肌注神经生长因子及血小板衍生生长因子对胫骨干闭合骨折大鼠早期骨愈合的影响及机制探究

摘要 目的：探讨肌肉注射神经生长因子（NGF）和血小板衍生生长因子（PDGF）对胫骨干闭合骨折大鼠早期骨愈合的效果及潜在机制。方法：采用随机数字表法将80只健康成年雄性SD大鼠分为模型组、NGF组、PDGF组和NGF+PDGF组,各20只。建立胫骨干闭合骨折模型后,给予NGF组大鼠肌注0.8 μg NGF;给予PDGF组大鼠肌注0.8 μg PDGF,给予NGF+PDGF组大鼠肌注0.8 μg NGF和0.8 μg PDGF;给予模型组大鼠肌注等体积生理盐水。分别在治疗第2周（T0）、第4周（T1）、第6周（T2）通过X线检查计算骨痂体积,采用酶联免疫吸附法检测血清中碱性磷酸酶（AKP）水平。颈椎脱臼法处死大鼠后采用苏木精-伊红（HE）染色观察胫骨骨折端病理学改变,采用实时荧光定量PCR法检测骨痂组织骨形态发生蛋白2（BMP2）、血管内皮生长因子（VEGF）和胰岛素样生长因子-1（IGF-1）mRNA相对表达水平。结果：NGF+PDGF组大鼠在T1时骨折断端愈合,骨痂体积大于其他三组;NGF组、PDGF组大鼠在T2时骨折断端愈合,骨痂体积大小均大于模型组（P<0.05）。模型组大鼠T2时骨折断端尚未完全愈合,骨痂体积显著大于其他三组（P<0.05）。NGF+PDGF组大鼠T0~T1时血清AKP水平均显著高于其他三组,NGF组和PDGF组大鼠血清AKP水平显著高于模型组（P<0.05）。T2时4组大鼠血清AKP水平比较无显著差异（P>0.05）。T1时,NGF组、PDGF组和NGF+PDGF组大鼠均可见骨小梁形态更加粗大、致密,呈栅栏状排列,骨小梁间的间隙变小,NGF+PDGF组大鼠骨断裂处被新生骨填满,NGF组、PDGF组骨断裂处仍有少量间隙。T1时NGF+PDGF组大鼠BMP2、VEGF和IGF-1相对表达水平均显著高于其他三组（P<0.05）,NGF组和PDGF组大鼠各指标mRNA相对表达水平比较无显著差异（P>0.05）,但均显著高于模型组（P<0.05）。T2时各组大鼠骨痂组织中BMP2、VEGF和IGF-1 mRNA相对表达水平比较无显著差异（P>0.05）。结论：NGF和PDGF对胫骨干闭合骨折大鼠早期骨愈合有协同促进作用,可能与促进BMP2、VEGF和IGF-1表达上调有关。     

超声促进骨折愈合

统计显示,有5～10％的骨折可因各种原因发生骨折延迟愈合或不愈合。促进骨折愈合的研究开展广泛,涉及骨、骨髓移植;骨生长因子的应用;机械、电刺激等多方面。超声促进骨折愈合的临床和实验性研究早在六十年代即展开。本文就其近年来研究状况作一系统回顾。 1 基本原理 超声促进骨折愈合的机理尚未明确,认     

骨折磁疗愈合仪治疗骨折延迟愈合

骨折延迟愈合是指骨折在正常愈合所需的时间内,仍未能达到骨折完全愈合的标准。临床症状与体征：４个月的异常活动;骨端在移位或试做负重时,产生疼痛;畸形与肌萎缩;负重功能丧失;骨传导音降低。我科应用骨折磁疗愈合仪治疗骨折延迟愈合３０例收到了满意效果。３０例患者中应用骨折磁疗愈合仪４０天骨痂形成的２０例,５０天骨痂形成的１０例。治疗方法１将患肢固定在不负重石膏管形内,安置线圈时须用Ｘ线准确定位,使两线圈中心与骨延迟愈合部位对准,并彼此相对平行。２两线圈固定后,将线圈插入仪器前面板输出插座中,开启电源开关…     

