SOD对骨髓造血祖细胞在4°C条件下保存损伤的防护作用

为了探讨抗氧化剂对造血干细胞在低温条件下损伤的防护作用,将小鼠骨髓细胞置于４℃条件下保存,观察在保养液中加入不同浓度的Ｃｕ、Ｚｎ、ＳＯＤ对细胞死伤的防护效果和马血清对细胞回收率的影响。结果表明,含２０％的马血清保养液中加入ＳＯＤ１．６５Ｕ或０．１６５Ｕ／ｍｌ,保存３天,ＣＦＵ－ＧＭ、ＣＦＵ－Ｅ、ＢＦＵ－Ｅ、ＣＦＵ－Ｍｅｇ、ＣＦＵ－Ｍｉｘ的产率分别为对照组（不加ＳＯＤ）的６．２、２．６、２．９、４．０和５．１倍,明显提高了造血祖细胞的活存率,其中ＣＦＵ－ＧＭ和ＣＦＵ－Ｍｉｘ达到保存前水平。ＳＯＤ的有效作用机理不是对造血祖细胞增殖调控作用,而是防护了细胞的死亡。这可能与其清除过氧自由基的抗氧化作用有密切关系。     

SOD对骨髓造血祖细胞在4℃条件下保存损伤的防护作用

为了探讨抗氧化剂对造血干细胞在低温条件下损伤的防护作用,将小鼠骨髓细胞置于４℃条件下保存,观察在保养液中加入不同浓度的Ｃｕ、Ｚｎ、ＳＯＤ对细胞死务的防护效果和马血清对细胞回收率的影响。结果表明,含２０％的马血清保养液中加入ＳＯＤ１．６５Ｕ或０．１６５Ｕ／ｍｌ,保存３天,ＣＦＵ－ＧＭ、ＣＦＵ－Ｅ、ＣＦＵ－Ｍｅｇ、ＣＦＵ－Ｍｉｘ的产率分别为对照组的６．２、２．６、２．９、４．０和５．１倍。明显提高了造     

用NSF─60细胞MTT比色法检测重组人粒系集落刺激因子的生物活性

利用Ｇ－ＣＳＦ依赖型细胞株Ｎ８Ｆ－６０,尝试将ＭＴＴ比色法应用于基因工程产品重组人粒系集落刺激因子（ｒｈＧ－ＣＳＦ）的活性检测。多次实验探索出最适的细胞浓度和培养时间,细胞数为低于１×１０￣４／孔,培养时间为３０─４８ｈ。在宽的线性范围内检测Ｇ－ＣＳＦ样品的生物活性,结果经传统的ＣＦＵ－Ｇ方法验证可靠,且较后者更灵敏、简便、省时、省力,并可定性、定量地检测样品活性。特别适用于大量样品的同时检测。另外,此方法可避免接触放射性。     

类卟啉稀土配合物对于小鼠腹水肝癌细胞光敏损伤的研究

研究了类卟啉稀土配合物（以下简称ＰＬＭ－Ｇｄ－Ａ）对小鼠腹水肝癌细胞（ＡＨ）的光敏作用及ＡＨ细胞对ＰＬＭ－Ｇｄ－Ａ的摄取表明：ＰＬＭ－Ｇｄ－Ａ被ＡＨ细胞摄取的速度快,用ＭＴＴ方法测定了细胞光敏存活曲线,杀伤细胞的能力与光照时间和光照强度以及ＰＬＭ－Ｇｄ的浓度密切相关,用ＦＡＤＵ方法和电镜观察结果证明：该光敏损伤细胞的靶主要是在细胞核;对于不同稀土离子配合物光敏能力比较表明：Ｇｄ＞Ｅｕ＞Ｓｍ;造成细     

甲基单胞菌Methylomonas sp.GYJ3中甲烷单加氧酶还原酶组分的纯化和性质

Ｍｅｔｙｌｏｍｏｎａｓｓｐ．ＧＹＪ３菌的甲烷单加氧酶（ＭＭＯ）粗酶提取液经ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析、ＳｅｐｈａｄｅｘＧ－１００凝胶过滤层析和ＤＥＡＥ－ＴＳＫｇｅｌＨＰＬＣ分离纯化出ＭＭＯ还原酶组分．经ＨＰＬＣ分析,纯度大于９５％,纯化倍数为４．４,加入至ＭＭＯ羟基化酶和调节蛋白Ｂ的体系中表现比活为２２８ｎｍｏｌ环氧丙烷每分钟毫克蛋白．ＳＤＳ－ＰＡＧＥ电泳表明还原酶由一种亚基组成,分子量４２ｋＤ．ＩＣＰ－ＡＥＳ测定还原酶的Ｆｅ含量为１．８３ｍｏｌＦｅ每ｍｏｌ蛋白．ＵＶ－Ｖｉｓ光谱表明还原酶除２８０ｎｍ蛋白质特征峰外在４６０ｎｍ有最大吸收峰,且Ａ２８０ｎｍ／Ａ４６０ｎｍ为２．５０,与其它黄素一铁硫蛋白相似,推测还原酶可能含一个ＦＡＤ辅基和Ｆｅ２Ｓ２中心．在厌氧条件下,还原酶能够和ＮＡＤＨ作用,ＵＶ－Ｖｉｓ光谱分析表明还原酶４６０ｎｍ处特征吸收峰消失,说明在ＭＭＯ催化过程中还原酶接受ＮＡＤＨ的电子．ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析分离出调节蛋白Ｂ,部分纯化的调节蛋白Ｂ的分子量大约在２０ｋＤ,它能够提高ＭＭＯ比活性４０倍,ＭＭＯ还原酶和调节蛋白Ｂ单独存在时不具有ＭＭＯ     

