1. Gastroenterology Department, Digestive Unit, Champalimaud Foundation, Lisbon, Portugal
2. Endoscopy Digestive Unit, Dr. Ayres Menezes Hospital, Sao Tome and Principe
3. Gastroenterology Department, Hospital Garcia de Orta, Almada, Portugal
4. Gastroenterology Department, Centro Hospitalar e Universitário de Coimbra, Portugal
5. Instituto Marques de Valle Flôr, Portugal