66 results on '"Jeon BG"'
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2. In Vitro Developmental Potential of Nuclear Transfer Embryos Cloned with Enucleation Methods using Pre-denuded Bovine Oocytes
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W.A. King, Jeon Bg, Gyu-Jin Rho, and Dean H. Betts
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Enucleation ,Embryo ,Biology ,Oocyte ,In vitro ,Andrology ,Polar body ,Cell nucleus ,Endocrinology ,medicine.anatomical_structure ,medicine ,Somatic cell nuclear transfer ,Animal Science and Zoology ,Blastocyst ,Biotechnology - Abstract
Enucleation of a recipient oocyte is an important essential process in the procedure of somatic cell nuclear transfer (SCNT). The present study investigated a method for the improvement of enucleation efficiency. Oocytes were denuded of cumulus cells before the completion of nuclear maturation (pre-denuded) after 12 h of culture at MI stage and subsequently cultured for additional 6 h until the completion of nuclear maturation and extrusion of the first polar body (PB1). The extrusion rate of PB1 was not significantly different in the pre-denuded oocyte group, compared with control oocyte group matured for 18 h. However, the number of oocytes showing the metaphase II (MII) located just underneath the PB1 was significantly higher (p
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- 2011
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3. Development of albumin monitoring system with hepatic hypoxia-on-a-chip.
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Kim J, Han Y, Jeon BG, Nam MS, Kwon S, Heo YJ, and Park M
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- Humans, Immunoassay methods, Liver, Hypoxia, Albumins, Lab-On-A-Chip Devices, Biosensing Techniques
- Abstract
Hypoxia plays an essential role in the pathogenesis of various liver diseases, and albumin is one of the important biomarkers secreted by the liver. In this study, we developed an albumin monitoring system composed of hepatic hypoxia-on-a-chip and an albumin sensor to study liver function change due to hypoxia. In hepatic hypoxia-on-a-chip, we vertically stack an oxygen-scavenging channel on a liver on a chip with a thin gas-permeable membrane in the middle. This unique design of the hepatic hypoxia-on-a-chip can help to induce hypoxia quickly, attaining <5% within 10 min. An electrochemical albumin sensor was fabricated based on the covalent immobilization of antibodies on the Au electrode to monitor albumin secreting function on the hepatic hypoxia-on-a-chip. Standard albumin samples spiked in PBS, and culture media were measured by the electrochemical impedance spectroscopy using the fabricated immunosensor. The LOD was calculated to be 10 ag/mL in both cases. Using the electrochemical albumin sensor, we measured albumin secretion in normoxia and hypoxia in the chips. The albumin concentration decreased to 27% after 24 h in hypoxia compared to normoxia. This response was consistent with physiological studies. With technical refinements, the present albumin monitoring system can be a powerful tool in studying hepatic hypoxia with real-time liver function monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2023
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4. Experimental signatures of nodeless multiband superconductivity in a [Formula: see text] single crystal.
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Kim C, Bhoi D, Sur Y, Jeon BG, Wulferding D, Min BH, Kim J, and Kim KH
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In order to understand the superconducting gap nature of a [Formula: see text] single crystal with [Formula: see text], in-plane thermal conductivity [Formula: see text], in-plane London penetration depth [Formula: see text], and the upper critical fields [Formula: see text] have been investigated. At zero magnetic field, it is found that no residual linear term [Formula: see text] exists and [Formula: see text] follows a power-law [Formula: see text] (T: temperature) with n = 2.66 at [Formula: see text], supporting nodeless superconductivity. Moreover, the magnetic-field dependence of [Formula: see text]/T clearly shows a shoulder-like feature at a low field region. The temperature dependent [Formula: see text] curves for both in-plane and out-of-plane field directions exhibit clear upward curvatures near [Formula: see text], consistent with the shape predicted by the two-band theory and the anisotropy ratio between the [Formula: see text](T) curves exhibits strong temperature-dependence. All these results coherently suggest that [Formula: see text] is a nodeless, multiband superconductor.
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- 2021
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5. Interleukin 10 level in the peritoneal cavity is a prognostic marker for peritoneal recurrence of T4 colorectal cancer.
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Jeong SY, Jeon BG, Kim JE, Shin R, Ahn HS, Jin H, and Heo SC
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- Aged, Colorectal Neoplasms metabolism, Colorectal Neoplasms surgery, Female, Follow-Up Studies, Humans, Male, Neoplasm Recurrence, Local metabolism, Neoplasm Recurrence, Local surgery, Peritoneal Neoplasms metabolism, Peritoneal Neoplasms surgery, Prognosis, ROC Curve, Retrospective Studies, Risk Factors, Survival Rate, Biomarkers, Tumor metabolism, Colorectal Neoplasms pathology, Interleukin-10 metabolism, Neoplasm Recurrence, Local pathology, Peritoneal Cavity pathology, Peritoneal Neoplasms secondary
- Abstract
Peritoneal recurrence (PR) is a major relapse pattern of colorectal cancer (CRC). We investigated whether peritoneal immune cytokines can predict PR. Cytokine concentrations of peritoneal fluid from CRC patients were measured. Patients were grouped according to peritoneal cancer burden (PCB): no tumor cells (≤ pT3), microscopic tumor cells (pT4), or gross tumors (M1c). Cytokine concentrations were compared among the three groups and the associations of those in pT4 patients with and without postoperative PR were assessed. Of the ten cytokines assayed, IL6, IL10, and TGFB1 increased with progression of PCB. Among these, IL10 was a marker of PR in pT4 (N = 61) patients based on ROC curve (p = 0.004). The IL10 cut-off value (14 pg/mL) divided patients into groups with a low (7%, 2 of 29 patients) or high (45%, 16 of 32 patients) 5-year PR (p < 0.001). Multivariable analysis identified high IL10 levels as the independent risk factor for PR. Separation of patients into training and test sets to evaluate the performance of IL10 cut-off model validated this cytokine as a risk factor for PR. Peritoneal IL10 is a prognostic marker of PR in pT4 CRC. Further research is necessary to identify immune response of intraperitoneal CRC growth.
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- 2021
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6. Evaluation of odonto/osteogenic differentiation potential from different regions derived dental tissue stem cells and effect of 17β-estradiol on efficiency.
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Son YB, Kang YH, Lee HJ, Jang SJ, Bharti D, Lee SL, Jeon BG, Park BW, and Rho GJ
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- Cell Differentiation, Cell Proliferation, Cells, Cultured, Estradiol pharmacology, Stem Cells, Dental Pulp, Osteogenesis
- Abstract
Background: The dentin is a tissue, which is formed by odontoblasts at the pulp interface of the teeth that supports the enamel. Odontoblasts, the cranial neural crest cells are derived from ectodermal mesenchymal stem cells (MSCs) and are long and polarized cells. They are present at the outer surface of dentin and play a prominent role about dentin formation. Recently, attention has been focused on induction of odontoblast using various type of MSCs and effects of the 17ß-estradiol supplementation. In this study, we establish an efficient odonto/osteoblast differentiation protocol using 17ß-estradiol supplementation while comparing the odonto/osteoblast ability of various dental MSCs., Methods: Same donor derived four types of dental MSCs namely dental pulp stem cells (DPSCs), stem cells from apical papilla (SCAP), dental follicle stem cells (DFSCs), and periodontal ligament stem cells (PDLSCs) were evaluated for their stemness characteristics and potency towards odonto/osteoblast (Induced odonto/osteoblast) differentiation. Then 17ß-estradiol supplementation of 0 and 10 µM was applied to the odonto/osteoblast differentiation media for 14 days respectively. Furthermore, mRNA and protein levels of odonto/osteoblast markers were evaluated., Results: All of the experimental groups displayed stemness characteristics by showing adipocyte and chondrocyte differentiation abilities, expression for cell surface markers and cell proliferation capacity without any significant differences. Moreover, all dental derived MSCs were shown to have odonto/osteoblast differentiation ability when cultured under specific conditions and also showed positive expression for odontoblast markers at both mRNA and protein level. Among all, DPSCs revealed the higher differentiation potential than other dental MSCs. Furthermore, odonto/osteoblast differentiation potential was enhanced by supplementing the differentiation media with 17ß-estradiol (E2)., Conclusions: Thus, DPSCs possess higher odonto/osteogenic potential than the SCAPs, DFSCs, PDLSCs and their differentiation capacity can by further enhanced under E2 supplementation.
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- 2021
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7. Terminal differentiation into adipocyte and growth inhibition by PPARγ activation in human A549 lung adenocarcinoma cells.
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Kim DY, Moon SH, Han JH, Kim MJ, Oh SJ, Bharti D, Lee SH, Park JK, Rho GJ, and Jeon BG
- Abstract
The present study investigated the terminal differentiation capacity into adipocytes and subsequent growth inhibition in A549 cancer cells treated with pioglitazone (PGZ), a PPARγ activator. The rate of cell growth in A549 cells was significantly ( P < .05) inhibited in concentrations above 10 μM PGZ while maintaining less cytotoxic effects in MRC-5 fibroblasts. Following 50 μM PGZ treatment, population doubling time (PDT) was significantly ( P < .05) increased by inhibition of cell growth, as per increasing PGZ exposure time by up to 4 weeks. The adiposome-like vesicles were commonly observed in the PGZ-treated A549 cells, and the vesicles were highly stained with Oil-Red O solution. In addition, the cell size and expression of GLUT4 and PPARγ were significantly ( P < .05) increased, as per increasing PGZ exposure time by up to 4 weeks. The significant ( P < .05) down-regulation of telomerase activity and up-regulation of senescence-associated β-galactosidase (SA β-GAL) activity was displayed in the PGZ-treated A549 cells, as per increasing PGZ exposure time by up to 4 weeks. The G1 phase of the cell cycle was also significantly ( P < .05) increased in the PGZ-treated A549 cells compared with untreated A549 cells. The present results have demonstrated that activation of PPARγ using PGZ induces cellular differentiation into adipocytes and inhibits cell growth in the A549 cancer cells. The terminal differentiation into adipocytes could offer potent chemotherapy in the cancer cells showing high glucose metabolism., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)
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- 2020
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8. Non-Contact Water Level Response Measurement of a Tubular Level Gauge Using Image Signals.
