• 분석과학
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• 제34권1호
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• pp.1-8
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• 2021

An analytical method was developed and optimized for the quantification of a plant growth regulator, 2,6-diisopropylnaphthalene (2,6-DIPN), in agricultural products using gas chromatography-tandem mass spectrometry. The samples were extracted, partitioned, and were purified using a Florisil® cartridge. To validate the analytical method, its specificity, linearity, limit of detection (LOD) and limit of quantification (LOQ) of the instrument, LOQ of the analytical method (MLOQ), accuracy, and repeatability were considered. The method displayed excellent results during validation, and is suitable for the determination and quantification of the low residual levels of the analyte in the agricultural samples. All of the results with the optimized method were satisfactory and within the criteria ranges requested in the Codex Alimentarius Commission guidelines and the Ministry of Food and Drug Safety guidelines for pesticide residue analysis. The developed method is simple and accurate and can be used as a basis for safety management of 2,6-DIPN.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.266-271
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• 2017

Synthetic cannabinoids are one of most abused new psychoactive substances. The recreational use of abused drug has aroused serious concerns about the consequences of these drugs on infection. However, the effects of synthetic cannabinoid on resistance to tetanus toxin are not fully understood yet. In the present study, we aimed to determine if the administration of synthetic cannabinoids increase the susceptibility to tetanus toxin-induced motor behavioral deficit and functional changes in cerebellar neurons in mice. Furthermore, we measured T lymphocytes marker levels, such as CD8 and CD4 which against tetanus toxin. JWH-210 administration decreased expression levels of T cell activators including cluster of differentiation (CD) $3{\varepsilon}$, $CD3{\gamma}$, CD74p31, and CD74p41. In addition, we demonstrated that JWH-210 induced motor impairment and decrement of vesicle-associated membrane proteins 2 levels in the cerebellum of mice treated with tetanus toxin. Furthermore, cerebellar glutamatergic neuronal homeostasis was hampered by JWH-210 administration, as evidenced by increased glutamate concentration levels in the cerebellum. These results suggest that JWH-210 may increase the vulnerability to tetanus toxin via the regulation of immune function.

• Biomolecules & Therapeutics
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• 제25권6호
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• pp.659-664
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• 2017

Although lisdexamfetamine is used as a recreational drug, little research exists regarding its potential for dependence or its precise mechanisms of action. This study aims to evaluate the psychoactivity and dependence profile of lisdexamfetamine using conditioned place preference and self-administration paradigms in rodents. Additionally, biochemical techniques are used to assess alterations in the dopamine levels in striatal synaptosomes following administration of lisdexamfetamine. Lisdexamfetamine increased both conditioned place preference and self-administration. Moreover, after administration of the lisdexamfetamine, dopamine levels in the striatal synaptosomes were significantly increased. Although some modifications should be made to the analytical methods, performing high performance liquid chromatography studies on synaptosomes can aid in predicting dependence liability when studying new psychoactive substances in the future. Collectively, lisdexamfetamine has potential for dependence possible via dopaminergic pathway.

• Biomolecules & Therapeutics
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• 제23권4호
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• pp.386-389
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• 2015

Sibutramine is an anorectic that has been banned since 2010 due to cardiovascular safety issues. However, counterfeit drugs or slimming products that include sibutramine are still available in the market. It has been reported that illegal sibutramine-contained pharmaceutical products induce cardiovascular crisis. However, the mechanism underlying sibutramine-induced cardiovascular adverse effect has not been fully evaluated yet. In this study, we performed cardiovascular safety pharmacology studies of sibutramine systemically using by hERG channel inhibition, action potential duration, and telemetry assays. Sibutramine inhibited hERG channel current of HEK293 cells with an $IC_{50}$ of $3.92{\mu}M$ in patch clamp assay and increased the heart rate and blood pressure ($76{\Delta}bpm$ in heart rate and $51{\Delta}mmHg$ in blood pressure) in beagle dogs at a dose of 30 mg/kg (per oral), while it shortened action potential duration (at $10{\mu}M$ and $30{\mu}M$, resulted in 15% and 29% decreases in $APD_{50}$, and 9% and 17% decreases in $APD_{90}$, respectively) in the Purkinje fibers of rabbits and had no effects on the QTc interval in beagle dogs. These results suggest that sibutramine has a considerable adverse effect on the cardiovascular system and may contribute to accurate drug safety regulation.

