55 results on '"Ha Na Choi"'
Search Results
2. Determination of Residual Triflumezopyrim Insecticide in Agricultural Products through a Modified QuEChERS Method
- Author
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Sung-Min Cho, Han-Sol Lee, Ji-Su Park, Su-Jung Lee, Hye-Sun Shin, Yun-Mi Chung, Ha-Na Choi, Yong-Hyun Jung, Jae-Ho Oh, and Sang-Soon Yun
- Subjects
triflumezopyrim ,pesticide residue ,food ,QuEChERS ,maximum residue limit ,Chemical technology ,TP1-1185 - Abstract
A rapid and simple analytical method for triflumezopyrim, a new class of mesoionic insecticides and commercialized molecules from DuPont, was developed with a modified QuEChERS method. The pH adjustment was used to improve the extraction efficiency of acetonitrile solvent, and dispersive solid-phase extraction was employed for the clean-up process. The five selected food commodities were used to verify the present optimized method, which displayed good linearity with an excellent correlation coefficient (R2 = 0.9992–0.9998) in the 0.003–0.30 mg/kg calibration range. The method limits of detection (LOD) and quantification (LOQ) were determined to be a value of 0.003 and 0.01 mg/kg, respectively. The mean recovery for the triflumezopyrim was in the 89.7–104.3% range. The relative standard deviations were ≤9.8% for intra- (n = 5) and inter-day (n = 15) precisions at concentrations of 0.01, 0.1, and 0.5 mg/kg in the five representative samples. The matrix effect has been calculated to confirm the effect during ionization of the analyte in the UPLC-MS/MS. The matrix effects of the instrumental analysis showed that triflumezopyrim was less susceptible to matrices. The proposed analytical method in this study has effectively improved the accuracy, selectivity, and sensitivity for the determination of triflumezopyrim in agricultural commodities; therefore, it can serve as a reference method for the establishment of maximum residue limits (MRLs).
- Published
- 2021
- Full Text
- View/download PDF
3. The role of protein phosphatase 2A (PP2A) in the unfolded protein response (UPR) of plants
- Author
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Ki Seong Ko, Jae Yong Yoo, Bich Ngoc Vu, Young Eun Lee, Ha Na Choi, Yoo Na Lee, Wahyu Indra Duwi Fanata, Rikno Harmoko, Woo Sik Chung, Jong Chan Hong, and Kyun Oh Lee
- Subjects
Biophysics ,Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2023
- Full Text
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4. A Study on Process for Metal Coloring -With Focus on Blue-Green Patina of Copper and Bronze
- Author
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Ha Na Choi and Hyun Sook Chang
- Subjects
General Medicine - Published
- 2022
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5. Supplementary Table and Figures from Characterization of CD45−/CD31+/CD105+ Circulating Cells in the Peripheral Blood of Patients with Gynecologic Malignancies
- Author
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Tae Jin Kim, Sun Jin Kim, Jang-Seong Kim, Lee S. H. Yi, Yeup Yoon, Ki-Heon Lee, Haeng-Seok Song, Ji-Young Choi, Jin-Hyung Ahn, Ha-Na Choi, Ho-Jeong Lee, and Hyun-Kyung Yu
- Abstract
Supplementary Table and Figures - PDF file 237K, Supplementary Table 1. Clinical characteristics of cancer patients. Supplementary Fig. 1. Isolation of CD45+/CD31- cells, CD45+/CD31bright cells, and CD45-/CD31+ cells from PBMCs using FACSAria flow cytometer. Supplementary Fig. 2. A Venn diagram showing the expression of various antigens in the endothelial cells, platelets, and monocytes
- Published
- 2023
- Full Text
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6. Data from Characterization of CD45−/CD31+/CD105+ Circulating Cells in the Peripheral Blood of Patients with Gynecologic Malignancies
- Author
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Tae Jin Kim, Sun Jin Kim, Jang-Seong Kim, Lee S. H. Yi, Yeup Yoon, Ki-Heon Lee, Haeng-Seok Song, Ji-Young Choi, Jin-Hyung Ahn, Ha-Na Choi, Ho-Jeong Lee, and Hyun-Kyung Yu
- Abstract
Purpose: Circulating endothelial cells (CEC) have been widely used as a prognostic biomarker and regarded as a promising strategy for monitoring the response to treatment in several cancers. However, the presence and biologic roles of CECs have remained controversial for decades because technical standards for the identification and quantification of CECs have not been established. Here, we hypothesized that CECs detected by flow cytometry might be monocytes rather than endothelial cells.Experimental Design: The frequency of representative CEC subsets (i.e., CD45−/CD31+, CD45−/CD31+/CD146+, CD45−/CD31+/CD105+) was analyzed in the peripheral blood of patients with gynecologic cancer (n = 56) and healthy volunteers (n = 44). CD45−/CD31+ cells, which are components of CECs, were isolated and the expression of various markers (CD146, CD105, vWF, and CD144 for endothelial cells; CD68 and CD14 for monocytes) was examined by immunocytochemistry.Results: CD45−/CD31+/CD105+ cells were significantly increased in the peripheral blood of patients with cancer, whereas evaluation of CD45−/CD31+/CD146+ cells was not possible both in patients with cancer and healthy controls due to the limited resolution of the flow cytometry. Immunocytochemistry analyses showed that these CD45−/CD31+/CD105+ cells did not express vWF and CD146 but rather CD144. Furthermore, CD45−/CD31+/CD105+ cells uniformly expressed the monocyte-specific markers CD14 and CD68. These results suggest that CD45−/CD31+/CD105+ cells carry the characteristics of monocytes rather than endothelial cells.Conclusions: Our data indicate that CD45−/CD31+/CD105+ circulating cells, which are significantly increased in the peripheral blood of patients with gynecologic cancer, are monocytes rather than endothelial cells. Further investigation is required to determine the biologic significance of their presence and function in relation with angiogenesis. Clin Cancer Res; 19(19); 5340–50. ©2013 AACR.
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- 2023
- Full Text
- View/download PDF
7. Determination and Validation of an Analytical Method for Dichlobentiazox in Agricultural Products with LC-MS/MS
- Author
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Yun mi Chung, Hye-Sun Shin, Young-Hyun Jung, Han Sol Lee, Hae Jung Yoon, Sang Soon Yoon, Ha na Choi, Sun Young Gu, Ji-Su Park, Sung Eun Kang, and Su Jung Lee
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Chromatography ,Chemistry ,Lc ms ms ,General Medicine - Published
- 2021
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8. Factors Influencing the Oral Health Care Behaviors of Parents to Preschool Children
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Ji-Won Lee and Ha-Na Choi
- Subjects
medicine.medical_specialty ,business.industry ,Family medicine ,Oral health education ,medicine ,Oral health care ,business - Published
- 2020
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9. The Effect of Mechanical Tongue Cleaning on Oral Malodor and Tongue Coating
- Author
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Ha-Na Choi, Young-Sik Cho, and Jung-Wan Koo
- Subjects
Toothbrushing ,tongue coating ,Sulfur Compounds ,Diagnostic Tests, Routine ,Health, Toxicology and Mutagenesis ,Public Health, Environmental and Occupational Health ,mechanical tongue cleaning ,oral malodor ,toothbrush ,tongue scraper ,Halitosis ,Article ,Tongue ,Medicine ,Humans - Abstract
Background: Mechanical tongue cleaning is an important oral hygiene procedure; it is known that a significant cause of volatile sulfur compounds (VSCs), a major component of bad breath, is due to the bacteria coating the tongue. This study was conducted to identify the effect of mechanical tongue cleaning on reducing bad breath and tongue coating. Methods: Various mechanical tongue-cleaning methods were studied, including removing tongue coating using a toothbrush, removing tongue coating using a tongue scraper, and removing tongue coating using a toothbrush and a tongue scraper together. The results were as follows. Results: First, the organic bad breath measurement value after cleaning the tongue significantly decreased in the group using only the toothbrush, the group using only the tongue scraper, and the group using both the toothbrush and the tongue scraper. However, there was no difference between the groups. Second, after cleaning the tongue, the measured values of the tongue coating in the values of WTCI (Winkel’s tongue coating index) and Qray view were significantly reduced in all three groups, and there was no difference between the groups. Third, the gas measurement value in the oral cavity using a machine significantly decreased only the H2S value of the group using the tongue scraper immediately after the mechanical tongue cleaning. Conclusions: From these results, it can be confirmed that mechanical tongue cleaning is effective at reducing bad breath and tongue coating. However, in this study, there was no difference in the reduction effect according to the tools (groups) used for mechanical tongue cleaning. It can therefore be seen that wiping accurately from the rear of the tongue to the front is more effective at reducing bad breath and tongue coating.
- Published
- 2021
10. Determination of Residual Triflumezopyrim Insecticide in Agricultural Products through a Modified QuEChERS Method
- Author
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Ha-Na Choi, Han-Sol Lee, Su-Jung Lee, Sung Min Cho, Yong-hyun Jung, Hye-Sun Shin, Sang-Soon Yun, Yun-Mi Chung, Ji-Su Park, and Jae-Ho Oh
- Subjects
Detection limit ,Residue (complex analysis) ,Analyte ,QuEChERS ,Health (social science) ,Maximum Residue Limit ,Chromatography ,Correlation coefficient ,Pesticide residue ,triflumezopyrim ,Chemical technology ,food ,Extraction (chemistry) ,TP1-1185 ,Plant Science ,pesticide residue ,Quechers ,Health Professions (miscellaneous) ,Microbiology ,Article ,maximum residue limit ,Food Science ,Mathematics - Abstract
A rapid and simple analytical method for triflumezopyrim, a new class of mesoionic insecticides and commercialized molecules from DuPont, was developed with a modified QuEChERS method. The pH adjustment was used to improve the extraction efficiency of acetonitrile solvent, and dispersive solid-phase extraction was employed for the clean-up process. The five selected food commodities were used to verify the present optimized method, which displayed good linearity with an excellent correlation coefficient (R2 = 0.9992–0.9998) in the 0.003–0.30 mg/kg calibration range. The method limits of detection (LOD) and quantification (LOQ) were determined to be a value of 0.003 and 0.01 mg/kg, respectively. The mean recovery for the triflumezopyrim was in the 89.7–104.3% range. The relative standard deviations were ≤9.8% for intra- (n = 5) and inter-day (n = 15) precisions at concentrations of 0.01, 0.1, and 0.5 mg/kg in the five representative samples. The matrix effect has been calculated to confirm the effect during ionization of the analyte in the UPLC-MS/MS. The matrix effects of the instrumental analysis showed that triflumezopyrim was less susceptible to matrices. The proposed analytical method in this study has effectively improved the accuracy, selectivity, and sensitivity for the determination of triflumezopyrim in agricultural commodities, therefore, it can serve as a reference method for the establishment of maximum residue limits (MRLs).
