Browsing by Author "Raddatz Echavarría, Alejandro"

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    Biliary aminopeptidase-N and the cholesterol crystallization defect in cholelithiasis
    (British Medical Journal Publishing Group, 1995) Núñez, L.; Amigo Boker, Ludwig Peter; Mingrone, G.; Rigotti Rivera, Attilio Gianpietro; Puglielli, L.; Raddatz Echavarría, Alejandro; Pimentel González, Eduardo Fernando; Greco, A.; González, S.; Garrido Negri, Jorge; Miquel Poblete, Juan Francisco; Nervi Oddone, Flavio; Pontificia Universidad Católica de Chile. Departamento de Gastroenterología y Centro para la Prevención y tratamiento del Cáncer Digestivo; Institute of Clinical Medicine, Universita Cattolica del Sacro Cuore, Rome, Italy
    Several biliary proteins have cholesterol crystallisation promoting activity. One of these glycoproteins is aminopeptidase-N, a canalicular ectoenzyme. This study attempted to localise aminopeptidase-N along the biliary tree, to assess its concentration in a series of 98 patients subjected to abdominal surgery, 40 of them without gap stones, and to correlate its concentration with cholesterol crystal formation time of gall bladder bile. Aminopeptidase-N was isolated from purified native biliary vesicles. A specific polyclonal rabbit anti-aminopeptidase-N antibody was prepared for quantitative immunoblotting and for immunolocalisation. Tissue was obtained from liver biopsy specimens and from gall bladders removed at surgery because of gall stone disease. Aminopeptidase-N was immunolocalised to the apical membranes of hepatocytes and to the apical pole of ductular and gall bladder mucosal cells. The nucleation time of gall bladder bile was mean (SD) 4 (3) days in the gall stone group, compared with 21 (18) days in the control group (p < 0.001). Total absolute biliary protein and aminopeptidase-N concentrations were similar in both the control and gall stone patients. There was a reciprocal significant correlation, however, between the nucleation time and the relative aminopeptidase-N concentration (r = -0.35, p < 0.01) only in the gall stone group of patients, This study shows that this apical transmembrane ectoenzyme with cholesterol crystallisation promoting activity is present along the biliary tree and the hepatocyte. These findings support the concept that high concentrations or qualitative changes of biliary aminopeptidase-N contribute to cholesterol gall stone formation.
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    Cholesterol saturation, not proteins or cholecystitis, is critical for crystal formation in human gallbladder bile
    (W. B. Saunders Co., 1998) Miquel Poblete Juan Francisco; Nuñez, Liliana; Amigo Boker, Ludwig Peter; González Bombardiere, Sergio Javier; Raddatz Echavarría, Alejandro; Rigotti Rivera, Attilio Gianpietro; Nervi Oddone, Flavio
    Biliary proteins are promoters of cholesterol crystallization in artificial model bile. However, their pathogenic importance for cholesterol precipitation in native gallbladder bile (GB) is uncertain. The aim of this study was to evaluate the significance of biliary lipids and proteins on cholesterol crystal detection time (ChCDT) of GB in patients with gallstones. Methods: ChCDT and concentrations of lipids, albumin, mucins, aminopeptidase N, alpha 1-acid glycoprotein, haptoglobin, and immunoglobulins (Igs) were measured in GB of 92 patients, 52 of whom had cholesterol gallstones. Results: ChCDT was markedly reduced in gallstone patients. Compared with patients without gallstones, they had a significant increase in cholesterol saturation and total protein, albumin, mucin, and IgG biliary concentrations. In univariate analysis, ChCDT of GB was significantly correlated with cholesterol saturation and total lipid, protein, Ig, aminopeptidase N, and alpha 1-acid glycoprotein concentrations. However, stepwise logistic regression analysis showed that only cholesterol saturation independently correlated to ChCDT. Gallbladder inflammation correlated with the concentration of Igs, but subtraction of IgG from GB did not modify the ChCDT. Conclusions: Biliary cholesterol transport and saturation, but not proteins, appear critical for the cholesterol crystallization abnormality observed in native bile from patients with gallstones.
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    High Frequency of Internal Hernias After Roux-en-Y Gastric Bypass
    (2015) Quezada Sanhueza, Nicolás; León, Felipe; Jones, Alex; Varas, Julián; Funke, Ricardo; Crovari Eulufi, Fernando; Raddatz Echavarría, Alejandro; Pérez Blanco, Gustavo Adolfo; Escalona, Alex; Boza, Camilo; Quezada Sanhueza, Nicolás; León, Felipe; Jones, Alex; Varas, Julián; Funke, Ricardo; Crovari Eulufi, Fernando; Raddatz, Alejandro; Pérez Blanco, Gustavo Adolfo; Escalona, Alex; Boza, Camilo
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    Intususcepción intestinal posterior a bypass gástrico en Y de Roux
    (2010) Norero Muñoz, Enrique; Raddatz Echavarría, Alejandro; Guzmán Karadima, Sergio
    Intussusception is a rare complication following Roux-en-Y gastric bypass surgery, and can be present with various complaints making it difficult to diagnose and even more challenging in the pregnant patients. We describe a case of a 32-year-old woman at
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    Laparoscopic sleeve gastrectomy conversion to Roux-en-Y gastric bypass : experience in 50 patients after 1 to 3 years of follow-up
    (2016) Quezada Sanhueza, Nicolás; Hernandez, J.; Pérez Blanco, Gustavo Adolfo; Gabrielli Nervi, Mauricio; Raddatz Echavarría, Alejandro; Crovari Eulufi, Fernando; Quezada Sanhueza, Nicolás; Hernandez, J.; Pérez Blanco, Gustavo Adolfo; Gabrielli Nervi, Mauricio; Raddatz, A.; Crovari Eulufi, Fernando
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