600 results on '"Hyun Ok Kim"'
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2. In vitro erythrocyte production using human-induced pluripotent stem cells: determining the best hematopoietic stem cell sources
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Youn Keong Cho, Hyun-Kyung Kim, Soon Sung Kwon, Su-Hee Jeon, June-Won Cheong, Ki Taek Nam, Han-Soo Kim, Sinyoung Kim, and Hyun Ok Kim
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Erythropoiesis ,Hematopoietic stem cells ,Human-induced pluripotent stem cell ,Red blood cell ,Medicine (General) ,R5-920 ,Biochemistry ,QD415-436 - Abstract
Abstract Background Blood transfusion is an essential part of medicine. However, many countries have been facing a national blood crisis. To address this ongoing blood shortage issue, there have been efforts to generate red blood cells (RBCs) in vitro, especially from human-induced pluripotent stem cells (hiPSCs). However, the best source of hiPSCs for this purpose is yet to be determined. Methods In this study, hiPSCs were established from three different hematopoietic stem cell sources—peripheral blood (PB), cord blood (CB) and bone marrow (BM) aspirates (n = 3 for each source)—using episomal reprogramming vectors and differentiated into functional RBCs. Various time-course studies including immunofluorescence assay, quantitative real-time PCR, flow cytometry, karyotyping, morphological analysis, oxygen binding capacity analysis, and RNA sequencing were performed to examine and compare the characteristics of hiPSCs and hiPSC-differentiated erythroid cells. Results hiPSC lines were established from each of the three sources and were found to be pluripotent and have comparable characteristics. All hiPSCs differentiated into erythroid cells, but there were discrepancies in differentiation and maturation efficiencies: CB-derived hiPSCs matured into erythroid cells the fastest while PB-derived hiPSCs required a longer time for maturation but showed the highest degree of reproducibility. BM-derived hiPSCs gave rise to diverse types of cells and exhibited poor differentiation efficiency. Nonetheless, erythroid cells differentiated from all hiPSC lines mainly expressed fetal and/or embryonic hemoglobin, indicating that primitive erythropoiesis occurred. Their oxygen equilibrium curves were all left-shifted. Conclusions Collectively, both PB- and CB-derived hiPSCs were favorably reliable sources for the clinical production of RBCs in vitro, despite several challenges that need to be overcome. However, owing to the limited availability and the large amount of CB required to produce hiPSCs, and the results of this study, the advantages of using PB-derived hiPSCs for RBC production in vitro may outweigh those of using CB-derived hiPSCs. We believe that our findings will facilitate the selection of optimal hiPSC lines for RBC production in vitro in the near future.
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- 2023
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3. Human induced pluripotent stem cell line banking for the production of rare blood type erythrocytes
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Yu Jin Park, Su-Hee Jeon, Hyun-Kyung Kim, Eun Jung Suh, Seung Jun Choi, Sinyoung Kim, and Hyun Ok Kim
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Induced pluripotent stem cell ,Rare blood type ,Red blood cell differentiation ,Stem cell banking ,Medicine - Abstract
Abstract Background The in vitro production of mature human red blood cells (RBCs) from induced pluripotent stem cells (iPSCs) has been the focus of research to meet the high demand for blood transfusions. However, limitations like high costs and technological requirements restrict the use of RBCs produced by iPSC differentiation to specific circumstances, such as for patients with rare blood types or alloimmunized patients. In this study, we developed a detailed protocol for the generation of iPSC lines derived from peripheral blood of donors with O D-positive blood and rare blood types (D–and Jr(a-)) and subsequent erythroid differentiation. Methods Mononuclear cells separated from the peripheral blood of O D-positive and rare blood type donors were cultured to produce and expand erythroid progenitors and reprogrammed into iPSCs. A 31-day serum-free, xeno-free erythroid differentiation protocol was used to generate reticulocytes. The stability of iPSC lines was confirmed with chromosomal analysis and RT-PCR. Morphology and cell counts were determined by microscopy observations and flow cytometry. Results Cells from all donors were successfully used to generate iPSC lines, which were differentiated into erythroid precursors without any apparent chromosomal mutations. This differentiation protocol resulted in moderate erythrocyte yield per iPSC. Conclusions It has previously only been hypothesized that erythroid differentiation from iPSCs could be used to produce RBCs for transfusion to patients with rare blood types or who have been alloimmunized. Our results demonstrate the feasibility of producing autologous iPSC-differentiated RBCs for clinical transfusions in patients without alternative options.
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- 2020
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4. Comparative study of substrate free and amniotic membrane scaffolds for cultivation of limbal epithelial sheet
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Hyun Jung Lee, Sang Min Nam, Sae Kyung Choi, Kyoung Yul Seo, Hyun Ok Kim, and So-Hyang Chung
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ATP-binding Cassette Sub-family G Member 2 (ABCG2) ,Limbal Stem Cell Deficiency (LSCD) ,Outgrowth Sheets ,Limbal Explants ,Low JC ,Medicine ,Science - Abstract
Abstract Transplantation of cultivated limbal epithelial transplantation has been proven to restore the corneal surface in limbal stem cell deficiency (LSCD). Here we comparatively investigated the optimized conditions and the efficiency of limbal epithelial sheet growth in three media conditions as well as with substrate free (transwell), human amniotic membrane (HAM) sutured onto transwell inserts (HAMTW), and HAM slide scaffold (HAMS). Outcomes evaluated were outgrowth sheet size from limbal explants, expression of stem/progenitor cell markers p63α, ABCG2 and CK15, and colony formation efficiency (CFE). Additionally, limbal epithelial sheets on HAMS were transplanted into corneas of LSCD rabbit models. Limbal epithelial sheets with 5% human AB serum showed the greatest increase in ABCG2 efflux activity (JC1low), p63α expression, and CFE compared in both conditions without HAM and with HAM, respectively. The outgrowth sheet size, cell yield, and Ki67 expression were increased in limbal epithelial sheets on HAMS compared to transwell and HAMTW. ABCG2 efflux activity, p63α and CK15 expressions, and CFE were also increased in limbal epithelial sheets on HAMS as well. In corneas of transplanted rabbit LSCD models, p63α expressions were noted in the basal layers and CK12 expressions were observed in superficial layers. Cultivation of limbal epithelial sheet on HAMS with xeno-free medium enhances the growth and stemness of limbal epithelial sheets.
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- 2018
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5. Platelet storage induces accelerated desialylation of platelets and increases hepatic thrombopoietin production
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Jooyoung Cho, Hyunkyung Kim, Jaewoo Song, June-Won Cheong, Jeong Won Shin, Woo Ick Yang, and Hyun Ok Kim
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Platelet storage lesion (PSL) ,Desialylation ,Thrombopoietin (TPO) ,Ashwell–Morell receptor (AMR) ,Medicine - Abstract
Abstract Background Stored platelets undergo deleterious changes, referred to as platelet storage lesions (PSLs), which accelerate the desialylation of platelets and result in their phagocytosis and clearance by hepatic macrophages. Recent studies have reported that Ashwell–Morell receptor binds to desialylated platelets, thereby inducing hepatic thrombopoietin (TPO) production in a mouse model. Therefore, this study aimed to demonstrate these relationships between PSL and hepatic TPO production in human study. Methods Platelet concentrates (PCs) were obtained from 5 healthy volunteers and the remaining were discarded samples from the blood bank. PCs were divided into two halves, and stored either at 22 or 4 °C. Experiments were conducted using serial samples. Desialylation was assessed using flow cytometry, and structural changes were visualized using electron microscopy. Following co-culture of HepG2 cells (HB-8065, ATCC) with isolated platelets, hepatic TPO production was determined using real-time quantitative polymerase chain reaction and the supernatant TPO level was measured using a Luminex kit. Results For 5 days of storage duration, platelet counts were not influenced by the storage conditions, but the degree of desialylation was proportional to the storage duration. Significant changes in the platelet surface and structure according to storage conditions were noted in electron microscopy. HepG2 cells incubated with aged platelets expressed more TPO mRNA, and supernatant TPO levels were proportional to the storage duration. Refrigeration also influenced on the results of this study, but they were not statistically significant. Conclusions This is the first study to demonstrate that, in vitro, aging and refrigeration affect the integrity of human platelets, resulting in induction of hepatic TPO mRNA and protein expression.
