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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ultrastructure of the blood vessels of primary central nervous system malignant lymphoma was studied and compared with those in glial, non-glial and metastatic brain tumors. Five surgical specimens were studied by conventional ultrathin section and freeze-fracture replica techniques. Tumor vessels of various sizes were found. The luminal surfaces of the tumor vessels were irregular and the basal lamina had multiple-layer structure. The perivascular spaces were enlarged and infiltrated with tumor cells. The endothelium had marked infoldings, increased pinocytotic vesicles and fenestrations. The intercellular junctions were short but no obvious opening was seen. On the replica specimen pinocytotic vesicles were calculated on an average of 28 per microns2. The essential features of the blood vessels in primary central nervous system malignant lymphoma were the fenestrated vessels. They resembled the blood vessels found in non-glial and metastatic brain tumors, but were distinctly different from those seen in glial tumors with non-fenestrated vessels.
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PMID:[Ultrastructure of capillary permeability in malignant lymphoma]. 261 97

In this paper we present the results of post-mortem examinations of the central nervous system in 61 male patients who died with Acquired Immunodeficiency Syndrome (AIDS); it includes 23 patients with reported neurological abnormalities at the time of presentation. The analysis revealed central nervous system (CNS) neoplasms (lymphoma, Kaposi's sarcoma) and a variety of inflammatory lesions (bacterial, fungal, protozoal and viral) in 32 cases. A total of 11 patients without opportunistic infections showed significant brain abnormalities characterized by microglial nodules and/or multinucleated giant cells, changes which are probably related to infection by human immunodeficiency virus (HIV). In addition, we describes results from a series of experiments designed to define the target cell population of HIV in the brain. The expression of CD4 complex--putative receptor for HIV--was investigated using short-term cultured brain cells taken from embryonic brain anlage and from different regions of fetal brain; glioma cells were also used. Cells derived from normal embryonic and fetal brain, as well as glioma cells, were examined with respect to their susceptibility to HIV. CD4 antigen expression could be demonstrated only on glioma cells of the permanent glioma line 85HG-59 comprised of cells with properties characteristic of astrocytes. Nevertheless, normal embryonic and fetal brain cells as well as glioma cells could be infected by HIV as documented by immunocytochemical methods and southern blot analysis. HIV infected brain cells showed reduced growth rate and altered growth pattern. This study emphasizes the diversity of HIV conditioned CNS impairments, suggesting that genomic variability of HIV may result in varying cell type preference of the virus. The experimental data indicate that CD4 expression in brain cells is probably not 'conditio sine qua non' for HIV susceptibility. The alterations of HIV-infected brain cells demonstrated provide further evidence for a direct involvement of HIV in the pathogenesis of AIDS-related neurological syndromes.
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PMID:Evaluation of intracerebral lesions in patients with acquired immunodeficiency syndrome. Neuropathological findings and experimental data. 274 42

With the aim of finding characteristics pointing to the primary site, computed tomography examination from 9 patients with primary brain malignant lymphoma (non-Hodgkin's lymphoma originating in the central nervous system, NHL-CNS) (5 single, 4 multiple lesions) were analyzed. The tumors were usually situated in the basal ganglia, corpus callosum, or cerebellum and were always in contact with either the ependyma of the ventricles or the subarachnoid space. Tumors with widespread infiltration of white matter surrounding the ventricles were characteristic of NHL-CNS. Microscopic examination of 3 autopsy cases revealed infiltration of the subependymal layer of the lateral ventricles and the third and fourth ventricles by lymphoma cells. The entire extent of the choroid plexus was invaded by tumor cells. There were multiple foci of similar cells invading the periventricular white matter. The subarachnoid space was filled with lymphoma cells. In many areas the Virchow-Robin spaces and pial-glial membranes were disrupted, and invasion of the underlying gray matter by tumor cells was seen. The ultrastructure of the blood vessels of NHL-CNS was compared with those in glial, nonglial, and metastatic brain tumors. The essential feature in NHL-CNS was fenestrated vessels. They resembled the blood vessels found in nonglial and metastatic brain tumors, but were distinctly different from those seen in glial tumors with nonfenestrated vessels. Although the following scheme in proposed with reservations, it could account for the sites of origin of NHL-CNS: lymphocytes located in the choroid plexus stroma or the subarachnoid space are activated, caused to proliferate, and finally become neoplastic.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sites of origin of primary intracerebral malignant lymphoma. 275 72

