Introdução / Objetivos: O prognóstico do adenocarcinoma ampular pode ser influenciado por fatores como estadiamento e variáveis histopatológicas, como o padrão intestinal ou pancreatobiliar. O diagnóstico do padrão histopatológico pode ser auxiliado pela expressão de citoqueratinas, CK, 7 e 20 e do gene homeobox CDX2. O objetivo do estudo foi analisar associações entre características histopatológicas e sobrevida, e entre padrão histopatológico e expressão de CK7, CK20 e CDX2. Método: Estudo de coorte retrospectivo desenvolvido no Hospital de Clínicas de Porto Alegre entre 2000 e 2011. Foram avaliados dados histopatológicos, estadiamento pTNM, padrão histopatológico e expressão imunoistoquímica e sobrevida. Resultados: A amostra constou de 65 carcinomas ampulares (n = 65). Foi observado padrão intestinal em 46, pancreatobiliar em 16 e outros em três. Sobrevida em cinco anos após duodenopancreatectomia (n = 47) foi de 27%. Associaram-se à menor sobrevida na análise univariada: dois ou mais linfonodos metastáticos, razão de linfonodos, RL, maior ou igual a 20%; estágio IIB em relação a inferiores; tumor de alto grau; invasão linfovascular. Na análise multivariada, metástase linfonodal e RL ≥ 20% influenciaram sobrevida. Conclusões: O pior prognóstico foi associado à metástase linfonodal. Não foi observada associação entre padrão histopatológico e expressão imunoistoquímica. / Background / Objectives: The prognosis of patients with ampullary adenocarcinomas can be influenced by such factors as pTNM stage and histopathological variables, such as intestinal or pancreatobiliary patterns. The characterization of these patterns can be facilitated by the expression of cytokeratins 7 (CK7) and 20 (CK20) and caudal-related homeobox gene 2 (CDX2). The aim of the present study was to analyze the association between the histopathological characteristics and the survival of patients with ampullary adenocarcinomas, as well as the association between the histopathological patterns and CK7, CK20 and CDX2 expression. Methods: This retrospective cohort study was performed at the Clinics Hospital of Porto Alegre between 2000 and 2011 and examined the histopathological data, pTNM stage, histopathological patterns, immunohistochemical expression patterns and survival of patients with ampullary adenocarcinomas. Results: The sample patient population consisted of 65 ampullary carcinomas. Of these carcinoma samples, an intestinal pattern was observed for 46, a pancreatobiliary pattern was observed for 16 and other patterns were observed 3 of the samples. The 5-year survival rate for patients following pancreaticoduodenectomy (n = 47) was 27%. From the univariate analysis, the following variables were associated with shorter survival times: the presence of 2 or more metastatic lymph nodes; positive lymph node ratio (LR) ≥ 20%; stage IIB or greater; high-grade tumors; and lymphovascular invasion. From the multivariate analysis, lymph node metastases and a LR ≥ 20% were shown to influence survival significantly. Conclusions: Lymph node metastases were associated with poor patient prognoses, although no association was found between the histopathological pattern and immunohistochemical expression.

The main target of this work is a design of the program for border localization of the optic disc in OCT data. Part of this program is also localization of the „optic cup“ and calculation of several values that characterize optic disc. The work is also dealing with a description of the optical coherence tomography principle which is used in ophthalmology. One chapter describes some published methods of optic cup localization. Success of the program and its comparison with OCT Zeiss Stratus 3000 is evaluated at the end of the work.

Afin de résoudre la problématique des substituts osseux faiblement vascularisés, un des challenges majeurs en ingénierie tissulaire osseuse est de favoriser le développement précoce d’une microvascularisation. La reproduction du microenvironnement local et l’organisation cellulaire in situ sont des approches innovantes pour optimiser la formation osseuse. En Biofabrication, la Bioimpression Assistée par Laser (LAB) est une technologie émergente permettant l’impression de cellules et de biomatériaux avec une résolution micrométrique. L’objectif de ce travail était d’étudier l’effet de l’organisation de la pré-vascularisation par LAB sur la régénération osseuse. La station de bioimpression Novalase a été utilisée pour imprimer des motifs de cellules endothéliales sur un « biopaper » constitué de collagène et de cellules souches issues de la papille apicale. Les paramètres d’impression, densités cellulaires et conditions de recouvrement ont été optimisés afin de favoriser la formation d’un réseau microvasculaire avec une architecture définie in vitro. Ce modèle a ensuite été transposé in vivo, grâce à la bioimpression in situ de cellules endothéliales au niveau de défauts osseux critiques chez la souris, afin d’évaluer si la prévascularisation organisée par LAB permettait de promouvoir et contrôler spatialement le processus de régénération osseuse. Les résultats ont montré que la bioimpression permettait d’augmenter la densité de vaisseaux dans les défauts osseux et de favoriser la régénération osseuse. / In order to solve the issue of poorly vascularized bone substitutes, development of a microvasculature into tissue-engineered bone substitutes represents a current challenge. The reproduction of local microenvironment and in situ organization of cells are innovating approaches to optimize bone formation. In Biofabrication, Laser-Assisted Bioprinting (LAB) has emerged as a relevant method to print living cells and biomaterials with micrometric resolution. The aim of this work was to study the effect of prevascularization organized by LAB on bone regeneration. The laser workstation Novalase was used to print patterns of endothelial cells onto a « biopaper » of collagen hydrogel seeded with stem cells from the apical papilla. Printing parameters, cell densities and overlay conditions were optimized to enhance the formation of microvascular networks with a defined architecture in vitro. This model was then transposed in vivo, through in situ bioprinting of endothelial cells into mouse calvarial bone defects of critical size, to investigate if prevascularization organized by LAB can promote and spatially control bone regeneration. The results showed that bioprinting allowed to increase blood vessel density in bone defects and promote bone regeneration.