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41.
Abstract We report a patient with repeated venous infarcts in the occipital lobe and occlusion of the superior vena cava. The pathogenetic relationships between the superior vena cava occlusion and the brain infarcts are discussed. High pressure in the superior venous territory and incomplete patency of the transverse sinus are probably responsible for the venous infarcts. Received: 12 July 1996 Accepted: 27 August 1996  相似文献   
42.
The authors present their first experience with laser interstitial thermotherapy, (ITT). Four patients with deep-seated non-infiltrative benign tumours (three astrocytomas, one oligodendrocytoma) underwent ITT. Previously, a stereotactic procedure had been performed to determine the exact location of the tumour, its spatial configuration and its histological diagnosis. The MRI controls confirmed the efficacy of hyperthermia on the tumour tissues. The authors discuss the possible ITT mechanisms. The indications of such laser ITT in neurosurgery should be enlarged to malignant tumours (gliomas, metastases) and to certain hypophyseal adenomas.  相似文献   
43.
L-2-Hydroxyglutaric acid (LGA) is the biochemical hallmark of patients affected by the neurometabolic disorder known as L-2-hydroxyglutaric aciduria (LHGA). Although this disorder is predominantly characterized by severe neurological findings and pronounced cerebellum atrophy, the neurotoxic mechanisms of brain injury are virtually unknown. In the present study, we investigated the effect of LGA, at 0.25-5mM concentrations, on total creatine kinase (tCK) activity from cerebellum, cerebral cortex, cardiac muscle and skeletal muscle homogenates of 30-day-old Wistar rats. CK activity was measured also in the cytosolic (Cy-CK) and mitochondrial (Mi-CK) fractions from cerebellum. We verified that tCK activity was significantly inhibited by LGA in the cerebellum, but not in cerebral cortex, cardiac muscle and skeletal muscle. Furthermore, CK activity from the mitochondrial fraction was inhibited by LGA, whereas that from the cytosolic fraction of cerebellum was not affected by the acid. Kinetic studies revealed that the inhibitory effect of LGA on Mi-CK was non-competitive in relation to phosphocreatine. Finally, we verified that the inhibitory effect of LGA on tCK was fully prevented by pre-incubation of the homogenates with reduced glutathione (GSH), suggesting that this inhibition is possibly mediated by oxidation of essential thiol groups of the enzyme. Considering the importance of creatine kinase activity for energy homeostasis, our results suggest that the selective inhibition of this enzyme activity by increased levels of LGA could be possibly related to the cerebellar degeneration characteristically found in patients affected by L-2-hydroxyglutaric aciduria.  相似文献   
44.
We performed 3-dimensional studies of vascular casts of the microvasculature of the cerebral cortex of rats that were exposed to three weeks of hypobaric hypoxia and of control rats. Scanning electron microscopy of the casts gave the qualitative impression of increased vascularity of the cerebral cortex, particularly the deeper layers, in hypoxic rats. Quantitative analysis of capillary segment lengths revealed a significant shift in the frequency distribution to longer lengths (from 77 ± 8 to 90 ± 14 μm) in the deep, but not in the superficial, layers of the cerebral cortex of hypoxic rats. These findings agree with previous results reporting increased capillary density in the brain after exposure to prolonged hypobaric hypoxia and suggest that capillary segment elongation plays a role in the increased capillary density in the deeper layers of the cerebral cortex.  相似文献   
45.
Neuropathological findings in two siblings with familial erythrophagocytic lymphohistiocytosis (FEL) are reported. Case 1 showed the typical neuropathological findings of FEL with lymphohistiocytic infiltration of the leptomeninges and perivascular spaces. A characteristic erythrophagocytosis was detected in inguinal lymph nodes, lung and bone marrow. Case 2 revealed calcification and necrotic lesions in the brain. In the necrotic areas, parenchymal calcification, vascular medial calcification, and occlusion of many vessels due to subendothelial fibrosis were detected. The areas of necrosis correlated with the distribution of occluded vessels. These changes were most prominent in putamen, internal capsule, thalamus and dentate nucleus. Hypercytokinemia is suspected to be the underlying mechanism for the clinical and laboratory findings in patients with FEL, although the relationship to the vascular pathology is unclear.  相似文献   
46.
Whistling face syndrome or cranio-carpotarsal dysplasia is a very rare disorder that consists of a characteristics facies and digital abnormalities. Magnetic resonance imaging investigation of the brain in this syndrome has not been reported previously. This communication describes the brain malformations in an infant with the syndrome, which covered delayed myelination, thickened and infolded cortices (cortical dysplasia), dysplastic corpus callosum, and agenesis of the inferior vermis.  相似文献   
47.
In patients with hepatic cirrhosis, the globus pallidus and putamen show high intensity on T1-weighted MRI. While the causes of this high signal have been thought to include paramagnetic substances, especially manganese, no evidence for this has been presented. Autopsy in four cases of hepatic cirrhosis permitted measurement of metal concentrations in brain and histopathological examination. In three cases the globus pallidus showed high intensity on T1-weighted images. Mean manganese concentrations in globus pallidus, putamen and frontal white matter were 3.03 ± 0.38, 2.12 ± 0.37, and 1.38 ± 0.24 (μg/g wet weight), respectively, being approximately four- to almost ten-fold the normal values. Copper concentrations in globus pallidus and putamen were also high, 50 % more than normal. Calcium, iron, zinc and magnesium concentrations were all normal. The fourth case showed no abnormal intensity in the basal ganglia and brain metal concentrations were all normal. Histopathologically, cases with showing high signal remarkable atrophy, necrosis, and deciduation of nerve cells and proliferation of glial cells and microglia in globus pallidus. These findings were similar to those in chronic manganese poisoning. On T1-weighted images, copper deposition shows no abnormal intensity. It is therefore inferred that deposition of highly concentrations of manganese may caused high signal on T1-weighted images and nerve cell death in the globus pallidus. Received: 12 August 1996 Accepted: 17 December 1996  相似文献   
48.
Summary The case is presented of a patient showing multiple subcortical haemorrhages after lumbar metrizamide myelography. This complication after intrathecally administered metrizamide contrast medium appears not to have been reported before. Several different possible explanations are proposed for the phenomena observed in this case.  相似文献   
49.
Summary In various primary brain tumours of neuroepithelial tissue recombinant DNA techniques were used to demonstrate changes of the epidermal growth factor receptor gene, which is homologous to the c-erbB oncogene. Twenty-one of 40 grade III/IV tumours, but only 1 of 16 grade I/II tumours were found to contain amplified and/or rearranged c-erbB sequences. This highly significant difference suggest that c-erbB amplification, rearrangement, or both, are important steps in malignant transformation in a subset of patients with neuroepithelial tumours.  相似文献   
50.
Thirty-five posters were presented at the Workshop on Brain Uptake And Utilization Of Fatty Acids, Lipids, and Lipoproteins. They were grouped into four categories: (1) mechanisms of lipid uptake and transport to the brain, (2) lipoproteins and polyunsaturated fatty acids, (3) eicosanoids in brain function, and (4) fatty acids and lipids in brain disorders. This article summarizes the highlights of the research presented in these posters. The individual abstracts follow these synopses.  相似文献   
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