Rab4b Is a Small GTPase Involved in the Control of the Glucose Transporter GLUT4 Localization in Adipocyte

Endosomal small GTPases of the Rab family, among them Rab4a, play an essential role in the control of the glucose transporter GLUT4 trafficking, which is essential for insulin-mediated glucose uptake. We found that adipocytes also expressed Rab4b and we observed a consistent decrease in the expression of Rab4b mRNA in human and mice adipose tissue in obese diabetic states. These results led us to study this poorly characterized Rab member and its potential role in glucose transport.We used 3T3-L1 adipocytes to study by imaging approaches the localization of Rab4b and to determine the consequence of its down regulation on glucose uptake and endogenous GLUT4 location. We found that Rab4b was localized in endosomal structures in preadipocytes whereas in adipocytes it was localized in GLUT4 and in VAMP2-positive compartments, and also in endosomal compartments containing the transferrin receptor (TfR). When Rab4b expression was decreased with specific siRNAs by two fold, an extent similar to its decrease in obese diabetic subjects, we observed a small increase (25%) in basal deoxyglucose uptake and a more sustained increase (40%) in presence of submaximal and maximal insulin concentrations. This increase occurred without any change in GLUT4 and GLUT1 expression levels and in the insulin signaling pathways. Concomitantly, GLUT4 but not TfR amounts were increased at the plasma membrane of basal and insulin-stimulated adipocytes. GLUT4 seemed to be targeted towards its non-endosomal sequestration compartment.Taken our results together, we conclude that Rab4b is a new important player in the control of GLUT4 trafficking in adipocytes and speculate that difference in its expression in obese diabetic states could act as a compensatory effect to minimize the glucose transport defect in their adipocytes

Beyond cardio-vascular improvements: Cerebral oxygenation , cognitive functions, and HIIT

International audienc

Evaluation of medical students' expectations for multimedia teaching materials: Illustration by an original method using the evaluation of a web site on cardiovascular rehabilitation.

International audienceINTRODUCTION: Different multimedia tools have been developed to help medical students prepare for the National Ranking Examination (NRE), rendering their choice quite difficult. No study has specifically evaluated students' expectations regarding these materials. OBJECTIVES: To learn how medical students in Dijon assessed a website dedicated to cardiovascular rehabilitation, and collecting their suggestions in order to meet their expectations and the goals of second cycle medical studies. METHODS: Eighteen second-cyle students were evaluated in a semi-directed manner and in ecological situation, a website specifically designed for the national curricula on cardiovascular rehabilitation for obtaining the Diploma of Specialty Studies (DES) for physical medicine and rehabilitation (PM&R) residents. Students also had to fill out a pretest and a posttest (5 MCQs). RESULTS: The overall quality of the site was deemed satisfactory (65.6 ± 7.7 points/100). Medical information was considered better than non-medical data and site's design (respectively 84.8 ± 8.1, 61.1 ± 20 and 64.4 ± 14.9/100). Students found the site useful in terms of understanding the items related to cardiovascular rehabilitation, although they judged it not completely in line with the NRE goals. The average score increased significantly between the pre-and post-test (6.8 ± 0.8 vs. 5 ± 1.5/8, p<0.05). CONCLUSION: This site appears to be significantly useful for short-term knowledge improvement, but only partially meeting the expectations of second-cycle students. It seems relevant to study further possibilities for customizing and providing summarized learning for the NRE. These elements could serve as building grounds for the future version of this website

Cardiovascular rehabilitation

International audienceno abstrac

The Physiological Characteristics of an 83-Year-Old Champion Female Master Runner

