Mechanistics insights of hydrogen peroxide transport through PIP aquaporins pore

Hydrogen peroxide (H2O2) is transported through membranes by aquaporins (AQP). In particular, some plant PIP aquaporins isoforms are efficient H2O2 channels. As water and H2O2 share physicochemical features, it was first supposed that all AQP that transport water could act as an H2O2 channel. However, experimental evidence showed that not all PIP that transport water can transport H2O2. So, the mechanism of H2O2 transport is still an unsolved issue for AQP channels. MtPIP2,3 is a plasma membrane AQP from the legume Medicago truncatula that permeates H2O2. To understand the structural and chemical selectivity mechanisms leading to H2O2 permeability in PIPs, we characterized the particularities of H2O2 passingthrough MtPIP2,3 pore by 1 μs atomistic molecular dynamic simulations. As PIPs are tetrameric pH gated channels we constructed homology MtPIP2,3 models in open and closed states, and with or without H2O2. All models were conformationally stable along the simulation and H2O2 permeation events were found in the simulations in the presence of this molecule. We find that: i- H2O2 molecules can cross the pore in a single file, iidihedral angles adopted by H2O2 along the pore Z axis present a different distribution compared to the angles visited in the solution; in the selectivity-determining NPA region, H2O2 adopts the wider range of dihedral angles, iii- higher residence times are located around the selectivity filter zone in the open channel and moves to the cytoplasmic filterarea in the closed channel; and iv- the constriction in the cytoplasmic filter area seems to be more stringent for H2O2 passage than for water.Our results shed light onto the molecular mechanism of H2O2 passage through MtPIP2,3 and represent the first steps to understand the structural determinants of AQP differential selectivity for these molecules and water.Fil: Chevriau, Jonathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Zeida, Ari. Universidad de la República; UruguayFil: Alleva, Karina Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaXLIX Reunión Anual de la Sociedad Argentina de BiofísicaArgentinaSociedad Argentina de Biofisic

Helicobacter pylori and corpus gastric pathology are associated with lower serum ghrelin

AIM To evaluate the association of Helicobacter pylori (H. pylori ), cagA genotype, and type of gastric pathology with ghrelin, leptin and nutritional status. METHODS Fasted dyspeptic adults (18-70 years) referred for an upper digestive endoscopy were enrolled in this crosssectional study. Height and weight were assessed for body mass index (BMI) calculation. A sociodemographic survey was administered and nutrient intake was evaluated with 24 h dietary recalls. Serum total ghrelin and leptin levels were analyzed by enzymelinked immunosorbent assay. 13 C-Urea Breath Test was performed and four gastric biopsies were obtained during endoscopy for histopathology and H. pylori DNA amplification and genotyping. Data analysis was performed using X 2 , Mann-Whitney U , Kruskal-Wallis tests, Spearman´s correlation and linear regression. RESULTS one hundred and sixty-Three patients (40.8 ± 14.0 years), 98/65 females/males, were included. Overall, persistent H. pylori prevalence was 53.4% (95%CI: 45.7%-65.8%). Neither nutrient intake nor BMI differed significantly between H. pylori positive and negative groups. Serum ghrelin was significantly lower in infected patients [median 311.0 pg/mL (IQR 230.0-385.5)] than in uninfected ones [median 355.0 pg/mL (IQR 253.8-547.8)] (P = 0.025), even after adjusting for BMI and gender (P = 0.03). Ghrelin levels tended to be lower in patients carrying cagA positive strains both in the antrum and the corpus; however, differences with those carrying cagA negative strains did not reach statistical significance (P = 0.50 and P = 0.49, respectively). In addition, the type and severity of gastric pathology in the corpus was associated with lower serum ghrelin (P = 0.04), independently of H. pylori status. Conversely, leptin levels did not differ significantly between infected and uninfected patients [median 1.84 ng/mL (0.80-4.85) vs 1.84 ng/mL (0.50-5.09), (P = 0.51)]. CONCLUSION H. pylori infection and severity of gastric corpus pathology are associated with lower serum ghrelin. Further studies could confirm a lower ghrelin prevalence in cagA-positive patients.Fil: Mantero, Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; ArgentinaFil: Matus, Gonzalo Sebastián. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Corti, Rodolfo Ernesto. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cabanne, Ana María. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Marchesi Olid, Liliana Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Escuela de Nutrición; ArgentinaFil: Piskorz, María Marta. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Zubillaga, Marcela Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Janjetic, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Goldman, Cinthia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas

