Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a 26-year-old male who developed aphasia due to an ischemic cerebral infarction caused by MELAS (myoencephalophatic syndrome with lactic acidosis and cerebral ischemia). The most common causes of cerebral infarction in young patients were ruled out by laboratory investigations. The diagnosis of MELAS was suspected on the basis of past history of epilepsy, migraine and progressive sensory deafness, and increased resting blood lactic acid. Cerebral computed tomography showed bilateral caudate-putamen-pallidal calcification and nuclear magnetic resonance scan disclosed a left ischemic parietal-temporal-occipital infarction. The diagnosis was confirmed by muscular biopsy, which was characteristic of mitochondrial myopathy showing "red disarrayed" fibers in the histologic modified trichromic Gomori stain. Our patient showed that MELAS should be considered in young adults with cerebral infarction. The diagnosis should initially be suspected on a clinical basis, and confirmed by the presence of "red disarrayed" fibers with modified trichromic Gomori stain histologic muscle study.
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PMID:[Cerebral infarct in a young adult, as the presenting form of myeloencephalopathic syndrome with lactic acidosis and cerebral ischemia]. 236 6

Numerous epidemiologic observations reporting high prevalence of migraine among young individuals with stroke as well as dysfunction of cerebral arteries during migraine attacks prompt speculation on the existence of a comorbidity between the two disorders. The recent finding of silent infarct-like brain lesions in migraineurs reinforced this hypothesis and raised questions on whether migraine may be a progressive disorder rather than simply an episodic disorder. Stroke can occur during the course of migraine attacks with aura, supporting the assumption of a causal relation between the two diseases. Migraine may accentuate other existing risk factors for stroke, and both jointly increase the risk of cerebral ischemia outside of migraine attacks. In this regard, the role of migraine might be that of predisposing condition for cerebral ischemia. Migraine and ischemic stroke may be the end phenotype of common pathogenic mechanisms. Evidence of a migraine-stroke relation in cases of specific disorders, such as CADASIL (cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy) and MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), strongly supports this concept. Finally, acute focal cerebral ischemia can trigger migraine attacks, and, thus, migraine may be the consequence of stroke. In this paper, we will review contemporary epidemiologic studies, discuss potential mechanisms of migraine-induced stroke and comorbid ischemic stroke, and pose new research questions.
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PMID:Migraine and ischemic stroke: a debated question. 1846 Oct 80

Nitric oxide (NO) is a free radical and a signaling molecule in several pathways, produced by nitric oxide synthase (NOS) from the conversion of L-arginine to citrulline. Supplementation of L-arginine has been used to treat MELAS (mitochondrial encephalopathy with lactic acidosis and stroke like syndrome), a mitochondrial disease caused by the m.3243A>G mutation. Low levels of serum arginine and endothelium dysfunction have been reported in MELAS and this treatment may increase NO in endothelial cells and promote vasodilation, decreasing cerebral ischemia and strokes. Although clinical benefits have been reported, little is known about NO synthesis in MELAS. In this study we found that osteosarcoma derived cybrid cells with high levels of m.3243A>G had increased nitrite, an NO metabolite, and increased intracellular NO, demonstrated by an NO fluorescent probe (DAF-FM). Muscle vessels from patients with the same mutation had increased staining in NADPH diaphorase, suggestive of increased NOS. These results indicate increased production of NO in cells harboring the m.3243A>G, however no nitrated protein was detected by Western blotting. Further studies are necessary to clarify the exact mechanisms of L-arginine effect to determine the appropriate clinical use of this drug therapy.
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PMID:Nitric oxide synthesis is increased in cybrid cells with m.3243A>G mutation. 2326 69