• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.642-648
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• 2020

In this study, we investigated the effects of linoleic acid (LA) treatment on Brucella abortus infection in professional phagocyte RAW264.7 cells, particularly during the pathogen's invasion and intracellular growth in these cells, as well as in murine model BALB/c mice focusing on bacterial splenic proliferation and immunoregulatory activities. LA inhibited the growth of Brucella in a dose- and time-dependent manner. The ability of the pathogen to enter the phagocytes was inhibited as was its survival within these cells. This was accompanied by increased nitrite accumulation in these cells at 24 h post-infection. The concentration of LA used in the present study did not affect the total body weight or liver function of the mice. During Brucella infection, the total splenic weight of these animals was not changed; rather, resistance to bacterial proliferation was enhanced in the spleen. Furthermore, mice treated with LA displayed elevated levels of IL-12 and IFN-γ but reduced levels of IL-10 during infection. The findings in this study showed the regulatory role of LA against B. abortus infection suggesting its potential use in designing intervention strategy for brucellosis.

• 한국발생생물학회지:발생과생식
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• 제22권2호
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• pp.133-142
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• 2018

Patients with type II diabetes mellitus are more susceptible to colorectal cancer (CRC) incidence than non-diabetics. The anti-diabetic drug metformin is most commonly prescribed for the treatment of this disease and has recently shown antitumor effect in preclinical studies. The aberrant mutational activation in the components of RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathway is very frequently observed in CRC. We previously reported that metformin inhibits the phosphorylation of ERK and BEZ235, a dual inhibitor of PI3K and mTOR, has anti-tumor activity against HCT15 CRC cells harboring mutations of KRAS and PIK3CA. Therefore, we hypothesized that simultaneous inhibition of two pathways by combining metformin with BEZ235 could be more effective in the suppression of proliferation than single agent treatment in HCT15 CRC cells. Here, we investigated the combinatory effect of metformin and BEZ235 on the cell survival in HCT15 CRC cells. Our study shows that both of the two signaling pathways can be blocked by this combinational strategy: metformin suppressed both pathways by inhibiting the phosphorylation of ERK, 4E-BP1 and S6, and BEZ235 suppressed PI3K/AKT/mTOR pathway by reducing the phosphorylation of 4E-BP1 and S6. This combination treatment synergistically reduced cell viability. The combination index (CI) values ranged from 0.44 to 0.88, indicating synergism for the combination. These results offer a preclinical rationale for the potential therapeutic option for the treatment of CRC.

• Molecules and Cells
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• 제38권5호
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• pp.416-425
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• 2015

NF-E2-related factor 2 (Nrf2), a basic leucine zipper transcription factor, has recently received a great deal of attention as an important molecule that enhances antioxidative defenses and induces resistance to chemotherapy or radiotherapy. In this study, we investigated the apoptosis-inducing and Nrf2- upregulating effects of quercetin on malignant mesothelioma (MM) MSTO-211H and H2452 cells. Quercetin treatment inhibited cell growth and led to upregulation of Nrf2 at both the mRNA and protein levels without altering the ubiquitination and extending the half-life of the Nrf2 protein. Following treatment with quercetin, analyses of the nuclear level of Nrf2, Nrf2 antioxidant response element-binding assay, Nrf2 promoter-luc assay, and RT-PCR toward the Nrf2-regulated gene, heme oxygenase-1, demonstrated that the induced Nrf2 is transcriptionally active. Knockdown of Nrf2 expression with siRNA enhanced cytotoxicity due to the induction of apoptosis, as evidenced by an increase in the level of proapoptotic Bax, a decrease in the level of antiapoptotic Bcl-2 with enhanced cleavage of caspase-3 and PARP proteins, the appearance of a sub-$G_0/G_1$ peak in the flow cytometric assay, and increased percentage of apoptotic propensities in the annexin V binding assay. Effective reversal of apoptosis was observed following pretreatment with the pan-caspase inhibitor Z-VAD. Moreover, Nrf2 knockdown exhibited increased sensitivity to the anticancer drug, cisplatin, presumably by potentiating the oxidative stress induced by cisplatin. Collectively, our data demonstrate the importance of Nrf2 in cytoprotection, survival, and drug resistance with implications for the potential significance of targeting Nrf2 as a promising strategy for overcoming resistance to chemotherapeutics in MM.

