Sensitivity to diaminodiphenylmethane.
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Allergens↗
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Results for “Benzhydryl Compounds”
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Occupational hepatitis caused by methylenedianiline.
Four of the six workmen who were engaged in laying an epoxy resin based floor developed an acute hepatic illness; in two of these men, the illness recurred on re-exposure a few months later, and their convalescence period was prolonged. It was concluded that methylenedianiline, which was used as the curing agent for the epoxy resin, was the likely hepatotoxin on the basis of marked similarities of these men's symptoms and signs to those described in other published reports about toxic exposure to this compound. To date, there is no evidence of long-term liver damage caused by this widely used industrial chemical.
Adult↗
Yellow staining of skin among plastics workers.
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Aniline Compounds↗
The relative safety of gamma-ray, autoclave, and ethylene oxide gas sterilization of thermosetting polyurethane.
Sterilization of polyurethane (PU) produces 4,4'-methylenedianiline (MDA), a known carcinogen, and various other compounds. The relationships of the components of PU to the formation of these compounds by sterilization were studied. Specimens of PU fabricated from different combinations of isocyanates and polyols were obtained from dialyzers. The molecular weight of the particular polyol was found to influence the production of MDA by sterilization. Sterilization also produced many unidentified compounds. MDA production was not always associated with the production of the other compounds. Compared with gamma-ray irradiation and ethylene oxide gas (EOG) sterilization, autoclave sterilization eluted more hydrophilic compounds. This phenomenon was significant for PUs produced from smaller-molecular-weight polyols. The combination of autoclave sterilization and a PU produced from a larger-molecular-weight polyol is recommended to minimize the production of potentially toxic compounds. Of the techniques studied, EOG sterilization produced the least amounts of MDA and the other compounds, but the residue of EOG is itself problematic. The risk posed by the amounts of MDA extracted was not significant, but the biological safety of the other compounds remains to be determined.
Aniline Compounds↗
Evaluation of the treatment efficiencies of paper mill whitewaters in terms of organic composition and toxicity.
The efficiency of several lab scale treatments (aerobic, anaerobic and ozone or combination of these) was evaluated using two packaging board mill whitewaters. The effect of the different treatments on the elimination of the organic load, the chemical oxygen demand (COD) and the toxicity was tested as well as the relationship between these parameters. Biocides, phenolic compounds, surfactants, plasticiziers and wood extractives were identified in untreated and treated whitewaters by liquid chromatography coupled with mass spectrometry (LC-MS) or gas chromatography coupled with mass spectrometry (GC-MS). A strong dependency on the water type and treatment efficiency was observed, being the combination of anaerobic and aerobic treatments the best option to reduce the organic contaminants in these waters, although in some cases, the toxicity did not decrease. However, ozone as post-treatment permitted a further reduction of organic compounds, toxicity and COD.
Abietanes↗
High concentrations of bisphenol A induce cell growth and prolactin secretion in an estrogen-responsive pituitary tumor cell line.
PR1 cells are a prolactin (PRL)-secreting cell line derived from pituitary lactotroph tumors found in 17beta-estradiol (E(2))-treated female Fischer 344 rats. Recently, we reported that as little as 0. 01 pM E(2) could induce half-maximal cell proliferation, whereas the antiestrogen ICI 182,780 (ICI) inhibited proliferation. Interestingly, the cell proliferation response is 1000-fold more sensitive to E(2) than the PRL response (induction of prolactin protein synthesis), suggesting that there is a distinction between cell proliferation and the PRL response in PR1 cells. Bisphenol A (BPA) is a monomer of plastics and epoxy resins that is widely used in dentistry and the food packaging industry. Although it has low estrogenic activity in somatolactotrophs and breast cancer cell lines, its presence in the environment and its long biological half-life have raised concerns about potential effects in humans. We analyzed the effect of BPA and compared its activity with E(2) in the PR1 cell line. PR1 cells show half-maximal proliferation upon treatment with 10 nM BPA, which is 10,000- to 100,000-fold less active than E(2). BPA-induced PR1 cell proliferation is decreased by the pure antiestrogen ICI, suggesting that BPA-induced PR1 cell proliferation is mediated by the estrogen receptor (ER). The decreased affinity of BPA for the ER is illustrated by the fact that 1 nM of ICI inhibited 100 nM BPA-induced cell proliferation, whereas 100 nM ICI was required to block 1 nM E(2)-induced cell proliferation. The PRL response to BPA required 1000 nM BPA to match the PRL secretion induced by 0.01 nM E(2). A competitive binding assay showed that the K(i) of BPA for the ER in PR1 cells is approximately 30-60 nM, which is 1000- to 2000-fold lower than that of E(2). Our study suggests the PR1 cell line can be used as an in vitro assay system for analyzing the effects of weak estrogens on ER-mediated responses and the activities of various estrogenic compounds present in small amounts in the environment.
