简介:Colorectalcarcinoma(CRC)isacommoncauseofmorbidityandmortalityworldwide.TwopathogenicpathwaysareinvolvedinthedevelopmentofadenomatoCRC.ThefirstpathwayinvolvesAPC/β-catenincharacterizedbychromosomalinstabilityresultingintheaccumulationofmutations.ThesecondpathwayischaracterizedbylesionsinDNAmismatchrepairgenes.AberrantDNAmethylationinselectedgenepromotershasemergedasanewepigeneticpathwayinCRCdevelopment.CRCscreeningisthemostefficientstrategytoreducedeath.SpecificDNAmethylationeventsoccurinmultistepcarcinogenesis.EpigeneticgenesilencingisacausativefactorofCRCdevelopment.DNAmethylationshavebeenextensivelyexaminedinstoolfromCRCandprecursorlesions.ManymethylatedgeneshavebeendescribedinCRCandadenoma,althoughnodefiniteDNAmethylationbiomarkerspanelhasbeenestablished.MultipleDNAmethylationbiomarkers,includingsecretedfrizzled-relatedprotein2,secretedfrizzled-relatedprotein1,tissuefactorpathwayinhibitor2,vimentin,andmethylguanineDNAmethyltransferase,havebeenfurtherinvestigated,andobservationshaverevealedthatDNAmethylationbiomarkersexhibitwithhighsensitivityandspecificity.ThesemarkersmayalsobeusedtodiagnoseCRCandadenomainearlystages.Realtimepolymerasechainreaction(qPCR)issensitive,scalable,specific,reliable,timesaving,andcosteffective.Stoolexfoliatedmarkersprovideadvantages,includingsensitivityandspecificity.AstoolqPCRmethylationtestmayalsobeanenhancedtoolforCRCandadenomascreening.
简介:Romanticismisanimportantstageintheevolutionofman’sself-consciousness.Itshowsnewinterestinandnewconcernwithmanandnature.Wordsworthiswell-knownasanaturepoet.Thethemeofhumanmindandnatureinhispoemshaslongattractedreaders’attention.However,hedoesnotindulgeinnatureitselfbuttakesitasconsolationandinspirationforhumankind.Inordertohighlightthepoet’sconcernwithhumanmind,thepresentpaperchoosestoexploreWordsworth’sconcernwithchildren’smind,basedontheanalysisofWordsworth’sThePreludeandmanyofhispoemsaboutchildren.