• Molecules and Cells
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• 제19권3호
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• pp.445-451
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• 2005

Activation-induced cytidine deaminase (AID) is needed for Ig class switch recombination (CSR). We explored the effect of LPS on the expression of AID during B cell differentiation, and the role of AID in IgA isotype expression. In normal spleen B cells, LPS increased AID transcription up to 48 h post-stimulation, i.e. around the time of Ig CSR. TGF-${\beta}1$ and AID were required for IgA expression, and LPS contributed to $TGF{\beta}1$-induced IgA production largely by inducing AID. Interestingly, LPS repressed AID transcription in $sIgA^+$ B cells but still stimulated IgA production mainly by increasing the rate of IgA secretion. Our data indicate that LPS contributes to $TGF{\beta}1$-induced IgA isotype expression in at least two ways: by stimulating AID transcription before CSR and by enhancing the IgA secretion rate after CSR.

• Biomolecules & Therapeutics
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• 제21권5호
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• pp.358-363
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• 2013

In the present study, we investigated the effect of intracellular glutathione (GSH) depletion in heart-derived H9c2 cells and its mechanism. L-buthionine-S,R-sulfoximine (BSO) induced the depletion of cellular GSH, and BSO-induced reactive oxygen species (ROS) production was inhibited by glutathione monoethyl ester (GME). Additionally, GME inhibited BSO-induced caspase-3 activation, annexin V-positive cells, and annexin V-negative/propidium iodide (PI)-positive cells. Treatment with rottlerin completely blocked BSO-induced cell death and ROS generation. BSO-induced GSH depletion caused a translocation of PKC-${\delta}$ from the cytosol to the membrane fraction, which was inhibited by treatment with GME. From these results, it is suggested that BSO-induced depletion of cellular GSH causes an activation of PKC-${\delta}$ and, subsequently, generation of ROS, thereby inducing H9c2 cell death.

• BMB Reports
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• 제47권4호
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• pp.209-214
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• 2014

Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS) that promote apoptotic cell death. We showed that cytosolic $NADP^+$-dependent isocitrate dehydrogenase (IDPc) plays an essential role in the control of cellular redox balance and defense against oxidative damage, by supplying NADPH for antioxidant systems. In this study, we demonstrated that knockdown of IDPc expression by RNA interference enhances UVB-induced apoptosis of immortalized human HaCaT keratinocytes. This effect manifested as DNA fragmentation, changes in cellular redox status, mitochondrial dysfunction, and modulation of apoptotic marker expression. Based on our findings, we suggest that attenuation of IDPc expression may protect skin from UVB-mediated damage, by inducing the apoptosis of UV-damaged cells.

• International Journal of Oral Biology
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• 제41권1호
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• pp.39-43
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• 2016

Dental caries, the most common oral disease, is a multifactorial disease caused by interactions among bacteria within the dental plaque, food, and saliva, resulting in tooth destruction. Streptococcus mutans has been strongly implicated as the causative organism in dental caries and is frequently isolated from human dental plaque. Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. Postantibiotic effect (PAE) is defined as the duration of suppressed bacterial growth following brief exposure to an antibiotic. In this study, the in vitro PAE of PDT using erythrosine and light emitting diode on S. mutans ATCC 25175 was investigated. The PAE of PDT for 1 s irradiation and 3 s irradiation were 1.65 h and 2.1 h, respectively. The present study thus confirmed PAE of PDT using erythrosine on S. mutans.

• Natural Product Sciences
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• 제23권1호
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• pp.16-20
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• 2017

In a continuing study of the fermented noni (Morinda citrifolia) juice exudates, five compounds, heptanyl $2-O-{\beta}-{\small{D}}-xylofuranosyl-(1{\rightarrow}6)-{\beta}-{\small{D}}-glucopyranoside$ (1), n-butyl ${\beta}-{\small{D}}-glucopyranoside$ (2), (1S)-(3-ethenyl-phenyl)-1,2-ethanediol (3), (2S)-2-hydroxybutanedioic acid (4), and daucosterol (5) were isolated from the buthanol partition of the extract. The structures of the isolates were identified by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with the published values. Among the isolates, compounds 1 - 3 were isolated for the first time from the plant species. The isolated compounds were evaluated for their cancer chemopreventive potential based on their ability to inhibit nitric oxide (NO) production and tumor necrosis factor alpha ($TNF-{\alpha}$)-induced $NF-{\kappa}B$ activity, and quinonone reductase-1 (QR1)-inducing effect.

• 수산경영론집
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• 제39권3호
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• pp.67-90
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• 2008

In this study, we aimed to build the basic calculation model for linkage effects of fishery industry among Korea, China and Japan. For the calculation, we reconstructed the asian international input-output table, and on the basis of the reconstructed table, we made some analyses on the inter-relations among 3 nations focusing fishery industry. As the results, some positive backward linkage offsets of the fishery industries were found among 3 nations, and especially, production inducing effect of Chinese fishery industry to Japanese supplier was remarkable.

• BMB Reports
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• 제52권12호
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• pp.679-688
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• 2019

The decrease of metabolism in the brain has been observed as the important lesions of Alzheimer's disease (AD) from the early stages of diagnosis. The cumulative evidence has reported that the failure of mitochondria, an organelle involved in diverse biological processes as well as energy production, maybe the cause or effect of the pathogenesis of AD. Both amyloid and tau pathologies have an impact upon mitochondria through physical interaction or indirect signaling pathways, resulting in the disruption of mitochondrial function and dynamics which can trigger AD. In addition, mitochondria are involved in different biological processes depending on the specific functions of each cell type in the brain. Thus, it is necessary to understand mitochondrial dysfunction as part of the pathological phenotypes of AD according to each cell type. In this review, we summarize that 1) the effects of AD pathology inducing mitochondrial dysfunction and 2) the contribution of mitochondrial dysfunction in each cell type to AD pathogenesis.

• 한국멀티미디어학회논문지
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• 제9권3호
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• pp.353-359
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• 2006

학습자 중심의 다양한 수업 방법을 시도하는 교육 여건에 부응하여 학습자로 하여금 학습 동기를 유발하고 학습의 흥미를 유발시켜 학습의 효과를 높이고, 학생들 스스로 해결해 나가는 자기 주도적 학습 방법인 프로젝트 기반 교육법을 비주얼 베이직 교과에 적용하여 프로젝트를 완성해 가는 과정을 통해 문제 해결력을 신장시키고자 한다. 본 논문에서는 비주얼베이직 교과에 프로젝트 기반 교육을 적용하여 학습효과가 뛰어난 교육컨텐츠를 개발하였다. 특히 최근 웹 저작도구로 알려 진 FLASH MX와 PHOTOSHOP 프로그램을 이용하여 기존의 교육컨텐츠와 차별성을 두어 애니메이션의 적극적인 활용으로 학습자의 흥미와 집중력을 유도하고 컴퓨터와 학습자 사이의 상호작용이 가능한 비주얼베이직 학습을 위한 프로젝트 기반 교육 컨텐츠를 설계 및 구현하였다. 이를 적용한 결과 학습 효과에 상당한 효과가 있음을 보였다.

• 대한한의학방제학회지
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• 제26권4호
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• pp.329-340
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• 2018

Objectives : In Traditional Korean medicine, Daucus carota L. has been used for treating dyspepsia, diarrhea, dysentery and cough. Recent pharmacognosic evidence showed D. carota has anti-oxidant, anti-cancer, anti-fungal, and hypotensive effects. Present study investigated hepato-protective effect of D. carota ethanol extract (DCE) against oxidative stress in HepG2 cells. Methods : After HepG2 cells were pretreated with different concentrations of DCE, the cells were exposed to tert-butyl hydroperoxide (tBHP) for inducing oxidative stress. Cell viability, hydrogen peroxide production, glutathione concentration, and mitochondrial membrane potentials were measured to explore hepato-protective effect of DCE. Phosphorylation of AMP-activated protein kinase (AMPK) and effect of compound C on cell viability were determined to investigate the role of AMPK on DCE-mediated cytoprotection. Results : DCE significantly decreased the tBHP-mediated cytotoxicity in a concentration dependent manner and reduced the changes on apoptosis-related proteins by tBHP in HepG2 cells. In addition, DCE significantly prevented hydrogen peroxide production, glutathione depletion, and mitochondrial membrane impairment induced by tBHP. Treatment with DCE increased phosphorylation of AMPK, and the DCE-mediated cytoprotection was abolished by pretreatment with compound C. Conclusions : These results demonstrate that DCE can protect hepatocytes from oxidative stress through activation of AMPK.

• Animal Bioscience
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• 제35권2호
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• pp.184-195
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• 2022

Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle. Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0%, 0.05%, 0.075%, 0.1%, 0.125%, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9, and 12 h post-feeding on 30 d. Results: After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and Megasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion: The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be an important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.