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Izawa T, Travlos GS, Cortes RA, Clayton NP, Sills RC, Pandiri AR. Absence of Increased Susceptibility to Acetaminophen-Induced Liver Injury in a Diet-Induced NAFLD Mouse Model. Toxicol Pathol 2023; 51:112-125. [PMID: 37158481 PMCID: PMC10523943 DOI: 10.1177/01926233231171101] [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] [Indexed: 05/10/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease and its influence on drug-induced liver injury (DILI) is not fully understood. We investigated whether NAFLD can influence acetaminophen (APAP [N-acetyl-p-aminophenol])-induced hepatotoxicity in a diet-induced obese (DIO) mouse model of NAFLD. The male C57BL/6NTac DIO mice, fed a high-fat diet for more than 12 weeks, developed obesity, hyperinsulinemia, impaired glucose tolerance, and hepatomegaly with hepatic steatosis, similar to human NAFLD. In the acute toxicity study after a single dose of APAP (150 mg/kg), compared with control lean mice, the DIO mice had decreased serum transaminase levels and less severe hepatocellular injury. The DIO mice also had altered expression of genes related to APAP metabolism. Chronic APAP exposure for 26 weeks did not predispose the DIO mice with NAFLD to more severe hepatotoxicity compared with the lean mice. These results suggested that the C57BL/6NTac DIO mouse model appears to be more tolerant to APAP-induced hepatotoxicity than lean mice, potentially related to altered xenobiotic metabolizing capacity in the fatty liver. Further mechanistic studies with APAP and other drugs in NAFLD animal models are necessary to investigate the mechanism of altered susceptibility to intrinsic DILI in some human NAFLD patients.
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Affiliation(s)
- Takeshi Izawa
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
- Laboratory of Veterinary Pathology, Osaka Metropolitan University, Izumisano, Osaka, Japan
| | - Gregory S. Travlos
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
| | - Ricardo A. Cortes
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
- Experimental Pathology Laboratories, Inc., Research Triangle Park, NC, USA
| | - Natasha P. Clayton
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
| | - Robert C. Sills
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
| | - Arun R. Pandiri
- Comparative and Molecular Pathogenesis Branch, Division of Translational Toxicology, NIEHS, Research Triangle Park, NC, USA
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Cupul-Uicab LA, Bornman R, Archer JI, Kudumu MO, Travlos GS, Wilson RE, Whitworth KW. Exposure to DDT from indoor residual spraying and biomarkers of inflammation among reproductive-aged women from South Africa. Environ Res 2020; 191:110088. [PMID: 32853661 PMCID: PMC7658024 DOI: 10.1016/j.envres.2020.110088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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: 02/27/2020] [Revised: 08/10/2020] [Accepted: 08/14/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Evidence from animal studies suggests that DDT and DDE can adversely affect immuno-competence while human data are less conclusive. We aimed to assess the association of plasma concentrations of DDT and DDE with biomarkers of inflammation among reproductive-aged women residing in homes sprayed with DDT through Indoor Residual Spraying (IRS). METHODS This study included 416 women from the Study of Women and Babies, South Africa (2010-2011). DDT, DDE, and biomarkers of inflammation (immunoglobulins A, G and M, interleukins 1β, 6, and 8, tumor necrosis factor-α, C-reactive protein, serum amyloid-A, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) were quantified in plasma. Linear regression was used to assess associations of DDT and DDE with each natural log-transformed biomarker. Models were adjusted for age, body mass index, parity, income, and season; beta estimates were expressed as percent differences. RESULTS Compared to women with the lowest plasma concentrations of DDT and DDE, those with the highest concentrations of both compounds had higher levels IL-1β, IL6, and TNF- α. While associations were statistically significant for both DDT and DDE, the magnitude of the associations was slightly stronger for DDT. Compared to women in the lowest quintile of DDT, women in the highest quintile were estimated to have 53.0% (95%CI: 21.7%, 84.4%), 28.1% (95%CI: 6.4%, 49.8%), and 26.6% (95%CI: 12.0%, 41.1%) higher levels of IL-1β, IL6, and TNF- α, respectively. CONCLUSIONS Our results suggest that increased plasma concentrations of DDT and DDE resulting from exposure to IRS may increase concentrations of pro-inflammatory biomarkers among reproductive-aged women in South Africa.
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Affiliation(s)
- Lea A Cupul-Uicab
- Center for Population Health Research, National Institute of Public Health, Morelos, Mexico.
| | - Riana Bornman
- School of Health Systems and Public Health, University of Pretoria, Pretoria, South Africa.
| | | | | | - Gregory S Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA.
| | - Ralph E Wilson
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA.
| | - Kristina W Whitworth
- Epidemiology and Population Sciences Section, Department of Medicine, Baylor College of Medicine, Houston, TX, USA; Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, USA.
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Whiteside TE, Qu W, DeVito MJ, Brar SS, Bradham KD, Nelson CM, Travlos GS, Kissling GE, Kurtz DM. Elevated Arsenic and Lead Concentrations in Natural Healing Clay Applied Topically as a Treatment for Ulcerative Dermatitis in Mice. J Am Assoc Lab Anim Sci 2020; 59:212-220. [PMID: 32059757 PMCID: PMC7073401 DOI: 10.30802/aalas-jaalas-19-000068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 05/01/2019] [Revised: 06/10/2019] [Accepted: 08/22/2019] [Indexed: 11/05/2022]
Abstract
Ulcerative dermatitis in laboratory mice remains an ongoing clinical problem and animal welfare issue. Many products have been used to treat dermatitis in mice, with varying success. Recently, the topical administration of healing clays, such as bentonite and green clays, has been explored as a viable, natural treatment. We found high concentrations of arsenic and lead in experimental samples of therapeutic clay. Given the known toxic effects of these environmental heavy metals, we sought to determine whether the topical administration of a clay product containing bioavailable arsenic and lead exerted a biologic effect in mice that potentially could introduce unwanted research variability. Two cohorts of 20 singly housed, shaved, dermatitis free, adult male CD1 mice were dosed daily for 2 wk by topical application of saline or green clay paste. Samples of liver, kidney and whole blood were collected and analyzed for total arsenic and lead concentrations. Hepatic and renal concentrations of arsenic were not different between treated and control mice in either cohort; however, hepatic and renal concentrations of lead were elevated in clay treated mice compared to controls in both cohorts. In addition, in both cohorts, the activity of δ-aminolevulinate acid dehydratase, an enzyme involved with heme biosynthesis and a marker of lead toxicity, did not differ significantly between the clay-treated mice and controls. We have demonstrated that these clay products contain high concentrations of arsenic and lead and that topical application can result in the accumulation of lead in the liver and kidneys; however, these concentrations did not result in measurable biologic effects. These products should be used with caution, especially in studies of lead toxicity, heme biosynthesis, and renal α2 microglobulin function.
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Affiliation(s)
- Tanya E Whiteside
- Comparative Medicine Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Wei Qu
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Michael J DeVito
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Sukhdev S Brar
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Karen D Bradham
- Office of Research and Development, Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Clay M Nelson
- Office of Research and Development, Environmental Protection Agency, Research Triangle Park, North Carolina
| | - Gregory S Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Grace E Kissling
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - David M Kurtz
- Comparative Medicine Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina;,
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Cora MC, Janardhan KS, Jensen H, Clayton N, Travlos GS. Previously Diagnosed Reticulum Cell Hyperplasia in Decalcified Rat Bone Marrow Stain Positive for Ionized Calcium Binding Adapter Molecule 1 (Iba1): A Monocytic/Macrophage Cell Marker. Toxicol Pathol 2019; 48:317-322. [PMID: 31801420 DOI: 10.1177/0192623319890610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 12/20/2022]
Abstract
Reticulum cell hyperplasia (RCH) was a term used for many years by the National Toxicology Program (NTP) to describe a certain non-neoplastic bone marrow lesion of rats. Retrospective microscopic evaluation of RCH lesions and immunohistochemistry analyses were performed to reassess and further characterize these lesions. The NTP database was searched to identify femoral bone marrow specimens diagnosed with RCH from 1981 to 2014 (n = 254). The diagnosis last occurred in 2003, after which the term "cellular infiltration" was used. Eighty-three RCH slides, spanning 22 years, representing 34 different chemicals, were selected for microscopic review, and a subset (23) was chosen for ionized calcium binding adapter molecule 1 (Iba1) immunohistochemical staining; initial investigations revealed Iba1 worked as a macrophage marker on decalcified tissue. The following diagnoses were made upon reevaluation: 36 were consistent with cellularity increased, macrophage, 22 with histiocytic sarcoma, 8 with increased myeloid cells, 4 with autolysis, and 13 were normal appearance. All 23 RCH lesions stained positive for Iba1. Fifty-eight of 83 bone marrows previously diagnosed with RCH are consistent morphologically and immunohistochemically with cells of histiocytic origin. These results will help with interpretation of historical data and demonstrates that Iba1 can be used in decalcified bone marrow sections.
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Affiliation(s)
- Michelle C Cora
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Heather Jensen
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Natasha Clayton
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Gregory S Travlos
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Elmore SA, Cesta MF, Crabbs TA, Janardhan KS, Krane GA, Mahapatra D, Quist EM, Rinke M, Schaaf GW, Travlos GS, Wang H, Willson CJ, Wolf JC. Proceedings of the 2019 National Toxicology Program Satellite Symposium. Toxicol Pathol 2019; 47:913-953. [PMID: 31645210 PMCID: PMC6911009 DOI: 10.1177/0192623319876929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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] [Indexed: 12/14/2022]
Abstract
The 2019 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Raleigh, North Carolina, at the Society of Toxicologic Pathology's 38th annual meeting. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and topics covered during the symposium included aging mouse lesions from various strains, as well as the following lesions from various rat strains: rete testis sperm granuloma/fibrosis, ovarian cystadenocarcinoma, retro-orbital schwannoma, periductal cholangiofibrosis of the liver and pancreas, pars distalis hypertrophy, chronic progressive nephropathy, and renal tubule regeneration. Other cases included polyovular follicles in young beagle dogs and a fungal blood smear contaminant. One series of cases challenged the audience to consider how immunohistochemistry may improve the diagnosis of some tumors. Interesting retinal lesions from a rhesus macaque emphasized the difficulty in determining the etiology of any particular retinal lesion due to the retina's similar response to vascular injury. Finally, a series of lesions from the International Harmonization of Nomenclature and Diagnostic Criteria Non-Rodent Fish Working Group were presented.
