This study was conducted to reset the maximum residue limit (MRL) for didecyldimethylammonium chloride (DDAC) in broiler chickens. The disinfectant containing DDAC (10%, w/w) was diluted 160 times and evenly sprayed on the bodies of twenty-four broiler chickens at a rate of 15 mL per day per bird for 7 days. After the disinfectant treatment, tissue samples were collected from six broiler chickens at 0.25, 1, 3 and 5 days, respectively. Residual DDAC concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 2.0~10.0 μg/kg), recoveries (86.9~118.6%), and coefficient of variations (<19.98%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In all tissues except for liver, DDAC was detected more than LOQ at 5 days after the disinfectant treatment. In liver tissues, DDAC was detected more than LOQ at 3 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal period of DDAC in poultry tissues was established to 26 days. In conclusion, the developed analytical method is sensitive and reliable for detecting DDAC in poultry tissues. When DDAC disinfectant is sprayed on a poultry house in the presence of broiler chickens, it is necessary to keep the disinfectant from contacting the body of the livestock.

This study investigated ethopabate (EPB) residues in edible tissues of broiler chickens given in drinking water and established the withdrawal time (WT) of EPB in poultry tissues. Twenty-four healthy Ross broiler chickens were orally administered with EPB at the concentration of 3.8 mg/L for 14 days (EPB-1, n=24) and 15.2 mg/L for 7 days (EPB-2, n=24) through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3, and 5 days, respectively. EPB residue concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient values ranged from 0.9980 to 0.9998, and the limits of detection and quantification (LOQ) were 0.03~0.09 and 0.1~0.3 μg/kg, respectively. Mean recoveries in muscle, liver, kidney and skin/fat tissues were 95.9~109.8, 108.7~115.3, 89.9~96.6 and 86.7~96.8%, respectively, and coefficient of variations were less than 17.11%. At the end of the drug-administration period (0 day), EPB was detected at levels under the LOQ in all tissues from both the EPB-1 and EPB-2 groups. According to the results of EPB residue in Ross broiler tissues, withdrawal periods of both EPB-1 and EPB-2 in poultry tissues were established to 0 day. In conclusion, the developed analytical method is suitable for the detection of EPB in poultry tissues, and the estimated WT of EPB in poultry tissues will contribute to ensuring the safety of Ross broiler chickens.

From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for amprolium (APL) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with APL at the concentration of 60 mg/L (APL-1, n=24) for 14 days and 240 mg/L (APL-2, n=24) for 7 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3 and 5 days, respectively. Residual APL concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 0.3~5.0 μg/kg), recoveries (81.5~112.4%), and coefficient of variations (<15.5%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In APL-1, APL in all tissues except for kidney was detected less than LOQ at 3 days after drug treatment. In APL-2, APL in liver and kidney was detected more than LOQ at 5 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of APL-1 and APL-2 in poultry tissues were established to 3 and 2 days, respectively. In conclusion, the developed analytical method is sensitive and reliable for detecting APL in poultry tissues. The estimated WT of APL in poultry tissues is longer than the current WT recommendation of 2 days for APL in broiler chickens.

We investigated the role of the central MAPK pathways in extra-territorial (referred) pain resulting from inflammation of the temporomandibular joint (TMJ). Experiments were carried out on male Sprague-Dawley rats weighing 220-280 g. Under anesthesia, these animals were injected with 50 μL of complete Freund's adjuvant (CFA) into the TMJ using a Hamilton syringe. In the control group, saline was injected into the TMJ. To identify the extent of inflammation of the TMJ, Evans blue dye (0.1%, 5 mg/kg) was injected intravenously at 1, 3, 6, 9, 12 and 15 days after CFA injection. The concentration of Evans blue dye in the extracted TMJ tissue was found to be significantly higher in the CFA-treated animals than in the saline-treated group. Air-puff thresholds in the vibrissa pad area were evaluated 3 days before and at 3, 6, 9, 12, 15 and 18 days after CFA injection into the TMJ. Referred mechanical allodynia was established at 3 days, remained until 12 days, and recovered to preoperative levels at 18 days after CFA injection. This referred mechanical allodynia was observed in contralateral side area. To investigate the role of central MAPK pathways, MAPK inhibitors (10 μg) were administrated intracisternally 9 days after CFA injection. SB203580, a p38 MAPK inhibitor, significantly attenuated referred mechanical allodynia, as compared with the vehicle group. PD98059, a MEK inhibitor, also reduced CFA-induced referred mechanical allodynia. These results suggest that TMJ inflammation produces extra-territorial mechanical allodynia, and that this is mediated by central MAPK pathways.

