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1.
利用内部骨重建理论和有限元法计算骨密度的变化   总被引:2,自引:0,他引:2  
采用内部骨重建理论和有限元算法相结合的方法,探讨了外载荷对骨重建的作用。从一张骨的X线断层片提取出边界数据.处理后建立骨的二维模型;应用有限元软件Ansys进行计算.得到骨重建后的结果。计算结果表明内部重建理论预测结果与骨的实际结构有相当程度的一致性,证明了此种方法的可行性。  相似文献   

2.
骨微损伤能启动骨重建,骨重建障碍而导致微损伤积累可引发骨折。扫描电镜、同步加速器射线μ-CT和高分辨磁共振显像是研究骨微损伤的新方法,骨理化构成和年龄对微损伤发生和发展有重要影响,骨细胞在微损伤修复中起重要作用,骨微损伤研究有利于代谢性骨病防治。  相似文献   

3.
骨骼的生长、发育和维持都与骨组织重建有着密切的关系,随着生物力学、组织工程、细胞生物学等学科的迅速发展,骨科相关疾病及其治疗的研究形成了多学科交叉、渗透的趋势,力学生物学已经成为研究骨重建的重要方法。本文对近年来骨重建的力学生物学相关研究工作进行整理和总结,希望为骨重建的研究、骨组织工程修复骨缺损和临床治疗相关骨科疾病的诊治提供理论基础。  相似文献   

4.
类风湿性关节炎(rheumatoid arthritis,RA)是一种以慢性侵蚀性关节炎为特征的全身性自身免疫病,可引起关节疼痛、肿胀、僵硬,永久性关节破坏,严重损害时可以导致残疾和畸形。骨破坏是类风湿性关节炎疾病进程中造成患者功能障碍等诸多临床问题的重要原因,骨重建(bone remodeling)过程的失调加重了类风湿性关节炎的损伤。在骨重建过程中,两条重要通路在成骨细胞的增殖分化以及骨和软骨形成与损伤修复的过程中起着十分重要的作用,即Wnt信号通路及骨形态发生蛋白(bone morphogenetic proteins,BMPs)信号通路。本文拟对正常状态下骨重建的两条重要通路和其在RA中的异常改变对骨重建的影响作一综述。  相似文献   

5.
跟骨重建钢板加植骨治疗跟骨关节内骨折   总被引:1,自引:1,他引:0  
袁瑞斌 《局解手术学杂志》2010,19(2):F0002-F0002
跟骨骨折是足部的常见损伤,伤者以青壮年居多。跟骨骨折占所有骨折的1%-2%,严重损伤易遗留伤残。2005年至2008年我科采用跟骨重建钢板加植骨治疗跟骨关节内骨折16例,疗效满意。现报告如下。  相似文献   

6.
Notch信号通路在胚胎发育、神经系统、血管系统、内分泌系统及肿瘤等领域具有广泛的影响。近年来的研究表明,Notch对于骨组织代谢尤其是骨重建有着重要的调控作用,而骨重建的调节紊乱和骨质疏松、骨关节炎等疾病的进展密切相关。Notch信号通路可以通过调控骨组织不同细胞的功能从而影响骨重建过程,但其在不同细胞中具体的参与方式仍然未知。综述近年来Notch信号通路在骨重建中的作用研究进展。  相似文献   

7.
疲劳性骨膜炎对兔胫骨重建的影响   总被引:2,自引:0,他引:2  
目的 研究疲劳性骨膜炎对骨重建的影响。方法 通过大强度运动训练建立免胫骨疲劳性骨膜炎模型,采用组织学、放射学和胫骨横截面几何形态学方法测量骨的横截面积。结果 大强度运动训练引起胫骨疲劳性骨膜炎后胫骨的横截面积明显加大。结论 运动训练引起胫骨疲劳性骨膜炎可能是骨组织对大强度运动训练的一种适应性重建,横截面积加大增强骨的力学特性来达到功能适应的目的。  相似文献   

8.
我们在分析目前现有的骨再造理论的基础上,根据Thomas Brown的实验结果,结合有限元方法,提出以主应力作为力学激励,决定骨功能性适应重建的形态或密度变化,建立了基于主应力的骨重建方程,并通过对正畸中倾斜移动进行模拟,结果能定性地反映临床观察中牙槽骨的重建现象.  相似文献   

9.
目的建立基于应力状态的细胞分子水平骨重建力生物学模型。方法从工程角度分析骨重建过程和力学激励,吸纳力学强度设计理论思想,选取相当应力作为力学激励,基于应力状态选取合适的力学激励计算公式,提出基于应力状态的细胞分子水平骨重建力生物学模型;应用模型进行口腔临床正畸牙槽骨的模拟预测。结果张力区孔隙度降低,骨量增加;压力区孔隙度增加,骨量减少,与牙槽骨特性一致。结论基于应力状态的细胞分子水平骨重建力生物学模型考虑应力状态对骨组织失效形式的影响,体现骨重建过程是力学激励下细胞水平的自优化强度设计,有助于在细胞分子水平探讨应力状态对骨重建的影响,是骨重建理论的补充和完善,可为口腔正畸的治疗提供理论指导。  相似文献   

