膜内成骨与软骨成骨贴敷移植的早期血管化比较研究

目的采用Ｗｉｓｔａｒ大鼠对颅骨（膜内成骨）和髂骨（软骨成骨）贴敷移植后早期再血管化进行了观察研究。方法用计算机图像处理进行定量分析。结果骨移植７天后,软骨成骨与膜内成骨血管密度分别为：２２３３％和１１８８％;１４天时分别为３４９３％和１５９３％。结论软骨成骨移植后较膜内成骨有更加迅速的血管化。文中对骨移植后骨质结构,血管化以及骨质体积存留之间的关系进行了讨论。     

膜内成骨与软骨成骨贴敷移植的早期血管化比较研究

目的采用 Wistar 大鼠对颅骨(膜内成骨)和髂骨(软骨成骨)贴敷移植后早期再血管化进行了观察研究。方法用计算机图像处理进行定量分析。结果骨移植7天后,软骨成骨与膜内成骨血管密度分别为:22.33%和11.88%;14天时分别为34.93%和15.93%。结论软骨成骨移植后较膜内成骨有更加迅速的血管化。文中对骨移植后骨质结构,血管化以及骨质体积存留之间的关系进行了讨论。     

骨质疏松性骨折膜内成骨和软骨内成骨特点的定量研究

目的通过去势大鼠骨折模型,探讨骨质疏松性骨折愈合过程中膜内成骨和软骨内成骨的特点。方法57只6月龄雌性SD大鼠,随机分为卵巢切除组(OVX)和对照组(SHAM),术后3个月pQCT随访观察到OVX组的骨密度(BMD)显著下降。随后OVX组和SHAM组均构建闭合性股骨骨折模型,每周摄X线片随访骨折愈合情况并行骨痂定量分析。第2、4、8周取材,行显微CT(micro-CT)三维骨痂定量分析和组织学分析,并于第8周采集标本进行生物力学测试。结果SHAM组膜内成骨的新生骨量在骨折愈合早期显著高于OVX组(P=0.031),骨折区域的软骨形成也较OVX组活跃,但未构成显著性差异。随着软骨内骨化的进行,SHAM组软骨内成骨区域的新生骨量显著高于OVX组(P=0.023)。骨折后8周时,SHAM组骨折愈合率高于OVX组,生物力学强度也明显优于OVX组(P=0.044)。结论骨质疏松对骨折愈合中膜内成骨和软骨内成骨的过程均产生负性作用,其分子生物学机制有待进一步探讨。     

分别构建膜内成骨和软骨内成骨骨修复模型的研究

[目的]分别构建膜内成骨骨修复模型和软骨内成骨骨修复模型。[方法]取BALB/c小鼠64只,随机分为骨皮质钻孔模型组和骨膜划痕模型组。骨皮质钻孔模型组在小鼠右侧胫骨前内侧实施单纯性骨皮质钻孔损伤用于构建膜内成骨模型;骨膜划痕模型组在小鼠右侧胫骨前内侧实施骨膜划痕损伤用于构建软骨内成骨模型。术后第7、10、14和21 d,每组每个时间点处死8只小鼠,观察损伤部位的组织修复。[结果]骨皮质钻孔模型组小鼠损伤后第7 d在损伤部位出现新生小梁骨构成的骨痂组织。损伤后第10 d新生小梁骨充满损伤骨皮质及骨髓腔。损伤后第14 d新生骨痂组织进入改建过程,至第21 d,多数骨痂组织基本改建完成。在修复过程中无软骨细胞出现。骨膜划痕模型组小鼠损伤后第7 d在损伤部位出现新生软骨组织构成的软骨痂,并有部分软骨细胞已分化为成熟软骨细胞。损伤后第10 d软骨痂中心区域软骨基质溶解,第14 d后新生小梁骨出现,逐渐替代软骨组织。损伤后第21 d,软骨痂已基本被骨小梁替代。在修复过程中,首先出现软骨基质形成的骨痂组织,随后骨化中心形成,骨性骨痂组织逐渐替代软骨,完成骨修复。[结论]成功构建了以膜内成骨方式愈合的骨修复模型和以软骨内成骨方式愈合的骨修复模型,为今后深入研究骨愈合机制提供了基础。     

