941 resultados para Eye Diseases and defects
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Pós-graduação em Cirurgia Veterinária - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Bases Gerais da Cirurgia - FMB
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Pós-graduação em Bases Gerais da Cirurgia - FMB
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RESUMO: A retina é composta, entre outras estruturas, pelo epitélio pigmentar da retina (EPR)e pela coróide. A região central da retina denomina-se mácula, e é a zona mais afetada na degenerescência macular relacionada com a idade, a forma mais comum de degenerescência da retina. Nesta doença, a secreção de fatores de crescimento pelo EPR é afetada, nomeadamente a do fator de crescimento vascular endotelial (VEGF), e pouco se sabe ainda sobre os mecanismos moleculares conducentes a esta condição. A família de proteínas Rab GTPases está envolvida nas vias intracelulares de sinalização e tráfego membranares, essenciais na transdução de sinais extracelulares em respostas biológicas. A sua crucial importância nestes mecanismos levou-nos a considerar o seu potencial envolvimento nas vias de secreção do VEGF, e a questionar-nos se teriam algum papel regulador sobre as mesmas. O principal objetivo deste trabalho é identificar Rab GTPases importantes para as vias de secreção e endocitose do VEGF no EPR. Essa identificação ajudará a esclarecer a patogénese da degenerescência macular da retina, e poderá servir para uma procura mais direcionada de novos agentes terapêuticos. A caracterização de dois modelos in vitro do EPR, células primárias isoladas de murganho e a linha celular B6-RPE07,levou-nos a concluir que são ambos semelhantes. Contudo, a linha celular foi escolhida como protótipo do EPR por permitir o acesso a um número ilimitado de células. No decurso deste trabalho, desenvolvemos e caracterizámos uma biblioteca de ferramentas moleculares que nos permitiram reduzir os níveis proteicos das proteínas Rab GTPases, com base na tecnologia de ácido ribonucleico (ARN) de interferência. O papel das proteínas Rab GTPases na secreção do VEGF no EPR foi estudado com base no silenciamento de apenas uma proteína, ou combinando várias, segundo a sua localização e funções intracelulares descritas. Este trabalho permitiu-nos concluir que as proteínas Rab GTPases são importantes intervenientes no processo de secreção de VEGF pelo EPR, e confirmar dados anteriores que relatam o envolvimento de algumas Rab GTPases endocíticas no processo. Propomos ainda um novo modelo para a interação destas proteínas no EPR, e sugerimos que a Rab10 e a Rab14 atuam negativamente sobre a Rab8, controlando o seu funcionamento. Os nossos resultados evidenciam a importância das proteínas Rab GTPases na secreção do VEGF pelas células do EPR, e servem de base a futuros estudos que melhor procurem compreender este mecanismo e de que modo a sua alteração se relaciona com a degenerescência da retina.--------ABSTRACT: Retinal pigment epithelium (RPE) and choroid are components of the mammalian retina, of which the central region is called macula. The most common form of retinaldegeneration, age-related macular degeneration (AMD), involves primarily deregulation of growth factors secretion by the RPE. Very little is known about the molecular mechanisms that lead to impairment of RPE’s homeostatic intracellular processes, namely the secretion of vascular endothelial growth factor (VEGF). Rab GTPases’ family regulates membrane targeting and traffic, being essential in the transduction of signal pathways. Given Rab proteins’ role in intracellular trafficking, we propose to identify key regulatory Rab proteins involved in either the secretory or the recycling pathways of VEGF in RPE. Understanding how Rab proteins’ function disruption could lead to retinal and choroidal pathology would ultimately contribute to find new therapeutic agents. Here, we characterized two mouse RPE in vitro cell models, primary cells and B6-RPE07 cell line, and concluded that both display important epithelial features as the RPE presents in vivo. Considering unlimited cell number and results reproducibility, we chose B6-RPE07 cells to further study Rab proteins’ function. To scrutinize the consequences of Rab proteins’ absence or diminished levels, we have developed novel molecular tools to achieve silencing of these key proteins using miRNA technology. We further addressed the effect of Rab proteins’ absence on VEGF secretion by performing an extensive screening where different Rab proteins were silenced, both individually and in multiple combinations considering their cellular/ compartment location. We conclude that Rab GTPases are important intervenients in VEGF secretion by RPE cells, confirming endocytic Rab proteins’ role in regulation of VEGF biology. We also propose a novel model for Rab proteins’ interaction in RPE. Our results suggest that Rab10 and Rab14 might influence Rab8 in a negative feedback mechanism, important for controlling VEGF secretion. Our achievements’ unravel Rab proteins’ role in VEGF secretion by RPE cells and are the basis for future studies to better understand RPE molecular secretory machinery.
