[1] Univ Cagliari, Sch Paediat, I-09124 Cagliari, Italy
[2] Univ Bari, Univ Hosp Policlin, Dept Emergency & Organ Transplantat, Gastroenterol Unit, Piazza G Cesare 11, I-70124 Bari, Italy
[3] Univ Bari, Childrens Hosp Giovanni 23, Dept Biomed Sci & Human Oncol, I-70126 Bari, Italy
[4] Univ Cagliari, Azienda Ospedaliero Univ, Neonatal Intens Care Unit, I-09124 Cagliari, Italy