72 results on '"Da Un Jeong"'
Search Results
2. Proarrhythmic risk assessment of drugs by <scp> d V m </scp> /d t shapes using the convolutional neural network
- Author
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Da Un Jeong, Yedam Yoo, Aroli Marcellinus, Ki‐Suk Kim, and Ki Moo Lim
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Modeling and Simulation ,Pharmacology (medical) - Published
- 2022
3. Effect of subject exploration using writing strategies on writing corpus in high school students
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Da-Un Jeong
- Published
- 2022
4. Impairment of Decidualization of Endometrial Stromal Cells by hsa-miR-375 Through NOX4 Targeting
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Seong-Lan Yu, Da-Un Jeong, Yujin Kang, Tae-Hyun Kim, Sung Ki Lee, Ae-Ra Han, Jaeku Kang, and Seok-Rae Park
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Endometrium ,MicroRNAs ,NADPH Oxidase 4 ,Infertility ,Decidua ,Humans ,Obstetrics and Gynecology ,Female ,Stromal Cells ,Reactive Oxygen Species ,Cells, Cultured - Abstract
Decidualization of the endometrial stromal cells (ESCs) is essential for successful embryo implantation. It involves the transformation of fibroblastic cells into epithelial-like cells that secrete cytokines, growth factors, and proteins necessary for implantation. Previous studies have revealed altered expression of miR-375 in the endometrium of patients with recurrent implantation failure and the ectopic stromal cells of patients with endometriosis. However, the exact molecular mechanisms, particularly the role of microRNAs (miRNAs) in the regulation of decidualization, remain elusive. In this study, we investigated whether decidualization is affected by miR-375 and its potential target(s). The findings demonstrated the downregulation of the expression of miR-375 in the secretory phase compared to its expression in the proliferative phase of the endometrium in normal donors. In contrast, it was upregulated in the secretory phase of the endometrium in infertility patients. Furthermore, during decidualization of ESCs in vitro, overexpression of miR-375 significantly reduced the transcript-level expression of forkhead box protein O1 (FOXO1), prolactin (PRL), and insulin-like growth factor binding protein-1 (IGFBP1), the well-known decidual cell markers. Overexpression of miR-375 also resulted in reduced decidualization-derived intracellular and mitochondrial reactive oxygen species (ROS) levels. Using the luciferase assay, we confirmed that NADPH oxidase 4 (NOX4) is a direct target of miR-375. Collectively, the study showed that the miR-375-mediated NOX4 downregulation reduced ROS production and attenuated the decidualization of ESCs. It provides evidence that miR-375 is a negative regulator of decidualization and could serve as a potential target for combating infertility.
- Published
- 2022
5. qInward variability-based in-silico proarrhythmic risk assessment of drugs using deep learning model
- Author
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Da Un Jeong, Nurul Qashri Mahardika T, Aroli Marcellinus, and Ki Moo Lim
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Physiology ,Physiology (medical) - Abstract
Many researchers have suggested evaluation methods and Torsades de Pointes (TdP) metrics to assess the proarrhythmic risk of a drug based on the in silico simulation, as part of the Comprehensive in-vitro Proarrhythmia Assay (CiPA) project. In the previous study, we validated the robustness of 12 in silico features using the ordinal logistic regression (OLR) model by comparing the classification performances of metrics according to the in-vitro experimental datasets used; however, the OLR model using 12 in silico features did not provide desirable results. This study proposed a convolutional neural network (CNN) model using the variability of promising in silico TdP metrics hypothesizing that the variability of in silico features based on beats has more information than the single value of in silico features. We performed the action potential (AP) simulation using a human ventricular myocyte model to calculate seven in silico features representing the electrophysiological cell states of drug effects over 1,000 beats: qNet, qInward, intracellular calcium duration at returning to 50% baseline (CaD50) and 90% baseline (CaD90), AP duration at 50% repolarization (APD50) and 90% repolarization (APD90), and dVm/dtMax_repol. The proposed CNN classifier was trained using 12 train drugs and tested using 16 test drugs among CiPA drugs. The torsadogenic risk of drugs was classified as high, intermediate, and low risks. We determined the CNN classifier by comparing the classification performance according to the variabilities of seven in silico biomarkers computed from the in silico drug simulation using the Chantest dataset. The proposed CNN classifier performed the best when using qInward variability to classify the TdP-risk drugs with 0.94 AUC for high risk and 0.93 AUC for low risk. In addition, the final CNN classifier was validated using the qInward variability obtained after merging three in-vitro datasets, but the model performance decreased to a moderate level of 0.75 and 0.78 AUC. These results suggest the need for the proposed CNN model to be trained and tested using various types of drugs.
- Published
- 2022
6. Sensitivity Analysis of Cardiac Alternans and Tachyarrhythmia to Ion Channel Conductance Using Population Modeling
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Da Un Jeong, Aroli Marcellinus, and Ki Moo Lim
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cardiac alternans ,tachyarrhythmia ,population modeling ,sensitivity analysis ,Bioengineering - Abstract
Action potential duration (APD) alternans, an alternating phenomenon between action potentials in cardiomyocytes, causes heart arrhythmia when the heart rate is high. However, some of the APD alternans observed in clinical trials occurs under slow heart rate conditions of 100 to 120 bpm, increasing the likelihood of heart arrhythmias such as atrial fibrillation. Advanced studies have identified the occurrence of this type of APD alternans in terms of electrophysiological ion channel currents in cells. However, they only identified physiological phenomena, such as action potential due to random changes in a particular ion channel’s conductivity through ion models specializing in specific ion channel currents. In this study, we performed parameter sensitivity analysis via population modeling using a validated human ventricular physiology model to check the sensitivity of APD alternans to ion channel conductances. Through population modeling, we expressed the changes in alternans onset cycle length (AOCL) and mean APD in AOCL (AO meanAPD) according to the variations in ion channel conductance. Finally, we identified the ion channel that maximally affected the occurrence of APD alternans. AOCL and AO meanAPD were sensitive to changes in the plateau Ca2+ current. Accordingly, it was expected that APD alternans would be vulnerable to changes in intracellular calcium concentration.
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- 2022
- Full Text
- View/download PDF
7. The miR-182-5p/NDRG1 Axis Controls Endometrial Receptivity through the NF-κB/ZEB1/E-Cadherin Pathway
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Seong-Lan Yu, Yujin Kang, Da-Un Jeong, Dong Chul Lee, Hye Jin Jeon, Tae-Hyun Kim, Sung Ki Lee, Ae Ra Han, Jaeku Kang, and Seok-Rae Park
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Organic Chemistry ,NF-kappa B ,Zinc Finger E-box-Binding Homeobox 1 ,General Medicine ,Cadherins ,Catalysis ,Computer Science Applications ,Inorganic Chemistry ,Endometrium ,MicroRNAs ,endometrial receptivity ,miR-182-5p ,NDRG1 ,NF-κΒ/ZEB1/E-cadherin pathway ,Pregnancy ,Humans ,Female ,Embryo Implantation ,Physical and Theoretical Chemistry ,Molecular Biology ,Infertility, Female ,Spectroscopy ,Biomarkers - Abstract
Endometrial receptivity is essential for successful pregnancy, and its impairment is a major cause of embryo-implantation failure. MicroRNAs (miRNAs) that regulate epigenetic modifications have been associated with endometrial receptivity. However, the molecular mechanisms whereby miRNAs regulate endometrial receptivity remain unclear. Therefore, we investigated whether miR-182 and its potential targets influence trophoblast cell attachment. miR-182 was expressed at lower levels in the secretory phase than in the proliferative phase of endometrium tissues from fertile donors. However, miR-182 expression was upregulated during the secretory phase in infertile women. Transfecting a synthetic miR-182-5p mimic decreased spheroid attachment of human JAr choriocarcinoma cells and E-cadherin expression (which is important for endometrial receptivity). miR-182-5p also downregulated N-Myc downstream regulated 1 (NDRG1), which was studied further. NDRG1 was upregulated in the secretory phase of the endometrium tissues and induced E-cadherin expression through the nuclear factor-κΒ (NF-κΒ)/zinc finger E-box binding homeobox 1 (ZEB1) signaling pathway. NDRG1-overexpressing or -depleted cells showed altered attachment rates of JAr spheroids. Collectively, our findings indicate that miR-182-5p-mediated NDRG1 downregulation impaired embryo implantation by upregulating the NF-κΒ/ZEB1/E-cadherin pathway. Hence, miR-182-5p is a potential biomarker for negative selection in endometrial receptivity and a therapeutic target for successful embryo implantation.
