首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
热休克对大鼠再灌注性心律失常作用机制的研究   总被引:3,自引:2,他引:1       下载免费PDF全文
目的:研究热休克预处理对SD大鼠再灌注性心律失常的作用机制。方法:取55只SD大鼠,随机分为热休克组(H组,n=29)和对照组(C组,n=26)。H组大鼠给予热休克预处理而C组则否。取H组和C组各16只大鼠行Langendorff离体心脏灌注及模拟缺血再灌注。心电图记录复灌时心律失常情况。并检测复灌时心脏流出液肌酸激酶(CK)的活性。同时检测两组心脏组织中70kD热休克蛋白(HSP70)的相对含量和抗氧化酶活性。接着对其余13只H组大鼠和10只C组大鼠测定心脏乳头肌动作电位,即测定静息电位、动作电位振幅、0期最大上升速率(Vmax)等电生理指标,再以台氏液复灌,观察心肌动作电位恢复到缺血液灌流前形态的时间。结果:①H组的再灌注性心律失常严重程度明显较C组为轻。②再灌注过程中心肌CK的释放量H组显著少于C组。③H组心脏组织HSP70表达量显著多于C组。④H组抗氧化酶活性明显强于C组,脂质过氧化物少于C组。⑤台氏液灌流时心肌动作电位H组Vmax显著低于C组,提示热休克对心肌的快Na+通道有抑制作用。经缺血液灌流10min后,H组的Vmax变化幅度小于C组。以台氏液复灌后,心肌动作电位恢复到缺血液灌流前形态的时间也以H组为短。结论:热休克预处理可以减轻大鼠心肌再灌注性损伤,减少再灌注性心律失常,此作用与心脏组织中HSP70含量的增加和抗氧化酶活性的显著增强有关,同时还可能与热休克对心肌快Na+通道的抑制等电生理作用有关。  相似文献   

2.
热休克蛋白70对离体心脏心肌间质的保护作用   总被引:2,自引:0,他引:2  
目的探讨热休克蛋白70(HSP70)对大鼠离体心脏心肌间质的影响。方法Wistar大鼠16只,分为2组:对照组(C,n=8),腹腔注射生理盐水0.4ml,24h后取离体心脏灌注HTK心脏保护液,4℃保存3h后建立Langendorff灌注模型,灌注KH液2h;实验组(E,n=8),腹腔注射重酒石酸去甲肾上腺素,24h后取离体心脏,方法同对照组。以心肌细胞中HSP70含量、血流动力学指标、心肌组织羟脯氨酸(HP)、内皮索(ET)含量和心肌超微结构等作为观察指标。结果HSP70含量E组与C组比较明显增高;E组心功能恢复方面优于C组(P〈0.05),HP含量优于C组(P〈0.01),ET含量低于C组(P〈0.01),心肌超微结构损伤较C组明显减轻。结论HSP 70对供心心肌间质具有保护作用。  相似文献   

3.
目的:观察心肌缺血再灌注时P-选择素(Ps)表达情况;探讨热休克蛋白(HSP)对缺血再灌注心肌Ps及细胞凋亡表达的影响。 方法:成年雌性Wistar(n=40)大鼠随机分为3组。热休克组全麻后高热处理造成热休克动物模型,对照组及假手术组仅予全麻处理。24 h后热休克组及对照组结扎左冠状动脉前降支(LAD)1 h,再灌注2 h造成心肌缺血再灌注动物模型。假手术组只于LAD处穿线而不结扎。术毕测心梗范围、HSP70、Bax、Bcl-2、Ps、凋亡细胞及血清CK-MB。 结果:热休克组HSP70表达高于对照组及假手术组(P<0.05),后两组无明显差别(P>0.05);热休克组心梗范围小于对照组(P<0.05),CK-MB值低于对照组(P<0.01),凋亡细胞、Bax及Ps表达低于对照组(P<0.05),两组Bcl-2表达无显著差别(P>0.05);假手术组无Ps表达。 结论:HSP70可抑制缺血再灌注诱导的心肌细胞凋亡,抑制Bax表达致Bax/Bcl-2比值下降为其机制之一;Ps参与心肌缺血再灌注损伤;HSP70可能有抑制心肌Ps表达的作用,这或许是热休克预处理对大鼠缺血再灌注心肌的另一保护机制。  相似文献   

