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1.
微小核糖核酸(microRNA,miRNA)在生物体的生长、发育及疾病的发生发展等过程中起着十分重要的作用。目前,人们关注的主要是miRNA在组织细胞内的功能。然而,最近的研究发现血清/血浆中存在一些循环的miRNA,血清/血浆miRNA在肿瘤、糖尿病等多种疾病中呈特异性表达,提示血清miRNA可作为潜在的生物标记物用于疾病的诊断和治疗。  相似文献   

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急性髓系白血病(acute myeloid leukemia,AML)是一类造血干细胞的恶性克隆性疾病,目前的诊断方法不利于疾病的早期发现,且诊断结果重复性较差。已有大量研究显示,细胞外microRNA(miRNA或miR)富集在外泌体(exosome)中,且受其表面膜的保护而具有很好的稳定性,是理想的分子标志物。目前,多种实体肿瘤均已检测到肿瘤特异性外泌体miRNA(exosomal miRNA)。然而,在AML患者中未见此外泌体miRNA报道。本研究探讨急性髓系白血病血浆外泌体miRNA表达谱差异及新miRNA序列。采用solexa高通量测序技术对7例AML患者(AML组)及7例健康对照者(对照组)血浆外泌体miRNAs进行测序,利用Mireap预测软件进行新miRNAs分析,通过edger差异分析软件筛选组间差异miRNA,获得211个已知的差异表达miRNAs以及2个新miRNAs,选择4个差异表达的miRNAs:miR-155-5p、miR-335-5p、miR-451a及xxx-m0038 5p(新miRNA),在两组(各23例)的血浆外泌体样本中,进行实时荧光定量PCR(qRT-PCR)验证,验证结果与测序结果一致。对差异表达的外泌体miRNA进行靶基因预测及其GO(Gene Ontology)和信号通路富集分析,发现靶基因聚集的生物学功能多数参与生物进展过程的调控。靶基因主要富集在FoxO、MAPK、Hippo信号通路以及HTLV-I感染等。结果显示,AML患者与健康对照者的血浆外泌体miRNA存在着差异性表达。差异性表达的miRNA特异性很高,对进一步阐明AML白血病发生与发展的分子机制、研发新的无创诊断方法、新的诊断标记物和有效治疗AML的方法具有十分重要和深远的意义。  相似文献   

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急性心肌梗死(AMI)是最常见的心血管事件,具有高发病率和高死亡率,严重威胁人类生命健康。微小RNA(miRNA)通过调节心肌细胞炎症、纤维化、细胞自噬及新生血管形成的表型机制发挥功能。本综述探讨了心肌梗死后miRNA上调及下调的分子机制,以及miRNA对心肌梗死早期诊断中的价值。  相似文献   

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李之珍  胡晓武  许霞  杨飞  孙晓祥 《生物磁学》2011,(21):4123-4125
目的:探讨糖化血红蛋白(HbAlc)与糖尿病诊断、疗效评价及并发症的关系。方法:选择2型糖尿病患者250例和健康体检者150例,分别测定空腹血糖(FPG)、2h血糖(2hPG)及糖化血红蛋白(HbAlc),统计学分析HbAlc与FPG、2hPG的相关性;分析HbAlc与糖尿病并发症发生的关系。结果:糖尿病组FPG、2hPG及HbAlc水平均显著高于对照组(P〈0.01);糖尿病伴有并发症患者的HbAlc明显高于无并发症者(P〈0.05),HbAlc水平与糖尿病并发症的发生率存在高度相关性(P〈0.01)。结论:检测外周血中HbAlc水平对2型糖尿病诊断、疗效评价具有重要,临床价值,控制糖化血红蛋白对预防糖尿病并发症的发生具有重要意义。  相似文献   