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Kim SW, Park DU, Jeon BG, and Chang SJ
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The occurrence of excessive fluid sloshing during an earthquake can damage structures used to store fluids and can induce secondary disasters, such as environmental destruction and human casualties, due to discharge of the stored fluids. Thus, to prevent such disasters, it is important to accurately predict the sloshing behavior of liquid storage tanks. Tubular level gauges, which visually show the fluid level of a liquid storage tank, are easy to install and economical compared to other water level gauges. They directly show the fluid level and can be applied for various fluids because they can be constructed with various materials according to the fluid characteristics and the intended use. Therefore, in this study, the shaking table test was conducted to verify the validity of the method for measuring the water level response of the tubular level gauge installed on a liquid storage tank using image signals. In addition, image enhancement methods were applied to distinguish between the float installed in the tubular level gauge and the gray level of the background.
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- 2020
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9. CT Scan Findings Can Predict the Safety of Delayed Appendectomy for Acute Appendicitis.
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Jeon BG, Kim HJ, and Heo SC
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- Acute Disease, Adult, Appendicitis surgery, Female, Humans, Incidence, Male, Postoperative Complications epidemiology, Predictive Value of Tests, Republic of Korea epidemiology, Retrospective Studies, Risk Factors, Appendectomy methods, Appendicitis diagnosis, Time-to-Treatment trends, Tomography, X-Ray Computed methods
- Abstract
Background: The relationship between duration of in-hospital waiting time and outcomes from appendectomy in patients with suspected appendicitis remains equivocal. The aim of this study was to investigate the influence of in-hospital waiting time on perforation rates and clinical outcomes in patients with suspected appendicitis who underwent appendectomy., Methods: A retrospective review of 5956 patients who underwent appendectomy at a single institution from January 2008 to December 2016 was performed. Patients were separated into two groups based on the duration from hospital arrival to surgery: patients with an in-hospital waiting time ≤ 12 h (no-delay group; n = 5287) and those with an in-hospital waiting time > 12 h (delayed group; n = 669). One-to-one propensity score matching (n = 421 per group) was performed to compare perforation rates and postoperative outcomes between the groups., Results: After propensity score matching, an in-hospital waiting time > 12 h was not associated with increased rates of perforation and significant complications, such as wound infection and abscess. However, in the matched cohorts and in the patients whose initial CT scans suggested perforated appendicitis, the delayed group had a higher risk of developing postoperative ileus (OR 9.18, 95% CI 1.16-72.74, p = 0.021; OR 2.17, 95% CI 1.03-4.59, p = 0.048, respectively) and longer postoperative length of hospital stay (87.38 vs. 79.07 h, p = 0.008; 161.61 vs. 130.87 h, p < 0.001, respectively) than the no-delay group., Conclusions: Our results indicate that a > 12-h in-hospital waiting time to surgery for appendicitis presents very little risk to the patient. However, the surgeon needs to carefully weigh the "safety" of a delay to surgery for appendicitis in patients whose initial CT scans suggested perforated appendicitis.
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- 2019
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10. Delay of cell growth and loss of stemness by inhibition of reverse transcription in human mesenchymal stem cells derived from dental tissue.
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Lee WC, Kim DY, Kim MJ, Lee HJ, Bharti D, Lee SH, Kang YH, Rho GJ, and Jeon BG
- Abstract
The present study investigated the cellular properties in the dental tissue-derived mesenchymal stem cells (DSCs) exposed to nevirapine (NVP), an inhibitor of reverse transcriptase (RTase). After a prolonged exposure of DSCs for 2 weeks, the population doubling time (PDT) was significantly ( P < .05) increased by delayed cell growth in the DSCs treated with 250 and 500 μM NVP, compared with untreated DSCs. Furthermore, the G1 phase of cell cycle with high activity of senescence-associated β-galactosidase was also significantly ( P < .05) increased in the 250 μM NVP-treated DSCs, compared with untreated DSCs. The level of telomerase activity was unchanged between control and treatment. However, following the treatment of NVP, negative surface markers for mesenchymal stem cells (MSCs), such as CD34 and CD45, were significantly ( P < .05) increased, while positive surface markers for MSCs, such as CD90 and CD105, were significantly ( P < .05) decreased in the NVP-treated DSCs than those of untreated DSCs. Furthermore, the differentiation capacity into mesodermal lineage was gradually decreased, and a significant ( P < .05) decrease of expression level of NANOG, OCT-4 and SOX-2 transcripts was observed in the DSCs treated with NVP, compared with untreated control DSCs. Taken together, the present results have revealed that inhibition of RTase by NVP induces delayed cell growth and loss of stemness., (© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group Korean Society for Integrative Biology.)
- Published
- 2019
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11. Formation of Polymer Walls through the Phase Separation of a Liquid Crystal Mixture Induced by a Spatial Elastic Energy Difference.
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Choi TH, Do SM, Jeon BG, Shin ST, and Yoon TH
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We propose a method to form polymer walls without the use of a photomask in a liquid crystal (LC) cell by phase separation of an LC mixture induced by a spatial elastic energy difference. When an in-plane electric field is applied to a vertically aligned cell filled with a mixture of LC and a reactive monomer (RM), a high spatial elastic energy is induced along the direction perpendicular to the interdigitated electrodes. RMs move to the boundaries where the elastic energy is very high and an in-plane component of the applied electric field exists, which results in the phase separation of the LC/RM mixture. We have shown that we can form polymer walls by applying ultraviolet light irradiation to the LC cell. These polymer walls can function as alignment layers. We observed morphological patterns of the polymer structure through polarized optical microscopy, scanning electron microscopy, and atomic force microscopy. The polymer walls formed in an LC cell can affect the orientation of LCs in the lateral direction. Bistable switching of a polymer-walled cell could be achieved by using three-terminal electrodes where both vertical and in-plane electric fields can be applied. Vertical anchoring with the alignment layer on each substrate allows LC molecules to remain vertically aligned after removal of the applied vertical electric field. Furthermore, in-plane anchoring with the formed polymer walls allows the LC molecules to remain homogeneously aligned after removal of the applied in-plane electric field. The proposed method for the formation of polymer structures could be a useful tool to fabricate LC cells for various applications. As a bistable phase-grating device, the diffraction efficiency of a polymer-walled cell was comparable to that of a pure-LC cell. Its operating voltage was 44% lower than that of a pure-LC cell owing to in-plane anchoring provided by the polymer walls. Moreover, it can be operated with very low power because it does not require power to maintain the state. In addition, the total response time of a polymer-walled cell was approximately 68% shorter than that of a pure-LC cell because all switching was forcibly controlled by applying an electric field.
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- 2019
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12. Independent control of haze and total transmittance with a dye-doped liquid crystal phase-grating device.
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Oh SW, Jeon BG, Choi TH, Do SM, and Yoon TH
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This paper presents a dye-doped liquid crystal (LC) phase-grating cell that is switchable between transparent, dark, and opaque states. The device can control haze and transmittance independently. Initially, LC and dye molecules are twist-aligned to make the cell opaque but haze-free due to the absorption of incident light without scattering. Switching to the transparent state could be achieved by applying a vertical electric field, whereas switching to the opaque state could be achieved by applying an in-plane electric field. It exhibited several advantages, such as a low switching voltage (<18 V) and fast response time (<30 ms).
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- 2019
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13. The clinical efficacy of stem cell therapy for complex perianal fistulas: a meta-analysis.
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Choi S, Jeon BG, Chae G, and Lee SJ
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- Humans, Treatment Outcome, Cutaneous Fistula surgery, Rectal Fistula surgery, Stem Cell Transplantation
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Background: Treatment of complex anal fistulas remains difficult. However, treatment with stem cells has had an encouraging success rate when applied to complex perianal fistulas. We systematically reviewed the current evidence through meta-analysis., Methods: We performed an electronic literature search on PubMed, Embase, and the Cochrane Library and identified studies (published between January 1946 and August 2017) that used stem cells to treat patients with complex perianal fistula. Each paper was evaluated for treatment success rate, target patients, types of stem cells used, number of cells used, and criteria for complete healing. Potential publication bias was assessed via visual inspection of a funnel plot and Orwin's fail-safe N. Out of 171 papers, 16 were included in the meta-analysis., Results: The overall healing rate of stem cell injection therapy for patients with complex perianal fistulas was 62.8% (95% CI 53.5-71.2, I
2 = 54.05%), whereas those for patients with Crohn's perianal fistulas alone and complex anal fistulas not associated with Crohn's disease were 64.1% and 61.5% (p = 0.840), respectively. Healing rates for autologous and allogenic stem cell treatment were 69.4% and 50.7% (p = 0.020), respectively. Four comparative studies out of 16 studies were analyzed separately. Stem cell therapy increased the healing rate compared to the control groups (OR 0.379, 95% CI 0.152-0.947)., Conclusions: Stem cell therapy is a good treatment option for complex perianal fistulas, which cannot be healed by conventional operative procedures. However, further research for additional supportive evidence, such as a large-scale randomized controlled trial, is required.- Published
- 2019
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14. Value of Additional Ultrasound Examination in Patients with Equivocal Computed Tomography Findings of Acute Appendicitis: Comparison with Computed Tomography Reassessment.
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Sim JY, Kim HJ, Jang SK, Yeon JW, Jeon BG, Ha YR, Paik SY, and Cho JS
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Objectives: The objective of this study was to find the diagnostic values of additional ultrasound (US) in patients with equivocal computed tomography (CT) findings of acute appendicitis, compared to CT reassessment., Materials and Methods: Patients with equivocal CT findings of acute appendicitis ( n = 115), who underwent the US, were included in the study. Two abdominal radiologists reviewed CT scans independently. They analyzed CT findings and made a diagnosis of acute appendicitis. The patients were categorized into positive and negative appendicitis based on the previous US reports. The diagnostic performance, interobserver agreement of CT findings, and appendicitis likelihood were calculated., Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of US (100%, 92.1%, 79.5%, and 100%, respectively) were higher than those of CT reassessment (reviewer 1: 51.9%, 87.5%, 56.1%, and 85.6%; reviewer 2: 66.7%, 85.2%, 58.1%, and 89.3%, respectively). In the coexistent inflammation group, the sensitivity, specificity, PPV, and NPV of US (reviewer 1: 100%, 98%, 91.5%, and 100%; reviewer 2: 100%, 98%, 87.7%, and 100%, respectively) were higher than those of CT reassessment (reviewer 1: 27.3%, 94.1%, 49.9%, and 85.8%; reviewer 2: 14.3%, 98.0%, 50.5%, and 88.9%, respectively)., Conclusion: In patients with equivocal CT findings of acute appendicitis, US shows better diagnostic performance than CT reassessment, and helps differentiate with periappendicitis., Competing Interests: There are no conflicts of interest.
