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Ryu SH, Sohn Y, Forbes E, Jeon HS, An SJ, Kim BS, Kyung SG, Lee I. A cross-sectional study of colic and rate of return to racing in Thoroughbreds at Seoul Racecourse in Korea between 2010 and 2020. J Vet Sci 2023; 24:e81. [PMID: 38031518 PMCID: PMC10694371 DOI: 10.4142/jvs.23165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/29/2023] [Accepted: 09/26/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND The incidence of colic and the outcomes of colic surgery have not been surveyed in racetracks in Korea. OBJECTIVES This study examined the incidence, mortality, and case fatality of colic and investigated the effects of age and sex after an exploratory celiotomy on the long-term survival rate (return to racing), subsequent racing performance, and career longevity. METHODS The incidence, mortality, and case fatalities of colic were examined over an 11-year period. The records of 40 horses that had undergone a celiotomy, after participating in at least one race and 75 race-matched control horses were analyzed. The racing performance and career length of the horses that returned to racing post-surgery were compared with a control group. RESULTS The annual incidence, fatality rate of colic, and annual mortality rate at Seoul Racecourse were 6.5, 2.8 per 100 horse-years, and 0.2 deaths cases per 100 horse-years, respectively. Of the 40 horses that underwent colic surgery, 26 (65%) returned to racing. The likelihood of returning to racing decreased with increasing age of the horses, and geldings had a lower probability of returning. While the performance in the five preoperative races between the two groups was not significantly different, a significant decrease in racing performance was observed after the surgery date (p < 0.01). Horses that underwent colic surgery did not show a significant decrease in career length. CONCLUSIONS Surgical treatment for colic at the age of three and four years had a negative impact on the racing performance. On the other hand, there was no significant difference in career longevity between the two groups.
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Affiliation(s)
- Seung-Ho Ryu
- Department of Equine Resources Science, Cheju Halla University, Jeju 63092, Korea
| | - Yongwoo Sohn
- Veterinary Department, Korea Racing Authority, Gwacheon 13822, Korea
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Eliot Forbes
- Steering Committee, International Forum for the Aftercare of Racehorses, Milton 4064, Queensland, Australia
| | - Hyung Seon Jeon
- Veterinary Department, Korea Racing Authority, Gwacheon 13822, Korea
| | - Sung Jun An
- Department of Intelligent System Engineering, Cheju Halla University, Jeju 63092, Korea
| | - Byung Sun Kim
- Department of Equine Science, Cheju Halla University, Jeju 63092, Korea
| | - Soon-Goo Kyung
- Veterinary Department, Korea Racing Authority, Gwacheon 13822, Korea
| | - Inhyung Lee
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
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Yoon J, Park T, Sohn Y, Lee SK, Park BJ, Ahn HS, Go HJ, Kim DH, Lee JB, Park SY, Song CS, Lee SW, Choi IS. Surveillance of hepatitis E virus in the horse population of Korea: A serological and molecular approach. Infect Genet Evol 2022; 103:105317. [PMID: 35738550 DOI: 10.1016/j.meegid.2022.105317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Hepatitis E virus (HEV) is an emerging zoonotic pathogen causing hepatitis worldwide. Despite the prevalent evidence of interspecies HEV infection in various animal species, the role of horses in HEV epidemiology remains unclear. In this study, we investigated the prevalence of HEV infection in 283 blood and 114 fecal samples from 397 horses using sandwich enzyme-linked immunosorbent assay and nested reverse transcription-polymerase chain reaction. Among the 283 serum samples, 35 were positive for anti-HEV antibodies (12.4%; 95% confidence interval: 8.8-16.8), and four of the five sampling regions (80%) had these seropositive individuals. Analyses of the potential risk factors for HEV infection revealed that racing horses had a significantly higher risk of infection (P = 0.01). However, HEV RNA was not detected in any of the tested serum and fecal samples. To the best of our knowledge, this is the first epidemiological HEV study on horses in Republic of Korea, thereby providing evidence of HEV exposure in the horse population in Korea and specifying the risk factors for HEV infection.
