典型中耳病变对圆窗激振听力补偿性能影响的数值分析

目的研究典型中耳病变对圆窗激振听力补偿效果的影响,为圆窗激振式人工中耳的优化设计提供参考。方法利用CT扫描和逆向成型技术建立包括中耳和耳蜗的有限元模型,并验证模型的可靠性。再基于该模型,通过改变相应组织的材料属性,分别模拟镫骨环韧带硬化、镫骨不正常发育和锤骨前韧带硬化3种典型中耳病变。通过对比相应的基底膜响应,分析这3种病变对圆窗激振听力补偿效果的影响。结果镫骨不正常发育主要在高频处降低圆窗激振的效果,镫骨环韧带硬化和锤骨前韧带硬化主要恶化圆窗激振低频段的响应。3种病变中,镫骨环韧带硬化对圆窗激振听力补偿效果影响较大,等效声压的减小量可高达17 d B。结论中耳病变恶化圆窗激振的听力补偿效果,且恶化量较大,故在设计圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。     

高压对耳蜗的影响

目的研究高压环境对人耳蜗的影响,弥补试验手段不足导致的耳蜗在高压环境下听力行为特征研究的缺失,为今后对耳蜗进行针对性研究提供新的思路。方法基于健康人耳蜗CT扫描图像,结合自编程序,利用PATRAN软件建立三维螺旋耳蜗有限元模型。应用NASTRAN软件进行流固耦合频率响应分析和瞬态响应分析,通过数值模拟方法研究高压对耳蜗的影响。结果基底膜12 mm处与镫骨底板中心(卵圆窗的中心)处位移比值模拟结果与已报道的试验结果相吻合,验证了所建模型的正确性。高压环境下,耳蜗中基底膜特征频率点的幅值随着压强的增大而不断减小。结论高压环境最终导致人耳听力的降低。研究结果为临床上研制防治高压的缓冲装置提供理论支撑。     

细菌生物膜厚度和面积对人耳听力的影响

依据临床健康志愿者右耳的CT扫描结果,将CT扫描数据数值化导入PATRAN软件进行人耳三维有限元模型的重建,并用NASTRAN软件对该模型进行频率响应分析。通过对正常人耳结构进行频率响应分析得出数据与实验数据吻合,验证了模型的正确性。结合临床中耳炎病症实际情况,研究细菌生物膜的成长阶段对人耳听力的影响。结果表明：在不同声压相同的频率段,细菌生物膜的厚度变化对人耳听力的影响是相同的。在相同声压不同频率段,细菌生物膜的厚度增加会引起镫骨振幅和速度降低,在较低频率段镫骨振幅和速度下降幅度较大,下降的最大值为1.64 dB;在较高频率段镫骨振幅和速度下降幅度较小,下降的最大值为1.04 dB。在不同声压作用下,在相同的频率段细菌生物膜的面积增加会引起镫骨振幅和速度降低。在100～1 000 Hz频率段镫骨振幅和速度的下降幅度较小,下降的最大值为0.18 dB。在1000～10 000 Hz频率段镫骨振幅和速度的下降幅度较大,下降的最大值为2.26 dB。细菌生物膜厚度或面积增加都会使人耳听力下降,厚度增加在低频时比高频时下降更多,而面积增加则刚好相反。     

中耳畸形对圆窗激振听力补偿性能影响的数值分析

目的研究中耳畸形对圆窗激振性能的影响,为圆窗激振式人工中耳的优化提供理论支持。方法构建包含两腔不对称的非螺旋耳蜗的人耳有限元模型,并与实验数据进行对比,验证模型的可靠性。基于该模型,通过改变相应组织的材料属性,分别模拟听骨链固定、听骨链融合、听小骨缺损3种中耳畸形对圆窗激振性能的影响。结果中耳畸形主要影响圆窗激振式人工中耳的低频性能,听骨链固定和听骨链融合对圆窗激振起恶化效果。镫骨固定对圆窗激振补偿性能的影响最大,恶化量高达47.93 dB;听小骨缺损可提高圆窗激振的性能,最大改善量为6.24 dB。结论中耳畸形对圆窗激振的低频性能有影响,临床植入圆窗激振式人工中耳时需要针对性地提高其作动器的输出量。     

