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Takiguchi T, Vu HT, Nishino Y. Effects of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans, and Dioxin-like PCBs on Teeth and Bones in Animals and Humans. TOXICS 2022; 11:7. [PMID: 36668733 PMCID: PMC9866321 DOI: 10.3390/toxics11010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/09/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Bone metabolism is regulated by endocrine systems, so people exposed to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) may suffer adverse effects on bones and teeth. We reviewed previous publications in which effects of PCDD/Fs and dioxin-like polychlorinated biphenyls on the teeth and bones of animals and humans were found. The aim was to identify future research directions, particularly for epidemiological studies of populations exposed to PCDD/Fs in the environment. Exposure of fetuses to PCDD/Fs may affect odontogenesis, particularly enamel formation, but the effects of PCDD/Fs on bone genesis are limited to palatine bone. Exposure to PCDD/Fs in milk may affect both teeth and bones, but the effects on bones may be reversible. Exposure to high PCDD/F concentrations even during adulthood may adversely affect teeth. Exposure to PCDD/Fs may induce osteogenesis and improve bone properties because the disrupting effects of PCDD/Fs cause bone remodeling and vitamin D activation. More studies involving humans are required to investigate previously found associations between the PCDD/F concentrations humans are exposed to and biological markers for teeth and bones, including metabolites of vitamin D.
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Dobrzyński M, Nikodem A, Klećkowska-Nawrot J, Goździewska-Harłajczuk K, Janeczek M, Styczyńska M, Kuropka P. Assessment of Selected Morphological, Physical and Chemical Parameters of the Teeth of the Offspring of Female Rats Exposed to 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), Taking into Account the Protective Role of Selected Antioxidants—Preliminary Study. Animals (Basel) 2022; 12:ani12040484. [PMID: 35203192 PMCID: PMC8868449 DOI: 10.3390/ani12040484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 02/04/2023] Open
Abstract
The studies conducted so far indicate a negative effect of dioxins on the structure of the alveolar bone and teeth, especially in the developmental period in rats. The research aimed to analyze the indirect effect of dioxins contained in the body of female rats on the structure of the dental organ in their offspring in the neonatal period and to determine the possibility of reducing potential dioxin disorders of the structure of hard tissues in the offspring of intoxicated mothers by simultaneous administration of vitamin E or acetylsalicylic acid (ASA). Another goal of the research was to determine the level of magnesium, calcium and phosphorus contained in bone tissue as indicators of the mineralization process of hard tissues in rats, in the case of using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and acetylsalicylic acid or α-tocopherol. The experiment was carried out on eight female rats of the Buffalo strain divided into four groups. From the offspring of eight females, the mandibles were removed from the mandibular joints, and then, after the removal of soft tissues, they were prepared for individual tests. Selected morphological, chemical and physical parameters of the teeth of the offspring of female rats from the experimental groups were analyzed. The analysis showed the effect of vitamin E and ASA on the content of Mg, Ca and P. In combination with TCDD, vitamin E and ASA, they positively inhibit the inflammatory process, preventing the leaching of Ca and Mg from the bones. ASA counteracted this phenomenon much more effectively than vitamin E. Detailed analysis of the tooth morphology showed that the molars’ crowns exhibit shape disturbances under the influence of TCDD. Individual nodules in teeth T1, T2, T3 did not fuse, and the roots showed signs of hypertrophy. The study confirmed the negative effect of TCDD on tooth development. Teeth arising early in development are the most sensitive to the disorders, while the later ones are less exposed to the toxic effects of TCDD transmitted by the mother.
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Affiliation(s)
- Maciej Dobrzyński
- Department of Pediatric Dentistry and Preclinical Dentistry, Wroclaw Medical University, Krakowska 26, 50-425 Wroclaw, Poland
- Correspondence: (M.D.); (K.G.-H.)
| | - Anna Nikodem
- Department of Mechanics, Materials and Biomedical Engineering, Faculty of Mechanical Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland;
| | - Joanna Klećkowska-Nawrot
- Department of Biostructure and Animal Physiology, Division of Animal Anatomy, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Kożuchowska 1, 51-631 Wroclaw, Poland; (J.K.-N.); (M.J.)
| | - Karolina Goździewska-Harłajczuk
- Department of Biostructure and Animal Physiology, Division of Animal Anatomy, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Kożuchowska 1, 51-631 Wroclaw, Poland; (J.K.-N.); (M.J.)
- Correspondence: (M.D.); (K.G.-H.)
| | - Maciej Janeczek
- Department of Biostructure and Animal Physiology, Division of Animal Anatomy, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Kożuchowska 1, 51-631 Wroclaw, Poland; (J.K.-N.); (M.J.)
