Clioquinol, a Cu(II)/Zn(II) Chelator, Inhibits Both Ubiquitination and Asparagine Hydroxylation of Hypoxia-inducible Factor-1α, Leading to Expression of Vascular Endothelial Growth Factor and Erythropoietin in Normoxic Cells

Choi, Su Mi,Choi, Kyung-Ok,Park, Young-Kwon,Cho, Hyunju,Yang, Eun Gyeong,Park, Hyunsung American Society for Biochemistry and Molecular Bi 2006 The Journal of biological chemistry Vol.281 No.45

COMPUTERIZED QUANTIFICATION OF TISSUE VASCULARIZATION

HyunJu Choi,TaeYun Kim,HaeGil Hwang,HeungKook Choi 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

This paper presents a computerized image analysis method for quantifying tissue vascularization. The segmentation task was based on a supervised learning scheme. First, 12 color features (RGB, HSI, I₁I₂I₃, and L<SUP>*</SUP>a<SUP>*</SUP>b<SUP>*</SUP>) were extracted from a training set. The feature selection procedure selected I₂L<SUP>*</SUP>S features as the best color feature vector. Then, we segmented microvessels using the discriminant function made using the minimum error rate classification rule of Bayesian decision theory. In the quantification step, after applying a connected component-labeling algorithm, microvessels with discontinuities were connected and touching microvessels were separated. We tested the proposed method on 23 images. The result was evaluated by comparing it with manual quantification of the same images. The comparison revealed that our computerized microvessel counting was highly correlated with manual counting by an expert (r = 0.95754). The association between the number of microvessels after the initial segmentation and manual quantification was also assessed using Pearson's correlation coefficient (r = 0.71187). The results indicate that our method is better than the conventional computerized image analysis methods.

The Role of <i>Arabidopsis</i> ABCG9 and ABCG31 ATP Binding Cassette Transporters in Pollen Fitness and the Deposition of Steryl Glycosides on the Pollen Coat

Choi, Hyunju,Ohyama, Kiyoshi,Kim, Yu-Young,Jin, Jun-Young,Lee, Saet Buyl,Yamaoka, Yasuyo,Muranaka, Toshiya,Suh, Mi Chung,Fujioka, Shozo,Lee, Youngsook American Society of Plant Biologists 2014 The Plant cell Vol.26 No.1

<P>This work identified two ABC transporters important for normal pollen coat deposition and, thus, critical for pollen fitness. The transporters are probably involved in the transfer of pollen coat material from maternal tissues to the pollen surface.</P>

Rapid drug susceptibility test of Mycobacterium tuberculosis using microscopic time-lapse imaging in an agarose matrix

Choi, Jungil,Yoo, Jungheon,Kim, Ki-jung,Kim, Eun-Geun,Park, Kyung Ock,Kim, Hyejin,Kim, Haeun,Jung, Hyunju,Kim, Taeyoung,Choi, Myungjin,Kim, Hee Chan,Ryoo, Sungweon,Jung, Yong-Gyun,Kwon, Sunghoon Springer-Verlag 2016 Applied microbiology and biotechnology Vol.100 No.5

<P>Tuberculosis (TB) is a major global health problem, and multi-drug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) are spreading throughout the world. However, conventional drug susceptibility test (DST) methods, which rely on the detection of the colony formation on a solid medium, require 1-2 months to the result. A rapid and accurate DST is necessary to identify patients with drug-resistant TB and treat them with appropriate drugs. Here, we used microscopic imaging of Mycobacterium tuberculosis (MTB) immobilized in an agarose matrix for a rapid DST. The agarose matrix, which was molded in a microfluidic chip, was inoculated with MTB, and TB drugs in liquid culture medium diffused throughout the agarose to reach the MTB immobilized in the agarose matrix. After the responses of MTB to drugs were tracked with an automated microscopic system, an image-processing program automatically determined the susceptibility and resistance of MTB to specific doses of TB drugs. The automatic DST system was able to assess the drug susceptibility of various drug-resistant clinical TB strains within 9 days with an accuracy comparable to that of conventional method. Our rapid DST method based on microscopic time-lapse imaging greatly reduces the time required for a DST and can be used to rapidly and accurately treat TB patients.</P>

Creativity-Character Element Analysis by Organic Fusion of Creativity and Character

Choi, Younchul,Choi, Hyunju,Kim, Kyungchul,Cho, Bookyung Global Vision School Publication 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.12

Exploring the Relationship between Creativity and Character based on Online Text Data Analysis

Hyunju Choi,Younchul Choi,Kyungchul Kim 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.10

The goal of his research was to analyze the meaning of creativity and character based on online text data analysis and identify the relationship between the two. To perform research, online text data was collected for analysis. The collected data was cleaned and then used to analyze the frequency of keyword text, network density, and centrality. The research concluded that both creativity and character have important socio-cultural significances on education. Also, the research showed that, while people tend to include character when they consider creativity, they rarely include creativity when they consider character. It is hoped that the results of this research will contribute to developing ways to integrate creativity and character in education.

