INTRODUCTION: As populations are adopting a Western lifestyle, with high intake of dietary sugar and fat and low physical activity, the risk of developing Type 2 Diabetes is only increasing dramatically. Diabetes leads to drastic alterations within the body, primarily leading to neuropathies, nephropathies and retinopathies. As the prevalence of diabetes increases, it is important to understand the threat that it poses to the retina, and ultimately, vision. OBJECTIVE: We plan to compare the retina of diabetic patients with retinopathies to normal, healthy patients to understand the differences between them. We will be using a novel imaging technique, called Laser Speckle Flowgraphy, which provides the Mean Blur Rate, a value directly related to the blood flow velocity within the retina, specifically the optic nerve head. Using the calculated Mean Blur Rate, this study will quantify baseline blood flows in patients with diabetic retinopathies. This project aims to understand and differentiate the Mean Blur Rate of healthy patients and diabetic patients, including inter-patient and intra-patient comparisons, as well as changes in the Mean Blur Rate over time. The potential influence of treatment factors, such as intravitreal injection treatment or laser treatment, or demographic factors, such as age and race, on the Mean Blur Rate of diabetic retinopathy patients will also be evaluated. By understanding the difference in the retinas of diabetic patients and healthy patients, we can work towards preventing the loss of vision and function. METHODS: A total of 25 Type 2 diabetic patients with a diabetic retinopathy equaling 46 eyes were compared to 20 healthy patients, equaling 40 eyes. We collected the Mean Blur Rate for comparison between the two populations. Data was compared with correlation, t-test and ANOVA studies to find whether demographic or treatment variables influenced the Mean Blur Rate of diabetic retinopathy patients. RESULTS: We found a difference between the Mean Blur Rate, and thus blood flow, between the retina of diabetic and healthy patients. Diabetic patients tended to have a lower flow, presumably attributable the effects of hyperglycemia on blood circulation. Diabetic patients also have a significant difference in the Mean Blur Rate between both of their eyes, indicating that their hyperglycemia may affect both eyes differently (p<0). There was significant variability within both diabetic retinopathy patients and normal, healthy patients (p<0 for healthy patients and p<0.001 for diabetic patients). This is expected as blood circulation can be affected by a variety of factors other than disease status. We also found that the MBR of diabetics who were treated with intravitreal injections was on average higher than those who had not received intravitreal treatment. (p<0.05) CONCLUSION: Our study highlights how diabetic retinopathy impacts retinal blood flow, as well as showcases how Laser Speckle Flowgraphy can be used as a reliable method to measure and compare retinal blood velocities. Further studies are needed to understand how exactly diabetes affects blood circulation, although several theories are currently available. We also found a relation between previous intravitreal injection history and the blood flow velocity, but other studies have had mixed results on how exactly these injections alter the blood flow within the retina. Future studies can be conducted to better understand this relationship and uncover whether the effect on blood flow velocity is related to the drug used for the intravitreal injection or some other factor.

No Estado de São Paulo, desenvolveu-se o Plano de Oftalmologia Sanitária Escolar, no período de 1973 a 1976, junto às escolas da rede de ensino oficial estadual, que se propunha a detectar distúrbios visuais de escolares, prover a devida assistência, respaldado por atividades educativas e proceder a levantamento de dados sobre a problemática oftalmológica existente. Tratando-se de programação intersetorial, envolvendo as Secretarias de Estado da Saúde e da Educação, fez-se necessário todo um planejamento técnico-administrativo articulado, seguido de procedimentos de coordenação, supervisão e avaliação que se fizeram presentes em todo o transcorrer do plano. Mediante mecanismo de descentralização da organização dos serviços de Saúde e de Educação, o trabalho atingiu todas as regiões administrativas do Estado, com participação de grande contingente de pessoal da rede escolar, técnicos e especialistas em saúde, entidades governamentais, particulares e comunidade em geral. Considerando a metodologia empregada no plano e os resultados obtidos, faz-se pertinente a proposição de discutir alguns aspectos considerados relevantes, na tentativa de que este estudo possa oferecer subsídios para iniciativas semelhantes de pessoas ou órgãos interessados na problemática visual de escolares. / The Sanitary School Opthalmology Plan was developed in the State of São Paulo from 1973 to 1976 in schools of the public oficial teaching complex, aiming to detect the visual problems in school children, provide their proper care, based upon educational activities and set up the data on the existing ophthalmological problem. Dealing with an intersectorial program involving Health and Education Departments of the State of São Paulo, a technic administrative interrelated plan was necessary, followed by coordination procedures, as well as supervision and evaluation while the Plan was being carried out. Through the mechanism of decentralization of the organization of Health and Education services the work has reached all the administrative areas of the State of São Paulo, with the participation of a great contingent of the school complex personnel, technicians and specialists in health, as well as governmental and private entities and the community in general. Taking into account the methodology used in the Plan and the results obtained, the discussion of some relevant aspects is important, hoping that this work may provide subsidies for similar activities of people or services interested in the visual problem of school children.