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Affiliation(s)
- Susan A. Elmore
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Mark F. Cesta
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Torrie A Crabbs
- Experimental Pathology Laboratories, Inc., Research Triangle Park, North Carolina, USA
| | | | - Gregory A. Krane
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Debabrata Mahapatra
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina, USA
| | - Erin M. Quist
- Experimental Pathology Laboratories, Inc., Research Triangle Park, North Carolina, USA
| | | | - George W. Schaaf
- Wake Forest University School of Medicine, Winston Salem, North Carolina, USA
| | - Gregory S. Travlos
- Cellular and Molecular Pathology Branch, National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Haoan Wang
- West China-Frontier Pharma Tech Co., Ltd., Chengdu, Sichuan, China
| | - Cynthia J. Willson
- Integrated Laboratory Systems, Inc., Research Triangle Park, North Carolina, USA
| | - Jeffrey C. Wolf
- Experimental Pathology Laboratories, Inc., Sterling, Virginia, USA
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Conley JM, Lambright CS, Evans N, Strynar MJ, McCord J, McIntyre BS, Travlos GS, Cardon MC, Medlock-Kakaley E, Hartig PC, Wilson VS, Gray LE. Adverse Maternal, Fetal, and Postnatal Effects of Hexafluoropropylene Oxide Dimer Acid (GenX) from Oral Gestational Exposure in Sprague-Dawley Rats. Environ Health Perspect 2019; 127:37008. [PMID: 30920876 PMCID: PMC6768323 DOI: 10.1289/ehp4372] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 02/23/2019] [Accepted: 02/28/2019] [Indexed: 05/18/2023]
Abstract
BACKGROUND Hexafluoropropylene oxide dimer acid [(HFPO-DA), GenX] is a member of the per- and polyfluoroalkyl substances (PFAS) chemical class, and elevated levels of HFPO-DA have been detected in surface water, air, and treated drinking water in the United States and Europe. OBJECTIVES We aimed to characterize the potential maternal and postnatal toxicities of oral HFPO-DA in rats during sexual differentiation. Given that some PFAS activate peroxisome proliferator-activated receptors (PPARs), we sought to assess whether HFPO-DA affects androgen-dependent development or interferes with estrogen, androgen, or glucocorticoid receptor activity. METHODS Steroid receptor activity was assessed with a suite of in vitro transactivation assays, and Sprague-Dawley rats were used to assess maternal, fetal, and postnatal effects of HFPO-DA exposure. Dams were dosed daily via oral gavage during male reproductive development (gestation days 14-18). We evaluated fetal testes, maternal and fetal livers, maternal serum clinical chemistry, and reproductive development of F1 animals. RESULTS HFPO-DA exposure resulted in negligible in vitro receptor activity and did not impact testosterone production or expression of genes key to male reproductive development in the fetal testis; however, in vivo exposure during gestation resulted in higher maternal liver weights ([Formula: see text]), lower maternal serum thyroid hormone and lipid profiles ([Formula: see text]), and up-regulated gene expression related to PPAR signaling pathways in maternal and fetal livers ([Formula: see text]). Further, the pilot postnatal study indicated lower female body weight and lower weights of male reproductive tissues in F1 animals. CONCLUSIONS HFPO-DA exposure produced multiple effects that were similar to prior toxicity evaluations on PFAS, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), but seen as the result of higher oral doses. The mean dam serum concentration from the lowest dose group was 4-fold greater than the maximum serum concentration detected in a worker in an HFPO-DA manufacturing facility. Research is needed to examine the mechanisms and downstream events linked to the adverse effects of PFAS as are mixture-based studies evaluating multiple PFAS. https://doi.org/10.1289/EHP4372.
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Affiliation(s)
- Justin M. Conley
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Christy S. Lambright
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Nicola Evans
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Mark J. Strynar
- Exposure Methods and Measurements Division, National Exposure Research Laboratory, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - James McCord
- Exposure Methods and Measurements Division, National Exposure Research Laboratory, ORD, U.S. EPA, Research Triangle Park, North Carolina, USA
| | - Barry S. McIntyre
- Toxicology Branch, Division of the National Toxicology Program (NTP), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Gregory S. Travlos
- Cellular and Molecular Pathology Branch, NTP, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Mary C. Cardon
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Elizabeth Medlock-Kakaley
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Phillip C. Hartig
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - Vickie S. Wilson
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
| | - L. Earl Gray
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development (ORD), U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina, USA
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Misra A, Longnecker MP, Dionisio KL, Bornman RMS, Travlos GS, Brar S, Whitworth KW. Household fuel use and biomarkers of inflammation and respiratory illness among rural South African Women. Environ Res 2018; 166:112-116. [PMID: 29885612 PMCID: PMC6110960 DOI: 10.1016/j.envres.2018.05.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 11/09/2017] [Revised: 04/16/2018] [Accepted: 05/12/2018] [Indexed: 05/24/2023]
Abstract
Though literature suggests a positive association between use of biomass fuel for cooking and inflammation, few studies among women in rural South Africa exist. We included 415 women from the South African Study of Women and Babies (SOWB), recruited from 2010 to 2011. We obtained demographics, general medical history and usual source of cooking fuel (wood, electricity) via baseline questionnaire. A nurse obtained height, weight, blood pressure, and blood samples. We measured plasma concentrations of a suite of inflammatory markers (e.g., interleukins, tumor necrosis factor-α, C-reactive protein). We assessed associations between cooking fuel and biomarkers of inflammation and respiratory symptoms/illness using crude and adjusted linear and logistic regression models. We found little evidence of an association between fuel-use and biomarkers of inflammation, pre-hypertension/hypertension, or respiratory illnesses. Though imprecise, we found 41% (95% confidence interval (CI) = 0.72-2.77) higher odds of self-reported wheezing/chest tightness among wood-users compared with electricity-users. Though studies among other populations report positive findings between biomass fuel use and inflammation, it is possible that women in the present study experience lower exposures to household air pollution given the cleaner burning nature of wood compared with other biomass fuels (e.g., coal, dung).
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Affiliation(s)
- Ankita Misra
- Department of Epidemiology, Human Genetics and Environmental Sciences, UTHealth School of Public Health in San Antonio, San Antonio, TX, USA
| | - Matthew P Longnecker
- Epidemiology Branch, National Institute for Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC, USA
| | - Kathie L Dionisio
- National Exposure Research Laboratory, Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Riana M S Bornman
- Department of Urology, University of Pretoria, Pretoria, South Africa; Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA; The University of Pretoria Centre for Sustainable Malaria Control, University of Pretoria, Pretoria, South Africa
| | - Gregory S Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Sukhdev Brar
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Kristina W Whitworth
- Department of Epidemiology, Human Genetics and Environmental Sciences, UTHealth School of Public Health in San Antonio, San Antonio, TX, USA; Southwest Center for Occupational and Environmental Health, UTHealth School of Public Health, Houston, TX, USA.
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Henson K, Osborne T, Travlos GS. Hematopoietic System. Toxicol Pathol 2018. [DOI: 10.1201/9780429504624-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chernoff N, Hill DJ, Chorus I, Diggs DL, Huang H, King D, Lang JR, Le TT, Schmid JE, Travlos GS, Whitley EM, Wilson RE, Wood CR. Cylindrospermopsin toxicity in mice following a 90-d oral exposure. J Toxicol Environ Health A 2018; 81:549-566. [PMID: 29693504 PMCID: PMC6764423 DOI: 10.1080/15287394.2018.1460787] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 02/26/2018] [Indexed: 05/19/2023]
Abstract
Cylindrospermopsin (CYN) is a toxin associated with numerous species of freshwater cyanobacteria throughout the world. It is postulated to have caused an episode of serious illnesses in Australia through treated drinking water, as well as lethal effects in livestock exposed to water from farm ponds. Toxicity included effects indicative of both hepatic and renal dysfunction. In humans, symptoms progressed from initial hepatomegaly, vomiting, and malaise to acidosis and hypokalemia, bloody diarrhea, and hyperemia in mucous membranes. Laboratory animal studies predominantly involved the intraperitoneal (i.p.) route of administration and confirmed this pattern of toxicity with changes in liver enzyme activities and histopathology consistent with hepatic injury and adverse renal effects. The aim of this study was designed to assess subchronic oral exposure (90 d) of purified CYN from 75 to 300 µg/kg/d in mouse. At the end of the dosing period, examinations of animals noted (1) elevated organ to body weight ratios of liver and kidney at all dose levels, (2) treatment-related increases in serum alanine aminotransferase (ALT) activity, (3) decreased blood urea nitrogen (BUN) and cholesterol concentrations in males, and (4) elevated monocyte counts in both genders. Histopathological alterations included hepatocellular hypertrophy and cord disruption in the liver, as well as renal cellular hypertrophy, tubule dilation, and cortical tubule lesions that were more prominent in males. A series of genes were differentially expressed including Bax (apoptosis), Rpl6 (tissue regeneration), Fabp4 (fatty acid metabolism), and Proc (blood coagulation). Males were more sensitive to many renal end points suggestive of toxicity. At the end of exposure, toxicity was noted at all dose levels, and the 75 µg/kg group exhibited significant effects in liver and kidney/body weight ratios, reduced BUN, increased serum monocytes, and multiple signs of histopathology indicating that a no-observed-adverse-effect level could not be determined for any dose level.
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Affiliation(s)
- N Chernoff
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - D J Hill
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - I Chorus
- b Division of Drinking-Water and Swimming-Pool Hygiene , Umweltbundesamt , Berlin , Germany
| | - D L Diggs
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - H Huang
- d North Carolina State University , Raleigh , NC , USA
| | - D King
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - J R Lang
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - T-T Le
- c NHEERL , Oak Ridge Institute for Science and Education Internship/Research Participation Program at the US Environmental Protection Agency , Research Triangle Park , NC , USA
| | - J E Schmid
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
| | - G S Travlos
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - E M Whitley
- f Pathogenesis , LLC , Gainesville , FL , USA
| | - R E Wilson
- e Cellular and Molecular Pathology Branch , National Institute of Environmental Health Sciences , Research Triangle Park , NC , USA
| | - C R Wood
- a National Health and Environmental Effects Research Laboratory , US Environmental Protection Agency, Office of Research and Development , Research Triangle Park , NC , USA
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Dunnick JK, Shockley KR, Morgan DL, Brix A, Travlos GS, Gerrish K, Michael Sanders J, Ton TV, Pandiri AR. Hepatic transcriptomic alterations for N,N-dimethyl-p-toluidine (DMPT) and p-toluidine after 5-day exposure in rats. Arch Toxicol 2016; 91:1685-1696. [PMID: 27638505 DOI: 10.1007/s00204-016-1831-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [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: 06/24/2016] [Accepted: 08/24/2016] [Indexed: 12/17/2022]
Abstract
N,N-dimethyl-p-toluidine (DMPT), an accelerant for methyl methacrylate monomers in medical devices, was a liver carcinogen in male and female F344/N rats and B6C3F1 mice in a 2-year oral exposure study. p-Toluidine, a structurally related chemical, was a liver carcinogen in mice but not in rats in an 18-month feed exposure study. In this current study, liver transcriptomic data were used to characterize mechanisms in DMPT and p-toluidine liver toxicity and for conducting benchmark dose (BMD) analysis. Male F344/N rats were exposed orally to DMPT or p-toluidine (0, 1, 6, 20, 60 or 120 mg/kg/day) for 5 days. The liver was examined for lesions and transcriptomic alterations. Both chemicals caused mild hepatic toxicity at 60 and 120 mg/kg and dose-related transcriptomic alterations in the liver. There were 511 liver transcripts differentially expressed for DMPT and 354 for p-toluidine at 120 mg/kg/day (false discovery rate threshold of 5 %). The liver transcriptomic alterations were characteristic of an anti-oxidative damage response (activation of the Nrf2 pathway) and hepatic toxicity. The top cellular processes in gene ontology (GO) categories altered in livers exposed to DMPT or p-toluidine were used for BMD calculations. The lower confidence bound benchmark doses for these chemicals were 2 mg/kg/day for DMPT and 7 mg/kg/day for p-toluidine. These studies show the promise of using 5-day target organ transcriptomic data to identify chemical-induced molecular changes that can serve as markers for preliminary toxicity risk assessment.
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Affiliation(s)
- June K Dunnick
- Toxicology Branch, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA.
| | - Keith R Shockley
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Daniel L Morgan
- NTP Laboratory, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Amy Brix
- Experimental Pathology Laboratories, Inc., National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Gregory S Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Kevin Gerrish
- Molecular Genomics Core, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - J Michael Sanders
- National Cancer Institute at NIEHS, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - T V Ton
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
| | - Arun R Pandiri
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, P. O. Box 12233, Research Triangle Park, NC, 27709, USA
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Abstract
As a major hematopoietic and lymphoid organ, morphological evaluation of the bone marrow is an important component of toxicity or safety assessment studies. While definitive characterization of bone marrow lesions often requires cytological aspirates or smears, assessment of histological bone marrow sections provides information regarding tissue architecture and hematopoietic status that is relevant for the detection of direct or indirect responses to chemical exposure. A variety of lesions have been observed in bone marrow. For example, lesions involving disturbances in growth, degenerative changes, inflammatory changes and neoplasia have been described. Lesions identified in hematoxylin and eosin-stained sections typically represent changes in the hematopoietic cell lineage and/or stromal cells since definitive identification of lymphoid cells is difficult except in cases of lymphoma. This review provides a descriptive and pictorial representation of a wide range of bone marrow lesions. Since large animal-to-animal variation may exist and there can be collection site- and age-related differences, it is imperative that the pathologist reviews all potential treatment-related findings against appropriate concurrent controls.
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Affiliation(s)
- Gregory S Travlos
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, National Institutes of Health, 111 Alexander Drive, Research Triangle Park, NC 27709, USA.
