Chronic Cigarette Smoke Causes Oxidative Damage and Apoptosis to Retinal Pigmented Epithelial Cells in Mice

The purpose of this study was to determine whether mice exposed to chronic cigarette smoke develop features of early age-related macular degeneration (AMD). Two month old C57Bl6 mice were exposed to either filtered air or cigarette smoke in a smoking chamber for 5 h/day, 5 days/week for 6 months. Eyes were fixed in 2.5% glutaraldehyde/2% paraformaldehyde and examined for ultrastructural changes by transmission electron microscopy. The contralateral eye was fixed in 2% paraformaldehyde and examined for oxidative injury to the retinal pigmented epithelium (RPE) by 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-OHdG) immunolabeling and apoptosis by TUNEL labeling. Mice exposed to cigarette smoke had immunolabeling for 8-OHdG in 85±3.7% of RPE cells counted compared to 9.5±3.9% in controls (p<0.00001). Bruch membrane was thicker in mice exposed to smoke (1086±332 nm) than those raised in air (543±132 nm; p = 0.0069). The two most pronounced ultrastructural changes (severity grading scale from 0–3) seen were a loss of basal infoldings (mean difference in grade = 1.98; p<0.0001), and an increase in intracellular vacuoles (mean difference in grade = 1.7; p<0.0001). Ultrastructural changes to Bruch membrane in cigarette-smoke exposed mice were smaller in magnitude but consistently demonstrated significantly higher grade injury in cigarette-exposed mice, including basal laminar deposits (mean difference in grade = 0.54; p<0.0001), increased outer collagenous layer deposits (mean difference in grade = 0.59; p = 0.002), and increased basal laminar deposit continuity (mean difference in grade = 0.4; p<0.0001). TUNEL assay showed a higher percentage of apoptotic RPE from mice exposed to cigarette smoke (average 8.0±1.1%) than room air (average 0±0%; p = 0.043). Mice exposed to chronic cigarette smoke develop evidence of oxidative damage with ultrastructural degeneration to the RPE and Bruch membrane, and RPE cell apoptosis. This model could be useful for studying the mechanism of smoke induced changes during early AMD

RPE and Stem Cell Therapy

acceptedVersionPeer reviewe

Hábito alimentar de escolares adolescentes de um município do oeste do Paraná Food habits of adolescent students from a municipality in western Paraná, Brazil

OBJETIVO: Este estudo objetivou identificar o padrão de consumo alimentar de 2562 escolares de 14 a 19 anos das escolas urbanas, públicas e particulares, do município de Toledo, Paraná, bem como os fatores associados à classe econômica e ao sexo. MÉTODOS: Para caracterizar o consumo alimentar utilizou-se Questionário de Freqüência de Consumo Alimentar validado. A análise estatística foi realizada seguindo os grupos da pirâmide alimentar, e as associações das variáveis foram realizadas pelo teste Qui-quadrado com nível de significância de 5%. RESULTADOS: Os alimentos que apresentaram maior consumo em cada grupo foram: pão e arroz, alface e tomate, banana e laranja, leite integral e desnatado, carne de gado e frango, feijão, margarina e maionese, açúcar e balas/doces. A associação da freqüência de consumo com a renda familiar foi significante entre os mais pobres para os grupos dos pães, cereais, raízes e tubérculos, das leguminosas e dos óleos e gorduras. Entre os mais ricos encontram-se os grupos das hortaliças, das frutas, dos leites e produtos lácteos. Quanto ao sexo, as meninas consomem mais alimentos dos grupos das hortaliças e dos açúcares e doces, já entre os meninos prevalece o consumo de leite, leguminosas, óleos e gorduras. CONCLUSÃO: Esses resultados mostram diferença de consumo entre os sexos e sugerem que a renda famíliar associa-se ao consumo alimentar dos escolares.<br>OBJECTIVE: The objective of this study was to identify the food intake patterns of 2562 students aging from 14 to 19 years from public and private schools of the municipality of Toledo, Paraná, Brazil. Associations between intake patterns and gender and intake patterns and social class were also investigated. METHODS: A validated food frequency questionnaire was used to characterize food intake. Statistical analysis was based on the food guide pyramid and the variables associated with the chi-square test, using a significance level set at 5%. RESULTS: The foods with highest intakes were: bread and rice, lettuce and tomato, banana and orange, whole milk and skim milk, beef and poultry, beans, margarine and mayonnaise, sugar and candies/sweets. The association between intake frequency and family income was significant among the poorest for the following groups: breads, cereals, nuts and seeds, legumes and oils and fats. Among the wealthiest, the groups were: vegetables, fruits, milks and dairy. Regarding gender, girls consume more vegetables and sweets and boys consume more milk, legumes, oils and fats. CONCLUSION: These results show that there is a difference in intakes between genders and suggest that family income is associated with food intake among students