Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experimentally induced brain glioma cell lines were studied in cell cultures for their fibrinolytic activity; simultaneously the mitotic index was determined. It was found that the most intense fibrinolytic activity of glioma cells coincides with mitotic waves. After 68 hr incubation of SD/G1 cells on a [125I]fibrin layer, [125I]fibrin digestion products were examined by gel chromatography. Hydroxy-urea and actinomycin D were used as inhibitors in cell cultures, investigating their effect on the expression of fibrinolysis. These studies reveal that [125I]fibrin digestion products are mainly low molecular weight (less than 12,000 daltons) compounds and that fibrinolysis is partially inhibited by the drugs added.
 ...
PMID:Fibrinolysis induced by rat glioma cells. A mitosis-triggered process? 56 67

Histopathological examinations were made on tumors of the nervous system induced in rats of Donryu strain by weekly intravenous injections with N-nitroso-methyl-urea (NMU) or by a single administration of NMU through the mothers. A total of 176 neural and nonneural neoplasms were produced in this study. It was suggested that the fetal nervous system of Donryu rats was also highly susceptible to the oncogenic effects of NMU. Of these tumors produced, those of the peripheral nervous system amounted to 121, comprising 68.7% of the total number of the neoplasm. Microscopically, most of the nerve tumors showed the histology corresponding to that of human neurinomas. Many tumors, however, disclosed more or less anaplastic cytological appearance. Fifteen gliomas were produced in the brain and spinal cord. Microscopically, they were classified into mixed glioma, oligondendroglioma and anaplastic astrocytoma. The commonest brain tumors produced in rats from intravenously treated group were periventricular mixed gliomas, while gliomas in rats from transplacentably treated group showed an isomorphic histology with a close resemblance to that of oligodendroglioma.
 ...
PMID:Histopathological studies of the nervous system tumors in rats induced by N-nitroso-methyl-urea. 118 45

Intrathecal administration of ACNU ((1-4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitroso urea hydrochloride) had a remarkable chemotherapeutic effect in a rat model of meningeal gliomatosis. This effect was evaluated in rats with meningeal gliomatosis induced by an intracisternal inoculation of rat C6 glioma cells. The median survival time of the rats treated with a single dose of intrathecal ACNU (1 mg/kg) on Day 1 or Day 3 after tumor inoculation was significantly prolonged by 35.7% to 42.9% or 25.0% to 28.6%, respectively, as compared with that of the control animals. Meningeal gliomatosis rat models treated intrathecally with ACNU (1 mg/kg) 5 days after tumor inoculation or intravenously with ACNU (15 mg/kg) both failed to prolong the survival time of the animals. These findings suggest that intrathecal chemotherapy with a low dose of ACNU is effective in the early stages of meningeal gliomatosis, whereas intravenous chemotherapy with a high dose of ACNU is always ineffective.
 ...
PMID:Intrathecal chemotherapy with ACNU in a meningeal gliomatosis rat model. 140 22

In membranes of neuroblastoma x glioma (NG108-15) hybrid cells, the photoreactive GTP analog, [alpha-32P] GTP azidoanilide, was incorporated into 39-41-kDa proteins comigrating in urea-containing sodium dodecyl sulfate-polyacrylamide gels with immunologically identified G-protein alpha-subunits, i.e. a 39-kDa Go alpha-subunit, a 40-kDa Gi2 alpha-subunit, and a 41-kDa Gi alpha-subunit of an unknown subtype. The synthetic opioid, D-Ala2,D-Leu5-enkephalin (DADLE), stimulated photolabeling of the 39-41-kDa proteins. In the presence of GDP, which increased the ratio of agonist-stimulated to basal photolabeling, DADLE at a maximally effective concentration stimulated photolabeling of the 39- and the 40-kDa protein 2-3-fold. Somatostatin, adrenaline, and bradykinin were less potent than DADLE and, to varying degrees, stimulated photolabeling of the 40-kDa protein more than that of the 39-kDa protein. Prostaglandin E1 was inactive. The present data represent direct evidence for an activation of endogenous Go and Gi2 via opioid receptors and other receptors in the native membrane milieu.
 ...
PMID:Evidence for opioid receptor-mediated activation of the G-proteins, Go and Gi2, in membranes of neuroblastoma x glioma (NG108-15) hybrid cells. 167 72