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- 2018
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6. A 1-month-old infant with chylomicronemia due to gene mutation treated by plasmapheresis
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Mo Kyung Jung, Juhyun Jin, Hyun Ok Kim, Ahreum Kwon, Hyun Wook Chae, Seok Jin Kang, Duk Hee Kim, and Ho-Seong Kim
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Chylomicronemia ,GPIHBP1 ,Plasmapheresis ,Pediatrics ,RJ1-570 - Abstract
Chylomicronemia is a severe type of hypertriglyceridemia characterized by chylomicron accumulation that arises from a genetic defect in intravascular lipolysis. It requires urgent and proper management, because serious cases can be accompanied by pancreatic necrosis or persistent multiple organ failure. We present the case of a 1-month-old infant with chylomicronemia treated by plasmapheresis. His chylomicronemia was discovered incidentally when lactescent plasma was noticed during routine blood sampling during a hospital admission for fever and irritability. Laboratory investigation revealed marked triglyceridemia (>5,000 mg/dL) with high chylomicron levels. We therefore decided to perform a therapeutic plasmapheresis to prevent acute pancreatitis. Sequence analysis revealed a homozygous novel mutation in exon 4 of GPIHBP1: c.476delG (p.Gly159Alafs). Glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1) stabilizes the binding of chylomicrons near lipoprotein lipase and supports lipolysis. Mutations of GPIHBP1, the most recently discovered gene, can lead to severe hyperlipidemia and are known to make up only 2% of the monogenic mutations associated with chylomicronemia. The patient maintains mild hypertriglyceridemia without rebound after single plasmapheresis and maintenance fibrate medication so far. Here, we report an infant with chylomicronemia due to GPIHBP1 mutation, successfully treated by plasmapheresis.
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- 2017
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7. Adipose-Derived Mesenchymal Stem Cells Promote M2 Macrophage Phenotype through Exosomes
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June Seok Heo, Youjeong Choi, and Hyun Ok Kim
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Internal medicine ,RC31-1245 - Abstract
Accumulating evidence has shown that the paracrine factors derived from mesenchymal stem cells (MSCs) are capable of regulating the immune system via interaction with various immune cells. In this study, adipose-derived MSCs (AdMSCs) and human peripheral blood monocytes (PBMCs) were isolated and cultured to examine the effects of MSC-induced macrophages (iMΦ) on inflammation and immune modulation. Indirect coculture with MSCs increased the expression of arginase-1 and mannose receptor (CD206), markers of activated M2 macrophages, in the PBMCs demonstrating that MSC-secreted factors promoted M2-MΦ polarization. Additionally, iMΦ exhibited a similar higher inhibitory effect on the growth of activated T cells compared to that in the other groups (AdMSCs only, AdMSCs plus iMΦ), implying that iMΦ can play a sufficient functional role. Interestingly, the population of FoxP3 Treg cells significantly increased when cocultured with iMΦ, suggesting that iMΦ have an immunomodulatory effect on the Treg cells through the modulation of the FoxP3 expression. Notably, iMΦ expressed high levels of immunosuppressive and anti-inflammatory cytokines, namely IL-10 and TSG-6. Furthermore, we confirmed that the AdMSC-derived exosomes modulated macrophage polarization by upregulating the expression of M2 macrophage markers. Conclusively, our results suggest that iMΦ play a significant role in regulating the immunomodulatory- and inflammatory-mediated responses. Thus, iMΦ may be used as a novel stem cell-based cell-free therapy for the treatment of immune-mediated inflammatory disorders.
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- 2019
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8. Direct Control of Stem Cell Behavior Using Biomaterials and Genetic Factors
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Jeong-Kee Yoon, Mi-Lan Kang, Joo Hyun Park, Kyoung-Mi Lee, Young Min Shin, Jin Woo Lee, Hyun Ok Kim, and Hak-Joon Sung
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Internal medicine ,RC31-1245 - Abstract
Stem cells have recently emerged as an important candidate for cell therapy. However, some major limitations still exist such as a small quantity of cell supply, senescence, and insufficient differentiation efficiency. Therefore, there is an unmet need to control stem cell behavior for better clinical performance. Since native microenvironment factors including stem cell niche, genetic factors, and growth factors direct stem cell fate cooperatively, user-specified in vitro settings are required to understand the regulatory roles and effects of each factor, thereby applying the factors for improved cell therapy. Among others, various types of biomaterials and transfection method have been employed as key tools for development of the in vitro settings. This review focuses on the current strategies to improve stemness maintenance, direct differentiation, and reprogramming using biomaterials and genetic factors without any aids from additional biochemicals and growth factors.
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- 2018
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9. Long-Term Follow-Up of Patients after Autologous Bone Marrow Cell Infusion for Decompensated Liver Cirrhosis
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Ja Kyung Kim, Soo-Jeong Kim, Yuri Kim, Yong Eun Chung, Young Nyun Park, Hyun Ok Kim, Jin Seok Kim, Mi-Suk Park, Isao Sakaida, Do Young Kim, Jung Il Lee, Sang Hoon Ahn, Kwan Sik Lee, and Kwang-Hyub Han M.D.
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Medicine - Abstract
Although several human clinical trials using various bone marrow-derived cell types for cirrhotic or decompensated patients have reported a short-term benefit, long-term follow-up data are limited. We analyzed the long-term clinical outcomes of autologous bone marrow cell infusion (ABMI) for decompensated liver cirrhosis (LC). Patients enrolled in a pilot single-armed ABMI study were followed up more than 5 years. Bone marrow-derived mononuclear cells (BM-MNCs) from decompensated LC were harvested and after processing were infused into a peripheral vein. The laboratory test results and long-term clinical course including liver transplantation (LT), development of cancer, cause of death, and survival after ABMI were analyzed. Nineteen patients were followed up for a median of 66 months after ABMI. Liver function, including serum levels of albumin and Child–Pugh (CP) score, was improved at the 1-year follow-up. Liver volume was significantly greater, cirrhosis was sustained, and collagen content was decreased at the 6-month follow-up. Five years after ABMI, five patients (26.3%) maintained CP class A without LT or death, and five patients (26.3%) had undergone elective LT. Hepatocellular carcinoma (HCC) occurred in five patients (26.3%), and lymphoma and colon cancer occurred in one patient each. Three patients (15.8%) were lost to follow-up at months 22, 31, and 33, respectively, but maintained CP class A until their last follow-up. Five patients expired due to infection. While improved liver function was maintained in some patients for more than 5 years after ABMI, other patients developed HCC. Further studies of long-term follow-up cohorts after cell therapy for LC are warranted.
