[1] Univ Maryland, Div Gastroenterol & Hepatol, Sch Med, Baltimore, MD USA
[2] Natl Inst Diabet & Digest & Kidney Dis, Digest Dis Branch, NIH, Bethesda, MD USA
[3] Michigan State Univ, Coll Human Med, Dept Med, E Lansing, MI USA
[4] Univ Maryland, Dept Med, Sch Med, Baltimore, MD USA
[5] George Washington Univ, Dept Med, Washington, DC USA
[6] Cleveland Clin, Dept Gastroenterol Hepatol & Nutr, Cleveland, OH USA
[7] Univ Maryland, Med Ctr, 22 South Greene St, Baltimore, MD 21201 USA