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- 2019
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15. Low-power control of haze using a liquid-crystal phase-grating device with two-dimensional polymer walls.
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Choi TH, Do SM, Jeon BG, and Yoon TH
- Abstract
We propose a two-dimensional (2D) polymer-walled liquid-crystal (LC) phase-grating device, which can be used to control the haze with a very low power. 2D polymer walls can be formed in an LC cell through ultraviolet light irradiation while applying an in-plane electric field through phase separation induced by the spatial elastic energy difference. The transparent and translucent states can be realized by applying vertical and in-plane electric fields to the 2D polymer-walled LC cell, respectively. The cell can be operated with a very low power as the transparent [translucent] state is maintained even after the applied vertical [in-plane] electric field is removed. It consumes power only during state switching. The fabricated device exhibits outstanding performances, such as a very low operating voltage (< 10 V), low haze (< 2%) in the transparent state, high haze (> 90%) in the translucent state, and short switching time (< 2 ms), compared to those of other bistable LC devices, which can be used to control the haze.
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- 2019
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16. Inhibition of cell growth by cellular differentiation into adipocyte-like cells in dexamethasone sensitive cancer cell lines.
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Kim HI, Moon SH, Lee WC, Lee HJ, Shivakumar SB, Lee SH, Park BW, Rho GJ, and Jeon BG
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The stress responses in human body lead to secretion of cortisol hormone. The present study investigated the cellular responses on cell growth and cellular differentiation into adipocytes by exposure of synthetic stress hormone, dexamethasone (DEX) in various human cancer and normal cells. After prolonged exposure of cells with 1 μg/ml DEX for 2 weeks, population doubling time (PDT) was significantly ( P < .05) increased by inhibited cell growth in A-549 and MCF-7 cancer cells, and was unchanged in MDA-MB-231 cancer cells, normal MRC-5 fibroblasts, umbilical cord matrix-derived mesenchymal stem cells (UCMSCs) and dental papilla tissue-derived mesenchymal stem cells (DSCs). Whereas, PDT was significantly ( P < .05) decreased in U87-MG cancer cells by increased cell growth. Glucose uptake was significantly ( P < .05) increased in all the cancer cell lines compared to that in normal cell lines. Further, adiposome-like vesicles were noted in A-549 and MCF-7 cancer cells indicating retarded cell growth by DEX treatment, and the vesicles were stained with Oil-Red O solution. Further, the expression of adipocyte-specific genes such as glucose transporter type 4 (GLUT4), glucocorticoid receptors β (GR β ) and peroxisome proliferator-activated receptor γ (PPAR γ ) were significantly ( P < .05) increased in A-549 and MCF-7 with lipid vesicles. The level of telomerase activity was found to be significantly ( P < .05) downregulated in DEX-treated A-549 and MCF-7 cancer cells. Our results have clearly shown that DEX treatment induces inhibition of cell growth by differentiating into adipocyte-like cells in dexamethasone sensitive cancer cells.
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- 2018
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17. Sonographic Findings of Malignant Appendix Tumors in Seven Cases.
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Kwag KS, Kim HJ, Jang SK, Yeon JW, Paik S, Jeon BG, Kim KH, Park JH, and Shin E
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We report the sonographic features of confirmed malignant appendiceal tumors in seven cases. The histologic diagnoses of these tumors were mucinous cystadenocarcinoma ( n = 2), colonic type adenocarcinoma ( n = 4), and signet-ring cell carcinoma ( n = 1). The 2 mucinous cystadenocarcinomas showed mucocele type, which had markedly enlarged inner luminal diameters (mean, 23 mm; range, 15-31 mm) and thick, irregular walls (mean wall thickness, 5.5 mm; range, 5-6 mm). In contrast, the 5 nonmucinous carcinomas (4 adenocarcinomas and 1 signet-ring cell carcinoma) showed nonmucocele type, which had relatively small inner luminal diameters (mean ± standard deviation [SD], 6.6 ± 4.5 mm; range, 2-15 mm) and prominent wall thickening (mean wall thickness ± SD, 6.2 ± 2.3 mm; range, 3-10 mm). Of the 5 nonmucinous tumors, only one had a discernible mass, three had thick irregular walls, two had loss of the wall layer pattern, and four had submucosal hypoechogenicity. Regardless of the histologic type, five of the seven malignant appendiceal tumors showed a severe periappendiceal fat infiltration or periappendiceal abscess, suggestive of perforation. Although the sonographic findings of the malignant appendiceal tumors were nonspecific, some of the sonographic features seen in these seven cases may help radiologists consider the possibility of underlying malignant appendiceal tumors., Competing Interests: There are no conflicts of interest.
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- 2018
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18. Induction of telomere shortening and cellular apoptosis by sodium meta-arsenite in human cancer cell lines.
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Kim YD, Jang SJ, Lim EJ, Ha JS, Shivakumar SB, Jeong GJ, Rho GJ, and Jeon BG
- Abstract
The present study assessed the cytotoxicity of sodium meta-arsenite (SMA) on telomere shortening and cellular apoptosis in human A-549, MDA-MB-231 and U87-MG cancer cell lines. Following 2 weeks of 1 μM SMA treatment, population doubling time (PDT) was significantly ( P < .05) increased by the inhibition of cell proliferation in all the cancer cell lines compared to that in untreated controls. Level of telomerase activity by relative-quantitative telomerase repeat amplification protocol was significantly ( P < .05) downregulated by SMA treatment with significant ( P < .05) decrease of both telomerase reverse transcriptase and telomerase RNA component transcripts, responsible for telomerase activity. A significant ( P < .05) shortening of telomeric repeats by telomere restriction fragment analysis was consequently observed in SMA-treated cells. Moreover, high incidence of cells with senescence-associated β-glucosidase activity was observed in SMA-treated cells and some cells were also differentiated into adipocytes probably due to the loss of tumorous characterizations. Cellular apoptosis proven by DNA fragmentation was observed, and intrinsic apoptotic transcripts (BAX, caspase 3 and caspase 9) and stress-related transcripts (p21, HSP70 and HSP90) were significantly ( P < .05) increased in three cancer cell lines treated with SMA. Based on the present study, SMA treatment apparently induced a shortening of telomere length and cytotoxicity, such as induction of cell senescence, apoptosis and cell differentiation. Therefore, we conclude that SMA treatment at specific concentration can lead to gradual loss of tumorous characterizations and can be considered as a potential anti-cancer drug for chemotherapy treatment.
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- 2017
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19. Predictive factors and outcomes of negative appendectomy.
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Jeon BG
- Subjects
- Adolescent, Adult, Age Factors, Appendix diagnostic imaging, Female, Humans, Length of Stay statistics & numerical data, Leukocyte Count, Male, Operative Time, Patient Readmission statistics & numerical data, Postoperative Complications, Republic of Korea, Retrospective Studies, Severity of Illness Index, Tomography, X-Ray Computed, Young Adult, Appendectomy, Appendicitis surgery, Unnecessary Procedures
- Abstract
Background: The aim of this study was to assess predictive factors for negative appendectomy and to evaluate the outcomes of negative appendectomy., Methods: A retrospective chart review of 4,878 patients who underwent appendectomy at our institution from January 2008 to December 2014 was performed., Results: Younger age (≤15 years), normal white blood cell count, appendix diameter of less than 6 mm on computed tomography (CT), and CT grade less than 3 were found to be independent predictive factors for negative appendectomy. When complications were investigated according to the results of pathologic diagnosis, negative appendectomy had more complications than appendectomy for nonperforated appendicitis, and this was statistically significant., Conclusions: When CT findings are equivocal, in deciding to operate for acute appendicitis, additional ultrasonography can be performed. Furthermore, if the patient is younger than 15 years and the white blood cell count is normal, it is recommended to monitor changes in symptoms a little longer rather than operating hastily., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2017
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20. Quantitative Measurements of Size-Dependent Magnetoelectric Coupling in Fe 3 O 4 Nanoparticles.
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Yoo K, Jeon BG, Chun SH, Patil DR, Lim YJ, Noh SH, Gil J, Cheon J, and Kim KH
- Abstract
Bulk magnetite (Fe
3 O4 ), the loadstone used in magnetic compasses, has been known to exhibit magnetoelectric (ME) properties below ∼10 K; however, corresponding ME effects in Fe3 O4 nanoparticles have been enigmatic. We investigate quantitatively the ME coupling of spherical Fe3 O4 nanoparticles with uniform diameters (d) from 3 to 15 nm embedded in an insulating host, using a sensitive ME susceptometer. The intrinsic ME susceptibility (MES) of the Fe3 O4 nanoparticles is measured, exhibiting a maximum value of ∼0.6 ps/m at 5 K for d = 15 nm. We found that the MES is reduced with reduced d but remains finite until d = ∼5 nm, which is close to the critical thickness for observing the Verwey transition. Moreover, with reduced diameter the critical temperature below which the MES becomes conspicuous increased systematically from 9.8 K in the bulk to 19.7 K in the nanoparticles with d = 7 nm, reflecting the core-shell effect on the ME properties. These results point to a new pathway for investigating ME effect in various nanomaterials.- Published
- 2016
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21. Prolonged operative time in laparoscopic appendectomy: Predictive factors and outcomes.