| | - Marzena Styczyńska
- Faculty of Biotechnology and Food Sciences, Wroclaw University of Environmental and Life Sciences, Chełmońskiego 37/41, 51-630 Wroclaw, Poland;
| | - Piotr Kuropka
- Department of Biostructure and Animal Physiology, Division of Histology and Embryology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Norwida 25, 50-635 Wroclaw, Poland;
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Aminu N, Yam MF, Chan SY, Bello I, Umar NM, Nuhu T, Toh SM. The evaluation of healing effect of triclosan and flurbiprofen-loaded nanogels in experimental periodontitis in rats by morphometric analysis. Saudi Dent J 2021; 33:554-559. [PMID: 34803300 PMCID: PMC8589614 DOI: 10.1016/j.sdentj.2020.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 08/18/2020] [Accepted: 08/23/2020] [Indexed: 10/24/2022] Open
Abstract
Purpose To evaluate therapeutic effectiveness of antibacterial triclosan (TCS) and anti-inflammatory flurbiprofen (FLB)-loaded nanogels system in ligature-induced experimental periodontitis in rats. Methodology A total of 72 Sprague-Dawley rats were used in this study. Four groups (n = 18 each) were randomly created: Group 1 - neither subjected to experimental periodontitis nor to any treatment; Group 2 - subjected to experimental periodontitis but not treated; Group 3 - subjected to experimental periodontitis and then treated with the developed nanogels; Group 4 - subjected to experimental periodontitis and then placed on a mixture of pure TCS and FLB treatment. The experimental periodontitis was induced on the lower incisors by applying a ligature which was kept for 14 days. Treatment was done for 7 days, and sampling was done at 7, 14, and 28 day of the post-induction experimental period. Morphometric analysis was conducted to assess the clinical outcomes and healing effect. Results The morphometric findings showed that the group treated with the developed TCS and FLB-loaded nanogels recovered better and faster than a mixture of pure TCS and FLB. At 28 day of the experimental period, there was no significant difference (p > 0.05) between the baseline control group and the nanogels treated group. Conclusions The developed TCS and FLB-loaded nanogels was found to be effective in the treatment of experimental periodontitis in rats. The used experimental periodontitis model was found to be simple and easily reproducible.
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Affiliation(s)
- Nafiu Aminu
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria
| | - Mun-Fei Yam
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Siok-Yee Chan
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Idris Bello
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Nura Muhammad Umar
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria.,School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
| | - Tanko Nuhu
- Department of Pharmaceutics and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, Usmanu Danfodiyo University, Sokoto, P.M.B. 2346, Sokoto, Nigeria
| | - Seok-Ming Toh
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM Penang, Malaysia
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Całkosińska A, Dominiak M, Sobolewska S, Leśków A, Tarnowska M, Całkosiński A, Dobrzyński M. The Protective Effect of Xanthohumol on the Content of Selected Elements in the Bone Tissue for Exposed Japanese Quails to TCDD. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5883. [PMID: 32823692 PMCID: PMC7460139 DOI: 10.3390/ijerph17165883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 08/04/2020] [Accepted: 08/05/2020] [Indexed: 11/25/2022]
Abstract
Dioxins (including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are highly toxic and persistent chemicals widely distributed in the environment in trace amounts, and are side products of industrial and chemical processes. Exposure to dioxins leads to multiorgan morphological and functional abnormalities, including within the bone tissue, disrupting its microarchitecture and mechanical properties. Xanthohumol (XN) is a chemical compound classified as a prenylated flavonoid, distinguished by multidirectional biological action. The aim of the study is to assess whether xanthohumol, as a substance with strong antioxidant and anti-inflammatory properties, has the ability to eliminate the negative effects of TCDD on bone tissue. The experiment was conducted on adult Japanese quails. Two different doses of TCDD and xanthohumol were administered to birds. After euthanasia of animals, the research material in the form of cranial vault and hind limb bone was collected, and their mineral compositions of calcium, phosphorus, magnesium, zinc, and iron concentrations were determined using atomic emission spectrometry in an acetylene-air flame method. Our results indicate that the administration of TCDD at a low dose causes more dynamic changes in the concentration of elements in bone, in comparison to a higher dose of dioxin. Results show also that higher doses of the XN cause the linear increase in the concentration of phosphorus and iron in the bone of the hind limb, and calcium in the bones of the cranial vault. In conclusion, our experiment shows that the use of TCDD and XN in Japanese quails together in various doses influences the content of phosphorus, magnesium, zinc, and iron in the research material.
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Affiliation(s)
- Aleksandra Całkosińska
- Department of Oral Surgery, Wroclaw Medical University, Krakowska 26 Street, 50-425 Wroclaw, Poland;
| | - Marzena Dominiak
- Department of Oral Surgery, Wroclaw Medical University, Krakowska 26 Street, 50-425 Wroclaw, Poland;
| | - Sylwia Sobolewska
- Department of Animal Nutrition and Feed Management, Wroclaw University of Environmental and Life Sciences, Chelmonskiego 38c Street, 51-630 Wroclaw, Poland;
| | - Anna Leśków
- Department of Nervous System Diseases, Faculty of Health Science, Wroclaw Medical University, Bartla Street 5, 51-618 Wroclaw, Poland; (A.L.); (M.T.)
| | - Małgorzata Tarnowska
- Department of Nervous System Diseases, Faculty of Health Science, Wroclaw Medical University, Bartla Street 5, 51-618 Wroclaw, Poland; (A.L.); (M.T.)
| | - Aleksander Całkosiński
- Students’ Scientific Association of Biomaterials and Experimental Dentistry, Wroclaw Medical University, Bujwida 44 Street, 50-368 Wroclaw, Poland;
| | - Maciej Dobrzyński
- Department of Conservative Dentistry and Pedodontics, Wroclaw Medical University, Krakowska 26 Street, 50-425 Wroclaw, Poland;
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Dobrzynski M, Kuropka P, Tarnowska M, Dudek K, Styczynska M, Leskow A, Targonska S, Wiglusz RJ. Indirect study of the effect of α-tocopherol and acetylsalicylic acid on the mineral composition of bone tissue in the offspring of female rats treated with 2,3,7,8-tetrachlorodibenzo- p-dioxin: long-term observations. RSC Adv 2019; 9:8016-8024. [PMID: 35547832 PMCID: PMC9087305 DOI: 10.1039/c8ra10485a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/15/2019] [Indexed: 11/21/2022] Open
Abstract
This paper discusses problems related to the influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the mineral composition of the calvaria in the offspring of female rats.