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- 2017
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10. The Flavonoid Glabridin Induces OCT4 to Enhance Osteogenetic Potential in Mesenchymal Stem Cells
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June Seok Heo, Seung Gwan Lee, and Hyun Ok Kim
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Internal medicine ,RC31-1245 - Abstract
Mesenchymal stem cells (MSCs) are a promising tool for studying intractable diseases. Unfortunately, MSCs can easily undergo cellular senescence during in vitro expansion by losing stemness. The aim of this study was to improve the stemness and differentiation of MSCs by using glabridin, a natural flavonoid. Assessments of cell viability, cell proliferation, β-galactosidase activity, differentiation, and gene expression by reverse transcription PCR were subsequently performed in the absence or presence of glabridin. Glabridin enhanced the self-renewal capacity of MSCs, as indicated by the upregulation of the OCT4 gene. In addition, it resulted in an increase in the osteogenic differentiation potential by inducing the expression of osteogenesis-related genes such as DLX5 and RUNX2. We confirmed that glabridin improved the osteogenesis of MSCs with a significant elevation in the expression of OSTEOCALCIN and OSTEOPONTIN genes. Taken together, these results suggest that glabridin enhances osteogenic differentiation of MSCs with induction of the OCT4 gene; thus, glabridin could be useful for stem cell-based therapies.
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- 2017
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11. Development and Characterization of Tissue Equivalent Proportional Counter for Radiation Monitoring in International Space Station
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Uk-Won Nam, Chang Hwy Lim, Jae Jin Lee, Jeonghyun Pyo, Bong-Kon Moon, Dae-Hee Lee, Youngsik Park, Hyun Ok Kim, Myungkook Moon, and Sunghwan Kim
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tissue equivalent proportional counter ,linear energy transfer ,international space station ,Astronomy ,QB1-991 - Abstract
Tissue equivalent proportional counter (TEPC) can measure the Linear Energy Transfer (LET) spectrum and calculate the equivalent dose for the complicated radiation field in space. In this paper, we developed and characterized a TEPC for radiation monitoring in International Space Station (ISS). The prototype TEPC which can simulate a 2 μm of the site diameter for micro-dosimetry has been tested with a standard alpha source (241Am, 5.5 MeV). Also, the calibration of the TEPC was performed by the 252Cf neutron standard source in Korea Research Institute of Standards and Science (KRISS). The determined calibration factor was kf = 3.59×10-7 mSv/R.
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- 2013
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12. Multi-Temporal Spectral Analysis of Rice Fields in South Korea Using MODIS and RapidEye Satellite Imagery
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Hyun Ok Kim and Jong Min Yeom
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moderate resolution imaging spectroradiometer ,RapidEye ,spectral characteristics ,vegetation index ,bidirectional reflectance distribution function ,rice field ,Astronomy ,QB1-991 - Abstract
Space-borne remote sensing is an effective and inexpensive way to identify crop fields and detect the crop condition. We examined the multi-temporal spectral characteristics of rice fields in South Korea to detect their phenological development and condition. These rice fields are compact, small-scale parcels of land. For the analysis, moderate resolution imaging spectroradiometer (MODIS) and RapidEye images acquired in 2011 were used. The annual spectral tendencies of different crop types could be detected using MODIS data because of its high temporal resolution, despite its relatively low spatial resolution. A comparison between MODIS and RapidEye showed that the spectral characteristics changed with the spatial resolution. The vegetation index (VI) derived from MODIS revealed more moderate values among different land-cover types than the index derived from RapidEye. Additionally, an analysis of various VIs using RapidEye satellite data showed that the VI adopting the red edge band reflected crop conditions better than the traditionally used normalized difference VI.
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- 2012
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13. Correction: Effects of Mesenchymal Stem Cell Treatment on the Expression of Matrix Metalloproteinases and Angiogenesis during Ischemic Stroke Recovery.
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Hyo Suk Nam, Il Kwon, Bo Hyung Lee, Haejin Kim, Jayoung Kim, Sunho An, Ok-Hee Lee, Phil Hyu Lee, Hyun Ok Kim, Hyun Namgoong, Young Dae Kim, and Ji Hoe Heo
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Medicine ,Science - Published
- 2016
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14. Effects of Mesenchymal Stem Cell Treatment on the Expression of Matrix Metalloproteinases and Angiogenesis during Ischemic Stroke Recovery.
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Hyo Suk Nam, Il Kwon, Bo Hyung Lee, Haejin Kim, Jayoung Kim, Sunho An, Ok-Hee Lee, Phil Hyu Lee, Hyun Ok Kim, Hyun Namgoong, Young Dae Kim, and Ji Hoe Heo
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Medicine ,Science - Abstract
The efficacy of mesenchymal stem cell (MSC) transplantation in ischemic stroke might depend on the timing of administration. We investigated the optimal time point of MSC transplantation. After MSC treatment, we also investigated the expression of matrix metalloproteinases (MMPs), which play a role in vascular and tissue remodeling.Human bone marrow-derived MSCs (2 × 10(6), passage 5) were administrated intravenously after permanent middle cerebral artery occlusion (MCAO) was induced in male Sprague-Dawley rats. First, we determined the time point of MSC transplantation that led to maximal neurological recovery at 1 h, 1 day, and 3 days after MCAO. Next, we measured activity of MMP-2 and MMP-9, neurological recovery, infarction volume, and vascular density after transplanting MSCs at the time that led to maximal neurological recovery.Among the MSC-transplanted rats, those of the MSC 1-hour group showed maximal recovery in the rotarod test (P = 0.023) and the Longa score (P = 0.018). MMP-2 activity at 1 day after MCAO in the MSC 1-hour group was significantly higher than that in the control group (P = 0.002), but MMP-9 activity was not distinct. The MSC 1-hour group also showed smaller infarction volume and higher vascular density than did the control group.In a permanent model of rodent MCAO, very early transplantation of human MSCs (1 h after MCAO) produced greater neurological recovery and decreased infraction volume. The elevation of MMP-2 activity and the increase in vascular density after MSC treatment suggest that MSCs might help promote angiogenesis and lead to neurological improvement during the recovery phase after ischemic stroke.
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- 2015
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15. Mapping of Vegetation Using Multi-Temporal Downscaled Satellite Images of a Reclaimed Area in Saemangeum, Republic of Korea
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Mu-Sup Beon, Ki Hwan Cho, Hyun Ok Kim, Hyun-Kyung Oh, and Jong-Chul Jeong
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vegetation classification ,random forest ,downscaling ,multi-temporal image ,cokriging ,Saemangeum ,Science - Abstract
The aim of this study is to adapt and evaluate the effectiveness of a multi-temporal downscaled images technique for classifying the typical vegetation types of a reclaimed area. The areas reclaimed from estuarine tidal flats show high spatial heterogeneity in soil salinity conditions. There are three typical vegetation types for which the distribution is restricted by the soil conditions. A halophyte-dominated vegetation is located in a high saline area, grass vegetation is found in a mid- or low saline area, and reed/small-reed vegetation is situated in a low saline area. Multi-temporal satellite images were used to classify the vegetation types. Landsat images were downscaled to take into account spatial heterogeneity using cokriging. A random forest classifier was used for the classification, with downscaled Landsat and RapidEye images. Classification with RapidEye images alone demonstrated a lower level of accuracy than when combined with multi-temporal downscaled images. The results demonstrate the usefulness of a downscaling technique for mapping. This approach can provide a framework which is able to maintain low costs whilst producing richer images for the monitoring of a large and heterogeneous ecosystem.
