host cortex of the spontaneously hypertensive rat and describes the ability of host axonal regeneration into the graft after a focal ischaemic lesion. Five to seven days following ligation of the right middle cerebral artery, dissociated neocortical primordium from fetuses of gestational age 12-18 days was implanted into the infarcted cortical area. Surviving transplants were seen in all rats, although grafts derived from gestational age 12-14 days displayed an irregular morphology rich in sinusoid-like cavities and containing fewer cells of apparently mature neuronal morphology. Grafts from older donors contained perikarya of neuronal appearance; however, they lacked normal cortical lamination. Ten days postgrafting, fibers stained by acetylcholinesterase histochemistry, dopamine-beta-hydroxylase, and 5-hydroxytryptamine immunohistochemistry were found in the grafts, and by 10-23 weeks after transplantation the fiber density had increased substantially. When the retrograde tracer Fluoro-Gold was injected into the grafted tissue, labeled cells were found in several subcortical nuclei of the host, including the nucleus basalis of Meynert, ventral pallidum, thalamus, dorsal raphe, locus coeruleus, as well as the ipsilateral and contralateral neocortex. This study shows that grafts of dissociated neocortical tissue exhibit good survival and growth potential when implanted into infarcted neocortex and that several nerve fiber systems of the adult host have a regenerative capacity sufficient to innervate the grafted tissue.
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| 7. |
- Grabowski, Martin, et al.
(författare)
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Fetal neocortical grafts placed in brain infarcts do not improve paw-reaching deficits in adult spontaneously hypertensive rats
- 1996
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Ingår i: Acta Neurochirurgica. Supplementum. - 0065-1419. ; 66, s. 68-72
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to study if neural grafts placed brain infarcts could improve functional recovery. The middle cerebral artery was occluded (MCAO) in 19 spontaneously hypertensive rats. Nine rats were sham operated. Twelve to 16 days after the ischemic insult, 9 of the MCAO rats received transplants of dissociated fetal neocortical tissue (MCAO-T) and 1, 3 and 6 months after transplantation surgery, the rats were behaviorally evaluated by a test for forelimb function. Infarct and transplant sizes were measured morphometrically. The remaining volume of the infarcted hemisphere was 66 +/- 7% (mean +/- SD) in the MCAO group and 71 +/- 9% in the MCAO-T group of the non-operated hemisphere. All grafted rats had surviving transplants. Contralateral to the lesion, paw-reaching was highly impaired in both infarcted groups compared with sham-operated controls with no significant difference between MCAO and MCAO-T. The lesion size correlated significantly with contralateral paw-reach performance at all test periods. We conclude that neocortical grafts did not alleviate the impaired forepaw function.
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| 8. |
- Grabowski, Martin, et al.
(författare)
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Functional integration of cortical grafts placed in brain infarcts of rats
- 1993
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 34:3, s. 362-368
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Tidskriftsartikel (refereegranskat)abstract
- Five to 6 days after a right middle cerebral artery occlusion, a cell suspension of fetal neocortex was grafted into the infarcted area of adult spontaneously hypertensive rats. Three to 17 months later, functional integration of the grafts into the afferent somatosensory pathway was tested using the 2-[14C]deoxyglucose method for estimation of glucose utilization. Grafted rats (n = 8) and control rats (n = 5) with no arterial occlusion were stimulated in the left vibrissal region resulting in an increased glucose utilization in the left trigeminal sensory nucleus and the right ventroposterior nucleus of the thalamus, whereas the same regions in a group (n = 5) of nonstimulated grafted rats were not activated. Glucose uptake in the right somatosensory cortex of control rats was 96 +/- 5 (mean +/- SEM) mumol/100 gm/min. Neocortical grafts consumed less glucose than cortex in control rats but the vibrissae-stimulated group displayed a 110% higher value than the nonstimulated grafted group (32 +/- 5 vs 15 +/- 2, p < 0.05). We conclude that graft glucose metabolism is increased following stimulation of the host somatosensory pathway, which demonstrates that transplanted neurons can be functionally integrated with neural circuitries of the host after an ischemic insult.
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| 9. |
- Grabowski, Martin, et al.
(författare)
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Influence of an enriched environment and cortical grafting on functional outcome in brain infarcts of adult rats
- 1995
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 133:1, s. 96-102
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to study if enriched housing conditions and fetal neocortical transplantation could enhance the functional outcome after focal brain ischemia in adult rats. The right middle cerebral artery (MCA) was ligated in 34 inbred, spontaneously hypertensive male rats, which were then randomly divided into three groups. Groups A and B were transferred to an enriched environment, i.e., a large cage with opportunities for various activities but not forcing the rats to do any particular tasks; group C was kept in standard laboratory cages. Three weeks after the MCA occlusion blocks of fetal neocortical tissue (Embryonic Day 17) were transplanted to the infarct cavity in groups B and C. Rats in group A (n = 11) and group B (n = 11) performed equally well and significantly better than rats in group C (n = 10) when placed on an inclined plane and when traversing a rotating pole 6 and 9 weeks after the MCA occlusion and in a leg placement test at 9, but not 6 and 12 weeks. Skilled forelimb function did not differ between the groups. Infarct size and thalamic atrophy did not differ between the groups and graft size was similar in group B and C. There was no correlation between infarct size and motor function in any of the tests in rats housed in an enriched environment. Since the environment can significantly alter functional outcome without reducing infarct size we suggest that more attention should be given to the role of the laboratory environment and to long term behavioral outcome in experimental stroke.
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| 10. |
- Grabowski, Martin, et al.
(författare)
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Neocortical grafts placed in the infarcted brain of adult rats: few or no efferent fibers grow from transplant to host
- 1995
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Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 134:2, s. 273-276
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Tidskriftsartikel (refereegranskat)abstract
- The present study examines the capacity of fetal neocortical grafts placed in a brain infarct to exchange axonal projections with the host brain. Five to 7 days after a middle cerebral artery occlusion in adult spontaneously hypertensive rats, dissociated neocortical primordium from fetuses of gestational age 15-16 days was implanted into the infarcted area. Four to 11 months later, the neural tracers Phaseolus vulgaris-leucoagglutinin and Fluoro-Gold were injected in the grafts and host neocortex. An extensive axonal network was present in the transplants but only one of eight rats with appropriate placed injections displayed efferent connections from transplant to host. The sparse axonal outgrowth indicates major limitations for fetal rat cortical grafts to form connections with host neural circuitries after an ischemic insult.
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