[1] Romark Inst Med Res, Tampa, FL USA
[2] Stanford Univ, Sch Med, Dept Med, Div Gastroenterol & Hepatol, Palo Alto, CA 94304 USA
[3] Tanta Univ, Fac Med, Dept Gastroenterol & Hepatol, Tanta, Egypt
[4] Univ Alexandria, Fac Med, Dept Trop Med & Infect Dis, Alexandria, Egypt