Helicobacter pylori is a common component of the human stomach microbiota, possibly dating back to the speciation of Homo sapiens. A history of pathogen evolution in allopatry has led to the development of genetically distinct H. pylori subpopulations, associated with different human populations, and more recent admixture among H. pylori subpopulations can provide information about human migrations. However, little is known about the degree to which some H. pylori genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed H. pylori genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723 H. pylori strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from H. pylori populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American H. pylori subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.Fil: Muñoz Ramirez, Zilia Y.. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Pascoe, Ben. University of Bath; Reino UnidoFil: Mendez Tenorio, Alfonso. INSTITUTO POLITÉCNICO NACIONAL (IPN);Fil: Mourkas, Evangelos. University of Bath; Reino UnidoFil: Sandoval Motta, Santiago. Consejo Nacional de Ciencia y Tecnología; MéxicoFil: Perez Perez, Guillermo. New York University Langone Medical Center; Estados UnidosFil: Morgan, Douglas R.. University of Alabama at Birmingahm; Estados UnidosFil: Dominguez, Ricardo Leonel. Western Honduras Gastric Cancer Prevention Initiative Hospital de Occidente Santa Rosa de Copan; HondurasFil: Ortiz Princz, Diana. No especifíca;Fil: Cavazza, Maria Eugenia. No especifíca;Fil: Rocha, Gifone. Universidade Federal de Minas Gerais; BrasilFil: Queiroz, Dulcienne. Universidade Federal de Minas Gerais; BrasilFil: Catalano, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Goldman, Cinthia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Venegas, Alejandro. Universidad Diego Portales; ChileFil: Alarcon, Teresa. Universidad Autónoma de Madrid; EspañaFil: Oleastro, Monica. Universidade Nova de Lisboa; PortugalFil: Vale, Filipa F.. Universidade Nova de Lisboa; PortugalFil: Goodman, Karen J.. University of Alberta; CanadáFil: Torres, Roberto C.. Instituto Mexicano del Seguro Social; MéxicoFil: Berthenet, Elvire. Swansea University Medical School; Reino UnidoFil: Hitchings, Matthew D.. Swansea University Medical School; Reino UnidoFil: Blaser, Martin J.. Rutgers University; Estados UnidosFil: Sheppard, Samuel K.. University of Bath; Reino UnidoFil: Thorell, Kaisa. University of Gothenburg; SueciaFil: Torres, Javier. Instituto Mexicano del Seguro Social; Méxic

Helicobacter pylori heterogeneity in patients with gastritis and peptic ulcer disease

Genetic diversification allows Helicobacter pylori to persist during chronic colonization/infection. We investigated the intra-host variation of several markers that suggested microevolution in patients with chonic gastritis (CG) and peptic ulcer disease (PUD). One-hundred twenty-six isolates recovered from 14 patients with CG and 13 patients with PUD were analysed. cag pathogenicity island (cagPAI), oipA, vacA, bab gene status and the presence of jhp0926, jhp0945, jhp0947, jhp0949 and jhp0940 genes from the genomic Plasticity Zone (PZ) were taken into accout to investigate intra-host variation. lspA-glmMRFLP was performed to identify mixed infections. Only one patient was colonised/infected by two ancestrally unrelated strains. Among the 126 isolates, a significant association among cagPAI genotypes, oipA status and vacA alleles was indicated. Complete cagPAI, oipA ??on??, and vacA s1-m1 variants were significantly found in patients with PUD, without intra-host variations. Isolates from 7/14 patients with CG lacked babA in all chromosomal loci. In contrast, isolates from all or several biopsies of PUD patients carried babA, but in one patient only, the isolates showed positive Lewis b (Leb) binding assay. Considering cagPAI, vacA, oipA, bab genotypes, intra-host variation was also significantly higher in patients with CG. Conversely, a similarly high intra-host variation in almost PZ genes was observed in isolates from patients with CG and PUD. In conclusion, the lowest intra-host variation in cagPAI, oipA, vacA, and bab genes found in patients with PUD suggests the selection of a particular variant along the bacteria-host environment interplay during ulceration development. However, the predominance of this variant may be a refletion of the multifactorial etiology of the disease rather than the cause, as it was also found in patients with CG. The intra-host variation in PZ genes may predict that this genomic region and the other markers of microevolution studied evolve under diverse pressure(s).Fil: Armitano, Rita Ines. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Cátedra de Microbiología, Parasitología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Matteo, Mario José. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Cátedra de Microbiología, Parasitología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Goldman, Cinthia Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; ArgentinaFil: Wonaga, Andrés. Centro Integral de Gastroenterología; Argentina. Clínica Bazterrica. Servicio de Gastroenterología; ArgentinaFil: Viola, Luis Alberto. Centro Integral de Gastroenterología; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Catalano, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Mechanistic insight into pH gating in PIP aquaporins: role of specific loopD amino acids.

