Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We encountered a case of brain abscess that was difficult to differentiate from glioblastoma. Localized 1H-MRS was found to be useful for obtaining information on the biochemical status of brain abscess. The peak of lipid and high residual peak of NAA (N-acetyl-aspartate) were observed in the cystic lesion of the brain abscess by 1H-MRS. The NAA/Cho (Choline-containing compounds) ratio in brain parenchyma showing an edematous lesion before therapy gradually increased with the relief of inflammation.
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PMID:Brain abscess observed by localized proton magnetic resonance spectroscopy. 785 33

Astrocytoma (WHO grade II, III), glioblastoma, malignant melanoma, and normal glial cell cultures, established from biopsies, were investigated by 1H MRS. At a 1H resonance frequency of 500 MHz (11.75 T) a high spectral resolution was achieved in 1D 1H spectra; in conjunction with 2D shift-correlated (COSY) MRS, resonances of alanine, aspartate, choline, creatine, glutamate, glutamine, hypotaurine, myo-inositol, phosphocreatine, phosphoryl-ethanolamine, phosphoryl-choline, lactate, lysine, N-acetylaspartate, taurine, threonine and valine could be identified. T1 relaxation times for the most prominent compounds are presented. T1 values of lactate ranged between 450 ms and 850 ms. The intensity of the lactate signal revealed differences between individual spectra, but exhibited no correlation between different tumor specimens or degree of malignancy. It was shown that the lactate signal at 1.3 ppm is covered by peaks arising from threonine and fatty acids. The choline signal level varied among spectra of different tumors, among tumors with similar degree of malignancy, and within the same tumor. Further preliminary differences due to aspartate, inositol and glutamine/glutamate were found in 1D and 2D COSY spectra between normal glial cells as well as different tumors. These results indicate that some differences observed in in vivo spectra may be attributable to secondary macroscopic structural changes (hypoxia, necrosis) and not to tumor inherent characteristics. Further correlation between in vivo and in vitro spectroscopy is therefore required.
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PMID:High-resolution one- and two-dimensional 1H MRS of human brain tumor and normal glial cells. 808 Jul 12

In order to investigate the clinical characteristics, neuroimaging findings, pathological features, treatment, and outcomes, and to provide valuable guidance for the diagnosis and management of intracranial gangliogliomas, 34 cases of intracranial gangliogliomas were retrospectively analyzed. This study included 23 males and 11 females. Age at operation ranged from 17 days to 50 years. All patients had preoperative magnetic resonance imaging (MRI). Computed tomography (CT), magnetic resonance spectroscopy (MRS), 18F-FDG-PET (positron emission tomography), and 99Tc-HMPAO-SPECT (single photon emission computed tomography) were also performed in some cases. All pathological specimens and all available neuroimages were re-evaluated. The follow-up period varied from 12 to 89 months (mean 36 months). Seizure was the most common presenting symptom (85%). Tumor calcification was detected by CT scan in six of 11 cases. Seventeen gangliogliomas (50%) showed cystic components and 18 tumors (53%) were enhanced on MRI. All temporal lobe gangliogliomas were located intracortically and most of them had poor demarcation on MRI. In comparison with the contralateral normal area, the gangliogliomas showed a reduced Cho/Cr and NAA/Cr ratio, and an increased Cho/NAA ratio. On 18F-FDG-PET, gangliogliomas were usually hypometabolic. HMPAO-SPECT indicated tumor hypoperfusion or isoperfusion. A gross total resection was achieved in 25 patients. Tumor progression was observed in three patients who underwent an incomplete tumor resection. Two of them underwent a malignant transformation to a glioblastoma. Twenty-seven patients could carry on their normal life activity with the Karnofsky Performance Scale (KPS) of more than 80. Even though ganglioglioma is a slowly growing benign tumor, which could be demonstrated by magnetic resonance spectroscopy (MRS), PET, and SPECT, there is a chance of malignant transformation, especially in cases of incomplete tumor resection. Gangliogliomas should be resected gross totally, if feasible, to achieve the best long-term outcomes.
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PMID:Intracranial ganglioglioma: preoperative characteristics and oncologic outcome after surgery. 1224 Nov 12

The evaluation of the response to radiation therapy in brain tumor patients is a major and an important issue. Although CT and MRI can measure changes in tumor size, it is difficult to use these imaging methods to evaluate the viability or the proliferation activity of a tumor. In this study, we investigated the metabolite changes in glioma patients using 1H-MRS from before to after radiation therapy, to see whether or not early metabolic changes occur during therapy. Seven patients with histologically proven glioma (1 astrocytoma, 1 anaplastic astrocytoma, 2 oligoastrocytoma, 1 oligodendroglioma, 2 glioblastoma) were examined by means of 1H-MRS using a point-resolved spectroscopy (PRESS) sequence with a repetition time of 2,000 ms and echo times of 68 ms, 136 ms and 272 ms. The 1H-MRS was evaluated by both the spectrum pattern and the quantification of the metabolites. As to radiation therapy, each patient received a total dose of 64.8 Gy (1.8 Gy/fraction) with a 10-MeV linear accelerator. The results revealed that the concentration of choline-containing compounds (Cho) was 4.55 +/- 1.08 mmol/kg wet weight before radiation therapy and was reduced to 2.69 +/- 0.56 mmol/kg wet weight (p < 0.01) after radiation therapy. Moreover, both the N-acetylaspartate (NAA) peak and creatine/phosphocreatine (t-Cr) peak were lower after radiation therapy than before. The peaks of both the lipids (Lip) and lactate (Lac) were higher after radiation therapy than before. In conclusion, Cho concentration is thought to be a useful marker for the evaluation of early post-radiation response. The effect of radiation therapy can be evaluated according to the value of Cho. Further long-term MRS study is needed to prove whether or not the decrease of the Cho value in the present study will change before recurrence at later stages.
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PMID:[Changes in 1H-MRS in glioma patients before and after irradiation: the significance of quantitative analysis of choline-containing compounds]. 1261 52