高密度发酵生产突变型重组人肿瘤坏死因子rhTNFα-DK2的研究

通过对发酵基质和发酵关键参数的优化,确定了发酵培养基的磷酸盐浓度为０．１５Ｍ,甘油浓度为１．２ｍｌ／Ｌ,补料中甘油浓度为２０ｍｌ／Ｌ,发酵过程中溶解氧控制在３０％～６０％,ｐＨ控制在６．８５左右。在５Ｌ在ＮＢＳ－Ｂｉｏｆｌｏ３０００型自动控制发酵罐中采取加速补料的补料分批培养,重组大肠杆菌ＹＫ５３７／ｐＳＢ－ＴＫ经１０ｈ３０°Ｃ培养和５ｈ４２°Ｃ诱导培养,最终密度达到６０ＯＤ６００,ｒｈＴＮＦα－ＤＫ２的表达量占菌体总蛋白的５０％以上,每升发酵液纯化可得到近２ｇ的ｒｈＴＮＦα－ＤＫ２。     

与光系统Ⅱ颗粒结合的对DTT敏感的蛋白酶的纯化和性质

菠菜光系统Ⅱ颗粒的１ｍｏｌ／ＬＮａＣｌ抽提液经ｂｕｔｙｌ－Ｔｏｙｏｐｅａｒｌ６５０Ｍ疏水层析和ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－５０柱层析分离得一种对ＤＴＴ敏感的蛋白酶。用ＳＤＳ－ＰＡＧＥ和Ｓｕｐｅｒｏｓｅ１２凝胶过滤测得该酶的分子量为３７ｋＤ,其为单体酶。该酶可降解１８ｋＤ和２４ｋＤ水溶性蛋白质,分别产生１３．２ｋＤ、１２ｋＤ、１０．５ｋＤ和２３ｋＤ、２２ｋＤ、２０ｋＤ片段,最适ｐＨ为８．０,对ＮａＣｌ不敏感,对ＤＴＴ和β－Ｍｅ敏感。抑制实验表明该酶不属丝氨酸类蛋白酶。     

重组人粒细胞-巨噬细胞集落刺激因子包涵体提取、复性和纯化的研究

由基因工程大肠杆菌表达的重组人粒细胞－巨噬细胞集落刺激因子（ｒｈＧＭ－ＣＳＦ）以包涵体的形式存在于细胞中,通过破菌、洗涤获得包涵体,再经过溶解、凝胶过滤、复性、疏水和离子交换柱导析得到了均一的产品,经高压液相和ＳＤＳ－ＰＡＧＥ电泳测定纯度均大于９８％,ｒｈＧＭ－ＣＳＦ的比活为３．２×１０＾７ＩＵ／ｍｇ,纯化获得的ｒｈＧＭ－ＣＳＦ为一酸性蛋白,等电点约为５．２,ＮＨ２－末端有２０个氨基酸序列测定结果     

白细胞介素—2—绿脓杆菌外毒素融合蛋白的分高纯化及其复性研究

表达的白细胞介素－２－绿脓杆菌外毒素（ＩＬ－２－ＰＥ）融合蛋白以包含体形式存在于宿主菌中,为分离纯化表达产物提供了方便,但因需进行复性,也增加了后处理的难度．我们采用４ｍｏｌ／Ｌ尿素、０．５％ＴｒｉｔｏｎＸ－１００的１×ＰＢＳ洗涤包含体两遍,再经ＳｅｐｈａｃｒｙｌＳ－３００分子筛及ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＦＦ阴离子交换柱层析后,获得的融合蛋白纯度可达９０％～９５％。此外,我们从ＧＳＳＧ浓度、Ｌ－精氨酸浓度、复性蛋白质的起始浓度、复性液的ｐＨ值、复性温度及复性时间等参数入手,系统地研究了融合蛋白的复性条件,探索到了ＩＬ－２－ＭＥ４０和ＩＬ－２－ＰＥ６６４Ｇｌｕ融合蛋白复性的最适条件。     

细菌转化黑色素的抗流感病毒作用

采用敏感的ＭＴＴ法测定了嗜麦芽假单胞菌转化黑色素的抗流感病毒作用。测定结果表明：纯化的黑色素毒性极低,对ＭＤＣＫ细胞的无毒界限为０．２ｍｇ／ｍｌ,远高于其有效的作用浓度;１０～２０μｇ／ｍｌ的黑色素能有效抑制流感病毒（血凝效价１∶３２）致细胞病变。病毒感染７２ｈ后用ＭＴＴ法测定,其宿主ＭＤＣＫ细胞保护百分率达９５％以上;此外,加黑色素后的ＭＤＣＫ细胞,抗流感病毒感染的能力优于目前抗病毒的有效药物病毒唑,前者的最佳作用浓度（２０μｇ／ｍｌ）比后者（１００μｇ／ｍｌ）低５倍。可以认为嗜麦芽假单胞菌转化黑色素具有毒性低、抗流感病毒能力强的特点     

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.