1
|
Li ASW, Marikawa Y. Methoxyacetic acid inhibits histone deacetylase and impairs axial elongation morphogenesis of mouse gastruloids in a retinoic acid signaling-dependent manner. Birth Defects Res 2020; 112:1043-1056. [PMID: 32496642 DOI: 10.1002/bdr2.1712] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Teratogenic potential has been linked to various industrial compounds. Methoxyacetic acid (MAA) is a primary metabolite of the widely used organic solvent and plasticizer, methoxyethanol and dimethoxyethyl phthalate, respectively. Studies using model animals have shown that MAA acts as the proximate teratogen that causes various malformations in developing embryos. Nonetheless, the molecular mechanisms by which MAA exerts its teratogenic effects are not fully understood. METHODS Gastruloids of mouse P19C5 pluripotent stem cells, which recapitulate axial elongation morphogenesis of gastrulation-stage embryos, were explored as an in vitro model to investigate the teratogenic action of MAA. Morphometric parameters of gastruloids were measured to evaluate the morphogenetic effect, and transcript levels of various developmental regulator genes were examined to assess the impact on gene expression patterns. The effects of MAA on the level of retinoic acid (RA) signaling and histone deacetylase activity were also measured. RESULTS MAA reduced axial elongation of gastruloids at concentrations comparable to the teratogenic plasma level (5 mM) in vivo. MAA at 4 mM significantly altered the expression profiles of developmental regulator genes. In particular, it upregulated the RA signaling target genes. The concomitant suppression of RA signaling using a pharmacological agent alleviated the morphogenetic effect of MAA. MAA at 4 mM also significantly reduced the activity of purified histone deacetylase protein. CONCLUSIONS MAA impaired axial elongation morphogenesis in a RA signaling-dependent manner in mouse gastruloids, possibly through the inhibition of histone deacetylase.
Collapse
Affiliation(s)
- Aileen S W Li
- Developmental and Reproductive Biology Graduate Program, Institute for Biogenesis Research, University of Hawaii John A. Burns School of Medicine, Honolulu, Hawaii, USA
| | - Yusuke Marikawa
- Developmental and Reproductive Biology Graduate Program, Institute for Biogenesis Research, University of Hawaii John A. Burns School of Medicine, Honolulu, Hawaii, USA
| |
Collapse
|
2
|
Starek-Świechowicz B, Miranowicz-Dzierżawska K, Szymczak W, Budziszewska B, Starek A. Hematological effects of exposure to mixtures of selected ethylene glycol alkyl ethers in rats. Pharmacol Rep 2012; 64:166-78. [PMID: 22580533 DOI: 10.1016/s1734-1140(12)70743-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/23/2011] [Indexed: 11/16/2022]
Abstract
Exposure to various ethylene glycol monoalkyl ethers (EGAEs) is known to result in hemolytic effect caused by their metabolites, appropriate alkoxyacetic acids, generated via both alcohol dehydrogenase and aldehyde dehydrogenase. It has been shown in many studies that administration of single doses of EGAEs to rats lead to dose- and time-dependent hemolytic anemia. The repeated exposure to isopropoxyethanol (IPE), and butoxyethanol (BE), contrary to methoxyethanol (ME) and ethoxyethanol (EE), resulted in significantly less pronounced hematological changes. While the majority of hematological effects were dramatic at the beginning of the exposure, later these changes clearly regressed despite continued weekly exposure to these ethers. The gradual recovery from the hemolytic anemia may be associated with tolerance development to the hemolytic effect of IPE and BE. ME demonstrated high hematotoxicity, which increased progressively and reached a maximum at the end of 4 week exposure, whereas EE revealed moderate hematological effects. It might be suspected that ME and EE may modified of IPE hemolytic activity in rats simultaneously treated with these compounds. In the rats co-exposed to IPE and ME subcutaneously at a relatively low doses of 0.75 mM + 0.75 mM for 4 weeks, a significantly less pronounced hematological changes at the beginning of the exposure in comparison with animals treated with IPE (0.75 mM) alone were observed. At the later period, i.e., at the end of 4 weeks exposure, the hematological alterations in the same animals were markedly pronounced and progressively elevated with exposure time, except for mean corpuscular volume (MCV) values, which were significantly lower in comparison with IPE group. ME at the higher dose of 1.25 mM/kg and EE at both doses of 0.75 and 1.25 mM/kg did not modify the hematotoxicity of IPE (at doses of 0.75 mM and 1.25 mM) at the beginning of the exposure, whereas increased its harmful effects at the end of the treatment. The amelioration in the majority of the hematological parameters at the beginning of the exposure may be caused by inhibitory effect of ME on IPE metabolism. On the contrary, an accumulation of the methoxyacetic acid and ethoxyacetic acid, toxic metabolites of ME and EE, respectively, and no tolerance development to the hemolytic effect of these two chemicals may be responsible for elevated hematological alterations at the end of the exposure.