Automation of proton magnetic resonance spectroscopy (MRS) in recent years has made it possible for MRS measurement to be performed in a shorter time than before, and the number of reports of its usefulness for the assessment of glioma malignancy has been increasing in the past several years. We studied the efficacy of proton MRS when used for glioma and conducted clinicopathological examination of glioma. The subjects were 15 patients who had received a pathological diagnosis of glioma at our hospital (6 cases of glioblastoma, 1 case of anaplastic astrocytoma, 4 cases of low-grade astrocytoma, and 4 cases of radiation necrosis); Siemens Magnetom Vision 1.5T was used for the study. Regions of interest (ROIs) were defined as the areas where abnormal signals were found on magnetic resonance imaging (MRI). Areas of primary peaks, such as choline (Cho), N-acetylaspartate (NAA), and lactate (Lac), were measured, and the ratios to normal brain tissue were examined. This study revealed a tendency of increased malignancy of glioma with a decrease in NAA. Some cases also displayed a decrease in Cho with an increase in malignancy. Assessment of malignancy must not be based on a single ROI alone, but several ROIs should be assessed comprehensively. Measurement was difficult when the tumor volume was small. Because diagnosis of very early glioma by MRS seemed difficult, other adjunctive diagnoses may be necessary. Proton MRS is very useful for diagnosis of glioblastoma.
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PMID:Clinicopathological examination of glioma by proton magnetic resonance spectroscopy background. 1569 68

In vivo magnetic resonance spectroscopy (MRS) studies of glial brain tumours reported that higher grade of astrocytoma is associated with increased level of choline-containing compounds (Cho) and decreased levels of N-acetylaspartate (NAA) and creatine and phosphocreatine (Cr). In this work, we studied the metabolism of glioma tumours by in vitro proton magnetic resonance spectroscopy (1H-MRS). 1H-MR spectra were recorded in vitro from perchloric acid extracts of astrocytoma (WHO II) and glioblastoma multiforme (WHO IV) samples. We observed differences between astrocytoma and glioblastoma multiforme in the levels of Cho, alanine, lactate, NAA, and glutamate/glutamine. In astrocytoma samples, we found higher MR signal of NAA and lower signal of Cho and alanine. MR spectra of glioblastoma samples reported significantly higher levels of lactate and glutamate/glutamine. In contrast, levels of Cr were the same in both tumour types. We also determined NAA/Cr and Cho/Cr ratios in the tumour samples. The NAA/Cr ratio was higher in astrocytomas than in glioblastomas multiforme. Conversely, the Cho/Cr ratio was higher in glioblastoma multiforme. The results indicate that MRS is a promising method for distinguishing pathologies in human brain and for pre-surgical grading of brain tumours.
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PMID:In vitro study of astrocytic tumour metabolism by proton magnetic resonance spectroscopy. 1630 27

Recent advances in magnetic resonance imaging (MRI) have allowed the evaluation of metabolic, diffusion and hemodynamic features of malignant gliomas. The aim of this study was to evaluate whether such information provided useful, complementary information to conventional MRI for improving the evaluation of glioblastoma extent. Ten patients with glioblastoma multiforme underwent conventional MRI, proton MR spectroscopic imaging (1H-MRSI), perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI). Metabolite signals, including normalized choline, N-acetylaspartate, creatine and lactate/lipids, were obtained by 1H-MRSI; apparent diffusion coefficient (ADC) by DWI; and relative cerebral blood volume (rCBV) by PWI. In edematous-appearing areas, 3 multiparametric patterns were identified: infiltrating tumor, with abnormal metabolite ratios, lower ADC and higher rCBV; pure edema, with normal metabolite ratios, higher ADC and lower rCBV; and tumor-infiltrated edema, with abnormal metabolite ratios and intermediate ADC and rCBV. In normal-appearing areas, 2 multiparametric patterns were identified: tumor-infiltrated tissue, with abnormal metabolite ratios and higher rCBV; and normal tissue, with normal MR parameters. The combination of 1H-MRSI, DWI and PWI features contributed to delineation of glioblastomas, offering information not available with conventional MRI. This approach may enhance the assessment of brain gliomas, providing useful information for guiding stereotactic biopsies, surgical resection and radiation treatment.
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PMID:Spectroscopic, diffusion and perfusion magnetic resonance imaging at 3.0 Tesla in the delineation of glioblastomas: preliminary results. 1716 79