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Affiliation(s)
- Maciej Dobrzynski
- Department of Conservative Dentistry and Pedodontics, The Faculty of Dentistry, Wroclaw Medical University, Wroclaw, Poland
| | - Piotr Kuropka
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Malgorzata Tarnowska
- Department of Nervous System Diseases, Faculty of Health Science, Wroclaw Medical University, Wroclaw, Poland
| | - Krzysztof Dudek
- Department of Logistics and Transport Systems, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Marzena Styczynska
- Department of Human Nutrition, Faculty of Food Science, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Anna Leskow
- Department of Nervous System Diseases, Faculty of Health Science, Wroclaw Medical University, Wroclaw, Poland
| | - Sara Targonska
- Institute of Low Temperature and Structure Research, Polish Academy of Science, Wroclaw, Poland
| | - Rafal J. Wiglusz
- Institute of Low Temperature and Structure Research, Polish Academy of Science, Wroclaw, Poland
- Centre for Advanced Materials and Smart Structures, Polish Academy of Sciences, Wroclaw, Poland
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Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot AC, Schwerdtle T, Vleminckx C, Vollmer G, Wallace H, Fürst P, Håkansson H, Halldorsson T, Lundebye AK, Pohjanvirta R, Rylander L, Smith A, van Loveren H, Waalkens-Berendsen I, Zeilmaker M, Binaglia M, Gómez Ruiz JÁ, Horváth Z, Christoph E, Ciccolallo L, Ramos Bordajandi L, Steinkellner H, Hoogenboom LR. Risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food. EFSA J 2018; 16:e05333. [PMID: 32625737 PMCID: PMC7009407 DOI: 10.2903/j.efsa.2018.5333] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of dioxins (PCDD/Fs) and DL-PCBs in feed and food. The data from experimental animal and epidemiological studies were reviewed and it was decided to base the human risk assessment on effects observed in humans and to use animal data as supportive evidence. The critical effect was on semen quality, following pre- and postnatal exposure. The critical study showed a NOAEL of 7.0 pg WHO2005-TEQ/g fat in blood sampled at age 9 years based on PCDD/F-TEQs. No association was observed when including DL-PCB-TEQs. Using toxicokinetic modelling and taking into account the exposure from breastfeeding and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The CONTAM Panel established a TWI of 2 pg TEQ/kg bw/week. With occurrence and consumption data from European countries, the mean and P95 intake of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between, respectively, 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. Exposure to PCDD/F-TEQ only was on average 2.4- and 2.7-fold lower for mean and P95 exposure than for total TEQ. PCDD/Fs and DL-PCBs are transferred to milk and eggs, and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species. The CONTAM Panel was not able to identify reference values in most farm and companion animals with the exception of NOAELs for mink, chicken and some fish species. The estimated exposure from feed for these species does not imply a risk.
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Dobrzynski M, Pezowicz C, Tomanik M, Kuropka P, Dudek K, Fita K, Styczynska M, Wiglusz RJ. Modulating effect of selected pharmaceuticals on bone in female rats exposed to 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD). RSC Adv 2018; 8:27537-27545. [PMID: 35540011 PMCID: PMC9083442 DOI: 10.1039/c8ra03619e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 07/20/2018] [Indexed: 01/27/2023] Open
Abstract
This paper discusses the problems connected with the influence of TCDD on the mechanical properties and structure of the bone tissue in female rats treated with the dioxin. Moreover an analysis of the protective role of tocopherol, acetylsalicylic acid, dexamethazone and levamisol was performed. Rat tibiae were assessed by mechanical testing, and histological and trace element analysis. It was proved that TCDD has negative effect on bone mechanical properties, histological microstructure and trace element content. The results indicate that usage of both steroid and non-steroid anti-inflammatory medicaments, along with tocopherol and levamisol, modulating their activity, can reduce the negative effect of dioxin activity on the bone tissue of female rats intoxicated with TCDD.