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Affiliation(s)
- Jungho Yoon
- Equine Clinic, Jeju Stud Farm, Korea Racing Authority, Jeju-si, Jeju 63346, Republic of Korea; Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Taemook Park
- Equine Clinic, Jeju Stud Farm, Korea Racing Authority, Jeju-si, Jeju 63346, Republic of Korea
| | - Yongwoo Sohn
- Equine Clinic, Jeju Stud Farm, Korea Racing Authority, Jeju-si, Jeju 63346, Republic of Korea
| | - Sang-Kyu Lee
- Equine Clinic, Jeju Stud Farm, Korea Racing Authority, Jeju-si, Jeju 63346, Republic of Korea
| | - Byung-Joo Park
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hee-Seop Ahn
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Hyeon-Jeong Go
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Dong-Hwi Kim
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Joong-Bok Lee
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Seung-Yong Park
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Chang-Seon Song
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Sang-Won Lee
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - In-Soo Choi
- Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea; KU Center for Animal Blood Medical Science, Konkuk University, Gwangjin-gu, Seoul 05029, Republic of Korea.
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3
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Sohn Y, Ahn H, Ahn J. 381: Is the Halo Sign Useful in Hemorrhagic Shock? Ann Emerg Med 2008. [DOI: 10.1016/j.annemergmed.2008.06.408] [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: 10/21/2022]
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Curey TE, Goodey A, Tsao A, Lavigne J, Sohn Y, McDevitt JT, Anslyn EV, Neikirk D, Shear JB. Characterization of multicomponent monosaccharide solutions using an enzyme-based sensor array. Anal Biochem 2001; 293:178-84. [PMID: 11399030 DOI: 10.1006/abio.2001.5114] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [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
We report the development of a sensor for rapidly and simultaneously measuring multiple sugars in aqueous samples. In this strategy, enzyme-based assays are localized within an array of individually addressable sites on a micromachined silicon chip. Microspheres derivatized with monosaccharide-specific dehydrogenases are distributed to pyramidal cavities anisotropically etched in a wafer of silicon (100) and are exposed to sample solution that is forced through the cavities by a liquid chromatography pumping system. Production of fluorescent reporter molecules is monitored under stopped-flow conditions when localized dehydrogenase enzyme systems are exposed to their target sugars. We demonstrate the capability of this analysis strategy to quantify beta-D-glucose and beta-D-galactose at low micromolar to millimolar levels, with no detectable cross-talk between assay sites. Analysis is achieved either through fluorescence detection of an initial dehydrogenase product (NADH, NADPH) or by production of a secondary fluorescent product created by hydride transfer from the reduced nicotinamide cofactor to a fluorogenic reagent. The array format of this sensor provides capabilities for redundant analysis of sugars and for monitoring levels of other solution components known to affect the activity of enzymes. The use of this strategy to normalize raw fluorescence signals is demonstrated by the determination of glucose and pH on a single chip. Alternatively, uncertainties in the activity of an immobilized enzyme can be accounted for using standard additions, an approach used here in the determination of serum glucose.
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Affiliation(s)
- T E Curey
- Department of Chemistry & Biochemistry, University of Texas, Austin, Texas 78712, USA
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Goodey A, Lavigne JJ, Savoy SM, Rodriguez MD, Curey T, Tsao A, Simmons G, Wright J, Yoo SJ, Sohn Y, Anslyn EV, Shear JB, Neikirk DP, McDevitt JT. Development of multianalyte sensor arrays composed of chemically derivatized polymeric microspheres localized in micromachined cavities. J Am Chem Soc 2001; 123:2559-70. [PMID: 11456925 DOI: 10.1021/ja003341l] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of a chip-based sensor array composed of individually addressable polystyrene-poly(ethylene glycol) and agarose microspheres has been demonstrated. The microspheres are selectively arranged in micromachined cavities localized on silicon wafers. These cavities are created with an anisotropic etch and serve as miniaturized reaction vessels and analysis chambers. A single drop of fluid provides sufficient analysis media to complete approximately 100 assays in these microetch pits. The cavities possess pyramidal pit shapes with trans-wafer openings that allows for both fluid flow through the microreactors/analysis chambers and optical access to the chemically sensitive microspheres. Identification and quantitation of analytes occurs via colorimetric and fluorescence changes to receptor and indicator molecules that are covalently attached to termination sites on the polymeric microspheres. Spectral data are extracted from the array efficiently using a charge-coupled device allowing for the near-real-time digital analysis of complex fluids. The power and utility of this new microbead array detection methodology is demonstrated here for the analysis of complex fluids containing a variety of important classes of analytes including acids, bases, metal cations, metabolic cofactors, and antibody reagents.
