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Vitucci ECM, Oladeji O, Presto AA, Cannon CL, Johnson NM. The application of PTR-MS and non-targeted analysis to characterize VOCs emitted from a plastic recycling facility fire. J Expo Sci Environ Epidemiol 2024:10.1038/s41370-024-00681-y. [PMID: 38710768 DOI: 10.1038/s41370-024-00681-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND On April 11th, 2023, the My Way Trading (MWT) recycling facility in Richmond, Indiana caught fire, mandating the evacuation of local residents and necessitating the U.S. Environmental Protection Agency (EPA) to conduct air monitoring. The EPA detected elevated levels of plastic combustion-related air pollutants, including hydrogen cyanide and benzene. OBJECTIVE We aimed to identify these and other volatile organic compounds (VOCs) present as well as to identify the potential hazard of each compound for various human health effects. METHODS To identify the VOCs, we conducted air monitoring at sites within and bordering the evacuation zone using proton transfer reaction mass spectrometry (PTR-MS) and non-targeted analysis (NTA). To facilitate risk assessment of the emitted VOCs, we used the EPA Hazard Comparison Dashboard. RESULTS We identified 46 VOCs, within and outside the evacuation zone, with average detection levels above local background levels measured in Middletown, OH. Levels of hydrogen cyanide and 4 other VOCs were at least 1.8-fold higher near the incidence site in comparison to background levels and displayed unique temporal and spatial patterns. The 46 VOCs identified had the highest hazardous potential for eye and skin irritation, with approximately 45% and 39%, respectively, of the VOCs classified as high and very high hazards for these endpoints. Notably, all detected VOC levels were below the hazard thresholds set for single VOC exposures; however, hazard thresholds for exposure to VOC mixtures are currently unclear. IMPACT This study serves as a proof-of-concept that PTR-MS coupled with NTA can facilitate rapid identification and hazard assessment of VOCs emitted following anthropogenic disasters. Furthermore, it demonstrates that this approach may augment future disaster responses to quantify additional VOCs present in complex combustion mixtures.
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Affiliation(s)
- Eva C M Vitucci
- Department of Environmental and Occupational Health, Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, 77843, USA
| | - Oladayo Oladeji
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Albert A Presto
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Carolyn L Cannon
- Department of Microbial Pathogenesis and Immunology, School of Medicine, Texas A&M University, Bryan, TX, 77807, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, 77843, USA.
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2
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Roh T, Regan AK, Johnson NM, Hasan NT, Trisha NF, Aggarwal A, Han D. Association of arsenic exposure with measles antibody titers in US children: Influence of sex and serum folate levels. Environ Int 2024; 183:108329. [PMID: 38071850 DOI: 10.1016/j.envint.2023.108329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/18/2023] [Accepted: 11/14/2023] [Indexed: 01/25/2024]
Abstract
Exposure to arsenic during childhood is associated with various adverse health conditions. However, little is known about the effect of arsenic exposure on vaccine-related humoral immunity in children. We analyzed data from the National Health and Nutrition Examination Survey (2003-2004 and 2009-2010) to study the relationship between urinary arsenic and measles antibody levels in 476 US children aged 6-11. Multivariable linear regression was used to evaluate the association, adjusting for cycle, age, race, body mass index (BMI), serum cotinine, poverty index ratio, and vitamin B12 and selenium intakes. Stratified analyses were conducted by sex and serum folate levels using the median as cutoff (18.7 ng/mL). The measles antibody concentrations in the 3rd and 4th quartiles were found to have significantly decreased by 28.5 % (95 % Confidence Interval (CI) -47.6, -2.28) and 36.8 % (95 % CI -50.2, -19.5), compared to the lowest quartile among boys with serum folate levels lower than 18.7 ng/ml. The serum measles antibody titers significantly decreased by 16.7 % (95 %CI -25.0, -7.61) for each doubling of creatinine-corrected urinary total inorganic arsenic concentrations in the same group. No associations were found in boys with high serum folate levels or in girls. Further prospective studies are needed to validate these findings and develop interventions to protect children from infectious diseases.
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Affiliation(s)
- Taehyun Roh
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77843, USA.
| | - Annette K Regan
- School of Nursing and Health Professions, University of San Francisco, San Francisco, CA 94117, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX 77843, USA
| | - Nishat Tasnim Hasan
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77843, USA
| | - Nusrat Fahmida Trisha
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77843, USA
| | - Anisha Aggarwal
- Department of Health Behavior, School of Public Health, Texas A&M University, College Station, TX 77843, USA
| | - Daikwon Han
- Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77843, USA
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3
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Oladeji O, Saitas M, Mustapha T, Johnson NM, Chiu WA, Rusyn I, Robinson AL, Presto AA. Air Pollutant Patterns and Human Health Risk following the East Palestine, Ohio, Train Derailment. Environ Sci Technol Lett 2023; 10:680-685. [PMID: 37577363 PMCID: PMC10413936 DOI: 10.1021/acs.estlett.3c00324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/16/2023] [Accepted: 06/20/2023] [Indexed: 08/15/2023]
Abstract
On February 3, 2023, a train carrying numerous hazardous chemicals derailed in East Palestine, OH, spurring temporary evacuation of residents and a controlled burn of some of the hazardous cargo. Residents reported health symptoms, including headaches and respiratory, skin, and eye irritation. Initial data from U.S. Environmental Protection Agency (EPA) stationary air monitors indicated levels of potential concern for air toxics based on hazard quotient calculations. To provide complementary data, we conducted mobile air quality sampling on February 20 and 21 using proton transfer reaction-mass spectrometry. Measurements were taken at 1 s intervals along routes designed to sample both close to and farther from the derailment. Mobile air monitoring indicated that average concentrations of benzene, toluene, xylenes, and vinyl chloride were below minimal risk levels for intermediate and chronic exposures, similar to EPA stationary monitoring data. Levels of acrolein were high relative to those of other volatile organic compounds, with spatial analyses showing levels in East Palestine up to 6 times higher than the local rural background. Nontargeted analyses identified levels of additional unique compounds above background levels, some displaying spatiotemporal patterns similar to that of acrolein and others exhibiting distinct hot spots. These initial findings warrant follow-up mobile air quality monitoring to characterize longitudinal exposure and risk levels.
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Affiliation(s)
- Oladayo Oladeji
- Department
of Mechanical Engineering, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Mariana Saitas
- Department
of Environmental and Occupational Health, Interdisciplinary Faculty
of Toxicology, Texas A&M University, College Station, Texas 77843, United States
| | - Toriq Mustapha
- Department
of Environmental and Occupational Health, Interdisciplinary Faculty
of Toxicology, Texas A&M University, College Station, Texas 77843, United States
| | - Natalie M. Johnson
- Department
of Environmental and Occupational Health, Interdisciplinary Faculty
of Toxicology, Texas A&M University, College Station, Texas 77843, United States
| | - Weihsueh A. Chiu
- Department
of Veterinary Physiology and Pharmacology, Interdisciplinary Faculty
of Toxicology, Texas A&M University, College Station, Texas 77843, United States
| | - Ivan Rusyn
- Department
of Veterinary Physiology and Pharmacology, Interdisciplinary Faculty
of Toxicology, Texas A&M University, College Station, Texas 77843, United States
| | - Allen L. Robinson
- Department
of Mechanical Engineering, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
| | - Albert A. Presto
- Department
of Mechanical Engineering, Carnegie Mellon
University, Pittsburgh, Pennsylvania 15213, United States
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4
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Drury NL, Mustapha T, Shore RA, Zhao J, Wright GA, Hoffmann AR, Talcott SU, Regan A, Tighe RM, Zhang R, Johnson NM. Maternal exposure to ultrafine particles enhances influenza infection during pregnancy. Part Fibre Toxicol 2023; 20:11. [PMID: 37069680 PMCID: PMC10106898 DOI: 10.1186/s12989-023-00521-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 04/01/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND Interactions between air pollution and infectious agents are increasingly recognized and critical to identify, especially to protect vulnerable populations. Pregnancy represents a vulnerable period for influenza infection and air pollution exposure, yet interactions during pregnancy remain unclear. Maternal exposure to ultrafine particles (UFPs, [Formula: see text] 100 nm diameter), a class of particulate matter ubiquitous in urban environments, elicits unique pulmonary immune responses. We hypothesized that UFP exposure during pregnancy would lead to aberrant immune responses to influenza enhancing infection severity. RESULTS Building from our well-characterized C57Bl/6N mouse model employing daily gestational UFP exposure from gestational day (GD) 0.5-13.5, we carried out a pilot study wherein pregnant dams were subsequently infected with Influenza A/Puerto Rico/8/1934 (PR8) on GD14.5. Findings indicate that PR8 infection caused decreased weight gain in filtered air (FA) and UFP-exposed groups. Co-exposure to UFPs and viral infection led to pronounced elevation in PR8 viral titer and reduced pulmonary inflammation, signifying potential suppression of innate and adaptive immune defenses. Pulmonary expression of the pro-viral factor sphingosine kinase 1 (Sphk1) and pro-inflammatory cytokine interleukin-1β (IL-1 [Formula: see text]) was significantly increased in pregnant mice exposed to UFPs and infected with PR8; expression correlated with higher viral titer. CONCLUSIONS Results from our model provide initial insight into how maternal UFP exposure during pregnancy enhances respiratory viral infection risk. This model is an important first step in establishing future regulatory and clinical strategies for protecting pregnant women exposed to UFPs.
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Affiliation(s)
- Nicholas L Drury
- Department of Environmental and Occupational Health, Texas A&M University, 212 Adriance Lab Rd, 1266 TAMU, College Station, TX, 77843, USA
- Department of Nutrition, Texas A&M University, College Station, TX, 77843, USA
| | - Toriq Mustapha
- Department of Environmental and Occupational Health, Texas A&M University, 212 Adriance Lab Rd, 1266 TAMU, College Station, TX, 77843, USA
| | - Ross A Shore
- Department of Environmental and Occupational Health, Texas A&M University, 212 Adriance Lab Rd, 1266 TAMU, College Station, TX, 77843, USA
| | - Jiayun Zhao
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Gus A Wright
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, 77843, USA
| | - Aline Rodrigues Hoffmann
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, Gainesville, FL, 32653, USA
| | - Susanne U Talcott
- Department of Nutrition, Texas A&M University, College Station, TX, 77843, USA
| | - Annette Regan
- School of Nursing and Health Professions, University of San Francisco, Orange County, CA, 92868, USA
| | - Robert M Tighe
- Department of Medicine, Duke University, Durham, NC, 27710, USA
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M University, 212 Adriance Lab Rd, 1266 TAMU, College Station, TX, 77843, USA.
