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Sökning: WFRF:(Reifferscheid Georg)

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1.
  • Behnisch, Peter, et al. (författare)
  • Results of an international interlaboratory study on dioxin-like activities in drinking-, river surface- and wastewater using DR CALUX bioassay
  • 2024
  • Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 920
  • Tidskriftsartikel (refereegranskat)abstract
    • Aquatic animals and consumers of aquatic animals are exposed to increasingly complex mixtures of known and as-yet-unknown chemicals with dioxin-like toxicities in the water cycle. Effect- and cell-based bioanalysis can cover known and yet unknown dioxin and dioxin-like compounds as well as complex mixtures thereof but need to be standardized and integrated into international guidelines for environmental testing. In an international laboratory testing (ILT) following ISO/CD 24295 as standard procedure for rat cell-based DR CALUX un-spiked and spiked extracts of drinking-, surface-, and wastewater were validated to generate precision data for the development of the full ISO-standard. We found acceptable repeatability and reproducibility ranges below 36 % by DR CALUX bioassay for the tested un-spiked and spiked water of different origins. The presence of 17 PCDD/Fs and 12 dioxin-like PCBs was also confirmed by congener-specific GC-HRMS analysis. We compared the sum of dioxin-like activity levels measured by DR CALUX bioassay (expressed in 2,3,7,8-TCDD Bioanalytical Equivalents, BEQ; ISO 23196, 2022) with the obtained GC-HRMS chemical analysis results converted to toxic equivalents (TEQ; van den Berg et al., 2013).
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2.
  • Böttcher, Melanie, et al. (författare)
  • Comparison of in vitro and in situ genotoxicity in the Danube River by means of the comet assay and the micronucleus test
  • 2010
  • Ingår i: Mutation research. Genetic toxicology and environmental mutagenesis. - Amsterdam, Neteherlands : Elsevier. - 1383-5718 .- 1879-3592. ; 700:1-2, s. 11-17
  • Tidskriftsartikel (refereegranskat)abstract
    • Genotoxicity can be correlated with adverse reproductive effects or may even result in elevated extinction risk for particular species of an ecosystem. It may thus be a valuable tool for screening of pollution and potential environmental harm. Since many genotoxicants tend to adsorb on to particulate matter, sediments and suspended materials are of particular interest for genotoxicity screening under field conditions. In order to correlate the genotoxic potential of sediments with genetic damage in fish, rainbow-trout liver (RTL-W1) cells were exposed in vitro to acetone extracts of sediments collected at 10 selected sites along the upper Danube River and analyzed in the comet and micronucleus assays. These in vitro results were compared with micronucleus formation in erythrocytes of the European barbel (Barbus barbus) caught int he field. The two in vitro bioassays showed excellent correlation, indicating comparability of genotoxic potentials in vitro. Sampling sites could be clearly differentiated with respect to severity of effects, with Rottenacker as the most heavily contaminated site, Ehingen and Schwarzach as moderately genotoxic,and with the weakest effects in the tributary Lauchert. All other sediment extracts showed intermediate genotoxic or clastogenic effects. In situ, micronucleus formation in barbel erythrocytes indicated severe genotoxicity at Rottenacker, moderate effects at Ehingen, but minor contamination at Riedlingen and Sigmaringen. In situ observations thus showed excellent correlation with corresponding in vitro tests and document the ecological relevance of in vitro studies with sediment extracts. With respect to the ecological status of the Danube River, the results overall indicate a moderate to severe genotoxic potential with a highly differential localization.
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3.
  • Eichbaum, Kathrin, et al. (författare)
  • In vitro bioassays for detecting dioxin-like activity : Application potentials and limits of detection, a review
  • 2014
  • Ingår i: Science of the Total Environment. - Amsterdam : Elsevier. - 0048-9697 .- 1879-1026. ; 487, s. 37-48
  • Tidskriftsartikel (refereegranskat)abstract
    • Use of in vitro assays as screening tool to characterize contamination of a variety of environmental matrices has become an increasingly popular and powerful toolbox in the field of environmental toxicology.While bioassays cannot entirely substitute analytical methods such as gas chromatography-mass spectrometry (GC-MS), the increasing improvement of cell lines and standardization of bioassay procedures enhance their utility as bioanalytical pre-screening tests prior to more targeted chemical analytical investigations. Dioxin-receptor-based assays provide a holistic characterization of exposure to dioxin-like compounds (DLCs) by integrating their overall toxic potential, including potentials of unknown DLCs not detectable via e.g. GC-MS. Hence, they provide important additional information with respect to environmental risk assessment of DLCs.This review summarizes different in vitro bioassay applications for detection of DLCs and considers the comparability of bioassay and chemical analytically derived toxicity equivalents (TEQs) of different approaches and various matrices. These range from complex samples such as sediments through single reference to compound mixtures. A summary of bioassay derived detection limits (LODs) showed a number of current bioassays to be equally sensitive as chemical methodologies, but moreover revealed that most of the bioanalytical studies conducted to date did not report their LODs, which represents a limitation with regard to low potency samples.