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Affiliation(s)
- A Goodey
- Department of Chemistry & Biochemistry, Institute for Cellular & Molecular Biology, Center for Nanostructured Materials, The University of Texas at Austin, Austin, TX 78712, USA
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Yim H, Sohn Y. Numerical simulation and visualization of elastic waves using mass-spring lattice model. IEEE Trans Ultrason Ferroelectr Freq Control 2000; 47:549-558. [PMID: 18238581 DOI: 10.1109/58.842041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A computer program package has been developed for simulation and visualization of two-dimensional elastic wave propagation and scattering using the mass-spring lattice model (MSLM) and, for comparison, a finite difference model. To assess the reliability of the numerical schemes, their convergence and accuracy have been analysed using the Taylor series expansion and the von Neumann analysis methods. As a result, the grid spacing-time increment combinations previously adopted in the literature have proved to be non-optimal. The optimal combinations have been found and shown to yield the most accurate results with the least computation time, particularly in the high frequency regime. Using these algorithms, a program package has been developed in Visual C++ (Microsoft, Redmond, WA) with graphic user interfaces for convenient exploration of visualized results. Numerical results have been obtained for some fundamental problems in ultrasonic testing such as plane waves incident on cracks. All numerical results have shown excellent qualitative agreements with the analytical results of the wave physics, as the reflected, diffracted, head, and Rayleigh waves have been observed. Also, for numerical results with anisotropic media, the cusps on the shear wavefronts have been observed. Finally, slight modification of the modeling method for free surfaces has led to more accurate prediction of Rayleigh waves.
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Affiliation(s)
- H Yim
- Department of Mechanical Engineering, Hong-Ik University, Seoul 121-791, Korea.
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Chun KS, Sohn Y, Kim HS, Kim OH, Park KK, Lee JM, Moon A, Lee SS, Surh YJ. Anti-tumor promoting potential of naturally occurring diarylheptanoids structurally related to curcumin. Mutat Res 1999; 428:49-57. [PMID: 10517978 DOI: 10.1016/s1383-5742(99)00031-9] [Citation(s) in RCA: 48] [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] [Indexed: 01/14/2023]
Abstract
In recent years, there have been considerable efforts to search for naturally occurring substances for intervention of carcinogenesis. Many components from medicinal or dietary plants have been identified to possess potential chemopreventive properties. For instance, curcumin, a yellow colouring agent from turmeric (Curcuma longa Linn., Zingiberaceae) has been shown to inhibit tumor formation in diverse animal models. Alpinia oxyphylla Miquel that also belongs to ginger family has been used in oriental herbal medicine. In the present work, we have evaluated the anti-tumor promoting potential of yakuchinone A (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenyl-3-heptanone) and yakuchinone B (1-[4'-hydroxy-3'-methoxyphenyl]-7-phenylhept-1-en-3-one), major pungent ingredients of A. oxyphylla. Thus, topical application of yakuchinone A or B significantly suppressed TPA-induced epidermal ornithine decarboxylase activity. They also reduced TPA-stimulated production of tumor necrosis factor-alpha in cultured human promyelocytic leukemia (HL-60) cells. Both compounds blunted the TPA-induced superoxide generation in differentiated HL-60 cells in a concentration-related manner and also inhibited lipid peroxidation in rat brain homogenates. Furthermore, yakuchinone A and yakuchinone B nullified the activation of the activator protein-1 (AP-1) in immortalized mouse fibroblast cells in culture. These findings indicate that pungent diarylheptanoids from A. oxyphylla have anti-tumor promotional properties that can contribute to their chemopreventive potential.
