Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

With the discovery of mitochondrial DNA (mtDNA) mutations in different neuromuscular disorders, investigations now seek to clarify how the mutant mtDNA induces biochemical and morphologic defects. In one of the most important approaches human mutant mtDNA is transferred into cells that lack mtDNA to examine the relationship between the amount of mutant mtDNA and defects in cell growth, respiration and enzyme activities. The resulting cells are 'cybrids'; these clonal cells contain the heteroplasmic mutant and normal mtDNA from patients with mitochondrial diseases. The mitochondria become functionally defective when the amount of mutant mtDNA exceeds a certain threshold, which differs from mutation to mutation: 60 to 70% in chronic progressive external ophthalmoplegia (CPEO) and probably 95% in the syndromes of mitochondrial encephalopathy, myopathy, lactic acidosis, and stroke-like episodes (MELAS), and myoclonic epilepsy with ragged red fibers (MERRF). This threshold effect may explain the tissue-specific patterns of clinical expression.
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PMID:Mitochondrial diseases. 139 36

The effects of alcohol on the central nervous system can be subdivided into three main categories: the effects of acute intoxication (drunkenness, acute encephalopathy, stroke), the effects of tolerance and ethanol withdrawal (delirium tremens, seizures) and the delayed manifestations of chronic alcohol consumption (cerebellar degeneration, Wernicke's encephalopathy, dementia).
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PMID:[Main involvement of the central nervous system in alcoholism]. 141 Sep 80

We describe the full history and postmortem findings in one of the first identified cases of mitochondrial encephalomyopathy with stroke-like episodes (MELAS). To clarify diagnostic criteria, we analyzed 69 reported cases. The syndrome should be suspected by the following three invariant criteria: (1) stroke-like episode before age 40 yr; (2) encephalopathy characterized by seizures, dementia, or both; and (3) lactic acidosis, ragged-red fibers (RRF), or both. The diagnosis may be considered secure if there are also at least two of the following: normal early development, recurrent headache, or recurrent vomiting. There are incomplete syndromes in relatives of patients with the full syndrome and incomplete syndromes might also be encountered in sporadic cases. Some MELAS patients have features of the Kearns-Sayre syndrome (KSS) or myoclonic epilepsy with ragged-red fibers (MERRF), but none had the full KSS syndrome. In partial or confusing cases, analysis of mitochondrial DNA (mtDNA) may point to the correct diagnosis; however, not all patients with clinical MELAS have had the typical mtDNA point mutation and some patients with the mutation have clinical syndromes other than MELAS.
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PMID:Melas: an original case and clinical criteria for diagnosis. 142

The strongly succinate dehydrogenase-reactive blood vessels (SSV) are shown to have increased numbers of enlarged mitochondria in smooth muscle cells of the vessel wall on electron microscopy. They are seen in biopsied skeletal muscles from patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) at high frequency. The present study was done to examine the incidence of SSV in biopsied muscles from various neuromuscular diseases. Among 107 patients with mitochondrial encephalomyopathies (MEM) including 50 with chronic progressive external ophthalmoplegia (CPEO), 7 with myoclonus epilepsy with ragged-red fibers (MERRF), and 50 with MELAS, SSV were seen in nearly a half of the patients, and comprised approximately 24% of small arteries. On the other hand, SSV in 100 patients with various neuromuscular diseases other than MEM were exceptional, and only one of 8 patients with myotonic dystrophy had SSV. These findings suggest that the SSV are induced by functional abnormality of mitochondria in smooth muscle cells, and that an identification of the SSV is an additional crucial evidence to make a pathological diagnosis of MEM.
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PMID:[Strongly succinate dehydrogenase-reactive blood vessels (SSV) in various neuromuscular diseases]. 142 48

Deletions and point mutations of mitochondrial DNA (mtDNA) of patients with dilated or hypertrophic cardiomyopathy were analyzed using the polymerase chain reaction and fluorescence-based direct sequencing. The patients included are with hypertrophic cardiomyopathy associated with left ventricular dilatation, a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), and a patient with fatal infantile cardiomyopathy. Deletions were frequently seen in mtDNA in patients with dilated cardiomyopathy. The mtDNA was sequenced and the direct repeat at each edge of deletion was identified as (5'-CATCAACAACCG-3') which was located in the ATPase6 gene and in the D-loop region. In a patient with hypertrophic cardiomyopathy associated with left ventricular dilatation, another mutant mtDNA was found not to have directly repeated sequence, and was revealed to jump from nucleotide position 8,992 to position 16,072 of mtDNA resulting in a 7,079 bp deletion. This patient had unique point mutation in the tRNA genes. A G-to-A transition in the tRNA(Cys) gene (nucleotide position 5,821) at the aminoacyl acceptor stem and an A-to-G transition in the tRNA(Thr) gene (nucleotide position 15,951) were identified. In a patient with MELAS, an A-to-G transition in the tRNA(Leu)(UUR) gene (nucleotide position 3,243) was observed. This mutation was located at the 5' end of the dihydrouridine loop of this tRNA molecule, and would disturb its function. In a patient with hypertrophic cardiomyopathy associated with lactic acidosis, mutations of mtDNA should be suspected.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mitochondrial DNA mutations in cardiomyopathy. 143 21

