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表皮生长因子对培养的气道上皮细胞抗臭氧损伤的保护作用 总被引:8,自引:2,他引:8
本研究观察到臭氧(O3)对体外培养经3H-UdR标记的免气道上皮细胞有明显细胞毒性作用,且损伤程度与O3作用时间呈正相关。O3暴露组细胞内丙二醛(MDA)产生增多(P<0.01),提示O3损伤细胞的机制与胞膜脂质过氧化有关。表皮生长因子(EGF)可明显降低O3所致的3H释放率(P<0.01)、降低O3的细胞毒指数及细胞内MDA含量(P<0.01),证明EGF对气道上皮细胞有保护作用。进一步还观察到浓度为5ng/ml的EOF可以取消O3所引起的细胞内还原型谷胱甘肽(GSH)含量降低(P<0.01),并增加细胞内谷胱甘肽总含量(P<0.05),但不能改变O3所致的氧化型谷胱甘肽(GSSG)含量的增加(P>0.05),对GSH/GSSG比值也无明显提高,这些都提示EGF的细胞保护机理可能与其促进细胞内谷胱甘肽合成有关,而对GSSG转化为GSH的还原过程影响不明显。 相似文献
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本文动态观察了用平阳霉素诱发的大鼠白内障晶体中与谷胱甘肽代谢相关酶类活性和微量元素水平的变化,并与正常晶体进行比较,同时就酶活性与微量元素水平的相关性进行了检验。结果表明:(1)注射平阳霉素早期酶活性增高,谷胱甘肽过氧化物酶(GSH-Px)、谷胱甘肽还原酶(GSSG-R)及超氧化物歧化酶(SOD)等活性的升高达显著水平,后期酶活性均下降,尤以GSH-Px、GSSG-R和谷胱甘肽硫转移酶(GSH-S)等的活性降低明显;(2)GSH-Px和SOD酶活性分别与Zn具有相关性(P<0.05),这两种酶也分别与Se具有高度相关性(P<0.01),此两种元素在该类型白内障形成中可能有一定意义。 相似文献
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目的探讨老年高血压病的高胰岛素血症(HIS)与血脂及血管紧张素(Ang)的关系。方法比较48例老年高血压病患者和54例老年非高血压病患者空腹血糖、胰岛素、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)、AngI、Ⅱ水平。结果老年高血压病组空腹胰岛素显著高于非高血压病组(P<0.01);高血压病组TG、AngⅡ显著增高(P<0.05);高血压病组血糖、TC、HDL、AngⅠ与非高血压病组无明显差异(P>0.05)。结论老年高血压病患者存在HIS,且脂质代谢异常,伴有AngⅡ升高。 相似文献
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通过培养的人主动脉平滑肌细胞(hASMC)及脐静脉内皮细胞(hUVEC),应用3H-TdR参入、Northernblot分析、逆转录多聚酶链反应(RT-PCR)、放射免疫分析(RIA)、和紫外比色法等技术观察了人主动脉中硫酸乙酰肝素蛋白聚糖(HSPG)对hASMC和hUVECDNA合成的作用及对血小板源生长因子(PDGF)、PDGF受体、转化生长因子β(TGF-β)、内皮素-1(ET-1)或碱性成纤维细胞生长因子(bFGF)基因表达和肾素-血管紧张系统(RAS)的影响,结果显示,HSPG明显抑制培养的hASMC基础的DNA合成(cpm值为:10385±3263vs,25541±6421,P<0.01)及外源性PDGF诱导的DNA合成(cpm值为:9878±1947vs.13481±44l0,P<0.05);抑制PDGFA链、TGF-Bp和ET-1mRNA表达,提高PDGFa和β受体mRNA的表达;显著降低hASMC培养液中血管紧张素Ⅱ(AngⅡ)的浓度和血管紧张素转换酶(ACE)的活性,推测HSPG抑制PDGFA链、TGF-β及ET-1mRNA表达,降低ACE活性及AngⅡ浓度是其抑制hASMC增殖的重要机 相似文献
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迷走神经兴奋对HRV的影响及其机制的初步分析 总被引:3,自引:0,他引:3
实验在氯醛糖加氨基甲酸乙酯麻醉的新西兰兔上进行。记录血压、心率、心电图和心率变异性(HRV)频谱分析。电刺激减压神经(DN),疑核(NA)和右侧迷走神经(RV)外周端,均引起心率和血压下降(P<0.001),总变异性(TV)、低频成分(LF)、高频成分(HF)、LF/HF比值(LF/HF)和极低频成分(VLF)增大(P<0.05-0.001)。静脉注射阿托品可使上述反应显著减小(P<0.05-0.01),而静脉注射心得安仅可阻断DN和NA所致LF的增大(P<0.05)。以上结果表明:迷走神经是HRV的主要调节者之一;HF由迷走神经单独介导;LF受迷走神经和交感神经共同调制;迷走神经参与VLF波的形成 相似文献
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促性腺激素对猪卵丘细胞-卵母细胞复合体体外减数分裂恢复作用的研究 总被引:1,自引:0,他引:1
