短裙竹荪(Dityophora duplicata)凝集素纯化与生化性质

短裙竹荪子实体经生理盐水抽提、硫酸铵沉淀、DEAE Sepharose和SephadexG 10 0柱层析纯化得到短裙竹荪凝集素 (Dityophoraduplicata(Bosc)Fischerlectin) ,简称DDFL .DDFL经PAGE显示单一条带 ,SDS PAGE测得其亚基分子量为 2 2 3kD ,SephadexG 10 0凝胶过滤测得分子量为 4 5 3kD ,DDFL不含中性糖 ,IEF测得其等电点为 3 92 .该凝集素对供试的 4种血型人血和兔、小牛、鸭、鸡、鲫鱼以及青蛙血红细胞具有凝集作用 ,但不凝集鳖红细胞 .它还可以凝集小鼠脾脏淋巴细胞和小鼠S180 肉瘤细胞 ,对兔红细胞的凝集作用可被乳糖、棉子糖、半乳糖、α 甲基半乳糖、β 甲基半乳糖和N 乙酰半乳糖胺所抑制 .氨基酸组成分析表明 ,DDFL含有 17种氨基酸 ,其中天冬氨酸、丝氨酸、苯丙氨酸和丙氨酸含量较高 .经测定 ,其N末端为甘氨酸 .DDFL对热、酸和碱具有一定的稳定性 ,经 6 0℃处理 10min ,可保持较高的活性 ,在pH 4 0～ 9 0范围内较稳定 ,其凝血活性依赖于Mg2 + 和Ca2 + 二价阳离子 ,Mn2 + 和Zn2 + 则无影响 .DDFL对小鼠腹腔注射的半致死量为 70 6 3mg kg .     

斑玉蕈Hypsizygus marmoreus凝集素的部分性质和细胞凝集活性分析

斑玉蕈子实体经生理盐水抽提、30%~60%饱和度的硫酸铵沉淀、DEAE-Cellulose和SephadexG-100柱层析纯化得到斑玉蕈凝集素(HypsizygusmarmoreusLectin,简称HML)。HML经PAGE显示单一条带,SDS-PAGE测得亚基相对分子质量为34.2kD,SephadexG-100凝胶过滤测得相对分子质量为35kD,中性糖含量为7.2%,含有17种氨基酸,IEF-PAGE测得其等电点为8.15。该凝集素能凝集多种动物红细胞和人的A、B、AB和O血型红细胞,对兔红细胞的凝集作用可被甘露糖、半乳糖、N-乙酰半乳糖胺和岩藻糖所抑制。HML对热较敏感,经50℃处理10min,凝集活性下降明显,但对酸碱具有一定的稳定性,在pH5.0~8.0范围内较稳定。Β-消去反应测得其糖和蛋白质的连接键为O-型糖肽键。     

斑玉蕈Hypsizygus marmoreus凝集素的部分性质和细胞凝集活性分析

斑玉蕈子实体经生理盐水抽提、30%~60%饱和度的硫酸铵沉淀、DEAE-Cellulose和SephadexG-100柱层析纯化得到斑玉蕈凝集素(HypsizygusmarmoreusLectin,简称HML)。HML经PAGE显示单一条带,SDS-PAGE测得亚基相对分子质量为34.2kD,SephadexG-100凝胶过滤测得相对分子质量为35kD,中性糖含量为7.2%,含有17种氨基酸,IEF-PAGE测得其等电点为8.15。该凝集素能凝集多种动物红细胞和人的A、B、AB和O血型红细胞,对兔红细胞的凝集作用可被甘露糖、半乳糖、N-乙酰半乳糖胺和岩藻糖所抑制。HML对热较敏感,经50℃处理10min,凝集活性下降明显,但对酸碱具有一定的稳定性,在pH5.0~8.0范围内较稳定。β-消去反应测得其糖和蛋白质的连接键为O-型糖肽键。     

