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House EL, Kim SY, Chalupa D, Hernady E, Groves AM, Johnston CJ, McGraw MD. IL-17A neutralization fails to attenuate airway remodeling and potentiates a proinflammatory lung microenvironment in diacetyl-exposed rats. Am J Physiol Lung Cell Mol Physiol 2023; 325:L434-L446. [PMID: 37642674 PMCID: PMC10639012 DOI: 10.1152/ajplung.00082.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023] Open
Abstract
Bronchiolitis obliterans (BO) is a devastating lung disease that can develop following inhalation exposure to certain chemicals. Diacetyl (DA) is one chemical commonly associated with BO development when inhaled at occupational levels. Previous studies in rats have shown that repetitive DA vapor exposures increased lung CD4+CD25+ T cells and bronchoalveolar (BAL) interleukin-17A (IL-17A) concentrations concurrent with the development of airway remodeling. We hypothesized that IL-17A neutralization would attenuate the severity of airway remodeling after repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor or filtered air (RA) for 6 h/day × 5 days and monitored for 2 wk postexposure. Treatment with IL-17A neutralization (αIL-17A) or IgG (control) began immediately following exposures and continued twice weekly until study's end. Lungs were harvested for histology, flow cytometry, and BAL analyses. Survival, oxygen saturations, and percent weight change decreased significantly in DA-exposed versus RA-exposed rats, but did not differ significantly between DA + αIL-17A versus DA + IgG. Similarly, the number nor severity of airway lesions did not differ significantly between DA + αIL-17A versus DA + IgG rats despite the percentage of lung regulatory T cells increasing with decreased BAL IL-17A concentrations. Ashcroft scoring of the distal lung parenchyma suggested worse parenchymal remodeling in DA + αIL-17A versus DA + IgG rats with increased expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and nuclear factor-kappa B (NF-κB). Collectively, IL-17A neutralization in DA-exposed rats failed to attenuate airway remodeling with increased expression of pro-inflammatory cytokines TNF-α, IL-1β, and NF-κB.NEW & NOTEWORTHY Interleukin-17A (IL-17A) neutralization has shown benefit previously in preclinical models of transplant-associated bronchiolitis obliterans (BO), yet it remains unknown whether IL-17A neutralization has similar benefit for other forms of BO. Here, IL-17A neutralization fails to prevent severe airway remodeling in rats exposed repetitively to the flavoring chemical diacetyl, and instead, promotes a proinflammatory microenvironment with increased expression of TNF-α, IL-1β, and NF-κB within the lung.
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Affiliation(s)
- Emma L House
- Department of Pathology, University of Rochester Medical Center, Rochester, New York, United States
- Department of Pediatrics, Division of Pediatric Pulmonology, University of Rochester Medical Center, Rochester, New York, United States
| | - So-Young Kim
- Department of Pediatrics, Division of Pediatric Pulmonology, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - David Chalupa
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - Eric Hernady
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York, United States
| | - Angela M Groves
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York, United States
- Department of Pediatrics, Division of Neonatology, University of Rochester Medical Center, Rochester, New York, United States
| | - Carl J Johnston
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York, United States
- Department of Pediatrics, Division of Neonatology, University of Rochester Medical Center, Rochester, New York, United States
| | - Matthew D McGraw
- Department of Pediatrics, Division of Pediatric Pulmonology, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
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2
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Nunes NMF, do Nascimento Silva J, Conceição MLP, da Costa Júnior JS, da Silva Sousa E, das Dores Alves de Oliveira M, Maria das Graças Lopes Citó A, Dittz D, Peron AP, Ferreira PMP. In vitro and in vivo acute toxicity of an artificial butter flavoring. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2023; 86:181-197. [PMID: 36794368 DOI: 10.1080/15287394.2023.2172502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Flavorings used in cookies, electronic cigarettes, popcorn, and breads contain approximately 30 chemical compounds, which makes it difficult to determine and correlate signs and symptoms of acute, subacute or chronic toxicity. The aim of this study was to characterize a butter flavoring chemically and subsequently examine the in vitro and in vivo toxicological profile using cellular techniques, invertebrates, and lab mammals. For the first time, the ethyl butanoate was found as the main compound of a butter flavoring (97.75%) and 24 h-toxicity assay employing Artemia salina larvae revealed a linear effect and LC50 value of 14.7 (13.7-15.7) mg/ml (R2 = 0.9448). Previous reports about higher oral doses of ethyl butanoate were not found. Observational screening with doses between 150-1000 mg/kg by gavage displayed increased amount of defecation, palpebral ptosis, and grip strength reduction, predominantly at higher doses. The flavoring also produced clinical signs of toxicity and diazepam-like behavioral changes in mice, including loss of motor coordination, muscle relaxation, increase of locomotor activity and intestinal motility, and induction of diarrhea, with deaths occurring after 48 h exposure. This substance fits into category 3 of the Globally Harmonized System. Data demonstrated that butter flavoring altered the emotional state in Swiss mice and disrupted intestinal motility, which may be a result of neurochemical changes or direct lesions in the central/peripheral nervous systems.
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Affiliation(s)
- Nárcia Mariana Fonseca Nunes
- Department of Biophysics and Physiology, Laboratory of Experimental Cancerology (LabCancer), Federal University of Piauí, Teresina, Brazil
| | - Jurandy do Nascimento Silva
- Department of Biophysics and Physiology, Laboratory of Experimental Cancerology (LabCancer), Federal University of Piauí, Teresina, Brazil
- Department of Chemistry, Federal Institute of Education and Technology of Piauí, Teresina, Brazil
| | - Micaely Lorrana Pereira Conceição
- Department of Biophysics and Physiology, Laboratory of Experimental Cancerology (LabCancer), Federal University of Piauí, Teresina, Brazil
| | | | | | | | | | - Dalton Dittz
- Department of Biochemistry and Pharmacology, Federal University of Piauí, Teresina, Brazil
| | - Ana Paula Peron
- Department of Biochemistry and Pharmacology, Federal University of Piauí, Teresina, Brazil
- Department of Biodiversity and Nature Conservation, Federal Technological University of Paraná, Campo Mourão, Brazil
| | - Paulo Michel Pinheiro Ferreira
- Department of Biophysics and Physiology, Laboratory of Experimental Cancerology (LabCancer), Federal University of Piauí, Teresina, Brazil
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Alhadyan SK, Sivaraman V, Onyenwoke RU. E-cigarette Flavors, Sensory Perception, and Evoked Responses. Chem Res Toxicol 2022; 35:2194-2209. [PMID: 36480683 DOI: 10.1021/acs.chemrestox.2c00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.
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Affiliation(s)
- Shatha K Alhadyan
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Vijay Sivaraman
- Department of Biological and Biomedical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States
| | - Rob U Onyenwoke
- Department of Pharmaceutical Sciences, North Carolina Central University, Durham, North Carolina 27707, United States.,Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, North Carolina 27707, United States
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4
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Card JW, Scaife KM, Haighton LA. Review of evidence relating to occupational exposure limits for alpha-diketones and acetoin, and considerations for deriving an occupational exposure limit for 2,3-pentanedione. Crit Rev Toxicol 2022; 52:715-730. [PMID: 36803409 DOI: 10.1080/10408444.2023.2168175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Alpha-diketones, notably diacetyl, have been used as flavoring agents. When airborne in occupational settings, exposures to diacetyl have been associated with serious respiratory disease. Other α-diketones, such as 2,3-pentanedione, and analogues such as acetoin (a reduced form of diacetyl), require evaluation, particularly, in light of recently available toxicological studies. The current work reviewed mechanistic, metabolic, and toxicology data available for α-diketones. Data were most available for diacetyl and 2,3-pentanedione, and a comparative assessment of their pulmonary effects was performed, and an occupational exposure limit (OEL) was proposed for 2,3-pentanedione. Previous OELs were reviewed and an updated literature search was performed. Respiratory system histopathology data from 3-month toxicology studies were evaluated with benchmark dose (BMD) modelling of sensitive endpoints. This demonstrated comparable responses at concentrations up to 100 ppm, with no consistent overall pattern of greater sensitivity to either diacetyl or 2,3-pentanedione. In contrast, based on draft raw data, no adverse respiratory effects were observed in comparable 3-month toxicology studies that evaluated exposure to acetoin at up to 800 ppm (highest tested concentration), indicating that acetoin does not present the same inhalation hazard as diacetyl or 2,3-pentanedione. To derive an OEL for 2,3-pentanedione, BMD modelling was conducted for the most sensitive endpoint from 90-day inhalation toxicity studies, namely, hyperplasia of nasal respiratory epithelium. On the basis of this modelling, an 8-hour time-weighted average OEL of 0.07 ppm is proposed to be protective against respiratory effects that may be associated with chronic workplace exposure to 2,3-pentanedione.
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Affiliation(s)
- Jeffrey W Card
- Intertek Health Sciences Inc., Mississauga, Ontario, Canada
| | - Kevin M Scaife
- Intertek Health Sciences Inc., Mississauga, Ontario, Canada
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5
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Pipe AL, Mir H. E-Cigarettes Reexamined: Product Toxicity. Can J Cardiol 2022; 38:1395-1405. [PMID: 36089290 DOI: 10.1016/j.cjca.2022.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 08/03/2022] [Accepted: 08/03/2022] [Indexed: 12/24/2022] Open
Abstract
The introduction of e-cigarettes, or electronic nicotine delivery systems (ENDS), has been accompanied by controversy regarding their safety and effectiveness as a cessation aid and by an explosion in their use by youth. Their use does not involve the combustion of tobacco and the creation of harmful combustion products; they have been seen as a "harm reduction" tool that may be of assistance in promoting smoking cessation. Recognition that ENDS can deliver an array of chemicals and materials with known adverse consequences has spurred more careful examination of these products. Nicotine, nitrosamines, carbonyl compounds, heavy metals, free radicals, reactive oxygen species, particulate matter, and "emerging chemicals of concern" are among the constituents of the heated chemical aerosol that is inhaled when ENDS are used. They raise concerns for cardiovascular and respiratory health that merit the attention of clinicians and regulatory agencies. Frequently cited concerns include evidence of disordered respiratory function, altered hemodynamics, endothelial dysfunction, vascular reactivity, and enhanced thrombogenesis. The absence of evidence of the consequences of their long-term use is of additional concern. Their effectiveness as cessation aids and beneficial impact on health outcomes continue to be examined. It is important to ensure that their production and availability are thoughtfully regulated to optimise their safety and permit their use as harm reduction devices and potentially as smoking-cessation aids. It is equally vital to effectively prevent them from becoming ubiquitous consumer products with the potential to rapidly induce nicotine addiction among large numbers of youth. Clinicians should understand the nature of these products and the implications of their use.
