脊柱侧弯拉伸矫形对漏斗胸胸廓变形影响的研究

目的研究漏斗胸合并脊柱侧弯畸形先行脊柱拉伸矫形对漏斗胸胸廓变形的影响,预测胸廓变形,有助于降低手术风险和提高手术质量。方法选择北京军区总医院胸外科1例16岁男性漏斗胸合并脊柱侧弯畸形患者胸廓CT图,采用三维重建方法重建漏斗胸合并脊柱侧弯的胸廓模型,导入ANSYS软件建立三维有限元模型,用数值模拟方法模拟侧弯脊柱拉伸矫形手术过程,分析脊柱在冠状面及矢状面的位移,并观察分析胸骨在矢状面的位移。结果矫形前的脊柱,胸椎T_3~T_4段向右(X正方向,冠状面)凸出,胸椎T_7~T_9段向左(X负方向,冠状面)凸出。对其先行脊柱拉伸矫形后,胸椎T_3~T_4段矫形后冠状面的位移场(UX)位移为-2.487 mm,胸椎T_7~T_9段UX位移为3.313 mm。脊柱矫形后,最大位移出现在与胸骨柄相连的第1肋上,最大值为13.879 mm;大于2 mm后,胸骨柄的塌陷位移增加较快,拉伸位移超过4 mm以后,胸骨塌陷位移与脊柱拉伸矫形位移呈线性关系。脊柱拉伸矫形后脊柱的最大应力为30.2 MPa,出现在胸椎T_1~T_2段;椎间盘的最大应力为7.03 MPa。矫形力最大为467.9 N,脊柱侧弯得到改善。结论漏斗胸合并脊柱侧弯畸形先行脊柱侧弯拉伸矫形会加重漏斗胸病症,临床应该先行漏斗胸微创矫形。     

Lenke1A/B型脊柱侧弯矫形生物力学计算分析

目的依据脊柱侧弯矫形受力原理,推导出脊柱侧弯矫形角与矫形力的函数关系式,能够快速计算得到脊柱矫形效果最佳的矫形力位置和大小,为脊柱侧弯矫形力的施加提供理论计算方法。方法以脊柱侧弯CT断层扫面数据为基础,采集侧弯脊柱中轴线坐标点,借助MATLAB软件拟合出脊柱侧弯样条曲线,得到脊柱侧弯本构多项式,通过编程求出脊柱侧弯Cobb角的大小。根据脊柱生物力学实验数据及临床骨科医学资料,以弯曲梁模型等效脊柱侧弯主侧弯进行矫形受力分析计算研究。结果推导出了在不同矫形力作用下,脊柱侧弯任意位置矫形力与矫形角度之间的函数关系式。利用函数关系式计算出脊柱的综合弹性模量为0.29MPa。结论通过计算分析为脊柱侧弯矫形过程中矫形力的加载位置、大小与矫形恢复角之间的关系提供可靠的力学理论依据。并可以根据不同的脊柱侧弯类型患者,对矫形角与矫形力函数关系式进行优化,得到优化的矫形力及加载位置。     

基于3D打印技术的定制脊柱侧弯矫形器数字模块化设计研究

针对传统脊柱侧弯矫形器存在设计效率低、贴合性差、加工周期长等问题,本研究基于色努矫形原理,提出采用3D打印技术定制脊柱侧弯矫形器模块化的流程方法。通过构建脊柱侧弯矫形器及调整垫块的三维模型,利用RODIN4D软件分析预测计算矫正过程中的生物力学变化,提出一种矫形器模块化调整的方法。根据个体特征,定制矫正时不同阶段涉及的调整垫块所需的形变量,进行多阶段垫块的3D预制打印,实现矫形调整垫块精准的空间填充与生物力学边缘的高效贴合。基于3D打印技术的个性定制矫形器在治疗周期中模块化调整演进,可以有效提升医师的设计效率,保证患者的穿戴舒适度以及治疗效果。     

漏斗胸微创单根板矫治胸廓成形的生物力学及影响因素

目的 探讨微创矫治漏斗胸的生物力学及影响因素。方法 24例漏斗胸患者,其中男性21例,女性3例;年龄8 ～ 27岁,平均年龄16.3岁。分型：Ⅰ型15例,Ⅱ型 9例。分成儿童组8例,青年组16例。术前测量患者胸围、身高和体质量。胸部CT扫描测量漏斗胸指数（HI）。用微创方法矫治,术中使用1根矫形板;术中用电子显示拉力计测量抬举胸骨单纯成形压力、施压成形压力和矫形板支撑压力,用专用软件分析结果。结果 单纯成形和矫形板的力学强度,24例用单根矫形板者压力,儿童组分别是（127.3 ± 44.3） N、（68.5 ± 14.8） N;青年组分别是（166.6 ± 44.1） N、（89.6 ± 23.4） N;两组前后比较,差异有显著统计学意义（P = 0.000 1）。使用单根矫形板者,儿童与青年组间,单纯成形、施压成形和矫形板压力比较,差异均有统计学意义（P = 0.048）。胸廓矫形力儿童组多与身高、体质量相关,青年组多与胸围、体质量相关。结论 微创矫治漏斗胸术中成形的力学强度与矫形板的位置、年龄、胸围、身高、体质量因素有关。     

