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At least 181 records · Page 10Linked to original sources
PubMed1993

Spread of blood in cerebrospinal fluid following craniotomy simulates spinal metastases.

Postoperative myelography with water-soluble contrast media was performed in 36 children with a diagnosis of posterior cranial fossa tumour. The myelograms were normal in 15. In 5 an intramedullary tumour was present and 3 of these had in addition subarachnoid changes as evidence of tumour spread. The remaining 16 patient had subarachnoid changes of a different character, mainly located in the posterior thoracic region and similar to those seen after subarachnoid haemorrhage. It is suggested that they represent adhesions caused by blood from the operation. The blood is assumed to be distributed by the large cerebrospinal fluid pulsations to the cervical and thoracic regions. It is important to recognise and differentiate subarachnoid changes due to tumour and to postoperative adhesions to avoid unnecessary radiotherapy to the spinal cord.

Blood Loss, Surgical↗
PubMed1994

Cytotoxicity of taxol in vitro against human and rat malignant brain tumors.

Taxol is a novel antitumor alkaloid that has shown clinical activity against several tumors, including ovarian and breast carcinoma and melanoma. To evaluate taxol's potential as a therapy for malignant brain tumors, we measured the sensitivity of four human (U87, U373, H80, and D324) and two rat (9L, F98) brain-tumor cell lines to taxol. The cells were exposed to taxol in vitro using a clonogenic assay. Log cell kill (LD90) occurred at concentrations of 42 (9L), 25 (F98), 19 (H80), 7.2 (U373), 9.1 (U87), and 3.9 nM (D324) when cells were continuously exposed to taxol for 6-8 days. The human cell lines were uniformly more sensitive to taxol than were the rat lines. The duration of exposure had a significant effect on taxol's cytotoxicity. When cells were exposed to taxol for 1 h the LD90 increased to 890 nM for the 9L rat line and 280 nM for the human U373 line. On the basis of these results, we conclude that taxol has significant potency in vitro against malignant brain tumors and that the activity occurs at concentrations of taxol that have previously been shown to be effective for several tumors against which the drug is currently being evaluated clinically.

Animals↗
PubMed1987

Erythropoietin in capillary hemangioblastoma. An immunohistochemical study.

Capillary hemangioblastoma is a tumor known to be associated with secondary polycythemia. Therefore, specimens from ten hemangioblastomas were studied by immunohistochemistry for the presence of erythropoietin, renin substrate, and for various endothelial, histiocytic and glial markers. In all tumors scattered cells among the stromal cells showed a positive-staining reaction with both anti-erythropoietin and anti-renin substrate. The same cells also stained positively for alpha-1-anti-trypsin. It is concluded that, in addition to the capillary endothelial cells, pericytes and stromal cells, capillary hemangioblastomas harbor cells containing and perhaps producing renin substrate and/or erythropoietin or a substance with similar antigenic determinants.

Angiotensinogen↗
PubMed1981

Glial fibrillary acidic protein in stromal cells of some capillary hemangioblastomas: significance and possible implications of an immunoperoxidase study.

Thirty-nine hemangioblastomas from 26 patients were studied by the immunoperoxidase method for GFA protein. Reactive gliosis in the form of trapped GFA protein-positive astrocytes or astrocytic cell processes penetrated the margins of all the neuraxial tumors and none of those occurring on nerve roots or in the tumor explants maintained in an organ culture system. Gliosis was especially prominent in tumors recurring after surgical excision or in patients with a long history of tumor. In six tumors, representing both the reticular and the cellular variants of hemangioblastoma, GFA protein-positive stromal cells were also found, chiefly in the periphery of the neoplasma: all these tumors were surrounded by dense reactive gliosis. Four hypotheses accounting for the presence of GFA protein-positive stromal cells are considered: (1) The tumors are astrocytomas. (2) The GFA protein-positive cells are not neoplastic but lipidized or altered reactive astrocytes. (3) The tumors are mixed and partly composed of neoplastic astrocytes. (4) The stromal cells are capable of taking up extracellular GFA protein derived from the adjacent reactive astrocytes. The last of these hypotheses is the most consistent with the collective evidence derived from the histological findings. It implies that the presence of GFA protein in the cytoplasm of a cell does not necessarily establish that the cell is glial. The possibility of uptake of GFA protein by non-glial cells must be considered if dense gliosis is present in the vicinity.

Adolescent↗
PubMed1984

Immunohistochemical study of fibronectin in hemangioblastomas and hemangiopericytomas.

Eight hemangioblastomas and two hemangiopericytomas were studied using indirect immunoperoxidase stains for fibronectin (FN) and glial fibrillary acidic protein (GFAP) in formalin-fixed, paraffin-embedded surgical specimens. Stromal cells in hemangioblastomas were GFAP-negative and showed variable FN expression, while GFAP-positive cells were FN-negative, thus suggesting that the stromal cells are not derived from astrocytes. Hemangiopericytoma cells were poorly to intermediately FN-positive. The origin of stromal cells is discussed in the light of their fine structure and the immunohistochemical stains with other cell markers.

Brain Neoplasms↗
PubMed1981

Do Rosenthal fibers contain glial fibrillary acid protein?

Sixteen cases of pilocytic astrocytomas with excessive Rosenthal fiber (RF) formation were examined by the indirect immunoperoxidase method for the localization of glial fibrillary acid protein (GFAP). RF never contained GFAP but they were often enclosed in plump and thickened GFAP-positive astrocytic processes. The border between the negative RF and the surrounding positive rim of cytoplasm was always sharp and without gradual transitions. The antigenic difference between RFs and glial filaments imply that glial filaments undergo a profound change in their chemical composition during their transformation into RFs. The possibility that RFs are not degradation products of glial filaments but consist of some chemically unknown substance produced by metabolically activated astrocytes cannot be excluded.

