经济学人-感染病毒时进食 感染细菌时禁食.doc

经济学人:感染病毒时进食 感染细菌时禁食Scienceandtechnology:Medicaltreatment:Feedavirus,starveabacterium科学与技术：医疗：感染病毒时进食，感染细菌时禁食Anoldwivestalegetssomesupportfrommedicalscience.无稽之谈获医学证实。Whetheritisbesttofeedafeverandstarveacold,orviceversa,varieswiththegrandparentbeingasked.要说是发烧时宜吃，伤风时宜饿呢，还是反之为佳？不同的祖父母回答是不一样的。Medicinehasdecidedthatitisalwaysabadideatodenyfoodtotheill.医疗界已经判定，生病时拒绝进食总非良策。Nowanewstudysuggeststhatbyignoringsucholdwivestales,medicsmayhavemissedatrick.现有一项新研究表明，若忽视这类无稽之谈，医疗人员可能会错过机会。ApaperjustpublishedinCellbyateamofresearchersledbyRuslanMedzhitovatYaleUniversitysuggestthatforce-feedingmiceinfectedwithinfluenzakeepsthemalivebutdoingthesametomicewithbacterialinfectionsisfatal.由耶鲁大学鲁斯兰麦哲托夫带领的团队近日在细胞上发表的研究表明，患有流感的老鼠受到强行喂食尚能活命，而对有细菌感染的老鼠却是致命的。DrMedzhitovwasinspiredbyexperimentsconductednotbymedics,butbyzoologists.麦哲托夫博士受到动物学家 (而非医生) 所做的实验启发。Mostanimalsinstinctivelyrespondtoinfectionbycuttingbackonfood,andaslewofstudiesinrecentyearshaveshownthatwhendiseasedanimalsareforce-fedtheyaremorelikelytodiethaniftheyareallowedtoabstain.大多数动物受到感染后，会本能地减少进食，并且近年来大量研究表明，强制给生病的动物喂食比允许其抑制进食更易致死。ButDrMedzhitovwonderedwhetherthatheldtrueforalltypesofdisease.但麦哲托夫博士好奇这是否适用于各类疾病。Toinvestigate,heandhisteaminfectedonegroupofmicewithamurineinfluenzavirus,andtheotherwithListeriamonocytogenes,abacteriumthatcausesfoodpoisoning.为了进一步调查，麦哲托夫博士和他的团队使一组老鼠感染流感病毒，另一组感染能引发食物中毒的李斯特菌。Somemiceineachgroupwereforce-fedrodentchow,whileotherswereforce-fednutrition-freesaline.每组中，给一部分老鼠强迫喂食鼠类饲料，而给另一部分老鼠注射无营养的生理盐水。Everysinglemousethatwasinfectedwiththebacteriumdiediftheyweregivenfood,buthalfsurvivedonthesaline.感染细菌又被强迫喂食物的老鼠全部死亡，而被注射生理盐水的老鼠存活率达到一半。Theresultsoftheviralinfectionwerelessstark,butstillclear: 77.8%ofinfectedmicesurvivedifgivenfood,butonly10%didsowhengivensaline.虽然病毒实验结果不那么残酷，但依然分明：其中被强迫喂食的老鼠存活率77.8%，而被注射生理盐水的老鼠存活率仅为10%.Oneclueastowhatmightbegoingonliesinthefact,identifiedinearlierresearch,thatcellsinfectedwithbacteriaoftenprefertoburnfatinsteadofglucose,theirusualfuel.导致这个结果可能的原因之一就在于受细菌感染的细胞通常倾向于燃烧脂肪而非葡萄糖 (平常的燃料)，这也得到早期研究的证实。Furtherexperimentsledtheteamtoconfirmthatglucosespecificallywasthekeytosurvivalinbothviralandbacterialinfections.进一步的实验使团队确定，葡萄糖在病毒感染和细菌感染中起到了性命攸关的作用。Aswiththerodentchow,micewithbacterialinfectionsthatwerefedglucosedied.对感染细菌的老鼠喂食物或葡萄糖都致死。Butinfectedmicefedaversionofglucosethattheycouldnotmetaboliselived.但当感染细菌的老鼠被喂食一类无法参与新陈代谢的葡萄糖时反而存活。Again,thoseresultswerenearlyreversedinmicesufferingfromaviralinfection.然而，受到病毒感染的老鼠结局几乎相反。Allofthosefedtheunusablevariantofglucosediedwithintendays; 40%ofthosefedtheordinarystuffsurvived.被喂食无法食用的变异葡萄糖的老鼠在10天之内全部死亡，喂食普通食物的老鼠中则有40%存活下来。Theglucoseseemedtomakenodifferencetothebugs,nortotheimmunesystemsofthemice.葡萄糖似乎对轻微的传染病和老鼠的免疫系统没有什么影响。Instead,italteredthebiologyoftheinfectedcells.相反，它转变了受感染细胞的机理。Inviralinfections,manyinfestedcellswerecommittingsuicide,acellularscorched-earthstrategydesignedtoslowthespreadofthevirus.在病毒感染中，许多受感染的细胞都在自杀，这种焦土政策旨在减缓病毒的传播。Providingglucoseseemedtobolstertheirabilitytofighttheinfectionwithoutresortingtosuchdrasticmeasures.而葡萄糖似乎只想要加强他们对抗感染的能力，而非诉诸于自杀这种极端的措施。Theoppositewastrueforbacteria.Burningfatprotectedinfectedmice.相反，葡萄糖对细菌感染影响重大。燃烧脂肪保护了受感染的老鼠。Butswampingthecellswithglucosecausedthemtoproduceprodigiousquantitiesofhighlyreactivechemicalsknownasfreeradicals,whichdamagecells.但给细胞灌满葡萄糖会使它们产生数量庞大的高度活跃化学物质，即破坏细胞的自由基。Thatcollateraldamagemadesurvivallesslikely.这种附带损害使老鼠更难存活。Theprecisebiologicaldetailsofwhyglucoseisgoodforviralinfectionsandbadforbacterialonesarenotyetknown.葡萄糖对病毒感染有益却对细菌感染有害的具体生物学细节还尚未可知。AndDrMedzhitovsresultswillhavetobetestedinhumansbeforemedicscanapplythem.在医护人员运用研究结果之前，麦哲托夫博士仍需要做临床试验。Buttheyareausefulreminderthatthereissometimesgenuinewisdomhiddeninfolksyhomilies.但这些成果依然有效地提醒人们：有时候民间俗语中还是蕴含着大智慧的。1.force-feeding强制进食例句:Productionofthefoiegrasptinvolvesforce-feedinggeeseandduckssothattheirliversswell.鹅肝酱的制作需要给鹅和鸭子强行喂食，以使它们的肝胀大起来。2.viralinfections病毒感染例句:Warmlemonwateristhemosteffectivewaytodiminishviralinfectionsandtheirsubse