• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.477-484
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• 2001

The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gut of the stomachless teleost, the Prussian carp, Carassius auratus Linnaeus, using 10 types of specific antisera raised against mammalian regulatory peptides. The gut of the Prussian carp was divided into five portions from proximal to distal (Segments I~V). Most of immunoreactive cells in the epithelial lining portion, between epithelial cells, were generally spherical or spindle shape having long cytoplasmic process that reached to the lumen (open typed cell) while cells showing round in shape (close typed cell) were found in the basal portions of epithelial lining occasionally. Somatostatin-, cholecystokinin (CCK)-8- and pancreatic polypeptide (PP)- immunoreactive cells were observed in this study. However, no serotonin-, glucagon-, chromogranin A-, secretin-, vasoactive intestinal peptide (VIP)-, substance P- and bombesin-immunoreactive cells were found. Somatostatin-immunoreactive cells were restricted to most proximal segments of the gut (Segment I) with rare frequency and CCK-8-immunoreactive cells were demonstrated in the proximal segments of the gut (Segments I and II) with a few to rare frequencies. In addition, pancreatic polypeptide-immunoreactive cells were demonstrated in the proximal to middle segments (Segments I~III) with moderated to rare frequencies. In conclusion, the distribution and relative frequency of these immunoreactive cells are well corresponded to the previous reports in stomachless teleost but somewhat peculiar patterns are also detected.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.289-297
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• 2002

The regional distribution and relative frequency of neurohormonal peptides-producing cells were demonstrated in the gut of the stomach teleost, the Mandarin fish, Siniperca scherzeri Steindachner, using 7 types of specific antisera raised against mammalian regulatory peptides. The gastrointestinal tract of the Mandarin fish was divided into three portions from proximal to distal, stomach, small intestine and large intestine. Cells showing immunoreactivities against regulatory peptides were situated in the epithelial lining, between epithelial cells, and gastric or intestinal gland regions with various frequencies along with gastrointestinal tract. Mast of immunoreactive cells in the epithelial lining portion were generally spherical or spindle shape having long cytoplasmic process that were reached to the lumen (open type cell) while cells showing round in shape (closed type cell) were found in the gastric gland of the stomach occasionally. Serctonin-, samatostatin-, gastrin-, cholecystokinin (CCK)-8- and human pancreatic polypeptide (HPP)-immunoreactive cells were observed in this study. However, no insulin- and glucagon-immunoreactive cells were found. Serotonin- and somatostatin-immunoreactive cells were restricted to the stomach regions with moderate and numerous frequencies, respectively. Gastrin-immunoreactive cells were demonstrated in the stomach and small intestinal portions with a few and moderate frequencies, respectively and CCK-8-immunoreactive cells were restricted to the small intestinal portions with moderate frequency. In addition, HPP-immunoreactive cells were demonstrated in the stomach and small intestine with numerous frequencies, respectively. In conclusion, the distribution and relative frequency of these immunoreactive cells in the gastrointestinal tract of the Mandarin fish shows peculiar patterns compared to those of other stomach and/or stomachless teleost.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.342-350
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• 2008

This study was carried out to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects. Thyroid function was also considered. Male and female Sprague-Dawley rats were gavaged daily with 0, 25, 50, 100 mg/kg metribuzin in corn oil during 30 days. The effects of metribuzin on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of metribuzin 50 mg/kg/day increased relative weight of testis, prostate, and seminal vesicle in male rats but relative weight of thyroid gland was not significantly different from control group. Dose of metribuzin 25 mg/kg/day decreased relative weight of thyroid gland in female rats. Another purpose of this study was to investigate the effects of endocrine-disruptors as like thyroid hormone in vitro. Luciferase activity was measured to detect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of metribuzin from 1 to 1,000 nM increased to 106-122% of luciferase activity.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.207-214
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• 2008