- Published
- 2021
11. A Case Study on Parents Peer Counselor’s for the Disabled Experiences in Field Counseling
- Author
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Jong-Hwa Jeong, Eun-Jae Kim, and Ha-Na Choi
- Subjects
Family therapy ,Medical education ,Field (Bourdieu) ,Psychology ,Peer counseling - Published
- 2018
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12. Effect of Repeated Oral Health Education on the Oral Health of Preschool Children
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Jee-Won Lee and Ha-Na Choi
- Subjects
medicine.medical_specialty ,business.industry ,Family medicine ,Oral health education ,Medicine ,Oral health ,business - Published
- 2017
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13. Prosthetic Valve Endocarditis caused by HACEK Organisms: a Case Report and Systematic Review of the Literature
- Author
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Hyun Joon Kang, Ha Na Choi, Ki-Ho Park, Mi Suk Lee, Jae Hun Park, So Young Park, and Jae Min Kim
- Subjects
medicine.medical_specialty ,Case Report ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Antibiotic therapy ,Valve replacement surgery ,medicine ,Endocarditis ,Pharmacology (medical) ,030212 general & internal medicine ,Prosthetic valve endocarditis ,Heart valve prosthesis ,Prosthetic valve ,Aggregatibacter aphrophilus ,business.industry ,HACEK ,medicine.disease ,HACEK endocarditis ,Surgery ,Infectious Diseases ,Male patient ,Cardiology ,business - Abstract
HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A. aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months without recurrence.
- Published
- 2017
14. Clinical Usefulness of PCR for Differential Diagnosis of Tuberculosis and Nontuberculous Mycobacterial Infection in Paraffin-Embedded Lung Tissues
- Author
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Woo Sung Moon, Yo Na Kim, Kyu Yun Jang, Dong Geun Lee, Kyoung Min Kim, Ha Na Choi, Ho Sung Park, Myoung Ja Chung, Myoung Jae Kang, and Ju-Hyung Lee
- Subjects
Adult ,DNA, Bacterial ,Male ,Tuberculosis ,Biopsy ,Mycobacterium Infections, Nontuberculous ,Real-Time Polymerase Chain Reaction ,Sensitivity and Specificity ,Pathology and Forensic Medicine ,Microbiology ,Diagnosis, Differential ,Mycobacterium tuberculosis ,Tuberculosis diagnosis ,Predictive Value of Tests ,medicine ,Humans ,Lung ,Aged ,Aged, 80 and over ,Paraffin Embedding ,biology ,medicine.diagnostic_test ,business.industry ,Middle Aged ,bacterial infections and mycoses ,biology.organism_classification ,medicine.disease ,Staining ,Immunology ,Molecular Medicine ,Female ,Nontuberculous mycobacteria ,Differential diagnosis ,business ,Nested polymerase chain reaction - Abstract
The need for isolation of nontuberculous mycobacteria (NTM) from clinical specimens has increased in recent years. Our aim was to determine the clinical usefulness of PCR for differential diagnosis of tuberculosis and nontuberculous mycobacterial infection in lung tissue that show chronic granulomatous inflammation. A total of 199 formalin-fixed, paraffin-embedded specimens, including 137 Mycobacterium tuberculosis (MTB), 17 NTM cases, and 45 other than mycobacterial cases were collected. We performed acid-fast staining, MTB and NTM nested PCRs, and MTB and NTM real-time PCRs. No histologic difference between MTB and NTM infections was observed. Sensitivity and specificity for detecting MTB were 70.1% and 95.1% by nested PCR, respectively, and 70.8% and 100.0% by real-time PCR, respectively. Sensitivity and specificity for detecting NTM were 52.9% and 96.15% by nested PCR, respectively, and 35.3% and 100.0% by real-time PCR, respectively. Mycobacteria were identified by acid-fast staining in 50 of 154 cases (32.5%). All 50 acid-fast staining-positive cases showed positive nested and real-time PCR results (n = 47 MTB PCR positive; n = 3 NTM PCR positive), and results agreed with final diagnosis. PCR will be useful for the rapid diagnosis of mycobacterial infection and differentiation of MTB from NTM in formalin-fixed, paraffin-embedded specimens, especially in acid-fast staining-positive specimens.
- Published
- 2015
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15. Discriminative Feature Vector Selection for Emotion Classification Based on Speech
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Sung-Woo Byun, Ha-Na Choi, and Seok-Pil Lee
- Subjects
business.industry ,Feature vector ,Emotion classification ,Speech recognition ,Wearable computer ,Pattern recognition ,Cognition ,Discriminative model ,Bhattacharyya distance ,Artificial intelligence ,Mel-frequency cepstrum ,Electrical and Electronic Engineering ,Psychology ,business ,Human voice - Abstract
Recently, computer form were smaller than before because of computing technique"s development and many wearable device are formed. So, computer"s cognition of human emotion has importantly considered , thus researches on analyzing the state of emotion are increasing. Human voice includes many information of human emotion. This paper proposes a discriminative feature vector selection for emotion classification based on speech. For this, we extract some feature vectors like Pitch, MFCC, LPC, LPCC from voice signals are divided into four emotion parts on happy, normal, sad, angry and compare a separability of the extracted feature vectors using Bhattacharyya distance. So more effective feature vectors are recommended for emotion classification.
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- 2015
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16. Simple assessment of olfaction in patients with chronic rhinosinusitis
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Byung Guk Kim, So Young Park, Ha Na Choi, and Jeong-Hoon Oh
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Adult ,Male ,Natural Orifice Endoscopic Surgery ,medicine.medical_specialty ,Adolescent ,Visual Analog Scale ,Visual analogue scale ,Chronic rhinosinusitis ,Butanols ,Anosmia ,Olfaction ,Olfaction Disorders ,Young Adult ,Frontal Sinusitis ,Hyposmia ,medicine ,Humans ,In patient ,Child ,Aged ,Retrospective Studies ,business.industry ,General Medicine ,Middle Aged ,Surgery ,Smell ,Endoscopic sinus surgery ,Otorhinolaryngology ,Anesthesia ,Female ,medicine.symptom ,business - Abstract
The brief-smell identification test (B-SIT) can substitute for the butanol threshold test (BTT) in screening of anosmia and postoperative assessment of olfactory outcomes in patients with chronic rhinosinusitis (CRS). A time-effective test battery composed of B-SIT and the visual analog scale (VAS) can be implemented for simple olfactory assessment in any otolaryngology clinic.Anosmia is a distinct clinical entity requiring special attention. Unpredictable olfactory outcomes after surgery make preoperative assessment more important. We compared the results of the BTT, B-SIT, and VAS to investigate whether B-SIT or VAS can substitute for BTT in screening of anosmia and postoperative follow-up.We collected data on 68 CRS patients who had bilateral CRS and underwent endoscopic sinus surgery. Olfactory performance was graded using the BTT: normosmia, hyposmia, or anosmia. VAS and B-SIT were also performed. All tests were repeated 6 months after surgery. Postoperative improvement was defined by an increase of the BTT score ≥ 2.The B-SIT and VAS scores of the anomics were significantly lower than those of the normosmics. B-SIT discriminated anosmia with high specificity. Within the improvement group, postoperative increase of B-SIT/VAS score showed significance. However, neither the B-SIT nor the VAS differentiated between no change and deterioration of olfaction.
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- 2015
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17. Bankruptcy prediction using ensemble SVM model
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Dong Hoon Lim and Ha Na Choi
- Subjects
Engineering ,Majority rule ,Ensemble forecasting ,business.industry ,Word error rate ,Pattern recognition ,Machine learning ,computer.software_genre ,Ensemble learning ,Field (computer science) ,Cross-validation ,Support vector machine ,ComputingMethodologies_PATTERNRECOGNITION ,Bankruptcy prediction ,Artificial intelligence ,business ,computer - Abstract
Corporate bankruptcy prediction has been an important topic in the accounting and finance field for a long time. Several data mining techniques have been used for bankruptcy prediction. However, there are many limits for application to real classification problem with a single model. This study proposes ensemble SVM (support vector machine) model which assembles different SVM models with each different kernel functions. Our ensemble model is made and evaluated by v-fold cross-validation approach. The k top performing models are recruited into the ensemble. The classification is then carried out using the majority voting opinion of the ensemble. In this paper, we investigate the performance of ensemble SVM classifier in terms of accuracy, error rate, sensitivity, specificity, ROC curve, and AUC to compare with single SVM classifiers based on financial ratios dataset and simulation dataset. The results confirmed the advantages of our method: It is robust while providing good performance.
- Published
- 2013
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18. Characterization of CD45−/CD31+/CD105+ Circulating Cells in the Peripheral Blood of Patients with Gynecologic Malignancies
- Author
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Ki Heon Lee, Hyun Kyung Yu, Ji Young Choi, Jang Seong Kim, Ha Na Choi, Lee S.H. Yi, Tae Jin Kim, Sun Jin Kim, Ho Jeong Lee, Jin Hyung Ahn, Yeup Yoon, and Haengseok Song
- Subjects
CD31 ,Cancer Research ,Pathology ,medicine.medical_specialty ,medicine.diagnostic_test ,Angiogenesis ,business.industry ,CD68 ,CD14 ,Endoglin ,Flow cytometry ,Immunophenotyping ,Oncology ,Antigen ,cardiovascular system ,Cancer research ,medicine ,business - Abstract
Purpose: Circulating endothelial cells (CEC) have been widely used as a prognostic biomarker and regarded as a promising strategy for monitoring the response to treatment in several cancers. However, the presence and biologic roles of CECs have remained controversial for decades because technical standards for the identification and quantification of CECs have not been established. Here, we hypothesized that CECs detected by flow cytometry might be monocytes rather than endothelial cells. Experimental Design: The frequency of representative CEC subsets (i.e., CD45−/CD31+, CD45−/CD31+/CD146+, CD45−/CD31+/CD105+) was analyzed in the peripheral blood of patients with gynecologic cancer (n = 56) and healthy volunteers (n = 44). CD45−/CD31+ cells, which are components of CECs, were isolated and the expression of various markers (CD146, CD105, vWF, and CD144 for endothelial cells; CD68 and CD14 for monocytes) was examined by immunocytochemistry. Results: CD45−/CD31+/CD105+ cells were significantly increased in the peripheral blood of patients with cancer, whereas evaluation of CD45−/CD31+/CD146+ cells was not possible both in patients with cancer and healthy controls due to the limited resolution of the flow cytometry. Immunocytochemistry analyses showed that these CD45−/CD31+/CD105+ cells did not express vWF and CD146 but rather CD144. Furthermore, CD45−/CD31+/CD105+ cells uniformly expressed the monocyte-specific markers CD14 and CD68. These results suggest that CD45−/CD31+/CD105+ cells carry the characteristics of monocytes rather than endothelial cells. Conclusions: Our data indicate that CD45−/CD31+/CD105+ circulating cells, which are significantly increased in the peripheral blood of patients with gynecologic cancer, are monocytes rather than endothelial cells. Further investigation is required to determine the biologic significance of their presence and function in relation with angiogenesis. Clin Cancer Res; 19(19); 5340–50. ©2013 AACR.