NGF 与Neuritin 在脑外伤伴四肢骨折病人血清中的表达及意义

目的:通过检测脑外伤患者、脑外伤合并骨折患者、骨折患者及正常人外周血中NGF,neuritin不同时间段的表达,根据其含量的变化,判断与骨折愈合速度的相关性,寻找骨折愈合的关键因子。方法:收集单纯脑外伤、单纯骨折患者各80例、脑外伤合并骨折患者60例、健康体检人群20例。选取外伤后3天、10天、2周抽取所有实验对象的静脉血,应用ELISA技术测定标本中NGF与Neuritin的含量。结果:损伤后每个时间段里,患者血清中NGF、neuritin含量有不同程度升高,均高于正常对照组,其中又以脑外伤合并骨折组最高。血清NGF在骨折合并脑外伤组伤后第3天含量明显升高,为(0.86±0.21),伤后10天为(1.47±0.29),14天为(2.0 7±0.21),脑外伤合并四肢骨折组neuritin血清含量在伤后第3天略有升高为(83.47±18.85),10天(108.50±31.65),2周(91.86±21.12).脑外伤合并骨折病人血清NGF、neuritin表达明显高于其他对照组,差别均有统计学意义(P<0.05)。结论:脑外伤合并骨折病人血清NGF、neuritin表达明显高于其他对照组,说明与骨折愈合有着密切的相关性,两种因子可能在骨折愈合修复过程中共同起作用,从而,推测可能是脑外伤后骨折愈合加速的重要因素。     

骨折愈合过程中生长因子的研究进展

目的:骨折愈合是一个复杂的过程受到机体多层面、多途径调节,而在这个过程中有许多生长因子的参与.方法:通过对有关生长因子文章的筛查,选取近年发表的针对性和权威性的文章将其行回顾性分析.结果:骨折愈合过程中有多种细胞因子参与并促进骨折愈合.结论:随着分子生物学的发展,特别是生长因子及其受体的发现,骨折愈合机制的研究也进入分子水平.目前,生长因子在骨折愈合中的骨发生、诱导、修复和骨量保持方面发挥着重要而关键的作用.因此,进一步明确作用机制,尤其是各细胞因子之间的相互作用是今后要研究的问题.     

生长因子在骨折愈合过程中作用的研究进展

骨折愈合是一个复杂的病理生理过程,涉及多种细胞和生长因子的协同作用。随着分子生物学和基因工程的发展,生长因子在骨折愈合过程中的基础研究和临床应用取得了较大的进展。本文就转化生长因子β．碱性成纤维细胞生长因子、血小板衍生生长因子、表皮生长因子、神经生长因子等五种生长因子在骨折愈合过程中的作用及近年来的研究进展作一综述,并分析五种生长因于在法医学中的应用前景。     

L-羟脯氨酸用于小鼠骨折愈合的实验研究

让骨折的小白鼠饮用L 羟脯氨酸水溶液 ,然后通过X线拍片观察其骨折的愈合情况 ,并与对照组进行比较 ,结果表明 :L 羟脯氨酸有促进骨折愈合的作用 ,而且安全、无毒。     

补锌对兔实验性颧骨骨折愈合影响的生物力学研究

通过对１８只实验性颧骨骨折新西兰兔在骨折愈合过程中采用补锌和未补锌两种方法,来比较研究补锌对骨折部位的生物力学影响,进而阐明锌对骨折愈合的作用。     

神经生长因子

神经生长因子是一类能促进神经生长的多肽,近年来的研究表明它在非神经系统及肿瘤的发生中也有重要作用。本文综述了神经生长因子的结构、生物合成、作用机制及生理、病理作用等方面的研究进展。     

促进骨折愈合的治疗策略及机制研究进展

骨折愈合和修复是一个复杂的过程,包括膜内成骨和软骨内成骨两种方式.绝大多数骨折患者经治疗后可以愈合,但由于术后感染、患者自身成骨能力差等原因,仍有5％～10％的骨不连患者无法愈合进而导致截肢等风险.目前骨不连的治疗包括自体骨移植、使用重组生长因子BMP等策略,但尚无获得批准的治疗药物,因此还需对骨折愈合过程中的生物学机...     

Nerve growth factor

Nerve growth factor (NGF) is widely recognized as a target-derived factor responsible for the survival and maintenance of the phenotype of specific subsets of peripheral neurons and basal forebrain cholinergic nuclei during development and maturation. Other NGF-responsive cells are now known to belong to the hemopoietic-immune system and to populations in the brain involved in neuroendocrine functions. The concentration of NGF is elevated in a number of inflammatory and autoimmune states in conjunction with increased accumulation of mast cells. Mast cells and NGF appear to be involved in neuroimmune interactions and tissue inflammation. Mast cells themselves are capable of producing and responding to NGF, suggesting that alterations in mast cell behavior may trigger maladaptive neuroimmune tissue responses, including those of an autoimmune nature. Moreover, NGF exerts a modulatory role on sensory nociceptive nerve physiology in the adult, and appears to correlate with hyperalgesic phenomena occurring in tissue inflammation. NGF can thus be viewed as a multifactorial modulator of neuroimmune-endocrine functions.     

