• Tuberculosis and Respiratory Diseases
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• 제84권3호
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• pp.237-244
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• 2021

Background: The emergence of drug-resistant tuberculosis (TB), is a major menace to cast off TB worldwide. Line probe assay (LPA; GenoType MTBDRplus ver. 2) and Xpert MTB/RIF assays are two rapid molecular TB detection/diagnostic tests. To compare the performance of LPA and Xpert MTB/RIF assay for early diagnosis of rifampicin-resistant (RR) TB in acid-fast bacillus (AFB) smear-positive and negative sputum samples. Methods: A total 576 presumptive AFB patients were selected and subjected to AFB microscopy, Xpert MTB/RIF assay and recent version of LPA (GenoType MTBDRplus assay version 2) tests directly on sputum samples. Results were compared with phenotypic culture and drug susceptibility testing (DST). DNA sequencing was performed with rpoB gene for samples with discordant rifampicin susceptibility results. Results: Among culture-positive samples, Xpert MTB/RIF assay detected Mycobacterium tuberculosis (Mtb) in 97.3% (364/374) of AFB smear-positive samples and 76.5% (13/17) among smear-negative samples, and the corresponding values for LPA test (valid results with Mtb control band) were 97.9% (366/374) and 58.8% (10/17), respectively. For detection of RR among Mtb positive molecular results, the sensitivity of Xpert MTB/RIF assay and LPA (after resolving discordant phenotypic DST results with DNA sequencing) were found to be 96% and 99%, respectively. Whereas, specificity of both test for detecting RR were found to be 99%. Conclusion: We conclude that although Xpert MTB/RIF assay is comparatively superior to LPA in detecting Mtb among AFB smear-negative pulmonary TB. However, both tests are equally efficient in early diagnosis of AFB smear-positive presumptive RR-TB patients.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.67-67
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• 2021

The genus Glycyrrhiza (Licorice) has been used as an oriental herbal medicine for a long time in Asian countries. Wongam (WG), which is Glycyrrhiza new variety, have been developed to improve limitation of licorice including low productivity, environmental restriction and insufficient components by Korea Rural Development Administration. To using WG as a herbal medicine, it is important to reveal the adverse effects in health. In this study, we evaluated the genotoxicity test of WG extract through in vitro bacterial reverse mutation (AMES) assay, in vitro chromosomal aberration assay and in vivo mouse bone marrow micronucleus assay. When compared with the control, WG extract with or without the S9 mix showed no genotoxicity in the AMES assay up to 5000 ㎍/plate and in the chromosomal aberration assay up to 1100 ㎍/ml. In micronucleus assay, no significant increase in the number of micronucleated polychromatic erythrocytes or in the mean ratio of polychromatic to total erythrocytes up to 5000 mg/kg/day for 2 days. The present study demonstrated that WG extract is safe and reliable herbal medicine since no detectable genotoxic effects at least under the conditions of this study.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권1호
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• pp.35-48
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• 1993

The in vitro predictive tests in cancer chemotherapy of cancer cell lines to anticancer drugs were determined using novel dye exclusion assay [NDEA], [3H] thymidine incorporation, and clonogenic assay [CA>. Antitumor effect of Bleomycin, Cis-platin, Vinblastine, Methotrexate to HEp-2, B16 cell lines using rapid assays was compared with [CA> in this study. In dye exclusion assay of B l6 cell line, cancer cells were sensitive to Bleomycin at all concentrations, to Vinblastine at the level of peak plasma concentration [PPC], ${\times}1/10$ [PPC](P<0.05). And Bleomycin revealed relatively good cytotoxicity than that of CDDP and vinblastine at ${\times}10$[PPC], (P<0.05). HEp-2 cells were resistive to methotrexate at the level of ${\times}100$[PPC] (P<0.05) In [3H] thymidine incorporation assay, B 16 cells were sensitive to Bleomycin, CDDP, Vinblastine at the level of [PPC], ${\times}10$ [PPC](P<0.01). Dose-dependent drugs of bleomycin, CDDP were more sensitive than Vinblastine at high concentration (P<0.05). In clonogenic assay, HEp-2 cell line was sensitive to three drugs of all concentrations except ${\times}10$ [PPC] of CDDP. B 16 cell line was sensitive to all drugs(P<0,01). In comparison of chemosensitivity tests among three assays, the results were correlated(${\gamma}=0.99$, P<0.05).