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12
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Abstract
The goal of this study was to determine whether the use of nesting material or polycarbonate shelters as enrichment devices would have an impact on end points commonly measured during the conduct of the National Toxicology Program (NTP) 13-week studies. The study design was consistent with the NTP 13-week toxicity studies. Harlan Sprague-Dawley (HSD) rats and their offspring and B6C3F1/N mice were assigned to control (unenriched) and enriched experimental groups. Body weight, food and water consumption, behavioral observations, fecal content, clinical pathology, gross pathology, organ weights, and histopathology were evaluated. Enriched male mice and male and female rats exhibited decreased feed intake without a subsequent decrease in body weight; this may have been the result of the nesting material reducing the effect of cold stress, thereby allowing for more efficient use of feed. There were statistical differences in some hematological parameters; however, these were not considered physiologically relevant since all values were within the normal range. Gross pathology and histopathological findings were background changes and were not considered enrichment-related. Nesting material and shelters were used frequently and consistently and allowed animals to display species-typical behavior. There was no significant impact on commonly measured end points in HSD rats and B6C3F1/N mice given enrichment devices.
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Affiliation(s)
- Sheba R Churchill
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Daniel L Morgan
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Grace E Kissling
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Gregory S Travlos
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Angela P King-Herbert
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Cheng J, Dackor RT, Bradbury JA, Li H, DeGraff LM, Hong LK, King D, Lih FB, Gruzdev A, Edin ML, Travlos GS, Flake GP, Tomer KB, Zeldin DC. Contribution of alveolar type II cell-derived cyclooxygenase-2 to basal airway function, lung inflammation, and lung fibrosis. FASEB J 2015; 30:160-73. [PMID: 26396235 DOI: 10.1096/fj.14-268458] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [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: 12/19/2014] [Accepted: 08/31/2015] [Indexed: 02/07/2023]
Abstract
Cyclooxygenase (COX)-2 has been shown to be involved in regulating basal airway function, bacterial LPS-induced airway hyperresponsiveness (AHR) and lung inflammation, and bleomycin-induced lung fibrosis; however, the cellular source of COX-2 that underlies these effects is unknown. We generated mice with alveolar type II (ATII) cell-specific knockdown of COX-2 (AT2CC(-/-)), to examine the role of ATII cell-derived prostaglandins (PGs) in these processes. Specific knockdown of COX-2 was confirmed by real-time RT-PCR and Western blot analyses. LC/MS/MS analysis showed that ATII cells produced PGs. Basal airway responsiveness of AT2CC(-/-) mice was decreased compared to that of wild-type (WT) mice. LPS-induced hypothermic response, infiltration of inflammatory cells into the airway, and lung inflammation were enhanced in AT2CC(-/-) mice relative to WT controls; however, LPS-induced AHR and proinflammatory cytokine and chemokine expression were similar between the genotypes. After 21 d of bleomycin administration, AT2CC(-/-) mice behaved in a manner similar to WT mice. Thus, ATII cell-derived COX-2 plays an important role in regulating basal airway function and LPS-induced lung inflammation, but does not play a role in bleomycin-induced fibrosis. These findings provide insight into the cellular source of COX-2 related to these lung phenotypes.
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Affiliation(s)
- Jennifer Cheng
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Ryan T Dackor
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - J Alyce Bradbury
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Hong Li
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Laura M DeGraff
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Lee K Hong
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Debra King
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Fred B Lih
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Artiom Gruzdev
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Matthew L Edin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Gregory S Travlos
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Gordon P Flake
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Kenneth B Tomer
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Darryl C Zeldin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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Morken NH, Travlos GS, Wilson RE, Eggesbø M, Longnecker MP. Maternal glomerular filtration rate in pregnancy and fetal size. PLoS One 2014; 9:e101897. [PMID: 25003331 PMCID: PMC4087025 DOI: 10.1371/journal.pone.0101897] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/12/2014] [Indexed: 11/18/2022] Open
Abstract
Background The relationship of maternal glomerular filtration rate (GFR) in pregnancy to fetal size needs to be better characterized as it impacts an ongoing debate about confounding effect of maternal GFR in investigations of important environmental contaminants. We aimed to characterize the size of the association between maternal GFR and infant birth weight. Materials and Methods A sub-cohort of 953 selected women (470 women with and 483 women without preeclampsia) in the Norwegian Mother and Child Cohort (MoBa), recruited during 2003–2007 were analyzed. GFR in the second trimester was estimated based on plasma creatinine. Birth weight was ascertained from the Medical Birth Registry of Norway. Multivariate linear regression was used to evaluate the association between maternal GFR in second trimester (estimated by the Cockroft-Gault [GFR-CG] and the modification of diet in renal disease [GFR-MDRD] formulas) and infant birth weight. Partial correlation coefficients were also calculated. Results Maternal GFR-CG (β: 0.73 g/ml/min, p = 0.04) and GFR-MDRD (β: 0.83 g/ml/min, p = 0.04) were associated with infant birth weight in models adjusted for maternal weight in kilograms, preeclampsia, and gestational age at delivery (days). Partial correlation coefficients for the association between infant birth weight and GFR were 0.07 for both formulas. Although the birth weight-GFR association was stronger among the women with preeclampsia, the difference from women without preeclampsia was not statistically significant. Conclusion These data support an association between GFR during pregnancy and infant birth weight, and indicate that GFR may confound selected epidemiologic associations.
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Affiliation(s)
- Nils-Halvdan Morken
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
- Department of Clinical Sciences, University of Bergen, Bergen, Norway
- Department of Obstetrics and Gynecology, Haukeland University Hospital, Bergen, Norway
- * E-mail:
| | - Gregory S. Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, United States of America
| | - Ralph E. Wilson
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, United States of America
| | - Merete Eggesbø
- Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
| | - Matthew P. Longnecker
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, United States of America
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15
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Rider CV, Nyska A, Cora MC, Kissling GE, Smith C, Travlos GS, Hejtmancik MR, Fomby LM, Colleton CA, Ryan MJ, Kooistra L, Morrison JP, Chan PC. Toxicity and carcinogenicity studies of Ginkgo biloba extract in rat and mouse: liver, thyroid, and nose are targets. Toxicol Pathol 2014; 42:830-43. [PMID: 23960164 PMCID: PMC3929544 DOI: 10.1177/0192623313501235] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [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] [Indexed: 12/11/2022]
Abstract
Ginkgo biloba extract (GBE) is a popular herbal supplement that is used to improve circulation and brain function. In spite of widespread human exposure to relatively high doses over potentially long periods of time, there is a paucity of data from animal studies regarding the toxicity and carcinogenicity associated with GBE. In order to fill this knowledge gap, 3-month and 2-year toxicity and carcinogenicity studies with GBE administered by oral gavage to B6C3F1/N mice and F344/N rats were performed as part of the National Toxicology Program's Dietary Supplements and Herbal Medicines Initiative. The targets of GBE treatment were the liver, thyroid, and nose. These targets were consistent across exposure period, sex, and species, albeit with varying degrees of effect observed among studies. Key findings included a notably high incidence of hepatoblastomas in male and female mice and evidence of carcinogenic potential in the thyroid gland of both mice and rats. Various nonneoplastic lesions were observed beyond control levels in the liver, thyroid gland, and nose of rats and mice administered GBE. Although these results cannot be directly extrapolated to humans, the findings fill an important data gap in assessing risk associated with GBE use.
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Affiliation(s)
- Cynthia V Rider
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Abraham Nyska
- Integrated Laboratory Systems Incorporated, Research Triangle Park, Durham, North Carolina, USA
| | - Michelle C Cora
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Grace E Kissling
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Cynthia Smith
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Gregory S Travlos
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | | | | | | | | | - Linda Kooistra
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - James P Morrison
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - Po C Chan
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
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16
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Whitworth KW, Bornman RMS, Archer JI, Kudumu MO, Travlos GS, Wilson RE, Longnecker MP. Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB). Environ Health Perspect 2014; 122:545-52. [PMID: 24577839 PMCID: PMC4048257 DOI: 10.1289/ehp.1307025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 02/20/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. METHODS The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010-2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. RESULTS Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1-0.9] and 1.7 (IQR: 0.7-5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1-6.6) and 8.5 (IQR: 4.7-18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: -83, -57%) and 61% lower DDE (95% CI: -74, -40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: -63, -0.3%) than women who took fewer than four actions. CONCLUSION The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target.
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Affiliation(s)
- Kristina W Whitworth
- The University of Texas School of Public Health, San Antonio Regional Campus, San Antonio, Texas, USA
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17
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Starling AP, Engel SM, Richardson DB, Baird DD, Haug LS, Stuebe AM, Klungsøyr K, Harmon Q, Becher G, Thomsen C, Sabaredzovic A, Eggesbø M, Hoppin JA, Travlos GS, Wilson RE, Trogstad LI, Magnus P, Longnecker MP. Perfluoroalkyl substances during pregnancy and validated preeclampsia among nulliparous women in the Norwegian Mother and Child Cohort Study. Am J Epidemiol 2014; 179:824-33. [PMID: 24557813 DOI: 10.1093/aje/kwt432] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003-2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)(2)), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure.
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18
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Chernoff N, Rogers EH, Zehr RD, Gage MI, Travlos GS, Malarkey DE, Brix A, Schmid JE, Hill D. The course of toxicity in the pregnant mouse after exposure to the cyanobacterial toxin cylindrospermopsin: clinical effects, serum chemistries, hematology, and histopathology. J Toxicol Environ Health A 2014; 77:1040-60. [PMID: 25072824 DOI: 10.1080/15287394.2014.919838] [Citation(s) in RCA: 2] [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: 05/11/2023]
Abstract
Cylindrospermopsin (CYN) is a toxin produced by a variety of fresh-water cyanobacterial species worldwide and induces significant adverse effects in both livestock and humans. This study investigated the course of CYN-induced toxicity in pregnant mice exposed daily during either the period of major organogenesis (gestation days [GD] 8-12) or fetal growth (GD13-17). Endpoints include clinical signs of toxicity, serum analyses to evaluate hepatic and renal function, histopathology of liver and kidney, and hematology. Study animals were administered 50 μg/kg CYN once daily by ip route and euthanized 24 h after 1, 2, 3, 4, or 5 consecutive doses, or 6 or 13 d after the dosing period. The course of the CYN-induced effects was determined at all euthanasia times for the endpoints just outlined. Results indicated that CYN is a toxin, producing lethality in dams during the early part of gestation, significant weight loss, and bleeding in the gastrointestinal tract, tail tip, and peri-orbital tissues. Effects also included alterations in serum markers for liver function, histopathological changes in liver and kidney tissues, electrolyte abnormalities, leukocytosis, and posttreatment thrombocytopenia and reticulocytosis. The onset of symptoms was rapid, producing reductions in weight gain in GD8-12 animals, bleeding in the vaginal area in GD13-17 animals, and significant increases in sorbitol dehydrogenase (SDH) in both groups after a single dose. Although the GD8-12 dams displayed a 50% lethality, in GD13-17 animals only a single death occurred. Alterations seen in hepatic and renal function or histopathology do not appear to be of sufficient severity to produce death. Evidence indicates that bleeding may play a critical role in the onset of symptoms and eventually, in the observed lethality.
