异种骨内固定器力学性能的实验研究

目的了解牛骨材料及其构件的力学强度[抗拉、抗压、抗折(弯曲)和抗扭(剪切)强度].方法将材料分为天然、处理和构件(即产品)三组并制成标准试件,用规定设备按标准方法进行检测.结果(1)牦牛股骨拉伸、压缩、抗折、扭转极限应力分别为106.35±3.45、127.60±2.65、225.9±4.1、53.45±1.55(MPa),胫骨拉伸、压缩、抗折、扭转极限应力分别为114.96±1.46、184.75±3.25、211.35±2.45、51.9±0.5(MPa).湖区水牛胫骨拉伸、压缩、抗折、扭转极限应力分别为1 28.1±11、195.8±9.4、167.4±1 2.7、54.25±0.75(MPa).(2)E0气薰灭菌对牛骨材料的力学性能无明显影响,幅照灭菌对牛骨材料的力学性能稍有影响.(3)处理后,牛骨螺钉、圆钉的抗折强度较材料有所降低,而抗拉强度、抗压强度、抗扭强度变化不大.结论牛骨是一种力学性能良好,适合制作内固定构件的高强度生物材料.     

青海高原牦牛和湖区水牛下肢骨强度的实验研究

目的　了解青海高原牦牛和湖区水牛股骨、胫骨的抗拉强度、抗压强度、抗折 (弯曲 )强度和抗扭 (剪切 )强度。方法　分别取 6头成年青海高原牦牛和 6头湖区水牛的下肢骨 ,按测试要求作成标准件 ,每项测试任取 3个不同源的试样 ,用常规的力学试验设备和方法 ,分别进行两种牛股骨和胫骨的拉伸、压缩、抗折、扭转 4项试验。结果　牛股骨拉伸极限应力 (1 0 6.3 5± 3 .4 5 )MPa ,压缩极限应力 (1 2 7.60± 2 .65 )MPa ,抗折极限应力 (2 2 5 .9± 4 .1 )MPa ,扭转极限应力 (5 3 .4 5± 1 .5 5 )MPa ,胫骨拉伸极限应力 (1 1 4 .96± 1 .4 6)MPa ,压缩极限应力 (1 84 .75± 3 .2 5 )MPa,抗折极限应力 (2 1 1 .3 5± 2 .4 5 )MPa ,扭转极限应力 (5 1 .9± 0 .5 )MPa。湖区水牛胫骨拉伸极限应力 (1 2 8.1± 1 1 )MPa ,压缩极限应力(1 95 .8± 9.4 )MPa,抗折极限应力 (1 67.4± 1 2 .7)MPa ,扭转极限应力 (5 4 .2 5± 0 .75 )MPa。结论　获得了青海高原牦牛和湖区水牛下肢骨极限应力的初步数据     

医用连续碳纤维增强聚烯烃复合材料的生物力学特性测试

目的通过对医用连续碳纤维增强聚烯烃复合材料的生物力学测试,了解其作为硬组织修复材料的力学性能。方法对25根连续碳纤维增强聚烯烃复合材料棒进行拉伸、压缩、弯曲及剪切性能测试,得出该材料的最大载荷、极限强度、弹性模量、泊松比及延伸率。结果极限强度中,拉伸强度(561.11±14.24)MPa,压缩强度(341.91±1.71)MPa,弯曲强度(715.86±19.26)MPa,剪切强度(58.20±15.28)MPa。弹性模量(弯曲)(43.33±1.17)GPa;泊松比0.314±0.005;延伸率(18.20±0.55)%。结论医用连续碳纤维增强聚烯烃复合材料具有良好的生物力学特性,能满足硬组织修复的生物力学要求。     

