1.Effects of the timing of testicular sperm retrieval on intracytoplasmic sperm injection outcomes
Tae Ho HWANG ; Jae Kyun PARK ; Dong Hyuk SHIN ; Won Hee LEE ; Ye Eun KIM ; Yohan HEO ; Tae Ho LEE ; Seung-Ryeol LEE ; Seung-Hun SONG
Clinical and Experimental Reproductive Medicine 2026;53(2):115-120
Objective:
This study aimed to evaluate reproductive outcomes according to the timing of testicular sperm retrieval.
Methods:
The study included 282 infertile couples divided into three groups: group A (freeze-thawed testicular sperm extraction [TESE] sperm, n=233), group B (fresh TESE sperm collected 1 day before ovum pickup, n=22), and group C (fresh TESE sperm collected on the same day as ovum pickup, n=27). The indications for TESE were surgically uncorrectable azoospermia or ejaculation failure, often accompanied by medical comorbidities such as diabetes mellitus and spinal cord injury. The outcome parameters assessed were fertilization rates, embryo quality, and clinical pregnancy rates.
Results:
The mean paternal age was 36.8±5.7 years, and the mean maternal age was 32.6±3.5 years. The mean duration of infertility was 2.9±1.8 years. The fertilization rates were 70.7%, 78.9%, and 73.0% for groups A, B, and C, respectively (p=0.047). The percentages of good-quality embryos were 68.2%, 65.3%, and 48.4%, respectively (p=0.007); specifically, the percentage of good-quality embryos was significantly lower in group C compared with the other two groups. Clinical pregnancy rates per transfer were similar at 51.1%, 50.0%, and 48.1% (p=0.958), with no differences observed in miscarriage rates.
Conclusion
Testicular sperm retrieval can be safely performed 1 day before ovum pickup, resulting in favorable fertility outcomes.
2.Proteomic Profiling of Exosomes Derived from Endometrial Stem Cells and Adipose-Derived Stem Cells
Jungwon PARK ; Jeongmin LEE ; Yeon-Suk KIM ; Yohan OH
International Journal of Stem Cells 2026;19(1):102-112
Endometrial stem cells (EnSCs) are mesenchymal stem cells (MSCs) derived from endometrial tissue and serve as a valuable MSC source, as they are naturally replenished during menstruation. Exosomes, vesicles secreted by cells, contain various biomolecules such as proteins and nucleic acids and play crucial roles in intracellular communication, protein and nucleic acid metabolism, immune response regulation, and antigen presentation. This study investigated the protein profiles of EnSC-derived exosomes isolated from the endometrium of menstruating women and compared them with those of adipose-derived stem cell (ASC)-derived exosomes. After isolating EnSCs and ASCs, MSC characteristics were confirmed, and the purified exosomes were analyzed to determine their individual protein compositions.EnSCs, which can be obtained through non-invasive methods, exhibit multipotency similar to other MSCs and demonstrate rapid proliferation in vitro. Proteomic analysis of exosomal proteins revealed that 236 proteins were significantly more abundant in EnSC-derived exosomes than in ASC-derived exosomes, whereas 84 proteins were significantly more abundant in ASC-derived exosomes than in EnSC-derived exosomes. These findings indicate that EnSC-derived exosomes contain unique proteins compared to ASC-derived exosomes, as demonstrated through proteomic profiling. While further clinical studies are required, EnSCs hold promise as a potential therapeutic option in regenerative medicine, similar to current cell therapy products under development.
3.Combined Fixation of K-Wires and Static External Fixators for Pilon-Type Fractures of Finger Proximal Interphalangeal Joints
Hyuk Min KWON ; SeongJu CHOI ; Yohan LEE ; Soobeom LIM
The Journal of the Korean Orthopaedic Association 2025;60(4):277-285
Purpose:
This paper reports the clinical and radiological outcomes of a combined fixation method using K-wire fixation and static external fixation in pilon fractures of the proximal interphalangeal joint (PIPJ).
Materials and Methods:
From March 2022 to February 2024, patients treated at a single institution for pilon fractures of the proximal phalanx using K-wire fixation and static external fixation were investigated. Patients who were followed up for more than 4 months were selected. The exclusion criteria were those with previous fractures or surgeries in the same area, vascular or nerve injuries, or underlying conditions such as rheumatoid arthritis were excluded. Six patients were included in the study. Clinical evaluations included assessments of the range of motion (ROM) of the PIPJ and pain scores using the visual analogue scale (VAS). Radiological evaluations assessed the congruity of the joint and joint space. Postoperative complications were also investigated.
