In vitrodifferentiation of human cardiac fibroblasts into myofibroblasts: characterization using electrical impedance.

Cardiac arrhythmias represent about 50% of the cardiovascular diseases which are the first cause of mortality in the world. Implantable medical devices play a major role for treating these arrhythmias. Nevertheless the leads induce an unwanted biological phenomenon called fibrosis. This phenomenon begins at a cellular level and is effective at a macroscopic scale causing tissue remodelling with a local modification of the active cardiac tissue. Fibrosis mechanism is complex but at the cellular level, it mainly consists in cardiac fibroblasts activation and differentiation into myofibroblasts. We developed a simplifiedin vitromodel of cardiac fibrosis, with human cardiac fibroblasts whom differentiation into myofibroblasts was promoted with TGF-ß1. Our study addresses an unreported impedance-based method for real-time monitoring ofin vitrocardiac fibrosis. The objective was to study whether the differentiation of cardiac fibroblasts in myofibroblasts had a specific signature on the cell index, an impedance-based feature measured by the xCELLigence system. Primary human cardiac fibroblasts were cultured along 6 days, with or without laminin coating, to study the role of this adhesion protein in cultures long-term maintenance. The cultures were characterized in the presence or absence of TGF-ß1 and we obtained a significant cell index signature specific to the human cardiac fibroblasts differentiation.

[Hemiplegia and a hiking tour of Mont Blanc: from hope to reality]. / Hémiplégie et tour du Mont Blanc: de l'espoir à la réalité.

INTRODUCTION: At the end of an endurance training program for stroke patients with hemiplegia, we offered a hiking tour around the Mont Blanc Pedestrian Tour. We found no publication describing a similar experience and no scientific data in the literature to determine the physiological characteristics required for this performance, particularly regarding cardiac and vascular capacities, level of impairment, and functional abilities. OBJECTIVE: To complete a part of the Mont Blanc Pedestrian Tour over six days, with a group of adults with hemiparesis and aphasia due to stroke. POPULATION: Seven of 20 subjects with right hemiparesis and aphasia were selected on the basis of results of physiological tests, after an endurance training program and two tests hikes at medium altitude. Mean age was 51.71 +/- 7.13 years, mean VO(2max) 19.76 +/- 3.46 ml.g(-1).mm(-1), mean P(max) 90 +/- 22.68 and mean walking speed 3.60 +/- 1.30 km/hour. ORGANIZATION: Organization involved setting up the itinerary, recruiting accompanying personnel (9 people), and arranging security. No specific adaptations for accessibility were available, and no specific equipment was used, except for standard walking sticks. RESULTS: During this pedestrian tour, the subjects demonstrated strong motivation, as well as exceptional physical and functional performance, despite significant changes in elevation (up to 1500 m per day) and long walking times (from 5 to 9 hours per day). DISCUSSION: This experience has enriched our reflection about the medical, functional, and psychological conditions required for this type of physical effort, both from patients and accompanying personnel. In the absence of reports on similar experiences with this patient population, we thought it interesting, six months after this challenge, to present our observations as well as the patients' point of view. This may encourage other rehabilitation teams to offer intensive walking activities for stroke patients.