Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-0533
    Keywords: Mitochondrial encephalomyopathies ; Immunocytochemistry ; Histochemistry ; Mitochondrial deletions ; Cytochrome oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunocytochemical studies with a holocomplex antibody battery in patients with chronic progressive external ophthalmoplegia, with and without large mitochondrial DNA deletions, revealed positive (and often increased) immunoreactivity for all complexes studied in histochemically cytochrome oxidase (COX)-negative areas, suggesting a compensatory upregulation of these components. Similar findings were observed with subunit-specific probes directed against both nuclear- and mitochondrially encoded gene products. Comparison of staining intensities between the different complexes revealed significantly more variability in COX-negative than COX-positive fibres, suggesting disordered stoichiometric control during up-regulation. These differences were confirmed using statistical models. This data challenges the view that COX-negative fibre segments have little or no mitochondrially coded protein translation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-0533
    Keywords: Mitochondrial disease ; Myoclonus epilepsy and ragged red fibers (MERRF) syndrome ; Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome ; Polarographic studies ; Immunoblot studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mitochondrial respiratory chain function was investigated with polarographic and enzymatic studies, and correlated with immunoblot studies using a battery of probes against respiratory chain holocomplexes in a series of patients with myoclonus epilepsy and ragged red fibers (MERRF) syndrome. State III respiration rates in intact skeletal muscle mitochondria were normal in two cases, suggested site I deficiency in one case and a midrespiratory defect in another. Immunological studies of complex I showed reduced levels of several subunits with the apparent absence of two bands (which at 45 and 42 kDa, coincide with the predicted electrophoretic mobility of the ND5 gene product) in one case. Complex I, III and IV composition was normal in the other three cases indicating no major disruption of complex assembly. A differing severity of skeletal muscle respiratory chain impairment in a group of unrelated patients with severe cerebral clinical involvement is best explained by uneven tissue distribution between brain and muscle of a heteroplasmic mtDNA mutation. The relationship between MERRF and mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) encephalopathies is reappraised by extension of this hypothesis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A good standard reference for the highly polymorphic human mitochondrial DNA (mtDNA) sequence is essential for studies of normal and disease-related nucleotide variants in the mitochondrial genome. A consensus sequence for the human mitochondrial genome has been derived from thirteen unrelated mtDNA sequences. We report 128 nucleotide variants of the human mtDNA sequence, and 62 amino acid variants of the human mitochondrial translation products, observed in the coding region of these mtDNA sequences.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distributrion of the causal 8344A→G mtDNA mutation has been examined in six tissues of a patient with myoclonic epilepsy with ragged red fibers (MERRF), to study the developmental genetics of this type of mitochondrial disorder, and to determine the pathophysiological importance of the mtDNA heteroplasmy generally observed in such patients. Heteroplasmy of the mtDNA was observed in all six tissues (cerebellum, cerebrum, pancreas, liver, muscle, and heart) suggesting that, whereas the mtDNA mutation is relatively new, the mutated population must have existed before the formation of the three primary embryonic layers. The tissue distribution reveals significant variations in the ratio between the mutated and the normal mtDNA species, indicating the randomness of mtDNA segregation during developmental cell division and differentiation events. The result suggests the existence of tissue-specific nuclear factor(s) that determines the expression of the 8344A→G mutation in various tissues; in MERRF syndrome, expression is mainly in the central nervous system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inherited metabolic disease 17 (1994), S. 521-526 
    ISSN: 1573-2665
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pearson syndrome is a multisystem mitochondrial disorder of infancy that is associated with deletions in the mitochondrial DNA (mtDNA) genome. We report a study on a male infant with Pearson syndrome. Assessment of oxidative phosphorylation activity indicated combined respiratory-chain defects in muscle, liver and fibroblasts; in particular, activity of complex I was reduced. Analysis of the patient's mtDNA identified a novel heteroplasmic 2.461 kb deletion, present at levels greater than 50% of the total mtDNA in the tissues examined. The deletion spanned nucleotides 10368 to 12828 and was flanked by a 3 bp GCC direct repeat sequence. Gene sequences affected are subunits 3, 4, 4L and 5 of complex I, and tRNAs for arginine, histidine, serine and leucine. Our findings correlate with the multiorgan involvement observed in Pearson syndrome.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...