• Korean Journal of Weed Science
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• v.31 no.2
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• pp.119-133
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• 2011

Sulfonylurea (SU)-resistant weeds include seven annual weeds such as Monochoria vaginalis, Scirpus juncoides and Cyperus difformis, etc., and three perennial weeds of Scirpus planiculmis, Sagittaria pigmaea and Eleocharis acicularis as of 2010 since identification Monochoria korsakowii in the reclaimed rice field in 1998. The Echinochloa oryzoides resistant to acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitors has been confirmed in wet-direct seeding rice field of the southern province, Korea in 2009. In the beginning of occurrence of SU-resistant weeds the M. vaginalis, S. juncoides and C. difformis were rapidly and individually spreaded in different fields, however, theses resistant weeds have been occurring simultaneously in the same filed as time goes by. The resistant biotype by weed species demonstrated about 10- to 1,000-fold resistance, base on $GR_{50}$ (50% growth reduction) values of the SU herbicides tested. And the resistant biotype of E. oryzoides to cyhalofop-butyl, pyriminobac-methyl, and penoxsulam was about 14, 8, and 11 times more resistant than the susceptible biotype base on $GR_{50}$ values. In history of paddy herbicides in Korea, the introduction of SU herbicides including besulfuron-metyl and pyrazosulfuron-ethyl that control many troublesome weeds at low use rates and provide excellent crop safety gave farmers and many workers for herbicide business refreshing jolt. The products and applied area of SU-included herbicides have been rapidly increased, and have accounted for about 69% and 96%, respectively, in Korea. The top ten herbicides by applied area were composed of all SU-included herbicides by 2003. The concentrated and successive treatment of ACCase and ALS inhibitors for control of barnyardgrass in direct-seeded rice led up to the resistance of E. oryzoides. Also, SU-herbicides like pyrazosulfuron-ethyl and imazosulfuron which are effective to barnyardgrass can be bound up with the resistance of E. oryzoides. The ALS activity isolated from the resistant biotype of M. korsakowii to SU-herbicides tested was less sensitive than that of susceptible biotype. The concentration of herbicide required for 50% inhibition of ALS activity ($I_{50}$) of the SU-resistant M. korsakowii was 14- to 76-fold higher as compared to the susceptible biotype. No differences were observed in the rates of [$^{14}C$]bensulfuron uptake and translocation. ALS genes from M. vaginalis resistant and susceptible biotypes against SU-herbicides revealed a single amino acid substitution of proline (CCT), at 197th position based on the M. korsakowii ALS sequence numbering, to serin (TCT) in conserved domain A of the gene. Carfentrazone-ethyl and pyrazolate were used mainly to control SU-resistant M. vaginalis by 2006, the early period, in Korea. However, the alternative herbicides such as benzobicyclone, to be possible to control simultaneously the several resistant weeds, have been developing and using broadly because the several resistant weeds have been occurring simultaneously in the same filed. The top ten herbicides by applied area in Korea have been occupied by products of 3-way mixture type including herbicides with alternative mode of action for the herbicide resistant weeds. Mefenacet, fentrazamide and cafenstrole had excellent controlling effects on the ACCase and ALS inhibitors resistant when they were applied within 2 leaf stage.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.209-217
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• 2007

Purpose: Multidrug resistance (MDR) of the cancer cells related to mdr1 gene expression can be effectively treated by selective short hairpin RNA for mdr1 gene (shMDR). Sodium/iodide symporter (NIS) gene is well known to have both reporter and therapeutic gene characteristics. We have co-transfected both shMDR and NIS gene into colon cancer cells (HCT15 cell) expressing MDR and Tc-99m sestamibi and I-125 uptake were measured. In addition, cytotoxic effects of doxorubicin and I-131 therapy were also assessed after transfection. Material and Methods: At first, shMDR was transfected with liposome reagent into human embryonic kidney cells (HEK293) and HCT cells. shMDR transfection was confirmed by RT-PCR and western blot analysis. Adenovirus expressing NIS (Ad-NIS) gene and shMDR (Ad-shMDR) were co-transfected with Ad-NIS into HCT15 cells. Forty-eight hours after infection, inhibition of P-gycoprotein (Pgp) function by shMDR was analyzed by a change of Tc-99m sestamibi uptake and doxorubicin cytotoxicity, and functional activity of induced NIS gene expression was assessed with I-125 uptake assay. Results: In HEK293 cells transfected with shMDR, mdr1 mRNA and Pgp protein expressions were down regulated. HCT15 cells infected with 20 MOI of Ad-NIS was higher NIS protein expression than control cells. After transfection of 300 MOI of Ad-shMDR either with or without 10 MOI of Ad-NIS, uptake of Tc-99m sestamibi increased up to 1.5-fold than control cells. HCT15 cells infected with 10 MOI of Ad-NIS showed approximately 25-fold higher I-125 uptake than control cells. Cotransfection of Ad-shMDR and Ad-NIS resulted in enhanced cytotoxic by doxorubicin in HCT15 cells. I-131 treatment on HCT15 cells infected with 20 MOI of Ad-NIS revealed increased cytotoxic effect. Conclusion: Suppression of mdr1 gene expression, retention of Tc-99m sestamibi, enhanced doxorubicin cytotoxicity and increases in I-125 uptake were achieved in MDR expressing cancer cell by co-transfection of shMDR and NIS gene. Dual therapy with doxorubicin and radioiodine after cotransfection shMDR and NIS gene can be used to overcome MDR.

