衰老机制研究进展

回顾了衰老机制研究发展的主要理论,包括:基因控制理论中的程序性衰老理论;基因组的不稳定性与衰老相关基因的表达;蛋白质与衰老关系中的错误灾变理论;蛋白质在衰老过程中的变化;多基因控制的进化理论;衰老的神经内分泌理论;衰老的免疫理论;生活速率理论;生殖与老化;氧化应激假设。介绍了利用SAM小鼠为动物模型进行衰老机制研究的进展。     

叶片衰老的特性及分子调控（综述）

就叶片衰老研究在生理,生化及分子水平上的最新进展,以及有希望应用于农业,操纵叶片衰老的转基因手段作一简要综述。     

生物体衰老与复制衰老--体内与体外研究

体外连续培养的细胞在有人数的细胞分裂后,更新换代合成ＤＮＡ及分裂的能力,最后导致增殖能力的丧失,但基本代谢过程仍能维持,这种现象称为复制衰老。本文讨论了复制衰老现象存在的普遍性,描述了衰老细胞伯特征,对复制衰老和生物体衰老之间的联系进行了重点分析。现有的研究虽然还不完全,但都提示复制衰老是生物体衰老在细胞水平上的反映,并充分肯定了复制衰老是一个较好的研究机体衰老的模型。     

铁死亡与衰老

铁死亡(ferroptosis)是Dixon等人在2012年首次提出的一种新的细胞程序性死亡方式,它以细胞内铁水平过载和氧化性损伤为主要特征。衰老(aging)是由多种因素共同导致的不可避免的一种生理功能逐渐退化的过程,随着细胞衰老的进行,机体组织器官的生理功能会出现渐进性紊乱和衰退,从而增加机体患病和死亡的风险,例如,神经退行性疾病、癌症和心血管疾病等。目前,已经陆续有学者发现铁死亡与衰老之间存在千丝万缕的联系,特定类型的细胞衰老以及衰老相关疾病有时会伴随着细胞铁死亡的相关特征。但是,铁死亡与衰老之间是否存在因果关系,目前并未定论。本文综述了铁死亡与衰老的特点,并对两者之间的共有特征进行总结,例如,DNA损伤、氧化还原稳态失衡和线粒体功能障碍等。另外,本文还讨论了铁死亡与部分衰老相关疾病的联系,包括帕金森症、阿尔茨海默症,以及部分癌症。本文通过对铁死亡和衰老两个领域之间潜在的联系进行分析和总结,可以为铁死亡与衰老的基础性研究提供新的视角,进而为相关临床疾病的治疗提供有价值的线索。     

运动延缓脑衰老的实验研究

运动是延缓脑衰老的重要手段之一。以“跑转笼”方式建立运动动物模型,用行为学、形态学和生物学研究方法,研究从青年开始的长期运动（８ｍｏ,１９ｍｏ）对运动相关中枢随年龄增加而出现的退行性变化的作用及作用机制。结果表明,长期适量运动能够延缓运动相关中枢随年龄增加而出现的形态结构和功能的退行性变化,通过促进神经元结构代偿而改善神经元功能。     

免疫衰老及免疫细胞在衰老中的作用

人类的衰老是一个复杂的生理过程,是机体随着年龄增长出现生理结构的退行性改变以及机能衰退,表现出机体适应性和抵抗力减退的过程。免疫系统是衰老过程的主要调节系统,免疫衰老会导致机体对病原体和癌细胞的抵抗能力降低,同时伴随相关疾病的发生,如心血管疾病、神经系统疾病及癌症等。本文主要综述了免疫衰老以及免疫细胞在衰老中作用的研究进展,旨在阐明免疫衰老与衰老相关疾病的关系及免疫细胞的抗衰老机制,为精准免疫细胞抗衰老模式提供临床应用的新策略。     

小麦类核糖核酸酶基因（WRN1）cDNA在自然衰老和黑暗诱导衰老条件下的表达

从普通小麦(Triticum aestivum L.)中分离了一个类核糖核酸酶(WRN1)基因的cDNA。WRN1的转录受自然衰老和黑暗诱导衰老的负调控。在幼嫩组织中WRN1也有表达。由于在两个保守的位置上组氨酸被替换,WRNl很可能已经失去了核糖核酸酶的活性。Southern分析表明,在普通小麦基因组中,WRN1以一个小基因家族的形式存在。     

衰老的生物学标志

目前制约哺乳动物衰老研究的一个重要因素就是缺少可靠,易测的评估生物学年龄的衰老标志,本文论述了八项可作为衰老生物学标志的指标及其检测方法,它们是成纤维细胞的体外增殖能力,DNA损伤修复能力,线粒全DNA片段缺失,DNA甲基化水平,端粒的长度,衰老相关β-半乳糖苷酶活笥,晚期糖基化终产物水平,基因表达谱。     

血液衰老:定义与范畴

一般认为,血液老化是人体衰老的根源.血液系统随年龄增长而发生生理性或病理性变化,导致造血干/祖细胞(HSC/HPC)衰老、免疫衰老、炎性衰老等,驱动或参与机体和几乎所有系统/器官的衰老,并引起多种老年性血液系统疾病(特别是恶性肿瘤).虽然“血液衰老(blood aging)”这一名词已在许多论文和日常生活中提及,但尚无确切的定义,其涵盖的领域也不清楚.实际上,随着衰老(包括整体、系统/器官、细胞乃至分子的衰老)研究的迅速拓展和深入,血液衰老的多个方面(如HSC/HPC衰老、免疫衰老、炎性衰老等)已广泛渗透到几乎所有的衰老研究领域,但其本身却迄今未形成一个领域,与迅速发展的临床老年血液学形成了鲜明的反差.因此,本文尝试对血液衰老进行定义(包括生理性和病理性血液衰老),并概要综述了其可能涵盖的范畴(生理性衰老包括HSC/HPC衰老、不同类型血细胞衰老及血液的衰老生物标志物;病理性衰老包括红系、髓系、淋系、巨核细胞/血小板的老年性良性疾病或恶性肿瘤,以及老年患者的衰弱及其评估),供学者们讨论.     

JAK-STAT信号通路与衰老及衰老相关疾病

老龄化是许多慢性疾病的首要危险因素.如果老年人的疾病预防水平得不到大幅度的提高,不仅会影响老年人及家庭成员的生活质量,还会导致国家的经济以及医疗资源严重的匮乏.因此,如何延缓衰老已成为全世界关注的焦点.近些年,对衰老相关的机制也进行了广泛的研究,其中JAK-STAT信号通路吸引了大量学者的眼球.但是对JAK-STAT信...     

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.