1.Method-Based Proficiency Test Program for Assessing Quality of Sanger Sequencing-Based Molecular Tests
Moon-Woo SEONG ; Ho-bin SUNG ; Jee-Soo LEE
Journal of Laboratory Medicine and Quality Assurance 2025;47(1):28-31
Background:
Sanger sequencing is a technology used to identify the gene sequence variants causing rare genetic disorders. However, designing and implementing a proficiency scheme for Sanger sequencing-based genetic testing is challenging because many molecular diagnostic laboratories are running sequencing tests for tens to hundreds of target genes. As such, we aimed to design and implement a method-based proficiency testing (PT) method for Sanger sequencing and to assess its feasibility in Korea.
Methods:
A pathogenic low density lipoprotein receptor (LDLR) variant was chosen as the positive PT material, and material without an LDLR variant was used as the negative PT material. We distributed the two PT materials with primer pair sets to 17 molecular diagnostic laboratories nationwide.We calculated the correct results (%) for variation type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation.
Results:
Fourteen laboratories responded to the survey. The results for the two PT materials were 100% correct for all evaluation points including variant type, zygosity, nucleotide change, amino acid change, variant classification, and clinical interpretation.
Conclusions
This pilot PT survey demonstrates a feasibility of using method-based PT for assessing the Sanger sequencing performance of molecular diagnostic laboratories in Korea.
2.A Case of a Cataract Patient with Equatorial and Posterior Zonular Weakness in Both Eyes
Jeong Woo KWON ; In Seok JEONG ; In Young CHUNG ; Seong Wook SEO ; Seong Jae KIM
Journal of the Korean Ophthalmological Society 2025;66(4):209-213
Purpose:
We present a case of equatorial and posterior zonular weakness observed during cataract surgery in both eyes with no prior history of trauma or surgery.Case summary: A 73-year-old woman visited out clinic and reported decreased visual acuity. She was found to have a best corrected visual acuity of 0.5 in both eyes. Cataracts were noted during a slit lamp examination and cataract surgery was subsequently performed. During the left eye surgery, although there was no evident weakening during the anterior capsulotomy, the equatorial and posterior zonules were damaged during phacoemulsification. This led to consistent aspiration of the equatorial and posterior capsule (PC) into the phaco-handpiece tip during epinucleus and cortex removal. The PC eventually ruptured necessitating anterior vitrectomy and a 3-piece intraocular lens insertion into the ciliary sulcus. Two weeks later, the right eye surgery encountered similar challenges in removing the epinucleus and cortex. The surgery was completed successfully by elevating the irrigation bottle, frequently injecting an ophthalmic viscoelastic device (OVD), and removing the remaining lens material using a bimanual irrigator/aspirator.
Conclusions
This case highlights that equatorial and posterior zonular weakness can occur in the absence of trauma or prior to surgery. To manage such cases, it is advisable to elevate the irrigation bottle height, continuously inject OVD during surgery, and use a bimanual irrigator/aspirator.
3.Anatomical Variations, Genitourinary Anomalies and Clinical Presentations in Obstructed Hemivagina and Ipsilateral Renal Anomaly Syndrome: Case Series
Hyun Jeong KIM ; Eun Ji LEE ; Yun-Woo CHANG ; Seong Sook HONG ; Jiyoung HWANG ; Boda NAM ; Sung Hwan BAE
Journal of the Korean Society of Radiology 2025;86(1):129-140
Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA) syndrome is a rare Müllerian duct anomaly, commonly characterized by uterus didelphys, obstructed hemivagina, and ipsilateral renal agenesis. While these are the three most common genitourinary anomalies in OHVIRA syndrome, a spectrum of urogenital anomalies can be present. Knowledge of this spectrum is crucial for proper patient management and treatment planning. In this case series, we report on five patients with OHVIRA syndrome, each presenting with a urogenital anomaly other than the typical renal agenesis or uterus didelphys. We highlight the gynecological complications encountered, which clinicians and radiologists should be aware of.