• Research in Plant Disease
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• v.16 no.3
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• pp.274-278
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• 2010

Potato late blight caused by Phytophthora infestans was the most constrain disease at potato cultivation areas. The mating type distribution and fungicides response of P. infestans were investigated to elucidate the changes of pathogen from Gangwon province. On the fungal isolates in 2006, 58.7% were A1 mating type and 41.3% were A2 mating type. In 2007, A1 mating type isolates increased to 93.3% and A2 mating type isolates were collected from Jinbu areas as much as 6.7%. About 234 isolates analysed for metalaxyl response, the results was resistance 73.7%, intermediate 18.8% and sensitive 7.5% in 2006. And it was resistance 59.4%, intermediate 4.0% and sensitive 36.6% in 2007. It meant that mating type distribution and fungicide response were very different over the collection sites. Minimal inhibition concentration (MIC) of dimethomorph examined with 126 isolates in 2006 and 106 isolates in 2007. MIC over $1.0\;{\mu}g/ml$ was 56.3% in 2006 and it was 3.8% in 2007. The average $EC_{50}$ value of P. infestans was $0.37\;{\mu}g/ml$ in 2006, but it decreased to $0.12\;{\mu}g/ml$ in 2007. Fungicides response and pathogenesis of P. infestans should be monitored continuously to enhance the chemical efficacy at potato fields.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.57-62
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• 2006

Several methods for determining the response of corn to glyphosate were investigated to provide a fast and reliable method for identifying glyphosate-resistant corn in vivo. Two bioassays were developed. One assay is named 'whole plant / leaf growth assay', in which the herbicide glyphosate is applied on the upper part of 3rd leaf and the growth of herbicide-untreated 4th leaf is measured at 3 day after treatment. in this assay, the leaf growth of conventional corn was inhibited in a dose dependent from 50 to $1600{\mu}g/mL$ of glyphosate and growth inhibition at $1600{\mu}g/mL$ was 55% of untreated control. The assay has the potential to be used especially in the case that the primary cause of glyphosate resistance is related with a reduction of the herbicide translocation. Another assay is named 'leaf segment / shikimate accumulation assay', in which the four excised leaf segments ($4{\times}4mm$) are placed in each well of a 48-well microtiter plate containing $200{\mu}L$ test solution and the amount of shikimate is determined after incubation for 24 h in continuous light at $25^{\circ}C$. In this assay, 0.33% sucrose added to basic test solution enhanced a shikimate accumulation by 3 to 4 times and the shikimate accumulation was linearly occurred from 2 to $8{\mu}g/mL$ of glyphosate, showing an improved response to the method described by Shaner et al. (2005). The leaf segment / shikimate accumulation assay is simple and robust and has the potential to be used as a high throughput assay in the case that the primary cause of glyphosate resistance is related with EPSPS, target site of the herbicide. Taken together, these two assays would be highly useful to initially select the lines obtained after transformation, to investigate the migration of glyphosate-resistant gene into other weeds and to detect a weedy glyphosate-resistant corn in field.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.929-937
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• 2016

