基因定位修复技术——嵌合修复术（chimeraplasty）

传统的以病毒DNA为载体的基因治疗方法存在病毒导入的靶向性差、整合位点的特异性差、基因剂量的可控性差以及病毒载体具有一定的免疫原性的缺点,而实际上许多单基因遗传病只要将突变的单个碱基校正就能达到基因治疗的目的,不必置换或整合入整个基因.嵌合修复术(chimerplasty)是近年来迅速发展起来的一种基因定位修复技术,该技术利用RNA/DNA嵌合体分子与要修复的宿主染色体DNA碱基序列互补而精确定位并原位修复,也可用于人工定点突变,已在单基因遗传病的基因治疗及植物遗传改良等方面获得了成功的应用.介绍了该技术的原理、应用举例及前景.     

人类胚胎单碱基编辑治疗遗传疾病的研究

基因编辑技术是当今生物学研究领域最为重要的颠覆性技术之一,以CRISPR/Cas9系统为核心的基因编辑工具被广泛应用于包括人类体细胞、生殖细胞编辑相关的医学研究领域。虽然CRISPR/Cas9系统可以高效编辑靶基因,但其精准编辑能力依赖于效率极低的同源重组方式,这极大限制了其定点编辑的能力与应用范围,所以寻找一种能高效引入点突变的新型基因编辑工具具有重大的应用价值。以CRISPR/Cas9系统为基础的单碱基编辑系统可以在基因组靶位点实现精准、高效的C/G和T/A碱基间的转换,其编辑能力已经在动植物、人体细胞以及人类胚胎中得到证实。利用单碱基编辑技术,有望对人类超过70%的相关遗传性致病位点进行修复。现就人类胚胎单碱基编辑治疗遗传疾病的最新研究进展进行综述和展望。     

基因编辑猴模型及其在基因治疗研究中的应用前景

基因编辑技术的开创性进展使得利用CRISPR技术建立猴模型并开展病变基因校正成为目前基因治疗研究领域的热点。非人灵长类与人类在进化关系上最为接近,在模型构建、疾病机制研究以及药物研发方面优势突出。随着基因修饰技术在非人灵长类上的逐步应用,目前已经构建出多种与临床患者病症高度吻合的疾病模型,为开展遗传疾病的基因治疗打下了坚实基础。然而,目前基因递送和基因修复系统面临巨大挑战,能否安全、高效、精确地修复致病基因是基因治疗临床转化的关键问题,现将综述基于猴模型开展基因治疗研究的前景及挑战。     

基因编辑技术及其在疾病治疗中的研究进展

基因编辑是一种基于人工核酸酶的遗传操作技术,能精确地对DNA或RNA进行高效改造。基因编辑除了在基础研究、生物育种和药物筛选等方面展现了巨大前景之外,在疾病治疗(特别是基因遗传病)领域的前景与进展尤为引人注目。本文在介绍基因编辑技术的发展及其在疾病治疗中不同策略的基础上,重点围绕遗传疾病的基因治疗研究,综述了基因编辑技术(包括单碱基编辑和表观调控等技术)在血液系统、肝脏、肌肉和神经系统等疾病治疗的研究进展,并对基因编辑治疗疾病的未来发展进行了展望。     

基因治疗

据人类遗传学家Mckuscikl981年的统计,已知的遗传病有3000多种,全世界受遗传病为害的人大约占人口的15％。就目前科学发展的水平来说对遗传病的治疗方法有环境工程和遗传工程两种方法,环境工程是在遗传病已形成,临床症状尚未出现或发病早期进行治疗,这种方法未干涉到致病基因,只能治其表而不能治其本。遗传工程(即基因治疗)则可人为地改变致病基因,从根本上消除遗传病。     

基于CRISPR/Cas系统的DNA碱基编辑研究进展

基于CRISPR/Cas的基因编辑是近年发展起来的一项变革性生物技术。其过程包括在目标DNA位点引入双链断裂(double strand break,DSB)以及其后续的细胞修复。细胞修复DSB主要有两种方式：非同源末端连接(non-homologous end joining,NHEJ)以及同源重组介导的修复(homology-directed repair,HDR)。前者是大多数细胞修复DSB的主要方式,其特点在于修复简单、效率高但极易出错,往往会引发难以预测的核苷酸插入或删除。点突变是自然界中最常见的遗传突变类型,引起了超过半数的人类遗传疾病以及许多重要农艺性状变异。碱基编辑能够实现单个碱基的替换,既不需要引入DSB,又无需修复模板参与,具有高效、编辑结果可控等优点,在基因治疗、作物育种及生物技术研究等方面具有重大的应用潜能。自首个碱基编辑工具开发以来,碱基编辑相关技术得到快速发展及广泛应用。本文综述了目前DNA碱基编辑研究进展,重点阐述了碱基编辑器及其在编辑效率、精度以及特异性提高和编辑范围扩展等方面的最新进展以及仍存在的瓶颈,并展望其研究和应用前景。     

