Browsing by Author "Lucero, Yalda"
Now showing 1 - 13 of 13
Results Per Page
Sort Options
Item Accuracy of a Genetic Test for the Diagnosis of Hypolactasia in Chilean Children: Comparison With the Breath Test.(Philadelphia, PA : Lippincott Williams & Wilkins, 2016) Alliende, Francisco; Vial, Cecilia; Espinoza, Karen; Schnettle, Daniela; Romero, Victoria; Miquel, Isabel; Arancibia, María Eugenia; Ríos, Gloria; Rodríguez, Lorena; Quesada, Soledad; Lucero, Yalda; Repetto, GabrielaBACKGROUND: Lactase nonpersistence (LNP) in humans is a genetically determined trait. This age-dependent decrease of lactase expression is most frequently caused by single nucleotide polymorphisms in the regulatory region of the lactase (LCT) gene. The homozygous LCT-13,910C/C genotype (rs 4988235) predominates in Caucasian adults with LNP, and is useful for its diagnosis in this population. The accuracy of this genetic test (GT) has not been completely established in children or in a Latin-American population. OBJECTIVES: The aim of the study was to determine diagnostic accuracy of GT for LNP in Chilean children using the lactose breath test (BT) as a reference, and to compare diagnostic yield in preschool- (<6 years) and in school-age (≥6 years) children. METHODS: Children referred for BT for diagnosis of lactose malabsorption to the Gastroenterology Laboratory at Clínica Alemana, Santiago, from October 2011 to March 2012 were invited to participate. After informed consent, symptom questionnaires, both historic and post lactose ingestion were completed. H2 and CH4 in expired air and -13,910 C>T single nucleotide polymorphism by polymerase chain reaction, restriction enzyme analysis, and/or Sanger sequencing were determined. GT accuracy was calculated compared to BT as reference method. Diagnostic yield of GT in preschool- and school-age children was compared. RESULTS: Lactose malabsorption was detected by BT in 42 of 60 children (70%). Genotype -13,910C/C was identified in 41 of 60 patients (68%). GT showed 80% sensitivity, 63% specificity, and 74% accuracy for LNP in the preschool population. In school-age children values were higher, 85%, 80%, and 84%, respectively. CONCLUSIONS: GT results were significantly concordant with BT results for hypolactasia detection in Chilean children, particularly in those of age 6 years and older.Item Adaptación a la realidad de Latinoamérica de la Guía Clínica NASPGHAN/ESPGHAN 2016 sobre Diagnóstico, Prevención y Tratamiento de Infección por Helicobacter pylori en Pediatría(2020) Harris, Paul R.; Calderón-Guerrero, Otto Gerardo; Vera-Chamorro, José Fernando; Lucero, Yalda; Vásquez, Margarita; Ogata, Silvio Kazuo; Angulo, Diana; Madrazo, Armando; Gonzáles, José; Rivero, Anelsy; Gana, Juan Cristóbal; Sociedad Latinoamericana de Gastroenterología, Hepatología y Nutrición Pediátrica (SLAGHNP/LASPGHAN)Introducción: Las últimas guías clínicas conjuntas de NASPGHAN y ESPGHAN en relación a la infección por H. pylori publicadas el año 2016, contienen 20 afirmaciones que han sido cuestionadas en la práctica respecto a su aplicabilidad en Latinoamérica (LA); en particular en relación a la prevención del cáncer gástrico. Métodos: Se realizó un análisis crítico de la literatura, con especial énfasis en datos de LA y se estableció el nivel de evidencia y nivel de recomendación de las afirmaciones mas controversiales de las Guías Conjuntas. Se realizaron 2 rondas de votación de acuerdo a la técnica Delfi de consenso y se utilizó escala de Likert (de 0 a 4) para establecer el “grado de acuerdo” entre un grupo de expertos de SLAGHNP. Resultados: Existen pocos estudios en relación a diagnóstico, efectividad de tratamiento y susceptibilidad a antibióticos de H. pylori en pacientes pediátricos de LA. En base a estos estudios, extrapolaciones de estudios de adultos y la experiencia clínica del panel de expertos participantes, se realizan las siguientes recomendaciones. Recomendamos la toma de biopsias para test rápido de ureasa e histología (y muestras para cultivo o técnicas moleculares, cuando estén disponibles) durante la endoscopia digestiva alta sólo si en caso de confirmar la infección por H. pylori, se indicará tratamiento de erradicación. Recomendamos que centros regionales seleccionados realicen estudios de sensibilidad/resistencia antimicrobiana para H. pylori y así actúen como centros de referencia para toda LA. En caso de falla de erradicación de H. pylori con tratamiento