薯蔓多糖的分离纯化和性质鉴定

以我国资源量巨大的薯蔓为原料, 采用中试设备, 利用水提醇沉法提取多糖。研究了活性炭脱色工艺, 经初步纯化获得薯蔓多糖(PSPV), 并研究了其理化性质。DEAE-纤维素柱对来自于二个季节的PSPV进行分离、纯化, 分别得到PSPVⅠ和PSPVⅡ、PSPVⅢ三个多糖组分, 高效凝胶过滤色谱法测定三个组分的分子量分别为6.278×104 D, 3.801×104 D和1.418×104 D, 气相色谱结合标样测定单糖组成。研究结果为充分高效利用薯蔓资源提供了理论依据。     

丹皮多糖PSM2b的纯化及其理化性质研究

从中药丹皮(MoutanCortex)蒸馏水浸提液得到粗多糖,经DEAE Cellulose 52柱层析分离得到降血糖组分PSM2b,Surperdex200柱层析进一步纯化得到PSM2b A和PSM2b B两个组分,快速层析纯化系统(FPLC)和电泳鉴定为均一的多糖蛋白复合物。FPLC法测定A和B两组分的分子量分别为1.16×105、1.30×104,苯酚 硫酸法测得其总糖含量分别为76.91%、32.00%,Folin 酚法测得其蛋白含量分别为9.90%、42.60%。气相色谱分析PSM2b A的单糖组成为:L 鼠李糖、L 岩藻糖、L 阿拉伯糖、D 木糖、D 甘露糖、D 葡萄糖、D 半乳糖,摩尔比依次为1.00∶0.18∶4.30∶0.50∶1.30∶2.41∶6.97,PSM2b B的单糖组成为:L 鼠李糖、L 岩藻糖、L 阿拉伯糖、D 葡萄糖、D 半乳糖,摩尔比依次为1.00∶1.17∶0.183∶2.34∶4.18。两者的红外光谱呈现多糖吸收特征峰,含有吡喃糖苷键。β消去反应初步证明所提取的两种糖蛋白不存在O 型糖肽键。     

红托竹荪菌托多糖的提取及抗肿瘤活性的初步研究

红托竹荪菌托经热水提取、酒精沉淀、脱蛋白后的粗多糖,其得率远大于其菌丝体和子实体的其他部位及香菇子实体。菌托粗多糖进一步用DEAE纤维素柱和Sephadex G-75分离纯化,得到两个组分DRVP1与DRVP2,对分离得到的主要多糖通过高效液相色谱（HPLC）、红外光谱（IR）等进行结构分析。DRVP1的相对分子质量（Mr）为1.47×104,红外光谱数据显示为β-型甘露糖苷。体外试验表明,红托竹荪菌托多糖的组分DRVP1对小鼠S180肉瘤有一定的抑制作用。     

芦荟多糖的分离纯化及性质研究

采用水提醇沉法提取芦荟多糖,经DEAE-C32柱层析分离,Sephades G-100进一步纯化,得AⅠ、AⅡ和AⅢ三种芦荟多糖。Sephadex G-100凝胶色谱表明,AⅠ组分为均一组分,其分子量约为3.8×10~4。借助气相色谱技术,研究了芦荟粗多糖和AⅠ组分的单糖组成。另外,红外光谱鉴定芦荟多糖主要为吡喃多糖。     

沙漠生物结皮芽孢杆菌产胞外多糖的纯化及其絮凝性的研究

【目的】以新疆古尔班通古特沙漠的生物结皮为样品,通过培养、筛选、分离得到一株高产胞外多糖(EPS)的菌株XJ-27,对XJ-27菌株所产的胞外多糖进行分离纯化,并对其絮凝性进行研究。【方法】利用DEAE sepharose CL-6B阴离子层析和Sephadex G100凝胶层析的方法对胞外多糖进行纯化,通过紫外分析方法和高效凝胶渗透色谱进行纯度的测定,利用高效凝胶渗透色谱法(HP-GPC)测定其分子量,以高岭土为体系对其絮凝性进行研究。【结果】利用层析分离的方法共得到2个胞外多糖的组分,对其中一个组分进一步纯化,得到组分EPS-I。结果表明,EPS-I纯度较高,分子量为575 kD。同时对胞外多糖的絮凝性进行了研究,结果表明该胞外多糖对高岭土为体系的絮凝率为80.4%。【结论】菌株XJ-27产胞外多糖,其胞外多糖具有絮凝性,对该胞外多糖进行分离纯化后,得到分子量为575 kD的多糖组分EPS-I。     