4.
热休克反应对缺血-再灌心肌保护作用的机制探讨   总被引:11,自引:1,他引:10  
目的:探讨热休克反应对大鼠缺血-再灌心肌保护作用的可能机制。方法:SD大鼠,随机分为对照组及热休克组,动物经热休克处理恢复2或24h后复制缺血再灌模型并进行各项检测。结果:①热休克处理后心肌组织内SOD活性显著高于对照组,MDA含量则显著低于对照组。②热休克组心肌组织内乳酸及ATP含量均显著高于对照组,糖原含量则显著低于对照组。③热休克反应能诱导HSP70i的转录。结论:热休克反应对缺血-再灌心肌的保护作用与心肌能量代谢的改善、抗氧化能力的增强以及HSP70i的转录合成增强有关。  相似文献   

5.
目的观察去甲肾上腺素预处理后热休克蛋白(HSP70)在心肌细胞的表达以研究去甲肾上腺素预处理对大鼠离体缺血再灌注损伤心肌的延迟性保护作用.方法24只Sprague-Dawley大鼠随机分为对照组(n=8)及实验组(E112h及E24h组),实验组按腹腔注射去甲肾上腺素到建立Langendorff灌注模型的时间分为E12h及E24h组,每组各8只.分别检测LDH及CK的漏出量、心肌ATP含量及心功能指标(LVSP及±dp/dt max),用Westem Blot法测量心肌组织中HSP70的含量.结果E12h组HSP70表达较对照组增高,E24hHSP70表达最高.E24h组LDH与CK含量较其它两组低,而ATP较其它两组高(P<0.01),心功能改善.E12h与对照组相应各指标(LDH、CK、ATP、LVSP及±dp/dt max)间差异无显著性.结论去甲肾上腺素预处理24h后HSP70高表达对大鼠离体缺血再灌注心肌有延迟性保护作用.  相似文献   

6.
目的探讨热休克蛋白70(HSP70)对未成熟心肌细胞功能的影响。方法健康新生长耳大白兔随机分为2组。对照组(C):腹腔注射生理盐水0.4ml,注射后24h取离体心脏,常规建立Langendorff离体心脏灌注模型,灌注15min转为工作心15min后停灌45min,恢复灌注15min改为工作心30min。实验组(E):腹腔注射重酒石酸去甲肾上腺素,24h后取离体心脏,方法同对照组。测定心肌细胞中HSP70含量及相关生化指标并作统计学处理比较。结果HSP70含量E组明显高于C组;E组ATP含量、SOD活性方面均优于C组(P<0.01),MDA含量、CK、LDH漏出率方面均低于C组(P<0.01),心肌线粒体Ca2+-ATPase活性、[ATP]m均优于C组(P<0.01),心肌细胞内Ca2+含量、心肌线粒体Ca2+含量低于C组(P<0.01)。结论HSP70对缺血再灌注未成熟心肌细胞功能具有明显的保护作用。  相似文献   

7.
目的: 研究银杏叶制剂对大鼠脑缺血再灌注后热休克蛋白(HSP)、c-fos表达的影响,探讨其神经保护机制。 方法: 采用改良Longa法复制大鼠局灶脑缺血再灌注模型。56只实验大鼠随机分为正常对照组、假手术组、缺血再灌注组及银杏叶制剂预处理组。银杏组大鼠在实验前灌服银杏制剂2 mL,1日3次,连用5 d。应用HSP70及c-fos免疫组化染色、c-fos mRNA原位杂交、原位细胞凋亡及HE染色等方法观察缺血再灌注不同时点(1 h、6 h、12 h、24 h、3 d、7 d)两者的变化,并对其阳性结果进行半定量分析。 结果: 银杏制剂预处理组各时段神经细胞缺血程度明显轻于未处理组、TUNEL阳性细胞数明显少于未处理组,HSP70及c-fos表达的阳性细胞数则明显多于未处理组(P<0.01)。脑缺血再灌注组1 h 时c-fos即有表达,6 h达高峰,后逐渐下降。再灌注6 h组HSP70在缺血侧皮质及基底节开始表达,24 h达高峰。再灌注6 h细胞凋亡最显著。 结论: 银杏制剂可能通过诱导HSP70及c-fos的表达,发挥其神经保护作用。  相似文献   

