人体椎骨松质骨力学参数实验研究

本文作了椎骨松质骨力学特性实验。首先建立了包括微机数据采集系统的实验系统。对314个人体胸椎,腰椎松质骨试件分别沿轴向,横向和矢向压缩做了破坏实验。测定了中国成人椎骨松质骨的强度、弹性模量,泊松比和密度等参数。对各类不同试件力学特性的差异进行了统计检验,并对各参数间的关系进行了回归分析。由实验和计算结果可以得出:椎骨松质骨轴向强度、弹性模量显著大于其正交方向的值,与轴向正交各方向的力学特性参数间无显著差导。整椎强度明显大于松质骨强度,皮质骨起着不同于松质骨的承载作用。松质骨强度、弹性模量,密度之间显著正相关。数据集中反映了中国人青壮年组椎骨力学参数的特点,实验结果为建立脊柱动力学模型及研究各类椎骨损伤提供了基础数据。     

股骨颈松质骨拉伸蠕变实验研究

研究了正常国人新鲜尸体股骨颈松质骨的拉伸粘弹性力学性质.对股骨颈松质骨纵向、横向、45°方向试样进行拉伸蠕变实验.得出了股骨颈松质骨三个方向的蠕变数据和曲线.对实验数据进行归一化处理,用指数一元回归分析的方法处理数据,得出了归一化蠕变函数及曲线.实验结果表明,股骨颈松质骨纵向组蠕变量均大于横向组和45°方向组,股骨颈松质骨为各向异性材料.     

股骨颈松质骨拉伸应力松弛实验研究

目的　研究正常国人新鲜尸体股骨颈松质骨的拉伸粘弹性力学性质 ,为临床提供生物力学参数。方法　对股骨颈松质骨 90°、0°、4 5°方向组试样在ShimadzuAUTOGRAPH电子万能试验机上进行拉伸应力松弛实验。结果　得出了股骨颈松质骨 90°、0°、4 5°三个方向的应力松弛数据和曲线 ,对实验数据进行归一化处理 ,用对数一元回归分析的方法处理数据 ,得出了归一化应力松弛函数及曲线。结论　股骨颈松质骨组 90°方向组应力松弛量大于 0°方向组和 4 5°方向组。股骨颈松质骨为各向异性材料。     

股骨颈松质骨三方向压缩应力松弛蠕变实验

研究正常国人新鲜尸体股骨颈松质骨的压缩粘弹性力学性质,为人工关节的研制提供生物力学理论基础.对10具正常国人新鲜尸体股骨颈松质骨纵向、横向、45°方向试样进行压缩应力松弛、蠕变实验.得出了股骨颈松质骨3个方向的应力松弛、蠕变数据和曲线.对实验数据进行归一化处理,分别用对数、指数一元回归分析的方法处理数据,得出了归一化应力松弛、归一化蠕变函数及曲线.说明股骨颈松质骨纵向组应力松弛量、蠕变量均大于横向组和45°方向组.股骨颈松质骨为各向异性材料.     

退行性腰椎侧凸程度与骨质疏松症程度无关

背景：骨质疏松是以全身骨组织显微结构损坏及全身骨量减少为特征,有学者认为骨质疏松患者腰椎椎体前高不会减少,反而会有增加的趋势。 目的：分析退行性腰椎侧凸与骨质疏松症的相关性。 方法：选取退行性腰椎侧凸患者37例,另选取同期在住院治疗的腰椎非侧凸组患者37例。测量时采用改良Cobb法,沿患者的T12-L5各椎体上终板平行划线,2条线的最大夹角为侧凸角,两线所在椎体即为上、下端椎。运用双能X射线吸收法对患者L₂-L₄、股骨颈、Ward’s三角区以及股骨转子的骨密度进行测定。采用Linear regression对骨质疏松和退行性腰椎侧凸症的相关性进行分析 结果与结论：腰椎侧凸组患者L₂-L₄、股骨颈、Ward’s三角区以及股骨转子部位的骨密度T值与腰椎非侧凸组比较差异有显著性意义(P < 0.05),其中股骨各部位骨密度较腰椎(L₂-L₄)较低。腰椎侧凸组患者骨质疏松症发病率明显高于腰椎非侧凸组患者(P < 0.05)。Linear regression回归分析结果显示骨质疏松症是退行性腰椎侧凸发病的危险因素;退行性腰椎侧凸患者的腰椎及股骨近端各个部位的T值与侧凸Cobb’s角无明显相关性。结果提示,骨质疏松症是退行性腰椎侧凸发病的危险因素,同时骨质疏松程度与侧凸程度无关。     

