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Immune System Acts on Orthodontic Tooth Movement: Cellular and Molecular Mechanisms. BIOMED RESEARCH INTERNATIONAL 2022; 2022:9668610. [PMID: 36330460 PMCID: PMC9626206 DOI: 10.1155/2022/9668610] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/05/2022] [Accepted: 09/29/2022] [Indexed: 12/03/2022]
Abstract
Orthodontic tooth movement (OTM) is a tissue remodeling process based on orthodontic force loading. Compressed periodontal tissues have a complicated aseptic inflammatory cascade, which are considered the initial factor of alveolar bone remodeling. Since skeletal and immune systems shared a wide variety of molecules, osteoimmunology has been generally accepted as an interdisciplinary field to investigate their interactions. Unsurprisingly, OTM is considered a good mirror of osteoimmunology since it involves immune reaction and bone remolding. In fact, besides bone remodeling, OTM involves cementum resorption, soft tissue remodeling, orthodontic pain, and relapse, all correlated with immune cells and/or immunologically active substance. The aim of this paper is to review the interaction of immune system with orthodontic tooth movement, which helps gain insights into mechanisms of OTM and search novel method to short treatment period and control complications.
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Wisnewski AV, Cooney R, Hodgson M, Giese K, Liu J, Redlich CA. Severe asthma and death in a worker using methylene diphenyl diisocyanate MDI asthma death. Am J Ind Med 2022; 65:166-172. [PMID: 35028957 PMCID: PMC8846433 DOI: 10.1002/ajim.23323] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/06/2022]
Abstract
Diisocyanates are well-recognized to cause occupational asthma, yet diisocyanate asthma can be challenging to diagnose and differentiate from asthma induced by other allergens. The present study assesses the potential contribution of methylene diphenyl diisocyanate (MDI) to a workplace fatality. Examination of medical records, tissue, and blood from the deceased worker were undertaken. Formalin-fixed paraffin-embedded lung tissue sections were assessed through histologic and immunochemical stains. Serum MDI-specific IgE and IgG, and total IgE, were measured by enzyme-linked immunosorbent assays and/or Western blot. Information about potential chemical exposures and industrial processes in the workplace were provided by the employer and through interviews with co-workers. Review of the worker's medical records, occupational history, and autopsy findings were consistent with severe asthma as the cause of death, and ruled out cardiac disease, pulmonary embolism, or stroke. Lung pathology revealed hallmarks of asthma including smooth muscle hypertrophy, eosinophilia, basement membrane thickening, and mucus plugging of bronchioles. Immunochemical staining for MDI was positive in the thickened basement membrane of inflamed airways. MDI-specific serum IgE and IgG were significantly elevated and demonstrated specificity for MDI versus other diisocyanates, however, total serum IgE was normal (24 IU/ml). The workplace had recently introduced MDI into the foundry as part of a new process, but MDI air levels had not been measured. Respirators were not required. In summary, post-mortem findings support the diagnosis of diisocyanate asthma and a severe asthma attack at work as the cause of death in a foundry worker.
