1.Energy Metabolism in Human Pluripotent Stem and Differentiated Cells Compared Using a Seahorse XF96 Extracellular Flux Analyzer
Hyun Kyu KIM ; Yena SONG ; Minji KYE ; Byeongho YU ; Sang Beom PARK ; Ji Hyeon KIM ; Sung-Hwan MOON ; Hyungkyu CHOI ; Jong-Seok MOON ; Jae Sang OH ; Man Ryul LEE
International Journal of Stem Cells 2024;17(2):194-203
Evaluating cell metabolism is crucial during pluripotent stem cell (PSC) differentiation and somatic cell reprogramming as it affects cell fate. As cultured stem cells are heterogeneous, a comparative analysis of relative metabolism using existing metabolic analysis methods is difficult, resulting in inaccuracies. In this study, we measured human PSC basal metabolic levels using a Seahorse analyzer. We used fibroblasts, human induced PSCs, and human embryonic stem cells to monitor changes in basal metabolic levels according to cell number and determine the number of cells suitable for analysis. We evaluated normalization methods using glucose and selected the most suitable for the metabolic analysis of heterogeneous PSCs during the reprogramming stage. The response of fibroblasts to glucose increased with starvation time, with oxygen consumption rate and extracellular acidification rate responding most effectively to glucose 4 hours after starvation and declining after 5 hours of starvation. Fibroblasts and PSCs achieved appropriate responses to glucose without damaging their metabolism 2∼4 and 2∼3 hours after starvation, respectively. We developed a novel method for comparing basal metabolic rates of fibroblasts and PSCs, focusing on quantitative analysis of glycolysis and oxidative phosphorylation using glucose without enzyme inhibitors. This protocol enables efficient comparison of energy metabolism among cell types, including undifferentiated PSCs, differentiated cells, and cells undergoing cellular reprogramming, and addresses critical issues, such as differences in basal metabolic levels and sensitivity to normalization, providing valuable insights into cellular energetics.
2.Three pediatric patients with primary hyperparathyroidism caused by parathyroid adenoma
Arum OH ; Yena LEE ; Han-Wook YOO ; Jin-Ho CHOI
Annals of Pediatric Endocrinology & Metabolism 2022;27(2):142-147
Primary hyperparathyroidism (PHPT) is a hypercalcemia disorder with inappropriately normal or increased serum parathyroid hormone (PTH) levels resulting from excessive secretion of PTH from one or more of the parathyroid glands. PHPT is uncommon in infants and children, with an estimated incidence of 2–5 cases per 100,000 persons. Patients with PHPT usually present with bone pain, urolithiasis, or nephrolithiasis, as well as nonspecific symptoms such as fatigue and weakness. Asymptomatic hypercalcemia may also be detected incidentally. Only a few cases of pediatric PHPT have been reported in Korea. We present three patients (a 9-year-old girl, a 14-year-old boy, and a 14-year-old girl) with PHPT who manifested variable clinical features of hypercalcemia. The first and second patients each had a parathyroid adenoma and presented with abdominal pain caused by pancreatitis and a ureter stone, respectively. The third patient had an ectopic mediastinal parathyroid adenoma and presented with gait disturbance and weakness of the lower extremities. All of the patients underwent surgical resection of parathyroid adenoma, and their serum calcium levels subsequently normalized without medication.
3.Liver transplantation of a patient with extreme thrombocytopenia - A case report -
Yena OH ; Seung Yeon YOO ; Gyu-Seong CHOI ; Gaabsoo KIM
Anesthesia and Pain Medicine 2021;16(3):279-283
Background:
Patients with chronic liver disease (CLD) planned for liver transplantation (LT) often show severe thrombocytopenia, but there is a lack of evidence in deciding the threshold for prophylactic platelet transfusion.Case: A 47-year-old women with acute liver failure was referred for LT. Despite daily transfusion of platelets, platelet counts remained under 10,000/µl. During LT, 2 units of single donor platelets (SDP) were transfused. Although platelet counts remained extremely low (3,000–4,000/µl) no diffuse oozing was observed and the blood loss was 860 ml. Postoperatively, there was no sign of active bleeding or oozing, and the patient received only 1 unit SDP transfusion.