This study was designed to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects, especially thyroid function. Male and female Sprague-Dawley rats were gavaged daily with 0, 12.5, 25, 50 mg/kg alachlor in corn oil during 30 days. The effects of alachlor on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of alachlor 25, 50 mg/kg/day increased relative weight of testis and thyroid gland in exposed male rats and decreased relative weight of vagina in exposed female rats. Relative weight of thyroid gland was decreased in alachlor 25 mg/kg/day exposed female rats. Dose of alachlor 25, 50 mg/kg/day decreased plasma T4 and testosterone in female rats. Another purpose of this study was to investigate the effects of endocrine disruptors as like thyroid hormone in vitro. Luciferase activity was measured to dectect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of alachlor 1 nM-1000 nM increased 100-134% luciferase activity compared with control.

• Journal of Nutrition and Health
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• v.44 no.3
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• pp.196-202
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• 2011

Epigallocatechin gallate (EGCG), or epigallocatechin 3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin. EGCG may be therapeutic for many disorders including diabetics and some types of cancer. However it is unknown whether EGCG can induce transdifferentiation of pancreatic cells in pancreatitis. The aim of this study was to investigate the effects of EGCG on the expression of pancreatic regenerating related markers in pancreatic AR42J cells, a model of pancreatic progenitor cells. AR42J cells, differentiated with betacellulin and activin A, were cultured with/without EGCG in a time-dependent manner. Cell growth rate, levels of mRNA, and protein expression were examined with the MTT assay, quantitative PCR, and Western blots, respectively. The results showed that AR42J cell growth rates were inhibited by EGCG in a dose-dependent manner. mRNA and protein expression of amylase, insulin and neurogenin 3 (ngn 3) increased in AR42J cells treated with EGCG. Additionally, we demonstrated that the signal transduction pathway of mitogen-activated protein (MAP) kinase is active in EGCG-treated AR42J cells. ERK and JNK phosphorylation decreased in cells treated with EGCG but not p38 phosphorylation. Activation of the p38 MAP kinase pathway was confirmed by specific MAP kinase pathways inhibitors: U0126 for ERK, SP600126 for JNK, and SB203580 for p38. Activated p38 phosphorylation was inhibited by the specific p38 inhibitor SB203580 but p38 phosphorylation was inhibited with increased EGCG treatment. The ERK and JNK MAP kinase pathways were not affected by EGCG treatment. Although further studies are needed, these results suggest that EGCG affects the induction of pancreatic cell regeneration by increasing the ngn 3 protein and mRNA expression and activating the p38 MAP kinase pathway.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.188-197
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• 2003

Endocrine disrupting chemicals (EDCs) can alter hormone regulation that control reproductive system in animals. The effects of endosulfan, molinate, and alachlor that suspected to have examined disruption EDCs effect on a fish species of interest, Xiphophorus helleri (swordtail fish), were studied using vitellogenin (Vtg) and aromatase as diagnostic biomarkers. Induction of Vtg proteins was detected by RT-PCR in male fish treated with alachlor, and mixture of endosulfan and molinate in dose response manner. Also, induction of aromatase was detected by RT-PCR in male fish treated with alachlor, endosulfan, and mixture of endosulfan and molinate in sinlilar manner. In this study, swordtail fish exposed to endosulfan or molinate individually did not show any adverse effects. However, Vtg and aromatase expressions and apoptosis were detected in swordtail. fish exposed to the mixture of endosulfan and molinate. These results suggested that low concentrations of mixture of molinate and endosulfan individually do not affect swordtail fish, but may influence genital system, and induce apoptosis.

