1.Comparison of Well-Differentiated Liposarcoma and Lipoma
Si Woon KIM ; Jeung Il KIM ; In Sook LEE ; You Seon SONG ; Kyung Un CHOI
The Journal of the Korean Orthopaedic Association 2026;61(1):65-71
Purpose:
This study aimed to differentiate well-differentiated liposarcoma (WDLPS) from lipoma using the magnetic resonance imaging (MRI) findings and improve the preoperative diagnostic accuracy between the two tumors. Although lipoma is a benign tumor that does not necessarily require surgical intervention, WDLPS exhibits local aggressiveness and typically necessitates surgical excision, making its differentiation clinically significant.
Materials and Methods:
Among 363 patients diagnosed with lipoma or WDLPS at the authors’ institution between January 2013 and April 2022, 45 patients with lipoma and 15 with WDLPS were selected using propensity score matching based on age and sex. The following six MRI features were analyzed: tumor size, shape, septal thickness, tumor depth, fat content ratio, and the presence of nodular non-fatty tissue components. The sensitivity and specificity of each feature were evaluated.
Results:
Among the MRI features, the fat content ratio (specificity 95%) and the presence of nodular non-fatty tissue components (specificity 98%) were useful for excluding WDLPS, but their sensitivities were relatively low (46% and 27%). The sensitivities of other features, such as tumor size, shape, septal thickness, and depth, ranged from 47% to 67%, suggesting that MRI alone has limitations in reliably distinguishing the two tumors. In addition, fat content ratios below 75% and the presence of nodular non-fatty tissue components were significantly more common in WDLPS than in lipoma.
Conclusion
The MRI findings can serve as a useful tool for excluding WDLPS when differentiating it from lipoma. Nevertheless, MRI alone has limitations in achieving a definitive diagnosis because of the low sensitivity of individual features. Therefore, additional approaches such as radiomics analysis, artificial intelligence algorithms, and multicenter studies, are needed to improve the diagnostic accuracy and establish personalized treatment strategies.
2.Impact of COVID-19 on testicular torsion:A single-center retrospective study from a children’s hospital
Kota FUJIMOTO ; Beom Yong RHO ; Si Wook LEE ; Jae Ok BAEK ; Yong Seung LEE ; Sang Woon KIM
Investigative and Clinical Urology 2026;67(1):72-78
Purpose:
Testicular torsion is a urological emergency necessitating immediate surgical intervention. However, the altered medical environment during the coronavirus disease 2019 (COVID-19) pandemic posed several challenges and the current study aimed to analyze its effects on the treatment of pediatric testicular torsion cases.
Materials and Methods:
We retrospectively analyzed 47 pediatric patients diagnosed with testicular torsion at Severance Children's Hospital from 2009 to 2022. Patients were categorized into pre–COVID-19 (n=38) and COVID-19 (n=8) groups. Data were collected for each patient, and the differences between the two groups were statistically analyzed.
Results:
The patients’ median age was from 13 years (range, 1–19 years) to 13 years (range, 1–16 years) between the pre–COVID-19 and COVID-19 period (p=0.309). The analysis revealed a significant difference between the pre–COVID-19 and COVID-19 groups in the time from symptom onset to emergency department arrival (6.4 hours [0.7–120.0] vs. 20.0 hours [1.3–288.0], p=0.031) and the time from symptom onset to surgery start (19.5 hours [4.5–124.3] vs. 28.5 hours [6.1–293.4], p=0.047). The median postoperative size of the affected testis was 9.8 mL (range, 2.0–13.9 mL) during the COVID-19 period, compared to 1.6 mL (range, 0.1–7.3 mL) in pre–COVID-19 period (p=0.012). The testicular volume ratio (affected/unaffected) was used to evaluate outcomes across patients with varying ages and testicular sizes.
Conclusions
The current study shows that pandemic-related delays in treatment may worsen ischemic injury in testicular torsion, emphasizing the importance of timely intervention even during global crises.
