Navegando por Palavras-chave "Leber hereditary optic neuropathy"
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- ItemSomente MetadadadosOptic nerve histopathology in a case of Wolfram Syndrome: A mitochondrial pattern of axonal loss(Elsevier B.V., 2013-11-01) Ross-Cisneros, Fred N.; Pan, Billy X.; Silva, Ruwan A.; Miller, Neil R.; Albini, Thomas A.; Tranebjaerg, Lisbeth; Rendtorff, Nanna D.; Lodahl, Marianne; Moraes-Filho, Milton N.; Moraes, Milton N.; Salomão, Solange Rios [UNIFESP]; Berezovsky, Adriana [UNIFESP]; Belfort, Rubens [UNIFESP]; Carelli, Valerio; Sadun, Alfredo A.; Univ So Calif; Univ Miami; Johns Hopkins Sch Med; Bispebjerg Hosp; Univ Copenhagen; Inst Olhos Colatina; Universidade Federal de São Paulo (UNIFESP); Univ Bologna; IRCCS Ist Sci NeurolMitochondrial dysfunction in Wolfram Syndrome (WS) is controversial and optic neuropathy, a cardinal clinical manifestation, is poorly characterized. We here describe the histopathological features in postmortem retinas and optic nerves (ONs) from one patient with WS, testing the hypothesis that mitochondrial dysfunction underlies the pathology. Eyes and retrobulbar ONs were obtained at autopsy from a WS patient, and compared with those of a Leber hereditary optic neuropathy (LHON) patient and one healthy control. Retinas were stained with hematoxylin & eosin for general morphology and ONs were immunostained for myelin basic protein (MBP). Immunostained ONs were examined in four quadrants: superior, inferior, nasal, and temporal. the WS retinas displayed a severe loss of retinal ganglion cells in the macular region similar to the LHON retina, but not in the control. the WS ONs, immunostained for MBP, revealed a zone of degeneration in the temporal and inferior quadrants. This pattern was similar to that seen in the LHON ONs but not in the control. Thus, the WS patient displayed a distinct pattern of optic atrophy observed bilaterally in the temporal and inferior quadrants of the ONs. This arrangement of axonal degeneration, involving primarily the papillomacular bundle, closely resembled LHON and other mitochondrial optic neuropathies, supporting that mitochondrial dysfunction underlies its pathogenesis. (C) 2013 Elsevier B.V. and Mitochondria Research Society. All rights reserved.
- ItemSomente MetadadadosRetinal nerve fiber layer thickness variability in Leber hereditary optic neuropathy carriers(Wichtig Editore, 2012-11-01) Barboni, Piero; Savini, Giacomo; Feuer, William J.; Budenz, Donald L.; Carbonelli, Michele; Chicani, Filipe [UNIFESP]; Ramos, Carolina do Val Ferreira [UNIFESP]; Salomão, Solange Rios [UNIFESP]; De Negri, Annamaria; Parisi, Vincenzo; Carelli, Valerio; Sadun, Alfredo A.; Studio Oculist dAzeglio; Univ Bologna; IRCCS; Univ Miami; Univ So Calif; Universidade Federal de São Paulo (UNIFESP); Azienda San Camillo ForlaniniPURPOSE. Recent investigations suggested that unaffected carriers of Leber hereditary optic neuropathy (LHON) may show subclinical visual alterations. Structural changes have also been detected by optical coherence tomography (007), which revealed a temporal thickening of the retinal nerve fiber layer (RNFL). These changes may reflect compensatory effects such as mitochondria accumulation within the RNFL axons. This study aimed to investigate whether the RNFL of LHON carriers shows greater than expected thickness variations, which may reflect transient subclinical changes, over the course of years.METHODS. Using Stratus OCT, the RNFL thickness was measured yearly from 2005 to 2008 in 24 Brazilian LHON carriers, all with homoplasmic 11778/ND4 mtDNA mutation. An Italian sample of 20 healthy subjects served as a control. Data were compared also to a previously published sample (n=59) of glaucomatous eyes.RESULTS. the LHON carriers showed test-retest standard deviations that were larger than normal controls in the temporal (p=0.004), superior (p<0.0001), and inferior quadrants (p=0.019). Compared to the glaucoma cases, no statistical differences were observed.CONCLUSIONS. the RNFL thickness in LHON carriers, when measured at different time points, has higher variability than in normal subjects. Transitory RNFL swelling may be caused either by compensatory mechanisms (increased mitochondrial biogenesis) or by axonal stasis preceding decompensation of retinal ganglion cells. in both situations, these changes may represent the origin of the visual alterations previously detected in LHON carriers. Alternatively, increased variability of RNFL thickness may be influenced by the LHON microangiopathy, as retinal blood vessels contribute to the OCT RNFL thickness measurements.
- ItemSomente MetadadadosVisual evoked potentials findings in non-affected subjects from a large Brazilian pedigree of 11778 Leber's hereditary optic neuropathy(Springer, 2010-10-01) Sacai, Paula Yuri [UNIFESP]; Salomão, Solange Rios [UNIFESP]; Carelli, Valerio; Pereira, Josenilson Martins [UNIFESP]; Belfort, Rubens [UNIFESP]; Sadun, Alfredo Arrigo; Berezovsky, Adriana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Bologna; Keck Univ So CalifTo investigate pattern-reversal visual evoked potentials (PRVEP) in asymptomatic maternally and non-maternally related members from a large Brazilian 11778/ND4 LHON pedigree. Transient PRVEP for check sizes 15' and 60' were recorded from asymptomatic mutation carriers and non-mutant descendants of affected/non-affected males, all with best-corrected visual acuity of 20/20. A control group of spouses (off-pedigree) was also included. Parameters of N75, P100 and N135 latencies (ms) and N75-P100 peak-to-peak amplitude (mu V) as well as temporal dispersion (latency of N135-latency of N75) were determined. Longitudinal testing was obtained in a subseries of carriers in three annual consecutive visits. We tested 48 asymptomatic mutation carriers, 19 descendants of affected males, 9 descendants of non-affected males and 27 off-pedigrees, all of the latter being non-mutant. All non-mutant male descendants did not differ from off-pedigree controls. Statistically prolonged P100 latencies were found in mutation carriers (P = 0.0143) when compared with off-pedigrees for check sizes 15', as well as significantly larger temporal dispersions for both check size 15' (P = 0.0012) and check size 60' (P = 0.0271). Serial testing in 15 mutation carriers disclosed prolonged P100 latencies and larger temporal dispersion that did not change over time. Subclinical PRVEP abnormalities were detected in this large group of asymptomatic carriers of the 11778/ND4 LHON mutation from the same family, confirming and extending previous psychophysical and structural findings of a selective involvement of the parvocellular pathway. PRVEP is a useful test to characterize and monitor visual dysfunction in this devastating disease.