膜状成骨与软骨成骨帖附移植后的组织学观察及骨计量学分析

OBJECTIVE: The experimental study was to determine the differences in changes in the onlay bone grafts of different embryonic origin. METHODS: The study was designed to compare the potential for appositional bone growth in membranous and endochondral onlay grafts in New-Zealand rabbits and a rhesus monkey. Results were assessed with volumetric measurement, histological examinations and stereologic analysis with double-fluorochrome labeling technique. RESULTS: For the membranous and endochondral bone grafts, the volumetric retention rate was (78.4 +/- 3.5)% and (56.0 +/- 5.1)% respectively. The mineralization apposition rate (MAR) was (3.6 +/- 0.8) microns/d and (0.92 +/- 0.33) micron/d; the osteoid seam width (OSW) was (14.56 +/- 2.69) microns and (7.38 +/- 2.20) microns; the tetracycline uptake rate(TUA) was (91.22 +/- 2.69)% and (51.28 +/- 4.11)%, respectively. CONCLUSION: 1. It was found that the membranous bone graft maintained its volume to a significantly greater extent than the endochondral bone graft; 2. Membranous bone grafts exhibited higher survival rate and greater activity than endochondral bone grafts; 3. Different changes were also found in the two recipient sites. There was more powerful bone regenerative reaction in the recipient bed of the membranous bone graft than the endochondral one.     

软骨内成骨中的细胞凋亡现象

软骨内成骨包括软骨细胞的增殖、成熟、肥大和退化以及凋亡等步骤,软骨细胞凋亡是实现由软骨细胞向骨形成细胞转换的重要步骤,过分凋亡或延迟凋亡都将导致骨骼发育异常。甲状旁腺激素相关肽和碱性成纤维细胞生长因子具有间接抑制细胞凋亡的作用。     

骨形态发生蛋白2与血管内皮生长因子在软骨内成骨过程中的基因表达

目的 检测并分析骨形态发生蛋白2(BMP-2)及血管内皮生长因子(VEGF)在骨发育基因表达谱及诱导成骨过程中表达规律及相互作用,为工程化BMP-2蛋白在骨科临床治疗中的运用提供依据.方法 应用基因芯片技术建立妊娠胎鼠肢芽发育成骨过程的基因表达谱,分析BMP-2与VEGF在发育成骨过程中的表达规律;检测VEGF mRNA在小鼠外源性工程化BMP-2蛋白体内诱导软骨内成骨过程中表达情况,结合组织学、免疫组织化学观察结果与基因表达谱分析结果,分析BMP-2与VEGF在软骨内成骨过程中的相互作用.结果 BMP-2及VEGF在发育成骨过程的基因表达谱中以及VEGF表达信号在外源性BMP-2诱导的体内软骨内成骨过程中,均呈现以诱导间质细胞向软骨细胞分化-肥大-吸收直至骨形成这一过程为轴线的时间-浓度表达关系.结论 BMP-2及VEGF在骨发育及诱导成骨过程中均存在协同促进作用,工程化BMP-2蛋白将在骨科临床治疗中得到更广泛的运用.     

软骨内成骨的调控

骨骼的纵向生长不仅需要激素的调节，同时也需要旁分泌的局部调节因子的调节，因而调节因子可分为系统性调节因子和局部调节因子。系统性调节因子包括生长激素、甲状腺素、雌激素、雄激素、维生素D3、视黄酸及皮质激素等。局部调节因子包括骨形态发生蛋白（BMPs）、成纤维细胞生长因子（FGFs）、Ihh／甲状旁腺素相关肽（PTHrP）及类视黄醇等，它们与核内转录因子相互作用，调节与控制软骨内成骨的进程。现对近年来软骨内成骨的主要调节因子研究综述如下。     

