• Korean Journal of Weed Science
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• v.15 no.2
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• pp.148-153
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• 1995

Glyphosate (N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves or sprayed to the whole plants of tomato(Lycopersicon esculentum Mil var. Moneymaker) induced the rapid inhibition of 5-enolpyruvyl skimic acid 3-phosphate synthase(EPSP-synthase). It shows that EPSP-synthase activity precedes chlorophyll loss. There is no difference in EPSP-synthase activity between in vivo tomato meristem and cell suspension culture if glyphosate is not applied. The EPSP-synthase activity is in a range of 4 to 6 nkat per mg protein. The inhibition of EPSP-synthase action is induced within 36 h after glyphosate application while the Chl contents were reduced 48 h after the application. In cell suspension culture of tomato and Corydalis (Corydalis sempervirens), a sublethal concentration of glyphosate retards the fresh weight increase and prolonged lag phase. The fresh weight is reached maximal about 14 days after the subculture in the presence of glyphosate. The inhibitory effect of glyphosate on EPSP-synthase is remarkably induced in lag phase.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.105-110
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• 2016

This paper provides the current status of weed science and prospects for the development of weed science based on the research trends presented at the 7th International Weed Science Conference in 2016. Approximately 520 researchers from 59 countries, including Korea, participated in the conference and presented 625 papers in nine research areas. Major research topics were herbicide resistance, weed ecology, weed management in agricultural and non-agricultural lands, herbicide spray technology, and non-chemical weed control. Studies on herbicide resistance presented more than 30% of all papers presented. Particularly, resistance to non-selective herbicides, such as glyphosate and glufosinate-ammonium, and non-target sites of resistance mechanisms were the main subjects of the herbicide resistance research area. Moreover, the conference focused on research concerning herbicide resistant weeds of staple crops of the world (corn, wheat, and rice). Arylex was introduced as a new compound which has a mode of herbicidal action similar to synthetic auxin. Three compounds being developed as HPPD inhibitors were studied for ways to reduce their toxicity and tested as mixed with safeners. Additionally, parasitic weeds, which are not native to Korea, are an expanding research subject in the world. Although 45 years have passed since the first report of herbicide resistance in 1970, herbicide resistance remains a serious problem in most intensive cropping systems of the world and will continue to be a major area of study in the future.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.361-371
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• 2013

This study was performed to determine the antimelanogenic effect and tyrosinase inhibitory activities of anthocyanin rich fraction (AN-SLP) from Liriope platyphylla Wang et Tang seeds. Anthocyanins isolated from L. platyphylla seeds revealed the presence of four major anthocyanin components, which were tentatively identified as delphinidin-3-Oglucoside, delphinidin-3-O-rutinoside, petunidin-3-O-rutinoside, and malvidin-3-O-rutinoside using semipreparative HPLC, $^1H$-NMR, $^{13}C$ NMR, FAB-MS and LC/ES-MS. The inhibitory effect of AN-SLP on tyrosinase activity was studied using in vitro (against mushroom tyrosinase) and ex vivo (against B16 melanoma cell tyrosinase) models. Cellular tyrosinase activity was decreased by AN-SLP treatment in B 16 melanoma cells through dose dependent manner, but AN-SLP did not inhibit mushroom tyrosinase and L-DOPA oxidation directly. AN-SLP showed melanin inhibition by 53.2% at 50 ${\mu}g/m{\ell}$ which was 0.7 times more efficient than the antimelanogenic effect of commercial arbutin and kojic acid (36.5%) also did not show cell toxicity. Additionally, AN-SLP inhibited the activity of ${\alpha}$-glucosidase and the glycosylation of tyrosinase in melanoma cell. The resulting unsaturated glycosylation of tyrosinase makes it unstable and disturb correct transportation. From theses results, we conclude that AN-SLP could be used as anti-melanogenic agent for skin whitening.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.231-237
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• 2017

