[1] St Louis Univ, Sch Med, Edward Doisy Res Ctr, Dept Internal Med,Div Gastroenterol & Hepatol, 1100 S Grand Blvd,Room 205, St Louis, MO 63104 USA
[2] Univ Cincinnati, Coll Med, Dept Pathol & Lab Med, Cincinnati, OH 45237 USA
[3] Univ Bari, Sch Med, Dept Internal Med & Publ Med, Clin Medica A Murri, I-70124 Bari, Italy