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Environmental Health Perspectives Oct 2020Endocrine-disrupting chemicals can interfere with hormonal homeostasis and have adverse effects for both humans and the environment. Their identification is increasingly...
BACKGROUND
Endocrine-disrupting chemicals can interfere with hormonal homeostasis and have adverse effects for both humans and the environment. Their identification is increasingly difficult due to lack of adequate toxicological tests. This difficulty is particularly problematic for cosmetic ingredients, because testing is now banned completely in the European Union.
OBJECTIVES
The aim was to identify candidate preservatives as endocrine disruptors by methods and to confirm endocrine receptors' activities through nuclear receptors .
METHODS
We screened preservatives listed in Annex V in the European Union Regulation on cosmetic products to predict their binding to nuclear receptors using the Endocrine Disruptome and VirtualToxLab™ version 5.8 tools. Five candidate preservatives were further evaluated for androgen receptor (AR), estrogen receptor (), glucocorticoid receptor (GR), and thyroid receptor (TR) agonist and antagonist activities in cell-based luciferase reporter assays in AR-EcoScreen, , MDA-kb2, and GH3.TRE-Luc cell lines. Additionally, assays to test for false positives were used (nonspecific luciferase gene induction and luciferase inhibition).
RESULTS
Triclocarban had agonist activity on AR and at and antagonist activity on GR at and TR at . Triclosan showed antagonist effects on AR, , GR at and TR at , and bromochlorophene at (AR and TR) and at ( and GR). AR antagonist activity of chlorophene was observed [inhibitory concentration at 50% (IC) ], as for its substantial agonist at and TR antagonist activity at . Climbazole showed AR antagonist (), agonist at , and TR antagonist activity at .
DISCUSSION
These data support the concerns of regulatory authorities about the endocrine-disrupting potential of preservatives. These data also define the need to further determine their effects on the endocrine system and the need to reassess the risks they pose to human health and the environment. https://doi.org/10.1289/EHP6596.
Topics: Androgen Receptor Antagonists; Carbanilides; Cell Line; Computer Simulation; Dichlorophen; Endocrine Disruptors; Genes, Reporter; Humans; Imidazoles; Receptors, Androgen; Receptors, Estrogen; Receptors, Glucocorticoid; Triclosan
PubMed: 33064576
DOI: 10.1289/EHP6596 -
Journal of Biomedical Materials... Apr 2006In this study, a comparison of the sealing properties of three different resin-based sealers, AH26, Diaket, and EndoREZ with those of the root canal sealer zinc... (Comparative Study)
Comparative Study
In this study, a comparison of the sealing properties of three different resin-based sealers, AH26, Diaket, and EndoREZ with those of the root canal sealer zinc oxide-eugenol-based U/P Root Canal Sealer was performed. Eighty extracted single-rooted human mandibular first premolar teeth were used. The coronal part of each tooth was removed at the apical 17-mm of roots. The root canals were prepared to a size 7 with ProFile 0.06 taper Series 29 rotary instruments in a crown-down manner before lateral condensation of gutta-percha with the tested sealers (n = 20). A fluid filtration method was used for quantitative evaluation of apical leakage. Statistical analysis revealed that there were no significant differences between the resin-based sealers groups (AH26, Diaket, and EndoREZ) (p > 0.05). U/P Root Canal Sealer, zinc oxide-eugenol-based sealer, leaked significantly more than other tested groups (p < 0.05). Under the limitations of this study, resin-based root canal sealers were found more effective in sealing root canals than the zinc oxide-eugenol-based sealer.