Collapse
Affiliation(s)
- Beata Starek-Świechowicz
- Department of Biochemical Toxicology, Medical College, Jagiellonian University, Medyczna 9, PL 30-688 Kraków, Poland
| | | | | | | | | |
Collapse
|
3
|
Lam CW, Lim SR, Schoenung JM. Environmental and risk screening for prioritizing pollution prevention opportunities in the U.S. printed wiring board manufacturing industry. JOURNAL OF HAZARDOUS MATERIALS 2011; 189:315-322. [PMID: 21398034 DOI: 10.1016/j.jhazmat.2011.02.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 02/12/2011] [Accepted: 02/14/2011] [Indexed: 05/30/2023]
Abstract
Modern manufacturing of printed wiring boards (PWBs) involves extensive use of various hazardous chemicals in different manufacturing steps such as board preparation, circuit design transfer, etching and plating processes. Two complementary environmental screening methods developed by the U.S. EPA, namely: (i) the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) and (ii) Risk-Screening Environmental Indicators (RSEI), are used to quantify geographic and chemical environmental impacts in the U.S. PWB manufacturing industry based on Toxics Release Inventory (TRI) data. Although the release weight percentages of industrial chemicals such as methanol, glycol ethers and dimethylformamide comprise the larger fraction of reported air and water emissions, results indicate that lead, copper and their compounds' releases correspond to the highest environmental impact from toxicity potentials and risk-screening scores. Combining these results with further knowledge of PWB manufacturing, select alternative chemical processes and materials for pollution prevention are discussed. Examples of effective pollution prevention options in the PWB industry include spent etchant recovery technologies, and process and material substitutions. In addition, geographic assessment of environmental burden highlights states where promotion of pollution prevention strategies and emissions regulations can have the greatest effect to curb the PWB industry's toxic release impacts.
Collapse
Affiliation(s)
- Carl W Lam
- Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, USA
| | | | | |
Collapse
|
4
|
Bagchi G, Zhang Y, Waxman DJ. Impact of methoxyacetic acid on mouse Leydig cell gene expression. Reprod Biol Endocrinol 2010; 8:65. [PMID: 20565877 PMCID: PMC2909983 DOI: 10.1186/1477-7827-8-65] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2010] [Accepted: 06/18/2010] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Methoxyacetic acid (MAA) is the active metabolite of the widely used industrial chemical ethylene glycol monomethyl ether, which is associated with various developmental and reproductive toxicities, including neural toxicity, blood and immune disorders, limb degeneration and testicular toxicity. Testicular toxicity is caused by degeneration of germ cells in association with changes in gene expression in both germ cells and Sertoli cells of the testis. This study investigates the impact of MAA on gene expression in testicular Leydig cells, which play a critical role in germ cell survival and male reproductive function. METHODS Cultured mouse TM3 Leydig cells were treated with MAA for 3, 8, and 24 h and changes in gene expression were monitored by genome-wide transcriptional profiling. RESULTS A total of 3,912 MAA-responsive genes were identified. Ingenuity Pathway analysis identified reproductive system disease, inflammatory disease and connective tissue disorder as the top biological functions affected by MAA. The MAA-responsive genes were classified into 1,366 early responders, 1,387 mid-responders, and 1,138 late responders, based on the time required for MAA to elicit a response. Analysis of enriched functional clusters for each subgroup identified 106 MAA early response genes involved in transcription regulation, including 32 genes associated with developmental processes. 60 DNA-binding proteins responded to MAA rapidly but transiently, and may contribute to the downstream effects of MAA seen for many mid and late response genes. Genes within the phosphatidylinositol/phospholipase C/calcium signaling pathway, whose activity is required for potentiation of nuclear receptor signaling by MAA, were also enriched in the set of early MAA response genes. In contrast, many of the genes responding to MAA at later time points encode membrane proteins that contribute to cell adhesion and membrane signaling. CONCLUSIONS These findings on the progressive changes in gene expression induced by MAA in a cultured Leydig cell model may help elucidate signaling pathways that lead to the testicular pathophysiological responses induced by MAA exposure and may identify useful biomarkers of MAA toxicity.