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Affiliation(s)
- N Chernoff
- a U.S. Environmental Protection Agency, ORD, National Health and Environmental Effects Research Laboratory , Research Triangle Park , North Carolina , USA
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19
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Starling AP, Engel SM, Whitworth KW, Richardson DB, Stuebe AM, Daniels JL, Haug LS, Eggesbø M, Becher G, Sabaredzovic A, Thomsen C, Wilson RE, Travlos GS, Hoppin JA, Baird DD, Longnecker MP. Perfluoroalkyl substances and lipid concentrations in plasma during pregnancy among women in the Norwegian Mother and Child Cohort Study. Environ Int 2014; 62:104-12. [PMID: 24189199 PMCID: PMC3870471 DOI: 10.1016/j.envint.2013.10.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [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: 02/18/2013] [Revised: 09/21/2013] [Accepted: 10/07/2013] [Indexed: 05/18/2023]
Abstract
BACKGROUND Perfluoroalkyl substances (PFASs) are widespread and persistent environmental pollutants. Previous studies, primarily among non-pregnant individuals, suggest positive associations between PFAS levels and certain blood lipids. If there is a causal link between PFAS concentrations and elevated lipids during pregnancy, this may suggest a mechanism by which PFAS exposure leads to certain adverse pregnancy outcomes, including preeclampsia. METHODS This cross-sectional analysis included 891 pregnant women enrolled in the Norwegian Mother and Child (MoBa) Cohort Study in 2003-2004. Non-fasting plasma samples were obtained at mid-pregnancy and analyzed for nineteen PFASs. Total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, and triglycerides were measured in plasma. Linear regression was used to quantify associations between each PFAS exposure and each lipid outcome. A multiple PFAS model was also fitted. RESULTS Seven PFASs were quantifiable in >50% of samples. Perfluorooctane sulfonate (PFOS) concentration was associated with total cholesterol, which increased 4.2mg/dL per inter-quartile shift (95% CI=0.8, 7.7) in adjusted models. Five of the seven PFASs studied were positively associated with HDL cholesterol, and all seven had elevated HDL associated with the highest quartile of exposure. Perfluoroundecanoic acid showed the strongest association with HDL: HDL increased 3.7 mg/dL per inter-quartile shift (95% CI=2.5, 4.9). CONCLUSION Plasma concentrations of PFASs were positively associated with HDL cholesterol, and PFOS was positively associated with total cholesterol in this sample of pregnant Norwegian women. While elevated HDL is not an adverse outcome per se, elevated total cholesterol associated with PFASs during pregnancy could be of concern if causal.
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Affiliation(s)
- Anne P. Starling
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Stephanie M. Engel
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kristina W. Whitworth
- The University of Texas Health Science Center at Houston School of Public Health, San Antonio Regional Campus, San Antonio, TX, USA
| | - David B. Richardson
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Alison M. Stuebe
- Department of Obstetrics and Gynecology and Department of Maternal and Child Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Julie L. Daniels
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | | | - Georg Becher
- Norwegian Institute of Public Health, Oslo, Norway
| | | | | | - Ralph E. Wilson
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Gregory S. Travlos
- Cellular and Molecular Pathology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Jane A. Hoppin
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Donna D. Baird
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
| | - Matthew P. Longnecker
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, NC, USA
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20
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Dunnick JK, Brix A, Sanders JM, Travlos GS. N,N-dimethyl-p-toluidine, a component in dental materials, causes hematologic toxic and carcinogenic responses in rodent model systems. Toxicol Pathol 2013; 42:603-15. [PMID: 23867143 DOI: 10.1177/0192623313489604] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [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: 11/16/2022]
Abstract
Because of the potential for exposure to N,N-dimethyl-p-toluidine (DMPT) in medical devices and the lack of toxicity and carcinogenicity information available in the literature, the National Toxicology Program conducted toxicity and carcinogenicity studies of DMPT in male and female F344/N rats and B6C3F1/N mice. In these studies, a treatment-related macrocytic regenerative anemia characterized by increased levels of methemoglobin and Heinz body formation developed within a few weeks of DMPT exposure in rats and mice. DMPT induced nasal cavity, splenic, and liver toxicity in rats and mice at 3 months and 2 years. DMPT carcinogenic effects were seen in the liver of male and female rats and mice, the nasal cavity of male and female rats, and the lung and forestomach of female mice. In rodents, DMPT is distributed to many of the sites where toxic and carcinogenic effects occurred. DMPT-induced oxidative damage at these target sites may be one mechanism for the treatment-related lesions. Methemoglobinemia, as seen in these DMPT studies, is caused by oxidation of the heme moiety, and this end point served as an early alert for other target organ toxicities and carcinogenic responses that followed with longer term exposure.
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Affiliation(s)
- June K Dunnick
- 1National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Abstract
Hexavalent chromium (Cr(VI)) is a contaminant of water and soil and is a human lung carcinogen. Trivalent chromium (Cr(III)), a proposed essential element, is ingested by humans in the diet and in dietary supplements such as chromium picolinate (CP). The National Toxicology Program (NTP) demonstrated that Cr(VI) is also carcinogenic in rodents when administered in drinking water as sodium dichromate dihydrate (SDD), inducing neoplasms of the oral cavity and small intestine in rats and mice, respectively. In contrast, there was no definitive evidence of toxicity or carcinogenicity following exposure to Cr(III) administered in feed as CP monohydrate (CPM). Cr(VI) readily enters cells via nonspecific anion channels, in contrast to Cr(III), which cannot easily pass through the cell membrane. Extracellular reduction of Cr(VI) to Cr(III), which occurs primarily in the stomach, is considered a mechanism of detoxification, while intracellular reduction is thought to be a mechanism of genotoxicity and carcinogenicity. Tissue distribution studies in additional groups of male rats and female mice demonstrated higher Cr concentrations in tissues following exposure to Cr(VI) compared to controls and Cr(III) exposure at a similar external dose, indicating that some of the Cr(VI) escaped gastric reduction and was distributed systemically. The multiple potential pathways of Cr-induced genotoxicity will be discussed.
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Affiliation(s)
- Kristine L. Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Matthew D. Stout
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Ronald A. Herbert
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Gregory S. Travlos
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Grace E. Kissling
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Bradley J. Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Michelle J. Hooth
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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22
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Cupul-Uicab LA, Skjaerven R, Haug K, Travlos GS, Wilson RE, Eggesbø M, Hoppin JA, Whitworth KW, Longnecker MP. Exposure to tobacco smoke in utero and subsequent plasma lipids, ApoB, and CRP among adult women in the MoBa cohort. Environ Health Perspect 2012; 120:1532-7. [PMID: 22814200 PMCID: PMC3556606 DOI: 10.1289/ehp.1104563] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [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: 09/30/2011] [Accepted: 07/19/2012] [Indexed: 05/05/2023]
Abstract
BACKGROUND Recent findings suggest that maternal smoking during pregnancy may play a role in the development of metabolic alterations in offspring during childhood. However, whether such exposure increases the risk of developing similar metabolic alterations during adulthood is uncertain. OBJECTIVE We evaluated the association of in utero exposure to maternal tobacco smoke with plasma lipids, apolipoprotein B (apoB), and C-reactive protein (CRP) in adulthood. METHODS The study was based on a subsample of the Norwegian Mother and Child Cohort Study (MoBa) and included 479 pregnant women with plasma lipids, apoB, and CRP measurements. Information on in utero exposure to tobacco smoke, personal smoking, and other factors were obtained from the women by a self-completed questionnaire at enrollment, at approximately 17 weeks of gestation. RESULTS Women exposed to tobacco smoke in utero had higher triglycerides [10.7% higher; 95% confidence interval (CI): 3.9, 17.9] and lower high-density lipoprotein cholesterol (HDL) (-1.9 mg/dL; 95% CI: -4.3, 0.5) compared with unexposed women, after adjusting for age, physical activity, education, personal smoking, and current body mass index (BMI). Exposed women were also more likely to have triglycerides ≥ 200 mg/dL [adjusted odds ratio (aOR) = 2.5; 95% CI: 1.3, 5.1] and HDL < 50 mg/dL (aOR = 2.3; 95% CI: 1.1, 5.0). Low-density lipoprotein cholesterol, total cholesterol, and apoB were not associated with the exposure. CRP was increased among exposed women; however, after adjustment for BMI, the association was completely attenuated. CONCLUSIONS In this population, in utero exposure to tobacco smoke was associated with high triglycerides and low HDL in adulthood, 18-44 years after exposure.
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Affiliation(s)
- Lea A Cupul-Uicab
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA.
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23
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Shiao YH, Leighty RM, Wang C, Ge X, Crawford EB, Spurrier JM, McCann SD, Fields JR, Fornwald L, Riffle L, Driver C, Kasprzak KS, Quiñones OA, Wilson RE, Travlos GS, Alvord WG, Anderson LM. Molecular and organismal changes in offspring of male mice treated with chemical stressors. Environ Mol Mutagen 2012; 53:392-407. [PMID: 22674528 DOI: 10.1002/em.21701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Both gene methylation changes and genetic instability have been noted in offspring of male rodents exposed to radiation or chemicals, but few specific gene targets have been established. Previously, we identified the gene for ribosomal RNA, rDNA, as showing methylation change in sperm of mice treated with the preconceptional carcinogen, chromium(III) chloride. rDNA is a critical cell growth regulator. Here, we investigated the effects of paternal treatments on rDNA in offspring tissue. A total of 93 litters and 758 offspring were obtained, permitting rigorous mixed-effects models statistical analysis of the results. We show that the offspring of male mice treated with Cr(III) presented increased methylation in a promoter sequence of the rDNA gene, specifically in lung. Furthermore polymorphic variants of the multi-copy rDNA genes displayed altered frequencies indicative of structural changes, as a function of both tissue type and paternal treatments. Organismal effects also occurred: some groups of offspring of male mice treated with either Cr(III) or its vehicle, acidic saline, compared with those of untreated mice, had altered average body and liver weights and levels of serum glucose and leptin. Males treated directly with Cr(III) or acidic saline presented serum hormone changes consistent with a stress response. These results establish for the first time epigenetic and genetic instability effects in a gene of central physiological importance, in offspring of male mice exposed preconceptionally to chemicals, possibly related to a stress response in these males.
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Affiliation(s)
- Yih-Horng Shiao
- Laboratory of Comparative Carcinogenesis, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
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24
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Chan PC, Peckham JC, Malarkey DE, Kissling GE, Travlos GS, Fu PP. Two-Year Toxicity and Carcinogenicity Studies of Panax ginseng in Fischer 344 Rats and B6C3F1 Mice. Am J Chin Med 2012; 39:779-88. [DOI: 10.1142/s0192415x11009184] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ginseng is one of the most popular herbal supplements on the US market. Numerous reports of adverse effects from products containing ginseng have been filed with the US Food and Drug Administration (FDA) and the literature documents a "ginseng abuse syndrome" among regular users. However, the chronic toxic effects of ginseng are not well characterized. Because of its significant human exposure and the fact that little information on its toxicity is available, Panax ginseng was nominated by the US National Institutes of Health (NIH) to the US National Toxicology Program (NTP) to assess its carcinogenic potential. In this paper, we reported the results of NTP chronic toxicity and tumorigenicity bioassay. It shows that, under these experimental conditions, Panax ginseng is not toxic or tumorigenic.
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Affiliation(s)
- Po-Chuen Chan
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - John C. Peckham
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - David E. Malarkey
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Grace E. Kissling
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Gregory S. Travlos
- National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Peter P. Fu
- National Center for Toxicological Research, Jefferson, AR 72079, USA
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25
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Behl M, Nyska A, Chhabra RS, Travlos GS, Fomby LM, Sparrow BR, Hejtmancik MR, Chan PC. Liver toxicity and carcinogenicity in F344/N rats and B6C3F1 mice exposed to Kava Kava. Food Chem Toxicol 2011; 49:2820-9. [PMID: 21871523 PMCID: PMC3190036 DOI: 10.1016/j.fct.2011.07.067] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [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: 05/18/2011] [Revised: 07/25/2011] [Accepted: 07/27/2011] [Indexed: 02/06/2023]
Abstract
Kava Kava is an herbal supplement used as an alternative to antianxiety drugs. Although some reports suggest an association of Kava Kava with hepatotoxicity , it continues to be used in the United States due to lack of toxicity characterization. In these studies F344/N rats and B6C3F1 mice were administered Kava Kava extract orally by gavage in corn oil for two weeks, thirteen weeks or two years. Results from prechronic studies administered Kava Kava at 0.125 to 2g/kg body weight revealed dose-related increases in liver weights and incidences of hepatocellular hypertrophy. In the chronic studies, there were dose-related increases in the incidences of hepatocellular hypertrophy in rats and mice administered Kava Kava for up to 1g/kg body weight. This was accompanied by significant increases in incidences of centrilobular fatty change. There was no treatment- related increase in carcinogenic activity in the livers of male or female rats in the chronic studies. Male mice showed a significant dose-related increase in the incidence of hepatoblastomas. In female mice, there was a significant increase in the combined incidence of hepatocellular adenoma and carcinoma in the low and mid dose groups but not in the high dose group. These findings were accompanied by several nonneoplastic hepatic lesions.
