The Theory of Bio-Medical Knowledge Integration（V）——The meta-dimensions and their combinations of the General Linkage/Modifiers of SNOMED

There are nowadays numerous researches and devel- opments at knowledge or clinical levels in Medical Infor- matics such as the terminologies, taxologies, ontologies, etc and they have won and will further win much or more admirations from these fields. Bu…     

Characteristics of Radioimmunoassays for the α- and β-Subunits of Human Luteinizing Hormone

Abstract

The binding characteristics and specificities of the National Hormone and Pituitary Program (NHPP) kits for the radioimmunoassay of the alpha- and beta-subunits of human luteinizing hormone (hLH-α and hLH-β) were studied, as well as the specificities of the anti-hLH and anti-human follicle stimulating hormone (anti-hFSH) antisera distributed by the same organization. The affinity constants of the anti-hLH-α and anti-hLH-β antisera were calculated at 157 ± 8.4 nM^?1 and 109 ± 7.4 nM^?1, respectively. Both antisera were highly specific with regard to the other subunit. However, in the homologous hLH-α RIA, native hLH cross-reacted at 21.9%, hFSH at 17.5% and hTSH at 7.9%. The alpha-subunit of the human chorionic gonadotropin, hCG-α, was equipotent with the hLH-α standard in this assay. In the homologous hLH-β RIA, hLH showed a cross-reactivity of 14.7% while the cross-reactivities of hCG-β, hFSH and hTSH were 3.5%, 1.2% and 0.6%, respectively. The anti-hFSH antiserum was highly specific, while the anti-hLH antiserum showed non parallel competition curves. With this knowledge of the specificity of each antiserum, corrections can be properly made for the assays of hLH, hLH-α and hLH-β while the hFSH RIA can be used without correction for the presence of the three other components.     

Human IgG1 Cγ1 Domain Is Crucial for the Bioactivity of the Engineered Anti-CD20 Antibodies

In this study, we discussed the necessity of human IgG1 Cγ1 domain for recombinant antibody using computeraided homology modeling method and experimental studies. The heavy （VH） and light （VL） chain variable regions of 1-28, a murine IgM-type anti-CD20 mAb, were ligated by linker peptide （Gly4Ser）3 to form the single-chain Fv fragment （scFv）. Then, the engineered antibody （LH1-3） was generated by fusing scFv with the entire IgG1 heavy constant regions. The 3-D structure of LH1-3 was modeled using computer-aided homology modeling method and the binding activity of LH1-3 was evaluated theoretically. Compared to the 3-D structure of the Fv fragment of the parent antibody, the conformation of the active pocket of LH1-3 was remained because of the rigid support of Cγ1. Further experimental results of flow cytometry showed that the engineered anti-CD20 antibody possessed specifically binding activity to CD20-expressing target cells. The anti-CD20 antibody fragments could also mediate complement-dependent cytotoxicity （CDC） of human B-lymphoid cell lines. Our study highlights some interests and advantages of a methodology based on the homology modeling and analysis of molecular structural properties.     

The Effect of N-Nitrosodimethylamine on TRAIL and DR5 Expression in Human Neutrophils—Preliminary Study

The intracellular mechanisms of NDMA-induced apoptosis of neutrophils have not yet been fully understood. The aim of this study was to explain whether the TRAIL/DR5 system is implicated in NDMA-induced apoptosis of human neutrophils. The expression of TRAIL and DR5 was examined, as well as the secretion of sTRAIL and sDR5 by human neutrophils treated with NDMA confronted with intensity apoptosis of these cells. For comparative purposes similar examinations in autologous peripheral blood mononuclear cells (PBMC) were performed. Decreased expression and secretion of TRAIL and increased expression and secretion of DR5 associated with increased intensity of apoptosis of polymorphonuclear leukocytes (PMNs) suggest that NDMA-induced apoptosis in these cells may be depend on TRAIL/DR5 system. Autologous PBMCs no exerted that changes in the expression and secretion of TRAIL as well as in the intensity of apoptosis. However, the expression and secretion of DR5 by PBMCs were similar to those by PMNs. Differences above suggest that PMNs are more sensitive to unfavorable action of NDMA than PBMCs.     

