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Bisphenol
Terms modified by Bisphenol Selected AbstractsEffects of bisphenol A and tetrabromobisphenol A on sex organ development in quail and chicken embryosENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Cecilia Berg Abstract The plastic monomere bisphenol A (BPA) and the flame retardant tetrabromobisphenol A (TBBPA) were examined for estrogen-like developmental effects on the reproductive organs in avian embryos. The synthetic estrogen diethylstilbestrol (DES) was used as a positive control. The test compounds were injected into the yolk of quail and chicken eggs early during incubation and the embryos were examined 2 d before anticipated hatching. At 200 ,g/g egg, BPA induced Müllerian duct (embryonic oviduct) malformation in female quail embryos and feminization of the left testis (ovotestis) in male chicken embryos. The estrogenic potency of BPA compared with DES was species and endpoint specific. Müllerian duct malformation was the most sensitive endpoint in quail embryos, whereas ovotestis formation was the most sensitive response in chicken embryos. Tetrabromobisphenol A caused high embryo mortality at 45 ,g/g egg in both species, but no estrogen-like effects were observed. Bisphenol A caused mortality only in chicken embryos at 67 and 200 ,g/g egg. To our knowledge, this is the first report on estrogen-like or embryolethal effects of BPA and TBBPA in birds. [source] Enhanced interleukin-4 production in CD4+ T cells and elevated immunoglobulin E levels in antigen-primed mice by bisphenol A and nonylphenol, endocrine disruptors: involvement of nuclear factor-AT and Ca2+IMMUNOLOGY, Issue 1 2003Mee H. Lee Summary Bisphenol A (BPA) and p -nonylphenol (NP) are representative endocrine disruptors (EDs) that may have adverse effects on human health. The influence of these compounds on allergic immune responses remains unclear. In this study, we have examined the effects of BPA and NP on production of interleukin-4 (IL-4), a pro-inflammatory cytokine closely associated with allergic immune responses. Both BPA and NP significantly enhanced IL-4 production in keyhole limpet haemocyanin (KLH)-primed CD4+ T cells in a concentration-dependent manner. Treatment with BPA or NP in vivo resulted in significant increase of IL-4 production in CD4+ T cells and of antigen-specific immunoglobulin E (IgE) levels in the sera of KLH-primed mice. Furthermore, BPA and NP enhanced the activation of IL-4 gene promoter in EL4 T cells transiently transfected with IL-4 promoter/reporter constructs, and the enhancing effect mapped to a region in the IL-4 promoter containing binding sites for nuclear factor (NF)-AT. Activation of T lymphocytes by phorbol 12-myristate 13-acetate/ionomycin resulted in markedly enhanced binding activities to the NF-AT site, which significantly increased upon addition of BPA or NP, as demonstrated by the electrophoretic mobility shift assay, indicating that the transcription factor NF-AT was involved in the enhancing effect of BPA and NP on IL-4 production. The enhancement of IL-4 production by BPA or NP was significantly reduced by nitrendipine, a blocker of Ca2+ influx, and by FK506, a calcineurin inhibitor. FK506 inhibited the NF-AT,DNA binding activity and IL-4 gene promoter activity enhanced by BPA or NP. These results represent the first report describing possible enhancement of allergic response by EDs through increasing IL-4 production in CD4+ T cells and antigen-specific IgE levels in the sera via the stimulation of Ca2+/calcineurin-dependent NF-AT activation. [source] Microwave-Accelerated Polymerization of 2-Phenoxymethyl-1,4,6-trioxaspiro[4,4]nonane with Diglycidyl Ether of Bisphenol AMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 18 2007Judit Canadell Abstract The cationic copolymerization of 2-phenoxymethyl-1,4,6-trioxaspiro[4,4]nonane with DGEBA under microwave irradiation using ytterbium and lanthanum triflates as initiators is described. A comparison with thermal heating showed a great enhancement in the reaction rates and a higher SOE incorporation in the network. The double ring opening of SOE reduces the usual shrinkage of epoxy resins on curing, and it was lower under microwave irradiation. Moreover, the ytterbium triflate initiator lead to a higher incorporation of linear ester moieties in the network than lanthanum triflate. [source] Application of Modified Natural Oils as Reactive Diluents for Epoxy ResinsMACROMOLECULAR SYMPOSIA, Issue 1 2006Piotr Czub Abstract Bisphenol A based low-molecular-weight epoxy resin was modified with epoxidized soybean oil, which exhibit viscosity reducing ability comparable to commercial grade active diluents. The studied compositions showed a non-Newtonian rheological behavior, typical for Bingham liquids. The values of the flow index (n) and the consistency index (k) for the compositions tested in the temperature range 25,65,°C were calculated from the Ostwald-de Waele rheological model and were used to calculate the flow-activation energy (Ea) using the Arhenius equation. Studies of co-crosslinking of mixed oil-resin compositions using isophorone diamine showed essential decrease of the reaction heat and peak maximum temperature. Mechanical properties, thermal stability, water absorption and chemical resistance of the epoxy resin modified with natural oil, were also investigated. Compositions of epoxy resin Ruetapox 0162, modified with the oil diluent, preserved very good mechanical properties of the epoxy resins and demonstrated relatively low water absorption as well as high chemical resistance. The compositions displayed even higher impact strength than pure epoxy resin due to plasticizing effect of the built-in oil. Compositions with the high contents (up to 60 weight %) of the oil were flexible materials with fast elastic recovery. [source] Determination of bisphenol A and 10 alkylphenols in serum using SDS micelle capillary electrophoresis with ,-cyclodextrinBIOMEDICAL CHROMATOGRAPHY, Issue 7 2001Masatoki Katayama A new micelle capillary electrophoresis based on cyclodextrin micellar electrokinetic chromatography (MEKC) for the determination of bisphenol A and 10 