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Affiliation(s)
- Adam V Wisnewski
- Department of Internal Medicine, Yale University
School of Medicine, New Haven, CT, USA
| | - Ryan Cooney
- Occupational Safety and Health Administration,
Washington, DC, USA
| | - Michael Hodgson
- Occupational Safety and Health Administration,
Washington, DC, USA
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Wisnewski AV, Nassar AF, Liu J, Bello D. Dilysine-Methylene Diphenyl Diisocyanate (MDI), a Urine Biomarker of MDI Exposure? Chem Res Toxicol 2019; 32:557-565. [PMID: 30724074 PMCID: PMC6465083 DOI: 10.1021/acs.chemrestox.8b00262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Biomonitoring of methylene diphenyl diisocyanate (MDI) in urine may be useful in industrial hygiene and exposure surveillance approaches toward disease (occupational asthma) prevention and in understanding pathways by which the internalized chemical is excreted. We explored possible urine biomarkers of MDI exposure in mice after respiratory tract exposure to MDI, as glutathione (GSH) reaction products (MDI-GSH), and after skin exposure to MDI dissolved in acetone. LC-MS analyses of urine identified a unique m/ z 543.29 [M + H]+ ion from MDI-exposed mice but not from controls. The m/ z 543.29 [M + H]+ ion was detectable within 24 h of a single MDI skin exposure and following multiple respiratory tract exposures to MDI-GSH reaction products. The m/ z 543.29 [M + H]+ ion possessed properties of dilysine-MDI, including (a) an isotope distribution pattern for a molecule with the chemical formula C27H38N6O6, (b) the expected collision-induced dissociation (CID) fragmentation pattern upon MS/MS, and (c) a retention time in reversed-phase LC-MS identical to that of synthetic dilysine-MDI. Further MDI-specific Western blot studies suggested albumin (which contains multiple dilysine sites susceptible to MDI carbamylation) as a possible source for dilysine-MDI and the presence of MDI-conjugated albumin in urine up to 6 days after respiratory tract exposure. Two additional [M + H]+ ions ( m/ z 558.17 and 863.23) were found exclusively in urine of mice exposed to MDI-GSH via the respiratory tract and possessed characteristics of previously described cyclized MDI-GSH and oxidized glutathione (GSSG)-MDI conjugates, respectively. Together the data identify urinary biomarkers of MDI exposure in mice and possible guidance for future translational investigation.
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Affiliation(s)
- Adam V. Wisnewski
- Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Ala F Nassar
- Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Jian Liu
- Department of Internal Medicine, Yale University, New Haven, CT, USA
| | - Dhimiter Bello
- Department of Public Health, University of Massachusetts, Lowell, MA, USA
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Harari H, Bello D, Woskie S, Redlich C. Development of an Interception Glove Sampler for Skin Exposures to Aromatic Isocyanates. ANNALS OF OCCUPATIONAL HYGIENE 2016; 60:1092-1103. [PMID: 27694341 DOI: 10.1093/annhyg/mew052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 06/24/2016] [Accepted: 07/06/2016] [Indexed: 12/30/2022]
Abstract
OBJECTIVES Skin is an important exposure route for isocyanate chemicals and contributes to systemic sensitization. Methods for assessing skin exposure are currently limited and generally rely upon removal (e.g. tape-strip) techniques prone to underestimation. The aim of this study is to (i) develop and field test an interception-based hand exposure sampler to monitor potential skin exposure to isocyanates in the workplace, (ii) to develop an analytical method based on ultra-high-performance liquid chromatography-UV absorbance-tandem mass spectrometry (UHPLC-UV-MS/MS) for analyzing glove samples; and (iii) compare it with tape-stripping skin sampling method. METHODS Laboratory investigations assessed different glove materials/fabrics, methods for impregnating with 1-(9-anthracenylmethyl)piperazine (MAP) derivatizing agent, methylene diphenyl diisocyanate (MDI) uptake and recovery, and durability. Following use, gloves were dissected into sections corresponding to different spatial regions (finger, palm) and analyzed using a newly developed UHPLC-UV-MS/MS method capable of differentiating and quantitating different MDI isomers with high sensitivity. Performance of the glove sampler was further assessed in a pilot field study using six workers. RESULTS A MAP-impregnated thin cotton glove sampler and UHPLC-UV-MS/MS analytical method for detecting MDI were successfully developed in laboratory studies. In subsequent field studies, a total of 384 samples from 14 glove pairs identified full-shift exposures ranged from 0.01 to 306 µg of 4,4'-MDI/worker for each hand. Surface area adjusted MDI values measured with the glove sampler (0.13-572ng MDI cm-2) were considerably higher (~400-fold) than values obtained with tape stripping. CONCLUSION A glove sampler and a novel UHPLC-UV-MS/MS analytical method were developed to quantitatively measure MDI skin exposure. The novel interception technique overcomes inherent limitations of removal techniques for measuring isocyanate skin exposure and may be useful in exposure surveillance and future research on isocyanate's health risks.