No Estado de São Paulo, desenvolveu-se o Plano de Oftalmologia Sanitária Escolar, no período de 1973 a 1976, junto às escolas da rede de ensino oficial estadual, que se propunha a detectar distúrbios visuais de escolares, prover a devida assistência, respaldado por atividades educativas e proceder a levantamento de dados sobre a problemática oftalmológica existente. Tratando-se de programação intersetorial, envolvendo as Secretarias de Estado da Saúde e da Educação, fez-se necessário todo um planejamento técnico-administrativo articulado, seguido de procedimentos de coordenação, supervisão e avaliação que se fizeram presentes em todo o transcorrer do plano. Mediante mecanismo de descentralização da organização dos serviços de Saúde e de Educação, o trabalho atingiu todas as regiões administrativas do Estado, com participação de grande contingente de pessoal da rede escolar, técnicos e especialistas em saúde, entidades governamentais, particulares e comunidade em geral. Considerando a metodologia empregada no plano e os resultados obtidos, faz-se pertinente a proposição de discutir alguns aspectos considerados relevantes, na tentativa de que este estudo possa oferecer subsídios para iniciativas semelhantes de pessoas ou órgãos interessados na problemática visual de escolares. / The Sanitary School Opthalmology Plan was developed in the State of São Paulo from 1973 to 1976 in schools of the public oficial teaching complex, aiming to detect the visual problems in school children, provide their proper care, based upon educational activities and set up the data on the existing ophthalmological problem. Dealing with an intersectorial program involving Health and Education Departments of the State of São Paulo, a technic administrative interrelated plan was necessary, followed by coordination procedures, as well as supervision and evaluation while the Plan was being carried out. Through the mechanism of decentralization of the organization of Health and Education services the work has reached all the administrative areas of the State of São Paulo, with the participation of a great contingent of the school complex personnel, technicians and specialists in health, as well as governmental and private entities and the community in general. Taking into account the methodology used in the Plan and the results obtained, the discussion of some relevant aspects is important, hoping that this work may provide subsidies for similar activities of people or services interested in the visual problem of school children.

Ischaemic cell death has been implicated in a number of retinal diseases, including glaucomatous neuropathy, proliferative diabetic retinopathy and a range of vascular diseases. The cascade of events leading to cell death involves both cellular metabolic changes and a functional component. However, it is yet unknown how long these changes persist, whether all cell classes are affected, and the characteristics of recovery. Moreover, there have been few studies correlating the neurochemical changes with the ensuing functional changes. The aim of this thesis was to track the metabolic and functional recovery of the ischaemic rat retina, given the premise that: (1) amino acid neurochemistry reflects metabolic integrity and cellular identity, and; (2) the permeation of a cation channel probe called agmatine reflects channel functionality. Quantitative pattern recognition analysis of overlapping amino acid and agmatine expression profiles were used to provide a statistically robust classification of cells according to metabolic and functional characteristics. This classification was spatially complete and with single cell resolution. Finally, the electroretinogram was used to also assess retinal function and corroborate the observed neurochemical changes. These measures were taken at intervals for up to two weeks of reperfusion. The results show that by 48 hours of reperfusion, amino acid metabolism had returned to near normal levels, although cell classes were missing, and there was persistant cation channel gating anomalies. Immunocytochemical labeling identified a preferential loss of cone bipolar cells, with all remaining rod bipolar cells showing increased cation channel gating. The electroretinogram and agmatine experiments showed that this dysfunction is likely due to abnormal glutamate release from pre-synaptic photoreceptors, detected by changes in post-synaptic agmatine permeation, and not due to the presence of anomalous metabotropic glutamate receptors. Cholinergic amacrine cells demonstrated persistant neurochemical labeling, but did not show cationic flux following stimulation by glutamate agonists. In conclusion, the retina shows remarkable recovery in the amino acid metabolism, although functional changes persist. Finally, structural integrity or immunocytochemical labeling does not necessarily imply that cells maintain functional receptors, or that neurotransmitter release is normal secondary to disease. / Whole document restricted, but available by request, use the feedback form to request access.

