非预期条件下前交叉韧带重建术后运动员侧切动作下肢运动生物力学特征

目的 量化非预期条件下前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后运动员侧切动作中膝关节生物力学特征,探讨运动员前交叉韧带(anterior cruciate ligament, ACL)损伤潜在风险。 方法 应用红外运动捕捉系统和三维测力台同步采集 30 名 ACLR 男性运动员在预期和非预期条件下侧切动作中健侧、患侧下肢运动学和动力学数据。 应用双因素方差分析对关节角度、关节力矩、地面反作用力( ground reaction force, GRF)等测试指标进行统计分析。 结果 患侧肢体的膝关节屈曲角度、外翻力矩和屈曲力矩显著低于健侧肢体,内旋力矩和胫骨前剪切力显著高于健侧肢体。 与预期条件相比,非预期条件下膝关节屈曲角度、内旋力矩、胫骨前剪切力显著增加。 患侧肢体膝关节外旋角度在预期和非预期条件下均显著高于健侧,非预期条件下健侧肢体侧向 GRF 和前后 GRF 显著小于预期条件,患侧肢体侧向 GRF 显著高于预期条件。 结论 ACLR 运动员进行侧切动作时,相比于健侧,患侧表现出较小的膝关节屈曲角度,较大的膝关节内旋力矩和胫骨前剪切力的生物力学特征,可能存在较大的 ACL 潜在损伤风险;在非预期条件下,ACLR 运动员双侧下肢均表现出膝关节内旋力矩增大,侧向 GRF 增大和胫骨前剪切力增大的生物力学特征,提示 ACL 潜在损伤风险不仅限于患侧,健侧下肢也应加强侧切动作中 ACL 损伤预防。     

肌内效贴对下肢侧切运动中生物力学特征的影响

背景:肌内效贴扎作为一种运动防护手段已被广泛应用,但作为纠正侧切动作时下肢生物力学异常变化手段的研究,其作用尚不明确。目的:对比受试者膝关节在肌内效贴扎、安慰剂贴扎及空白对照情况下,完成侧切动作时下肢运动学、动力学特征的变化。方法:招募39名篮球专项男性大学生为受试者,每位受试者分别在肌内效贴扎、安慰剂贴扎以及不进行任何贴扎情况下进行测试。采取力学矫正的贴扎方式对受试者优势侧膝关节进行贴扎干预。选取4.5-5.5 m/s的助跑速度完成45°侧切动作,并运用三维动态捕捉系统及测力台同步采集运动学及动力学数据。选取初始触地时刻、地面反作用力峰值时刻的运动学及动力学参数进行数据分析。采用SPSS 27.0软件对测试数据进行统计学分析。结果与结论:①运动学指标:肌内效贴条件下与无贴扎及安慰剂贴扎相比,初始触地时刻髋关节外展、膝关节外翻角度显著减小(P<0.05);侧向地面反作用力峰值时刻,髋关节外展、膝关节外翻及踝关节跖屈角度显著减小(P<0.05),膝关节屈曲角度显著增加(P<0.05)。②动力学指标:与无贴扎相比,肌内效贴扎及安慰剂贴扎条件下均可显著减小初始触地时刻髋关节外展、外旋力矩及膝关节外翻、外旋力矩(P<0.05),显著减小垂直地面反作用力峰值、水平向后地面反作用力峰值(P<0.05);与无贴扎及安慰剂贴扎相比,肌内效贴扎可显著减小侧向地面反作用力峰值(P<0.05)。③结果表明,对膝关节进行肌内效贴扎可在一定程度上改善篮球专项大学生在完成侧切动作时与下肢损伤风险因素相关的部分运动学、动力学指标,可能对预防侧切过程中损伤的发生有一定积极作用;此外,膝关节安慰剂贴扎与肌内效贴扎在部分指标变化方面的作用趋势较为一致,提示肌内效贴扎的作用机制可能存在安慰剂效应。     

