Pathogenèse de l’hépatite autoimmune : influence des gènes, du sexe, de l’âge et de l’environnement

L’hépatite autoimmune (HAI) résulte d’une perte de tolérance du système immunitaire envers des antigènes de l’hépatocyte. Elle peut se présenter sous forme d’hépatite aiguë, parfois fulminante, ou comme une maladie chronique menant progressivement à une cirrhose hépatique. En absence de traitement, cette maladie est fatale. La pathogenèse de l’HAI et les mécanismes responsables de sa progression restent inconnus à ce jour. L’objectif global de ce projet est d’examiner les facteurs prédisposants et les mécanismes immunologiques responsables de l’apparition et de la progression de l’HAI. Pour permettre l’étude de la pathogenèse de l’HAI, nous avons développé un modèle murin expérimental d’hépatite autoimmune de type 2. Celui-ci est basé sur la xénoimmunisation de souris C57BL/6 avec les deux antigènes ciblés dans l’HAI de type 2 chez l’homme (CYP2D6 et FTCD). Par mimétisme moléculaire, le système immunitaire de ces souris réagit contre les protéines murines homologues et une HAI s’ensuit. Ce modèle expérimental présente la plupart des caractéristiques histologiques, biochimiques et sérologiques d’une HAI de type 2. Les souris développent une inflammation autoimmune chronique avec présence d’hépatite d’interface et d’infiltrations intralobulaires, un infiltrat composé majoritairement de lymphocytes T CD4+ mais aussi de lymphocytes T CD8+ et B, d’une élévation des ALT sériques, des niveaux d’immunoglobulines G circulantes augmentés ainsi que d’autoanticorps anti-LKM1 et anti-LC1. L’étude de l’influence du bagage génétique a permis de définir l’importance relative des gènes du CMH et des gènes non-CMH sur le développement d’une HAI. Les gènes du locus CMH sont essentiels mais insuffisants pour mener au développement d’une HAI et donc, la susceptibilité génétique à l’HAI est comme chez l’homme, multigénique. Les patients atteints d’HAI de type 2 sont généralement des jeunes filles. L’étude des influences de l’âge et du sexe dans ce modèle a permis de montrer que les souris femelles avant et au début de leur maturité sexuelle sont plus susceptibles au développement d’une HAI de type 2. De plus, les femelles ont un nombre réduit de lymphocytes T régulateurs, ce qui leur confère une susceptibilité accrue comparé aux mâles. L’ensemble de ces travaux nous a conduits à proposer un mécanisme où le développement d’une HAI chez les femelles d’un âge particulier résulterait de l’activation de cellules T CD4+ autoréactives ayant échappé aux mécanismes de tolérance centrale, via un mécanisme de mimétisme moléculaire avec un antigène exogène. En présence d’une tolérance périphérique réduite due à un faible nombre de cellules T régulatrices, les cellules T autoréactives proliféreraient et activeraient des cellules B autoréactives entraînant la sécrétion d’autoanticorps. L’activation subséquente de cellules T CD8+ cytotoxiques spécifiques amènerait la lyse des hépatocytes et la relâche d’autoantigènes permettant la perpétuation de l’autoimmunité.

Étude de l'autoimmunité contre le foie induite par mimétisme moléculaire

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Efeitos de tarefas cognitivas no controle postural de idosos: Uma revisão sistemática

Demanding attention in order to keep postural balance increases with aging and with the presence of concurrent tasks that require information processing. Several studies have demonstrated that motor performance can be related to the complexity of the task and aging process, presenting a possible interaction between these factors. The aim of this review was to identify and analyze published papers about the effects of cognitive tasks on the postural control of elderly individuals. A systematic search in the Web of Science, SportDiscus, CINAHL, Science Direct on line, Biological Abstracts, PsycINFO, and Medline databases was made and 444 articles were found. Eight were selected that studied the variables of interest. These studies showed that postural control seems to be influenced by the individual's attention processes and that deficits in such ability may be associated to an increased risk of falls. © FTCD/CIDESD.

Etapas e volume de treinamento das ginastas Brasileiras participantes de Jogos Olímpicos (1980-2004)

Results from Brazilian female Artistic Gymnastics improved over the past 10 years at an international level of competition. This study aimed at describing career development process in sports through a qualitative research resorting to the Oral History method. Ten Brazilian gymnast players in Olympic Games from 1980 to 2004 participated in the study. The information they provided allowed for the identification of specific variables present in their long term preparation: structure and organization of their practice, duration of the preliminary preparation phases, volume of daily practice in different phases of training, and length of time for the achievement of better results. © FTCD/CIDESD.