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5
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Lau C, Behlen JC, Myers A, Li Y, Zhao J, Harvey N, Wright G, Hoffmann AR, Zhang R, Johnson NM. In Utero Ultrafine Particulate Exposure Yields Sex- and Dose-Specific Responses to Neonatal Respiratory Syncytial Virus Infection. Environ Sci Technol 2022; 56:11527-11535. [PMID: 35926851 PMCID: PMC9386899 DOI: 10.1021/acs.est.2c02786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Exposure to particulate matter (PM) is associated with lower respiratory tract infections. The role of ultrafine particles (UFPs, ≤0.1 μm) in respiratory disease is not fully elucidated, especially in models of immunologically immature populations. To characterize the effects of maternal UFP exposure on neonatal infection, we exposed time-mated C57Bl/6n mice to filtered air or UFPs at a low dose (LD, ∼55 μg/m3) and high dose (HD, ∼275 μg/m3) throughout gestation. At 5 days of age, offspring were infected with a respiratory syncytial virus (RSV) strain known to mimic infant infection or sham control. Offspring body weights were significantly reduced in response to infection in the LD RSV group, particularly females. Pulmonary gene expression analysis demonstrated significantly increased levels of oxidative stress- and inflammation-related genes in HD-exposed male offspring in sham and RSV-infected groups. In males, the highest grade of inflammation was observed in the HD RSV group, whereas in females, the LD RSV group showed the most marked inflammation. Overall, findings highlight neonatal responses are dependent on offspring sex and maternal UFP dose. Importantly, infant RSV pathology may be enhanced following even low dose UFP exposure signifying the importance of preventing maternal exposure.
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Affiliation(s)
- Carmen Lau
- Department
of Veterinary Pathobiology, Texas A&M
University, College Station, Texas 77843, United States
| | - Jonathan C. Behlen
- Department
of Environmental and Occupational Health, Texas A&M University, College
Station, Texas 77843, United States
| | - Alexandra Myers
- Department
of Veterinary Pathobiology, Texas A&M
University, College Station, Texas 77843, United States
| | - Yixin Li
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jiayun Zhao
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Navada Harvey
- Department
of Environmental and Occupational Health, Texas A&M University, College
Station, Texas 77843, United States
| | - Gus Wright
- Department
of Veterinary Pathobiology, Texas A&M
University, College Station, Texas 77843, United States
| | - Aline Rodrigues Hoffmann
- Department
of Comparative, Diagnostic & Population Medicine, University of Florida, Gainesville, Florida 32611, United States
| | - Renyi Zhang
- Department
of Chemistry, Texas A&M University, College Station, Texas 77843, United States
- Department
of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843, United States
| | - Natalie M. Johnson
- Department
of Environmental and Occupational Health, Texas A&M University, College
Station, Texas 77843, United States
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6
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Mendoza-Sanchez I, Uwak I, Myatt L, Van Cleve A, Pulczinski JC, Rychlik KA, Sweet S, Ramani T, Zietsman J, Zamora ML, Koehler K, Carrillo G, Johnson NM. Maternal exposure to polycyclic aromatic hydrocarbons in South Texas, evaluation of silicone wristbands as personal passive samplers. J Expo Sci Environ Epidemiol 2022; 32:280-288. [PMID: 34131287 PMCID: PMC8920889 DOI: 10.1038/s41370-021-00348-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with adverse health effects in children. Valid exposure assessment methods with accurate spatial and temporal resolution across pregnancy is a critical need for advancing environmental health studies. OBJECTIVE The objective of this study was to quantify maternal PAH exposure in pregnant women residing in McAllen, Texas where the prematurity rate and childhood asthma prevalence rates are high. A secondary objective was to compare PAH levels in silicone wristbands deployed as passive samplers with concentrations measured using standardized active air-sampling techniques. METHODS Participants carried a backpack that contained air-sampling equipment (i.e., filter and XAD sorbent) and a silicone wristband (i.e., passive sampler) for three nonconsecutive 24-h periods. Filters, XAD tubes, and wristbands were analyzed for PAHs. RESULTS The median level of exposure for the sum of 16 PAHs measured via active sampling over 24 h was 5.54 ng/m3 (filters) and 43.82 ng/m3 (XADs). The median level measured in wristbands (WB) was 586.82 ng/band. Concentrations of the PAH compounds varied across sampling matrix type. Phenanthrene and fluorene were consistently measured for all participants and in all matrix types. Eight additional volatile PAHs were measured in XADs and WBs; the median level of exposure for the sum of these eight PAHs was 342.98 ng/m3 (XADs) and 632.27 ng/band. The silicone wristbands (WB) and XAD sorbents bound 1-methynaphthalyne, 2-methylnaphthalene, biphenyl following similar patterns of detection. SIGNIFICANCE Since prior studies indicate linkages between PAH exposure and adverse health outcomes in children at the PAH levels detected in our study, further investigation on the associated health effects is needed. Data reflect the ability of silicone wristbands to bind smaller molecular weight, semivolatile PAHs similar to XAD resin. Application of wristbands as passive samplers may be useful in studies evaluating semivolatile PAHs.
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Affiliation(s)
- Itza Mendoza-Sanchez
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA
| | - Inyang Uwak
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA
| | - Louise Myatt
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA
| | - Allison Van Cleve
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA
| | - Jairus C Pulczinski
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Kristal A Rychlik
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Stephen Sweet
- Geochemical and Environmental Research Group, Texas A&M University, College Station, TX, USA
| | - Tara Ramani
- Environment and Air Quality Division, Texas A&M Transportation Institute, College Station, TX, USA
| | - Josias Zietsman
- Environment and Air Quality Division, Texas A&M Transportation Institute, College Station, TX, USA
| | - Misti Levy Zamora
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Kirsten Koehler
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Genny Carrillo
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M University School of Public Health, College Station, TX, USA.
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Behlen JC, Lau CH, Pendleton D, Li Y, Hoffmann AR, Golding MC, Zhang R, Johnson NM. NRF2-Dependent Placental Effects Vary by Sex and Dose following Gestational Exposure to Ultrafine Particles. Antioxidants (Basel) 2022; 11:352. [PMID: 35204234 PMCID: PMC8868520 DOI: 10.3390/antiox11020352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 02/04/2023] Open
Abstract
Exposure to ultrafine particles (UFPs, PM0.1) during pregnancy triggers placental oxidative stress and inflammation, similar to fine PM (PM2.5). The Nrf2 gene encodes a redox-sensitive transcription factor that is a major regulator of antioxidant and anti-inflammatory responses. Disruption of NRF2 is known to substantially enhance PM2.5-driven oxidant and inflammatory responses; however, specific responses to UFP exposure, especially during critical windows of susceptibility such as pregnancy, are not fully characterized; To investigate the role of NRF2 in regulating maternal antioxidant defenses and placental responses to UFP exposure, wildtype (WT) and Nrf2-/- pregnant mice were exposed to either low dose (LD, 100 µg/m3) or high dose (HD, 500 µg/m3) UFP mixture or filtered air (FA, control) throughout gestation; Nrf2-/- HD-exposed female offspring exhibited significantly reduced fetal and placental weights. Placental morphology changes appeared most pronounced in Nrf2-/- LD-exposed offspring of both sexes. Glutathione (GSH) redox analysis revealed significant increases in the GSH/GSSG ratio (reduced/oxidized) in WT female placental tissue exposed to HD in comparison with Nrf2-/- HD-exposed mice. The expression of inflammatory cytokine genes (Il1β, Tnfα) was significantly increased in Nrf2-/- placentas from male and female offspring across all exposure groups. Genes related to bile acid metabolism and transport were differentially altered in Nrf2-/- mice across sex and exposure groups. Notably, the group with the most marked phenotypic effects (Nrf2-/- HD-exposed females) corresponded to significantly higher placental Apoa1 and Apob expression suggesting a link between placental lipid transport and NRF2 in response to high dose UFP exposure; Disruption of NRF2 exacerbates adverse developmental outcomes in response to high dose UFP exposure in female offspring. Morphological effects in placenta from male and female offspring exposed to low dose UFPs also signify the importance of NRF2 in maternal-fetal response to UFPs.
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Affiliation(s)
- Jonathan C. Behlen
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (J.C.B.); (D.P.)
| | - Carmen H. Lau
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843, USA;
| | - Drew Pendleton
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (J.C.B.); (D.P.)
| | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.L.); (R.Z.)
| | - Aline Rodrigues Hoffmann
- Department of Comparative, Diagnostic and Preventive Medicine, University of Florida, Gainesville, FL 32653, USA;
| | - Michael C. Golding
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA;
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (Y.L.); (R.Z.)
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Natalie M. Johnson
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (J.C.B.); (D.P.)
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8
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Lau CH, Pendleton D, Drury NL, Zhao J, Li Y, Zhang R, Wright GA, Hoffmann AR, Johnson NM. NRF2 Protects against Altered Pulmonary T Cell Differentiation in Neonates Following In Utero Ultrafine Particulate Matter Exposure. Antioxidants (Basel) 2022; 11:202. [PMID: 35204086 PMCID: PMC8868442 DOI: 10.3390/antiox11020202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/18/2022] Open
Abstract
Early life exposure to particulate matter (PM) air pollution negatively impacts neonatal health. The underlying mechanisms following prenatal exposure, particularly to ultrafine particles (UFP, diameter ≤ 0.1 μm), are not fully understood; To evaluate the role of Nrf2 in response to in utero UFP exposure, we exposed time-mated Nrf2-deficient (Nrf2-/-) or wildtype (WT) mice to filtered air (FA) or 100 μg/m3 ultrafine PM daily throughout pregnancy. Offspring were evaluated for pulmonary immunophenotypes and pulmonary/systemic oxidative stress on postnatal day 5, a timepoint at which we previously demonstrated viral respiratory infection susceptibility; Nrf2-/- offspring exposed to FA had significantly lower average body weights compared to FA-exposed WT pups. Moreover, PM-exposed Nrf2-/- offspring weighed significantly less than PM-exposed WT pups. Notably, PM-exposed Nrf2-/- offspring showed a decreased pulmonary Th1/Th2 ratio, indicating a Th2 bias. Th17 cells were increased in FA-exposed Nrf2-/- neonates yet decreased in PM-exposed Nrf2-/- neonates. Analysis of oxidative stress-related genes in lung and oxidative stress biomarkers in liver tissues did not vary significantly across exposure groups or genotypes. Collectively, these findings indicate that the lack of Nrf2 causes growth inhibitory effects in general and in response to gestational UFP exposure. Prenatal UFP exposure skews CD4+ T lymphocyte differentiation toward Th2 in neonates lacking Nrf2, signifying its importance in maternal exposure and infant immune responses.
