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Sample records for biodegradation du 2-ethylhexyl

  1. Synergistic effect using vermiculite as media with a bacterial biofilm of Arthrobacter sp. for biodegradation of di-(2-ethylhexyl) phthalate.

    PubMed

    Wen, Zhi-Dan; Wu, Wei-Min; Ren, Nan-Qi; Gao, Da-Wen

    2016-03-05

    Vermiculite is one of matrix material used for constructed wetland (CW) for the treatment of municipal wastewater. Arthrobacter sp. strain C21 (CGMCC No. 7671), isolated from a constructed wetland receiving municipal wastewater, forms biofilm on the surface of vermiculite. Di-(2-ethylhexyl) phthalate (DEHP), a typical phthalate pollutant in environment, can be degraded by the biofilm of strain C21 formed on vermiculite. Results of laboratory studies indicated that DEHP was removed from aqueous phase via biodegradation, adsorption by vermiculite, and adsorption by biofilm biomass. Synergistic effect of these three reactions enhanced the overall DEHP removal efficiency. During a batch incubation test with vermiculite and the cell suspension, bacterial adhesion to the media surface occurred within 5h and the phthalate esters (PEs) removal was due to both biodegradation and vermiculite adsorption. As the biofilm developed on surface of vermiculite (5-36 h), biodegradation became the predominance for PEs removal. As mature biofilm was formed (36-54 h), the adsorption of PEs by biofilm biomass became a main driving force for the removal of PEs from aqueous phase. The content of extracellular polymers (EPS) of the biofilm and DEHP removal performance showed a significant positive correlation (rp>0.86).

  2. Effect of ultrasonication and Fenton oxidation on biodegradation of bis(2-ethylhexyl) phthalate (DEHP) in wastewater sludge.

    PubMed

    Pham, T T H; Tyagi, R D; Brar, S K; Surampalli, R Y

    2011-02-01

    The presence of bis(2-ethylhexyl) phthalate (DEHP) and its metabolites, i.e. 2-ethylhexanol, 2-ethylhexanal, and 2-ethylhexanoic acid in wastewater sludge (WWS) were investigated during aerobic digestion and Bacillus thuringiensis (Bt)-based fermentation of WWS. Ultrasonication and Fenton oxidation pre-treatment was applied to improve biodegradability of WWS and bioavailability of the target compounds for digestion and fermentation. DEHP and 2-ethylhexanoic acid were observed at higher concentration, meanwhile 2-ethylhexanol and 2-ethylhexanal were observed at lower concentration in WWS. After 20-day aerobic digestion, DEHP removal was 72%, 89%, and 85%, and 2-ethylhexanoic acid removal was 71%, 84%, 79%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges. Bt was found to degrade DEHP, leading to DEHP removal of 21%, 40%, and 30%, respectively for raw, ultrasonicated, and Fenton-oxidized sludges in the fermentation. The results suggested that aerobic stabilization and Bt-based fermentation can remove the phthalates, and pre-treatment of WWS was also effective in improvement of DEHP biodegradation. Hence, Bt-based biopesticide production from WWS can be applied safely when taking into consideration the phthalate contaminants.

  3. Biodegradation of 2-Ethylhexyl Nitrate by Mycobacterium austroafricanum IFP 2173▿

    PubMed Central

    Nicolau, Elodie; Kerhoas, Lucien; Lettere, Martine; Jouanneau, Yves; Marchal, Rémy

    2008-01-01

    2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel that is used to increase the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected from among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous-phase liquid, suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation, as well as organic-carbon measurement, indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by gas chromatography/mass spectrometry and was provisionally identified as 4-ethyldihydrofuran-2(3H)-one by liquid chromatography-tandem mass spectrometry analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolized further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability. PMID:18723659

  4. Di(2-ethylhexyl)adipate

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) adipate ; CASRN 103 - 23 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  5. Di (2-ethylhexyl)phthalate (DEHP)

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) phthalate ( DEHP ) ; CASRN 117 - 81 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessme

  6. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN P-07...

  7. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN P-07...

  8. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN P-07...

  9. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN...

  10. 40 CFR 721.10131 - Isononanamide, N-(2-ethylhexyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isononanamide, N-(2-ethylhexyl)-. 721... Substances § 721.10131 Isononanamide, N-(2-ethylhexyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as isononanamide, N-(2-ethylhexyl)- (PMN P-07...

  11. Physical proprieties of low viscosity estolide 2-ethylhexyl esters

    USDA-ARS?s Scientific Manuscript database

    Acetic- and butyric-capped oleic estolide 2-ethylhexyl (2-EH) esters were synthesized in a perchloric acid catalyzed (0.05 equiv) one-pot process from industrial 90% oleic acid and either acetic or butyric fatty acids at two different ratios. This was directly followed by the esterification process ...

  12. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from the...

  13. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from the...

  14. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from the...

  15. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from the...

  16. 40 CFR 180.1274 - Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Tris (2-ethylhexyl) phosphate... RESIDUES IN FOOD Exemptions From Tolerances § 180.1274 Tris (2-ethylhexyl) phosphate; exemption from the requirement of a tolerance. Tris (2-ethylhexyl) phosphate (TEHP, CAS Reg. No. 78-42-2) is exempt from the...

  17. Estimation of human percutaneous uptake for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (TBB) and bis(2-ethylhexyl) tetrabromophthalate (TBPH) using the parallelogram method

    EPA Science Inventory

    2-ethylhexyl- tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromobenzoate (TBPH) are novel brominated flame retardants (FRs). TBPH is used as a plasticizer or with TBB in polyurethane foam FRs. TBB & TBPH have been detected in both indoor and outdoor environmental sampl...

  18. Estimation of human percutaneous uptake for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (TBB) and bis(2-ethylhexyl) tetrabromophthalate (TBPH) using the parallelogram method

    EPA Science Inventory

    2-ethylhexyl- tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromobenzoate (TBPH) are novel brominated flame retardants (FRs). TBPH is used as a plasticizer or with TBB in polyurethane foam FRs. TBB & TBPH have been detected in both indoor and outdoor environmental sampl...

  19. Epigenetic Effects of Di(2-ethylhexyl) Phthalate | Science ...

    EPA Pesticide Factsheets

    Epidemiological and laboratory investigations suggest that, in addition to genetic changes, environmental pollutants can affect human health through altering epigenetic mechanisms including DNA methylation, histone modification, and microRNA expression. There is evidence in animals and humans of an association of di(2-ethylhexyl) phthalate (DEHP) exposure and developmental and reproductive toxicity. Multiple lines of evidence from in vitro and in vivo models have established that epigenetic changes occur upon in utero exposures to several phthalates including DEHP. This poster will be presented at the 45th Annual Meeting of the Environmental Mutagenesis and Genomics Society (EMGS).

  20. Epigenetic Effects of Di(2-ethylhexyl) Phthalate | Science ...

    EPA Pesticide Factsheets

    Epidemiological and laboratory investigations suggest that, in addition to genetic changes, environmental pollutants can affect human health through altering epigenetic mechanisms including DNA methylation, histone modification, and microRNA expression. There is evidence in animals and humans of an association of di(2-ethylhexyl) phthalate (DEHP) exposure and developmental and reproductive toxicity. Multiple lines of evidence from in vitro and in vivo models have established that epigenetic changes occur upon in utero exposures to several phthalates including DEHP. This poster will be presented at the 45th Annual Meeting of the Environmental Mutagenesis and Genomics Society (EMGS).

  1. Biotransformation of di(2-ethylhexyl)phthalate by rainbow trout

    SciTech Connect

    Barron, M.G.; Hayton, W.L.

    1995-05-01

    The biotransformation of di(2-ethylhexyl)phthalate (DEHP) was studied in rainbow trout (Oncorhynchus mykiss) following intravascular administration. Methyl-esterified metabolites were identified using rodent-derived standards and non-linear gradient elution HPLC; metabolites were confirmed by gas chromatography. Similarities between the biotransformation of DEHP by rainbow trout and mammalian species included (a) mono-ethylhexyl phthalate (MEHP) appeared to be the obligatory first step in DEHP metabolism; (b) the phthalate ring was not oxidized; (c) phthalic acid was a minor metabolite; and (d) several metabolites contained multiple oxidations of the 2-ethylhexyl moiety of MEHP. No metabolites unique to rainbow trout were identified. However, fewer oxidized metabolites were identified in rainbow trout than in mammalian species, possibly due to limited mitochondrial metabolism of MEHP in rainbow trout. The amount of biliary MEHP glucuronide after intravascular administration of DEHP was substantially less than reported in rainbow trout exposed to DEHP via the water. Results confirmed that DEHP metabolism in rainbow trout proceeds by initial rapid formation of MEHP, followed by excretion or extensive oxidation by microsomal P450.

  2. Bis-(2-ethylhexyl) phthalate, an ubiquitous environmental contaminant

    SciTech Connect

    Griffiths, W.C.; Camara, P.; Lerner, K.S.

    1985-03-01

    Bis-(2-ethylhexyl) phthalate (DEHP) is the most commonly used plasticizing agent for the widely used plastic polyvinylchloride (PVC). Consequently, this compound is found everywhere in the environment of civilization, where it is in frequent contact with every person. Blood storage bags and tubing, food wrappers, and many children's toys contain appreciable amounts of DEHP. Given this frequency of exposure, the toxic potential of the compound has become a major concern. Many workers have demonstrated its exceedingly low acute toxicity, while results from chronic exposure studies have been mixed. However, in 1982 the National Toxicology Program reported a significantly increased incidence of hepatocellular carcinoma in rats and mice exposed to high doses of DEHP over a period of two years. The significance of these studies remains in question. Bis-(2-ethylhexyl) phthalate is metabolized extensively by mammals, but reports of the direct study of the toxic effects of its metabolites are few. Efficient methods for analysis of biological samples for DEHP are available, but they are complicated by the constant presence of this compound as a contaminant.

  3. Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro

    SciTech Connect

    Gupta, Rupesh K.; Singh, Jeffery M.; Leslie, Tracie C.; Meachum, Sharon; Flaws, Jodi A.; Yao, Humphrey H-C

    2010-01-15

    Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 mug/ml) and MEHP (0.1-10 mug/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin-dependant-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators.

  4. Contemporary carbon content of bis (2-ethylhexyl) phthalate in butter.

    PubMed

    Tong, T; Ondov, J M; Buchholz, B A; VanDerveer, M C

    2016-01-01

    The fraction of naturally produced bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid-liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈ 250 μg extracts of DEHP with carbon purity ranging from 92.5 ± 1.2% (n = 3, 1σ) to 97.1 ± 0.8% (n = 3, 1σ) as measured with gas chromatography mass spectrometry (GC-MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16 ± 0.12 (n = 5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S.

  5. The carcinogenicity of di(2-ethylhexyl) phthalate (DEHP) in perspective.

    PubMed

    Kluwe, W M; Haseman, J K; Huff, J E

    1983-07-01

    The commonly used plasticizer di(2-ethylhexyl) phthalate (DEHP) was recently tested for chronic toxic potential by incorporation into the diet of rats and mice for approximately 2 yr. Upon reviewing the test results, the sponsoring organization concluded that DEHP was carcinogenic to the rats and mice, as indicated by increased occurrences of liver tumors in the DEHP-exposed animals in comparison to controls. Another group has disagreed with this conclusion, however, citing perceived methodological deficiencies and improper interpretations in the study, and has also suggested that rodents may not be adequate models of human response to DEHP. This communication compares the conduct of the DEHP bioassay favorably with state-of-the-art procedures in animal carcinogenicity testing and documents approval of the study interpretations by several independent peer review groups. The carcinogenic potential of DEHP is placed in perspective by evaluating the evidence for DEHP-induced tumors in rodent species in light of dose response relationships, other biochemical and toxicological effects of DEHP, and its comparative metabolism and disposition in rodent and primate species. A composite analysis of the currently available information indicates that DEHP has been shown to be carcinogenic to rodents in a valid chronic test, indicating that it should be considered as a potential carcinogen in humans, as well. Further experimental inquiry will be required, however, to accurately assess the potential health risks posed to humans by exposure to small amounts of this plasticizer.

  6. Critical cleaning agents for Di-2-ethylhexyl sebacate.

    SciTech Connect

    Hartley, Mya; Archuleta, Kim M.

    2013-08-01

    It is required that Di-2-ethylhexyl Sebacate oil, also commonly known as Dioctyl Sebacate oil, be thoroughly removed from certain metals, in this case stainless steel parts with narrow, enclosed spaces. Dioctyl Sebacate oil is a synthetic oil with a low compressibility. As such, it is ideally used for high pressure calibrations. The current method to remove the Dioctyl Sebacate from stainless steel parts with narrow, enclosed spaces is a labor-intensive, multi-step process, including a detergent clean, a deionized (DI) water rinse, and several solvent rinses, to achieve a nonvolatile residue of 0.04 mg per 50 mL rinse effluent. This study was undertaken to determine a superior detergent/solvent cleaning method for the oil to reduce cleaning time and/or the amount of detergent/solvent used. It was determined that while some detergent clean the oil off the metal better than the current procedure, using only solvents obtained the best result. In addition, it can be inferred, based on elevated temperature test results, that raising the temperature of the oil-contaminated stainless steel parts to approximately 50ÀC will provide for improved cleaning efficacy.

  7. Contemporary Carbon Content of Bis (2-ethylhexyl) Phthalate in Butter

    PubMed Central

    Tong, T.; Ondov, J. M.; Buchholz, B. A.; VanDerveer, M. C.

    2016-01-01

    The fraction of naturally produced Bis (2-ethylhexyl) phthalate (DEHP), a ubiquitous plasticizer known to contaminate packaged foods, was determined for each of five 1.10 kg samples of unsalted market butter by accelerator mass spectrometry (AMS). After extraction and concentration enrichment with liquid-liquid extraction, flash column chromatography, and preparative-scale high performance liquid chromatography, each sample provided ≈250 µg extracts of DEHP with carbon purity ranging from 92.5±1.2% (n=3, 1σ) to 97.1±0.8% (n=3, 1σ) as measured with gas chromatography mass spectrometry (GC-MS). After corrections for method blank DEHP, co-eluting compounds, and unidentified carbon, the mean fraction of naturally produced DEHP in butter was determined to be 0.16±0.12 (n=5, 1σ). To our knowledge, this is the first report of the contemporary fraction of DEHP isolated from market butter in the U.S. PMID:26213077

  8. Extraction of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester in the presence of diethylenetriaminepentaacetic acid in aqueous phase

    SciTech Connect

    Kubota, Fukiko; Goto, Masahiro; Nakashio, Fumiyuki

    1993-07-01

    The extraction equilibria of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (commercial name, PC-88A, henceforth abbreviated as HR) dissolved in n-heptane were measured at 303 K. It was found that rare earth metals are extracted with the dimer of the extractant, (HR){sub 2}, as follows. M{sub aq}{sup 3+} + 3(HR){sub 2 org} MR{sub 3} {center_dot} 3HR{sub org} + 3H{sub aq}{sup +} The extraction equilibrium constants of metals were obtained and compared with the extraction equilibrium constants obtained by di(2-ethylhexyl)phosphoric acid (henceforth DZEHPA). Furthermore, the extraction equilibria of rare earth metals with PC-88A in the presence of diethylenetriaminepentaacetic acid (henceforth DTPA) in an aqueous phase were also measured to discuss the effect of DTPA on the extraction of rare earth metals. 13 refs., 8 figs., 2 tabs.

  9. Risk assessment of di(2-ethylhexyl) phthalate in the workplace

    PubMed Central

    2016-01-01

    Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor (“Survey on the work environment”) and by the Ministry of Environment (“Survey on the circulation amount of chemicals”). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be 0.990 mg/m3, as compared to the threshold exposure level of 5 mg/m3. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the

  10. Simultaneous determination of polyvinylchloride plasticizers di(2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate and its degradation products in blood by liquid chromatography-tandem mass spectrometry.

    PubMed

    Eckert, Elisabeth; Müller, Johannes; Göen, Thomas

    2015-09-04

    Di(2-ethylhexyl) phthalate (DEHP) and tri(2-ethylhexyl) trimellitate (TEHTM or TOTM) are common plasticizers that are also largely used for PVC medical devices, e.g. bags and tubing for blood transfusions and infusions. The leachability of medical devices is a well-known situation of increasing toxicological concern. To assess the migration of plasticizers from PVC medical devices into human blood we developed and validated an analytical method for the determination of DEHP and TOTM in combination with the determination of their primary degradation products mono(2-ethylhexyl) phthalate (MEHP), 1,2-di(2-ethylhexyl) trimellitate (1,2-DEHTM) and 2-mono(2-ethylhexyl) trimellitate (2-MEHTM). The presented method involves liquid-liquid extraction of the analytes from the blood followed by the subsequent analytical separation and detection using LC-MS/MS analysis. The validation of the procedure showed a good precision in the range of 1.8 to 5.3%. Mean accuracy ranged from 86% for 1,2-DEHTM to 109% for MEHP. LOQ was found to be 2 to 5μg/L for each of the analytes. Additionally, the method is characterised by its wide linear range up to 2mg/L each for the degradation products of TOTM to 100mg/L for the parent plasticizer DEHP. The presented method promises to be of major advantage for further studies as it allows for the first time the simultaneous determination of DEHP and TOTM in human blood in combination with the analysis of their degradation products that render possible to investigate the leachability of a broad range of PVC medical devices in human blood using only one analytical method.

  11. Toxicogenomic Screening of Replacements for Di(2-Ethylhexyl) Phthalate (DEHP) Using the Immortalized TM4 Sertoli Cell Line

    PubMed Central

    Nardelli, Thomas C.; Erythropel, Hanno C.; Robaire, Bernard

    2015-01-01

    Phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) are being phased out of many consumer products because of their endocrine disrupting properties and their ubiquitous presence in the environment. The concerns raised from the use of phthalates have prompted consumers, government, and industry to find alternative plasticizers that are safe, biodegradable, and have the versatility for multiple commercial applications. We examined the toxicogenomic profile of mono(2-ethylhexyl) phthalate (MEHP, the active metabolite of DEHP), the commercial plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and three recently proposed plasticizers: 1,4-butanediol dibenzoate (BDB), dioctyl succinate (DOS), and dioctyl maleate (DOM), using the immortalized TM4 Sertoli cell line. Results of gene expression studies revealed that DOS and BDB clustered with control samples while MEHP, DINCH and DOM were distributed far away from the control-DOS-BDB cluster, as determined by principle component analysis. While no significant changes in gene expression were found after treatment with BDB and DOS, treatment with MEHP, DINCH and DOM resulted in many differentially expressed genes. MEHP upregulated genes downstream of PPAR and targeted pathways of cholesterol biosynthesis without modulating the expression of PPAR’s themselves. DOM upregulated genes involved in glutathione stress response, DNA repair, and cholesterol biosynthesis. Treatment with DINCH resulted in altered expression of a large number of genes involved in major signal transduction pathways including ERK/MAPK and Rho signalling. These data suggest DOS and BDB may be safer alternatives to DEHP/MEHP than DOM or the commercial alternative DINCH. PMID:26445464

  12. Simultaneous removal of di-(2-ethylhexyl) phthalate and nitrogen in a laboratory-scale pre-denitrification biofilter system.

    PubMed

    Cao, Xiangsheng; Ai, Niyuan; Meng, Xuezheng

    2014-03-01

    This study demonstrated the excellent di-(2-ethylhexyl) phthalate (DEHP) removal performance of a pre-denitrification biofilter system. Experimental results showed that DEHP removal efficiency remained stable while total nitrogen removal efficiency fluctuated with the nitrate recycle ratio changes when the hydraulic loading rate at 1.1m(3)/m(2)h. DEHP removal efficiency increased from 48% to 82% while the hydraulic loading rate increased from 1.1 to 2.2m(3)/m(2)h. DEHP concentration decreased gradually along the wastewater flow direction in the denitrification biofilter and a plug flow model with the reaction order of 5 and the rate constant of 0.54 was obtained. Both the denitrification biofilter and the nitrification biofilter showed similar DEHP removal performance. The overall DEHP removal efficiency of the system was 83.8%, in which biodegradation contributed 72.3%. Biodegradation plays a key role in DEHP removal in the pre-denitrification biofilter system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Extraction kinetics of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester using a hollow fiber membrane extractor

    SciTech Connect

    Kubota, Fukiko; Goto, Masahiro; Nakashio, Fumiyuki; Hano, Tadashi

    1995-03-01

    A kinetic study concerning chemical complexation-based solvent extraction of rare earth metals with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester dissolved as an extractant in n-heptane was carried out using a microporous hydrophobic hollow fiber membrane extractor. The effects of concentration of chemical species in aqueous and organic feed solutions on the apparent permeabilities of metal species for extraction and stripping, respectively, were investigated to clarify the permeation mechanism. From the experimental results it was predicted that the permeation rate is controlled by diffusion of the chemical species in aqueous and organic phases and by interfacial chemical reaction. The experimental data were analyzed by the diffusion model accompanied with an interfacial reaction, taking into account the velocity distributions of the aqueous and organic phases through the inner and outer sides of the hollow fiber.

  14. Dose Reconstruction of Di-2-Ethylhexyl Phthalate Using a Simple Pharmacokinetic Model [Manuscript

    EPA Science Inventory

    Background In 2005, eight adults provided full volumes and times of urine voids during one normal work week. These samples were analyzed for four di-2-ethylhexyl phthalate (DEHP) metabolites. Participants also provided diary information on their diet, driving, and out¬door a...

  15. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and enviro...

  16. Endoplasmic reticulum stress as a novel cellular response to di (2-ethylhexyl) phthalate exposure.

    PubMed

    Peropadre, Ana; Fernández Freire, Paloma; Pérez Martín, José Manuel; Herrero, Óscar; Hazen, María José

    2015-12-25

    Di (2-ethylhexyl) phthalate is a high-production chemical widely used as a plasticizer for polyvinyl chloride products. Due to its ubiquitous presence in environmental compartments and the constant exposure of the general population through ingestion, inhalation, and dermal absorption, this compound has been subjected to extensive in vivo and in vitro toxicological studies. Despite the available information, research on the cytotoxicity of di (2-ethylhexyl) phthalate in mammalian cells is relatively limited.In this paper, an in vitro multi-parametric approach was used to provide further mechanistic data on the toxic activity of this chemical in Vero and HaCaT cells. Our results reveal that a 24 h exposure to di (2-ethylhexyl) phthalate causes, in both cell lines, an inhibition of cell proliferation that was linked to cell cycle delay at the G1 phase. Concomitantly, the tested compound induces mild endoplasmic reticulum stress which leads to an adaptive rather than a pro-apoptotic response in mammalian cells. These findings demonstrate that there are multiple potential cellular targets of di (2-ethylhexyl) phthalate-induced toxicity and the need to develop further experimental studies for the risk assessment of this ubiquitous plasticizer.

  17. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and enviro...

  18. VITELLOGENIN GENE EXPRESSION IN MALE FATHEAD MINNOWS EXPOSED TO DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used extensively in the plastics industry. DEHP has been shown to be ubiquitous in the environment and has been detected in ground and surface waters, sediment sludge and at several Superfund sites. Previous studies using rats ...

  19. MODULATION OF RAT LEYDIG CELL STEROIDOGENIC FUNCTION BY DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Modulation of rat Leydig cell steroidogenic function by di(2-ethylhexyl)phthalate.

    Akingbemi BT, Youker RT, Sottas CM, Ge R, Katz E, Klinefelter GR, Zirkin BR, Hardy MP.

    Center for Biomedical Research, Population Council, New York, New York 10021, USA. benson@popcbr...

  20. Dose Reconstruction of Di-2-Ethylhexyl Phthalate Using a Simple Pharmacokinetic Model [Manuscript

    EPA Science Inventory

    Background In 2005, eight adults provided full volumes and times of urine voids during one normal work week. These samples were analyzed for four di-2-ethylhexyl phthalate (DEHP) metabolites. Participants also provided diary information on their diet, driving, and out¬door a...

  1. VITELLOGENIN GENE EXPRESSION IN MALE FATHEAD MINNOWS EXPOSED TO DI(2-ETHYLHEXYL)PHTHALATE

    EPA Science Inventory

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer used extensively in the plastics industry. DEHP has been shown to be ubiquitous in the environment and has been detected in ground and surface waters, sediment sludge and at several Superfund sites. Previous studies using rats ...

  2. PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    Nigel Noriega, Jonathan Furr, Christy Lambright, Vickie Wilson, L. Earl Gray Jr.

    The plasticizer Di (2-ethylhexyl) phtha...

  3. PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    Nigel Noriega, Jonathan Furr, Christy Lambright, Vickie Wilson, L. Earl Gray Jr.

    The plasticizer Di (2-ethylhexyl) phtha...

  4. Plant uptake and enhanced dissipation of di(2-ethylhexyl) phthalate (DEHP) in spiked soils by different plant species.

    PubMed

    Li, Yan-Wen; Cai, Quan-Ying; Mo, Ce-Hui; Zeng, Qiao-Yun; Lü, Huixiong; Li, Qu-Sheng; Xu, Guo-Sheng

    2014-01-01

    This study was conducted to investigate the uptake, accumulation and the enhanced dissipation of di(2-ethylhexyl) phthalate (DEHP) spiked in soil (with a concentration of 117.4 +/- 5.2 mg kg(-1)) by eleven plants including eight maize (Zea mays) cultivars and three forage species (alfalfa, ryegrass and teosinte). The results showed that, after 40 days of treatment, the removal rates of DEHP ranged from 66.8% (for the control) to 87.5% (for the maize cultivar of Huanong-1). Higher removal rate was observed during the first 10 days than the following days. Plants enhanced significantly the dissipation of DEHP in soil. Enhanced dissipation amount in planted soil was 13.3-122 mg pot(-1) for DEHP, and a net removal of 2.2%-20.7% of the initial DEHP was obtained compared with non-plant soil. The contribution of plant uptake to the total enhanced dissipation was < 0.3%, and the enhanced dissipation of soil DEHP might be derived from plant-promoted biodegradation and sorption stronger to the soil. Nevertheless, the capability in accumulation and enhanced dissipation of DEHP from spiked soils varied within different species and cultivars.

  5. Separation of carrier-free {sup 90}Y from high level waste by extraction chromatographic technique using 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17)

    SciTech Connect

    Achuthan, P.V.; Dhami, P.S.; Kannan, R.; Gopalakrishnan, V.; Ramanujam, A.

    2000-01-01

    An extraction chromatographic technique has been developed for the separation of carrier-free {sup 90}Y from the {sup 90}Sr present in the high level waste (HLW) of the Purex process. When a Purex HLW solution in 2--3 M HNO{sub 3} is passed through a CMPO-Chromosorb-102 (CAC) column, all the trivalent, tetravalent, and hexavalent ions are sorbed. The effluent from this experiment, after adjusting the pH to 2 with NaOH, was passed through a 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17)-Chromosorb-102 (KSMC) extraction chromatographic column where only {sup 90}Y was sorbed. All the other ions ({sup 90}Sr, {sup 137}Cs, {sup 125}Sb, {sup 106}Ru, {sup 106}Rh, etc.) were washed off with dilute HNO{sub 3} (pH 2), and carrier-free {sup 90}Y was eluted with 0.5 M HNO{sub 3}. This technique can yield {sup 90}Y in mCi levels in pure form for medical applications. The {sup 90}Sr can be used repeatedly after allowing for {sup 90}Y buildup.

  6. Cytotoxicity, acute oral toxicity, and skin irritation of 2-ethylhexyl-2,4,5-trimethoxycinnamate and di(2-ethylhexyl)-2,4,5-trimethoxybenzalmalonate.

    PubMed

    Monhaphol, Thitinun; Yibchok-Anun, Sirinthorn; Banlunara, Wijit; Wittayasuporn, Mayura; Palaga, Tanapat; Asawanonda, Pravit; Wanichweacharungruang, Supason

    2008-01-01

    Safety of two new ultraviolet (UV) filters, 2-ethylhexyl-2,4,5-trimethoxycinnamate (E8) and 2-ethylhexyl-2,4,5-trimethoxybenzalmalonate (B8), has been evaluated through the human melanoma cytotoxicity test and seven-day acute oral toxicity studies in rats. At 2.5 mg/mL, both compounds gave similar cell viability to the control. LD50 values for E8 and B8 are more than 5000 and 1000 mg/kg body weight, respectively. No significant difference in body weight and hematological parameters among the 0, 5, 50, 500, and 5000 mg/Kg E8-treated animals could be detected. Pathological examination of rat tissues collected at the end of the study period revealed no significant difference between the control and all E8-administered rats. There was no significant difference in all clinical blood chemistry parameters (aspartate aminotransferase, creatinine, blood urea nitrogen, and cholesterol), except alanine aminotransferase (ALT), between the control and the E8-treated animals. All ALT values were, however, in the normal range of SD rats. E8 showed negative results for the skin irritation study on human volunteers, using patch and photopatch tests. Excitation of respiratory signs of dypsnea in 10, 100, and 1000 mg/Kg B8-treated rats could be observed during 1-24 h. All groups were, however, normal during the second to the seventh day. Hematological parameters of the 0, 10, 100, and 1000 mg/Kg B8-treated animals showed no significant difference. Pathological examination revealed no significant difference between the control and all B8-administered rats. However, significant differences in some clinical blood chemistry parameters and body weights between the control and some B8-treated animals could be detected. All values, however, were in the normal ranges of the SD rats.

  7. Micelles and reverse micelles in the nickel bis(2-ethylhexyl) sulfosuccinate/water/isooctane microemulsion.

    PubMed

    Garza, Cristina; Carbajal-Tinoco, Mauricio D; Castillo, Rolando

    2004-12-01

    The ternary system Ni(2+)(AOT)(2) (nickel 2-bis[2-ethylhexyl] sulfosuccinate)/water/isooctane presents w/o and o/w microemulsions with a Winsor progression (2Phi-3Phi-2Phi), without the addition of salt; the "fish diagram" was obtained for alpha=0.5 and gamma=0.02-0.22. Using static and dynamic light scattering the micellar size, the ratio of water to surfactant, and the density of micelles for this system were estimated. In addition, the mean interfacial curvature as a function of temperature was obtained.

  8. Uptake of di-(2-ethylhexyl) phthalate of vegetables from plastic film greenhouses.

    PubMed

    Fu, Xiaowei; Du, Qizhen

    2011-11-09

    Uptake of di-(2-ethylhexyl) phthalate (DEHP) of nine vegetables including potherb mustard, bok choy, celery, spinach, cabbage, leaf of tube, lettuce, garlic, and edible amaranth in plastic film greenhouses with different plastic films, film thickness, greenhouse age, and greenhouse height was studied. The results showed that the higher the DEHP content of film, the thicker the film, the lower the height of the greenhouse, and the younger the age of the greenhouse were, the higher the DEHP concentration of vegetables was. The results afford significant information for production of safe vegetables with low level DEHP contamination.

  9. Effects of Mono-(2-Ethylhexyl) Phthalate and Di-(2-Ethylhexyl) Phthalate Administrations on Oocyte Meiotic Maturation, Apoptosis and Gene Quantification in Mouse Model

    PubMed Central

    Absalan, Forouzan; Saremy, Sadegh; Mansori, Esrafil; Taheri Moghadam, Mahin; Eftekhari Moghadam, Ali Reza; Ghanavati, Razie

    2017-01-01

    Objective Phthalates, which are commonly used to render plastics into soft and flexible materials, have also been determined as developmental and reproductive toxicants in human and animals. The purpose of this study was to evaluate the effect of mono-(2- ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) oral administrations on maturation of mouse oocytes, apoptosis and gene transcription levels. Materials and Methods In this experimental study, immature oocytes recovered from Naval Medical Research Institute (NMRI) mouse strain (6-8 weeks), were divided into seven different experimental and control groups. Control group oocytes were retrieved from mice that received only normal saline. The experimental groups I, II or III oocytes were retrieved from mice treated with 50, 100 or 200 µl DEHP (2.56 µM) solution, respectively. The experimental groups IV, V or VI oocytes were retrieved from mouse exposed to 50, 100 or 200 µl MEHP (2.56 µM) solution, respectively. Fertilization and embryonic development were carried out in OMM and T6 medium. Apoptosis was assessed by annexin V-FITC/Dead Cell Apoptosis Kit, with PI staining. In addition, the mRNA levels of Pou5f1, Ccna1 and Asah1 were examined in oocytes. Finally, mouse embryo at early blastocyst stage was stained with acridine-orange (AO) and ethidium-bromide (EB), in order to access their viability. Results The proportion of oocytes that progressed up to metaphase II (MII) and 2-cells embryo formation stage was significantly decreased by exposure to MEHP or DEHP, in a dose-dependent manner. Annexin V and PI positive oocytes showed greater quantity in the treated mice than control. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) revealed that expression levels of Pou5f1, Asah1 and Ccna1 were significantly lower in the treated mouse oocytes than control. The total cell count for blastocyst developed from the treated mouse oocytes was lower than the controls. Conclusion These

  10. Achromobacter denitrificans strain SP1 efficiently remediates di(2-ethylhexyl)phthalate.

    PubMed

    Pradeep, S; Josh, M K Sarath; Binod, P; Devi, R Sudha; Balachandran, S; Anderson, Robin C; Benjamin, Sailas

    2015-02-01

    This study describes how Achromobacter denitrificans strain SP1, a novel isolate from heavily plastics-contaminated sewage sludge efficiently consumed the hazardous plasticizer, di(2-ethylhexyl)phthalate (DEHP) as carbon source supplemented in a simple basal salt medium (BSM). Response surface methodology was employed for the statistical optimization of the process parameters such as temperature (32°C), agitation (200 rpm), DEHP concentration (10 mM), time (72 h) and pH (8.0). At these optimized conditions, experimentally observed DEHP degradation was 63%, while the predicted value was 59.2%; and the correlation coefficient between them was 0.998, i.e., highly significant and fit to the predicted model. Employing GC-MS analysis, the degradation pathway was partially deduced with intermediates such as mono(2-ethylhexyl)phthalate and 2-ethyl hexanol. Briefly, this first report describes A. denitrificans strain SP1 as a highly efficient bacterium for completely remediating the hazardous DEHP (10 mM) in 96 h in BSM (50% consumed in 60 h), which offers great potentials for efficiently cleaning the DEHP-contaminated environments such as soil, sediments and water upon its deployment.

  11. Inhibition of human platelet phospholipase A/sub 2/ by mono(2-ethylhexyl)phthalate

    SciTech Connect

    Labow, R.S.; Meek, E.; Adams, G.A.; Rock, G.

    1988-06-01

    There is evidence that the carcinogenic and teratogenic effects attributed to the plasticizer di(2-ethylhexyl)phthalate (DEHP) are due to its major metabolite mono(2-ethylhexyl)phthalate (MEHP). MEHP is also formed ex vivo by a plasma enzyme in blood products stored in polyvinyl chloride (PVC) DEHP plastic containers. People who receive large amounts of blood products, such as hemophiliacs or patients undergoing hemodialysis, cardiopulmonary bypass, or massive transfusion, are exposed to significant levels of plasticizer. In this study, the platelet was used to show that MEHP inhibits phospholipase A/sub 2/ (PLA/sub 2/), one of the enzymes important in the release of arachidonic acid from membrane phospholipids. PLA/sub 2/ was measured by the liberation of /sup 14/C-arachidonic acid from 1-stearoyl-2-(1-/sup 14/C)arachidonyl-L-3-phosphatidylcholine. MEHP inhibits PLA/sub 2/ activity noncompetitively in intact human platelets and lysates with a K/sub i/ of 3.7 x 10/sup -4/ M. DEHP does not inhibit PLA/sub 2/ in whole platelets. Inhibition of PLA/sub 2/ by MEHP occurs at only three times the circulating level of MEHP measured in neonates undergoing exchange transfusion and 20-fold the levels experienced by patients during cardiopulmonary bypass. Therefore, infants and adult patients with multisystem failure who accumulate MEHP in their blood may be at risk for decreased platelet function.

  12. Effects of maternal exposure to di(2-ethylhexyl)phthalate (DEHP) during pregnancy on susceptibility to neonatal asthma

    SciTech Connect

    Shin, In-Sik; Lee, Mee-Young; Cho, Eun-Sang; Choi, Eun-young; Son, Hwa-Young; Lee, Kyoung-Youl

    2014-02-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and is widely dispersed in the environment. In this study, we investigated the effects of maternal exposure to DEHP during pregnancy on neonatal asthma susceptibility using a murine model of asthma induced by ovalbumin (OVA). Pregnant BALB/c mice received DEHP from gestation day 13 to lactation day 21. Their offspring were sensitized on postnatal days (PNDs) 9 and 15 by intraperitoneal injection of 0.5 μg OVA with 200 μg aluminum hydroxide. On PNDs 22, 23 and 24, live pups received an airway challenge of OVA for 30 min. Offspring from pregnant mice that received DEHP showed reductions in inflammatory cell count, interleukin (IL)-4, IL-13, and eotaxin in their bronchoalveolar lavage fluid and in total immunoglobulin E and OVA-specific IgE in their plasma compared with offspring from pregnant mice that did not receive DEHP treatment. These results were consistent with histological analysis and immunoblotting. Maternal exposure to DEHP reduces airway inflammation and mucus production in offspring, with a decrease in inducible nitric oxide synthase (iNOS) in the lung tissue. This study suggests that maternal exposure to DEHP during pregnancy reduces asthmatic responses induced by OVA challenge in offspring. These effects were considered to be closely related to the suppression of Th2 immune responses and iNOS expression. - Highlights: • Maternal exposure to di(2-ethylhexyl)phthalate reduces asthmatic response in pups. • Di(2-ethylhexyl)phthalate reduces eosinophilia induced by ovalbumin exposure. • Di(2-ethylhexyl)phthalate reduces T-helper type 2 cytokine production. • Di(2-ethylhexyl)phthalate attenuates airway inflammation and mucus production. • Di(2-ethylhexyl)phthalate suppresses inducible nitric oxide synthase in lung tissue.

  13. Comparison of the release behaviors of di (2-ethylhexyl) phthalate and tri(2-ethylhexyl) trimellitate from the polyvinyl-chloride infusion set into pharmaceutical solutions.

    PubMed

    Zhang, Hong; Yang, Fengmin; Shen, Gang; Yang, Yueyang; Tang, Yalin

    2015-05-01

    Polyvinyl-chloride (PVC) with plasticizers of di(2-ethylhexyl) phthalate (DEHP) and tris(2-ethyl- hexyl) trimellitate (TOTM) is widely used in medical and paramedical appliances. However, such plasticizers can leach from PVC products into contact solutions. The aim of this study is to investigate the release behaviors of DEHP and TOTM from the PVC intravenous infusion set into various pharmaceutical solutions under the simulated clinical conditions, such as the lipophilic substances (paclitaxel) , parenteral nutrition (fat emulsion injection) , acid and alkali pharmaceutical solution (levofloxacin hydrochloride injection, pH 3.0-5.0 and furosemide, pH 8.0-9.0). A simple and rapid high-performance liquid chromatographic method with UV detection (HPLC-UV) for the determination of DEHP or TOTM released from PVC medical devices into the above intravenous preparations was developed. The cumulative amounts of DEHP or TOTM released in 24 h were in the same following order: paclitaxel > fat emulsion injection levofloxacin hydrochloride > furosemide solution. From a comparison of the cumulative amounts of released DEHP and TOTM from the above solutions, we found that the cumulative amount of TOTM is far less than that of DEHP, under the same conditions. The cumulative amount of the DEHP released in 24 h in the paclitaxel solution was 21. 14 mg, while under the same conditions, the cumulative amount of TOTM was only 0. 078 mg. The cumulative amount of DEHP is assumed to be about 270 times that of the released TOTM. Thus TOTM could be a superior alternative to DEHP for use in medical devices because of its potential lower leachability.

  14. Vaporization behavior of tetraoctylphosphonium bis(2-ethylhexyl)phosphate ionic liquid

    DOE PAGES

    McMurray, J. W.; Zhou, Y.; Luo, H. M.; ...

    2016-11-18

    We determined the equilibrium vapor pressures, pe, of the ionic liquid tetraoctylphosphonium bis(2-ethylhexyl)phosphate ([P8888][DEHP]) over the temperature range 409–495 K using mass loss Knudsen effusion. The pe versus temperature relationship compares well to 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][NTf2]) but is lower than that of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) when measured using the same technique. Here, we determined the discrepancies between the pe for [C8mim][NTf2] and [C2mim][NTf2] with previous studies is discussed. Finally, the enthalpy and entropy of vaporization for all three fluids are estimated from the Clasius-Clapeyron relation.

  15. Prenatal exposure to di(2-ethylhexyl) phthalate impairs development of the mouse neocortex.

    PubMed

    Komada, Munekazu; Gendai, Yuuya; Kagawa, Nao; Nagao, Tetsuji

    2016-09-30

    Di(2-ethylhexyl) phthalate (DEHP) is currently the most commonly used phthalate for the production of flexible polyvinyl chloride. Phthalates including DEHP have been labeled as potential endocrine disruptors. The effect on the development of the neocortex, however, is unknown. To evaluate the neurodevelopmental effects of prenatal DEHP exposure at 1 and 100mg/kg/day or 100 and 500mg/kg/day in fetal and newborn mice, we performed a detailed histologic analysis of the developing dorsal telencephalon and neocortex. The observation of fetuses exposed to DEHP revealed reductions of proliferation and neurogenesis (1 and 100mg/kg) and an increase in cell death (500mg/kg). In addition, the newborns prenatally exposed to DEHP showed an abnormal neuronal distribution and a decrease in neurons. These findings suggest that prenatal DEHP exposure induces neurodevelopmental toxicity associated with the neural stem cell niche and corticogenesis.

  16. The Adverse Cardiac Effects of Di(2-ethylhexyl) phthalate and Bisphenol A

    PubMed Central

    Posnack, Nikki Gillum

    2014-01-01

    The ubiquitous nature of plastics has raised concerns pertaining to continuous exposure to plastic polymers and human health risks. Of particular concern is the use of endocrine-disrupting chemicals (EDCs) in plastic production, including Di(2-ethylhexyl) phthalate (DEHP) and Bisphenol A (BPA). Widespread and continuous exposure to DEHP and BPA occurs through dietary intake, inhalation, dermal and intravenous exposure via consumer products and medical devices. This article reviews the literature examining the relationship between DEHP and BPA exposure and cardiac toxicity. In vitro and in vivo experimental reports are outlined, as well as epidemiological studies which examine the association between these chemicals and cardiovascular outcomes. Gaps in our current knowledge are also discussed, along with future investigative endeavors that may help resolve whether DEHP and/or BPA exposure has a negative impact on cardiovascular physiology. PMID:24811950

  17. N-(2-Ethylhexyl)carbazole: A New Fluorophore Highly Suitable as a Monomolecular Liquid Scintillator.

    PubMed

    Montbarbon, Eva; Sguerra, Fabien; Bertrand, Guillaume H V; Magnier, Élodie; Coulon, Romain; Pansu, Robert B; Hamel, Matthieu

    2016-08-16

    The synthesis, photophysical properties, and applications in scintillation counting of N-(2-ethylhexyl)carbazole (EHCz) are reported. This molecule displays all of the required characteristics for an efficient liquid scintillator (emission wavelength, scintillation yield), and can be used without any extra fluorophores. Thus, its scintillation properties are discussed, as well as its fast neutron/gamma discrimination. For the latter application, the material is compared with the traditional liquid scintillator BC-501 A, and other liquid fluorescent molecules classically used as scintillation solvents, such as xylene, pseudocumene (PC), linear alkylbenzenes (LAB), diisopropylnaphthalene (DIN), 1-methylnaphthalene (1-MeNapht), and 4-isopropylbiphenyl (iPrBiph). For the first time, an excimeric form of a molecule has been advantageously used in scintillation counting. A moderate discrimination between fast neutrons and gamma rays was observed in bulk EHCz, with an apparent neutron/gamma discrimination potential half of that of BC-501 A.

  18. Aqueous leaching of di-2-ethylhexyl phthalate and "green" plasticizers from poly(vinyl chloride).

    PubMed

    Kastner, Joshua; Cooper, David G; Marić, Milan; Dodd, Patrick; Yargeau, Viviane

    2012-08-15

    A method was developed to assess leaching of several poly(vinyl chloride) (PVC) plasticizers in aqueous media using gas chromatography (GC), and compared to a gravimetric standard test method (ASTM Method D1239). The GC method was a more direct measurement of plasticizer concentration in the aqueous phase. The leaching of commercial plasticizers, as well as several series of "green" candidate plasticizers, were assessed as a function of their molecular characteristics and compared to the industry standard PVC plasticizer, di-2-ethylhexyl phthalate (DEHP). It was found that plasticizers containing longer alkyl chains or non-polar branching emanating from polar structural units, increased the hydrophobicity of the molecule and reduced its aqueous leaching rate. Several "green" plasticizer candidates were found to minimize aqueous leaching to rates ten times below that of DEHP; notably dioctyl succinate (DOS), dihexyl maleate (DHM), methyl cyclohexyl diester (MCDE), diethylhexyl succinate (DEHS), hexanediol dibenzoate (C6), and the commercially available Hexamoll® DINCH.

  19. Potential hazards of exposure to di-(2-ethylhexyl)-phthalate in babies. a review.

    PubMed

    Latini, G

    2000-11-01

    Many plastic items are made of polyvinylchloride (PVC) blended with plasticizers. The most frequently used plasticizer is di-(2-ethylhexyl)-phthalate (DEHP). DEHP migrates at a constant rate from plastics to the environment: it has been detected in water, soil and food and is therefore considered as a widespread environmental contaminant. Over the past several years, a number of publications concerning toxic effects of DEHP on animals and humans have been reported. Although DEHP is suggested to be of low acute toxicity, long-term exposure, especially in human beings at risk such as pregnant women and children, requires more in-depth studies. If DEHP toxicity in humans were to be confirmed, it would be advisable in the future to replace current PVC plasticizers, especially if they come into contact with babies, with better-quality materials.

  20. Vaporization behavior of tetraoctylphosphonium bis(2-ethylhexyl)phosphate ionic liquid

    SciTech Connect

    McMurray, J. W.; Zhou, Y.; Luo, H. M.; Qu, J.

    2016-11-18

    We determined the equilibrium vapor pressures, pe, of the ionic liquid tetraoctylphosphonium bis(2-ethylhexyl)phosphate ([P8888][DEHP]) over the temperature range 409–495 K using mass loss Knudsen effusion. The pe versus temperature relationship compares well to 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][NTf2]) but is lower than that of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) when measured using the same technique. Here, we determined the discrepancies between the pe for [C8mim][NTf2] and [C2mim][NTf2] with previous studies is discussed. Finally, the enthalpy and entropy of vaporization for all three fluids are estimated from the Clasius-Clapeyron relation.

  1. Biochar reduces the bioavailability of di-(2-ethylhexyl) phthalate in soil.

    PubMed

    He, Lizhi; Fan, Shiliang; Müller, Karin; Hu, Guotao; Huang, Huagang; Zhang, Xiaokai; Lin, Xiaoming; Che, Lei; Wang, Hailong

    2016-01-01

    A pot experiment was conducted to evaluate the effect of biochars on the bioavailability of di-(2-ethylhexyl) phthalate (DEHP) in two soils using Brassica chinensis L. as an indicator plant. The residual concentrations of DEHP tended to be higher in the biochar-amended soils than in the control soils. They were lower (p<0.05) in the high organic carbon content soil (HOC; 2.2%C) than in the low organic carbon content soil (LOC; 0.35%C). The DEHP concentrations in plant shoots grown in the HOC soils were lower than those in the LOC soils (p<0.05). Compared to the control, the biochar addition decreased the DEHP concentrations in shoots grown in the LOC soils; whereas there was no significant difference in the HOC soils. Our results showed that soil OC content as well as biochar properties are the key factors influencing the bioavailability of DEHP in soils.

  2. An Advanced TALSPEAK Concept Using 2-Ethylhexylphosphonic Acid Mono-2-Ethylhexyl Ester as the Extractant

    SciTech Connect

    Lumetta, Gregg J.; Casella, Amanda J.; Rapko, Brian M.; Levitskaia, Tatiana G.; Pence, Natasha K.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-12-21

    A method for separating the trivalent actinides and lanthanides is being developed using 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) as the extractant. The method is based on the preferential binding of the actinides in the aqueous phase by N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), which serves to keep the actinides in the aqueous phase while the lanthanides are extracted into an organic phase containing HEH[EHP]. The process is very robust, showing little dependence upon the pH or the HEH[EHP], HEDTA, and citrate concentrations over the ranges that might be expected in a nuclear fuel recycling plant. Single-stage runs with a 2-cm centrifugal contactor indicate that modifications to the process chemistry may be needed to increase the extraction rate for Sm, Eu, and Gd. The hydraulic properties of the system are favorable to application in centrifugal contactors.

  3. Aqueous solubility and Daphnia magna chronic toxicity of di(2-ethylhexyl) adipate.

    PubMed

    Robillard, K A; Dufresne, D L; Gorsuch, J W; Stubblefield, W A; Staples, C A; Parkerton, T F

    2008-06-01

    A water solubility of 5.5 (+/-0.22) microg/L for di(2-ethylhexyl) adipate (DEHA) was measured using the slow-stir method. This value is consistent with computer estimations and over two orders of magnitude lower than that previously determined using the shake-flask method. We performed a 21-day chronic Daphnia magna limit test at an average exposure of 4.4 microg/L in laboratory diluent water to avoid insoluble test material and avoid physical entrapment. One hundred percent of the DEHA-treated organisms survived compared to 90% survival in both the controls and solvent controls. Mean neonate reproduction was 152, 137, and 148 and mean dry weight per surviving female was 0.804, 0.779, and 0.742 mg in the DEHA treatment, control, and solvent control, respectively. No adverse effects were observed.

  4. Vaporization behavior of tetraoctylphosphonium bis(2-ethylhexyl)phosphate ionic liquid

    NASA Astrophysics Data System (ADS)

    McMurray, J. W.; Zhou, Y.; Luo, H. M.; Qu, J.

    2017-01-01

    The equilibrium vapor pressures, pe, of the ionic liquid tetraoctylphosphonium bis(2-ethylhexyl)phosphate ([P8888][DEHP]) over the temperature range 409-495 K were determined for the first time using mass loss Knudsen effusion. The pe versus temperature relationship compares well to 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide ([C8mim][NTf2]) but is lower than that of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) when measured using the same technique. The discrepancies between the pe determined in this work for [C8mim][NTf2] and [C2mim][NTf2] with previous studies is discussed. The enthalpy and entropy of vaporization for all three fluids are estimated from the Clasius-Clapeyron relation.

  5. Food emulsifier polysorbate 80 increases intestinal absorption of di-(2-ethylhexyl) phthalate in rats.

    PubMed

    Lu, Yu; Wang, Ying-Ying; Yang, Nan; Zhang, Dan; Zhang, Feng-Yi; Gao, Hai-Tao; Rong, Wen-Ting; Yu, Shu-Qin; Xu, Qian

    2014-06-01

    The aim of the present research was to explore whether food emulsifier polysorbate 80 can enhance the absorption of di-(2-ethylhexyl) phthalate (DEHP) and its possible mechanism. We established the high-performance liquid chromatography (HPLC) method for detecting DEHP and its major metabolite, mono-ethylhexyl phthalate (MEHP) in rat plasma, and then examined the toxicokinetic and bioavailability of DEHP with or without polysorbate 80 in rats. The study of its mechanism to increase the absorption of phthalates demonstrated that polysorbate 80 can induce mitochondrial dysfunction in time- and concentration-dependence manners in Caco-2 cells by reducing mitochondrial membrane potential, diminishing the production of the adenosine triphosphate, and decreasing the activity of electron transport chain. Our results indicated that food emulsifier applied in relatively high concentrations in even the most frequently consumed foods can increase the absorption of DEHP, and its role may be related to the structure and function damages of mitochondria in enterocytes.

  6. Tumor-initiating and promoting activities of di(2-ethylhexyl) phthalate in vivo and in vitro.

    PubMed

    Ward, J M; Diwan, B A; Ohshima, M; Hu, H; Schuller, H M; Rice, J M

    1986-03-01

    The carcinogenic effects of di(2-ethylhexyl) phthalate (DEHP), including its potential as an initiator and as a promoter of carcinogenesis, were studied in mouse liver and skin and in rat liver in vivo, and in mouse epidermis-derived JB6 cells in vitro. A mouse model for liver initiation and promotion involved initiation by injection of N-nitrosodiethylamine (DEN) intraperitoneally into male B6C3F1 mice at 4 weeks of age, followed by exposure to either DEHP in the diet (3000, 6000, or 12,000 ppm) or phenobarbital in the drinking water (500 ppm), beginning 1 to 2 weeks later and continuing for periods of from 1 day to 18 months. Female F344/NCr rats were subjected to a similar protocol in which promotion continued for 14 weeks. DEHP promoted focal hepatocellular proliferative lesions (FHPL), including hyperplastic foci and neoplasms initiated by DEN in mice but not in rats. Skin-painting studies in female CD-1 or SENCAR mice involved initiation by a single topical exposure to 7,12-dimethylbenz[a]-anthracene (DMBA) applied to the dorsal skin, followed by repeated percutaneous exposure to a tumor promoter, either DEHP or 12-O-tetradecanoylphorbol-13-acetate (TPA). To test for two-stage skin tumor promotion, SENCAR mice were initiated with DMBA and then TPA was administered for only 2 weeks, after which DEHP was subsequently administered for 26 weeks. DEHP displayed very weak complete promoting activity and definite second stage promoting activity in SENCAR mouse skin, but was inactive under our conditions on CD-1 mouse skin. In vitro promoting activity of DEHP and its hydrolysis products, mono(2-ethylhexyl) phthalate (MEHP) and 2-ethylhexanol (EH), was studied by using promotable mouse epidermis-derived JB6 cells. DEHP and MEHP promoted JB6 cells to anchorage independence, while EH did not.

  7. Mono-2-Ethylhexyl Phthalate Induces Oxidative Stress Responses in Human Placental Cells In Vitro

    PubMed Central

    Tetz, Lauren M; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D; Loch-Caruso, Rita

    2013-01-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. PMID:23360888

  8. Degradation of Di(2-Ethylhexyl) Phthalate by a Novel Gordonia alkanivorans Strain YC-RL2.

    PubMed

    Nahurira, Ruth; Ren, Lei; Song, Jinlong; Jia, Yang; Wang, Junhuan; Fan, Shuanghu; Wang, Haisheng; Yan, Yanchun

    2017-03-01

    One bacterial strain, YC-RL2, isolated from petroleum-contaminated soil, could utilize environmental hormone Di(2-Ethylhexyl) phthalate (DEHP) as a sole carbon source for growth. Strain YC-RL2 was identified as Gordonia alkanivorans by 16S rRNA gene analysis and Biolog tests. The effects of environmental factors which might affect the degrading process were optimized at 30 °C and pH 8.0. Strain YC-RL2 showed superior halotolerance and could tolerate up to 0-5% NaCl in trace element medium supplemented with DEHP, although the DEHP degradation rates slowed as NaCl concentration increased. It also showed an outstanding performance in a wide range of pH (6.0-11.0). Meanwhile, strain YC-RL2 was able to withstand high concentrations of DEHP (from 100 to 800 mg/L), and the degradation rates were all above 94%. The DEHP intermediates were detected by HPLC-MS, and the degradation pathway was deduced tentatively. DEHP was transformed into phthalic acid (PA) via mono (2-ethylhexyl) phthalate (MEHP), and PA was further utilized for growth via benzoic acid (BA). The enzyme expected to catalyze the hydrolysis of MEHP to PA was identified from strain YC-RL2. Further investigation found that the enzyme could catalyze the transformation of a wide range of monoalkyl phthalates to PA. This study is the first report about species G. alkanivorans which could degrade several kinds of phthalic acid esters (PAEs), and indicates its application potential for bioremediation of PAE-polluted sites.

  9. Effect of mono-(2-ethylhexyl) phthalate on steroid production of human granulosa cells

    SciTech Connect

    Reinsberg, Jochen Wegener-Toper, Petra; Ven, Katrin van der; Ven, Hans van der; Klingmueller, Dietrich

    2009-08-15

    The phthalate ester mono-(2-ethylhexyl) phthalate (MEHP) is the active metabolite of di-(2-ethylhexyl) phthalate, a high-production-volume chemical used as a plasticizer and solvent in numerous consumer products. MEHP has been demonstrated to be a reproductive toxicant in rodents decreasing estradiol and progesterone production in preovulatory granulosa cells. In the present study, we examined the effect of MEHP on steroid production of human granulosa-lutein (GL) cells. Human GL cells collected from women undergoing in vitro fertilization were cultured in medium containing FSH, hCG and 8-Br-cAMP, respectively, together with various concentrations of MEHP (0-500 {mu}mol L{sup -1}). After incubation for 48 h estradiol and progesterone were assayed in the spent culture medium. Furthermore, aromatase activity and mRNA levels of GL cells were determined. Basal as well as FSH-, hCG- and 8-Br-cAMP-stimulated estradiol production of GL cells was suppressed by MEHP in a dose-dependent manner (IC{sub 50} = 105 {mu}mol L{sup -1}, 138 {mu}mol L{sup -1}, 49 {mu}mol L{sup -1} and 78 {mu}mol L{sup -1}). Furthermore aromatase activity and mRNA levels were reduced in GL cells cultured with MEHP. In contrast, MEHP did not alter the production of progesterone up to a concentration of 167 {mu}mol L{sup -1}. The present data indicate that MEHP is a specific inhibitor of estradiol production in human GL cells with a post-cAMP site of action. The inhibition of estradiol production obviously results from a reduction of aromatase activity on the transcript level. As the in vitro effective doses of MEHP are within the range of real environmental exposure levels an inhibitory effect on estrogen production in vivo seems to be possi0009b.

  10. Mono(2-ethylhexyl)phthalate accumulation disturbs energy metabolism of fat cells.

    PubMed

    Chiang, Huai-chih; Kuo, Ya-Ting; Shen, Chih-Che; Lin, Yi-Hua; Wang, Shu-Li; Tsou, Tsui-Chun

    2016-03-01

    Phthalates are lipophilic and tend to accumulate in adipose tissue, an important regulator of energy balance and glucose homeostasis. The study aimed to determine whether cellular phthalate accumulation influenced fat cell energy metabolism. Following a 3-day treatment with adipogenesis-inducing medium and a 2-day treatment with adipogenesis-maintaining medium, 3T3-L1 cells differentiated into adipocytes in the presence of a phthalate at a clinically relevant concentration (30-300 μM) for another 6 days. Two phthalates, di(2-ethylhexyl)phthalate and di-n-butylphthalate, and their metabolites, mono(2-ethylhexyl)phthalate (MEHP) and mono-n-butylphthalate, were used here. The phthalate treatments caused no marked effect on cytotoxicity and adipogenesis. Only the MEHP-treated adipocytes were found having smaller lipid droplets; MEHP accumulated in cells in a dose- and time-dependent manner. The MEHP-treated adipocytes exhibited significant increases in lipolysis and glucose uptake; quantitative real-time polymerase chain reaction (qPCR) analysis revealed correlated changes in expression of marker genes involved in adipogenesis, lipid metabolism, and glucose uptake. Analysis of oxygen consumption rate (a mitochondrial respiration indicator) and extracellular acidification rate (a glycolysis indicator) indicated a higher energy metabolism in the adipocytes. qPCR analysis of critical genes involved in mitochondrial biogenesis and/or energy metabolism showed that expression of peroxisome proliferator-activated receptor γ coactivator-1α, sirtuin 3, and protein kinase A were significantly enhanced in the MEHP-treated adipocytes. In vitro evidence of MEHP impacts on lipolysis, glucose uptake/glycolysis, and mitochondrial respiration/biogenesis demonstrates that MEHP accumulation disturbs energy metabolism of fat cells.

  11. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    SciTech Connect

    Tetz, Lauren M.; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D.; Loch-Caruso, Rita

    2013-04-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene

  12. Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), using the parallelogram approach

    EPA Science Inventory

    2-ethylhexyltetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants (FRs). BEH-TEBP is used alone as a plasticizer or with EH-TBB in polyurethane foams; both are contaminants in the indoor and outdoor environments. In ...

  13. 77 FR 20314 - 2-Propenoic Acid, 2-Methyl-, 2-Ethylhexyl Ester, Telomer With 1-Dodecanethiol, Ethenylbenzene and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ..., Ethenylbenzene and 2-Methyloxirane Polymer With Oxirane Monoether With 1,2-Propanediol Mono(2-Methyl-2-Propenoate...-methyl-, 2- ethylhexyl ester, telomer with 1-dodecanethiol, ethenylbenzene and 2- methyloxirane polymer...-methyloxirane polymer with oxirane monoether with 1,2-propanediol mono(2-methyl-2-propenoate), hydrogen...

  14. Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

    USDA-ARS?s Scientific Manuscript database

    Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

  15. URINARY AND AMNIOTIC FLUID LEVELS OF PHTHALATE MONOESTERS IN RATS AFTER THE ORAL ADMINISTRATION OF DI(2-ETHYLHEXYL) PHTHALATE AND DI-N-BUTYL PHTHALATE

    EPA Science Inventory

    Two studies were designed to examine amniotic fluid and maternal urine concentrations of the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethylhexyl) phthalate (MEHP) and the di-n-butyl phthalate (DBP) metabolite monobutyl phthalate (MBP) after administration of DEHP and D...

  16. URINARY AND AMNIOTIC FLUID LEVELS OF PHTHALATE MONOESTERS IN RATS AFTER THE ORAL ADMINISTRATION OF DI(2-ETHYLHEXYL) PHTHALATE AND DI-N-BUTYL PHTHALATE

    EPA Science Inventory

    Two studies were designed to examine amniotic fluid and maternal urine concentrations of the di(2-ethylhexyl) phthalate (DEHP) metabolite mono(2-ethylhexyl) phthalate (MEHP) and the di-n-butyl phthalate (DBP) metabolite monobutyl phthalate (MBP) after administration of DEHP and D...

  17. Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

    PubMed

    Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

    2015-10-01

    This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics.

  18. Evaluation of the effect of the concentration of plasticizer di(2-ethylhexyl) phthalate on the quantity of residual monomer vinyl chloride in PVC chest drainage tubes.

    PubMed

    Kicheva, Y I; Richter, H; Popova, E

    2004-08-01

    The effect of amount of plasticizer di(2-ethylhexyl) phthalate (DEHP) amount on the amount of residual monomer vinyl chloride (VC) was determined in samples of plasticised polyvinyl chloride (PVC) with different concentration of plasticiser (22.32-33.05%), before and after sterilisation by a titrimetric method. The titrimetric method was used to determine the VC concentration in a KMnO4 solution where the samples were kept immersed under the same conditions for 2 h. The influence of PVC film extracts with different amounts of DEHP on mouse fibroblast cells L-929 in a culture medium was evaluated by using quantitative tests: the amount of cells (protein determination), viability (MTT test) and proliferation (incorporation of bromodeoxyuridine (BrDU). The amount of vinyl chloride before and after heat sterilisation at 120 degrees C for 30 min was found to be almost the same for all samples and without any dependence on the concentration of DEHP. The extracts of the PVC films which were tested have no toxic effect on cells in a culture medium.

  19. Toxicity effects of di-(2-ethylhexyl) phthalate to Eisenia fetida at enzyme, cellular and genetic levels.

    PubMed

    Ma, Tingting; Zhou, Wei; Chen, Li'ke; Wu, Longhua; Christie, Peter; Zhang, Haibo; Luo, Yongming

    2017-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a dominant phthalic acid ester (PAE) that has aroused public concern due to its resistance to degradation and its toxicity as an endocrine-disrupting compound. Effects of different concentrations of DEHP on Eisenia fetida in spiked natural soil have been studied in the body of the earthworm by means of soil cultivation tests 7, 14, 21 and 28 days after exposure. The results indicated that, in general, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, metallothionein (MT) content, the expression of heat shock protein 70 (HSP 70) and all the tested geno-toxicity parameters are promoted as time elapses and with increasing concentration of DEHP. However, peroxidase (POD) activity, neutral red retention time (NRRT) and mitochondrial membrane potential difference values were found to decrease even at a low concentration of DEHP of 1 mg kg-1 soil (p<0.05). Clear toxic effects of DEHP on E. fetida have been generally recognized by means of the disturbance of antioxidant enzyme activity/content and critical proteins, cell membrane and organelle disorder and DNA damage estimated by length of tail, tail DNA ratio, and tail moment parameters. A concentration of DEHP of 3 mg kg-1 may be recommended as a precaution against the potential risk of PAEs in soils and for indicating suitable threshold values for other soil animals and soil micro-organisms.