假肢对线对大腿截肢者健侧膝关节内部接触力学特性的影响

目的研究假肢对线对大腿截肢者健侧膝关节内部接触力学特性的影响。方法通过步态实验分析健全人及大腿截肢者在不同对线条件下行走时下肢运动及地面反作用力(ground reaction force,GRF)差异,并利用三维有限元模型分析接受腔内收和外展的异常对线情况对膝关节内部股骨软骨、胫骨软骨与半月板之间接触力学特性的影响。结果健全人在GRF第1峰值时刻膝关节接触力主要集中在内侧,在GRF第2峰值时刻接触力主要集中在外侧,而截肢者接触力在GRF的两个峰值时刻都集中在内侧。接受腔对线内收6°会导致膝关节内侧应力、接触力、接触面积均明显增大。结论截肢者膝骨关节炎发病率高于健全人与其膝关节内侧长期过载有关,接受腔对线内收会增加大腿截肢者健侧膝关节骨关节疾病的风险,临床对线过程中应尽量避免过度内收。     

膝关节单髁置换术胫骨假体不同后倾角对假体磨损和功能的影响

目的 建立单髁置换术胫骨假体后倾3°和7°膝关节不同屈膝角度三维有限元模型,研究两种后倾角膝关节生物力学特性和假体磨损及其对功能的影响。方法 结合人体膝关节CT与MRI图像和第3代Oxford假体,建立胫骨假体后倾3°和7°下屈膝单髁置换术有限元模型,在股骨内外侧髁中心点上施加1 kN载荷模拟人体站立相负重,分析不同屈膝角度下单髁假体与关节软骨的最大应力及分布。结果 0°、30°、60°、90°和120°屈膝角度下后倾3°半月板衬垫最大应力分别比后倾7°增加了28.06%、68.99%、19.45%、21.06%、53.38%,应力分布区域从衬垫侧边向中央区域集中,屈膝120°时应力集中明显。胫骨假体后倾3°单髁假体最大应力均大于后倾7°,应力集中区域的扩大会导致假体的磨损和松动,关节软骨接触应力和集中区域随后倾角增大而增大,在高屈曲角度时应力集中更明显。结论 单髁置换术胫骨假体后倾角3°较7°时假体应力和磨损更高,研究结果为临床膝关节单髁置换手术方案设计提供理论依据。     

不同运动贴扎技术对跳深着陆时膝关节应力的影响

背景：贴扎作为一种有效预防运动过程中损伤的方法已得到广泛应用,但采用不同的贴扎方式对膝关节内部应力的影响尚不清晰。目的：分析不同类型贴扎在跳深着陆中对女性篮球运动者膝关节运动学、动力学和软骨、半月板、前交叉韧带应力分布差异的影响。方法：(1)招募10名武汉体育学院篮球专项女大学生,身高(166.60±1.64) cm,体质量(57.50±2.87) kg,年龄(22.40±1.77)岁。每名受试者分别在膝关节无贴扎、肌内效贴扎、重弹贴扎的条件下进行跳跃动作,采集跳深着陆时膝关节运动学与地面反作用力数据。(2)基于膝关节三维有限元模型,以垂直地面反作用力峰值时刻膝关节运动学数据作为边界条件,以股骨长轴方向的合力作为载荷,分析跳深着陆过程中膝关节模型的应力分布情况。结果与结论：(1)收集受试者跳深着陆数据显示,无贴扎组、肌内效贴扎组触地时刻膝关节外翻角度大于重弹贴扎组(P <0.05);无贴扎组垂直地面反作用力峰值时刻膝关节膝外翻角度大于肌内效贴扎组、重弹贴扎组(P <0.05),缓冲阶段峰值膝关节膝外翻角度均大于肌内效贴扎组、重弹贴扎组(P <0.05),缓冲阶段膝关节...     

有限元分析立定跳远状态时不同摆臂动作和触地姿势的膝关节损伤

背景：立定跳远是人体跳跃时常采用的标准动作,同时也是下肢爆发力训练的主要项目之一。大量研究表明,起跳过程中的摆臂动作及触地时足部采用外八姿态能够增加跳跃距离,但鲜有研究关注触地过程中的膝关节损伤。目的：探讨立定跳远不同摆臂动作和触地姿势下双侧半月板和股骨软骨的应力及应力分布特征。方法：招募8名男性大学生进行立定跳远试验,试验中分自由摆臂和限制摆臂起跳、踝关节正常姿态和“外八”姿态触地4种情况,采集跳跃过程中的运动学数据和地面反作用力,通过逆动力学计算获取膝关节反力作为边界条件和荷载。基于1名受试者的膝关节MRI图像,建立膝关节三维有限元模型,对立定跳远触地过程进行数值模拟。结果与结论：(1)摆臂动作与踝关节姿态对膝关节运动学特征的影响存在交互作用,限制摆臂与改变踝关节触地姿态均会对膝关节在矢状面、额状面上的运动学特征产生显著影响(P <0.001,P <0.001);(2)限制摆臂+正常姿态触地与自由摆臂+正常姿态触地时的双侧软骨接触较为均匀,限制摆臂+外八姿态触地和自由摆臂+外八姿态触地的应力集中均发生在软骨内侧而外侧接触较少,内侧软骨较外侧受到更大的冲击;摆臂动作+外八...     

