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1.
介绍了一种结构新颖的便携式脑循环功能分析仪的基本原理、参数算法和仪器设计方法.该仪器动用超声多普勒、超声脉冲和臂式自动血压模块检测颈动脉血流速度、血管管径及肱动脉舒张压和收缩压.根据血液动力学原理建立了简化的脑血管动力学参数计算方法,可获得人体颈动脉系统外周阻力、动态阻力、临界压力及搏动指数等反映脑循环功能状况的动力学参数.该仪器结构精巧、操作便捷、指标敏感,适用于各级医院、医疗机构,特别是基层医院和社区康复中心对脑血管病进行早期诊断.  相似文献   

2.
为研究心血管系统血液动力学特性和评测人工心脏,本文根据弹性腔模型建立了一套能反映血液动力学特性的体外血液循环模拟实验装置,测试血液动力学参量与心室后负荷(即外周阻力R和动脉顺应性C)以及每搏心输出量Vs,心动周期T,心室收缩时间间隔Ts和前负荷等六个参量之间的相互关系,通过改变六个参量的某一个参量而固定其余参量,测试这个参量对动脉血压及流量的影响情况.实验结果与生理情况和数学模型分析相符合,整个模拟装置能够反映血液动力学特性.  相似文献   

3.
在体循环中 ,血液流经主动脉、小动脉 (包括微动脉 )、毛细血管和静脉 ,然后返回心房。小动脉和微动脉对血液流动的阻力大 ,在生理学中称其为毛细血管前阻力血管。由于血液具有黏滞性 ,当血液从主动脉向外周流动时 ,需不断克服血管对血流的阻力 ,因而血压随着远离心室而不断下降。根据生理学测定 ,在主动脉中下降约 1 5mmHg ,在小动脉 (包括微动脉 )中下降约为 5 0mmHg ,在毛细血管中下降约为1 5mmHg。由此可见 ,血压在微、小动脉中下降最快。生理学中对血压在微、小动脉中下降最快解释为 :在各段血管中 ,血压降落的幅度与该段…  相似文献   

4.
血流动力学是指血液在血管系统中流动的力学,主要研究血流量、血流阻力、血压、切应力、扰动流等,以及它们之间的相互关系,对人类生命健康具有重要的影响。血流动力学在血管的弯曲、狭窄、堵塞、分叉以及肿瘤的治疗等方面具有重要的临床研究意义。目前,血流动力学在动脉血管搭桥、冠状动脉狭窄、腹主动脉瘤、动脉粥样硬化、脑动脉肿瘤以及旋动流等方面引起广泛研究。伴随着血流动力学的深入研究,心脑血管的手术规划、介入治疗等得到快速发展,基于血流动力学的临床检测和治疗仪器也越来越多。血流动力学因素,如血管压力、血管阻力、血流量、壁面切应力、血液黏度、流动分离、湍流、涡流等对常见血管疾病以及术后并发症的影响机理正在逐步深入探索之中,并已经取得了一定成果。  相似文献   

5.
天麻素对动脉血管顺应性以及血流动力学的影响   总被引:43,自引:1,他引:43  
本文旨在研究天麻素对动脉血管顺应性和血流动力学等的作用。采用改良风箱模型来计算动脉管的顺应性和血管中血流惯性。在静脉注射天麻素前后,分别记录和计算出狗的血压,心输出量,外周阻力,血流惯性以及中央和外周动脉血管的顺应性。结果表明天麻素具有降低血压和外周务管阻力,增加动脉血管中血流惯性,以及中央和外周动脉血管的顺应性等作用。因此,天麻素是一种有效的能够改善由血管顺应性下降所致的高血压-老年性高血压的中  相似文献   

6.
心脏不断跳动,促使血液循环以维持机体生存。当心室收缩时,左心室的血液射入主动脉,流到颈动脉,股动脉和肝、肾等动脉。右心室的血液射入肺动脉;与此同时,血管内的压力增加,血管扩张。心室舒张时、动脉瓣关闭,血管回缩。各动脉的这种扩张和收缩变化是有节奏和有规律的,而当脏器有病,使外周阻力增大,血管顺应性变差  相似文献   

7.
体外模拟心血管系统血液动力学性能分析   总被引:3,自引:0,他引:3  
为研究人工心脏和心血管系统之间的血液动力学作用机制.根据弹性腔模型建立了一套能反映血液动力学特性的体外血液循环模拟实验装置,测试血液动力学参量与心室后负荷(即外周力R和动脉顺应性C)以及每搏心输出量Vs,心动周期T和心室收缩时间间隔Ts,前负荷等六个参量之间的相互关系.通过改变六个参量中的某一个参量而固定其余参量,测试这个参量对动脉血压及流量的影响情况。实验结果与生理情况和数学模型分析相符合。压力和流量波呈脉动性,与真实生理波形相似。整个模拟装置能够反映血液动力学特性。  相似文献   

8.
本文对原发性高血压(EH)病人30例,正常人30例。观察其外周“压降”发生部位及其上下游血流动力学变化。结果显示:1.EH组外周血压显著下降部位发生于小动脉和微动脉,而正常对照组外周血压显著下降部位仅发生于毛细血管前微动脉,提示EH组总外周阻力血管段延长。2.EH组上游血流动力学异常表现为:(1)动脉血压升高,总外周阻力(TPR)和室壁应力(ESS)等后负荷增加引起左室肥厚(LVH)和舒张功能障碍;(2)动脉顺应性减退,壁剪切应力下降,壁张力增加和壁/腔比率增大。3.EH组微循环障碍表现:微血管压、流、阻异常,微循环储备功能减退,微血管病,加权积分值增加等。  相似文献   

9.
目的 分析体循环血管阻力(SVR)异常在健康人群中的分布特点及心脏功能参数的相关变化。方法 用Bioz.com数字化无创血液动力学监护仪,观察919名健康人体循环血管阻力及平均动脉压(MAP)、心输出量(CO)、心脏指数(CI)、搏出量(SV)、搏出指数(SI)、左心做功量(LCW)等心功能参数。结果 体循环血管阻力异常在低年龄段和高年龄段发生率均较高;女性显著高于男性(P <0.001)。相关因素分析显示,体循环血管阻力与平均动脉压(MAP)、脉压(PP)和左心射血时间(LVET)呈正相关;而与心输出量、心脏指数、搏出量、搏出指数、左心做功量及动脉顺应性(AC)呈负相关。结论 广西壮族人群体循环血管阻力异常与年龄、性别及血压水平密切相关,体循环血管阻力升高,心输出量和心指数降低,心脏泵功能减弱。  相似文献   

10.
许多的理论与实验研究表明,体循环系统中的循环动力学问题。通常采用系统分析法来描述动脉血液动力学特性。本文提出了一种用系统血管床的参数来描述脉动状态下外周血管特性的方法。根据Akaike信息准则与精度估计要求,综合比较了二、三与五元件简单模型的结果。血压数据分析表明,五元件模型可用于模拟电压数据,并从模拟循环系统上可测得外周阻抗突变时的血压波形,尤其是五元件模型更能反映  相似文献   

11.
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.  相似文献   

12.
About 1900, modern food selection and processing caused widespread 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 panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse 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 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.  相似文献   

13.
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.  相似文献   

14.
15.
Newton H 《Medical history》2011,55(2):153-182
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
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.  相似文献   

20.
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.  相似文献   

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