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)

Experimental animal models resembling most human brain tumor types can be induced by exposure to oncogenic viruses or chemical carcinogens: Astrocytomas and glioblastoma multiforme can be produced experimentally by intracerebral injection of oncornaviruses, whereas medulloblastomas, choroid plexus papillomas, and ependymomas can be induced by the papovaviruses. Adenoviruses have been utilized to cause medulloepitheliomas, neuroblastomas, and retinoblastomas. All three groups of viruses can result in sarcoma production. Gliomas represent the primary tumor type induced in the brain by chemical carcinogens. These autochthonous tumor systems are reviewed, with emphasis on methods, tumor type, latency period, advantages, and disadvantages. In addition, recent investigations of molecular events involved in neoplastic transformation by chemical carcinogens are summarized.
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PMID:Chemical- and virus-induced brain tumors. 20 37

A radioimmunoassay for ng quantities of DNA was developed. [125l]lododeoxyuridine-labeled DNA was used as the antigen, and the serum of a lupus erythematosus patient served as the source of antibody. The level of free DNA in the serum of 173 patients with various types of cancer and in 55 healthy individuals was determined by this radioimmunoassay. DNA concentration in the normal controls had a range of 0 to 100 ng/ml with a mean of 13 +/- 3 ng/ml (S.E.). For comparison purposes, the range of 0 to 50 ng/ml was designated as normal, and 93% of controls were found in this range. In the cancer patients, the DNA concentration ranged from zero to mug levels with a mean of 180 +/- 38 ng/ml. Fifty % of the patients values were found in the range of 0 to 50 ng/ml; the other 50% were between 50 and 5000 ng/ml. No correlation could be seen between DNA levels and the size or location of the primary tumor. Significantly higher DNA levels, however, were found in the serum of patients with metastatic disease (mean of 209 +/- 39 ng/ml), as compared to nonmetastatic patients (mean 100 +/- 30, p less than 0.02). After radiation therapy in lymphoma, lung, ovary, uterus, and cervical tumors, the levels decreased in 66 to 90% of the patients, whereas in glioma, breast, colon, and rectal tumors, the DNA levels decreased only in 16 to 33% of the patients. Generally, the decrease in DNA concene of tumor size and reduction of pain. Conversely, when DNA levels either increased or remained unchanged, a lack of response to the treatment was noted. Of 17 patients who died within a year, 13 showed DNA levels that remained high or unchanged, whereas only 4 showed lower levels during treatment. Persistent high or increasing DNA levels in the circulation, therefore, may signal a relapse and are probably a poor prognostic sign. The relatively high percentage (50%) of cancer patients with apparently normal DNA levels would suggest that this test may have low diagnostic value. It should be pointed out, however, that all these patients represent a selected group considered for radiation therapy, usually after surgery and/or chemotherapy. It is possible that a better correlation between DNA levels and cancer will be obtained prior to the initiation of treatment. On the other hand, DNA in the serum may be an important tool for the evaluation of therapy or the comparison of different regimens.
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PMID:Free DNA in the serum of cancer patients and the effect of therapy. 83 66

Nuclear RNA polymerase activity was studied in homotransplanted rat glial tumors where the primary tumor was produced by transplacental injection of ethylnitrosourea. Alpha amanitin, cycloheximide, and rifampicin were tested as inhibitors of this activity. Alpha amanitin significantly inhibited RNA polymerase activity in all tumors. This indicated that the major nuclear RNA polymerase activity seen in vitro in the tumor nuclei was RNA polymerase II. This is similar to the activity seen in normal glial nuclei. Cycloheximide and rifampicin which have no effect on RNA polymerase activity in normal glial nuclei inhibited about 20% of the polymerase activity in three of the tumors. The size and multiplicity of the nucleoli in these tumor cells suggests that RNA polymerase I could account for the activity which is inhibited by cycloheximide.
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PMID:RNA polymerase activity in homotransplanted rat brain tumors initially induced by ethylnitrosourea. 114 4

