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)

Clinical diffusion magnetic resonance (MR) imaging in humans started in the last decade with the demonstration of the capabilities of this technique of depicting the anatomy of the white matter fibre tracts in the brain. Two main approaches in terms of reconstruction and evaluation of the images obtained with application of diffusion sensitising gradients to an echo planar imaging sequence are possible. The first approach consists of reconstruction of images in which the effect of white matter anisotropy is averaged -- known as the isotropic or diffusion weighted images, which are usually evaluated subjectively for possible areas of increased or decreased signal, reflecting restricted and facilitated diffusion, respectively. The second approach implies reconstruction of image maps of the apparent diffusion coefficient (ADC), in which the T2 weighting of the echo planar diffusion sequence is cancelled out, and their objective, i.e. numerical, evaluation with regions of interest or histogram analysis. This second approach enables a quantitative and reproducible assessment of the diffusion changes not only in areas exhibiting signal abnormality in conventional MR images but also in areas of normal signal. A further level of image post-processing requires the acquisition of images after application of sensitising gradients along at least 6 different spatial orientations and consists of computation of the diffusion tensor and reconstruction of maps of the mean diffusivity (D) and of the white matter anisotropic properties, usually in terms of fractional anisotropy (FA). Diffusion-weighted imaging is complementary to conventional MR imaging in the evaluation of the acute ischaemic stroke. The combination of diffusion and perfusion MR imaging has the potential of providing all the information necessary for the diagnosis and management of the individual patient with acute ischaemic stroke. Diffusion-weighted MR, in particular quantitative evaluation based on the diffusion tensor, has a fundamental role in the assessment of brain maturation and of white matter diseases in the fetus, in the neonate and in the child. Diffusion MR imaging enables a better characterisation of the lesions demonstrated by conventional MR imaging, for instance in the hypoxic-ischaemic encephalopathy, in infections and in the inherited metabolic diseases, and is particularly important for the longitudinal evaluation of these conditions. Diffusion-weighted MR imaging has an established role in the differential diagnosis between brain abscess and cystic tumour and between epidermoid tumour and arachnoid cyst. On the other hand, the results obtained with diffusion MR in the characterisation of type and extension of glioma do not yet allow decision making in the individual patient. Diffusion is one of the most relevant MR techniques to have contributed to a better understanding of the pathophysiological mechanisms of multiple sclerosis (MS). In fact, it improves the specificity of MR in characterising the different pathological substrata underlying the rather uniform lesion appearance on the conventional images and enables detection of damage in the normal-appearing white and grey matter. In MS patients the ADC or D values in the normal-appearing white matter are increased as compared to control values, albeit to a lesser degree than in the lesions demonstrated by T2-weighted images. In addition, the D of the normal appearing grey matter is increased in MS patients and this change correlates with the cognitive deficit of these patients. Histogram analysis in MS patients shows that the peak of the brain D is decreased and right-shifted, reflecting an increase of its value, and the two features correlate with the patient's clinical disability. Ageing is associated to a mild but significant increase of the brain ADC or D which is predominantly due to changes in the white matter. Region of interest and histogram studies have demonstrated that D or ADC are increased in either the areas of leukoaraiosis or the normal-appearing white matter in patients with inherited cerebral autosomal dominant arteriopathy with subcortical infarcts and stroke or sporadic ischaemic leukoencephalopathy. Diffusion changes might be a more sensitive marker for progression of the disease than conventional imaging findings. In neurodegenerative diseases of the central nervous system such as Alzheimer's disease, Huntington's disease, hereditary ataxias and motor neuron disease, quantitative diffusion MR demonstrates the cortical and subcortical grey matter damage, which is reflected in a regional increase of D or ADC, but also reveals the concomitant white matter changes that are associated with an increase in D or ADC and decrease in FA. In all these diseases the diffusion changes are correlated to the clinical deficit and are potentially useful for early diagnosis and longitudinal evaluation, especially in the context of pharmacological trials.
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PMID:Diffusion-weighted MR of the brain: methodology and clinical application. 1577 87

