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David J Smith - One of the best experts on this subject based on the ideXlab platform.
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Effects of Ractopamine HCl on Escherichia coli O157:H7 and Salmonella In Vitro and on Intestinal Populations and Fecal Shedding in Experimentally Infected Sheep and Pigs
Current Microbiology, 2006Co-Authors: T. S. Edrington, David J Smith, T. R. Callaway, K. J. Genovese, R. C. Anderson, D. J. NisbetAbstract:The effects of the β-agonist Ractopamine, approved for use in finishing swine and cattle to improve carcass quality and performance, were examined on two important foodborne pathogens, Escherichia coli O157:H7 and Salmonella . Ractopamine, administered to sheep before and after oral inoculation with E. coli O157:H7, increased ( P < 0.01) fecal shedding and tended to increase ( P = 0.08) cecal populations of the challenge strain. Pigs receiving Ractopamine in the diet and then experimentally infected with Salmonella Typhimurium, had decreased ( P < 0.05) fecal shedding and fewer ( P = 0.05) liver samples positive for the challenge strain of Salmonella . Pure cultures of E. coli O157:H7 (used in the present sheep study), E. coli O157:H19 (isolated from pigs with postweaning diarrhea), Salmonella Typhimurium (used in the present pig study), and Salmonella Choleraesuis were incubated with varying concentrations of Ractopamine to determine if Ractopamine has a direct effect on bacterial growth. No differences in growth rate were observed for either strain of E. coli or for Salmonella Typhimurium when incubated with increasing concentrations of Ractopamine. The growth rate for Salmonella Choleraesuis was increased with the addition of 2.0 μg Ractopamine/ml compared with the other concentrations examined. Collectively, these results indicate that Ractopamine may influence gut populations and fecal shedding of E. coli O157:H7 and Salmonella . Because Ractopamine is currently approved to be fed to finishing cattle and swine immediately before slaughter, any potential for decreasing foodborne pathogens has exciting food safety implications.
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determination of Ractopamine in cattle and sheep urine samples using an optical biosensor analysis comparative study with hplc and elisa
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Weilin L Shelver, David J SmithAbstract:A biosensor method, using the surface plasmon resonance (SPR) principle, was developed for the determination of Ractopamine in cattle and sheep urine. A monoclonal antibody was used to compete with Ractopamine in the sample and Ractopamine immobilized on the sensor chip. Addition of bovine serum albumin (BSA, 1 mg/mL) as an antibody stabilizer to the incubation buffer was required to achieve a stable biosensor response throughout each sample set. The calibration curve gave a mean IC(50) of 4.7 +/- 0.21 ng/mL (n = 7). Over sample concentrations from 2.5 to 10 ng/mL recoveries were typically approximately 100-110%, whereas inter- and intra-assay reproducibilities (% CV) were usually less than 10 and 6%, respectively. Comparison of biosensor results with results obtained from high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assays (ELISA) using enzyme-hydrolyzed urine (to convert Ractopamine conjugates to free Ractopamine) gave correlation coefficients of 0.94 for sheep and 0.86 for cattle. Slopes of the lines, with zero intercepts, equaled 0.80 for sheep and 0.74 for cattle. For untreated (nonhydrolyzed) urine samples, the correlations between biosensor and HPLC results were 0.95 for sheep and 0.72 for cattle with slopes of 1.18 (sheep) and 1.69 (cattle). The slopes greater than unity indicate that the biosensor responded to Ractopamine metabolites in addition to free Ractopamine. The biosensor assay is an excellent analytical tool to screen Ractopamine residues in sheep or cattle urine, and the results should be extendible to other species with suitable validation.
