3,865 research outputs found

    Introduction: The ecological relevance of chemically induced endocrine disruption in wildlife

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    This article is part of the monograph “The Ecological Relevance of Chemically Induced Endocrine Disruption in Wildlife.

    COMPRENDO: Focus and approach

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    Tens of thousands of man-made chemicals are in regular use and discharged into the environment. Many of them are known to interfere with the hormonal systems in humans and wildlife. Given the complexity of endocrine systems, there are many ways in which endocrine-disrupting chemicals (EDCs) can affect the body’s signaling system, and this makes unraveling the mechanisms of action of these chemicals difficult. A major concern is that some of these EDCs appear to be biologically active at extremely low concentrations. There is growing evidence to indicate that the guiding principle of traditional toxicology that “the dose makes the poison” may not always be the case because some EDCs do not induce the classical dose–response relationships. The European Union project COMPRENDO (Comparative Research on Endocrine Disrupters—Phylogenetic Approach and Common Principles focussing on Androgenic/Antiandrogenic Compounds) therefore aims to develop an understanding of potential health problems posed by androgenic and antiandrogenic compounds (AACs) to wildlife and humans by focusing on the commonalities and differences in responses to AACs across the animal kingdom (from invertebrates to vertebrates)

    Early homeostatic disturbances of human growth and maturation by endocrine disrupters

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    peer reviewedWe attempt to delineate and integrate aspects of growth and development that could be affected by endocrine disrupters [endocrine-disrupting compounds (EDC)], an increasing public health concern. RECENT FINDINGS: Epidemiological and experimental data substantiate that fetal and early postnatal life are critical periods of exposure to endocrine disrupters, with possible transgenerational effects. The EDC effects include several disorders of the reproductive system throughout life (abnormalities of sexual differentiation, infertility or subfertility and some neoplasia) and disorders of energy balance (obesity and metabolic syndrome). The mechanisms are consistent with the concept of 'developmental origin of adult disease'. They could involve cross-talk between the factors controlling reproduction and those controlling energy balance, both in the hypothalamus and peripherally. SUMMARY: Due to ubiquity of endocrine disrupters and lifelong stakes of early exposure, individual families should be provided by pediatricians with recommendations following the precautionary principle, that is prevention or attenuation of conditions possibly detrimental to health before the evidence of such adverse effects is complete and undisputable

    Effect of age and cytoskeletal elements on the indentation-dependent mechanical properties of chondrocytes.

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    Articular cartilage chondrocytes are responsible for the synthesis, maintenance, and turnover of the extracellular matrix, metabolic processes that contribute to the mechanical properties of these cells. Here, we systematically evaluated the effect of age and cytoskeletal disruptors on the mechanical properties of chondrocytes as a function of deformation. We quantified the indentation-dependent mechanical properties of chondrocytes isolated from neonatal (1-day), adult (5-year) and geriatric (12-year) bovine knees using atomic force microscopy (AFM). We also measured the contribution of the actin and intermediate filaments to the indentation-dependent mechanical properties of chondrocytes. By integrating AFM with confocal fluorescent microscopy, we monitored cytoskeletal and biomechanical deformation in transgenic cells (GFP-vimentin and mCherry-actin) under compression. We found that the elastic modulus of chondrocytes in all age groups decreased with increased indentation (15-2000 nm). The elastic modulus of adult chondrocytes was significantly greater than neonatal cells at indentations greater than 500 nm. Viscoelastic moduli (instantaneous and equilibrium) were comparable in all age groups examined; however, the intrinsic viscosity was lower in geriatric chondrocytes than neonatal. Disrupting the actin or the intermediate filament structures altered the mechanical properties of chondrocytes by decreasing the elastic modulus and viscoelastic properties, resulting in a dramatic loss of indentation-dependent response with treatment. Actin and vimentin cytoskeletal structures were monitored using confocal fluorescent microscopy in transgenic cells treated with disruptors, and both treatments had a profound disruptive effect on the actin filaments. Here we show that disrupting the structure of intermediate filaments indirectly altered the configuration of the actin cytoskeleton. These findings underscore the importance of the cytoskeletal elements in the overall mechanical response of chondrocytes, indicating that intermediate filament integrity is key to the non-linear elastic properties of chondrocytes. This study improves our understanding of the mechanical properties of articular cartilage at the single cell level

    Endocrine disruptors in bottled mineral water : total estrogenic burden and migration from plastic bottles

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    Background, aim, and scope Food consumption is an important route of human exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by exposure modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. Materials, methods, and results In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17beta-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Discussion and conclusions Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics. Keywords Endocrine disrupting chemicals - Estradiol equivalents - Human exposure - In vitro effects - In vivo effects - Mineral water - Plastic bottles - Plastic packaging - Polyethylene terephthalate - Potamopyrgus antipodarum - Yeast estrogen screen - Xenoestrogen

    The fate of steroid estrogens: Partitioning during wastewater treatment and onto river sediments

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Springer Science+Business Media B.V.The partitioning of steroid estrogens in wastewater treatment and receiving waters is likely to influence their discharge to, and persistence in, the environment. This study investigated the partitioning behaviour of steroid estrogens in both laboratory and field studies. Partitioning onto activated sludge from laboratory-scale Husmann units was rapid with equilibrium achieved after 1 h. Sorption isotherms and Kd values decreased in the order 17α-ethinyl estradiol > 17α-estradiol > estrone > estriol without a sorption limit being achieved (1/n >1). Samples from a wastewater treatment works indicated no accumulation of steroid estrogens in solids from primary or secondary biological treatment, however, a range of steroid estrogens were identified in sediment samples from the River Thames. This would indicate that partitioning in the environment may play a role in the long-term fate of estrogens, with an indication that they will be recalcitrant in anaerobic conditions.EPSR

    Key scientific issues relevant to the identification and characterisation of endocrine disrupting substances - Report of the Endocrine Disrupters Expert Advisory Group

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    The European Commission, under Directorate-General for Environment (DG ENV) as file leader of the Community Strategy on Endocrine Disrupters, In 2010, DG ENV created an ad hoc group of Commission Services and Member States on the EU Community Strategy on Endocrine Disrupters. The ad hoc group created the Endocrine Disrupters Expert Advisory Group (ED EAG) in November 2011 to provide scientific advice on the development of criteria for identification of EDs. The European Commission's Joint Research Centre was tasked with running the expert sub-group, consisting of around 40 experts nominated by Member State regulatory authorities, relevant industry associations and non-governmental consumer/environmental protection organisations. This report captures the experts' opinions on key scientific issues relevant to the identification and characterisation of endocrine disrupting substances (EDs). It provides one input to the Commission’s decisions on the establishment of horizontal criteria for the identification of EDs to be applied as appropriate across all relevant pieces of legislation concerning the control and risk management of chemicals substances (including pesticides, biocides, pharmaceuticals, industrial chemicals, controls on water quality, occupational exposure, etc).JRC.I.5-Systems Toxicolog
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