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- 2022
- Full Text
- View/download PDF
8. Validation of in silico biomarkers for drug screening through ordinal logistic regression
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Da Un Jeong, Rakha Zharfarizqi Danadibrata, Aroli Marcellinus, and Ki Moo Lim
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Physiology ,Physiology (medical) - Abstract
Since the Comprehensive in vitro Proarrhythmia Assay (CiPA) initiation, many studies have suggested various in silico features based on ionic charges, action potentials (AP), or intracellular calcium (Ca) to assess proarrhythmic risk. These in silico features are computed through electrophysiological simulations using in vitro experimental datasets as input, therefore changing with the quality of in vitro experimental data; however, research to validate the robustness of in silico features for proarrhythmic risk assessment of drugs depending on in vitro datasets has not been conducted. This study aims to verify the availability of in silico features commonly used in assessing the cardiac toxicity of drugs through an ordinal logistic regression model and three in vitro datasets measured under different experimental environments and with different purposes. We performed in silico drug simulations using the Tomek-Ohara Rudy (ToR-ORD) ventricular myocyte model and computed 12 in silico features comprising six AP features, four Ca features, and two ion charge features, which reflected the effect and characteristics of each in vitro data for CiPA 28 drugs. We then compared the classific performances of ordinal logistic regressions according to these 12 in silico features and used in vitro datasets to validate which in silico feature is the best for assessing the proarrhythmic risk of drugs at high, intermediate, and low levels. All 12 in silico features helped determine high-risky torsadogenic drugs, regardless of the in vitro datasets used in the in silico simulation as input. In the three types of in silico features, AP features were the most reliable for determining the three Torsade de Pointes (TdP) risk standards. Among AP features, AP duration at 50% repolarization (APD50) was the best when individually using in silico features per in vitro dataset. In contrast, the AP repolarization velocity (dVm/dtMax_repol) was the best when merging all in silico features computed through three in vitro datasets.
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- 2022
9. Validation of
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Da Un, Jeong, Rakha Zharfarizqi, Danadibrata, Aroli, Marcellinus, and Ki Moo, Lim
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Since the Comprehensive
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- 2022
10. Analysis of misconceptions in the writing process: Focusing on non-literary reading appreciation texts linked to integrated curriculum
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Da-un Jeong
- Published
- 2021
11. Combined deep CNN–LSTM network-based multitasking learning architecture for noninvasive continuous blood pressure estimation using difference in ECG-PPG features
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Ki Moo Lim and Da Un Jeong
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Databases, Factual ,Computer science ,Science ,Blood Pressure ,02 engineering and technology ,Signal ,Article ,030218 nuclear medicine & medical imaging ,Machine Learning ,03 medical and health sciences ,0302 clinical medicine ,Heart Rate ,Photoplethysmogram ,0202 electrical engineering, electronic engineering, information engineering ,Humans ,Human multitasking ,Preprocessor ,Photoplethysmography ,Deep cnn ,Multidisciplinary ,Pulse (signal processing) ,business.industry ,Health care ,Models, Cardiovascular ,Blood Pressure Determination ,Pattern recognition ,Blood pressure ,Feature (computer vision) ,Medicine ,020201 artificial intelligence & image processing ,Artificial intelligence ,business ,Biomedical engineering - Abstract
The pulse arrival time (PAT), the difference between the R-peak time of electrocardiogram (ECG) signal and the systolic peak of photoplethysmography (PPG) signal, is an indicator that enables noninvasive and continuous blood pressure estimation. However, it is difficult to accurately measure PAT from ECG and PPG signals because they have inconsistent shapes owing to patient-specific physical characteristics, pathological conditions, and movements. Accordingly, complex preprocessing is required to estimate blood pressure based on PAT. In this paper, as an alternative solution, we propose a noninvasive continuous algorithm using the difference between ECG and PPG as a new feature that can include PAT information. The proposed algorithm is a deep CNN–LSTM-based multitasking machine learning model that outputs simultaneous prediction results of systolic (SBP) and diastolic blood pressures (DBP). We used a total of 48 patients on the PhysioNet website by splitting them into 38 patients for training and 10 patients for testing. The prediction accuracies of SBP and DBP were 0.0 ± 1.6 mmHg and 0.2 ± 1.3 mmHg, respectively. Even though the proposed model was assessed with only 10 patients, this result was satisfied with three guidelines, which are the BHS, AAMI, and IEEE standards for blood pressure measurement devices.
- Published
- 2021
12. Proarrhythmic risk assessment of drugs by dV
- Author
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Da Un, Jeong, Yedam, Yoo, Aroli, Marcellinus, Ki-Suk, Kim, and Ki Moo, Lim
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DNA-Binding Proteins ,Torsades de Pointes ,Humans ,Computer Simulation ,Neural Networks, Computer ,Risk Assessment - Abstract
Comprehensive in vitro Proarrhythmia Assay (CiPA) projects for assessing proarrhythmic drugs suggested a logistic regression model using qNet as the Torsades de Pointes (TdP) risk assessment biomarker, obtained from in silico simulation. However, using a single in silico feature, such as qNet, cannot reflect whole characteristics related to TdP in the entire action potential (AP) shape. Thus, this study proposed a deep convolutional neural network (CNN) model using differential action potential shapes to classify three proarrhythmic risk levels: high, intermediate, and low, considering both characteristics related to TdP not only in the depolarization phase but also the repolarization phase of AP shape. We performed an in silico simulation and got AP shapes with drug effects using half-maximal inhibitory concentration and Hill coefficients of 28 drugs released by CiPA groups. Then, we trained the deep CNN model with the differential AP shapes of 12 drugs and tested it with those of 16 drugs. Our model had a better performance for classifying the proarrhythmic risk of drugs than the traditional logistic regression model using qNet. The classification accuracy was 98% for high-risk level drugs, 94% for intermediate-risk level drugs, and 89% for low-risk level drugs.
- Published
- 2022
13. A Study on Writing Characteristics in the Process of Creating Content in Process-based Writing
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Da-Un Jeong
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Multimedia ,Computer science ,Process (engineering) ,Work in process ,Content (Freudian dream analysis) ,computer.software_genre ,computer - Published
- 2020
14. Cytotoxicity of natural killer cells on canine mammary carcinoma cells
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Hyung-Seok Kim, Bang-Hun Hyun, In-Soo Cho, Moonhee Jung, Na-Yeon Gu, Jienny Lee, Da-Un Jeong, Jeong Su Byeon, Eun-Hee Kim, and Jae-Young Song
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Mammary carcinoma ,Canine Mammary Carcinoma ,business.industry ,Cancer research ,Medicine ,Interferon gamma ,business ,Cytotoxicity ,medicine.drug - Published
- 2020
15. Impact of Personal Protective Equipment on Out-of-Hospital Cardiac Arrest Resuscitation in Coronavirus Pandemic
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Guntak Lee, Tae Gun Shin, Jong Eun Park, Da-Un Jeong, Hye-Young Ko, IkJoon Jo, Min-Seob Sim, and Sung Yeon Hwang
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Resuscitation ,medicine.medical_specialty ,Medicine (General) ,medicine.medical_treatment ,cardiac arrest ,Return of spontaneous circulation ,Article ,R5-920 ,medicine ,Humans ,Intubation ,Cardiopulmonary resuscitation ,Pandemics ,powered air-purifying respirator ,personal protective equipment ,Retrospective Studies ,Powered air-purifying respirator ,business.industry ,Retrospective cohort study ,General Medicine ,Odds ratio ,Emergency department ,Coronavirus ,Emergency medicine ,business ,Out-of-Hospital Cardiac Arrest - Abstract
Background and Objectives: This retrospective study evaluated the clinical impact of enhanced personal protective equipment (PPE) on the clinical outcomes in patients with out-of-hospital cardiac arrest. Moreover, by focusing on the use of a powered air-purifying respirator (PAPR), we investigated the medical personnel’s perceptions of wearing PAPR during cardiopulmonary resuscitation. Materials and Methods: According to the arrival time at the emergency department, the patients were categorized into a conventional PPE group (1 August 2019 to 20 January 2020) and an enhanced PPE group (21 January 2020, to 31 August 2020). The primary outcomes of this analysis were the return of spontaneous circulation (ROSC) rate. Additionally, subjective perception of the medical staff regarding the effect of wearing enhanced PPE during cardiopulmonary resuscitation (CPR) was evaluated by conducting a survey. Results: This study included 130 out-of-hospital cardiac arrest (OHCA) patients, with 73 and 57 patients in the conventional and enhanced PPE groups, respectively. The median time intervals to first intubation and to report the first arterial blood gas analysis results were longer in the enhanced PPE group than in the conventional PPE group (3 min vs. 2 min; p = 0.020 and 8 min vs. 3 min; p < 0.001, respectively). However, there were no significant differences in the ROSC rate (odds ratio (OR) = 0.79, 95% confidence interval (CI): 0.38–1.67; p = 0.542) and 1 month survival (OR 0.38, 95% CI: 0.07–2.10; p = 0.266) between the two groups. In total, 67 emergent department (ED) professionals responded to the questionnaire. Although a significant number of respondents experienced inconveniences with PAPR use, they agreed that PAPR was necessary during the CPR procedure for protection and reduction of infection transmission. Conclusion: The use of enhanced PPE, including PAPR, affected the performance of CPR to some extent but did not alter patient outcomes. PAPR use during the resuscitation of OHCA patients might positively impact the psychological stability of the medical staff.
