1. National Cancer Institute (INCA), Bone Marrow Transplantation Center (CEMO), Laboratory Division, 20230-130 Rio de Janeiro, RJ, Brazil
2. Mathematics and Statistics Institute, Federal Fluminense University (UFF), 24020-140 Niterói, RJ, Brazil
3. State University of Rio de Janeiro (UERJ), Roberto Alcântara Gomes Biology Institute, Department of Biophysics and Biometrics, 20551-030 Rio de Janeiro, RJ, Brazil