点接触锁定加压接骨板固定骨质疏松粉碎性桡骨骨折的生物力学特征

目的 对比研究新型点接触锁定加压接骨板(point contact locking compression plate, PC-LCP)和动力加压接骨板(DCP)固定老年骨质疏松性粉碎性桡骨骨折的生物力学特性。方法　选取12对老年骨质疏松性尸体桡骨制成横断骨折,骨折间隙为1cm,模拟粉碎性骨折模型。每对随机选取一根用PC-LCP固定,另一根用DCP固定。进行前后四点弯曲、内外四点弯曲及扭转实验,得到相应的弯曲刚度和扭转刚度。 结果　PC-LCP 固定骨质疏松性粉碎性桡骨骨折后的弯曲刚度及扭转刚度均强于DCP,但两者没有统计学差异(P>0.05)。 结论　新型接骨板PC-LCP 固定骨质疏松性粉碎性桡骨骨折的生物力学特性具有优于DCP的趋势。     

自制加锁梅花针治疗股骨中下段骨折的生物力学测试

目的对自行研制的用于治疗股骨中下段骨折加锁梅花针进行生物力学测试,为临床应用提供生物力学基础。方法用6例新鲜成人股骨标本,制作股骨中上段骨折模型两种,梅花针固定;然后制作股骨下段骨折模型两种,加锁梅花针固定;最后利用股骨下段骨折模型交锁钉固定,每次作下一骨折模型前,用钢片张力带固定前一次的骨折线。依次对正常股骨标本、梅花针固定后的标本、加锁梅花针固定的标本、交锁钉固定的标本进行扭转测试、垂直压缩试验、4点弯曲试验,分析4组试验的实验数据。结果梅花针固定股骨中上段骨折、加锁梅花针固定股骨下段骨折和交锁钉固定的股骨下段骨折抗扭转测试中,均可以达到4Nm抗旋转刚度;轴向压缩试验中最大应变正常组和梅花针组、加锁梅花针组无明显差异,4点弯曲试验中梅花针与加锁梅花针和正常标本的弯曲刚度相近,交锁钉的抗弯曲刚度明显高于其他3者。结论加锁梅花针冶疗股骨中下段骨折,具有良好的生物力学性能,固定效果可靠。     

新型点接触锁定加压接骨板的生物力学研究

目的对一种集合点状接触、锁定及加压于一体的新型接骨板(PC-LCP),进行弯曲力学特性、生物力学稳定性测试评估。方法对三种医用不锈钢接骨板,点接触锁定加压接骨板(PC-LCP)、有限接触动力加压接骨板(LC- DCP)、动力加压接骨板(DCP)各3副进行四点弯曲试验;20对新鲜山羊胫骨制成横断骨折,应用三种接骨板固定,进行四点弯曲、扭转及垂直压缩试验。结果PC-LCP弯曲刚度弱于DCP、LC-DCP,三者有显著差异(P<0.05),但三种接骨板固定骨折后的生物力学特性没有显著差异。结论强度稍低的新型接骨板PC-LCP固定骨折后与其它两种接骨板有同样的生物力学强度及较好的力学稳定性。     

两种新型交锁髓内钉的抗扭生物力学性能测定

目的 探讨两种新型交锁髓内钉的抗扭生物力学性能，为临床应用提供依据。方法 采集固定湿润成年尸体股骨四具标本，进行实验应力分析，对股骨干骨折两种新型交锁髓内钉固定的抗扭生物力学性能进行测定，并与传统的梅花针内固定进行对照比较。结果 膨胀螺丝型自锁髓内钉抗扭转强度和刚度，分别达到梅花针的2倍和1.6倍，偏心插销锁定带锁髓内钉抗扭转强度和刚度，分别达到梅花针的1.6倍和1.5倍，但仅为完整骨的30％。结论 两种新型交锁髓内钉都能满足生物力学要求，因而适用于临床上股骨干峡部或峡中以外的稳定或不稳定性骨折。     

六棱交锁胫骨髓内针的研制与生物力学评价

目的：对六棱交锁胫骨髓内针应用于胫骨骨折进行生物力学分析,为临床应用提供科学依据。方法：采用8具新鲜成人尸胫骨应用实验应力分析方法,对六棱交锁胫骨髓内针固定与梅花针内固定进行对照比较。结果：实验结果表明,使用六棱交锁胫骨髓内针内固定胫骨干骨折,无论在抗压、抗弯、抗扭强度、刚度和稳定性方面均明显比常用梅花针内固定来得优越,最大限度地发挥了生物力学效能,两者均具有显著性的差异（P＜0．01）。结论：六棱交锁胫骨髓内针不但能满足临床使用要求,而且能满足生物力学要求,其强刚度性能比梅花针优越,是目前胫骨骨折内固定的优良器械之一。     

锁定加压接骨板固定股骨近端假体周围骨折的生物力学分析

目的评价锁定加压接骨板(locking compression plate,LCP)固定股骨近端假体周围骨折(periprosthetic proximal femur fracture,PPFF)的生物力学强度。方法采用LCP和倒置股骨远端微创锁定接骨板(less invasive stabilization system,LISS)分别固定8对左、右配对的Vancouver B1型成人尸体PPFF标本,假体柄对应长度的股骨分别采用4枚双层皮质锁定螺钉固定(LCP组)和4枚单层皮质锁定螺钉固定(LISS组),骨折远端均采用4枚双层皮质锁定螺钉固定,两种接骨板使用锁定螺钉的螺孔距骨折端的距离相等。通过4点弯曲试验和扭转试验,对比分析两组的最大弯曲载荷、最大弯曲位移、抗弯刚度、最大扭矩、最大扭转角度和抗扭转刚度。结果 LCP组最大弯曲载荷、最大弯曲位移和抗弯刚度均大于LISS组,但差异无统计学意义(P>0.05)。LCP组最大扭矩、最大扭转角度和抗扭转刚度均大于LISS组,差异具有统计学意义(P<0.05)。结论 LCP抗扭转刚度明显优于LISS,对PPFF固定的力学稳定性更好。     