- Published
- 2021
- Full Text
- View/download PDF
16. Discovery of a NADPH oxidase inhibitor, (E)-3-cyclohexyl-5-(4-((2-hydroxyethyl)(methyl)amino)benzylidene)-1-methyl-2-thioxoimidazolidin-4-oneone, as a novel therapeutic for Parkinson's disease
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Seunghwan Shim, Da Un Jeong, Hyemi Kim, Chae Yun Kim, Hyejun Park, Yinglan Jin, Kyung Min Kim, Hwa Jeong Lee, Dong Hwan Kim, Yun Soo Bae, and Yongseok Choi
- Subjects
Inflammation ,Lipopolysaccharides ,Pharmacology ,Dopaminergic Neurons ,Organic Chemistry ,NADPH Oxidases ,Parkinson Disease ,General Medicine ,Imidazolidines ,Mice, Inbred C57BL ,Antiparkinson Agents ,Mice ,Disease Models, Animal ,Drug Discovery ,Animals ,Cytokines ,Microglia ,Enzyme Inhibitors - Abstract
Several lines of evidence indicated that generation of NADPH oxidase (Nox)-mediated reactive oxygen species are associated with neuronal inflammation, leading to Parkinson's disease (PD). Novel benzylidene-1-methyl-2-thioxoimidazolidin-one derivatives as Nox inhibitors were designed and synthesized in order to increase blood-brain barrier (BBB) permeability to target Nox in brain cells. In lucigenin chemiluminescence assay, eight compounds showed excellent inhibition activity against NADPH oxidases and parallel artificial membrane permeability assay (PAMPA) identified compound 11 with high passive permeability. To validate the effect of compound 11 on neuronal inflammation, we tested the regulatory activity of compound 11 in lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines in BV-2 microglial cells and LPS-mediated microglial migration. Treatment of BV2 cells with compound 11 resulted in suppressed production of pro-inflammatory cytokines and migration activity of BV2 cells in response to LPS. To evaluate the therapeutic efficacy of compound 11 in PD animal model, compound 11 was applied to MPTP-induced PD mouse model. Oral administration of compound 11 (30 mg/kg/daily, 4 weeks) into the mice resulted in suppression of dopaminergic neuronal death in substantia nigra (SN) and in striatum as well as inhibition of microglial migration into SN. These results implicate compound 11 as a novel therapeutic agent for the treatment of PD.
- Published
- 2022
17. Assessment of Drug Proarrhythmicity Using Artificial Neural Networks With
- Author
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Yedam, Yoo, Aroli, Marcellinus, Da Un, Jeong, Ki-Suk, Kim, and Ki Moo, Lim
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toxicology classification ,Physiology ,in silico ,comprehensive in vitro proarrhythmic assay (CiPA) ,artificial neural network (ANN) ,Brief Research Report ,proarrhythmicity - Abstract
As part of the Comprehensive in vitro Proarrhythmia Assay initiative, methodologies for predicting the occurrence of drug-induced torsade de pointes via computer simulations have been developed and verified recently. However, their predictive performance still requires improvement. Herein, we propose an artificial neural networks (ANN) model that uses nine multiple input features, considering the action potential morphology, calcium transient morphology, and charge features to further improve the performance of drug toxicity evaluation. The voltage clamp experimental data for 28 drugs were augmented to 2,000 data entries using an uncertainty quantification technique. By applying these data to the modified O’Hara Rudy in silico model, nine features (dVm/dtmax, APresting, APD90, APD50, Caresting, CaD90, CaD50, qNet, and qInward) were calculated. These nine features were used as inputs to an ANN model to classify drug toxicity into high-risk, intermediate-risk, and low-risk groups. The model was trained with data from 12 drugs and tested using the data of the remaining 16 drugs. The proposed ANN model demonstrated an AUC of 0.92 in the high-risk group, 0.83 in the intermediate-risk group, and 0.98 in the low-risk group. This was higher than the classification performance of the method proposed in previous studies.
- Published
- 2021
18. Suppression of Osteoarthritis progression by post-natal Induction of Nkx3.2
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Byung Hyune Choi, Hye-Kyoung Oh, Hye Jeong Choi, Jeong Ah Kim, Byoung Ju Kim, Minsun Park, Seungwon Choi, Dae-Won Kim, Byoung-Hyun Min, Jin-Hong Kim, Da-Un Jeong, Yongsik Cho, Je Kyung Seong, and Jimin Lee
- Subjects
Oncology ,medicine.medical_specialty ,Biophysics ,Osteoarthritis ,urologic and male genital diseases ,Biochemistry ,Chondrocyte ,Muscle hypertrophy ,Pathogenesis ,Joint disease ,Mice ,Internal medicine ,medicine ,Animals ,Molecular Biology ,Homeodomain Proteins ,urogenital system ,business.industry ,Cartilage ,Cell Biology ,medicine.disease ,Disease Models, Animal ,medicine.anatomical_structure ,Drug development ,business ,Blood vessel ,Transcription Factors - Abstract
Osteoarthritis (OA) is an incurable joint disease affecting 240 million elderly population, and major unmet medical needs exist for better therapeutic options for OA. During skeletal development, Nkx3.2 has been shown to promote chondrocyte differentiation and survival, but to suppress cartilage hypertrophy and blood vessel invasion. Here we show that Nkx3.2 plays a key role in osteoarthritis (OA) pathogenesis. Marked reduction of Nkx3.2 expression was observed in three different murine OA models. Consistent with these findings, analyses of surgery-induced and age-driven OA models revealed that cartilage-specific post-natal induction of Nkx3.2 can suppress OA progression in mice. These results suggest that Nkx3.2 may serve as a promising target for OA drug development.
- Published
- 2021
19. Isolation and characterization of deer-derived mesenchymal stem cells
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Jae-Young Song, Chan-Lan Kim, Na-Yeon Gu, Da-Un Jeong, In-Soo Cho, Bang-Hun Hyun, Jienny Lee, and Jeong Su Byeon
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medicine.anatomical_structure ,Mesenchymal stem cell ,medicine ,Adipose tissue ,Bone marrow ,Biology ,Isolation (microbiology) ,Cell biology - Published
- 2019
20. Characteristics of mesenchymal stem cells derived from different tissues of goat
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Bang-Hun Hyun, In-Soo Cho, Jae-Young Song, Jeong Su Byeon, Da-Un Jeong, Jienny Lee, and Na-Yeon Gu
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Pathology ,medicine.medical_specialty ,medicine.anatomical_structure ,Mesenchymal stem cell ,medicine ,Adipose tissue ,Bone marrow ,Biology - Published
- 2019
21. Relationship between Servant Leadership, Independent·Critic Followership and Job Satisfaction in China : Focused on Moderating Effects of Role Conflict
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Da-Un Jeong and Myeong-Cheol Choi
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Followership ,Servant leadership ,Job satisfaction ,China ,Psychology ,Social psychology ,Role conflict - Published
- 2019
22. The Mediation Effect of Trust and Communication on Relationship between Organizational Culture and Innovative Behavior: Focused on Manufacturing Business
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Da-Un Jeong and Byung-June Chun
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Knowledge management ,business.industry ,Mediation ,Organizational culture ,Psychology ,business - Published
- 2019
23. The Effect of Regulatory Focus on Job Scope: Effects of Affective Commitment and Continuance Commitment
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Da-Un Jeong and Byung-June Chun
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Scope (project management) ,Regulatory focus theory ,Organizational commitment ,Psychology ,Social psychology - Published
- 2019
24. Differentiation potential of canine mesenchymal stem cells on hydrogel scaffold-based three-dimensional environment
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Jeong Su Byeon, Mi Jeong Park, In-Soo Cho, Jienny Lee, Da-Un Jeong, Sang-Ho Cha, and Na-Yeon Gu
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Extracellular matrix ,Chemistry ,Self-healing hydrogels ,Mesenchymal stem cell ,Chondrogenesis ,Hydrogel scaffold ,Cell biology - Published
- 2018
25. Tumorsphere formation and cancer stem cell characterization of REM134 canine mammary carcinoma cells
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Da-Un Jeong, Jeong Su Byeon, In-Soo Cho, Jienny Lee, Sang-Ho Cha, and Na-Yeon Gu
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Canine Mammary Carcinoma ,Cancer stem cell ,Cancer research ,medicine ,Animal Mammary Neoplasms ,Biology ,Carcinogenesis ,medicine.disease_cause - Published
- 2018
26. Transcriptomic analysis and competing endogenous RNA network in the human endometrium between proliferative and mid‑secretory phases
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Da-Un Jeong, Yujin Kang, Tae-Hyun Kim, Dong Chul Lee, Seok-Rae Park, Seong-Lan Yu, Jaeku Kang, and Young-Hyun Han
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competing endogenous RNA network ,Cancer Research ,Messenger RNA ,Oncogene ,endometrial receptivity ,Competing endogenous RNA ,mid-secretory endometrium ,RNA sequencing ,Articles ,General Medicine ,Biology ,Cell biology ,Transcriptome ,Immunology and Microbiology (miscellaneous) ,proliferative endometrium ,Gene expression ,microRNA ,KEGG ,Gene - Abstract
Successful embryo implantation is the first step for establishing natural pregnancy and is dependent on the crosstalk between the embryo and a receptive endometrium. However, the molecular signaling events for successful embryo implantation are not entirely understood. To identify differentially expressed transcripts [long-noncoding RNAs (lncRNAs), microRNAs (miRNAs) and mRNAs] and competing endogenous RNA (ceRNA) networks associated with endometrial receptivity, the current study analyzed gene expression profiles between proliferative and mid-secretory endometria in fertile women. A total of 247 lncRNAs, 67 miRNAs and 2,154 mRNAs were identified as differentially expressed between proliferative and mid-secretory endometria. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that these differentially expressed genes were significantly enriched for 'cell adhesion molecules.' Additionally, 98 common mRNAs were significantly involved in tryptophan metabolism, metabolic pathways and FoxO signaling. From the differentially expressed lncRNA/miRNA/mRNA ceRNA network, hub RNAs that formed three axes were identified: The DLX6-AS1/miR-141 or miR-200a/OLFM1 axis, the WDFY3-AS2/miR-135a or miR-183/STC1 axis, and the LINC00240/miR-182/NDRG1 axis. These may serve important roles in the regulation of endometrial receptivity. The hub network of the current study may be developed as a candidate marker for endometrial receptivity.
