简介：Inthisletter,acomparisonbetweenthreetypes(twolinearandonenonlinear)ofmodelsofskeletalmusclestiffnessisshown.ResultsarecomparedwithexperimentaldataforbicepsbrachiiinthecaseofmusclestretchingandwiththeHillequationforabiologicalmuscle.Itisshownthatresultsfornonlinearstiffnessmodelincaseoflength-forcerelationshipfitstotheexperimentaldata.

简介：AbstractSkeletal muscle plays an essential role in generating the mechanical force necessary to support the movement of our body and daily exercise. Compared with cardiac and smooth muscle, in mammals, skeletal muscle exhibits remarkable regenerative capacity in response to damage. Muscle stem cells, also known as satellite cells, directly contribute to regeneration. Here, we review primary and secondary myogenesis processes with a focus on muscle stem cells, as well as the function and regulation of muscle stem cells in adult muscle regeneration in mammals.

简介：Inmodernwarsbulletwoundscausedbysteelballsrepresentoneofthemajorkindsofcombatwounds,anddevelopingthecriteriafornecrosisoftissuesinsteel-ball-woundedorganismsisthereforeofgreatsignificanceforbothmilitaryandclini-calapplications.Severeinjuriescanbereadilyrecognizedbynakedeyes,butslighteronesareoftendifficulttobeidentifiedbyvisualexaminationorexperience.Moreoveritseemstobeunlikelytoestablishconsiatentcriteriaforvisualexaminationbecause

简介：Muscleactionsaretypicallydividedinto3categories：concentric,isometric,andeccentric.Anactivemusclethatisshorteningandproducespositivemechanicalworkissaidtoworkconcentrically;anactivemusclethatisnotchangingitslength,andthusdoesnotproducenetwork,issaidtoworkisometrically;andanactivemusclethatiselongatedbyexternalforces,andthusabsorbswork,orproducesnegativework,issaidtoworkeccentrically．1

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简介：Purpose:Theobjectiveofthepresentstudywastodeterminewhetheradenervatedmuscleextract(DmEx)couldstimulatesatellitecellresponseindenervatedmuscle.Methods:Wistarratsweredividedinto4groups:normalrats,normalratstreatedwithDmEx,denervatedrats,anddenervatedratstreatedwithDmEx.Thesoleusmuscleswereexaminedusingimmunohistochemicaltechniquesforproliferatingcellnuclearantigen,desmin,andmyogenicdifferentiationantigen(MyoD),andelectronmicroscopywasusedforanalysisofthesatellitecells.Results:Theresultsindicatethatwhiledenervationcausesactivationofsatellitecells,DmExalsoinducesmyogenicdifferentiationofcellslocalizedintheinterstitialspaceandtheformationofnewmusclefibers.AlthoughDmExhadasimilareffectinnatureoninnervatedanddenervatedmuscles,thisresponsewasofgreatermagnitudeindenervatedvs.intactmuscles.Conclusion:OurstudyshowsthattreatmentofdenervatedratswithDmExpotentiatesthemyogenicresponseinatrophicdenervatedmuscles.

简介：Theforcedlengtheningofanactivatedskeletalmusclehasbeentermedaneccentriccontraction（EC）.ThisreviewhighlightsthemechanicallyuniquenatureoftheECandfocusesonthespecificdisruptionofproteinswithinthecellknownascytoskeletalproteins.Themajorintermediatefilamentcytoskeletalprotein,desmin,hasbeenthefocusofworkinthisareabecausechangestodesminoccurwithinminutesofECsandbecausedesminhasbeenshowntoplaybothamechanicalandbiologicroleinamuscle＇sresponsetoEC.Itishopedthatthesetypesofstudieswillassistindecreasingtheincidenceofmuscleinjuryinathletesandfacilitatingthedevelopmentofnewtherapiestotreatmuscleinjuries.

