简介:年龄相关性黄斑变性(age-relatedmaculardegeneration,AMD)是一个多因素多基因多过程介导的慢性退行性病变。亚临床炎症是组织结构对损害性应激或者异常功能做出的介于炎症和正常之间的状态,其生理功能是保存正常功能和稳态。本文旨在通过亚临床炎症为中心,探讨AMD各种致病机制的内在联系。在个体遗传基因不同易感性为基础上,危险因素直接或者间接通过氧自由基累积影响基因,导致视网膜神经层-色素表皮细胞-Bruch膜-脉络膜毛细血管(neuroretina-pigmentepithelium-Bruch'smembrane-choriocapillaris,NR-RPE-MB-CC)长期处于一种亚临床炎症状态,最终导致视网膜细胞凋亡或者脉络膜血管增生。
简介:目的利用Micro-CT扫描数据建立中耳听骨链三维有限元模型。方法用Micro—CT扫描成人颞骨标本,将获得的图像数据通过MicroView、Mimics等软件进行三维重建。再将模型转入其有限元分析(finiteelementanalysis,FEA)模块的Remesh环境中进行调整、细化及面网格优化,通过SOLIDEWORK软件转换为实体网格。结果初步形成的三维几何模型可较清晰地辨别鼓室腔、听小骨和内耳系统,但部分图像不同程度存在噪点。最终形成了FEA软件可识别的成人中耳听骨链三维有限元网格模型,网格划分后的听骨链有限元模型中,完整听骨链的节点数降低,由原来包括805个不合理节点在内的12498个节点降低到2050个,在此基础上建立的有限元模型共1350个8节点四面体单元。结论结合Micro—CT技术及Mimics软件的三维建模方法可以快速获得较精确的听骨链三维数据,是建立听骨链三维有限元模型的有效途径。(中国眼耳鼻喉科杂志,2009.9.83。85)
简介:目的探讨白内障防盲手术中透明质酸酶和亚甲蓝染色对麻醉效果和连续环形撕囊成功率及对手术效果的影响。方法100例(100眼)白色白内障随机分为2组进行前瞻性研究。球周麻醉中加入透明质酸酶及改良亚甲蓝前囊膜染色组53例,对照组(球周麻醉中不加入透明质酸酶和前囊不染色)47例。球周麻醉后,行现代白内障囊外摘除及人晶状体植入术。比较环形撕囊成功率、术中并发症、术后反应情况、视力、眼压。结果2组术中撕囊成功率及人工晶状体体囊袋内植入率均有差别,与对照组相比差异有统计学意义;2组术后反应情况、视力、眼压无统计学意义。结论球周麻醉中加入透明质酸酶及改良亚甲监染色明显提高连续环形撕囊成功率。降低白内障手术并发症,无明显副作用,且廉价易得,适合在防盲白内障手术中推广。
简介:AIM:Toexaminetheexpressionofsurvivinandvascularendothelialgrowthfactor(VEGF)duringthedevelopmentofretinalneovascularization(NV)inamousemodel.·METHODS:Awell-characterizedmurinemodelofretinalNVwasusedtostudytheexpressionofsurvivinandVEGF.NVoftheretinawasinducedinmicebyexposureto75%O2frompostnataldayP7toP12,followedbyreturntoroomairfromP12toP17.ExpressionofsurvivinandVEGFproteinwasanalyzedbyImmunohistochemistry.Inaddition,mousemodelofproliferativeretinopathywasanalyzedbyretinalfluoresceinangiographyandquantificationanalysis.·RESULTS:Thenormalmicehadbothsuperfiekalanddeepvascularlayersthatextendedfromtheopticnervetotheperiphery.Inintraocularpressure(IOP)micewerecharacterizedbyrepresentatypicalpatternofpathologicalretinalNV.Therearelessorlittlenucleiofnewvesselsvascularendothelialcellbreakingthroughtheinnerretinalthaninretinopathyofprematurity(ROP)mice,largeclustersofbloodvesselswereadherenttotheinternallimitingmembrane(ILM)(0.27±0.20vs23.38±1.027,t=9.454,P<0.001).DuringtheangiogenicperiodfromP13toP17,survivinandVEGFproteinexpressionincreasedinexperimentalretinascomparedwithcontrolsamples(2.56±0.46vs3.34±0.40,t=17.43,P<0.01:2.18±0.75vs4.34±0.25,t=19.61,P<0.01).ProteinlevelsofVEGFandsurvivnhassignificantlypositivecorrelation(P<0.05,r=0.411).·CONCLUSION:CorrelationwasmadeattheproteinlevelsofsurvivinexpressioncomparedwiththatofVEGFinamurinemodelofretinalNV,whichsuggestsatemporalroleforsurvivinandVEGFinnewvesselformationinresponsetohypoxicstimulation.
简介:AIM:Toassesstheeffectivenessofimmunosuppressantsintheprophylaxisofcornealallograftrejectionafterhigh-riskkeratoplastyandnormal-riskkeratoplasty.METHODS:WesearchedtheCochraneCentralRegisterofControlledTrials(CENTRAL),MEDLINE,EMBASE,CNKI,VIPandreferencelistsofarticles.Dateofmostrecentsearch:18June,2011.Allrandomisedcontrolledtrials(RCTs)assessingtheuseofimmunosupressantsinthepreventionofgraftrejection,irrespectiveofpublicationlanguage.Twoauthorsassessedtrialqualityandextracteddataindependently.Onlydichotomousoutcomes(cleargraftsurvival,ratioofimmunereactionsandsideeffects)wereavailableandwereexpressedasrelativerisk(RR)and95%confidenceintervals(CI).RESULTS:Sevenstudieswereincludedinthisreview.Inthecomparingofmycophenolatemofetil(MMF)withplacebo,theresultsshowedMMFcouldsignificantlyreduceimmunereactionscomparedwithplacebo(RR1.0895%Cl0.95to1.21),butnoeffectoncleargraftsurvival(RR1.1195%Cl0.90to1.35).Incleargraftsurvivalandimmunereactions,MMFandcyclosporineA(CsA)showedsimilareffect(RR1.1195%Cl0.90to1.35,andRR1.48,95%Cl0.56to3.93,respectively).Tacrolimus(FK506)andsteroidshowedsimilareffectsoncleargraftsurvivalandimmunereactions(RR0.32,95%CI0.02to6.21,andRR1.00,95%CI0.88to1.14,respectively).Nodrugrelativesideeffecthasbeenfound.CONCLUSION:MMFmayreduceimmunereactionsinbothnormal-riskandhigh-riskrejectionofpenetratingkeratoplasty.CsAandFK506showedsimilareffectsasMMF.However,duetothelackoflargeclinicaltrials,theevidenceremainweak,thequalityofevidenceswereratedasverylowtomoderate.Large,properlyrandomised,placebo-controlled,doublemaskedtrialsareneededtoevaluatetheeffectofimmunosuppressants.