股骨颈轴向控制髓内钉与A—P型GAMMA钉的生物力学研究

目的研究股骨颈轴向控制髓内钉(axialcontrolledintramedullarynailofthefemoralneck,即ACINFN钉)的生物力学性能,为临床应用提供力学依据.方法24具新鲜尸体股骨标本随机分为对照组和两个实验组.对照组不作任何处理;实验组制成EvansⅠ型粗隆间骨折模型,分别用材料、规格相同的ACINFN钉和A-P型GAMMA钉固定.各组均在双轴液压伺服生物材料测试实验机上做抗压和抗扭转实验.结果在300N的压力下,对照组、ACINFN钉组和A-P型GAMMA钉组的压缩刚度分别为(1568.06±365.81)、(1166.53±91.8)和(224.11±66.45)N/mm,差异有显著性意义(P＜0.01);扭角为5°时,对照组、ACINFN钉组和A-P型GAMMA钉组的扭转刚度分别为(1.14±0.19)、(1.076±0.125)和(0.114±0.065)N@m/deg,差异有显著性意义(P＜0.01).结论ACINFN钉在抗压和抗扭转性能方面明显优于A-P型GAMMA钉,具有良好的生物力学性能.     

医用硬组织黏接胶黏接胫骨中段蝶形骨折的生物力学研究

在粉碎性骨折的治疗中 ,数目较多的骨折碎块的固定仍是一个临床常见的难题。医用硬组织黏接胶是治疗粉碎性骨折的又一新方法 .采用完整新鲜人胫骨、骨块缺失的新鲜人胫骨、黏接后的新鲜人胫骨在扭转、三点弯曲、压缩等状态下的应力 -应变指标变化 ,研究医用硬组织黏接胶黏接人胫骨蝶形骨块后的力学指标的改变。在弯曲、扭转、压缩等实验中 ,胫骨中段的蝶形骨缺损 ,显著减弱了胫骨的抗弯曲、抗扭转、抗压缩的强度。在扭转实验中 ,完整胫骨的扭距大于黏接后的胫骨 ,黏接后胫骨的扭距大于缺损的胫骨。在压缩实验中 ,胶体断裂前 ,完整胫骨的压缩曲线斜率大于黏接后的胫骨的压缩曲线斜率 (P<0 .0 1) ,黏接后胫骨压缩曲线斜率大于缺损胫骨的压缩曲线斜率 ,并有统计学显著性差异 (P<0 .0 5 )。三点弯曲实验中 ,在胶体断裂前 ,完整胫骨的曲线斜率与黏接后的胫骨无显著差异 (P>0 .0 5 ) ,黏接后胫骨与缺损的胫骨曲线斜率有显著差异 (P<0 .0 5 )。黏接后的胫骨 ,其弹性模量、刚度系数与完整的胫骨无显著差异 (P>0 .0 5 )。医用硬组织黏接胶黏接蝶形骨块后 ,能显著提高其抗弯曲、抗扭转、抗压缩应力。在临床操作中 ,可以最大程度上减少骨折碎块固定时周围的软组织剥离 ,有利于骨折的愈合     

臀肌挛缩症的生物力学机制探讨

目的　探讨臀肌挛缩症患者临床表现的生物力学机制。方法　切取手术中得到的臀肌挛缩带及新鲜病尸的臀肌制成肌纤维束标本 ,在MTS生物力学测试机上测定其拉伸的力学性质。结果　臀肌挛缩带拉伸的弹性模量、极限强度和极限应变分别为 (2 .73 2± 0 .792 )N mm2 ,(1 48.3 2± 3 .84)MPa ,0 .896± 0 .3 1 5。而正常臀肌的弹性模量、极限强度和极限应变分别为 (0 .1 43± 0 .0 2 4)N mm2 ,(1 0 .5 0± 1 .69)MPa ,1 .43 4± 0 .40 2。两者间均有显著差异。结论　臀肌挛缩后 ,其强度和刚度增大 ,而弹性则减小 ,这是引起一系列临床表现的力学基础     

