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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relationship between the thermosensitivity of cultured brain tumor cells and cytoskeleton was studied. C6 rat glioma cell line (C6 cells) and U-373-MG human glioblastoma cell line (MG cells) were used in monolayer culture. Survival rates at various temperatures were calculated by colony forming assay 10 days after heat treatment. Actin filaments, the main components of microfilaments, were observed by the 7-chloro-4-nitrobenzo-2-oxadiazole phallacidin staining and indirect immunofluorescence staining methods. Alpha-tubulins, the main components of microtubules, were also stained with an indirect immunofluorescence staining method. The morphological changes were investigated by scanning electron microscopy (SEM). Both the C6 cells and the MG cells showed moderate thermosensitivity on the survival curves. Actin filaments were revealed at stress fibers and the ruffles of the leading edge on both cell lines. Stress fibers were well developed in MG cells but were only minor in C6 cells. After heat treatment ruffles and stress fibers were disrupted. However, alpha-tubulins were not affected by heat treatment. SEM showed Swiss-cheese like change of cell surfaces due to many pores with disruption of ruffles and stress fibers after heat treatment. These results suggest that the cytoskeleton, especially microfilaments, may be damaged by hyperthermia.
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PMID:[Thermosensitivity of glioma cells with special reference to changes in cytoskeletons]. 172 43

We measured 3H-thymidine incorporation by human brain tumor cell lines treated with varying doses of gallium nitrate. These DNA synthesis data indicate that the effects of gallium documented for brain tumor cell viability parallel those for alterations in DNA synthesis. The primitive, poorly-differentiated, small, round-cell tumors (medulloblastoma and rhabdomyosarcoma) appear to be more sensitive than glially differentiated neoplasms (glioblastoma) to DNA synthesis inhibition by gallium nitrate.
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PMID:Alteration of DNA synthesis in human brain tumor cells by gallium nitrate in vitro. 176 37

Changes in the fibrinolytic and coagulation values measured preoperatively in brain tumor patients have not been done systematically using individual rather than global assays. Such measurements can provide meaningful information on the status of tumor-host interactions and could potentially help in predicting thromboembolic and hemorrhagic tendencies. A complete fibrinolytic profile including total fibrinolytic activity (TFA), tissue plasminogen activator (t-PA), plasmin inhibitor (PI), plasminogen activator inhibitor (PAI), protein C (PC) and plasminogen (PLG) was obtained preoperatively in 114 brain tumor patients. PLG and PI did not show much variation among the groups. TFA was slightly reduced (15%) in patients with malignant brain tumors. t-PA, however, was abnormally low in several patients and in almost 40% of patients with brain metastasis. PAI was above the upper limit of normal in approximately 50% of the patients but particularly in glioma, glioblastoma and metastasis patients. Finally, mean PC was abnormally increased in the glioblastoma and metastasis groups (p less than 0.001). This is the first study that has measured protein C in brain tumor patients. In conclusion, plasma fibrinolytic levels show marked changes in a substantial number of brain tumor patients prior to surgery--suggesting an ongoing tumor-host interaction.
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PMID:Plasma fibrinolytic profile in patients with brain tumors. 182 14

We report a case of association of a brain tumor with multiple intestinal polyposis (Turcot's syndrome) and offer a critical analysis of the relevant literature with a view to revising the classification of the syndrome in relation to familial multiple polyposis and Gardner's syndrome. For this purpose, we considered only cases of intestinal polyposis associated with a primary neuroepithelial tumor (medulloblastoma, glioma, or glioblastoma) as originally described by Turcot. Differences emerged, depending on the central nervous system tumor type, which suggests that this neoplastic association may be classified as two distinct syndromes.
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PMID:Association between neuroepithelial tumor and multiple intestinal polyposis (Turcot's syndrome): report of a case and critical analysis of the literature. 184 39

