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  • 1
    ISSN: 1432-1920
    Schlagwort(e): Key words Brain tumour, cystic ; Blood-brain barrier ; Oedema, cerebral
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chemical analysis of brain tumour cyst contents has invalidated the concept of cyst formation being the result of tumour necrosis, and a common mechanism of vasogenic brain oedema and cyst formation, namely blood-brain barrier (BBB) disruption, has been suggested. To analyse a possible relationship between the occurrence of vasogenic oedema and the presence of cysts, we performed a volumetric analysis on the MRI and CT studies of 60 patients with primary or metastatic brain tumours. We compared four groups of tumours: 30 gliomas, of which 15 were cystic and 15 not and 30 metastatic brain tumours of which 15 were cystic and 15 not. Although the mean volume of oedema was similar for cystic and noncystic tumours, the ratio of oedema to tumour volume was approximately four times as high in cystic supratentorial tumours. This would support the view that cyst formation may be related to relatively greater production of oedema, possibly due to fusion of microcysts containing oedema fluid. The ratio of oedema to tumour volume is not greater in cystic cerebellar and intraventricular tumours. This may be due to the different anatomical organization of the cerebellar white matter, and the fact that the intraventricular tumours are bordered by subcortical grey matter. In these cases, spread of oedema is impeded. Formation of a large amount of brain oedema is therefore not an essential prerequisite for cyst formation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 34 (1976), S. 1-6 
    ISSN: 1432-0533
    Schlagwort(e): Cerebral ischemia ; Blood-brain barrier ; Mongolian gerbils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The behaviour of the BBB in cerebral ischemia was studied in symptompositive Mongolian gerbils subjected to left common carotid artery occlusion using Evans Blue dye as indicator of BBB injury. The BBB damage was demonstrable grossly by the presence of areas of blue discoloration, and microscopically by the presence of a bright red fluorescent tracer, localized mostly in the neurons. The survey of various groups of animals revealed a direct relationship between the incidence and time of appearance of the BBB lesions and the duration of the ischemic occlusion. This relationship can be interpreted as another example of the previously described “maturation” phenomenon. A relatively late occurrence of the BBB injury in cerebral ischemia, at the time when the affected brain tissue shows severe, edematous histopathologic changes indicates that the brain edema, as the main complication of ischemia, could be regarded as being primarily of the cytotoxic type.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Acta neurochirurgica 139 (1997), S. 349-354 
    ISSN: 0942-0940
    Schlagwort(e): Arachnoid (cyst, granulation) ; meningioma ; progesterone receptors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We report 2 cases of arachnoid cysts, one with a retrocerebellar and the other with a left temporal localization, in which immunohistochemical studies had been conducted. The results of the immunohistochemistry on the presence of carcino-embryonic antigen (CEA) and glial fibrillary acidic protein (GFAP), and of the scanning- and transmission electron microscopy revealed the cyst lining to be identical to subdural neurothelium. Progesterone receptors were found in the nuclei of cells lining the cyst, which also suggests the similarity of the cyst lining to arachnoid granulations and meningiomas as derivatives of subdural neurothelium, which also possess progesterone receptors.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Acta neurochirurgica 95 (1988), S. 25-27 
    ISSN: 0942-0940
    Schlagwort(e): Blood-brain barrier ; survey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A survey is given on the history of the discovery of the blood-brain barrier, of its functions and of its clinical importance. Also attempts to circumvent or disrupt the barrier with the aim of introducing therapeutic or diagnostic agents into the brain tissue have been reported. Finally the possible negative effects of lasting barrier defects in transplanted foet al tissue are mentioned.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Acta neuropathologica 56 (1982), S. 99-112 
    ISSN: 1432-0533
    Schlagwort(e): Blood-brain barrier ; Hyperosmolar perfusion ; Immunoglobulin G
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Protein tracer flux from brain microvessels has been studied at intervals of 10 s and 5, 15 and 60 min following hyperosmolar perfusion injury of the blood-brain barrier with 0.6 ml of a 4 M urea solution. In one group of Wistar rats 75 mg horseradish peroxidase (HRP) was given intravenously 10 min before killing as an exogenous protein tracer. In another group endogenous IgG was used as tracer; to enhance serum levels and to facilitate demonstration, the rats were immunized with HRP beforehand, resulting in high titer serum antibodies of IgG class. After perfusion fixation and tracer demonstration in Vibratome sections the localization of the tracer was studied in 1 μm Epon sections and unstained ultrathin sections. The incidence of tracer presence was estimated with quantitative and statistical methods. The results indicate that in this experimental model of blood-brain barrier damage protein tracer extravasation only occurs during the first minutes and thus may be a rapidly reversible phenomenon. The signs of endothelial activation include increased numbers of vesicles and channel-like structures. As the ratio of vesicles with and without tracer remains fairly constant, increased vesicle formation seems to occur randomly in activated endothelial cells and thus does not represent a tracer outflow mechanism by itself. Any qualitative sign of endothelial activation and protein tracer uptake may occur with or without tracer passage into the surrounding brain, actual tracer extravasation thus appearing to be an overflow mechanism in endothelial cells that can be estimated only with quantitative methods. Protein tracer extravasation may occur by random uptake in vesicular or channel-like structures or by cytoplasmic pooling in endothelial cells or cell segments; tracer extravasation through interendothelial junctional areas is not substantiated by our results. Removal of extravasated tracer may occur at least in part by local tracer backflow into the lumina of larger vessles. And finally, the differences in extravasation pathways between HRP and IgG appear to be significant, demonstrating that more than one pathway may be involved and that the predominance of a pathway may at least in part be tracer dependent.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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