外耳道静压对声音传递和耳蜗输入影响数值分析

为分析静压变化对中耳听骨链运动和耳蜗输入的影响,运用有限元模型研究外耳道静压导致的中耳声音传递功能和耳蜗激励输入改变。首先,根据相关实验测量数据并结合有限元分析,拟合了耳道静压力与中耳各构件有效弹性模量关系的经验公式;然后,通过材料参数的改变模拟压力造成的中耳结构刚度增加,分析耳道静压对中耳机动性的影响和不同耳道压力下镫骨底板位移、速度和耳蜗两窗压力差的变化。计算结果与相关的文献实验数据有较好的符合,说明所建立的计算模型在模拟静压条件下中耳传递功能方面的合理性。结果表明在低频范围(0～0.6 kHz)外耳道静压对两窗压力差的影响稍大于对镫骨位移的影响。     

中耳病变及人工镫骨形体研究

目的 研究听骨韧带、肌腱硬化和切除以及人工镫骨置换对声音传导的影响。方法 基于CT扫描数据,通过自编C＋＋程序读取CT数据中体单元建立人耳结构几何模型,将几何模型导入PATRAN中赋予材料参数、设置关节接触面以及相应其他边界条件生成数值模型。结果 利用本文人耳数值模型进行正常耳和病变耳的谐响应分析,得到正常耳和病变耳镫骨底板和鼓膜凸的振幅变化规律。并由此构建了套型人工镫骨。结论 正常耳的模拟结果与实验测试结果吻合,证明了本模型准确性,可以模拟人传声功能。本模型模拟病变耳的计算结果可以从力学角度解释病变对声音传导的影响,为病变耳治疗提供参考。本文的套型人工镫骨较我国临床用的环型人工镫骨更吻合人耳的生理功能,其重建听力效果更好。     

高压下中耳结构动力损伤研究

目的研究高压对中耳结构造成的损伤。方法基于CT扫描建立中耳结构有限元数值模型,对模型施加随时间变化的压力,分析鼓膜以及镫骨足板的应力、应变和位移变化。结果获得的计算结果与相关文献中的试验数据吻合,验证了所建中耳模型的准确性。高压会对中耳造成损伤,随着压力的增加,损伤加重;快速加压使得中耳损伤严重,对内耳的影响较小;慢速加压也能导致中耳损伤,但在中耳损伤前,内耳会损伤。结论高压容易导致人耳出现损伤,为避免听力受到影响,在加压过程中要控制好加压速率。     

人工听骨不同接入方式对耳结构动力响应的影响

目的 研究人工听骨接入方式对听力恢复的影响。方法 通过CT扫描技术,结合自编C＋＋程序读取CT数据中体单元建立人耳结构几何模型,将几何模型导入PATRAN中建立有限元数值模型。采用频率响应方法对耳结构模型进行流固耦合计算,同时分析人工听骨不同接入方式及接入位置对耳结构声音传导的影响。结果 通过对正常人耳的动力响应分析,得到数值模型中计算出的鼓膜凸与镫骨底板振幅与试验数据吻合,验证本文模型的正确性。结论接在鼓膜凸的位置其动力响应最好,镫骨振幅高于其他连接方式。即人工听骨接在鼓膜凸的位置比较吻合人耳的生理功能,其重建听力效果更好。     

不同激振位置对压电式人工中耳听力补偿性能的影响

研究不同激振位置对压电式人工中耳听力补偿性能的影响,确定压电式人工中耳最优激振位置。建立人耳有限元模型,并通过和相关实验数据进行对比验证模型的可靠性。基于该模型,分别在鼓膜脐部、砧骨体、砧骨长突和圆窗施加相同的位移驱动,通过检测镫骨足底板位移及基底膜的最大位移,分析这些位置的激振对人工中耳听力补偿性能的影响。结果表明,以镫骨足底板位移为评估标准会低估圆窗激振的高频听力补偿效果。砧骨长突激振下的基底膜特征位置处的运动位移大于激振鼓膜脐部及激振砧骨体时的位移值,其中激振砧骨体时的基底膜特征位置处运动位移最小;激振圆窗时的基底膜特征位置处运动位移在低频段小于激振其他位置时对应的位移值,但在中、高频段其激振效果最好。在频率低于400 Hz时,砧骨长突激励听力补偿效果最好,圆窗激励听力补偿效果最差。当频率大于1 kHz时,圆窗激励听力补偿效果比其他位置好。以传统的镫骨足底板响应为评估标准,将低估圆窗激振式人工中耳的听力补偿效果。     

