Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Roasting carob flour decreases the capacity to bind glycoconjugates of bile acids
    Rijs, Phylyne van; Fogliano, Vincenzo - \ 2020
    Food & Function 11 (2020)7. - ISSN 2042-6496 - p. 5924 - 5932.

    Carob is the fruit obtained from Ceratonia siliqua L. and it is a source of bioactive compounds that have been linked to several health promoting effects, including lowering blood cholesterol concentration. The objective of this study was to connect the physicochemical changes of carob flour occurring during roasting with its capacity to bind glycoconjugates of bile acids. Carob flour samples were roasted for different times at 150 °C and chemically characterized by measuring the concentrations of tannins and polyphenols. Data showed that carob flour binds high amounts of bile acids: 732.6 μmol of bound bile acid per g of carob flour which is comparable to the 836.2 μmol per g bound by cholestyramine, a known cholesterol lowering drug. The carob flour ability to bind cholesterol decreases up to 40% during roasting. Data suggested that tannins and insoluble components play a major role in binding bile salts, as a result of hydrophobic interactions.

    Environmental hotspots for azole resistance selection of aspergillus fumigatus, the netherlands
    Schoustra, Sijmen E. ; Debets, Alfons J.M. ; Rijs, Antonius J.M.M. ; Zhang, Jianhua ; Snelders, Eveline ; Leendertse, Peter C. ; Melchers, Willem J.G. ; Rietveld, Anton G. ; Zwaan, Bas J. ; Verweij, Paul E. - \ 2019
    Emerging Infectious Diseases 25 (2019)7. - ISSN 1080-6040 - p. 1347 - 1353.

    Azole resistance is a major concern for treatment of infections with Aspergillus fumigatus. Environmental resistance selection is a main route for Aspergillus spp. to acquire azole resistance. We investigated the presence of environmental hotspots for resistance selection in the Netherlands on the basis of the ability of A. fumigatus to grow and reproduce in the presence of azole fungicide residues. We identified 3 hotspots: Flower bulb waste, green waste material, and wood chippings. We recovered azole-resistant A. fumigatus from these sites; all fungi contained cyp51A tandem repeat–mediated resistance mechanisms identical to those found in clinical isolates. Tebuconazole, epoxiconazole, and prothioconazole were the most frequently found fungicide residues. Stockpiles of plant waste contained the highest levels of azole-resistant A. fumigatus, and active aerobic composting reduced Aspergillus colony counts. Preventing plant waste stockpiling or creating unfavorable conditions for A. fumigatus to grow in stockpiles might reduce environmental resistance burden.

    Discrimination of aspergillosis, mucormycosis, fusariosis, and scedosporiosis in formalin-fixed paraffin-embedded tissue specimens by use of multiple real-time quantitative PCR assays
    Salehi, Elham ; Hedayati, Mohammad T. ; Zoll, Jan ; Rafati, Haleh ; Ghasemi, Maryam ; Doroudinia, Atosa ; Abastabar, Mahdi ; Tolooe, Ali ; Snelders, Eveline ; Lee, Henrich A. Van Der; Rijs, Antonius J.M.M. ; Verweij, Paul E. ; Seyedmousavi, Seyedmojtaba ; Melchers, Willem J.G. - \ 2016
    Journal of Clinical Microbiology 54 (2016)11. - ISSN 0095-1137 - p. 2798 - 2803.

    In a retrospective multicenter study, 102 formalin-fixed paraffin-embedded (FFPE) tissue specimens with histopathology results were tested. Two 4- to 5-μmFFPE tissue sections from each specimen were digested with proteinase K, followed by automated nucleic acid extraction. Multiple real-time quantitative PCR (qPCR) assays targeting the internal transcribed spacer 2 (ITS2) region of ribosomal DNA, using fluorescently labeled primers, was performed to identify clinically important genera and species of Aspergillus, Fusarium, Scedosporium, and the Mucormycetes. The molecular identification was correlated with results from histological examination. One of the main findings of our study was the high sensitivity of the automated DNA extraction method, which was estimated to be 94%. The qPCR procedure that was evaluated identified a range of fungal genera/species, including Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, Aspergillus niger, Fusarium oxysporum, Fusarium solani, Scedosporium apiospermum, Rhizopus oryzae, Rhizopus microsporus, Mucor spp., and Syncephalastrum. Fusarium oxysporum and F. solani DNA was amplified from five specimens from patients initially diagnosed by histopathology as having aspergillosis. Aspergillus flavus, S. apiospermum, and Syncephalastrum were detected from histopathological mucormycosis samples. In addition, examination of four samples from patients suspected of having concomitant aspergillosis and mucormycosis infections resulted in the identification of two A. flavus isolates, one Mucor isolate, and only one sample having both R. oryzae and A. flavus. Our results indicate that histopathological features of molds may be easily confused in tissue sections. The qPCR assay used in this study is a reliable tool for the rapid and accurate identification of fungal pathogens to the genus and species levels directly from FFPE tissues.