International audiencePurpose: To examine the cardiorespiratory, muscular, and skeletal characteristics of an 83-year-old champion female master athlete (called DL in this study) who had set multiple world running records in the 80-to-84-year-old age group. Methods: Measures of maximal oxygen uptake, maximal heart rate, maximal isometric torque for knee extensor muscles, thigh and triceps surae muscle volumes, and bone mineral density (BMD) of the proximal femur region were evaluated. Based on previously published equations, physiological age was determined for maximal oxygen uptake, maximal heart rate, and maximal isometric torque. Muscle volumes for the dominant leg were compared with previously published sex- and age-matched data using z scores. For BMD, T score and z score were calculated. Results: DL had the highest maximal oxygen uptake (42.3 mL.min(-1)-kg(-1)) ever observed for a female older than 80 years of age, which gave her a remarkable physiological age (27 y). By contrast, she had a physiological age closer to her biological age for maximal isometric torque (90 y) and maximal heart rate (74 y). The z scores for thigh (0.4) and triceps surae (1.1) muscle volumes revealed that DL's leg muscles were affected almost as much as her sex- and age-matched peers. The T score (-1.7) for BMD showed that DL had osteopenia but no osteoporosis, and the z score (0.7) showed that DL's BMD was similar to that of females of the same age. Conclusion: This single case study shows that the remarkable cardiorespiratory fitness coupled with intensive endurance training observed in a female master athlete was not associated with specific preservation of her muscular and skeletal characteristics

Non-pharmacological strategies in cardiovascular prevention: 2011 highlights.

International audienceThe clinical efficacy of cardiac rehabilitation programs is clearly recognized. Yet, as regards the three main currently employed strategies (exercise, education, and psychobehavioral support), new ideas regularly appear, stemming from studies aimed at providing proof of their efficacy and innocuousness, along with optimal modes of prescription and, at times, their cost-benefit ratio. This ongoing work, which was initially developed in view of enriching the "What's new in?" section of the Sofmer website, represents a selection of articles that may be non-exhaustive, yet is maximally diversified and as representative as possible of the main 2011 highlights in the field of cardiovascular prevention. Each of the articles selected puts forward an original idea, confirms the existence of an effect that was suspected or has had some impact on clinical practice in the field of non-pharmacological management of cardiovascular disease. In line with the multidisciplinary approach of Physical Medicine and Rehabilitation (PMR), the Sofmer cardiovascular rehabilitation group has associated itself with a wide range of specialists (PMR, cardiologists, exercise physiologists, experts in the science and technology of physical activities), all of whom are involved in clinical research and the management of more and more patients. Our objective was consequently to compile a selection of commented articles most likely to interest the different operatives (doctors, nurses, physiotherapists, dietitians, adapted physical activity instructors, psychologists) working with these patients in rehabilitation units or in phase III associative structures. Their goals may vary: (1) learners may wish to further their knowledge of cardiac rehabilitation techniques; (2) practitioners may be interested in continued education but not have the time for regular bibliographic updates; (3) researchers may be intent on informing themselves on the latest breakthroughs and/or arousing their imagination...Enjoy your reading

''Validity of a questionnaire to assess the physical activity level in coronary artery disease patients''

Guiraud, Thibaut | Granger, Richard | Bousquet, Marc | Gremeaux, VincentInternational audience''The aim of the study is to compare, in coronary artery disease patients, physical activity (PA) assessed with the Dijon Physical Activity Questionnaire (DPAQ) and the true PA objectively measured using an accelerometer. Seventy patients wore an accelerometer (MyWellness Key actimeter) throughout 1 week after a cardiac rehabilitation program that included therapeutic education about regular PA. Patients completed the DPAQ at the end of the week. The mean weekly active energy expenditure was 619.9 +/- 374.6 kcal, and the mean DPAQ score was 21.3 +/- 3.1/30 points. There were low but significant correlations between total active energy expenditure and the DPAQ score (rho = 0.4, P = 0.009). There were no correlations between peak power output and total DPAQ score. The DPAQ significantly correlates with objective measures given by the MyWellness Key actimeter. The choice between these tools relies on the clinician's appreciation, taking into account patients' characteristics and goals as well as the cost of the method and availability of the tool. International Journal of Rehabilitation Research 35:270-274 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.'

How do general practitioners assess low back pain Web sites?