- Published
- 2013
- Full Text
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19. Sustained overexpression of Redd1 leads to Akt activation involved in cell survival
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Tae-Boo Choe, Ha-Na Choi, Jae-Hee Kim, Sung-Eun Hong, Jin Kyung Lee, Karam Kim, Eun Kyu Kim, In-Chul Park, Hyun-Ah Kim, Jae Ho Lee, Sungkwan An, Seok-Il Hong, Hyeon-Ok Jin, Woo Chul Noh, Chang-Sun Hwang, Young Joon Hong, and Jong-Il Kim
- Subjects
Cancer Research ,Lung Neoplasms ,Cell Survival ,Mechanistic Target of Rapamycin Complex 2 ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,Transfection ,mTORC2 ,chemistry.chemical_compound ,Humans ,Phosphorylation ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Chemistry ,TOR Serine-Threonine Kinases ,Perifosine ,Enzyme Activation ,Oncology ,Multiprotein Complexes ,Cancer research ,Cisplatin ,biological phenomena, cell phenomena, and immunity ,Signal transduction ,Proto-Oncogene Proteins c-akt ,Signal Transduction ,Transcription Factors - Abstract
Herein, we show that the constitutive overexpression of Redd1, a negative regulator of mTORC1, induces Akt activation in lung cancer cells. Akt phosphorylation was reduced to basal levels by Rictor siRNA, suggesting the involvement of mTORC2 in this process. Perifosine and PP242, selective inhibitors of Akt and mTORC1/2, respectively, efficiently suppressed the Akt phosphorylation that was induced by the sustained overexpression of Redd1 and increased the sensitivity of the cells to cisplatin. Therefore, the sustained overexpression of Redd1 leads to mTORC1 inhibition and to consequent Akt activation that is involved in cell survival. This finding highlights the importance of Akt activation as a therapeutic target to overcome resistance to chemotherapy.
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- 2013
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20. Neuroprotective effects of N-acetylglucosamine against hydrogen peroxide-induced apoptosis in human neuronal SK-N-SH cells by inhibiting the activation of caspase-3, PARP, and p38
- Author
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Mi Ja Chung, Ha Na Choi, Jae Kweon Park, and Yong Il Park
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chemistry.chemical_classification ,Reactive oxygen species ,Programmed cell death ,Poly ADP ribose polymerase ,Caspase 3 ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Neuroprotection ,Molecular biology ,chemistry ,Apoptosis ,medicine ,DNA fragmentation ,Oxidative stress ,Food Science ,Biotechnology - Abstract
Neuroprotective effects of N-acetylglucosamine (GlcNAc), a monosaccharide derivative of glucose, against H2O2-induced neurotoxicity and its underlying mechanism in human SK-N-SH neuroblastoma cells were investigated. Pretreatment of GlcNAc prior to exposure of cells to H2O2 stress significantly reduced the H2O2-mediated neuronal cell death and apoptosis. The GlcNAc dose-dependently decreased the level of intracellular reactive oxygen species (ROS) in H2O2-treated cells and also effectively inhibited H2O2-induced apoptotic features such as DNA fragmentation, caspase-3, and poly ADP-ribose polymerase (PARP) cleavages, and p38 phosphorylation. These results suggested that GlcNAc might potentially serve as agents for prevention of neurodegenerative diseases caused by oxidative stresses and this effect may be associated with the suppression of caspase-3, PARP, and p38 activation.
- Published
- 2013
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21. Inhibition of S6K1 enhances glucose deprivation-induced cell death via downregulation of anti-apoptotic proteins in MCF-7 breast cancer cells
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Jin Kyung Lee, Hyeon-Ok Jin, Eun Kyu Kim, Sung-Eun Hong, In-Chul Park, Jae-Hee Kim, Hyun-Ah Kim, Woo Chul Noh, and Ha-Na Choi
- Subjects
Niacinamide ,Programmed cell death ,Survivin ,Biophysics ,Down-Regulation ,Apoptosis ,Breast Neoplasms ,P70-S6 Kinase 1 ,Biology ,Biochemistry ,Piperazines ,Inhibitor of Apoptosis Proteins ,Downregulation and upregulation ,Humans ,Protein Kinase Inhibitors ,Molecular Biology ,PI3K/AKT/mTOR pathway ,Kinase ,Phenylurea Compounds ,TOR Serine-Threonine Kinases ,Imidazoles ,Ribosomal Protein S6 Kinases, 70-kDa ,Cell Biology ,Sorafenib ,Cell biology ,Glucose ,Proto-Oncogene Proteins c-bcl-2 ,MCF-7 ,Gene Knockdown Techniques ,MCF-7 Cells ,Myeloid Cell Leukemia Sequence 1 Protein ,Female ,Apoptosis Regulatory Proteins - Abstract
Nutrient-limiting conditions are frequently encountered by tumor cells in poorly vascularized microenvironments. These stress conditions may facilitate the selection of tumor cells with an inherent ability to decrease apoptotic potential. Therefore, selective targeting of tumor cells under glucose deprivation conditions may provide an effective alternative strategy for cancer therapy. In the present study, we investigated the effects of S6 kinase 1 (S6K1) inhibition on glucose deprivation-induced cell death and the underlying mechanisms in MCF-7 breast cancer cells. PF4708671, a selective inhibitor of S6K1, and knockdown of S6K1 with specific siRNA enhanced cell death induced under glucose deprivation conditions. Moreover, inhibition of S6K1 led to apoptosis in glucose-starved MCF-7 cells via downregulation of the anti-apoptotic proteins, Mcl-1 and survivin. Further experiments revealed that sorafenib, shown to be involved in Mcl-1 and survivin downregulation via mTOR/S6K1 inhibition significantly promotes cell death under glucose deprivation conditions. These findings collectively suggest that S6K1 plays an important role in tumor cell survival under stress conditions, and thus inhibition of S6K1 may be an effective strategy for sensitizing cells to glucose deprivation.
- Published
- 2013
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22. Purification and characterization of a polysialic acid-specific sialidase from Pseudomonas fluorescens JK-0412
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Ha Na Choi, Choul-Gyun Lee, Doo Jin Choi, Jae Kweon Park, Sung Jae Jang, Sung Min Kim, Young Kug Choo, Yong Il Park, and Joo Woong Park
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chemistry.chemical_classification ,Chromatography ,Molecular mass ,biology ,Polysialic acid ,Biomedical Engineering ,Bioengineering ,Pseudomonas fluorescens ,biology.organism_classification ,Sialidase ,Applied Microbiology and Biotechnology ,Enzyme ,chemistry ,Biochemistry ,Chitin binding ,Serratia marcescens ,Peptide sequence ,Biotechnology - Abstract
An enzyme with polySia degrading activity was purified from a culture filtrate of Pseudomonas fluorescens JK-0412 to apparent homogeneity using DEAE-Sepharose CL-6B column chomatography and fast performance liquid chomatography separation on a Mono-Q column. The molecular mass of the purified enzyme (tentatively named Endo-PS) was approximately 20 kDa on SDS-PAGE and 120 kDa on native-PAGE gels, suggesting that the active form is a hexamer. Although 12 residues of the Endo-PS N-terminal amino acid sequence showed 75% homology to the 21 kDa chitin binding protein (CBP21) of Serratia marcescens 2170, no significant similarity to other known proteins was observed. Apparent K m and V max values of Endo-PS toward the artificial substrate 4-methylumbelliferyl-sialic acid (4-MU-Neu5Ac) were 0.08 mM and 16 nmol/mg/min, respectively. The enzyme was maximally active at 37°C and pH 8.0. Interestingly, the enzyme was shown to hydrolyze the natural substrate, α2,8-linked polySia (colominic acid), in an endo-acting manner. However, no activity toward α2,3- or α2,6-sialyllactose was observed. Under optimal conditions, oligoSia ranging from 2 to 30 residues long were liberated by the cleavage of polySia, as identified by HPAEC-PED. Therefore, the purified enzyme Endo-PS was found to be a polySia-specific sialidase. This is the first report to describe the properties of a bacterial polySia-specific sialidase. Therefore, this enzyme may be a useful tool for both industrial oligoSia production and research on the structure and biological functions of polySia in nature.