alkylphenols in rat serum is reported. Several surfactants and dextrins were studied. Bisphenol A and alkylphenols were separated using a 50,µm,×,50,cm capillary with 20,mM borate phosphate buffer (pH 8.0) containing 20,mM sodium dodecylsulfate and 5,mM ,-cyclodextrin as carrier. The method could determine 0.6,2000,µg/mL of phenols in 100,µL serum by photometric detection at 214,nm. Using 2.0,mL serum, 1.0,ng/mL of phenols could be determined. The relative standards deviations were 6.3,7.7% at 10,µg/mL in serum. The recoveries were 91.8,93.0% with 10,µg/mL serum samples. Copyright © 2001 John Wiley & Sons, Ltd. [source] Bisphenol A diglycidyl ether (BADGE) is a PPAR, agonist in an ECV304 cell lineBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2000David Bishop-Bailey Peroxisome proliferator activated receptors (PPAR)s are nuclear transcription factors of the steroid receptor super-family. One member, PPAR,, a critical transcription factor in adipogenesis, is expressed in ECV304 cells, and when activated participates in the induction of cell death by apoptosis. Here we describe a clone of ECV304 cells, ECV-ACO.Luc, which stably expresses a reporter gene for PPAR activation. ECV-ACO.Luc respond to the PPAR, agonists, 15-deoxy-,12,14 PGJ2, and ciglitizone, by inducing luciferase expression. Furthermore, using ECV-ACO.Luc, we demonstrate that a newly described PPAR, antagonist, bisphenol A diglycidyl ether (BADGE) has agonist activities. Similar to 15-deoxy-,12,14 PGJ2, BADGE induces PPAR, activation, nuclear localization of the receptor, and induces cell death. British Journal of Pharmacology (2000) 131, 651,654; doi:10.1038/sj.bjp.0703628 [source] Dietary exposure to low doses of bisphenol A: Effects on reproduction and development in two generations of C57BL/6J miceCONGENITAL ANOMALIES, Issue 3 2010Kenichi Kobayashi Abstract The present study was conducted to examine the effects of low-dose exposure to bisphenol A on reproduction and development in two generations of mice. Pregnant female C57BL/6J mice (F0) were fed a diet containing low doses of bisphenol A (0, 0.33, 3.3, or 33 ppm) from gestational day 6 through postnatal day 22, and the weanlings (F1 and F2) from each F0 and F1 dam group, respectively, were also fed these same concentrations of bisphenol A ad libitum until sacrifice. There were no treatment-related changes in body weight, body weight gain, food consumption, gestation length, or the number of live births on postnatal day 1 in F0 dams between the control group and bisphenol A groups. Sex ratio and viability were similar in all F1 pups. No treatment-related changes were observed in body weight, food consumption, developmental parameters, anogenital distance, or weight of any of the organs (liver, kidney, heart, spleen, thymus, testis, ovary, or uterus) in F1 and F2 adults in either sex. The epididymis weight was slightly higher with 0.33 and 3.3 ppm in F1 males, but this slight increase was neither dose dependent nor seen across generations. There were no treatment-related effects of bisphenol A on cauda epididymal sperm count or sperm motility in F1 or F2 males. These findings indicate that dietary exposure to bisphenol A between 0.33 and 33 ppm does not adversely affect reproduction or development as assessed in two generations of mice. [source] Contact allergy to epoxy (meth)acrylatesCONTACT DERMATITIS, Issue 1 2009Kristiina Aalto-Korte Background: Contact allergy to epoxy (meth)acrylates, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (bis-GMA), 2,2-bis[4-(2-hydroxy-3-acryloxypropoxy)phenyl]-propane (bis-GA), 2,2-bis[4-(methacryl-oxyethoxy)phenyl] propane (bis-EMA), 2,2-bis[4-(methacryloxy)phenyl]-propane (bis-MA), and glycidyl methacrylate (GMA) is often manifested together with contact allergy to diglycidyl ether of bisphenol A (DGEBA) epoxy resin. Objective: To analyse patterns of concomitant allergic reactions to the five epoxy (meth)acrylates in relation to exposure. Methods: We reviewed the 1994,2008 patch test files at the Finnish Institute of Occupational Health (FIOH) for reactions to the five epoxy (meth)acrylates, and examined the patients' medical records for exposure. Results: Twenty-four patients had an allergic reaction to at least one of the studied epoxy (meth)acrylates, but specific exposure was found only in five patients: two bis-GMA allergies from dental products, two bis-GA allergies from UV-curable printing inks, and one bis-GA allergy from an anaerobic glue. Only 25% of the patients were negative to DGEBA epoxy resin. Conclusions: The great majority of allergic patch test reactions to bis-GMA, bis-GA, GMA and bis-EMA were not associated with specific exposure, and cross-allergy to DGEBA epoxy resin remained a probable explanation. However, independent reactions to bis-GA indicated specific exposure. Anaerobic sealants may induce sensitization not only to aliphatic (meth)acrylates but also to aromatic bis-GA. [source] Electroanalysis of Bisphenol A at a Multiwalled Carbon Nanotubes-gold Nanoparticles Modified Glassy Carbon ElectrodeELECTROANALYSIS, Issue 22 2009Xinman Tu Abstract A sensitive electrochemical method was developed for the determination of bisphenol A (BPA) at a glassy carbon electrode (GCE) modified with a multiwalled carbon nanotubes (MWCNTs)-gold nanoparticles (GNPs) hybrid film, which was prepared based on the electrostatic interaction between positively charged cetyltrimethylammonium bromide (CTAB) and negatively charged MWCNTs and GNPs. The MWCNT-GNPs/GCE exhibited an enhanced electroactivity for BPA oxidation versus unmodified GCE and MWCNTs/GCE. The experimental parameters, including the amounts of modified MWCNTs and GNPs, the pH of the supporting electrolyte, scan rate and accumulation time, were examined and optimized. Under the optimal conditions, the differential pulse voltammetric anodic peak current of BPA was linear with the BPA concentration from 2.0×10,8 to 2×10,5 mol L,1, with a limit of detection of 7.5,nmol L,1. The proposed procedure was applied to determine BPA leached from real plastic samples with satisfactory results. [source] Copper Ion Selective Membrane Electrodes Based on Some Schiff Base