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Abstract Background: The epidemiological profile of mortality in a population is important for the institution of measures to improve health care and reduce mortality Objective: To estimate mortality rates and the proportional mortality from cardiovascular diseases and malformations of the circulatory system in children and adolescents. Methods: This is a descriptive study of mortality from cardiovascular diseases, malformations of the circulatory system, from all causes, ill-defined causes and external causes in children and adolescents in the state of Rio de Janeiro from 1996 to 2012. Populations were obtained from the Brazilian Institute of Geography and Statistics (Instituto Brasileiro de Geografia e Estatística - IBGE) and deaths obtained from the Department of Informatics of the Unified Health System (DATASUS)/Ministry of Health. Results: There were 115,728 deaths from all causes, 69,757 in males. The annual mortality from cardiovascular diseases was 2.7/100,000 in men and 2.6/100,000 in women. The annual mortality from malformations of the circulatory system was 7.5/100,000 in men and 6.6/100,000 in women. Among the specific causes of circulatory diseases, cardiomyopathies had the highest rates of annual proportional mortality, and from malformations of the circulatory system, it occurred due to unspecified malformations of the circulatory system, at all ages and in both genders. Conclusion: Mortality from malformations of the circulatory system was most striking in the first years of life, while cardiovascular diseases were more relevant in adolescents. Low access to prenatal diagnosis or at birth probably prevented the proper treatment of malformations of the circulatory system.
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Les résultats préliminaires de trois essais cliniques de thérapie génique d'une forme agressive de rétinite pigmentaire (l'amaurose congénitale de Leber) ont prouvé que le traitement des maladies dégénératives de la rétine par transfert de gène peut être sûr et efficace pour rétablir une fonction visuelle. Il faudra encore attendre les résultats à long terme de ces études pour que soit définitivement validée cette approche thérapeutique. Dans l'intervalle, il importe de se préparer à son introduction en ophtalmologie de façon à la rendre accessible à nos malades. Pratiquement cela revient à promouvoir: 1) le recrutement; 2) la caractérisation du phénotype et du génotype des sujets atteints et 3) la constitution d'un registre des rétinopathies héréditaires. Recently, preliminary results of three clinical gene therapy trials for early onset retinitis pigmentosa--Leber congenital amaurosis--suggested that treating this degenerative retinal disease by gene transfection can be safe and efficient to restore a visual function. The definitive validation of this therapeutic approach depends on the long-term results. The forthcoming availability of gene therapy in ophthalmology prompts the implementation: of 1) recruitment, 2) phenotyping and genotyping of affected patients, 3) and creation of a hereditary retinopathy registry.
