• Radiation Oncology Journal
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• v.16 no.3
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• pp.225-231
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• 1998

Purpose : To determine whether TNF-$\alpha$ increases the antitumor effect of radiotherapy in murine syngeneic tumor system. Materials and Methods : Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I(hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter mice were treated with TNF-$\alpha$, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-$\alpha$ mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 ug per mouse for 7 days. In combination of radiation and TNF-$\alpha$, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. Results : Among 4 tested tumors, TNF-$\alpha$ alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-$\alpha$ showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-$\alpha$ alone and radiation, i.e., 6.5 days and 26.9 days, respectively(p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-$\alpha$ did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-$\alpha$ alone and radiation. Conclusions: TNF-$\alpha$ alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-$\alpha$ acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-$\alpha$ and radiation has different therapeutic potential depending on tumor model and further study is advocated.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.202-209
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• 2014

RNA interference (RNAi) is the method which controls phenotypes of gene in live cells. Chitinase is the enzyme helping digestion and absorption of old cuticles during the ecdysis of insects. In order to investigate molting-inhibition effect with the chitinase related gene in Spodoptera litura, RNA was extracted from the $5^{th}$ instars. cDNA was synthesized and then we obtained about 700 bp size chitinase. After PCR products were cloned into a pGEM T-easy vector, colonies were picked. DNA was extracted from the colony cultures. EcoR I enzyme was used to check whether PCR products were inserted or not. And then we confirmed vector band of about 3 kb and insert band of about 700 bp. To synthesize the dsRNA, each DNA was cut with Spe I and Nco I enzymes (Circular DNA became lineared DNA). After synthesis of dsRNA, approximately 5 ul dsRNA was injected into the $3^{rd}$ abdominal segment of S. litura $4^{th}$ larvae. The concentration of dsRNA was about $10{\mu}g/{\mu}l$. We confirmed larval-larval molting : there were phenotypically abnormal individuals - for instance malformation, molting inhibition and change of integument color. Pupaadult molting : there were phenotypically abnormal individuals - for instance molting inhibition, change of wings and malformation. Also we could investigate the pupation, emergence and variation about noninjection, treated with DW and dsRNA. Each pupation was non-injection 83.3%, DW 78.3% and dsRNA 66.7%. Each emergence was non-injection 90.0%, DW 72.3% and dsRNA 65.0%. So we considered that chitinase dsRNA induced molting inhibition effect. But each variation was non-injection 8.9%, DW 2.9% and dsRNA 19.2%. Therefore dsRNA group showed the highest variation value. When 18 hours after injecting dsRNA, we could obtain abnormal individual.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.250-256
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• 1998

D-Tagatose production from D-galactose was investigated using 35 type strains of American Culture Type Collection (ATCC) and Korean Collection for Type Cultures (KCTC) which have potential to produce D-tagatose. Enterobacter agglomerans ATCC 27987 was selected as a D-tagatose producing strain due to its short fermentation time and high production of D-tagatose. Optimization of the culture conditions for D-tagatose production by E. agglomerans ATCC 27987 was performed. Among various carbon sources, D-galactose was the most effective carbon source for D-tagatose production. As the D-galactose concentration was increased, cell growth and D-tagatose production increased. Effect of nitrogen sources on D-tagatose production was studied. Of inorganic nitrogen sources, ammonium sulfate was effective one for D-tagatose production and yeast extract was the most suitable organic nitrogen nutrient. The concentrations of inorganic compounds such as KH$_2$PO$_4$, K$_2$HPO$_4$, and MgSO$_4$$.$7H$_2$O were also optimized for D-tagatose production. The optimal medium was determined to contain D-galactose of 20 g/l, yeast extract of 5.0 g/l, (NH$_4$)$_2$SO$_4$ of 2.0 g/l, KH$_2$PO$_4$ of 5.0 g/l, K$_2$HPO of 5.0 g/l, and MgSO$_4$$.$7H$_2$O of 5 mg/l. The optimal environmental conditions in a 250-$m\ell$ flask were found to be pH of 6.0, temperature of 30$^{\circ}C$, and agitation speed of 150 rpm. D-tagatose of 0.41 g/l could be obtained in 24 h from 20 g/l D-galactose at the optimal culture condition without induction and cell concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.643-658
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• 1994