基于显微磁共振成像和有限元分析的股骨近端微观力学行为研究

目的 本研究利用高分辨率显微磁共振成像（micro-magnetic resonance imaging,μMRI）在呈现骨微结构方面的优势和对人体无辐射的优点,结合有限元分析（finite element analysis,FEA）,无创探究人体在自然站立状态下股骨近端微观力学行为,明确股骨易骨折危险区域,为μMRI-FEA未来临床应用提供理论基础。方法 采集5例年龄55～63岁女性志愿者（58.4岁±3.4岁）的股骨近端μMRI图像。将图像中骨骼和软组织分割,三维重建得到包含股骨近端皮质骨和松质骨微结构的大尺度三维有限元模型（约一千万六面体单元）,赋予非均匀材料属性。模拟人体自然站立时股骨的受力,将其远端固定,在股骨头部位施加压缩载荷,进行线弹性有限元分析,得到股骨近端的应力和应变分布,并选取股骨颈和大转子部位10 mm~3松质骨感兴趣区域进行比较。结果 人体自然站立姿态下,股骨颈上、下侧皮质骨分别出现拉、压应力集中现象。股骨颈松质骨感兴趣区域在上下（superior-inferior,SI）、内外（medial-lateral,ML）和前后（anterior-posterior,AP）三个方向上的正应力（σ_(SI)、σ_(ML)、σ_(AP)）分别为大转子部位的13.4倍、2.2倍和1.9倍;正应变（ε_(SI)、ε_(ML)、ε_(AP)）分别为大转子部位的7.4倍、5.0倍和4.0倍。结论自然站立时股骨颈皮质骨和松质骨所受应力和应变较大,提示股骨颈是易发生骨折的高危区域,与临床观察一致。本研究为μMRI-FEA未来应用于临床无创评估股骨骨折风险进而鉴别骨折高风险人群提供了一定的前期理论支撑。     

前外侧或后内侧辅助钢板结合髓内钉固定胫骨近端 1 / 3 骨折的生物力学研究

目的 研究髓内钉结合辅助钢板固定胫骨近端1/3骨折的稳定性,比较并观察胫骨近端1/3骨折后内侧辅助钢板与前外侧辅助钢板结合髓内钉固定的生物力学特点。方法 选取Sawbones第4代人工胫骨模型。根据辅助钢板位置分为后内侧钢板组和前外侧钢板组,每组4例,髓内钉远近端均2枚锁定钉固定,钢板远近端各3枚皮钉双层皮质固定。模拟AO分型41-A2型骨折,水平截骨平面位于胫骨髓内钉近端锁定钉远端0.5 cm即近端关节面以远5～6 cm位置。截骨完成后,通过生物力学试验机分别进行轴向压缩、三点弯曲、循环加载及极限应力测试,比较各组轴向刚度、三点弯曲刚度等结果。结果 轴向压缩实验表明,后内侧钢板组平均轴向刚度低于前外侧钢板组,两组间差异无统计学意义。三点弯曲实验表明,后内侧钢板组无论是对抗内翻应力(钢板位于骨折压力侧,t=3.679,P<0.05)还是外翻应力(钢板位于骨折张力侧,t=8.975,P<0.05),其弯曲刚度均优于前外侧钢板组。结论 辅助钢板结合髓内钉固定胫骨近端1/3骨折可以提高近端骨折块固定的稳定性,并允许患者更早负重。钢板置于后内侧或者前外侧均能够提供足够的轴向强度,后...     

腰椎爆裂骨折椎体松质骨内力学分布特点的有限元研究

目的运用有限元方法模拟腰椎爆裂骨折的过程,观察腰椎在轴向压缩载荷作用下松质骨内的应力分布情况。方法建立正常人体胸腰段(T12~L2)运动节段的三维有限元模型,在T12椎体上表面施加不同等级的压力(0.4、0.6、0.8、1.0、1.2 k N),模拟腰椎爆裂骨折发生时椎体承受的不同等级的轴向压缩载荷。将连接椎体上下终板凹面顶点的连线7等分,在此基础上将L1椎体中的松质骨划分为7个具有统计节点的层面,每个统计层面划分成6个统计区。分别测量L1椎体松质骨内3个层面(第1、4、7层面)18个统计区的平均应力。在同一等级载荷下对3个层面内的平均应力进行单因素方差分析,分析腰椎椎体松质骨内不同载荷作用下的应力分布情况。结果在5个不同等级载荷下,第1、7层松质骨平均应力分别与第4层比较有统计学意义(P0.05),而第1、7层平均应力比较无统计学意义(P0.05)。轴向加载时,相比第1、7层应力,椎体松质骨中间层面(第4层)应力最小。结论腰椎在轴向压缩载荷作用下,椎体松质骨内存在应力集中的现象,接近椎体上下软骨板的松质骨应力较大,而椎体松质骨中间层面应力较小,椎体内应力集中分布在上下软骨板的特点与腰椎爆裂骨折所致终板破裂的生物力学机制相一致,提示腰椎椎体骨结构损伤可能与椎体内应力集中有关。     

