El uso de modelos animales constituye una herramienta esencial para investigar la etiología y patogenia de la diabetes, así como para desarrollar tratamientos efectivos: el transplante de islotes pancreáticos o ingeniería genética. El éxito de estas terapias depende en gran medida de la correcta elección de la vía de administración. Objetivos: 1.- Estudiar la anatomía e histología del páncreas porcino; 2.- Describir la anatomía seccional de la región pancreática mediante RM y secciones anatómicas plastinadas; 3.- Confirmar que las arterias pancreáticas terminales en el cerdo constituyen una ruta potencial para la administración selectiva mediante técnicas endovasculares mínimamente invasivas.Diseño de la investigación y métodos: Cerdos Large White jóvenes fueron examinados con RM y posteriormente sacrificados de forma humanitaria. Criosecciones transversales finas (2-3 mm) en las que se interesaba el páncreas fueron plastinadas mediante el método E-12 (Biodur®). 19 páncreas se procesaron para el estudio histológico. El análisis vascular de las ramas terminales del páncreas se realizó mediante la inyección de ocho cadáveres de cerdo con resina epoxy. En 20 cerdos vivos se llevaron a cabo angiografías superselectivas en ramas terminales.Resultados: El porcentaje y tamaño de los islotes de parénquima endocrino fueron mayores en el lóbulo derecho que en el resto del páncreas. Las secciones a nivel de la vértebra T15 interesaron las mayores áreas del páncreas, en concreto el lóbulo izquierdo. Una rama pancreática terminal de la arteria esplénica se presentó en todos los animales. Conclusión: se ha desarrollado un valioso abordaje mínimamente invasivo al páncreas porcino. Ello puede contribuir al ensayo de nuevas terapias para diabetes en este modelo animal. No obstante, nuevos estudios se hacen necesarios para poder evaluar la eficacia del abordaje referido en terapia para diabetes. / Animal models are essential tools for investigating the etiology and pathogenesis of diabetes and for the development of effective treatments: islet transplantation or genetic engineering. Successful of these new therapies will depend on the appropriate choice of the route of administration. Objectives: 1. Study the anatomy and histology of the porcine pancreas; 2. Describe the normal sectional anatomy of the pig pancreatic region by MRI and plastinated anatomic sections; 3. Confirm that the pancreatic terminal arteries in pigs are a potential route for the selective delivery of islet cells or gene products to the pancreas by minimally invasive endovascular techniques. Research design and methods: Large White juvenile pigs were examined by MRI and then euthanized according to human procedure. Thin transversal cryosections (2-3mm) containing the pancreas were plastinated by the E12 method (Biodur®). 19 pancreases were process for histology study. Anatomic vascular study of pancreatic terminal arteries was obtained by epoxy resin injection of eight pig cadavers. Super selective angiography in the pancreatic terminal branch was conducted in vivo in 20 pigs. Results: Frequency and size of endocrine parenchyma islets was higher in right lobe of the pancreas than in the rest of the pancreas. Sections at the level of vertebra T15 showed the highest areas of pancreas and were related with left lobe. A constant pancreatic terminal branch from the splenic artery was present in all animals. Conclusion: a valuable minimally invasive approach to the porcine pancreas has been developed. It may contribute to assay new diabetes therapies in swine models. Further studies are needed to examine the specific efficiency of this approach in diabetes therapies.

This paper highlights two methods of examining the bovine pancreas by means of ultrasound, with a view to identifying advantages and disadvantages of the two techniques as well as testing and comparing their practicability. The goal is to evaluate the applicability of this intraoperative procedure to large animals - it is quite commonly used on humans - as well as present the resulting findings with regard to the ultrasonographic anatomy of the bovine pancreas. The sample consisted of 15 female beef cattle, none of which displayed evidence of any pancreatopathy based on their medical history, clinical examinations, and laboratory diagnostic testing. Transcutaneous and intraoperative sonographic examinations were performed on all 15 animals.

The effects of two types of cryopreservation, conventional freezing and vitrification, on the in vitro and in vivo function of a pancreatic substitute were investigated. Conventional freezing uses low concentrations of cryoprotective agents (CPAs), slow cooling and rapid warming and allows ice formation. Vitrification requires high concentrations of CPAs coupled with rapid cooling and warming to achieve a vitreous, or ice-free, state. A previously published mathematical model describing the mass transfer of CPAs through the alginate matrix of the substitute and the cell membrane was expanded to incorporate heat transfer as well as CPA cytotoxicity. Our results indicate that temperature of exposure is the most critical parameter for the proper design of CPA addition and removal protocols. The use of a mathematical model is critical to ensure CPA equilibration and minimize CPA exposure. Properly designed CPA addition and removal protocols were used for vitrification. The effects of cryopreservation on the biomaterial and the cellular function of a pancreatic substitute consisting of murine insulinomas encapsulated in calcium alginate/poly-L-lysine/alginate beads were assessed. In vitro results indicate that both vitrification and conventionally frozen perform comparably to fresh. However, in vivo studies reveal that vitrified beads perform worse than both conventionally frozen and fresh beads. With adjustments, it may be possible to improve the performance of the vitrified beads. Nevertheless, for this pancreatic substitute, conventional freezing is the better method and allows successful cryopreservation.

Thesis (Ph.D.)--University of Alberta, 2009. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Oncology. Title from pdf file main screen (viewed on January 30, 2010). Includes bibliographical references.

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Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.