花生幼苗下胚轴质膜Ca2+-ATP酶及其对低温胁迫的反应

经６％－１２％ＤｅｘｔｒａｎＴ７０密度梯度离心,获得了纯度较高的７ｄ龄花生幼苗下胚轴质膜制剂,质膜Ｃａ＾２＋－ＡＴＰａｓｅ在反应系统不存在Ｍｇ＾２＋时,可正常表现水解ＡＴＰ的活性,但此活性明显低于Ｍｇ＾２＋激活的ＡＴＰａｓｅ,Ｃａ＾２＋－ＡＴＰａｓｅ不受Ｎａ３ＶＯ４抑制,不被Ｋ＾＋激活,而被Ｃｌ＾－抑制,Ｃａ＾２＋－ＡＴＰａｓｅ的最适,ｐＨ不同于Ｍｇ＾２＋激活的ＡＴＰａｓｅ,低温胁迫显著提高质膜Ｃ     

光周期对光敏胞质不育小麦花药发育过程中Ca^2＋分布的影响

运用焦锑酸钾沉淀法,研究了不同光照条件下光敏胞质不育小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）花药发育过程中Ｃａ＾２＋的分布。短日照条件下,小孢子形成和花粉发育过程中胞内Ｃａ＾２＋在数量、分布上有变化;小孢子表面逐渐积累Ｃａ＾２＋,至成熟花粉表面覆盖一层Ｃａ＾２＋,胞质Ｃａ＾２＋较少;药隔和药壁组织通过抽外体或共质体途径运输Ｃａ＾２＋供给花粉的发育;长日照条件下,花粉败育发生在不同时期,早期     

抗寒锻炼对冬小麦幼苗质膜Ca^2＋—ATPase的稳定作用

通过氯化铈（ＣｅＣｌ３）沉淀的电镜细胞化学方法,观察了抗寒锻炼对冬小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）幼苗质膜Ｃａ２＋ＡＴＰａｓｅ的稳定作用,主要结果是：（１）正常温度（２０℃）下生长的冬小麦幼苗（未经抗寒锻炼）,其质膜上有很强的Ｃａ２＋ＡＴＰａｓｅ活性反应;当经过－９℃３ｈ的低温处理后,质膜的Ｃａ２＋ＡＴＰａｓｅ活性明显降低;在处理１２ｈ后,质膜的Ｃａ２＋ＡＴＰａｓｅ活性进一步降低;当处理时间延长到２４ｈ,质膜的Ｃａ２＋ＡＴＰａｓｅ完全失活,同时细胞的超微结构受到破坏。（２）冬小麦幼苗在２℃低温下锻炼１５ｄ后,其质膜的Ｃａ２＋ＡＴＰａｓｅ活性高于未经抗寒锻炼的小麦幼苗。抗寒锻炼后的小麦幼苗在－９℃处理３ｈ后,质膜的Ｃａ２＋ＡＴＰａｓｅ活性与低温处理前相比无明显降低;经低温处理１２ｈ,质膜仍保持较高的Ｃａ２＋ＡＴＰａｓｅ活性,较同样低温处理（－９℃,１２ｈ）但未经抗寒锻炼的幼苗高;当－９℃低温处理２４ｈ后,质膜上仍可观察到Ｃａ２＋ＡＴＰａｓｅ的活性反应,而且细胞的超微结构也未受到破坏。结果表明,抗寒锻炼可提高冬小麦幼苗质膜Ｃａ２＋ＡＴＰａｓｅ在低温下的稳定性     

