1
|
Walter KM, Culp WTN, Giuffrida MA, Amsellem P, Wallace ML, Grimes JA, Wustefeld-Janssens B, O'Neill M, Withers SS, Shannon D, Lapsley J, Tuohy J, Hixson H, Lux CN, Matz B, Selmic LE, McGrath A, Griffin MA, Mayhew PD, Steffey MA, Balsa IM, Rebhun RB, Kent MS. Treatment of retroperitoneal sarcoma results in improved outcomes. J Am Vet Med Assoc 2024:1-9. [PMID: 38382204 DOI: 10.2460/javma.23.09.0507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/16/2024] [Indexed: 02/23/2024]
Abstract
OBJECTIVE To report the clinical characteristics, treatments, and outcomes in a cohort of dogs with histologically confirmed retroperitoneal sarcoma (RPS) and to identify potential variables of prognostic significance. ANIMALS 46 client-owned dogs from 10 clinics with histopathologic diagnosis of a sarcoma originating from the retroperitoneal space. METHODS Medical records were retrospectively reviewed to obtain information regarding clinical characteristics, treatments, and outcomes. Recorded variables were analyzed to report descriptive data for all cases and overall survival time. Multivariate analysis was utilized to evaluate prognostic factors for overall survival. RESULTS Hemangiosarcoma was the most common histologic subtype diagnosed (76.1%). Cytoreductive and curative intent surgical excision of the RPS was attempted in 12 and 22 dogs, respectively; 12 dogs underwent no surgery or had an exploratory laparotomy with incisional biopsy only. Nineteen dogs received adjuvant chemotherapy, either injectable or metronomic, and 1 dog received adjuvant radiation therapy. Fourteen of the 34 (41.2%) surgically treated dogs developed evidence of local recurrence, but there was no difference in local recurrence when comparing dogs categorized as curative intent versus cytoreductive surgery. The median overall survival time was 238 days. On multivariable analysis, treatment approach was associated with survival with surgical excision (vs palliative treatment) and adjuvant chemotherapy following surgery being protective against death. A diagnosis of hemangiosarcoma was associated with a greater hazard of death. CLINICAL RELEVANCE This study demonstrates a substantially greater survival time than previously published and suggests a survival benefit from surgical excision and adjuvant chemotherapy.
Collapse
Affiliation(s)
- Kyla M Walter
- 1Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - William T N Culp
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Michelle A Giuffrida
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Pierre Amsellem
- 3College of Veterinary Medicine, University of Minnesota, Saint Paul, MN
| | - Mandy L Wallace
- 4College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Janet A Grimes
- 4College of Veterinary Medicine, University of Georgia, Athens, GA
| | | | - Meaghan O'Neill
- 5College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO
| | - Sita S Withers
- 6School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Dylan Shannon
- 6School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Janis Lapsley
- 7College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Joanne Tuohy
- 8Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Haleigh Hixson
- 8Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | - Cassie N Lux
- 9College of Veterinary Medicine, University of Tennessee, Knoxville, TN
| | - Brad Matz
- 10College of Veterinary Medicine, Auburn University, Auburn, AL
| | - Laura E Selmic
- 11College of Veterinary Medicine, The Ohio State University, Columbus, OH
| | - Alysha McGrath
- 11College of Veterinary Medicine, The Ohio State University, Columbus, OH
| | - Maureen A Griffin
- 12School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Philipp D Mayhew
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Michele A Steffey
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Ingrid M Balsa
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Robert B Rebhun
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| | - Michael S Kent
- 2Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA
| |
Collapse
|
2
|
Walter KM, Singh L, Singh V, Lein PJ. Investigation of NH3 as a selective thyroid hormone receptor modulator in larval zebrafish (Danio rerio). Neurotoxicology 2021; 84:96-104. [PMID: 33745965 DOI: 10.1016/j.neuro.2021.03.003] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 03/07/2021] [Accepted: 03/15/2021] [Indexed: 11/17/2022]
Abstract