Aquaporins are membrane channels that transport water and other solutes. Their transport activity is regulated by different stimuli such as pH, binding of cations, phosphorylation/dephosphorylation or interaction with other proteins. All aquaporins share a general fold and tetrameric quaternary structure. Each protomer present two conserved regions that regulate the specificity of transport: the Asn-Pro-Ala (NPA) motives and the aromatic/arginine (Ar/R) selectivity filter. The plant PIP subfamily of aquaporins distinguish from other members of the family due to a longer intracellular loopD which is involved in its gating mechanism. The open/closed conformational transition in PIP channels is triggered by intracellular acidification, and different pH0,5 are found for homotetramers and heterotertamers form by PIP1 and PIP2 paralogues. Our goal is to elucidate the role of specific LoopD’ s amino acids in the modulation of PIP gating mechanism by intracellular pH. Our in vitro and in silico experiments, for wild type and mutant PIP show that: i- a conserved Leu residue in the cytoplasmic constriction is the structural element that determines pore blockage and, ii- a Pro residue present in PIP2 but not in PIP1 channels is involved in differential pH0.5 of homo and heterotetramers dose-response curves. So, two loopD residues, Leu 206 and Pro 194, works in combination with the pH sensor His 202 to control effective pore closing.Fil: Canessa Fortuna, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Vitali, Victoria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Chevriau, Jonathan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Zeida, Ari. Universidad de la República; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Alleva, Karina Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina20th Internaitional Congress of the INternational Union for Pure Applied Biophysics; 50th Annual Meeting of the Brazilian Society for Biochemistry and Molecular Biology; 45th Congress of Brazilian Biophysics Society anda 13th Brazilian Society on Nuclear Biosciences CongressBrasilSociedade Brasileira de Bioquímica e Biología Molecula

Occurrence of Mutations in the Antimicrobial Target Genes Related to Levofloxacin, Clarithromycin, and Amoxicillin Resistance in Helicobacter pylori Isolates from Buenos Aires City

Domain V of 23S rRNA, gyrA and gyrB Quinolones Resistance-Determining Region (QRDR), and pbp-1A gene point mutations were investigated in Helicobacter pylori-resistant isolates from three centres of Buenos Aires. Minimal inhibitory concentrations (MICs) were performed in 197 isolates from 52 H. pylori-positive naive patients by agar dilution method. Point mutations were achieved by amplification and sequencing of the target genes, and their association with resistance was determined by natural transformation assays. Resistance rates were as follows: metronidazole 28.8%, clarithromycin (CLA) 26.9%, levofloxacin (LEV) 32.7%, and amoxicillin (AMX) 7.6%. Nearly one-third of patients carried multidrug-resistant isolates. A2143G or A2142G in domain V of 23S-rRNA was found in all isolates showing high level of resistance to CLA (MIC >2 mg/L), accounting for 76.0% (38/50) of those with the resistant phenotype. The mutations A2267G or T1861C carried by 8/12 isolates with MIC 1–2 mg/L (low level) did not confer resistance by transformation. Substitutions at GyrA position 87 or 91, mainly N87K and D91G, were found in 92.8% (52/56) of the LEV-resistant isolates: 48 isolates with MIC 4–64 mg/L and 4/8 isolates with MIC 2 mg/L. The remaining four harboured K133N, also present in susceptible isolates. None of the substitutions in GyrB demonstrated to confer resistance. Transformation proved that PBP-1A N562Y and/or T556S substitutions confer the AMX resistance in our isolates, showing an additive effect. In conclusion, the usually reported mutations related to CLA, LEV, and AMX resistance were found in our isolates. However, low-level CLA resistance seems not to be due to mutations in Domain V of 23S rRNA gene.Fil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Mendiondo, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Wonaga, Andrés. Centro Integral de Gastroenterología; ArgentinaFil: Viola, Luis. Centro Integral de Gastroenterología; ArgentinaFil: Ibarra, Daniela. Hospital Aeronáutico Central; ArgentinaFil: Campitelli, Esteban. Hospital Aeronáutico Central; ArgentinaFil: Salim, Nicolas. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Corti, Rodolfo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Goldman, Cinthia Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Físico Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Catalano, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

