2.Clinical Characteristics and Visual Prognostic Biomarkers in Pericentral Retinitis Pigmentosa: A Study in a South Korean Cohort
Su Ho BAE ; Seung Woo CHOI ; Chang Ki YOON ; Un Chul PARK ; Kyu Hyung PARK ; Eun Kyoung LEE
Korean Journal of Ophthalmology 2025;39(2):157-169
Purpose:
To investigate the clinical characteristics of South Korean patients with pericentral retinitis pigmentosa (RP) and to identify clinical biomarkers associated with rapid visual acuity decline based on baseline factors.
Methods:
This retrospective study included 59 eyes of 31 patients diagnosed with pericentral RP. Comprehensive ophthalmological examinations and genetic sequencing were conducted to assess the baseline characteristics. For biomarker analysis, eyes were categorized into two groups based on the annual rate of change in visual acuity. The clinical findings of the two groups were evaluated to identify the biomarkers associated with rapid loss of visual acuity.
Results:
Patients with pericentral RP in this study exhibited a mean best-corrected visual acuity of 0.17 ± 0.23 in logarithm of the minimum angle of resolution. The visual field test showed annular or semicircular scotoma with relatively preserved periphery and 27 eyes (45.8%) exhibited no macular complications in optical coherence tomography. Genetic analysis identified genes associated with previous typical and pericentral RP studies but also highlighted that many genetic causes of pericentral RP remain unidentified. Of the 55 eyes for which the rate of visual acuity change could be estimated, 18 exhibited an annual decline of ≥10%, whereas 37 showed an annual decline of <10%. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram correlated with rapid visual acuity decline in the multivariate analysis.
Conclusions
South Korean patients with pericentral RP exhibited a milder phenotype compared to typical RP patients reported in previous studies. Genetic analysis revealed heterogeneity, with mutations in some genes commonly associated with milder forms of RP. Male sex and prolonged b-wave latency on dark-adapted 0.01 electroretinogram were significant biomarkers for predicting rapid visual acuity decline. Monitoring initial b-wave latency is important for predicting visual decline, particularly in male patients with pericentral RP.
3.Effect of Combined Treatment of Metoclopramide With Platinum-Based Drugs on Apoptosis in AMC-HN4 Cells
Jong Won PARK ; Seon Min WOO ; Jong In JEONG ; Jae Man LEE ; Ji Won LEE ; Dong Eun KIM ; Taeg Kyu KWON
Korean Journal of Otolaryngology - Head and Neck Surgery 2025;68(3):113-120
Background and Objectives:
Metoclopramide is an antagonist of dopamine D2 receptor and is capable of alleviating chemotherapy-induced nausea and vomiting. However, its underlying mechanisms and function in improving the efficiency of chemotherapy are not fully understood. In this study, we investigated the sensitizing effect of metoclopramide on the platinum-based drugs-mediated apoptosis in human head and neck cancer cells.Subjects and Method Apoptosis was analyzed using a cell-based cytometer. The protein expression and messenger ribonucleic acid (mRNA) levels were assessed by Western blotting and real-time polymerase chain reaction, respectively.
Results:
Metoclopramide sensitized the platinum-based drug (cisplatin and oxaliplatin)-mediated apoptosis in AMC-HN4 cells, but not in normal cells. Mechanistically, we found that metoclopramide decreased Mcl-1 protein expression through post-translational regulation. Moreover, the overexpression of Mcl-1 prevented apoptosis by combined treatment of metoclopramide and platinum-based drugs.
Conclusion
Metoclopramide induced proteasome-mediated Mcl-1 downregulation, resulting in increased sensitivity to platinum-based drugs.
4.Prospective Evaluation of Accelerated Brain MRI Using Deep Learning-Based Reconstruction: Simultaneous Application to 2D Spin-Echo and 3D Gradient-Echo Sequences
Kyu Sung CHOI ; Chanrim PARK ; Ji Ye LEE ; Kyung Hoon LEE ; Young Hun JEON ; Inpyeong HWANG ; Roh Eul YOO ; Tae Jin YUN ; Mi Ji LEE ; Keun-Hwa JUNG ; Koung Mi KANG
Korean Journal of Radiology 2025;26(1):54-64
Objective:
To prospectively evaluate the effect of accelerated deep learning-based reconstruction (Accel-DL) on improving brain magnetic resonance imaging (MRI) quality and reducing scan time compared to that in conventional MRI.