The sedimentary records of anthropogenic metal loads in the Suyeong Bay, Pusan were determined by combining the Pb-210 dating technique with the measurements of heavy metals in the sediment cores. The sedimentation rates of sediment particles ranged from $0.12\;to\;0.20\;g/m^2/yr\;or\;2.4{\sim}4.0\;mm/yr$ in accumulation rates. The lowest sedimentation rate was observed at station S3 which was characterized by a bottom with relatively low organic matter contents(e.g. TIL and TOC). Heavy metals showed generally higher concentrations at station S1 and S2 near the mouth of the Suyeong River than at station S3 and the outmost station S4. The contents of copper, lead and zinc in the sediment cores especially from station S1 and S2 began to increase around 1930, and were at their highest levels in the $1960{\sim}1970$ period as a result of increasing industrial activities. Concentrations of these heavy metals have slightly decreased since 1970, probably due to regulation of pollution discharge. The natural background levels of copper, lead and zinc in the sediments of this bay ranged $18{\pm}4ppm,\;28{\pm}6ppm\;and\;74{\pm}9ppm$, respectively, by averaging the contents in the sediment depths corresponding to periods between about 1900 and 1920 at the four stations. The total amounts of anthropogenic loads deposited in the sediments since about 1930 were estimated to be $9{\sim}291{mu}g/cm^2$ for lead, $165{\sim}1122{mu}g/cm^2$ for zinc and $20{\sim}208{mu}g/cm^2$ for copper. These values were remarkably high at stations S1 and S2 relative to the other two stations. At stations S1 and S2, the anthropogenic loads of lead, copper and zinc constituted $29{\sim}30\%,\;32{\sim}42\%\;and\;28{\sim}35\%$ of the total sedimentary inventories at the present day, respectively. These metal contents have a good correlation(r>0.7) with each other and cadmium measurements also show a positive linear relation with nickel or total organic nitrogen.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.476-481
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• 1997

For the effect of water-soluble degraded chitosan on the shelf-life of tofu, sterilized distilled water, 0.5% degraded chitosan, 0.5% fumaric acid and 0.5% lactic acid used as an tofu-immersion solutions were investigated by microbial counts, pH, and turbidity during the periods of storage at $4^{\circ}C$. After 2 weeks storage, total aerobic microbial counts in tap water and sterilized distilled water used as an immersion solution were $3.8\;{\times}\;10^8$ and $1.8\;{\times}\;10^8\;CFU/mL$, respectively. In 0.5% fumaric acid and 0.5% lactic acid immersion solutions, the microbial counts were around $10^7\;CFU/mL$ after 2 weeks while the microbial population in 0.5% water-soluble degraded chitosan were, however, $1.6\;{\times}\;10^5\;CFU/mL$ after 2 weeks and $1.7{\times}10^7\;CFU/mL$ after 3 weeks. The lag phase of initial contaminated microbes in 0.5% degraded chitosan solution was longer than those of other treatments. The addition of 0.5% fumaric acid and 0.5% lactic acid decreased the initial pH to pH 5.0, while those of tap water, sterilized distilled water and 0.5% degraded chitosan stabilized the immersion solution at around pH 7.2. All initial pH values were decreased during storage and then slowly increased as storage time was increased. The turbidities in all treatments were increased during storage, but the addition of 0.5% degraded chitosan showed the lowest change, compared to other treatments, showing that the water-soluble degraded chitosan has a good antimicrobial effect and has a potential use to extend the shelf-life of tofu product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.256-262
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• 2003

In order to design and develop a product that can treat the fatty liver, natural complex food with all natural ingredients was developed and supplemented to rats with high fat diet to induce fatty liver. As a result, when the amount of natural complex food was increased in diet of subjects, the activities of the blood serum AST, ALT, ALP, 3-GT and LDH were decreased. The total protein concentration levels of the 30% and the 50% natural complex food groups did not show changes in respect to the control group, but the 100% natural complex food groups showed significant decrease (p<0.05). Likewise, the amount of blood serum albumin in the 30% and the 50% natural complex food groups did not show improvement, but the 100% natural complex food did showed significant changes (p<0.05). The amount of blood serum triglyceride decreased as the amount of natural complex food was increased. In order to investigate the appearances of the accumulated fat in the liver, the animals were dissected. Livers of the control group (no natural complex food) were appeared as a white color, which means serious fat accumulation. However, all the natural complex food groups (30,50 and 100% natural complex food) showed noticeable decrease of fat content. Even the histology showed that livers of the control group had expansion of the fat, but a11 the natural complex food groups had e decreased as the contents and continued to show destroyed fatty cells. By observing the biological numeric data, the physical appearance and the history of the fatty liver, it is highly expected that natural complex food is very effective in treating the liver damaged -by the to fat and the cholesterol.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.447-459
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• 2009