应用多层螺旋CT对耳硬化症的术前评估价值

目的:评估MDCT在术前耳硬化症诊断中的作用。方法:收集经临床证实为耳硬化症、且CT扫描采用螺旋扫描病例共18例,采集的数据传输到4.1工作站,进行多平面重建。结果:18例共36耳显示异常:单独前庭窗异常18耳,表现为前庭窗扩大或狭小,周围骨质密度降低或镫骨底板板密度增高;前庭窗及蜗窗同时受累共8耳;主要累及耳蜗周围迷路骨质10耳,表现为耳蜗骨迷路边缘不整,呈条片状密度减低或双环征。MPR交互重建充分显示了所有重要解剖结构的位置、形态:其中3耳为颈静脉球高位。结论:MDCT可以正确显示耳硬化症病灶的细微改变,提供详细的术前诊断信息;结合MPR技术可全面观察病变范围,并充分显示颞骨内重要解剖结构的位置和形态。对于手术方案的设计、防止手术并发症和提高疗效等具有重要意义。     

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.     

Studien zur humoralen Regulation des erythropoetischen Proliferationsspeichers beim Menschen

Zusammenfassung Die Beeinflussung der Erythroblasten-Proliferation durch das Mikromilieu wurde in vitro mittels Auswertung durch Differential- und Mitosezählungen und Signifikanzberechnung vieler Versuchsreihen auch unter verschiedenen pathologischen Bedingungen getestet.Sowohl die Mitosehäufigkeit wie die Ausreifung waren positiv mit dem Erythropoetingehalt des Medium korreliert. Der Effekt wurde durch Folsäure, Ätiocholanolon und cAMP verstärkt. Cobalt stimulierte ebenso wie Testosteron und Methenolon in vitro unabhängig von der Erythropoetinkonzentration im Medium die Erythroblastenproliferation. Ein vermindertes Eisenangebot störte die endgültige Ausreifung der Erythroblasten zu Retikulozyten und bewirkte dadurch eine Ineffektivität der Erythorpoese. Anhaltspunkte für ein Erythrozyten-Chalon oder einen Erythropoetinhemmkörper ließen sich aus unserem Versuchsansatz nicht gewinnen, weil er die Transformation der pluripotenten in die erythropoetin-sensible Stammzelle nicht einschließt. Als Nebenbefund ergab sich eine Stimulation des granulozytopoetischen Proliferationsspeichers durch Serumzusatz zum Medium von Patienten nach akutem Blutverlust und bei Polycythämia vera.Unterstützt durch die Deutsche Forschungsgemeinschaft     

HLA study in Amerindian Bolivia La Paz Aymaras

Aymara people has been a relatively homogeneous group since Spanish Conquest by 1,532 CE, even if previously represented a group of various cultural defined populations who gave rise to them. They were and are established in Andean Altiplano around Titikaka Lake (Bolivia, Peru), Argentina and Chile neighborhood, speak Aymara language and have been maintained after Europeans arrival at a lower social status than Quechua (Inca) speaking people. However, both Aymara and Quechua populations acknowledge Titikaka Lake as center of their origins; both languages are also related. Specific high frequencies of HLA-A*02, -A*24 and -A*68, HLA-B*35, -B*39 and -B*48, HLA-DRB1*08:02, -DRB1*09:01, and -DRB1*14:02, and HLA-DQB1*04:02, -DQB1*03:02 and -DQB1*03:01 alleles are found in Aymaras and HLA class II haplotypes common to Andean Amerindians (DRB1*08:02-DQB1*04:02 and DRB1*04:03-DQB1*03:02), like Quechua, Aymara, Uros, Lamas and Mapuche are also found in Easter and other Pacific Islands. Giant human head stone statues at Tiwanaku (Titikaka Lake, Bolivia) are also found at Easter Island. Thus, it is possible a gene and cultural flow between Andean Amerindians and Easter and other Pacific Islands, as it was demonstrated by Thor Heyerdahl in his Kon-Tiki expedition which reached Pacific Islands sailing from El Callao Harbour (Lima, Peru).     

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.     