Animals↗
Biocompatibility of biodegradable and nonbiodegradable polymer-coated stents implanted in porcine peripheral arteries.
PURPOSE: To investigate the neointimal response to poly(organo)phosphazene- and amphiphilic polyurethane-coated, oversized, stainless steel stents implanted in porcine peripheral arteries. METHODS: Nonarticulated, stainless steel, slotted-tube stents were coated with 1) a biodegradable poly-(organo)phosphazene with aminoacid ester side groups and 2) a biostable polyurethane prepared from an amphiphilic polyether, diphenyl methane-4,4'-diisocyanate and butane diol as chain extender. The stents were deployed in porcine peripheral arteries using an oversized balloon. RESULTS: The neonintimal response to amphiphilic polyurethane-coated stents was similar to the uncoated metallic stents. Poly(organo)phosphazene-coated stents, however, induced a severe histiolymphocytic and fibromuscular reaction resembling a foreign body reaction. CONCLUSIONS: Amphiphilic polyurethane is very promising as a biocompatible stent coating. Poly-(organo)phosphazene, however, appears unsuitable for this purpose.
Angioplasty, Balloon↗
Degradation of endocrine disrupting bisphenol A by 254 nm irradiation in different water matrices and effect on yeast cells.
The photodegradation of bisphenol A (BPA) in pure water, surface water and wastewater effluents was studied. The effect of different hydrogen peroxide concentrations on degradation was investigated. The rate of BPA photolysis in the presence of hydrogen peroxide was lower in wastewater effluent than in purified water. Phenol, 1,4-dihydroxylbenzene and 1,4-benzoquinone were identified by means of HPLC as intermediate products of the photodegradation of bisphenol A. In addition, the disappearance of the estrogenic activity of bisphenol A during irradiation was shown by the YES test. Based upon the YES test results, there was a strong decrease of estrogenic activity of parent compound after 120 min irradiation in the presence of hydrogen peroxide.
Benzhydryl Compounds↗
Effects of H1-antihistamine drug regimen on histamine release by nonlesional skin mast cells of patients with chronic urticaria.
Profiles of compound 48/80-induced histamine release (HR) from mast cells of uninvolved skin from patients with chronic urticaria (CU) and from a normal control (NC) group were compared, and the effects of anti-H1 medications were assessed versus placebo. Then, patients with CU (15) and NC subjects (10) were randomly assigned to take either hydroxyzine (100 mg/day), terfenadine (120 mg/day), or placebo for 28 days. The effects of such treatment on the clinical response and on the profile of compound 48/80-induced HR during a 4-hour period were analyzed. Treatment with hydroxyzine in patients with CU improved the clinical symptoms and modified the profile of HR; more histamine was recovered at 1 hour (p less than 0.05) and 2 hours (p less than 0.05), as compared with baseline. Terfenadine and placebo had no effect on the clinical response or on the profiles of HR. In the NC group, the amounts of histamine recovered at 1 hour after challenge with compound 48/80 were lower than amounts of the pretherapy values (p less than 0.01). It could be concluded that (1) the profile of HR in patients with CU is reproducible during a period of 28 days, (2) only hydroxyzine modifies both the clinical response and the profile of HR, and (3) anti-H1 compounds decrease the HR in the NC group.
