Blar i NIVA Open Access Archive på forfatter "Tollefsen, Knut Erik"
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17α-Ethinylestradiol (EE2) effect on global gene expression in primary rainbow trout (Oncorhynchus mykiss) hepatocytes
Hultman, Maria Therese; Song, You; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2015)The potential impact of endocrine disrupting chemicals (EDCs) in the aquatic environment has driven the development of screening assays to evaluate the estrogenic properties of chemicals and their effects on aquatic organisms ... -
Adverse outcome pathways (AOPs) for radiation-induced reproductive effects in environmental species: state of science and identification of a consensus AOP network
Tollefsen, Knut Erik; Alonzo, Frederic; Beresford, Nicholas A.; Brede, Dag Anders; Dufourcq-Sekatcheff, Elizabeth; Gilbin, Rodolphe; Horemans, Nele; Hurem, Selma; Laloi, Patrick; Maremonti, Erica; Oughton, Deborah Helen; Simon, Olivier; Song, You; Wood, Michael; Xie, Li; Frelon, Sandrine (Peer reviewed; Journal article, 2022)Reproductive effects of ionizing radiation in organisms have been observed under laboratory and field conditions. Such assessments often rely on associations between exposure and effects, and thus lacking a detailed ... -
AOP Report: Inhibition of Chitin Synthase 1 Leading to Increased Mortality in Arthropods
Schmid, Simon; Song, You; Tollefsen, Knut Erik (Peer reviewed; Journal article, 2021) -
Applying Adverse Outcome Pathways (AOPs) to support Integrated Approaches to Testing and Assessment (IATA)
Tollefsen, Knut Erik; Scholz, Stefan; Cronin, Mark T.; Edwards, Stephen W.; de Knecht, Joop; Crofton, Kevin; Garcia-Reyero, Natalia; Hartung, Thomas; Worth, Andrew; Patlewicz, Grace (Journal article; Peer reviewed, 2014)Chemical regulation is challenged by the large number of chemicals requiring assessment for potential human health and environmental impacts. Current approaches are too resource intensive in terms of time, money and animal ... -
Assessment of a novel device for onsite integrative large-volume solid phase extraction of water samples to enable a comprehensive chemical and effect-based analysis
Schulze, Tobias; Ahel, Marijan; Ahlheim, Jorg; Ait-Aissa, Selim; Brion, Francois; Di Paolo, Carolina; Froment, Jean Francois; Hidasi, Anita O; Hollender, Juliane; Hollert, Henner; Hu, Meng; Kloss, Anett; Koprivica, Sanja; Krauss, Martin; Muz, Melis; Oswald, Peter; Petre, Margit; Schollee, Jennifer E; Seiler, Thomas-Benjamin; Shao, Ying; Slobodnik, Jaroslav; Sonavane, Manoj; Suter, Marc J-F; Tollefsen, Knut Erik; Tousova, Zuzana; Walz, Karl-Heinz; Brack, Werner (Journal article; Peer reviewed, 2017)The implementation of targeted and nontargeted chemical screening analysis in combination with in vitro and organism-level bioassays is a prerequisite for a more holistic monitoring ofwater quality in the future. For ... -
Characterizing combined effects of antiestrogenic chemicals on vitellogenin production in rainbow trout (Oncorhynchus mykiss) hepatocytes
Hultman, Maria Thérése; Petersen, Karina; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2017)Fish are exposed to a complex mixture of endocrine disrupting compounds (EDC), some of which display antiestrogenic activity leading to suppression of estrogen receptor (ER)- mediated reproductive processes. Although the ... -
Characterizing cytotoxic and estrogenic activity of Arctic char tissue extracts in primary Arctic char hepatocytes
Petersen, Karina; Hultman, Maria Thérése; Bytingsvik, Jenny; Harju, Mikael; Evenset, Anita; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2017)Contaminants from various anthropogenic activities are detected in the Arctic due to long-range atmospheric transport, ocean currents, and living organisms such as migrating fish or seabirds. Although levels of persistent ... -
Deciphering the Combined Effects of Environmental Stressors on Gene Transcription: A Conceptual Approach
Song, You; Asselman, Jana; De Schamphelaere, Karel A. C.; Salbu, Brit; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2018)The use of classical mixture toxicity models to predict the combined effects of environmental stressors based on toxicogenomics (OMICS) data is still in its infancy. Although several studies have made attempts to implement ... -
Ecdysone Receptor Agonism Leading to Lethal Molting Disruption in Arthropods: Review and Adverse Outcome Pathway Development
Song, You; Villeneuve, Daniel L.; Toyota, Kenji; Iguchi, Taisen; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2017)Molting is critical for growth, development, reproduction and survival in arthropods. Complex neuroendocrine pathways are involved in the regulation of molting and may potentially become targets of environmental endocrine ... -
Ecdysteroid and juvenile hormone biosynthesis, receptors and their signaling in the freshwater microcrustacean Daphnia
Miyakawa, Hitoshi; Sato, Tomomi; Song, You; Tollefsen, Knut Erik; Iguchi, Taisen (Journal article; Peer reviewed, 2018)The two essential insect hormones, ecdysteroids and juvenile hormones, are possessed not only by insects, but also widely by arthropods, and regulate various developmental and physiological processes. In contrast to the ... -
