[1] Univ Utah, Hlth Sci Ctr, Div Gastroenterol Hepatol & Nutr, Salt Lake City, UT 84132 USA
[2] Univ Utah, Hlth Sci Ctr, Dept Family & Prevent Med, Salt Lake City, UT 84132 USA
[3] Hennepin Cty Med Ctr, Minneapolis, MN 55415 USA
[4] Mater Hosp, Dublin, Ireland
[5] Mayo Clin, Rochester, MN USA
[6] Univ Arizona, Med Ctr, Tucson, AZ USA
[7] So Utah Gl, St George, UT USA
[8] Indiana Univ, Med Ctr, Indianapolis, IN 46204 USA
[9] Univ New Mexico, Albuquerque, NM 87131 USA
[10] Georgetown Univ, Med Ctr, Washington, DC 20007 USA
[11] Penn State Univ, Baltimore, MD USA
[12] Medctr, Bismarck, ND USA
[13] Middlefort Clin, Eau Claire, WI USA
[14] Inst So Calif, Pasadena, CA USA
[15] Vet Adm Med Ctr, Phoenix, AZ USA
[16] Marshfield Clin Fdn Med Res & Educ, Marshfield, WI USA
[17] Methodist Hosp, Dallas, TX USA
[18] Brigham & Womens Hosp, Boston, MA 02115 USA