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Affiliation(s)
- Andrew L Pipe
- Division of Cardiac Prevention and Rehabilitation, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Hassan Mir
- Division of Cardiac Prevention and Rehabilitation, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
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6
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Virji MA, Fechter-Leggett ED, Groth CP, Liang X, Blackley BH, Stanton ML, LeBouf RF, Harvey RR, Bailey RL, Cummings KJ, Cox-Ganser JM. Decrements in lung function and respiratory abnormalities associated with exposure to diacetyl and 2,3-pentanedione in coffee production workers. Front Public Health 2022; 10:966374. [PMID: 36033819 PMCID: PMC9412051 DOI: 10.3389/fpubh.2022.966374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/18/2022] [Indexed: 01/24/2023] Open
Abstract
Coffee production workers are exposed to complex mixtures of gases, dust, and vapors, including the known respiratory toxins, diacetyl, and 2,3-pentanedione, which occur naturally during coffee roasting and are also present in flavorings used to flavor coffee. This study evaluated the associations of these two α-diketones with lung function measures in coffee production workers. Workers completed questionnaires, and their lung function was assessed by spirometry and impulse oscillometry (IOS). Personal exposures to diacetyl, 2,3-pentanedione, and their sum (SumDA+PD) were assigned to participants, and metrics of the highest 95th percentile (P95), cumulative, and average exposure were calculated. Linear and logistic regression models for continuous and binary/polytomous outcomes, respectively, were used to explore exposure-response relationships adjusting for age, body mass index, tenure, height, sex, smoking status, race, or allergic status. Decrements in percent predicted forced expiratory volume in 1 second (ppFEV1) and forced vital capacity (ppFVC) were associated with the highest-P95 exposures to 2,3-pentanedione and SumDA+PD. Among flavoring workers, larger decrements in ppFEV1 and ppFVC were associated with highest-P95 exposures to diacetyl, 2,3-pentanedione, and SumDA+PD. Abnormal FEV1, FVC, and restrictive spirometric patterns were associated with the highest-P95, cumulative, and average exposures for all α-diketone metrics; some of these associations were also present among flavoring and non-flavoring workers. The combined category of small and peripheral airways plus small and large airways abnormalities on IOS had elevated odds for highest-P95 exposure to α-diketones. These results may be affected by the small sample size, few cases of abnormal spirometry, and the healthy worker effect. Associations between lung function abnormalities and exposure to α-diketones suggest it may be prudent to consider exposure controls in both flavoring and non-flavoring settings.
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Affiliation(s)
- Mohammed Abbas Virji
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States,*Correspondence: Mohammed Abbas Virji
| | - Ethan D. Fechter-Leggett
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Caroline P. Groth
- Department of Epidemiology and Biostatistics, West Virginia University School of Public Health, Morgantown, WV, United States
| | - Xiaoming Liang
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Brie H. Blackley
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Marcia L. Stanton
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Ryan F. LeBouf
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - R. Reid Harvey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Rachel L. Bailey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Kristin J. Cummings
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
| | - Jean M. Cox-Ganser
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
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7
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Langel SN, Kelly FL, Brass DM, Nagler AE, Carmack D, Tu JJ, Travieso T, Goswami R, Permar SR, Blasi M, Palmer SM. E-cigarette and food flavoring diacetyl alters airway cell morphology, inflammatory and antiviral response, and susceptibility to SARS-CoV-2. Cell Death Dis 2022; 8:64. [PMID: 35169120 PMCID: PMC8847558 DOI: 10.1038/s41420-022-00855-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/18/2022] [Accepted: 01/27/2022] [Indexed: 11/09/2022]
Abstract
Diacetyl (DA) is an α-diketone that is used to flavor microwave popcorn, coffee, and e-cigarettes. Occupational exposure to high levels of DA causes impaired lung function and obstructive airway disease. Additionally, lower levels of DA exposure dampen host defenses in vitro. Understanding DA’s impact on lung epithelium is important for delineating exposure risk on lung health. In this study, we assessed the impact of DA on normal human bronchial epithelial cell (NHBEC) morphology, transcriptional profiles, and susceptibility to SARS-CoV-2 infection. Transcriptomic analysis demonstrated cilia dysregulation, an increase in hypoxia and sterile inflammation associated pathways, and decreased expression of interferon-stimulated genes after DA exposure. Additionally, DA exposure resulted in cilia loss and increased hyaluronan production. After SARS-CoV-2 infection, both genomic and subgenomic SARS-CoV-2 RNA were increased in DA vapor- compared to vehicle-exposed NHBECs. This work suggests that transcriptomic and physiologic changes induced by DA vapor exposure damage cilia and increase host susceptibility to SARS-CoV-2.
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Affiliation(s)
- Stephanie N Langel
- Duke Center for Human Systems Immunology and Department of Surgery, Durham, NC, USA
| | - Francine L Kelly
- Duke Clinical Research Institute and Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - David M Brass
- Duke Clinical Research Institute and Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Andrew E Nagler
- Duke Clinical Research Institute and Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Dylan Carmack
- Duke Clinical Research Institute and Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Joshua J Tu
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA.,Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Tatianna Travieso
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA.,Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USA
| | - Ria Goswami
- Department of Pediatrics, Weill Cornell Medicine, New York, NY, USA
| | - Sallie R Permar
- Department of Pediatrics, Weill Cornell Medicine, New York, NY, USA
| | - Maria Blasi
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC, USA. .,Department of Medicine, Division of Infectious Diseases, Duke University Medical Center, Durham, NC, USA.
| | - Scott M Palmer
- Duke Clinical Research Institute and Department of Medicine, Duke University Medical Center, Durham, NC, USA
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House EL, Kim SY, Johnston CJ, Groves AM, Hernady E, Misra RS, McGraw MD. Diacetyl Vapor Inhalation Induces Mixed, Granulocytic Lung Inflammation with Increased CD4 +CD25 + T Cells in the Rat. TOXICS 2021; 9:359. [PMID: 34941793 PMCID: PMC8707442 DOI: 10.3390/toxics9120359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022]
Abstract
Diacetyl (DA) is a highly reactive alpha diketone associated with flavoring-related lung disease. In rodents, acute DA vapor exposure can initiate an airway-centric, inflammatory response. However, this immune response has yet to be fully characterized in the context of flavoring-related lung disease progression. The following studies were designed to characterize the different T cell populations within the lung following repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor for 5 consecutive days × 6 h/day. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for changes in histology by H&E and Trichrome stain, T cell markers by flow cytometry, total BALF cell counts and differentials, BALF IL17a and total protein immediately, 1 and 2 weeks post-exposure. Lung histology and BALF cell composition demonstrated mixed, granulocytic lung inflammation with bronchial lymphoid aggregates at all time points in DA-exposed lungs compared to air controls. While no significant change was seen in percent lung CD3+, CD4+, or CD8+ T cells, a significant increase in lung CD4+CD25+ T cells developed at 1 week that persisted at 2 weeks post-exposure. Further characterization of this CD4+CD25+ T cell population identified Foxp3+ T cells at 1 week that failed to persist at 2 weeks. Conversely, BALF IL-17a increased significantly at 2 weeks in DA-exposed rats compared to air controls. Lung CD4+CD25+ T cells and BALF IL17a correlated directly with BALF total protein and inversely with rat oxygen saturations. Repetitive DA vapor exposure at occupationally relevant concentrations induced mixed, granulocytic lung inflammation with increased CD4+CD25+ T cells in the rat lung.
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Affiliation(s)
- Emma L. House
- Department of Pathology, University of Rochester Medical Center, Rochester, NY 14642, USA;
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
| | - So-Young Kim
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
| | - Carl J. Johnston
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Angela M. Groves
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Eric Hernady
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ravi S. Misra
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Matthew D. McGraw
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
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9
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Ghio AJ, Soukup JM, Dailey LA, Roggli VL, Crumbliss AL, Palmer SM. Diacetyl exposure disrupts iron homeostasis in animals and cells. Inhal Toxicol 2021; 33:268-274. [PMID: 34752160 DOI: 10.1080/08958378.2021.1989092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Several mechanisms have been proposed for the biological effect of diacetyl. We tested the postulate that animal and cell exposures to diacetyl are associated with a disruption in iron homeostasis. MATERIALS AND METHODS Male, Sprague-Dawley rats were intratracheally-instilled with either distilled water or diacetyl. Seven days after treatment, animals were euthanized and the lungs removed, fixed, and embedded. Sections were cut and stained for iron, collagen, and ferritin. Human epithelial (BEAS-2B) and monocytic (THP-1) cells were exposed in vitro to ferric ammonium citrate (FAC), diacetyl, and both FAC and diacetyl. Cell non-heme iron concentrations and ferritin levels were quantified using inductively coupled plasma optical emission spectroscopy and an immunoassay respectively. RESULTS After exposure of animals to diacetyl, there were airway polypoid lesions which stained positively for both iron and the intracellular storage protein ferritin. Trichrome stain showed a deposition of collagen immediately adjacent to accumulated metal following diacetyl exposure. In in vitro cell exposures, FAC increased non-heme iron concentration but co-incubations of FAC and diacetyl elevated levels to significantly greater values. Levels of ferritin were increased with exposures of BEAS-2B and THP-1 cells to FAC but were similarly greater after co-exposure with FAC and diacetyl. CONCLUSIONS Results of animal and cell studies support a disruption of iron homeostasis by diacetyl. It is proposed that, following internalization, diacetyl complexes intracellular sources of iron. The cell recognizes a loss of its requisite iron to diacetyl and imports greater concentrations of the metal.
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Affiliation(s)
- Andrew J Ghio
- US Environmental Protection Agency, Chapel Hill, NC, USA
| | | | - Lisa A Dailey
- US Environmental Protection Agency, Chapel Hill, NC, USA
| | - Victor L Roggli
- Department of Pathology, Duke University Medical Center, Durham, NC, USA
| | | | - Scott M Palmer
- Deparment of Medicine, Duke University Medical Center, Durham, NC, USA
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10
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Wang J, Kim SY, House E, Olson HM, Johnston CJ, Chalupa D, Hernady E, Mariani TJ, Clair G, Ansong C, Qian WJ, Finkelstein JN, McGraw MD. Repetitive diacetyl vapor exposure promotes ubiquitin proteasome stress and precedes bronchiolitis obliterans pathology. Arch Toxicol 2021; 95:2469-2483. [PMID: 34031698 DOI: 10.1007/s00204-021-03076-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/06/2021] [Indexed: 12/01/2022]
Abstract
Bronchiolitis obliterans (BO) is a devastating lung disease seen commonly after lung transplant, following severe respiratory tract infection or chemical inhalation exposure. Diacetyl (DA; 2,3-butanedione) is a highly reactive alpha-diketone known to cause BO when inhaled, however, the mechanisms of how inhalation exposure leads to BO development remains poorly understood. In the current work, we combined two clinically relevant models for studying the pathogenesis of DA-induced BO: (1) an in vivo rat model of repetitive DA vapor exposures with recovery and (2) an in vitro model of primary human airway epithelial cells exposed to pure DA vapors. Rats exposed to 5 consecutive days 200 parts-per-million DA 6 h per day had worsening survival, persistent hypoxemia, poor weight gain, and histologic evidence of BO 14 days after DA exposure cessation. At the end of exposure, increased expression of the ubiquitin stress protein ubiquitin-C accumulated within DA-exposed rat lung homogenates and localized primarily to the airway epithelium, the primary site of BO development. Lung proteasome activity increased concurrently with ubiquitin-C expression after DA exposure, supportive of significant proteasome stress. In primary human airway cultures, global proteomics identified 519 significantly modified proteins in DA-exposed samples relative to controls with common pathways of the ubiquitin proteasome system, endosomal reticulum transport, and response to unfolded protein pathways being upregulated and cell-cell adhesion and oxidation-reduction pathways being downregulated. Collectively, these two models suggest that diacetyl inhalation exposure causes abundant protein damage and subsequent ubiquitin proteasome stress prior to the development of chemical-induced BO pathology.