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Affiliation(s)
- Carmen H. Lau
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843, USA; (C.H.L.); (G.A.W.)
| | - Drew Pendleton
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (D.P.); (N.L.D.)
| | - Nicholas L. Drury
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (D.P.); (N.L.D.)
| | - Jiayun Zhao
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (J.Z.); (Y.L.); (R.Z.)
| | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (J.Z.); (Y.L.); (R.Z.)
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843, USA; (J.Z.); (Y.L.); (R.Z.)
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Gus A. Wright
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843, USA; (C.H.L.); (G.A.W.)
- Flow Cytometry Facility, Texas A&M University, College Station, TX 77843, USA
| | - Aline Rodrigues Hoffmann
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida, Gainesville, FL 32653, USA;
| | - Natalie M. Johnson
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843, USA; (D.P.); (N.L.D.)
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9
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Behlen JC, Lau CH, Li Y, Dhagat P, Stanley JA, Rodrigues Hoffman A, Golding MC, Zhang R, Johnson NM. Gestational Exposure to Ultrafine Particles Reveals Sex- and Dose-Specific Changes in Offspring Birth Outcomes, Placental Morphology, and Gene Networks. Toxicol Sci 2021; 184:204-213. [PMID: 34609516 DOI: 10.1093/toxsci/kfab118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Particulate matter (PM) causes adverse developmental outcomes following prenatal exposure, but the underlying biological mechanisms remain uncertain. Here we elucidate the effects of diesel exhaust ultrafine particle (UFP) exposure during pregnancy on placental and fetal development. Time-mated C57Bl/6n mice were gestationally exposed to UFPs at a low dose (LD, 100 µg/m3) or high dose (HD, 500 µg/m3) for 6 h daily. Phenotypic effects on fetuses and placental morphology at gestational day (GD) of 18.5 were evaluated, and RNA sequencing was characterized for transcriptomic changes in placental tissue from male and female offspring. A significant decrease in average placental weights and crown to rump lengths was observed in female offspring in the LD exposure group. Gestational UFP exposure altered placental morphology in a dose- and sex-specific manner. Average female decidua areas were significantly greater in the LD and HD groups. Maternal lacunae mean areas were increased in the female LD group, whereas fetal blood vessel mean areas were significantly greater in the male LD and HD groups. RNA sequencing indicated several disturbed cellular functions related to lipid metabolism, which were most pronounced in the LD group and especially in female placental tissue. Our findings demonstrate the vulnerability of offspring exposed to UFPs during pregnancy, highlighting sex-specific effects and emphasizing the importance of mitigating PM exposure to prevent adverse health outcomes.
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Affiliation(s)
| | | | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Prit Dhagat
- Alabama School of Osteopathic Medicine, Dothan, Alabama 36303, USA
| | - Jone A Stanley
- Covance Laboratories, Inc., Greenfield, Indiana 46140, USA
| | | | | | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.,Department of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843, USA
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10
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Zhang R, Johnson NM, Li Y. Establishing the exposure-outcome relation between airborne particulate matter and children's health. Thorax 2021; 77:322-323. [PMID: 34429374 DOI: 10.1136/thoraxjnl-2021-217915] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2021] [Indexed: 12/17/2022]
Affiliation(s)
- Renyi Zhang
- Atmospheric Sciences and Chemistry, Texas A&M University, College Station, Texas, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health/School of Public Health, Texas A&M University, College Station, Texas, USA
| | - Yixin Li
- Chemistry, Texas A&M University, College Station, Texas, USA
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11
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Casillas GA, Johnson NM, Chiu WA, Ramirez J, McDonald TJ, Horney JA. Polycyclic Aromatic Hydrocarbons in Houston Parks After Hurricane Harvey. Environ Justice 2021; 14:277-287. [PMID: 34484557 PMCID: PMC8404169 DOI: 10.1089/env.2020.0073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Unprecedented inland precipitation and catastrophic flooding associated with Hurricane Harvey potentially redistributed contaminants from industrial sites and transportation infrastructure to recreational areas that make up networks of green infrastructure, creeks, and waterways used for flood control throughout the Greater Houston Area. Sediment samples were collected in parks located near the Buffalo Bayou watershed 1 week after Hurricane Harvey made landfall and again 7 weeks later. Total concentrations of the U.S. Environmental Protection Agency's (EPA's) 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in each sample at both time points. Diagnostic ratios were calculated to improve understanding of potential sources of PAHs after flooding. Diagnostic ratios suggest vehicular traffic to be a potential source for PAHs in parks. Although the concentrations of PAHs in all samples were below EPA actionable levels, given that no background values were available for comparison, it is difficult to quantify the impact flooding from Hurricane Harvey had on PAH concentrations in Houston parks. However, given the high frequency of flooding in Houston, and the concentration of industrial facilities and transportation infrastructure adjacent to recreation areas, these data demonstrate that PAHs were still present after unprecedented flooding. This study may also serve as a baseline for future efforts to understand the environmental health impacts of disasters.
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Affiliation(s)
- Gaston A. Casillas
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
| | - Natalie M. Johnson
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
| | - Weihsueh A. Chiu
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
| | - Juan Ramirez
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
| | - Thomas J. McDonald
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
| | - Jennifer A. Horney
- Dr. Gaston A. Casillas was formerly a doctoral student in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA, and is currently a Fellow at the Centers for Disease Control and Prevention NCEH, Atlanta, Georgia, USA. Dr. Natalie M. Johnson is Vice Chair of the Interdisciplinary Faculty in Toxicology and Associate Professor in the Department of Environmental and Occupational Health in the School of Public Health, Texas A&M University, College Station, Texas, USA. Dr. Weihsueh A. Chiu is a Professor in the Interdisciplinary Faculty in Toxicology, Texas A&M University, College Station, Texas, USA. Mr. Juan Ramirez is Environmental Laboratory Manager at TDI Brooks International, College Station, Texas, USA. Dr. Thomas J. McDonald is a Professor in the Department of Environmental and Occupational Health in the School of Public Health at Texas A&M University, College Station, Texas, USA. Dr. Jennifer A. Horney was formerly a Professor in the Department of Epidemiology and Biostatistics at Texas A&M University School of Public Health, College Station, Texas, USA, and is currently a Professor at the University of Delaware, College of Health Sciences, Newark, Delaware, USA
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12
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Johnson NM, Hoffmann AR, Behlen JC, Lau C, Pendleton D, Harvey N, Shore R, Li Y, Chen J, Tian Y, Zhang R. Air pollution and children's health-a review of adverse effects associated with prenatal exposure from fine to ultrafine particulate matter. Environ Health Prev Med 2021; 26:72. [PMID: 34253165 PMCID: PMC8274666 DOI: 10.1186/s12199-021-00995-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/01/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Particulate matter (PM), a major component of ambient air pollution, accounts for a substantial burden of diseases and fatality worldwide. Maternal exposure to PM during pregnancy is particularly harmful to children's health since this is a phase of rapid human growth and development. METHOD In this review, we synthesize the scientific evidence on adverse health outcomes in children following prenatal exposure to the smallest toxic components, fine (PM2.5) and ultrafine (PM0.1) PM. We highlight the established and emerging findings from epidemiologic studies and experimental models. RESULTS Maternal exposure to fine and ultrafine PM directly and indirectly yields numerous adverse birth outcomes and impacts on children's respiratory systems, immune status, brain development, and cardiometabolic health. The biological mechanisms underlying adverse effects include direct placental translocation of ultrafine particles, placental and systemic maternal oxidative stress and inflammation elicited by both fine and ultrafine PM, epigenetic changes, and potential endocrine effects that influence long-term health. CONCLUSION Policies to reduce maternal exposure and health consequences in children should be a high priority. PM2.5 levels are regulated, yet it is recognized that minority and low socioeconomic status groups experience disproportionate exposures. Moreover, PM0.1 levels are not routinely measured or currently regulated. Consequently, preventive strategies that inform neighborhood/regional planning and clinical/nutritional recommendations are needed to mitigate maternal exposure and ultimately protect children's health.
