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1、NewDrugsMayTransformDown SyndromeRecentbreakthroughsmayleadtopharmacologicaltreatmentsforthechromosomaldisorderMar1,2014

2、ByJenniLaidmanGETTYIMAGESPeoplebornwithDownsyndromehavealwaysbeenconsideredtobeincurablydevelopmentallydelayed—untilnow.Inthepastfewyearsanumberoflaboratoriesha

3、veuncoveredcriticaldrugtargetswithindisabledchemicalpathwaysinthebrainthatmightberestoredwithmedication.AtleasttwoclinicaltrialsarecurrentlystudyingtheeffectsofsuchtreatmentsonpeoplewithDownsyndrome.NowgeneticistRogerReevesofJohnsHopkinsUniversitymayhavestumbledonanotherdrugtarget

4、—thisonewiththepotentialtocorrectthelearningandmemorydeficitssocentraltothecondition.Downsyndromeoccursinaboutonein1,000birthsannuallyworldwide.Itarisesfromanextracopyofchromosome21andtheoverexpressionofeachofthe300to500genesthechromosomecarries.“Ifyougobackevenasrecentlyas2004,re

5、searchersdidn'thavemuchofaclueaboutthemechanismsinvolvedinthisdevelopmentaldisability,”saysMichaelHarpold,chiefscientificofficerwiththeDownSyndromeResearchandTreatment Foundation.Butallthathaschanged.“Inthepastsixorsevenyearstherehavebeenseveralbreakthroughs—and‘breakthroughs’isno

6、tbyanymeanstoobigaword—inunderstandingtheneurochemistryinDownsyndrome,”Reevessays.Thisimprovedknowledgebasehasledtoaseriesofdiscoverieswiththerapeuticpromise,includingthelatestbyReeves.HeandhisteamwereattemptingtorestorethesizeofthecerebelluminmiceengineeredtoshowthehallmarksofDow

7、nsyndrome.Thecerebellumliesatthebaseofthebrainandcontrolsmotorfunctions,motorlearningandbalance.InpeoplewithDownsyndromeandintheDownmousemodelthecerebellumisabout40percentsmallerthannormal.Byrestoringitssize,Reeveshopedtogainaclearerpictureofthedevelopmentalprocessesthatleadtoanom

8、aliesinabrainwithDownsyndrome.Reeves'steaminjectednewbornDownmicewithachemicalthatstimulatesanimportantneurodevelopmentalpathwaythat,amongotherthings,orchestratescerebellumgrowth.“Wewerenotinfactsurprisedthatwefixedthecerebellum.Thatwasourworkinghypothesis,”Reevessays.Yethehadnota

9、nticipatedthatthreemonthsaftertre