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Diss. (sammanfattning) Linköping : Univ., 2006. / Härtill 5 uppsatser.

Made available in DSpace on 2015-12-06T23:04:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2003 / Objetivo: Avaliar, por meio de estudo epidemiologico, a frequencia e a distribuicao corporea dos nevos melanociticos adquiridos (NMA) e observar a influencia das variaveis ambientais e constitucionais nos fenotipos heterogeneos, em uma regiao geografica de intensa exposicao solar. Metodos: Foi realizado estudo transversal das frequencias absoluta e relativa dos NMA de todos os tamanhos, com a inclusao de todas as regioes anatomicas padronizadas pelo protocolo internacional (IARCI OMS, 1990), em 1.279 criancas e adolescentes, com idades de 2 a 18 anos, de creches e escolas publicas na cidade de Votuporanga (20°S), São Paulo, Brasil. Resultados: Setenta e cinco por cento dos individuos apresentaram ate 13 nevos, 50 por cento ate seis nevos e 5 por cento mais de 30 nevos. A contagem de NMA de todos os tamanhos foi mais alta nas regioes toracica e abdominal superior, ombros, face e dorso. Os membros superiores apresentaram mais NMA do que os membros inferiores e houve baixa contagem de NMA nas maos e nos pes. O sexo feminino apresentou quantidade de NMA estatisticamente semelhante ao sexo masculino. As mulheres apresentaram maior contagem de NMA nas faces externas dos membros superiores, face interna do membro superior direito, faces anteriores e posteriores dos membros inferiores, e gluteos. Os homens apresentaram maior contagem de NMA na regiao posterior do pescoco. Observou-se aumento progressivo da contagem de NMA com a idade, com picos aos 13 e aos 16 anos. As regioes de exposicao solar apresentaram maior numero de NMA de maiores diametros (ombros, torax, abdome superior, face e dorso). Os tamanhos dos NMA apresentaram correlacao com a idade, exceto para os gluteos, faces internas dos membros superiores e face posterior da perna direita. Houve forte correlacao entre o numero de NMA e o complexo de pele tipo 3. Exposicao solar, cor dos cabelos e dos olhos, efelides e queimadura solar, tambem apresentaram associacao com alta contagem dos NMA. Conclusoes: Os NMA estao distribuidos por toda a superficie corporal, e em maior numero e tamanho nas regioes de exposicao solar. O aparecimento precoce dos NMA, a distribuicao corporea e a contagem baixa de NMA na populacao heterogenea sustentam a hipotese de que a miscigenacao racial e as regioes anatomicas especificas apresentam diferencas no potencial de proliferacao dos nevos / BV UNIFESP: Teses e dissertações

Made available in DSpace on 2015-07-22T20:50:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-29 / Objetivos: Avaliar a concordância no diagnóstico das lesões cutâneas pigmentadas por meio do exame dermatoscópico presencial e a distância. Analisar a concordância diagnóstica da teledermatoscopia e do exame dermatoscópico presencial em relação ao resultado anatomopatológico. Verificar a acurácia, a sensibilidade e a especificidade da teledermatoscopia na detecção das lesões pigmentadas malignas. Métodos: Sessenta e quatro lesões cutâneas pigmentadas foram submetidas a exame clínico e dermatoscópico realizado presencialmente por dois examinadores com experiência em dermatoscopia, durante o ano de 2005, no ambulatório de dermatoscopia do Departamento de Dermatologia da Universidade Federal de São Paulo (UNIFESP). Após dois anos, imagens digitais clínicas e dermatoscópicas destes casos foram reexaminadas pelos mesmos especialistas por meio da transmissão de imagens e de dados clínicos via web. Resultados: Observou-se boa concordância diagnóstica entre o exame presencial e a teledermatoscopia com valor de Kappa de 0,698 (IC a 95% - [0,575; 0,821]). Verificou-se também boa concordância entre o exame presencial e a teledermatoscopia com o resultado anatomopatológico (padrão ouro) com valores de Kappa de 0,728 (IC a 95% - [0,608; 0,848]) e 0,656 (IC a 95% - [0,526; 0,785]), respectivamente. Constatou-se 84% de acurácia, 93% de sensibilidade e 78% de especificidade na detecção das lesões pigmentadas malignas no exame dermatoscópico a distância. Dois casos falsos negativos foram observados pela