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Affiliation(s)
- Homero Harari
- 1.Work Environment Department, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA; .,2.Yale Occupational and Environmental Medicine Program, Yale School of Medicine, 135 College Street, New Haven, CT 06510, USA
| | - Dhimiter Bello
- 1.Work Environment Department, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA
| | - Susan Woskie
- 1.Work Environment Department, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA
| | - Carrie Redlich
- 2.Yale Occupational and Environmental Medicine Program, Yale School of Medicine, 135 College Street, New Haven, CT 06510, USA
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Sabbioni G, Dongari N, Kumar A, Baur X. Determination of albumin adducts of 4,4'-methylenediphenyl diisocyanate after specific inhalative challenge tests in workers. Toxicol Lett 2016; 260:46-51. [PMID: 27521498 DOI: 10.1016/j.toxlet.2016.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 08/08/2016] [Accepted: 08/09/2016] [Indexed: 12/31/2022]
Abstract
4,4'-Methylenediphenyl diisocyanate (MDI) is the most important isocyanate used in the industry. Lung sensitization with bronchial asthma is the main disorder in exposed workers. Albumin adducts of MDI might be involved in specific immunological reactions. MDI adducts with lysine (MDI-Lys) of albumin have been found in MDI-workers and construction workers. MDI-Lys is an isocyanate-specific adduct of MDI with albumin. In the present study, we report MDI-adducts in workers undergoing diagnostic MDI challenge tests. The workers were exposed for 2h to 5ppb of MDI. The adduct levels increase significantly after the exposure to MDI in the challenge chamber. About 0.6% of the dose was bound to albumin. So far, only urinary metabolites of MDI were measured to monitor isocyanate workers. However, such urinary metabolites are not isocyanate specific. Therefore, we propose to measure albumin adducts for monitoring MDI exposed subjects.
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Affiliation(s)
- Gabriele Sabbioni
- Institute of Environmental and Occupational Toxicology, Casella Postale 108, CH-6780 Airolo, Switzerland; Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität, D-80336 München, Germany; Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St., Suite 2100, New Orleans, LA 70112, USA.
| | - Nagaraju Dongari
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St., Suite 2100, New Orleans, LA 70112, USA; National Laboratories Inc., 3011 W. Grand Blvd, Suite 310, Detroit, MI 48202, USA
| | - Anoop Kumar
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal St., Suite 2100, New Orleans, LA 70112, USA
| | - Xaver Baur
- Institut für Arbeitsmedizin, Charité Universitätsmedizin Berlin, Thielallee 69, 14195 Berlin, Germany
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Sabbioni G, Dongari N, Sepai O, Kumar A. Determination of albumin adducts of 4,4'-methylenediphenyl diisocyanate in workers of a 4,4'-methylenedianiline factory. Biomarkers 2016; 21:731-738. [PMID: 27145381 DOI: 10.3109/1354750x.2016.1172117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lung sensitization and asthma are the main health effects of 4,4'-methylenediphenyl diisocyanate (MDI). Albumin adducts (isocyanate specific adducts) of MDI might be involved in the etiology of sensitization reactions. Albumin adducts of MDI have been found in subjects classified as 4,4'-methylenedianiline (MDA) workers. The mean adduct levels in these MDA-workers were 1.5 times higher than in MDI-workers of the same company. MDA-specific hemoglobin adducts, were present ten times more in the MDA-workers than in the MDI-workers. MDA-workers with specific work task had significantly higher albumin adduct levels.