Topics: Biocompatible Materials; Bismuth; Composite Resins; Dental Leakage; Dental Pulp Cavity; Drug Combinations; Epoxy Resins; Humans; Materials Testing; Polyvinyls; Resin Cements; Root Canal Filling Materials; Silver; Titanium; Tooth Apex; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 16206202
DOI: 10.1002/jbm.b.30408 -
International Endodontic Journal Jul 1990An in vitro method for the cytotoxicity testing of endodontic materials is described which aims to simulate the clinical situation. Materials can be tested in the... (Comparative Study)
Comparative Study
An in vitro method for the cytotoxicity testing of endodontic materials is described which aims to simulate the clinical situation. Materials can be tested in the presence or absence of a compacted layer of dentine chips mimicking the periapical dentine plug. A total of twelve materials were tested. In the absence of dentine, Kloroperka, Biocalex, Diaket and Endomethasone were slightly cytotoxic; AH26 with and without silver, Sealapex, Tubliseal and Kerr's pulp canal sealer were moderately cytotoxic, while Forfenan, Spad and Kri paste were strongly cytotoxic. In the presence of dentine the cytotoxicity of these materials was considerably reduced, with the exception of Endomethasone, Forfenan, Spad and Kri paste. The method provides a satisfactory alternative to implantation testing and is an inexpensive and reproducible test system in which dentine can be incorporated.
Topics: Administration, Topical; Anti-Inflammatory Agents; Balsams; Biocompatible Materials; Bismuth; Bisphenol A-Glycidyl Methacrylate; Calcium Hydroxide; Cells, Cultured; Dental Cements; Dentin; Dexamethasone; Drug Combinations; Epoxy Resins; Formaldehyde; Gutta-Percha; Hydrocortisone; Methacrylates; Methenamine; Polymers; Polyvinyls; Resorcinols; Root Canal Filling Materials; Salicylates; Silver; Thymol; Titanium; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 2151515
DOI: 10.1111/j.1365-2591.1990.tb00101.x -
BMC Oral Health May 2011The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket. (Comparative Study)
Comparative Study
BACKGROUND
The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.
METHODS
Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.
RESULTS
There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.
CONCLUSIONS
It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.
Topics: Aluminum Compounds; Animals; Bismuth; Calcium Compounds; Connective Tissue; Dentin; Drug Combinations; Humans; Inflammation; Male; Oxides; Polyvinyls; Rats; Rats, Wistar; Root Canal Filling Materials; Silicates; Statistics, Nonparametric; Time Factors; Zinc Oxide
PubMed: 21569463
DOI: 10.1186/1472-6831-11-17 -
Fundamental and Applied Toxicology :... Nov 1986o-Benzyl-p-chlorophenol (BCP) is a major household and industrial germicide. Its prechronic toxicity was evaluated in male and female F344 rats and B6C3F1 mice....
o-Benzyl-p-chlorophenol (BCP) is a major household and industrial germicide. Its prechronic toxicity was evaluated in male and female F344 rats and B6C3F1 mice. Treatment was by gavage in corn oil. BCP was slightly toxic after acute oral exposure, with high mortality at 4000 and 2000 mg/kg in rats and mice. Exposure to 12 oral doses of BCP at 1000, 500, 250, 125, 62.5, or 0 mg/kg body wt resulted in dose-related cecal dilatation and nephrosis in both rats and mice. Doses for the subchronic studies were based on the results of the 2-week studies. Ten animals were treated per dose per sex. Rats received 480, 240, 120, 60, 30, or 0 mg BCP/kg. Mice were treated with 1000, 800, 650, 500, or 0 mg BCP/kg. Animals were dosed 5 days per week for 13 weeks. Clinical signs related to dosing included urogenital staining in rats and rough/oily haircoats in mice. No effects on growth rate were seen in rats, but growth was retarded at the higher doses used in mice. Kidney weights increased in rats, and liver weights increased in mice. A decrease in thymus weight accompanied by a depletion in thymic lymphocytes (rats) or thymic necrosis (mice) occurred only in a high-dose animals. In both species, the kidney was the major target organ. In rats, there was an increase in incidence and severity of nephropathy and renal tubule regeneration. The lesions in mice primarily involved the renal cortex and included necrosis, casts, chronic inflammation, and regeneration of the renal tubules. No effects of BCP exposure in rats were seen in a broad spectrum of hematology or urinalysis parameters. Minor decreases in blood urea nitrogen, creatinine, and alanine amino transferase were detected in male and female rats. There were no biologically significant neurobehavioral effects in rats or immunotoxic effects in mice due to exposure to BCP. Thus, the kidney is the major target organ for BCP.