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- 2017
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16. High Resolution Land Application Approach Using Micosatellite Costellation(NEONSAT) in Korea.
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Hyun-Ok Kim, Jong-Sung Ha, Seungtaek Jeong, Yeji Kim, Sumin Park, and Han Oh
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- 2024
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17. HER2 expression in fine needle aspirates of lymph nodes detected by preoperative axillary ultrasound in breast cancer patients.
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Ji Soo Choi, Hyun Ok Kim, Eun-Kyung Kim, Young Joo Suh, Jung Hyun Yoon, Hee Jung Moon, and Min Jung Kim
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Medicine ,Science - Abstract
The purpose of this study was to assess the usefulness of HER2 levels in ultrasonographically guided fine-needle aspiration biopsy (US-FNA) aspirates of axillary lymph nodes (ALNs) in the determination of lymph node metastasis or the characterization of primary breast cancer, and to correlate the HER2 levels in US-FNA aspirates (FNA-HER2s) of metastatic ALNs with the HER2 statuses of corresponding primary breast cancers. An institutional review board approved the study. Between January and October 2010, 164 patients with 167 ALNs examined by US-FNA were included. FNA-HER2s of ALNs were measured by chemiluminescence immunoassay, and they were correlated with cytologic/final diagnoses. Receiver operating characteristics (ROC) curve analysis was performed to evaluate the diagnostic ability to differentiate benign and metastatic ALNs. Additionally, FNA-HER2s of metastatic ALNs were correlated with HER2 status and other clinicopathologic variables of the primary breast cancers. Among the 167 ALNs, 138 were metastatic and 29 were benign. The mean FNA-HER2 (6.3 ng/ml) of metastatic ALNs was higher than that of benign ALNs. All 29 benign ALNs showed no measurable value of FNA-HER2 (0.0 ng/ml). The area under the ROC curves of FNA-HER2 of ALNs was 0.679 for the diagnosis of ALN metastasis. The FNA-HER2 statuses of 108 metastatic ALNs (79.4%) were concordant with the HER2 statuses of the corresponding primary breast cancers. In a subgroup analysis of HER2-positive cancers with ALN metastasis, distant metastasis was significantly associated with FNA-HER2-negativity of metastatic ALNs (P = 0.04). Although FNA-HER2 of ALNs did not improve the diagnostic performance of FNA cytology in preoperative diagnosis of ALN metastasis of overall patients, FNA-HER2-positive metastatic ALNs were significantly associated with HER2-positivity of primary breast cancers. Additionally, FNA-HER2 analysis of ALN may help to develop more personalized treatment protocol for breast cancer patients by determining the concordance or discordance of HER2 status between primary cancers and metastatic ALNs.
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- 2014
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18. Environmental Enrichment Synergistically Improves Functional Recovery by Transplanted Adipose Stem Cells in Chronic Hypoxic-Ischemic Brain Injury
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Jung Hwa Seo, Hyongbum Kim, Eun Sook Park, Jong Eun Lee, Dong Wook Kim, Hyun Ok Kim, Sang Hee Im, Ji Hea Yu, Ji Yeon Kim, Min-Young Lee, Chul Hoon Kim, and Sung-Rae Cho Ph.D.
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Medicine - Abstract
We investigated the effects of environmental enrichment (EE) on the function of transplanted adipose stem cells (ASCs) and the combined effect of EE and ASC transplantation on neurobehavioral function in an animal model of chronic hypoxic-ischemic (HI) brain injury. HI brain damage was induced in 7-day-old mice by unilateral carotid artery ligation and exposure to hypoxia (8% O 2 for 90 min). At 6 weeks of age, the mice were randomly injected with either ASCs or PBS into the striatum and were randomly assigned to either EE or standard cages (SC), comprising ASC-EE ( n = 18), ASC-SC ( n = 19), PBS-EE ( n = 12), PBS-SC ( n = 17), and untreated controls ( n = 23). Rotarod, forelimb-use asymmetry, and grip strength tests were performed to evaluate neurobehavioral function. The fate of transplanted cells and the levels of endogenous neurogenesis, astrocyte activation, and paracrine factors were also measured. As a result, EE and ASC transplantation synergistically improved rotarod latency, forelimb-use asymmetry, and grip strength compared to those of the other groups. The number of engrafted ASCs and βIII-tubulin + neurons derived from the transplanted ASCs was significantly higher in mice in EE than those in SC. EE and ASC transplantation also synergistically increased BrdU + βIII-tubulin + neurons, GFAP + astrocytic density, and fibroblast growth factor 2 (FGF2) level but not the level of CS-56 + glial scarring in the striatum. In conclusion, EE and ASC transplantation synergistically improved neurobehavioral functions. The underlying mechanisms of this synergism included enhanced repair processes such as higher engraftment of the transplanted ASCs, increased endogenous neurogenesis and astrocytic activation coupled with upregulation of FGF2.
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- 2013
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19. Mesenchymal Stem Cells Augment Neurogenesis in the Subventricular Zone and Enhance Differentiation of Neural Precursor Cells into Dopaminergic Neurons in the Substantia Nigra of a Parkinsonian Model
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Hyun-Jung Park, Jin Young Shin, Bo Ra Lee M.D., Ph.D., Hyun Ok Kim, and Phil Hyu Lee
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Medicine - Abstract
Growing evidence has demonstrated that neurogenesis in the subventricular zone (SVZ) is significantly decreased in Parkinson's disease (PD). Modulation of endogenous neurogenesis would have a significant impact on future therapeutic strategies for neurodegenerative diseases. In the present study, we investigated the augmentative effects of human mesenchymal stem cells (hMSCs) on neurogenesis in a PD model. Neurogenesis was assessed in vitro with 1-methyl-4-phenylpyridinium (MPP + ) treatment using neural precursor cells (NPCs) isolated from the SVZ and in vivo with a BrdU-injected animal model of PD using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Immunochemical analyses were used to measure neurogenic activity. The number of BrdU-ir cells in the SVZ and the substantia nigra (SN) was significantly increased in the hMSC-treated PD group compared with the MPTP-only-treated group. Double-stained cells for BrdU and tyrosine hydroxylase were notably observed in the SN of hMSC-treated PD animals, and they did not colocalize with the nuclear matrix; however, double-stained cells were not detected in the SN of the MPTP-induced PD animal model. Furthermore, hMSC administration increased the expression of the epidermal growth factor receptor (EGFR) in the SVZ of PD animals, and the coculture of hMSCs significantly increased the release of EGF in the medium of MPP + -treated NPCs. The present study demonstrated that hMSC administration significantly augmented neurogenesis in both the SVZ and SN of PD animal models, which led to increased differentiation of NPCs into dopaminergic neurons in the SN. Additionally, hMSC-induced modulation of EGF seems to be an underlying contributor to the enhancement of neurogenesis by hMSCs. The modulation of endogenous adult neurogenesis to repair the damaged PD brain using hMSCs would have a significant impact on future strategies for PD treatment.
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- 2012
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20. Neuroprotective Effect of Human Mesenchymal Stem Cells in an Animal Model of Double Toxin-Induced Multiple System Atrophy Parkinsonism
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Hyun-Jung Park, Giyoon Bang, Bo Ra Lee, Hyun Ok Kim, and Phil Hyu Lee M.D., Ph.D.