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Affiliation(s)
- Gabriele Sabbioni
- a Institute of Environmental and Occupational Toxicology , Airolo , Switzerland.,b Walther-Straub-Institut für Pharmakologie und Toxikologie , Ludwig-Maximilians-Universität , München , Germany.,c Department of Environmental Health Sciences, School of Public Health and Tropical Medicine , Tulane University , New Orleans , LA , USA
| | - Nagaraju Dongari
- c Department of Environmental Health Sciences, School of Public Health and Tropical Medicine , Tulane University , New Orleans , LA , USA.,d National Laboratories Inc , Detroit , MI , USA
| | - Ovnair Sepai
- e Insitutut für Pharmakologie und Toxikologie , Julius-Maximilians-Universität Würzburg , Würzburg , Germany
| | - Anoop Kumar
- c Department of Environmental Health Sciences, School of Public Health and Tropical Medicine , Tulane University , New Orleans , LA , USA
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Faniband MH, Littorin M, Ekman E, Jönsson BAG, Lindh CH. LC-MS-MS Analysis of Urinary Biomarkers of Imazalil Following Experimental Exposures. J Anal Toxicol 2015; 39:691-7. [PMID: 26324206 PMCID: PMC4626574 DOI: 10.1093/jat/bkv100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Imazalil (IMZ) is a fungicide used in the cultivation of vegetables, such as cucumbers, in green houses or post-harvest on fruit to avoid spoilage due to fungal growth. Agricultural workers can be occupationally exposed to IMZ and the general public indirectly by the diet. The purpose of this study was to develop and validate an LC-MS-MS method for the analysis of IMZ in human urine. The method used electrospray ionization and selected reaction monitoring in the positive mode. Excellent linearity was observed in the range 0.5-100 ng/mL. The limit of detection of the method was 0.2 ng/mL, and the limit of quantitation 0.8 ng/mL. The method showed good within-run, between-run and between-batch precision, with a coefficient of variation <15%. The method was applied to analyze urine samples obtained from two human volunteers following experimental oral and dermal exposure. The excretion of IMZ seemed to follow a two-compartment model and first-order kinetics. In the oral exposure, the elimination half-life of IMZ in the rapid excretion phase was 2.6 and 1.9 h for the female and the male volunteer, respectively. In the slower excretion phase, it was 7.6 and 13 h, respectively. In the dermal exposure, the excretion seemed to follow a single-compartment model and first-order kinetics. The elimination half-life was 10 and 6.6 h for the female and the male volunteer, respectively. Although the study is limited to two volunteers, some information on basic toxicokinetics and metabolism of IMZ in humans is presented.
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Affiliation(s)
- Moosa H Faniband
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden
| | - Margareta Littorin
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden
| | - Eva Ekman
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden
| | - Bo A G Jönsson
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden
| | - Christian H Lindh
- Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Faculty of Medicine, Lund University, SE-221 85 Lund, Sweden
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Henriks-Eckerman ML, Mäkelä EA, Laitinen J, Ylinen K, Suuronen K, Vuokko A, Sauni R. Role of dermal exposure in systemic intake of methylenediphenyl diisocyanate (MDI) among construction and boat building workers. Toxicol Lett 2014; 232:595-600. [PMID: 25542146 DOI: 10.1016/j.toxlet.2014.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 11/19/2022]
Abstract
The causal relationship between inhalation exposure to methylenediphenyl diisocyanate (MDI) and the risk of occupational asthma is well known, but the role of dermal exposure and dermal uptake of MDI in this process is still unclear. The aims of this study were to measure dermal exposure to and the dermal uptake of MDI among workers (n=24) who regularly handle MDI-urethanes. Dermal exposure was measured by the tape-strip technique from four sites on the dominant hand and arm. The workers with the highest exposure (n=5) were biomonitored immediately after their work shift, in the evening and the next morning, using urinary 4,4´methylenedianiline (MDA) as a marker. Dermal uptake was evaluated by comparing workers' MDA excretions both when they were equipped with respiratory protective devices (RPDs) and when they did not use them. The measured amounts of MDI on their hands varied from below 0.1 to 17 μg/10 cm(2) during the test. MDI concentrations were in the range of 0.08 to 27 μg m(-3) in the breathing zone outside the RPDs. MDA concentrations varied from 0.1 to 0.2 μmol mol(-1) creatinine during the test period. The decreasing effect of RPDs on inhalation exposure was absent in the next morning urine samples; this excretion pattern might be an indication of dermal uptake of MDI.