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L’apoptosi és un procés fisiològic que controla el nombre de cèl·lules en organismes superiors. L’apoptosi està estrictament regulada i s’ha vist que està implicada en la patogènesi d’algunes malalties del sistema nerviós. En aquest sentit, un excés de mort cel·lular contribueix a les malalties neurodegenerati- ves, mentre que, el seu dèficit és una de les raons del desenvolupament de tumors. El punt principal de regulació del procés apoptòtic és l’activació de les caspases, cisteïna-proteases que tenen especificitat pels residus aspàrtic. Les caspases es poden activar per dos mecanismes principals: (1) alliberament de citocrom C dels mitocondris alterats al citoplasma i (2) l’activació dels receptors de la membrana anomenats receptors de mort (DR, de l’anglès death receptor). Aquests receptors s’han caracteritzat extensament en el sistema immunitari, mentre que en el sistema nerviós les seves funcions són encara desconegudes. El present article se centra en el paper dels DR en la patogènesi de malalties neurodegeneratives i suggereix el seu potencial des del punt de vista terapèutic. També es descriuen diverses molècules intracel·lulars caracteritzades per la seva habilitat en la modulació dels DR. Entre elles, presentem dues noves proteïnes – lifeguard i FAIM – que s’expressen específicament al sistema nerviós.
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Objectif: Évaluer les défis de la mobilité chez les personnes âgées atteintes de dégénérescence maculaire reliée à l’âge (DMLA), de glaucome ou de dystrophie cornéenne de Fuchs et les comparer avec les personnes âgées n’ayant pas de maladie oculaire. Devis: Étude transversale de population hospitalière Participants: 253 participants (61 avec la DMLA, 45 avec la dystrophie cornéenne de Fuchs, 79 avec le glaucome et 68 contrôles) Méthodes: Nous avons recruté les patients parmi ceux qui se font soigner dans les cliniques d’ophtalmologie de l’Hôpital Maisonneuve-Rosemont (Montréal, Canada) de septembre 2009 à octobre 2010. Les patients atteints de la DMLA ou de la maladie de Fuchs ont une acuité visuelle inférieure à 20/40 dans les deux yeux, tandis que les patients avec du glaucome ont un champ visuel dans le pire oeil inférieur ou égal à -4dB. Les patients contrôles, qui ont été recrutés à partir des mêmes cliniques, ont une acuité visuelle et un champ visuel normaux. Nous avons colligé des données concernant la mobilité à partir des questionnaires (aire de mobilité et chutes) et des tests (test de l’équilibre monopodal, timed Up and Go (TUG) test). Pour mesurer la fonction visuelle nous avons mesuré l’acuité visuelle, la sensibilité au contraste et le champ visuel. Nous avons également révisé le dossier médical. Pour les analyses statistiques nous avons utilisé les régressions linéaire et logistique. Critères de jugement principaux: aire de mobilité, équilibre, test timed Up and Go, chutes Résultats: Les trois maladies oculaires ont été associées à des patrons différents de limitation de la mobilité. Les patients atteints de glaucome ont eu le type le plus sévère de restriction de mobilité; ils ont une aire de mobilité plus réduite, des scores plus bas au test TUG et ils sont plus enclins à avoir un équilibre faible et à faire plus de chutes que les contrôles (p < 0.05). De plus, comparativement aux contrôles, les patients ayant de la DMLA ou la dystrophie cornéenne de Fuchs ont eu une aire de mobilité réduite (p < 0.05). Les chutes n’ont pas été associées aux maladies oculaires dans cette étude. Conclusions: Nos résultats suggèrent que les maladies oculaires, et surtout le glaucome, limitent la mobilité chez les personnes âgées. De futures études sont nécessaires pour évaluer l’impact d’une mobilité restreinte chez cette population pour pouvoir envisager des interventions ciblées qui pourraient les aider à maintenir leur indépendance le plus longtemps possible.
