DNA polymorphism and globin chain analysis in the prenatal diagnosis of β-thalassaemia major in Taiwan

Thirty-six pregnancies in 25 families at risk of β-thalassaemia major received prenatal diagnosis. Chorionic villus sampling or amniocentesis was done in 35 pregnancies to obtain fetal cells for DNA linkage study, for which Southern blotting and DNA hybridization were used to detect seven restriction fragment length polymorphisms (RFLPs) within the β-globin gene cluster: ϵ-HincII, ^Gγ-HindIII, ^Aγ-HindIII, Φβ-HincII, 3′Φβ-HincII, β-AvaII, and 3′β BarnHI. β-Thalassaemia major was diagnosed in seven and excluded in 22 pregnancies. In the remaining six cases, β-thalassaemia major could not be excluded. In these six pregnancies and another one with late booking, ultrasound-guided cordocentesis was performed at the 22nd to 27th week of gestation. Globin chain composition was determined with urea-acetic acid-Triton X-100-12 per cent polyacrylamide gel electrophoresis. β-Thalassaemia major was diagnosed in two fetuses and excluded in the other five. Eleven fetuses (in which β-thalassaemia major was excluded) have been delivered and are healthy at more than 5 months old DNA linkage analysis coupled with globin chain electrophoresis provides an effective way for prenatal diagnosis of β-thalassaemia major, although these methods are being replaced by more direct detection techniques using oligonucleotide probes.     

单细胞凝胶电泳技术在环境污染物检测中的应用

主要介绍了单细胞凝胶电泳技术(SCGE),包括SCGE的原理、方法及其在环境污染物检测中的应用,该技术可用多种污染物的检测且灵敏度高,具有广阔的应用前景。即SCGE对大气污染物、重金属、醛类及辐射污染的检测,具有高度敏感性,是具有广阔应用前景的新技术。     

毛细管电泳中样品的在线富集

近年来,毛细管电泳以其速度快、效率高的分离分析技术受到越来越多领域的青睐,样品在线富集的方法有效的提高毛细管电泳由于进样体积小而造成的检测灵敏度难以提高的问题。文章简单介绍了毛细管电泳在线富集的原理,对其方法与应用进行了总结与概述。     

Effect of a high strength chemical industry wastewater on microbial community dynamics and mesophilic methane generation

A high strength chemical industry wastewater was assessed for its impact on anaerobic microbial com- munity dynamics and consequently mesophilic methane generation. Cumulative methane production was 251 mL/g total chemical oxygen demand removed at standard temperature and pressure at the end of 30 days experimental period with a highest recorded methane percentage of 80.6% of total biogas volume. Volatile fatty acids （VFAs） analysis revealed that acetic acid was the major intermediate VFAs produced with propionic acid accumulating over the experimental period. Quantitative analysis of microbial communities in the test and control groups with quantitative real time polymerase chain reaction highlighted that in the test group, Eubacteria （96.3%） was dominant in comparison with methanogens （3.7%）. The latter were dominated by Methanomicrobiales and Methanobacteriales while in test groups increased over the experimental period, reaching a maximum on day 30. Denaturing gradient gel electrophoresis profile was performed, targeting the 16S rRNA gene of Eubacteria and Archaea, with the DNA samples extracted at 3 different time points from the test groups. A phylogenetic tree was constructed for the sequences using the neighborhood joining method. The analysis revealed that the presence of organisms resembling Syntrophomonadaceae could have contributed to increased production of acetic and propionic acid intermediates while decrease of organisms resembling Pelotomaculum sp. could have most likely contributed to accumulation of propionic acid. This study suggested that the degradation of organic components within the high strength industrial wastewater is closely linked with the activity of certain niche microbial communities within eubacteria and methanogens.     

硝化悬浮填料塔中氨氧化细菌群落稳定性特征分析

利用PCR-DGGE分析技术,对于化学生物絮凝处理工艺中悬浮填料塔的氨氧化细菌(AOB)群落进行了研究。主要考察了曝气强度和水力停留时间2个运行参数调整的情况下,系统AOB群落结构的变化。生物膜样品直接取自硝化填料塔,多维尺度(MDS)方法用于DGGE电泳图谱的分析,分析结果以二维图形向量的方式显示,结果表明,曝气强度和水力停留时间均对AOB群落有一定的影响,主要的AOB种类在运行过程中基本不变,系统对于运行条件具有良好的稳定性。     

重金属Cr(Ⅵ)、Pb及Cu胁迫对双齿围沙蚕体腔细胞的DNA损伤

为探讨重金属Cr(Ⅵ)、Pb以及Cu对沙蚕体腔细胞DNA的毒性效应,以双齿围沙蚕为受试动物,重金属按不同剂量水平,Cr(Ⅵ):10、100和200 mg· L-1,Pb:5、50和100 mg·L-1,Cu:1、10和20 mg· L-1,分别胁迫沙蚕24 h,以不加任何重金属离子的海水为对照,采用单细胞凝胶电泳技术,检测其体腔细胞DNA损伤程度.结果表明,与空白对照组相比,3种重金属离子的各浓度组都能引起沙蚕体腔细胞DNA损伤,且3种重金属胁迫浓度与细胞DNA损伤程度之间存在显著的剂量-效应关系.双齿围沙蚕可以作为单细胞凝胶电泳的实验材料用于重金属所致环境污染的生物监测指示生物.     

