• Clinical and Experimental Pediatrics
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• 제52권8호
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• pp.862-868
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• 2009

Since its identification in April 2009, a swine-origin H1N1 influenza A virus (S-OIV) which is a reassortment of gene segments from both North American triple-reassortant and Eurasian swine influenza has been widely spread among humans in unexpected rapidity. To date, each gene segment of the 2009 influenza A (H1N1) outbreak viruses have shown high (99.9%) neucleotide sequence identity. As of July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most confirmed cases of S-OIV infection have been characterized by self-limited, uncomplicated febrile respiratory illness and 38% of cases have also included vomiting or diarrhea. Standard plus droplet precautions should be adhered to at all times. Tests on S-OIV have indicated that current new H1N1 viruses are sensitive to neuraminidase inhibitors (oseltamivir). However, current less virulent S-OIV may evolve into a pathogenic strain or acquire antiviral resistance, potentially with more severe clinical consequences. Efforts to control these outbreaks would be based on our understanding of novel S-OIV and previous influenza pandemics.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.37-41
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• 2009

Previous studies have demonstrated that Shewanella decolorationis S12 can grow on the azo compound amaranth as the sole electron acceptor. Thus, to explore the mechanism of energy generation in this metabolism, membranous vesicles (MVs) were prepared and the mechanism of energy generation was investigated. The membrane, which was fragmentized during preparation, automatically formed vesicles ranging from 37.5-112.5 nm in diameter under electron micrograph observation. Energy was conserved when coupling the azoreduction by the MVs of an azo compound or Fe(III) as the sole electron acceptor with $H_2$, formate, or lactate as the electron donor. The amaranth reduction by the vesicles was found to be inhibited by specific respiratory inhibitors, including $Cu^{2+}$ ions, dicumarol, stigmatellin, and metyrapone, indicating that the azoreduction was indeed a respiration reaction. This finding was further confirmed by the fact that the ATP synthesis was repressed by the ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD). Therefore, this study offers solid evidence of a mechanism of microbial dissimilatory azoreduction on a subcell level.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.14-14
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• 2020

In December 2019, the COVID-19 epidemic was discovered in Wuhan, China, and since has disseminated around the world impacting human health for millions. Herein, in-silico drug discovery approaches were utilized to identify potential candidates as Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (M^pro) inhibitors. We investigated several databases including natural and natural-like products (>100,000 molecules), DrugBank database (10,036 drugs), major metabolites isolated from daily used spices (32 molecules), and current clinical drug candidates for the treatment of COVID-19 (18 drugs). All tested compounds were prepared and screened using molecular docking techniques. Based on the calculated docking scores, the top ones from each project under investigation were selected and subjected to molecular dynamics (MD) simulations followed by molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. Combined long MD simulations and MM-GBSA calculations revealed the potent compounds with prospective binding affinities against M^pro. Structural and energetic analyses over the simulated time demonstrated the high stabilities of the selected compounds. Our results showed that 4-bis([1,3]dioxolo)pyran-5-carboxamide derivatives (natural and natural-like products database), DB02388 and Cobicistat (DB09065) (DrugBank database), salvianolic acid A (spices secondary metabolites) and TMC-310911 (clinical-trial drugs database) exhibited high binding affinities with SARS-CoV-2 M^pro. In conclusion, these compounds are up-and-coming anti-COVID-19 drug candidates that warrant further detailed in vitro and in vivo experimental estimations.

• The Korean Journal of Physiology and Pharmacology
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• 제26권4호
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• pp.239-253
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• 2022

Epithelial-mesenchymal transition (EMT) is known to be involved in airway remodeling and fibrosis of bronchial asthma. However, the molecular mechanisms leading to EMT have yet to be fully clarified. The current study was designed to reveal the potential mechanism of microRNA-21 (miR-21) and poly (ADP-ribose) polymerase-1 (PARP-1) affecting EMT through the PI3K/AKT signaling pathway. Human bronchial epithelial cells (16HBE cells) were transfected with miR-21 mimics/inhibitors and PARP-1 plasmid/small interfering RNA (siRNA). A dual luciferase reporter assay and biotin-labeled RNA pull-down experiments were conducted to verify the targeting relationship between miR-21 mimics and PARP-1. The migration ability of 16HBE cells was evaluated by Transwell assay. Quantitative real-time polymerase chain reaction and Western blotting experiments were applied to determine the expression of Snail, ZEB1, E-cadherin, N-cadherin, Vimentin, and PARP-1. The effects of the PI3K inhibitor LY294002 on the migration of 16HBE cells and EMT were investigated. Overexpression of miR-21 mimics induced migration and EMT of 16HBE cells, which was significantly inhibited by overexpression of PARP-1. Our findings showed that PARP-1 was a direct target of miR-21, and that miR-21 targeted PARP-1 to promote migration and EMT of 16HBE cells through the PI3K/AKT signaling pathway. Using LY294002 to block PI3K/AKT signaling pathway resulted in a significant reduction in the migration and EMT of 16HBE cells. These results suggest that miR-21 promotes EMT and migration of HBE cells by targeting PARP-1. Additionally, the PI3K/AKT signaling pathway might be involved in this mechanism, which could indicate its usefulness as a therapeutic target for asthma.