Results:
At the final follow-up, the mean ROM of the PIPJ, extension lag, and VAS pain score were 94° (flexion range: 80°–110°), the mean extension lag was 5.0° (extension range: 0°–10°), and 0.7, repectively. The radiographs confirmed the proper congruity of the joint and joint space. One patient developed stiffness in the distal interphalangeal joint with a ROM of 35° (-20° to 55°), but no functional issues with the hand were noted. No complications such as infections or complex regional pain syndrome, were encountered, and no patients required additional surgery.
Conclusion
The combined fixation method using K-wire fixation and static external fixation appears to be an effective and safe surgical method for treating pilon fractures of the PIPJ.
4.Plasma presepsin for mortality prediction in patients with sepsis-associated acute kidney injury requiring continuous kidney replacement therapy
Gi-Beop LEE ; Ji Won LEE ; Se-Hee YOON ; Won Min HWANG ; Sung-Ro YUN ; Dong Hoon KOH ; Yohan PARK
Kidney Research and Clinical Practice 2024;43(4):457-468
The reliability of presepsin as a biomarker of sepsis may be reduced in patients with acute kidney injury (AKI) requiring continuous kidney replacement therapy (CKRT). This study analyzed the utility of plasma presepsin values in predicting mortality in patients with AKI requiring CKRT, particularly those with sepsis-associated AKI. Methods: This single-center retrospective study included 57 patients who underwent CKRT, with plasma presepsin measurements, from April 2022 to March 2023; 35 had sepsis-associated AKI. The predictive values of plasma presepsin, as well as Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores, for 28-day mortality were analyzed using receiver operating characteristic curves. Multivariate Cox regression analysis was performed to identify risk factors for 28-day mortality in the sepsis-associated AKI subgroup. Results: Overall, plasma presepsin showed a lower area under the curve value (0.636; 95% confidence interval [CI], 0.491–0.781) than the APACHE II (0.663; 95% CI, 0.521–0.804) and SOFA (0.731; 95% CI, 0.599–0.863) scores did. However, in sepsis-associated AKI, the area under the curve increased to 0.799 (95% CI, 0.653–0.946), which was higher than that of the APACHE II (0.638; 95% CI, 0.450–0.826) and SOFA (0.697; 95% CI, 0.519–0.875) scores. In the multivariate Cox regression analysis, a high presepsin level was an independent risk factor for 28-day mortality in sepsis-associated AKI (hazard ratio, 3.437; p = 0.03). Conclusion: Presepsin is a potential prognostic marker in patients with sepsis-associated AKI requiring CKRT.
5.CORRIGENDUM: Epigenetic modulation inhibits epithelial-mesenchymal transition-driven fibrogenesis and enhances characteristics of chemically-derived hepatic progenitors
Michael ADISASMITA ; Hyomin K LEE ; Yohan AN ; Myounghoi KIM ; Michael Girma MAMO ; Junho K. HUR ; Dongho CHOI ; Ji Hyun SHIN ; Yun Kyung JUNG
Annals of Surgical Treatment and Research 2024;106(6):370-370
6.Epigenetic modulation inhibits epithelial-mesenchymal transition-driven fibrogenesis and enhances characteristics of chemically-derived hepatic progenitors
Michael ADISASMITA ; Hyomin K LEE ; Yohan AN ; Myounghoi KIM ; Michael Girma MAMO ; Junho K. HUR ; Dongho CHOI ; Ji Hyun SHIN ; Yun Kyung JUNG
Annals of Surgical Treatment and Research 2024;106(5):274-283
Purpose:
One of the novel cell sources of cell-based liver regenerative medicine is human chemically-derived hepatic progenitors (hCdHs). We previously established this cell by direct hepatocyte reprogramming with a combination of small molecules (hepatocyte growth factor, A83-01, CHIR99021). However, there have been several issues concerning the cell’s stability and maintenance, namely the occurrences of epithelial-mesenchymal transition (EMT) that develop fibrotic phenotypes, resulting in the loss of hepatic progenitor characteristics. These hepatic progenitor attributes are thought to be regulated by SOX9, a transcription factor essential for hepatic progenitor cells and cholangiocytes.