基因编辑技术在β-地中海贫血治疗中的研究

β-地中海贫血(β-地贫)是一种全球性的单基因遗传病，目前针对该病的治疗方法除造血干细胞移植外都是对症治疗，无法达到根治效果。基因治疗是指将外源正常基因导入靶细胞，以纠正或补偿缺陷和异常基因引起的疾病，达到根治疾病的目的。近年，随着基因编辑技术的发展，基因治疗越来越成熟完善，在β-地贫治疗中的应用也变得广泛。目前，基因编辑技术发展经历了4个阶段，分别为ZFN技术、TALEN技术、CRISPR/Cas9技术以及单碱基编辑技术。本综述将总结上述4种基因编辑技术在β-地贫治疗中的原理、研究、优缺点以及局限性，旨在优化β-地贫的治疗策略。     

CRISPR/Cas9系统应用于早期胚胎编辑和基因治疗

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9)系统具有高效、精确、操作难度较低等特点,是目前应用最为广泛的基因编辑工具。CRISPR/Cas9在构建模式动物突变体研究基因功能和构建人类疾病模型中有大量使用,但是由于相关伦理限制,在人类胚胎中进行基因编辑来探索治疗性胚胎编辑和研究人早期胚胎发育机制的研究发展较慢。人类胚胎发育机制与小鼠等模式动物的早期胚胎发育机制存在较大差异,过往在模式动物上研究的早期胚胎发育机制要在人类胚胎水平进行验证,对人类胚胎利用基因编辑工具进行直接研究越发必要,探索人类早期胚胎发育机制有助于相关发育疾病的研究与治疗。胚胎治疗性基因编辑可以实现对遗传疾病的彻底阻断,目前还处于初步探索时期,但是主要存在潜在脱靶和编辑后形成嵌合体两方面问题。相较而言,出生后个体水平的基因治疗目前发展较为快速,对遗传疾病和艾滋病等血液疾病有应用价值。现对CRISPR/Cas9近年来应用于人类胚胎编辑和基因治疗的内容进行了综述。     

利用CRISPR/Cas系统对血友病B小鼠进行基因纠正的初步探索

血友病B是人类常见的X染色体遗传的隐性遗传疾病,目前对于遗传疾病的治疗还没有很好的办法,通过基因治疗可以实现对遗传病的彻底治愈。本研究利用高效基因编辑技术CRISPR/Cas系统,对血友病B小鼠尝试基因修复进行初步的探索,将突变的凝血因子IX(Factor IX,FIX)基因进行同源替换,修复为正常序列。本研究中将同一种纯合突变类型的小鼠交配之后得到的受精卵,进行细胞核显微注射。对收集到的8枚囊胚的基因组中的靶位点,进行巢氏PCR扩增,直接进行测序检测基因型序列。检测结果为4枚囊胚的基因被成功编辑,其中3枚囊胚为靶序列的基因敲除突变,而有1枚囊胚成功进行同源重组,实现基因纠正。     

遗传病的生物治疗

遗传病尤其是单基因遗传病是儿童致畸致残的主要原因之一,给家庭、社会带来沉重的经济、心理负担。目前绝大多数遗传病临床治疗以对症治疗为主,尚缺乏有效的治疗方法。随着生命与医学科学的发展,近年来以靶向致病分子或其相关信号通路、靶分子的外源物质补充、转基因、RNA干扰、基因组编辑等生物学技术为代表的生物学治疗措施开始应用于遗传病的治疗,并取得了一定的疗效。但目前大多数遗传病的生物学治疗仍局限于动物实验研究,今后在继续研发基于致病机制的新治疗策略的同时,将关注如何开展临床试验,为最终安全、有效应用于临床患者奠定基础。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