The immunohistochemical distribution of alpha and beta subunits of S-100 protein (S-100 alpha, S-100 beta, respectively) in 138 cases of human brain tumors was investigated by the avidin-biotin immunoperoxidase method. Brain tumors can be divided into four groups: group 1 [S-100 alpha (+) and/or S-100 beta (+)]; astrocytoma, glioblastoma, ependymoma, subependymoma, oligodendroglioma, choroid plexus papilloma, gangliocytoma, meningioma, chordoma, malignant melanoma. Group 2 [S-100 alpha (+) and S-100 beta (-)]; pineoblastoma, pituitary adenoma, craniopharyngioma, rhabdomyosarcoma. Group 3 [S-100 alpha (-) and S-100 beta (+)]; acoustic Schwannoma. Group 4 [S-100 alpha (-) and S-100 beta (-)]; medulloblastoma malignant lymphoma, germinoma. The S-100 beta immunoreactivity pattern in brain tumors was similar to those obtained using conventional anti-S-100 protein sera. In the first group of brain tumors both the number of positively stained tumor cells and the staining intensity were generally greater for S-100 beta than for S-100 alpha with a few exceptions including one gemistocytic astrocytoma, one subependymoma, one malignant melanoma, and some cases of glioblastomas. As to the relationship between malignancy and S-100 protein in glioma, S-100 beta immunoreactivity decreased according to degree of malignancy, while that of S-100 alpha varied, suggesting a heterogeneity of tumor cells in glioblastomas. Immunostaining for S-100 alpha and S-100 beta might become a useful diagnostic procedure in brain tumors and may give us more detailed and precise data of S-100 protein in brain tumors.
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PMID:Immunohistochemical study on the distribution of alpha and beta subunits of S-100 protein in brain tumors. 188 40

Single-strand conformation polymorphism analysis of polymerase chain reaction products (PCR-SSCP analysis) was used for detection of mutations of the p53 gene in surgical specimens of human brain tumors. Six of 45 brain tumors showed mobility shifts in the analyses. These six tumors also showed loss of a normal allele. The samples were examined further by direct sequencing. Results showed that four of them had single-base substitutions and the other two had deletions of one and eight base pairs. Five of the six mutations detected were clustered in highly conserved regions of the p53 gene. The frequency of p53 gene mutations in primary brain tumors examined was 9.8%. We also found two new polymorphic markers in the p53 gene, one in intron 7 and the other in an Alu repeat in exon 11. Both markers could be detected by SSCP analysis. Using these two markers, we found two cases of loss of heterozygosity in other brain tumor specimens. Results suggested that aberrations of the p53 gene were not correlated with the malignancy of some types of brain tumors such as anaplastic astrocytoma and glioblastoma, contrary to previous observations on colorectal cancers.
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PMID:Detection of p53 gene mutations in human brain tumors by single-strand conformation polymorphism analysis of polymerase chain reaction products. 188 8

Nuclear proteins obtained from human brain tumor cell lines by differential salt extraction were subjected to high-resolution two-dimensional electrophoresis. Several hundred spots were detectable in the low salt (0.4 M NaCl) extract using silver staining. These patterns exhibited remarkable differences between the different cell lines we analyzed. A less complex pattern occurred when nuclei were subsequently treated with high salt (2.5 M NaCl/5 M urea). We compared the electropherograms from various human glioblastoma cell lines and found them very similar and even a high degree of similarity occurs between glioblastomas and other human tumor cell lines. Beside these more general observations we detected several proteins at least enriched in human glioblastomas which were totally absent in low grade astrocytomas and nonglial tumors. They could be separated from the bulk of nonspecific proteins by simple modifications of the isoelectric focusing conditions. From these results we conclude that nuclear proteins obtained by sequential salt extraction and separated by two-dimensional techniques may provide tumor specific proteins suitable for antibody production.
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PMID:Nuclear and DNA-binding proteins in human brain tumors. 191 44