DerivativesELECTROANALYSIS, Issue 15-16 2003S. Sadeghi Abstract A series of Schiff base derivatives were studied to characterize their abilities as a copper ion carrier in PVC membrane electrodes. The electrode based on 2,2,-[4,4,diphenyl-methanebis(nitrilomethylidyne)]-bisphenol exhibits a Nernstian response for copper ions over the activity range 8.0×10,6,1.0×10,1 mol L,1 with detection limit of about , mol L,1 of copper ion in comparison with two other Schiff bases. The response time, pH effect and other characteristics of the electrodes were studied in a static mode. The effect of the methyl group substitute on Schiff base structure with SO2 bridging group in different positions with respect to OH group was studied. The results show that behavior of the electrodes is not considerably influenced by the position of methyl substitute. The selectivity coefficients were determined with modified fixed interference method (FIM) and matched potential method (MPM). The proposed electrodes comparatively show good selectivity with respect to alkali, alkaline earth and some transition metal ions. The electrodes were used for the determination of copper in black tea, multivitamin and mineral capsule and as an indicator electrode in potentiometric titration of copper ion. [source] Field-amplified sample injection-micellar electrokinetic capillary chromatography for the analysis of bisphenol A, bisphenol F, and their diglycidyl ethers and derivatives in canned soft drinksELECTROPHORESIS, Issue 9 2010Héctor Gallart-Ayala Abstract Conditions were established for the separation and analysis of bisphenol A, bisphenol F, and their diglycidyl ethers by micellar electrokinetic capillary chromatography (MECC). Good resolution was obtained for all compounds, although in order to achieve the separation of ortho,ortho, ortho,para, and para,para isomers of bisphenol F diglycidyl ether (BFDGE), BFDGE·2H2O and BFDGE·2HCl, it was necessary to use a 25,,m id fused silica capillary. To increase sensitivity, a field-amplified sample injection (FASI)-MECC method was developed using 10,mM SDS solution as injection matrix and a 75,,m id fused silica capillary. Instrumental quality parameters such as LODs (<55,,g/L with standards), linearity (r2>0.999), and run-to-run and day-to-day precisions (RSD values lower than 12.5%) were determined. Finally, the suitability of the FASI-MECC method for the analysis of bisphenol A, bisphenol F, and their diglycidyl ethers in canned soft drinks was evaluated. Quantitation was performed by matrix-matched calibration using a plastic-bottled isotonic drink as matrix. The results showed that FASI-MECC is an economic method for the screening and quantitation of these kinds of compounds in soft drink beverages, with no loss of reproducibility, and effective at concentrations lower than the specific migration level values established by the European Union. [source] Urinary concentrations of bisphenol A in relation to biomarkers of sensitivity and effect and endocrine-related health effectsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2006Mihi Yang Abstract The impact of endocrine-disrupting chemicals (EDCs) on human health is not yet clear because of difficulties in ascertaining their biological effects. In the present study, we evaluated exposure to the EDC, bisphenol A (BPA), in 172 Koreans in relation to biomarkers of susceptibility and effect. The subjects completed questionnaires, which documented occupation, education, lifestyle factors, potential sources of BPA-exposure, and the occurrence of self-diagnosed endocrine disorders. None of the subjects were occupationallay exposed to BPA; however, urinary levels of conjugated BPA, determined by HPLC/FD, ranged from 0.03,62.4 ,g/l (median, 7.86). The frequencies of potential susceptibility biomarkers, the UGT1A6-Arg184Ser and the SULT1A1- Arg213His polymorphisms, were not associated with urinary BPA levels, either as single genes or in combination. Indirect effects of BPA exposure on the susceptibility to mutagens were evaluated by comparing urinary BPA concentrations with MNNG-induced sister-chromatid exchange (SCE) in lymphocytes cultured from the subjects. BPA exposure showed marginal or significant associations with theSCEs induced by the low doses of MNNG (0,0.4 mM). However, there was no overall association between urinary BPA levels and MNNG-induced frequency at doses ranging from 0.2,0.6 mM. Finally, we did not detect an association between urinary BPA concentration and endocrine-related disorders. Even though we were unable to find a strong association between BPA exposure and a biological response, possibly because of the limited number of subjects, we observed that most of the subjects were exposed to BPA. Therefore, continuous biological monitoring of BPA is a prudent measure to prevent possible BPA-related health risks. Environ. Mol. Mutagen., 2006. © 2006 Wiley-Liss, Inc. [source] Interaction of bisphenol a with human UDP-glucuronosyltransferase 1A6 enzymeENVIRONMENTAL TOXICOLOGY, Issue 3 2008Nobumitsu Hanioka Abstract The effects of bisphenol A (BPA) on UDP-glucuronosyltransferase 1A6 (UGT1A6) activities in microsomes from human livers and yeast cells expressing human UGT1A6 (humUGT1A6) were investigated. Serotonin (5-HT) and 4-methylumbelliferone (4-MU) were used as the substrates for UGT1A6. BPA dose-dependently inhibited 5-HT and 4-MU glucuronidation activities in both enzyme sources. The IC50 values of BPA for 5-HT and 4-MU glucuronidation activities were 156 and 163 ,M for liver microsomes, and 84.6 and 80.3 ,M for yeast cell microsomes expressing humUGT1A6, respectively. The inhibitory pattern of BPA for 5-HT and 4-MU glucuronidation activities in human liver microsomes exhibited a mixture of competitive and noncompetitive components, with Ki values of 84.9 and 72.3 ,M, respectively. In yeast cell microsomes expressing humUGT1A6, 5-HT glucuronidation activities were noncompetitively inhibited by BPA (Ki value, 65.5 ,M), whereas the inhibition of 4-MU glucuronidation activities by BPA exhibited the mixed type (Ki value, 42.5 ,M). These results suggest that BPA interacts with human UGT1A6 enzyme, and that the interaction may contribute to the toxicity, such as hormone disruption and reproductive effects, of BPA. