[1] Univ Florence, Dept Hlth Sci, Viale Pieraccini 6, I-50139 Florence, Italy
[2] Univ Bath, Dept Biol & Biochem, Bath BA2 7AY, Avon, England
[3] Univ Siena, Dept Med Surg & Neurosci, Med Oncol Unit, Siena, Italy
[4] Univ Siena, Dept Med Surg & Neurosci, Unit Gen Surg & Surg Oncol, Policlin Le Scotte, Viale Bracci, I-53100 Siena, Italy
[5] Univ Florence, Dept Expt & Clin Med, Largo Brambilla 3, I-50134 Florence, Italy
[6] Univ Hosp Florence, Azienda Osped Careggi, I-50134 Florence, Italy
[7] Univ Florence, I-50134 Florence, Italy