1H image-guided 31P MR spectra of normal human brain and of intracranial tumors have been analyzed quantitatively. Tumor types examined include prolactinoma, lymphoma, and various grade gliomas. The experimental signals were processed by means of a time-domain least-square fitting procedure, which yields the spectral parameters, as well as a prediction of the standard deviations. Significant spectral variations are observed within both populations of normal brain and of intracranial tumor 31P MR spectra. The metabolic ratios derived from the glioma 31P MR spectra and from corresponding uninfiltrated brain tissue do not differ significantly. Significant differences are, however, observed between the metabolic ratios of prolactinoma and uninfiltrated tissue 31P MR spectra. Alkaline pH values are found for the prolactinoma and the high-grade gliomas. Furthermore, spectral differences are observed between the patient's uninfiltrated tissue 31P MR spectra and those of an unmatched population of volunteers. This underscores the necessity for control measurements on the uninfiltrated tissue of the patient and for controls from a matched population of healthy individuals.
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PMID:1H image-guided localized 31P MR spectroscopy of human brain: quantitative analysis of 31P MR spectra measured on volunteers and on intracranial tumor patients. 277 22

Opiate receptor-mediated inhibition of adenylate cyclase activity was elicited in membranes of C6BUI glioma cells and S49 cyc- lymphoma cells after fusion with opiate receptor-containing membranes derived from NG108-15 neuroblastoma x glioma hybrid cells. The fusion was induced by polyethylene glycol using procedures developed by Orly and Schramm [(1976) Proc. Natl. Acad. Sci. USA 73, 4410-4414]. Prior to fusion, the adenylate cyclase activity of the donor. NG108-15 cell membrane, was inactivated by N-ethylmaleimide treatment. Prostaglandin E1 receptors and the stimulatory GTP-binding protein Ns were transferred to the recipient cells along with opiate receptors. Thus, inhibitory receptors can be transferred to foreign adenylate cyclase systems just as stimulatory receptors had earlier been found to do. Furthermore, opiate receptors have been shown to function in non-neuronal cells.
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PMID:Transfer of functional opiate receptors from membranes to recipient cells by polyethylene glycol-induced fusion. 282 Aug 7

Hormonal regulation of Mg2+ influx was examined in the neuroblastoma X glioma hybrid cell line NG108-15 and the skeletal muscle cell line G8 using 28Mg2+. Both cell lines express multiple classes of hormone receptors; in addition, G8 cells can be induced to differentiate from a single myoblast-like cell into fused myotube-like cells. In NG108-15 cells, 2-Cl-adenosine, an adenosine receptor agonist, stimulated Mg2+ influx by about 60%. This effect was not mimicked by norepinephrine or PGE1, agonists at alpha 2-adrenergic and prostaglandin receptors which NG108-15 cells also express. Carbachol, acting through a muscarinic receptor, gave minimal and variable stimulation of Mg2+ influx. The effect of 2-Cl-adenosine was not blocked by theophylline, an adenosine receptor antagonist, and was not mimicked by adenosine analogs selective for either A1 or A2 adenosine receptors, suggesting that a nonclassical adenosine receptor mediates the effect on Mg2+ influx. Theophylline slightly stimulated Mg2+ influx as did the permeable cyclic AMP analog, 8-Br-cyclic AMP. These results indicate that cyclic AMP may influence Mg2+ influx in NG108-15 cells unlike previous results in murine S49 lymphoma cells [Maguire and Erdos, J. biol. Chem. 255: 1030-1035, 1980] where receptor modulation of Mg2+ influx was independent of cyclic AMP. In G8 cells, the nicotinic cholinergic receptor agonist carbachol stimulated Mg2+ influx at the myoblast cell stage but had no effect on Mg2+ influx after cells had formed myotubes. The beta-adrenergic agonist isoproterenol had the opposite effect, stimulating Mg2+ influx in the myotube stage but not in the myoblast stage. Taken together, these results demonstrate that only a subset of receptors expressed by a cell may be coupled to Mg2+ influx, that the regulation of Mg2+ influx differs from cell type to cell type, and finally, that modulation of Mg2+ influx by hormone receptors may change with differentiation.
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PMID:Hormonal regulation of magnesium uptake: differential coupling of membrane receptors to magnesium uptake. 282 11

