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Collins B, Slade D, Aillon K, Stout M, Betz L, Waidyanatha S, Ryan K. Plasma concentrations of tris(1-chloro-2-propyl) phosphate and a metabolite bis(2-chloroisopropyl) 1-carboxyethyl phosphate in Sprague-Dawley rats and B6C3F1/N mice from a chronic study of tris(chloropropyl) phosphate via feed. Toxicol Rep 2022; 9:690-698. [PMID: 35433273 PMCID: PMC9010517 DOI: 10.1016/j.toxrep.2022.03.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 11/16/2022] Open
Abstract
Tris(chloropropyl) phosphate (TCPP) is an organophosphorus flame retardant and plasticizer used in manufacturing and multiple consumer products. Commercial TCPP is a ubiquitous environmental contaminant and TCPP or its metabolites have been detected in human plasma and urine. In response to the demonstrated widespread human exposure and lack of toxicity data, the Division of the National Toxicology Program is investigating the chronic toxicity of TCPP following perinatal exposure in HSD:Sprague Dawley®SD® (HSD) rats (up to 20,000 ppm) and adult exposure in B6C3F1/N mice (females, up to 10,000 ppm; males up to 5000 ppm) to TCPP via feed. Systemic exposure and bioaccumulation were assessed by measuring plasma concentrations of tris(1-chloro-2-propyl)phosphate (TCIPP), the most abundant TCPP isomer. TCIPP concentrations in TCPP-exposed rats and mice ranged from 3.43 to 1180 ng/mL and increased with exposure concentration at all time points. No sex differences were observed in rats, but male mice had higher TCIPP concentrations than females. TCIPP did not bioaccumulate in rats or mice over the course of the study. Low TCIPP concentrations were seen in some control rats and mice that were attributed to background TCPP present during sample collection, preparation and/or analysis. Bis(2-chloroisopropyl) 1-carboxyethyl phosphate (BCPCP), a TCPP metabolite, was quantified in plasma from control and selected exposed animals. Results showed increases in BCPCP concentration that were proportional to exposure concentration in rats and mice at concentrations much higher than TCIPP, indicating that BCPCP might be a more suitable biomarker of TCPP exposure. Tris(chloropropyl)phosphate (TCPP) has widespread environmental exposure. We measured plasma levels of TCPP following chronic feed exposure in rodents. The most abundant isomer of TCPP (TCIPP) increased with exposure with no accumulation. Bis(2-chloroisopropyl)1-carboxyethyl phosphate (BCPCP) levels were higher than TCIPP. Metabolite BCPCP may be a more suitable biomarker for TCPP exposure.
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Collins BJ, Kerns SP, Aillon K, Mueller G, Rider CV, DeRose EF, London RE, Harnly JM, Waidyanatha S. Correction to: Comparison of phytochemical composition of G. biloba extracts using a combination of non-targeted and targeted analytical approaches. Anal Bioanal Chem 2021; 413:6449-6450. [PMID: 34402966 DOI: 10.1007/s00216-021-03594-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.
| | | | | | - Geoffrey Mueller
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Eugene F DeRose
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Robert E London
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - James M Harnly
- U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Methods and Applications Food Composition Lab, Beltsville, MD, 20705, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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Watson ATD, Sutherland VL, Cunny H, Miller-Pinsler L, Furr J, Hebert C, Collins B, Waidyanatha S, Smith L, Vinke T, Aillon K, Xie G, Shockley KR, McIntyre BS. Postnatal Effects of Gestational and Lactational Gavage Exposure to Boric Acid in the Developing Sprague Dawley Rat. Toxicol Sci 2021; 176:65-73. [PMID: 32392305 DOI: 10.1093/toxsci/kfaa061] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Human exposure to boron occurs primarily through diet and drinking water sources. Animal studies have found that reduced fetal weight following gestational exposure to boron (as boric acid) is the most sensitive toxicological effect. However, recent studies suggest that newborns in areas with elevated boron in drinking water may receive levels of exposure that exceed the U.S. EPA oral reference dose for B. Currently, there are no data to inform a boron risk assessment accounting for this developmental window. To address this knowledge gap, the National Toxicology Program evaluated developmental toxicity following pre- and postnatal boron exposure. Time-mated female Sprague Dawley (Hsd: Sprague Dawley SD) rats were administered 0-20 mg B/kg/day (as boric acid) via gavage from gestation day 6 to 21; offspring were dosed via gavage at the same respective dose level from postnatal day (PND) 1 to 28. There were no dose-related effects on dam bodyweight, bodyweight gain, or feed consumption. Clinical findings were limited to low incidences of umbilical hernia in the 20 mg B/kg pups which resolved by study completion. Pup plasma boron concentrations increased in dose-proportional manner and were similar between PND 4 and PND 28. Postnatal weight gain was significantly reduced at 20 mg B/kg, with male and female pups weighing 23% less than the controls on PND 28. These findings demonstrate that postnatal growth in the Sprague Dawley rat is sensitive to boron exposure and highlights the importance of evaluating the potential toxicity of agents with known human exposures during early life stages.