Background: Cisplatin is one of the most extensively used chemotherapeutic agents for the treatment of cancer, including bladder, and ovarian cancers. However, it has been shown to induce nephrotoxicity, despite being an outstanding anti-cancer drug. In this study, we investigated the protective effect of dopaol ${\beta}$-D-glucoside (dopaol) on cisplatin-induced nephrotoxicity. Methods and Results: To confirm the protective effect of dopaol on cisplatin-induced nephrotoxicity, HK-2 cells were treated with $20{\mu}M$ cisplatin and $80{\mu}M$ dopaol. Cisplatin increased apoptosis, caspase-3 activity and mitochondrial dysfunction; however pretreatment with $80{\mu}M$ dopaol successfully attenuated apoptosis, caspase-3 activity and mitochondrial dysfunction. To evaluate the protective effect dopaol on cisplatin-induced nephrotoxicity in vivo, we used an animal model (balb/c mice, 20 mg/kg, i.p. once/day for 3 day). The results were similar to those obtained using HK-2 cells; renal tubular damage and neutrophilia induced by cisplatin reduced following dopaol injection (10 mg/kg, i.p. once/day for 3 day). Conclusions: These results indicate that dopaol treatment reduced cisplatin-induced nephrotoxicity in vitro and in vivo, and can be used to treat cisplatin-induced nephrotoxicity. However, further studies are required to determine the toxicity high dose dopaol and the signal pathways involved in its mechanism of action in animal models.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.322-327
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• 2017

Background: Cynaroside is a flavone, a flavonoid-like compound, known by different names (luteoloside and cinaroside). It is commonly found in Lonicera japonica Thunb., Chrysanthemum moriflium, and Angelica keiskei. The process of cell death has been classified as necrosis and apoptosis. Necrosis refers to unregulated cell death induced by a chemotherapeutic agent. Doxorubicin is an anthracycline anti-cancer drug used to treat acute leukemia, cancer, and lymphoma. However, it induces nephrotoxicity including tubular damage. Therefore, we investigated the protective effect of cynaroside against doxorubicin-induced necrosis in HK-2 cells. Methods and Results: To confirm the beneficial effect of cynaroside on doxorubicin-induced necrosis, HK-2 cells, a human proximal tubule epithelial cell line were treated with $10{\mu}M$ doxorubicin and $80{\mu}M$ cynaroside. Doxorubicin treatment resulted in increased DNA fragmentation, caspase-3 activity and mitochondria hyperactivation during cell necrosis. However, pretreatment with $80{\mu}M$ cynaroside attenuated DNA fragmentation, caspase-3 activity and mitochondria hyperactivation induced by $10{\mu}M$ doxorubicin in HK-2 cells. Conclusions: These results indicated that pretreatment with cynaroside ameliorated doxorubicin-induced necrosis in HK-2 cells. Therefore, cynaroside be used as a therapeutic agent for improving doxorubicin-induced nephrotoxicity. However, further studies are required to evaluated the toxicity of cynaroside treatment in animals and to determine its protective effect against doxorubicin-induced nephrotoxicity in an animal model.

• Korean Journal of Materials Research
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• v.21 no.7
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• pp.384-390
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• 2011

Ti-6Al-4V ELI (Extra Low Interstitial) alloy has been widely used as an alternative to bone due to its excellent biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity. Therefore, nontoxic biomaterials with a low elastic modulus should be developed. However, the fabrication of a uniform coating is challenging. Moreover, the coating layer on Ti and Ti alloy substrates can be peeled off after implantation. To overcome these problems, it is necessary to produce bulk Ti and Ti alloy with hydroxyapatite (HA) composites. In this study, Ti, Nb, and Zr powders, which are biocompatible elements, were milled in a mixing machine (24h) and by planetary mechanical ball milling (1h, 4h, and 6h), respectively. Ti-35%Nb-7%Zr and Ti-35%Nb-7%Zr-10%HA composites were fabricated by spark plasma sintering (SPS) at $1000^{\circ}C$ under 70MPa using mixed and milled powders. The effects of HA addition and milling time on the biocompatibility and physical and mechanical properties of the Ti-35%Nb-7%Zr-(10%HA) alloys have been investigated. $Ti_2O$, CaO, $CaTiO_3$, and $Ti_xP_y$ phases were formed by chemical reaction during sintering. Vickers hardness of the sintered composites increases with increased milling time and by the addition of HA. The biocompatibilty of the HA added Ti-Nb-Zr alloys was improved, but the sintering ability was decreased.