3.The Effect of Nerve Growth Factor on Cartilage Fibrosis and Hypertrophy during In Vitro Chondrogenesis Using Induced Pluripotent Stem Cells
Se In JUNG ; Si Hwa CHOI ; Jang-Woon KIM ; Jooyoung LIM ; Yeri Alice RIM ; Ji Hyeon JU
International Journal of Stem Cells 2025;18(1):59-71
Nerve growth factor (NGF) is a neurotrophic factor usually involved in the survival, differentiation, and growth of sensory neurons and nociceptive function. Yet, it has been suggested to play a role in the pathogenesis of osteoarthritis (OA). Previous studies suggested a possible relationship between NGF and OA; however, the underlying mechanisms remain unknown. Therefore, we investigated the impact of NGF in chondrogenesis using human induced pluripotent stem cells (hiPSCs)-derived chondrogenic pellets. To investigate how NGF affects the cartilage tissue, hiPSC-derived chondrogenic pellets were treated with NGF on day 3 of differentiation, expression of chondrogenic, hypertrophic, and fibrotic markers was confirmed. Also, inflammatory cytokine arrays were performed using the culture medium of the NGF treated chondrogenic pellets. As a result, NGF treatment decreased the expression of pro-chondrogenic markers by approximately 2∼4 times, and hypertrophic (pro-osteogenic) markers and fibrotic markers were increased by approximately 3-fold or more in the NGF-treated cartilaginous pellets. In addition, angiogenesis was upregulated by approximately 4-fold or more, bone formation by more than 2-fold, and matrix metalloproteinase induction by more than 2-fold. These inflammatory cytokine array were using the NGF-treated chondrogenic pellet cultured medium.Furthermore, it was confirmed by Western blot to be related to the induction of the glycogen synthase kinase-3 beta (GSK3β) pathway by NGF. In Conclusions, these findings provide valuable insights into the multifaceted role of NGF in cartilage hypertrophy and fibrosis, which might play a critical role in OA progression.
4.The Effect of Nerve Growth Factor on Cartilage Fibrosis and Hypertrophy during In Vitro Chondrogenesis Using Induced Pluripotent Stem Cells
Se In JUNG ; Si Hwa CHOI ; Jang-Woon KIM ; Jooyoung LIM ; Yeri Alice RIM ; Ji Hyeon JU
International Journal of Stem Cells 2025;18(1):59-71
Nerve growth factor (NGF) is a neurotrophic factor usually involved in the survival, differentiation, and growth of sensory neurons and nociceptive function. Yet, it has been suggested to play a role in the pathogenesis of osteoarthritis (OA). Previous studies suggested a possible relationship between NGF and OA; however, the underlying mechanisms remain unknown. Therefore, we investigated the impact of NGF in chondrogenesis using human induced pluripotent stem cells (hiPSCs)-derived chondrogenic pellets. To investigate how NGF affects the cartilage tissue, hiPSC-derived chondrogenic pellets were treated with NGF on day 3 of differentiation, expression of chondrogenic, hypertrophic, and fibrotic markers was confirmed. Also, inflammatory cytokine arrays were performed using the culture medium of the NGF treated chondrogenic pellets. As a result, NGF treatment decreased the expression of pro-chondrogenic markers by approximately 2∼4 times, and hypertrophic (pro-osteogenic) markers and fibrotic markers were increased by approximately 3-fold or more in the NGF-treated cartilaginous pellets. In addition, angiogenesis was upregulated by approximately 4-fold or more, bone formation by more than 2-fold, and matrix metalloproteinase induction by more than 2-fold. These inflammatory cytokine array were using the NGF-treated chondrogenic pellet cultured medium.Furthermore, it was confirmed by Western blot to be related to the induction of the glycogen synthase kinase-3 beta (GSK3β) pathway by NGF. In Conclusions, these findings provide valuable insights into the multifaceted role of NGF in cartilage hypertrophy and fibrosis, which might play a critical role in OA progression.
5.The Effect of Nerve Growth Factor on Cartilage Fibrosis and Hypertrophy during In Vitro Chondrogenesis Using Induced Pluripotent Stem Cells
Se In JUNG ; Si Hwa CHOI ; Jang-Woon KIM ; Jooyoung LIM ; Yeri Alice RIM ; Ji Hyeon JU
International Journal of Stem Cells 2025;18(1):59-71
Nerve growth factor (NGF) is a neurotrophic factor usually involved in the survival, differentiation, and growth of sensory neurons and nociceptive function. Yet, it has been suggested to play a role in the pathogenesis of osteoarthritis (OA). Previous studies suggested a possible relationship between NGF and OA; however, the underlying mechanisms remain unknown. Therefore, we investigated the impact of NGF in chondrogenesis using human induced pluripotent stem cells (hiPSCs)-derived chondrogenic pellets. To investigate how NGF affects the cartilage tissue, hiPSC-derived chondrogenic pellets were treated with NGF on day 3 of differentiation, expression of chondrogenic, hypertrophic, and fibrotic markers was confirmed. Also, inflammatory cytokine arrays were performed using the culture medium of the NGF treated chondrogenic pellets. As a result, NGF treatment decreased the expression of pro-chondrogenic markers by approximately 2∼4 times, and hypertrophic (pro-osteogenic) markers and fibrotic markers were increased by approximately 3-fold or more in the NGF-treated cartilaginous pellets. In addition, angiogenesis was upregulated by approximately 4-fold or more, bone formation by more than 2-fold, and matrix metalloproteinase induction by more than 2-fold. These inflammatory cytokine array were using the NGF-treated chondrogenic pellet cultured medium.Furthermore, it was confirmed by Western blot to be related to the induction of the glycogen synthase kinase-3 beta (GSK3β) pathway by NGF. In Conclusions, these findings provide valuable insights into the multifaceted role of NGF in cartilage hypertrophy and fibrosis, which might play a critical role in OA progression.