本实验利用猪卵母细胞体外无血清培养技术,选用猪卵泡液中自然存在的次黄嘌呤(HX)作为卵母细胞自发成熟的抑制剂,研究了促性腺激素对猪卵丘细胞-卵母细胞复合体(CEO)减数分裂恢复的具体作用。CEO在含有不同浓度的促性腺激素(FSH,hCG,FSH+hCG)的培养液中培养24h,观察卵母细胞减数分裂恢复(GVBD)情况。实验结果如下:1.FSH(1-500IU/L)能够明显刺激CEO克服HX的抑制作用而恢复减数分裂(P<0.05),该作用具有剂量依赖性;2.hCG(1-500IU/L)对CEO减数分裂的恢复无明显作用;3.hCG(10-500IU/L)与FSH(10,100IU/L)无协同作用。上述结果表明,猪CEO减数分裂的恢复可能主要依赖于FSH的作用,该作用能使猪卵丘细胞产生一种或几种阳性因子,作用于卵母细胞,从而克服HX的抑制作用而恢复减数分裂。hCG无明显作用,可能是因为卵丘细胞上没有LH受体或LH受体的数量不足 相似文献
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本实验以酶组织化学方法(SDH、LDH、ACP、ALP)探讨硒对氟引起肾脏损害的拮抗作用。大鼠分为六组,A组常规饮水;B组饮水含亚硒酸钠2mg/L;C组饮水中含氟化钠150mg/L;D、E、F组饮水中分别含氟化钠150mg/L,依次含亚硒酸钠0.5mg/L、2mg/L、4mg/L。8周后断头处死,观察肾脏组织中SDH、LDH、ACP、ALP的活性。结果表明,与A组相比,C组近曲小管SDH、ALP活性减弱,LDH、ACP活性明显增加;B组SDH、ACP活性正常,基底膜清晰;D、E、F组均能提高SDH活性,其中E组较稳定;F组ACP活性较高。结果说明了氟引起肾近曲小管溶酶体的破坏,而硒(2mg/L)能稳定溶酶体膜,拮抗氟对肾脏的损害作用 相似文献
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目的探讨大鼠实验性肝癌发病中刺五加对肌体免疫功能和抗氧化酶活性的影响。方法46只SD雄性大鼠被随机分成对照组(喂普通饲料)、3-甲基4-双甲氨基偶氮苯(3-Me-DAB)组(喂含0.06%3Me-DAB饲料 10周)和刺五加组(饲喂同 3-Me-DAB外、另加入刺五加 4.5g/kg饲料,用常规方法检测全血谷光甘肽过氧化物酶(GSH-PX)、血清超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,用微量化学发光造检测吞噬细胞活性(PMN-CL)。结果1.PMN-CL检测峰值、积分值和吞噬细胞指数,3-MeDAB组较正常组和刺五加组均有显著升高(P<0.05和P<0.01)2.全血GSH-PX活性、SOD活性,刺五加组较3-MeDAB组均有显著升高(P<0.05)。MDA含量刺五加组和3-MeDAB组均较正常组升高(均P<0.05)。结论刺五加在大鼠实验性肝癌诱发过程中有提高抗氧化酶活性和对抗致癌剂引起的机体中性粒细胞吞噬功能代偿性增高的作用。 相似文献
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采用3H-TdR参入法,测定碱性成纤维细胞生长因子(bFGF)、胰岛素和内皮素-1(ET-1)对体外培养的大鼠肾小球系膜细胞(MC)增殖的影响,以及胰岛素与bFGF或ET-1促MC增殖的协同作用。结果表明,不同浓度的bFGF(5-200ng/ml)和胰岛素(0.1-2.4U/ml)均显著升高MC的3H-TdR参入值(cpm值)(P<0.01)。ET-1对MC的cpm值的影响依剂量不同呈现两种不同的效应,在10-9-10-7mol/L时,随着浓度的升高,MC的cpm值明显升高(P<0.01),并以10-8mol/L作用最强;当升高到10-6mol/L时,MC的cpm值出现降低趋势。胰岛素与bFGF或低浓度ET-1(≤10-8mol/L)共同作用于MC时,MC的cpm值明显高于二者单独作用之和(P<0.01),与高浓度ET-1(>10-7mol/L)共同作用于MC时,MC的cpm值小于二者单独作用之和(P>0.05)。上述结果说明,胰岛素、bFGF和ET-1均能显著促进MC增殖;胰岛素与bFGF或低浓度的ET-1促MC增殖具有正协同作用,与高浓度ET-1呈现负协同作用。 相似文献
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利用钙调素calmodulin,CaM)拮抗剂─三氟拉嗪(trifluoperazine,TFP)对G0期小鼠C3H10T1/2成纤维细胞进入S期和DNA合成进行了研究.G0期细胞进入S期时,大量钙调素进入细胞核,其水平为G0期的2倍。TFP处理的细胞被阻抑在G1期,不仅使S期细胞群体下降,而且3H-TdR掺入DNA强度受到明显抑制.同时,TFP处理的细胞胸腺嘧啶核苷激酶(thymidinekinase,TK)基因表达及TK活性亦明显下降,但不影响S期细胞核内的钙调素水平,结果表明钙调素功能之抑制不仅阻抑细胞从G1期至S期的进程,而且对细胞DNA合成强度亦有抑制作用. 相似文献
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Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
采用原位分子杂交方法检测HCV
RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV
RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV
RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV
X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV
C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment. 相似文献