Clinical & Biomedical Research; Vol. 24 No. 2-3 (2004): Revista HCPA Clinical and Biomedical Research; v. 24 n. 2-3 (2004): Revista HCPA Clinical and Biomedical Research Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS Clinical & Biomedical Research; v. 24, n. 2-3 (2004): Revista HCPA Clinical and Biomedical Research; v. 24, n. 2-3 (2004): Revista HCPA