Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Functional respiratory chain studies in mitochondrial cytopathies. Support for mitochondrial DNA heteroplasmy in myoclonus epilepsy and ragged red fibers (MERRF) syndrome (1991)
    Springer
    Acta neuropathologica 81 (1991), S. 318-323 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Mitochondrial disease ; Myoclonus epilepsy and ragged red fibers (MERRF) syndrome ; Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome ; Polarographic studies ; Immunoblot studies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305874
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Chronic progressive external ophthalmoplegia in patients with large heteroplasmic mitochondrial DNA deletions: an immunocytochemical study (1991)
    Springer
    Acta neuropathologica 82 (1991), S. 185-192 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Mitochondrial encephalomyopathies ; Immunocytochemistry ; Histochemistry ; Mitochondrial deletions ; Cytochrome oxidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00294444
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Normal variants of human mitochondrial DNA and translation products: the building of a reference data base (1991)
    Springer
    Human genetics 〈Berlin〉 88 (1991), S. 139-145 
    Details
    ISSN: 1432-1203
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00206061
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Tissue segregation of a heteroplasmic mtDNA mutation in MERRF (Myoclonic epilepsy with ragged red fibers) encephalomyopathy (1992)
    Springer
    Human genetics 〈Berlin〉 90 (1992), S. 251-254 
    Details
    ISSN: 1432-1203
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220072
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Microphotometric analysis of NADH-tetrazolium reductase deficiency in fibroblasts of patients with Leber hereditary optic neuropathy (2000)
    Springer
    Journal of inherited metabolic disease 23 (2000), S. 730-744 
    Details
    ISSN: 1573-2665
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We employed a microphotometric approach to examine whether a defect in the mitochondrial respiratory complex I expected in Leber hereditary optic neuropathy (LHON) as the consequence of a mtDNA (11778G〉A) mutation in the ND4 gene coding for a subunit of the respiratory complex I can be detected at the single-cell level. Genetically stable fibroblast cell lines were established from skin biopsies of two members of a Chinese Indonesian family with LHON. The fibroblasts were homoplasmic for the 11778G〉A mutation. The activity of the respiratory complex I was examined histochemically by staining for NADH-tetrazolium reductase. The histochemical staining showed a typical pattern with an apparent concentration of the activity around the nucleus, suggested as the reflection of the gradient in the thickness of the unsectioned fibroblast cells. Microphotometric quantification of the staining intensity showed that the activity is linear for at least 60min. The activity shows a discontinuity in its Arrhenius kinetics with a break point at 13.0–13.5°C (activation energy at 50–58 J/mol and 209–238 J/mol above and below the break temperature, respectively), indicating the membrane association of the NADH-tetrazolium reductase activity. Both patients showed lower fibroblast NADH-tetrazolium reductase activity, with a reduction of ∼30%. Our results demonstrate the utility of microphotometric analysis in the study of biochemical defects associated with mutations in the mtDNA.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005687031531
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    A novel mtDNA deletion in an infant with Pearson syndrome (1994)
    Springer
    Journal of inherited metabolic disease 17 (1994), S. 521-526 
    Details
    ISSN: 1573-2665
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00711584
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...