This study is intended to provide basic date for the efficient management of Pinus densiflora community by analyzing ecological characteristics of Pinus densiflora inhabiting Byeonsanbando National Park. According to investigations, P. densiflora community and P. densiflora-Quercus community are widely distributed, occupying 40.3% of the total area. 21 sites ($400m^2$per site) are selected for TWINSPAN analysis, and the result indicates that the whole community of P. densiflora and P. densiflora-Quercus can be classified into 8 types, and the age of P. densiflora is 40-50 years, which is similar to that of deciduous broad-leaved trees. The 8 community types are: P. densiflora community which competes with Quercus variabilis; P. densiflora community in which Fraxinus sieboldiana and Quercus serrata grow in the understory layer; P. densifloa community in which Q. serrata grow in the understory layer and Smilax china var. microphylla in the shrub layer respectively; P. densifloa community in which P. densiflora and F. sieboldiana grow in the understory layer; P. densiflora community which competes with Q. serrata and Carpinus tschonoskii; P. densiflora community which competes with Q. variabilis and Q. serrata; P. densiflora community in which Prunus sargentii grow; P. densiflora community in which Abies holophylla grow. P. densiflora community which competes with Q. variablis and C. tschonoskii seems to be in a stage of succession to deciduous broad-leaved community. The analysis indicates that Shannon diversity index is 0.2756-1.3879. It also indicates that there is a negative correlation between P. densiflora and Q. variabilis and C. tschonoskii; there is a positive correlation between P. densiflora and F. sieboldiana and Rhododendron schlippenbachii. These investigations show that the transformation of vegetation is already under way. There is a possibility that ecological succession can take place in 30.4% of the total area from P. densiflora to Quercus and deciduous broad - leaved trees. Therefore, it is recommended that the preservation and maintenance of P. densiflora be implemented by taking control of competing species which undermine the stability of P. densiflora forest community.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.103-107
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• 2004

This study was carried out to investigate the growth of pathogenic germ in fermented pork with Korean traditional seasonings. The samples, outside muscle of pork ham were cut by the shape of cube (7${\times}$12${\times}$2cm) and seasoned with five Korean traditional seasonings such as garlic paste (Tl), pickled Kimchi (T2), pickled Kimchi juice (T3), soybean paste (T4), red pepper paste (T5). The rate of meat to seasonings was same. The seasoned samples were fermented at -1${\pm}$1$^{\circ}C$ for 28 days. Microbial pathogens such as Escherichia coli O157, Listeria monocytogenes, Salmonella enteritidis were not detected in all paste and samples. When 1.5${\times}$l0$^3$ CFU/$\textrm{cm}^2$ of Escherichia coli O157 was inoculated, the numbers were slightly increased to 10$^3$-10$^4$ CFU/$\textrm{cm}^2$ at 3 days and gradually decreased to the level of inoculation at 18 days in all samples. In the inoculation with Listeria monocytogenes (8${\times}$l0$^4$ CFU/$\textrm{cm}^2$), the numbers were below 10$^3$ CFU/$\textrm{cm}^2$ during 28 days in T3 and T4, while they were increased to 10$\^$6/ CFU/$\textrm{cm}^2$ in Tl and T2 at 3 and 13 days respectively, and decreased to 10$^4$ CFU/$\textrm{cm}^2$. In the inoculation with Salmonella enteritidis (3${\times}$l0$^4$ CFU/$\textrm{cm}^2$), the numbers increased to 10$\^$5/ CFU/$\textrm{cm}^2$ at 18 days, but they were rapidly decreased to the level of initial inoculation at 23 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.459-464
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• 2017

Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

• Tuberculosis and Respiratory Diseases
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• v.63 no.2
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• pp.128-138
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• 2007

Backgrounds: Mutations of katG and inhA (ORF and promoter) are known to be related to isoniazid (INH) resistance of Mycobacterium tuberculosis. Because reports on these mutations in Korean isolates are limited (i.e. only the frequency of katG codon 463 was evaluated.), we tried to know the kinds of mutations of two genes and their frequencies in INH resistant Korean M. tuberculosis strains. Methods: PCR was performed to amplify katG (2,223 bp), inhA ORF (-77~897, 975 bp), and inhA promoter (-168~80, 248 bp) from 29 multidrug resistant M. tuberculosis (MDR-TB) DNAs prepared by bead beater-phenol method. Their sequences were determined and analyzed by ABI PRISM 3730 XL Analyzer and MegAlign package program, respectively. Results: All of the isolates had more than one mutation in katG or inhA gene. Twenty seven (93%) of 29 tested strains had katG mutations, which suggests that katG is a critical gene determining INH resistance of M. tuberculosis. Amino acid substitutions, such as Arg463Leu and Ser315Thr, due to point mutations of the katG were the most frequent (62.1% and 55.2%) mutations. In addition, deletion of the katG gene was frequently observed (17.2%). Analyzed Korean MDR-TB isolates also had variable inhA mutations. Point mutation of inhA promoter region, such as -15 ($C{\rightarrow}T$) was frequently found. Substitution of amino acid (Lsy8Asn) due to point mutation ($AAA{\rightarrow}AAC$) of inhA ORF was found in 1 isolate. Interestingly, 14 point mutated types that were not previously reported were newly found. While four types resulted in amino acid change, the others were silent mutations. Conclusions: Although it is not clear that the relationship of these newly found mutations with INH resistance, they show marked diversity in Korean MDR-TB strains. It also suggests their feasibility as a molecular target to supplement determining the INH resistance of clinical isolates because of the possible existence of low-level INH resistant strains.