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Affiliation(s)
- Mamta Behl
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Abraham Nyska
- Integrated Laboratory Systems Inc., Research Triangle Park, NC 27709
| | - Rajendra S. Chhabra
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Gregory S. Travlos
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | | | | | | | - Po C. Chan
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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26
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Dackor RT, Cheng J, Voltz JW, Card JW, Ferguson CD, Garrett RC, Bradbury JA, DeGraff LM, Lih FB, Tomer KB, Flake GP, Travlos GS, Ramsey RW, Edin ML, Morgan DL, Zeldin DC. Prostaglandin E₂ protects murine lungs from bleomycin-induced pulmonary fibrosis and lung dysfunction. Am J Physiol Lung Cell Mol Physiol 2011; 301:L645-55. [PMID: 21856819 DOI: 10.1152/ajplung.00176.2011] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Prostaglandin E(2) (PGE(2)) is a lipid mediator that is produced via the metabolism of arachidonic acid by cyclooxygenase enzymes. In the lung, PGE(2) acts as an anti-inflammatory factor and plays an important role in tissue repair processes. Although several studies have examined the role of PGE(2) in the pathogenesis of pulmonary fibrosis in rodents, results have generally been conflicting, and few studies have examined the therapeutic effects of PGE(2) on the accompanying lung dysfunction. In this study, an established model of pulmonary fibrosis was used in which 10-12-wk-old male C57BL/6 mice were administered a single dose (1.0 mg/kg) of bleomycin via oropharyngeal aspiration. To test the role of prostaglandins in this model, mice were dosed, via surgically implanted minipumps, with either vehicle, PGE(2) (1.32 μg/h), or the prostacyclin analog iloprost (0.33 μg/h) beginning 7 days before or 14 days after bleomycin administration. Endpoints assessed at 7 days after bleomycin administration included proinflammatory cytokine levels and measurement of cellular infiltration into the lung. Endpoints assessed at 21 days after bleomycin administration included lung function assessment via invasive (FlexiVent) analysis, cellular infiltration, lung collagen content, and semiquantitative histological analysis of the degree of lung fibrosis (Ashcroft method). Seven days after bleomycin administration, lymphocyte numbers and chemokine C-C motif ligand 2 expression were significantly lower in PGE(2)- and iloprost-treated animals compared with vehicle-treated controls (P < 0.05). When administered 7 days before bleomycin challenge, PGE(2) also protected against the decline in lung static compliance, lung fibrosis, and collagen production that is associated with 3 wk of bleomycin exposure. However, PGE(2) had no therapeutic effect on these parameters when administered 14 days after bleomycin challenge. In summary, PGE(2) prevented the decline in lung static compliance and protected against lung fibrosis when it was administered before bleomycin challenge but had no therapeutic effect when administered after bleomycin challenge.
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Affiliation(s)
- Ryan T Dackor
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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27
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Shiao YH, Leighty RM, Wang C, Ge X, Crawford EB, Spurrier JM, McCann SD, Fields JR, Fornwald L, Riffle L, Driver C, Quiñones OA, Wilson RE, Kasprzak KS, Travlos GS, Alvord WG, Anderson LM. Ontogeny-driven rDNA rearrangement, methylation, and transcription, and paternal influence. PLoS One 2011; 6:e22266. [PMID: 21765958 PMCID: PMC3134480 DOI: 10.1371/journal.pone.0022266] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 06/21/2011] [Indexed: 11/18/2022] Open
Abstract
Gene rearrangement occurs during development in some cell types and this genome dynamics is modulated by intrinsic and extrinsic factors, including growth stimulants and nutrients. This raises a possibility that such structural change in the genome and its subsequent epigenetic modifications may also take place during mammalian ontogeny, a process undergoing finely orchestrated cell division and differentiation. We tested this hypothesis by comparing single nucleotide polymorphism-defined haplotype frequencies and DNA methylation of the rDNA multicopy gene between two mouse ontogenic stages and among three adult tissues of individual mice. Possible influences to the genetic and epigenetic dynamics by paternal exposures were also examined for Cr(III) and acid saline extrinsic factors. Variables derived from litters, individuals, and duplicate assays in large mouse populations were examined using linear mixed-effects model. We report here that active rDNA rearrangement, represented by changes of haplotype frequencies, arises during ontogenic progression from day 8 embryos to 6-week adult mice as well as in different tissue lineages and is modifiable by paternal exposures. The rDNA methylation levels were also altered in concordance with this ontogenic progression and were associated with rDNA haplotypes. Sperm showed highest level of methylation, followed by lungs and livers, and preferentially selected haplotypes that are positively associated with methylation. Livers, maintaining lower levels of rDNA methylation compared with lungs, expressed more rRNA transcript. In vitro transcription demonstrated haplotype-dependent rRNA expression. Thus, the genome is also dynamic during mammalian ontogeny and its rearrangement may trigger epigenetic changes and subsequent transcriptional controls, that are further influenced by paternal exposures.
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Affiliation(s)
- Yih-Horng Shiao
- Laboratory of Comparative Carcinogenesis, National Cancer Institute at Frederick, Frederick, Maryland, United States of America.
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28
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Shiao YH, Alvord WG, Ge X, Spurrier JM, McCann SD, Wang C, Crawford EB, Fields JR, Fornwald L, Riffle L, Patel P, Fortina P, Leighty RM, Quinones O, Wilson RE, Kasprzak K, Travlos GS, Anderson LM. Abstract 184: Stress-induced father-mediated 45S rRNA genetic and epigenetic reprogramming. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-184] [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
Environmental and dietary factors modify genomes and phenotypes. The extents of these modifications are not clear. DNA methylation and genotypes of the multi-copy 45S rRNA gene were quantified in 4 tissues at 3 developmental stages (sperm of 128 treated males, 98 litters of 876 day-8 embryos, and lung, liver, and a subset of sperm from 93 litters of 758 6-week adult offspring) in 3 treatment groups. Mixed models for adjusting confounding factors were used for all statistical analyses. Single injections of 1 mmol/kg chromium(III), [Cr(III)], an environmental agent and a dietary supplement, or acid saline (AS) vehicle were given to male mice only, which were then euthanized or bred 2 weeks later. A trend toward hypomethylation in the rRNA spacer promoter region but no frequency differences in 5 sequence variants of the rRNA, defined by 4 single nucleotide polymorphisms, were observed in sperm 2 weeks after Cr(III) treatment as compared to AS and untreated (UT) groups. This epigenetic trend disappeared at the day-8 embryo stage for both genders after paternal treatments with Cr(III) and/or AS. In offspring at 6 weeks of age, significant hypermethylation of the rRNA spacer-promoter was detected in the lung of the male offspring from Cr(III)-treated fathers, reversing the hypomethylation trend seen in the sperm 2 weeks after Cr(III) treatment. There was also a change in genotype: a significant reduction of the rRNA CGC variant in Cr(III) and/or AS groups in lung and liver in males, and in lung in females. Further examinations of the regressions of individual sequence variants on DNA methylation and on other variants revealed significant modifications to those correlates by Cr(III) and/or AS but to different degrees depending on the developmental stages, thus supporting the hypothesis of paternal exposure-induced epigenetic and genetic reprogramming. These genomic reprogrammings were accompanied by phenotypic changes related to paternal Cr(III) or AS treatment, including increased body and liver weights and alterations in serum glucose and leptin. Male mice treated with either Cr(III) or AS demonstrated a typical chemical stress response, as indicated by acute reduction in serum insulin and leptin, followed later by increases in these hormones. Taken together, this multi-faceted cross-generational study uncovers modifiable epigenetic and genetic reprogramming during development and differentiation. Paternal stress apparently had multiple effects on genomes and phenotypes, in their offspring.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 184.
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Affiliation(s)
| | - W G. Alvord
- 2Data Management Services Incorporated, Frederick, MD
| | - Xin Ge
- 3SAIC-Frederick, Frederick, MD
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29
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Bach U, Hailey JR, Hill GD, Kaufmann W, Latimer KS, Malarkey DE, Maronpot RM, Miller RA, Moore RR, Morrison JP, Nolte T, Rinke M, Rittinghausen S, Suttie AW, Travlos GS, Vahle JL, Willson GA, Elmore SA. Proceedings of the 2009 National Toxicology Program Satellite Symposium. Toxicol Pathol 2009; 38:9-36. [PMID: 20008954 DOI: 10.1177/0192623309354111] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The National Toxicology Program (NTP) Satellite Symposium is a one-day meeting that is held in conjunction with the annual Society of Toxicologic Pathology (STP) meeting. The topic of the 2009 Symposium was "Tumor Pathology and INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Nomenclature." The goal of this article is to provide summaries of each speaker's presentation, including the diagnostic or nomenclature issues that were presented, along with a few select images that were used for voting. The results of the voting process and interesting points of discussion that were raised during the presentation are also provided. A supplemental file with voting choices and voting results for each case presented at the symposium is available at http://tpx.sagepub.com/supplemental.
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Affiliation(s)
- Ute Bach
- 1Bayer HealthCare AG, Pharma Research Center, Wuppertal, Germany
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30
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Stout MD, Herbert RA, Kissling GE, Collins BJ, Travlos GS, Witt KL, Melnick RL, Abdo KM, Malarkey DE, Hooth MJ. Hexavalent chromium is carcinogenic to F344/N rats and B6C3F1 mice after chronic oral exposure. Environ Health Perspect 2009; 117:716-22. [PMID: 19479012 PMCID: PMC2685832 DOI: 10.1289/ehp.0800208] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [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: 09/19/2008] [Accepted: 12/31/2008] [Indexed: 05/04/2023]
Abstract
BACKGROUND Hexavalent chromium [Cr(VI)] is a human carcinogen after inhalation exposure. Humans also ingest Cr(VI) from contaminated drinking water and soil; however, limited data exist on the oral toxicity and carcinogenicity of Cr(VI). OBJECTIVE We characterized the chronic oral toxicity and carcinogenicity of Cr(VI) in rodents. METHODS The National Toxicology Program (NTP) conducted 2-year drinking water studies of Cr(VI) (as sodium dichromate dihydrate) in male and female F344/N rats and B6C3F1 mice. RESULTS Cr(VI) exposure resulted in increased incidences of rare neoplasms of the squamous epithelium that lines the oral cavity (oral mucosa and tongue) in male and female rats, and of the epithelium lining the small intestine in male and female mice. Cr(VI) exposure did not affect survival but resulted in reduced mean body weights and water consumption, due at least in part to poor palatability of the dosed water. Cr(VI) exposure resulted in transient microcytic hypochromic anemia in rats and microcytosis in mice. Nonneoplastic lesions included diffuse epithelial hyperplasia in the duodenum and jejunum of mice and histiocytic cell infiltration in the duodenum, liver, and mesenteric and pancreatic lymph nodes of rats and mice. CONCLUSIONS Cr(VI) was carcinogenic after administration in drinking water to male and female rats and mice.
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Affiliation(s)
- Matthew D Stout
- National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709 , USA.
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31
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D'Aloisio AA, Schroeder JC, North KE, Poole C, West SL, Travlos GS, Baird DD. IGF-I and IGFBP-3 polymorphisms in relation to circulating levels among African American and Caucasian women. Cancer Epidemiol Biomarkers Prev 2009; 18:954-66. [PMID: 19240240 DOI: 10.1158/1055-9965.epi-08-0856] [Citation(s) in RCA: 31] [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: 11/16/2022] Open
Abstract
Circulating insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3) levels have been associated with common diseases. Although family-based studies suggest that genetic variation contributes to circulating IGF-I and IGFBP-3 levels, analyses of associations with multiple IGF-I and IGFBP-3 single nucleotide polymorphisms (SNP) have been limited, especially among African Americans. We evaluated 30 IGF-I and 15 IGFBP-3 SNPs and estimated diplotypes in association with plasma IGF-I and IGFBP-3 among 984 premenopausal African American and Caucasian women. In both races, IGFBP-3 rs2854746 (Ala32Gly) was positively associated with plasma IGFBP-3 (CC versus GG mean difference among Caucasians, 631 ng/mL; 95% confidence interval, 398-864; African Americans, 897 ng/mL; 95% confidence interval, 656-1,138), and IGFBP-3 diplotypes with the rs2854746 GG genotype had lower mean IGFBP-3 levels than reference diplotypes with the CG genotype, whereas IGFBP-3 diplotypes with the CC genotype had higher mean IGFBP-3 levels. IGFBP-3 rs2854744 (-202 A/C) was in strong linkage disequilibrium with rs2854746 in Caucasians only, but was associated with plasma IGFBP-3 in both races. Eight additional IGFBP-3 SNPs were associated with >or=5% differences in mean IGFBP-3 levels, with generally consistent associations between races. Twelve IGF-I SNPs were associated with >or=10% differences in mean IGF-I levels, but associations were generally discordant between races. Diplotype associations with plasma IGF-I did not parallel IGF-I SNP associations. Our study supports that common IGFBP-3 SNPs, especially rs2854746, influence plasma IGFBP-3 levels among African Americans and Caucasians but provides less evidence that IGF-I SNPs affect plasma IGF-I levels.