Collapse
Affiliation(s)
- Gargi Bagchi
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, USA
| | - Yijing Zhang
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, USA
| | - David J Waxman
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, USA
| |
Collapse
|
5
|
Bagchi G, Hurst CH, Waxman DJ. Interactions of methoxyacetic acid with androgen receptor. Toxicol Appl Pharmacol 2008; 238:101-10. [PMID: 18486176 DOI: 10.1016/j.taap.2008.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/28/2008] [Accepted: 03/24/2008] [Indexed: 01/11/2023]
Abstract
Endocrine disruptive compounds (EDC) alter hormone-stimulated, nuclear receptor-dependent physiological and developmental processes by a variety of mechanisms. One recently identified mode of endocrine disruption is through hormone sensitization, where the EDC modulates intracellular signaling pathways that control nuclear receptor function, thereby regulating receptor transcriptional activity indirectly. Methoxyacetic acid (MAA), the primary, active metabolite of the industrial solvent ethylene glycol monomethyl ether and a testicular toxicant, belongs to this EDC class. Modulation of nuclear receptor activity by MAA could contribute to the testicular toxicity associated with MAA exposure. In the present study, we evaluated the impact of MAA on the transcriptional activity of several nuclear receptors including the androgen receptor (AR), which plays a pivotal role in the development and maturation of spermatocytes. AR transcriptional activity is shown to be increased by MAA through a tyrosine kinase signaling pathway that involves PI3-kinase. In a combinatorial setting with AR antagonists, MAA potentiated the AR response without significantly altering the EC(50) for androgen responsiveness, partially alleviating the antagonistic effect of the anti-androgens. Finally, MAA treatment of TM3 mouse testicular Leydig cells markedly increased the expression of Cyp17a1 and Shbg while suppressing Igfbp3 expression by ~90%. Deregulation of these genes may alter androgen synthesis and action in a manner that contributes to MAA-induced testicular toxicity.
Collapse
Affiliation(s)
- Gargi Bagchi
- Division of Cell and Molecular Biology, Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA
| | | | | |
Collapse
|
6
|
Starek A, Szymczak W, Zapor L. Hematological effects of four ethylene glycol monoalkyl ethers in short-term repeated exposure in rats. Arch Toxicol 2007; 82:125-36. [PMID: 17874071 DOI: 10.1007/s00204-007-0236-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 08/07/2007] [Indexed: 10/22/2022]
Abstract
This study was carried out to compare the hematological effects of 2-methoxyethanol (ME), 2-ethoxyethanol (EE), 2-isopropoxyethanol (IPE), and 2-butoxyethanol (BE) in short-term studies in rats. Male rats were subcutaneously treated with ME or EE at a dosage of 0, 1.25, 2.5 and 5.0 mM/kg in saline, 5 days per week, for 4 weeks. Other rats were exposed to IPE or BE at doses of 0, 0.25, 0.5, 0.75 and 1.25 mM/kg in the same manner. Administration of each chemical, except of ME, resulted in a time- and dose-dependent swelling of erythrocytes as evidenced by an increase in mean corpuscular volume (MCV). Subsequently, red blood cells (RBC), packed cell volumes (PCV), hemoglobin concentration (HGB), and mean cell hemoglobin concentration (MCHC) decreased. Furthermore, an increase in mean cell hemoglobin (MCH) and reticulocyte counts was observed. The onset of hemolysis induced by EE, IPE or BE was faster than after ME administration. While in rats exposed to ME hematological changes were strongly pronounced and progressively increased with exposure time beginning from the day 11, those in animals treated with EE were rather persisted at low constant level for all exposure period. In contrast, the rats exposed to IPE and BE demonstrated the dramatic hematological changes more pronounced in case of BE than IPE at the beginning of exposure (on day 4). Despite of exposure duration, these changes were regressed, although the decrease in RBC and MCHC and the increase in MCV and MCH in rats treated with highest doses of both compound (0.5, 0.75, and 1.25 mM/kg) were more persistent, probably due to selective hemolysis of the aged erythrocytes. In addition, significant leukopenia due to reduction of lymphocytes in rats exposed to ME was observed. In summary, this study demonstrated no tolerance to ME- and EE-induced intravascular hemolysis developed under these experimental conditions. On the contrary, tolerance to IPE- and BE-induced hemolysis in rats exposed to these compounds was prompted.
