• Biomolecules & Therapeutics
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• v.23 no.6
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• pp.597-603
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• 2015

Synthetic cannabinoids JWH-018 and JWH-250 in 'herbal incense' also called 'spice' were first introduced in many countries. Numerous synthetic cannabinoids with similar chemical structures emerged simultaneously and suddenly. Currently there are not sufficient data on their adverse effects including neurotoxicity. There are only anecdotal reports that suggest their toxicity. In the present study, we evaluated the neurotoxicity of two synthetic cannabinoids (JWH-081 and JWH-210) through observation of various behavioral changes and analysis of histopathological changes using experimental mice with various doses (0.1, 1, 5 mg/kg). In functional observation battery (FOB) test, animals treated with 5 mg/kg of JWH-081 or JWH-210 showed traction and tremor. Their locomotor activities and rotarod retention time were significantly (p<0.05) decreased. However, no significant change was observed in learning or memory function. In histopathological analysis, neural cells of the animals treated with the high dose (5 mg/kg) of JWH-081 or JWH-210 showed distorted nuclei and nucleus membranes in the core shell of nucleus accumbens, suggesting neurotoxicity. Our results suggest that JWH-081 and JWH-210 may be neurotoxic substances through changing neuronal cell damages, especially in the core shell part of nucleus accumbens. To confirm our findings, further studies are needed in the future.

• Toxicological Research
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• v.34 no.3
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• pp.191-197
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• 2018

In 2015, a candidate for the second national reference standard (NRS) of Gloydius snake venom was produced to replace the first NRS of Gloydius snake venom. In the present study, the potencies of the candidate were determined by a collaborative study, and the qualification of the candidate was estimated. The potencies of the candidate were determined by measuring the murine lethal titers and lapine hemorrhagic titers of venom against the regional working reference standard (RWRS) for antivenom using the methods described in the previous report for the first NRS of Gloydius snake venom. Three Korean facilities contributed data from a total of 30 independent assays. Subsequently, two foreign national control research laboratories contributed to this collaborative study. The results were calculated using the Reed-Muench method for lethality and determined using a mixed-effects model for hemorrhage. The general common potencies of the lethal and hemorrhagic titers were obtained from the results of the 30 tests performed at three Korean facilities. The results are expressed in micrograms for 1 test dose (TD) with a 95% confidence interval as follows: a lethal titer of $90.13{\mu}g/TD$ (95% confidence interval = $87.39{\sim}92.86{\mu}g$) and a hemorrhagic titer of $10.80{\mu}g/TD$ (95% confidence interval = $10.46{\sim}11.14{\mu}g$). In addition, the candidate preparation showed good quality evaluation according to the results of the quality estimation of the candidate and is judged to be suitable to serve as the Korean NRS for snake venom. In conclusion, the second NRS of Gloydius snake venom was established in this study and will be used for national quality control, including a national lot release test of Korean antivenom products.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.288-295
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• 2017

The incidence of polypharmacy-which can result in drug-drug interactions-has increased in recent years. Drug-metabolizing enzymes and drug transporters are important polypharmacy modulators. In this study, the effects of bosentan and rifampin on the expression and activities of organic anion-transporting peptide (OATP) and cytochrome P450 (CYP450) 2C9 and CYP3A4 were investigated in vitro. HEK293 cells and primary human hepatocytes overexpressing the target genes were treated with bosentan and various concentrations of rifampin, which decreased the uptake activities of OATP transporters in a dose-dependent manner. In primary human hepatocytes, CYP2C9 and CYP3A4 gene expression and activities decreased upon treatment with $20{\mu}M$ $bosentan+200{\mu}M$ rifampin. Rifampin also reduced gene expression of OATP1B1, OATP1B3, and OATP2B1 transporter, and inhibited bosentan influx in human hepatocytes at increasing concentrations. These results confirm rifampin- and bosentan-induced interactions between OATP transporters and CYP450.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1276-1280
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• 2017

The mcr-1 gene is a new "superbug" gene discoverd in China in 2016 that makes bacteria highly resistant to the last-resort class of antibiotics. The mcr-1 gene raised serious concern about its possible global dissemination and spread. Here, we report a potential anti-resistant strategy using the CRISPR/Cas9-mediated approach that can efficiently induce mcr-1 gene knockout in Escherichia coli. Our findings suggested that using the CRISPR/Cas9 system to knock out the resistance gene mcr-1 might be a potential anti-resistant strategy. Bovine myeloid antimicrobial peptide-27 could help deliver plasmid pCas::mcr targeting specific DNA sequences of the mcr-1 gene into microbial populations.

