Impact of bronchodilator therapy on exercise tolerance in COPD

Exercise tolerance is an important parameter in patients with COPD and a primary goal of treatment is to reduce dyspnea to facilitate physical activities and improve health-related quality of life. This review examines the link between expiratory flow limitation and dyspnea to explain the rationale for the use of bronchodilators and review the characteristics of different types of exercise tests, with specific focus on which tests are likely to show a response to bronchodilators. An earlier literature search of studies published up to 1999 assessed the effects of bronchodilatort therapy on dypsnea and exercise tolerance among patients with COPD. This current review examines the clinical evidence published since 1999. Thirty-one randomized studies of exercise tolerance associated with short- and long-acting β2-agonists and anticholinergics were identified. Evidence for the efficacy of bronchodilators in enhancing exercise capacity is often contradictory and possibly depends on the exercise test and study methodology. However, further studies should confirm the benefit of long-acting bronchodilators in improving spontaneous everyday physical activities

Retour au sport après une entorse de cheville

The return to play (RTP) is a continuum with 3 mains phases : the return to activity, the return to sport and finally the return to performance. In order to make decision during the process of return-to-play we should assess our patient and use quantitative values.Thèse de doctorat sur l'entorse de chevill

Reproduction, fat metabolism, and life span: what is the connection?

Reduced reproduction is associated with increased fat storage and prolonged life span in multiple organisms, but the underlying regulatory mechanisms remain poorly understood. Recent studies in several species provide evidence that reproduction, fat metabolism, and longevity are directly coupled. For instance, germline removal in the nematode Caenorhabditis elegans promotes longevity in part by modulating lipid metabolism through effects on fatty acid desaturation, lipolysis, and autophagy. Here, we review these recent studies and discuss the mechanisms by which reproduction modulates fat metabolism and life span. Elucidating the relationship between these processes could contribute to our understanding of age-related diseases including metabolic disorders

Assessment of ankle muscle fatigue with a destabilization tool : A comparative study between healthy and chronic ankle unstable subjects

editorial reviewedIntroduction : Lateral ankle sprain is the most common injury. Fatigue seems to play a role in this injury as it is also at the end of a match (soccer or rugby) that ankle sprain occur most often. The objective of this study was to evaluate the reproducibility of a fatigue strength test and to compare the scores between healthy subjects and subjects with chronic ankle instability (CAI). Method : A total of 19 healthy subjects and 11 CAI subjects performed a fatigue strength test on one leg support with a destabilizing sandal. Subjects were required to perform a maximum number of repetitions of the slow inversion and fast eversion. This test was performed on two occasions one week apart. Results : The relative reproducibility was very good for the healthy subjects (ICC = 0.95) and moderate for the CAI subjects (ICC = 0.58). The measurement error remained relatively variable and high (SEM = 2.06–4.10 and MDC = 5.70–11.4). Healthy subjects were significantly more resistant to fatigue than CAI subjects (P = 0.02). Conclusion : The fatigue test is reproducible. However, it seems that the failure of the test in some subjects may be related to motor disability unrelated to fatigue. Chronically unstable subjects have significantly lower fatigue resistance score than healthy subjects demonstrating the interest of the test in clinical practice. A threshold ≤ 8 repetitions is proposed as the limit for identifying a deficit.Introduction : L’entorse latérale de cheville est la blessure la plus fréquente. La fatigue semble jouer un rôle dans ce traumatisme car c’est aussi en fin de match (football, rugby, …) qu’elle se produit le plus souvent. L’objectif de cette étude est d’évaluer la reproductibilité d’un test de résistance à la fatigue et de comparer les scores entre des sujets sains et des sujets ayant une instabilité chronique de cheville (Chronic Ankle Instability). Méthode : Un total de 19 sujets sains et 11 sujets CAI ont réalisé un test de résistance à la fatigue en appui unipodal avec une chaussure de déstabilisation. Les sujets devaient réaliser un nombre maximal de répétitions d’inversion lente et d’éversion rapide. Ce test a été réalisé à deux reprises à une semaine d’intervalle. Résultats : La reproductibilité relative était très bonne pour les sujets sains (ICC = 0,95) et modérée pour les sujets CAI (ICC = 0,58). L’erreur de mesure reste cependant relativement variable et élevée (SEM = 2,06–4,10 et MDC = 5,70–11,4). Les sujets sains ont été significativement plus résistants à la fatigue que les sujets CAI (p = 0,02). Conclusion : Le test de résistance à la fatigue est reproductible. Toutefois, il est probable que l’arrêt du test puisse être parfois lié à une incapacité motrice sans lien avec la fatigue. Les sujets instables chroniques présentent une résistance à la fatigue significativement plus faible que les sujets sains démontrant l’intérêt du test en pratique clinique. Un seuil ≤ 8 répétitions est proposé comme limite pour identifier un déficit

