[1] Univ Kentucky, Coll Med, Dept Internal Med, Div Digest Dis & Nutr, Lexington, KY 40536 USA
[2] Univ Kentucky, Coll Med, Dept Internal Med, Div Pulm Crit Care, Lexington, KY 40536 USA
[3] Univ Kentucky, Coll Med, Dept Physiol, Lexington, KY 40536 USA
[4] Louisiana State Univ, Hlth Sci Ctr, Dept Anat & Cell Biol, New Orleans, LA 70112 USA
[5] Univ Louisville, Dept Internal Med, Div Gastroenterol Hepatol, Louisville, KY 40292 USA
[6] Vet Adm Med Ctr, Louisville, KY 40292 USA