Dementia is in addition to cerebral haemorrhage major symptom of cerebral amyloid angiopathy (CAa). In order to explore the pathological basis for dementia in CAa-related conditions, we made a clinicopathological analysis of CAa, with special attention to dementia. Among 150 patients (mean age 78.6 years) with autopsy-proven intracranial haemorrhage in Tokyo Metropolitan Geriatric Medical Center, CAa with cerebral haemorrhage accounted for 8.0% (12 cases), associated with hypertension and metastatic brain tumour. Among 38 patients with lobar haemorrhage, CAa represented the second most common cause (21.1%) of intracranial haemorrhage after hypertension. A total of 20 patients with CAa (mean age 82.5 years) were studies clinically and pathologically. Hypertension was present in 50%. Thirteen had a history of stroke and others had either ill-defined or no strokes. The average number of strokes 2.9. Fifteen patients (75%) had dementia. Based on the clinicopathological grounds for dementia, CAa-related conditions could be divided into three subtypes: "haemorrhagic", "dementia-haemorrhagic" and "dementia" type. Haemorrhagic type (30%, 6 cases) showed multiple recurrent lobar haemorrhages caused by CAa. Hypertension was present in only 1 patient. The incidence of senile plaques and neurofibrillary tangles was generally correlated with age. Only 1 patient had dementia. The dementia-haemorrhagic type (40%, 8 patients) had recurrent strokes with cerebral haemorrhage after preceding dementia. There were two different neuropathological subsets: CAa with atypical senile dementia of Alzheimer type (SDAT) and CAa with diffuse leucoencephalopathy. Patients with CAa with atypical SDAT had multiple cerebral haemorrhages caused by CAa combined with atypical Alzheimer-type pathology. Patients with CAa with diffuse leucoencephalopathy had cerebral haemorrhages in combination with diffuse white matter damage like Binswanger's subcortical vascular encephalopathy (BSVE). The incidence of senile changes correlated with age. Patients with the dementia type (30%, 6 patients) showed progressive dementia with or without haemorrhage. All had hypertension. They had a combined condition of Alzheimer-type pathology with conspicuous CAa with BSVE. Dementia in CAa-related conditions may be responsible for multiple factors including not Alzheimer-type degeneration, but also diffuse leucoencephalopathy like Binswanger's disease. We also found an asymptomatic type, an ischaemic type, a vasculitis type and an hereditary type in this condition.
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PMID:Dementia in cerebral amyloid angiopathy: a clinicopathological study. 144 72

The segregation of mutant and wild-type mtDNA was investigated in transformants constructed by transferring human mitochondria from individuals belonging to four pedigrees with the MELAS encephalomyopathy-associated mtDNA mutation (MELAS is mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) into human mtDNA-less (rho 0) cells. Five of 13 clonal cell lines containing mixtures of wild-type and mutant mtDNAs were found to undergo a rapid shift of their genotype toward the pure mutant type. The other 8 cell lines, which included 6 exhibiting nearly homoplasmic mutant mtDNA, on the contrary, maintained a stable genotype. Subcloning experiments and growth rate measurements clearly indicated that an intracellular replicative advantage of mutant mtDNA was mainly responsible for the dramatic shift toward the mutant genotype observed in the unstable cell lines.
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PMID:Marked replicative advantage of human mtDNA carrying a point mutation that causes the MELAS encephalomyopathy. 145 94

The Evans blue dilution method and ultrasound dopplerography were used to study the effect of nicergolin on the systemic and cerebral hemodynamics in 31 patients with dyscirculatory encephalopathy against the background of atherosclerotic lesions of the major head arteries. It was established that nicergolin reduces the arterial pressure, diminishes the minute blood volume, cardiac and stroke indices, increases the specific peripheral vascular resistance, the linear blood flow velocity prevailingly in the stenosed major head arteries, results in a regression of the subjective and objective neurological symptomatology. Considering the cardiodepressive effect of nicergolin, this agent is indicated in patients with the hyperkinetic type of the systemic hemodynamics.
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PMID:[The effect of nicergoline on the systemic and cerebral hemodynamics of patients with circulatory encephalopathy and an atherosclerotic lesion of the major cerebral arteries]. 148 25

The neurometric method as introduced by John was used to study three groups of patients with cerebral ischemia, three groups of patients with renal disease and an additional normal control group. The traditional neurometric approach was slightly modified: relative band power values were not expressed as a percentage of the total power per derivation but as a percentage of the "global power"; frequency matrices were used in addition to power matrices. From the study of the three groups of patients with one-sided supratentorial ischemia it appeared that sensitivity and specificity are completely satisfactory when using neurometrics in patients with severe ischemia in the middle cerebral artery territory studied within 48 hours of the onset of the stroke. However, in ischemia patients with less pronounced clinical signs and especially in patients without persistent neurological deficit the sensitivity is much lower. In studying dialysed and non-dialysed renal patients signs of an (often subclinical) encephalopathy could be detected in approximately 37% of all patients. Follow-up studies of the ischemia patients and the renal patients over a period of several years revealed a parallelism between clinical scores and qEEG scores in the ischemia patients; almost all qEEG improvement occurred in the first three months after the stroke. The qEEG profile of the groups of dialysed patients tended to be more or less stable over a period of several years.
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PMID:Neurometrics in cerebral ischemia and uremic encephalopathy. 151 Aug 71

A T-to-C transition mutation at nucleotide position 3,250 in the mitochondrial tRNA(Leu)(UUR) gene was present in a family with mitochondrial myopathy. Two of three muscle biopsies examined had complex I (NADH-ubiquinone oxidoreductase) deficiency. Heteroplasmy of wild and mutant mitochondrial DNA was detected by Nae I digestion of the polymerase chain reaction products with a modified primer. This was found in blood or muscle samples or both from all seven members examined. Similar to the 3,243 mutation in most patients with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes), the new mutation site was located in the dihydrouridine loop and embedded in the binding region of mitochondrial transcription termination factor. Elucidation of the effects of this mutation may help clarify the role of mitochondrial tRNAs and transcription termination.
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PMID:A novel point mutation in the mitochondrial tRNA(Leu)(UUR) gene in a family with mitochondrial myopathy. 151 79


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