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Objectif: Évaluer la relation entre la fonction cognitive chez les personnes âgées atteintes de dégénérescence maculaire reliée à l’âge (DMLA), de glaucome ou de dystrophie cornéenne de Fuchs et les comparer avec les personnes âgées n’ayant pas de maladie oculaire. Devis: Étude transversale de population hospitalière. Participants: 420 participants (113 avec la DMLA, 66 avec la dystrophie cornéenne de Fuchs, 130 avec le glaucome et 111 témoins). Méthodes: Nous avons recruté les patients à partir de la clinique d’ophtalmologie de l’Hôpital Maisonneuve-Rosemont (Montréal, Canada) de septembre 2009 à septembre 2013. Les patients atteints de la DMLA ou de la maladie de Fuchs ont une acuité visuelle inférieure à 20/40 dans les deux yeux, tandis que les patients avec du glaucome ont un champ visuel dans le pire œil inférieur ou égal à -4dB. Les patients contrôles, qui ont été recrutés à partir des mêmes cliniques, ont une acuité visuelle et un champ visuel normaux. Nous avons colligé des données concernant la fonction cognitive à partir du test Mini-Mental State Exam (MMSE)-version aveugle. Pour mesurer la fonction visuelle, nous avons mesuré l’acuité visuelle, la sensibilité au contraste et le champ visuel. Nous avons également révisé le dossier médical. Pour les analyses statistiques, nous avons utilisé la régression linéaire. Critère de jugement principal: MMSE-version aveugle. Résultats: Les trois maladies oculaires ont été associées à une limitation de la cognition. Le score de MMSE-version aveugle se situe de 0.7 à 0.8 unités plus basses par rapport au groupe contrôle. Comparativement aux contrôles, les patients avec maladies oculaires ont eu un score moyen diminué (P < 0.05). Le niveau d’éducation élevé est associé à une meilleure cognition (P < 0.001). Conclusions: Nos résultats suggèrent que les maladies oculaires sont associées à une diminution de la fonction cognitive chez les personnes âgées. De futures études sont nécessaires pour évaluer l’impact des maladies oculaires sur le déclin cognitif chez cette population pour pouvoir envisager des interventions ciblées qui pourraient les aider à maintenir leur indépendance le plus longtemps possible.
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Objective: Visual hallucinations (VH) most commonly occur in eye disease (ED), Parkinson’s disease (PD), and Lewy body dementia (LBD). The phenomenology of VH is likely to carry important information about the brain areas within the visual system generating them. Methods: Data from five controlled cross-sectional VH studies (164 controls, 135 ED, 156 PD, 79 (PDD 48 + DLB 31) LBD) were combined and analysed. The prevalence, phenomenology, frequency, duration, and contents of VH were compared across diseases and gender. Results: Simple VH were most common in ED patients (ED 65% vs. LBD 22% vs. PD 9%, Chi-square [χ2] test: χ2=31.43, df=2, p<0.001), whilst complex VH were more common in LBD (LBD 76% vs. ED 38%, vs PD 28%, Chi-square test: χ2=96.80, df=2, p<0.001). The phenomenology of complex VH was different across diseases and gender. ED patients reported more “flowers” (ED 21% vs. LBD 6% vs. PD 0%, Chi-square test: χ2=10.04, df=2, p=0.005) and “body parts” (ED 40% vs. LBD 17% vs. PD 13%, Chi-square test: χ2=11.14, df=2, p=0.004); in contrast LBD patients reported “people” (LBD 85% vs. ED 67% vs. PD 63%, Chi-square test: χ2=6.20, df=2, p=0.045) and “animals/insects” (LBD 50% vs. PD 42% vs. ED 21%, Chi-square test: χ2=9.76, df=2, p=0.008). Males reported more “machines” (13 % vs. 2%, Chi-square test: χ2=6.94, df=1, p=0.008), whilst females reported more “family members/children” (48% vs. 29%, Chi-square test: χ2=5.10, df=1, p=0.024). Conclusions: The phenomenology of VH is likely related to disease specific dysfunctions within the visual system and to past, personal experiences.
