细胞增殖与调控机理的研究

细胞增殖是细胞生命活动的重要特征之一。物质准备和细胞分裂是一个相互联系的过程，这一过程即为细胞增殖。细胞增殖是生物繁育的基础。成体生物也需要细胞增殖，以弥补代谢过程中的细胞损失。而细胞增殖受到严密的调控机制所监控，遵循一定的规律，此过程中任何一个关键步骤的错误都有可能导致严重后果，乃至死亡。因此。细胞增殖调控是整个生命活动的最基本保证?     

生命的基础·生命活动的调节--高考生物第二轮复习专题之一

一、高考探究 "每一个生物科学问题的关键必须在细胞中寻找",由于生命活动都是以细胞为单位进行的,生物体的生理活动都与细胞的结构与功能有关,生物体的每一种变化都是分子运动的宏观体现,如自由水和结合水的动态变化反映了细胞与生物体新陈代谢的旺盛程度,蛋白质种类的多样性使生物呈现出多样性,叶绿体的光合作用、线粒体的呼吸作用与生物的能量代谢、遗传信息具有密切的关系,细胞增殖又与"生殖和发育过程"和"遗传变异"有着极其重要的联系.所以本部分内容一般以多知识点、综合题形式出现,主要集中在细胞的亚显微结构和功能、组成生物体的化学元素、化合物及其功能与细胞代谢、遗传变异进化、生态学的关系等方面.     

细胞信号转导作用的研究进展

分别对信号转导在细胞周期、胚胎发育过程及疾病发生机制中的调控作用进行简要综述.细胞信号转导是细胞间实现通讯的关键过程,通过信号分子携带胞内外信息,然后在细胞内传递,进而对细胞生长、发育、增殖分化、遗传、变异、凋亡、迁移及癌变等生命活动进行多层次,多方面的调控.信号转导过程的异常将导致细胞问或细胞内的生命活动动态平街失调,引起疾病的发生.但其调控的具体机制和完整途径有待于借助物理学、化学和分子生物学技术和方法来更深入的研究.     

细胞生命历程之基——“细胞的增殖”主题分析及教学建议

<正> 1 概述细胞像生物体一样,也要经历出生、生长、成熟、繁殖、衰老、死亡的过程。单细胞生物在死亡之前,要通过细胞增殖增加个体数量,以保持物种的延续。多细胞生物的生命历程从受精卵开始,经过细胞增殖、细胞分化,形成组织、器官等,才能发育为完整的生物体。所以说,细胞的增殖是细胞生命历程之基。     

人教版《义务教育课程标准实验教科书·生物学》第二单元教材分析

生物与非生物的本质区别是生物具有生命现象。具体地说,生物能够进行新陈代谢,能够繁殖,有遗传和变异的现象,生物的个体能够从小长大。生物的一切生命活动都是以细胞的生命活动为基础的。通过这一单元的教学应该让学生认识到细胞与生物的关系,意识到科学技术在人类认识生命过程中的重要作用。     

高中生物结论性语句归纳复习

1.从生物的基本特征来看,生物具有共同的物质基础和结构基础。蛋白质是生命活动的主要承担者。细胞是生物体结构和功能的基本单位。2.新陈代谢是生物体进行一切生物活动的基础,是生物最基本的特征,是生物与非生物最本质的区别。但病毒却不能独立完成该过程。     

浅谈配位键与生命活动

<正>生命元素中Fe、Cu、Zn、Mo、Mn、Co等微量元素在生命活动中有很重要的作用.这些金属离子在生物体内主要是通过与生物大分子形成配位键而发挥作用的.关于这些金属离子及其配合物在生物体中的作用,在文献中一般都是分别讨论,没有较系统地论述配位键与生命活动各方面的关系.我们试图通过一系列实例来阐明一些重要的生命活动,如一些物质的运输和贮存,部分酶的催化功能,电子的传递及部分调控蛋白对基因活性的调控等,均依赖于金属离子与生物大分子等配体形成的配位键,这种配位键的破坏均会影响或中止这些生命活动.     

《细胞怎样构成生物体》知识点分析

<正>学习了生物的特征,我们已经知道:除了病毒以外,生物都是由细胞构成的,同时还知道细胞是生命活动的基本单位。在生物圈中,有单细胞个体的存在,也有多细胞的生物。《细胞怎样构成生物体》的内容分别是“细胞通过分裂产生新细胞”“动物体的结构层次”“植物体的结构层次”和“单细胞生物”。下面,我们就一起来了解单细胞生物如何完成各种生命活动的,多细胞生物又是如何构成一个结构复杂的有机整体的。     

细胞分裂周期的研究概况

细胞周期是细胞生命活动的基本过程,由细胞周期素(Cyclin)依次激活相应的细胞周期蛋白依赖激酶(CDK)所推动.对细胞周期调控的研究有助于阐明肿瘤的发生以及终末细胞的分化,将为治疗肿瘤和诱导终末分化细胞的增殖提供有益的思路.     