• Bulletin of the Korean Chemical Society
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• 제27권3호
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• pp.407-412
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• 2006

Bioluminescence single-site immunometric assay for methamphetamine (MA) using the native aequorin, a photoprotein, as a signal generator was developed for the first time. MA is a potent sympathomimetic amine with stimulant effects on the central nervous system. MA abuse induces hallucinations and, thus, may cause a serious social problem. The single-site immunometric MA assay was optimized and its dose-response behavior was examined. The dose-response curve shows that the detection limit is 1.1 ${\times}$ $10^{-10}$ M and a dynamic range is four orders of magnitude with 15 $\mu$g/mL BSA-MA conjugate and 1.0 ${\times}$ $10^{-8}$ M anti-MA antibody-biotin conjugate. In order to evaluate this assay, the structurally similar compounds, amphetamine, ephedrine, norephedrine, benzphetamine and N-4-(aminobutyl)methamphetamine were examined for their crossreactivity. None of these five compounds showed any cross-reactivity. Additionally, an artificial urine solution spiked with MA was analyzed by the MA assay, and the result of the analysis demonstrated the usefulness of the present assay for the determination of MA in urine.

• BMB Reports
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• 제43권7호
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• pp.468-473
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• 2010

Previously, various inhibitors of cell wall synthesis induced the drp35 gene of Staphylococcus aureus efficiently. To determine whether drp35 could be exploited in antistaphylococcal drug discovery, we cloned the promoter of drp35 ($P_d$) and developed different biological assay systems using an engineered S. aureus strain that harbors a chromosomally-integrated $P_d$ - lacZ transcriptional fusion. An agarose-based assay showed that $P_d$ is induced not only by the cell wall-affecting antibiotics but also by rifampicin and ciprofloxacin. In contrast, a liquid medium-based assay revealed the induction of $P_d$ specifically by the cell wall-affecting antibiotics. Induction of $P_d$ by sublethal concentrations of cell wall-affecting antibiotics was even assessable in a microtiter plate assay format, indicating that this assay system could be potentially used for high-throughput screening of new cell wall-inhibiting compounds.

• 대한의생명과학회지
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• 제10권3호
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• pp.263-268
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• 2004

This study was carried out to evaluate the cytotoxic effect of phenolic compound on normal NIH 3T3 fibrolasts. The colorimetric assay for phenol compound, syringic acid was performed by MTT assay or XTT assay. MTT or XTT assays are known as a very sensitive method in measuring the cytotoxic effect of chemical agents in vitro. In the present study, syringic acid on normal Nlli 3T3 fibroblasts did not show any cytotoxicity for MTT assay or XTT assay compared with control after cells were treated with various concentrations of syringic acid for 48 hours. MTT/sub 50/ and XTT/sub 50/ were 3,340.9 μM and 2,462.4 μM of syringic acid, respectively. From the above the results, it is suggested that phenolic compound of syringic acid did not have any cytotoxicity on normal NIH 3T3 fibroblasts.

• 동의신경정신과학회지
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• 제16권2호
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• pp.73-88
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• 2005

Object : This study was designed to asses the effect of Kunnuetang 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 Kunnuetang, Duchang and Daejo. Result : 1. Kunnuetang, was effective on LDH assay of hypoxia and reoxygenation. 2. Duchang and Daejo were generally effective on LDH assay of hypoxia and reoxygenation. 3. In MTT assay of hypoxia Kunnuetang was not effective. Duchung and Daejo were not generally effective on MTT assay, but in certain condition Herbs were effective. 4. In MTT assay of reoxygenation Kunnuetang and Daejo were not effective. But Duchung was effective in certain condition. Conclusion : The results suggest that Kunnuetang, Duchang and Daejo may have protective effect on vascular dementia and ad patient.

