人内耳半规管嵴顶时间常数的定量分析

目的 通过数值仿真和实验定量探究人内耳前庭半规管中的嵴顶时间常数,明确半规管编码角运动的时间过程。方法 建立人双耳半规管数值模型,通过流固耦合数值模拟嵴顶的生物力学响应,进而计算嵴顶的力学松弛时间常数。同时,对志愿者进行前庭眼反射实验,根据志愿者的眼震慢相角速度计算嵴顶的时间常数。结果 通过人内耳半规管数值模型计算得出的嵴顶力学松弛时间常数为3.75 s。通过实验测量得出平均嵴顶时间常数约为4.86 s。数值模型和实验中的结果近似保持一致。结论 人内耳前庭半规管中的嵴顶时间常数大约为4.86 s,反映了嵴顶力学松弛和半规管传入神经适应性的联合作用效果,体现了半规管编码角运动的时间过程。     

数值模拟前庭系统膜迷路的生物力学响应

目的研究平衡感受器嵴顶对旋转椅试验的生物力学响应,为前庭系统功能状态的评估提供定量分析的平台。方法基于健康志愿者右侧颞骨完整的组织切片数据进行三维几何重建。运用拉格朗日法数值模拟头前倾30毅、频率0.8Hz、幅度依40毅的正弦摆动旋转椅试验中受试者前庭系统膜迷路的生物力学响应。结果右耳水平半规管嵴顶峰值位移为54.2μm,后规管嵴顶峰值位移为15.9μm;右耳前半规管嵴顶峰值位移为43.7μm,但是左右耳响应相同,对眼球运动的作用相互抵消;向右旋转,右耳水平半规管壶腹嵴嵴顶法向位移从管侧偏向椭圆囊侧,左耳水平半规管壶腹嵴嵴顶法向位移从椭圆囊侧偏向管侧,向左旋转时则相反。结论数值模拟得到的嵴顶的生物力学响应符合Flourens定律和Ewald定律。     

半规管与动物敏捷度

正半规管是脊椎动物内耳的一个古老组成部分。在有颌动物(有颌骨的脊椎动物)的听泡中,骨性管道和其中的膜性管道组成了半规管,每侧听泡中各有上、外、后3个半规管,代表空间3个不同的平面,分别感受运动过程中头部在不同方向的旋转~([1])。大脑将半规管的传人冲动与耳石、视觉和本体感觉的信息进行整合分析,进而调整运动过程中躯体的姿势和动作~([2])。注视锁定是半规管最重要的功能之一,这一功能是通过前庭眼反射和前庭丘反射实现的,在运动中眼外肌和颈部肌肉需要配合躯体     

基于磁共振数据的三维半规管建模空间方向测量

目的测量半规管相互夹角和空间方向。方法对16例磁共振3D-CISS序列内耳检查影像,分割半规管结构建立三维模型,生成3D PDF文件,在各半规管取3点坐标,通过数学方法对同侧和双侧的半规管相互夹角以及各半规管和水平面的夹角进行计算。结果左右后半规管夹角为98.49°±12.07°,可以推测后半规管和矢状面的夹角为49.25°±6.04°。左右水平半规管夹角为171.58°±3.78°;左侧后半规管和右侧前半规管夹角为165.56°±5.78°,右侧后半规管和左侧前半规管夹角为164.74°±6.46°,左侧水平半规管和水平面夹角为19.43°±3.02°,右侧水平半规管和水平面夹角22.11°±4.12°。结论左右共同平面对半规管近乎平行,后半规管和矢状面的夹角大于45°,两侧半规管总脚分叉点和眼球下缘平面更加接近水平面。     

外半规管良性阵发性位置性眩晕诊断试验分析和物理引擎耳石运动观察

目的对外半规管良性阵发性位置性眩晕(BPPV)诊断试验进行分析,了解其诊断机制。方法建立基于物理引擎三维物理仿真的BPPV迷路模型,设定外半规管不同位置结石,分析水平滚转试验过程不同位置耳石运动情况,进而可以推断所诱发眼震表现。结果水平滚转试验眼震表现形式多样,包括双侧背地眼震,可以判断为壶腹部结石和嵴帽结石,眼震弱侧为患侧;双侧向地眼震,可以判断为外半规管长臂侧结石,眼震强烈侧为患侧;一侧背地眼震一侧向地眼震,考虑长臂侧壶腹部结石;水平滚转试验存在的设计缺陷是会导致耳石复位,影响诊断试验的敏感性。10次重复试验结果一致。结论60°水平滚转试验有效修正了90°水平滚转试验存在的缺陷。基于物理引擎对诊断试验进行分析,对于我们理解外半规管BPPV的诊断机制有重要意义,也有助于改良和创新诊断方法。     

眼动系统研究

Ⅲ前庭眼动系统引言如[1]所述,眼动系统的输出都是眼动信号EOG(Electro oculargraph),然而随着刺激的不同,系统会有不同的神经通路,不同的解剖生理构成。本文研究的眼动信号是典型的眼震图ENG(Electronystagmograph)。众所周知,前庭器官中的半规管是人体运动平衡系统中的重要组成部分,担负着角加速     