• Korean Journal of Community Nutrition
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• v.20 no.6
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• pp.399-410
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• 2015

Objectives: This study aims to identify self-resilience factors that drive right dietary and food safety practices in middle school students. Methods: Data was collected from 438 middle school students in Daegu using a self-administered questionnaire in December, 2013. The questionnaire consisted of 81 items with the following categories: general information, self-resilience, right dietary and food safety practices. Statistical analyses to determine frequency, average, ANOVA, factor analysis, reliability analysis, and regression analysis were performed using SPSS 21. Results: The results of factor analysis indicated that self-resilience was classified into challenge, adaptability, patience and achievement needs, and right dietary practices were sub-grouped into family meals, experience of dietary life, eco-friendly, balanced food, economy and bad food control, and food safety practices consisted of management of bacteria, hand washing and eating off a plate, safety food and food purchasing. The score of right dietary and food safety practices showed significant differences by sex, grade, and school achievement (p < 0.05). The economy factor of right dietary practices was significantly affected by the management of bacteria (p < 0.001), hand washing and eating off a plate (p < 0.001), safety food (p < 0.01), food purchasing of food safety practices (p < 0.05). The challenge factor of self-resilience significantly affected family meals, experience of dietary life, balanced food, economy, bad food control, management of bacteria, hand washing and eating off a plate, and safety food (p < 0.05). The adaptability factor of self-resilience was associated with factors such as eco-friendly, balanced food, economy, bad food control, management of bacteria, hand washing and eating off a plate, and food purchasing (p < 0.05). Conclusions: This study suggests that dietary education programs for middle school students could incorporate food safety practices, and self-resilience such as challenge, adaptability, patience and achievement needs to be effective.

• Korean Journal of Environmental Agriculture
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• v.38 no.1
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• pp.1-9
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• 2019

BACKGROUND: Accurate and simple analytical method determining Fluxametamid residue was necessary in various food matrices. Additionally, fulfilment of the international guideline of Codex (Codex Alimentarius Commission CAC/GL 40) was required for the analytical method. In this study, we developed Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method to determine the Fluxametamid residue in foods. METHODS AND RESULTS: Fluxametamid was extracted with acetonitrile, partitioned and concentrated with dichloromethane. To remove the interferences, silica SPE cartridge was used before LC-MS/MS (Liquid Chromatography-Tandem Mass Spectrometry) analysis with $C_{18}$ column. Five agricultural commodities (mandarin, potato, soybean, hulled rice, and red pepper) were used as a group representative to verify the method. The liner matrix-matched calibration curves were confirmed with coefficient of determination ($r^2$) greater than 0.99 at calibration range of 0.001-0.25 mg/kg. The limits of detection and quantification were 0.001 and 0.005 mg/kg, respectively. Mean average accuracies were shown to be 82.24-115.27%. The precision was also shown to be less than 10% for all five samples. CONCLUSION: The method investigated in this study was suitable to the Codex guideline for the residue analysis. Thus, this method can be useful for determining the residue in various food matrices as routine analysis.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.124-129
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• 2013