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Affiliation(s)
| | - Erja A Mäkelä
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Juha Laitinen
- Finnish Institute of Occupational Health, Kuopio, Finland
| | | | - Katri Suuronen
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Aki Vuokko
- Finnish Institute of Occupational Health, Helsinki, Finland
| | - Riitta Sauni
- Finnish Institute of Occupational Health, Tampere, Finland
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A New Penetration Test Method: Protection Efficiency of Glove and Clothing Materials Against Diphenylmethane Diisocyanate (MDI). ACTA ACUST UNITED AC 2014; 59:221-31. [DOI: 10.1093/annhyg/meu078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nayak AP, Hettick JM, Siegel PD, Anderson SE, Long CM, Green BJ, Beezhold DH. Toluene diisocyanate (TDI) disposition and co-localization of immune cells in hair follicles. Toxicol Sci 2014; 140:327-37. [PMID: 24798378 DOI: 10.1093/toxsci/kfu079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Diisocyanates (dNCOs) are potent chemical allergens utilized in various industries. It has been proposed that skin exposure to dNCOs produces immune sensitization leading to work-related asthma and allergic disease. We examined dNCOs sensitization by using a dermal murine model of toluene diisocyanate (TDI) exposure to characterize the disposition of TDI in the skin, identify the predominant haptenated proteins, and discern the associated antigen uptake by dendritic cells. Ears of BALB/c mice were dosed once with TDI (0.1% or 4% v/v acetone). Ears and draining lymph nodes (DLNs) were excised at selected time points between 1 h and 15 days post-exposure and were processed for histological, immunohistochemical, and proteomic analyses. Monoclonal antibodies specific for TDI-haptenated protein (TDI-hp) and antibodies to various cell markers were utilized with confocal microscopy to determine co-localization patterns. Histopathological changes were observed following exposure in ear tissue of mice dosed with 4% TDI/acetone. Immunohistochemical staining demonstrated TDI-hp localization in the stratum corneum, hair follicles, and sebaceous glands. TDI-hp were co-localized with CD11b(+) (integrin αM/Mac-1), CD207(+) (langerin), and CD103(+) (integrin αE) cells in the hair follicles and in sebaceous glands. TDI-hp were also identified in the DLN 1 h post-exposure. Cytoskeletal and cuticular keratins along with mouse serum albumin were identified as major haptenated species in the skin. The results of this study demonstrate that the stratum corneum, hair follicles, and associated sebaceous glands in mice are dendritic cell accessible reservoirs for TDI-hp and thus identify a mechanism for immune recognition following epicutaneous exposure to TDI.
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Affiliation(s)
- Ajay P Nayak
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
| | - Justin M Hettick
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
| | - Paul D Siegel
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
| | - Stacey E Anderson
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
| | - Carrie M Long
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505 Department of Microbiology, Immunology and Cell Biology, School of Medicine, West Virginia University, Morgantown, West Virginia 26506
| | - Brett J Green
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
| | - Donald H Beezhold
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505
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Premaraj T, Simet S, Beatty M, Premaraj S. Oral epithelial cell reaction after exposure to Invisalign plastic material. Am J Orthod Dentofacial Orthop 2014; 145:64-71. [PMID: 24373656 DOI: 10.1016/j.ajodo.2013.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/01/2013] [Accepted: 09/01/2013] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Invisalign plastic aligners (Align Technology, Santa Clara, Calif) are used to correct malocclusions. The aligners wrap around the teeth and are in contact with gingival epithelium during treatment. The purpose of this study was to evaluate the cellular responses of oral epithelium exposed to Invisalign plastic in vitro. METHODS Oral epithelial cells were exposed to eluate obtained by soaking Invisalign plastic in either saline solution or artificial saliva for 2, 4, and 8 weeks. Cells grown in media containing saline solution or saliva served as controls. Morphologic changes were assessed by light microscopy. The 3-[4, 5-dimethythiazol- 2-yl]-2, 5-diphenyl tetrazolium bromide assay and flow cytometry were used to determine cell viability and membrane integrity, respectively. Cellular adhesion and micromotion of epithelial cells were measured in real time by electrical cell-substrate impedance sensing. RESULTS Cells exposed to saline-solution eluate appeared rounded, were lifted from the culture plates, and demonstrated significantly increased metabolic inactivity or cell death (P <0.05). Saliva eluates did not induce significant changes in cell viability compared with untreated cells. Flow cytometry and electric cell-substrate impedance sensing showed that cells treated with saline-solution eluate exhibited compromised membrane integrity, and reduced cell-to-cell contact and mobility when compared with saliva-eluate treatment. CONCLUSIONS Exposure to Invisalign plastic caused changes in viability, membrane permeability, and adhesion of epithelial cells in a saline-solution environment. Microleakage and hapten formation secondary to compromised epithelial integrity might lead to isocyanate allergy, which could be systemic or localized to gingiva. However, these results suggest that saliva might offer protection.