teledermatoscopia. Não houve diferença estatisticamente significante entre a sensibilidade, a especificidade e a acurácia das duas modalidades diagnósticas. Conclusões: O exame dermatoscópico a distância pela transmissão de imagens digitais e de dados clínicos proporcionou acurácia diagnóstica, sensibilidade e especificidade comparáveis ao exame convencional. A teledermatoscopia mostrou ser método eficaz e confiável na detecção das lesões malignas constituindo ferramenta importante na triagem das lesões pigmentadas. A boa concordância diagnóstica entre a avaliação via web e o exame presencial destaca a aplicabilidade da teledermatoscopia como instrumento de assistência especializada em regiões de difícil acesso ou carentes no setor de saúde. / Objectives: To evaluate agreement in diagnosis of pigmented skin lesions through presential or remote dermoscopic examination. To analyze diagnosis agreement of teledermoscopy and presential dermoscopic examination regarding pathological findings. To verify accuracy, sensibility and specificity of teledermoscopy in detection of malignant pigmented lesions. Methods: A total of 64 pigmented skin lesions were submitted to clinical and dermoscopic examinations performed presentially by two examiners experienced in dermoscopy, at the Dermoscopy Outpatient’s Clinic, Department of Dermatology, Universidade Federal de São Paulo (UNIFESP), in 2005. Two years later, the digital clinical and dermoscopic images of these cases were re-examined by the same specialists through transmission of images and clinical data via web. Agreement between presential diagnosis and telediagnosis was assessed by the Kappa (κ) statistic calculation and its respective 95% confidence interval (95% CI). Through this calculation, the agreement between presential presumptive diagnoses and telediagnoses with pathological findings was analyzed. Sensitivity, specificity and accuracy of two diagnostic modalities were obtained using the pathological examination as the gold standard. The respective 95% confidence interval (95% CI) was calculated for each diagnostic measurement. Results: Good diagnostic agreement was observed between presential examination and teledermoscopy, with a Kappa value of 0.698 (95% CI - [0.575; 0.821]). Good agreement was also found between conventional examination and teledermoscopy, and the pathological findings (gold standard) had Kappa values of 0.728 (95% CI - [0.608; 0.848]) and 0.656 (95% CI - [0.526; 0.785]), respectively. Accuracy of 84%, sensitivity of 93% and specificity of 78% were observed in detecting malignant pigmented lesions by remote dermoscopic examination. Two false negative cases were observed through teledermoscopy. There was no statistically significant difference in sensitivity, specificity and accuracy of both diagnostic methods. Conclusions: Remote dermoscopic examination by means of digital image transmission and of clinical data provided diagnostic accuracy, sensitivity and specificity comparable to conventional examination. Teledermoscopy proved to be an efficient and reliable method to detect malignant lesions, representing an important tool to screen pigmented lesions. The good diagnostic agreement between assessment via web and conventional examination highlights the applicability of teledermoscopy as a specialized assistance tool in regions that are difficult to reach or lack health resources. / TEDE / BV UNIFESP: Teses e dissertações

A potential alternative to acrylonitrile-butadiene-styrene (ABS) and polycarbonate+ABS (PC+ABS), pigmented mineral-filled polypropylene (PP) finds an opening in automotive interior components such as instrument panels, knee bolsters, consoles, etc. Because of the lack of surface aesthetics, pigmented mineral-filled PP is experiencing a limitation to its acceptance in many applications. This study focuses on exploring various mineral fillers and additives in polypropylene to provide a material with enhanced scratch resistance. Several physical properties including Rockwell and Shore D hardness are investigated, and it is determined that Filler W improves scratch resistance. It is also determined that Filler T-filled-PP has poor scratch resistance even with the addition of a lubricant.