• 한국식품위생안전성학회지
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• 제29권1호
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• pp.47-52
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• 2014

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

• 한국환경농학회지
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• 제39권3호
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• pp.246-252
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• 2020

BACKGROUND: Pesticides are broadly used to control weeds and pests, and the residues remaining in crops are managed in accordance with the MRLs (maximum residue limits). Therefore, an analytical method is required to quantify the residues, and we conducted a series of analyses to select and validate the quick and simple analytical method for tolpyralate in five agricultural products using QuEChERS (quick, easy, cheap, effective, rugged and safe) method and LC-MS/MS (liquid chromatography-tandem mass spectrometry). METHODS AND RESULTS: The agricultural samples were extracted with acetonitrile followed by addition of anhydrous magnesium sulfate, sodium chloride, disodium hydrogencitrate sesquihydrate and trisodium citrate dihydrate. After shaking and centrifugation, purification was performed with d-SPE (dispersive-solid phase extraction) sorbents. To validate the optimized method, its selectivity, linearity, LOD (limit of detection), LOQ (limit of quantitation), accuracy, repeatability, and reproducibility from the inter-laboratory analyses were considered. LOQ of the analytical method was 0.01 mg/kg at five agricultural products and the linearity of matrix-matched calibration were good at seven concentration levels, from 0.0025 to 0.25 mg/L (R²≥0.9980). Mean recoveries at three spiking levels (n=5) were in the range of 85.2~112.4% with associated relative standard deviation values less than 6.2%, and the coefficient of variation between the two laboratories was also below 13%. All optimized results were validated according to the criteria ranges requested in the Codex Alimentarius Commission (CAC) and Ministry of Food and Drug Safety (MFDS) guidelines. CONCLUSION: In conclusion, we suggest that the selected and validated method could serve as a basic data for detecting tolpyralate residue in imported and domestic agricultural products.

• 한국환경농학회지
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• 제32권3호
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• pp.207-213
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• 2013

Thidiazuron은 1976년 Plant Physiology 발표를 통해 생장조정제로 알려진 이후, 현재 우리나라에서도 생장조정제로 수박과 참외의 착과 증진 및 참다래의 과실비대 촉진, 포도의 과립 비대 증진 및 착립 증진 등을 위해 등록되어 사용되고 있다. Thidiazuron의 분석법은 식품공전에 수재되어 있으나, 등재 당시의 기술 이용, 일부 시험 대상 품목에 대한적용 등으로, 최근의 잔류허용기준 설정 품목의 증가와 분석기기 및 기술 발달을 반영하여 검증된 분석법으로 개선코자 하였다. 더불어, 개발된 분석법을 활용하여, thidiazuron의 사용이 허가되어 있는 수박, 키위, 포도를 포함한 국민 다소 비 식품 17품목에 대한 잔류실태조사도 수행하였다. 개발된 분석법의 회수율은, 현미 89.2~91.2 %, 고추 87.2~92.1 %, 감자 76.4~86.9 %, 수박 91.2~95.7 %, 키위 86.5~88.5 %, 포도 89.5~94.0 % 였으며, 반복 회수율 간 변이계수는 10 % 이하였다. 또한 개발된 분석법으로 우리나라에서 유통되고 있는 다소비 농산물 쌀, 상추, 사과 등 17품목 358건에 대해 농약 잔류실태를 조사한 결과 모든 시료에서 thidazulon은 검출되지 않았다.

• 한국환경농학회지
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• 제41권4호
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• pp.288-309
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• 2022

BACKGROUND: The objective of this study was to develop a comprehensive and simple method for the simultaneous determination of 59 veterinary drug residues in livestock products for safety management. METHODS AND RESULTS: For sample preparation, we used a modified liquid extraction method, according to which the sample was extracted with 80% acetonitrile followed by incubation at -20℃ for 30 min. After centrifugation, an aliquot of the extract was evaporated to dryness at 40℃ and analyzed using liquid chromatography combined with tandem mass spectrometry. The method was validated at three concentration levels for beef, pork, chicken, egg, and milk in accordance with the Codex Alimentarius Commission/Guidelines 71-2009. Quantitative analysis was performed using a matrix-matched calibration. As a results, at least 52 (77.6%) out of 66 compounds showed the proper method validation results in terms of both recovery of the target compound and coefficient of variation required by Codex guidelines in livestock products. The limit of quantitation of the method ranged from 0.2 to 1119.6 ng g-1 for all matrices. CONCLUSION(S): This method was accurate, effective, and comprehensive for 59 veterinary drugs determination in livestock products, and can be used to investigate veterinary drugs from different chemical families for safety management in livestock products.

• Biomolecules & Therapeutics
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• 제22권6호
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• pp.558-562
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• 2014

Tramadol is an opioid analgesic agent that has been the subject of a series of case reports suggesting potential for misuse or abuse. However, it is not a controlled substance and is not generally considered addictive in Korea. In this study, we examined the dependence potential and abuse liability of tramadol as well as its effect on the dopaminergic and serotonergic systems in rodents. In animal behavioral tests, tramadol did not show any positive effects on the experimental animals in climbing, jumping, and head twitch tests. However, in the conditioned place preference and self-administration tests, the experimental animals showed significant positive responses. Taken together, tramadol affected the neurological systems related to abuse liability and has the potential to lead psychological dependence.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2004년도 제3회 식품안전의 날 기념 학술 세미나
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• pp.245-245
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• 2004