Metastasis from the brain of transplanted N-ethyl-N-nitrosourea-induced central nervous system tumors in rats.
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Biomedical subjects
Publications and source records attributed to C J Vecht.
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Methods for assessing early characteristics and late outcome after severe head injury have been devised and applied to 700 cases in three countries (Scotland, Netherlands, and USA). There was a close similarity between the initial features of patients in the three series; in spite of differences on organisation of care and in details of management , the mortality was exactly the same in each country. This data bank of cases (which is still being enlarged) can be used for predicting outcome in new cases, and for setting up trials of management.
In head injured patients changes were found in the CSF levels of metabolites of the dopaminergic and the serotonergic neurotransmission (HVA and 5-HIAA). After the fifth day following trauma a significant decrease of the HVA levels in the lumbar CSF after probenecid treatment was found. The intensity of this decrease was found to be related to the severity of the trauma (period of unconsciousness), but not to the state of consciousness. Also the probenecid-induced 5-HIAA levels in conscious patients were decreased after the fifth post-traumatic day. In unconscious patients, the period of unconsciousness, particularly in the period of 5-20 days after trauma. Between 21 and 60 days after trauma the 5-HIAA concentrations in unconscious patients decreased remarkably, but they were still significantly higher than in the conscious patients. It can be concluded that during unconsciousness serotonergic neurons have a high rate of turnover, but that both neurotransmitter systems are damaged by the direct or indirect consequences of the injury.
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Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured in the lumbar cerebrospinal fluid of 98 patients after closed head injury. The HVA levels decreased in patients, whether or not they were given the drug probenecid, which inhibits the active transport of these acids from the brain. The decline of HVA was more notable in patients with the longest duration of unconsciousness. The HVA levels showed no correlation with the state of consciousness at the moment of the lumbar puncture. The 5-HIAA levels were below normal in the conscious patients, but paradoxically, at about normal levels in unconscious patients. The overall results suggest a decreased cerebral dopamine and serotonin metabolism after head injury.
ADP-induced platelet aggregation was studied for up to six weeks in 34 patients with head injuries. The patients were divided into three groups according to the degree of impaired consciousness assessed by a clinical coma scale, and change in platelet aggregation was related to the coma score. Platelet aggregation was markedly reduced in all eight patients dying within 24 hours of injury. All 17 patients who remained unconscious for four days or more showed decreased platelet aggregation up to nine days after admission, the most marked effect being on the second day. Platelet function in this group returned to normal within 16 days. Nine patients with only slightly impaired consciousness also showed subnormal platelet aggregation during the first few days with a return to normal by the fourth day. Platelet counts remained within normal limits in all groups. We suggest that during coma following head injury brainstem dysfunction induces neurohumoral changes in the blood which are responsible for a decrease in platelet function.
Blood coagulation tests were performed on admission to the hospital and on consecutive days after severe and moderate head injury in 34 patients. Platelet counts and fibrinogen were normal at admission and raised thereafter. The partial thromboplastin time was shortened at admission and lengthened in the following days. Fibrinolytic activity was enhanced at admission. The ethanol gelation test was negative in all patients during the post-traumatic time course. It was concluded that, in the first 24 hours after injury, activated coagulation was present after head injury. In contrast with data of other authors, disseminated intravascular coagulation did not occur in these series.
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In the last few years it has been shown that anaplastic oligodendrogliomas, in contrast to anaplastic astrocytomas, are responsive to a three drug regimen chemotherapy. The histologic criteria for the discrimination between oligodendrogliomas and astrocytomas are subject to substantial interobserver variability, particularly in anaplastic and mixed gliomas. In the present study a two-dimensional electrophoresis technique (2-DE) has been applied to glioma samples in an attempt to discriminate the glioma subtypes. It was found that the presence of glial fibrillary acidic protein (GFAP) fragments distinguishes oligodendroglioma from astrocytoma. One-dimensional (1-DE) immunoblots were compared with immunohistologically stained tissue sections in which various GFAP-positive cell types were seen. It is concluded that 2-DE and 1-DE GFAP immunoblotting provide accurate information for the reliable discrimination of anaplastic astrocytomas and oligodendrogliomas.