1.Pregnancy and Retinal Disorders: Pathophysiology, Clinical Features, and Management
Minsub LEE ; Hyeong Min KIM ; Hyungwoo LEE ; Hyewon CHUNG
Journal of Retina 2026;11(1):1-12
During pregnancy, various physiological and metabolic changes occur throughout the female body, including in the retina. In particular, women at high risk, such as those with gestational diabetes or pregnancy-induced hypertension, often present with ocular symptoms.The major retinal disorders associated with pregnancy include diabetic retinopathy, hypertensive retinopathy, central serous chorioretinopathy, and retinal vascular occlusions. In this review, we provide an in-depth overview of recent studies investigating the impact of pregnancy on the retina and highlight the importance of retinal screening in pregnant women.
2.Reproducibility of Optical Coherence Tomography Radiomics after Cataract Surgery: Effects of Media Opacity, Signal Strength, and Region of Interest Selection
Na Hee KIM ; Hyeong Min KIM ; Hyewon CHUNG ; Hyungwoo LEE
Korean Journal of Ophthalmology 2026;40(3):236-246
Purpose:
To determine how cataract-related image-quality improvement and region of interest (ROI) definition affect the reproducibility of optical coherence tomography (OCT) radiomics features.
Methods:
This retrospective study included 50 eyes from 46 patients who underwent cataract surgery. Preoperative and postoperative OCT images were acquired using a standardized protocol. Radiomics features (n = 93) were extracted from two ROI configurations: retina ROI (Rr; retina only) and full ROI (Rf; retina, choroid, vitreous). Preoperative versus postoperative differences were tested with the Wilcoxon signed-rank test and Cohen’s d; repeatability was assessed with the intraclass correlation coefficient (ICC). Agreement between ROIs was evaluated with Wilcoxon statistics, Spearman correlation, the concordance correlation coefficient (CCC) and Bland-Altman plots. The influence of signal strength was analyzed with paired t-tests and Spearman correlation.
Results:
Postoperative signal strength significantly improved from 28.24 ± 3.16 to 31.40 ± 3.06 dB (p < 0.001). Significant preoperative/ postoperative changes occurred in 49 / 93 features (52.7%) within Rr and in 81 / 93 (87.1%) within Rf. ICC showed good-to-excellent repeatability in 51.6% of Rr features and 87.1% of Rf features, yet 29.0% of Rr features still demonstrated poor reliability. Across ROI methods, 94.6% of feature pairs differed significantly between Rr and Rf, and no feature achieved CCC ≥0.85. Only two descriptors—first-order statistics 10th percentile and GLDM (gray level dependence matrix) gray level variance—showed no significant change with surgery and minimal dependence on signal strength.
Conclusions
Radiomics features in OCT respond variably to media opacity, signal-to-noise ratio, and ROI definition: most are susceptible to these factors, yet a small subset remains stable across them. Limiting analysis to an anatomically precise retina- bounded ROI and enrolling eyes with comparable cataract status and signal-strength scores may therefore improve reproducibility. Implementing these standardizations will help future OCT-radiomics studies identify the most reliable biomarkers for clinical use.
3.Behavioral characterization of olfactory, auditory, and motor deficits in 5×FAD mice
Hyewon JANG ; Sueun LEE ; Yeongjun KIM ; Jeongmin LEE ; Jong-Choon KIM ; Joong-Sun KIM ; Jong-Hwan PARK ; Jinwook KIM ; Yeonghoon SON ; Changjong MOON
Journal of Veterinary Science 2026;27(3):e35-
Objective:
To characterize age-related motor, olfactory, and auditory changes in 5×FAD mice and assess associated AD pathologies and neuroinflammation in relevant brain regions.
Methods:
5×FAD and control mice were tested at 3, 6, and 12 months. Locomotor activity and motor coordination were assessed using the open field and rotarod tests, respectively. Olfactory and auditory performance were evaluated using the buried food test and the acoustic startle response test, respectively. Amyloid-β pathology and glial activation were examined in relevant nervous system components using western blot and immunohistochemistry analyses.
Results:
5×FAD mice showed no differences in open-field locomotion at any age, but exhibited a significantly greater passive clinging duration at 12 months compared to wild-type controls (p < 0.001). In the buried food test, olfactory latency was significantly prolonged in 5×FAD mice at 6 months (p = 0.035) and 12 months (p < 0.001). Acoustic startle amplitude was significantly reduced at 6 months (p = 0.030) and 12 months (p = 0.007). Amyloid-β and p-Tau accumulation and glial activation were elevated in the olfactory bulb and auditory cortex in an age-dependent manner.
Conclusions
and Relevance: This study provides an age-related behavioral and pathological characterization of olfactory and auditory impairments in the 5×FAD mouse model, with motor measures included as complementary assessments. Our findings broaden the spectrum of functional deficits associated with the AD pathology in this model.
