简介：Traumaticbraininjury(TBI)isamajorpublichealthproblemthroughouttheworld.Morethan400000patientswithTBIintheUnitedStatesofAmericaandmorethanamillionpatientswithTBIinChinaareadmittedtohospitaleveryyear.HeadtraumaisalsoNo.1killerofyoungpeopleinthedevelopedcountriesaswellasinsomedevelopingcountries.Unfortunately,theoutcomeofpatientswithsevereTBIisstillpoorallovertheworld.ThemortalityofsevereTBIpatients(GCS3-8)inmajorityofhospitalsisover30%andverysevereTBIpatients(GCS3-5)isover80%withonly15%functionalrecovery.1,2However,recentadvanceincerebralprotectionbymild(35-33℃)tomoderatehypothermia(32-30℃)iscertainlyencouraging,whichbringsneurosurgeonsthehopetoimprovetheoutcomeofsevereheadinjuredpatients.

简介：Objective:　Toexplorethevariantprocessesofcellapoptosisandtheinhibitingeffectofmoderatehypothermiaoncellapoptosisafterdiffusebraininjury.　　Methods:　ModelsofdiffusebraininjurywereinducedbythetraumadevicereportedbyMarmarou.1Atotalof128Wistarratsweredividedinto4groups:theuninjuredgroup(GroupA,n=8),theseverelyinjuredgroup(GroupB,n=60),themildlyinjuredgroup(GroupC,n=30)andthemildhypothermiagroup(GroupD,n=30).InGroupD,theseverelyinjuredratsweretreatedwithmoderatehypothermiatokeeptherectaltemperatureat32℃(standarddeviationfor0.1℃)for6hours.Thenthemorphosis,thecharacteristicsandthequantityofapoptoticcellsinthecerebralcortexandinthehippocampusregionsafterdifferentseveritiesofcraniocerebralinjurieswereobservedandcomparedunderanelectronicmicroscope,withterminaldeoxynucleotidylnickendlabeling(TUNEL)inDNAfragmentationandwithagarosegelelectrophoresis.　　Results:　TUNELshowedapoptoticcellsincreasedaccordingtotheinjuryseverity,andtheypeakedat48hoursafterinjuryandthendeclined.InGroupC,apoptosiswaslocatedintheCA2andCA3areasofthehippocampus.AndinGroupB,apoptosisincreasedevidently,andlocatedinthewholehippocampusandinthefrontalandparietalcortexregions.Thehypothermia-treatedratshadsomeapoptoticcells,too.However,evenat24,48and72hoursafterinjurythereweresignificantlyfewerapoptoticcellsinthecortexandinthehippocampusinGroupDthanthatinthenon-treatedgroups.Electronmicroscopyshowedthattheapoptoticcellswereroundandshrunkeninmorphologyandthenucleiwereroundandcondensedat24and48hoursafterinjury.Andtheapoptosisat48hourswasmoreseverethanthatat24hours.Thehypothermia-treatedratshadnoapoptoticcells.GelelectrophoresisshowedthatcharacteristicDNA“ladders”wereobservedinthecortexandinthehippocampusat48hoursafters

简介：Objective:Toinvestigatetheeffectofmoderatehypothermiaonresponsesofaxonalcytoskeletontoaxonalinjuryintheacutestageofinjury.Methods:Offifteenadultguineapigs,twelveanimalsweresubjectedtostretchinjurytotherightopticnervesanddividedintothenormothermicgroup(n=6)inwhichtheanimal'scoretemperaturewasmaintainedat36.0-37.5℃andthehypothermiagroup(n=6)inwhichthecoretemperaturewasreducedto32.0-32.5℃afterstretchinjury.Remainingthreeanimalssustainednoinjurytotherightopticnervesandservedascontrolgroup.Halfofinjuredanimals(n=3)ofeithernormothermicgrouporhypothermicgroupwerekilledateither2hoursor4hoursafterinjury.Theultrastructuralchangesofaxonalcytoskeletonoftherightopticnervefibersfromtheanimalswereexaminedunderatransmissionelectronmicroscopeandanalyzedbyquantitativeanalysiswithacomputerimageanalysissystem.Results:At2hoursafterstretchinjury,therewasasignificantreductioninthemeannumberofmicrotubules(P<0.001),andasignificantincreaseinthemeanintermicrotubulespacing(P<0.05orP<0.01)inaxonsofallsizesinnormothermicanimals.Themeannumberofneurofilamentsalsodecreasedstatistically(P<0.01)inlargeandmediumsubgroupsofaxonsinthesameexperimentalgroupat2hours.By4hours,thelargesubgroupofaxonsinnormothermicanimalsstilldemonstratedasignificantdeclineinthemeannumberofmicrotubules(P<0.01)andanincreaseinthemeanintermicrotubulespacing(P<0.05),whilethemediumandsmallsubgroupsofaxonsdisplayedasignificantincreaseinthemeannumberofneurofilaments(P<0.05)andreductioninthemeaninterneurofilamentspacing(P<0.05).Onthecontrary,eitherthemeannumberofmicrotubulesandthemeanintermicrotubulespacing,orthemeannumberofneurofilamentsandinterneurofilamentspacinginaxonsofallsizesinhypothermicstretch-injuredanimalswasnotsignificantdifferentfromthemeanvaluesofsham-operated