Rush钉矫治成骨不全儿童股骨畸形的疗效观察

目的探讨股骨多段截骨髓内钉固定矫治儿童成骨不全症所致股骨畸形的疗效,分析术后并发症的防治。方法 2007年1月至2013年12月,我院共收治成骨不全所致股骨畸形患儿28例,包括39根畸形股骨。年龄3岁7个月至14岁5个月,平均8岁4个月。术中将弯曲股骨行多段截骨矫形及髓内钉固定,平均截骨1.9(1~3)处,随机分为弹性针组与Rush钉组,其中20根股骨使用弹性髓内钉,19根股骨使用Rush钉。结果随访1年3个月至5年7个月,平均3年8个月。随访后期按Sanders评分标准评定髋关节功能:弹性针组优11例,良2例,中7例,差0例;Rush钉组优16例,良2例,中1例,差0例。结论多段截骨矫形后髓内钉内固定治疗儿童成骨不全所致股骨畸形,能有效矫正股骨弯曲畸形,改善下肢外观及力线关系,防止再骨折,提高患儿生活质量,效果明确。Rush髓内钉内固定效果满意,术后再骨折概率小,股骨不易再次弯曲变形,值得临床推广。     

骨皮质切开辅助正畸研究进展

近年研究发现骨皮质切开术可以有效加速正畸治疗,该技术以局部加速修复现象为理论基础发展而来,术式在其发展的百年间几经改良。在骨皮质切开的基础上发展出牙周快速成骨正畸,使用这种技术可使正畸治疗时间减少到传统正畸治疗时间的1/3到1/4,增强牙周组织支持,增加骨覆盖,减少牙根吸收,降低复发率。该文综合概述了骨皮质切开发展史,骨皮质切开后牙齿移动的机理与传统正畸的不同之处,以及相关临床、实验研究。     

固定义齿联合活动义齿修复牙本质发育不全患者1例

牙本质发育不全（DI）是一种遗传性疾病,患者牙本质发生病变,尤其多发于恒牙。患牙临床表现为棕黄色、釉质缺失、过度磨耗等,修复治疗这类牙具有极高的挑战性。本文报道1例用固定义齿联合活动义齿修复牙本质发育不全的患者。     

PI3K／Akt信号通路在骨髓间充质干细胞增殖及成骨分化调控中的作用

目的：研究PI3K/Akt信号通路抑制剂LY294002对骨髓间充质干细胞（mesenchymal stem cells,MSCs）增殖及分化的影响。方法采用贴壁法体外分离人骨髓间充质干细胞（hMSCs）,加入PI3K抑制剂LY294002（1、10μmol/L）,应用MTT法测定细胞增殖,常规成骨诱导分化培养3或7d,采用碱性磷酸酶（ALP）染色观察成骨分化水平,化学比色法测定ALP活性,茜素红染色后观察矿化钙结节数量并定量分析,Westernblot检测磷酸化Akt蛋白表达,应用Realtime-PCR检测各组细胞BMP2、Runx2、OPN及Osterix等成骨分化标记物的基因表达水平。结果从24至72h,LY294002对hMSCs增殖均产生显著抑制,随时间推延,可见抑制增殖效果增强（P＜0.05）。ALP染色和定量测定提示10μmol/L的ALP活性最强,在不同时间显著高于对照组和1μmol/L组（P＜0.05）。成骨诱导培养3和7d,1、10μmol/L组矿化量都显著高于对照组（P＜0.05）。10μmol/L组矿化量在成骨诱导7d也显著高于1μmol/L组（P＜0.05）。Westernblot检测结果证实成骨诱导可激活Akt磷酸化蛋白表达,但LY294002可抑制该蛋白磷酸化。成骨诱导分化7d,1、10μmol/L均明显促进BMP2、Runx2、OPN、Osterix4种基因mRNA表达（均P＜0.05）。结论PI3K/Akt信号通路参与hMSCs增殖和分化过程。成骨分化伴随下游Akt蛋白表达。PI3K抑制剂可抑制hMSCs增殖,但同时促进其向成骨分化和矿化。     

microRNA调控间充质干细胞成骨分化的研究进展

间充质干细胞是一类体内广泛存在的多能干细胞,具有多向分化潜能,为多种组织器官提供保护及损伤修复。近年来,间充质干细胞向成骨细胞诱导分化用于治疗骨代谢等相关性疾病已成为热点。microRNA（miRNA）作为生物体内重要的小分子非编码RNA,通过转录后调控影响基因表达,参与各种生命过程。研究显示,多种不同的miRNA在间充质干细胞向成骨分化过程中起着核心调节作用。本文结合相关文献,对miRNA调控间充质干细胞成骨分化的作用及机制归纳总结,以帮助全面了解靶向miRNA治疗骨代谢性相关疾病的潜能。     

Does enamelin have pleiotropic effects on organs other than the teeth? Lessons from a phenotyping screen of two enamelin‐mutant mouse lines

We analyzed two mutant mouse lines, ATE1 and ATE2, that carry point mutations in the enamelin gene which result in premature stop codons in exon 8 and exon 7, respectively. Both mutant lines show amelogenesis imperfecta. To establish the effect of mutations within the enamelin gene on different organs, we performed a systematic, standardized phenotypic analysis of both mutant lines in the German Mouse Clinic. In addition to the initially characterized tooth phenotype that is present in both mutant lines, we detected effects of enamelin mutations on bone and energy metabolism, as well as on clinical chemical and hematological parameters. These data raise the hypothesis that enamelin defects have pleiotropic effects on organs other than the teeth.     

Two novel distinct COL1A2 mutations highlight the complexity of genotype–phenotype correlations in osteogenesis imperfecta and related connective tissue disorders

Osteogenesis imperfecta is a heritable connective tissue disorder characterized by variable symptoms including predisposition to fractures. Despite the identification of numerous mutations, a reliable genotype–phenotype correlation has remained notoriously difficult. We now describe two patients with osteogenesis imperfecta and novel, so far undescribed mutations in the COL1A2 gene, further highlighting this complexity. A 3-year-old patient presented with features reminiscent of a connective tissue disorder, with joint hypermobility, Wormian bones, streaky lucencies in the long bones and relative macrocephaly. The patient carried a heterozygous c.1316G > A (p.Gly439Asp) mutation in the COL1A2 gene located in a triple-helix region, in which glycine substitutions have been assumed to cause perinatal lethal OI (Sillence type II). A second family with type I osteogenesis imperfecta carried a heterozygous nonsense mutation c.4060C > T (p.Gln1354X) within the last exon of COL1A2. Whereas other heterozygous nonsense mutations in COL1A2 do not lead to a phenotype, in this case the mRNA is presumed to escape nonsense-mediated decay. Therefore the predicted COL1A2 propeptide lacks the last 13 C-terminal amino acids, suggesting that the OI phenotype results from decelerated assembly and overmodification of the collagen triple helix. The presented COL1A2 mutations exemplify the complexity of COL1A2 genotype–phenotype correlation in genetic counselling in OI.