de primera línea, recomendamos tratamiento empírico con terapia cuádruple con inhibidor de bomba de protones, amoxicilina, metronidazol y bismuto por 14 días. En caso de falla de erradicación con el esquema de segunda línea, se recomienda indicar un tratamiento individualizado considerando la edad del paciente, el esquema indicado previamente y la sensibilidad antibiótica de la cepa, lo que implica realizar una nueva endoscopía con extracción de muestra para cultivo y antibiograma o estudio molecular de resistencia. En niños sintomáticos referidos a endoscopía que tengan antecedente de familiar de primer o segundo grado con cáncer gástrico, se recomienda considerar la búsqueda de H. pylori mediante técnica directa durante la endoscopia (y erradicarlo cuando es detectado). Conclusiones: La evidencia apoya mayoritariamente los conceptos generales de las Guías NASPGHAN/ESPGHAN 2016, pero es necesario adaptarlas a la realidad de LA, con énfasis en el desarrollo de centros regionales para el estudio de sensibilidad a antibióticos y mejorar la correcta selección del tratamiento de erradicación. En niños sintomáticos con antecedente familiar de primer o segundo grado de cáncer gástrico, se debe considerar la búsqueda y erradicación de H. pylori.Item Corrigendum: Helicobacter pylori cagA+ Is Associated with Milder Duodenal Histological Changes in Chilean Celiac Patients(2017) Lucero, Yalda; Oyarzún, Amaya; O’Ryan, Miguel; Quera, Rodrigo; Espinosa, Nelly; Valenzuela, Romina; Simian, Daniela; Alcalde, Elisa; Arce, Claudio; Farfán, Mauricio J; Vergara, Alejandra F; Gajardo, Iván; Mendez, Jocelyn; Carrasco, Jorge; Errázuriz, Germán; González, Mónica; Ossa, Juan C; Maiza, Eduardo; Perez-Bravo, Francisco; Castro, Magdalena; Araya, MagdalenaIn the published article, there was an error in affiliation (2). Instead of “Microbiology and Micology Program, Faculty of Medicine, University of Chile, Santiago, Chile,” it should be “Microbiology and Micology Program, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile.” The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. Additionally, there was an error regarding the affiliations for Yalda Lucero. Affiliation 8 has been removed and the following affiliation has been added instead: Pediatric Gastroenterology Unit, Department of Pediatrics, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile.Item Effect of Helicobacter pylori eradication therapy on clinical and laboratory biomarkers associated with gastric damage in healthy school-aged children: A randomized non-blinded trial(2021) Lucero, Yalda; Lagomarcino, Anne J.; Torres, Juan P.; Roessler, Patricia; Mamani, Nora; George, Sergio A.; Huerta, Nicole; González, Mónica; O'Ryan G., MiguelObjectives: Helicobacter pylori (H. pylori) is the primary cause of gastric cancer and eradication in healthy adults has proven effective in decreasing cancer incidence. H. pylori is acquired largely in early childhood, however, the benefits of eradication in children are controversial. We aimed to determine the effect of H. pylori eradication on clinical and laboratory markers associated with gastric damage in apparently healthy school-aged children. Methods: This was a pilot non-blinded trial including 61 children persistently infected with H. pylori who were randomized to eradication/no treatment and followed for at least 12 months, evaluating clinical and blood markers (Pepsinogen I (PGI) and II (PGII) determined by ELISA) associated with gastric damage. The treatment consisted of a sequential scheme including 7 days of omeprazole + amoxicillin followed by 7 days of omeprazole + clarithromycin + metronidazole; adherence and tolerance were surveyed. Eradication rates were assessed by stool antigen detection or urea breath test 1 month following treatment every 4 months thereafter to detect reinfection. Results: Eradication occurred in 30/31 treated children (median age: 8.8, range: 7.9-10.8) and in 0/30 non-treated controls (median age: 8.6, range: 7.9-11) (p < .001). Treatment was associated with mild transient symptoms (altered taste, nocturnal upper abdominal pain, nausea, and diarrhea). Baseline frequency of symptoms was low and eradication did not change symptoms compared to controls. PGI, PGII, and anti-H. pylori seropositivity were similar in both groups at baseline and significantly decreased only in eradicated patients; PGI (92.5 vs. 74.4, p < .001), PGII (15.2 vs. 8.9, p < .001) levels, and