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Affiliation(s)
- Juan Wang
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - So-Young Kim
- Division of Pulmonology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 667, Rochester, NY, 14642, USA
| | - Emma House
- Division of Pulmonology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 667, Rochester, NY, 14642, USA.,Department of Pathology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Heather M Olson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Carl J Johnston
- Division of Pulmonology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 667, Rochester, NY, 14642, USA.,Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - David Chalupa
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Eric Hernady
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Thomas J Mariani
- Division of Neonatology, Department of Pediatric Pulmonology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Gérémy Clair
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Charles Ansong
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Jacob N Finkelstein
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.,Division of Neonatology, Department of Pediatric Pulmonology, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Matthew D McGraw
- Division of Pulmonology, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 667, Rochester, NY, 14642, USA. .,Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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11
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Harvey RR, Blackley BH, Korbach EJ, Rawal AX, Roggli VL, Bailey RL, Cox-Ganser JM, Cummings KJ. Case Report: Flavoring-Related Lung Disease in a Coffee Roasting and Packaging Facility Worker With Unique Lung Histopathology Compared With Previously Described Cases of Obliterative Bronchiolitis. Front Public Health 2021; 9:657987. [PMID: 34095061 PMCID: PMC8173047 DOI: 10.3389/fpubh.2021.657987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/14/2021] [Indexed: 11/13/2022] Open
Abstract
Occupational exposure to diacetyl, a butter flavor chemical, can result in obliterative bronchiolitis. Obliterative bronchiolitis is characterized by exertional dyspnea, fixed airflow obstruction, and histopathologic constrictive bronchiolitis, with bronchiolar wall fibrosis leading to luminal narrowing and obliteration. We describe a case of advanced lung disease with histopathology distinct from obliterative bronchiolitis in a 37-year-old male coffee worker following prolonged exposure to high levels of diacetyl and the related compound 2,3-pentanedione, who had no other medical, avocational, or occupational history that could account for his illness. He began working at a coffee facility in the flavoring room and grinding area in 2009. Four years later he moved to the packaging area but continued to flavor and grind coffee at least 1 full day per week. He reported chest tightness and mucous membrane irritation when working in the flavoring room and grinding area in 2010. Beginning in 2014, he developed dyspnea, intermittent cough, and a reduced sense of smell without a work-related pattern. In 2016, spirometry revealed a moderate mixed pattern that did not improve with bronchodilator. Thoracoscopic lung biopsy results demonstrated focal mild cellular bronchiolitis and pleuritis, and focal peribronchiolar giant cells/granulomas, but no evidence of constrictive bronchiolitis. Full-shift personal air-samples collected in the flavoring and grinding areas during 2016 measured diacetyl concentrations up to 84-fold higher than the recommended exposure limit. Medical evaluations indicate this worker developed work-related, airway-centric lung disease, most likely attributable to inhalational exposure to flavorings, with biopsy findings not usual for obliterative bronchiolitis. Clinicians should be aware that lung pathology could vary considerably in workers with suspected flavoring-related lung disease.
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Affiliation(s)
- R Reid Harvey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Brie H Blackley
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | | | | | - Victor L Roggli
- Department of Pathology, Duke University, Durham, NC, United States
| | - Rachel L Bailey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Jean M Cox-Ganser
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Kristin J Cummings
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
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12
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Abstract
Occupational bronchiolitis is characterized by inflammation of the small airways, and represents a heterogeneous set of lung conditions that can occur following a range of inhalation exposures related to work. The most common clinical presentation includes insidious onset of exertional dyspnea and cough. Multiple reports in recent years have drawn attention to previously unrecognized risk factors for occupational bronchiolitis following exposures in several settings. Both current and past occupational exposures, including prior military deployment-related exposures, should be considered in patients undergoing evaluation for unexplained dyspnea. Diagnostic testing for potential bronchiolitis should include a thorough assessment of the small airways.
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13
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LeBouf RF, Blackley BH, Fortner AR, Stanton M, Martin SB, Groth CP, McClelland TL, Duling MG, Burns DA, Ranpara A, Edwards N, Fedan KB, Bailey RL, Cummings KJ, Nett RJ, Cox-Ganser JM, Virji MA. Exposures and Emissions in Coffee Roasting Facilities and Cafés: Diacetyl, 2,3-Pentanedione, and Other Volatile Organic Compounds. Front Public Health 2020; 8:561740. [PMID: 33072698 PMCID: PMC7531227 DOI: 10.3389/fpubh.2020.561740] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/13/2020] [Indexed: 11/13/2022] Open
Abstract
Roasted coffee and many coffee flavorings emit volatile organic compounds (VOCs) including diacetyl and 2,3-pentanedione. Exposures to VOCs during roasting, packaging, grinding, and flavoring coffee can negatively impact the respiratory health of workers. Inhalational exposures to diacetyl and 2,3-pentanedione can cause obliterative bronchiolitis. This study summarizes exposures to and emissions of VOCs in 17 coffee roasting and packaging facilities that included 10 cafés. We collected 415 personal and 760 area full-shift, and 606 personal task-based air samples for diacetyl, 2,3-pentanedione, 2,3-hexanedione, and acetoin using silica gel tubes. We also collected 296 instantaneous activity and 312 instantaneous source air measurements for 18 VOCs using evacuated canisters. The highest personal full-shift exposure in part per billion (ppb) to diacetyl [geometric mean (GM) 21 ppb; 95th percentile (P95) 79 ppb] and 2,3-pentanedione (GM 15 ppb; P95 52 ppb) were measured for production workers in flavored coffee production areas. These workers also had the highest percentage of measurements above the NIOSH Recommended Exposure Limit (REL) for diacetyl (95%) and 2,3-pentanedione (77%). Personal exposures to diacetyl (GM 0.9 ppb; P95 6.0 ppb) and 2,3-pentanedione (GM 0.7 ppb; P95 4.4 ppb) were the lowest for non-production workers of facilities that did not flavor coffee. Job groups with the highest personal full-shift exposures to diacetyl and 2,3-pentanedione were flavoring workers (GM 34 and 38 ppb), packaging workers (GM 27 and 19 ppb) and grinder operator (GM 26 and 22 ppb), respectively, in flavored coffee facilities, and packaging workers (GM 8.0 and 4.4 ppb) and production workers (GM 6.3 and 4.6 ppb) in non-flavored coffee facilities. Baristas in cafés had mean full-shift exposures below the RELs (GM 4.1 ppb diacetyl; GM 4.6 ppb 2,3-pentanedione). The tasks, activities, and sources associated with flavoring in flavored coffee facilities and grinding in non-flavored coffee facilities, had some of the highest GM and P95 estimates for both diacetyl and 2,3-pentanedione. Controlling emissions at grinding machines and flavoring areas and isolating higher exposure areas (e.g., flavoring, grinding, and packaging areas) from the main production space and from administrative or non-production spaces is essential for maintaining exposure control.
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Affiliation(s)
- Ryan F LeBouf
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Brie Hawley Blackley
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Alyson R Fortner
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Marcia Stanton
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Stephen B Martin
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Caroline P Groth
- Department of Biostatistics, School of Public Health, West Virginia University, Morgantown, WV, United States
| | - Tia L McClelland
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Matthew G Duling
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Dru A Burns
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Anand Ranpara
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Nicole Edwards
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Kathleen B Fedan
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Rachel L Bailey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Kristin J Cummings
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States.,California Department of Public Health, Richmond, CA, United States
| | - Randall J Nett
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - Jean M Cox-Ganser
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
| | - M Abbas Virji
- Respiratory Health Division, National Institute for Occupational Safety and Health, Morgantown, WV, United States
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14
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Melvin MS, Avery KC, Ballentine RM, Flora JW, Gardner W, Karles GD, Pithawalla YB, Smith DC, Ehman KD, Wagner KA. Formation of Diacetyl and Other α-Dicarbonyl Compounds during the Generation of E-Vapor Product Aerosols. ACS OMEGA 2020; 5:17565-17575. [PMID: 32715241 PMCID: PMC7377230 DOI: 10.1021/acsomega.0c02018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/01/2020] [Indexed: 06/11/2023]
Abstract
Exposure to diacetyl (DA) has been linked to the respiratory condition bronchiolitis obliterans. Previous research has demonstrated that DA and other α-dicarbonyl compounds can be detected in both the e-liquids and aerosols of e-vapor products (EVPs). While some EVP manufacturers may add these compounds as flavor ingredients, the primary objective of this work was to determine the potential for the formation of α-dicarbonyl compounds during the generation of aerosols from EVPs where no DA or other α-dicarbonyl compounds are added to the e-liquid. A novel ultraperformance liquid chromatography-mass spectrometry-based analytical method for the determination of DA, acetyl propionyl, glyoxal, and methylglyoxal was developed and validated. Next, eight commercially available cig-a-like-type EVPs were evaluated for α-dicarbonyl formation. Increased levels of α-dicarbonyls were observed in the aerosols of all evaluated EVPs compared to their respective e-liquids. Mechanistic studies were conducted using a model microwave reaction system to identify key reaction precursors for DA generated from propylene glycol (PG) and carbon-13-labeled glycerin (GLY). These studies, along with the corresponding retrosynthetic analysis, resulted in the proposed formation pathway where hydroxyacetone is generated from PG and/or GLY. Hydroxyacetone then participates in an aldol condensation with formaldehyde where formaldehyde can also be generated from PG and/or GLY; the resultant product then dehydrates to form DA. This proposed pathway was further investigated through in situ synthetic organic experiments within the model microwave reaction system. This work establishes that DA is formed in the aerosol generation process of the EVPs tested though at levels below toxicological concern.
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Affiliation(s)
- Matt S. Melvin
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Karen C. Avery
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Regina M. Ballentine
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Jason W. Flora
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - William Gardner
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Georgios D. Karles
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Yezdi B. Pithawalla
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Donna C. Smith
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Kimberly D. Ehman
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
| | - Karl A. Wagner
- Center for Research and Technology, Altria Client Services LLC, 601 East Jackson Street, Richmond, Virginia 23219, United States
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15
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16
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Budzyńska E, Sielemann S, Puton J, Surminski AL. Analysis of e-liquids for electronic cigarettes using GC-IMS/MS with headspace sampling. Talanta 2020; 209:120594. [DOI: 10.1016/j.talanta.2019.120594] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 11/25/2022]
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17
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Harvey RR, Fechter-Leggett ED, Bailey RL, Edwards NT, Fedan KB, Virji MA, Nett RJ, Cox-Ganser JM, Cummings KJ. The Burden of Respiratory Abnormalities Among Workers at Coffee Roasting and Packaging Facilities. Front Public Health 2020; 8:5. [PMID: 32083049 PMCID: PMC7003510 DOI: 10.3389/fpubh.2020.00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/08/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction: Respiratory hazards in the coffee roasting and packaging industry can include asthmagens such as green coffee bean and other dust and alpha-diketones such as diacetyl and 2,3-pentanedione that can occur naturally from roasting coffee or artificially from addition of flavoring to coffee. We sought to describe the burden of respiratory abnormalities among workers at 17 coffee roasting and packaging facilities. Methods: We completed medical surveys at 17 coffee roasting and packaging facilities that included interviewer-administered questionnaires and pulmonary function testing. We summarized work-related symptoms, diagnoses, and spirometry testing results among all participants. We compared health outcomes between participants who worked near flavoring and who did not. Results: Participants most commonly reported nose and eye symptoms, and wheeze, with a work-related pattern for some. Symptoms and pulmonary function tests were consistent with work-related asthma in some participants. About 5% of workers had abnormal spirometry and most improved after bronchodilator. Health outcomes were similar between employees who worked near flavoring and who did not, except employees who worked near flavoring reported more chronic bronchitis and ever receiving a diagnosis of asthma than those who did not work near flavoring. Conclusion: The symptoms and patterns likely represent overlapping health effects of different respiratory hazards, including green coffee bean and other dust that can contribute to work-related asthma, and diacetyl and 2,3-pentanedione that can contribute to obliterative bronchiolitis. Healthcare providers and occupational health and safety practitioners should be aware that workers at coffee roasting and packaging facilities are potentially at risk for occupational lung diseases.