6.Artificial Intelligence-Guided Mobile Telerehabilitation for Individuals With Cognitive Impairment: A Feasibility Study
Suebeen KIM ; Doo Young KIM ; Si-Woon PARK ; Namo JEON ; Taeksoo JEONG ; Min-Soo KANG ; Sangwook PARK
Annals of Rehabilitation Medicine 2025;49(6):371-380
Objective:
To test the feasibility and usability of an artificial intelligence (AI)-guided mobile cognitive telerehabilitation program for patients with stroke or older adults with mild cognitive impairment (MCI).
Methods:
Thirteen participants with cognitive impairment (Mini-Mental State Examination [MMSE] score≤26; nine with stroke and four with MCI) were enrolled in the study. Each participant was provided with an AI-guided mobile cognitive rehabilitation program (Zenicog®). Participants were instructed to complete 24 sessions within 6 weeks, and those with sufficient adherence (≥70%, 17 sessions) were included in the analysis. Cognitive assessments included the MMSE, digit span, and Trail Making Tests A & B. The usability questionnaire investigated equitable use and flexibility in use, simple and intuitive use, perceptible information, tolerance for error, low physical effort, size and space for use, overall product quality, overall satisfaction.
Results:
Eleven participants completed the study, and 10 participants met adherence criteria. The MMSE score increased significantly from 24.00 [21.00, 25.75] at baseline to 27.50 [26.00, 28.75] after intervention. The overall product quality (Likert scale: 1–5) score was 4.00±0.87. The lowest score in the usability questionnaire was for tolerance for error. Female participants and participants with <12 years’ education gave lower scores for tolerance for error and equitable/ flexibility in use, respectively.
Conclusion
The AI-guided mobile cognitive telerehabilitation program is feasible and potentially beneficial for improving cognitive function in patients with stroke or older adults with MCI. Individuals who are less familiar with electronic devices require special consideration to improve their usability.
7.Bulk Modification with Inorganic Particles and Immobilization of Extracellular Vesicles onto PDO Composite for Facial Rejuvenation
Seung-Woon BAEK ; Dong Min KIM ; Semi LEE ; Duck Hyun SONG ; Gi-Min PARK ; Chun Gwon PARK ; Dong Keun HAN
Tissue Engineering and Regenerative Medicine 2024;21(2):199-208
BACKGROUND:
The skin, a vital organ protecting against microorganisms and dehydration, undergoes structural decline with aging, leading to visible issues such as wrinkles and sagging. Reduced blood vessels exacerbate vulnerability, hindering optimal cellular function and compromising skin health. Polydioxanone (PDO) biomaterials address aging concerns but produce acidic byproducts, causing inflammation. Inorganic particles and nitric oxide (NO) play crucial roles in inhibiting inflammation and promoting skin regeneration. Stem cell-derived extracellular vesicles (EVs) contribute to intercellular communication, offering the potential to enhance cell functions. The study proposes a method to enhance PDO-based medical devices by incorporating inorganic particles and immobilizing EVs, focusing on facial rejuvenation, anti-inflammatory response, collagen formation, and angiogenesis.METHOD: PDO composites with inorganic particles such as magnesium hydroxide (MH) and zinc oxide (ZO) were prepared and followed by EV immobilization. Comprehensive characterization included biocompatibility, anti-inflammation, collagen formation ability, and angiogenesis ability.
RESULTS:
Bulk-modified PDO composites demonstrated even dispersion of inorganic particles, pH neutralization, and enhanced biocompatibility. EVs immobilized on the composite surface exhibited spherical morphology. Inflammationrelated gene expressions decreased, emphasizing anti-inflammatory effects. Collagen-related gene and protein expressions increased, showcasing collagen formation ability. In addition, angiogenic capabilities were notably improved, indicating potential for skin rejuvenation.
CONCLUSION
The study successfully developed and characterized PDO composites with inorganic particles and EVs, demonstrating promising attributes for medical applications. These composites exhibit biocompatibility, anti-inflammatory properties, collagen formation ability, and angiogenic potential, suggesting their utility in skin rejuvenation and tissue engineering. Further research and clinical validation are essential.
