[1] Johns Hopkins Univ, Dept Med, Sinai Hosp, Program Internal Med, Baltimore, MD USA
[2] Sinai Hosp, Dept Med, Div Gastroenterol, Baltimore, MD 21215 USA
[3] Mercy Med Ctr, Dept Med, Inst Digest Hlth & Liver Dis, Baltimore, MD USA
[4] Univ Maryland, Sch Med, Dept Med, Baltimore, MD 21201 USA