兔肝金属硫蛋白结合铅离子的圆二色性光谱研究

从锌诱导的家兔肝脏中分离纯化得到金属硫蛋白两种亚型：ＺｎＭＴ－Ⅰ和ＺｎＭＴ－Ⅱ．在酸性条件下脱金属,经Ｓｅｐｈａｄｅｘ Ｇ－２５柱层析得到脱金属硫蛋白（ａｐｏＭＴｓ）．用圆二色性（ＣＤ）光谱法研究,发现两种亚型ａｐｏＭＴｓ 与Ｐｂ２＋ 的结合依赖于Ｐｂ２＋ 的加入比例及ｐＨ 值．ａｐｏＭＴ－Ⅰ在ｐＨ３～５之间,ａｐｏＭＴ－Ⅱ在ｐＨ４～６之间与Ｐｂ２＋ 结合形成特征簇合物Ｐｂ７ＭＴｓ,其ＣＤ谱图特征峰位于３１６ｎｍ （－ ）,２７０ ｎｍ （＋ ）,２４５ ｎｍ （＋ ）及２２５ ｎｍ （－ ）,提示解铅中毒的最佳条件应控制在弱酸性环境．不同亚型ａｐｏＭＴｓ 与Ｐｂ２＋ 的结合方式各不相同：Ｐｂ２＋ 与ａｐｏＭＴ－Ⅰ的结合采取平均分配的方式,而与ａｐｏＭＴ－Ⅱ则为选择性结合方式,表明这两种亚型在解铅毒功能上存在差异．     

脱金属硫蛋白与镉离子的络合作用及构象研究

用圆二色（ＣＤ）谱地研究兔肝脱金属硫属蛋白的两个亚型与Ｃｄ＾２＋的络合作用及对重组ＭＴ构象的影响。观测了ａｐｏ－ＭＴ垢巯基在空气和室温下的稳定性。在ＰＨ４．７１,镉重组ＭＴ１的ＣＤ谱特征峰在２５７ｎｍ（＋）,２３８ｎｍ（－）,２２６ｎｍ（＋）与镉诱导的天然ＭＴ１相同。在空气存在和ＰＨ７．９０的ＣＤ谱只有２４３ｎｍ（＋）一个峰。向两亚型分别加入７ｅｑＣｄ＾２＋测定ＣＤ谱随ＰＨ值的变化,发现在ＰＨ２．     

宫粉郁金的组织培养和快速繁殖

１植物名称宫粉郁金（Ｃｕｒｃｕｍａ　ｋｗａｎｇｓｉｅｎｓｉｓ）。２材料类别　块茎萌动芽。３培养条件　萌动芽生长培养基：（１）ＭＳ＋６－ＢＡ１ｍｇ·Ｌ－１（单位下同）＋ＮＡＡ０．２。不定芽增殖与愈伤组织诱导培养基：（２）ＭＳ＋６－ＢＡ１０＋ＫＴ５;（３）ＭＳ＋６．ＢＡ１０;（４）ＭＳ＋６－ＢＡ５＋ＫＴ２．５;（５）ＭＳ＋６－ＢＡ５;（６）ＭＳ＋６－ＢＡ２＋ＫＴ１。生根培养基：（７）ＭＳ＋ＮＡＡ０．５;（８）ＭＳ＋６－ＢＡ０．５＋ＮＡＡ０．５;（９）ＭＳ。以上培养基均加０．７％琼脂,３％蔗糖,ｐＨ５…     

增强UV—B辐射对蚕豆叶片微粒体膜一些性质的影响

温室条件下,用０,８．６５ｋＪｍ＾－２ｄ＾－１及１１．２ｋＪｍ＾－２ｄ＾－１不同剂量的ＵＶ－Ｂ辐射处理蚕豆幼苗。Ｃａ＾２＋－ＡＴＰａｓｅ及Ｍｇ＾２＋－ＡＴＰａｓｅ的活性在辐射处理期间下降。在处理２１ｄ,Ｔ１和Ｔ２微粒体膜的ＭＤＡ含量明显高于对照,同时ＩＵＦＡ急剧下降,且呈明显的剂量效应。     

水分胁迫下钙螯合剂与CPZ抑制剂对棉花根和下胚轴两种ATPase…

水分胁迫下棉花根和下胚轴质膜Ｈ＾＋－ＡＴＰａｓｅ和Ｃａ＾２＋－ＡＴＰａｓｅ活力,表现Ｋｍ值以及Ｖｍａｘ降低。－０．３ＭＰａ和－１．１ＭＰａ胁迫下质膜ＡＴ－Ｐａｓｅ活力随时间延长分别呈“Ｖ”字形变化和下降趋势。钙螯合剂、ＣａＭ抑制剂对棉花根和下胚轴质膜ＡＴＰａｓｅ活性有明显的抑制效应,抑制程度为－１．１ＭＰａ大于－０．３ＭＰａ大于对照。     