    Landbouwpraktijk en waterkwaliteit in Nederland: toestand (2012-2014) en trend (1992-2014)
    Fraters, B. ; Hooijboer, A.E.J. ; Vrijhoef, A. ; Claessens, J. ; Kotte, M.C. ; Rijs, G.B.J. ; Denneman, A.I.M. ; Bruggen, C. van; Daatselaar, C.H.G. ; Begeman, H.A.L. ; Bosma, J.N. - \ 2016
    Bilthoven : Rijksinstituut voor Volksgezondheid en Milieu (RIVM rapport 2016-0076) - 191
    oppervlaktewaterkwaliteit - grondwaterkwaliteit - mestbeleid - landbouw en milieu - nitraat - eutrofiëring - bemesting - monitoring - waterverontreiniging - surface water quality - groundwater quality - manure policy - agriculture and environment - nitrate - eutrophication - fertilizer application - monitoring - water pollution
    Stikstof en fosfaat zijn essentiële stoffen in mest die landbouwbedrijven gebruiken om de productie te bevorderen. Teveel stikstof en fosfaat is echter schadelijk. Het verschil tussen de aan- en afvoer van stikstof naar en van landbouwbedrijven in Nederland, het zogeheten stikstofoverschot, is tussen 1992 en 2014 gehalveerd. Het fosfaatoverschot is nagenoeg verdwenen. De nitraatconcentraties in het water op landbouwbedrijven zijn gedaald en de kwaliteit van het oppervlaktewater is verbeterd. Ten opzichte van de vorige monitoringronde (2008-2011) zijn de verbeteringen in de waterkwaliteit echter beperkt. De nutriëntenconcentraties zullen naar verwachting wel blijven dalen, maar de gewenste situatie zal in het grondwater niet overal worden bereikt. Ook zal de kwaliteit van het oppervlaktewater veelal onvoldoende blijven. Dit blijkt uit een inventarisatie van de grond­ en oppervlaktewaterkwaliteit en de landbouwpraktijk.
    High-level pan-azole-resistant aspergillosis
    Ingen, Jakko Van; Lee, Henrich A.L. Van Der; Rijs, Antonius J.M.M. ; Snelders, Eveline ; Melchers, Willem J.G. ; Verweij, Paul E. - \ 2015
    Journal of Clinical Microbiology 53 (2015)7. - ISSN 0095-1137 - p. 2343 - 2345.

    High-level pan-azole-resistant Aspergillus fumigatus was recovered from four patients with chronic lung disease. In one patient, the development of progressive resistance followed long-term azole therapy and switching between antifungal azoles. The highlevel pan-azole-resistant phenotypes were not associated with a specific cyp51A gene mutation. New strategies that avoid the development of progressive azole resistance are needed.

    Genotype-phenotype complexity of the TR46/Y121F/T289A cyp51A azole resistance mechanism in Aspergillus fumigatus
    Snelders, Eveline ; Camps, Simone M.T. ; Karawajczyk, Anna ; Rijs, Antonius J.M.M. ; Zoll, Jan ; Verweij, Paul E. ; Melchers, Willem J.G. - \ 2015
    Fungal Genetics and Biology 82 (2015). - ISSN 1087-1845 - p. 129 - 135.
    Aspergillus fumigatus - Cyp51A - Homology modelling - Multi-azole resistance

