[1] Ctr Hosp Univ Lisboa Norte, Hosp St Maria, Fac Med Lisboa, Serv Gastrenterol & Hepatol,Clin Univ Gastrentero, Av Prof Egas Moniz, P-1649035 Lisbon, Portugal
[2] Hosp Braga, Serv Gastrenterol, Braga, Portugal
[3] Inst Portugues Oncol Francisco Gentil, Serv Gastrenterol, Lisbon, Portugal
[4] Ctr Hosp Univ Lisboa Cent, Hosp St Antonio Capuchos, Serv Gastrenterol, Lisbon, Portugal
[5] Univ Algarve, Ctr Hosp Univ Algarve, Biomed Ctr Algarve, Serv Gastrenterol, Portimao, Portugal
[6] Ctr Hosp Tondela Viseu, Serv Gastrenterol, Viseu, Portugal
[7] Ctr Hosp Univ Coimbra, Serv Gastrenterol, Coimbra, Portugal
[8] Hosp Sao Bernardo, Serv Gastrenterol, Setubal, Portugal
[9] Hosp Sao Joao, Serv Gastrenterol, Porto, Portugal
[10] Univ Porto, Inst Mol & Cell Biol, Dept Pharmacol & Therapeut, Porto, Portugal