frequency of anti-H. pylori seropositivity (100 vs. 68%, p < .001) respectively. Four eradicated children (13%) were reinfected during follow-up. Conclusions: H. pylori eradication therapy in apparently asymptomatic school-aged children was well tolerated and associated with decreased serum PGI and PGII levels. Future studies should expand on the middle-long-term effect of early H. pylori eradication, especially on preventing gastric cancer.Item Enfermedad celíaca, sensibilidad no celíaca al gluten y alergia al trigo: comparación de patologías diferentes gatilladas por un mismo alimento(Sociedad Chilena de Pediatría, 2017) Ortiz, Catalina; Valenzuela, Romina; Lucero, YaldaGluten and other related proteins of the wheat, rye and barley, have antigenic properties that may trigger adverse reactions in susceptible individuals. Celiac disease was the first pathology with clear causal association related to the intake of these proteins. Recently, wheat allergy and non celiac gluten sensitivity have been described. Although, clinical presentation and its relation with protein ingestion may be similar and elicit confusion, their pathogenic mechanism, diagnosis and treatment are quite different. Since the prevalence of these diseases is relatively high as a whole, it is essential that these become familiar to primary care doctors and general pediatricians, thus they will know how to differentiate and face them. The aim of this review is to compare the main aspects of epidemiology, pathofisiology, diagnosis and treatment of these 3 conditions.Item Helicobacter pylori, clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage in healthy school-aged children: A case-control study(2020) Lucero, Yalda; Lagomarcino, Anne J.; Torres, Juan P; Roessler, Patricia; Mamani, Nora; George, Sergio; Huerta, Nicole; Gonzalez, Mónica; O'Ryan, MiguelBackground: Helicobacter pylori is acquired largely in early childhood, but its association with symptoms and indirect biomarkers of gastric damage in apparently healthy children remains controversial. We aimed to relate persistent H. pylori infection in apparently healthy school-aged children with clinical, laboratory, and noninvasive biomarkers suggestive of gastric damage using a case-control design. Materials and methods: We followed up 83 children aged 4-5 years with persistent H. pylori infection determined by stool antigen detection and/or a urea breath test and 80 noninfected matched controls from a low-income to middle-income, periurban city in Chile for at least 3 years. Monitoring included clinical visits every 4 months and annual assessment by a pediatric gastroenterologist. A blood sample was obtained to determine laboratory parameters potentially associated with gastric damage (hemogram and serum iron and ferritin levels), biomarkers of inflammation (cytokines, pepsinogens I and II, and tissue inhibitor metalloproteinase 1), and expression of cancer-related genes KLK1, BTG3, and SLC5A8. Results: Persistently infected children had higher frequency of epigastric pain on physical examination (40% versus 16%; P = 0.001), especially from 8 to 10 years of age. No differences in anthropometric measurements or iron-deficiency parameters were found. Persistent infection was associated with higher levels of pepsinogen II (median 12.7 ng/mL versus 9.0 ng/mL; P < 0.001); no difference was observed in other biomarkers or gene expression profiles. Conclusions: H. pylori infection in apparently asymptomatic school-aged children is associated with an increase in clinical symptoms and in the level of one significant biomarker, pepsinogen II, suggesting early gastric involvement.Item Limpieza intestinal para colonoscopia en niños: efectividad, adherencia y efectos adversos de esquemas diferenciados por edad(Sociedad Chilena de Pediatria, 2017) Miquel, Isabel; Arancibia, María Eugenia; Alliende, Francisco; Ríos, Gloria; Rodríguez, Lorena; Lucero, Yalda; Saelzer, EricIntroduction: Adequate intestinal cleanliness is crucial to achieve optimal colonoscopy performance. Several bowel preparation (BP) schemes have been proposed, but there is still no consensus as regards which is the most suitable in paediatric patients. Objective: To describe the effectiveness, adherence, and adverse effects of BP protocols differentiated by age group in paediatric patients subjected to colonoscopy. Patients and Method: Prospective study that included patients < 18 years