The Experts below are selected from a list of 6564 Experts worldwide ranked by ideXlab platform
Judit E G Smits - One of the best experts on this subject based on the ideXlab platform.
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oxidative stress biomarkers indicate sublethal health effects in a sentinel small mammal species the deer mouse peromyscus maniculatus on reclaimed oil sands areas
Ecological Indicators, 2016Co-Authors: Jaime Rodriguezestival, Esther Garciade Blas, Judit E G SmitsAbstract:Abstract Oxidative stress biomarkers can provide highly relevant insights into the physiological state of an organism. We compared endogenous oxidative stress biomarkers (lipid peroxidation and glutathione redox status) in the liver and testes as well as the hepatic antioxidant vitamins A and E in deer mice ( Peromyscus maniculatus ) collected from a reclaimed mine site on the Athabasca Oil Sands Region (northern Alberta, Canada), with those from a non-industrial reference site within the same natural macroregion. Both glutathione redox and vitamin A status in the liver as well as glutathione redox status in the testes were disrupted in mice from the reclaimed site, indicating oxidative stress in these organs. Increased oxidative stress in the liver was associated with greater exposure to Co, Se, and Tl and contributed to poorer body condition and lowered testis size in animals from the reclaimed site (data from companion study). These results confirm health effects and biological costs in this native, sentinel small mammal from exposure to pollutants at the reclaimed mine site. This work provides compelling information and insight into the value of oxidative stress biomarkers as physiological tools that can indicate the health status and fitness of local wild animals. In particular, this approach can be used by Risk Assessors and other stakeholders from the oil sands region in future environmental Risk assessments to improve wildlife management and conservation practices.
Patricia K Schmieder - One of the best experts on this subject based on the ideXlab platform.
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adverse outcome pathways a conceptual framework to support ecotoxicology research and Risk assessment
Environmental Toxicology and Chemistry, 2010Co-Authors: Gerald T Ankley, Richard S Bennett, Russell J Erickson, Dale J Hoff, Michael W Hornung, Rodney D Johnson, David R Mount, John W Nichols, Christine L Russom, Patricia K SchmiederAbstract:Ecological Risk Assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that could help in meeting these challenges. However, to use mechanistic data to support chemical assessments, there is a need for effective translation of this information into endpoints meaningful to ecological Risk—effects on survival, development, and reproduction in individual organisms and, by extension, impacts on populations. Here we discuss a framework designed for this purpose, the adverse outcome pathway (AOP). An AOP is a conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome at a biological level of organization relevant to Risk assessment. The practical utility of AOPs for ecological Risk assessment of chemicals is illustrated using five case examples. The examples demonstrate how the AOP concept can focus toxicity testing in terms of species and endpoint selection, enhance across-chemical extrapolation, and support prediction of mixture effects. The examples also show how AOPs facilitate use of molecular or biochemical endpoints (sometimes referred to as biomarkers) for forecasting chemical impacts on individuals and populations. In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical Risk assessments and advocate for the incorporation of this approach into a broader systems biology framework. Environ. Toxicol. Chem. 2010;29:730–741. © 2009 SETAC
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adverse outcome pathways a conceptual framework to support ecotoxicology research and Risk assessment
Environmental Toxicology and Chemistry, 2010Co-Authors: Gerald T Ankley, Richard S Bennett, Russell J Erickson, Dale J Hoff, Michael W Hornung, Rodney D Johnson, David R Mount, John W Nichols, Christine L Russom, Patricia K SchmiederAbstract:Ecological Risk Assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that could help in meeting these challenges. However, to use mechanistic data to support chemical assessments, there is a need for effective translation of this information into endpoints meaningful to ecological Risk-effects on survival, development, and reproduction in individual organisms and, by extension, impacts on populations. Here we discuss a framework designed for this purpose, the adverse outcome pathway (AOP). An AOP is a conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome at a biological level of organization relevant to Risk assessment. The practical utility of AOPs for ecological Risk assessment of chemicals is illustrated using five case examples. The examples demonstrate how the AOP concept can focus toxicity testing in terms of species and endpoint selection, enhance across-chemical extrapolation, and support prediction of mixture effects. The examples also show how AOPs facilitate use of molecular or biochemical endpoints (sometimes referred to as biomarkers) for forecasting chemical impacts on individuals and populations. In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical Risk assessments and advocate for the incorporation of this approach into a broader systems biology framework.