Analysis of Critical COVID-19 Cases Among Children in Korea

Hyunju Lee,Sujin Choi,Ji Young Park,Dae Sun Jo,Ui Yoon Choi,Hea Yon Lee,Yun Tae Jung,In Hyuk Chung,최영준,Jin Yong Kim,Young-Joon Park,Eun Hwa Choi 대한의학회 2022 Journal of Korean medical science Vol.37 No.1

Background: Coronavirus disease 2019 (COVID-19) is generally asymptomatic or mild in otherwise healthy children, however, severe cases may occur. In this study, we report the clinical characteristics of children classified as critical COVID-19 in Korea to provide further insights into risk factors and management in children. Methods: This study was a retrospective case series of children < 18 years of age classified as critical COVID-19. Cases were identified by the Korea Disease Control and Prevention Agency surveillance system and medical records were reviewed. Critical COVID-19 was defined as cases with severe illness requiring noninvasive (high flow nasal cannula, continuous positive airway pressure, or bilevel positive airway pressure) or invasive mechanical ventilation, extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), between January 20, 2020 and October 7, 2021. Results: Among 39,146 cases diagnosed with COVID-19 in subjects < 18 years of age, eight cases (0.02%) were identified as critical COVID-19. The median age was 13 years (range 10 month–17 years) and male-to-female ratio was 1:1. Three children had underlying diseases; one child has asthma and major depressive disorder, one child had LennoxGastaut syndrome and one child had mental retardation and was newly diagnosed with type 2 diabetes mellitus with the diagnosis of COVID-19. Among the eight children, seven were obese (body mass index range [BMI] median 29.3, range 25.9–38.2, weight-for-length > 97% for infant) and one was overweight (BMI 21.3). All patients had fever, six patients had dyspnea or cough and other accompanied symptoms included sore throat, headache, lethargy and myalgia. Radiologic findings showed pneumonia within 1–8 days after symptom onset. Pneumonia progressed in these children for 2–6 days and was improved within 5–32 days after diagnosis. Among the eight critical cases, remdesivir was administered in six cases. Steroids were provided for all cases. Inotropics were administered in one case. Six cases were treated with noninvasive mechanical ventilator and three required mechanical ventilator. One case required ECMO due to acute respiratory distress syndrome. All cases were admitted to the intensive care unit and admission period ranged from 9–39 days. Among all critical COVID-19 cases < 18 years of age, there were no fatal cases. Conclusion: To develop appropriate policies for children in the COVID-19 pandemic, it is important to monitor and assess the clinical burden in this population.

SARS-CoV-2-Naïve Korean Children and Adolescents Hospitalized With COVID-19 in 2021

Choi Youn Young,Choi Soo-Han,Choi Jae Hong,Kim Dong Hyun,Lee Joon Kee,Eun Byung Wook,Lee Hyunju,Kim Ye Kyung,Ahn Bin,Song Seung Ha,Yun Ki Wook 대한의학회 2022 Journal of Korean medical science Vol.37 No.42

