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Biomedical subjects

E Bonilla

Publications and source records attributed to E Bonilla.

At least 181 records · Page 10Linked to original sources
PubMed1988

Immunocytochemical study of nebulin in Duchenne muscular dystrophy.

We used antibodies to nebulin in immunocytochemical studies. In normal muscle, nebulin was localized at the I band. The protein was also present in most fibers from all 15 Duchenne muscular dystrophy (DMD) patients studied, including patients who seemed to lack nebulin in electrophoretic gels and patients who demonstrated deletions of DNA in the region of Xp21. These results conform to other evidence that nebulin is not the primarily affected gene product in DMD; it may be affected secondarily.

Child↗
PubMed1988

Deletions of mitochondrial DNA in Kearns-Sayre syndrome.

We have identified large-scale deletions in muscle mitochondrial DNA (mtDNA) in seven of seven patients with Kearns-Sayre syndrome (KSS). We found no detectable deletions in the mtDNA of ten non-KSS patients with other mitochondrial myopathies or encephalomyopathies, or three normal controls. The deletions ranged in size from 2.0 to 7.0 kb, and did not localize to any single region of the mitochondrial genome. The proportion of mutated genomes in each KSS patient ranged from 45% to 75% of total mtDNA. There was no correlation between the size or site of the deletion, biochemical abnormality of mitochondrial enzymes, or clinical severity. The data bolster arguments that KSS is a unique disorder and genetic in origin.

Adolescent↗
PubMed1988

Immunocytochemical study of dystrophin in muscle cultures from patients with Duchenne muscular dystrophy and unaffected control patients.

Using immunocytochemical methods, the localization of dystrophin, the gene product affected in Duchenne muscular dystrophy (DMD) in aneural, differentiating human muscle cultures, was studied. Dystrophin was not demonstrable in undifferentiated myoblasts from control patients and from two patients with DMD. After myoblast fusion, the protein was found in circumscribed sarcoplasmic patches, in the perinuclear area, and along the surface of all normal multinucleate myotubes, with more mature myotubes showing predominantly sarcolemmal distribution. There was no staining in myotubes from one DMD patient and only faint diffuse fluorescence in myotubes from the second affected boy, however. These data provide further evidence that dystrophin is a sarcolemma-associated protein, that it is developmentally regulated, and that it is absent or greatly reduced in quantity in skeletal muscle cultures from patients with DMD.

Adult↗
PubMed1987

Electron cytochemical study of the muscle cell surface.

The lectins wheat germ agglutinin and limulus polyphemus were used as cytochemical probes to study the ultrastructural localization of sialic acid at the cell surface of rat muscle fibers. In addition cytochemical studies employing strontium as an electron-dense marker were also carried out to investigate cation binding sites at the muscle cell surface. The results showed binding of the lectins to the glycocalyx, caveolae and the basal lamina of the muscle fibers. These binding sites matched the ones observed in the cytochemical studies using strontium as a marker. Based on these observations we suggest that the glycocalyx, caveolae and the basal lamina of the muscle fiber may be involved in the binding of Ca++ and that significant amounts of Ca++ may be normally present at the muscle cell surface.

Animals↗
PubMed1987

Mitochondrial myopathies.

The mitochondrial myopathies or encephalomyopathies with known biochemical defects can be divided into 5 groups: (1) defects of mitochondrial transport, such as CPT deficiency or carnitine deficiencies; (2) defects of substrate utilization, such as PDHC deficiency or defects of beta-oxidation; (3) defects of the Krebs cycle, such as fumarase deficiency; (4) defects of oxidation-phosphorylation coupling, such as Luft disease, and (5) defects of the respiratory chain. These disorders are reviewed, with particular emphasis on the defects of the respiratory chain. Defects of complex I, III and IV show remarkable clinical and biochemical heterogeneity. All 3 complexes contain some subunits encoded by mtDNA and others encoded by nuclear DNA. At least some of the cytoplasmically made subunits appear to be tissue specific and may be developmentally regulated, thus explaining the genetic heterogeneity of these disorders.

Adenosine Triphosphatases↗
PubMed1987

Application of nile blue and nile red, two fluorescent probes, for detection of lipid droplets in human skeletal muscle.

Using frozen sections from human muscle biopsies, we assessed the value of Nile blue and Nile red, two fluorescent probes, as stains for lipid droplets in normal and pathological skeletal muscle fibers. In normal muscle, lipid storage disorders, and mitochondrial myopathies, Nile blue stained the lipid droplets as yellow-gold fluorescent structures. The lipid droplets were also seen as yellow-gold fluorescent structures in Nile red-stained sections, but the outstanding feature in these preparations was the staining of the membrane network of the muscle fibers and membrane proliferations in pathological muscle as red-orange fluorescent structures. These results suggest that both Nile blue and Nile red stains are useful for visualization of lipid droplets and membrane proliferations in pathological muscle biopsies.

Cell Membrane↗
PubMed1987

Mitochondrial encephalomyopathy and partial cytochrome c oxidase deficiency.