  20. Di (2-ethylhexyl) phthalate exposure during pregnancy disturbs temporal sex determination regulation in mice offspring.

    PubMed

    Wang, Yongan; Liu, Wei; Yang, Qing; Yu, Mingxi; Zhang, Zhou

    2015-10-02

    Animal researches and clinical studies have supported the relevance between phthalates exposure and testicular dysgenesis syndrome (TDS). These disorders may comprise common origin in fetal life, especially during sex determination and differentiation, where the mechanism remains unclear. The present study evaluated the disturbances in gene regulatory networks of sex determination in fetal mouse by in utero Di (2-ethylhexyl) phthalate (DEHP) exposure. Temporal expression of key sex determination genes were examined during the critical narrow time window, using whole-mount in situ hybridization and quantitative-PCR. DEHP exposure resulted in significant reduction in mRNA of Sry during sex determination from gestation day (GD) 11.0 to 11.5 in male fetal mice, and the increasing of Sry expression to threshold level on GD 11.5 was delayed. Meanwhile, Gadd45g and Gata4, the upstream genes of Sry, and downstream gene Sox9 were also significantly downregulated in expression. In fetal females, the expression of Wnt4 and beta-catenin were up-regulated by DEHP exposure. Taken together, the results suggest that the potential mechanism of gonadal development disorder by DEHP may origin from repression of important male sex determination signaling pathway, involving Gadd45g → Gata4 → Sry → Sox9. The results would promote a better understanding of the association between phthalate esters (PAEs) exposure and the reductive disorder.

  1. The therapeutic applications of celery oil seed extract on the plasticizer di(2-ethylhexyl) phthalate toxicity.

    PubMed

    El-Shinnawy, Nashwa A

    2015-04-01

    The present study investigated the impact of two doses, 500 mg/kg and 1000 mg/kg, of di(2-ethylhexyl) phthalate (DEHP) and studied the possible therapeutic dose of celery oil seed extract for 6 weeks on some atheroscelerogenic, obesogenic, antioxidant and liver functions in rats. Both doses of DEHP caused over-expression of peroxisome proliferator-activated receptor alpha (PPARα) messenger RNA with significant increase in liver weights, relative liver weights, serum cholesterol (Chol), triglycerides, low-density lipoprotein Chol, liver total lipids, along with an increase in the activities of serum aspartate aminotransferase, alanine aminotransferase, serum endothelin 1 and liver tissue thiobarbituric acid reactive substances (TBARS). Additionally, DEHP administration to rats resulted in significant decrease in final body weights, serum total protein, albumin, liver total protein and serum total nitric oxide. Our study confirmed the role of oral combination of Apium graveolens (celery) oil seed extract at small cumulative doses (50 µl/kg for 6 weeks) with DEHP in ameliorating the toxicological effects of DEHP, which was revealed in reducing the expression of PPARα, lipid profile, with restoring liver functions, vascular oxidative stress and inhibition of TBARS activity.

  2. Thallium extraction from hydrochloric acid media into a deep eutectic solvent using bis(2-ethylhexyl) phosphate

    NASA Astrophysics Data System (ADS)

    Tran, Kate; Volia, Merinda; Tereshatov, Evgeny; Folden, Charles, III

    2016-09-01

    The chemical properties of superheavy elements are relatively unknown due to their short half-lives and difficulty of production. In preparation for a future experiment to study the chemical properties of element 113, separation techniques have been used to study the behavior of its homologs, In and Tl. Previous work studied the liquid-liquid extraction of radioactive 201Tl (t1 / 2 = 3 . 04 d) from various concentrations of HCl into a mixture of menthol and lauric acid that formed a so-called deep eutectic solvent (DES). This work focuses on the effects of adding an extraction agent, bis(2-ethylhexyl) phosphate (HDEHP), to the DES on the efficiency of thallium extraction. The extraction of Tl(I) was generally poor, both with and without HDEHP added. In contrast, 111In (t1 / 2 = 2 . 80 d) showed significant extraction using HDEHP added to the same DES. This difference in behavior could potentially be exploited in a future experiment on the chemistry of element 113. National Science Foundation.

  3. Experimental density measurements of bis(2-ethylhexyl) phthalate at elevated temperatures and pressures

    SciTech Connect

    Bamgbade, Babatunde A; Wu, Yue; Baled, Hseen O; Enick, Robert M; Burgess, Ward A

    2013-08-01

    Experimental high-temperature, high-pressure (HTHP) density data for bis(2-ethylhexyl) phthalate (DEHP) are reported in this study. DEHP is a popular choice as a reference fluid for viscosity calibrations in the HTHP region. However, reliable HTHP density values are needed for accurate viscosity calculations for certain viscometers (e.g. rolling ball). HTHP densities are determined at T = (373, 424, 476, 492, and 524) K and P to 270 MPa using a variable-volume, high-pressure view cell. The experimental density data are satisfactorily correlated by the modified Tait equation with a mean absolute percent deviation (δ) of 0.15. The experimental data are modeled with the Peng–Robinson (PREoS), volume-translated PREoS (VT-PREoS), and perturbed chain statistical associating fluid theory (PC-SAFT EoS) models. The required parameters for the two PREoS and the PC-SAFT EoS models are determined using group contribution methods. The PC-SAFT EoS performs the best of the three models with a δ of 2.12. The PC-SAFT EoS is also fit to the experimental data to obtain a new set of pure component parameters that yield a δ of 0.20 for these HTHP conditions.

  4. Health hazard assessment of occupationally di-(2-ethylhexyl)-phthalate-exposed workers in China.

    PubMed

    Wang, Wenxin; Xu, Xiaobing; Fan, Chinbay Q

    2015-02-01

    Di-(2-ethylhexyl)-phthalate (DEHP) is a potential hazard to human health. The effects of occupational high level DEHP exposure on human health were evaluated by measuring the plasma cholinesterase, residues, renal and hepatic biochemical markers. The study was conducted in three representative polyvinyl chloride manufacturing facilities from large size (S1), medium side (S2) to small size (S3). Total 456 adult males including 352 exposed workers (occupational) and 104 control workers (background) were selected. The average DEHP concentrations in respirable particulate matter were 233, 291, and 707 μg m(-3) for S1-S3, respectively, compared with 0.26 μg m(-3) in the background atmosphere (labeled by S4). The results showed significant decreases in post exposure plasma cholinesterase (PChE) levels (<30%) from the exposed workers as compared to baseline. These exposed workers had been evaluated for plasma DEHP residues. Regression analyses explored that PChE decreased significantly with increasing plasma DEHP residues. Serum aspartate aminotransferase, alanine aminotransferase, creatinine, urea, gamma glutamyltransferase, malondialdehyde, total antioxidant and C-reactive protein were significantly raised as compared to the controls. Of the 352 exposed workers, 116 (33.0%) had a daily DEHP intake 22.7 μg kg bw(-1)d(-1) , which is more than 20 μg kg bw(-1)d(-1) specified by the US Environmental Protection Agency. The study demonstrated that occupational phthalate exposure produces health hazards. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Clinically relevant concentrations of di (2-ethylhexyl) phthalate (DEHP) uncouple cardiac syncytium

    SciTech Connect

    Gillum, Nikki; Karabekian, Zaruhi; Swift, Luther M.; Brown, Ronald P.; Kay, Matthew W.; Sarvazyan, Narine

    2009-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer found in a variety of polyvinyl chloride (PVC) medical products. The results of studies in experimental animals suggest that DEHP leached from flexible PVC tubing may cause health problems in some patient populations. While the cancerogenic and reproductive effects of DEHP are well recognized, little is known about the potential adverse impact of phthalates on the heart. This study examined the effects of clinically relevant concentrations of DEHP on neonatal rat cardiomyocytes. It was found that application of DEHP to a confluent, synchronously beating cardiac cell network, leads to a marked, concentration-dependent decrease in conduction velocity and asynchronous cell beating. The mechanism behind these changes was a loss of gap junctional connexin-43, documented using Western blot analysis, dye-transfer assay and immunofluorescence. In addition to its effect on electrical coupling, DEHP treatment also affected the mechanical movement of myocyte layers. The latter was linked to the decreased stiffness of the underlying fibroblasts, as the amount of triton-insoluble vimentin was significantly decreased in DEHP-treated samples. The data indicate that DEHP, in clinically relevant concentrations, can impair the electrical and mechanical behavior of a cardiac cell network. Applicability of these findings to human patients remains to be established.

  6. Environmental assessment of a phthalate ester, Di(2-Ethylhexyl) phthalate (DEHP), derived from a marine microcosm

    SciTech Connect

    Perez, K.T.; Davey, E.W.; Lackie, N.F.; Morrison, G.E.; Murphy, P.G.; Soper, A.E.; Winslow, D.L.

    1981-10-01

    This study tested the influence of system complexity on the environmental assessment of a chemical. Marine microcosms were perturbed with a phthalate ester, di(2-ethylhexyl) phthalate (DEHP). Concentrations of 1, 10, and 100 ..mu..g of DEHP per litre were added to the water-column subsystem of marine microcosms for 30 days during the summer (18/sup 0/C) and winter (1/sup 0/C) seasons. Significant portions of the DEHP losses from the water-column subsystem during the experiments were due to the complete breakdown of the parent compound to carbon dioxide (CO/sub 2/). In the benthic subsystem, DEHP concentrations in the sediment were increased by more than 50 and 250 times the concentration in the water column during the winter and summer seasons, respectively. Statistically significant (..cap alpha.. = 0.05) reductions in the fluxes of ammonia (NH/sub 3/) from the benthic subsystem were observed in microcosms receiving 100 ..mu..g of DEHP per litre during the summer. Concentrations of DEHP in selected bivalves ranged from 174 to 229 000 ..mu..g of DEHP per wet kilogram, depending upon the water column exposure concentrations and the season of the year.

  7. Effect of Di(2-ethylhexyl)phthalate on Helicobacter pylori-Induced Apoptosis in AGS Cells

    PubMed Central

    Wu, Chien-Yi; Kou, Hwang-Shang; Chen, Chiao-Yun; Huang, Meng-Chuan; Hu, Huang-Ming; Wu, Meng-Chieh; Lu, Chien-Yu; Wu, Deng-Chyang; Wu, Ming-Tsang; Kuo, Fu-Chen

    2013-01-01

    Plastic products are wildly used in human life. Di(2-ethylhexyl)phthalate (DEHP) is an essential additive in plastic manufacturing and is used as plasticizer for many products including plastic food packaging. DEHP is a teratogenic compound and can cause potent reproductive toxicity. DEHP can also cause liver damage, peroxisome proliferation, and carcinogenesis. DEHP is also strongly associated with peptic ulcers and gastric cancer; however, the underlying effect and mechanism of DEHP on the gastrointestinal tract are not entirely clear. The oral infection route of H. pylori parallels the major ingestion route of DEHP into the human body. Therefore, we wanted to study the effect of DEHP and H. pylori exposure on the human gastric epithelial cell line, AGS (gastric adenocarcinoma). The viability of the AGS cell line was significantly lower in 80 μM-DEHP and H. pylori (MOI = 100 : 1) coexposure than DEHP or H. pylori alone. DEHP and H. pylori coexposure also induced caspase-3 activation, and increased Bax/Bcl-2 ratio and DNA fragmentation in AGS cells. These results indicate that DEHP can enhance H. pylori cytotoxicity and induce gastric epithelial cell apoptosis. Therefore, it is possible that DEHP and H. pylori coexposure might enhance the disruption of the gastric mucosa integrity and potentially promote the pathogenesis of gastric carcinogenesis. PMID:24454344

  8. A case of contact urticaria syndrome due to di(2-ethylhexyl) phthalate (DOP) in work clothes.

    PubMed

    Sugiura, Keiji; Sugiura, Mariko; Hayakawa, Ritsuko; Shamoto, Mikihiro; Sasaki, Kazumi

    2002-01-01

    We previously reported a case of contact urticaria syndrome (CUS) due to di(2-ethylhexyl) phthalate (DOP) in a polyvinyl chloride (PVC) grip on cotton gloves. The patient reported in this previous paper was careful not to have any contact with PVC products in his daily life or in his working environment. He discontinued the use of protective gloves with a PVC grip that was the cause of CUS. When working, he used cotton gloves without a PVC grip. We prescribed antihistamines which slightly improved his condition. However, when he wore work clothes while on duty, CUS relapsed. This condition was severe and made him feel anxious. When we advised him to wear a cotton shirt under his work clothes, the contact urticaria did not develop. We suspected that some component of the work clothes was the cause of his symptoms. A prick test with the extract solution of his work clothes showed a wheal and flare at the 15 min reading. The common component of the grip and the work clothes was found by analysis to be DOP.

  9. Mono-(2-Ethylhexyl) Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta

    PubMed Central

    Parobchak, Nataliya; Rosen, Alex; Vetrano, Anna M.; Srinivasan, Aarthi; Wang, Bingbing; Rosen, Todd

    2016-01-01

    Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2) are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52) signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl)-phthalate (MEHP), increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth. PMID:26751383

  10. Presence of plasticizer di-2(ethylhexyl)phthalate in primed extracorporeal circulation circuits.

    PubMed

    Burkhart, Harold M; Joyner, Nitasha; Niles, Scott; Ploessl, Jay; Everett, Jeff; Iannettoni, Mark; Richenbacher, Wayne

    2007-01-01

    Many centers advocate the use of a standby wet-primed extracorporeal membrane oxygenation (ECMO) circuit for rapid deployment during cardiopulmonary resuscitation. However, concerns with regard to the potential health hazards associated with the release of the plasticizer di-2(ethylhexyl)phthalate (DEHP) from the polyvinyl chloride (PVC) tubing exist. The purpose of this study was to determine the time course of DEHP release from a preprimed ECMO circuit and to evaluate the effect of PVC tubing coatings on DEHP release. Seven circuits including three uncoated (Medtronic, Medtronic with albumin, and Medtronic Super Tygon) and four attenuated surfaces (Carmeda, COBE Smart, Medtronic Trillium, and Terumo x-coated) were primed with Plasmalyte A. Samples of the circuit prime were collected over a period of 2 weeks and were analyzed for DEHP, using gas chromatography. Results were compared by using a two-tailed t test. One coated (Carmeda) and all three uncoated circuits leached DEHP. The greatest amount of leaching occurred in the uncoated Medtronic tubing with albumin. The COBE Smart, Medtronic Trillium, and Terumo x-coated circuits had undetectable amounts of DEHP (p = 0.006 vs Medtronic uncoated). Prepriming an ECMO circuit composed of uncoated PVC tubing is associated with DEHP release. Using coated PVC tubing appears to eliminate DEHP release over a 2-week period.

  11. Antifertility and mutagenic effects in mice from parenteral administration of di-2-ethylhexyl phthalate (DEHP)

    SciTech Connect

    Agarwal, D.K.; Lawrence, W.H.; Autian, J.

    1985-01-01

    The subcutaneous administration of 1-10 mg of undiluted di-(2-ethylhexyl)phthalate (DEHP) to adult male ICR mice on d 1, 5, and 10 was followed by mating, one to one, with untreated adult virgin females. A single mating at d 21 resulted in a reduction in the incidence of pregnancies in the DEHP-treated groups. On the other hand, repeated matings with fresh females starting on d 2, 6, 11, 16, and 21, and at weekly intervals through 8 wk, revealed no perceptible effect of DEHP on the incidence of pregnancy. Examination of surgically exposed uteri and ovaries of pregnant females on d 13 of gestation revealed an increase in the incidence of preimplantation losses and early fetal deaths in the DEHP-treated groups; consequently, there were fewer viable fetuses per pregnancy. Mutagenic indices for DEHP, calculated as percent ratios of (1) preimplantation losses/implantations per pregnancy and (2) early fetal deaths/implantations per pregnancy, suggested a dominant lethal mutation effect in the treated mice. These effects tend to be more pronounced on the postmiotic stage of germ-cell development.

  12. Phase behavior of AOT microemulsions in compressible liquids. [AOT = bis(2-ethylhexyl) sodium sulfosuccinate

    SciTech Connect

    McFann, G.J.; Johnston, K.P. )

    1991-06-13

    The phase behavior of bis(2-ethylhexyl) sodium sulfosuccinate (AOT)-alkane-brine systems is described over a wide range of pressure, temperature, and salinity for alkanes from ethane to dodecane. The partitioning of AOT between the oil, middle, and brine phases is reported for propane in order to determine the natural curvature. This is important for understanding separation processes with water-in-oil microemulsions. For the lighter, more compressible alkanes, the pressure effect on the hydrophilicity of the surfactant is much larger and in the opposite direction as for the heavier, less compressible ones. In propane at constant temperature and salinity, water-in-oil (w/o) microemulsions have been converted to middle phase microemulsions and then to oil-in-water (o/w) microemulsions by decreasing the pressure. These phase inversions are described in terms of the immiscibilities in the binary systems, and the molecular interactions at the surfactant interface. Although temperature and salinity are used commonly to manipulate interactions primarily on the water side of the interface, these results show it is possible to control interactions on the oil side by adjusting the pressure. The well-established trends in the phase behavior and size of microemulsion drops for dodecane through hexane are not observed for the lighter alkanes. For butane through ethane, a new unusual behavior is identified and attributed to a significant decrease in the strength of the attractive interactions between the surfactant tails and the alkane.

  13. Effect of the plasticizer di(2-ethylhexyl)phthalate on red cell deformability

    SciTech Connect

    Labow, R.S.; Card, R.T.; Rock, G.

    1987-07-01

    Red cell concentrates (RCC) are stored for 35 to 42 days in plastic containers manufactured with the liquid plasticizer di(2-ethylhexyl)phthalate (DEHP). DEHP leaches from the polyvinylchloride (PVC) plastic bag, then binds to and stabilizes the RC membrane. This study was undertaken to determine the deformability of the RC membrane using an osmotic gradient ektacytometer and to relate these measurements to the concentration of DEHP in the stored RCC. Pooled RCC was aliquoted into PL146 (PVC), PL732 (polyolefin), and PL732 (with added DEHP) bags with samples removed weekly for analysis of osmotic fragility, deformability, and DEHP concentration. The adenosine triphosphate (ATP) content was also measured. The increase in osmotic fragility during storage was greater when RCC was stored without DEHP. In addition, there was a decrease in the maximum elongation index (El max) when there was decreased DEHP in the storage bag. The osmolarity (Omax) at which El max occurred, as well as the Omin, the osmolarity at which minimum elongation (El min) occurred was higher in the PL732 container than in the PL146 or in the PL732 to which DEHP had been added. These changes could be reversed by addition of DEHP at the beginning of the storage period, showing a direct correlation between DEHP concentration during storage and RC membrane flexibility. By a better understanding of the mechanism of DEHP protection, it might be possible to substitute a less toxic stabilizing compound.

  14. Mono-(2-Ethylhexyl) Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta.

    PubMed

    Wang, Ximi K; Agarwal, Monica; Parobchak, Nataliya; Rosen, Alex; Vetrano, Anna M; Srinivasan, Aarthi; Wang, Bingbing; Rosen, Todd

    2016-01-01

    Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2) are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52) signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl)-phthalate (MEHP), increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth.

  15. Maternal exposure to di-(2-ethylhexyl) phthalate disrupts placental growth and development in pregnant mice.

    PubMed

    Zong, Teng; Lai, Lidan; Hu, Jia; Guo, Meijun; Li, Mo; Zhang, Lu; Zhong, Chengxue; Yang, Bei; Wu, Lei; Zhang, Dalei; Tang, Min; Kuang, Haibin

    2015-10-30

    Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and widely dispersed in the environment. DEHP exposure reduces embryo implantations, increases embryonic loss, and decreases fetal body weights. However, no detailed information is available about the effect of DEHP on the placentation during pregnancy. Thus, our aim was to explore the effect of DEHP on the growth and development of placenta in vivo. Mice were administered DEHP by gavages at 125, 250, 500 mg/kg/day from gestational days (GD) 1 until sacrifice. Results showed that DEHP treatment significantly reduced the weight of placenta at GD 13. Histopathologically, in DEHP-treated group, the ectoplacental cones significantly became smaller at GD9, and total area of placenta and area of spongiotrophoblast were significantly reduced at GD 13. Expression levels of Ascl2, Esx1 and Fosl1 mRNA dramatically decreased in DEHP-treated placenta at GD 13. DEHP administration disrupted labyrinth vascularization of placentas, and inhibited proliferation and induced apoptosis of placenta by the activation of caspase-3 and -8, up-regulation of Bax and down-regulation of Bcl-2 mRNA and protein at GD 13. In conclusion, these results suggest that adverse pregnancy outcomes including low birth-weight and pregnancy loss exposed to DEHP are possibly mediated, at least in part, via the suppression of placental growth and development. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Toxicity effects of di-(2-ethylhexyl) phthalate to Eisenia fetida at enzyme, cellular and genetic levels

    PubMed Central

    Chen, Li’ke; Wu, Longhua; Christie, Peter; Zhang, Haibo; Luo, Yongming

    2017-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a dominant phthalic acid ester (PAE) that has aroused public concern due to its resistance to degradation and its toxicity as an endocrine-disrupting compound. Effects of different concentrations of DEHP on Eisenia fetida in spiked natural soil have been studied in the body of the earthworm by means of soil cultivation tests 7, 14, 21 and 28 days after exposure. The results indicated that, in general, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, metallothionein (MT) content, the expression of heat shock protein 70 (HSP 70) and all the tested geno-toxicity parameters are promoted as time elapses and with increasing concentration of DEHP. However, peroxidase (POD) activity, neutral red retention time (NRRT) and mitochondrial membrane potential difference values were found to decrease even at a low concentration of DEHP of 1 mg kg-1 soil (p<0.05). Clear toxic effects of DEHP on E. fetida have been generally recognized by means of the disturbance of antioxidant enzyme activity/content and critical proteins, cell membrane and organelle disorder and DNA damage estimated by length of tail, tail DNA ratio, and tail moment parameters. A concentration of DEHP of 3 mg kg-1 may be recommended as a precaution against the potential risk of PAEs in soils and for indicating suitable threshold values for other soil animals and soil micro-organisms. PMID:28319143

  17. Mono-2-ethylhexyl phthalate disrupts neurulation and modifies the embryonic redox environment and gene expression.

    PubMed

    Sant, Karilyn E; Dolinoy, Dana C; Jilek, Joseph L; Sartor, Maureen A; Harris, Craig

    2016-08-01

    Mono-2-ethylhexl phthalate (MEHP) is the primary metabolite of di-2-ethylhexyl phthalate (DEHP), a ubiquitous contaminant in plastics. This study sought to determine how structural defects caused by MEHP in mouse whole embryo culture were related to temporal and spatial patterns of redox state and gene expression. MEHP reduced morphology scores along with increased incidence of neural tube defects. Glutathione (GSH) and cysteine (Cys) concentrations fluctuated spatially and temporally in embryo (EMB) and visceral yolk sac (VYS) across the 24h culture. Redox potentials (Eh) for GSSG/GSH were increased by MEHP in EMB (12h) but not in VYS. CySS/CyS Eh in EMB and VYS were significantly increased at 3h and 24h, respectively. Gene expression at 6h showed that MEHP induced selective alterations in EMB and VYS for oxidative phosphorylation and energy metabolism pathways. Overall, MEHP affects neurulation, alters Eh, and spatially alters the expression of metabolic genes in the early organogenesis-stage mouse conceptus. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. A miniaturized method for estimating di(2-ethylhexyl) phthalate in bivalves as bioindicators.

    PubMed

    Muñoz-Ortuño, M; Moliner-Martínez, Y; Cogollos-Costa, S; Herráez-Hernández, R; Campíns-Falcó, P

    2012-10-19

    This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD), using C18 as dispersant and acetonitrile-water as eluting solvent, for the analysis of di(2-ethylhexyl) phthalate (DEHP) in biota samples by capillary liquid chromatography coupled to in-tube solid phase microextraction and diode array detection. Recovery studies showed that the combination of C18-Florisil® was optimal using low amount of samples (0.1 g) and with low volumes of acetonitrile-water (2.6 mL 1:3.25, v/v). The sample is processed in less than 30 min, no evaporation step is required. The proposed method was applied to the analysis of DEHP in mussels and of the coastal waters in which they live. The average value of recoveries obtained, with ten spikes realized before MSPD treatment and after, was 91±15%. The detection limit achieved in mussels was 170 μg/kg. Bioconcentration factor values (BCFs) have been discussed, because DEHP can be bioconcentrated in aquatic organisms.

  19. A cost-effective method for estimating di(2-ethylhexyl)phthalate in coastal sediments.

    PubMed

    Muñoz-Ortuño, M; Argente-García, A; Moliner-Martínez, Y; Verdú-Andrés, J; Herráez-Hernández, R; Picher, M T; Campíns-Falcó, P

    2014-01-10

    This study describes the development of a new method for the analysis of di(2-ethylhexyl)phthalate (DEHP) using 0.1-0.3 g of sediment sample, based on matrix solid phase dispersion (MSPD) using C18 as dispersant phase (0.4 g) and acetonitrile-water as eluting solvent (3.4 mL 1:3.25, v/v). No evaporation step is required. 3 mL of extracts were processed on-line by in-tube solid phase microextraction (IT-SPME) coupled to capillary liquid chromatography (CapLC) and diode array detector (DAD). A short analytical column Zorbax SB C18 (35×0.5 mm, 5 μm) provided suitable results. FTIR-ATR was employed for characterizing sediment samples and MSPD procedure. The total analysis time was less than 20 min (MSPD takes about 10 min). The utility of the described approach has been tested by analyzing several real samples. No matrix effect was found. Achieved precision was less than 10% for DEHP estimation. Detection limits in samples were 270 and 90 μg/kg for 0.1 and 0.3 g of taken sediment, respectively.

  20. Developmental changes in the conversion rates of di(2-ethylhexyl)phthalate to monoethylhexyl phthalate in rats

    SciTech Connect

    Gollamudi, R.; Hanumantha, R.; Lawrence, W.H.; Autian, J.

    1985-01-01

    The activities of liver, lung, and kidney of rats of various age groups and that of placenta in hydrolyzing di(2-ethylhexyl) phthalate to mono(2-ethylhexyl) phthalate have been measured. Male and female rats of 45 d of age, neonatal rats within 12 h of parturition, and fetuses and placenta on d 19 of gestation were used. The liver was most active in all age groups; however, the lung and the kidney also had considerable activity. The tissues of the fetuses and the neonate had significant activity. The k/sub m/ values of the enzyme were 4mM in the neonatal liver and 5.9 mM in the adult liver.

  1. The effect of temperature on di(2-ethylhexyl) phthalate leaching from PVC infusion sets exposed to lipid emulsions.

    PubMed

    Rose, R J; Priston, M J; Rigby-Jones, A E; Sneyd, J R

    2012-05-01

    Poly vinyl chloride (PVC) infusion equipment contains substantial amounts of the plasticiser di(2-ethylhexyl) phthalate (DEHP). We determined the amount of DEHP leached from Mediplus Dual TIVA(®) Infusion sets, into lipid and non-lipid infusates. Two propofol admixtures (Diprivan(®) 1%, Propoven(®) 1%), Intralipid(®) 10% and 0.9% saline were evaluated as infusates. Solutions were infused through TIVA sets at 12 ml.h(-1) for 6 h at 24, 32 and 37 °C. In addition, TIVA sets were filled with 2 ml infusates, sealed and incubated at 24 and 37 °C for 6 h. Di(2-ethylhexyl) phthalate was detected in all lipid infusates after dynamic infusion and static contact, and in 0.9% saline after dynamic infusion at 37 °C. At 32 and 37 °C, the quantity of di(2-ethylhexyl) phthalate leaching into the lipid infusates may exceed the recommended maximum exposure amount set by the European Union for DEHP of 20-48 μg.kg(-1) day(-1) if lipid based infusates are used for sedation or intravenous feeding of infants or neonates.

  2. Di-(2-Ethylhexyl)-Phthalate (DEHP) Causes Impaired Adipocyte Function and Alters Serum Metabolites

    PubMed Central

    Klöting, Nora; Hesselbarth, Nico; Gericke, Martin; Kunath, Anne; Biemann, Ronald; Chakaroun, Rima; Kosacka, Joanna; Kovacs, Peter; Kern, Matthias; Stumvoll, Michael; Fischer, Bernd; Rolle-Kampczyk, Ulrike; Feltens, Ralph; Otto, Wolfgang; Wissenbach, Dirk K.; von Bergen, Martin; Blüher, Matthias

    2015-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP), an ubiquitous environmental contaminant, has been shown to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies, but the underlying mechanisms are still unknown. We therefore tested the hypothesis that chronic DEHP exposure causes impaired insulin sensitivity, affects body weight, adipose tissue (AT) function and circulating metabolic parameters of obesity resistant 129S6 mice in vivo. An obesity-resistant mouse model was chosen to reduce a potential obesity bias of DEHP effects on metabolic parameters and AT function. The metabolic effects of 10-weeks exposure to DEHP were tested by insulin tolerance tests and quantitative assessment of 183 metabolites in mice. Furthermore, 3T3-L1 cells were cultured with DEHP for two days, differentiated into mature adipocytes in which the effects on insulin stimulated glucose and palmitate uptake, lipid content as well as on mRNA/protein expression of key adipocyte genes were investigated. We observed in female mice that DEHP treatment causes enhanced weight gain, fat mass, impaired insulin tolerance, changes in circulating adiponectin and adipose tissue Pparg, adiponectin and estrogen expression. Serum metabolomics indicated a general increase in phospholipid and carnitine concentrations. In vitro, DEHP treatment increases the proliferation rate and alters glucose uptake in adipocytes. Taken together, DEHP has significant effects on adipose tissue (AT) function and alters specific serum metabolites. Although, DEHP treatment led to significantly impaired insulin tolerance, it did not affect glucose tolerance, HOMA-IR, fasting glucose, insulin or triglyceride serum concentrations. This may suggest that DEHP treatment does not cause impaired glucose metabolism at the whole body level. PMID:26630026

  3. Beneficial role of celery oil in lowering the di(2-ethylhexyl) phthalate-induced testicular damage.

    PubMed

    Madkour, Naglaa K

    2014-10-01

    Di(2-ethylhexyl) phthalate (DEHP), the most abundant phthalate in the environment, is known to be a reproductive toxicant. Considering the therapeutic significance of medicinal plants, this study was conducted to evaluate the effects of administration of celery oil on DEHP-induced testicular toxicity. The experiment was carried out for 8 weeks on 36 male rats that were divided equally into six groups. Group 1 was kept as normal control (given vehicle), while rats of group 2 were administered orally 200 mg/kg/day of celery oil. Groups 3 and 5 were orally given 500 and 1000 mg DEHP/kg/day, respectively. Groups 4 and 6 were treated with similar doses of DEHP as in groups 3 and 5 plus celery oil (200 mg/kg/day). Body and testicular weights, sperm parameters, serum hormones (testosterone, follicle-stimulating hormone, luteinizing hormone and estradiol), antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) and expression of cytochrome P450 aromatase (CYP19) messenger RNA (mRNA) were investigated at the end of 8th week. Treatment with DEHP alone resulted in a significant decrease in body and testicular weights, sperm parameters and serum hormone levels when compared with control. On the other hand, testicular antioxidant enzymes showed a significant dose-dependent increase. The expression of CYP19 mRNA was significantly reduced by increasing the doses of DEHP. Administration of celery oil along with DEHP partially prevented the decrease in body and testicular weights and enhanced epididymal sperm count, serum hormone levels and the expression of CYP19 mRNA along with diminution in the activities of SOD, GPx and CAT enzymes. The obtained results showed that the celery improved the testicular alterations induced by DEHP in albino rats.

  4. Performance of electrochemical oxidation process for removal of di (2-ethylhexyl) phthalate.

    PubMed

    Espinoza, Josué Daniel García; Drogui, Patrick; Zolfaghari, Mehdi; Dirany, Ahmad; Ledesma, Maria Teresa Orta; Gortáres-Moroyoqui, Pablo; Buelna, Gerardo

    2016-06-01

    Di (2-ethylhexyl) phthalate (DEHP) is the most detected and concentrated plasticizer in environment and wastewaters, worldwide. In this study, different operating parameters such as current intensity, treatment time, type of anodes, and supporting electrolytes were tested to optimized the electro-oxidation process (EOP) for the removal of DEHP in the presence of methanol as a dissolved organic matter. Among the anodes, the Nb/BDD showed the best degradation rate of DEHP, at low current intensity of 0.2 A after 90 min of treatment time with a percentage of degradation recorded of 81 %, compared to 70 % obtained with the Ti/IrO2-RuO2. Furthermore, due to the combination of direct and indirect oxidation, the removal of DEHP in the presence of 1 g/L Na2SO4 was higher than NaBr, even though the oxidant production of NaBr was 11.7 mmol/L against 3.5 mmol/L recorded in the presence of sulfate at 0.5 A and after 60 min of electrolysis time. Under optimal condition (current intensity = 0.5 A, time = 120 min, using Nb/BDD anode and Na2SO4 as supporting electrolyte), the removal of 87.2 % of DEHP was achieved. The total cost of 0.106 US$/m(3) of treated water was achieved based on economical optimization of reactor with current intensity of 0.2 A and 1 g/L Na2SO4.

  5. Mono-2-ethylhexyl phthalate (MEHP) alters histiotrophic nutrition pathways and epigenetic processes in the developing conceptus

    PubMed Central

    Sant, Karilyn E.; Dolinoy, Dana C.; Jilek, Joseph L.; Shay, Brian J.; Harris, Craig

    2016-01-01

    Histiotrophic nutrition pathways (HNPs) are processes by which the organogenesis-stage conceptus obtains nutrients, amino acids, vitamins, and cofactors required for protein biosynthesis and metabolic activities. Nutrients are captured from the maternal milieu as whole proteins and cargoes via receptor-mediated endocytosis in the visceral yolk sac (VYS), degraded by lysosomal proteolysis, and delivered to the developing embryo (EMB). Several nutrients obtained by HNPs are required substrates for one-carbon (C1) metabolism and supply methyl groups required for epigenetic processes, including DNA and histone methylation. Increased availability of methyl donors has been associated with reduced risk for neural tube defects (NTDs). Here we show that mono-2-ethylhexyl phthalate (MEHP) treatment (100 or 250 µM) alters HNPs, C1 metabolism, and epigenetic programming in the organogenesis-stage conceptus. Specifically, 3 h MEHP treatment of mouse embryos in whole culture resulted in dose dependent reduction of HNP activity in the conceptus. To observe nutrient consequences of decreased HNP function, C1 components and substrates and epigenetic outcomes were quantified at 24 h. Treatment with 100 µM MEHP resulted in decreased dietary methyl donor concentrations, while treatment with 100 or 250 µM MEHP resulted in dose-dependent elevated C1 products and substrates. In MEHP-treated EMBs with NTDs, H3K4 methylation was significantly increased, while no effects were seen in treated VYS. DNA methylation was reduced in MEHP-treated EMB with and without NTDs. This research suggests that environmental toxicants such as MEHP decrease embryonic nutrition in a time-dependent manner, and that epigenetic consequences of HNP disruption may be exacerbated in EMB with NTDs. PMID:26507544

  6. Di-(2-ethylhexyl) adipate in selected total diet food composite samples.

    PubMed

    Cao, Xu-Liang; Zhao, Wendy; Churchill, Robin; Dabeka, Robert

    2013-11-01

    Polyvinyl chloride (PVC) food-wrapping films plasticized with di-(2-ethylhexyl) adipate (DEHA) are commonly used by grocery stores in Canada to rewrap meat, poultry, fish, cheese, and other foods. DEHA was assessed as part of the Government of Canada's Chemicals Management Plan. The main source of exposure for most age groups was expected to be food. Although the margin of exposure from food and beverages is considered to be adequately protective, the Government of Canada committed to performing targeted surveys of DEHA in foods and food packaging materials to better define Canadian exposure to DEHA through dietary intake. In order to determine whether more-comprehensive targeted surveys on DEHA in foods should be conducted, 26 food composite samples from the 2011 Canadian total diet study were selected and analyzed for DEHA using a method based on solvent and dispersive solid-phase extraction and gas chromatography-mass spectrometry. These 26 food composites include cheese, meat, poultry, fish, and fast foods, and PVC films were likely used in packaging the individual foods used to make the composites. DEHA was detected in most of the meat, poultry, and fish composite samples, with the highest concentration found in ground beef (11 μg/g), followed by beef steak (9.9 μg/g), freshwater fish (7.8 μg/g), poultry liver pâté (7.4 μg/g), fresh pork (6.9 μg/g), cold cuts and luncheon meats (2.8 μg/g), veal cutlets (2.1 μg/g), roast beef (1.3 μg/g), lamb (1.2 μg/g), and organ meats (0.20 μg/g). Targeted surveys should be conducted to investigate the presence of DEHA in various foods packaged with PVC films in more detail and provide updated occurrence data for accurate human exposure assessment.

  7. Di (2-ethylhexyl) phthalate impairs steroidogenesis in ovarian follicular cells of prepuberal mice.

    PubMed

    Lai, Fang-Nong; Liu, Jing-Cai; Li, Lan; Ma, Jun-Yu; Liu, Xue-Lian; Liu, Yu-Ping; Zhang, Xi-Feng; Chen, Hong; De Felici, Massimo; Dyce, Paul W; Shen, Wei

    2017-03-01

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer which is widely used in the manufacture of plastics. As a common environmental contaminant and recognized endocrine disrupting chemical, DEHP is able to deregulate the functions of a variety of tissues, including the reproductive system both in males and females. In order to investigate the possible effects of DEHP on the first wave of folliculogenesis, occurring in the mouse ovary postnatally, mice were administered 20 or 40 μg/kg DEHP through intraperitoneal injection at days 5, 10 and 15 post partum (dpp). Following DEHP treatment the gene expression profile of control and exposed ovaries was compared by microarray analyses at 20 dpp. We found that in the exposed ovaries DEHP significantly altered the transcript levels of several immune response and steroidogenesis associated genes. In particular, DEHP significantly decreased the expression of genes essential for androgen synthesis by theca cells including Lhcgr, Cyp17a1, Star and Ldlr. Immunohistochemistry and immune flow cytometry confirmed reduced expression of LHCGR and CYP17A1 proteins in the exposed theca cells. These effects were associated to a significant reduction in ovarian concentrations of progesterone, 17β-estradiol and androstenedione along with a reduction of LH in the serum. Although we did not find a significant reduction of the number of primary, secondary or antral follicles in the DEHP exposed ovaries when compared to controls, we did observe that theca cells showed an altered structure of the nuclear envelope, fewer mitochondria, and mitochondria with a reduced number of cristae. Collectively, these results demonstrate a deleterious effect of DEHP exposure on ovarian steroidogenesis during the first wave of folliculogenesis that could potentially affect the correct establishment of the hypothalamic-pituitary-ovarian axis and the onset of puberty.

  8. In Utero Exposure to Di-(2-Ethylhexyl) Phthalate Decreases Mineralocorticoid Receptor Expression in the Adult Testis

    PubMed Central

    Martinez-Arguelles, D. B.; Culty, M.; Zirkin, B. R.; Papadopoulos, V.

    2009-01-01

    In utero exposure to di-(2-ethylhexyl) phthalate (DEHP) has been shown to result in decreased androgen formation by fetal and adult rat testes. In the fetus, decreased androgen is accompanied by the reduced expression of steroidogenic enzymes. The mechanism by which in utero exposure results in reduced androgen formation in the adult, however, is unknown. We hypothesized that deregulation of the nuclear steroid receptors might explain the effects of in utero DEHP exposure on adult testosterone production. To test this hypothesis, pregnant Sprague Dawley dams were gavaged with 100–950 mg DEHP per kilogram per day from gestational d 14–19, and testes were collected at gestational d 20 and postnatal days (PND) 3, 21, and 60. Among the nuclear receptors studied, the mineralocorticoid receptor (MR) mRNA and protein levels were reduced in PND60 interstitial Leydig cells, accompanied by reduced mRNA expression of MR-regulated genes. Methylation-sensitive PCR showed effects on the nuclear receptor subfamilies NR3A and -3C, but only MR was affected at PND60. Pyrosequencing of two CpG islands within the MR gene promoter revealed a loss of methylation in DEHP-treated animals that was correlated with reduced MR. Because MR activation is known to stimulate Leydig cell testosterone formation, and MR inhibition to be repressive, our results are consistent with the hypothesis that in utero exposure to DEHP leads to MR dysfunction and thus to depressed testosterone production in the adult. We suggest that decreased MR, possibly epigenetically mediated, is a novel mechanism by which phthalates may affect diverse functions later in life. PMID:19819939

  9. Quercetin attenuates di-(2-ethylhexyl) phthalate-induced testicular toxicity in adult rats.

    PubMed

    Abd-Ellah, M F; Aly, H A A; Mokhlis, H A M; Abdel-Aziz, A H

    2016-03-01

    The aim of the present study was to investigate the potential oxidative damage of di-(2-ethylhexyl) phthalate (DEHP) in the rat testis and to further elucidate the potential modulatory effect of quercetin. DEHP was diluted in corn oil and given to rats by oral gavage at doses 0, 300, 600, and 900 mg/kg/day (groups I, III, IV, or V, respectively) for 15 consecutive days. Group VI was pretreated with quercetin (90 mg/kg), 24 h before starting the experiment and then treated with DEHP (900 mg/kg/day) for 15 consecutive days. Group II was treated with quercetin (90 mg/kg/day). The relative testes weight and sperm motility were significantly decreased by treatment with 900 mg/kg of DEHP. Both sperm count and daily sperm production were significantly decreased by DEHP treatment at doses of 600 and 900 mg/kg. Serum testosterone level and prostatic acid phosphatase (ACP) activity and testicular lactate dehydrogenase-X (LDH-X) activity were significantly decreased in animals treated with 900 mg/kg. Serum total ACP activity was significantly increased in animals treated with 600 and 900 mg/kg of DEHP. DEHP treatment induced oxidative stress and histopathological abnormality. These abnormalities were effectively normalized by pretreatment with quercetin except for LDH-X near normalcy. In conclusion, the findings of this study demonstrate that DEHP impairs testicular function at least, in part, by inducing oxidative stress and quercetin has a potent protective effect against DEHP-induced testicular toxicity in rats.

  10. Di (2-ethylhexyl) Phthalate Exposure Impairs Growth of Antral Follicle in Mice

    PubMed Central

    Li, Lan; Liu, Jing-Cai; Lai, Fang-Nong; Liu, Huan-Qi; Zhang, Xi-Feng; Dyce, Paul W.; Shen, Wei; Chen, Hong

    2016-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp) to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative) related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice. PMID:26845775

  11. Progress in the removal of di-[2-ethylhexyl]-phthalate as plasticizer in blood bags.

    PubMed

    Simmchen, Juliane; Ventura, Rosa; Segura, Jordi

    2012-01-01

    Polyvinylchloride (PVC) is used in blood component containers as well as in many other medical devices because it shows optimal inertness, durability, and resistance to heat and chemicals. However, the polymer itself does not provide good handling characteristics or the necessary properties for red blood cell (RBC) survival. PVC thus needs to be plasticized, and di-(2-ethylhexyl)phthalate (DEHP) has been the most common plasticizer to produce the required flexibility to PVC. However, DEHP has been found to leach out from the containers, causing toxic effects, as demonstrated mainly in rodents. It is considered to be a possible carcinogen and suspected to also produce endocrine effects especially in young males. Although controversial, it is commonly accepted that in vulnerable patients such as newborns, trauma patients, or pregnant women, high exposure to DEHP should be avoided. The replacement of the common PVC + DEHP blood bags poses technical challenges due to the positive influence of the DEHP molecules on the red blood cell (RBC) membrane, and thus it has been shown to affect RBC storage and survival after transfusion. Different approaches are thus being taken to find a suitable alternative to DEHP for blood components bags. Environmentalists even favor the substitution of the PVC to avoid not only the plasticizers but even the other residues contained in the polymer material. Consequently, whereas the simplest solution is the substitution of the DEHP by other plasticizers, alternative plasticizer-free materials are becoming explored. Even modifications of existing materials are being presented by some research groups, ranging from covering of the DEHP-containing materials to alloys or special additive solutions. Different strategies as well as the most promising approaches are presented in this review. In any case, the degree of stabilization of RBCs undergoing prolonged storage will dictate the final acceptance for such alternatives.

  12. Effects of Di-(2-ethylhexyl) Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats

    PubMed Central

    Liu, Te; Jia, Yiyang; Zhou, Liting; Wang, Qi; Sun, Di; Xu, Jin; Wu, Juan; Chen, Huaiji; Xu, Feng; Ye, Lin

    2016-01-01

    The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1) higher gonadotropin-releasing hormone (GnRH) level in the hypothalamus; (2) higher protein levels of GnRH in the hypothalamus; and (3) higher mRNA and protein levels of GnRH receptor (GnRHR) in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats. PMID:27845755

  13. Kinetics of di-(2-ethylhexyl)phthalate mineralization in sludge-amended soil

    SciTech Connect

    Madsen, P.L.; Thyme, J.B.; Henriksen, K.; Moeldrup, P.; Roslev, P. . Environmental Engineering Lab.)

    1999-08-01

    Sewage sludge is frequently used as a soil fertilizer although it may contain elevated concentrations of priority pollutants including di-(2-ethylhexyl)phthalate (DEHP). In the present study, the kinetics of microbial [[sup 14]C]DEHP mineralization was studied in laboratory microcosms with sewage sludge and agricultural soil. A biphasic model with two independent kinetic expressions was used to fit the mineralization data. The initial mineralization activity was described well by first-order kinetics, whereas mineralization in long-term incubations was described better by fractional power kinetics. The mineralization activity was much lower in the late phase presumably due to a decline in the bioavailability of DEHP caused by diffusion-limited desorption. The initial DEHP mineralization rate in sludge-amended soil varied between 3.7 and 20.3 ng of DEHP (g dw)[sup [minus]1]d[sup [minus]1] depending on incubation conditions. Aerobic DEHP mineralization was 4--5 times faster than anaerobic mineralization, DEHP mineralization in sludge-amended soil was much more temperature sensitive than was DEHP mineralization in soil without sludge. Indigenous microorganisms in the sewage sludge appeared to dominate DEHP degradation in sludge-amended soil. It was estimated that > 41% of the DEHP in sludge-amended soil will have escaped mineralization after 1 year. In the absence of oxygen, > 68% of the DEHP will not be mineralized within 1 year. Collectively, the data suggest that a significant fraction of the DEHP in sludge-amended soils may escape mineralization under in situ conditions.

  14. Maternal di-(2-ethylhexyl)-phthalate exposure influences essential fatty acid homeostasis in rat placenta.

    PubMed

    Xu, Y; Agrawal, S; Cook, T J; Knipp, G T

    2008-11-01

    Maintaining essential fatty acid (EFA) homeostasis during pregnancy is critical for fetal development. As the organ that controls the maternal-to-fetal supply of nutrients, the placenta plays a significant role in guiding EFA transfer to the fetus. Many EFA homeostasis proteins are regulated by peroxisome proliferator-activated receptors (PPARs). The metabolites of di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous environmental contaminant, might influence EFA homeostasis via trans-activation of PPARs with subsequent downstream effects on EFA transporters and enzymes. To investigate DEHP's effect on placental/fetal EFA homeostasis, female Sprague-Dawley rats were orally gavaged with either vehicle or DEHP at 750 or 1500 mg/kg/day from gestational day (GD) 0 to GD 19. Changes in the expression of several EFA homeostasis regulating proteins were determined in the junctional (JXN) and labyrinthine (LAB) zones of the placenta, including PPAR isoforms (alpha, beta and gamma), fatty acid translocase (FAT/CD36), fatty acid transport protein 1 (FATP1), plasma membrane fatty acid binding protein (FABPpm), heart cytoplasmic fatty acid binding protein (HFABP), cytochrome P450 (CYP) 4A1, and cyclooxygenase (COX)-1 and -2. Additionally, effects of DEHP maternal exposure on the placental transfer and fetal distribution of representative EFAs, arachidonic acid (AA) and docosahexaenoic acid (DHA), and the placental production of prostaglandins (PGs) were investigated. Expression of PPARalpha, PPARgamma, FAT/CD36, FATP1, HFABP and CYP4A1 was up-regulated in JXN and/or LAB while COX-2 was down-regulated in JXN. PPARbeta, FABPpm, and COX-1 demonstrated variable expression. Reduced directional maternal-to-fetal placental transfer and altered fetal distribution of AA and DHA were observed in concordance with a decreased total placental PG production. These results correlate with previous in vitro data, suggesting that DEHP could influence placental EFA homeostasis with potential

  15. Mono-2-ethylhexyl phthalate associated with insulin resistance and lower testosterone levels in a young population.

    PubMed

    Chen, Szu-Ying; Hwang, Jing-Shiang; Sung, Fung-Chang; Lin, Chien-Yu; Hsieh, Chia-Jung; Chen, Pau-Chung; Su, Ta-Chen

    2017-06-01

    Phthalates are commonly used as plasticizers and are reported to associate with testicular dysfunction or insulin resistance in different studies, but the concurrent relationship between phthalate exposure, testosterone levels, and insulin resistance in the young population is not well understood. We recruited 786 subjects aged 12-30 years from a population-based sample of Taiwanese adolescents and young adults from 2006 to 2008. Generalized additive models were used to evaluate glucose homeostasis and testicular function in relation to seven urinary phthalate metabolites among adolescents (aged 12-20) and young adults (aged 20-30) in Taiwan. We observed a trend toward a decrease in male testosterone and an increase in urinary mono-2-ethylhexyl phthalate (MEHP) levels across four quartiles of homeostasis model assessment of insulin resistance (HOMA-IR). After adjusting for potential covariates, generalized additive models further showed that log-transformed insulin and HOMA-IR were raised by 0.055 [95% confidence interval (CI), 0.027-0.082] and 0.056 (95% CI, 0.027-0.084), respectively, with a one-unit increase in log-transformed MEHP in young adults. In male adults (aged 22-30), the log-testosterone levels were reduced by 0.018 (95% CI, 0.001-0.036), with a one-unit of increase in log-transformed MEHP. Such relationships were not observed in adolescents. In conclusion, this study demonstrated age-related associations of urinary MEHP metabolites with impaired metabolic homeostasis of glucose that were only observed in young adults. In addition, MEHP exposure was concurrently associated with lower testosterone levels in young, male adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The endocrine disruptor mono-(2-ethylhexyl) phthalate affects the differentiation of human liposarcoma cells (SW 872).

    PubMed

    Campioli, Enrico; Batarseh, Amani; Li, Jiehan; Papadopoulos, Vassilios

    2011-01-01

    Esters of phthalic acid (phthalates) are largely used in industrial plastics, medical devices, and pharmaceutical formulations. They are easily released from plastics into the environment and can be found in measurable levels in human fluids. Phthalates are agonists for peroxisome proliferator-activated receptors (PPARs), through which they regulate translocator protein (TSPO; 18 kDa) transcription in a tissue-specific manner. TSPO is a drug- and cholesterol-binding protein involved in mitochondrial respiration, steroid formation, and cell proliferation. TSPO has been shown to increase during differentiation and decrease during maturation in mouse adipocytes. The purpose of this study was to establish the effect of mono-(2-ethylhexyl) phthalate (MEHP) on the differentiation of human SW 872 preadipocyte cells, and examine the role of TSPO in the process. After 4 days of treatment with 10 µM MEHP, we observed changes in the transcription of acetyl-CoA carboxylase alpha, adenosine triphosphate citrate lyase, glucose transporters 1 and 4, and the S100 calcium binding protein B, all of which are markers of preadipocyte differentiation. These observed gene expression changes coincided with a decrease in cellular proliferation without affecting cellular triglyceride content. Taken together, these data suggest that MEHP exerts a differentiating effect on human preadipocytes. Interestingly, MEHP was able to temporarily increase TSPO mRNA levels through the PPAR-α and β/δ pathways. These results suggest that TSPO can be considered an important player in the differentiation process itself, or alternatively a factor whose presence is essential for adipocyte development.

  17. Mono-2-ethylhexyl phthalate (MEHP) alters histiotrophic nutrition pathways and epigenetic processes in the developing conceptus.

    PubMed

    Sant, Karilyn E; Dolinoy, Dana C; Jilek, Joseph L; Shay, Brian J; Harris, Craig

    2016-01-01

    Histiotrophic nutrition pathways (HNPs) are processes by which the organogenesis-stage conceptus obtains nutrients, amino acids, vitamins and cofactors required for protein biosynthesis and metabolic activities. Nutrients are captured from the maternal milieu as whole proteins and cargoes via receptor-mediated endocytosis in the visceral yolk sac (VYS), degraded by lysosomal proteolysis and delivered to the developing embryo (EMB). Several nutrients obtained by HNPs are required substrates for one-carbon (C1) metabolism and supply methyl groups required for epigenetic processes, including DNA and histone methylation. Increased availability of methyl donors has been associated with reduced risk for neural tube defects (NTDs). Here, we show that mono-2-ethylhexyl phthalate (MEHP) treatment (100 or 250μM) alters HNPs, C1 metabolism and epigenetic programming in the organogenesis-stage conceptus. Specifically, 3-h MEHP treatment of mouse EMBs in whole culture resulted in dose-dependent reduction of HNP activity in the conceptus. To observe nutrient consequences of decreased HNP function, C1 components and substrates and epigenetic outcomes were quantified at 24h. Treatment with 100-μM MEHP resulted in decreased dietary methyl donor concentrations, while treatment with 100- or 250-μM MEHP resulted in dose-dependent elevated C1 products and substrates. In MEHP-treated EMBs with NTDs, H3K4 methylation was significantly increased, while no effects were seen in treated VYS. DNA methylation was reduced in MEHP-treated EMB with and without NTDs. This research suggests that environmental toxicants such as MEHP decrease embryonic nutrition in a time-dependent manner and that epigenetic consequences of HNP disruption may be exacerbated in EMB with NTDs. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Di (2-ethylhexyl) phthalate inhibits growth of ovarian antral follicles through an oxidative stress pathway

    PubMed Central

    Wang, Wei; Craig, Zelieann R.; Basavarajappa, Mallikarjuna S.; Gupta, Rupesh; Flaws, Jodi A.

    2011-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 32–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. PMID:22155089

  19. Di-(2-ethylhexyl) Phthalate-Induced Hippocampus-Derived Neural Stem Cells Proliferation

    PubMed Central

    Abdanipour, Alireza; Noori-Zadeh, Ali; Mesbah-Namin, Seyed Alireza; Bakhtiyari, Salar; Nejatbakhsh, Reza; Anarkooli, Iraj Jafari

    2017-01-01

    The brain and spinal cord have a limited capacity for self-repair under damaged conditions. One of the best options to overcome these limitations involves the use of phytochemicals as potential therapeutic agents. In this study, we have aimed to investigate the effects of di-(2-ethylhexyl) phthalate (DEHP) on hippocampus-derived neural stem cells (NSCs) proliferation to search phytochemical candidates for possible treatment of neurological diseases using endogenous capacity. In this experimental study, neonatal rat hippocampus-derived NSCs were cultured and treated with various concentrations of DEHP (0, 100, 200, 400 and 600 µM) and Cirsium vulgare (C. vulgare) hydroethanolic extract (0, 200, 400, 600, 800 and 1000 µg/ml) for 48 hours under in vitro conditions. Cell proliferation rates and quantitative Sox2 gene expression were evaluated using MTT assay and real-time reverse transcription polymerase chain reaction (RT-PCR). We observed the highest average growth rate in the 400 µM DEHP and 800 µg/ml C. vulgare extract treated groups. Sox2 expression in the DEHP-treated NSCs significantly increased compared to the control group. Gas chromatography/mass spectrometry (GC/ MS) results demonstrated that the active ingredients that naturally occurred in the C. vulgare hydroethanolic extract were 2-ethyl-1-hexanamine, n-heptacosane, 1-cyclopentanecarboxylic acid, 1-heptadecanamine, 2,6-octadien-1-ol,2,6,10,14,18,22-tetracosahexaene, and DEHP. DEHP profoundly stimulated NSCs proliferation through Sox2 gene overexpression. These results provide and opportunity for further use of the C. vulgure phytochemicals for prevention and/or treatment of neurological diseases via phytochemical mediated-proliferation of endogenous adult NSCs.

  20. Effects of Di-(2-ethylhexyl) Phthalate on the Hypothalamus-Uterus in Pubertal Female Rats.

    PubMed

    Liu, Te; Jia, Yiyang; Zhou, Liting; Wang, Qi; Sun, Di; Xu, Jin; Wu, Juan; Chen, Huaiji; Xu, Feng; Ye, Lin

    2016-11-12

    The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children's toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus-uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1) higher gonadotropin-releasing hormone (GnRH) level in the hypothalamus; (2) higher protein levels of GnRH in the hypothalamus; and (3) higher mRNA and protein levels of GnRH receptor (GnRHR) in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus-uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats.

  1. The Endocrine Disruptor Mono-(2-Ethylhexyl) Phthalate Affects the Differentiation of Human Liposarcoma Cells (SW 872)

    PubMed Central

    Campioli, Enrico; Batarseh, Amani; Li, Jiehan; Papadopoulos, Vassilios

    2011-01-01

    Esters of phthalic acid (phthalates) are largely used in industrial plastics, medical devices, and pharmaceutical formulations. They are easily released from plastics into the environment and can be found in measurable levels in human fluids. Phthalates are agonists for peroxisome proliferator-activated receptors (PPARs), through which they regulate translocator protein (TSPO; 18 kDa) transcription in a tissue-specific manner. TSPO is a drug- and cholesterol-binding protein involved in mitochondrial respiration, steroid formation, and cell proliferation. TSPO has been shown to increase during differentiation and decrease during maturation in mouse adipocytes. The purpose of this study was to establish the effect of mono-(2-ethylhexyl) phthalate (MEHP) on the differentiation of human SW 872 preadipocyte cells, and examine the role of TSPO in the process. After 4 days of treatment with 10 µM MEHP, we observed changes in the transcription of acetyl-CoA carboxylase alpha, adenosine triphosphate citrate lyase, glucose transporters 1 and 4, and the S100 calcium binding protein B, all of which are markers of preadipocyte differentiation. These observed gene expression changes coincided with a decrease in cellular proliferation without affecting cellular triglyceride content. Taken together, these data suggest that MEHP exerts a differentiating effect on human preadipocytes. Interestingly, MEHP was able to temporarily increase TSPO mRNA levels through the PPAR-α and β/δ pathways. These results suggest that TSPO can be considered an important player in the differentiation process itself, or alternatively a factor whose presence is essential for adipocyte development. PMID:22205965

  2. Effects of mono-(2-ethylhexyl) phthalate (MEHP) on chicken germ cells cultured in vitro.

    PubMed

    Guibert, Edith; Prieur, Bérénice; Cariou, Ronan; Courant, Frédérique; Antignac, Jean Philippe; Pain, Bertrand; Brillard, Jean Pierre; Froment, Pascal

    2013-05-01

    In recent decades, many toxicological tests based on in vivo or in vitro models, mainly from mammalian (rat-mouse) and fish species, were used to assess the risks raised by contact or ingestion of molecules of pharmaceutical, agricultural, or natural origin. But no, or few, in vitro tests using other non-mammalian models such as bird have been explored despite their advantages: the embryonic gonads of birds have a high plasticity of development sensitive to estrogen, and sperm production is nearly two times faster than in rodents. Hence, we have established an in vitro culture of germ cells and somatic cells from chicken post-natal testis, and we have evaluated the sensitivity against the endocrine disruptor compound mono-(2-ethylhexyl) phthalate (MEHP) in comparison to previous studies using rodent and human models. After 96 h of exposure in presence of 10 μM MEHP, chicken seminiferous tubules cultures present a structural alteration, a reduction in cell proliferation and in germ cells population. Apoptosis of germ and somatic cells increases in presence of 1 μM MEHP. Furthermore, MEHP does not affect inhibin B and lactate production by Sertoli cells. These results are in accordance with previous studies using rat, mice, or human culture of testicular cells and in similar range of exposures or even better sensitivity for some "end-points" (biological parameters). In conclusion, the establishment of this postnatal testicular cells culture could be considered as an alternative method to in vivo experiments frequently used for evaluating the impact on the terrestrial wildlife species. This method could be also complementary to mammal model due to the limiting number of animals used and its elevated sensitivity.

  3. Transgenerational Effects of Di-(2-Ethylhexyl) Phthalate (DEHP) on Stress Hormones and Behavior.

    PubMed

    Quinnies, Kayla M; Doyle, Timothy J; Kim, Kwan Hee; Rissman, Emilie F

    2015-09-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) has been linked to male reproductive abnormalities. Here, we assessed transgenerational actions of DEHP on several behaviors and stress responses. We used 2 doses of DEHP (150- and 200-mg/kg body weight) and a treatment regimen previously shown to produce transgenerational effects on male reproduction. Mice, 3 generations removed from DEHP exposure (F3), were tested for social behavior and anxiety on the elevated plus maze. We collected blood and pituitaries from undisturbed and restrained mice. Body weights, anogenital distances, and reproductive organ weights were collected at killing. In social interaction tests juvenile males from the DEHP lineage (200 mg/kg) displayed more digging and less self-grooming than did controls. Interestingly, 150-mg/kg lineage males, killed in early puberty, had smaller seminal vesicle weights than their controls. However, the 200-mg/kg males (killed on average 10 d later) did not show this effect. Females from a DEHP lineage had lower corticosterone concentrations than controls after restraint stress. We also found sex- and DEHP-specific mRNA expression changes in the pituitary in 2 of the 6 stress-related genes we measured. In particular, Gnas mRNA was elevated by the combination of DEHP lineage and stress. Thus, transgenerational effects of DEHP are noted in male behavior, and in females, DEHP had transgenerational effects on levels of corticosterone. Both of these results may be related to transgenerational modifications in the expression of several pituitary hormones involved in the hypothalamic-pituitary-adrenal axis.

  4. Degradation of Phthalate and Di-(2-Ethylhexyl)phthalate by Indigenous and Inoculated Microorganisms in Sludge-Amended Soil

    PubMed Central

    Roslev, Peter; Madsen, Peter L.; Thyme, Jesper B.; Henriksen, Kaj

    1998-01-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl)phthalate (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP (4.1 nmol/g [dry weight]) were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [14C]PA and [14C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [14C]DEHP to 14CO2 increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of 14C-labelled phospholipid ester-linked fatty acids (14C-PLFAs). This assay provided a radioactive fingerprint of the organisms actively metabolizing [14C]PA and [14C]DEHP. The 14C-PLFA fingerprints showed that organisms with different PLFA compositions metabolized PA and DEHP in sludge-amended soil. In contrast, microorganisms with comparable 14C-PLFA fingerprints were found to dominate DEHP metabolism in sludge and sludge-amended soil. Our results suggested that indigenous sludge microorganisms dominated DEHP degradation in sludge-amended soil. Mineralization of DEHP and PA followed complex kinetics that could not be described by simple first-order equations. The initial mineralization activity was described by an exponential function; this was followed by a second phase that was described best by a fractional power function. In the initial phase, the half times for PA and DEHP in sludge

  5. Mechanisms of toxicity of di(2-ethylhexyl) phthalate on the reproductive health of male zebrafish.

    PubMed

    Uren-Webster, Tamsyn M; Lewis, Ceri; Filby, Amy L; Paull, Gregory C; Santos, Eduarda M

    2010-09-01

    Phthalates are ubiquitous in the aquatic environment and are known to adversely affect male reproductive health in mammals through interactions with multiple receptor systems. However, little is known about the risks they pose to fish. This project investigated the effects of di(2-ethylhexyl) phthalate (DEHP), the most commonly used phthalate, on the reproductive health of male zebrafish (Danio rerio). Males were treated with 0.5, 50 and 5000 mg DEHP kg(-1) (body weight) for a period of 10 days via intraperitoneal injection. The effects of the exposure were assessed by analysing fertilisation success, testis histology, sperm DNA integrity and transcript profiles of the liver and testis. A significant increase in the hepatosomatic index and levels of hepatic vitellogenin transcript were observed following exposure to 5000 mg DEHP kg(-1). Exposure to 5000 mg DEHP kg(-1) also resulted in a reduction in fertilisation success of oocytes spawned by untreated females. However, survival and development of the resulting embryos were unaffected by all treatments, and no evidence of DEHP-induced sperm DNA damage was observed. Exposure to 50 and 5000 mg DEHP kg(-1) caused alterations in the proportion of germ cells at specific stages of spermatogenesis in the testis, including a reduction in the proportion of spermatozoa and an increase in the proportion of spermatocytes, suggesting that DEHP may inhibit the progression of meiosis. In parallel, exposure to 5000 mg DEHP kg(-1) increased the levels of two peroxisome proliferator-activated receptor (PPAR) responsive genes (acyl-coenzyme A oxidase 1 (acox1) and enoyl-coenzyme A, hydratase/3-hydroxyacyl coenzyme A dehydrogenase (ehhadh). These data demonstrated that exposure to high concentrations of DEHP disrupts spermatogenesis in adult zebrafish with a consequent decrease in their ability to fertilise oocytes spawned by untreated females. Furthermore, our data suggest that the adverse effects caused by exposure to DEHP are

  6. Mechanistic considerations for human relevance of cancer hazard of di(2-ethylhexyl) phthalate.

    PubMed

    Rusyn, Ivan; Corton, J Christopher

    2012-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and environmental (medical devices, contamination of food, or intake from air, water and soil) routes of exposure to DEHP are of concern for human health. There is sufficient evidence for carcinogenicity of DEHP in the liver in both rats and mice; however, there is little epidemiological evidence on possible associations between exposure to DEHP and liver cancer in humans. Data are available to suggest that liver is not the only target tissue for DEHP-associated toxicity and carcinogenicity in both humans and rodents. The debate regarding human relevance of the findings in rats or mice has been informed by studies on the mechanisms of carcinogenesis of the peroxisome proliferator class of chemicals, including DEHP. Important additional mechanistic information became available in the past decade, including, but not limited to, sub-acute, sub-chronic and chronic studies with DEHP in peroxisome proliferator-activated receptor (PPAR) α-null mice, as well as experiments utilizing several transgenic mouse lines. Activation of PPARα and the subsequent downstream events mediated by this transcription factor represent an important mechanism of action for DEHP in rats and mice. However, additional data from animal models and studies in humans exposed to DEHP from the environment suggest that multiple molecular signals and pathways in several cell types in the liver, rather than a single molecular event, contribute to the cancer in rats and mice. In addition, the toxic and carcinogenic effects of DEHP are not limited to liver. The International Agency for Research on Cancer working group concluded that the human relevance of the molecular events leading to cancer elicited by DEHP in several target tissues (e

  7. Metabolites of organophosphate flame retardants and 2-ethylhexyl tetrabromobenzoate in urine from paired mothers and toddlers.

