载荷诱导骨生长的力学细胞生物学机制

骨骼的结构和功能在很大程度上依赖于其所处的力学环境,这一观点已被广为接受．自从Ｗｏｌｆｆ提出其著名的骨转换定律以来,骨生长与载荷间的关系一直是生物力学中一个重要的问题．大量的动物实验均证明二者之间存在明确的关联．然而,载荷诱导骨生长的力学细胞生物学（ｍｅｃｈａｎｏｃｙ－ｔｏｂｉｏｌｏｇｙ）机制仍很不清楚．十余年来体外培养骨骼细胞加载的研究为应力（应变）诱导骨生长提供了一个微观理论框架．目前认为,载荷诱导骨生长的过程可分为四个环节,即：力学耦联、生物化学耦联、胞间信号转导和效应细胞反应．详细阐述了这几个环节,并就今后的研究方向作一讨论．     

The Effect of Physical Activity on the Properties of Bone Tissue

The effect of sports training or lack of physical activity on the properties of bone tissue is investigated. People with normal physical activity, sportsmen, and hypodynamic persons are tested. Ultrasound as a safe and noninvasive method is used. In normal activity and after short-time sports training or bed rest, the maximum ultrasound velocity is observed in the middle part of the tibia diaphysis because this region has the highest bending moment. Long-time sports training (more than seven years) in basketball and freestyle skiing alters the distribution of ultrasound velocity along the tibia: the maximum velocity is found in the distal diaphysis of the tibia due to the existence of high mechanical stresses in this region caused by the intense external impact loads and the calf muscle contraction. The maximum velocity for rowers is in the middle diaphysis or in the region between the proximal and middle diaphysis, since high impact loads are not characteristic of their foot joints. Long-time hypodynamia weakens the distal diaphysis of the tibia due to the lack of naturally occuring high stresses in this part of the bone.     

含液体松质骨的压缩实验分析

在本文中,假设不含液体松质骨为红弹性体,以及松质骨固液两相结构特性,建立了含液体松质骨的单向压缩本构方程,其形式与三参量线粘弹性体的本构方程相同。并通过拟合实验结果,得到本构方程中有关参数的值。     

皮下组织对羟基磷灰石力学性质的影响

将羟基磷灰石试样植入大白鼠的皮下组织20\,d后取出,然后采用数字图像 相关方法研究纤维组织对人造羟基磷灰石的力学性质的影响. 测量了两种试样：植入大白鼠 皮下组织的羟基磷灰石试样和未经植入的羟基磷灰石试样. 得到了羟基磷灰石完整的应力- 应变曲线;还测量了压缩极限应力. 实验结果表明羟基磷灰石的应力-应变曲线在断裂前呈良 好的线性关系;皮下纤维组织能使羟基磷灰石材料的弹性模量和强度增加, 20\,d后使羟基磷 灰石的弹性模量增加了29.06{\%}, 压缩极限应力增加了28.71%.     

Effects of time delays in a mathematical bone model

In this paper we propose a mathematical model of bone remodeling with time delays of both osteoclast-derived paracrine signaling of tumor and tumor-derived paracrine signaling of osteoclast. The effects of time delays on the growth of tumor cells and bone system are studied in multiple myeloma-induced bone disease. In the case of small osteoclast-derived paracrine signaling, it is found that the growth of tumor cells slows down, the oscillation period of the ratio of osteoclasts to osteoblasts is extended with increasing time delay, and there is a competition between the delay and osteoclast-derived paracrine signaling. In the case of large tumor-derived paracrine signaling, the tumor-derived paracrine signaling can induce a more significant decline in tumor growth for long time delay, and thus slowing down the progression of bone disease. There is an optimal coupling between the tumor-derived paracrine signaling of osteoclasts and time delay during the progressions of bone diseases, which suppresses the tumor growth and the regression of bone disease.     

复合结构组织工程化人工骨的金属支架结构设计研究?