Methods:
To suppress the fibrotic phenotype and improve our long-term hCdHs culture technology, we utilized the epigenetic modulating drugs DNA methyltransferase inhibitor (5-azacytidine) and histone deacetylase inhibitor (sodium butyrate) that have been reported to suppress and revert hepatic fibrosis. To confirm the essential role of SOX9 to our cell, we used clustered regularly interspaced short palindromic repeats-interference (CRISPRi) to repress the SOX9 expression.
Results:
The treatment of only 5-azacytidine significantly reduces the fibrosis/mesenchymal marker and EMT-related transcription factor expression level in the early passages. Interestingly, this treatment also increased the hepatic progenitor markers expression, even during the reprogramming phase. Then, we confirmed the essential role of SOX9 by repressing the SOX9 expression with CRISPRi which resulted in the downregulation of several essential hepatic progenitor cell markers.
Conclusion
These results highlight the capacity of 5-azacytidine to inhibit EMT-driven hepatic fibrosis and the significance of SOX9 on hepatic progenitor cell stemness properties.
7.Comparison of Synergistic Sedation with Midazolam and Propofol Versus Midazolam and Pethidine in Colonoscopies: A Prospective, Randomized Controlled Study
Jae Woong LIM ; Min Jae KIM ; Gang Han LEE ; Dae Sol KIM ; Sang Hyuk JUNG ; Yu Yeon KIM ; Jin Won KIM ; Yohan LEE ; Hyun Soo KIM ; Seon Young PARK ; Dong Hyun KIM
Chonnam Medical Journal 2024;60(3):192-197
Colonoscopy is a key procedure for the early detection of colorectal cancer. Despite its importance, the discomfort associated with colonoscopy often requires sedation, and the ideal sedation regimen remains to be determined. In this prospective randomized controlled trial, patients scheduled for colonoscopy were randomly assigned to two different sedation protocols. Group A received a combination of midazolam and propofol, while group B was given midazolam and pethidine. The study analyzed data from 51 patients, with 23 in group A and 28 in group B. The incidence of adverse events was similar across both groups. Additionally, no significant differences were observed in cecal intubation times or total procedure durations. Notably, group A had a lower frequency of required postural changes (1.0±0.7 vs. 1.5±0.7, p=0.02) and a reduced rate of manual compression (52.2% vs. 82.1%, p=0.02). There were no significant differences between the groups regarding subjective pain or overall satisfaction. Both sedation regimens were found to be safe and effective. The midazolam and propofol combination was associated with a smoother procedure, evidenced by fewer postural adjustments and less manual compression needed during colonoscopy.
8.Simple and Safe Soft-Tissue Coverage Technique Using the Bipedicled Flap in the Lower Leg
Dong Uk JIN ; Yohan LEE ; Young Ho LEE
Clinics in Orthopedic Surgery 2024;16(5):782-789
Background:
Skin and soft-tissue defects in the lower legs present significant challenges for surgeons, especially when tendons, bones, or implants are exposed. In such cases, simple dressings or skin grafts are insufficient, necessitating flap surgery.The bipedicled flap is a simpler and more reliable method with a high success rate compared to other flaps, showing minimal flap failures. This study aimed to examine the advantages and limitations of using a bipedicled flap for soft-tissue reconstruction in the lower legs.
Methods:
This retrospective study reviewed medical records from January 2013 to May 2020, involving 10 bipedicled flaps performed on the lower legs. The study included 5 male and 5 female patients, with an average age of 54.5 years. The defects were due to various causes, including trauma, tumor surgery, postoperative complications such as dehiscence and skin necrosis, and chronic osteomyelitis. The size of the defects ranged from 4 × 3 cm to 16 × 13 cm. The outcomes assessed included flap viability, postoperative complications, and patient satisfaction. Patient satisfaction was assessed on a 15-point scale, evaluating appearance, function, and sensation with up to 5 points each, and categorizing scores as poor (1–3), below average (4–6), average (7–9), good (10–12), and excellent (13–15).
Results:
All flaps were successfully performed, and there were no cases showing any special complications. Patient satisfaction following the operation was excellent in 3 patients, good in 6 patients, and average in 1 patient, with an overall average score of 11.5 (good) out of 15 among the 10 patients evaluated.
Conclusions
The bipedicled flap is a simple and secure method for treating soft-tissue defects in the lower legs. Therefore, this technique can be considered as one of the viable options for treating such defects.
