共查询到20条相似文献,搜索用时 62 毫秒
1.
VEGF在大鼠局灶性脑缺血再灌注损伤中的表达变化 总被引:3,自引:0,他引:3
目的 研究局灶性脑缺血再灌注中心区、半影区VEGF表达的动态变化及意义.方法 采用线检法制备大鼠局灶性脑缺血再灌注模型.采用神经病学评分、TTC染色、光镜检测对模型予以评价.在此基础上采用免疫组化技术,观察缺血3h及缺血3h再灌注3,6,24,72h缺血中心区及半影区VEGF表达的动态变化,以及观察相应时间点缺血中心区及半影区病理组织学变化.结果 正常对照组及假手术组VEGF呈阳性表达,缺血3h及缺血3h再灌注3,6h中心区及半影区VEGF表达明显增强,缺血3h再灌注24,72h缺血中心区VEGF表达接近正常,而此时半影区呈升高趋势,24h达到高峰,72h有所下降(与假手术组相比,P<0.05).相应神经元的病理组织学变化也随再灌注时间的延长而加重.结论 正常脑组织中VEGF呈弱阳性表达,缺血半影区随缺血再灌注时间延长表达增强.随着缺血再灌注时间延长,中心区神经细胞以坏死为主,半影区以神经细胞以凋亡为主.提示VEGF对脑缺血损伤后的神经细胞有保护和修复作用. 相似文献
2.
目的研究局灶性脑缺血再灌注损伤后神经细胞凋亡及其大鼠脑组织不同时间病理学改变情况.方法随机选取66只成年Wistatr大鼠,按照随机数字法分3组,对照组(假手术组,n=6)、观察1组(脑缺血组,n=24)、观察2组(脑缺血再灌注组,n=36).采用线栓法制造大鼠局灶性脑缺血再灌注模型,手术后HE染色,并分别采用TUNEL法和电镜观察大鼠缺血灌注损伤后神经元凋亡情况和细胞凋亡形态的变化.结果大鼠缺血再灌注后0~63 h时其神经功能损伤最为严重,伴随时间的延长逐渐能得到轻微缓解和改善,再灌注24 h后神经功能明显好转,之后再次出现加重的趋势.研究发现:再灌注后神经元会出现凋亡,TUNEL阳性细胞集中在灌注后病灶中心的边缘区域以及皮层区.结论线栓法制备动物脑组织缺血灌注模型能有效用于脑组织缺血再灌注后的临床分析,局灶区的神经元以凋亡、坏死为主,其中轻度脑缺血主要以神经凋亡为主,中重度缺血主要以坏死为主. 相似文献
3.
叙述了细胞凋亡概念及神经细胞凋亡的基本特征。细胞凋亡是迟发性神经元死亡的基本形式,细胞凋亡在短暂性局灶性脑缺血、短暂性全脑缺血及永久性脑缺血中随缺血时间再灌注时间的不同,细胞凋亡发生部位及时间、范围亦不相同。 相似文献
4.
采用双侧颈总动脉阻断血流(2VO)的方法,造成大鼠不完全性视网膜缺血,用组织学方法观察了不同缺血时间(30、90min,4、7、30d)的缺血后再灌注与不再灌流对视网膜变化的影响。结果显示:缺血30和90min再灌流4d后,内炕网膜(包括外网层、内核层、内网层、节细胞层、神经纤维怪和内界膜)明显增厚;其他不再灌流的缺血组,厚度趋向减少。节细胞计数随缺血时间延长逐渐减少;缺血4d后明显减少。提示不完 相似文献
5.
目的 检测大鼠局灶性脑缺血再灌注后中心区、半影区bFGF的蛋白表达动态变化及意义。方法 采用线检法制作大鼠局灶性脑缺血再灌注模型,采用神经病学评分,TTC染色,光镜检测对模型予以评价,并用免疫组化法观察缺血3h再灌注3,6,24,72h缺血中心区、半影区bFGF表达的动态变化,并观察相应时间点、相应区域病理组织学变化.结果 在正常组及假手术组bFGF呈弱阳性表达.缺血3h及缺血3h再灌注3,6h中心区、半影区表达明显增强.与假手术组比较,差异显著(P<0、05)、缺血3h再灌注24,72h缺血中心区bFGF表达下降,但仍较正常对照组高,此时半影区表达呈持续升高趋势,24h达高峰,72h有所下降。而相应病理变化为:缺血3h可见轻重不等的神经细胞变性坏死,缺血3h再灌注中心区及半影区随缺血再灌注时间延长,病理组织学变化逐渐加重.结论 正常脑组织中bFGF呈弱阳性表达,缺血中心区及半影区随缺血再灌注2d内随时间延长表达增强,与神经细胞缺血改变加重呈正相关.提示bFGF对脑缺血损伤后的神经细胞有保护和修复作用。 相似文献
6.
生长调节物质对丹参叶片脱分化及根芽分化的效应 总被引:11,自引:1,他引:11
生长调节物质对丹参叶片脱分化及根芽分化效应的研究结果表明:(1)0.5~5.0mg/L2,4-D,0.1~0.5mg/LNAA0.5~1.5mg/LIBA或0.2~1.0mg/L4PU-30诱导叶片的脱分化率高达97%~1000%。(2)0.1~0.5mg/LNAA或0.5~2.0mg/IBA诱导芽化率为93%~100%,3种细胞分裂素中,4PU-30对叶片芽化最有效,6-BA和KT次之。(3)随 相似文献
7.
用Langendoeff法灌流雄性Wistar大鼠心脏,平衡10min,于再灌3min内每隔15sec收集一次冠脉流份,连续检测冠脉流份中CK、LDH以及GOT的活性(U/L),比较它们释放的动态特征。结果表明,再灌3min内,3种酶都呈双相释放。第1峰出现在再灌15sec,酶活性为对照值的5-9倍,它主要反映缺灌损伤,再灌90-120sec又出现第Ⅱ峰,主要代表再灌损伤。无论是再灌3min内酶释 相似文献
8.
5—HT1,5—HT2,5—HT3受体激动剂对离体蟾蜍心脏活动的影响 总被引:2,自引:0,他引:2
在离体蟾蜍心脏灌流标本中加入2.5,5.0,10μg/20μl三种不同剂量的(5-HT)后,可引起心输出量减少,心肌收缩力减弱,心率下降,并呈一定的量效关系。5-HT1受体激动剂piperazine2.5,5.0,10g/20μl时,对心率无明显影响,但可使心输出量增加,心肌收缩力加强,亦呈量效关系。 相似文献
9.
在大鼠海马脑薄片上电刺激海马Schaffer侧支纤维,胞外记录CA1区锥体细胞层诱导群体峰电位(Population Spike,PS),观察灌流谷氨酸(Glu)和褪黑素(MEL)40min,人工脑脊液冲洗30min对PS的影响,结果显示:不同浓度(1.0、1.25、2.5和5.0mmol/L)的Glu作用下,70min末PS值百分经分别为1560.5%、150.7%、13.1%、4.1%;并且G 相似文献
10.
目的 探讨bcl-2基因表达在全脑缺血再灌流不同时间的变化规律。方法 本试验在对小鼠双侧颈总动脉阻断再灌流后1,3,7,14,28,42d分别取额叶皮层海马区脑组织,采用免疫组织化学染色,逆转录PCR技术对bcl-2基因表达进行检验。结果bcl-2基因在正常神经细胞中有较弱表达,再灌流1d后其表达开始增加,到7d时达高峰并持续到14d,与对照组有显著差异(P〈0.01)。结论 bcl-2基因抑制 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
14.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献