1.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.
2.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.
3.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.
4.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.
5.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.
6.Efficacy and Safety of Taltirelin Hydrate in Patients With Ataxia Due to Spinocerebellar Degeneration
Jin Whan CHO ; Jee-Young LEE ; Han-Joon KIM ; Joong-Seok KIM ; Kun-Woo PARK ; Seong-Min CHOI ; Chul Hyoung LYOO ; Seong-Beom KOH
Journal of Movement Disorders 2025;18(1):35-44
Objective:
We conducted this study to assess the efficacy and safety of taltirelin hydrate (TH) in patients with ataxia due to spinocerebellar degeneration (SCD).
Methods:
Patients were randomly assigned to either the taltirelin group (5 mg orally, twice daily) or the control group. The primary endpoint was the change in the Korean version of the Scale for the Assessment and Rating of Ataxia (K-SARA) score at 24 weeks. The secondary endpoints included changes in the K-SARA score at 4 and 12 weeks as well as the Clinical Global Impression Scale, the five-level version of the EuroQol five-dimensional questionnaire, the Tinetti balance test, and gait analysis at 4, 12, and 24 weeks.
Results:
A total of 149 patients (hereditary:nonhereditary=86:63) were enrolled. There were significant differences in the change in the K-SARA score at 24 weeks from baseline between the taltirelin group and the control group (-0.51±2.79 versus 0.36±2.62, respectively; p=0.0321). For the K-SARA items, the taltirelin group had significantly lower “Stance” and “Speech disturbance” subscores than the control group (-0.04±0.89 versus 0.23±0.79 and -0.07±0.74 versus 0.18±0.67; p=0.0270 and 0.0130, respectively). However, there were no significant differences in changes in other secondary efficacy outcome measures at 24 weeks from baseline between the two treatment arms (p>0.05).
Conclusion
Clinicians might consider the use of TH in the treatment of patients with ataxia due to SCD.
7.Is Colonoscopy Alone Adequate for Surveillance in Stage I Colorectal Cancer?
Seijong KIM ; Jung Kyong SHIN ; Yoonah PARK ; Jung Wook HUH ; Hee Cheol KIM ; Seong Hyeon YUN ; Woo Yong LEE ; Yong Beom CHO
Cancer Research and Treatment 2025;57(2):507-518
Purpose:
While colonoscopy is the standard surveillance tool for stage I colorectal cancer according to National Comprehensive Cancer Network guidelines, its effectiveness in detecting recurrence is debated. This study evaluates recurrence risk factors and patterns in stage I colorectal cancer to inform comprehensive surveillance strategies.
Materials and Methods:
A retrospective analysis of 2,248 stage I colorectal cancer patients who underwent radical surgery at Samsung Medical Center (2007-2018) was conducted. Exclusions were based on familial history, prior recurrences, preoperative treatments, and inadequate data. Surveillance included colonoscopy, laboratory tests, and computed tomography (CT) scans.
Results:
Stage I colorectal cancer patients showed favorable 5-year disease-free survival (98.3% colon, 94.6% rectum). Among a total of 1,467 colon cancer patients, 26 (1.76%) experienced recurrence. Of the 781 rectal cancer patients, 47 (6.02%) experienced recurrence. Elevated preoperative carcinoembryonic antigen levels and perineural invasion were significant recurrence risk factors in colon cancer, while tumor budding was significant in rectal cancer. Distant metastasis was the main recurrence pattern in colon cancer (92.3%), while rectal cancer showed predominantly local recurrence (50%). Colonoscopy alone detected recurrences in a small fraction of cases (3.7% in colon, 14.9% in rectum).
Conclusion
Although recurrence in stage I colorectal cancer is rare, relying solely on colonoscopy for surveillance may miss distant metastases or locoregional recurrence outside the colorectum. For high-risk patients, we recommend considering regular CT scans alongside colonoscopy. This targeted approach may enable earlier recurrence detection and improve outcomes in this subset while avoiding unnecessary scans for the low-risk majority.
