1 Post Graduate Program-Science in Gastroenterology and Hepatology, School of Medicine, Porto Alegre, RS, Brazil. Electronic address: cristianobrauner@hotmail.com.
2 Gastroenterology and Hepatology Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.