A strategy for improved treatment of malignant gliomas grade III-IV is presented. The strategy can briefly be described as surgical removal of the bulky tumor, high precision external irradiation of small brain volumes over and near the primary tumor area with high doses from proton beams, and thereafter treatment of spread cells with toxic radionuclides. Proton beams suitable for this are under development. The clinical effects of high single doses on malignant gliomas grade III-IV are presently tested with conventional gamma radiation. Targeting of spread glioma cells with toxic radionuclides tagged to epidermal growth factor, EGF, or to EGF-dextran is presently tested in experimental systems and can, in the near future, be tested in combination with local high doses of external proton radiation. The possibilities to combine proton beams with EGF-guided neutron capture therapy will be considered in a longer perspective.
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PMID:Strategy for planned radiotherapy of malignant gliomas: postoperative treatment with combinations of high dose proton irradiation and tumor seeking radionuclides. 131 Sep 61

In this study a human glioma-derived intracerebral tumor model was analyzed histologically and examined by image-guided 1H NMR spectroscopy. It was shown that histological characteristics such as cellular subpopulation and necrosis of the primary tumor were preserved in the implants. Usually circumscript tumor growth was present with tumor cells invading the surrounding brain parenchyma. It was demonstrated that tumor growth and tumor metabolism could be monitored by image-guided 1H NMR spectroscopy in a longitudinal study. One of the initial changes noticed was the rise of the lactate signal in the tumor region followed by an increase of the choline and a decrease of N-acetyl-aspartate and phosphocreatine signals. Even before tumor invasion in brain adjacent to the central tumor area could be demonstrated by NMR imaging increased lactate and moderately increased choline signals were measured in these regions. By histopathological examination these areas were shown to be infiltrated by single tumor cells. These observations indicate that image-guided 1H NMR spectroscopy could play an important role in the study of brain tumor biology, especially in the case of changing tumor metabolism during growth.
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PMID:Image-guided 1H NMR spectroscopical and histological characterization of a human brain tumor model in the nude rat; a new approach to monitor changes in tumor metabolism. 133 42

Two cases of stereotactically induced and spontaneously metastasizing neoplasms in the rat and the cat brain are reported. In the rat, a malignant Schwannoma derived from initially supratentorially implanted RN6 cells developed a second tumor in the posterior cranial fossa. In the cat, a highly malignant polymorphous anaplastic glioma induced by implantation of cloned rat glioma cells (F98) into the left internal capsule developed small tumor cell nests along the ependyma of the ipsilateral ventricle. In precontrast magnetic resonance imaging (MRI) of both cases, the primary tumor was detectable only by a very weak hypointensity and through a shift of the midline. No metastases were apparent. Application of the metallated paramagnetic porphyrin derivative manganese(III) tetraphenylporphine sulfonate (MnTPPS) resulted in a remarkable contrast enhancement between tumoral and normal tissue, which was evident not only in the primary tumor but also in the small metastases. These observations demonstrate for the first time that MnTPPS is an efficient MRI contrast agent for the detection of metastases from primary brain neoplasms and, in consequence, support the hypothesis of its selective binding to tumor cells.
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PMID:Identification of intracranial liqor metastases of experimental stereotactically implanted brain tumors by the tumor-selective MRI contrast agent MnTPPS. 150 24

Previous studies have suggested that structural abnormalities involving the short arm of chromosome 9 are frequently associated with gliomas. The alpha-, beta-, and omega-interferon (IFNA, IFNB1, and IFNW, respectively) and the methylthioadenosine phosphorylase (MTAP) genes have been mapped to the short arm of chromosome 9, band p22. Homozygous deletions of these genes have been reported in many leukemia- and glioma-derived cell lines. In this report, we present a detailed analysis of partial and complete homozygous or hemizygous deletions of DNA sequences on 9p in human cell lines and primary tumor samples of glioma patients. Ten of 15 (67%) glioma-derived cell lines had hemizygous or homozygous deletion of IFN genes or rearrangement of sequences around these genes, while 13 of 35 (37%) primary glioma tumor samples had hemizygous (8 tumors) or homozygous (5 tumors) deletion of the IFN genes. The shortest region of overlap of these deletions maps in the interval between the centromeric end of the IFN gene cluster and the MTAP gene. In the cell lines and primary tumors examined, these gross genomic alterations were seen only in association with high grade or recurrent gliomas. Our observations confirm that loss of DNA sequences on 9p, particularly the IFN genes, occurs at a significant frequency in gliomas, and may represent an important step in the progression of these tumors. These results are consistent with a model of tumorigenesis in which the development or progression of cancer involves the loss or inactivation of a gene or several genes that normally act to suppress tumorigenesis. One such gene may be located on 9p; this gene may be closely linked to the IFN genes. Nevertheless, loss of the IFN genes, when it occurs, may play an additional role in the progression of these tumors.
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PMID:Molecular analysis of deletions of the short arm of chromosome 9 in human gliomas. 156 21

