Mansour-Ghanaei, Fariborz, GI Cancer Screening and Prevention Research Center, Guilan University of Medical Sciences, Rasht, Iran; Gastrointestinal and Liver Diseases Research Center, Guilan University of Medical Sciences, Razi Hospital, Sardar-Jangle Ave., P.O. Box: 41448-95655, Rasht, Iran. Tel: +98(13)33535116, Fax: +98(13)33534951, E-mail: fmansourghanaei@gmail.com; Caspian Digestive Disease Research Center, Guilan University of Medical Sciences, Rasht, Iran, Iran, Islamic Republic of