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Biomarkers for exposure to estrogenic compounds: Gene expression analysis in zebrafish (Danio rerio)ENVIRONMENTAL TOXICOLOGY, Issue 1 2008Ulf Kausch Abstract Gene expression analyses in male zebrafish (Danio rerio) were carried out using microarray technique and quantitative polymerase chain reaction. Genes responding to the exposure to 17,-estradiol, bisphenol A and genistein were identified, among them genes involved in metabolism, reproductional and developmental processes. Threshold levels of 17,-estradiol (200 ng/L), bisphenol A (2000 ,g/L), and genistein (5000 ,g/L) for the upregulation of the vtg1 gene in short-time exposures (11 days) were determined by qPCR. 14k microarrays were used to generate complete lists of genes regulated by these estrogenic compounds. For this purpose, liver samples from 10 exposed zebrafish and 10 controls were processed. In this case the expressions of 211 genes were significantly regulated by 17,-estradiol, 47 by bisphenol A and 231 by genistein. Furthermore, it is shown that fish exposed to 17,-estradiol and genistein have similarities in their gene expression patterns, whereas bisphenol A apparently affected gene expression in a different way. Only genes coding for egg-yolk precursor protein vitellogenin were found to be regulated by all three compounds, which shows that these genes are the only suitable markers for exposure to different estrogenic compounds. The regulated genes were assigned to gene ontology classes. All three estrogenic compounds regulated genes mainly involved in primary and cellular metabolism, but genistein regulated several genes involved in cell cycle-regulation and bisphenol A several genes involved in protein biosynthesis. Genistein also upregulated the expression of four eggshell proteins, which can be used as biomarkers for exposure to this chemical. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] Estrogenic effect of leachates and soil extracts from lysimeters spiked with sewage sludge and reference endocrine disruptersENVIRONMENTAL TOXICOLOGY, Issue 2 2002Halim Dizer Abstract Several experiments were conducted to evaluate the behavior and performance of some potential endocrine disrupters (ECDs). Two in vitro screening assays, one based on MCF7-cell proliferation (E-screen test) and the other on estrogenic receptor activity [enzyme-linked receptor assay (ELRA)], were used for the tests, which were done in lysimeters 80 cm in diameter with depths of 30 cm (shallow) or 90 cm (deep). A sandy soil was used to fill in all lysimeters, which were spiked on the surface with either: (a) a sewage sludge (SS) at a dose equivalent to 20 tons ha,1; (b) a mixture of reference ECDs, comprising 17,- and 17,-estradiol (E2), nonylphenol, octylphenol, and bisphenol A at doses 100 times higher than the maximum concentrations respectively found in the applied SS; or (c) a mixture of ECDs and SS. After percolation of the lysimeters with rain and/or artificial water, five leachates were sampled from each lysimeter during a period of 210 days. Immediately after the lysimeter percolation experiments, four and six soil fractions were dissected from, respectively, the 30-cm and 90-cm lysimeters and extracted by water. Both the leachate and soil extract samples were analyzed for their estrogenicity using the assays indicated above. The E-screen assay was highly sensitive only for some leachate and extract samples but gave no response for most leachates and soil extracts. The results of the ELRA assay suggests a significantly higher estrogenicity of leachate samples from shallow lysimeters compared with that of leachates from deep lysimeters. In contrast, the estrogenic effect measured for soil extracts of shallow lysimeters was lower than that measured for soil extracts of deep lysimeters. The results of the E-screen assay suggests the occurrence of a fast mobilization of applied ECDs and a moderate retardation effect of native ECDs contained in applied SS in the sandy soil used in the lysimeters. In lysimeters spiked with a mixture of SS and ECDs, the washing-out effect of ECDs in the first leachate fraction decreased, but the distribution of ECDs in the lysimeters increased. The relatively high estrogenic impact measured for soil water extracts suggests that the ECDs were mostly associated with water-soluble fractions of organic matter and/or water-suspended fractions of the mineral soil matrix. The application of SS to agricultural and forest fields may determine the immobilization of ECDs in soil or their movement to surface and/or groundwater. Therefore, an endocrine risk of exposure exists for the water and soil organisms. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 105,112, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10038 [source] Structure,activity relationships for gene activation oestrogenicity: Evaluation of a diverse set of aromatic chemicalsENVIRONMENTAL TOXICOLOGY, Issue 1 2002T. Wayne Schultz Abstract Structure,activity relationships for oestrogenicity were developed based on 120 aromatic chemicals evaluated in the Saccharomyces cerevisiae -based Lac -Z reporter assay. Relative gene activation was compared to 17,-estradiol and varied over eight orders of magnitude. Analysis of the data compared to 17,-estradiol identified three structural criteria that were related to xenoestrogen activity and potency: (1) the hydrogen-bonding ability of the phenolic ring mimicking the A-ring, (2) a hydrophobic centre similar in size and shape to the B- and C-rings, and (3) a hydrogen-bond donor mimicking the 17,-hydroxyl moiety of the D-ring, especially with an oxygen-to-oxygen distance similar to that between the 3- and 17,-hydroxyl groups of 17,-estradiol. Binding data were segregated into activity clusters including strong, moderate, weak, and detectable gene expression, and those compounds that were inactive. The hydrogen-bonding ability of hydroxy group in the 3-position on 17,-estradiol was observed to be essential for gene activation. Compounds with a 4-hydroxyl substituted benzene ring and a hydrophobic