Topics: Animals; Body Weight; Dichlorophen; Disinfectants; Drug Administration Schedule; Female; Immunity; Kidney; Male; Mice; Mice, Inbred Strains; Rats; Rats, Inbred F344
PubMed: 3803756
DOI: 10.1016/0272-0590(86)90111-9 -
Journal of Endodontics Feb 2008The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly... (Comparative Study)
Comparative Study Randomized Controlled Trial
The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 +/-14.8 days) followed by AH Plus and MTA (66.1 +/- 18.7), Diaket and amalgam (60.0 +/- 23.1), AH Plus and amalgam (56.9 +/- 22.1), and Ketac Endo and MTA (42.1 +/- 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 +/- 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05).
Topics: Aluminum Compounds; Apicoectomy; Biomarkers; Bismuth; Calcium Compounds; Dental Amalgam; Dental Leakage; Dental Pulp Cavity; Drug Combinations; Enterococcus faecalis; Epoxy Resins; Glass Ionomer Cements; Gutta-Percha; Humans; Lactobacillus; Materials Testing; Oxides; Polyvinyls; Retrograde Obturation; Root Canal Filling Materials; Root Canal Obturation; Silicates; Staphylococcus aureus; Streptococcus mitis; Streptococcus mutans; Time Factors; Zinc Oxide
PubMed: 18215682
DOI: 10.1016/j.joen.2007.09.019 -
The association between urinary concentrations of dichlorophenol pesticides and obesity in children.Reviews on Environmental Health 2011Increasing prevalence of childhood obesity has been seen in the United States and other parts of the world. Environmental chemical exposures might play a role in the...
BACKGROUND
Increasing prevalence of childhood obesity has been seen in the United States and other parts of the world. Environmental chemical exposures might play a role in the worldwide obesity epidemic.
OBJECTIVE
This study was conducted to assess the association of exposure to environmental pesticides with childhood obesity.
METHODS
A total of 6770 subjects aged 6-19 years were selected from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey (NHANES). Exposure to environmental pesticides was determined based on the concentrations of pesticide residues in urine. Multivariate logistic regression was performed using SAS 9.1.3 to assess the association between pesticide levels in urine and childhood obesity with the adjustment of potential confounders, including age, gender, race, income, and total fat intake.
RESULTS
A dose-dependent increase in prevalence of obesity was observed in the groups with inter-quartile urinary concentrations of 2,5-dichlorophenol (2,5-DCP). Logistic regression revealed a significant association between adjusted third (Q3) (AOR: 1.47; 95% CI: 1.09, 1.97) and fourth (Q4) (AOR: 1.44; 95% CI: 1.06, 1.95) inter-quartile urinary 2,5-DCP levels and childhood obesity. However, urinary concentrations of 2,4-dichlorophenol were not shown to be significantly associated with childhood obesity.
CONCLUSION
This study suggests a possible relationship between exposure to 2,5-DCP and obesity in children.
Topics: Adolescent; Anthelmintics; Child; Chlorophenols; Dichlorophen; Environmental Exposure; Female; Humans; Logistic Models; Male; Nutrition Surveys; Obesity; Pesticide Residues; Pesticides; United States; Young Adult
PubMed: 22206198
DOI: 10.1515/reveh.2011.029 -
Journal of Neurophysiology Nov 2008Previous studies have demonstrated that locally administered cannabinoids attenuate allodynia and hyperalgesia through activation of peripheral cannabinoid receptors...