The cellular mechanism of action of the cannabimimetic drugs is examined using cultured cells. In membranes from N18TG2 neuroblastoma cells and the neuroblastoma X glioma hybrid cells, NG108-15, the psychoactive cannabinoid drugs and their nantradol analogs could inhibit adenylate cyclase activity. This response was not observed in either the soluble adenylate cyclase from rat sperm or membrane-bound adenylate cyclases from C6 glioma or S49 lymphoma cells. This cellular selectivity provides further evidence for the existence of specific receptors for the cannabimimetic compounds. Receptor-mediated inhibition of adenylate cyclase requires the presence of a guanine nucleotide-binding protein complex, Gi. Gi can be functionally inactivated as a result of an ADP-ribosylation modification catalyzed by pertussis toxin. The present study demonstrates that pertussis toxin treatment of cells abolished the cannabimimetic response in intact cells and in membranes derived therefrom. The action of pertussis toxin required NAD+ as substrate for in vitro modification of neuroblastoma membranes. Furthermore, pertussis toxin was able to catalyze the labeling of a neuroblastoma membrane protein in vitro using [32P] NAD+ under conditions similar to those by which attenuation of the cannabimimetic inhibition of adenylate cyclase could be demonstrated. This evidence demonstrates the requirement for a functional Gi in the action of cannabimimetic drugs.
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PMID:Involvement of Gi in the inhibition of adenylate cyclase by cannabimimetic drugs. 286 5

The local use of radionuclides in the management of neoplastic processes was initially considered over 80 yr ago and has enjoyed increasing enthusiasm in the treatment of somatic and central nervous system tumours during the past 30 yr. The marriage of complex neuroimaging techniques and modern stereotactic devices has markedly enhanced the technical precision of interstitial radiobrachytherapy of malignant cerebral neoplasms. In applying these techniques, it is imperative to achieve an optimal placement of radionuclide sources in order to develop a geometrically homogenous, controlled distribution of radiation. Critical considerations include determination of tumour volume and contour, and development of a homogenous dose rate (dependent upon multiple sources at varying intensity) that will not only effect tumour cell kill but do this without excessive production of radionecrosis which necessitates craniotomy because of mass. Using the Brown-Roberts-Wells (BRW) stereotactic guidance system and an image-defined, volumetrically determined target, implants of multiple iridium 192(192Ir) sources were used to establish appropriate isodose envelopes. A methodology for achieving the described objectives is detailed as it applies to a variety of malignant intracerebral neoplasms (glioblastoma multiforme, malignant astrocytoma, malignant mixed glioma, primary cerebral lymphoma, metastatic carcinoma and malignant pineal region tumours). Technical realization of precision implantation relying upon imaging data may be acheived with this method with satisfactory responses that are dependent upon histological tumour type and the morphology of the tumour distribution as related to the image. Early and late complications related to the surgical technique and radionuclide applications were less than 5%. Although encouraging, these techniques require further definition and greater data accrual before uniform application outside major medical centres can be justified. It is anticipated that improvement in results with intrinsic gliomas and other invasive neoplasms will be realized with further definition of tumour boundaries by tract biopsy techniques and concurrent utilization of hyperthermia and brain protective methods.
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PMID:Interstitial radiobrachytherapy of malignant cerebral neoplasms: rationale, methodology, prospects. 288 48

Prion protein (PrP) forms the fibrils or prion rods isolated from scrapie-infected brain and has been proposed as the major component of the infectious agent of this slowly progressive spongiform encephalopathy. In previous Northern blot analyses PrP-specific mRNAs have been found in both normal and scrapie-infected brains but not in spleen, an organ which harbours large titres of infectivity. In the present study, mouse PrP DNA was used to probe for PrP mRNA in assorted tissues and cells. A reexamination of mouse and hamster spleens revealed that they contained low levels of PrP mRNA (approx. 0.8% of that in brain mRNA). No consistent differences were observed between normal and scrapie-infected tissues. Also positive for PrP mRNA under stringent hybridization conditions were mouse epithelial, neuroblastoma, erythroid, B-lymphocytic and embryo fibroblast tissue culture cell lines, a hamster ovary cell line, a rat glioma cell line, and human T lymphocytic and neuroblastoma cell lines. In contrast, no PrP mRNA was detected in two mouse myeloid cell lines and one T cell lymphoma. These results provide evidence that PrP is a protein common to numerous, but not all, cell types besides those of the brain.
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PMID:Detection of prion protein mRNA in normal and scrapie-infected tissues and cell lines. 289 63

Postoperative interventional neuroradiology was performed in patients with malignant gliomas to increase target efficacy of chemotherapy. In 8 glioma patients the blood brain or blood tumor barrier was reversibly opened by intraarterial injection of hyperosmolar fluid (Mannitol 25%). One additional patient had primary lymphoma of the central nervous system. During barrier modification chemotherapeutic agents were applied intraarterially and intravenously. A total of 22 blood brain barrier modification procedures have been carried out until now, ranging from one to five per patient. A presently continuing tumor regression or tumor progression free intervals have been noted in 5 patients. Therapeutic effects are being evaluated from repeated computed tomography and single photon emission computed tomography examinations.
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PMID:Blood brain barrier modification and chemotherapy. Interventional neuroradiology in the treatment of malignant gliomas. 298 Apr 57


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