Repair of cartilaginous fractures during chick limb development.

The embryonic chick wing has been used extensively in experimental analyses of the mechanisms involved in limb development. This study employs the embryonic wing in an examination of the possible origin of congenital pseudoarthrosis, a poorly understood limb disorder. To this end, chick radii were fractured in the middiaphysis prior to the onset of osteogenesis (6.5-7 days of incubation). The subsequent development of the fractured elements was examined using both whole mount preparations and histology. Callus cartilage did not form around any of the fractures. Nonetheless, the majority (29 of 33 specimens) of fractures united during primary osteogenesis (within 24-36 h of the operation), with bone formation occurring both across the fracture site and also over the cut ends of the cartilage. In addition, bones that exhibited a configuration similar to that described as giving rise to a type II congenital pseudoarthrotic condition were obtained. Typically, these bones showed an "hourglass" constriction midshaft and anterior bowing. These results suggest that the embryonic chick limb may serve as a useful experimental model system for the investigation of this congenital limb disorder.     

The effect of electric fields on osteoporosis of disuse

Summary An experiment originally done by McElhaney et al. was repeated to obtain additional information about the effects of electrical fields on osteoporosis of disuse. The right femurs of 35 male rats were immobilized in plaster casts. Sixteen rats were treated with transcutaneous electrical fields of 30 Hz and 100 V/cm for periods of 2 or 8 h a day. While the right femurs of the untreated rats were found to be atrophic with respect to the opposite limb, in the treated rats the immobilized femur was made larger than the opposite bone. Longer daily treatments exaggerated this effect. The tumors found in the previous study were not seen in our experiments. Other similarities and differences in the 2 studies are discussed.     

Stimulation of bone formation in vivo by phosphate supplementation

The effect of phosphate supplementation on bone remodeling was assessed in six mature, healthy beagle dogs. The phosphate supplement was given in divided doses orally, daily for 12 weeks in the form of a neutral potassium phosphate preparation. The dose averaged 108 mg P/kg per day, which is double the normal canine phosphorus intake. Bone remodeling was assessed by measurement, at sacrifice, of areas of cortical bone containing different colorcoded tetracyclines which had been continuously administered during 12-week control and treatment periods; remodeling was assessed kinetically during the control and treatment periods by replicate studies employing⁴⁷Ca intravenously.Both techniques demonstrated that the principal effect of phosphate supplementation was a significant stimulation of bone formation. Within cortical bone, formation was doubled, from an average of 2.7% to 5.3% per year. The major location of new bone deposits was endosteal. Whole skeletal mineral accretion, measured kinetically, increased 45% above an average control value of 0.154 g/day. These studies suggest that, in the adult dog, normal plasma phosphate levels are suboptimal for new bone formation.Even with this short duration of administration, phosphate produced microscopic calcification of the renal parenchyma. However, there was no biochemical evidence of renal functional impairment.     

应用内置钛镍记忆合金牵张器在下颌骨牵张成骨的初步研究

目的　探索利用钛镍记忆合金牵张成骨增高下颌牙槽嵴和修复下颌骨节段性缺损的可行性。方法　 2 0只成年杂种犬分为 5组 ,Ⅰ组和Ⅱ组进行牵引成骨增高下颌骨牙槽嵴 ,Ⅲ组和Ⅳ组进行牵引成骨修复下颌骨缺损 ,Ⅴ组作为对照。牵引成骨用自行设计制作的内置型钛镍合金牵张器 ,在牵张手术前及术后 1、5、13周拍X线片 ,分别在牵张完成后 1、3个月处死动物 ,进行组织学研究。结果　钛镍牵张器显示了良好的组织相容性 ,自动完成牵引骨形成 ,牵张器安置完成后骨块即开始移动 ,X线片可见牵张完成后 1个月牵张区骨密度增高 ,有新骨生成 ;3个月时新生骨密度与周围骨接近 ,有效地增加了牙槽嵴的高度和初步修复了下颌骨的节段性缺损。组织学观察可见牵张区新骨形成良好。结论　内置自加载钛镍记忆合金牵张器自动牵引成骨是一种具有良好应用前景的简便实用的牵引成骨技术。     

兔下颌骨牵张成骨组织中c—los和OPG及OPGL的表达

目的：探讨在机械张力作用下骨细胞将生物力学信号转变为生物学效应的作用机理。方法：建立兔下颌骨牵张成骨模型，用免疫组化方法检测牵张中期（牵张第4天）、牵张末期（牵张第8天）与固定期2周、4周、6周的牵张区新生骨组织中c—los、骨保护素（OPG）、破骨细胞分化因子（OPGL）的分布和表达。结果：在牵张中期和末期c—los的表达为强阳性，明显强于固定期2周、4周、6周的组织。牵张中、末期和固定期2周组织OPG的表达为强阳性，在固定期4周、6周组织中逐渐减弱。OPGL仅在固定期6周组织中有较弱表达，其余各时间点均无明显阳性表达。结论：在下颌骨牵张新骨形成改建过程中，c—los与机械力刺激关系密切，OPG能促进新骨形成，而OPGL则与骨改建有关。     