Peripheral blood mononuclear cells (PBM) from normal donors and patients with recurrent glioma were activated initially for 48-72 h with phytohemagglutinin-P (PHA) and recombinant human interleukin-2 (IL-2), and then proliferated in vitro for up to 5 months with IL-2. These cells are termed mitogen-stimulated lymphokine-activated T killer (T-LAK) cells. We measured patterns of T-LAK cell growth, in vitro cytolytic activity on a panel of continuous and primary tumor cells, and the phenotypes of the cells in these cultures. Lymphocyte viability declined dramatically over the first 3-5 days; and then the remaining cells in these cultures began to divide and maintained a constant 30-36 h doubling time for long periods in vitro. Phenotyping revealed that cells in the initial few days of culture were heterogeneous, but became almost totally CD3 T cells after 7-10 days in culture. The T-LAK cells from individual normal donors and cancer patients demonstrated a non-genetically restricted cytolytic ability against a panel of both continuous cell lines and primary autologous and allogeneic glioblastoma cells in vitro. This technique provides a method of generating large numbers of autologous cytolytic T cells with non-restricted anti-tumor activity that can be derived from peripheral blood mononuclear cells.
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PMID:Generation of stimulated, lymphokine activated T killer (T-LAK) cells from the peripheral blood of normal donors and adult patients with recurrent glioblastoma. 201 99

Antigen expression in a human glioblastoma was investigated by immunochemical methods in the primary tumor, the first and second recurrence, a permanent cell line derived from the first recurrence and in its xenotransplantation tumors. In the primary tumor, GFAP, vimentin, S100, Leu-7 and glioma-associated antigens (GAA) as defined by the monoclonal antibodies (mAbs) MUC 2-39, MUC 8-22 and MUC 2-63 were markedly expressed. In the recurrences, gradual loss of GFAP and Leu-7 could be observed, whereas S100, vimentin and GAA gave similar results to those in the primary tumor. In contrast, fibronectin and collagen IV, which were restricted to the vessel walls in the primary tumor, were represented in sarcomatous areas of the recurrences. In some of these areas, co-expression of glial cell markers was observed. In short-term cell cultures, expression of glia- and glioma-associated antigens as well as fibronectin and collagen IV was comparable to that of the recurrent tumor tissue. In long-term passages, immunoreactivity of GFAP, Leu-7 and S100 decreased, whereas GAA, vimentin and fibronectin increased. Collagen IV positive cells were not visible beyond passage 15. Transplantation tumors were only partly positive for glial cell markers, but revealed strong immunoreactivity for GAA, fibronectin and collagen IV. With these observations we confirm that the phenotypic variability of glioma cells makes it difficult to identify the origin of cells in human glioblastomas from their antigenicity.
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PMID:Antigen variation in a human glioblastoma: from the primary tumor to the second recurrence, permanent cell line and xenotransplantation tumors. 206 11

The potential of 6-[18F]fluoro-L-fucose (6-[18F]FFuc) for assessing glycoconjugate synthesis in tumors with positron emission tomography (PET) was investigated. Using the tissue sampling method with five tumor models, different time-radioactivity profiles were found: a nearly constant level in Lewis lung carcinoma (3LL) and different clearance patterns in others. Rapid clearance in normal tissues resulted in preferable uptake ratios for tumor imaging of brain and pancreas. Metabolic studies and the L-fucose loading effects on the tissue uptake proved the tracer to be a biochemically active L-fucose analog. Imaging of the intracranial rat glioma and 3LL in lungs or hepatomas in mice by autoradiography (ARG) and intramuscular VX-2 carcinoma in rabbits by PET was demonstrated. Using double-radionuclide ARG, similar distribution images of 6-[18F]FFuc and 14C-L-fucose but different tumor-to-liver uptake ratios were found. A metastasis model seemed to show a higher uptake of both tracers as compared to a primary tumor model.
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PMID:6-[18F]fluoro-L-fucose: a possible tracer for assessing glycoconjugate synthesis in tumors with positron emission tomography. 226 99


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