内侧支撑螺钉在锁定钢板治疗肱骨近端骨折中的生物力学优势

目的探讨内侧支撑螺钉在肱骨近端锁定钢板固定肱骨近端骨折中的生物力学性能。方法将30个人工合成左侧肱骨随机分成3组,建立外科颈骨折模型,采用肱骨近端锁定钢板固定:A组,近端内侧骨皮质支撑,无内侧支撑螺钉;B组,3枚内侧支撑螺钉支撑,无内侧骨皮质支撑;C组,无内侧骨皮质和内侧支撑螺钉支撑。分别对3组标本进行轴向压缩、抗扭、剪切力压缩、模型失效测试。结果 A、B、C 3组轴向压缩最大载荷为A组((240.88±19.13)N)>B组((169.04±19.26)N)>C组((128.58±17.53)N),P<0.05);抗压刚度为A组((424.4±101.2)N/mm)>B组((230.7±40.54)N/mm)>C组((147.0±29.2)N/mm,P<0.05);抗扭测试最大扭矩A组((8.92±0.25)N.m)、B组((9.09±0.31)N.m)>C组((7.57±0.53)N.m,P<0.05),抗扭刚度A组((1.80±0.07)N.m/(°))、B组((1.86±0.07)N.m/(°))>C组((1.53±0.10)N.m/(°),P<0.05);剪切力压缩测试最大载荷为A组((444.71±20.87)N)>B组((228.79±28.95)N)>C组((188.73±26.15)N,P<0.05),抗压刚度为A组((470.0±54.4)N/mm)>B组((183.89±29.64)N/mm)>C组((140.2±32.1)N/mm,P<0.05);模型失效载荷A组((2 949.76±355.08)N)>B组((2 448.13±402.39)N)、C组((2 222.55±336.41)N,P<0.05)。结论肱骨近端内侧骨皮质支撑具有最佳的生物力学性能,采用3枚内侧支撑螺钉重建肱骨近端内侧柱支撑的生物力学性能较无内侧柱支撑时明显增强。通过内侧骨皮质支撑或内侧支撑螺钉重建肱骨近端内侧柱支撑值得临床运用,以预防术后内固定失败。     

治疗股骨转子间骨折时头颈拉力螺钉不同置入位置的有限元计算

背景:课题组总结发现,股骨转子间骨折股骨近端髓内钉置入内固定治疗后出现髋内翻的病例中,除小部分由于股骨转子部粉碎性骨折和个别存在复位问题之外,绝大多数出现并发症的患者术后复查X射线片可见,2枚头颈拉力螺钉位置均位于股骨颈中上部。目的:通过有限元计算,验证股骨近端髓内钉头颈拉力螺钉不同置入位置的生物力学性能,从而指导股骨近端髓内钉置入以减少置入后并发症的发生。方法:利用MIMICS中的布尔运算将股骨近端髓内钉置入骨折模型,建立三维模型。实验分为2组:中下组股骨近端髓内钉头颈拉力螺钉置于股骨颈中下1/3处;中上组股骨近端髓内钉头颈拉力螺钉置于股骨颈中上1/3处。利用有限元软件计算头颈拉力螺钉于不同方向置入时股骨及股骨近端髓内钉的应力分布情况。结果与结论:骨折断端应力分布结果显示,中下组小转子处所受压应力小于中上组,并且中下组股骨近端髓内钉各钉所受最大应力平均值大于中上组。骨折断面张开角测量结果显示,加载后中下组骨折断面张开角小于中上组。载荷与位移关系分析结果显示,加载后中下组股骨上部合位移小于中上组。说明2枚头颈拉力螺钉置入股骨颈中下1/3处时,生物力学性能更好,结构相对更稳定,受力更合理,在临床中具有重要的参考价值。     

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.     

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.     

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.     

Class II HLA in Georgia Caucasus Tbilisi Georgians and their Mediterranean ancestry: The Usko Mediterranean languages

Georgia (or Sakartvelo in its own language) is a South Caucasus Mts. country with its easternmost part is enigmatically named Iberia, like the Iberian Peninsula, which may refer to rivers “Kura” and “Ebro” or their valleys respectively. Most of their inhabitants speak Georgian which is included within Dene-Caucasian group and Usko-Mediterranean subgroup of languages. The latter includes Basque, Berber, ancient Iberian-Tartessian, Etruscan, Hittite, Minoan Lineal A and others. In the present paper, HLA class II -DRB1 and -DQB1 alleles has been studied and extended haplotypes calculated. Most frequent haplotypes are also of Mediterranean origin (i. e.: (A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*51)-DRB1*13:01-DQB1*06:03, or (A*24-B*35)-DRB1*01:01-DQB1*05:01) and DA genetic distances show that closest world populations to Georgians are Mediterraneans. Georgians also show common extended haplotypes ((A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*13)-DRB1*07:01-DQB1*02:01 and (A*03-B*35)-DRB1*11:01-DQB1*03:01) with Svan people, a secluded population in North Georgia mountains. We can conclude that Georgians belong to a very old Mediterranean substratum according to both linguistics (Usko Mediterranean languages) and HLA genetics.     

'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.