8.Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD): A Cohort for Dementia Research and Ethnic-Specific Insights
Hyemin JANG ; Daeun SHIN ; Yeshin KIM ; Ko Woon KIM ; Juyoun LEE ; Jun Pyo KIM ; Hee Jin KIM ; Soo Hyun CHO ; Si Eun KIM ; Duk. L. NA ; Sang Won SEO ; On behalf of the K-ROAD Study Groups
Dementia and Neurocognitive Disorders 2024;23(4):212-223
Background:
and Purpose: Dementia, particularly Alzheimer’s disease, is a significant global health concern, with early diagnosis and treatment development being critical goals. While numerous cohorts have advanced dementia research, there is a lack of comprehensive data on ethnic differences, particularly for the Korean population. The Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD) aims to establish a large-scale, hospital-based dementia cohort to address this gap, with a focus on understanding disease progression, developing early diagnostics, and supporting treatment advancements specific to the Korean population.
Methods:
K-ROAD comprises multiple prospective cohorts. Participants underwent clinical evaluations, neuroimaging, and biomarker analysis, with data collected on a range of clinical and genomic markers.
Results:
As of December 2023, K-ROAD has recruited over 5,800 participants, including individuals across the Alzheimer’s clinical syndrome, subcortical vascular cognitive impairment, and frontotemporal dementia spectra. Preliminary findings highlight significant ethnic differences in amyloid positivity, cognitive decline, and biomarker profiles, compared to Western cohorts.
Conclusions
The K-ROAD cohort offers a unique and critical resource for dementia research, providing insights into ethnic-specific disease characteristics and biomarker profiles. These findings will contribute to the development of personalized diagnostic and therapeutic approaches to dementia, enhancing global understanding of the disease.
9.Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD): A Cohort for Dementia Research and Ethnic-Specific Insights
Hyemin JANG ; Daeun SHIN ; Yeshin KIM ; Ko Woon KIM ; Juyoun LEE ; Jun Pyo KIM ; Hee Jin KIM ; Soo Hyun CHO ; Si Eun KIM ; Duk. L. NA ; Sang Won SEO ; On behalf of the K-ROAD Study Groups
Dementia and Neurocognitive Disorders 2024;23(4):212-223
Background:
and Purpose: Dementia, particularly Alzheimer’s disease, is a significant global health concern, with early diagnosis and treatment development being critical goals. While numerous cohorts have advanced dementia research, there is a lack of comprehensive data on ethnic differences, particularly for the Korean population. The Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD) aims to establish a large-scale, hospital-based dementia cohort to address this gap, with a focus on understanding disease progression, developing early diagnostics, and supporting treatment advancements specific to the Korean population.
Methods:
K-ROAD comprises multiple prospective cohorts. Participants underwent clinical evaluations, neuroimaging, and biomarker analysis, with data collected on a range of clinical and genomic markers.
Results:
As of December 2023, K-ROAD has recruited over 5,800 participants, including individuals across the Alzheimer’s clinical syndrome, subcortical vascular cognitive impairment, and frontotemporal dementia spectra. Preliminary findings highlight significant ethnic differences in amyloid positivity, cognitive decline, and biomarker profiles, compared to Western cohorts.
Conclusions
The K-ROAD cohort offers a unique and critical resource for dementia research, providing insights into ethnic-specific disease characteristics and biomarker profiles. These findings will contribute to the development of personalized diagnostic and therapeutic approaches to dementia, enhancing global understanding of the disease.
10.Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD): A Cohort for Dementia Research and Ethnic-Specific Insights
Hyemin JANG ; Daeun SHIN ; Yeshin KIM ; Ko Woon KIM ; Juyoun LEE ; Jun Pyo KIM ; Hee Jin KIM ; Soo Hyun CHO ; Si Eun KIM ; Duk. L. NA ; Sang Won SEO ; On behalf of the K-ROAD Study Groups
Dementia and Neurocognitive Disorders 2024;23(4):212-223
Background:
and Purpose: Dementia, particularly Alzheimer’s disease, is a significant global health concern, with early diagnosis and treatment development being critical goals. While numerous cohorts have advanced dementia research, there is a lack of comprehensive data on ethnic differences, particularly for the Korean population. The Korea-Registries to Overcome Dementia and Accelerate Dementia Research (K-ROAD) aims to establish a large-scale, hospital-based dementia cohort to address this gap, with a focus on understanding disease progression, developing early diagnostics, and supporting treatment advancements specific to the Korean population.
Methods:
K-ROAD comprises multiple prospective cohorts. Participants underwent clinical evaluations, neuroimaging, and biomarker analysis, with data collected on a range of clinical and genomic markers.
Results:
As of December 2023, K-ROAD has recruited over 5,800 participants, including individuals across the Alzheimer’s clinical syndrome, subcortical vascular cognitive impairment, and frontotemporal dementia spectra. Preliminary findings highlight significant ethnic differences in amyloid positivity, cognitive decline, and biomarker profiles, compared to Western cohorts.
Conclusions
The K-ROAD cohort offers a unique and critical resource for dementia research, providing insights into ethnic-specific disease characteristics and biomarker profiles. These findings will contribute to the development of personalized diagnostic and therapeutic approaches to dementia, enhancing global understanding of the disease.

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