<p>Complement factor H (CFH) is a major susceptibility gene for age-related macular degeneration (AMD); however, its impact on AMD pathobiology is unresolved. Here, the role of CFH in the development of AMD pathology in vivo was interrogated by analyzing aged Cfh+/- and Cfh-/- mice fed a high fat, cholesterol-enriched diet. Strikingly, decreased levels of CFH led to increased sub-retinal pigmented epithelium (RPE) deposit formation, specifically basal laminar deposits, following high fat diet. Mechanistically, our data show that deposits are due to CFH competition for lipoprotein binding sites in Bruch’s membrane. Interestingly and despite sub-RPE deposit formation occurring in both Cfh+/- and Cfh-/- mice, RPE damage accompanied by loss of vision occurred only in old Cfh+/- mice. We demonstrate that such pathology is a function of excess complement activation and C5a production, associated with monocyte recruitment, in Cfh+/- mice versus complement deficiency in Cfh-/- animals. Due to the CFH dependent increase in sub-RPE deposit height we interrogated the potential of CFH as a novel regulator of Bruch’s membrane lipoprotein binding and show, using human Bruch’s membrane explants, that CFH removes endogenous human lipoproteins in aged donors. Interestingly, although the CFH H402 variant shows altered binding to BrM, this does not affect its ability to remove endogenous lipoproteins. This new understanding of the complicated interactions of CFH in AMD-like pathology provides an improved foundation for the development of targeted therapies for AMD.</p> / Dissertation

Doctor of Philosophy (Medicine) / Background: Diabetic vascular complications affect both the macro- and microvasculature. Microvascular pathology in diabetes may be mediated by biochemical factors that precipitate cellular changes at both the gene and protein levels. In the diabetic retina, vascular pathology is found mainly in microvessels, including the retinal precapillary arterioles, capillaries and venules. Macular oedema secondary to breakdown of the inner blood-retinal barrier is the most common cause of vision impairment in diabetic retinopathy. Müller cells play a critical role in the trophic support of retinal neurons and blood vessels. In chronic diabetes, Müller cells are increasingly unable to maintain their supportive functions and may themselves undergo changes that exacerbate the retinal pathology. The consequences of early diabetic changes in retinal cells are primarily considered in this thesis. Aims: This thesis aims to investigate the effect of perivascular cells (Müller cells, RPE, pericytes) on retinal endothelial cell permeability using an established in vitro model. Methods: Immunohistochemistry, cell morphology and cell growth patterns were used to characterise primary bovine retinal cells (Müller cells, RPE, pericytes and endothelial cells). An in vitro model of the blood-retinal barrier was refined by coculturing retinal endothelial cells with perivascular cells (Müller cells or pericytes) on opposite sides of a permeable Transwell filter. The integrity of the barrier formed by endothelial cells was assessed by transendothelial electrical resistance (TEER) measurements. Functional characteristics of endothelial cells were compared with ultrastructural morphology to determine if different cell types have barrier-enhancing effects on endothelial cell cultures. Once the co-culture model was established, retinal endothelial cells and Müller cells were exposed to different environmental conditions (20% oxygen, normoxia; 1% oxygen, hypoxia) to examine the effect of perivascular cells on endothelial cell permeability under reduced oxygen conditions. Barrier integrity was assessed by TEER measurements and permeability was measured by passive diffusion of radiolabelled tracers from the luminal to the abluminal side of the endothelial cell barrier. A further study investigated the mechanism of laser therapy on re-establishment of retinal endothelial cell barrier integrity. Müller cells and RPE, that comprise the scar formed after laser photocoagulation, and control cells (Müller cells and pericytes, RPE cells and ECV304, an epithelial cell line) were grown in long-term culture and treated with blue-green argon laser. Lasered cells were placed underneath confluent retinal endothelial cells growing on a permeable filter, providing conditioned medium to the basal surface of endothelial cells. The effect of conditioned medium on endothelial cell permeability was determined, as above. Results: Co-cultures of retinal endothelial cells and Müller cells on opposite sides of