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Affiliation(s)
- R. Reid Harvey
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, United States
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18
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Landman ST, Dhaliwal I, Mackenzie CA, Martinu T, Steel A, Bosma KJ. Life-threatening bronchiolitis related to electronic cigarette use in a Canadian youth. CMAJ 2019; 191:E1321-E1331. [PMID: 31753841 PMCID: PMC6887563 DOI: 10.1503/cmaj.191402] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2019] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Although electronic cigarettes (e-cigarettes) were initially marketed as a potential smoking-cessation aid and a safer alternative to smoking, the long-term health effect of e-cigarette use ("vaping") is unknown. Vaping e-liquids expose the user to several potentially harmful chemicals, including diacetyl, a flavouring compound known to cause bronchiolitis obliterans with inhalational exposure ("popcorn worker's lung"). CASE DESCRIPTION We report the case of a 17-year-old male who presented with intractable cough, progressive dyspnea and malaise after vaping flavoured e-liquids and tetrahydrocannabinol intensively. Initial physical examination showed fever, tachycardia, hypoxemia, and bibasilar inspiratory crackles on lung auscultation. Computed tomography of the chest showed diffuse centrilobular "tree-inbud" nodularity, consistent with acute bronchiolitis. Multiple cultures, including from 2 bronchoalveolar lavage samples, and biopsy stains, were negative for infection. He required intubation, invasive mechanical ventilation and venovenous extracorporeal membrane oxygenation (ECMO) for refractory hypercapnia. The patient's condition improved with high-dose corticosteroids. He was weaned off ECMO and mechanical ventilation, and discharged home after 47 days in hospital. Several months after hospital discharge, his exercise tolerance remained limited and pulmonary function tests showed persistent, fixed airflow obstruction with gas trapping. The patient's clinical picture was suggestive of possible bronchiolitis obliterans, thought to be secondary to inhalation of flavouring agents in the e-liquids, although the exact mechanism of injury and causative agent are unknown. INTERPRETATION This case of severe acute bronchiolitis, causing near-fatal hypercapnic respiratory failure and chronic airflow obstruction in a previously healthy Canadian youth, may represent vaping-associated bronchiolitis obliterans. This novel pattern of pulmonary disease associated with vaping appears distinct from the type of alveolar injury predominantly reported in the recent outbreak of cases of vaping-associated pulmonary illness in the United States, underscoring the need for further research into all potentially toxic components of e-liquids and tighter regulation of e-cigarettes.
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Affiliation(s)
- Simon T Landman
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Inderdeep Dhaliwal
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Constance A Mackenzie
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Tereza Martinu
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Andrew Steel
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Karen J Bosma
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont.
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19
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Vas CA, Porter A, McAdam K. Acetoin is a precursor to diacetyl in e-cigarette liquids. Food Chem Toxicol 2019; 133:110727. [DOI: 10.1016/j.fct.2019.110727] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/27/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022]
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20
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Hubbs AF, Kreiss K, Cummings KJ, Fluharty KL, O'Connell R, Cole A, Dodd TM, Clingerman SM, Flesher JR, Lee R, Pagel S, Battelli LA, Cumpston A, Jackson M, Kashon M, Orandle MS, Fedan JS, Sriram K. Flavorings-Related Lung Disease: A Brief Review and New Mechanistic Data. Toxicol Pathol 2019; 47:1012-1026. [PMID: 31645208 DOI: 10.1177/0192623319879906] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Flavorings-related lung disease is a potentially disabling and sometimes fatal lung disease of workers making or using flavorings. First identified almost 20 years ago in microwave popcorn workers exposed to butter-flavoring vapors, flavorings-related lung disease remains a concern today. In some cases, workers develop bronchiolitis obliterans, a severe form of fixed airways disease. Affected workers have been reported in microwave popcorn, flavorings, and coffee production workplaces. Volatile α-dicarbonyl compounds, particularly diacetyl (2,3-butanedione) and 2,3-pentanedione, are implicated in the etiology. Published studies on diacetyl and 2,3-pentanedione document their ability to cause airway epithelial necrosis, damage biological molecules, and perturb protein homeostasis. With chronic exposure in rats, they produce airway fibrosis resembling bronchiolitis obliterans. To add to this knowledge, we recently evaluated airway toxicity of the 3-carbon α-dicarbonyl compound, methylglyoxal. Methylglyoxal inhalation causes epithelial necrosis at even lower concentrations than diacetyl. In addition, we investigated airway toxicity of mixtures of diacetyl, acetoin, and acetic acid, common volatiles in butter flavoring. At ratios comparable to workplace scenarios, the mixtures or diacetyl alone, but not acetic acid or acetoin, cause airway epithelial necrosis. These new findings add to existing data to implicate α-dicarbonyl compounds in airway injury and flavorings-related lung disease.
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Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kathleen Kreiss
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kristin J Cummings
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kara L Fluharty
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Ryan O'Connell
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Allison Cole
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Tiana M Dodd
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Sidney M Clingerman
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Jordan R Flesher
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Rebecca Lee
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Samantha Pagel
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Lori A Battelli
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Amy Cumpston
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Mark Jackson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Michael Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Marlene S Orandle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Krishnan Sriram
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
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21
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Truman P, Stanfill S, Heydari A, Silver E, Fowles J. Monoamine oxidase inhibitory activity of flavoured e-cigarette liquids. Neurotoxicology 2019; 75:123-128. [PMID: 31536738 DOI: 10.1016/j.neuro.2019.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 09/09/2019] [Accepted: 09/13/2019] [Indexed: 01/24/2023]
Abstract
BACKGROUND AND AIMS Monoamine oxidase inhibitors have been hypothesised to be important in tobacco dependence, reinforcing the brain's response to nicotine by delaying the degradation of neurotransmitters by monoamine oxidases. The development of electronic cigarettes has provided an alternative nicotine delivery system, which is widely viewed as less toxic than tobacco smoke. However, significant data gaps remain. This paper reports the results of measurements of monoamine oxidase inhibitory activity in a small sample of commercially available, flavoured e-liquids. METHODS Twelve e-liquids were tested for monoamine oxidase inhibitory activity, using the kynuramine assay and monoamine oxidase enzymes (human, recombinant). Control samples of carrier liquids, propylene glycol and glycerol, and nicotine were also tested. RESULTS Four e-liquids contained high levels of inhibitory activity, four more were moderately inhibitory. The remaining four e-liquids were mildly inhibitory, while the carrier liquids, and nicotine were inactive at relevant concentrations. The active compounds in the e-liquids were subsequently identified as vanillin and ethyl vanillin. Under some conditions of use, the sampled e-liquids with the highest concentrations of monoamine oxidase inhibitory activity have the potential to expose consumers to physiologically significant levels of MAO inhibitory activity. CONCLUSIONS While only a small sample of e-liquids was tested, the findings suggest that some flavours have pharmacological actions, with potential to enhance the response to nicotine or to other drugs. The public health implications of these preliminary findings on addiction and smoking cessation warrant exploration and further research.
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Affiliation(s)
- Penelope Truman
- School of Health Sciences, Massey University Wellington, New Zealand.
| | - Stephen Stanfill
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ali Heydari
- School of Health Sciences, Massey University Wellington, New Zealand
| | | | - Jefferson Fowles
- Environmental Health Investigations Branch, California Department of Public Health, Richmond, CA, USA
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22
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Sahu KK, Mishra AK, Lal A, Siddiqui AD, Abraham GM. From Oncologist's Desk: Hemato-Oncological Aspect of Using Vaporizers, E-Cigarettes, and Other Electronic Nicotine Delivery Systems (ENDS). Indian J Hematol Blood Transfus 2019; 36:202-204. [PMID: 32158108 DOI: 10.1007/s12288-019-01177-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/29/2019] [Indexed: 12/12/2022] Open
Affiliation(s)
- Kamal Kant Sahu
- 1Department of Internal Medicine, Saint Vincent Hospital, 123 Summer Street, Worcester, MA 01608 USA
| | - Ajay Kumar Mishra
- 1Department of Internal Medicine, Saint Vincent Hospital, 123 Summer Street, Worcester, MA 01608 USA
| | - Amos Lal
- 2Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 1st St SW, Rochester, MN 55905 USA
| | - Ahmad Daniyal Siddiqui
- Division of Hematology and Medical Oncology, Saint Vincent Cancer and Wellness Center, 1 Eaton Place, Worcester, MA 01608 USA
| | - George M Abraham
- 1Department of Internal Medicine, Saint Vincent Hospital, 123 Summer Street, Worcester, MA 01608 USA.,4University of Massachusetts Medical School, 55 N Lake Ave, Worcester, MA 01608 USA
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23
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Wylie SL, Langlois D, Carey S, Nelson NC, Williams KJ. Constrictive Bronchiolitis Obliterans in a Dog. J Am Anim Hosp Assoc 2019; 55:e55201. [PMID: 30653359 DOI: 10.5326/jaaha-ms-6821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 2 yr old, neutered male rottweiler was evaluated for a chronic cough that had acutely worsened. Computed tomographic examination revealed a diffuse alveolar pattern in the right, middle, and left cranial lung lobes. Aerated parenchymal tissue was not observed in the left cranial lung lobe, and both lobes were markedly decreased in volume. Lobectomy of the right middle and left cranial lung lobes was performed. Histopathologic examination of both lungs identified alveolar collapse associated with marked chronic bronchial and bronchiolar luminal concentric fibrosis leading to reduced airway lumen diameter and bronchiolar destruction. The clinical signs and airway pathology were consistent with constrictive bronchiolitis obliterans. The dog remained stable for over 2 yr with glucocorticoid therapy and intermittent antimicrobics. Although the polypoid form of bronchiolitis obliterans has been described in cattle and occasionally in dogs, constrictive bronchiolitis obliterans has not been reported previously in veterinary species.