The method for detection foods containing allergenic materials by PCR was developed in this study. To detect allergenic raw material from processed food, species specific primer which up to 200bp for PCR product were designed or selected from advanced research. As target materials, 14 items were selected (12 target materials for allergen in Korea, 2 target materials for allergen in foreign countries). The amplicon size for eggs, milk, buckwheat, peanuts, beans, wheat, mackerel, crab, shrimp, pork, peach, tomato, almond, and sesame were confirmed 281, 131, 138, 120, 118, 127, 211, 174, 231, 138, 174, 132, 103, and 220bp, respectively. And any non-specific bands were not detected among each others. Detection method for allergenic material developed in this study could be used to investigate inaccurate goods for allergen labeling or non-intentional contaminant during processed foods manufacturing. In addition, the system will be usefully to detection accurate allergenic raw materials of export for other countries.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.68-73
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• 2012

In this study, a method was developed using molecular biological technique to distinguish an authenticity of meats for processed meat products. The genes for distinction of species about meats targeted at 12S or 16S genes in mitochondrial DNA and the species-specific primers were designed by that PCR products' size was around 200bp for applying to processed products. The target materials were 10 species of livestock products and it checked whether expected PCR products were created or not by electrophoresis after PCR using species-specific primers. The results of PCR for beef, pork, goat meat, mutton, venison, and horse meat were 131, 138, 168, 144, 191, and 142 bp each. The expected PCR products were confirmed at 281, 186, 174, and 238 bp for chicken, duck, turkeymeat, and ostrich. Also, non-specific PCR products were not detected in similar species by species-specific primers. The method using primers developed in this study confirm to be applicable for composite seasoning including beefs and processed meat products including pork and chicken. Therefore, this method may apply to distinguish an authenticity of meats for various processed products.

• Korean Journal of Community Nutrition
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• v.9 no.5
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• pp.597-605
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• 2004

The purpose of the study was to investigate relationships among food safety training, knowledge, and practices of school food service employees. A questionnaire that identified employees' food safety training experience, knowledge, and practices was developed based on a review of literature. A total of 341 Korean school food service employees participated in the survey; the final usable responses were 293 (a response rate: 86%). Statistical analyses were conducted using SPSS for Windows (version 10). Most of the respondents (> 86%) took training sessions on 'proper hand washing' and 'proper food storage temperatures', whereas less than 60% had training on 'monitoring procedures and corrective actions at critical control points'. The mean score of their food safety knowledge was 8.02 out of 11. The majority of the employees knew correctly 'potentially hazardous foods (93.2%)' and 'diseases and symptoms with which they are excluded from working (87.0%)'; less than 50% chose a correct answer for 'sanitizing food contact surfaces.' A chi-square analysis revealed that the employees' actual knowledge did not differ significantly by whether they had food safety training (at the level of a =0.01), except one topic 'diseases and symptoms with which they are excluded from working.' Their self-reported practice scores were rated as 2.98 - 3.39 based on a 5-point Likert-type scale (1-not at all, 5-always). Employees' food safety training should be conducted continuously and repetitively to improve the effectiveness of the training.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.296-305
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• 2018

Spiroxamine, one of fungicides, is used to control powdery mildew in various crops and black yellow sigatoka in bananas. The major strength of spiroxamine is to control powdery mildew in various crops and bananas yellow sigatoka in bananas. The compound has shown a high level of activity, good persistence and crop tolerance. Besides powdery mildew, good control of rust, net blotch and Rhynchosporium diseases been indicated in cereals, together with a complementary activity against Septoria diseases. In 2017, the maximum residue limit (MRL) of spiroxamine established in Korea. According to Ministry of ood and rug afety) regulations, spiroxamine residues defined only parent compound. Thus, a analytical method is needed to estimate the residue level of the parent compound. The objective of this study was to develop and validate analytical method for spiroxamine in representative agricultural commodities. Samples were extracted with acetonitrile and partitioned with dichloromethane to remove the interfering substances. The analyte were quantified and confirmed liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.0005{\sim}0.1{\mu}g/mL$) for the analyte in blank extract with coefficient of determination ($r^2$) > 0.99. For validation purposes, recovery studies will be carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries 70.6~104.6% with relative standard deviations (RSDs) less than 10%. All values were consistent with the criteria ranges in the Codex guidelines (CAC/GL40, 2003) and MFDS guidelines. proposed analytical method be used as an official analytical method in the Republic of Korea.