"核质"式班级管理

接触过生物学的人都知道,生物学中有这样的材料:一个细胞的生命部分包括细胞核和原生质两部分,细胞核包埋于原生质中,并对原生质及整个细胞的生命活动起重要的调控作用,原生质可为细胞核提供必需的物质和能量.一个细胞如果失去细胞核或去掉原生质都会很快失去活力;细胞只有保持完整性,才能正常地完成各项生命活动.根据以上材料可以得出这样的信息:一个真核细胞的生命部分核与质,核决定质的活动但又依赖于质,两者在功能上不可分离、协调一致、紧密相联,细胞才能表现出强大的生命力.     

Parthenolide inhibits proliferation of vascular smooth muscle cells through induction of G0/G1 phase cell cycle arrest

Objective  This study is to determine the effect of the natural product parthenolide, a sesquiterpene lactone isolated from extracts of the herb Tanacetum parthenium, on the proliferation of vascular smooth muscle cells (VSMCs). Methods  Rat aortic VSMCs were isolated and cultured in vitro, and treated with different concentrations of parthenolide (10, 20 and 30 μmol/L). [³H]thymidine incorporation was used as an index of cell proliferation. Cell cycle progression and distribution were determined by flow cytometric analysis. Furthermore, the expression of several regulatory proteins relevant to VSMC proliferation including IκBα, cyclooxygenase-2 (Cox-2), p21, and p27 was examined to investigate the potential molecular mechanism. Results  Treatment with parthenolide significantly decreased the [³H]thymidine incorporation into DNA by 30%∼56% relative to control values in a dose-dependent manner (P<0.05). Addition of parthenolide also increased cell population at G₀/G₁ phase by 19.2%∼65.7% (P<0.05) and decreased cell population at S phase by 50.7%∼84.8% (P<0.05), which is consistent with its stimulatory effects on p21 and p27. In addition, parthenolide also increased IκBα expression and reduced Cox-2 expression in a time-dependent manner. Conclusion  Our results show that parthenolide significantly inhibits the VSMC proliferation by inducing G₀/G₁ cell cycle arrest. IκBα and Cox-2 are likely involved in such inhibitory effect of parthenolide on VSMC proliferation. These findings warrant further investigation on potential therapeutic implications of parthenolide on VSMC proliferation in vivo. Project (No. 491020-W50315) supported by the Foundation of the Health Bureau of Zhejiang, China     

大强度运动过程中的细胞凋亡与基因调控

探讨运动诱导细胞凋亡的基因调控机制。运用文献综述的方法对这一涉及基因调控的分子事件进行探讨。运动训练可引起多种组织细胞的凋亡基因表达发生变化,这一变化可引起细胞发生凋亡和抑制凋亡的发生。同时,细胞凋亡是一个复杂的细胞变化过程,还有多种因素参与了这一过程。     

Min蛋白在原核细胞分裂中的运动模式

Min蛋白以螺旋环的形式在原核细胞两极来回快速的振荡,精确地调控原核细胞的分裂位点。本文对Min白在原核细胞分裂中的运动模式和机理进行了综述,并对未来的细菌细胞生物学研究领域进行了展望.     

Magnetic cell sorting and flow cytometry sorting methods for the isolation and function analysis of mouse CD4＋ CD25＋ Treg cells

Objective: In this paper we compared the two methods of cell sorting (magnetic cell sorting and flow cytometry sorting) for the isolation and function analysis of mouse CD4~+ CD25~+ regulatory T (Treg) cells, in order to inform further studies in Treg cell function. Methods: We separately used magnetic cell sorting and flow cytometry sorting to identify CD4~+ CD25~+ Treg cells. After magnetic cell separation, we further used flow cytometry to analyze the purity of CD4~+ CD25~+ Treg cells, trypan blue staining to detect cell viability, and propidium iodide (PI) staining to assess the cell viability. We detected the immune inhibition of CD4~+ CD25~+ Treg cells in the in vitro proliferation experiments. Results: The results showed that compared to flow cytometry sorting, magnetic cell sorting took more time and effort, but fewer live cells were obtained than with flow cytometry sorting. The CD4~+ CD25~+ Treg cells, however, obtained with both methods have similar immunosuppressive capacities. Conclusion: The result suggests that both methods can be used in isolating CD4~+ CD25~+ Treg cells, and one can select the best method according to specific needs and availability of the methodologies.     

