Efficacy and safety of ex vivo cultured adult human mesenchymal stem cells (Prochymal) in pediatric patients with severe refractory acute graft-versus-host disease in a compassionate use study - Prasad, V K; Lucas, K G; Kleiner, G I; Talano, J A; Jacobsohn, D; Broadwater, G; Monroy, R; Kurtzberg, J (Biol Blood Marrow Transplant, 2011)