Browsing by Author "Torres, Javier"

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    14-day triple, 5-day concomitant, and 10-day sequential therapies for Helicobacter pylori infection in seven Latin American sites: a randomised trial
    (ELSEVIER SCIENCE INC, 2011) Greenberg, E. Robert; Anderson, Garnet L.; Morgan, Douglas R.; Torres, Javier; Chey, William D.; Eduardo Bravo, Luis; Dominguez, Ricardo L.; Ferreccio, Catterina; Herrero, Rolando; Lazcano Ponce, Eduardo C.; Mercedes Meza Montenegro, Maria; Pena, Rodolfo; Pena, Edgar M.; Salazar Martinez, Eduardo; Correa, Pelayo; Elena Martinez, Maria; Valdivieso, Manuel; Goodman, Gary E.; Crowley, John J.; Baker, Laurence H.
    Background Evidence from Europe, Asia, and North America suggests that standard three-drug regimens of a proton-pump inhibitor plus amoxicillin and clarithromycin are significantly less effective for eradication of Helicobacter pylori infection than are 5-day concomitant and 10-day sequential four-drug regimens that include a nitroimidazole. These four-drug regimens also entail fewer antibiotic doses than do three-drug regimens and thus could be suitable for eradication programmes in low-resource settings. Few studies in Latin America have been done, where the burden of H pylori-associated diseases is high. We therefore did a randomised trial in Latin America comparing the effectiveness of four-drug regimens given concomitantly or sequentially with that of a standard 14-day regimen of triple therapy.
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    Gastric cancer incidence and mortality is associated with altitude in the mountainous regions of Pacific Latin America
    (2013) Torres, Javier; Correa, Pelayo; Ferreccio, Catterina; Hernandez-Suarez, Gustavo; Herrero, Rolando; Cavazza-Porro, Maria; Dominguez, Ricardo; Morgan, Douglas
    In Latin America, gastric cancer is a leading cancer, and countries in the region have some of the highest mortality rates worldwide, including Chile, Costa Rica, and Colombia. Geographic variation in mortality rates is observed both between neighboring countries and within nations. We discuss epidemiological observations suggesting an association between altitude and gastric cancer risk in Latin America. In the Americas, the burden of gastric cancer mortality is concentrated in the mountainous areas along the Pacific rim, following the geography of the Andes sierra, from Venezuela to Chile, and the Sierra Madre and Cordillera de Centroam,rica, from southern Mexico to Costa Rica. Altitude is probably a surrogate for host genetic, bacterial, dietary, and environmental factors that may cluster in the mountainous regions. For example, H. pylori strains from patients of the Andean Nario region of Colombia display European ancestral haplotypes, whereas strains from the Pacific coast are predominantly of African origin. The observation of higher gastric cancer rates in the mountainous areas is not universal: the association is absent in Chile, where risk is more strongly associated with the age of H. pylori acquisition and socio-economic determinants. The dramatic global and regional variations in gastric cancer incidence and mortality rates offer the opportunity for scientific discovery and focused prevention programs.
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    Identification of anti-Helicobacter pylori antibody signatures in gastric intestinal metaplasia
    (2023) Song, Lusheng; Song, Minkyo; Rabkin, Charles S.; Chung, Yunro; Williams, Stacy; Torres, Javier; Corvalan, Alejandro H.; Gonzalez, Robinson; Bellolio, Enrique; Shome, Mahasish; LaBaer, Joshua; Qiu, Ji; Camargo, M. Constanza
    Background Chronic Helicobacter pylori infection may induce gastric intestinal metaplasia (IM). We compared anti-H. pylori antibody profiles between IM cases and non-atrophic gastritis (NAG) controls. Methods We evaluated humoral responses to 1528 H. pylori proteins among a discovery set of 50 IM and 50 NAG using H. pylori protein arrays. Antibodies with >= 20% sensitivity at 90% specificity for either group were selected and further validated in an independent set of 100 IM and 100 NAG using odds ratios (OR). A validated multi-signature was evaluated using the area under the receiver operating characteristics curve (AUC) and net reclassification improvement (NRI). Results Sixty-two immunoglobulin (Ig) G and 11 IgA antibodies were detected in > 10%. Among them, 22 IgG and 6 IgA antibodies were different between IM and NAG in the discovery set. Validated antibodies included 11 IgG (anti-HP1177/Omp27/HopQ [OR = 8.1, p < 0.001], anti-HP0547/CagA [4.6, p < 0.001], anti-HP0596/Tip alpha [4.0, p = 0.002], anti-HP0103/TlpB [3.8, p = 0.001], anti-HP1125/PalA/Omp18 [3.1, p = 0.001], anti-HP0153/RecA [0.48, p = 0.03], anti-HP0385 [0.41, p = 0.006], anti-HP0243/TlpB [0.39, p = 0.016], anti-HP0371/FabE [0.37, p = 0.017], anti-HP0900/HypB/AccB [0.35, p = 0.048], and anti-HP0709 [0.30, p = 0.003]), and 2 IgA (anti-HP1125/PalA/Omp18 [2.7, p = 0.03] and anti-HP0596/Tip alpha [2.5, p = 0.027]). A model including all 11 IgG antibodies (AUC = 0.81) had better discriminated IM and NAG compared with an anti-CagA only (AUC = 0.77) model (NRI = 0.44; p = 0.001). Conclusions Our study represents the most comprehensive assessment of anti-H. pylori antibody profiles in IM. The target antigens for these novel antibodies may act together with CagA in the progression to IM. Along with other biomarkers, specific H. pylori antibodies may identify IM patients, who would benefit from surveillance.
