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141.
142.
V. Gopal S. Parvathy P. R. Balasubramanian 《Environmental monitoring and assessment》1997,48(2):117-124
Cyprinus carpio were exposed to two non-essential (Hg and Pb)and two essential (Cu and Ni) heavy metal salts at lethal andsub-lethal concentrations. Blood serum total protein, serum globulinand serum albumin was analysed every 2 hr for 24 hrs andagain at 48 and 72 hrs. Serum protein and globulin level showedan intial sharp increase from 2 to 20 hrs, followed by decline thatextend over a period of 72 hrs. Serum albumin showed an initialimmediate decline from 2 to 4 hrs, followed by an intermittent period of recovery and decline that extend over a period of 72hrs. Both lethal and sub-lethal concentrations of metal salts elicited asimilar pattern of response varying only in magnitude. The use offish blood serum protein, albumin and globulin measurements as general indicators of pollutant stress response isdiscussed. 相似文献
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Sanchez-Hernandez JC Wheelock CE 《Environmental pollution (Barking, Essex : 1987)》2009,157(1):264-272
A laboratory-based study was conducted to determine the basal carboxylesterase (CbE) activity in different tissues of the earthworm Lumbricus terrestris, and its sensitivity to the organophosphate (OP) pesticide chlorpyrifos-oxon (CPx). Carboxylesterase activity was found in the pharynx, crop, gizzard, anterior intestine, wall muscle and reproductive tissues of L. terrestris, and multiple tissue-specific isozymes were observed by native gel electrophoresis. Esterase activity and sensitivity to CPx inhibition varied on a tissue- and substrate-specific basis, suggesting isoforms-specific selectivity to OP-mediated inhibition. Three practical issues are recommended for the use of earthworm CbE activity as a biomarker of pesticide exposure: (i) CbE should be measured using several routine substrates, (ii) it should be determined in selected tissues instead of whole organism homogenate, and (iii) earthworm CbE activity should be used in conjuncture with other common biomarkers (e.g., ChE) within a multibiomarker approach to assess field exposure of OPs, and potentially other agrochemicals. 相似文献
145.
Moreno B Vivas A Nogales R Macci C Masciandaro G Benitez E 《Environmental science and pollution research international》2009,16(3):253-264
Background, aim, and scope In this work, the potential for using olive-mill solid waste as an organic amendment for biochemical and biological restoration
of a trichloroethylene-contaminated soil, which has previously been stabilized through vermicomposting processes, has been
explored.
Materials and methods Trichloroethylene-contaminated water was pumped into soil columns with a layer of vermicompost at 10-cm depth (biobarrier
system). The impacts of the trichloroethylene on the microbial community were evaluated by determining: (1) the overall microbial
activity (estimated as dehydrogenase activity) and enzyme activities related to the main nutrient cycles (β-glucosidase, o-diphenoloxidase, phosphatase, urease, and arylsulphatase activities). In addition, isoelectric focusing of the soil extracellular
humic-β-glucosidase complexes was performed to study the enzymatically active humic matter related to the soil carbon cycle.
(2) The soil bacterial diversity and the molecular mechanisms for the bacterial resistance to organic solvents were also determined.
For this, polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) was used to detect changes in bacterial
community structure and PCR-single-strand conformational polymorphism (SSCP) was developed and optimised for detection and
discrimination of the resistance-nodulation-division (RND) genes amplified from the contaminated soils.
Results Vermicompost reduced, with respect to the unamended soil, about 30% of the trichloroethylene leaching during the first month
of the experiment. Trichloroethylene had a marked negative effect on soil dehydrogenase, β-glucosidase, urease, phosphatase,
and arylsulphatase activities. Nevertheless, the vermicompost tended to avoid this toxic effect. Vermicompost also displays
stable humic-β-glucosidase complexes that increased the extracellular activity related to C-cycle in the contaminated soils.
The isoelectric focusing technique showed a more biochemically active humic matter in the soil sampled under the vermicompost.
The behaviour of the three main phyla of bacteria isolated from the DGGE bands was quite different. Bands corresponding to
Actinobacteria disappeared, whereas those affiliated with Proteobacteria remained after the trichloroethylene contamination. The disappeared Actinobacteria became visible in the soil amended with the vermicompost. Bands corresponding to Bacteriodetes appeared only in columns of contaminated soils. In this study, six types of RND proteins were detected by PCR-SSCP in the
natural soil, three in the trichloroethylene-contaminated soil and 7/5 in trichloroethylene-contaminated soil above/below
the vermicompost in the biobarrier columns. Trichloroethylene tended to reduce or eliminate all the clones detected in the
uncontaminated soil, whereas new efflux pumps appeared in the biobarrier columns.