    PubMed

    Butt, Craig M; Congleton, Johanna; Hoffman, Kate; Fang, Mingliang; Stapleton, Heather M

    2014-09-02

    As a result of the polybrominated diphenyl ether (PBDE) ban in the mid-2000s, the chemical flame retardant market has moved toward alterative compounds including chlorinated alkyl and nonchlorinated aryl organophosphate flame retardants (OPFRs) as well as aromatic brominated compounds such as Firemaster 550 (FM550). Recent studies have shown that the OPFRs and Firemaster 550 components are frequently detected in polyurethane foams and in indoor dust. Some OPFRs are considered carcinogenic and/or neurodevelopmental toxicants, and children's exposure to these compounds is a concern. OPFRs are readily metabolized and excreted in the urine as their dialkyl and diaryl compounds which function as biomarkers for OPFR exposure. Limited research has shown that adults are broadly exposed to OPFRs, but nothing is known about children's exposure. Similarly, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), a FM550 component, is metabolized to tetrabromobenzoic acid (TBBA). The current study measured levels of bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(1-chloro-2-propyl) phosphate (BCIPP), diphenyl phosphate (DPHP), 2 alkylated DPHPs, and TBBA in urine collected in 2013 from 21 US mother-toddler pairs. BDCIPP, DPHP, and ip-DPHP were detected in 100%, 98%, and 96% of all individuals, whereas BCIPP and tert-butyl-DPHP (tb-DPHP) were only detected in 8% and 13%. Further, TBBA was detected in 27% of adults but 70% of children. Overall, children had higher urinary levels of BDCIPP, DPHP, ip-DPHP, and TBBA as compared to their mothers, suggesting higher exposure. For example, on average, BDCIPP levels in children were 4.9 times those of mothers. BDCIPP and DPHP levels in mother's urine were also significantly correlated with levels in children's urine, suggesting similar exposure routes, likely in the home environment. Various potential predictors of OPFR exposure were assessed using a questionnaire. In children some predictors of hand-mouth exposure were associated with

  8. Adsorption of sodium bis(2-ethylhexyl) sulfosuccinate and wettability in polytetrafluoroethylene solution air system

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2007-06-01

    The role of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) adsorption at water-air and polytetrafluoroethylene-water (PTFE) interfaces in wetting of low energy PTFE was established from measurements of the contact angle of aqueous AOT solutions in PTFE-solution drop-air systems and the aqueous AOT solution surface tension measurements. For calculations of the adsorption at these interfaces the relationship between adhesion tension ( γLV cos θ) and surface tension ( γLV), and the Gibbs and Young equations were taken into account. On the basis of the measurements and calculations the slope of the γLV cos θ- γLV curve was found to be constant and equal -1 over the whole range of surfactant concentration in solution. It means that the amount of surfactant adsorbed at the PTFE-water interface, ΓSL, is essentially equal to its amount adsorbed at water-air interface, ΓLV. By extrapolating the linear dependence between γLV cos θ and γLV to cos θ = 1 the determined value of critical surface tension of PTFE surface wetting, γC, was obtained (23.6 mN/m), and it was higher than the surface tension of PTFE (20.24 mN/m). Using the value of PTFE surface tension and the measured surface tension of aqueous AOT solution in Young equation, the PTFE-solution interface tension, γSL, was also determined. The shape of the γSL-log C curve occurred to be similar to the isotherm of AOT adsorption at water-air interface, and a linear dependence existed between the PTFE-solution interfacial tension and polar component of aqueous AOT solution. The dependence was found to be established by the fact that the work of adhesion of AOT solution to the PTFE surface was practically constant amounting 46.31 mJ/m 2 which was close to the work of water adhesion to PTFE surface.

  9. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    SciTech Connect

    Wang, Wei Craig, Zelieann R. Basavarajappa, Mallikarjuna S. Gupta, Rupesh K. Flaws, Jodi A.

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  10. MECHANISTIC CONSIDERATIONS FOR HUMAN RELEVANCE OF CANCER HAZARD OF DI(2-ETHYLHEXYL) PHTHALATE

    PubMed Central

    Rusyn, Ivan; Corton, J. Christopher

    2012-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator agent that is widely used as a plasticizer to soften polyvinylchloride plastics and non-polymers. Both occupational (e.g., by inhalation during its manufacture and use as a plasticizer of polyvinylchloride) and environmental (medical devices, contamination of food, or intake from air, water and soil) routes of exposure to DEHP are of concern for human health. There is sufficient evidence for carcinogenicity of DEHP in the liver in both rats and mice; however, there is little epidemiological evidence on possible associations between exposure to DEHP and liver cancer in humans. Data are available to suggest that liver is not the only target tissue for DEHP-associated toxicity and carcinogenicity in both humans and rodents. The debate regarding human relevance of the findings in rats or mice has been informed by studies on the mechanisms of carcinogenesis of the peroxisome proliferator class of chemicals, including DEHP. Important additional mechanistic information became available in the past decade, including, but not limited to, sub-acute, sub-chronic and chronic studies with DEHP in peroxisome proliferator-activated receptor (PPAR) α-null mice, as well as experiments utilizing several transgenic mouse lines. Activation of PPARα and the subsequent downstream events mediated by this transcription factor represent an important mechanism of action for DEHP in rats and mice. However, additional data from animal models and studies in humans exposed to DEHP from the environment suggest that multiple molecular signals and pathways in several cell types in the liver, rather than a single molecular event, contribute to the cancer in rats and mice. In addition, the toxic and carcinogenic effects of DEHP are not limited to liver. The International Agency for Research on Cancer working group concluded that the human relevance of the molecular events leading to cancer elicited by DEHP in several target tissues (e

  11. In Vitro Metabolism of the Brominated Flame Retardants 2-Ethylhexyl-2,3,4,5-Tetrabromobenzoate (TBB) and Bis(2-Ethylhexyl) 2,3,4,5-Tetrabromophthalate (TBPH) in Human and Rat Tissues

    PubMed Central

    Roberts, Simon C.; Macaulay, Laura J.; Stapleton, Heather M.

    2012-01-01

    Due to the phaseout of polybrominated diphenyl ether (PBDE) flame retardants, new chemicals, such as 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 2,3,4,5-tetrabromophthalate (TBPH), have been used as replacements in some commercial flame retardant mixtures. Both chemicals have been detected in indoor dust at concentrations approaching the concentrations of PBDEs; however, little is known about their fate, metabolism, or toxicity. The goal of this study was to investigate the potential metabolism of these two brominated flame retardants in human and rat tissues by conducting in vitro experiments with liver and intestinal subcellular fractions. In all the experiments, TBB was consistently metabolized to 2,3,4,5-tetrabromobenzoic acid (TBBA) via cleavage of the 2-ethylhexyl chain without requiring any added cofactors. TBBA was also formed in purified porcine carboxylesterase, but at a much faster rate of 6.29 ± 0.58 nmol min-1 mg protein-1. The estimated Km and Vmax values for TBB metabolism in human microsomes were 11.1 ± 3.9 μM and 0.644 ± 0.144 nmol min-1 mg protein-1, respectively. A similar Km of 9.3 ± 2.2 μM was calculated for porcine carboxylesterase, indicating similar enzyme specificity. While the rapid formation of TBBA may reduce the bioaccumulation potential of TBB in mammals and may be useful as a biomarker of TBB exposure, the toxicity of this brominated benzoic acid is unknown and may be a concern based on its structural similarity to other toxic pollutants. In contrast to TBB, no metabolites of TBPH were detected in human or rat subcellular fractions. However, a metabolic product of TBPH, mono(2-ethylhexyl) tetrabromophthalate (TBMEHP), was formed in purified porcine carboxylesterase at an approximate rate of 1.08 pmol min-1 mg protein-1. No Phase II metabolites of TBBA or TBMEHP were observed. More research is needed to understand the in vivo toxicokinetics and health effects of these compounds given their current

  12. Characterization and evaluation of poly(epsilon-caprolactone) nanoparticles containing 2-ethylhexyl-p-methoxycinnamate, octocrylene, and benzophenone-3 in anti-solar preparations.

    PubMed

    do Nascimento, Débora Freitas; Silva, Anna Claudia; Mansur, Claudia Regina Elias; Presgrave, Rosaura de Faria; Alves, Eloisa Nunes; Silva, Ronald Santos; Ricci-Júnior, Eduardo; de Freitas, Zaida Maria Faria; dos Santos, Elisabete Pereira

    2012-09-01

    Ultraviolet radiation can bring both harm and benefits to human health. Among those harms are erythemas, photosensitivity, photoaging, and the most worrying, skin cancer. Nanoencapsulation of sunscreen agents (SA) by using a biocompatible and biodegradable polymer such as poly(epsilon-caprolactone) (PCL) is advantageous as it increases the retention of UV absorbers in the skin, avoids systemic absorption, and consequently, improves water resistance and stability of the preparation. The aim of this work is to develop, characterize, and study the encapsulation of 3 different SA: 2-ethylhexyl-p-methoxycinnamate, benzophenone-3, and octocrylene in PCL nanoparticles (Nps). Nps were prepared by the solvent emulsification and evaporation method. The process yield was calculated, and the Nps were characterized in terms of size, polydispersity index (PI), morphology, zeta potential (ZP), encapsulation efficiency (EE) (%), and sunscreen agent content (SAC). The final formulations were submitted to the hen's egg test-chorioallantoic membrane (HET-CAM), chorioallantoic membrane-trypan blue staining (CAM-TBS), red blood cell (RBC), Draize tests, in vitro release, in vitro sun protection factor (SPF), UVA protection factor (PF-UVA), and photostability. All the Nps were in the nanometric scale. PI showed monodisperse systems. ZP became more negative as the Np were lyophilized and were added to the formulations. EE varied from 84 to 90%. The SAC went from 44 to 65 microg of sunscreen agents by milligram of Np. The process yield went from 60 to 76%. Nps were predominantly spherical and elliptical forms. The addition of Np diminished the release of the SA. The SPF increased with Np presence and helped to maintain the PF-UVA after irradiation. The HET-CAM assay evaluated the formulation as slightly irritant, CAM-TBS and RBC tests as non irritant, and the Draize test as moderately irritant.

  13. Modeling of facilitated transport of phenylalanine by emulsion liquid membranes with di(2-ethylhexyl)phosphoric acid as a carrier

    SciTech Connect

    Liu, X.; Liu, D.

    1998-12-01

    A mathematical model is developed in this paper to simulate the facilitated transport of phenylalanine (Phe) in emulsion liquid membrane (ELM) systems with di(2-ethylhexyl)phosphoric acid as a carrier. The model takes into account the mass transfer in both the external aqueous phase and the organic membrane phase interfacial reaction as well as membrane breakage during agitation. The model is tested by comparing theoretical predications with experimental results using Phe extraction by ELM processes. It is found that the model is valid for simulating the facilitated transport of Phe with ELM under various experimental conditions.

  14. Optical and electrical properties of inverted emulsions based on sodium bis(2-ethylhexyl) sulfosuccinate containing cadmium sulfide particles

    NASA Astrophysics Data System (ADS)

    Fedyaeva, O. A.; Poshelyuzhnaya, E. G.; Shubenkova, E. G.; Trenikhin, M. V.

    2017-03-01

    The optical and electrical properties of inverted emulsions based on sodium bis(2-ethylhexyl) sulfosuccinate (AOT) containing nanoparticles of cadmium sulfide are studied. The particle size of the synthesized samples is determined from UV spectroscopy data. The state of solubilized water in invert emulsions is found to change in the presence of cadmium sulfide due to the formation of aqua complexes. The shape of AOT micelles and the structures formed by drying the invert AOT emulsions are shown to be affected by the degree of hydration and the solubilization of CdS particles.

  15. Dispersion and ecological risk assessment of di (2-ethylhexyl) phthalate (DEHP) in the surface waters of Thailand.

    PubMed

    Sirivithayapakorn, Sanya; Thuyviang, Kanchana

    2010-05-01

    Previous environmental monitoring indicated that di (2-ethylhexyl) phthalate (DEHP) was released into the environment. This study collected both water and sediment samples from the source area, deltas of major rivers discharging into the Gulf of Thailand, and 2 tourist beaches from February 2007-August 2009. The analyses showed that the highest DEHP concentrations were 8.64 microg l(-1) and 14.51 microg g(-1) for water and suspended sediment samples, respectively. Nevertheless, the monitoring results indicated that the dispersion of DEHP was limited to the source area. The ecological risk assessment indicated that the ecological risk did not exceed the acceptable level for the current degree of contaminations.

  16. Decoupling of dynamic processes in surfactant-based liquid mixtures: the case of lithium-containing bis(2-ethylhexyl)phosphoric acid/bis(2-ethylhexyl)amine systems.

    PubMed

    Nicotera, Isabella; Oliviero Rossi, Cesare; Turco Liveri, Vincenzo; Calandra, Pietro

    2014-07-22

    Pure surfactant liquids and their binary mixtures, because of the amphiphilic nature of the molecules involved, can exhibit nanosegregation and peculiar transport properties. The idea that inspired this work is that the possibility of including in such media salts currently used for technological applications should lead to a synergy between the properties of the salt and those of the medium. Therefore, the dynamic features of bis(2-ethylhexyl)amine (BEEA) and bis(2-ethylhexyl)phosphoric acid (HDEHP) liquid mixtures were investigated as a function of composition and temperature by (1)H nuclear magnetic resonance (NMR) spectroscopy and rheometry. Inclusion of litium trifluoromethanesulfonate (LiT) has been investigated by infrared spectroscopy, pulsed field gradient NMR, and conductimetry methods to highlight the solubilizing and confining properties of these mixtures as well as the lithium conductivity. It was found that BEEA/HDEHP binary liquid mixtures show zero-threshold percolating self-assembly with a maximum in viscosity and a minimum in molecular diffusion at a 1:1 composition. Dissolution of LiT in such system can occur via confinement in the locally self-assembled polar domains. Despite this confinement, Li(+) conduction is scarcely dependent on the medium composition because of the possibility of a field-induced hopping decoupled by the structural and dynamical features of the medium.

  17. Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine.

    PubMed

    Eckert, Elisabeth; Münch, Frank; Göen, Thomas; Purbojo, Ariawan; Müller, Johannes; Cesnjevar, Robert

    2016-02-01

    Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures.

  18. Detection, identification, and quantification of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate isomers in house dust.

    PubMed

    Peng, Hui; Saunders, David M V; Sun, Jianxian; Codling, Garry; Wiseman, Steve; Jones, Paul D; Giesy, John P

    2015-03-03

    Ultra-High Resolution LC/mass spectrometry (LC-UHRMS; Thermo Fisher Q-Exactive) was used to identify two novel isomers of hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) which were unexpectedly observed in a commercial standard of TBPH. By combining ultra-high resolution (UHR) mass spectra (MS(1)), mass errors to theoretical [TBPH-Br+O](-) were 2.1 and 1.0 ppm for the two isomers, UHR-MS(2) spectra and NMR analysis; the structures of the two compounds were identified as hydroxylated TBPH with a hydroxyl group on the aromatic ring. Relatively great proportions of the two isomers of OH-TBPH were detected in two technical products, Firemaster 550 (FM-550; 0.1% and 6.2%, respectively) and Firemaster BZ 54 (BZ-54; 0.1% and 7.9%), compared to a commercial standard (0.4% and 0.9%). To simultaneously analyze OH-TBPH isomers and TBPH in samples of dust, a method based on LC-UHRMS was developed to quantify the two compounds, using negative and positive ion modes, respectively. The instrumental limit of detection for TBPH was 0.01 μg/L, which was 200-300 times better than traditional methods (2.5 μg/L) based on gas chromatography-mass spectrometry. The analytical method combined with a Florisil cleanup was successfully applied to analyze TBPH and OH-TBPH in 23 indoor dust samples from Saskatoon, Saskatchewan, Canada. Two OH-TBPH isomers, OH-TBPH1 and OH-TBPH2, were detected in 52% and 91% of dust samples, respectively. Concentrations of OH-TBPH2 (0.35 ± 1.0 ng/g) were 10-fold greater than those of OH-TBPH1 (0.04 ± 0.88 ng/g) in dust, which was similar to profiles in FM-550 and BZ-54. TBPH was also detected in 100% of dust samples with a mean concentration of 733 ± 0.87 ng/g. A significant (p < 0.001) log-linear relationship was observed between TBPH and OH-TBPH isomers, further supporting the hypothesis of a common source of emission. Relatively small proportions of OH-TBPH isomers were detected in dust (0.01% ± 0.67 OH-TBPH1 and 0.1% ± 0.60 OH-TBPH2

  19. Kinetics of palladium extraction with bis(2-ethylhexyl)monothiophosphoric acid in a hollow fiber membrane extractor

    SciTech Connect

    Alam, M.S.; Inoue, K.; Yoshizuka, K.

    1996-11-01

    A kinetic study on palladium extraction from chloride media with bis(2-ethylhexyl)monothiophosphoric acid in EXXSOL D-80 was carried out at 303 K using a hollow fiber membrane extractor, together with equilibrium studies on the interfacial adsorption and aqueous distribution of the extractant as well as the loading test of palladium. It was found that bis(2-ethylhexyl)-monothiophosphoric acid exists as a dimeric species in organic diluent, which is hardly soluble in the aqueous phase but adsorbs at the interface. Palladium is extracted as a 1:2 metal/reagent complex. The order of the extraction rate was found to be 1, 0, and 1 with respect to the concentrations of palladium ion, hydrogen ion, and dimeric extractant, respectively, while it was found to be 0 and {minus}1n (n < 1) with respect to chloride ion in its low and high concentration region, respectively. The apparent reaction rate constants of the extraction reaction were determined experimentally. The extraction rates were reasonably explained in terms of a combination of a diffusion model and an interfacial reaction model. Palladium is widely used in various fields of industry such as manufacturing industrial catalysts, petrochemicals, automobiles, electronic devices, corrosion-resistant and high-temperature withstanding materials, fuel cells, etc.

  20. ATSDR evaluation of health effects of chemicals. VI. Di(2-ethylhexyl)phthalate. Agency for Toxic Substances and Disease Registry.

    PubMed

    Fay, M; Donohue, J M; De Rosa, C

    1999-12-01

    Di(2-ethylhexyl)phthalate (also known as DEHP, bis(2-ethylhexyl)phthalate, or BEHP; CAS Registry Number 117-81-7) is a widely-used plasticizer. It is found in numerous plastic articles, such as paints, inks, floor tiles, upholstery, shower curtains, footwear, plastic bags, food-packaging materials, toys, and medical tubing. Not surprisingly, DEHP appears at many waste sites. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals that are of greatest public health concern at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priority List (NPL) sites. These profiles comprehensively summarize toxicological and environmental information. This article constitutes the release of the bulk of ATSDR's profile for DEHP (ATSDR, 1993) into the mainstream scientific literature. An extensive listing of human and animal health effects, organized by route, duration, and endpoint, is presented. Toxicological information on toxicokinetics, biomarkers, interactions, sensitive subpopulations, reducing toxicity after exposure, and relevance to public health is also included. Environmental information encompasses physical properties, production and use, environmental fate, levels seen in the environment, analytical methods, and a listing of regulations. ATSDR, at the behest of Congress and therefore the citizenry, prepares these profiles to inform the public about site contaminants.

  1. Experimental study on infusion devices containing polyvinyl chloride: to what extent are they di(2-ethylhexyl)phthalate-free?

    PubMed

    Genay, Stéphanie; Luciani, Chiara; Décaudin, Bertrand; Kambia, Nicolas; Dine, Thierry; Azaroual, Nathalie; Di Martino, Piera; Barthélémy, Christine; Odou, Pascal

    2011-06-30

    The use of medical devices containing highly criticized phthalates including di(2-ethylhexyl) phthalate (DEHP) has been challenged by European directive 2007/47/CE, put into effect in March 2010. New plasticizers are now being used to soften PVC in medical devices: trioctyltrimellitate (TOTM), di-isononyl-cyclohexan-1,2-dicarboxilate (DINCH) and di(2-ethylhexyl) terephthalate (DEHT). To quantify DEHP in nine DEHP-free medical devices made of PVC softened by alternative plasticizers, high performance liquid chromatography analysis with ultraviolet detection at 220 nm wavelength was achieved. An NMR spectroscopy was performed to confirm DEHP presence. Only two medical devices out of the nine tested were truly without DEHP. One of them showed traces of DEHP exceeding the threshold contamination of 0.1% in plastic mass set by REACH regulations. TOTM plasticizer is still incriminated when polyvinyl-chloride (PVC) is contaminated with DEHP. Manufacturers must verify the purity of their raw material, not only on PVC, but also on other soft plastics entering into the composition of medical infusion devices. The clinical consequences of exposure to certain levels of DEHP have not been evaluated. A solution could be to use alternative PVC-free materials.

  2. The thermodynamic properties of 2-ethylhexyl acrylate over the temperature range from T → 0 to 350 K

    NASA Astrophysics Data System (ADS)

    Kulagina, T. G.; Samosudova, Ya. S.; Letyanina, I. A.; Sevast'yanov, E. V.; Smirnova, N. N.; Smirnova, L. A.; Mochalova, A. E.

    2012-05-01

    The temperature dependence of the heat capacity C {/p o}= f( T) 2 of 2-ethylhexyl acrylate was studied in an adiabatic vacuum calorimeter over the temperature range 6-350 K. Measurement errors were mainly of 0.2%. Glass formation and vitreous state parameters were determined. An isothermic shell calorimeter with a static bomb was used to measure the energy of combustion of 2-ethylhexyl acrylate. The experimental data were used to calculate the standard thermodynamic functions C {/p o}( T), H o( T)- H o(0), S o( T)- S o(0), and G o( T)- H o(0) of the compound in the vitreous and liquid states over the temperature range from T → 0 to 350 K, the standard enthalpies of combustion Δc H o, and the thermodynamic characteristics of formation Δf H o, Δf S o, and Δf G o at 298.15 K and p = 0.1 MPa.

  3. Comparative microarray analyses of mono(2-ethylhexyl)phthalate impacts on fat cell bioenergetics and adipokine network.

    PubMed

    Chiang, Huai-Chih; Wang, Chih-Hong; Yeh, Szu-Ching; Lin, Yi-Hua; Kuo, Ya-Ting; Liao, Chih-Wei; Tsai, Feng-Yuan; Lin, Wei-Yu; Chuang, Wen-Han; Tsou, Tsui-Chun

    2017-01-12

    Cellular accumulation of mono(2-ethylhexyl)phthalate (MEHP) has been recently demonstrated to disturb fat cell energy metabolism; however, the underlying mechanism remained unclear. The study aimed to determine how MEHP influenced fat cell transcriptome and how the changes might contribute to bioenergetics. Because of the pivotal role of PPARγ in energy metabolism of fat cells, comparative microarray analysis of gene expression in 3T3-L1 adipocytes treated with both MEHP and rosiglitazone was performed. Pathway enrichment analysis and gene ontology (GO) enrichment analysis revealed that both treatments caused up-regulation of genes involved in PPAR signaling/energy metabolism-related pathways and down-regulation of genes related to adipokine/inflammation signals. MEHP/rosiglitazone-treated adipocytes exhibited increased levels of lipolysis, glucose uptake, and glycolysis; the gene expression profiles provided molecular basis for the functional changes. Moreover, MEHP was shown to induce nuclear translocation and activation of PPARγ. The similarity in gene expression and functional changes in response to MEHP and rosiglitazone suggested that MEHP influenced bioenergetics and adipokine network mainly via PPARγ. Importantly, adipokine levels in C57BL/6J mice with di(2-ethylhexyl)phthalate (DEHP) treatments provided in vivo evidence for microarray results. On the basis of correlation between gene expression and functional assays, possible involvements of genes in bioenergetics of MEHP-treated adipocytes were proposed.

  4. Electrochemical and photophysical behavior of 1-naphthol in benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate large unilamellar vesicles.

    PubMed

    Cobo Solis, Airam K; Mariano Correa, N; Molina, Patricia G

    2016-06-21

    In the present contribution, 1-naphthol is investigated in large unilamellar vesicles formed from a new catanionic surfactant, benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate, by electrochemical and spectroscopic techniques. The electrochemical results show that 1-naphthol experiences a partition process between the water phase and the large unilamellar vesicle bilayer phase, which is corroborated by absorption spectroscopic studies at pH = 6.40 and pH = 10.75. Interestingly, studies of 1-naphthol emission in benzyl-n-hexadecyldimethylammonium 1,4-bis(2-ethylhexyl)sulfosuccinate large unilamellar vesicles at pH = 10.75 and in sodium 1,4-bis(2-ethylhexyl)sulfosuccinate water solution show that when the 1,4-bis(2-ethylhexyl)sulfosuccinate moiety is part of the bilayer, the 1,4-bis(2-ethylhexyl)sulfosuccinate polar head interacts strongly with 1-naphthol, by favoring emission from the excited neutral species resulting in the appearance of a new band close to λ = 355 nm. It seems that the large unilamellar vesicle bilayer of the catanionic vesicle slows down the proton transfer process observed in water, where only emission from 1-naphtholate is detected.

  5. In utero exposure to di-(2-ethylhexyl) phthalate induces testicular effects in neonatal rats that are antagonized by genistein cotreatment.

    PubMed

    Jones, Steven; Boisvert, Annie; Francois, Sade; Zhang, Liandong; Culty, Martine

    2015-10-01

    Fetal exposure to endocrine disruptors (EDs) is believed to predispose males to reproductive abnormalities. Although males are exposed to combinations of chemicals, few studies have evaluated the effects of ED mixtures at environmentally relevant doses. Our previous work showed that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di-(2-ethylhexyl) phthalate (DEHP) induced unique alterations in adult testis. In this follow-up study, we examined Postnatal Day 3 (PND3) and PND6 male offspring exposed from Gestational Day 14 to parturition to corn oil, 10mg/kg GEN, DEHP, or their combination, to gain insight into the early molecular events driving long-term alterations. DEHP stimulated the mRNA and protein expression of the steroidogenic enzyme HSD3B, uniquely at PND3. DEHP also increased the mRNA expression of Nestin, a Leydig progenitor/Sertoli cell marker, and markers of Sertoli cell (Wt1), gonocyte (Plzf, Foxo1), and proliferation (Pcna) at PND3, while these genes were unchanged by the mixture. Redox (Nqo1, Sod2, Sod3, Trx, Gst, Cat) and xenobiotic transporter (Abcb1b, Abcg2) gene expression was also increased by DEHP at PND3, while attenuated when combined with GEN, suggesting the involvement of cellular stress in short-term DEHP effects and a protective effect of GEN. The direct effects of GEN and mono-(2-ethylhexyl) phthalate, the principal bioactive metabolite of DEHP, on testis were investigated in PND3 organ cultures, showing a stimulatory effect of 10 μM mono-(2-ethylhexyl) phthalate on basal testosterone production that was normalized by GEN. These effects contrasted with previous reports of androgen suppression and decreased gene expression in perinatal rat testis by high DEHP doses, implying that neonatal effects are not predictive of adult effects. We propose that GEN, through an antioxidant action, normalizes reactive oxygen species-induced neonatal effects of DEHP. The notion that these EDs do not follow classical

  6. Evaluation of cytotoxicity and oxidative DNA damaging effects of di(2-ethylhexyl)-phthalate (DEHP) and mono(2-ethylhexyl)-phthalate (MEHP) on MA-10 Leydig cells and protection by selenium

    SciTech Connect

    Erkekoglu, Pinar; Rachidi, Walid; Giray, Belma; Favier, Alain; Hincal, Filiz

    2010-10-01

    Di(2-ethylhexyl)-phthalate (DEHP) is the most abundantly used phthalate derivative, inevitable environmental exposure of which is suspected to contribute to the increasing incidence of testicular dysgenesis syndrome in humans. Oxidative stress and mitochondrial dysfunction in germ cells are suggested to contribute to phthalate-induced disruption of spermatogenesis in rodents, and Leydig cells are one of the main targets of phthalates' testicular toxicity. Selenium is known to be involved in the modulation of intracellular redox equilibrium, and plays a critical role in testis, sperm, and reproduction. This study was aimed to investigate the oxidative stress potential of DEHP and its consequences in testicular cells, and examine the possible protective effects of selenium using the MA-10 mouse Leydig tumor cell line as a model. In the presence and absence of selenium compounds [30 nM sodium selenite (SS), and 10 {mu}M selenomethionine (SM)], the effects of exposure to DEHP and its main metabolite mono(2-ethylhexyl)-phthalate (MEHP) on the cell viability, enzymatic and non-enzymatic antioxidant status, ROS production, p53 expression, and DNA damage by alkaline Comet assay were investigated. The overall results of this study demonstrated the cytotoxicity and genotoxicity potential of DEHP, where MEHP was found to be more potent than the parent compound. SS and SM produced almost the same level of protection against antioxidant status modifying effects, ROS and p53 inducing potentials, and DNA damaging effects of the two phthalate derivatives. It was thus shown that DEHP produced oxidative stress in MA-10 cells, and selenium supplementation appeared to be an effective redox regulator in the experimental conditions used in this study, emphasizing the critical importance of the appropriate selenium status.

  7. Characterizing interfacial friction in bis(2-ethylhexyl) sodium sulfosuccinate reverse micelles from photoisomerization studies of carbocyanine derivatives

    NASA Astrophysics Data System (ADS)

    Gangamallaiah, V.; Dutt, G. B.

    2011-01-01

    Photoisomerization of two carbocyanine derivatives has been examined in bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles to understand the factors that govern this process in the interfacial region of organized assemblies. To this effect, fluorescence lifetimes and quantum yields of 3,3'-diethyloxadicarbocyanine iodide and merocyanine 540 have been measured in AOT/isooctane/water and AOT/cyclohexane/water reverse micellar systems as a function of the mole ratio of water to the surfactant, W. The nonradiative rate constants, which have been identified as the rates of photoisomerization for these solutes, were obtained from the experimentally measured parameters. The steady rise and subsequent saturation observed in the nonradiative rate constants upon increasing W has been rationalized in terms of micellar packing. An inverse correlation has been obtained between the nonradiative rate constants and the critical packing parameter, indicating that the interfacial friction experienced by the solute molecule is essentially described by this parameter.

  8. Extraction equilibrium of indium(III) from nitric acid solutions by di(2-ethylhexyl)phosphoric acid dissolved in kerosene.

    PubMed

    Tsai, Hung-Sheng; Tsai, Teh-Hua

    2012-01-04

    The extraction equilibrium of indium(III) from a nitric acid solution using di(2-ethylhexyl) phosphoric acid (D2EHPA) as an acidic extractant of organophosphorus compounds dissolved in kerosene was studied. By graphical and numerical analysis, the compositions of indium-D2EHPA complexes in organic phase and stoichiometry of the extraction reaction were examined. Nitric acid solutions with various indium concentrations at 25 °C were used to obtain the equilibrium constant of InR₃ in the organic phase. The experimental results showed that the extraction distribution ratios of indium(III) between the organic phase and the aqueous solution increased when either the pH value of the aqueous solution and/or the concentration of the organic phase extractant increased. Finally, the recovery efficiency of indium(III) in nitric acid was measured.

  9. Health hazards associated with the use of di-(2-ethylhexyl) phthalate (commonly referred to as DOP) in HEPA filter test

    SciTech Connect

    1995-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), commonly referred to as di-octyl phthalate, is an important production chemical in the US. In addition to its major use as an additive in plastics, DEHP is widely used to evaluate the effectiveness of high efficiency particulate air (HEPA) filters. Historically, DEHP was also used in quantitative fit testing for respirators. Evaluations of this compound a decade ago showed that it can induce hepatocellular carcinomas in laboratory animals. Although most Department of Energy (DOE) facilities have since discontinued using DEHP in respirator fit testing, DEHP continues to be used for evaluating HEPA filters. This report summarizes available information on the toxicity, mutagenicity, carcinogenicity, and other hazards and problems posed by DEHP, specifically with reference to HEPA filter testing. Information on work practice improvements as well as the availability and suitability of DEHP substitutes are also presented. This material should assist the DOE in the safe use of this material.

  10. Copper mediated controlled radical copolymerization of styrene and 2-ethylhexyl acrylate and determination of their reactivity ratios.

    NASA Astrophysics Data System (ADS)

    Koiry, Bishnu; Singha, Nikhil

    2014-10-01

    Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA) and styrene using copper bromide (CuBr) as catalyst in combination with N,N,N’,N”,N”- pentamethyldiethylenetriamine (PMDETA) as ligand and 1-phenylethyl bromide (PEBr) as initiator. Linear kinetic plot and linear increase in molecular weights versus conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using 1H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2) were determined using the Finemann-Ross (FR), inverted Finemann-Ross (FR) and Kelen-Tudos (KT) methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

  11. Determination of Activity Coefficients of di-(2-ethylhexyl) Phosphoric Acid Dimer in Select Organic Solvents Using Vapor Phase Osmometry

    SciTech Connect

    Michael F. Gray; Peter Zalupski; Mikael Nilsson

    2013-08-01

    Effective models for solvent extraction require accurate characterization of the nonideality effects for each component, including the extractants. In this study, the nonideal behavior of the industrial extractant di(2-ethylhexyl) phosphoric acid has been investigated using vapor pressure osmometry (VPO). From the osmometry data, activity coefficients for the HDEHP dimer were obtained based on a formulation of the regular solution theory of Scatchard and Hildebrand, and the Margules two- and three-suffix equations. The results show similarity with a slope-analysis based relation from previous literature, although important differences are highlighted. The work points towards VPO as a useful technique for this type of study, but care must be taken with the choice of standard and method of analysis.

  12. Mono(2-Ethylhexyl) Phthalate Accelerates Early Folliculogenesis and Inhibits Steroidogenesis in Cultured Mouse Whole Ovaries and Antral Follicles1

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Flaws, Jodi A.

    2015-01-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant present in common consumer products. DEHP potentially targets the ovary through its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, the direct effects of MEHP on ovarian folliculogenesis and steroidogenesis, two processes essential for reproductive and nonreproductive health, are unknown. The present study tested the hypotheses that MEHP directly accelerates early folliculogenesis via overactivation of phosphatidylinositol 3-kinase (PI3K) signaling, a pathway that regulates primordial follicle quiescence and activation, and inhibits the synthesis of steroid hormones by decreasing steroidogenic enzyme levels. Neonatal ovaries from CD-1 mice were cultured for 6 days with vehicle control, DEHP, or MEHP (0.2–20 μg/ml) to assess the direct effects on folliculogenesis and PI3K signaling. Further, antral follicles from adult CD-1 mice were cultured with vehicle control or MEHP (0.1–10 μg/ml) for 24–96 h to establish the temporal effects of MEHP on steroid hormones and steroidogenic enzymes. In the neonatal ovaries, MEHP, but not DEHP, decreased phosphatase and tensin homolog levels and increased phosphorylated protein kinase B levels, leading to a decrease in the percentage of germ cells and an increase in the percentage of primary follicles. In the antral follicles, MEHP decreased the mRNA levels of 17alpha-hydroxylase-17,20-desmolase, 17beta-hydroxysteroid dehydrogenase, and aromatase leading to a decrease in testosterone, estrone, and estradiol levels. Collectively, MEHP mediates the effect of DEHP on accelerated folliculogenesis via overactivating PI3K signaling and inhibits steroidogenesis by decreasing steroidogenic enzyme levels. PMID:25810477

  13. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite.

    PubMed

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2016-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.

  14. Relationship between urinary concentrations of di(2-ethylhexyl) phthalate (DEHP) metabolites and reproductive hormones in polyvinyl chloride production workers.

    PubMed

    Fong, Jer-Pei; Lee, Fang-Jin; Lu, I-Syuan; Uang, Shi-Nian; Lee, Ching-Chang

    2015-05-01

    We investigated the relationship between urinary metabolites of di(2-ethylhexyl) phthalate (DEHP) and reproductive hormones in workers of polyvinyl chloride (PVC) production plants. After exposure, most of the DEHP is rapidly metabolised to mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), which may be associated with reproductive hormone interruption and testicular toxicity. Some studies report that urinary concentrations of phthalate metabolites for plastics workers are significantly higher than for the general population. However, little is known about the disruption of reproductive hormones for DEHP exposure workers. This cross-sectional study of 82 male workers measured the biomarkers for their reproductive hormones and their exposure to DEHP. Relationships between urinary concentrations of DEHP metabolites were estimated using multivariate linear regression and quartile analysis models. The geometric means of urinary creatinine-adjusted (μg/g-Cre) concentrations of MEHP, MEOHP and MEHHP during the post-shift period were 23.9, 66.9 and 84.6, respectively. In multiple regression models adjusted for potential confounders, there were significant positive associations between urinary concentrations of DEHP metabolites and estradiol (E2) (p<0.01), and in the ratio of E2 to testosterone (p<0.05). Moreover, quartile analysis showed significant positive relationships between the total urinary concentration of DEHP metabolites and E2 (ptrend=0.024), and in the ratio of E2 to testosterone (ptrend=0.031). Relationships between reproductive hormones and the total urinary concentration of DEHP metabolites in male PVC production workers were significantly positive. This indicated that aromatase activity had increased in male workers exposed to DEHP, which is consistent with animal studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a

  15. Urinary concentrations of di(2-ethylhexyl) phthalate metabolites and serum reproductive hormones: Pooled analysis of fertile and infertile men

    PubMed Central

    Mendiola, Jaime; Meeker, John D.; Jørgensen, Niels; Andersson, Anna-Maria; Liu, Fan; Calafat, Antonia M.; Redmon, J. Bruce; Drobnis, Erma Z.; Sparks, Amy E.; Wang, Christina; Hauser, Russ; Swan, Shanna H.

    2012-01-01

    Urinary concentrations of metabolites of the anti-androgenic xenobiotic di-(2-ethylhexyl) phthalate (DEHP) were previously shown to be weakly associated with serum levels of several hormones in two disparate US populations; partners of pregnant women participating in the Study for Future Families, and partners in an infertile couple from Massachusetts General Hospital infertility clinic. The observed associations between phthalate metabolites and reproductive hormones were robust and insensitive to the characteristics of the subpopulation or the laboratory in which the hormones were measured, despite the fact that these two populations span a range of fertility, urinary phthalate metabolites and reproductive hormone levels. We therefore examined associations between urinary metabolites of DEHP and reproductive hormones (follicle stimulating hormone, luteinizing hormone, testosterone (T), inhibin B and estradiol (E2), and sex hormone-binding globulin (SHGB) in the pooled population. The magnitude of the associations seen were similar to those reported for each population separately, but effect estimates were more precise due to the increased sample size, and the greater range of phthalate metabolite concentrations and hormone levels. Urinary concentrations of three metabolites of DEHP [mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP)] were inversely associated with the free androgen index (FAI = T/SHBG) and calculated free testosterone (FT). Urinary concentrations of MEHHP and MEOHP were positively associated with SHBG, and MEHP was inversely associated with E2. No other phthalate metabolites were associated with serum hormones, consistent with results in each population. Our results in this diverse population suggest that DEHP exposure is robustly associated with some male sex steroid hormones. PMID:21597090

  16. Mono-(2-ethylhexyl) phthalate (MEHP) regulates glucocorticoid metabolism through 11{beta}-hydroxysteroid dehydrogenase 2 in murine gonadotrope cells

    SciTech Connect

    Hong, Dun; Li, Xing-Wang; Lian, Qing-Quan; Lamba, Pankaj; Bernard, Daniel J.; Hardy, Dianne O.; Chen, Hai-Xiao; Ge, Ren-Shan

    2009-11-13

    Di-(2-ethylhexyl) phthalate (DEHP) and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) have been classified as toxicants to the reproductive system at the testis level and DEHP may also impair reproductive axis function at the pituitary levels. However, MEHP is 10-fold more potent than DEHP in toxicity and little is known about the toxicological effect of MEHP on pituitary. In this study, we demonstrated that 11{beta}-hydroxysteroid dehydrogenase type 2 (11{beta}-HSD2), not 11{beta}-HSD1, is strongly expressed in murine gonadotrope L{beta}T2 cells. Interestingly, MEHP inhibited Hsd11b2 mRNA level and 11{beta}-HSD2 enzyme activity in L{beta}T2 cells at as low as 10{sup -7} M. Corticosterone (CORT) at a concentration of 10{sup -6} M significantly inhibited L{beta}T2 cell proliferation after 2-day culture, and 10{sup -6} M RU486, an antagonist of glucocorticoid receptor (GR), reversed this inhibition. However, in the presence of 10{sup -5} or 10{sup -4} M MEHP, the minimal concentration of CORT to inhibit the proliferation of L{beta}T2 cells was lowered to 10{sup -7} M, and 10{sup -6} M RU486 was not able to completely reverse the CORT effect. In conclusion, along with the regulation of GR, 11{beta}-HSD2 may have a key role in glucocorticoid metabolism in L{beta}T2 cells. MEHP may participate in the glucocorticoid metabolism in L{beta}T2 cells through inhibition of 11{beta}-HSD2 enzyme activity. Such perturbation may be of pathological significance as MEHP may interfere with the reproductive system at pituitary level through regulation of glucocorticoid metabolism, especially in neonates with higher risk of phthalates exposure.

  17. Use of Mass Spectrometry for Identification of Biomarkers of Exposure to the Flame Retardant DI(2-Ethylhexyl)-2,3,4,5-Tetrabromophthlate

    EPA Science Inventory

    Di-(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one component in the technical formulation of Firemaster 550, a fire retardant used after phasing out certain polybrominated diphenyl ethers. Firemaster 550 is used widely and its use may result in human exposure to TBPH. To...

  18. HEPATOCYTE EXPRESION OF TUMOR ASSOCIATED ALDEHYDE DEHYDROGENASE (ALDH-3) AND P21 RAS FOLLOWING DIETHYLNITROSAMINE (DEN) INITIATION AND CHRONIC EXPOSURE TO DI(2-ETHYLHEXYL) PHTHALATE (DHEP)

    EPA Science Inventory

    Phthalate esters such as di(2-ethylhexyl)phthalate (DEHP)either promote or inhibit rat liver tumorigenesis depending on the carcinogenesis protocol. In this study, we examined the expression of two histochemical markers, the tumor associated isozyme of aldehyde dehydrogenase (ALD...

  19. Use of Mass Spectrometry for Identification of Biomarkers of Exposure to the Flame Retardant DI(2-Ethylhexyl)-2,3,4,5-Tetrabromophthlate

    EPA Science Inventory

    Di-(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one component in the technical formulation of Firemaster 550, a fire retardant used after phasing out certain polybrominated diphenyl ethers. Firemaster 550 is used widely and its use may result in human exposure to TBPH. To...

  20. Data from one test "Semi-Volatile Organic Compound Small Chamber for bis (2-Ethylhexyl) phthalate in Vinyl Flooring Test 2"

    EPA Science Inventory

    This data was generated from a small chamber bis(2-ethylhexyl) phthalate (DEHP) emission test. It was to participate an interaboratory study of DEHP emissions from vinyl flooring in a SVOC emission chamber organized by Virginia Polytechnic Institute and State University (VT).

  1. Data from one test "Semi-Volatile Organic Compound Small Chamber for bis (2-Ethylhexyl) phthalate in Vinyl Flooring Test 2"

    EPA Science Inventory

    This data was generated from a small chamber bis(2-ethylhexyl) phthalate (DEHP) emission test. It was to participate an interaboratory study of DEHP emissions from vinyl flooring in a SVOC emission chamber organized by Virginia Polytechnic Institute and State University (VT).

  2. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    SciTech Connect

    Kessler, Winfried; Numtip, Wanwiwa; Völkel, Wolfgang; Seckin, Elcim; Csanády, György A.; Pütz, Christian; and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  3. A review of alternatives to di (2-ethylhexyl) phthalate-containing medical devices in the neonatal intensive care unit

    PubMed Central

    Van Vliet, EDS; Reitano, EM; Chhabra, JS; Bergen, GP; Whyatt, RM

    2012-01-01

    Objective To conduct an extensive literature and toxicological database review on substitute compounds and available alternative medical products to replace polyvinyl chloride (PVC) and/or di(2-ethylhexyl) phthalate (DEHP), and conduct a DEHP-medical inventory analysis at a large metropolitan neonatal intensive care unit (NICU). Study Design A systematic search for DEHP-free alternative products was performed using online databases. An informal audit of a large metropolitan NICU was undertaken in 2005 and 2006; 21 products were identified that could potentially contain DEHP. Availability of DEHP-free alternatives was determined through company websites and phone interviews. Result Two alternative approaches are available for replacing DEHP in NICU medical products: (1) replacement by DEHP-free plasticizers; and (2) replacement of PVC entirely through the use of other polymers. Both approaches seem to provide less harmful substitutes to DEHP, but support PVC-free polymers as the preferred alternative. However, significant data gaps exist, particularly for the alternative polymers. In all, 10 out of 21 (48%) products in the NICU audit were DEHP-free; six consisted of alternative polymers and four of alternative plasticizers. Of the remaining 11 products, only three were available without DEHP at the time of the audit. Conclusion Because of significant data gaps, systematic toxicological testing of DEHP-free alternatives is imperative. Continued development of alternative products is also needed. PMID:21311501

  4. Low-dose exposure to di-(2-ethylhexyl) phthalate (DEHP) increases susceptibility to testicular autoimmunity in mice.

    PubMed

    Hirai, Shuichi; Naito, Munekazu; Kuramasu, Miyuki; Ogawa, Yuki; Terayama, Hayato; Qu, Ning; Hatayama, Naoyuki; Hayashi, Shogo; Itoh, Masahiro

    2015-09-01

    Exposure to di-(2-ethylhexyl) phthalate (DEHP) induces spermatogenic disturbance (SD) through oxidative stress, and affects the immune system by acting as an adjuvant. Recently, we reported that in mice, a low dose of DEHP, which did not affect spermatogenesis, was able to alter the testicular immune microenvironment. Experimental autoimmune orchitis (EAO) can be induced by repeated immunization with testicular antigens, and its pathology is characterized by production of autoantibodies and SD. In the present study, we investigated the effect of a low-dose DEHP on the susceptibility of mice to EAO. The exposure to DEHP-containing feed (0.01%) caused a modest functional damage to the blood-testis barrier (BTB) with an increase in testicular number of interferon gamma (IFN-γ)-positive cells and resulted in the production of autoantibodies targeting haploid cells, but did not affect spermatogenesis. While only single immunization with testicular antigens caused very mild EAO, the concurrent DEHP exposure induced severe EAO with significant increases in number of interferon gamma-positive cells and macrophages, as well as lymphocytic infiltration and serum autoantibody titer accompanied by severe SD. To summarize, the exposure of mice to the low-dose DEHP does not induce significant SD, but it may cause an increase in IFN-γ positive cells and modest functional damage to the BTB in the testis. These changes lead to an autoimmune response against haploid cell autoantigens, resulting in increased susceptibility to EAO.

  5. Effects of Di-(2-ethylhexyl) Phthalate on Lipid Metabolism by the JAK/STAT Pathway in Rats

    PubMed Central

    Jia, Yiyang; Liu, Te; Zhou, Liting; Zhu, Jian; Wu, Juan; Sun, Di; Xu, Jin; Wang, Qi; Chen, Huaiji; Xu, Feng; Zhang, Yuezhu; Zhang, Tianrong; Liu, Hongbo; Ye, Lin

    2016-01-01

    The most widely used plasticizer, di-(2-ethylhexyl) phthalate (DEHP), is known to affect lipid metabolism and adipogenesis. We studied the effects of dietary DEHP exposure on metabolism in rats as well as the role of the JAK/STAT pathway in this process. Eighty rats were exposed to DEHP (0, 5, 50 and 500 mg/kg/d) through dietary intake for 4 weeks. We then collected blood samples, liver, and adipose tissues to detect modifications in the levels of serum lipids, leptin, adiponectin and insulin. JAK3, STAT5a and PPARγ expression were detected at both the gene and protein levels. The activation of JAK3 and STAT5a was also detected. The DEHP-exposed rats had increased body weight, serum lipid, insulin, and leptin levels. Moreover, the JAK3/STAT5a pathway was activated in the adipose tissue; however, this pathway was not activated in the liver. The mRNA of SREBP-1c in the liver was increased significantly among each of the groups, in contrast to the levels found in the mature SREBP-1c protein form. Furthermore, the expression of FABP4, Acox and FASn was decreased in the liver, but increased in adipose tissue. Thus, we conclude that exposure to DEHP reduces the hydrolysis of lipid and promotes triglyceride accumulation by oppositely regulating the activation state of JAK/STAT pathway in the liver and adipose tissue, resulting in the disorder of body lipid metabolism and obesity. PMID:27827939

  6. Effect of di(2-ethylhexyl) phthalate (DEHP) on lipolysis and lipoprotein lipase activities in adipose tissue of rats.

    PubMed

    Martinelli, Marcela I; Mocchiutti, Norberto O; Bernal, Claudio A

    2010-09-01

    The di(2-ethylhexyl) phthalate (DEHP) is an ubiquitous environmental chemical with detrimental health effects. The present work was designed to asses some potential mechanisms by which DEHP causes, among others, a reduced body fat retention. Since this effect could be related to an alteration of adipocyte triacylglycerol (TG) metabolism, we evaluated the effects of dietary DEHP in adipose tissues upon (1) the number and size of fat cells; (2) the basal and stimulated lipolysis and (3) the lipoprotein lipase (LPL) activity. Groups of male Wistar rats were fed for 21 days a control diet alone (control group) or the same control diet supplemented with 2% (w/w) of DEHP (DEHP group). The LPL activity of DEHP-fed rats was increased in lumbar and epididymal adipose tissues. These rats had significantly reduced weight in epididymal and lumbar tissues, together with reduced size of epididymal adipocytes. These alterations do not seem to be associated with higher lipid mobility because neither basal lipolysis nor 'in vitro' stimulated lipolysis by noradrenaline (NA) showed to be modified by DEHP. Based on these results, we concluded that the adipose tissue size reduction induced by DEHP intake is not due to changes in lipolysis nor to a decreased LPL activity. More research is needed to achieve a comprehensive understanding of the potential mechanisms by which DEHP causes, among others, a reduced body fat retention.

  7. Transcriptional deregulation of genetic biomarkers in Chironomus riparius larvae exposed to ecologically relevant concentrations of di(2-ethylhexyl) phthalate (DEHP)

    PubMed Central

    Morcillo, Gloria; Planelló, Rosario

    2017-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental pollutant used worldwide as a plasticizer and solvent in many formulations. Based on available toxicological data, it has been classified as toxic for reproduction and as an endocrine disruptor. Despite this, ecotoxicological studies in aquatic wildlife organisms are still scarce. In the present work, the toxic molecular alterations caused by DEHP in aquatic larvae of the midge Chironomus riparius have been studied, by analyzing the transcriptional activity of genes related to some vital cellular pathways, such as the ribosomal machinery (rpL4, rpL13), the cell stress response (hsc70, hsp70, hsp40, hsp27), the ecdysone hormone pathway (EcR), the energy metabolism (GAPDH), and detoxication processes (CYP4G). Environmentally relevant concentrations (10−3 to 105 μg/L) and exposure conditions (24 to 96 h) have been tested, as well as the toxic effects after DEHP withdrawal. Although the compound caused no mortality, significant changes were detected in almost all the studied biomarkers: e.g. strong repression of hsp70; general inhibition of EcR; GAPDH activity loss in long exposures; among others. Our data show a general transcriptional downregulation that could be associated with an adaptive response to cell damage. Besides, the activity of the compound as an ecdysone antagonist and its delayed effects over almost all the biomarkers analyzed are described as novel toxic targets in insects. PMID:28166271

  8. Fourier transform infrared study on microemulsion system of potassium salt of bis(2-ethylhexyl) phosphinic acid (HA)

    NASA Astrophysics Data System (ADS)

    Zhou, Weijin; Shi, Nai; Wang, Yi; Chang, Zhiyuan; Wu, JinGuang

    1994-01-01

    To study microemulsion formation in a solvent extraction system is to probe into some basic principles of extraction chemistry in the light of combining extraction chemistry with surface chemistry. In our previous investigations, the microemulsions of the salts of HDEHP and PC88A have been studied systematically by FT-IR. In the experiment, we observed the change of peak positions and intensities of P equals O, P-O-C and P-O-H groups during saponification and hydration, and discovered that the peak of P-O-C splits apart into 1045 and 1075 cm-1. The vibration frequency of the P-O-C group in HDEHP and PC88A is quite close to the symmetric stretching frequency of the POO- group, and thus causes difficulties in the study of their peak position and absorbance variation. For this reason we synthesized bis(2-ethylhexyl) phosphinic acid without the P-O-C group. Infrared spectra in the range of 800 - 4000 cm-1 of this microemulsion system was studied.

  9. Di2-ethylhexyl phthalate disrupts thyroid hormone homeostasis through activating the Ras/Akt/TRHr pathway and inducing hepatic enzymes

    PubMed Central

    Ye, Hanfeng; Ha, Mei; Yang, Min; Yue, Ping; Xie, Zhengyuan; Liu, Changjiang

    2017-01-01

    Di(2-ethylhexyl) phthalate (DEHP), as a widespread environmental pollutant and an endocrine disruptor, can disturb the homeostasis of thyroid hormones (THs). In order to elucidate roles of the MAPK and PI3K/Akt pathways and hepatic enzymes in thyroid-disrupting effects of DEHP, Sprague-Dawley rats were dosed with DEHP by gavage for 30 consecutive days; Nthy-ori 3-1 cells were treated with DEHP with NAC, k-Ras siRNA or inhibitors (U0126 and wortmannin). Results showed that DEHP led to histopathologic changes in rat thyroid and liver, such as the decrease in thyroid follicular cavity diameter, hepatocyte edema. Triiodothyronine (T3), thyroxine (T4) and thyrotropin releasing hormone (TRH) were reduced. DEHP caused ROS production, oxidative stress and k-Ras upregulation, thereby activating the ERK and Akt pathways in vivo and in vitro. Moreover, TRH receptor (TRHr) level was elevated after the activation of the Akt pathway and was downregulated after the inhibition of the Akt pathway. However, TRHr was not modulated by the ERK pathway. Additionally, hepatic enzymes, including Ugt1a1, CYP2b1, Sult1e1, and Sult2b1, were significantly induced after DEHP exposure. Taken together, DEHP can perturb TH homeostasis and reduce TH levels. The activated Ras/Akt/TRHr pathway and induced hepatic enzymes play vital roles in thyroid-disrupting effects of DEHP. PMID:28065941

  10. Di2-ethylhexyl phthalate disrupts thyroid hormone homeostasis through activating the Ras/Akt/TRHr pathway and inducing hepatic enzymes.

    PubMed

    Ye, Hanfeng; Ha, Mei; Yang, Min; Yue, Ping; Xie, Zhengyuan; Liu, Changjiang

    2017-01-09

    Di(2-ethylhexyl) phthalate (DEHP), as a widespread environmental pollutant and an endocrine disruptor, can disturb the homeostasis of thyroid hormones (THs). In order to elucidate roles of the MAPK and PI3K/Akt pathways and hepatic enzymes in thyroid-disrupting effects of DEHP, Sprague-Dawley rats were dosed with DEHP by gavage for 30 consecutive days; Nthy-ori 3-1 cells were treated with DEHP with NAC, k-Ras siRNA or inhibitors (U0126 and wortmannin). Results showed that DEHP led to histopathologic changes in rat thyroid and liver, such as the decrease in thyroid follicular cavity diameter, hepatocyte edema. Triiodothyronine (T3), thyroxine (T4) and thyrotropin releasing hormone (TRH) were reduced. DEHP caused ROS production, oxidative stress and k-Ras upregulation, thereby activating the ERK and Akt pathways in vivo and in vitro. Moreover, TRH receptor (TRHr) level was elevated after the activation of the Akt pathway and was downregulated after the inhibition of the Akt pathway. However, TRHr was not modulated by the ERK pathway. Additionally, hepatic enzymes, including Ugt1a1, CYP2b1, Sult1e1, and Sult2b1, were significantly induced after DEHP exposure. Taken together, DEHP can perturb TH homeostasis and reduce TH levels. The activated Ras/Akt/TRHr pathway and induced hepatic enzymes play vital roles in thyroid-disrupting effects of DEHP.

  11. Effects of di(2-ethylhexyl)phthalate exposure on 1,2-dimethyhydrazine-induced colon tumor promotion in rats.

    PubMed

    Chen, Hsin-Pao; Pan, Min-Hsiung; Chou, Yuan-Yi; Sung, Chieh; Lee, Kuo-Hsin; Leung, Chung-Man; Hsu, Ping-Chi

    2017-05-01

    Di(2-ethylhexyl)phthalate (DEHP) may cause carcinogenicity in the liver; however, few have detailed on the potential effects of DEHP exposure on colorectal cancer. Male Sprague-Dawley rats received i.p. injections of 1,2-dimethylhydrazine (DMH) once-a-week for the first 4 weeks, and rats in each group were treated with DEHP through oral gavage daily for either 7, 10 or 15 weeks; after which, all rats were euthanized and their colons were assessed (a) morphologically for aberrant crypt foci (ACF) or tumors, (b) cytologically for mitotic index (MI), and (c) immunohistochemically for the expression of β-catenin, cyclooygenase (COX)-2, vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), cyclin D1, and c-myc. Our results indicated that the mean total ACF, tumor incidence, and MI were significantly higher in the DEHP-treated DMH compared to control and the DEHP-alone groups. The level of β-catenin and cyclin D1 was increased in DEHP-exposed rats. Expression of β-catenin, COX-2, VEGF, and cyclin D1 was significantly higher in the combined DMH and DEHP-treated rats by comparison to that of the DMH group. In conclusion, this study indicates that exposure to DEHP may exacerbate DMH-induced colon tumorigenesis and provides impetus to evaluate the effect of DEHP in conjunction with other carcinogens.

  12. Transcriptional deregulation of genetic biomarkers in Chironomus riparius larvae exposed to ecologically relevant concentrations of di(2-ethylhexyl) phthalate (DEHP).

    PubMed

    Herrero, Óscar; Morcillo, Gloria; Planelló, Rosario

    2017-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental pollutant used worldwide as a plasticizer and solvent in many formulations. Based on available toxicological data, it has been classified as toxic for reproduction and as an endocrine disruptor. Despite this, ecotoxicological studies in aquatic wildlife organisms are still scarce. In the present work, the toxic molecular alterations caused by DEHP in aquatic larvae of the midge Chironomus riparius have been studied, by analyzing the transcriptional activity of genes related to some vital cellular pathways, such as the ribosomal machinery (rpL4, rpL13), the cell stress response (hsc70, hsp70, hsp40, hsp27), the ecdysone hormone pathway (EcR), the energy metabolism (GAPDH), and detoxication processes (CYP4G). Environmentally relevant concentrations (10-3 to 105 μg/L) and exposure conditions (24 to 96 h) have been tested, as well as the toxic effects after DEHP withdrawal. Although the compound caused no mortality, significant changes were detected in almost all the studied biomarkers: e.g. strong repression of hsp70; general inhibition of EcR; GAPDH activity loss in long exposures; among others. Our data show a general transcriptional downregulation that could be associated with an adaptive response to cell damage. Besides, the activity of the compound as an ecdysone antagonist and its delayed effects over almost all the biomarkers analyzed are described as novel toxic targets in insects.

  13. Heat shock protein synthesis is induced by diethyl phthalate but not by di(2-ethylhexyl) phthalate in radish (Raphanus sativus).

    PubMed

    Saarma, Kaari; Tarkka, Mika T; Itävaara, Merja; Fagerstedt, Kurt V

    2003-09-01

    The toxicity and effects on protein synthesis of the phthalate esters diethyl phthalate (DEP) and di(2-ethylhexyl) phthalate (DEHP) was studied in radish seedings (Raphanus sativus cv. Kööpenhaminan tori). Phthalate esters are a class of commercially important compounds used mainly as plasticizers in high molecular-weight polymers such as many plastics. They can enter soil through various routes and can affect plant growth and development. First the effect of DEP and DEHP on the growth of radish seedings was determined in an aqueous medium. It was found that DEP, but not DEHP, caused retardation of growth in radish. A further investigation on protein synthesis during DEP-stress was executed by in vivo protein labeling combined with two-dimensional gel electrophoresis (2D-PAGE). For comparisons with known stress-induced proteins a similar experiment was done with heat shock, and the induced heat shock proteins (HSPs) were compared with those of DEP-stress. The results showed that certain HSPs can be used as an indicator of DEP-stress, although the synthesis of most HSPs was not affected by DEP. DEP also elicited the synthesis of numerous proteins found only in DEP-treated roots. The toxic effect of phthalate esters and the roles of the induced proteins are discussed.

  14. Quantitation of the nitrosamine 2-ethylhexyl-4-(N-methyl-N-nitrosoamino) benzoate (NPABAO) in sunscreen products.

    PubMed

    Meyer, T A; Powell, J B

    1991-01-01

    We have devised a method to quantitate the nitrosamine, 2-ethylhexyl-4-(N-methyl-N-nitrosoamino) benzoate (NPABAO), in commercial products containing the sunscreen ingredient, Padimate O. The method involves a minimum of cleanup steps to afford a nonaqueous extract from product emulsions suitable for analysis by a liquid chromatograph interfaced to a thermal energy analyzer (LC/TEA). The method is applicable to lotions, creams, and gels. Oils are normally soluble in the mobile phase and can be analyzed directly on the LC/TEA without additional cleanup procedures. The method has a minimum detectable limit of about 30 ppb and yields greater than 80% recovery. It is highly reproducible and generates no NPABAO artifactually prior to quantitation on the LC/TEA. Application of the method to 22 different commercial product formulas disclosed that the level of NPABAO in each of the products is below 250 ppb, with 18 of the products containing less than 100 ppb. Of interest was the observation that musk ketone, a common fragrance constituent, produces a false-positive TEA response that can interfere with accurate analysis of NPABAO content in typical commercial products.

  15. Degradation of phthalate and di-(2-ethylhexyl)phthalate by indigenous and inoculated microorganisms in sludge-amended soil

    SciTech Connect

    Roslev, P.; Madsen, P.L.; Thyme, J.B.; Henriksen, K.

    1998-12-01

    The metabolism of phthalic acid (PA) and di-(2-ethylhexyl) (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [{sup 14}C]PA and [{sup 14}C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [{sup 14}C]DEHP to {sup 14}CO{sub 2} increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of {sup 14}C-labelled phospholipid ester-linked fatty acids ({sup 14}C-PLFAs).