Materials and Methods:
This study included 150 participants (51 male; mean age 57.3 ± 16.2 years). Each group of 50 participants was scanned using one of three 3T scanners from three different vendors. Conventional and Accel-DL MRI images were obtained from each participant and compared using 2D T1- and T2-weighted and 3D gradient-echo sequences. Accel-DL acquisition was achieved using optimized scan parameters to reduce the scan time, with the acquired images reconstructed using U-Net-based software to transform low-quality, undersampled k-space data into high-quality images. The scan times of Accel-DL and conventional MRI methods were compared. Four neuroradiologists assessed the overall image quality, structural delineation, and artifacts using Likert scale (5- and 3-point scales). Inter-reader agreement was assessed using Fleiss’ kappa coefficient. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated, and volumetric quantification of regional structures and white matter hyperintensities (WMHs) was performed.
Results:
Accel-DL showed a mean scan time reduction of 39.4% (range, 24.2%–51.3%). Accel-DL improved overall image quality (3.78 ± 0.71 vs. 3.36 ± 0.61, P < 0.001), structure delineation (2.47 ± 0.61 vs. 2.35 ± 0.62, P < 0.001), and artifacts (3.73 ± 0.72 vs. 3.71 ± 0.69, P = 0.016). Inter-reader agreement was fair to substantial (κ = 0.34–0.50). SNR and CNR increased in Accel-DL (82.0 ± 23.1 vs. 31.4 ± 10.8, P = 0.02; 12.4 ± 4.1 vs. 4.4 ± 11.2, P = 0.02). Bland-Altman plots revealed no significant differences in the volumetric measurements of 98.2% of the relevant regions, except in the deep gray matter, including the thalamus. Five of the six lesion categories showed no significant differences in WMH segmentation, except for leukocortical lesions (r = 0.64 ± 0.29).
Conclusion
Accel-DL substantially reduced the scan time and improved the quality of brain MRI in both spin-echo and gradientecho sequences without compromising volumetry, including lesion quantification.
5.Comparison of interference from eccentric movements of dental crowns fabricated via dynamic jaw motion tracking and conventional methods: a double-blind clinical study
Myung Hyun PARK ; Keunbada SON ; Myoung-Uk JIN ; So-Yeun KIM ; Kyu-Bok LEE
The Journal of Advanced Prosthodontics 2025;17(1):36-46
PURPOSE:
The purpose of this clinical study was to evaluate the extent of intraoral occlusal adjustment required for zirconia crowns designed with a dynamic jaw motion tracking method compared to a conventional approach.
MATERIALS AND METHODS:
Fifteen patients needing zirconia crown restorations in the anterior or posterior regions participated in this study. Following tooth preparation, dynamic jaw motion tracking records were gathered using a tracking device. These records were imported into computer-aided design software and aligned with scanned upper and lower jaw data to design each crown's occlusal surface. Two crowns were fabricated for each patient: one using motion tracking data and another without it. Crowns were scanned pre- and post-adjustment following standard protocols. The scanned data were analyzed with 3D inspection software to calculate occlusal adjustments in the segmented occlusal area as root mean square values, with a paired t-test used for statistical analysis (α = 0.05).
RESULTS:
Crowns designed with motion tracking data required significantly less intraoral occlusal adjustment than those designed conventionally (P = .028).
CONCLUSION
Dynamic jaw motion tracking in crown design reduces the extent of intraoral occlusal adjustment, potentially enhancing clinical efficiency.
6.Development of Cardiovascular Disease Therapeutics Using Space Environment:Opportunities and Challenges
Korean Journal of Aerospace and Environmental Medicine 2025;35(1):28-32
As research on the unique effects of space environment, especially microgravity and cosmic radiation, on the cardiovascular system is being conducted, research on the development of cardiovascular therapeutics using the space environment is attracting attention. This review comprehensively analyzes the current status and prospects of cardiovascular therapeutics development research utilizing space environment.Microgravity environment has been shown to have a positive effect on the proliferation and differentiation of cardiac progenitor cells and induced pluripotent stem cell-derived cardio myocytes. Cardiac tissue culture and organoid technology have enabled more effective drug screening and disease modeling than on the ground, and changes in gene expression such as Aquaporin-4 have been found to play an important role in cardiac function. Cosmic radiation can cause myocardial remodeling, fibrosis, and vascular endothelial dysfunction, and the underlying mechanisms of these effects include increased oxidative stress, promotion of inflammatory responses, deoxyribo nucleic acid damage, and cell death. Currently, the development of drugs that can prevent or treat cardiovascular damage caused by the space environment is in the early stages, and future research is expected to focus on developing personalized treatments and exploring the potential applications of space medicine research results to terrestrial medicine.