Ischaemic cell death has been implicated in a number of retinal diseases, including glaucomatous neuropathy, proliferative diabetic retinopathy and a range of vascular diseases. The cascade of events leading to cell death involves both cellular metabolic changes and a functional component. However, it is yet unknown how long these changes persist, whether all cell classes are affected, and the characteristics of recovery. Moreover, there have been few studies correlating the neurochemical changes with the ensuing functional changes. The aim of this thesis was to track the metabolic and functional recovery of the ischaemic rat retina, given the premise that: (1) amino acid neurochemistry reflects metabolic integrity and cellular identity, and; (2) the permeation of a cation channel probe called agmatine reflects channel functionality. Quantitative pattern recognition analysis of overlapping amino acid and agmatine expression profiles were used to provide a statistically robust classification of cells according to metabolic and functional characteristics. This classification was spatially complete and with single cell resolution. Finally, the electroretinogram was used to also assess retinal function and corroborate the observed neurochemical changes. These measures were taken at intervals for up to two weeks of reperfusion. The results show that by 48 hours of reperfusion, amino acid metabolism had returned to near normal levels, although cell classes were missing, and there was persistant cation channel gating anomalies. Immunocytochemical labeling identified a preferential loss of cone bipolar cells, with all remaining rod bipolar cells showing increased cation channel gating. The electroretinogram and agmatine experiments showed that this dysfunction is likely due to abnormal glutamate release from pre-synaptic photoreceptors, detected by changes in post-synaptic agmatine permeation, and not due to the presence of anomalous metabotropic glutamate receptors. Cholinergic amacrine cells demonstrated persistant neurochemical labeling, but did not show cationic flux following stimulation by glutamate agonists. In conclusion, the retina shows remarkable recovery in the amino acid metabolism, although functional changes persist. Finally, structural integrity or immunocytochemical labeling does not necessarily imply that cells maintain functional receptors, or that neurotransmitter release is normal secondary to disease. / Whole document restricted, but available by request, use the feedback form to request access.

Ischaemic cell death has been implicated in a number of retinal diseases, including glaucomatous neuropathy, proliferative diabetic retinopathy and a range of vascular diseases. The cascade of events leading to cell death involves both cellular metabolic changes and a functional component. However, it is yet unknown how long these changes persist, whether all cell classes are affected, and the characteristics of recovery. Moreover, there have been few studies correlating the neurochemical changes with the ensuing functional changes. The aim of this thesis was to track the metabolic and functional recovery of the ischaemic rat retina, given the premise that: (1) amino acid neurochemistry reflects metabolic integrity and cellular identity, and; (2) the permeation of a cation channel probe called agmatine reflects channel functionality. Quantitative pattern recognition analysis of overlapping amino acid and agmatine expression profiles were used to provide a statistically robust classification of cells according to metabolic and functional characteristics. This classification was spatially complete and with single cell resolution. Finally, the electroretinogram was used to also assess retinal function and corroborate the observed neurochemical changes. These measures were taken at intervals for up to two weeks of reperfusion. The results show that by 48 hours of reperfusion, amino acid metabolism had returned to near normal levels, although cell classes were missing, and there was persistant cation channel gating anomalies. Immunocytochemical labeling identified a preferential loss of cone bipolar cells, with all remaining rod bipolar cells showing increased cation channel gating. The electroretinogram and agmatine experiments showed that this dysfunction is likely due to abnormal glutamate release from pre-synaptic photoreceptors, detected by changes in post-synaptic agmatine permeation, and not due to the presence of anomalous metabotropic glutamate receptors. Cholinergic amacrine cells demonstrated persistant neurochemical labeling, but did not show cationic flux following stimulation by glutamate agonists. In conclusion, the retina shows remarkable recovery in the amino acid metabolism, although functional changes persist. Finally, structural integrity or immunocytochemical labeling does not necessarily imply that cells maintain functional receptors, or that neurotransmitter release is normal secondary to disease. / Whole document restricted, but available by request, use the feedback form to request access.

Ischaemic cell death has been implicated in a number of retinal diseases, including glaucomatous neuropathy, proliferative diabetic retinopathy and a range of vascular diseases. The cascade of events leading to cell death involves both cellular metabolic changes and a functional component. However, it is yet unknown how long these changes persist, whether all cell classes are affected, and the characteristics of recovery. Moreover, there have been few studies correlating the neurochemical changes with the ensuing functional changes. The aim of this thesis was to track the metabolic and functional recovery of the ischaemic rat retina, given the premise that: (1) amino acid neurochemistry reflects metabolic integrity and cellular identity, and; (2) the permeation of a cation channel probe called agmatine reflects channel functionality. Quantitative pattern recognition analysis of overlapping amino acid and agmatine expression profiles were used to provide a statistically robust classification of cells according to metabolic and functional characteristics. This classification was spatially complete and with single cell resolution. Finally, the electroretinogram was used to also assess retinal function and corroborate the observed neurochemical changes. These measures were taken at intervals for up to two weeks of reperfusion. The results show that by 48 hours of reperfusion, amino acid metabolism had returned to near normal levels, although cell classes were missing, and there was persistant cation channel gating anomalies. Immunocytochemical labeling identified a preferential loss of cone bipolar cells, with all remaining rod bipolar cells showing increased cation channel gating. The electroretinogram and agmatine experiments showed that this dysfunction is likely due to abnormal glutamate release from pre-synaptic photoreceptors, detected by changes in post-synaptic agmatine permeation, and not due to the presence of anomalous metabotropic glutamate receptors. Cholinergic amacrine cells demonstrated persistant neurochemical labeling, but did not show cationic flux following stimulation by glutamate agonists. In conclusion, the retina shows remarkable recovery in the amino acid metabolism, although functional changes persist. Finally, structural integrity or immunocytochemical labeling does not necessarily imply that cells maintain functional receptors, or that neurotransmitter release is normal secondary to disease. / Whole document restricted, but available by request, use the feedback form to request access.

