• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.293-299
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• 2000

Many methods have been developed for screening chemicals with hormonal activity. Using recombinant yeasts expressing either human estrogen receptor [Saccharomyces cerevisiae ER + LYS 8127 (YER)] or androgen receptor [S. cerevisiae AR + 8320 (YAR)], we evaluated the hormonal activities of several chemicals by induction of ${\beta}-galactosidase$ activity. The chemicals were $17{\beta}-estradiol$ (E2), testosterone (T), ${\rho}-nonylphenol$ (NP), bisphenol A (BPA), genistein (GEN), 2-bromopropane (2-BP), dibutyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and butylparaben (BP). To assess the estrogenicity of NP, the result of the in vitro recombinant yeast assay was compared with an E-screen assay using MCF-7 human breast cancer cells and an uterotrophid assay using ovariectomized mice. In the YER yeast cells, E2, NP, BPA, GEN, and BP exhibited estrogenicity in a doseresponse manner, while TCDD did not. All the chemicals tested, except T, did not show androgenicity in the YAR yeast cell. The sensitivity of the yeast (YER) assay system to the estrogenic effect of NP was similar to that of the E-screen assay. NP was also estrogenic in the uterotrophic assay. However, in terms of convenience and costs, the yeast assay was superior to the E-screen assay or uterotrophic assay. These results suggest that the recombinant yeast assay can be used as a rapid tool for detecting chemicals with hormonal activities.

• Annals of Laboratory Medicine
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• v.39 no.1
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• pp.50-57
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• 2019

Background: The Automated Fluorescent Immunoassay System (AFIAS) rotavirus assay (Boditech Med Inc., Chuncheon, Korea) is a new rapid antigen test for rotavirus detection. We evaluated the performance of this assay for detecting rotaviruses and their specific genotypes in clinical stool samples. Methods: AFIAS rotavirus assay was performed in 103 rotavirus-positive and 103 rotavirus-negative stool samples (confirmed by both PCR and ELISA), and its results were compared with those of PCR, ELISA, and immunochromatographic assay (ICA). We evaluated diagnostic sensitivity/specificity, the detectability of rotavirus subtypes, lower limit of detection (LLOD), reproducibility, cross-reactivity, and interference of AFIAS rotavirus assay. Results: Based on PCR and ELISA results, diagnostic sensitivity and specificity of the AFIAS rotavirus assay were both 99.0%. LLOD results showed that the AFIAS assay had sensitivity similar to or greater than ICA and ELISA. High reproducibility was confirmed, and no cross-reactivity or interference was detected. This assay could detect genotypes G1P[8], G2P[4], G3P[8], G4P[6], G4P[8], G8P[4], G8P[8], G9P[4], and G9P[8]. Conclusions: The AFIAS rotavirus assay showed high reproducibility, sensitivity, and specificity as well as excellent agreement with ELISA, PCR, and ICA. It detected the most common as well as unusual genotypes of rotavirus prevalent in Korea. It could be a useful onsite assay for rapid, convenient, and cost-effective detection of rotavirus infection.

• Toxicological Research
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• v.16 no.2
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• pp.141-146
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• 2000

Phthalate esters are used extensively as a plasticizer in the manufacture of plastic products such as PVC bags and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However. only a Jew studies have been conducted for estrogenic activity of phthalate esters. In this study estrogenic activities of seven phthalate esters. butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPP), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), were examined in vitro using E-screen assay and competitive binding assay. From the E-screen assay, BBP. DEHP. DBP and DEP showed weak estrogenic activity at the concentration of 5 $\mu\textrm{M}$. The relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 50~70% and 0.01%. respectively, when compared with 500 pM of 17$\beta$-estradiol (E2). In competitive binding assay with the rat uterine estrogen receptor (ER), BBP and DEP showed weak binding potency ［(l/$10^4$~1/$10^5$ of E2］ while DEHP and DBP scarcely bound to ER. These results suggest that some phthalate esters have weak estrogenic activities in vitro.

