• Journal of Korean Society for Atmospheric Environment
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• v.32 no.4
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• pp.422-434
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• 2016

This study was conducted to understand roles of $NO_x(=NO+NO_2)$ on high $O_3$ episodes at an urban monitoring station in Seoul. Concentrations of NO, $NO_2$, $NO_y$ and $O_3$ were measured intensively at KIST monitoring station which located at urban center in Seoul metropolitan area during May 18~June 13, 2015. Sampling period was planed because high $O_3$ and PM occurred frequently during from late spring to early summer months in Seoul. The experimental site locates in NW from center of Seoul and is surrounded by residential area. Belt highway of the city runs from north to west side nearby experimental site. Vehicle exhaust emissions due to heavy traffic influenced $NO_x$ concentration at the site during northwesterly wind. Specific $NO_2$ concentration was measured by Blue Light photolytic converter, and it was compared to $NO_2$ concentration measured by molybedenum converter. $[NO_2]_{phtolysis}$ was usually lower than $[NO_2]_{molybedenum}$ during the experiment period; however their diurnal variations were very similar. The linear relationship between these $NO_2$ concentrations was found to be $[NO_2]_{phtolysis}$=0.64 $[NO_2]_{molybedenum}$ - 2.6, $r^2$=0.83 during May 16~8, 2015. The difference between $NO_2$ by molybdenum converter and by photolytic converter (${\Delta}NO_2=[NO_2]_{molybedenum}-[NO_2]_{phtolysis}$) accounted for residual $NO_y$ which can represent $NO_z$ (=$NO_y-NO_x$). $O_3$ concentration showed typical daily trend which has maximum at late afternoon and minimum during the night. $O_3$ increased at a rate of 7 ppb/hr since 8 am. and reached the maximum concentration (~80 ppb) at 3 pm.. The diurnal pattern of $O_3$ was inversely related with that of $NO_2$, suggesting that the formation of $O_3$ was the result of photochemical activity of $NO_2$.

• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1271-1279
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• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.525-529
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• 2009

Cytolethal distending toxins (CDTs) represent an emerging family of newly described bacterial products that are produced by a number of pathogens. The genes encoding these toxins have been identified as a cluster of three adjacent genes, cdtA, cdtB, and cdtC, plus 5 cdt genetic variants, designated as cdt-I, cdt-II, cdt-III, cdt-IV, and cdt-V, have been identified to date. In this study, a general multiplex PCR system designed to detect Escherichia coli cdts was applied to investigate the presence of cdt genes among isolates. As a result, among 366 E. coli strains, 2.7% were found to carry the cdtB gene. In addition, the use of type-specific primers revealed the presence of cdt-I, cdtIV, and cdt-V types of the cdt gene, yet no cdt-II or cdt-III strains. The presence of other virulence genes (stxl, stx2, eae, bfp, espA, espB, and espD) was also investigated using a PCR assay. Among the 10 cdtB gene-positive strains, 8 were identified as COT-producing typical enteropathogenic E. coli (EPEC) strains ($eae^+$, $bfp^+$), whereas 2 were identified as CDT-producing atypical EPEC strains ($eae^+$, $bfp^-$). When comparing the cytotoxic activity of the CDT-producing typical and atypical EPEC strains, the CDT-producing atypical EPEC strains appeared to be less toxic than the CDT-producing typical EPEC strains.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1170-1178
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• 2008

The cyclopentenone prostaglandins (cyPGs) prostaglandin $A_1$ ($PGA_1$) and 15-deoxy-${\Delta}^{12,14}$-prostaglandin $J_2$ (15d-$PGJ_2$) have been reported to exhibit antiinflammatory activity in activated monocytes/macrophages. However, the effects of these two cyPGs on the expression of cytokine genes may differ. In this study, we investigated the mechanism of action of $PGA_1$ in lipopolysaccharide (LPS)-induced expression of inter leu kin (IL)-10 mRNA in mouse peritoneal macrophages. 15d-$PGJ_2$ inhibited expression of LPS-induced IL-10, whereas $PGA_1$ increased LPS-induced IL-10 expression. This synergistic effect of $PGA_1$ on LPS-induced IL-10 expression reached a maximum as early as 2 h after simultaneous $PGA_1$ and LPS treatment ($PGA_1$/LPS), and did not require new protein synthesis. The synergistic effect of $PGA_1$ was inhibited by GW9662, a specific peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ antagonist, and Bay-11-7082, a NF-${\kappa}B$ inhibitor. The extracellular signal-regulated kinases (ERK) inhibitor PD98059 increased the expression of $PGA_1$/LPS-induced IL-10 mRNA, rather than inhibiting the IL-10 expression. Moreover, $PGA_1$ inhibited LPS-induced ERK phosphorylation. The synergistic effect of $PGA_1$ on LPS-induced IL-10 mRNA and protein production was inhibited by p38 inhibitor PD169316, and $PGA_1$ increased LPS-induced p38 phosphorylation. In the case of stress-activated protein kinase/c-Jun $NH_2$-terminal kinase (SAPK/JNK), the SAPK/JNK inhibitor SP600125 did not inhibit IL-10 mRNA synthesis but inhibited the production of IL-10 protein remarkably. These results suggest that the synergistic effect of $PGA_1$ on LPS-induced IL-10 expression is NF-${\kappa}B$-dependent and mediated by mitogen-activated protein (MAP) kinases, p38, and SAPK/JNK signaling pathways, and also associated with the $PPAR{\gamma}$ pathway. Our data may provide more insight into the diverse mechanisms of $PGA_1$ effects on the expression of cytokine genes.

