The Japanese medaka (Oryzias latipes) model: applicability for investigating the immunosuppressive effects of the aquatic pollutant benzo[a]pyrene (BaP)

Despite the fact that BaP is a carcinogen, mammalian immunosuppressant, and ubiquitous aquatic pollutant, knowledge regarding the effects of BaP on the immune system of fish is still lacking. To begin to fill this gap, studies were conducted in medaka to examine the effects and mechanisms by which BaP exposure might alter host immunocompetence. Fish, exposed by IP injection of BaP (2-600 microg/g BW), were examined after 48 h for effects upon immune function and CYP1A expression/activity. Benzo[a]pyrene, at a concentration below that which increased levels of CYPIA expression/activity (2 microg BaP/g BW) suppressed lymphocyte proliferation. Concentrations of BaP at 20 and 200 microg/g BW. suppressed antibody-forming cell (AFC) numbers, superoxide production, and host resistance against bacteria. In contrast, exposure to the low affinity aryl hydrocarbon receptor (AhR) agonist, benzo[e]pyrene (BeP), neither induced CYP1A expression nor altered immune function. Given the lack of immunosuppressive effects produced by BeP, and the fact that exposure to the AhR antagonist (and CYP1A inhibitor) alpha-naphthoflavone (ANF) ameliorated the suppressive effects of BaP upon AFC numbers, the AhR pathway (including CYP1A-mediated production of reactive BaP metabolites) appears important in mediating BaP-induced immunotoxicity in fish, as in mammals. In the past, the medaka has proven a successful model for assessing carcinogenic agents. These studies have demonstrated its utility for also determining the immunosuppressive effects of an important aquatic contaminant.     

浅层初至折射地震资料的自动解释

1 前言自先进的电子计算机和计算机处理技术引入地震勘探领域,无论是地震资料的采集,还是资料的处理解释都日趋于自动化。极大地提高了勘探精度和可靠程度。但这仅限于反射波法地震勘探。而对于折射波法发展较慢,尤其是在资料处理解释方面更是如此。对于浅层初至折射波法,由于数据量较少,其资料处理解释工作仍用人工来完成。本文根据这一情况,讨论在IBM-PC机上对浅层初至折射波地震资料进行自动解释并在绘图仪上绘制解释成果图件的实现原理与方法。并对实际资料进行了处理,经与人工解释的成果资料对比,两者非常接近。因此,用微机对初至折射资料进行自动解释代替人工解释是可行的,     

云南高原湖泊的成因类型及其分布规律的初步探讨

云南高原地处祖国西南边疆,界于北纬21°09′—29°15′、东经97°39′—106°12′之间,面积394000平方公里。西部为横断山地,东部为云贵高原的主体—滇东高原。整个地势西北高、东南低,由西北向东南倾斜。高原海拔在2,000米左右。在这辽阔的高原上,分布有滇池、洱海、抚仙湖、程海、泸沽湖、杞麓湖、异龙湖、星云湖、阳宗海、大屯海、长桥海和清水海等30余个天然湖泊,像晶莹灿烂的明珠镶嵌在广大高原群山之中。这些湖泊位于各大水系及其支流的源头,分别属于金沙江水系(滇池、程海、泸沽湖、清水海)、南盘江水系(抚仙湖、杞麓湖、星云湖、阳宗海、大屯海、长桥海)、澜沧江水系(洱海)和元江水系(异龙湖),详见图     

全球范围内天然气水合物构造背景及其稳定域研究综述

天然气水合物是人类21世纪的重要能源。目前。全球范围内共有80余处获取水合物样品。识别水合物地震标志—似海底反射(BSR)的地区更为广泛。大量的钻孔资料和地震剖面显示：主动大陆边缘的增生楔和被动大陆边缘的断裂褶皱系、泥火山、泥底辟等构造为水合物聚集成藏的有利构造环境。世界范围内不同水合物产区的温压场及稳定域特征。差别较为明显。各水合物产区的构造背景与水合物发育区的温压场环境以及稳定域的展布规律存在明显的相关关系。本文分别讨论了主动大陆边缘的增生楔(以卡斯凯迪亚为例)和被动大陆边缘的泥火山(以Hakon Mosby泥火山为例)的温压场特征、水合物聚集规律和各自的成藏模式。在此基础上。作者还进一步讨论了南海坳隆断裂带与水合物之间的关系。认为坳隆断裂带分别在气源、疏导体系(断层、砂体)和温压场环境等三方面为水合物形成提供了有利条件。     

世界海洋鲸目动物资源现状

鲸目动物传统上大体分为两类:第一类包括鲸须鲸(小露脊鲸除外)和抹香鲸;第二类包括小齿鲸和海豚。鲸目动物分布于世界各个大洋,从北极到南极的海洋都有。有些品种是全球性的,其中包括较大的第一类鲸和商业上重要的品种——蓝鲤鲸、驼背鲸、长须鲸、鳁鲸、小鳁鲸、抹香鲸和虎鲸。海洋哺乳动物资源最容易捕捞过度,因为     

A cDNA microarray technique applied for analysis of global gene expression profiles in tributyltin-exposed ascidians

To analyze global gene expressions, we constructed a cDNA microarray from a basal chordate, the ascidian Ciona intestinalis. Ciona is a cosmopolitan species and a genomic analysis of Ciona revealed that ascidians had approximately 15,500 protein-coding genes. Our "Ciona intestinalis cDNA chip version 1 (Ci cDNA chip ver. 1)" has arrayed 13,400 unique Ciona cDNAs. To establish a detection system for gene expression profiles in wild ascidians using a cDNA microarray, we analyzed gene expressions in the whole body of Ciona adults after exposure to 100 nM tributyltin (TBT) for 24 h. In our preliminary array data using Ci cDNA chip ver. 1, we found more than 200 genes that showed strong differential expressions. These genes encoded proteins that were concerned with stress response, detoxification, oxidoreduction reaction, biosynthesis, and catabolism. This, the first large cDNA microarray of this animal, should facilitate analyses of global gene expressions following exposure to TBT.