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Purpose: Alcohol consumption is inversely correlated with the incidence of cardiovascular disease. It is thought that red wine is specifically responsible for these cardiovascular benefits, due to its ability to reduce vascular inflammation, facilitate vasorelaxation, and inhibit angiogenesis. This is because of its high polyphenolic content. Resveratrol is the main biologically active polyphenol within red wine. Owing to its vascular-enhancing properties, resveratrol may be effective in the microcirculation of the eye, thereby helping prevent ocular diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Such conditions are accountable for worldwide prevalence of visual loss. Method: A review of the relevant literature was conducted on the ScienceDirect, Web of Science, and PubMed databases. Key words used to carry out the searches included 'red wine', 'polyphenols', 'resveratrol', 'eye' and 'ocular'. Articles relating to the effects of resveratrol on the eye were reviewed. Results: The protective effects of resveratrol within the eye are extensive. It has been demonstrated to have anti-oxidant, anti-apoptotic, anti-tumourogenic, anti-inflammatory, anti-angiogenic and vasorelaxant properties. There are potential benefits of resveratrol supplementation across a wide range of ocular diseases. The molecular mechanisms underlying these protective actions are diverse. Conclusion: Evidence suggests that resveratrol may have potential in the treatment of several ocular diseases. However, while there are many studies indicating plausible biological mechanisms using animal models and in-vitro retinal cells there is a paucity of human research. The evidence base for the use of resveratrol in the management of ocular diseases needs to be increased before recommendations can be made for the use of resveratrol as an ocular supplement. © 2014 Springer-Verlag.
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Background: The work environment of cocoa farmers exposes them to several ocular hazards that predispose them to eye diseases and injuries. However, the extent of ocular injuries and health seeking patterns following these injuries are unknown among cocoa farmers in Ghana. Objectives: To determine the prevalence of ocular injuries and health seeking behaviour following injury among cocoa farmers in Ghana. Methods: Five hundred and fifty six participants were recruited through simple random sampling using a multistage approach from four cocoa growing districts in Ghana. A structured questionnaire was used to collect relevant information such as demography, ocular hazards and injuries experienced. An ocular examination was also conducted to assess the eye health of the participants. Descriptive and regression statistics were used to analyze the data. The rate of ocular injuries was calculated by using the number of injuries reported that resulted in lost work time/days divided by the number of worker years at risk of injury (sum of years worked in cocoa farms for all the participants). Results: The rate of ocular injuries was 11.3/1000 worker years (95% CI: 9.4 - 31) which led to lost work time of 37.3/1000 worker years (95% CI: 34.1 - 40.8). The major causes of ocular injury were plants/branches (n=73, 51.1%), chemicals (n=27, 18.9%), cocoa pod/husk (n=14, 9.8%) and occurred mostly during weeding, harvesting and chemical spraying. Few (n=34, 6.1%) participants reported the use of ocular protection. Fifty-five (38.5%) participants visited the local chemical shops, while 37 (25.9%) visited hospitals/clinics for ocular treatment of their injuries. Conclusion: There is a high rate of ocular injuries among cocoa farmers who make insufficient use of appropriate eye care services. There is the need for eye health education among cocoa farmers in Ghana. Keywords:
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Many species of stomatopod crustaceans have multiple spectral classes of photoreceptors in their retinas. Behavioral evidence also indicates that stomatopods are capable of discriminating objects by their spectral differences alone, Most animals use only two to four different types of photoreceptors in their color vision systems, typically with broad sensitivity functions, but the stomatopods apparently include eight or more narrowband photoreceptor classes for color recognition. It is also known that stomatopods use several colored body regions in social interactions. To examine why stomatopods may be so 'concerned' with color, we measured the absorption spectra of visual pigments and intrarhabdomal filters, and the reflectance spectra from different parts of the bodies of several individuals of the gonodactyloid stomatopod species, Gonodactylus smithii. We then applied a model of multiple dichromatic channels for color encoding to examine whether the finely tuned color vision was specifically co-evolved with their complex color signals. Although the eye design of stomatopods seems suitable for detecting color signals of their own, the detection of color signals from other animals, such as reef fishes, can be enhanced as well. Color vision in G. smithii is therefore not exclusively adapted to detect its own color signals, but the spectral tuning of some photoreceptors (e.g. midband Rows 2 and 3) enhances the contrast of certain color signals to a large enough degree to make co-evolution between color vision and these rather specific color signals likely. Copyright (C) 2000 S. Karger AG, Basel.