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Medicine - Abstract
Multiple system atrophy (MSA) is an adult-onset sporadic neurodegenerative disorder of unknown etiology featuring parkinsonism, ataxia, and autonomic failure in any combination. Because disease progression in MSA is rapid and no drug treatment consistently benefits MSA patients in the long term, neuroprotective or regenerative strategies may be invaluable in the management of MSA patients. In this study, we investigated whether human mesenchymal stem cells (hMSCs) had a protective effect on MSA using an animal model of double-toxin-induced MSA parkinsonism (MSA-P). MSA-P was established with coinjections of MPTP and 3-NP; hMSCs were injected into the tail vein 1 day after the last toxin injection. Three groups of mice were compared (i.e., control, MPTP + 3-NP, and MPTP + 3-NP with hMSC treatment) through histopathological, behavioral, and Western blot analyses. In the substantia nigra (SN) and the striatum, 2.0% and 3.8% of total injected hMSCs were observed, respectively. Compared with double-toxin-treated mice, hMSC treatment in double-toxin-treated mice significantly increased survival of TH- and NeuN-immunoreactive cells in the SN and the striatum, with coincident improvement in motor behavior. Additionally, hMSC treatment significantly decreased double-toxin-induced microglial and astroglial activation in the SN and striatum. Western blot analysis showed that hMSC administration in double-toxin-treated mice increased the expression of p-Akt and Bcl-2 and decreased Bax and cytochrome c expression. This study demonstrates that hMSC treatment protected against loss of neurons in the SN and the striatum induced by double toxin exposure, which may be mediated by modulation of inflammatory and cell survival and death signaling-pathway as the hMSCs migrated from the peripheral circulation into the SN and striatum.
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- 2011
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21. Comparison of endothelial progenitor cells in Parkinson's disease patients treated with levodopa and levodopa/COMT inhibitor.
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Phil Hyu Lee, Han-Soo Kim, Ji E Lee, Youjeong Choi, Jin Yong Hong, Hyo Suk Nam, Young H Sohn, and Hyun Ok Kim
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Medicine ,Science - Abstract
BACKGROUND: Levodopa treatment in Parkinson's disease (PD) increases in serum homocysteine levels due to its metabolism via catechol O-methyltransferase. Endothelial progenitor cells (EPCs) have the capacity to differentiate into mature endothelial cells and are markers for endothelial functions and cardiovascular risks. Along with traditional vascular risk factors, hyperhomocysteinemia is known to decrease the level of EPCs. In the present study, we hypothesized that that levodopa-induced hyperhomocysteinemia leads to a change in EPC levels. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively enrolled PD patients who had been prescribed either levodopa/carbidopa (PD-L group, n = 28) or levodopa/carbidopa/COMT inhibitor (PD-LC group, n = 25) for more than 1 year. The number of circulating EPCs was measured by flow cytometry using dual staining of anti-CD34 and anti-KDR antibodies. The EPCs were divided into tertiles based on their distributions and a logistic regression analysis was used to estimate independent predictors of the highest tertile of EPCs. The number of endothelial progenitor cells was significantly decreased in PD-L patients (118±99/mL) compared with either PD-LC patients (269±258/mL, p = 0.007) or controls (206±204/mL, p = 0.012). The level of homocysteine was significantly increased in PD-L patients (14.9±5.3 µmol/L) compared with either PD-LC patients (11.9±3.0 µmol/L, p = 0.028) or controls (11.1±2.5 µmol/L, p = 0.012). The level of homocysteine was negatively correlated with endothelial progenitor cell levels (r = -0.252, p = 0.028) and was an independent predictor of the highest tertile of endothelial progenitor cell levels (OR; 0.749 [95% CI: 0.584-0.961]). CONCLUSIONS/SIGNIFICANCE: These data indicate that a higher consumption of EPC for restoration of endothelial damage may be associated with chronic levodopa treatment in PD patients.
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- 2011
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22. Autologous Bone Marrow Infusion Activates the Progenitor Cell Compartment in Patients with Advanced Liver Cirrhosis
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Ja Kyung Kim, Young Nyun Park, Jin Seok Kim, Mi-Suk Park, Yong Han Paik, Jae-Yeon Seok, Yong Eun Chung, Hyun Ok Kim, Kyung Sik Kim, Sang Hoon Ahn, Do Young Kim, Myeong-Jin Kim, Kwan Sik Lee, Chae Yoon Chon, Soo Jeong Kim, Shuji Terai, Isao Sakaida, and Kwang-Hyub Han
- Subjects
Medicine - Abstract
Several clinical trials of bone marrow cell infusion in patients with liver cirrhosis (LC) have shown clinical improvement, despite conflicting results from animal models. We investigated serial pathological features and the clinical impact after autologous bone marrow infusion (ABMI) in patients with advanced LC. Ten patients with advanced LC due to chronic hepatitis B virus infection underwent ABMI. Serological tests, MRI, and liver biopsies were performed, and quality of life was assessed by a questionnaire. Median serum albumin and hemoglobin levels increased significantly after ABMI. All patients showed an improvement in quality of life, with no serious adverse events. Liver volume, measured by MRI, increased in 80% of the patients, and ascites decreased after ABMI. Child-Pugh scores were also significantly improved at 6 months after ABMI. In the serially biopsied livers, a gradually increasing activation of the hepatic progenitor cell (HPC) compartment, including HPC activation (ductular reaction) and HPC differentiation (intermediate hepatocyte), reached a peak after 3 months, with continued proliferation of hepatocytes, and returned to baseline levels after 6 months. There was no significant change in grade or stage of liver fibrosis or stellate cell activation after ABMI. ABMI is suggested to improve liver function and to activate the progenitor cell compartment. Although clinical improvement was sustained for more than 6 months, histological changes in the liver returned to baseline 6 months after ABMI. Further comparative studies are warranted.
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- 2010
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23. A Study On Thresholding Methods Of Damaged Area Detection By Wildfires For Newly Launching Microsatellites.
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Yeji Kim, Ahram Song, Hongtak Lee, Hyun Ok Kim, and Sun Gu Lee
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- 2023
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24. An Overview of the Initiatives and Activities of the Korean Blood Safety Project Group over a Ten Year Period: 2012∼2021
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Young Ae Lim and Hyun Ok Kim
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General Medicine - Published
- 2023
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25. Data Mining for Classificational Prediction of Poly-victim Children by School Adaptation Factors and Local Spatial Factors
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Ji Hyun Jang, Hyun Ok Kim, and Soo Young Kim
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General Earth and Planetary Sciences ,General Environmental Science - Published
- 2023
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26. A Case Report of Passenger Lymphocyte Syndrome Following Bidirectional ABO-mismatched Kidney Transplantation
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Jiyeon Kim, Junhyup Song, Soon Sung Kwon, Sinyoung Kim, Kyu Ha Huh, and Hyun Ok Kim
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- 2022
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27. Incidence and characteristics of hypotensive transfusion reaction: 10‐year experience in a single center
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Soon Sung Kwon, Sinyoung Kim, and Hyun Ok Kim
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Incidence ,Immunology ,Humans ,Transfusion Reaction ,Immunology and Allergy ,Blood Transfusion ,Hematology ,Hypotension ,Retrospective Studies - Abstract
Hypotensive transfusion reaction (HyTR) is rare. It is characterized by a rapid onset of hypotension during transfusion, which usually resolves quickly upon cessation of transfusion. Information on the incidence and clinical characteristics of HyTR has been reported in only a few studies.We retrospectively reviewed HyTR cases from 10-year hemovigilance data in a tertiary care hospital in Seoul, Korea.We identified 37 HyTRs in 35 patients, and the overall incidence of HyTR was 0.50 per 10,000 transfused units. Among the blood components, the incidence of HyTR was highest in filtered random donor platelets (0.75 per 10,000 units). About half of the HyTRs occurred within 15 min after the start of transfusion (19/37). Blood pressure returned to the normal range within an hour in 73.0% of the cases (27/37). All HyTR cases recovered without severe complications. Known risk factors for HyTR were not prominent in our cohort of patients, with no patients taking angiotensin-converting enzyme inhibitors and only five patients transfused with bedside filtered platelets.HyTR can occur in patients with various conditions and types of blood components. Understanding the clinical characteristics of HyTR facilitates proper management, leading to improved transfusion safety.