moiety of size and shape equivalent to the B-ring of 17,-estradiol were generally observed to be weakly active compounds. Moderately active compounds have a 4-hydroxyl substituted benzene ring with a hydrophobic moiety equivalent in size and shape to the B- and C-ring of 17,-estradiol, or have a high hydrogen-bond donor capacity owing to the presence of halogens on a nonphenolic ring. Strongly active compounds, similar to 4,4,-diethylethylene bisphenol (DES), possess the same hydrophobic ring structure as described for moderately active compounds and an additional hydroxyl group with an oxygen-to-oxygen distance close to that exhibited by the 3- and 17-hydroxyl groups of 17,-estradiol. © 2002 by Wiley Periodicals, Inc. Environ Toxicol 17: 14,23, 2002 [source] Fate of estrogens and xenoestrogens in four sewage treatment plants with different technologies,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2008Guang-Guo Ying Abstract The fate and removal of the estrogens 17,-estradiol (E2), estrone (E1), and 17,-ethynylestradiol (EE2) and of the xenoestrogens bisphenol A (BPA), 4- tert -octylphenol (4- t -OP), 4-nonylphenol (4-NP), and nonylphenol mono- and diethoxylate (NPEO1 and NPEO2, respectively) were investigated in four South Australian sewage treatment plants (STPs; plants A,D) with different treatment technologies. The concentrations in the effluent from the two-year survey were similar to those reported in other studies. In the effluent, 4-NP, NPEO1, and NPEO2 had total concentrations up to 8 ,g/L, which were much higher than those of BPA and 4-t-OP. Estrone had the highest concentrations among the three estrogens, ranging between 13.3 and 39.3 ng/L, whereas the concentrations for E2 and EE2 varied between 1.0 and 4.2 ng/L and between 0.1 and 1.3 ng/L, respectively. The removal rates for the estrogens and xenoestrogens were variable but consistent with the plant performance parameters (biochemical oxygen demand, suspended solids, and ammonia). Considering all the estrogenic compounds analyzed in the present study, plant D, with a series of anaerobic and aerobic lagoons, was the least efficient of the four STPs in the removal of these compounds. The removal rates for 4-NP, NPEO1, and NPEO2 within the plants were 92% for plant A, with conventional activated sludge treatment; 80% for plant B, with two oxidation ditches; 70% for plant C, with three bioreactors; and 64% for plant D, with 10 lagoons in series. Comparatively, the removal of estrogens was lower, with rates ranging between 47 and 68% for E2 at the four plants. Both E1 and EE2 were more persistent during treatment, especially in plants C and D. [source] Bioluminescence inhibition assays for toxicity screening of wood extractives and biocides in paper mill process watersENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2004Anna Rigol Abstract The risk associated with wood extractives, biocides, and other additives in pulp and paper mill effluents was evaluated by performing a characterization of process waters and effluents in terms of toxicity and chemical analysis. The individual toxicity of 10 resin acids, two unsaturated fatty acids, and three biocides was estimated by measuring the bioluminescence inhibition with a ToxAlert® 100 system. Median effective concentration values (EC50) of 4.3 to 17.9, 1.2 to 1.5, and 0.022 to 0.50 mg/L were obtained, respectively. Mixtures of these three families of compounds showed antagonistic effects. Chemical analysis of process waters was performed by liquid chromatography-and gas chromatography-mass spectrometry. Biocides such as 2-(thiocyanome-thylthio)-benzotiazole (TCMTB) (EC50 = 0.022 mg/L) and 2,2-dibromo-3-nitrilpropionamide (DBNPA) (EC50 = 0.50 mg/L) were the most toxic compounds tested and were detected at concentrations of 16 and 59 ,g/L, respectively, in a closed-circuit recycling paper mill. Process waters from kraft pulp mills, printing paper mills, and packing board paper mills showed the highest concentration of resin acids (up to 400 ,g/L) and accounted for inhibition percentages up to 100%. Detergent degradation products such as nonylphenol (NP) and octylphenol (OP) and the plasticizer bisphenol A (BPA) were also detected in the waters at levels of 0.6 to 10.6, 0.3 to 1.4, and 0.7 to 187 ,g/L, respectively. However, once these waters were biologically treated, the concentration of detected organic compounds diminished and the toxicity decreased in most cases to values of inhibition lower than 20%. [source] Estrogenic compounds affect development of harpacticoid copepod Tigriopus japonicusENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2003Helen S. Marcial Abstract The aim of this investigation was to evaluate the impact of estrogenic compounds onthe harpacticoid copepod Tigriopus japonicus after continuous exposure to environmentally relevant concentrations. Natural estrogen (17,-estradiol), three known estrogenic compounds in vertebrates (bisphenol A, 4-nonylphenol, p - t -octylphenol), and an invertebrate molting hormone (20-hydroxyecdysone) were tested for their effects on development and reproductive characters in two successive generations of T. japonicus. Less than 24-h-old nauplii (parentals) were exposed to four sublethal concentrations of these compounds for 21 d at 25°C. The first brood of nauplii (F1) produced was monitored further under the same culture conditions and exposures to test compounds. Results showed that all estrogenic compounds affected development (both in number of days to reach copepodid stage and sexual maturity) in the parental generation. Similar effects were apparent in the F1; however, fecundity, sex ratio, and survival were not significantly affected, even at concentrations as high as 10 ,g/L (nominal concentration). The invertebrate molting hormone 20-hyroxyecdysone had no detectable effect on any of the endpoints tested but gave the lowest 48-h 50% lethal concentration (LC50) value. The results suggest that endocrine disruption could occur in copepods following exposure to environmentally relevant concentrations of estrogenic compounds, especially if they are exposed starting from embryonic development. [source] Development of