激光联合注射曲安奈德治疗婴幼儿血管瘤的疗效分析

目的：分析激光联合注射曲安奈德治疗婴幼儿血管瘤的疗效。方法：将120例处于增殖期血管瘤患儿分成观察组和对照组各60例,观察组给予激光联合注射曲安奈德治疗,对照组采用激光治疗,比较两组患者的治疗疗效。结果：观察组和对照组的总有效率分别为96．7％和66．7％,两组比较具有显著差异,P〈0．05;对于表浅病灶,观察组治疗的有效率为96．8％,对照组为84．8％,两组之间无差异,P〉0．05;对于深部病灶,观察组和对照组的总有效率分别为96．6％和44．4％,具有显著差异（P〈0．05）。结论：激光联合注射曲安奈德治疗婴幼儿血管瘤具有较好的疗效,尤其对深部增殖期的血管瘤具有较好的效果,适合在临床推广应用。     

Areography of the Gymnosperms of China (1) Distribution of the Pinaceae of China

Nine of 10 genera and 119 of approximately 240 species of the Pinaceae occur in China, including 67 endemic species and two endemic genera. In this paper, the distributional maps of all the genera of the Pinaceae are presented (fig. 1-8). The horizontal and vertical distributions of species in each genus are discussed. The analysis of the distribution patterns of the genera indicates that some genera, such as Keteleeria, Tsuga, Pseudotsuga, Cathaya and Pseudolarix, are restricted to the area south of the Qinling Mountains and the Huaihe River, and the others, i. e. Picea, Abies, Larix and Pinus, extend northward to northeastern China. However, all of the genera except Keteleeria and Pinus are not found in very dry areas and tropical mountainous regions of China. The monotypic genera, Cathaya and Pseudolarix, are distributed in eastern and central China. The genus Keteleeria consists of 10 species, 7 of which are concentrated in southern Guizhou, northern Guangxi, southwestern Hunan and easternmost Yunnan. The distribution of the remaining 6 genera shows the maximum concentration in western Sichuan and northwestern Yunnan. (Figs. 2-8). Furthermore, more than third of species of the Pinaceae (37.8%) are also concentrated in western Sichuan and northwestern Yunnan. where a great variety of habitats and different topographic features occur. It is apparent that to conduct our systematic and evolutionary studies on this family in these region is especially needed. The relations between the areal size and the tolerance of species are discussed. The distributions of macrofossils and microfossils of the genera of the Pinaceae ia China are given, and it has been proved that areas of most genera of the family were considerably larger in the past. than at present.     

Definition of the site of reactivity of the ancestral protease of the papain type

Digestions of oxidized insulin B chain by the sulfhydryl proteases papain, chymopapain, papaya peptidase A, actinidin, bromelain, ficin and asclepains     

青蒿素生物合成机理研究现状

本文总结了目前有关青蒿素生物合成机理方面的研究,主要包括青蒿素生物合成中生理因子的影响,青蒿素生物合成中间体及前体,青蒿素生物合成细胞定位等。指出了存在的一些问题及今后的研究发展前景。     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

析遗传密码子多态性之谜

建立了1个由16个“3读2”原始密码子组成的系统。它们分为“语义确切”的,和“双义的”,两大类。后者,通过不同的分化方式,进一步分化为语义确切的“3读3”现代密码子;前者则无需再分化,仍保留着“3读2”原始形态,成为孑遗密码子。首次解释了氨基酸具有不同数目密码子,以及线粒体内存在反常密码子的多态性现象,初步建立了密码子进化树,并提出了原始氨酰基－tRNA合成酶可能在密码子进一步分化中起关键作用的观点。     

Locations of Remorse and Homelands of Resilience: Notes on Grief and Sense of Loss of Place of Latino and Irish-American Caregivers of Demented Elders

In this essay, based on qualitative research with Latino and Irish-American caregivers of demented elders, we argue that spatially and culturally constituted definitions of personhood, the moral life, and justice shape perceptions of normative aging, the agency of the demented persons and their place in the community, the appropriate care of the aged and demented, as well as partially determine the concrete resources which will be available to elders and their families. We review how ties to homelands and neighborhood institutions act as mediators and shapers of anticipatory grief, caregiver burdens, and caregiver resources, serving as a buffer against exhaustion and despair for some families (primarily the Irish-American sample), and as an additional site of loss or stress for others (primarily the Latino sample).