- Published
- 2021
27. Assessment of Drug Proarrhythmicity Using Artificial Neural Network with in Silico Deterministic Model Outputs
- Author
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Yedam Yoo, Aroli Marcellinus, Da Un Jeong, Ki-Suk Kim, and Ki Moo Lim
- Abstract
Methodologies for predicting the occurrence of torsade de pointes by drugs via computer simulations have been developed and verified recently, as part of the Comprehensive in vitro Proarrhythmia Assay initiative. However, the predictive performance still requires improvement. Herein, we propose a deep learning algorithm based on artificial neural networks that receives nine multiple features and considers the action potential morphology, calcium concentration morphology, and charge characteristics to further improve drug toxicity evaluation performance. The voltage clamp experimental data for 28 drugs were augmented to 2,000 data entries using an uncertainty quantification technique. By applying these data to the modified Ohara Rudy in silico model, nine features (dVm/dtmax, APresting, APD90, APD50, Caresting, CaD90, CaD50, qNet, and qInward) were predicted. These nine features were used as inputs to an artificial neural network (ANN) model to classify drug toxicity into high-risk, intermediate, and low-risk groups. The model was trained with data of 12 drugs and tested with the data of the remaining 16 drugs. The proposed ANN model demonstrated an AUC of 0.94 in the high-risk group, 0.73 in the intermediate group, and 0.91 in the low-risk group. This is higher than the classification performance of the method proposed in previous studies.
- Published
- 2021
28. Canine Natural Killer Cell-Derived Exosomes Exhibit Antitumor Activity in a Mouse Model of Canine Mammary Tumor
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Jeong Su Byeon, Yoon-Hee Lee, Bang-Hun Hyun, So Yeon Jeong, Se-A Lee, Na-Yeon Gu, In-Ohk Ouh, Jienny Lee, and Da-Un Jeong
- Subjects
Article Subject ,Primary Cell Culture ,Mice, Nude ,Antineoplastic Agents ,Apoptosis ,Breast Neoplasms ,Mammary Neoplasms, Animal ,Tumor initiation ,Biology ,Exosomes ,medicine.disease_cause ,General Biochemistry, Genetics and Molecular Biology ,Natural killer cell ,Malignant transformation ,Mice ,Dogs ,Cell Movement ,Cancer stem cell ,Cell Line, Tumor ,Biomarkers, Tumor ,medicine ,Animals ,Cell Proliferation ,Canine Mammary Carcinoma ,Mice, Inbred BALB C ,Mammary tumor ,General Immunology and Microbiology ,General Medicine ,Xenograft Model Antitumor Assays ,Killer Cells, Natural ,Disease Models, Animal ,medicine.anatomical_structure ,Granzyme ,Cancer research ,biology.protein ,Medicine ,Female ,Carcinogenesis ,Research Article - Abstract
Natural killer (NK) cells are key immune cells engaged in fighting infection and malignant transformation. In this study, we found that canine NK cell-derived exosomes (NK-exosomes) separated from activated cytotoxic NK cell supernatants express specific markers including CD63, CD81, Alix, HSP70, TSG101, Perforin 1, and Granzyme B. We examined the antitumor effects of NK-exosomes in an experimental murine mammary tumor model using REM134 canine mammary carcinoma cell line. We observed changes in tumor size, tumor initiation, progression, and recurrence-related markers in the control, tumor group, and NK-exosome-treated tumor group. We found that the tumor size in the NK-exosome-treated tumor group decreased compared with that of the tumor group in the REM134-driven tumorigenic mouse model. We observed significant changes including the expression of tumorigenesis-related markers, such as B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi-1), vascular endothelial growth factor (VEGF), matrix metallopeptidase-3 (MMP-3), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), multidrug resistance protein (MDR), tumor suppressor protein p53 (p53), proliferating cell nuclear antigen (PCNA), and the apoptotic markers, B cell lymphoma-2 associated X (Bax) and B cell lymphoma-extra large (Bcl-xL) belonging to the Bcl-2 family, in the tumor group compared with those in the control group. The expression of CD133, a potent cancer stem cell marker, was significantly higher than that of the control. By contrast, the NK-exosome-treated tumor group exhibited a significant reduction in Bmi-1, MMP-3, IL-1β, IL-6, TNF-α, Bax, Bcl-xL, and PCNA expression compared with that in the tumor group. Furthermore, the expression of CD133, which mediates tumorigenesis, was significantly decreased in the NK-exosome-treated tumor group compared with that in the tumor group. These findings indicate that canine NK-exosomes represent a promising therapeutic tool against canine solid tumors, including mammary carcinoma.
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- 2021
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29. Optimal Length of Heart Rate Variability Data and Forecasting Time for Ventricular Fibrillation Prediction Using Machine Learning
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Da Un Jeong, Ki Moo Lim, Han-Jeong Hwang, and Getu Tadele Taye
- Subjects
medicine.medical_specialty ,020205 medical informatics ,Article Subject ,Computer applications to medicine. Medical informatics ,R858-859.7 ,02 engineering and technology ,030204 cardiovascular system & hematology ,Sudden death ,General Biochemistry, Genetics and Molecular Biology ,Artificial neural network classifier ,World health ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Heart rate variability ,General Immunology and Microbiology ,business.industry ,Applied Mathematics ,General Medicine ,medicine.disease ,Modeling and Simulation ,Ventricular fibrillation ,Cardiology ,Biomarker (medicine) ,business - Abstract
Ventricular fibrillation (VF) is a cardiovascular disease that is one of the major causes of mortality worldwide, according to the World Health Organization. Heart rate variability (HRV) is a biomarker that is used for detecting and predicting life-threatening arrhythmias. Predicting the occurrence of VF in advance is important for saving patients from sudden death. We extracted features from seven HRV data lengths to predict the onset of VF before nine different forecast times and observed the prediction accuracies. By using only five features, an artificial neural network classifier was trained and validated based on 10-fold cross-validation. Maximum prediction accuracies of 88.18% and 88.64% were observed at HRV data lengths of 10 and 20 s, respectively, at a forecast time of 0 s. The worst prediction accuracy was recorded at an HRV data length of 70 s and a forecast time of 80 s. Our results showed that features extracted from HRV signals near the VF onset could yield relatively high VF prediction accuracies.
