Made available in DSpace on 2014-06-11T19:23:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-27Bitstream added on 2014-06-13T20:30:35Z : No. of bitstreams: 1 albernaz_rm_me_jabo.pdf: 606225 bytes, checksum: fc8139f6f3b1c020259e97b3cecff7e3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A modalidade de rodeio denominada Prova do Laço de Bezerro tem sido questionada sobre a ocorrência de possíveis lesões nas vértebras cervicais ocasionadas pela tração da corda no pescoço dos bezerros. Neste trabalho avaliou-se 15 bezerros mestiços, machos ou fêmeas, entre cinco e seis meses de idade experimentalmente submetidos a prova do laço. Os animais foram laçados três vezes por semana, em dias alternados, durante cinco semanas, somando o total geral de 225 laçadas. A prova experimental foi realizada de forma semelhante à prova oficial, pelo mesmo cavaleiro profissional da modalidade. Os bezerros foram avaliados mediante exame clínico geral e neurológico ao início da primeira, durante a terceira e ao término da quinta semana experimental. Radiografias simples e contrastadas das vértebras cervicais foram efetuadas ao início da primeira e ao término da quinta semana de experimento. Os métodos de laçadas foram acompanhados e classificados qualitativamente em fortes ou fracos. Não foram encontradas alterações clínicas e radiográficas nos animais durante o experimento. O rigor da laçada foi considerado forte em 77% dos casos. O fato de não terem sido encontradas alterações clínicas e radiográficas indicam que a ocorrência de lesões cervicais em bezerros submetidos a prova de laço não é tão alta como o propalado, entretanto, trata-se de procedimento rude e agressivo. Número mais expressivo de experimentos semelhantes a este deverá ser conduzido tanto sob condições controladas como em provas reais para confirmar os dados da presente pesquisa. / The modality of roundup Calf Roping has been questioned on the occurrence of possible injuries in the cervical vertebrae caused by the rope tension in calfs neck. In this work 15 calves, male or female, ages varying from five and six months experimentally submitted to calf roping were evaluated. The procedure was carried through three times per week, in alternated days, during five weeks, adding the total of 225 lassoed. The experimental test was carried through of similar form to the official test, for the same professional knight of the modality. The calves had been evaluated by means of general and neurological clinical examination to the beginning of the first one, during third and to the ending of the fifth experimental week. Simple and contrasted x-rays of the cervical vertebrae had been made to the beginning of the first one and the ending of the fifth week of experiment. The lassoed methods had been observed and classified qualitatively in weak or strong. Clinical and radiographic alterations in the animais during the experiment had not been found. The severity of the lassoed was considered strong in 77% of the cases. The fact not to have been found clinical and radiographic abnormalities indicates that the occurrence of cervical injuries in calves submitted to calf roping is not as high as divulged, however, is about aggressive and rude procedure. Similar experiments must be made in such a way to be lead under controlled conditions as in real tests to confirm the data of the present research.

Orientador: José Corrêa de Lacerda Neto / Banca: Gelson Genaro / Banca: Claudia Acosta Duarte / Resumo: A modalidade de rodeio denominada Prova do Laço de Bezerro tem sido questionada sobre a ocorrência de possíveis lesões nas vértebras cervicais ocasionadas pela tração da corda no pescoço dos bezerros. Neste trabalho avaliou-se 15 bezerros mestiços, machos ou fêmeas, entre cinco e seis meses de idade experimentalmente submetidos a prova do laço. Os animais foram laçados três vezes por semana, em dias alternados, durante cinco semanas, somando o total geral de 225 laçadas. A prova experimental foi realizada de forma semelhante à prova oficial, pelo mesmo cavaleiro profissional da modalidade. Os bezerros foram avaliados mediante exame clínico geral e neurológico ao início da primeira, durante a terceira e ao término da quinta semana experimental. Radiografias simples e contrastadas das vértebras cervicais foram efetuadas ao início da primeira e ao término da quinta semana de experimento. Os métodos de laçadas foram acompanhados e classificados qualitativamente em fortes ou fracos. Não foram encontradas alterações clínicas e radiográficas nos animais durante o experimento. O rigor da laçada foi considerado forte em 77% dos casos. O fato de não terem sido encontradas alterações clínicas e radiográficas indicam que a ocorrência de lesões cervicais em bezerros submetidos a prova de laço não é tão alta como o propalado, entretanto, trata-se de procedimento rude e agressivo. Número mais expressivo de experimentos semelhantes a este deverá ser conduzido tanto sob condições controladas como em provas reais para confirmar os dados da presente pesquisa. / Abstract: The modality