• 로봇학회논문지
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• 제8권2호
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• pp.136-142
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• 2013

In nature, many small insects are using jumping as a survival strategy. Among them, fleas jump in a unique method. They use an elastomer, 'Resilin', an extensor muscle and a trigger muscle. By contracting the extensor muscle, the elastic energy, that makes a flea to jump, is stored in the resilin. After storing energy, the trigger muscle begins contracting and pulling the extensor muscle. When the extensor muscle crosses the rotational joint, direction of torque generated from the extensor muscle reverses, 'torque reversal mechanism'. Simultaneously, the elastic energy stored in the resilin releases rapidly and is converted into the kinetic energy. It makes a flea to jump 150 times its body length. In this paper, miniaturized jumping robot using flea-inspired catapult mechanism is presented. This mechanism is based on the 4-bar linkage and the reversal joint and is actuated by Shape Memory Alloy (SMA) coiled springs describing the flea's muscle. The robot prototype is fabricated by SCM process using glass fiber prepregs and a sheet of polyimide film. The prototype is 20mm link length, 34mm width and 2.0g weight and can jump 103cm.

• 한국의류학회지
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• 제40권4호
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• pp.763-774
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• 2016

Companies have recently become interested in the importance of long-term relationships with customers because business-based marketing ideas of the past have evolved into long-term relationship-based marketing. Establishing a relationship with customers to a company is not a simple method to form a market of consumers and provider; it is now understood as an important factor directly connected to the survival of a company. This study is to help Korean fashion brands in China build an efficient strategy for sales promotion and loyal customers through the analysis of the effect of familiarity with Korean fashion brands on satisfaction and brand loyalty in a rapidly growing Chinese fashion market. An online questionnaire covering Korean fashion brands in China was completed by 377 Chinese male and female customers aged 20 to 39 years old from March 20 to March 27, 2014. Data analysis was performed by factor analysis and path analysis using SPSS 20.0 and AMOS. Both direct experiences and indirect experiences influenced brand familiarity. It showed that brand familiarity had a significant direct effect and an indirect effect through satisfaction on brand loyalty. A competitive advantage in the present Chinese fashion market requires that loyalty builds and that brand loyalty increases by creating a long-term relationship with customers when familiarity about the brand is induced.

• 한국건설관리학회논문집
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• 제8권6호
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• pp.197-206
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• 2007

지금은 '개발기간 단축, 고품질'을 위한 종합적인 대처를 요하는 시대이다. 제품은 점차 복잡화되고 그 종류 또한 다양화되어 가는 반면 제품의 생애주기(Life Cycle)는 축소되고 있다. 이러한 무한경쟁시대에 있어 적자생존의 확실한 해답은 기업스스로 개발기간 및 납기를 단축시키고 제품개발에 앞장서며, 제품의 생애주기 원가를 절감시켜 성능과 가치 양면을 동시에 고객에게 감동 줄 수 있는 품질을 확보하는 데에 있다. 이와 같은 측면에서 프로세스의 각 공정을 동시 병행적으로 개발하는 '동시공학'은 건설에 있어 중요한 개념으로 인식되고 있다. 본 연구는 동시공학을 성공적으로 적용하기 위하여 문헌 및 여러 가지 사례를 조사, 분석하고 그것들이 각 프로세스에 미치는 영향을 시뮬레이션 실행을 거쳐 의사결정 모델로 제시한다.

• Journal of Gastric Cancer
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• 제14권1호
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• pp.39-46
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• 2014

Purpose: According to current guidelines, perioperative chemotherapy is an integral part of the treatment strategy for advanced gastric cancer. Randomized controlled studies have been conducted in order to determine whether perioperative chemotherapy leads to improved R0 resection rates, fewer recurrences, and prolonged survival. The aim of our project was to critically appraise three major studies to establish whether perioperative chemotherapy for advanced, potentially resectable gastric cancer can be recommended on the basis of their findings. Materials and Methods: We analyzed the validity of the three most important studies (MAGIC, ACCORD, and EORTC) using a standardized questionnaire. Each study was evaluated for the study design, patient selection, randomization, changes in protocol, participating clinics, preoperative staging, chemotherapy, homogeneity of subjects, surgical quality, analysis of the results, and recruitment period. Results: All three studies had serious shortcomings with respect to patient selection, homogeneity of subjects, changes in protocol, surgical quality, and analysis of the results. The protocols of the MAGIC and ACCORD-studies were changed during the study period because of insufficient recruitment, such that carcinomas of the lower esophagus and the stomach were examined collectively. In neither the MAGIC study nor the ACCORD study did patients undergo adequate lymphadenectomy, and only about half of the patients in the chemotherapy group could undergo the treatment specified in the protocol. The EORTC study had insufficient statistical power. Conclusions: We concluded that none of the three studies was sufficiently robust to justify an unrestrained recommendation for perioperative chemotherapy in cases of advanced gastric cancer.