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Affiliation(s)
- Thyagaseely Premaraj
- Assistant professor, Orthodontic Section, Department of Growth and Development, College of Dentistry, University of Nebraska Medical Center, Lincoln, Neb.
| | - Samantha Simet
- Postdoctoral research associate, Department of Internal Medicine, Pulmonary, Critical Care, Sleep & Allergy Division, University of Nebraska Medical Center, Omaha, Neb
| | - Mark Beatty
- Associate professor and graduate program director, Orthodontic Section, Department of Growth and Development, College of Dentistry, University of Nebraska Medical Center, Lincoln, Neb
| | - Sundaralingam Premaraj
- Professor and director, Section of Biomaterials, Department of Adult Restorative Dentistry, College of Dentistry, University of Nebraska Medical Center, Lincoln, Neb
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Arrandale V, Meijster T, Pronk A, Doekes G, Redlich CA, Holness DL, Heederik D. Skin symptoms in bakery and auto body shop workers: associations with exposure and respiratory symptoms. Int Arch Occup Environ Health 2012; 86:167-75. [PMID: 22411214 PMCID: PMC3555349 DOI: 10.1007/s00420-012-0760-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 03/01/2012] [Indexed: 11/25/2022]
Abstract
Purpose Despite the importance of skin exposure, studies of skin symptoms in relation to exposure and respiratory symptoms are rare. The goals of this study were to describe exposure–response relationships for skin symptoms, and to investigate associations between skin and respiratory symptoms in bakery and auto body shop workers. Methods Data from previous studies of bakery and auto body shop workers were analyzed. Average exposure estimates for wheat allergen and isocyanates were used. Generalized linear models were constructed to describe the relationships between exposure and skin symptoms, as well as between skin and respiratory symptoms. Results Data from 723 bakery and 473 auto body shop workers were analyzed. In total, 5.3 % of bakery and 6.1 % of auto body shop workers were female; subjects’ mean age was 39 and 38 years, respectively. Exposure–response relationships were observed in auto body shop workers for itchy or dry skin (PR 1.55, 95 % CI 1.2–2.0) and work-related itchy skin (PR 1.97, 95 % CI 1.2–3.3). A possible exposure–response relationship for work-related itchy skin in bakery workers did not reach statistical significance. In both groups, reporting skin symptoms was strongly and significantly associated with reporting respiratory symptoms, both work-related and non-work-related. Conclusions Exposure–response relationships were observed for skin symptoms in auto body shop workers. The lack of significant exposure–response associations in bakery workers should be interpreted cautiously. Workers who reported skin symptoms were up to four times more likely to report respiratory symptoms. Improved awareness of both skin and respiratory outcomes in exposed workers is needed. Electronic supplementary material The online version of this article (doi:10.1007/s00420-012-0760-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Victoria Arrandale
- Centre for Research Expertise in Occupational Disease, University of Toronto, 223 College St, Toronto, ON M5T 1R4, Canada.