• Environmental Mutagens and Carcinogens
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• v.21 no.1
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• pp.34-43
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• 2001

Di-2-ethylhexyl phthalate (DEHP) is the most commonly used phthalate ester in polyvinyl chloride formulations including food packing and storage of human blood. DEHP is a well known as non-genotoxic carcinogen and endocrine disrupting chemical (EDC). DEHP have shown all negative results in ICH-guildeline recommended standard genotoxicity test battery. In this study, to assess the clastogenic and DNA damaging effect in human-derived tissue specific cells, DEHP was treated in human derived MCE-7 cells, HepG2 cells, LNCap cells, BeWo cells, MCE-10A cells, and female peripheral blood cells using micronucleus assay and in human breast carcinoma MCF-7 cells up to $1.28$\times$10^{-2}$ M using Comet assay. The in vitro micronucleus assay is a mutagenicity test system for the detection of chemicals which induce the formation of small membrane bound DNA fragment i.e. micronuclei in the cytoplasm of interphase cells, originated from clastogenic and/or aneugenic mechanism. The single cell gel electrophoresis assay (Comet assay) is used to detect DNA strand-breaks and alkaline labile site. In our results, DEHP increased significantly and/or dose-depentently and time-dependently micronucleus frequency at the 6 and 24 hr without metabolic activation system only in MCE-7 cells. DEHP treated with 2 hrs in MCF-7 cells using Comet assay induced DNA damage dose-depentantly.

• Journal of Oriental Neuropsychiatry
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• v.17 no.2
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• pp.37-59
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• 2006

Objective : This study was designed to asses the effect of Hwangryunhaedoktang and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation. Mouse neuroblastoma 2a (N2a) cells were treated by Hwangryunhaedoktang and herbs. Result : 1. Hwangryunhaedoktang was effective on LDH assay of hypoxia and reoxygenation. 2. All of herbs were generally effective on LDH assay of hypoxia and reoxygenation. In LDH assay of hypoxia, the effects of herbs depended on concentration. In MTT assay of hypoxia, Coptidis Rhizoma and Gardeniae Fructus were effective. In MTT assay of reoxygenation most of herbs were not effective. But Phellodendri Cortex was effective in high concentration. Conclusion : The results imply that Hwangryunhaedoktang and all herbs of it nay have protective effect on dementia and aging.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.278-285
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• 1998

The microdilution assay recommended by NCCLS (National Committee for Clinical Laboratory Standards) is one of the standardized methods of antibiotic susceptibility test. This method has been widely used clinically to obtain MIC values of antibiotics on pathogenic microorganisms. It is more convenient, rapid and simple to test many samples than other test methods such as agar diffusion assay and broth macrodilution assay. The screening of antimicrobial agents from microbial extracts is too laborious in its process. Therefore, a number of screening methods having more simple procedure have been developed. In our laboratory, we applied microdilution assay for screening the antimicrobial agents. This assay showed dose-response results and was more sensitive than disc diffusion assay in our system. We tested 200 samples of microbial extracts originated from 100 microbial strains and selected several samples as potential candidates. In this report, we show that the microdilution assay is more convenient method in screeing of antibiotic susceptibility than those previously reported.

• YAKHAK HOEJI
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• v.46 no.3
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• pp.208-212
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• 2002

Dehydroevodiamine HCl (DHED), which is a component separated from Evodia rutaecarpa Bentham, has novel anticholinesterase and antiamnesic activities in the scopolamine-induced amnesia model. Several studies suggest that DHED might be an effective drug for the Alzheimer's disease and the vascular type of dementia. In order to evaluate the mutagenic potential of DHED, Salmonella typhimurium reversion assay, chromosomal aberration test on Chinese hamster lung cells, in vivo micronucleus assay using mouse bone marrow cells, and comet assay were performed. DHED did not increase the number of revertant in the reverse mutation test using Salmonella typhimurium TA1535, TA1537, TA98, TA100. DHED HCl, at concentration of 5 and 10 $\mu\textrm{g}$/mι, increased the number of chromosome aberrated Chinese hamster lung cells with 5 and 10％, respectively. In mouse micronucleus test, no significant increase in the occurrence of micronucleated polychromatic erythrocyte was observed in ICR mice orally administered with DHED. DHED was tested for ability to induce genotoxic effect in L5178Y cells (mouse lymphoma cells) using the single cell gel electrophoresis assay (comet assay). In comet assay, tail moment did not increase in L5178Y cells treated with 10, 100, 300 $\mu$M DHED.