• Tuberculosis and Respiratory Diseases
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• 제72권4호
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• pp.343-351
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• 2012

Background: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit this pathway are currently under development for lung cancer treatment. In the present study, we have tested whether dual inhibition of PI3K/Akt/mTOR signaling can lead to enahnced antitumor effects. We have also examined the role of autophagy during this process. Methods: We analyzed the combination effect of the mTOR inhibitor, temsirolimus, and the Akt inhibitor, GSK690693, on the survival of NCI-H460 and A549 non-small cell lung cancer cells. Cell proliferation was determined by MTT assay and apoptosis induction was evaluated by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Autophagy induction was also evaluated by acridine orange staining. Changes of apoptosis or autophagy-related proteins were evaluated by western blot analysis. Results: Combination treatment with temsirolimus and GSK690693 caused synergistically increased cell death in NCI-H460 and A549 cells. This was attributable to increased induction of apoptosis. Caspase 3 activation and poly(ADP-ribose) polymerase cleavage accompanied these findings. Autophagy also increased and inhibition of autophagy resulted in increased cell death, suggesting its cytoprotective role during this process. Conclusion: Taken together, our results suggest that the combination of temsirolimus and GSK690693 could be a novel strategy for lung cancer therapy. Inhibition of autophagy could also be a promising method of enhancing the combination effect of these drugs.

• Journal of Ginseng Research
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• 제36권4호
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• pp.396-402
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• 2012

Vaccination is the main strategy for preventing influenza infection. However, vaccine efficacy is influenced by several factors, including age and health status. The efficacy of the influenza vaccine is much lower (17% to 53%) in individuals over 65 yr of age compared with young adults (70% to 90%). Therefore, increasing vaccine efficacy remains a challenge for the influenza vaccine field. In this study, we investigated the impact of supplementing vaccination with the dietary intake of Korean red ginseng (RG) extract and RG saponin. Mice were immunized two times intranasally with inactivated influenza A (H1N1) virus. Mice received RG extract or RG saponin orally for 14 d prior to the primary immunization. After the primary immunization, mice continued to receive RG extract or RG saponin until the secondary immunization. Mice vaccinated in combination with dietary intake of RG extract and RG saponin showed elevated serum anti-influenza A virus IgG titers and improved survival rates in lethal influenza A virus infection: 56% and 63% of mice receiving RG extract or RG saponin survived, respectively, while 38% of mice that only received the vaccine survived. Moreover, mice receiving RG extract supplementation recovered their body weight more quickly than those not receiving RG extract supplementation. We propose that the dietary intake of RG extract and RG saponin enhances the vaccine-induced immune response and aids in providing protection against influenza virus infection.

• Journal of Ginseng Research
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• 제42권3호
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• pp.343-351
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• 2018

Background: Red ginseng is a popularly used traditional medicine with antiaging effects in Asian countries. The present study aimed to explore the changes in protein expression underlying the mechanisms of life span extension and antiaging caused by red ginseng extract (RGE) in Drosophila melanogaster. Methods: A proteomic approach of two-dimensional polyacrylamide gel electrophoresis (2-DE) was used to identify the differential abundance of possible target proteins of RGE in D. melanogaster. The reliability of the 2-DE results was confirmed via Western blotting to measure the expression levels of selected proteins. Proteins altered at the expression level after RGE treatment (1 mg/mL) were identified by matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry and by searching against the National Center for Biotechnology nonredundant and Uniprot protein databases. The differentially expressed proteins were analyzed using bioinformatics methods. Results: The average survival life span of D. melanogaster was significantly extended by 12.60% with RGE treatment (1 mg/mL) compared to untreated flies. This followed increased superoxide dismutase level and decreased methane dicarboxylic aldehyde content. Based on the searching strategy, 23 differentially expressed proteins were identified (16 up-regulated and 7 down-regulated) in the RGE-treated D. melanogaster. Transduction pathways were identified using the Kyoto Encyclopedia of Genes and Genomes database, and included the hippo and oxidative phosphorylation pathways that play important roles in life span extension and antiaging process of D. melanogaster. Conclusion: Treatment with RGE in D. melanogaster demonstrated that mechanisms of life span extension and antiaging are regulated by multiple factors and complicated signal pathways.