a permeable filter showed that Müller cells can enhance the integrity of the endothelial cell barrier, most likely through soluble factors. Low basal resistances generated by endothelial cells from different retinal isolations may be the result of erratic growth characteristics (determined by ultrastructural studies) or the selection of vessel fragments without true ‘barrier characteristics’ in the isolation step. When Müller cells were co-cultured in close apposition to endothelial cells under normoxic conditions, the barrier integrity was enhanced and permeability was reduced. Under hypoxic conditions, Müller cells had a detrimental effect on the integrity of the endothelial cell barrier and permeability was increased in closely apposed cells. Conditioned medium from long-term cultured Müller cells and RPE that typically comprise the scar formed after lasering, enhanced TEER and reduced permeability of cultured endothelial cells. Conclusions: These studies confirm that bovine tissues can be used as a suitable model to investigate the role of perivascular cells on the permeability of retinal endothelial cells. The dual effect of Müller cells on the retinal endothelial cell barrier under different environmental conditions, underscores the critical role of Müller cells in regulating the blood-retinal barrier in health and disease. These studies also raise the possibility that soluble factor(s) secreted by Müller cells and RPE subsequent to laser treatment reduce the permeability of retinal vascular endothelium. Future studies to identify these factor(s) may have implications for the clinical treatment of macular oedema secondary to diseases including diabetic retinopathy.

Doctor of Philosophy (Medicine) / Background: Diabetic vascular complications affect both the macro- and microvasculature. Microvascular pathology in diabetes may be mediated by biochemical factors that precipitate cellular changes at both the gene and protein levels. In the diabetic retina, vascular pathology is found mainly in microvessels, including the retinal precapillary arterioles, capillaries and venules. Macular oedema secondary to breakdown of the inner blood-retinal barrier is the most common cause of vision impairment in diabetic retinopathy. Müller cells play a critical role in the trophic support of retinal neurons and blood vessels. In chronic diabetes, Müller cells are increasingly unable to maintain their supportive functions and may themselves undergo changes that exacerbate the retinal pathology. The consequences of early diabetic changes in retinal cells are primarily considered in this thesis. Aims: This thesis aims to investigate the effect of perivascular cells (Müller cells, RPE, pericytes) on retinal endothelial cell permeability using an established in vitro model. Methods: Immunohistochemistry, cell morphology and cell growth patterns were used to characterise primary bovine retinal cells (Müller cells, RPE, pericytes and endothelial cells). An in vitro model of the blood-retinal barrier was refined by coculturing retinal endothelial cells with perivascular cells (Müller cells or pericytes) on opposite sides of a permeable Transwell filter. The integrity of the barrier formed by endothelial cells was assessed by transendothelial electrical resistance (TEER) measurements. Functional characteristics of endothelial cells were compared with ultrastructural morphology to determine if different cell types have barrier-enhancing effects on endothelial cell cultures. Once the co-culture model was established, retinal endothelial cells and Müller cells were exposed to different environmental conditions (20% oxygen, normoxia; 1% oxygen, hypoxia) to examine the effect of perivascular cells on endothelial cell permeability under reduced oxygen conditions. Barrier integrity was assessed by TEER measurements and permeability was measured by passive diffusion of radiolabelled tracers from the luminal to the abluminal side of the endothelial cell barrier. A further study investigated the mechanism of laser therapy on re-establishment of retinal endothelial cell barrier integrity. Müller cells and RPE, that comprise the scar formed after laser photocoagulation, and control cells (Müller cells and pericytes, RPE cells and ECV304, an epithelial cell line) were grown in long-term culture and treated with blue-green argon laser. Lasered cells were placed underneath confluent retinal endothelial cells growing on a permeable filter, providing conditioned medium to the basal surface of endothelial cells. The effect of conditioned medium on endothelial cell permeability was