[1] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Immunol & Rheumatol, Mexico City, DF, Mexico
[2] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Expt Surg, Vasco Quiroga 15,Secc 16, Mexico City 14080, DF, Mexico
[3] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Gastroenterol, Mexico City, DF, Mexico
[4] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Dept Surg, Mexico City, DF, Mexico