儿童股骨近端解剖钢板生物力学及三维有限元分析

背景：以往的三维有限元研究多集中在成人骨科生物力学方面。 目的：以三维有限元方法分析儿童股骨近端解剖钢板固定股骨转子下骨折的生物力学性能。 方法：从6具儿童尸体上取股骨12根,X射线排除骨病后分为2组,实验组采用儿童股骨近端解剖钢板固定,对照组采用重建钢板固定。分别进行生物力学实验,测试其轴向压缩、扭转刚度、弯曲刚度。选取1名健康男性儿童进行螺旋CT扫描技术,获得股骨近端图像数据,建立儿童股骨近端三维有限元模型,并进行三维有限元力学分析。 结果与结论：在轴向压缩刚度、扭转刚度上儿童股骨近端解剖钢板与重建钢板两者比较差异无显著性意义(P > 0.05);在抗弯曲刚度上,两者相比差异有显著性意义(P < 0.05)。结果显示儿童股骨近端解剖钢板的抗压能力、抗扭能力上与重建钢板相当,而在抗弯曲能力上强于重建钢板。生物力学三维有限元分析显示儿童股骨近端解剖型钢板的设计符合生物力学原理,具有较好的强度、刚度和稳定性,能够满足对儿童股骨近端骨折固定的需要。儿童股骨近端解剖型钢板对固定股骨转子下骨折具有良好的生物力学性能。     

TiNi记忆合金接骨板治疗儿童股骨干骨折

目的探讨TiNi记忆合金接骨板治疗儿童股骨干骨折的临床效果。方法2004年3月～2006年6月应用TiNi记忆合金接骨板治疗8例儿童股骨干骨折。全部病例均获随访,时间8个月～24个月,平均16个月。结果术后X线片复查骨折复位固定满意,接骨板无松动翘起及移位,无变形断裂,骨质无疏松,骨折全部骨性愈合。患肢功能完全恢复正常。结论TiNi记忆合金接骨板是治疗儿童股骨干骨折理想的内固定方法之一,值得基层医院骨科推广使用。     

新型与传统锁定加压接骨板固定股骨干骨折的生物力学比较

目的对比股骨干骨折治疗采用的新型与传统锁定加压接骨板(locking compression plate,LCP)的生物力学性能,为选择更有效的接骨板提供理论依据。方法对接骨板进行弯曲强度与疲劳测试,再结合ANSYS Workbench对接骨板变形、应力及寿命进行有限元分析。结果新型LCP平均弯曲屈服载荷与弯曲强度均为传统LCP的1.4倍,新型、传统LCP平均循环次数分别为106次与47 091次,使用寿命相差33.8%。结论使用新型LCP固定股骨干骨折失效可能性小于传统LCP,新型LCP拥有更有效的生物力学稳定性。     

偏心插销锁定型髓内钉抗扭生物力学性能初步测定

目的 设计一种新型交锁髓内钉——偏心插销锁定型髓内钉，并探讨其抗扭生物力学性能，为临床应用提供科学依据。方法 制作偏心插销锁定型髓内钉，介绍设想、试验、研制过程，并进行实验应力分析，对股骨干骨折用该新型交锁髓内钉固定，对抗扭生物力学性能进行测定，并与传统的梅花针内固定进行对照比较。结果 生物力学试验结果表明，偏心插销锁定型髓内钉抗扭转强度和刚度，分别达到梅花针的1.6倍和1．5倍。结论 该新型交锁髓内钉能满足生物力学要求，因而适用于临床上股骨干峡部或峡部以外的稳定或不稳定性骨折。     

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 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.     

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.     

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.     

Environmental risk factors and their role in the management of atopic dermatitis

Introduction: The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors.

Areas covered: We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD.

Expert commentary: The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures.     

'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 genes in Amerindians from Mexico San Vicente Tancuayalab Teenek/Huastecos

Huastecos or Teenek Amerindians are presently living at North East Mexico (San Luis Potosi State). They have probably one of the most ancient culture of Mexico and Central America together with Mayas and Olmec groups with which also show close relationships. Proximity to Atlantic Ocean/Mexican Gulf originated that Spaniards had very early contact with them at about 1519 CE or before. In the present paper we have aimed to study HLA gene profile which may be useful for HLA and disease epidemiology and transplant programs in Teeneks. HLA-DRB1*04:07, -DRB1*14:06 and -DRB1*04:11 have been found in high frequency like in other Amerindian groups. High frequency typical Amerindians HLA extended haplotypes have been found, such as A*02-B*35-DRB1*04:07-DQB1*03:02; A*68-B*39-DRB1*04:07-DQB1*03:02 and A*02-B*39-DRB1*04:07-DQB1*03:02; also new haplotypes have been described, like A*02-B*52-DRB1*04:11-DQB1*03:02, A*68-B*35-DRB1*14:02-DQB1*03:01 and A*68-B*40-DRB1*16:02-DQB1*03:01. Genetic proximity is observed not only to linguistically close Mayans, but also to Mazatecans, Mixtecans and Zapotecans, who speak an altogether different languages; it shows once more that genes and languages do not correlate. This population was greatly diminished after European contact between 1500 and 1600 years CE; in fact, North and South America First Inhabitants population was brought from 80 down to 8 million people because of diseases (i.e.: measles, smallpox or influenza), slavery and war.     

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.