[1] Univ Fed Rio Grande do Sul, Dept Internal Med, BR-90035003 Porto Alegre, RS, Brazil
[2] Hosp Clin Porto Alegre, BR-90035003 Porto Alegre, RS, Brazil
[3] Hosp Dresden Neustadt, D-01129 Dresden, Germany
[4] Univ Fed Rio Grande do Sul, Dept Stat, BR-91509900 Porto Alegre, RS, Brazil
[5] Univ Fed Rio Grande do Sul, Ctr Univ Feevale, BR-93352000 Novo Hamburgo, Brazil