简介：Background:Childrenareaffectedbydisordersthathaveanimpactontherespiratorymuscles.Inspiratorymusclefunctioncanbeassessedbymeansofthenoninvasivetension–timeindexoftheinspiratorymuscles(TTImus).OurobjectivesweretoidentifythedeterminantsofTTImusinhealthychildrenandtoreportnormalvaluesofTTImusinthispopulation.Methods:Wemeasuredweight,height,upperarmmusclearea(UAMA),andTTImusin96childrenaged6–18years.Thelevelandfrequencyofaerobicactivitywasassessedbyquestionnaire.Results:TTImuswassignificantlylowerinmalesubjects(0.095±0.038,mean±SD)comparedwithfemalesubjects(0.126±0.056)(p=0.002).TTImuswassignificantlylowerinregularlyexercising(0.093±0.040)comparedwithnonexercisingsubjects(0.130±0.053)(p<0.001).TTImuswassignificantlynegativelyrelatedtoage(r=-0.239,p=0.019),weight(r=-0.214,p=0.037),height(r=-0.355,p<0.001),andUAMA(r=-0.222,p=0.030).MultivariatelogisticregressionanalysisrevealedthatheightandaerobicexerciseweresignificantlyrelatedtoTTImusindependentlyofage,weight,andUAMA.ThepredictiveregressionequationforTTImusinmalesubjectswasTTImus=0.228-0.001×height(cm),andinfemalesubjectsitwasTTImus=0.320-0.001×height(cm).Conclusion:Gender,age,anthropometry,skeletalmuscularity,andaerobicexercisearesignificantlyassociatedwithindicesofinspiratorymusclefunctioninchildren.NormalvaluesofTTImusinhealthychildrenarereported.

简介：肌肉损害在运动仍然是最普通的损害之一，还尽管有这，几乎没有怎么有效地描述或决定特定的肌肉损害的预后到也上的很少一致。肌肉分类的众多的途径并且药分级在最后世纪被使用了，但是在最后十年，历史性的途径的限制被认出了。作为后果，在过去的10年里，临床的研究组开始询问了历史性的途径并且重新考虑肌肉损害被分类并且描述的方法。用一条记事途径，这张手稿描述几次最近的尝试分类并且分级肌肉损害并且加亮每个系统的相对力量和软弱。当时每新分类和分级的系统有力量，几乎在那里不在全面的一个系统和基于的证据上仍然是很少一致。很少在分级的系统以内的当前识别的特征有关联到精确地决定预后。

简介：Objective:Tomeasuremovementsofmarkersovertheprimarysiteandassociatedmimicmusclesincertainfacialexpressions,forevaluatingfacialparesisandsynkinesis.Methods:Participantsincluded22normalsubjectsaged45e66years.Maximumshift(Smax)andvelocity(Vmax)weremeasuredusingacustom-designed3-Ddynamicquantitativeanalysissystemoffacialmotion(3-DASFM)basedonmotioncapturetechnology.Measuresweretakenfromperi-oralmusclesduringforcefulbrowraisingandtighteyeclosure,andfrommusclesaroundtheeyeduringgrinning,right/left/bilateralmouthcornerraisingandsmiling.Results:1)Duringforcefulbrowraising,Smaxwas3.65e4.46mmformarkersoverperioralmuscles,withthemarkeroverthenasolabialfoldshowingaVmaxgreaterthanothers(60.60mm/sonleftand62.70mm/sonright).2)Intighteyeclosure,Smaxofperioralmusclemarkerswas1.58e1.92mm,withVmaxbeing11.40e14.76mm/s.3)Ingrinning,thelargesteyemusclemarkerSmaxwasseenatthelowerlid(3.93mmonleftand4.15mmonright)andthesmallestattheinnercanthus(1.59mmonleftand1.53mmonright),withthelargestVmaxseenattheupperlidandsmallestalsoattheinnercanthus(11.71mm/sonleftand11.09mm/sonright).4)Insmiling,thelargestnon-oralSmaxandVmaxwereseenattheupperlid(3.05mmand36.14mm/sonleftand2.53mmand28.90mm/sonright)andthesmallestalsoattheinnercanthus(0.69mmand7.22mm/sonleftand0.77mmand7.80mm/sonright).5)Inrightmouthcornerraising,SmaxandVmaxatlateralandmedialcanthusandatlowerlidweregreateronrightthanleft,whilethoseatupperlidandbrowwereslightlygreateronleftthanright.6)Inleftmouthcornerraising,SmaxandVmaxatlateralcanthusandupperandlowerlidsweregreateronleftthanright.Conclusions:Therearenoabsoluteimmobilepointsonthefacewhenmakingfacialexpressions.Inadditiontotheprimarymovementsite,thereareassociatedmovementsatotherpointsonthefacewithconsistent