A Unified Method for Calculating the Center of Pressure during Wheelchair Propulsion

The measurement of the center of pressure (COP) has been and continues to be a successful tool for gait analysis. The definition of a similar COP for wheelchair propulsion, however, is not straightforward. Previously, a COP definition similar to that used in force plate analysis had been proposed. Unfortunately, this solution has the disadvantage of requiring a separate COP definition for each plane of analysis. A definition of the generalized center of pressure (GCOP) which is consistent in all planes of analysis is derived here. This definition is based on the placement of a force-moment system, equivalent to the force-moment system at the hub, on a line in space where the moment vector (wrench moment) is parallel to the force vector. The parallel force-moment system is then intersected with three planes defined by anatomical landmarks on the hand. Data were collected using eight subjects at propulsion speeds of 1.34 m/s and 2.24 m/s (1.34 m/s only for subject 1, 0.894 m/s and 1.79 m/s for subject 8). Each subject propelled a wheelchair instrumented with a SMART^Wheel. A PEAK 5 video system was used to determine the position of anatomical markers attached to each subjects upper extremity. The GCOP in the transverse plane of the wrist formed clusters for all subjects except subject 2 at 1.34 m/s. The clustering of the GCOP indicates that the line of action for the force applied by the hand is approximately perpendicular to the transverse plane through the wrist. When comparing the magnitude of the moment vector part of the wrench with the moment of the force vector of the wrench about the hub, the wrench moment is approximately an order of magnitude smaller. This indicates that the role of the wrist for wheelchair propulsion is primarily to stabilize the force applied by the arm and shoulder. © 1998 Biomedical Engineering Society. PAC98: 8745Dr, 8710+e     

血清基质金属蛋白酶活性与动脉粥样硬化斑块稳定性的实验观察

目的观察血清MMP-2、MMP-9在不同时期的兔动脉粥样硬化动物模型中的变化,研究其影响因素及与斑块稳定性的关系。方法将30只长耳白兔随机分为3组:普通饮食组(n=10),高脂饮食组(n=10),球囊损伤 高脂饮食组(n=10),3个月后以中国斑点蝰蛇毒和组胺触发使斑块破裂。其间监测血脂情况,并行血清MMP-2、MMP-9检测。动物处死后查找动脉硬化斑块行病理检测。结果普通饮食组实验中各检测项目均无明显差异。高脂饮食及球囊损伤 高脂饮食组一个月后血脂明显升高。药物触发后高脂饮食组血清MMP-9活性明显增加,球囊损伤 高脂饮食组血清MMP-2、MMP-9活性均明显增加。结论在兔动脉粥样硬化的动物模型中,斑块处于不稳定状态时血清MMP-9活性明显增加,而MMP-2的活性升高可能与内皮机械损伤有关。     

Biomechanics: Cell Research and Applications for the Next Decade

With the recent revolution in Molecular Biology and the deciphering of the Human Genome, understanding of the building blocks that comprise living systems has advanced rapidly. We have yet to understand, however, how the physical forces that animate life affect the synthesis, folding, assembly, and function of these molecular building blocks. We are equally uncertain as to how these building blocks interact dynamically to create coupled regulatory networks from which integrative biological behaviors emerge. Here we review recent advances in the field of biomechanics at the cellular and molecular levels, and set forth challenges confronting the field. Living systems work and move as multi-molecular collectives, and in order to understand key aspects of health and disease we must first be able to explain how physical forces and mechanical structures contribute to the active material properties of living cells and tissues, as well as how these forces impact information processing and cellular decision making. Such insights will no doubt inform basic biology and rational engineering of effective new approaches to clinical therapy. This is a white-paper developed by the Cell Mechanics working group of the US National Committee on Biomechanics.     

建立基于广义Hamilton及Lie群理论的人体骨肌系统动力学方程

目的　建立一种基于广义Arial及Arial群理论的人体骨肌系统动力学建模方法。方法　首先,定义了人体骨肌系统的广义坐标,建立了人体骨肌系统Arial群位形流形;其次,在广义Arial动力学体系下建立了人体骨肌系统的动力学模型;最后,研究了该动力学模型的计算方法。结果　给出了基于广义Arial及其群理论的人体骨肌系统动力学方程,并以一个举重动作为例进行了骨肌系统动力学算法分析。结论　所提出的人体骨肌系统动力学方程能够有效真实地对人体骨肌系统进行动力学描述,为人体骨肌系统动力学分析提供了一种新方法。     

The Local Matrix Distribution and the Functional Development of Tissue Engineered Cartilage,a Finite Element Study

