Browsing by Author "Serrano, Carolina"

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    Diagnóstico de la infección por Helicobacter pylori en niños mediante la detección de antígenos en deposiciones
    (2007) González, Carmen Gloria; Serrano, Carolina; Harris, Paul R.
    Background: During infancy, preventive, diagnostic and therapeutic efforts for Helicobacter pylori infection should be made. Aim: To evaluate non-invasive diagnostic methods such as stool antigen test (HpSA) and serum anti-H pylori antibody detection (IgG e IgA), compared to endoscopy-based invasive methods (histology and urease test) for the diagnosis of Helicobacter pylori infection. Patients and Methods: Thirty nine children (aged 3 to 14 years, 20 males) referred for upper gastrointestinal endoscopy, were studied. The gold standard to diagnose Helicobacter pylori infection was defined as a positive invasive diagnostic test (histology and/or urease test). Sensitivity (S), specificity (E) and positive (PPV) and negative (NPV) predictive values were obtained for HpSA and serum antibodies. Results: Ten children (26%) were infected with H pylori. S, E, PPV and NPV for HpSA were 90, 100, 100 and 97%, respectively. The figures for serum IgG were 81, 97, 89 and 93%, respectively and for IgA, 90, 76, 36 and 96%, respectively. Conclusions: HpSA was sensitive and specific as a clinical and epidemiological tool to evaluate H pylori infection in children. Serology was not as accurate, but IgG had a better performance than IgA. © 2007 Sociedad Médica de Santiago.
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    Differences in lung glutathione metabolism may account for rodent susceptibility in elastase-induced emphysema development
    (AMER PHYSIOLOGICAL SOC, 2009) Borzone, Gisella R.; Liberona, Leonel F.; Bustamante, Andrea P.; Saez, Claudia G.; Olmos, Pablo R.; Vecchiola, Andrea; Villagran, Andrea; Serrano, Carolina; Reyes, Tatiana P.
    Borzone GR, Liberona LF, Bustamante AP, Saez CG, Olmos PR, Vecchiola A, Villagran A, Serrano C, Reyes TP. Differences in lung glutathione metabolism may account for rodent susceptibility in elastase-induced emphysema development. Am J Physiol Regul Integr Comp Physiol 296: R1113-R1123, 2009. First published January 14, 2009; doi: 10.1152/ajpregu.90361.2008.-Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats after intratracheal instillation of the same dose of elastase/body weight. Although species variations in antielastase defenses may largely explain these results, other variables, such as differences in lung antioxidants, cannot be overlooked since oxidative stress modulates antiprotease activity. We propose that elastase instillation might affect lung glutathione (GSH) metabolism differently in these species. Our aim was to study in hamsters and rats, lung glutathione metabolism at different times, from the stage of diffuse alveolar damage to advanced emphysema. We measured total and oxidized glutathione content as well as activity and expression of enzymes related to GSH synthesis and redox cycling: gamma-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase. Whereas rats showed no significant changes in these measurements, hamsters showed significant derangement in GSH metabolism early after elastase instillation: 25% fall in total GSH (P < 0.05) with no increase in oxidized glutathione associated with reduced enzyme activities 24 h after elastase [60% for gamma-glutamylcysteine synthetase (P < 0.01), 30% for glutathione peroxidase (P < 0.01), and 75% for glutathione reductase (P < 0.001)]. GSH homeostasis was restored at the end of the first week, involving transient increased expression of these enzymes. We conclude that elastase induces significant alterations in GSH metabolism of hamster lungs and no overall change in rat lungs. Although differences in disease severity may account for our findings, the hamster becomes vulnerable to functional inhibition of alpha(1)-antitrypsin by oxidants and thus, even more susceptible to injury than it would be, considering only its low alpha(1)-antitrypsin level.
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    Gastric cancer is related to early Helicobacter pylori infection in a high-prevalence country
    (AMER ASSOC CANCER RESEARCH, 2007) Ferreccio, Catterina; Rollan, Antonio; Harris, Paul R.; Serrano, Carolina; Gederlini, Alessandra; Margozzini, Paula; Gonzalez, Claudia; Aguilera, Ximena; Venegas, Alejandro; Jara, Alejandro
    Background and Aims: Chile ranks fifth in the world among countries with the highest incidence of gastric cancer. The aim was to quantify the association between Helicobacter pylori infection and gastric cancer mortality at the county of residence.
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    Iron Status and Helicobacter pylori Infection in Symptomatic Children: An International Multi-Centered Study
    (2013) Magalhaes Queiroz, Dulciene Maria; Harris, Paul; Sanderson, Ian R.; Windle, Henry J.; Walker, Marjorie M.; Camargos Rocha, Andreia Maria; Rocha, Gifone Aguiar; Carvalho, Simone Diniz; Souto Bittencourt, Paulo Fernando; Fonseca de Castro, Lucia Porto; Villagran, Andrea; Serrano, Carolina; Kelleher, Dermot; Crabtree, Jean E.
