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Residual analysis of veterinary drugs in bovine and equine muscle by targeted sampling plan in 2022
Sunjin Park(Sunjin Park),Chung-Oui Hong(Chung-Oui Hong),Se-Hyung Kim(Se-Hyung Kim),Jihye Kim(Jihye Kim),Inhae Jeon(Inhae Jeon),Seon-Young Lee(Seon-Young Lee),Moon Her(Moon Her),Sung-Won Park(Sung-Won 한국예방수의학회 2023 예방수의학회지 Vol.47 No.2
The Animal and Plant Quarantine Agency conducts a targeted sampling plan and analysis for veterinary drugs within the country every year. Target compounds included tetrachlorvinphos as an organophosphate, diminazene as an anti-infective medication, ketoprofen as a nonsteroidal anti-inflammatory drug, triclabendazole and clorsulon as flukicides in 2022. These compounds were not included in National Residues Program (NRP), despite their high sales ranking. A total of 94 bovine muscle samples and 20 equine muscle samples were collected from various locations across the country. The analysis of target compounds in muscle was performed using LC-MS/MS coupled with Food code 8.3.1 revised in 2022. A 2 g sample of muscle tissue was extracted using a water: acetonitrile (1:4, v/v) solution, then cleaned up with C18 and hexane saturated with acetonitrile. Compounds were separated with C18 column and mobile phases consisted of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). All analytes exhibited good linearity with correlation coefficients (R2) higher than 0.992. The limit of quantification (LOQ) of these compounds ranged from 0.21 to 2.79 μg/kg except for diminazene (3.85~6.86 μg/kg). The average recoveries of these analytes were 89.45~129.13% in muscle at spiked level of 10 or 20 μg/kg. Relative standard deviations (%) (intra-day and inter-day) were lower than 20% for all target compounds, except for diminazene and triclabendazole, whose intra-day RSD % was slightly higher than 20% in equine muscle. Testing confirmed that all 94 bovine and 20 equine muscle samples from 9 provinces were free from residues of veterinary drugs. Monitoring of compounds not included in the NRP should continue to ensure consumer health and food safety.
Kim, Hyeongmin,Lee, Taeheon,Park, WonCheoul,Lee, Jin Woo,Kim, Jaemin,Lee, Bo-Young,Ahn, Hyeonju,Moon, Sunjin,Cho, Seoae,Do, Kyoung-Tag,Kim, Heui-Soo,Lee, Hak-Kyo,Lee, Chang-Kyu,Kong, Hong-Sik,Yang, Yo Oxford University Press 2013 DNA research Vol.20 No.3
<P>The modern horse (<I>Equus caballus</I>) is the product of over 50 million yrs of evolution. The athletic abilities of the horse have been enhanced during the past 6000 yrs under domestication. Therefore, the horse serves as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. The structure and function of skeletal muscle show remarkable plasticity to the physical and metabolic challenges following exercise. Here, we reveal an evolutionary layer of responsiveness to exercise-stress in the skeletal muscle of the racing horse. We analysed differentially expressed genes and their co-expression networks in a large-scale RNA-sequence dataset comparing expression before and after exercise. By estimating genome-wide <I>d</I><SUB>N</SUB>/<I>d</I><SUB>S</SUB> ratios using six mammalian genomes, and F<SUB>ST</SUB> and iHS using re-sequencing data derived from 20 horses, we were able to peel back the evolutionary layers of adaptations to exercise-stress in the horse. We found that the oldest and thickest layer (<I>d</I><SUB>N</SUB>/<I>d</I><SUB>S</SUB>) consists of system-wide tissue and organ adaptations. We further find that, during the period of horse domestication, the older layer (F<SUB>ST</SUB>) is mainly responsible for adaptations to inflammation and energy metabolism, and the most recent layer (iHS) for neurological system process, cell adhesion, and proteolysis.</P>
NMR and Fluorescence Studies of DNA Binding Domain of INI1/hSNF5
Lee, Dongju,Moon, Sunjin,Yun, Jihye,Kim, Eunhee,Cheong, Chaejoon,Lee, Weontae Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.9
INtegrase Interactor 1 protein (INI1/hSNF5) or BRG1-associated factor 47 (BAF47) is a SWI/SNF-related matrix associated actin dependent regulator of chromatin subfamily B member. DNA binding domain of INI1/hSNF5 is cloned into E.coli expression vectors, pET32a and purified as a monomer using size exclusion chromatography. NMR data show that $INI1^{DBD}$ has folded state with high population of ${\alpha}$-helices. By fluorescence-quenching experiments, binding affinities between $INI1^{DBD}$ and two double stranded DNA fragments were determined as $29.9{\pm}2.6{\mu}M$ (GAL4_1) and $258.7{\pm}5.8$ (GAL4_2) ${\mu}M$, respectively. Our data revealed that DNA binding domain of INI1/hSNF5 binds to transcriptional DNA sequences, and it could play an important role as a transcriptional regulator.