- Published
- 2021
- Full Text
- View/download PDF
30. Prediction of Cardiac Mechanical Performance From Electrical Features During Ventricular Tachyarrhythmia Simulation Using Machine Learning Algorithms
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Da Un Jeong and Ki Moo Lim
- Subjects
Stochastic modelling ,Computer science ,Physiology ,Quantitative Biology::Tissues and Organs ,0206 medical engineering ,Physics::Medical Physics ,computational study ,02 engineering and technology ,030204 cardiovascular system & hematology ,Machine learning ,computer.software_genre ,lcsh:Physiology ,Contractility ,03 medical and health sciences ,0302 clinical medicine ,Polynomial kernel ,Physiology (medical) ,Optical mapping ,support vector regression ,Original Research ,Artificial neural network ,lcsh:QP1-981 ,business.industry ,Stroke volume ,ventricular tachyarrhythmia ,020601 biomedical engineering ,mechanical performance ,Support vector machine ,Kernel (statistics) ,electrical instability ,Artificial intelligence ,business ,Algorithm ,computer ,artificial neural network - Abstract
In ventricular tachyarrhythmia, electrical instability features including action potential duration, dominant frequency, phase singularity, and filaments are associated with mechanical contractility. However, there are insufficient studies on estimated mechanical contractility based on electrical features during ventricular tachyarrhythmia using a stochastic model. In this study, we predicted cardiac mechanical performance from features of electrical instability during ventricular tachyarrhythmia simulation using machine learning algorithms, including support vector regression (SVR) and artificial neural network (ANN) models. We performed an electromechanical tachyarrhythmia simulation and extracted 12 electrical instability features and two mechanical properties, including stroke volume and the amplitude of myocardial tension (ampTens). We compared predictive performance according to kernel types of the SVR model and the number of hidden layers of the ANN model. In the SVR model, the prediction accuracies of stroke volume and ampTens were the highest when using the polynomial kernel and linear kernel, respectively. The predictive performance of the ANN model was better than that of the SVR model. The prediction accuracies were the highest when the ANN model consisted of three hidden layers. Accordingly, we propose the ANN model with three hidden layers as an optimal model for predicting cardiac mechanical contractility in ventricular tachyarrhythmia. The results of this study are expected to be used to indirectly estimate the hemodynamic response from the electrical cardiac map measured by the optical mapping system during cardiac surgery, as well as cardiac contractility under normal sinus rhythm conditions.
- Published
- 2020
31. Bovine tongue epithelium-derived cells: A new source of bovine mesenchymal stem cells
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Jeong Su Byeon, Se-A Lee, Bang-Hun Hyun, Na-Yeon Gu, Yoon-Hee Lee, Jae-Young Song, Siu Lee, Jienny Lee, Da-Un Jeong, In-Soo Cho, and In-Ohk Ouh
- Subjects
Primary Cell Culture ,Biophysics ,Biochemistry ,Regenerative medicine ,Chondrocyte ,Tongue tissue ,Tongue ,SOX2 ,medicine ,Animals ,CD90 ,Molecular Biology ,Cells, Cultured ,Research Articles ,Cell Proliferation ,biology ,Cluster of differentiation ,Stem Cells ,CD44 ,Mesenchymal stem cell ,Mouth Mucosa ,Cell Differentiation ,Epithelial Cells ,Mesenchymal Stem Cells ,Bovine ,Cell Biology ,Cell biology ,medicine.anatomical_structure ,Osteocyte ,biology.protein ,Cattle ,Biotechnology - Abstract
Mesenchymal stem cells (MSCs) possess the ability to differentiate into multiple cell lineages, and thus, confer great potential for use in regenerative medicine and biotechnology. In the present study, we attempted to isolate and characterize bovine tongue tissue epithelium-derived MSCs (boT-MSCs) and investigate the culture conditions required for long-term culturing of boT-MSCs. boT-MSCs were successfully isolated by the collagenase digestion method and their proliferative capacity was maintained for up to 20 or more passages. We observed a significant increase in the proliferation of boT-MSCs during the 20 consecutive passages under low-glucose Dulbecco’s modified Eagle’s medium culture condition among the three culture conditions. These boT-MSCs presented pluripotency markers (octamer-binding transcription factor 3/4 (Oct3/4) and sex determining region Y-box2 (Sox2)) and cell surface markers, which included CD13, CD29, CD44, CD73, CD90, CD105, CD166, and major histocompatibility complex (MHC) class I (MHC-I) but not CD11b, CD14, CD31, CD34, CD45, CD80, CD86, CD106, CD117, and MHC-II at third passage. Moreover, these boT-MSCs could differentiate into mesodermal (adipocyte, osteocyte, and chondrocyte) cell lineages. Thus, the present study suggests that the tongue of bovines could be used as a source of bovine MSCs.
- Published
- 2020
32. Relationship Between Electrical Instability and Pumping Performance During Ventricular Tachyarrhythmia: Computational Study
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Ki Moo Lim and Da Un Jeong
- Subjects
Physiology ,Stochastic modelling ,0206 medical engineering ,dominant frequency ,computational study ,02 engineering and technology ,030204 cardiovascular system & hematology ,Electrical phenomena ,lcsh:Physiology ,action potential duration ,Contractility ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,stochastic model ,Original Research ,Physics ,lcsh:QP1-981 ,Regression analysis ,ventricular tachyarrhythmia ,Reentry ,Stroke volume ,Mechanics ,020601 biomedical engineering ,Amplitude ,phase singularity ,filament ,Multicollinearity ,cardiovascular system - Abstract
There are representative electrical parameters for understanding the mechanism of reentrant waves in studies on tachyarrhythmia, namely the action potential duration (APD), dominant frequency, phase singularity, and filament. However, there are no studies that have directly identified the correlation between these electrophysiological parameters and cardiac contractility. Therefore, we have identified individual and integrative correlations between these electrical phenomena and contractility during tachyarrhythmia by deriving regression equations and also investigated the electrophysiological parameters affecting cardiac contractility during tachyarrhythmia. We simulated ventricular tachyarrhythmia with 48 types of electrical patterns by applying four reentry generation methods and changing the electrical conductivity of the potassium channel, which has the greatest effect on ventricular tissue. The mechanical responses reflecting electrical complexity were obtained through deterministic simulations of excitation–contraction coupling. We used the stroke volume and amplitude of myocardial tension (ampTens) as the variables representing contractility. We derived stochastic models through single- and multivariable regression analyses to identify the electrical parameters affecting contractility during tachyarrhythmia. In single-variable regression analysis, the APD, dominant frequency, and filament, excluding phase singularity, have statistically significant correlations with the stroke volume and ampTens. Among them, the APD has the maximum influence on these two mechanical parameters (standard beta coefficient: 0.859 for stroke volume, 0.930 for ampTens). The stochastic model using all four electrical parameters fails to accurately predict contractility owing to the multicollinearity between the APD and dominant frequency. We have rederived the multi-variable stochastic model using three electrical parameters without the APD. The filament has the greatest effect on the stroke volume stochastically (standard beta coefficient: 0.853 and 0.752). The dominant frequency has the greatest effect on ampTens statistically (standard beta coefficient: −0.813). We conclude that among the electrical parameters, the APD has the highest individual influence on mechanical contraction, and the filament has the highest integrative influence in both statistical terms.
- Published
- 2020
33. Proarrhythmogenic Effect of the L532P and N588K
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Aulia Khamas, Heikhmakhtiar, Abebe Tekle, Abrha, Da Un, Jeong, and Ki Moo, Lim
- Subjects
N588K Mutation ,ERG1 Potassium Channel ,Models, Cardiovascular ,Biomedical Engineering ,L532P Mutation ,Action Potentials ,Arrhythmias, Cardiac ,Heart ,KCNH2 Gene Mutation ,Polymorphism, Single Nucleotide ,Imaging, Three-Dimensional ,cardiovascular system ,Humans ,Original Article ,Three-dimensional Heart Modeling - Abstract
Background Atrial arrhythmia is a cardiac disorder caused by abnormal electrical signaling and transmission, which can result in atrial fibrillation and eventual death. Genetic defects in ion channels can cause myocardial repolarization disorders. Arrhythmia-associated gene mutations, including KCNH2 gene mutations, which are one of the most common genetic disorders, have been reported. This mutation causes abnormal QT intervals by a gain of function in the rapid delayed rectifier potassium channel (IKr). In this study, we demonstrated that mutations in the KCNH2 gene cause atrial arrhythmia. Methods The N588K and L532P mutations were induced in the Courtemanche-Ramirez-Nattel (CRN) cell model, which was subjected to two-dimensional and three-dimensional simulations to compare the electrical conduction patterns of the wild-type and mutant-type genes. Results In contrast to the early self-termination of the wild-type conduction waveforms, the conduction waveform of the mutant-type retained the reentrant wave (N588K) and caused a spiral break-up, resulting in irregular wave generation (L532P). Conclusion The present study confirmed that the KCNH2 gene mutation increases the vulnerability of the atrial tissue for arrhythmia., Graphical Abstract
- Published
- 2020
34. Proarrhythmogenic Effect of the L532P and N588K KCNH2 Mutations in the Human Heart Using a 3D Electrophysiological Model
- Author
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Da Un Jeong, Ki Moo Lim, Abebe Tekle Abrha, and Aulia Khamas Heikhmakhtiar
- Subjects
medicine.medical_specialty ,Mutation ,business.industry ,Human heart ,Atrial fibrillation ,General Medicine ,Gene mutation ,medicine.disease ,medicine.disease_cause ,Potassium channel ,03 medical and health sciences ,Electrophysiology ,0302 clinical medicine ,Internal medicine ,cardiovascular system ,medicine ,Cardiology ,030212 general & internal medicine ,business ,Gene ,Ion channel - Abstract
Background Atrial arrhythmia is a cardiac disorder caused by abnormal electrical signaling and transmission, which can result in atrial fibrillation and eventual death. Genetic defects in ion channels can cause myocardial repolarization disorders. Arrhythmia-associated gene mutations, including KCNH2 gene mutations, which are one of the most common genetic disorders, have been reported. This mutation causes abnormal QT intervals by a gain of function in the rapid delayed rectifier potassium channel (IKr). In this study, we demonstrated that mutations in the KCNH2 gene cause atrial arrhythmia. Methods The N588K and L532P mutations were induced in the Courtemanche-Ramirez-Nattel (CRN) cell model, which was subjected to two-dimensional and three-dimensional simulations to compare the electrical conduction patterns of the wild-type and mutant-type genes. Results In contrast to the early self-termination of the wild-type conduction waveforms, the conduction waveform of the mutant-type retained the reentrant wave (N588K) and caused a spiral break-up, resulting in irregular wave generation (L532P). Conclusion The present study confirmed that the KCNH2 gene mutation increases the vulnerability of the atrial tissue for arrhythmia.