Thyroid hormones (THs) are essential for normal vertebrate development and diverse environmental chemicals are hypothesized to cause developmental toxicity by disrupting TH-mediated signaling. The larval zebrafish (Danio rerio) is an emerging in vivo model of developmental TH disruption; however, the effects of TR antagonism have not yet been studied in zebrafish. NH3, generally considered a potent and specific thyroid hormone receptor (TR) antagonist, has been used in rodents and Xenopus laevis to characterize phenotypes of TR antagonism. The objective of this study is to determine the effects of NH3 on endpoints previously determined to be TH-sensitive in larval zebrafish, specifically teratology and mortality, photomotor behavior, and mRNA expression of TH signaling genes. Zebrafish embryos were exposed to NH3 via static waterborne exposure at concentrations ranging from 0.001 to 10 μM beginning at 6 h post-fertilization (hpf) through 5 days post fertilization (dpf). Significant mortality and teratogenesis was observed at 3, 4, and 5 dpf in zebrafish exposed to NH3 at 10 μM. At concentrations that did not cause significant mortality, NH3 did not exert a consistent antagonistic effect on photomotor behavior assays or mRNA expression when administered alone or in the presence of exogenous T4. Rather, depending on the NH3 concentration and larval age NH3 decreased or increased swimming triggered by transition from light to dark. Similarly, inconsistent antagonistic and agonistic effects on mRNA expression of TH signaling genes were noted following treatment with NH3 alone. NH3 did inhibit T4 (30 nM)-induced gene expression; however, this was only consistently observed at a concentration of NH3 (10 μM) that also caused significant mortality. Collectively, these results suggest that NH3 does not act solely as a TR antagonist in larval zebrafish, but instead exhibits complex modulatory effects on TR activity. These data support the hypothesis that NH3 is a selective thyroid hormone receptor modulator. Further studies of NH3 interactions with the zebrafish thyroid hormone receptor are required to characterize the activity of NH3 in target tissues of the larval zebrafish at the molecular level, highlighting the importance of characterizing NH3 effects in specific models of TH-disruption to better interpret its actions in mechanistic screens of environmental chemicals for TH action.
Collapse
Affiliation(s)
- Kyla M Walter
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Latika Singh
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, United States.
| | - Vikrant Singh
- Department of Pharmacology, University of California, Davis, Davis, CA, 95616, United States.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| |
Collapse
|
3
|
Walter KM, Dach K, Hayakawa K, Giersiefer S, Heuer H, Lein PJ, Fritsche E. Ontogenetic expression of thyroid hormone signaling genes: An in vitro and in vivo species comparison. PLoS One 2019; 14:e0221230. [PMID: 31513589 PMCID: PMC6742404 DOI: 10.1371/journal.pone.0221230] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/01/2019] [Indexed: 02/07/2023] Open
Abstract
Thyroid hormone (TH) is essential for brain development. While disruption of TH signaling by environmental chemicals has been discussed as a mechanism of developmental neurotoxicity (DNT) for more than a decade, there remains a paucity of information linking specific TH disrupting chemicals to adverse neurodevelopmental outcomes. This data gap reflects, in part, the fact that the molecular machinery of TH signaling is complex and varies according to cell type and developmental time. Thus, establishing a baseline of the ontogenetic profile of expression of TH signaling molecules in relevant cell types is critical for developing in vitro and alternative systems-based models for screening TH disrupting chemicals for DNT. Here, we characterize the transcriptomic profile of molecules critical to TH signaling across three species-human, rat, and zebrafish-in vitro and in vivo across different stages of neurodevelopment. Our data indicate that while cultured human and rat neural progenitor cells, primary cultures of rat cortical cells, and larval zebrafish all express a fairly comprehensive transcriptome of TH signaling molecules, the spatiotemporal expression profiles as well as the responses to TH vary across species and developmental stages. The data presented here provides a roadmap for identifying appropriate in vitro and in simpler systems-based models for mechanistic studies and screening of chemicals that alter neurodevelopment via interference with TH action.