Sunjin Park,Chung-Oui Hong,Hyobi Kim,Yu-Jung Kim,Seon-Young Lee,Inhae Jeon,Kwang-jick Lee,Moon Her,Sung-Won Park 한국예방수의학회 2022 예방수의학회지 Vol.46 No.3
This study aims to establish a modified analytical method with sensitivity and reliability for streptomycin (STP) and dihydrostreptomycin (DHS) of residues level in pig tissues, plasma and urine by LC-MS/MS on the basis of previous studies. The mass parameters of quantitative and qualitative ions for STP and DHS were optimized using multiple reaction monitoring in positive mode. The separation of compounds was conducted using BEH Amide column according to material’s characteristics. The analytes in plasma were extracted with only organic solvents. In muscle and kidney, KH2PO4 buffer solution containing 2% CCl3COOH and EDTA-Na was used as extraction solvent. The WCX cartridege was selected as SPE cartridge in considering high recoveries for STP and DHS. The analytes in urine were extracted by organic solvents with acid and addition of EDTA. The limits of detection (LODs) in STP and DHS ranged 0.45~3.66 μg/kg and 0.22~0.78 μg/kg, respectively. The limits of quantification (LOQs) were 1.35~11.10 μg/kg in STP and 0.66~2.36 μg/kg in DHS. The recoveries (%) were 94.29~104.5% in STP and 92.32~108.45% in DHS except for plasma with lower values (61.45/68.5%, respectively). In the precision evaluation, the coefficient of variation (CV, %) of STP showed <10.50% on intra-day and <18.04% on inter-day. The CV (%) of DHS showed <8.42% on intra-day, whereas <17.98% on inter-day. The modified method is reliable for continuous residual monitoring in pig to ensure food safety for consumer’s health. In addition, this method could be used in study relation to residue depletion and pharmacokinetics of veterinary drug.
Lee, Yebin,Yang, Ilseung,Lee, Jung Eun,Hwang, Sunjin,Lee, Jong Woo,Um, Seung-Soo,Nguyen, Thanh Luan,Yoo, Pil J.,Woo, Han Young,Park, Juhyun,Kim, Seong Keun American Chemical Society 2013 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.117 No.7
<P>We show that Förster resonance energy transfer (FRET) between a conjugated oligoelectrolyte based on distyrylstilbene (DSSN+) and Nile red can enhance photocurrent generation when the photoagents are assembled vertically on gold electrodes. DSSN+ and Nile red intercalated into phospholipid membranes of unilamellar vesicles were found to form a useful FRET system because of the solvatochromic properties of DSSN+, and the accompanying photophysical properties were suitable for FRET with Nile red. As a result, a FRET efficiency of 93–94% was achieved, as shown by steady-state and time-resolved spectra in vesicle solutions. When Nile red was tethered in a self-assembled monolayer of 11-mercaptoundecanoic acid (MUA) on gold electrodes and phospholipid-assembled DSSN+ was sequentially organized on the MUA layer, the anodic photocurrent increased notably, reaching about 815 nA/cm<SUP>2</SUP> by virtue of FRET between the vertically aligned dyes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2013/jpccck.2013.117.issue-7/jp3117193/production/images/medium/jp-2012-117193_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp3117193'>ACS Electronic Supporting Info</A></P>
Targeted sampling analysis of nitrofuran metabolites in horse meats
Sunjin Park,Chung-Oui Hong,Hyobi Kim,Seon-Young Lee,Inhae Jeon,Yu-Jung Kim,Pil-Hee Kwak,Moon Her,Kwang-jick Lee 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7
The nitrofuran metabolites such as furazolidone (AOZ), furaltadone (AMOZ), nitrofurazone (SEM) and nitrofurantoine (AHD) are a class of drug typically used as antimicrobials. The defining structural component is a furan ring with nitro group. The nitrofurans are currently announced as a substance that should not be detected in food. However, it is being used for therapeutic purpose in the racing horses by the veterinarian prescription of the human medicine. Any residue of these compounds found in food producing animals has to be considered as a violation of the regulations. The 51 horse muscle samples were gathered by targeted sampling plan & analysis of Animal and Plant Quarantine Agency (APQA) at different horse farms from Jeju-do. The analysis of nitrofuran metabolites (AOZ, AMOZ, SEM and AHD) in horse meat were performed using LC-MS/MS. The 2g of horse muscle was extracted, derivatized and cleaned according to the Food Code. The separation of compounds was conducted using Waters XBridge C18 (2.1 mm × 150 mm, 3.5 μm) column at 35 ℃ with 0.4 mL/min flow rate. Mobile phase A and B were composed of water containing 0.1% formic acid and 10 mM ammonium formate and methanol, respectively. LC-MS/MS with multiple reaction monitoring was optimized for nitrofurans. The correlation coefficients (R2) for the calibration curves in the matrix were over 0.999 for nitrofurans. The limit of detection (LOD) and limit of quantification (LOQ) were 0.01 ~ 0.19 ppb and 0.03~ 0.59 ppb, respectively. The average recoveries were 105.7% at spiked level of 10 μg/kg. Relative standard deviations (%) were under 7.72% on intra-day. As a result of validated analysis, nitrofurans were not detected in any samples. According to the targeted sampling plan & analysis conducted in 2020, it was confirmed the 51 horse muscle samples in Jeju-do were free from contamination and the domestic horse meat is very hygienic without resides of nitrofurans. Continuous monitoring must be performed to ensure food safety for consumer’s health.
Sunjin Lee,Eunjin Gye,Juno Baik 서울대학교 언어교육원 2024 語學硏究 Vol.60 No.1
This study investigated the impact of learner factors on complexity, accuracy, and fluency (CAF) when performing tasks with varying levels of complexity. The study measured working memory, language anxiety, and the scale and intensity of social interaction among 25 intermediate and 30 advanced Korean learners, as well as native Korean speakers. The results showed that the complexity of spoken language production increased with more complex tasks at the expense of accuracy, particularly among second-language learners. Conversely, native speakers maintained consistent accuracy across different task types. These findings underscore the importance of tailoring task design and implementation to individual learner profiles, which is essential for optimizing task-based language-learning environments. This study advocates a balanced approach that aligns task demands with learner needs to enhance educational outcomes.