手舟骨腰部骨折3种内固定方式的有限元分析

目的　通过建立手舟骨腰部骨折三维模型来比较3种不同内固定方式的生物力学差异,为临床内固定方式的选择提供依据。 方法　选取健康志愿者的腕关节CT数据,应用软件建立舟骨腰部骨折的3种内固定方式模型：克氏针固定组、Herbert螺钉固定组、钉脚固定器组。分别在中立握拳位和腕背伸桡偏位施加载荷,并分析舟骨变形量、内固定器械的应力。 结果　在3种内固定装置下舟骨的变形量,克氏针最大,钉脚固定器最小。在两种工况下,舟骨变形量和固定装置的最大应力值不等,但趋势相同,均为钉脚固定器的舟骨变形量最小、所受的最大应力最小。钉脚固定器存在偏心效应,当载荷达到临界值时,易使舟骨愈合面出现开裂或不对称偏心现象。 结论　克氏针固定效果最差,钉脚固定器的固定效果最佳,钉脚固定器术后应适当限制手部负重。     

手舟骨腰部骨折3种内固定方式的有限元分析

目的　通过建立手舟骨腰部骨折三维模型来比较3种不同内固定方式的生物力学差异,为临床内固定方式的选择提供依据。 方法　选取健康志愿者的腕关节CT数据,应用软件建立舟骨腰部骨折的3种内固定方式模型：克氏针固定组、Herbert螺钉固定组、钉脚固定器组。分别在中立握拳位和腕背伸桡偏位施加载荷,并分析舟骨变形量、内固定器械的应力。 结果　在3种内固定装置下舟骨的变形量,克氏针最大,钉脚固定器最小。在两种工况下,舟骨变形量和固定装置的最大应力值不等,但趋势相同,均为钉脚固定器的舟骨变形量最小、所受的最大应力最小。钉脚固定器存在偏心效应,当载荷达到临界值时,易使舟骨愈合面出现开裂或不对称偏心现象。 结论　克氏针固定效果最差,钉脚固定器的固定效果最佳,钉脚固定器术后应适当限制手部负重。     

腰椎峡部裂记忆合金节段内固定器的生物力学评价

目的 :对自行研制的腰椎峡部裂记忆合金节段内固定器进行生物力学评价。方法 :采用MTS-85 8材料试验机先在 0℃条件下测试 10件内固定器的抗拉力情况 ,内固定器在常温下恢复原形状后 ,随机分成 2组 ,分别在 3 7℃及 40℃条件下测量其抗拉力情况 ;2件内固定器施加 2 0～ 2 0 0N进行循环拉伸载荷 (1Hz)测试 ,观察内固定器的形变情况。结果 :0℃条件下内固定器的抗拉力能力明显低于 3 7℃及 40℃组 (P <0 .0 1) ,在 3 7℃及 40℃条件下内固定器被拉开 2mm均需 2 0 0N以上拉力 ,且 2组间无显著性差异 (P>0 .0 1) ;2件内固定器发生形变 6%时抵抗拉伸载荷次数分别为 95 76次和 10 0 2 8次。结论 :腰椎峡部裂记忆合金节段内固定器是一种简便易行、固定可靠的新型内固定器械     

微型外固定支架和克氏针治疗Bennett骨折的三维有限元分析*

背景：有限元分析能够模拟骨外科手术方式,并对模型进行生物力学分析,此方法被认为是一种重要的、新的骨外科生物力学分析方法。 目的：利用三维有限元法分析微型外固定器和克氏针治疗Bennett骨折的稳定性。 方法：获取健康男性志愿者左手及桡骨远端骨CT扫描信息,利用Mimics软件对第一、二掌骨和大多角行三维建模,并对克氏针和微型外固定器材造模;所有数据以STL格式输出到Geomagic软件编辑,得到模型实体,把所有数据以IGES格式输出;之后导入到Aansys软件中,模拟Bennett骨折和微型外固定器外固定及克氏针内固定治疗模型,分别对模型赋予单元类型和属性建立有限元模型。在两个模型的第一掌骨头相同节点处分别施加50 N压力行非线性分析。 结果与结论：微型外固定器治疗Bennett骨折远端骨折块最大移位：X方向位移是-0.492 mm,总位移是0.638 mm;近端骨折块最大位移X方位移是-0.34 mm,总位移是0.659 mm,远近骨折块最大相对位移X方位移是0.15 mm,总位移是0.033 mm。克氏针内固定治疗Bennett骨折远端骨折块最大移位是：X方向位移是-2.873 mm,总位移是5.361 mm;近端骨折块最大位移X方位移是-2.546 mm,总位移是4.294 mm;远近骨折块最大相对位移X方位移是0.676 mm,总位移是1.667 mm。数据表明微型外固定器材外固定治疗Bennett骨折的稳定性优于克氏针内固定治疗,前者降低了术后创伤性关节炎的发生率。 关键词：微型外固定器;克氏针;Bennett骨折;第一掌骨基底骨折;三维有限元;生物力学分析 doi:10.3969/j.issn.1673-8225.2012.09.025      