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Affiliation(s)
- Maciej Dobrzynski
- Department of Conservative Dentistry and Pedodontics, The Faculty of Dentistry, Wroclaw Medical University Poland +48(71)784-03-62 +48(71)784-03-61
| | - Celina Pezowicz
- Department of Biomedical Engineering, Mechatronics and Theory of Mechanisms, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology Poland
| | - Magdalena Tomanik
- Department of Biomedical Engineering, Mechatronics and Theory of Mechanisms, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology Poland
| | - Piotr Kuropka
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences Poland
| | - Krzysztof Dudek
- Department of Logistics and Transport Systems, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology Poland
| | - Katarzyna Fita
- Department of Conservative Dentistry and Pedodontics, The Faculty of Dentistry, Wroclaw Medical University Poland +48(71)784-03-62 +48(71)784-03-61
| | - Marzena Styczynska
- Department of Human Nutrition, Faculty of Food Science, Wroclaw University of Environmental and Life Sciences Poland
| | - Rafal J Wiglusz
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences Okolna 2 50-422 Wroclaw Poland +48(71)344-10-29 +48(71)395-41-59
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Ngoc VTN, Huong LT, Van Nhon B, Tan NTM, Van Thuc P, Hien VTT, Dung TM, Van Toan N, Anh LQ, Son LH, Chu-Dinh T, Chu DT. The higher prevalence of developmental defects of enamel in the dioxin-affected region than non-dioxin-affected region: result from a cross-sectional study in Vietnam. Odontology 2018; 107:17-22. [DOI: 10.1007/s10266-018-0358-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/02/2018] [Indexed: 11/29/2022]
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Gao Y, Sahlberg C, Kiukkonen A, Alaluusua S, Pohjanvirta R, Tuomisto J, Lukinmaa PL. Lactational Exposure of Han/Wistar Rats to 2,3,7,8-Tetrachlorodibenzo-p-dioxin Interferes with Enamel Maturation and Retards Dentin Mineralization. J Dent Res 2016; 83:139-44. [PMID: 14742652 DOI: 10.1177/154405910408300211] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Exposure to environmental dioxins via mother’s milk may be one causative factor of mineralization defects in children’s teeth. A prerequisite for the completion of enamel mineralization is the removal of enamel matrix. To test the hypothesis that dioxins interfere with enamel maturation, we administered lactating Han/Wistar rats a single dose of 2,3,7,8-tetrachlorodibenzo -p-dioxin (TCDD; 50 or 1000 μg/kg) on the day after delivery and analyzed tissue sections of the pup heads at post-natal days (Pn) 9 and 22. By Pn22, the first and second molars of the exposed pups, but not controls, showed retention of enamel matrix. Predentin was thicker than normal. Immunostaining for the aryl hydrocarbon/dioxin receptor (AhR) and cytochrome P4501A1 (CYP1A1) in ameloblasts and odontoblasts was reduced, suggesting that TCDD interferes with tooth mineralization via AhR. Extinction of AhR may lead to abolition of CYP1A1 expression as a sign of impaired dental cell function.
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Affiliation(s)
- Y Gao
- Department of Pedodontics and Orthodontics, Institute of Dentistry, University of Helsinki, Finland
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Long PH, Herbert RA, Nyska A. Hexachlorobenzene-Induced Incisor Degeneration in Sprague—Dawley Rats. Toxicol Pathol 2016; 32:35-40. [PMID: 14713546 DOI: 10.1080/01926230490260871] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Hexachlorobenzene (HCB) was administered to female Sprague—Dawley rats in a 13-week toxicity study conducted for the National Toxicology Program (NTP). Groups of 10 rats were treated by gavage with 0.0, 0.03, 0.1, 0.3, 1.0, 3.0, 10, or 25 mg/kg HCB in corn oil 5 days/week for 13 weeks. Dose-dependent, region-specific, maxillary incisor degeneration was observed in animals given HCB at doses of 1.0 mg/kg/day and higher. Treatment with 1.0 mg/kg/day resulted in focal mesenchymal cell vacuolation and focal osteodentin formation within the pulp. Lesions were restricted to a short linear region subjacent to the odontoblast layer along the lateral aspect of the incisor at the level of the dentin-enamel interface. When observed in both incisors, lesions were bilaterally symmetric. Treatment with 3.0 mg/kg/day resulted in lateral and medial pulp lesions and focal odontoblast degeneration with dentin niche formation along the lateral incisor margin in some animals. Treatment with 10 mg/kg/day resulted in a higher incidence of lateral dentin niches and a low incidence of medial dentin niches. In animals treated with 25 mg/kg/day, a high incidence of bilaterally symmetric, lateral and medial, dentin niches were observed. The morphology and distribution of HCB-induced incisor lesions in rats are consistent with injury to a selective population of preodontoblasts.
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Affiliation(s)
- Philip H Long
- Pathology Associates, A Division of Charles River Laboratories, Inc, West Chester, Ohio 45069, USA.
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Sholts SB, Esteban J, Herlin M, Viluksela M, Håkansson H. Craniofacial form is altered by chronic adult exposure to 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) in Han/Wistar and Long-Evans rats with different aryl hydrocarbon receptor (AhR) structures. Toxicol Rep 2014; 2:472-481. [PMID: 28962383 PMCID: PMC5598109 DOI: 10.1016/j.toxrep.2014.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 12/12/2014] [Indexed: 12/30/2022] Open
Abstract
Mammalian bone has shown a variety of responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure in experimental and wildlife studies. Although many responses have been well characterized in the postcranial skeleton, dioxin-induced effects on the cranium are largely unknown. In this study, we investigated the effects of chronic adult exposure to TCDD on cranial size and shape in dioxin-resistant Han/Wistar (H/W) and dioxin-sensitive Long–Evans (L–E) rat strains. Three-dimensional landmark configurations for the face, vault, and base of the cranium were recorded and analyzed using geometric morphometrics (GM) and dose–response modeling. The strongest effects were shown by L–E and H/W rats with daily exposures of 100 and 1000 ng TCDD/kg bw/day, respectively, resulting in significant reductions in centroid size (CS) in all three cranial modules for both strains except for the vault in H/W rats. Consistent with previous evidence of intraspecific variation in TCDD resistance, the benchmark doses (CEDs) for cranial size reduction in L–E rats were roughly 10-fold lower than those for H/W rats. For both strains, the face showed the greatest size reduction from the highest doses of TCDD (i.e., 3.6 and 6.3% decreases in H/W and L–E rats, respectively), most likely related to dose-dependent reductions in limb bone size and body weight gain. However, intrinsic morphological differences between strains were also observed: although the control groups of H/W and L–E rats had vaults and bases of comparable size, the face was 6.4% larger in L–E rats. Thus, although H/W rats possess an altered aryl hydrocarbon receptor (AhR) that appears to mediate and provides some resistance to TCDD exposure, their smaller reductions in facial size may also relate to strain-specific patterns of cranial development and growth. Future research will be aimed at understanding how ontogenetic factors may modulate toxic effects of prenatal and lactational exposure on the mammalian skeleton.