• Tuberculosis and Respiratory Diseases
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• 제65권1호
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• pp.7-14
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• 2008

연구배경: 잔여 흉막비후는 결핵성 흉막염 치료 후 흔히 나타날 수 있는 합병증 중의 하나이며, 이로 인해 호흡기능에 지장을 주는 경우가 있다. 이에 결핵성 흉막염 진단 시 흉수 내의 metalloproteinase (MMP)s와 tissue inhibitor of metalloproteinase (TIMP)s의 농도가 치료 후 잔여 흉막비후가 지속되는 지 예측할 수 있는 인자가 될 수 있는 지 알아보고자 하였다. 방 법: 2004년 1월부터 2005년 6월 사이에 흉수가 발견되어 입원한 환자를 대상으로 전향적 연구를 시행하였다. 진단 시 흉수의 분석을 통해 결핵성 흉막염, 부폐렴성 흉수, 악성 흉수, 여출액군으로 나누고, 환자의 혈청과 흉수에서 ELISA 방법을 이용하여 MMP-1, -2, -8, -9와 TIMP-1, -2를 측정하였다. 결핵성 흉막염의 경우 흉부엑스선검사로 항결핵제 치료 종결 시점과 마지막 추적 관찰시점에 잔여 흉막비후의 두께를 측정하여 잔여 흉막비후가 있는 군과 없는 군으로 나누었다. 결 과: 흉수가 발견되어 입원한 환자 중 제외 기준에 해당하는 환자를 제외하고 총 39명의 환자가 대상이 되었다. 이 중 결핵성 흉막염은 23명, 부폐렴성 흉수 7명, 악성 흉수 7명, 여출액 2명이었다. 결핵성 흉막염 환자 23명 중 본원에서 항결핵제 치료를 종료한 환자는 17명이었으며, 이 중 잔여 흉막비후가 없는 군은 10명(59%)이었으며, 잔여 흉막비후가 있는 군은 7명(41%)이었다. 잔여 흉막비후가 있는 군은 흉수 TIMP-1 ($41,405.9{\pm}9,737.3ng/mL$)이 잔여 흉막비후가 없는 군($29,134.9{\pm}8,801.8$)보다 의미있게 높았다(p=0.032). 치료 종료 후 평균 $8{\pm}5$개월의 추적관찰이 가능한 13명의 환자들에서, 마지막으로 촬영한 흉부 후전위 촬영에서 잔여 흉막비후가 없는 군은 11명(85%)이었고, 잔여 흉막비후가 있는 군은 2명(15%)이었다. 잔여 흉막비후가 있는 군은 흉수 TIMP-2 ($34.4{\pm}6.5ng/mL$)가 잔여 흉막비후가 없는 군($44.4{\pm}15.5$)보다 의미있게 낮았다(p=0.038). 결 론: 결핵성 흉막염의 잔여 흉막비후의 발생에 TIMP-1과 TIMP-2이 관여 될 수도 있을 것으로 추정된다.

• Tuberculosis and Respiratory Diseases
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• 제82권1호
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• pp.42-52
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• 2019