Conclusions
CLD patients may have severe thrombocytopenia. However, primary hemostasis may not be significantly hindered due to the existence of rebalanced hemostasis. Prophylactic platelet transfusion in these patients should not be decided based on platelet counts only, but also take other coagulation tests and clinical signs into consideration.
4.Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice
Minha KIM ; So-Dam KIM ; Kyoung In KIM ; Eun Hae JEON ; Min Gee KIM ; Yu-Ree LIM ; Enkhmaa LKHAGVA-YONDON ; Yena OH ; Kwangmin NA ; Young Cheul CHUNG ; Byung Kwan JIN ; Yun Seon SONG ; Myung-Shin JEON
Experimental Neurobiology 2021;30(2):155-169
Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.
5.Dynamics of T Lymphocyte between the Periphery and the Brain from the Acute to the Chronic Phase Following Ischemic Stroke in Mice
Minha KIM ; So-Dam KIM ; Kyoung In KIM ; Eun Hae JEON ; Min Gee KIM ; Yu-Ree LIM ; Enkhmaa LKHAGVA-YONDON ; Yena OH ; Kwangmin NA ; Young Cheul CHUNG ; Byung Kwan JIN ; Yun Seon SONG ; Myung-Shin JEON
Experimental Neurobiology 2021;30(2):155-169
Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.
6.Organizing an in-class hackathon to correct PDF-to-text conversion errors of Genomics & Informatics 1.0
Sunho KIM ; Royoung KIM ; Ryeo-Gyeong KIM ; Enjin KO ; Han-Su KIM ; Jihye SHIN ; Daeun CHO ; Yurhee JIN ; Soyeon BAE ; Ye Won JO ; San Ah JEONG ; Yena KIM ; Seoyeon AHN ; Bomi JANG ; Jiheyon SEONG ; Yujin LEE ; Si Eun SEO ; Yujin KIM ; Ha-Jeong KIM ; Hyeji KIM ; Hye-Lynn SUNG ; Hyoyoung LHO ; Jaywon KOO ; Jion CHU ; Juwon LIM ; Youngju KIM ; Kyungyeon LEE ; Yuri LIM ; Meongeun KIM ; Seonjeong HWANG ; Shinhye HAN ; Sohyeun BAE ; Sua KIM ; Suhyeon YOO ; Yeonjeong SEO ; Yerim SHIN ; Yonsoo KIM ; You-Jung KO ; Jihee BAEK ; Hyejin HYUN ; Hyemin CHOI ; Ji-Hye OH ; Da-Young KIM ; Hee-Jo NAM ; Hyun-Seok PARK
Genomics & Informatics 2020;18(3):e33-
This paper describes a community effort to improve earlier versions of the full-text corpus of Genomics & Informatics by semi-automatically detecting and correcting PDF-to-text conversion errors and optical character recognition errors during the first hackathon of Genomics & Informatics Annotation Hackathon (GIAH) event. Extracting text from multi-column biomedical documents such as Genomics & Informatics is known to be notoriously difficult. The hackathon was piloted as part of a coding competition of the ELTEC College of Engineering at Ewha Womans University in order to enable researchers and students to create or annotate their own versions of the Genomics & Informatics corpus, to gain and create knowledge about corpus linguistics, and simultaneously to acquire tangible and transferable skills. The proposed projects during the hackathon harness an internal database containing different versions of the corpus and annotations.