4.Outcomes of Deferring Percutaneous Coronary Intervention Without Physiologic Assessment for Intermediate Coronary Lesions
Jihoon KIM ; Seong-Hoon LIM ; Joo-Yong HAHN ; Jin-Ok JEONG ; Yong Hwan PARK ; Woo Jung CHUN ; Ju Hyeon OH ; Dae Kyoung CHO ; Yu Jeong CHOI ; Eul-Soon IM ; Kyung-Heon WON ; Sung Yun LEE ; Sang-Wook KIM ; Ki Hong CHOI ; Joo Myung LEE ; Taek Kyu PARK ; Jeong Hoon YANG ; Young Bin SONG ; Seung-Hyuk CHOI ; Hyeon-Cheol GWON
Korean Circulation Journal 2025;55(3):185-195
Background and Objectives:
Outcomes of deferring percutaneous coronary intervention (PCI) without invasive physiologic assessment for intermediate coronary lesions is uncertain.We sought to compare long-term outcomes between medical treatment and PCI of intermediate lesions without invasive physiologic assessment.
Methods:
A total of 899 patients with intermediate coronary lesions between 50% and 70% diameter-stenosis were randomized to the conservative group (n=449) or the aggressive group (n=450). For intermediate lesions, PCI was performed in the aggressive group, but was deferred in the conservative group. The primary endpoint was major adverse cardiac events (MACE, a composite of all-cause death, myocardial infarction [MI], or ischemia-driven any revascularization) at 3 years.
Results:
The number of treated lesions per patient was 0.8±0.9 in the conservative group and 1.7±0.9 in the aggressive group (p=0.001). At 3 years, the conservative group had a significantly higher incidence of MACE than the aggressive group (13.8% vs. 9.3%; hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.00–2.21; p=0.049), mainly driven by revascularization of target intermediate lesion (6.5% vs. 1.1%; HR, 5.69; 95% CI, 2.20–14.73;p<0.001). Between 1 and 3 years after the index procedure, compared to the aggressive group, the conservative group had significantly higher incidence of cardiac death or MI (3.2% vs.0.7%; HR, 4.34; 95% CI, 1.24–15.22; p=0.022) and ischemia-driven any revascularization.
Conclusions
For intermediate lesions, medical therapy alone, guided only by angiography, was associated with a higher risk of MACE at 3 years compared with performing PCI, mainly due to increased revascularization.
5.Force and moment analysis of clear aligners: Impact of material properties and design on premolar rotation
Dong-Woo KIM ; Hyun-Jun LEE ; Ki Beom KIM ; Sung-Hun KIM ; Seong-Sik KIM ; Soo-Byung PARK ; Youn-Kyung CHOI ; Yong-Il KIM
The Korean Journal of Orthodontics 2025;55(3):212-223
Objective:
To quantitatively analyze and compare the forces and moments generated by thermoformed polyethylene terephthalate glycol (PETG) and direct-printed TC-85 clear aligners (CAs), with various margin designs, during premolar rotation.
Methods:
In total, 132 CAs were fabricated and divided into four groups (n = 33 per group). Group C consisted of thermoformed PETG aligners with a 2 mm gingival margin. Group E comprised direct-printed TC-85 aligners with equi-gingival margin, whereas Group G utilized direct-printed TC-85 aligners with 2 mm gingival margins.Finally, Group T featured direct-printed TC-85 aligners with an additional 1 mm thickness at the mesial embrasure. The forces and moments were measured using a 6-axis force/moment transducer at 2°, 3°, and 4° of rotation. All measurements were conducted at 37°C to simulate intraoral conditions. Forces were measured in the buccolingual, anteroposterior, and vertical directions, while moments were measured in the mesiodistal, buccolingual, and rotational planes.
Results:
The PETG aligners (Group C) showed significantly increased buccal and posterior force across the rotation angles (P < 0.05), whereas the intrusive force remained consistent. In contrast, the TC-85 aligners maintained consistent forces across all rotation angles.Direct-printed aligners demonstrated significantly lower intrusive forces than PETG aligners (P < 0.001). Group T exhibited reduced unwanted forces while maintaining effective rotational moments. Furthermore, all direct-printed aligners showed more predictable force delivery patterns than thermoformed aligners.
Conclusions
Direct-printed TC-85 aligners demonstrated superior force consistency and reduced unwanted side effects compared with traditional PETG aligners. Although marginal design modifications did not significantly improve rotational efficiency, they effectively reduced unwanted intrusive forces.