    The Aspergillus fumigatus cyp51A gene TR46/Y121F/T289A mutation is a new emerging resistance mechanism with high-level voriconazole (VOR) resistance, and elevated MICs to all other medical azoles. This is highly worrisome as VOR is the primary drug for the treatment of many aspergillus diseases. The 46 base pair tandem repeat (TR46) is positioned at the same location of the cyp51A gene promoter region as has been described for other tandem repeats. The exact role of the TR46 in combination with the two amino acid changes (Y121F and T289A) in the CYP51A protein is unknown. In this study this azole resistance mechanism was investigated by recombinant analysis study combined with homology modelling. MICs of the TR46/Y121F/T289A recombinant corresponded to the MICs of the original clinical isolates containing the same mutations with high-level resistance to VOR. The TR46 or Y121F by itself has only a moderate effect on azole susceptibility. The combination of TR46/Y121F, however, appears to be highly resistant not only for VOR but also for itraconazole (ITZ). The genetic change of T289A in combination with TR46 or by itself has no significant effect on the phenotype but moderates the phenotype of the ITZ resistance only in the presence of Y121F. The striking resistant phenotype of the TR46/Y121F mutant is supported by the structural analysis of the CYP51A homology model. The A. fumigatus CYP51A Y121 residue forms an H-bond with the heme centre of the enzyme. Disruption of the H-bond by the Y121F substitution destabilizes the active centre of CYP51A which appears to be essential with respect to azole resistance. In CYP51A-azole complexes, residue T289 is in close proximity of the azole moiety of VOR. Replacement of the polar amino acid threonine by the more hydrophobic amino acid alanine might promote more stable drug-protein interactions and has thereby an impact on ITZ susceptibility, which is confirmed by the MICs of the genetic recombinants.

    Discovery of a hapE Mutation That Causes Azole Resistance in Aspergillus fumigatus through Whole Genome Sequencing and Sexual Crossing
    Camps, Simone M.T. ; Dutilh, Bas E. ; Arendrup, Maiken C. ; Rijs, Antonius J.M.M. ; Snelders, Eveline ; Huynen, Martijn A. ; Verweij, Paul E. ; Melchers, Willem J.G. - \ 2012
    PLoS ONE 7 (2012)11. - ISSN 1932-6203

    Azole compounds are the primary therapy for patients with diseases caused by Aspergillus fumigatus. However, prolonged treatment may cause resistance to develop, which is associated with treatment failure. The azole target cyp51A is a hotspot for mutations that confer phenotypic resistance, but in an increasing number of resistant isolates the underlying mechanism remains unknown. Here, we report the discovery of a novel resistance mechanism, caused by a mutation in the CCAAT-binding transcription factor complex subunit HapE. From one patient, four A. fumigatus isolates were serially collected. The last two isolates developed an azole resistant phenotype during prolonged azole therapy. Because the resistant isolates contained a wild type cyp51A gene and the isolates were isogenic, the complete genomes of the last susceptible isolate and the first resistant isolate (taken 17 weeks apart) were sequenced using Illumina technology to identify the resistance conferring mutation. By comparing the genome sequences to each other as well as to two A. fumigatus reference genomes, several potential non-synonymous mutations in protein-coding regions were identified, six of which could be confirmed by PCR and Sanger sequencing. Subsequent sexual crossing experiments showed that resistant progeny always contained a P88L substitution in HapE, while the presence of the other five mutations did not correlate with resistance in the progeny. Cloning the mutated hapE gene into the azole susceptible akuBKU80 strain showed that the HapE P88L mutation by itself could confer the resistant phenotype. This is the first time that whole genome sequencing and sexual crossing strategies have been used to find the genetic basis of a trait of interest in A. fumigatus. The discovery may help understand alternate pathways for azole resistance in A. fumigatus with implications for the molecular diagnosis of resistance and drug discovery.

