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| 1 | Helicobacter pylori CagA protein polymorphisms and their lack of association with pathogenesis显示文摘AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPI-YA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using χ2 test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation. | Nicole Acosta Andrés Quiroga Pilar Delgado María Mercedes Bravo Carlos Jaramillo | 2010 | World Journal of Gastroenterology2010，16，31： | 5 |
| 2 | Study of reverse osmosis membranes fouling by inorganic salts and colloidal particles during seawater desalination显示文摘Fouling phenomenon is considered among the major reasons that cause significant increase of operating cost of desalination plants equipped with reverse osmosis(RO)membranes.This phenomenon is studied in the present work in the case of RO polyamide aromatic membranes using model seawater containing inorganic salts and colloidal compounds.Different solubility conditions of CaCO3 and CaSO4 were applied to study RO performances with and without colloid presence.During experiments,the membrane permeate fluxes were continuously monitored.Moreover,studies of chemical composition,structure,and morphology of the materials deposited on the membrane surface were conducted using energy dispersive microanalysis(EDS)X-ray diffraction and scanning electronic microscopy(SEM).Results show that in conditions of calcium carbonate oversaturation there is a reduction in the permeate flow of 11.2%due to fouling of the membrane by the precipitation of this compound.While in the same conditions of calcium sulphate oversaturation the reduction of the flow is 5%,so we can conclude that in conditions of oversaturation of both salts,calcium carbonate produces a greater fouling of the membrane that in its view causes greater decrease in the flow of permeate.All this based on the results of the test with both salts in oversaturated conditions.Resulting in the formation of calcite and gypsum crystals onto the membranes as XRD analyses stated.Additional presence of colloidal silica in those conditions intensifies strongly the fouling,leading until to 24.1%of permeate flux decrease. | Santiago Gutiérrez Ruiz Juan Antonio López-Ramírez Mohammed Hassani Zerrouk Agata Egea-Corbacho Lopera JoséMaría Quiroga Alonso | 2020 | Chinese Journal of Chemical Engineering2020，28，3： | 5 |
| 3 | CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses显示文摘AIM: To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori ) strains from Colombia on the host cell biology. METHODS: Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n=17), atrophic gastritis (n=17), duodenal ulcer (n=16), intestinal metaplasia (n=16) and gastric cancer (n=18), were included. To determine the integrity of the cag pathogenicity island (cag PAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGS gastric epithelial cellswere infected with each strain and assayed for translo-cation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of 'hummingbird' cells (>15 μm) was determined. RESULTS: Overall 72% (60/84) of the strains were found to harbor a functional cag PAI. Levels of phos-phorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gas-tritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P < 0.02; 49.1% ± 23.1% vs 26.2%±14.8%, P<0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P<0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P < 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL,P < 0.0001). We did not observe differences in the extent of cell elongation induction between strains with a functional or a defective cagPAI in 6 h cocultures. At 24 h post infection strains with functionalcagPAI showed high diversity in the extent of hummingbird phenotype induction ranging from 7% to 34%. cag PAI defective strains induced significantly lower levels of elongation than strains with functional cag-PAI with one or more than one EPIYA-C motif (15.1% ± 5.2%vs 18.9% ± 4.7%,P < 0.03; and 15.1% ± 