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- Agardh, Carl-David, et al.
(författare)
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The influence of hypothermia on hypoglycemia-induced brain damage in the rat
- 1992
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 83:4, s. 379-385
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Tidskriftsartikel (refereegranskat)abstract
- The effects of hypothermia on hypoglycemic brain damage were studied in rats after a 30-min period of hypoglycemic coma, defined as cessation of spontaneous EEG activity. The rats were either normothermic (37 degrees C) or moderately hypothermic (33 degrees C). Morphological brain damage was evaluated after various periods of recovery. Hypothermic animals with halothane anesthesia never resumed spontaneous respiration, thus requiring artificial ventilation during recovery (maximally 8 h). In contrast, when isoflurane was used as the anesthetic agent, all animals survived and were examined after 1 week of recovery. There was a tendency towards gradually higher arterial plasma glucose levels during hypoglycemia with lower body temperature. The time period from insulin injection until isoelectric EEG appeared was gradually prolonged by hypothermia, and was shorter when isoflurane was used for anesthesia. Brain damage was examined within the neocortex, caudoputamen and hippocampus (CA1, subiculum and the tip of the dentate gyrus). Damage to neurons was found to be of two types, namely condensed dark purple neurons (pre-acidophilic) and shrunken bright red-staining neurons (acidophilic). In the neocortex, no clear influence of temperature on the degree of injury was seen. In the caudoputamen, the number of injured neurons clearly decreased at lower temperature (33 degrees C, P less than 0.001) when halothane was used, while no such difference was seen when isoflurane was used as the anesthetic agent. Likewise, a protective effect of hypothermia was seen in subiculum (P less than 0.01) when halothane, but not isoflurane was used.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 2. |
- Lexell, Jan, et al.
(författare)
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The occurrence of fibre-type grouping in healthy human muscle: a quantitative study of cross-sections of whole vastus lateralis from men between 15 and 83 years
- 1991
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Ingår i: Acta Neuropathologica. - 1432-0533 .- 0001-6322. ; 81:4, s. 377-381
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Tidskriftsartikel (refereegranskat)abstract
- Methods that objectively assess the muscle fibre-type arrangement may improve the detection of fibre-type grouping, a diagnostic sign of a denervation and reinnervation process. To distinguish between a diseased and a normal muscle, there is a need for quantitative data on the fibre-type arrangement in healthy human muscles at different ages. In this study, cross-sections were prepared of whole autopsied vastus lateralis muscle from 24 previously physically healthy men, aged 15 to 83 years. The arrangements of type 1 and type 2 fibers were assessed in terms of the number of enclosed fibres in individual fascicles throughout each muscle. Recent improvements to the enclosed fibre method were used to define measures of randomness which facilitated the combination of several sample areas and the quantification of the fibre-type arrangements. Segregation was typical for young muscles, randomness was most common between 30 and 50 years of age, while some fibre-type grouping was considered "normal" in old muscles. The arrangements of type 1 and type 2 fibres were quantitatively similar, irrespective of the age of the individual. The results imply that the fibre population changes considerably during a lifetime, and that it undergoes a continuous denervation and reinnervation process with normal ageing. Because of its importance, age should be accommodated in the analysis of a muscle sample, irrespective of the statistical model and method used.
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| 3. |
- Nordborg, Claes, et al.
(författare)
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The relationship between plasma protein extravasation and remote tissue changes after experimental brain infarction
- 1991
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Ingår i: Acta Neuropathologica. - 1432-0533. ; 82:2, s. 118-126
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Tidskriftsartikel (refereegranskat)abstract
- Extravasated endogenous serum albumin and fibrinogen were identified immunohistochemically in coronal brain sections from normotensive Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) after permanent ligation of the right middle cerebral artery. Infarcts were seen in all the SHR but only in 6 out of 14 WKY. Six hours after ligation, extravasated proteins were located primarily within the borders of the infarcts whereas after 24 h and later there was an increasing spread in the white matter. After 7 days, a protein immunoreactivity was seen far outside the infarcted areas, mainly in the white matter and occasionally extending somewhat into the contralateral side. Three weeks after permanent ligation, the immunoreactivity for plasma proteins had a similar extension but was less intense than after 7 days. A gliosis was noted within the protein-positive regions. From 72 h and onwards the immunoreactivity for albumin but not for fibrinogen extended via the white matter into the ipsilateral thalamic nuclei, where marked, mainly cytolytic nerve cell damage and gliosis was found. The close spatial correlation with albumin immunopositivity and the histological features of the thalamic lesions indicate that the propagation of extravasated plasma constituents or degradation products from the infarct may influence the character, timing and extent of remote tissue changes after cerebral infarction.
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