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Hamada H, Isaksson M, Bruze M, Engfeldt M, Liljelind I, Axelsson S, Jönsson B, Tinnerberg H, Zimerson E. Dermal uptake study with 4,4'-diphenylmethane diisocyanate led to active sensitization. Contact Dermatitis 2011; 66:101-5. [PMID: 22092061 DOI: 10.1111/j.1600-0536.2011.01995.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND To investigate the dermal uptake of 4,4'-diphenylmethane diisocyanate (4,4'-MDI), a study was performed in which 2 female volunteers were exposed to 10 and 25 mg, respectively, of 4,4'-MDI by applying 2.0% 4,4'-MDI in petrolatum over areas where the surface concentration corresponded to 800 µg/cm(2) . Ten days later, they developed eczematous dermatitis at the area of application. OBJECTIVES To investigate whether the dermal application caused active sensitization to 4,4'-MDI. METHODS Chemical analysis of the 4,4'-MDI preparation used in the application and the amount of 4,4'-MDI not absorbed by the skin was performed with liquid chromatography-mass spectrometry. The volunteers were tested with serial dilutions of 4,4'-MDI and the potentially cross-reacting substances 4,4'-diaminodiphenylmethane (4,4'-MDA), p-phenylenediamine (PPD), and dicyclohexylmethane-4,4'-diisocyanate (DMDI). RESULTS Patch test results suggested that the volunteers were actively sensitized to 4,4'-MDI following the dermal uptake study, as they reacted positively to 4,4'-MDA, a marker for 4,4'-MDI allergy. No positive reactions were seen to PPD or DMDI. Chemical investigation confirmed that the correct concentration had been used for the dermal uptake study, and showed that about 70% of the applied 4,4'-MDI was not absorbed. CONCLUSIONS A dermal uptake study with 4,4'-MDI in 2.0% pet. with an occlusion time of 8 hr induced active sensitization to 4,4'-MDI and subsequently to 4,4'-MDA.
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Affiliation(s)
- Haneen Hamada
- Department of Occupational and Enviromental Dermatology, Skåne University Hospital, Lund University, 205 02 Malmö, Sweden.
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Wisnewski AV, Xu L, Robinson E, Liu J, Redlich CA, Herrick CA. Immune sensitization to methylene diphenyl diisocyanate (MDI) resulting from skin exposure: albumin as a carrier protein connecting skin exposure to subsequent respiratory responses. J Occup Med Toxicol 2011; 6:6. [PMID: 21414210 PMCID: PMC3068988 DOI: 10.1186/1745-6673-6-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 03/17/2011] [Indexed: 11/10/2022] Open
Abstract
Background Methylene diphenyl diisocyanate (MDI), a reactive chemical used for commercial polyurethane production, is a well-recognized cause of occupational asthma. The major focus of disease prevention efforts to date has been respiratory tract exposure; however, skin exposure may also be an important route for inducing immune sensitization, which may promote subsequent airway inflammatory responses. We developed a murine model to investigate pathogenic mechanisms by which MDI skin exposure might promote subsequent immune responses, including respiratory tract inflammation. Methods Mice exposed via the skin to varying doses (0.1-10% w/v) of MDI diluted in acetone/olive oil were subsequently evaluated for MDI immune sensitization. Serum levels of MDI-specific IgG and IgE were measured by enzyme-linked immunosorbant assay (ELISA), while respiratory tract inflammation, induced by intranasal delivery of MDI-mouse albumin conjugates, was evaluated based on bronchoalveolar lavage (BAL). Autologous serum IgG from "skin only" exposed mice was used to detect and guide the purification/identification of skin proteins antigenically modified by MDI exposure in vivo. Results Skin exposure to MDI resulted in specific antibody production and promoted subsequent respiratory tract inflammation in animals challenged intranasally with MDI-mouse albumin conjugates. The degree of (secondary) respiratory tract inflammation and eosinophilia depended upon the (primary) skin exposure dose, and was maximal in mice exposed to 1% MDI, but paradoxically limited in mice receiving 10-fold higher doses (e.g. 10% MDI). The major antigenically-modified protein at the local MDI skin exposure site was identified as albumin, and demonstrated biophysical changes consistent with MDI conjugation. Conclusions MDI skin exposure can induce MDI-specific immune sensitivity and promote subsequent respiratory tract inflammatory responses and thus, may play an important role in MDI asthma pathogenesis. MDI conjugation and antigenic modification of albumin at local (skin/respiratory tract) exposure sites may represent the common antigenic link connecting skin exposure to subsequent respiratory tract inflammation.