  16. CO2 foam properties and the stabilizing mechanism of sodium bis(2-ethylhexyl)sulfosuccinate and hydrophobic nanoparticle mixtures.

    PubMed

    Zhang, Chao; Li, Zhaomin; Sun, Qian; Wang, Peng; Wang, Shuhua; Liu, Wei

    2016-01-21

    In this work, we have prepared CO2-in-water foam by mixing partially hydrophobic SiO2 nanoparticles and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and studied its properties. The observation of the appearance of the foam revealed that, with the continuous addition of AOT, the phase behavior of the SiO2 nanoparticle and the AOT mixed system transformed from that of a two-phase system of aggregated nanoparticles into that of a uniform dispersed phase. Both foaming ability and foam stability were optimized when the nanoparticles and the AOT were mixed in a proportion of 1 : 5. On the basis of our findings from measurements of the dispersion properties, including measurements of the adsorption isotherm of the surfactant on the nanoparticles, zeta potentials, interfacial tension and the three-phase contact angle, we concluded that the synergistic interactions between the SiO2 nanoparticles and the AOT led to the adsorption of nanoparticles around the bubble surface and the formation of a spatial network structure of nanoparticles in the film, thereby enhancing the mechanical strength of the bubble and improving the resistance to outside disturbances, deformation and drainage. Laser scanning confocal microscopy (LCSM) analysis of the same foams further confirmed the existence of a "viscoelastic shell" wrapped around and protecting the bubble.

  17. Percolation phenomenon of calcium bis(2-ethylhexyl) sulfosuccinate water-in-oil microemulsions by conductivity and dielectric spectroscopy measurements.

    PubMed

    Capuzzi, G; Baglioni, P; Gambi, C M; Sheu, E Y

    1999-07-01

    The sodium counterion (Na+) of the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactant was exchanged with calcium Ca2+ to investigate the counterion charge effect on the structure of water in normal decane microemulsions. Ohmic conductivity and dielectric permittivity measurements were performed on samples at constant water to surfactant mole ratio [water]/[Ca(AOT)(2)]=26.6. Increasing the volume fraction of the dispersed phase phi, a percolation phenomenon was observed at the constant temperature of 25 degrees C. The percolation threshold was found at phi approximately 15% by Ohmic conductivity and static dielectric permittivity studied as a function of phi, and by the frequency dependence of the complex permittivity. Critical exponents typical of the static percolation mechanism (formation of bicontinuous microemulsions) were found below and above threshold. The comparison of these results obtained for the two different counterions, Ca2+ and Na+, in AOT surfactant water in normal decane microemulsions allows detection of an important difference. The percolation below threshold is dynamic for the sodium-based microemulsions, accounting for the formation of clusters of droplets, whereas calcium-based microemulsions show a static percolation. For this system, the coalescence of droplets begins to occur below threshold at phi approximately 12%.

  18. Effects of Di-(2-ethylhexyl) Phthalate on Lipid Metabolism by the JAK/STAT Pathway in Rats.

    PubMed

    Jia, Yiyang; Liu, Te; Zhou, Liting; Zhu, Jian; Wu, Juan; Sun, Di; Xu, Jin; Wang, Qi; Chen, Huaiji; Xu, Feng; Zhang, Yuezhu; Zhang, Tianrong; Liu, Hongbo; Ye, Lin

    2016-11-04

    The most widely used plasticizer, di-(2-ethylhexyl) phthalate (DEHP), is known to affect lipid metabolism and adipogenesis. We studied the effects of dietary DEHP exposure on metabolism in rats as well as the role of the JAK/STAT pathway in this process. Eighty rats were exposed to DEHP (0, 5, 50 and 500 mg/kg/d) through dietary intake for 4 weeks. We then collected blood samples, liver, and adipose tissues to detect modifications in the levels of serum lipids, leptin, adiponectin and insulin. JAK3, STAT5a and PPARγ expression were detected at both the gene and protein levels. The activation of JAK3 and STAT5a was also detected. The DEHP-exposed rats had increased body weight, serum lipid, insulin, and leptin levels. Moreover, the JAK3/STAT5a pathway was activated in the adipose tissue; however, this pathway was not activated in the liver. The mRNA of SREBP-1c in the liver was increased significantly among each of the groups, in contrast to the levels found in the mature SREBP-1c protein form. Furthermore, the expression of FABP4, Acox and FASn was decreased in the liver, but increased in adipose tissue. Thus, we conclude that exposure to DEHP reduces the hydrolysis of lipid and promotes triglyceride accumulation by oppositely regulating the activation state of JAK/STAT pathway in the liver and adipose tissue, resulting in the disorder of body lipid metabolism and obesity.

  19. Growth and antioxidant defense responses of wheat seedlings to di-n-butyl phthalate and di (2-ethylhexyl) phthalate stress.

    PubMed

    Gao, Minling; Dong, Youming; Zhang, Ze; Song, Wenhua; Qi, Yun

    2017-04-01

    Phthalate acid esters (PAEs) are vital environmental hormone-like chemicals that are noxious to plants, animals, and human beings. In this study, the influences of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on the seed germination, root morphology, and various physiological changes of wheat seedlings were investigated by analyzing superoxide anion (O2(-)) accumulation, antioxidant enzyme activity, and lipid peroxidation. DBP and DEHP were found to obviously inhibit germination only at high concentrations, but significantly affected root morphology even at lower concentrations. Their toxic effects were the most severe on root elongation, followed by shoot elongation, and were the least severe on germination rate, indicating that root elongation was the best index for evaluating DBP and DEHP eco-toxicity. DBP and DEHP also enhanced O2(-) and malondialdehyde levels and membrane permeability, as well as produced changes in the antioxidant status and PAE content in the stem and leaf (combined tissues, hereafter shoot) and root tissues. The activities of superoxide dismutase, catalase, and peroxidase increased at low and medium DBP and DEHP concentrations, but declined at high PAE concentrations. These results indicated that PAEs could exert oxidative damage in the early development stage of wheat, particularly at higher concentrations. DBP and DEHP accumulation was higher in the roots than in the shoot tissues, and their levels in these tissues increased with increasing PAE concentrations, supporting their more-serious toxic effects on roots than those on shoots. Further, the physicochemical properties of DBP rendered it more harmful than DEHP.

  20. Protective effects of vitamin E against reproductive toxicity induced by di(2-ethylhexyl) phthalate via PPAR-dependent mechanisms.

    PubMed

    Wang, Yangcai; Chen, Bailin; Lin, Tao; Wu, Shengde; Wei, Guanghui

    2017-09-01

    To investigate the protective/ameliorative effects of vitamin E on di-2-(ethylhexyl) phthalate (DEHP)-induced reproductive toxicity, particularly in testicular toxicity in male rats, emphasizing peroxisome proliferator-activated receptor (PPAR)-dependent mechanism. Sprague-Dawley females were exposed by oral route to DEHP alone or associated with vitamin E from gestation day (GD) 12.5 to postnatal day (PND) 3 according to the following treatment regimens: vehicle control (corn oil), vitamin E (200 mg/kg)+corn oil, DEHP (500 mg/kg)+corn oil, and DEHP (500 mg/kg)+vitamin E (200 mg/kg)+corn oil. Variables including litter size, sex ratio, pup weight, post-implantation losses, and the number of viable pups were also assessed. Three male pups per litter were randomly selected and necropsied to measure paired testes weight, apoptosis, and gene expression on PND 3. To evaluate the long-term protective effects of vitamin E, three randomly selected males were necropsied to measure testis histology on PND 70. Supplementation of vitamin E (200 mg/kg) reduced malformations, increased testes weight and prevented the maternal bodyweight loss induced by DEHP. Litter size, sex ratio, and number of viable pups were unaffected, but vitamin E co-administration declined testicular cell apoptosis, decreased the PPARs expression, and protected testis histology. Vitamin E cotreatment showed protective effects against DEHP-induced testicular toxicity, including reproductive malformations, testicular weight, apoptosis and histology, and the mechanisms maybe associated with PPARs.

  1. Storage of platelets on flatbed agitators in polyvinyl chloride blood bags plasticized with tri(2-ethylhexyl) trimellitate.

    PubMed

    Champion, A B; Chong, C; Carmen, R A

    1987-01-01

    Data are presented showing that platelets in polyvinyl chloride blood bags plasticized with tri(2-ethylhexyl) trimellitate can be stored on flatbed agitators (shakers) without the pH falling below 6.0. The lowest pH seen after 7 days of storage in 46 units with platelet yields ranging from 3.6 to 13.3 X 10(10) per unit was 6.43. These bags have a O2 transmission rate of 13.3 mumol per hour per bag. Platelet bags with a O2 transmission rate of 7.9 mumol per hour per bag experience a pH fall after 5 days of storage on the shaker in units whose platelet yield on average exceeds 10 X 10(10). Platelets can be stored on first-generation shakers (70 cycles/min, stroke = 1 inch) without an attempt at manual resuspension of the platelet button. The count after 30 minutes on the shaker averaged 89 +/- 15 percent of the expected count, indicating that resuspension was nearly complete after a relatively short period. Red cells, but not platelets, settled out during storage on the shaker.

  2. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials.

    PubMed

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains.

  3. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials

    PubMed Central

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains. PMID:22934997

  4. In vitro dermal absorption of di(2-ethylhexyl) adipate (DEHA) in a roll-on deodorant using human skin.

    PubMed

    Zhou, Simon Ningsun; Moody, Richard P; Aikawa, Bio; Yip, Anna; Wang, Bing; Zhu, Jiping

    2013-01-01

    In vitro dermal absorption experiments were conducted using a roll-on deodorant that contains 1.56% di(2-ethylhexyl) adipate (DEHA), a plasticizer widely used in consumer products. Human skin specimens were fitted in Bronaugh flow-through Teflon diffusion cells. The diffusion cells were maintained at 32 °C to reflect the skin temperature. Two amounts (low dose: 5 mg of the product; high dose: 100 mg) were applied, in triplicate, each on four different human skins. DEHA was determined in the receiver solution at 6-h intervals, using headspace solid-phase microextraction gas chromatography-mass spectrometry (GC-MS). After 24 h, the experiment was terminated and masses of DEHA in the skin depot, skin wash, and upper and lower chambers of the diffusion cell were determined. A significant portion of applied DEHA, 28% in the low amount application and 34% in the high one, was found in the skin depot. In comparison, only 0.04% and 0.002% of applied DEHA were found in the receiver solutions for the low and high doses, respectively. Under our experimental conditions, an apparent steady-state flux of low DEHA mass penetrating from skin into the receiver solution was observed with a penetration rate of 2.2 ng/cm(2)/h for both the low and high doses. The average mass recovery was 81% for the low dose application and 56% for the high dose.

  5. Maternal exposure to di-(2-ethylhexyl) phthalate exposure deregulates blood pressure, adiposity, cholesterol metabolism and social interaction in mouse offspring.

    PubMed

    Lee, Kuan-I; Chiang, Chin-Wei; Lin, Hui-Ching; Zhao, Jin-Feng; Li, Cheng-Ta; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2016-05-01

    Long-term exposure to di-(2-ethylhexyl) phthalate (DEHP) is highly associated with carcinogenicity, fetotoxicity, psychological disorders and metabolic diseases, but the detrimental effects and mechanisms are not fully understood. We investigated the effect of exposing mouse mothers to DEHP, and the underlying mechanism, on blood pressure, obesity and cholesterol metabolism as well as psychological and learning behaviors in offspring. Tail-cuff plethysmography was used for blood pressure measurement; Western blot used was for phosphorylation and expression of protein; hematoxylin and eosin staining, Nissl staining and Golgi staining were used for histological examination. The serum levels of cholesterol, triglycerides and glucose were measured by blood biochemical analysis. Hepatic cholesterol and triglyceride levels were assessed by colorimetric assay kits. Offspring behaviors were evaluated by open-field activity, elevated plus maze, social preference test and Morris water maze. Maternal DEHP exposure deregulated the phosphorylation of endothelial nitric oxide synthase and upregulated angiotensin type 1 receptor in offspring, which led to increased blood pressure. It led to obesity in offspring by increasing the size of adipocytes in white adipose tissue and number of adipocytes in brown adipose tissue. It increased the serum level of cholesterol in offspring by decreasing the hepatic capacity for cholesterol clearance. The impaired social interaction ability induced by maternal DEHP exposure might be due to abnormal neuronal development. Collectively, our findings provide new evidence that maternal exposure to DEHP has a lasting effect on the physiological functions of the vascular system, adipose tissue and nerve system in offspring.

  6. Antagonistic effects of testosterone and the endocrine disruptor mono-(2-ethylhexyl) phthalate on INSL3 transcription in Leydig cells.

    PubMed

    Laguë, Eric; Tremblay, Jacques J

    2008-09-01

    Insulin-like 3 (INSL3) is a small peptide produced by testicular Leydig cells throughout embryonic and postnatal life and by theca and luteal cells of the adult ovary. During fetal life, INSL3 regulates testicular descent in males, whereas in adults, it acts as an antiapoptotic factor for germ cells in males and as a follicle selection and survival factor in females. Despite its considerable roles in the reproductive system, the mechanisms that regulate Insl3 expression remain poorly understood. There is accumulating evidence suggesting that androgens might regulate Insl3 expression in Leydig cells, but transcriptional data are still lacking. We now report that testosterone does increase Insl3 mRNA levels in a Leydig cell line and primary Leydig cells. We also show that testosterone activates the activity of the Insl3 promoter from different species. In addition, the testosterone-stimulating effects on Insl3 mRNA levels and promoter activity require the androgen receptor. We have mapped the testosterone-responsive element to the proximal Insl3 promoter region. This region, however, lacks a consensus androgen response element, suggesting an indirect mechanism of action. Finally we show that mono-(2-ethylhexyl) phthalate, a widely distributed endocrine disruptor with antiandrogenic activity previously shown to inhibit Insl3 expression in vivo, represses Insl3 transcription, at least in part, by antagonizing testosterone/androgen receptor action. All together our data provide important new insights into the regulation of Insl3 transcription in Leydig cells and the mode of action of phthalates.

  7. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    SciTech Connect

    Tonk, Elisa C.M.; Verhoef, Aart; Gremmer, Eric R.; Loveren, Henk van; Piersma, Aldert H.

    2012-04-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

  8. Effects of di(2-ethylhexyl) phthalate (DEHP) on female fertility and adipogenesis in C3H/N mice.

    PubMed

    Schmidt, Juliane-Susanne; Schaedlich, Kristina; Fiandanese, Nadia; Pocar, Paola; Fischer, Bernd

    2012-08-01

    Di(2-ethylhexyl) phthalate (DEHP) and its metabolites are known to affect lipid metabolism and adipogenesis, mainly by activation of peroxisome proliferator-activated receptors (PPARs). Exposure to DEHP has been linked with testicular impairment and male subfertility. However, the effects of DEHP on female reproductive health and metabolism have not been studied in detail. We examined the effects of dietary DEHP exposure on metabolism and fertility in female mice. In two independent approaches, female C3H/N mice were exposed to DEHP (0.05, 5, or 500 mg/kg of body weight per day) via their diet for 8 weeks, and we recorded food intake, weight gain, and litter size. After exposure, liver, visceral fat, and plasma from F0 females (study I) and F0 dams and their F1 offspring (study II) were analyzed by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. In study I, DEHP-exposed F0 females (all dose groups) had a significant increase in body weight, food intake, and visceral adipose tissue compared with controls. In the 500-mg DEHP group, PPARα and PPARγ transcripts were significantly changed in liver tissue. In the same group, PPARγ mRNA was significantly reduced in liver but not in fat tissue. In addition, leptin and FABP4 (fatty acid binding protein 4) mRNA were increased in adipose tissue, whereas adiponectin was decreased. In study II, we detected a 100% abortion rate in F0 dams in the 500-mg group. F1 offspring exposed in utero and during lactation had an increase in visceral fat tissue and body weight. Fertility was impaired in mice exposed to high doses of DEHP, and body weight and visceral fat deposits were increased in mice exposed to environmentally relevant doses. Although F1 mice were exposed to DEHP only in utero and during lactation, we observed metabolic changes in the offspring of diet-exposed females.

  9. Environmental exposure to di-2-ethylhexyl phthalate is associated with low interest in sexual activity in premenopausal women.

    PubMed

    Barrett, Emily S; Parlett, Lauren E; Wang, Christina; Drobnis, Erma Z; Redmon, J Bruce; Swan, Shanna H

    2014-11-01

    Phthalates, a ubiquitous class of environmental chemicals, may interfere with typical reproductive hormone production both in utero and in adulthood. Although they are best known as anti-androgens, increasingly, evidence suggests that phthalates, particularly di-2-ethylhexyl phthalate (DEHP), may also suppress estrogen production. Given that both androgens and estrogens are essential for sexual function, particularly sexual interest, it is plausible that adult exposure to phthalates alters sexual function. To this end, we used data from 360 women participating in a pregnancy cohort study (the Study for Future Families) to examine whether urinary phthalate metabolite concentrations were associated with two dimensions of self-reported sexual dysfunction in the months prior to conception: lack of sexual interest and vaginal dryness. Women in the highest quartile of urinary concentrations of mono-2-ethyl-5-hydroxyhexyl phthalate, a DEHP metabolite, had 2.58 (95% CI 1.33, 5.00) times the adjusted odds of reporting that they almost always or often lacked interest in sexual activity, and results were similar for mono-2-ethyl-5-oxohexyl phthalate (aOR: 2.56, 95% CI 1.32, 4.95), another DEHP metabolite. Self-reported vaginal dryness was not associated with any phthalate metabolite concentration. This study is novel in its focus on sexual function in relation to environmentally relevant (rather than occupational) exposure to phthalates in adult women and these preliminary findings merit replication in a large, prospective study. Better understanding how adult exposure to phthalates may affect reproductive health, including sexual function, is of public health interest given that virtually all Westerners are exposed to phthalates.

  10. Influence of lipid type on bis (2-ethylhexyl)phthalate (DEHP) leaching from infusion line sets in parenteral nutrition.

    PubMed

    Bagel, Sandrine; Dessaigne, Bérangère; Bourdeaux, Daniel; Boyer, Anne; Bouteloup, Corinne; Bazin, Jean-Etienne; Chopineau, Jean; Sautou, Valérie

    2011-11-01

    Bis(2-ethylhexyl)phthalate (or DEHP) is widely used in polyvinyl chloride (PVC) tubings for its good plasticizing properties. Because it is not covalently bound to the plastic matrix, it is able to escape from PVC during the infusion of the lipid emulsions used in parenteral nutrition (PN). This creates a vector through which it can enter into contact with the patient via the nutrition admixtures infused. This study was designed to assess the potential role of the type of lipids used in PN admixtures on the quantity of DEHP leached out from PVC-based tubings. PVC-based infusion lines, 6 commercially available lipid emulsions, and their oil base components were left in direct contact, and the amount of DEHP leached was measured by liquid chromatography. After a 24-hour exposure period, DEHP migration varied significantly (P = .0000152) according to lipid type. The olive oil-based emulsion Clinoleic leached the most DEHP (65.8 µg/mL intravenous fat emulsion), followed by the fish oil-based emulsion Omegaven (37.8 µg/mL). The soybean oil-based emulsions Intralipid, Medialipide, Lipidem, and Structolipid showed comparable performances, with DEHP leaching rates into the emulsion measured at 27.3, 27.8, 23.6, and 19.6 µg/mL, respectively. Results from the same experiments run on pure-form oils (soybean oil, olive oil, coconut oil, and cod liver oil) confirmed the influence of lipid type on DEHP leaching. The major DEHP leaching caused by olive oil-based emulsions raises cause for concern because DEHP presents distinctive toxic effects, including an increased risk of cholestasis.

  11. Evaluation of a predictive mathematical model of di-(2-ethylhexyl) adipate plasticizer migration from PVC film into foods.

    PubMed

    Mercer, A; Castle, L; Comyn, J; Gilbert, J

    1990-01-01

    The diffusion coefficient of the plasticizer di-(2-ethylhexyl)adipate (DEHA) in Cheddar cheese (Df) was determined by measuring the extent to which DEHA penetrated cheese that was placed in intimate contact with artificially DEHA-contaminated cheese. Slices (20 microns) of cheese from the boundary layer, into which DEHA had migrated, were microtomed at -40 degrees C, and analyzed for DEHA by gas chromatography (GC). Mean values of Df determined by graph fitting experimental and calculated data were 1.5 x 10(-9) cm2 s-1 at 5 degrees C and 3.0 x 10(-8) cm2 s-1 at 25 degrees C. The partition coefficient (K) of DEHA between cheese and PVC film was derived from the partition coefficients of DEHA between acetonitrile (ACN) and cheese lipid, ACN and cheese solid, and ACN and PVC film. The mean values of K between cheese and PVC film were estimated to be 0.70 at 5 degrees C and 0.58 at 25 degrees C. The estimated values of Df and K were then used in a mathematical model (Till et al. 1982) to predict migration levels of DEHA into cheese. Good agreement with previously published experimental data was obtained. Extrapolation of the prediction of DEHA migration into fatty foods, such as salami and avocado, was also successful (ratio of experimental to predicted results within a factor of two). The values of Df and K for cheese are, however, inappropriate for modelling non-fatty foods such as meat, cakes, fruit and vegetables. Predicted values for these foods were typically 3-10-fold too high. More accurate predictions would probably be obtained if values of Df more relevant to these foods are used. The predictions were relatively insensitive to the value of K.

  12. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag.

    PubMed

    Pradeep, S; Benjamin, Sailas

    2012-10-15

    This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (~0.15-0.35 g/g BB; OD ~7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue.

  13. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    SciTech Connect

    Hannon, Patrick R. Brannick, Katherine E. Wang, Wei Gupta, Rupesh K. Flaws, Jodi A.

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  14. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    PubMed Central

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1-100μg/ml) for 24-96 hr to establish the temporal effects of DEHP on the follicle. Following 24-96 hr of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydorxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. PMID:25701202

  15. Effect of mono-(2-ethylhexyl) phthalate on human and mouse fetal testis: In vitro and in vivo approaches

    SciTech Connect

    Muczynski, V.; Cravedi, J.P.; Lehraiki, A.; Levacher, C.; Moison, D.; Lecureuil, C.; Messiaen, S.; Perdu, E.; Frydman, R.; Habert, R.; and others

    2012-05-15

    The present study was conducted to determine whether exposure to the mono-(2-ethylhexyl) phthalate (MEHP) represents a genuine threat to male human reproductive function. To this aim, we investigated the effects on human male fetal germ cells of a 10{sup −5} M exposure. This dose is slightly above the mean concentrations found in human fetal cord blood samples by biomonitoring studies. The in vitro experimental approach was further validated for phthalate toxicity assessment by comparing the effects of in vitro and in vivo exposure in mouse testes. Human fetal testes were recovered during the first trimester (7–12 weeks) of gestation and cultured in the presence or not of 10{sup −5} M MEHP for three days. Apoptosis was quantified by measuring the percentage of Caspase-3 positive germ cells. The concentration of phthalate reaching the fetal gonads was determined by radioactivity measurements, after incubations with {sup 14}C-MEHP. A 10{sup −5} M exposure significantly increased the rate of apoptosis in human male fetal germ cells. The intratesticular MEHP concentration measured corresponded to the concentration added in vitro to the culture medium. Furthermore, a comparable effect on germ cell apoptosis in mouse fetal testes was induced both in vitro and in vivo. This study suggests that this 10{sup −5} M exposure is sufficient to induce changes to the in vivo development of the human fetal male germ cells. -- Highlights: ► 10{sup −5} M of MEHP impairs germ cell development in the human fetal testis. ► Organotypic culture is a suitable approach to investigate phthalate effects in human. ► MEHP is not metabolized in the human fetal testis. ► In mice, MEHP triggers similar effects both in vivo and in vitro.

  16. Direct and transgenerational effects of low doses of perinatal di-(2-ethylhexyl) phthalate (DEHP) on social behaviors in mice

    PubMed Central

    Snyder, Rodney W.; Sumner, Susan S.; Rissman, Emilie F.

    2017-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is an endocrine disrupting chemical commonly used as a plasticizer in medical equipment, food packaging, flooring, and children’s toys. DEHP exposure during early development has been associated with adverse neurobehavioral outcomes in children. In animal models, early exposure to DEHP results in abnormal development of the reproductive system as well as altered behavior and neurodevelopment. Based on these data, we hypothesized that developmental exposure to DEHP would decrease social interactions and increase anxiety-like behaviors in mice in a dose-dependent manner, and that the effects would persist over generations. C57BL/6J mice consumed one of three DEHP doses (0, 5, 40, and 400 μg/kg body weight) throughout pregnancy and during the first ten days of lactation. The two higher doses yielded detectable levels of DEHP metabolites in serum. Pairs of mice from control, low, and high DEHP doses were bred to create three dose lineages in the third generation (F3). Average anogenital index (AGI: anogenital distance/body weight) was decreased in F1 males exposed to the low dose of DEHP and in F1 females exposed to the highest dose. In F1 mice, juvenile pairs from the two highest DEHP dose groups displayed fewer socially investigative behaviors and more exploratory behaviors as compared with control mice. The effect of DEHP on these behaviors was reversed in F3 mice as compared with F1 mice. F1 mice exposed to low and medium DEHP doses spent more time in the closed arms of the elevated plus maze than controls, indicating increased anxiety-like behavior. The generation-dependent effects on behavior and AGI suggest complex mechanisms by which DEHP directly impacts reproductive and neurobehavioral development and influences germline-inherited traits. PMID:28199414

  17. Maternal in utero exposure to the endocrine disruptor di-(2-ethylhexyl) phthalate affects the blood pressure of adult male offspring

    SciTech Connect

    Martinez–Arguelles, D.B.; McIntosh, M.; Rohlicek, C.V.; Culty, M.; Zirkin, B.R.; Papadopoulos, V.

    2013-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used industrially to add flexibility to polyvinyl chloride (PVC) polymers and is ubiquitously found in the environment, with evidence of prenatal, perinatal and early infant exposure in humans. In utero exposure to DEHP decreases circulating testosterone levels in the adult rat. In addition, DEHP reduces the expression of the angiotensin II receptors in the adrenal gland, resulting in decreased circulating aldosterone levels. The latter may have important effects on water and electrolyte balance as well as systemic arterial blood pressure. Therefore, we determined the effects of in utero exposure to DEHP on systemic arterial blood pressure in the young (2 month-old) and older (6.5 month-old) adult rats. Sprague-Dawley pregnant dams were exposed from gestational day 14 until birth to 300 mg DEHP/kg/day. Blood pressure, heart rate, and activity data were collected using an intra-aortal transmitter in the male offspring at postnatal day (PND) 60 and PND200. A low (0.01%) and high-salt (8%) diet was used to challenge the animals at PND200. In utero exposure to DEHP resulted in reduced activity at PND60. At PND200, systolic and diastolic systemic arterial pressures as well as activity were reduced in response to DEHP exposure. This is the first evidence showing that in utero exposure to DEHP has cardiovascular and behavioral effects in the adult male offspring. Highlights: ► In utero exposure to 300 mg DEHP/kg/day decreases activity at postnatal day 60. ► In utero exposure to DEHP decreases aldosterone levels at postnatal day 200. ► In utero exposure to DEHP decreases systolic blood pressure at postnatal day 200. ► An 8% salt diet recovers the decreased blood pressure at postnatal day 200.

  18. Exposure to di-2-ethylhexyl phthalate, di-n-butyl phthalate and bisphenol A through infant formulas.

    PubMed

    Cirillo, Teresa; Latini, Giuseppe; Castaldi, Maria Antonietta; Dipaola, Lucia; Fasano, Evelina; Esposito, Francesco; Scognamiglio, Gelsomina; Francesco, Fabio Di; Cobellis, Luigi

    2015-04-01

    Phthalates and bisphenol A (BPA) are ubiquitous contaminants identified as endocrine disruptors. Phthalates are worldwide used as plasticizers, in particular to improve the mechanical properties of polymers such as polyvinyl chloride. Because they are not chemically bound to the polymer, they tend to leach out with time and use. Di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the two most common phthalates. BPA is an estrogenic compound used to manufacture polycarbonate containers for food and drink, including baby bottles. It can migrate from container into foods, especially at elevated temperatures. Diet is a predominant source of exposure for phthalates and BPA, especially for infants. The aim of this study was to test the presence of DEHP, DnBP, and BPA in infant formulas. DEHP, DnBP, and BPA concentrations were measured in 22 liquid and 28 powder milks by gas chromatography with flame ionization detection and high performance liquid chromatography with fluorimetric detection, respectively. DEHP concentrations in our samples were between 0.005 and 5.088 μg/g (median 0.906 μg/g), DnBP concentrations were between 0.008 and 1.297 μg/g (median 0.053 μg/g), and BPA concentrations were between 0.003 and 0.375 μg/g (median 0.015 μg/g). Concentrations of the investigated contaminants in liquid and powder milks were not significantly different, even though samples were packed in different types of containers. These data point out potential hazards for infants fed with baby formulas. Contamination seems more related to the production of formulas than to a release from containers.

  19. Expression of Chironomus riparius serine-type endopeptidase gene under di-(2-ethylhexyl)-phthalate (DEHP) exposure.

    PubMed

    Park, Kiyun; Kwak, Inn-Sil

    2008-11-01

    Environmental stressors can induce changes in gene expression that can be useful as biomarkers. To identify potential biomarkers of water quality, we characterized full-length cDNA sequences of the serine-type endopeptidase (SP) gene from Chironomus riparius. Their expression was analyzed during different life-history stages and in response to treatment with various concentrations of di(2-ethylhexyl) phthalate (DEHP) for short and long periods of time. A comparative molecular and phylogenetic investigation was then conducted among different orders of insects using sequence database analysis. The sequence of the C. riparius SP gene was found to be most closely related to the sequence of SPs isolated from Aedes aegypti. In addition, the basal level of C. riparius SP mRNA was more highly expressed in larvae than in other life-history stages. However, the expression of C. riparius SP was primarily limited to the gut in larvae. When the effects of short-term exposure to DEHP were evaluated, C. riparius SP gene expression decreased within 1 h of treatment, regardless of dose. We also investigated expression of the C. riparius SP gene following long-term DEHP exposure (10 days) and found that it decreased significantly across all DEHP dosages. Finally, the response of the SP gene was more sensitive in C. riparius that were exposed to low concentrations of DEHP than in those that were exposed to high concentrations. These results show that suppression of the C. riparius SP gene by DEHP is as a potential biomarker that could be useful for monitoring aquatic quality.

  20. Di (2-ethylhexyl) phthalate exposure impairs meiotic progression and DNA damage repair in fetal mouse oocytes in vitro

    PubMed Central

    Liu, Jing-Cai; Lai, Fang-Nong; Li, Ling; Sun, Xiao-Feng; Cheng, Shun-Feng; Ge, Wei; Wang, Yu-Feng; Li, Lan; Zhang, Xi-Feng; De Felici, Massimo; Dyce, Paul W; Shen, Wei

    2017-01-01

    Di (2-ethylhexyl) phthalate (DEHP), is the most common member of the class of phthalates that are used as plasticizers and have become common environmental contaminants. A number of studies have shown that DEHP exposure impacts reproductive health in both male and female mammals by acting as an estrogen analog. Here, we investigated the effects of DEHP on meiotic progression of fetal mouse oocytes by using an in vitro model of ovarian tissue culture. The results showed that 10 or 100 μM DEHP exposure inhibited the progression of oocytes throughout meiotic prophase I, specifically from the pachytene to diplotene stages. DEHP possibly impairs the ability to repair DNA double-strand breaks induced by meiotic recombination and as a consequence activates a pachytene check point. At later stages, such defects led to an increased number of oocytes showing apoptotic markers (TUNEL staining, expression of pro-apoptotic genes), resulting in reduced oocyte survival, gap junctions, and follicle assembly in the ovarian tissues. Microarray analysis of ovarian tissues exposed to DEHP showed altered expression of several genes including some involved in apoptosis and gonad development. The expression changes of some genes clustered in cell-cell communication and signal transduction, along with plasma membrane, extracellular matrix and ion channel function classes, were dependent on the DEHP concentration. Together, these results bring new support to the notion that exposure to DEHP during gestation might exert deleterious effects on ovary development, perturbing germ cell meiosis and the expression of genes involved in a wide range of biological processes including ovary development. PMID:28771232

  1. Levels of di-(2-ethylhexyl)phthalate and total phthalate esters in milk, cream, butter and cheese.

    PubMed

    Sharman, M; Read, W A; Castle, L; Gilbert, J

    1994-01-01

    Di-(2-ethylhexyl)phthalate (DEHP) and total phthalate ester plasticizer levels were determined in milk, cream, butter and cheese samples from a variety of sources from three European countries (UK, Norway and Spain). Samples of milk (from Norway) obtained at various stages during collection, transportation and packaging operations showed no apparent trends in phthalate contamination with total phthalate levels (expressed as DEHP equivalents) in the raw milk of between 0.12 and 0.28 mg/kg. On processing the DEHP was concentrated in the cream at levels up to 1.93 mg/kg, whereas low fat milk contained from < 0.01 to 0.07 mg/kg. Retail dairy products (from Spain) were contaminated with < 0.01-0.55 mg/kg DEHP with a maximum total phthalate level of 3.0 mg/kg in cream samples. UK pooled milk samples from doorstep delivery (obtained from different regions of the country) contained low levels of DEHP (< 0.01-0.09 mg/kg) and total phthalate (0.06-0.32 mg/kg). Retail UK samples of cheese, butter and other fatty products varied considerably in their levels of contamination, the highest being cheese samples containing 17 mg/kg of DEHP and 114 mg/kg total phthalate. However, the majority of samples contained 0.6-3.0 mg/kg DEHP and 4-20 mg/kg total phthalate. UK cream samples contained levels of 0.2-2.7 mg/kg DEHP and 1.8-19.0 mg/kg total phthalate. The level found in these products was too high to have resulted solely from milk by concentration in the fat phase and must therefore have arisen in other ways.

  2. Molecular dynamics and metadynamics simulations of electrosprayed water nanodroplets including sodium bis(2-ethylhexyl)sulfosuccinate micelles

    NASA Astrophysics Data System (ADS)

    Longhi, Giovanna; Ceselli, Alberto; Fornili, Sandro L.; Turco Liveri, Vincenzo

    2017-05-01

    The behavior of aqueous solutions of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) under conditions of electrospray ionization (ESI) has been investigated by molecular dynamics (MD) and well-tempered metadynamics (WTM) simulations at 300 K and 400 K. We have examined water droplets with initial fixed numbers of water molecules (1000) and AOT- anions (100), and with sodium cations in the range of 70-130. At 300 K, all charged droplets show the water evaporation rate increasing with the absolute value of the initial droplet charge state (Z), accompanied by ejection of an increasing number of solvated sodium ions or by expulsion of AOT- anions depending on the sign of Z and by fragmentation in the case of high |Z|. At 400 K, the water evaporation becomes more rapid and the fission process more extensive. In all cases, the AOTNa molecules, arranged as a direct micelle inside the aqueous system, undergo a rapid inversion in vacuo so that the hydrophilic heads and sodium ions surrounded by water molecules move toward the droplet interior. At the end of the 100-ns MD simulations, some water molecules remain within the aggregates at both temperatures. The subsequent metadynamics simulations accelerate the droplet evolution and show that all systems become anhydrous, in agreement with the experimental results of ESI mass spectrometry. This complete water loss is accompanied by sodium counterion emission for positively charged aggregates at 300 K. The analysis shows how the temperature and droplet charge state affect the populations of the generated surfactant aggregates, providing information potentially useful in designing future ESI experimental conditions.

  3. Effects of di(2-ethylhexyl) phthalate on gap and tight junction protein expression in the testis of prepubertal rats.

    PubMed

    Sobarzo, Cristian M; Lustig, Livia; Ponzio, Roberto; Suescun, María Olga; Denduchis, Berta

    2009-11-01

    The aim of this study was to analyze whether di(2-ethylhexyl) phthalate (DEHP), a Sertoli and Leydig cell toxicant, is able to induce alterations in the expression of testicular gap and tight junction proteins. DEHP was administered by gavage (1 g/5 mL corn oil/kg body weight/day) to 25-day-old male Sprague-Dawley rats for 2 days (DEHP-27d) and control rats were treated with corn-oil vehicle for 2 days (C-27d); animals were killed 24 h after the last treatment. Testes of DEHP-27d rats showed different degrees of germ cell sloughing of seminiferous tubules (ST). No alterations of the blood testis barrier (BTB) by lanthanum tracer study were observed. ST of DEHP-27d rats showed a milder immunofluorescence and more restricted expression of connexin-43 (Cx43) in the adluminal and basal compartment compared to C-27d. In DEHP-27d rats, we found a discontinuous immunofluorescent (IF) pattern for zonula occludens (ZO-1), contrasting with the continuous IF profile observed in C-27d, and a delocalization of claudin-11. A decrease in Cx43 and ZO-1 and no changes in occludin expression were detected by Western blot in the testes of DEHP-27d rats. Results from 57-day-old rats treated with DEHP for 2 days and held for 30 days without treatment showed that the alterations in protein expression induced by DEHP are reversible. However, a delay of spermatogenesis compared to C-57d rats, occurred. Data demonstrated that DEHP does not impair BTB permeability but induces germ cell sloughing that might respond to a down regulation of Cx43 and ZO-1 that alters cell junction proteins.

  4. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content.

  5. Environmental exposure to di-2-ethylhexyl phthalate is associated with low interest in sexual activity in premenopausal women

    PubMed Central

    Barrett, Emily S.; Parlett, Lauren E.; Wang, Christina; Drobnis, Erma Z.; Redmon, J. Bruce; Swan, Shanna H.

    2016-01-01

    Phthalates, a ubiquitous class of environmental chemicals, may interfere with typical reproductive hormone production both in utero and in adulthood. Although they are best known as anti-androgens, increasingly, evidence suggests that phthalates, particularly di-2-ethylhexyl phthalate (DEHP), may also suppress estrogen production. Given that both androgens and estrogens are essential for sexual function, particularly sexual interest, it is plausible that adult exposure to phthalates alters sexual function. To this end, we used data from 360 women participating in a pregnancy cohort study (the Study for Future Families) to examine whether urinary phthalate metabolite concentrations were associated with two dimensions of self-reported sexual dysfunction in the months prior to conception: lack of sexual interest and vaginal dryness. Women in the highest quartile of urinary concentrations of mono-2-ethyl-5-hydroxyhexyl phthalate, a DEHP metabolite, had 2.58 (95% CI 1.33, 5.00) times the adjusted odds of reporting that they almost always or often lacked interest in sexual activity, and results were similar for mono-2-ethyl-5-oxohexyl phthalate (aOR: 2.56, 95% CI 1.32, 4.95), another DEHP metabolite. Self-reported vaginal dryness was not associated with any phthalate metabolite concentration. This study is novel in its focus on sexual function in relation to environmentally relevant (rather than occupational) exposure to phthalates in adult women and these preliminary findings merit replication in a large, prospective study. Better understanding how adult exposure to phthalates may affect reproductive health, including sexual function, is of public health interest given that virtually all Westerners are exposed to phthalates. PMID:25448532

  6. Dispersion and attenuation on the Brillouin sound waves of a lubricant: Di(2-ethylhexyl) sebacate under high pressures

    NASA Astrophysics Data System (ADS)

    Fujita, Yoshitaka; Kobayashi, Hiroshi

    2011-08-01

    The Brillouin spectra of di(2-ethylhexyl) sebacate, which is a liquid lubricant known as DOS, were measured at up to 5 GPa at 25 °C and up to 2.5 GPa at 80 °C. At 25 °C, the Brillouin frequency linewidth (acoustic attenuation) has a large maximum at 0.1 MPa, and at 80 °C, it has a large broad maximum at 0.8 GPa. The Brillouin frequency shift (sound velocity) and linewidth obtained indicate that the large dispersion of the sound velocities of DOS occurs from 0.1 MPa at 25 °C and from 0.8 GPa at 80 °C. The origins of this attenuation and dispersion are discussed on the basis of the theory for a viscoelastic liquid. It is proposed that the large acoustic attenuation and dispersion of DOS are due to the production of higher-rank structures with nano-order domains in a polymeric liquid by pressurization. The results show that DOS is strongly viscoelastic above 0.8 GPa at 80 °C, but it is not viscous below 0.8 GPa at 80 °C, with the disappearance of the frequency dispersion. The result obtained is used to explain a limiting shear stress observed in a traction oil. Above a given sliding speed, the oil reaches the region of temperature and pressure in which its viscosity decreases with increasing shear rate and conveys a constant torque above some high shear rate. Then, the oil flows as a plastic solid at a limiting shear stress. These findings regarding the dynamical properties of DOS under high pressures are very useful for the production and analysis of lubricants and traction oils.

  7. Mono-(2-ethylhexyl)-phthalate (MEHP) affects ERK-dependent GDNF signalling in mouse stem-progenitor spermatogonia.

    PubMed

    Lucas, Benjamin E G; Fields, Christopher; Joshi, Neeraj; Hofmann, Marie-Claude

    2012-09-04

    Many commercial and household products such as lubricants, cosmetics, plastics, and paint contain phthalates, in particular bis-(2-ethyhexyl)-phthalate (DEHP). As a consequence, phthalates have been found in a number of locations and foods (streambeds, household dust, bottled water and dairy products). Epidemiological and animal studies analysing phthalate exposure in males provide evidence of degradation in sperm quality, associated to an increase in the incidence of genital birth defects and testicular cancers. In the testis, spermatogenesis is maintained throughout life by a small number of spermatogonial stem cells (SSCs) that self-renew or differentiate to produce adequate numbers of spermatozoa. Disruption or alteration of SSC self-renewal induce decreased sperm count and sperm quality, or may potentially lead to testicular cancer. GDNF, or glial cell-line-derived neurotrophic factor, is a growth factor that is essential for the self-renewal of SSCs and continuous spermatogenesis. In the present study, the SSC-derived cell line C18-4 was used as a model for preliminary assessment of the effects of mono-(2-ethylhexyl)-phthalate (MEHP, main metabolite of DEHP) on spermatogonial stem cells. Our data demonstrate that MEHP disrupts one of the known GDNF signalling pathways in these cells. MEHP induced a decrease of C18-4 cell viability in a time- and dose-dependent manner, as well as a disruption of ERK1/2 activation but not of SRC signalling. As a result, we observed a decrease of expression of the transcription factor FOS, which is downstream of the GDNF/ERK1/2 axis in these cells. Taken together, our data suggest that MEHP exposure affects SSC proliferation through inhibition of specific signalling molecules. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

    PubMed

    Erythropel, Hanno C; Maric, Milan; Nicell, Jim A; Leask, Richard L; Yargeau, Viviane

    2014-12-01

    Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are

  9. The role of adsorption of sodium bis(2-ethylhexyl) sulfosuccinate in wetting of glass and poly(methyl methacrylate) surface

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2008-02-01

    Advancing contact angles, θ, for aqueous solutions of the anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were measured on glass and poly(methyl methacrylate) (PMMA) surface. Using the obtained results we determined the properties of aqueous AOT solutions in wetting of these surfaces. It occurs that the wettability of glass and PMMA by these solutions depends on the concentration of AOT in solution. There is almost linear dependence between the contact angle ( θ) and concentration of AOT (log C) in the range from 5 × 10 -4 to 2.5 × 10 -3 M/dm 3 (value of the critical micelle concentration of AOT—CMC) both for glass and PMMA surface. For calculations of AOT adsorption at solid (glass, PMMA)-solution drop-air system interfaces the relationship between the adhesion tension ( γLV cos θ) and surface tension ( γLV) and the Gibbs and Young equations were taken into account. From the measurement and calculation results the slope of the γLV cos θ - γ LV curve was found to be constant and equal 0.7 for glass and -0.1 for PMMA over the whole range of AOT concentration in solution. From this fact it can be concluded that if ΓSV is equal zero then ΓSL > 0 for the PMMA-solution and ΓSL < 0 for glass-solution systems. It means that surfactant concentration excess at PMMA-solution interface is considerably lower than at solution-air interface, but this excess of AOT concentration at glass-solution interface is lower than in the bulk phase. By extrapolating the linear dependence between the adhesion and surface tension the value of the critical surface tension ( γc) of wetting for glass and PMMA was also determined, that equaled 25.9 and 25.6 mN/m for glass and PMMA, respectively. Using the value of the glass and PMMA surface tension as well as the measured surface tension of aqueous AOT solutions in Young equation, the solid-liquid interface tension ( γSL) was found. There was a linear dependence between the γSL and γLV both for glass and PMMA

  10. Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign.

    PubMed

    Petersen, J H; Breindahl, T

    1998-07-01

    A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was

  11. Toxic effects of polyethylene terephthalate microparticles and Di(2-ethylhexyl)phthalate on the calanoid copepod, Parvocalanus crassirostris.

    PubMed

    Heindler, Franz M; Alajmi, Fahad; Huerlimann, Roger; Zeng, Chaoshu; Newman, Stephen J; Vamvounis, George; van Herwerden, Lynne

    2017-03-30

    Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris. Copepods were exposed to DEHP for 48h to assess toxicity. Adults were very healthy following chemical exposure (up to 5120µg L(-1)), whereas nauplii were severely affected at very low concentrations (48h LC50value of 1.04 ng L(-1)). Adults exposed to sub-lethal concentrations of DEHP (0.1-0.3µg L(-1)) or microplastics (10,000-80,000 particles mL(-1)) exhibited substantial reductions in egg production. Populations were exposed to either microplastics or DEHP for 6 days with 18 days of recovery or for 24 days. Populations exposed to microplastics for 24 days significantly depleted in population size (60±4.1%, p<0.001) relative to controls, whilst populations exposed for only 6 days (with 18 days of recovery) experienced less severe depletions (75±6.0% of control, p<0.05). Populations exposed to DEHP, however, exhibited no recovery and both treatments (6 and 24 days) yielded the same average population size at the termination of the experiment (59±4.9% and 59±3.4% compared to control; p<0.001). These results suggest that DEHP may induce reproductive disorders that can be inherited by subsequent generations. Histone 3 (H3) was significantly (p<0.05) upregulated in both plastic and DEHP treatments after 6 days of exposure, but not after 18 days of recovery. Hsp70-like expression showed to be unresponsive to either DEHP or microplastic exposure. Clearly, microplastics and plasticizers pose a serious threat to zooplankton and potentially to higher trophic levels.

  12. Anti-leukaemic and anti-mutagenic effects of di(2-ethylhexyl)phthalate isolated from Aloe vera Linne.

    PubMed

    Lee, K H; Kim, J H; Lim, D S; Kim, C H

    2000-05-01

    Extracts of Aloe vera Linne have been found to exhibit cytotoxicity against human tumour cell lines. This study examines the anti-tumour effects of di(2-ethylhexyl)phthalate (DEHP) isolated from Aloe vera Linne, in human and animal cell lines. Its anti-mutagenic effects were examined using Salmonella typhimurium TA98 and TA100 strains. Growth inhibition was specifically exerted by DEHP against three leukaemic cell lines at concentrations below 100 microg mL(-1). At 100 microg mL(-1) DEHP, K562, HL60 and U937 leukaemic cell lines showed growth inhibition of 95, 97 and 95%, respectively. DEHP exhibited an inhibitory activity of 74, 83 and 81%, respectively, in K562, HL60 and U937 cell lines at a concentration of 10 microg mL(-1). At a concentration of 1 microg mL(-1), DEHP exerted an inhibitory activity of 50, 51 and 52%, respectively, in K562, HL60 and U937. In a normal cell line, MDBK, DEHP exerted 30% growth inhibition at a concentration of 100 microg mL(-1), and showed no inhibitory activity at concentrations below 50 microg mL(-1). It was found that DEHP exerted anti-mutagenic activity in the Salmonella mutation assay. The number of mutant colonies of Salmonella typhimurium strain TA98 upon exposure to AF-2 (0.2 microg/plate) decreased in a concentration-dependent manner in the presence of different DEHP concentrations (decreasing to 90.4, 83.9, 75.4, 69.6 and 46.9%, respectively, for DEHP concentrations of 100, 50, 10, 5 and 1 microg/plate). In the case of Salmonella typhimurium strain TA100, DEHP reduced AF-2-induced mutagenicity at 1, 5, 10, 50 and 100 microg/plate to 57.4, 77.5, 80.0, 89.0 and 91.5%, respectively. The isolated compound from Aloe vera Linne, DEHP, was considered to be the active principle responsible for anti-leukaemic and anti-mutagenic effects in-vitro.

  13. Ultimate biodegradation of dialkyl phthalate ester plasticizers

    SciTech Connect

    Lee, C.L.; Sinko, C.J.; Winkelmann, D.A.; Peterson, D.R.; Parkerton, T.F.

    1995-12-31

    Phthalate Esters (PEs) are primarily used as plasticizers in the polymer industry to impart the desired degree of flexibility to plastic products. The single isomer, di-2-ethylhexyl phthalate (DEHP) is the most common plasticizer. However, other commercially important PE plasticizers possess branched alkyl chains of a mixed isomeric nature. The purpose of this study was to compare the ultimate biodegradability of mixed isomer PEs dihexyl (DHP), diisoheptyl (DIHP), diisononyl (DINP), diisodecyl (DIDP), and diisoundecyl (DIUP) phthalate to DEHP using the standardized OECD test (301 F) which is based on mannometric respirometry. Ultimate biodegradation results after 28 days under unacclimated conditions at 25 C were as follows: DHP (80 {+-} 10%), DIHP (82 {+-} 13%), DEHP (63 {+-} 18%), DINP (70 {+-} 11%), DIDP (67 {+-} 13%), DUP (57 {+-} 14%). These data confirm the readily biodegradable nature of DEHP and mixed isomer PEs reported in previous studies and provide additional data to contradict the misperception that PEs are environmentally persistent. The influence of alkyl chain structure on the rate and extent of biodegradation observed in this and other biodegradation studies are discussed.

  14. Genotoxicity evaluation of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate using a combined rat comet/micronucleus assays.

    PubMed

    Kitamoto, Sachiko; Matsuyama, Ryoko; Uematsu, Yasuaki; Ogata, Keiko; Ota, Mika; Yamada, Toru; Miyata, Kaori; Kimura, Juki; Funabashi, Hitoshi; Saito, Koichi

    2015-07-01

    As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo alkaline comet assay (comet assay), we examined DNA damage in the liver, stomach, and bone marrow of rats dosed orally three times with up to 2000 mg/kg of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate. All three compounds gave negative results in the liver and stomach. In addition, a bone marrow comet and micronucleus analysis revealed that benzene, but not di(2-ethylhexyl) phthalate or trisodium ethylenediamine tetraacetic acid monohydrate induced a significant increase in the median % tail DNA and micronucleated polychromatic erythrocytes, compared with the respective concurrent vehicle control. These results were in good agreement with the previously reported genotoxicity findings for each compound. The present study has shown that combining the micronucleus test with the comet assay and carrying out these analyses simultaneously is effective in clarifying the mechanism of action of genotoxic compounds such as benzene.

  15. Mono-(2-ethylhexyl) phthalate induces apoptosis through miR-16 in human first trimester placental cell line HTR-8/SVneo.

    PubMed

    Meruvu, Sunitha; Zhang, Jian; Bedi, Yudhishtar Singh; Choudhury, Mahua

    2016-03-01

    Phthalates have been linked to adverse pregnancy complications. Mono-(2-ethylhexyl) phthalate, an active metabolite of di-(2-ethylhexyl) phthalate and an endocrine disruptor, has been shown to induce apoptosis in various cell types including placental cells. However, the mechanism of action of MEHP induced apoptosis is still unknown. We hypothesized that apoptosis may be mediated in part through altered microRNA(s) in placenta under MEHP exposure. In the present study, we report that MEHP increases miR-16 expression in a time- and dose-dependent manner (p<0.05), while inducing apoptosis in HTR-8/SVneo. Cells treated with MEHP showed a dose-dependent increase in cytotoxicity and reactive oxygen species along with decreased cell viability. Consistent with significant increase in apoptosis analyzed by flow cytometry, we detected decreased anti-apoptotic BCL-2 at transcriptional and translational levels with MEHP (p<0.05). Knockdown of miR-16 did not decrease the BCL-2/BAX protein expression ratio in the presence of MEHP when compared to negative control demonstrating that MEHP induces apoptosis directly through miR-16. In conclusion, our study demonstrates for the first time that MEHP induces miR-16, which in turn, alters BCL-2/BAX ratio leading to increased apoptosis. This study provides a novel insight into MEHP induced epigenetic regulation in placental apoptosis which may lead to pregnancy complications.

  16. Studies on the formation of formaldehyde during 2-ethylhexyl 4-(dimethylamino)benzoate demethylation in the presence of reactive oxygen and chlorine species.

    PubMed

    Studziński, Waldemar; Gackowska, Alicja; Przybyłek, Maciej; Gaca, Jerzy

    2017-03-01

    In order to protect the skin from UV radiation, personal care products (PCPS) often contain chemical UV-filters. These compounds can enter the environment causing serious consequences on the water ecosystems. The aim of this study was to examine, the effect of different factors, such as UV light, the presence of NaOCl and H2O2 on the formaldehyde formation during popular UV filter, 2-ethylhexyl 4-(dimethylamino)benzoate (ODPABA) demethylation. The concentration of formaldehyde was determined by VIS spectrophotometry after derivatization. The reaction mixtures were qualitatively analyzed using GC/MS chromatography. The highest concentration of formaldehyde was observed in the case of ODPABA/H2O2/UV reaction mixture. In order to describe two types of demethylation mechanisms, namely, radical and ionic, the experimental results were enriched with Fukui function analysis and thermodynamic calculations. In the case of non-irradiated system containing ODPABA and NaOCl, demethylation reaction probably proceeds via ionic mechanism. As it was established, amino nitrogen atom in the ODPABA molecule is the most susceptible site for the HOCl electrophilic attack, which is the first step of ionic demethylation mechanism. In the case of irradiated mixtures, the reaction is probably radical in nature. The results of thermodynamic calculations showed that abstraction of the hydrogen from N(CH3)2 group is more probable than from 2-ethylhexyl moiety, which indicates higher susceptibility of N(CH3)2 to the oxidation.

  17. Maternal Urinary Metabolites of Di-(2-Ethylhexyl) Phthalate in Relation to the Timing of Labor in a US Multicenter Pregnancy Cohort Study

    PubMed Central

    Hauser, Russ; Williams, Paige L.; Whyatt, Robin M.; Calafat, Antonia M.; Nelson, Heather; Herrick, Robert; Swan, Shanna H.

    2009-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer used in consumer and medical products that can cross the placenta, disrupt steroid hormone synthesis, and activate peroxisome proliferator-activated receptor γ. The authors examined DEHP exposure in relation to the timing of labor in a pregnancy cohort study of 283 women recruited in 4 US states (California, Iowa, Minnesota, and Missouri) between 2000 and 2004. The authors estimated associations between concentrations of DEHP metabolites and gestational age at delivery using linear regression models and associations between DEHP metabolites and clinical outcomes using logistic regression models. After covariate adjustment, women at the 75th percentile of DEHP metabolite concentrations had a 2-day-longer mean length of gestation than women at the 25th percentile (95% confidence interval: 1.4, 3.3). Log-unit increases in mono-2-ethylhexyl phthalate and mono-2-ethyl-5-oxohexyl phthalate concentrations were associated with increased odds of cesarean section delivery (30% and 50% increased odds, respectively), increased odds of delivering at 41 weeks or later (100% and 120% increased odds), and reduced odds of preterm delivery (50% and 60% decreased odds). These data suggest that DEHP may interfere with signaling related to the timing of parturition. PMID:19251754

  18. In Utero Exposure to Di-(2-Ethylhexyl) Phthalate Induces Testicular Effects in Neonatal Rats That Are Antagonized by Genistein Cotreatment1

    PubMed Central

    Jones, Steven; Boisvert, Annie; Francois, Sade; Zhang, Liandong; Culty, Martine

    2015-01-01

    Fetal exposure to endocrine disruptors (EDs) is believed to predispose males to reproductive abnormalities. Although males are exposed to combinations of chemicals, few studies have evaluated the effects of ED mixtures at environmentally relevant doses. Our previous work showed that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di-(2-ethylhexyl) phthalate (DEHP) induced unique alterations in adult testis. In this follow-up study, we examined Postnatal Day 3 (PND3) and PND6 male offspring exposed from Gestational Day 14 to parturition to corn oil, 10mg/kg GEN, DEHP, or their combination, to gain insight into the early molecular events driving long-term alterations. DEHP stimulated the mRNA and protein expression of the steroidogenic enzyme HSD3B, uniquely at PND3. DEHP also increased the mRNA expression of Nestin, a Leydig progenitor/Sertoli cell marker, and markers of Sertoli cell (Wt1), gonocyte (Plzf, Foxo1), and proliferation (Pcna) at PND3, while these genes were unchanged by the mixture. Redox (Nqo1, Sod2, Sod3, Trx, Gst, Cat) and xenobiotic transporter (Abcb1b, Abcg2) gene expression was also increased by DEHP at PND3, while attenuated when combined with GEN, suggesting the involvement of cellular stress in short-term DEHP effects and a protective effect of GEN. The direct effects of GEN and mono-(2-ethylhexyl) phthalate, the principal bioactive metabolite of DEHP, on testis were investigated in PND3 organ cultures, showing a stimulatory effect of 10 μM mono-(2-ethylhexyl) phthalate on basal testosterone production that was normalized by GEN. These effects contrasted with previous reports of androgen suppression and decreased gene expression in perinatal rat testis by high DEHP doses, implying that neonatal effects are not predictive of adult effects. We propose that GEN, through an antioxidant action, normalizes reactive oxygen species-induced neonatal effects of DEHP. The notion that these EDs do not follow classical

  19. Solid phase extraction of zinc(II) using a PVC-based polymer inclusion membrane with di(2-ethylhexyl)phosphoric acid (D2EHPA) as the carrier.

    PubMed

    Kolev, Spas D; Baba, Yoshinari; Cattrall, Robert W; Tasaki, Tsutomu; Pereira, Natalie; Perera, Jilska M; Stevens, Geoffrey W

    2009-05-15

    A polymer inclusion membrane (PIM) is reported consisting of 45% (m/m) di(2-ethylhexyl)phosphoric acid (D2EHPA) immobilized in poly(vinyl chloride) (PVC) for use as a solid phase absorbent for selectively extracting Zn(II) from aqueous solutions in the presence of Cd(II), Co(II), Cu(II), Ni(II) and Fe(II). Interference from Fe(III) in the sample is eliminated by precipitation with orthophosphate prior to the extraction of Zn(II). Studies using a dual compartment transport cell have shown that the Zn(II) flux (2.58 x 10(-6)mol m(-2)s(-1)) is comparable to that observed for supported liquid membranes. The stoichiometry of the extracted complex is shown to be ZnR(2).HR, where R is the D2EHPA anion.

  20. pH-Zone refining counter-current chromatography of polar catecholamines using di-(2-ethylhexyl)phosphoric acid as a ligand.

    PubMed

    Ma, Y; Sokoloski, E; Ito, Y

    1996-02-16

    The use of di-(2-ethylhexyl)phosphoric acid (DEHPA) as a ligand in the stationary phase effectively increased the partition coefficient of polar catecholamines. pH-Zone refining counter-current chromatography of six components, i.e. five catecholamines and one amino acid (DOPA), was successfully performed using a two-phase solvent system composed of methyl tert.-butyl ether and water by adding DEHPA (20%) and ammonium acetate (200 mM) to the organic phase and HCl (50 mM) to the aqueous mobile phase. DOPA was eluted first as a normal peak followed by the five catecholamines which formed a succession of highly concentrated rectangular peaks associated with sharp impurity peaks at their borders (UV tracing at 280 nm). Both pH and standard partition coefficient of collected fractions indicated minimum overlap between the main peaks. Each component was identified by NMR analysis.

  1. Acute pulmonary pathology and sudden death in rats following the intravenous administration of the plasticizer, DI (2-ethylhexyl) phthalate, solubilized with Tween surfactants. [pathology of vinyl plastics poisoning

    NASA Technical Reports Server (NTRS)

    Schulz, C. O.; Rubin, R. J.; Hutchins, G. M.

    1975-01-01

    Intravenous administration of 200-300 mg/kg of di(2-ethylhexyl)phthalate (DEHP) solubilized in aqueous solutions of several Tween surfactants caused respiratory distress in rats. There was a dose-dependent lethality with death generally occurring within 90 minutes after injection. The lungs from DEHP:Tween treated animals were enlarged, generally darkened, and in some cases showed hemorrhagic congestion. Neither the overt symptoms nor the morphologic alterations resulting from DEHP:Tween administration could be reproduced by intravenous administration of aqueous Tween solutions alone. The absence of pulmonary abnormalities following the intravenous administration of DEHP as an aqueous emulsion given either alone or even as soon as 2 minutes after pretreatment with Tween 80, suggests that the specific in vivo interaction between DEHP and Tween surfactants depends on the prior formation of water-soluble micelles of DEHP.

  2. UV-vis absorption properties of polyazomethine in base and protonated with 1,2-(di-2-ethylhexyl)ester of 4-sulfophthalic acid form

    NASA Astrophysics Data System (ADS)

    Iwan, Agnieszka; Rannou, Patrice

    2009-09-01

    The UV-vis absorption properties of undoped and doped 1,4-phenylenemethylidynenitrilo-1,4-phenylenenitrilomethylidyne (PAZ) in various temperatures are reported. It is demonstrated that the absorption spectra can be modified not only by changing the temperature from 193 K to 413 K, but also via acid-base doping involving the protonation of nitrogen atom in imine group. The use of special protonating agent, i.e. 1,2-(di-2-ethylhexyl)ester of 4-sulfophthalic acid (PSA) lead to the modification of the absorption spectrum of the PAZ. The imine band in UV-vis spectrum of the doped with the PSA polyazomethine is 85 nm red shifts in comparison with unprotonated one. The thermochromism of PAZ included the conformational changes in the conjugating backbone structure of the undoped and doped polyazomethine.

  3. Urinary metabolites of di(2-ethylhexyl) phthalate relation to sperm motility, reactive oxygen species generation, and apoptosis in polyvinyl chloride workers.

    PubMed

    Huang, Li-Ping; Lee, Ching-Chang; Fan, Jer-Pei; Kuo, Po-Hsiu; Shih, Tung-Sheng; Hsu, Ping-Chi

    2014-08-01

    To measure the concentrations of urinary di(2-ethylhexyl) phthalate (DEHP) metabolites in polyvinyl chloride (PVC) workers and a control group for determining the relationship of DEHP exposure to semen quality, sperm reactive oxygen species (ROS) generation, and sperm apoptosis. We assessed the metabolites of DEHP, namely urinary mono-(2-ethylhexyl) phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and semen quality, such as sperm concentration, motility, morphology, ROS generation, and DNA damage by using terminal deoxynucleotidyl transferase-mediated nick end labeling assay obtained from 47 workers employed within two PVC pellet plants and 15 graduate students in Taiwan. Sperm concentration and motility were significantly affected in the high-exposure group. The percentage and intensity of sperm ROS generation were higher in the high-exposure group than those in the control group. After adjustment for age, smoking status, and coffee consumption, the decrease in sperm motility was inversely associated with the concentration of MEHP (β = -0.549, p = 0.0085), MEHHP (β = -0.155, p = 0.0074), and MEOHP (β = -0.201, p = 0.0041). Moreover, sperm apoptosis and ROS generation were positively associated with MEHHP and MEOHP concentration, respectively. This was the first study to explore the associations between levels of DEHP exposure, sperm motility, ROS generation, and apoptosis. The results suggested that urinary MEHHP and MEOHP were sensitive biomarkers for reflecting the relationship between DEHP exposure and semen quality.

  4. Estimating the contribution of inhalation exposure to di-2-ethylhexyl phthalate (DEHP) for PVC production workers, using personal air sampling and urinary metabolite monitoring.