a fish reporter gene system for the assessment of estrogenic compounds and sewage treatment plant effluentsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2002Gabriele E. Ackermann Abstract This study reports on the development and application of a fish-specific estrogen-responsive reporter gene assay. The assay is based on the rainbow trout (Oncorhynchus mykiss) gonad cell line RTG-2 in which an acute estrogenic response is created by cotransfecting cultures with an expression vector containing rainbow trout estrogen receptor a complementary DNA (rtER, cDNA) in the presence of an estrogen-dependent reporter plasmid and an estrogen receptor (ER) agonist. In a further approach, RTG-2 cells were stably transfected with the rtER, cDNA expression vector, and clones responsive to 17,-estradiol (E2) were selected. The estrogenic activity of E2, 17,-ethinylestradiol, 4-nonylphenol, nonylphenoxy acetic acid, 4- tert -octylphenol, bisphenol A, o,p,-DDT, p,p,-DDT, o,p,-2,2-bis(chlorophenyl)-1,1-dichloroethylene (o,p,-DDE), p,p,-DDE, o,p,-2,2-bis(chlorophenyl)-1,1-di-chloroethane (o,p,-DDD), p,p,-DDD, and p,p,-2,2-bis(chlorophenyl)acetic acid (p,p,-DDA) was assessed at increasing concentrations. All compounds except o,p,-DDT, p,p,-DDE, and p,p,-DDA showed logistic dose-response curves, which allowed the calculation of lowest-observed-effect concentrations and the concentrations at which half-maximal reporter gene activities were reached. To check whether estrogen-responsive RTG-2 cells may be used to detect the estrogenic activity of environmental samples, an extract from a sewage treatment plant (STP) effluent was assessed and found to have estrogenic activity corresponding to the transcriptional activity elicited by 0.05 nM of E2. Dose-response curves of nonylphenol, octylphenol, bisphenol A, and o,p,-DDD revealed that the RTG-2 reporter gene assay is more sensitive for these compounds when compared to transfection systems recombinant for mammalian ERs. These differences may have an effect on the calculation of E2 equivalents when estrogenic mixtures of known constitution, or environmental samples, such as STP effluents, are assessed. [source] Effects of bisphenol A and tetrabromobisphenol A on sex organ development in quail and chicken embryosENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Cecilia Berg Abstract The plastic monomere bisphenol A (BPA) and the flame retardant tetrabromobisphenol A (TBBPA) were examined for estrogen-like developmental effects on the reproductive organs in avian embryos. The synthetic estrogen diethylstilbestrol (DES) was used as a positive control. The test compounds were injected into the yolk of quail and chicken eggs early during incubation and the embryos were examined 2 d before anticipated hatching. At 200 ,g/g egg, BPA induced Müllerian duct (embryonic oviduct) malformation in female quail embryos and feminization of the left testis (ovotestis) in male chicken embryos. The estrogenic potency of BPA compared with DES was species and endpoint specific. Müllerian duct malformation was the most sensitive endpoint in quail embryos, whereas ovotestis formation was the most sensitive response in chicken embryos. Tetrabromobisphenol A caused high embryo mortality at 45 ,g/g egg in both species, but no estrogen-like effects were observed. Bisphenol A caused mortality only in chicken embryos at 67 and 200 ,g/g egg. To our knowledge, this is the first report on estrogen-like or embryolethal effects of BPA and TBBPA in birds. [source] Substances with estrogenic activity in effluents of sewage treatment plants in southwestern Germany.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2001Abstract A gas chromatography/mass spectrometry method for the simultaneous quantitative determination of natural and synthetic estrogens (17,-estradiol, estrone, 17,-ethinylestradiol, and mestranol), phytoestrogens (genistein and ,-sitosterol), and xenoestrogens (benzyl butyl phthalate, dibutyl phthalate, bisphenol A, 4-nonylphenol [NP], 4-nonylphenoxyacetic acid [NP1EC], 4-nonyl-phenol diethoxylate [NP2EO], and ,-endosulfan) in effluents of sewage treatment plants (STPs) was developed. Identification and quantification were carried out with the standard addition method using analyte-specific and, in some cases, deuterium-labeled internal standards. The effluents of 18 STPs were investigated. Apart from ,-endosulfan and mestranol, all selected substances were detected in the majority of samples. The median concentrations of steroidal estrogens were between 0.4 ng/L (17,-ethiny-lestradiol) and 1.6 ng/L (17,-estradiol). The metabolites of the nonylphenol polyethoxylates, NP, NP1EC, and NP2EO were found in concentrations ranging from the upper-ng/L-range (NP) to the lower-,g/L range (NP1EC). For all substances except mestranol and ,-endosulfan, median values were calculated and compared to the results of other investigations in Europe and the United States. Possible dependencies of measured concentrations on the geographical location, the capacity, the influent composition, and the technical fitting of the STPs are discussed. [source] Toxicokinetics of waterborne bisphenol a in landlocked salmon (Salmo salar m. Sebago) eggs at various temperaturesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2001Jani O. Honkanen Abstract Eye-pigmented eggs of landlocked salmon were exposed to waterbone [14C]-labeled bisphenol A at four temperatures (2, 6, 8, and 12°C). Both in accumulation and depuration experiments, the eggs were exposed to a bisphenol A concentration of 1 ,g/L for 196 h. In the depuration experiment, the exposed eggs were placed into clean water for 96 h. At each sampling time, the eggs were dissected into three parts (eggshell, embryo, and yolk sac), and all of these parts were weighed and analyzed separately in a liquid scintillation counter. The results show that waterborne bisphenol A accumulates in developing salmon eggs. Accumulation of bisphenol A showed a clear trend both in whole eggs and in dissected parts: the higher the temperature, the higher the uptake rate constant and the concentration of bisphenol A. Steady state was reached only in the embryos at the lowest