A novel tool in diagnostic and experimental pathology, the AgNOR-technique, which consists of visualization of ribosomal gene activity by selective silver staining, was applied to 144 cytological specimens of human tumours of the nervous system. The number of silver-stained nucleolar organizer regions (AgNORs) was correlated with the biological behaviour of the tumours investigated; low AgNOR number were observed in benign neoplasms such as meningiomas and schwannomas and higher AgNOR numbers in glioblastomas and metastases. The mean AgNOR number per cell was 3.15 in astrocytomas, 4.5 in anaplastic astrocytomas and 5.86 in glioblastoma multiforme. Benign and malignant lesions showed different distribution patterns of AgNORs, with few but centrally located AgNORs in benign, and multiple but scattered AgNORs in malignant tumours. AgNOR number per cell and AgNOR area revealed an inverse relationship (correlation coefficient -0.15, linear regression). In addition to the human tumours, two N-nitroso-N-ethyl-urea (NEU) induced tumors in BD-IX rats a mixed glioma (G-XIII) and a malignant schwannoma (N-XII), were investigated. Twelve G-XIII gliomas revealed homogenous AgNOR-counts (standard error of the mean less than 10%), with absolute values between the values obtained for human glioblastomas and metastases. Seven N-XIII subcutaneously transplanted schwannomas revealed higher AgNOR values than human schwannomas, but lower than experimental gliomas. It is concluded that the AgNOR method, as a technique for visualization of ribosomal gene activity, is valuable for assessing proliferative activity and malignancy in both diagnostic and experimental neuropathology.
 ...
PMID:Cell proliferation in intracranial tumours: selective silver staining of nucleolar organizer regions (AgNORs). Application to surgical and experimental neuro-oncology. 171 8

Three distinct antipeptide antisera generated against synthetic peptides that represent parts of the primary sequence of the alpha-subunit of the (pertussis toxin-sensitive) guanine nucleotide binding protein G0 were used in two-dimensional immunoblots of membranes of neuroblastoma X glioma (NG108-15) cells. Each antiserum identified two distinct polypeptides of some 39 kDa. These had apparent isoelectric points of 5.5 and 5.8. Differentiation of NG108-15 cells in response separately to dibutyryl cyclic AMP (cAMP), 8-bromo cAMP, forskolin, and prostaglandin E1 produced elevated levels of G0 alpha, as has previously been noted in one-dimensional immunoblots. Two-dimensional analysis demonstrated that the cAMP-induced increases in levels of G0 alpha were only of the more acidic isoform. The two isoforms were both substrates for pertussis toxin-catalysed ADP-ribosylation and did not appear to represent differentially phosphorylated forms of the same polypeptide. Separation of the two forms of G0 alpha could be achieved in one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis when 4 M deionized urea was included in the resolving gel. The more slowly migrating band was the acidic form and corresponded exactly in mobility with the major form of G0 from both rat and mouse brain. There was no equivalent in brain of the more rapidly migrating form of G0 from the cells. In agreement with the data from two-dimensional gels, only the more slowly migrating form was expressed in considerably higher amounts following cAMP-induced differentiation of NG108-15 cells. Of these two forms of "G0," the acidic species is equivalent to G0 from brain, but the basic form is not identical with G0*, which has been purified from bovine brain.
 ...
PMID:Identification of two distinct isoforms of the guanine nucleotide binding protein G0 in neuroblastoma X glioma hybrid cells: independent regulation during cyclic AMP-induced differentiation. 217 64

Tenascin/hexabrachion is a large glycoprotein of the extracellular matrix. Previous reports have demonstrated that tenascin is associated with epithelial-mesenchymal interfaces during embryogenesis and is prominent in the matrix of many tumors. However, the distribution of tenascin is more restricted in adult tissues. We have found tenascin to be present in normal human skin in a distribution distinct from other matrix proteins. Immunohistochemical studies showed staining of the papillary dermis immediately beneath the basal lamina. Examination of skin that had been split within the lamina lucida of the basement membrane suggested a localization of tenascin beneath the lamina lucida. In addition, there was finely localized staining within the walls of blood vessels and in the smooth muscle bundles of the arrectori pilorem. Very prominent staining was seen around the cuboidal cells that formed the basal layer of sweat gland ducts. The sweat glands themselves did not stain. The distribution of tenascin in the papillary dermis was studied at high resolution by immunoelectron microscopy. Staining was concentrated in small amorphous patches scattered amongst the collagen fibers beneath the basal lamina. These patches were not associated with cell structures, collagen, or elastic fibers. Tenascin could be partially extracted from the papillary dermis by urea, guanidine hydrochloride, or high pH solution. The extracted protein showed a 320-kD subunit similar to that purified from fibroblast or glioma cell cultures. We have developed a sensitive ELISA assay that can quantitate tenascin at concentrations as low as 5 ng/ml. Tests on extracts of the papillary dermis showed tenascin constituted about 0.02-0.05% of the protein extracted.
 ...
PMID:Tenascin/hexabrachion in human skin: biochemical identification and localization by light and electron microscopy. 247 9

