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

Dose-effect relations have been evaluated by the treatment of cell cultures (9L glioma cells of rat as monolayers and tumor spheroids, L 1210 cells of mice) with activated isophosphamide, adriamycin, epirubicin and 6 MeV electrons. The magnitude of synergistic effects obtained by combined treatment modalities is strictly pH-dependent, but even for tumor spheroids it appears that there exists an optimum time-interval between drug administration and consecutive irradiation. The determination of the intracellular pH value with the help of pH sensor microelectrodes and 31P NMR spectroscopy indicates that 31P spectroscopy only provides the global pH of the complete culture (average value), whereas the local pH can only be determined by sensors. The ATP-concentration before and after irradiation depends significantly on the glucose supply of the culture medium.
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PMID:Biophysical aspects of the integrated combination of cytostatic drugs with radiotherapy. Part 2: Dose-effect relationships and 31P NMR spectroscopy of L 1210 cells (monolayers) and 9L glioma cells (monolayers and tumor spheroids) treated with activated isophosphamide, adriamycin, epirubicin and 6 MeV electrons. 188 66

31P-NMR spectroscopy has been used to study the energy metabolism and the NMR visibility of ATP and intracellular Pi of the C6 glioma cell line and rat astrocyte grown on microcarrier beads with the following results. 1. In vivo NMR spectra of C6 glioma cells and rat astrocytes indicate that these cells were able to maintain their level of ATP resonances during a long anoxic period (more than an hour). Both cell types were sensitive to ischemia which induced a loss of ATP resonances within 40 min. Glucose starvation induced by 40% decrease in ATP resonances correlated to a 50% increase in the intensity of the Pi signal. These changes corresponded to a new steady state which could be reversed by reperfusing the cells with a glucose-containing medium. 2. In contrast to in vivo data, 31P-NMR analyses of perchloric acid extracts of cells incubated in a glucose-free medium showed that their ATP and Pi contents were unchanged during starvation. The changes of NMR visibility of the metabolites in living C6 cells were correlated to modifications of their macroscopic longitudinal relaxation times, evolving from 0.30 +/- 0.08 s and 6.6 +/- 1.5 s in the presence of glucose to 0.68 +/- 0.26 s and 3.2 +/- 0.9 s in the absence of glucose for ATP and Pi, respectively. The changes of the NMR detectability of ATP and Pi indicate that changes in their microenvironment occur during glucose starvation, suggesting the existence of different pools of these metabolites within the cells. 3. Under various experimental conditions, i.e. anoxia, ischemia and glucose starvation, rat astrocytes in primary culture showed a very similar behavior to that of C6 cells, suggesting a similar adaptability to the nature of the energy supply for both the normal and the malignant cell.
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PMID:Phosphorus-31 nuclear magnetic resonance of C6 glioma cells and rat astrocytes. Evidence for a modification of the longitudinal relaxation time of ATP and Pi during glucose starvation. 199 80

Clinical phase I/II studies have been performed at the Swiss Institute for Nuclear Research (SIN) since February 1982. Fifty-two out of 249 patients accepted for pion treatment by the end of 1986 were treated for malignant glioma with high dose pion irradiation. A substantial influence of their radioresistance was expected from increased radiation quality due to the contribution of high LET particles from pion capture, and by the possibility of target volume shaping and dose distribution related to the dynamic spot-scan conformation technique. The patients' treatment followed a dose escalation program with total doses from 2720-3420 cGy, fraction sizes from 170 to 205 cGy (90% isodose, minimum target dose), and treatment times from 4 to 5 weeks. 12/52 patients received an accelerated treatment with 3280 cGy in 14-22 days. 49/52 patients are eligible: 3 with astrocytoma of clinical aggressive behaviour, 14 with anaplastic astrocytoma (median age 42 years), and 32 patients with glioblastoma (median age 52 years). 8/49 patients had total/subtotal tumour resection, 19 patients a stereotactic biopsy. The patients were divided into three groups according to total dose, and a fourth group which received the accelerated treatment. There was no statistically significant difference in the median survival rate between the four groups, which was 13 months for the non-glioblastoma patients and 9 months for the glioblastoma patients. No radiation necrosis and no demyelination was found in 17 patients (6 recraniotomies, 11 autopsies). In 10/17 patients, clearly identifiable tumour cells were not demonstrated. NMR findings showed the tumour-surrounding oedema mostly stimulated by tumour necrosis and tumour progression. From these findings, further dose escalation programs, together with a shaping of the target volume close to the tumour, are not contraindicated.
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PMID:Anaplastic astrocytoma and glioblastoma: pion irradiation with the dynamic conformation technique at the Swiss Institute for Nuclear Research (SIN). 210 74

