【作者】 吴训；

【导师】 周诺；

【作者基本信息】 广西医科大学 ， 口腔临床， 2008， 硕士

【摘要】 目的:通过测定炎性细胞因子白细胞介素-6(IL-6)和环氧合酶-2(COX-2)在犬下颌骨牵张成骨过程中的表达,并将之与直接延长术组的进行比较分析,探讨其与新骨形成的关系,以进一步研究牵张成骨机制。方法:28只狗随机分为牵张成骨组和直接延长组各12只,以及正常对照4只,牵张组于双侧第一与第二磨牙之间将下颌骨截断,并装上牵张器将下颌骨固定,于术后第8天开始牵张,牵张频速率1mm/次/天,连续牵张10天后固定,将牵张器保留原处作为固定器,分别于牵张第6天、固定2周、固定8周各处死4只动物,切取双侧牵开区骨组织待测;而直接延长组则在相同的部位以相同的术式完成下颌骨截断术后直接拉开10mm后行钛板内固定,与牵张组的相应时期分别处死相同数量的动物,切取双侧拉开区组织待测;正常对照组,手术直接于第一及第二磨牙区切取相应骨组织待测。实验动物分别于牵张完毕、固定2周、4周、8周对牵开区拍X线片检查。所有标本处理后均作常规HE染色和IL-6、COX-2免疫组化染色分析。结果:免疫组化表明IL-6、COX-2主要阳性染色于牵张区的间充质细胞、成骨细胞、成纤维细胞、破骨细胞、软骨细胞以及新骨基质等。经灰度值分析发现,无论是在牵张成骨组还是在直接延长组,IL-6、COX-2在牵张第6天时表达水平最高,随着骨组织的不断成熟,固定2周和固定8周时其表达逐渐下降。在牵张6天和牵张固定2周时,牵张组IL-6、COX-2的表达较直接延长组增高,二者存在统计学差异(p＜0.05);而在牵张固定8周时,IL-6、COX-2在牵张组和直接延长组中的表达灰度值增大,即表达量下降,但是牵张组的表达仍较直接延长组的要高,二者存在统计学差异(p＜0.05)。IL-6和COX-2在正常对照组中几乎无表达。结论:IL-6和COX-2可能参与了促进下颌骨牵张成骨和骨缺损修复新骨形成的过程;同时二者作为组织损伤和炎症的敏感标志物,提示炎症在牵张成骨发生发展中可能起着重要作用。更多还原

【Abstract】 Objective:To approach the scientific mechanism of bone regeneration in distraction osteogenesis,we had examined the expression level of interleukin-6(IL-6)and cyclooxygenase-2(COX-2)during canine mandible distraction osteogenesis.Meanwhile we had compared the expression level of both cell factors’ between in DO group and in acute lengthening group.Methods:We selected 28 adult dogs,which had been ramdomly divided to three groups:control group(n=4),acute lengthening group(n=12)and DO group(n=12).In DO group the dogs were underwent bilateral mandibular osteotomy between the first and second molars,and two custom-made distraction devices were fixed in the both two osteotomy regions.After a latency period of 7 days post-osteotomy,the distraction devices had beenactivated at a rate of 1mm per day and for 10 days.In acute lengthening group dogs were as the DO group as underwent bilateral mandibular osteotomy in the same region and acutely lengthened to 10mm and fixed by titanium plates.In both groups, four dogs were respectively sacrificed on day 6th of distraction period,on week 2nd and 8th of consolidation period.Callus of the both groups and that located the same region of control group were harvested.The spatial and temporal expression patterns of IL-6 and COX-2 were studied using immunohistochemistry.The X-ray examination was taken respectively on day 1st,week 2nd、4th and 8th after completion of distraction.Results:X-ray found that the density of new bone in both DO group and acutely lengthening group was enhanced gradually as time of fixation elapsed. But the new bone density in DO was higher than acute lengthening group at the same time.Using immunohistochemistry IL-6&COX-2 were detected in both DO group and acute lengthening group and expressed strongly in the regenerated callus,none of which was detected in control group.The IL-6&COX-2 were expressed in osteoblast cells,osteoclast cells,fibroblast cells,cartilage cell and the regenerated bone matrix.The expression of IL-6&COX-2 in DO group showed higher than that in acute lengthening group.Meanwhile the expression of IL-6&COX-2 of the two experimental group showed higher than that in control group,and finally gradually decreased with the time of consolidation elapsing.Conclusion:IL-6&COX-2 might participate the process of distraction osteogenesis and bone defect healing and accelerate the new bone forming.Both IL-6&COX-2 were the sensitive markers of tissue damage and inflammation and detected in DO.So it was suggested that micro- trauma might play an important role to activate the DO procedure.更多还原