Previous studies have demonstrated that locally administered cannabinoids attenuate allodynia and hyperalgesia through activation of peripheral cannabinoid receptors (CB(1) and CB(2)). However, it is currently unknown if cannabinoids alter the response properties of nociceptors. In the present study, correlative behavioral and in vivo electrophysiological studies were conducted to determine if peripheral administration of the cannabinoid receptor agonists arachidonyl-2'-chloroethylamide (ACEA) or (R)-(+)-methanandamide (methAEA) could attenuate mechanical allodynia and hyperalgesia, and decrease mechanically evoked responses of Adelta nociceptors. Twenty-four hours after intraplantar injection of complete Freund's adjuvant (CFA), rats exhibited allodynia (decrease in paw withdrawal threshold) and hyperalgesia (increase in paw withdrawal frequency), which were attenuated by both ACEA and methAEA. The antinociceptive effects of these cannabinoids were blocked by co-administration with the CB(1) receptor antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophen yl)-4-methyl-1H-pyrazole-3-carboxamide (AM251) but not with the CB(2) receptor antagonist 6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-y l](4-methoxyphenyl)methanone (AM630). ACEA and methAEA did not produce antinociception under control, non-inflamed conditions 24 h after intraplantar injection of saline. In parallel studies, recordings were made from cutaneous Adelta nociceptors from inflamed or control, non-inflamed skin. Both ACEA and methAEA decreased responses evoked by mechanical stimulation of Adelta nociceptors from inflamed skin but not from non-inflamed skin, and this decrease was blocked by administration of the CB(1) receptor antagonist AM251. These results suggest that attenuation of mechanically evoked responses of Adelta nociceptors contributes to the behavioral antinociception produced by activation of peripheral CB(1) receptors during inflammation.
Topics: Action Potentials; Analysis of Variance; Animals; Arachidonic Acids; Cannabinoids; Dose-Response Relationship, Drug; Drug Interactions; Freund's Adjuvant; Inflammation; Male; Nerve Fibers, Myelinated; Neural Conduction; Nociceptors; Pain Measurement; Pain Threshold; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Skin
PubMed: 18784270
DOI: 10.1152/jn.90809.2008 -
Journal of Endodontics Apr 2006The aim of this study was to determine the leakage of SuperEBA and intermediate restorative material (IRM) in root canal samples, with or without orthograde filling, by... (Comparative Study)
Comparative Study
The aim of this study was to determine the leakage of SuperEBA and intermediate restorative material (IRM) in root canal samples, with or without orthograde filling, by evaluating bovine serum albumin (BSA) microleakage using spectrophotometry. Thirty-five single-rooted teeth were divided into five groups, instrumented, and had apices resected. Root-end cavities in groups I and II were filled with SuperEBA and IRM. The samples from the groups III, IV, and V were filled with gutta-percha and sealer. In groups IV and V, root-end cavities were filled with SuperEBA and IRM. After 60 days, the greatest microleakage of BSA was observed in group II (4.1 +/- 0.0011 ng), followed by group III (3.4 +/- 0.0064 ng), and then group I (2.6 +/- 0.0019 ng). Samples from groups IV and V leaked the least (0.7 +/- 0.0014 ng). Significantly less leakage (p < 0.05) occurred in samples filled with orthograde and root-end fillings than did in samples filled only with an orthograde approach and the samples with IRM root-end fillings.
Topics: Animals; Bismuth; Cattle; Dental Leakage; Dentin-Bonding Agents; Drug Combinations; Gutta-Percha; Humans; Methylmethacrylates; Polyvinyls; Root Canal Filling Materials; Root Canal Obturation; Serum Albumin, Bovine; Zinc Oxide; Zinc Oxide-Eugenol Cement
PubMed: 16554215
DOI: 10.1016/j.joen.2005.09.008 -
British Journal of Pharmacology and... Sep 1960A simple and convenient in vitro technique is described for the screening of compounds for action against Hymenolepis nana and probably many other intestinal worms. The...
A simple and convenient in vitro technique is described for the screening of compounds for action against Hymenolepis nana and probably many other intestinal worms. The results obtained from this test are in broad agreement with the findings of clinical experience and of a small series of in vivo tests. Among the substances tested, the most active ones were oil of chenopodium, dichlorophen, extract of cashew nut (Anacardium occidentale), antimony potassium tartrate, and BIQ 20 [eicosamethylenebis(isoquinolinium iodide)].
Topics: Anacardium; Animals; Anthelmintics; Cestoda; Cestode Infections; Hymenolepis nana; In Vitro Techniques
PubMed: 13750047
DOI: 10.1111/j.1476-5381.1960.tb01269.x