• Radiation Oncology Journal
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• v.13 no.3
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• pp.233-241
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• 1995

Purpose : To analyse clinical outcome and prognostic factors according to treatment modality, this paper report our experience of retrospective study of patients with esophageal cancer Materials and Methods : One hundred and ten patients with primary esophageal cancer who were treated in Presbyterian Medical Center from May 1985 to December 1992. We analysed these patients retrospectively with median follow up time of 28 months, one hundred and four patients($95{\%}$) were followed up from 15 to 69 months. In methods, twenty-eight patients were treated with median radiation dose irradiated 54.3Gy only. Fifty-six patients were treated with combined chemoradiotherapy. Sixteen cases of these patients were treated with concurrent chemoradiation and the other patients(forty cases) were treated sequential chemoradiotherapy. In concurrent chemoradiotherapy group, patients received 5-FU continuous IV infusion for 4 days. Cisplatin IV bolus. and concurrent esophageal irradiation to 30 Gy. After that patients received 5-FU continuous IV, Cisplatin bolus injection and Mitomycin-C bolus IV, Bleomycin continuous IV, and irradiation to 20 Gy. In sequential chemoradiotherapy group, the chemotherapy consisted of 5-FU 1,000mg/$m^2$ administered as a continuous 24 hour intravenous infusion during five days and Cisplatin 80-100mg/$m^2$ bolus injected, or Bleomycin, Vinblastine, Cisplatin, Methotrexate were used of 1 or 2 cycles. After preoperative concurrentm chemoradiation twenty-six patients underwent radical esophagectomy. Results : Ninety-three patients could be examined for response assessment, By treatment modality, response rates were $85.1{\%}$ for radiation alone group and $86.3{\%}$ for combined chemoradiation group. But in operation group, after one cycle of concurrent chemoradiation treatment, response rate was $61.9{\%}$. The pathologic complete response were $15.4{\%}$ in operation group. Overall median survival was II months and actuarial 5-year survival rate was $8{\%}$. The median survival interval was 6 months for radiation alone group, 11 months for combined chemoradiation group and 19 months for operation group. And also median survival was 19 months for complete responder group that 8 months for noncomplete responder group. In univariative analysis, statistically significant prognostic factors were tumor size, clinical stage, tumor response, and operation. In multivariative analysis, significantly better survival was associated with clinical stage, tumor response, radiation dose, and operation. Conclusion : Compared with radiotherapy alone, combined multimodality may improve the median survival in patients with localized carcinoma of the esophagus and toxicity is acceptable.

• Toxicological Research
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• v.26 no.2
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• pp.157-162
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• 2010

