Browsing by Author "Urra, S"

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    A 10-Gene Classifier for Indeterminate Thyroid Nodules: Development and Multicenter Accuracy Study
    (2017) González Oneto, Humberto; Martínez, J.; Vargas Salas, Sergio; Solar González, Antonieta Alejandra; Véliz García, Loreto Pamela; Cruz, F.; Arias, T.; Loyola Zunino, Sandra; Horvath, E.; Tala, H.; Traipe, E.; Meneses, M.; Marín, L.; Wohllk, N.; Díaz, R.; Véliz, J.; Pineda, P.; Arroyo, P.; Mena, N.; Bracamonte, M.; Miranda, G.; Bruce, E.; Urra, S
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    Serological response to Helicobacter pylori recombinant antigens in Chilean infected patients with duodenal ulcer, non-ulcer dyspepsia and gastric cancer
    (1999) Opazo, P; Müller, I; Rollán, A; Valenzuela, P; Yudelevich, A; García-de la Guarda, R; Urra, S; Venegas, A
    We have previously cloned 10 Helicobacter pylori antigen genes from a Chilean strain including: cytotoxin VacA, a truncated region of CagA (called A17), a species-specific protein (Ag26), urease subunits (UreA, UreB), a flagellin, (FlaB), heat shock proteins (HspA and HspB), an adhesin (HpaA) and a lipoprotein (Lpp20). Immunogenicity of these antigens was tested by immunoblot with sera of Chilean infected patients, revealing that HpaA, A17, HspB and VacA were more frequently recognized (86%, 820/o, 68% and 68%, respectively). According to the clinical condition, it was determined that Lpp20 was preferentially recognized by sera from non-ulcer dyspepsia patients (80%), A17 and VacA by patients with duodenal ulcer (92% and 83% respectively), and HspB by patients with duodenal ulcer (83%) and gastric cancer (90%). An ELISA was developed with a purified mixture of A17 and VacA antigens to test the different groups of patients. It was found that sera from duodenal ulcer patients showed higher values than those from non-ulcer dyspepsia patients, but this difference was not significant (p<0.2). Moreover, sera from gastric cancer patients showed values lower than those from non-ulcer dyspepsia patients (p<0.019). These results indicate that, in the Chilean population, antibodies raised against VacA and A17 are not markers either for duodenal ulcer or for gastric cancer.