爬行动物行为内分泌学研究进展

爬行动物分布广泛,生殖方式多样,因此其生殖行为和内分泌调节机制也相应的多样化,该领域是近几十年来行为内分泌学研究最多的类群之一。本文总结了近年来国内外爬行动物的生殖方式、行为及其激素调节的机制。爬行动物的生殖周期具有季节性,其调节机制主要有两种:一是垂体激素直接调节生殖系统变化的激活机制的相关研究,另一是神经内分泌机制直接调节季节节律的定时机制。目前,激素与行为关系的研究已经广泛应用于物种保护及推算来自同一物种进化时间等。     

Imbalanced expression of mitogen-activated protein kinase phosphatase-1 and phosphorylated extracellular signal-regulated kinases in lung squamous cell carcinoma

Objective  

Mitogen-activated protein kinases (MAPKs) are correlated with a more malignant phenotype in many cancers. This study was designed to evaluate the predictive value of the expression of MAPK phosphatase-1 (MKP-1) and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK_1/2), as the key regulatory mechanism of the MAPKs, in lung squamous cell carcinoma (SCC).     

运动性骨骼肌微损伤和骨骼肌细胞凋亡的关系探析

细胞凋亡是细胞接受某种信号或受到某种因素刺激后,为了维持内环境稳定而发生的一种主动性消亡过程,但是过度的细胞凋亡与多种疾病有关。运动性骨骼肌微损伤是运动过程中肌肉受到牵拉及肌组织内生理生化环境改变而造成的骨骼肌细胞超微结构的损伤。很多实验表明运动训练开始后骨骼肌内的生理生化环境都会导致骨骼肌细胞凋亡,而且细胞凋亡与运动性骨骼肌微损伤具有相同的时相性,显示凋亡可能是运动性骨骼肌微损伤的一个重要因素,从而探讨运动性骨骼肌微损伤的机制。     

细胞生物学是生命科学的重要基础学科

本综述了细胞生物学研究的内容及其在生命科学中的重要地位。进一步说明了对细胞生物学的研究促进了整个生命科学的发展,同时阐述了当前细胞生物学的特点和主要发展趋势。     

金融体系安全稳定与市场效率的艰难抉择——美国金融监管改革法案的立法过程

美国金融监管改革法案是政府、金融界和社会公众在华尔街金融海啸之后,对美国金融体系深刻反思的结果,是大萧条以来最严厉的金融监管改革法案.该法案旨在强化对商业银行和投资银行、金融衍生工具的交易方式等的监管.美国金融监管改革法案的立法过程,是在金融体系安全稳定与市场效率之间的艰难抉择过程.     

DNA-damage response network at the crossroads of cell-cycle checkpoints,cellular senescence and apoptosis

Tissue homeostasis requires a carefully-orchestrated balance between cell proliferation, cellular senescence and cell death. Cells proliferate through a cell cycle that is tightly regulated by cyclin-dependent kinase activities. Cellular senescence is a safeguard program limiting the proliferative competence of cells in living organisms. Apoptosis eliminates unwanted cells by the coordinated activity of gene products that regulate and effect cell death. The intimate link between the cell cycle, cellular senescence, apoptosis regulation, cancer development and tumor responses to cancer treatment has become eminently apparent. Extensive research on tumor suppressor genes, oncogenes, the cell cycle and apoptosis regulatory genes has revealed how the DNA damage-sensing and -signaling pathways, referred to as the DNA-damage response network, are tied to cell proliferation, cell-cycle arrest, cellular senescence and apoptosis. DNA-damage responses are complex, involving ＂sensor＂ proteins that sense the damage, and transmit signals to ＂transducer＂ proteins, which, in turn, convey the signals to numerous ＂effector＂ proteins implicated in specific cellular pathways, including DNA repair mechanisms, cell-cycle checkpoints, cellular senescence and apoptosis. The Bcl-2 family of proteins stands among ＂the mos＂t crucial regula＂tors of apop＂tosis and performs vi＂tal func＂tions in deciding whether a cell will live or die after cancer chemotherapy and irradiation. In addition, several studies have now revealed that members of the Bcl-2 family also interface with the cell cycle, DNA repair/recombination and cellular senescence, effects that are generally distinct from their function in apoptosis. In this review, we report progress in understanding the molecular networks that regulate cell-cycle checkpoints, cellular senescence and apoptosis after DNA damage, and discuss the influence of some Bcl-2 family members on cell-cycle checkpoint regulation.