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.Mutation and Functional Characteristics of MYH9 Responsible for Giant Platelet Syndromes in Korean Patients
Jin Soo HWANG ; Hee Jo BAEK ; Soo Min PARK ; Bo Ram KIM ; Hoon KOOK
Clinical Pediatric Hematology-Oncology 2026;33(1):1-12
Background:
Autosomal dominant giant platelet syndrome (GPS) is characterized by thrombocytopenia, giant platelets, and Döhle-like inclusion bodies in leukocytes.Previous studies suggest relatively preserved platelet structure and function, implicating impaired megakaryocyte fragmentation. This study aimed to identify myosin heavy chain 9 (MYH9) mutations in Korean patients with GPS and to define the associated clinical, molecular and functional characteristics.
Methods:
After detailed personal and family history taking, peripheral blood smears were reviewed for platelet size, count, and leukocyte inclusions. MYH9 mutations were analyzed in peripheral blood mononuclear cells by direct sequencing of selected exons or complementary DNA (cDNA). Computer-assisted structural modeling was performed to evaluate the functional consequences of identified mutations.
Results:
Twenty-two affected individuals from six unrelated families were diagnosed with hereditary macrothrombocytopenia consistent with GPS. The median platelet count was 59,000/L, and the mean platelet volume was markedly increased (17.8 fL). Platelets ranged from approximately half to 1.5 times the size of red blood cells.Döhle-like inclusions were observed in 25-33% of leukocytes in four families. Extrahematologic manifestations included hearing impairment (family with Ile1816Val) and renal involvement, ranging from mild proteinuria to chronic renal failure requiring renal transplantation (family with Lys373Asn). Five families harbored MYH9 mutations—Arg1933Ter, Trp33Cys (novel), Lys373Asn, Ile1816Val, and Arg1165Cys—located in exons 40, 1, 10, 37, and 26, respectively; mutations segregated with affected status.Biochemical analysis revealed decreased MYH9 in soluble fractions with increased insoluble pellets; Trp33Cys and Lys373Asn produced aberrant approximately 140 kDa bands in addition to the normal 224 kDa band. Modeling localized Trp33Cys to the proximal myosin head region implicated in actin interaction.
Conclusion
Five GPS-associated MYH9 mutations were identified, including a novel Trp33Cys variant. Altered MYH9 solubility and disturbed protein–protein interactions may contribute to disease pathogenesis.
3.Red-White Zone Involvement and Medial Meniscal Tears Are Associated with Poorer Prognosis after Arthroscopic Repair of Bucket-Handle Tears
Bo Seung BAE ; Jung Suk KIM ; Sang Hak LEE
Clinics in Orthopedic Surgery 2026;18(1):40-51
Background:
Arthroscopic repair of bucket-handle meniscal tears (BHMTs) is technically challenging owing to the complexity of the tear patterns. Compared to simpler meniscal tears, BHMTs are associated with a higher failure rate and often require subsequent meniscectomy. This study aimed to assess clinical outcomes, failure rates, and risk factors for failure following primary arthroscopic repair of BHMTs.
Methods:
Seventy-four patients (mean age, 27.2 ± 11.2 years) who underwent arthroscopic BHMT repair were included (mean follow-up period, 60.2 ± 36.0 months). Analyzed risk factors included age, sex, body mass index, chronicity, laterality, tear zone, and concomitant anterior cruciate ligament reconstruction. Clinical failure was defined as the presence of clinical symptoms consistent with a meniscus tear and the need for subsequent surgery. The Kaplan-Meier method and log-rank test were performed to compare groups classified by postoperative meniscal healing status on magnetic resonance imaging (MRI) at a mean follow-up period of 7.30 ± 1.80 months. Clinical outcomes were assessed using the Tegner activity score, Lysholm knee score, and Hospital for Special Surgery (HSS) knee score.
Results:
The clinical failure rate was 14.9% (11 / 74). Six patients underwent subtotal meniscectomy, and 5 patients underwent partial meniscectomy. Red-white zone involvement was a significant risk factor for clinical failure (odds ratio, 6.182; 95% CI, 1.093–34.950; p = 0.039). Survival analysis based on postoperative MRI findings revealed a significant difference among 3 groups (p = 0.008): the completely healed group showed a 100% survival rate (20 / 20); the partially healed group, 80% (32 / 40); and the unhealed group, 0% (0 / 5). Patients with lateral BHMTs had a significantly higher rate of complete healing than those with medial BHMTs (46.4% vs. 18.9%; p = 0.014). At the final follow-up, the non-failure group demonstrated significantly higher Tegner activity (5.1 ± 1.2 vs. 4.4 ± 0.5; p = 0.038), Lysholm knee (87.7 ± 6.2 vs. 83.2 ± 3.1; p = 0.029), and HSS knee (93.9 ± 4.7 vs. 89.6 ± 3.0; p = 0.007) scores than the failure group.