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- 2012
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23. Neuroprotective effects of black soybean anthocyanins via inactivation of ASK1–JNK/p38 pathways and mobilization of cellular sialic acids
- Author
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Su Il Do, Young Kug Choo, Seongjae Jang, Sung Min Kim, Sung Oog Kim, Ha Na Choi, Myung Hoon Chun, Yong Il Park, Tae Joung Ha, and Mi Ja Chung
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Cell Survival ,Biology ,MAP Kinase Kinase Kinase 5 ,medicine.disease_cause ,p38 Mitogen-Activated Protein Kinases ,Antioxidants ,General Biochemistry, Genetics and Molecular Biology ,Anthocyanins ,Neuroblastoma ,chemistry.chemical_compound ,Glucosides ,Cell Line, Tumor ,medicine ,Humans ,ASK1 ,MTT assay ,Viability assay ,General Pharmacology, Toxicology and Pharmaceutics ,chemistry.chemical_classification ,Reactive oxygen species ,Cell Death ,Kinase ,JNK Mitogen-Activated Protein Kinases ,food and beverages ,Hydrogen Peroxide ,General Medicine ,Molecular biology ,Sialic acid ,Heme oxygenase ,Oxidative Stress ,Neuroprotective Agents ,Gene Expression Regulation ,Biochemistry ,chemistry ,Sialic Acids ,Soybeans ,Reactive Oxygen Species ,Oxidative stress - Abstract
Aims To investigate neuroprotective effects of three major anthocyanins (cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, and petunidin-3-O-glucoside) isolated from the black soybean (Glycine max L.) cv. Cheongja 3 seed coat against H2O2-induced cell death of human brain neuroblastoma SK-N-SH cells. Main methods Cell viability, reactive oxygen species (ROS) generation, production and expression of heme oxygenase (HO)-1 and inactivation of mitogen-activated protein (MAP) kinase cascades were determined by MTT assay, 2,7-dichlorofluorescein diacetate (DCF-DA) assay, reverse transcriptase polymerase chain reaction (RT-PCR), and western blotting, respectively. Key findings Pretreatment with anthocyanins reduced the cytotoxicity of H2O2 on SK-N-SH cells, dose-dependently reduced the intracellular ROS level and inactivated apoptosis signal-regulating kinase (ASK1, Thr845), p38, and c-Jun N-terminal kinase (JNK) proteins. The HO-1 and Neu1 mRNA levels were increased by H2O2 (25 μM) and further elevated by the pretreatment with anthocyanins. Sialic acids added to the culture plates not only attenuated the cytotoxicity of H2O2 (25 μM) but also reduced intracellular ROS level. These results suggest that Cheongja 3 black soybean seed coat anthocyanins have brain neuroprotective effects against oxidative stress (H2O2) by inhibiting the activation of ASK1–JNK/p38 pathways, scavenging ROS, stimulating the expression of HO-1 and, more interestingly, recruiting cellular free sialic acids through up-regulation of Neu1 sialidase gene expression. Significance This is the first report indicating potent health benefits of black soybean seed coat anthocyanins in neuroprotection by triggering mobilization of cellular free sialic acid and utilizing it as an additional biological antioxidant in brain neural cells.
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- 2012
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24. Synthesis and Characterization of Nickel(II) Aminoalkoxides: Application to Molecular Precursors for MOCVD of Ni Thin Films
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Young Lee, Chang Gyoun Kim, Seung Ho Yoo, Ki-Seok An, Hyo-Suk Kim, Bo Keun Park, Sun Sook Lee, Taek-Mo Chung, and Ha-Na Choi
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Chemistry ,Inorganic chemistry ,chemistry.chemical_element ,Chemical vapor deposition ,Carbon-13 NMR ,Decomposition ,Inorganic Chemistry ,Metal ,Nickel ,visual_art ,Proton NMR ,visual_art.visual_art_medium ,Metalorganic vapour phase epitaxy ,Thin film ,Nuclear chemistry - Abstract
Novel single precursors for Ni, Ni(dmamp)2 (1), Ni(deamp)2 (2), and Ni(emamp)2 (3), were synthesized by the metathesis reaction between [Ni(NH3)6]Cl2 and two equiv. of Na(dmamp), Na(deamp), and Na(emamp), respectively. Complexes 1–3 have been characterized by IR, 1H NMR, and 13C NMR spectroscopies, and microanalytical data, as well as single-crystal X-ray diffraction studies. Through GC/MS analysis of the gaseous species generated by the decomposition of 1, a self-reduction pathway to form metallic Ni was studied. By the metalorganic chemical vapor deposition of 1, metallic Ni hexagonal-phase thin films were obtained at 250 °C and cubic-phase thin films were obtained at 400 °C.
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- 2011
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25. Dihydroavenanthramide D protects pancreatic β-cells from cytokine and streptozotocin toxicity
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Young-Rae Lee, Ha-Na Choi, Jin-Woo Park, Kang-Beom Kwon, Byung-Hyun Park, Na Lv, and Mi-Young Song
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Male ,medicine.medical_specialty ,Avena ,medicine.medical_treatment ,Interleukin-1beta ,Biophysics ,Biology ,Biochemistry ,Antioxidants ,Streptozocin ,Nitric oxide ,Interferon-gamma ,Mice ,chemistry.chemical_compound ,Cell Line, Tumor ,Insulin-Secreting Cells ,Internal medicine ,medicine ,Animals ,ortho-Aminobenzoates ,Molecular Biology ,Insulinoma ,Mice, Inbred ICR ,Type 1 diabetes ,Cell Death ,Insulin ,Anti-Inflammatory Agents, Non-Steroidal ,NF-kappa B ,Cell Biology ,medicine.disease ,Streptozotocin ,Endocrinology ,medicine.anatomical_structure ,Cytokine ,chemistry ,Cytoprotection ,Toxicity ,Cytokines ,Pancreas ,medicine.drug - Abstract
Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Although its anti-inflammatory, antiatherosclerotic, and antioxidant effects have been reported, the effect of DHAvD on type 1 diabetes is unknown. Therefore, in this study, the effect of DHAvD on cytokine- or streptozotocin-induced beta-cell damage was investigated. Treatment of RINm5F insulinoma cells or isolated islets with IL-1beta and IFN-gamma induced beta-cell damage through a NF-kappaB-dependent signaling pathway. DHAvD-pretreated RINm5F cells or islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced the inducible form of NO synthase expression, and decreased beta-cell destruction and the normal insulin secretion capacity. Furthermore, pretreatment with DHAvD blocked the development of type 1 diabetes in streptozotocin-treated mice. Prior injection with DHAvD maintained a normal range of plasma glucose and insulin, and retained immunoreactivity for insulin in the pancreas. These results suggest that DHAvD may be used to preserve functional beta-cell mass.
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- 2009
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26. JANEX-1, a JAK3 inhibitor, protects pancreatic islets from cytokine toxicity through downregulation of NF-κB activation and the JAK/STAT pathway
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Eun-Kyung Kim, Kang-Beom Kwon, Na Lv, Byung-Hyun Park, Jin-Woo Park, Sung-Joo Park, Ha-Na Choi, Mi-Young Song, and Woo Sung Moon
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Male ,medicine.medical_specialty ,Cell Survival ,medicine.medical_treatment ,Interleukin-1beta ,Down-Regulation ,Nitric Oxide Synthase Type II ,Suppressor of Cytokine Signaling Proteins ,Biology ,Rats, Sprague-Dawley ,Interferon-gamma ,Mice ,chemistry.chemical_compound ,Suppressor of Cytokine Signaling 1 Protein ,Downregulation and upregulation ,Insulin-Secreting Cells ,Internal medicine ,medicine ,Animals ,Phosphorylation ,Cells, Cultured ,Pancreatic islets ,Janus kinase 3 ,NF-kappa B ,Janus Kinase 3 ,JAK-STAT signaling pathway ,NF-κB ,Cell Biology ,Rats ,STAT Transcription Factors ,Endocrinology ,medicine.anatomical_structure ,Cytokine ,chemistry ,Suppressor of Cytokine Signaling 3 Protein ,Quinazolines ,STAT protein ,Cancer research ,Signal transduction ,Signal Transduction - Abstract
JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic beta-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1beta and interferon (IFN)-gamma-induced beta-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor kappaB (NF-kappaB) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3(-/-) mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects beta-cells from cytokine toxicity through suppression of the NF-kappaB and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional beta-cell mass.
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- 2009
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27. Flora of Vascular Plants on Mt. Kookmang(Chungju, Chungbuk)
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Myeong Soon Park, Jung Soo Suh, Gyu Young Chung, Ha Na Choi, Sun Hee Lee, and Su Young Jung
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Flora ,Botany ,Biology - Published
- 2008
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28. Flora of Vascular Plants on Mt. Boryeon(Cheongju)
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Gyu-Young Chung, Ha-Na Choi, Myeong-Soon Park, Jung Soo Suh, Su Young Jung, and Sun Hee Lee
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Flora ,Botany ,Biology - Published
- 2007
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29. Do sinus computed tomography findings predict olfactory dysfunction and its postoperative recovery in chronic rhinosinusitis patients?
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Young Hoon Jung, Ji Hyun Shin, Ha Na Choi, So Young Park, Jun Myung Kang, and Byung Guk Kim
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Chronic rhinosinusitis ,Computed tomography ,Postoperative recovery ,X ray computed ,Paranasal Sinuses ,otorhinolaryngologic diseases ,medicine ,Immunology and Allergy ,Humans ,Sinusitis ,Child ,Sinus (anatomy) ,Aged ,Rhinitis ,medicine.diagnostic_test ,business.industry ,General Medicine ,Middle Aged ,Surgery ,Smell ,Endoscopic sinus surgery ,Chronic disease ,medicine.anatomical_structure ,Otorhinolaryngology ,Chronic Disease ,Female ,OLFACTORY IMPAIRMENT ,business ,Tomography, X-Ray Computed - Abstract
Background Olfactory dysfunction secondary to chronic rhinosinusitis (CRS) is a mixed disorder of conductive and sensorineural olfactory impairment. Although endoscopic sinus surgery has some beneficial effects on olfaction, the outcomes are challenging to predict. The aim of this study was to assess the olfactory outcomes after surgery, to investigate the correlation between the severity of regional computed tomography (CT) findings and olfactory performance, and to identify the predictors of postoperative outcomes based on unilateral olfactory threshold analysis. Methods This study included 167 CRS nostrils of 97 patients with/without polyps (68/99 nostrils) undergoing sinus surgery between January 2007 and December 2011. Olfactory function was evaluated using the butanol threshold test (BTT) before and 6 months after surgery. Clinical and nasal factors from sinus CT scan (sinuses, ostiomeatal complex, olfactory cleft [OC], nasal polyps, and unilateral Lund-Mackay CT score) were analyzed to correlate them with pre- and postoperative olfactory performances. Results Eighty-two percent of the CRS nostrils had anosmia or hyposmia. After surgery, 42% of them showed an improvement in BTT score. Despite improvement, most of the subjects remained with residual hyposmia. The BTT scores deteriorated after surgery in 23% of the total subjects. The disease severity of the OC, posterior ethmoid, and frontal sinus were the significant risk factors for CRS-related anosmia. The strongest risk factor for anosmia was totally obstructed OC (odds ratio [OR], 16.56; 95% CI, 4.31-63.71; p = 0.000). The nostrils with anosmia or partly opacified anterior ethmoid benefited from surgery with respect to olfaction. Conclusion Our results can give support to the combined use of the butanol threshold and sinonasal CT findings in the evaluation of olfaction in CRS patients and help us counsel the patients about the likelihood of postoperative olfactory recovery.