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Affiliation(s)
- K S Chun
- College of Pharmacy, Seoul National University, Shinlim-dong, Kwanak-gu, Seoul, South Korea
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Surh YJ, Kim SG, Park KK, Sohn Y, Lee JM, Kim ND, Miller JA. Chemopreventive effects of 2-(allylthio)pyrazine on hepatic lesion, mutagenesis and tumorigenesis induced by vinyl carbamate or vinyl carbamate epoxide. Carcinogenesis 1998; 19:1263-7. [PMID: 9683187 DOI: 10.1093/carcin/19.7.1263] [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: 11/14/2022] Open
Abstract
2-(Allylthio)pyrazine (2-AP), synthesized for its possible use as a hepatoprotective agent, has been found to selectively inhibit rat hepatic cytochrome P450 2E1 (Kim et al., Biochem. Pharmacol., 53, 261-269, 1997), while it enhances the activities of phase II detoxification enzymes such as glutathione S-transferase and epoxide hydrolase. As part of a program in evaluating the chemopreventive potential of 2-AP, we have determined its effects on hepatotoxicity, mutagenicity and tumorigenicity of vinyl carbamate (VC), a prototypic hepatocarcinogen preferentially activated by P450 2E1 to the ultimate carcinogenic metabolite vinyl carbamate epoxide (VCO), which undergoes detoxification by glutathione conjugation and oxirane hydrolysis. Administration of 2-AP (100 mg/kg body wt) to male Sprague-Dawley rats by gavage, 2 days, 1 day and 4 h prior to VC or VCO, markedly ameliorated the hepatotoxicity of these compounds as determined by decreased serum aspartate aminotransferase and alanine aminotransferase activities. Furthermore, 2-AP pre-treatment significantly suppressed the VC-induced hepatocarcinogenesis in infant male B6C3F1 mice. In a separate experiment, the multiplicities of skin tumors formed in female ICR mice treated with 5.8 micromol of VC or VCO were inhibited 58 and 70%, respectively, by pre-treatment with 2-AP by oral administration. The mutational spectrum of ras-oncogene in papillomas was not altered by 2-AP pre-treatment. 2-AP also inhibited the mutagenicity of VC in the Salmonella-microsome assay. Taken together, these findings suggest that 2-AP is a potential chemopreventive agent.
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Affiliation(s)
- Y J Surh
- Seoul National University College of Pharmacy, South Korea.
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Kim SG, Surh YJ, Sohn Y, Yoo JK, Lee JW, Liem A, Miller JA. Inhibition of vinyl carbamate-induced hepatotoxicity, mutagenicity, and tumorigenicity by isopropyl-2-(1,3-dithietane-2-ylidene)-2-[N-(4-methylthiazol-2- yl)carbamoyl]acetate (YH439). Carcinogenesis 1998; 19:687-90. [PMID: 9600356 DOI: 10.1093/carcin/19.4.687] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Isopropyl-2-(1,3-dithietane-2-ylidene)-2-[N-(4-methylthiazol -2-yl)carbamoyl]acetate (YH439) is a novel dithioylidene malonate derivative developed for the treatment of hepatic injury. The compound has been found to down-regulate the expression of hepatic cytochrome P-450 2E1 (CYP2E1) at the transcriptional level (8). Certain organosulfur compounds present in garlic elicit protective effects on chemically induced carcinogenesis and mutagenesis and their chemopreventive activities are associated in part with inhibition of CYP2E1. As part of a program to determine the likely chemopreventive potential of YH439, we initially examined its effects on hepatotoxicity induced by vinyl carbamate (VC), a proximate carcinogen that is preferentially bioactivated by CYP2E1. A single i.p. injection of VC (125 mg/kg body wt) to male Sprague-Dawley rats resulted in severe hepatic lesions as demonstrated by elevated levels of serum enzymes such as alanine aminotransferase and aspartate aminotransferase. Histopathological evaluation of liver sections from VC-treated animals revealed that the hepatic damage mainly consisted of centrilobular necrosis with sinusoidal congestion. Oral administration of YH439 (200 mg/kg body wt) to male Sprague-Dawley rats 2 days, 1 day and 4 h prior to VC completely prevented the hepatic damage caused by this carcinogen. In another experiment, rat hepatic microsome-mediated bacterial mutagenicity of VC was suppressed by YH439 in a dose-related manner. Furthermore, pretreatment of female CD-1 mice with YH439 by gastric intubation resulted in diminution of VC-induced skin carcinogenesis.