简介：Background:Chronicinflammationisanimportantetiologicmechanismformuscleatrophy.Oat-derivedphytochemicalavenanthramides(AVAs)havebeenshowntosuppressinflammatoryresponsesinhumanclinicalstudiesandinseveralcelllinesinvitro,buttheirroleinskeletalmuscleisunclear.TheaimofthisstudywastoinvestigatewhetherAVAtreatmentcanpreventtumornecrosisfactor(TNF)-α-inducedmusclefiberatrophyinC2C12cells.Methods:Wetreated70%confluentcellsfor24hwithAVA.Then,TNF-αwasaddedtocell-culturedmedium.Subsequently,cellswereharvestedatdifferenttimepoints.Thecellswereexaminedusingvariousbiochemicaltechniquesformeasuringprotein,messengerRNAlevels,nuclearbindingactivity,andviability.Fluorescencemicroscopewasusedforanalysisofthemyotubemorphology.Results:CellstreatedwithTNF-asignificantlyincreasednuclearfactorkBactivation,indicatedbyamarkeddecreaseofIkB(p<0.05)anda6.6-foldincreaseinp65-DNAbinding(p<0.01);however,30mmolofAVA-A,-B,and-Ctreatmentreducedthebindingby33%,18%,and19%(p<0.01),respectively,comparedwithcellstreatedwithTNF-awithoutAVA.Theinterleukin-6levelincreasedby2.5fold(p<0.01)withTNF-α,butdecreasedby24%,32%,and28%(p<0.01),respectively,withAVA-A,-B,and-C.Theinterleukin-1blevelalsoshoweda47%increasewithTNF-a(p<0.01),whereasthisincrementwasabolishedinallAVA-treatedcells.Reactiveoxygenspeciesproductionwas1.3-foldhigherintheTNF-α-treatedgroup(p<0.01)butnotintheTNF-α+AVAsgroups.MessengerRNAlevelsofmuscle-specificE3ubiquitinligaseatrogin-1increased23%inTNF-αvs.control(p<0.05)butwasdecreasedby46%,34%,and53%(p<0.01),respectively,withtreatmentofAVA-A,-B,and-C.Moreover,TNF-αtreatmentincreasedthemuscleRINGfinger1messengerRNAlevelby76%(p<0.01);thischangewasabolishedbyAVAs.CellstreatedwithTNF-ademonstratedareducedproliferationcomparedwithcontrolcells(p<0.01)

简介：Hamstringmusclestraininjuryisoneofthemostcommoninjuriesinsportsinvolvingsprintingandkicking.Hamstringmusclestraininjuriesoccuratahighrateandhaveahighre-injuryrate,whichresultsinlossoftrainingandcompetitiontime,whichhasasignificantimpactonthequalityoflifeoftheinjuredathletes.~1Preventingandrehabilitatinghamstringmusclestraininjuryisanimportanttaskforcliniciansandscientistsinsportsmedicine.Understandingthemechanismsunderlyinghamstringinjuryiscriticalfordevelopingappropriatestrategiestopreventandrehabilitatehamstringinjuries.Understandingthegeneral

