血管内皮生长因子在骨折愈合中的作用

目的　研究血管内皮生长因子 (VEGF)在骨折愈合过程中的作用 ,探讨应用 VEGF及拮抗VEGF对骨折愈合所产生的影响。方法　利用新西兰大耳白兔 10 5只制作左侧桡骨中段骨折动物模型 ,随机分成三组 ,两组分别应用 VEGF多克隆抗体及 VEGF,另一组为对照组 (不作任何处理 )。在伤后 8、2 4、72小时和 1、3、5、8周利用单光子放射计算机断层显像术测定骨折端血流量变化 ,在 1、3、5及 8周摄 X线片观察骨折愈合情况。结果　应用 VEGF使骨折端血流量在 8小时～ 3周较对照组增高 ,但 X线片却未见明显差异 ;而 VEGF多克隆抗体可导致骨折端血流量在各时相点较对照组明显减少 ,并阻碍了骨折的愈合进程 ,最终使骨折端形成骨不连样改变。结论　骨折愈合过程中缺乏 VEGF将严重影响骨折的正常愈合过程 ,并导致骨不连接 ,应用外源性 VEGF可能通过增加骨折端血流量而对骨折愈合有益     

血管内皮生长因子在骨折修复过程中血管生成的促进作用

目的观察血管内皮生长因子(VEGF)在骨折修复过程中对骨折端微血管密度(MVD)的影响，探讨VEGF在骨折端血管生成中的作用。方法用168只大白鼠制作股骨骨折模型，随机分为VEGF组、拮抗VEGF组、对照组，用免疫组织化学分别测定伤后不同时间骨折端MVD的变化。结果应用外源性VEGF后。骨折端MVD明显增加；拮抗VEGF组，骨折端MVD明显下降；对照组MVD低于VEGF组，但高于拮抗VEGF组。结论VEGF在骨折修复过程中，对血管生成具有重要作用，并可能作为一种重要细胞因子参与和调节了骨折修复过程。     

血管内皮生长因子对骨折愈合相关因子表达的调控

目的探讨应用和拮抗血管内皮生长因子(VEGF）对骨折愈骨相关因子表达的影响，并观察骨折愈台过程中的病理改变。方法用105只天上I=白兔制作骨折模型．随机分为对照组、应用VECF组和拮抗vEGF组，分别于伤后8、24、72b和1．3、5、8周测定各组动物骨折端相关因子的表达变化、同时取骨折端标本脱钙进行兜镜观察。结果应甩VEGF使骨折端埘BMP的表达时同提前和延良，拈抗VEGF抑制rBMP的表达，应用VEGF组伤后3J嗣时骨折端充填有纤维性骨痴，软骨骨痂和骨性骨痂．5周时新生骨以编织骨为主，8周时骨折正常愈合；括抗VH押导受伤后初期骨细胞坏死增多，1～5周各时相点骨折端均有灶性坏死出现，3同时骨折部位血管生成明显减少。结论骨折愈台过程需要多因子参与、协调，VEGF有可能是作为骨折愈台过程中的一种重要因子在发挥作用     

微动对骨折端微循环及血管内皮生长因子(VEGF)表达的影响

目的研究外固定架微动对骨折端微循环及血管内皮生长因子(VEGF)表达的影响。方法60只新西兰大白兔随机分为微动组与固定组,利用微循环检测仪、免疫组化等方法检测固定组和微动组动物骨折端血流量、VEGF蛋白表达。结果微动组骨折端血流量在骨折后2、3、4、5周较固定组有显著增加。骨折后3、4、5周微动组骨折端软骨细胞、成骨细胞中VEGF蛋白表达均较固定组增强。结论微动可以增加VEGF表达,使毛细血管再生增加,促进骨痂生长。     

血管内介入疗法防治骨折不愈合实验研究

目的: 研究血管内介入疗法防治骨折不愈合的作用。方法: 将 45只山羊的右胫骨中段截去 2. 5cm用钢板固定制成骨折不愈合模型, 随机分成血管内介入给药组、静脉全身给药组和对照组, 每组 15只, 术后 1周给药, 对照组不给药。分别应用单光子放射计算机断层成像术 (SPECT) 测定骨折端不同时相血流量变化, 摄X线片对比研究, 并取骨折端标本脱钙进行光镜和电镜观察。结果: 血管内介入给药组骨折端血流量在一定时间内较另两组明显增高 (P<0. 01 ), 且峰值期延长, 改良的X线Gary评分及组织学观察结果均优于静脉全身给药组和对照组。结论: 血管内介入疗法能增加骨折端血流量, 促进骨折愈合, 预防骨折不愈合形成。     