7.Organizing an in-class hackathon to correct PDF-to-text conversion errors of Genomics & Informatics 1.0
Sunho KIM ; Royoung KIM ; Ryeo-Gyeong KIM ; Enjin KO ; Han-Su KIM ; Jihye SHIN ; Daeun CHO ; Yurhee JIN ; Soyeon BAE ; Ye Won JO ; San Ah JEONG ; Yena KIM ; Seoyeon AHN ; Bomi JANG ; Jiheyon SEONG ; Yujin LEE ; Si Eun SEO ; Yujin KIM ; Ha-Jeong KIM ; Hyeji KIM ; Hye-Lynn SUNG ; Hyoyoung LHO ; Jaywon KOO ; Jion CHU ; Juwon LIM ; Youngju KIM ; Kyungyeon LEE ; Yuri LIM ; Meongeun KIM ; Seonjeong HWANG ; Shinhye HAN ; Sohyeun BAE ; Sua KIM ; Suhyeon YOO ; Yeonjeong SEO ; Yerim SHIN ; Yonsoo KIM ; You-Jung KO ; Jihee BAEK ; Hyejin HYUN ; Hyemin CHOI ; Ji-Hye OH ; Da-Young KIM ; Hee-Jo NAM ; Hyun-Seok PARK
Genomics & Informatics 2020;18(3):e33-
This paper describes a community effort to improve earlier versions of the full-text corpus of Genomics & Informatics by semi-automatically detecting and correcting PDF-to-text conversion errors and optical character recognition errors during the first hackathon of Genomics & Informatics Annotation Hackathon (GIAH) event. Extracting text from multi-column biomedical documents such as Genomics & Informatics is known to be notoriously difficult. The hackathon was piloted as part of a coding competition of the ELTEC College of Engineering at Ewha Womans University in order to enable researchers and students to create or annotate their own versions of the Genomics & Informatics corpus, to gain and create knowledge about corpus linguistics, and simultaneously to acquire tangible and transferable skills. The proposed projects during the hackathon harness an internal database containing different versions of the corpus and annotations.
8.Development of Tigecycline Resistance in Carbapenemase-Producing Klebsiella pneumoniae Sequence Type 147 via AcrAB Overproduction Mediated by Replacement of the ramA Promoter
Eun Jeong YOON ; Yena OH ; Seok Hoon JEONG
Annals of Laboratory Medicine 2020;40(1):15-20
BACKGROUND:
Carbapenem-resistant K. pneumoniae 2297, isolated from a patient treated with tigecycline for pneumonia, developed tigecycline resistance, in contrast to carbapenem-resistant isolate 1215, which was collected four months prior to the 2297 isolate. Mechanisms underlying tigecycline resistance were elucidated for the clinical isolates.
METHODS:
The tigecycline minimum inhibitory concentration (MIC) was determined using the broth microdilution method, with or without phenylalanine-arginine β-naphthylamide (PABN), and whole-genome sequencing was carried out by single-molecule real-time sequencing. The expression levels of the genes acrA, oqxA, ramA, rarA, and rpoB were determined by reverse-transcription quantitative PCR.
RESULTS:
Both isolates presented identical antibiograms, except for tigecycline, which showed an MIC of 0.5 mg/L in 1215 and 2 mg/L in 2297. The addition of PABN to tigecycline-resistant 2297 caused a four-fold decrease in the tigecycline MIC to 0.5 mg/L, although acrA expression (encoding the AcrAB efflux pump) was upregulated by 2.5 fold and ramA expression (encoding the pump activator RamA) was upregulated by 1.4 fold. We identified a 6,096-bp fragment insertion flanking direct TATAT repeats that disrupted the romA gene located upstream of ramA in the chromosome of K. pneumoniae 2297; the insertion led the ramA gene promoter replacement resulting in stronger activation of the gene.
CONCLUSIONS
The K. pneumoniae isolate developed tigecycline resistance during tigecycline treatment. It was related to the overexpression of the AcrAB resistance-nodulation-cell division efflux system due to promoter replacement.