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Affiliation(s)
- Sabrina B Sholts
- Department of Anthropology, National Museum of Natural History, Smithsonian Institution, 10th and Constitution Avenue NW, Washington, DC 20560, USA
| | - Javier Esteban
- Instituto de Bioingeniería, Universidad Miguel Hernández, Av. de la Universidad s/n, 03202 Elche (Alicante), Spain
| | - Maria Herlin
- Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences, Lund University, Inga Marie Nilssons gata 22, SE-22100 Lund, Sweden.,Institute of Environmental Medicine, Karolinska Institutet, P.O. Box 210, SE-17177 Stockholm, Sweden
| | - Matti Viluksela
- Department of Environmental Health, National Institute for Health and Welfare, P.O. Box 95, FI-70701 Kuopio, Finland.,Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| | - Helen Håkansson
- Institute of Environmental Medicine, Karolinska Institutet, P.O. Box 210, SE-17177 Stockholm, Sweden
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El-Bakary AAES. Oral Fluids and Teeth in Toxicology. EVIDENCE-BASED FORENSIC DENTISTRY 2013:189-199. [DOI: 10.1007/978-3-642-28994-1_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Salmela E, Lukinmaa PL, Partanen AM, Sahlberg C, Alaluusua S. Combined effect of fluoride and 2,3,7,8-tetrachlorodibenzo-p-dioxin on mouse dental hard tissue formation in vitro. Arch Toxicol 2010; 85:953-63. [PMID: 21113806 DOI: 10.1007/s00204-010-0619-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 11/09/2010] [Indexed: 11/27/2022]
Abstract
Fluoride interferes with enamel matrix secretion and mineralization and dentin mineralization. The most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), also impairs dental hard tissue formation and mineralization in vitro and in vivo. Our aim was to investigate in vitro whether the combined effect of sodium fluoride (NaF) and TCDD on dental hard tissue formation is potentiative. For this purpose, mandibular first and second molar tooth germs of E18 mouse embryos were cultured for 5-12 days with NaF and TCDD alone at various concentrations (2.5, 5, 10, 12.5, 15, and 20 μM and 5, 10, 12.5, and 15 nM, respectively) to determine the highest concentrations, which alone cause no or negligible effects. Morphological changes were studied from the whole tooth photographs and histological tissue sections. The concentrations found were 15 μM for NaF and 10 nM for TCDD. While at these concentrations, the effects of NaF and TCDD alone were barely detectable, the effect of simultaneous exposure on dentin and enamel formation was overt; mineralization of predentin to dentin and enamel matrix secretion and mineralization were impaired. Immunohistochemical analysis revealed that the combined exposure modified amelogenin expression by odontoblasts. Morphology of ameloblasts and the expression of amelogenin indicated that ameloblasts were still secretory. The results show that NaF and TCDD have potentiative, harmful effects on the formation of dental hard tissues. Since children can be exposed to subclinical levels of fluoride and dioxins during early childhood, coincidently with mineralization of the first permanent teeth, this finding may have clinical significance.
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Affiliation(s)
- Eija Salmela
- Department of Pediatric and Preventive Dentistry, Institute of Dentistry, University of Helsinki, 00014 Helsinki, Finland.
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14
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Fletcher AM, Bregman CL, Woicke J, Salcedo TW, Zidell RH, Janke HE, Fang H, Janusz WJ, Schulze GE, Mense MG. Incisor degeneration in rats induced by vascular endothelial growth factor/fibroblast growth factor receptor tyrosine kinase inhibition. Toxicol Pathol 2010; 38:267-79. [PMID: 20100840 DOI: 10.1177/0192623309357950] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BMS-645737, an inhibitor of vascular endothelial growth factor (VEGF) receptor-2 and fibroblast growth factor (FGF) receptor-1, has anti-angiogenic activity and was evaluated in nonclinical studies as a treatment for cancer. This article characterizes the BMS-645737-induced clinical, gross, and histologic lesions of incisor teeth in Sprague-Dawley (SD) rats. Rats received 0 800 mg/kg BMS-645737 in a single-dose study or consecutive daily doses of 0 20 mg/kg/day in a 1-month study. The reversibility of these effects was assessed in the 1-month study. White discoloration and fracture of incisors were observed clinically and grossly in the 1-month study. In both studies, dose-dependent histopathologic lesions of incisors were degeneration and/or necrosis of odontoblasts and ameloblasts; decreased mineralization of dentin; inflammation and necrosis of the dental pulp; and edema, congestion, and hemorrhage in the pulp and periodontal tissue adjacent to the enamel organ. Partial recovery was observed at lower doses after a two-week dose-free period in the one-month study. Drug-induced incisor lesions were considered to be related to the pharmacologic inhibitory effects on VEGF and FGF signaling, that is, inhibition of growth and maintenance of small-diameter vessels that support the formation of dentin and enamel in growing teeth and/or to perturbances of function of odontoblasts and ameloblasts or their precursors.
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Affiliation(s)
- Anthony M Fletcher
- Drug Safety Evaluation, Bristol-Myers Squibb Company, Syracuse, New York, NY 13221-4755, USA.
