• YAKHAK HOEJI
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• v.44 no.5
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• pp.416-423
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• 2000

There is a growing concern that a wide variety of chemicals released into the environment can disrupt the endocrine system of fish, wildlife and humans. Endocrine disrupting chemicals (EDCs) include pesticides such as DDT lindane and atrazine, the food packaging chemicals, phthalates and bisphenol A, alkylphenol ethoxylate detergents and the chemical industry by-products, dioxins. Xenoestrogens in the environment have been argued about health risk, because of estrogen mimetic chemicals are exposed only small amounts to human. A number of in vivo and in vitro assays are now in use to assess the activity of xenoestrogens in the environment. A human breast cancer cell line (MCF-7) was used to develop in vitro screening assay for the detection of xenoestrogenic environmental pollutants. The E-SCREEN (MCF7-BUS) assay is proposed as a reliable, easy and rapid-to-perform method. To optimize and validate this method before it can be used routinely, several phenol compounds and pesticides suspected to be estrogenic were tested using I-SCREEN assay. The results showed that this method is a valuable tool for screening potential estrogen-mimicking environmental pollutants and quantitative determination of estrogeniciy.

• 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.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.87-91
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• 1990

Development of a solid-phase chemiluminescence immunoassay for the detection of progesterone in serum extract was described. The chemiluminescence immunoassay was establised utilizing anti-progesterone monoclonal antibody that coated on polystyrene tubes and progesterone-ABEI conjugate as tracer. The light yield generated from antibody bound conjugate was counted on clinilumat luminometer by oxidation with microperoxidase and peroxide. The chemiluminescence immunoassay was high specific and accurate and detects as little as 3.9ng/ml of progesterone. The intra-assay CV ranged from 6% to 11.5% and inter-assay CV ranged from 13.6% to 18.7%. This assay system was good correlated with conventional kit radioimmunoassay system (r=0.98).

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.183-183
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• 1994

HIV-1 protcase 를 이용한 in vitro assay system을 개발하기 위하여HIV-1 protease유전자를 Ecoli 발현 벡터를 이용하여 발현시켰다. 가능성있는 Protease유전자의 생간 및 분래를 용이하게 하기위하여 maltose binding protein 의 fusion protein을 이용하였으며 protease 의 autoprocessing을 maltose binding protein 의 polyclonal 항체로 확인하였다, 발현된 protease는 일련의 chromatography 방법 (DEAE, SE cellulose, Superose 12, Mono S) 으로 순수하게 분리되었다. 정제된 protease 는 SDS-PAGE분석으로 단일밴드를 보여주었고, 합성된 undecapeptide를 기질로 하였을때 Km 이 9.8$\mu$M 이었다. 효소 assay 를 위해 기질이 protease 에 의해 절단된 생성물을 HPLC를 사용하여 분석하였다. Protease의 억제제 탐색을 위해 유기합성한 몇개의 기질유사체와 HIV-1 증식을 억제하는 것으로 알려진 천연물의 억제정도를 조사하여 보았다. 이들 test 에 사용한 물질들은 높은 농도에서 protease 의 활성을 저해하는 것으로 보아 좋은 억제제는 아닌것으로 시료되나 본 연구를 통하여 확립된 in vitro assay system 은 추후에도 억제제 탐색을 위하여 계속 활용될 수 있을 것이다.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.133-137
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• 1993

A high-performance liquid chromatographic assay using ion-pair reverse-phase system was developed for the separation of acebutolol and acebutolol acetyl metabolite in plasma. A ion-pair reversephase system consisting of an ODS-bonded silica column and a mixture of 20% $CH_3CN$, 0.1% $H_3PO_4$, 0.035 M heptanesulfonic acid and 0.005 M tetrabutylammonium hydrogen sulfate as the mobile phase were used. Triamterene was employed as an internal standard. Based on 0.2 ml of plasma, the detection limits were 10.4 ng/ml for acebutolol and 10.3 ng/ml of acebutolol acetyl metabolite at the signal-to-noise ratio of 3:1.

• Analytical Science and Technology
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• v.30 no.3
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• pp.154-158
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• 2017

The Korean Pharmacopoeia (KP XI), British Pharmacopoeia (BP 2013) and Japanese Pharmacopoeia contain monographs for the quality control of raw fusidate sodium and its formulations using high performance liquid chromatography (HPLC). However, the assay method for the determination of fusidate sodium in commercial tablets is titration which is less specific than HPLC. In this study, we present an alternative HPLC method for quantitation of fusidate sodium in tablets. Method validation was performed to determine linearity, precision, accuracy, system suitability, and robustness. The linearity of calibration curves in the desired concentration range was high ($r^2=0.9999$), while the RSDs for intra- and inter-day precision were 0.25-0.37 % and 0.11-0.60 %, respectively. Accuracies ranged from 99.46-100.85 %. Since the system suitability, intermediate-precision and robustness of the assay were satisfactory, this method will be a valuable addition to the Korean Pharmacopoeia (KP XI).