支架结构设计是组织工程化人工骨设计的重要内容之一,本文对金属与陶瓷材料构成的复合结构人工骨中金属支架的设计进行了研究。通过对髋关节置换后假体与股骨之间力的传递规律进行数值模拟研究,采用分截面分析、网格密度逐渐减小的设计方法,对复合结构人工骨中的金属支架结构进行了设计。通过对6种不同网格密度金属支架的受力情况进行对比分析,设计出了力学特性符合股骨受力规律的金属支架结构。     

显微红外光谱法研究豚鼠膝关节软骨下骨的增龄性改变

应用显微FTIR技术原位分析雌性Hartley豚鼠随月龄增加胫骨关节软骨下骨的化学变化。红外光谱测定三种月龄(1月、2月和3月)豚鼠软骨下3个不同吸收颜色的骨小梁区(a,b,c)和中央骨髓区(d)。结果显示：(1)随月龄增加,骨小梁总面积增加,与正常骨小梁谱图相似的a区减少,d区波形有逐渐向a区发展的趋势。(2)2月龄和3月龄的b和c区AmideⅢ红移以c区红移显著并且变成肩峰,代表核酸和多糖的吸收峰峰强是a区的7倍。(3)三种月龄的c区均出现了β型糖苷键吸收峰。(4)I_AmideⅠ/I_AmideⅡ在2月b区最大,3月各区最小,I_AmideⅢ/I_AmideⅡ 在 2月、3月由a到c依次降低,I_νsPO-₂/I_AmideⅡ在2月、3月的b和c区较相应a区高7倍以上。结果符合骨关节炎不同阶段软骨下骨的组织结构及化学组成的变化规律。初步研究表明,显微光谱成像技术结合FTIR可原位分析不同区域的软骨下骨小梁和骨髓的分子组成,为骨关节炎软骨下骨组织病理学的分子水平研究提供了可靠信息。     

骨的微量元素代谢

雌激素可通过影响骨骼细胞的新陈代谢而促进微量元素在骨骼中的储存,微量元素代谢与骨质疏松的形成发展有密切关系。近年来不少学者对一些必需微量元素如硼(5B)、氟(9F)、钒(23V)、锰(25Mn)、铁(26Fe)、钴(27Co)、铜(29Cu)、锌(30Zn)、硒(34Se)、锶(38Sr)等和一些非必需微量元素如铝(13Al)、镓(31Ga)、锗(32Ge)、镉(48Cd)、铅(82Pb)等与骨质疏松关系的研究取得了令人瞩目的成果。     

Vitamin D Fortification of Consumption Cow’s Milk: Health,Nutritional and Technological Aspects. A Multidisciplinary Lecture of the Recent Scientific Evidence

Vitamin D is essential in assuring bone health at all stages of life, but its non-skeletal effects are also essential: This vitamin impacts the physiology of the immune system, skeletal muscles and adipose tissue, glucose metabolism, skin, cardiovascular and reproductive systems, neuro-cognitive functions and cell division. The incidence of vitamin D deficiency is widespread worldwide, at any age, in young and healthy subjects, as well as in pregnant women and the elderly population, due to several factors, including inadequate sunlight exposure, skin pigmentation and coverage, adiposity, lifestyle and low dietary intakes. To overcome this problem, the fortification of foods that are consumed on a daily basis, such as milk, is strongly advisable. This opinion paper aims to discuss, in a multidisciplinary way, the current evidence supporting the importance of vitamin D in health and disease and the role of milk as an optimal carrier of this vitamin, to promote adequate intakes, highlighting its unique physico-chemical characteristics linked to both fat globule membrane and casein micelle structure. Moreover, it addresses the impact of industrial processing and storage of consumption milk on the stability of these structures, thus in determining vitamin D bioavailability and the achievement of adequate intakes.     

聚类分析在虎骨代用品研究中的应用

本文通过聚类分析的方法利用虎和某些动物的腿骨和椎骨骨胶中１７种氨基酸含量的数据，对虎骨和这些动物骨进行分类，以研究虎骨与其它动物骨的相似性，为挑选虎骨的代用品提供科学的依据。文中的分析依赖《多元统计分析实用程序》软件包，并同时采用了程序中动态聚类分析和系统聚类分析中最短距离和类平均几种聚类方法进行。由这些方法得到的大体相近的一些结论，达到了本文分析的目的。