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- 2015
30. Knockdown of TWIST1 enhances arsenic trioxide- and ionizing radiation-induced cell death in lung cancer cells by promoting mitochondrial dysfunction
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Sang-Gu Hwang, Jae-Hee Kim, In-Chul Park, Sung-Keum Seo, Seok-Il Hong, Tae-Boo Choe, Jae-Youn Yi, Yun-Han Lee, Lee Hj, and Ha-Na Choi
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FIS1 ,Small interfering RNA ,Programmed cell death ,animal structures ,Biophysics ,Mitochondrion ,Biology ,Biochemistry ,Arsenicals ,chemistry.chemical_compound ,Arsenic Trioxide ,Carcinoma, Non-Small-Cell Lung ,Radiation, Ionizing ,Humans ,Epithelial–mesenchymal transition ,Arsenic trioxide ,RNA, Small Interfering ,Molecular Biology ,Membrane Potential, Mitochondrial ,Cell Death ,Twist-Related Protein 1 ,Nuclear Proteins ,Oxides ,Cell Biology ,Cell biology ,Acetylcysteine ,chemistry ,Apoptosis ,Gene Knockdown Techniques ,Cancer cell ,Reactive Oxygen Species - Abstract
TWIST1 is implicated in the process of epithelial mesenchymal transition, metastasis, stemness, and drug resistance in cancer cells, and therefore is a potential target for cancer therapy. In the present study, we found that knockdown of TWIST1 by small interfering RNA (siRNA) enhanced arsenic trioxide (ATO)- and ionizing radiation (IR)-induced cell death in non-small-cell lung cancer cells. Interestingly, intracellular reactive oxygen species levels were increased in cells treated with TWIST1 siRNA and further increased by co-treatment with ATO or IR. Pretreatment of lung cancer cells with the antioxidant N-acetyl-cysteine markedly suppressed the cell death induced by combined treatment with TWIST1 siRNA and ATO or IR. Moreover, treatment of cells with TWIST1 siRNA induced mitochondrial membrane depolarization and significantly increased mitochondrial fragmentation (fission) and upregulated the fission-related proteins FIS1 and DRP1. Collectively, our results demonstrate that siRNA-mediated TWIST1 knockdown induces mitochondrial dysfunction and enhances IR- and ATO-induced cell death in lung cancer cells.
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- 2014
31. A Study on the Enhancement Factor Rating Classes of Middle School Ballet Representation Activities
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Ha-Na Choi
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Ballet ,Factor (programming language) ,Pedagogy ,Mathematics education ,Representation (systemics) ,Psychology ,computer ,computer.programming_language - Published
- 2016
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32. Expression of K19 and K7 in dysplastic nodules and hepatocellular carcinoma
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Cheol Keun Park, Woo Sung Moon, Byung Hyun Park, Sang Jae Noh, Kyu Yun Jang, Ha Na Choi, and Jun Sang Bae
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Cancer Research ,Pathology ,medicine.medical_specialty ,Tissue microarray ,Oncogene ,business.industry ,Cancer ,Articles ,HCCS ,medicine.disease ,digestive system diseases ,Oncology ,Hepatocellular carcinoma ,Atypia ,medicine ,Carcinoma ,Immunohistochemistry ,business ,neoplasms - Abstract
Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumors characterized by a multistep process of tumor development. Nodular lesions that differ from the surrounding liver parenchyma and are characterized by cytological or structural atypia are termed dysplastic nodules (DNs). DNs are well-known precancerous HCC lesions. Expression of keratin (K) 19 and K7, molecular markers of hepatic progenitor cells and cholangiocytes, has been reported in certain HCCs. However, it remains unclear whether K19-positive HCC cells are derived from true hepatic progenitor cells or mature cells that have undergone a dedifferentiation or a transdifferentiation process. In total, 107 tissue sections (13 low-grade DNs, 15 high-grade DNs, 27 small HCCs and 52 large HCCs) from resected liver samples and 132 HCC tissue microarray (TMA) cores were subjected to immunohistochemical analysis for K19 and K7. Clinicopathological data of the HCC patients were evaluated. K19 expression was found in 0% of DNs, 19% of small HCCs (≤2 cm), 8% of large HCCs (>2 cm) and 8% of TMA samples. K7 expression was found in 14% of DNs, 41% of small HCCs, 15% of large HCCs and 6% of TMA samples. Among the five K19-positive small HCCs, four were distinctly nodular and one tumor was an infiltrative type. No vaguely nodular HCC was positive for K19. K19 expression was significantly associated with histological grade (P=0.023), serum α-fetoprotein level (P=0.001) and K7 expression (P=0.001) in HCC. K19 expression was an independent prognostic factor for overall survival in non-viral HCC patients (P=0.003). K19 expression is extremely rare in DNs and occurs in progressed small HCCs. Our results suggest that K19 expression may be an acquired feature of carcinoma cells during HCC progression in certain HCCs.
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- 2012
33. The role of serum response factor in hepatocellular carcinoma: an association with matrix metalloproteinase
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Jun Sang Bae, Ho Sung Park, Kyu Yun Jang, Ha Na Choi, Woo Sung Moon, Kyung Ryoul Kim, and Myoung Ja Chung
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Cancer Research ,Serum Response Factor ,Carcinoma, Hepatocellular ,genetic structures ,Cell ,Gene Expression ,Matrix metalloproteinase ,Biology ,Downregulation and upregulation ,Cell Movement ,Cell Line, Tumor ,Serum response factor ,Gene expression ,medicine ,Humans ,Enzyme Assays ,Oncogene ,Liver Neoplasms ,General Medicine ,Transfection ,Cell cycle ,musculoskeletal system ,Recombinant Proteins ,medicine.anatomical_structure ,Oncology ,Matrix Metalloproteinase 9 ,embryonic structures ,cardiovascular system ,Cancer research ,Matrix Metalloproteinase 2 ,sense organs - Abstract
Serum response factor (SRF) regulates tran-scription of immediate early genes and triggers proliferation, migration and differentiation in several types of cells. Matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases, play a crucial role in tumor invasion and metastasis. However, expression of SRF and its association with MMPs in hepatocellular carcinoma (HCC) have not been elucidated. We examined the expression levels of SRF, MMP-2 and MMP-9 in HCC tissues using Western blot assay. We also examined the effect of SRF on MMP expression and enzyme activity in HCC by transfection of SRF cDNA in HLE cells. Protein expression of SRF, MMP-2 and MMP-9 showed a significant increase in HCC tissues, compared with those of corresponding non-tumor tissues. High SRF expressing HCC tissues showed higher levels of expression of MMP-2 and MMP-9, compared with low SRF expressing HCC tissues. In addition, overexpression of SRF in HLE cells led to increased levels of expression of mRNA and protein, as well as increased enzyme activity of MMP-2 and MMP-9. Overexpression of SRF also led to significantly enhanced migration of HLE cells. These results suggest that overexpression of SRF in HCC may play an important role in tumor cell migration and invasion through upregulation of MMP-2 and MMP-9.
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- 2011
34. Expression and role of SIRT1 in hepatocellular carcinoma
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Myoung Jae Kang, Dong Geun Lee, Sang Jae Noh, Urangoo Jamiyandorj, Ha Na Choi, Kyu Yun Jang, Jun Sang Bae, Ho Sung Park, Myoung Ja Chung, and Woo Sung Moon
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Adult ,Cancer Research ,medicine.medical_specialty ,Small interfering RNA ,Carcinoma, Hepatocellular ,endocrine system diseases ,Cell ,Biology ,Transfection ,Sirtuin 1 ,RNA interference ,Cell Line, Tumor ,Internal medicine ,medicine ,Humans ,Gene silencing ,RNA, Small Interfering ,Aged ,Retrospective Studies ,Oncogene ,Cell growth ,Liver Neoplasms ,General Medicine ,Middle Aged ,Cell cycle ,Genes, p53 ,Immunohistochemistry ,digestive system diseases ,enzymes and coenzymes (carbohydrates) ,medicine.anatomical_structure ,Endocrinology ,Oncology ,Cancer cell ,Cancer research ,Tumor Suppressor Protein p53 ,biological phenomena, cell phenomena, and immunity ,hormones, hormone substitutes, and hormone antagonists - Abstract
Silent mating type information regulation 2 homolog 1 (SIRT1) is a multifaceted, nicotinamide adenine dinucleotide-dependent protein deacetylase with involvement in a wide variety of cellular processes ranging from cancer to aging. Expression of SIRT1 was evaluated in 90 cases of he p atocellular carcinoma (HCC) and five HCC cell lines. The relationship between the mutation status of p53 and expression of SIRT1 was also investigated in 10 fresh HCC tissues. Synthetic small interfering RNA was used to silence SIRT1 gene expression by RNA interference (RNAi), and cell growth and cell cycle progression were assessed. Expression of SIRT1 was significantly elevated in the HCC tissues when compared to that of non-tumor tissues (p
- Published
- 2011
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35. Increased expression of epidermal growth factor receptor and betacellulin during the early stage of gastric ulcer healing
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Myoung Jae Kang, Geun Hae Choi, Woo Sung Moon, Kyung Ryoul Kim, Kyu Yun Jang, Ha Na Choi, Ho Sung Park, Myoung Ja Chung, and Dong Geun Lee
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Cancer Research ,Betacellulin ,Oncogene ,biology ,Biochemistry ,digestive system diseases ,Proliferating cell nuclear antigen ,Oncology ,Genetics ,biology.protein ,Cancer research ,Molecular Medicine ,Immunohistochemistry ,Growth factor receptor inhibitor ,Epidermal growth factor receptor ,Molecular Biology ,A431 cells ,Immunostaining - Abstract
Epidermal growth factor receptor (EGFR) is important for the proliferation and differentiation of gastric mucosal cells. Betacellulin (BTC) is a novel ligand for EGFR Since their role is unclear in the ulcer healing process, we investigated their expression. Gastric ulcers in 30 Sprague-Dawley rats were induced by acetic acid. RT-PCR and Western blotting were performed to detect EGFR and BTC. Immunohistochemical studies were performed to detect EGFR, BTC and proliferating cell nuclear antigen (PCNA). The expression of EGFR and the BTC gene was significantly increased at 12 h, 24 h and 3 days after ulcer induction (P
- Published
- 2011
36. Effects of the molecular weight and the degree of deacetylation of chitosan oligosaccharides on antitumor activity
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Yong Il Park, Mi Ja Chung, Jae Kweon Park, and Ha Na Choi
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degree of deacetylation ,Stereochemistry ,Oligosaccharides ,Antineoplastic Agents ,Mass spectrometry ,Catalysis ,Article ,Inorganic Chemistry ,Chitosan ,lcsh:Chemistry ,chemistry.chemical_compound ,Glucosamine ,Enzymatic hydrolysis ,Cell Line, Tumor ,Humans ,MALDI-TOF MS ,antitumor activity ,Physical and Theoretical Chemistry ,Molecular Biology ,lcsh:QH301-705.5 ,Spectroscopy ,Cell Proliferation ,Chromatography ,Molecular mass ,Chemistry ,Cell growth ,Organic Chemistry ,chitosan oligosaccharides ,molecular weight ,Acetylation ,General Medicine ,Hep G2 Cells ,Computer Science Applications ,Matrix-assisted laser desorption/ionization ,lcsh:Biology (General) ,lcsh:QD1-999 - Abstract
Effects of the degree of deacetylation (DDA) and the molecular mass of chitosan oligosaccharides (CTS-OS), obtained from the enzymatic hydrolysis of high molecular weight chitosan (HMWC), on antitumor activity was explored. The DDA and molecular weights of CTS-OS were determined by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-TOF MS) analysis. The CTS-OS were found to be a mixture of mainly dimers (18.8%), trimers (24.8%), tetramers (24.9%), pentamers (17.7%), hexamers (7.1%), heptamers (3.3%), and octamers (3.4%). The CTS-OS were further fractionated by gel-filtration chromatography into two major fractions: (1) COS, consisting of glucosamine (GlcN)(n), n = 3-5 with DDA 100%; and (2) HOS, consisting of (GlcN)(5) as the minimum residues and varying number of N-acetylglucosamine (GlcNAc)(n), n = 1-2 with DDA about 87.5% in random order. The cytotoxicities, expressed as the concentration needed for 50% cell death (CC(50)), of CTS-OS, COS, and HOS against PC3 (prostate cancer cell), A549 (lung cancer cell), and HepG2 (hepatoma cell), were determined to be 25 μg·mL(-1), 25 μg·mL(-1), and 50 μg·mL(-1), respectively. The HMWC was approximately 50% less effective than both CTS-OS and COS. These results demonstrate that the molecular weight and DDA of chitosan oligosaccharides are important factors for suppressing cancer cell growth.
