[1] Univ Alabama Birmingham, Birmingham, AL USA
[2] Univ Francisco Marroquin, Sch Med, Guatemala City, Sacatepequez, Guatemala
[3] Indiana Univ Sch Med, Indianapolis, IN USA
[4] NCI, Rockville, MD USA
[5] INCAP, Res Ctr Prevent Chron Dis, Guatemala City, Escuintla, Guatemala
[6] Western Reg Hosp, Santa Rosa De Copan, Copan, Honduras
[7] Presbyterian Healthcare Serv, Albuquerque, NM USA