subjected to colonoscopy. BP protocols differentiated by age group were indicated as follows: < 6 m (glycerine suppository); 6 m-3y 11 m (poly-ethylene-glycol (PEG 3350 without electrolytes); 4y-9y 11 m (PEG 3350 without electrolytes + bisacodyl); 10 y-18 y (PEG 3350 with electrolytes). Demographic, clinical information, adherence and adverse effects were registered. Effectiveness was determined using a validated scale (Boston modified) during colonoscopy. Results: A total of 159 patients were included, of which 87 (55%) were males, and with a median age of 4 years (range 1 m-17 years). Seventy eight percent of patients achieved successful BP. The higher effectiveness was observed in the groups of < 6 m (96%) and 10-18 y (91%). Constipation was significantly more frequent (29%) in the 4 yo-9 yo 11 m in which lower effectiveness was observed (69%). Good adherence was observed in 87% of patients. Adverse effects were observed in a third of patients, although they were mild and did not lead to the suspension of the BP. Conclusions: Satisfactory results were achieved with the BP schemes used, with a successful BP being obtained in 4 out of 5 patients. Results were different between groups, which is probably related to previous bowel transit and indicated medicationItem Norovirus compared to other relevant etiologies of acute gastroenteritis among families from a semirural county in Chile(2020) Lucero, Yalda; Lagomarcino, Anne J.; Espinoza, Mónica; Kawakami, Nanami; Mamani, Nora; Huerta, Nicole; Canto, Felipe del; Farfán, Mauricio; Sawaguchi, Yoshihiro; George, Sergio; O’Ryan, MiguelObjective: To determine the dynamics of norovirus disease, a major cause of acute gastroenteritis (AGE), compared to other relevant etiologies, among families living in a lower middle income area. Study design :Families with three or more members and with one or more healthy children <24 months of age were followed for 1–2 years to detect any AGE. Stool samples were tested for viral and bacterial pathogens and a questionnaire was completed for those with norovirus or rotavirus AGE. Results: Between April and June 2016, 110 families were enrolled, with 103 of them completing ≥12 months of follow-up. A total of 159 family AGE episodes were detected, mostly affecting one individual (92%). At least one pathogen was detected in 56% (94/169) of samples, of which 75/94 (80%) were sole infections. Norovirus was most common (n = 26), followed closely by enteropathogenic Escherichia coli (EPEC) (n = 25), rotavirus (n = 24), and astrovirus (n = 23). The annual incidence of family AGE was 0.77, and 0.12 for norovirus. Most norovirus AGE occurred in children <4 years old (96%). Only 13/159 (8%) index AGE cases resulted in a secondary case, of which four were associated with norovirus. The majority of norovirus strains were GII (85%), with a mild predominance of GII.4 (9/26; 35%); most norovirus isolates (69%) were recombinants. Conclusions: The family incidence of AGE in this lower middle income community was nearly one episode per year, mostly caused by viruses, specifically norovirus closely followed by rotavirus and astrovirus. Norovirus infections primarily affected children <4 years old and secondary cases were uncommon.Item Norovirus vaccines under development(Elsevier, 2017) Lucero, Yalda; Vidal, Roberto; O'Ryan, MiguelNoroviruses (NoVs) are one of the leading causes of acute gastroenteritis, including both outbreaks and endemic infections. The development of preventive strategies, including vaccines, for the most susceptible groups (children <5years of age, the elderly and individuals suffering crowding, such as military personnel and travelers) is desirable. However, NoV vaccine development has faced many difficulties, including genetic/antigenic diversity, limited knowledge on NoV immunology and viral cycle, lack of a permissive cell line for cultivation and lack of a widely available and successful animal model. Vaccine candidates rely on inoculation of virus-like particles (VLPs) formed by the main capsid protein VP1, subviral particles made from the protruding domain of VP1 (P-particles) or viral vectors with a NoV capsid gene insert produced by bioengineering technologies. Polivalent vaccines including multiple NoV genotypes and/or other viruses acquired by the enteric route have been developed. A VLP vaccine candidate has reached phase II clinical trials and several others are in pre-clinical stages