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Affiliation(s)
- AtLee T D Watson
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Vicki L Sutherland
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Helen Cunny
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Lutfiya Miller-Pinsler
- †Toxicology and Pathology Services, Southern Research Institute, Birmingham, Alabama 35205
| | - Johnathan Furr
- †Toxicology and Pathology Services, Southern Research Institute, Birmingham, Alabama 35205
| | - Charles Hebert
- †Toxicology and Pathology Services, Southern Research Institute, Birmingham, Alabama 35205
| | - Brad Collins
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Suramya Waidyanatha
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | | | | | | | - Guanhua Xie
- §Social and Scientific Systems, Durham, North Carolina 27703
| | - Keith R Shockley
- ¶Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Barry S McIntyre
- *Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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Waidyanatha S, Collins BJ, Cunny H, Aillon K, Riordan F, Turner K, McBride S, Betz L, Sutherland V. An investigation of systemic exposure to bisphenol AF during critical periods of development in the rat. Toxicol Appl Pharmacol 2021; 411:115369. [PMID: 33338515 PMCID: PMC7821698 DOI: 10.1016/j.taap.2020.115369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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] [Received: 06/25/2020] [Revised: 11/20/2020] [Accepted: 12/13/2020] [Indexed: 11/22/2022]
Abstract
Due to structural similarity to bisphenol A and lack of safety data, the National Toxicology Program (NTP) is evaluating the potential toxicity of bisphenol AF (BPAF) in rodent models. The current investigation reports the internal exposure data for free (unconjugated BPAF) and total (free and conjugated forms) BPAF during critical stages of development following perinatal dietary exposure in Hsd:Sprague Dawley®SD® rats to 0 (vehicle control), 338, 1125, and 3750 ppm BPAF from gestation day (GD) 6 to postnatal day (PND) 28. Free and total BPAF concentrations in maternal plasma at GD 18, PND 4, and PND 28 increased with the exposure concentration; free BPAF concentrations were ≤ 1.61% those of total BPAF demonstrating extensive first pass metabolism of BPAF following dietary exposure in adults. Free and total BPAF were quantified in GD 18 fetuses and PND 4 pups with free concentrations 11.7-53.4% that of corresponding total concentrations. In addition, free concentrations were higher (130-571%) and total concentrations were lower (1.71-7.23%) than corresponding concentrations in dams, demonstrating either preferential transfer of free BPAF and/or inability of fetuses and pups to conjugate BPAF. Free and total concentrations in PND 28 pups were similar to maternal concentrations demonstrating direct exposure of pups via feed and that conjugating enzymes are developed in PND 28 pups. In conclusion, these data demonstrate considerable gestational and lactational transfer of parent aglycone from the mother to offspring. Since the ontogeny of conjugating enzymes in humans is similar to that of rodents, the data from rodent BPAF studies may be useful in predicting human risk from exposure to BPAF.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Helen Cunny
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | - Katie Turner
- RTI International, Discovery Sciences, Research Triangle, NC, USA
| | | | - Laura Betz
- Social and Scientific Systems, Durham, NC, USA
| | - Vicki Sutherland
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Waidyanatha S, Black SR, Croutch CR, Collins BJ, Silinski MAR, Kerns S, Sutherland V, Robinson VG, Aillon K, Fernando RA, Mutlu E, Fennell TR. Comparative toxicokinetics of bisphenol S and bisphenol AF in male rats and mice following repeated exposure via feed. Xenobiotica 2020; 51:210-221. [PMID: 32985913 DOI: 10.1080/00498254.2020.1829171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 02/07/2023]
Abstract