Made available in DSpace on 2014-10-09T12:26:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:14Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:26:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:14Z (GMT). No. of bitstreams: 0 / Os aplicadores clínicos de 90Sr+90Y são instrumentos utilizados em procedimentos de braquiterapia e devem ser calibrados periodicamente, de acordo com normas e recomendações internacionais. Neste trabalho, foram estudados quatro métodos de calibração de aplicadores dermatológicos e oftálmicos, comparando-se os resultados com os fornecidos pelos certificados de calibração dos fabricantes dos aplicadores. Os métodos envolveram o aplicador clínico padrão do Laboratório de Calibração de Instrumentos (LCI), calibrado pelo laboratório padrão primário americano do National Institute of Standards and Technology, como referência; um aplicador da Amersham, também pertencente ao LCI, como referência; uma mini-câmara de extrapolação desenvolvida no IPEN como padrão absoluto; e dosimetria termoluminescente. A mini-câmara de extrapolação e uma câmara de extrapolação comercial PTW foram estudadas com relação ao seu desempenho por meio de testes de controle de qualidade, como corrente de fuga, repetitividade e reprodutibilidade. A distribuição de dose em profundidade na água, estudo de grande importância na dosimetria de aplicadores clínicos, foi determinada utilizando-se a mini-câmara de extrapolação e dosímetros termoluminescentes. Os resultados obtidos foram considerados satisfatórios para os dois casos, quando comparados com os dados fornecidos pela norma IAEA (2002). Além disso, foi desenvolvido um sistema postal dosimétrico para a calibração de aplicadores clínicos por meio da técnica da termoluminescência, para ser enviado para clínicas e hospitais, sem a necessidade do transporte das fontes ao LCI do IPEN para calibração. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Mammalian corneal endothelial cells are considered to be non-proliferative due to the arrest of cells at the G1 phase of the cell cycle. The purpose of this study was to determine whether the down regulation of cyclin dependant kinase inhibitors (p21cip1 and p27kip1) levels by Endothelin-1 (ET-1), would overcome the G1 phase arrest and promote cell cycle progression and proliferation in cultured BCECs (Bovine corneal endothelial cells). BCECs were isolated from bovine corneas and cultured in DMEM supplemented with 10% serum. 5-Bromo 2-deoxy Uridine (BrdU) incorporation was determined in serum starved cultures in 24-well plates as a measure of cell proliferation. Confluent serum starved cells grown in T-25 flasks were treated with 100nM Endothelin-1 in DMEM. The control cells were left untreated in serum free medium. Total cellular protein was isolated using RIPA buffer and quantified according to the Peterson modification of the Lowry method. The level of expression of p21cip1 and p27kip1 proteins relative to β-actin was determined by western blotting technique. Immuno fluorescent localization of p27kip1 was performed using polyclonal anti-p27kip1 and anti-p21cip1 antibodies in confluent and growing cells. An increase in cell proliferation was observed in sub-confluent cultures with Endothelin-1 treatment. This evidence was supported by an increase (~18%) in BrdU incorporation in response to Endothelin-1. Densitometry analysis of immunoblots revealed an increase in the expression of p27kip1 in confluent cell cultures when compared to sub-confluent, dividing cells. p21cip1 was almost undetectable in sub-confluent, actively dividing cultures. Immuno fluorescent analysis revealed that the nuclear staining of p27kip1 was apparently decreased with ET-1 treatment. In conclusion, Endothelin-1 treatment resulted in decrease in p27kip1 and p21cip1 expression in confluent cultures that was greatest at 30 hr of post incubation with Endothelin-1. Endothelin-1 appears to promote cell proliferation. Expression of p27kip1 and p21cip1 was greatly reduced in actively dividing BCECs. Endothelin-1 treatment down-regulated these cyclin dependent kinase inhibitors and may promote cell cycle progression via this mechanism.