简介：在这研究，我们调查了白果树biloba摘录(GBE)和phosphodiesterase类型的联合的效果5(PDE-5)阴茎海绵体和下士的钾隧道活动的肌肉发达的音调上的禁止者弄平肌肉房间。从雄的新西兰白兔子的阴茎海绵体的脱衣为等轴的紧张研究在器官洗澡被装。在有1×的收缩以后；10−5 moll−1新肾上素，GBE(0.01-1 ；mgml−1)和mirodenafil(0.01-100 ；nmoll−1)一起被增加进机关洗澡。在electrophysiological研究，整个房间的水流被常规补丁夹钳技术在人的阴茎海绵体的有教养的光滑的肌肉房间记录。阴茎海绵体以一种剂量依赖者方式响应GBE被放松(从0.64%；±；8.35%；在0.01 ；mgml−1到52.28%；±；11.42%；在1 ；mgml−1)。在有0.03 的预告的处理以后；GBE的mgml−1，mirodenafil的弛缓的效果根本被增加集中。在tetraethylammonium(茶)以后(1 ；mmoll−1)管理，增加的效果被禁止(P<；0.01)。GBE的细胞外的管理增加了在一个剂量依赖者的外面的水流塑造的整个房间的K+。外面的水流的增加被1 禁止；mmoll−1茶。这些结果建议GBE能甚至在最低限度地有效的剂量增加mirodenafil的弛缓的力量。通过钾隧道的K+流动可能是涉及这synergistic松驰的机制之一。

简介：AbstractBackground:The effectiveness of bronchial thermoplasty (BT) has been reported in patients with severe asthma. This study compared the effects of BT and cryoballoon ablation (CBA) therapy on the airway smooth muscle (ASM).Methods:Eight healthy male beagle dogs were included in this experiment. In the preliminary experiment, one dog received BT treatment for both lower lobe bronchus, another dog received CBA treatment for 7 s on the upper and lower lobe of right bronchus, and 30 s on the left upper and lower lobe. The treatments were performed twice at an interval of 1 month. In subsequent experiments, the right lower lobe bronchus was treated with BT, and the left lower lobe bronchus was treated with CBA. The effects of treatment were observed after 1 (n = 3) month and 6 months (n = 3). Hematoxylin-eosin staining, Masson trichrome staining, and immunohistochemical staining were used to compare the effects of BT and CBA therapy on the ASM thickness, collagen fibers synthesis, and M3 receptor expression after treatment. One-way analysis of variance with Dunnett post hoc test was used to analyze the differences among groups.Results:In the preliminary experiment, the ASM ablation effect of 30-s CBA was equivalent to that of 7-s CBA (ASM thickness: 30.52 ± 7.75 μm vs. 17.57 ± 15.20 μm, P = 0.128), but the bronchial mucociliary epithelium did not recover, and large numbers of inflammatory cells had infiltrated the mucosal epithelium at 1-month post-CBA with 30-s freezing. Therefore, we chose 7 s as the CBA treatment time in our follow-up experiments. Compared with the control group (35.81 ± 11.02 μm), BT group and CBA group (13.41 ± 4.40 μm and 4.81 ± 4.44 μm, respectively) had significantly decreased ASM thickness after 1 month (P < 0.001). Furthermore, the ASM thickness was significantly lower in the 1-month post-CBA group than in the 1-month post-BT group (P = 0.015). There was no significant difference in ASM thickness between the BT and CBA groups after six months (9.92 ± 4.42 μm vs. 7.41 ± 7.20 μm, P = 0.540). Compared with the control group (0.161 ± 0.013), the average optical density of the ASM M3 receptor was significantly decreased in 6-month post-BT, 1-month post-CBA, and 6-month post-CBA groups (0.070 ± 0.022, 0.072 ± 0.012, 0.074 ± 0.008, respectively; all P < 0.001). There was no significant difference in the average optical density of ASM M3 receptor between the BT and CBA therapy groups after six months (P = 0.613).Conclusions:CBA therapy effectively ablates the ASM, and its ablation effect is equivalent to that of BT with a shorter onset time. A neural mechanism is involved in both BT and CBA therapy.

