[1] Johns Hopkins Univ, Sch Med, Baltimore, MD USA
[2] Duke Clin Res Inst, Durham, NC USA
[3] Mt Vernon Endoscopy Ctr, Alexandria, VA USA
[4] Virginia Commonwealth Univ, Med Ctr, Richmond, VA USA
[5] Louisiana State Univ, Hlth Sci Ctr, Shreveport, LA 71105 USA
[6] Thomas Jefferson Univ, Philadelphia, PA 19107 USA
[7] Kelsey Res Fdn, Houston, TX USA
[8] Univ Alabama, Birmingham Liver Ctr, Birmingham, AL USA
[9] Penn Hosp, Philadelphia, PA 19107 USA
[10] Henry Ford Hosp, Detroit, MI 48202 USA
[11] Metro Hlth Med Ctr, Cleveland, OH USA
[12] Digest Dis Associates, Baltimore, MD USA
[13] Louisiana State Univ, Hlth Sci Ctr, Baton Rouge, LA 70803 USA
[14] Liver Inst Methodist Dallas, Dallas, TX USA
[15] Schering Plough Corp, Res Inst, Kenilworth, NJ 07033 USA