海水浸泡开放性骨折伤愈合过程中组织病理学和血管内皮细胞生长因子(VEGF)表达

目的通过观察普通开放骨折、海水浸泡开放骨折愈合过程的组织学变化和骨痂中血管内皮细胞生长因子(VEGF)的表达,了解海水浸泡开放性骨折愈合过程VEGF的作用与机制。方法新西兰大白兔59只,随机分为普通开放骨折组(对照组)24只和海水浸泡开放骨折组(实验组)35只。造成桡骨横行1.5mm缺损完全开放骨折,普通开放骨折伤组旷置3h,海水浸泡开放骨折伤组海水浸泡伤口3h,之后依次缝合伤口。于第1、3、7、14、21、28、45天处死动物。观察海水浸泡开放骨折伤在骨折愈合中不同时间的病理过程。采用RT-PCR方法检测普通开放骨折、海水浸泡开放骨折不同阶段骨痂中的VEGF的表达及变化。结果海水浸泡开放骨折伤骨痂形成延迟,骨折后第28天,对照组断端间骨痂为骨性骨痂者8例,为软骨者4例,实验组断端间骨痂为骨性骨痂者6例,为软骨者14例。海水浸泡骨折伤愈合过程中新生骨痂的VEGF表达在骨折后逐渐升高,术后14d达到高峰,之后逐渐下降,但在28d时仍保持较高水平,与一般开放骨折愈合过程的VEGF表达无显著差异(P>0.05)。结论海水浸泡使骨折骨痂形成不良率增高,骨折愈合过程有延迟倾向;但骨折愈合过程中VEGF表达无明显变化。     

糖尿病大鼠骨折后血管内皮生长因子的变化

目的 观察糖尿病大鼠骨折后血管内皮细胞生长因子（VEGF）的变化。方法 70只清洁雄性Wistar大鼠随机分为对照组和链脲佐菌素（stz）诱导的速发型糖尿病组，线锯锯断两组大鼠左胫骨后复位外固定。于骨折后1、2、3、4、6、8周取静脉血保留血清；大鼠左下肢X线片观察骨折愈合情况；取骨折断端组织行HE染色光镜观察、免疫组织化学检测VEGF；酶联免疫吸附分析法（EHsa）检测血清VEGF。结果 糖尿病组4周可以看见纤维骨痂，8周才有较多骨性骨痂出现，较对照组明显滞后；HE染色镜下观察糖尿病组骨形成滞后；3周VEGF免疫组织化学灰度值两组间差异有统计学意义，（实验组142．8±3．8；对照组128．0±5．5，P〈0．01）；两组血清中VEGF差异元统计学意义（P〉0．05）。结论 糖尿病大鼠骨折后血清中VEGF未减少，局部组织VEGF含量低是导致糖尿病大鼠骨折愈合差的原因之一。     

氟伐他汀对骨质疏松大鼠骨折愈合过程中血管内皮生长因子的影响

目的探讨氟伐他汀对骨质疏松大鼠骨折愈合过程中血管内皮生长因子（VEGF）的影响。方法卵巢切除后3个月已经出现骨质疏松的SD大鼠72只,于股骨中段制造骨折模型,再随机分为给药组和对照组,每组36只,给药组手术次日给予10mg/kg.d氟伐他汀灌胃,疗程为6w,对照组给予安慰剂。利用免疫组化及原位杂交检测骨折愈合过程中给药组和对照组骨折后3、7、14、21、28和42d骨痂中VEGF、VEGF mRNA的表达,并用真彩色图像分析仪作图像分析。结果给药组和对照组在骨折愈合过程中VEGF及VEGF mRNA基因表达的细胞定位无差别,且表达模式基本相似。术后14d,阳性细胞的阳性程度给药组比对照组显著性强（P〈0.05）。结论氟伐他汀对骨质疏松大鼠骨折愈合过程中VEGF的合成分泌有一定促进作用。     