Jaime Rodriguezestival - One of the best experts on this subject based on the ideXlab platform.
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oxidative stress biomarkers indicate sublethal health effects in a sentinel small mammal species the deer mouse peromyscus maniculatus on reclaimed oil sands areas
Ecological Indicators, 2016Co-Authors: Jaime Rodriguezestival, Esther Garciade Blas, Judit E G SmitsAbstract:Abstract Oxidative stress biomarkers can provide highly relevant insights into the physiological state of an organism. We compared endogenous oxidative stress biomarkers (lipid peroxidation and glutathione redox status) in the liver and testes as well as the hepatic antioxidant vitamins A and E in deer mice ( Peromyscus maniculatus ) collected from a reclaimed mine site on the Athabasca Oil Sands Region (northern Alberta, Canada), with those from a non-industrial reference site within the same natural macroregion. Both glutathione redox and vitamin A status in the liver as well as glutathione redox status in the testes were disrupted in mice from the reclaimed site, indicating oxidative stress in these organs. Increased oxidative stress in the liver was associated with greater exposure to Co, Se, and Tl and contributed to poorer body condition and lowered testis size in animals from the reclaimed site (data from companion study). These results confirm health effects and biological costs in this native, sentinel small mammal from exposure to pollutants at the reclaimed mine site. This work provides compelling information and insight into the value of oxidative stress biomarkers as physiological tools that can indicate the health status and fitness of local wild animals. In particular, this approach can be used by Risk Assessors and other stakeholders from the oil sands region in future environmental Risk assessments to improve wildlife management and conservation practices.
Gerald T Ankley - One of the best experts on this subject based on the ideXlab platform.
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adverse outcome pathways a conceptual framework to support ecotoxicology research and Risk assessment
Environmental Toxicology and Chemistry, 2010Co-Authors: Gerald T Ankley, Richard S Bennett, Russell J Erickson, Dale J Hoff, Michael W Hornung, Rodney D Johnson, David R Mount, John W Nichols, Christine L Russom, Patricia K SchmiederAbstract:Ecological Risk Assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that could help in meeting these challenges. However, to use mechanistic data to support chemical assessments, there is a need for effective translation of this information into endpoints meaningful to ecological Risk—effects on survival, development, and reproduction in individual organisms and, by extension, impacts on populations. Here we discuss a framework designed for this purpose, the adverse outcome pathway (AOP). An AOP is a conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome at a biological level of organization relevant to Risk assessment. The practical utility of AOPs for ecological Risk assessment of chemicals is illustrated using five case examples. The examples demonstrate how the AOP concept can focus toxicity testing in terms of species and endpoint selection, enhance across-chemical extrapolation, and support prediction of mixture effects. The examples also show how AOPs facilitate use of molecular or biochemical endpoints (sometimes referred to as biomarkers) for forecasting chemical impacts on individuals and populations. In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical Risk assessments and advocate for the incorporation of this approach into a broader systems biology framework. Environ. Toxicol. Chem. 2010;29:730–741. © 2009 SETAC
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adverse outcome pathways a conceptual framework to support ecotoxicology research and Risk assessment
Environmental Toxicology and Chemistry, 2010Co-Authors: Gerald T Ankley, Richard S Bennett, Russell J Erickson, Dale J Hoff, Michael W Hornung, Rodney D Johnson, David R Mount, John W Nichols, Christine L Russom, Patricia K SchmiederAbstract:Ecological Risk Assessors face increasing demands to assess more chemicals, with greater speed and accuracy, and to do so using fewer resources and experimental animals. New approaches in biological and computational sciences may be able to generate mechanistic information that could help in meeting these challenges. However, to use mechanistic data to support chemical assessments, there is a need for effective translation of this information into endpoints meaningful to ecological Risk-effects on survival, development, and reproduction in individual organisms and, by extension, impacts on populations. Here we discuss a framework designed for this purpose, the adverse outcome pathway (AOP). An AOP is a conceptual construct that portrays existing knowledge concerning the linkage between a direct molecular initiating event and an adverse outcome at a biological level of organization relevant to Risk assessment. The practical utility of AOPs for ecological Risk assessment of chemicals is illustrated using five case examples. The examples demonstrate how the AOP concept can focus toxicity testing in terms of species and endpoint selection, enhance across-chemical extrapolation, and support prediction of mixture effects. The examples also show how AOPs facilitate use of molecular or biochemical endpoints (sometimes referred to as biomarkers) for forecasting chemical impacts on individuals and populations. In the concluding sections of the paper, we discuss how AOPs can help to guide research that supports chemical Risk assessments and advocate for the incorporation of this approach into a broader systems biology framework.