颌骨畸形伴阻塞性睡眠呼吸暂停低通气综合征的牵引成骨治疗

目的　探讨牵引成骨技术在颌骨畸形继发阻塞性睡眠呼吸暂停低通气综合征(obstructivesleepapnea hypopneasyndrome,OSAHS)治疗中应用的效果。方法　收集自 1 997年 1 0月～2 0 0 2年 9月共 46例颌骨畸形伴OSAHS少年儿童 ,患者睡眠呼吸障碍经夜间多导睡眠监测证实。年龄从 4～ 1 8岁 ,平均年龄 1 1 4岁 ,其中颞下颌关节强直伴小下颌畸形 32例 ;小下颌畸形患者 9例 ;第一、二鳃弓综合征 2例 ;Crouzon综合征 3例。患者术前常规拍照、摄头颅定位侧位片 ,全景片。每位患者根据畸形情况 ,采取单侧或双侧牵引成骨治疗 ,根据侧位片预测 ,一般牵引到略微反覆盖为准。牵引幅度为 5～ 35mm ,平均牵引幅度 1 8 34mm。比较患者术前后颅颌面形态、呼吸道测量分析、多导睡眠监测结果评价治疗效果。结果　患者术后颌骨畸形明显改善 ,头影测量分析提示上呼吸道狭窄得以显著缓解 ,最小后气道径 ( x±s)由 (5 48± 2 76)mm增加到 (9 97± 2 0 5)mm ,睡眠呼吸暂停低通气指数 (apnea hypopneaindex,AHI, x±s)从术前 (66 31± 1 7 1 5)次 /s降低到 (3 1 6± 1 70 )次 /s,以上结果统计分析表明差异具有非常显著性 (P <0 0 0 1 )。结论　牵引成骨治疗颌骨畸形继发OSAHS患者具有很好的疗效     

骨形成耦联血管生成中HIF-1α作用

骨的发育和再生中血管生成和骨形成是紧密相连的耦联关系。低氧/缺氧诱导因子-1α(hypoxia-inducible factor-1alpha,HIF-1α)在骨骼发育中扮演了关键的角色。成骨细胞HIF-1α信号系统介导的骨形成不是成骨细胞独立自主的活动,而是与骨骼血管生成所依赖的血管内皮生长因子信号系统相耦联的。本文就HIF系统及其参与骨骼发育过程方面作一综述。     

他克莫司诱导的骨髓间充质干细胞成骨细胞分化和体内骨形成

目的研究免疫抑制剂他克莫司（FKS06）对大鼠骨髓来源的间充质干细胞（MSC）的成骨细胞分化诱导,及对MSCs结合多孔β三磷酸钙（β—TCP）的体内成骨作用。方法原代MSCs按实验目的随机分组。对照组生长培养液中加入L-抗坏血酸-2-磷酸（AsAp）和β-甘油磷酸（β—GP）;FKS06处理组在对照组基础上加入50nmol／LFK506。实验分成体外体内两部分相继进行。体外实验细胞分别于培养第4、8、12、16天时行碱性磷酸酶（APase）活性,钙含量,扫描电镜和骨钙素mRNA Northern印迹分析;体内实验将细胞载人多孔β—TCP立方块形成MSCs／β-TCP复合物,继续成骨诱导培养2周后植入大鼠背部皮下,4周和8周后取出复合物作组织学检查。结果FKS06处理组碱性磷酸酶活性、钙含量、骨钙素mRNA均明显高于对照组（均P〈0．05）;体内成骨情况亦明显优于对照组。结论免疫抑制剂FKS06能显著促进大鼠骨髓来源间充质干细胞（MSCs）的体外成骨细胞分化和动物体内继续成骨的作用,并提示FKS06可作为一种新型成骨生长因子,在临床有潜在的应用价值。     

成骨不全家系一个新的Ⅰ型胶原α1链蛋白基因突变

目的 对Ⅰ型胶原α1链蛋白基因（COL1A1基因）进行测序研究，旨在寻找已知或未知的COL1A1基因突变位点，探讨我国成骨不全的发病机制。方法 研究一常染色体显性遗传成骨不全家系的临床特征，设计引物对家系中患者和正常人的COL1A1基因外显子进行扩增和测序分析，同时对群体中无血缘关系的50名健康对照者进行限制性内切酶分析。结果 发现家系中成骨不全患者COL1A1基因的第3470位点的碱基G→A的突变，导致G1157D，而在家系内非患者及正常对照者中均无发现。结论 COL1A1基因突变也是中国人群中成骨不全致病原因之一，现发现的突变属成骨不全一个新的致病基因突变。甘氨酸转变成天冬氨酸的这种突变对成骨不全表型具有重要的影响。     

自制股骨头骨髓置管器治疗股骨头缺血性坏死的临床研究

目的:介绍自制股骨头骨髓置管器的构造及评价治疗股骨头缺血性坏死的疗效。方法:自制股骨头骨髓置管器治疗股骨头缺血性坏死38例和Legg-Perthes病3例。按Ficat分期,Ⅰ期4例,Ⅱ期26例,Ⅲ期7例,IV期1例;Legg-Perthes病3例,按Herring标准分型均为C型。临床诊断根据症状、体征、X线片及CT或MRI,最后由病理检查确诊。治疗1周,以治疗前后临床症状、骨髓对比、骨髓压力的变化及X线随访作为疗效观察指标,评价其疗效。结果:33例(Ⅰ-Ⅱ期及3例Legg-Perthes病)疼痛明显改善,髋关节功能提高,8例缓解;治疗前的骨髓压都大于50 cm H2O,经治疗后骨髓压都降到10 cm H2O以下;股骨头骨髓对比显示33例(Ⅰ-Ⅱ期及3例Legg-Perthes病)股骨头病灶区域对比剂弥散良好,8例弥散稍好,所有患者静脉回流都有改善;31例治疗后随访3年,其中23例(20例为Ⅰ-Ⅱ期和3例为Legg-Perthes病)X线片显示有不同程度的骨质修复,Ⅲ-Ⅳ期的8例未见明显修复征象,与术前比较情况相仿。结论:自制股骨头骨髓置管器是治疗Ⅰ、Ⅱ期股骨头缺血性坏死及Legg-Perthes病的有效方法,对Ⅲ、Ⅳ期股骨头缺血性坏死在缓解症状及延缓病程上具有明显的效果。