钢板与克氏针内固定修复跟骨骨折:Gissane角及Bohler角与跟骨高度比较

背景:目前对于经皮撬拨复位克氏针固定与切开复位重建钢板内固定对于跟骨关节骨折长期预后的影响仍然存在一定争议,经皮撬拨复位克氏针固定是一种创伤较小且简便的跟骨骨折修复方法,但是克氏针固定效果并不佳,需要联合外固定治疗,因此严重限制了患者早期活动以及负重行走。目的:对比分析切开复位重建钢板内固定与经皮撬拨复位克氏针固定修复跟骨关节骨折的预后效果。方法:选择2012年3月至2013年9月唐山市丰南区医院收治的跟骨关节骨折患者62例,根据修复方案分为两组,切开复位重建钢板内固定组29例,经皮撬拨复位克氏针固定组33例。对比切开复位重建钢板内固定组与经皮撬拨复位克氏针固定组Gissane角、Bohler角、跟骨高度、治疗后并发症发生率及治疗后1年随访足踝功能AOFAS评分的差异。结果与结论:切开复位重建钢板内固定组治疗后的Gissane角、Bohler角及跟骨高度显著大于经皮撬拨复位克氏针固定组(P0.05);两组治疗后并发症发生率差异无显著性意义(P0.05);切开复位重建钢板内固定组治疗后1年随访的足踝功能AOFAS评分显著高于经皮撬拨复位克氏针固定组(P0.05)。提示切开复位重建钢板内固定能够恢复跟骨及距下关节的正常解剖结构,术者操作熟练可以确保手术安全性,对于跟骨骨折预后改善明显,优于经皮撬拨复位克氏针固定。     

克氏针和绷带固定对微创术后拇外翻的生物力学影响

目的研究第1跖骨远端截骨后克氏针和绷带固定对拇外翻的作用效果。方法通过拇外翻的医学影像数据建立完整的三维足部有限元模型,此模型包括足骨、籽骨、软骨、韧带、软组织、跟腱等;分别建立克氏针和绷带固定的模型,分析拇外翻平衡站立时的足部受载特点。结果绷带固定下截骨之间的压应力(14.9 MPa)大于克氏针峰值应力(6.71 MPa)。从背侧、跖侧、内侧、外侧来看,克氏针固定对截骨面的稳定作用都优于绷带固定,更有利于截骨面的稳定。结论绷带固定可减少截骨端的愈合时间,有利于临床上拇外翻术后固定方式的优化选择。     

双螺栓与克氏针张力带固定治疗髌骨横形骨折模型的有限元分析

目的通过有限元分析法对比双螺栓固定系统与克氏针张力带固定系统固定髌骨横形骨折模型的稳定性。方法基于膝关节CT扫描数据,采用Mimics、Patran及Solidworks软件分别建立双螺栓与克氏针张力带固定髌骨横形骨折的有限元模型,采用Abaqus软件模拟屈膝90°髌股关节作用力600 N,分别对两个模型进行力学加载,分析位移及应力分布情况。结果螺栓系统固定治疗髌骨横形骨折时,螺栓与螺母相对最大位移为0.02396 mm,骨折端的最大接触应力值为47.57 Mpa,骨折端的最大等效应力57.40 MPa,螺栓的最大等效应力值为119.9 MPa;克氏针张力带固定治疗髌骨横形骨折时,克氏针相对最大位移为0.01338 mm,钢丝相对最大位移为0.00857 mm,骨折端的最大接触应力值为26.24 Mpa,骨折端的最大等效应力71.34 MPa,克氏针的最大等效应力值为63.1 MPa,钢丝的最大等效应力值为272.2 MPa。螺栓及克氏针张力带均存在应力集中现象,但最大应力值均小于屈服强度。结论双螺栓固定系统与克氏针张力带固定系统均能够用于髌骨横形骨折的治疗,螺栓固定的骨折端加压力更强,应力更为分散,克氏针张力带系统钢丝应力更为集中。     