of roundup Calf Roping has been questioned on the occurrence of possible injuries in the cervical vertebrae caused by the rope tension in calfs neck. In this work 15 calves, male or female, ages varying from five and six months experimentally submitted to calf roping were evaluated. The procedure was carried through three times per week, in alternated days, during five weeks, adding the total of 225 lassoed. The experimental test was carried through of similar form to the official test, for the same professional knight of the modality. The calves had been evaluated by means of general and neurological clinical examination to the beginning of the first one, during third and to the ending of the fifth experimental week. Simple and contrasted x-rays of the cervical vertebrae had been made to the beginning of the first one and the ending of the fifth week of experiment. The lassoed methods had been observed and classified qualitatively in weak or strong. Clinical and radiographic alterations in the animais during the experiment had not been found. The severity of the lassoed was considered strong in 77% of the cases. The fact not to have been found clinical and radiographic abnormalities indicates that the occurrence of cervical injuries in calves submitted to calf roping is not as high as divulged, however, is about aggressive and rude procedure. Similar experiments must be made in such a way to be lead under controlled conditions as in real tests to confirm the data of the present research. / Mestre

Les maladies mitochondriales représentent un ensemble très divers de pathologies. Au cours de ce travail, j’ai abordé leur complexité dans deux situations différentes : les déficits humains en complexe III de la chaîne respiratoire mitochondriale et l’analyse des relations génotype/phénotype dans une cohorte de patients suspects de mutations sur un même gène nucléaire (POLG). Le complexe III joue un rôle central au sein de la chaîne respiratoire mitochondriale. Contrairement à sa caractérisation biochimique très complète, son rôle physiologique a été relativement mal établi. D'une cohorte de 2000 patients dont les activités de la chaîne respiratoire mitochondriale avaient été mesurées sur tissu hépatique ou musculaire, nous avons sélectionné 15 patients avec un déficit en complexe III pour lesquels nous disposions de fibroblastes exprimant un déficit respiratoire. L’origine génétique était initialement connue pour quatre des déficits (UQCRB, BCS1L x2, MT-CYB) et, au cours de ce projet, nous avons pu en identifier trois autres (CYC1, MT-CYB, LYRM7). Nous avons cherché à évaluer l'existence d'un lien entre le phénotype et les caractéristiques du déficit : gène impliqué, distribution tissulaire et profil des réponses cellulaires au déficit. Notre population de fibroblastes, hétérogène sur le plan génétique, s’est également révélée très variée quant aux conséquences biochimiques et cellulaires du déficit. Il ne semble donc pas exister de « profil type » des déficits en complexe III. Les atteintes liées à une mutation du gène POLG sont souvent considérées comme les maladies mitochondriales les plus fréquentes chez l’adulte. Elles sont associées à des présentations cliniques très diverses. Nous avons étudié la spécificité et la sensibilité des différents signes cliniques et biologiques considérés comme évocateurs et conduisant donc au séquençage de POLG. A cette fin, nous avons analysé rétrospectivement le phénotype clinique et les investigations mitochondriales chez 154 patients dont le séquençage du gène POLG avait été effectué révélant des mutations touchant les deux allèles du gène chez 34 patients, une seule mutation chez 10 patients et une séquence normale chez 110 patients. L’étude clinique a inclus les signes/symptômes cliniques, les données électrophysiologiques et l'imagerie cérébrale. Les investigations mitochondriales englobaient l’histologie musculaire, le dosage du lactate sanguin, la mesure des activités de la chaîne respiratoire et la recherche de délétions multiples de l’ADN mitochondrial musculaire. Cette étude a montré que les mutations du gène POLG étaient responsables de signes cliniques et paracliniques récurrents présentant donc une sensibilité et une spécificité, notamment en association, permettant de proposer un arbre décisionnel pour l’indication du séquençage du gène POLG. Cette étude a également permis d’établir l’histoire naturelle des maladies de l’adulte dues à des mutations délétères de POLG. En conclusion, la classification des maladies mitochondriales par une anomalie biochimique commune, un déficit en complexe III dans le cas présent, conduit à regrouper des atteintes très différentes, aussi bien sur le plan clinique que biochimique et cellulaire. Au contraire, même dans des affections réputées comme extrêmement diverses comme celles dues aux mutations du gène POLG, la classification par le gène atteint permet d’identifier des présentations récurrentes dans la classe d’âge étudiée, patients adultes dans le cas présent… / Mitochondrial diseases represent a very diverse set