    PubMed

    Fong, Jer-Pei; Lee, Fang-Jin; Lu, I-Syuan; Uang, Shi-Nian; Lee, Ching-Chang

    2014-01-01

    Because of troubling reports of high urinary metabolite levels and adverse reproductive health effects in workers exposed to di(2-ethylhexyl)phthalate (DEHP) in occupational settings, concern about exposure to DEHP in occupational settings is increasing. However, the contributions of different routes of exposure to DEHP are unclear. We used personal air sampling and biomonitoring to determine the contribution of inhalation exposure to the body burden of DEHP in the workplace. Eighty-nine workers (high-exposure group: 66 raw-materials workers; low-exposure group: 23 administrative workers) were recruited from three polyvinyl chloride (PVC) factories. Urinary levels of mono(2-ethylhexyl) phthalate (MEHP), (mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were measured in pre-shift and post-shift samples. The geometric means of airborne concentrations of DEHP were 5.3 μg/m3 (low-exposure group) and 32.7 μg/m3 (high-exposure group) (P<0.01). Correlation analysis showed a consistently significant association between airborne DEHP concentration and urinary DEHP metabolite levels in the high-exposure group. Calculating daily DEHP intake based on total urinary metabolite levels showed that the geometric means of total daily urinary metabolite levels of DEHP were 9.2 μg/kg/day (low-exposure group) and 15.5 μg/kg/day (high-exposure group) (P<0.01). A quartile analysis of all workers showed a significant trend toward an association between the individual contribution of inhalation exposure to DEHP and urinary DEHP metabolite levels, for which the mean inhalation contribution was 46.7% in the highest quartile. We conclude that inhalation-absorbed airborne DEHP significantly increased the total body burden of DEHP in these occupationally exposed workers.

  5. Preventive effect of D-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury in rat.

    PubMed

    Suna, Shigeru; Yamaguchi, Fuminori; Kimura, Shoji; Tokuda, Masaaki; Jitsunari, Fumihiko

    2007-09-10

    To investigate the preventive effects of d-psicose, one of rare ketohexoses, on di-(2-ethylhexyl) phthalate (DEHP)-induced testicular injury, prepubertal male Sprague-Dawley rats were exposed to DEHP via their diet or orally, while under treatment with d-psicose. The rats given a diet-containing 1% DEHP alone for 7-14 days showed severe testicular atrophy accompanied by aspermatogenesis. On the other hand, those given the diet plus 2% but not 1% d-psicose-supplemented water for 14 days did not develop testicular atrophy, and exhibited an almost complete spermatogenesis. There was no significant difference in plasma mono-(2-ethylhexyl) phthalate (MEHP) levels between the d-psicose-free and d-psicose-treated groups. The testicular malondialdehyde (MDA) level after a single oral administration of 2g/kg of DEHP showed a similar pattern of increase to the plasma MEHP level and peaked in 24h suggesting a close and dose-dependent relation between plasma MEHP and testicular reactive oxygen species (ROS) levels. Pretreatment with d-psicose at a concentration of 2% and 4% resulted in an almost complete but not absolute suppression of testicular MDA production among rats administered 2g/kg of DEHP. The microarray analysis showed the induction of oxidative stress related genes including the thioredoxin, glutathione peroxidase 1 and 2, glutaredoixn 1 after 24h of the DEHP treatment in the testis. These results show that d-psicose prevents DEHP-induced testicular injury by suppressing the generation of ROS in the rat testis. This effect may be due to the direct scavenging by d-psicose of ROS generated in the testis.

  6. Mono(2-ethylhexyl) phthalate induces apoptosis in p53-silenced L02 cells via activation of both mitochondrial and death receptor pathways.

    PubMed

    Yang, Guangtao; Zhang, Wenjuan; Qin, Qizhi; Wang, Jing; Zheng, Hongyan; Xiong, Wei; Yuan, Jing

    2015-09-01

    Mono(2-ethylhexyl) phthalate (MEHP) is one of the main metabolites of di(2-ethylhexyl) phthalate. The evidence shows that DEHP may exert its toxic effects primarily via MEHP, which is 10-fold more potent than its parent compound in toxicity in vitro. MEHP-induced apoptosis is mediated by either p53-dependent or -independent pathway. However, the detailed mechanism of its toxicity remains unclear. In this study, immortalized normal human liver cell line L02 was chosen, as an in vitro model of nonmalignant liver, to elucidate the role of p53 in MEHP-induced apoptosis. The cells were treated with MEHP (6.25, 12.50, 25.00, 50.00, and 100.00 μM) for 24 and 36 h, then small interfering RNA (siRNA) was used to specifically silence p53 gene of L02 cells. The results indicated that MEHP caused oxidative DNA damage and apoptosis in L02 cells were associated with the p53 signaling pathway. Further study found that MEHP (50.00 and 100.00 μM) induced apoptosis in p53-silenced L02 cells, along with the up-regulations of Fas and FasL proteins as well as increased the Bax/Bcl-2 ratio and Caspase 3, 8, and 9 activities. Additionally, both FasL inhibitor (AF-016) and Caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp- fluoromethylketone (Z-VAD-FMK) could prevent the cell apoptosis induced by MEHP. The findings suggested that MEHP-induced apoptosis in L02 cells involving a Caspases-mediated mitochondrial signaling pathway and/or death receptor pathway. p53 was not absolutely necessary for MEHP-induced L02 cell apoptosis.

  7. Differences in metabolite burden of di(2-ethylhexyl)phthalate in pregnant and postpartum dams and their offspring in relation to drug-metabolizing enzymes in mice.

    PubMed

    Hayashi, Yumi; Ito, Yuki; Yanagiba, Yukie; Kamijima, Michihiro; Naito, Hisao; Nakajima, Tamie

    2012-04-01

    Di(2-ethylhexyl)phthalate (DEHP) induced adverse effects on mice offspring, and the metabolite mono(2-ethylhexyl)phthalate (MEHP) may be essential to determine the toxicity. In this experiment, we measured liver MEHP levels and the factors determining the metabolism, two enzyme activities [lipase and uridine 5'-diphosphate-glucuronosyltransferase (UGT)] or expression of cytochrome P450 4A14 (CYP4A14) in dams (on gestational day 18 and postnatal day 2) and their offspring. MEHP concentrations in the liver from pregnant dams were 1.5 times higher than those of postpartum dams at exposure to 0.05% DEHP. Accordingly, MEHP concentrations were 1.7 times higher in fetuses than in pups at the dose. Interestingly, lipase activity was 1.8-fold higher in pregnant dams than postpartum ones, but no such difference was noted in the activity between fetuses and pups. UGT activity was also 1.5-fold higher in pregnant dams than postpartum ones, whereas the activity in the fetuses was 1/2 that of pups. No difference was noted in CYP4A14 levels between pregnant and postpartum mice, whereas the levels in the fetuses were <1/10 those of pups. DEHP exposure did not influence lipase activity, whereas it slightly enhanced UGT activity and exclusively increased CYP4A14 levels in pregnant and/or postpartum dams. Taken together, the higher MEHP levels in pregnant dams than postpartum ones may be primarily due to higher lipase activities in pregnant dams, which may closely reflect those in fetuses and pups.

  8. Phthalate and di-(2-ethylhexyl) adipate (DEHA) intake by German infants based on the results of a duplicate diet study and biomonitoring data (INES 2).

    PubMed

    Fromme, Hermann; Gruber, Ludwig; Schuster, Ralph; Schlummer, Martin; Kiranoglu, Mandy; Bolte, Gabriele; Völkel, Wolfgang

    2013-03-01

    Phthalates as well as di-(2-ethylhexyl) adipate (DEHA) are used as plasticizers in diverse applications and are of toxicological concern. The study was conducted with a study population of 25 German subjects aged between 15 and 21 months. Overall, 16 phthalates and DEHA were measured by gas chromatography-mass spectrometry in a total of 171 duplicate diet samples collected over 7 consecutive days, and 20 phthalate metabolites were analyzed in the urine samples collected over 7 consecutive days using a liquid chromatography-tandem mass spectrometry method. The median "high" daily dietary intake based on 95th percentiles was 4.66 μg/kg b.w. for di-2-ethylhexyl phthalate (DEHP), 1.03 μg/kg b.w. for di-isobutyl phthalate (DiBP), and 0.70 μg/kg b.w. for di-n-butyl phthalate (DnBP), and 1.0 μg/kg b.w. for DEHA. The "high" daily total intake from biomonitoring data was 4.9 μg/kg b.w. for DEHP, 2.2 μg/kg b.w. for DnBP, 3.9 μg/kg b.w. for DiBP, and 2.6 μg/kg b.w. for di-isononyl phthalate. The comparison of the two intake estimates indicates that the dominant intake source of DEHP was food ingestion, whereas other sources considerably contributed to the total intake of other phthalates. Using our "high" intake scenario, none of the analyzed phthalates reached the recommended tolerable daily intake levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Mono(2-ethylhexyl)phthalate and mono-n-butyl phthalate activation of peroxisome proliferator activated-receptors alpha and gamma in breast.

    PubMed

    Venkata, Nagaraj Gopisetty; Robinson, Jodie A; Cabot, Peter J; Davis, Barbara; Monteith, Greg R; Roberts-Thomson, Sarah J

    2006-06-01

    The phthalates di(2-ethylhexyl)phthalate (DEHP) and di-n-butyl phthalate (DBP) are environmental contaminants with significant human exposures. Both compounds are known reproductive toxins in rodents and DEHP also induces rodent hepatocarcinogenesis in a process believed to be mediated via the peroxisome proliferator-activated receptor alpha (PPARalpha). DEHP and DBP are metabolised to their respective monoesters, mono-(2-ethylhexyl)phthalate (MEHP) and mono-n-butyl phthalate (MBP), which are the active metabolites. MEHP also activates another member of the PPAR subfamily, PPARgamma. The effects of PPARalpha and PPARgamma activation in human breast cells appears to be opposing; PPARalpha activators in breast cells cause an increase in proliferation, while PPARgamma activation in breast cells is associated with differentiation and an inhibition of cell proliferation. Further to this the activation of the PPARs is cell and ligand specific, suggesting the importance of examining the effect of MEHP and MBP on the activation of PPARalpha, PPARbeta and PPARgamma in human breast. We used the common model of human breast cancer MCF-7 and examined the ability of MEHP and MBP to activate human PPARs in this system. The ability of MBP and MEHP to block PPAR responses was also assessed. We found that both human PPARalpha and PPARgamma were activated by MEHP whereas MEHP could not activate PPARbeta. MBP was unable to activate any PPAR isoforms in this breast model, despite being a weak peroxisome proliferator in liver, although MBP was an antagonist for both PPARgamma and PPARbeta. Our results suggest that the toxicological consequences of MEHP in the breast could be complex given the opposing effects of PPARalpha and PPARgamma in human breast cells.

  10. Designing greener plasticizers: Effects of alkyl chain length and branching on the biodegradation of maleate based plasticizers.

    PubMed

    Erythropel, Hanno C; Brown, Tobin; Maric, Milan; Nicell, Jim A; Cooper, David G; Leask, Richard L

    2015-09-01

    The ubiquitous presence of the plasticizer di (2-ethylhexyl) phthalate (DEHP) in the environment is of concern due to negative biological effects associated with it and its metabolites. In particular, the metabolite mono (2-ethylhexyl) phthalate (MEHP) is a potential endocrine disruptor. Earlier work had identified the diester di (2-ethylhexyl) maleate (DEHM) as a potential greener candidate plasticizer to replace DEHP, yet its biodegradation rate was reported to be slow. In this study, we modified the side chains of maleate diesters to be linear (i.e., unbranched) alkyl chains that varied in length from ethyl to n-octyl. The plasticization efficiency of these compounds blended into PVC at 29 wt.% increased with the overall length of the molecule, but all compounds performed as well as or better than comparable samples with DEHP. Tests conducted with the equally long DEHM and dihexyl maleate (DHM) showed that branching has no effect on glass transition temperature (Tg) reduction efficiency. Biodegradation experiments with the common soil bacterium Rhodococcus rhodocrous in the presence of the plasticizer showed acceptable hydrolysis rates of maleates with unbranched side chains, while the branched DEHM showed almost no degradation. The addition of hexadecane as auxiliary carbon source improved hydrolysis rates. Temporary buildup of the respective monoester of the compounds were observed, but only in the case of the longest molecule, dioctyl maleate (DOM), did this buildup lead to growth inhibition of the bacteria. Maleates with linear side chains, if designed and tested properly, show promise as potential candidate plasticizers as replacements for DEHP.

  11. NTP Toxicology and Carcinogenesis Studies of Tris(2-ethylhexyl)phosphate (CAS No. 78-42-2) In F344/N Rats and B6C3F1 Mice (Gavage Studies).

    PubMed

    1984-08-01

    Tris(2-ethylhexyl)phosphate is one of a family of triakyl phosphates that have been widely used as fire retardants and plasticizers. Another triakyl phosphate, tris(2,3-dibromopropyl)phosphate (Tris-BP), once used as a flame retardant in children's sleepwear, has been shown to be carcinogenic, but tris(2-ethylhexyl)phosphate has not been previously studied. Tris(2-ethylhexyl)phosphate, a clear, viscous liquid, is used as a component of vinyl stabilizers, grease additives, and flame-proofing compositions; however, it is used primarily as a plasticizer for vinyl plastic and synthetic rubber compounds. In 1974, approximately 3 million pounds of tris(2-ethylhexyl)phosphate was produced in the United States; imports during that year were negligible. Substantial human exposure probably occurs during production of tris(2-ethylhexyl)phosphate and during the manufacture and use of products containing it, but data on the magnitude of exposure are not available. Two-year toxicology and carcinogenesis studies of tris(2-ethylhexyl)phosphate were conducted by administering the test chemical in corn oil by gavage, 5 days per week for 103 weeks, to groups of 50 male and 50 female F344/N rats and B6C3F1 mice. Male rats received doses of 2,000 or 4,000 mg/kg body weight, female rats received 1,000 or 2,000 mg/kg, and male and female mice received 500 or 1,000 mg/kg. Fifty vehicle control animals of each sex and species received 10 ml/kg body weight (rats) or 3.3 ml/kg (mice) corn oil by gavage on the same schedule. Inflammation of the gastric mucosa in mice and mild weight depression in rats and mice were the only dose-related effects observed in the preliminary studies. In the 2-year studies, survival rates and mean body weight gains of dosed female rats and dosed mice were comparable to those of their perspective controls. Survival rates of dosed male rats were comparable to that of the vehicle controls, but body weight gains were depressed. One nonneoplastic lesion, follicular

  12. Central metal ion exchange in a coordination polymer based on lanthanide ions and di(2-ethylhexyl)phosphoric acid: exchange rate and tunable affinity.

    PubMed

    Tasaki-Handa, Yuiko; Abe, Yukie; Ooi, Kenta; Tanaka, Mikiya; Wakisaka, Akihiro

    2014-01-01

    In this paper the exchange of lanthanide(III) ions (Ln(3+)) between a solution and a coordination polymer (CP) of di(2-ethylhexyl)phosphoric acid (Hdehp), [Ln(dehp)3], is studied. Kinetic and selectivity studies suggest that a polymeric network of [Ln(dehp)3] has different characteristics than the corresponding monomeric complex. The reaction rate is remarkably slow and requires over 600 h to reach in nearly equilibrium, and this can be explained by the polymeric crystalline structure and high valency of Ln(3+). The affinity of the exchange reaction reaches a maximum with the Ln(3+) possessing an ionic radius 7% smaller than that of the central Ln(3+), therefore, the affinity of the [Ln(dehp)3] is tunable based on the choice of the central metal ion. Such unique affinity, which differs from the monomeric complex, can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The latter likely becomes predominant for Ln(3+) exchange when the ionic radius of the ion in solution is smaller than the original Ln(3+) by more than 7%. Structural studies suggest that the incoming Ln(3+) forms a new phase though an exchange reaction, and this could plausibly cause the structural strain. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Di(2-Ethylhexyl) Phthalate Exposure In Utero Damages Sertoli Cell Differentiation Via Disturbance of Sex Determination Pathway in Fetal and Postnatal Mice.

    PubMed

    Wang, Yongan; Yang, Qing; Liu, Wei; Yu, Mingxi; Zhang, Zhou; Cui, Xiaoyu

    2016-07-01

    Mice may share similar mechanism with human underlying reproductive toxicity induced by di(2-ethylhexyl) phthalate (DEHP), which is not supposed to be associated with decreased testicular testosterone. Pregnant mice were exposed to DEHP by gavage, with the dosage regime beginning at human relevant exposure level. After in utero DEHP exposure, loss of Sertoli cells and germ cells were observed in the male pups at postnatal days 21. And SRY-related HMG box 9 (SOX9), Fibroblast growth factor-9 (FGF9), and Double-sex and Mab-3 related transcripttion factor 1 (DMRT1) proteins were significantly downregulated by DEHP at 2 mg/kg/d and above, suggesting the depression of Sertoli cell differentiation. The repression of Sox9 genes expression was supported by whole-mount in situ hybridization and real-time real-time-quantitative PCR. The expressions of Cyp11α1 and Star were not significantly affected by in utero DEHP exposure, indicating the absence of effects on testosterone biosynthesis. Furthermore, the testosterone-independent pathway regulating Sertoli cells differentiation was disturbed in fetus by DEHP at 2 mg/kg/d and above during the critical time window of sex determination, involving Gadd45g → Gata4/Fog2 → Sry → Sox9 → Fgf9 The results suggest that in utero DEHP exposure damaged Sertoli cells in the postnatal life of mice offspring via disturbance of the differentiation regulating pathway, potentially inducing declines in spermatogenesis.

  14. Extractive spectrophotometric determination of palladium with N,N,N',N'-tetra(2-ethylhexyl)-thiodiglycolamide T(2EH)TDGA.

    PubMed

    Ruhela, R; Sharma, J N; B S Tomar; Hubli, R C; Suri, A K

    2011-08-15

    A precise, sensitive and selective method for the spectrophotometric determination of palladium (II) using N,N,N',N'-tetra(2-ethylhexyl) thiodiglycolamide T(2EH)TDGA as an extractant is described. Palladium (II) forms yellow colored complex with T(2EH)TDGA which exhibits an absorption maximum at ∼ 300 nm. The colored complex obeys Beer's law in the concentration range 1.0-15.0 μg ml(-1) of palladium with a molar absorptivity of 1.29 × 10(5)M(-1)cm(-1). The effects of various experimental parameters have been studied to establish the optimum conditions for the extraction and determination of palladium. The precision of the method has been evaluated and the relative standard deviation has been found to be less than 0.5%. The method has been successfully applied to the determination of palladium in simulated high level liquid waste (SHLW) solution. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Uptake of di(2-ethylhexyl) phthalate (DEHP) by the plant Benincasa hispida and its use for lowering DEHP content of intercropped vegetables.

    PubMed

    Wu, Zunyi; Zhang, Xiaolei; Wu, Xiaolian; Shen, Guoming; Du, Qizhen; Mo, Cehui

    2013-06-05

    Uptake of di(2-ethylhexyl) phthalate (DEHP) by the plant Benincasa hispida and its use for topical phytoremediation were investigated by cultivation of plants in DEHP-contaminated environments. The results showed that major plant organs of B. hispida , including leaves, stems, and fruits, readily absorbed DEHP from the air. The amount of DEHP that accumulated in leaves, stems, and fruits was mainly dependent upon exposure time, and most DEHP accumulated in their inner tissues. A single plant of B. hispida with a gourd was able to absorb more than 700 mg of DEHP when it was exposed to DEHP-contaminated air for 6 week. B. hispida reduced air DEHP concentration by 65-76% as the air DEHP concentration ranged from 2351 to 3955 μg/m³ (high DEHP level) and 85-92% as the air DEHP concentration ranged from 35.1 to 65.3 μg/m³ (low DEHP level) in greenhouse experiments. When intercropping of B. hispida and Brassica chinensis or Brassica campestris , B. hispida reduced more than 87% of DEHP accumulation in the latter, which indicates that B. hispida has excellent use potential for lowering the DEHP content of intercropped vegetables.

  16. The influence of humidity on the emission of di-(2-ethylhexyl) phthalate (DEHP) from vinyl flooring in the emission cell "FLEC"

    NASA Astrophysics Data System (ADS)

    Clausen, Per Axel; Xu, Ying; Kofoed-Sørensen, Vivi; Little, John C.; Wolkoff, Peder

    Asthma in children appears to be associated with both phthalate esters and dampness in buildings. An important question is whether the concentrations of phthalate esters correlate with dampness (expressed as relative humidity—RH) in indoor air. The objective was to study the influence of RH on the specific emission rate (SER) of di-(2-ethylhexyl)phthalate (DEHP) from one type of vinyl flooring in the well characterized Field and Laboratory Emission Cell (FLEC). The vinyl flooring with ca. 17% (w/w) DEHP as plasticizer was tested in 6 FLECs at 22 °C. The RH in the 6 FLECs was 10%, 30%, 50% (in triplicate) and 70%. The RH was changed after 248 d in 2 of the 50%-FLECs to 10% and 70%, and to 50% in the 10%-and 70%-FLECs. The data show that the SER of DEHP from vinyl flooring in FLECs during a 1 yr period is independent of the RH. A new physically based emission model for semivolatile organic compounds was found to be consistent with the experimental data and independent of the RH. The model helps to explain the RH results, because it appears that RH does not significantly influence any of the identified controlling mechanisms.

  17. Prenatal Exposures of Male Rats to the Environmental Chemicals Bisphenol A and Di(2-Ethylhexyl) Phthalate Impact the Sexual Differentiation Process.

    PubMed

    Abdel-Maksoud, Fatma M; Leasor, Khrystyna R; Butzen, Kate; Braden, Timothy D; Akingbemi, Benson T

    2015-12-01

    The increasing incidence of reproductive anomalies, described as testicular dysgenesis syndrome, is thought to be related to the exposure of the population to chemicals in the environment. Bisphenol A (BPA) and di(2-ethylhexyl)phthalate (DEHP), which have hormonal and antihormonal activity, have attracted public attention due to their presence in consumer products. The present study investigated the effects of BPA and DEHP on reproductive development. Timed-pregnant female rats were exposed to BPA and DEHP by gavage from gestational days 12 to 21. Results showed that prenatal exposures to test chemicals exerted variable effects on steroidogenic factor 1 and GATA binding protein 4 protein expression and increased (P < .05) sex-determining region Y-box 9 and antimüllerian hormone protein in the infantile rat testis compared with levels in the control unexposed animals. Pituitary LHβ and FSHβ subunit protein expression was increased (P < .05) in BPA- and DEHP-exposed prepubertal male rats but were decreased (P < .05) in adult animals relative to control. Exposure to both BPA and DEHP in utero inhibited (P < .05) global DNA hydroxymethylation in the adult testis in association with altered DNA methyltransferase protein expression. Together the present data suggest that altered developmental programming in the testes associated with chemical exposures are related to the disruption of sexual differentiation events and DNA methylation patterns. The chemical-induced effects impact the development of steroidogenic capacity in the adult testis.

  18. Concentration-dependent inhibition of development of GGT positive foci in rat liver by the environmental contaminant di(2-ethylhexyl) phthalate

    SciTech Connect

    DeAngelo, A.B.; Queral, A.E.; Garrett, C.T.

    1985-05-01

    The ability of di(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer and environmental contaminant, to suppress development of putative preneoplastic lesions in rat liver was evaluated. el-Glutamyl transpeptidase-positive (GGT+) foci were initiated in the livers of Sprague-Dawley male rats with a single dose of diethylnitrosamine (DEN) following partial hepatectomy. Promotion of foci was commenced by feeding a choline-deficient diet (CD). A group of control rats was fed a choline-supplemented diet (CS). The ability of DEHP to suppress the emergence of GGT+ foci was evaluated by feeding additional groups of rats the CD diet containing either 0.1%, 0.5%, 1.0% or 2.0% DEHP. The CD diet promoted the number of GGT+ foci above levels in control livers. Inclusion of the plasticizer to the levels of 0.5%, 1.0% and 2.0% in the CD diet effectively inhibited the appearance of the foci. However, DEHP was unable to inhibit the promoting effect of the CD diet at a concentration of 0.1%. DEHP's ability to block development of GGT+ foci correlated with its ability to increase liver weight and to induce carnitine acetyltransferase (EC 2.3.1.7), a marker of peroxisome proliferation.

  19. Epigallocatechin-3-O-Gallate Protects Against Hepatic Damage and Testicular Toxicity in Male Mice Exposed to Di-(2-Ethylhexyl) Phthalate.

    PubMed

    Ge, Jian; Han, Baoyu; Hu, Huajun; Liu, Jun; Liu, Yang

    2015-07-01

    The aim of this study was to examine the effects of epigallocatechin-3-O-gallate (EGCG) on hepatic damage and testicular toxicity in male mice exposed to daily oral administration of di-(2-ethylhexyl) phthalate (DEHP). A mouse model was used to assess the effects of daily intraperitoneal EGCG injection on hepatic and testicular damage. Histological and mitochondrial membrane potential results revealed that EGCG treatment significantly arrested the progression of hepatic damage. EGCG treatment resulted in significant suppression of liver injury (i.e., reduced activities of alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). The development of DEHP-induced hepatic and testicular damage altered the testosterone concentration in mouse serum, which could affect the reproductive ability of male mice. Moreover, EGCG treatment markedly attenuated testes lesions, sperm deformity, and spermatogenic cell apoptosis. At the molecular level, hepatic CYP3A4 expression was substantially reduced by EGCG treatment in mice exposed to DEHP compounds, whereas testicular aromatase expression was increased significantly in testes. Thus, these results demonstrate that EGCG administration may protect against liver damage and reproductive toxicity in males exposed to DEHP.

  20. Basic Characteristics of Bis(2-ethylhexyl)phosphate-impregnated Adsorbent Used for Separation of Minor Actinides from FBR-Spent Fuel

    NASA Astrophysics Data System (ADS)

    Oda, Ryohei; Arai, Tsuyoshi; Nagayama, Katsuhisa; Watanabe, Sou; Sano, Yuichi; Myouchin, Munetaka

    FBR-spent nuclear fuel includes a great deal of minor actinides (MA: Am and Cm), which become febrile. Radioactive wastes including MA require a large area of ground for dumping and result in high cost. In Fast Reactor Cycel System Technology Development Project (FaCT) in Japan, we have been investigating extraction chromatography for separation of long-lived MA and specific fission products (FP) from high-level liquid wastes (HLLW). This method is expected to allow us to reduce an organic solvent use and to realize compact equipment. In this work, we have studied the static and dynamic adsorption behavior of representative FP contained in HLLW, Mo(VI), Zr(IV), Nd(III) and EU(III), on a bis(2-ethylhexyl)phosphate (HDEHP)-impregnated adsorbent. Such fundamental data should facilitate the efficient design of efficient MA recovery processes. Column adsorption experiments with the HDEHP-impregnated adsorbent have revealed that an increase in a flow rate results in a short breakthrough time and reduces the adsorption capacity of the column for all the elements tested. These results strongly suggest that a lower flow rate is preferable to enhance the adsorption capacity of the adsorbent.

  1. Combining octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide and bis-(2-ethylhexyl)phosphoric acid extractants for recovering transuranic elements from irradiated nuclear fuel

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Gelis, Artem V.; Vandegrift, George F.

    2009-10-14

    Advanced concepts for closing the nuclear fuel cycle include separating Am and Cm from other fuel components. Separating these elements from the lanthanide elements at an industrial scale remains a significant technical challenge. We describe here a chemical system in which a neutral extractant--octyl(phenyl)-N,N-diisobutyl-carbamoylmethyl-phosphine oxide (CMPO)--is combined with an acidic extractant--bis-(2-ethylhexyl)phosphoric acid (HDEHP)--to form a single process solvent (with dodecane as the diluent) for separating Am and Cm from the other components of irradiated nuclear fuel. Continuous variation experiments in which the relative CMPO and HDEHP concentrations are varied indicate a synergistic relationship between the two extractants in the extraction of Am from buffered diethylenetriaminepentaacetic acid (DTPA) solutions. A solvent mixture consisting or 0.1 M CMPO + 1 M HDEHP in dodecane offers acceptable extraction efficiency for the trivalent lanthanides and actinides from 1 M HNO3 while maintaining good lanthanide/actinide separation factors in the stripping regime (buffered DTPA solutions with pH 3.5 to 4). Using citrate buffer instead of lactate buffer results in improved lanthanide/actinide separation factors.

  2. Thymic Stromal Lymphopoietin Neutralization Inhibits the Immune Adjuvant Effect of Di-(2-Ethylhexyl) Phthalate in Balb/c Mouse Asthma Model

    PubMed Central

    Wei, Chenxi; Chen, Shaohui; Mao, Lin; Zhang, Zhenye; Yang, Xu

    2016-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, has an adjuvant effect in combination with ovalbumin (OVA). The adjuvant effect of DEHP has already been verified in our previous studies. In this study, to further investigate whether thymic stromal lymphopoietin (TSLP) was involved in the DEHP-adjuvant effect, DEHP was administered through a daily gavage exposure route. Mice were sensitized with ovalbumin (OVA) to trigger allergic responses, and an anti-TSLP monoclonal antibody was used to neutralize the effect of TSLP. Biomarkers including cytokines in bronchoalveolar lavage fluid (BALF), serum total IgE and TSLP content in the lung were detected. In addition, airway hyperreactivity and lung sections were examined. Collectively, these data indicated a salient Th2 response which was characterized by the upregulation of Th2-type cytokines, such as interleukin 4 (IL-4), IL-5 and IL-13. Moreover, the eosinophil number in BALF and the eosinophil cationic protein (ECP) in the lung were seen to have increased significantly. However, neutralization of TSLP with an anti-TSLP mAb reversed the adjuvant effect of DEHP on airway inflammation, structural alterations in the airway wall and increased airway hyperresponsiveness (AHR) to methacholine induced by the OVA allergen, suggesting that TSLP was an effective target site for suppressing the adjuvant effect of DEHP co-exposure. PMID:27467143

  3. Chamber studies on mass-transfer of di(2-ethylhexyl)phthalate (DEHP) and di- n-butylphthalate (DnBP) from emission sources into house dust

    NASA Astrophysics Data System (ADS)

    Schripp, Tobias; Fauck, Christian; Salthammer, Tunga

    2010-08-01

    For a number of phthalates and especially for di(2-ethylhexyl)phthalate (DEHP), surprisingly high house dust concentrations are reported in the literature. Therefore, the uptake of the most prominent compounds DEHP and di- n-butylphthalate (DnBP) from plasticized indoor materials into house dust samples of different organic content has been experimentally determined. The experiments have been performed within 45 days which is sufficient for the more volatile phthalate (DnBP) to reach equilibrium conditions. DnBP reaches considerably higher concentrations in the chamber air compared to real room measurements and, thus, also elevated dust concentrations. In contrast, the mass transfer of DEHP in the dust via the gas phase was significantly lower. However, small chamber experiments showed elevated mass transfer of DEHP in case of direct contact between emission source and sink. This aspect is experimentally determined using an plasticized PVC polymer with and without direct contact to house dust. A transfer into the dust could be observed in dependence of the initial concentration in the material. However, the results do not allow the differentiation between the two uptake mechanisms via capillary forces and contact to the material's boundary layer. The results illustrate that the reasons for elevated DEHP concentrations in dust indoors can be traced back to direct contact of source and sink, abrasion from the source, and transport via airborne particles.

  4. Di-(2-ethylhexyl) phthalate exposure is negatively correlated with trait anxiety in girls but not with trait anxiety in boys or anxiety-like behavior in male mice.

    PubMed

    Park, Subin; Cheong, Jae Hoon; Cho, Soo-Churl; Kim, Jae-Won; Shin, Min-Sup; Yoo, Hee Jeong; Han, Doug Hyun; Kim, Bung-Nyun

    2015-01-01

    The authors aimed to study the effects of postnatal exposure to phthalate on anxiety-like behavior in mice and anxiety proneness in children. Male Imprinting Control Region (ICR) mice aged 4 weeks were administered 20 to 540 mg/kg of di-(2-ethylhexyl) phthalate (DEHP) or vehicle and assessed in the Open Field Test. A group of 277 children aged 8-11 years (150 males) was recruited from South Korea. A cross-sectional examination of urinary DEHP and dibutylphthalate metabolite concentrations was conducted, and the children were scored on the Trait Anxiety Inventory for Children (TAIC). DEHP metabolite concentrations in the urine were significantly and negatively correlated with TAIC scores in the female population but not in the male population. There were no significant group differences in the percentage of distance moved or time spent in the central area in male mice treated with DEHP or vehicle. Our results suggest a sex-dependent effect of DEHP on anxiety proneness in childhood.

  5. Cytotoxic Activity of Bioactive Compound 1, 2- Benzene Dicarboxylic Acid, Mono 2- Ethylhexyl Ester Extracted from a Marine Derived Streptomyces sp. VITSJK8

    PubMed Central

    Krishnan, Kannabiran; Mani, Abirami; Jasmine, Subashini

    2014-01-01

    Marine Streptomyces are prolific producers of majority of bioactive secondary metabolites which are used in pharmaceutical industry as effective drugs against life threatening diseases. The cytotoxic activity of the pure compound 1, 2- benzene dicarboxylic acid, mono 2- ethylhexyl ester (DMEHE) from marine derived actinomycete Streptomyces sp. VITSJK8 was investigated against mouse embryonic fibroblast (NIH 3T3) and human keratinocyte (HaCaT) normal cell lines, human hepatocellular liver carcinoma (HepG 2) and human breast adenocarcinoma (MCF-7) cell lines by using MTT assay. The compound DMEHE exhibited IC 50 values of 42, 100, 250 and 500 µg/ ml against HepG2, MCF-7, HaCaT and NIH 3T3 cell lines, respectively. The effect of DMEHE on the growth of cancer cell lines was expressed as the % of viability. Cell viability was recorded as 67.7%, 78.14%, 82.23% and 96. 11% in HepG2, MCF-7, HaCaT and NIH 3T3 cells, respectively. The results of the study conclude that the bioactive compound isolated from the potential isolate Streptomyces sp. VITSJK8 exhibited cytotoxic activity against HepG2 and MCF- 7 cancer cell lines and low toxicity against normal HaCaT and NIH 3T3 cell lines. PMID:25635251

  6. Reduced Hippocampal Dendritic Spine Density and BDNF Expression following Acute Postnatal Exposure to Di(2-Ethylhexyl) Phthalate in Male Long Evans Rats

    PubMed Central

    Smith, Catherine A.; Holahan, Matthew R.

    2014-01-01

    Early developmental exposure to di(2-ethylhexyl) phthalate (DEHP) has been linked to a variety of neurodevelopmental changes, particularly in rodents. The primary goal of this work was to establish whether acute postnatal exposure to a low dose of DEHP would alter hippocampal dendritic morphology and BDNF and caspase-3 mRNA expression in male and female Long Evans rats. Treatment with DEHP in male rats led to a reduction in spine density on basal and apical dendrites of neurons in the CA3 dorsal hippocampal region compared to vehicle-treated male controls. Dorsal hippocampal BDNF mRNA expression was also down-regulated in male rats exposed to DEHP. No differences in hippocampal spine density or BDNF mRNA expression were observed in female rats treated with DEHP compared to controls. DEHP treatment did not affect hippocampal caspase-3 mRNA expression in male or female rats. These results suggest a gender-specific vulnerability to early developmental DEHP exposure in male rats whereby postnatal DEHP exposure may interfere with normal synaptogenesis and connectivity in the hippocampus. Decreased expression of BDNF mRNA may represent a molecular mechanism underlying the reduction in dendritic spine density observed in hippocampal CA3 neurons. These findings provide initial evidence for a link between developmental exposure to DEHP, reduced levels of BDNF and hippocampal atrophy in male rats. PMID:25295592

  7. Optimized extraction method for LC-MS determination of bisphenol A, melamine and di(2-ethylhexyl) phthalate in selected soft drinks, syringes, and milk powder.

    PubMed

    Khedr, Alaa

    2013-07-01

    Described below is an optimized solid-phase extraction method (SPE) for the simultaneous determination of three hazardous plastic additives. Two high-performance liquid chromatographic-electrospray ionization-mass spectrometric (HPLC-ESI-MS) methods were developed and validated to estimate the melamine (MEL), bis(2-ethylhexyl) phthalate (DEHP), and bisphenol A (BPA) contents in drinking water, syringes, soft drinks, and dry milk powder. One extraction procedure optimally recovered all three substances from the different matrices. Two extraction columns were combined and included a silica gel LiChroprep RP-2 column (20:1, g/g, top column) and a Sep-Pak with a C18 column (500mg, bottom column). The analytical column was an Agilent Eclipse XDB-C8 column, 4.6mm×150mm, 5μm, maintained at 50±2°C. MEL and DEHP were monitored by positive triple quad mass spectrometry (TQ-MS) using an acidic mobile phase, while BPA was monitored by negative TQ-MS using a mobile phase containing a 0.05% ammonia solution. The general linear range of the three compounds ranged from 12 to 1000pg/μL in the injected solution (25μL). The average extraction recoveries were within the range of 83.0-102.5%. Relatively high concentrations of BPA and DEHP were found in the milk powder and sterile syringes.

  8. Mono-2-ethylhexyl phthalate induced loss of mitochondrial membrane potential and activation of Caspase3 in HepG2 cells.

    PubMed

    Chen, Xi; Wang, Jianshu; Qin, Qizhi; Jiang, Ying; Yang, Guangtao; Rao, Kaimin; Wang, Qian; Xiong, Wei; Yuan, Jing

    2012-05-01

    L02 and HepG2 cells were exposed to mono-(2-ethylhexyl) phthalate (MEHP) at concentrations of 6.25-100μM. After 48h treatment, MEHP decreased HepG2 cell viability in a concentration-dependent manner and L02 cell viability in the 50 and 100μM groups (p<0.01). Furthermore, at 24 and 48h after treatment, MEHP decreased the glutathione levels of HepG2 cells in all treatment groups and in the ΔΨ(m) in L02 and HepG2 cells with MEHP≥25μM (p<0.05 or p<0.01). At 24h after treatment, MEHP induced activation of caspase3 in all treated HepG2 and L02 cells (p<0.05 or p<0.01) except the 100μM MEHP treatment group. The increase in the Bax to Bcl-2 ratio suggests that Bcl-2 family involved in the control of MEHP-induced apoptosis in these two cell types. The data suggest that MEHP could induce apoptosis of HepG2 cells through mitochondria- and caspase3-dependent pathways.

  9. Fast preconcentration of trace rare earth elements from environmental samples by di(2-ethylhexyl)phosphoric acid grafted magnetic nanoparticles followed by inductively coupled plasma mass spectrometry detection

    NASA Astrophysics Data System (ADS)

    Yan, Ping; He, Man; Chen, Beibei; Hu, Bin

    2017-10-01

    In this work, di(2-ethylhexyl)phosphoric acid (P204) grafted magnetic nanoparticles were synthesized by fabricating P204 onto Fe3O4@TiO2 nanoparticles based on Lewis acid-base interaction between Ti and phosphate group under weakly acidic condition. The prepared Fe3O4@TiO2@P204 nanoparticles exhibited excellent selectivity for rare earth elements, and good anti-interference ability. Based on it, a method of magnetic solid phase extraction (MSPE) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for fast preconcentration and determination of trace rare earth elements in environmental samples. Under the optimal conditions, the detection limits of rare earth elements were in the range of 0.01 (Tm)-0.12 (Nd) ng L- 1 with an enrichment factor of 100-fold, and the relative standard deviations ranged from 4.9 (Pr) to 10.7% (Er). The proposed method was successfully applied to the determination of rare earth elements in environmental samples, including river water, lake water, seawater and sediment.

  10. Different effects by sex on hypothalamic-pituitary axis of prepubertal offspring rats produced by in utero and lactational exposure to di-(2-ethylhexyl) phthalate (DEHP).

    PubMed

    Carbone, S; Samaniego, Y A; Cutrera, R; Reynoso, R; Cardoso, N; Scacchi, P; Moguilevsky, J A; Ponzo, O J

    2012-01-01

    This study investigated the effect of pre and perinatal exposure to di-(2-ethylhexyl) phthalate (DEHP) on the neuroendocrine parameters that regulate reproduction in prepubertal male and female rats. DEHP at doses of 3 and 30mg/kgbw/day was administered orally in the drinking water to dam rats since pregnancy onset until the moment of pups sacrifice at 15 days of age. In these animals gonadotropin serum level and the hypothalamic contents of the amino acids aspartate, glutamate and gamma-aminobutyric acid were determined. No changes in gonadotropin levels and amino acid neurotransmitters were detected at the low dose in both sexes. However, DEHP administered at high dose (30mg/kgbw/day) to dams produced a significant decrease in the inhibitory neurotransmitter GABA and an increase in the stimulatory neurotransmitter aspartate in prepubertal male offspring rats. These modifications were accompanied by gonadotropin serum levels increase. On the contrary, in treated female rats this chemical increased both, aspartate and GABA, which exert a characteristic stimulatory action on gonadotropin in 15-day-old normal females. This study provides new data about changes produced by DEHP on the hypothalamic amino acid neurotransmitters involved in the neuroendocrine reproductive regulation, in prepubertal male and female rat offspring from dams exposed during gestational and lactational periods. These alterations induced by DEHP exposure could be related to the gonadotropin modifications also described in this work, and with changes in the production of sexual hormones previously reported by other authors. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Cytotoxic Activity of Bioactive Compound 1, 2- Benzene Dicarboxylic Acid, Mono 2- Ethylhexyl Ester Extracted from a Marine Derived Streptomyces sp. VITSJK8.

    PubMed

    Krishnan, Kannabiran; Mani, Abirami; Jasmine, Subashini

    2014-01-01

    Marine Streptomyces are prolific producers of majority of bioactive secondary metabolites which are used in pharmaceutical industry as effective drugs against life threatening diseases. The cytotoxic activity of the pure compound 1, 2- benzene dicarboxylic acid, mono 2- ethylhexyl ester (DMEHE) from marine derived actinomycete Streptomyces sp. VITSJK8 was investigated against mouse embryonic fibroblast (NIH 3T3) and human keratinocyte (HaCaT) normal cell lines, human hepatocellular liver carcinoma (HepG 2) and human breast adenocarcinoma (MCF-7) cell lines by using MTT assay. The compound DMEHE exhibited IC 50 values of 42, 100, 250 and 500 µg/ ml against HepG2, MCF-7, HaCaT and NIH 3T3 cell lines, respectively. The effect of DMEHE on the growth of cancer cell lines was expressed as the % of viability. Cell viability was recorded as 67.7%, 78.14%, 82.23% and 96. 11% in HepG2, MCF-7, HaCaT and NIH 3T3 cells, respectively. The results of the study conclude that the bioactive compound isolated from the potential isolate Streptomyces sp. VITSJK8 exhibited cytotoxic activity against HepG2 and MCF- 7 cancer cell lines and low toxicity against normal HaCaT and NIH 3T3 cell lines.

  12. Synergistic extraction equilibrium of gallium(III) with di(2-ethylhexyl)phosphoric acid and 8-quinolinol derivatives into supercritical carbon dioxide.

    PubMed

    Ohashi, Akira; Kawashima, Natsumi; Sato, Kazuaki; Kim, Haeng-Boo

    2013-01-01

    The synergistic effect of five 8-quinolinol derivatives (HQs) on the extraction of gallium(III) with di(2-ethylhexyl)-phosphoric acid (D2EHPA or HA) from weak nitric acid into supercritical carbon dioxide (SC-CO(2)) was investigated. 8-Quinolinol (Hq), 5-ethoxymethyl-8-quinolinol (HO(2)q), 5-hexyloxymethyl-8-quinolinol (HO(6)q), 5-(2,2,2-trifluoroethoxymethyl)-8-quinolinol (HFO(2)q), and 5-chloro-8-quinolinol (5-Cl-Hq) were used as synergists. Synergism was observed for all of the HQs. The synergistic effect increased in the following order: Hq < HO(2)q < HFO(2)q < 5-Cl-Hq ≍ HO(6)q. The extent of synergism can be related to both the distribution constant and the acid dissociation constant of the HQ. The synergistic extraction equilibrium of gallium(III) with D2EHPA and 5-Cl-Hq into SC-CO(2) was investigated; the results suggest that the composition of the extracted complex is as GaA(2)Q·HA. The synergistic extraction mechanism was the same for both SC-CO(2) and n-heptane. The synergistic extraction equilibrium constants in both cases were calculated based on the experimental results.

  13. Di(2-ethylhexyl)phthalate leached from medical PVC devices serves as a substrate and inhibitor for the P-glycoprotein.

    PubMed

    Kim, Joon-Ho; Yun, Jisoo; Sohng, Jae-Kyung; Cha, Jin-Myeong; Choi, Bum-Chae; Jeon, Ho-Jong; Kim, Sang-Hyun; Choi, Cheol-Hee

    2007-05-01

    A di(2-ethylhexyl)phthalate (DEHP) was accidentally extracted from plastics in the process of purification of chemosensitizers reversing P-glycoprotein (Pgp)-mediated multidrug resistance (MDR). The purpose of this study was to investigate the Pgp-reversal activities of phthalates, which are endocrine-disrupting chemicals, by utilizing the Pgp-overexpressing leukemic cell line AML-2/D100. The phthalates includes DEHP, diethyl phthalate (DEP) and dibutyl phthalate (DBP). Of the tested phthalates, DEHP showed the highest Pgp-reversal activity and DEP the most potent drug-accumulating activity. On the other hand, they did not show any chemosensitizing activity against multidrug resistance associated protein-mediated MDR. The complete inhibition of Pgp by verapamil increased the cytotoxicity of DEHP, but neither DEP nor DBP had this effect, suggesting that DEHP alone may be a possible substrate for the Pgp. DEHP showed higher hydrophobicity than the other phthalates when determined by reverse phase-HPLC. In addition, DEHP, but not the others increased the ATPase activity in a concentration-dependent manner. This is the first report that phthalates can reverse Pgp-mediated MDR by increasing drug accumulation, as well as serving as substrates for the Pgp. It is thought that the hydrophobic characteristics of phthalates could play an important role in Pgp-inhibitory activity. Therefore, pharmaco- and toxicokinetic interactions between phthalates leached from medical PVC devices and substrates for the Pgp should be kept in mind. Copyright © 2006 Elsevier B.V. All rights reserved.

  14. Di-(2-Ethylhexyl) Phthalate Metabolites in Urine Show Age-Related Changes and Associations with Adiposity and Parameters of Insulin Sensitivity in Childhood

    PubMed Central

    Smerieri, Arianna; Testa, Chiara; Lazzeroni, Pietro; Nuti, Francesca; Grossi, Enzo; Cesari, Silvia; Montanini, Luisa; Latini, Giuseppe; Bernasconi, Sergio; Papini, Anna Maria; Street, Maria E.

    2015-01-01

    Objectives Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl) phthalate (DEHP) in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity. Design and Methods DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP), were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables. Results The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity. Conclusion It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects. PMID:25706863

  15. Interplay of Noncovalent Interactions in Ionic Liquid/Sodium Bis(2-ethylhexyl) Sulfosuccinate Mixtures: From Lamellar to Bicontinuous Cubic Liquid Crystalline Phase.

    PubMed

    Novak, Sanja; Morasi Piperčić, Sara; Makarić, Sandro; Primožič, Ines; Ćurlin, Marija; Štefanić, Zoran; Domazet Jurašin, Darija

    2016-12-15

    Phase transitions in mixtures of imidazolium based ionic liquid ([C12mim]Br) and anionic double tail surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT), were studied using a multitechnique approach. The system was primarily chosen for its expected ability to form a variety of lamellar and nonlamellar liquid crystalline phases which can transform into each other via different mechanisms. Depending on the bulk composition and total surfactant concentration, mixed micelles, coacervates, and lamellar and inverse bicontinuous cubic liquid crystalline phase were observed. Along with electrostatic attractions and geometric packing constraints, additional noncovalent interactions (hydrogen bonding, π-π stacking) enhanced attractive interactions and stabilized low curvature aggregates. At stoichiometric conditions, coexistence of coacervates and vesicles was found at lower, while bicontinuous cubic phase and vesicles were present at higher total surfactant concentrations. The phase transitions from a dispersed lamellar to inverse cubic bicontinuous phase occur as a consequence of charge shielding and closer packing of oppositely charged headgroups followed by a change in bilayer curvature. Transition is continuous with both phases coexisting over a relatively broad range of concentrations and very likely involves a sponge-like phase as a structural intermediate. To the best of our knowledge, this type of phase transition has not been observed before in surface active ionic liquid/surfactant mixtures.

  16. Reduced hippocampal dendritic spine density and BDNF expression following acute postnatal exposure to di(2-ethylhexyl) phthalate in male Long Evans rats.

    PubMed

    Smith, Catherine A; Holahan, Matthew R

    2014-01-01

    Early developmental exposure to di(2-ethylhexyl) phthalate (DEHP) has been linked to a variety of neurodevelopmental changes, particularly in rodents. The primary goal of this work was to establish whether acute postnatal exposure to a low dose of DEHP would alter hippocampal dendritic morphology and BDNF and caspase-3 mRNA expression in male and female Long Evans rats. Treatment with DEHP in male rats led to a reduction in spine density on basal and apical dendrites of neurons in the CA3 dorsal hippocampal region compared to vehicle-treated male controls. Dorsal hippocampal BDNF mRNA expression was also down-regulated in male rats exposed to DEHP. No differences in hippocampal spine density or BDNF mRNA expression were observed in female rats treated with DEHP compared to controls. DEHP treatment did not affect hippocampal caspase-3 mRNA expression in male or female rats. These results suggest a gender-specific vulnerability to early developmental DEHP exposure in male rats whereby postnatal DEHP exposure may interfere with normal synaptogenesis and connectivity in the hippocampus. Decreased expression of BDNF mRNA may represent a molecular mechanism underlying the reduction in dendritic spine density observed in hippocampal CA3 neurons. These findings provide initial evidence for a link between developmental exposure to DEHP, reduced levels of BDNF and hippocampal atrophy in male rats.

  17. Extraction Equilibrium of Mn2+, Ca2+, and Mg2+ from Chloride Solutions by Di(2-ethylhexyl)phosphoric Acid Dissolved in Kerosene

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanfu; Cao, Wenxin; Zhan, Jing; Ding, Fenghua; Hwang, Jiann-Yang

    2015-05-01

    The presence of calcium and magnesium affects the purity of the final product MnCl2 in hydrometallurgical treatment processes. The solvent extraction method can be used to separate Ca2+ and Mg2+ from Mn2+ solutions containing impurity ions such as Ca2+ and Mg2+. This article aims to investigate the single-stage extraction equilibrium of Ca2+, Mg2+, and Mn2+ in chloride medium using di(2-ethylhexyl)phosphoric acid in kerosene (O:A = 1:1). The results show that the pH0.5 values are 1.11, 1.56, and 2.18 for Ca2+, Mn2+, and Mg2+, respectively. The mechanism of extraction and stoichiometries of metal-containing extracted species were illustrated based on a slope analysis. The composition of the extracted species in the organic phase is proposed to be MnR2·R2H2, CaR2·R2H2, and MgR2·(R2H2)2, respectively.

  18. Acrylic AB and ABA block copolymers based on poly(2-ethylhexyl acrylate) (PEHA) and poly(methyl methacrylate) (PMMA) via ATRP.

    PubMed

    Haloi, Dhruba J; Ata, Souvik; Singha, Nikhil K; Jehnichen, Dieter; Voit, Brigitte

    2012-08-01

    Acrylic block copolymers have several advantages over conventional styrenic block copolymers, because of the presence of a saturated backbone and polar pendant groups. This investigation reports the preparation and characterization of di- and triblock copolymers (AB and ABA types) of 2-ethylhexyl acrylate (EHA) and methyl methacrylate (MMA) via atom transfer radical polymerization (ATRP). A series of block copolymers, PEHA-block-PMMA(AB diblock) and PMMA-block-PEHA-block-PMMA(ABA triblock) were prepared via ATRP at 90 °C using CuBr as catalyst in combination with N,N,N',N″,N″-pentamethyl diethylenetriamine (PMDETA) as ligand and acetone as additive. The chemical structure of the macroinitiators and molar composition of block copolymers were characterized by (1)H NMR analysis, and molecular weights of the polymers were analyzed by GPC analysis. DSC analysis showed two glass transition temperatures (T(g)), indicating formation of two domains, which was corroborated by AFM analysis. Small-angle X-ray scattering (SAXS) analysis of AB and ABA block copolymers showed scattering behavior inside the measuring limits indicating nanophase separation. However, SAXS pattern of AB diblock copolymers indicated general phase separation only, whereas for ABA triblock copolymer an ordered or mixed morphology could be deduced, which is assumed to be the reason for the better mechanical properties achieved with ABA block copolymers than with the AB analogues.

  19. Rates of dissolution and biodegradation of water-insoluble organic compounds.

    PubMed Central

    Thomas, J M; Yordy, J R; Amador, J A; Alexander, M

    1986-01-01

    We conducted a study of the relationship between the dissolution rates of organic compounds that are sparingly soluble in water and the biodegradation of these compounds by mixed cultures of bacteria. The rates of dissolution of naphthalene and 4-chlorobiphenyl were directly related to their surface areas. The bacteria caused a decline in the concentration of the soluble substrate. The rate of bacterial growth fell abruptly when 4-chlorobiphenyl or naphthalene was no longer detectable in solution. The population continued to increase in media with different surface areas of insoluble 4-chlorobiphenyl, but the final counts were higher in media in which the surface areas of the substrate were larger. The rates of dissolution of palmitic acid, octadecane, di(2-ethylhexyl) phthalate, and 1-naphthyl N-methylcarbamate were determined in the absence of microorganisms. A mixed culture of microorganisms mineralized palmitic acid, di(2-ethylhexyl) phthalate, and Sevin (1-naphthyl N-methylcarbamate) at a logarithmic rate, but octadecane mineralization was linear. The rates of mineralization at the end of the active phase of the biodegradation were lower than the rate of dissolution of palmitic acid but higher than the rate of dissolution of octadecane in the uninoculated medium. We suggest that spontaneous dissolution rates are only one of the factors that govern the rates of biodegradation. PMID:3092736

  20. Lanthanide ion exchange properties of a coordination polymer consisting of di(2-ethylhexyl) phosphoric acid and trivalent metal ions (Ce3+, Fe3+, or Al3+).

    PubMed

    Ooi, Kenta; Tasaki-Handa, Yuiko; Abe, Yukie; Wakisaka, Akihiko

    2014-03-28

    Three kinds of coordination polymers ([M(dehp)3], M = Ce, Fe, or Al) were prepared by mixing the sodium form (Na(dehp)) of di(2-ethylhexyl) phosphoric acid and MCl3 in an ethanol-water binary mixture. They have monoclinic crystalline structure with similar lattice parameters. The lanthanide ion (Ln(3+) = La(3+), Sm(3+), Dy(3+), or Yb(3+)) exchange properties were studied in a 20 : 80 vol% ethanol-water binary mixture containing 2 mM Ln(NO3)3 at room temperature. The rate of Ln(3+) adsorption is relatively slow; it requires over 3 weeks to reach equilibrium. [M(dehp)3] has different Ln(3+) affinities depending on the kind of central metal ions: the affinity order at 3 week adsorption is Yb(3+) < La(3+) < Dy(3+) < Sm(3+) for [Ce(dehp)3], La(3+) < Sm(3+) < Dy(3+) < Yb(3+) for [Fe(dehp)3], and La(3+) < Sm(3+), Dy(3+), Yb(3+) for [Al(dehp)3]. The difference in affinity order can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The chemical and structural analyses suggested that the Ln(3+) adsorption progresses first by the central M(3+)/Ln(3+) exchange, followed by a morphological change to a rod-like or fibrous form by a solid phase reaction. In the case of [Fe(dehp)3], the eluted Fe(3+) may be hydrolyzed and precipitated as amorphous iron hydroxide.

  1. Increased urinary 8-hydroxy-2'-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China.

    PubMed

    Wang, Qian; Wang, Li; Chen, Xi; Rao, Kai Min; Lu, Shao You; Ma, Sheng Tao; Jiang, Pu; Zheng, Dan; Xu, Shun Qing; Zheng, Hong Yan; Wang, Jian Shu; Yu, Zhi Qiang; Zhang, Rong; Tao, Yong; Yuan, Jing

    2011-07-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited. The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender-age matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed. Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 μg/l; well water: 14.20 vs. 0.79 μg/l, pond water: 135.68 vs. 0.37 μg/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p < 0.05 for all). The workers had higher median levels of MDA (3.80 vs. 3.14 nmol/ml) and urinary 8-OHdG (340.37 vs. 268.18 μmol/mol creatinine) and decreased SOD activities (112.15 vs. 123.82 U/ml) than the reference group (p < 0.01 for all). Multivariate analysis revealed that the history of working in waste plastic recycling was an independent risk factor for the increased urinary 8-OHdG levels in the male workers (p < 0.01). The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.

  2. Rape (Brassica chinensis L.) seed germination, seedling growth, and physiology in soil polluted with di-n-butyl phthalate and bis(2-ethylhexyl) phthalate.

    PubMed

    Ma, Tingting; Christie, Peter; Teng, Ying; Luo, Yongming

    2013-08-01

    Phthalic acid esters (PAEs) pollution in agricultural soils caused by widely employed plastic products is becoming more and more widespread in China. PAEs polluted soil can lead to phytotoxicity in higher plants and potential health risks to human being. We evaluated the individual toxicity of di-n-butyl phthalate (DnBP) and bis(2-ethylhexyl) phthalate (DEHP), two representative PAEs, to sown rape (Brassica chinensis L.) seeds within 72 h (as germination stage) and seedlings after germination for 14 days by monitoring responses and trends of different biological parameters. No significant effects of six concentrations of PAE ranging from 0 (not treated/NT) to 500 mg kg(-1) on germination rate in soil were observed. However, root length, shoot length, and biomass (fresh weight) were inhibited by both pollutants (except root length and biomass under DEHP). Stimulatory effects of both target pollutants on malondialdehyde (MDA) content, superoxide dismutase (SODase) activity, ascorbate peroxidase (APXase) content, and polyphenoloxidase (PPOase) activity in shoots and roots (SODase activity in shoots excluded) were in the same trend with the promotion of proline (Pro) but differed with acetylcholinesterase activity (except in shoots under DnBP) for analyzed samples treated for 72 h and 14 days. Responses of representative storage compounds free amino acids (FAA) and total soluble sugar (TSS) under both PAEs were raised. Sensitivity of APXase and Pro in roots demonstrates their possibility in estimation of PAE phytotoxicity and the higher toxicity of DnBP, which has also been approved by the morphological photos of seedlings at day 14. Higher sensitivity of the roots was also observed. The recommended soil allowable concentration is 5 mg DnBP kg(-1) soil for the development of rape. We still need to know the phytotoxicity of DEHP at whole seedling stage for both the growing and development; on the other hand, soil criteria for PAE compounds are urgently required in

  3. Effects of di-n-butyl phthalate and di (2-ethylhexyl) phthalate on the growth, photosynthesis, and chlorophyll fluorescence of wheat seedlings.

    PubMed

    Gao, Minling; Qi, Yun; Song, Wenhua; Xu, Haoran

    2016-05-01

    Phthalates are commonly used man-made chemicals that can be released into soil, water, and the atmosphere. The potential toxicity of phthalates on wheat seedlings has not been well studied. To better understand the deleterious effects of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on wheat seedlings, their influences on the following were investigated: plant growth, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci), chlorophyll content, initial fluorescence (F0), maximal photochemical efficiency (Fv/Fm), photochemical quenching (qP), non-photochemical quenching (qN), effective quantum yield of photosystem II (ΦPSII), and photosynthetic electron transport rate (ETR). Compared with the control, the growth indices (plant height, fresh and dry weights of shoots, fresh and dry weights of roots), Pn, Gs, Tr, Ci, chlorophyll content, Fv/Fm, qP, ΦPSII, and ETR decreased in the 5 μg mL(-1) and 10 μg mL(-1) DBP and DEHP treatments, whereas F0 and qN increased. When wheat seedlings were treated with 20 μg mL(-1) of DBP and DEHP, the growth indices, Pn, Gs, Tr, chlorophyll content, Fv/Fm, qP, qN, ΦPSII, and ETR decreased significantly, whereas Ci and F0 increased. A decrease in the Pn of wheat seedlings was mainly caused by stomatal limitation in the 5 μg mL(-1) and 10 μg mL(-1) DBP and DEHP treatments. However, stomatal and non-stomatal limitations may have caused the reduction in Pn in the 20 μg mL(-1) DBP and DEHP treatments. Notably, the noxious effect of DBP on the wheat seedlings was significantly greater than that of DEHP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The effects of Di-(2-ethylhexyl)-phthalate exposure on fertilization and embryonic development in vitro and testicular genomic mutation in vivo.

    PubMed

    Huang, Xue-Feng; Li, Yan; Gu, Yi-Hua; Liu, Miao; Xu, Yan; Yuan, Yao; Sun, Fei; Zhang, Hui-Qin; Shi, Hui-Juan

    2012-01-01

    The present study was undertaken to determine the reproductive hazards of Di-(2-ethylhexyl)-phthalate (DEHP) on mouse spermatozoa and embryos in vitro and genomic changes in vivo. Direct low-level DEHP exposure (1 μg/ml) on spermatozoa and embryos was investigated by in vitro fertilization (IVF) process, culture of preimplanted embryos in DEHP-supplemented medium and embryo transfer to achieve full term development. Big Blue® transgenic mouse model was employed to evaluate the mutagenesis of testicular genome with in vivo exposure concentration of DEHP (500 mg/kg/day). Generally, DEHP-treated spermatozoa (1 μg/ml, 30 min) presented reduced fertilization ability (P<0.05) and the resultant embryos had decreased developmental potential compared to DMSO controls (P<0.05). Meanwhile, the transferred 2-cell stage embryos derived from treated spermatozoa also exhibited decreased birth rate than that of control (P<0.05). When fertilized oocytes or 2-cell stage embryos were recovered by in vivo fertilization (without treatment) and then exposed to DEHP, the subsequent development proceed to blastocysts was different, fertilized oocytes were significantly affected (P<0.05) whereas developmental progression of 2-cell stage embryos was similar to controls (P>0.05). Testes of the Big Blue® transgenic mice treated with DEHP for 4 weeks indicated an approximately 3-fold increase in genomic DNA mutation frequency compared with controls (P<0.05). These findings unveiled the hazardous effects of direct low-level exposure of DEHP on spermatozoa's fertilization ability as well as embryonic development, and proved that in vivo DEHP exposure posed mutagenic risks in the reproductive organ - at least in testes, are of great concern to human male reproductive health.

  5. Mono-(2-ethylhexyl) Phthalate Directly Alters the Expression of Leydig Cell Genes and CYP17 Lyase Activity in Cultured Rat Fetal Testis

    PubMed Central

    Chauvigné, François; Plummer, Simon; Lesné, Laurianne; Cravedi, Jean-Pierre; Dejucq-Rainsford, Nathalie; Fostier, Alexis; Jégou, Bernard

    2011-01-01

    Exposure to phthalates in utero alters fetal rat testis gene expression and testosterone production, but much remains to be done to understand the mechanisms underlying the direct action of phthalate within the fetal testis. We aimed to investigate the direct mechanisms of action of mono-(2-ethylhexyl) phthalate (MEHP) on the rat fetal testis, focusing on Leydig cell steroidogenesis in particular. We used an in vitro system based on the culture for three days, with or without MEHP, of rat fetal testes obtained at 14.5 days post-coitum. Exposure to MEHP led to a dose-dependent decrease in testosterone production. Moreover, the production of 5 alpha-dihydrotestosterone (5α-DHT) (−68%) and androstenedione (−54%) was also inhibited by 10 µM MEHP, whereas 17 alpha-hydroxyprogesterone (17α-OHP) production was found to increase (+41%). Testosterone synthesis was rescued by the addition of androstenedione but not by any of the other precursors used. Thus, the hormone data suggested that steroidogenesis was blocked at the level of the 17,20 lyase activity of the P450c17 enzyme (CYP17), converting 17α-OHP to androstenedione. The subsequent gene expression and protein levels supported this hypothesis. In addition to Cyp17a1, microarray analysis showed that several other genes important for testes development were affected by MEHP. These genes included those encoding insulin-like factor 3 (INSL3), which is involved in controlling testicular descent, and Inha, which encodes the alpha subunit of inhibin B. These findings indicate that under in vitro conditions known to support normal differentiation of the fetal rat testis, the exposure to MEHP directly inhibits several important Leydig cell factors involved in testis function and that the Cyp17a1 gene is a specific target to MEHP explaining the MEHP-induced suppression of steroidogenesis observed. PMID:22087261

  6. Mono-(2-ethylhexyl) phthalate directly alters the expression of Leydig cell genes and CYP17 lyase activity in cultured rat fetal testis.

