References of "Maghuin-Rogister, Guy"
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See detailEvaluation of the DR-CALUX screening of food and feed, according to regulation levels including DL-PCB
Scippo, Marie-Louise ULg; Rybertt, Soledad; Focant, Jean-François ULg et al

in Organohalogen Compounds (2005), 67

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See detailComprehensive two-dimensional gas chromatography with isotope dilution time-of-flight mass spectrometry for the measurement of dioxins and polychlorinated biphenyls in foodstuffs - Comparison with other methods
Focant, Jean-François ULg; Eppe, Gauthier ULg; Scippo, Marie-Louise ULg et al

in Journal of Chromatography. A (2005), 1086(1-2), 45-60

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo ... [more ▼]

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), ten 2,3,7,8-substituted polychlorinated dibenzofurans (PCDFs), four non-ortho-polychlorinated biphenyls (PCBs), eight mono-ortho-PCBs, and six indicator PCBs (Aroclor 1260) in foodstuff samples. A 40 m RTX-500 (0.18 mm I.D., 0.10 mu m df) was used as the first dimension (D-1) and a 1.5 nn BPX-50 (0.10 mm I.D., 0.10 mu m df) as the second dimension (2 D). The GC x GC chromatographic separation was completed in 45 min. Quantification was performed using C-13-label isotope dilution (11)). Isotope ratios of the selected quantification ions were checked against theoretical values prior to peak assignment and quantification. The dynamic working range spanned three orders of magnitude. The lowest detectable amount of 2,3,7,8-TCDD was 0.2 pg. Fish, pork, and milk samples were considered. On a congener basis, the GC x GC-ID-TOF-MS method was compared to the reference GC-ID high resolution mass spectrometry (HRMS) method and to the alternative GC-ID tandem-in-time quadrupole ion storage mass spectrometry (QIST-MS/MS). PCB levels ranged from low picogram (pg) to low nanogram (ng) per gram of sample and data compared very well between the different methods. For all matrices, PCDD/Fs were at a low pg level (0.05-3 pg) on a fresh weight basis. Although congener profiles were accurately described, RSDs of GC x GC-ID-TOF-MS and GC-QIST-MS/MS were much higher than for GC-ID-HRMS, especially for low level pork and milk. On a toxic equivalent (TEQ) basis, all methods, including the dioxin-responsive chemically activated luciferase gene expression (DR-CALUX) assay, produced similar responses. A cost comparison is also presented. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailEnhancement of steroid receptor-mediated transcription for the development of highly responsive bioassays
Willemsen, Philippe; Scippo, Marie-Louise ULg; Maghuin-Rogister, Guy ULg et al

in Analytical and Bioanalytical Chemistry (2005), 382(4), 894-905

We have previously generated several transformed human mammary cell lines for the detection of steroid receptor-mediated activities and used these cell lines to detect and characterize steroid hormone ... [more ▼]

We have previously generated several transformed human mammary cell lines for the detection of steroid receptor-mediated activities and used these cell lines to detect and characterize steroid hormone (ant)agonistic compounds. In this report, we describe the specific optimization procedures used to enhance receptor-mediated transcription through the human glucocorticoid, progesterone and androgen receptors, respectively. Sodium arsenite-induced chemical stress leads to a substantial and specific increase in the glucocorticold receptor-mediated transcription, resulting in maximal stimulations of more than 2000-fold by the agonist dexamethasone. Similarly, a combined treatment with forskolin (an activator of adenylate cyclase) and trichostatin A (an inhibitor of histone deacetylases) leads to a synergistic enhancement of progesterone or androgen stimulation, resulting in a maximal induction of more than 200-fold or about 100-fold, respectively. The enhanced responses to specific steroids are mediated by the corresponding nuclear receptor. We show that by using these enhanced transcriptional stimulation protocols, it is possible to detect lower amounts of steroid hormones without substantially affecting the relative biological activities of various agonists. Finally, the application of these enhanced reporter cell assays to real biological samples from meat-producing animals is evaluated, and some validation parameters are presented. [less ▲]