• Korean Journal of Psychosomatic Medicine
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• v.25 no.1
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• pp.3-11
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• 2017

Objectives : The aim of this study was to draw attention toward so called 'behavioral variant frontotemporal dementia(bvFTD) phenocopy syndrome', which is difficult to discriminate with the primary psychiatric disorders, showing poor response to conventional therapeutic drugs, leading to higher risk to misdiagnoses and legal problems. Furthermore, the author insisted that our interest and study on them must be continued. Methods : English articles published during 2000 thru 2016 had been searched by internet with the combination of words such as 'frontotemporal', 'phenocopy' and 'behavioral', and reviewed. Besides, two clinical vignettes were described. Results : Precise diagnosis is important because patients' behavioral symptoms can influence on their families and community. However, disease-modifying treatment for bvFTD are not developed until now, and recent therapeutic drugs are only good for specific symptoms, while deterioration progresses in spite of proper psychiatric management. The possible bvFTD patients are not progressed into probable bvFTD clinically, showing no decline of cogntive and social function, no decrease of activity function, longer survival time, and normal neuroimaging for several years. Conclusions : Rather than expected, there are much more patients having clinical symptoms, course and diagnostic findings including neuroimaging, which are atypical to classical frontotemporal dementia and primary psychiatric disorders. If our knowledge and discriminating ability is improved, discovery rate of that cases will be increased. However, the identity of these atypical features are not clarified until now, it must be further actively investigated.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.23-28
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• 2017

Amomum tsao-ko used as a traditional oriental herbal medicine, is indigenous to several Asia countries. In this study, we investigated anti-obesity activity of the ethanol extract of Amomum Taso-ko (A. tsao-ko). The ethanol extract of A. tsao-ko inhibited adipocyte differentiation using Oil Red O assay in 3T3-L1 cells. Inhibitory effect of the ethanol extract of A. tsao-ko on adipogenesis was modulated by down-regulation adipogenic transcriptional factor such as peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), CCAAT-enhancer-binding protein ${\alpha}$ ($C/EBP{\alpha}$) and suppressed expression of fatty acid synthase, aP2, and resistin. We demonstrated that A. tsao-ko significantly inhibited adipogenesis and reduced $PPAR{\gamma}$ and $C/EBP{\alpha}$ expression in a dose-dependent manner. These results suggest that A. tsao-ko has an anti-obesity effect by inhibition of adipogenic transcription factor and adipocyte-specific genes in 3T3-L1 cells.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.326-332
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• 2015

Greenhouse-gas emission factors are widely used to estimate emissions arising from a defined unit of a specific activity. Such estimates are used both for international reporting to the United Nations Framework Convention on Climate Change (UNFCCC) and for a myriad of national and subnational reporting purposes. The Intergovernmental Panel on Climate Change (IPCC) provides a methodology for national and sub-national estimation of known greenhouse gas emissions including $N_2O$ for each sector from which the emissions arise. The objective of this study was to develop an emission factor to estimate the direct $N_2O$ emission from an agricultural field cultivated with Chinese cabbage during spring season in 2010-2012. An estimated emission factor of $N_2O$ calculated over three years from field experiment accounting for cumulative $N_2O$ emission, nitrogen fertilization rate, and background $N_2O$ emission was $0.0056{\pm}0.00254$ (95% CI) Kg $N_2O-N/kg$ N. More extensive studies are needed to develop $N_2O$ emission factors for other upland crops in various regions of Korea because $N_2O$ emission is influenced by many factors including climate characteristics, soil properties agricultural practices and crop species.