    PubMed

    Chauvigné, François; Plummer, Simon; Lesné, Laurianne; Cravedi, Jean-Pierre; Dejucq-Rainsford, Nathalie; Fostier, Alexis; Jégou, Bernard

    2011-01-01

    Exposure to phthalates in utero alters fetal rat testis gene expression and testosterone production, but much remains to be done to understand the mechanisms underlying the direct action of phthalate within the fetal testis. We aimed to investigate the direct mechanisms of action of mono-(2-ethylhexyl) phthalate (MEHP) on the rat fetal testis, focusing on Leydig cell steroidogenesis in particular. We used an in vitro system based on the culture for three days, with or without MEHP, of rat fetal testes obtained at 14.5 days post-coitum.Exposure to MEHP led to a dose-dependent decrease in testosterone production. Moreover, the production of 5 alpha-dihydrotestosterone (5α-DHT) (-68%) and androstenedione (-54%) was also inhibited by 10 µM MEHP, whereas 17 alpha-hydroxyprogesterone (17α-OHP) production was found to increase (+41%). Testosterone synthesis was rescued by the addition of androstenedione but not by any of the other precursors used. Thus, the hormone data suggested that steroidogenesis was blocked at the level of the 17,20 lyase activity of the P450c17 enzyme (CYP17), converting 17α-OHP to androstenedione. The subsequent gene expression and protein levels supported this hypothesis. In addition to Cyp17a1, microarray analysis showed that several other genes important for testes development were affected by MEHP. These genes included those encoding insulin-like factor 3 (INSL3), which is involved in controlling testicular descent, and Inha, which encodes the alpha subunit of inhibin B.These findings indicate that under in vitro conditions known to support normal differentiation of the fetal rat testis, the exposure to MEHP directly inhibits several important Leydig cell factors involved in testis function and that the Cyp17a1 gene is a specific target to MEHP explaining the MEHP-induced suppression of steroidogenesis observed.

  7. In utero exposure to di-(2-ethylhexyl) phthalate induces metabolic disorder and increases fat accumulation in visceral depots of C57BL/6J mice offspring

    PubMed Central

    Gu, Hailun; Liu, Yali; Wang, Wei; Ding, Lifeng; Teng, Weiping; Liu, Li

    2016-01-01

    Excessive visceral fat accumulation is associated with metabolic disorders. Di-(2-ethylhexyl) phthalate (DEHP), a candidate environmental obesogen, affects lipid metabolism and adipogenesis. Perinatal exposure to DEHP may be associated with metabolic disorders of dams and offspring. The aim of the present study was to explore the effects of exposure of pregnant dams to DEHP on the metabolism and fat distribution of their offspring, and to determine the mechanisms for these effects. Pregnant C57BL/6J mice were administered DEHP via gavage (0.05 or 500 mg/kg/day) from gestational days 1–19. Pups were sacrificed at nine weeks of age. Serum leptin, insulin, lipid and fasting glucose levels, and the weights of the inguinal (subcutaneous) and gonadal (visceral) fat pads were determined. mRNA expression levels of two developmental genes, T-box 15 (Tbx15) and glypican 4 (Gpc4) were detected in fat tissues. A 100% abortion rate was exhibited in 500 mg/kg DEHP-treated dams, whereas exposure to 0.05 mg/kg DEHP did not affect reproductive outcomes. Pups from the 0.05 mg/kg exposure group were used for subsequent experimentation. Serum leptin, insulin, lipid and fasting glucose concentrations in these pups were significantly higher than those of control pups (P<0.05). Although no significant change in body weight was detected, the visceral fat weights of DEHP-exposed pups were significantly higher than those of control pups (P<0.05). Compared with controls, mRNA expression levels of Tbx15 in subcutaneous fat and Gpc4 in visceral fat were significantly increased among DEHP-exposed pups (P<0.01). The present results suggest that in utero exposure to an environmentally safe dose of DEHP may lead to excessive visceral fat accumulation and metabolic disorders in offspring and that aberrant expression of Tbx15 and Gpc4 may have an important role in these effects. PMID:28105114

  8. Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): kinetic and penetration study.

    PubMed

    Goulas, Antonios E; Zygoura, Panagiota; Karatapanis, Andreas; Georgantelis, Dimitris; Kontominas, Michael G

    2007-04-01

    Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25+/-1 degrees C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240h of contact (kinetic study) and a second group was cut into slices (1.5mm thick) after 240h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31mg/dm(2) film or 81.4mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3mg/dm(2) of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46mg/dm(2) (36.1mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5mm).

  9. Acute Exposure to Di(2-Ethylhexyl) Phthalate in Adulthood Causes Adverse Reproductive Outcomes Later in Life and Accelerates Reproductive Aging in Female Mice

    PubMed Central

    Hannon, Patrick R.; Niermann, Sarah; Flaws, Jodi A.

    2016-01-01

    Humans are ubiquitously exposed to di(2-ethylhexyl) phthalate (DEHP), which is an environmental toxicant incorporated in consumer products. Studies have shown that DEHP targets the ovary to disrupt essential processes required for reproductive and nonreproductive health. Specifically, 10-day exposure to DEHP accelerates primordial follicle recruitment and disrupts estrous cyclicity in adult mice. However, it is unknown if these effects on folliculogenesis and cyclicity following acute DEHP exposure can have permanent effects on reproductive outcomes. Further, the premature depletion of primordial follicles can cause early reproductive senescence, and it is unknown if acute DEHP exposure accelerates reproductive aging. This study tested the hypothesis that acute DEHP exposure causes infertility, disrupts estrous cyclicity, alters hormone levels, and depletes follicle numbers by inducing atresia later in life, leading to accelerated reproductive aging. Adult CD-1 mice were orally dosed with vehicle or DEHP (20 μg/kg/day–500 mg/kg/day) daily for 10 days, and reproductive outcomes were assessed at 6 and 9 months postdosing. Acute DEHP exposure significantly altered estrous cyclicity compared to controls at 6 and 9 months postdosing by increasing the percentage of days the mice were in estrus and metestrus/diestrus, respectively. DEHP also significantly decreased inhibin B levels compared to controls at 9 months postdosing. Further, DEHP significantly increased the BAX/BCL2 ratio in primordial follicles leading to a significant decrease in primordial and total follicle numbers compared to controls at 9 months postdosing. Collectively, the adverse effects present following acute DEHP exposure persist later in life and are consistent with accelerated reproductive aging. PMID:26678702

  10. Di-(2-ethylhexyl) phthalate could disrupt the insulin signaling pathway in liver of SD rats and L02 cells via PPARγ.

    PubMed

    Zhang, Wang; Shen, Xin-Yue; Zhang, Wen-Wen; Chen, Hao; Xu, Wei-Ping; Wei, Wei

    2017-02-01

    Di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous industrial pollutant in our daily life, has been reported to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies previously. Recently, it has been reported to be an endocrine disrupter and ligand to peroxisome proliferator activated receptor, which could influence the homeostasis of liver metabolic systems and contribute to the development of type-2 diabetes. However, the potential mechanisms are not known yet. This study was designed to solve these problems with male SD rats and normal human hepatocyte line, L02 cells, exposed to DEHP for toxicological experiments. Adult male SD rats were divided into four groups, normal group fed with regular diets and three DEHP-treated groups (dissolved in olive oil at doses of 0.05, 5 and 500mg/kg body weight, respectively, once daily through gastric intubations for 15weeks). L02 cells were divided into 6 groups, normal group with 5, 10, 25, 50, and 100μmol/l DEHP groups. DEHP-exposed rats exhibited significant liver damage, glucose tolerance, and insulin tolerance along with reduced expression of insulin receptor and GLUT4 proteins in the liver tissues. The results of in vitro experiments could determine that the DEHP-induced activation of peroxisome proliferator activated receptor γ (PPARγ) played a key role in the production of oxidative stress and down-regulated expression of insulin receptor and GLUT4 proteins in L02 cells. This conclusion could be supported by the results of in vitro experiments, in which the cells were exposed to DEHP with GW9662 (PPARγ inhibitor). In general, these results highlight the key role of PPARγ in the process of insulin resistance induced by DEHP.

  11. Di(2-ethylhexyl) phthalate induces a functional zinc deficiency during pregnancy and teratogenesis that is independent of peroxisome proliferator-activated receptor-alpha.

    PubMed

    Peters, J M; Taubeneck, M W; Keen, C L; Gonzalez, F J

    1997-11-01

    Di(2-ethylhexyl) phthalate (DEHP) is a peroxisome proliferator whose administration to rodents induces a pleiotropic response mediated by the peroxisome proliferator-activated receptor-alpha (PPAR alpha). The mechanisms underlying DEHP-induced reproductive toxicity and teratogenicity are not well understood but could be the result of an alteration in gene expression by PPAR alpha. Additionally, phthalate exposure is known to impair fetal zinc (Zn) levels during pregnancy. In this work, we investigated whether the reproductive toxicity and teratogenicity of DEHP are mediated by PPAR alpha and whether the receptor influences maternal and/or embryonic Zn metabolism. Pregnant female mice, homozygous wild-type (+/+) or PPAR alpha -null (-/-), were intubated with either vehicle alone or 1,000 mg DEHP/kg body weight on gestation day (GD) 8 and 9. Pregnancy outcome was evaluated on GD10 and GD18 in two cohorts of animals. Compared to controls, DEHP administration resulted in maternal toxicity, embryo/ fetal toxicity, and teratogenicity in both (+/+) and (-/-) mice. Maternal liver mRNA for cytochrome P-450 4A1 (CYP4A1) was higher in DEHP-treated (+/+) mice but not in DEHP-treated (-/-) mice on GD10, consistent with their respective phenotype. Maternal liver MT and Zn levels were significantly higher than in controls on GD10. In addition, embryonic Zn content was significantly lower in both genotypes treated with DEHP compared to controls. Results from this work show that DEHP-induced reproductive toxicity, teratogenicity, and altered Zn metabolism are not mediated through PPAR alpha-dependent mechanisms. In addition, this work suggests that DEHP-induced alterations in Zn metabolism contribute to the mechanisms underlying DEHP-induced reproductive toxicity and teratogenicity.

  12. Toxic effects of di(2-ethylhexyl)phthalate on mortality, growth, reproduction and stress-related gene expression in the soil nematode Caenorhabditis elegans.

    PubMed

    Roh, Ji-Yeon; Jung, In-Ho; Lee, Jai-Young; Choi, Jinhee

    2007-07-31

    In this study, di(2-ethylhexyl)phthalate (DEHP) toxicities to Caenorhabditis elegans were investigated using multiple toxic endpoints, such as mortality, growth, reproduction and stress-related gene expression, focusing on the identification of chemical-induced gene expression as a sensitive biomarker for DEHP monitoring. The possible use of C. elegans as a sentinel organism in the monitoring of soil ecosystem health was also tested by conducting the experiment on the exposure of nematode to field soil. Twenty-four-hour median lethal concentration (LC50) data suggest that DEHP has a relatively high potential of acute toxicity to C. elegans. Decreases in body length and egg number per worm observed after 24h of DEHP exposure may induce long-term alteration in the growth and reproduction of the nematode population. Based on the result from the C. elegans genome array and indicated in the literatures, stress proteins, metallothionein, vitellogenin, xenobiotic metabolism enzymes, apoptosis-related proteins, and antioxidant enzyme genes were selected as stress-related genes and their expression in C. elegans by DEHP exposure was analyzed semi-quantitatively. Expression of heat shock protein (hsp)-16.1 and hsp-16.2 genes was decreased by DEHP exposure. Expression of cytochrome P450 (cyp) 35a2 and glutathione-S-transferease (gst)-4, phase I and phase II of xenobiotic metabolism enzymes, was increased by DEHP exposure in a concentration-dependent manner. An increase in stress-related gene expressions occurred concomitantly with the deterioration on the physiological level, which suggests an increase in expression of those genes may not be considered as a homeostatic response but as a toxicity that might have physiological consequences. The experiment with the soil from the landfill site suggests that the potential of the C. elegans biomarker identified in laboratory conditions should be calibrated and validated for its use in situ.

  13. Effects of uterine and lactational exposure to di-(2-ethylhexyl) phthalate on spatial memory and NMDA receptor of hippocampus in mice.

    PubMed

    Dai, Yuhua; Yang, Yanling; Xu, Xiaohong; Hu, Yizhong

    2015-05-01

    Di-(2-ethylhexyl) phthalate (DEHP) is an environmental endocrine disrupter. Currently, little is known about neurodevelopmental toxicity of DEHP in wildlife and humans. The present study investigated the effects of DEHP, focusing on the changes in the behavior of offspring mice at the ages of 6 and 12w, respectively, following utero and lactational exposure to DEHP (10, 50, and 200mg/kg/d) from gestation day 7 through postnatal day 21. The results of open field tasks showed that DEHP increased the grooming of males at age 6w and females at age 12w but decreased the frequency of rearing of 6-w-old females and the number of grid crossings of 12-w-old females. In the Morris water maze task, 50 and 200mg/kg/d DEHP significantly prolonged the time of searching the hidden platform in water maze and reduced the time staying in the target quadrant during a probe trial of 6-w-old male mice, but not of 6-w-old females nor 12-w-old mice of both sexes, suggesting an impaired spatial learning and memory among younger males after perinatal exposure to DEHP. Western blot analyses further showed that DEHP at 50 and 200mg/kg/d decreased the levels of the N-methyl-d-aspartic acid (NMDA) receptor subunits NR1 and NR2B in the hippocampus of 6-w-old males. These results suggest that uterine and lactational exposure to low doses of DEHP sex-specifically impacted behaviors, including locomotion activity and spatial memory, via the concomitant inhibition of the NMDA receptor of the hippocampus in offspring mice.

  14. Self-assembly and intra-cluster reactions of erbium and ytterbium bis(2-ethylhexyl)sulfosuccinates in the gas phase.

    PubMed

    Indelicato, Serena; Bongiorno, David; Turco Liveri, Vincenzo; Mele, Andrea; Panzeri, Walter; Castiglione, Francesca; Ceraulo, Leopoldo

    2014-12-15

    The study of surfactant organization in vacuum allows surfactant-surfactant interaction to be unveiled in the absence of surrounding solvent molecules. Knowledge on their chemical-physical properties may also lead to the definition of more efficient gas-phase carriers, air-cleaning agents and nanoreactors. In addition, the presence of lanthanide-group ions adds unique photochemical properties to surfactants. The structural features, stability and fragmentation patterns of charged aggregates formed by lanthanide-functionalized surfactants, ytterbium and erbium bis(2-ethylhexyl)sulfosuccinate ((AOT)3Yb and (AOT)3Er), have been investigated by electrospray ionization mass spectrometry (ESI-MS), tandem mass spectrometry (ESI-MS/MS) and energy-resolved mass spectrometry (ER-MS). The experimental data indicate that the self-assembling of (AOT)3Yb and (AOT)3Er in the gas phase leads to the formation of a wide range of singly charged aggregates differing in their aggregation number, relative abundance and stability. In addition to specific effects on aggregate organization due to the presence of lanthanide ions, ER-MS experiments show rearrangements and in-cage reactions activated by collision, eventually including alkyl chain intra-cluster migration. Analysis of the experimental findings suggests that the observed chemical transformations occur within an organized supramolecular assembly rather than in a random association of components. The fragmentation pathways leading to the neutral loss of a fragment of nominal mass 534 Da, assigned as C28 H54 O7 S, from some positively charged aggregates has been rationalized. Copyright © 2014 John Wiley & Sons, Ltd.

  15. Development of a simple method for predicting the levels of di(2-ethylhexyl) phthalate migrated from PVC medical devices into pharmaceutical solutions.

    PubMed

    Haishima, Yuji; Seshimo, Fumie; Higuchi, Tae; Yamazaki, Haruko; Hasegawa, Chie; Izumi, Shun-ichiro; Makino, Tsunehisa; Nakahashi, Keisuke; Ito, Rie; Inoue, Koichi; Yoshimura, Yoshihiro; Saito, Koichi; Yagami, Takeshi; Tsuchiya, Toshie; Nakazawa, Hiroyuki

    2005-07-14

    This study deals with the development of a simple method for predicting the elution levels of di-2-ethylhexyl phthalate (DEHP) from medical devices made of polyvinyl chloride (PVC) by using the physicochemical properties of pharmaceutical injections as a marker. GC-MS analysis showed that the release of DEHP from medical grade PVC product was concentration-dependently increased by extraction with two kinds of lipophilic injections (Sandimmun and Prograf) and three kinds of surfactants (HCO-60, Tween 80, and SDS). The solubility of lipophilic pigments such as Sudan III, methyl yellow, and 1,4-diamino-anthraquinone against these solutions were also increased in a concentration-dependent manner, in which methyl yellow showed the highest response regarding the increase of optical density (O.D.). Further, electrical conductivity and static contact angle to the PVC sheet of the solutions were also increased or decreased in the same manner. As a result of the comparative study, significant correlation was found between DEHP release levels and these three physicochemical properties, particularly methyl yellow solubility, of the solutions tested. To evaluate the relationship in detail, DEHP release levels from PVC tubing and methyl yellow solubility of 53 injections used in gynecologic and obstetric fields were determined. None of the hydrophilic medicines showed any significant release of DEHP, and all showed low solubility of methyl yellow. On the other hand, the lipophilic medicines releasing a large amount of DEHP showed high solubility of methyl yellow (greater than O.D. 0.8). These results indicate that a significant proportional relationship exists between DEHP release potency and methyl yellow solubility of pharmaceutical solutions, and the risk of DEHP exposure to the patients administered pharmaceuticals through transfusion set could be easily predicted by the solubility test without complicated elution tests of DEHP using GC-MS or LC-MS.

  16. In utero exposure to di-(2-ethylhexyl) phthalate induces metabolic disorder and increases fat accumulation in visceral depots of C57BL/6J mice offspring.

    PubMed

    Gu, Hailun; Liu, Yali; Wang, Wei; Ding, Lifeng; Teng, Weiping; Liu, Li

    2016-12-01

    Excessive visceral fat accumulation is associated with metabolic disorders. Di-(2-ethylhexyl) phthalate (DEHP), a candidate environmental obesogen, affects lipid metabolism and adipogenesis. Perinatal exposure to DEHP may be associated with metabolic disorders of dams and offspring. The aim of the present study was to explore the effects of exposure of pregnant dams to DEHP on the metabolism and fat distribution of their offspring, and to determine the mechanisms for these effects. Pregnant C57BL/6J mice were administered DEHP via gavage (0.05 or 500 mg/kg/day) from gestational days 1-19. Pups were sacrificed at nine weeks of age. Serum leptin, insulin, lipid and fasting glucose levels, and the weights of the inguinal (subcutaneous) and gonadal (visceral) fat pads were determined. mRNA expression levels of two developmental genes, T-box 15 (Tbx15) and glypican 4 (Gpc4) were detected in fat tissues. A 100% abortion rate was exhibited in 500 mg/kg DEHP-treated dams, whereas exposure to 0.05 mg/kg DEHP did not affect reproductive outcomes. Pups from the 0.05 mg/kg exposure group were used for subsequent experimentation. Serum leptin, insulin, lipid and fasting glucose concentrations in these pups were significantly higher than those of control pups (P<0.05). Although no significant change in body weight was detected, the visceral fat weights of DEHP-exposed pups were significantly higher than those of control pups (P<0.05). Compared with controls, mRNA expression levels of Tbx15 in subcutaneous fat and Gpc4 in visceral fat were significantly increased among DEHP-exposed pups (P<0.01). The present results suggest that in utero exposure to an environmentally safe dose of DEHP may lead to excessive visceral fat accumulation and metabolic disorders in offspring and that aberrant expression of Tbx15 and Gpc4 may have an important role in these effects.

  17. Di(2-ethylhexyl)phosphoric acid-coconut oil supported liquid membrane for the separation of copper ions from copper plating wastewater.

    PubMed

    Venkateswaran, P; Navaneetha Gopalakrishnan, A; Palanivelu, K

    2007-01-01

    Permeation of Cu(II) from its aqueous solution through a supported liquid membrane (SLM) containing di(2-ethylhexyl)phosphoric acid (D2EHPA) carrier dissolved in coconut oil has been studied. The effects of Cu(II), pH (in feed), H2SO4 (stripping) and D2EHPA (in membrane) concentrations have been investigated. The stability of the D2EHPA-coconut oil has also been evaluated. High Cu(II) concentration in the feed leads to an increase in flux from 4.1 x 10(-9) to 8.9 x 10(-9) mol/(m2 x s) within the Cu(II) concentration range 7.8 x 10(-4)-78.6 x 10(-4) mol/L at pH of 4.0 in the feed and 12.4 x 10-4 mol/L D2EHPA in the membrane phase. Increase in H2SO4 concentration in strip solution leads to an increase in copper ions flux up to 0.25 mol/L H2SO4, providing a maximum flux of 7.4 x 10(-9) mol/(m2 x s). The optimum conditions for Cu(II) transport are, pH of feed 4.0, 0.25 mol/L H2SO4 in strip phase and 12.4 x 10(-4) mol/L D2EHPA (membrane) in 0.5 microm pore size polytetrafluoroethylene (PTFE) membrane. It has been observed that Cu(II) flux across the membrane tends to increase with the concentration of copper ions. Application of the method developed to copper plating bath rinse solutions has been found to be successful in the recovery of Cu(II).

  18. Variability over 1 Week in the Urinary Concentrations of Metabolites of Diethyl Phthalate and Di(2-Ethylhexyl) Phthalate among Eight Adults: An Observational Study

    PubMed Central

    Preau, James L.; Wong, Lee-Yang; Silva, Manori J.; Needham, Larry L.; Calafat, Antonia M.

    2010-01-01

    Background Phthalates are metabolized and eliminated in urine within hours after exposure. Several reports suggest that concentrations of phthalate metabolites in a spot urine sample can provide a reliable estimation of exposure to phthalates for up to several months. Objectives We examined inter- and intraperson and inter- and intraday variability in the concentrations of monoethyl phthalate (MEP), the major metabolite of diethyl phthalate, commonly used in personal care products, and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), a metabolite of di(2-ethylhexyl) phthalate (DEHP), a polyvinyl chloride plasticizer of which diet is the principal exposure source, among eight adults who collected all urine voids (average, 7.6 samples/person/day) for 1 week. Methods We analyzed the urine samples using online solid-phase extraction coupled to isotope dilution–high-performance liquid chromatography–tandem mass spectrometry. Results Regardless of the type of void (spot, first morning, 24-hr collection), for MEP, interperson variability in concentrations accounted for > 75% of the total variance. By contrast, for MEHHP, within-person variability was the main contributor (69–83%) of the total variance. Furthermore, we observed considerable intraday variability in the concentrations of spot samples for MEHHP (51%) and MEP (21%). Conclusions MEP and MEHHP urinary concentrations varied considerably during 1 week, but the main contributors to the total variance differed (interday variability, MEHHP; interperson variability, MEP) regardless of the sampling strategy (spot, first morning, 24-hr collection). The nature of the exposure (diet vs. other lifestyle factors) and timing of urine sampling to evaluate exposure to phthalates should be considered. For DEHP and phthalates to which people are mostly exposed through diet, collecting 24-hr voids for only 1 day may not be advantageous compared with multiple spot collections. When collecting multiple spot urine samples

  19. Adsorption and Fenton regeneration of SBA-15 for di-(2-ethylhexyl) phthalate leached from PVC sheets by Gram-positive strains LHM1 and LHM2

    NASA Astrophysics Data System (ADS)

    Hwang, S.; Latorre, I.; Caban, M.; Soto, B.; Montalvo-Rodríguez, R.; Hernández-Maldonado, A.

    2012-12-01

    Bioleaching of Di-(2-ethylhexyl) phthalate (DEHP) from PVC sheets was studied with newly isolated, Gram-positive strains LHM1 and LHM2 capable of growing on DEHP as the sole carbon source. According to 16S rRNA gene analysis, strains LHM1 and LHM2 were closely related (more than 97% similarity) to Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. The biodeteriorated PVC sheets by the strains LHM1 and LHM2 had thicker biofilm development. Despite their metabolic capability of degrading DEHP as the sole carbon source, the strains LHM1 and LHM2 did not metabolize all DEHP leached out of the PVC sheets. Thermogravimetric analysis (TGA) showed that the biodeterioration by strains LHM1 and LHM2 resulted in less amount of and weakly bonded DEHP present in PVC sheets, in comparison to the virgin PVC sheet. Therefore, PVC biodeterioration by strains LHM1 and LHM2 might play an important role in stability of PVC sheets and fate and effect of leached DEHP on the environmental receptors. In response to this, an advanced adsorption with SBA-15 was assessed as a potential alternative DEHP remediation with arsenic as a co-contaminant. SBA-15 had an excellent arsenic adsorption showing >90% arsenic removal when arsenic was present as a singular contaminant. Adsorption effectiveness was irrelevant to the solid/liquid (S/L) ratio. However, when arsenic was present together with DEHP, arsenic adsorption to bare SBA-15 was reduced by 10 - 40%, with lesser S/L ratio having greater arsenic removal. On the contrary, bare SBA-15 only adsorbed ~30% of DEHP on average. When DEHP was present as a co-solute with arsenic, DEHP adsorption to bare SBA-15 was increased. For SBA-15 regeneration, adsorbed arsenic was recovered with EDTA elution, whereas adsorbed DEHP was destructed with Fenton oxidation.

  20. Evaluation of subchronic (13 week), reproductive, and in vitro genetic toxicity potential of 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (Octocrylene).

    PubMed

    Odio, M R; Azri-Meehan, S; Robison, S H; Kraus, A L

    1994-04-01

    Use of 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (Octocrylene) in commercial sunscreen products has increased considerably in recent years. To support larger scale human exposure to this compound, additional toxicological information was needed in several key areas. The present studies evaluated subchronic toxicity, developmental toxicity, and in vitro genotoxic potential of Octocrylene. In the subchronic study, male and female New Zealand white (NZW) rabbits treated topically with concentrations of octocrylene up to 534 mg/kg/day for 13 weeks showed slight to moderate dose-dependent skin irritation that correlated positively with a mild depression in body weight gain. Lack of associated histopathologic or clinical hematology abnormalities suggested that the body weight effect probably reflected a nonspecific response to topical irritation. In percutaneous developmental toxicity studies, NZW does were treated topically with Octocrylene at levels up to 267 mg/kg/day on Days 6 through 18 of gestation. Body weight gain, food consumption, and all maternal, reproductive, and offspring parameters evaluated were comparable between Octocrylene-treated and control animals. In the oral developmental toxicity assay, female CD-1 mice received oral doses of Octocrylene up to 1000 mg/kg/day on Days 8-12 of gestation. No evidence of maternal or developmental toxicity was seen at any dose tested. Genotoxicity was evaluated in vitro using the Chinese hamster ovary cell assay to assess clastogenicity and the mouse lymphoma cell assay to assess forward gene mutations. Octocrylene did not induce any significant increase in genotoxicity. This evaluation of toxicological potential supports the use of Octocrylene as a human photoprotectant.

  1. The roles of hippocampal microRNAs in response to acute postnatal exposure to di(2-ethylhexyl) phthalate in female and male rats.

    PubMed

    Luu, Bryan E; Green, Stuart R; Childers, Christine L; Holahan, Matthew R; Storey, Kenneth B

    2017-02-10

    Previous studies have shown that di(2-ethylhexyl) phthalate (DEHP) exposure impairs the normal development of pre- and post-synaptic elements of the male, but not female, rat hippocampus. While males seem to be vulnerable to the neurodevelopmental deficits resulting from DEHP exposure, females appear to show a protective response. The purpose of the present study was to characterize hippocampal microRNAs in female and male rats exposed to DEHP to assess whether any patterns emerged that would be consistent with vulnerability in males and resilience in females. Male and female rats were treated with 0, 1, 10, or 20mg/kg of DEHP by intraperitoneal injections from postnatal day 16 (PND16) - PND22 and brains were removed and flash frozen on PND78. A group of 85 microRNAs which have been previously shown to play a role in the development and maintenance of hippocampal neurons was assessed with RT-qPCR. In response to DEHP exposure, there were 19 microRNAs that increased in females and 52 that decreased in males. The strongest microRNA response in females occurred in conjunction with the 10mg/kg of DEHP dose, whereas suppression of microRNAs in males appeared to be dose-dependent. Select hippocampal microRNAs (such as miR-132-3p and miR-191-5p), previously shown to regulate dendrite morphology, were modulated by DEHP exposure in this study. The results suggest that DEHP exposure has the potential to regulate microRNAs in a sex-specific manner which may interfere with proper hippocampal development in males and preserve hippocampal development in females.

  2. Genotypic variation in the uptake, accumulation, and translocation of di-(2-ethylhexyl) phthalate by twenty cultivars of rice (Oryza sativa L.).

    PubMed

    Cai, Quan-Ying; Xiao, Pei-Yun; Chen, Tong; Lü, Huixiong; Zhao, Hai-Ming; Zeng, Qiao-Yun; Li, Yan-Wen; Li, Hui; Xiang, Lei; Mo, Ce-Hui

    2015-06-01

    Agricultural soil in China contains high levels of di-(2-ethylhexyl) phthalate (DEHP), especially in paddy-field soil of Guangdong province of China, but the accumulation and translocation of DEHP by rice (Oryza sativa L.) remains unknown. In the present study, twenty rice cultivars were cultivated in paddy soil spiked with DEHP, and variations in DEHP accumulation and translocation among various cultivars were investigated. Our results showed that DEHP concentrations in roots and shoots of different rice cultivars at four growth stages (i.e., ripening, tillering, jointing, and flowering stages) varied greatly from 0.26 to 11.8 mg/kg (dry weight, dw) and 0.40 to 7.58 mg/kg (dw), respectively. No obvious change over time was observed. The greatest variation in DEHP concentrations among the rice cultivars occurred at ripening stage, whereas the lowest variation at flowering stage. During ripening stage, the largest variation in DEHP concentrations among cultivars were observed in stems (varying from 0.35 to 13.2 mg/kg), whereas the least one was observed in roots (ranging from 1.01 to 5.72 mg/kg). Significant differences in DEHP concentrations in the roots, stems, leaves and grains of most rice cultivars were found. The translocation factors of DEHP from roots to stems or stems to leaves were higher than those from shoots to grains. Overall, cultivars Tianfengyou 316, Wuyou 308, and Peizataifeng, which contained low levels of DEHP in grains but high levels in shoots, were ideal cultivars for simultaneous production of safe food and phytoremediation of contaminated soil. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Biodegradable Polymers

    PubMed Central

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. The following review presents an overview of the different biodegradable polymers that are currently being used and their properties, as well as new developments in their synthesis and applications.

  4. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    USDA-ARS?s Scientific Manuscript database

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

  5. Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore.

    PubMed

    Biswas, Sujoy; Pathak, P N; Roy, S B

    2012-06-01

    An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λ(max)) for UO(2)(2+)-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol(-1)cm(-1)). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to > 24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO(2)(2+)-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is < 2%. The accuracy of the developed method has been checked by determining uranium using standard addition method and was found to be accurate with a 98-105% recovery rate. The developed method has been applied for the analysis of a number of uranium samples generated from uranium ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ± 2%. This method can be used to determine 2.5-250 μg mL(-1) uranium in ore leach solutions with high accuracy and precision.

  6. The coordination structure of the extracted nickel(ii) complex with a synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester.

    PubMed

    Li, Jiyuan; Hu, Huiping; Zhu, Shan; Hu, Fang; Wang, Yongxi

    2017-01-24

    In this paper, a synergist complex of Ni(ii) with naphthalene-2-sulfonic acid (HNS) and n-hexyl 4-pyridinecarboxylate ester (L(I)), which are corresponding short chain analogues of active synergistic extractants dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexyl 4-pyridinecarboxylate ester (4PC, L(II)), was prepared and characterized by Nuclear Magnetic Resonance ((1)H-NMR), elemental analyses, Fourier Transform Infrared Spectroscopy (FT-IR) and Electrospray Ionization Mass Spectrometry (ESI-MS) spectroscopic studies. Single crystals of the nickel synergist complex have been grown from a methanol/water (10/1) solution and analyzed by single crystal X-ray diffraction. The crystal structure of the nickel synergist complex shows that Ni(ii) is coordinated by four water molecules and two monodentate L(I) ligands and there is no direct interaction of the Ni(ii) with sulfonic oxygen atoms of naphthalene-2-sulfonic acid anions, while hydrogen-bonded interactions of the coordinated water molecules with sulfonic oxygen atoms of naphthalene-2-sulphate anions were observed. In addition, in order to provide parallels to solvent extraction, the extracted Ni(ii) complex with HDNNS and 4PC is also prepared and studied using FT-IR and ESI-MS technology. Compared with their corresponding free ligand, similar shifts assigned to the stretching vibration of the pyridine ring and S[double bond, length as m-dash]O in both the nickel synergist complex and the extracted Ni(ii) complex suggest that in the non-polar organic phase, Ni(ii) is also coordinated by L(II) ligands, while the sulfonic oxygen atoms of dinonylnaphthalene sulfonate anions not directly bonded to Ni(ii) form hydrogen bonds with water molecules (coordinated with Ni(ii) or/and solubilized in the non-polar organic phase). For the ESI-MS spectrum of the extracted Ni(ii) complex in non-polar organic phase, there exists a peak at m/z values of 1058.76, which indicates that the extracted Ni(ii) complex in the non

  7. The effect of linoleic acid on pH inside sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles in isooctane and on the enzymic activity of soybean lipoxygenase.

    PubMed

    Rodakiewicz-Nowak, J; Maślakiewicz, P; Haber, J

    1996-06-01

    The effective pH of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles (pHrm), containing buffers of different pH (pHst) and various amounts of linoleic acid, was studied within the range of compositions used to study the activity of soybean lipoxygenase in reverse micelles. Significant shifts of pHrm versus pHst were observed for the solutions of relatively higher pHst, dependent on linoleic acid and buffer concentrations. The effect diminished as pHst became closer to 7. When low-ionic-strength buffers were added to AOT solutions in isooctane, a significant buffering effect of linoleic acid in reverse micelles was observed. Solubilization of > 3 mM linoleic acid in micellar solutions containing 25 mM buffers gave the observed pHrm values almost independent of pHst. This effect diminished with the ionic strength of the buffering solution, but did not vanish even at 200 mM buffer. The observed effects result from the balance between ionization of linoleic acid and its partition between the water pool and the micellar interface. The enzymic activity of soybean lipoxygenase in the AOT reverse micellar solutions of the determined pHrm values was also studied. A significant reduction of the kinetics of the enzymic activity was observed, for all studied reverse micellar solutions. Changes of pHrm, caused by the presence of acidic substrate (linoleic acid) do not explain the observed reduction of activity directly through the effect on the enzyme. Due to unfavourable partition of the substrate between the microphases present in the systems, enhanced by reduction of pH at higher total concentrations of linoleic acid, the saturation of the enzyme with the substrate was not observed in the system and is difficult to attain experimentally in reverse micelles. A shift of the lipoxygenase activity/pHrm profile but negligible shift of the activity/pHst profile, with respect to aqueous buffer solutions, were observed. This indicates that either the information given

  8. Rodent Thyroid, Liver, and Fetal Testis Toxicity of the Monoester Metabolite of Bis-(2-ethylhexyl) Tetrabromophthalate (TBPH), a Novel Brominated Flame Retardant Present in Indoor Dust

    PubMed Central

    Springer, Cecilia; Dere, Edward; Hall, Susan J.; McDonnell, Elizabeth V.; Roberts, Simon C.; Butt, Craig M.; Stapleton, Heather M.; Watkins, Deborah J.; McClean, Michael D.; Webster, Thomas F.; Schlezinger, Jennifer J.

    2012-01-01

    Background: Bis-(2-ethylhexyl) tetrabromophthalate (TBPH) is widely used as a replacement for polybrominated diphenyl ethers (PBDEs) in commercial flame retardant mixtures such as Firemaster 550. It is also used in a commercial mixture called DP 45. Mono-(2-ethyhexyl) tetrabromophthalate (TBMEHP) is a potentially toxic metabolite. Objectives: We used in vitro and rodent in vivo models to evaluate human exposure and the potential metabolism and toxicity of TBPH. Methods: Dust collected from homes, offices, and cars was measured for TBPH by gas chromatography followed by mass spectrometry. Pregnant rats were gavaged with TBMEHP (200 or 500 mg/kg) or corn oil on gestational days 18 and 19, and dams and fetuses were evaluated histologically for toxicity. We also assessed TBMEHP for deiodinase inhibition using rat liver microsomes and for peroxisome proliferator-activated receptor (PPAR) α and γ activation using murine FAO cells and NIH 3T3 L1 cells. Results: TBPH concentrations in dust from office buildings (median, 410 ng/g) were higher than in main living areas in homes (median, 150 ng/g). TBPH was metabolized by purified porcine esterases to TBMEHP. Two days of TBMEHP exposure in the rat produced maternal hypothyroidism with markedly decreased serum T3 (3,3´,5-triiodo-l-thyronine), maternal hepatotoxicity, and increased multinucleated germ cells (MNGs) in fetal testes without antiandrogenic effects. In vitro, TBMEHP inhibited deiodinase activity, induced adipocyte differentiation in NIH 3T3 L1 cells, and activated PPARα- and PPARγ-mediated gene transcription in NIH 3T3 L1 cells and FAO cells, respectively. Conclusions: TBPH a) is present in dust from indoor environments (implying human exposure) and b) can be metabolized by porcine esterases to TBMEHP, which c) elicited maternal thyrotoxic and hepatotoxic effects and d) induced MNGs in the fetal testes in a rat model. In mouse NIH 3T3 L1 preadipocyte cells, TBMEHP inhibited rat hepatic microsome deiodinase

  9. Transgenerational effects of Di (2-ethylhexyl) phthalate in the male CRL:CD(SD) rat: added value of assessing multiple offspring per litter.

    PubMed

    Gray, Leon Earl; Barlow, Norman J; Howdeshell, Kembra L; Ostby, Joseph S; Furr, Johnathan R; Gray, Clark L

    2009-08-01

    In the rat, some phthalates alter sexual differentiation at relatively low dosage levels by altering fetal Leydig cell development and hormone synthesis, thereby inducing abnormalities of the testis, gubernacular ligaments, epididymis, and other androgen-dependent tissues. In order to define the dose-response relationship between di(2-ethylhexyl) phthalate (DEHP) and the Phthalate Syndrome of reproductive alterations in F1 male rats, Sprague-Dawley (SD) rat dams were dosed by gavage from gestational day 8 to day 17 of lactation with 0, 11, 33, 100, or 300 mg/kg/day DEHP (71-93 males per dose from 12 to 14 litters per dose). Some of the male offspring continued to be exposed to DEHP via gavage from 18 days of age to necropsy at 63-65 days of age (PUB cohort; 16-20/dose). Remaining males were not exposed after postnatal day 17 (in utero-lactational [IUL] cohort) and were necropsied after reaching full maturity. Anogenital distance, sperm counts and reproductive organ weights were reduced in F1 males in the 300 mg/kg/day group and they displayed retained nipples. In the IUL cohort, seminal vesicle weight also was reduced at 100 mg/kg/day. In contrast, serum testosterone and estradiol levels were unaffected in either the PUB or IUL cohorts at necropsy. A significant percentage of F1 males displayed one or more Phthalate Syndrome lesions at 11 mg/kg/day DEHP and above. We were able to detect effects in the lower dose groups only because we examined all the males in each litter rather than only one male per litter. Power calculations demonstrate how using multiple males versus one male/litter enhances the detection of the effects of DEHP. The results at 11 mg/kg/day confirm those reported from a National Toxicology Program multigenerational study which reported no observed adverse effect levels-lowest observed adverse effect levels of 5 and 10 mg/kg/day DEHP, respectively, via the diet.

  10. Designing green plasticizers: influence of alkyl chain length on biodegradation and plasticization properties of succinate based plasticizers.

    PubMed

    Erythropel, Hanno C; Dodd, Patrick; Leask, Richard L; Maric, Milan; Cooper, David G

    2013-04-01

    Phthalate diesters such as di (2-ethylhexyl) phthalate (DEHP) are considered ubiquitous contaminants and are poorly biodegraded in the environment. Moreover, both the parent compound and stable metabolites such as mono (2-ethylhexyl) phthalate (MEHP) are linked to several negative impacts on the environment and human health. Earlier work established that saturated diester compounds, such as succinates, showed better biodegradation characteristics and comparable plasticizer properties compared to DEHP. In this work we examine the effect of alkyl chain length of succinate molecules on plasticizer and biodegradation properties. This included both the side chains (n-ethyl to n-octyl) as well as substituents on the middle part of the succinate molecule. We showed that the common soil bacterium Rhodococcus rhodocrous could rapidly break down all unsubstituted succinates, without the appearance of stable metabolites. Furthermore, the organisms used the plasticizer metabolites as carbon source. The introduction of a large cyclohexyl substituent on the succinate resulted in a poorer degradation rate. Glass Transition Temperature (Tg) measurements were performed to evaluate plasticizer properties and showed that longer side chains reduced the Tg more efficiently, while large cyclohexyl substituents on the succinate decreased this effect. However, all compounds performed better or equal to DEHP at reducing the Tg.

  11. Di(2-ethylhexyl)phthalate Alters the Synthesis and β-Oxidation of Fatty Acids and Hinders ATP Supply in Mouse Testes via UPLC-Q-Exactive Orbitrap MS-Based Metabonomics Study.

    PubMed

    Shen, Guolin; Zhou, Lili; Liu, Wei; Cui, Yuan; Xie, Wenping; Chen, Huiming; Yu, Wenlian; Li, Wentao; Li, Haishan

    2017-06-21

    Di(2-ethylhexyl) phthalate (DEHP) is considered to be an environmental endocrine disruptor at high levels of general exposure. Studies show that DEHP may cause testicular toxicity on human being. In this study, metabonomics techniques were used to identify differential endogenous metabolites, draw the network metabolic pathways, and conduct network analysis, to determine the underlying mechanisms of testicular toxicity induced by DEHP. The results showed that DEHP inhibited synthesis and accelerated β-oxidation of fatty acids and impaired the tricarboxylic acid cycle (TCA cycle) and gluconeogenesis, resulting in lactic acid accumulation and an insufficient ATP supply in the microenvironment of the testis. These alterations led to testicular atrophy and, thus, may be the underlying causes of testicular toxicity. DEHP also inhibited peroxisome proliferator activated receptors in the testis, which may be another potential reason for the testicular atrophy. These findings provided new insights to better understand the mechanisms of testicular toxicity induced by DEHP exposure.

  12. Decreased serum free testosterone in workers exposed to high levels of di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP): a cross-sectional study in China.

    PubMed

    Pan, Guowei; Hanaoka, Tomoyuki; Yoshimura, Mariko; Zhang, Shujuan; Wang, Ping; Tsukino, Hiromasa; Inoue, Koichi; Nakazawa, Hiroyuki; Tsugane, Shoichiro; Takahashi, Ken

    2006-11-01

    Observations of adverse developmental and reproductive effects in laboratory animals and wildlife have fueled increasing public concern regarding the potential for various chemicals to impair human fertility. Our objective in this study was to assess the effect of occupational exposure to high levels of phthalate esters on the balance of gonadotropin and gonadal hormones including luteinizing hormone, follicle-stimulating hormone, free testosterone (fT), and estradiol. We examined urine and blood samples of 74 male workers at a factory producing unfoamed polyvinyl chloride flooring exposed to di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) and compared them with samples from 63 male workers from a construction company, group matched for age and smoking status. Compared to the unexposed workers, the exposed workers had substantially and significantly elevated concentrations of mono-n-butyl phthalate (MBP; 644.3 vs. 129.6 microg/g creatinine, p < 0.001) and mono-2-ethylhexyl phthalate (MEHP; 565.7 vs. 5.7 microg/g creatinine, p < 0.001). fT was significantly lower (8.4 vs. 9.7 microg/g creatinine, p = 0.019) in exposed workers than in unexposed workers. fT was negatively correlated to MBP (r = -0.25, p = 0.03) and MEHP (r = -0.19, p = 0.095) in the exposed worker group. Regression analyses revealed that fT decreases significantly with increasing total phthalate ester score (the sum of quartiles of MBP and MEHP; r = -0.26, p = 0.002). We observed a modest and significant reduction of serum fT in workers with higher levels of urinary MBP and MEHP compared with unexposed workers.

  13. Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death

    SciTech Connect

    Guida, Natascia; Laudati, Giusy; Galgani, Mario; Santopaolo, Marianna; Montuori, Paolo; Triassi, Maria; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

    2014-10-01

    Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1–100 μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but not Sp3 mRNA, after 24 and 48 h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination. - Highlights: • Di(2-ethylhexyl)phthalate (DEHP) is cytotoxic to SH-SY5Y cells and cortical neurons. • DEHP-induced cytotoxicity is mediated by apoptosis. • DEHP-induced apoptotic cell death is inhibited by class II HDAC MC-1568. • DEHP neurotoxicity is caused by HDAC4-mediated Sp3 degradation by ubiquitin.

  14. Biodegradable polydepsipeptides.

    PubMed

    Feng, Yakai; Guo, Jintang

    2009-02-01

    This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials.

  15. Biodegradable Polydepsipeptides

    PubMed Central

    Feng, Yakai; Guo, Jintang

    2009-01-01

    This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials. PMID:19333423

  16. Di-n-octyl phthalate (DOP), a relatively ineffective peroxisome inducing straight chain isomer of the environmental contaminant di(2-ethylhexyl)phthalate (DEHP), enhances the development of putative preneoplastic lesions in rat liver.

    PubMed

    DeAngelo, A B; Garrett, C T; Manolukas, L A; Yario, T

    1986-11-01

    Di-n-octyl phthalate (DOP) is the straight chain isomer of di(2-ethylhexyl) phthalate (DEHP) which is a widely used plasticizer and an environmental contaminant. DEHP is a strong inducer of peroxisome proliferation in rat liver. This is significant since other compounds which are strong inducers of peroxisome proliferation have been reported to be weak carcinogens (Reddy, J.K. and Lalwani, N.D., CRC Crit. Rev. Toxicol., 12 (1983) 1). In contrast to DEHP, DOP causes little or no induction of liver peroxisomes (Mann, A.H. et al., Toxicol. Appl. Pharmacol., 77 (1985) 116, and Gray, T.J.B. et al., Toxicology, 28 (1983) 167). In the current study the ability of 1% DOP to promote the development of putative preneoplastic lesions was evaluated. The effect of feeding 0.5% DEHP as well as equimolar amounts of its 2 major metabolites, mono(2-ethylhexyl)phthalate (MEHP) and 2-ethylhexanol (2-EH) were also investigated. GGT+ foci were initiated in the livers of Sprague--Dawley male rats with a single dose of diethylnitrosamine (DEN) following partial hepatectomy. The control group of rats was fed a semipurified diet (Co) for 10 weeks while the experimental groups received the semipurified diet containing the respective compounds. Induction of peroxisome proliferation was monitored by carnitine acetyltransferase (CAT) levels. DOP treatment resulted in a 6-fold increase in the number of GGT+ foci (20.8 +/- 4.0 vs. 3.5 +/- 1.3; P less than 0.05). This was accompanied by no change in liver weight and only a slight increase in CAT activity when compared with control animals. In contrast to DOP, 2-EH produced essentially no effect with regard to number of foci, peroxisome proliferation or liver weight. DEHP and MEHP induced significant peroxisome proliferation and hepatomegaly but the number of foci were significantly lower than in 2-EH-treated rats. The mechanism for the promoting ability of DOP is not clear but would not appear to be related to peroxisome proliferation. Because of

  17. Facilitated transport of Pd(II) through a supported liquid membrane (SLM) containing N,N,N',N'-tetra-(2-ethylhexyl) thiodiglycolamide T(2EH)TDGA: a novel carrier.

    PubMed

    Ruhela, R; Panja, S; Sharma, J N; Tomar, B S; Tripathi, S C; Hubli, R C; Suri, A K

    2012-08-30

    A novel carrier, N,N,N',N'-tetra-(2-ethylhexyl) thiodiglycolamide, T(2EH)TDGA has been studied for transport of Pd(II) from nitric acid medium across a supported liquid membrane (SLM). Pd(II) was found to be almost quantitatively transported (≈ 99.9%) within 2h from 3.0M HNO(3) medium using 0.05 M T(2EH)TDGA in n-dodecane as carrier and 0.01 M thiourea in 0.2M HNO(3) as strippant. Pd(II) transport was also studied against various parameters like feed acidity, carrier concentration, membrane pore size, etc. Palladium transport was found to be diffusion controlled and the diffusion co-efficient value was found to be 3.56 × 10(-5)cm(2)/s. Selectivity of T(2EH)TDGA for palladium over other fission products was found to be quite high, with the separation factors for Pd, with respect to different fission products being >10(3). With respect to leaching out of carrier from the membrane support, the membrane was found to be stable for six consecutive cycles. Thus, T(2EH)TDGA can be used as an efficient carrier of Pd(II) from nitric acid medium. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Solid-based disperser liquid-liquid microextraction for the preconcentration of phthalate esters and di-(2-ethylhexyl) adipate followed by gas chromatography with flame ionization detection or mass spectrometry.

    PubMed

    Farajzadeh, Mir Ali; Khorram, Parisa; Nabil, Ali Akbar Alizadeh

    2014-05-01

    A new approach for the development of a dispersive liquid-liquid microextraction followed by GC with flame ionization detection was proposed for the determination of phthalate esters and di-(2-ethylhexyl) adipate in aqueous samples. In the proposed method, solid and liquid phases were used as the disperser and extractant, respectively, providing a simple and fast mode for the extraction of the analytes into a small volume of an organic solvent. In this method, microliter levels of an extraction solvent was added onto a sugar cube and it was transferred into the aqueous phase containing the analytes. By manual shaking, the sugar was dissolved and the extractant was released into the aqueous phase as very tiny droplets to provide a cloudy solution. Under optimized conditions, the proposed method showed good precision (RSD less than 5.2%), high enrichment factors (266-556), and low LODs (0.09-0.25 μg/L). The method was successfully applied for the determination of the target analytes in different samples, and good recoveries (71-103%) were achieved for the spiked samples. No need for a disperser solvent and higher enrichment factors compared with conventional dispersive liquid-liquid microextraction and low cost and short sample preparation time are other advantages of the method. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Micro-organic ion-associate phase extraction via in situ fresh phase formation for the preconcentration and determination of di(2-ethylhexyl)phthalate in river water by HPLC.

    PubMed

    Hata, Noriko; Yuwatini, Erini; Ando, Kaori; Yamada, Mika; Kasahara, Issei; Taguchi, Shigeru

    2004-01-01

    A high-enrichment method was proposed for the HPLC determination of trace di(2-ethylhexyl)phthalate (DEHP) in environmental water. A micro-organic ion-associate phase (IAP) was formed in situ from an aqueous sample by adding 4-trifluoromethylanilinium ion and dodecylbenzenesulfonate ions. Centrifugation of the solution led to the isolation of a liquid organic phase containing DEHP at the bottom of the centrifuge tube. The volume of the phase formed was less than 30 microL. DEHP was extracted into the IAP quantitatively during phase formation. After discarding the aqueous phase, the ion associate was dissolved with 50 microL of 2-methoxyethanol, and DEHP in the concentrate was determined by HPLC with an ultra-violet (UV) diode-array detector. DEHP in the concentrations range from 0.8 to 78 microg L(-1) was determined with good precision. The recovery tests for DEHP added to some river water were satisfactory. The detection limit of DEHP, defined as 3-times the standard deviation of the blank signals, was 0.07 microg L(-1) (n = 3). The present method is very simple, and was applied to the determination of DEHP in the river water samples collected around Toyama City, Japan.

  20. Measurements of octanol-air partition coefficients, vapor pressures and vaporization enthalpies of the (E) and (Z) isomers of the 2-ethylhexyl 4-methoxycinnamate as parameters of environmental impact assessment.

    PubMed

    Pegoraro, César N; Chiappero, Malisa S; Montejano, Hernán A

    2015-11-01

    2-Ethylhexyl 4-methoxycinnamate is one of the UVB blocking agents more widely used in a variety of industrial fields. There are more than one hundred industrial suppliers worldwide. Given the enormous annual consumption of octinoxate, problems that arise due to the accumulation of this compound in nature should be taken into consideration. The GC-RT was used in this work with the aim of determining the vapor pressure, enthalpies of vaporization and octanol-air partition coefficient, for the BBP, DOP, E- and Z-EHMC esters. The results showed that Z-EHMC is almost five times more volatile than E-EHMC. Moreover, BBP, Z-EHMC and E-EHMC can be classified as substances with a relatively low mobility since they lie within the range of 810 and log(PL/Pa)<-4, therefore, a low mobility can be expected. From these parameters, their particle-bound fraction and gas-particle partition coefficient were also derived.

  1. Biodegradable thermogels.

    PubMed

    Park, Min Hee; Joo, Min Kyung; Choi, Bo Gyu; Jeong, Byeongmoon

    2012-03-20

    All living creatures respond to external stimuli. Similarly, some polymers undergo conformational changes in response to changes in temperature, pH, magnetic field, electrical field, or the wavelength of light. In one type of stimuli-responsive polymer, thermogel polymers, the polymer aqueous solution undergoes sol-to-gel transition as the temperature increases. Drugs or cells can be mixed into the polymer aqueous solution when it is in its lower viscosity solution state. After injection of the solution into a target site, heating prompts the formation of a hydrogel depot in situ, which can then act as a drug releasing system or a cell growing matrix. In this Account, we describe key materials developed in our laboratory for the construction of biodegradable thermogels. We particularly emphasize recently developed polypeptide-based materials where the secondary structure and nanoassembly play an important role in the determining the material properties. This Account will provide insights for controlling parameters, such as the sol-gel transition temperature, gel modulus, critical gel concentration, and degradability of the polymer, when designing a new thermogel system for a specific biomedical application. By varying the stereochemistry of amino acids in polypeptides, the molecular weight of hydrophobic/hydrophilic blocks, the composition of the polypeptides, the hydrophobic end-capping of the polypeptides, and the microsequences of a block copolymer, we have controlled the thermosensitivity and nanoassembly patterns of the polymers. We have investigated a series of thermogel biodegradable polymers. Polymers such as poly(lactic acid-co-glycolic acid), polycaprolactone, poly(trimethylene carbonate), polycyanoacrylate, sebacic ester, polypeptide were used as hydrophobic blocks, and poly(ethylene glycol) and poly(vinyl pyrrolidone) were used as hydrophilic blocks. To prepare a polymer sensitive to pH and temperature, carboxylic acid or amine groups were introduced

  2. Biodegradable synthetic bone composites

    DOEpatents

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  3. In Utero Growth Restriction and Catch-up Adipogenesis After Developmental Di (2-ethylhexyl) Phthalate (DEHP) Exposure Cause Glucose Intolerance in Adult Male Rats Following a High-fat Dietary Challenge

    PubMed Central

    Strakovsky, Rita S.; Lezmi, Stéphane; Shkoda, Ielyzaveta; Flaws, Jodi A.; Helferich, William G.; Pan, Yuan-Xiang

    2015-01-01

    Phthalates impact adipocyte morphology in vitro, but the sex-specific adipogenic signature immediately after perinatal di(2-ethylhexyl) phthalate (DEHP) exposure and adulthood physiology following a high-fat (HF) dietary challenge are unknown. In the current study, pregnant and lactating dams received DEHP (300 mg/kg body weight) or oil. At weaning (postnatal day (PND) 21), adipose tissue was sampled for real-time PCR. The remaining offspring consumed a control or HF diet. DEHP decreased % fat in males at birth from 13.9%±0.2 to 11.8%±0.6 (mean±SEM), representing a 15.1% decrease in fat by DEHP, and these males caught up in adiposity to controls by PND21. Adult DEHP-exposed males had a 27.5% increase in fat (12.5%±0.9% in controls vs. 15.9%±1.5% in the DEHP group); adipocyte perimeter was increased as well, with fewer small/medium-sized adipocytes, and decreased cell number compared to oil controls. HF diet intake in DEHP-exposed males further increased male energy intake and body weight and led to glucose intolerance. In PND21 males, DEHP increased the expression of adipogenic markers (Pparg1, Cebpa, Adipoq, Ppard, Fabp4, Fasn, Igf1), decreased Lep, and decreased markers of mesenchymal stem cell commitment to the adipogenic lineage (Bmp2, Bmp4, Stat1, Stat5a) compared to oil controls. These data suggest that DEHP may decrease the adipocyte pool at birth, which initially increases adaptive adipocyte maturation and lipid accumulation, but leads to adipose tissue dysfunction in adulthood, decreasing the capacity to adapt to a HF diet, and leading to systemic glucose intolerance. PMID:26188368

  4. Solvent and rotational relaxation of coumarin-153 and coumarin-480 in ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) modified sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (NaAOT) micelle

    NASA Astrophysics Data System (ADS)

    Rao, Vishal Govind; Banerjee, Chiranjib; Mandal, Sarthak; Ghosh, Surajit; Sarkar, Nilmoni

    2013-02-01

    Understanding ion transport dynamics, structure of surfactant aggregates in ionic liquids or ionic liquid/water solutions are quite interesting and potentially important due to widespread applications of surfactant-based systems. In this manuscript we have investigated the effect of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) addition on solvent and rotational relaxation of coumarin-153 (C-153) and coumarin-480 (C-480) in aqueous solution of sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (NaAOT) using steady state and picosecond time resolved fluorescence spectroscopy. The strong adsorption of the bmim+ at the interface and the role of the ionic liquid particularly the cation bmim+ in the modification of the interfacial geometry were probed by the analysis of decay parameters and the rotational relaxation parameters. Since the addition of the NaAOT in water-bmimBF4 mixture above critical micellar concentration (48 mM, obtained from observing pyrene fluorescence) causes strong adsorption of the ionic liquid particularly the cation bmim+, the average solvation time, particularly the slow component increases significantly. More importantly we have found the probe dependent solvation dynamics due to the different location of the probe molecules, C-153 and C-480. C-153 being hydrophobic in nature resides in the stern layer and the adsorption of the bmim+ at the interface modifies stern layer more effectively. So we have observed more pronounced change in solvation dynamics in case of C-153 compared to that in case of C-480. The fluorescence anisotropy decays of the probe molecules were found to be biexponential in nature. The anisotropy decay was interpreted by using a model which consists of the wobbling (rotational) and translational diffusion of the dye coupled with the rotational motion of the micelle as a whole.

  5. Daily Exposure to Di(2-ethylhexyl) Phthalate Alters Estrous Cyclicity and Accelerates Primordial Follicle Recruitment Potentially Via Dysregulation of the Phosphatidylinositol 3-Kinase Signaling Pathway in Adult Mice1

    PubMed Central

    Hannon, Patrick R.; Peretz, Jackye; Flaws, Jodi A.

    2014-01-01

    ABSTRACT Humans are exposed daily to di(2-ethylhexyl) phthalate (DEHP), a plasticizer found in many consumer, medical, and building products containing polyvinyl chloride. Large doses of DEHP disrupt normal ovarian function; however, the effects of DEHP at environmentally relevant levels, the effects of DEHP on folliculogenesis, and the mechanisms by which DEHP disrupts ovarian function are unclear. The present study tested the hypothesis that relatively low levels of DEHP disrupt estrous cyclicity as well as accelerate primordial follicle recruitment by dysregulating phosphatidylinositol 3-kinase (PI3K) signaling. Adult CD-1 mice were orally dosed with DEHP (20 μg/kg/day–750 mg/kg/day) daily for 10 and 30 days. Following dosing, the effects on estrous cyclicity were examined, and follicle numbers were histologically quantified. Further, the ovarian mRNA and protein levels of PI3K signaling factors that are associated with early folliculogenesis were quantified. The data indicate that 10- and 30-day exposure to DEHP prolonged the duration of estrus and accelerated primordial follicle recruitment. Specifically, DEHP exposure decreased the percentage of primordial follicles and increased the percentage of primary follicles counted following 10-day exposure and increased the percentage of primary follicles counted following 30-day exposure. DEHP exposure, at doses that accelerate folliculogenesis, increased the levels of 3-phosphoinositide-dependent protein kinase-1, mammalian target of rapamycin complex 1, and protein kinase B and decreased the levels of phosphatase and tensin homolog, potentially driving PI3K signaling. Collectively, relatively low levels of DEHP disrupt estrous cyclicity and accelerate primordial follicle recruitment potentially via a mechanism involving dysregulation of PI3K signaling. PMID:24804967

  6. Involvement of a chromatin modifier in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell injury: Probably an indirect action via the regulation of NFκB/FasL circuitry

    SciTech Connect

    Chen, Shiwei; Dong, Yushu; Xu, Chun; Jiang, Liming; Chen, Yongjie; Jiang, Cheng; Hou, Wugang; Li, Wei

    2013-11-01

    Highlights: •MTA1 expression is upregulated in SCs upon MEHP treatment. •Knockdown of MTA1 in SCs impairs the MEHP-induced NFκB signaling activation. •Knockdown of MTA1 inhibits recruitment of NFκB onto FasL promoter in MEHP-treated SCs. -- Abstract: The Fas/FasL signaling pathway, controlled by nuclear factor-κB (NFκB) at the transcriptional level, is critical for triggering germ cell apoptosis in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell (SC) injury, but the exact regulation mechanism remain unknown. Here, we discovered that expression level of Metastasis associated protein 1 (MTA1), a component of the Mi-2/nucleosome remodeling and deacetylase complex, was upregulated in SCs during the early recovery after MEHP exposure. This expression change was in line with the dynamic changes in germ cell apoptosis in response to MEHP treatment. Furthermore, a knockdown of MTA1 by RNAi in SCs was found to impair the MEHP-induced early activation of NFκB pathway and abolish the recruitment of NFκB onto FasL promoter, which consequently diminished the MEHP-triggered FasL induction. Considering that Fas/FasL is a well characterized apoptosis initiating signaling during SCs injury, our results point to a potential “switch on” effect of MTA1, which may govern the activation of NFκB/FasL cascade in MEHP-insulted SCs. Overall, the MTA1/NFκB/FasL circuit may serve as an important defensive/repairing mechanism to help to control the germ cell quality after SCs injury.

  7. Towards biodegradable wireless implants.

    PubMed

    Boutry, Clémentine M; Chandrahalim, Hengky; Streit, Patrick; Schinhammer, Michael; Hänzi, Anja C; Hierold, Christofer

    2012-05-28

    A new generation of partially or even fully biodegradable implants is emerging. The idea of using temporary devices is to avoid a second surgery to remove the implant after its period of use, thereby improving considerably the patient's comfort and safety. This paper provides a state-of-the-art overview and an experimental section that describes the key technological challenges for making biodegradable devices. The general considerations for the design and synthesis of biodegradable components are illustrated with radiofrequency-driven resistor-inductor-capacitor (RLC) resonators made of biodegradable metals (Mg, Mg alloy, Fe, Fe alloys) and biodegradable conductive polymer composites (polycaprolactone-polypyrrole, polylactide-polypyrrole). Two concepts for partially/fully biodegradable wireless implants are discussed, the ultimate goal being to obtain a fully biodegradable sensor for in vivo sensing.

  8. [Biodegradation of polyethylene].

    PubMed

    Yang, Jun; Song, Yi-ling; Qin, Xiao-yan

    2007-05-01

    Plastic material is one of the most serious solid wastes pollution. More than 40 million tons of plastics produced each year are discarded into environment. Plastics accumulated in the environment is highly resistant to biodegradation and not be able to take part in substance recycle. To increase the biodegradation efficiency of plastics by different means is the main research direction. This article reviewed the recent research works of polyethylene biodegradation that included the modification and pretreatment of polyethylene, biodegradation pathway, the relevant microbes and enzymes and the changes of physical, chemical and biological properties after biodegradation. The study directions of exploiting the kinds of life-forms of biodegradation polyethylene except the microorganisms, isolating and cloning the key enzymes and gene that could produce active groups, and enhancing the study on polyethylene biodegradation without additive were proposed.

  9. Comparative effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) on the aquatic larvae of Chironomus riparius based on gene expression assays related to the endocrine system, the stress response and ribosomes.

    PubMed

    Planelló, Rosario; Herrero, Oscar; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2011-09-01

    In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analysis of the alterations in gene expression profiles of selected inducible and constitutive genes related to the endocrine system, the cellular stress response and the ribosomal machinery. Fourth instar larvae, a model system in aquatic toxicology, were experimentally exposed to five increasing concentrations (0.01, 0.1, 1, 10, and 100mg/L) of DEHP and BBP for 24h. Gene expression was analysed by the changes in levels of transcripts, using RT-PCR techniques with specific gene probes. The exposures to DEHP or BBP were able to rapidly induce the hsp70 gene in a concentration-dependent manner, whereas the cognate form hsc70 was not altered by either of these chemicals. Transcription of ribosomal RNA as a measure of cell viability, quantified by the levels of ITS2, was not affected by DEHP, but was slightly, yet significantly, downregulated by BBP at the highest concentrations tested. Finally, as these phthalates are classified as endocrine disruptor chemicals (EDCs), their potential effect on the ecdysone endocrine system was studied by analysing the two genes, EcR and usp, of the heterodimeric ecdysone receptor complex. It was found that BBP provoked the overexpression of the EcR gene, with significant increases from exposures of 0.1mg/L and above, while DEHP significantly decreased the activity of this gene at the highest concentration. These data are relevant as they show for the first time the ability of phthalates to interfere with endocrine marker genes in invertebrates, demonstrating their potential capacity to alter the ecdysone signalling pathway. Overall, the study clearly shows a differential gene-toxin interaction

  10. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.C.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-04-01

    We have been able to accomplish the biodegradation of bituminous Illinois No. 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. We report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois No. 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite. 13 refs., 1 fig., 5 tabs.