Collapse
Affiliation(s)
- Andrzej Starek
- Department of Biochemical Toxicology, Medical College, Jagiellonian University, Krakow, Poland.
| | | | | |
Collapse
|
7
|
Chen HI, Liou SH, Hsieh MH, Shih TS, Sun CW, Wu TN, Chang HY, Loh CH. Hematological Follow‐up of an Intervention Program Adding Rubber Glove‐Wearing to Local Ventilation for 2‐Ethoxyethanol Acetate‐Exposed Workers. J Occup Health 2007; 49:285-93. [PMID: 17690522 DOI: 10.1539/joh.49.285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The objective of this study was to evaluate an intervention program, implemented in year 1999, of wearing rubber gloves in addition to engineering control, and to follow-up the hematological effects of 2-ethoxyethanol acetate (2-EEA) exposure among workers in a silk-screening factory. All workers from the printing department with direct exposure to 2-EEA were recruited as the exposed group. Workers from the other departments were recruited as the comparison group. Hematological parameters were measured during health surveys conducted 3 times every two years. Information on personal characteristics and working habits was obtained through a structured questionnaire. More female workers were involved in manual printing resulting in higher exposure to 2-EEA. Hemoglobin and haematocrit levels in female exposed workers were significantly lower than those of female comparison workers in the 1st (1998) health survey, but not in the 2nd (2000) and 3rd (2002) health surveys. No difference was found between male exposed and comparison workers for all three surveys. Longitudinal analysis after adjusting for confounders using the general estimating equation model showed the hemoglobin, haematocrit, and RBC count were significantly higher for 2-EEA exposed workers than comparison workers across the 3 surveys (n=42). The results show that wearing rubber gloves in addition to local ventilation was effective at preventing direct dermal exposure to 2-EEA and ameliorated the hematological effects of 2-EEA exposure.
Collapse
Affiliation(s)
- Hong-I Chen
- Department of Surgery, Tri-Service General Hospital, and Institute of Occupational Safety and Health, Kaohsiung Medical University, Taipei, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Yokota K, Ueno H, Ikeda N, Johyama Y, Michitsuji H, Yamada S. Correlation between urinary methoxyacetic acid and exposure of ethylene glycol dimethyl ether in a lithium battery plant. Int Arch Occup Environ Health 2007; 81:123-6. [PMID: 17492304 DOI: 10.1007/s00420-007-0198-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Accepted: 04/17/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To examine the correlation between airborne ethylene glycol dimethyl ether (EGdiME) exposures and the urinary methoxyacetic acid (MAA) and to approach the issue of a permissible exposure limit for EGdiME. METHODS The survey was conducted on Thursday. Workers occupationally exposed to EGdiME, as well as nonexposed controls, were studied in combination with one of the authors, who was coincidentally exposed to EGdiME while carrying out the study. Air levels of EGdiME were determined by personal sampling on passive gas tubes. Urine was collected from nine control subjects and ten workers immediately before and after the shift, and from one of the authors at intervals during 12 h. The analyses of EGdiME in air and MAA in urine were performed by gas chromatography with flame ionization detection. RESULTS The time-weighted average (TWA) air levels of EGdiME ranged from 0.7 to 10.5 ppm during 8 h work shifts. The urinary levels of MAA in one of the authors increased continuously during exposure and after the end of exposure. The levels of urinary MAA in the exposed workers were significantly higher than those in the control subjects. On the other hand, the postshift values were higher than the preshift values in the exposed workers, but the difference was not significant. A linear correlation was found between the TWA air levels of EGdiME and creatinine-adjusted MAA levels in urine collected at the end of the shift (r = 0.933; P < 0.0001). According to our equation, a linear extrapolation to the biological limit value recommended by Shih et al. (1999) of 40 mg MAA/g crea indicated an average inhalation exposure to EGdiME over the workweek of 12 ppm. CONCLUSIONS These results indicate that the determination of MAA in urine is suitable for use in the biological monitoring of EGdiME exposure.