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4.
  • Eichbaum, Kathrin, et al. (författare)
  • The dioRAMA project : assessment of dioxin-like activity in sediments and fish (Rutilus rutilus) in support of the ecotoxicological characterization of sediments
  • 2013
  • Ingår i: Journal of Soils and Sediments. - : Springer. - 1439-0108 .- 1614-7480. ; 13:4, s. 770-774
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Given the complex interactions of re-suspension processes and bioavailability of sediment-bound pollutants such as dioxin-like chemicals, there is need for a better integrative understanding of the cause-effect relationship of these pollutants. Currently, the majority of studies investigating potential risks of these chemicals only focus on characterizing sediment extracts via in vitro bioassays, thereby disregarding bioavailability, uptake, metabolism, and elimination rates of these compounds in vivo. To determine to which extent mechanism-specific effects in vitro reflect possible adverse effects in vivo, the research project dioRAMA, involving partnership between the Institute for Environmental Research of RWTH Aachen University and the Department Biochemistry/Ecotoxicology of the German Federal Institute of Hydrology, was established.Methods: Animals from an elevated trophic level-common roach (Rutilus rutilus)-will be exposed to sediments from two major German rivers. Exposure will be performed in a system that enables a concurrent monitoring of environmental parameters. In parallel, in vitro studies will be conducted to determine dioxin-like potentials of sediment and fish extracts from the in vivo exposure experiments using different cell lines with varying endpoints. Moreover, extract fractionation procedures, using the strategy of effect-directed analysis, will enable the detection of specific contaminant groups responsible for the biological activity observed.Conclusion: A closer interconnection between applied ecotoxicological science and regulatory needs will facilitate the improved assessment of dioxin-like compounds in sediment and biota. Consequently, this will enable their application in sediment management programs, which is one of the main goals of the dioRAMA project.
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5.
  • Gallampois, Christine M. J., et al. (författare)
  • Integrated biological-chemical approach for the isolation and selection of polyaromatic mutagens in surface waters
  • 2013
  • Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Berlin/Heidelberg. - 1618-2642 .- 1618-2650. ; 405:28, s. 9101-9112
  • Tidskriftsartikel (refereegranskat)abstract
    • Many environmental mutagens, including polyaromatic compounds are present in surface waters, often in complex mixtures and at low concentrations. The present study provides and applies a novel, integrated approach to isolate polyaromatic mutagens in river water using a sample from the River Elbe. The sample was taken downstream of industrial discharges using blue rayon (BR) as a passive sampler that selectively adsorbs polyaromatic compounds and was subjected to effect-directed fractionation in order to characterise the compounds causing the detected effect(s). The procedure relies on three complementary fractionation steps, the Ames fluctuation assay with strains TA98, YG1024 and YG1041 with and without S9 activation and analytical screening. Several mutagenic fractions were isolated by combining mutagenicity testing with fractionation. The enhanced mutagenicity in the nitroreductase and/or O-acetyltransferase overexpressing strains YG1024 and YG1041 strains suggested amino- and/or nitro-compounds causing mutagenicity in several fractions. Analytical screening of mutagenic fractions with LC-HRMS/MS provided a list of molecular formulas typically containing one to ten nitrogen and at least two oxygen atoms supporting the presence of amino and nitro-compounds in the mutagenic fractions.
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6.
  • Hollert, Henner, et al. (författare)
  • Eine Weight-of-Evidence-Studie zur Bewertung der Sedimentbelastung und des Fischrückgangs in der Oberen Donau [Assessing sediments and fish health using a weight-of-evidence approach : in search for the causes of fish decline in the Danube river]
  • 2009
  • Ingår i: Umweltwissenschaften und Schadstoff-Forschung. - Berlin : Springer. - 0934-3504 .- 1865-5084. ; 21:3, s. 260-263
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and aim Despite intensive and continuous stocking and improvement of water quality since the 1970s, fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River (Germany). In order to assess 1) possible links between molecular/biochemical responses and ecologically relevant effects, and 2) if ecotoxicological effects might be related to the decline in fish catches in the upper Danube river, sediment samples and fish were collected at different locations and analyzed using a weight-of-evidence (WOE) approach with several lines of evidence. The objective of the presentation is to introduce the conceptual framework and to review results of the ongoing study. As previously addressed by Chapman and Hollert (2006) a variety of lines of evidence can be used in WOE studies. Briefly, 1) a comprehensive battery of acute and mechanism-specific bioassays was used to characterize the ecotoxicological hazard potential. 2) Histopathological investigations and the micronucleus assay with erythrocytes were applied, analyzing in situ parameters. 3) Diversity and abundance of benthic macroinvertebrates and fish as well as 4) persistent organic pollutants, endocrine disrupting substances, limnochemical parameters and the concentration of heavy metals were recorded. To identify organic contaminants a spotential causes of sediment toxicity assays, 5) effect directed analysis was applied. © 2009 Springer-Verlag.