4.Depth-Dependent Performance of Single-Shade Composite Resin: Assessing Color Adjustment Potential and Translucency
Hyewon SHIN ; Haeni KIM ; Juhyun LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(1):9-20
The blending effect refers to a phenomenon where the color difference between the restorative material and surrounding tooth structure appears smaller when they are adjacent to each other. The effect can be affected by the translucency of restorative material. This study evaluated the influence of cavity depth on the color adjustment potential (CAP) and translucency of a single-shade composite resin compared to multi-shade composite resins. A single-shade composite (Omnichroma) and two multi-shade composites (FiltekTM Z350 XT and Estelite® Sigma Quick) were tested in 1.5 mm and 3.0 mm cavity depths/thicknesses. CAP was assessed using the ΔEab* color difference between single and dual specimens. Translucency was measured using the translucency parameter (TP). The single-shade composite demonstrated significantly higher CAP and TP values compared to multi-shade composites across all depths/thicknesses (p < 0.0167). CAP decreased with increasing cavity depth for all composites. In 1.5 mm cavities, the single-shade composite achieved a clinically imperceptible color match (ΔEab* < 3.7). The higher translucency of the single-shade composite likely contributes to its enhanced blending effect and CAP. These results suggest that single-shade composites offer superior shade-matching ability due to their structural color phenomenon and high translucency. However, the decrease in CAP with increasing cavity depth indicates potential limitations in deeper restorations. Clinicians should consider appropriate techniques or additional products for optimal aesthetic outcomes in deeper cavities when using single-shade composites.
5.Clinical Significance of Various Pathogens Identified in Patients Experiencing Acute Exacerbations of COPD: A Multi-center Study in South Korea
Hyun Woo JI ; Soojoung YU ; Yun Su SIM ; Hyewon SEO ; Jeong-Woong PARK ; Kyung Hoon MIN ; Deog Kyeom KIM ; Hyun Woo LEE ; Chin Kook RHEE ; Yong Bum PARK ; Kyeong-Cheol SHIN ; Kwang Ha YOO ; Ji Ye JUNG
Tuberculosis and Respiratory Diseases 2025;88(2):292-302
Background:
Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD.
Methods:
This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests.
Results:
Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030).
Conclusion
This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.
6.KEAP1-NRF2 Pathway as a Novel Therapeutic Target for EGFR-Mutant Non-small Cell Lung Cancer
Jae-Sun CHOI ; Hye-Min KANG ; Kiyong NA ; Jiwon KIM ; Tae-Woo KIM ; Junyang JUNG ; Heejin LIM ; Hyewon SEO ; Seung Hyeun LEE
Tuberculosis and Respiratory Diseases 2025;88(1):138-149
Background:
Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer.
Methods:
We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition.
Results:
Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways.
Conclusion
We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.
7.Clinical Significance of Various Pathogens Identified in Patients Experiencing Acute Exacerbations of COPD: A Multi-center Study in South Korea
Hyun Woo JI ; Soojoung YU ; Yun Su SIM ; Hyewon SEO ; Jeong-Woong PARK ; Kyung Hoon MIN ; Deog Kyeom KIM ; Hyun Woo LEE ; Chin Kook RHEE ; Yong Bum PARK ; Kyeong-Cheol SHIN ; Kwang Ha YOO ; Ji Ye JUNG
Tuberculosis and Respiratory Diseases 2025;88(2):292-302
Background:
Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD.
Methods:
This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests.
Results:
Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030).
Conclusion
This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.
8.KEAP1-NRF2 Pathway as a Novel Therapeutic Target for EGFR-Mutant Non-small Cell Lung Cancer
Jae-Sun CHOI ; Hye-Min KANG ; Kiyong NA ; Jiwon KIM ; Tae-Woo KIM ; Junyang JUNG ; Heejin LIM ; Hyewon SEO ; Seung Hyeun LEE
Tuberculosis and Respiratory Diseases 2025;88(1):138-149
Background:
Kelch-like ECH-associated protein 1 (KEAP1)–nuclear factor erythroid- 2-related factor 2 (NRF2) pathway is a major regulator protecting cells from oxidative and metabolic stress. Studies have revealed that this pathway is involved in mediating resistance to cytotoxic chemotherapy and immunotherapy; however, its implications in oncogene-addicted tumors are largely unknown. This study aimed to elucidate whether this pathway could be a potential therapeutic target for epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer.
Methods:
We measured the baseline expression of NRF2 using EGFR-mutant parental cells and acquired gefitinib resistant cells. We investigated whether NRF2 inhibition affected cell death in vitro and tumor growth in vivo using a xenograft mouse model, and compared the transcriptional changes before and after NRF2 inhibition.