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Affiliation(s)
- S G Kim
- McArdle Laboratory for Cancer Research, University of Wisconsin Medical School, Madison 53706, USA
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Nakamura M, Tatsumi E, Masuzawa T, Taenaka Y, Nakatani T, Sohn Y, Endo S, Ohno T, Takiura K, Nishimura T, Takewa Y, Wakisaka Y, Takano H. Early changes in circulating blood volume and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart. ASAIO J 1997; 43:M663-8. [PMID: 9360129] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The early changes in circulating blood volume (CBV) and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart (EH-TAH) were investigated in a calf and compared with results in a sham operated control calf. CBV was measured by the dye dilution method using indocyanine green. CBV and humoral factors were periodically investigated. In the EH-TAH implanted calf, the cardiac output was estimated at 6-7 L/ min (94-109 ml/kg/min), and the aortic pressure and aerobic metabolic condition were favorable. Nevertheless, the CBV was increased to 132 and 168% of the pre-operative value (range in the control calf, 83-103%) on post operative days 4 and 8, respectively. The atrial natriuretic peptide level on days 2, 5, and 7 was 23, 170, and 240 (in the control calf, 19-61) pg/ml, respectively, and the antidiuretic hormone level was 7.3, 2.0, and 1.3 (0.5-1.3) pg/ ml, respectively. The plasma renin activity was 3.2, 3.7, and 3.1 (0.5-0.3) ng/ml/hr, respectively. The angiotensin-I and angiotensin-II levels were also increased in the EH-TAH implanted calf. It is concluded that significant water retention occurs even at sufficient cardiac output early after EH-TAH implantation. The changes in humoral factors are suggested to arise secondary to the increased CBV or other unknown factors.
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Affiliation(s)
- M Nakamura
- Department of Artificial Organs, National Cardiovascular Center Research Institute, Osaka, Japan
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Park KK, Sohn Y, Liem A, Kim HJ, Stewart BC, Miller JA. The electrophilic, mutagenic and tumorigenic activities of phenyl and 4-nitrophenyl vinyl ethers and their epoxide metabolites. Carcinogenesis 1997; 18:431-7. [PMID: 9054639 DOI: 10.1093/carcin/18.2.431] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The metabolism and mutagenicity of phenyl and 4-nitrophenyl vinyl ethers (PVE and NPVE) and their epoxide metabolites, phenoxyoxirane (PO) and 2'-(4-nitro-phenoxy)oxirane (NPO), were studied including reactions with DNA and tests for carcinogenicity. PVE and NPVE were epoxidized in dry acetone by dimethyldioxirane to give high yields (95%) of the pure epoxides. The epoxides are unstable in aqueous media and in 0.1 N phosphate buffer, pH 7.4, at 37 degrees C; they had half-lives of 2.7 min (PO) and 4.4 min (NPO). These times were reduced to 1.9 min (PO) and 2.5 min (NPO) in the presence of isotonic (154 mM) chloride ion. In neutral phosphate buffer these epoxides hydrolyze to form glycolaldehyde and the corresponding phenols; in the presence of chloride ion, chloroacetaldehyde and several unknown compounds are also formed. Glycolaldehyde was also found as a hydrolysis product of the presumed epoxides generated in the hepatic microsomal oxidation of PVE and NPVE. PO and NPO reacted with DNA to form adducts that depurinated in weak acid to form 7-(2'-oxoethyl)guanine and N(2),3-ethenoguanine. PO was weakly mutagenic in Salmonella typhimurium TA1535 while NPO was much more mutagenic under the same conditions. PO and NPO were found to have mutagenic half-lives that matched their chemical half-lives. PO and NPO were found to be tumorigenic in the skin of mice after single or five initiating doses followed by multiple doses of phorbol ester (TPA). NPO was a stronger tumor initiator than PO. NPO had appreciable activity as an initiator of hepatoma formation in infant male B6C3F1 mice. Thus PO and NPO are electrophilic, mutagenic and tumorigenic metabolites of their corresponding phenyl vinyl ethers.
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Affiliation(s)
- K K Park
- McArdle Laboratory for Cancer Research, University of Wisconsin Medical School, Madison 53706, USA
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