狗脊蕨凝集素的分离纯化与部分性质

狗脊蕨叶组织经磷酸缓冲液抽提,硫酸铵分级沉淀,DEAE-Sepharose(fast flow)离子交换层析和Sephadex G-100分子筛层析,获得具有凝集活性的狗脊蕨凝集素.用PAGE和SDS-PAGE检测均显示1条蛋白带,提示狗脊蕨凝集素分子只有一个亚基.Sephadex G-100层析和SDS-PAGE测得其相对分子质量在20 kD左右.该凝集素对红细胞有种属专一性,其凝集活性可被木糖、卵粘蛋白所抑制.狗脊蕨凝集素对热相当稳定,以100℃温度加热10 min仍保存部分凝集活性.凝集活性不依赖于金属离子Mg2 、Ca2 、Mn2 .它的中性糖含量为3.1%,Phe含量较高,His含量较低,不含Tyr和Pro.     

甘薯凝集素的提取及性质研究

抗蔓割病甘薯的叶片组织浸取液,经硫酸铵分级沉淀,甲壳素柱层析及葡聚糖凝胶过滤得到一种在PAGE或SDS－PAGE上均呈现单一蛋白带的甘薯凝集素。该凝集素没有血型专一性及被测动物红细胞专一性,其凝集活性可被N－乙酰葡萄糖胺或岩藻糖所抑制。甘薯凝集素在75℃加热10min,即丧失全部凝集活性,其凝集活性依赖于Ca^2 和Mg^2 ,Mn^2 则无作用。经Sephadex G-100和SDS－PAGE测定,凝集素相对分子质量为63000,中性糖含量为6.21%,该凝集素对蔓割病菌有抑制作用,是一种酸性糖蛋白。     

牛舌菌凝集素的分离、性质及细胞凝集活性

牛舌菌子实体经生理盐水抽提、硫酸铵沉淀、DEAE-Cellulose和Sephadex G-100柱层析纯化得到牛舌菌凝集素(Fistulina hepatica Lectin,FHL)。FHL经PAGE显示单一条带,SDSPAGE测得其亚基相对分子质量为63．6KD,Sephadex G-100凝胶过滤测得相对分子质量为63KD,FHL中性糖含量为9．7％,IEF-PAGE测得其等电点为5．36。该凝集素对人的A、B、AB和O型血细胞具有凝集作用,对兔红细胞的凝集作用可被乳糖和N-乙酰半乳糖胺所抑制。氨基酸组成分析表明,FHL含有16种氨基酸,其中天冬氨酸和谷氨酸含量较高。FHL对热、酸具有一定的稳定性,经60℃处理10min,仍有较高的活性,在pH3．0～6．0范围内较稳定,但在碱性pH环境中(pH7．0～10．8),FHL的凝集活性下降明显。β-消去反应测得其糖和蛋白质的连接键为O-型糖肽键。抗肿瘤活性测定表明,FHL对HeLa细胞具有明显抑制作用。     

泥蚶(Tegillarca granosa Linnaeus)血淋巴液凝集素的分离纯化及其性质研究

泥蚶是一种重要的海产经济贝类,其血淋巴液经硫酸铵二步分级沉淀后,再经Sephadex G- 100凝胶过滤和Sepharose 4B亲和层析纯化制得泥蚶血淋巴液凝集素。经测定,该凝集素分子量约为123Kda,为两个亚基的蛋白质,其相对分子量分别为15 KDa和16 KDa,分子中含5．02％的糖。在氨基酸组成中,天门冬氨酸(Asp)含量最高,其次是谷氨酸(Glu)和组氨酸(His),不含蛋氨酸(Met)。泥蚶血淋巴液凝集素对多种天然或经酶修饰的人或动物红细胞具有不同的凝集作用,其中对兔红细胞的凝集活性最大。半乳糖和乳糖对其凝集活性具有抑制作用。凝集活性依赖于Ca2 ,在pH7．0较稳定,热稳定性不高,在30℃-70℃时凝集效价由原来的25下降为21,当温度超过80℃以后,凝血活性完全丧失。     