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liquid chromatography electrospray tandem mass spectrometric analysis of incurred Ractopamine residues in livestock tissues
Rapid Communications in Mass Spectrometry, 2002Co-Authors: Mona I Churchwell, David J Smith, Lee C Holder, David Little, Steve W Preece, Daniel R DoergeAbstract:Ractopamine HCl is a beta-adrenergic agonist (beta-agonist) recently approved by the U.S. Food and Drug Administration, but not other governmental agencies, for use in finishing swine. For these reasons, it was important to develop and validate mass spectrometric methods for the detection and confirmation of Ractopamine residues in livestock marker tissues. Incurred tissues in cattle, sheep, turkeys, and ducks were generated during 7-day Ractopamine feeding (20 ppm in diets) periods. Disposition of Ractopamine residues in liver and pigmented retinal epithelium was determined in animals slaughtered with withdrawal periods of 0, 3, and 7 days. Ractopamine residues, purified using solid-phase extraction, were measured using liquid chromatography (LC) and electrospray with detection by tandem mass spectrometry (MS/MS) in the multiple reaction-monitoring (MRM) mode. Total Ractopamine residues (parent Ractopamine + hydrolyzed conjugates) in liver were detected in all species on withdrawal day 0 (2-97 ppb) and were greatly diminished in all species by withdrawal day 7 (<1 ppb). Bovine and ovine retina had lower levels of Ractopamine (0.5-3 ppb) than liver, and occular residues increased with withdrawal time, suggesting redistribution into this tissue. Lower limits of quantification were found to be approximately 0.1 ppb in liver and retina. Incurred Ractopamine residues were confirmed by the precise and accurate agreement of MRM intensity ratios of diagnostic fragment ions (m/z 284, 164, and 121) from the protonated molecule between Ractopamine residues in incurred samples and an authentic Ractopamine standard. The limits of confirmation in liver and retina using recognized acceptance criteria were below 1 ppb. The high sensitivity and specificity for measurement and confirmation of Ractopamine residues suggests this method will be applicable for regulatory residue surveillance programs.
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Liquid chromatography/electrospray tandem mass spectrometric analysis of incurred Ractopamine residues in livestock tissues
Rapid communications in mass spectrometry : RCM, 2002Co-Authors: Mona I Churchwell, David J Smith, David Little, Steve W Preece, C. Lee Holder, Daniel R DoergeAbstract:Ractopamine HCl is a beta-adrenergic agonist (beta-agonist) recently approved by the U.S. Food and Drug Administration, but not other governmental agencies, for use in finishing swine. For these reasons, it was important to develop and validate mass spectrometric methods for the detection and confirmation of Ractopamine residues in livestock marker tissues. Incurred tissues in cattle, sheep, turkeys, and ducks were generated during 7-day Ractopamine feeding (20 ppm in diets) periods. Disposition of Ractopamine residues in liver and pigmented retinal epithelium was determined in animals slaughtered with withdrawal periods of 0, 3, and 7 days. Ractopamine residues, purified using solid-phase extraction, were measured using liquid chromatography (LC) and electrospray with detection by tandem mass spectrometry (MS/MS) in the multiple reaction-monitoring (MRM) mode. Total Ractopamine residues (parent Ractopamine + hydrolyzed conjugates) in liver were detected in all species on withdrawal day 0 (2-97 ppb) and were greatly diminished in all species by withdrawal day 7 (
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Tissue residues of Ractopamine and urinary excretion of Ractopamine and metabolites in animals treated for 7 days with dietary Ractopamine.
Journal of animal science, 2002Co-Authors: David J Smith, W. L. ShelverAbstract:Ractopamine HCl is a beta-adrenergic leanness-enhancing agent recently approved for use in swine. Depletion of Ractopamine in tissues, and elimination of Ractopamine and its metabolites in urine, is of interest for the detection of off-label use. The objectives of this study were to measure the residues of Ractopamine in livers and kidneys of cattle (n = 6), sheep (n = 6), and ducks (n = 9) after treatment with dietary Ractopamine for seven (sheep, ducks) or eight (cattle) consecutive days and to measure the depletion of Ractopamine from urine of cattle and sheep. Two cattle and sheep and three ducks were each slaughtered with withdrawal periods of 0, 3, and 7 d. Urine samples were collected daily from cattle and sheep. Tissue Ractopamine concentrations were determined using the regulatory method (FDA approved) for Ractopamine in swine tissues. Ractopamine residues in urine samples were measured before and after hydrolysis of conjugates. Analysis was performed with HPLC using fluorescence detection after liquid- (hydrolyzed samples) and(or) solid-phase extraction. No residues were detected in duck tissues. Liver residues in sheep averaged 24.0 and 2.6 ppb after 0- and 3-d withdrawal periods, respectively. Sheep liver residues after a 7-d withdrawal period were less than the limit of quantification (2.5 ppb). Sheep kidney residues were 65.1 and undetectable at 0- and at 3- and 7-d, withdrawal periods, respectively. Cattle liver residues were 9.3, 2.5, and undetectable after 0-, 3-, and 7-d withdrawal periods, respectively; kidney residues were 97.5, 3.4, and undetectable at the same respective withdrawal periods. Concentrations of parent Ractopamine in sheep urine were 9.8+/-3.3 ppb on withdrawal d 0 and were below the LOQ (5 ppb) beyond the 2-d withdrawal period. After the hydrolysis of conjugates, Ractopamine concentrations were 5,272+/-1,361 ppb on withdrawal d 0 and 178+/-78 ppb on withdrawal d 7. Ractopamine concentrations in cattle urine ranged from 164+/-61.7 ng/mL (withdrawal d 0) to below the LOQ (50 ppb) on withdrawal d 4. After the hydrolysis of conjugates in cattle urine, Ractopamine concentrations were 4,129+/-2,351 ppb (withdrawal d 0) to below the LOQ (withdrawal d 6). These data indicate that after the hydrolysis of conjugates, Ractopamine should be detectable in urine of sheep as long as 7 d after the last exposure to Ractopamine and as long as 5 d after withdrawal in cattle.
