• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.285-289
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• 2011

This study was conducted to determine the content of non-steroidal anti-inflammatory drugs (NSAIDs) in meats available on the Korean markets. The analysis was carried out using following conditions; C18 column ($100{\times}2.1$ mm, 1.7 ${\mu}m$), mobile phase composed of DW (containing 0.1% formic acid): acetonitrile (containing 0.1% formic acid), binary pump at a flow rate of 0.3 ml/min and 5 ${\mu}l$ of injection volume, MS/MS detector with ESI positive mode. The calibration range of five NSAIDs showed linearity ($r^2{\geq}0.99$) at concentration range of 3.125~200 ${\mu}g$/kg. The recoveries in fortified muscle more than 78.7~100.3%. The detection limits for meloxicam, ketoprofen, flunixin, carprofen and tolfenamic acid were 3.5, 1.6, 1.7, 9.8 and 4.8 ${\mu}g$/kg, respectively. We also monitored NSAIDs residue in cattle muscle 51 samples. The test results, NSAIDs were all not founded.

• Korean Journal of Poultry Science
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• v.33 no.4
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• pp.283-293
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• 2006

Two experiments were conducted to investigate the effects of dietary activated charcoal mixed with wood vinegar (AC) on broiler performance and antibiotics residue in eggs. In experiment 1, a total of low hundred fifty, 1-day-old male broile. chicks (Ross) were divided into 6 groups, consisting 3 replicates of 25 birds each, and 134 one of the six experimental diets: devoid of AC and antibiotics (negative control), devoid of AC with 0.1% antibiotics (positive control), devoid of antibiotics with 1% AC, with 0.1% antibiotics and 1% AC, devoid of antibiotics with 2% AC, with 0.1% antibiotics and 2% AC, for 5 wks. Feed consumption and body weights were measured weekly. At the end of the experiment, eight birds from each group were selected and sacrificed. The relative weight of organs and characteristics of breast muscle were investigated. There were no significant differences in feed intake, body weight gain and feed conversion rate among the treatments. There were also no significant differences in the relative weight of breast meat, leg and liver. The abdominal fat tended to be decreased by the dietary AC. Significant differences were shown (P<0.05) in meat redness (a) and yellowness (b) among the treatments. However, the sensual characteristics of breast muscle was not affected by the dietary treatments. There were significant differences in total microbes, Coli forms and lactic acid bacteria (P<0.05) among the treatments. In experiment 2, a total of ninety, 40-wk-old Hy-line Brown laying hens were divided into 3 groups, consisting 3 replicates of 10 birds each and fed medicated control diet devoid of AC or diets containing 1% AC and 2% AC for 2 wks. The residue of antibiotics in Plasma and egg Yolk were significantly decreased (P<0.05) in 2% AC group compared to that of control. This study suggest that dietary AC may improve the external quality of edible meat and reduced antibiotics residue in chicken eggs without affecting laying performance.

• Journal of Life Science
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• v.19 no.5
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• pp.573-580
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• 2009

It has been previously reported that the carboxyl terminal residues 276 and 277 of ${\alpha}$-tropomyosin are important for actin affinity. In order to investigate actin affinities of these two residues of skeletal (HA) and smooth (QT) muscle ${\alpha}$-tropomyosins, a series of mutant tropomyosins were constructed in which residues at either 276 or 277 were individually replaced with a cysteine residue for chemical modification. These mutants were overexpressed in E. coli as unacetylated and Ala-Ser (AS) dipeptide fusion forms. While actin affinities of unacetylated tropomyosins were considerably low, those of AS/TMs were remarkably higher than those of corresponding unacetylated tropomyosins. However, actin affinities of AS/TM24 (QC) and AS/TM29 (HC) were dramatically lower than those of other AS/TMs and were close to those of unacetylated tropomyosins. In addition, actin affinities of unacetylated TM24 (QC) and TM29 (HC) failed to be restored in the presence of troponin, unlike unacetylated TM10 (HA) and TM23 (CA). These results indicated that the presence of a cysteine residue at 277 caused a drastic decrease in actin affinity, and also that the residue 277 is important for actin affinity of ${\alpha}$-tropomyosin. Since TM23 (CA) showed high actin affinity, it may serve as a valuable tool for chemical modification studies for investigating the interaction of the carboxyl terminal residues of ${\alpha}$-tropomyosin with actin and/or troponin.

• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.173-180
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• 2015

Environmental pesticides used for insect control can be transferred from plants to animals even to livestock animals through food chain. Human beings also can be exposed to pesticides by consuming polluted dairy products, including meats, eggs and other milk products. Therefore, the Ministry of Food and Drug Safety (MFDS) established Standard for Pesticide Residue Limits in dairy products. The QuEChERS (quick, easy, cheap, effective, rugged and safe) methods for detecting residual pesticides are relatively well established for fruits and vegetables, however, the methods for meat have not been appropriately studied yet. In the present work, pyraclofos was used as an organophosphate pesticide to examine its tissue residue in experimental animals by QuEChERS methods. For this, pyraclofos (150 mg/kg body weight) was orally administered to male rats once a day for 2 days. After 6, 12, and 24 hr of the treatment, the tissue residues in liver and femoral muscle of the rats were determined using QuEChERS methods followed by HPLC analyses. In preliminary studies, the recovery rates of spiking samples of pyraclofos demonstrated approximately 109~110% from the tissues. In previous study, pyraclofos tissue residues were observed with significantly high levels in livers and muscles at 6 hr of oral treatment. Then, they were almost completely disappeared after 24 hr of the administration, indicating the orally exposed pyraclofos is rapidly absorbed and distributed to body organs, then quickly excreted from the body with a negligible level of tissue residue. The alterations in blood chemistry as well as the histopathology of heart, lung, liver, spleen and kidney have also been investigated in the experimental animals for assessing acute toxic effects of pyraclofos. The obtained blood chemistry indexes (ALT and AST) showed maximum peak values at 12 hr after the oral administration and decreased to the normal levels at 24 hr of the treatment. Histopathologic observation exhibited acute hepatic damages at 24 hr of the treatment. In conclusion, we suggest that QuEChERS method can be adequately optimized for the analysis of pyraclofos residues in animal tissues.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.257-266
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• 1999

Ivermectin is a widely used broad spectrum antiparasitic agent in veterinary medicine. In this work, we examined the pharmacokinetic parameters and the tissue residue profile of a new injectable formulation of ivermectin developed for pigs. The plasma ivermectin levels reached the peak at about 9 and 2 hours after the administrations in young and adult pigs, respectively. But the elimination half-life (3-3.5 days) and the $C_{max}$ values (24~28 ng/ml) were not significantly different between young and adult pig groups. When compared to the reference formulation, the $C_{max}$ of test formulation was higher and $T_{1/2}$ values were shorter than those of the reference formulation, respectively. The tissue residue levels were dose- and time-dependent and were higher in the liver and fat, than in the other tissues such as the injection sites, the kidney, intestine, muscle, plasma (4~74 ng/g) at the 7th day after the administration of both formulations of ivermectin. Then, the mean tissue ivermectin levels at the 21st day after the administration in all the tissues decreased to 7.4 and 25% of the 7th day levels in the test and reference formulations, respectively. In general, the tissue levels of ivermectin in the animals treated with the test formulation decreased more rapidly than those with the reference formulation. The tissue to plasma distribution ratio (T/P ratio) of ivermectin was higher in the liver and fat than other tissues. The T/P ratio in the liver of animals treated with the test formulation was somewhat higher than that in the animals treated with the reference formulation. Taken together, the results of pharmacokinetic and tissue residue studies indicate that the test formulation of ivermectin for subcutaneous injection is comparable to the reference formulation, but unique in that it has higher peak plasma concentrations, shorter elimination half-life and higher T/P ratio in the liver than the reference formulation.

• Journal of fish pathology
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• v.35 no.2
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• pp.195-203
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• 2022

This study was performed to delineate pharmacokinetic residue characteristics of lincomycin (LM) in olive flounder at low water temperature (13℃), and to examine whether LM is effective against main Gram-negative pathogens. It was observed that the times for residue declined below the maximal residue limit (0.1 mg/kg) in the muscle was, respectively, 32, 33 and 55 days following 10, 20 and 40 mg/kg intramuscular LM injections. The in vitro MIC value of LM against Edwardsiella piscida was higher than 256 ㎍/mL and against Vibrio harveyi 32 ㎍/mL when examined with several clinical isolates. These results suggest that the withdrawal time of LM should be more than 30 days in consideration of the 10 mg/kg employed as the regular clinical dose. It was also found that LM administered to treat streptococosis in olive flounder is not likely to be effective against some pathogenic Gram-negative bacteria.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.164-168
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• 2006

