Usefulness of epithelial membrane antigen (EMA) to discriminate between perineural invasion and perineural indentation in prostatic carcinoma

AIMS: Perineural invasion (PNI) is one of the few unequivocal criteria to diagnose adenocarcinoma of the prostate. Distinguishing PNI from perineural indentation (PNIn), however, is sometimes difficult. The aim of this study was to discriminate between PNI and PNIn using EMA immunohistochemistry. METHODS AND RESULTS: We selected representative sections from 87 prostatectomies with prostatic adenocarcinoma. Normal peripheral nerves were continuously encircled with perineurium, which was immunoreactive for EMA. We identified 1319 PNI by carcinomas, 368 PNIn by carcinomas, and 303 PNIn by benign glands. We categorized the EMA immunoreactivity patterns into three classes: samples that displayed discontinuity or complete loss of the perineurium (Type A), samples where there were carcinomas or benign glands in the perineural space or peripheral nerves (Type B) and samples that showed no changes in the perineurium (Type C). For PNI we observed Type A, Type B, and Type C patterns in 55.3%, 24.8% and 19.9% of carcinomas, respectively. The incidence of each of those patterns in PNIn by carcinomas was 32.1%, 14.9% and 53.0%, respectively. Cases of PNIn by benign glands showed Type A or Type C patterns. They did not, however, exhibit Type B patterns. CONCLUSION: EMA immunostaining will aid the diagnosis of prostatic adenocarcinoma.     

骨重建数值仿真中的控制方程

人体骨组织有着复杂的结构和生理机制,骨重建理论经历了定性分析、定量计算和计算机定量数值模拟三个阶段。目前,存在力学模型和现象模型两类成熟的骨重建模型,力学模型的共性就是表观密度随一定的力学刺激而变化,现象模型由基本多细胞单元的损伤状态和孔隙度变化来决定。大多数股骨重建仿真模型仍然将骨量的分布看作是各向同性的,这就不能完全反映骨组织微构造的本构关系。本文是对骨重建仿真模型的控制方程进行综述。     

Radio-frequency lesioning in brain tissue with coagulation-dependent thermal conductivity: modelling,simulation and analysis of parameter influence and interaction

Radio-frequency brain lesioning is a method for reducing e.g. symptoms of movement disorders. A small electrode is used to thermally coagulate malfunctioning tissue. Influence on lesion size from thermal and electric conductivity of the tissue, microvascular perfusion and preset electrode temperature was investigated using a finite-element model. Perfusion was modelled as an increased thermal conductivity in non-coagulated tissue. The parameters were analysed using a 2(4)-factorial design (n=16) and quadratic regression analysis (n=47). Increased thermal conductivity of the tissue increased lesion volume, while increased perfusion decreased it since coagulation creates a thermally insulating layer due to the cessation of blood perfusion. These effects were strengthened with increased preset temperature. The electric conductivity had negligible effect. Simulations were found realistic compared to in vivo experimental lesions.     

Morphological and biomechanical analyses of the subchondral mineralized zone in human sacral facet joints: Application to improved diagnosis of osteoarthritis

The anatomy of the facet joint subchondral mineralized zone (SMZ) is the main parameter used in diagnosing osteoarthritis. Usually, a single CT scan slice is used to measure the thickness, but the measurement is highly location‐dependent. Bone mineral density (BMD) and porosity could be more reliable than thickness for detecting SMZ sclerosis, and linking them to stiffness can provide insights into the mechanism of osteoarthritis progression. The goal of this study was two‐fold: (1) to assess spatial heterogeneity in thickness, BMD, and porosity within the non‐pathological human facet joint SMZ; (2) to correlate these measurements with the static modulus of elasticity (MOE_sta). Four non‐pathological facet joints were excised and imaged using micro‐computed tomography (µCT) to measure SMZ thickness, BMD, and porosity. A total of eight parallelepiped SMZ samples were similarly analyzed and then mechanically tested. The mean SMZ BMD, porosity, and thickness (± Standard Deviation) of the whole facet joints were 611 ± 35 mgHA/cc, 9.8 ± 1.3%, and 1.39 ± 0.41 mm, respectively. The mean BMD, porosity, and MOE_sta of the eight SMZ samples were 479 ± 23 mgHA/cc, 12 ± 0.01%, and 387 ± 138 MPa, respectively, with a positive rank correlation between BMD and porosity. BMD and porosity were more homogeneous within the facet joint than thickness and they could be more reliable parameters than thickness for detecting SMZ sclerosis. The values for the physiological SMZ and MOE_sta of human facets joints obtained here were independent of BMD. SMZ BMD and porosity were related to each other. Clin. Anat. 28:538–544, 2015. © 2015 Wiley Periodicals, Inc.     