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Affiliation(s)
- Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA.
| | | | - Jonathan C Behlen
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA
| | - Carmen Lau
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, 77843, USA
| | - Drew Pendleton
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA
| | - Navada Harvey
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA
| | - Ross Shore
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX, 77843, USA
| | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - Jingshu Chen
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Yanan Tian
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
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13
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Uwak I, Olson N, Fuentes A, Moriarty M, Pulczinski J, Lam J, Xu X, Taylor BD, Taiwo S, Koehler K, Foster M, Chiu WA, Johnson NM. Application of the navigation guide systematic review methodology to evaluate prenatal exposure to particulate matter air pollution and infant birth weight. Environ Int 2021; 148:106378. [PMID: 33508708 PMCID: PMC7879710 DOI: 10.1016/j.envint.2021.106378] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/11/2020] [Accepted: 01/04/2021] [Indexed: 05/04/2023]
Abstract
Low birth weight is an important risk factor for many co-morbidities both in early life as well as in adulthood. Numerous studies report associations between prenatal exposure to particulate matter (PM) air pollution and low birth weight. Previous systematic reviews and meta-analyses report varying effect sizes and significant heterogeneity between studies, but did not systematically evaluate the quality of individual studies or the overall body of evidence. We conducted a new systematic review to determine how prenatal exposure to PM2.5, PM10, and coarse PM (PM2.5-10) by trimester and across pregnancy affects infant birth weight. Using the Navigation Guide methodology, we developed and applied a systematic review protocol [CRD42017058805] that included a comprehensive search of the epidemiological literature, risk of bias (ROB) determination, meta-analysis, and evidence evaluation, all using pre-established criteria. In total, 53 studies met our inclusion criteria, which included evaluation of birth weight as a continuous variable. For PM2.5 and PM10, we restricted meta-analyses to studies determined overall as "low" or "probably low" ROB; none of the studies evaluating coarse PM were rated as "low" or "probably low" risk of bias, so all studies were used. For PM2.5, we observed that for every 10 µg/m3 increase in exposure to PM2.5 in the 2nd or 3rd trimester, respectively, there was an associated 5.69 g decrease (I2: 68%, 95% CI: -10.58, -0.79) or 10.67 g decrease in birth weight (I2: 84%, 95% CI: -20.91, -0.43). Over the entire pregnancy, for every 10 µg/m3 increase in PM2.5 exposure, there was an associated 27.55 g decrease in birth weight (I2: 94%, 95% CI: -48.45, -6.65). However, the quality of evidence for PM2.5 was rated as "low" due to imprecision and/or unexplained heterogeneity among different studies. For PM10, we observed that for every 10 µg/m3 increase in exposure in the 3rd trimester or the entire pregnancy, there was a 6.57 g decrease (I2: 0%, 95% CI: -10.66, -2.48) or 8.65 g decrease in birth weight (I2: 84%, 95% CI: -16.83, -0.48), respectively. The quality of evidence for PM10 was rated as "moderate," as heterogeneity was either absent or could be explained. The quality of evidence for coarse PM was rated as very low/low (for risk of bias and imprecision). Overall, while evidence for PM2.5 and course PM was inadequate primarily due to heterogeneity and risk of bias, respectively, our results support the existence of an inverse association between prenatal PM10 exposure and low birth weight.
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Affiliation(s)
- Inyang Uwak
- Department of Environmental and Occupational Health. Texas A&M University, College Station, TX, USA
| | - Natalie Olson
- Department of Veterinary Integrative Biosciences. Texas A&M University, College Station, TX, USA
| | - Angelica Fuentes
- Department of Veterinary Integrative Biosciences. Texas A&M University, College Station, TX, USA
| | - Megan Moriarty
- Department of Environmental and Occupational Health. Texas A&M University, College Station, TX, USA
| | - Jairus Pulczinski
- Department of Environmental Health and Engineering. Johns Hopkins University, Baltimore, MD, USA
| | - Juleen Lam
- Department of Health Sciences, California State University, East Bay, Hayward, CA USA
| | - Xiaohui Xu
- Department of Epidemiology and Biostatistics. Texas A&M University, College Station, TX, USA
| | - Brandie D Taylor
- Department of Epidemiology and Biostatistics. Temple University, Philadelphia, PA, USA
| | - Samuel Taiwo
- Department of Environmental and Occupational Health. Texas A&M University, College Station, TX, USA
| | - Kirsten Koehler
- Department of Environmental Health and Engineering. Johns Hopkins University, Baltimore, MD, USA
| | - Margaret Foster
- Medical Sciences Library. Texas A&M University, College Station, TX, USA
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences. Texas A&M University, College Station, TX, USA
| | - Natalie M Johnson
- Department of Environmental and Occupational Health. Texas A&M University, College Station, TX, USA.
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14
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Mustapha TA, Chang RC, Garcia-Rhodes D, Pendleton D, Johnson NM, Golding MC. Gestational exposure to particulate air pollution exacerbates the growth phenotypes induced by preconception paternal alcohol use: a multiplex model of exposure. Environ Epigenet 2020; 6:dvaa011. [PMID: 33214907 PMCID: PMC7660119 DOI: 10.1093/eep/dvaa011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/30/2020] [Accepted: 06/09/2020] [Indexed: 05/11/2023]
Abstract
It is now clear that parental histories of drug use, toxicant exposure, and social stress all have a significant influence on the health and development of the next generation. However, the ability of epigenetic parental life memories to interact with subsequent gestational exposures and cumulatively modify the developmental trajectory of the offspring remains an unexplored perspective in toxicology. Studies from our laboratory have identified male-specific postnatal growth restriction in a mouse model of chronic, preconception paternal alcohol exposure. The goal of the current study was to determine if paternal alcohol use, before conception, could modify the susceptibility of the offspring to a completely separate exposure encountered by the mother during pregnancy. In independent experiments, we previously identified altered developmental programming and increased markers of severe asthma induced by gestational exposure to particulate air pollution. In this study, male mice were exposed to either the control or alcohol preconception treatments, then mated to naive females, which we subsequently exposed to an ultrafine mixture of particulate matter via inhalation. Individually, neither preconception paternal drinking nor gestational exposures to particulate air pollution impacted the postnatal growth of female offspring. However, when both exposures were combined, females displayed a 30% reduction in weight gain. Unexpectedly, this exposure paradigm resulted in a dramatic postnatal increase in litter loss due to maternal cannibalism, which prevented additional measures of offspring health. These preliminary studies provide evidence of a complex interplay between preconception life history and intrauterine environmental factors in the control of postnatal growth.
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Affiliation(s)
- Toriq A Mustapha
- Environmental and Occupational Health, Texas A&M School of Public Health, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843-1266, USA
| | - Richard C Chang
- Department of Veterinary Physiology & Pharmacology College of Veterinary Medicine and Biomedical Sciences Texas A&M University 588 Raymond Stotzer Pw, 4466 TAMU, College Station Texas, 77843, USA
| | - Dennis Garcia-Rhodes
- Environmental and Occupational Health, Texas A&M School of Public Health, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843-1266, USA
| | - Drew Pendleton
- Environmental and Occupational Health, Texas A&M School of Public Health, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843-1266, USA
| | - Natalie M Johnson
- Environmental and Occupational Health, Texas A&M School of Public Health, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843-1266, USA
| | - Michael C Golding
- Department of Veterinary Physiology & Pharmacology College of Veterinary Medicine and Biomedical Sciences Texas A&M University 588 Raymond Stotzer Pw, 4466 TAMU, College Station Texas, 77843, USA
- Correspondence address. Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, 4466 TAMU, College Station, TX 77843-4466, USA. Tel: +1-979-862-1332; Fax: +1-979-845-6544, E-mail:
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15
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Livingstone MC, Johnson NM, Roebuck BD, Kensler TW, Groopman JD. Serum miR-182 is a predictive biomarker for dichotomization of risk of hepatocellular carcinoma in rats. Mol Carcinog 2019; 58:2017-2025. [PMID: 31373075 DOI: 10.1002/mc.23093] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/13/2019] [Accepted: 07/23/2019] [Indexed: 12/11/2022]
Abstract
Exploration of animal models leads to discoveries that can reveal candidate biomarkers for translation to human populations. Herein, a model of hepatocarcinogenesis and protection was used in which rats treated with aflatoxin (AFB1 ) daily for 28 days (200 µg/kg BW) developed tumors compared with rats completely protected from tumors by concurrent administration of the chemoprotective agent, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im). Differential expression of miRNAs in tumors (AFB1 ) and nontumor (AFB1 + CDDO-Im) bearing livers and their levels in sera over the life-course of the animals was determined. miRNA transcriptome analysis identified 17 miRNAs significantly upregulated at greater than five-fold in the tumors. The ten most dysregulated miRNAs judged by fold-change and biological significance were selected for further study, including liver-specific miR-122-5p. Validation of sequencing results by real-time PCR confirmed the upregulation of the majority of these miRNAs in tumors, including miR-182, as well as miR-224-5p as the most dysregulated of these miRNAs (over 400-fold). The longitudinal analysis of levels of miR-182 in sera demonstrated significant and persistent increases (5.13-fold; 95% CI: 4.59-5.70). The increase in miR-182 was detected months before any clinical symptoms were present in the animals. By the terminal time point of the study, in addition to elevated levels of serum miR-182, serum miR-122-5p was also found to be increased (>1.5-fold) in animals that developed hepatocarcinomas. Thus, using the data from an unbiased discovery approach of the tissue findings, serum miR-182 was found to track across the complex, multistage process of hepatocarcinogenesis opening an opportunity for translation to human populations.
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Affiliation(s)
- Merricka C Livingstone
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M School of Public Health, College Station, Texas
| | - Bill D Roebuck
- Department of Pharmacology and Toxicology, Giesel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Thomas W Kensler
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - John D Groopman
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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16
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Rychlik KA, Secrest JR, Lau C, Pulczinski J, Zamora ML, Leal J, Langley R, Myatt LG, Raju M, Chang RCA, Li Y, Golding MC, Rodrigues-Hoffmann A, Molina MJ, Zhang R, Johnson NM. In utero ultrafine particulate matter exposure causes offspring pulmonary immunosuppression. Proc Natl Acad Sci U S A 2019; 116:3443-3448. [PMID: 30808738 PMCID: PMC6397543 DOI: 10.1073/pnas.1816103116] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Early life exposure to fine particulate matter (PM) in air is associated with infant respiratory disease and childhood asthma, but limited epidemiological data exist concerning the impacts of ultrafine particles (UFPs) on the etiology of childhood respiratory disease. Specifically, the role of UFPs in amplifying Th2- and/or Th17-driven inflammation (asthma promotion) or suppressing effector T cells (increased susceptibility to respiratory infection) remains unclear. Using a mouse model of in utero UFP exposure, we determined early immunological responses to house dust mite (HDM) allergen in offspring challenged from 0 to 4 wk of age. Two mice strains were exposed throughout gestation: C57BL/6 (sensitive to oxidative stress) and BALB/C (sensitive to allergen exposure). Offspring exposed to UFPs in utero exhibited reduced inflammatory response to HDM. Compared with filtered air (FA)-exposed/HDM-challenged mice, UFP-exposed offspring had lower white blood cell counts in bronchoalveolar lavage fluid and less pronounced peribronchiolar inflammation in both strains, albeit more apparent in C57BL/6 mice. In the C57BL/6 strain, offspring exposed in utero to FA and challenged with HDM exhibited a robust response in inflammatory cytokines IL-13 and Il-17. In contrast, this response was lost in offspring exposed in utero to UFPs. Circulating IL-10 was significantly up-regulated in C57BL/6 offspring exposed to UFPs, suggesting increased regulatory T cell expression and suppressed Th2/Th17 response. Our results reveal that in utero UFP exposure at a level close to the WHO recommended PM guideline suppresses an early immune response to HDM allergen, likely predisposing neonates to respiratory infection and altering long-term pulmonary health.