Mechanism of methylmercury cytotoxicity was investigated with special reference to its preferential action on microtubules and protein biosynthesis in cultured cells. The tubulin synthesis analyzed by autoradiography of two-dimensional electropherogram using 35S-methionine was inhibited by 50-70% in mouse glioma cells exposed to 5 x 10(-6) M methylmercury for 3 h, which almost completely depolymerized microtubules. Total protein synthesis monitored by incorporation of labeled methionine into acid insoluble fraction was decreased slightly but significantly and the protein bands other than tubulin on gradient urea-PAGE gel appeared to remain unchanged under the experimental condition used. These results suggest that the inhibition of protein synthesis observed on exposure to methylmercury can be ascribed, at least partly, to a possible autoregulatory depression in tubulin synthesis owing to the increase in the pool of tubulin subunits resulted from microtubule depolymerization by methylmercury.
 ...
PMID:Mechanism of cytotoxicity of methylmercury. With special reference to microtubule disruption. 248 6

During 1983 and 1984, 240 newly diagnosed cases of brain glioma and 742 controls (465 non-glioma nervous system tumors and 277 patients with other neurologic diseases) were recruited and interviewed in the neurologic and neurosurgical departments of two hospitals in Milan, Italy. The occupational histories of cases and controls were compared, and relative risk estimates, adjusted for sex, age, residence, and socioeconomic status, were computed using the Mantel-Haenszel method. A statistically significant risk increase was found for farmers (relative risk (RR) = 1.6, p = 0.0025). This risk increase was attributable to those farmers who reported the use of chemicals (insecticides or fungicides, herbicides, and fertilizers). Among the three groups of investigated agrochemicals, only the use of insecticides or fungicides was associated with a significant increase in relative risk (RR = 2.0, p = 0.006). Many farmers exposed to fungicides reported the use of commercial compounds of copper sulfate. Some of these compounds contain methyl urea, which has a specific carcinogenic effect on the nervous system in animals. These data suggest that the occupational exposure of farmers to agrochemicals might be responsible for the observed excess risk of brain glioma in farmers.
 ...
PMID:A case-control study of brain gliomas and occupational exposure to chemical carcinogens: the risk to farmers. 342 Dec 43

We have studied the effect of butyrate and other short-chain fatty acids on thyroid hormone nuclear receptors in C6 cells, a rat glioma cell line. Exposure of C6 cells to butyrate leads to increased levels of L-triiodothyronine (T3) in the nuclear and extranuclear compartments. The rise in nuclear binding is not merely a reflection of the higher cellular hormone content, and Scatchard analysis of T3 binding to isolated nuclei reveals that butyrate increases receptor number without changing affinity. The effect on the receptor is quantitatively important: a 48-h incubation with 2 mM butyrate increases nuclear binding by 2-3-fold, and 5 mM butyrate by 3-5-fold. Other short-chain fatty acids were found to similarly influence both nuclear receptor and extranuclear T3 levels with the following potency: butyrate greater than valerate greater than propionate greater than acetate. On the contrary, ketone bodies were ineffective. Butyrate increases receptor levels by decreasing receptor degradation, since the apparent t1/2 of receptor disappearance increased by approximately 3-fold in cells incubated with 2 mM butyrate for 48 h. The regulation of receptor number might be secondary to an action of butyrate on regions of the chromatin to which the receptor associates. We then examined the effect of butyrate on histone acetylation. The fatty acid had little effect in increasing the level of multiacetylated forms of H3 and H4 histone when studied in acid-urea gels, but it markedly inhibited the turnover of [3H] acetate from the histone fraction. There was a striking similarity in the dose-response of butyrate for increasing receptor levels and inhibiting histone deacetylation. Furthermore, a very close correlation between receptor levels and [3H]acetate release was also found when different short-chain fatty acids were used. We thus conclude that the effect of butyrate on the receptor could be explained by a modification of the chromatin structure of C6 cells secondary to acetylation.
 ...
PMID:Modulation of thyroid hormone nuclear receptors by short-chain fatty acids in glial C6 cells. Role of histone acetylation. 377 18


1 2 3 4 5 6 7 8 Next >>