    Objective: Iron deficiency (ID) and iron deficiency anaemia (IDA) are global major public health problems, particularly in developing countries. Whilst an association between H. pylori infection and ID/IDA has been proposed in the literature, currently there is no consensus. We studied the effects of H. pylori infection on ID/IDA in a cohort of children undergoing upper gastrointestinal endoscopy for upper abdominal pain in two developing and one developed country. Methods: In total 311 children (mean age 10.7±3.2 years) from Latin America - Belo Horizonte/Brazil (n = 125), Santiago/Chile (n = 105) - and London/UK (n = 81), were studied. Gastric and duodenal biopsies were obtained for evaluation of histology and H. pylori status and blood samples for parameters of ID/IDA. Results: The prevalence of H. pylori infection was 27.7% being significantly higher (p<0.001) in Latin America (35%) than in UK (7%). Multiple linear regression models revealed H. pylori infection as a significant predictor of low ferritin and haemoglobin concentrations in children from Latin-America. A negative correlation was observed between MCV (r = −0.26; p = 0.01) and MCH (r = −0.27; p = 0.01) values and the degree of antral chronic inflammation, and between MCH and the degree of corpus chronic (r = −0.29, p = 0.008) and active (r = −0.27, p = 0.002) inflammation. Conclusions: This study demonstrates that H. pylori infection in children influences the serum ferritin and haemoglobin concentrations, markers of early depletion of iron stores and anaemia respectively.
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    Non-invasive diagnosis of gastric mucosal atrophy in an asymptomatic population with high prevalence of gastric cancer
    (BAISHIDENG PUBLISHING GROUP INC, 2006) Rollan, Antonio; Ferreccio, Catterina; Gederlini, Alessandra; Serrano, Carolina; Torres, Javiera; Harris, Paul
    AIM: To validate a non-invasive method to detect gastric mucosal atrophy in a Chilean population with high prevalence of gastric cancer and a poor survival rate.
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    Phytoplasma and virus detection in commercial plantings of Vitis vinifera cv. Merlot exhibiting premature berry dehydration
    (UNIV CATOLICA DE VALPARAISO, 2008) Matus, Jose Tomas; Vega, Andrea; Loyola, Rodrigo; Serrano, Carolina; Cabrera, Soledad; Arce Johnson, Patricio
    A new and devastating physiological disorder of Vitis vinifera cv. Merlot was recently reported, known as premature berry dehydration (PBD), which is characterized by plant growth reduction, induction of general senescence and pedicel necrosis in the fruit, causing significant reductions in vineyard production. The causes of this disease remain unclear and previous reports suggest that it may be associated with phloem disruption and water provision. For this reason, any factor causing phloem disturbances could cause an important change in the berry water status. As some micro-organisms have been reported to disrupt phloem flow, we analyzed the occurrence of phytoplasma and viruses in commercial vineyards presenting PBD. In this study, a phytoplasma was detected by electron microscopy and nested PCR while virus infections were diagnosed by RT-PCR in samples collected during two growing seasons. The presence of phytoplasma only in samples from grape plants with PBD suggests that this pathogen may be one of the causal agents of this disorder. We suggest that the influence of other factors, such as virus infections, agronomic handling and environmental conditions also modulate berry dehydration. This is the first study at the microscopic and molecular levels that correlates phytoplasma presence with PBD.
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    Prevalence of Helicobacter pylori Antimicrobial Resistance Among Chilean Patients
    (2021) Gonzalez-Hormazabal, Patricio; Arenas, Alex; Serrano, Carolina; Pizarro, Margarita; Fuentes-Lopez, Eduardo; Arnold, Jorge; Berger, Zoltan; Musleh, Maher; Valladares, Hector; Lanzarini, Enrique; Jara, Lilian; Castro, V. Gonzalo; Camargo, M. Constanza; Riquelme, Arnoldo
    Background. Treatments for Helicobacter pylori (H. pylori) eradication include the use of antibiotics and a proton-pump inhibitor. Antibiotic resistance is a major concern for two drugs: levofloxacin and clarithromycin. The aim was to determine the prevalence of levofloxacin resistance (LevoR) and clarithromycin resistance (ClaR) in an urban population in Santiago, Chile.
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    Relationship between Helicobacter pylori virulence factors and regulatory cytokines as predictors of clinical outcome
    (2007) Serrano, Carolina; Diaz, Maria Ines; Valdivia, Alejandra; Godoy, Alex; Pena, Alfredo; Rollan, Antonio; Kirberg, Arturo; Hebel, Eduardo; Fierro, Jaqueline; Klapp, Gabriela; Venegas, Alejandro; Harris, Paul R.
    Helicobacter pylori infection is highly prevalent in Chile (73%). Usually a minority of infected patients develops complications such as ulcers and gastric cancer that have been associated with the presence of virulence factors (cagA, vacA) and host T helper response (Th1/Th2). Our aim was to evaluate the relationship between strain virulence and host immune response, using a multiple regression approach for the development of a model based on data collected from H. pylori infected patients in Chile. We analyzed levels of selected cytokines determined by ELISA (interleukin (IL)-12, IL-10, interferon (IFN)-gamma and IL-4) and the presence of cagA and vacA alleles polymorphisms determined by PCR in antral biopsies of 41 patients referred to endoscopy. By multiple regression analysis we established a correlation between bacterial and host factors using clinical outcome (gastritis and duodenal ulcer) as dependent variables. The selected model was described by: clinical outcome = 0.867491 (cagA) + 0.0131847 (IL-12/IL-10) + 0.0103503 (IFN-gamma/IL-4) and it was able to explain over 90% of clinical outcomes observations (R-2=96.4). This model considers that clinical outcomes are better explained by the interaction of host immune factors and strain virulence as a complex and interdependent mechanism. (c) 2007 Elsevier Masson SAS. All rights reserved.