Indian hedgehog在软骨内成骨和骨关节炎中作用的研究进展

Hedgehog基因,最初是在研究果蝇的基因突变时发现的,该基因突变的果蝇胚胎酷似受惊刺猬,因此而得名。目前研究表明:在脊椎动物中存在音速豪猪蛋白(sonic hedgehog,Shh),沙漠豪猪蛋白(deserthedgehog,Dhh)和印度豪猪蛋白(Indian hedgehog,Ihh)三种Hedgehog蛋白亚型。其中Shh参与胚胎肢芽不对称性发育和中枢神经系统的发育过程;Dhh是生殖系统和外周神经系统发育过程中重要的调控因子;Ihh则在软骨内成骨和骨关节炎(OA)的发生发展中发挥着重要的作用。本文主要关注其在软骨内成骨和OA中对软骨细胞的作用。     

血管化骨-重组异种骨移植修复骨缺损

目的 探讨血管化骨-重组异种骨(RBX)移植修复骨缺损的意义。方法 27例骨缺损随机分成3组，A组为血管化骨-RBX移植修复组(9例)；B组为血管化骨移植修复组(10例)；C组为RBX移植修复组(8例)。临床评价以术后3个月、6个月、12个月随访的X线片来判断骨缺损是否修复、骨愈合时间长短以及是否再吸收等。结果 术后3个月A组8例、B组6例、C组3例骨愈合，6个月A组1例、B组3例、C组3例骨愈合，12个月B组1例、C组2例发生骨移植区部分再吸收。结论 血管化骨一重组异种骨移植的骨折愈合率明显优于单纯重组异种骨移植。     

膜状成骨与软骨成骨贴附移植后的组织学观察及骨计量学分析

目的深入探讨骨贴附移植后的变化及不同胚胎来源骨质(膜状成骨和软骨成骨)移植后的差异。方法应用新西兰兔、恒河猴采用荧光素双标记法,在不脱钙骨切片上,选用类骨质宽度、骨质矿化沉积率、荧光标记率等骨动力学指标对骨移植后的再生和改建进行计算机图像分析和定量测量。结果骨体积存留率:膜状成骨为(78.4±3.5)%,软骨成骨为(56±5.1)%;骨矿化沉积率:膜状成骨为(3.60±0.8)μm/d,软骨成骨为(0.92±0.33)μm/d;类骨质宽度;膜状成骨为(14.56±2.69)μm,软骨成骨为(7.38±2.20)μm;荧光标记率:膜状成骨为(91.22±2.69)%,软骨成骨为(51.28±4.11)%。结论膜状成骨移植后较软骨成骨可保持更多的骨质体积,有更为明显的成骨再生能力且可诱导宿主骨成骨的能力不同,膜状成骨优于软骨成骨。     

膜状成骨与软骨成骨贴附移植后的组织学观察及骨计量学分析

目的深入探讨骨贴附移植后的变化及不同胚胎来源骨质（膜状成骨和软骨成骨）移植后的差异。方法应用新西兰兔、恒河猴采用荧光素双标记法,在不脱钙骨切片上,选用类骨质宽度、骨质矿化沉积率、荧光标记率等骨动力学指标对骨移植后的再生和改建进行计算机图像分析和定量测量。结果骨体积存留率：膜状成骨为（７８４±３５）％,软骨成骨为（５６±５１）％;骨矿化沉积率：膜状成骨为（３６０±０８）μｍ／ｄ,软骨成骨为（０９２±０３３）μｍ／ｄ;类骨质宽度;膜状成骨为（１４５６±２６９）μｍ,软骨成骨为（７３８±２２０）μｍ;荧光标记率：膜状成骨为（９１２２±２６９）％,软骨成骨为（５１２８±４１１）％。结论膜状成骨移植后较软骨成骨可保持更多的骨质体积,有更为明显的成骨再生能力且可诱导宿主骨成骨的能力不同,膜状成骨优于软骨成骨。     