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- 2022
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28. Peptoniphilus gorbachii alleviates collagen-induced arthritis in mice by improving intestinal homeostasis and immune regulation.
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Suhee Kim, Sung Hak Chun, Yun-Hong Cheon, Mingyo Kim, Hyun-Ok Kim, Hanna Lee, SeongTshool Hong, Sang-Jun Park, Myeong Soo Park, Young Sun Suh, and Sang-Il Lee
- Subjects
COLLAGEN-induced arthritis ,IMMUNOGLOBULIN M ,INTESTINES ,HOMEOSTASIS ,GUT microbiome ,EXPERIMENTAL arthritis - Abstract
Introduction: The intricate connection between gut microbiota and rheumatoid arthritis (RA) pathogenesis has gained prominence, although the specific microbial species contributing to RA development remain largely unknown. Recent studies have sought to comprehensively explore alterations in the human microbiome, focusing on identifying disease-related microbial species through blood analysis. Consequently, this study aimed to identify RA-associated microbial species using a serum microbial array system and to investigate the efficacy and underlying mechanisms of potential microbial species for RA treatment. Methods: Serum immunoglobulin M levels against 384 intestinal microbial species were assessed using a microbial microarray in patients with RA and healthy individuals. We investigated the therapeutic potential of the identified microbial candidate regarding arthritis development, immune responses, gut barrier function, and gut microbiome using a collagen-induced arthritis (CIA) mouse model. Results: Our findings revealed significant alterations in antibody levels against 36 microbial species in patients with RA compared to healthy individuals. Notably, the antibody levels against Peptoniphilus gorbachii (PG) were decreased in patients with RA and exhibited an inverse correlation with RA disease activity. In vitro experiments demonstrated that PG produced acetate and butyrate, while exhibiting anti-inflammatory properties. In CIA mice, PG administration suppressed arthritis symptoms, reduced the accumulation of inflammatory monocytes in the mesenteric lymph nodes, and downregulated gene expression of pro-inflammatory cytokines in the ileum. Additionally, PG supplementation restored intestinal barrier integrity and partially resolved gut microbial dysbiosis in CIA mice. The fecal microbiota in PG-treated mice corresponded to improved intestinal barrier integrity and reduced inflammatory responses. Conclusion: This study highlights the potential of serum-based detection of anti-microbial antibodies to identify microbial targets at the species level for RA treatment. Moreover, our findings suggest that PG, identified through the microbial microarray analysis, holds therapeutic potential for RA by restoring intestinal barrier integrity and suppressing the immunologic response associated with RA. [ABSTRACT FROM AUTHOR]
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- 2024
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29. First-in-Human Phase 1 Study of a B Cell- and Monocyte-Based Immunotherapeutic Vaccine against HER2-Positive Advanced Gastric Cancer.
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Minkyu Jung, Jii Bum Lee, Hyo Song Kim, Woo Sun Kwon, Hyun Ok Kim, Sinyoung Kim, Myunghwan Park, Wuhyun Kim, Ki-Young Choi, Taegwon Oh, Chang-Yuil Kang, Hyun Cheol Chung, and Sun Young Rha
- Subjects
STOMACH cancer ,EPIDERMAL growth factor receptors ,CYTOTOXIC T cells ,KILLER cells ,CANCER patients - Abstract
Purpose BVAC-B is an autologous B cell- and monocyte-based immunotherapeutic vaccine that contains cells transfected with a recombinant human epidermal growth factor receptor 2 (HER2) gene and loaded with the natural killer T cell ligand alpha-galactosylceramide. Here, we report the first BVAC-B study in patients with HER2-positive advanced gastric cancer. Materials and Methods Patients with advanced gastric cancer refractory to standard treatment with HER2+ immunohistochemistry ≥ 1 were eligible for treatment. Patients were administered low (2.5×10
7 cells/dose), medium (5.0×107 cells/dose), or high dose (1.0×108 cells/dose) of BVAC-B intravenously four times every 4 weeks. Primary endpoints included safety and maximum tolerated BVAC-B dose. Secondary endpoints included preliminary clinical efficacy and BVAC-B-induced immune responses. Results Eight patients were treated with BVAC-B at low (n=1), medium (n=1), and high doses (n=6). No dose-limiting toxicity was observed, while treatment-related adverse events (TRAEs) were observed in patients treated with medium and high doses. The most common TRAEs were grade 1 (n=2) and grade 2 (n=2) fever. Out of the six patients treated with high-dose BVAC-B, three had stable disease with no response. Interferon gamma, tumor necrosis factor-α, and interleukin-6 increased after BVAC-B treatment in all patients with medium and high dose, and HER2-specific antibody was detected in some patients. Conclusion BVAC-B monotherapy had a safe toxicity profile with limited clinical activity; however, it activated immune cells in heavily pretreated patients with HER2-positive gastric cancer. Earlier treatment with BVAC-B and combination therapy is warranted for evaluation of clinical efficacy. [ABSTRACT FROM AUTHOR]- Published
- 2024
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30. Branch Path Analysis of Intrinsic and Extrinsic Family Factors for Mixed Distribution of Adolescent Physical Health - GMM and Decision Tree Model Center
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So-Hyeong Kim, Hyun-Ok Kim, and Kyoung-Ho Kim
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- 2022
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31. A Study on Adolescents’ Experience on the Potential Mixed Unjust Damage by Using CARET and GMM -Focusing on human rights and participatory activities
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Hae Seon Park and Hyun Ok Kim
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General Medicine - Published
- 2022
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32. Critical study about social disrecognition of perpetrator and victims of mass killing : Focusing on the analysis of unstructured big data on media reports of the mass killing in Jinju public apartment
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Hyun-Ok Kim
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- 2022
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33. A Study on the Differences and Decision Tree of Children’s Emotional Behavior according to the Mixed Spatial Types
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Hyun Ok Kim, Ji Hyun Jang, and Sooyoung Kim
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- 2022
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34. Decision Tree Model for Educational Services Predicting Children’s Academic Performance by Income Group
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Hae Seon Park, Hye Kyung Lim, and Hyun Ok Kim
- Abstract
Background and objective This study used the decision tree analysis among data mining techniques to determine whether children’s academic performance can be classified and predicted by income group based on factors of educational services. Methods For empirical analysis, data from the 10th Panel Study on Korean Children collected in 2017 was utilized. A F test was conducted to analyze the differences in variables by income group, and a decision tree analysis was conducted on the cost and time of private education services utilized by children to predict their academic performance by income group. Results First, as a result of analyzing the research variables by income group, there was a significant difference in institute time, community center time, institute cost, lesson cost, after-school cost, and culture center cost. Second, as a result of the decision tree analysis that predicts children’s academic performance by income group, it was found that for children in the low-income group, institute cost, institute time, visiting cost, and after-school time were important variables that predict their academic performance. For children in the middle-income group, institute cost, after-school time, and after-school cost were important variables for predicting academic performance. For children in the high-income group, the important variables were institute time, institute cost, after-school time, and after-school cost. Conclusion There was no significant difference in children’s academic performance in the earlier grades of elementary school, but there was a significant difference in the private education service they utilized, which may affect future income gaps as well as education gaps. This suggested the need to diversify and improve the quality of public education services as a countermeasure for the fact that parental income will cause an academic gap among children through private education.