9.Efficacy and safety of parenteral vitamin D therapy in infants and children with vitamin D deficiency caused by intestinal malabsorption
Sae Bit YU ; Yena LEE ; Arum OH ; Han-Wook YOO ; Jin-Ho CHOI
Annals of Pediatric Endocrinology & Metabolism 2020;25(2):112-117
Purpose:
Oral supplementation of vitamin D can be inefficient in patients with vitamin D deficiency caused by intestinal malabsorption. This study investigated the efficacy and safety of parenteral vitamin D supplementation in infants and children with vitamin D deficiency caused by intestinal malabsorption.
Methods:
This study included 11 patients with vitamin D deficiency who were unresponsive to oral vitamin D or were unable to try oral vitamin D therapy due to underlying conditions. All patients were treated with weekly intramuscular injection of cholecalciferol 50,000 IU. Radiological findings and biochemical parameters including serum calcium, phosphorus, alkaline phosphatase, 25-hydroxyvitamin D3 (25(OH)D3), and parathyroid hormone levels were reviewed retrospectively.
Results:
Underlying diseases included small bowel atresia (n=3), necrotizing enterocolitis (n=3), congenital megacolon (n=2), chronic intestinal pseudoobstruction (n=1), congenital mesenteric band (n=1), and Crohn disease (n=1). Three patients exhibited rickets on X-ray findings. The mean duration of treatment was 4.8±2.9 weeks. The alkaline phosphatase levels were decreased from 710±650 IU/L to 442±284 IU/L (P=0.143). The 25(OH)D3 level was increased from 6.0±3.4 ng/mL to 50.4±28.8 ng/mL (P=0.008) after 3 months. Two patients with rickets showed improved radiologic findings after parenteral treatment.
Conclusion
Parenteral vitamin D therapy was effective and safe in patients with vitamin D deficiency caused by intestinal malabsorption. Long-term follow-up is needed to establish the efficacy of parenteral vitamin D therapy in a large number of patients.
10.Clinical, endocrinological, and molecular features of four Korean cases of cytochrome P450 oxidoreductase deficiency
Yena LEE ; Jin-Ho CHOI ; Arum OH ; Gu-Hwan KIM ; Sook-Hyun PARK ; Jung Eun MOON ; Cheol Woo KO ; Chong-Kun CHEON ; Han-Wook YOO
Annals of Pediatric Endocrinology & Metabolism 2020;25(2):97-103
Purpose:
Cytochrome P450 oxidoreductase (POR) deficiency is a rare autosomal recessive disorder caused by mutations in the POR gene encoding an electron donor for all microsomal P450 enzymes. It is characterized by adrenal insufficiency, ambiguous genitalia, maternal virilization during pregnancy, and skeletal dysplasia. In this study, we investigated the clinical, hormonal, and molecular characteristics of patients with POR deficiency in Korea.
Methods:
This study included four patients with POR deficiency confirmed by biochemical and molecular analysis of POR. Clinical and biochemical findings were reviewed retrospectively. Mutation analysis of POR was performed by Sanger sequencing after polymerase chain reaction amplification of all coding exons and the exon-intron boundaries.
Results:
All patients presented with adrenal insufficiency and ambiguous genitalia regardless of their genetic sex. Two patients harbored homozygous p.R457H mutations in POR and presented with adrenal insufficiency and genital ambiguity without skeletal phenotypes. The other two patients with compound heterozygous mutations of c.[1329_1330insC];[1370G>A] (p.[I444Hfs*6];[R457H]) manifested skeletal abnormalities, such as craniosynostosis and radiohumeral synostosis, suggesting Antley-Bixler syndrome. They also had multiple congenital anomalies involving heart, kidney, and hearing ability. All patients were treated with physiologic doses of oral hydrocortisone.
Conclusion
We report the cases of 4 patients with POR deficiency identified by mutation analysis of POR. Although the study involved a small number of patients, the POR p.R457H mutation was the most common, suggesting founder effect in Korea. POR deficiency is rare and can be misdiagnosed as 21-hydroxylase or 17α-hydroxylase/17,20-lyase deficiency. Therefore, molecular analysis is critical for confirmatory diagnosis.

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