Astrocytes↗
PubMed1995

Response of brain tumors to chemotherapy, evaluated in a clinically relevant xenograft model.

Chemotherapy for brain tumors remains unsatisfactory. Despite increasing participation in clinical trials, there is a clear need for pre-clinical models. Heterotransplantation of surgical specimens directly into the anterior chamber of the nude mouse eye has been demonstrated to produce evaluable xenografts. Drug access in this model is considered to mimic the blood-brain barrier. Five clinical specimens in 3 children with primitive neuroectodermal tumor/medulloblastoma were the sources of 293 intraocular xenografts (5 cohorts by source). Each tumor-bearing mouse received 1 of 5 drugs or normal saline, by intraperitoneal injection, weekly for 5 weeks. Response was monitored for up to 22 weeks, using a staging system which estimates the proportion of the anterior chamber filled by tumor. Results were analysed both as response rates (shrinkage in excess of 50%) at the conclusion of the treatment course and as time to tumor progression by the life table method. Comparison of response rates within cohorts by source of xenografts (exact chi-square test for overall and 2-sided Fisher's exact test for paired comparisons) indicated cyclophosphamide to be the most effective single agent. In logrank analyses cyclophosphamide achieved significantly longer delays to progression than all other drugs in one cohort and longer delays than all but diaziquone in 2 other cohorts. The intraocular xenograft model is a clinically relevant system for the study of therapeutic agents in brain tumors. The effectiveness of intensive dosage cyclophosphamide in a model dependent on access across the blood-aqueous barrier is important and consistent with recent clinical data.

Animals↗
PubMed1996

Radiation-induced meningioma in children: report of two cases and review of the literature.

Meningioma developed in two children who had received high-dose cranial radiation for malignant brain tumors. Meningioma as a radiation-induced neoplasm has received little notice in the radiologic literature. Thirty-three cases have been reported since 1953, primarily in the neurosurgical literature. The current cases differ from those previously reported in having a much shorter latency period between irradiation and the development of meningioma.

Brain↗
PubMed1992

CSF drainage in patients with posterior fossa tumours.

The management of hydrocephalus secondary to a posterior fossa tumour is controversial. We audited recent practice with a retrospective analysis of 287 consecutive patients undergoing posterior fossa exploration for tumour. 85 shunts and 112 external ventricular drains (EVD) were placed. The overall CNS infection rate in the series was 6%. There was a significantly higher (p less than 0.01) infection rate in patients who had a drainage procedure, and a trend towards higher infection rates in patients with two drainage procedures. Early infection rates with EVDs and shunts were the same (7%). One third of patients with hydrocephalus had pre-operative drainage, a third had per-operative drainage but only a quarter required a permanent shunt. The majority of patients will not require a permanent shunt and where temporary CSF diversion is required EVD is reasonable.

Adolescent↗
PubMed1986

Further experience with ultrasound examinations in the postoperative brain.

Ultrasound examinations (US) of the brain are possible in the presence of an acoustic window in the skull, either after craniotomy or through an open fontanelle. In this study 19 children were examined, 11 via a suboccipital craniectomy; 9 cases were examined more than once. Via this suboccipital route most of the contents of the posterior fossa, the third and lateral ventricles could be made visible. In two patients with a temporal or parietal craniotomy the involved hemisphere could be visualized. Six patients were examined via the open fontanelle after insertion of a ventriculoperitoneal shunt (VPS). In three of these cases the examination was undertaken to evaluate also a posterior fossa cyst. The findings were compared with CT if the findings were equivocal.

Adolescent↗
PubMed1987

Cavernomas of the central nervous system: clinical syndromes, CT scan diagnosis, and prognosis after surgical treatment in 25 cases.

We present our clinical experience and the results of surgical management with 25 cavernomas of the CNS, treated in our hospital in the last 10 years. The location of the lesion assessed by clinical and CT scan examinations, proved to be the most significative factor determining the prognosis of cavernomas of the CNS, after surgical removal. The symptoms started in most of the cases in the third decade of life. 19 cases were located in the cerebral hemispheres and produced three well defined clinical syndromes: Irritative syndrome (seizures) present in 70% of the cases. Space-occupying lesion syndrome (20%) and haemorrhagic syndrome (10%). The remaining six cases were located within the basal ganglia, brainstem, pineal region, cerebellum and spinal cord, showing a progressive course. CT scan studies were performed on 24 cases. The characteristic image of a cavernoma is represented by a moderately hyperdense nodule with discreet contrast uptake. Calcification was observed in and around the lesions in 33% of the cases. Perilesional hypodensities suggestive of brain tissue atrophy were noted in 22% of the CT scans. On the other hand, 12% of cerebral hemisphere cavernomas showed atypical CT scan images that suggested an erroneous diagnosis of cystic gliomas. Radical surgical removal was performed in all cases. The postoperative results varied according to the location of the lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Serum immunoglobulins in brain tumours.

Immunoglobulin level in the sera of 62 patients with intracranial space occupying lesions was assayed using the radial immunodiffusion method. Serum IgM levels showed a highly significant increase in all types of brain tumour when compared to controls. Serum IgG levels were also increased in benign as well as malignant cases. Serum IgA levels were high only in benign cases. Hence, increased serum Ig levels may be of prognostic value in these cases.

Adolescent↗