Biglycan modulates angiogenesis and bone formation during fracture healing

Matrix proteoglycans such as biglycan (Bgn) dominate skeletal tissue and yet its exact role in regulating bone function is still unclear. In this paper we describe the potential role of (Bgn) in the fracture healing process. We hypothesized that Bgn could regulate fracture healing because of previous work showing that it can affect normal bone formation. To test this hypothesis, we created fractures in femurs of 6-week-old male wild type (WT or Bgn+/0) and Bgn-deficient (Bgn-KO or Bgn-/0) mice using a custom-made standardized fracture device, and analyzed the process of healing over time. The formation of a callus around the fracture site was observed at both 7 and 14 days post-fracture in WT and Bgn-deficient mice and immunohistochemistry revealed that Bgn was highly expressed in the fracture callus of WT mice, localizing within woven bone and cartilage. Micro-computed tomography (μCT) analysis of the region surrounding the fracture line showed that the Bgn-deficient mice had a smaller callus than WT mice. Histology of the same region also showed the presence of less cartilage and woven bone in the Bgn-deficient mice compared to WT mice. Picrosirius red staining of the callus visualized under polarized light showed that there was less fibrillar collagen in the Bgn-deficient mice, a finding confirmed by immunohistochemistry using antibodies to type I collagen. Interestingly, real time RT-PCR of the callus at 7 days post-fracture showed a significant decrease in relative vascular endothelial growth factor A (VEGF) gene expression by Bgn-deficient mice as compared to WT. Moreover, VEGF was shown to bind directly to Bgn through a solid-phase binding assay. The inability of Bgn to directly enhance VEGF-induced signaling suggests that Bgn has a unique role in regulating vessel formation, potentially related to VEGF storage or stabilization in the matrix. Taken together, these results suggest that Bgn has a regulatory role in the process of bone formation during fracture healing, and further, that reduced angiogenesis could be the molecular basis.     

Molecular signaling in bone fracture healing and distraction osteogenesis

The process of fracture healing has been described in detail in many histological studies. Recent work has focused on the mechanisms by which growth and differentiation factors regulate the fracture healing process. Rapid progress in skeletal cellular and molecular biology has led to the identification of many signaling molecules associated with the formation of skeletal tissues, including members of the transforming growth factor-beta (TGF-beta) superfamily and the insulin-like growth factor (IGF) family. Increasing evidence indicates that they are critical regulators of cellular proliferation, differentiation, extracellular matrix biosynthesis and mineralization. Limb lengthening procedure (distraction osteogenesis) is a relevant model to investigate the in vivo correlation between mechanical stimulation and biological responses as the callus is stretched by a proper rate and rhythm of mechanical strain. This model also provides additional insights into the molecular and cellular events during bone fracture repair. TGF-beta 1 was significantly increased in both the distracted callus and the fracture callus. The increased level of TGF-beta 1, together with a low concentration of calcium and an enhanced level of collagen synthesis, was maintained in the distracted callus as long as mechanical strain was applied. Less mineralization is also associated with a low level of osteocalcin production. These observations provide further insights into the molecular basis for the cellular events during distraction osteogenesis.     

Nerve growth factor and pancreatic APUD cells

Pancreatic endocrine cells have been considered APUD cells and been thought to be of neural crest origin. Neonatal rats were passively immunized with nerve growth factor antiserum and the development of neural crest derived superior cervical ganglia was markedly inhibited. The pancreatic content of glucagon, insulin, and somatostatin was unaffected, suggesting that pancreatic A,B, and D cells are under different developmental control than are cells of known neural crest origin.     

Nerve growth factor and neuronal cell death

The regulation of neuronal cell death by the neuronotrophic factor, nerve growth factor (NGF), has been described during neural development and following injury to the nervous system. Also, reduced NGF activity has been reported for the aged NGF-responsive neurons of the sympathetic nervous system and cholinergic regions of the central nervous system (CNS) in aged rodents and man. Although there is some knowledge of the molecular structure of the NGF and its receptor, less is known as to the mechanism of action of NGF. Here, a possible role for NGF in the regulation of oxidant--antioxidant balance is discussed as part of a molecular explanation for the known effects of NGF on neuronal survival during development, after injury, and in the aged CNS.