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microRNA(miRNA)在人类恶性肿瘤的发生发展过程中起着重要作用。近期研究表明,miRNA通过结合特定靶标参与调控肝细胞癌(hepatocellularcarcinoma,HCC)的发生,可作为辅助生物标志物用于指导肝细胞癌的诊断和治疗,并为有效地监控和预防肝病提供了新途径。寻找miRNA靶标,阐明miRNA参与肝癌发生的调控机理,有利于肝癌的临床靶向基因治疗。通过总结miRNA在肝细胞癌中的调控机制及临床应用的研究进展,为寻找肝细胞癌早期诊断的生物标志物及介入治疗的靶点提供了参考。  相似文献   

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肺癌是全世界因肿瘤导致死亡的主要原因,虽然肺癌发生的分子机制在基因和蛋白水平上已经得到部分阐明,但死亡率并没有明显改善。microRNA(miRNA)是一类小分子内源性非编码蛋白的RNA,通过与靶mRNA 3'非翻译区(3'-untranslated region,3'-UTR)序列互补配对,产生翻译抑制或者导致RNA的降解来负性调控基因的表达。近来的研究发现有多种miRNA参与肺癌的发生,发展及转移过程,使其可作为生物标志物用于肺癌早期诊断,靶向治疗及预后监测,为肺癌的诊断和治疗提供新的方向。本文就miRNA在肺癌诊断、分型和治疗中的作用进行综述。  相似文献   

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冠心病诊断中最主要的挑战就是从常规的血液样本中鉴定出可靠的临床生物标志物.循环miRNA是一种可以稳定存在于体液中的小分子RNA,具有较高的组织、疾病特异性及敏感性,具有作为新的冠心病非侵入性生物标志物的潜力.通过综述血液样本(全血、血浆、血清、外周血单核细胞(PBMC)、内皮祖细胞(EPC)及血小板)中冠心病相关循环miRNA,及探讨循环miRNA研究中存在的一些问题,为未来筛选出真正具有临床应用价值的循环miRNA生物标志物奠定基础.  相似文献   

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细胞外囊泡(Extracellular vesicles,EVs)是指细胞分泌的双层膜转运囊泡。EVs能从细胞中摄取大分子物质,并将其转移至受体细胞。在这些大分子物质中,研究最多的就是microRNA (miRNA)。miRNA是一种参与基因表达调控的非编码RNA,已证实在哺乳动物卵泡液EVs中有不同的非编码RNA存在,EVs携带miRNA可以作为自分泌和旁分泌的替代机制,影响卵泡发育。文中系统介绍了EVs的种类、特征和分离鉴定方法,重点综述了EVs及携带的miRNA对卵泡发育的作用,包括早期卵泡发育、卵母细胞成熟、卵泡优势化以及对颗粒细胞功能的影响。同时对卵泡液中EVs及其携带的miRNA的未来研究进行了展望,为卵泡液中EVs及携带的miRNA功能的研究及应用提供了思路和方向。  相似文献   

9.
microRNA(miRNA)是进化保守的、非编码单链小RNA,长度约为18-25个核苷酸.作为基因表达的微观管理者,miRNA通过结合在mRNA的3′-UTR抑制翻译过程或使其降解.miRNA多态性是指一类能够干扰miRNA功能的新多态性或单核苷酸的多态性.这种多态性不仅出现在pri-miRNA、pre-miRNA和成熟的miRNA序列中;也可以出现在靶基因3′-UTR;还可以呈现在miRNA基因表观遗传学的改变.miRNA多态性可能导致疾病的产生,也可以判断临床用药疗效及预后监测.目前miRNA多态性正在作为疾病(尤其是肿瘤)生物学研究的强有力工具,而且已应用于疾病的诊断和预后.  相似文献   

10.
microRNA(miRNA)是一类长约22nt(19~23nt)在进化上非常保守的非编码RNA,其能够通过降解mRNA或抑制mRNA翻译来调控蛋白表达。研究证实miRNAs在包括胚胎干细胞分化、单核细胞和巨核细胞生成等血细胞形成过程中扮演重要的角色。而由巨核细胞生成的血小板内同样存在miRNAs,并且被证实参与到血小板活化和血小板生理病理状态改变等过程中。对miRNA调控血小板生成及功能的深入研究将有利于早期诊断治疗血液系统相关疾病。  相似文献   

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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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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   

18.
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   

19.
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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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   

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