不同固定方式对骨痂中血管内皮细胞生长因子表达的影响

目的：通过观察内、外固定骨折愈合过程骨痂组织内血管内皮细胞生长因子（vascular endothelial growth fac-tor,VEGF）的基因表达,进一步探讨骨折固定方式与VEGF及骨折愈合的关系。方法：采用RT－PCR方法检测闭合性骨折内固定（n=4）或外固定（n=4）兔骨折不同阶段（5、7、14、28、42d）骨痂组织中VEGF基因的表达及变化。结果：外固定组与内固定组相比,VEGF基因表达出现早,表达量高。结论：内固定损伤了骨膜,影响了骨痂及血管皮细胞的形成,选择骨折固定方式明应慎重。     

骨折端Ⅷ因子相关抗原与血流量的实验研究

目的 研究骨折愈合过程中骨折端Ⅷ因子相关抗原和血流量变化的规律及其相关性。方法 选用35只大耳白兔制作左侧桡骨骨折动物模型，分别于伤后8、24、72h。1、3、5、8周利用单光子放射计算机断层显像术(Single Photon Emission Computerized Tomography，SPECT)测定骨折端血流量变化，之后取骨折端标本提取蛋白样本定量检测Ⅷ因子相关抗原。结果 骨折端血流量在致伤后8h开始上升，1周时达顶峰，高血流量状态一直维持到第3周，第5和第8周基本恢复到正常水平；骨折端Ⅷ因子相关抗原在伤后24h开始增高，骨折后3天达到较高的水平，该状态一直维持到骨折后的第3周。到第5周时开始出现较明显的回落，第8周时基本恢复到正常水平。结论 伤后72h骨折端血流量增高与骨折端血管生成有关，早期的血流量增加可能与骨折后的创伤反应有关。     

Regulation of vascular endothelial growth factor on the expression of fracture healing,related factors

Objective ： To study the effect of vascular endothelial growth factor （VEGF）and anti-VEGF on the expression of fracture healing-related factors and observe pathological changes at fractured sites. Methods： Fracture models were established in 105 New Zealand white rabbits and they were randomly divided into control group, VEGF group and anti-VEGF group. The relevant factors expression at fractured sites was assayed and pathological changes were observed in decalcified samples at 8, 24, 72 hours and 1,3,5,8 weeks after fracture. Results： After application of VGEF, the expression of BMP appeared earlier and expression time lasted longer. On the contrary, anti-VEGF completely inhibited the expression of BMP. The fractured sites were filled with fibrous callus, cartilaginous callus and bony callus at the 3rd week and woven bone was constructed at the 5th week. Fracture healing was accomplished at the 8th week in VEGF group. In anti-VEGF polyclonal antibody group, cellular necrosis increased at early period. Continuous focal necrosis was seen in the fractured sites from the 1st week to 5th week. Vascularization reduced obviously at the 3rd week. Conclusions： Fracture healing is a result of mutual regulation and coordination among many factors. VEGF may be an important factor in fracture healing.     

成骨细胞移植促进老龄鼠骨质疏松性骨折愈合过程中VEGF的动态变化

目的：动态观察在幼龄成骨细胞移植促进骨质疏松性骨折愈合过程中，VEGF在不同时相的表达及其生物学意义。方法：通过建立老龄骨质疏松SD大鼠骨折的动物模型，并将体外培养的SD雄性乳鼠成骨细胞移动到SD雌性鼠老年骨质疏松性骨缺损部位，利用免疫组化及原位杂交检测骨折愈合过程中不同时间相的移植标本VEGF、VEGFmRNA的表达，并作图像分析、绘出其动态变化图。结果：实验组VEGF、VEGFmRNA均在7d左右可见有阳性表达的细胞，14d有分泌,高峰其中以软骨细胞中阳性最强，21 d分泌量开始下降，56d后基本消失。而对照且未见明显分泌高峰。结论；成骨细胞细胞促进老龄鼠骨质疏松性骨折愈合，其机制可能是通过促进VEGF的转录和表达，从而促进骨折部位建立良好的血液循环，加速骨形成。     

Effect of fluvastatin on vascular endothelial growth factor in rats with osteoporosis in process of fracture healing