- Published
- 2020
35. Computational Study to Identify the Effects of the KCNJ2 E299V Mutation in Cardiac Pumping Capacity
- Author
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Da Un Jeong, Ki Moo Lim, and Jiyeong Lee
- Subjects
medicine.medical_specialty ,Article Subject ,Heart Ventricles ,Computer applications to medicine. Medical informatics ,Finite Element Analysis ,R858-859.7 ,030204 cardiovascular system & hematology ,Gene mutation ,QT interval ,General Biochemistry, Genetics and Molecular Biology ,Contractility ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Sinus rhythm ,Computer Simulation ,Potassium Channels, Inwardly Rectifying ,030304 developmental biology ,Fibrillation ,0303 health sciences ,General Immunology and Microbiology ,Chemistry ,Applied Mathematics ,Models, Cardiovascular ,Computational Biology ,Short QT syndrome ,Arrhythmias, Cardiac ,General Medicine ,medicine.disease ,Myocardial Contraction ,Biomechanical Phenomena ,Electrophysiological Phenomena ,Modeling and Simulation ,Mutation (genetic algorithm) ,Ventricular fibrillation ,Mutation ,Cardiology ,medicine.symptom ,Research Article - Abstract
The KCNJ2 gene mutations induce short QT syndrome (SQT3) by directly increasing the IK1 current. There have been many studies on the electrophysiological effects of mutations such as the KCNJ2 D172N that cause the SQT3. However, the KCNJ2 E299V mutation is distinguished from other representative gene mutations that can induce the short QT syndrome (SQT3) in that it increased IK1 current by impairing the inward rectification of K+ channels. The studies of the electromechanical effects on myocardial cells and mechanisms of E299V mutations are limited. Therefore, we investigated the electrophysiological changes and the concomitant mechanical responses according to the expression levels of the KCNJ2 E299V mutation during sinus rhythm and ventricular fibrillation. We performed excitation-contraction coupling simulations using a human ventricular model with both electrophysiological and mechanical properties. In order to observe the electromechanical changes due to the expression of KCNJ2 E299V mutation, the simulations were performed under normal condition (WT), heterogeneous mutation condition (WT/E299V), and pure mutation condition (E299V). First, a single-cell simulation was performed in three types of ventricular cells (endocardial cell, midmyocardial cell, and epicardial cell) to confirm the electrophysiological changes and arrhythmogenesis caused by the KCNJ2 E299V mutation. In three-dimensional sinus rhythm simulations, we compared electrical changes and the corresponding changes in mechanical performance caused by the expression level of E299V mutation. Then, we observed the electromechanical properties of the E299V mutation during ventricular fibrillation using the three-dimensional reentry simulation. The KCNJ2 E299V mutation accelerated the opening of the IK1 channel and increased IK1 current, resulting in a decrease in action potential duration. Accordingly, the QT interval was reduced by 48% and 60% compared to the WT condition, for the WT/E299V and E299V conditions, respectively. During sustained reentry, the wavelength was reduced due to the KCNJ2 E299V mutation. Furthermore, there was almost no ventricular contraction in both WT/E299V and E299V conditions. We concluded that in both sinus rhythm and fibrillation, the KCNJ2 E299V mutation results in very low contractility regardless of the expression level of mutation and increases the risk of cardiac arrest and cardiac death.
- Published
- 2019
36. Effects of Abalone Farming Cage Removal on the Benthic Foraminiferal Assemblages
- Author
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Han Jun Woo, Da Un Jeong, Yang Ho Choi, Yeon Gyu Lee, and Jae Ung Choi
- Subjects
010504 meteorology & atmospheric sciences ,Ecology ,Abalone ,Water circulation ,business.industry ,Sediment ,010501 environmental sciences ,01 natural sciences ,Oceanography ,Aquaculture ,Benthic zone ,Agriculture ,Environmental science ,Cage ,business ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology - Abstract
Choi, J.U.; Lee, Y.G.; Jeong, D.U.; Choi, Y.H., and Woo, H.J., 2018. Effects of Abalone Farming Cage Removal on the Benthic Foraminiferal Assemblages. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 321–325. Coconut Creek (Florida), ISSN 0749-0208. To improve the aquaculture environment of an abalone farm near the Bogil Island, relocation was executed via the partial relocation of cages. The surface sediments were collected from nine stations to analyze the grain size, geochemical characteristics, and benthic foraminiferal assemblages in May (before) and August (after) 2015. Although no distinct environmental changes in the cage area were observed, the relocation area had an increased sand content caused by water circulation. In addition, despite the increase in the sediment temperature, the ignition loss decreased while the dissolved oxygen in the se...
- Published
- 2018
37. Immunomodulatory effects of stem cell application in equine musculoskeletal disorders
- Author
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In-Soo Cho, Jeong Su Byeon, Jienny Lee, Da-Un Jeong, Mi Jeong Park, Na-Yeon Gu, and Sang-Ho Cha
- Subjects
0301 basic medicine ,Cell therapy ,03 medical and health sciences ,030104 developmental biology ,business.industry ,Mesenchymal stem cell ,Cancer research ,Medicine ,Tendonitis ,Bone fracture ,Stem cell ,business ,medicine.disease - Published
- 2018
38. Effects of cryopreservation on equine adipose tissue-derived mesenchymal stem cell plasticity
- Author
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In-Soo Cho, Jeong Su Byeon, Da-Un Jeong, Jienny Lee, Na-Yeon Gu, Mi Jeong Park, and Sang-Ho Cha
- Subjects
0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Mesenchymal stem cell ,Adipose tissue ,Cellular senescence ,Plasticity ,Biology ,Cryopreservation ,Cell biology - Published
- 2018
39. Proliferating effects of vegetable resources in equine mesenchymal stem cells
- Author
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Jeong Su Byeon, Mi Jeong Park, Da-Un Jeong, In-Soo Cho, Jienny Lee, Sang-Ho Cha, and Na-Yeon Gu
- Subjects
0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Cell growth ,Mesenchymal stem cell ,Biology ,Cell biology - Published
- 2017
40. Establishment of bovine tongue epithelium-derived mesenchymal stem cells
- Author
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Da-Un Jeong, In-Soo Cho, Mi Jeong Park, Na-Yeon Gu, Sang-Ho Cha, Jeong Su Byeon, and Jienny Lee
- Subjects
0301 basic medicine ,03 medical and health sciences ,030104 developmental biology ,Mesenchymal stem cell ,Tongue epithelium ,Biology ,Cell biology - Published
- 2017
41. Effects of Mussel farming on hypoxia formation and benthic foraminiferal assemblages in Gamak Bay during spring season
- Author
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Ha Neul Park, Chan Mee Park, Lee Yeon Gyu, Da Un Jeong, Jae Ung Choi, and Lee Jung Sick
- Subjects
Oceanography ,Benthic zone ,Agriculture ,business.industry ,Spring season ,Environmental science ,Hypoxia (environmental) ,Mussel ,business ,Bay - Published
- 2017
42. RhoA knockdown by cationic amphiphilic copolymer/siRhoA polyplexes enhances axonal regeneration in rat spinal cord injury model
- Author
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Ken Webb, Christian Macks, Mark S. Kindy, Jeoung Soo Lee, So-Jung Gwak, Da Un Jeong, and Michael Lynn
- Subjects
Male ,rho GTP-Binding Proteins ,0301 basic medicine ,RHOA ,Materials science ,Polymers ,Biophysics ,Bioengineering ,Article ,Rats, Sprague-Dawley ,Biomaterials ,Surface-Active Agents ,03 medical and health sciences ,0302 clinical medicine ,Cations ,medicine ,Animals ,Gene silencing ,Gene Silencing ,RNA, Small Interfering ,Spinal cord injury ,Spinal Cord Injuries ,Gene knockdown ,biology ,Regeneration (biology) ,Genetic Therapy ,medicine.disease ,Spinal cord ,Molecular biology ,Axons ,Nerve Regeneration ,Rats ,Astrogliosis ,Cell biology ,Treatment Outcome ,030104 developmental biology ,medicine.anatomical_structure ,Mechanics of Materials ,Ceramics and Composites ,biology.protein ,Signal transduction ,030217 neurology & neurosurgery - Abstract
Spinal cord injury (SCI) results in permanent loss of motor and sensory function due to developmentally-related and injured-induced changes in the extrinsic microenvironment and intrinsic neuronal biochemistry that limit plasticity and axonal regeneration. Our long term goal is to develop cationic, amphiphilic copolymers (poly (lactide-co-glycolide)-g-polyethylenimine, PgP) for combinatorial delivery of therapeutic nucleic acids (TNAs) and drugs targeting these different barriers. In this study, we evaluated the ability of PgP to deliver siRNA targeting RhoA, a critical signaling pathway activated by multiple extracellular inhibitors of axonal regeneration. After generation of rat compression SCI model, PgP/siRhoA polyplexes were locally injected into the lesion site. Relative to untreated injury only, PgP/siRhoA polyplexes significantly reduced RhoA mRNA and protein expression for up to 4 weeks post-injury. Histological analysis at 4 weeks post-injury showed that RhoA knockdown was accompanied by reduced apoptosis, cavity size, and astrogliosis and increased axonal regeneration within the lesion site. These studies demonstrate that PgP is an efficient non-viral delivery carrier for therapeutic siRhoA to the injured spinal cord and may be a promising platform for the development of combinatorial TNA/drug therapy.