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Jeon BG, Kim HJ, Jung KH, Kim SW, Park JS, Kim KH, Kim ID, and Lee SJ
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- Abscess epidemiology, Adolescent, Adult, Aged, Appendicitis diagnostic imaging, Appendicitis epidemiology, Appendicitis metabolism, C-Reactive Protein metabolism, Female, Humans, Laparoscopy statistics & numerical data, Length of Stay, Logistic Models, Male, Middle Aged, Multivariate Analysis, Organ Size, Postoperative Complications epidemiology, Retrospective Studies, Risk Factors, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Young Adult, Abscess surgery, Appendectomy statistics & numerical data, Appendicitis surgery, Operative Time, Overweight epidemiology
- Abstract
Introduction: To our knowledge, this study is the first to identify the predictive factors and outcomes of prolonged operative time associated with laparoscopic appendectomy. We aimed to identify preoperative factors that influence operation time and to determine how operative time affects laparoscopic appendectomy outcomes., Methods: The medical records of 3049 patients who had undergone laparoscopic appendectomy between January 2008 and December 2014 were retrospectively reviewed. Prolonged operative time was defined in the top 10% according to distribution (>90 min). A multivariate regression model was generated to assess potential predictive factors and outcomes of prolonged operative time., Results: In laparoscopic appendectomy for non-perforated appendicitis, independent factors that predict a prolonged operative time as identified through multivariate analysis were elevated C-reactive protein levels, symptom duration of more than 3 days, and computed tomography findings indicating an appendiceal diameter of more than 10 mm. In laparoscopic appendectomy for perforated appendicitis, overweight, elevated C-reactive protein, symptom duration of more than 3 days, and computed tomography findings of abscess were independent predictive factors for prolonged operative time. Prolonged surgery increases the risk of complications, prolonged hospital stay, and readmission., Conclusions: Overweight, elevated C-reactive protein, symptom duration of more than 3 days, appendiceal diameter of more than 10 mm, and abscess were independent predictive factors of prolonged operative time. Furthermore, prolonged operative time was associated with adverse postoperative outcomes after laparoscopic appendectomy., (Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)
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- 2016
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22. Giant suppression of phononic heat transport in a quantum magnet BiCu 2 PO 6 .
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Jeon BG, Koteswararao B, Park CB, Shu GJ, Riggs SC, Moon EG, Chung SB, Chou FC, and Kim KH
- Abstract
Thermal transport of quantum magnets has elucidated the nature of low energy elementary excitations and complex interplay between those excited states via strong scattering of thermal carriers. BiCu
2 PO6 is a unique frustrated spin-ladder compound exhibiting highly anisotropic spin excitations that contain both itinerant and localized dispersion characters along the b- and a-axes respectively. Here, we investigate thermal conductivity κ of BiCu2 PO6 under high magnetic fields (H) of up to 30 tesla. A dip-feature in κ, located at ~15 K at zero-H along all crystallographic directions, moves gradually toward lower temperature (T) with increasing H, thus resulting in giant suppression by a factor of ~30 near the critical magnetic field of Hc ≅ 23.5 tesla. The giant H- and T-dependent suppression of κ can be explained by the combined result of resonant scattering of phononic heat carriers with magnetic energy levels and increased phonon scattering due to enhanced spin fluctuation at Hc , unequivocally revealing the existence of strong spin-phonon coupling. Moreover, we find an experimental indication that the remaining magnetic heat transport along the b-axis becomes almost gapless at the magnetic quantum critical point realized at Hc .- Published
- 2016
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23. [A Case of Isolated Leptomeningeal Carcinomatosis from Advanced Gastric Cancer].
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Ji JG, Chung JW, Nam SW, Choi SK, Lee DW, Kim DI, Jeon BG, and Shin YJ
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- Adenocarcinoma diagnosis, Adenocarcinoma pathology, Aged, 80 and over, Basophils cytology, Brain diagnostic imaging, Endoscopy, Digestive System, Female, Humans, Magnetic Resonance Imaging, Meningeal Carcinomatosis secondary, Neoplasm Staging, Stomach Neoplasms pathology, Tomography, X-Ray Computed, Meningeal Carcinomatosis diagnosis, Stomach Neoplasms diagnosis
- Abstract
Leptomeningeal carcinomatosis (LMC) is rare metastatic form of gastric cancer. Most cases are diagnosed in the final stage after multiple distant metastasis. An 84-year-old woman was admitted with melena, headache and vomiting. Esophagogastroduodenoscopy showed an ulceroinfiltrating lesion at the stomach (Borrmann class III), and biopsy revealed a signet ring cell carcinoma. The abdominal-pelvic CT showed no evidence of metastasis. A sudden decrease of consciousness was noted, but the brain CT showed no active lesion while the brain MRI revealed enhancement of leptomeninges. A lumbar puncture was performed and the cerebrospinal fluid study revealed malignant neoplastic cells. With family consent, no further evaluation and treatment were administered and she died six weeks after the diagnosis of gastric cancer. We report an extremely rare case of a patient who initially presented with neurologic symptoms, and was diagnosed LMC from advanced gastric cancer without any evidence of metastasis in abdomen and pelvis.
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- 2016
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24. Interplay of charge density wave and multiband superconductivity in 2H-PdxTaSe2.
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Bhoi D, Khim S, Nam W, Lee BS, Kim C, Jeon BG, Min BH, Park S, and Kim KH
- Abstract
2H-TaSe2 has been one of unique transition metal dichalcogenides exhibiting several phase transitions due to a delicate balance among competing electronic ground states. An unusual metallic state at high-T is sequentially followed by an incommensurate charge density wave (ICDW) state at ≈122 K and a commensurate charge density wave (CCDW) state at ≈90 K, and superconductivity at TC ~ 0.14 K. Upon systematic intercalation of Pd ions into TaSe2, we find that CCDW order is destabilized more rapidly than ICDW to indicate a hidden quantum phase transition point at x ~ 0.09-0.10. Moreover, TC shows a dramatic enhancement up to 3.3 K at x = 0.08, ~24 times of TC in 2H-TaSe2, in proportional to the density of states N(EF). Investigations of upper critical fields Hc2 in single crystals reveal evidences of multiband superconductivity as temperature-dependent anisotropy factor γH = , quasi-linear increase of , and an upward, positive-curvature in near TC. Furthermore, analysis of temperature-dependent electronic specific heat corroborates the presence of multiple superconducting gaps. Based on above findings and electronic phase diagram vs x, we propose that the increase of N(EF) and effective electron-phonon coupling in the vicinity of CDW quantum phase transition should be a key to the large enhancement of TC in PdxTaSe2.
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- 2016
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25. Initial experience of transanal total mesorectal excision with rigid or flexible transanal platforms in cadavers.
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Kim MJ, Park JW, Ha HK, Jeon BG, Shin R, Ryoo SB, Choi SJ, Park BK, Park KJ, and Jeong SY
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- Aged, Aged, 80 and over, Biopsy, Cadaver, Humans, Male, Middle Aged, Anal Canal surgery, Digestive System Surgical Procedures methods, Laparoscopy methods, Rectal Neoplasms surgery, Rectum surgery
- Abstract
Background: Transanal total mesorectal excision (taTME) is expected to provide benefits in the removal of the complete mesorectum for low rectal lesions, and several clinical studies regarding this technique have been reported. However, a transanal platform has not yet been standardized, and diverse transanal endoluminal surgery access devices have been used, based on individual surgeon preferences. In the present study, we performed laparoscopy-assisted taTME in cadavers and compared the characteristics of four different platforms., Methods: Between January 2013 and April 2015, laparoscopy-assisted taTME was performed on six fresh cadavers. Flexible [SILS™ Port (Covidien), GelPOINT(®) Path Transanal Access Platform (Applied Medical)] and rigid [TEO(®) (Karl Storz Endoskope), TEM (Richard Wolf)] transanal access platforms were used on three cadavers each., Results: All cadavers were male, with a mean age of 69.2 (range 57-86) years. The mean operation time was 146.3 (range 140-155) min with flexible platforms and 206.7 (range 150-260) min with rigid platforms. The mean specimen length was 23 (range 18-26) cm. Complete or nearly complete mesorectal specimens were obtained in all cases, except for one case using the TEM platform. Flexible platforms (SILS and GelPOINT) provided a short set-up time, relatively atraumatic retraction, and easy application of familiar laparoscopic instruments; a narrow operative field was its limitation. The rigid platforms (TEO and TEM) enabled larger and more stable operative fields and space than did the SILS platform, but they were limited by a narrow view, prolonged set-up time, rigidity, and long channels relative to the short distance from the anus to the rectal closure site., Conclusion: In this preliminary study, laparoscopy-assisted taTME was a feasible and safe procedure using both rigid and soft platforms, despite some limitations of each platform.
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- 2016
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26. Appendectomy: Should it Be Performed So Quickly?
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Jeon BG, Kim HJ, Jung KH, Lim HI, Kim SW, Park JS, Kim KH, and Kim ID
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- Adolescent, Adult, Analysis of Variance, Appendicitis diagnosis, Databases, Factual, Emergency Treatment methods, Female, Humans, Length of Stay, Male, Middle Aged, Multivariate Analysis, Postoperative Complications physiopathology, Prognosis, Republic of Korea, Retrospective Studies, Risk Assessment, Severity of Illness Index, Treatment Outcome, Young Adult, Appendectomy adverse effects, Appendectomy methods, Appendicitis surgery, Postoperative Complications epidemiology, Time-to-Treatment
- Abstract
Controversy surrounds appendectomy timings and their effects on postoperative outcomes. This study evaluated the influence of hospital delays on perforation rates and complications in patients with acute appendicitis. From January 2008 to December 2013, the cases of 4148 consecutive patients who had undergone appendectomies for suspected appendicitis were reviewed. The patients' demographic data, times from symptom onset to hospital arrival (prehospital delay), times from hospital arrival to surgery (hospital delay), histological findings, and postoperative outcomes were documented. Perforation rates and complications were assessed at each time interval between symptom onset and surgery. Perforation rates and complications increased with longer prehospital delays, but no correlations were evident between hospital delays and perforation rates or between hospital delays and complications. Although delaying appendectomies for >18 hours had no statistically significant impact on perforation rates (25.3 vs 19.4%, P = 0.133), it caused more complications (8.7 vs 3.8%, P = 0.023) compared with cases delayed for 12 to 18 hours. Multivariate analyses determined that hospital delays were not associated with increased risks of perforation, complications, wound infections, or intra-abdominal abscesses. However, a >18-hour hospital delay was associated with a significantly increased risk of postoperative ileus (odds ratio = 2.94, 95% confidence interval = 1.17-7.41, P = 0.022). Hospital delays were not associated with significantly increased risks of perforation and complications. However, patients with perforated appendicitis had higher risks of developing postoperative ileus if hospital delays were >18 hours. Therefore, hospital delays of ≤18 hours are safe, but caution is required if delays are >18 hours.