• Quality Improvement in Health Care
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• v.8 no.2
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• pp.218-231
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• 2001

Background : The purpose of this study was to investigate the understanding and the attitude of Korean hospital CEOs toward the healthcare quality improvement. Methods : A mailed questionnaire survey to the CEOs of hospitals with 400 beds or more was conducted between September 15 and October 30, 2000. Of the 108 hospitals eligible for the study, 58 participated, yielding a response rate of 54 percent. Result : The hospital CEOs have expressed that their hospital management was arduous job, and they had been pressured by increasing competitions among healthcare providers. They indicated that the low fees of health insurance made their hospital management difficult. The results also indicated that there was general consensus that the improvement of service quality was important in encouraging their organizations, but the investment of manpower and equipment ranked higher than the improvement of service quality. The majority of the CEOs have good understanding about quality improvement activities. However the facts that in general QI must be focused at the process of services and customer satisfaction, meanwhile quality improvement activities are helpful for the organizational productivity embarrassed them. The hospital CEOs responded that there were successful changes in terms of quality of care, patient satisfaction, and process efficiency after QI activities, but no increase in patient number and profit. Lack of understanding to QI activities and limited budget seem to attribute unsatisfactory outcomes. Conclusion : The majority of Korean hospital CEOs have a good understanding and attitude about QI activities. As mentioned in the result, despite of several limitations, several facts regarding the CEOs of hospital in Korean can be elucidated. (1) The general cognition of the QI project is relatively high, and it is accepted with positive concern, (2) the priority of the QI project, however, is not set higher than other projects and (3) the specific concepts of the actual QI project such as customer (patient)-focused work driving, the recognition of the work accomplishment, and the importance of rewards have not sufficiently understood.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.169-173
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• 2001

Objectives: The p53 tumor suppressor gene encodes a nuclear transcription factor that is critical regulator of cell growth and proliferation through its action in cell-cycle checkpoint control. The wide variety of stressful stmuli which include DNA damage, hypoxia, heat shock, metabolic changes activate the p53 protein, which in turn drives a series of events that culminate either in cell cycle arrest or apoptosis. Mutations of the p53 gene is the most common genetic alteration in human cancer. This gene is altered in approximately 40-60% of head and neck cancers. Whereas the wild-type form of the p53 protein plays a central role in cell-cycle control in response to DNA damage, most of the mutant forms are unable to do so. The high levels of p53 protein expression in tissues are related to the increased cellular proliferative activity and may be associated with the poor clinical outcome. To determine whether the expression of the p53 protein has prognostic significance and is associated with patterns of treatment failure in head and neck squamous cell carcinoma (HNSCC), We analyzed p53 overexpression in 40 cases of HNSCC. Materials and Methods: Immunohistochemical analysis with a monoclonal antibody (DO7) specific for p53 protein was used to detect expression of the protein in formalin-fixed, paraffin-embedded tumor samples from 40 HNSCC. We evaluated p53 protein expression and analyzed the relationship between the p53 overexpression and age, sex, primary tumor site, stage, survival rate, recurrence. All reported P values resulted from two-sided statistical tests. Results: Overexpression of p53 was detected in 20 cases(50%) among 40 cases of HNSCC. The p53 overexpression was not associated with age, sex, primary tumor site, stage, recurrence and survival rate. Conclusions: In our results, p53 was not significant prognostic factor in HNSCC. Based on many previous studies, It is evident that p53 has a certain role in tumorigenesis of HNSCC. So, the further study is needed to evaluate the prognostic significance of p53 in HNSCC.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.68-72
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• 2002

To obtain a yeast mutant with high RNA content and high growth rate, Saccharomyces cerevisiae MTY62 was mutated with ethylmethane sulfonate. Among the selected mutants that were sensitive to the high concentration of KCl, M40-10 strain was finally selected due to its rapid cell growth and high RNA content in the tube and baffled-flask cultures. In the batch culture of M40-10 mutant, the maximum specific growth rate ($\mu_{max}$) of $0.38 h^{-1}$ , RNA concentration of 3210 mg-RNA/1, and RNA content of 183 mg-RNA/g-DCW were obtained, which were 23%, 15%, and 12% increased levels, respectively, compared to those of MTY62 parent strain. The intermittent fed-batch culture of M40-10 strain resulted in the maximum cell concentration of 35.6 g-DCW/1, RNA concentration of 5677 mg/1, and RNA content of 160 mg-RNA/g-DCW. Through the constant fed-batch culture, the maximum cell concentration of 46.4 g-DCW/1, RNA concentration of 6270 mg-RNA/1, and RNA content of 135 mg-RNA/g-DCW were obtained. At the 20 h culture time in the fed-batch cultures of M40-10 strain, the cell and RNA concentrations were increased by 30% and 10%, respectively, over the parent strain MTY62. In addition, it was also found that the accumulated RNA within the mutant cell was not degraded until the end of fed-batch cultivation, indicating that the M40-10 cell is a mutant with weak acidic RNase activity.y.