5.2% vs 20.0% ± 5.1%, P < 0.003 respectively). No differences were observed in cellular elongation inductionor IL-8 expression among H. pylori strains bearing one and more than one EPIYA-C motifs, neither at 6 h nor at 24 h of coculture. There were no associations between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs or pathology. CONCLUSION: The present work describes a lack of association between H. pylori CagA protein EPIYA motifs variations from Colombian isolates and disease-associated cellular responses. | Carlos Alberto Fajardo Andrés Javier Quiroga Andrea Coronado Karen Labrador Nicole Acosta Pilar Delgado Carlos Jaramillo María Mercedes Bravo | 2013 | World Journal of Gastrointestinal Oncology2013，5，3： | 3 |
| 4 | Propolis from the northwest of Argentina as a source of antifungal principles显示文摘 | QUIROGA E N SAMPIETRO D A SOBERON J R | 2006 | J Appl Microbiol2006，101，1： | 1 |
| 5 | Immobilized Rh,Ru,Pd and Ni complexes as catalysts in the hydrogenation of cyclohexene显示文摘 | CAGNOLA E A QUIROGA M E LIPRANDI D A LARGENTIERE P C | 2004 | Appl Catal A:Gen2004，274，1： | 1 |
| 6 | Carbon contents and respiration rates of aggregate size fractions under no-till and conventional tillage显示文摘 | Fernández R Quiroga A Zorati C Noellemeyer E | 2010 | Soil Till Res2010，109，2： | 1 |
| 7 | Trial of complete weaning from immunosuppression for liver transplant recipients: Factors predictive of tolerance显示文摘 | Rocío García Garza Pablo Sarobe Juana Merino Juan J. Lasarte Delia D’Avola Virginia Belsue José A. Delgado Leyre Silva Mercedes I?arrairaegui Bruno Sangro Jesus J. Sola Fernando Pardo Jorge Quiroga J. Ignacio Herrero | 2013 | Liver Transpl2013，，9： | 1 |
| 8 | Comparative studies of reverse osmosis membranes for wastewater reclamation显示文摘 | Lopez J A Coello M D Quiroga J M | 2006 | Desalination2006，191，13： | 1 |
| 9 | Travel time studies with global positioning and geographic information systems: an integrated methodology显示文摘 | QUIROGA C A | 1998 | Transportation Research Part C1998，6，1： | 1 |
| 10 | Flow cytometric analysis of T-lymphocytes from nasopharynx-associated lymphoid tissue (NALT) in a model of secondary immunodeficiency in Wistar rats显示文摘 | Gustavo Adolfo Sosa María Florencia Quiroga María Estela Roux | 2008 | Immunobiology2008，，5： | 1 |
| 11 | Determination of sample sizes for travel time studies显示文摘 | Quiroga C A Bullock D | 1998 | ITE Journal on the Web1998，68，8： | 1 |
| 12 | Carboncontents and respiration rates of aggregate size fractionsunder no-till and conventional tillage显示文摘 | Fernandez R Quiroga A Zorati C Noellemeyer E | 2010 | Soil and TillageResearch2010，109，10： | 1 |
| 13 | Screening antifungal activities of selected medicinal plants显示文摘 | QUIROGA E N SAMPIETRO A R VATI3JONE M A | 2001 | J Ethnopharmacol2001，74，1： | 1 |
| 14 | Recombinant interferon-γ as adjuvant to hepatitis B vaccine in hemodialysis patients 显示文摘 | QUIROGA J A CASTILLO I PORRES J C | 1990 | Hepatology1990，12，4： | 1 |
| 15 | A tomato peroxidase involved in the synthesis of lignin and suberin显示文摘 | QUIROGA M GUERRERO C BOTELLA M A | 2000 | Plant Physiology2000，122，： | 1 |
| 16 | Demodulation of carrier fringe patterns by the use of non-recursive digital phase locked loop 显示文摘 | Servin M Quiroga J A Cuevas F J | 2001 | Opt Commun2001，200，： | 1 |
| 17 | Determination of Sample Size for Travel Time Studies 显示文摘 | Quiroga c A Buliock D | 1998 | ITE Journal1998，68，8： | 1 |
| 18 | Screening antifungal activities of selected medicinal plants 显示文摘 | Quiroga E N Sampietro A R Vattuone M A | 2001 | J Ethnopharmacol2001，74，： | 1 |
| 19 | Immobilized Rh,Ru,Pd and Ni complexes as catalysts in the hydrogenation of cyclohexene显示文摘 | CAGNOLA E A QUIROGA M E LIPRANDI D A L'ARGENTIRE P C | 2004 | Appl Catal A2004，274，12： | 1 |
| 20 | Segregation of alloying elements during the hot-dip coating solidification process显示文摘 | ZAPPONI M QUIROGA A PEREZ T | 1999 | Surface and Coatings Technology1999，122，12： | 1 |
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