In this study, we investigated the atmospheric heavy metal concentrations in the particulate matter inside the subway stations of Seoul. In particular, we examined the correlation between the heavy metals and studied the effect of the heavy metals on cell proliferation. In six selected subway stations in Seoul, particulate matter was captured at the platforms and 11 types of heavy metals were analyzed. The results showed that the mean concentration of iron was the highest out of the heavy metals in particulate matter, followed by copper, potassium, calcium, zinc, nickel, sodium, manganese, magnesium, chromium and cadmium in that order. The correlation analysis showed that the correlations between the heavy metals was highest in the following order: (Cu vs Zn), (Ca vs Na), (Ca vs Mn), (Ni vs Cr), (Na vs Mn), (Cr vs Cd), (Zn vs Cd), (Cu vs Cd), (Ni vs Cd), (Cu vs Ni), (K vs Zn), (Cu vs K), (Cu vs Cr), (K vs Cd), (Zn vs Cr), (K vs Ni), (Zn vs Ni), (K vs Cr), and (Fe vs Cu). The correlation coefficient between zinc and copper was 0.937, indicating the highest correlation. Copper, zinc, nickel, chromium and cadmium, which are generated from artificial sources in general, showed correlations with many of the other metals and the correlation coefficients were also relatively high. The effect of the heavy metals on cell proliferation was also investigated in this study. Cultured cell was exposed to 10 mg/l or 100 mg/l of iron, copper, calcium, zinc, nickel, manganese, magnesium, chromium and cadmium for 24 hours. The cell proliferation in all the heavy metal-treated groups was not inhibited at 10 mg/l of the heavy metal concentration. The only exception to this was with the cadmium-treated group which showed a strong cell proliferation inhibition. This study provides the fundamental data for the understanding of simultaneous heavy metal exposure tendency at the time of particulate matter exposure in subway stations and the identification of heavy metal sources. Moreover, this study can be used as the fundamental data for the cell toxicity study of the subway-oriented heavy metal-containing particulate matter.

• Journal of Life Science
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• v.7 no.4
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• pp.316-321
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• 1997

The effects of the silver ion-exchanged water treatment agent (Ag-Os) upon E. coli RB 797 and Bacillus sp. have been discussed in this study. Silver ion causes a number of toxic effects with no known biological function. Silver ion-exchanged water treatment agent (Ag-Os) using oyster shell here showed antimicrobial activities. the soluble form of silver ion in water is more toxic to the growth of Bacillus sp. than that of E. Coli RB 797. The minium amount of Ag-Os needed for growth inhibition is 0.2 mg/ml for E. Coli RB 797 and 0.02 mg/ml for Bacillus sp., which is consistant with the data of the survival cell fraction. Binding studies suggested that binding of silver to the cell surface was a rapid, metabolic-independent process and different from active transport. Bacillus sp. showed more binding than E. Coli RB 797. Reducing substances of the cell cultures in the presence of Ag-Os was detected using Methylen blue as an indicator. From these results, we suggest that Ag-Os is effective as an antimicrobial agent on E. Coli RB 797 and Bacillus sp. and silver binds to the cells through rapid, metabolic-independent process and might complex to sulfur group in the cells for its toxicity.

• Journal of Life Science
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• v.23 no.11
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• pp.1371-1380
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• 2013

The effect of Monascus-fermented Angelica gigas Nakai (AFAG) on the contents of serum lipids and tissue lipid peroxidation was investigated in alcohol feeding rats (Alc group). The serum contents of total lipid and free fatty acid in the alcohol feeding rats were significantly increased, but these increases tended to decrease in the AFAG group. The content of serum triglyceride was also significantly decreased in the AFAG group compared to the other groups. The serum content of total-cholesterol was not significantly different between the normal group and the AFAG group. The content of HDL-cholesterol in serum was slightly increased in the AFAG group compared to the Alc group. The content of thiobarbituric acid reactive substances (TBARS) in the liver, heart, spleen, and testis were significantly increased in the Alc group compared to the normal group, but these increases were significantly decreased in the AFAG group. The content of liver zinc was decreased in the Alc group and it was significantly increased in the AFAG group, which suggested that the lipid peroxidation contents are inversely correlated with the liver zinc content. The hepatic glutathione concentration was significantly decreased in the Alc group, but this content was significantly increased in the AFAG group, and it showed the antioxidant ability of glutathione. These activities were also compared to the standard silymarin drug treatment. Thus, the findings of the present study indicated the significant antioxidant and antihyperlipidemic activity of Monascus-fermented Angelica gigas Nakai against ethanol-induced toxicity.