新型跟骨外固定支架治疗Sanders ⅢAB型跟骨骨折的有限元分析

目的 应用有限元分析方法,比较一种新型外固定支架与钢板在治疗Sanders ⅢAB型跟骨骨折的应力分布及生物力学的稳定性。方法 获取一位正常成人踝及跟骨CT图像,应用软件构建跟骨Sanders ⅢAB型骨折模型及其外固定模型、钢板模型,经材料赋值及力学加载,记录各模型的骨折块位移情况,并分析其应力分布情况。结果 模型载荷加载后,钢板模型中,钢板及螺钉位移峰值为0.13 mm,跟骨骨块位移峰值为0.26 mm;钢板及螺钉应力峰值为281.10 MPa,跟骨骨块应力峰值为297.40 MPa。外固定模型中,外支架位移峰值为0.17 mm,跟骨骨块位移峰值为0.27 mm;外固定及克氏针应力峰值为125.40 MPa,跟骨骨块应力峰值为38.13 MPa。结论 该新型外固定支架在治疗Sanders ⅢAB型骨折时,固定牢靠、有效,能提供足够的生物力学稳定性,为跟骨骨折的治疗提供了新思路。     

多针内固定治疗跟骨骨折的有限元及临床分析

背景：选择恰当的治疗方法能明显改善跟骨关节内骨折患者的预后。 目的：旨在分析跟骨骨折多针内固定和钢板内固定两种方法的固定效果,评价2种内固定方式的临床疗效。 方法：①CT扫描正常男性右侧跟骨,建立完整跟骨三维有限元模型,模拟Sanders Ⅱ型跟骨骨折,模拟跟骨骨折钢板和多针两种内固定后受到跟腱载荷的工况,对比研究钢板功能位0°、多针功能位0°组、多针跖屈30° 组2种内固定3种分组模型的应力分布、骨折线相对位移和内固定最大主应力。②回顾性研究59例Sanders Ⅱ型跟骨骨折,其中36例患足行切开复位多针内固定,23例患足行切开复位钢板内固定, 采用Maryland足部评分系统评价跟骨骨折钢板和多针两种内固定后的临床疗效,并分析固定后软组织并发症。 结果与结论：①有限元分析中加载足踝静止状态跟腱最大载荷160 N,3组模型内固定的最大主应力值均小于内固定屈服强度225 MPa。3组模型跟骨骨折线的相对移位均小于跟骨关节内骨折手术指征的骨折线分离或移位≥1 mm的标准。连续加载1~1 000 N载荷的工况,3组模型内固定失效时对应的跟腱载荷均大于160 N。模型的应力分布显示,多针与钢板内固定都均匀分布了应力。②临床研究结果显示SandersⅡ型骨折多针固定组优良率83%,钢板固定组优良率78%,两组固定后疗效差异无显著性意义(P > 0.05),但多针固定组固定后软组织并发症发生率低于钢板固定组(P < 0.05)。     

新型交锁髓内钉对尺骨鹰嘴横形骨折固定的力学性能影响

目的 研究交锁髓内钉对尺骨鹰嘴横形骨折的固定效果。方法 收集9对新鲜尺骨标本,建立尺骨鹰嘴横形骨折模型,分别利用克氏针张力带、交锁髓内钉修复骨折;分别模拟肘关节屈曲30°、45°和60°下,在肱三头肌腱处施加幅值25 N、均值45 N和频率0.5 Hz循环动态拉力载荷,记录标本在300个循环周期下的骨折位移。结果 屈曲30°时,交锁髓内钉组、克氏针张力带组骨折位移分别为(1.831±0.333)、(3.723±2.390) mm （P=0.024）;屈曲45°时,交锁髓内钉组、克氏针张力带组骨折位移为分别(1.167±0.374)、(2.455±0.609) mm （P=0）;屈曲60°时,交锁髓内钉组、克氏针张力带组骨折位移分别为(1.407±0.342)、(3.112±1.025) mm（P=0）。交锁髓内钉修复的骨折位移更小。结论 交锁髓内钉的力学性能优于克氏针张力带,交锁髓内钉固定尺骨鹰嘴横形骨折更稳定、更牢固;且利用操作工具安装交锁髓内钉,手术更精准、快捷,手术效率得到极大提高。     

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.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.     

'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.     

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.     

Hypo- und Hypermagnesämie aus kardiologischer Sicht

Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.     

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.     

The case for allele‐specific recognition by the TCR

There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.