Artes marciais, formação profissional e escolas de ofício: Análise documental do judô Brasileiro

The aim of this research was to describe the process of professional education of judo coaches in Brazil. In order to do this, documental sources were used as means of data collection. Results showed that highly regarded institutions such as Confederação Brasileira de Judô, Federação Paulista de Judô, and Liga Paulista de Judô all support educational structures that resembles the apprenticeship system, that is, education which provide mostly employment-preparation skills for trained labour, in detriment of education on the application of scientific principles aiming at improving sporting performance. In conclusion, Brazilian judo seems to be kept away from the academic formation model and linked to the know how to do traditions. © FTCD/CIDESD.

Insulina pancreática de ratos diabéticos tipo 1 submetidos a um protocolo de treinamento físico individualizado

Since diabetes mellitus is considered a world public health problem, the present study aimed to evaluate oral glucose tolerance (TTGo) and pancreatic insulin concentration (PIC) of type I diabetic rats subjected to an individualized exercise training protocol. A total of 40 adult Wistar rats were used, half of which induced to diabetes by alloxan (32 mg/kg) endovenous injection, and divided into four groups (10 per group): Sedentary Control (SC), Trained Control (TC), Sedentary Diabetic (SD) and Trained Diabetic (TD). The physical training consisted of swimming, 1 h/day, 5 days/week during 8 weeks, supporting overload equivalent to 90% of the individual anaerobic/aerobic metabolic transition determined at the beginning of the experiment. The rats of SD and TD groups presented body weight reduction in relation to controls, which was less accentuated in TD group. Water and food ingestion increased in the diabetic groups in relation to controls. The areas under the serum glucose curve during the GTTo of diabetic groups were higher than the controls. Physical training attenuated this elevation. The diabetic groups showed reduced PIC when compared to both control groups. The physical training protocol employed improved glucose homeostasis and attenuated the body weight loss of diabetic animals but did not alter pancreatic insulin concentration. © FTCD/FIP-MOC.

Perceived quality of life and physical activity in Brazilian older adults

The purpose of this study was to investigate the association between self-perceived quality of life and physical activity in Brazilian older adults. We investigated 199 individuals (117 men and 82 women) aged between 60 to 70 years old, employees of a public university. Physical activity was estimated by the short version of the International Physical Activity Questionnaire (IPAQ). Self-perceived quality of life was assessed using the World Health Organization Quality of Life (WHOQOL-Bref) questionnaire composed of four domains: physical, psychological, social relationship and environment. There was no difference in self-perceived quality of life between men and women. In contrast, quality of life was associated with physical activity even after adjustment for gender, schooling and income. The physical domain presented the strongest association with physical inactivity (Odds Ratio = 2.70, 95% CI 1.87-3.52). Only the environment domain evaluated by WHOQOL-Bref was not associated to physical inactivity. Among the older, improved self-perceived quality of life is positively associated to physical activity. © FTCD/FIP-MOC.

Autoeficácia para a prática de atividade física por indivíduos adultos

Self-efficacy to regular practice of physical activity (PA) can be defined as the ability to keep practicing exercises even with some obstacles that could appear. It is constituted through the influence of 4 main sources: mastery experiences, vicarious experiences, social persuasion and physiological and affective states. The aim of the study was to measure the level of self-efficacy to the regular practice of PA, its construction sources and correlate the level of self-efficacy with each one of the sources. An amount of 196 practitioners of PA took part in this study. The results showed that the level of self-efficacy was 111.19 points in scale that can range from 18 to 162 points. The most prominent source in the construction of self-efficacy was the social persuasion, with an average of 27.64 points in scale that can range from 4 to 36 points. For the correlations, it was used the Pearson coefficient (r). Mastery experiences stood out among the other sources (r = .30). The results agree with the literature, establishing the importance of the encouragement of close people in the maintenance of the behavior to practice PA, as well as to observe positive models, success experiences and feel comfortable during the exercises. © FTCD/FIP-MOC.

Lesão esportiva: Um estudo sobre a síndrome dolorosa femoropatelar

The patellofemoral pain syndrome (PFPS) is defined as a retropatellar or anterior knee pain, without another disease. It affects until 25% of the population, being more common in women and trained persons. As others pathologies, PFPS have been affected the training of elite and amateurs athletes. Thereby, the general purpose of this study was discuss the occurrence of PFPS as a sports injury, there prevention possibilities and the appropriate recovery training after injury. It had been developed a literature review addressing the specific characteristics of the syndrome, its diagnosis, its target population, its development, how it affects the training and which are their possibilities of prevention and treatment. © FTCD/FIP-MOC.

