Author
Petra Spirhanzlova
Other affiliations: University of Évry Val d'Essonne, Paris-Sorbonne University, National Museum of Natural History ...read more
Bio: Petra Spirhanzlova is an academic researcher from Centre national de la recherche scientifique. The author has contributed to research in topics: Xenopus & Thyroid. The author has an hindex of 9, co-authored 19 publications receiving 300 citations. Previous affiliations of Petra Spirhanzlova include University of Évry Val d'Essonne & Paris-Sorbonne University.
Papers
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TL;DR: A novel simplified protocol for effect-based monitoring of micropollutants in surface waters is presented and a comprehensive picture of the surface water status across Europe is drawn.
145 citations
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TL;DR: Exposure to a mixture of ubiquitous chemicals at concentrations found in human amniotic fluid affect thyroid hormone-dependent transcription, gene expression, brain development and behaviour in early embryogenesis, suggesting that ubiquitous chemical mixtures could be exerting adverse effects on foetal human brain development.
Abstract: Thyroid hormones are essential for normal brain development in vertebrates. In humans, abnormal maternal thyroid hormone levels during early pregnancy are associated with decreased offspring IQ and modified brain structure. As numerous environmental chemicals disrupt thyroid hormone signalling, we questioned whether exposure to ubiquitous chemicals affects thyroid hormone responses during early neurogenesis. We established a mixture of 15 common chemicals at concentrations reported in human amniotic fluid. An in vivo larval reporter (GFP) assay served to determine integrated thyroid hormone transcriptional responses. Dose-dependent effects of short-term (72 h) exposure to single chemicals and the mixture were found. qPCR on dissected brains showed significant changes in thyroid hormone-related genes including receptors, deiodinases and neural differentiation markers. Further, exposure to mixture also modified neural proliferation as well as neuron and oligodendrocyte size. Finally, exposed tadpoles showed behavioural responses with dose-dependent reductions in mobility. In conclusion, exposure to a mixture of ubiquitous chemicals at concentrations found in human amniotic fluid affect thyroid hormone-dependent transcription, gene expression, brain development and behaviour in early embryogenesis. As thyroid hormone signalling is strongly conserved across vertebrates the results suggest that ubiquitous chemical mixtures could be exerting adverse effects on foetal human brain development.
48 citations
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TL;DR: The spg1-gfp medaka model provides a sensitive, specific, and physiologically pertinent biosensor system for analyzing environmental androgen activity.
Abstract: Widespread environmental antiandrogen contamination has been associated with negative impacts on biodiversity and human health. In particular, many pesticides are antiandrogenic, creating a need for robust and sensitive environmental monitoring. Our aim was to develop a sensitive and specific transgenic medaka (Oryzias latipes) model bearing an androgen responsive fluorescent reporter construct for whole organism-based environmental screening of pro- and antiandrogens. We analyzed the 5′ regions of the androgen responsive three-spined stickleback (Gasterosteus aculeatus) spiggin genes in silico, revealing conserved blocks of sequence harboring androgen response elements. Identified putative promoters were cloned upstream of GFP. Germinal transgenesis with spg1-gfp led to stable medaka lines. GFP induction was exclusive to the kidney, the site of spiggin protein production in sticklebacks. Significant GFP expression was induced by three or four-day androgen treatment of newly hatched fry, but not by estrog...
33 citations
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TL;DR: Optimized reference gene pair combinations are reported for studying development, brains at later stages (metamorphosis and adult), and thyroid signalling for Xenopus laevis.