Collapse
Affiliation(s)
- Kozo Yokota
- Matsushita Science Center of Industrial Hygiene, 7-6 Tonoshima-cho, Kadoma, Osaka 571-0045, Japan.
| | | | | | | | | | | |
Collapse
|
9
|
Shih TS, Wu KY, Chen HI, Chang CP, Chang HY, Huang YS, Liou SH. The development and regulation of occupational exposure limits in Taiwan. Regul Toxicol Pharmacol 2006; 46:142-8. [PMID: 16701932 DOI: 10.1016/j.yrtph.2006.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Indexed: 10/24/2022]
Abstract
The occupational exposure limits (OELs) in Taiwan was promulgated in 1974 and has been revised five times since then. Many of the OELs were adopted from the most recent ACGIH TLVs and US OSHA PELs. A total of 483 chemicals were listed in the current Taiwan OELs Standard. The procedures of OELs development in Taiwan include the IOSH organized a recommended exposure limits (RELs) Committee to select the target chemicals and to recommend the RELs through literature review based on the health effects in the first stage, then, the CLA put policy needs, economical and technical feasibility into consideration and set up the final OELs at the second stage. A standard operation manual of RELs Committee has been developed. Based on our experience, several issues including the participation of representatives from a comprehensive spectrum, communication/education and training/enforcement, continuous collection of the local exposure data and health hazard information, use of health risk assessment, consideration of economic, and technical feasibility, as well as the globalization and information and experience sharing are critical in developing the appropriate OELs. Three examples including benzene, crystalline silica, and 2-methoxy ethanol are given to demonstrate the operation of system.
Collapse
Affiliation(s)
- Tung-Sheng Shih
- Institute of Occupational Safety and Health, Council of Labor Affairs, No 99, Lane 407, Heng-Ke Rd., Sijhih City, Taipei, Taiwan
| | | | | | | | | | | | | |
Collapse
|
10
|
Yokota K, Ikeda N, Johyama Y, Michitsuji H, Yamada S. Urinary methoxyacetic acid as an indicator of occupational exposure to ethylene glycol dimethyl ether. Int Arch Occup Environ Health 2005; 78:650-4. [PMID: 16001212 DOI: 10.1007/s00420-005-0014-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 05/23/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE To investigate whether methoxyacetic acid (MAA) is the metabolite of ethylene glycol dimethyl ether (EGdiME) in humans and whether its metabolite in urine can be used as a biomarker for exposure to EGdiME. METHODS Workers occupationally exposed to EGdiME, as well as nonexposed controls, were studied. Urine samples were collected from 20 control subjects and, on Friday postshift, from 14 workers. The identification and quantification of the metabolite were performed by gas chromatography/mass spectrometry (GC/MS) and GC/FID, respectively. Air samples were collected on activated charcoal tubes by area sampling with battery-operated pumps. The glycol ether was analyzed by GC/FID. RESULTS GC/MS clearly showed the metabolite of EGdiME to be MAA. Urinary MAA levels in the control subjects (background levels) were 0.0-0.3 mg/g crea. The levels of urinary MAA in the solvent-exposed workers were significantly (P<0.0001) higher than those in the control subjects. In the eight workers exposed to an average of 0.3 ppm of EGdiME and the six workers exposed to an average of 2.9 ppm, the mean urinary MAA level was 1.08 (range 0.6-1.5) mg/g crea and 9.33 (range 5.7-18.1) mg/g crea, respectively. These results can be explained by differences in the exposure intensity. CONCLUSIONS Our results suggest that MAA is the metabolite of EGdiME, and that MAA in urine may be used for biological monitoring of EGdiME exposures.
