[1] Univ Florence, Dept Anat Histol & Forens Med, I-50134 Florence, Italy
[2] Univ Florence, Dept Clin Physiopathol, I-50134 Florence, Italy
[3] CNR, Inst Complex Syst, Florence, Italy
[4] Univ Hosp Careggi, Dept Haematol, Cord Blood Bank, Florence, Italy