Assessment of the functionality of tissue engineered cartilage constructs is hampered by the lack of correlation between global measurements of extra cellular matrix constituents and the global mechanical properties. Based on patterns of matrix deposition around individual cells, it has been hypothesized previously, that mechanical functionality arises when contact occurs between zones of matrix associated with individual cells. The objective of this study is to determine whether the local distribution of newly synthesized extracellular matrix components contributes to the evolution of the mechanical properties of tissue engineered cartilage constructs. A computational homogenization approach was adopted, based on the concept of a periodic representative volume element. Local transport and immobilization of newly synthesized matrix components were described. Mechanical properties were taken dependent on the local matrix concentration and subsequently the global aggregate modulus and hydraulic permeability were derived. The transport parameters were varied to assess the effect of the evolving matrix distribution during culture. The results indicate that the overall stiffness and permeability are to a large extent insensitive to differences in local matrix distribution. This emphasizes the need for caution in the visual interpretation of tissue functionality from histology and underlines the importance of complementary measurements of the matrixs intrinsic molecular organization.     

髋臼周围肿瘤切除后功能重建手术的仿真建模方法

目的　研究一套髋臼周围肿瘤切除后重建骨盆环及其内固定系统的精确、快捷的有限元建模方法。方法　首先将第三腰椎至股骨中段及内固定系统行CT扫描后导入医学有限元建模软件Simpleware中处理，用可视化装配法生成含内固定系统的骨盆环STL模型，然后经Geomagic软件修补优化后生成实体模型，并对模型的几何精度进行误差分析。最后导入Abaqus软件中进行有限元分析前处理，生成重建手术的有限元模型并进行计算分析。结果　建立了包括韧带在内的髋臼周围肿瘤切除后重建手术的有限元模型。模型有较高几何相似性及力学相似性。结论　椎弓根钉棒重建法较理想的代偿了缺损区的力传导途径，术后骨盆结构完整，力学响应稳定；可视化装配法简化了含有复杂内固定器系统的有限元建模过程，高精度的逆向工程软件和优化操作保证了模型的精确度。     

The effect of target modality on visual and proprioceptive contributions to the control of movement distance

The goal of this study was to determine whether the sensory nature of a target influences the roles of vision and proprioception in the planning of movement distance. Two groups of subjects made rapid, elbow extension movements, either toward a visual target or toward the index fingertip of the unseen opposite hand. Visual feedback of the reaching index fingertip was only available before movement onset. Using a virtual reality display, we randomly introduced a discrepancy between actual and virtual (cursor) fingertip location. When subjects reached toward the visual target, movement distance varied with changes in visual information about initial hand position. For the proprioceptive target, movement distance varied mostly with changes in proprioceptive information about initial position. The effect of target modality was already present at the time of peak acceleration, indicating that this effect include feedforward processes. Our results suggest that the relative contributions of vision and proprioception to motor planning can change, depending on the modality in which task relevant information is represented.     

基于Kinect体感交互技术的上肢关节活动度测量方法

为了简化人体上肢关节活动度测量过程,提高测量效率和准确度,实现活动度的自动测量,提出一种基于Kinect体感交互技术的测量方法。通过Kinect传感器,捕捉上肢各关节点位置,将关节点数据传至计算机;通过检测上肢体运动平面偏离人体冠状面、矢状面和轴向面的距离,规范上肢的测量动作;自动计算肩、肘等关节各科目的活动度数值,由体感人机交互界面实时反馈测量结果。用该方法对40位受测者分5组(每组8人)进行测量试验,并根据t检验法,得到肩关节外展、内收、屈曲、伸展以及肘关节屈曲科目的|t|值,分别为1.53、1.17、1.30、1.58和1.47,均小于2.776,测量结果与期望值无显著差异,表明系统的测量精确度较高。     

脉搏血氧饱和度检测中自适应滤波消除运动伪差的方法研究

目的研究脉搏血氧饱和度检测系统中运动伪差的消除方法,以提高脉搏血氧仪检测性能。方法通过脉搏血氧仪中的双光束构造噪声参考信号,利用最小均方自适应滤波法消除运动伪差干扰的影响。结果建立了脉搏血氧饱和度检测中消除运动伪差的计算方法,可成功地从运动伪差中提取正常光电容积脉搏波信号作为计算氧饱和度的依据。结论该计算方法简单,可用于实时处理,且测量结果可靠,为进一步抑制脉搏血氧仪噪声奠定了基础。