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Affiliation(s)
- Aimee A D'Aloisio
- Epidemiology Branch, National Institute of Environmental Health Sciences, P.O. Box 12233, Mail Drop A3-05, Research Triangle Park, NC 27709, USA.
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32
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Stout MD, Bodes E, Schoonhoven R, Upton PB, Travlos GS, Swenberg JA. Toxicity, DNA Binding, and Cell Proliferation in Male F344 Rats following Short-term Gavage Exposures to Trans-2-Hexenal. Toxicol Pathol 2008; 36:232-46. [DOI: 10.1177/0192623307311758] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hexenal is a genotoxic compound to which humans are exposed daily through the consumption of foods and beverages. The present studies were conducted to examine the relationships between the dose-responses of trans-2-hexenal-induced toxicity, DNA adduct formation, and cell proliferation. Male F344 rats were exposed by gavage to single doses of up to 500 mg/kg and killed 1, 2, or 4 days after dosing or were exposed to repeat doses of up to 100 mg/kg once daily for 5 days or 5 days per week for 4 weeks and killed 1 day after the end of the dosing period. Histologically, the primary observations were necroulcerative lesions, inflammation, and hyperplasia in the forestomach and inflammation in the glandular stomach. Hexenal-derived DNA adduct formation and cell proliferation were induced in the forestomach at doses of hexenal that also induced gastric toxicity; DNA adducts were not observed in the glandular stomach. These findings suggest that the toxicity of hexenal was limited to the site of contact (stomach) and that the observed DNA adduct formation and cell proliferation occurred in the setting of severe tissue damage.
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Affiliation(s)
| | | | - Robert Schoonhoven
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, USA and
| | - Patricia B. Upton
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, USA and
| | - Gregory S. Travlos
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - James A. Swenberg
- Curriculum in Toxicology and
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, USA and
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Abstract
Clinical chemistry data are routinely generated as part of preclinical animal toxicity studies and human clinical studies. With large-scale studies involving hundreds or even thousands of samples in multiple treatment groups, it is currently difficult to interpret the resulting complex, high-density clinical chemistry data. Accordingly, we conducted this study to investigate methods for easy visualization of complex, high-density data. Clinical chemistry data were obtained from male rats each treated with one of eight different acute hepatotoxicants from a large-scale toxicogenomics study. The raw data underwent a Z-score transformation comparing each individual animal's clinical chemistry values to that of reference controls from all eight studies and then were visualized in a single graphic using a heat map. The utility of using a heat map to visualize high-density clinical chemistry data was explored by clustering changes in clinical chemistry values for >400 animals. A clear distinction was observed in animals displaying hepatotoxicity from those that did not. Additionally, while animals experiencing hepatotoxicity showed many similarities in the observed clinical chemistry alterations, distinct differences were noted in the heat map profile for the different compounds. Using a heat map to visualize complex, high-density clinical chemistry data in a single graphic facilitates the identification of previously unrecognized trends. This method is simple to implement and maintains the biological integrity of the data. The value of this clinical chemistry data transformation and visualization will manifest itself through integration with other high-density data, such as genomics data, to study physiology at the systems level.
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Affiliation(s)
| | | | | | | | - Richard S. Paules
- Corresponding Author: 111 T.W. Alexander Drive PO Box 12233, Mail Drop D2-03 Research Triangle Park, NC 27709 Phone: 919-541-3710 Fax: 919-316-4771
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Baird DD, Travlos GS. Obesity and Insulin-Like Growth Factor-I in African Americans and Whites. Cancer Epidemiol Biomarkers Prev 2007; 16:1526; author reply 1526. [PMID: 17627022 DOI: 10.1158/1055-9965.epi-07-0309] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Dunnick JK, Thayer KA, Travlos GS. Inclusion of biomarkers for detecting perturbations in the heart and lung and lipid/carbohydrate metabolism in National Toxicology Program studies. Toxicol Sci 2007; 100:29-35. [PMID: 17490986 PMCID: PMC2080693 DOI: 10.1093/toxsci/kfm113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Environmental factors and exposures may contribute to many serious diseases afflicting humans. Biomarkers are useful to understand disease processes and identify early events leading to disease. The National Toxicology Program (NTP) convened a workshop in September 2006 to help identify biomarkers that could be used in toxicology studies with rodents to predict disease outcome and detect early events in disease processes. Expert scientists reviewed biomarkers for disease/injury related to the heart, lung, and/or changes in lipid/carbohydrate metabolism and made recommendations for those that could be incorporated into NTP studies on a routine or selective basis. Although numerous biomarkers were discussed, only a few were considered amenable for routine use. This article summarizes recommendations for the most promising biomarkers and presents the NTP perspective on those that will be included in the bioassay program on a routine or special study basis. Breakout group reports and additional information on the workshop, including participants, presentations, and background materials, are posted on the NTP Web site http://ntp.niehs.nih.gov/go/20940.
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Affiliation(s)
- June K Dunnick
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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Abstract
While a complete blood count provides information regarding possible treatment-related effects reflected in the peripheral blood, morphological evaluation of bone marrow cytology and paraffin sections provides information about bone marrow tissue architecture that otherwise would be missed by examination of peripheral blood alone. In decalcified, paraffin-embedded, hematoxylin and eosin (H&E)-stained sections of bone marrow, the more mature stages of the erythroid and myeloid cells, adipocytes, mast cells, and megakaryocytes can be identified, but lymphoid cells as well as immature progenitor cells can not be reliably identified. The quality of the marrow sections is governed by numerous variables related to specimen collection and processing and must be considered. In addition to discussing normal structure, function, and histology of bone marrow, methods for preparation and evaluation of bone marrow are presented.
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Affiliation(s)
- Gregory S Travlos
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, National Institutes of Health, 111 Alexander Drive, Research Triangle Park, NC 27709, USA.
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Anderson LM, Riffle L, Wilson R, Travlos GS, Lubomirski MS, Alvord WG. Preconceptional fasting of fathers alters serum glucose in offspring of mice. Nutrition 2006; 22:327-31. [PMID: 16500559 DOI: 10.1016/j.nut.2005.09.006] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 09/27/2005] [Accepted: 09/30/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Maternal nutrition has long-term effects on offspring characteristics. Similar effects mediated through fathers have not been tested. METHODS Outbred Swiss male mice were fasted one or six times 1 to 4 wk before mating. Offspring were killed at age intervals of 4 to 10 wk and their sera were analyzed for glucose, corticosterone, and insulin-like growth factor-1. Statistical linear mixed effects models were used to determine treatment (paternal diet restriction versus control) differences and possible effects of covariates, including sex, litter membership, and litter size. RESULTS Paternal food deprivation resulted in a consistent decrease in average serum glucose in male and female offspring. Significant changes in corticosterone and insulin-like growth factor-1 were found for some groups. The results indicated a male-mediated transgenerational effect on metabolism- and growth-related parameters, in particular glucose. CONCLUSIONS Effects of paternal nutritional experiences on offspring metabolism, if confirmed, would be novel and could have far-reaching implications in the context of transgenerational effects on chronic diseases.
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Affiliation(s)
- Lucy M Anderson
- Laboratory of Comparative Carcinogenesis, National Cancer Institute, Frederick, Maryland, USA.
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Rhodes MC, Hébert CD, Herbert RA, Morinello EJ, Roycroft JH, Travlos GS, Abdo KM. Absence of toxic effects in F344/N rats and B6C3F1 mice following subchronic administration of chromium picolinate monohydrate. Food Chem Toxicol 2005; 43:21-9. [PMID: 15582192 DOI: 10.1016/j.fct.2004.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Accepted: 08/10/2004] [Indexed: 11/28/2022]
Abstract
Chromium picolinate monohydrate (CPM) is a synthetic compound heavily marketed to consumers in the United States for use as a dietary supplement for muscle building and weight loss. The National Toxicology Program (NTP) tested the toxicity of this compound based on the potential for widespread consumer exposure and lack of information about its toxicity. Groups of 10 male and 10 female F344/N rats and B6C3F(1) mice were exposed to 0, 80, 240, 2000, 10,000, or 50,000 ppm CPM in feed for 13 weeks. CPM administration produced no effect on body weight gain or survival of rats or mice. Organ weights and organ/body weight ratios in exposed animals were generally unaffected by CPM. No compound-related changes in hematology and clinical chemistry parameters were observed. There were no histopathological lesions attributed to CPM in rats or mice.
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Affiliation(s)
- M C Rhodes
- National Institute of Environmental Health Sciences, Mail Drop EC-34, 79 TW Alexander Drive, Research Triangle Park, NC 27709, United States.
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Heinloth AN, Irwin RD, Boorman GA, Nettesheim P, Fannin RD, Sieber SO, Snell ML, Tucker CJ, Li L, Travlos GS, Vansant G, Blackshear PE, Tennant RW, Cunningham ML, Paules RS. Gene expression profiling of rat livers reveals indicators of potential adverse effects. Toxicol Sci 2004; 80:193-202. [PMID: 15084756 DOI: 10.1093/toxsci/kfh145] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This study tested the hypothesis that gene expression profiling can reveal indicators of subtle injury to the liver induced by a low dose of a substance that does not cause overt toxicity as defined by conventional criteria of toxicology (e.g., abnormal clinical chemistry and histopathology). For the purpose of this study we defined this low dose as subtoxic, i.e., a dose that elicits effects which are below the detection of conventional toxicological parameters. Acetaminophen (APAP) was selected as a model hepatotoxicant because (1) considerable information exists concerning the mechanism of APAP hepatotoxicity that can occur following high doses, (2) intoxication with APAP is the leading cause of emergency room visits involving acute liver failure within the United States, and (3) conventional clinical markers have poor predictive value. Rats treated with a single dose of 0, 50, 150, or 1500 mg/kg APAP were examined at 6, 24, or 48 h after exposure for conventional toxicological parameters and for gene expression alterations. Patterns of gene expression were found which indicated cellular energy loss as a consequence of APAP toxicity. Elements of these patterns were apparent even after exposure to subtoxic doses. With increasing dose, the magnitude of changes increased and additional members of the same biological pathways were differentially expressed. The energy loss suggested by gene expression changes was confirmed at the 1500 mg/kg dose exposure by measuring ATP levels. Only by ultrastructural examination could any indication of toxicity be identified after exposure to a subtoxic dose of APAP and that was occasional mitochondrial damage. In conclusion, this study provides evidence that supports the hypothesis that gene expression profiling may be a sensitive means of identifying indicators of potential adverse effects in the absence of the occurrence of overt toxicity.