兔关节软骨细胞的琼脂糖凝胶培养及其力学性质的研究

目的对兔膝关节软骨细胞进行体外琼脂糖凝胶三维培养,并对其力学性能进行检测。方法将琼脂糖凝胶、细胞、血清和培养基在正确的比例下混合,形成软骨细胞凝胶块。取培养7d、14d和21d时的软骨细胞凝胶块分别对细胞外基质进行组织学观察和免疫组化染色,同时采用Instron 5544材料试验机检测其极限应力、极限应变、抗压模量和切线模量的力学性能变化。结果在琼脂糖凝胶中培养的关节软骨细胞具有典型的软骨细胞特性,能够正常合成细胞外基质,形成有一定弹性和抗压缩能力的软骨样凝胶块。而且随着培养时间增长,基质合成增加,培养21d时的极限应力(0.0226±0.006)N/mm、抗压模量(0.608±0.061)N/mm和切线模量(0.096±0.004)N/mm,比7d时的(0.0204±0.004)MPa,(0.558±0.036)N/mm,(0.029±0.002)N/mm和14d时的(0.0213±0.008)N/mm,(0.586±0.095)N/mm,(0.049±0.005)N/mm有明显增加,但极限应变却没有明显差异(P>0.05)。结论软骨细胞-琼脂糖凝胶块的力学性能与细胞外基质的合成直接相关。     

两种交联处理后猪小肠黏膜下层单轴拉伸性能比较

目的　寻找一种理想的猪小肠黏膜下层(small-intestinal submucosa, SIS)交联处理方法。方法　将来自同一个体的猪SIS分别进行戊二醛处理和亚甲基蓝光氧化交联处理，与新鲜组用相同的方法在万能实验机上做沿管腔纵向单轴拉伸测试，并对极限抗张强度σ(下标 max)、断裂应变ε(下标 m)和0.3MPa 应力下的弹性模量(E)处理研究。结果　三组极限抗张强度分别为(6.01±1.43)、(6.96±0.93)和(12.94±2.03)MPa，戊二醛处理后的SIS在强度上有较大改善，但是组织变得僵硬；亚甲基蓝光氧化交联处理后的SIS强度改善不是特别明显，柔韧性增强。结论　该研究首次使用戊二醛交联和亚甲基蓝光氧化交联方法对猪SIS进行了处理,并比较了与新鲜猪SIS沿管腔纵向单轴拉伸测试力学性能的差异，并证明可以发展光氧化交联方法使其成为一种有效的SIS交联手段。     

第1掌骨力特性及其意义

目的探讨成人第1掌骨的生物力学特性及其在拇指运动中的意义.方法对未固定成人尸体第1掌骨进行压缩和扭转试验.结果得到压缩负荷-位移关系曲线,应力-应变关系曲线,扭角-应变关系曲线,计算得出本构方程和弹性模量.压缩弹性模量(2517.5±576.7)mPa,扭转弹性模量(737.7±249.7)mPa.结论第1掌骨是各向异性材料,纵向加压时弹性较好,在生理限度内可用广义的Hook定律作为本构方程,横向剪切时表现出粘弹材料特性,第1掌骨对抗纵向变形的能力较强.     

3D打印金属椎体替代物力学性能

目的 对钛网及3D打印金属椎体替代物力学性能进行研究,为临床中人工椎体选择与结构优化设计提供指导。方法 通过压缩力学测试,对钛网及3D打印多孔型、桁架型与拓扑型椎体替代物的等效力学属性与结构破坏形式进行系统研究。结果 钛网等效弹性模量[(2 908.73±287.39) MPa]仅次于拓扑型椎体替代物,但其结构强度与稳定性较差,等效屈服强度[(46.61±4.85) MPa]仅高于多孔型椎体替代物,且在压缩中率先屈服;多孔型椎体替代物结构强度[(18.14±0.17)~(25.79±0.40) MPa)]不足,难以满足脊柱重建力学要求;桁架型椎体替代物等效弹性模量[(2 477.86±55.19)~(2 620.08±194.36)MPa]与等效屈服强度[(77.61±0.50)~(88.42±1.07) MPa]良好但稳定性不足,在压缩过程中容易出现失稳现象;拓扑型椎体替代物具有最高的等效弹性模量[(3 746.28±183.80) MPa]与等效屈服强度[(177.43±3.82) MPa],可为人工椎体在体服役安全稳定提供更强保障。结论 拓扑优化方法可实现椎体替代物高强度、高稳定性设计,提供更大的设计空间与安全余量,为人工椎体轻量化与新材料设计提供更多可能。     

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.     

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.