    Report of the Horse Mackerel Exchange and Workshop 2006
    Bolle, L.J. ; Abaunza, P. ; Albrecht, C. ; Dijkman Dulkes, H.J.A. ; Duenas, C. ; Gentschouw, G. ; Gill, H. ; Holst, G. ; Moreira, A. ; Mullins, E. ; Rico, I. ; Rijs, S.A. ; Smith, T. ; Thaarup, A. ; Ullewelt, J. - \ 2011
    IJmuiden : Centrum voor Visserijonderzoek (CVO report 11.007) - 26
    trachurus trachurus - visbestand - trachurus trachurus - fishery resources
    Following a recommendation from PGCCDBS, a workshop on age calibration of horse mackerel was carried out. The workshop was preceded by an exchange. The objectives were: to improve the quality of horse mackerel readings by international calibration. In particular, attempt to resolve the observed differences between countries. Estimate the accuracy and precision of the age readings before and after the intercalibration. Take into account differences between areas and methods. Training of new horse mackerel readers.
    Possible Environmental Origin of Resistance of Aspergillus fumigatus to Medical Triazoles
    Snelders, E. ; Veld, R. ; Rijs, A. ; Kema, G.H.J. ; Melchers, W.J.G. ; Verweij, P.E. - \ 2009
    Applied and Environmental Microbiology 75 (2009)12. - ISSN 0099-2240 - p. 4053 - 4057.
    affecting degradation rates - 2 soil types - itraconazole resistance - azole antifungals - cross-resistance - section fumigati - fungicides - mechanisms - gene - neosartorya
    We reported the emergence of resistance to medical triazoles of Aspergillus fumigatus isolates from patients with invasive aspergillosis. A dominant resistance mechanism was found, and we hypothesized that azole resistance might develop through azole exposure in the environment rather than in azole-treated patients. We investigated if A. fumigatus isolates resistant to medical triazoles are present in our environment by sampling the hospital indoor environment and soil from the outdoor environment. Antifungal susceptibility, resistance mechanisms, and genetic relatedness were compared with those of azole-resistant clinical isolates collected in a previous study. Itraconazole-resistant A. fumigatus (five isolates) was cultured from the indoor hospital environment as well as from soil obtained from flower beds in proximity to the hospital (six isolates) but never from natural soil. Additional samples of commercial compost, leaves, and seeds obtained from a garden center and a plant nursery were also positive (four isolates). Cross-resistance was observed for voriconazole, posaconazole, and the azole fungicides metconazole and tebuconazole. Molecular analysis showed the presence of the dominant resistance mechanism, which was identical to that found in clinical isolates, in 13 of 15 environmental isolates, and it showed that environmental and clinical isolates were genetically clustered apart from nonresistant isolates. Patients with azole-resistant aspergillosis might have been colonized with azole-resistant isolates from the environment.
    Emergence of azole resistance in Aspergillus fumigatus and spread of a single resistance mechanism
    Snelders, Eveline ; Lee, Henrich A.L. Van Der; Kuijpers, Judith ; Rijs, Anthonius J.M.M. ; Varga, János ; Samson, Robert A. ; Mellado, Emilia ; Donders, Rogier T. ; Melchers, Willem J.G. ; Verweij, Paul E. - \ 2008
    PLOS Medicine 5 (2008)11. - ISSN 1549-1277 - p. 1629 - 1637.

    Background: Resistance to triazoles was recently reported in Aspergillus fumigatus isolates cultured from patients with invasive aspergillosis. The prevalence of azole resistance in A. fumigatus is unknown. We investigated the prevalence and spread of azole resistance using our culture collection that contained A. fumigatus isolates collected between 1994 and 2007. Methods and Findings: We investigated the prevalence of itraconazole (ITZ) resistance in 1,912 clinical A. fumigatus isolates collected from 1,219 patients in our University Medical Centre over a 14-y period. The spread of resistance was investigated by analyzing 147 A. fumigatus isolates from 101 patients, from 28 other medical centres in The Netherlands and 317 isolates from six other countries. The isolates were characterized using phenotypic and molecular methods. The electronic patient files were used to determine the underlying conditions of the patients and the presence of invasive aspergillosis. ITZ-resistant isolates were found in 32 of 1,219 patients. All cases were observed after 1999 with an annual prevalence of 1.7% to 6%. The ITZ-resistant isolates also showed elevated minimum inhibitory concentrations of voriconazole, ravuconazole, and posaconazole. A substitution of leucine 98 for histidine in the cyp51A gene, together with two copies of a 34-bp sequence in tandem in the gene promoter (TR/L98H), was found to be the dominant resistance mechanism. Microsatellite analysis indicated that the ITZ-resistant isolates were genetically distinct but clustered. The ITZ-sensitive isolates were not more likely to be responsible for invasive aspergillosis than the ITZ-resistant isolates. ITZ resistance was found in isolates from 13 patients (12.8%) from nine other medical centres in The Netherlands, of which 69% harboured the TR/L98H substitution, and in six isolates originating from four other countries. Conclusions: Azole resistance has emerged in A. fumigatus and might be more prevalent than currently acknowledged. The presence of a dominant resistance mechanism in clinical isolates suggests that isolates with this mechanism are spreading in our environment.