Evaluation of the combined toxicity assessment and cumulative risk assessment of ecologically relevant mixtures of plant protection Products (PPPs) under Norwegian conditions
Tollefsen, Knut Erik; Bæk, Kine; Almeida, Ana; Haug, Linn Anette; Norli, Hans; Odenmarck, Sven; Stenrød, Marianne (NIVA-rapport;7050, Research report, 2016)This project evaluated whether the principles of combined toxicity assessment (CTA) and cumulative risk assessment (CRA) can be used to predict the toxicity of ecologically-relevant mixtures of plant protection products ... -
Gamma radiation induces dose-dependent oxidative stress and transcriptional alterations in the freshwater crustacean Daphnia magna
Gomes, Tania; Song, You; Brede, Dag Anders; Xie, Li; Gutzkow, Kristine Bjerve; Salbu, Brit; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2018)Among aquatic organisms, invertebrate species such as the freshwater crustacean Daphnia magna are believed to be sensitive to gamma radiation, although information on responses at the individual, biochemical and molecular ... -
Hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to gamma radiation and depleted uranium singly and in combination
Song, You; Salbu, Brit; Teien, Hans-Christian; Evensen, Øystein; Lind, Ole Christian; Rosseland, Bjørn Olav; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2016)Radionuclides are a special group of substances posing both radiological and chemical hazards to organisms. As a preliminary approach to understand the combined effects of radionuclides, exposure studies were designed using ... -
In silico site-directed mutagenesis of the Daphnia magna ecdysone receptor identifies critical amino acids for species-specific and inter-species differences in agonist binding
Evenseth, Linn M.; Kristiansen, Kurt; Song, You; Tollefsen, Knut Erik; Sylte, Ingebrigt (Journal article; Peer reviewed, 2019)Molting is an essential process in the life cycle of arthropods and is regulated by complex neuroendocrine pathways where activation of the ecdysone receptor (EcR) plays a major role. The EcR forms a non-covalent heterodimer ... -
Juvenile hormone synthesis and signaling disruption triggering male offspring induction and population decline in cladocerans (water flea): Review and adverse outcome pathway development
Toyota, Kenji; Watanabe, Haruna; Hirano, Masashi; Abe, Ryoko; Miyakawa, Hitoshi; Song, You; Sato, Tomomi; Miyagawa, Shinichi; Tollefsen, Knut Erik; Yamamoto, Hiroshi; Tatarazako, Norihisa; Iguchi, Taisen (Peer reviewed; Journal article, 2021)Juvenile hormone (JH) are a family of multifunctional hormones regulating larval development, molting, metamorphosis, reproduction, and phenotypic plasticity in arthropods. Based on its importance in arthropod life histories, ... -
Linking mode of action of the model respiratory and photosynthesis uncoupler 3,5-dichlorophenol to adverse outcomes in Lemna minor
Xie, Li; Gomes, Tania; Solhaug, Knut Asbjørn; Song, You; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2018)Standard chemical toxicity testing guidelines using aquatic plant Lemna minor have been developed by several international standardisation organisations. Although being highly useful for regulatory purposes by focusing on ... -
Miniaturization of a transthyretin binding assay using a fluorescent probe for high throughput screening of thyroid hormone disruption in environmental samples
Ouyang, Xiyu; Froment, Jean Francois; Leonards, Pim E.G.; Christensen, Guttorm; Tollefsen, Knut Erik; de Boer, Jacob; Thomas, Kevin V; Lamoree, Marja H. (Journal article; Peer reviewed, 2017)Thyroid hormone (TH) disrupting compounds are potentially important environmental contaminants due to their possible adverse neurological and developmental effects on both humans and wildlife. Currently, the most successful ... -
Mortality and transcriptional effects of inorganic mercury in the marine copepod Calanus finmarchicus
Tollefsen, Knut Erik; Song, You; Høgåsen, Tore; Øverjordet, Ida Beathe; Altin, Dag; Hansen, Bjørn Henrik (Journal article; Peer reviewed, 2017)Inorganic mercury (Hg) is highly toxic to organisms including crustaceans and displays multiple toxic modes of action (MoA). The main aim of this investigation was to assess the acute and sublethal toxicity mediated by ... -
No evidence of a protective or cumulative negative effect of UV-B on growth inhibition induced by gamma radiation in Scots pine (Pinus sylvestris) seedlings
Blagojevic, Dajana; Lee, YeonKyeong; Xie, Li; Brede, Dag A; Nybakken, Line; Lind, Ole Christian; Tollefsen, Knut Erik; Salbu, Brit; Solhaug, Knut Asbjørn; Olsen, Jorunn E (Peer reviewed; Journal article, 2019)Exposure to ambient UV-B radiation may prime protective responses towards various stressors in plants, though information about interactive effects of UV-B and gamma radiation is scarce. Here, we aimed to test whether UV-B ... -
Primary hepatocytes from Arctic char (Salvelinus alpinus) as a relevant Arctic in vitro model for screening contaminants and environmental extracts
Petersen, Karina; Hultman, Maria T; Tollefsen, Knut Erik (Journal article; Peer reviewed, 2017)Contaminants find their way to the Arctic through long-range atmospheric transport, transport via ocean currents, and through increased anthropogenic activity. Some of the typical pollutants reaching the Arctic (PAHs, PCBs) ...