The purpose of this clinical trial is to investigate the safety of human placental-derived
stem cells (HPDSC) given in conjunction with umbilical cord blood (UCB) stem cells in
patients with various malignant or nonmalignant disorders who require a stem cell transplant.
Patients will get either full dose (high-intensity) or lower dose (low intensity) chemo- and
immunotherapy followed by a stem cell transplantation with UCB and HPDSC.