    Integrated assessment of estrogens and xenoestrogens in the aquatic environment of the Netherlands: weight of evidence and ecological relevance
    Vethaak, A.D. ; Schrap, S.M. ; Lahr, J. ; Rijs, G.B.J. ; Voogt, P. de - \ 2006
    In: Estrogens and xenoestrogens in the aquatic environment: an integrated approach for field monitoring and effect assessment / Vethaak, D., Schrap, M., de Voogt, P., Pensacola FL (USA) / Brussels (Belgium) : SETAC - ISBN 9781880611852 - p. 315 - 334.
    A survey of estrogenic effects in fish in regional inland waters in the Netherlands receiving discharges from sewage treatment plants
    Lahr, J. ; Gerritsen, A.A.M. ; Klein Breteler, J.G.P. ; Dubbeldam, M.C. ; Mullem, A. van; Pieters, J.P.F. ; Rijs, G.B.J. - \ 2006
    In: Estrogens and xenoestrogens in the aquatic environment: an integrated approach for field monitoring and effect assessment / Vethaak, D., Schrap, M., de Voogt, P., Pensacola FL (USA) / Brussels (Belgium) : SETAC - ISBN 9781880611852 - p. 179 - 192.
    The Dutch Contribution to PLACES (the plaice and cod egg survey of the North Sea in 2004)
    Bolle, L.J. ; Damme, C.J.G. van; Dickey-Collas, M. ; Bakker, C. ; Os-Koomen, E. van; Hamers, J.M.P. ; Rijs, S.A. ; Stoker, M. ; Vries, M. de - \ 2006
    IJmuiden : RIVO (Report / RIVO C019/06) - 31
    kabeljauw - schol - visserijbeheer - noordzee - cod - plaice - fishery management - north sea
    Nederland neemt deel aan de ICES Planning Group on North Sea Cod and Plaice Egg Surveys (PGEGGS) en heeft een belangrijke bijdrage geleverd aan de internationale schol en kabeljauw eisurvey van 2004 (PLACES). De belangrijkste doelstellingen van deze survey waren het in kaart brengen van de paaigronden van schol en kabeljauw. Genetische technieken zijn gebruikt om onderscheid te maken tussen de eieren van kabeljauw, schelvis, wijting en koolvis, die overlappende eidiameter-verdelingen hebben. Schol paait in dezelfde gebieden als in het verleden gerapporteerd, maar de paaiactiviteit in de Duitse Bocht lijkt relatief te zijn toegenomen. Kabeljauw paait ook in de gebieden die voorheen bekend stonden als paaigronden, maar met een relatieve afname van de paaiactiviteit in de Zuidelijke Bocht. Er is geen toename in paaiactiviteit waargenomen in de noordelijke Noordzee, hetgeen in strijd is met de verwachting op grond van de verspreiding van volwassen vis zoals waargenomen in onderzoeksreizen.
    An integrated assessment of estrogenic contamination and biological effects in the aquatic environment of the Netherlands
    Vethaak, A.D. ; Lahr, J. ; Schrap, S.M. ; Belfroid, A.C. ; Rijs, G.B.J. ; Gerritsen, A. ; Boer, J. de; Bulder, A.S. ; Grinwis, G.C.M. ; Kuiper, R.V. ; Legler, J. ; Murk, A.J. ; Peijnenburg, W. ; Verkaar, H.J.M. ; Voogt, P. de - \ 2005
    Chemosphere 59 (2005)4. - ISSN 0045-6535 - p. 511 - 524.
    waterverontreiniging - hormonen - aquatisch milieu - monitoring - nederland - aquatische ecosystemen - hormoonverstoorders - water pollution - hormones - aquatic environment - monitoring - netherlands - aquatic ecosystems - endocrine disruptors - sewage-treatment plants - flounder platichthys-flesus - reporter gene assays - e-screen assay - waste-water - surface-water - alkylphenol polyethoxylates - degradation-products - sexual disruption
