RESUMO
BACKGROUND: Lower habitual physical activity in adolescents with visual impairment (VI) have detrimental effect on their general health such as bone quality and physical fitness. The aim of this study was to demonstrate the bone quality in children with VI and to analyze the correlations of their bone characteristics with anthropometric and physical fitness tests. METHODS: The participants (N.=38) were adolescents (14.85±2.79 yrs) with low vision (N.=18) or blindness (N.=20). Dual-energy X-ray absorptiometry (DEXA) was used to measure bone mineral density (BMD), bone mineral content (BMC) of the total body and L1-L4 of the lumbar spinal region. After anthropometry physical fitness was examined by laboratory test (VÌO
Assuntos
Força da Mão , Baixa Visão , Absorciometria de Fóton , Adolescente , Composição Corporal , Densidade Óssea , Criança , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Aptidão Física , Baixa Visão/metabolismoRESUMO
Low-cost optical scattering particulate matter (PM) sensors report total or size-specific particle counts and mass concentrations. The PM concentration and size are estimated by the original equipment manufacturer (OEM) proprietary algorithms, which have inherent limitations since particle scattering depends on particles' properties such as size, shape, and complex index of refraction (CRI) as well as environmental parameters such as temperature and relative humidity (RH). As low-cost PM sensors are not able to resolve individual particles, there is a need to characterize and calibrate sensors' performance under a controlled environment. Here, we present improved calibration algorithms for Plantower PMS A003 sensor for mass indices and size-resolved number concentration. An aerosol chamber experimental protocol was used to evaluate sensor-to-sensor data reproducibility. The calibration was performed using four polydisperse test aerosols. The particle size distribution OEM calibration for PMS A003 sensor did not agree with the reference single particle sizer measurements. For the number concentration calibration, the linear model without adjusting for the aerosol properties and environmental conditions yields an absolute error (NMAE) of ~ 4.0% compared to the reference instrument. The calibration models adjusted for particle CRI and density account for non-linearity in the OEM's mass concentrations estimates with NMAE within 5.0%. The calibration algorithms developed in this study can be used in indoor air quality monitoring, occupational/industrial exposure assessments, or near-source monitoring scenarios where field calibration might be challenging.
Assuntos
Poluentes Atmosféricos/química , Material Particulado/química , Aerossóis/química , Poluição do Ar em Ambientes Fechados , Algoritmos , Calibragem , Ambiente Controlado , Monitoramento Ambiental , Humanos , Umidade , Modelos Lineares , Exposição Ocupacional , Tamanho da Partícula , Refratometria , Reprodutibilidade dos Testes , Temperatura , Baixa Visão/metabolismoRESUMO
Dominant optic atrophy (DOA) is a rare progressive and irreversible blinding disease which is one of the most frequent forms of hereditary optic neuropathy. DOA is mainly caused by dominant mutation in the OPA1 gene encoding a large mitochondrial GTPase with crucial roles in membrane dynamics and cell survival. Hereditary optic neuropathies are commonly characterized by the degeneration of retinal ganglion cells, leading to the optic nerve atrophy and the progressive loss of visual acuity. Up to now, despite increasing advances in the understanding of the pathological mechanisms, DOA remains intractable. Here, we tested the efficiency of gene therapy on a genetically-modified mouse model reproducing DOA vision loss. We performed intravitreal injections of an Adeno-Associated Virus carrying the human OPA1 cDNA under the control of the cytomegalovirus promotor. Our results provide the first evidence that gene therapy is efficient on a mouse model of DOA as the wild-type OPA1 expression is able to alleviate the OPA1-induced retinal ganglion cell degeneration, the hallmark of the disease. These results displayed encouraging effects of gene therapy for Dominant Optic Atrophy, fostering future investigations aiming at clinical trials in patients.
Assuntos
GTP Fosfo-Hidrolases/genética , Terapia Genética/métodos , Mitocôndrias/genética , Atrofia Óptica Autossômica Dominante/terapia , Células Ganglionares da Retina/metabolismo , Baixa Visão/terapia , Animais , Morte Celular , Citomegalovirus/genética , Citomegalovirus/metabolismo , Dependovirus/genética , Dependovirus/metabolismo , Modelos Animais de Doenças , Feminino , GTP Fosfo-Hidrolases/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Injeções Intravítreas , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Mutação , Atrofia Óptica Autossômica Dominante/genética , Atrofia Óptica Autossômica Dominante/metabolismo , Atrofia Óptica Autossômica Dominante/patologia , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Regiões Promotoras Genéticas , Células Ganglionares da Retina/patologia , Transgenes , Baixa Visão/genética , Baixa Visão/metabolismo , Baixa Visão/patologiaRESUMO
PURPOSE: To investigate whether there are differences in retinal oxygen saturation in upper and lower visual field hemispheres in primary open-angle glaucoma (POAG) and in normal-tension glaucoma (NTG). METHODS: This study enrolled POAG and NTG patients exhibiting differences between the upper and lower total deviation (TD) that were either more than 10 or <5 dB. Retinal oxygen saturation measurements in these patients with glaucoma were performed by a non-invasive spectrophotometric retinal oximeter. The Student's t-test was used for statistical analysis. RESULTS: Evaluations of the worse and better hemifields in the patients with POAG who exhibited differences in the upper and lower hemifield TD that was <5 dB (n = 25) showed that there were no statistically significant differences for the retinal venous saturation of oxygen (SaO2 ). However, there was a higher mean SaO2 in the worse (57.0 ± 7.5%) versus the better (54.3 ± 7.0%) hemifield in the patients with NTG (n = 22; p = 0.007). Evaluations of the patients with more than a 10-dB difference in the upper and lower hemifield TD showed statistically significant differences for the retinal venous SaO2 in the venous vessels between the POAG (n = 19) and the NTG (n = 26) patients. CONCLUSION: Although there was no significant difference in retinal SaO2 in the venules between the better and worse hemifield when the difference between the better and worse hemifield in the patients with POAG was <5 dB, there was a higher SaO2 in the venous vessels in the worse hemifield in the patients with NTG.