6.Human induced pluripotent stem cell-cardiomyocytes for cardiotoxicity assessment: a comparative study of arrhythmiainducing drugs with multi-electrode array analysis
Na Kyeong PARK ; Yun-Gwi PARK ; Ji-Hee CHOI ; Hyung Kyu CHOI ; Sung-Hwan MOON ; Soon-Jung PARK ; Seong Woo CHOI
The Korean Journal of Physiology and Pharmacology 2025;29(2):257-269
Reliable preclinical models for assessing drug-induced cardiotoxicity are essential to reduce the high rate of drug withdrawals during development. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a promising platform for such assessments due to their expression of cardiacspecific ion channels and electrophysiological properties. In this study, we investigated the effects of eight arrhythmogenic drugs—E4031, nifedipine, mexiletine, JNJ303, flecainide, moxifloxacin, quinidine, and ranolazine—on hiPSC-CMs derived from both healthy individuals and a long QT syndrome (LQTS) patient using multielectrode array systems. The results demonstrated dose-dependent changes in field potential duration and arrhythmogenic risk, with LQTS-derived hiPSC-CMs showing increased sensitivity to hERG channel blockers such as E4031. Furthermore, the study highlights the potential of hiPSC-CMs to model disease-specific cardiac responses, providing insights into genetic predispositions and personalized drug responses.Despite challenges related to the immaturity of hiPSC-CMs, their ability to recapitulate human cardiac electrophysiology makes them a valuable tool for preclinical cardiotoxicity assessments. This study underscores the utility of integrating patientderived hiPSC-CMs with advanced analytical platforms, such as multi-electrode array systems, to evaluate drug-induced electrophysiological changes. These findings reinforce the role of hiPSC-CMs in drug development, facilitating safer and more efficient screening methods while supporting precision medicine applications.
7.Home High-Flow Nasal Cannula in Patients with Chronic Respiratory Failure: A Literature Review and Suggestions for Clinical Practice
Youjin CHANG ; Moon Seong BAEK ; Sei Won KIM ; Su Hwan LEE ; Jung Soo KIM ; So Young PARK ; Jin Woo KIM ; Jae Hwa CHO ; Sunghoon PARK
Tuberculosis and Respiratory Diseases 2025;88(2):264-277
High-flow nasal cannula (HFNC) is a noninvasive respiratory support system that delivers air that is heated at 31°C−38°C, humidified 100%, and oxygen-enriched at a constant high flow rate of 15−60 L/min. Because of its numerous physiological benefits, convenience, and minimal side effects, HFNC has been increasingly used over the past decade in patients with acute hypoxemic respiratory failure, yet the clinical benefits of long-term HFNC remain uncertain. Several studies have suggested its potential use as an alternative home oxygen therapy for patients with chronic stable lung diseases, such as chronic obstructive pulmonary disease (COPD), interstitial lung disease, and bronchiectasis. The use of long-term home HFNC in patients with chronic respiratory failure is an emerging area with promising potential. Despite limited clinical research, this review aims to describe the physiology of HFNC use and summarize the current evidence on its long-term application, to provide healthcare providers with insights and perspectives on the potential role of long-term home HFNC.
8.Novel non-invasive and quantitative assessment of the renal function of transplanted kidneys using Doppler ultrasonography with the vascular index of superb microvascular imaging
Sung Hwan BAE ; Eun Ji LEE ; Jiyoung HWANG ; Seong Sook HONG ; Yun-Woo CHANG ; Boda NAM
Ultrasonography 2025;44(2):160-169
Purpose:
This study assessed the reproducibility and clinical value of the vascular index (VI), derived from superb microvascular imaging (SMI) using Doppler ultrasonography, for evaluating renal function in transplanted kidneys.
Methods:
This retrospective study included 63 renal transplant patients who underwent grayscale and Doppler ultrasonography with SMI from January 2022 to February 2023. The VI of the transplanted kidneys was measured using three methods (VIbox, VIF1, VIF2). The VI was compared across chronic kidney disease (CKD) groups categorized by estimated glomerular filtration rate (eGFR) and Kidney Disease: Improving Global Outcomes (KDIGO) CKD risk groups based on eGFR and albuminuria. The correlation between VI and renal function was evaluated. Univariate and multivariate linear regression analyses were used to identify predictors of eGFR.
Results:
Significant differences in VI were observed among CKD groups based on eGFR (VIbox, P=0.001; VIF1, P<0.001; VIF2, P<0.001) and KDIGO CKD groups based on eGFR and albuminuria (VIbox, P=0.039; VIF1, P=0.001; VIF2, P<0.001). VIF1 and VIF2 demonstrated moderate/high correlations with eGFR (r=0.627, P<0.001 and r=0.657, P<0.001, respectively) and serum creatinine (r=-0.626, P<0.001 and r=-0.649, P<0.001, respectively). VIbox moderately correlated with eGFR (r=0.445, P<0.001). Multivariate regression identified the urine albumincreatinine ratio (ACR) (adjusted odds ratio [aOR], 1.122; 95% confidence interval [CI], -0.007 to, 0.000; P=0.030) and VIF2 (aOR, 1.114; 95% CI, 0.466 to 1.235; P<0.001) were independently associated with eGFR.