皮肤黏弹性的体内检测方法研究现状与展望

皮肤黏弹性作为皮肤组织的重要生物力学特性,对生理病理状态的分析、诊断、治疗有着极其重要的参考价值和指导作用,是评价皮肤功能的重要指标。近年来,随着生活水平的日渐提高和家庭护理需求的不断提升,人们越来越重视皮肤的美容、保健与护理。因此,与人体皮肤黏弹性相关的体内检测方法得到了广泛关注,皮肤黏弹性体内检测装置的研发也有了进一步推进。本文阐述了各类皮肤黏弹性体内检测方法的原理与技术发展历程,归纳了各种检测方法的优缺点并做了对比分析,最后对皮肤黏弹性未来的研究方向进行了展望。     

生物降解材料的体内降解机理

生物降解材料是一类新型的、应用广泛的生物医用材料,本文对高分子和陶瓷生物降解材料在体内的物理降解、化学降解、生物降解等各种降解作用的机理进行阐述,并对生物衍生类等新型降解材料的降解机理作简要的概述。     

Experimental and numerical study of the colour appearance of tattoo models

The colour of tattooed skin has been predicted by a Monte Carlo method based on the optical coefficient spectra of the skin and tattoo dyes. Slices of pig skin, a tattoo phantom and skin phantoms with different thickness were prepared, and their reflectance and transmittance spectra were measured using an integrating sphere at wavelengths varying from 400 nm to 700 nm. The absorption and scattering coefficient spectra of skin phantoms, pig skins and the tattoo phantom were each calculated using the inverse Monte Carlo method. The skin phantoms and pig skins were overlaid on the tattoo phantom, and the reflectance spectra of the two-layered structures were measured. The reflectance spectra of the two-layered structures were calculated from the optical coefficient spectra using the Monte Carlo method. They agreed well with the measured spectra. The colour differences between the calculated and measured spectra were also evaluated by the L^*a^*b^* colour space distances and showed good agreement, with 3.49 for the skin phantoms and 8.27 for the pig skins.     

医学三维打印材料分类及应用介绍

医学三维打印成品的用途决定了对材料选取的特殊要求,材料主要分为模型材料和生物相容材料两大类。本文旨在对已有的医学三维打印材料进行介绍、比较适用范围和优缺点,并列举应用实例,给医学工作者在选择材料上提供有用的参考。     

Experimental and computational analysis of soft tissue stiffness in forearm using a manual indentation device

A hand held stiffness meter can be used to measure indentation stiffness of human soft tissues, sensitively altered, e.g., by pathological tissue swelling. Under indentation load, the relative contribution of each soft tissue component (i.e., skin, adipose tissue and muscle) to the biomechanical response is not known. In the present study, we evaluated the biomechanical role of different soft tissues in relaxed, physically stressed and oedemic human forearm. Soft tissue stiffness of the forearms of nine healthy human subjects was measured under four different test protocols: (1) forearm at rest, (2) forearm under isometric flexor loading, (3) forearm under isometric extensor loading, and (4) forearm under venous occlusion. In (2) and (3) the loading forces were monitored using a dynamometer, and in (4) the soft tissue swelling was induced by venous occlusion using a pressure cuff. At the site of indentation, thickness of different tissue layers (skin, adipose tissue and muscle) was measured using B-mode ultrasound imaging. Layered, hyperelastic finite element (FE) model of the indentation measurement was created and the model response was matched with that of the stiffness meter to determine the elastic modulus for each tissue in the model. Optimized values of the elastic modulus for skin and adipose tissue at rest were 210 kPa and 1.9 kPa, respectively. Further, significance of the variations in stiffness of different tissues on the indentation response was tested. Experimentally, indentation stiffness of the forearm increased during isometric extensor and flexor loads as well as under venous occlusion by 53, 91 and 15%, respectively. The FE model could reproduce the experimental responses primarily by the increased modulus of skin; 112% (446 kPa), 210% (651 kPa) and 21% (254 kPa) under flexor and extensor loading as well as during venous occlusion, respectively. The indentation response was 9–16 times more sensitive to changes in the mechanical properties of skin than those of adipose tissue and muscle. In conclusion, the present stiffness meter may be used to quantify in vivo mechanical properties of soft tissues in the forearm, sensitively modulated by soft tissue swelling and muscle loading.     