香螺血清、肌肉和唾液腺凝集素凝集性能的初步研究

研究香螺(Naptunea cumingi crosse)肌肉、血清和唾液腺凝集素对7 种脊椎动物红细胞、人的4 种红细胞、4 种单细胞藻类和11 种微生物细胞的凝集性能,同时进行pH敏感性、热稳定性、糖抑制性、EDTA、金属离子以及盐浓度影响试验.结果表明,3 种凝集素对各种细胞的凝集效应存在差异,以家兔红细胞的凝集效果最佳.肌肉和血清凝集素在pH<7.0时均失活,唾液腺凝集素的热稳定性最强,温度为90 ℃仍具有活性.此外,不同的糖溶液对3 种凝集素凝集效果的影响不同,在EDTA浓度为2.00～0.25 mmol/L范围内,3 种凝集素的凝集效价均受到不同程度的抑制.在金属离子影响试验中发现,Zn2+能明显提高肌肉和血清凝集素的凝集活力,而对唾液腺凝集素有抑制的作用.当盐浓度为12～18 g/L时,可增加香螺肌肉凝集素的凝集效价,而当浓度为24～60 g/L时却会抑制肌肉凝集素的凝集活性.     

香灰菌凝集素的纯化及其部分性质

香灰菌菌丝体经磷酸缓冲液抽提、20%-70%饱和浓度的硫酸铵沉淀、DEAE-Cellulose和SephadexG-100柱层析纯化得到香灰菌凝集素(Hypoxylonsp.lectin,简称HSL)。HSL经PAGE检测为单一蛋白条带,SDS-PAGE测得其亚基分子量为15.9kD。过碘酸-Schiff染色法表明HSL为一种糖蛋白,糖基的含量为15.5%,β-消去反应测得其糖和蛋白质的连接键为O-型糖肽键。HSL能凝集多种动物红细胞和人的红细胞,在所测试的红细胞中,对兔红细胞的凝集作用最强。HSL对热较敏感,经50°C处理10min,其凝集活性明显降低,其在碱性环境中较稳定,而在酸性环境中较不稳定。HSL的凝集活性受Al3+、Fe3+、Ca2+和Zn2+等阳离子的影响。对鼠红细胞的凝集作用可被半乳糖和乳糖所抑制。     

从绿藻礁膜（Monostroma nitidum Wittr）分离半乳糖专一的凝集素

礁膜（Monostroma nitidum Wittr）经 25%～80%硫酸铵分级、DEAE-纤维素52离子交换层析和Sephadex G-200凝胶过滤层析,得到纯化礁膜凝集素（Monostroma nitidum lectin,MNL）,在SDS-PAGE上显示单一蛋白染色带. 用Sephadex G-200层析测得其分子质量为66.6 kD, 用SDS-PAGE测得其分子质量为66.2 kD．该凝集素可以凝集人A、B、AB、O型红细胞,且凝集活性相同. 在对人（A、B、AB、O）、兔、鲤、鲫、鼠、羊、鸡、狗的红细胞凝集作用中,兔凝集作用最强．该凝集素在pH 4.00～10.53范围内均有活性,但在pH 5.20～9.40范围内活性最大．经100 ℃热处理30 min后,该凝集素对兔红细胞血凝活性保留25%,活性最大的温度范围为25～55 ℃．MNL被EDTA抑制,最小抑制浓度为3.13 mmol/L,但对 Ca^２＋和Mg^２＋不敏感．该凝集素凝集兔红细胞的作用不被D -果糖、D-甘露糖、D-葡萄糖、蔗糖、麦芽糖、γ-球蛋白、牛甲状腺球蛋白所抑制,但被D- 半乳糖和乳糖抑制,最小抑制浓度分别为5 mmol/L和2.5 mmol/L．     

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.