Conclusions
BHMTs involving the red-white zone or located in the medial meniscus—particularly those showing inferior early postoperative MRI healing—should be closely monitored after surgery.
4.Factors Associated with Functional Outcomes Following Combined Pelvic Ring and Acetabular Fractures: A 2-Year Retrospective Analysis
Yong-Cheol YOON ; Chang-Wug OH ; Sang-Roc HAN ; Hee-June KIM ; Joon-Woo KIM
Clinics in Orthopedic Surgery 2026;18(1):19-29
Background:
Combined pelvic ring and acetabular fractures are complex injuries associated with high morbidity. Despite advancements in surgical techniques, limited data are available on the long-term functional outcomes and associated factors. This study aimed to identify the factors associated with functional outcomes in surgically treated patients with combined pelvic ring and acetabular fractures.
Methods:
This retrospective study included 25 adult patients who underwent definitive surgical fixation for radiologically confirmed combined pelvic ring and acetabular fractures at a Level I trauma center between 2005 and 2021, with a minimum clinical and radiological follow-up of 24 months. Surgical approaches included the Kocher–Langenbeck or modified Stoppa methods, tailored to fracture morphology. Matta–Saucedo and Matta criteria assessed the pelvic ring and acetabular reduction quality, respectively. Functional outcomes at 2 years were evaluated using the Rommens–Hessmann criteria. Neurological recovery was assessed clinically and by electromyography where indicated. The association between the injury characteristics and functional recovery was evaluated using t-tests and Fisher’s exact test.
Results:
The mean patient age was 40.4 years, and 72% were male. Transverse acetabular fractures (58.6%) and anteroposterior compression pelvic ring injuries (64%) were the most common injuries. Anatomic or congruent acetabular reduction (within 2–3 mm) was achieved in 89.6% of fractures and was significantly associated with superior functional outcomes (p = 0.002). Conversely, the pelvic ring reduction quality did not significantly correlate with functional outcomes (p = 0.314). Transverse acetabular fractures (p = 0.046) and initial neurological deficits (p = 0.032) were associated with poorer recovery. Among the patients with neurological injury, 60% achieved partial or full recovery. Overall, bony union occurred in 96% of cases, with a mean time to union of 14.3 weeks. Reported complications included neurological deficits (40%) and infections (8%).
Conclusions
Functional outcomes following the surgical fixation of combined pelvic and acetabular fractures are primarily influenced by the acetabular reduction quality and neurological status at presentation. Transverse fracture patterns are complex and associated with nerve injuries, posing additional challenges. These findings emphasize the importance of precise joint reduction and early neuroassessment. Further multicenter, prospective studies are warranted to optimize the management of these complex injuries.
5.The Clinical Utility of the Cognitive Impairment Screening Test (CIST)
Hyeseon HAN ; Soyeon LIM ; Suah KIM ; Byung Hwa LEE ; Hee Jin KIM ; Juhee CHIN
Dementia and Neurocognitive Disorders 2026;25(1):42-53
Background:
and Purpose: The Cognitive Impairment Screening Test (CIST) was developed for use at the Community Dementia Reassurance Center in South Korea. This study evaluated convergent and discriminant validity of CIST, as well as its clinical utility in identifying cognitive impairment and differentiating amyloid deposition.
Methods:
We enrolled 252 participants from a hospital memory clinic (47 cognitively unimpaired [CU], 116 amnestic mild cognitive impairment, and 89 dementia). Participants completed CIST, K-MMSE-2, the Seoul Neuropsychological Screening Battery, 2nd edition (SNSB-II), and underwent amyloid positron emission tomography. To evaluate the convergent and discriminant validity of CIST, we conducted correlation analyses with SNSBII. Receiver operating characteristic analyses were used to evaluate the ability to discriminate cognitive impairment and to distinguish amyloid positivity. Areas under the curve (AUCs) for CIST and K-MMSE-2 were compared using DeLong’s test.