Jianzhong Shen - One of the best experts on this subject based on the ideXlab platform.
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validation of an ultra performance liquid chromatography tandem mass spectrometry method for determination of Ractopamine application to residue depletion study in swine
Food Chemistry, 2011Co-Authors: Yichun Dong, Xi Xia, Xia Wang, Shuangyang Ding, Suxia Zhang, Haiyang Jiang, Jinfeng Liu, Zhongze Feng, Mingxia Zhou, Jianzhong ShenAbstract:Abstract A sensitive and reliable method was developed and validated for the analysis of Ractopamine in swine tissues. The sample preparation procedure was based on hydrolysis overnight, extraction with ethyl acetate, and solid-phase extraction cleanup. The target compound was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry. The average recoveries ranged between 93.3% and 106.5%, with relative standard deviations of 7.2–12.8%. The detection and quantification limits were 0.2 and 0.5 μg/kg, respectively. The depletion profile of Ractopamine was studied in healthy pigs after oral administration of feed containing 20 mg/kg Ractopamine for 30 consecutive days. Ractopamine residues were still detected 11 days post-medication in all tissues examined with the exception of muscle. The highest Ractopamine level was found in lung tissue. The developed method has been successfully applied to the depletion study of Ractopamine in swine tissues.
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Residue depletion of Ractopamine and its metabolites in swine tissues, urine, and serum.
Journal of agricultural and food chemistry, 2007Co-Authors: Zhiyi Qiang, Fenqin Shentu, Bing Wang, Jianping Wang, Jianyu Chang, Jianzhong ShenAbstract:Ractopamine hydrochloride is a beta-adrenergic leanness-enhancing agent approved for use in swine in the United States. Depletion of Ractopamine and its metabolites from animal tissues, urine, and serum is of interest for the detection of illegal use. The objectives of this study were to measure the residues of Ractopamine in swine incurred samples after treatment with dietary Ractopamine for 28 consecutive days. An efficient and sensitive analytical method was developed for the detection of parent Ractopamine and its metabolites in swine tissues, urine, and serum by HPLC-FLD. After extraction, enzymatic digestion, and solid-phase cleanup of the samples, Ractopamine residues were determined by liquid chromatography (LC) with fluorescence detector. The limits of detection (LOD) for tissues, urine, and serum were 1 ng g(-1), 0.5 ng mL(-1), and 0.5 ng mL(-1), respectively. Recoveries ranged from 70.5 to 94.5% for samples fortified at 1-50 ng g(-1) or ng mL(-1). Sixty pigs were fed twice daily for 28 consecutive days with feeds containing 18 mg kg(-1) Ractopamine HCl. The residue concentrations in urine, liver, and kidney were 650.06 ng mL(-1), 46.09 ng g(-1), and 169.27 ng g(-1), respectively, compared with those in muscle, fat, and serum (4.94 ng g(-1), 3.28 ng g(-1), and 7.48 ng mL(-1), respectively) at the feeding period of 7 days. The residue concentrations at withdrawal period of 0 days in all edible tissues were lower than tolerance values established by the FDA and MRL values listed by the JECFA. These data support the withdrawal time of 0 days established by the FDA for Ractopamine used as feed additive in swine.
Daniel R Doerge - One of the best experts on this subject based on the ideXlab platform.