Collapse
Affiliation(s)
- Kyla M. Walter
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
| | - Katharina Dach
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
| | - Keri Hayakawa
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
| | - Susanne Giersiefer
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
| | - Heike Heuer
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
- Dept. Endocrinology, University Hospital Essen, Essen, Germany
| | - Pamela J. Lein
- Department of Molecular Biosciences, University of California-Davis, School of Veterinary Medicine, Davis, CA, United States of America
- * E-mail: (PJL); (EF)
| | - Ellen Fritsche
- IUF–Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany
- * E-mail: (PJL); (EF)
| |
Collapse
|
4
|
Walter KM, Miller GW, Chen X, Harvey DJ, Puschner B, Lein PJ. Changes in thyroid hormone activity disrupt photomotor behavior of larval zebrafish. Neurotoxicology 2019; 74:47-57. [PMID: 31121238 DOI: 10.1016/j.neuro.2019.05.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [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: 02/11/2019] [Revised: 05/12/2019] [Accepted: 05/17/2019] [Indexed: 12/12/2022]
Abstract
High throughput in vitro, in silico, and computational approaches have identified numerous environmental chemicals that interfere with thyroid hormone (TH) activity, and it is posited that human exposures to such chemicals are a contributing factor to neurodevelopmental disorders. However, whether hits in screens of TH activity are predictive of developmental neurotoxicity (DNT) has yet to be systematically addressed. The zebrafish has been proposed as a second tier model for assessing the in vivo DNT potential of TH active chemicals. As an initial evaluation of the feasibility of this proposal, we determined whether an endpoint often used to assess DNT in larval zebrafish, specifically photomotor behavior, is altered by experimentally induced hyper- and hypothyroidism. Developmental hyperthyroidism was simulated by static waterborne exposure of zebrafish to varying concentrations (3-300 nM) of thyroxine (T4) or triiodothyronine (T3) beginning at 6 h post-fertilization (hpf) and continuing through 5 days post-fertilization (dpf). Teratogenic effects and lethality were observed at 4 and 5 dpf in fish exposed to T4 or T3 at concentrations >30 nM. However, as early as 3 dpf, T4 (> 3 nM) and T3 (> 10 nM) significantly increased swimming activity triggered by sudden changes from light to dark, particularly during the second dark period (Dark 2). Conversely, developmental hypothyroidism, which was induced by treatment with 6-propyl-2-thiouracil (PTU), morpholino knockdown of the TH transporter mct8, or ablation of thyroid follicles in adult females prior to spawning, generally decreased swimming activity during dark periods, although effects did vary across test days. All effects of developmental hypothyroidism on photomotor behavior occurred independent of teratogenic effects and were most robust during Dark 2. Treatment with the T4 analog, Tetrac, restored photomotor response in mct8 morphants to control levels. Collectively, these findings suggest that while the sensitivity of photomotor behavior in larval zebrafish to detect TH disruption is influenced by test parameters, this test can distinguish between TH promoting and TH blocking activity and may be useful for assessing the DNT potential of TH-active chemicals.
Collapse
Affiliation(s)
- Kyla M Walter
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Galen W Miller
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Xiaopeng Chen
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Danielle J Harvey
- Department of Public Health Sciences University of California, Davis, School of Medicine, Davis, California 95616, United States.
| | - Birgit Puschner
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, United States.
| |
Collapse
|
5
|
Walter KM, Miller GW, Chen X, Yaghoobi B, Puschner B, Lein PJ. Effects of thyroid hormone disruption on the ontogenetic expression of thyroid hormone signaling genes in developing zebrafish (Danio rerio). Gen Comp Endocrinol 2019; 272:20-32. [PMID: 30448381 PMCID: PMC6331280 DOI: 10.1016/j.ygcen.2018.11.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 11/12/2018] [Accepted: 11/14/2018] [Indexed: 12/25/2022]
Abstract
Thyroid hormones (THs) regulate neurodevelopment, thus TH disruption is widely posited as a mechanism of developmental neurotoxicity for diverse environmental chemicals. Zebrafish have been proposed as an alternative model for studying the role of TH in developmental neurotoxicity. To realize this goal, it is critical to characterize the normal ontogenetic expression profile of TH signaling molecules in the developing zebrafish and determine the sensitivity of these molecules to perturbations in TH levels. To address these gaps in the existing database, we characterized the transcriptional profiles of TH transporters, deiodinases (DIOs), receptors (TRs), nuclear coactivators (NCOAs), nuclear corepressors (NCORs), and retinoid X receptors (RXRs) in parallel with measurements of endogenous TH concentrations and tshβ mRNA expression throughout the first five days of zebrafish development. Transcripts encoding these TH signaling components were identified and observed to be upregulated around 48-72 h post fertilization (hpf) concurrent with the onset of larval production of T4. Exposure to exogenous T4 and T3 upregulated mct8, dio3-b, trα-a, trβ, and mbp-a levels, and downregulated expression of oatp1c1. Morpholino knockdown of TH transporter mct8 and treatment with 6-propyl-2-thiouracil (PTU) was used to reduce cellular uptake and production of TH, an effect that was associated with downregulation of dio3-b at 120 hpf. Collectively, these data confirm that larval zebrafish express orthologs of TH signaling molecules important in mammalian development and suggest that there may be species differences with respect to impacts of TH disruption on gene transcription.