Discussion Although enzymes incorporated into the humic substances of vermicomposted olive wastes are quite stable, trichloroethylene
also inhibited the background levels of the soil extracellular β-glucosidase activity in the amended soils. The decrease was
less severe in the biobarrier system, but in any case, no relation was found between the levels of trichloroethylene in soil
and extracellular β-glucosidase activity, or between the latter and the quantity of humic carbon in soils. The isoelectric
focusing technique was carried out in the humic fraction to determine whether the loss of activity occurred in overall extracellular
β-glucosidase or in that linked to stable humic substances (humic–enzyme complexes). The contaminated soils showed the lower
enzyme activities, whereas contaminated and amended soils presented greater quantity of focalised (and therefore stable) humic
carbon and spectra heterogeneity: very different bands with higher enzyme activities. No clear relationship between trichloroethylene
concentration in soil and diversity of the bacterial population was noted. Similar patterns could be found when the community
structures of bacteria and microbial activity were considered. Since the use of the dehydrogenase assay has been recognised
as a useful indicator of the overall measure of the intensity of microbial metabolism, these results could be attributed to
PCR-DGGE methodology, since the method reveals the presence of dominant populations regardless of their metabolic state. Trichloroethylene
maintained or even increased the number of clones with the DNA encoding for RND proteins, except for the contaminated soil
located above the vermicompost. However, the main effect of trichloroethylene was to modify the structure of the community
in contaminated soils, considering the type of efflux pumps encoded by the DNA extracted from soil bacteria.
Conclusions Trichloroethylene inhibited specific functions in soil and had a clear influence on the structure of the autochthonous bacterial
community. The organic matter released by the vermicomposted olive waste tended to avoid the toxic effect of the contaminant.
Trichloroethylene also inhibited the background levels of the soil extracellular β-glucosidase activity, even when vermicompost
was present. In this case, the effect of the vermicompost was to provide and/or to stimulate the humic-β-glucosidase complexes
located in the soil humic fraction >104, increasing the resistance of the enzyme to the inhibition. The bacterial community from the soil presented significantly
different mechanisms to resistance to solvents (RND proteins) under trichloroethylene conditions. The effect of the vermicompost
was to induce these mechanisms in the autochthonous bacterial community and/or incorporated new bacterial species, able to
grow in a trichloroethylene-contaminated ambient. Coupled biochemical and molecular methodologies are therefore helpful approaches
in assessing the effect of an organic amendment on the biochemical and biological restoration of a trichloroethylene-contaminated
soil.
Recommendations and perspectives Since the main biochemical and biological effects of the organic amendment on the contaminated soil seem to be the incorporation
of biochemically active humic matter, as well as new bacterial species able to grow in a trichloroethylene-contaminated ambient,
isoelectric focusing and PCR-SSCP methodologies should be considered as parts of an integrated approach to determine the success
of a restoration scheme. 相似文献
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147.
卤代酚复合污染对鲤科金鱼的生化毒性效应研究 总被引:1,自引:0,他引:1
为探讨卤代酚复合污染对水生生物的联合毒性效应,探究较为可靠的检测方法,根据所选6种卤代酚化学结构的相似程度和48 h LC50值,将其分为3组二元混合物进行急性暴露实验, 毒性单位比为1∶1,每组分2个浓度级别观察金鱼生物学行为的变化,同时检测金鱼肝脏中3种抗氧化酶(SOD,CAT和GSH-Px)活性以及酶活性影响率的变化. 结果表明:3组卤代酚对金鱼肝脏中3种抗氧化酶的酶活性影响率变化均有显著性差异(P<0.01);3种抗氧化酶中仅SOD在1/2LC50剂量暴露组中均表现为明显升高的酶活性激活率或酶活性抑制率,提示SOD较适合作为卤代酚低浓度复合水污染情况监测的生物化学检测指标. 相似文献
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149.
Philip R. Reilly 《黑龙江环境通报》2009,29(9):829-832
The recently enacted federal law, the ‘Prenatally and Postnatally Diagnosed Conditions Awareness Act’ (United States Public Law 110–374) seeks to improve opportunities for parents and pregnant women to anticipate and understand the likely life course of children born with Down syndrome and other (unspecified) conditions. The law is in part a response to the continued growth of prenatal screening and testing. For example, the American College of Obstetricians and Gynecologists' Practice Bulletin 77 recommends that ‘Screening and invasive diagnostic testing for aneuploidies be available to all women who present for prenatal care before 20 weeks of gestation regardless of maternal age.’ Emerging technologies anticipate an era in which the scope of prenatal screening and testing will be much larger than it is today. Inevitably, more women will find themselves facing the hard question of whether to continue or end a pregnancy in which a fetus has been found to have a significant abnormality. While the new federal law is not likely to have a major impact on obstetric practice, it may be a harbinger of renewed wide-scale public debate concerning the ethics of prenatal screening. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
150.