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Affiliation(s)
- Alexandra N Heinloth
- National Center for Toxicogenomics, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, North Carolina 27709, USA
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Ress NB, Hailey JR, Maronpot RR, Bucher JR, Travlos GS, Haseman JK, Orzech DP, Johnson JD, Hejtmancik MR. Toxicology and carcinogenesis studies of microencapsulated citral in rats and mice. Toxicol Sci 2003; 71:198-206. [PMID: 12563105 DOI: 10.1093/toxsci/71.2.198] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Citral, a widely used natural ingredient, is added to foods and cosmetics as a flavoring and fragrance agent. Male and female F344/N rats and B6C3F1 mice were exposed to microencapsulated citral in the feed for 14 weeks or two years. All studies included untreated and vehicle control groups. In the 14-week studies, rats and mice were given diets containing 3,900, 7,800, 15,600, or 31,300 ppm citral. In rats, food consumption was reduced in the two highest dose groups. In mice an apparent increase in food consumption was observed, but was due to mice scattering the feed. Body weights of all treated animals were less than controls. All rats and four male mice were killed moribund in the high dose groups. In rats, forestomach and kidney lesions were observed. At the higher doses, lesions observed in the bone marrow, testes, and thymus in rats and in the ovary in mice were considered related to inanition and resultant moribundity. In the two-year studies, rats were exposed to 1,000, 2,000, or 4,000 ppm citral. Body weights were reduced in the 4,000 ppm rats. Mice were exposed to 500, 1,000, or 2,000 ppm citral. Body weights in the 1,000 and 2,000 ppm groups were reduced. No neoplasms were attributed to citral in rats or mice. Malignant lymphoma occurred with a positive trend and was significantly greater than controls in female mice in the 2,000 ppm group. However, the incidences were within the NTP historical control range and could not be clearly related to citral administration.
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Affiliation(s)
- N B Ress
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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London SJ, Yuan JM, Travlos GS, Gao YT, Wilson RE, Ross RK, Yu MC. Insulin-like growth factor I, IGF-binding protein 3, and lung cancer risk in a prospective study of men in China. J Natl Cancer Inst 2002; 94:749-54. [PMID: 12011225 DOI: 10.1093/jnci/94.10.749] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Insulin-like growth factor I (IGF-I) stimulates cell proliferation and inhibits apoptosis in the lung and other tissues by interacting with the IGF-I receptor. The major binding protein for IGF-I, insulin-like growth factor-binding protein 3 (IGFBP-3), modulates the effects of IGF-I but also inhibits cell growth and induces apoptosis independent of IGF-I and its receptor. In a prospective study of men in Shanghai, China, we examined the association between serum levels of IGF-I and IGFBP-3 and the subsequent risk of lung cancer. METHODS From 1986 to 1989, serum was collected from 18,244 men aged 45-64 years living in Shanghai without a history of cancer. We analyzed IGF-I and IGFBP-3 levels in serum from 230 case patients who developed incident lung cancer during follow-up and from 740 control subjects. RESULTS Among 230 case patients and 659 matched control subjects, increased IGF-I levels were not associated with increased risk of lung cancer. However, for subjects in the highest quartile relative to the lowest quartile of IGFBP-3, the odds ratio (OR) for lung cancer, adjusted for smoking and IGF-I, was 0.50 (95% confidence interval [CI] = 0.25 to 1.02). When the analysis was restricted to ever smokers (184 case patients and 344 matched control subjects), the OR for lung cancer in men in the highest quartile of IGFBP-3 relative to those in the lowest quartile, adjusted for smoking and IGF-I, was 0.41 (95% CI = 0.18 to 0.92). CONCLUSIONS In this prospective study of Chinese men, higher serum levels of IGF-I did not increase the risk of lung cancer. However, subjects with higher serum levels of IGFBP-3 were at reduced risk of lung cancer. This finding is consistent with experimental data that indicate that IGFBP-3 can inhibit cellular proliferation and induce apoptosis independent of IGF-I and the IGF-I receptor.
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Affiliation(s)
- Stephanie J London
- Epidemiology Branch and Laboratory of Pulmonary Pathobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
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Abdo KM, Cunningham ML, Snell ML, Herbert RA, Travlos GS, Eldridge SR, Bucher JR. 14-Week toxicity and cell proliferation of methyleugenol administered by gavage to F344 rats and B6C3F1 mice. Food Chem Toxicol 2001; 39:303-16. [PMID: 11295478 DOI: 10.1016/s0278-6915(00)00143-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/23/2022]
Abstract
Methyleugenol, a food flavor and fragrance agent, was tested for toxicity in male and female F344/N rats and B6C3F1 mice. Groups of 10 males and 10 females per sex per species were administered 0, 10, 30, 100, 300 or 1000 mg methyleugenol/kg body weight in 0.5% aqueous methylcellulose by gavage, 5 days per week for 14 weeks. Additional groups of rats and mice of each sex were dosed similarly and used for hematology and clinical chemistry studies. Groups of 10 male and 10 female rats and mice received the vehicle by gavage on the same dosing schedule and served as vehicle controls. For serum gastrin, gastric pH and cell proliferation studies groups of 10 female rats were given 0, 37, 75 or 150 mg/kg, once daily 5 days per week for 30 or 90 days or 300 or 1000 mg/kg for 30 days; male mice were given 0, 9, 18.5, 37, 75, 150 or 300 mg/kg for 30 or 90 days. For the gastrin, pH and cell proliferation studies, groups of 10 female rats and 10 male mice were given the vehicle for 30 or 90 days and served as controls. Methyleugenol administration to rats induced erythrocyte microcytosis and thrombocytosis in male and female rats. It also caused an increase in serum alanine aminotransferase and sorbitol dehydrogenase activities and bile acid concentration, suggesting hepatocellular injury, cholestasis or altered hepatic function. Additionally, methyleugenol induced hypoproteinemia and hypoalbuminemia, evidenced by decreased total protein and albumin concentrations in both male and female rats, suggesting in inefficiency of dietary protein utilization due to methyleugenol-induced toxic effects on the liver and glandular stomach of rats and mice. The increase in gastrin and gastric pH of rats and mice given methyleugenol suggests that gastrin feedback was impaired and resulted in conditions not conducive to protein digestion. In rats, methyleugenol caused an increase in the incidences of hepatocyte cytologic alteration, cytomegaly, Kupffer cell pigmentation, mixed foci of cellular alteration and bile duct hyperplasia of the liver and atrophy and chronic inflammation of the mucosa of the glandular stomach. In mice, it caused an increase in the incidence of cytologic alteration, necrosis, bile duct hyperplasia and subacute inflammation of the liver and atrophy, degeneration, necrosis, edema, mitotic alteration, and cystic glands of the fundic region of the glandular stomach. The increased incidences of adrenal gland cortical hypertrophy and/or cytoplasmic alteration in the submandibular salivary glands, adrenal glands, testis and uterus of rats were considered secondary to the chemical-related effects observed in the liver and glandular stomach. Based on mortality, body weight gain, clinical chemistry and gross and microscopic evaluation of tissues of rats and mice, the no-observed-effect level (NOEL) of methyleugenol for both species was estimated at 10 mg/kg.
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Affiliation(s)
- K M Abdo
- National Institute of Environmental Health Sciences, Research, Triangle Park, NC 27709, USA
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Chhabra RS, Herbert RA, Bucher JR, Travlos GS, Johnson JD, Hejtmancik MR. Toxicology and carcinogenesis studies of p,p'-dichlorodiphenyl sulfone in rats and mice. Toxicol Sci 2001; 60:28-37. [PMID: 11222870 DOI: 10.1093/toxsci/60.1.28] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 11/14/2022] Open
Abstract
p,p'-Dichlorodiphenyl sulfone (DDS) is used as a starting material in the production of polysulfones and polyethersufones, a family of thermoplastics. DDS was studied because of its high production volume and use. In toxicology studies, 10 Fischer 344 rats and 10 B6C3F1 mice/sex/group were fed diets containing 0, 30, 100, 300, 1,000 or 3,000 ppm DDS for 14 weeks. All animals survived until the end of the studies. Mean body weights of groups exposed to 300 ppm or greater were significantly decreased. Liver and kidney in rats and liver in mice were the major target organs of DDS toxicity. Dose-related increases in liver weights and incidences of centrilobular hepatocyte hypertrophy were observed in DDS-exposed groups. Nephropathy was seen in male and female rats only at and above 300 ppm. Neurotoxicity evaluations were negative in DDS-treated animals. Clinical chemistry and hematology parameters were minimally affected. In the 2-year toxicity and carcinogenicity studies, 50 rats and 50 mice/sex/group were fed diets containing 0, 10 (male rats), 30, 100, or 300 ppm DDS for 104 to 105 weeks. Survival of exposed groups was not affected. There were no clinical signs of toxicity related to DDS exposure. Final mean body weights were 2-17% lower in DDS-treated groups. Liver was the only target organ of DDS-induced toxicity. The incidence of centrilobular hepatocyte hypertrophy in mice and rats, and the incidence of bile duct hyperplasia and centrilobular degeneration in female rats was significantly greater than in controls. A no-observed-adverse-effect level (NOAEL) of 30 ppm DDS in the diet (1.5 mg/kg body weight) was established for rats. DDS was not carcinogenic in these studies.
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Affiliation(s)
- R S Chhabra
- National Institute of Environmental Health Sciences, 111 Alexander Drive, P.O. Box 12233, Research Triangle Park, North Carolina 27709, USA.
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Hooth MJ, Deangelo AB, George MH, Gaillard ET, Travlos GS, Boorman GA, Wolf DC. Subchronic sodium chlorate exposure in drinking water results in a concentration-dependent increase in rat thyroid follicular cell hyperplasia. Toxicol Pathol 2001; 29:250-9. [PMID: 11421493 DOI: 10.1080/019262301317052530] [Citation(s) in RCA: 37] [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: 10/16/2022]
Abstract
Chlorine dioxide (ClO2) is an effective drinking water disinfectant, but sodium chlorate (NaClO3) has been identified as a potentially harmful disinfection by-product. Studies were performed to describe the development of thyroid lesions in animals exposed to NaClO3 in the drinking water. Male and female F344 rats and B6C3F1 mice were exposed to 0, 0.125, 0.25, 0.5, 1.0, or 2.0 g/L NaClO3 for 21 days. Additional male F344 rats were exposed to 0, 0.001. 0.01. 0.1, 1.0. or 2.0 g/L NaClO3 for 90 days. Female F344 rats were exposed to 0, 0.5, 1.0, 2.0, 4.0, or 6.0 g/L of NaClO3 for 105 days. Thyroid tissues were processed by routine methods for light microscopic examination, and follicular cell hyperplasia was diagnosed using a novel method. Thyroid hormone levels were altered significantly after 4 and 21 days. NaClO, treatment induced a concentration-dependent increase in the incidence and severity of thyroid follicular cell hyperplasia. Male rats are more sensitive to the effects of NaClO3 treatment than females. Follicular cell hyperplasia was not present in male or female B6C3F1 mice. These data can be used to estimate the human health risk that would be associated with using ClO2, rather than chlorine, to disinfect drinking water.
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Affiliation(s)
- M J Hooth
- Environmental Carcinogenesis Division, US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Travlos GS, Wilson RE, Murrell JA, Chignell CF, Boorman GA. The effect of short intermittent light exposures on the melatonin circadian rhythm and NMU-induced breast cancer in female F344/N rats. Toxicol Pathol 2001; 29:126-36. [PMID: 11215676 DOI: 10.1080/019262301301418937] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 10/17/2022]
Abstract
We investigated the effects of altered endogenous nighttime melatonin concentrations on mammary tumor production in an N-nitroso-N-methylurea (NMU)-induced breast cancer model in female Fischer 344 (F344)/N rats. Experiments were designed 1) to evaluate whether short-duration intermittent exposures to light at night would affect the nocturnal rise of melatonin, resulting in a decrease in nighttime serum melatonin concentrations, 2) to evaluate whether any suppression of nighttime serum melatonin concentrations could be maintained for a period of weeks, and 3) to determine the effects of suppressed serum melatonin concentrations on the incidence and progression of NMU-induced breast cancer. In vivo studies were used to assess serum melatonin concentrations after 1 day and 2 and 10 weeks of nightly administration of short-duration intermittent light exposure at night and incidence of NMU-induced tumors. Five 1-minute exposures to incandescent light every 2 hours after the start of the dark phase of the light: dark cycle decreased the magnitude of the nocturnal rise of serum melatonin concentrations in rats by approximately 65%. After 2 weeks of nightly intermittent light exposures, an average decrease of the peak nighttime serum melatonin concentrations of approximately 35% occurred. The amelioration continued and, at 10 weeks, peak nighttime serum melatonin concentrations were still decreased, by approximately 25%. Because peak endogenous nighttime serum melatonin values could be moderately suppressed for at least 10 weeks, a 26-week NMU mammary tumor study was conducted. Serum melatonin concentrations and incidence, multiplicity, and weight of NMU-induced mammary tumors were assessed. A group of pinealectomized (Px) animals was also included in the tumor study. No effect on the development of mammary tumors in an NMU-induced tumor model in rats occurred when endogenous nighttime serum melatonin concentrations were moderately suppressed by short-duration intermittent light exposures at night. At necropsy, there were no alterations in mammary tumor incidence (28/40 NMU controls, 28/40 NMU + light, 31/40 NMU + Px), multiplicity (2.18 tumors/tumor-bearing NMU control, 1.89 NMU + light, 2.39 NMU + Px), or average tumor weight (1.20 g NMU control, 1.19 g NMU + light, 0.74 g NMU + Px). Tumor burden had no effect on the serum melatonin cycle. At 26 weeks, however, animals exposed to intermittent light at night exhibited approximately 3-fold higher serum melatonin concentrations as compared with controls. Additionally, rats that had been pinealectomized at 4 weeks of age had serum melatonin concentrations that were markedly higher than the expected baseline concentrations for pinealectomized rats (<15 pg/ml), suggesting the reestablishment of a melatonin cycle. This finding was unexpected and suggests that melatonin can be produced by an organ or tissue other than the pineal gland.