组织工程角膜材料研究进展

1　人工角膜材料人工角膜的发展经历了一个曲折漫长的过程 ,早在 1 789年 ,法国医生ＰｅｌｌｉｅｒｄｅＱｕｅｎｓｅｙ就提出了人工角膜的设想 ,继之而来各国的学者展开了研究 ,使用了不同的光学材料 ,如水晶、玻璃、赛璐珞、石英等 ,目前的人工角膜由二部分组成 :(1 )光柱 :一个光学透明的中心 ;(2 )支架 :周边部既具有支持光柱的功能 ,同时又能与角膜组织形成永久的固定[1] 。1 .1　光柱材料　光柱材料要求首先必须具有较好的光学性能 ,并且具有无化学毒性和良好的生物相容性。早期使用过无机玻璃 ,但因其耐受性较差而基本上被其他材料取…     

荷电材料与钙磷自生长在植入体中的应用

种植材料多种多样,各有优缺点。要使得种植体能与骨组织发生骨性黏结,从而使生活骨与载荷种植体表面形成直接有序的结构和功能整体,人们进行了许多研究,其中荷电材料就是其中一类,并因其具有其他材料所没有的电化学特点而更有利于促进钙磷自生长而值得关注。     

荷电材料与钙磷自生长在植人体中的应用

种植材料多种多样，各有优缺点。要使得种植体能与骨组织发生骨性黏结，从而使生活骨与载荷种植体表面形成直接有序的结构和功能整体，人们进行了许多研究，其中荷电材料就是其中一类，并因其具有其他材料所没有的电化学特点而更有利于促进钙磷自生长而值得关注。     

生物医用钛合金材料的生物及力学相容性

背景：保证生物材料优良的生物及力学相容性是研制开发外科植入物及矫形器械产品的关键,但目前对其研究缺乏系统性和统一性认识。 目的：初步分析生物医用钛合金材料生物及力学相容性的概念、内涵,指导医疗器械产品的选型设计与应用。 方法：应用计算机检索PubMed、Elsiver、Springerlink、CNKI及维普等数据库1995至2012年相关文献,围绕“生物及力学相容性”主题词,探讨合金成分、显微组织及相变控制和材料表面状态优化等因素对钛合金材料生物及力学相容性的影响规律。 结果与结论：生物及力学相容性是一个综合评价概念。进行医用钛合金材料选型设计时,首先要求合金中的组成元素无不良反应,并保证其与组织、血液及免疫和全身反应的安全性,同时要求所添加元素对钛合金的机械性能等其他性能不良影响最小。钛合金中常见的合金化元素主要包括α相稳定元素、β相稳定元素和中性元素3类。要使生物医用钛合金植入材料获得优良的生物及力学相容性,对材料内部显微组织和相变进行控制,以及开展材料表面状态改性优化也至关重要。但不能单纯追求一种钛合金的低模量或高强度等某一单项力学指标与人体骨组织接近或匹配而简单判定其生物力学相容性的优劣。     

植入人体耗材的信息化追踪管理

随着医用昂贵耗材数量、种类的发展和医院管理的不断完善,对植入人体耗材的管理也赋予了新的特征和意义.为此,基于PACS系统开发了植入人体耗材管理系统,不仅实现了耗材基本信息的录入和统计,同时融入了图像信息,最终实现了对植入耗材使用的追踪.     

Distribution of computer-assisted instructional materials in biomedicine through the Lister Hill Center Experimental Network

This paper discusses the organization and present configuration of the Lister Hill Experimental CAI network. Three institutional sources of CAI expertise—University of Illinois Medical Center, Massachusetts General Hospital and Ohio State University College of Medicine—are connected through a commercial time-sharing network to some 50 institutional users. Each of the three institutions provides five access ports, 20 hr a day, 7 days a week. During a month early in 1973 the network logged 2000 hr of use, which gave somewhat more than 4000 student encounters. The network is being operated both as a prototype of a possible service for libraries of the future to offer to their patrons and as an experiment to test the transferability of CAI programs.     

生物降解高分子材料在骨科的应用研究和展望

生物降解高分子材料是现在以及将来研究的热点,其不但可以填补各种类型的骨缺损,具有促进缺损区骨组织再生等作用,而且可减少由于自体骨、异体骨移植所导致的各种风险和不足。本文将介绍目前最受欢迎的几种生物降解高分子材料,其研究现状及未来发展趋势。     