转金属硫蛋白突变体αα的烟草具有较高的重金属抗性

金属硫蛋白（ＭＴ）有α、β两个结构域,其中α结构域优先结合Ｃｄ＾２＋、Ｈｇ＾２＋以α结构域代替β结构域而得到的αα突变体在大肠杆菌构建及表达后,体外实验证明其具有同天然ＭＴ相似的稳定性,但结合重金属的能力稍强于天然ＭＴ。将αα突变体转入植物表达载体,以ＣａＭＶ３５Ｓ为启动子,利用根癌土壤杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍ ｔｕｍｅｆａｃｉｅｎｓ（Ｓｍｉｔｈ ｅｔ Ｔｏｗｎｓｅｎｄ）Ｃｏｎｎ）介导的叶     

矮生鸡冠花的离体快繁及试管苗开花

１植物名称矮生鸡冠花（Ｃｅｌｏｓｉａｃｒｉｓｔａｔａ）。２材料名称无菌种子苗顶芽、腋芽。３培养条件基本培养基为ＭＳ。培养基组合为：（１）ＭＳ＋ＢＡ１－２ｍｇ·Ｌ~（－１）（单位下同）＋ＮＡＡ０．１～０．２;（２）ＭＳ＋ＢＡ２＋ＩＡＡ０．２;（３）ＭＳ＋ＫＴ２;（４）ＭＳ＋ＢＡ０．１～０．５。以上培养基均含３％蔗糖,０．６％琼脂,ｐＨ为５．８,培养温室为（２６±２）℃,光照１２ｈ．ｄ~（－１）（２０００ｌｘ）。４生长与分化情况４．１无菌材料的获得成熟的种子置７０％酒精中摇动５０ｓ后,转入饱和漂白粉溶…     

莱茵衣藻突变体与野生型RUBISCO酶动力学参数的比较研究

以莱茵衣藻的Ｒｕｂｉｓｃｏ突变体６９－１２Ｑ＾＋,６８－４ＰＰ＾＋和野生型２１３７＾＋为材料,分析比较了Ｒｕｂｉｓｃｏ粗酶在不同温度,不同ｐＨ条件下的初始活性,２５℃时的总活性,酶的最适温度,最适ｐＨ和粗酶的活化百分数,用Ｋｏｓｔｏｖ和ＭｃＦａｄｄｅｎ的作图法测定了３个品系Ｒｕｂｉｓｃｏ纯化酶在２５℃时的ＣＯ２／Ｏ２特征因子Ω值结果６９－１２Ｑ＾＋的Ω＝１３;６８－４ＰＰ＾＋的为５４;２１３７＾＋     

神经节苷脂（Gangliosides）对人红细胞膜Ca^2＋—Mg^2＋ATPase的影响

神经节苷脂（Ｇａｎｇｌｉｏｓｉｄｅｓ）是红细胞膜Ｃａ＾２＋－Ｍｇ２＋ＡＴＰａｓｅ的一种激活剂,这种激活作用也是依赖于Ｃａ＾２＋存在。在２００μｍｏｌ／Ｌ Ｃａ＾２＋存在的反应体系中,１００μｇ／ｍＬ Ｇａｎｇｌｉｏｓｉｄｅｓ对Ｃａ＾２＋－Ｍｇ＾２＋ＡＴＰａｓｅ的激活作用最大,为基本酶活性的１５０％以上。实验还发现ＣａＭ拮抗剂三氟嗪（ＴＥＰ）、粉防已碱（Ｔｅｔ）等也同样抑制Ｇａｎｇｌｉｏｓｉｄｅｓ的     

镁,钙子对组装于人工膜上CF0—CF1质子传导的影响

在电压箝位下,研究Ｍｇ＾２＋、Ｃａ＾２＋对重组于平板脂双层上ＣＦ０－ＣＦ１质子传导的影响,表明：（１）跨膜质子梯度０时（ΔｐＨ＝０）,在３０￣１５０ｍＶ范围内有大量的金Ｃａ＾２＋引起的正电流比在无金属离子溶液中的一定幅度的增加。在５０ｍＶ以上,Ｍｇ＾２＋比Ｃａ＾２＋有更大的促进正向电流的作用;（２）当ΔｐＨ＝３时,Ｍｇ＾２＋比Ｃａ＾２＋更有显著增加正向膜电流的作用,电压在０ｍＶ时就已显示出来;（３     

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.