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- 2010
37. The role of serum response factor in hepatocellular carcinoma: implications for disease progression
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Dong Geun Lee, Myoung Ja Chung, Dae Ghon Kim, Woo Sung Moon, Ha Na Choi, Myoung Jae Kang, Kyung Ryoul Kim, Chang Young Kwon, and Sang Jae Noh
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Cancer Research ,Serum Response Factor ,RHOA ,Carcinoma, Hepatocellular ,Epithelial-Mesenchymal Transition ,genetic structures ,Transfection ,Antigens, CD ,Cell Movement ,Cell Line, Tumor ,Serum response factor ,Humans ,Vimentin ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Cell Shape ,Genes, Immediate-Early ,beta Catenin ,Cell Proliferation ,Oncogene ,biology ,Liver Neoplasms ,Wnt signaling pathway ,Cell migration ,musculoskeletal system ,Cadherins ,Actins ,Gene Expression Regulation, Neoplastic ,Wnt Proteins ,Oncology ,Catenin ,embryonic structures ,cardiovascular system ,Cancer research ,biology.protein ,Disease Progression ,RNA Interference ,sense organs ,rhoA GTP-Binding Protein - Abstract
Serum response factor (SRF) regulates transcription of the immediate early genes and triggers proliferation, migration and differentiation in several types of cells. We examined the role of SRF in HCC by transfecting the SRF cDNA in HLE cells and the SRF anti-sense cDNA in sarcomatoid HCC cells. The overexpression of SRF in the HLE cells significantly increased the cell growth and proliferation. Overexpression of SRF increased actin polymerization of the HCC cells and induced morphologic changes. The mesenchymal markers vimentin, N-cadherin and RhoA were highly expressed in the SRF-transfected HLE cells. Furthermore, the overexpression of SRF in the HLE cells increased the expression levels of the active form of the beta-catenin and Wnt/beta-catenin target genes, such as c-myc and cyclin D1. The overexpression of SRF significantly enhanced the cell migration and invasiveness of HCC cells. Conversely, inhibition of the SRF expression in the sarcomatoid SH-J1 cells by the SRF anti-sense cDNA significantly decreased migration and invasion through the attenuated expression of mesenchymal markers and the proteins involved in the Wnt/beta-catenin pathway. These results indicate that the overexpression of SRF in HCC cells modulates the Wnt/beta-catenin pathway, and this plays an important role in HCC progression.
- Published
- 2010
38. Der Erfolg interdisziplinärer Gründungslehre am Beispiel der FH Bonn-Rhein-Sieg
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Ha-Na Choi, Sarah Luna Weaver, and Christoph Zacharias
- Abstract
In den Medien wird momentan immer mehr die Rolle von klein- und mittelstandischen Betrieben, als „Jobmotor“ fur Deutschland betont. Darunter fallen auch Neugrundungen. Wirtschaftspolitisch interessant sind deswegen vor allem innovative, wachstumsstarke Existenzgrundungen. Verschiedene Untersuchungen geben Grund zu der Annahme, dass vornehmlich Hochschulabsolventen solche Unternehmen grunden. „Unternehmerisches Denken“ ist eine Schlusselqualifikation geworden, die fur die berufliche Zukunft von Hochschulabsolventen von steigender Bedeutung ist. Unternehmern zugesprochene Eigenschaften, wie Eigeninitiative, Ubernahme von Verantwortung, Fuhrungsqualitat und Belastbarkeit auch in besonderen Stresssituationen sind fur viele etablierte Unternehmen als Einstellungskriterium fur Akademiker starker in den Vordergrund geruckt.
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- 2009
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39. Serum response factor enhances liver metastasis of colorectal carcinoma via alteration of the E-cadherin/beta-catenin complex
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Ha Na, Choi, Kyung Ryoul, Kim, Ji Hyun, Lee, Ho Sung, Park, Kyu Yun, Jang, Myoung Ja, Chung, Si Eun, Hwang, Hee Chul, Yu, and Woo Sung, Moon
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Adult ,Aged, 80 and over ,Male ,Serum Response Factor ,Blotting, Western ,Liver Neoplasms ,Middle Aged ,Cadherins ,Transfection ,Immunohistochemistry ,Cell Line, Tumor ,Biomarkers, Tumor ,Humans ,Female ,Colorectal Neoplasms ,beta Catenin ,Aged - Abstract
Serum response factor (SRF) is a transcription factor that controls cell growth, differentiation, and tumor progression as well as muscle development and function. Reduced expression of cell adhesion molecules has been reported to be associated with tumor metastasis. The aim of this study was to evaluate the expression and a role of SRF in liver metastasis of primary colorectal carcinomas. We examined the expression of SRF, E-cadherin, and beta-catenin by the use of immunochemical staining in 43 cases as a set of primary colorectal carcinomas and liver metastases. We also examined the role of SRF in colorectal carcinoma by overexpression of SRF in a colon cancer cell line. In metastatic carcinoma surgical samples, there was a marked increased expression of SRF as compared to expression in primary colorectal carcinoma surgical samples (P0.05). E-cadherin expression was significantly decreased in metastatic liver carcinoma samples as compared to primary colorectal carcinoma samples (P0.001). Frequent nuclear translocation of beta-catenin protein in primary and metastatic carcinoma cells was observed. Overexpression of SRF in SW480 cells resulted in a decreased expression of E-cadherin and an increased expression of non-phosphorylated nuclear beta-catenin. Overexpression of SRF in colorectal carcinoma cells enhanced cell motility and invasiveness. These results indicate that overexpression of SRF in colorectal carcinoma cells is associated with modulation of E-cadherin/beta-catenin expression and may play an important role in colorectal cancer metastasis.
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- 2008
40. SIRT1 expression is associated with poor prognosis of diffuse large B-cell lymphoma
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Sung Ho Hwang, Woo Sung Moon, Ho Sung Park, Dong Geun Lee, Kyung Ryoul Kim, Jae-Yong Kwak, Hyeok Shim, Myoung Ja Chung, Byung-Hyun Park, Hun Soo Kim, Ha Na Choi, Na-Ri Lee, Keun Sang Kwon, Kyu Yun Jang, and Myoung Jae Kang
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Oncology ,Male ,Pathology ,medicine.medical_specialty ,Time Factors ,Kaplan-Meier Estimate ,Biology ,Disease-Free Survival ,Pathology and Forensic Medicine ,Sirtuin 1 ,immune system diseases ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Biomarkers, Tumor ,Humans ,Sirtuins ,B cell ,Proportional Hazards Models ,Univariate analysis ,B-Lymphocytes ,Tissue microarray ,Cancer ,Germinal center ,Middle Aged ,BCL6 ,medicine.disease ,Germinal Center ,Immunohistochemistry ,Lymphoma ,medicine.anatomical_structure ,Treatment Outcome ,Proto-Oncogene Proteins c-bcl-2 ,Tissue Array Analysis ,Interferon Regulatory Factors ,Surgery ,Female ,Neprilysin ,Lymphoma, Large B-Cell, Diffuse ,Anatomy ,Tumor Suppressor Protein p53 ,Diffuse large B-cell lymphoma - Abstract
Sirtuin1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent deacetylase. Recently, it is suggested that SIRT1 may be involved in the development of malignant tumors including mouse lymphoma. Therefore, we investigated the prevalence and the prognostic impact of SIRT1 expression in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical expression of SIRT1, p53, bcl2, CD10, bcl6, and multiple myeloma-1 (MUM1) were evaluated by using a 2 mm core from 104 DLBCL patients for tissue microarray. Positive expression of SIRT1 was seen in 74% (77/104) of patients. In total DLBCL patients, SIRT1 and p53 expression were significantly associated with shorter overall survival (OS) by univariate analysis (P=0.001 and P=0.011, respectively). SIRT1 was also an independent prognostic factor by multivariate analysis (P=0.01). According to the expression patterns of CD10, bcl6, and MUM1, germinal center B cell (GCB) types were represented in 38 cases (37%) and non-GCB types were represented in 66 cases (63%). In the GCB type, only p53 expression was associated with a significantly shorter OS (P=0.032). In the non-GCB type, expression of SIRT1 correlated with shorter OS by univariate analyses (P=0.005) and multivariate analyses (P=0.049). In conclusion, we showed that SIRT1 expression is a clinically significant prognostic indicator for DLBCL patients.
