[1] Univ Cincinnati, Coll Med, Cincinnati, OH 45221 USA
[2] RTI Int, Res Triangle Pk, NC USA
[3] Univ Fed Pernambuco, Hosp Clin, Recife, PE, Brazil
[4] Univ Estadual Campinas, Campinas, SP, Brazil
[5] Univ Estadual Paulista, Botucatu, SP, Brazil
[6] Univ Fed Rio Grande do Sul, Hosp Clin, Porto Alegre, RS, Brazil