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Affiliation(s)
- Stacey Lynn Wylie
- From NorthStar VETS, Robbinsville, New Jersey (S.L.W.); Department of Small Animal Clinical Sciences (D.L., S.C.), and Department of Pathobiology and Diagnostic Investigation (K.J.W.), College of Veterinary Medicine, Michigan State University, East Lansing, Michigan; and College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina (N.C.N.)
| | - Daniel Langlois
- From NorthStar VETS, Robbinsville, New Jersey (S.L.W.); Department of Small Animal Clinical Sciences (D.L., S.C.), and Department of Pathobiology and Diagnostic Investigation (K.J.W.), College of Veterinary Medicine, Michigan State University, East Lansing, Michigan; and College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina (N.C.N.)
| | - Stephan Carey
- From NorthStar VETS, Robbinsville, New Jersey (S.L.W.); Department of Small Animal Clinical Sciences (D.L., S.C.), and Department of Pathobiology and Diagnostic Investigation (K.J.W.), College of Veterinary Medicine, Michigan State University, East Lansing, Michigan; and College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina (N.C.N.)
| | - Nathan C Nelson
- From NorthStar VETS, Robbinsville, New Jersey (S.L.W.); Department of Small Animal Clinical Sciences (D.L., S.C.), and Department of Pathobiology and Diagnostic Investigation (K.J.W.), College of Veterinary Medicine, Michigan State University, East Lansing, Michigan; and College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina (N.C.N.)
| | - Kurt J Williams
- From NorthStar VETS, Robbinsville, New Jersey (S.L.W.); Department of Small Animal Clinical Sciences (D.L., S.C.), and Department of Pathobiology and Diagnostic Investigation (K.J.W.), College of Veterinary Medicine, Michigan State University, East Lansing, Michigan; and College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina (N.C.N.)
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24
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Gwinn WM, Flake GP, Bousquet RW, Taylor GJ, Morgan DL. Airway injury in an in vitro human epithelium-fibroblast model of diacetyl vapor exposure: diacetyl-induced basal/suprabasal spongiosis. Inhal Toxicol 2018; 29:310-321. [PMID: 28984536 DOI: 10.1080/08958378.2017.1369604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Inhalation exposure to diacetyl (DA) is associated with obliterative bronchiolitis (OB) in workers and induces OB-like fibrotic airway lesions in rats. The pathogenesis of OB is poorly understood in part due to complex interactions between airway epithelial, mesenchymal and blood-derived inflammatory cells. DA-induced airway toxicity in the absence of recruited-inflammatory/immune cells was characterized using an air-liquid interface (ALI) model consisting of human airway epithelium with (Epi/FT) and without (Epi) a mesenchymal component. ALI cultures were exposed to 25 mM DA-derived vapors (using vapor cups) for 1 h on day 0, 2 and 4. In some experiments, the tissues were exposed to 2,3-hexanedione (Hex) which is structurally-similar, but much less fibrogenic than DA. Lactate dehydrogenase activity and day 6 histopathologic changes associated with epithelial injury, including basal/suprabasal spongiosis, were increased following exposure of Epi/FT tissues to DA but not control or Hex vapors. IL-1a, IL-6, IL-8, sIL-1Ra, TGFa, MCP-3 and TNFa proteins were increased following DA exposure of Epi/FT tissues; only IL-1a, IL-8, sIL-1Ra and TGFa were increased following exposure of Epi tissues. MMP-1, MMP-3 and TIMP-1 proteins were increased following DA exposure of Epi/FT tissues; whereas MMP-2, MMP-7 and TIMP-2 were decreased, and production was largely dependent upon the presence of sub-epithelial stromal matrix/fibroblasts. Hex-induced protein changes were minimal. This in vitro study demonstrated that exposure of human airways to DA vapors induced epithelial injury (with the histopathologic feature of basal/suprabasal spongiosis) and increased release of pro-inflammatory and pro-fibrotic cytokines/chemokines as well as MMPs/TIMPs in the absence of recruited-inflammatory cells.
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Affiliation(s)
- William M Gwinn
- a NTP Laboratory, Division of the National Toxicology Program (DNTP) , National Institute of Environmental Health Sciences (NIEHS) , Durham , NC , USA
| | - Gordon P Flake
- b Cell and Molecular Pathology Branch, DNTP, NIEHS , Durham , NC , USA
| | - Ronald W Bousquet
- c Alion Science and Technology Corporation , Research Triangle Park, Durham , NC , USA
| | - Genie J Taylor
- c Alion Science and Technology Corporation , Research Triangle Park, Durham , NC , USA
| | - Daniel L Morgan
- a NTP Laboratory, Division of the National Toxicology Program (DNTP) , National Institute of Environmental Health Sciences (NIEHS) , Durham , NC , USA
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25
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Kaur G, Muthumalage T, Rahman I. Mechanisms of toxicity and biomarkers of flavoring and flavor enhancing chemicals in emerging tobacco and non-tobacco products. Toxicol Lett 2018; 288:143-155. [PMID: 29481849 PMCID: PMC6549714 DOI: 10.1016/j.toxlet.2018.02.025] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 01/11/2023]
Abstract
Tobacco products containing flavorings, such as electronic nicotine delivery devices (ENDS) or e-cigarettes, cigars/cigarillos, waterpipes, and heat-not-burn devices (iQOS) are continuously evolving. In addition to increasing the exposure of teenagers and adults to nicotine containing flavoring products and flavoring enhancers, chances of nicotine addiction through chronic use and abuse also increase. These flavorings are believed to be safe for ingestion, but little information is available about their effects on the lungs. In this review, we have discussed the in vitro and in vivo data on toxicity of flavoring chemicals in lung cells. We have further discussed the common flavoring agents, such as diacetyl and menthol, currently available detection methods, and the toxicological mechanisms associated with oxidative stress, inflammation, mucociliary clearance, and DNA damage in cells, mice, and humans. Finally, we present potential biomarkers that could be utilized for future risk assessment. This review provides crucial parameters important for evaluation of risk associated with flavoring agents and flavoring enhancers used in tobacco products and ENDS. Future studies can be designed to address the potential toxicity of inhaled flavorings and their biomarkers in users as well as in chronic exposure studies.
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Affiliation(s)
- Gurjot Kaur
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA.
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26
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Disruptions in gut microbial-host co-metabolism and the development of metabolic disorders. Clin Sci (Lond) 2018; 132:791-811. [PMID: 29661926 DOI: 10.1042/cs20171328] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/20/2018] [Accepted: 02/23/2018] [Indexed: 12/14/2022]
Abstract
The microbial-mammalian metabolic axis has become recognized as an important component governing the overall homeostatic balance of the mammalian host. Disruption of the state of homeostasis among the gut microbiota has been shown to be causally linked to the development of host metabolic diseases including obesity, cardiovascular, diabetes, and fatty liver disease. This disruption is often referred to as gut dysbiosis. Gut dysbiosis leads to altered metabolic products derived from the microbiota and these in turn, typically shift the homeostatic metabolic balance of the host towards a low-grade chronic inflammation, a hallmark of metabolic syndrome. The primary objective of this review is to examine and discuss some very current research that has been done to study the effect of bacterial metabolites on host metabolism, sometimes referred to as microbiota-host co-metabolism. The metabolic conditions reviewed here include obesity, a known risk factor for all of the other metabolic conditions, as well as, cardiovascular disease, diabetes and nonalcoholic fatty liver disease. Only by further understanding the cause and result of gut dysbiosis will an adequate solution be found for metabolic disease, a viewpoint shared by many.
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27
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Muthumalage T, Prinz M, Ansah KO, Gerloff J, Sundar IK, Rahman I. Inflammatory and Oxidative Responses Induced by Exposure to Commonly Used e-Cigarette Flavoring Chemicals and Flavored e-Liquids without Nicotine. Front Physiol 2018; 8:1130. [PMID: 29375399 PMCID: PMC5768608 DOI: 10.3389/fphys.2017.01130] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 12/21/2017] [Indexed: 12/14/2022] Open
Abstract
Background: The respiratory health effects of inhalation exposure to e-cigarette flavoring chemicals are not well understood. We focused our study on the immuno-toxicological and the oxidative stress effects by these e-cigarette flavoring chemicals on two types of human monocytic cell lines, Mono Mac 6 (MM6) and U937. The potential to cause oxidative stress by these flavoring chemicals was assessed by measuring the production of reactive oxygen species (ROS). We hypothesized that the flavoring chemicals used in e-juices/e-liquids induce an inflammatory response, cellular toxicity, and ROS production. Methods: Two monocytic cell types, MM6 and U937 were exposed to commonly used e-cigarette flavoring chemicals; diacetyl, cinnamaldehyde, acetoin, pentanedione, o-vanillin, maltol and coumarin at different doses between 10 and 1,000 μM. Cell viability and the concentrations of the secreted inflammatory cytokine interleukin 8 (IL-8) were measured in the conditioned media. Cell-free ROS produced by these commonly used flavoring chemicals were also measured using a 2′,7′dichlorofluorescein diacetate probe. These DCF fluorescence data were expressed as hydrogen peroxide (H2O2) equivalents. Cytotoxicity due to the exposure to selected e-liquids was assessed by cell viability and the IL-8 inflammatory cytokine response in the conditioned media. Results: Treatment of the cells with flavoring chemicals and flavored e-liquid without nicotine caused cytotoxicity dose-dependently. The exposed monocytic cells secreted interleukin 8 (IL-8) chemokine in a dose-dependent manner compared to the unexposed cell groups depicting a biologically significant inflammatory response. The measurement of cell-free ROS by the flavoring chemicals and e-liquids showed significantly increased levels of H2O2 equivalents in a dose-dependent manner compared to the control reagents. Mixing a variety of flavors resulted in greater cytotoxicity and cell-free ROS levels compared to the treatments with individual flavors, suggesting that mixing of multiple flavors of e-liquids are more harmful to the users. Conclusions: Our data suggest that the flavorings used in e-juices can trigger an inflammatory response in monocytes, mediated by ROS production, providing insights into potential pulmonary toxicity and tissue damage in e-cigarette users.
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Affiliation(s)
- Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Melanie Prinz
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Kwadwo O Ansah
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Janice Gerloff
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Isaac K Sundar
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, United States
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28
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Klager S, Vallarino J, MacNaughton P, Christiani DC, Lu Q, Allen JG. Flavoring Chemicals and Aldehydes in E-Cigarette Emissions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10806-10813. [PMID: 28817267 DOI: 10.1021/acs.est.7b02205] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Regulations on e-cigarettes in the U.S. do not provide guidelines on the chemical content of e-cigarette liquids. We evaluated emissions of aldehydes and flavoring chemicals in e-cigarette vapor under typical usage conditions. We selected 24 e-cigarette flavors from the top selling disposable e-cigarette brands. E-cigarettes were connected to a pump drawing air for two second puffs with sixty-second intervals between puffs. The vapor was analyzed for the presence of aldehydes using high-performance liquid chromatography-ultraviolet detector and for the presence of flavoring chemicals with gas chromatography and an electron capture detector. All e-cigarette emissions tested contained at least one aldehyde and/or flavoring chemical on either the FEMA "High Priority Chemicals" or FDA Harmful and Potentially Harmful Constituents lists when sampled at typical usage conditions. Diacetyl, a known respiratory hazard, along with acetoin, were the most prevalent of the flavoring chemicals in e-cigarette vapor, being found in more than 60% of samples. The presence of propionaldehyde, acetaldehyde and formaldehyde were correlated, corroborating previous work suggesting thermal degradation as a pathway for aldehyde generation in e-cigarette vapors. Median formaldehyde concentrations of 626 μg/m3 in e-cigarette vapor exceed the ACGIH maximum concentrations allowable for workers of 370 μg/m3.
