维生素E和微量元素Se对人肝癌细胞生长,分化及其癌基因…

本工作观察了体外环境中不同水平的维生素Ｅ和微量元素Ｓｅ对人肝癌细胞株（ＳＭＭＣ－７７２１）生长,分经和其癌基因（Ｎ－ｒａｓ,ｃ－ｍｙｃ）表达水平的影响,实验结果表明：高水平维生素Ｅ（２．４、９．２、２４：０ｎｍｏｌ／Ｌ）和Ｓｅ（０．１５,０．３０,０．６０ｎｍｏｌ／Ｌ）对肝癌细胞的集落形成率具有明显的抑制作用;生化分析显示高水平维生素Ｅ微量元素Ｓｅ均可明显抑制环境中脂质过氧化的水平,Ｓｅ对癌细胞甲     

维生素C对黄瓜叶绿体膜脂过氧化的影响

研究了外源维生素对黄瓜叶绿体膜脂过氧化的影响。结果表明,黄瓜叶绿体内过量的维生素Ｃ导致了叶绿体膜的伤害,加剧了叶绿体膜脂过氧化程度,其原因可能是外源维生素Ｃ加快了叶绿体的电子传递速率,从而造成超氧物阴离子自由基的产生速率升高。     

Fe（Ⅱ）离子所引发的羟自由基对人红细胞膜的作用

Ｆｅ（Ⅱ）离子所引发的羟自由基对人红细胞膜的作用薄云红,徐轶,王夔（北京医科大学药学院,北京１０００８３））在人体内由铁催化产生的·ＯＨ会引发脂质过氧化链式反应,而且在维生素Ｃ（Ｖｃ）存在下其过氧化程度加剧,导致红细胞膜构象改变［１］。血红素是一种富...     

EPC—K1防止ONOO^—诱导的小脑颗粒神经元凋亡

荧光显微镜观察及ＥＬＩＳＡ分析表明１０μｍｏｌ／Ｌ过氧化亚硝基可诱导原代培养的大鼠小脑颗粒神经元凋亡。应用ＥＳＲ自旋标记技术研究了这一过程中细胞膜生物物理特性的变化,结果表明神经细胞经过氧化亚硝基处理后,细胞膜表层及深层流动性均显著下降,膜蛋白巯基强弱固定化比值增加,维生素Ｃ、维生素Ｅ的衍生物Ｌ－抗坏血酸２－（３,４－二氢－２,５,７,８－四甲基－２－（４,８,１２－三甲基十三烷基）－２Ｈ－１－苯     

亚油酸体系脂质过氧化起动机理的ESR研究

本研究直接用含两个双键的不饱和脂肪酸一亚油酸(LH)作为模型化台物,利用自旋捕集ESR技术鉴测脂质过氧化反应的中间自由基L·.研究结果表明:0H自由基,H O,0(?)自由基都不能起动亚油酸的过氧化,即使这种亚油酸含有过氧化成份-LOOH.Fe(Ⅱ)和Fe(Ⅲ)都能使含有过氧化成份的亚油酸产生进一步的过氧化,但不能起动纯的亚油酸的过氧化.     

维生素C可防止香烟所致的白细胞粘附

维生素Ｃ可防止香烟所致的白细胞粘附美国《国家科学院学报》（ＰＮＡＳ）最近报道,维生素Ｃ可防止香烟对仓鼠的某些有害影响。以往研究证明,抗氧化剂维生素Ｃ、维生素Ｅ和丙丁酚（ｐｒｏｂｕｃｏｌ）可消除血中高活性自由基,从而防止动脉粥样硬化（ＡＳ）。但最近的两...     

维生素E和微量元素Se对人肝癌细胞生长、分化及其癌基因表达的影响

本工作观察了体外环境中不同水平的维生素Ｅ和微量元素Ｓｅ对人肝癌细胞株（ＳＭＭＣ－７７２１）生长、分化和其癌基因（Ｎ－ｒａｓ、ｃ－ｍｙｃ）表达水平的影响。实验结果表明：高水平维生素Ｅ（２．４、９．２、２４．０ｎｍｏｌ／Ｌ）和Ｓｅ（０．１５、０．３０、０．６０ｎｍｏｌ／Ｌ）对肝癌细胞的集落形成率具有明显的抑制作用;生化分析显示高水平维生素Ｅ和微量元素Ｓｅ均可明显抑制环境中脂质过氧化的水平,Ｓｅ对癌细胞甲胎蛋白的分泌有明显的抑制作用,而维生素Ｅ作用不明显。细胞原位杂交发现维生素Ｅ浓度为２．４和９．２ｎｍｏ１／Ｌ时对细胞癌基因Ｎ－ｒａｓ的表达具有明显抑制作用;Ｓｅ浓度为０．１５和０．３０ｎｍｏｌ／Ｌ时对癌基因ｃ－ｍｙｃ的表达明显抑制。实验还观察了维生素Ｅ和Ｓｅ之间的叠加效应,结果显示除对环境中脂质过氧化的抑制作用具有叠加效果外,对其他指标没有明显作用。     

3′－大豆苷元磺酸钠的体外抗氧化研究

为研究3′-大豆苷元磺酸钠（DSS）的体外抗氧化活性,测定了DSS对超氧自由基（02·）、羟基自由基（·OH）和1,1-二苯基-2-苦苯肼自由基（DPPH·）的清除能力,及其对Fe^2＋诱导的脂质过氧化反应和β-胡萝卜素／亚油酸自氧化体系的抑制作用。结果表明,DSS对DPPH·有一定的清除能力,对超氧自由基的清除能力较强,能很好地清除·OH自由基,对脂质过氧化有一定的抑制作用,对β-胡萝卜素／亚油酸自氧化体系有明显的抑制作用。说明DSS的药理作用可能与其较强的抗氧化能力有关。     

三硝基甲苯致晶体氧化损伤的研究

采取大鼠晶体外培养的方法,动态观察了在三硝基甲苯作用下,晶体中脂类过氧化、维生素Ｃ含量及超氧化物坡化酶活性的改变,并与对照组进行比较。发现随着三硝基甲苯作用时间的增加,晶体中脂类过氧化增高;维生素Ｃ含量呈下降趋势;超氧化物歧化酶活性在第１天升高,第５天下降。     

三硝基甲苯致晶体氧化损伤的研究

采取大鼠晶体体外培养的方法,动态观察了在三硝基甲苯作用下,晶体中脂类过氧化、维生素Ｃ含量及超氧化物歧化酶活性的改变,并与对照组进行比较。发现随着三硝基甲苯作用时间的增加,晶体中脂类过氧化增高;维生素Ｃ含量呈下降趋势;超氧化物歧化酶活性在第１天升高,第５天下降。     

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.