生物型人工韧带的体外检测和体内组织相容性的实验研究

目的:应用最新生化处理技术研制了一种以动物组织为原料的去抗原生物型人工韧带,检测其结构、力学性能及组织相容性,探讨应用去抗原生物型人工韧带重建膝关节叉韧带的可行性。方法:对动物肌腱/韧带组织进行环氧交联固定、多方位去抗原、力学增强改性以及表面活性修饰处理制得生物型人工韧带,应用组织学检查、扫描电镜、细胞培养及力学测试等多种方法分析生物型人工韧带的组织结构、生物力学特性和体内/体外组织相容性。结果:生物型人工韧带的外观与正常肌腱外观相似。组织学检查显示韧带为无细胞的胶原纤维。电镜检查显示韧带为走向一致的发状纤维样物紧密平行排列。异种骨髓基质细胞于韧带表面培养3周,可见细胞黏附并可见细胞分泌的基质沉积于细胞周围,韧带内部未见细胞。人工韧带平均直径约5 mm。在速度100 mm/m in条件下进行力学测试,平均最大拉力为927.19 N,抗拉强度47.22 N/mm2,与正常山羊的前交叉韧带(ACL)相应参数相近。人工韧带置换羊ACL术后12周,韧带表面可见滑膜组织覆盖并有小血管长入,术后52周人工韧带材料被新生的韧带替代,近关节面骨隧道内的人工韧带材料纤维周边可见韧带-纤维软骨-钙化软骨-骨的直接连接模式。结论:应用新的生化处理技术研制的生物型人工韧带有效地去除了猪肌腱的异种蛋白的免疫原性,具有良好的生物力学特性和组织相容性,作为膝关节叉韧带重建的韧带替换材料具有良好的应用前景。     

冷冻外科中组织冻结的实验和理论研究

冷冻外科中组织冻结过程的温度场和温度梯度分布，达到要求温度所需的理论冷量等热力参数对深入分析冷冻损伤机理，指导手术过程十分重要。本文对３．４ｍｍ冷刀在明胶（模拟生物组织）中的冻结过程进行了实验。并用焓法建立模拟生物组织冻结过程的多维数学模型，用有限元法进行了救解。计算结果与实验值符合较好。该模型和方法可用于预测各种壁面降温规律下组织冻结范围、各点温度梯度和理论冷量。     

Stress distributions in maxillary central incisors restored with various types of post materials and designs

Different dental post designs and materials affect the stability of restoration of a tooth. This study aimed to analyse and compare the stability of two shapes of dental posts (parallel-sided and tapered) made of five different materials (titanium, zirconia, carbon fibre and glass fibre) by investigating their stress transfer through the finite element (FE) method. Ten three-dimensional (3D) FE models of a maxillary central incisor restored with two different designs and five different materials were constructed. An oblique loading of 100 N was applied to each 3D model. Analyses along the centre of the post, the crown-cement/core and the post-cement/dentine interfaces were computed, and the means were calculated. One-way ANOVAs followed by post hoc tests were used to evaluate the effectiveness of the post materials and designs (p = 0.05). For post designs, the tapered posts introduced significantly higher stress compared with the parallel-sided post (p < 0.05), especially along the centre of the post. Of the materials, the highest level of stress was found for stainless steel, followed by zirconia, titanium, glass fibre and carbon fibre posts (p < 0.05). The carbon and glass fibre posts reduced the stress distribution at the middle and apical part of the posts compared with the stainless steel, zirconia and titanium posts. The opposite results were observed at the crown-cement/core interface.     

Evaluation of respiratory mechanics and lung histology in a model of atelectasis

To develop a reproducible model of atelectasis, 15 mechanically ventilated Wistar rats were wrapped around the thorax/abdomen with a sphygmomanometer. The cuff was inflated to transpulmonary pressures (PL) of -4 cmH2O (group A) and -8 cmH2O (group B) for 5 sec. Group C was not compressed. Airflow, volume, tracheal and oesophageal pressures were registered. Respiratory system (rs), lung (L), and chest wall resistive (DeltaP1), viscoelastic/inhomogeneous pressures (DeltaP2), DeltaPtot (=DeltaP1 + DeltaP2), static (Est) and dynamic (Edyn) elastances, and DeltaE (=Edyn - Est) were determined before and after compression. In A, respiratory mechanics remained unaltered. In B, Est,rs (+99%), Est,L (+111%), DeltaE,rs (+41%), DeltaE,L (+73%), DeltaP1,rs (+45%), DeltaP1,L (+44%), DeltaP2,rs (+41%), DeltaP2,L (+69%), DeltaPtot,rs (+40%), and DeltaPtot,L (+58%) increased after compression. Mean alveolar diameter and bronchiolar lumen decreased in A, and were even smaller in B. In conclusion, chest wall compression with PL of -8 cmH2O yielded a reproducible alveolar collapse, which resulted in increased elastic, resistive and viscoelastic/inhomogeneous pressures.