印楝油对印楝素的增效作用和保护作用

印楝油对印楝素具有增效作用,印楝素A和印楝种子石油醚抽提物和印楝种子植物油分别按1：10(m／m)混用处理斜纹夜蛾3龄幼虫,共毒系数分别为150．17和226．87,印楝素B和两者混用后的共毒系数分别为166．00和242．18。印楝种子植物油对印楝素具有保护作用,在54℃下热贮7d,印楝油(甲醇：印楝油=9-1,v／v)对印楝素A和印楝素B的保护效果分别为56．96％和50．86％;热贮14d,保护效果分别为26．72％和38．42％。     

大叶山楝根的化学成分及细胞毒活性研究

该研究从大叶山楝根95%乙醇提取物的乙酸乙酯萃取物中分离得到10个化合物,经波谱解析分别鉴定为schleicheol 2(1),β-扶桑甾醇(2),fregenedadiol(3),异巴西红厚壳素(4),丁香酯素(5),表丁香酯素(6),graminone A(7),sylvatesmin(8),Z-6-十九烯酸甲酯(9),棕榈酸(10)。其中,化合物1-4、化合物7-9为首次从山楝属植物中分离得到。细胞毒活性测试结果表明,化合物1和化合物2对人胃癌细胞SGC-7901生长具有一定的抑制活性。     

印楝属(Azadirachta A. Juss.)植物分类及分布的研究现状

印楝属(Azadirachta A.Juss.)属楝科(Meliaceae)。印楝属植物由印度-马来亚(Indo-Malesian)特有成分组成,目前,世界分布(天然分布和栽培分布)约80个国家。现在得到公认并广泛使用的印楝属,传统上被归入楝属(Melia L.),由于与楝科的Antelaea、Azedarach和Trichilia的亲缘关系相近、形态特征相似,在属的归属上和种的确定上有较大的争议,被正式描述的"属"和"种"分别为5属、11种。从传统分类学水平,分析回顾了印楝属的系统位置、分类的现状与问题。并根据其地理分布,综述了印楝属植物的原产地及当今世界分布情况。     

印楝内生真菌棘孢曲霉YM 311498的代谢产物研究

从印楝植物内生真菌棘孢曲霉（Aspergillus aculeatus）YM311498的发酵液提取物中分离得到4个化合物,通过波谱技术分别鉴定为大黄酚（1）、大黄素（2）、琥珀酸（3）、柠檬酸二甲酯（4）,以上化合物均为首次从该种真菌中分离得到。     

印楝植物内生真菌Phomopsis sp.的代谢产物研究

从印楝植物内生真菌Phomopsis sp．的菌丝体提取物中分离得到4个化合物,通过波谱技术分别鉴定为水苏碱（1）、甲基-β-D-葡萄糖苷（2）、过氧化麦角甾醇（3）、腺嘌呤核苷（4）,这些化合物均为首次从该属真菌中分离得到。     

印楝愈伤组织开矿及其印楝素含量测定

取印楝不同器官作外植体,研究培养基和继代次数对愈伤组织生长及其印楝素生物合成的影响。印楝的不同器官（根、叶、茎及皮）均能诱导出愈伤组织,这些愈伤组织均有合成印楝素的能力。其中以叶诱导的愈伤组织生长速率及印楝素含量为最高。含有较低铵盐的Ｂ５培养基有利于细胞生长,含有较高铵盐的ＭＳ培养基有利于印楝素积累,不含铵盐的Ｗｈｉｔｅ培养基对两者均不利。愈伤组织继代２－３代,有利于愈伤组织生长和印楝素合成。     

印楝素A与印楝素B对粉纹夜蛾BTI-Tn-5B1-4的细胞毒性

为了明确印楝素A和B活性差异的机理,本研究比较了印楝素A和印楝素B对粉纹夜蛾Trichoplusia ni离体培养胚胎细胞系BTI-Tn-5B1-4的毒性。结果表明：印楝素A与印楝素B对BTI-Tn-5B1-4细胞具有良好的增殖抑制活性,处理后3 d,其IC₅₀值分别为2.9 μg/mL和9.85 μg/mL,印楝素A的细胞毒力显著高于印楝素B。倒置显微镜观察发现,印楝素A和印楝素B处理可导致细胞变形,贴壁能力下降,并出现明显空泡,印楝素A的影响明显高于印楝素B。流式细胞仪检测结果表明,印楝素可导致BTI-Tn-5B1-4细胞体积显著膨大,印楝素A处理细胞体积增大程度显著高于印楝素B;印楝素可以明显影响BTI-Tn-5B1-4细胞膜电位,1.25 μg/mL印楝素A和印楝素B处理后3 d,细胞DiBAC4（3）荧光强度分别增加88.12%和55.37%,印楝素A的影响显著高于印楝素B。荧光显微镜观察发现,印楝素对BTI-Tn-5B1-4细胞核具有明显影响,印楝素B的影响明显高于印楝素A,印楝素B处理后,细胞核受损细胞数更多,受损程度更严重。结果显示印楝素A和印楝素B的细胞作用机理存在差异,本研究从细胞学水平解释了印楝素的生长发育抑制作用机理。     

印楝愈伤组织形成及其印楝素含量测定

取印楝（AzadirachtaindicaA．Juss）不同器官作外植体,研究培养基和继代次数对愈伤组织生长及其印楝素（Azadirachtin）生物合成的影响．印楝的不同器官（根、叶、茎及皮）均能诱导出愈伤组织,这些愈伤组织均有合成印楝素的能力．其中以叶诱导的愈伤组织生长速率及印楝素含量为最高．含有较低按盐的B5培养基有利于细胞生长,含有较高铵盐的MS培养基有利于印楝素积累,不含铰盐的White培养基对两者均不利．愈伤组织继代2—3代,有利于愈伤组织生长和印楝素合成。     

大蒜果树的化学成分

从大蒜果树（Dysaxylum hainanense Merr),树皮的乙醇提取物中分离得到10个化合物,通过波谱方法鉴定它们分别是（＋）evofolinB(1),20S,24-epoxy-24,25-dihydroxy-3,4-secodanmar-4(28)-en-3-oic acid(2),4(14)-eudesmene-6?,11-diol(3),stigmast-5-ene-3β－7a-diol(4),stigmast-5-en-eβ－ol lioleate(5),sitindosideI(6),methyl3,4-dihdroxy-benzoate(7),scopoletin(8),β-谷甾醇和胡萝卜甙,其中1为新化合物。     

印楝素A和印楝素B对棉铃虫生长发育的影响

为了明确印楝素A和印楝素B生物活性的差异,选用印楝素A和印楝素B对棉铃虫生长发育的影响进行了比较研究。结果表明:印楝素A和印楝素B对棉铃虫3龄幼虫具有良好的拒食活性,5μg/mL处理48 h对棉铃虫3龄幼虫的拒食率分别为85.17%和69.02%。分别用含有药剂(1μg/mL)的饲料饲喂棉铃虫5龄幼虫,结果表明:印楝素A和印楝素B能够明显抑制棉铃虫5龄幼虫的体重增长,处理14 d后幼虫的体重分别下降50.28%和43.08%,仅有少量个体化蛹,化蛹率分别为26.67%和13.33%。进一步的羽化结果表明:经印楝素A和印楝素B处理的虫蛹均未能完成羽化。综合各阶段试验结果来看,印楝素A和印楝素B的生物活性存在差异,印楝素B对棉铃虫生长发育的抑制作用高于印楝素A。     

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.