8.Harnessing Institutionally Developed Clinical Targeted Sequencing to Improve Patient Survival in Breast Cancer: A Seven-Year Experience
Jiwon KOH ; Jinyong KIM ; Go-Un WOO ; Hanbaek YI ; So Yean KWON ; Jeongmin SEO ; Jeong Mo BAE ; Jung Ho KIM ; Jae Kyung WON ; Han Suk RYU ; Yoon Kyung JEON ; Dae-Won LEE ; Miso KIM ; Tae-Yong KIM ; Kyung-Hun LEE ; Tae-You KIM ; Jee-Soo LEE ; Moon-Woo SEONG ; Sheehyun KIM ; Sungyoung LEE ; Hongseok YUN ; Myung Geun SONG ; Jaeyong CHOI ; Jong-Il KIM ; Seock-Ah IM
Cancer Research and Treatment 2025;57(2):443-456
Purpose:
Considering the high disease burden and unique features of Asian patients with breast cancer (BC), it is essential to have a comprehensive view of genetic characteristics in this population. An institutional targeted sequencing platform was developed through the Korea Research-Driven Hospitals project and was incorporated into clinical practice. This study explores the use of targeted next-generation sequencing (NGS) and its outcomes in patients with advanced/metastatic BC in the real world.
Materials and Methods:
We reviewed the results of NGS tests administered to BC patients using a customized sequencing platform—FiRST Cancer Panel (FCP)—over 7 years. We systematically described clinical translation of FCP for precise diagnostics, personalized therapeutic strategies, and unraveling disease pathogenesis.
Results:
NGS tests were conducted on 548 samples from 522 patients with BC. Ninety-seven point six percentage of tested samples harbored at least one pathogenic alteration. The common alterations included mutations in TP53 (56.2%), PIK3CA (31.2%), GATA3 (13.8%), BRCA2 (10.2%), and amplifications of CCND1 (10.8%), FGF19 (10.0%), and ERBB2 (9.5%). NGS analysis of ERBB2 amplification correlated well with human epidermal growth factor receptor 2 immunohistochemistry and in situ hybridization. RNA panel analyses found potentially actionable and prognostic fusion genes. FCP effectively screened for potentially germline pathogenic/likely pathogenic mutation. Ten point three percent of BC patients received matched therapy guided by NGS, resulting in a significant overall survival advantage (p=0.022), especially for metastatic BCs.
Conclusion
Clinical NGS provided multifaceted benefits, deepening our understanding of the disease, improving diagnostic precision, and paving the way for targeted therapies. The concrete advantages of FCP highlight the importance of multi-gene testing for BC, especially for metastatic conditions.
9.Erratum to ‘Genomic biomarkers to predict response to atezolizumab plus bevacizumab immunotherapy in hepatocellular carcinoma: Insights from the IMbrave150 trial’ Clin Mol Hepatol 2024;30:807-823
Sun Young YIM ; Sung Hwan LEE ; Seung-Woo BAEK ; Bohwa SOHN ; Yun Seong JEONG ; Sang-Hee KANG ; Kena PARK ; Hyewon PARK ; Sunyoung S. LEE ; Ahmed O. KASEB ; Young Nyun PARK ; Sun-Hee LEEM ; Michael A. CURRAN ; Ji Hoon KIM ; Ju-Seog LEE
Clinical and Molecular Hepatology 2025;31(2):669-670
10.Endoscopic vacuum therapy for gastrointestinal transmural defects: a literature review
Tan Minh LE ; Van Huy TRAN ; Kyu Sung CHUNG ; Seong Woo JEON
Clinical Endoscopy 2025;58(2):181-190
Endoscopic vacuum therapy (EVT) has emerged as a transformative approach for managing gastrointestinal (GI) transmural defects, offering a less invasive and more promising alternative to surgery. Initially developed to address anastomotic leaks after rectal surgery, the application of EVT has expanded to include other locations within the GI tract. This review investigated the principles, indications, procedures, outcomes, challenges, and future perspectives of EVT for the management of GI transmural defects. In conclusion, EVT has demonstrated favorable outcomes in GI defect closure, with reduced complications, shortened hospital stay, and decreased morbidity rates as compared with conventional treatments. Although EVT faces challenges in some specific anatomical locations and in managing severe complications such as major bleeding, ongoing advancements in technology and standardization efforts offer promise for broader indications and better outcomes. Future perspectives include exploring novel EVT devices, refining patient selection criteria and pre-emptive applications, and standardizing procedural protocols.

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