• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.19-28
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• 1999

To investigate the physiological and biochemical differences between susceptible and tolerant species of Echinochloa species to the foliar applied cyhalofop-butyl and pyribenzoxim herbicides, herbicidal response, the rate of absorption, translocation and metabolism were studied. Among 148 individuals of Echinochloa species collected from 41 sampling sites in Korea which were classified into 7 geographical regions, based on morphological characteristics of plant and seed type, 46 lines were used for further studies. From them, E. crus-galli var. praticola collected from Hwanggan and E. crus-galli var. crus-galli collected from Namyangju were selected as the most susceptible species to cyhalofop-butyl and pyribenzoxim, respectively. Meanwhile, E. oryzicola(from Cheju) and E. crus-galli var. crus-galli(from Asan) were selected as tolerant species to cyhalofop-butyl and pyribenzoxim, respectively. Application of radio-labelled herbicides on the 1st leaf to both susceptible and tolerant Echinochloa species exhibited that the applied $^{14}C$-Cyhalofop-butyl and $^{14}C$-pyribenzoxim were more easily absorbed and translocated into stem tissues than root. Absorption of $^{14}C$-Cyhalofop-butyl increased rapidly at 1 h after application and reached the maximum at 12 h after application. However, the absorption rate of $^{14}C$-pyribenzoxim was not changed. Two metabolites from cyhalofop-butyl-treated plants and one metabolite from pyribenzoxim-treated plants were separated by TLC. The amount of metabolite 1 in cyhalofop-butyl-treated tolerant species was significantly higher than that in the susceptible one, suggesting differences in detoxification ability between susceptible and tolerant species.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.976-986
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• 2018

Knowledge about the gut bacterial communities associated with insects is essential to understand their roles in the physiology of the host. In the present study, the gut bacterial communities of a laboratory-reared insecticide-susceptible (IS), and a field-collected insecticide-resistant (IR) population of a major rice pest, the brown planthopper Nilaparvata lugens, were evaluated. The deep-sequencing analysis of the V3 hypervariable region of the 16S rRNA gene was performed using Illumina and the sequence data were processed using QIIME. The toxicological bioassays showed that compared with the IS population, IR population exhibited 7.9-, 6.7-, 14.8-, and 18.7-fold resistance to acephate, imidacloprid, thiamethoxam, and buprofezin, respectively. The analysis of the alpha diversity indicated a higher bacterial diversity and richness associated with the IR population. The dominant phylum in the IS population was Proteobacteria (99.86%), whereas the IR population consisted of Firmicutes (46.06%), followed by Bacteroidetes (30.8%) and Proteobacteria (15.49%). Morganella, Weissella, and Enterococcus were among the genera shared between the two populations and might form the core bacteria associated with N. lugens. The taxonomic-to-phenotypic mapping revealed the presence of ammonia oxidizers, nitrogen fixers, sulfur oxidizers and reducers, xylan degraders, and aromatic hydrocarbon degraders in the metagenome of N. lugens. Interestingly, the IR population was found to be enriched with bacteria involved in detoxification functions. The results obtained in this study provide a basis for future studies elucidating the roles of the gut bacteria in the insecticide resistance-associated symbiotic relationship and on the design of novel strategies for the management of N. lugens.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.7-12
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• 1994

This study was designed to investigate the effects of dietary iron supplementationon ${\delta}-aminolevulinic$ acid dehydratase (DALAD) activity and liver damage of the lead(Pb)-administered rats. The iron (Fe) supplement levels were 100 ppm(Fe100) and 500ppm(Fe500) and the Pb-exposed rats were given 2, 000ppm-Pb in drinking water, while control rats were given neigher iron nor lead. Hematocrit was lower in the Pb, Fe100 -Pb, Fe500-Pb group than in the control, but was not affected by the Pb adminstration when the rats fed the Fe supplementation diet. DALAD activity were reduced by Pb added but, were higher in the Fe500-Pb group than in the Fe100 -Pb group. No significant difference was found in serum Pb content due to Pb administration and Fe supplementation. The liver Pb contentwas higher in the Fe supplementation group than in the Pb-group. Level of serum FE was lower in the Pb added groups than in the control group. Liver Fe contents were increased with Pb administration and higher in the Fe supplement groups than in the Pb-group. Levels of serum and liver copper was decreased with the Fe supplementation. Aminotransferase activity of serum and liver were increased in the Pb group.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.1
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• pp.27-32
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• 2009