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Affiliation(s)
- Skylar Klager
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
| | - Jose Vallarino
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
| | - Piers MacNaughton
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
| | - David C Christiani
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
| | - Quan Lu
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
| | - Joseph G Allen
- Harvard T.H. Chan School of Public Health , 401 Park Drive Boston, Massachusetts 02215, United States
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29
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Brass DM, Palmer SM. Models of toxicity of diacetyl and alternative diones. Toxicology 2017; 388:15-20. [PMID: 28232124 PMCID: PMC5540796 DOI: 10.1016/j.tox.2017.02.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 01/23/2017] [Accepted: 02/17/2017] [Indexed: 11/28/2022]
Abstract
Diacetyl (DA; 2,3-butanedione), with the chemical formula (CH3CO)2 is a volatile organic compound with a deep yellow color and a strong buttery flavor and aroma. These properties have made DA a particularly useful and common food flavoring ingredient. However, because of this increased occupational use, workers can be exposed to high vapor concentrations in the workplace. Despite being listed by the USFDA to be 'generally regarded as safe' (GRAS), multiple lines of evidence suggest that exposure to high concentrations of DA vapor causes long-term impairments in lung function with lung function testing indicating evidence of either restrictive or obstructive airway narrowing in affected individuals. A growing number of pre-clinical studies have now addressed the short and long-term toxicity associated with DA exposure providing further insight into the toxicity of DA and related diones. This review summarizes these observations.
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Affiliation(s)
- David M Brass
- Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA.
| | - Scott M Palmer
- Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
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30
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Diacetyl and related flavorant α-Diketones: Biotransformation, cellular interactions, and respiratory-tract toxicity. Toxicology 2017; 388:21-29. [PMID: 28179188 DOI: 10.1016/j.tox.2017.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 01/26/2023]
Abstract
Exposure to diacetyl and related α-diketones causes respiratory-tract damage in humans and experimental animals. Chemical toxicity is often associated with covalent modification of cellular nucleophiles by electrophilic chemicals. Electrophilic α-diketones may covalently modify nucleophilic arginine residues in critical proteins and, thereby, produce the observed respiratory-tract pathology. The major pathway for the biotransformation of α-diketones is reduction to α-hydroxyketones (acyloins), which is catalyzed by NAD(P)H-dependent enzymes of the short-chain dehydrogenase/reductase (SDR) and the aldo-keto reductase (AKR) superfamilies. Reduction of α-diketones to the less electrophilic acyloins is a detoxication pathway for α-diketones. The pyruvate dehydrogenase complex may play a significant role in the biotransformation of diacetyl to CO2. The interaction of toxic electrophilic chemicals with cellular nucleophiles can be predicted by the hard and soft, acids and bases (HSAB) principle. Application of the HSAB principle to the interactions of electrophilic α-diketones with cellular nucleophiles shows that α-diketones react preferentially with arginine residues. Furthermore, the respiratory-tract toxicity and the quantum-chemical reactivity parameters of diacetyl and replacement flavorant α-diketones are similar. Hence, the identified replacement flavorant α-diketones may pose a risk of flavorant-induced respiratory-tract toxicity. The calculated indices for the reaction of α-diketones with arginine support the hypothesis that modification of protein-bound arginine residues is a critical event in α-diketone-induced respiratory-tract toxicity.
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31
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Foster MW, Gwinn WM, Kelly FL, Brass DM, Valente AM, Moseley MA, Thompson JW, Morgan DL, Palmer SM. Proteomic Analysis of Primary Human Airway Epithelial Cells Exposed to the Respiratory Toxicant Diacetyl. J Proteome Res 2017; 16:538-549. [PMID: 27966365 DOI: 10.1021/acs.jproteome.6b00672] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Occupational exposures to the diketone flavoring agent, diacetyl, have been associated with bronchiolitis obliterans, a rare condition of airway fibrosis. Model studies in rodents have suggested that the airway epithelium is a major site of diacetyl toxicity, but the effects of diacetyl exposure upon the human airway epithelium are poorly characterized. Here we performed quantitative LC-MS/MS-based proteomics to study the effects of repeated diacetyl vapor exposures on 3D organotypic cultures of human primary tracheobronchial epithelial cells. Using a label-free approach, we quantified approximately 3400 proteins and 5700 phosphopeptides in cell lysates across four independent donors. Altered expression of proteins and phosphopeptides were suggestive of loss of cilia and increased squamous differentiation in diacetyl-exposed cells. These phenomena were confirmed by immunofluorescence staining of culture cross sections. Hyperphosphorylation and cross-linking of basal cell keratins were also observed in diacetyl-treated cells, and we used parallel reaction monitoring to confidently localize and quantify previously uncharacterized sites of phosphorylation in keratin 6. Collectively, these data identify numerous molecular changes in the epithelium that may be important to the pathogenesis of flavoring-induced bronchiolitis obliterans. More generally, this study highlights the utility of quantitative proteomics for the study of in vitro models of airway injury and disease.
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Affiliation(s)
| | - William M Gwinn
- National Institute of Environmental Health Sciences , Research Triangle Park, North Carolina 27709, United States
| | | | | | | | | | | | - Daniel L Morgan
- National Institute of Environmental Health Sciences , Research Triangle Park, North Carolina 27709, United States
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32
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Hubbs AF, Fluharty KL, Edwards RJ, Barnabei JL, Grantham JT, Palmer SM, Kelly F, Sargent LM, Reynolds SH, Mercer RR, Goravanahally MP, Kashon ML, Honaker JC, Jackson MC, Cumpston AM, Goldsmith WT, McKinney W, Fedan JS, Battelli LA, Munro T, Bucklew-Moyers W, McKinstry K, Schwegler-Berry D, Friend S, Knepp AK, Smith SL, Sriram K. Accumulation of Ubiquitin and Sequestosome-1 Implicate Protein Damage in Diacetyl-Induced Cytotoxicity. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2887-2908. [PMID: 27643531 PMCID: PMC5222965 DOI: 10.1016/j.ajpath.2016.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/09/2016] [Accepted: 07/21/2016] [Indexed: 01/12/2023]
Abstract
Inhaled diacetyl vapors are associated with flavorings-related lung disease, a potentially fatal airway disease. The reactive α-dicarbonyl group in diacetyl causes protein damage in vitro. Dicarbonyl/l-xylulose reductase (DCXR) metabolizes diacetyl into acetoin, which lacks this α-dicarbonyl group. To investigate the hypothesis that flavorings-related lung disease is caused by in vivo protein damage, we correlated diacetyl-induced airway damage in mice with immunofluorescence for markers of protein turnover and autophagy. Western immunoblots identified shifts in ubiquitin pools. Diacetyl inhalation caused dose-dependent increases in bronchial epithelial cells with puncta of both total ubiquitin and K63-ubiquitin, central mediators of protein turnover. This response was greater in Dcxr-knockout mice than in wild-type controls inhaling 200 ppm diacetyl, further implicating the α-dicarbonyl group in protein damage. Western immunoblots demonstrated decreased free ubiquitin in airway-enriched fractions. Transmission electron microscopy and colocalization of ubiquitin-positive puncta with lysosomal-associated membrane proteins 1 and 2 and with the multifunctional scaffolding protein sequestosome-1 (SQSTM1/p62) confirmed autophagy. Surprisingly, immunoreactive SQSTM1 also accumulated in the olfactory bulb of the brain. Olfactory bulb SQSTM1 often congregated in activated microglial cells that also contained olfactory marker protein, indicating neuronophagia within the olfactory bulb. This suggests the possibility that SQSTM1 or damaged proteins may be transported from the nose to the brain. Together, these findings strongly implicate widespread protein damage in the etiology of flavorings-related lung disease.
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Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia.
| | - Kara L Fluharty
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Rebekah J Edwards
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Jamie L Barnabei
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - John T Grantham
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; School of Medicine, West Virginia University, Morgantown, West Virginia
| | - Scott M Palmer
- Duke University School of Medicine, Durham, North Carolina
| | - Francine Kelly
- Duke University School of Medicine, Durham, North Carolina
| | - Linda M Sargent
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Steven H Reynolds
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Robert R Mercer
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Madhusudan P Goravanahally
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Centers for Neuroscience, West Virginia University, Morgantown, West Virginia
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - John C Honaker
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Mark C Jackson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Amy M Cumpston
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - William T Goldsmith
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Walter McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Lori A Battelli
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Tiffany Munro
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Winnie Bucklew-Moyers
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Kimberly McKinstry
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Diane Schwegler-Berry
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Sherri Friend
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Alycia K Knepp
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Samantha L Smith
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Krishnan Sriram
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
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Flake GP, Morgan DL. Pathology of diacetyl and 2,3-pentanedione airway lesions in a rat model of obliterative bronchiolitis. Toxicology 2016; 388:40-47. [PMID: 27984136 DOI: 10.1016/j.tox.2016.10.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/18/2016] [Accepted: 10/27/2016] [Indexed: 11/29/2022]
Abstract
Inhalation of diacetyl vapors by workers has been associated with obliterative bronchiolitis (OB), a poorly understood fibroproliferative disease of the small airways. Significant insights into the pathogenesis of OB have been obtained through the use of a rat model. Inhalation exposure of rats to diacetyl or 2,3-pentanedione, a related flavoring agent, can cause severe injury to the airway epithelium and underlying basement membrane. Repeated exposure to diacetyl or 2,3-pentanedione leads to aberrant repair, fibroproliferation and partial to complete occlusion of the airway lumen. Fibroproliferative lesions in rat airways were found to include both intraluminal polyps and circumferential intramural lesions. Intraluminal polyps have been observed to form secondary attachments spanning the airway lumen causing increasing obstruction. These airway lesions in rats are accompanied by inflammation in the form of peribronchial and perivascular infiltrates of lymphocytes, eosinophils and neutrophils. Diacetyl-induced OB lesions in the rat are similar to OB lesions in humans and provide a good model for studying the pathogenesis of this disease.
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Affiliation(s)
- Gordon P Flake
- Cellular and Molecular Pathology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States
| | - Daniel L Morgan
- Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, United States.