成人获得性可复性平足的生物力学研究进展

成人获得性扁平足主要由胫后肌腱功能不全引起,是足踝外科的常见病,其中以可复性平足最为多见。如何解释其发病机制并选择恰当的手术方式治疗是目前研究的热点。随着平足体外建模技术的日臻完善,生物力学试验的准确性和可重复性逐渐得到认可,其研究成果也成为临床平足治疗的重要理论依据。本文回顾了胫后肌腱功能不全导致平足的生物力学机制,及以此为基础在尸体标本和有限元模型上建立平足模型的各种不同方法,并对平足矫形相关基础研究中不同重建方法的生物力学特性进行分析比较。作者认为,在牵拉外在肌腱模拟其动力性稳定结构的前提下,采取破坏韧带等静力性稳定装置的方式建立起的可复性平足体外模型更为可靠;针对平足模型采用的各种重建方式的生物力学特性不尽相同,软组织重建应与骨性手术联合使用,而骨性手术需根据畸形程度和特点进行个性化的选择。     

漏斗胸Nuss手术研究进展

目的 总结漏斗胸Nuss手术的研究进展。方法 在Pubmed、万方数据、中国知网等数据库,以漏斗胸、Nuss手术、外科治疗为关键词,查阅2000年1月—2015年2月有关Nuss手术的相关文献,进行总结分析。结果 漏斗胸是一种胸壁凹陷性畸形,其发病机制尚未明确。Nuss手术是治疗漏斗胸的一种微创手术,具有创伤小、操作简便、并发症少、手术效果良好等优点,已经成为修复漏斗胸的首选治疗方法。随着Nuss手术方法的不断改良以及腔镜技术设备的完善,Nuss手术的适用范围不断扩大,胸腔镜辅助Nuss术已在临床广泛应用,具有手术创伤小、操作简单和快速恢复的优点。结论 Nuss手术的研究发展给漏斗胸患者带来了巨大的福音,但在具体临床应用中,术式的选择尚未达成共识,其发病机制和临床应用的具体问题仍有待进一步的探讨。     

胸腰椎骨折单侧固定的有限元探讨

目的:通过有限元运算方法探讨胸腰椎骨折单侧固定的生物力学效果和可行性.方法:采用正常健康志愿者数据构建胸腰椎骨折有限元模型,装配单侧固定系统和双侧固定系统,对其进行有限元运算模拟.结果:通过有限元运算获得的结果分析,采取单侧固定的静态应力、最大应力与最大位移都明显提示较双侧固定不稳定(P<0.05).结论:胸腰椎骨折采取单侧固定后其有限元运算的结果提示其生物力学效应较差,在临床应用中单侧固定选择需要慎重,避免矫形复位手术的失败.     

成年脊柱侧弯矫形后的断棒现象☆

背景：脊柱矫形内固定疗效的好坏与植骨融合技术以及内固定材料的疲劳特性疲劳寿命直接相关。 目的：分析成人脊柱侧弯矫形后发生断棒的相关因素及临床意义。 方法：对9例成人脊柱侧弯矫形后断棒并进行手术治疗的患者出现断棒时间、活动度、植入物位置、植骨融合率、术中矫形率进行相关性分析。 结果与结论：9例患者中6例存在椎板间植骨融合不充分现象,有明显的植骨融合空白区和假性骨岛生成。经相关分析表明,金属疲劳寿命与植骨融合率、矫形率间呈正相关(P < 0.01)。提示成年脊柱侧弯患者矫形手术中良好的植骨融合条件可以保证在治疗过程中所应用的金属内固定器材处于相对稳定的抗疲劳强度状态,满足内固定治疗过程所需的条件;保证内固定棒获得低于金属固有疲劳阈值点的疲劳状态,达到有效的弹性固定和持续的矫形的目的,并避免断棒现象的发生。      

人体膝关节韧带生物力学研究进展

韧带是稳定膝关节的主要组成部分。如何在生物力学模型中模拟韧带将会影响膝关节动力学特性以及韧带力．韧带应变和接触力分布的计算。本文就韧带在生物力学模型中的简化方法及其力学参数的选择以作一综述．并提出建模的具体方法。     

个性化全骨盆三维有限元建模及骶髂关节骨折脱位模拟

目的建立高度仿真的个性化的完整骨盆三维有限元模型,并在此基础上进行骶髂关节骨折脱位的模拟。方法从CT精确重建独立的左、右髋骨和骶骨实体模型,根据髋骨和骶骨的外形特征,利用专门的流线型生物力学有限元网格划分器生成规则的体网格模型,并进一步建立骶髂关节的终板、软骨、关节接触面,和骨盆上的主要韧带组织及耻骨间盘。在建立的完整模型上去掉一侧的骶髂关节韧带群进行骨折脱位模拟,并与正常的情况进行对比。结果建立了高精度的个性化全骨盆的三维有限元模型,包括左右髋骨和骶骨的皮质骨、松质骨,骶髂关节的终板、软骨和带摩擦的关节接触面,韧带包括骶髂骨间韧带、骶髂前韧带、骶髂后韧带、骶棘韧带、骶结节韧带、耻骨上韧带和耻骨弓状韧带,以及耻骨间盘。正常模型的加载模拟和骶髂关节骨折脱位模拟的预测结果均与文献试验生物力学结果相符合。结论利用专门的生物力学有限元建模工具能建立更复杂更精确的三维有限元模型,成为全骨盆生物力学分析研究的平台和基础。     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.