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Abstract(s)
O pâncreas é um órgão de elevada importância no organismo, uma vez que é ele que produz a insulina e impede assim o aparecimento da diabetes. O pâncreas tem variadas patologias associadas, sendo algumas de foro oncológico. Embora raros, os cancros do pâncreas estão comummente associados a elevadas taxas de mortalidade, uma vez que são detetados tardiamente e não se conhecem terapêuticas eficazes na atualidade. No campo da ótica médica, os estudos com o pâncreas são também escassos, o que mostra a necessidade de se intensificar a investigação para se poderem desenvolver procedimentos óticos para o diagnóstico e o tratamento de patologias. Neste sentido, e utilizando pâncreas de coelho, o presente trabalho consistiu na realização de medições óticas, nomeadamente pela técnica de espectrofotometria, para a determinação das propriedades óticas dos tecidos do pâncreas e para avaliar as propriedades de difusão da glicerina no seu interior. O desenvolvimento de futuros procedimentos que usem a luz para diagnosticar e/ou tratar doenças do pâncreas apenas será possível com o conhecimento das propriedades óticas numa banda espectral larga, como a que estudamos, desde o ultravioleta até ao infravermelho (200 – 1000 nm). Neste estudo, o coeficiente de absorção permitiu identificar a presença de dois pigmentos nos tecidos estudados – a melanina e a lipofuscina, pigmentos que estão associados ao envelhecimento dos tecidos. O objetivo do estudo das propriedades de difusão da glicerina (e da água) no pâncreas foi de recolher dados para se otimizarem futuros tratamentos de transparência a aplicar ao pâncreas para otimizar procedimentos óticos de diagnóstico e de tratamento no seu interior. As propriedades estudadas caracterizam os mecanismos de desidratação e de adaptação de índices de refração que criam os efeitos de transparência. Este estudo permitiu também avaliar o conteúdo de água móvel do pâncreas, até agora desconhecido, que se verificou semelhante ao de outros tecidos já estudados. Dado que os resultados obtidos são inovadores, espera-se que outros estudos, nomeadamente com tecidos patológicos do pâncreas, venham a seguir-se para que as tecnologias óticas possam ajudar no diagnóstico e no tratamento dessas doenças.
Pancreas is a highly important organ in human and animal physiology, due to the fact that it produces insulin and prevents the occurrence of diabetes. There are several pathologies associated with pancreas, some of them being oncologic. Although rare, the pancreas cancers are commonly associated with high death rates, since they are diagnosed at a later stage of development and also because no effective treatments are known today. Regarding biophotonics, the research with pancreas tissues is also scarce, meaning that new studies must be performed with the objective of developing new optical procedures to diagnose and treat pancreas pathologies. Bearing this in mind, and using rabbit pancreas, the present study consisted in performing optical measurements, namely with spectroscopy techniques, to determine the optical properties of the pancreas tissues and evaluate the diffusion properties of glycerol inside it. The development of future diagnostic/treatment procedures that use light will only be possible with the knowledge of pancreasʹ optical properties in a wide spectral range, like the one used in our studies, from the ultraviolet to the infrared (200 – 1000 nm). This study also allowed to identify the presence of two pigments in the pancreas – melanin and lipofuscin, pigments that are associated with the tissue ageing process. The objective of studying the diffusion properties of glycerol (and water) in pancreas was to retrieve data to optimize future optical clearing treatments that can be applied to enhance optical diagnostic/treatment procedures inside. The diffusion properties that were collected in our study characterize the dehydration and refractive index matching mechanisms of optical clearing. This study also allowed to evaluate the mobile water content in the pancreas, a value that was previously unknown and which was verified to be very similar to others already known for other tissues. Due to the innovative results obtained in the present work, we expect that further studies with pancreas, namely with pathological tissues, can be performed in the near future. Only that way, the optical technologies can be used in the development of noninvasive diagnostic or treatment procedures for pancreas diseases.
Pancreas is a highly important organ in human and animal physiology, due to the fact that it produces insulin and prevents the occurrence of diabetes. There are several pathologies associated with pancreas, some of them being oncologic. Although rare, the pancreas cancers are commonly associated with high death rates, since they are diagnosed at a later stage of development and also because no effective treatments are known today. Regarding biophotonics, the research with pancreas tissues is also scarce, meaning that new studies must be performed with the objective of developing new optical procedures to diagnose and treat pancreas pathologies. Bearing this in mind, and using rabbit pancreas, the present study consisted in performing optical measurements, namely with spectroscopy techniques, to determine the optical properties of the pancreas tissues and evaluate the diffusion properties of glycerol inside it. The development of future diagnostic/treatment procedures that use light will only be possible with the knowledge of pancreasʹ optical properties in a wide spectral range, like the one used in our studies, from the ultraviolet to the infrared (200 – 1000 nm). This study also allowed to identify the presence of two pigments in the pancreas – melanin and lipofuscin, pigments that are associated with the tissue ageing process. The objective of studying the diffusion properties of glycerol (and water) in pancreas was to retrieve data to optimize future optical clearing treatments that can be applied to enhance optical diagnostic/treatment procedures inside. The diffusion properties that were collected in our study characterize the dehydration and refractive index matching mechanisms of optical clearing. This study also allowed to evaluate the mobile water content in the pancreas, a value that was previously unknown and which was verified to be very similar to others already known for other tissues. Due to the innovative results obtained in the present work, we expect that further studies with pancreas, namely with pathological tissues, can be performed in the near future. Only that way, the optical technologies can be used in the development of noninvasive diagnostic or treatment procedures for pancreas diseases.
Description
Keywords
Tecido do pâncreas Índice de refração Reflexão interna total Dispersão do tecido Propriedades óticas Espetroscopia Transmitância total Transmitância colimada Refletância total Coeficiente de espalhamento Coeficiente de absorção Deteção de pigmentos Transparência ótica Coeficiente de difusão Desidratação de tecidos Adaptação de índices de refração Pancreas tissue Refractive index Total internal reflection Tissue dispersion Optical properties Spectroscopy Total transmittance Collimated transmittance Total reflectance Scattering coefficient Absorption coefficient Pigment detection Optical clearing Diffusion coefficient Tissue dehydration Refractive index matching