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Affiliation(s)
- Adam V Wisnewski
- Department of Internal Medicine; Yale University School of Medicine; 300 Cedar Street; New Haven, CT; 06510, USA.
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15
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Abstract
Isocyanates are reactive chemicals and thousands of workers may be exposed to them during their manufacture and use in a wide range of products. They are classed as sensitizers and are a major cause of occupational asthma in the UK. Workplace exposure limits are low and control of exposure often depends on personal respiratory protection. Biological monitoring is increasingly used to assess exposure and the efficacy of control measures, including the behavioural aspects of controls. Biological monitoring methods are available for the most common isocyanates hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, and methylenediphenyl diisocyanate. They are based on the analysis of hexamethylene diamine, toluene diamine, isopherone diamine, and methylenediamine released after hydrolysis of isocyanate-protein adducts in urine or blood. Volunteer and occupational studies show good correlations between inhalation exposure to isocyanate monomers and isocyanate-derived diamines in urine or blood. However, occupational exposure to isocyanates is often to a mixture of monomers and oligomers so there is some uncertainty comparing biological monitoring results with airborne exposure to 'total NCO'. Nevertheless, there is a substantial body of work demonstrating the utility of biological monitoring as a tool to assess exposure and the efficacy of controls, including how they are used in practice. Non-health-based biological monitoring guidance values are available to help target when and where further action is required. Occupational hygienists will need to use their knowledge and experience to determine the relative contributions of different routes of exposure and how controls can be improved to reduced the risk of ill health.
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Affiliation(s)
- John Cocker
- Health and Safety Laboratory, Harpur Hill Buxton S10 3PT, UK.
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16
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Kammer R, Tinnerberg H, Eriksson K. Evaluation of a tape-stripping technique for measuring dermal exposure to pyrene and benzo(a)pyrene. ACTA ACUST UNITED AC 2011; 13:2165-71. [DOI: 10.1039/c1em10245a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Sabbioni G, Dongari N, Kumar A. Determination of a new biomarker in subjects exposed to 4,4'-methylenediphenyl diisocyanate. Biomarkers 2010; 15:508-15. [PMID: 20553091 DOI: 10.3109/1354750x.2010.490880] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
4,4'-Methylenediphenyl diisocyanate (MDI) is the most important of the isocyanates used as intermediates in the chemical industry. Among the main types of damage after exposure to low levels of MDI are lung sensitization and asthma. Albumin adducts of MDI might be involved in the etiology of sensitization reactions. This work presents a liquid chromatography (LC)-mass spectrometry (MS/MS) procedure for determination of isocyanate-specific albumin adducts in humans. MDI formed adducts with lysine of albumin: MDI-Lys and AcMDI-Lys. The MDI-Lys levels, 25th, 50th, 75th, 90th percentile, were 0, 65.2, 134, 244 fmol mg(-1) and 0, 30.5, 57.4, 95.8 fmol mg(-1) in the exposed construction and factory workers, respectively. This new biomonitoring procedure will allow assessment of suspected exposure sources and may contribute to the identification of individuals who are particularly vulnerable for developing bronchial asthma and other respiratory diseases after exposure to isocyanates.
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Affiliation(s)
- Gabriele Sabbioni
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, USA.
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18
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Abstract
Numerous occupational and environmental exposures that increase asthma risk have been identified. Research and prevention have focused primarily on the respiratory tract. However, recent studies suggest that the skin may also be an important route of exposure and site of sensitization that contributes to asthma development. Factors that impair skin barrier function, such as filaggrin gene mutations or skin trauma, may facilitate allergen entry and promote Th2-like sensitization and subsequent asthma. Animal studies demonstrate that skin exposure to chemical and protein allergens is highly effective at inducing sensitization, with subsequent inhalation challenge eliciting asthmatic responses. A similar role for human skin exposure to certain sensitizing agents, such as isocyanates, is likely. Skin exposure methodologies are being developed to incorporate skin exposure assessment into epidemiology studies investigating asthma risk factors.
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