- Published
- 2016
27. Erratum: Biofeedback Therapy Before Ileostomy Closure in Patients Undergoing Sphincter-Saving Surgery for Rectal Cancer: A Pilot Study.
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Kim JK, Jeon BG, Song YS, Seo MS, Kwon YH, Park JW, Ryoo SB, Jeong SY, and Park KJ
- Abstract
[This corrects the article on p. 138 in vol. 31, PMID: 26361615.].
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- 2015
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28. Precise autofocus method employing normalized fluorescence image size in a two-photon polymerization nanofabrication system.
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Jeon BG, Jung BJ, Kong HJ, and Cho YH
- Abstract
The autofocus method has been investigated to improve the precise positioning of a substrate surface at the center of the laser focal spot in two-photon polymerization (TPP) nanofabrication. For this purpose, we developed a novel autofocus method using normalized image size, which was calculated with the second momentum radius (SMR) of two-photon induced fluorescence (TPIF). The SMR of TPIF was theoretically analyzed and experimentally compared with the average intensity of TPIF for various input laser powers. The results show that the proposed method enhanced the precision and robustness of autofocus in TPP. Specifically, the experimental creation of ascending voxel arrays demonstrated both the method's immunity to input laser power change, and a high precision of ±0.045 μm. To test the practical feasibility of the proposed autofocus method, 300 μm×260 μm single-layer honey-comb structures were successfully fabricated with precompensation and dynamic compensation using the proposed autofocus method.
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- 2015
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29. Biofeedback Therapy Before Ileostomy Closure in Patients Undergoing Sphincter-Saving Surgery for Rectal Cancer: A Pilot Study.
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Kim JK, Jeon BG, Song YS, Seo MS, Kwon YH, Park JW, Ryoo SB, Jeong SY, and Park KJ
- Abstract
Purpose: This study prospectively investigated the effects of biofeedback therapy on objective anorectal function and subjective bowel function in patients after sphincter-saving surgery for rectal cancer., Methods: Sixteen patients who underwent an ileostomy were randomized into two groups, one receiving conservative management with the Kegel maneuver and the other receiving active biofeedback before ileostomy closure. Among them, 12 patients (mean age, 57.5 years; range, 38 to 69 years; 6 patients in each group) completed the study. Conservative management included lifestyle modifications, Kegel exercises, and medication. Patients were evaluated at baseline and at 1, 3, 6, and 12 months after ileostomy closure by using anal manometry, modified Wexner Incontinence Scores (WISs), and fecal incontinence quality of life (FI-QoL) scores., Results: Before the ileostomy closure, the groups did not differ in baseline clinical characteristics or resting manometric parameters. After 12 months of follow-up, the biofeedback group demonstrated a statistically significant improvement in the mean maximum squeezing pressure (from 146.3 to 178.9, P = 0.002). However, no beneficial effect on the WIS was noted for biofeedback compared to conservative management alone. Overall, the FI-QoL scores were increased significantly in both groups after ileostomy closure (P = 0.006), but did not differ significantly between the two groups., Conclusion: Although the biofeedback therapy group demonstrated a statistically significant improvement in the maximum squeezing pressure, significant improvements in the WISs and the FI-QoL scores over time were noted in both groups. The study was terminated early because no therapeutic benefit of biofeedback had been demonstrated.
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- 2015
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30. Development and gene expression of porcine cloned embryos derived from bone marrow stem cells with overexpressing Oct4 and Sox2.
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Lee JH, Lee WJ, Jeon RH, Lee YM, Jang SJ, Lee SL, Jeon BG, Ock SA, King WA, and Rho GJ
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- Animals, Apoptosis, Cell Differentiation, Cells, Cultured, Embryo Culture Techniques veterinary, Embryonic Development, Gene Expression Regulation, Developmental, Homeodomain Proteins genetics, Homeodomain Proteins metabolism, Nuclear Transfer Techniques veterinary, Octamer Transcription Factor-3 genetics, SOXB1 Transcription Factors genetics, Swine, Transfection, Cloning, Organism methods, Mesenchymal Stem Cells metabolism, Octamer Transcription Factor-3 metabolism, SOXB1 Transcription Factors metabolism
- Abstract
The present study compared the potential of porcine bone marrow mesenchymal stem cells (pBMSCs) at different passages as nuclear transfer (NT) donors and the developmental efficiency of NT embryos from donor cells transfected with/without Oct4 and Sox2. Early-passage pBMSCs showed higher proliferation and expression of Oct4 and Sox2 and differentiation potential into mesenchymal lineages than middle- and late-passage pBMSCs. Cleavage rate did not differ among pBMSCs at different passages, but NT embryos with early-passage pBMSCs and middle-passage pBMSCs transfected with Oct4 (Oct4-pBMSCs) had significantly (p<0.05) higher blastocyst development than those with middle-passage pBMSCs. The incidence of apoptotic bodies in NT blastocysts from late-passage pBMSCs and Sox2-transfected middle-passage pBMSCs (Sox2-pBMSCs) was significantly (p<0.05) higher than others. The transcriptional levels of Oct4, Sox2, Nanog, Cdx2, Dnmt3a, and Igf2r genes were significantly (p<0.05) higher in Oct4- and Sox2-pBMSCs NT embryos. Middle-passage pBMSCs NT embryos revealed lower transcriptional levels of Bcl2 than others, except Sox2-pBMSCs NT embryos. The transcriptional level of Bax increased gradually in NT embryos derived from pBMSCs following extended passages and was significantly (p<0.05) higher in Sox2-pBMSCs NT embryos. Our results demonstrated that early-passage pBMSCs are more potent in expressing transcription factors and displayed higher differentiation ability, and middle-passage pBMSCs transfected with Oct4 improved the developmental efficiency of NT embryos, suggesting that high Oct4 expression cells are more efficient as NT donors.
- Published
- 2014
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31. Electrical control of large magnetization reversal in a helimagnet.
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Chai YS, Kwon S, Chun SH, Kim I, Jeon BG, Kim KH, and Lee S
- Abstract
Reversal of magnetization M by an electrical field E has been a long-sought phenomenon in materials science because of its potential for applications such as memory devices. However, the phenomenon has rarely been achieved and remains a considerable challenge. Here we report the large M reversal by E in a multiferroic Ba0.5Sr1.5Zn2(Fe0.92Al0.08)12O22 crystal without any external magnetic field. Upon sweeping E through the range of ±2 MV m(-1), M varied quasi-linearly in the range of ±2 μB per f.u., resulting in the M reversal. Strong electrical modulation of M at zero magnetic field were observable up to ~\n150 K. Nuclear magnetic resonance measurements provided microscopic evidence that the electric field and the magnetic field play equivalent roles in modulating the volume of magnetic domains. Our results suggest that the soft ferrimagnetism and the associated transverse conical state are key ingredients to achieve the large magnetization reversal at fairly high temperatures.
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- 2014
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32. Rectourethral fistula: systemic review of and experiences with various surgical treatment methods.
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Choi JH, Jeon BG, Choi SG, Han EC, Ha HK, Oh HK, Choe EK, Moon SH, Ryoo SB, and Park KJ
- Abstract
Purpose: A rectourethral fistula (RUF) is an uncommon complication resulting from surgery, radiation or trauma. Although various surgical procedures for the treatment of an RUF have been described, none has gained acceptance as the procedure of choice. The aim of this study was to review our experience with surgical management of RUF., Methods: The outcomes of 6 male patients (mean age, 51 years) with an RUF who were operated on by a single surgeon between May 2005 and July 2012 were assessed., Results: The causes of the RUF were iatrogenic in four cases (two after radiation therapy for rectal cancer, one after brachytherapy for prostate cancer, and one after surgery for a bladder stone) and traumatic in two cases. Fecal diversion was the initial treatment in five patients. In one patient, fecal diversion was performed simultaneously with definitive repair. Four patients underwent staged repair after a mean of 12 months. Rectal advancement flaps were done for simple, small fistula (n = 2), and flap interpositions (gracilis muscle flap, n = 2; omental flap, n = 1) were done for complex or recurrent fistulae. Urinary strictures and incontinence were observed in patients after gracilis muscle flap interposition, but they were resolved with simple treatments. The mean follow-up period was 28 months, and closure of the fistula was achieved in all five patients (100%) who underwent definitive repairs. The fistula persisted in one patient who refused further definitive surgery after receiving only a fecal diversion., Conclusion: Depending on the severity and the recurrence status of RUF, a relatively simple rectal advancement flap repair or a more complex gracilis muscle or omental flap interposition can be used to achieve closure of the fistula.
- Published
- 2014
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33. Characterisation and differentiation of porcine ovarian theca-derived multipotent stem cells.
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Lee YM, Kumar BM, Lee JH, Lee WJ, Kim TH, Lee SL, Ock SA, Jeon BG, Park BW, and Rho GJ
- Subjects
- Alkaline Phosphatase genetics, Alkaline Phosphatase metabolism, Animals, Biomarkers, Cell Cycle physiology, Cell Differentiation, Female, Gene Expression Regulation physiology, Membrane Proteins, Multipotent Stem Cells cytology, Multipotent Stem Cells physiology, Swine physiology, Theca Cells cytology, Theca Cells physiology
- Abstract
In this study, the cellular properties and in vitro differentiation capacity of porcine ovarian theca-derived multipotent stem cells (TSCs) were examined. Isolated TSCs were expanded into a homogeneous population that had a typical fibroblast-shaped morphology and was positive for alkaline phosphatase activity. Cell cycle analysis indicated that TSCs had high proliferative potential. Flow cytometry analysis demonstrated expression of mesenchymal cell surface markers (CD29, CD44 and CD90) on TSCs. Among three pluripotent markers tested (OCT4, NANOG and SOX2), only SOX2 was expressed in TSCs at protein and mRNA levels. Cytochemical staining demonstrated that TSCs differentiated in vitro into osteocytes and adipocytes. Lineage specific transcripts expressed by differentiated osteocytes including osteonectin, osteocalcin and RUNX2. Lineage specific transcripts expressed by differentiated adipocytes included adipocyte fatty acid binding protein-2 (aP2) and peroxisome proliferator-activated receptor-γ2. Following induction in oogenesis media, TSCs exhibited sequential changes in morphology, resembling oocyte-like cells (OLCs), and expressed transcription factors (OCT4, NANOG and SOX2), oocyte-specific marker genes (GDF9B, C-MOS, DAZL, VASA, ZPC, SCP3 and STELLA) and the folliculogenesis marker follicular stimulating hormone receptor. These results indicated that TSCs derived from ovarian follicles are capable of differentiating into mesenchymal lineages and OLCs., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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34. PbCu3TeO7: an S = 1/2 staircase kagome lattice with significant intra-plane and inter-plane couplings.