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- 2008
41. Prognostic impact of tumor infiltrating FOXP3 positive regulatory T cells in diffuse large B-cell lymphoma at diagnosis
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Na-Ri Lee, Eun-Kee Song, Ha Na Choi, Kyu Yun Jang, Keun-Sang Kwon, Ju-Hyung Lee, Jae-Yong Kwak, Woo Sung Moon, and Chang-Yeol Yim
- Subjects
Oncology ,Adult ,Male ,Cancer Research ,Pathology ,medicine.medical_specialty ,Regulatory T cell ,Immunology ,chemical and pharmacologic phenomena ,Biochemistry ,T-Lymphocytes, Regulatory ,Immune system ,International Prognostic Index ,Lymphocytes, Tumor-Infiltrating ,Internal medicine ,Biopsy ,medicine ,Humans ,Tumor biopsy ,Survival rate ,Aged ,Retrospective Studies ,Aged, 80 and over ,Tissue microarray ,medicine.diagnostic_test ,business.industry ,Germinal center ,FOXP3 ,hemic and immune systems ,Forkhead Transcription Factors ,Cell Biology ,Hematology ,Middle Aged ,medicine.disease ,Prognosis ,Immunohistochemistry ,Lymphocyte Subsets ,Lymphoma ,Survival Rate ,medicine.anatomical_structure ,Tissue Array Analysis ,Female ,Lymphoma, Large B-Cell, Diffuse ,business ,Diffuse large B-cell lymphoma - Abstract
Tumor-infiltrating immune cells perform a crucial function in host immune reactions against diffuse large B-cell lymphoma (DLBCL). In this study, we have identified a subset of tumor-infiltrating FOXP3-positive regulatory T cells (Tregs) in the initial DLBCL biopsy specimens, and have evaluated their prognostic significance. Ninety six patients with DLBCL were evaluated retrospectively. The pattern of FOXP3 protein expression was evaluated using standard immunohistochemistry in paraffin-embedded tissue samples. Sixty seven of all 96 specimens were stained with antibodies for CD-10, bcl-6 and MUM1 via tissue microarray (TMA) to classify the cases into a germinal center B-cell like (GCB) group and a non-GCB group. The median overall survival (OS) was 28 months. As compared with the others, the patients with higher percentages of FOXP3-positive Tregs on initial tumor biopsy evidenced a significantly longer OS (p = 0.003). Patients classified into the GCB group evidenced a significantly longer OS as compared with the non-GCB group (p = 0.008). When the prognostic factors were evaluated via a multivariate model, the international prognostic index and the percentage of infiltrating FOXP3-positive Tregs in the initial biopsy were identified as independent predictors of OS. In conclusion, the presence of an increased percentage of FOXP3-positive Tregs in DLBCL is predictive of better prognoses.
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- 2008
42. Expression of the serum response factor in hepatocellular carcinoma: Implications for epithelial-mesenchymal transition
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Ha Na Choi, Myoung Ja Chung, Myoung Jae Kang, Dong Geun Lee, Kyu Yun Jang, Byung-Hyun Park, Min Young Park, Woo Sung Moon, Kyung Ryoul Kim, and Ho Sung Park
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Adult ,Male ,Serum Response Factor ,Cancer Research ,Pathology ,medicine.medical_specialty ,Carcinoma, Hepatocellular ,Adolescent ,genetic structures ,Cell ,Vimentin ,Biology ,Epithelium ,Mesoderm ,Cell Line, Tumor ,Serum response factor ,medicine ,Carcinoma ,Humans ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Genes, Immediate-Early ,neoplasms ,Aged ,Retrospective Studies ,Oncogene ,Liver Neoplasms ,Mesenchymal stem cell ,Middle Aged ,Cell cycle ,medicine.disease ,digestive system diseases ,Cell Transformation, Neoplastic ,medicine.anatomical_structure ,Oncology ,embryonic structures ,cardiovascular system ,biology.protein ,Cancer research ,Female - Abstract
The acquisition of a migratory and invasive phenotype by cells of epithelial origin is associated with a gain of mesenchymal characteristics concomitant with a loss of the epithelial phenotype, a phenomenon referred to as epithelial-mesenchymal transition (EMT). Vimentin, a cytoplasmic intermediate filament, is characteristic of mesenchymal cells and is usually not expressed in epithelial cells. Increased expression of vimentin in carcinomas correlates with parameters of malignant potential such as tumor grade and tumor invasion. Serum response factor (SRF) regulates transcription of immediate early genes and triggers proliferation, migration and differentiation in several types of cells. However, the role of SRF in hepatocellular carcinoma (HCC) has not been explored. The aims of this study were to evaluate the expression of SRF and to assess a functional role of SRF in HCC. First, we examined the expression of SRF in 55 human specimens of HCC and four different HCC cell lines, including a sarcomatoid HCC cell line. We also examined the role of SRF in HCC by transfection of an SRF expression plasmid into a HCC cell line. SRF was expressed in 13 of 55 cases of HCC. SRF was predominantly expressed in HCC cells, with intense labeling in the nucleus. No staining was observed in hepatocytes of normal and cirrhotic liver outside the tumor. SRF was significantly up-regulated in high grade HCC, especially in sarcomatoid HCC. Overexpression of SRF in hepatocellular carcinoma cells accelerates migration and invasion with subsequent acquisition of mesenchymal phenotype by expression of a mesenchymal marker (vimentin) and activation of immediate early genes. We propose for the first time that the expression of SRF in HCC cells associated with EMT may play an important role in HCC progression. Thus, functional antagonism of SRF will provide an additional therapeutic approach by controlling tumor cell invasion and metastasis.
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- 2007
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43. Overexpression of discoidin domain receptor 1 increases the migration and invasion of hepatocellular carcinoma cells in association with matrix metalloproteinase
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Beom Tae Kim, Dae Ki Kim, Woo Sung Moon, Ha Na Choi, Kyung Ryoul Kim, Hojin Lee, and Ho Sung Park
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Cancer Research ,Pathology ,medicine.medical_specialty ,Carcinoma, Hepatocellular ,Cell ,Biology ,Transfection ,Receptor tyrosine kinase ,Gentamicin protection assay ,Discoidin Domain Receptor 1 ,Cell Movement ,Cell Line, Tumor ,medicine ,Humans ,Neoplasm Invasiveness ,DDR1 ,Liver Neoplasms ,Receptor Protein-Tyrosine Kinases ,General Medicine ,Cell cycle ,digestive system diseases ,Matrix Metalloproteinases ,Recombinant Proteins ,medicine.anatomical_structure ,Oncology ,Cell culture ,biology.protein ,Cancer research ,Discoidin domain - Abstract
The discoidin domain receptor (DDR) is a class of receptor tyrosine kinases that binds to several collagens. DDR1 is widely expressed in fast-growing invasive tumors of the breast, ovary, esophagus, brain and lung. However, there is little information on the expression of DDR1 in hepatocellular carcinoma (HCC) or its function in migration and invasion. Western blot analysis was performed to determine if four HCC cell lines (HLE, Huh-7, HepG2 and SH-J1) express DDR1. The HLE and Huh-7 cell lines were transfected with two isoforms of DDR1, DDR1a and DDRlb. Immuno-precipitation for DDR1 was then performed. Migration and invasion assays were carried out and the number of migrating cells was counted in 6 randomly selected fields per well under an optical microscope. Zymography was used to determine the level of the matrix metalloproteinase (MMP)-2 and -9 expression. DDR1 was expressed in all four cell lines. In the migration assay, the number of migrating cells was significantly higher in the DDR1a- or DDRlb-overexpressing HLE and Huh-7 cells, particularly after collagen type I stimulation (P
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- 2007
44. A peroxisome proliferator-activated receptor gamma antagonist induces vimentin cleavage and inhibits invasion in high-grade hepatocellular carcinoma
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Kyung Ryoul, Kim, Ha Na, Choi, Ho Jin, Lee, Hyun A, Baek, Ho Sung, Park, Kyu Yun, Jang, Myoung Ja, Chung, and Woo Sung, Moon
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Carcinoma, Hepatocellular ,Pyridines ,Blotting, Western ,Liver Neoplasms ,Cell Growth Processes ,Ligands ,Colony-Forming Units Assay ,Immunoenzyme Techniques ,PPAR gamma ,Rosiglitazone ,Troglitazone ,Cell Movement ,Cell Line, Tumor ,Benzamides ,Cell Adhesion ,Humans ,Hypoglycemic Agents ,Vimentin ,Anilides ,Neoplasm Invasiveness ,Thiazolidinediones ,Chromans - Abstract
Increased expression of vimentin in carcinomas correlates with parameters of malignant potential such as tumor grade and tumor metastasis. Peroxisome proliferator-activated receptor gamma (PPARgamma) has been intensively evaluated as a potential target for the inhibition of cell growth and metastasis in cancer cells. In the present study, we examined whether PPARgamma is a possible target molecule for the prevention of cell growth and invasion by treatment with agonists (troglitazone, rosiglitazone) and antagonists (T0070907, GW9662) in four different hepatocellular carcinoma (HCC) cell lines. We also evaluated the effects of the PPARgamma agonists and antagonists on tumor cell migration and invasion. The expression level of PPARgamma protein was higher in the sarcomatoid SH-J1 and poorly differentiated HLE cell lines than that in the well-differentiated HCC cell lines (HepG2 and Huh-7). Expression of vimentin was high in the SH-J1 HCC cell line and minimally detected in the HLE cell line. Treatment with low doses of the PPARgamma antagonists inhibited cell growth and colony formation of all four of the HCC cell lines. Vimentin in the high-grade HCC cells was cleaved by the treatment with the PPARgamma antagonists. Furthermore, treatment with the PPARgamma antagonists also strongly inhibited migration and invasion of the SH-J1 and HLE cells. However, treatment with low doses of the agonists had no effect on vimentin expression, migration, and invasion of the high-grade HCC cells but cell growth was inhibited by treatment with high concentrations of the agonists. Our results indicate that treatment with a PPARgamma antagonist may prevent cell growth and invasion of high-grade HCC cells. Our findings also suggest that PPARgamma antagonists inhibit cell growth and invasion through vimentin disarrangement in high-grade HCC.
