蛋白磷酸酶抑制法-荧光法检测微囊藻毒素的影响因素研究

正由于大量氮、磷等物质释放到水体中,造成严重的水体富营养化,水华的大量发生不仅影响水体感官,还释放出有害毒素如微囊藻毒素(Microcystin,MCYST)。它是一环状七肽,主要由淡水蓝藻释放到水体中,目前已经发现的微囊藻毒素有60余种异构体,其中MCYST-LR毒性最大因而对其研究最多。在长江、黄河、松花江等主要河流和太湖、滇池、巢湖、东湖等每年都有水华的发生1。因此,建立快速、灵敏、经济实用的检测微囊藻毒素的方法是微囊藻毒素研究的重要内容。本文报道了一种蛋白磷酸酶抑制法——荧光法,可以快速检测水样品中的微囊藻毒素。荧光法可采用不同的底物,本实验采用MUP(4-methy-lumbelliferylphosphatefreeacid)作为底物。当直接检测水样       

用蛋白磷酸酶抑制法比色法检测水中微囊藻毒素类物质

水体富营养化加剧水华的发生已成为全球性环境问题,水华的普遍发生使微囊藻毒素成为了一种存在广、影响大的天然有毒物,对水体尤其是富营养化水体中微囊藻毒素水平的监测是水环境监测的重要任务。       

微囊藻毒素分子致毒机理研究近况

目前,日趋严重的水体富营养化使水华发生已成为全球性环境问题,产生水华的藻类因而也受到越来越多的重视。海洋赤潮中甲藻所产生的毒素已引起人类的严重的中毒事件,虽然淡水水华还未发现引起人类急性中毒事件1,2,但由于饮用发生水华水体的水而导致家畜、家禽及野生动物死亡的事件频繁发生3,4,淡水水华已引起科学家的关注。       

微囊藻胞内毒素的提取方法

随着全球淡水水体富营养化程度的不断加剧,蓝藻水华及其毒素污染问题已经逐渐威胁到人类饮用水的安全。微囊藻(Microcystis)为常见的水华蓝藻种类,其所产生的微囊藻毒素(Microcystins,MCs)不仅会严重危害水生态系统,并且可能会给人类健康带来威胁1,2。我国云南滇池、江苏太湖和安徽巢湖等淡水湖泊均发生不同程度的蓝藻水华,并检测到了高含量MCs的存在3,4。       

微囊藻毒素生物合成及其检测的分子生物学研究进展

随着世界各地水体富营养化的日益加剧,蓝藻水华的爆发频率越来越高,爆发范围也越来越广,已经成为国内外学者高度关注的重大环境问题。微囊藻水华是淡水水体中危害最严重的一类,特别是在我国巢湖、太湖和滇池等大型湖泊,经常爆发微囊藻水华,给水体生态系统和人类健康带来了巨大的危害。本文简介了微囊藻毒素的化学结构与危害,综述了微囊藻毒素mcy基因簇、Adda生物活性结构以及肽链合成与环化等关键生物合成过程,并重点归纳了聚合酶链式反应(polymerase chain reaction,PCR)、实时定量PCR(real time quantitative PCR detecting system,QPCR)、基因芯片(gene microarray)和变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)等用于藻毒素检测的分子生物学技术方法,最后对相关研究进行了展望。     

一株囊藻毒素降解辅助菌的发现

太湖、滇池等水体爆发的蓝藻水华,对水体生态环境及人们生活带来了严重的影响,引起了各级政府的高度重视。目前每年从太湖中打捞的水华数以亿吨计,但由于其毒性较大,无法利用,同时大规模发生蓝藻的水体底泥藻毒素含量也在不断提高。微囊藻毒素(Microcystins,MCs)是由淡水藻如微囊藻属、鱼腥藻属、     

微囊藻毒素LR对大鼠肝细胞Caspase-3酶活性的影响

水体富营养化的加剧,导致藻类水华频频发生。在全球由于藻类水华所产生的毒素,对人和动物都产生了极为严重的影响,使之成为日益突出的环境问题。其中危害最严重的 是微囊藻毒素(Micnocystin,MCYST)。而微囊藻毒素LR(LR)是微囊藻毒素中存在最为普遍且毒性作用最明显的一种,是MCYST的主要代表物。       

微囊藻毒素LR对大鼠淋巴细胞DNA的损伤效应

微囊藻毒素是一类具生物活性的单环七肽,是蓝藻的一些属产生的次生代谢产物,在发生水华的水体中这类毒素普遍存在。由于水华的普遍发生,微囊藻毒素的存在已是一个令人瞩目的问题。流行病学调查发现人群原发性肝癌、大肠癌发病率与饮水源中的微囊藻毒素有关。微囊藻毒素LR(MCLR)是微囊藻毒素中最常见的一种,由于它们的高急性毒性、强促癌活性以及与人类癌症发生的相关性使其受到全球的关注。DNA是生物体内的遗传物质,它的稳定对于生命体的正常繁殖与生长是至关重要的。       

细菌溶藻的初步研究

滇池是我国西南地区的大型浅水湖泊,近十几年来,滇池蓝藻水华发生的频率和数量均明显增加。其中微囊藻(Microcystis spp.)水华是危害最严重的一类,由于这类水华发生普遍,持续时间长,而且多数产毒,危害性很大,因而倍受人们的关注。人们不断致力于微囊藻水华的消除、其毒素的降解、危害防治等方面的研究,期望减少以至消除微囊藻对生态系统和人类健康的影响。对于控制水体中有毒藻类及其负面影响乃至最终消除,人们采取了多种措施,总的说来为两种基本途径:一是控制它们在水体中的生长繁殖而保持其较低的生物量,二是采用各种办法来杀死它们。       

应用高通量实时荧光定量PCR方法筛选FL细胞对低剂量微囊藻毒素LR暴露的应答基因

微囊藻毒素是蓝藻的一些属产生的单环七肽,在发生水华的水体中普遍存在[1]。含有微囊藻毒素的水华能引起野生动物、鱼类、家畜、家禽等中毒和死亡,也对人类健康构成严重威胁[2,3]。流行病学调查发现,人群原发性肝癌、大肠癌发病率与饮水源中的微囊藻毒素有关[4]。其中微囊藻毒素LR是微囊藻毒素中最常见的一种,因其高急性毒性,强促癌活性而受到广泛的关注。有研究结果表明微囊藻毒素LR可引起多种细胞发生凋亡[5],本实验室先前的研究也发现微囊藻毒素LR能激活在凋亡过程中起重要作用的酶Caspase-3[6],及引起P53、Bax、Bcl-2等凋亡相关蛋白…     

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.