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15
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Yoshizawa K, Heatherly A, Malarkey DE, Walker NJ, Nyska A. A critical comparison of murine pathology and epidemiological data of TCDD, PCB126, and PeCDF. Toxicol Pathol 2007; 35:865-79. [PMID: 18098033 PMCID: PMC2623249 DOI: 10.1080/01926230701618516] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, or dioxin) and dioxin-like compounds (DLCs) induce numerous toxicities, including developmental, endocrine, immunological, and multi-organ carcinogenic, in animals and/or humans. Multiple studies completed by the National Toxicology Program (NTP) focused on the effects caused in Harlan Sprague-Dawley rats by specific DLCs, among them the prototypical dioxin, TCDD. Because humans are exposed daily to a combination of DLCs, primarily via ingestion of food, the Toxic Equivalency Factor (TEF) was developed in order to evaluate health hazards caused by these mixtures. Herein we review the pathological effects reported in humans exposed to TCDD; 3,3',4,4',5-pentachlorobiphenyl (PCB 126); and 2,3,4,7,8,-pentachlorodibenzofuran (PeCDF) and compare them to similar changes seen in NTP murine studies performed with the same compounds. While there were differences in specific pathologies observed, clear consistency in the target organs affected (liver, oral cavity, cardiovascular system, immune system, thyroid, pancreas, and lung) could be seen in both human studies and rodent toxicity and carcinogenicity investigations.
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Affiliation(s)
- Katsuhiko Yoshizawa
- Toxicologic Pathology, Drug Safety Research Laboratories, Astellas Pharma Inc., Yodogawa, Osaka, Japan
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16
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Keller JM, Huang JC, Huet-Hudson Y, Leamy LJ. The effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on molar and mandible traits in congenic mice: A test of the role of the Ahr locus. Toxicology 2007; 242:52-62. [DOI: 10.1016/j.tox.2007.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 08/28/2007] [Accepted: 09/06/2007] [Indexed: 11/30/2022]
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17
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Alaluusua S, Lukinmaa PL. Developmental dental toxicity of dioxin and related compounds--a review. Int Dent J 2007; 56:323-31. [PMID: 17243464 DOI: 10.1111/j.1875-595x.2006.tb00336.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Non-halogenated polycyclic aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, or dioxins), and polychlorinated biphenyls (PCBs) are wide-spread environmental pollutants that have unequivocal adverse effects on different species, including humans. Accidental exposure of children to high amounts of PCDD/Fs has been found to be associated with developmental enamel defects and missing permanent teeth. An association between dioxin exposure via mother's milk and developmental mineralisation defects in permanent first molars was also found in otherwise healthy Finnish children born in the late 1980s but not in those born in the late 1990s. Results of experimental animal studies in vivo and in vitro are compatible with findings in human teeth. In addition to the dose, dental effects of the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), essentially depend on the stage of tooth development at the time of exposure. Accordingly, TCDD arrests early rat and mouse molar tooth development and in more advanced teeth it interferes with mineralisation of enamel and dentine and arrests root development. Expression of the specific dioxin receptor (AhR) in dental cells at TCDD-sensitive stages of tooth development suggests that the dental, like other developmental effects of TCDD, are mediated by the AhR. Early effects also depend on the epidermal growth factor receptor and involve enhanced apoptosis. The lowest TCDD dose (30ng/kg) causing adverse dental effects in rats has been estimated to result in maternal tissue levels approaching the high end of human background range and human milk PCDD/F levels that were associated with enamel defects in children. However, because of the uniform and clear decline in background dioxin and PCB levels in mother's milk during the last twenty years, dioxins are currently likely to be of small or no account as regards developmental dental defects in children. Even so, this is not the case after heavy exposure and little is known about the possible synergistic effects of these toxicants with other chemicals interfering with tooth development.
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Affiliation(s)
- Satu Alaluusua
- Department of Pediatric and Preventive Dentistry, Institute of Dentistry, University of Helsinki, Finland.
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18
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Keller JM, Huet-Hudson YM, Leamy LJ. Qualitative effects of dioxin on molars vary among inbred mouse strains. Arch Oral Biol 2006; 52:450-4. [PMID: 17141729 PMCID: PMC1916485 DOI: 10.1016/j.archoralbio.2006.10.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Revised: 10/16/2006] [Accepted: 10/21/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE We evaluated the effects of different levels of the potent environmental toxicant and teratogen, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on molar development in mice in six inbred strains, all with TCDD responsive Ahr alleles. DESIGN Pregnant females were exposed on gestation day 13 to 4 different levels of TCDD (control, 0.01, 0.1 and 1.0 microg/kg) and their offspring were examined for the frequency of missing third molars (M3s) and for differences in first mandibular molar (M1) cuspal morphology. RESULTS Missing M3s were prevalent only in mice in two strains, C3H/HeJ and CBA/J, and their frequency significantly increased with increasing TCDD exposure. The frequency of the M1 variant was high in mice in only one strain, C57BL/10J, and was significantly higher in the treated compared with the control group. CONCLUSIONS Inbred mice strains exhibited differential responses to TCDD suggesting that there is a genetic component, beyond Ahr differences, mediating the effects of TCDD on molar development.
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MESH Headings
- Alleles
- Animals
- Anodontia/chemically induced
- Basic Helix-Loop-Helix Transcription Factors
- Environmental Exposure
- Environmental Pollutants/toxicity
- Female
- Gestational Age
- Male
- Mice
- Mice, Inbred A
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Inbred Strains
- Molar/abnormalities
- Molar/drug effects
- Molar, Third/abnormalities
- Molar, Third/drug effects
- Odontogenesis/drug effects
- Polychlorinated Dibenzodioxins/toxicity
- Pregnancy
- Prenatal Exposure Delayed Effects
- Receptors, Aryl Hydrocarbon/drug effects
- Receptors, Aryl Hydrocarbon/genetics
- Teratogens/toxicity
- Tooth Crown/abnormalities
- Tooth Crown/drug effects
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Affiliation(s)
- J M Keller
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001, USA.
