1.Revisiting Age-Related Normative Hearing Levels in Korea
Sang-Yoon HAN ; Hee Won SEO ; Seung Hwan LEE ; Jae Ho CHUNG
Journal of Korean Medical Science 2025;40(2):e3-
Background:
Hearing level reference values based on the results of recent audiometry have not been established for the general population of South Korea. This study aimed to evaluate the mean hearing levels of each age group and to measure the annual progression of hearing loss.
Methods:
We used the database of the eighth and ninth Korea National Health and Nutrition Examination Survey from 2020 to 2022, and included participants with normal tympanic membranes and without occupational noise exposure. Mean hearing levels were calculated by averaging hearing levels at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz. Hearing loss was defined as a hearing level exceeding 25 dB in the better ear, and severity of hearing loss was classified as moderate, moderately severe, severe, and profound, following the World Health Organization classification.
Results:
Hearing levels and the proportions of patients with hearing loss increased with age. Hearing levels were 9.11 ± 6.28 dB, 13.33 ± 7.85 dB, 19.90 ± 10.30 dB, and 31.95 ± 13.37 dB in those in their 40s, 50s, 60s, and 70s, respectively, and the proportions of patients with hearing loss were 1.81%, 7.51%, 25.32%, and 63.94%, respectively. The annual increase in hearing level was 0.71 dB, and increases were greater at higher frequencies. Hearing loss was also worse in men.
Conclusion
The present study provides reference values for normal hearing levels by age group, and indirectly reveals the progression of age-related hearing loss. Based on the results, physicians will be able to provide appropriate advice regarding hearing levels and the need for monitoring in the elderly.
2.Emerging Innovations in Acne Management: A Focus on NonPharmacological Therapeutic Devices
Ji Yeon HONG ; Joon SEOK ; Hye Sung HAN ; Kui Young PARK
Journal of Korean Medical Science 2025;40(9):e118-
Acne is a chronic inflammatory condition affecting the sebaceous glands, with approximately 80% of individuals experiencing it at some point in their lives. Among adolescents, the incidence is reported to exceed 85%. The disease can significantly impact both physical and emotional aspects of a person’s quality of life, leading to permanent scarring, poor self-image, depression, and anxiety. The standard first-line treatment for acne vulgaris includes conventional pharmacological approaches such as keratolytics, topical or oral antibiotics, retinoids, and hormonal agents. However, these treatments are not universally effective due to patient noncompliance, adverse drug effects, and the emergence of antibiotic resistance in Cutibacterium acnes, often resulting in high rates of recurrence. Consequently, non-pharmacological therapies have been developed as safe and effective alternatives or supplements to pharmacological treatment. These non-pharmacological approaches can serve as standalone treatment modalities, adjuncts to pharmacological therapy, or maintenance treatments. Current literature lacks comprehensive data on the classification of these non-pharmacological treatment options. This paper aims to provide a brief overview of recent research on the practical applications and potential mechanisms of nonpharmacological therapies for both acne and acne scars. Through elucidating the distinct mechanisms and therapeutic roles of these treatments, we aim to assist dermatologists and other healthcare providers in formulating more effective disease management strategies, thereby encouraging further research in this area.
3.Revisiting Age-Related Normative Hearing Levels in Korea
Sang-Yoon HAN ; Hee Won SEO ; Seung Hwan LEE ; Jae Ho CHUNG
Journal of Korean Medical Science 2025;40(2):e3-
Background:
Hearing level reference values based on the results of recent audiometry have not been established for the general population of South Korea. This study aimed to evaluate the mean hearing levels of each age group and to measure the annual progression of hearing loss.
Methods:
We used the database of the eighth and ninth Korea National Health and Nutrition Examination Survey from 2020 to 2022, and included participants with normal tympanic membranes and without occupational noise exposure. Mean hearing levels were calculated by averaging hearing levels at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz. Hearing loss was defined as a hearing level exceeding 25 dB in the better ear, and severity of hearing loss was classified as moderate, moderately severe, severe, and profound, following the World Health Organization classification.
Results:
Hearing levels and the proportions of patients with hearing loss increased with age. Hearing levels were 9.11 ± 6.28 dB, 13.33 ± 7.85 dB, 19.90 ± 10.30 dB, and 31.95 ± 13.37 dB in those in their 40s, 50s, 60s, and 70s, respectively, and the proportions of patients with hearing loss were 1.81%, 7.51%, 25.32%, and 63.94%, respectively. The annual increase in hearing level was 0.71 dB, and increases were greater at higher frequencies. Hearing loss was also worse in men.