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Affiliation(s)
- G S Travlos
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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Nyska A, Maronpot RR, Long PH, Roycroft JH, Hailey JR, Travlos GS, Ghanayem BI. Disseminated thrombosis and bone infarction in female rats following inhalation exposure to 2-butoxyethanol. Toxicol Pathol 1999; 27:287-94. [PMID: 10356705 DOI: 10.1177/019262339902700304] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [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: 11/15/2022]
Abstract
Groups of 10 male and 10 female F344/N rats were exposed to 0, 31, 62.5, 125, 250, and 500 ppm of 2-butoxyethanol (BE) by inhalation, 6 hr/day, 5 days/wk, for 13 wk. Four moribund female rats from the 500 ppm group were sacrificed during the first 4 days of exposure, and 1 moribund female from the same group was sacrificed during week 5. Dark irregular mottling and/or loss of the distal tail were noted in sacrificed moribund rats. Similar gross lesions were noted in the terminally sacrificed females exposed to 500 ppm BE. Histologic changes noted in the day 4 sacrificed moribund rats included disseminated thrombosis involving the coccygeal vertebrae, cardiac atrium, lungs, liver, pulp of the incisor teeth, and the submucosa of the anterior section of the nasal cavity. Alterations noted in coccygeal vertebrae from the 500 ppm sacrificed moribund rats included ischemic necrosis and/or degeneration of bone marrow cells, bone-lining cells, osteocytes (within cortical and trabecular bone), and chondrocytes (both articular and growth plate), changes that are consistent with an infarction process. The moribund female rat that was sacrificed during week 5 and those female rats treated with 500 ppm and sacrificed following 13 wk of treatment lacked thrombi, but they had coccygeal vertebral changes consistent with prior infarction and transient or complete bone growth arrest. No bone lesions or thrombi were noted in the male rats treated with the same doses of BE. In conclusion, exposure to 500 ppm BE vapors caused acute disseminated thrombosis and bone infarction in female rats. Possible pathogenic mechanisms are discussed.
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Affiliation(s)
- A Nyska
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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van Birgelen AP, Hébert CD, Wenk ML, Grimes LK, Chapin RE, Travlos GS, Mahler J, Bucher JR. Toxicity of 3,3',4,4'-tetrachloroazoxybenzene in rats and mice. Toxicol Appl Pharmacol 1999; 156:206-21. [PMID: 10222313 DOI: 10.1006/taap.1999.8647] [Citation(s) in RCA: 6] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The toxicity of 3,3',4,4'-tetrachloroazoxybenzene (TCAOB) was evaluated in 13-week gavage studies in male and female F344/N rats and B6C3F1 mice. In addition to histopathology, evaluations included clinical chemistry, hematology, thyroid hormone analyses, and effects on sperm morphology and estrous cycle length. Groups of 10 rats and 10 mice of each sex were exposed to TCAOB at dose levels of 0, 0.1, 1, 3, 10, or 30 mg/kg 5 days a week for 13 weeks. In the rat studies, the major effects included death in the 30 mg TCAOB/kg dose group; at lower exposure levels, a decrease in body weight gain, a decrease in thymus weight, an increase in liver weight, an increase in hematopoietic cell proliferation in the spleen and liver, a responsive anemia, a decrease in platelet counts, a chronic active inflammation of the vasculature in the lung, an increase in cardiomyopathy, hyperplasia of the forestomach, and a marked decrease in circulating thyroxine concentrations were observed. In male rats a decrease in sperm motility in the epididymides was observed. In addition, in female rats an increase in lung, spleen, kidney, and heart weights and nephropathy was observed. Furthermore, the estrous cycle length was increased. In the mouse studies, the major effects for males and females included a decrease in thymus weights, an increase in liver and kidney weights, centrilobular hypertrophy in the liver, hematopoietic cell proliferation, hyperplasia of the forestomach, and dilatation of hair follicles. The spectrum of effects in both rats and mice after exposure to TCAOB indicates that dioxin-like effects occur in addition to effects that have not been observed with dioxin-like compounds. No no-observed-adverse-effect level was reached in male or female rats or mice.
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Affiliation(s)
- A P van Birgelen
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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van Birgelen AP, Hébert CD, Wenk ML, Grimes LK, Chapin RE, Mahler J, Travlos GS, Bucher JR. Toxicity of 3,3',4,4'-tetrachloroazobenzene in rats and mice. Toxicol Appl Pharmacol 1999; 156:147-59. [PMID: 10198280 DOI: 10.1006/taap.1999.8640] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 11/22/2022]
Abstract
The toxicity of 3,3',4,4'-tetrachloroazobenzene (TCAB) was evaluated in 13-week gavage studies in male and female F344/N rats and B6C3F1 mice. In addition to histopathology, evaluations included clinical chemistry, hematology, thyroid hormone analyses, and reproductive parameters. Groups of 10 rats and 10 mice of each sex were exposed to TCAB at dose levels of 0, 0.1, 1, 3, 10, or 30 mg/kg for 5 days a week for 13 weeks. In the rat studies, the major effects for both males and females included a 10% decrease in terminal body weight at 30 mg/kg/day, an increase in hematopoietic cell proliferation in the spleen at 10 and 30 mg/kg/day, and a responsive anemia at 10 and 30 mg/kg/day. A 15 to 30% decrease in platelet counts and a 20 to 40% decrease in thymus weights was observed at 10 and 30 mg/kg/day. An increase in liver weight up to 15% was found at 3 mg/kg/day and higher doses in males and at 10 and 30 mg/kg/day in females, respectively. An increase in spleen weights up to 15% was observed at 10 and 30 mg/kg/day in males and at 30 mg/kg/day in females. A marked decrease in circulating total thyroxine (TT4) was found in both males and females at all dose levels tested. TT4 could hardly be detected at 10 and 30 mg TCAB/kg/day. In addition, hyperplasia of the forestomach was increased at 3 mg/kg/day and higher doses in males and at 30 mg/kg/day in females. In the mouse studies, an increase in liver and spleen weight was observed up to approximately 25% in both males and females at 10 and 30 mg/kg/day. Hyperplasia of the forestomach was observed at 1 mg/kg/day and higher doses in both males and females. In males, a 30% decrease in thymus weights at 30 mg/kg/day and a 60% decrease in epididymal sperm density at 3 and 30 mg/kg/day was observed. Also in males, centrilobular hypertrophy of hepatocytes and an increase in hematopoietic cell proliferation in the spleen was observed at 3 mg/kg/day and higher doses. Based on the current study and information in the literature, TCAB has dioxin-like properties. Comparison of the effects of TCAB in the present study and in the literature to those with 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) indicates that TCAB is from two to six orders of magnitude less potent than TCDD depending on the end point.
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Affiliation(s)
- A P van Birgelen
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA.
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Abstract
Melatonin, an indolic pineal hormone, is produced primarily at night in mammals and is important in controlling biological rhythms. Previous research suggested that melatonin can attenuate proliferation in the estrogen-responsive MCF-7 breast cancer cell line. We tested whether these anti-proliferative effects may have physiological consequences upon two estrogen-responsive cell lines, MCF-7 (a breast cancer cell line) and BG-1 (an ovarian adenocarcinoma cell line). Melatonin (10(-9)-10(-5) M) attenuated proliferation of MCF-7 and BG-1 cells by >20% in the absence of estrogen. However, 17beta-estradiol exposure negated the ability of melatonin to inhibit proliferation. To substantiate this finding, cells were estrogen starved followed by multiple treatments with estradiol and melatonin. Melatonin did not inhibit estradiol-stimulated proliferation under this protocol. Estradiol increased MCF-7 and BG-1 cell cycle transition from G1 to S phase, however, melatonin did not inhibit this transition nor did it down-regulate estradiol-induced pS2 mRNA levels measured by northern blotting, further indicating that melatonin was unable to attenuate estradiol-induced proliferation and gene expression. We also examined the effects of melatonin on estradiol-induced proliferation in MCF-7 cell xenografts in athymic nude mice. Melatonin at a dose 28 times greater than 17beta-estradiol did not inhibit estradiol-induced proliferation in vivo. Furthermore, pinealectomy did not increase proliferation. Therefore, we conclude that melatonin does not directly inhibit estradiol-induced proliferation.
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Affiliation(s)
- W S Baldwin
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Qu W, Rippe RA, Ma J, Scarborough P, Biagini C, Fiedorek FT, Travlos GS, Parker C, Zeldin DC. Nutritional status modulates rat liver cytochrome P450 arachidonic acid metabolism. Mol Pharmacol 1998; 54:504-13. [PMID: 9730909 DOI: 10.1124/mol.54.3.504] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Alterations in nutritional status affect hepatic cytochrome P450 levels. Since cytochromes P450 participate in the metabolism of arachidonic acid, we hypothesized that changes in liver P450 arachidonic acid metabolism occur during fasting and refeeding. Male Fisher 344 rats were either fed, fasted 48 hr (F48), fasted 48 hr and then refed 6 hr (F48/R6), or fasted 48 hr and then refed 24 hr (F48/R24). F48 rats had reduced body weight, increased plasma beta-hydroxybutyrate, and reduced plasma insulin compared with the other groups. Although there was no significant change in total liver P450 content, there was a significant 20%, 48%, and 24% reduction in total hepatic microsomal arachidonic acid metabolism in F48, F48/R6, and F48/R24 rats, respectively, compared with fed rats. Epoxygenase activity decreased by 28%, 51%, and 26% in F48, F48/R6, and F48/R24 rats, respectively. In contrast, omega-1 hydroxylase activity increased by 126% in F48 rats compared with fed rats. Immunoblotting revealed that levels of CYP2C11 protein were markedly reduced, whereas levels of CYP2E1 protein were markedly increased in the F48 and F48/R6 groups. In contrast, levels of CYP1A1, CYP1A2, CYP2B1, CYP2J3, CYP4A1, and CYP4A3 were unchanged with fasting/refeeding. Northern blots revealed that levels of CYP2C11 mRNAs were decreased, whereas CYP2E1 mRNAs were increased in F48 and F48/R6 rats. Recombinant CYP2C11 metabolized arachidonic acid primarily to epoxides with preference for the 14(S),15(R)-, 11(R), 12(S)-, and 8(S),9(R)- epoxyeicosatrienoic acid enantiomers. We conclude that (1) nutritional status affects hepatic microsomal arachidonic acid metabolism, (2) reduced epoxygenase activity in F48 and F48/R6 rats is accompanied by decreased levels of CYP2C11, (3) increased omega-1 hydroxylase activity is accompanied by augmented levels of CYP2E1, and (4) the effects of fasting on CYP2C11 and CYP2E1 expression occur at the pretranslational level.
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Affiliation(s)
- W Qu
- Laboratory of Pulmonary Pathobiology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA
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