    An extensive study was carried out in the Netherlands on the occurrence of a number of estrogenic compounds in surface water, sediment, biota, wastewater, rainwater and on the associated effects in fish. Compounds investigated included natural and synthetic hormones, phthalates, alkylphenol(ethoxylate)s and bisphenol-A. The results showed that almost all selected (xeno-)estrogens were present at low concentrations in the aquatic environment. Locally, they were found at higher levels. Hormones and nonylphenol(ethoxylate)s were present in concentrations that are reportedly high enough to cause estrogenic effects in fish. Field surveys did not disclose significant estrogenic effects in male flounder (Platichthys flesus) in the open sea and in Dutch estuaries. Minor to moderate estrogenic effects were observed in bream (Abramis brama) in major inland surface waters such as lowland rivers and a harbor area. The prevalence of feminizing effects in male fish is largest in small regional surface waters that are strougly influenced by sources of potential hormone-disrupting compounds. High concentrations of plasma vitellogenin and an increased prevalence of ovotestes occurred in wild male bream in a small river receiving a considerable load of effluent from a large sewage treatment plant. After employing in vitro and in vivo bioassays, both in situ and in the laboratory, we conclude that in this case hormones (especially 17a-ethynylestradiol) and possibly also nonylphenol(ethoxylate)s are primarily responsible for these effects.
    Campylobacter in zwemwater en mogelijke emissiebronnen
    Ruiter, H. ; Rijs, G. ; Jacobs-Reitsma, W.F. ; Leenen, I. - \ 2004
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 37 (2004)12. - ISSN 0166-8439 - p. 19 - 21.
    campylobacter - zwemmen - waterverontreiniging - humane ziekten - waterkwaliteit - besmetting - oppervlaktewater - afvoerwater - volksgezondheid - campylobacter - swimming - water pollution - human diseases - water quality - contamination - surface water - effluents - public health
    Campylobacter vormt samen met Salmonella en Shigella één van de belangrijkste bacteriële ziekteverwekkers van het maagdarmkanaal bij de mens. De bacterie Campylobacter komt voor bij eenden, meeuwen, kippen en kalkoenen, maar is ook aanwezig in koeien, varkens en schapen. Al deze dieren zijn drager, maar worden er zelf niet ziek van. Infecties met Campylobacter leiden in Nederland jaarlijks tot circa honderdduizend gevallen van maagdarmstoornissen en enkele duizenden gevallen van reactieve artritis (spierontsteking). De infectieuze dosis is laag en de besmetting vindt doorgaans plaats via de fecaal-orale route. Uit een inventariserend onderzoek blijkt dat naast de algemeen bekende besmettingsroute via voedsel (voornamelijk pluimveevlees) ook verontreinigd zwemwater een besmettingsbron kan vormen
    Voortgangsrapportage van de Nederlandse bijdrage aan PLACES (plaice and cod egg survey)
    Bolle, L.J. ; Damme, C.J.G. van; Os-Koomen, E. van; Rijs, S.A. ; Bakker, C. ; Dickey-Collas, M. - \ 2004
    IJmuiden : RIVO (Rapport / RIVO C050/04) - 8
    visserij - vissen - kuitschieten - kabeljauw - schol - fisheries - fishes - spawning - cod - plaice
    Eisurvey om meer inzicht te krijgen waar zich de kabeljauw- en scholpaaigronden zich bevinden. Deze informatie is nodig om adequate beschermingsmaatregelen te kunnen ontwikkelen tegen de afnemende stand van schol en kabeljauw
    Oestrogene effecten in vissen in regionale wateren nabij rwzi's
    Rijs, G. ; Gerritsen, A. ; Lahr, J. ; Bulder, A. - \ 2004
    H2O : tijdschrift voor watervoorziening en afvalwaterbehandeling 37 (2004)5. - ISSN 0166-8439 - p. 15 - 18.
    vissen - abramis brama - oestrogenen - hormonen - aquatisch milieu - oppervlaktewater - waterverontreiniging - rioolafvalwater - nederland - aquatische ecosystemen - zuiveringsinstallaties - fishes - abramis brama - oestrogens - hormones - aquatic environment - surface water - water pollution - sewage effluent - netherlands - aquatic ecosystems - purification plants