10.
目的 采用Wolff骨重建理论分析全髋关节置换(total hip arthroplasty,THA)对股骨近端骨重建进程的影响。方法 根据骨重建控制方程,利用Python语言编写骨重建程序。在ABAQUS软件中分别建立术前股骨模型与术后股骨及假体有限元模型。对比THA手术前后骨重建进程,分析假体植入对THA术后中远期股骨力学性能的影响。结果 假体植入后,股骨近端应力持续降低,受力点由股骨头转移到假体,出现明显的应力遮挡现象。应力遮挡区域内骨丢失现象严重。股骨干皮质骨变薄,应力遮挡有所缓解。假体底端内侧受挤压,应力显著高于外侧,此处骨质分布不均。结论 THA术后股骨近端内侧出现明显的应力遮挡,导致骨丢失,造成假体松动;假体底端两侧应力水平存在差异,引起骨质分布不均,导致假体与股骨配合不紧密,造成术后患者大腿中段的疼痛。  相似文献   

11.
The original concept of asthma being primarily a disease of airways smooth muscle drove the development of bronchodilator drugs. However when it was realised that airway inflammation underpinned the disordered airway function, this gave way to the development of controller therapies such as inhaled cromones and corticosteroids. More recently the discovery of complex interconnecting cytokine and chemokine networks has stimulated the development of biologics with varying success. With the recognition that airway wall "remodelling" is present early in asthma inception and is in part driven by aberrant epithelial-mesenchymal communication both genetic and environmental factors beyond allergen exposure such as virus infection and air pollution are being seen as being increasingly important not only in asthma exacerbations but in the origins of asthma and its evolution into different sub-phenotypes. This brings us round full circle to once again considering that the origins of asthma lie in defects in the formed elements of the airway; the epithelium, smooth muscle, and vasculature. Over the last 25 years Professor You Young Kim has engaged in the exciting discovery science of allergy and asthma and has made an enormous contribution in bringing Korea to the forefront of disease management and research, a position that both he and his colleagues can justly be proud of.  相似文献   

12.
骨能够响应外部力学载荷,在特定位置生成或吸收骨组织不但可以提高骨的力学功能效率,而且还能及时修复日常载荷下骨内产生的微裂纹,以防止骨折并延长骨骼寿命,这称为骨功能适应性。与传统实验研究方法相比,计算机数值模拟具有可控性、可行性和可预测性等优势。鉴于骨功能适应性机制研究有重要的力学生物学理论意义和骨科临床的实用价值,本文对近年来国内外骨功能适应性数值模拟的新进展作一综述。  相似文献   

13.
This study was aimed at determining impact of an empowerment-based psychosocial intervention on the patients' quality of life and glycemic control as compared to patients in standard care. Consecutively recruited type 2 diabetic patients, scheduled for their regular medical check-ups, were individually acquainted with empowerment-based principles and invited to participate in an empowering psychosocial course. The response rate was 35% giving a number of 73 patients who were treated in eight separate groups. The treated patients reported their quality of life to be improved after the course regarding its psychological and social aspects. Their glycemic control also improved and remained so after 3- and 6-month follow-up periods, still being in a category of poor control. Empowerment-based psychosocial intervention in type 2 diabetic patients was shown to favourably affect their quality of life and to improve their metabolic control, the latter in a modest degree. Better educated patients believing in internal health control and efficacy of diabetes treatment seemed to benefit the most. Further research is needed in order to highlight individual preferences for different educational approaches, as well as social and cultural factors affecting them.  相似文献   

14.
Standard teaching about defense mechanisms generally focuses on definitions, which do not readily aid the clinician in identifying defenses whenever individuals use them. This report demonstrates a process by which the clinician can identify when a defense is used, which ones are likely being used, and with what aim. Clinicians first notice that a defense may be operating whenever the other individual presents with anomalies in the expression of affect, behavior, speech, or its content. Some of these anomalies are described. Next, to identify the specific defense or general level of defensive functioning used, the clinician must identify the specific function of the defense in context using a process of guided clinical inference. This report examines 2 verbatim examples from recorded interviews of one case to demonstrate this process. The examples present a microcosm of clinical concerns that have a surprising relationship to the individual's course and prognosis.  相似文献   

