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Biomedical subjects

R Sakuta

Publications and source records attributed to R Sakuta.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Leigh encephalopathy: histologic and biochemical analyses of muscle biopsies.

To elucidate the pathogenesis of Leigh encephalopathy, histologic, biochemical, and mitochondrial DNA analyses were performed on biopsied muscles from 33 patients with the clinical characteristics of this disorder. On muscle histochemistry, cytochrome c oxidase activity was decreased or absent in 7 patients (21%), although none had ragged-red fibers. In 2 patients with cytochrome c oxidase deficiency, staining for this enzyme was poor in the muscle fibers and fibroblasts but was normal in the arterial wall, indicating tissue-specific involvement. Ten patients (30%) had biochemical defects, including 2 with pyruvate dehydrogenase complex, 4 with cytochrome c oxidase, 1 with NADH-cytochrome c reductase (complex I), and 3 with multiple complex deficiencies. None of the 28 patients in whom muscle mitochondrial (mt)DNA was analyzed had DNA deletions or point mutation at nucleotide positions 3,243 or 8,344. These results indicate that the underlying defect in Leigh encephalopathy is heterogeneous because only 30% of patients had enzyme defects demonstrable in muscle biopsy material.

Child↗
PubMedDate not supplied

Fatal infantile mitochondrial encephalomyopathy with complex I and IV deficiencies.

A 4-month-old male infant had a fatal infantile mitochondrial disease associated with cardiomyopathy. He had elevated lactate concentrations in blood and cerebrospinal fluid and an increased lactate/pyruvate ratio. Histochemical analysis of muscle biopsy revealed several ragged-red fibers on modified Gomori trichrome stain and mildly decreased cytochrome c oxidase (complex IV) activity. Complex I and IV activities of the respiratory chain in muscle were decreased to about 35% of normal values biochemically; subunits of the two complexes were decreased nonselectively on immunoblotting. Mitochondrial DNA analysis failed to detect any mutation. Complex I and IV deficiencies should be considered as one of the causes of fatal infantile mitochondrial disease.

Acidosis, Lactic↗
PubMedDate not supplied

Myopathy with abnormal distribution of dystrophin, growth retardation, mental retardation, and hypospadia.

A 9-year-old boy with severe growth retardation, mild mental retardation, and hypospadia had a high serum CK level without muscle weakness and atrophy. Muscle biopsy revealed a moderate variation in fiber size with a few necrotic and scattered regenerating fibers. Although muscle membranes were clearly stained by immunostaining with antibody to dystrophin, N-terminal region (2-5E2), fibers in groups revealed striking, intense staining with the other antibody, C-terminal region (4C5), suggesting some aberration of the dystrophin gene near the C-terminal area. His unique clinical features, as well as myopathy, are reported, although further study is necessary to clarify the relationship between the anomalous conditions and dystrophin abnormalities.

Adrenal Insufficiency↗