    Het Landelijk Onderzoek oEstrogene Stoffen (LOES) heeft laten zien dat hormoonontregelende stoffen bijna overal in lage concentraties in het Nederlandse watermilieu voorkomen. Vissen in regionale wateren blijken evenwel een groter risico te lopen op nadelige effecten, zoals vervrouwelijking, dan de vissen in de wat grotere wateren. De oorzaak hiervoor lijkt te liggen in het feit dat wanneer regionale wateren onder directe invloed van lozingen met hormoonontregelende stoffen staan in kleinere wateren relatief weinig verdunning optreedt. Eén van de emissiebronnen die uitgebreid onderzocht is, is het effluent van een rioolwaterzuivering
    Detection of estrogenic potency in wastewater and surface water with three in vitro bioassays
    Murk, A.J. ; Legler, J. ; Lipzig, M.M.H. van; Meerman, J.H.N. ; Belfroid, A.C. ; Spenkelink, A. ; Burg, B. van der; Rijs, G.B.J. ; Vethaak, D. - \ 2002
    Environmental Toxicology and Chemistry 21 (2002)1. - ISSN 0730-7268 - p. 16 - 23.
    oppervlaktewater - afvalwater - oestrogenen - biotesten - hormonen - surface water - waste water - oestrogens - hormones - bioassays
    A study was performed to optimize sample preparation and application of three in vitro assays for measuring estrogenic potency in environmental extracts. The three assays applied were an estrogen receptor (ER)-binding assay and two reporter gene effect assays: a yeast estrogen screen (YES) and the ER-mediated chemically activated luciferase gene expression (ER-CALUX) assay. All assays were able to detect estrogenicity, but the amounts of material needed for the assays differed greatly between the three assays (ER-binding assay ≫ YES > ER-CALUX). In addition, in the ER-binding assay, both agonists and antagonists give an estrogenic response, resulting in higher estradiol equivalency (EEQ) levels than both the ER-CALUX and the YES assay for the same samples. The EEQs found in wastewater treatment plants (WTPs) with the ER-CALUX assay were in the range of 4 to 440 and 0.11 to 59 pmol/L for influent and effluent, respectively. Water extracts from four large rivers had levels ranging from 0.25 to 1.72 pmol/L. Extracts from suspended matter and sludge contained estrogenic potency of 0.26 to 2.49 and 1.6 to 41 pmol EEQ/g dry weight, respectively. In WTPs, the average reduction of estrogenic potency in effluent compared to influent was 90 to 95% in municipal WTPs and about 50% in industrial WTPs. In influent, 30% of the ER-CALUX activity could not be explained by the calculated potencies based on chemical analysis of a number of known (xeno)estrogens; in effluent the unexplained fraction was 80%. These first results of analyzing estrogenic potency in WTP water and surface water in The Netherlands indicate that further studies are warranted to investigate the actual risks for aquatic systems.
    Analysis of the occurrence of PCB congeners as potential biomarkers for endocrine disruption by P450 inducers: where to draw the line for adverse effects?
    Brink, N.W. van den; Bosveld, A.T.C. - \ 2001
    In: Endocrine-disrupting compounds: wildlife and human health risks; proceedings of a symposium, 27 October 1998, The Hague. Middelburg, RIKZ, s.a / Vethaak, A.D., Rijs, G.B.J., van der Burg, B., Brouwer, A., - p. 73 - 77.
    fauna - bever - ecotoxicologie - endocrinologie - marter - milieuverontreiniging - otter - spitsmuis - zoogdieren
    Effects of hormone disrupting chemicals in terrestrial mammalian wildlife: exposure levels and effects on reproductive organs in common shrews (Sorex araneus) in the Biesbosch
    Bosveld, A.T.C. ; Jong, J.B.F. de; Bie, P.A.F. de - \ 2001
    In: Endocrine-disrupting compounds: wildlife and human health risks; proceedings of a symposium, 27 October 1998, The Hague. Middelburg, RIKZ, s.a / Vethaak, A.D., Rijs, G.B.J., van der Burg, B., Brouwer, A., - p. 49 - 53.
    fauna - ecotoxicologie - endocrinologie - fauna - milieuverontreiniging - spitsmuis - zoogdieren - Zuid-Holland - Brabant - Biesbosch
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