深层培养裂褶菌胞外多糖的提取及结构研究

对深层培养裂褶菌 (Schizophyllumcommune)胞外多糖的提取工艺及多糖结构进行了初步研究。将等电点法与Sevag法相结合可高效的去除多糖中的蛋白 ,其方法简单有效。纯多糖经凝胶柱层析 ,聚丙烯酰胺凝胶电泳 ,高效液相色谱分析为均一组分 ,分子量 4×1 0 4D。通过完全水解 ,纸层析 ,气相色谱分析单糖组分 ,红外光谱 ,酶解反应 ,高碘酸氧化分析结构 ,证明了裂褶菌多糖是以葡萄糖为单一组分 ,β (1 3)和β (1 6)糖苷键组成的β D葡聚糖。     

猪肚菇多糖WPG1的相对分子质量测定及原子力显微镜观测

热水提取猪肚菇粗多糖中的酸性多糖WPG1,经凝胶纯化后用高效液相色谱（HPLC）测定其相对分子质量,用气相色谱对其单糖组成进行分析,用原子力显微镜（AFM）对其形态结构进行观测。结果表明：酸性多糖WPG1经SephacrylS-300凝胶层析纯化后得到WPG1-1和WPG1-2这2个组分; 经HPLC分析可知WPG1-1与WPG1-2均为单一组分,其相对分子质量分别为1.7×106和1.6×104; WPG1-1与WPG1-2的单糖组成主要是糖醛酸、甘露糖、葡萄糖和半乳糖; 原子力显微镜观测图分析表明WPG1-1为网链状聚集体结构,WPG1-2呈梭状聚集体,两者均非单链存在。     

荞麦麸皮多糖的分离纯化及其外貌表征的分析

采用水提醇沉法对荞麦麸皮多糖(Buckwheat bran polysaccharide,BBP)进行提取,通过DEAE-52纤维素柱层析法和Sephadex G-200对其进行分离纯化,采用凝胶过滤法对多糖组分的分子量进行测定,采用扫描电镜对荞麦麸皮多糖及其分离纯化的多糖组分的外貌进行分析,用红外光谱对分离纯化的三个荞麦麸皮多糖组分的苷键构型进行分析。结果表明:DEAE-52纤维素和Sephadex G-200对荞麦麸皮粗多糖具有较好的分离纯化效果,得到了三个多糖组分(BBP-Ⅰ、BBP-Ⅱ和BBP-Ⅲ),其分子量分别为1.56×10~4Da、5.85×10~4Da、8.45×10~4Da。扫描电镜的结果表明,BBP其表面粗糙,凹凸不平,三个分离纯化的多糖组分形貌差异较大,分别以球状、片状、棒状为主。红外光谱扫描表明BBP-Ⅰ和BBP-Ⅲ为ɑ-糖苷键化合物,BBP-Ⅱ为β-糖苷键化合物。荞麦麸皮多糖组分外貌的差异性为其进一步的结构探究提供了重要依据。     

发状念珠藻胞外多糖的纯化与性质分析

采用DEAE阴离子交换层析和Sephadex G100凝胶层析对液体悬浮培养发状念珠藻胞外多糖进行纯化, 得到两个组分NFPS1和NFPS2。对组分NFPS2进行理化性质分析, 并与野生发状念珠藻多糖NFPS0的性质进行对比。结果表明二者具有相似的单糖组成, 均为葡萄糖、木糖、半乳糖、甘露糖; 表观分子量分别为2.79×105、2.26×105; 均不含核酸、蛋白质等物质, 是非硫酸化多糖; 有较高的热稳定性, 其降解温度在245oC左右。但在微观结构上, 两者存在一定差别。     

发状念珠藻胞外多糖的纯化与性质分析

采用DEAE阴离子交换层析和Sephadex G100凝胶层析对液体悬浮培养发状念珠藻胞外多糖进行纯化, 得到两个组分NFPS1和NFPS2。对组分NFPS2进行理化性质分析, 并与野生发状念珠藻多糖NFPS0的性质进行对比。结果表明二者具有相似的单糖组成, 均为葡萄糖、木糖、半乳糖、甘露糖; 表观分子量分别为2.79×105、2.26×105; 均不含核酸、蛋白质等物质, 是非硫酸化多糖; 有较高的热稳定性, 其降解温度在245oC左右。但在微观结构上, 两者存在一定差别。     

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.