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Duling MG, LeBouf RF, Cox-Ganser JM, Kreiss K, Martin SB, Bailey RL. Environmental characterization of a coffee processing workplace with obliterative bronchiolitis in former workers. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2016; 13:770-81. [PMID: 27105025 PMCID: PMC5836548 DOI: 10.1080/15459624.2016.1177649] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Obliterative bronchiolitis in five former coffee processing employees at a single workplace prompted an exposure study of current workers. Exposure characterization was performed by observing processes, assessing the ventilation system and pressure relationships, analyzing headspace of flavoring samples, and collecting and analyzing personal breathing zone and area air samples for diacetyl and 2,3-pentanedione vapors and total inhalable dust by work area and job title. Mean airborne concentrations were calculated using the minimum variance unbiased estimator of the arithmetic mean. Workers in the grinding/packaging area for unflavored coffee had the highest mean diacetyl exposures, with personal concentrations averaging 93 parts per billion (ppb). This area was under positive pressure with respect to flavored coffee production (mean personal diacetyl levels of 80 ppb). The 2,3-pentanedione exposures were highest in the flavoring room with mean personal exposures of 122 ppb, followed by exposures in the unflavored coffee grinding/packaging area (53 ppb). Peak 15-min airborne concentrations of 14,300 ppb diacetyl and 13,800 ppb 2,3-pentanedione were measured at a small open hatch in the lid of a hopper containing ground unflavored coffee on the mezzanine over the grinding/packaging area. Three out of the four bulk coffee flavorings tested had at least a factor of two higher 2,3-pentanedione than diacetyl headspace measurements. At a coffee processing facility producing both unflavored and flavored coffee, we found the grinding and packaging of unflavored coffee generate simultaneous exposures to diacetyl and 2,3-pentanedione that were well in excess of the NIOSH proposed RELs and similar in magnitude to those in the areas using a flavoring substitute for diacetyl. These findings require physicians to be alert for obliterative bronchiolitis and employers, government, and public health consultants to assess the similarities and differences across the industry to motivate preventive intervention where indicated by exposures above the proposed RELs for diacetyl and 2,3-pentanedione.
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Affiliation(s)
- Matthew G Duling
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
| | - Ryan F LeBouf
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
| | - Jean M Cox-Ganser
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
| | - Kathleen Kreiss
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
| | - Stephen B Martin
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
| | - Rachel L Bailey
- a Centers for Disease Control and Prevention (CDC), National Institute for Occupational Safety and Health (NIOSH), Respiratory Health Division , Morgantown , West Virginia
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Zhang SB, Sun X, Wu Q, Wu JP, Chen HY. Impaired Capacity of Fibroblasts to Support Airway Epithelial Progenitors in Bronchiolitis Obliterans Syndrome. Chin Med J (Engl) 2016; 129:2040-4. [PMID: 27569228 PMCID: PMC5009585 DOI: 10.4103/0366-6999.189058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Bronchiolitis obliterans syndrome (BOS) often develops in transplant patients and results in injury to the respiratory and terminal airway epithelium. Owing to its rising incidence, the pathogenesis of BOS is currently an area of intensive research. Studies have shown that injury to the respiratory epithelium results in dysregulation of epithelial repair. Airway epithelial regeneration is supported by stromal cells, including fibroblasts. This study aimed to investigate whether the supportive role of lung fibroblasts is altered in BOS. METHODS Suspensions of lung cells were prepared by enzyme digestion. Lung progenitor cells (LPCs) were separated by fluorescence-activated cell sorting. Lung fibroblasts from patients with BOS or healthy controls were mixed with sorted mouse LPCs to compare the colony-forming efficiency of LPCs by counting the number of colonies with a diameter of ≥50 μm in each culture. Statistical analyses were performed using the SPSS 17.0 software (SPSS Inc., USA). The paired Student's t-test was used to test for statistical significance. RESULTS LPCs were isolated with the surface phenotype of CD31-CD34-CD45- EpCAM+Sca-1+. The colony-forming efficiency of LPCs was significantly reduced when co-cultured with fibroblasts isolated from patients with BOS. The addition of SB431542 increased the colony-forming efficiency of LPCs to 1.8%; however, it was still significantly less than that in co-culture with healthy control fibroblasts (P < 0.05). CONCLUSION The epithelial-supportive capacity of fibroblasts is impaired in the development of BOS and suggest that inefficient repair of airway epithelium could contribute to persistent airway inflammation in BOS.
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Affiliation(s)
- Su-Bei Zhang
- Haihe Clinical College of Tianjin Medical University, Tianjin 300070, China
| | - Xin Sun
- Key Research Laboratory for Infectious Disease Prevention for State Administration of Traditional Chinese Medicine, Tianjin Institute of Respiratory Diseases, Tianjin Haihe Hospital, Tianjin 300350, China
| | - Qi Wu
- Tianjin Institute of Respiratory Diseases, Tianjin Haihe Hospital, Tianjin 300350, China
- Address for correspondence: Prof. Qi Wu, Tianjin Institute of Respiratory Diseases, Tianjin Haihe Hospital, Tianjin 300350, China E-Mail:
| | - Jun-Ping Wu
- Department of Respiratory, Tianjin Haihe Hospital, Tianjin 300350, China
| | - Huai-Yong Chen
- Department of Basic Medicine, Tianjin Haihe Hospital, Tianjin 300350, China
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Reid D, McDonald B, Khalid T, Vo T, Schenck L, Surette M, Beck P, Reimer R, Probert C, Rioux K, Eksteen B. Unique microbial-derived volatile organic compounds in portal venous circulation in murine non-alcoholic fatty liver disease. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1337-44. [DOI: 10.1016/j.bbadis.2016.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/15/2016] [Accepted: 04/03/2016] [Indexed: 12/23/2022]
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Kreiss K. Recognizing occupational effects of diacetyl: What can we learn from this history? Toxicology 2016; 388:48-54. [PMID: 27326900 DOI: 10.1016/j.tox.2016.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 10/21/2022]
Abstract
For half of the 30-odd years that diacetyl-exposed workers have developed disabling lung disease, obliterative bronchiolitis was unrecognized as an occupational risk. Delays in its recognition as an occupational lung disease are attributable to the absence of a work-related temporal pattern of symptoms; failure to recognize clusters of cases; complexity of exposure environments; and absence of epidemiologic characterization of workforces giving rise to case clusters. Few physicians are familiar with this rare disease, and motivation to investigate the unknown requires familiarity with what is known and what is anomalous. In pursuit of the previously undescribed risk, investigators benefited greatly from multi-disciplinary collaboration, in this case including physicians, epidemiologists, environmental scientists, toxicologists, industry representatives, and worker advocates. In the 15 years since obliterative bronchiolitis was described in microwave popcorn workers, α-dicarbonyl-related lung disease has been found in flavoring manufacturing workers, other food production workers, diacetyl manufacturing workers, and coffee production workers, alongside case reports in other industries. Within the field of occupational health, impacts include new ventures in public health surveillance, attention to spirometry quality for serial measurements, identifying other indolent causes of obliterative bronchiolitis apart from accidental over-exposures, and broadening the spectrum of diagnostic abnormalities in the disease. Within toxicology, impacts include new attention to appropriate animal models of obliterative bronchiolitis, pertinence of computational fluid dynamic-physiologically based pharmacokinetic modeling, and contributions to mechanistic understanding of respiratory epithelial necrosis, airway fibrosis, and central nervous system effects. In these continuing efforts, collaboration between laboratory scientists, clinicians, occupational public health practitioners in government and industry, and employers remains critical for improving the health of workers inhaling volatile α-dicarbonyl compounds.
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Affiliation(s)
- Kathleen Kreiss
- Division of Respiratory Health, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown WV, United States.
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40
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Bailey RL, Cox-Ganser JM, Duling MG, LeBouf RF, Martin SB, Bledsoe TA, Green BJ, Kreiss K. Respiratory morbidity in a coffee processing workplace with sentinel obliterative bronchiolitis cases. Am J Ind Med 2015; 58:1235-45. [PMID: 26523478 DOI: 10.1002/ajim.22533] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2015] [Indexed: 11/09/2022]
Abstract
RATIONALE Obliterative bronchiolitis in former coffee workers prompted a cross-sectional study of current workers. Diacetyl and 2,3-pentanedione levels were highest in areas for flavoring and grinding/packaging unflavored coffee. METHODS We interviewed 75 (88%) workers, measured lung function, and created exposure groups based on work history. We calculated standardized morbidity ratios (SMRs) for symptoms and spirometric abnormalities. We examined health outcomes by exposure groups. RESULTS SMRs were elevated 1.6-fold for dyspnea and 2.7-fold for obstruction. The exposure group working in both coffee flavoring and grinding/packaging of unflavored coffee areas had significantly lower mean ratio of forced expiratory volume in 1 s to forced vital capacity and percent predicted mid-expiratory flow than workers without such exposure. CONCLUSION Current workers have occupational lung morbidity associated with high diacetyl and 2,3-pentanedione exposures, which were not limited to flavoring areas.
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Affiliation(s)
- Rachel L. Bailey
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
| | - Jean M. Cox-Ganser
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
| | - Matthew G. Duling
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
| | - Ryan F. LeBouf
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
| | - Stephen B. Martin
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
| | - Toni A. Bledsoe
- CDC, NIOSH, Health Effects Laboratory Division; Allergy and Clinical Immunology Branch; Morgantown WV
| | - Brett J. Green
- CDC, NIOSH, Health Effects Laboratory Division; Allergy and Clinical Immunology Branch; Morgantown WV
| | - Kathleen Kreiss
- Centers for Disease Control and Prevention (CDC); National Institute for Occupational Safety and Health (NIOSH); Respiratory Health Division, Field Studies Branch; Morgantown WV
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Kerger BD, Fedoruk MJ. Pathology, toxicology, and latency of irritant gases known to cause bronchiolitis obliterans disease: Does diacetyl fit the pattern? Toxicol Rep 2015; 2:1463-1472. [PMID: 28962489 PMCID: PMC5598164 DOI: 10.1016/j.toxrep.2015.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/21/2015] [Indexed: 12/22/2022] Open
Abstract
Bronchiolitis obliterans (BO) is a rare disease involving concentric bronchiolar fibrosis that develops rapidly following inhalation of certain irritant gases at sufficiently high acute doses. While there are many potential causes of bronchiolar lesions involved in a variety of chronic lung diseases, failure to clearly define the clinical features and pathological characteristics can lead to ambiguous diagnoses. Irritant gases known to cause BO follow a similar pathologic process and time course of disease onset in humans. Studies of inhaled irritant gases known to cause BO (e.g., chlorine, hydrochloric acid, ammonia, nitrogen oxides, sulfur oxides, sulfur or nitrogen mustards, and phosgene) indicate that the time course between causal chemical exposures and development of clinically significant BO disease is typically limited to a few months. The mechanism of toxic action exerted by these irritant gases generally involves widespread and severe injury of the epithelial lining of the bronchioles that leads to acute respiratory symptoms which can include lung edema within days. Repeated exposures to inhaled irritant gases at concentrations insufficient to cause marked respiratory distress or edema may lead to adaptive responses that can reduce or prevent severe bronchiolar fibrotic changes. Risk of BO from irritant gases is driven substantially by toxicokinetics affecting concentrations occurring at the bronchiolar epithelium. Highly soluble irritant gases that cause BO like ammonia generally follow a threshold-dependent cytotoxic mechanism of action that at sufficiently high doses results in severe inflammation of the upper respiratory tract and the bronchiolar epithelium concurrently. This is followed by acute respiratory distress, pulmonary edema, and post inflammatory concentric fibrosis that become clinically obvious within a few months. In contrast, irritant gases with lower solubility like phosgene also follow a threshold-dependent mechanism of cytotoxicity action but can exhibit more insidious and isolated bronchiolar tissue damage with a similar latency to fibrosis. To date, animal and human studies on the highly soluble gas, diacetyl, have not identified a coherent pattern of pathology and latency that would be expected based on studies of other known causes of bronchiolitis obliterans disease.