The purpose of this study was to investigate the effect of Acanthopanax senticosus extract (ASE) (ethanol : DW=1:1, v/v) on inhibition of type 2 diabetes using an OLETF rat model via regulation of HbA1c and AGEs levels. Supplementation with ASE 0.1% and 0.5% effectively lowered levels of glucose, insulin, oral glucose tolerance test, and Homa-insulin resistance, suggesting reduced insulin resistance. Blood levels of HbA1c and AGEs were significantly reduced in a dose-dependent manner. As oxidative stress plays a key role in accelerating production of HbA1c and AGEs, which worsen symptoms of type 2 diabetes, levels of malonaldehyde and pro-inflammatory cytokines were measured. Lipid peroxidation in both blood and liver tissues was significantly reduced, and induction of pro-inflammatory cytokines interleukin-${\beta}$ and tumor necrosis factor-${\alpha}$, which elevate production of HbA1c and AGEs, was inhibited (P<0.05). To evaluate the possible cellular events after AGEs receptor activation, genetic expression of protein kinase C (PKC)-${\delta}$ and transforming growth factor (TGF)-${\beta}$ was measured by real-time polymerase chain reaction. Supplementation with both ASE 0.1% and 0.5% significantly inhibited mRNA expression of PKC-${\delta}$ and TGF-${\beta}$, indicating that ASE may have beneficial effects on preventing insulin-resistant cells or tissues from progressing to diabetic complications. Taken together, ASE has potential to improve type 2 diabetes by inhibiting insulin resistance and protein glycosylation, including production of HbA1c and AGEs. Anti-oxidative activities of ASE are a main requisite for reducing production of HbA1c and AGEs and are also related to regulation of the PKC signaling pathway, resulting in suppression of TGF-${\beta}$, which increases synthesis of collagen, prostaglandin, and disease-related proteins.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.389-397
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• 2019

Lysosomes are cellular organelles involved in energy metabolism and intracellular digestion in eukaryotic cells, including protease, nuclease, glycosidase, lipase, and phosphatase. Our previous studies have confirmed that egg white lysosomes had melanin decolorization and reduction activity. However, there have been few studies on skin barrier and skin regeneration as well as inhibition of melanin production by egg white lysosomes on B16F10 melanocyte cell line. In this study, we attempted to identify the effect of lysosome-related organelle extract (LOE) extracted from egg white on the melanin content change and skin barrier enhancement in cells. First, cytotoxicity evaluation was performed on B16F10 melanocyte cell line to confirm the whitening efficacy of LOE. Cytotoxicity by LOE was not observed at 20 mg/mL concentration, but cytotoxicity was observed at 40 mg/mL, and the maximum concentration value was set to 20 mg/mL in all subsequent experiments. LOE samples of 5, 10, 20 mg/mL inhibited melanin production by 61.5 ± 4.0%, 61.4 ± 7.3%, 58.3 ± 8.3%, respectivly, compared to α-MSH, a negative control in melanin contents assay. MITF mRNA expression was reduced by about 39.7 ± 3.2% compared to the α-MSH treatment group. TEER assay using HaCaT showed that LOE increased TEER resistance in a dose-dependent manner, indicating that LOE is involved in strengthening the skin barrier. LOE also increased the TEER resistance under TNF-α treatment. Skin barrier was normally restored by LOE even under the condition of inflammation. LOE had a positive effect on cell division and cell migration promotion, confirmed by the observing the effect of promoting cell migration by LOE through cell migration assay. Taken together, we expect that LOE can be developed as a cosmetic material to enhance has effects on skin regeneration and skin barrier strengthening as well as whitening function if enzyme stabilization and formulation technology are combined.

• Korean Journal of Weed Science
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• v.1 no.1
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• pp.57-68
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• 1981

To clarify the mode of uptake of butachlor (2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide) by rice seedlings, its phytotoxic action to growth and physiological activities, studies were conducted with rice seedlings, at the 6th or 7th leaf-stage, which were treated with nutrient solution containing butachlor 0, 1.8, 3.6, 7.2, 10.8 or 14.4 ppm for 1, 2 or 4 days, in other case, the solutions were thereafter renewed with the untreated nutrient solution for further growth. Uptake of butachlor by rice seedlings increased linearly with increase of its concentration and duration of uptake. Butachlor inhibited root growth more than shoot growth, furthermore, the inhibitory effect on the shoot growth was greater in height than in weight or leafing rate. After 4 day-treatment, the rates of shoot growth in weight were delayed for 4 days. Butachlor inhibited water uptake rapidly and linearly with increase of its external concentration. The reduced uptake of water was followed by slow increase in the stomatal resistance of leaves. Upon completion of butachlor treatment, rate of water uptake was recovered rapidly, but the stomatal resistance with lag in time. Butachlor did not affect the uptake of cation such as ammonium, potassium and calcium, but inhibited substantially uptake of nitrate in proportion to its concentration. Especially, butachlor did not affect synthesis and degradation of nitrate reductase. In addition, butachlor has shown much greater binding to the lipidic substances from rice roots than the proteinous material. The primary mechanism of phytotoxic action of butachlor does not seem to be its effect on the protein synthesis, but great affinity to membranes. The inhibition of water uptake, and its subsequent closure of stomates is thought very important for reduced growth under mild phytotoxicity.

