Low-magnitude whole body vibration with resistive exercise as a countermeasure against cardiovascular deconditioning after 60 days of head-down bed rest

Whole body vibration with resistive exercise is a promising countermeasure against some weightlessness-induced dysfunctions. Our objective was to study whether the combination of low-magnitude whole body vibration with a resistive exercise can prevent the cardiovascular deconditioning induced by a nonstrict 60-day head-down bed rest (Earth Star International Bed Rest Experiment Project). Fourteen healthy men participated in this study. We recorded electrocardiograms and blood pressure waves by means of a noninvasive beat-by-beat measurement system (Cardiospace, integrated by Centre National d\u27Etudes Spatiales and Astronaut Center of China) during an orthostatic test (20 min of 75-degree head-up tilt test) before and immediately after bed rest. We estimated heart rate, blood pressure, cardiac output, stroke volume, total peripheral resistance, baroreflex sensitivity, and heart rate variability. Low-magnitude whole body vibration with resistive exercise prevented an increase of the sympathetic index (reflecting the sympathovagal balance of cardiac autonomic control) and limited the decrease of the spontaneous baroreflex sensitivity induced by 60 days of head-down bed rest. However, this countermeasure had very little effect on cardiac hemodynamics and did not improve the orthostatic tolerance. This combined countermeasure did not efficiently prevent orthostatic intolerance but prevents changes in the autonomic nervous system associated with cardiovascular deconditioning. The underlying mechanisms remain hypothetical but might involve cutaneous and muscular mechanoreceptors

Impact of inactivity and exercise on the vasculature in humans

The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct “vascular deconditioning and conditioning” effects which likely modify cardiovascular risk

Ethical considerations of the dynamics of clinical trials in an epidemic context: Studies on COVID-19

International audienceThe COVID-19 epidemic has led to the intense mobilization of all health professionals, including those involved in research. From the very beginning, research ethics committees (RECs) have been called upon and mobilized to carry out the scientific and ethical evaluations of research projects to achieve a sound analysis of their risk/benefit balance. The aim of this article is to present an ethical reflection on the challenges and consequences of the fast-track procedure for the evaluation of COVID-19 research projects in the context of a public health emergency. Indeed, a large number of protocols of reduced rigor were hastily prepared without collaboration between researchers and in the absence of national regulation. As a result, a number of ethical dilemmas have emerged concerning the opposing needs of pragmatism imposed by the emergency context and the ethical principles that should govern the conduct of research. Moreover, the dispersion of these individual projects, aggravated by excessive media coverage of specific treatments, has resulted in a weakened impact of the research in the epidemic context. This article provides suggestions for the ethical management of ongoing and upcoming research, giving RECs the opportunity to adapt their evaluations to avoid allowing the pragmatism of the emergency context to subvert the inviolability of the epistemological and ethical principles of research on humans. This reflection may strengthen the ethical basis for the formulation of their decisions

Candesartan but not erythropoietin restores pressure- induced vasodilation during severe diabetic neuropathy in mice

with the participation of The Australian Wound Management Association, The Japanese Society for Wound Healing, and the Australasian Wound and Tissue Repair SocietyInternational audienc