• Korean Journal of Food Science and Technology
• /
• v.17 no.2
• /
• pp.121-127
• /
• 1985

In studying the structural work on ciguatoxin, parrot fish collected were identified as Scarus sordidus, S. frenatus, S. scaber and S. pectarlis, in which only S. sordidus contained toxic materials. Crude toxins obtained by silicic acid column chromatography, could be separated on a DEAE-cellulose column into two fractions, ST-1(less polar) and ST-2(polar) eluted with chloroform and chloroform-methanol(1:1). Furthermore ST-1 could be changed into ST-2 by repeated chromatography on DEAE-cellulose. Rf values of ST-1 and ST-2 were 0.60-0.75 and 0.30-0.54 on TLC coated with silica gel 60F-254 developed by chloroform-methanol-water-acetic acid (90:9.5:0.2:0.3) mixture. The peaks of ST-1 and ST-2 were not observed on each HPLC chromatogram at low sensitivity(2X), but by bioassay they were detected in the fraction of 24-27ml(less polar toxin, 120ng) and 22-27 ml (polar toxin, 150 ng). Less polar ciguatoxin from morey eel viscera also showed its peak in the same elution volume(25ml). Being subjected to chromatography on basic aluminum oxide (activity grade I) or to alkaline treatment, followed by basic aluminum oxide (activity grade I) chromatography ST-1 toxin was remarkably converted into the polar toxic component supposed to be polar ciguatoxin in both cases. In the latter case, approximately 74% of the residual toxicity was changed into the polar component, accompanied by about 50% loss of the initial toxicity. More than 26% of ST-2 toxicity was transformed into the less polar toxic component supposed to be less polar ciguatoxin on a deactivated aluminum oxide (activity grade V) column.

• Radiation Oncology Journal
• /
• v.16 no.2
• /
• pp.159-165
• /
• 1998

Purpose : The best prognosis for hepatocellular carcinoma can be achieved with surgical resection. However, the number of resected cases is limited due to the advanced lesion or associated liver disease. A trial of combined transcatheter arterial chemoembolization(TACE) and local radiotherapy(RT) for unresectable hepatocellular carcinoma(HCC) was prospectively conducted and its efficacy and toxicity were investigated. Materials and Methods : From 1992 to 1994, 30 Patients with unresectable HCC due either to advanced lesion or to associated cirrhosis were entered in the study Exclusion criteria included the presence of extrahepatic metastasis, liver cirrhosis of Child's class C, tumors occupying more than two-thirds of the whole liver, and an ECOG scale of more than 3. Patient cHaracteristics were : mean tumor size $8.95\pm3.4cm$, serum AFP+ in all patients, portal vein thrombosis in all patients, liver cirrhosis in 22 patients, and UICC stage III and IVA in 10 and 20 patients, respectively. TACE was performed with the mixture of Lipiodol(5ml) and Adriamycin(50mg) and Gelfoam embolizatin. RT(mean dose $44.0\pm9.3Gy$) 10 days with conventional fractionation. Results : An objective response was observed in 19 patients($63.3\%$). Survival rates at 1 2, and 3 years were $67\%,\;33.3\%$ and $22.2\%$, respectively. Median survival was 17 months. There were 6 patients surviving more than 3 years. Distant metastasis occurred in 10 patients, with 8 in the lung only and 2 in both lung and bone, Toxicity included transient elevation of liver function test in all patients, fever in 20, thrombocytopenia in 4, and nausea and vomiting in 1. There was no treatment-related death. Conclusion : Combined TACE and RT appear to produce a favorable response and survival results with minimal toxicity.

• Korean journal of applied entomology
• /
• v.51 no.1
• /
• pp.47-58
• /
• 2012

Effect of a new crop protectant 'Bt-Plus' on natural enemies was analyzed in this study. Tested natural enemies included two parasitic species of $Aphidius$ $colemani$ and $Eretmocerus$ $eremicus$, and four predatory species of $Harmonia$ $axyridis$, $Orius$ $laevigatus$, $Amblyseius$ $swirskii$, and $Phytoseiulus$ $persimilis$. 'Bt-Plus' was formulated by combination of three entomopathogenic bacteria ($Xenorhabdus$ $nematophila$ (Xn), $Photorhabdus$ $temperata$ subsp. $temperata$ (Ptt), $Bacillus$ $thuringiensis$ (Bt)) and bacterial metabolite (BM). All three types of 'Bt-Plus' showed significantly higher toxicities against fourth instar $Plutella$ $xylostella$ larvae than Bt single treatment. Two types of bacterial mixtures ('Xn+Bt' and 'Ptt+Bt') showed little toxicity to all natural enemies in both contact and oral feeding assays. However, 'BM+Bt' showed significant toxicities especially to two predatory mites of $A.$ $swirskii$ and $P.$ $persimilis$. The acaricidal effects of different bacterial metabolites were evaluated against two spotted spider mite, $Tetranychus$ $urticae$. All six BM chemicals showed significant acaricidal effects. The BM mixture used to prepare 'Bt-Plus' showed a high acaricidal activity with a median lethal concentration at 218.7 ppm (95% confidence interval: 163.2 - 262.3). These toxic effects of bacterial metabolites were also proved by cytotoxicity test against Sf9 cells. Especially, benzylideneacetone, which was used as a main ingredient of 'BM+Bt', showed high cytotoxicity at its low micromolar concentration.