OBJECTIVE: To explore the effect of fluvastatin on vascular endothelial growth factor (VEGF) in rats with osteoporosis in the process of fracture healing. METHODS: Fractures at the intermediate piece of the femur were made on 72 Sprague Dawley (SD) rats (weighing initially 290-340 g and aged 6 months) with osteoporosis after ovariectomy for three months, then these rats were divided randomly into the medication administration group (the experimental group) and the control group, 36 rats each. In the experimental group, the rats received fluvastatin lavage (10 mg/kg per day) since the next day of operation lasting for 6 weeks, and the rats in the control group received placebo. Then the expression of VEGF and VEGF mRNA in bony callus of the two groups was measured respectively with immunohistochemistry and in situ hybridization on days of 3rd, 7th, 14th, 21st, 28th, and 42nd, and image analysis was made with real-color image analysis machine. RESULTS: No difference was found in the cellular localization of VEGF and VEGF mRNA gene expression between the experimental group and the control group in process of fracture healing and their expression modes were almost similar. On the 14th day postoperatively, the positive extent of positive cells in the experimental group was higher than that of the control group (P < 0.05). CONCLUSION: Fluvastatin can promote the VEGF level in rats with osteoporosis in process of fracture healing.     

Effect of bisphosphonate (incadronate) on fracture healing of long bones in rats.

This study was designed to test whether bisphosphonates disturb the process of fracture healing. Female Sprague-Dawley rats were injected with either two doses of bisphosphonate (incadronate) (10 microg/kg and 100 microg/kg) or vehicle three times a week for 2 weeks. Right femora were then fractured and fixed with intramedullary wires. Incadronate treatment was stopped in pretreatment groups (P-10 and P-100 groups), while the treatment was continued in continuous treatment groups (C-10 and C-100 groups). Animals were sacrificed at 6 and 16 weeks after surgery. Soft X-ray of all fractured femora was taken. After mechanical testing, fractured femora were stained in Villanueva bone stain and embedded in methyl methacrylate. Cross-sections near fracture line were analyzed by microradiography and histomorphometry. Radiographic study showed that bony callus was present in all the fractures and incadronate treatment led to a larger callus, especially in C-100 group at both 6 and 16 weeks. Histologic study showed that the process of fracture healing in pretreatment groups was delayed at 6 weeks, but reached control level thereafter and showed same characteristics as in control at 16 weeks. Woven bony callus could still be seen in continuous treatment groups at 16 weeks. Mechanical study indicated that the ultimate load of C-100 group was slightly higher than the other treatment groups and control. The results suggest that pretreatment with incadronate did not affect fracture healing at 16 weeks after fracture. However, continuous incadronate treatment could lead to larger callus, but it delayed remodeling process during fracture healing, especially with high-dose treatment.     

VEGF serum concentrations in patients with long bone fractures: A comparison between impaired and normal fracture healing

Vascular endothelial growth factor (VEGF) plays an important role in the bone repair process as a potent mediator of angiogenesis and it influences directly osteoblast differentiation. Inhibiting VEGF suppresses angiogenesis and callus mineralization in animals. However, no data exist so far on systemic expression of VEGF with regard to delayed or failed fracture healing in humans. One hundred fourteen patients with long bone fractures were included in the study. Serum samples were collected over a period of 6 months following a standardized time schedule. VEGF serum concentrations were measured. Patients were assigned to one of two groups according to their course of fracture healing. The first group contained 103 patients with physiological fracture healing. Eleven patients with delayed or nonunions formed the second group of the study. In addition, 33 healthy volunteers served as controls. An increase of VEGF serum concentration within the first 2 weeks after fracture in both groups with a following decrease within 6 months after trauma was observed. Serum VEGF concentrations in patients with impaired fracture healing were higher compared to the patients with physiological healing during the entire observation period. However, statistically significant differences were not observed at any time point between both groups. VEGF concentrations in both groups were significantly higher than those in controls. The present results show significantly elevated serum concentrations of VEGF in patients after fracture of long bones especially at the initial healing phase, indicating the importance of VEGF in the process of fracture healing in humans. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1293–1297, 2009     

Role of dual energy X-ray absorptiometry in monitoring fracture healing in a rat femoral fracture model

Earlymobilizationandweightbearingplayimportantrolesinminimizingtheamountofbonelosstoachievegoodhealingafterbonefracture.1Areliableandnoninvasivemethodforevaluatingfracturehealingcannotonlyhelpdecidewhentostarweightbearing, butalsohelpdetecttheimpairedboneunionearlytopreventdelayedunionsornonunions.However, objectivequantitativemethodsforearlyevaluationoffracturehealinghavenotbeendevelopedyet. DualenergyX rayabsorptiometry(DEXA)isoneofthemostaccuratemethodsformeasuringbonemassinvivo. Itismain…