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See detailPerformances and limitations of the HRMS method for dioxins, furans and dioxin-like PCBs analysis in animal feedingstuffs Part II: Does it comply with the European pro-active approach?
Eppe, Gauthier ULg; Maghuin-Rogister, Guy ULg; De Pauw, Edwin ULg

in Analytica Chimica Acta (2004), 519(2), 243-253

Based on the results obtained from the inter-laboratory study in Part 1, different approaches for detection and quantification limits are evaluated and discussed. An overview of the most commonly used ... [more ▼]

Based on the results obtained from the inter-laboratory study in Part 1, different approaches for detection and quantification limits are evaluated and discussed. An overview of the most commonly used concepts and terminologies in analytical chemistry is presented with the aim of establishing a link between them. Whatever the method used by laboratories for detection limit assessment, the median LOD value reported for the less chlorinated PCDD/Fs (i.e. 0.02 ng/kg) is in good agreement with the values recalculated using the inter-laboratory data. For LOQ the Eurachem approach based on a pre-established percentage of repeatability RSD appears to be. suitable. The study shows that a pre-established RSDr of 20% is recommended in order to achieve an acceptable LOQ of 0.05 ng/kg per congener. The 20% value seems to be sufficiently low to act tolerable RSD close to maximum limits. Furthermore, the repeatability and the reproducibility standard deviation against parts-per-trillion congener levels has been modeled by inverse first order functions. This congener precision model provides an interesting tool to subsequently assess the performances of the method in TEQ close to regulatory limits. Finally, the paper discusses two different ways of reporting and interpreting the results to assess compliance against statutory limits. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailUse of reporter cell lines for detection of endocrine-disrupter activity
Willemsen, Philippe; Scippo, Marie-Louise ULg; Kausel, G. et al

in Analytical and Bioanalytical Chemistry (2004), 378(3), 655-663

We have studied stable transformed human mammary cell lines with highly inducible steroid receptor-mediated luciferase reporter gene expression. Cells responding specifically to glucocorticoids ... [more ▼]

We have studied stable transformed human mammary cell lines with highly inducible steroid receptor-mediated luciferase reporter gene expression. Cells responding specifically to glucocorticoids, progestagens, androgens, or estrogens are described and characterized. The use of this high-throughput, cell-based assay for analysis of steroid (ant)agonists is reported. Systematic characterization of endocrine-disrupting activity on human receptors and in a human-cell system is interpreted for a selection of xenobiotics. We show that the phytoestrogens apigenin and genistin have progestagenic and androgenic activity, respectively. Finally, application of cell-based assays to the analysis of environmental samples is discussed. [less ▲]

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See detailDR-CALUX((R)) screening of food samples: evaluation of the quantitative approach to measure dioxin, furans and dioxin-like PCBs
Scippo, Marie-Louise ULg; Eppe, Gauthier ULg; De Pauw, Edwin ULg et al

in Talanta (2004), 63(5), 1193-1202

European legislation laid down maximum tolerable levels of dioxin in feed and food as well as analytical method requirements. In order to face with large monitoring programs, it was foreseen in the EU ... [more ▼]