Brainstem gliomas in adults are rare tumors, with heterogeneous clinical course; only a few studies in the MRI era describe the features in consistent groups of patients. In this retrospective study, we report clinical features at onset, imaging characteristics and subsequent course in a group of 34 adult patients with either histologically proven or clinico-radiologically diagnosed brainstem gliomas followed at two centers in Northern Italy. Of the patients 18 were male, 14 female, with a median age of 31. In 21 of the patients histology was obtained and in 20 it was informative (2 pilocytic astrocytoma, 9 low-grade astrocytoma, 8 anaplastic astrocytoma and 1 glioblastoma). Contrast enhancement at MRI was present in 14 patients. In all of the 9 patients who were investigated with MR spectroscopy, the Cho/NAA ratio was elevated at diagnosis. In 8 of the patients, an initial watch and wait policy was adopted, while 24 were treated shortly after diagnosis with either radiotherapy alone [4] or radiotherapy and chemotherapy [20] (mostly temozolomide). Only minor radiological responses were observed after treatments; in a significant proportion of patients (9 out of 15) clinical improvement during therapy occurred in the context of radiologically (MRI) stable disease. Grade III or IV myelotoxicity was observed in 6 patients. After a follow-up ranging from 9 to 180 months, all but 2 patients have progressed and 14 have died (12 for disease progression, 2 for pulmonary embolism). Median overall survival time was of 59 months. Investigation of putative prognostically relevant parameters showed that a short time between disease onset and diagnosis was related to a shorter survival. Compared with literature data, our study confirms the clinical and radiological heterogeneity of adult brainstem gliomas and underscores the need for multicenter trials in order to assess the efficacy of treatments in these tumors.
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PMID:Natural history and management of brainstem gliomas in adults. A retrospective Italian study. 1829 27

Gliomas are heterogeneous brain tumors and prognosis and treatment are dependent on the highest histological grade present. Stereotactic biopsy is associated with an inherent risk of sampling error. Magnetic resonance spectroscopy (MRS) uses clinical MR scanners to provide chemical in addition to conventional information. MRS studies in brain tumors have found increased levels of choline-containing compounds (Cho) and decreased levels of N-acetylaspartate (NAA), creatine (Cr) and phosphocreatine (PCr) which are all associated with increased grade of glioma. We propose the use of MRS-guided stereotactic biopsy of astrocytomas to increase diagnostic yield and reduce the sampling error rate. MRS was performed on two patients undergoing stereotactic biopsy for suspected astrocytoma. Spectral peak heights of the metabolites Cho at 3.2 parts per million (ppm) chemical shift, NAA at 2.0 ppm and lipid (Lip) at 1.2 ppm, were measured. Biopsy targets were selected from the voxels with the highest Cho/NAA and normalised against Cho levels in the contralateral normal tissue, as well as those with highest lipid content. The biopsies were taken and tissue diagnosis was obtained via standard histological techniques. Histological grade was found to be different in one case: the region with a high Lip/Cr and Cho/NAA ratios showed glioblastoma, whereas the region with high Cho/NAA but low Lip/Cr ratios showed anaplastic astrocytoma. The second patient had high Cho/NAA ratio but low Lip/Cr ratio in both targets and the histology revealed anaplastic astrocytoma in both samples. MRS is a useful biomedical imaging tool for diagnosing and grading astrocytomas. Targeting regions with highest lipid content can potentially improve the diagnostic yield and minimize sampling error in stereotactic biopsy.
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PMID:Targeting regions with highest lipid content on MR spectroscopy may improve diagnostic yield in stereotactic biopsy. 1833 98

We have developed a human brain tumor model in immunodeficient rats that gradually changes its phenotype by serial passages in vivo, from a highly infiltrative, non-angiogenic one with numerous stem cell markers [low-generation (LG) tumor] to a more typical glioblastoma one with extensive angiogenesis and necrosis [high-generation (HG) tumor]. In this study we determined the metabolic properties of these two phenotypes, using (1)H MRS. The LG tumors showed an intact blood-brain barrier and normal vascular morphology, as shown by MRI and Hoechst staining. In contrast, the HG tumors exhibited vascular leakage and necrosis. The animals with HG tumor had raised concentrations of choline and myo-inositol, and decreased concentrations of glutamate and N-acetylaspartate. In the LG tumor group, similar changes in metabolic concentrations were detected, although the alterations were more pronounced. The LG tumors also had higher concentrations of choline, taurine, and lactate. Subdividing the LG and HG tumors into large and small tumors revealed a significant increase in choline and decrease in glutamate as the LG tumors increased in size. Our results show that metabolic profiles produced by (1)H MRS can be used to distinguish between two distinct glioblastoma phenotypes. More pronounced anaerobic metabolism was present in the LG stem-cell-like tumors, suggesting a more malignant phenotype.
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PMID:Two distinct tumor phenotypes isolated from glioblastomas show different MRS characteristics. 1861 1


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