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- 2022
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35. Inspection and Evaluation of Blood Cold Chain
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Yi Gyung Kim, Na Mi Kim, Choong Hoon Jang, Hyun Ok Kim, and Jun Nyun Kim
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- 2022
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36. Predicting the Classification of Psychosocial Factors of Children of Transnational Migrants According to the Type of Mixed Distribution Cluster of Multicultural Characteristics - Analysis of Mixed Distribution Cluster and CARET
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Hae soon Kang, Hyun Ok Kim, and So Hyeong Kim
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- 2022
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37. A Case of Palisaded Neutrophilic and Granulomatous Dermatitis Associated with an Initial Presentation in Ankylosing Spondylitis
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Young Sun Suh, Eui Chang Jung, Yun Sun Moon, Seung-Geun Lee, and Hyun-Ok Kim
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Dermatology - Published
- 2023
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38. Semantic Network Analysis on the Study of Poverty of Children and Adolescents in Korea
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Yu Kyung Seo and Hyun Ok Kim
- Subjects
General Medicine - Published
- 2021
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39. Comparison of Machine Learning Analysis on Predictive Factors of Children’s Planning-Organizing Executive Function by Income Level: Through Home Environment Quality and Wealth Factors
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Hye-Kyung Lim, Hyun-Ok Kim, and Hae-Seon Park
- Abstract
Background and objective This study identifies whether children’s planning-organizing executive function can be significantly classified and predicted by home environment quality and wealth factors. Methods For empirical analysis, we used the data collected from the 10th Panel Study on Korean Children in 2017. Using machine learning tools such as support vector machine (SVM) and random forest (RF), we evaluated the accuracy of the model in which home environment factors classify and predict children’s planning-organizing executive functions, and extract the relative importance of variables that determine these executive functions by income group. Results First, SVM analysis shows that home environment quality and wealth factors show high accuracy in classification and prediction in all three groups. Second, RF analysis shows that estate had the highest predictive power in the high-income group, followed by income, asset, learning, reinforcement, and emotional environment. In the middle-income group, emotional environment showed the highest score, followed by estate, asset, reinforcement, and income. In the low-income group, estate showed the highest score, followed by income, asset, learning, reinforcement, and emotional environment. Conclusion This study confirmed that home environment quality and wealth factors are significant factors in predicting children’s planning-organizing executive functions.
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- 2021
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40. Application of GOCI-derived vegetation index profiles to estimation of paddy rice yield using the GRAMI rice model.
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Jong-Min Yeom, Jonghan Ko, and Hyun-Ok Kim
- Published
- 2015
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41. Comparison of NDVIs from GOCI and MODIS Data towards Improved Assessment of Crop Temporal Dynamics in the Case of Paddy Rice.
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Jong-Min Yeom and Hyun-Ok Kim
- Published
- 2015
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42. Evaluation of Polarimetric SAR Decomposition for Classifying Wetland Vegetation Types.
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Sang-Hoon Hong, Hyun-Ok Kim, Shimon Wdowinski, and Emanuelle Feliciano
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- 2015
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43. Rapid Analysis of Bacterial Contamination in Platelets without Pre-Enrichment Using Pig Serum-Derived Antibodies
- Author
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Ga Yeon Lee, Jae Chul Pyun, Hyun Ok Kim, Jeong Soo Sung, Min Jung Kang, Ji Hong Bong, Jun Hee Park, and Chang Kyu Lee
- Subjects
Blood Platelets ,Immunoassay ,biology ,Swine ,Chemistry ,Biochemistry (medical) ,Biomedical Engineering ,Membrane Proteins ,Biosensing Techniques ,General Chemistry ,Contamination ,Gram-Positive Bacteria ,Shelf life ,Antibodies ,Microbiology ,Biomaterials ,Pre enrichment ,Gram-Negative Bacteria ,Escherichia coli ,biology.protein ,Animals ,Platelet ,Antibody - Abstract
As the shelf life of platelets collected from donated blood is very short, approximately 5 days, the determination of bacterial contamination in platelets has become necessary. In this study, rapid analysis of Gram-positive and Gram-negative bacterial contamination in platelet samples was presented without pre-enrichment using pig serum-derived antibodies against the outer membrane proteins (OMP) of Gram-negative bacteria and antibodies against lipoteichoic acid (LTA) on the surface of Gram-positive bacteria. The anti-OMP antibodies against Gram-negative bacteria were isolated using sequential incubation with (1) the modified Gram-negative bacteria ClearColi, which lacks lipopolysaccharide (LPS) on the outer membrane, and (2) the Gram-positive bacteria
- Published
- 2021
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44. Early neuro-prognostication with the Patient State Index and suppression ratio in post-cardiac arrest patients
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Woo Jin Jung, Hyun Ok Kim, Tae Youn Kim, Soyeong Kim, Young Il Roh, Kyoung-Chul Cha, and Sung Oh Hwang
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Adult ,medicine.medical_treatment ,Sedation ,Neurological examination ,Targeted temperature management ,Return of spontaneous circulation ,Critical Care and Intensive Care Medicine ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Hypothermia, Induced ,law ,medicine ,Humans ,Cardiopulmonary resuscitation ,medicine.diagnostic_test ,business.industry ,Mortality rate ,Electroencephalography ,030208 emergency & critical care medicine ,Prognosis ,Intensive care unit ,Cardiopulmonary Resuscitation ,Confidence interval ,030228 respiratory system ,Anesthesia ,medicine.symptom ,business ,Out-of-Hospital Cardiac Arrest - Abstract
Purpose Cardiopulmonary resuscitation guidelines recommend multimodal neuro-prognostication after cardiac arrest using neurological examination, electroencephalography, biomarkers, and brain imaging. The Patient State Index (PSI) and suppression ratio (SR) represent the depth and degree of sedation, respectively. We evaluated the predictive ability of PSI and SR for neuro-prognostication of post-cardiac arrest patients who underwent targeted temperature management. Methods This prospective observational study was conducted between January 2017 and August 2020 and enrolled adult patients in an intensive care unit (ICU) with non-traumatic out-of-hospital cardiac arrest with return of spontaneous circulation (ROSC). PSI and SR were monitored continuously during ICU stay, and their maximum, mean, and minimum cutoff values 24 h after ROSC were analyzed to predict poor neurologic outcome and long-term survival. Results The final analysis included 103 patients. A mean PSI ≤ 14.53 and mean SR > 36.6 showed high diagnostic accuracy as single prognostic factors. Multimodal prediction using the mean PSI and mean SR showed the highest area-under-the-curve value of 0.965 (95% confidence interval 0.909–0.991). Patients with mean PSI ≤ 14.53 and mean SR > 36.6 had relatively higher long-term mortality rates than those of patients with values >14.53 and ≤ 36.6, respectively. Conclusions The PSI and SR are good predictors for early neuro-prognostication in post-cardiac arrest patients.