International audienceSTUDY DESIGN: Cross-sectional study of teaching general practitioners (TGPs) in the South of France. OBJECTIVE: To determine what TGPs think about francophone Internet sites dedicated to chronic low back pain (CLBP). SUMMARY OF BACKGROUND DATA: Patients with CLBP often seek medical information about their symptoms on the Internet. The quality of the information is usually poor. To date, the opinion of TGPs concerning the quality of CLBP Web sites remains unknown. METHODS: We invited the 112 TGPs in the Southern region to participate. The participants used an assessment scale to evaluate 7 Web sites about CLBP in semicontrolled conditions. The quality and the importance of the different types of information (medical, nonmedical) and the design were measured on a visual analog scale (0-100) and with the point-sharing method (scale of 0-10). RESULTS: In total, 47 TGPs responded. The median quality score for the 7 Web sites was 50 (range 30-79). The score for medical information was 52.5 (10-80), for nonmedical information it was 60.4 (20-90), and for design it was 56.4 (30-85). For nonmedical information, the median relative weight was 4, and for both medical information and design it was 3. CONCLUSION: French TGPs believe that CLBP Web sites should focus on nonmedical, practical advice; they consider the design at least as important as the medical information. This viewpoint seems to conflict in part with patients' expectations. Good-quality and interactive Web sites could reduce this discordance. A list of approved sites should be available for general practitioners to recommend to their patients, to supplement information given during the consultation

Muscle VO2 and forearm blood flow repeatability during venous and arterial occlusions in healthy and coronary heart disease subjects

International audienceThis study aims were: 1) to assess forearm blood flow (FBF) and muscle oxygen consumption (mVO(2)) repeatability assessed with near-infra red spectroscopy (NIRS) during venous occlusions (VO) in middle aged healthy subjects and patients with stable coronary heart disease (CHD), 2) to assess the agreement betweenmVO(2) calculated from NIRS signals duringVOand arterial occlusion (AO) in 18 middle aged healthy subjects and 12 patients with CHD. FBF andmVO(2) were measured using NIRS during 2 successive VO (1-min duration), followed by a 5-min AO. Repeatability for FBF and mVO(2) during VO was assessed with intra class correlation (ICC), coefficient of variation (CV %) and agreement between VO and AOmVO(2) was assessed with a Bland and Altman analysis. FBF and mVO(2) during VO were highly reproducible in healthy (FBF: ICC 0.73, CV% 9.75; mVO(2): ICC 0.89, CV% 12.6) and CHD subjects (FBF: ICC 0.95, CV% 10.26; mVO(2): ICC 0.98, CV% 7.92). VO and AO mVO(2) were in agreement in healthy (mean bias: 0.002mL O-2.min(-1).100g(-1)) and CHD subjects (mean bias: 0.014mL O-2.min(-1).100g(-1)). FBF and mVO(2) measured with NIRS during VO and/or AO are highly reproducible methods to assess microvascular function in healthy subjects and stable CHD patients

Barriers to physical activity in coronary artery disease patients: Development and validation of a new scale

International audienceOBJECTIVE:To develop and validate a self-report questionnaire to measure barriers to regular physical activity (PA) in patients with stable coronary artery disease (CAD).METHODS:Phase 1: 17 patients completed a semi-structured interview. After grouping and reformulating the reported barriers, their pertinence was reevaluated by the patients. Then, a decision algorithm was used to select items. A principal component analysis was performed to determine content validity. Phase 2: 49 patients completed the questionnaire resulting from phase 1 twice, 7 days apart, and questionnaires to evaluate depression, anxiety, and the level of physical activity. Construct validity was evaluated by analysis of Spearman's correlation coefficient between the total score for the questionnaire and a convergent dimension (anxiety), as well as a divergent dimension (Dijon physical activity score). Internal consistency was evaluated by Cronbach's alpha coefficient. Test-retest reliability was evaluated by the intraclass coefficient (ICC).RESULTS:Eleven items were selected after phase 1. The questionnaire presented good face validity and the content validity seemed satisfactory after analysis of the literature by the experts. Construct validity was moderate. Internal consistency was very good (Cronbach's α>0.81). Reproducibility was excellent with an ICC at 0.95. Feasibility was good with less than 3minutes to complete the questionnaire.CONCLUSION:This questionnaire presents good psychometric properties. A further prospective study should evaluate sensitivity to change and help determine a threshold value indicating the need for a specific behavioral strategy to alleviate barriers to physical activity in these patient