We investigated whether sound could alter gene expression in plants. Using a sound-treated subtractive library, a set of sound-responsive genes in plants was demonstrated through mRNA expression analyses. Of them, the rbcS and ald genes, which are light responsive, up-regulated their expression with sound treatment in both light and in dark conditions. This suggested that sound could be used as a gene regulator instead of light. When we analyzed ald gene expression using various single wavelengths, a significant increase in mRNA levels was found at 125 or 250 Hz but decreased at 50 Hz, indicating that the gene responded to sound in a wavelength-specific manner. To determine whether the ald promoter respond to sound, we generated transgenic rice plants harboring the chimeric gene consisting of a 1,506-bp promoter fragment of the ald gene fused to Escherichia coli GUS reporter gene. Analyses of mRNA expressison level of three independent transgenic lines sound-treated with 50 or 250 Hz for 4 h showed that the Gus gene expression in all three transgenic lines was up regulated by 250 Hz, but down regulated by 50 Hz. These results correlated with sound responsive mRNA expression pattern observed for the ald gene in rice plants, indicating that the 1,506-bp ald promoter confers sound-responsiveness on a reporter gene in transgenic rice plants. We also investigated whether sound waves could improve salt tolerance in rice seedling. The rice seedlings were sound treated with 800 Hz for 1hr, and then treated with 0, 75, 150, and 225mM NaCl for 3 days to observe changes in physiological and morphological aspects. Sound treatment seedlings resulted in enhanced salt stress tolerance, mainly demonstrated by the sound treated seedlings exhibiting of increased root relative water contents (RWC), root length and weight, photochemical efficiency (ratio of variable to maximum fluorescence, Fv/Fm), and germination rate under salt stress condition. This demonstrates that a specific sound wave might be used, not only to alter gene expression in plant, but also to improve salt stress tolerance.

소맥의 품질특성규명 및 품질개선을 위한 기초자료를 얻고자 일연의 시험을 수행한바 그 결과를 요약하면 다음과 같다. 제분율은 품종에 따라 49~72%으로서 평균60.3%였으며 한국 재래종의 전체 평균은 62.6%를 보였다. 일반적으로 S.son, Caproch 그리고 CI 12703이 교배된 조합이 제분율이 높았다. 단백질 함량의 평균은 11.4%으로 품종에 따라 큰 차이가 있어 7-17%의 범위에 있고 한국 재래종의 평균 9.34%로 낮은 경향을 보였으나 수원 210호는 전체 평균보다 월등히 높았다. 침전가는 20cc 이하에서 70cc의 범위고 평균 43.6cc 였으며 한국 재래종은 낮았으나 수인210호는 높은 침전가를 보였다. Bb#1 Sturdy, 중국81 Atlas66 등 6개의 교배조합은 15.0% 이상의 단백질함량과 60.0cc 이상의 침전가를 보였으며 일반적으고 Bb#1 이 교배된 조합이 단백질함량과 침전가가 다른 조합보다 높았다. Pelshenke value의 분포는 20분 이하에서 180분 이상으로 평균 89.9분이었고 한국 재래종의 평균은 31.7분으로 극히 낮았다. 비침전가에 의하면 8.1%가 경질소맥인 반면 54.4%가 연질소맥, 37.5%가 중간질로 분류되었다. 329 공시계통(또는 품종)중 제분율, 단백질함량 및 침전가가 높은 교배조합은 Strampelli 69D-3607/Jogwang, S.son Caproch, Suweon #185 Toropi 그리고 Suweon #185 Ciano 였으며 Pribog, CT 14496 및 Sturdy Rcout/St rampelli Bb-Cno는 제분율은 높으나 단백질 함량과 침전가가 각각 9%, 30cc 이하로 낮았다.