• Korean Journal of Clinical Laboratory Science
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• v.42 no.1
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• pp.38-45
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• 2010

The aim of this study was to assess the Clinical Usefulness of Helicobacter pylori Stool Antigen (HpSA) immunochromatographic assay for the diagnosis of H. pylori infection. In this study, we had compared HpSA-immunochromatographic assay with CLO test and UBT test. From a total of 140 patients (M:F=88:52) with upper endoscopy, biopsy specimens were obtained for CLO test. Stool specimens was collected from all patients and tested using a HpSA-immunochromatic assay. H. pylori infection status was defined as infected if the results of both CLO test and UBT test were positive. CLO test and UBT test findings showed that 92 patients were H. pylori positive and 48 patients were H. pylori negative. According to this definition, the sensitivity, specificity, and positive or negative predictive value (PPV, NPV) of HpSA-immunochromatographic assay were 97.8%, 100%, 100%, and 96%, respectively. Cross reactivity test of HpSA-immunochromatographic assay were performed with 10 enteric bacteria strains in fecal habitat, and there were no false positive reaction. We evaluated the usefulness of HpSA assay for eradication therapy with 10 of 92 H. pylori positive patients, positive results of them at pre-eradication therapy were converted to negative at post-eradication. The HpSA-immunochromatographic assay is a highly sensitive and specific non-invasive diagnostic method for detection of H. pylori infection, a useful diagnostic method for H. pylori in post eradication stage.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.964-969
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• 2000

Di-(2-ethylhexyl) adipate(DEHA) has been used extensively as a plasticizer in the manufacture of plastic products such as PVC films. Though, phthalate esters plasticizers have been known to induce endocrine system-mediated responses, few studies have been conducted for the screening of estrogenic activity of DEHA, an adipate plasticizer. This study was initiated to evaluate the estrogenic activity of DEHA by in vitro E-screen assay and in vivo uterotrophic assay. MCF-7 human breast cancer cells were treated with $DEHA(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, for 144 hr, and cell proliferation was determined by sulforhodamine B(SRB) assay. DEHA dissolved in corn oil was administered subcutaneously to ovariectomized(OVX) female Sprague-Dawley rats at dosage levels of 0, 2, 20 and 200 mg/kg/day for three consecutive days. Rats were sacrificed 24 hr after final treatment and vagina and uterus(wet and blotted) weights were obtained. E-screen assayed DEHA did not generate cell proliferation at treated concentrations$(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, whereas 17 ${\beta}-estradiol$(E2), the positive control, induced cell proliferation at low concentrations$(5{\times}10^{-14}{\sim}5{\times}10^{-9}\;M)$. In the uterotrophic assay, DEHA did not change vagina and uterus(wet and blotted) weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that DEHA did not exhibit the estrogenic activity as determined by in vitro E-screen assay and in vivo uterotrophic assay.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.388-394
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• 2017

Although several analytical methods for measuring total antioxidant capacity (TAC) have been applied to biological samples, there were often dissimilar results due to the different principles of methods applied. Thus, this study aimed to validate four conventional analytical methods for measuring plasma TAC, including the ABTS assay, DPPH assay, FRAP assay, and ORAC assay, by comparing with urinary 8-isoprostane concentration. In addition, TAC results were compared with antioxidant enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase in erythrocyte, and catalase in plasma. Plasma TAC measure by ABTS assay was strongly correlated with the result by FRAP assay. Plasma TAC by FRAP and ORAC assays were negatively correlated with erythrocyte SOD activity. The agreement among the four TAC assay methods and 8-isoprostane was determined using 95% prediction limits of linear regression, expressed as the mean of 8-isoprostane ${\pm}95%$ prediction limits. The ABTS method better agreed with 8-isoprostane than the other methods, demonstrating narrow prediction of limits. Furthermore, only plasma TAC determined by the ABTS assay was inversely correlated with urinary 8-isoprostane (r = -0.35, p < 0.05). In summary, the ABTS assay would be an appropriate method to measure overall plasma antioxidant capacity and predict the body's antioxidant status.