低氧、血管紧张素Ⅱ对肺内小动脉平滑肌细胞膜Ca2 ┐ATPase活力的影响

本课题观察了低氧及血管紧张素Ⅱ（ａｎｇｉｏｔｅｎｓｉｎⅡ,ＡｎｇⅡ）对分离培养家兔肺内小动脉平滑肌细胞（ＰＡＳＭ－Ｃｓ）膜Ｃａ２＋－ＡＴＰａｓｅ活力的影响,同时用钙通道阻断剂维拉帕米（ｖｅｒａｐａｍｉｌ,ＶＰ）进行干预,进一步了解细胞内钙与Ｃａ２＋－ＡＴＰａｓｅ活力的关系。结果表明：ＰＡＳＭＣｓ膜Ｃａ２＋－ＡＴＰａｓｅ活力对低氧具有短暂的耐受性,随低氧时间延长,Ｃａ２＋－ＡＴＰａｓｅ活力呈时间依赖性抑制;低氧、ＡＮＧⅡ均能抑制Ｃａ２＋－ＡＴＰａｓｅ活力（Ｐ＜０．０１）低氧＋ＡⅡ对Ｃａ２＋－ＡＴＰａｓｅ活力的抑制具叠加效应（Ｐ＜０．０５）;ＶＰ可逆转低氧、ＡｎｇⅡ、低氧＋ＡｎｇⅡ对Ｃａ２＋－ＡＴＰａｓｅ活力的抑制（Ｐ＜０．０１）。结果提示：低氧,ＡＮＧⅡ可通过抑制肺血管平滑肌细胞膜Ｃａ２＋－ＡＴＰａｓｅ活力而可能削弱肺血管平滑肌舒张功能也可能是低氧性肺动脉高压（ＨＰＨ）形成的原因之一。     

低温逆境中不同抗寒性植物细胞内Ca^2＋稳定平衡的区别

电镜细胞化学观察揭示,不抗寒的玉米（Ｚｅａ ｍａｙｓ Ｌ．ｅｖ． Ｂｌａｃｋ Ｍｅｘｉｃａｎ Ｓｗｅｅｌ）和抗寒的小偃麦（Ｔｒｉｔｉｃｕｒｎ ｓｅｅｔ．Ｔｒｉｔｉｔｒｉｇｉａ ｍａｃｋｅｙ）细胞在２６℃悬浮培养时,标志Ｃａ＾２＋定位的锑酸钙沉淀物主要分布在液泡内,细胞质和细胞核中很少见到Ｃａ＾２＋沉淀;标志Ｃａ＾２＋－ＡＴＰａｓｅ活性的反应的磷权沉淀物丰富地分布在质膜上,显示这两种植物物质膜Ｃａ＾     

稀土离子对CaM及Ca2+-Mg2+-ATPase活力及CD研究

研究了稀土离子（Ｌｎ３＋）对钙调蛋白（ＣａＭ）调控的Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ的活力影响。结果表明,在ＣａＭ和Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ的体系中,一些Ｌｎ３＋（Ｌａ３＋、Ｇｄ３＋）对由ＣａＭ调节的Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ的活力影响呈现双相效应,即Ｌｎ３＋在低浓度时,能提高激活Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ的水解活力;在高浓度时,则抑制ＣａＭ调节Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ活力的能力;少数Ｌｎ３＋（Ｓｍ３＋）仅表现出抑制效应。在无ＣａＭ的Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ体系中,高浓度的Ｌｎ３＋抑制Ｃａ２＋－Ｍｇ２＋－ＡＴＰａｓｅ的基础活力。结合圆二色（ＣＤ）谱信息对Ｌｎ３＋和ＣａＭ相互作用的分子机制进行了初步的探讨。     

氧化脂质及对大鼠心肌肌质网Ca^2＋—ATPase磷酸化微…

用ＴＡＢ法测定了三尖杉酯碱的膜脂氧化效应;用纳秒荧光偏振技术研究了氧化膜脂对ＤＰＨ标记大鼠心肌肌质网膜脂、ＡＮＭ标记心肌肌质网Ｃａ＾２＋－ＡＴＰａ功能及磷酸化微区运动状态的影响。随膜脂中氧化磷脂的增加,肌质网膜脂双层的微粘度增加,磷脂分子摆动角减小;ＤＰＨ的荧光强度减弱,荧光寿命缩短。Ｃａ＾２＋－ＡＴＰａｓｅ的ＡＴＰ水解活性降低。ＡＮＭ标记Ｃａ＾２＋－ＡＴＰａｓｅ磷酸化微区的ｒ（ｔ）曲线半衰期减至     

小麦根液泡膜上存在两种类型ATPase

采用Ｓｅｐｈａｒｏｓｅ ４Ｂ柱层析的方法在小麦根液泡膜中分离出两种ＡＴＰａｓｅ,一种需Ｍｇ＾２＋存在于表现催化活性,受质子通道抑制剂ＤＣＣＤ（二环已基碳二亚胺）的抑制和Ｃｌ＾－的激活,为需Ｍｇ＾２＋ＡＴＰａｓｅ,另一种不需Ｍｇ＾２＋就可表现出催化活性,受Ｃａ＾２＋的强烈激活,不受ＤＣＣＤ的抑制和Ｃｌ＾－激活,可能前者与转运质子有关,后者与Ｃａ＾２＋的转运有关。     

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。     

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     

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.