Background: Transforming growth factor ${\beta}$ (TGF-${\beta}$), retinoic acid (RA), p38 mitogen-activated protein kinase (MAPK), and MEK signaling play critical roles in cell differentiation, proliferation, and apoptosis. We investigated the effect of RA and the role of these signaling molecules on the phosphorylation of Smad2/3 (p-Smad2/3) induced by TGF-${\beta}1$. Methods: A549 epithelial cells and CCD-11Lu fibroblasts were incubated and stimulated with or without all-trans RA (ATRA) and TGF-${\beta}1$ and with MAPK or MEK inhibitors. The levels of p-Smad2/3 were analyzed by western blotting. For animal models, we studied three experimental mouse groups: control, bleomycin, and bleomycin+ATRA group. Changes in histopathology, lung injury score, and levels of TGF-${\beta}1$ and Smad3 were evaluated at 1 and 3 weeks. Results: When A549 cells were pre-stimulated with TGF-${\beta}1$ prior to RA treatment, RA completely inhibited the p-Smad2/3. However, when A549 cells were pre-treated with RA prior to TGF-${\beta}1$ stimulation, RA did not completely suppress the p-Smad2/3. When A549 cells were pre-treated with MAPK inhibitor, TGF-${\beta}1$ failed to phosphorylate Smad2/3. In fibroblasts, p38 MAPK inhibitor suppressed TGF-${\beta}1$-induced p-Smad2. In a bleomycin-induced lung injury mouse model, RA decreased the expression of TGF-${\beta}1$ and Smad3 at 1 and 3 weeks. Conclusion: RA had inhibitory effects on the phosphorylation of Smad induced by TGF-${\beta}1$ in vitro, and RA also decreased the expression of TGF-${\beta}1$ at 1 and 3 weeks in vivo. Furthermore, pre-treatment with a MAPK inhibitor showed a preventative effect on TGF-${\beta}1$/Smad phosphorylation in epithelial cells. As a result, a combination of RA and MAPK inhibitors may suppress the TGF-${\beta}1$-induced lung injury and fibrosis.

• Tuberculosis and Respiratory Diseases
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• 제54권1호
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• pp.104-113
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• 2003

연구배경 : Rhinovirus(RV)는 상기도 감염의 중요한 원인균으로, 성인에서 기관지천식의 급성악화의 주요 원인이다. RV에 의한 기도염증반응의 기전은 잘 알려져 있지 않지만 interleukin(IL)-1, IL-6, IL-8 및 RANTES 등의 사이토카인을 매개로 일어난다. 염증반응에 관여하는 사이토카인의 발현은 적어도 전사인자 NF-${\kappa}B$에 의존성이므로 이러한 가설을 검증하기 위해 인체기도상피세포에서 RV에 의한 IL-8의 분비양상과 NF-${\kappa}B$ 활성화 단계에서 차단 제로 이용되는 N-acetyl-L-cysteine(NAC), PDTC, 및 TPCK를 투여하여 IL-8의 차단정도를 연구하여 NF-${\kappa}B$의 역할을 규명하고자 하였다. 방법 : 인체 기관지상피세포(BEAS-2B)와 RV type 14(RV14)를 ATCC로부터 구입하여 RV14 스톡을 만들고 역가를 측정하였다. 자극이 없는 대조군(배지단독)과 RV14를 상피세포에 감염시킨 후(MOI=1.0) 각각에서 2, 4, 6, 12, 24, 48 시간에 배양 상층액(SN)을 얻었다. 또한 대조군, RV14 자극군, NAC, PDTC, 및 TPCK 처치와 함께 RV14 자극을 준 군에서 각각 배양 12시간에 배양 상층액을 수집했다. SN에서 효소면역측정법으로 IL-8의 농도를 측정하였다. 결과 : 1) 상피세포는 RV14 자극이 없는 상태에서 배양시간의 경과에 따라 약간의 IL-8의 생산이 있었다. 2) 상피세포에 RV14 감염 후 4시간에서부터 IL-8이 증가하여 배양 48시간까지 지속적으로 증가하였다. 3) NAC와 PDTC는 RV14에 의한 IL-8의 생산을 유의하게 감소시켰으나, TPCK는 RV에 의한 IL-8의 생산을 억제하였지만 통계학적으로 유의하지 않았다. 4) NAC와 PDTC는 RV에 의한 IL-8 생성을 용량 의존적으로 억제하였다. 결론 : 일부 항산화제가 RV에 의한 기도염증반응을 차단할 수 있는 가능성을 제시하며 추후 NF-${\kappa}B$ 활성화 경로의 차단 부위에 대한 연구가 필요할 것으로 생각한다.

• 농약과학회지
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• 제4권3호
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• pp.52-59
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• 2000

Saccharomyces cerevisiae를 이용하여 효율적인 호흡저해 스크리닝 방법을 개발하고자 실험하였다. S. cerevisiae균을 glucose 발효와 미토콘드리아 호흡이 가능한 yeast extract-peptone-dextrose (YPD) 배지와 단지 미토콘드리아 호흡만이 가능한 non-fermentable carbon source-yeast extract (NFY) 배지로 수확하였다. 96-well plate의 각 well에 균 현탁액을 분주한 다음 다양한 작용기작의 46개 살균제를 여러 가지 농도로 처리하였다. NFY배지에서의 non-fermentable carbon source로는 ethanol (NFY-E배지) 및 glycerol (NFY-G배지), lactate (NFY-L배지)를 이용하였다. 접종 후 $1{\sim}3$일 동안 배양한 다음 최소억제농도 (minimum inhibitory concentration, MIC)를 결정한 결과, 4개의 호흡억제 살균제인 azoxystrobin, kresoxim-methyl, metominostrobin, trifloxystrobin은 YPD 배지에서 균의 생육을 전혀 억제하지 못하였으나, 세가지 NFY배지에서는 높은 항균활성을 보였다. 이와는 반대로 5개의 N-trihalomethylthio계 살균제는 NFY배지보다 YPD 배지에서 높은 활성을 보였다. 그리고 11개 살균제는 두 배지 모두에서 같은 항균활성을 나타내었고, 나머지 26개의 살균제는 모든 배지에서 전혀 항균활성을 보이지 않았다. 그러므로 S. cerevisiae와 96-well plate를 이용한 호흡저해제 검정법은 신속하고 편리하게 호흡저해제를 스크리닝 할 수 있는 방법으로 여겨진다.

• 생명과학회지
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• 제20권4호
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• pp.474-480
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• 2010

흰쥐에서 Interleukin-1 (IL-1)으로 유도된 급성폐손상에서의 group II phospholipase $A_2$ ($PLA_2$) 억제제인 rutin의 효과를 알아보기 위하여 본 연구를 시행하였다. Rutin은 IL-1에 의해 증가한 폐장내의 myeloperoxidase의 활성도를 감소시키지는 못하였으나 폐포세척액 내의 호중구의 수 및 모세혈관의 손상지표로 알려져 있는 폐장 모세혈관에서의 단백질 누출양을 감소시켰다. 동시에 rutin은 IL-1에 의하여 증가한 폐장의 염증조절효소인 $PLA_2$의 활성도를 감소시키고 결과적으로 호중구에서의 산소기의 생성을 감소시켰다. Rutin 뿐만 아니라 manoalide, scalaradial 같은 group II $PLA_2$의 억제제도 호중구의 respiratory burst를 감소시킴을 확인하였다. IL-1에 의하여 증가한 폐포세척액 내에서의 cytokine induced neutrophil chemoattractant의 농도는 rutin에 의해 영향을 받지 않았다. 형태학적으로는 IL-1에 의한 폐장조직에서의 산소기의 형성이 관찰되었고 rutin은 이러한 산소기의 생성을 현저히 감소시켰다. 이러한 결과로 미루어 group II $PLA_2$ 억제제인 rutin은 호중구에서의 활성 산소기의 생성을 효과적으로 억제함으로써 IL-1에 의한 급성폐손상의 감소를 가져 오는 것으로 결론지을 수 있다.

• Tuberculosis and Respiratory Diseases
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• 제80권2호
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• pp.187-193
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• 2017

Background: Third-generation tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have proved efficacious in treating non-small cell lung cancer (NSCLC) patients with acquired resistance resulting from the T790M mutation. However, since almost 50% patients with the acquired resistance do not harbor the T790M mutation, retreatment with first- or second-generation EGFR-TKIs may be a more viable therapeutic option. Here, we identified positive response predictors to retreatment, in patients who switched to a different EGFR-TKI, following initial treatment failure. Methods: This study retrospectively reviewed the medical records of 42 NSCLC patients with EGFR mutations, whose cancers had progressed following initial treatment with gefitinib or erlotinib, and who had switched to a different first-generation EGFR-TKI during subsequent retreatment. To identify high response rate predictors in the changed EGFR-TKI retreatment, we analyzed the relationship between clinical and demographic parameters, and positive clinical outcomes, following retreatment with EGFR-TKI. Results: Overall, 30 (71.4%) patients received gefitinib and 12 (28.6%) patients received erlotinib as their first EGFR-TKI treatment. Following retreatment with a different EGFR-TKI, the overall response and disease control rates were 21.4% and 64.3%, respectively. There was no significant association between their overall responses. The median progression-free survival (PFS) after retreatment was 2.0 months. However, PFS was significantly longer in patients whose time to progression was ${\geq}10months$ following initial EGFR-TKI treatment, who had a mutation of exon 19, or whose treatment interval was <90 days. Conclusion: In patients with acquired resistance to initial EGFR-TKI therapy, switched EGFR-TKI retreatment may be a salvage therapy for individuals possessing positive retreatment response predictors.