determined, as above. Results: Co-cultures of retinal endothelial cells and Müller cells on opposite sides of a permeable filter showed that Müller cells can enhance the integrity of the endothelial cell barrier, most likely through soluble factors. Low basal resistances generated by endothelial cells from different retinal isolations may be the result of erratic growth characteristics (determined by ultrastructural studies) or the selection of vessel fragments without true ‘barrier characteristics’ in the isolation step. When Müller cells were co-cultured in close apposition to endothelial cells under normoxic conditions, the barrier integrity was enhanced and permeability was reduced. Under hypoxic conditions, Müller cells had a detrimental effect on the integrity of the endothelial cell barrier and permeability was increased in closely apposed cells. Conditioned medium from long-term cultured Müller cells and RPE that typically comprise the scar formed after lasering, enhanced TEER and reduced permeability of cultured endothelial cells. Conclusions: These studies confirm that bovine tissues can be used as a suitable model to investigate the role of perivascular cells on the permeability of retinal endothelial cells. The dual effect of Müller cells on the retinal endothelial cell barrier under different environmental conditions, underscores the critical role of Müller cells in regulating the blood-retinal barrier in health and disease. These studies also raise the possibility that soluble factor(s) secreted by Müller cells and RPE subsequent to laser treatment reduce the permeability of retinal vascular endothelium. Future studies to identify these factor(s) may have implications for the clinical treatment of macular oedema secondary to diseases including diabetic retinopathy.

A red, obligately halophilic Dunaliella species believed to be D. salina was isolated from the North Arm of the Great Salt Lake, Utah, and its optimum growth conditions were determined. The red pigmented Dunaliella species required an optimum NaCl concentration of 10%, temperature 28°C, and an illuminance of 7500 lux. Ammonium carbonate was preferred over potassium nitrate and ammonium chloride. Potassium nitrate was preferred over ammonium chloride. The average division (generation) time under the above conditions was 46.5 hours. The alga grown in ammonium carbonate showed a lower content of chlorophyll a compared to those grown in potassium nitrate and in amonium chloride. The concentration of carotenoids of the alga grown in ammonium carbonate was higher than those in potassium nitrate and in ammonium chloride.

Over the years, exemplar-based methods have yielded significant improvements over their model-based counterparts in image synthesis applications. Notably, texture synthesis algorithms using an exemplar-based approach have shown success where traditional stochastic methods failed. As an illustrative example, I will present an exemplar-based approach that yields substantial benefits for user-guided terrain synthesis using Digital Elevation Models (DEMs). This success is realized through exploitation of structural properties of natural terrain. In addition to their proliferation in the image synthesis domain, as annotated image datasets become increasingly available, exemplar-based methods are also gaining in popularity for image analysis applications. This thesis addresses the intersection between exemplar-based analysis and the problem of content-based image retrieval (CBIR). A basic problem in CBIR is the process by which the search criteria are refined by the user through the manipulation of returned exemplars. Exemplar-based analysis is particularly well-suited to query refinement due to its interpretability and the ease with which it can be incorporated into an interactive system. I investigate this connection in the domain of Computer-Assisted Diagnosis (CAD) of dermatological images. I demonstrate that exemplar-based approaches in CBIR can be effective for diagnosing pigmented skin lesions (PSLs). I will present an exemplar-based algorithm for segmenting PSLs in dermatoscopic images. In addition, I will present a generalized representation of dermoscopic features for detection and matching. This representation not only leads to an exemplar-based PSL diagnosis scheme, but it also enables us to realize interactive region-of-interest retrieval, which includes a relevance feedback mechanism to facilitate more flexible query-by-example analysis. Finally, I will assess the benefit of this CBIR-CAD approach through both quantitative evaluations and user studies.