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Koteswararao B, Kumar R, Chakraborty J, Jeon BG, Mahajan AV, Dasgupta I, Kim KH, and Chou FC
- Abstract
We have synthesized polycrystalline and single-crystal samples of PbCu3TeO7 and studied its properties via magnetic susceptibility, χ(T), and heat-capacity, Cp(T), measurements and also electronic structure calculations. Whereas the crystal structure is suggestive of the presence of a quasi-2D network of Cu(2+) (S = 1/2) buckled staircase kagome layers, the χ(T) data show magnetic anisotropy and three magnetic anomalies at temperatures TN1 ∼ 36 K, TN2 ∼ 25 K, and TN3 ∼ 17 K. The χ(T) data follow the Curie-Weiss law above 200 K and a Curie-Weiss temperature θCW ∼- 150 K is obtained. The data deviate from the simple Curie-Weiss law below 200 K, which is well above TN1, suggesting the presence of competing magnetic interactions. The magnetic anomaly at TN3 appears to be of first order from magnetization measurements, although our Cp(T) results do not display any anomaly at TN3. The hopping integrals obtained from our electronic structure calculations suggest the presence of significant intra-kagome (next-nearest neighbor and diagonal) and inter-kagome couplings. These couplings take the PbCu3TeO7 system away from a disordered ground state and lead to long-range order, in contrast to what might be expected for an ideal (isotropic) 2D kagome system.
- Published
- 2013
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35. Field- and temperature-induced evolution of the magnetocaloric effect in Ba0.3Sr1.7Co2Fe12O22 single crystals with heliconical magnetism.
- Author
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Yan LQ, Chun SH, Sun Y, Shin KW, Jeon BG, Shen SP, and Kim KH
- Abstract
The magnetocaloric effect (MCE) associated with the spin transitions of alternating longitudinal conical (ALC)-mixed conical (MC) and MC-ferrimagnetic (FIM) states in a Ba0.3Sr1.7Co2Fe12O22 single crystal has been investigated. For magnetic field directions applied along either the [120] or [001] directions, the crystal is found to exhibit the conventional and inverse MCE near the ALC-MC (T(N1) = 235 K) and MC-FIM (T(N2) = 348 K) states, respectively. The dependence of the magnetic entropy on the magnetic field also exhibits such sign change behaviors in the MCE, which is attributed to the magnetic field induced gradual collapse of heliconical magnetic order.
- Published
- 2013
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36. Individualized Cutoff Value of the Preoperative Carcinoembryonic Antigen Level is Necessary for Optimal Use as a Prognostic Marker.
- Author
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Jeon BG, Shin R, Chung JK, Jung IM, and Heo SC
- Abstract
Purpose: Carcinoembryonic antigen (CEA) is an important prognostic marker in colorectal cancer (CRC). However, in some stages, it does not work. We performed this study to find a way in which preoperative CEA could be used as a constant prognostic marker in harmony with the TNM staging system., Methods: Preoperative CEA levels and recurrences in CRC were surveyed. The distribution of CEA levels and the recurrences in each TNM stage of CRC were analyzed. An optimal cutoff value for each TNM stage was calculated and tested for validity as a prognostic marker within the TNM staging system., Results: The conventional cutoff value of CEA (5 ng/mL) was an independent prognostic factor on the whole. However, when evaluated in subgroups, it was not a prognostic factor in stage I or stage III of N2. A subgroup analysis according to TNM stage revealed different CEA distributions and recurrence rates corresponding to different CEA ranges. The mean CEA levels were higher in advanced stages. In addition, the recurrence rates of corresponding CEA ranges were higher in advanced stages. Optimal cutoff values from the receiver operating characteristic curves were 7.4, 5.5, and 4.5 ng/mL for TNM stage I, II, and III, respectively. Those for N0, N1, and N2 stages were 5.5, 4.8, and 3.5 ng/mL, respectively. The 5-year disease-free survivals were significantly different according to these cutoff values for each TNM and N stage. The multivariate analysis confirmed the new cutoff values to be more efficient in discriminating the prognosis in the subgroups of the TNM stages., Conclusion: Individualized cutoff values of the preoperative CEA level are a more practical prognostic marker following and in harmony with the TNM staging system.
- Published
- 2013
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37. Improvement of range precision in laser detection and ranging system by using two Geiger mode avalanche photodiodes.
- Author
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Kim TH, Kong HJ, Jo SE, Jeon BG, Oh MS, Heo A, and Park DJ
- Abstract
In this paper, the improvement of range precision in a laser detection and ranging (LADAR) system by using two Geiger mode avalanche photodiodes (GmAPDs) is described. The LADAR system is implemented by using two GmAPDs with a beam splitter and applying comparative process to their ends. Then, the timing circuit receives the electrical signals only if each GmAPDs generates electrical signals simultaneously. Though this system decreases the energy of a laser-return pulse scattered from the target, it is effective in reducing the range precision. The experimental results showed that the average value of standard deviation of time of flights was improved from 61 mm to 37 mm when the pulse energy is 0.6 μJ. When the time bin width is 0.5 ns, the single-shot precision error of the LADAR system was also improved from 280 mm to 67 mm.
- Published
- 2013
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38. Transplantation of porcine umbilical cord matrix mesenchymal stem cells in a mouse model of Parkinson's disease.
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Kang EJ, Lee YH, Kim MJ, Lee YM, Kumar BM, Jeon BG, Ock SA, Kim HJ, and Rho GJ
- Subjects
- Animals, Behavior, Animal, Biomarkers metabolism, Bone Marrow Cells cytology, Cell Differentiation, Cell Lineage, Disease Models, Animal, Flow Cytometry, Fluorescence, Interleukin-6 metabolism, Mesoderm cytology, Mice, Mice, Inbred C57BL, Nerve Growth Factor metabolism, Neurogenesis, Neurons cytology, Oxidopamine, Phenotype, Rotarod Performance Test, Substantia Nigra enzymology, Substantia Nigra pathology, Tyrosine 3-Monooxygenase metabolism, Vascular Endothelial Growth Factor A metabolism, Mesenchymal Stem Cell Transplantation, Mesenchymal Stem Cells cytology, Parkinson Disease therapy, Umbilical Cord cytology
- Abstract
The present study compared mesenchymal stem cells derived from umbilical cord matrix (UCM-MSCs) with bone marrow (BM-MSCs) of miniature pigs on their phenotypic profiles and ability to differentiate in vitro into osteocytes, adipocytes and neuron-like cells. This study further evaluated the therapeutic potential of UCM-MSCs in a mouse Parkinson's disease (PD) model. Differences in expression of some cell surface and cytoplasm specific markers were evident between UCM-MSCs and BM-MSCs. However, the expression profile indicated the primitive nature of UCM-MSCs, along with their less or non-immunogenic features, compared with BM-MSCs. In vitro differentiation results showed that BM-MSCs had a higher tendency to form osteocytes and adipocytes, whereas UCM-MSCs possessed an increased potential to transform into immature or mature neuron-like cells. Based on these findings, UCM-MSCs were transplanted into the right substantia nigra (SN) of a mouse PD model. Transplantation of UCM-MSCs partially recovered the mouse PD model by showing an improvement in basic motor behaviour, as assessed by rotarod and bridge tests. These observations were further supported by the expression of markers, including nestin, tyrosine hydroxylase (TH), neuronal growth factor (NGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6), at the site of cell transplantation. Our findings of xenotransplantation have collectively suggested the potential utility of UCM-MSCs in developing viable therapeutic strategies for PD., (Copyright © 2011 John Wiley & Sons, Ltd.)
- Published
- 2013
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39. Epigenetic modification of fetal fibroblasts improves developmental competency and gene expression in porcine cloned embryos.
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Kumar BM, Maeng GH, Lee YM, Lee JH, Jeon BG, Ock SA, Kang T, and Rho GJ
- Subjects
- Acetylation, Animals, Cloning, Organism veterinary, DNA Methylation, DNA-Cytosine Methylases genetics, DNA-Cytosine Methylases metabolism, Fertilization in Vitro veterinary, Histone Acetyltransferases genetics, Histone Acetyltransferases metabolism, Histone Deacetylases genetics, Histone Deacetylases metabolism, Histones genetics, Histones metabolism, Embryo, Mammalian embryology, Epigenesis, Genetic, Fibroblasts metabolism, Gene Expression Regulation, Developmental, Nuclear Transfer Techniques veterinary, Sus scrofa embryology
- Abstract
Treatment of somatic cells with DNA methylation and histone deacetylation inhibitors has been hypothesized to improve the potential reprogramming after nuclear transfer (NT). The objective of this study was to investigate the developmental competence and gene expression during the porcine preimplantation development of in vitro fertilized (IVF) and embryos cloned with porcine fetal fibroblasts (pFF) (pFF-NT), and pFF treated by 0.5 μM 5-azacytidine (5-azaC) (pFF+5-azaC-NT) or 1.0 mM sodium butyrate (NaB) (pFF+NaB-NT). IVF embryos had significantly (P < 0.05) higher blastocyst rates (27.7 ± 2.6 %) and total cell numbers (46.7 ± 3.9). However, NT embryos from pFF+5-azaC and pFF+NaB showed enhanced developmental potential with significantly (P < 0.05) higher rates of blastocysts (21.3 ± 2.9 % and 22.4 ± 1.7 %, respectively) than those from pFF (15.1 ± 2.5 %). Further, NT embryos from pFF+5-azaC and pFF+NaB (33.8 ± 4.1 and 35.7 ± 5.2, respectively) had significantly (P < 0.05) higher total cell numbers than those from pFF (24.6 ± 3.5). Differential expression pattern of genes involved in DNA methylation (DNA methyltransferases- DNMT1, DNMT2, DNMT3A and DNMT3B), histone acetylation (histone acetyltransferase 1- HAT1) and histone deacetylation (histone deacetylases- HDAC1, HDAC2 and HDAC3) were observed in NT embryos when compared to IVF counterparts. However, the relative expressions of genes in pFF+5-azaC-NT and pFF+NaB-NT groups were largely comparable to those of IVF embryos than pFF-NT embryos. In conclusion, modification of the epigenetic status by reducing DNA methylation or enhancing histone acetylation levels in pFF improved the developmental rates, total cell number and the transcription profile of porcine NT embryos. Thus, somatic cells with relatively hypomethylated or hyperacetylated genome may enhance reprogramming efficiency in porcine NT.