• Journal of Biomedical Engineering Research
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• v.35 no.1
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• pp.1-7
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• 2014

Among semi-quantitative or fully quantitative lateral flow assay readers, an image sensor-based instrument has been widely used because of its simple setup, cheap sensor price, and compact equipment size. For all previous approaches, monochrome CCD or CMOS cameras were used for lateral flow assay imaging in which the overall intensities of all colors were taken into consideration to estimate the analyte content, although the analyte related color information is only limited to a narrow wavelength range. In the present work, we introduced a color CCD camera as a sensor and a color decomposition method to improve the sensitivity of the quantitative biosensor system which utilizes the lateral flow assay successfully. The proposed setup and image processing method were applied to achieve the quantification of imitatively dispensed particles on the surface of a porous membrane first, and the measurement result was then compared with that using a monochrome CCD. The compensation method was proposed in different illumination conditions. Eventually, the color decomposition method was introduced to the commercially available lateral flow immunochromatographic assay for the diagnosis of myocardial infarction. The measurement sensitivity utilizing the color image sensor is significantly improved since the slopes of the linear curve fit are enhanced from 0.0026 to 0.0040 and from 0.0802 to 0.1141 for myoglobin and creatine kinase (CK)-MB detection, respectively.

• YAKHAK HOEJI
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• v.49 no.5
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• pp.410-415
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• 2005

To investigate biological activity of noni extracts treated with HCl and trypsin, we measured the antioxidant activity through vitro assay and cellular system. Both water and lipid soluble fraction of noni extracts dose-dependently scav­enged DPPH radical. Superoxide scavenging activity of lipid soluble fraction after treating HCl and trypsin was significantly more potent than those of other fractions in NBT/xanthine oxidase assay, which suggests that antioxidant activity of noni extracts was increased by the treatment with HCl and trypsin. In antioxidant assay using RBL 2H3 cells, water soluble frac­tion of noni extracts had little effect on silica-induced reactive oxygen species generation, whereas lipid soluble fraction inhibited in a dose dependent manner. In non-treated noni extracts, effect of water soluble fraction on silica/$CuSO_4$-induced lipid peroxidation was more potent than that of lipid soluble fraction. However, the effects of noni extracts were reversed in noni extracts treated with HCl and trypsin. These data suggest that water soluble substances may be converted into lipid soluble substances by the treatment with HCl and trypsin. From the above results, it is suggested that lipid soluble fraction of noni extracts contain antioxidant used in vitro assay and RBL 2H3 cellular system. Such an effect of noni extracts may be increased by the treatment with HCl and trypsin.

• Preventive Nutrition and Food Science
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• v.4 no.1
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• pp.33-37
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• 1999

The antimutagenic effects of buchu kimchi and Chinese cabbage kimchi and theri cytotoxic effects against human cancer cell line were investigated in the Salmonella typhimurium system and MTT assay, respectively. Leek and Chinese cabbage were aslo evaluated in the same system. Buchu kimchi was fermented at 15 $^{\circ}C$ for 4 days . Buchu kimchi samples showed somewhat higher antimutagenic effects against aflatoxin B1(AFB1) than CHinese cabbage kimchi in Salmonella typhimurium TA100 strain. There was no difference onthe antimutagenic activity according to the length of fermentation . Leek exerted stronger antimutagenicity against AFB1 than Chinese cabbage in the Ames assay. In MTT assay, 6-day fermented buchu kimchin revealed the highest cytotoxicity against AGS human gastric adenocarcinoma cells in which 62% and 82% of the inhibition were observed wiht the addition of 100ug, 400ug/well, respectively. Buchu kimchi samples caused 60~70% inhibition on the proliferation of HT-29 at 400ug/well. Leek exhibited higher antiproliferative effect against both AGS cells and HT-29 cells than Chinese cabbage in MTT assay. From these results, it is considered that buchu kimchi has stronger antimutagenic and in vitro anticancer effects than Chinese cabbage kimchi and the high inhibition rate of buchu kimchi probably results from leek, the major ingredient of buchu kimchi .

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.213-225
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• 2016

To reduce attrition in drug development, it is crucial to consider the development and implementation of translational phenotypic assays as well as decipher diverse molecular mechanisms of action for new molecular entities. High-throughput fluorescence and confocal microscopes with advanced analysis software have simplified the simultaneous identification and quantification of various cellular processes through what is now referred to as high-content screening (HCS). HCS permits automated identification of modifiers of accessible and biologically relevant targets and can thus be used to detect gene interactions or identify toxic pathways of drug candidates to improve drug discovery and development processes. In this review, we summarize several HCS-compatible, biochemical, and molecular biology-driven assays, including immunohistochemistry, RNAi, reporter gene assay, CRISPR-Cas9 system, and protein-protein interactions to assess a variety of cellular processes, including proliferation, morphological changes, protein expression, localization, post-translational modifications, and protein-protein interactions. These cell-based assay methods can be applied to not only 2D cell culture but also 3D cell culture systems in a high-throughput manner.