Cultured Red Blood Cells : Life Span in Vivo Study

To study the in vivo life span in healthy volunteers of red blood cells generated in vitro from autologous peripheral stem cells. The study will be carried out in 4 phases : * production in vitro of the equivalent of 1 ml of blood, i.e. 5x10e9 enucleated RBC from mononuclear cells isolated from an HSC graft obtained from a healthy volunteers donor. * labeling of these cRBC with 51 Cr * reinjection of the autologous cRBC * follow up of the receivers for a maximum 33 days to measure the half-life span of the injected cells.