The reoperation of patients with recurrence of cerebral glioma is a technique offering survival with a good quality of life. The accepted criteria are a Karnofski index until reoperation greater than or equal to 70, young age, and a favourable histologic grade of tumor. NMR offers better sensitivity than other neuroimaging techniques for the detection of tumoral extension, local and at a distance, and allows a good tumoral resection. We report a patient with recurrence of a cerebral astrocytoma grade II with the criteria for reoperation, but when we performed NMR a dissemination of the tumor to the posterior fossa was seen, and reoperation was consequently counter-indicated. We discuss the mechanism of the extension of cerebral gliomas, the value of neuroimaging techniques and the role of reoperation in this context. We consider it necessary to perform NMR prior to reoperation in this special group of patients with a cerebral glioma recurrence.
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PMID:[Reintervention in gliomas: the necessity of nuclear magnetic resonance]. 224 70

The effect of manganese(III)tetraphenylporphine sulfonate (MnTPPS) on the relaxation enhancement of NMR images (MRI) was studied in experimental brain tumors in rats. Brains were inoculated with the glioma cell line F98 12 to 19 days before the NMR experiment, and the effect of MnTPPS (0.25 mmol/kg body weight) was investigated 2 and 4 days after intraperitoneal injection. After MnTPPS addition tumors could be clearly distinguished by the brightness from the surrounding brain whereas they were barely visible without contrast enhancement. At SE time of 25 msec and TR time of 3500 msec the ratio of magnetization values of tumor versus normal grey matter increased from 0.98 +/- 0.08 to 1.24 +/- 0.09 (means +/- SD). When TR was shortened to 1100 msec contrast enhancement further increased to 1.77 +/- 0.25. These results demonstrate for the first time that MnTPPS is an efficient agent for contrast enhancement of brain tumors.
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PMID:Proton relaxation enhancement in experimental brain tumors--in vivo NMR study of manganese(III)TPPS in rat brain gliomas. 239 36

Two new antineoplastic agents, a nitrosourea and a DNA-bis-intercalator have been studied in vivo by 31P magnetic resonance spectroscopy on a rat glioma and Walker carcinoma. On rat glioma, spectra are modified when the tumor is treated by the nitrosourea, showing the depletion of high-energy phosphates. On Walker carcinoma both drugs delay the tumor evolution to necrosis, showing important levels of high-energy phosphates on NMR spectra. There appears to be a great dependence upon energy metabolism during chemotherapy, depending on the nature and physiology of the observed tumor.
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PMID:In vivo 31P MRS in new antineoplastic agents evaluation on experimental tumor models. 246 78

