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Biomedical subjects

J Ransohoff

Publications and source records attributed to J Ransohoff.

At least 127 records · Page 7Linked to original sources
PubMed1977

Ethanol potentiation of central nervous system trauma.

Two models have been used to study the effects of ethanol on injuries of the central nervous system. The spinal cords of cats were injured by delivering a 200 gm-cm impact to the exposed dura mater. A second group of animals received a similar injury to the exposed dura mater overlying the cerebral hemispheres. The animals were divided into two groups, those that received an infusion of ethanol before injury, and control animals that received no ethanol. The parameters of injury used in this model produced small and insignificant lesions in those animals that received no ethanol; however, when the animals were pretreated with ethanol, a considerable increase in the extent of the injury was noted. These include alterations in membranes-bound enzymes and clotting mechanisms, and alteration of cell membranes through abnormal free radical reactions.

Animals↗
PubMed1977

Cerebrospinal fluid sterols in the evaluation of patients with gliomas.

This study was an effort to obtain a marker indicative of the biologic activity of human gliomas. Sterol levels in the cerebrospinal fluid (CSF) were evaluated. Studies were conducted longitudinally during the course of tumor therapy. The evidence indicated that desmosterol levels in the CSF may reflect the growth potential of these neoplasms.

Adult↗
PubMed1977

Surgical management of malignant brain tumors.

Data are presented to support the contention that aggressive surgical management of malignant brain tumors, both primary and metastatic, is valuable in terms of quality and length of survival. Metastatic brain tumors must be solitary in a patient whose primary is either asymptomatic or under good control to justify surgical removal. Primary malignant gliomas are surgical candidates when the core of tumor can be excised, thus increasing survival after radiation and chemotherapy.

Brain Neoplasms↗
PubMed1977

Effect of levamisole on malignant experimental neurinoma grown subcutaneously in a young rat: brief communication.

Levamisole, a drug that stimulates the immunologic defenses of the host, was tested on the experimental malignant neurinoma grown subcutaneously in young female inbred CDF rats in a 3-month trial. The drug resulted in prevention of tumor growth in 80% of the treated animals, whereas tumors grew in 100% of the controls. After discontinuation of the drug, none of the animals in the treated group showed evidence of tumor growth upon clinical and pathologic examination 1 month after drug treatment was terminated. Treated animals failed to show any side effects related to levamisole upon clinical and pathologic examination.

Animals↗
PubMed1976

Desmosterol in human and experimental brain tumors in tissue culture.

Desmosterol, a possible chemical indicator of brain tumors, was detected in cells of neurogenic, nitrosourea-induced rat tumors (neurinomas and gliomas, C6 cell line) and in human astrocytomas grown in lipid-poor media. A further increase in the amount of cell desmosterol was obtained when triparanol was added to media containing delipidized serum. Cholesterol was replaced almost completely by desmosterol in tumor cells grown in media containing nontoxic levels of 20,25-diazacholesterol. Desmosterol did not accumulate when these inhibitors of desmosterol-reductase were added to culture media containing cholesterol and other lipids (whole fetal calf serum). The results demonstrate that tumors of the nervous system grown in tissue culture are capable of sterol synthesis, and indicate that a central mechanism of cholesterol synthesis is operative in these cells, which may be related to the availability of exogenous cholesterol. It is concluded that these findings are relevant to clinical studies on the use of cholesterol inhibitors as tools for the detection of brain tumor activity.

Animals↗
PubMed1976

Myelomeningocele: a progressive intra-uterine disease.

A series of cats were made hydrocephalic by intracisternal injection of kaolin, and four weeks later ventriculography confirmed the presence of hydromyelia. Ten days later, laminectomy in the lower thoracic region was performed. Several days later ventriculography revealed a markedly dilated central canal beneath the entire laminectomy, and pathological examination confirmed the presence of a focal bulge confined to the same region. On sectioning, it was evident that the central canal was massively enlarged to fill the entire spinal cord beneath the bulging region. The conclusion from these findings is that myelomeningocele is the result of progressive intra-uterine disease which begins with pathological hydromyelia and culminates in rupture of the unsupported spinal cord as a result of maldevelopment of associated dermal tissue.

Animals↗
PubMed1976

Role of computerized axial tomography in diagnosis and treatment of common neurosurgical problems of infancy and childhood.

Computerized axial tomography (CAT) is a new, highly accurate technique for studying the skull and intracranial contents. It is rapid enough to be utilized in acute emergencies and safe enough to be utilized for routine serial followups and evaluation of outpatients with equivocal findings. Because CAT can delineate the ventricular system without need for contrast agent, can distinguish clearly between hematoma and edema and can differentiate cystic from solid tumors, it finds wide application in the evaluation of neurological disease.

Brain Diseases↗
PubMed1976

Experimental alterations in cyclic adenosine monophosphate concentrations in the cat basilar artery.