Adult↗
The environmental estrogenic compound bisphenol A exerts estrogenic effects on mouse hippocampal (HT-22) cells: neuroprotection against glutamate and amyloid beta protein toxicity.
We have examined using immortalized clonal mouse hippocampal cell line (HT-22) whether the environmental estrogenic compound bisphenol A (BPA), like estrogen, has any neuroprotective effect against glutamate and amyloid beta protein-induced neurotoxicity. BPA protects HT-cells against both 5 mM glutamate and 2 microM amyloid beta protein-induced cell death in a dose dependent manner. Optimum protection was attained at 1 microM and 500 nM BPA against 5 mM glutamate and 2 microM amyloid beta protein-induced HT-22 cell death, respectively. Using confocal immunoflourescence microscopy technique, we observed that 20 h of treatment with 5 mM glutamate resulted in intense nuclear localization of the glucocorticoid receptors (GR) in HT-22 cells as compared to control untreated cells. Interestingly, 1 microM BPA treatment for 24 h, followed by 20-h treatment with 5 mM glutamate, resulted in dramatic reduction in GR nuclear localization. We conclude that: (i) BPA mimics estrogen and exerts neuroprotective effects against both neurotoxins used; (ii) BPA inhibits enhanced nuclear localization of GR induced by glutamate; and (iii) HT-22 cells provide a good in vitro model system for screening the potencies of various environmental compounds for their estrogenic activity.
Amyloid beta-Peptides↗
Ability of xeno- and phytoestrogens to modulate expression of estrogen-sensitive genes in rat uterus: estrogenicity profiles and uterotropic activity.
The function of the uterus is regulated by female sex steroids and it is, therefore, used as the classical target organ to detect estrogenic action. Uterine response to estrogens involves the activation of a large pattern of estrogen-sensitive genes. This fact offers the opportunity to analyze the estrogenic activity of xeno- and phytoestrogens, and the mechanisms of their molecular action by a correlation of the uterotropic activity and their ability to modulate the expression of estrogen-sensitive genes. We have analyzed the expression of androgen receptor (AR), progesterone receptor (PR), estrogen receptor (ER), clusterin (CLU), complement C3 (C3), and GAPDH mRNA in the rat uterus following oral administration of ethinylestradiol (EE), bisphenol A (BPA), o,p'-DDT (DDT), p-tert-octylphenol (OCT) and daidzein (DAI). A significant stimulation of the uterine wet weight could be observed after administration of all the substances. The activity of all analyzed compounds to stimulate uterine weight was low in comparison to EE. DDT has the highest activity to stimulate uterine weight whereas BPA and DAI turned out to be less potent. The analysis of gene expression revealed a very specific profile of molecular action in response to the different compounds which cannot be detected by judging the uterotropic response alone. A dose dependent analysis revealed that C3 mRNA is already modulated at doses where no uterotropic response was detectable. Although DAI and BPA were very weak stimulators of uterine growth, these substances were able to alter the expression of AR, ER and C3 very strongly. Based on these investigations the analyzed compounds can be subdivided into distinct classes: First, compounds which exhibit a similar gene expression fingerprint as EE (e.g. OCT); second, compounds exhibiting a significant uterotropic activity, but inducing a pattern of gene expression different from EE (e.g. DDT); and third, compounds like BPA and especially DAI which exhibit a very low uterotropic activity, but nevertheless modulate the expression of estrogen-sensitive genes. These findings strongly suggest that the fingerprint of uterine gene expression is a very sensitive tool to investigate estrogenicity of natural and synthetic compounds and offers the possibility to get information in regard to the molecular mechanisms involved in the action of the respective compounds.
Animals↗
Synthesis and quantification of DNA adducts of 4,4'-methylenedianiline.