- Published
- 2017
43. Hydrogel-mediated local delivery of dexamethasone reduces neuroinflammation after traumatic brain injury
- Author
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Ken Webb, Christian Macks, Sooneon Bae, Jeoung Soo Lee, Joseph Whitaker, Da Un Jeong, and Michael Lynn
- Subjects
Male ,Programmed cell death ,Cell Survival ,Traumatic brain injury ,0206 medical engineering ,Anti-Inflammatory Agents ,Biomedical Engineering ,Apoptosis ,Bioengineering ,02 engineering and technology ,Pharmacology ,Dexamethasone ,Polyethylene Glycols ,Rats, Sprague-Dawley ,Biomaterials ,chemistry.chemical_compound ,Drug Delivery Systems ,Brain Injuries, Traumatic ,Hyaluronic acid ,medicine ,Animals ,Hyaluronic Acid ,Neuroinflammation ,Microglia ,Chemistry ,technology, industry, and agriculture ,Hydrogels ,Recovery of Function ,021001 nanoscience & nanotechnology ,medicine.disease ,020601 biomedical engineering ,In vitro ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,Neuroinflammatory Diseases ,0210 nano-technology ,medicine.drug - Abstract
Excessive and prolonged neuroinflammation leads to neuronal cell death and limits functional recovery after traumatic brain injury (TBI). Dexamethasone (DX) is a steroidal anti-inflammatory agent that is known to attenuate early expression of pro-inflammatory cytokines associated with activated microglia/macrophages. In this study, we investigated the effect of dexamethasone-conjugated hyaluronic acid (HA-DXM) incorporated in a hydrolytically degradable, photo-cross-linkable poly (ethylene) glycol-bis-(acryloyloxy acetate) (PEG-bis-AA) hydrogel on the inflammatory response, apoptosis, and functional recovery in a controlled cortical impact (CCI) rat TBI model. In vitro, DX release from PEG-bis-AA/HA-DXM hydrogel was slow in phosphate-buffered saline without enzymes, but significantly increased in the presence of hyauronidase/esterase enzymes. TBI was generated by a CCI device armed with a 3 mm tip (3.5 m s−1, depth: 2 mm) and treated immediately with PEG-bis-AA/HA-DXM hydrogel. PEG-bis-AA/HA hydrogel without DX was used for comparison and untreated TBI group was used as a control. Significant reductions in cavity size, inflammatory response, and apoptosis were observed in animals treated with PEG-bis-AA/HA-DXM compared to those receiving PEG-bis-AA/HA and untreated. Animals receiving the PEG-bis-AA/HA-DXM hydrogel also exhibited higher neuronal cell survival and improved motor functional recovery compared to the other two groups.
- Published
- 2021
44. Effect of abalone farming on seawater movement and benthic foraminiferal assemblage of Zostera marina in the inner bay of Wando, South Korea
- Author
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Jung Sick Lee, Yong Wan Kim, Yeon Gyu Lee, Da Un Jeong, Jung Jun Park, Yang Ho Choi, and Jae Ung Choi
- Subjects
0106 biological sciences ,Geologic Sediments ,010504 meteorology & atmospheric sciences ,Abalone ,Aquaculture ,Foraminifera ,Aquatic Science ,Oceanography ,01 natural sciences ,Benthos ,Republic of Korea ,Animals ,Seawater ,Zostera ,0105 earth and related environmental sciences ,Brackish water ,biology ,Zosteraceae ,010604 marine biology & hydrobiology ,biology.organism_classification ,Pollution ,Fishery ,Bays ,Benthic zone ,Zostera marina ,Bay ,Water Pollutants, Chemical ,Geology ,Environmental Monitoring - Abstract
Tidal current survey as well as geochemical and benthic foraminiferal analyses of sediment cores were conducted in an abalone farm and a Zostera bed to understand the degree to which the abalone farm facilities installed along a channel in a shallow sea affect the benthic environment and ecology. In the abalone farm, Ammonia beccarii-Pseudoparrella naraensis-Elphidium somaense-Rosalina globularis-Trochammina hadai and P. naraensis-E. somaense-A. beccarii-T. hadai assemblages appeared owing to an increase in the total nitrogen content from the biodeposits. The Zostera bed consisted of A. beccarii-P. naraensis-Buccella frigida-T. hadai assemblage owing to the gradual expansion of a brackish shallow-water environment by the rapidly decreasing current speed, and it may have flourished. Moreover, the total sulfur, Zn, Cr, and Cu contents in the sediments decreased remarkably more than those of the pre-abalone farming did, caused by the vigorous activity of Zostera marina physiology.
- Published
- 2016
45. Cartilage-Specific and Cre-Dependent Nkx3.2 Overexpression In Vivo Causes Skeletal Dwarfism by Delaying Cartilage Hypertrophy
- Author
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Da Un Jeong, Dae Won Kim, and Je-Yong Choi
- Subjects
0301 basic medicine ,urogenital system ,Physiology ,Cartilage ,Clinical Biochemistry ,Chondrocyte hypertrophy ,Cell Biology ,Cartilage metabolism ,Anatomy ,Biology ,urologic and male genital diseases ,Chondrogenesis ,Chondrocyte ,Muscle hypertrophy ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,medicine.anatomical_structure ,Intramembranous ossification ,medicine ,Endochondral ossification - Abstract
Nkx3.2, the vertebrate homologue of Drosophila bagpipe, has been implicated as playing a role in chondrogenic differentiation. In brief, Nkx3.2 is initially expressed in chondrocyte precursor cells and later during cartilage maturation, its expression is diminished in hypertrophic chondrocytes. In addition to Nkx3.2 expression analyses, previous studies using ex vivo chick embryo cultures and in vitro cell cultures have suggested that Nkx3.2 can suppress chondrocyte hypertrophy. However, it has never been demonstrated that Nkx3.2 functions in regulating chondrocyte hypertrophy during cartilage development in vivo. Here, we show that cartilage-specific and Cre-dependent Nkx3.2 overexpression in mice results in significant postnatal dwarfism in endochondral skeletons, while intramembranous bones remain unaltered. Further, we observed significant delays in cartilage hypertrophy in conditional transgenic ciTg-Nkx3.2 mice. Together, these findings confirm that Nkx3.2 is capable of controlling hypertrophic maturation of cartilage in vivo, and this regulation plays a significant role in endochondral ossification and longitudinal bone growth. J. Cell. Physiol. 232: 78-90, 2017. © 2016 Wiley Periodicals, Inc.