European legislation laid down maximum tolerable levels of dioxin in feed and food as well as analytical method requirements. In order to face with large monitoring programs, it was foreseen in the EU strategy to integrate screening methods, using either a qualitative (screening) approach, or a quantitative approach. In this study, dioxin results obtained using the Dioxin Responsive Chemical-Activated LUciferase gene eXpression (DR-CALUX(R)) cell-based assay (quantitative approach), were compared with gas chromatography-high resolution mass spectrometry (GC-HRMS) analyses data. Instead of using World Health Organization-toxic equivalent factor (WHO-TEF), the comparison was based on the assessment of relative effective potencies (REPs) for each congener of the 17 toxic 2,3,7,8-polychlorodibenzo-p-dioxins/furans (PCDD/Fs) and 12 dioxin-like polychlorobiphenyls (DL-PCBs). According to published data, DR-CALUX(R)-REP evaluated here appear similar to WHO-TEF for PCDD/Fs while lower values were observed for DL-PCBs. We analyzed two "home made" contaminated fat samples, displaying both the same WHO-toxic equivalent quantities (WHO-TEQ) concentration (12 pg WHO-TEQ g(-1)). They were spiked with either a low or a high amount of DL-PCBs. In both cases, the DR-CALUX(R) measured concentration (picogram 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) eq. g(-1)) corresponded to the PCDD/Fs WHO-TEQ concentration only. A good agreement was nevertheless found between the DR-CALUX(R) measurements and the recalculated DR-CALUX(R)-TEQ contents (using DR-CALUX(R)-REP instead of WHO-TEF), demonstrating that the observed response was due, in both cases, to the addition of the responses of the standards added to the fat. By contrast, in real contaminated samples (feed or cod liver samples), DR-CALUX(R) measured concentrations were similar to WHO-TEQ GC-HRMS measured concentrations. But, depending on the PCDD/Fs and DL-PCBs congener content, the DR-CALUX(R) measured concentrations were either lower or higher than calculated DR-CALUX(R)-TEQ contents, demonstrating that possible co-extracted contaminants contributed to the CALUX response. Owing to these divergences, the quantitative determination of dioxin-like content in food and feed using CALUX as screening method is questionable, except for samples displaying constant congener patterns, in which cases, correction factors could be applied. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailRecombinant human estrogen, androgen and progesterone receptors for detection of potential endocrine disruptors
Scippo, Marie-Louise ULg; Argiris, Catherine; Van de Weerdt, Cécile ULg et al

in Analytical and Bioanalytical Chemistry (2004), 378(3), 664-669

This work reports the binding capacity of various chemicals (so-called endocrine disruptors) to recombinant human steroid receptors (hERalpha, hPR and hAR). The tested chemicals are organochlorine ... [more ▼]

This work reports the binding capacity of various chemicals (so-called endocrine disruptors) to recombinant human steroid receptors (hERalpha, hPR and hAR). The tested chemicals are organochlorine insecticides (DDT and its metabolites, methoxychlor, aldrin, dieldrin, chlordecone, lindane, trichlorobenzene), estrogenic insecticides (endosulfan, toxaphene, nonachlor), herbicides (alachlor and atrazine), fungicides (benomyl and vinclozolin), industrial chemicals (nonylphenol, bisphenol A, diphenylphtalate), antioxidants (butylated hydroxyanisol) and some phytoestrogens. Except for phytoestrogens, most of the tested chemicals (DDT and its metabolites, aldrin, alpha- and beta-endosulfan, toxaphen, trans-nonachlor) show higher affinities for hPR than for hERalpha, indicating that the interaction with the progesterone receptor could contribute to the endocrine-disrupting effects imputed to these chemicals. We propose to use binding assays using recombinant human steroid receptors as screening tools for the detection of endocrine disruptors in various samples. [less ▲]

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See detailReceptor-based screening assays: New perspectives in anti-doping control
Scippo, Marie-Louise ULg; Willemsen, Philippe; Danyi, Sophie ULg et al

in Chromatographia (2004), 59(Suppl. S), 23-27

The so-called "growth promoters", steroid hormones and beta-agonists, are currently controlled by using hyphenated analytical methods (chromatography coupled to mass spectrometry) or, sometimes for ... [more ▼]

The so-called "growth promoters", steroid hormones and beta-agonists, are currently controlled by using hyphenated analytical methods (chromatography coupled to mass spectrometry) or, sometimes for screening purposes, on immunoassays. These methods are often too specific to allow an effective multianalyte control. To develop more efficient assays, the use of hormonal receptors as detection tools (receptor-based binding assays and cell-based assays) is proposed. Receptor-based assays represent useful tools in screening of hormonal residues in food, but they could also be applied in doping control (to detect "new" hormonal substances). Furthermore, these assays could be used to monitor the human exposure to endocrine disruptors. [less ▲]

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See detailComparison of the rat and mouse cell lines commercially available for CALUX bioassays
Goeyens, Leo; Windal, Isabelle; Scippo, Marie-Louise ULg et al

in Organohalogen compounds (2004), 66

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