8.
地塞米松预处理减轻大鼠再灌注性心律失常的实验研究   总被引:1,自引:0,他引:1  
目的: 探讨地塞米松预处理对大鼠再灌注性心律失常的作用及机制。方法: SD大鼠随机分成地塞米松组、对照组,分别予地塞米松和生理盐水预处理。预处理后构建缺血再灌注损伤动物模型,观察再灌注期间心律失常的发生;Western blotting法和免疫组化法观察心肌HSP72表达变化;测定心肌MDA、SOD、CAT、GSH-Px水平及心肌细胞膜Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性。结果: 与对照组相比,地塞米松组室性心律失常的积分减少(P<0.01)、持续时间缩短(P<0.05);HSP72的表达增加(P<0.05);MDA降低(P<0.01),SOD、CAT、GSH-Px均升高(P<0.05);Na+-K+-ATP酶增加(P<0.01),Ca2+-Mg2+-ATP酶无明显变化(P>0.05)。结论: 地塞米松预处理减少再灌注室性心律失常,其机制可能与其上调HSP72、Na+-K+-ATP酶、抗氧化酶的表达及抑制脂质过氧化反应有关。  相似文献   

9.
李萍  富青  熊凡 《微循环学杂志》2004,14(3):39-41,F009
目的 :探讨热休克蛋白 70 (HSP70 )在心肌缺血再灌注损伤中的表达及其意义。方法 :结扎 /松解SD大鼠左冠状动脉前降支 ,建立大鼠缺血 0min、3 0min ,再灌注 60min、12 0min动物模型。免疫组化技术和图像分析技术检测心肌细胞内HSP70、Bcl 2 /Bax基因的蛋白表达 ,硫代巴比妥酸 (thiobarbituricacid ,TBA)法测心肌组织丙二醛 (MDA)含量 ,优化紫外分光光度法测血清肌酸激酶 (CK)活性。结果 :( 1)HSP70于缺血 0min即有表达 ,再灌注 60min达高峰 ,之后下降。 ( 2 )Bcl 2蛋白再灌注组表达较缺血组明显降低 (P <0 .0 5 )。( 3 )Bax蛋白表达、MDA含量、CK活性于缺血 3 0min开始升高直至再灌注 12 0min。结论 :HSP70的异常表达与心肌缺血再灌注损伤的发生有关 ,且可能是缺血再灌注损伤细胞发展、恶化的重要标志。  相似文献   

10.
目的:观察热休克(heatshock,HS)和缺血预处理(ischemicpreconditioningI.P)对缺血再灌注(I/R)心肌损伤的保护作用,并同时检测HS和IP后热休克蛋白72(HSP),抗氧化酶的动态变化,探讨HSP和IP对缺血再灌注心肌保护的可能机制。方法:建立HS和IP动物模型,检测HS和IP后,模型,检测HS和IP后,0、24、48、96、192hHSP表达水平的变化及再灌注后的心肌组织SOD、CAT、MDA含量变化,最后处死动物,用TTC染色测定心肌坏死范围。结果:再灌注后24h和48h两组心肌组织MDA含量减少,SOD、CAT活性明显高于对照组。对照组、HS组及IP组oh几乎无HSP表达,其表达高峰在HS和IP后24h,48h,随后逐渐降低,于192h返回基线水平。HS和IP组心肌梗死面积较对照组显著减少(P<0.01)。结论:热休克蛋白和缺血预处理均能提高抗氧化酶活性,减轻心肌缺血再灌注损伤。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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.  相似文献   

15.
16.
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   

17.
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   

18.
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   

19.
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   

20.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号