哺乳类(兔)红细胞分化因子的纯化及特性分析

本文报道从哺乳动物(兔)红细胞分离、提纯红细胞分化因子(ErythroidDifferentiation Factor,简称EDF及对其性质的分析。按Bishop方法给新西兰兔注射盐酸苯肼(2.5％)0.3mL/kg体重/日连续6days致贫血,收集血液用生理盐水洗去白细胞后,得到的网织红细胞用冻融法使细胞裂解,用乙醇、氯仿选择性变性除去血红蛋白,凝胶过滤,连续经DEAE-纤维素及CM-纤维素柱层析,取得较原裂解液纯化了31 000倍的活性物质EDF,产率为9.1％,分子量15kD,在SDS-PAGE电泳图中为单一蛋白带。EDF对热相对稳定,100℃处理10min仍保持一定活性,对蛋白酶敏咸而对DNA酶I及RNA酶不敏感。EDF对体外培养细胞的生长抑制作用已在体外实验体系得到验证。     

玉米、小麦、水稻原生质体制备条件优化

玉米Zea mays L.、小麦Triticum aestivum L.、水稻Oryza sativaL.是三大重要粮食作物,对其原生质体制备条件的优化具有重要意义.以玉米(综3)、小麦(中国春)、水稻(日本晴)10日龄幼苗为材料,研究了叶肉细胞原生质体分离过程中的酶浓度、酶解时间和离心力大小等因素对产量和活力的影响.结果表明:酶浓度和酶解时间对原生质体产量影响显著,随着酶解液浓度和酶解时间的提高,原生质体产量增加,但细胞碎片同时增多.水稻经真空处理后,原生质体产量大幅度提高.通过正交实验设计得出如下结果:玉米叶肉细胞原生质体分离的最佳条件为:纤维素酶1.5％,离析酶0.5％,50 r/min酶解7h,100×g离心2 min收集,原生质体产量为7×106/g FW;小麦叶肉细胞原生质体分离的最佳条件为:纤维素酶1.5％,离析酶0.5％,50 r/min酶解5h,100×g离心2 min收集,原生质体产量为6×106/g FW;水稻叶肉细胞原生质体分离的最佳条件为:纤维素酶2.0％,离析酶0.7％,50 r/min酶解7h,1 000×g离心2 min收集,得到的原生质体产量为6×106/g FW.通过二乙酸荧光素染色发现原生质体活力均在90％以上.用PEG-Ca2+介导法将含有绿色荧光蛋白的质粒转化入原生质体,转化率可达50％ ～80％.     

培养液中纤维素酶的分离纯化

目的:为了研究纤维素酶的特性,使之利用纤维素从而促进纤维素资源化,减少环境污染,该文选用作者实验室筛选出的菌株K7-2培养产生纤维素酶,进行了纤维素酶的分离纯化。方法:将菌株K7-2在30℃、150r/min摇床培养3d,于5 000r/min离心30min,取上清液即为粗酶液,经硫酸铵分级沉淀、Sephadex G-75凝胶过滤层析、DEAE-Sephadex A-25离子交换层析方法进行分离纯化。结果:分离纯化后的酶活是0.0904U/ml,比活力提高4.1120倍。结论:这为进一步研究此纤维素酶的组份、结构和理化特性奠定了基础。     

黄鳝的繁殖生态学研究

以洞庭湖稻区黄鳝为调查研究对象 ,通过野外调查和室内实验系统研究了黄鳝的繁殖生态。对黄鳝的性腺发育周年变化、繁殖行为、自然产卵过程、产卵条件及繁殖洞穴的构造进行了观察和记录 ,产卵室是黄鳝繁殖洞穴特有的构造 ,繁殖洞穴泥土p H平均值为 6 .73± 1.0 12。亲鳝有护卵习性 ,通过对 30尾守洞亲鳝的性腺观察和切片验证 ,守洞鳝多为雄鳝 (占 6 1.3% ) ,少数为兼性偏雄性 (占 38.7% ) ,守洞鳝 1:0 0～ 2 :0 0全在外面活动 ,守洞鳝体长 L (cm)与体重 W (g)回归方程为 :W=1.2 5×10 - 2 L1 .4 2 (r=0 .76 )。人工模拟条件下 ,泡沫组受精卵的平均孵化率 (85 .2 % )极显著地高于对照组 (2 5 .4 % ) (t=8.18,t0 .0 5=2 .4 5 ) ,仔鱼平均成活率 (6 4 .0 % )显著高于对照组 (14 .0 % ) (t=3.73) ,同时对繁殖季节黄鳝为孵卵而所吐的泡沫的作用进行了分析。另外 ,证实了黄鳝产卵的最适放养密度为 2～ 3尾 / m2。为黄鳝的全人工繁殖和半人工繁殖提供了合理化的建议     

出芽短梗霉膨大细胞分选及产糖分析

本研究运用Percoll密度梯度离心的方法对出芽短梗霉Aureobasidium pullulans的两种细胞形态进行分选,并对两种形态的细胞进行多糖产量的分析。通过对转速、分选时间、Percoll分离液浓度的优化,确定了两种细胞形态分选效果最佳的条件是Percoll分离液浓度为60%、转速为5 000r/min、离心时间为30min。经过光学显微镜和透射电子显微镜观察发现上层为酵母状细胞（YL）、下层为膨大细胞（SC）,并发现膨大细胞外有明显的薄膜包被,且产大量多糖。也为今后在相应状态下研究出芽短梗霉膨大细胞的其他代谢机理提供了可行的方法,满足后续研究的需要。     