Human hair is an excretory system for trace metals and thus metal content in human hair can reflect the body status. The investigation of trace elements in human hair has been correlated with the diagnosis of various diseases as well as the monitoring of deficiency statues in nutrition. Many chronic diseases may be related to mineral status, some may be related to toxic mineral. Hair samples were collected from 120 inhabitants of the city of Seoul, Korea. In this study the concentrations of 10 elements (Hg, Pb, Cd, Al, As, U, Bi, Sb, Ba, Be) in hair were determined by inductively coupled plasma mass spectroscopy (ICP-MS). The conclusions showed that people in Seoul, Korea were affected by some kinds of toxic minerals. The Hg concentrations of male are higher than those of female and reference range. The mean concentration of Sb was higher in the female than male and reference range. In age distribution, the mean concentration of Hg was in 40's are higher than 20's and 30's and reference range. The concentrations of Al were the highest in the 20's. After analyzing, we concluded that a compounded treatment should be conducted, which considers the variety of factors related to detoxification.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.413-419
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• 2016

Ryanodine receptors (RyRs) regulate the contractions of insect muscles by altering intracellular $Ca^{2+}$ concentration and are the targets of chlorantraniliprole. Recently, a chlorantraniliprole-resistant strain was reported in the diamondback moth Plutella xylostella by obtaining point mutations on the RyRs. In the present study, we established two resistant strains from Drosophila melanogaster, which were treated with low or high concentrations of chlorantraniliprole, and their resistance levels were determined on the basis of contact and ingestion toxicities. Compared with the control strain, the two resistant strains did not show any significant differences in contact toxicity. However, they showed significantly increased resistance ratios in ingestion toxicity than that by the control strain. The low and high concentration resistant strains exhibited 2.1- and 8.1-fold increased resistance ratios, respectively, compared with that by the control strain. Moreover, we found that the resistant strains had altered expression levels of RyRs and more enhanced Acetylcholinesterase and Glutathione-S-transferase activities than that by the non-selected strain. These results suggested that the resistance development of chlorantraniliprole in the two strains might be mediated by the activation of detoxification pathways in D. melanogaster.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2002.05a
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• pp.36-42
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• 2002

Diesel exhaust (DE) has been recognized as a noxious mutagen and/or carcinogen, because its components can form DNA adducts. Mechanisms governing the susceptibility to DE and the efficiency of such DNA adduct formation require clarification. The transcription factor Nrf2 is essential for inducible and/or constitutive expression of a group of detoxification and antioxidant enzymes, and we hypothesized that the nrf2 gene knockout mouse might serve as an excellent model system for analyzing DE toxicity. To address this hypothesis, lungs from nrf2(-/-) and nrf2(+/-) mice were examined for the production of xenobiotic-DNA adducts after exposure to DE (3 $mg/m^{3}$ suspended particulate matter) for 4 weeks. Whereas the relative adduct levels (RAL) were significantly increased in the lungs of both nrf2(+/-) and nrf2(-/-) mice upon exposure to DE, the increase of RAL in the lungs from nrf2(-/-) mice exposed to DE were approximately 2.3-fold higher than that of nrf2(+/-) mite exposed to DE. In contrail, cytochrome P4501Al mRNA levels in the nrf2(-/-)mouse lungs were similar to those in the nrf2(+/-) mouse lungs even after exposure to DE, suggesting that suppressed activity of phase II drug-metabolizing enzymes is important in giving ise to the increased level of DNA adducts in the Nrf2-null mutant mouse subjected to DE. Importantly, severe hyperplasia and accumulation of the oxidative DNA adduct 8-hydroxydeoxyguanosine were observed in the bronchial epidermis of nrf(-/-) mite following DE exposure. These results demonstrate the increased susceptibility of the nrf2 germ line mutant mouse to DE exposure and indicate the nrf2 gene knockout mouse nay represent a valuable model for the assessment of respiratory DE toxicity.