A brain tumor is composed not only of tumor cells, but also of normal glial, mesenchymal, endothelial, and microglial cells, as well as lymphocytes and macrophages. Therefore, homogeneous cultures of tumor cells, currently used for chemosensitivity testing, do not accurately model in situ tumors. We have developed an in vitro growth assay for brain tumors that includes normal host cells and is potentially useful for studies of chemotherapy and biological response modifiers. Human glioblastoma xenografts (U251-MG) were resected from mice, minced, and explanted into agarose-coated culture wells. After 5 to 7 days, microtumors emerged as expanding spheroids, which grew most efficiently in minimum essential medium supplemented with 20% fetal calf serum, 90% of which was replaced on alternate days. The growth rate and bromodeoxyuridine labeling index were similar in the microtumors and the xenografts, and light microscopy revealed highly cellular, pleomorphic tumors with high mitotic activity in both. Immunohistochemical studies also demonstrated the persistence of macrophages in both xenografts and microtumors. Microtumors treated for 2 hours with 75 mumol/L 1,3-bis-(2-chloroethyl)-1-nitrosourea showed a growth delay of 1.5 days; no effects were observed after treatment with lower doses. This in vitro system for brain tumor culture may provide a useful technique for the study of new therapies as an alternative to in vivo xenograft studies using immunodeficient animals.
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PMID:A three-dimensional micro-organ culture system optimized for in vitro growth of human malignant brain tumors. 192 6

Little is known about the sensitivity of human glioblastoma cells to hyperthermia alone and in combination with other therapies. We carried out in vitro cell survival studies on the human glioblastoma cell line U-87MG and our model canine glioma canine brain tumor (CBT) cells after multimodality treatment. Ionizing radiation was administered to flasks of cells in logarithmic growth at 500 rads (5 Gy) with consecutive treatment by hyperthermia, 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU), or cisplatin. Cells were treated with single doses of BCNU at 5 microM with sequentially added radiation or hyperthermia and at 1 to 2 micrograms/ml of cisplatin with hyperthermia. Hyperthermia was administered in a precision controlled water bath at 44 degrees C for 30 minutes in combination with chemotherapy or radiation. In general, the sensitivity of U-87MG and CBT cells was similar for all test regimens. For example, colony formation efficiency decreased by 64% in CBT cells and by 64.4% in U-87MG cells after hyperthermia alone at 44 degrees C for 60 minutes. All combinations of BCNU, hyperthermia, and radiation administered in vitro produced enhanced cell killing, but the effects of multiple modalities were generally additive in both cell lines.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:In vitro response of human glioblastoma and canine glioma cells to hyperthermia, radiation, and chemotherapy. 194 32

Five radiotracers may be used for single-photon emission computed tomography (SPECT) imaging of brain tumors, namely technetium 99m pertechnetate, iodine-123 amphetamine derivatives, 99mTc-hexamethyl propylene amine oxime (HMPAO), thallium 201, and 123I alpha methyl tyrosine. Of these, pertechnetate may be considered as an "historical" procedure in brain tumors. However, there may be some equivocal cases in computed tomography or magnetic resonance imaging, where this procedure may still be used. In 1981, 123I isopropyl amphetamine was first used in brain tumors. Further studies showed, however, that IMP is not a useful tool for brain imaging in tumorous lesions. In 1986, 99mTc HMPAO appeared on the European market as a new tumor imaging agent. Some useful clinical results were obtained in patients before and after chemotherapy or radiotherapy. Thallium-201 was incidentally noted to accumulate in tumors. Using a threshold index, this agent can be used to distinguish low-versus high-grade lesions. The most promising agent for brain tumor SPECT is 123I-alpha methyl tyrosine, which shows potential to evaluate therapeutic procedures in brain tumors and may improve the differentiation between abscess and glioblastoma. The most promising aspect is the differentiation of tumor recurrences and scar tissue after brain surgery.
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PMID:Single photon emission computed tomography imaging of brain tumors. 199 25


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