Detection of both the normal and mutant alleles in single cells of individuals heterozygous for the sickle cell mutation—prelude to preimplantation diagnosis

As a preliminary step to preimplantation diagnosis of sickle cell disease in unfertilized eggs or 8-cell embryos of heterozygous parents, we established quality control for detection of the mutant and normal alleles of the beta-haemoglobin gene using single buccal cells. Efficient polymerase chain reaction (PCR) amplification of a 680 base pair sequence of the beta-globin gene spanning the site of the sickle cell mutation was obtained for 79 per cent of single heterozygous cells. In 71 per cent of cases, both alleles were detected. With this current efficiency, we predict that a clinical preimplantation diagnosis at the 8-cell embryo stage could be carried out safely and reliably for a couple at risk of transmitting sickle cell disease to their children.     

Erythroid-specific antibodies enhance detection of fetal nucleated erythrocytes in maternal blood

Fetal nucleated erythrocytes (NRBC) in maternal blood are a non-invasive source of fetal DNA for prenatal genetic screening. We compared the effectiveness of three monoclonal antibodies for the separation of fetal cells from maternal blood by flow sorting. Mononuclear blood cells from 49 healthy pregnant women were incubated with antibody to CD 71, CD 36, and/or glycophorin A (GPA), employed singly or in combination with each other. These monoclonal antibodies recognize surface antigens on haematopoietic precursor cells. Successful isolation of fetal cells was defined as detection of Y chromosomal sequences in maternal blood from women carrying male fetuses, with absence of Y sequences when female fetuses were carried. Thus, gender prediction accuracy was used as a measure of fetal cell separation. Using anti-CD 71 to isolate fetal cells, gender prediction was 57 per cent correct; with anti-CD 36, it was 88 per cent correct. Anti-GPA, an erythrocyte-specific antigen, used alone or in combination with anti-CD 71 or 36, improved gender prediction to 100 per cent. We conclude that antibody to GPA improves the retrieval of fetal NRBC from maternal blood, permitting genetic analysis by the polymerase chain reaction.     

阿尔山——柴河旅游区环境本底情况、主要污染物种类、排放水平及污染防治对策

文章根据柴河旅游区自然地理概况及环境质量现状调查以及一些现场调研。结合阿尔山市市区环境大气、哈拉哈河、绰尔河水质监测数据，对柴河旅游区污染物种类、排放进行全面详细分析。并提出了污染防治对策。     

建立能够体现化工行业特点的行业排放标准初探

化工行业具有传统的工业类型和新兴产业交叉渗透的特点。现有的污染物排放标准因涵盖行业过多、细化内容不够、可操作性不强、行业特点不突出,故不太适应化工行业的发展,建立新的化工行业污染物排放标准势在必行。文章概要介绍了我国现有污染物排放标准,分析了美国、欧盟、日本、德国等一些国家和组织的排放标准,提议建立能够体现化工行业特点的行业排放标准,以达到淘汰落后工艺和促进清洁工艺的目的。     

环境质量的灰色聚类评价

灰色聚类评价是环境质量等级研究的一种简单易行的方法。本文利用灰色聚类评价的原理和方法来确定环境质量的等级问题 ,物理意义十分明确 ,避免了建立数学模式和计算综合指数等中间环节。     

环境工程设计质量保障体系探讨

以污水处理工程为例，阐明环境工程设计质量保障体系的构成，概述设计原则以及每一设计步骤所需注意的问题，对验证、确保设计质量的后续工作过程作了简要的介绍。     

生命周期评估——开展环境管理的重要工具

作为一项环境管理工具，生命周期评估逐渐被广泛了解和接受．本文从生命周期评估的定义入手，阐述了生命周期评估的框架及应用原则和思路     

综合评分指标体系在环境优先污染物筛选中的应用

介绍了一种用于环境优先污染物筛选的综合评分指标体系，并以上海市石化行业废气优先污染物的筛选为实例说明。     

Chorionic villus culture for prenatal diagnosis of chromosome defects: Reduction of the long-term cultivation time

We report in detail two series of chorionic villus cultivation for prenatal chromosomal diagnosis. Chorionic villi were sampled from both first- and second-trimester pregnancies. One hundred cultures were treated with trypsin–EDTA for 2 h and collagenase overnight, (method A) and 100 were treated with trypsin–EDTA for 1 h and collagenase for 2 h (method B). Using short-term enzymatic digestion, the cultivation time was reduced from 14 days to 6 days. Sufficient amounts of metaphases of good quality were present in 93 per cent of primary cultures harvested in situ, whereas enough metaphases of sufficiently good quality were in most cases present only after subcultivation of the cultures using method A. The decrease in cultivation time obtained is probably due to a higher yield of viable cells in monocellular suspension, an increased attachment efficiency, and a more rapid attachment of single cells (within 24 h).     

环境价值评估方法综述

对目前国内外的环境价值评估方法进行了综述，并提出了一套适合我国国情的价值评估方法，该方法分为１４类２９个指标，作为完善我国环境价值评估体系的一种建议提出。