• Resources Recycling
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• v.24 no.6
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• pp.69-77
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• 2015

Heap bioleaching for detoxification of mine tailings is a promising technology; however, long-term studies that aim to understand the potential of this process are scarce. Therefore, this study assesses the feasibility of column bioleaching as an alternative technology for treatment of mine tailings with high concentrations of arsenic during a long-term experiment (436 days). To accomplish this objective, we designed a 350-mm plastic column that was packed with 750 g of mine tailings and inoculated with an acidophilic bacterial culture composed of A. thiooxidans and A. ferrooxidans. Redox potential, pH, ferric ion generation, and arsenic concentration of the off-solution were continuously monitored to determine the efficiency of the technology. After 436 days, we obtained up to 70% arsenic removal. However, several drops in removal rates were observed during the process; this was attributed to the harmful effect of arsenic on the bacteria consortium. We expect that this article will serve as a technical note for further studies on heap bioleaching of mine tailings.

• KSBB Journal
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• v.24 no.4
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• pp.397-402
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• 2009

The Portulaca oleracea (P. oleracea) is a popular herbal medicine in East Asia that was known to possess detoxification, antifebrile and antifungal effects. In the present study, we examined the biological activities of ethanol extracts of P. oleracea under various conditions with NIH3T3, B16F10, and MCF-7 cell line model systems. Extracts of P. oleracea (0.5 mg/ml) showed inhibition of expression of tyrosinase, but does not suppress either of TYRP-1 or DCT expression on B16F10 cells. Extracts of P. oleracea (2 mg/ml) showed anti-inflammatory effects on TNF-$\alpha$-stimulated NIH3T3/$NF{\kappa}B$-Luc cells and increase of the synthesis of collagen on NIH3T3 (wild type) cells. These results suggest that extracts of P. oleracea could be used as a functional biomaterial in developing a skin whitening agent and having the anti-inflammatory, anti-wrinkle, and anti-aging activities.

• Korean journal of applied entomology
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• v.36 no.2
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• pp.172-178
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• 1997

There was a great variation in insecticide susceptibilities among field and laboratory populations of the beet armyworm, Spodoptera exigua (Hiibner). Unselected laboratory population, which had been reared for 6-7 generations in our laboratory without exposure to insecticides, was more susceptible than its parental field population in all tested insecticides. Two selected laboratory populations with parathion or deltamethrin showed much higher insecticide tolerance than did the unselected laboratory population in their own selection insecticide. The variation of the insecticide susceptibilities was highly correlated with esterase and acetylcholinesterase activities. Field and the selected laboratory populations had lower acetylcholinesterase activities and higher esterase activities than did the unselected laboratory population. Acetylcholinesterase of the field and the selected laboratory populations had higher Km values than did that of the unselected. In a population, Km values were varied among different developmental stages; acetylcholinesterase of the fifth instar larvae had the highest Km value among those of the other larval stages. Twenty one esterase bands were separated on 6.5% nondenaturing polyacrylamide gel from the whole body extracts of the fifth instar larvae. E2, E7, E8, Ell, El6, and El7 esterase bands were developed more frequently in the insecticides-selected populations than in the unselected population. These results suggest that the variation of insecticide susceptibilities of the beet armyworm includes both biochemical mechanisms: target site insensitivity and enhanced activity of detoxification enzyme.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1235-1242
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• 2006

Sulforaphane, an isothiocyanate derived from hydrolysis of glucoraphanin in broccoli and other cruciferous vegetables, was shown to induce phase II detoxification enzymes and inhibit chemically induced mammary tumors in rodents. Recently, sulforaphane is known to induce cell cycle arrest and apoptosis in human canter cells, however its molecular mechanisms are poorly understood. In tile present study, we demonstrated that sulforaphane acted to inhibit proliferation and induce morphological changes of human hepatocarcinoma HepG2 cells. Treatment of HepG2 cells with $10{\mu}M\;or\;15{\mu}M$ sulforaphane resulted in significant G2/M cell cycle arrest as determined by DNA flow cytometry. Moreover, $20{\mu}M$ sulforaphane significantly induced the population of sub-G1 cells suggesting that sulforaphane induced apoptosis. This anti-proliferative effect of sulforaphane was accompanied by a marked inhibition of ryclin A, cyclin 31 and Cdc2 protein. However, the levels of tumor suppressor p53 and Cdk inhibitor p21 mRNA and protein expression were significantly increased by sulforaphane treatment in a concentration-dependent manner. Although further studies are needed, the present work suggests that sulforaphane may be a potential rhemoprevetiveichemotherapeucc agent for the treatment of human cancer cells.