树突状细胞在AIDS灵长类动物模型疾病进程中的作用

非人灵长类动物模型在艾滋病(AIDS)发病机制、传播途径、疫苗和药物等方面的研究中具有重要作用。树突状细胞(DC)作为最重要连接先天免疫与获得性免疫的抗原递呈细胞,在AIDS发病进程中扮演着重要的角色。研究非人灵长类AIDS动物模型中DC亚群数量、表型以及功能的变化,对揭示AIDS发病机制具有十分重要的意义。该文将重点总结近些年来DC亚群在AIDS动物模型发病机制中的作用研究进展,为以后的研究提供思路。     

提前接受光照对小鼠视网膜TH和bFGF表达的影响

目的在通过手术使小鼠提前睁眼接受光照,并成功诱发近视的基础上,进一步研究TH和bFGF在视网膜中的表达变化,以探讨早产近视的发病机理.方法实验用新生第4d的C57BL/6J小鼠,通过手术分离单侧上、下眼睑,使之提前睁眼并接受正常光照,在第14d检查两眼屈光力,应用RT-PCR和免疫组化方法,检测视网膜中bFGF和TH的表达.结果提前接受光照能诱导形成-9.77±0.09D的相对近视.RT-PCR结果显示提前光照小鼠视网膜TH和bFGFmRNA含量明显减少(t值分别为4.316和12.189,P<0.01).免疫组织化学显示TH免疫阳性反应主要分布在节细胞层、内网层和内核层,bFGF免疫阳性反应主要分布在内网层及其两侧的部分节细胞和内核层细胞,另在内网层和视锥视杆层也有微弱表达.免疫组织化学染色显示提前光照小鼠视网膜中TH和bFGF的表达量明显下降.结论研究表明新生小鼠提前光照后,其视网膜TH和bFGF的表达都明显下降,提示TH和bFGF与早产近视的形成有密切关系.     

眼色素层炎的免疫机制及免疫治疗

眼色素层由脉络膜、睫伏体、虹膜组成。这些部位的炎症反应称眼色素层炎。眼内的炎症主要有两类：抗原特异性免疫应答介导;非特异性炎症反应。本文重点综述抗原特异性免疫应答介导的眼色素层炎的发病机制及免疫治疗。过去认为梅毒螺旋体、结核杆菌是大多数眼色素层炎的病因,近几年来大量实验和临床研究证实,免疫应答在感染性和非感染性眼色素层炎的发生中起重要作用,对其机制有更深入的了解,以Ｔ 细胞介导的细胞免疫为主要损伤机制,根据免疫机制的各个环节建立了新的免疫治疗方法,包括环孢素Ａ 免疫抑制剂的使用、口服耐受的诱导以及细胞粘附分子疗法。     

Th17/Treg 细胞在银屑病的发病机制研究进展

Th17细胞和Treg细胞是CD4+T细胞在不同细胞因子环境中分化出的新亚群,发挥不同的生物学效应,使机体的免疫系统处于平衡状态.Th17/Treg细胞失衡可引起一系列自身免疫性疾病.银屑病是与遗传、免疫异常有关的皮肤炎症性疾病,其发病机制尚不清楚.越来越多的研究发现,Th17细胞增多和Treg细胞减少及其分泌的细胞因子在银屑病的发病中有着重要作用.本文围绕这一机制综述了近年来有关Th17细胞、Treg细胞在银屑病发病机制中作用的研究,帮助我们更深入地了解银屑病的发病机制并为今后临床诊断和治疗提供依据.     

IL-21/IL-21R信号在IBD病变形成机制中作用的研究进展

炎症性肠病(Inflammatory bowel disease,IBD)的发病机制至今尚不明确,普遍认为是由肠黏膜免疫调节异常、持续性肠道感染、肠黏膜屏障缺损、遗传和环境等多种因素相互作用导致的。近年来,研究发现IBD患者血清中IL-21水平异常升高,提示IL-21/IL-21R信号可能在IBD的病变形成中发挥重要作用。IL-21是一种重要的具有多重生物学功能的细胞因子,通过对CD4+T细胞、CD8+T细胞、Th17细胞、B细胞、巨噬细胞、树突状细胞等多种细胞产生影响,从而参与IBD的发生发展。本文就IL-21/IL-21R信号在炎症性肠病发病机制中的研究进展进行综述。     