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    Management of Helicobacter pylori infection in Latin America : A Delphi technique-based consensus
    (2014) Rollan, Antonio; Arab Verdugo, Juan Pablo; Camargo, M. Constanza; Candia Balboa, Roberto; Harris D., Paul R.; Ferreccio Readi, Catterina; Rabkin, Charles S.; Gana Ansaldo, Juan Cristóbal; Cortés, Pablo; Herrero, Rolando; Durán, Luisa; García, Apolinaria; Toledo, Claudio; Espino Espino, Alberto Antonio; Lustig, Nicole; Sarfatis Feige, Alberto; Figueroa, Catalina; Torres, Javier; Riquelme Pérez, Arnoldo
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    Reusable Low-Cost 3D Training Model for Aneurysm Clipping
    (2021) Mery, Francisco; Aranda, Francisco; Mendez-Orellana, Carolina; Caro, Ivan; Pesenti, Jose; Torres, Javier; Rojas, Ricardo; Villanueva, Pablo; Germano, Isabelle
    BACKGROUND: Aneurysm clipping requires the proficiency of several skills, yet the traditional way of practicing them has been recently challenged, especially by the growth of endovascular techniques. The use of simulators could be an alternative educational tool, but some of them are cumbersome, expensive to implement, or lacking in realism. The aim of this study is to evaluate a reusable low-cost 3-dimensional printed training model we developed for aneurysm clipping.
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    Serological response to Helicobacter pylori infection among Latin American populations with contrasting risks of gastric cancer
    (2015) Camargo, M. Constanza; Beltrán, Mauricio; Conde Glez, Carlos J.; Harris D., Paul R.; Michel, Angelika; Waterboer, Tim; Flórez, Astrid Carolina; Torres, Javier; Ferreccio Readi, Catterina; Sampson, Joshua N.; Pawlita, Michael; Rabkin, Charles S.
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    Theoretical Calculations of the Multistep Reaction Mechanism Involved in Asparagine Pyrolysis Supported by Degree of Rate Control and Thermodynamic Control Analyses
    (2019) Cervantes, Cristian; Mora, Jose R.; Marquez, Edgar; Torres, Javier; Rincon, Luis; Mendez, Miguel A.; Alcazar, Jackson J.
    A computational study on the mechanisms of reaction for the pyrolysis of asparagine is presented. A density functional theory (DFT) study at the omega B97XD/6-311G(d,p) level was performed to analyze the differences in two reaction mechanisms: (i) the formation of five-membered cyclic products: maleimide and succinimide, and (ii) the more classical, six-membered cyclic products (diketopiperazine species) which are common in the pyrolysis of many other amino acids. The effect of temperature was included in the calculations at 300 degrees C or 625 degrees C, as required. Moreover, a detailed study based on the degree of rate control and thermodynamic control of the proposed mechanism for the formation of maleimide and succinimide is also presented. Results show that, for asparagine, the five-membered ring formation is the preferred process instead of the six-membered cycle (32 kJ/mol of Gibbs free energy difference between them at the first cyclization step); therefore, the polymerization is favored. On the other hand, the rupture of the polymer represents the highest energetic barrier (Delta G(double dagger) = 281 kJ/mol) and the most influential process in the overall rate of the reaction. These results are in good agreement with the experimental evidence.
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    Unusual Mandibular Distraction Complication in Two Neonatal Pierre Robin Sequence Patients
    (2022) Morovic, Carmen Gloria; Torres, Javier; Jorquera, Claudia
    The Pierre Robin sequence (PRS) is characterized by the triad of micrognathia, glossoptosis, and airway obstruction. Conservative management in Pierre Robin sequence consists of nasogastric tube feeding and positioning of the neonate (prone or lateral position) that facilitates the anterior position of the tongue or the application of continuous positive nasal pressure. In case of failure of this treatment, emergency tracheostomy and/or mandibular distraction must be performed. Mandibular distraction is a standard technique used by craniofacial surgeons to achieve an anteroposterior horizontal lengthening of the mandibular body, correcting the posterior position of the base of the tongue and thus retropharyngeal enlargement of the airway. The authors present 2 clinical cases of hypertrophy of the sublingual salivary glands with the use of mandibular distractors in SPR patients with severe airway obstruction.
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    Validation of a synthetic simulation model of endoscopic rectus sheath plication
    (2024) Rojas, Maria Fernanda; Torres, Javier; Figueroa, Ursula; Varas, Julian; Achurra, Pablo; Navia, Alfonso; Cuadra, Alvaro; Searle, Susana
    Purpose Literature reviews outline minimally invasive approaches for abdominal diastasis in patients without skin excess. However, few surgeons are trained in endoscopic rectus sheath plication, and no simulated training programs exist for this method. This study aimed to develop and validate a synthetic simulation model for the training of skills in this approach under the Messick validity framework. Methods A cross-sectional study was carried out to assess the participants' previous level of laparoscopic/endoscopic skills by a questionnaire. Participants performed an endoscopic plication on the model and their performance was evaluated by one blinded observer using the global rating scale OSATS and a procedure specific checklist (PSC) scale. A 5-level Likert survey was applied to 5 experts and 4 plastic surgeons to assess Face and Content validity. Results Fifteen non-experts and 5 experts in abdominal wall endoscopic surgery were recruited. A median OSATS score [25 (range 24-25) vs 14 (range 5-22); p < 0.05 of maximum 25 points] and a median PSC score [11 (range 10-11) vs 8 (range 3-10); p < 0.05 of maximum 11 points] was significantly higher for experts compared with nonexperts. All experts agreed or strongly agreed that the model simulates a real scenario of endoscopic plication of the rectus sheath. Conclusion Our simulation model met all validation criteria outlined in the Messick framework, demonstrating its ability to differentiate between experts and non-experts based on their baseline endoscopic surgical skills. This model stands as a valuable tool for evaluating skills in endoscopic rectus sheath plication.