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Amsterdam-Zuidoost, Netherlands

Bovee T.F.H.,Wageningen University | Helsdingen R.J.R.,Wageningen University | Hamers A.R.M.,Wageningen University | Brouwer B.A.,BioDetection Systems BV BDS | Nielen M.W.F.,Wageningen University
Analytical and Bioanalytical Chemistry | Year: 2011

Sensitive and robust bioassays for glucocorticoids are very useful for the pharmaceutical industry, environmental scientists and veterinary control. Here, a recombinant yeast cell was constructed that expresses the human glucocorticoid receptor alpha and a green fluorescent reporter protein in response to glucocorticoids. Both the receptor construct and the reporter construct were stably integrated into the yeast genome. The correct and specific functioning of this yeast glucocorticoid bioassay was studied by exposures to cortisol and other related compounds and critically compared to a GR-CALUX bioassay based on a human bone cell. Although less sensitive, the new yeast glucocorticoid bioassay showed sensitivity towards all (gluco)corticoids tested, with the following order in relative potencies: budesonide >> corticosterone > dexamethasone > cortisol = betamethasone > prednisolone > aldosterone. Hormone representatives for other hormone nuclear receptors, like 17β-estradiol for the oestrogen receptor, 5α-dihydrotestosterone for the androgen receptor and progesterone for the progesterone receptor, showed no clear agonistic responses, whilst some polychlorinated biphenyls were clearly able to interfere with the GR activity. © 2011 The Author(s). Source

Moriwaki H.,Shinshu University | Sakiyama T.,Japan Institute for Environmental Sciences | Yamoto Y.,Kansai University | Weber R.,Ulmenstarasse 3 | And 3 more authors.
Bunseki Kagaku | Year: 2013

Products of a thermal reaction of chlorpyrifos were analyzed by LC/MS and GC/MS. As a result, it was found that chlorpyrifos undergoes an elimination reaction of phosphate by a thermal reaction. Furthermore, it is indicated that the structural analogue of 2,3,7,8-TCDD arises by a thermal reaction of chlorpyrifos. In addition, the toxicity of the products of the thermal reaction of chlorpyrifos, evaluated by DR-CALUX®, was higher than that of chlorpyrifos itself. © 2013 The Japan Society for Analytical Chemistry. Source

Simon E.,BioDetection Systems BV BDS | Simon E.,Ecole Polytechnique Federale de Lausanne | Lamoree M.H.,VU University Amsterdam | Hamers T.,VU University Amsterdam | de Boer J.,VU University Amsterdam
TrAC - Trends in Analytical Chemistry | Year: 2015

Effect-directed analysis (EDA), the combined use of bioassay-guided fractionation and analytical chemical techniques, enables detection of chemicals by their effects, facilitates identification of non-target compounds and transformation products with a certain toxic mode of action and assists in revealing mixture effects. To date, EDA has been restricted mainly to abiotic environmental compartments (e.g., sediment, water, and household dust) and has scarcely been applied to biotic compartments (e.g., tissue or homogenate of organisms, blood, and urine) due to difficulties in sample preparation of biological materials prior to bio/chemical analyses. EDA of biological samples is particularly suitable for: (i) identification of non-target compounds causing biological threat, while considering their bioavailability, bioaccumulation, and possible metabolization; or, (ii) indicating toxicity when the analyzed target compounds can only partly explain the measured effects. This overview discusses the importance, the challenges and the recent improvements in EDA with a focus on biota samples. © 2015 Elsevier B.V. Source

Bovee T.F.H.,Wageningen University | Heskamp H.H.,Wageningen University | Helsdingen R.J.R.,Wageningen University | Hamers A.R.M.,Wageningen University | And 2 more authors.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2013

Use of hormones for fattening purposes is forbidden in the animal production in Europe (European Commission. 1996. Council Directive EC/96/22 (replacement of 88/146/EC). Off J Eur Commun. L125:3-9; European Commission. 1996. Council Directive EC/96/23. Off J Eur Commun. L125:10-32). Moreover, Regulation (EC) 178/2002 (European Commission. 2002. Regulation EC No 178/2002. Off J Eur Commun. L31:1-24) and Regulation (EC) 882/2004 (European Commission. 2004. Regulation EC No 882/2004. Off J Eur Commun. L165:1-135) oblige the member states to identify emerging risks and use validated and accredited methods for control analysis. Only combinations of bioassay activity screening with chemical identification are suited to uphold all laws. No such combination is described for the detection of (gluco)corticoids. In the present study, the GR-CALUX bioassay was validated as a qualitative screening method for the determination of glucocorticoid activity in feed. This validation was performed according to EC Decision 2002/657/EC (European Commission. 2002. Commission Decision 2002/657/EC from Directive 96/23. Off J Eur Commun. L221:8-36). Twenty-two representative blank feed samples were selected and spiked with 50 ng g-1 of dexamethasone, 100 ng g-1 of betamethasone or 500 ng g-1 of triamcinolone. All blank and spiked feed samples fulfilled the CCα and CCβ criteria; the method was specific and robust and glucocorticoids in feed were stable for at least 88 days. © 2013 Copyright Taylor and Francis Group, LLC. Source

Rostkowski P.,University of Sussex | Horwood J.,University of Sussex | Shears J.A.,University of Exeter | Lange A.,University of Exeter | And 4 more authors.
Environmental Science and Technology | Year: 2011

The widespread occurrence of feminized male fish downstream of some UK Wastewater Treatment Works (WwTWs) has been associated with exposure to estrogenic and potentially antiandrogenic (AA) contaminants in the effluents. In this study, profiling of AA contaminants in WwTW effluents and fish was conducted using HPLC in combination with in vitro androgen receptor transcription screens. Analysis of extracts of wastewater effluents revealed complex profiles of AA activity comprising 21-53 HPLC fractions. Structures of bioavailable antiandrogens were identified by exposing rainbow trout to a WwTW effluent and profiling the bile for AA activity using yeast (anti-YAS) and mammalian-based (AR-CALUX) androgen receptor transcription screens. The predominant fractions with AA activity in both androgen receptor screens contained the germicides chlorophene and triclosan, and together these contaminants accounted for 51% of the total anti-YAS activity in the fish bile. Other AA compounds identified in bile included chloroxylenol, dichlorophene, resin acids, napthols, oxybenzone, 4-nonylphenol, and bisphenol A. Pure standards of these compounds were active in the androgen receptor screens at potencies relative to flutamide of between 0.1 and 13.0. Thus, we have identified, for the first time, a diverse range of AA chemicals in WwTWs that are bioavailable to fish and which need to be assessed for their risk to the reproductive health of these organisms and other aquatic biota. © 2011 American Chemical Society. Source

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