Collapse
Affiliation(s)
- Kyla M Walter
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| | - Galen W Miller
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| | - Xiaopeng Chen
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| | - Bianca Yaghoobi
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| | - Birgit Puschner
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA 95616, United States.
| |
Collapse
|
6
|
Chen X, Walter KM, Miller GW, Lein PJ, Puschner B. Simultaneous quantification of T4, T3, rT3, 3,5-T2 and 3,3'-T2 in larval zebrafish (Danio rerio) as a model to study exposure to polychlorinated biphenyls. Biomed Chromatogr 2018; 32:e4185. [PMID: 29314156 PMCID: PMC5980666 DOI: 10.1002/bmc.4185] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/15/2017] [Accepted: 12/20/2017] [Indexed: 01/28/2023]
Abstract
Environmental toxicants that interfere with thyroid hormone (TH) signaling can impact growth and development in animals and humans. Zebrafish represent a model to study chemically induced TH disruption, prompting the need for sensitive detection of THs. Simultaneous quantification of 3,3',5-triiodo-l-thyronine (T3), thyroxine (T4), 3,3',5'-triiodo-l-thyronine (rT3), 3,5-diiodo-l-thyronine (3,5-T2) and 3,3'-diiodo-l-thyronine (3,3'-T2) in zebrafish larvae was achieved by ultra-performance liquid chromatography-tandem mass spectrometry in positive ion mode. Solid-phase extraction with SampliQ cartridges and derivatization with 3 m hydrochloric acid in n-butanol reduced matrix effects. Derivatized compounds were separated on an Acquity UPLC BEH C18 column with mobile phases consisting of 0.1% acetic acid in deionized water and 0.1% acetic acid in methanol. The limits of detection ranged from 0.5 to 0.6 pg injected on column. The method was validated by evaluating recovery (77.1-117.2%), accuracy (87.3-123.9%) and precision (0.5-12.4%) using diluted homogenized zebrafish embryos spiked with all target compounds. This method was then applied to zebrafish larvae collected after 114 h of exposure to polychlorinated biphenyls (PCBs), including PCB 28, PCB 66 and PCB 95, or the technical mixture Aroclor 1254. Exposure to PCB 28 and PCB 95 increased the T4:T3 ratio and decreased the T3:rT3 ratio, demonstrating that this method can effectively detect PCB-induced alterations in THs.
Collapse
Affiliation(s)
| | | | | | | | - Birgit Puschner
- Birgit Puschner – Corresponding Author. phone: 530-752-6285, fax: 530-752-7690, (orcid.org/0000-0001-6765-5085)
| |
Collapse
|
7
|
Walter KM, Lin YP, Kass PH, Puschner B. Association of Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) with Hyperthyroidism in Domestic Felines, Sentinels for Thyroid Hormone Disruption. BMC Vet Res 2017; 13:120. [PMID: 28468659 PMCID: PMC5415813 DOI: 10.1186/s12917-017-1031-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 04/17/2017] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hyperthyroidism is the most common endocrine disorder observed in domestic felines; however, its etiology is largely unknown. Two classes of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known to interfere with thyroid hormone (TH) signaling and regulation; thus, it is postulated that they contribute to the etiopathogenesis of feline hyperthyroidism and pose a risk to humans and other species. In this case-control study, the concentrations of 13 PBDE and 11 PCB congeners were measured by gas chromatography mass spectrometry in serum or plasma samples from 20 hyperthyroid and 31 control cats in order to investigate the association between concentration of PBDE and PCB congeners and feline hyperthyroidism. Logistic regression analysis was used to determine whether elevated concentrations of individual congeners were associated with a higher risk of feline hyperthyroidism. RESULTS Hyperthyroid cats had higher concentrations of four PBDE congeners (BDE17, BDE100, BDE47, and BDE49) and five PCB congeners (PCB131, PCB153, PCB174, PCB180, and PCB196), compared to control cats. In addition, the sum of both PBDE and PCB congener concentrations were elevated in the hyperthyroid group compared to control cats; however, only the increased PCB concentrations were statistically significant. The sum total PBDE concentrations in our feline samples were approximately 50 times greater than concentrations previously reported in human populations from a geographically similar area, whereas sum total PCB concentrations were comparable to those previously reported in humans. CONCLUSIONS These observational findings support the hypothesis that PBDEs and PCBs may contribute to the etiopathogenesis of hyperthyroidism in felines. As domestic house cats are often exposed to higher concentrations of PBDEs than humans, they may serve as sentinels for the risk of TH disruption that these pollutants pose to humans and other species.