We investigated the plasma toxicokinetic behavior of free (parent) and total (parent and conjugated forms) of bisphenol S (BPS) and bisphenol AF (BPAF) in plasma of adult male rats and mice following exposure via feed for 7 days to BPS (338, 1125, and 3375 ppm) or BPAF (338, 1125, and 3750 ppm). In rats, the exposure concentration-normalized maximum concentration [Cmax/D (ng/mL)/(ppm)] and area under the concentration time curve [AUC/D (h × ng/mL)/(ppm)] for free was higher for BPS (Cmax/D: 0.476-1.02; AUC/D: 3.58-8.26) than for BPAF (Cmax/D: 0.017-0.037; AUC/D:0.196-0.436). In mice, the difference in systemic exposure parameters between free BPS (Cmax/D: 0.376-0.459; AUC/D: 1.52-2.54) and free BPAF (Cmax/D: 0.111-0.165; AUC/D:0.846-1.09) was marginal. Elimination half-lives for free analytes (4.41-10.4 h) were comparable between species and analogues. When systemic exposure to free analyte was compared between species, in rats, BPS exposure was slightly higher but BPAF exposure was much lower than in mice. BPS and BPAF were highly conjugated; total BPS AUC values (rats ≥18-fold, mice ≥17-fold) and BPAF (rats ≥127-fold, mice ≥16-fold) were higher than corresponding free values. Data demonstrated that there are analogue and species differences in the kinetics of BPS and BPAF.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Sherry R Black
- Discovery Sciences, RTI International, Research Triangle Park, NC, USA
| | | | - Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | - Vicki Sutherland
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Veronica G Robinson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Reshan A Fernando
- Discovery Sciences, RTI International, Research Triangle Park, NC, USA
| | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Timothy R Fennell
- Discovery Sciences, RTI International, Research Triangle Park, NC, USA
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Collins BJ, Kerns SP, Aillon K, Mueller G, Rider CV, DeRose EF, London RE, Harnly JM, Waidyanatha S. Comparison of phytochemical composition of Ginkgo biloba extracts using a combination of non-targeted and targeted analytical approaches. Anal Bioanal Chem 2020; 412:6789-6809. [PMID: 32865633 PMCID: PMC7496025 DOI: 10.1007/s00216-020-02839-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/26/2020] [Accepted: 07/23/2020] [Indexed: 01/23/2023]
Abstract
Ginkgo biloba extract (GbE) is a dietary supplement derived from an ethanolic extract of Ginkgo biloba leaves. Unfinished bulk GbE is used to make finished products that are sold as dietary supplements. The variable, complex composition of GbE makes it difficult to obtain consistent toxicological assessments of potential risk. The National Toxicology Program (NTP) observed hepatotoxicity in its rodent studies of a commercially available, unfinished GbE product, but the application of these results to the broader GbE supplement market is unclear. Here, we use a combination of non-targeted and targeted chromatographic and spectrophotometric methods to obtain profiles of 24 commercially available finished GbE products and unfinished standardized and unstandardized extracts with and without hydrolysis, then used principal component analysis to group unfinished products according to their similarity to each other and to National Institute of Standards and Technology (NIST) standard reference materials (SRM), and the finished products. Unfinished products were grouped into those that were characteristic and uncharacteristic of standardized GbE. Our work demonstrates that different analytical approaches produced similar classifications of characteristic and uncharacteristic products in unhydrolyzed samples, but the distinctions largely disappeared once the samples were hydrolyzed. Using our approach, the NTP GbE was most similar to two unfinished GbE products classified as characteristic, finished products, and the NIST GbE SRM. We propose that a simple analysis for the presence, absence, or amounts of compounds unique to GbE in unhydrolyzed samples could be sufficient to determine a sample’s authenticity. Graphical abstract![]()
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Affiliation(s)
- Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.