简介：IntheirrecentpapersintheJournalofSportandHealthScienceonhamstringinjuriesinsprinting,~(1,2)andtheircorrespondingcommentariesoneachother'sresearch,3,4Yuetal.andLiuetal.proposeddifferentviewsofthemechanismsofmuscleinjuriesingeneral,andhamstringinjuriesinsprintingspecifically.WhileYuetal.~(1,3)arguedthatmuscleinjuriesareprimarily,ifnotexclusively,causedbymusclestrainmagnitudeineccentriccontractions,andthushamstringinjuriesoccurprimarilyat

简介：Background:Forefootstrike(FFS)andrearfootstrike(RFS)runnersdifferintheirkinematics,forceloadingrates,andjointloadingpatterns,butthetimingoftheirmuscleactivationislessclear.Methods:Fortyrecreationalandhighlytrainedrunnersranatfourspeedsbarefootandshodonamotorizedtreadmill.'Barefoot'runnersworethin,five-toedsocksandshodrunnersworeneutralrunningshoes.Subjectswereinstructedtoruncomfortablyateachspeedwithnoinstructionsaboutfootstrikepatterns.Results:ElevenrunnerslandedwithanFFSwhenbarefootandshodandelevenrunnerslandedwithanRFSwhenbarefootandshod.The18remainingrunnersshiftedfromanFFSwhenbarefoottoanRFSwhenshod(shifters).Shodshiftersranwithalowerstridefrequencyandgreaterstridelengththanallotherrunners.AllFFSrunnerslandedwithmoreplantarflexedanklesandmoreverticallowerlegsatthebeginningofstancecomparedtoRFSrunners.FFSrunnersactivatedtheirplantarflexormuscles11%earlierand10%longerthanRFSrunners.Conclusion:Thisearlierandlongerrelativeactivationoftheplantarrlexorslikelyenhancesthecapacityforthepassivestructuresofthefootandankletostoreelasticenergy,andmayalsoenhancetheperformanceoftheactivemusclebyincreasingthestorageofelasticstrainenergyinthecross-bridaesandactivatedthin.

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简介：Hamstringmusclestraininjuryisthemostcommonandprevalentinjuryinsportsinvolvinghigh-speedrunning,suchasAmericanfootball,Australianfootball,Englishrugby,soccer,trackandfield,andcricket.1Hamstringmusclestraininjuryalsohasahighrecurrencerateofupto48%.2Theaveragepracticeandgametimelossduetohamstringinjuryisbetween17and60days,contingentonthegradeofinjury.2Severehamstringmusclestraininjuries,andassociatedrecurrentinju-

简介：对骨胳的肌肉新生的成长兴趣在损伤，以及几个肌肉发达的退化病理以后为肌肉损害与新治疗学的策略的开始被联系，包括营养障碍，肌肉发达的萎缩，和极度瘦弱。集中于细胞外的因素的能力支持myogenesis的研究因此是高度有希望的。我们现在报导那一个导出adipocyte的因素，球状的adiponectin(荡者)，能导致肌肉基因表示和房间区别。除它在肌肉调整几新陈代谢的功能的著名能力以外，包括葡萄糖举起和消费和丰满的酸分解代谢，荡者能堵住myoblasts的房间周期入口，到导致象肌浆球蛋白那样的特定的骨胳的肌肉标记的表示重链或caveolin-3，象一样挑起房间熔化进multinucleatedsyncytia并且，最后肌肉纤维形成。荡者通过p38，Akt和5鈥?的氧化还原作用依赖者激活施加它的pro-differentiative活动激活安培的蛋白质kinase小径。有趣地，区分myoblasts是为adiponectin的autocrine，并且到氧化应力的支持inflammatory背景或暴露的mimicking强烈从区分房间增加荷尔蒙的生产。这些数据建议adiponectin的一个新奇函数，直接协调myogenic区别程序并且在骨胳的myogenesis期间服务一个autocrine函数。