[1] Howard Univ Hosp, Internal Med, Washington, DC USA
[2] Howard Univ, Coll Med, Internal Med, Washington, DC USA
[3] Howard Univ Hosp, Gastroenterol, Washington, DC USA
[4] Howard Univ Hosp, Internal Med, Washingon, DC 20060 USA
[5] Univ Maryland, Internal Med, Baltimore, MD 21201 USA