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.7-13
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• 1999

The mouse lymphoma thymidine kinase (tk+/-) gene assay (MOLY) using L5178Y tk+/- mouse lymphoma cell line is one of the mammalian forward mutation assays. It is well known that MOLY has many advantages and more sensitive than the other mammalian forward mutation assays such as x-linked hyposanthine phosphoribosyltransferase (hprt) gene assay. The target gene of MOLY is a heterozygous tk+/- gene located in 11 chromosome of L5178Y tk+/- cell, so it is able to detect the wide range of genetic changes like point mutation, deletion, rearrangement, and mitotic recombination within tk gene or deletion of entire chromosome 11. MOLY has relatively short expression time (2-3 days) compared to 1 week of hprt gene assay. MOLY can also induce relatively high mutant frequency so a large number of events can be recorded. The bimodal distribution of colony size which may indicate gene mutation and chromosome breakage potential of chemicals according to mutation scale such as large normal-growing mutants and small slow-growing mutants can be observed in this assay. The statistical analysis of data can be performed using the MUTANT program developed by York Electronic Research in association with Hazelton as recommended by the UKEMS (United Kingdom Environmental Mutagen Society) guidelines. This report reviewed MOLY using the microtiter cloning technique (microwell assay).

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.106-113
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• 2006

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were classified in the category of "suspected" endocrine disruptors. The purpose of our study was to screen and elucidate the endocrine disrupting activity of seven phthalate analogues. E-screen assay was performed in MCF-7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) showed high estrogenic activity. Their relative proliferation efficiencies (RPE) were 109 and 106%, respectively. In vitro estrogen receptor (ER) binding assay, BBP, di-n-octyl phthalate (DOP) and dinonyl phthalate (DNP) showed weak relative binding affinity (RBA: 0.02%) compared to $17{\beta}-estradiol\;(E2)$ (RBA: 100%). In uterotrophic assay, E2 produced a significant increase, whereas four tested phthalate analogues had potential estrogenic effects in vitro did not increased in uterus weight in immature rats. From these results, we demonstrated that phthalate analogues exhibit weak estrogenic activity in vitro assays at high concentrations. Although phthalates induced an increase in MCF-7 cell proliferation by an estrogenic effect, they could not induce a uterus weight increase in vivo. From these, we may suggest that these phthalate analogues are easily metabolized to inactive forms in vivo. Further investigation in other in vitro and in vivo experimental systems might be required.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.569-573
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• 2010

A quantitative detection method for Salmonella in seafood was developed using a SYBR Green-based real-time PCR assay. The assay was developed using pure Salmonella DNA at different dilution levels [i.e., 1,000 to 2 genome equivalents (GE)]. The sensitivity of the real-time assay for Salmonella in seeded seafood samples was determined, and the minimum detection level was 20 CFU/g, whereas a detection level of 2 CFU/ml was obtained for pure culture in water with an efficiency of ${\geq}85%$. The real-time assay was evaluated in repeated experiments with seeded seafood samples and the regression coefficient ($R^2$) values were calculated. The performance of the real-time assay was further assessed with naturally contaminated seafood samples, where 4 out of 9 seafood samples tested positive for Salmonella and harbored cells <100 GE/g, which were not detected by direct plating on Salmonella Chromagar media. Thus, the method developed here will be useful for the rapid quantification of Salmonella in seafood, as the assay can be completed within 2-3 h. In addition, with the ability to detect a low number of Salmonella cells in seafood, this proposed method can be used to generate quantitative data on Salmonella in seafood, facilitating the implementation of control measures for Salmonella contamination in seafood at harvest and post-harvest levels.