• Korean journal of applied entomology
• /
• v.48 no.2
• /
• pp.123-158
• /
• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.12
• /
• pp.696-704
• /
• 2015

This study was carried out to evaluate the optimum operational condition of Semi-continuously Fed and Mixed Reactor (SCFMR) to treat the dairy cow manure and saw dust mixture. Step-wise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) were utilized until the biogas volume became significantly decreased at mesophilic temperature ($35^{\circ}C$). The optimum operating condition of the SCFMR fed with TS 13% dairy cow manure and saw dust mixture was found to be an HRTs of 25 days and its corresponding OLRs of $4.45kg\;VS/m^3-day$. At this condition the biogas and methane production rates were 1.44 v/v-d and 1.12 v/v-d (volume of biogas per volume of reactor per day), respectively and the TVS removal efficiency of 37% was achieved. The successful operation with such a high OLR was due to the high reactor alkalinity concentration of 14,500~15,600 mg/L as $CaCO_3$ as a result of the characteristic of the original substrate, dairy cow manure and saw dust mixture whose alkalinity was more than 8,000 mg/L as $CaCO_3$. The parameters for the reactor stability, the ratios of volatile acids and alkalinity concentrations (V/A) and the ratio of propionic acid and acetic acid concentrations (P/A) appeared to be 0.11 and 0.43, respectively, that were greatly stable in operation. Free ammonia toxicity was not experienced due to the long term acclimation by the reactor TS content ranged 7.2~10.4% during the entire operational period.

• Environmental Mutagens and Carcinogens
• /
• v.24 no.1
• /
• pp.33-39
• /
• 2004

To validate and to estimate the chemical hazard playa very important role to environment and human health. The detection of many synthetic chemicals including agrochemicals that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. Pyrazosulfuron-ethyl [Ethyl-5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate, $C_{14}H_{18}N{6}O_{7}S,$ M.W. =414.39, CAS No. 93697-74-6], is one of well known rice herbicide belong in the sulfonyl urea group. To clarify the genotoxicity of this agrochemical, Ames bacterial reversion assay, in vitro chromosomal aberration assay with Chinese hamster lung (CHL) fibroblast and bone marrow micronucleus assay in mice were subjected. In Ames assay, although pyrazosulfuron-ethyl revealed cytotoxic at 5,000-140 $\mug/plate$ in Salmonella typhimurium TA100, no dose-dependent mutagenic potential in 4.4～70 $\mug/plate$ of S. typhimurium TA 98, TA 100, TA1535 and TA 1537 both in the absence and presence of S-9 metabolic activation system was observed. Using CHL fibroblasts, the 50% cell growth inhibition concentration $(IC_{50})$ of pyrazosulfuron-ethyl was determined as 1,243 $\mug/mL,$ and no chromosomal aberration was observed both in the absence and presence of S-9 mixture in the concentration range of 311-1,243 $\mug/mL.$ And also, in vivo micronucleus assay using mouse bone marrow, pyrazosulfuron-ethyl revealed no remarkable induction of MNPCE (micronucleated polychromatic erythrocytes/1000 polychromatic erythrocytes) in the dose range of 625-2,500 mg/kg body weight when administered orally. Consequently, Ames bacterial gene mutation with Salmonella typhimurium, in vitro chromosome aberration with mammalian cells and in vivo bone marrow micronucleus assay revealed no clastogenic potential of pyrazosulfuron-ethyl in this study.