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19
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Maurin JC, Bleicher F, Magloire H. Conséquences cliniques des effets des dioxines sur le développement dentaire. Arch Pediatr 2005; 12:1636-40. [PMID: 16084703 DOI: 10.1016/j.arcped.2005.06.012] [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: 02/20/2005] [Accepted: 06/17/2005] [Indexed: 11/19/2022]
Abstract
Commonly designed by the term "dioxins", polychlorinated aromatic hydrocarbons are environmental pollutants leading to several toxic effects during development and growth in embryo and child. The general consequences of dioxin exposure are particularly well-documented whereas only few data are mentioned by the experts concerning tooth development. However, studies performed in rodents have shown many disruptions during odontogenesis and enamel mineralisation. Moreover, recent epidemiological studies have demonstrated in human the incidence of dioxin exposure on enamel hypomineralisation and hypodontia. The aim of this review is to report recent data about consequences of dioxin exposure on tooth development, tooth being considered as a biological marker of potential dioxin poisoning.
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Affiliation(s)
- J C Maurin
- Laboratoire Développement et régénération des tissus dentaires Inserm, ESPRI, EA 1892, IFR 62, faculté d'odontologie, université Lyon-I, rue Guillaume-Paradin, 69372 Lyon cedex 08, France
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20
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Nyska A, Yoshizawa K, Jokinen MP, Brix AE, Sells DM, Wyde ME, Orzech DP, Kissling GE, Walker NJ. Olfactory epithelial metaplasia and hyperplasia in female Harlan Sprague-Dawley rats following chronic treatment with polychlorinated biphenyls. Toxicol Pathol 2005; 33:371-7. [PMID: 15805076 DOI: 10.1080/01926230590930209] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The National Toxicology Program recently completed a series of studies to evaluate the relative potency for toxicity and carcinogenicity of several polyhalogenated aromatic hydrocarbons including dioxin-like compounds (DLCs) and polychlorinated biphenyls. Female Sprague-Dawley rats were administered by gavage for up to 2 years with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD); 3,3',4,4',5-pentachlorobiphenyl (PCB126); 2,3,4,7,8-pentachlorodibenzofuran (PeCDF); 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153); a tertiary mixture of TCDD, PCB126, and PeCDF; a binary mixture of PCB126 and 153; or a binary mixture of PCB126 and 2,3',4,4',5-pentachlorobiphenyl (PCB118); control animals received corn oil-acetone vehicle (99:1) alone. Nasal epithelial changes were observed only in animals exposed for 2 years to the higher doses of the binary mixtures of PCB126 + PCB153 (1000 ng/kg and 1000 microg/kg) and PCB126 + PCB118 (216 and 360 ng TCDD equivalents/kg). In both studies, the changes were of the same nonneoplastic nature, localized to nasal sections II and III located, respectively, at the level of the incisive papilla anterior to the first palatial ridge (section II) and through the middle of the second molar teeth (section III). The changes consisted of hyperplasia of the respiratory epithelium (level II) and metaplasia of olfactory epithelium to respiratory epithelium with further hyperplasia of the metaplastic respiratory epithelium (levels II and III). Variable amounts of acute inflammatory exudate appeared within the lumen of the nasal cavity, overlying the affected epithelium. Occasionally, the inflammation eroded through the skull and into the adjacent olfactory bulbs.
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Affiliation(s)
- Abraham Nyska
- Laboratory of Experimental Pathology National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709-9998, USA.
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21
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Yasuda I, Yasuda M, Sumida H, Tsusaki H, Arima A, Ihara T, Kubota S, Asaoka K, Tsuga K, Akagawa Y. In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects tooth development in rhesus monkeys. Reprod Toxicol 2005; 20:21-30. [PMID: 15808782 DOI: 10.1016/j.reprotox.2004.12.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 12/03/2004] [Accepted: 12/20/2004] [Indexed: 11/26/2022]
Abstract
We thought to validate the current tolerable daily intake (TDI) value for dioxin (4 pg/kg) in Japan. Pregnant rhesus monkeys received an initial dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 0, 30, or 300 ng/kg subcutaneously) on day 20 of gestation; the dams received additional injection of 5% of the initial dose every 30 days until day 90 after delivery. The teeth of stillborn, postnatally dead, and surviving offspring (now approximately 4 years old) were evaluated. None of the offspring in the 0 and 30 ng/kg groups (n=17 and 15, respectively) had tooth abnormalities, whereas 10 of 17 in the 300 ng/kg had them. These findings suggest the lowest-observed adverse-effect level (LOAEL) for TCDD in the rhesus monkey is between 30 and 300 ng/kg, and probably is close to that for rodents (86 ng/kg) on which the current TDI was based. It is reasonable to conclude that the current TDI needs no immediate modification.