Collapse
Affiliation(s)
- Kyla M. Walter
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, 1089 Veterinary Medicine Dr., Davis, CA 95616 USA
| | - Yan-ping Lin
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, 1089 Veterinary Medicine Dr., Davis, CA 95616 USA
| | - Philip H. Kass
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, 1089 Veterinary Medicine Dr., Davis, CA 95616 USA
| | - Birgit Puschner
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, 1089 Veterinary Medicine Dr., Davis, CA 95616 USA
| |
Collapse
|
8
|
Bozorgmanesh R, Magdesian KG, Rhodes DM, Von Dollen KA, Walter KM, Moore CE, Puschner B, Woods LW, Torrisi K, Voss ED. Hemolytic anemia in horses associated with ingestion of Pistacia leaves. J Vet Intern Med 2015; 29:410-3. [PMID: 25619527 PMCID: PMC4858062 DOI: 10.1111/jvim.12532] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 09/29/2014] [Accepted: 11/25/2014] [Indexed: 11/28/2022] Open
Affiliation(s)
- R Bozorgmanesh
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, CA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Walter KM, Moore CE, Bozorgmanesh R, Magdesian KG, Woods LW, Puschner B. Oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis. J Vet Diagn Invest 2014; 26:821-6. [PMID: 25227420 DOI: 10.1177/1040638714550183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 11/17/2022] Open
Abstract
Two horses were referred for methemoglobinemia and hemolytic anemia following 5 acute deaths in their herd from an unidentified toxin source. Horses have a greater risk than other mammalian species of developing methemoglobinemia and hemolytic anemia following ingestion of oxidizing toxins, due to deficiencies in the mechanisms that protect against oxidative damage in erythrocytes. Their susceptibility to oxidative erythrocyte damage is evident in the numerous cases of red maple (Acer rubrum) toxicosis. The suspected toxins causing A. rubrum toxicosis are tannic acid, gallic acid, and a metabolite of gallic acid, pyrogallol. These compounds can be found in a variety of plants, posing a risk to equine health. In order to quickly identify toxin sources, 2 rapid in vitro assays were developed to screen plant extracts for the ability to induce methemoglobin formation or cause hemolysis in healthy equine donor erythrocytes. The plant extract screening focused on 3 species of the genus Pistacia: P. atlantica, P. terebinthus, and P. chinensis, which were located in the horse pasture. Extracts of the seeds and leaves of each species induced methemoglobin formation and resulted in hemolysis, with seed extracts having greater potency. The in vitro assays used in the current study provide a useful diagnostic method for the rapid identification of oxidizing agents from unidentified sources. There is no effective treatment for oxidative erythrocyte damage in horses, making rapid identification and removal of the source essential for the prevention of poisoning.
Collapse
Affiliation(s)
- Kyla M Walter
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| | - Caroline E Moore
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| | - Rana Bozorgmanesh
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| | - K Gary Magdesian
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| | - Leslie W Woods
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| | - Birgit Puschner
- Department of Molecular Biosciences (Walter, Moore, Puschner), School of Veterinary Medicine, University of California, Davis, CAVeterinary Medical Teaching Hospital (Bozorgmanesh), School of Veterinary Medicine, University of California, Davis, CADepartment of Medicine and Epidemiology (Magdesian), School of Veterinary Medicine, University of California, Davis, CACalifornia Animal Health and Food Safety Laboratory System (Puschner, Woods), School of Veterinary Medicine, University of California, Davis, CA
| |
Collapse
|
10
|
Walter KM, Zimov SA, Chanton JP, Verbyla D, Chapin FS. Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming. Nature 2006; 443:71-5. [PMID: 16957728 DOI: 10.1038/nature05040] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [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: 12/05/2005] [Accepted: 07/03/2006] [Indexed: 11/08/2022]
Abstract
Large uncertainties in the budget of atmospheric methane, an important greenhouse gas, limit the accuracy of climate change projections. Thaw lakes in North Siberia are known to emit methane, but the magnitude of these emissions remains uncertain because most methane is released through ebullition (bubbling), which is spatially and temporally variable. Here we report a new method of measuring ebullition and use it to quantify methane emissions from two thaw lakes in North Siberia. We show that ebullition accounts for 95 per cent of methane emissions from these lakes, and that methane flux from thaw lakes in our study region may be five times higher than previously estimated. Extrapolation of these fluxes indicates that thaw lakes in North Siberia emit 3.8 teragrams of methane per year, which increases present estimates of methane emissions from northern wetlands (< 6-40 teragrams per year; refs 1, 2, 4-6) by between 10 and 63 per cent. We find that thawing permafrost along lake margins accounts for most of the methane released from the lakes, and estimate that an expansion of thaw lakes between 1974 and 2000, which was concurrent with regional warming, increased methane emissions in our study region by 58 per cent. Furthermore, the Pleistocene age (35,260-42,900 years) of methane emitted from hotspots along thawing lake margins indicates that this positive feedback to climate warming has led to the release of old carbon stocks previously stored in permafrost.