of development. In this article we discuss the main challenges facing the development of a NoV vaccine and the current status of prevailing candidates.Item Norovirus: Facts and Reflections from Past, Present, and Future(2021) Lucero, Yalda; Matson, David O.; Ashkenazi, Shai; George, Sergio; O'Ryan, MiguelHuman Norovirus is currently the main viral cause of acute gastroenteritis (AGEs) in most countries worldwide. Nearly 50 years after the discovery of the "Norwalk virus" by Kapikian and colleagues, the scientific and medical community continue to generate new knowledge on the full biological and disease spectrum of Norovirus infection. Nevertheless, several areas remain incompletely understood due to the serious constraints to effectively replicate and propagate the virus. Here, we present a narrated historic perspective and summarize our current knowledge, including insights and reflections on current points of interest for a broad medical community, including clinical and molecular epidemiology, viral-host-microbiota interactions, antivirals, and vaccine prototypes. We also include a reflection on the present and future impacts of the COVID-19 pandemic on Norovirus infection and disease.Item Recomendaciones de Rama de Gastroenterología para situaciones relacionadas con infección COVID-19 en niños(2020) Alliende, Francisco; Cofré, Colomba; Godoy, Marcela; Lucero, Yalda; Rama de Gastroenterología Infantil de la Sociedad Chilena de PediatríaActualmente estamos viviendo una pandemia causada por un nuevo agente infeccioso, coronavirus SARS-CoV-2, también conocido como COVID-19. Agente de alta contagiosidad y moderada letalidad, se ha diseminado rápidamente alrededor del mundo. Los pacientes con patología crónica y el personal de salud son grupos particularmente vulnerables frente a este agente. De ahí la relevancia de desarrollar estrategias preventivas y difundirlas ampliamente. El presente documento generado a solicitud del Directorio de la Rama de Gastroenterología infantil de la SOCHIPE tiene como objetivo entregar herramientas a los profesionales de la salud que trabajan con niños para tomar la mejor decisión al momento de enfrentar a un paciente que requiera un procedimiento endoscópico o maneje a un paciente con sospecha o diagnóstico de enfermedad inflamatoria intestinal poder realizar en forma correcta la prevención de COVID-19Publication Successful eradication rate of Helicobacter pylori with empirical antibiotic treatment in pediatric patients from a Tertiary Hospital(2023) Darritchon Lama, Sofía; Díaz García, Diego; Toledo Complido, Marcela; Lucero, YaldaHelicobacter pylori infection is a common condition that, in the long term, is associated with the development of peptic ulcer disease and eventually gastric cancer, which could be prevented with timely treatment. Optimally, eradication success should be greater than 90%, but the recommended empirical reatments do not achieve these rates in real-life conditions. Objective: To determine the success rate of first-line empirical eradication treatment against H. pylori in pediatric patients treated in a tertiary hospital. Patients and Method: Retrospective descriptive study in patients with H. pylori infection detected in gastric biopsies and who had received first-line antibiotic treatment during the period 2017-2021. A negative result of an antigen test in stools or new iopsies after ≥ 1 month afterItem Truths, Myths and Needs of Special Diets: Attention-Deficit/Hyperactivity Disorder, Autism, Non-Celiac Gluten Sensitivity, and Vegetarianism(Karger, 2016) Cruchet, Sylvia; Lucero, Yalda; Cornejo, VeronicaDifferent dietary approaches have been attempted for the treatment of attention-deficit/hyperactivity disorder and autism, but only three of them have been subjected to clinical trials: education in healthy nutritional habits, supplementation and elimination diets. On the other hand, for multiple reasons, the number of people who adopt vegetarian and gluten-free diets (GFD) increases daily. More recently, a new entity, non-celiac gluten sensitivity (NCGS), with a still evolving definition and clinical spectrum, has been described. Although, the benefits of GFD are clearly supported in this condition as well as in celiac disease, in the last two decades, GFD has expanded to a wider population. In this review, we will attempt to clarify, according to the existing evidence, which are the myths and facts of these diets.