前交叉韧带重建后急停起跳过程中膝关节应力的有限元分析

背景：已有研究分析了前交叉韧带重建患者术后完成不同动作时健患侧运动学、动力学等运动特征,假设前交叉韧带重建术后患者在完成急停起跳动作时健侧前交叉韧带von Mises应力较患侧高,半月板和股骨软骨的von Mises应力较患侧低。目的：通过探究前交叉韧带重建患者健患侧膝关节软组织的应力响应特征,以期为降低该人群发生前交叉韧带二次损伤及慢性膝关节骨性关节炎等继发性损伤提供参考。方法：运用红外光点运动捕捉系统(Nokov)和测力台(Bertec)采集前交叉韧带重建患者急停起跳时膝关节运动学和动力学特征,通过欧拉角计算方法和逆动力获得膝关节三维角度和三维力矩参数,并将膝关节三维角度和力矩作为边界和加载条件分别载入健患侧膝关节有限元模型,进行数值仿真,比较健患侧膝关节内部结构在实际运动载荷下的应力分布情况。结果与结论：(1)在水平向后第一地面反作用力峰值时刻,患侧膝关节屈曲角、内收角明显大于健侧,且健侧垂直地面反作用力高于患侧。此外,健侧垂直地面反作用力峰值出现在急停起跳阶段的4%-6%,而患侧出现在急停起跳阶段的15%-17%,表现出健侧腿较患侧先着地的运动模式。(2)有限元分析显示健侧前交...     

女性全身关节过度活动患者跳深着陆时膝关节应力分析

目的 分析全身关节过度活动(generalized joint hypermobility, GJH)女性患者与健康女性在跳深着陆中膝关节软骨、半月板von Mises应力分布差异。方法 采集女性GJH患者与女性健康受试者在跳深着陆缓冲阶段垂直地面反作用力(vertical ground reaction force, VGRF)峰值时刻的膝关节运动学与地面反作用力特征,通过逆动力学计算膝关节反作用力,并将膝关节沿股骨长轴方向的合力作为载荷;基于1名女性膝关节三维有限元模型,分别对2组受试者跳深着陆过程进行数值仿真,计算膝关节软骨与半月板von Mises应力及应力分布。结果 在跳深着陆VGRF峰值时刻,GJH组和对照组膝关节屈曲、外翻角度具有统计学意义(P<0.05)。相比于对照组,GJH组膝关节屈曲角度降低、外翻角度增加;在跳深着陆中,GJH组膝关节内部承受应力更大且胫股关节内、外侧室负重区应力分布不均衡,其股骨软骨外侧髁外侧、外侧胫骨软骨前部/中部外侧以及外侧半月板前角、体部外侧缘为应力集中部位。结论 女性GJH患者因膝关节活动范围增大、关节囊松弛,导致在跳跃类项目中膝关节...     

前交叉韧带重建术后关节粘连患者在体胫股关节运动学分析

目的 定量分析前交叉韧带重建(anterior cruciate ligament reconstruction, ACLR)术后关节粘连患者在体胫股关节 6 自由度的运动学特征。 方法 纳入 15 例 ACLR 术后关节粘连患者和 15 例健康受试者,运用便携式膝关节三维运动分析系统采集受试者负重屈膝和非负重屈膝时胫股相对于股骨的运动轨迹,获取胫股关节 6 自由度的运动学数据。 结果 与健康人相比,负重屈膝 30°、45°、60°和 75°时,膝关节粘连患者患侧胫骨内旋角度明显减少(P<0. 001);负重屈膝 30° 和 45° 时,膝关节粘连患者患侧胫骨相对于股骨的外翻角度较健康人明显减小(P<0. 05)。 非负重屈膝 75°时,膝关节粘连患者患侧胫骨内移距离较健康人明显减少(P<0. 05)。 结论 关节粘连限制了胫骨相对于股骨的旋转和内外移,对于胫骨相对于股骨的前后移动影响不大。 因此,临床上应该利用各种治疗手段松解股骨内外侧沟的粘连和外侧副韧带挛缩,解决旋转和内外移动受限的问题,以最大程度恢复膝关节功能。     