• Tuberculosis and Respiratory Diseases
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• v.63 no.1
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• pp.42-51
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• 2007

Background: TRAIL is a cytokine that selectively induces apoptosis in various cancer cell lines. Gefitinib is new targeted drug applied in lung cancer that selectively inhibits EGFR tyrosine kinase. However, lung cancers have shown an initial or acquired resistance to these drugs. This study examined the effect of IGF-1R and its blockade on enhancing the sensitivity of lung cancer cell lines to TRAIL and gefitinib. Methods: Two lung cancer cell lines were used in this study. NCI H460 is very sensitive to TRAIL and gefitinib. On the other hand, A549 shows moderate resistance to TRAIL and gefitinib. The IGF-1R blockade was performed using adenoviruses expressing the dominant negative IGF-1R and shRNA to IGF-1R and AG1024 (IGF-1R tyrosine kinase inhibitor). Results: The adenovirus expressing dominant negative IGF-1R(950st) induced the increased expression of defective IGF-1R on the lung cancer cell surface, and the adenovirus-shIGF-1R effectively decreased the level of IGF-1R expression on cell surface. The genetic blockade of IGF-1R by the adenovirus-dnIGF-1R and AG1024 increased the sensitivity of A549 cells to TRAIL. The reduction of IGF-1R by transduction with ad-shIGF-1R also increased the sensitivity of the A549 cells to gefitinib. Conclusion: The blockade of IGF-1R through various mechanisms increased the sensitivity of the lung cancer cell line that was resistant to TRAIL and gefitinib. However, further studies using other cell lines showing acquired resistance as well as in vivo animal experiments will be needed.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.166-179
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• 2000

Background: The main reason for the failure of anti-cancer chemotherapy is the build up of resistance by cancer cells to apoptosis. The activation of NF-${\kappa}B$ in many cancer cell lines is reported to be underlying mechanism behind the build up of resistance of cancer cells to apoptosis. However, this relationship varied depending on the cells used in the experiments. In this study, the role of NF-${\kappa}B$ activation in the TNF-$\alpha$-induced apoptosis in lung cancer cell line was evaluated. Methods: NCI-H157 cells were used in all experiments. Cells were exposed to a high dose of TNF-$\alpha$(20 ng/ml) for 24 or 48 hours with or without blocking NF-${\kappa}B$ activation. TNF-$\alpha$-induced activation of NF-${\kappa}B$ was inhibited either by overexpression of $I{\kappa}B{\alpha}$-super repressor($I{\kappa}B{\alpha}$-SR) or by pre-treatment with proteasome inhibitor. Cell viability and apoptosis were evaluated with MTT assay and Western blot analysis for PARP fragment, respectively. Results: Cell viability of NCI-H157 cells was not affected by TNF-$\alpha$ treatment alone; however, combined treatment with TNF-$\alpha$ and cycloheximide reduced cell viability significantly, indicating that resistance to TNF-$\alpha$ is mediated by the new proteins synthesized after TNF-$\alpha$ stimulation. To evaluate the role of NF-${\kappa}B$ in the transcription of anti-apoptotic proteins. delete NF-${\kappa}B$ activation was inhibited before TNF-$\alpha$ stimulation. as described above. $AD5I{\kappa}B{\alpha}$-SR-transduction inhibited TNF-$\alpha$-induced nuclear translocation of p65. TNF-$\alpha$-induced cell death and apoptosis increased after inhibition of TNF-$\alpha$-induced activation of NF-${\kappa}$ by methods. Conclusion: These results suggest that TNF-$\alpha$-induced activation of NF-${\kappa}B$ may be closely related to the acquisition of the resistance to TNF-$\alpha$-induced apoptosis in lung cancer cells. Therefore. blocking of NF-${\kappa}B$ pathway can be a useful therapeutic modality in the treatment of lung cancer.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.89-119
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• 2004

This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.