1. Division of Gastroenterology Ospedale di Acireale Azienda Sanitaria Provinciale di Catania Catania Italy
2. Section of Gastroenterology and Hepatology PROMISE University of Palermo Palermo Italy
3. Department of Nursing Management and Epidemiology Nursing Jagiellonian University Medical College Krakow Poland
4. Department of Biomedical and Biotechnological Sciences University of Catania Catania Italy
5. Department of Molecular and Developmental Medicine University of Siena Siena Italy