Fossel et al. have recently proposed the proton NMR examination of plasmatic lipoproteins--and more precisely the determination of an index obtained from the averaged linewidth of the CH2 and CH3 resonances--as a possible tool for detection of cancer. Many evaluations conducted on an international basis have demonstrated that initial expectations were not met and that the test lacked sensitivity, specificity, and predictive value to be accepted as a screening and diagnostic tool. In our evaluation we have collected plasma from healthy subjects, from patients with various kinds of cancer at different stages of evolution and therapy, and from patients suffering from a variety of pathologies, including benign tumors. In accordance with Chmurny et al., we observed that the linewidth index (LWI) is precise and reproducible when care is taken in the handling and storage of samples and in the fasting of subjects. After finding no predictive value to the test, we have reanalyzed the spectra and studied the variations of the ratio defined by the methylene signal area over the methyl signal area. This ratio is significantly increased in cancer. Furthermore, it offers a better separation of statistical populations permitting a more precise discrimination between cancer, other pathologies and controls. We have also found that malignant tumors arising from mesenchyma (sarcoma, leukemia, lymphoma) induce less important variations in the CH2/CH3 ratio than adenocarcinoma or glioma, when such differences cannot be documented using the LWI. These observations are particularly interesting since they might bring new information on the metabolic modifications of the LWI and the CH2/CH3 ratio might reflect the embryologic origin of the tumors and raise the issue of the heterogeneity of cancer disease.
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PMID:[Modification of the relative plasma concentrations of methyl and methylene groups in cancer: a study using proton NMR spectroscopy]. 251 67

Surface coil NMR spectroscopy was used to monitor the hyperglycemia-induced alterations in pH and blood flow in vivo in C6 gliomas implanted both subcutaneously and intracerebrally in rats. Tumor pH was calculated from the chemical shift difference between PCr and Pi in the 31P NMR spectra. Subcutaneous glioma pH decreased 0.8 units by 1 h after intraperitoneal administration of an aqueous 50% glucose solution (6 g glucose per kg body weight). In contrast, hyperglycemia failed to significantly alter the pH of intracerebral gliomas which were monitored for 90 min following administration of glucose. Tumor blood flow (TBF) was determined both pre- and post-glucose administration using deuterium NMR by monitoring the time course of D2O washout following intratumoral injection of saline D2O. Subcutaneous and intracerebral TBF were found to have an average change of -78.1% (range -47.4 to -93.3%, n = 5) and -21.1% (range +6.0 to -37.8%, n = 9), respectively. In addition, laser Doppler blood flow measurements of rat skin and subcutaneous glioma revealed a dramatic reduction in blood flow in both tissues following glucose administration. These results indicate that the effects of acute hyperglycemia are site dependent and that hyperglycemia alone is not beneficial for inducing intracellular acidosis in intracerebral tumors.
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PMID:In vivo 31P and 2H NMR [corrected] studies of rat brain tumor pH and blood flow during acute hyperglycemia: differential effects between subcutaneous and intracerebral locations. 255 87

High-resolution 1H surface coil NMR spectroscopy (MRS) was used to evaluate in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. Tumor cells (C6 glioma cells) were stereotaxically placed in the right hemisphere superficially. 1H MRS was performed using 5-mm surface coils implanted over the right hemisphere and the water was suppressed using a binomial sequence. As the intracerebral tumor size increased, there was a marked decrease in the N-acetyl aspartate level and an increase in the 1.3 ppm peak. Edition of this peak showed that lactate increased but lipids increased much more than lactate. Moreover the ratio between the choline-phosphocholine and creatine-phosphocreatine peaks changed. This study demonstrates that high-resolution surface coil 1H MRS can be used to monitor changes in metabolism associated with growth of an experimentally induced rat brain tumor in situ.
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PMID:In vivo 1H NMR spectroscopy of an intracerebral glioma in the rat. 271 5

A GC/MS method is described for monitoring the relative amount of glucose degraded to lactate via the hexose monophosphate shunt (HMPS) in neoplastic cells. C6 glioma cells were incubated in medium supplemented with [1-13 C]glucose and medium containing [1-13C]glucose with 0.001 mM phenazine methosulfate (PMS). The ratio of the [13C]lactate to [12C]lactate determined from the measurement of the m/z 219/220 and 117/118 ions of the trimethyl silyl derivative, was used to calculate HMPS activity. PMS increased HMPS activity in C6 glioma cells by 3.2 and 4.8 fold at 2 and 12 hours of incubation respectively. GC/MS results were compared with 1H NMR measurements of the [3-13C]lactate/[3-12C]lactate ratio. The GC/MS method was found to require less sample size and yielded better sensitivity than the NMR method.
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PMID:Gas chromatographic-mass spectrometric analysis of hexose monophosphate shunt activity in cultured cells. 291 95


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