Gating in plant plasma membrane aquaporins: the involvement of leucine in the formation of a pore constriction in the closed state

The control of water permeability in plant PIP2 aquaporins has become a paradigmatic case study of the capping mechanism for pore closure in water channels. From structural data, it has been postulated that the gating process in PIP2 involves a conformational rearrangement in cytosolic loopD that generates an obstruction to the transport of water molecules inside the aquaporin pore. BvPIP2;2 is a PIP2 aquaporin from Beta vulgaris whose pH response has been thoroughly characterized. In this work, we study the participation of Leu206 in BvPIP2;2 gating triggered by cytosolic acidification and show that this residue acts as a plug that blocks water transport. Based on data obtained from in silico and in vitro studies, we demonstrate that Leu206, one of the residues lining the pore, is responsible for ~ 60% of water blockage. Cell osmotic swelling experiments and atomistic molecular dynamics simulations indicate that the replacement of Leu206 by an Ala residue maintains high water permeability under conditions where the pore is expected to be closed. The present work demonstrates that Leu206, located at the cytoplasmic entry of the channel, constitutes a crucial pH-sensitive steric gate regulating water transport in PIP aquaporins.Fil: Canessa Fortuna, Agustina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; Argentina. Universidad Nacional de Hurlingham; ArgentinaFil: Aliperti Car, Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Armentia, Luciano. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; ArgentinaFil: Vitali, Victoria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; ArgentinaFil: Zeida, Ari. Universidad de la República; UruguayFil: Estrin, Dario Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Alleva, Karina Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Fisicomatemática. Cátedra de Física; Argentin

Dietary and anthropometric indicators of nutritional status in relation to Helicobacter pylori infection in a paediatric population

It has been postulated that Helicobacter pylori infection could affect growth and appetite, consequently influencing body weight. Therefore, the association between H. pylori infection and the dietary and anthropometric indicators of nutritional status of a paediatric population were investigated. A total of 525 children (aged 4-16 years) who were referred to the gastroenterology unit of the Sor Maria Ludovica Children's Hospital from Buenos Aires, Argentina, were enrolled and completed an epidemiological questionnaire. H. pylori infection was diagnosed using the 13C-urea breath test (13C-UBT). Height and weight were assessed for calculation of anthropometric indicators. Energy and macronutrient intakes were estimated by 24 h dietary recall. Data analysis was performed using a χtest, a Student's t test, a Mann-Whitney U test and linear and logistic regressions. The prevalence of H. pylori infection was 25·1 % (with a mean age of 10·1 (sd 3·1) years). A tendency towards lower energy, carbohydrate, protein and fat intakes was observed in infected patients; however, it was not associated with H. pylori infection in any of the evaluated age groups (4-8, 9-13 and 14-16 years). Underweight, stunting, overweight and obesity were also not associated with the infection. Although height-for-age and BMI-for-age Z scores tended to be lower in infected patients, the differences between H. pylori-positive and H. pylori-negative children were not statistically significant. In conclusion, H. pylori infection was not associated with dietary intake or with anthropometric indicators in the present population of children with gastrointestinal symptoms; however, an increased sample size would be needed to confirm the observed tendency towards lower dietary intake and lower anthropometric indicators of nutritional status in H. pylori-infected children.Fil: Janjetic, Mariana Andrea. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mantero, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Cueto Rua, Eduardo. Universidad de Buenos Aires. Facultad de Medicina. Escuela de Nutrición; ArgentinaFil: Balcarce, Norma. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Zerbetto de Palma, Gerardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Catalano, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Zubillaga, Marcela Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Boccio, José R.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Goldman, Cinthia Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin