2,261 results on '"Young-Ho Lee"'
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2. The dopamine analogue CA140 alleviates AD pathology, neuroinflammation, and rescues synaptic/cognitive functions by modulating DRD1 signaling or directly binding to Abeta
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Sehyun Chae, Hyun-ju Lee, Ha-Eun Lee, Jieun Kim, Yoo Joo Jeong, Yuxi Lin, Hye Yun Kim, Geoffray Leriche, Rachel S. Ehrlich, Sascha Castro Lingl, Min-Duk Seo, Young-Ho Lee, Jerry Yang, Jae-Ick Kim, and Hyang-Sook Hoe
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CA140 ,Dopamine D1 receptor ,Learning and memory ,LTP ,Aβ ,Tau ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background We recently reported that the dopamine (DA) analogue CA140 modulates neuroinflammatory responses in lipopolysaccharide-injected wild-type (WT) mice and in 3-month-old 5xFAD mice, a model of Alzheimer’s disease (AD). However, the effects of CA140 on Aβ/tau pathology and synaptic/cognitive function and its molecular mechanisms of action are unknown. Methods To investigate the effects of CA140 on cognitive and synaptic function and AD pathology, 3-month-old WT mice or 8-month-old (aged) 5xFAD mice were injected with vehicle (10% DMSO) or CA140 (30 mg/kg, i.p.) daily for 10, 14, or 17 days. Behavioral tests, ELISA, electrophysiology, RNA sequencing, real-time PCR, Golgi staining, immunofluorescence staining, and western blotting were conducted. Results In aged 5xFAD mice, a model of AD pathology, CA140 treatment significantly reduced Aβ/tau fibrillation, Aβ plaque number, tau hyperphosphorylation, and neuroinflammation by inhibiting NLRP3 activation. In addition, CA140 treatment downregulated the expression of cxcl10, a marker of AD-associated reactive astrocytes (RAs), and c1qa, a marker of the interaction of RAs with disease-associated microglia (DAMs) in 5xFAD mice. CA140 treatment also suppressed the mRNA levels of s100β and cxcl10, markers of AD-associated RAs, in primary astrocytes from 5xFAD mice. In primary microglial cells from 5xFAD mice, CA140 treatment increased the mRNA levels of markers of homeostatic microglia (cx3cr1 and p2ry12) and decreased the mRNA levels of a marker of proliferative region-associated microglia (gpnmb) and a marker of lipid-droplet-accumulating microglia (cln3). Importantly, CA140 treatment rescued scopolamine (SCO)-mediated deficits in long-term memory, dendritic spine number, and LTP impairment. In aged 5xFAD mice, these effects of CA140 treatment on cognitive/synaptic function and AD pathology were regulated by dopamine D1 receptor (DRD1)/Elk1 signaling. In primary hippocampal neurons and WT mice, CA140 treatment promoted long-term memory and dendritic spine formation via effects on DRD1/CaMKIIα and/or ERK signaling. Conclusions Our results indicate that CA140 improves neuronal/synaptic/cognitive function and ameliorates Aβ/tau pathology and neuroinflammation by modulating DRD1 signaling in primary hippocampal neurons, primary astrocytes/microglia, WT mice, and aged 5xFAD mice.
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- 2024
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3. Structural basis for ligand recognition and signaling of hydroxy-carboxylic acid receptor 2
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Jae-Hyun Park, Kouki Kawakami, Naito Ishimoto, Tatsuya Ikuta, Mio Ohki, Toru Ekimoto, Mitsunori Ikeguchi, Dong-Sun Lee, Young-Ho Lee, Jeremy R. H. Tame, Asuka Inoue, and Sam-Yong Park
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Science - Abstract
Abstract Hydroxycarboxylic acid receptors (HCAR1, HCAR2, and HCAR3) transduce Gi/o signaling upon biding to molecules such as lactic acid, butyric acid and 3-hydroxyoctanoic acid, which are associated with lipolytic and atherogenic activity, and neuroinflammation. Although many reports have elucidated the function of HCAR2 and its potential as a therapeutic target for treating not only dyslipidemia but also neuroimmune disorders such as multiple sclerosis and Parkinson’s disease, the structural basis of ligand recognition and ligand-induced Gi-coupling remains unclear. Here we report three cryo-EM structures of the human HCAR2–Gi signaling complex, each bound with different ligands: niacin, acipimox or GSK256073. All three agonists are held in a deep pocket lined by residues that are not conserved in HCAR1 and HCAR3. A distinct hairpin loop at the HCAR2 N-terminus and extra-cellular loop 2 (ECL2) completely enclose the ligand. These structures also reveal the agonist-induced conformational changes propagated to the G-protein-coupling interface during activation. Collectively, the structures presented here are expected to help in the design of ligands specific for HCAR2, leading to new drugs for the treatment of various diseases such as dyslipidemia and inflammation.
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- 2023
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4. Diselenide-bond replacement of the external disulfide bond of insulin increases its oligomerization leading to sustained activity
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Kenta Arai, Masaki Okumura, Young-Ho Lee, Hidekazu Katayama, Kenji Mizutani, Yuxi Lin, Sam-Yong Park, Kaichiro Sawada, Masao Toyoda, Hironobu Hojo, Kenji Inaba, and Michio Iwaoka
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Chemistry ,QD1-999 - Abstract
Abstract Seleno-insulin, a class of artificial insulin analogs, in which one of the three disulfide-bonds (S-S’s) of wild-type insulin (Ins) is replaced by a diselenide-bond (Se-Se), is attracting attention for its unique chemical and physiological properties that differ from those of Ins. Previously, we pioneered the development of a [C7UA,C7UB] analog of bovine pancreatic insulin (SeIns) as the first example, and demonstrated its high resistance against insulin-degrading enzyme (IDE). In this study, the conditions for the synthesis of SeIns via native chain assembly (NCA) were optimized to attain a maximum yield of 72%, which is comparable to the in vitro folding efficiency for single-chain proinsulin. When the resistance of BPIns to IDE was evaluated in the presence of SeIns, the degradation rate of BPIns became significantly slower than that of BPIns alone. Furthermore, the investigation on the intermolecular association properties of SeIns and BPIns using analytical ultracentrifugation suggested that SeIns readily forms oligomers not only with its own but also with BPIns. The hypoglycemic effect of SeIns on diabetic rats was observed at a dose of 150 μg/300 g rat. The strategy of replacing the solvent-exposed S-S with Se-Se provides new guidance for the design of long-acting insulin formulations.
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- 2023
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5. Electrochemical corrosion behavior of atmospheric-plasma-sprayed copper as a coating material for deep geological disposal canisters
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Sung-Wook Kim, Gha-Young Kim, Young-Ho Lee, Jun-Hyuk Jang, Chung-Won Lee, Jeong-Hyun Woo, and Seok Yoon
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Deep geological disposal ,Canister ,Copper ,Additive manufacturing ,Atmospheric plasma spraying ,Electrochemistry ,Nuclear engineering. Atomic power ,TK9001-9401 - Abstract
Cu, which exhibits excellent corrosion resistance in underground environments, has been investigated as a canister material for use in the deep geological disposal of spent nuclear fuels. In this study, the technical viability of atmospheric plasma spraying for producing Cu-coated canisters was investigated. A high-purity Cu film (millimeter scale) was deposited onto a stainless-steel substrate using a plasma gun with a shroud structure. Potentiodynamic polarization studies revealed that the Cu film exhibited a sufficiently low corrosion rate in the groundwater electrolyte. In addition, no pitting corrosion was observed on the Cu film surface after accelerated corrosion studies. A prototype cylindrical Cu film was fabricated on a 1/20 scale on a stainless-steel tube to demonstrate the scalability of atmospheric plasma spraying in producing Cu-coated canisters.
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- 2023
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6. APP‐C31: An Intracellular Promoter of Both Metal‐Free and Metal‐Bound Amyloid‐β40 Aggregation and Toxicity in Alzheimer's Disease
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Eunju Nam, Yuxi Lin, Jiyong Park, Hyunsu Do, Jiyeon Han, Bohyeon Jeong, Subin Park, Da Yong Lee, Mingeun Kim, Jinju Han, Mu‐Hyun Baik, Young‐Ho Lee, and Mi Hee Lim
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accelerator toward amyloidogenesis ,amyloid precursor protein ,amyloid‐β ,metal ions ,protein–protein interaction ,Science - Abstract
Abstract Intracellular C‐terminal cleavage of the amyloid precursor protein (APP) is elevated in the brains of Alzheimer's disease (AD) patients and produces a peptide labeled APP‐C31 that is suspected to be involved in the pathology of AD. But details about the role of APP‐C31 in the development of the disease are not known. Here, this work reports that APP‐C31 directly interacts with the N‐terminal and self‐recognition regions of amyloid‐β40 (Aβ40) to form transient adducts, which facilitates the aggregation of both metal‐free and metal‐bound Aβ40 peptides and aggravates their toxicity. Specifically, APP‐C31 increases the perinuclear and intranuclear generation of large Aβ40 deposits and, consequently, damages the nucleus leading to apoptosis. The Aβ40‐induced degeneration of neurites and inflammation are also intensified by APP‐C31 in human neurons and murine brains. This study demonstrates a new function of APP‐C31 as an intracellular promoter of Aβ40 amyloidogenesis in both metal‐free and metal‐present environments, and may offer an interesting alternative target for developing treatments for AD that have not been considered thus far.
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- 2024
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7. Inhibition of histone methyltransferase Smyd3 rescues NMDAR and cognitive deficits in a tauopathy mouse model
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Jamal B. Williams, Qing Cao, Wei Wang, Young-Ho Lee, Luye Qin, Ping Zhong, Yong Ren, Kaijie Ma, and Zhen Yan
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Science - Abstract
The study by Williams et al shows targeting the aberrant histone modifying enzyme Smyd3 rescues NMDAR and cognitive deficits in a mouse model of Alzheimer’s disease. It highlights the potential of epigenetic treatment in neurodegenerative diseases.
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- 2023
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8. Observation of a new type of self-generated current in magnetized plasmas
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Yong-Su Na, Jaemin Seo, Yoonji Lee, Gyungjin Choi, Minseo Park, Sangjin Park, Sumin Yi, Weixing Wang, Min-Gu Yoo, Minsoo Cha, Beomsu Kim, Young-Ho Lee, Hyunsun Han, Boseong Kim, Chanyoung Lee, SangKyeun Kim, SeongMoo Yang, Cheol-Sik Byun, Hyun-Seok Kim, Jinseok Ko, Woochang Lee, and Taik Soo Hahm
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Science - Abstract
Fusion devices like tokamaks require plasma current to generate magnetic field for plasma confinement. Here the authors report an observation of a self-generated anomalous current that contributes up to 30% of the total current in the fusion plasma at KSTAR.
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- 2022
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9. Structure of cyanobacterial photosystem I complexed with ferredoxin at 1.97 Å resolution
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Jiannan Li, Noriyuki Hamaoka, Fumiaki Makino, Akihiro Kawamoto, Yuxi Lin, Matthias Rögner, Marc M. Nowaczyk, Young-Ho Lee, Keiichi Namba, Christoph Gerle, and Genji Kurisu
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Biology (General) ,QH301-705.5 - Abstract
In order to aid the understanding of the electron transfer process within the cyanobacterial photosystem I, its structure - when complexed with Ferredoxin - is determined at 1.97 Å resolution.
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- 2022
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10. Engineering second-generation TCR-T cells by site-specific integration of TRAF-binding motifs into the CD247 locus
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Sangjoon Lah, Segi Kim, In Kang, Cedric Hupperetz, Hyuncheol Jung, Hyeong Ryeol Choi, Young-Ho Lee, Hyeon-Ki Jang, Sangsu Bae, and Chan Hyuk Kim
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Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background The incorporation of co-stimulatory signaling domains into second-generation chimeric antigen receptors (CARs) significantly enhances the proliferation and persistence of CAR-T cells in vivo, leading to successful clinical outcomes.Methods To achieve such functional enhancement in transgenic T-cell receptor-engineered T-cell (TCR-T) therapy, we designed a second-generation TCR-T cell in which CD3ζ genes modified to contain the intracellular domain (ICD) of the 4-1BB receptor were selectively inserted into the CD247 locus.Results This modification enabled the simultaneous recruitment of key adaptor molecules for signals 1 and 2 on TCR engagement. However, the addition of full-length 4-1BB ICD unexpectedly impaired the expression and signaling of TCRs, leading to suboptimal antitumor activity of the resulting TCR-T cells in vivo. We found that the basic-rich motif (BRM) in the 4-1BB ICD was responsible for the undesirable outcomes, and that fusion of minimal tumor necrosis factor receptor-associated factor (TRAF)-binding motifs at the C-terminus of CD3ζ (zBBΔBRM) was sufficient to recruit TRAF2, the key adaptor molecule in 4-1BB signaling, while retaining the expression and proximal signaling of the transgenic TCR. Consequently, TCR-T cells expressing zBBΔBRM exhibited improved persistence and expansion in vitro and in vivo, resulting in superior antitumor activity in a mouse xenograft model.Conclusions Our findings offer a promising strategy for improving the intracellular signaling of TCR-T cells and their application in treating solid tumors.
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- 2023
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11. Effects of 3-methyladenine, an autophagy inhibitor, on the elevated blood pressure and arterial dysfunction of angiotensin II-induced hypertensive mice
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Youngin Kwon, Chae Eun Haam, Seonhee Byeon, Soo-Kyoung Choi, and Young-Ho Lee
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Autophagy ,Mesenteric artery ,Angiotensin II ,Hypertension ,Endothelium-dependent relaxation ,Nitric Oxide ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Autophagy is an intracellular degradation system that disassembles cytoplasmic components through autophagosomes fused with lysosomes. Recently, it has been reported that autophagy is associated with cardiovascular diseases, including pulmonary hypertension, atherosclerosis, and myocardial ischemia. However, the involvement of autophagy in hypertension is not well understood. In the present study, we hypothesized that excessive autophagy contributes to the dysfunction of mesenteric arteries in angiotensin II (Ang II)-induced hypertensive mice. Treatment of an autophagy inhibitor, 3-methyladenine (3-MA), reduced the elevated blood pressure and wall thickness, and improved endothelium-dependent relaxation in mesenteric arteries of Ang II-treated mice. The expression levels of autophagy markers, beclin1 and LC3 II, were significantly increased by Ang II infusion, which was reduced by treatment of 3-MA. Furthermore, treatment of 3-MA induced vasodilation in the mesenteric resistance arteries pre-contracted with U46619 or phenylephrine, which was dependent on endothelium. Interestingly, nitric oxide production and phosphorylated endothelial nitric oxide synthase (p-eNOS) at S1177 in the mesenteric arteries of Ang II-treated mice were increased by treatment with 3-MA. In HUVECs, p-eNOS was reduced by Ang II, which was increased by treatment of 3-MA. 3-MA had direct vasodilatory effect on the pre-contracted mesenteric arteries. In cultured vascular smooth muscle cells (VSMCs), Ang II induced increase in beclin1 and LC3 II and decrease in p62, which was reversed by treatment of 3-MA. These results suggest that autophagy inhibition exerts beneficial effects on the dysfunction of mesenteric arteries in hypertension.
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- 2022
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12. Polymorphism in alpha-synuclein oligomers and its implications in toxicity under disease conditions
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Je Min Yoo, Yuxi Lin, Yunseok Heo, and Young-Ho Lee
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alpha-synuclein ,oligomers ,polymorphism ,fibrillation ,toxicity ,disease progression ,Biology (General) ,QH301-705.5 - Abstract
The major hallmark of Parkinson’s disease (PD) is represented by the formation of pathological protein plaques largely consisting of α-synuclein (αSN) amyloid fibrils. Nevertheless, the implications of αSN oligomers in neuronal impairments and disease progression are more importantly highlighted than mature fibrils, as they provoke more detrimental damages in neuronal cells and thereby exacerbate α-synucleinopathy. Interestingly, although generation of oligomeric species under disease conditions is likely correlated to cytotoxicity and different cellular damages, αSN oligomers manifest varying toxicity profiles dependent on the specific environments as well as the shapes and conformations the oligomers adopt. As such, this minireview discusses polymorphism in αSN oligomers and the association of the underlying heterogeneity in regard to toxicity under pathological conditions.
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- 2022
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13. Author’s Reply to 'Concerns regarding Validity of the Use of Bean Extract-Based Gargle for COVID-19 Diagnosis'
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Joseph Kwon, Euna Ko, Se-Young Cho, Young-Ho Lee, Sangmi Jun, Kyuhong Lee, Eunha Hwang, Bipin Vaidya, Jeong-Hwan Hwang, Joo-Hee Hwang, Namsu Kim, Mi-Kyung Song, Hye-Yeon Kim, Dai Ito, Yuxi Lin, Eunae Jo, Kyeong Eun Yang, Hee-Chung Chung, Soyoung Cha, Dong Im Kim, Yoon-Sun Yi, Sung-Ho Yun, Sun Cheol Park, Sangmin Lee, Jong-Soon Choi, Dal Sik Kim, and Duwoon Kim
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COVID-19 ,SARS-CoV-2 ,oral virus ,rapid diagnostic test ,sensitivity ,specificity ,Microbiology ,QR1-502 - Published
- 2022
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14. Dual Effects of Presynaptic Membrane Mimetics on α-Synuclein Amyloid Aggregation
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Yuxi Lin, Dai Ito, Je Min Yoo, Mi Hee Lim, Wookyung Yu, Yasushi Kawata, and Young-Ho Lee
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amyloid fibril ,α-Synuclein ,electrostatic interaction ,helical structure ,intermolecular interaction ,membrane mimetic ,Biology (General) ,QH301-705.5 - Abstract
Aggregation of intrinsically disordered α-synuclein (αSN) under various conditions is closely related to synucleinopathies. Although various biological membranes have shown to alter the structure and aggregation propensity of αSN, a thorough understanding of the molecular and mechanical mechanism of amyloidogenesis in membranes remains unanswered. Herein, we examined the structural changes, binding properties, and amyloidogenicity of three variations of αSN mutants under two types of liposomes, 1,2-Dioleoyl-sn-glycero-3-Phosphocholine (DOPC) and presynaptic vesicle mimetic (Mimic) membranes. While neutrally charged DOPC membranes elicited marginal changes in the structure and amyloid fibrillation of αSNs, negatively charged Mimic membranes induced dramatic helical folding and biphasic amyloid generation. At low concentration of Mimic membranes, the amyloid fibrillation of αSNs was promoted in a dose-dependent manner. However, further increases in the concentration constrained the fibrillation process. These results suggest the dual effect of Mimic membranes on regulating the amyloidogenesis of αSN, which is rationalized by the amyloidogenic structure of αSN and condensation-dilution of local αSN concentration. Finally, we propose physicochemical properties of αSN and membrane surfaces, and their propensity to drive electrostatic interactions as decisive factors of amyloidogenesis.
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- 2022
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15. Bean Extract-Based Gargle for Efficient Diagnosis of Active COVID-19 Infection Using Rapid Antigen Tests
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Joseph Kwon, Euna Ko, Se-Young Cho, Young-Ho Lee, Sangmi Jun, Kyuhong Lee, Eunha Hwang, Bipin Vaidya, Jeong-Hwan Hwang, Joo-Hee Hwang, Namsu Kim, Mi-Kyung Song, Hye-Yeon Kim, Dai Ito, Yuxi Lin, Eunae Jo, Kyeong Eun Yang, Hee-Chung Chung, Soyoung Cha, Dong Im Kim, Yoon-Sun Yi, Sung-Ho Yun, Sun Cheol Park, Sangmin Lee, Jong-Soon Choi, Dal Sik Kim, and Duwoon Kim
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COVID-19 ,oral virus ,rapid diagnostic test ,SARS-CoV-2 ,sensitivity ,specificity ,Microbiology ,QR1-502 - Abstract
ABSTRACT The antigen-based rapid diagnostic test (Ag-RDT) using saliva specimens is fast, noninvasive, and suitable for SARS-CoV-2 self-testing, unlike nasopharyngeal swab (NPS) testing. We evaluated a novel Beanguard gargle (BG)-based virus collection method that can be applied to Ag-RDT as an alternative to the current RT-PCR with an NPS for early diagnosis of COVID-19. This clinical trial comprised 102 COVID-19-positive patients hospitalized after a governmental screening process and 100 healthy individuals. Paired NPS and BG-based saliva specimens from COVID-19 patients and healthy individuals were analyzed using NPS-RT-PCR, BG-RT-PCR, and BG-Ag-RDTs, whose diagnostic performance for detecting SARS-CoV-2 was compared. BG-Ag-RDTs showed high sensitivity (97.8%) and specificity (100%) in 45 patients within 6 days of illness and detected all cases of SARS-CoV-2 Alpha and Delta variants. In 11 asymptomatic active COVID-19 cases, both BG-Ag-RDTs and BG-RT-PCR showed sensitivities and specificities of 100%. Sensitivities of BG-Ag-RDT and BG-RT-PCR toward salivary viral detection were highly concordant, with no discrimination between symptomatic (97.0%), asymptomatic (100%), or SARS-CoV-2 variant (100%) cases. The intermolecular interactions between SARS-CoV-2 spike proteins and truncated canavalin, an active ingredient from the bean extract (BE), were observed in terms of physicochemical properties. The detachment of the SARS-CoV-2 receptor-binding domain from hACE2 increased as the BE concentration increased, allowing the release of the virus from hACE2 for early diagnosis. Using BG-based saliva specimens remarkably enhances the Ag-RDT diagnostic performance as an alternative to NPS and enables noninvasive, rapid, and accurate COVID-19 self-testing and mass screening, supporting efficient COVID-19 management. IMPORTANCE An Ag-RDT is less likely to be accepted as an initial test method for early diagnosis owing to its low sensitivity. However, our self-collection method, Ag-RDT using BG-based saliva specimens, showed significantly enhanced detection sensitivity and specificity toward SARS-CoV-2 including the Alpha and Delta variants in all patients tested within 6 days of illness. The method represents an attractive alternative to nasopharyngeal swabs for the early diagnosis of symptomatic and asymptomatic COVID-19 cases. The evidence suggests that the method could have a potential for mass screening and monitoring of COVID-19 cases.
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- 2022
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16. Vanillin Induces Relaxation in Rat Mesenteric Resistance Arteries by Inhibiting Extracellular Ca2+ Influx
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Sooyeon Choi, Chae Eun Haam, Eun-Yi Oh, Seonhee Byeon, Soo-Kyoung Choi, and Young-Ho Lee
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vanillin ,Ca2+ ,mesenteric resistance arteries ,relaxation ,vasodilation ,Organic chemistry ,QD241-441 - Abstract
Vanillin is a phenolic aldehyde, which is found in plant species of the Vanilla genus. Although recent studies have suggested that vanillin has various beneficial properties, the effect of vanillin on blood vessels has not been studied well. In the present study, we investigated whether vanillin has vascular effects in rat mesenteric resistance arteries. To examine the vascular effect of vanillin, we measured the isometric tension of arteries using a multi-wire myograph system. After the arteries were pre-contracted with high K+ (70 mM) or phenylephrine (5 µM), vanillin was administered. Vanillin induced concentration-dependent vasodilation. Endothelial denudation or treatment of eNOS inhibitor (L-NNA, 300 μM) did not affect the vasodilation induced by vanillin. Treatment of K+ channel inhibitor (TEA, 10 mM) or sGC inhibitor (ODQ, 10 μM) or COX-2 inhibitor (indomethacin, 10 μM) did not affect the vanillin-induced vasodilation either. The treatment of vanillin decreased the contractile responses induced by Ca2+ addition. Furthermore, vanillin significantly reduced vascular contraction induced by BAY K 8644 (30 nM). Vanillin induced concentration-dependent vascular relaxation in rat mesenteric resistance arteries, which was endothelium-independent. Inhibition of extracellular Ca2+ influx was involved in vanillin-induced vasodilation. Treatment of vanillin reduced phopsho-MLC20 in vascular smooth muscle cells. These results suggest the possibility of vanillin as a potent vasodilatory molecule.
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- 2022
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17. Aggregation-Prone Structural Ensembles of Transthyretin Collected With Regression Analysis for NMR Chemical Shift
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Wonjin Yang, Beom Soo Kim, Srinivasan Muniyappan, Young-Ho Lee, Jin Hae Kim, and Wookyung Yu
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transthyretin ,nuclear magnetic resonance chemical shift ,molecular dynamics computer simulation ,protein aggregation ,ensemble structure ,linear regression ,Biology (General) ,QH301-705.5 - Abstract
Monomer dissociation and subsequent misfolding of the transthyretin (TTR) is one of the most critical causative factors of TTR amyloidosis. TTR amyloidosis causes several human diseases, such as senile systemic amyloidosis and familial amyloid cardiomyopathy/polyneuropathy; therefore, it is important to understand the molecular details of the structural deformation and aggregation mechanisms of TTR. However, such molecular characteristics are still elusive because of the complicated structural heterogeneity of TTR and its highly sensitive nature to various environmental factors. Several nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) studies of TTR variants have recently reported evidence of transient aggregation-prone structural states of TTR. According to these studies, the stability of the DAGH β-sheet, one of the two main β-sheets in TTR, is a crucial determinant of the TTR amyloidosis mechanism. In addition, its conformational perturbation and possible involvement of nearby structural motifs facilitates TTR aggregation. This study proposes aggregation-prone structural ensembles of TTR obtained by MD simulation with enhanced sampling and a multiple linear regression approach. This method provides plausible structural models that are composed of ensemble structures consistent with NMR chemical shift data. This study validated the ensemble models with experimental data obtained from circular dichroism (CD) spectroscopy and NMR order parameter analysis. In addition, our results suggest that the structural deformation of the DAGH β-sheet and the AB loop regions may correlate with the manifestation of the aggregation-prone conformational states of TTR. In summary, our method employing MD techniques to extend the structural ensembles from NMR experimental data analysis may provide new opportunities to investigate various transient yet important structural states of amyloidogenic proteins.
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- 2021
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18. Bilateral Tonic Pupils and Guillain-Barre Syndrome in a 6-Year-Old Boy
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Shin-Hye Hong, Sung Hwan Byun, Eun Hee Hong, Young-Ho Lee, and Jin-Hwa Moon
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Internal medicine ,RC31-1245 ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 ,Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2019
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19. The effect of Lactobacillus plantarum hydrolysates promoting VEGF production on vascular growth and hair growth of C57BL/6 mice
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Young Min Woo, Ok Ju Kim, Eun Sol Jo, Min Young Jo, Mee Young Ahn, Young-Ho Lee, Chun-ri Li, Sang-Hyeon Lee, Jae-Suk Choi, Jong Myung Ha, and Andre Kim
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Vascular endothelial growth factor (VEGF) ,Lactobacillus plantarum ,Protease ,Human dermal papilla cell (hDPC) ,Hair growth ,Chemistry ,QD1-999 ,Analytical chemistry ,QD71-142 - Abstract
Abstract Purpose Angiogenesis is critical in various biological processes, such as blood vessel growth, fetal differentiation, wound healing, and organ regeneration. Various growth factors have been associated with vascular regeneration, including insulin-like growth factor 1 (IGF-1), transforming growth factor-β (TGF-β), and basic fibroblast growth factor (bFGF). One of the most important mediators of vascular regeneration is vascular endothelial growth factor (VEGF). VEGF is known to increase vascular permeability, induce the proliferation of endothelial cells, and stimulate capillary formation in vivo, which are core angiogenic functions. Methods The hydrolysates of lactic acid bacteria were produced by hydrolyzing Lactobacillus plantarum with proteases, treated with MG-63 osteoblasts, and screened to obtain samples with an excellent VEGF production effect. These samples were applied to human dermal papilla cells (hDPC) to examine the correlation between cell growth and VEGF secretion. Furthermore, the hair growth rate was measured in hair growth experiments using C57BL/6 male mice. Results The hydrolysates of the lactic acid bacteria produced in this study produced hair growth superior to the growth obtained with 5% minoxidil in hair growth experiments using C57BL/6 male mice. Conclusions This study aims to develop a material for application to the scalp that promotes angiogenesis in the scalp and facilitates the exchange of nutrients and wastes in the follicles to promote hair growth.
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- 2019
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20. Vasorelaxant Effect of Trachelospermi caulis Extract on Rat Mesenteric Resistance Arteries
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Chae Eun Haam, Seonhee Byeon, Sooyeon Choi, Eun Yi Oh, Soo-Kyoung Choi, and Young-Ho Lee
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Trachelospermi caulis ,vasodilation ,mesenteric resistance arteries ,vanillin ,relaxation ,Ca2+ ,Organic chemistry ,QD241-441 - Abstract
Background: Trachelospermi caulis (T. caulis) has been used as a traditional herbal medicine in Asian countries. Although it is well known that T. caulis has beneficial effects, no sufficient research data are available on the cardiovascular effect of T. caulis. We investigated whether T. caulis extract has vascular effects in rat resistance arteries in this study. Methods: To examine whether T. caulis extract affects vascular reactivity, we measured isometric tension of rat mesenteric resistance arteries using a multi-wire myograph system. T. caulis extract was administered after arteries were pre-contracted with high K+ (70 mM) or phenylephrine (5 µM). Vanillin, a single active component of T. caulis, was used to treat mesenteric arteries. Results: T. caulis extract caused vascular relaxation in a concentration-dependent manner, which was endothelium-independent. To further identify the mechanism, we incubated the arteries in Ca2+-free solution containing high K+, followed by a cumulative administration of CaCl2 (0.01–2.0 mM) with or without T. caulis extract (250 µg/mL). The treatment of T. caulis extract decreased contractile responses induced by the addition of Ca2+, which suggested that the extracellular Ca2+ influx was inhibited by the T. caulis extract. Moreover, an active compound of T. caulis extract, vanillin, also induced vasodilation in mesenteric resistance arteries. Conclusion: T. caulis extract and its active compound, vanillin, concentration-dependently induced vascular relaxation in mesenteric resistance arteries. These results suggest that the administration of T. caulis extract could help decrease blood pressure.
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- 2022
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21. A Study Comparing the Subsurface Vortex Characteristics in Pump Sumps
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Sangyoon Kim, Changgu Kim, Byungha Kim, Hyunjun Jang, Incheol Kim, and Young-Ho Lee
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pump sump ,particle image velocimetry (PIV) ,computational fluid dynamics (CFD) ,Technology - Abstract
The vortex generated around the suction region of the pump sump causes problems such as damage to the pump, increased maintenance costs, and failure to supply coolant smoothly. Therefore, analyzing vortices is essential in pump sump design. However, the CFD analysis alone is insufficient in pump sumps vortex analysis since the reliability of the results is doubtful in scaled model tests. This study conducted the model test to validate a suitable CFD simulation method by identifying the Type 2 vortex among the three types of subsurface vortices. The dye test and PIV technology were used to visualize the Type 2 subsurface vortices, whereas the PIV vorticity results were then compared to the CFD results. The average vorticity of 60.2 (1/s) was identified as the reference level of Type 2 subsurface vortices formation by mapping the dye test results with the PIV vorticity results. Furthermore, the average vorticities of 84.63 (1/s) and 85.15 (1/s) were recorded in the presence of Type 2 subsurface vortices in PIV and CFD, respectively, and these values can be applied to the designing of pump sumps.
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- 2022
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22. Deep-learning-based three-dimensional label-free tracking and analysis of immunological synapses of CAR-T cells
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Moosung Lee, Young-Ho Lee, Jinyeop Song, Geon Kim, YoungJu Jo, HyunSeok Min, Chan Hyuk Kim, and YongKeun Park
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chimeric antigen receptor T cells ,immunological synapse ,optical diffraction tomography ,deep learning ,quantitative phase imaging ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
The immunological synapse (IS) is a cell-cell junction between a T cell and a professional antigen-presenting cell. Since the IS formation is a critical step for the initiation of an antigen-specific immune response, various live-cell imaging techniques, most of which rely on fluorescence microscopy, have been used to study the dynamics of IS. However, the inherent limitations associated with the fluorescence-based imaging, such as photo-bleaching and photo-toxicity, prevent the long-term assessment of dynamic changes of IS with high frequency. Here, we propose and experimentally validate a label-free, volumetric, and automated assessment method for IS dynamics using a combinational approach of optical diffraction tomography and deep learning-based segmentation. The proposed method enables an automatic and quantitative spatiotemporal analysis of IS kinetics of morphological and biochemical parameters associated with IS dynamics, providing a new option for immunological research.
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- 2020
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23. Vasodilatory Effect of Alpinia officinarum Extract in Rat Mesenteric Arteries
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Chae Eun Haam, Seonhee Byeon, Soo Jung Choi, Soyeon Lim, Soo-Kyoung Choi, and Young-Ho Lee
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Alpinia officinarum ,mesenteric resistance arteries ,eucalyptol ,vasodilation ,relaxation ,Ca2+ ,Organic chemistry ,QD241-441 - Abstract
Background: Alpinia officinarum (A. officinarum) is known to exhibit a beneficial effect for anti-inflammatory, anti-oxidant, and anti-hyperlipidemic effects. However, no sufficient research data are available on the cardiovascular effect of A. officinarum. Thus, in this study, we investigate whether A. officinarum extract has direct effects on vascular reactivity. Methods: To examine whether A. officinarum extract affects vascular functionality, we measured isometric tension in rat mesenteric resistance arteries using a wire myograph. After arteries were pre-contracted with high-K+ (70 mM), phenylephrine (5 µM), or U46619 (1 µM), A. officinarum extract was treated. Results: A. officinarum extract induced vasodilation in a concentration-dependent manner, and this effect was endothelium independent. To further investigate the mechanism, we incubated arteries in a Ca2+-free and high-K+ solution, followed by the cumulative addition of CaCl2 (0.01–2.5 mM) with or without A. officinarum extract (30 µg/mL). Pre-treatment of A. officinarum extract reduced the contractile responses induced by cumulative administration of Ca2+, which suggests that extracellular Ca2+ influx was inhibited by the treatment of A. officinarum extract. These results were associated with a reduction in phosphorylated MLC20 in VSMCs treated with A. officinarum extract. Furthermore, eucalyptol, an active compound of A. officinarum extract, had a similar effect as A. officinarum extract, which causes vasodilation in mesenteric resistance arteries. Conclusion: A. officinarum extract and its active compound eucalyptol induce concentration-dependent vasodilation in mesenteric resistance arteries. These results suggest that administration of A. officinarum extract could exert beneficial effects to treat high blood pressure.
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- 2022
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24. Design Optimization of a Cross-Flow Air Turbine for an Oscillating Water Column Wave Energy Converter
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Hong-Goo Kang, Young-Ho Lee, Chan-Joo Kim, and Hyo-Dong Kang
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wave energy converter ,oscillating water column (OWC) ,cross-flow air turbine ,computational fluid dynamics (CFD) ,Technology - Abstract
A cross-flow air turbine, which is a self-rectifying, air-driven turbine, was designed and proposed for the power take-off (PTO) system of an oscillating water column (OWC) wave energy converter (WEC). To predict the complicated non-linear behavior of the air turbine in the OWC, numerical and experimental investigations were accomplished. The geometries of the nozzle and the rotor of the turbine were optimized under steady-flow conditions, and the performance analysis of the model in bi-directional flows was conducted by commercial computational fluid dynamics (CFD) code ANSYS CFX. Experimentation on the full-scale turbine was then undertaken in a cylindrical-type wave simulator that generated reciprocating air flows, to validate the numerical model. The optimized model had a peak cycle-averaged efficiency of 0.611, which is 1.7% larger than that of the reference model, and a significantly improved band width with an increase in flow coefficients. Under reciprocating-flow conditions, the optimized model had a more improved operating range with high efficiency compared to the performance derived from the steady-flow analysis, but the peak cycle-averaged efficiency was decreased by 4.3%. The numerical model was well matched to the experimental results with an averaged difference of 3.5%. The proposed optimal design having structural simplicity with high performance can be a good option to efficiently generate electricity.
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- 2022
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25. AdipoRon, adiponectin receptor agonist, improves vascular function in the mesenteric arteries of type 2 diabetic mice.
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Soo-Kyoung Choi, Youngin Kwon, Seonhee Byeon, Chae Eun Haam, and Young-Ho Lee
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Medicine ,Science - Abstract
BACKGROUND:An orally active synthetic adiponectin receptor agonist, AdipoRon has been suggested to ameliorate insulin resistance, and glucose tolerance. However, the chronic effect of AdipoRon in the vascular dysfunction in type 2 diabetes has not been studied yet. Thus, in this study, we examined whether AdipoRon improves vascular function in type 2 diabetes. METHODS:Type 2 diabetic (db-/db-) mice were treated with AdipoRon (10 mg/kg/everyday, by oral gavage) for 2 weeks. Body weight and blood glucose levels were recorded every other day during the experimental period. Diameter of mesenteric arteries was measured. And western blot analysis was performed with mesenteric arteries. RESULTS:Pressure-induced myogenic response was significantly increased while endothelium-dependent relaxation was reduced in the mesenteric arteries of db-/db- mice. Treatment of AdipoRon normalized potentiated myogenic response, whereas endothelium-dependent relaxation was not affected by treatment of AdipoRon. The expression levels of AdiR1, AdiR2, APPL1, and APPL 2 were increased in the mesenteric arteries of db-/db- mice and treatment of AdipoRon did not affect them. Interestingly, AdipoRon treatment increased the phospho-AMPK and decreased MYPT1 phosphorylation in db-/db- mice while there was no change in the level of eNOS phosphorylation. CONCLUSION:The treatment of AdipoRon improves vascular function in the mesenteric arteries of db-/db- mice through endothelium-independent mechanism. We suggest that MLCP activation through reduced phosphorylation of MYPT1 might be the dominant mechanism in the AdipoRon-induced vascular effect.
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- 2020
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26. FOWT Stability Study According to Number of Columns Considering Amount of Materials Used
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Ho-Seong Yang, Ali Alkhabbaz, Dylan Sheneth Edirisinghe, Watchara Tongphong, and Young-Ho Lee
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floating offshore wind turbine (FOWT) ,semi-submersible ,OrcaFlex ,ansys aqwa ,extreme condition ,fully-coupled analysis ,Technology - Abstract
Considering stability and fabrication cost, 3–4 columns are usually adopted for semi-submersible platform designs. Although increasing the number of columns provides more stability for both floating platform and system as a whole, it is generally not economically viable. In this respect, the present work provides a high-fidelity analysis of semi-submersible platform stability and hydrodynamic response for different design concepts. The number of columns was considered as the main design parameter and was varied from 3–6 columns. The semi-submersible weight was kept constant during the simulation period by changing the column diameter and amount of ballast water. The investigation was carried out using the potential code Orcawave, the results of which were input directly to the engineering tool OrcaFlex. Four different types of semi-submersible platforms with a varying number of columns were tested and compared under extreme environmental conditions in order to ensure their stability and hydrodynamic response. The simulation findings revealed that platform stability was more affected by the geometrical features of the floater than by the number of columns. Furthermore, the number of columns did not have a significant impact on hydrodynamic behavior for the same platform geometry.
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- 2022
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27. Molecular Effects of Elongation Factor Ts and Trigger Factor on the Unfolding and Aggregation of Elongation Factor Tu Induced by the Prokaryotic Molecular Chaperone Hsp33
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Minho Keum, Dai Ito, Mi-Seong Kim, Yuxi Lin, Kyeong-Hyeon Yoon, Jihoon Kim, Sung-Hee Lee, Ji-Hun Kim, Wookyung Yu, Young-Ho Lee, and Hyung-Sik Won
- Subjects
aggregase activity ,EF-Tu ,EF-Ts ,proteostasis ,Hsp33 ,molecular chaperone ,Biology (General) ,QH301-705.5 - Abstract
Hsp33, a prokaryotic redox-regulated holding chaperone, has been recently identified to be able to exhibit an unfoldase and aggregase activity against elongation factor Tu (EF-Tu) in its reduced state. In this study, we investigated the effect of elongation factor Ts (EF-Ts) and trigger factor (TF) on Hsp33-mediated EF-Tu unfolding and aggregation using gel filtration, light scattering, circular dichroism, and isothermal titration calorimetry. We found that EF-Tu unfolding and subsequent aggregation induced by Hsp33 were evident even in its complex state with EF-Ts, which enhanced EF-Tu stability. In addition, although TF alone had no substantial effect on the stability of EF-Tu, it markedly amplified the Hsp33-mediated EF-Tu unfolding and aggregation. Collectively, the present results constitute the first example of synergistic unfoldase/aggregase activity of molecular chaperones and suggest that the stability of EF-Tu is modulated by a sophisticated network of molecular chaperones to regulate protein biosynthesis in cells under stress conditions.
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- 2021
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28. Pathogenic D76N Variant of β2-Microglobulin: Synergy of Diverse Effects in Both the Native and Amyloid States
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Éva Bulyáki, Judit Kun, Tamás Molnár, Alexandra Papp, András Micsonai, Henrietta Vadászi, Borbála Márialigeti, Attila István Kovács, Gabriella Gellén, Keiichi Yamaguchi, Yuxi Lin, Masatomo So, Mihály Józsi, Gitta Schlosser, Young-Ho Lee, Károly Liliom, Yuji Goto, and József Kardos
- Subjects
amyloidosis ,protein aggregation ,β2-microglobulin ,dialysis-related amyloidosis ,protein stability ,ion-pairs ,Biology (General) ,QH301-705.5 - Abstract
β2-microglobulin (β2m), the light chain of the MHC-I complex, is associated with dialysis-related amyloidosis (DRA). Recently, a hereditary systemic amyloidosis was discovered, caused by a naturally occurring D76N β2m variant, which showed a structure remarkably similar to the wild-type (WT) protein, albeit with decreased thermodynamic stability and increased amyloidogenicity. Here, we investigated the role of the D76N mutation in the amyloid formation of β2m by point mutations affecting the Asp76-Lys41 ion-pair of WT β2m and the charge cluster on Asp38. Using a variety of biophysical techniques, we investigated the conformational stability and partial unfolding of the native state of the variants, as well as their amyloidogenic propensity and the stability of amyloid fibrils under various conditions. Furthermore, we studied the intermolecular interactions of WT and mutant proteins with various binding partners that might have in vivo relevance. We found that, relative to WT β2m, the exceptional amyloidogenicity of the pathogenic D76N β2m variant is realized by the deleterious synergy of diverse effects of destabilized native structure, higher sensitivity to negatively charged amphiphilic molecules (e.g., lipids) and polyphosphate, more effective fibril nucleation, higher conformational stability of fibrils, and elevated affinity for extracellular components, including extracellular matrix proteins.
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- 2021
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29. Functional Interplay between P5 and PDI/ERp72 to Drive Protein Folding
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Motonori Matsusaki, Rina Okada, Yuya Tanikawa, Shingo Kanemura, Dai Ito, Yuxi Lin, Mai Watabe, Hiroshi Yamaguchi, Tomohide Saio, Young-Ho Lee, Kenji Inaba, and Masaki Okumura
- Subjects
protein disulfide isomerase family ,disulfide bond ,endoplasmic reticulum ,oxidative folding ,molecular chaperone ,protein-protein interaction ,Biology (General) ,QH301-705.5 - Abstract
P5 is one of protein disulfide isomerase family proteins (PDIs) involved in endoplasmic reticulum (ER) protein quality control that assists oxidative folding, inhibits protein aggregation, and regulates the unfolded protein response. P5 reportedly interacts with other PDIs via intermolecular disulfide bonds in cultured cells, but it remains unclear whether complex formation between P5 and other PDIs is involved in regulating enzymatic and chaperone functions. Herein, we established the far-western blot method to detect non-covalent interactions between P5 and other PDIs and found that PDI and ERp72 are partner proteins of P5. The enzymatic activity of P5-mediated oxidative folding is up-regulated by PDI, while the chaperone activity of P5 is stimulated by ERp72. These findings shed light on the mechanism by which the complex formations among PDIs drive to synergistically accelerate protein folding and prevents aggregation. This knowledge has implications for understanding misfolding-related pathology.
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- 2021
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30. Computational Flow Analysis on a Real Scale Run-of-River Archimedes Screw Turbine with a High Incline Angle
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Dylan Sheneth Edirisinghe, Ho-Seong Yang, Min-Sung Kim, Byung-Ha Kim, Sudath Prasanna Gunawardane, and Young-Ho Lee
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Archimedes screw ,turbine ,hydro ,CFD ,flow field ,Technology - Abstract
The Archimedes screw turbine (AST) is the most sustainable mini-hydropower extraction method that offers number of economic, social, and environmental advantages. Nowadays, many researchers are interested in AST development as it is considered a new technology. Currently, a lot of researchers are conducting experimental testing of the screws, comparing their reliability with computational fluid dynamic (CFD) analyses. Almost all of them are lab-scale testing models that claiming an average 80% efficiency for low pitch angles. In the case of a real site with a small inclination angle, the length of the screw is large enough to cause severe problems, specially related to bending of the screw. Therefore, this research was conducted to analyze the CFD flow field in a real site-scale AST with the maximum possible inclination of 45 degrees. In addition, the design was done without the upper and lower reservoir as it was conceived as a run-of-river flow system. The simulated real scale AST result showed a maximum efficiency of around 82% for a 5.2 m hydraulic head and 0.232 m3/s discharge. Many researchers claim above 80% efficiency for low inclination angle ASTs with reservoirs. This CFD study indicates that even higher inclination angle ASTs can achieve 80% efficiency in run-of-river; real-scale applications.
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- 2021
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31. Synaptonemal complex protein 3 is associated with lymphangiogenesis in non-small cell lung cancer patients with lymph node metastasis
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Haruhisa Kitano, Joon-Yong Chung, Kyung Hee Noh, Young-Ho Lee, Tae Woo Kim, Seok Hyung Lee, Soo-Heang Eo, Hyung Jun Cho, Chel Hun Choi, Shuhei Inoue, Jun Hanaoka, Junya Fukuoka, and Stephen M. Hewitt
- Subjects
SCP3 ,Vascular endothelial growth factor ,Lymphangiogenesis ,Lymph node metastasis ,Non-small cell lung cancer ,Medicine - Abstract
Abstract Background The interaction of vascular endothelial growth factor-C (VEGF-C)/VEGF-D/VEGF receptor-3 is considered to be a major driver of lymphangiogenesis, however the mechanism of this process remains unclear. We aimed to investigate the possible lymphangiogenic significance of synaptonemal complex protein 3 (SCP3) in non-small cell lung cancer (NSCLC). Methods The expression of SCP3, VEGF-C, and VEGF-D were measured and examined a correlation between SCP3 and VEGF-C or VEGF-D in various human lung cancer cell lines. Subsequently, we assessed SCP3, VEGF-A, VEGF-B, VEGF-C, and VEGF-D expression in archival tumor tissues from 89 NSCLC patients with lymph node (LN) metastasis by combined immunohistochemistry with quantitative digital image analysis. Results Positive correlations between SCP3 and VEGF-C expression (R 2 = 0.743) and VEGF-D expression (R 2 = 0.932) were detected in various human lung cancer cell lines. The high expression of SCP3, VEGF-A, VEGF-B, VEGF-C, and VEGF-D were detected in 24 (27.0%), 22 (24.7%), 27 (30.3%), 27 (30.3%), and 24 cases (27.0%), respectively. Notably, SCP3 positively correlated with VEGF-C and VEGF-D expression (for both, P
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- 2017
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32. Data on the potent fibrinolytic effects of the Lumbricus rubellus earthworm and the Perinereis linea lugworm
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Yuanyuan Dong, Young Min Woo, Young-Ho Lee, Mee Young Ahn, Dong-Guen Lee, Sang-Hyeon Lee, Jong-Myung Ha, Chan-Il Park, and Andre Kim
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
There is technology available for anti-thrombus with earthworms, but the procedure is complex and extracts protein with inferior purity. In order to develop a simplified process with a stronger purity of protease, we investigated the Lumbricus rubellus earthworm and Perinereis linea lugworm. We purified water extracts cut off at 10 kDa of molecular weight using ultrafiltration because proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. We purified EW1 (raw earthworm extract), EW2 (molecular weight (m.w) > 10 kDa of earthworm extract), and EW3 (m.w 10 kDa), and LW3 (m.w EW1 > EW3 > LW2 > LW1 > LW3. In particular, EW2 and LW2 showed a potent fibrinolytic effect in two different worm specimens. The protein content of each sample was detected as 2.34 (EW1), 3.03 (EW2), 2.80 (LW1), 3.71 (LW2) mg/ml respectively, and their molecular weights were measured using SDS-PAGE. The samples contained the following amounts of total fatty acids: EW1, 3.61%; EW2, 0.48%; LW1, 4.96%; and LW2, 0.23%.We developed a process to increase the thrombolytic effect with a higher purity protein. The study results demonstrate this procedure and provide basic data for developing an anti-thrombolytic agent. Keywords: Lumbricus rubellus, Perinereis linea, Fibrinolytic effect, Fatty acid
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- 2019
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33. Anti-inflammatory effects of the combined extracts of Achyranthes japonica nakai and Aralia continentalis kitagawa in vitro and in vivo
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Young Min Woo, Ok Ju Kim, Eun Sol Jo, Su Jin Kim, Young-Ho Lee, Mee Young Ahn, Sang-Hyeon Lee, Jong-Myung Ha, and Andre Kim
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Science (General) ,Q1-390 - Abstract
This study investigated the anti-inflammatory effects of mixed extracts of Achyranthes japonica Nakai (AJ) and Aralia continentalis Kitagawa (AC) (ratios of 1:2, 1:3, 1:5, 2:1, 3:1 and 5:1) on RAW264.7 macrophages and evaluated the anti-inflammatory effects of the mixed extracts of AJ and AC by measuring IL-1β, IL-6, and TNFα using the ELISA kit assay. In particular, the formation of nitric oxide (NO) was found to decrease in the group treated with the combined extracts of AJ and AC at all ratios. In particular, extracts of ratio of 2:1 (AJ:AC) deceased the formation of NO level that is approximately 60% of the group treated with only lipopolysaccharide (LPS). Also, extracts of ratio of 2:1 (AJ:AC) reduced the production of IL-1β, IL-6, TNFα and PGE2 with statistical significance. Volunteers over the age of 50 who complain of discomfort in knee joints were selected as the experimental subjects. The subjects took daily administration of 2000 mg of the combined extracts of ratio of 2:1 (AJ:AC) for 12 weeks. A survey (VAS (Visual Analog Scale), WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index)) was conducted after the 12 weeks of oral administration. The experimental group showed the change between each visit and baseline time compared with the control group. In the intention-to-treat (ITT) analysis, VAS score and WOMAC stiffness score decreased significantly. And the WOMAC total score and function score tended to decrease. In the per-protocol (PP) analysis, the WOMAC stiffness score was significantly decreased and the VAS and WOMAC total and function scores were decreased. There was no significant difference in all parameters of ITT and PP in radiological examinations.
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- 2019
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34. Ca2+ Regulates ERp57-Calnexin Complex Formation
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Yuya Tanikawa, Shingo Kanemura, Dai Ito, Yuxi Lin, Motonori Matsusaki, Kimiko Kuroki, Hiroshi Yamaguchi, Katsumi Maenaka, Young-Ho Lee, Kenji Inaba, and Masaki Okumura
- Subjects
endoplasmic reticulum ,oxidative folding ,chaperone ,calnexin ,ERp57 ,human leukocyte antigen ,Organic chemistry ,QD241-441 - Abstract
ERp57, a member of the protein disulfide isomerase family, is a ubiquitous disulfide catalyst that functions in the oxidative folding of various clients in the mammalian endoplasmic reticulum (ER). In concert with ER lectin-like chaperones calnexin and calreticulin (CNX/CRT), ERp57 functions in virtually all folding stages from co-translation to post-translation, and thus plays a critical role in maintaining protein homeostasis, with direct implication for pathology. Here, we present mechanisms by which Ca2+ regulates the formation of the ERp57-calnexin complex. Biochemical and isothermal titration calorimetry analyses revealed that ERp57 strongly interacts with CNX via a non-covalent bond in the absence of Ca2+. The ERp57-CNX complex not only promoted the oxidative folding of human leukocyte antigen heavy chains, but also inhibited client aggregation. These results suggest that this complex performs both enzymatic and chaperoning functions under abnormal physiological conditions, such as Ca2+ depletion, to effectively guide proper oxidative protein folding. The findings shed light on the molecular mechanisms underpinning crosstalk between the chaperone network and Ca2+.
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- 2021
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35. 17O NMR Spectroscopy: A Novel Probe for Characterizing Protein Structure and Folding
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Srinivasan Muniyappan, Yuxi Lin, Young-Ho Lee, and Jin Hae Kim
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17O NMR spectroscopy ,protein structures ,protein folding ,oxygen-17 ,Biology (General) ,QH301-705.5 - Abstract
Oxygen is a key atom that maintains biomolecular structures, regulates various physiological processes, and mediates various biomolecular interactions. Oxygen-17 (17O), therefore, has been proposed as a useful probe that can provide detailed information about various physicochemical features of proteins. This is attributed to the facts that (1) 17O is an active isotope for nuclear magnetic resonance (NMR) spectroscopic approaches; (2) NMR spectroscopy is one of the most suitable tools for characterizing the structural and dynamical features of biomolecules under native-like conditions; and (3) oxygen atoms are frequently involved in essential hydrogen bonds for the structural and functional integrity of proteins or related biomolecules. Although 17O NMR spectroscopic investigations of biomolecules have been considerably hampered due to low natural abundance and the quadruple characteristics of the 17O nucleus, recent theoretical and technical developments have revolutionized this methodology to be optimally poised as a unique and widely applicable tool for determining protein structure and dynamics. In this review, we recapitulate recent developments in 17O NMR spectroscopy to characterize protein structure and folding. In addition, we discuss the highly promising advantages of this methodology over other techniques and explain why further technical and experimental advancements are highly desired.
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- 2021
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36. Treatment Outcomes of Pediatric Acute Myeloid Leukemia in the Yeungnam Region: A Multicenter Retrospective Study of the Study Alliance of Yeungnam Pediatric Hematology–Oncology (SAYPH)
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Jae Min Lee, Eu Jeen Yang, Kyung Mi Park, Young-Ho Lee, Heewon Chueh, Jeong Ok Hah, Ji Kyoung Park, Jae Young Lim, Eun Sil Park, Sang Kyu Park, Heung Sik Kim, Ye Jee Shim, Jeong A. Park, Eun Jin Choi, Kun Soo Lee, Ji Yoon Kim, and Young Tak Lim
- Subjects
acute myeloid leukemia ,hematopoietic stem cell transplantation ,prognosis ,pediatric ,childhood ,Korea ,Pediatrics ,RJ1-570 - Abstract
Acute myeloid leukemia (AML) is the second most common pediatric leukemia, with a survival rate of 70%. In this retrospective study, we evaluated the treatment outcomes of pediatric AML among 144 patients diagnosed between 2000 and 2013. After induction, 80.6% of patients achieved complete remission (CR). The 5-year overall survival (OS) and event-free survival (EFS) rates were 58.8 ± 4.2% and 49.8 ± 4.2%, respectively. Based on the response to induction therapy, the 5-year OS was 66.9 ± 5.7% in patients with CR (p < 0.001). Ninety-nine patients with CR after induction therapy were examined, and their 5-year OS and EFS were 66.4 ± 4.9% and 56.3 ± 5.1%, respectively. The 5-year OS rates according to treatment were 59.9 ± 7.4% in the chemotherapy group and 72.3 ± 6.3% in the hematopoietic stem cell transplantation (HSCT) group (p = 0.089). The EFS was 50.1 ± 7.4% in the chemotherapy group and 61.7 ± 6.9% in the HSCT group (p = 0.098). OS and EFS according to cytogenetics were insignificant. Our findings confirmed that the response to induction treatment was important for survival and HSCT had no significant survival benefits compared with those of chemotherapy. Moreover, many early induction deaths under the age of 2 years were observed.
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- 2021
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37. Experimental studies on the flow characteristics in an inclined bend-free OWC device
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Krishnil Ravinesh Ram, Mohammed Rafiuddin Ahmed, Mohammed Asid Zullah, and Young-Ho Lee
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Oscillating water column ,Particle Image Velocimetry ,Wave energy ,Ocean engineering ,TC1501-1800 - Abstract
A bend-free rectangular cross-section OWC device was designed and constructed for studying the effect of inclination on the flow characteristics inside the device. The inclination is meant to reduce reflection of waves and induce higher velocities in the turbine section. Experimental measurements were made in a wave channel where the OWC device was tested. An S-type Pitot tube was used to measure dynamic pressure of air in the turbine section at several inclinations. Particle Image Velocimetry (PIV) was also done to study the flow of both air and water in the OWC device. In order to focus solely on primary energy capture, no turbine was installed in the OWC device. The dynamic pressure readings were analysed for suction and compression stages. Water volume fluctuations inside the capture chamber were also recorded and compared for different inclinations. The result was an increase in the velocity of air flowing in the capture chamber and hence a rise in the kinetic energy available to the turbine. It was found from experimental studies that as the angle of inclination reduced, the velocity of air in the turbine section increased. The lower angles also caused higher run-up and larger volume of water into the capture chamber.
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- 2016
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38. Magnetic Coupling for a 10 kW Tidal Current Turbine: Design and Small Scale Experiments
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In-cheol Kim, Joji Wata, Watchara Tongphong, Jong-Su Yoon, and Young-Ho Lee
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cylindrical air gap magnetic coupling ,marine current turbine ,counter-rotating turbine ,tidal current energy ,Technology - Abstract
This paper presents a coupling design that improves water tightness of a marine current turbine (MCT). The coupling is numerically analyzed and incorporated into the design of an MCT from a previous study. The performance of the MCT with the magnetic coupling is compared to the previous results in small scale turbine experiments. The results show that the new design is water tight and has lower mechanical losses when compared with previous results. The new turbine has increased maximum power output (from 116 W to 122 W) and hydrodynamic coefficient of power (Previously 0.45 to 0.46). Using these results, the coupling design is scaled for a 10 kW MCT and further analyzed by finite element analysis. The results obtained show that the magnetic coupling is capable of withstanding the combined weight of the hub and blade assembly. The results in this study will be used for developing a prototype for deployment in real seas.
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- 2020
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39. The MAO Inhibitor Tranylcypromine Alters LPS- and Aβ-Mediated Neuroinflammatory Responses in Wild-type Mice and a Mouse Model of AD
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HyunHee Park, Kyung-Min Han, Hyongjun Jeon, Ji-Soo Lee, Hyunju Lee, Seong Gak Jeon, Jin-Hee Park, Yu Gyung Kim, Yuxi Lin, Young-Ho Lee, Yun Ha Jeong, and Hyang-Sook Hoe
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neuroinflammation ,MAO inhibitor ,microglia ,amyloid beta ,LPS ,Cytology ,QH573-671 - Abstract
Monoamine oxidase (MAO) has been implicated in neuroinflammation, and therapies targeting MAO are of interest for neurodegenerative diseases. The small-molecule drug tranylcypromine, an inhibitor of MAO, is currently used as an antidepressant and in the treatment of cancer. However, whether tranylcypromine can regulate LPS- and/or Aβ-induced neuroinflammation in the brain has not been well-studied. In the present study, we found that tranylcypromine selectively altered LPS-induced proinflammatory cytokine levels in BV2 microglial cells but not primary astrocytes. In addition, tranylcypromine modulated LPS-mediated TLR4/ERK/STAT3 signaling to alter neuroinflammatory responses in BV2 microglial cells. Importantly, tranylcypromine significantly reduced microglial activation as well as proinflammatory cytokine levels in LPS-injected wild-type mice. Moreover, injection of tranylcypromine in 5xFAD mice (a mouse model of AD) significantly decreased microglial activation but had smaller effects on astrocyte activation. Taken together, our results suggest that tranylcypromine can suppress LPS- and Aβ-induced neuroinflammatory responses in vitro and in vivo.
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- 2020
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40. Vasodilatory Effect of Phellinus linteus Extract in Rat Mesenteric Arteries
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Youngin Kwon, Chae Eun Haam, Seonhee Byeon, Soo Jung Choi, Dong-Hoon Shin, Soo-Kyoung Choi, and Young-Ho Lee
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Phellinus linteus ,Kca channels ,vasodilation ,relaxation ,mesenteric artery ,Organic chemistry ,QD241-441 - Abstract
Phellinus linteus is a well-known medicinal mushroom that is widely used in Asian countries. In several experimental models, Phellinus linteus extracts were reported to have various biological effects, including anti-inflammatory, anti-cancer, hepatoprotective, anti-diabetic, neuroprotective, and anti-angiogenic activity. In the present study, several bioactive compounds, including palmitic acid ethyl ester and linoleic acid, were identified in Phellinus linteus. The intermediate-conductance calcium-activated potassium channel (IKCa) plays an important role in the regulation of the vascular smooth muscle cells’ (VSMCs) contraction and relaxation. The activation of the IKCa channel causes the hyperpolarization and relaxation of VSMCs. To examine whether Phellinus linteus extract causes vasodilation in the mesenteric arteries of rats, we measured the isometric tension using a wire myograph. After the arteries were pre-contracted with U46619 (a thromboxane analogue, 1 µM), Phellinus linteus extract was administered. The Phellinus linteus extract induced vasodilation in a dose-dependent manner, which was independent of the endothelium. To further investigate the mechanism, we used the non-selective K+ channel blocker tetraethylammonium (TEA). TEA significantly abolished Phellinus linteus extract-induced vasodilation. Thus, we tested three different types of K+ channel blockers: iberiotoxin (BKca channel blocker), apamin (SKca channel blocker), and charybdotoxin (IKca channel blocker). Charybdotoxin significantly inhibited Phellinus linteus extract-induced relaxation, while there was no effect from apamin and iberiotoxin. Membrane potential was measured using the voltage-sensitive dye bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC4(3)) in the primary isolated vascular smooth muscle cells (VSMCs). We found that the Phellinus linteus extract induced hyperpolarization of VSMCs, which is associated with a reduced phosphorylation level of 20 KDa myosin light chain (MLC20).
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- 2020
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41. Mononuclear cells from the cord blood and granulocytecolony stimulating factor-mobilized peripheral blood: is there a potential for treatment of cerebral palsy?
- Author
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Hani Koh, Kyoujung Hwang, Hae-Young Lim, Yong-Joo Kim, and Young-Ho Lee
- Subjects
neurotrophic factors ,inflammatory cytokines ,cord blood ,G-CSF mobilized peripheral blood ,mononuclear cell ,cerebral palsy ,children ,neural regeneration ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
To investigate a possible therapeutic mechanism of cell therapy in the field of cerebral palsy using granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (mPBMCs), we compared the expression of inflammatory cytokines and neurotrophic factors in PBMCs and mPBMCs from children with cerebral palsy to those from healthy adult donors and to cord blood mononuclear cells donated from healthy newborns. No significant differences in expression of neurotrophic factors were found between PBMCs and mPBMCs. However, in cerebral palsy children, the expression of interleukin-6 was significantly increased in mPBMCs as compared to PBMCs, and the expression of interleukin-3 was significantly decreased in mPBMCs as compared to PBMCs. In healthy adults, the expression levels of both interleukin-1β and interleukin-6 were significantly increased in mPBMCs as compared to PBMCs. The expression of brain-derived neurotrophic factors in mPBMC from cerebral palsy children was significantly higher than that in the cord blood or mPBMCs from healthy adults. The expression of G-CSF in mPBMCs from cerebral palsy children was comparable to that in the cord blood but significantly higher than that in mPBMCs from healthy adults. Lower expression of pro-inflammatory cytokines (interleukin-1β, interleukin-3, and -6) and higher expression of anti-inflammatory cytokines (interleukin-8 and interleukin-9) were observed from the cord blood and mPBMCs from cerebral palsy children rather than from healthy adults. These findings indicate that mPBMCs from cerebral palsy and cord blood mononuclear cells from healthy newborns have the potential to become seed cells for treatment of cerebral palsy.
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- 2015
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42. Dacryocystocele on prenatal ultrasonography: diagnosis and postnatal outcomes
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Young-Hwa Kim, Yu-Jin Lee, Mi Jin Song, Byoung Hee Han, Young-Ho Lee, and Kyung Sang Lee
- Subjects
Fetus ,Ultrasonography ,Congenital abnormalities ,Lacrimal duct obstruction ,Medical technology ,R855-855.5 - Abstract
Purpose: To report the incidence of dacryocystoceles detected by prenatal ultrasonography (US) and their postnatal outcomes and to determine the factors associated with the postnatal persistence of dacryocystoceles at birth. Methods: We retrospectively reviewed the prenatal US database at our institution for the period between January 2012 and December 2013. The medical records of women who had fetuses diagnosed with dacryocystocel larger than 5 mm were reviewed for maternal age, gestational age (GA) at detection, size and side of the dacryocystoceles, delivery, and postnatal information, such as GA at delivery, delivery mode, and gender of the neonate. Results: A total of 49 singletons were diagnosed with a dacryocystocele on prenatal US, yielding an overall incidence of 0.43%. The incidence of dacryocystoceles was the highest at the GA of 27 weeks and decreased toward term. Of the 49 fetuses including three of undeter mined gender, 25 (54%) were female. The mean GA at first detection was 31.2 weeks. The dacryocystocele was unilateral in 29 cases, with a mean maximum diameter of 7 mm. Spontaneous resolution at birth was documented in 35 out of 46 neonates (76%), including six with prenatal resolution. Multivariate analysis demonstrated that GA at delivery was a significant predictor of the postnatal persistence of dacryocystoceles (P=0.045). Conclusion: The overall incidence of prenatal dacryocystoceles was 0.43%; the incidence was higher in the early third trimester and decreased thereafter. Prenatal dacryocystoceles resolved in 76% of the patients at birth, and the GA at delivery was a significant predictor of postnatal persistence.
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- 2015
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43. Healthcare Decision Support System for Administration of Chronic Diseases
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Ji-In Woo, Jung-Gi Yang, Young-Ho Lee, and Un-Gu Kang
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clinical decision support systems ,expert systems ,knowledge bases ,personal health records ,chronic disease ,Computer applications to medicine. Medical informatics ,R858-859.7 - Abstract
ObjectivesA healthcare decision-making support model and rule management system is proposed based on a personalized rule-based intelligent concept, to effectively manage chronic diseases.MethodsA Web service was built using a standard message transfer protocol for interoperability of personal health records among healthcare institutions. An intelligent decision service is provided that analyzes data using a service-oriented healthcare rule inference function and machine-learning platform; the rules are extensively compiled by physicians through a developmental user interface that enables knowledge base construction, modification, and integration. Further, screening results are visualized for the self-intuitive understanding of personal health status by patients.ResultsA recommendation message is output through the Web service by receiving patient information from the hospital information recording system and object attribute values as input factors. The proposed system can verify patient behavior by acting as an intellectualized backbone of chronic diseases management; further, it supports self-management and scheduling of screening.ConclusionsChronic patients can continuously receive active recommendations related to their healthcare through the rule management system, and they can model the system by acting as decision makers in diseases management; secondary diseases can be prevented and health management can be performed by reference to patient-specific lifestyle guidelines.
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- 2014
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44. Clinical utilization of cord blood over human health: experience of stem cell transplantation and cell therapy using cord blood in Korea
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Young-Ho Lee
- Subjects
Cord blood ,Transplantation ,Cell therapy ,Pediatrics ,RJ1-570 - Abstract
Cord blood (CB) has been used as an important and ethical source for hematopoietic stem cell transplantation (SCT) as well as cell therapy by manufacturing mesenchymal stem cell, induced pleuripotential stem cell or just isolating mononuclear cell from CB. Recently, the application of cell-based therapy using CB has expanded its clinical utility, particularly, by using autologous CB in children with refractory diseases. For these purposes, CB has been stored worldwide since mid-1990. In this review, I would like to briefly present the historical development of clinical uses of CB in the fields of SCT and cell therapy, particularly to review the experiences in Korea. Furthermore, I would touch the recent banking status of CB.
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- 2014
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45. Urine proteomics for discovery of improved diagnostic markers of Kawasaki disease
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Alex Kentsis, Andrew Shulman, Saima Ahmed, Eileen Brennan, Michael C. Monuteaux, Young‐Ho Lee, Susan Lipsett, Joao A. Paulo, Fatma Dedeoglu, Robert Fuhlbrigge, Richard Bachur, Gary Bradwin, Moshe Arditi, Robert P. Sundel, Jane W. Newburger, Hanno Steen, and Susan Kim
- Subjects
biomarker ,Kawasaki disease ,mass spectrometry ,vasculitis ,urinary proteome ,Medicine (General) ,R5-920 ,Genetics ,QH426-470 - Abstract
Abstract Kawasaki disease (KD) is a systemic vasculitis of unknown etiology. Absence of definitive diagnostic markers limits the accuracy of clinical evaluations of suspected KD with significant increases in morbidity. In turn, incomplete understanding of its molecular pathogenesis hinders the identification of rational targets needed to improve therapy. We used high‐accuracy mass spectrometry proteomics to analyse over 2000 unique proteins in clinical urine specimens of patients with KD. We discovered that urine proteomes of patients with KD, but not those with mimicking conditions, were enriched for markers of cellular injury such as filamin and talin, immune regulators such as complement regulator CSMD3, immune pattern recognition receptor muclin, and immune cytokine protease meprin A. Significant elevations of filamin C and meprin A were detected in both the serum and urine in two independent cohorts of patients with KD, comprised of a total of 236 patients. Meprin A and filamin C exhibited superior diagnostic performance as compared to currently used markers of disease in a blinded case‐control study of 107 patients with suspected KD, with receiver operating characteristic areas under the curve of 0.98 (95% confidence intervals [CI] of 0.97–1 and 0.95–1, respectively). Notably, meprin A was enriched in the coronary artery lesions of a mouse model of KD. In all, urine proteome profiles revealed novel candidate molecular markers of KD, including filamin C and meprin A that exhibit excellent diagnostic performance. These disease markers may improve the diagnostic accuracy of clinical evaluations of children with suspected KD, lead to the identification of novel therapeutic targets, and allow the development of a biological classification of Kawasaki disease.
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- 2012
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46. Slitrk missense mutations associated with neuropsychiatric disorders distinctively impair Slitrk trafficking and synapse formation
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Hyeyeon Kang, Kyung Ah Han, Seong Youn Won, Ho Min Kim, Young-Ho Lee, Jaewon Ko, and JI WON UM
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Schizophrenia ,synapse formation ,Tourette’s Syndrome ,transmembrane protein ,Slitrks ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Slitrks are a six-member family of synapse organizers that control excitatory and inhibitory synapse formation by forming trans-synaptic adhesions with LAR receptor protein tyrosine phosphatases (PTPs). Intriguingly, genetic mutations of Slitrks have been associated with a multitude of neuropsychiatric disorders. However, nothing is known about the neuronal and synaptic consequences of these mutations. Here, we report the structural and functional effects on synapses of various rare de novo mutations identified in patients with schizophrenia or Tourette syndrome. A number of single amino acid substitutions in Slitrk1 (N400I or T418S) or Slitrk4 (V206I or I578V) reduced their surface expression levels. These substitutions impaired glycosylation of Slitrks expressed in HEK293T cells, caused retention of Slitrks in the endoplasmic reticulum and cis-Golgi compartment in COS-7 cells and neurons, and abolished Slitrk binding to PTPδ. Furthermore, these substitutions eliminated the synapse-inducing activity of Slitrks, abolishing their functional effects on synapse density in cultured neurons. Strikingly, a valine-to-methionine mutation in Slitrk2 (V89M) compromised synapse formation activity in cultured neuron, without affecting surface transport, expression, or synapse-inducing activity in coculture assays. Similar deleterious effects were observed upon introduction of the corresponding valine-to-methionine mutation into Slitrk1 (V85M), suggesting that this conserved valine residue plays a key role in maintaining the synaptic functions of Slitrks. Collectively, these data indicate that inactivation of distinct cellular mechanisms caused by specific Slitrk dysfunctions may underlie Slitrk-associated neuropsychiatric disorders in humans, and provide a robust cellular readout for the development of knowledge-based therapies.
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- 2016
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47. Gene Silencing and Haploinsufficiency of Csk Increase Blood Pressure.
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Hyeon-Ju Lee, Ji-One Kang, Sung-Moon Kim, Su-Min Ji, So-Yon Park, Marina E Kim, Baigalmaa Jigden, Ji Eun Lim, Sue-Yun Hwang, Young-Ho Lee, and Bermseok Oh
- Subjects
Medicine ,Science - Abstract
Recent genome-wide association studies have identified 33 human genetic loci that influence blood pressure. The 15q24 locus is one such locus that has been confirmed in Asians and Europeans. There are 21 genes in the locus within a 1-Mb boundary, but a functional link of these genes to blood pressure has not been reported. We aimed to identify a causative gene for blood pressure change in the 15q24 locus.CSK and ULK3 were selected as candidate genes based on eQTL analysis studies that showed the association between gene transcript levels and the lead SNP (rs1378942). Injection of siRNAs for mouse homologs Csk, Ulk3, and Cyp1a2 (negative control) showed reduced target gene mRNA levels in vivo. However, Csk siRNA only increased blood pressure while Ulk3 and Cyp1a2 siRNA did not change it. Further, blood pressure in Csk+/- heterozygotes was higher than in wild-type, consistent with what we observed in Csk siRNA-injected mice. We confirmed that haploinsufficiency of Csk increased the active form of Src in Csk+/- mice aorta. We also showed that inhibition of Src by PP2, a Src inhibitor decreased high blood pressure in Csk+/- mice and the active Src in Csk+/- mice aorta and in Csk knock-down vascular smooth muscle cells, suggesting blood pressure regulation by Csk through Src.Our study demonstrates that Csk is a causative gene in the 15q24 locus and regulates blood pressure through Src, and these findings provide a novel therapeutic target for the treatment of hypertension.
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- 2016
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48. Comparison of Vitamin D Levels in Patients with and without Acne: A Case-Control Study Combined with a Randomized Controlled Trial.
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Seul-Ki Lim, Jeong-Min Ha, Young-Ho Lee, Young Lee, Young-Joon Seo, Chang-Deok Kim, Jeung-Hoon Lee, and Myung Im
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Medicine ,Science - Abstract
BACKGROUND:Vitamin D plays an important role in the immune system, and its deficiency has been implicated in various skin diseases, including atopic dermatitis and psoriasis. Acne is a common inflammatory skin disease; however, the association with vitamin D remains unclear. OBJECTIVES:We evaluated vitamin D levels in patients with acne to determine the effect of vitamin D supplementation. METHODS:This study included 80 patients with acne and 80 healthy controls. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured, and demographic data were collected. Vitamin D-deficient patients were treated with oral cholecalciferol at 1000 IU/day for 2 months. RESULTS:Deficiency in 25(OH)D was detected in 48.8% of patients with acne, but in only 22.5% of the healthy controls. The level of 25(OH)D was inversely associated with the severity of acne, and there was a significant negative correlation with inflammatory lesions. In a subsequent trial, improvement in inflammatory lesions was noted after supplementation with vitamin D in 39 acne patients with 25(OH)D deficiency. LIMITATIONS:Limitations of the study include the small number of patients in the supplementation study and the natural fluctuation of acne. CONCLUSIONS:Vitamin D deficiency was more frequent in patients with acne, and serum 25(OH)D levels were inversely correlated with acne severity, especially in patients with inflammatory lesions.
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- 2016
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49. CD4+CD25+FOXP3+ Regulatory T Cells In Allogeneic Hematopoietic Cell Transplantation
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Young-Ho Lee and Muhaimin Rifa'i
- Subjects
Bone Marrow Transplantation ,Regulatory T cells ,CD4+CD25+FOXP3+ ,Biology (General) ,QH301-705.5 - Abstract
CD4+CD25+FOXP3+ regulatory T cells (Treg) require activation through the T cell receptor for function. CD4+CD25+FOXP3+ regulatory T cells are believed to be key players of the immune tolerance network and control the induction and effector phase of the immune system. Although these cells require antigen-specific activation, they are generally able to suppress bystander T cell responses once activated. This raises the possibility that antigen-specific Treg may be useful therapeutically by localizing generalized suppressive activity to tissues expressing select target antigens. Treg can exert a potent suppressive effect on immune effector cells reactive to host antigens and prevent graft versus host disease (GVHD) in allogeneic bone marrow transplantation (BMT). Here, we observed that co-transfer of CD4+CD25+FOXP3+ T cells derived from donor type along with the donor bone marrow cells could control GVHD-like reactions by suppressing effectors cells of host responding to the donor hematopoietic compartment, and resulted in prevention of autoimmunity and rejection. We further demonstrate that CD4+CD25+FOXP3+ regulatory T cells can control immune-based morbidity after allogeneic BMT by suppressing the development of granulocytes cells and increasing the level of B cell expression.
- Published
- 2011
50. Experimental and Numerical Studies on a Low Reynolds Number Airfoil for Wind Turbine Blades
- Author
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M. Rafiuddin AHMED, Sumesh NARAYAN, M. Asid ZULLAH, and Young-Ho LEE
- Subjects
low reynolds number airfoil ,pressure distribution ,lift ,drag ,wind turbine ,turbulence intensity ,Science (General) ,Q1-390 ,Technology - Abstract
Testing of a low Reynolds number airfoil designed for low speed horizontal axis wind turbine (HAWT) blades was performed to study its aerodynamic characteristics. Experiments were conducted at Reynolds numbers (Re) of 38,000 to 200,000 at angles of attack from -2° to 20°. The airfoil geometry was chosen after testing a number of profiles with XFOIL software. The pressure distribution, lift and drag coefficients and the flow characteristics were also studied with ANSYS-CFX software. The freestream turbulence level was increased from 1% to 5% and 10% which shifted the transition point on the upper surface upstream, resulting in increased skin friction drag for lower angles of attack due to a larger turbulent boundary layer region. The slope of the lift curve did not change much at higher turbulence levels; however, for higher angles of attack, the separation from the upper surface was delayed resulting in an increase in lift and a reduction in drag. The lift to drag ratio increased by 8% to 15% as a result of increasing the turbulence level in the angles of attack-range of interest.
- Published
- 2011
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