[1] NIDDK, Digest Dis Branch, NIH, Bethesda, MD 20892 USA
[2] Univ Maryland, Sch Med, Dept Med, Div Gastroenterol & Hepatol, Baltimore, MD 21201 USA
[3] Univ Maryland, Dept Med, Med Ctr, Baltimore, MD 21201 USA
[4] Univ Maryland, Sch Med, Dept Pathol, Baltimore, MD 21201 USA