temperature; in other cases, accumulation was linear. Depuration was significant only in the embryos at 2 and 6°C. As the accumulation and the depuration results show, the elimination of bisphenol A was evidently more significant at lower temperatures. [source] Effects of nonylphenol, bisphenol a, and their mixture on the viviparous swordtail fish (Xiphophorus helleri)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2001Hyeong-Il Kwak Abstract A number of fish species have been used for studies on endocrine disrupting chemicals (EDCs). However, despite the widespread use of oviparous fish, relatively little attention has been given to viviparous species. This study investigated the effects of EDCs in a viviparous fish and examined the possible usefulness of the fish as an alternative model for the studies on EDCs. Swordtails (Xiphophorus helleri) were exposed to nonylphenol (NP), bisphenol A (BPA), and their mixture. Both short-term (3-d) and relatively long-term (60-d) exposures were carried out using adult male and 30-d-old juvenile fish, respectively. Following the short-term exposure, both NP and BPA caused vitellogenin mRNA expression. Flow cytometric analysis and terminal deox-ynucleotidyl transferase assay on the testes of treated fish indicated reproductive damage. Histopathological analysis found degenerative and necrotic cells in seminiferous tubules following the exposure to 100 ppb NP. The testes with lesions were also associated with highly suppressed spermatogenesis. Following the long-term exposure, both NP and BPA exposures significantly affected the growth of swordtails. In all cases, the results showed that the mixture was always more potent than a single chemical and that swordtail fish can be a useful model for the study of endocrine disruptors. [source] Enhanced Photocatalytic Activity using Layer-by-Layer Electrospun Constructs for Water RemediationADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Jung Ah Lee Abstract Endocrine disruptors such as bisphenol A (BPA) are environmental pollutants that interfere with the body's endocrine system because of their structural similarity to natural and synthetic hormones. Due to their strong oxidizing potential to decompose such organic pollutants, colloidal metal oxide photocatalysts have attracted increasing attention for water detoxification. However, achieving both long-term physical stability and high efficiency simultaneously with such photocatalytic systems poses many challenges. Here a layer-by-layer (LbL) deposition approach is reported for immobilizing TiO2 nanoparticles (NPs) on a porous support while maintaining a high catalytic efficiency for photochemical decomposition of BPA. Anatase TiO2 NPs ,7,nm in diameter self-assemble in consecutive layers with positively charged polyhedral oligomeric silsesquioxanes on a high surface area, porous electrospun polymer fiber mesh. The TiO2 LbL nanofibers decompose approximately 2.2,mg BPA per mg of TiO2 in 40,h of illumination (AM 1.5G illumination), maintaining first-order kinetics with a rate constant (k) of 0.15,h,1 for over 40,h. Although the colloidal TiO2 NPs initially show significantly higher photocatalytic activity (k,,,0.84,h,1), the rate constant drops to k,,,0.07,h,1 after 4,h of operation, seemingly due to particle agglomeration. In the BPA solution treated with the multilayered TiO2 nanofibers for 40,h, the estrogenic activity, based on human breast cancer cell proliferation, is significantly lower than that in the BPA solution treated with colloidal TiO2 NPs under the same conditions. This study demonstrates that water-based, electrostatic LbL deposition effectively immobilizes and stabilizes TiO2 NPs on electrospun polymer nanofibers for efficient extended photochemical water remediation. [source] Effects of possible endocrine disruptors on MyD88-independent TLR4 signalingFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2008Takahiro Ohnishi Abstract Endocrine disrupting chemicals (EDCs) may potentially worsen infectious diseases because EDCs disturb human immune function by interfering with endocrine balance. To evaluate the influence of EDCs on the innate immune function of macrophages, we investigated the effects of 37 possible EDCs on lipopolysaccharide-induced activation of the IFN-, promoter. Alachlor, atrazine, benomyl, bisphenol A, carbaryl, diethyl phthalate, dipropyl phthalate, kelthane, kepone, malathion, methoxychlor, octachlorostyrene, pentachlorophenol, nonyl phenol, p -octylphenol, simazine and ziram all inhibited the activation. Kepone and ziram showed strong inhibitory effects. Aldicarb, amitrole, benzophenone, butyl benzyl phthalate, 2,4-dichlorophenoxy acetic acid, dibutyl phthalate, 2,4-dichlorophenol, dicyclohexyl phthalate, diethylhexyl adipate, diethylhexyl phthalate, dihexyl phthalate, di- n -pentyl phthalate, methomyl, metribuzin, nitrofen, 4-nitrotoluene, permethrin, trifluralin, 2,4,5-trichlorophenoxyacetic acid and vinclozolin had no significant effects at 100 ,M. These results indicate that some agrochemicals and resin-related chemicals may potentially inhibit macrophage function, which suggests that endocrine disruptors may influence the development of infectious diseases. [source] Enhanced interleukin-4 production in CD4+ T cells and elevated immunoglobulin E levels in antigen-primed mice by bisphenol A and nonylphenol, endocrine disruptors: involvement of nuclear factor-AT and Ca2+IMMUNOLOGY, Issue 1 2003Mee H. Lee Summary Bisphenol A (BPA) and p -nonylphenol (NP) are representative endocrine disruptors (EDs) that may have adverse effects on human health. The influence of these compounds on allergic immune responses remains unclear. In this study, we have examined the effects of BPA and NP on production of interleukin-4 (IL-4), a pro-inflammatory cytokine closely associated with allergic immune responses. Both BPA and NP significantly enhanced IL-4 production in keyhole limpet haemocyanin (KLH)-primed CD4+ T cells in a concentration-dependent manner. Treatment with BPA or NP in vivo resulted in significant increase of IL-4 production in CD4+ T cells and of antigen-specific immunoglobulin E (IgE) levels in the sera of KLH-primed