Paulo Mazzoncini de Azevedo-Marques1, José Raniery Ferreira2. 1. Ribeirão Preto Medical School, University of São Paulo, Av. dos Bandeirantes 3900, 14049-900, Ribeirão Preto, SP, Brazil. 2. Ribeirão Preto Medical School, University of São Paulo, Av. dos Bandeirantes 3900, 14049-900, Ribeirão Preto, SP, Brazil. Electronic address: jose.raniery@hc.fm.usp.br.