15.
There is increasing interest about the possible involvement of the sympathetic nervous system (SNS) in initiation and maintenance of chronic muscle pain syndromes of different aetiology. Epidemiological data show that stresses of different nature, e.g. work-related, psychosocial, etc., typically characterised by SNS activation, may be a co-factor in the development of the pain syndrome and/or negatively affect its time course. In spite of their clear traumatic origin, whiplash associated disorders (WAD) appear to share many common features with other chronic pain syndromes affecting the musculo-skeletal system. These features do not only include symptoms, like type of pain or sensory and motor dysfunctions, but possibly also some of the pathophysiological mechanisms that may concur to establish the chronic pain syndrome. This review focuses on WAD, particular emphasis being devoted to sensorimotor symptoms, and on the actions exerted by the sympathetic system at muscle level. Besides its well-known action on muscle blood flow, the SNS is able to affect the contractility of muscle fibres, to modulate the proprioceptive information arising from the muscle spindle receptors and, under certain conditions, to modulate nociceptive information. Furthermore, the activity of the SNS itself is in turn affected by muscle conditions, such as its current state of activity, fatigue and pain signals originating in the muscle. The possible involvement of the SNS in the development of WAD is discussed in light of the several positive feedback loops in which it is implicated.  相似文献   

16.
PURPOSE OF REVIEW: Irreversible airflow limitation develops in some patients with asthma and is related to poorer prognosis. This paper reviews recent literature on natural course, risk factors, and potential mechanisms of persistent airflow limitation in asthma. RECENT FINDINGS: The natural course of persistent airflow limitation in asthma is poorly known, but reduced lung function at disease onset and an increased rate of decline during adult life contribute to its development. Risk factors for progressive irreversible airway obstruction in asthma include adult onset, frequent exacerbations, smoking, occupational exposure, ongoing eosinophilic airway inflammation and airway hyperresponsiveness. Polymorphisms of the ADAM33 gene predict excess decline in lung function, in asthma as well as at population level. It is still not clear how different components of airway remodeling affect lung function in asthma. Airway epithelium and airway smooth muscle seem to be highly important, but the interrelationship between persistent airflow limitation, airway inflammation, remodeling and airway hyperresponsiveness has not been clearly defined. SUMMARY: Whereas several factors have been implicated as being important in the development of fixed airway obstruction in asthma, we are just beginning to explore the different components of airway remodeling and their relevance, deleterious or beneficial, to clinical outcome.  相似文献   

17.
Association analysis has suggested that common sequence variants of genes that affect monoamine function can affect substance use and abuse. Demonstration of these associations has been inconsistent because of limited sample sizes and phenotype definition. Drawing on the life course perspective, we predicted a stronger association between the polymorphisms in 5HTT, DAT1, DRD4, DRD2, and MAOA and alcohol consumption in young adulthood than adolescence. This analysis tested for the gene-lifecourse interaction for the frequency of alcohol consumption in a nationally representative non-alcohol-dependent sample of 2,466 individuals that were visited during adolescence and young adulthood for four times between 1994 and 2002. All five genes are significantly associated with the frequency of alcohol consumption, with the genotype effects ranging 7%-20% of the mean score of alcohol consumption and their P values being 0.014, 0.0003, 0.003, 0.007, 0.005, and 0.003, respectively. The association is only observed in the life stage of young adulthood and not in adolescence. This analysis has demonstrated the potential usefulness of the life course perspective in genetic studies of human behaviors such as alcohol consumption.  相似文献   

18.
Spontaneous medastinal emphysema, as a complication of acute severe asthma, is an uncommon entity. It usually runs a benign course and resolves spontaneously without any surgical intervention. Recognition of this complication is critical, as it has to be differentiated from other life threatening ones including oesophageal rupture, Boerhave’s syndrome, acute coronary syndrome and pulmonary embolism. This case is being presented to emphasize its recognition in the differential diagnosis of complications arising from acute severe asthma and to present its management strategy in detail.  相似文献   

19.
Bone homeostasis depends on the resorption of bones by osteoclasts and formation of bones by the osteoblasts. Imbalance of this tightly coupled process can cause diseases such as osteoporosis. Thus, the mechanisms that regulate communication between osteoclasts and osteoblasts are critical to bone cell biology. It has been shown that osteoblasts and osteoclasts can communicate with each other through direct cell–cell contact, cytokines, and extracellular matrix interaction. Osteoblasts can affect osteoclast formation, differentiation, or apoptosis through several pathways, such as OPG/RANKL/RANK, RANKL/LGR4/RANK, Ephrin2/ephB4, and Fas/FasL pathways. Conversely, osteoclasts also influence formation of bones by osteoblasts via the d2 isoform of the vacuolar (H+) ATPase (v-ATPase) V0 domain (Atp6v0d2), complement component 3a, semaphorin 4D or microRNAs. In addition, cytokines released from the resorbed bone matrix, such as TGF-β and IGF-1, also affect the activity of osteoblasts. Drugs could be developed by enhancing or restricting some of these interactions. Several reviews have been performed on the osteoblast–osteoclast communication. However, few reviews have shown the research advances in the recent years. In this review, we summarized the current knowledge on osteoblast–osteoclast communication.  相似文献   

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