上半规管良性阵发性位置性眩晕诊断试验分析和物理引擎耳石运动观察

目的 对上半规管良性阵发性位置性眩晕（BPPV）诊断试验进行分析，了解其诊断机制。方法 建立标准空间坐标系的膜迷路模型，设定膜迷路不同位置结石，基于物理引擎三维物理仿真，分析Dix Hallpike试验和仰卧悬挂头位试验耳石运动情况，进而推断所诱发眼震表现。结果 Dix-Hallpike试验和仰卧悬挂头位试验所有位置的结石都有一定程度的运动，并能诱发椭圆囊的结石经总管进入半规管。出现下跳眼震的情况，包括结石从椭圆囊进入后半规管，对侧后半规管结石向壶腹运动，上半规管的结石从壶腹嵴帽底部滑动到顶部，后者重复诊断实验仍为下跳眼震。重复10次观察，试验结果一致。结论 对于上半规管BPPV的诊断标准，还需要重新评估，观察眼震动态变化是必要的，其诊断方法需要改良。     

后鼓室手术入路的应用解剖学研究

目的　为后鼓室入路手术提供解剖学依据。方法　利用成人 6 0侧颞骨标本 ,用牙科钻磨开乳突腔 ,打开外耳道外侧壁和鼓室盾板 ,充分暴露后鼓室入路手术中有关的解剖结构。以外耳道上棘、面神经管锥曲为测量标志 ,在手术显微镜下 ,对在手术中遇到的解剖结构之间的距离进行了测量。结果　外耳道上棘至砧骨窝、锥隆起、鼓索隆起、面神经管锥曲、外侧半规管、后半规管、前庭窗、蜗窗、匙突、乙状窦垂直部前缘中点、窦膜角的距离分别是 17 19、18 0 2、15 2 2、14 4 9、15 39、17 35、19 5 8、2 0 0 9、2 0 32、15 6 8、18 76mm。面神经管锥曲至鼓索隆起、水平半规管、后半规管的距离分别是 3 33、1 5 3、2 15mm。结论　外耳道上棘、面神经管锥曲是后鼓室入路的重要手术标志 ,鼓索隆起向内 3mm是手术入路的安全区 ,面神经减压术时应避免损伤水平半规管及后半规管等结构     

前庭器感受变速转动的动力学原理

虽然实验早已揭示,人能感觉到变速转动是由于变速转动使前庭器半规管内淋巴流动冲击其感受器而引起的,但至今未见有阐明其原理的完整的动力学理论体系。本研究目的在于构建起这一理论体系。本研究采用理论性研究方法,建立恰当的直角坐标系,揭示优弧具有的优势,引入一系列创新公式,从而实现预期研究目的。研究得出了前庭器半规管内淋巴流动的4条规律,即无流律、流向律、取向律和距离律。本研究的突出意义有:(1)首创所研究问题的动力学理论体系,促进生理科学发展;(2)为医学院校物理课结合讲授医学中的人体物理问题提供实例;(3)为纠正生理学教科书长期存在的相关错误提供理论依据。     

部分迷路切除对桥小脑角区显露及其损伤程度的评价

目的:对迷路入路对桥小脑角区的显露程度及其损伤程度进行定量综合评价.方法:通过对成年国人带颈头颅标本6具(12侧),模拟常规的经迷路入路的手术操作,在迷路后入路的基础上,分别磨除部分半规管(上半规管和后半规管)和全部半规管.每个手术步骤完成后,按Ammirat标准进行评价不同手术入路及其扩大后对桥小脑角区的显露程度,用Horgan法计算出显露面积,并根据损伤程度评分评价3种手术入路及其扩大后的损伤程度.结果:经迷路后入路及其磨除部分半规管和全部半规管的显露程度评分分别为1分、1分和2分,显露面积分别为(304.29±39.74)mm<'2>、(416.13±90.14)mm<'2>和(610.47±109.36)mm<'2>,磨除部分半规管后显露面积较迷路后入路明显增加(P<0.001),而磨除全部半规管后显露面积较磨除部分半规管无显著扩大(P=0.562).而经迷路后入路及其磨除部分半规管和全部半规管的损伤程度评分分别为1分、9分和12分.结论:单纯迷路后入路对桥小脑角区显露有限,在单纯迷路后入路的基础上磨除部分半规管(上半规管和后半规管),对桥小脑角区的显露程度和显露面积明显扩大,但相应的损伤程度扩大,磨除全部半规管较磨除部分迷半规管路并不能明显扩大显露程度和显露面积,且损伤程度明显扩大.     

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 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.     

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.     

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.     

Functional role of fertility α2

Fertility α₂-microglobulin is one of the main proteins expressed between the late lutein phase of the menstrual cycle and the first gestation trimester. It is produced by endometrial secretory glandular epithelium and decidual membrane. It is believed to be involved in the preparation to gestation, conception, normal development of the fetoplacental system, and initiation of labor. The immunomodulating, effect of fertility α₂-microglobulin and its possible involvement in the regulation of fertilization by blocking the spermatozoon reaction with the ovocyte lucid membrane were demonstratedin vitro. The data of structural analysis (appurtenance to lipocalines and unique pattern of N-glycosylation) and analysis of the spatial and temporal parameters of the expression in connection with other events in the organism within the same system of coordinates propated us to investigate the probability of realization of other, so far unknown functions of α₂-microglobulin. The probable mechanisms of realization of the immunomodulating function are analyzed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 10, pp. 364–373, October 1998