• Journal of fish pathology
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• v.26 no.3
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• pp.241-254
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• 2013

In order to establish bio-marker systems for the screening of endocrine-disrupting chemicals contaminated in various environment, Vitellogenin(Vtg) bio-marker have been developed to detect Scorpion fish's(Sebastiscus marmoratus) Vtg. Vtg has been induced by administration of estradiol into S. marmoratus, and purified by gel filtration and ion-exchange chromatography from serum of the fish. After immunization of the purified Vtg into BALB/c mouse, hybridomas secreting anti-Vtg antibodies have been produced. The size of induced Vtg in the serum was about 440 kDa by gel filtration using Sepharose CL-6B. By SDS-PAGE analysis, the main band of Vtg, however, was at 175 kDa, and several minor bands have been detected with the main band. Eight different monoclonal antibodies have been produced from established hybridomas and the antibodies did not cross-react with sera from different species of fishes tested in this study except with that of Sebastes hubbsi. These results suggested that the monoclonal antibody of S28 and S15 can used as capture and tracer antibodies for ELISA and ICG assays. The detection systems developed in this study can be used as Bio-marker assays to check endocrine disrupting activity of various chemicals as well as to detect known endocrine disrupting chemicals contaminated in environment.

• Health Policy and Management
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• v.29 no.1
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• pp.58-67
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• 2019

Background: In this study, we aimed to investigate the drinking behaviors and drinking-related problems of college students in South Korea to produce national alcohol statistics. Methods: We carefully examined the questionnaires and previous research developed in the previous research project and selected questions that reflect the special environment and culture of college students. In order to stratify a nationally representative sample of college students, the distribution of students around the country were found through the educational statistics database of the Korea Educational Development Institute. Based on this information, we conducted a survey in collaboration with Gallup (Korea) to survey and analyze the drinking behaviors of 5,024 Korean students. Results: A nationwide cross-sectional survey was conducted in 2017, for Korean college students. A total of 5,024 students were recruited and analyzed. The monthly drinking rate was 78.0% for male students and 72.9% for female students. The high-risk drinking rate was 23.3% for male students and 17.2% for female students. The most popular category for number of drinks per drinking session was 'more than 10 glasses' per drinking session for both male (44.1%) and female (32.8%). On the alcohol use disorders identification test, the greatest proportion of male students were in the high-risk drinking category (score 8 to 15) 43.8%, followed by the 'low-risk drinking' (score 0 to 7) in 43.6%, 'alcohol abuse' (score 16 to 19) 7.2%, and 'alcohol dependence' (greater than 20) 5.4% categories, respectively. For female students, the greatest proportion of female students were in the 'low-risk drinking' in 49.6%, followed by 'high-risk drinking' 37.1%, 'alcohol abuse' 8.4%, and 'alcohol dependence' 4.9% categories, respectively. Conclusion: The results of the study showed that the drinking behavior of Korean college students was excessive. Overall, it was found that the college population has a greater high-risk drinking behaviors than general adult population. Furthermore, these problem drinking behaviors were prominent among female college students. Results from the present study suggest that it is necessary to monitor the drinking behavior of college students with constant interest and to prepare policies and strategies suitable for these circumstances.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.305-310
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• 2023

This study aimed to determine the human androgen receptor (AR)-mediated endocrine disrupting potential of parabens and triclosan in food and household products using a cell-based assay in the OECD TG No.458, the 22Rv1/MMTV_GR-KO transcriptional activation assay. Four parabens (methyl-, ethyl-, propyl-, and butyl-) are determined as AR antagonists in OECD TG No.458. However, their AR antagonistic effects were not exhibited in the presence of the S9 hepatic fraction. Triclosan is also classified as an AR antagonist, and the AR antagonistic effect induced by triclosan significantly decreased in the presence of the phase I + II S9 fraction. Regarding the mechanism of AR antagonism induced by parabens and triclosan, the AR-mediated endocrine disrupting effects were exhibited through suppressing the translocation of ligand-bound AR to the nucleus via blocking of AR dimerization in the cytosol. These results indicate that the four parabens and triclosan have AR-mediated endocrine disrupting potential through an AR antagonistic effect via inhibiting AR dimerization; however, their endocrine disrupting effects deceased in the presence of hepatic metabolic enzymes.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2000.12a
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• pp.53-53
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• 2000