• Journal of Gastric Cancer
• /
• v.1 no.4
• /
• pp.221-227
• /
• 2001

Purpose: We have carried out prospective randomized clinical trial to compare survival benefit and side effect among three postoperative adjuvant chemotherapeutic regimens in serosa-negative gastric cancer patients. Materials and Methods: Total 317 cases were recognized as serosa negative and randomized into three groups at operating room. Out of them, 172 cases were excluded because of various reasons and 135 cases were analyzed finally; Group A 36 cases, Group B 49 cases, Group C 50 cases. Group A were treated with intravenous FP combination therapy, group B with MF combination therapy and group C with oral $UFT^{(R)}$ (mixture of Tegafur and Uracil) for one year. The median follow-up period was 30 months. Results: $88.9\%$ of Group A, $83.7\%$ of Group B and $90.4\%$ of Group C received adequate chemotherapy. The complication rates of Group A ($44.4\%$) was significantly higher than group B ($20.4\%$) and group C ($24.0\%$)(P<0.05). Most frequent complications were nausea and vomiting. The 3-year survival rates and disease-free survival rates were $92.2\%$ and $89.9\%$ respectively (Group A: $96.6\%,\;87.8\%$, B: $90.3\%,\;87.7\%$, C: $95.7\%,\;93.8\%$). There were no significant differences in survival rate and disease-free survival rate among the three groups (P>0.05). Conclusion: This study might suggest that the survival benefit of postoperative adjuvant chemotherapy for gastric Pseudomonas aeruginosa, and therefore it may be a useful adjunct tool for detection of Pseudomonas aeruginosa infection in combination with other conventional techniques.

• Economic and Environmental Geology
• /
• v.48 no.3
• /
• pp.187-197
• /
• 2015

Oriental mineral medicines are single or mixture of more than one mineral species or rock/fossil which are used to treat disease. Mineral medicines remove harmful or useless substances to decrease toxicity and secondary effects, and cause the manufacture of medical compounds with increased efficacy. The extraction test is an accepted in vitro system to predict the bioaccessibility of major and minor elements from mineral medicine. It incorporates gastrointerstinal tract parameters representative of a human body that including stomach and small intestinal pH which are the same as digestion condition. The bioaccessibility of a mineral medicine is the fraction that is soluble in the gastrointestinal environment and is available for absorption. Reaction path modeling in the human body can predict digestion with gastric fluid as well as absorption in the small intestine, existence in body fluids and reaction progress of the exhaust process according to pH conditions in body. Also reaction path modeling can predict bioavailability, which is equal to existence rate in the body and the form and amount of a medicine in the body after intake. The study results from predicating the existence form mineral medicines in the body, and proving the effective ingredient using bioaccessibitily and human risk assessment, suggest these that should be necessary data for new medicine development.

• Korean Journal of Food Science and Technology
• /
• v.50 no.4
• /
• pp.451-456
• /
• 2018

The current study was conducted to confirm the anti-cancer effect of Sarijang, which is a mixture of extracts from purple bamboo salt, Rhynchosia nulubilis, garlic, and Ulmi cortex. Nude mice were injected with a human-derived colorectal cancer cell (HCT116 cell line) and subsequently administered Sarijang for 4 weeks, following which the body weight, organ weight, and tumor size were measured. To evaluate the anti-cancer mechanism of Sarijang, the levels of p16 and extracellular signal-regulated kinase (ERK), cell cycle regulators in colorectal cancer, were measured. To evaluate the toxicity of Sarijang on liver and kidney, aspartate transaminase, alanine transaminase, blood urea nitrogen, and creatinine were analyzed. Sarijang not only reduced the tumor size by enhancing p16 and suppressing ERK, but also showed no side-effect in the liver and kidneys. Taken together, Sarijang has the potential to inhibit tumor growth without side effects, and may be used as a useful functional food.

• Polymer(Korea)
• /
• v.29 no.3
• /
• pp.260-265
• /
• 2005

The initial burst of drug release is an important role in the controlled delivery of drug having hish toxicity and narrow therapeutic ranges. Nanosphere composed of monolayer could not achieve precisely controlled drug release because of the initial burst of drug on surface. In this study, double layered nanosphere was prepared for sustained drug delivery without initial burst. Double layered nanosphere composed of dextran and PLGA was fabricated by using conventional W/O/W double emulsion method. To control surface tension on the outer layer of nanospheres, PVA was used as a surfactant. Release behavior of dextran as model drug was observed as the $3{\times}1$mm wafers formed by compression mould in the deionized water for 7 days. Double layered nanosphere has sustained release behavior, in contast to single layered nanospheres. such as mechanical mixture and dextran nanospheres. Especially, nanosphere containing PVA $0.2\%$ has shown nearly the zero-order release profile. As a result of this study, double layered nanospheres has more sustained release profile of drug without the initial burst and the release behavior of dexoan on tile double layered nanospheres was controlled by the contents of PVA as a surfactant.