重金属Cr(VI)、Pb及Cu胁迫对双齿围沙蚕体腔细胞的DNA损伤

为探讨重金属Cr(VI)、Pb以及Cu对沙蚕体腔细胞DNA的毒性效应,以双齿围沙蚕为受试动物,重金属按不同剂量水平,Cr(VI):10、100和200 mg·L~(-1),Pb:5、50和100 mg·L~(-1),Cu:1、10和20 mg·L~(-1),分别胁迫沙蚕24 h,以不加任何重金属离子的海水为对照,采用单细胞凝胶电泳技术,检测其体腔细胞DNA损伤程度。结果表明,与空白对照组相比,3种重金属离子的各浓度组都能引起沙蚕体腔细胞DNA损伤,且3种重金属胁迫浓度与细胞DNA损伤程度之间存在显著的剂量-效应关系。双齿围沙蚕可以作为单细胞凝胶电泳的实验材料用于重金属所致环境污染的生物监测指示生物。     

Variations of Bacterial Community Structure in Flooded Paddy Soil Contaminated with Herbicide Quinclorac

The denaturing gradient gel electrophoresis (DGGE) method was applied to determine the relative genetic complexity of microbial communities in flooded paddy soil treated with herbicide quinclorac (3,7-dichloro-8-quinoline-carboylic acid). The results obtained showed a significant effect of quinclorac on the development of bacterial populations in soils contaminated with different concentrations of the herbicide at the early time after application. In general, however, the number of populations of the same soil sample treated with the same concentration of the quinclorac differed obviously with increasing incubation time within the early 8 weeks. The scale of differences in banding patterns-showed that the microbial community structures of the quinclorac-treated and non-quinclorac-treated soils were not significantly different after 21 weeks of incubation. Quantification, as demonstrated in this paper, was studied by establishing dose-response relationships. Significant pattern variations were quantified. Prominent DGGE bands were excised, cloned and sequenced to gain insight into the identities of predominant bacterial populations. The majority of DGGE band sequences were related to bacterial genera Clostridium, Sphingobacterium, Xanthomonas and Rhodococcus.     

Corynebacterium glutamicum as an indicator for environmental cobalt and silver stress–A proteome analysis

Cobalt and silver are toxic for cells, but mechanisms of this toxicity are largely unknown. Analysis of Corynebacterium glutamicum proteome from cells grown in control and cobalt or silver enriched media was performed by two dimensional gel electrophoresis (2DE) followed by mass spectrometry. Our results indicate that the cell adapted to cobalt stress by inducing five defense mechanisms: Scavenging of free radicals, promotion of the generation of energy, reparation of DNA, reparation and biogenesis of Fe-S cluster proteins and supporting and reparation of cell wall. In response to the detoxification of Ag⁺ many proteins were up-regulated, which involved reparation of damaged DNA, minimizing the toxic effect of reactive oxygen species (ROS) and energy generation. Overexpression of proteins involved in cell wall biosynthesis (1,4-alpha-glucan branching enzyme and nucleoside-diphosphate-sugar epimerase) upon cobalt stress and induction of proteins involved in energy metabolism (2-methylcitrate dehydratase and 1, 2-methylcitrate synthase) upon silver demonstrate the potential of these enzymes as biomarkers of sub-lethal Ag⁺ and Co toxicity.     

高效氨氧化菌群富集、驯化及其动态变化规律分析

利用选择性培养基对氨氧化菌群进行了连续驯化,得到了氨氮去除效率稳定的氨氧化菌群。采用平板菌落计数法结合聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术考察了氨氧化菌群在连续传代过程中数量及群落结构的动态变化,并考察了pH值、碳源(HCO3-)浓度和氨氮浓度等因素对氨氧化菌群去除氨氮效率的影响。结果表明,通过连续驯化,氨氧化菌的比例由最初的1.8%提高到了31.3%。在碳源浓度为1.5 mg/L,NH4+-N初始浓度为200 mg/L,pH值为8的条件下,菌群对氨氮的去除率达99%以上。