4,4'-Methylenedianiline (MDA) is used as a hardener in the manufacture of plastics and polyurethanes. MDA has been classified as a carcinogen in animals and is a suspected human carcinogen. Assuming that MDA would yield similar DNA adducts to other arylamines, we synthesized the following C-8 guanine adducts: N'-acetyl-N-(deoxyguanosin-8-yl)-MDA, N-(deoxyguanosin-8-yl)-MDA, N-(deoxyguanosin-8-yl)-4MA, and their corresponding 3'-monophosphate derivatives. We developed methods to identify these adducts of MDA in liver DNA using 32P-postlabeling, HPLC, and GC-MS techniques. Liver DNA was obtained from rats treated with radiolabeled MDA (1.11 and 116.5 mumol/kg body weight). The total radioactivity bound to the DNA corresponded to 0.06 and 2.7 adducts per 10(7) nucleotides [covalent binding index (CBI = (mumol of adduct per mol of nucleotide)/(mmol of compound per kg body weight)) of 1.05 and 2.3]. This DNA-binding potency is in the range of weakly genotoxic compounds. The liver DNA was analyzed for the presence of the synthesized adducts by the following methods: (I) HPLC analysis of nucleotides and purines after enzymatic and acid hydrolysis, and (II) 32P-postlabeling after enzymatic hydrolysis. The major adducts found in vivo did not correspond to the synthesized standards. Further work was carried out to determine the structure of the unidentified adducts. It was possible to release MDA and MDA-d4 from DNA of rats dosed with MDA and/or MDA-d4 and from the synthesized adducts using strong base hydrolysis. Liver of two female Wistar rats given 500 mumol/kg MDA-2HCl was hydrolyzed in 0.1 M NaOH overnight at 110 degrees C. GC-MS analysis of the heptafluorobutyric anhydride derivatized dichloromethane extracts detected 428 +/- 40 fmol of MDA/mg of DNA. In the control animals no MDA was found. The experiment was repeated with livers from animals dosed 500 mumol/kg MDA-d4.2DCl. In these rats 488 +/- 19 fmol MDA-d4 was found to be bound at liver DNA. Taking into account a 68% yield of the method, the CBI found in these cases was 0.82 and 1.0, respectively.
Aniline Compounds↗
Biomonitoring of workers exposed to 4,4'-methylenedianiline or 4,4'-methylenediphenyl diisocyanate.
4,4'-Methylenedianiline (MDA) and 4,4'-methylenediphenyl diisocyanate (MDI) are important intermediates in the production of polyurethanes. In order to biomonitor people exposed to low levels of MDA or MDI we have developed sensitive methods to measure hemoglobin (Hb) adducts and urine metabolites. Adducts and metabolites from 33 workers exposed to MDA and 27 workers exposed to MDI were analyzed by gas chromatography-mass spectrometry after hydrolysis, extraction and derivatization with heptafluorobutyric anhydride. Hb adducts of MDA were detected in 31 out of the 33 MDA workers and both MDA and N-acetyl-MDA (AcMDA) were found in 20 of these individuals. The detection limit for MDA was 20 fmol and for AcMDA 100 fmol/sample, which correspond to an absolute detection limit of approximately 1 fmol MDA and 5 fmol AcMDA, respectively. In the urine of workers exposed to MDA both MDA and AcMDA were found in all samples, with the exception of five where only MDA was detected. Acid hydrolysis of the urine samples yielded an approximately 3-fold higher concentration of MDA than the sum of MDA and AcMDA found after base hydrolysis. MDA but not AcMDA found in urine and in Hb correlate well, except for three outliers. In one workers the Hb adduct level of MDA was very low compared to the urine levels. Two workers had very high levels of MDA as Hb adducts but very low levels as urine metabolites. The former case indicates that the workers were recently exposed to higher levels of MDA. The latter case suggests a relatively low recent exposure. The air levels of MDA, monitored using personal air monitors, were below the detection limit. It was possible, however, to determine exposure to MDA for all workers with the methods presented in this publication. Workers exposed exclusively to MDI were studied. Exposure levels, as monitored using personal air samplers, were below the detection limit of 3 micrograms/m3, with the exception of three individuals. In 10 of the MDI workers, hydrolyzable Hb adducts of MDA (57-219 fmol/g Hb) were found. Except for four subjects, the presence of MDA (0.007-0.14 nmol/l) and AcMDA (0.08-3 nmol/l) was detected in all urine samples after base treatment. Following acid hydrolysis of the urine, higher levels of MDA (0.7-10 nmol/l) were found than the sum of free MDA and AcMDA. According to the present data, it was possible to detect exposure to MDI in a greater number of individuals by analyzing urinary metabolites than by measuring Hb adducts or air monitoring.