鹿茸硫酸软骨素蛋白聚糖的分离纯化研究

报道了用DEAE-纤维素(DE-23)离子交换柱层析从鹿茸二杠中分离、纯化及鉴定硫酸软骨素的方法.首先用适量蒸馏水浸泡鹿茸二杠并将其捣碎,离心取沉淀用盐酸胍浸提,浸提液对尿素液透析后经DEAE-纤维素(DE-23)离子交换柱层析,吸附大量的硫酸软骨素;再用含盐尿素溶液梯度洗脱、分离后,经软骨素酶消化及琼脂糖凝胶电泳, 与硫酸软骨素标准品比较,证实得到的物质为纯的硫酸软骨素蛋白聚糖,其得率约为48.77%.该方法使硫酸软骨素分离纯化一步完成,大大简化了纯化步骤.     

离心法分离毕赤酵母活细胞和死细胞

本文以毕赤酵母为研究对象,探索出一种分离活酵母细胞的新方法。研究发现,通过改变淋巴细胞分离液和50%聚蔗糖溶液的比例,获得不同密度的酵母细胞分离液,进而通过离心分层的方法可使毕赤酵母活细胞主要存留于离心液的上层。当酵母细胞分离液的密度为1.1467 g/mL (27.5%淋巴细胞分离液+72.5%聚蔗糖溶液),分离液上下层中酵母活细胞的分配比例差别达到最大,分别为94.67%(分离液上层)和5.33%(分离液下层)。毕赤酵母细胞浓度为4.35×108~1.13×109/mL时,活细胞在分离液上下两层的分配比例约为95%和5%。低毕赤酵母细胞存活率有利于离心分离。本方法可用于有效分离培养液中的毕赤酵母活细胞。     

一种简易高效的小麦叶片胞间液蛋白提取方法的建立

植物细胞间液中的蛋白在植物生长发育和抗病抗逆反应及其信号传导过程中发挥着重要作用,是植物学研究的新热点.由于细胞间液含量低,容易因组织细胞损伤性受到胞内成分污染,高纯度的细胞间液蛋白的提取相对困难,参考相关文献报道,建立了一种简易高效的小麦叶片细胞间液蛋白的提取方法.选取小麦品种“铭贤169”幼苗叶片为材料,用50mmol/L NaAc缓冲液充分浸润,负压处理20 min后,30 × g离心5 min除去叶片表面缓冲液,随后2 000×g离心15 min,收集小麦叶片胞间液.将获得的小麦叶片胞间液冷冻干燥后,进行SDS-PAGE分离分析.电泳胶图上显示出细胞间液提取物与叶片组织提取物的蛋白质组成有极显著差异,使用MALD-TOF/TOF MS技术分析SDS胶上的细胞间液蛋白条带,共鉴定到9种非高丰度或假定的蛋白,其中有两种是已报道过的植物细胞间液蛋白.试验结果表明,本方法简易高效,适用于小麦蛋白质组学研究中高纯度的细胞间液蛋白的提取.     

黄鳝减数分裂雌核发育及子代遗传纯合度分析

为了培育性状优良、遗传稳定的黄鳝(Monopterus albus)群体,研究探索了人工诱导黄鳝减数分裂雌核发育方法。针对养殖性状优良的深黄大斑鳝进行种质纯合,创制出3个深黄大斑鳝雌核发育群体。流式细胞术和染色体计数分析表明雌核发育黄鳝的细胞DNA含量、染色体数目均与野生型相同。性腺组织学切片观察表明雌核发育黄鳝卵巢发育正常。微卫星多样性分析表明雌核发育黄鳝群体的有效等位基因(N_e)、平均香农指数(I)、平均多态信息指数(PIC)、平均观测杂合度(H_o)及平均期望杂合度(H_e)等参数均极显著低于野生群体,雌核发育群体的遗传纯合度显著提高。雌核发育群体之间的遗传距离增大,遗传相似系数变小。深黄大斑鳝雌核发育群体为培育性状优良的黄鳝养殖品种提供了育种材料。     

透析式洗涤冰冻红细胞去除白细胞和血小板的方法

目的：用低速离心的方法减少悬浮红细胞中自细胞和血小板的数量,使透析式洗涤机洗涤的冰冻红细胞中白细胞和血小板的残留量小于1％。方法：分别选用低速离心（700和500r／min）和常规离心（3800r／min）全血制备悬浮红细胞,计算白细胞和血小板的清除率;甘油低温冰冻保存,透析式冰冻红细胞洗涤机洗涤冰冻红细胞,对洗涤后的红细胞进行质量检测。结果：500r／min离心后白细胞和血小板的清除率（％）分别为53.82±6.83和85.23±4.21;洗涤后的冰冻红细胞中白细胞和血小板残留量（％）分别为0.843±0.058和0.903±0.035。700r／min离心后白细胞和血小板的清除率（％）分别为23.38±2.36和62.61±3.82;洗涤后的冰冻红细胞中白细胞和血小板残留量（％）分别为0.983±0.024和1.021±0.045。3800r／min离心后白细胞和血小板的清除率（％）分别为9.82±4.12和6.39±3.26;洗涤后的冰冻红细胞中白细胞和血小板残留量（％）分别为3.839±2.896和3.528±2.689。结论：用500r／min离心全血制备的悬浮红细胞,经甘油低温冻存,透析式洗涤机洗涤后,血小板和白细胞的残留量等各项指标均符合国家标准。     

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.