Brazilian Journal of Medical and Biological Research, Vol 34, Iss 9, Pp 1209-1215 (2001) Brazilian Journal of Medical and Biological Research v.34 n.9 2001 Brazilian Journal of Medical and Biological Research Associação Brasileira de Divulgação Científica (ABDC) instacron:ABDC Brazilian Journal of Medical and Biological Research, Volume: 34, Issue: 9, Pages: 1209-1215, Published: SEP 2001