M E Meek - One of the best experts on this subject based on the ideXlab platform.
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Case study illustrating the WHO IPCS guidance on characterization and application of physiologically based pharmacokinetic models in Risk assessment
Regulatory toxicology and pharmacology : RTP, 2013Co-Authors: M E Meek, Hugh A. Barton, J.g.m. Bessems, John C. Lipscomb, Kannan KrishnanAbstract:The World Health Organization (WHO) International Programme on Chemical Safety (IPCS) Guidance on Characterization and Application of Physiologically Based Pharmacokinetic Models in Risk Assessment (IPCS, 2010) describes key principles for Risk Assessors and model developers. In the WHO Guidance, a template for model documentation was developed and a case study included. Here the WHO Guidance, including the template, is summarized and an additional case study is presented to illustrate its application, based upon an existing Risk assessment for 2-butoxyethanol (CAS NO. 111-76-2). The goal of the WHO Guidance and the current paper is to increase regulatory acceptance of complex biologically descriptive pharmacokinetic (or toxicokinetic) models, such as PBPK models, by facilitating communication and successful interaction between modelers and Risk Assessors.
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Risk assessment of combined exposure to multiple chemicals a who ipcs framework
Regulatory Toxicology and Pharmacology, 2011Co-Authors: M E Meek, Alan R Boobis, Kevin M Crofton, G Heinemeyer, M Van Raaij, Carolyn VickersAbstract:This paper describes a framework for the Risk assessment of combined exposure to multiple chemicals based on and developed subsequent to the World Health Organization/International Programme on Chemical Safety Workshop on Aggregate/Cumulative Risk Assessment (Combined Exposures to Multiple Chemicals) held in 2007. The framework is designed to aid Risk Assessors in identifying priorities for Riskmanagement for a wide range of applications where co-exposures to multiple chemicals are expected. It is based on a hierarchical (phased) approach that involves integrated and iterative consideration of exposureand hazard at all phases, with each tier being more refined (i.e., less cautious and more certain) than the previous one, but more labor and data intensive. It includes reference to predictive and probabilistic methodology in various tiers in addition to tiered consideration of uncertainty. The paper also annexes two case studies that have been developed to test and refine the framework.
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guidelines for application of chemical specific adjustment factors in dose concentration response assessment
Toxicology, 2002Co-Authors: M E Meek, A Renwick, E Ohanian, M Dourson, B Lake, B D NaumannAbstract:This manuscript addresses guidance in the use of kinetic and dynamic data to inform quantitatively extrapolations for interspecies differences and human variability in dose-response assessment developed in a project of the International Programme on Chemical Safety (IPCS) initiative on Harmonisation of Approaches to the Assessment of Risk from Exposure to Chemicals. The guidance has been developed and refined through a series of planning and technical meetings and larger workshops of a broad range of participants from academia, government agencies and the private sector. The guidance for adequacy of data for replacement of common defaults for interspecies differences and human variability is presented in the context of several generic categories including: determination of the active chemical species, choice of the appropriate metric (kinetic components) or endpoint (dynamic components) and nature of experimental data, the latter which includes reference to the relevance of population, route and dose and the adequacy of the number of subjects/samples. The principal objective of this guidance developed primarily as a resource for Risk Assessors, is to foster better understanding of the components of and criteria for adequacy of chemical-specific data to quantitate interspecies differences and human variability in kinetics and dynamics. It is anticipated that this guidance will also encourage the development of appropriate data and facilitate their incorporation in a consistent fashion in dose-response assessment for regulatory purposes (IPCS, 2001).