Collapse
Affiliation(s)
- Kozo Yokota
- Matsushita Science Center of Industrial Hygiene, Kadoma, Osaka, 571-0045, Japan,
| | | | | | | | | |
Collapse
|
11
|
Fischer A, Hahn C. Biotic and abiotic degradation behaviour of ethylene glycol monomethyl ether (EGME). WATER RESEARCH 2005; 39:2002-7. [PMID: 15878604 DOI: 10.1016/j.watres.2005.03.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Revised: 11/30/2004] [Accepted: 03/02/2005] [Indexed: 05/02/2023]
Abstract
Glycol ethers are widely used in many processes in the chemical industry. Their high water solubility means they are used as solvents for different purposes (e.g. lacquers and varnishes). Since glycol ethers are known to produce toxic metabolites such as the teratogenic methoxyacetic acid during biodegradation, the biological treatment of glycol ethers can be hazardous. However, using oxidizing agents like hydrogen peroxide could be a feasible option for treating wastewater containing glycol ether. In this study, both-, biodegradation and abiotic oxidation experiments with ethylene glycol monomethyl ether (EGME) as contaminant were performed. The biodegradation experiments were conducted with a synthetic model wastewater containing 15 wt% NaCl and 5000 mgl(-1) of EGME. While experiments with the fungus Aspergillus versicolor resulted in the exhaustive biotic degradation of EGME, the toxic metabolite methoxyacetic acid (MAA) was produced as a 'dead end' product. Sodium hydroxide was added to adjust the decreasing pH caused by the production of MAA. In abiotic degradation experiments with EGME, other degradation products--organic acids and toxic aldehydes, e.g. methoxy acetaldehyde (MALD)--were detected. It must be taken into account that EGME and its biotic and abiotic degradation products are usually not analysed in routine wastewater measurements owing to their physical properties.
Collapse
Affiliation(s)
- A Fischer
- Institute of Waste Management and Contaminated Site Treatment, Dresden University of Technology, Pratzschwitzer Str. 15, D-01796 Pirna, Germany
| | | |
Collapse
|
12
|
Chang HY, Lin CC, Shih TS, Chan H, Chou JS, Huang YS. Evaluation of the protective effectiveness of gloves from occupational exposure to 2-methoxyethanol using the biomarkers of 2-methoxyacetic acid levels in the urine and plasma. Occup Environ Med 2004; 61:697-702. [PMID: 15258277 PMCID: PMC1740814 DOI: 10.1136/oem.2003.011171] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To evaluate the protective effectiveness of gloves from occupational exposure to 2-methoxyethanol (2-ME); and to examine the association of 2-methoxyacetic acid (MAA) in urine and plasma collected simultaneously from low 2-ME exposure and high 2-ME exposure workers in a semiconductor copper laminate circuit board manufacturing plant. METHODS Eight hour time weighted breathing zone monitoring was performed to verify the 2-ME exposure classification between workers in regular and special operations. Urine and plasma samples were simultaneously collected from 74 exposed and 80 non-exposed workers. MAA concentrations in the urine (UMAA) and plasma (PMAA) were measured using previously published methods. Three types of gloves worn by workers (cotton, rubber, and no gloves) were recorded by direct observations in the workplace and validated by person-to-person interview. Protective effectiveness indices (PEI) were used to evaluate the glove effectiveness. RESULTS There was no detectable 2-ME/MAA in the air, or in urine and plasma samples in non-exposed workers. The average UMAA and PMAA in special operations were 72.63 mg/g Cr. and 29.72 mg/l, significantly higher than values in regular operations (5.44 mg/g Cr. and 2.58 mg/l, respectively). PMAA showed satisfactory correlation to UMAA in all participants from both regular and special operations. The rubber gloves provided significant reduction in 2-ME uptake, whereas cotton gloves provided little protection with fluctuating effectiveness, based on PEI estimates. CONCLUSIONS PMAA, similar to UMAA, could serve as a specific biomarker for 2-ME exposure. Wearing impermeable rubber gloves during high risk tasks can reduce major 2-ME exposure. Other improvements, including engineering control, should be provided to diminish worker exposure to 2-ME in occupational environments.