Conclusion
The VI measured by drawing a region of interest along the border of the transplanted kidney in SMI (VIF2) is highly reproducible and correlates well with eGFR. Both VIF2 and ACR independently predict eGFR.
9.Virtual Reality-Based Cognitive Behavior Therapy for Major Depressive Disorder: An Alternative to Pharmacotherapy for Reducing Suicidality
Miwoo LEE ; Sooah JANG ; Hyun Kyung SHIN ; Sun-Woo CHOI ; Hyung Taek KIM ; Jihee OH ; Ji Hye KWON ; Youngjun CHOI ; Suzi KANG ; In-Seong BACK ; Jae-Ki KIM ; San LEE ; Jeong-Ho SEOK
Yonsei Medical Journal 2025;66(1):25-36
Purpose:
Cognitive behavioral therapy (CBT) has long been recognized as an effective treatment for depression and suicidality.Virtual reality (VR) technology is widely used for cognitive training for conditions such as anxiety disorder and post-traumatic stress disorder, but little research has considered VR-based CBT for depressive symptoms and suicidality. We tested the effectiveness and safety of a VR-based CBT program for depressive disorders.
Materials and Methods:
We recruited 57 participants from May 2022 through February 2023 using online advertisements. This multi-center, assessor-blinded, randomized, controlled exploratory trial used two groups: VR treatment group and treat as usual (TAU) group. VR treatment group received a VR mental health training/education program. TAU group received standard pharmacotherapy. Assessments were conducted at baseline, immediately after the 6-week treatment period, and 4 weeks after the end of the treatment period in each group.
Results:
Depression scores decreased significantly over time in both VR treatment and TAU groups, with no differences between the two groups. The suicidality score decreased significantly only in VR group. No group differences were found in the remission or response rate for depression, perceived stress, or clinical severity. No adverse events or motion sickness occurred during the VR treatment program.
Conclusion
VR CBT treatment for major depressive disorder has the potential to be equivalent to the gold-standard pharmacotherapy in reducing depressive symptoms, suicidality, and related clinical symptoms, with no difference in improvement found in this study. Thus, VR-based CBT might be an effective alternative to pharmacotherapy for depressive disorders.
10.Environmental disease monitoring by regional Environmental Health Centers in Korea: a narrative review
Myung-Sook PARK ; Hwan-Cheol KIM ; Woo Jin KIM ; Yun-Chul HONG ; Won-Jun CHOI ; Seock-Yeon HWANG ; Jiho LEE ; Young-Seoub HONG ; Yong-Dae KIM ; Seong-Chul HONG ; Joo Hyun SUNG ; Inchul JEONG ; Kwan LEE ; Won-Ju PARK ; Hyun-Joo BAE ; Seong-Yong YOON ; Cheolmin LEE ; Kyoung Sook JEONG ; Sanghyuk BAE ; Jinhee CHOI ; Ho-Hyun KIM
The Ewha Medical Journal 2025;48(1):e3-
This study explores the development, roles, and key initiatives of the Regional Environmental Health Centers in Korea, detailing their evolution through four distinct phases and their impact on environmental health policy and local governance. It chronicles the establishment and transformation of these centers from their inception in May 2007, through four developmental stages. Originally named Environmental Disease Research Centers, they were subsequently renamed Environmental Health Centers following legislative changes. The analysis includes the expansion in the number of centers, the transfer of responsibilities to local governments, and the launch of significant projects such as the Korean Children’s Environmental Health Study (Ko-CHENS ). During the initial phase (May 2007–February 2009), the 10 centers concentrated on research-driven activities, shifting from a media-centered to a receptor-centered approach. In the second phase, prompted by the enactment of the Environmental Health Act, six additional centers were established, broadening their scope to address national environmental health issues. The third phase introduced Ko-CHENS, a 20-year national cohort project designed to influence environmental health policy by integrating research findings into policy frameworks. The fourth phase marked a decentralization of authority, empowering local governments and redefining the centers' roles to focus on regional environmental health challenges. The Regional Environmental Health Centers have significantly evolved and now play a crucial role in addressing local environmental health issues and supporting local government policies. Their capacity to adapt and respond to region-specific challenges is essential for the effective implementation of environmental health policies, reflecting geographical, socioeconomic, and demographic differences.

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