| | | | | | - Geoffrey Mueller
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Eugene F DeRose
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Robert E London
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - James M Harnly
- U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Methods and Applications Food Composition Lab, Beltsville, MD, 20705, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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Waidyanatha S, Black SR, Aillon K, Collins B, Patel PR, Riordan F, Sutherland V, Robinson VG, Fernando R, Fennell TR. Toxicokinetics and bioavailability of bisphenol AF following oral administration in rodents: A dose, species, and sex comparison. Toxicol Appl Pharmacol 2019; 373:39-47. [PMID: 31022493 DOI: 10.1016/j.taap.2019.04.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 01/18/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 10/26/2022]
Abstract
We investigated the toxicokinetics and bioavailability of bisphenol AF (BPAF) in male and female Harlan Sprague Dawley rats and B6C3F1/N mice following a single gavage administration of 34, 110, or 340 mg/kg. A validated analytical method was used to quantitate free (unconjugated parent) and total (unconjugated and conjugated) BPAF in plasma. BPAF was rapidly absorbed in rats with the maximum plasma concentration, Cmax, of free BPAF reached at ≤2.20 h. BPAF was cleared rapidly with a plasma elimination half-life of ≤3.35 h. Cmax and the area under the concentration versus time curve, AUC0-∞, increased proportionally to the dose. Total BPAF Cmax was reached ≤1.07 h in rats with both Cmax (≥27-fold) and AUC0-∞ (≥52-fold) much higher than corresponding free values demonstrating rapid and extensive conjugation of BPAF following oral administration. Absorption of BPAF following a 34 mg/kg gavage dose in mice was more rapid than in rats with free BPAF Cmax reached ≤0.455 h. Free BPAF was cleared rapidly in mice with an elimination half-life of ≤4.22 h. Similar to rats, total BPAF was much higher than corresponding free BPAF. There was no apparent sex-related effect in plasma toxicokinetic parameters of free or total BPAF in mice and rats. Bioavailability in rats was ~ 1% with no apparent dose-related effect. Bioavailability in mice was slightly higher than in rats (male ~ 6%, female 3%). These data demonstrate that BPAF was rapidly absorbed following gavage administration in rodents, rapidly and extensively conjugated with low bioavailability.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America.
| | - Sherry R Black
- RTI International, Discovery Sciences, Research Triangle Park, NC, United States of America
| | | | - Brad Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - Purvi R Patel
- RTI International, Discovery Sciences, Research Triangle Park, NC, United States of America
| | | | - Vicki Sutherland
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - Veronica Godfrey Robinson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States of America
| | - Reshan Fernando
- RTI International, Discovery Sciences, Research Triangle Park, NC, United States of America
| | - Timothy R Fennell
- RTI International, Discovery Sciences, Research Triangle Park, NC, United States of America
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Collins BJ, Slade D, Ryan K, Mathias R, Shan A, Algaier J, Aillon K, Waidyanatha S. Development and Validation of an Analytical Method to Quantitate Tris(chloroisopropyl)phosphate in Rat and Mouse Plasma using Gas Chromatography with Flame Photometric Detection. J Anal Toxicol 2019; 43:36-44. [PMID: 30060005 DOI: 10.1093/jat/bky048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Indexed: 11/14/2022] Open
Abstract
Tris(chloropropyl)phosphate (TCPP) is an organophosphorus flame retardant (OPFR) and plasticizer increasingly used in consumer products and as a replacement for brominated flame retardants. Commercially available TCPP is a mixture of four structural isomers the most abundant of which is tris(1-chloro-2-propyl)phosphate (TCPP-1). Although there is a widespread use of TCPP and potential for human exposure, there is limited data on the safety or toxicity of TCPP. The National Toxicology Program is conducting long-term studies to examine the toxicity of the TCPP in rats after lifetime exposure, including perinatal oral exposure. Quantitative estimates of internal dose are essential to interpret toxicological findings in rodents. To aid in this, a method was fully validated to quantitate the most abundant isomer, TCPP-1, in female Harlan Sprague Dawley (HSD) rat and B6C3F1 mouse plasma with partial validation in male rat plasma, and male and female mouse plasma. The method used protein precipitation using trichloroacetic acid followed by the extraction with toluene, and analysis by gas chromatography with flame photometric detection. The performance of the method was evaluated over 5-70 ng TCPP-1/mL plasma. The method was linear (r ≥ 0.99), accurate (inter-day relative error: ≤ ± -7.2) and precise (inter-batch relative standard deviation: ≤27.5%). The validated method has lower limits of quantitation and detection of ~5 and 0.9 ng/mL, respectively, in female HSD rat plasma and can be used on samples as small as 50 μL demonstrating the applicability to plasma samples from toxicology studies.
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Affiliation(s)
- B J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, 111 Alexander Dr., Research Triangle Park, NC, USA
| | - D Slade
- MRIGlobal, 425 Volker Boulevard, Kansas City, MO, USA
| | - K Ryan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, 111 Alexander Dr., Research Triangle Park, NC, USA
| | - R Mathias
- MRIGlobal, 425 Volker Boulevard, Kansas City, MO, USA
| | - A Shan
- MRIGlobal, 425 Volker Boulevard, Kansas City, MO, USA
| | - J Algaier
- MRIGlobal, 425 Volker Boulevard, Kansas City, MO, USA
| | - K Aillon
- MRIGlobal, 425 Volker Boulevard, Kansas City, MO, USA
| | - S Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, 111 Alexander Dr., Research Triangle Park, NC, USA
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