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7.
  • Keiter, Steffen, 1971-, et al. (författare)
  • DanTox-a novel joint research project using zebrafish (Danio rerio) to identify specific toxicity and molecular modes of action of sediment-bound pollutants
  • 2010
  • Ingår i: Journal of Soils and Sediments. - Heidelberg, Germany : Springer. - 1439-0108 .- 1614-7480. ; 10:4, s. 714-717
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: The European Water Framework Directive aimsto achieve a good ecological and chemical status in surface water of European rivers by the year 2015. Since sediments and particulate matter act as secondary sources for pollutants, applied sediment toxicology is perceived to play a major rolefor obtaining new knowledge that can contribute to successful attainment of the goal. However, the existing bioassays for sediment toxicity analyses do not provide sufficient data concerning bioavailability of environmental pollutants. In this regard, there is an urgent need to combine sediment contact assays with gene expression analysis to investigate mechanism-specific sediment toxicity.Purpose: The aim of the novel joint research project is todevelop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR).Current ecotoxicological research customarily involves a battery of bioassays to cover different toxicological endpoints (e.g., teratogenicity, genotoxicity, mutagenicity, Ah-receptor mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression offer deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular kinds of toxic response. Gene expression profiles reflect the way cells and organisms adapt or respond to a changing environment.Conclusion: The present project aspires to increase the fundamental molecular and physiological knowledge concerning the mode of action of environmental toxicants in zebrafish (Danio rerio). By working with partners from the academic and research institutions as well as from industry and waterway regulations, the success of this basic research-driven joint project in terms of development and implementation of novel sediment toxicity methods will be realized.
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8.
  • Kosmehl, Thomas, et al. (författare)
  • A combined DNA-microarray and mechanism-specific toxicity approach with zebrafish embryos to investigate the pollution of river sediments
  • 2012
  • Ingår i: Reproductive Toxicology. - Oxford, United Kingdom : Elsevier. - 0890-6238 .- 1873-1708. ; 33:2, s. 245-253
  • Tidskriftsartikel (refereegranskat)abstract
    • The zebrafish embryo has repeatedly proved to be a useful model for the analysis of effects by environmental toxicants. This proof-of-concept study was performed to investigate if an approach combining mechanism-specific bioassays with microarray techniques can obtain more in-depth insights into theecotoxicity of complex pollutant mixtures as present, e.g., in sediment extracts. For this end, altered gene expression was compared to data from established bioassays as well as to results from chemical analysis. Mechanism-specific biotests indicated a defined hazard potential of the sediment extracts, and microarray analysis revealed several classes of significantly regulated genes which could be related to the hazard potential. Results indicate that potential classes of contaminants can be assigned to sediment extracts by both classical biomarker genes and corresponding expression profile analyses of known substances. However, it is difficult to distinguish between specific responses and more universal detoxification of the organism.
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9.
  • Wernersson, Ann-Sofie, 1969, et al. (författare)
  • The European technical report on aquatic effect-based monitoring tools under the water framework directive
  • 2015
  • Ingår i: Environmental Sciences Europe. - : Springer Science and Business Media LLC. - 2190-4715 .- 2190-4707. ; 27:11 March 2015
  • Tidskriftsartikel (refereegranskat)abstract
    • The Water Framework Directive (WFD), 2000/60/EC, requires an integrated approach to the monitoring and assessment of the quality of surface water bodies. The chemical status assessment is based on compliance with legally binding Environmental Quality Standards (EQSs) for selected chemical pollutants (priority substances) of EU-wide concern. In the context of the mandate for the period 2010 to 2012 of the subgroup Chemical Monitoring and Emerging Pollutants (CMEP) under the Common Implementation Strategy (CIS) for the WFD, a specific task was established for the elaboration of a technical report on aquatic effect-based monitoring tools. The activity was chaired by Sweden and co-chaired by Italy and progressively involved several Member States and stakeholders in an EU-wide drafting group. The main aim of this technical report was to identify potential effect-based tools (e.g. biomarkers and bioassays) that could be used in the context of the different monitoring programmes (surveillance, operational and investigative) linking chemical and ecological status assessment. The present paper summarizes the major technical contents and findings of the report.
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