9.Association Between Oral Health and Airflow Limitation: Analysis Using a Nationwide Survey in Korea
Sun-Hyung KIM ; Seonhye GU ; Jung-Ae KIM ; YoHan IM ; Jun Yeun CHO ; Youlim KIM ; Yoon Mi SHIN ; Eung-Gook KIM ; Ki Man LEE ; Kang Hyeon CHOE ; Hyun LEE ; Bumhee YANG
Journal of Korean Medical Science 2023;38(31):e241-
Background:
Although poor oral health is a common comorbidity in individuals with airflow limitation (AFL), few studies have comprehensively evaluated this association. Furthermore, the association between oral health and the severity of AFL has not been well elucidated.
Methods:
Using a population-based nationwide survey, we classified individuals according to the presence or absence of AFL defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity < 0.7. Using multivariable logistic regression analyses, we evaluated the association between AFL severity and the number of remaining teeth; the presence of periodontitis; the Decayed, Missing, and Filled Teeth (DMFT) index; and denture wearing.
Results:
Among the 31,839 participants, 14% had AFL. Compared with the control group, the AFL group had a higher proportion of periodontitis (88.8% vs. 79.4%), complete denture (6.2% vs. 1.6%), and high DMFT index (37.3% vs. 27.8%) (P < 0.001 for all). In multivariable analyses, denture status: removable partial denture (adjusted odds ratio [aOR], 1.12; 95% confidence interval [95% CI], 1.04–1.20) and complete denture (aOR, 1.52; 95% CI, 1.01– 2.05), high DMFT index (aOR, 1.13; 95% CI, 1.02–1.24), and fewer permanent teeth (0–19;aOR, 1.32; 95% CI, 1.12–1.52) were significantly associated with AFL. Furthermore, those with severe to very severe AFL had a significantly higher proportion of complete denture (aOR, 2.41; 95% CI, 1.11–3.71) and fewer remaining teeth (0–19; aOR, 2.29; 95% CI, 1.57–3.01).
Conclusion
Denture wearing, high DMFT index, and fewer permanent teeth are significantly associated with AFL. Furthermore, a reduced number of permanent teeth (0–19) was significantly related to the severity of AFL. Therefore, physicians should pay attention to oral health in managing patients with AFL, such as chronic obstructive pulmonary disease.
10.Korean vs. Western Exercise Capacity Nomograms for Korean Patients With Cardiovascular Disease
Soohyung PARK ; Byambakhand BATTUMUR ; Seo Yeon YOON ; Yohan LEE ; Se hyun PARK ; Kyuho LEE ; Seungmin BACK ; Jieun LEE ; Dong Oh KANG ; Jah Yeon CHOI ; Seung-Young ROH ; Jin Oh NA ; Cheol Ung CHOI ; Jin Won KIM ; Seung-Woon RHA ; Chang Gyu PARK ; Eung Ju KIM
Journal of Korean Medical Science 2023;38(23):e179-
Background:
Exercise capacity is known to be an independent predictor of cardiovascular events and mortality. However, most previous studies were based on Western populations.Further study is warranted for Asian patients according to ethnic or national standards. We aimed to compare prognostic values of Korean and Western nomograms for exercise capacity in Korean patients with cardiovascular disease (CVD).
Methods:
In this retrospective cohort study, we enrolled 1,178 patients (62 ± 11 years;78% male) between June 2015 and May 2020, who were referred for cardiopulmonary exercise testing in our cardiac rehabilitation program. The median follow-up period was 1.6 years. Exercise capacity was measured in metabolic equivalents by direct gas exchange method during the treadmill test. The nomogram for exercise capacity from healthy Korean individuals and a previous landmark Western study was used to determine the percentage of predicted exercise capacity. The primary endpoint was the composite of major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, repeat revascularization, stroke and hospitalization for heart failure).
Results:
A multivariate analysis showed that the risk of primary endpoint was more than double (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.10–4.40) in the patients with lower exercise capacity (< 85% of predicted) by Korean nomogram. The lower exercise capacity was one of the strong independent predictors along with left ventricular ejection fraction, age, and level of hemoglobin. However, the lower exercise capacity by Western nomogram could not predict the primary endpoint (HR, 1.33; 95% CI, 0.85–2.10).
Conclusion
Korean patients with CVD with lower exercise capacity have higher risk of MACE.Considering inter-ethnic differences in cardiorespiratory fitness, the Korean nomogram provides more suitable reference values than the Western nomogram to determine lower exercise capacity and predict cardiovascular events in Korean patients with CVD.

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