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Affiliation(s)
- Kristal A Rychlik
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843
| | - Jeremiah R Secrest
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Carmen Lau
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843
| | - Jairus Pulczinski
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843
| | - Misti L Zamora
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843
| | - Jeann Leal
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843
| | - Rebecca Langley
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843
| | - Louise G Myatt
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843
| | - Muppala Raju
- Department of Epidemiology and Biostatistics, Texas A&M University, College Station, TX 77843
| | - Richard C-A Chang
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Michael C Golding
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | | | - Mario J Molina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843
| | - Natalie M Johnson
- Department of Environmental and Occupational Health, Texas A&M University, College Station, TX 77843;
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Wang M, Hearon SE, Johnson NM, Phillips TD. Development of broad-acting clays for the tight adsorption of benzo[a]pyrene and aldicarb. Appl Clay Sci 2019; 168:196-202. [PMID: 31435120 PMCID: PMC6703832 DOI: 10.1016/j.clay.2018.11.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
People and animals can be unintentionally exposed to complex mixtures of hazardous chemicals that can threaten the safety of food and water supplies following natural and man-made disasters and emergencies. Our research has focused on the development of broad-acting adsorbents that will tightly bind environmental contaminants in the gastrointestinal tract and decrease their bioavailability to humans and animals during these events. In this study, benzo[a]pyrene (BaP) and aldicarb were used as representative chemicals due to their high toxicity and extensive distribution in the environment. Both chemicals have been commonly detected in water and sediments in the US, and their distribution and concentrations can be enhanced during disasters. To address this problem, we have amended and functionalized montmorillonite clays with the nutrients, L-carnitine and choline to enhance their attraction for lipophilic toxins, such as BaP and aldicarb. Based on equilibrium isothermal analyses, we have demonstrated a significantly increased binding capacity (Qmax) and affinity (Kd) for BaP and aldicarb compared to the parent clay. Adsorption isotherms also showed that talc bound strongly to BaP with the highest Qmax, which was twice that of activated carbon. Additionally, cultures of adult hydra with a metabolism activation package were used as an in vivo toxicity indicator to confirm the ability of test adsorbents to protect against toxicity at low inclusion levels. We anticipate that the optimal adsorbents developed can be delivered in food and flavored water, or administered by sachet or capsule during emergencies and disasters to decrease human and animals exposures to environmental toxins.
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Affiliation(s)
- Meichen Wang
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Sara E. Hearon
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Natalie M. Johnson
- Environmental and Occupational Health, School of Public Health, Texas A&M University, College Station, TX 77843, USA
| | - Timothy D. Phillips
- Veterinary Integrative Biosciences Department, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
- Corresponding author.
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Livingstone MC, Johnson NM, Roebuck BD, Kensler TW, Groopman JD. Profound changes in miRNA expression during cancer initiation by aflatoxin B 1 and their abrogation by the chemopreventive triterpenoid CDDO-Im. Mol Carcinog 2017; 56:2382-2390. [PMID: 28218475 DOI: 10.1002/mc.22635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/01/2017] [Accepted: 02/16/2017] [Indexed: 12/17/2022]
Abstract
Aflatoxin B1 (AFB1 ) is a potent human and animal hepatocarcinogen. To investigate the effects of aflatoxin on miRNA expression during the initiation phase of carcinogenesis, next-generation sequencing was used to analyze liver tissues from F344 rats exposed to 200 μg/kg per day AFB1 for 4 week. A panel of miRNAs was identified that was upregulated with AFB1 treatment compared to controls: rno-miR-434-3p, rno-miR-411-5p, rno-miR-221-3p, rno-miR-127-3p, rno-miR-205, rno-miR-429, rno-miR-34a-5p, rno-miR-181c-3p, rno-miR-200b-3p, and rno-miR-541-5p. Analysis of rat livers exposed to AFB1 plus the chemopreventive triterpenoid CDDO-Im revealed a striking abrogation of this upregulation. These changes were validated by real-time PCR. We also explored the temporal variation in expression of the candidate miRNAs during the 4-week dosing period. Most of the candidate miRNAs were upregulated at week 1 and increased for the duration of AFB1 dosing over the 4-week period. Treatment with CDDO-Im ameliorated these effects at all time points. All candidate miRNAs were detectable in serum from aflatoxin treated animals; however, there was no significant difference in expression for 7 of the 11 miRNAs examined. Exposure to AFB1 upregulated miR-122-5p (fivefold), 34a-5p (13-fold), and 181c-3p (170-fold) compared with controls. The findings from this study give insight into epigenetic changes induced by aflatoxin taking place during the initial step of carcinogenesis.
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Affiliation(s)
| | | | - Bill D Roebuck
- Dartmouth College School of Medicine, Hanover, New Hampshire
| | - Thomas W Kensler
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - John D Groopman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Livingstone MC, Roebuck BD, Johnson NM, Kensler TW, Groopman JD. Abstract 4448: Elevated levels of circulating miR-34a-5p and miR-181c-3p during cancer initiation by aflatoxin B1. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-4448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
MicroRNAs are small non-coding RNAs that affect gene expression. They are essential in normal physiological processes and have been implicated in carcinogenesis. Hepatocellular carcinoma (HCC) is the second leading cause of cancer death globally, with the risk factor aflatoxin (AFB1) estimated to play a causal role in up to 28% of all HCC cases. In this study, we analyzed circulating miRNAs in a quantitative rat cancer model that were previously found to be associated with AFB1 exposure in liver. Sera were examined from 3 groups of animals: rats dosed with AFB1 (200 µg) for 28 consecutive days receiving vehicle only or AFB1 plus the chemopreventive agent CDDO-Im (30 µmol), and controls (Johnson et al., CaPR, 2014). Small RNAs were isolated from these serum samples at the end of the dosing period and analyzed by RT-qPCR. Quantitative PCR results at the end of the carcinogenic 28-day dosing regimen revealed notable increased expression of miR-34a-5p and miR-181c-3p (13 fold and 170 fold, respectively) in the AFB1 treated samples compared to controls. This expression was reduced in animals that received complete protection from developing HCC by concurrent intervention with CDDO-Im. Additionally, miR-122-5p displayed increased expression (5 fold) and miR-541-5p was downregulated (0.08 fold) in the sera of AFB1-treated animals. Overall, the data suggest that serum expression of miR-34a-5p and 181c-3p during liver cancer initiation could give insight into increased risk of developing HCC. Supported by T32ES007141-31A1 and CA197222.
Citation Format: Merricka C. Livingstone, Bill D. Roebuck, Natalie M. Johnson, Thomas W. Kensler, John D. Groopman. Elevated levels of circulating miR-34a-5p and miR-181c-3p during cancer initiation by aflatoxin B1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4448. doi:10.1158/1538-7445.AM2017-4448
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Affiliation(s)
| | | | | | | | - John D. Groopman
- 1Johns Hopkins University School of Public Health, Baltimore, MD
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Livingstone MC, Roebuck BD, Johnson NM, Kensler TW, Groopman JD. Abstract 1083: Temporal trends in microRNAs during subchronic aflatoxin dosing and modulation by the chemopreventive oleane triterpenoid, CDDO-Im. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-1083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Liver cancer is the second leading cause of cancer death worldwide: risk factors include the viruses, HBV and HCV, and the environmental carcinogen aflatoxin B1 (AFB1). Chemoprevention strategies that activate genes controlled by the KEAP1-NRF2 pathway, such as CDDO-Im, afford complete protection against AFB1-induced hepatocarcinogenesis in rats. The opportunity to deploy these types of agents in high-risk populations would be advanced by the validation of biomarkers reflecting their efficacy. MicroRNAs (miRNAs) affecting gene expression are important in normal physiology and have been shown to be frequently dysregulated in cancer. It is our hypothesis that specific rat liver miRNAs are biomarkers that temporally track with AFB1-induced liver cancer, and are modulated in animals that receive complete protection by CDDO-Im.
MiRNAs were isolated from archived liver tissue of rats (Johnson et al., CaPR, 2014) that were dosed with AFB1 (200 μg) for 28 consecutive days. Two additional groups received either vehicle only or AFB1 + CDDO-Im (30 μmol). After RNA isolation (miRCURY tissue, Exiqon), samples were profiled by RNA sequencing (Illumina). Fourteen miRNAs were selected based on dynamic range and level of detection for validation by RT-qPCR (TaqMan microRNA assay).
MiRNA profiling from animals at the end of the carcinogenic 28-day dosing regimen revealed an increased total number of miRNAs due to AFB1 exposure alone (n≈500) compared to control. Those miRNAs displaying a greater than 10 fold increase in expression between control and AFB1 treatment groups were examined in detail: 541-5p, 34a-5p, 127-3p, 205, 434-3p, 429, 411-5p, 181c-3p, 200b-3p, 221-3p. RNA-seq data showed that these were all upregulated in the AFB1-treated samples. Co-treatment with CDDO-Im shifted expression levels back to control. The miRNAs 192-3p, 92a-3p, 26b-3p, and 375-3p were expressed consistently in all treatment groups and were selected for normalization. Expression levels of the 14 candidate miRNAs were then examined in liver samples obtained from rats after 7, 14 and 21 doses AFB1 and compared to levels determined at week 4 (28 doses AFB1). Quantitative analysis demonstrated an increase in expression of the panel of miRNAs due to AFB1 exposure over the dosing period, potentially indicating a role in early carcinogenesis. MicroRNA expression showed a varying trend over time in animals treated with AFB1 plus CDDO-Im. Three invariant miRNAs (miR-375-3p, 92a-3p, 192-3p) showed little change during the 28-day exposure period.
In conclusion, we have identified a panel of miRNAs that are upregulated and track with AFB1 exposure. These changes are abrogated by treatment with CDDO-Im and thus reflect the protective efficacy of the intervention. Supported by T32ES007141-31A1 and CA197222.
Citation Format: Merricka C. Livingstone, Bill D. Roebuck, Natalie M. Johnson, Thomas W. Kensler, John D. Groopman. Temporal trends in microRNAs during subchronic aflatoxin dosing and modulation by the chemopreventive oleane triterpenoid, CDDO-Im. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1083.