Conclusion
The present study provides reference values for normal hearing levels by age group, and indirectly reveals the progression of age-related hearing loss. Based on the results, physicians will be able to provide appropriate advice regarding hearing levels and the need for monitoring in the elderly.
4.Emerging Innovations in Acne Management: A Focus on NonPharmacological Therapeutic Devices
Ji Yeon HONG ; Joon SEOK ; Hye Sung HAN ; Kui Young PARK
Journal of Korean Medical Science 2025;40(9):e118-
Acne is a chronic inflammatory condition affecting the sebaceous glands, with approximately 80% of individuals experiencing it at some point in their lives. Among adolescents, the incidence is reported to exceed 85%. The disease can significantly impact both physical and emotional aspects of a person’s quality of life, leading to permanent scarring, poor self-image, depression, and anxiety. The standard first-line treatment for acne vulgaris includes conventional pharmacological approaches such as keratolytics, topical or oral antibiotics, retinoids, and hormonal agents. However, these treatments are not universally effective due to patient noncompliance, adverse drug effects, and the emergence of antibiotic resistance in Cutibacterium acnes, often resulting in high rates of recurrence. Consequently, non-pharmacological therapies have been developed as safe and effective alternatives or supplements to pharmacological treatment. These non-pharmacological approaches can serve as standalone treatment modalities, adjuncts to pharmacological therapy, or maintenance treatments. Current literature lacks comprehensive data on the classification of these non-pharmacological treatment options. This paper aims to provide a brief overview of recent research on the practical applications and potential mechanisms of nonpharmacological therapies for both acne and acne scars. Through elucidating the distinct mechanisms and therapeutic roles of these treatments, we aim to assist dermatologists and other healthcare providers in formulating more effective disease management strategies, thereby encouraging further research in this area.
5.Coronary Artery Dimension-Adjusted Subtended Myocardial Mass Obtained With Coronary CT Angiography as a Potential Biomarker of Myocardial Ischemia in Patients With Hypertrophic Cardiomyopathy
Jung Han WOO ; Hyewon CHOI ; Min Jae CHA
Korean Journal of Radiology 2025;26(4):324-332
Objective:
To compare coronary artery dimension-adjusted subtended myocardial mass between patients with hypertrophic cardiomyopathy (HCM) and a normal population without detectable atherosclerosis, and between HCM patients with and without chest pain.
Materials and Methods:
Twenty-five patients with HCM but no detectable atherosclerosis on coronary computed tomography angiography (CCTA) were included in the study. This group comprised 14 patients with chest pain and 11 patients without chest pain. They were matched with 25 healthy participants based on sex, age, coronary dominance pattern, and body surface area. The minimal lumen area (MLA) and subtended myocardial volume (V sub) were assessed in the left main (LM), proximal left anterior descending (pLAD), proximal left circumflex (pLCx), and proximal right coronary (pRCA) arteries. Additionally, an index of the subtended myocardial mass adjusted for the MLA, calculated as V sub/MLA 2 , was determined.
Results:
MLA was significantly larger in patients with HCM compared to the control group in LM (20.93 ± 6.31 mm 2 vs.15.24 ± 3.90 mm 2 , P< 0.001), pLAD (14.28 ± 3.55 mm 2 vs. 11.36 ± 2.07 mm 2, P = 0.001), pLCx (10.94 ± 3.60 mm 2 vs. 9.15 ± 2.93 mm 2 , P = 0.045), and pRCA (13.41 ± 4.85 mm 2 vs. 11.22 ± 3.20 mm 2 , P = 0.018). Despite an increase in coronary luminal area, patients with HCM exhibited significantly higher V sub/MLA 2 compared to the control group in both the pLAD (403.56 ± 200.35 mm -1 vs. 241.70 ± 85.87 mm -1 , P < 0.001) and the pRCA (186.06 ± 95.07 mm -1 vs. 125.07 ± 70.18 mm -1 , P= 0.007). V sub/MLA 2 was significantly elevated in patients with chest pain compared to those without in the pLAD (473.75 ± 227.38 mm -1 vs. 314.24 ± 110.74 mm -1 , P = 0.018) and the pLCx (417.04 ± 182.65 mm -1 vs. 275.29 ± 112.97 mm -1 , P = 0.044).
Conclusion
CCTA-derived V sub/MLA 2 may more accurately reflect the balance between myocardial blood supply and demand, offering insights into the occurrence of demand angina in patients with HCM without obstructive coronary artery disease.