Lipid composition of metacestodes of Taenia taeniaeformis and lipid changes during growth

A lipid analysis was performed on developing metacestodes of Taenia taeniaeformis removed from the livers of rats at times varying from 3 to 35 weeks post infection. Lipid accounted for 7–21% of the dry weight of the parasites. The highest proportions were found at the earlier stages. The distribution was as follows; neutral lipid 27–45%; glycolipid 5–11%; and phospholipid 50–61%. The major neutral lipid was cholesterol, and minor neutral lipids were sterol esters, triglycerides, diglycerides and monoglycerides. Hydrocarbons were present throughout development, but in the highest amounts at the earlier stages. Five different glycolipids were found, all of which were identified as glycosphingolipids. An increase in the proportion of more complex glycolipids was noted as parasites grew older. Ten different phospholipids were identified, with the major components being phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. Other phospholipids were: lysophosphatides, phosphatidylinositol, phosphatidic acid, diphosphatidylglycerol, sphingomyelin, and an unknown phospholipid component. Changes in the relative amounts of the two major phospholipids were found when the early and late stages were compared. Two lipids found throughout development were identified as glycosylated dolichol phosphates, and they comprised between 1 and 3% of the total phospholipid fraction. Nineteen fatty acids were detected, and the fatty acid distribution for each lipid class at each stage was determined. Seven major fatty acids were common to each. These were: hexadecanoic, octadecanoic, oleic, linoleic, arachidonic, docosanoic, and docosahexaenoic.     

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.     

Simple Serological Assays for Detecting Rice Tungro Viruses

An attempt was made to produce sensitive and specific polyclonal antisera against the viruses causing rice tungro disease, and to assess their potential for use in simple diagnostic tests. Using a multiple, sequential injection procedure, seven batches of polyclonal antisera against rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV) were produced. These were characterized for their sensitivity and specificity using ring-interface precipitin test and double antibody sandwich (DAS) ELISA. Thirty-one weeks after the first immunization, antiserum batch B6b for RTBV showed the highest ring interface titer (DEP = 1:1920). For RTSV, batches S3, S4b and S5b all had similar titres (DEP = 1:640). In DAS-ELISA, however, significant differences among purified antisera (IgG) batches were observed only at IgG dilution of 10^-3. At that dilution, IgGB4b showed the greatest sensitivity, while IgGS3 showed greatest sensitivity for RTSV. When all IgG batches were tested against 11 tungro field isolates (dual RTBV-RTSV infections) at sample dilution of 1:10, IgGB4b and IgGB6b for RTBV and IgGS3 and IgGS6b for RTSV performed equally well. However, after cross adsorption with healthy plant extracts in a specially prepared healthy plant-Sepharose affinity column, only IgGB6b could be used specifically to detect RTBV in a simple tissue-print assay.     

Is it worthy to take full-course immunotherapy for allergic rhinitis? About efficacy biomarker of allergen immunotherapy

Nowadays, people pay more attention to biomarkers that can predict clinical efficacy of immunotherapy for allergic rhinitis. As the only recognized aetiological treatment, the efficacy of allergen immunotherapy (AIT) has been proved by many studies. However, treatment success depends on compliance and persistence greatly, which can be impaired by the lengthy duration of AIT and socioeconomic status of patients. Besides, ineffectiveness is another factor that accounts for non-adherence. If the clinical efficacy can be predicted in the early stage of immunotherapy, it can help patients choose appropriate treatment plans, increase patient compliance and optimize the allocation of medical resources. This paper mainly focuses on five candidate biomarkers, the sIgE/tIgE ratio before treatment, serum inhibitory activity for IgE, decreased basophil activation, upregulation of Tregs and tolerogenic DCs, reviews the time when potential biomarkers can predict or monitor the efficacy of AIT, discusses the reason why these indicators could serve as efficacy biomarkers and interactions among potential biomarkers.     

Neurotransmitter signaling pathways required for normal development in Xenopus laevis embryos: a pharmacological survey screen

Neurotransmitters are not only involved in brain function but are also important signaling molecules for many diverse cell types. Neurotransmitters are widely conserved, from evolutionarily ancient organisms lacking nervous systems through man. Here, results are reported from a loss‐ and gain‐of‐function survey, using pharmacological modulators of several neurotransmitter pathways to examine possible roles for these pathways in normal embryogenesis. Applying reagents targeting the glutamatergic, adrenergic and dopaminergic pathways to embryos of Xenopus laevis from gastrulation to organogenesis stages, we observed and quantified numerous malformations, including craniofacial defects, hyperpigmentation, muscle mispatterning and miscoiling of the gut. These data implicate several key neurotransmitters in new embryonic patterning roles, reveal novel earlier stages for processes involved in eye development, suggest new targets for subsequent molecular‐genetic investigation, and highlight the necessity for in‐depth toxicology studies of psychoactive compounds to which human embryos might be exposed during pregnancy.     

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.