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Affiliation(s)
| | | | | | | | - John D. Groopman
- 1Johns Hopkins University School of Public Health, Baltimore, MD
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Kensler KH, Slocum SL, Chartoumpekis DV, Dolan PM, Johnson NM, Ilic Z, Crawford DR, Sell S, Groopman JD, Kensler TW, Egner PA. Genetic or pharmacologic activation of Nrf2 signaling fails to protect against aflatoxin genotoxicity in hypersensitive GSTA3 knockout mice. Toxicol Sci 2014; 139:293-300. [PMID: 24675090 DOI: 10.1093/toxsci/kfu056] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Mice are resistant to aflatoxin hepatotoxicity, primarily due to high expression of glutathione S-transferases (GSTs), and in particular the GSTA3 subunit. Nuclear factor erythroid 2 related factor 2 (Nrf2) signaling, which controls a broad-based cytoprotective response, was activated either genetically or pharmacologically in an attempt to rescue GSTA3 knockout mice from aflatoxin genotoxicity. Genetic activation of Nrf2 signaling was attained in a GSTA3: hepatocyte-specific Keap1 double knockout (DKO) mouse whereas pharmacologic activation of Nrf2 was achieved through pretreatment of mice with the triterpenoid 1-[2-cyano-3-,12-dioxoleana-1,9(11)-dien-28-oyl] imidazole (CDDO-Im) prior to aflatoxin B1 exposure. Following oral treatment with aflatoxin, urine was collected from mice for 24 h and hepatic and urinary aflatoxin metabolites then quantified using isotope dilution-mass spectrometry. Although Nrf2 was successfully activated genetically and pharmacologically, neither means affected the response of GSTA3 knockout mice to chemical insult with aflatoxin. Hepatic aflatoxin B1-N(7)-guanine levels were elevated 120-fold in GSTA3 knockout mice compared with wild-type and levels were not attenuated by the interventions. This lack of effect was mirrored in the urinary excretion of aflatoxin B1-N(7)-guanine. By contrast, urinary excretion of aflatoxin B1-N-acetylcysteine was >200-fold higher in wild-type mice compared with the single GSTA3 knockout or DKO mouse. The inability to rescue GSTA3 knockout mice from aflatoxin genotoxicity through the Nrf2 transcriptional program indicates that Gsta3 is unilaterally responsible for the detoxication of aflatoxin in mice.
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Affiliation(s)
- Kevin H Kensler
- Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, Maryland 21205
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Johnson NM, Egner PA, Baxter VK, Sporn MB, Wible RS, Sutter TR, Groopman JD, Kensler TW, Roebuck BD. Complete protection against aflatoxin B(1)-induced liver cancer with a triterpenoid: DNA adduct dosimetry, molecular signature, and genotoxicity threshold. Cancer Prev Res (Phila) 2014; 7:658-65. [PMID: 24662598 DOI: 10.1158/1940-6207.capr-13-0430] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In experimental animals and humans, aflatoxin B1 (AFB1) is a potent hepatic toxin and carcinogen. The synthetic oleanane triterpenoid 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im), a powerful activator of Keap1-Nrf2 signaling, protects against AFB1-induced toxicity and preneoplastic lesion formation (GST-P-positive foci). This study assessed and mechanistically characterized the chemoprotective efficacy of CDDO-Im against AFB1-induced hepatocellular carcinoma (HCC). A lifetime cancer bioassay was undertaken in F344 rats dosed with AFB1 (200 μg/kg rat/day) for four weeks and receiving either vehicle or CDDO-Im (three times weekly), one week before and throughout the exposure period. Weekly, 24-hour urine samples were collected for analysis of AFB1 metabolites. In a subset of rats, livers were analyzed for GST-P foci. The comparative response of a toxicogenomic RNA expression signature for AFB1 was examined. CDDO-Im completely protected (0/20) against AFB1-induced liver cancer compared with a 96% incidence (22/23) observed in the AFB1 group. With CDDO-Im treatment, integrated level of urinary AFB1-N(7)-guanine was significantly reduced (66%) and aflatoxin-N-acetylcysteine, a detoxication product, was consistently elevated (300%) after the first AFB1 dose. In AFB1-treated rats, the hepatic burden of GST-P-positive foci increased substantially (0%-13.8%) over the four weeks, but was largely absent with CDDO-Im intervention. The toxicogenomic RNA expression signature characteristic of AFB1 was absent in the AFB1 + CDDO-Im-treated rats. The remarkable efficacy of CDDO-Im as an anticarcinogen is established even in the face of a significant aflatoxin adduct burden. Consequently, the absence of cancer requires a concept of a threshold for DNA damage for cancer development.
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Affiliation(s)
- Natalie M Johnson
- Authors' Affiliations: Department of Environmental Health Sciences, Bloomberg School of Public Health
| | - Patricia A Egner
- Authors' Affiliations: Department of Environmental Health Sciences, Bloomberg School of Public Health
| | - Victoria K Baxter
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Michael B Sporn
- Department of Pharmacology and Toxicology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire
| | - Ryan S Wible
- W. Harry Feinstone Center for Genomic Research, University of Memphis, Memphis, Tennessee; and
| | - Thomas R Sutter
- W. Harry Feinstone Center for Genomic Research, University of Memphis, Memphis, Tennessee; and
| | - John D Groopman
- Authors' Affiliations: Department of Environmental Health Sciences, Bloomberg School of Public Health
| | - Thomas W Kensler
- Authors' Affiliations: Department of Environmental Health Sciences, Bloomberg School of Public Health; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bill D Roebuck
- Department of Pharmacology and Toxicology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire;
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Mitchell NJ, Kumi J, Johnson NM, Dotse E, Marroquin-Cardona A, Wang JS, Jolly PE, Ankrah NA, Phillips TD. Reduction in the urinary aflatoxin M1 biomarker as an early indicator of the efficacy of dietary interventions to reduce exposure to aflatoxins. Biomarkers 2013; 18:391-8. [PMID: 23697800 DOI: 10.3109/1354750x.2013.798031] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Aflatoxin B1 is a persistent public health issue in Ghana. Assessment of AFB1 intervention efficacy is currently dependent on long-term biomarkers. This study was designed to determine whether daily AFM1 biomarker levels could be utilized as an early detection method for intervention efficacy. Participants were treated with a refined calcium montmorillonite clay (UPSN) or a placebo (calcium carbonate) in a crossover study. Urine samples were assessed for AFM1 levels daily. UPSN treatment reduced AFM1 biomarkers by 55% compared to the placebo. This is the first study to show that daily urinary AFM1 levels can be used as a biomarker of internal aflatoxin B1 exposure in short-term intervention trials to determine efficacy.
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Affiliation(s)
- Nicole J Mitchell
- College of Veterinary Medicine, Texas A&M University, College Station, TX 77843-4458, USA
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Johnson NM, Qian G, Xu L, Tietze D, Marroquin-Cardona A, Robinson A, Rodriguez M, Kaufman L, Cunningham K, Wittmer J, Guerra F, Donnelly KC, Williams JH, Wang JS, Phillips TD. Aflatoxin and PAH exposure biomarkers in a U.S. population with a high incidence of hepatocellular carcinoma. Sci Total Environ 2010; 408:6027-31. [PMID: 20870273 PMCID: PMC2993492 DOI: 10.1016/j.scitotenv.2010.09.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/26/2010] [Accepted: 09/03/2010] [Indexed: 05/23/2023]
Abstract
The incidence of hepatocellular carcinoma (HCC) is significantly elevated in a Hispanic community in Bexar County, Texas. Chronic exposure to dietary aflatoxins (AFs) is a major risk factor for HCC; increased risk has been linked to polycyclic aromatic hydrocarbon (PAH) co-exposure and hepatitis virus infection. The aims of this study were to assess AF and PAH exposures, investigate dietary factors that may contribute to increased AF exposure, and determine the prevalence of hepatitis virus infection in Bexar Co. Blood and urine samples were collected from 184 volunteers for biomarker analyses and hepatitis screening. Serum AFB(1)-lysine adduct, urinary AFM(1) and 1-hydroxypyrene (1-OHP) levels were measured using high-performance liquid chromatography. The average AFB(1)-lysine adduct level detected in 20.6% of serums was 3.84 ± 3.11 pg/mg albumin (range 1.01-16.57 pg/mg). AFM(1) was detected in 11.7% of urines, averaging 223.85 ± 250.56 pg/mg creatinine (range 1.89-935.49 pg/mg). AFM(1) detection was associated with increased consumption of corn tortillas (p=0.009), nuts (p=0.033) and rice (p=0.037). A significant difference was observed between mean 1-OHP values of non-smokers (0.07 ± 0.13) and smokers (0.80 ± 0.68) μmol/mol creatinine (p<0.01). A high hepatitis C virus positivity rate (7.1%) was observed. Findings suggest that the incidence and level of AF and PAH exposure were less than those observed in a high-risk population; however, participants consuming higher amounts of foods prone to AF contamination may be more vulnerable to exposure and interactions with other environmental/biological factors (i.e., HCV).
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Affiliation(s)
- Natalie M Johnson
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, 4458 TAMU, College Station, TX 77843, USA
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Abstract
The neutralization of strong acids from precipitation is largely accomplished (75 percent) in the soil zone by rapid reaction with basic aluminum salts and biologic matter. On a regional basis, acidified and aluminum-rich lakes and streams in New England are confined mainly to low-order watersheds.
