|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | MGMT and MLH1 methylation in Helicobacter pylori-infected children and adults显示文摘AIM:To evaluate the association between Helicobacter pylori(H.pylori) infection and MLH1 and MGMT methylation and its relationship with microsatellite instability(MSI).METHODS:The methylation status of the MLH1 and MGMT promoter region was analysed by methylation specific methylation-polymerase chain reaction(MSPPCR) in gastric biopsy samples from uninfected or H.pylori-infected children(n = 50),from adults with chronic gastritis(n = 97) and from adults with gastric cancer(n = 92).MLH1 and MGMT mRNA expression were measured by real-time PCR and normalised to a constitutive gene(β actin).MSI analysis was performed by screening MSI markers at 4 loci(Bat-25,Bat-26,D17S250 and D2S123) with PCR;PCR products were analysed by single strand conformation polymorphism followed by silver staining.Statistical analyses were performed with either the χ 2 test with Yates continuity correction or Fisher's exact test,and statistical significance for expression analysis was assessed using an unpaired Student's t-test.RESULTS:Methylation was not detected in the promoter regions of MLH1 and MGMT in gastric biopsy samples from children,regardless of H.pylori infection status.The MGMT promoter was methylated in 51% of chronic gastritis adult patients and was associated with H.pylori infection(P < 0.05);this region was methylated in 66% of gastric cancer patients,and the difference in the percentage of methylated samples between these patients and those from H.pylori-infected chronic gastritis patients was statistically significant(P < 0.05).MLH1 methylation frequencies among H.pylori-infected and non-infected chronic gastritis adult patients were 13% and 7%,respectively.We observed methylation of the MLH1 promoter(39%) and increased MSI levels(68%) in samples from gastric cancer patients in comparison to samples from H.pylori-infected adult chronic gastritis patients(P < 0.001 and P < 0.01,respectively).The frequency of promoter methylation for both genes was higher in gastric cancer samples than in H.pylori-positive chronic gastritis samples(P < 0.05).The levels of MLH1 and MGMT mRNA were significantly reduced in chronic gastritis samples that were also hypermethylated(P < 0.01).CONCLUSION:In summary,MGMT and MLH1 methylation did not occur in earlier-stage H.pylori infections and thus might depend on the duration of infection. | Marisa C Alvarez Juliana C Santos Nathália Maniezzo Marcelo S Ladeira Artur LC da Silva Isabel CA Scaletsky José Pedrazzoli Jr Marcelo L Ribeiro | 2013 | World Journal of Gastroenterology2013，19，20： | 5 |
| 2 | Analysis of the ge- netic variability of PvMSP-3c among Plasmodium vivax in Brazil- ian field isolates 显示文摘 | Ribeiro RS Ladeira L Rezende AM | 2011 | Mena I Oswaldo Cruz2011，106，1： | 1 |
| 3 | Influence of the confinement, soil density and displacement rate on soil-geogrid interaction 显示文摘 | LOPES M L LADEIRA M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 4 | Relationship between fracture spacing and bed thickness显示文摘 | Ladeira F L Price N J | 1981 | Journal of Structural Geology1981，3，12： | 1 |
| 5 | Influence of the confinement,soil density and displacement rate on soil-geogrid interaction显示文摘 | Lopes M L Ladeira M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 6 | Influence of the confinement soil density and displacement rate on soil-geogrid interaction显示文摘 | LOPES M L LADEIRA M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 7 | Influence of the confinement,soil density and displacement rate on soil-geogrid interaction显示文摘 | LOPES M L LADEIRA M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 8 | Influence of the confinement, soil density and displacement rate on soil-geogrid interaction显示文摘 | LOPES M L LADEIRA M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 9 | Influence of the confinement soildensity and displacement rate on soilgeogrid interaction显示文摘 | Lopes M L Ladeira M | 1996 | Geotextile and Geomembranes1996，14，： | 1 |
| 10 | Relationship between fracture spacing and bed thickness显示文摘 | Ladeira F L Price N J | 1981 | Journal of Structural Geology1981，3，2： | 1 |
| 11 | Oilseeds in zebu cattle diet:intake,digestibility and performance显示文摘 | Bassi M S Ladeira M M Chizzotti M L | 2012 | Revista Brasileira de Zootecnia2012，41，2： | 1 |
| 12 | Influence of the confinement,soil density and displacement rate on soil-geogrid interaction显示文摘 | LOPES M L LADEIRA M | | 0，，14： | 1 |
| 13 | Influence of the confinement, soil density and displacement rate on soil-geogrid interaction显示文摘 | LOPES M L LADEIRA M | 1996 | Geotextiles and Geomembranes1996，14，10： | 1 |
| 14 | Forbidden periods in delay differential equations显示文摘 | CARVALHO L A LADEIRA L A MARTELLI M | 2000 | Portugaliae Math Port Math2000，57，： | 1 |
| 15 | Relationship between fracture spacing and bed thickness显示文摘 | Ladeira F L Price N J | | 0，，02： | 1 |
| 16 | Special symmetric periodic solutions of differential systems with distributed delay 显示文摘 | AZEVEDO K GADOTTI M LADEIRA L | 2007 | Nonlinear Analysis2007，67，： | 1 |
| 17 | A note on partial functional differential equations with statedependent delay显示文摘 | Hernández E Prokopczyk A Ladeira L | | 0，，： | 1 |
| 18 | Ephedrine versus phenylephrine: prevention of hypotension during spinal block for cesarean section and effects on the fetus 显示文摘 | Magalhaes E Goveia C S de Araujo Ladeira L C | 2009 | Rev Bras Anestesiol2009，59，1： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员