6.A Recurrent Nocardial Corneal Ulcer
Han-Young CHUNG ; Tae-Eun LEE ; In-Cheon YOU
Journal of the Korean Ophthalmological Society 2025;66(1):70-74
Purpose:
To present a case of recurrent Nocardia keratitis following the use of topical steroids.Case summary: A 57-year-old man presented with decreased visual acuity and conjunctival injection in the right eye which began 15 days prior. Slit-lamp examination revealed epithelial defects smaller than the circular infiltrate and empirical topical treatment was initiated. Since the corneal lesion improved with a therapeutic contact lens and topical antibiotics, a steroid eye drop was added. After 7 days, the corneal infiltrate worsened in a wreath-like pattern with a positive result on a KOH (potassium hydroxide) smear, and antifungal eye drops were started. However, Nocardia species was confirmed on the 9th day of culture. While complete epithelial regeneration was achieved after 10 days using amikacin eye drops, steroid eye drops were reused to reduce the corneal haze. Twenty days later, the corneal infiltrate and epithelial defects reappeared adjacent to the initial opacity, and a culture confirmed Nocardia. Gradual improvement was achieved with amikacin eye drops and oral Septrin. Ultimately, a combination of moxifloxacin, tobramycin, and bromfenac eye drops was tapered over several months, resulting in healing with mild opacity.
Conclusions
Nocardia keratitis commonly arises from trauma involving soil, progresses slowly, and is often misdiagnosed as a fungal infection. While amikacin eye drops proved effective, prolonged topical treatment is essential. Early steroid use should be considered cautiously, as it may lead to recurrence and worsening of the corneal lesion.
7.Probiotic-Derived P8 Protein: Promoting Proliferation and Migration in Stem Cells and Keratinocytes
Soo Bin JANG ; Yoojung KIM ; Han Cheol YEO ; Geun-Ho KANG ; Byung Chull AN ; Yongku RYU ; Myung-Jun CHUNG ; Ssang-Goo CHO
International Journal of Stem Cells 2025;18(1):87-98
Probiotics exert various effects on the body and provide different health benefits. Previous reports have demonstrated that the P8 protein (P8), isolated from Lactobacillus rhamnosus, has anticancer properties. However, its efficacy in stem cells and normal cells has not been reported. In this study, the effect of P8 on cell proliferation and wound healing was evaluated, investigating its underlying mechanism. Based on scratch assay results, we demonstrated that P8 treatment significantly increases wound healing by activating the cell cycle and promoting stem cell stemness.Cellular mechanisms were further investigated by culturing stem cells in a medium containing Lactobacillus-derived P8 protein, revealing its promotion of cell proliferation and migration. Also, it is found that P8 enhances the expression of stemness markers, such as OCT4 and SOX2, along with activation of the mitogen-activated protein kinase (MAPK) signaling and Hippo pathways. These results indicate that P8 can promote cell growth by increasing stem cell proliferation, migration, and stemness in a manner associated with MAPK and Hippo signaling, which could contribute to the increased wound healing after P8 treatment. Furthermore, P8 could promote wound healing in keratinocytes by activating the MAPK signaling pathways. These results suggest that P8 might be a promising candidate to enhance stem cell culture efficiency by activating cell proliferation, and enhance therapeutic effects in skin diseases.
8.Coronary Artery Dimension-Adjusted Subtended Myocardial Mass Obtained With Coronary CT Angiography as a Potential Biomarker of Myocardial Ischemia in Patients With Hypertrophic Cardiomyopathy
Jung Han WOO ; Hyewon CHOI ; Min Jae CHA
Korean Journal of Radiology 2025;26(4):324-332
Objective:
To compare coronary artery dimension-adjusted subtended myocardial mass between patients with hypertrophic cardiomyopathy (HCM) and a normal population without detectable atherosclerosis, and between HCM patients with and without chest pain.
Materials and Methods:
Twenty-five patients with HCM but no detectable atherosclerosis on coronary computed tomography angiography (CCTA) were included in the study. This group comprised 14 patients with chest pain and 11 patients without chest pain. They were matched with 25 healthy participants based on sex, age, coronary dominance pattern, and body surface area. The minimal lumen area (MLA) and subtended myocardial volume (V sub) were assessed in the left main (LM), proximal left anterior descending (pLAD), proximal left circumflex (pLCx), and proximal right coronary (pRCA) arteries. Additionally, an index of the subtended myocardial mass adjusted for the MLA, calculated as V sub/MLA 2 , was determined.