Collapse
Affiliation(s)
- H-Y Chang
- Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC
| | | | | | | | | | | |
Collapse
|
13
|
Jansen MS, Nagel SC, Miranda PJ, Lobenhofer EK, Afshari CA, McDonnell DP. Short-chain fatty acids enhance nuclear receptor activity through mitogen-activated protein kinase activation and histone deacetylase inhibition. Proc Natl Acad Sci U S A 2004; 101:7199-204. [PMID: 15103026 PMCID: PMC406489 DOI: 10.1073/pnas.0402014101] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In this study, we demonstrate that the pervasive xenobiotic methoxyacetic acid and the commonly prescribed anticonvulsant valproic acid, both short-chain fatty acids (SCFAs), dramatically increase cellular sensitivity to estrogens, progestins, and other nuclear hormone receptor ligands. These compounds do not mimic endogenous hormones but rather act to enhance the transcriptional efficacy of ligand activated nuclear hormone receptors by up to 8-fold in vitro and in vivo. Detailed characterization of their mode of action revealed that these SCFAs function as both activators of p42/p44 mitogen-activated protein kinase and as inhibitors of histone deacetylases at doses that parallel known exposure levels. Our results define a class of compounds that possess a dual mechanism of action and function as hormone sensitizers. These findings prompt an evaluation of previously unrecognized drug-drug interactions in women who are administered exogenous hormones while exposed to certain xenobiotic SCFAs. Furthermore, our study highlights the need to structure future screening programs to identify additional hormone sensitizers.
Collapse
Affiliation(s)
- Michelle S Jansen
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | | | |
Collapse
|
14
|
Loh CH, Shih TS, Liou SH, Lin YC, Hsieh AT, Chen CY, Liao GD. Haematological effects among silk screening workers exposed to 2-ethoxy ethyl acetate. Occup Environ Med 2003; 60:E7. [PMID: 12937203 PMCID: PMC1740620 DOI: 10.1136/oem.60.9.e7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND 2-Ethoxy ethyl acetate (2-EEA) is a solvent with broad industrial and commercial applications. It has been reported to cause hematological toxicity, infertility, and teratogenesis. AIMS To investigate the haematological effects in 2-EEA exposed workers. METHODS Workers from one silk screening shop (n = 29), using 2-EEA as the major cleaning and printing solvent, were recruited as a high exposure group. Workers with indirect and non-exposure to 2-EEA (n = 56) were recruited as the comparison group. Venous blood was collected for blood routine examination. Air concentration of 2-EEA in this plant was measured by eight hour personal sampling. RESULTS The geometric mean (GM) of air concentration of 2-EEA in the high exposure group was 7.41 ppm (range 1.35-16.5 pppm). The mean exposure of female workers (GM = 9.34 ppm) was significantly higher than that of male workers (GM = 4.87 ppm). The GM of air 2-EEA concentration in the comparison group was 0.07 ppm (range: non-detectable to 3.62 ppm, n = 26). The haemoglobin and haematocrit in the female high 2-EEA exposure workers were significantly lower than those of female workers in the comparison group. No difference was found between male 2-EEA high exposure and comparison group workers. The haemoglobin, haematocrit, and RBC count in the study population had a significant dose-response relation with air 2-EEA levels. CONCLUSION Results suggest that 2-EEA is a haematological toxicant, which leads to anaemic status in high exposure female workers.
Collapse
Affiliation(s)
- C-H Loh
- Department of Family Medicine & Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, 325 Cheng-Kung Road, Sec. 2, Nei-Hu, Taipei, Taiwan 114, ROC.
| | | | | | | | | | | | | |
Collapse
|
15
|
El-Zein RA, Abdel-Rahman SZ, Morris DL, Legator MS. Exposure to ethylene glycol monomethyl ether: clinical and cytogenetic findings. ARCHIVES OF ENVIRONMENTAL HEALTH 2002; 57:371-6. [PMID: 12530607 DOI: 10.1080/00039890209601424] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Glycol ethers are known reproductive and developmental toxins in laboratory animals, but little is known about their genotoxic effects in humans. In the current article, the authors tested the hypothesis that human in utero exposure to ethylene glycol monomethyl ether (EGME) is associated with the development of specific congenital anomalies and elevated levels of chromosome aberrations. The authors conducted a clinical and cytogenetic evaluation of 41 offspring of 28 females occupationally exposed to EGME for an average duration of 4.6 yr. Six offspring of 5 women who were occupationally exposed to EGME during pregnancy exhibited characteristic dysmorphic features that were not observed in 35 offspring of 23 women who worked in the same facility, but who were not pregnant at the time of exposure. Persistent cytogenetic damage was observed exclusively in all 6 in-utero-exposed offspring, but not in their 12 match non-in-utero-exposed controls. The study characterizes EGME as a human teratogen, as indicated by the prevalence of characteristic dysmorphic features and persistent cytogenetic damage in individuals exposed in utero to this chemical.
Collapse
Affiliation(s)
- Randa A El-Zein
- Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | | | | | | |
Collapse
|