- Published
- 2013
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40. Analysis of risk factors for the development of incisional and parastomal hernias in patients after colorectal surgery.
- Author
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Song IH, Ha HK, Choi SG, Jeon BG, Kim MJ, and Park KJ
- Abstract
Purpose: The purpose of this study was to evaluate the overall rate and risk factors for the development of an incisional hernia and a parastomal hernia after colorectal surgery., Methods: The study cohort consisted of 795 consecutive patients who underwent open colorectal surgery between 2005 and 2007 by a single surgeon. A retrospective analysis of prospectively collected data was performed., Results: The overall incidence of incisional hernias was 2% (14/690). This study revealed that the cumulative incidences of incisional hernia were 1% at 12 months and 3% after 36 months. Eighty-six percent of all incisional hernias developed within 3 years after a colectomy. The overall rate of parastomal hernias in patients with a stoma was 6.7% (7/105). The incidence of parastomal hernias was significantly higher in the colostomy group than in the ileostomy group (11.9% vs. 0%; P = 0.007). Obesity, abdominal aortic aneurysm, American Society of Anesthesiologists score, serum albumin level, emergency surgery and postoperative ileus did not influence the incidence of incisional or parastomal hernias. However, the multivariate analysis revealed that female gender and wound infection were significant risk factors for the development of incisional hernias female: P = 0.009, wound infection: P = 0.041). There were no significant factors related to the development of parastomal hernias., Conclusion: Our results indicate that most incisional hernias develop within 3 years after a colectomy. Female gender and wound infection were risk factors for the development of an incisional hernia after colorectal surgery. In contrast, no significant factors were found to be associated with the development of a parastomal hernia.
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- 2012
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41. Neurogenic and cardiomyogenic differentiation of mesenchymal stem cells isolated from minipig bone marrow.
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Kumar BM, Maeng GH, Lee YM, Kim TH, Lee JH, Jeon BG, Ock SA, Yoo JG, and Rho GJ
- Subjects
- Adipocytes physiology, Animals, Antigens, Surface genetics, Antigens, Surface metabolism, Biomarkers, Bone Marrow Cells physiology, Cell Culture Techniques methods, Cell Culture Techniques veterinary, Chondrocytes physiology, Flow Cytometry, Fluorescent Antibody Technique, Gene Expression Regulation physiology, Mesenchymal Stem Cells physiology, Osteocytes physiology, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Swine, Bone Marrow Cells cytology, Cell Differentiation physiology, Mesenchymal Stem Cells cytology, Myocytes, Cardiac cytology, Neurons cytology, Swine, Miniature physiology
- Abstract
The present study investigated the potential of minipig bone marrow-mesenchymal stem cells (BM-MSCs) to differentiate in vitro into neuron- and cardiomyocyte-like cells. Isolated BM-MSCs exhibited a fibroblast-like morphology, expressed CD29, CD44 and CD90, and differentiated into osteocytes, adipocytes and chondrocytes. Upon induction in two different neuronal specific media, most of BM-MSCs acquired the distinctive morphological features and positively stained for nestin, neurofilament-M (NF-M), neuronal nuclei (NeuN), β-tubulin, galactocerebroside (Gal-C) and glial fibrillary acidic protein (GFAP). Expression of nestin, GFAP and NF-M was further demonstrated by RT-PCR and RT-qPCR. Following cardiomyogenic induction, MSCs exhibited a stick-like morphology with extended cytoplasmic processes, and formed cluster-like structures. The expression of cardiac specific markers α-smooth muscle actin, cardiac troponin T, desmin and α-cardiac actin was positive for immunofluorescence staining, and further confirmed by RT-PCR and RT-qPCR. In conclusion, our results showed the in vitro differentiation ability of porcine BM-MSCs into neuron-like and cardiomyocyte-like cells., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
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- 2012
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42. Developmental expression of lineage specific genes in porcine embryos of different origins.
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Kumar BM, Maeng GH, Jeon RH, Lee YM, Lee WJ, Jeon BG, Ock SA, and Rho GJ
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- Animals, Biomarkers metabolism, Cell Count, Ectoderm cytology, Ectoderm metabolism, Embryo, Mammalian metabolism, Endoderm cytology, Endoderm metabolism, Fertilization in Vitro methods, Fibroblasts cytology, Fibroblasts metabolism, GATA6 Transcription Factor genetics, GATA6 Transcription Factor metabolism, Mesenchymal Stem Cells metabolism, Nuclear Transfer Techniques, Oocytes cytology, Oocytes metabolism, Parthenogenesis, RNA, Messenger genetics, RNA, Messenger metabolism, SOXB1 Transcription Factors genetics, SOXB1 Transcription Factors metabolism, Swine, Transcription, Genetic, Cell Lineage, Embryo, Mammalian cytology, Embryonic Development, Gene Expression Regulation, Developmental, Mesenchymal Stem Cells cytology
- Abstract
Purpose: This study compared the expression of genes involved in pluripotency, segregation of inner cell mass (ICM) and trophectoderm (TE), and primitive endoderm (PE) formation in porcine embryos produced by in vitro fertilization (IVF), parthenogenetic activation (PA), and nuclear transfer (NT) using either fetal fibroblasts (FF-NT) or mesenchymal stem cells (MSC-NT)., Methods: Blastocyst formation and total cell number were analyzed. The expression patterns of transcripts, including SRY-related HMG-box gene 2 (SOX2), reduced expression gene 1 (REX1/ZFP42), LIN28, caudal type homeobox 2 (CDX2), TEA domain family member 4 (TEAD4), integrin beta 1 (ITGB1) and GATA6 were assessed at the 4-8 cell and blastocyst stage embryos by real-time PCR., Results: Developmental rates to blastocyst stage and total cell number were higher in IVF and PA embryos than in NT embryos. But MSC-NT embryos had increased blastocyst formation and higher total cell number compared to FF-NT embryos. The relative expressions of transcripts were higher in blastocysts than in 4-8 cell stage embryos. The mRNA expression levels of SOX2 and REX1 were largely similar in embryos of different origins. However, the genes such as LIN28, CDX2, TEAD4, ITGB1 and GATA6 showed the differential expression pattern in PA and NT embryos compared to IVF embryos. Importantly, the transcript levels in MSC-NT embryos were relatively less variable to IVF than those in FF-NT embryos., Conclusion: MSCs seem to be better donors for porcine NT as they improved the developmental competency, and influenced the expression pattern of genes quite similar with IVF embryos than that of FFs.
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- 2012
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43. Observation of multiferroic properties in pyroxene NaFeGe2O6.
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Kim I, Jeon BG, Patil D, Patil S, Nénert G, and Kim KH
- Abstract
We report the observation of multiferroicity in a clinopyroxene NaFeGe(2)O(6) polycrystal from the investigation of its electrical and magnetic properties. Following the previously known first magnetic transition at T(N1) = 13 K, a second magnetic transition appears at T(N2) = 11.8 K in the temperature dependence of the magnetization. A ferroelectric polarization starts to develop clearly at T(N2) rather than T(N1) and its magnitude increases up to ~13 μC m(-2) at 5 K, supporting the idea that the ferroelectric state in NaFeGe(2)O(6) stems from a helical spin order stabilized below T(N2). When a magnetic field of 90 kOe is applied, the electric polarization decreases to 9 μC m(-2) and T(N2) slightly increases by 0.5 K. At intermediate magnetic fields, around 28 and 78 kOe, anomalies in the magnetoelectric current, magnetoelectric susceptibility, and field derivative of magnetization curves are found, indicating field-induced spin-state transitions. Based on these electrical and magnetic properties, we provide a detailed low temperature phase diagram up to 90 kOe, and discuss the nature of each phase of NaFeGe(2)O(6).
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- 2012
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44. Electric field control of nonvolatile four-state magnetization at room temperature.
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Chun SH, Chai YS, Jeon BG, Kim HJ, Oh YS, Kim I, Kim H, Jeon BJ, Haam SY, Park JY, Lee SH, Chung JH, Park JH, and Kim KH
- Abstract
We find the realization of large converse magnetoelectric (ME) effects at room temperature in a magnetoelectric hexaferrite Ba0.52Sr2.48Co2Fe24O41 single crystal, in which rapid change of electric polarization in low magnetic fields (about 5 mT) is coined to a large ME susceptibility of 3200 ps/m. The modulation of magnetization then reaches up to 0.62μ(B)/f.u. in an electric field of 1.14 MV/m. We find further that four ME states induced by different ME poling exhibit unique, nonvolatile magnetization versus electric field curves, which can be approximately described by an effective free energy with a distinct set of ME coefficients.
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- 2012
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45. Low levels of X-inactive specific transcript in somatic cell nuclear transfer embryos derived from female bovine freemartin donor cells.