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Affiliation(s)
- Iku Yasuda
- Department of Advanced Prosthodontics, Division of Cervico-Gnathostomatology, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8553, Japan
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22
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Alaluusua S, Calderara P, Gerthoux PM, Lukinmaa PL, Kovero O, Needham L, Patterson DG, Tuomisto J, Mocarelli P. Developmental dental aberrations after the dioxin accident in Seveso. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:1313-8. [PMID: 15345345 PMCID: PMC1247522 DOI: 10.1289/ehp.6920] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Children's developing teeth may be sensitive to environmental dioxins, and in animal studies developing teeth are one of the most sensitive targets of toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Twenty-five years after the dioxin accident in Seveso, Italy, 48 subjects from the contaminated areas (zones A and B) and in patches lightly contaminated (zone R) were recruited for the examination of dental and oral aberrations. Subjects were randomly invited from those exposed in their childhood and for whom frozen serum samples were available. The subjects were frequency matched with 65 subjects from the surrounding non-ABR zone for age, sex, and education. Concentrations of TCDD in previously analyzed plasma samples (zone ABR subjects only) ranged from 23 to 26,000 ng/kg in serum lipid. Ninety-three percent (25 of 27) of the subjects who had developmental enamel defects had been < 5 years of age at the time of the accident. The prevalence of defects in this age group was 42% (15 of 36) in zone ABR subjects and 26% (10 of 39) in zone non-ABR subjects, correlating with serum TCDD levels (p = 0.016). Hypodontia was seen in 12.5% (6 of 48) and 4.6% (3 of 65) of the zone ABR and non-ABR subjects, respectively, also correlating with serum TCDD level (p = 0.05). In conclusion, developmental dental aberrations were associated with childhood exposure to TCDD. In contrast, dental caries and periodontal disease, both infectious in nature, and oral pigmentation and salivary flow rate were not related to the exposure. The results support our hypothesis that dioxins can interfere with human organogenesis.
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Affiliation(s)
- Satu Alaluusua
- Department of Pedodontics and Orthodontics, Institute of Dentistry, University of Helsinki, Helsinki, Finland.
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23
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Partanen AM, Kiukkonen A, Sahlberg C, Alaluusua S, Thesleff I, Pohjanvirta R, Lukinmaa PL. Developmental toxicity of dioxin to mouse embryonic teeth in vitro: arrest of tooth morphogenesis involves stimulation of apoptotic program in the dental epithelium. Toxicol Appl Pharmacol 2004; 194:24-33. [PMID: 14728976 DOI: 10.1016/j.taap.2003.08.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Previous studies have shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can arrest molar tooth development in rats after in utero and lactational exposure, and that the sensitive stage is temporally restricted. To define the stage in which TCDD is able to arrest tooth development and the cellular background of the effect, mouse embryonic molar tooth explants including various early developmental stages from initiation to late cap stage were exposed to TCDD in organ culture. TCDD did not inhibit morphogenesis of the first molar teeth including the early bud-staged E12 first molars, but the teeth were smaller than in control cultures. Accordingly, the second molars underwent morphogenesis in the presence of TCDD when explanted at E15 when they were at the bud stage. TCDD arrested their development when explanted at E14 when they had not yet reached the early bud stage. Immunohistochemical localization of incorporated bromodeoxyuridine in cultured E14 teeth showed that TCDD did not affect cell proliferation. Localization of apoptosis by terminal deoxynucleotidyl transferase (TdT)-mediated nick end labeling (TUNEL) method revealed that TCDD enhanced apoptosis of dental epithelial cells, especially in the dental lamina of both the first and second molars, and in the inner dental epithelium at the cusp tips of the first molars. Thus, TCDD can arrest tooth development in vitro if the exposure starts at the initiation stage, whereas exposure at later stages leads to smaller tooth size and deformation of cuspal morphology. TCDD interferes with tooth development by stimulating apoptosis in those cells of the dental epithelium, which are predetermined to undergo apoptosis during normal development.
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Affiliation(s)
- Anna Maija Partanen
- Department of Pedodontics and Orthodontics, Institute of Dentistry, University of Helsinki, FIN-00014 Helsinki, Finland.
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24
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Simanainen U, Tuomisto JT, Tuomisto J, Viluksela M. Dose-response analysis of short-term effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin in three differentially susceptible rat lines. Toxicol Appl Pharmacol 2003; 187:128-36. [PMID: 12649045 DOI: 10.1016/s0041-008x(02)00068-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Line A, B, and C rats were selectively bred from TCDD-resistant Han/Wistar (Kuopio; H/W) and TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. Line A rats are the most resistant to TCDD acute lethality followed by line B and line C rats. The resistance in line A rats is associated with a mutated H/W-type aryl hydrocarbon receptor (Ahr) allele (Ahr(hw)) and in line B rats the resistance is associated with an allele of an unknown gene B (B(hw)), while line C rats are almost as sensitive to TCDD as L-E rats. The dose-responses of characteristic short-term effects (day 8 postexposure) of TCDD were used to evaluate the efficacy (magnitude of effect) and potency relationships between these lines. Line A rats showed similar efficacies as line C (line A:line C efficacy ratio more than 0.7) for thymus weight, EROD activity, and incisor tooth defects. In contrast, efficacies in line A were decreased (efficacy ratios 0.19-0.37) for body weight change, serum bilirubin, and FFA levels, and serum ASAT activity. For most endpoints the efficacies in line B rats seem to be lower than in line C rats. The potencies were close to each other in line A and B rats, but somewhat lower than in line C rats. The results support our previous concept of two different AHR-mediated signaling pathways leading to dioxin type I and type II endpoints. Rats with the Ahr(hw/hw) genotype show a markedly decreased efficacy for type II endpoints, but B(hw) allele had only a minor effect on efficacies for most endpoints. Both H/W-type resistance alleles also decreased the potency of TCDD. However, the potency differences in short-term toxicity seem not to explain, at least alone, the differences seen in acute lethality among the rat lines.
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Affiliation(s)
- Ulla Simanainen
- National Public Health Institute, Department of Environmental Health, P.O. Box 95, FIN-70701 Kuopio, Finland.
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