Análise do equilíbrio postural de indivíduos diabéticos por meio de baropodometria

Objective of this study was to analyze the postural balance of neuropathic diabetic individuals through baropodometry, related to losses in the sensorimotor system. Twenty-eight healthy and 25 diagnosed with diabetic neuropathy were subjected to static evaluation (measurement of displacement of body center of pressure) and dynamic (temporal analysis of the stance phase of gait cycle). The tactile sensitivity of the feet was assessed by Semmes Weinstein monofilaments and isometric muscle strength of ankle dynamometry. Analyses of multivariânvia (MANOVAs) and variance (ANOVAs) indicated lower performance in tactile sensitivity, muscle strength and dynamic balance, but showed no difference for static equilibrium of diabetic neuropathy. With this study by regression analysis, one can infer that the equilibrium differences in gait of neuropathic insensitivity may result from tactile and muscle strength. © FTCD/FIP-MOC.

Perfil antropométrico e fisiológico de atletas de futsal da categoria sub-20 e adulta

The aim of this study was to determine the anthropometrical and physiological profile of futsal players and compare between under-20 and adults categories. Twenty four male athletes futsal participated in the study. They played in two teams of futsal-level state: a team with players under-20 (12 athletes); and another with players of the adults category (12 athletes). The participants performed a routine assessment involving anthropometric measurements (body mass, size, thickness of skin folds, perimeter body and bone diameter) and tests to estimate the aerobic and anaerobic capacity. The results did not indicate differences in relation to the anthropometrical and physiological profile between the under-20 and adults categories. We concluded that the promotion of athletes from the under-20 category for the adult's category taking into account the anthropometrical profile and aerobic and anaerobic performance indicators is recommended. However, other indicators, such as the technical, tactical and psychological aspects are important to help in understanding this promotion phase and in the training. © FTCD/FIP-MOC.

Preconceito e esportes de aventura: A (não) presença feminina

Participation in adventure sports have increased recently, perhaps because of its appealing and emotional aspects. Despite this overall increase, women's participation is restricted due to ingrained gender prejudice in society, however, there are some initiatives aimed at expanding women's participation in several adventure sports. In scientific literature there is a lack of studies on adventure sports, especially on gender issues, prejudice and female athletic performance. These aspects motivated this study, which aims to investigate from the female athletes' perspective; the prejudice and behaviors of male athletes when in their presence and the male athletes' acceptance of them. This exploratory research consists of a qualitative study developed through an open on-line questionnaire. This tool was posted on web logs and websites of sixteen well-known female Brazilian adventure sports athletes. The questionnaire answers were analyzed based on the Thematic Content Analysis Technique and indicate that, although most female athletes do not report the prejudice and rejection of men, these attitudes appear subliminally, deserving more attention in future studies. © FTCD/FIP-MOC.

A influência da dança na percepção de estruturas rítmicas monotônicas em adolescentes surdos

Dance activities were administered to a group of deaf adolescents via visual and auditory stimuli in order to improve their perceptions of monotonic rhythmic structures. Status of psychomotor development was also assessed before and after participation in the program. Twenty deaf adolescents (ages between 12 and 13 years) were divided into two groups, experimental (EG) and control (CG). Before and after participating in the program for 26 weeks, participants were evaluated in rhythmical tasks adapted from the classical test of M. Stambak. The tasks included the perception of drum beats, actually viewed hit movements, or heard via a sound amplifier. Psychomotor tests were administered only to the EG. The period of practice with dance activities changed the individuals' performance in the monotonic rhythmic test. Also, the success rate improved in both, visual and auditory input tasks. Individuals in the CG showed no changes in performance. For the EG, in the post-test, the status of psychomotor development was six months below the target age of the tests (i.e., 11 years). Findings suggested that dance activities can change deaf individuals' auditory perception of rhythmic structures. Participation in such a program can also positively affect psychomotor development. © FTCD/FIP-MOC.

Determination of hemispheric dominance with mental rotation using functional transcranial Doppler sonography and FMRI

the aim of this study was to investigate specific activation patterns and potential gender differences during mental rotation and to investigate whether functional magnetic resonance imaging (fMRI) and functional transcranial Doppler sonography (fTCD) lateralize hemispheric dominance concordantly.