Collapse
Affiliation(s)
- K M Walter
- Institute of Arctic Biology, University of Alaska Fairbanks, Alaska 99775, USA.
| | | | | | | | | |
Collapse
|
11
|
Ueki T, Toyota M, Skinner H, Walter KM, Yeo CJ, Issa JP, Hruban RH, Goggins M. Identification and characterization of differentially methylated CpG islands in pancreatic carcinoma. Cancer Res 2001; 61:8540-6. [PMID: 11731440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
To identify CpG islands differentially methylated in pancreatic adenocarcinoma, we used methylated CpG island amplification (MCA) coupled with representational difference analysis. Of 42 CpG islands identified by MCA/representational difference analysis, 7 CpG islands [methylated in carcinoma of the pancreas (MICP)] were differentially methylated in a panel of eight pancreatic cancer cell lines compared with normal pancreas. In a larger panel of 75 pancreatic adenocarcinomas, these 7 MICPs (ppENK, Cyclin G, ZBP, MICP25, 27, 36, and 38) were methylated in 93, 3, 9, 15, 48, 19, and 41% of cancers, respectively, by methylation-specific PCR but not in any of 15 normal pancreata. In pancreatic cancer cell lines, methylation of ppENK, a gene with known growth suppressive properties, was associated with transcriptional silencing that was reversible with 5-aza-2'-deoxycytidine treatment. Relationships between the methylation patterns of pancreatic adenocarcinomas and their clinicopathological features were also determined. Larger pancreatic cancers and those from older patients (P = 0.017) harbored more methylated loci than smaller tumors and those from younger patients (P = 0.017). ppENK, MICP25, and 27 were variably methylated in normal gastric, duodenal, and colonic mucosae. These data indicate that aberrant methylation of ppENK and its transcriptional repression is a common event in pancreatic carcinogenesis.
Collapse
Affiliation(s)
- T Ueki
- Department of Pathology, Johns Hopkins School of Medicine and the Johns Hopkins School of Public Health, Baltimore, Maryland 21205, USA
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Whaley DA, Attfield MD, Bedillion EJ, Walter KM, Yi Q. Regression method to estimate provisional TLV/WEEL-equivalents for non-carcinogens. Ann Occup Hyg 2000; 44:361-74. [PMID: 10930500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
There is a huge and changing number of chemicals in commerce for which workplace exposure criteria have not been assigned. Assigning an exposure criterion by an expert committee is resource-intensive-not soon available for the large majority of chemicals in current use. In the absence of assigned criteria, we have provided a regression method to estimate a first-screen estimate of a 'TLV/WEEL-equivalent' inhalation time-weighted average exposure criterion for a pure chemical (or chemical group) from a measure of a non-stochastic toxic exposure to elicit a chronic or sub-chronic health effect, known as a lowest observable adverse effect level (LOAEL) or a (highest) no observable adverse effect level (NOAEL). Results are presented for six data sets for which both a threshold limit value (TLV) or workplace environmental exposure level (WEEL) exposure criterion is presently assigned, and a LOAEL or NOAEL measure of toxic health effect was available from the United States Environmental Protection Agency Integrated Risk Information System data base. The results can be applied as a first estimate of exposure to substances for which no TLV or WEEL (TLV/WEEL) exists, and also serve as a mechanism for identifying substances for potential re-evaluation of their exposure limit, based on their relative position about the prediction models.
Collapse
Affiliation(s)
- D A Whaley
- Department of Industrial Management Systems Engineering, West Virginia University, P.O. Box 6070, Morgantown, WV 26506, USA.
| | | | | | | | | |
Collapse
|