Results:
MLA was significantly larger in patients with HCM compared to the control group in LM (20.93 ± 6.31 mm 2 vs.15.24 ± 3.90 mm 2 , P< 0.001), pLAD (14.28 ± 3.55 mm 2 vs. 11.36 ± 2.07 mm 2, P = 0.001), pLCx (10.94 ± 3.60 mm 2 vs. 9.15 ± 2.93 mm 2 , P = 0.045), and pRCA (13.41 ± 4.85 mm 2 vs. 11.22 ± 3.20 mm 2 , P = 0.018). Despite an increase in coronary luminal area, patients with HCM exhibited significantly higher V sub/MLA 2 compared to the control group in both the pLAD (403.56 ± 200.35 mm -1 vs. 241.70 ± 85.87 mm -1 , P < 0.001) and the pRCA (186.06 ± 95.07 mm -1 vs. 125.07 ± 70.18 mm -1 , P= 0.007). V sub/MLA 2 was significantly elevated in patients with chest pain compared to those without in the pLAD (473.75 ± 227.38 mm -1 vs. 314.24 ± 110.74 mm -1 , P = 0.018) and the pLCx (417.04 ± 182.65 mm -1 vs. 275.29 ± 112.97 mm -1 , P = 0.044).
Conclusion
CCTA-derived V sub/MLA 2 may more accurately reflect the balance between myocardial blood supply and demand, offering insights into the occurrence of demand angina in patients with HCM without obstructive coronary artery disease.
9.Temperamental and Neurocognitive Predictors in Korean Basketball League Draft Selection
Kyungjin OH ; Jea Woog LEE ; Kyung Doo KANG ; Doug Hyun HAN
Psychiatry Investigation 2025;22(1):66-74
Objective:
This study hypothesized that physical status, temperament and characteristics, and neurocognitive functions of basketball players could predict the result of Korean Basketball League (KBL) draft selection.
Methods:
We recruited the number of 89 college elite basketball players (KBL selection, n=44; non-KBL selection, n=45), and the number of 82 age-matched healthy comparison subjects who major in sports education in college. All participants were assessed with the Temperament and Character Inventory, Sports Anxiety Scales, Beck Depression Inventory, Perceived Stress Scale-10, Trail Making Test, and Computerized Neuro-cognitive Test for Emotional Perception and Mental Rotation.
Results:
Current results showed that physical status, temperament and characteristics, and neurocognitive functions of college basketball players could predict the KBL draft selection. Among temperament and characteristics, novelty seeking and reward dependence were associated with KBL draft selection. The basketball performances including average scores and average rebound were associated with Emotional Perception and Mental Rotation.
Conclusion
In order to be a good basketball player for a long time, it was confirmed that temperamental factors and neurocognitive factors were very closely related. Furthermore, it is also judged that these results can be used as basic data to predict potential professional basketball players.
10.Brain Activation in Response to Literature-Related Activities
Seungpil JEONG ; Ji Sun HONG ; Doug Hyun HAN
Psychiatry Investigation 2025;22(5):574-582
Objective:
A humanities-based approach to understanding the brain can yield valuable insights, advancing neuroscience and enhancing mental, emotional, and social well-being. This study was aimed at exploring how engagement in literature-related activities stimulates brain activity in the prefrontal cortex.
Methods:
We recruited 24 healthy male participants aged 20 to 29 years. They completed clinical scales assessing depression, anxiety, attention, and humanistic knowledge. They also performed six tasks comprising various literature-related cognitive challenges while hemodynamic changes in their frontal cortices were measured using functional near-infrared spectroscopy.
Results:
Task 1 (word memory and recognition) increased activation in the ventrolateral prefrontal cortex (VLPFC), as did Task 2 (emotional words classification), which also elevated activity in the left orbitofrontal cortex (OFC). Task 3 (understanding context) increased activation in the dorsolateral PFC (DLPFC). Tasks 4 (interpersonal relationship) and 5 (listening, memory, understanding, and expression) drove similar increases in the frontopolar and DLPFC regions. Task 6 (creative activities using characters and items) significantly activated multiple regions, including the right and left VLPFC and OFC. Humanistic knowledge scores were positively correlated with left and right DLPFC activation in Tasks 3 and 5, respectively. Conversely, Task 6 showed negative correlations between attention-deficit/hyperactivity disorder scores and both right DLPFC and right OFC activation.
Conclusion
This study identified key brain regions involved in literature activities. Complex activities (semantic processing, understanding and creative expression, decision-making and emotional regulation, etc.) stimulated various regions of prefrontal cortices, including the VLPFC, DLPFC, and OFC.

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