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

A factor present in the supernatant of an established human glioma cell line U-251 MG strongly suppresses feline sarcoma virus (FeSV) focus forming activity on feline embryo fibroblasts. The factor was identified as mycoplasma arginini. The enriched mycoplasma fraction had no cytpathogenic effect on the glioma cells or on the embryonic feline indicator cells. An antiserum prepared against this strain of mycoplasma abolished the inhibition. The exact mechanism is not known but arginine depletion in the medium seems to be an important factor.
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PMID:Interaction of feline sarcoma virus (FeSV) and mycoplasma. 627 39

The chronic inhalation toxicity and carcinogenicity of ethylene oxide (EO) and propylene oxide (PO) were evaluated in a 2-year inhalation bioassay. Five groups of male weanling Fischer 344 rats, 80 per group, were exposed at 0 ppm (shared control; filtered air), 50 ppm EO, 100 ppm EO, 100 ppm PO, or 300 ppm PO (7 hr/day, 5 days/week) for 104 weeks. Body weights from rats exposed to EO and PO at all exposure concentrations were significantly reduced compared to controls. A statistically significant increase in mortality was observed in all groups of exposed rats compared to controls. Skeletal muscle atrophy in the absence of any sciatic nerve neuropathology was found in rats exposed at 100 ppm EO and 300 ppm PO. Statistically significant associations between EO exposure and an increased incidence of the following rat neoplasms were observed: mononuclear cell leukemia, peritoneal mesothelioma, and mixed cell brain glioma. Among rats exposed to PO there was a dose-dependent increase in the incidence of complex epithelial hyperplasia in the nasal passages, and two adenomas were detected in the nasal passages of rats exposed at 300 ppm PO. The incidence of adrenal pheochromocytomas was elevated in both PO exposure groups, but not in a dose-related manner. All rat groups were affected by an outbreak of Mycoplasma pulmonis infection which occurred about 16 months into the study. This infection alone and in combination with the epoxide exposures affected the survival of rats in this study, and influenced the development of the proliferative lesions in the nasal mucosa of the PO-exposed rats. No treatment-related changes in any clinical chemistry or urinalysis indices were detected. PO exposure did not increase the incidence of the three neoplasms associated with EO exposure; however, adrenal pheochromocytomas and proliferative lesions of the nasal cavity were increased in rats exposed to PO.
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PMID:Carcinogenic and toxicologic effects of inhaled ethylene oxide and propylene oxide in F344 rats. 648 93

Mycoplasma fermentans (incognitus strain) is a recently identified new human pathogen and suspected cofactor in acquired immune deficiency syndrome. Because this organism appears to exert strong immunosuppressive properties of its own, we decided to investigate whether it was capable of inducing MHC class II expression, as we have observed for other species of mycoplasma. In this report we demonstrate that M. fermentans (incognitus strain) is capable of producing factors that increase MHC class II expression as well as MHC class I expression on the myelomonocytic cell line, WEHI-3 cells. We also present data showing that these mycoplasmal factors induce small, although significant, increases in MHC class I and II antigens on a mouse glioma cell line, G26-20, and MHC class II expression on the human monocyte cell lines, U-937 and HL-60. Using nuclear run-on analysis, we show that the mycoplasma-induced increase in MHC expression is at least partially due to an increase in transcription of the MHC genes. Furthermore, we show that the factor that mediates this activity is sensitive to protease treatment, indicating that it is, at least in part, protein. These results demonstrate that M. fermentans (incognitus strain) is capable of modulating the expression of immunologically important MHC genes in both murine and human cell lines, which may prove to be an important factor in the pathogenesis of this organism.
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PMID:Characterization of MHC induction by Mycoplasma fermentans (incognitus strain). 824 66

Mycoplasma contamination of cell cultures is a frequently observed problem. Due to the inconspicuous growth in cell cultures, periodical screening procedures represent the only protection. Many influences of mycoplasma on cell culture parameters have been described. We addressed the question of whether mycoplasma contamination affects the most frequently used cytotoxicity assay, the tetrazolium based MTT assay. We contaminated C6 glioma cells with mycoplasma and performed MTT assays with doxorubicin, vincristine, etoposide and cisplatinum under various conditions. Contaminated cells demonstrated significant different results when tested with the MTT assay than mycoplasma free controls. Differences were not detectable when cells were counted as toxicity assay. Due to an additional reduction of tetrazolium by mycoplasmas, contaminated cells appeared up to 15 fold resistant to doxorubicin, vincristine and etoposide, but not to cisplatinum. Differences decreased with decreasing drug doses and decreasing plated cell count. Our findings confirm the compelling need for periodical mycoplasma screening, especially when tetrazolium based cytotoxicity assay (MTT) are used.
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PMID:Falsification of tetrazolium dye (MTT) based cytotoxicity assay results due to mycoplasma contamination of cell cultures. 1036 83