- Published
- 2016
46. Effects of Isoproterenol and Melatonin Supplementation on In vitro Development of Parthenogenetic Activated Oocytes in Pig
- Author
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Yun-Jin Yun, Da-Un Jeong, and Hee-Sung Park
- Subjects
medicine.medical_specialty ,lcsh:R5-920 ,lcsh:Internal medicine ,isoproterenol ,lcsh:Biotechnology ,melatonin ,Parthenogenesis ,Biology ,porcine ,In vitro ,Melatonin ,Endocrinology ,Internal medicine ,lcsh:TP248.13-248.65 ,in vitro culture ,medicine ,cardiovascular system ,parthenogenesis ,lcsh:Medicine (General) ,lcsh:RC31-1245 ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
In this study, to improve the in vitro development of various cells including cloned embryos, the effects that isoproterenol and melatonin have on in vitro development of porcine parthenogenetic oocytes were investigated. Parthenogenetic activation was induced with electrical stimulation, BSA and 6-DMAP treatment. 10-7 M of melatonin and isoproterenol (10-10, 10-12 and 10-14 M) were supplemented for in vitro maturation (IVM) and in vitro culture (IVC) medium, with different concentrations. When isoproterenol and melatonin were supplemented in IVM medium with different concentrations, there was no significant (p
- Published
- 2016
47. Implication of salt marsh foraminiferal assemblages in Suncheon Bay, South Korea
- Author
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Shin Kim, Da Un Jeong, Yeon Gyu Lee, Jung Sick Lee, and Sora Kang
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,biology ,Ecology ,Sediment ,Species diversity ,Oceanography ,biology.organism_classification ,01 natural sciences ,Foraminifera ,Salinity ,Benthic zone ,Salt marsh ,Bay ,Sea level ,Geology ,0105 earth and related environmental sciences - Abstract
Analyses of the compositions of benthic foraminifera and sediment, observations of tidal level and salinity, and a geographic survey of the tidal salt marsh in Suncheon Bay were conducted to examine the vertical distribution of foraminifera and evaluate their potential use for sea level studies. The salt marsh is composed mainly of fine-grained silty clay sediment and its salinity is below approximately 11 psu. The tidal current flows in the southwest-tonortheast direction with an average velocity of 26.57 cm/s. A total of 33 species of foraminifera (17 agglutinated and 16 calcareoushyaline) belonging to 24 genera was identified. The species diversity (1.1 on average) was relatively low. Dominant species were Ammonia beccarii, Miliammina fusca, Haplophragmoides wilberti, and Jadammina macrescens. Calcareous foraminifera (29.5%) were dominantly represented by the Ammonia beccarii assemblage, which characterized the region between mean tide level and mean low high water (MLHW). Agglutinated species (70.5%) were represented mostly by Miliammina fusca, Miliammina fusca-Haplophragmoides wilberti, and Haplophragmoides wilberti assemblages, which characterized the MLHW–mean high water (MHW), MHW–mean highest high water (MHHW), and MHHW–Approx. highest high water tide levels, respectively. In particular, the Haplophragmoides wilberti assemblage is believed to represent the highest elevation zone of foraminifera in the salt marshes of Suncheon Bay and is considered to be a reliable indicator of sea level as a result of its narrow vertical range.
- Published
- 2016
48. Sugar Contents Analysis of Retort Foods
- Author
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Da-Un Jeong, Jun Im, Young-Kyoung Kim, Cheon-Hoe Kim, Yoonjin Park, Ae-Son Om, and Yoonhwa Jeong
- Subjects
Nutrition and Dietetics ,business.industry ,law ,Medicine ,Food science ,Nutrition facts label ,Sugar ,business ,Retort ,Food Science ,law.invention - Published
- 2015
49. Sediment Geochemistry and Benthic Foraminiferal Response to Fish Farming after Conversion from a Red Laver (Seaweed) Farm
- Author
-
Jeongwon Kang, Yang Ho Choi, Yeon Gyu Lee, Han Jun Woo, and Da Un Jeong
- Subjects
chemistry.chemical_classification ,010504 meteorology & atmospheric sciences ,Ecology ,biology ,010505 oceanography ,Fish farming ,Geochemistry ,Sediment ,Silt ,Sedimentation ,biology.organism_classification ,01 natural sciences ,Foraminifera ,chemistry ,Algae ,Benthic zone ,Environmental science ,Organic matter ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology - Abstract
Jeong, D.U.; Lee, Y.G.; Kang, J.; Woo, H.J., and Choi, Y.H., 2020. Sediment geochemistry and benthic foraminiferal response to fish farming after conversion from a red laver (seaweed) farm. Journal of Coastal Research, 36(3), 559–574. Coconut Creek (Florida), ISSN 0749-0208.To understand the effects of biodeposits discharged from a fish farm (which was previously a red laver farm) on geochemistry of the sediment and benthic ecology, trace metals and element analyses, 210Pb dating, and benthic foraminiferal analyses were conducted on sediment cores collected below the fish farm cages. Sediment core sampling was also carried out at a control plot (160 m away) to understand the spreading of biodeposits. The geochemical effect of fish farming is pronounced. There was an increase in silt content and sedimentation fluxes of Znex (Zn in excess fractions), Cuex, Asex, and TPex (total phosphorus in excess fractions) after red laver farming. The silt content increased from 45.01% to 50.07%, with a sediment accumulation rate of ∼0.61 cm/y, on average. TPex, with 0.15% ± 0.06% on average, showed that the fish farming effects increased by 0.22% ± 0.07%. Znex, Cuex, Cdex, and Asex showed a positive relationship with TPex increase: 19.92 ± 1.79, 10.23 ± 3.99, 0.57 ± 0.19, and 0.92 ± 0.04 µg/cm2/y, respectively. The high sedimentation fluxes of Znex and Asex in the control plot may signify an expansion of influence of the fish farm by tidal currents. Seven benthic foraminifera appeared during the fish and red laver farming periods, with the dominant species being Cribroelphidium excavatum; however, they were characterized by a high similarity index of 88.1% and very low frequency of abundance, indicating bad habitat conditions. Among them, the C. excavatum–Ammonia beccarii–Ammonia ketienziensis–Cribroelphidium subarcticum assemblage ranged from 21 cm depth to the uppermost layer, characterized by increases in A. beccarii. This increase may have been caused by the accumulation of organic matter discharged from the fish farm after red laver farming, rather than from an increase in the trace metals. A. beccarii may be a species tolerant to fish farming.
- Published
- 2019
50. Influence of the KCNQ1 S140G Mutation on Human Ventricular Arrhythmogenesis and Pumping Performance: Simulation Study
- Author
-
Da Un Jeong and Ki Moo Lim
- Subjects
medicine.medical_specialty ,Physiology ,0206 medical engineering ,dominant frequency ,02 engineering and technology ,030204 cardiovascular system & hematology ,Ventricular tachycardia ,QT interval ,lcsh:Physiology ,reentry response ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,Internal medicine ,pumping performance ,medicine ,Sinus rhythm ,Original Research ,ventricular arrhythmia ,sinus rhythm response ,lcsh:QP1-981 ,business.industry ,Atrial fibrillation ,Sudden cardiac arrest ,Stroke volume ,medicine.disease ,020601 biomedical engineering ,KCNQ1 S140G mutation ,Ventricular fibrillation ,Mutation (genetic algorithm) ,cardiovascular system ,Cardiology ,medicine.symptom ,business ,electromechanical simulation - Abstract
The KCNQ1 S140G mutation, which is involved in IKs current, affects atrial fibrillation. However, little is known about its effect on the mechanical behavior of the heart. Therefore, we assessed the influence of the KCNQ1 S140G mutation on ventricular electrophysiological stability and mechanical pumping performance using a multi-scale model of cardiac electromechanics. An image-based electromechanical model was used to assess the effect on electrical propagation and arrhythmogenesis of the KCNQ1 S140G mutation. In addition, it was used to compare the mechanical response under the wild-type (WT) and S140G mutation conditions. The intracellular calcium transient obtained from the electrophysiological model was applied as an input parameter to a mechanical model to implement excitation–contraction coupling. The IKs current equation was modified to account for expression of the KCNQ1 S140G mutation, and it included a scaling factor (ϕ) for mutant expressivity. The WT and S140G mutation conditions were compared at the single-cell and three-dimensional (3D) tissue levels. The action potential duration (APD) was reduced by 60% by the augmented IKs current under the S140G mutation condition, which resulted in shorter QT interval. This reduced the 3D sinus rhythm wavelength by 60% and the sustained re-entry by 56%. However, pumping efficiency of mutant ventricles was superior in sinus rhythm condition. In addition, the shortened wavelength in cardiac tissue allowed a re-entrant circuit to form and increased the probability of sustaining ventricular tachycardia and ventricular fibrillation. In contrast, under the WT condition, a normal wavelength (20.8 cm) was unlikely to initiate and sustain re-entry in the cardiac tissue. Subsequently, the S140G mutant ventricles developed a higher dominant frequency distribution range (2.0–5.3 Hz) than the WT condition (2.8–3.7 Hz). In addition, stroke volume of mutant ventricles was reduced by 65% in sustained re-entry compared to the WT condition. In conclusion, signs of the S140G mutation might be difficult to identify in sinus rhythm even though the mutant ventricles show shortened QT interval. This suggests that the KCNQ1 S140G mutation increases the risk of death by sudden cardiac arrest. In addition, the KCNQ1 S140G mutation can induce ventricular arrhythmia and lessen ventricular contractility under re-entrant conditions.
- Published
- 2018
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