S100B is an astrocyte calcium-binding protein that plays a regulatory role in the cytoskeleton and cell cycle. Moreover, extracellular S100B, a marker of glial activation in several conditions of brain injury, has a trophic or apoptotic effect on neurons, depending on its concentration. Hyperglycemic rats show changes in glial parameters, including S100B expression. Here, we investigated cell density, morphological and biochemical alterations in primary cortical astrocytes from rats and C6 glioma cells cultured in high-glucose medium. Astrocytes and C6 glioma cells have a reduced content of S100B and glial fibrillary acidic protein when cultured in a high-glucose environment, as well as a reduced content of glutathione and cell proliferation rate. Although these cells have been used indistinctly to study S100B secretion, we observed a contrasting profile of S100B secretion in a high-glucose medium: a decrease in primary astrocytes and an increase in C6 glioma cells. Based on the in vitro neurotrophic effects of the S100B protein, our data suggest that chronic elevated glucose levels affect astrocyte activity, reducing extracellular secretion of S100B and that this, in turn, could affect neuronal activity and survival. Such astrocyte alterations could contribute to cognitive deficit and other impairments observed in diabetic patients.
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PMID:S100B content and secretion decrease in astrocytes cultured in high-glucose medium. 1735 Jan 41

There has been an increase in the prevalence of adults diagnosed with and treated for primary brain tumors. Cognitive deficits are a common long-term effect in brain tumor survivors. The objective of this paper is to examine whether these deficits are specific to those diagnosed with and treated for a primary brain tumor. A systematic review of the medical literature from 2002 to 2012 was conducted to investigate neurocognitive deficits in brain tumor survivors (post-primary treatment) compared to healthy controls. Four studies were identified that met all inclusion criteria. Gliomas were the most common form of tumor included. Neuropsychological evaluation identified cognitive deficits in brain tumor survivors on tests of working memory, cognitive control and flexibility, cognitive processing speed, visual searching, planning and foresight, and general attention. While age, education, and gender can influence cognitive function, the present review indicates that deficits exist beyond those accounted for by these factors. Many primary brain tumor survivors are involved in roles (e.g., employee, parent, spouse/partner, student) that require optimal performance of these cognitive skills. Future research should evaluate brain tumor survivors on functional challenges resulting from these cognitive sequelae and develop effective ways to mitigate them.
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PMID:Neurocognitive deficits following primary brain tumor treatment: systematic review of a decade of comparative studies. 2397 55

Antibodies against LGI1 (leucin-rich glioma-inactivated 1 protein) are associated with limbic encephalitis (LE), which is characterized by a favorable outcome following immunotherapy. Here, we present two cases, where antibodies against LGI1 were detected in the sera 36 and 53 months after acute LE, respectively, and none of the patients received immunotherapy. LE showed characteristics of LGI1 encephalitis in both cases, including low sodium content in the sera; disorientation, hallucination, short-term memory loss; and epileptic seizures. One patient had faciobrachial tonic seizures. MRI indicated bilateral inflammation of the hippocampus in one case. We reviewed longitudinal clinical and MRI data covering 53 and 36 months after LE without immunotherapy, respectively. Both patients became seizure-free and spontaneously recovered with mild/moderate cognitive impairment. No relapses have been observed. Follow-up brain MRI indicated early hippocampal sclerosis and global brain atrophy in one case characterized by more pronounced cognitive deficit. Memory and verbal fluency were affected most during the natural course of LGI1 encephalitis. LGI1 encephalitis had a monophasic course and spontaneously improved, suggesting that a relatively benign natural course may contribute to the favorable outcome observed after immunotherapy. Our data also indicate that LGI1 antibodies can be present in the sera without clinical disease activity.
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PMID:Natural course of LGI1 encephalitis: 3-5 years of follow-up without immunotherapy. 2492 80