- Published
- 2021
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45. Comparison of the decision tree model on smartphone dependence between the polar income adolescents
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Hyun Ok Kim and Yu Kyung Seo
- Subjects
Statistics ,Polar ,General Medicine ,Decision tree model ,Mathematics - Published
- 2021
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46. Human endometrium derived induced pluripotent stem cells are amenable to directed erythroid differentiation
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Hyun Kyung Kim, Si Hyun Cho, Young Sik Choi, Byung Seok Lee, Sinyoung Kim, Hyun Ok Kim, and Joo Hyun Park
- Abstract
Background: With the consistent increase in life-expectancy, excavating novel sources of regenerative medicine is an important objective to enhance disease free life expectancy. A comprehensive protocol for using human endometrium derived induced pluripotent stem cells to derive hematopoietic and erythroid lineages will be elaborated, through a two-phase culture system. Method: Discarded endometrial tissues were obtained from women receiving hysterectomy in their 4th to 5th decade due to benign uterine conditions. The endometrial cells isolated were expanded to passage 3-4 to allow stromal cells to dominate in the culture environment. pCE-Sox2, Oct4, Klf4, L-Myc and Lin28 episomal vectors were used to electrotransfection the endometrial stromal cells. The erythroblast differentiation of these established induced pluripotent stem cells (iPSCs) were conducted in two phases. The first 8 days involves commitment to hematopoietic stem cells through embryoid body with robust expansion on murine bone marrow stromal cells. The second phase involves feeder free conditions with hydrocortisone, stem cell factor, interleukin-3, and recombinant EPO. After 22 days of feeder free culture, the expression profiles of CD235a+, CD34+, CD43+ and CD 71+ were analyzed by flow cytometry and Wright-Giemsa staining for differential counting. The oxygen carrying capacity of cultured RBCs was measured using a hemoxanalyser. Results: As a result of inducing these cells via co-culture with murine stromal fibroblasts, all endometrium derived iPSCs were differentiated into erythroblasts with stably yielding over 80% of polychromatic and orthochromatic normoblast. The protocol for complete induction of erythroid lineage cells starting from human endometrial tissue via iPS cells has been optimized. Conclusion: Successful induction of hematopoietic cell fate followed by erythroid differentiation up to erythroblast were achieved in an effort to develop transfusion source. And a complete process of actually deriving iPS cells with discarded surgical hysterectomy specimens has significance in the possibility of expanding the scope of use of theses iPSC cell lines in the future.
- Published
- 2022
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47. Isolation of Antibodies Against the Spike Protein of SARS-CoV from Pig Serum for Competitive Immunoassay
- Author
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Jae Chul Pyun, Hyun Ok Kim, Tae Hun Kim, Jeong Soo Sung, Chang Kyu Lee, Ji-Hong Bong, Min Jung Kang, Hyun-Jin Shin, and Jaeyong Jung
- Subjects
HBsAg ,viruses ,Biomedical Engineering ,Bioengineering ,medicine.disease_cause ,Virus ,Antigen ,Influenza A virus ,medicine ,Electrical and Electronic Engineering ,Bovine serum albumin ,biology ,medicine.diagnostic_test ,Viral culture ,Chemistry ,fungi ,virus diseases ,SARS-CoV spike protein ,Virology ,respiratory tract diseases ,Pig serum ,Immunoassay ,biology.protein ,Competitive immunoassay ,Original Article ,Antibody ,Antibody isolation ,Biotechnology - Abstract
Several endemic corona viruses (eCoVs) have been reported to be the most common etiologic agents for the seasonal common cold and also cause pneumonia. These eCoVs share extensive sequence homology with SARS-CoV-2, and immune responses to eCoVs can cross-react with SARS-CoV-2 antigens. Based on such cross-reactivity of antigens among eCoVs, the IgG antibodies against the spike protein (SP) of severe acute respiratory syndrome coronavirus (SARS-CoV) were isolated from pig serum using magnetic beads immobilized with SARS-CoV SP and a protein-A column. The selectivity of the isolated antibodies was tested using different types of antigens, such as SARS-CoV-2 nucleoprotein (NP), influenza A virus (Beijing type), influenza B virus (Tokio and Florida types), human hepatitis B virus surface antigen (HBsAg), and bovine serum albumin (BSA). From the selectivity test, the anti-SP antibodies isolated from pig serum had sufficient selectivity to other kinds of viral antigens, and the apparent binding constant of the isolated antibodies was approximately 1.5 × 10–8 M from the surface plasmon resonance (SPR) measurements. Finally, the isolated anti-SP antibodies were applied to the immunoassay of SP using competitive immunoassay configuration. The feasibility of the detection as well as the quantitative analysis of the SARS-CoV viral culture fluid was determined using four viral culture samples, namely, SARS-CoV, SARS-CoV-2, MERS-CoV, and CoV-229E.
- Published
- 2021
48. Major component causing neurological toxicity in acute glufosinate ammonium poisoning: determination of glufosinate, 1-methoxy-2-propanol, and ammonia in serum and cerebrospinal fluid
- Author
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Sung Hwa Kim, Seonghoon Yeon, Yong Sung Cha, Hyun Ok Kim, Yoonsuk Lee, Juhyun Sim, and Sunchun Kim
- Subjects
Chromatography ,integumentary system ,Herbicides ,Aminobutyrates ,Toxic encephalopathy ,Neurotoxicity ,nutritional and metabolic diseases ,General Medicine ,Toxicology ,medicine.disease ,Propanol ,chemistry.chemical_compound ,Ammonia ,Cerebrospinal fluid ,chemistry ,Glufosinate ,Propylene Glycols ,Seizures ,Toxicity ,medicine ,Glufosinate-ammonium ,Humans - Abstract
To determine the primary contributor to neurotoxicity in patients with glufosinate ammonium (GLA) poisoning, by quantifying glufosinate, 1-methoxy-2-propanol, and ammonia in serum and the cerebrospinal fluid (CSF). We collected and analysed data from confirmed cases of GLA poisoning between May 2018 and August 2020. Based on the occurrence of neurological complications (mental change, seizure, and central apnoea), patients were assigned to one of two groups: those with complications (NCx) and without (non-NCx) complications. Concentrations of glufosinate, 1-methoxy-2-propanol (1M2P), and ammonia were measured in the serum upon admission and during hospital stay. The concentrations of all these substances were again measured in the CSF following a decline in the mental status or seizure (NCx group) or on the day after hospitalisation (non-NCx group). Of the 20 patients included, ammonia levels in the serum and CSF at onset of altered sensorium in the NCx group (n = 16) were significantly higher than those at one day after hospitalisation in the non-NCx group (n = 4) (p = 0.011 in serum, p = 0.047 in CSF), with its concentration in the CSF being higher than that in the serum in 15/16 cases. The concentration of 1M2P was similar in the serum and CSF (8/16), but the concentrations of glufosinate (7/16) was lower in the CSF than in the serum. In the non-NCx group (n = 4), only ammonia was detectable. Among patients with GLA poisoning, increased CSF ammonia was significantly correlated with neurological complications.
- Published
- 2021
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49. Smart Blood Bag Management System in a Hospital Environment.
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Soo-Jung Kim, Sun K. Yoo, Hyun-Ok Kim, Hasuk Bae, Jung-Jin Park, Kuk-Jin Seo, and Byung-Chul Chang
- Published
- 2006
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50. Compensation Method of Monopulse Slope Distortion within Using Sidelobe Canceler
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Hyun Ok Kim, Ki-Ho Kim, and Hyung-Suk Jin
- Subjects
Computer science ,Monopulse radar ,Distortion ,Acoustics ,Compensation (engineering) - Published
- 2021
- Full Text
- View/download PDF
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