Linked Life Data

7818252

Source:http://linkedlifedata.com/resource/pubmed/id/7818252

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-2-7
pubmed:abstractText
In the majority of patients with mitochondrial encephalomyopathies, signs and symptoms appear in the first three decades of life. Here we report on a group of 9 older patients (> 69 years old) with late-onset skeletal myopathy characterized by focal accumulations of deleted mitochondrial DNAs (mtDNAs) and altered muscle energy status, suggestive of a primary mitochondrial disease. The clinical phenotype was somewhat variable. However, all patients shared a common feature of insidious moderate proximal muscle weakness; some also showed fatigability and axial muscle weakness. In situ hybridization analysis demonstrated accumulations of messenger RNAs transcribed from deleted mtDNAs in a relatively large number of muscle fibers in the patient group. These fiber segments appeared as ragged red with the modified Gomori trichrome stain and hyperreactive with a modified succinate dehydrogenase stain. Most were negative for cytochrome c oxidase activity. On transverse sections their mean frequency was 0.69% (trichrome) and 1.97% (succinate dehydrogenase) significantly above control levels. Multiple mtDNA deletions were demonstrated by the polymerase chain reaction in both the patients and an age-matched control group, but not in younger control subjects. Phosphorus 13 magnetic resonance spectroscopy of resting muscle showed a decreased phosphocreatine-inorganic phosphate ratio in the patient group. The myopathy in this group of patients appears to result from mitochondrial dysfunction related to the clonal expansion of different mtDNA deletions in individual fiber segments. While the origin of the mtDNA mutations is not clear, the phenotype seems to represent an exaggerated form of what is observed in the normal aging process.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0364-5134
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Late-onset mitochondrial myopathy.
pubmed:affiliation
Montreal Neurological Institute, Quebec, Canada.
pubmed:publicationType
Journal Article, Case Reports, Research Support, Non-U.S. Gov't