  11. Biodegradability of plastics.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  12. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  13. Degradation of di(2-ethyl hexyl) phthalate by Fusarium culmorum: Kinetics, enzymatic activities and biodegradation pathway based on quantum chemical modelingpathway based on quantum chemical modeling.

    PubMed

    Ahuactzin-Pérez, Miriam; Tlecuitl-Beristain, Saúl; García-Dávila, Jorge; González-Pérez, Manuel; Gutiérrez-Ruíz, María Concepción; Sánchez, Carmen

    2016-10-01

    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. The specific growth rate (μ), maximum biomass (Xmax), biodegradation constant of DEHP (k), half-life (t1/2) of DEHP biodegradation and removal efficiency of DEHP, esterase and laccase specific activities, and enzymatic yield parameters were evaluated for Fusarium culmorum grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L). The greatest μ and the largest Xmax occurred in media supplemented with 1000mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000mg/L) within 60h of growth. The k and t1/2 were 0.024h(-1) and 28h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500mg/L, respectively. Much higher specific esterase activity than specific laccase activity was observed in all media tested. The compounds of biodegradation of DEHP were identified by GC-MS. A DEHP biodegradation pathway by F. culmorum was proposed on the basis of the intermolecular flow of electrons of the identified intermediate compounds using quantum chemical modeling. DEHP was fully metabolized by F. culmorum with butanediol as the final product. This fungus offers great potential in bioremediation of environments polluted with DEHP. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Biodegradation of plastics.

    PubMed

    Shimao, M

    2001-06-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  15. Grey water biodegradability.

    PubMed

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively.

  16. Renouvellement des eaux du fjord du Saguenay

    NASA Astrophysics Data System (ADS)

    Belzile, Melany

    Le fjord du Saguenay, localise dans la region subarctique de l'est du Canada, ala particularite d' etre connecte a un estuaire tres energetique plutot que directement a 1' ocean. L'embouchure du fjord est situee ala rencontre d'un chenal profond et d'un seuil de 20m de profondeur qui limite les echanges d'eau entre le fjord et l'estuaire du Saint-Laurent. Cependant, les grandes amplitudes de maree a son embouchure ont le potentiel d'entrainer des eaux denses du Saint-Laurent a l'interieur du fjord renouvelant ainsi les eaux des differents bassins. Dans le but d' a voir une meilleure comprehension de la dynamique et de la saisonnalite des renouvellements dans le bassin interne, deux mouillages y ont ete deployes pour recolter les premieres donnees de courant, sur toute la colonne d' eau et sur plusieurs mois, ainsi que des observations de temperature et de salinite a differentes profondeurs. L'un de ces mouillages n' a malheureusement pas pu etre analyse en detail dfi a la complexite de ses resultats et au manque de temps. Des profils ont ete recoltes le long de section transversales (transects), couvrant plusieurs saisons et plusieurs annees, ce qui a contribue a une meilleure comprehension de la distribution spatiale des masses d'eau dans le fjord. Les resultats montrent que ladynamique du fjord est plus complexe que ce qui avait ete precedemment presente dans la litterature. Un changement saisonnier abrupte dans la circulation du fjord a ete observe a la rni-fevrier. De plus, des renouvellements non-anticipes juste en-dessous de la thermohalocline (˜ 10 m de profondeur) ont ete observes entre la fin de 1' hiver et le milieu de 1' ete. En fonction des saisons, trois types de renouvellement peuvent etre observes : renouvellements profonds a l'automne et au debut de l'hiver suivis des renouvellements de sous-surface et enfin les renouvellements a des profondeurs intermediaires pendant l'ete. Le changement saisonnier abrupte observe au milieu de l'hiver ainsi que la

  17. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.A.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-01-01

    Microbial degradation of coals to materials that are soluble in water has been a topic of intensive research for the last few years. The potential for economical recovery of low-grade coals, coupled with possibilities for further upgrading by microbial desulfurization or methanation has spurred intensive research at a number of laboratories. Until very recently, coal biodegradation has been accomplished using low-grade, naturally oxidized coals such as leonardiate, or coals subjected to pretreatment with oxidizing chemicals. The authors have been able to accomplish the biodegradation of bituminous Illinois 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. They report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite.

  18. "Cirque du Freak."

    ERIC Educational Resources Information Center

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  19. "Cirque du Freak."

    ERIC Educational Resources Information Center

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  20. Biodegradability of nonaqueous-phase liquids affects the mineralization of phenanthrene in soil because of microbial competition

    SciTech Connect

    Morrison, D.E.; Alexander, M.

    1997-08-01

    A study was conducted to determine the effects of biodegradability of nonaqueous-phase liquids (NAPLs) and microbial competition on the biodegradation in soil of a constituent of the NAPLs. The rates of mineralization of phenanthrene dissolved in 8 mg of 2,2,4,4,6,8,8-heptamethylnonane (HMN), di(2-ethylhexyl) phthalate (DEHP), or pristane per g of soil were faster than the rates when the compound was dissolved in hexadecane or dodecane. Addition of inorganic N and P to the soil increased the mineralization rate in the first two but not the last two NAPLs. N and P addition did not enhance mineralization of phenanthrene when added in 500 {micro}g of hexadecane, pristane, or HMN per g of soil. Hexadecane was rapidly degraded, pristane was slowly metabolized, DEHP was still slower, and HMN was not mineralized in the test period. Mixing the soil stimulated mineralization of phenanthrene dissolved in HMN but not in hexadecane. Mineralization of phenanthrene dissolved in HMN was the same if the gas phase contained 21%, 2.1%, or traces of O{sub 2}. In contrast, the biodegradation of phenanthrene dissolved in hexadecane, although the same at 21 and 2.1% O{sub 2}, was not observed if traces of O{sub 2} were present. The mineralization was slower in unshaken soil-water mixtures if phenanthrene was added in hexadecane than in HMN or pristane, but the rates with the 3 NAPLs were increased by shaking the suspensions. The authors suggest that the biodegradability of major components of NAPLs and microbial competition for N, P, or O{sub 2} will have a major impact on the rate of transformation of minor constituents of NAPLs.

  1. Molecularly Imprinted Biodegradable Nanoparticles.

    PubMed

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-10

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  2. Molecularly Imprinted Biodegradable Nanoparticles

    NASA Astrophysics Data System (ADS)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  3. Molecularly Imprinted Biodegradable Nanoparticles

    PubMed Central

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization. PMID:28071745

  4. Editorial: Biodegradable Materials

    PubMed Central

    Schaschke, Carl; Audic, Jean-Luc

    2014-01-01

    This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment. PMID:25421242

  5. La naissance du parsec

    NASA Astrophysics Data System (ADS)

    Arenou, F.

    2010-01-01

    Les définitions du parsec et de la magnitude absolue sont le fruit de compromis pour régler trois problèmes entremêlés au début du XXème siècle: quelle unité de distance stellaire adopter? Quel nom lui donner? Comment comparer les luminosités intrinsèques des différentes étoiles?

  6. Phthalates biodegradation in the environment.

    PubMed

    Liang, Da-Wei; Zhang, Tong; Fang, Herbert H P; He, Jianzhong

    2008-08-01

    Phthalates are synthesized in massive amounts to produce various plastics and have become widespread in environments following their release as a result of extensive usage and production. This has been of an environmental concern because phthalates are hepatotoxic, teratogenic, and carcinogenic by nature. Numerous studies indicated that phthalates can be degraded by bacteria and fungi under aerobic, anoxic, and anaerobic conditions. This paper gives a review on the biodegradation of phthalates and includes the following aspects: (1) the relationship between the chemical structure of phthalates and their biodegradability, (2) the biodegradation of phthalates by pure/mixed cultures, (3) the biodegradation of phthalates under various environments, and (4) the biodegradation pathways of phthalates.

  7. Fungal biodegradation of lignocelluloses

    Treesearch

    Annele Hatakka; Kenneth E. Hammel

    2010-01-01

    Uncertainties in the basic structures of especially lignin but also other components in lignocellulose make fungal biodegradation studies a challenging task. The following properties are important in terms of microbial or enzymatic attack: (1) lignin polymers have compact structures that are insoluble in water and difficult to penetrate by microbes or enzymes, (2) the...

  8. Biodegradable Sonobuoy Decelerators

    DTIC Science & Technology

    2015-06-01

    material. Two materials studied were polyvinyl alcohol (PVOH) and polyhydroxyalkanoate (PHA). Single and multilayered PVOH films were evaluated as well...readiness point for technology transition. 15. SUBJECT TERMS biodegrade, decelerator, sonobuoy, polyvinyl alcohol , polyhydroxyalkanoate, marine...Association PVOH polyvinyl alcohol SPAWARS Space and Naval Warfare Systems Command VIMS Virginia Institute of Marine Science VOC volatile organic

  9. Systemic approaches to biodegradation.

    PubMed

    Trigo, Almudena; Valencia, Alfonso; Cases, Ildefonso

    2009-01-01

    Biodegradation, the ability of microorganisms to remove complex chemicals from the environment, is a multifaceted process in which many biotic and abiotic factors are implicated. The recent accumulation of knowledge about the biochemistry and genetics of the biodegradation process, and its categorization and formalization in structured databases, has recently opened the door to systems biology approaches, where the interactions of the involved parts are the main subject of study, and the system is analysed as a whole. The global analysis of the biodegradation metabolic network is beginning to produce knowledge about its structure, behaviour and evolution, such as its free-scale structure or its intrinsic robustness. Moreover, these approaches are also developing into useful tools such as predictors for compounds' degradability or the assisted design of artificial pathways. However, it is the environmental application of high-throughput technologies from the genomics, metagenomics, proteomics and metabolomics that harbours the most promising opportunities to understand the biodegradation process, and at the same time poses tremendous challenges from the data management and data mining point of view.

  10. Fully biodegradable septal defect occluder-a double umbrella design.

    PubMed

    Duong-Hong, Duc; Tang, Yong-Dan; Wu, Wei; Venkatraman, Subbu S; Boey, Freddy; Lim, James; Yip, James

    2010-11-01

    Current percutaneous devices for septal defect treatment are made of nondegradable metallic and synthetic fabric materials. These devices are not ideal due to risks of future complications from device erosions and potential obstructed access for future transseptal procedures. The biodegradable double umbrella device was made of fully biodegradable polymers, featured with two discs connected with a stretchable stem. The devices were inserted across the PFO model created on Yorkshire swines through a short sheath by open thoracotomy. Fluoroscopic imaging and echocardiography obtained during the 1-month follow-up study period showed that the devices were in stable position with no shunt. The in-vitro degradation study and post-mortem explantation confirmed that the devices have good integrity and mechanical strength during the 1-month trial. Furthermore, the devices appeared to be well endothelialized after 1 month. These results showed clearly that it is feasible to replace the current nondegradable devices with the new generation biodegradable PFO occluders. This work studied and proved the feasibility of interventional closure of patent foramen ovale (PFO) with a fully biodegradable device, that we call the "double umbrella" (DU) for its symbolic design. © 2010 Wiley-Liss, Inc.

  11. Biodegradation of Cyanuric Acid

    PubMed Central

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  12. Biodegradable mesostructured polymer membranes

    PubMed Central

    Tian, Bozhi; Shankarappa, Sahadev; Chang, Homer H.; Tong, Rong; Kohane, Daniel S.

    2013-01-01

    The extracellular matrix (ECM) has a quasi-ordered reticular mesostructure with feature sizes on the order of tenths of to a few hundred nanometers. Approaches to preparing biodegradable synthetic scaffolds for engineered tissues that have the critical mesostructure to mimic ECM are few. Here we present a simple and general solvent evaporation-induced self-assembly (EISA) approach to preparing concentrically reticular mesostructured polyol-polyester membranes. The mesostructures were formed by a novel self-assembly process without covalent or electrostatic interactions, which yielded feature sizes matching those of ECM. The mesostructured materials were nonionic, hydrophilic, and water-permeable, and could be shaped into arbitrary geometries such as conformally-molded tubular sacs and micropatterned meshes. Importantly, the mesostructured polymers were biodegradable, and were used as ultrathin temporary substrates for engineering vascular tissue constructs. PMID:23964960

  13. Biodegradable mesostructured polymer membranes.

    PubMed

    Tian, Bozhi; Shankarappa, Sahadev A; Chang, Homer H; Tong, Rong; Kohane, Daniel S

    2013-09-11

    The extracellular matrix (ECM) has a quasi-ordered reticular mesostructure with feature sizes on the order of tenths of to a few hundred nanometers. Approaches to preparing biodegradable synthetic scaffolds for engineered tissues that have the critical mesostructure to mimic ECM are few. Here we present a simple and general solvent evaporation-induced self-assembly (EISA) approach to preparing concentrically reticular mesostructured polyol-polyester membranes. The mesostructures were formed by a novel self-assembly process without covalent or electrostatic interactions, which yielded feature sizes matching those of ECM. The mesostructured materials were nonionic, hydrophilic, and water-permeable and could be shaped into arbitrary geometries such as conformally molded tubular sacs and micropatterned meshes. Importantly, the mesostructured polymers were biodegradable and were used as ultrathin temporary substrates for engineering vascular tissue constructs.

  14. Safe biodegradable fluorescent particles

    DOEpatents

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  15. Biodegradable Ureteral Stents

    NASA Astrophysics Data System (ADS)

    Chew, Ben H.; Hadaschik, Boris A.; Paterson, Ryan F.; Lange, Dirk

    2008-09-01

    Ureteral stents have been associated with painful symptoms and require a secondary procedure for removal if the suture tether is removed. Biodegradable stents have been attempted in the past, but are no longer used since they resulted in histological inflammation or unpredictable variability in degradation time. This article reviews past degradable materials used in both the prostatic urethra and ureter as well as identifies a new degradable ureteral stent that lasts between 2 to 4 weeks in a porcine model.

  16. Integration of bioinformatics to biodegradation

    PubMed Central

    2014-01-01

    Bioinformatics and biodegradation are two primary scientific fields in applied microbiology and biotechnology. The present review describes development of various bioinformatics tools that may be applied in the field of biodegradation. Several databases, including the University of Minnesota Biocatalysis/Biodegradation database (UM-BBD), a database of biodegradative oxygenases (OxDBase), Biodegradation Network-Molecular Biology Database (Bionemo) MetaCyc, and BioCyc have been developed to enable access to information related to biochemistry and genetics of microbial degradation. In addition, several bioinformatics tools for predicting toxicity and biodegradation of chemicals have been developed. Furthermore, the whole genomes of several potential degrading bacteria have been sequenced and annotated using bioinformatics tools. PMID:24808763

  17. Biodegradable Polymers for the Environment

    NASA Astrophysics Data System (ADS)

    Gross, Richard A.; Kalra, Bhanu

    2002-08-01

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  18. Biodegradable polymers for the environment.

    PubMed

    Gross, Richard A; Kalra, Bhanu

    2002-08-02

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  19. A model for simultaneous crystallisation and biodegradation of biodegradable polymers.

    PubMed

    Han, Xiaoxiao; Pan, Jingzhe

    2009-01-01

    This paper completes the model of biodegradation for biodegradable polymers that was previously developed by Wang et al. (Wang Y, Pan J, Han X, Sinka, Ding L. A phenomenological model for the degradation of biodegradable polymers. Biomaterials 2008;29:3393-401). Crystallisation during biodegradation was not considered in the previous work which is the topic of the current paper. For many commonly used biodegradable polymers, there is a strong interplay between crystallisation and hydrolysis reaction during biodegradation - the chain cleavage caused by the hydrolysis reaction provides an extra mobility for the polymer chains to crystallise and the resulting crystalline phase becomes more resistant to further hydrolysis reaction. This paper presents a complete theory to describe this interplay. The fundamental equations in the Avrami's theory for crystallisation are modified and coupled to the diffusion-reaction equations that were developed in our previous work. The mathematical equations are then applied to three biodegradable polymers for which long term degradation data are available in the literature. It is shown that the model can capture the behavior of the major biodegradable polymers very well.

  20. Biodegradation of perfluorinated compounds.

    PubMed

    Parsons, John R; Sáez, Monica; Dolfing, Jan; de Voogt, Pim

    2008-01-01

    The information available in the literature provides evidence for the biodegradation of some poly- and per-fluorinated compounds, but such biodegradation is incomplete and may not result in mineralization. Recent publications have demonstrated that 8:2 fluorotelomer alcohol, for example, can be degraded by bacteria from soil and wastewater treatment plants to perfluorooctanoic acid. Similarly, 2-N-ethyl(perfluorooctane sulfonamido)ethanol can be degraded by wastewater treatment sludge to perfluorooctanesulfonate. It is presently unclear whether these two products are degraded further. Therefore, the question remains as to whether there is a potential for defluorination and biodegradation of PFCs that contributes significantly to their environmental fate. The lack of mineralization observed is probably caused by the stability of the C-F bond, although there are examples of microbially catalyzed defluorination reactions. As is the case with reductive dechlorination or debromination, reductive defluorination is energetically favorable under anaerobic conditions and releases more energy than that available from sulfate reduction or methanogenesis. Consequently, we should consider the possibility that bacteria will adapt to utilize this source of energy, although evolving mechanisms to overcome the kinetic barriers to degradation of these compounds may take some time. The fact that such reactions are absent for some PFCs, to date, may be because too little time has passed for microorganisms to adapt to these potential substrates. Hence, the situation may be comparable to that of chlorinated organic compounds several decades ago. For many years, organochlorine compounds were considered to be catabolically recalcitrant; today, reductive chlorination reactions of many organochlorines, including PCBs and dioxins, are regularly observed in anaerobic environments. Hence, it is opportune and important to continue studying the potential degradation of perfluorinated compounds

  1. Computational Framework for Predictive Biodegradation

    PubMed Central

    Finley, Stacey D.; Broadbelt, Linda J.

    2014-01-01

    As increasing amounts of anthropogenic chemicals are released into the environment, it is vital to human health and the preservation of ecosystems to evaluate the fate of these chemicals in the environment. It is useful to predict whether a particular compound is biodegradable and if alternate routes can be engineered for compounds already known to be biodegradable. In this work, we describe a computational framework (called BNICE) that can be used for the prediction of novel biodegradation pathways of xenobiotics. The framework was applied to 4-chlorobiphenyl, phenanthrene, γ-hexachlorocyclohexane, and 1,2,4-trichlorobenzene, compounds representing various classes of xenobiotics with known biodegradation routes. BNICE reproduced the proposed biodegradation routes found experimentally, and in addition, it expanded the biodegradation reaction networks through the generation of novel compounds and reactions. The novel reactions involved in the biodegradation of 1,2,4-trichlorobenzene were studied in depth, where pathway and thermodynamic analyses were performed. This work demonstrates that BNICE can be applied to generate novel pathways to degrade xenobiotic compounds that are thermodynamically feasible alternatives to known biodegradation routes and attractive targets for metabolic engineering. PMID:19650084

  2. Microbial biosurfactants and biodegradation.

    PubMed

    Ward, Owen P

    2010-01-01

    Microbial biosurfactants are amphipathic molecules having typical molecular weights of 500-1500 Da, made up of peptides, saccharides or lipids or their combinations. In biodegradation processes they mediate solubilisation, mobilization and/or accession of hydrophobic substrates to microbes. They may be located on the cell surface or be secreted into the extracellular medium and they facilitate uptake of hydrophobic molecules through direct cellular contact with hydrophobic solids or droplets or through micellarisation. They are also involved in cell physiological processes such as biofilm formation and detachment, and in diverse biofilm associated processes such as wastewater treatment and microbial pathogenesis. The protection of contaminants in biosurfactants micelles may also inhibit uptake of contaminants by microbes. In bioremediation processes biosurfactants may facilitate release of contaminants from soil, but soils also tend to bind surfactants strongly which makes their role in contaminant desorption more complex. A greater understanding of the underlying roles played by biosurfactants in microbial physiology and in biodegradative processes is developing through advances in cell and molecular biology.

  3. Marine Oil Biodegradation.

    PubMed

    Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

    2016-03-01

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  4. Marine Oil Biodegradation

    SciTech Connect

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  5. Marine Oil Biodegradation

    DOE PAGES

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine watersmore » with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.« less

  6. Biodegradation of crude oils.

    PubMed

    Bosecker, K; Teschner, M; Wehner, H

    1989-01-01

    Petroleum from well sites in the Gifhorn Trough (Lower Saxony, NW-Germany) and the Maracaibo Basin (Venezuela) contained various types of microorganisms capable of degrading crude oils. Genetically related oils were inoculated with the isolated microorganisms and the degradation of the oils was followed by chromatographic techniques. Parameters important for the reactions (pH, supply of oxygen, nitrogen and phosphorus, reaction medium) were monitored and optimized. The degradation of n-alkanes was followed closely. Microorganisms active in degradation (yeast, bacteria) easily survived a period of inactivity due to missing nutrients and were reactivated within hours to degrade newly added crude oil. Under substrate-limiting conditions selectivity of degradation was found, destroying medium-chain n-alkanes (C20, C21) at a faster rate than long-chain n-alkanes (C30, C31). During degradation the physical parameters of the crude oils (e.g. density, viscosity, average molecular weight) were altered and shifted into the direction of heavy oil. In vitro degraded oil is very similar to oil degraded in nature. Aromatic hydrocarbons and biomarker molecules (steranes and triterpanes) were not degraded under the conditions used. Pyrolysis-GC analysis of asphaltenes revealed no significant changes in the composition of pyrolyzates during biodegradation. There is sufficient evidence that heavy oils - besides some other effects - are generated by the in situ-biodegradation of conventional oils.

  7. Preparation of a biodegradable oil absorber and its biodegradation.

    PubMed

    Yoo, Su-Yong; Daud, Wan Mohd Ashri Wan; Lee, Min-Gyu

    2012-01-01

    The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%.

  8. Biodegradation of Polypropylene Nonwovens

    NASA Astrophysics Data System (ADS)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  9. Biodegradable plastics from renewable sources.

    PubMed

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  10. Biodegradation of propellant ingredients

    SciTech Connect

    Zhang, Y.Z.; Sundaram, S.T.; Sharma, A.

    1995-12-31

    This paper summarizes efforts to degrade nitrocellulose (NC) and nitroglycerin (NG) with fungi. Screening experiments were performed to determine the ability of mycelial fungi to biodegrade NC. The greatest amount of NC degradation was obtained with Sclerotium rolfsii ATCC 24459 and Fusarium solani IFO 31093. These fungi were then tested for NG degradation. It was found that the combined culture aerobically degraded 100% of the NG to form a mixture of 55% dinitroglycerin (DNG) and 5% of mononitroglycerin (MNG) in two days, with no further change observed afterward. In the presence of 1.2% glucose and 0.05% ammonium nitrate, NG was completely degraded in two days and a mixture of 20% DNG and 16% MNG was formed after 11 days. Based on these results, it appears that the combination of the fungi in a one to one ratio can be used to degrade both of these energetic compounds.

  11. Biodegradation of biodiesel fuels

    SciTech Connect

    Zhang, X.; Haws, R.; Wright, B.; Reese, D.; Moeller, G.; Peterson, C.

    1995-12-31

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO{sub 2} evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO{sub 2} evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO{sub 2} evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO{sub 2}. The test substances were examined for BOD{sub 5} and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD{sub 5} and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD{sub 5} and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p << 0.01. RME was also significantly lower than REE (p < 0.05) and MS (p < 0.01) for BOD{sub 5} value.

  12. Taking advantage of natural biodegradation

    SciTech Connect

    Butler, W.A.; Bartlett, C.L.

    1995-12-31

    A chemical manufacturing facility in central New Jersey evaluated alternatives to address low levels of volatile organic compounds (VOCs) in groundwater. Significant natural attenuation of VOCs was observed in groundwater, and is believed to be the result of natural biodegradation, commonly referred to as intrinsic bioremediation. A study consisting of groundwater sampling and analysis, field monitoring, and transport modeling was conducted to evaluate and confirm this phenomenon. The primary conclusion that can be drawn from the study is that observed natural attenuation of VOCs in groundwater is due to natural biodegradation. Based on the concept that natural biodegradation will minimize contaminant migration, bioventing has been implemented to remove the vadose-zone source of VOCs to groundwater. Taking advantage of natural biodegradation has resulted in significant cost savings compared to implementing a conventional groundwater pump-and-treat system, while still protecting human health and the environment.

  13. Biodegradable Peptide-Silica Nanodonuts.

    PubMed

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-07

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated.

  14. Biodegradation of nitroaromatic compounds.

    PubMed

    Spain, J C

    1995-01-01

    Nitroaromatic compounds are released into the biosphere almost exclusively from anthropogenic sources. Some compounds are produced by incomplete combustion of fossil fuels; others are used as synthetic intermediates, dyes, pesticides, and explosives. Recent research revealed a number of microbial systems capable of transforming or biodegrading nitroaromatic compounds. Anaerobic bacteria can reduce the nitro group via nitroso and hydroxylamino intermediates to the corresponding amines. Isolates of Desulfovibrio spp. can use nitroaromatic compounds as their source of nitrogen. They can also reduce 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene. Several strains of Clostridium can catalyze a similar reduction and also seem to be able to degrade the molecule to small aliphatic acids. Anaerobic systems have been demonstrated to destroy munitions and pesticides in soil. Fungi can extensively degrade or mineralize a variety of nitroaromatic compounds. For example, Phanerochaete chrysosporium mineralizes 2,4-dinitrotoluene and 2,4,6-trinitrotoluene and shows promise as the basis for bioremediation strategies. The anaerobic bacteria and the fungi mentioned above mostly transform nitroaromatic compounds via fortuitous reactions. In contrast, a number of nitroaromatic compounds can serve as growth substrates for aerobic bacteria. Removal or productive metabolism of nitro groups can be accomplished by four different strategies. (a) Some bacteria can reduce the aromatic ring of dinitro and trinitro compounds by the addition of a hydride ion to form a hydride-Meisenheimer complex, which subsequently rearomatizes with the elimination of nitrite. (b) Monooxygenase enzymes can add a single oxygen atom and eliminate the nitro group from nitrophenols. (c) Dioxygenase enzymes can insert two hydroxyl groups into the aromatic ring and precipitate the spontaneous elimination of the nitro group from a variety of nitroaromatic compounds. (d) Reduction of the nitro group to the corresponding

  15. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ... them. Potentially affected entities may include: Crop production (NAICS code 111). Animal production... integral part of its composition the atomic elements carbon, hydrogen, and oxygen. 3. The polymer does not...

  16. Synthesis and physical properties of coriander estolide 2-ethylhexyl esters

    USDA-ARS?s Scientific Manuscript database

    Coriander (Coriandrum sativum L.) is new crop that is currently being investigated for cultivation in Central Illinois by USDA-NCAUR. Coriander is an annual herb belonging to the Apiaceae (Umbelliferae) family and indigenous to the Mediterranean basin areas and the Near East. This plant is widely ...

  17. Biodegradation of Polyethoxylated Nonylphenols

    PubMed Central

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEOx), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEOx and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO15, as unique carbon source, is described. The most efficient NPEO15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO15 medium. The NPEO15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively. PMID:23936727

  18. Biodegradation of sorbed chemicals in soil

    SciTech Connect

    Scow, K.M.; Fan, S.; Johnson, C.; Ma, G.M.

    1995-06-01

    Rates of biodegradation of sorbed chemicals are usually lower in soil than in aqueous systems, in part because sorption reduces the availability of the chemical to microorganisms. Biodegradation, sorption, and diffusion occur simultaneously and are tightly coupled. In soil, the rate of biodegradation is a function of a chemical`s diffusion coefficient, sorption partition coefficient, the distance it must diffuse from the site of sorption to microbial populations that can degrade it, and its biodegradation rate constant. A model (DSB model) was developed that describes biodegradation of chemicals limited in the availability by sorption and diffusion. Different kinetics expressions describe biodegradation depending on whether the reaction is controlled by mass transfer (diffusion and sorption) or the intrinsic biodegradation rate, and whether biodegradation begins during or after the majority of sorption has occurred. We tested the hypothesis that there is a direct relationship between how strongly a chemical is sorbed and the chemical`s biodegradation rate. In six soils with different organic carbon contents, there was no relationship between the extent or rate of biodegradation and the sorption partition coefficient for phenanthrene. Aging of phenanthrene residues in soil led to a substantial reduction in the rate of biodegradation compared to biodegradation rates of recently added phenanthrene. Considerable research has focused on identification and development of techniques for enhancing in situ biodegradation of sorbed chemicals. Development of such techniques, especially those involving inoculation with microbial strains, should consider physical mass transfer limitations and potential decreases in bioavailability over time. 4 refs., 3 figs., 1 tab.

  19. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    NASA Astrophysics Data System (ADS)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  20. Developments in metallic biodegradable stents.

    PubMed

    Hermawan, H; Dubé, D; Mantovani, D

    2010-05-01

    Interest in metallic degradable biomaterials research has been growing in the last decade. Both scientific journals and patent databases record a high increase in publications in this area. Biomedical implants with temporary function, such as coronary stents, are the targeted applications for this novel class of biomaterials. It is expected that stents made of degradable biomaterials, named biodegradable stents, will provide a temporary opening into a narrowed arterial vessel until the vessel remodels and will progressively disappear thereafter. Biodegradable stents made of metal have recently been progressed into preclinical tests in humans after their first introduction in early 2000s. By referring to patents and journal publications, this paper reviews the developments in biodegradable stents, with emphasis on those made of metals, starting from the first design ideas to validation testing.

  1. Petroleum biodegradation in marine environments.

    PubMed

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  2. A procedure for the joint evaluation of substrate partitioning and kinetic parameters for reactions catalyzed by enzymes in reverse micellar solutions. I. Hydrolysis of 2-naphthyl acetate catalyzed by lipase in sodium 1,4-bis(2-ethylhexyl) sulphosuccinate (AOT)/buffer/heptane.

    PubMed

    Aguilar, L F; Abuin, E; Lissi, E

    2001-04-15

    A simple method useful for the joint evaluation of substrate partitioning and kinetic parameters for reactions catalyzed by enzymes entrapped in reverse micelles is proposed. The method is applied to the hydrolysis of 2-naphthyl acetate (2-NA) catalyzed by lipase in sodium 1,4-bis(2-ethylhexyl) sulfosuccinate (AOT)/buffer/heptane reverse micellar solutions. In the presence of micelles, the relationship between the initial reaction rate and the analytical concentration of 2-NA was dependent on AOT concentration at a constant W ([water]/[AOT]) value. The dependence of the initial reaction rate profiles with [AOT] was analyzed according with the method proposed to obtain the partition constant of 2-NA between the micelles and the external solvent, Kp. A value of Kp = 2.7 L mol(-1) was obtained irrespective of the water content of the micelles (W from 5 to 20). The catalytic rate constant kcat in the micellar solutions was independent of [AOT] but slightly decreased with an increase in W from 2 x 10(-6) mol g(-1) s(-1) at W = 5 to 1.2 x 10(-6) mol g(-1) s(-1) at W = 20. The apparent Michaelis constant determined in terms of the analytical concentration of 2-NA increased with [AOT] at a given W and moderately decreased with W at a fixed [AOT]. The increase with [AOT] is accounted for by considering the partitioning of the substrate. After correction for the partitioning of 2-NA values of (Km)corr were obtained as 3.9 x 10(-3) mol L(-1) (W = 5), 4.6 x 10(-3) mol L(-1) (W = 10), 2.3 x 10(-3) mol L(-1) (W = 15), and 1.7 x 10(-3) mol L(-1) (W = 20). The rate parameters in the aqueous phase in the absence of micelles, were obtained as (kcat)aq = 7.9 x 10(-6) mol g(-1) s(-1) and (Km)aq = 2.5 x 10(-3) mol L(-1). In order to compare the efficiency of the enzyme in the micellar solution with that in aqueous phase, the values of (Km)corr were in turn corrected to take into account differences in the substrate activity, obtaining so a set of (Km)*corr values. The efficiency of the

  3. Biodegradable Pectin/clay Aerogels

    USDA-ARS?s Scientific Manuscript database

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  4. Concomitant aerobic biodegradation of benzene and thiophene

    SciTech Connect

    Dyreborg, S.; Arvin, E.; Broholm, K.

    1998-05-01

    The concomitant aerobic biodegradation of benzene and thiophene was investigated in microcosm experiments using a groundwater enrichment culture. Benzene was biodegraded within 1 d, whereas thiophene could not be biodegraded as the sole source of carbon and energy. Some interesting phenomena were observed when both benzene and thiophene were present. In most cases, removal of thiophene was observed, and the removal occurred concomitantly with the biodegradation of benzene, suggesting that benzene was used as a primary substrate in the cometabolic biodegradation of thiophene. No biodegradation of the two compounds was observed for some combinations of concentrations, suggesting that thiophene could act as an inhibitor to benzene biodegradation. However, this effect could be overcome if more benzene was added to the microcosm. Residual concentrations of benzene and thiophene were observed in some microcosms and the data indicated that the biodegradation of the two compounds stopped when a critical threshold ratio between the concentrations of thiophene and benzene was reached. This ratio varied between 10 and 20. Results from modeling the biodegradation data suggested that thiophene was cometabolized concomitantly with the biodegradation of benzene and that the biodegradation may be described by a modified model based on a traditional model with an inhibition term incorporated.

  5. Phthalate esters in the environment: A critical review of their occurrence, biodegradation, and removal during wastewater treatment processes.

    PubMed

    Gao, Da-Wen; Wen, Zhi-Dan

    2016-01-15

    Phthalate esters are one of the most frequently detected persistent organic pollutants in the environment. A better understanding of their occurrence and degradation in the environment and during wastewater treatment processes will facilitate the development of strategies to reduce these pollutants and to bioremediate contaminated freshwater and soil. Phthalate esters occur at measurable levels in different environments worldwide. For example, the concentrations of dimethyl phthalate (DMP) in atmospheric particulate matter, fresh water and sediments, soil, and landfills are N.D.-10.4 ng/m(3), N.D.-31.7 μg/L, N.D.-316 μg/kg dry weight, and N.D.-200 μg/kg dry weight, N.D.-43.27 μg/L, respectively. Bis(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are primary phthalate ester pollutants. Urbanization has increased the discharge of phthalate esters to atmospheric and aquatic environments, and the use of agricultural plastics has exacerbated soil contamination by phthalate esters in rural areas. Aerobic biodegradation is the primary manner of phthalate ester mineralization in the environment, and this process has been widely studied. Phthalate esters can be removed during wastewater treatment processes. The combination of different wastewater treatment technologies showed greater efficiency in the removal of phthalate esters than individual treatment steps, such as the combination of anaerobic wastewater treatment with a membrane bioreactor would increase the efficiency of phthalate ester removal from 65%-71% to 95%-97%. This review provides a useful framework to identify future research objectives to achieve the mineralization and elimination of phthalate esters in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Cri du Chat syndrome

    PubMed Central

    Cerruti Mainardi, Paola

    2006-01-01

    The Cri du Chat syndrome (CdCS) is a genetic disease resulting from a deletion of variable size occurring on the short arm of chromosome 5 (5p-). The incidence ranges from 1:15,000 to 1:50,000 live-born infants. The main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds, micrognathia, abnormal dermatoglyphics, and severe psychomotor and mental retardation. Malformations, although not very frequent, may be present: cardiac, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism. Molecular cytogenetic analysis has allowed a cytogenetic and phenotypic map of 5p to be defined, even if results from the studies reported up to now are not completely in agreement. Genotype-phenotype correlation studies showed a clinical and cytogenetic variability. The identification of phenotypic subsets associated with a specific size and type of deletion is of diagnostic and prognostic relevance. Specific growth and psychomotor development charts have been established. Two genes, Semaphorin F (SEMAF) and δ-catenin (CTNND2), which have been mapped to the "critical regions", are potentially involved in cerebral development and their deletion may be associated with mental retardation in CdCS patients. Deletion of the telomerase reverse transcriptase (hTERT) gene, localised to 5p15.33, could contribute to the phenotypic changes in CdCS. The critical regions were recently refined by using array comparative genomic hybridisation. The cat-like cry critical region was further narrowed using quantitative polymerase chain reaction (PCR) and three candidate genes were characterised in this region. The diagnosis is based on typical clinical manifestations. Karyotype analysis and, in doubtful cases, FISH analysis will confirm the diagnosis. There is no specific therapy for CdCS but early rehabilitative and educational interventions improve the prognosis and considerable progress has been made in

  7. Cri du Chat syndrome.

    PubMed

    Cerruti Mainardi, Paola

    2006-09-05

    The Cri du Chat syndrome (CdCS) is a genetic disease resulting from a deletion of variable size occurring on the short arm of chromosome 5 (5p-). The incidence ranges from 1:15,000 to 1:50,000 live-born infants. The main clinical features are a high-pitched monochromatic cry, microcephaly, broad nasal bridge, epicanthal folds, micrognathia, abnormal dermatoglyphics, and severe psychomotor and mental retardation. Malformations, although not very frequent, may be present: cardiac, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism. Molecular cytogenetic analysis has allowed a cytogenetic and phenotypic map of 5p to be defined, even if results from the studies reported up to now are not completely in agreement. Genotype-phenotype correlation studies showed a clinical and cytogenetic variability. The identification of phenotypic subsets associated with a specific size and type of deletion is of diagnostic and prognostic relevance. Specific growth and psychomotor development charts have been established. Two genes, Semaphorin F (SEMAF) and delta-catenin (CTNND2), which have been mapped to the "critical regions", are potentially involved in cerebral development and their deletion may be associated with mental retardation in CdCS patients. Deletion of the telomerase reverse transcriptase (hTERT) gene, localised to 5p15.33, could contribute to the phenotypic changes in CdCS. The critical regions were recently refined by using array comparative genomic hybridisation. The cat-like cry critical region was further narrowed using quantitative polymerase chain reaction (PCR) and three candidate genes were characterised in this region. The diagnosis is based on typical clinical manifestations. Karyotype analysis and, in doubtful cases, FISH analysis will confirm the diagnosis. There is no specific therapy for CdCS but early rehabilitative and educational interventions improve the prognosis and considerable progress has been made

  8. Applications attract DuPont

    SciTech Connect

    Rotman, D.

    1996-08-07

    Scientists at DuPont say they have demonstrated the first chemical processing application for high-temperature superconducting (HTS) magnets. DuPont says the work, which uses a HTS magnet to separate mineral contaminants from kaolin, points to the feasibility of a range of HTS applications in industrial processing, including those involving polymerization. DuPont`s success comes after 10 years of work to commercialize high-temperature superconductors. And while superconductors have lost much of their luster since the late 1980s, the company says it is still bullish on their prospects. {open_quotes}At the moment, there`s no real market for superconductors,{close_quotes} says Alan Lauder, general manager/superconductivity. But, he says, several potentially lucrative applications could be commercialized within the next several years.

  9. Biobased and biodegradable polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  10. L'Aventure du LHC

    SciTech Connect

    2010-06-11

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  11. DuPont hikes butanediol

    SciTech Connect

    Morris, G.D.L.

    1997-05-14

    Butanediol (BDO) and its derivatives continue to be strong, a positive sign for the many companies planning expansions. DuPont - one of only two global producers not planning capacity additions - has announced that it will discontinue all off-schedule pricing for BDO and two important derivatives, tetrahydrofuran (THF) and polytetramethylene ether glycol (PTMEG). DuPont`s list prices are $1.00/lb fob for BDO, about $1.40/lb for THF, and $2.00/lb for PTMEG. The price adjustment is effective this month or as contracts allow.

  12. Recent advances in biodegradable nanocomposites.

    PubMed

    Pandey, Jitendra K; Kumar, A Pratheep; Misra, Manjusri; Mohanty, Amar K; Drzal, Lawrence T; Singh, Raj Pal

    2005-04-01

    There is growing interest in developing bio-based products and innovative process technologies that can reduce the dependence on fossil fuel and move to a sustainable materials basis. Biodegradable bio-based nanocomposites are the next generation of materials for the future. Renewable resource-based biodegradable polymers including cellulosic plastic (plastic made from wood), corn-derived plastics, and polyhydroxyalkanoates (plastics made from bacterial sources) are some of the potential biopolymers which, in combination with nanoclay reinforcement, can produce nanocomposites for a variety of applications. Nanocomposites of this category are expected to possess improved strength and stiffness with little sacrifice of toughness, reduced gas/water vapor permeability, a lower coefficient of thermal expansion, and an increased heat deflection temperature, opening an opportunity for the use of new, high performance, lightweight green nanocomposite materials to replace conventional petroleum-based composites. The present review addresses this green material, including its technical difficulties and their solutions.

  13. Poumon du puisatier

    PubMed Central

    Elidrissi, Amal Moustarhfir; Zaghba, Nahid; Benjelloun, Hanane; Yassine, Najiba

    2016-01-01

    Le puisatier a pour profession le creusement et l'entretien des puits pour fournir de l'eau. Il est au contact de divers minerais, particulièrement la silice, particule qui présente un risque certain de développement des maladies pulmonaires connues sous le nom de silicose. Le but de notre travail est de préciser le profil épidémiologique, clinique, radiologique et évolutif des patients puisatiers silicotiques. C'est une étude rétrospective concernant 54 cas de puisatiers ayant une silicose, colligés au service des maladies respiratoires du CHU Ibn Rochd de Casablanca, de Mars 1997 à Janvier 2016. Tous les malades étaient des puisatiers, de sexe masculin, avec une moyenne d'âge de 50 ans. Le tabagisme était retrouvé dans 36 cas et un antécédent de tuberculose était noté dans huit cas. La radiographie thoracique retrouvait des grandes opacités dans 39 cas, des petites opacités dans 15 cas, et un épaississement des septats dans 11 cas. Ce tableau de silicose s'était compliqué d'une surinfection bactérienne dans 37% des cas, d' un pneumothorax dans 4% des cas et d'une tuberculose dans 20% des cas. La prise en charge thérapeutique était celle des complications. La déclaration de la maladie professionnelle et de l'indemnisation était faite. L'évolution était bonne dans 12 cas, stationnaire dans 17 cas et mauvaise dans 16 cas. La silicose est une pneumoconiose fréquente chez les puisatiers. Elle retentit sur la fonction respiratoire. Nous soulignons l'association fréquente de tuberculose et nous insistons sur la prévention qui reste le meilleur traitement. PMID:28292119

  14. Aerobic biodegradation of selected monoterpenes.

    PubMed

    Misra, G; Pavlostathis, S G; Perdue, E M; Araujo, R

    1996-07-01

    Batch experiments were conducted to assess the biotransformation potential of four hydrocarbon monoterpenes (d-limonene, alpha-pinene, gamma-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and alpha-terpineol) under aerobic conditions at 23 degrees C. Both forest-soil extract and enriched cultures were used as inocula for the biodegradation experiments conducted first without, then with prior microbial acclimation to the monoterpenes tested. All four hydrocarbons and two alcohols were readily degraded. The increase in biomass and headspace CO2 concentrations paralleled the depletion of monoterpenes, thus confirming that terpene disappearance was the result of biodegradation accompanied by microbial growth and mineralization. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. A significant fraction of d-limonene-derived carbon was accounted for as non-extractable, dissolved organic carbon, whereas terpineol exhibited a much higher degree of utilization. The rate and extent of monoterpene biodegradation were not significantly affected by the presence of dissolved natural organic matter.

  15. Engineering Flame Retardant Biodegradable Nanocomposites

    NASA Astrophysics Data System (ADS)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  16. Du Pont Information Flow System

    ERIC Educational Resources Information Center

    Hoffman, Warren S.

    1972-01-01

    The Information Flow System is a large-scale information retrieval system developed for processing of Du Pont information files. As currently implemented, the system stores and retrieves information on company technical reports. Extensions of the system for handling chemical structure information and on-line processing are also discussed. (3…

  17. Anaerobic Biodegradation of Soybean Biodiesel and Diesel ...

    EPA Pesticide Factsheets

    Biotransformation of soybean biodiesel and the inhibitory effect of petrodiesel were studied under methanogenic conditions. Biodiesel removal efficiency of more than 95% was achieved in a chemostat with influent biodiesel concentrations up to 2.45 g/L. The kinetics of anaerobic biodegradation of soybean biodiesel B100 (biodiesel only) with different petrodiesel loads were studied using biomass pre-acclimated to B100 and B80 (80% biodiesel and 20 petrodiesel). The results indicated that the biodiesel fraction of the blend could be effectively biodegraded, whereas petrodiesel was not biodegraded at all under methanogenic conditions. The presence of petrodiesel in blends with biodiesel had a greater inhibitory effect on the rate of biodegradation than the biodegradation efficiency (defined as the efficiency of methane production). Both the biodegradation rate coefficient and the methane production efficiency increased almost linearly with the increasing fraction of biodiesel. With the increasing fraction of petrodiesel, the biodegradation rate and efficiency were correlated with the concentration of soluble FAMEs in the water. The objective of this study was to investigate the anaerobic biodegradation of soybean biodiesel blends under methanogenic conditions. Biological methane potential (BMP) tests were conducted in serum bottles to determine the anaerobic biodegradation kinetics of biodiesel in the absence and presence of different concentrations of petrod

  18. Biodegradation of high molecular weight polylactic acid

    NASA Astrophysics Data System (ADS)

    Stloukal, Petr; Koutny, Marek; Sedlarik, Vladimir; Kucharczyk, Pavel

    2012-07-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite expectations, no significant differences in resulting mineralizations were observed for fiber, film and powder sample forms with different specific surface areas. The clearly faster biodegradation was detected only for the thin coating on porous material with high specific surface area.

  19. Phenanthrene biodegradation kinetics in unsaturated soils

    SciTech Connect

    Johnson, C.R.; Scow, K.M.

    1995-12-31

    Organic compounds when sorbed to soil solids are thought to be unavailable to soil microorganisms. The biodegradation kinetics of sorbed chemicals should thus be influenced by sorption/desorption processes as well as by the metabolic capacities of soil microbes. In the research, phenanthrene, a hydrophobic polyaromatic hydrocarbon, was used as a model compound to investigate the biodegradation kinetics of strongly sorbing organic compounds in soil. Biodegradation kinetics for phenanthrene in seven soils with moisture contents near field capacity were measured during a six and one half month experiment. Phenanthrene biodegradation rates initially increased in all soils and then declined. The declining portion of the biodegradation rate versus time plots exhibited either first order or biphasic kinetics. Both first order and biphasic kinetics are consistent with models which link microbial degradation to substrate sorption/desorption from equilibrium and kinetically controlled sorption sites. No single rate constant or analytical expression adequately captured the complexity of the observed biodegradation rates. This result is again consonant with a process derived from coupled biological and physical systems. Biodegradation kinetics were quantified using a combination of fitted and descriptive parameters. Significant correlations exist between several of the descriptive parameters. The correlations observed between descriptive biodegradation parameters mirror correlations expected from the hypothesized underlying biological process and help evince the influence this underlying process exerts on observed biodegradation kinetics.

  20. A review of plastic waste biodegradation.

    PubMed

    Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

    2005-01-01

    With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

  1. Rupture sous-cutanée du tendon long extenseur du pouce: à propos de 5 cas

    PubMed Central

    Abdelillah, Rachid; Abbassi, Najib; Erraji, Moncef; Abdeljawad, Najib; Yacoubi, Hicham; Daoudi, Abdelkrim

    2014-01-01

    La rupture spontanée du muscle long extenseur du pouce (EPL) du tendon au niveau du poignet est rare et principalement rapportés après fracture du radius distal à tubercule de Lister, dans la synovite, ténosynovite ou la polyarthrite rhumatoïde. Nous rapportons 5 cas de rupture spontanée du tendon long extenseur du pouce, traités par une greffe ou un transfert tendineux. PMID:25317233

  2. Structure-biodegradability study and computer-automated prediction of aerobic biodegradation of chemicals

    SciTech Connect

    Klopman, G.; Tu, M.

    1997-09-01

    It is shown that a combination of two programs, MultiCASE and META, can help assess the biodegradability of industrial organic materials in the ecosystem. MultiCASE is an artificial intelligence computer program that had been trained to identify molecular substructures believed to cause or inhibit biodegradation and META is an expert system trained to predict the aerobic biodegradation products of organic molecules. These two programs can be used to help evaluate the fate of disposed chemicals by estimating their biodegradability and the nature of their biodegradation products under conditions that may model the environment.

  3. Anaerobic Biodegradation of soybean biodiesel and diesel ...

    EPA Pesticide Factsheets

    Biotransformation of soybean biodiesel and its biodiesel/petrodiesel blends were investigated under sulfate-reducing conditions. Three blends of biodiesel, B100, B50, and B0, were treated using microbial cultures pre-acclimated to B100 (biodiesel only) and B80 (80% biodiesel and 20% petrodiesel). Results indicate that the biodiesel could be effectively biodegraded in the presence or absence of petrodiesel, whereas petrodiesel could not be biodegraded at all under sulfate-reducing conditions. The kinetics of biodegradation of individual Fatty Acid Methyl Ester (FAME) compounds and their accompanying sulfate-reduction rates were studied using a serum bottle test. As for the biodegradation of individual FAME compounds, the biodegradation rates for the saturated FAMEs decreased with increasing carbon chain length. For unsaturated FAMEs, biodegradation rates increased with increasing number of double bonds. The presence of petrodiesel had a greater effect on the rate of biodegradation of biodiesel than on the extent of removal. The objective of this study was to investigate anaerobic biodegradation of soybean biodiesel and petrodiesel blends in a sulfate-reducing environment, which is a prevalent condition in anaerobic sediments.

  4. Nylon biodegradation by lignin-degrading fungi.

    PubMed Central

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively. PMID:8979361

  5. Biodegradation of aliphatic and aromatic polycarbonates.

    PubMed

    Artham, Trishul; Doble, Mukesh

    2008-01-09

    Polycarbonate is one of the most widely used engineering plastics because of its superior physical, chemical, and mechanical properties. Understanding the biodegradation of this polymer is of great importance to answer the increasing problems in waste management of this polymer. Aliphatic polycarbonates are known to biodegrade either through the action of pure enzymes or by bacterial whole cells. Very little information is available that deals with the biodegradation of aromatic polycarbonates. Biodegradation is governed by different factors that include polymer characteristics, type of organism, and nature of pretreatment. The polymer characteristics such as its mobility, tacticity, crystallinity, molecular weight, the type of functional groups and substituents present in its structure, and plasticizers or additives added to the polymer all play an important role in its degradation. The carbonate bond in aliphatic polycarbonates is facile and hence this polymer is easily biodegradable. On the other hand, bisphenol A polycarbonate contains benzene rings and quaternary carbon atoms which form bulky and stiff chains that enhance rigidity. Even though this polycarbonate is amorphous in nature because of considerable free volume, it is non-biodegradable since the carbonate bond is inaccessible to enzymes because of the presence of bulky phenyl groups on either side. In order to facilitate the biodegradation of polymers few pretreatment techniques which include photo-oxidation, gamma-irradiation, or use of chemicals have been tested. Addition of biosurfactants to improve the interaction between the polymer and the microorganisms, and blending with natural or synthetic polymers that degrade easily, can also enhance the biodegradation.

  6. Getting rid of wastes biodegradation and bioremediation

    SciTech Connect

    Alexander, M.

    1994-12-31

    This book examines the topics of biodegradation and bioremediation of hazardous wastes from the focus of a single author, a microbiologist. Molecular-biology approaches to biodegradation and the engineering approach to degradation are deemphasized, while the kinetics of degradation reactions are covered well. A general approach to the subjects is appropriate for between undergraduate and professional level reading.

  7. Here today, gone tomorrow: biodegradable soft robots

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Winfield, Jonathan; Ieropoulos, Ioannis

    2016-04-01

    One of the greatest challenges to modern technologies is what to do with them when they go irreparably wrong or come to the end of their productive lives. The convention, since the development of modern civilisation, is to discard a broken item and then procure a new one. In the 20th century enlightened environmentalists campaigned for recycling and reuse (R and R). R and R has continued to be an important part of new technology development, but there is still a huge problem of non-recyclable materials being dumped into landfill and being discarded in the environment. The challenge is even greater for robotics, a field which will impact on all aspects of our lives, where discards include motors, rigid elements and toxic power supplies and batteries. One novel solution is the biodegradable robot, an active physical machine that is composed of biodegradable materials and which degrades to nothing when released into the environment. In this paper we examine the potential and realities of biodegradable robotics, consider novel solutions to core components such as sensors, actuators and energy scavenging, and give examples of biodegradable robotics fabricated from everyday, and not so common, biodegradable electroactive materials. The realisation of truly biodegradable robots also brings entirely new deployment, exploration and bio-remediation capabilities: why track and recover a few large non-biodegradable robots when you could speculatively release millions of biodegradable robots instead? We will consider some of these exciting developments and explore the future of this new field.

  8. Current trends in biodegradable polyhydroxyalkanoates.

    PubMed

    Chanprateep, Suchada

    2010-12-01

    The microbial polyesters known as polyhydroxyalkanoates (PHAs) positively impact global climate change scenarios by reducing the amount of non-degradable plastic used. A wide variety of different monomer compositions of PHAs has been described, as well as their future prospects for applications where high biodegradability or biocompatibility is required. PHAs can be produced from renewable raw materials and are degraded naturally by microorganisms that enable carbon dioxide and organic compound recycling in the ecosystem, providing a buffer to climate change. This review summarizes recent research on PHAs and addresses the opportunities as well as challenges for their place in the global market.

  9. Biodegradable stents in gastrointestinal endoscopy

    PubMed Central

    Lorenzo-Zúñiga, Vicente; Moreno-de-Vega, Vicente; Marín, Ingrid; Boix, Jaume

    2014-01-01

    Biodegradable stents (BDSs) are an attractive option to avoid ongoing dilation or surgery in patients with benign stenoses of the small and large intestines. The experience with the currently the only BDS for endoscopic placement, made of Poly-dioxanone, have shown promising results. However some aspects should be improved as are the fact that BDSs lose their radial force over time due to the degradable material, and that can cause stent-induced mucosal or parenchymal injury. This complication rate and modest clinical efficacy has to be carefully considered in individual patients prior to placement of BDSs. Otherwise, the price of these stents therefore it is nowadays an important limitation. PMID:24605020

  10. Biodegradable polymers for electrospinning: towards biomedical applications.

    PubMed

    Kai, Dan; Liow, Sing Shy; Loh, Xian Jun

    2014-12-01

    Electrospinning has received much attention recently due to the growing interest in nano-technologies and the unique material properties. This review focuses on recent progress in applying electrospinning technique in production of biodegradable nanofibers to the emerging field of biomedical. It first introduces the basic theory and parameters of nanofibers fabrication, with focus on factors affecting the morphology and fiber diameter of biodegradable nanofibers. Next, commonly electrospun biodegradable nanofibers are discussed, and the comparison of the degradation rate of nanoscale materials with macroscale materials are highlighted. The article also assesses the recent advancement of biodegradable nanofibers in different biomedical applications, including tissue engineering, drug delivery, biosensor and immunoassay. Future perspectives of biodegradable nanofibers are discussed in the last section, which emphasizes on the innovation and development in electrospinning of hydrogels nanofibers, pore size control and scale-up productions. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Biodegradation of bioplastics in natural environments.

    PubMed

    Emadian, S Mehdi; Onay, Turgut T; Demirel, Burak

    2017-01-01

    The extensive production of conventional plastics and their use in different commercial applications poses a significant threat to both the fossil fuels sources and the environment. Alternatives called bioplastics evolved during development of renewable resources. Utilizing renewable resources like agricultural wastes (instead of petroleum sources) and their biodegradability in different environments enabled these polymers to be more easily acceptable than the conventional plastics. The biodegradability of bioplastics is highly affected by their physical and chemical structure. On the other hand, the environment in which they are located, plays a crucial role in their biodegradation. This review highlights the recent findings attributed to the biodegradation of bioplastics in various environments, environmental conditions, degree of biodegradation, including the identified bioplastic-degrading microorganisms from different microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. L'Aventure du LHC

    ScienceCinema

    None

    2016-07-12

    Cette présentation s’adressera principalement aux personnes qui ont construit le LHC. La construction du LHC fut longue et difficile. De nombreux problèmes sont apparus en cours de route. Tous ont été résolus grâce au dévouement et à l’engagement du personnel et des collaborateurs. Je reviendrai sur les coups durs et les réussites qui ont marqués ces 15 dernières années et je vous montrerai combien cette machine, le fruit de vos efforts, est extraordinaire.

  13. Formulation of microbial cocktails for BTEX biodegradation.

    PubMed

    Nagarajan, Karthiga; Loh, Kai-Chee

    2015-02-01

    BTEX biodegradation by a mixed community of micro-organisms offers a promising approach in terms of cost-effectiveness and elimination of secondary pollution. Two bacterial strains, Pseudomonas putida F1 and Pseudomonas stutzeri OX1 were chosen to formulate synthetic consortia based on their ability to biodegrade the mono-aromatic compounds. Benzene and toluene supported the growth of both the strains; while ethyl benzene and o-xylene were only utilized as growth substrates by P. putida F1 and P. stutzeri OX1, respectively. In a mixed substrate system, P. putida F1 exhibited incomplete removal of o-xylene while P. stutzeri OX1 displayed cometabolic removal of ethyl benzene with dark coloration of the growth medium. The biodegradation potential of the two Pseudomonas species complemented each other and offered opportunities to explore their performance as a co-culture for enhanced BTEX biodegradation. Several microbial formulations were concocted and their BTEX biodegradation characteristics were evaluated. Mixed culture biodegradation ascertained the advantages of the co-culture over the individual Pseudomonas species. This study also emphasized the significance of inoculum density and species proportion while concocting preselected micro-organisms for enhanced BTEX biodegradation.

  14. Microbial Enzymatic Degradation of Biodegradable Plastics.

    PubMed

    Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

    2017-01-01

    The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Aged refinery hydrocarbon biodegradation in soil

    SciTech Connect

    Drake, E.N.; Stokley, K.E.; Calcavecchio, P.

    1995-12-31

    Aged hydrocarbon biodegradation was investigated as a potential cleanup technology for refinery soil. Well-mixed field soil was amended with water and nutrients and tilled weekly for one year in laboratory mesocosms to stimulate biodegradation. Freon infrared analysis of total petroleum hydrocarbons (TPH), and gas chromatography/mass spectrometry (GC/MS) analysis of polynuclear aromatic hydrocarbons (PAHs) and triterpane biomarkers were used to determine the extent of biodegradation. Significant reductions in TPH (up to 68%) and methylene chloride extractable material (up to 55%) were observed. The combined trimethylated phenanthrene/anthracenes (C3P/A) were even more highly depleted than TPH. Nutrient amendment increased TPH, methylene chloride, and C3P/A removal, but not biomarker concentrations. Significant reduction of two to five ring PAHs occurred. Expected depletion patterns for PAHs were observed except in the case of naphthalene and derivatives, phenanthrene/anthracene and derivatives, and chrysene. A possible explanation is that the more readily degradable PAHs were already highly biodegraded before the study and the remaining portions were less available for biodegradation. These results are consistent with reports on the effects of aging on PAH biodegradation in soil. Biodegradation was influenced by PAH structure and molecular weight.

  16. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    PubMed Central

    Zhang, Yi; Yang, Jian

    2013-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology. PMID:23710326

  17. Biodegradable and compostable alternatives to conventional plastics

    PubMed Central

    Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

    2009-01-01

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

  18. Biodegradable and compostable alternatives to conventional plastics.

    PubMed

    Song, J H; Murphy, R J; Narayan, R; Davies, G B H

    2009-07-27

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

  19. Biodegradation of fluorinated alkyl substances.

    PubMed

    Frömel, Tobias; Knepper, Thomas P

    2010-01-01

    The incorporation of fluorine into organic molecules entails both positive and adverse effects. Although fluorine imparts positive and unique properties such as water-and oil-repellency and chemical stability, adverse effects often pervade members of this compound class. A striking property of long perfluoroalkyl chains is their very pronounced environmental persistence. The present review is the first one designed to summarize recent accomplishments in the field of biodegradation of fluorine-containing surfactants, their metabolites, and structural analogs. The pronounced scientific and public interest in these chemicals has given impetus to undertake numerous degradation studies to assess the sources and origins of different fluorinated analog chemical known to exist in the environment. It was shown that biodegradation plays an important role in understanding how fluorinated substances reach the environment and, once they do, what their fate is. Today, PFOS and PFOA are ubiquitously detected as environmental contaminants. Their prominence as contaminants is mainly due to their extreme persistence, which is linked to their perfluoroalkyl chain length. It appears that desulfonation of a highly fluorinated surfactants can be achieved if an α-situated H atom, in relation to the sulfonate group, is present, at least under sulfur-limiting conditions. Molecules that are less heavily fluorinated can show very complex metabolic behavior, as is the case for fluorotelomer alcohols. These compounds are degraded via different but simultaneous pathways, which produce different stable metabolites, one of which is the respective perfluoroalkanoate (8:2-FTOH is transformed to PFOA). Preliminary screening tests indicate that fluorinated functional groups, such as the trifluoromethoxy group and the p-(trifluoromethyl)phenoxy group, may be useful implementations in novel, environmentally benign fluorosurfactants. More specifically, trifluoromethoxy groups constitute a substitute

  20. Antibiotic releasing biodegradable scaffolds for osteomyelitis.

    PubMed

    Nair, Manitha; Krishnan, Amit

    2014-01-01

    Osteomyelitis is characterized by progressive inflammatory bone degeneration. In the management of chronic osteomyelitis, it is necessary to remove the infected bone tissue followed by implantation of an antibiotic releasing biomaterial that can release antibiotic locally for long periods of time. The main carrier used in clinics for this application is polymethylmethacrylate (PMMA) (Eg. Septopal beads). However, major drawback is the need of an additional surgery to remove the beads after therapy, as PMMA is not biodegradable. This necessitates the requirement of biodegradable carrier systems that can release antibiotics and simultaneously support debrided bone formation. This review summarizes biodegradable carrier systems that have been reported for the localised treatment and prophylaxis of osteomyelitis.

  1. Preparation and degradation mechanisms of biodegradable polymer: a review

    NASA Astrophysics Data System (ADS)

    Zeng, S. H.; Duan, P. P.; Shen, M. X.; Xue, Y. J.; Wang, Z. Y.

    2016-07-01

    Polymers are difficult to degrade completely in Nature, and their catabolites may pollute the environment. In recent years, biodegradable polymers have become the hot topic in people's daily life with increasing interest, and a controllable polymer biodegradation is one of the most important directions for future polymer science. This article presents the main preparation methods for biodegradable polymers and discusses their degradation mechanisms, the biodegradable factors, recent researches and their applications. The future researches of biodegradable polymers are also put forward.

  2. Biodegradable polyesters from renewable resources.

    PubMed

    Tsui, Amy; Wright, Zachary C; Frank, Curtis W

    2013-01-01

    Environmental concerns have led to the development of biorenewable polymers with the ambition to utilize them at an industrial scale. Poly(lactic acid) and poly(hydroxyalkanoates) are semicrystalline, biorenewable polymers that have been identified as the most promising alternatives to conventional plastics. However, both are inherently susceptible to brittleness and degradation during thermal processing; we discuss several approaches to overcome these problems to create a balance between durability and biodegradability. For example, copolymers and blends can increase ductility and the thermal-processing window. Furthermore, chain modifications (e.g., branching/crosslinking), processing techniques (fiber drawing/annealing), or additives (plasticizers/nucleating agents) can improve mechanical properties and prevent thermal degradation during processing. Finally, we examine the impacts of morphology on end-of-life degradation to complete the picture for the most common renewable polymers.

  3. New perspectives in plastic biodegradation.

    PubMed

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution.

  4. Engineered biosynthesis of biodegradable polymers.

    PubMed

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

  5. Bacterial synthesis of biodegradable polyhydroxyalkanoates.

    PubMed

    Verlinden, R A J; Hill, D J; Kenward, M A; Williams, C D; Radecka, I

    2007-06-01

    Various bacterial species accumulate intracellular polyhydroxyalkanoates (PHAs) granules as energy and carbon reserves inside their cells. PHAs are biodegradable, environmentally friendly and biocompatible thermoplastics. Varying in toughness and flexibility, depending on their formulation, they can be used in various ways similar to many nonbiodegradable petrochemical plastics currently in use. They can be used either in pure form or as additives to oil-derived plastics such as polyethylene. However, these bioplastics are currently far more expensive than petrochemically based plastics and are therefore used mostly in applications that conventional plastics cannot perform, such as medical applications. PHAs are immunologically inert and are only slowly degraded in human tissue, which means they can be used as devices inside the body. Recent research has focused on the use of alternative substrates, novel extraction methods, genetically enhanced species and mixed cultures with a view to make PHAs more commercially attractive.