Results:
Baseline NRF2 expression was enhanced in PC9 and PC9 with gefitinib resistance (PC9/GR) cells than in other cell lines, with a more prominent expression in PC9/ GR. The NRF2 inhibitor induced NRF2 downregulation and cell death in a dose-dependent manner. Cotreatment with an NRF2 inhibitor enhanced osimertinib-induced cell death in vitro, and potentiated tumor growth inhibition in a PC9/GR xenograft model. Finally, RNA sequencing revealed that NRF2 inhibition resulted in the altered expression of multiple genes involved in various signaling pathways.
Conclusion
We identified that NRF2 inhibition enhanced cell death and inhibited tumor growth in tyrosine kinase inhibitor (TKI)-resistant lung cancer with EGFR-mutation. Thus, NRF2 modulation may be a novel therapeutic strategy to overcome the resistance to EGFR-TKIs.
9.Depth-Dependent Performance of Single-Shade Composite Resin: Assessing Color Adjustment Potential and Translucency
Hyewon SHIN ; Haeni KIM ; Juhyun LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(1):9-20
The blending effect refers to a phenomenon where the color difference between the restorative material and surrounding tooth structure appears smaller when they are adjacent to each other. The effect can be affected by the translucency of restorative material. This study evaluated the influence of cavity depth on the color adjustment potential (CAP) and translucency of a single-shade composite resin compared to multi-shade composite resins. A single-shade composite (Omnichroma) and two multi-shade composites (FiltekTM Z350 XT and Estelite® Sigma Quick) were tested in 1.5 mm and 3.0 mm cavity depths/thicknesses. CAP was assessed using the ΔEab* color difference between single and dual specimens. Translucency was measured using the translucency parameter (TP). The single-shade composite demonstrated significantly higher CAP and TP values compared to multi-shade composites across all depths/thicknesses (p < 0.0167). CAP decreased with increasing cavity depth for all composites. In 1.5 mm cavities, the single-shade composite achieved a clinically imperceptible color match (ΔEab* < 3.7). The higher translucency of the single-shade composite likely contributes to its enhanced blending effect and CAP. These results suggest that single-shade composites offer superior shade-matching ability due to their structural color phenomenon and high translucency. However, the decrease in CAP with increasing cavity depth indicates potential limitations in deeper restorations. Clinicians should consider appropriate techniques or additional products for optimal aesthetic outcomes in deeper cavities when using single-shade composites.
10.Tuberculous and Malignant Pleural Effusions With Adenosine Deaminase Levels of 40–70 IU/L: Trends in New Cases Over Time and Differentiation Between Groups
Jaehee LEE ; Jongmin PARK ; Jae Kwang LIM ; Ji Eun PARK ; Yong Hoon LEE ; Sun Ha CHOI ; Hyewon SEO ; Seung Soo YOO ; Shin Yup LEE ; Seung-Ick CHA ; Jae Yong PARK ; Chang Ho KIM
Journal of Korean Medical Science 2025;40(13):e35-
Background:
The diagnosis of tuberculous pleural effusion (TPE) often relies on pleural fluid adenosine deaminase (ADA) levels. The diagnostic utility of ADA, however, is influenced by the prevalence of tuberculosis (TB) in local populations. Malignant pleural effusion (MPE) cases can exhibit moderately elevated ADA levels comparable to those seen in TPE. As population aging potentially impacts ADA levels, global TB incidence is decreasing whereas the burden of malignancy is on the rise. Consequently, epidemiological shifts and temporal changes in ADA distribution complicate the differential diagnosis between TPE and MPE when ADA levels are within the 40–70 IU/L range. Nonetheless, data specific to this subset are scarce.
Methods:
This retrospective study included consecutive patients aged > 18 years with confirmed TPE and MPE, spanning from 2012 to 2023. ADA levels in pleural fluid were categorized into three groups: < 40 IU/L, 40–70 IU/L, and > 70 IU/L. The study examined annual trends in the frequency of new cases and ADA level distributions over time and identified discriminating factors between TPE and MPE in cases with ADA levels of 40–70 IU/L.
Results:
In total, 297 TPE and 369 MPE cases were included in this study. Over the study period, the frequency of TPE progressively declined, while that of MPE increased. In the most recent four-year period, new TPE and MPE cases with ADA levels of 40–70 IU/L occurred at comparable numbers. Multivariable analysis identified pleural fluid carcinoembryonic antigen (CEA) levels and the number of focal pleural nodules as independent predictors for MPE. Specifically, the presence of either CEA levels > 15.7 ng/mL or more than eight pleural nodules yielded the highest diagnostic accuracy with a sensitivity of 88%, specificity of 100%, and an area under the curve of 0.95.
Conclusion
The differential diagnosis between TPE and MPE with pleural ADA levels of 40–70 IU/L has become increasingly critical due to evolving epidemiological patterns and ADA distribution changes over time. Pleural fluid CEA levels and the characteristics of pleural nodules may offer valuable guidance in distinguishing between TPE and MPE within this diagnostic gray zone.

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