The residue depletion of ampicillin was investigated in the olive flounder (Paralichthys olivaceus), rockfish (Sebastes schlegeli), and red sea bream (Pagrus major) after 5 days treatment with medicated feed at a dose of 100 mg/kg bw/day. Fishes were sampled for muscle on 1st, 2nd, 3rd, and 4th day after treatment. Ampicillin concentrations were determined by high performance liquid chromatography after SPE column extraction. The recovery rates of ampicillin in muscle samples ranged 94-98% and 83-88% for the concentration of 0.05 mg/kg and 0.1 mg/kg, respectively. Ampicillin concentrations detected on 1st day after treatment were 0.143, 0.138, and 0.187 mg/kg in the muscle of olive flounder, rockfish, and red sea bream, respectively. After a withdrawal of 3 days, muscle concentrations were 0.016, 0.012, and 0.021 mg/kg in the olive flounder, rockfish, and red sea bream, respectively. Ampicillin was not detectable in muscle samples on 4 days following withdrawal of the medicated feed. From results of the present study, a withdrawal period of ampicillin is proposed on 5 days after 5 days treatment with medicated feed at a dose of 100 mg/kg bw/day to avoid the presence of excessive residues of the edible muscles of olive flounder, rockfish, and red sea bream.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.244-249
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• 2006

The residue depletion of amoxicillin was investigated in the olive flounder (Paralichthys olivaceus), rockfish (Sebastes schlegeli), and red sea bream (Pagrus major) after 7 days treatment with medicated feed at a dose of 400 mg/kg bw/day. Fishes were sampled for muscle on 1st, 2nd, 3rd, 4th, and 5th day after treatment. Amoxicillin concentrations were determined by high performance liquid chromatography with fluorescence detector. The recovery rates of amoxicillin in muscle samples ranged 84.3-101.3% and 75.0-91.5% for the concentration of 0.05 mg/kg and 0.1 mg/kg, respectively. Amoxicillin concentrations detected on 1st day after treatment were 0.137, 0.131, and 0.172 mg/kg in the muscle of olive flounder, rockfish, and red sea bream, respectively. After a withdrawal of 3 days, muscle concentrations were 0.012, 0.010, and 0.017 mg/kg in the olive flounder, rockfish, and red sea bream, respectively. Amoxicillin was not detectable in muscle samples on 4 days following withdrawal of the medicated feed. From results of the present study, a withdrawal period of amoxicillin is proposed on 4 days after 7 days treatment with medicated feed at a dose of 400 mg/kg bw/day to avoid the presence of excessive residues of the edible muscles of olive flounder, rockfish, and red sea bream.

• Journal of fish pathology
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• v.31 no.2
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• pp.115-122
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• 2018

The Houttuynia cordata has been utilized for various beneficial purposes in humans mainly because of its potent antioxidant principle quercitrin present in this plant. This study examines the possibility of producing a functional sea food commodity containing active principle quercitrin by feeding H. cordata for a extended period. Spotted sea bass (Lateolabrax maculatus) were fed a diet containing H. cordata at 0.1-1.0% levels for 1 month and tissue concentrations of quercitrin were analyzed in serum, hepatopancreas and muscle. It was observed that quercitrin was found in the ranking order of hepatopancreas>muscle>serum. After a bolus administration of quercitrin (20 mg/kg, oral) to spotted sea bass and Nile tilapia (Oreochromis niloticus), idential rank order was observed after 48 hr. In contrast, the order was liver>serum>muscle in rat and mice, indicating that higher quercitrin distribution occurs to the muscle in fishes compared with in mammals tested. High residue concentration of qeurcitrin in the edible tissue can be an advantageous property in terms of functional food production. High level H. cordata extract inclusion of 1.0% seems to have detrimental effects in spotted sea bass leading to growth retardation and hepatic damage. It was concluded that incorporation of H. cordata extract into diet can be a way of producing healthy foods. However the level of active extract needs fine tuning to avoid toxicity to fishes.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.19-23
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• 2013

A simple and rapid method has been developed and validated for simultaneous determination of each macrolides residues (spiramycin, josamycin, tilmicosin, tylosin) in chicken muscle by high-performance liquid chromatography- photo diode array (HPLC-PDA). Chicken muscle sample have been extracted with liquid-liquid extraction process; analytes was extracted by acetonitrile, and then defatted with hexane saturated by acetonitrile. The HPLC separation was performed on a Unison UK-$C_{18}$ ($150mm{\times}3.0mm$, $3{\mu}m$) with a gradient system of 0.1% trifloroacetic acid (TFA) and 0.1% trifloroacetic acid (TFA) in acetonitrile as the mobile phase. The drugs were detected at 232 nm for spiramycin and josamycin, and 287 nm for tilmicosin and tylosin. The limits of quantification (LOQs) were between 27 and $59{\mu}g/kg$; and the intra- and inter-day precision (relative standard deviation; RSD) was between 0.9-13.2 and 2.4-13.1%, respectively in chicken muscle sample. The method may has been successfully applied for multiresidue determination of four macrolides below the maximum residue limits (MRLs) established by the European Union (EU).