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liquid chromatography electrospray tandem mass spectrometric analysis of incurred Ractopamine residues in livestock tissues
Rapid Communications in Mass Spectrometry, 2002Co-Authors: Mona I Churchwell, David J Smith, Lee C Holder, David Little, Steve W Preece, Daniel R DoergeAbstract:Ractopamine HCl is a beta-adrenergic agonist (beta-agonist) recently approved by the U.S. Food and Drug Administration, but not other governmental agencies, for use in finishing swine. For these reasons, it was important to develop and validate mass spectrometric methods for the detection and confirmation of Ractopamine residues in livestock marker tissues. Incurred tissues in cattle, sheep, turkeys, and ducks were generated during 7-day Ractopamine feeding (20 ppm in diets) periods. Disposition of Ractopamine residues in liver and pigmented retinal epithelium was determined in animals slaughtered with withdrawal periods of 0, 3, and 7 days. Ractopamine residues, purified using solid-phase extraction, were measured using liquid chromatography (LC) and electrospray with detection by tandem mass spectrometry (MS/MS) in the multiple reaction-monitoring (MRM) mode. Total Ractopamine residues (parent Ractopamine + hydrolyzed conjugates) in liver were detected in all species on withdrawal day 0 (2-97 ppb) and were greatly diminished in all species by withdrawal day 7 (<1 ppb). Bovine and ovine retina had lower levels of Ractopamine (0.5-3 ppb) than liver, and occular residues increased with withdrawal time, suggesting redistribution into this tissue. Lower limits of quantification were found to be approximately 0.1 ppb in liver and retina. Incurred Ractopamine residues were confirmed by the precise and accurate agreement of MRM intensity ratios of diagnostic fragment ions (m/z 284, 164, and 121) from the protonated molecule between Ractopamine residues in incurred samples and an authentic Ractopamine standard. The limits of confirmation in liver and retina using recognized acceptance criteria were below 1 ppb. The high sensitivity and specificity for measurement and confirmation of Ractopamine residues suggests this method will be applicable for regulatory residue surveillance programs.
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Liquid chromatography/electrospray tandem mass spectrometric analysis of incurred Ractopamine residues in livestock tissues
Rapid communications in mass spectrometry : RCM, 2002Co-Authors: Mona I Churchwell, David J Smith, David Little, Steve W Preece, C. Lee Holder, Daniel R DoergeAbstract:Ractopamine HCl is a beta-adrenergic agonist (beta-agonist) recently approved by the U.S. Food and Drug Administration, but not other governmental agencies, for use in finishing swine. For these reasons, it was important to develop and validate mass spectrometric methods for the detection and confirmation of Ractopamine residues in livestock marker tissues. Incurred tissues in cattle, sheep, turkeys, and ducks were generated during 7-day Ractopamine feeding (20 ppm in diets) periods. Disposition of Ractopamine residues in liver and pigmented retinal epithelium was determined in animals slaughtered with withdrawal periods of 0, 3, and 7 days. Ractopamine residues, purified using solid-phase extraction, were measured using liquid chromatography (LC) and electrospray with detection by tandem mass spectrometry (MS/MS) in the multiple reaction-monitoring (MRM) mode. Total Ractopamine residues (parent Ractopamine + hydrolyzed conjugates) in liver were detected in all species on withdrawal day 0 (2-97 ppb) and were greatly diminished in all species by withdrawal day 7 (
Keqiang Lai - One of the best experts on this subject based on the ideXlab platform.
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Rapid determination of Ractopamine in swine urine using surface-enhanced Raman spectroscopy.
Journal of agricultural and food chemistry, 2011Co-Authors: Fuli Zhai, Yiqun Huang, Xichang Wang, Keqiang LaiAbstract:Ractopamine is approved for use in swine to improve carcass leanness in the United States, but banned in the European Union and China because Ractopamine residue may pose health risks. This study investigated the possibility of applying surface-enhanced Raman spectroscopy (SERS) for analysis of Ractopamine in swine urine. Ractopamine (0.1–10 μg mL–1) was added to urine samples collected from 20 swine to prepare a total of 240 samples. A simple centrifugation, a liquid–liquid extraction (LLE) method, and a more complicated method involving liquid–liquid extraction and solid-phase extraction (LLE-SPE) were used to extract Ractopamine from urine samples. Principal component analysis (PCA) and partial least-squares (PLS) regression were used for spectral data analyses. Although no satisfactory result was obtained with the centrifugation method, Ractopamine could be detected at levels of 0.8 and 0.4 μg mL–1 with the LLE and LLE-SPE extraction methods, respectively. The R2 of the PLS model of actual Ractopamine...
Dustin Dee Boler - One of the best experts on this subject based on the ideXlab platform.