Assessment of ankle muscle fatigue resistance with a destabilization tool

Background : L’entorse latérale de cheville est la blessure de cheville la plus fréquente. La fatigue semble jouer un rôle dans ce traumatisme car c’est en fin de match (de football ou le rugby) que l’entorse de cheville se produit le plus souvent. L’objectif de cette étude est d’évaluer la reproductibilité d’un test de résistance à la fatigue et d’analyser les différences des scores obtenus en fonction des caractéristiques de notre population. Matériel & Méthode : nous avons recruté 40 sujets volontaires actifs (25 hommes, 15femmes, 23.2±2.7ans) avec ou sans antécédent d’entorses. Ils ont réalisé un test de résistance à la fatigue en appui unipodal avec un outil de destabilisation Myolux®. Les sujets devaient réaliser un nombre maximal de répétitions d’inversion lente et d’éversion rapide. Ce test a été réalisé à deux reprises à une semaine d’intervalle. Des sous-catégories ont été formées dans notre population. Résultats : la reproductibilité relative était bonne ICC =0.80 [0.69-0.88] mais l’erreur de mesure était relativement élevée (SEM=4.85 et MDC :13.5). Une différence significative se dégage entre les sujets sains qui ont été statistiquement significativement meilleur que les sujets instables chroniques (p<0.02). Conclusion : Le test de résistance à la fatigue musculaire avec l’outil Myolux® est reproductible. Le nombre de répétitions du mouvement d’inversion/éversion semblent être plus faible chez des sujets avec une instabilité chronique de cheville, cependant pour objectiver une amélioration ou une différence entre les patients un écart de 14 répétitions est nécessaire.Background : Lateral ankle sprain is the most common ankle injury. Fatigue seems to play a role in this injury as it is at the end of a match (soccer or rugby) that ankle sprains occur most often. The objective of this study was to evaluate the reproducibility of a fatigue resistance test and to analyze the differences in the scores obtained according to the characteristics of our population. Material & Method: We recruited 40 active volunteers (25 men, 15 women, 23.2±2.7 years) with or without a history of sprains. They performed a unipodal support fatigue test with a Myolux® destabilization tool. The subjects had to perform a maximum number of repetitions of slow inversion and fast eversion. This test was performed twice at one week intervals. Subcategories were formed in our population. Results: The relative reproducibility was good ICC =0.80 [0.69-0.88] but the measurement error was relatively high (SEM=4.85 and MDC :13.5). A significant difference emerged between the healthy subjects who were statistically significantly better than the chronically unstable subjects (p<0.02). Conclusion: The muscle fatigue test with the Myolux® tool is reproducible. The number of repetitions of the inversion/eversion movement seems to be lower in subjects with chronic ankle instability, however to objectify an improvement or a difference between patients a difference of 14 repetitions is necessary

On the evolutionary origin of aging

It is generally believed that the first organisms did not age, and that aging thus evolved at some point in the history of life. When and why this transition occurred is a fundamental question in evolutionary biology. Recent reports of aging in bacteria suggest that aging predates the emergence of eukaryotes and originated in simple unicellular organisms. Here we use simple models to study why such organisms would evolve aging. These models show that the differentiation between an aging parent and a rejuvenated offspring readily evolves as a strategy to cope with damage that accumulates due to vital activities. We use measurements of the age-specific performance of individual bacteria to test the assumptions of the model, and find evidence that they are fulfilled. The mechanism that leads to aging is expected to operate in a wide range of organisms, suggesting that aging evolved early and repeatedly in the history of life. Aging might thus be a more fundamental aspect of cellular organisms than assumed so far