Background: The risk of severe outcomes with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delta variant remains low in children and adolescents, but less is known about its effect on the SARS-CoV-2-naïve population. This study evaluated clinical manifestations and risk factors for moderate-to-critical coronavirus disease 2019 (COVID-19) in mostly SARS-CoV-2-naïve children and adolescents in 2021. Methods: This multicenter retrospective study included patients aged 0–18 years who were hospitalized with COVID-19 at 8 referring hospitals in South Korea during the predeltapredominant and delta-predominant periods in 2021. Each case was labeled as either hospitalization with medical needs or for isolation. Severity was categorized as mild, moderate, severe, or critical with regard to pneumonia presence and illness severity. Results: Among 753 cases, most (99.5%) had no prior history of COVID-19 or vaccination against COVID-19. The proportions of hospitalization with medical needs (3.5% vs. 19.7%), moderate illness (0.9% vs. 4.0%), and severe/critical illness (0.8% vs. 5.3%) increased during delta predominance. The risk of moderate-to-critical COVID-19 among hospitalizations with medical needs was higher among patients aged 12–18 years (adjusted odds ratio [aOR], 4.1; 95% confidence interval [CI], 1.5–11.8) and with obesity (aOR, 6.9; 95% CI, 2.4–19.6) but not among patients infected during delta predominance. However, children with obesity experienced more severe COVID-19 during delta predominance (aOR, 6.1; 95% CI, 1.2–29.6). Conclusion: Despite its similar severity among most SARS-CoV-2-naïve children and adolescents, the delta variant may affect COVID-19 severity in those with high-risk underlying medical conditions. Underlying conditions, particularly obesity, may cause severe COVID-19 in children and adolescents, warranting strong consideration for vaccinating high-risk children.

SURFACE TEXTURE ANALYSIS FOR 3D SHAPE ESTIMATION OF CELL NUCLEI IN NUCLEAR GRADING

Hyunju Choi,Taeyun Kim,Uno Tak,Haegil Hwang,Heungkook Choi 한국멀티미디어학회 2007 한국멀티미디어학회 국제학술대회 Vol.2007 No.-

Objective: To find surface texture descriptors for estimating 3D shape of cell nuclei in nuclear grading of renal cell carcinoma and evaluate the feasibility of such quantitative analysis. Methods: After surface rendering, the surfaces of 3D cell nuclei consist of triangle meshes. Our method is based on the relationship between the normal vectors of adjacent triangles. In order to derive the relationship of them, we computed angles between adjacent normal vectors and made an angle feature histogram. Based on this feature histogram, we defined surface texture descriptors and evaluated their significance in nuclear grading. Results and Conclusion: We found a statistically significant correlation between nuclear grade and surface texture descriptors of cell nuclei. It means that surface texture descriptors can be important diagnostic factors to improve the accuracy of grading renal cell carcinoma.

Antimicrobial Resistance and Molecular Analysis of Staphylococcus aureus in Staphylococcal Scalded Skin Syndrome among Children in Korea

Choi Jae Hong,Lee Hyunju,Choi Eun Hwa 대한의학회 2021 Journal of Korean medical science Vol.36 No.3

Background: Staphylococcal scalded skin syndrome (SSSS) is a skin disease characterized by blistering and desquamation caused by exfoliative toxins (ETs) of Staphylococcus aureus (S. aureus). Although many countries show predominance of methicillin-susceptible S. aureus (MSSA), cases of methicillin-resistant S. aureus (MRSA) have been reported. Methods: Twenty-six children aged <15 years diagnosed with SSSS from January 2010 to December 2017 from three hospitals were included. S. aureus isolates from cases were analyzed for multilocus sequence types and ETs. Medical records were reviewed for clinical characteristics, treatment, and antimicrobial susceptibility patterns of S. aureus. Results: Among the 26 cases, mean age was 2.3 years. According to skin manifestations patients were classified as generalized (n = 10, 38.5%), intermediate (n = 11, 42.3%), and abortive (n = 5, 19.2%). Among all cases, 96.2% (25/26) were due to MRSA and the macrolide- resistance rate was 92.3% (24/26). ST89 (n = 21, 80.8%) was the most prevalent clone, followed by single clones of ST1, ST5, ST72, ST121, and ST1507. The eta gene was detected in one (3.8%) isolate which was MSSA. The etb gene was detected in 14 (53.8%) isolates, all of which were ST89. Nafcillin or first-generation cephalosporin was most commonly prescribed (n=20, 76.9%). Vancomycin was administered in four patients (15.4%) and clindamycin in nine patients (34.6%). Among MRSA cases, there was no difference in duration of treatment when comparing the use of antimicrobials to which the causative bacteria were susceptible or non-susceptible (9.75 vs. 8.07 days, P > 0.05). Conclusion: S. aureus isolated from children with SSSS in Korea demonstrated a high prevalence of methicillin-resistant ST89 clones that harbored the etb gene. The predominance of MRSA suggests that antibiotics to which MRSA are susceptible may be considered for empirical antibiotic treatment in children with SSSS in Korea. Further studies on the role and effectiveness of systemic antibiotics in SSSS are warranted.