7.Persistent influence of past obesity on current adiponectin levels and mortality in patients with type 2 diabetes
Min-Ji KIM ; Sung-Woo KIM ; Bitna HA ; Hyang Sook KIM ; So-Hee KWON ; Jonghwa JIN ; Yeon-Kyung CHOI ; Keun-Gyu PARK ; Jung Guk KIM ; In-Kyu LEE ; Jae-Han JEON
The Korean Journal of Internal Medicine 2025;40(2):299-309
Background/Aims:
Adiponectin, a hormone primarily produced by adipocytes, typically shows an inverse relationship with body mass index (BMI). However, some studies have reported a positive correlation between the two. Thus, this study aimed to examine the relationship between adiponectin level and BMI in diabetic patients, focusing on the impact of past obesity on current adiponectin levels.
Methods:
We conducted an observational study analyzing data from 323 diabetic patients at Kyungpook National University Hospital. Based on past and current BMIs, participants were categorized into never-obese (nn, n = 106), previously obese (on, n = 43), and persistently obese (oo, n = 73) groups based on a BMI threshold of 25 kg/m2. Adiponectin level and BMI were key variables. Kaplan–Meier analysis assessed their impact on all-cause mortality up to August 2023, with survival differences based on adiponectin quartiles and follow-up starting from patient enrollment (2010–2015).
Results:
The analysis revealed a significant inverse correlation between adiponectin level and past maximum BMI. The on group exhibited approximately 10% lower adiponectin levels compared to the nn group. This association remained significant after adjusting for current BMI, age, and sex, highlighting the lasting influence of previous obesity on adiponectin levels. Furthermore, survival analysis indicated that patients in the lowest adiponectin quartile had reduced survival, with a statistically significant trend (p = 0.062).
Conclusions
Findings of this study suggest that lower adiponectin levels, potentially reflecting past obesity, are associated with decreased survival in diabetic patients, underscoring a critical role of adiponectin in long-term health outcomes.
8.Medical disputes involving lower gastrointestinal endoscopies: cases from the Korean Medical Dispute Mediation and Arbitration Agency
Eun Hye OH ; Jeong Eun SHIN ; Jun Yong BAE ; Yoon Suk LEE ; Yehyun PARK ; Yong Hwan KWON ; Chang Nyol PAIK ; Jun Kyu LEE ; Tae Hee LEE
The Korean Journal of Internal Medicine 2025;40(3):404-426
Background/Aims:
As the number of lower gastrointestinal endoscopies and high-risk examinees increases, the incidence of adverse events associated with these endoscopies has also increased. Medical disputes and lawsuits related to adverse events are rapidly increasing.
Methods:
Medical disputes related to lower gastrointestinal endoscopy that had been filed in Korean Medical Dispute Mediation and Arbitration Agency (K-medi) from April 2012 to August 2020 were evaluated with the corresponding medical records and written appraisal. Facilities, patients, procedures, adverse events, and outcome-related variables related to medical disputes were analyzed.
Results:
As the number of lower gastrointestinal endoscopies in Korea increases each year, the number of medical disputes related to lower gastrointestinal endoscopy appraised by K-medi has also increased yearly during the same period. Among the 121 cases analyzed, 86 (71.1%) were conciliated and 35 (28.9%) were cosigned by prosecution. Perforations accounted for the largest proportion of cases (93 cases, 76.9%). Most patients (n = 119, 98.3%) underwent non-emergent procedures, and only 10 (8.3%) underwent them for therapeutic purposes. Approximately one-fifth of the patients (n = 25, 20.7%) died.
Conclusions
The number of medical disputes related to lower gastrointestinal endoscopy are increasing. To prevent this, it is important to review the data on existing cases and establish specific response guidelines.
9.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.

Result Analysis
Print
Save
E-mail