  6. Métastases gastro-intestinales du cancer du sein: à propos de 2 cas

    PubMed Central

    Loubna, Mezouar; Mohamed, El Hfid; Tijani, El Harroudi; Fouzia, Ghadouani; Hanane, Haj Kacem; Zouhour, Bourhaleb; Asmae, Ouabdelmoumen

    2013-01-01

    Le cancer du sein est le cancer le plus fréquent chez la femme, notamment au Maroc, avec un taux de mortalité élevé. Les métastases gastro-intestinales d'un carcinome canalaire du sein sont rares. Leur diagnostic est difficile du fait de la nature non spécifique des symptômes. Nous rapportons deux observations originales de métastases gastroduodénales d'un cancer canalaire infiltrant du sein. Les métastases gastro-intestinales du cancer du sein sont très rares; la présence de symptômes gastro-intestinaux chez une malade ayant un antécédent de cancer du sein doit faire suspecter une atteinte métastatique gastro-intestinale. PMID:24198876

  7. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  8. OPTIMIZING BTEX BIODEGRADATION UNDER DENITRIFYING CONDITIONS

    EPA Science Inventory

    Laboratory tests were conducted to determine optimum conditions for benzene, toluene, ethylbenzene, and xylene (collectively known as BTEX) biodegradation by aquifer microorganisms under denitrifying conditions. Microcosms, constructed with aquifer samples from Traverse City, Mic...

  9. Phyllosphere yeasts rapidly break down biodegradable plastics.

    PubMed

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-11-29

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

  10. Polyaspartate scale inhibitors -- Biodegradable alternatives to polyacrylates

    SciTech Connect

    Ross, R.J.; Low, K.C.; Shannon, J.E.

    1996-12-01

    Polyaspartates are highly biodegradable alternatives to polyacrylate based scale inhibitors. This paper presents laboratory testing data on polyaspartate inhibitors of calcium and barium mineral scales. The optimum molecular weight for polyaspartate inhibitors of calcium carbonate, calcium sulfate and barium sulfate mineral scales was determined to be between 1,000 and 4,000 Mw (weight average molecular weight as calculated by Size Exclusion Chromatography). For inhibition of calcium carbonate and barium sulfate, polyaspartates in the range of 3,000-4,000 Mw were most effective. For calcium sulfate inhibition, the optimum molecular weight lies in the 1,000 to 2,000 Mw range. Biodegradability data (OECD 301B Ready Biodegradability) on polyaspartates of a variety of molecular weights is also presented which demonstrates the high biodegradability of this class of mineral scale inhibitors.

  11. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  12. Biodegradation of the anionic surfactant dialkyl sulphosuccinate

    SciTech Connect

    Hales, S.G. . Port Sunlight Lab.)

    1993-10-01

    A range of Organization for Economic Cooperation and Development (OECD) guideline test systems was used to determine the extent and possible mechanisms of biodegradation of dialkyl sulphosuccinate (DASS, C[sub 6]/C[sub 8]). Primary biodegradation of DASS was virtually complete in OECD guideline tests and in simulations of activated sludge sewage treatment systems under both optimal and adverse conditions, and of an anaerobic digester. Ultimate biodegradation increased form about 50% in ready tests to 94% in more powerful inherent tests. [[sup 14]C]DASS was used to determine the fate of the surfactant in activated sludge and in surface waters. Mechanistic studies were performed to ascertain the biodegradative pathway of [[sup 14]C]DASS. A putative degradation pathway for DASS is proposed.

  13. Polyaspartate scale inhibitors -- Biodegradable alternatives to polyacrylates

    SciTech Connect

    Ross, R.J.; Low, K.C.; Shannon, J.E.

    1997-04-01

    Polyaspartates are highly biodegradable alternatives to polyacrylate-based scale inhibitors. This article presents laboratory testing data on polyaspartate inhibitors of calcium and barium mineral scales. The optimum molecular weight (Mw) for polyaspartate inhibitors of calcium carbonate, calcium sulfate, and barium sulfate mineral scales was determined to be between 1,000 Mw and 4,000 Mw. For inhibition of calcium carbonate and barium sulfate, polyaspartates in the range of 3,000 Mw to 4,000 Mw were most effective. For calcium sulfate inhibition, the optimum Mw lies in the 1,000 Mw to 2,000 Mw range. Biodegradability data (OECD 301B Ready Biodegradability) on polyaspartates of a variety of Mw is also presented, which demonstrates the high biodegradability of this class of mineral scale inhibitors.

  14. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  15. MOLECULAR BASIS OF BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS

    EPA Science Inventory

    Chlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacter...

  16. In situ surface biodegradation of restorative materials.

    PubMed

    Padovani, Gc; Fúcio, Sbp; Ambrosano, Gmb; Sinhoreti, Mac; Puppin-Rontani, Rm

    2014-01-01

    SUMMARY This study aimed to evaluate the surface characteristics of restorative materials (roughness, hardness, chemical changes by energy-dispersive spectroscopy [EDX], and scanning electron microscopy [SEM]) submitted to in situ biodegradation. Fifteen discs of each material (IPS e.max [EM], Filtek Supreme [FS], Vitremer [VI], Ketac Molar Easymix [KM], and Amalgam GS-80 [AM]) were fabricated in a metallic mold (4.0 mm × 1.5 mm). Roughness, hardness, SEM, and EDX were then evaluated. Fifteen healthy volunteers used a palatal device containing one disc of each restorative material for seven days. After the biodegradation, the roughness, hardness, SEM, and EDX were once again evaluated. Data obtained from the roughness and hardness evaluations were submitted to Kolmogorov-Smirnov and Tukey-Kramer tests (p<0.05). All esthetic restorative materials showed a significant increase in the roughness after biodegradation. Before biodegradation, significant differences in the hardness among the materials were seen: EM>AM>FS>KM>VI. After biodegradation, the hardness was significantly altered among the materials studied: EM>AM>FS=KM>VI, along with a significant increase in the hardness for AM, KM, and VI. SEM images indicated degradation on the surface of all materials, showing porosities, cracks, and roughness. Furthermore, after biodegradation, FS showed the presence of Cl, K, and Ca on the surface, while F was not present on the VI and KM surfaces. EM and AM did not have alterations in their chemical composition after biodegradation. It was concluded that the dental biofilm accumulation in situ on different restorative materials is a material-dependent parameter. Overall, all materials changed after biodegradation: esthetic restorative materials showed increased roughness, confirmed by SEM, and the ionomer materials and silver amalgam showed a significantly higher hardness. Finally, the initial chemical composition of the composite resin and ionomer materials evaluated was

  17. Biodegradability of commercial and weathered diesel oils

    PubMed Central

    Mariano, Adriano Pinto; Bonotto, Daniel Marcos; de Franceschi de Angelis, Dejanira; Pirôllo, Maria Paula Santos; Contiero, Jonas

    2008-01-01

    This work aimed to evaluate the capability of different microorganisms to degrade commercial diesel oil in comparison to a weathered diesel oil collected from the groundwater at a petrol station. Two microbiological methods were used for the biodegradability assessment: the technique based on the redox indicator 2,6 -dichlorophenol indophenol (DCPIP) and soil respirometric experiments using biometer flasks. In the former we tested the bacterial cultures Staphylococcus hominis, Kocuria palustris, Pseudomonas aeruginosa LBI, Ochrobactrum anthropi and Bacillus cereus, a commercial inoculum, consortia obtained from soil and groundwater contaminated with hydrocarbons and a consortium from an uncontaminated area. In the respirometric experiments it was evaluated the capability of the native microorganisms present in the soil from a petrol station to biodegrade the diesel oils. The redox indicator experiments showed that only the consortia, even that from an uncontaminated area, were able to biodegrade the weathered diesel. In 48 days, the removal of the total petroleum hydrocarbons (TPH) in the respirometric experiments was approximately 2.5 times greater when the commercial diesel oil was used. This difference was caused by the consumption of labile hydrocarbons, present in greater quantities in the commercial diesel oil, as demonstrated by gas chromatographic analyses. Thus, results indicate that biodegradability studies that do not consider the weathering effect of the pollutants may over estimate biodegradation rates and when the bioaugmentation is necessary, the best strategy would be that one based on injection of consortia, because even cultures with recognised capability of biodegrading hydrocarbons may fail when applied isolated. PMID:24031193

  18. Physicochemical properties and biodegradability of crude oil

    SciTech Connect

    Sugiura, Keiji; Ishihara, Masami; Shimauchi, Toshitsugu; Harayama, Shigeaki

    1997-01-01

    The biodegradation of four different crude oil samples, namely, Arabian light, Dubai, Maya, and Shengli, by acinetobacter sp. T4 and by a microbial consortium called SM8 was examined. SM8 exhibited higher activity than Acinetobacter for the biodegradation of all four crude oil samples. The degree of biodegradation of crude oil components differed according to the crude oil, the saturated fraction being more susceptible to biodegradation than the aromatic fraction in all the crude oil samples. The extent of biodegradation by acinetobacter and SM8 was found to be in the order of Arabian light > Dubai > Maya = Shengli; the crude oil samples with higher APl gravity being more susceptible to biodegradation. Saturated compounds of smaller molecular weight were preferentially degraded by both cultures. Acinetobacter could not degrade polycyclic aromatic compounds in the crude oil samples such as (alkyl)naphthalenes, (alky)phenanthrenes, (alkyl)fluorenes, and (alkyl)dibenzothiophenes. However, this strain was capable of degrading more than 10% of the molecules in the aromatic fraction of Arabian light crude oil. An NMR analysis demonstrated that the alkyl side chain of some aromatic molecules was degraded by this organism. In contrast, SM8 degraded the polycyclic aromatic compounds in the crude oil samples, the extent of degradation being in the order of Maya > Shengli > Arabian light > Dubai. 17 refs., 4 figs., 4 tabs.

  19. Substrate inhibition kinetics of phenol biodegradation

    SciTech Connect

    Goudar, C.T.; Ganji, S.H.; Pujar, B.G.; Strevett, K.A.

    2000-02-01

    Phenol biodegradation was studied in batch experiments using an acclimated inoculum and initial phenol concentrations ranging from 0.1 to 1.3 g/L. Phenol depletion an associated microbial growth were monitored over time to provide information that was used to estimate the kinetics of phenol biodegradation. Phenol inhibited biodegradation at high concentrations, and a generalized substrate inhibition model based on statistical thermodynamics was used to describe the dynamics of microbial growth in phenol. For experimental data obtained in this study, the generalized substrate inhibition model reduced to a form that is analogous to the Andrews equation, and the biokinetic parameters {micro}{sub max}, maximum specific growth; K{sub s}, saturation constant; and K{sub i}, inhibition constant were estimated as 0.251 h{sup {minus}1}, 0.011 g/L, and 0.348 g/L, respectively, using a nonlinear least squares technique. Given the wide variability in substrate inhibition models used to describe phenol biodegradation, an attempt was made to justify selection of particular model based on theoretical considerations. Phenol biodegradation data from nine previously published studies were used in the generalized substrate inhibition model to determine the appropriate form of the substrate inhibition model. In all nine cases, the generalized substrate inhibition model reduced to a form analogous to the Andrews equation suggesting the suitability of the Andrews equation to describe phenol biodegradation data.

  20. Anaerobic biodegradation of hexazinone in four sediments.

    PubMed

    Wang, Huili; Xu, Shuxia; Tan, Chengxia; Wang, Xuedong

    2009-05-30

    Anaerobic biodegradation of hexazinone was investigated in four sediments (L1, L2, Y1 and Y2). Results showed that the L2 sediment had the highest biodegradation potential among four sediments. However, the Y1 and Y2 sediments had no capacity to biodegrade hexazinone. Sediments with rich total organic carbon, long-term contamination history by hexazinone and neutral pH may have a high biodegradation potential because the former two factors can induce the growth of microorganisms responsible for biodegradation and the third factor can offer suitable conditions for biodegradation. The addition of sulfate or nitrate as electron acceptors enhanced hexazinone degradation. As expected, the addition of electron donors (lactate, acetate or pyruvate) substantially inhibited the degradation. In natural environmental conditions, the effect of intermediate A [3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H, 3H)dione] on anaerobic hexazinone degradation was negligible because of its low level.

  1. Immersed multilayer biodegradable ureteral stent with reformed biodegradation: An in vitro experiment.

    PubMed

    Yang, Ganggang; Xie, Hua; Huang, Yichen; Lv, Yiqing; Zhang, Mingqing; Shang, Yafeng; Zhou, Junmei; Wang, Liping; Wang, Jin-Ye; Chen, Fang

    2017-03-01

    Objective The aim of this study was to develop a novel immersed multilayer biodegradable ureteral stent with reformed biodegradation and evaluate it in vitro. Methods Poly(glycolic-co-lactic acid) (PGLA), microsphere zein and BaSO4 were employed to produce a multilayer biodegradable stent using immersion technology. Tests of the biodegradable stents and conventional control stents were conducted in human urine in vitro to evaluate the biodegradable properties. The biocompatibility was assessed by the morphology and proliferation of urine-derived cells cultured with extracted media from the biodegradable stent and a latex material positive control. Results An immersed multilayer biodegradable stent was successfully produced. It began to degrade in week 2 and was fully degraded by week 4. The mass loss ratio in the first 2 weeks was low (approximately 10.0% at 1 week, 20.0% at 2 weeks) and increased after 3 weeks (approximately 70%) to the end of testing. During the first 2 weeks, the radial compression load performances of the biodegradable stents were better than those of the control stents with statistically significant differences ( p = 0.00, p = 0.01) and the tensile strengths were lower in the biodegradable stents than those in the control stents throughout the experiment. SEM showed that the stents degraded layer by layer from the outer to the inner wall. The influences on the cells of extracted medium from the biodegradable stents were morphologically slight and lower than 10% in relative growth rates. Conclusions This preliminary study demonstrates that the immersed multilayer biodegradable ureteral stent has good radial compression and biocompatible performance and can be degraded in vitro within 4 weeks in a moderate manner.

  2. Evaluation of biodegradation-promoting additives for plastics.

    PubMed

    Selke, Susan; Auras, Rafael; Nguyen, Tuan Anh; Castro Aguirre, Edgar; Cheruvathur, Rijosh; Liu, Yan

    2015-03-17

    Biodegradation-promoting additives for polymers are increasingly being used around the world with the claim that they effectively render commercial polymers biodegradable. However, there is a lot of uncertainty about their effectiveness in degrading polymers in different environments. In this study, we evaluated the effect of biodegradation-promoting additives on the biodegradation of polyethylene (PE) and polyethylene terephthalate (PET). Biodegradation was evaluated in compost, anaerobic digestion, and soil burial environments. None of the five different additives tested significantly increased biodegradation in any of these environments. Thus, no evidence was found that these additives promote and/or enhance biodegradation of PE or PET polymers. So, anaerobic and aerobic biodegradation are not recommended as feasible disposal routes for nonbiodegradable plastics containing any of the five tested biodegradation-promoting additives.

  3. Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

    PubMed

    Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

    2011-03-01

    The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Fungal biodegradation of phthalate plasticizer in situ.

    PubMed

    Pradeep, S; Faseela, P; Josh, M K Sarath; Balachandran, S; Devi, R Sudha; Benjamin, Sailas

    2013-04-01

    This unique study describes how Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n-hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5% w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15-0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

  5. ETHANOL BIODEGRADATION FROM GASOLINE RELEASES AND ITS EFFECT ON BTEX BIODEGRADATIONS

    EPA Science Inventory

    How fast will ethanol biodegrade and what impact will it have on the biodegradation of BTEX in a gasoline spill? This session will provide evidence to answer these questions based on laboratory data. Material from UST spills from Long Island, New York, New Jersey, Florida, and ...

  6. Approche de prise en charge du trouble du spectre de l’autisme

    PubMed Central

    Lee, Patrick F.; Thomas, Roger E.; Lee, Patricia A.

    2015-01-01

    Résumé Objectif Se pencher sur les critères diagnostiques du trouble du spectre de l’autisme (TSA) comme les définit le Manuel diagnostique et statistique des troubles mentaux, cinquième édition (DSM-V), et concevoir une approche de prise en charge du TSA à l’aide du cadre CanMEDS–Médecine familiale (CanMEDS-MF). Sources d’information Le DSM-V, publié par l’American Psychiatric Association en mai 2013, énonce de nouveaux critères diagnostiques du TSA. Le cadre CanMEDS-MF du Collège des médecins de famille du Canada fournit un plan d’orientation pour la prise en charge complexe du TSA. Nous avons utilisé des données recueillies par le Centers for Disease Control and Prevention afin de déterminer la prévalence du TSA, ainsi que la revue systématique et méta-analyse détaillée effectuée par le National Institute for Health and Care Excellence du R.-U. pour ses lignes directrices sur le TSA dans le but d’évaluer les données probantes issues de plus de 100 interventions. Message principal Selon les données du Centers for Disease Control and Prevention, la prévalence du TSA se chiffrait à 1 sur 88 en 2008 aux États-Unis. La classification du TSA dans la quatrième édition du DSM incluait l’autisme, le syndrome d’Asperger, le trouble envahissant du développement et le trouble désintégratif de l’enfance. La dernière révision du DSM-V réunit tous ces troubles sous la mention TSA, avec différents niveaux de sévérité. La prise en charge du TSA est complexe; elle exige les efforts d’une équipe multidisciplinaire ainsi que des soins continus. Les rôles CanMEDS-MF fournissent un cadre de prise en charge. Conclusion Les médecins de famille sont au cœur de l’équipe de soins multidisciplinaire pour le TSA, et le cadre CanMEDS-MF tient lieu de plan détaillé pour guider la prise en charge d’un enfant atteint de TSA et aider la famille de cet enfant.

  7. Biodegradation of central intermediate compounds produced from biodegradation of aromatic compounds.

    PubMed

    Cinar, Ozer

    2004-10-01

    In this study I consider the incomplete biodegradation of aromatic compounds during the waste- water cycle between aerobic or anaerobic zones in biological nutrient removal processes, including aerobic biodegradation of compounds (such as cyclohex-l-ene-1-carboxyl-CoA) produced during the incomplete anaerobic biodegradation of aromatic compounds, and anaerobic biodegradation of compounds (such as catechol, protocatechuate, and gentisic acid) produced during the incomplete aerobic biodegradation of aromatic compounds. Anaerobic degradation of the aerobic central intermediates that result from the incomplete aero-bic degradation of aromatic compounds usually leads to benzoyl-CoA. On the other hand, aerobic degradation of the anaerobic central intermediates that result from the incomplete anaerobic degradation of aromatic compounds usually leads to protocatechuate.

  8. Les plaies du tendon patellaire

    PubMed Central

    Mechchat, Atif; Elidrissi, Mohammed; Mardy, Abdelhak; Elayoubi, Abdelghni; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les plaies du tendon patellaire sont peu fréquentes et sont peu rapportés dans la littérature, contrairement aux ruptures sous cutanées. Les sections du tendon patellaire nécessitent une réparation immédiate afin de rétablir l'appareil extenseur et de permettre une récupération fonctionnelle précoce. A travers ce travail rétrospectif sur 13 cas, nous analysons les aspects épidémiologiques, thérapeutiques et pronostiques de ce type de pathologie en comparant différents scores. L’âge moyen est de 25 ans avec une prédominance masculine. Les étiologies sont dominées par les accidents de la voie publique (68%) et les agressions par agent tranchant (26%) et contendant (6 %). Tous nos patients ont bénéficié d'un parage chirurgical avec suture tendineuse direct protégée par un laçage au fils d'aciers en légère flexion. La rééducation est débutée après sédation des phénomènes inflammatoires. Au dernier recul les résultats sont excellents et bon à 92%. Nous n'avons pas noté de différence de force musculaire et d'amplitude articulaire entre le genou sain et le genou lésé. Les lésions ouvertes du tendon patellaire est relativement rare. La prise en charge chirurgicale rapide donne des résultats assez satisfaisants. La réparation est généralement renforcée par un semi-tendineux, synthétique ou métallique en forme de cadre de renfort pour faciliter la réadaptation et réduire le risque de récidive après la fin de l'immobilisation. PMID:25170379

  9. Hydrocarbon Biodegradation in Hypersaline Environments

    PubMed Central

    Ward, David M.; Brock, T. D.

    1978-01-01

    When mineral oil, hexadecane, and glutamate were added to natural samples of varying salinity (3.3 to 28.4%) from salt evaporation ponds and Great Salt Lake, Utah, rates of metabolism of these compounds decreased as salinity increased. Rate limitations did not appear to relate to low oxygen levels or to the availability of organic nutrients. Some oxidation of l-[U-14C]glutamic acid occurred even at extreme salinities, whereas oxidation of [1-14C]hexadecane was too low to be detected. Gas chromatographic examination of hexane-soluble components of tar samples from natural seeps at Rozel Point in Great Salt Lake demonstrated no evidence of biological oxidation of isoprenoid alkanes subject to degradation in normal environments. Some hexane-soluble components of the same tar were altered by incubation in a low-salinity enrichment culture inoculated with garden soil. Attempts to enrich for microorganisms in saline waters able to use mineral oil as a sole source of carbon and energy were successful below, but not above, about 20% salinity. This study strongly suggests a general reduction of metabolic rate at extreme salinities and raises doubt about the biodegradation of hydrocarbons in hypersaline environments. PMID:16345276

  10. Fungal biodegradation of pomegranate ellagitannins.

    PubMed

    Ascacio-Valdés, Juan A; Buenrostro, José J; De la Cruz, Reynaldo; Sepúlveda, Leonardo; Aguilera, Antonio F; Prado, Arely; Contreras, Juan C; Rodríguez, Raúl; Aguilar, Cristóbal N

    2014-01-01

    Ellagitannins (ETs) are phytochemicals derived from secondary metabolism associated to defense system, with complex chemical structures, which have high participation during all stages of protection against microbial infection. In this study, we report the fungal biodegradation of a bioactive ET, named punicaline which was recovered and purified from pomegranate peels and used as carbon source in solid-state culture (SSC) using polyurethane as solid support. SSC was kinetically monitored during 36 h of incubation time. ETs and glycosides consumption were spectrophotometrically determined. Ellagic acid (EA) accumulation was analyzed by HPLC. Several enzymatic activities were assayed (cellulase, xylanase, β-glucosydase, polyphenoloxidase, tannase, and ET hydrolyzing activities). The consumption levels of ETs and glycosides were 66 and 40%, while EA accumulation reached 42.02 mg g(-1). A differential pattern of enzymatic activities was found; evidence from our studies suggests that the ET hydrolyzing activity is directly associated to EA accumulation, and production of this enzyme may represent the most critical step to successfully develop a bioprocess for production of an important bioactive compound, the EA. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Biodegradation of Phenanthrene Sorbed to Biochars

    NASA Astrophysics Data System (ADS)

    Kang, S.; Choi, Y.; Jung, J.; Ok, Y.

    2016-12-01

    Biochar is a porous organic matter produced from pyrolysis of biomass. Because of its high carbon content and large surface area, biochar has a high potential to sorb organic pollutants from various environments. However, there is limited knowledge on the behavior of organic pollutants sorbed to biochars. The goal of this study is to investigate the biodegradability of a model organic pollutant, phenanthrene, adsorbed to biochars with different physicochemical properties. Biochars were produced from different feedstocks, rice husk, wood chip, soybean stover, and sewage sludge, with pyrolysis temperatures of 500°C, 250°C, 700°C, and 500°C, to obtain those with different physicochemical properties. After sorption of phenanthrene, the biochars were added to a minimal medium inoculated with a phenanthrene-degrading bacterial species Pseudomonas putida. Phenanthrene biodegradation was monitored over time by measuring the CO2 evolution. The fraction of biodegradable phenanthrene ranged from 4.8% to 54% with a maximum value of 54% for the rice husk biochar. The first-order biodegradation rate constant was in the range of 0.035 to 0.096 d-1, which is comparable to the rate constant of 0.049 d-1 for the no-biochar control. Biochar desorption tests were conducted for rice husk and wood chip biochars. The desorption tests indicated that 61% and 59% of phenanthrene could be desorbed from the rice husk and wood chip biochars respectively. The estimated fraction of desorption corresponded relatively well with the biodegradable fraction for the rice husk biochar. However, for the wood chip biochar, the biodegradable fraction was significantly smaller than the fraction of desorption, suggesting inhibited or attenuated degradation of the sorbed phenanthrene. Our results suggest that the biodegradability of phenanthrene sorbed to biochars is limited by resistance to desorption as well as other factors that are currently unknown.

  12. Biomechanical Challenges to Polymeric Biodegradable Stents.

    PubMed

    Soares, Joao S; Moore, James E

    2016-02-01

    Biodegradable implants have demonstrated clinical success in simple applications (e.g., absorbable sutures) and have shown great potential in many other areas of interventional medicine, such as localized drug delivery, engineered tissue scaffolding, and structural implants. For endovascular stenting and musculoskeletal applications, they can serve as temporary mechanical support that provides a smooth stress-transfer from the degradable implant to the healing tissue. However, for more complex device geometries, in vivo environments, and evolving load-bearing functions, such as required for vascular stents, there are considerable challenges associated with the use of biodegradable materials. A biodegradable stent must restore blood flow and provide support for a predictable appropriate period to facilitate artery healing, and subsequently, fail safely and be absorbed in a controllable manner. Biodegradable polymers are typically weaker than metals currently employed to construct stents, so it is difficult to ensure sufficient strength to keep the artery open and alleviate symptoms acutely while keeping other design parameters within clinically acceptable ranges. These design challenges are serious, given the general lack of understanding of biodegradable polymer behavior and evolution in intimal operating conditions. The modus operandi is mainly empirical and relies heavily on trial-and-error methodologies burdened by difficult, resource-expensive, and time-consuming experiments. We are striving for theoretical advancements systematizing the empirical knowledge into rational frameworks that could be cast into in silico tools for simulation and product development optimization. These challenges are evident when one considers that there are no biodegradable stents on the US market despite more than 30 years of development efforts (and currently only a couple with CE mark). This review summarizes previous efforts at implementing biodegradable stents, discusses the

  13. Prediction of biodegradability from chemical structure: Modeling or ready biodegradation test data

    SciTech Connect

    Loonen, H.; Lindgren, F.; Hansen, B.

    1999-08-01

    Biodegradation data were collected and evaluated for 894 substances with widely varying chemical structures. All data were determined according to the Japanese Ministry of International Trade and Industry (MITI) I test protocol. The MITI I test is a screening test for ready biodegradability and has been described by Organization for Economic Cooperation and Development (OECD) test guideline 301 C and European Union (EU) test guideline C4F. The chemicals were characterized by a set of 127 predefined structural fragments. This data set was used to develop a model for the prediction of the biodegradability of chemicals under standardized OECD and EU ready biodegradation test conditions. Partial least squares (PLS) discriminant analysis was used for the model development. The model was evaluated by means of internal cross-validation and repeated external validation. The importance of various structural fragments and fragment interactions was investigated. The most important fragments include the presence of a long alkyl chain; hydroxy, ester, and acid groups (enhancing biodegradation); and the presence of one or more aromatic rings and halogen substituents (regarding biodegradation). More than 85% of the model predictions were correct for using the complete data set. The not readily biodegradable predictions were slightly better than the readily biodegradable predictions (86 vs 84%). The average percentage of correct predictions from four external validation studies was 83%. Model optimization by including fragment interactions improve the model predicting capabilities to 89%. It can be concluded that the PLS model provides predictions of high reliability for a diverse range of chemical structures. The predictions conform to the concept of readily biodegradable (or not readily biodegradable) as defined by OECD and EU test guidelines.

  14. Biodegradability of ethylenediamine-based complexing agents.

    PubMed

    Sýkora, V; Pitter, P; Bittnerová, I; Lederer, T

    2001-06-01

    Biological degradability of ethylenediamine derivatives depends on the type and number of substituents. The susceptibility to biodegradation decreases in the sequence of substituents -COCH3, -CH3, -C2H5, -CH2CH2OH, -CH2COOH and with polysubstitution. The biodegradability depends also on the kind and number of nitrogen atoms. Complexing agents with a single-nitrogen atom in the molecule (e.g. NTA) succumb relatively readily to biodegradation whereas, compounds with two or more tertiary amino groups are biologically highly stable and do not undergo biodegradation even in experiments with activated sludge adapted at an age of up to 30 days (EDTA, DTPA, PDTA, HEDTA). A lowering of the degree of substitution brings about an increased susceptibility to biodegradation. This holds, e.g., for replacement of tertiary amino groups with secondary ones; thus the symmetrically disubstituted ethylenediamine-N,N'-diacetic acid (EDDA) possesses still sufficient complexing ability while belonging already to the group of potentially degradable substances.

  15. Biodegradable compounds: Rheological, mechanical and thermal properties

    NASA Astrophysics Data System (ADS)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  16. Biodegradable lignin/polyolefin composite films

    SciTech Connect

    Kosikova, B.; Demjanova, V.; Mikulasova, M.; Lora, J.H.

    1993-12-31

    From the view point of environmental protection, the plastic wastes, especially from packing materials, represent a potential waste problem. Various approaches were examined to develop partially or completely biodegradable plastics. New type of partially biodegradable polyolefins was prepared by blending of polypropylene with lignin, which was recovered in the ALCELL process, an organosolv pulping process that uses ethanol-water as the delignifying agent. Films of blends with up to 10% wt ALCELL lignin, prepared in absence of commercial stabilizers, had acceptable mechanical strengths. The effect of lignin on biodegradability of the composite films was examined by comparison of behaviour of both pure and lignin containing films during treatment with fungus Phanerochaete chrysosporium. It was found that this fungus is able to grow and to produce lignolytic enzymes in the presence of the films containing lignin. Biodegradation of lignin in the composite film was confirmed by the releasing of lignin fragments into the extracellular fluid. Because of measurement of mechanical properties offers a mean of direct estimation of polymer degradation, the degree of biodegradation of the films tested was followed by monitoring of elongation at break. The changes of break at elongation in the course of enzymatic treatment revealed that the lignin/PP composite films are potentially environmentally nonpersisting. The micrographs of the lignin containing films obtained by scanning electron microscopy show the significant changes of the film surface upon degradation with Phanerochaete chrysosporium in contrast to unchanged lignin free film.

  17. Biodegradability of organic nanoparticles in the aqueous environment.

    PubMed

    Kümmerer, Klaus; Menz, Jakob; Schubert, Thomas; Thielemans, Wim

    2011-03-01

    Synthetic nanoparticles have already been detected in the aquatic environment. Therefore, knowledge on their biodegradability is of utmost importance for risk assessment but such information is currently not available. Therefore, the biodegradability of fullerenes, single, double, multi-walled as well as COOH functionalized carbon nanotubes and cellulose and starch nanocrystals in aqueous environment has been investigated according to OECD standards. The biodegradability of starch and cellulose nanoparticles was also compared with the biodegradability of their macroscopic counterparts. Fullerenes and all carbon nanotubes did not biodegrade at all, while starch and cellulose nanoparticles biodegrade to similar levels as their macroscopic counterparts. However, neither comfortably met the criterion for ready biodegradability (60% after 28 days). The cellulose and starch nanoparticles were also found to degrade faster than their macroscopic counterparts due to their higher surface area. These findings are the first report of biodegradability of organic nanoparticles in the aquatic environment, an important accumulation environment for manmade compounds.

  18. Evaluating the primary and ready biodegradability of dianilinodithiophosphoric acid.

    PubMed

    Lin, Weixiong; Sun, Shuiyu; Xu, Pingting; Dai, Yongkang; Ren, Jie

    2016-04-01

    Dianilinodithiophosphoric acid (DDA) is widely used as sulfide mineral flotation collector in China. It is necessary to investigate the biodegradability of DDA to provide the fundamental knowledge to assess the environmental fate in the risk assessment of DDA and to design and operate the DDA flotation wastewater biological treatment plant. In the present study, the primary and ready aerobic biodegradations of DDA were studied and the primary biodegradation kinetic model of DDA was developed. The results show that DDA displays a good primary biodegradability and its biodegradation ratio reaches 99.8 % in 7 days. In contrast, DDA is not easily ready biodegradable; hence, it is a partially biodegradable organic compound. The primary aerobic biodegradation kinetics can be described using the first-order reaction kinetics equation: C = 19.72191e(-0.01513t).

  19. Introduction of Environmentally Degradable Parameters to Evaluate the Biodegradability of Biodegradable Polymers

    PubMed Central

    Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter (EdK) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept EdK was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated EdK was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the EdK values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of EdK for each material. The EdK values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the EdK was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  20. Introduction of environmentally degradable parameters to evaluate the biodegradability of biodegradable polymers.

    PubMed

    Guo, Wenbin; Tao, Jian; Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter ((Ed)K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept (Ed)K was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated (Ed)K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the (Ed)K values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of (Ed)K for each material. The (Ed)K values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the (Ed)K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment.

  1. DU-127090 Solvay/H Lundbeck.

    PubMed

    Wolf, William

    2003-01-01

    DU-127090 is a mixed dopamine antagonist/serotonin agonist in development by Solvay and H Lundbeck as a potential treatment for psychosis and schizophrenia, for which it is in phase II clinical trials. In August 2002, phase II trials were ongoing and Lundbeck expected to commence phase III trials in 2003 and file an NDA after 2004. DU-127090 is also under development for Parkinson's disease, for which it is in phase I clinical trials.

  2. Novel biodegradable nanocarriers for enhanced drug delivery.

    PubMed

    Gagliardi, Mariacristina

    2016-12-01

    With the refinement of functional properties, the interest around biodegradable materials, in biorelated applications and, in particular, in their use as controlled drug-delivery systems, increased in the last decades. Biodegradable materials are an ideal platform to obtain nanoparticles for spatiotemporal controlled drug delivery for the in vivo administration, thanks to their biocompatibility, functionalizability, the control exerted on delivery rates and the complete degradation. Their application in systems for cancer treatment, brain and cardiovascular diseases is already a consolidated practice in research, while the bench-to-bedside translation is still late. This review aims at summarizing reported applications of biodegradable materials to obtain drug-delivery nanoparticles in the last few years, giving a complete overview of pros and cons related to degradable nanomedicaments.

  3. Biodegradable Hybrid Stomatocyte Nanomotors for Drug Delivery.

    PubMed

    Tu, Yingfeng; Peng, Fei; André, Alain A M; Men, Yongjun; Srinivas, Mangala; Wilson, Daniela A

    2017-02-28

    We report the self-assembly of a biodegradable platinum nanoparticle-loaded stomatocyte nanomotor containing both PEG-b-PCL and PEG-b-PS as a potential candidate for anticancer drug delivery. Well-defined stomatocyte structures could be formed even after incorporation of 50% PEG-b-PCL polymer. Demixing of the two polymers was expected at high percentage of semicrystalline poly(ε-caprolactone) (PCL), resulting in PCL domain formation onto the membrane due to different properties of two polymers. The biodegradable motor system was further shown to move directionally with speeds up to 39 μm/s by converting chemical fuel, hydrogen peroxide, into mechanical motion as well as rapidly delivering the drug to the targeted cancer cell. Uptake by cancer cells and fast doxorubicin drug release was demonstrated during the degradation of the motor system. Such biodegradable nanomotors provide a convenient and efficient platform for the delivery and controlled release of therapeutic drugs.

  4. Experimental studies on waste paper pulp biodegradation.

    PubMed

    Sharma, R; Sharma, D; Rao, K S; Jain, R C

    2002-07-01

    In continuation of their studies on Biodegradation of cellulosic waste materials, the authors have presented their experimental data on biodegradation on waste paper pulp. Greater efficiency in the cow dung and M3 culture experimental setups have been pointed out and discussed. Necessity of detailed data evaluation of temperature, pH, dry weight, cellulose, protein, carbohydrate, Nitrate, Phosphate & Potassium levels is suggested. Derivation of %, absolute and increase/decrease % of BOO, COD and VS have been pointed out for the first time in solid waste Biodegradation. Further data evaluation and derivation of critical reaction rate kinetics have been recommended for further studies in solid waste-degradation to achieve quicker Bioconversion of cellulosic wastes into compost.

  5. Biodegradability of wheat gluten based bioplastics.

    PubMed

    Domenek, Sandra; Feuilloley, Pierre; Gratraud, Jean; Morel, Marie-Hélène; Guilbert, Stéphane

    2004-01-01

    A large variety of wheat gluten based bioplastics, which were plasticized with glycerol, were subjected to biodegradation. The materials covered the total range available for the biochemical control parameter Fi, which expresses the percentage of aggregated proteins. This quantity can be related to the density of covalent crosslinks in the wheat gluten network, which are induced by technological treatments. The biodegradability tests were performed in liquid medium (modified Sturm test) and in farmland soil. All gluten materials were fully degraded after 36 days in aerobic fermentation and within 50 days in farmland soil. No significant differences were observed between the samples. The mineralization half-life time of 3.8 days in the modified Sturm test situated gluten materials among fast degrading polymers. The tests of microbial inhibition experiments revealed no toxic effects of the modified gluten or of its metabolites. Thus, the protein bulk of wheat gluten materials is non-toxic and fully biodegradable, whatever the technological process applied.

  6. Biodegradable Photonic Melanoidin for Theranostic Applications.

    PubMed

    Lee, Min-Young; Lee, Changho; Jung, Ho Sang; Jeon, Mansik; Kim, Ki Su; Yun, Seok Hyun; Kim, Chulhong; Hahn, Sei Kwang

    2016-01-26

    Light-absorbing nanoparticles for localized heat generation in tissues have various biomedical applications in diagnostic imaging, surgery, and therapies. Although numerous plasmonic and carbon-based nanoparticles with strong optical absorption have been developed, their clearance, potential cytotoxicity, and long-term safety issues remain unresolved. Here, we show that "generally regarded as safe (GRAS)" melanoidins prepared from glucose and amino acid offer a high light-to-heat conversion efficiency, biocompatibility, biodegradability, nonmutagenicity, and efficient renal clearance, as well as a low cost for synthesis. We exhibit a wide range of biomedical photonic applications of melanoidins, including in vivo photoacoustic mapping of sentinel lymph nodes, photoacoustic tracking of gastrointestinal tracts, photothermal cancer therapy, and photothermal lipolysis. The biodegradation rate and renal clearance of melanoidins are controllable by design. Our results confirm the feasibility of biodegradable melanoidins for various photonic applications to theranostic nanomedicines.

  7. Biodegradable nanoparticles for gene therapy technology

    NASA Astrophysics Data System (ADS)

    Hosseinkhani, Hossein; He, Wen-Jie; Chiang, Chiao-Hsi; Hong, Po-Da; Yu, Dah-Shyong; Domb, Abraham J.; Ou, Keng-Liang

    2013-07-01

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

  8. Materials derived from biomass/biodegradable materials.

    PubMed Central

    Luzier, W D

    1992-01-01

    Interest in biodegradable plastics made from renewable resources has increased significantly in recent years. PHBV (polyhydroxybutyrate-polyhydroxyvalerate) copolymers are good examples of this type of materials. This paper provides an overview of the manufacturing process, properties, biodegradability, and application/commercial issues associated with PHBV copolymers. They are naturally produced by bacteria from agricultural raw materials, and they can be processed to make a variety of useful products, where their biodegradability and naturalness are quite beneficial. PHBV copolymers are still in the first stage of commercialization. But they are presented in this paper as an example of how new technology can help meet society's needs for plastics and a clean environment. Images PMID:1736301

  9. Biodegradable Hybrid Stomatocyte Nanomotors for Drug Delivery

    PubMed Central

    2017-01-01

    We report the self-assembly of a biodegradable platinum nanoparticle-loaded stomatocyte nanomotor containing both PEG-b-PCL and PEG-b-PS as a potential candidate for anticancer drug delivery. Well-defined stomatocyte structures could be formed even after incorporation of 50% PEG-b-PCL polymer. Demixing of the two polymers was expected at high percentage of semicrystalline poly(ε-caprolactone) (PCL), resulting in PCL domain formation onto the membrane due to different properties of two polymers. The biodegradable motor system was further shown to move directionally with speeds up to 39 μm/s by converting chemical fuel, hydrogen peroxide, into mechanical motion as well as rapidly delivering the drug to the targeted cancer cell. Uptake by cancer cells and fast doxorubicin drug release was demonstrated during the degradation of the motor system. Such biodegradable nanomotors provide a convenient and efficient platform for the delivery and controlled release of therapeutic drugs. PMID:28187254

  10. Biodegradable Polymers and Stem Cells for Bioprinting.

    PubMed

    Lei, Meijuan; Wang, Xiaohong

    2016-04-29

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  11. Kinetics of monomer biodegradation in soil.

    PubMed

    Siotto, Michela; Sezenna, Elena; Saponaro, Sabrina; Innocenti, Francesco Degli; Tosin, Maurizio; Bonomo, Luca; Mezzanotte, Valeria

    2012-01-01

    In modern intensive agriculture, plastics are used in several applications (i.e. mulch films, drip irrigation tubes, string, clips, pots, etc.). Interest towards applying biodegradable plastics to replace the conventional plastics is promising. Ten monomers, which can be applied in the synthesis of potentially biodegradable polyesters, were tested according to ASTM 5988-96 (standard respirometric test to evaluate aerobic biodegradation in soil by measuring the carbon dioxide evolution): adipic acid, azelaic acid, 1,4-butanediol, 1,2-ethanediol, 1,6-hexanediol, lactic acid, glucose, sebacic acid, succinic acid and terephthalic acid. Eight replicates were carried out for each monomer for 27-45 days. The numerical code AQUASIM was applied to process the CO₂ experimental data in order to estimate values for the parameters describing the different mechanisms occurring to the monomers in soil: i) the first order solubilization kinetic constant, K(sol) (d⁻¹); ii) the first order biodegradation kinetic constant, K(b) (d⁻¹); iii) the lag time in biodegradation, t(lag) (d); and iv) the carbon fraction biodegraded but not transformed into CO₂, Y (-). The following range of values were obtained: [0.006 d⁻¹, 6.9 d⁻¹] for K(sol), [0.1 d⁻¹, 1.2 d⁻¹] for K(b), and [0.32-0.58] for Y; t(lag) was observed for azelaic acid, 1,2-ethanediol, and terephthalic acid, with estimated values between 3.0 e 4.9 d. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Injectable biodegradable materials for orthopedic tissue engineering.

    PubMed

    Temenoff, J S; Mikos, A G

    2000-12-01

    The large number of orthopedic procedures performed each year, including many performed arthroscopically, have led to great interest in injectable biodegradable materials for regeneration of bone and cartilage. A variety of materials have been developed for these applications, including ceramics, naturally derived substances and synthetic polymers. These materials demonstrate overall biocompatibility and appropriate mechanical properties, as well as promote tissue formation, thus providing an important step towards minimally invasive orthopedic procedures. This review provides a comparison of these materials based on mechanical properties, biocompatibility and regeneration efficacy. Advantages and disadvantages of each material are explained and design criteria for injectable biodegradable systems are provided.

  13. Biodegradable containers from green waste materials

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  14. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    NASA Astrophysics Data System (ADS)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  15. Biokinetics and dosimetry of depleted uranium (DU) in rats implanted with DU fragments.

    SciTech Connect

    Guilmette, Ray A.; Hahn, Fletcher F.; Durbin, P. W.

    2004-01-01

    A number of U. S. veterans of the Persian Gulf War were wounded with depleted uranium (DU) metal fragments as a result of 'friendly fire' incidents, in which Abrams tanks and Bradley fighting vehicles were struck by DU anti-armor munitions. Some of the crew members who survived were left with multiple small fragments of DU in their muscles and soft tissues. The number, size and location of the fragments made them inoperable in general, and therefore subject to long-term retention. Because there was inadequate data to predict the potential carcinogenicity of DU fragments in soft tissues, Hahn et al. (2003) conducted a lifespan cancer study in rats. As part of that study, a number of rats were maintained to study the biokinetics and dosimetry of DU implanted intramuscularly in male Wistar rats. Typically, four metal fragments, either as cylindrical pellets or square wafers were implanted into the biceps femoris muscles of the rats. Urine samples were collected periodically during their lifespans, and DU was analyzed in kidneys and eviscerated carcass (minus the implant sites) at death. The daily DU urinary excretion rate increased steeply during the first 30 d after implantation peaking at about 90 d at 3-10 x 10{sup -3}%/d. During the first 150 d, the average excretion rate was 2.4 x 10{sup -3}%/d, decreasing thereafter to about 1 x 10{sup -3}%/d. Serial radiographs were made of the wound sites to monitor gross morphologic changes in the DU implant and the surrounding tissue. As early as 1 w after implantation, radiographs showed the presence of surface corrosion and small, dense bodies near the original implant, presumably DU. This corrosion from the surface of the implant continued with time, but did not result in an increasing amount of DU reaching the blood and urine after the first 3 mo. During this 3-mo period, connective tissue capsules formed around the implants, and are hypothesized to have reduced the access of DU to tissue fluids by limiting the diffusion

  16. A review of biodegradation of synthetic plastic and foams.

    PubMed

    Gautam, R; Bassi, A S; Yanful, E K

    2007-04-01

    Synthetic polymeric foams have pervaded every aspect of modern life. Although foams provide numerous benefits, they also cause a significant environmental litter problem because of their recalcitrant and xenobiotic nature. Biodegradation may provide solution to the problem, but not enough is known about the biodegradation process of synthetic plastic and plasticbased foams. This review has been written to provide an overview of the current state of plastic foam biodegradation. Several biodegradation pathways of a few select synthetic polymers are also presented along with a discussion on some of the physico-chemical factors that can influence the biodegradation of plastic foams.

  17. Biodegradation Of thermoplastic polyurethanes from vegetable oils

    USDA-ARS?s Scientific Manuscript database

    Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration were prepared. Soft segment concentration was varied fro, 40 to 70 wt %. Biodegradation was studied by respirometry. Segmented polyurethanes with soft segments based ...

  18. Biodegradable polymers derived from amino acids.

    PubMed

    Khan, Wahid; Muthupandian, Saravanan; Farah, Shady; Kumar, Neeraj; Domb, Abraham J

    2011-12-08

    In the past three decades, the use of polymeric materials has increased dramatically for biomedical applications. Many α-amino acids derived biodegradable polymers have also been intensely developed with the main goal to obtain bio-mimicking functional biomaterials. Polymers derived from α-amino acids may offer many advantages, as these polymers: (a) can be modified further to introduce new functions such as imaging, molecular targeting and drugs can be conjugated chemically to these polymers, (b) can improve on better biological properties like cell migration, adhesion and biodegradability, (c) can improve on mechanical and thermal properties and (d) their degradation products are expected to be non-toxic and readily metabolized/excreted from the body. This manuscript focuses on biodegradable polymers derived from natural amino acids, their synthesis, biocompatibility and biomedical applications. It is observed that polymers derived from α-amino acids constitute a promising family of biodegradable materials. These provide innovative multifunctional polymers possessing amino acid side groups with biological activity and with innumerous potential applications.

  19. Diisopropanolamine biodegradation potential at sour gas plants

    SciTech Connect

    Gieg, L.M.; Greene, E.A.; Coy, D.L.; Fedorak, P.M.

    1998-12-31

    The potential for aerobic and anaerobic biodegradation of a sour gas treatment chemical, diisopropanolamine (DIPA), was studied using contaminated aquifer materials from three sour gas treatment sites in western Canada. DIPA was found to be readily consumed under aerobic conditions at 8 C and 28 C in shake flask cultures incubated with aquifer material from each of the sites, and this removal was characterized by first-order kinetics. In addition, DIPA biodegradation was found to occur under nitrate-, Mn(IV)-, and Fe(III)-reducing conditions at 28 C, and in some cases at 8 C, in laboratory microcosms. DIPA loss corresponded to consumption of nitrate, and production of Mn(II) and Fe(II) in viable microcosms compared to corresponding sterile controls. A threshold DIPA concentration near 40 mg/L was observed in the anaerobic microcosms. This report provides the first evidence that DIPA is biodegraded under anaerobic conditions, and the data suggest that biodegradation may contribute to DIPA attenuation under aerobic and anaerobic conditions in aquifers contaminated with this sour gas treatment chemical.

  20. Biodegradable Shape Memory Polymers in Medicine.

    PubMed

    Peterson, Gregory I; Dobrynin, Andrey V; Becker, Matthew L

    2017-09-21

    Shape memory materials have emerged as an important class of materials in medicine due to their ability to change shape in response to a specific stimulus, enabling the simplification of medical procedures, use of minimally invasive techniques, and access to new treatment modalities. Shape memory polymers, in particular, are well suited for such applications given their excellent shape memory performance, tunable materials properties, minimal toxicity, and potential for biodegradation and resorption. This review provides an overview of biodegradable shape memory polymers that have been used in medical applications. The majority of biodegradable shape memory polymers are based on thermally responsive polyesters or polymers that contain hydrolyzable ester linkages. These materials have been targeted for use in applications pertaining to embolization, drug delivery, stents, tissue engineering, and wound closure. The development of biodegradable shape memory polymers with unique properties or responsiveness to novel stimuli has the potential to facilitate the optimization and development of new medical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Neuronal growth and differentiation on biodegradable membranes.

    PubMed

    Morelli, Sabrina; Piscioneri, Antonella; Messina, Antonietta; Salerno, Simona; Al-Fageeh, Mohamed B; Drioli, Enrico; De Bartolo, Loredana

    2015-02-01

    Semipermeable polymeric membranes with appropriate morphological, physicochemical and transport properties are relevant to inducing neural regeneration. We developed novel biodegradable membranes to support neuronal differentiation. In particular, we developed chitosan, polycaprolactone and polyurethane flat membranes and a biosynthetic blend between polycaprolactone and polyurethane by phase-inversion techniques. The biodegradable membranes were characterized in order to evaluate their morphological, physicochemical, mechanical and degradation properties. We investigated the efficacy of these different membranes to promote the adhesion and differentiation of neuronal cells. We employed as model cell system the human neuroblastoma cell line SHSY5Y, which is a well-established system for studying neuronal differentiation. The investigation of viability and specific neuronal marker expression allowed assessment that the correct neuronal differentiation and the formation of neuronal network had taken place in vitro in the cells seeded on different biodegradable membranes. Overall, this study provides evidence that neural cell responses depend on the nature of the biodegradable polymer used to form the membranes, as well as on the dissolution, hydrophilic and, above all, mechanical membrane properties. PCL-PU membranes exhibit mechanical properties that improve neurite outgrowth and the expression of specific neuronal markers.

  2. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  3. Biodegradation of o-Benzyl-p-Chlorophenol

    PubMed Central

    Swisher, R. D.; Gledhill, W. E.

    1973-01-01

    The extent of biodegradation of o-benzyl-p-chlorophenol, marketed as a germicide under the name Santophen® 1 (Monsanto Co.), in river water, sewage, and activated sludge was determined. Biodegradation was assessed by use of a colorimetric procedure for phenolic materials, carbon analysis, and CO2 evolution. In unacclimated river water, 0.1 mg of Santophen 1 per liter was degraded within 6 days. In sewage, 0.5 and 1.0 mg/liter levels of Santophen 1 were degraded in 1 day. Acclimated activated sludge achieved 80% biodegradation of 1.0 mg/liter Santophen 1 in 8 h and 100% in 24 h. When effluent from a semicontinuous activated sludge unit, acclimated to 20 mg of Santophen 1 per liter was used as the inoculum for the CO2 evolution procedure, 60% of the total theoretical CO2 was evolved from Santophen 1. Based on the results of these studies, indicating Santophen 1 to be readily biodegraded in at least four biological systems, the continued use of present levels of Santophen 1 should present no significant environmental problems. PMID:4356462

  4. BIODEGRADATION OF ATRAZINE IN SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    The pesticide atrazine is frequently detected in ground water, including ground water used as drinking water. Little information is available on the fate of atrazine in the subsurface, including its biodegradability. The objectives of this study were to evaluate the biodegradabil...

  5. Phyllosphere yeasts rapidly break down biodegradable plastics

    PubMed Central

    2011-01-01

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands. PMID:22126328

  6. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  7. DEMONSTRATION BULLETIN: SLURRY BIODEGRADATION, International Technology Corporation

    EPA Science Inventory

    This technology uses a slurry-phase bioreactor in which the soil is mixed with water to form a slurry. Microorganisms and nutrients are added to the slurry to enhance the biodegradation process, which converts organic wastes into relatively harmless byproducts of microbial metabo...

  8. In vitro biodegradation behavior, mechanical properties, and cytotoxicity of biodegradable Zn-Mg alloy.

    PubMed

    Gong, Haibo; Wang, Kun; Strich, Randy; Zhou, Jack G

    2015-11-01

    Zinc-Magnesium (Zn-Mg) alloy as a novel biodegradable metal holds great potential in biodegradable implant applications as it is more corrosion resistant than Magnesium (Mg). However, the mechanical properties, biodegradation uniformity, and cytotoxicity of Zn-Mg alloy remained as concerns. In this study, hot extrusion process was applied to Zn-1 wt % Mg (Zn-1Mg) to refine its microstructure. Effects of hot extrusion on biodegradation behavior and mechanical properties of Zn-1Mg were investigated in comparison with Mg rare earth element alloy WE43. Metallurgical analysis revealed significant grain size reduction, and immersion test found that corrosion rates of WE43 and Zn-1Mg were reduced by 35% and 57%, respectively after extrusion. Moreover, hot extrusion resulted in a much more uniform biodegradation in extruded Zn-1Mg alloy and WE43. In vitro cytotoxicity test results indicated that Zn-1Mg alloy was biocompatible. Therefore, hot extruded Zn-1Mg with homogenous microstructure, uniform as well as slow degradation, improved mechanical properties, and good biocompatibility was believed to be an excellent candidate material for load-bearing biodegradable implant application.

  9. In vitro biodegradation behavior, mechanical properties, and cytotoxicity of biodegradable Zn–Mg alloy

    PubMed Central

    Gong, Haibo; Wang, Kun; Strich, Randy; Zhou, Jack G.

    2017-01-01

    Zinc–Magnesium (Zn–Mg) alloy as a novel biodegradable metal holds great potential in biodegradable implant applications as it is more corrosion resistant than Magnesium (Mg). However, the mechanical properties, biodegradation uniformity, and cytotoxicity of Zn–Mg alloy remained as concerns. In this study, hot extrusion process was applied to Zn–1 wt % Mg (Zn–1Mg) to refine its microstructure. Effects of hot extrusion on biodegradation behavior and mechanical properties of Zn–1Mg were investigated in comparison with Mg rare earth element alloy WE43. Metallurgical analysis revealed significant grain size reduction, and immersion test found that corrosion rates of WE43 and Zn–1Mg were reduced by 35% and 57%, respectively after extrusion. Moreover, hot extrusion resulted in a much more uniform biodegradation in extruded Zn–1Mg alloy and WE43. In vitro cytotoxicity test results indicated that Zn–1Mg alloy was biocompatible. Therefore, hot extruded Zn–1Mg with homogenous microstructure, uniform as well as slow degradation, improved mechanical properties, and good biocompatibility was believed to be an excellent candidate material for load-bearing biodegradable implant application. PMID:25581552

  10. Does Bioavailability Limit Biodegradability? A Comparison of Hydrocarbon Biodegradation and Desorption Rates in Aged Soils

    SciTech Connect

    Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons do not need to be transferred into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  11. Does bioavailability limit biodegradation? A comparison of hydrocarbon biodegradation and desorption rates in aged soils.

    PubMed

    Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons apparently do not need to be dissolved into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  12. Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

    PubMed Central

    Mancini, Silvia A.; Ulrich, Ania C.; Lacrampe-Couloume, Georges; Sleep, Brent; Edwards, Elizabeth A.; Sherwood Lollar, Barbara

    2003-01-01

    Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ɛ) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially, C-H bond breakage in the initial step of the anaerobic benzene biodegradation pathway may account for the large fractionation observed compared to that in aerobic benzene biodegradation. Despite some differences in reported enrichment factors between cultures with different terminal-electron-accepting processes, carbon and hydrogen isotope analysis has the potential to provide direct evidence of anaerobic biodegradation of benzene in the field. PMID:12513995

  13. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    PubMed

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  14. Development of biodegradable materials; balancing degradability and performance

    SciTech Connect

    Mayer, J.M.; Allen, A.L.; Dell, P.A.; McCassie, J.E.; Shupe, A.E.; Stenhouse, P.J. Stenhouse, Welch, E.A.; Kaplan, D.L.

    1993-12-31

    The development of biodegradable materials suitable for packaging must take into consideration various performance criteria such as mechanical and barrier properties, as well as rate of biodegradability in given environments. Individual or blended biopolymer films were obtained commercially or blown into film in the laboratory and tested for tensile strength, ultimate elongation and oxygen barrier. These films were then subjected to accelerated marine biodegradation tests as well as simulated marine respirometry. Starch/ethylene vinyl alcohol films exhibited good mechanical and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated and excellent oxygen barrier properties, but were very slow to biodegrade in the simulated marine environment. Polyhydroxyalkanoates had good mechanical properties, average oxygen barrier and good biodegradability. Data indicate that performance and biodegradability of packaging can be tailored to needs by combining individual biopolymers in different proportions in blends and laminates.

  15. Cirque du Monde as a health intervention

    PubMed Central

    Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

    2014-01-01

    Abstract Objective To present Cirque du Soleil’s social circus program, Cirque du Monde, to explore its potential as a primary health care tool for family physicians. Data sources A review of the literature in PubMed, the Cochrane Library, PsycINFO, LaPresse, Eureka, Google Scholar, and Érudit using the key words circus, social circus, Cirque du Monde, and Cirque du Soleil; a Montreal-based initiative, Espace Transition, modeled on Cirque du Monde; and personal communication with Cirque du Soleil’s Social Circus Training Advisor. Study selection The first 50 articles or websites identified for each key word in each of the databases were examined on the basis of their titles and abstracts in the case of articles, and on the basis of their titles and page content in the case of websites. Articles and websites that explored an aspect of social circuses or that described an intervention that involved circuses were then retained for analysis. Because all literature on social circuses was searched, no criterion for year of publication was used. Synthesis No articles on the social circus as a health intervention were found. One study on the use of the circus as an intervention in schools was identified. It demonstrated an increase in self-esteem in the children who took part. One study on the use of the circus in a First Nations community was found; it contained nonspecific, qualitative findings. The other articles identified were merely descriptions of social circuses. One website was identified on the use of the social circus to help youth who had been treated in a hospital setting for major psychiatric disorders to re-enter the community. The team in the pediatric psychiatry department at Centre Hospitalier Universitaire Sainte-Justine, the children’s hospital in Montreal, Que, was contacted; they were leading this project, called Espace Transition. The unpublished preliminary findings of its pilot project demonstrate substantial improvements in overall patient

  16. Improving the biodegradative capacity of subsurface bacteria

    SciTech Connect

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  17. BTEX biodegradation by bacteria from effluents of petroleum refinery.

    PubMed

    Mazzeo, Dânia Elisa Christofoletti; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

    2010-09-15

    Groundwater contamination with benzene, toluene, ethylbenzene and xylene (BTEX) has been increasing, thus requiring an urgent development of methodologies that are able to remove or minimize the damages these compounds can cause to the environment. The biodegradation process using microorganisms has been regarded as an efficient technology to treat places contaminated with hydrocarbons, since they are able to biotransform and/or biodegrade target pollutants. To prove the efficiency of this process, besides chemical analysis, the use of biological assessments has been indicated. This work identified and selected BTEX-biodegrading microorganisms present in effluents from petroleum refinery, and evaluated the efficiency of microorganism biodegradation process for reducing genotoxic and mutagenic BTEX damage through two test-systems: Allium cepa and hepatoma tissue culture (HTC) cells. Five different non-biodegraded BTEX concentrations were evaluated in relation to biodegraded concentrations. The biodegradation process was performed in a BOD Trak Apparatus (HACH) for 20 days, using microorganisms pre-selected through enrichment. Although the biodegradation usually occurs by a consortium of different microorganisms, the consortium in this study was composed exclusively of five bacteria species and the bacteria Pseudomonas putida was held responsible for the BTEX biodegradation. The chemical analyses showed that BTEX was reduced in the biodegraded concentrations. The results obtained with genotoxicity assays, carried out with both A. cepa and HTC cells, showed that the biodegradation process was able to decrease the genotoxic damages of BTEX. By mutagenic tests, we observed a decrease in damage only to the A. cepa organism. Although no decrease in mutagenicity was observed for HTC cells, no increase of this effect after the biodegradation process was observed either. The application of pre-selected bacteria in biodegradation processes can represent a reliable and

  18. Biodegradable naphthenic acid ionic liquids: synthesis, characterization, and quantitative structure-biodegradation relationship.

    PubMed

    Yu, Yinghao; Lu, Xingmei; Zhou, Qing; Dong, Kun; Yao, Hongwei; Zhang, Suojiang

    2008-01-01

    It has been confirmed that commonly used ionic liquids are not easily biodegradable. When ultimately disposed of or accidentally released, they would accumulate in the environment, which strongly restricts large-scale industrial applications of ionic liquids. Herein, ten biodegradable ionic liquids were prepared by a single, one-pot neutralization of choline and surrogate naphthenic acids. The structures of these naphthenic acid ionic liquids (NAILs) were characterized and confirmed by (1)H and (13)C NMR spectroscopy, IR spectroscopy, and elemental analysis, and their physical properties, such as densities, viscosities, conductivities, melting points (T(m)), glass transition points (T(g)), and the onset temperatures of decomposition (T(d)), were determined. More importantly, studies showed that these NAILs would be rapidly and completely biodegraded in aquatic environments under aerobic conditions, which would make them attractive candidates to be utilized in industrial processes. To explore the underlying mechanism involved in the NAIL biodegradation reaction and seek prediction of their biodegradability under environmental conditions, four molecular descriptors were chosen: the logarithm of the n-octanol/water partition coefficient (log P), van der Waals volume (V(vdW)), energies of the highest occupied molecular orbital (E(HOMO)), and energies of the lowest unoccupied molecular orbital (E(LUMO)). Through multiple linear regression, a general and qualified model including the biodegradation percentage for NAILs after the 28-day OECD 301D test (%B(28)) and molecular descriptors was developed. Regression analysis showed that the model was statistically significant at the 99 % confidence interval, thus indicating that the %B(28) of NAILs could be explained well by the quantum chemical descriptor E(HOMO), which might give some important clues in the discovery of biodegradable ionic liquids of other kinds.

  19. Cri du Chat: report of a case.

    PubMed

    Sparks, S; Hutchinson, B

    1980-01-01

    Since Lejeune et al. (1963) first described the syndrome of Cri du Chat (Cry of the Cat), cases have been described in the literature in terms of genetic abnormalities. All cases were severely retarded and the mental impairment has been believed to be progressive, although no longitudinal studies have been reported. Descriptions of speech and language behavior have been scarce. This paper presents a case of a 7-yr, 6 mo-old girl with Cri du Chat who has received speech and language therapy for five years. Her speech, language, and mental development are noted and are not consistent with cases reported previously.

  20. Atomes du big bang : premiere detection

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    1994-09-01

    Ce fut au Keck d'ouvrir le bal, en debusquant du deuterium a plus de 10 milliards d'annees-lumiere. Puis, en juillet, vint l'annonce qu'Hubble avait apercu de l'helium flottant dans le milieu intergalactque lontain. Que ces deux prouesses realisees a la lumiere de quasars se confirment et elles ouvriraient enfin la chasse aux atomes primordiaux nes dans les trois premieres minutes de l'Univers. Avec toutefois un probleme : l'une apporterait de l'eau au moulin du Big Bang, mais l'autre ferait plutot figure de pave dans la mare ...

  1. Current knowledge on biodegradable microspheres in drug delivery.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

    2015-08-01

    Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

  2. [Biodegradable catheters and urinary stents. When?

    PubMed

    Soria, F; Morcillo, E; López de Alda, A; Pastor, T; Sánchez-Margallo, F M

    2016-10-01

    One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a

  3. Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions.

    PubMed

    Mohee, R; Unmar, G D; Mudhoo, A; Khadoo, P

    2008-01-01

    A study was conducted on two types of plastic materials, Mater-Bi Novamont (MB) and Environmental Product Inc. (EPI), to assess their biodegradability under aerobic and anaerobic conditions. For aerobi