mice. Furthermore, BPA and NP enhanced the activation of IL-4 gene promoter in EL4 T cells transiently transfected with IL-4 promoter/reporter constructs, and the enhancing effect mapped to a region in the IL-4 promoter containing binding sites for nuclear factor (NF)-AT. Activation of T lymphocytes by phorbol 12-myristate 13-acetate/ionomycin resulted in markedly enhanced binding activities to the NF-AT site, which significantly increased upon addition of BPA or NP, as demonstrated by the electrophoretic mobility shift assay, indicating that the transcription factor NF-AT was involved in the enhancing effect of BPA and NP on IL-4 production. The enhancement of IL-4 production by BPA or NP was significantly reduced by nitrendipine, a blocker of Ca2+ influx, and by FK506, a calcineurin inhibitor. FK506 inhibited the NF-AT,DNA binding activity and IL-4 gene promoter activity enhanced by BPA or NP. These results represent the first report describing possible enhancement of allergic response by EDs through increasing IL-4 production in CD4+ T cells and antigen-specific IgE levels in the sera via the stimulation of Ca2+/calcineurin-dependent NF-AT activation. [source] Combined exposures to anti-androgenic chemicals: steps towards cumulative risk assessmentINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2010A. Kortenkamp Summary There is widespread exposure to anti-androgens, a group of chemicals able to disrupt androgen action in foetal life, with irreversible de-masculinizing consequences. Substances of concern include certain phthalates, pesticides and chemicals used in cosmetics and personal care products. Although people come into contact with several anti-androgens, chemicals risk assessment normally does not take account of the effects of combined exposures. However, a disregard for combination effects may lead to underestimations of risks and for this reason, we have assessed the feasibility of conducting cumulative risk assessment, where the focus is on considering the effects of exposure to multiple chemicals, via multiple routes and pathways. Following recent recommendations by the US National Research Council, we have, for the first time, included phthalates and other anti-androgenic chemicals, a total of 15 substances. On the basis of exposure estimates for the individual chemicals and reference doses for anti-androgenicity, we have used the hazard index approach. We show that the cumulative risks from anti-androgen exposures exceed acceptable levels for people on the upper end of exposure levels. The value obtained for median exposures to the 15 substances can be judged tolerable. However, significant knowledge gaps exist that prevent us from arriving at definitive conclusions. Of greatest concern is an absence of appropriate in vivo toxicity data about large numbers of in vitro androgen receptor antagonists. Knowledge about the effect profiles of these chemicals will lead to higher risk estimates. Our analysis suggests that risk reductions can be achieved by limiting exposures to the plasticizer diethyl hexyl phthalate, the cosmetic ingredients butyl- and propyl paraben, the pesticides vinclozolin, prochloraz and procymidone and bisphenol A. [source] Use of chitosan for removal of bisphenol A and bisphenol derivatives through tyrosinase-catalyzed quinone oxidationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2010Mizuho Suzuki Abstract In this study, the availability of chitosan was systematically investigated for removal of bisphenol A (BPA, 2,2-bis(hydroxyphenyl)propane) through the tyrosinase-catalyzed quinone oxidation and subsequent quinone adsorption on chitosan beads. In particular, the process parameters, such as the hydrogen peroxide (H2O2)-to-BPA ratio, pH value, temperature, and tyrosinase dose, were discussed in detail for the enzymatic quinone oxidation. Tyrosinase-catalyzed quinone oxidation of BPA was effectively enhanced by adding H2O2 and the optimum conditions for BPA at 0.3 mM were determined to be pH 7.0 and 40°C in the presence of H2O2 at 0.3 mM ([H2O2]/[BPA] = 1.0). Removal of BPA from aqueous solutions was accomplished by adsorption of enzymatically generated quinone derivatives on chitosan beads. The use of chitosan in the form of beads was found to be more effective because heterogeneous removal of BPA with chitosan beads was much faster than homogeneous removal of BPA with chitosan solutions, and the removal efficiency was enhanced by increasing the amount of chitosan beads dispersed in the BPA solutions and BPA was completely removed by quinone adsorption in the presence of chitosan beads more than 0.10 cm3/cm3. In addition, a variety of bisphenol derivatives were completely or effectively removed by the procedure constructed in this study, although the enzyme dose or the amount of chitosan beads was further increased as necessary for some of the bisphenol derivatives used. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Synthesis and characterization of a cured epoxy resin with a benzoxazine monomer containing allyl groupsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010Shiao-Wei Kuo Abstract Vinyl-terminated benzoxazine (VB-a), which can be polymerized through ring-opening polymerization, was synthesized through the Mannich condensation of bisphenol A, formaldehyde, and allylamine. This VB-a monomer was then blended with epoxy resin and then concurrently thermally cured to form an epoxy/VB-a copolymer network. To understand the curing kinetics of this epoxy/VB-a copolymer, dynamic differential scanning calorimetry measurements were performed by the Kissinger and Flynn,Wall,Ozawa methods. Fourier transform infrared (FTIR) analyses revealed the presence of thermal curing reactions and hydrogen-bonding interactions of the epoxy/VB-a copolymers. Meanwhile, a significant enhancement of the ring-opening and allyl polymerizations of the epoxy was observed. For these interpenetrating polymer networks, dynamic mechanical analysis and thermogravimetric analysis results indicate that the thermal properties increased with increasing VB-a content in the epoxy/VB-a copolymers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] | |||||||||||||||||||