Levels of cyclic adenosine monophosphate (AMP) in the basilar artery and in circulating blood of cats were determined after the production of spasm by topical application of blood to the vessel and following treatment with agents known to alter cyclic AMP. Isoproterenol, known to stimulate adenyl cyclase, and aminophylline, a phosphodiesterase inhibitor, were studied alone and in combination. Cyclic AMP of the basilar artery fell from a mean control value of 43 to 26 pmoles per milligram of protein following the production of vasospasm. Intravenous administration of isoproterenol alone and in combination with aminophylline produced dilatation of the basilar artery, which was associated with a marked rise in the cyclic AMP concentration in the vessel. The finding that cerebral vasospasm is associated with a fall and vasodilation with a rise in cyclic AMP concentration supports the hypothesis of an active role for cyclic nucleotides in the regulation of cerebrovascular smooth muscle tone.

Aminophylline↗
PubMed1976

Evaluation of mithramycin in the treatment of anaplastic gliomas.

A controlled, prospective, randomized study evaluated the use of mithramycin in the treatment of anaplastic glioma compared to a similar group of patients receiving best conventional care. From a total of 116 patients in the study, 96 were within the valid study group. All patients were operated on, had histological confirmation of anaplastic glioma, and received radiotherapy at the discretion of the principal investigator. Fifty-two patients received mithramycin at a dose of 25 mug/kg/day for 21 days, while 44 patients were in the control group. There was no significant difference in the median survival from time of randomization in those receiving mithramycin (21 weeks) as compared to those not receiving mithramycin (26 weeks). There was no significant difference between the two groups in relation to age distribution, sex, location, diagnosis, tumor characteristics, signs or symptoms, or radiotherapy received. Duration of symptoms correlates positively with survival and was also significantly longer in the control group than in the treated group. This, however, did not account for the failure of mithramycin to be found an effective agent. Although the study was not designed to evaluate the efficacy of radiotherapy, patients who were so treated had a significant improvement in survival. The toxic complications of mithramycin included gastrointestinal symptoms, dermatological involvement, anemia, and liver dysfunction, indicating the need for close supervision.

Adult↗
PubMed1976

Clinical and pathological study of 24 cases of gliosarcoma.

The authors review the clinical and pathological features of 24 patients with gliosarcoma. The study revealed the following findings. Gliosarcoma occurs more frequently than is indicated in the literature, and in our series was present in 8% of all cases of glioblastoma multiforme. The presenting features are not significantly different from those of glioblastoma multiforme. The lesion often presents itself at surgery as a firm, well circumscribed mass within the temporal lobe, and at surgery it is commonly mistaken for a meningioma. There is an increased likelihood of metastasis compared to that of glioblastoma. The prognosis is no worse than that of glioblastoma, in spite of the addition of sarcomatous elements.

Adult↗
PubMed1976

Hemicraniectomy in the treatment of acute subdural hematoma: a re-appraisal.

Although acute subdural hematoma continues to be one of the more common conditions neurosurgeons are called upon to treat, mortality rates continue to be quite unsatisfactory. Hemicraniectomy with wide decompression of the swollen brain was devised for the condition in 1971 (JNS 34:70-76). Initial results were quite encouraging with a 40% overall survival rate, 28% of the patients returning to normal activity. Since this original report, an additional 50 patients have been treated with only a 10% total survival rate and a 4% functional survival rate. Retrospective analysis of our cases over the past three years reveals that patient's age, status of preoperative neurologic examination, angiographic findings and appearance of the brain at operation, all have no statistical correlation with survival. These statistics will be presented and discussed. The failure of hemicraniectomy and extensive clot removal to significantly increase the functional survival rate in this condition implies that in a majority of patients with "acute subdural hematoma," primary brain stem and possibly subcortical injury are present, neither of which is amenable to radical therapy. The operation of hemicraniectomy should be restricted to those patients who enter hospital, obtunded but without demonstrable brain stem dysfunctionn, only to deteriorate subsequently because of increasing hemispheric edema and/or subdural clot.

Acute Disease↗
PubMed1976

Treatment of cerebral vasospasm by control of cyclic adenosine monophosphate.

Twelve patients with cerebral vasospasm following subarachnoid hemorrhage were treated with intravenous aminophylline and isoproterenol. After angiographic demonstration of spasm, all patients were begun on a continuous intravenous infusion of isoproterenol, 125 mug/hr, and aminophylline, 125 mg/hr, for a period of up to two weeks. The infusion was continued until there was clinical or angiographic evidence that spasm had diminished. Nine patients improved on this regimen and three remained unchanged. The use of isoproterenol and aminophylline is based on their effect on the enzymes responsible for the formation and degradation of cyclic adenosine monophosphate (cyclic AMP). An increase in cyclic AMP has been noted to produce relaxation of vascular smooth muscle. It is proposed that manipulation of these biochemical pathways may provide a method for influencing blood flow through cerebral vessels.

Adult↗