251 research outputs found
Efficacy of fatty acids dietary supplement in polyethylene glycol-induced mouse model of retinal degeneration
Current knowledge of the benefits of nutrition supplements for eye pathologies is based largely on the use of appropriate animal models, together with defined dietary supplementation. Here, C57BL6 mice were subretinally injected with polyethylene glycol (PEG)-400, an established model of retinal degeneration with a dry age-related macular degeneration (AMD)-like phenotype, an eye pathology that lacks treatment. In response to PEG-400, markers of the complement system, angiogenesis,inflammation,gliosis,andmacrophageinfiltrationwereupregulatedinbothretinasand retinal pigment epithelium (RPE)/choroids, whereas dietary supplementation with a mixture based on fatty acids counteracted their upregulation. Major effects include a reduction of inflammation, in both retinas and RPE/choroids, and an inhibition of macrophage infiltration in the choroid, yet not in the retina, suggesting a targeted action through the choroidal vasculature. Histological analysis revealed a thinning of the outer nuclear layer (ONL), together with dysregulation of the epithelium layer in response to PEG-400. In addition, immunohistofluorescence demonstrated Müller cell gliosis and macrophage infiltration into subretinal tissues supporting the molecular findings. Reduced ONL thickness,gliosis,andmacrophageinfiltrationwerecounteractedbythedietsupplement. The present data suggest that fatty acids may represent a useful form of diet supplementation to prevent or limit the progression of dry AMD
Autophagy-mediated neuroprotection induced by octreotide in an ex vivo model of early diabetic retinopathy
Neuronal injury plays a major role in diabetic retinopathy (DR). Our hypothesis was that the balance between neuronal death and survival may depend on a similar equilibrium between apoptosis and autophagy and that a neuroprotectant may act by influencing this equilibrium. Ex vivo mouse retinal explants were treated with high glucose (HG) for 10days and the somatostatin analog octreotide (OCT) was used as a neuroprotectant. Chloroquine (CQ) was used as an autophagy inhibitor. Apoptotic and autophagic markers were evaluated using western blot and immunohistochemistry. HG-treated explants displayed a significant increase of apoptosis paralleled by a significant decrease of the autophagic flux, which was likely to be due to increased activity of the autophagy regulator mTOR (mammalian target of rapamycin). Treatment with OCT rescued HG-treated retinal explants from apoptosis and determined an increase of autophagic activity with concomitant mTOR inhibition. Blocking the autophagic flux with CQ completely abolished the anti-apoptotic effect of OCT. Immunohistochemical observations showed that OCT-induced autophagy is localized to populations of bipolar and amacrine cells and to ganglion cells. These observations revealed the antithetic role of apoptosis and autophagy, highlighting their equilibrium from which neuronal survival is likely to depend. These data suggest the crucial role covered by autophagy, which could be considered as a molecular target for DR neuroprotective treatment strategies
Mensuração dos custos e avaliação de rendas em sistemas de produção de leite caprino nos Cariris Paraibanos.
Resumo: Objetivou-se mensurar o custo de produção do leite e avaliar a renda na atividade caprina por sistemas de produção. Os sistemas de produção estão localizados na microrregião dos Cariris Paraibanos e foram definidos por critérios de eficiência técnica e econômica, com método de agrupamento por análise multivariada e formação de cinco grupos. O método utilizado para o custo de produção foi o custo operacional, e o critério adotado para a conversão do custo da atividade leiteira para o custo do leite foi da participação da renda do leite na renda bruta da atividade. Os critérios adotados de análise de rendas foram margem bruta e margem líquida. No cômputo do custo de produção do leite de cabra, os valores foram de R 0,73/L; R 0,88/L; e R 9.147,30 e R 0.67/L R 0.80/L, R 1.21/L for the production systems 1, 2, 3, 4 and 5. Systems of production 1 and 2 with high technology and net margin of R 3,995.18 in the milk activity, were the ones that showed the lowest costs and they are economically the most advantageou
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