基于CT和MRI膝关节有限元模型建立与不同载荷下生物力学特性分析

基于CT和MRI图像数据建立膝关节有限元模型,采用六面体网格对不同载荷系统下人体膝关节生物力学特性进行研究,并进行有效性验证。建立膝关节有限元模型包括:股骨、胫骨、髌骨、腓骨、股骨软骨、胫骨软骨、腓骨软骨、半月板、前后交叉韧带、内外侧副韧带、髌韧带和股四头肌腱等。对膝关节施加1 kN轴向压缩载荷、134 N后向抽屉力和5、10、15 N[?m内翻力矩和外翻力矩,分析膝关节内软骨和半月板的接触应力和接触面积,股骨内外翻倾角以及位移变化情况。在1 kN压缩载荷和134 N抽屉力作用下,股骨软骨、内外侧半月板和内外侧胫骨软骨的接触应力峰值分别为4.47、3.25、2.83、2.70、2.53 MPa,Von Mises应力峰值分别为2.22、2.44、2.25、2.07、1.64 MPa。股骨相对胫骨前向位移为4.19 mm。施加5、10、15 N[?m内翻和外翻力矩时,股骨内翻和外翻倾角分别为3.49°、4.48°、4.91°和3.22°、3.62°、4.01°。随着力矩的线性增大,膝关节各组成部分的应力呈非线性变化趋势。膝关节软骨、半月板和韧带的研究结果符合其生物力学特性,与前人数值分析和实验研究结果相一致,可为临床膝关节生理病理分析和治疗提供一定的理论依据。     

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.     

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.     

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 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.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.     

A comparative study of the effects of dimebon,obsidan, finoptin,and cordaron on the functional state of ischemic focus and size of necrotic zone in experimental myocardial infarction

Dimebon, an antihistamine agent, exerts a moderate antianginal effect, improving the function of ischemic focus in the myocardium and decreasing the necrotic zone in experimental myocardial infarction. Dimebon is less active than obsidan, finoptin (except for the size of the necrotic zone), and cordaron. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 642–644, December, 1996     

Effects of sex steroid hormones on lipid peroxidation and glutathione antioxidant system in rat skin

Effects of estradiol and testosterone on the intensity of lipid peroxidation and contents of glutathione redox system components in the dermis and epidermis of rat skin were studied. Only estradiol induced considerable dose-dependent and tissue-specific biphasic antioxidant effects on the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 12, pp. 663–666, December, 1999     

Adhesion and growth of CaCo2 cells on surface-modified PEEK substrata

A series of surface-functionalized poly(ether ether ketone) (PEEK) films has been prepared by selective wet-chemistry; they are hydroxylated polymer (PEEK-OH) obtained by reduction, aminated polymer (PEEK-[]-NH2) prepared by coupling a diisocyanate reagent to PEEKOH (PEEK-[]-NCO) followed by hydrolysis, and carboxylated and aminocarboxylated polymers (PEEK-[]-GABA and PEEK-Lysine) resulting from the coupling of aminoacids to PEEK-[]-NCO. The aminated and carboxylated substrata promoted the adhesion and growth of CaCo2 cells in the presence of serum. Fibronectin (FN), an extra-cellular matrix protein, has been covalently fixed and/or adsorbed on various PEEK substrata, in the presence or not of a polymeric surfactant (Pluronic F68). The performances of the FN-grafted substrata (PEEK-[]-FN(1) and PEEK-[]-FN(2)) were significantly higher than those of reference substrata simply coated with FN (PEEK-OH(+FN)(1) and (2), PEEK-[]-NH2(+FN)(1) and (2)), considering the adhesion and spreading of CaCo2 cells in the absence of serum. Moreover, the stability of the adherent cells on the FN-adsorbed substrata dramatically depended on the experimental conditions applied during the PEEK coating with FN.     

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.