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Williams JH, Grubb JA, Davis JW, Wang JS, Jolly PE, Ankrah NA, Ellis WO, Afriyie-Gyawu E, Johnson NM, Robinson AG, Phillips TD. HIV and hepatocellular and esophageal carcinomas related to consumption of mycotoxin-prone foods in sub-Saharan Africa. Am J Clin Nutr 2010; 92:154-60. [PMID: 20484447 DOI: 10.3945/ajcn.2009.28761] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Promotion of the HIV epidemic by aflatoxin is postulated but not yet established. Sub-Saharan populations commonly consume food contaminated by mycotoxins, particularly aflatoxins (predominantly found in peanut, maize, rice, and cassava) and fumonisins, which occur primarily in maize. Aflatoxin promotes hepatocellular cancer, and fumonisin may promote esophageal cancer. OBJECTIVES This analysis was undertaken to test the hypotheses that consumption of mycotoxin-prone staple foods is 1) related to the incidence of HIV infection in Africa and 2) related to "signature" cancer rates confirming exposure to aflatoxins and fumonisins. DESIGN World Health Organization data for causes of death and the Food and Agriculture Organization per capita consumption data for commodities in sub-Saharan Africa were used. Per capita Gross Domestic Product and the percentage of Muslims (%Muslim) were the socioeconomic data sets exploited. Relations between causes of mortality, consumption of mycotoxin-prone foods, and socioeconomic variables were evaluated. Models for HIV transmission as a function of maize consumption and %Muslim were estimated. RESULTS HIV and esophageal cancer deaths were significantly related to maize but were inversely related to %Muslim and rice consumption. HIV infections were minimized (74 compared with 435/100,000 people; odds ratio: 2.41; 95% CI: 1.73, 3.24; P < or = 0.0001) by the combination of low maize consumption and above-median % Muslim. Hepatocellular cancer deaths were positively related to rice but negatively related to maize consumption. CONCLUSIONS HIV transmission frequency is positively associated with maize consumption in Africa. The relation between cancer and food suggests that fumonisin contamination rather than aflatoxin is the most likely factor in maize promoting HIV. Changes to the quality of maize may avoid up to 1,000,000 transmissions of HIV annually.
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Marroquín-Cardona A, Deng Y, Taylor JF, Hallmark CT, Johnson NM, Phillips TD. In vitro and in vivo characterization of mycotoxin-binding additives used for animal feeds in Mexico. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2010; 26:733-43. [PMID: 19680945 DOI: 10.1080/02652030802641872] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The study was conducted to characterize and compare twelve different additives distributed in Mexico as mycotoxin binders utilizing: (1) equilibrium isothermal analysis for aflatoxin B(1) (AFB(1)) adsorption, (2) a variety of mineralogical probes, and (3) Hydra toxicity bioassay. The test additives Milbond-TX (MLB), Mycoad (MCA), Volclay FD181 (VOL), Fixat (FXT), Toxinor (TOX), Mexsil (MEX), Mycosil (MYC), Klinsil (KLS), Zeotek (ZEO), Duotek (DUO), Mycosorb (MSB), and Mycofix Plus 3.0 (MIX) were compared with NovaSil Plus (NSP). Isotherms for AFB(1) adsorption were conducted at pH 2 and pH 6.5, mimicking pH conditions in the stomach and small intestine. Mineralogical analysis included determination of swelling volume, X-ray diffraction analysis, and fractionation procedures. A Hydra vulgaris toxicity study was performed to evaluate the potential safety of the additives. Computer-generated isotherm data were fit using the Langmuir model, and parameters of Q(max) and K(d) were estimated. The most effective additives for AFB(1) at both pH conditions were NSP, MLB, MCA and VOL, while the least effective was MSB. The amounts of sand, silt and clay fractions varied among the additives. Nine of the additives showed the presence of smectite. Most of the additives were found to be non-toxic to Hydra except for the organoclays (ZEO, DUO) and MSB. In general, NSP demonstrated the highest sorption capacity in the bulk material and the different fractions. Studies to characterize these binding additives further and to evaluate their multiple mycotoxin sorption claims are ongoing.
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Johnson NM, Afriyie-Gyawu E, Huebner H, Marroquin-Cardona A, Robinson A, Tang L, Xu L, Ankrah NA, Ofori-Adjei D, Jolly PE, Williams JH, Wang JS, Phillips TD. PAH exposure in a Ghanaian population at high risk for aflatoxicosis. Sci Total Environ 2009; 407:1886-1891. [PMID: 19144392 DOI: 10.1016/j.scitotenv.2008.11.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/21/2008] [Accepted: 11/25/2008] [Indexed: 05/27/2023]
Abstract
It was postulated that a population in sub-Saharan Africa, known to be at high risk for aflatoxicosis due to frequent ingestion of aflatoxin (AF)-contaminated foods could also be exposed to polycyclic aromatic hydrocarbons (PAHs) from a variety of environmental sources. Previously, participants in this population were shown to be highly exposed to AFs, and this exposure was significantly reduced by intervention with NovaSil clay (NS). Objectives of this study were 1) to assess PAH exposure in participants from the AF study using urinary biomarker 1-hydroxypyrene (1-OHP); 2) examine the effect of NS clay and placebo (cellulose) treatment on 1-OHP levels; and 3) determine potential association(s) between AF and PAH exposures. A clinical trial was conducted in 177 Ghanaians who received either NS capsules as high dose or low dose, or placebo (cellulose) for a period of 3 months. At the start and end of the study, urine samples were analyzed for 1-OHP. Of the 279 total samples, 98.9% had detectable levels of 1-OHP. Median 1-OHP excretion in nonsmokers was 0.64 micromol/mol creatinine at baseline and 0.69 micromol/mol creatinine after 3 months. Samples collected at both time points did not show significant differences between placebo and NS-treated groups. There was no linear correlation between 1-OHP and AF-albumin adduct levels. Results show that this population is highly exposed to PAHs (and AFs), that NS and cellulose treatment had no statistically significant effect on 1-OHP levels, and that this urinary biomarker was not linearly related with AF exposure.
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Affiliation(s)
- Natalie M Johnson
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
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Wang P, Afriyie-Gyawu E, Tang Y, Johnson NM, Xu L, Tang L, Huebner HJ, Ankrah NA, Ofori-Adjei D, Ellis W, Jolly PE, Williams JH, Wang JS, Phillips TD. NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis: II. Reduction in biomarkers of aflatoxin exposure in blood and urine. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2008; 25:622-34. [PMID: 18478481 DOI: 10.1080/02652030701598694] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The efficacy of NovaSil clay (NS) to reduce aflatoxin (AF) biomarkers of exposure was evaluated in 656 blood samples and 624 urine samples collected from study participants during a 3-month phase IIa clinical intervention trial in Ghana. NS was delivered before meals via capsules. Serum AFB (1)-albumin adduct was measured by radioimmunoassay and urinary AFM (1) metabolites were quantified by immunoaffinity-high-performance liquid chromatography (HPLC)-fluorescence methods. Levels of AFB (1) -albumin adduct in serum samples collected at baseline and at 1 month were similar (p = 0.2354 and p = 0.3645, respectively) among the placebo (PL), low dose (LD, 1.5 g NS day (-1)), and high dose (HD, 3.0 g NS day (-1)) groups. However, the levels of AFB (1)-albumin adduct at 3 months were significantly decreased in both the LD group (p < 0.0001) and the HD group (p < 0.0001) compared with levels in the PL group. Levels of AFM(1) in urine samples collected at baseline and at 1 month were not statistically different among the three study groups. However, a significant decrease (up to 58%) in the median level of AFM (1) in samples collected at 3 months was found in the HD group when compared with the median level in the PL group (p < 0.0391). In addition, significant effects were found for dose, time, and dose-time interaction with serum AFB(1)-albumin adduct and dose-time interaction with urinary AFM (1) metabolites. The results suggest that capsules containing NS clay can be used to reduce effectively the bioavailability of dietary AF based on a reduction of AF-specific biomarkers.
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Affiliation(s)
- P Wang
- Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA
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Afriyie-Gyawu E, Ankrah NA, Huebner HJ, Ofosuhene M, Kumi J, Johnson NM, Tang L, Xu L, Jolly PE, Ellis WO, Ofori-Adjei D, Williams JH, Wang JS, Phillips TD. NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis. I. Study design and clinical outcomes. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2007; 25:76-87. [PMID: 17852392 DOI: 10.1080/02652030701458105] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A 3-month double-blind and placebo-controlled, phase IIa clinical trial was conducted in Ghana to investigate the safety, tolerance and aflatoxin-sorption efficacy of dietary NovaSil (NS). Volunteers (507 subjects) were clinically screened to evaluate their general health, pregnancy status and blood AFB(1)-albumin adduct levels. Of these subjects, 177 were randomly assigned to three groups: high-dose (HD), low-dose (LD) and placebo-control (PL) groups receiving 3.0, 1.5 and 0 g NS day(-1) in capsules. Trained study-monitors supervised NS capsule administration to participants and recorded side-effects daily. Physical examinations were performed monthly. Blood and urine samples were collected for laboratory analysis. Approximately 92% of the participants (162 of 177) completed the study and compliance rate was over 97%. Overall, 99.5% of person x time reported no side-effects throughout the study. Mild to moderate health events ( approximately 0.5% of person x time) were recorded in some participants. Symptoms included nausea, diarrhea, heartburn and dizziness. These side-effects were statistically similar among all three groups. No significant differences were shown in hematology, liver and kidney function or electrolytes in the three groups. These findings demonstrate that NS clay is apparently safe and practical for the protection of humans against aflatoxins in populations at high risk for aflatoxicosis.
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Affiliation(s)
- E Afriyie-Gyawu
- College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
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Chern GD, Fernandes GE, Chang RK, Song Q, Xu L, Kneissl M, Johnson NM. High-Q-preserving coupling between a spiral and a semicircle micro-cavity. Opt Lett 2007; 32:1093-5. [PMID: 17410246 DOI: 10.1364/ol.32.001093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
We present an efficient design for direct coupling between a spiral-shaped and a semicircle-shaped microcavity (micro-cavity) as an alternative to traditional evanescent wave coupling for planar integrated photonic technology. We observe the preservation of the high Q-value of the spiral oscillator when coupled to a semicircle under current injection using an AlGaAs single-quantum-well heterostructure. With slight alterations to the directly coupled micro-cavity configuration, such as coupling shape and overlap distance, the number of observed modes and output intensity are changed. AlGaAs and InGaN spiral-shaped microcavities have unidirectional emission normal to the spiral notch.
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Affiliation(s)
- G D Chern
- Department of Applied Physics, Yale University, CT 06520, USA.
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Brownlie JC, Johnson NM, Whyard S. The Caenorhabditis briggsae genome contains active CbmaT1 and Tcb1 transposons. Mol Genet Genomics 2005; 273:92-101. [PMID: 15702348 DOI: 10.1007/s00438-005-1110-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Accepted: 01/03/2005] [Indexed: 10/25/2022]
Abstract
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.
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Affiliation(s)
- J C Brownlie
- CSIRO Division of Entomology, GPO Box 1700, Canberra, ACT, 2601, Australia.