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Jeon BG, Rho GJ, Betts DH, Petrik JJ, Favetta LA, and King WA
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- Animals, Cattle, Cloning, Organism, Embryo Transfer veterinary, Embryonic Development, Female, Fetal Death genetics, Fetal Death veterinary, Male, Pregnancy, RNA, Long Noncoding, RNA, Messenger analysis, RNA, Untranslated genetics, Real-Time Polymerase Chain Reaction veterinary, Telomerase metabolism, Embryo, Mammalian metabolism, Freemartinism genetics, Genes, X-Linked genetics, Nuclear Transfer Techniques veterinary, X Chromosome genetics, X Chromosome Inactivation genetics
- Abstract
The present study compared developmental potential, telomerase activity and transcript levels of X-linked genes (HPRT, MECP2, RPS4X, SLC25A6, XIAP, XIST and ZFX) in bovine somatic cell nuclear transfer (SCNT) embryos reconstructed with cells derived from a freemartin (female with a male co-twin) or from normal female cattle (control). The rates of cleavage, development to blastocyst and hatched blastocyst stage, and the mean numbers of total and inner cell mass cells in the freemartin SCNT embryos were not significantly different from those of control SCNT embryos (p > 0.05). The levels of telomerase activity analyzed by RQ-TRAP in the freemartin SCNT embryos were also similar to those of the normal SCNT embryos. Transcript levels of HPRT, MECP2, RPS4X and XIAP, measured by quantitative real-time RT-PCR, were not significantly different between the control and freemartin SCNT embryos (p > 0.05). However, the transcript levels of SLC25A6, XIST and ZFX were significantly decreased in the freemartin SCNT embryos compared to control SCNT embryos (p < 0.05). Transfer of 71 freemartin SCNT embryos to 22 recipient cows resulted in 4 (18%) pregnancies, which were lost between days 28 and 90 of gestation. Taken together, the present study demonstrates that the transcript levels of several X-linked genes, especially XIST, showed an aberrant pattern in the freemartin SCNT embryos, suggesting aberrant X inactivation in freemartin clones which may affect embryo survival., (Copyright © 2011 S. Karger AG, Basel.)
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- 2012
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46. In vitro developmental potential of nuclear transfer embryos cloned with enucleation methods using pre-denuded bovine oocytes.
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Jeon BG, Betts DH, King WA, and Rho GJ
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- Animals, Cell Nucleus, Fibroblasts, Polar Bodies, Cattle embryology, Cloning, Organism veterinary, Embryo Culture Techniques veterinary, Nuclear Transfer Techniques veterinary, Oocytes cytology
- Abstract
Enucleation of a recipient oocyte is an important essential process in the procedure of somatic cell nuclear transfer (SCNT). The present study investigated a method for the improvement of enucleation efficiency. Oocytes were denuded of cumulus cells before the completion of nuclear maturation (pre-denuded) after 12 h of culture at MI stage and subsequently cultured for additional 6 h until the completion of nuclear maturation and extrusion of the first polar body (PB1). The extrusion rate of PB1 was not significantly different in the pre-denuded oocyte group, compared with control oocyte group matured for 18 h. However, the number of oocytes showing the metaphase II (MII) located just underneath the PB1 was significantly higher (p<0.05) in the pre-denuded oocyte group than those in control oocyte group. To test the effect of pre-denuding on the enucleation rate and developmental potential of embryos to blastocyst stage, subsequent somatic cell nuclear transfer comparisons were made with three different methods of enucleation at MII stage using vital dyes (demicoline and Hoescht) or the PB1 (blind enucleation) to localize the chromosome plate. Enucleation rate of the oocytes with demicoline, Hoechst and pre-denuding enucleation groups were significantly higher (p<0.05) than those of blind enucleation groups. However, cleavage rate to two-cell stage and, developmental rate to blastocyst and hatched blastocyst stage, the mean numbers of total and ICM cells in the SCNT embryos with Hoechst enucleation groups were significantly decreased (p<0.05), compared to those of blind, demicoline and pre-denuding enucleation groups. Moreover, the level of telomerase activity was also significantly (p<0.05) decreased in SCNT blastocysts of Hoechst enucleation group, compared to those of blind, demicoline and pre-denuding enucleation groups. Taken together, pre-denuding enucleation group using pre-denuded oocytes was a useful and simple enucleation method for bovine SCNT embryos., (© 2011 Blackwell Verlag GmbH.)
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- 2011
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47. Differential cytotoxic effects of sodium meta-arsenite on human cancer cells, dental papilla stem cells and somatic cells correlate with telomeric properties and gene expression.
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Jeon BG, Kumar BM, Kang EJ, Maeng GH, Lee YM, Hah YS, Ock SA, Kwack DO, Park BW, and Rho GJ
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- Cell Line, Tumor, Drug Screening Assays, Antitumor, Enzyme Inhibitors pharmacology, Gene Expression Profiling, Humans, Inhibitory Concentration 50, Models, Statistical, Telomerase antagonists & inhibitors, Tetrazolium Salts pharmacology, Thiazoles pharmacology, Arsenites pharmacology, Dental Papilla cytology, Gene Expression Regulation, Gene Expression Regulation, Neoplastic, Sodium Compounds pharmacology, Stem Cells cytology, Telomere ultrastructure
- Abstract
We investigated the effects of sodium meta-arsenite (NaAsO(2)) on human cancer cells (MDA-MB-231, MCF-7 and U-87 MG), dental papilla tissue stem cells (DPSCs) and somatic cells [MRC-5 fetal fibroblasts and adult muscle cells (MCs)] by examining telomeric properties, endogenous reverse transcriptase (RT) activity and the expression of tumorigenesis-linked genes. Half maximal inhibitory concentration (IC(50)) values were higher in DPSCs and MCs, possessing longer telomere lengths when compared to cancer cells. Levels of telomerase and RT activity, and the expression of protein 53 (p53), B-cell lymphoma 2 (BCL2), nuclear factor kappa-light-chain-enhancer of activated B-cells (NFκB), transforming growth factor beta (TGFβ) and vascular endothelial growth factor (VEGF) were significantly lower in cancer cells following sodium meta-arsenite treatment, whereas the effect was absent or marginally detected in DPSCs and somatic cells. Collectively, sodium meta-arsenite effectively induced cellular cytotoxicity by inhibiting telomerase and RT activity, and down-regulating transcript levels in cancer cells with shorter telomere lengths, whereas more tolerance was evident in DPSCs and somatic cells possessing longer telomere lengths.
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- 2011
48. Influence of epidermal growth factor supplementation during in vitro maturation on nuclear status and gene expression of canine oocytes.
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Song HJ, Kang EJ, Maeng GH, Ock SA, Lee SL, Yoo JG, Jeon BG, and Rho GJ
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- Animals, Connexins genetics, Connexins metabolism, ErbB Receptors genetics, ErbB Receptors metabolism, Female, RNA, Messenger genetics, RNA, Messenger metabolism, Receptors, LH genetics, Receptors, LH metabolism, Dogs physiology, Epidermal Growth Factor pharmacology, In Vitro Oocyte Maturation Techniques veterinary, Oocytes physiology
- Abstract
This study evaluated the effect of epidermal growth factor (EGF) supplementation during in vitro maturation on the meiotic status and the expression of EGF receptor (EGFr), luteinizing hormone receptor (LHr) and gap junction protein α 5 (GJA5) in canine cumulus-oocyte-complexes (COCs). COCs of ≥110 μm diameter, exhibiting dark pigmentation and completely surrounded by three or more layers of cumulus cells collected from anestrus stage ovaries in natural cycle were matured in TCM-199 supplemented with 10% fetal bovine serum, 0.57 mM cysteine, 10 μg/ml LH and FSH, and different concentrations of EGF (0, 10 and 30 ng/ml). Oocytes cultured for 72 h were fixed to assess the nuclear maturation. Expression of EGFr, LHr and GAJ5 was assessed by immunocytochemistry and real-time PCR. Proportion of metaphase II status of oocytes cultured in in vitro maturation (IVM) medium supplemented with 10 ng/ml EGF for 72 h was significantly (P<0.05) higher than 0 and 30 ng/ml EGF supplemented IVM medium (9.8% vs. 6.5% and 5.2%). In both cumulus cells and oocytes, EGFr protein was undetectable, LHr protein level of expression was low and a strong expression of GJA5 protein was observed. The relative abundance (RA) of EGFr transcript revealed low levels and the LHr expression decreased steadily with addition of EGF. However it did not vary among different concentrations of EGF supplementation. The RA of GJA5 transcript exhibited lower level at 10 ng/ml EGF supplementation. In conclusion, the supplementation of 10 ng/ml EGF in IVM media exerted a positive influence on the progression of maturation to MII phase and the expression level of GJA5 at 72 h, but did not demonstrate any stimulatory role on the expression of EGFr and LHr during the maturation of the canine IVM oocytes., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
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- 2011
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49. Concurrent transition of ferroelectric and magnetic ordering near room temperature.
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Ko KT, Jung MH, He Q, Lee JH, Woo CS, Chu K, Seidel J, Jeon BG, Oh YS, Kim KH, Liang WI, Chen HJ, Chu YH, Jeong YH, Ramesh R, Park JH, and Yang CH
- Subjects
- Temperature, Electricity, Ferric Compounds chemistry, Magnetics
- Abstract
Strong spin-lattice coupling in condensed matter gives rise to intriguing physical phenomena such as colossal magnetoresistance and giant magnetoelectric effects. The phenomenological hallmark of such a strong spin-lattice coupling is the manifestation of a large anomaly in the crystal structure at the magnetic transition temperature. Here we report that the magnetic Néel temperature of the multiferroic compound BiFeO(3) is suppressed to around room temperature by heteroepitaxial misfit strain. Remarkably, the ferroelectric state undergoes a first-order transition to another ferroelectric state simultaneously with the magnetic transition temperature. Our findings provide a unique example of a concurrent magnetic and ferroelectric transition at the same temperature among proper ferroelectrics, taking a step toward room temperature magnetoelectric applications.
- Published
- 2011
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50. Autofocusing method using fluorescence detection for precise two-photon nanofabrication.
- Author
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Jung BJ, Kong HJ, Jeon BG, Yang DY, Son Y, and Lee KS
- Abstract
We propose a method capable of focusing a laser beam on a substrate automatically via fluorescence detection from the resin of a two-photon nanofabrication system. When two-photon absorption (TPA) occurs by focusing the laser beam in the resin, fluorescence is emitted from the focusing region in the visible range. The total pixel number above the threshold value of the fluorescence images obtained by a CCD camera is plotted on a graph in accordance with the focus position. By searching for the position when the total pixel number undergoes an abrupt change in the pre-TPA region, the correct configuration of the focused laser beam can be found. Through focusing tests conducted at four vertices of a 500 μm x 500 μm square placed arbitrarily inside SCR500 resin, the errors of the autofocusing method were found to range from -100 nm to + 200 nm. Moreover, this method does not leave any polymerized marks. To verify the usefulness of the autofocusing method, the fabrication of a pyramid structure consisting of 20 layers was attempted on a coverglass. It was completely fabricated without losing a layer.
- Published
- 2011
- Full Text
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