A 52-year-old man had slowly progressive weakness and wasting of limb-muscles, sensorineural hearing loss, and complex partial seizures. CT showed cerebral atrophy, but he was not demented. Muscle biopsy showed ragged-red fibers and decreased histochemical stain for cytochrome c oxidase. Biochemical studies showed decreased cytochrome c oxidase activity in crude muscle extracts and in isolated mitochondria (44 and 30% of normal), while other mitochondrial enzymes were normal. A comparable decrease of immunologically reactive enzyme protein was shown by immunotitration with antibodies against human heart cytochrome c oxidase. Partial defects of cytochrome c oxidase may cause adult-onset, slowly progressive mitochondrial encephalomyopathies.

Atrophy↗
PubMed1987

Benign reversible muscle cytochrome c oxidase deficiency: a second case.

A 6-week-old boy had generalized weakness, requiring assisted ventilation, and lactic acidosis. At 6 months, the lactic acidosis resolved, and the patient started to improve; assisted ventilation was discontinued at 15 months. Muscle biopsies at 4 and 11 months showed accumulation of mitochondria, lipid, and glycogen; cytochrome c oxidase (COX) activity was 11% of the lowest control in the first biopsy and 57% in the second. Immunocytochemistry and immunotitration showed presence of immunologically reactive enzyme protein in both biopsies. This case confirms a previous report of benign infantile myopathy due to reversible COX deficiency. The severe fibrosis in the second biopsy may explain the slower rate of clinical recovery in this child.

Biopsy↗
PubMed1986

Myopathy and fatal cardiopathy due to cytochrome c oxidase deficiency.

A 3-day-old girl had a syndrome of lethargy and lactic acidosis. Pregnancy and delivery had been normal; there was no consanguinity or family history of neuromuscular disease. At age 4 1/2 months, she had generalized weakness, hypotonia, areflexia, and macroglossia. She developed cyanosis and respiratory failure, and marked cardiomegaly was noted. She died at age 8 1/2 months of cardiac arrest. Results from a muscle biopsy specimen obtained at age 4 1/2 months showed ragged-red fibers and increased glycogen and lipid droplets. With the cytochrome c oxidase reaction, only 5% of the fibers stained positively in the biopsy specimen. Cytochrome c oxidase activity was 7.3% of normal in muscle mitochondria and 12.2% of normal in heart mitochondria. Reduced-minus-oxidized cytochrome spectra showed lack of the cytochrome aa3 peak. Immunotitration using antibodies against purified human heart cytochrome c oxidase showed normal amount of cross-reacting material in both heart and muscle. The genetic error could have involved a cytochrome c oxidase isozyme common to heart and muscle.

Cytochrome-c Oxidase Deficiency↗
PubMed1986

Free amino acids in the striatum of mice infected with Venezuelan equine encephalomyelitis virus.

In mice inoculated with the Guajira strain of Venezuelan equine encephalomyelitis virus, a significant increase in the concentration of arginine, isoleucine, leucine, glycine, phenylalanine, serine, threonine, and valine was produced in the striatum. On the contrary, the levels of alanine, asparagine, aspartate, GABA, glutamine, and taurine were reduced. No changes were observed in the striatal content of tyrosine and glutamic acid.

Amino Acids↗
PubMed1986

Fatal infantile form of muscle phosphofructokinase deficiency.

We studied a girl with an infantile syndrome of limb weakness, seizures, cortical blindness, and corneal opacifications; she died at age 7 months of respiratory failure. There was no consanguinity or family history of neuromuscular diseases. Histochemical and biochemical studies of muscle showed mildly increased glycogen content and markedly decreased PFK activity (1.4% of the normal mean). Anaerobic glycolysis in vitro confirmed the metabolic block. Immunofluorescence and immunotitration by ELISA using monoclonal antibodies against subunit M of PFK showed a normal amount of cross-reacting material. The brain showed typical features of neuroaxonal dystrophy. This variant of PFK deficiency may be due to a distinct genetic defect.

Brain Diseases↗
PubMed1986

Huntington's disease in Venezuela: neurologic features and functional decline.

We studied 65 Huntington's disease patients and 225 at-risk individuals over the past 4 years. The rate of decline of these untreated patients from Venezuela was similar to that seen in US patients who had received neuroleptic drugs. Chorea, oculomotor dysfunction, and dysdiadochokinesis were early symptoms; parkinsonian features and dystonia came later. Juvenile patients declined nearly twice as fast as adult-onset patients. No distinctive neurologic phenotypes were seen in children of two affected parents.

Adult↗
PubMed1985

Fatal infantile mitochondrial myopathy and renal dysfunction caused by cytochrome c oxidase deficiency: immunological studies in a new patient.

A 3-month-old female infant had profound generalized weakness, de Toni-Fanconi-Debre syndrome, and lactic acidosis. She required assisted ventilation and died at the age of 8 months. Muscle biopsy showed accumulation of mitochondria, glycogen, and lipid droplets. Histochemical reaction and immunocytochemical stain for cytochrome c oxidase showed very weak results, but both reactions were normal in intrafusal fibers of the muscle spindle. In crude extracts of the patient's muscle, cytochrome c oxidase activity was undetectable and enzyme-linked immunosorbent assay showed decreased reaction at all dilutions of antiserum. These data indicate that the amount of immunoreactive enzyme protein is markedly decreased in muscle of patients with fatal infantile cytochrome c oxidase deficiency and renal dysfunction.

Biopsy↗