of pathologies. With this work, I approached their complexity in two different situations: phenotypic analysis of fibroblasts derived from patients with defects of the respiratory complex III and phenotypic analysis of a cohort of patients, the POLG gene of whom had been sequenced. The complex III plays a central role in the mitochondrial respiratory chain. Contrary to its complete biochemical characterization, its physiological role has been relatively poorly established. We selected 15 patients with complex III defect in liver and/or muscle and with fibroblasts expressing a respiratory defect. The genetic origin was initially known for four of these defects (UQCRB, BCS1L x2, MT- CYB) and during this project, we were able to identify three additional cases (CYC1, MT- CYB, LYRM7). We sought to assess the existence of a link between the disease phenotype and the defect characteristics: gene involved, tissue expression and cellular responses. Our population of fibroblasts, genetically heterogeneous, turned also to be diverse with respect to the biochemical and cellular consequences of the defect. A "typical" profile of complex III defect therefore does not seem to exist. Pathologies related to POLG mutations are often considered the most common mitochondrial diseases in adults. Their clinical presentation is very diverse. We have investigated the specificity and sensitivity of different clinical and biological signs considered as suggestive for POLG mutations and therefore leading to POLG sequencing. To that purpose, we retrospectively analyzed the clinical phenotype and mitochondrial investigations in 154 patients for which POLG had been sequenced revealing mutations affecting two alleles of the gene in 34 patients, one allele for 10 patients and a normal sequence for 110 patients. This study has shown that POLG mutations were responsible of recurrent clinical and paraclinical signs, whose sensitivity and specificity when considered in association allowed to propose a diagnostic flowchart for POLG sequencing. This study has also permitted to establish the natural story of diseases associated with deleterious POLG mutations in adults. In conclusion, classification of mitochondrial diseases by a common biochemical abnormality, a complex III defect in the present case, leads to group very different diseases that differ from their clinical, biochemical and cellular patterns. On the contrary, even in diseases considered highly diverse as those due to POLG mutations, classification by the affected gene allows to identify recurrent presentations in a population of adult patients with neurological presentation.

Image registration methods underpin many analysis techniques in neuroimaging. They are essential in group studies when images of different individuals or different modalities need to be brought into a common reference frame. This thesis explores the potential of brain connectivity- driven alignment and develops surface registration techniques for magnetic resonance imaging (MRI), which is a noninvasive neuroimaging tool for probing function and structure of the human brain. The first part of this work develops a novel surface registration framework, based on free mesh deformations, which aligns cortical and subcortical surfaces by matching structural connectivity patterns derived using probabilistic tractography (diffusion-weighted MRI). Structural, i.e. white matter, connectivity is a good predictor of functional specialisation and structural connectivity-driven registration can therefore be expected to enhance the alignment of functionally homologous areas across subjects. The second part validates developed methods for cortical surfaces. Resting State Networks are used in an innovative way to delineate several functionally distinct regions, which were then used to quantify connectivity-driven registration performance by measuring the inter- subject overlap before and after registration. Consequently, the proposed method is assessed using an independent imaging modality and the results are compared to results from state-of-the-art cortical geometry-driven surface registration methods. A connectivity-driven registration pipeline is also developed for, and applied to, the surfaces of subcortical structures such as the thalamus. It is carefully validated on a set of artificial test examples and compared to another novel surface registration paradigm based on spherical wavelets. The proposed registration pipeline is then used to explore the differences in the alignment of two groups of subjects, healthy controls and Alzheimer's disease patients, to a common template. Finally, we propose how functional connectivity can be used instead of structural connectivity for driving registrations, as well as how the surface-based framework can be extended to a volumetric one. Apart from providing the benefits such as the improved functional alignment, we hope that the research conducted in this thesis will also represent the basis for the development of templates of structural and functional brain connectivity.