Assuntos
Glaucoma de Ângulo Aberto/metabolismo , Pressão Intraocular/fisiologia , Glaucoma de Baixa Tensão/metabolismo , Consumo de Oxigênio/fisiologia , Oxigênio/metabolismo , Veia Retiniana/fisiopatologia , Baixa Visão/etiologia , Feminino , Glaucoma de Ângulo Aberto/complicações , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Glaucoma de Baixa Tensão/complicações , Glaucoma de Baixa Tensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Oximetria , Retina/metabolismo , Retina/fisiopatologia , Estudos Retrospectivos , Espectrofotometria , Baixa Visão/metabolismo , Baixa Visão/fisiopatologia , Campos Visuais/fisiologiaRESUMO
CASO CLÍNICO: Mujer de 27 años que presentaba disminución de visión en ojo derecho (20/200). El examen funduscópico reveló una hemorragia intrarretiniana macular con desprendimiento neurosensorial en ojo derecho, y un depósito de material viteliforme en el ojo izquierdo. La angiografía fluoresceínica y el electrooculograma confirmaron el diagnóstico de neovascularización coroidea asociada a enfermedad de Best. Cuatro semanas después de una única inyección de bevacizumab intravítreo, la agudeza visual a la normalidad (20/25) y se mantuvo estable tras 12 meses de seguimiento. DISCUSIÓN: El bevacizumab intravítreo puede ser una opción terapéutica eficaz en la neovascularización coroidea secundaria a enfermedad de Best
CASE REPORT: A 27-year old woman presented with loss of vision in the right eye (20/200). Ophthalmoscopic examination showed intrarretinal hemorrhage in the macular region with neurosensory detachment in the right eye, and viteliform deposit on the left eye. Fluorescein angiography and the electrooculogram confirmed the diagnosis of choroidal neovascularization associated with Best's disease. Four weeks after a single bevacizumab intravitreal injection, visual acuity was restored (20/25) and remained stable after a 12 month follow-up. DISCUSSION: Intravitreal bevacizumab appears to be an effective treatment for choroidal neovascularization associated to Best's disease
Assuntos
Humanos , Feminino , Baixa Visão/complicações , Baixa Visão/metabolismo , Hemorragia Retiniana/diagnóstico , Baixa Visão/diagnóstico , Baixa Visão/genética , Baixa Visão/patologia , Hemorragia Retiniana/complicaçõesRESUMO
The cone cyclic nucleotide-gated (CNG) channel is essential for central and color vision and visual acuity. This channel is composed of two structurally related subunits, CNGA3 and CNGB3; CNGA3 is the ion-conducting subunit, whereas CNGB3 is a modulatory subunit. Mutations in both subunits are associated with achromatopsia and progressive cone dystrophy, with mutations in CNGB3 alone accounting for 50% of all known cases of achromatopsia. However, the molecular mechanisms underlying cone diseases that result from CNGB3 deficiency are unknown. This study investigated the role of CNGB3 in cones, using CNGB3(-/-) mice. Cone dysfunction was apparent at the earliest time point examined (post-natal day 30) in CNGB3(-/-) mice. When compared with wild-type (WT) controls: photopic electroretingraphic (ERG) responses were decreased by approximately 75%, whereas scotopic ERG responses were unchanged; visual acuity was decreased by approximately 20%, whereas contrast sensitivity was unchanged; cone density was reduced by approximately 40%; photoreceptor apoptosis was detected; and outer segment disorganization was observed in some cones. Notably, CNGA3 protein and mRNA levels were significantly decreased in CNGB3(-/-) mice; in contrast, mRNA levels of S-opsin, Gnat2 and Pde6c were unchanged, relative to WT mice. Hence, we show that loss of CNGB3 reduces biosynthesis of CNGA3 and impairs cone CNG channel function. We suggest that down-regulation of CNGA3 contributes to the pathogenic mechanism by which CNGB3 mutations lead to human cone disease.
