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  • 1
    ISSN: 1432-1920
    Keywords: Pituitary adenoma ; MRI ; Immunohistochemistry ; Pituitary hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Our aim was to elucidate the factors which determine the MRI signal intensities of pituitary adenomas. We examined 51 patients with surgically-confirmed pituitary adenomas. Using a spin-echo pulse sequence (SE 500/15), coronal and sagittal images (3 mm slices) were obtained. Signal intensities on T1-weighted images were measured in the parenchyma of the adenoma and in normal grey matter. The relative intensity of the adenoma was assessed by calculating the ratio of its signal intensity to that of the normal grey matter of the same patient. Parafin-embedded sections were used for haematoxylin and eosin staining. The number of cells in a prescribed area was counted, and the mean of five such counts was taken as the cell density. Immunohistochemically stained sections using antibodies for various pituitary hormones were similarly examined; the ratio of the total number of hormone-positive cells to the overall total number of adenoma cells was calculated. Four independent variables were used in the analysis: the age of the patient, the maximum diameter of the adenoma, the cell density and the proportion of hormone-positive cells in the adenoma and, with the signal intensity ratio as the dependent variable, a multiple regression analysis was performed. This revealed that the the greatest influence upon the signal intensities on T1-weighted images was the proportion of hormone positive cells.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 77 (1988), S. 33-38 
    ISSN: 1432-0533
    Keywords: Rathke's cleft cyst ; Immunohistochemistry ; Pituitary hormones ; Intermediate filament ; Squamous metaplasia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An immunohistochemical study was made of ten cases of asymptomatic and three cases of symptomatic Rathke's cleft cyst. The cysts in the asymptomatic cases had monolayer columnar or cuboidal epithelium. Within the epithelium, cells which were positive for at least one of the pituitary hormones were found. The rate of positive reactions for these six pituitary hormones was between 70% and 100%. In contrast, the cysts in the symptomatic cases had an epithelium which was partly stratified squamous and partly squamous epithelium, and none of the pituitary hormones were found in them. Therefore, when a Rathke's cleft cyst enlarges to the extent that clinical symptoms are produced, we consider that changes have already occurred in structure and function of the cyst epithelium. In addition, we believe there is a tendency for monolayer epithelia to undergo squamous metaplasia and for cells which are positive for pituitary hormones to change into non-granulated cells.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 58 (1981), S. 149-160 
    ISSN: 0942-0940
    Keywords: Brain swelling ; mannitol ; perfluorochemicals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using the incomplete cerebral hemisphere infarction in dogs, we have been able to produce brain swelling in all animals after six hours of vascular occlusion followed by recirculation of blood. The current study tested the effects of mannitol, perfluorochemicals (FC), and inhalation of oxygen in various combinations on such brain swelling. 1. Mannitol alone, FC alone, and FC together with oxygen were ineffective. Mannitol together with oxygen was to some extent effective in suppressing brain swelling. 2. Mannitol followed by FC was effective in suppressing brain swelling, and this effectiveness was further enhanced by inhalation of oxygen. 3. Noteworthy is the fact that among these experimental groups, there were animals in which brain swelling was severe, yet extravasation of Evans blue was slight and, contrarily, animals in which brain swelling was slight but extravasation severe.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0942-0940
    Keywords: Cerebral ischaemia ; mannitol ; fluorocarbon emulsion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using the “canine model of complete ischemic brain regulated with a perfusion method” in which it is possible to control the degree of blood flow to a cerebral hemisphere via a perfusion pump, the effects of mannitol (which acts as a free radical scavenger) and fluorcarbon emulsion (FC) (which has 0.1 μm of average particle size and a high oxygen-carrying capacity) on cerebral ischaemia were investigated. After pretreatment with the drugs, blood flow was reduced via the pump to 1/10 the normal state and 1 hour later, return to a normal state allowed. Subsequent changes in electrical activity were observed and the effects of the drugs evaluated. In the control group, no recovery of electrical activity was seen, but in the animals treated with either mannitol or FC, incomplete, yet distinct recovery was apparent. In the animals administered mannitol together with FC, however, marked recovery was evident. These experimental results indicate that the combined administration of mannitol and FC is effective in protecting the brain from cerebral ischaemia.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0942-0940
    Keywords: Cerebral infarction ; brain swelling ; mannitol ; glycerol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using our previously published “incomplete cerebral hemispheric infarction model in dogs” (produced by simultaneous ipsilateral occlusions of the anterior cerebral artery at the branching of the ethmoidal artery from its A1 portion, the A2 portion, the internal carotid artery, the posterior communicating artery, the posterior cerebral artery, and the anterior cerebellar artery), two, four, or six hours occlusion of blood flow was undertaken. Observations were then made on the degree of brain swelling following recirculation due to administration of mannitol or glycerol solutions. Furthermore, the leakage of Evans blue was investigated to determine the damage to the blood brain barrier. 1. In the animals given mannitol or glycerol, brain swelling was suppressed, following two hours occlusion. In the animals given mannitol, however, brain swelling was not suppressed after four or six hours occlusion. 2. After two hours occlusion in the animals given mannitol, leakage of Evans blue was slight compared with the untreated group. In the six hours occlusion groups, severe leakage of Evans blue was seen in both the untreated animals and the mannitol-treated animals. After two hours occlusion, in some animals which had been given glycerol, severe leakage of Evans blue was seen, even when there was little brain swelling.
    Type of Medium: Electronic Resource
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