Abstract: Reference genes are essential for gene expression analysis when using real-time quantitative PCR (RT-qPCR). Xenopus laevis is a popular amphibian model for studying vertebrate embryogenesis and development. Further, X. laevis is ideal for studying thyroid signaling due to its thyroid dependent metamorphosis, a stage comparable to birth in humans. When using PCR based studies, a primary concern is the choice of reference genes. Commonly used references are eef1a1, odc1, rpl8, and actnB, although there is a lack of ad hoc reference genes for X. laevis. Here, we used previously published RNA-seq data on different X. laevis stages and identified the top 14 candidate genes with respect to their expression levels as a function of developmental stage and degree of variation. We further evaluated the stability of these and other candidate genes using RT-qPCR on various stages including the unfertilised eggs, whole embryos during early development and brains during late development. We used four different statistical software packages: deltaCT, geNorm, NormFinder and BestKeeper. We report optimized reference gene pair combinations for studying development (early whole embryos), brains at later stages (metamorphosis and adult), and thyroid signalling. These reference gene pairs are suitable for studying different aspects of X. laevis development and organogenesis.
33 citations
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TL;DR: Development and benchmarking of a set of novel fluorescence-based procedures to assess the occurrence of oxidative stress in zebrafish larvae by measuring the antioxidant glutathione (GSH) and general ROS showed that the orientation of the larvae in the well can influence fluorescence data evaluation.
29 citations
Cited by
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TL;DR: Most frequent substances as well as those found at highest concentrations in different seasons and regions, together with available risk assessment data, may be useful to identify possible future PS candidates.
545 citations
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TL;DR: This work highlights analytical and bioanalytical approaches to isolating, characterizing, and tracking groups of chemicals of concern in complex matrices and proposes techniques that combine chemical analysis and bioassays to facilitate the identification of mixtures of chemicals that pose a combined risk.
Abstract: Chemicals have improved our quality of life, but the resulting environmental pollution has the potential to cause detrimental effects on humans and the environment. People and biota are chronically exposed to thousands of chemicals from various environmental sources through multiple pathways. Environmental chemists and toxicologists have moved beyond detecting and quantifying single chemicals to characterizing complex mixtures of chemicals in indoor and outdoor environments and biological matrices. We highlight analytical and bioanalytical approaches to isolating, characterizing, and tracking groups of chemicals of concern in complex matrices. Techniques that combine chemical analysis and bioassays have the potential to facilitate the identification of mixtures of chemicals that pose a combined risk.
305 citations
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Helmholtz Centre for Environmental Research - UFZ1, United States Environmental Protection Agency2, RWTH Aachen University3, Environment Canada4, Masaryk University5, Swiss Federal Institute of Aquatic Science and Technology6, Analysis Group7, VU University Amsterdam8, Leibniz Association9, Norwegian Institute for Air Research10, State University of Campinas11
TL;DR: Current experience with the EDA approach and the tools required are summarized, and practical advice on their application is provided, highlighting the need for proper problem formulation and giving general advice for study design.
276 citations
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Helmholtz Centre for Environmental Research - UFZ1, University of Liverpool2, University of Gothenburg3, Spanish National Research Council4, RWTH Aachen University5, University of Birmingham6, State University of Campinas7, Wageningen University and Research Centre8, Masaryk University9, Swiss Federal Institute of Aquatic Science and Technology10, Brunel University London11, Leibniz Association12, University of Bern13, University of Novi Sad14, Norwegian Institute for Water Research15, Nanjing University16
TL;DR: The vision of the international, EU-funded project SOLUTIONS is described, where three routes are explored to link the occurrence of chemical mixtures at specific sites to the assessment of adverse biological combination effects, and comprehensive arrays of effect-based tools and trait-based field observations are explored.
249 citations
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TL;DR: This Guidance describes how to perform hazard identification for endocrine‐disrupting properties by following the scientific criteria which are outlined in Commission Delegated Regulation (EU) 2017/2100 and Commission Regulation 2018/605 for biocidal products and plant protection products, respectively.
Abstract: This Guidance describes how to perform hazard identification for endocrine-disrupting properties by following the scientific criteria which are outlined in Commission Delegated Regulation (EU) 2017/2100 and Commission Regulation (EU) 2018/605 for biocidal products and plant protection products, respectively.
239 citations