Clinical & Biomedical Research; v. 27, n. 3 (2007): Revista HCPA Clinical and Biomedical Research; v. 27, n. 3 (2007): Revista HCPA Clinical and Biomedical Research, Vol 27, Iss 3 (2008) Repositório Institucional da UFRGS Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS