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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 | 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 |
| 3 | Impromved diagnosis of hepatic perfusion disorders:value of hepatic arterial phase imaging during helical CT显示文摘 | Quiroga s Sebastia C Pallisa E | 2001 | RadioGraphics2001，21，1： | 1 |
| 4 | Family Ownership and Firm Performance: Evidencefrom Public Companies in Chile显示文摘 | MARTINEZ J I STOHR B S QUIROGA B F | 2007 | Family Business Review2007，20，2： | 1 |
| 5 | Complications of orthoto pic liver transplantation:spectrum of findings with helical CT显示文摘 | Quiroga S Sebastia MC Margarit C | 2001 | Radiographics2001，21，5： | 1 |
| 6 | Improved diagnosis of hepatic peffusion disorders:value of hepatic arterial phase imaging during hehcM CT显示文摘 | QUIROGA S SEBSTIA C PALLISA E | 2001 | Radiog-raphics2001，21，1： | 1 |
| 7 | Complications of orthotopic liver transplantation: spectrum of findings with helical CT显示文摘 | Quiroga S Sebastia MC Margarit C | 2001 | Radiographics2001，21，5： | 1 |
| 8 | Hemoperitoneum as a First Manifestation of Hepatocellular Carcinoma in Western Patients with Liver Cirrhosis显示文摘 | Lluís Castells Margarita Moreiras Sergi Quiroga Agustí Alvarez-Castells Antonio Segarra Rafael Esteban Jaime Guardia | 2001 | Digestive Diseases and Sciences2001，，3： | 1 |
| 9 | Three-dimensional shape analysis of coarse aggregates: New techniques for and preliminary results on several different coarse aggregates and reference rocks 显示文摘 | ERDOGAN S T QUIROGA P N FOWLER D W | 2006 | Cem Concr Res2006，36，9： | 1 |
| 10 | Hemoperitoneum as a First Manifestation of Hepatocellular Carcinoma in Western Patients with Liver Cirrhosis显示文摘 | Lluís Castells Margarita Moreiras Sergi Quiroga Agustí Alvarez-Castells Antonio Segarra Rafael Esteban Jaime Guardia | 2001 | Digestive Diseases and Sciences2001，，3： | 1 |
| 11 | Effects of pentoxifylline on inflammatory parameters inchronic kidney disease patients: a randomized trial 显示文摘 | GOICOECHEAM GARC A DE VINUESA S QUIROGA B etal | 2012 | JNephrol2012，25，6： | 1 |
| 12 | Noradrenaline-and melantin-mediated regulation of pigment aggregation in fish melanophore显示文摘 | Aspengren S Skold HN Quiroga G | 2003 | Pigment Cell Res2003，16，： | 1 |
| 13 | Improved diagnosis of hepatic perfusion disorders:value of hepatic arterial phase imaging during helical CT显示文摘 | Quiroga S Sebastia C Pallisa E | 2001 | Radio Graphics2001，21，1： | 1 |
| 14 | Aortic stenesis:spectrum of diseases depicted at multi-section CT显示文摘 | Sebastia C Quiroga S Boye R | 2003 | Radiographics2003，23，5： | 1 |
| 15 | Aortic stenosis : spectrum of diseases depicted at multisession CT显示文摘 | Sebastia C Quiroga S Boye R | 2003 | Radio Graphics2003，23，： | 1 |
| 16 | Ni-W coatings electrodeposited on carbon steel: Chemical composition, mechanical properties and corrosion resistance 显示文摘 | QUIROGA ARGANARAZ M P RIBOTTA S B FOLQUER M E GASSA L M BENITEZ G VELA M E SALVAREZZA R C | 2011 | Electrochimica Acta2011，56，17： | 1 |
| 17 | 显示文摘 | QUIROGA J INSUASTY B CRUZ S | 1998 | J Heterocycl Chem1998，35，： | 1 |
| 18 | Complications of orthotopic liver transplantation: spectrum of findings with helical CT显示文摘 | Sebastia MC Margarit C | 2001 | Radiographics2001，21，5： | 1 |
| 19 | Improved diagnosis of hepatic perfusion disorders: value of hepatic arterial phase imaging during helical CT显示文摘 | Quiroga S Sebastia C Pallisa E | 2001 | Radiographics2001，21，1： | 1 |
| 20 | Aortic dissection:diagnosis and follow-up with helical CT显示文摘 | Sebastia C Pallisa E Quiroga S | 1999 | Radiograpics1999，19，： | 1 |
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