2,119 research outputs found
Association of the mtDNA m.4171C>A/MT-ND1 mutation with both optic neuropathy and bilateral brainstem lesions
No full textBackground: An increasing number of mitochondrial DNA (mtDNA) mutations, mainly in complex I genes, have
been associated with variably overlapping phenotypes of Leber’s hereditary optic neuropathy (LHON),
mitochondrial encephalomyopathy with stroke-like episodes (MELAS) and Leigh syndrome (LS). We here describe
the first case in which the m.4171C>A/MT-ND1 mutation, previously reported only in association with LHON, leads
also to a Leigh-like phenotype.
Case presentation: A 16-year-old male suffered subacute visual loss and recurrent vomiting and vertigo associated
with bilateral brainstem lesions affecting the vestibular nuclei. His mother and one sister also presented subacute
visual loss compatible with LHON. Sequencing of the entire mtDNA revealed the homoplasmic m.4171C>A/MT-ND1
mutation, previously associated with pure LHON, on a haplogroup H background. Three additional non-synonymous
homoplasmic transitions affecting ND2 (m.4705T>C/MT-ND2 and m.5263C>T/MT-ND2) and ND6 (m.14180T>C/MT-ND6)
subunits, well recognized as polymorphisms in other mtDNA haplogroups but never found on the haplogroup H
background, were also present.
Conclusion: This case widens the phenotypic expression of the rare m.4171C>A/MT-ND1 LHON mutation, which
may also lead to Leigh-like brainstem lesions, and indicates that the co-occurrence of other ND non-synonymous
variants, found outside of their usual mtDNA backgrounds, may have increased the pathogenic potential of the
primary LHON mutation
Implications of mitochondrial DNA mutations in human induced pluripotent stem cells
No full textIndividual cells in the same induced pluripotent stem cell (iPSC)-derived clones can exhibit large heterogeneity. In this Comment, Carelli et al. discuss emerging evidence implicating variants in mitochondrial DNA, and highlight the need for routine screening of iPSCs.Single-cell analyses in recent years have shown major differences in the transcriptome between individual cells in the same induced pluripotent stem cell-derived clones. Although these differences are in part attributable to genetic and epigenetic modifications of the nuclear genome, emerging evidence suggests that variants in mitochondrial DNA also play a pivotal role
Dominance in mitochondrial disorders.
No full textDominant traits are rare in mitochondrial disorders but include important nosological entities such as alterations of organellar biogenesis and abnormalities in the structural integrity of the mitochondrial genome, determined by mutations in genes involved in its maintenance and propagation. Both haplo-insufficiency and 'gain-of-function' mechanisms underlie the pathogenesis of these disorders. Impairment in energy supply, abnormal mitochondrial trafficking, increased toxic damage by oxygen radicals, and mitochondrially driven apoptosis have been documented in different dominant syndromes. In addition, maternally inherited mutations of mitochondrial DNA can sometimes simulate dominant traits, mainly because of reduced penetrance and complex interaction with genetic and environmental factors. © SSIEM and Springer 2005
Mitochondrial disorders.
No full textPURPOSE OF REVIEW: Mitochondrial disorders are increasingly acknowledged as a major category in clinical neurology. In this review we highlight the most recent advances in the field, including the characterization of new disease genes, new physiopathological insights, and the role of mitochondrial dysfunction in neurodegeneration. RECENT FINDINGS: Substantial progress has been made on the genetic basis and pathogenic mechanisms in disorders associated with altered mitochondrial DNA stability and expression. These defects include a wide spectrum of neurological conditions caused by genetic abnormalities of the mitochondrial replication and translation machineries, and of the metabolic pathways controlling the nucleotide supply to organelles, cells and tissues. Another relevant contribution has been given to the molecular dissection of coenzyme Q deficiency, a clinically heterogeneous, potentially treatable condition, thanks to the biochemical and genetic characterization of the first defects in coenzyme Q biosynthesis. Finally, the genetic determinants controlling the penetrance of mitochondrial disorders, as well as the role of mitochondrial dysfunction in neurodegenerative conditions such as Parkinson's and Huntington's diseases, have been investigated in both patients and animal models. SUMMARY: The dual genetic contribution controlling mitochondrial biogenesis, and the intricacy and universality of the metabolic pathways operating in the mitochondrion explain the complexity of what is now known as 'mitochondrial medicine'. © 2007 Lippincott Williams & Wilkins, Inc
Strategie di discorso sull’immigrazione: analisi delle pagine Facebook di candidati e liste
No full textIl saggio affronta le strategie di comunicazione Facebook di candidati e liste sul tema dell'immigrazione in occasione delle elezioni regionali 2018 in Lazio e Lombardi
Immigrazione e strategie di coverage della stampa locale
No full textIl saggio affronta un'analisi della copertura della stampa locale di Lombardia e Lazio sul tema dell'immigrazione nella campagna elettorale per le regionali 201
"Quasi gol". Per una storia del rapporto tra sport e televisione in Italia
No full textIl contributo si propone di tracciare una linea evolutiva dei processi mediali e culturali relativi al rapporto tra sport e televisione in Italia, in relazione ai modelli di rappresentazione, alle pratiche produttive, alle trasformazioni e influenze tra i due ambit
Quando la Tv incontra la rete: la Social TV
No full textIl saggio affronta il fenomeno della social Tv da una prospettiva teorica e soffermandosi sui principali modelli di rilevazione e relative metriche. Conclude il saggio un confronto tra case histories di prodotti televisivi del contesto italiano
Mitochondrial retinopathies
No full textThe retina is an exquisite target for defects of oxidative phosphorylation (OXPHOS) associated with mitochondrial impairment. Retinal involvement occurs in two ways, retinal dystrophy (retinitis pigmentosa) and subacute or chronic optic atrophy, which are the most common clinical entities. Both can present as isolated or virtually exclusive conditions, or as part of more com-plex, frequently multisystem syndromes. In most cases, mutations of mtDNA have been found in association with mitochondrial retinopathy. The main genetic abnormalities of mtDNA include mutations associated with neurogenic muscle weakness, ataxia and retinitis pigmentosa (NARP) sometimes with earlier onset and increased severity (maternally inherited Leigh syndrome, MILS), single large-scale deletions determining Kearns–Sayre syndrome (KSS, of which retinal dystrophy is a cardinal symptom), and mutations, particularly in mtDNA-encoded ND genes, associated with Leber hereditary optic neuropathy (LHON). However, mutations in nuclear genes can also cause mito-chondrial retinopathy, including autosomal recessive phenocopies of LHON, and slowly progressive optic atrophy caused by dominant or, more rarely, recessive, mutations in the fusion/mitochondrial shaping protein OPA1, encoded by a nuclear gene on chromosome 3q29
I broadcasters in Italia: organizzazione e professioni
No full textIl saggio effettua una ricognizione dei differenti modelli di organizzazione aziendale e professionale dei principali broadcasters e players del settore televisivo presenti nel mercato italiano
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