Affiliation: | (1) Bambino Gesù Children's Hospital, Rome, Italy, IT;(2) Department of Epidemiology and Public Health, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK e-mail: M.Newell@ich.ucl.ac.uk Tel.: +44-171-829-8699; Fax: +44-171-242-2723, GB;(3) Department of Paediatrics, University of Padua, Padua, Italy, IT;(4) Department of Paediatrics, University of Turin, Turin, Italy, IT |