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Zaccone EJ, Goldsmith WT, Shimko MJ, Wells JR, Schwegler-Berry D, Willard PA, Case SL, Thompson JA, Fedan JS. Diacetyl and 2,3-pentanedione exposure of human cultured airway epithelial cells: Ion transport effects and metabolism of butter flavoring agents. Toxicol Appl Pharmacol 2015; 289:542-9. [PMID: 26454031 DOI: 10.1016/j.taap.2015.10.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 09/04/2015] [Accepted: 10/06/2015] [Indexed: 11/29/2022]
Abstract
Inhalation of butter flavoring by workers in the microwave popcorn industry may result in “popcorn workers' lung.” In previous in vivo studies rats exposed for 6 h to vapor from the flavoring agents, diacetyl and 2,3-pentanedione, acquired flavoring concentration-dependent damage of the upper airway epithelium and airway hyporeactivity to inhaled methacholine. Because ion transport is essential for lung fluid balance,we hypothesized that alterations in ion transport may be an early manifestation of butter flavoring-induced toxicity.We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 h to diacetyl or 2,3-pentanedione vapors (25 or ≥ 60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport,without affecting Cl- transport or Na+,K+-pump activity. Rt was unaffected. Na+ transport recovered 18 h after exposure. Concentrations (100-360 ppm) of diacetyl and 2,3-pentanedione reported earlier to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 h post-exposure. Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro.
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Affiliation(s)
- Eric J Zaccone
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - W Travis Goldsmith
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Michael J Shimko
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - J R Wells
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Diane Schwegler-Berry
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Patsy A Willard
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Shannon L Case
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Janet A Thompson
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Jeffrey S Fedan
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA; Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
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Henkler F, Luch A. European Tobacco Product Directive: How to address characterizing flavors as a matter of attractiveness? Arch Toxicol 2015; 89:1395-8. [PMID: 26138684 DOI: 10.1007/s00204-015-1563-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Frank Henkler
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany
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Cummings KJ, Kreiss K. Occupational and environmental bronchiolar disorders. Semin Respir Crit Care Med 2015; 36:366-78. [PMID: 26024345 DOI: 10.1055/s-0035-1549452] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Occupational and environmental causes of bronchiolar disorders are recognized on the basis of case reports, case series, and, less commonly, epidemiologic investigations. Pathology may be limited to the bronchioles or also involve other components of the respiratory tract, including the alveoli. A range of clinical, functional, and radiographic findings, including symptomatic disease lacking abnormalities on noninvasive testing, poses a diagnostic challenge and highlights the value of surgical biopsy. Disease clusters in workplaces and communities have identified new etiologies, drawn attention to indolent disease that may otherwise have been categorized as idiopathic, and expanded the spectrum of histopathologic responses to an exposure. More sensitive noninvasive diagnostic tools, evidence-based therapies, and ongoing epidemiologic investigation of at-risk populations are needed to identify, treat, and prevent exposure-related bronchiolar disorders.
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Affiliation(s)
- Kristin J Cummings
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Kathleen Kreiss
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
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Curwin BD, Deddens JA, McKernan LT. Flavoring exposure in food manufacturing. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2015; 25:324-33. [PMID: 25052692 PMCID: PMC4520397 DOI: 10.1038/jes.2014.52] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 05/22/2014] [Indexed: 05/25/2023]
Abstract
Flavorings are substances that alter or enhance the taste of food. Workers in the food-manufacturing industry, where flavorings are added to many products, may be exposed to any number of flavoring compounds. Although thousands of flavoring substances are in use, little is known about most of these in terms of worker health effects, and few have occupational exposure guidelines. Exposure assessment surveys were conducted at nine food production facilities and one flavor manufacturer where a total of 105 area and 74 personal samples were collected for 13 flavoring compounds including five ketones, five aldehydes, and three acids. The majority of the samples were below the limit of detection (LOD) for most compounds. Diacetyl had eight area and four personal samples above the LOD, whereas 2,3-pentanedione had three area samples above the LOD. The detectable values ranged from 25-3124 ppb and 15-172 ppb for diacetyl and 2,3-pentanedione respectively. These values exceed the proposed National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit for these compounds. The aldehydes had the most detectable samples, with each of them having >50% of the samples above the LOD. Acetaldehyde had all but two samples above the LOD, however, these samples were below the OSHA PEL. It appears that in the food-manufacturing facilities surveyed here, exposure to the ketones occurs infrequently, however levels above the proposed NIOSH REL were found. Conversely, aldehyde exposure appears to be ubiquitous.
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Affiliation(s)
- Brian D. Curwin
- Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | - Jim A. Deddens
- Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
| | - Lauralynn T. McKernan
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA
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Hubbs AF, Cummings KJ, McKernan LT, Dankovic DA, Park RM, Kreiss K. Comment on Farsalinos et al., "Evaluation of Electronic Cigarette Liquids and Aerosol for the Presence of Selected Inhalation Toxins". Nicotine Tob Res 2015; 17:1288-9. [PMID: 25586777 DOI: 10.1093/ntr/ntu338] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 12/01/2014] [Indexed: 11/12/2022]
Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV;
| | - Kristin J Cummings
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV
| | - Lauralynn Taylor McKernan
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, OH
| | - David A Dankovic
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, OH
| | - Robert M Park
- Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, OH
| | - Kathleen Kreiss
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV
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Evaluation of four α-diketones for toll-like receptor-4 (TLR-4) activation in a human transfected cell line. Food Chem Toxicol 2014; 74:117-9. [PMID: 25280922 DOI: 10.1016/j.fct.2014.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Revised: 09/18/2014] [Accepted: 09/22/2014] [Indexed: 01/04/2023]
Abstract
Toll-like receptor-4 (TLR-4) activity is upregulated in persons with fibrotic lung diseases secondary to chronic inflammatory conditions like Crohn's disease and rheumatoid arthritis. We hypothesized that α-diketones associated with fixed obstructive lung disease may activate TLR-4. We utilized a human embryonic kidney cell assay (HEK293) with human TLR-4 receptors to test for potential activation effects of 2,3-butandeione, 2,3-pentanedione, 2,3-hexanedione, and 2,3-heptanedione at test concentrations of 1, 10, 100, and 1000 µM. The assay detects NF-κB-induced expression of secreted alkaline phosphatase measured after 16 h incubation by a UV-VIS Spectrometer at 650 nm. Escherichia coli K12 lipopolysaccharide (LPS) at 0.5 ng/mL served as a positive control and was added with each test compound to evaluate combined effects. None of the tested α-diketones were found to exhibit cytotoxicity, agonism, or synergistic effects with LPS in the human TLR-4 assay up to 1000 µM. Screening of 2,3-butanedione for agonist activity using the HEK assay with mouse TLR-4 receptors exhibited cytotoxicity at 1000 µM, but no agonist activity. We conclude that the tested α-diketones at relatively high concentrations in vitro do not exhibit TLR-4 agonist or synergistic activity and, therefore, apparently do not directly induce inflammasome activation through this pathway in humans or mice.
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Farsalinos KE, Kistler KA, Gillman G, Voudris V. Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins. Nicotine Tob Res 2014; 17:168-74. [PMID: 25180080 DOI: 10.1093/ntr/ntu176] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION The purpose of this study was to evaluate sweet-flavored electronic cigarette (EC) liquids for the presence of diacetyl (DA) and acetyl propionyl (AP), which are chemicals approved for food use but are associated with respiratory disease when inhaled. METHODS In total, 159 samples were purchased from 36 manufacturers and retailers in 7 countries. Additionally, 3 liquids were prepared by dissolving a concentrated flavor sample of known DA and AP levels at 5%, 10%, and 20% concentration in a mixture of propylene glycol and glycerol. Aerosol produced by an EC was analyzed to determine the concentration of DA and AP. RESULTS DA and AP were found in 74.2% of the samples, with more samples containing DA. Similar concentrations were found in liquid and aerosol for both chemicals. The median daily exposure levels were 56 μg/day (IQR: 26-278 μg/day) for DA and 91 μg/day (IQR: 20-432 μg/day) for AP. They were slightly lower than the strict NIOSH-defined safety limits for occupational exposure and 100 and 10 times lower compared with smoking respectively; however, 47.3% of DA and 41.5% of AP-containing samples exposed consumers to levels higher than the safety limits. CONCLUSIONS DA and AP were found in a large proportion of sweet-flavored EC liquids, with many of them exposing users to higher than safety levels. Their presence in EC liquids represents an avoidable risk. Proper measures should be taken by EC liquid manufacturers and flavoring suppliers to eliminate these hazards from the products without necessarily limiting the availability of sweet flavors.
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Affiliation(s)
| | - Kurt A Kistler
- Department of Chemistry, Pennsylvania State University Brandywine, Media, PA
| | | | - Vassilis Voudris
- Department of Cardiology, Onassis Cardiac Surgery Center, Kallithea, Greece
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Pierce JS, Abelmann A, Finley BL. Response to Muge Akpinar-Elci Letter to Editor re. Pierce et al., Diacetyl and 2,3-pentanedione exposures associated with cigarette smoking: implications for risk assessment of food and flavoring workers, Crit. Rev. Toxicol. 44(5):420-435, 2014. Crit Rev Toxicol 2014; 44:640-1. [PMID: 25068493 DOI: 10.3109/10408444.2014.930093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Cummings KJ, Boylstein RJ, Stanton ML, Piacitelli CA, Edwards NT, LeBouf RF, Kreiss K. Respiratory symptoms and lung function abnormalities related to work at a flavouring manufacturing facility. Occup Environ Med 2014; 71:549-54. [PMID: 24891557 DOI: 10.1136/oemed-2013-101927] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To better understand respiratory symptoms and lung function in flavouring manufacturing workers. METHODS We offered a questionnaire and lung function testing to the current workforce of a flavouring manufacturing facility that had transitioned away from diacetyl and towards substitutes in recent years. We examined symptoms, spirometric parameters and diffusing capacity measurements by exposure variables, including facility tenure and time spent daily in production areas. We used linear and logistic regression to develop final models adjusted for age and smoking status. RESULTS A total of 367 (93%) current workers participated. Shortness of breath was twice as common in those with tenure ≥ 7 years (OR 2.0, 95% CI 1.1 to 3.6). Other chest symptoms were associated with time spent daily in production. Participants who spent ≥ 1 h daily in production areas had twice the odds of any spirometric abnormality (OR 2.3; 95% CI 1.1 to 5.3) and three times the odds of low diffusing capacity (OR 2.8; 95% CI 0.9 to 9.4) than other participants. Mean spirometric parameters were significantly lower in those with tenure ≥ 7 years and those who spent ≥ 1 h daily in production. Mean diffusing capacity parameters were significantly lower in those with tenure ≥ 7 years. Differences in symptoms and lung function could not be explained by age, smoking status or employment at another flavouring plant. CONCLUSIONS Symptoms and lung function findings were consistent with undiagnosed or subclinical obliterative bronchiolitis and associated with workplace exposures. Further efforts to lower exposures to flavouring chemicals, including diacetyl substitutes, are warranted.
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Affiliation(s)
- Kristin J Cummings
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Randy J Boylstein
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Marcia L Stanton
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Chris A Piacitelli
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Nicole T Edwards
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Ryan F LeBouf
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
| | - Kathleen Kreiss
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia, USA
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