颅面部贴附植骨的实验研究

目的 探讨颅面骨表面贴附植骨吸收的内在机理。方法 实验用30只成年雄性新西兰白兔,随机均分成两组,采用自体颅有及肋骨块贴附移植于颅面骨表面。术后12周及24周分别取材,行大体观察,体积测量,组织学观察及电镜观察。结果 颅骨吸收少,移植骨皮质部在吸收改建过程中变化较大,颅骨或肋嘣骨胶原纤维的数量及排列24周比12周多而有规律。12周时,颅骨骨胶原纤维的数量及排列优于肋骨,而24周时,两种骨无差别,移植骨即使已经成活,内部构造还未完全成熟,移植骨体积进一步减少。结论 颅面部贴附植骨膜内化骨优于软骨内化骨,移植骨的皮质部是导致两种骨吸收不同的关键部位,移植骨的体积维持也与应力有关。     

The fate of onlay membranous bone grafts in different facial recipient sites

Summary The fate of onlay bone grafts was studied in the growing rabbit facial skeleton with regard to the depository and resorptive characteristics of bone surfaces. The nasal snout was chosen as the depository field and the vestibular surface of the mandibular ramus as the resorptive field. The membranous bone graft applied on a depository surface maintained its volume and morphology significantly better than the graft placed on a resorptive field. There was no evident difference between the fate of full-thickness and split-thickness membranous bone grafts in the different facial recipient beds. The authors suggest that the reconstructive procedures to improve the facial skeleton contour in growing children should be planned keeping in mind the depository or resorptive characteristics of the facial recipient site.     

The fate of onlay membranous bone grafts in different facial recipient sites

The fate of onlay bone grafts was studied in the growing rabbit facial skeleton with regard to the depository and resorptive characteristics of bone surfaces. The nasal snout was chosen as the depository field and the vestibular surface of the mandibular ramus as the resorptive field. The membranous bone graft applied on a depository surface maintained its volume and morphology significantly better than the graft placed on a resorptive field. There was no evident difference between the fate of full-thickness and split-thickness membranous bone grafts in the different facial recipient beds. The authors suggest that the reconstructive procedures to improve the facial skeleton contour in growing children should be planned keeping in mind the depository or resorptive characteristics of the facial recipient site.     

Absorption of onlay bone grafts in immature rabbits: membranous versus enchondral bone and bone struts versus paste

The absorption of onlay membranous and enchondral bone graft struts and paste was studied in immature New Zealand rabbits using a volume-displacement technique to determine the volume change in the grafts 8 weeks and 21 weeks after grafting. Membranous and enchondral bone paste does not survive as an onlay graft. Both enchondral and membranous bone graft struts undergo significant resorption (78% decreased volume in the enchondral grafts and 50% in the membranous bone grafts). These data support the clinical experience that both types of onlay bone grafts lose significant volume, and are in relative contradistinction to prior animal studies comparing membranous and enchondral onlay bone grafts.     

Follow-up study of the revascularization process of purified rat islet beta-cell grafts

The revascularization of islets of Langerhans transplanted in heterotopic sites like the liver by portal vein embolization or the renal subcapsular space is a major process necessary for the viability of grafted cells. This process has been extensively studied by different techniques and the results have shown that islet revascularization is an early phenomenon that takes place soon after transplantation. In this report we have analyzed by a double indirect immunofluorescence technique, the revascularization process of purified endocrine islet beta-cells transplanted in the renal subcapsular space of syngeneic rats. Lewis rats were grafted with islets cultured for 24 h, with a suspension of purified beta-cells cultured for 24 h, and with a suspension of purified beta plus nonbeta-cells cultured for 24 h. Rats were killed at different days after implantation and the kidney bearing the grafts were snap frozen and immunohistochemically stained with a rabbit anti factor VIII antiserum (which labels endothelial cells). Immunocytochemical analysis revealed that cultured islets completed revascularization by days 3–5 after transplantation, as shown by the detection of capillary endothelial cells within and surrounding the islets. Within purified endocrine beta-cell grafts, the presence of numerous endothelial cells was not observed until days 10–14, indicating that revascularization of beta-cells with host vessels is not such an early phenomenon as it takes place in whole isolated islets. Conversely, the addition of a population of endocrine nonbeta-cells to the purified islet cell grafts, partially accelerated the revascularization of pure beta-cell grafts, which showed the presence of abundant capillary endothelial cells already at day 7 after transplantation, indicating that some other unidentified factors besides the absence of endothelial cells may explain the retardation of beta-cell grafts revascularization.