Assuntos
Canais de Cátion Regulados por Nucleotídeos Cíclicos/deficiência , Degeneração Neural/genética , Células Fotorreceptoras Retinianas Cones/metabolismo , Baixa Visão/genética , Animais , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Regulação para Baixo , Humanos , Camundongos , Camundongos Knockout , Mutação , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Biossíntese de Proteínas/genética , Células Fotorreceptoras Retinianas Cones/patologia , Baixa Visão/metabolismo , Baixa Visão/patologiaAssuntos
Doenças dos Gânglios da Base/fisiopatologia , Predisposição Genética para Doença/genética , Doenças Mitocondriais/diagnóstico , Síndrome das Pernas Inquietas/diagnóstico , Baixa Visão/diagnóstico , Doenças dos Gânglios da Base/diagnóstico por imagem , Doenças dos Gânglios da Base/genética , Blefaroptose/etiologia , Blefaroptose/metabolismo , Blefaroptose/fisiopatologia , Análise Mutacional de DNA , DNA Polimerase gama , DNA Polimerase Dirigida por DNA/genética , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/metabolismo , Transtornos de Deglutição/fisiopatologia , Diagnóstico Diferencial , Dopamina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/deficiência , Feminino , Humanos , Padrões de Herança/genética , Pessoa de Meia-Idade , Doenças Mitocondriais/complicações , Doenças Mitocondriais/metabolismo , Debilidade Muscular/etiologia , Debilidade Muscular/metabolismo , Debilidade Muscular/fisiopatologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Mutação/genética , Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/metabolismo , Transtornos da Motilidade Ocular/fisiopatologia , Putamen/diagnóstico por imagem , Putamen/metabolismo , Putamen/fisiopatologia , Cintilografia , Síndrome das Pernas Inquietas/etiologia , Síndrome das Pernas Inquietas/metabolismo , Baixa Visão/etiologia , Baixa Visão/metabolismoRESUMO
Blurred vision and cognitive difficulties are prominent symptoms during acute insulin-induced hypoglycemia. Our hypothesis was that changes in cerebral activity reflect these symptoms. Positron emission tomography (PET) with oxygen-15-labelled water was used to measure relative changes in regional cerebral blood flow (rCBF) as a marker of cerebral activity. Hypoglycemia was induced by intravenous insulin infusion in 19 healthy men performing two different cognitive tasks of varying complexity. The hypoglycemic stimulus [plasma glucose 2.2 mmol/liter (0.4)] produced a significant hormonal counterregulatory response. During the low cognitive load, rCBF decreased in response to hypoglycemia in a large bilateral area in the posterior part of the temporal lobe, and rCBF increased bilaterally in the anterior cingulate gyrus, the right frontal gyrus, the fusiform gyrus, thalamus, and the left inferior part of the frontal gyrus. During the high cognitive load, rCBF decreased bilaterally in a large region in the posterior part of the temporal gyrus and increased in the left and right anterior cingulate gyrus, left and right frontal gyrus, right parahippocampal and lingual gyrus, and left superior temporal gyrus. Visual impairment during hypoglycemia was associated with deactivation in the ventral visual stream. The anterior cingulate gyrus was activated during hypoglycemia in a load-dependent manner. Areas on the frontal convexity were differentially activated in response to the cognitive load during hypoglycemia. Our findings suggest that hypoglycemia induces changes in sensory processing in a cognition-independent manner, whereas activation of areas of higher order functions is influenced by cognitive load as well as hypoglycemia.
Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/fisiopatologia , Hipoglicemia/diagnóstico por imagem , Hipoglicemia/fisiopatologia , Adulto , Mapeamento Encefálico/métodos , Córtex Cerebral/metabolismo , Circulação Cerebrovascular/fisiologia , Cognição/fisiologia , Transtornos Cognitivos/etiologia , Lateralidade Funcional/fisiologia , Glucose/metabolismo , Humanos , Hipoglicemia/complicações , Insulina/farmacologia , Masculino , Processos Mentais/fisiologia , Testes Neuropsicológicos , Radioisótopos de Oxigênio , Percepção/fisiologia , Tomografia por Emissão de Pósitrons/métodos , Baixa Visão/diagnóstico por imagem , Baixa Visão/metabolismo , Baixa Visão/fisiopatologia , Vias Visuais/diagnóstico por imagem , Vias Visuais/metabolismo , Vias Visuais/fisiopatologia , Adulto JovemRESUMO
Juvenile neuronal ceroid lipofuscinosis (JNCL) is an autosomal recessive disorder of childhood caused by mutations in CLN3. Although visual deterioration is typically the first clinical sign to manifest in affected children, loss of Cln3 in a mouse model of JNCL does not recapitulate this retinal deterioration. This suggests that either the loss of CLN3 does not directly affect retinal cell survival or that nuclei involved in visual processing are affected prior to retinal degeneration. Having previously demonstrated that Cln3(-/-) mice have decreased optic nerve axonal density, we now demonstrate a decrease in nerve conduction. Examination of retino-recipient regions revealed a decreased number of neurons within the dorsal lateral geniculate nucleus (LGNd). We demonstrate decreased transport of amino acids from the retina to the LGN, suggesting an impediment in communication between the retina and projection nuclei. This study defines a novel path of degeneration within the LGNd, providing a mechanism for causation of JNCL visual deficits.