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Ractopamine-induced changes in the proteome of post-mortem beef longissimus lumborum muscle
South African Journal of Animal Science, 2019Co-Authors: H. M. Kim, M.n. Nair, Surendranath P. Suman, C.m. Beach, C. Zhai, B. M. Edenburn, Tara L. Felix, Anna Carol Dilger, Dustin Dee BolerAbstract:Ractopamine is a beta-adrenergic agonist that is approved for use in beef cattle, pigs and turkeys as a repartitioning agent to increase lean muscle deposition and decrease lipogenesis. Although the effects of dietary Ractopamine on the proteome profile of post-mortem pork muscles have been examined, its influence on beef muscle proteome has not been studied. Therefore, the objective of this study was to examine the effect of Ractopamine on the proteome profile of post-mortem beef longissimus lumborum (LL) muscle. LL muscle samples were obtained from the carcasses of six (n = 6) steers fed Ractopamine (RAC; 400 mg Ractopamine hydrochloride for 28 days) and six (n = 6) steers fed no Ractopamine (CON). The muscle proteome was analysed using two-dimensional gel electrophoresis and tandem mass spectrometry. Five differentially abundant spots were identified, and all the spots were over-abundant in RAC. The identified proteins were involved in muscle structure development (F-actin-capping protein subunit beta-2; PDZ and LIM domain protein-3), chaperone activity (heat shock protein beta-1), oxygen transport (myoglobin), and glycolysis (L-lactate dehydrogenase A chain). These results suggested that dietary Ractopamine could influence the abundance of enzymes associated with muscle development and muscle fibre type shift in beef LL muscle. Keywords: growth promotants, meat quality, proteomics
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Ractopamine-induced changes in sarcoplasmic proteome profile of post-rigor pork semimembranosus muscle
South African Journal of Animal Science, 2017Co-Authors: M.n. Nair, Surendranath P. Suman, X. Luo, C.m. Beach, Benjamin M. Bohrer, Dustin Dee BolerAbstract:Ractopamine is a beta-adrenergic agonist that increases leanness and carcass weight in finishing pigs. Our previous study observed that dietary Ractopamine increased the abundance of several glycolytic enzymes in the sarcoplasmic proteome of post-rigor pork longissimus thoracis muscle. Pork semimembranosus is an economically important muscle and demonstrates differences in biochemistry compared with longissimus thoracis. Nonetheless, the effects of Ractopamine on sarcoplasmic proteome of semimembranosus have not been evaluated yet. Therefore, this study examined the influence of Ractopamine on sarcoplasmic proteome of post-rigor pork semimembranosus. Analyses of sarcoplasmic proteome of semimembranosus muscles from control (CON; diet without Ractopamine) and Ractopamine-fed (RAC; 7.4 mg/kg for 14 days followed by 10.0 mg/kg for 14 days) barrows revealed that haemoglobin subunit beta, alpha-crystallin B, and titin fragments were over-abundant in CON. In contrast, myosin light chain 1/3 and tripartite motif-containing protein 72 were over-abundant in RAC. The low abundance of haemoglobin subunit beta and alpha crystallin B in RAC could be attributed to fibre type shift (from oxidative to glycolytic) in response to Ractopamine. The over-abundance of MLC 1/3 and tripartite motif-containing protein 72 in RAC could be due to the increased myofibrillar protein synthesis and muscle mass in Ractopamine-fed pigs. Dietary Ractopamine decreased the abundance of sarcoplasmic proteins involved in oxygen transport and chaperone activity, but increased the abundance of proteins involved in muscle contraction and plasma membrane repair in pork semimembranosus muscle. Keywords : Pork, Ractopamine, sarcoplasmic proteome, semimembranosus
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Dietary Ractopamine influences sarcoplasmic proteome profile of pork Longissimus thoracis
Meat science, 2014Co-Authors: Bruno R C Costa-lima, Surendranath P. Suman, C.m. Beach, Benjamin M. Bohrer, Teófilo José Pimentel Da Silva, Expedito Tadeu Facco Silveira, Dustin Dee BolerAbstract:Dietary Ractopamine improves pork leanness, whereas its effect on sarcoplasmic proteome has not been characterized. Therefore, the influence of Ractopamine on sarcoplasmic proteome of post-mortem pork Longissimus thoracis muscle was examined. Longissimus thoracis samples were collected from carcasses (24 h post-mortem) of purebred Berkshire barrows (n=9) managed in mixed-sex pens and fed finishing diets containing Ractopamine (RAC; 7.4 mg/kg for 14 days followed by 10.0 mg/kg for 14 days) or without Ractopamine for 28 days (CON). Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis and mass spectrometry. Nine protein spots were differentially abundant between RAC and CON groups. Glyceraldehyde-3-phosphate dehydrogenase and phosphoglucomutase-1 were over-abundant in CON, whereas serum albumin, carbonic anhydrase 3, L-lactate dehydrogenase A chain, fructose-bisphosphate aldolase A, and myosin light chain 1/3 were over-abundant in RAC. These results suggest that Ractopamine influences the abundance of enzymes involved in glycolytic metabolism, and the differential abundance of glycolytic enzymes could potentially influence the conversion of muscle to meat.