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- 2007
45. Prosthetic Valve Endocarditis caused by HACEK Organisms: a Case Report and Systematic Review of the Literature.
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Ha Na Choi, Ki-Ho Park, Soyoung Park, Jae-Min Kim, Hyun Joon Kang, Jae Hun Park, and Mi Suk Lee
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- *
COMPLICATIONS of prosthesis , *DIAGNOSIS of endocarditis , *TREATMENT of endocarditis , *ENDOCARDITIS prevention , *RIBOSOMAL RNA genetics - Abstract
HACEK is a rare cause of prosthetic valve endocarditis (PVE). We describe 42-year-old male patient who presented with Aggregatibacter aphrophilus PVE and cerebral infarct. A aphrophilus was isolated from his blood cultures as the sole pathogen, which was confirmed by subsequent 16S rRNA sequencing. He was treated with valve replacement surgery and an 8 week course of pathogen-directed antibiotic therapy and followed for 20 months with out recurrence. [ABSTRACT FROM AUTHOR]
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- 2017
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46. Abstract 10: Characterization of CD45-/CD31+/CD105+ circulating cells in the peripheral blood of patients with gynecological malignancies
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Ji Young Choi, Ho-Jeong Lee, Sun Jin Kim, Haengseok Song, Tae Jin Kim, Hyun-Kyung Yu, Lee S.H. Yi, Ahn Jinhyung, Jang-Seong Kim, Hyun-Jeong Seok, Eun-Jeong Jeong, Ha-Na Choi, and Ki Heon Lee
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CD31 ,Cancer Research ,Pathology ,medicine.medical_specialty ,medicine.diagnostic_test ,Angiogenesis ,CD68 ,business.industry ,CD14 ,Cancer ,Endoglin ,medicine.disease ,Flow cytometry ,Oncology ,cardiovascular system ,medicine ,Cancer research ,CD146 ,business - Abstract
Purpose: Circulating endothelial cells (CECs) have been widely used as a prognostic biomarker and regarded as a promising strategy for monitoring the response to treatment in several cancers. However, the presence and biological roles of CECs have remained controversial for decades because technical standards for the identification and quantification of CECs have not been established. Here, we hypothesized that CECs detected by flow cytometry might be monocytes rather than endothelial cells. Experimental Design: The frequency of representative CEC subsets (i.e., CD45-/CD31+, CD45-/CD31+/CD146+, CD45-/CD31+/CD105+) was analyzed in the peripheral blood of gynecological cancer patients (n=56) and healthy volunteers (n=44). CD45-/CD31+ cells, which are components of CECs, were isolated and the expression of various markers (CD146, CD105, vWF, and CD144 for endothelial cells; CD68 and CD14 for monocytes) was examined by immunocytochemistry. Results: CD45-/CD31+/CD105+ cells were significantly increased in the peripheral blood of cancer patients whereas evaluation of CD45/CD31+/CD146+ cells was not possible both in cancer patients and healthy controls due to the limited resolution of the flow cytometry. Immunocytochemistry analyses showed that these CD45-/CD31+/CD105+ cells did not express vWF and CD146 but rather CD144. Furthermore, CD45-/CD31+/CD105+ cells uniformly expressed the monocyte-specific markers CD14 and CD68. These results suggest that D45/CD31+/CD105+ cells carry the characteristics of monocytes rather than endothelial cells. Conclusions: Our data indicate that CD45-/CD31+/CD105+ circulating cells, which are significantly increased in the peripheral blood of gynecological cancer patients, are monocytes rather than endothelial cells. Further investigation is required to determine the biological significance of their presence and function in relation with angiogenesis. Citation Format: Hyun-Kyung Yu, Ho-Jeong Lee, Ha-Na Choi, Jin-Hyung Ahn, Ji-Young Choi, Eun-Jeong Jeong, Hyun-Jeong Seok, Haengseok Song, Ki-Heon Lee, Lee S.H. Yi, Sun Jin Kim, Tae Jin Kim, Jang-Seong Kim. Characterization of CD45-/CD31+/CD105+ circulating cells in the peripheral blood of patients with gynecological malignancies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 10. doi:10.1158/1538-7445.AM2014-10
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- 2014
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47. Effect of Nano-Encapsulated Corrosion Inhibitors on Self-Healing Corrosion Protection of Steel Sheets
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Ha Na Choi, Jong Sang Kim, and Jong Myung Park
- Abstract
A nano-encapsulation system of organic corrosion inhibitors has been designed, which is capable of improving the self-healing corrosion protection without degrading the barrier protection of the coating layers. Core-shell nanoparticles loaded with six types of amine corrosion inhibitors such as ethanolamine, 5-amino-1-pentanol, diethanolamine, triethanolamine, propylamine and dipropylamine, were synthesized by multi-stage emulsion polymerization. Amines were successfully encapsulated into nanocapsules by reacting with carboxylic acid in core and shell polymer during alkalization swelling process. Water-soluble amines were effectively introduced in nanocapsules, and the basicity was the most predominant parameter for amine encapsulation. In alkaline condition, the encapsulated amines were generally well released and the release of the encapsulated amines was pH dependent regardless of the exposure time. In addition, the molecular structure and aqueous solubility were critical factors in the release behaviors. Linear amines and highly water-soluble amines were more easily released to the environments from inside capsules than branched and water-insoluble ones. The nanocapsules were incorporated into the coating resin and were coated on cold-rolled steel sheets to investigate corrosion protection efficiencies. The corrosion inhibitive efficiencies of the nanocapsule-containing coating layers were evaluated by semi-immersion tests and electrochemical tests, electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET). The organic coatings with inhibitor-loading nanocapsules showed better corrosion performance than the organic coating with inhibitor-free nanocapsules. Among six amines used in this study, 5-amino-1-pentanol, diethanolamine and triethanolamine exhibited self-healing anti-corrosion performance with recovering coating resistance. The coating resistance of the coating film gradually decreased and then increased via the self-healing corrosion protection of amines release from the nanocapsules. On the other hand, ethanolamine, propylamine and dipropylamine exhibited a rapid drop in the coating resistance, and the resistance continued to decrease without self-recovery. The inhibition efficiencies of encapsulated amines were affected by both intrinsic inhibition activities of amine and encapsulation/release behaviors.
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- 2014
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48. Dental implant bottom-up cost analysis
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Ho Sung Shin, Ha Na Choi, and Min Young Kim
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business.industry ,medicine.medical_treatment ,Cost analysis ,Medicine ,Dentistry ,business ,Dental implant - Abstract
연구 목적: 본 연구의 목적은 가장 최근에 수행된 치과의원의 경영 분석 자료를 바탕으로 상향식 방법을 적용하여 임플란트 원가를 산정하는데 있다. 연구 재료 및 방법: 본 연구에서는 진료행위 각각에 소요되는 직간접 비용을 모두 합산하는 상향식 방식으로 산출하였다. 상향식 원가계산의 경우 총원가는 인건비, 재료비, 관리비, 의료사고비용, 투자자본의 기회비용 등으로 구성이 된다. 이를 임플란트 원가 구성요소로 구분하면 인건비, 기공료, 재료비, 감가상각비 등의 직접비용과 관리운영비를 포함하는 간접비용, 치과의원 투자분에 대한 기회비용으로 구성된다. 결과: 상부보철물의 종류에 따라 금속관일 경우 1,449천원, 도재관일 경우 1,583천원, 오버덴쳐의 경우 2,471천원으로 산정되었다. 임플란트 원가는 인건비, 재료비, 관리비, 기타비용으로 나누어지는데 총 원가 중 인건비가 차지하는 비율은 50%, 재료비 33%, 관리비 15%, 기타비용2%로 나타났다. 이를 직접비, 간접비, 투자비용으로 구분하면 상부 보철물이 금속관일 경우 각각 원가의 83%, 15%, 2%를 차지한다. 결론: 전체 원가 중 인건비가 73만원(약 50%)으로 가장 많은 비중을 차지한다. 상향식 원가계산 결과 관행수가에 근접하게 나타났는데 금속관의 경우 145만원, 도재관일 경우 158만원 추계되었다. 【Purpose: The purpose of this study was to estimate the cost of dental implant using the bottom-up approach with the current data from dental clinics. Materials and methods: In this study, direct and indirect costs required for each treatment were calculated using the bottom-up approach. In the bottom-up costing, the average monthly total cost of dental clinic includes labor and material costs, administrative expenses, medical malpractice costs, and opportunity costs of invested capital. For the dental implant cost components, those include direct costs (labor costs, laboratory costs, material costs, depreciation or other operating costs), indirect costs (administrative costs), and the opportunity costs of investment for dental clinic. Results: Dental implant costs of metal crown, porcelain crown and over-denture were 1,449,000 won, 1,583,000 won, and 2,471,000 won respectively. The proportion of cost components was as follows. The labor cost were 50%, and material, administrative and other cost were 33%, 15% and 2%, respectively. For direct, indirect and investment cost, the ratio were 83%, 15% and 2%, respectively. Conclusion: The labor costs were evaluated to comprise largest proportion (about 50%, 730,000 won). Dental implant cost using Bottom-up costing was 1,450,000 won for metal crown and 1,580,000 won for porcelain crown.】
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- 2014
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49. Serum response factor enhances liver metastasis of colorectal carcinoma via alteration of the E-cadherin/β-catenin complex
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Myoung Ja Chung, Ji Hyun Lee, Woo Sung Moon, Kyung Ryoul Kim, Hee Chul Yu, Ho Sung Park, Kyu Yun Jang, Ha Na Choi, and Si Eun Hwang
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Cancer Research ,Beta-catenin ,biology ,Deleted in Colorectal Cancer ,Colorectal cancer ,business.industry ,Cancer ,General Medicine ,medicine.disease ,Metastatic carcinoma ,Metastasis ,Oncology ,Tumor progression ,Serum response factor ,Cancer research ,medicine ,biology.protein ,business - Abstract
Serum response factor (SRF) is a transcription factor that controls cell growth, differentiation, and tumor progression as well as muscle development and function. Reduced expression of cell adhesion molecules has been reported to be associated with tumor metastasis. The aim of this study was to evaluate the expression and a role of SRF in liver metastasis of primary colorectal carcinomas. We examined the expression of SRF, E-cadherin, and beta-catenin by the use of immunochemical staining in 43 cases as a set of primary colorectal carcinomas and liver metastases. We also examined the role of SRF in colorectal carcinoma by overexpression of SRF in a colon cancer cell line. In metastatic carcinoma surgical samples, there was a marked increased expression of SRF as compared to expression in primary colorectal carcinoma surgical samples (P
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- 1994
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50. Synthesis and Potential Application of Nanoalloys by Using Molecular Precursors
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Ha-Na Choi, Sang Hyun Lee, Sun-Sook Lee, Taek-Mo Chung, and Chang G. Kim
- Abstract
not Available.
- Published
- 2011
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