Aniline Compounds↗
Solid-phase extraction of a carcinogen, 4,4'-methylenedianiline, in serum.
Polyurethane (PU) is a material used to make medical devices. During the gamma-ray or autoclave sterilization of these medical devices, PU degrades and a carcinogen, 4,4'-methylenedianiline (MDA), is produced. We studied a pretreatment method for MDA in blood serum by solid-phase extraction. Using Bond Elut C18, phenyl, and cyclohexyl columns, MDA in serum at a concentration of 0.1-10 ppm was 100% recovered with no apparent difference between the columns tested. Elution was carried out with methanol containing 1M MH4OH. The recovery rate of serum MDA with a Bond Elut C8 column was 90%, less than that from the above columns. The recovery of serum MDA from Bond Elut C1, C2, and silica was unsatisfactory. The recovery rate with Bond Elut SCX (strong cation exchange column) proved satisfactory, but the pretreatment of serum was troublesome as both deproteinization and centrifugal separation procedures were necessary in addition to the complicated conditioning procedure of the SCX column. There was no significant difference in recovery rate among C18, phenyl, and cyclohexyl columns, indicating that both pi-pi binding between benzene rings and van der Waals binding would be predominant. Because Bond Elut silica showed a lower recovery rate, the binding of NH2 in MDA with free silanol would not be predominant.
Aniline Compounds↗
2 cases of multiple azo dye sensitization.
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Aged↗
Assessment of occupational exposure to 4,4'-diaminodiphenylmethane (methylene dianiline) by gas chromatography-mass spectrometry analysis of urine.
A new specific and sensitive method has been used to monitor workers from five different factories where 4,4'-diaminodiphenylmethane (methylene dianiline) (DDM) was being used. The isolation and identification of an N-acetyl conjugate of DDM, a major metabolite of DDM found in human urine, is reported for the first time. The use of this biological monitoring method will allow the assessment of the absorption of DDM and help in monitoring improvements in work practices, particularly where exposure may occur through pathways other than inhalation.
Acetanilides↗
A biological monitoring assessment of exposure to methylene dianiline in manufacturers and users.
This paper describes a cross sectional study in which biological monitoring was used to assess exposure to methylene dianiline (MDA) in a selection of United Kingdom industries that manufacture or use MDA. Samples of urine were collected from 411 workers, representing 45 factories engaged in various activities. All urine samples were analysed for MDA and its acetyl metabolites and results are reported as total MDA. In this study, 91% of postshift urine samples and 88% of preshift samples had less than 50 nmol MDA/mmol creatinine. Some evidence was obtained which showed that when exposure to MDA was through inhalation (as solid material or contaminated dust), postshift urine samples had higher MDA concentrations than samples taken preshift the next day. When exposure was most likely to be through the dermal route, urine samples taken preshift next day tended to have higher MDA concentrations than urine samples collected immediately postshift on the day of exposure. Therefore a biological monitoring sampling strategy for MDA must take account of the route of entry into the body. If exposure is likely to be via inhalation, postshift samples should be collected and if exposure is likely via the skin, preshift samples next day are more appropriate. The results show that in most factories, regardless of the route of exposure, it is possible to keep urinary MDA concentrations below 50 nmol/mmol creatinine. In the absence of a health based or hygiene based standard, the use of a "yardstick" as a target to aim for, which has been derived from good working practice across the industry, may be a useful way of helping to control exposure.
Administration, Cutaneous↗
Comments on "Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography".
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Air Pollutants, Occupational↗