MicroRNA在子宫肌瘤发病机制研究中的现状

微小RNA(micro RNA,mi RNA)是一类非编码单链小分子RNA,参与调控细胞增殖、分化、凋亡及迁移等多种生理过程。最新研究发现,mi RNA在子宫肌瘤发生发展中的细胞转化、组织重构、血管生成及炎症反应等方面均起着重要调控作用。这提示,mi RNA不但可以作为探索子宫肌瘤发病机制的新途径,而且可能成为子宫肌瘤诊断、治疗和预后判断的新靶点。该文就近年来mi RNA在子宫肌瘤发病机制研究中的现状进行综述。     

自噬在2 型糖尿病和胰岛β 细胞中作用研究进展

胰岛素分泌缺陷和胰岛素抵抗是2型糖尿病发病的主要机制之一。高血糖和脂质代谢紊乱,是糖尿病发病机制中最重要的获得性因素。最近研究表明自噬在维持内环境稳定,胰岛β细胞数量分泌能力,及对抗胰岛素抵抗等方面有重要作用。本文就自噬的基本概念及在糖尿病发病和维持β细胞功能方面作一综述。     

光学相干断层成像术在近视眼视网膜神经纤维层厚度测量中的临床应用

目的:研究光学相干断层成像术(OCT)在近视眼视网膜神经纤维层(RNFL)厚度测量中的应用价值。方法:选择2016年1月到2016年5月在医院就诊的近视患者73例(138眼)纳入此次研究,根据近视情况将患者分为低度近视组(-0.30D~-3.00D)共26例(48眼)、中度近视组(-3.01~-6.00D)共24例(47眼)及高度近视组(-6.00D)共23例(43眼)。另选同期在医院体检(视力正常)的健康志愿者25例(45眼)作为对照组,对比各组不同象限的RNFL厚度,屈光度及眼轴长度,分析近视眼各象限的RNFL厚度与患者屈光度和眼轴长度的相关性。结果:高度近视组的上方象限、下方象限以及鼻侧象限的RNFL厚度均明显低于对照组及中度近视组,中度近视组的下方象限及鼻侧象限的RNFL厚度均明显低于对照组,低度近视组鼻侧象限的RNFL厚度明显低于对照组,差异均有统计学意义(均P0.05)。近视组的屈光度及眼轴长度均明显大于对照组,且高度近视组均明显大于中度近视组与低度近视组,中度近视组均明显大于低度近视组,差异均有统计学意义(均P0.05)。根据Pearson法分析相关性可知,近视眼患者上象限、下象限、鼻侧象限的RNFL厚度与其屈光度及眼轴长度均呈负相关。结论:利用OCT技术检测近视眼RNFL厚度时,应考虑屈光度及眼轴长度可能造成的影响,综合进行分析判断,以获得最佳检测数值。     

重复低能量红光干预改善青少年近视的研究现状

近视作为眼科最常见的疾病已经发展成一项严重的国际化公共健康负担,发展形势不容乐观,有必要提出新的有效的干预措施,以遏制近视流行的浪潮。近几年,红光干预延缓近视进展成为新的研究热点。本文从近视的流行现状、近视的诱因入手,简要介绍目前临床常用治疗手段,总结红光干预近视的研究现状,讨论红光干预改善近视可能的机制机理,并提出一些潜在的激光安全问题,希望能够对未来的相关研究提供参考。     

细胞自噬在多发性硬化中的作用

多发性硬化(multiple sclerosis,MS)是一种以白质脱髓鞘、胶质细胞增殖、轴突损伤和进行性神经功能障碍为主要特点的中枢神经系统慢性炎症脱髓鞘疾病,其病因和发病机制尚未完全明确。既往在对MS及其动物模型实验性自身免疫性脑脊髓炎的研究中发现了细胞自噬也参与了其发病,涉及到的主要有T淋巴细胞、B淋巴细胞、小胶质细胞、少突胶质细胞、星形胶质细胞、树突状细胞、神经元。因此,本文将对以上细胞自噬在MS中的作用进行综述,以期为研究MS的发病机制和治疗研究提供参考。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

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.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

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     

Selection with two alleles and complete dominance

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.