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Dickson KA, Johnson NM, Donley JM, Hoskinson JA, Hansen MW, D'Souza Tessier J. Ontogenetic changes in characteristics required for endothermy in juvenile black skipjack tuna (Euthynnus lineatus). J Exp Biol 2000; 203:3077-87. [PMID: 11003819 DOI: 10.1242/jeb.203.20.3077] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To characterize better the development of endothermy in tunas, we assessed how the abilities to generate heat and to conserve heat within the aerobic, slow-twitch (red) myotomal muscle using counter-current heat exchangers (retia) change with size in juvenile black skipjack tuna (Euthynnus lineatus) above and below the hypothesized minimum size for endothermy of 207 mm fork length (FL). Early juvenile scombrids (10–77 mm FL) collected off the Pacific coast of Panama were raised to larger sizes at the Inter-American Tropical Tuna Commission Laboratory at Achotines Bay, Panama. Evidence of central and lateral rete blood vessels was found in E. lineatus as small as 95.9 mm FL and 125 mm FL, respectively. In larger E. lineatus juveniles (up to 244 mm FL), the capacity for heat exchange increased with fork length as a result of increases in rete length, rete width and the number of vessel rows. The amount (g) of red muscle increased exponentially with fork length in both E. lineatus (105–255 mm FL) and a closely related ectothermic species, the sierra Spanish mackerel Scomberomorus sierra (151–212 mm FL), but was greater in E. lineatus at a given fork length. The specific activity (international units g(−)(1)) of the enzyme citrate synthase in red muscle, an index of tissue heat production potential, increased slightly with fork length in juvenile E. lineatus (84. 1–180 mm FL) and S. sierra (122–215 mm FL). Thus, total red muscle heat production capacity (red muscle citrate synthase activity per gram times red muscle mass in grams) increased with fork length, primarily because of the increase in red muscle mass. Below 95.9 mm FL, E. lineatus cannot maintain red muscle temperature (T(m)) above the ambient water temperature (T(a)) because juveniles of this size lack retia. Above 95.9 mm FL, the relationship between T(x) (T(m)-T(a)) and FL for E. lineatus diverges from that for the ectothermic S. sierra because of increases in the capacities for both heat production and heat retention that result in the development of endothermy.
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Affiliation(s)
- K A Dickson
- Department of Biological Science, California State University Fullerton, Fullerton, CA 92834-6850, USA.
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du Bois RM, Greenhalgh PM, Southcott AM, Johnson NM, Harris TA. Randomized trial of inhaled fluticasone propionate in chronic stable pulmonary sarcoidosis: a pilot study. Eur Respir J 1999; 13:1345-50. [PMID: 10445610 DOI: 10.1183/09031936.99.13613519] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pulmonary sarcoidosis is a disease in which the pathological processes are distributed along lymphatic pathways, particularly those around the bronchovascular bundles. Delivery of disease-modulating drugs by the inhaled route is therefore an attractive option. The aim of this study was to determine the efficacy of inhaled fluticasone propionate 2 mg x day(-1) in adults with stable pulmonary sarcoidosis. Forty-four adult patients (22 from each centre) were enrolled from outpatient clinics in two London teaching hospitals in a two centre, double-blind, randomized, placebo-controlled trial. Primary end points were home recordings of peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC). Secondary end points were symptom scores, use of rescue bronchodilator medication, and clinic values for PEFR, FEV1, FVC, forced mid-expiratory flow (FEF25-75%), diffusion capacity of the lung for carbon monoxide (DL,CO), and total lung capacity (TLC). Symptom scores of cough, breathlessness and wheeze were lower in the active treatment group, but this did not reach statistical significance, and a general health perception assessment (Short Form (SF)-36) showed a difference between active and placebo treatment. No significant differences were found between the two groups in any physiological outcome measure. No new adverse reactions were detected. The results of this pilot study do not show an objective benefit of inhaled fluticasone propionate in pulmonary sarcoidosis where the disease is stable and is controlled without the use of inhaled corticosteroids.
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Affiliation(s)
- R M du Bois
- Respiratory Directorate, Royal Brompton Hospital, London, UK
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Nickel NH, Johnson NM, Walker J. Hydrogen-induced generation of acceptorlike defects in polycrystalline silicon. Phys Rev Lett 1995; 75:3720-3723. [PMID: 10059710 DOI: 10.1103/physrevlett.75.3720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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McCluskey MD, Haller EE, Walker J, Johnson NM. Vibrational spectroscopy of group-II-acceptor-hydrogen complexes in GaP. Phys Rev B Condens Matter 1995; 52:11859-11864. [PMID: 9980321 DOI: 10.1103/physrevb.52.11859] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Jackson WB, Johnson NM. Effect of non-Ohmic back contacts in capacitance transient measurements on hydrogenated amorphous silicon. Phys Rev B Condens Matter 1995; 52:R2233-R2236. [PMID: 9981379 DOI: 10.1103/physrevb.52.r2233] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Johnson NM, Herring C. Johnson, Herring, and Van de Walle reply. Phys Rev Lett 1995; 74:4566. [PMID: 10058541 DOI: 10.1103/physrevlett.74.4566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Brower KL, Myers SM, Edwards AH, Johnson NM, Poindexter EH. Comment on "Electron paramagnetic resonance of molecular hydrogen in silicon". Phys Rev Lett 1994; 73:1456. [PMID: 10056797 DOI: 10.1103/physrevlett.73.1456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Nickel NH, Johnson NM. Hydrogen-induced metastable changes in the electrical conductivity of polycrystalline silicon. Phys Rev Lett 1994; 72:3393-3396. [PMID: 10056187 DOI: 10.1103/physrevlett.72.3393] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Brandt MS, Ager JW, Götz W, Johnson NM, Harris JS, Molnar RJ, Moustakas TD. Local vibrational modes in Mg-doped gallium nitride. Phys Rev B Condens Matter 1994; 49:14758-14761. [PMID: 10010572 DOI: 10.1103/physrevb.49.14758] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Fidler HM, Thurrell W, Johnson NM, Rook GA, McFadden JJ. Specific detection of Mycobacterium paratuberculosis DNA associated with granulomatous tissue in Crohn's disease. Gut 1994; 35:506-10. [PMID: 8174989 PMCID: PMC1374800 DOI: 10.1136/gut.35.4.506] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The role of mycobacteria, specifically Mycobacterium paratuberculosis, in Crohn's disease has aroused considerable controversy for many years. Using the ultra sensitive polymerase chain reaction some studies have reported detection of M paratuberculosis DNA in as many as 65% of Crohn's disease patients but also in patients without disease. Other studies have been negative for both groups. We therefore designed a double blind control trial to investigate the presence of mycobacterial DNA in age, sex, and tissue matched paraffin wax embedded tissues from 31 Crohn's disease tissues, 20 diseased gut control tissues, and 10 ulcerative colitis tissues. The specimens were coded and analysed blind with three separate polymerase chain reactions (PCR) based on DNA sequences specific for M paratuberculosis (IS900), M avium (RFLP type A/1) (IS901), and the Mycobacterium genus (65 kDa gene, TB600). The number of granulomata and presence of acid fast bacilli in each Crohn's disease tissue was also investigated. The sensitivity of the system was determined using similarly prepared gut tissue from an animal infected with M paratuberculosis. Four of 31 Crohn's disease tissues and none of the 30 control and ulcerative colitis derived tissues amplified M paratuberculosis DNA. Crohn's disease tissues containing granulomata were significantly more likely to amplify M paratuberculosis specific DNA on PCR than the non-Crohn's disease tissues (p = 0.02). All the positive Crohn's disease tissues contained granulomata, and none contained acid fast bacilli. Equivalent numbers of Crohn's and non-Crohn's disease tissues amplified the region of the 65 kD gene on PCR for non-specific mycobacterial DNA (11/31 and 9/30 respectively). No sections produced an amplified product with the IS901 PCR. These results suggest that few Crohn's disease gut biopsy sections contain M paratuberculosis DNA in association with granulomata. The absence of such DNA in any control and ulcerative colitic tissue strengthens the case for it having a specific association, which may be pathogenic, with Crohn's disease in this minority of patients.
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Affiliation(s)
- H M Fidler
- Department of Medicine, University College London Medical School, Guildford
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Fidler H, Rook GA, Johnson NM, McFadden JJ. Specificity of primers based on IS6110 to Mycobacterium tuberculosis complex DNA. Tuber Lung Dis 1993; 74:414-5. [PMID: 8136502 DOI: 10.1016/0962-8479(93)90095-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Nickel NH, Jackson WB, Johnson NM. Light-induced creation of metastable paramagnetic defects in hydrogenated polycrystalline silicon. Phys Rev Lett 1993; 71:2733-2736. [PMID: 10054762 DOI: 10.1103/physrevlett.71.2733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Gomm PJ, Broster CG, Johnson NM, Hammond K. Study into the ability of healthy people of small stature to satisfy the sampling requirements of breath alcohol testing instruments. Med Sci Law 1993; 33:311-314. [PMID: 8264364 DOI: 10.1177/002580249303300408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In a previous study (Gomm et al., 1991) people with a variety of respiratory diseases were tested and criteria defined for assessing their ability to provide samples for Breath Alcohol Testing Instruments. This study investigated the possible problems which may be encountered by healthy people of small stature--5ft 5in (166cm) or less--who do not suffer from a respiratory disease. This study followed the same pattern as the earlier work in that lung function (Forced Expiration Volume in One Second (FEV1) and Forced Vital Capacity (FVC)) was measured by spirometry, and Peak Expiration Flow Rate (PEFR) was measured using a Wright peak flow meter. Following the lung function measurements the subjects were requested to provide samples for Breath Alcohol Testing Instruments used by the Police in Great Britain. As with the previously reported work (Gomm et al., 1991), this study found that the FEV1 and FVC gave the most reliable indication of a person's capability of satisfying the sampling requirements of Breath Alcohol Testing Instruments, but on this occasion the PEFR also provided a good confirmatory indication. Because there were no subjects with interstitial lung diseases the values determined by this study on 48 healthy adults indicate that a healthy person of small stature should be capable of supplying a suitable breath sample if their FEV1, FVC and PEFR are greater than 2.31, 2.61 and 330 l/min respectively.
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Affiliation(s)
- P J Gomm
- Forensic Science Service, Aldermaston, Reading, Berkshire
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