Results:
The total score of CIST correlated significantly with all SNSB-II subtests, and the domain scores of CIST showed stronger associations with corresponding SNSB-II subtests than with unrelated ones. Both CIST and K-MMSE-2 effectively distinguished cognitively impaired individuals from CU, with CIST demonstrating superior discrimination (AUC=0.926 vs.0.887, p=0.042). In the non-demented group, both CIST and K-MMSE-2 showed acceptable discrimination for amyloid positivity (AUC≈0.73), with high specificity but low sensitivity;however, there were no significant differences between the two tests.
Conclusions
The CIST demonstrated strong validity and discriminatory ability for detecting cognitive impairment. It also showed acceptable discrimination for amyloid positivity in non-demented participants, supporting its utility as a screening tool in both clinical and community settings.
6.A Protocol of Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ)
Geon Ha KIM ; Jung-Min PYUN ; Danbee KANG ; Sung Hoon KANG ; Seong-Ho KOH ; Jae Seung KIM ; So Young MOON ; Won-Jin MOON ; Young Ho PARK ; YongSoo SHIM ; Dong Won YANG ; Young Chul YOUN ; Young Hee JUNG ; Hanna CHO ; Hojin CHOI ; Jae-Sung LIM ; Kee Hyung PARK ; Seong Hye CHOI
Dementia and Neurocognitive Disorders 2026;25(1):25-41
Background:
and Purpose: To assess the long-term effectiveness, safety, and economic viability of recently approved Alzheimer’s disease (AD) therapies, as well as to evaluate the real-world application of novel diagnostics among AD patients with diverse comorbidities, comprehensive real-world data (RWD) analysis is essential. The Korean JOint RegistrY for ALZheimer’s Treatment and Diagnostics (JOY-ALZ) endeavors to create a registry of RWD derived from clinical practice on new diagnostic methods and therapeutic agents for AD introduced in Korea since 2021.
Methods:
Participants must fulfill all the following: 1) be at least 19 years old; 2) be actively receiving, scheduled to initiate, or undergoing evaluation for any AD disease-modifying treatment; 3) have completed amyloid positron emission tomography or cerebrospinal fluid AD immunoassay (a positive result is not essential for participation); 4) have a clinical classification of cognitively unimpaired, mild cognitive impairment, or probable AD dementia. Data generated during routine care is segmented into a minimum dataset, extended dataset, and research-only dataset requiring extra consent. Assessments encompass clinical, cognitive, functional, neurobehavioral, neuroimaging, and biomarker evaluations, in addition to systematic monitoring of new AD treatments and their safety.Data are collected and monitored at baseline, at semiannual intervals during the initial 2 years, and then annually up to 2034. To date, 46 medical centers will participate in JOY-ALZ.
Conclusions
JOY-ALZ is expected to promote understanding of the long-term clinical outcomes, safety, and cost-effectiveness of recently introduced diagnostics and treatments for AD, thereby supporting the progress of precision medicine in AD care and diagnosis.
7.New Users of Sodium-Glucose Cotransporter 2 Inhibitors Are at Low Risk of Prostate Cancer: A Nationwide Cohort Study
Yun Kyung CHO ; Sehee KIM ; Myung Jin KIM ; Woo Je LEE ; Ye-Jee KIM ; Chang Hee JUNG
Diabetes & Metabolism Journal 2026;50(1):90-100
Background:
Preclinical studies have reported anticancer properties of sodium-glucose cotransporter 2 inhibitors (SGLT2is). We aimed to elucidate the association between the use of SGLT2is and the risk of prostate cancer among male patients with type 2 diabetes mellitus (T2DM).
Methods:
An active-comparator, new-user cohort design using a nationwide database between September 2014 and June 2020 was conducted on 45,601 new SGLT2i users and 205,395 new users of other glucose-lowering medications (oGLMs). In the following 1:1 propensity score matched (PSM) analysis, 35,371 SGLT2i users matched with an equivalent number of oGLM users were assessed. The hazard ratios (HRs) and 95% confidence intervals (CIs) for prostate cancer were calculated.
Results:
Among the cohort, prostate cancer was diagnosed in 210 out of 45,601 SGLT2i users, corresponding to a cumulative incidence of 1.0%, in contrast to 1,880 cases among 205,395 users of oGLMs, with a cumulative incidence of 1.5%. The use of SGLT2is was significantly correlated with a reduced risk of prostate cancer based on a multivariable-adjusted HR of 0.83 (95% CI, 0.71 to 0.98). PSM analysis affirmed 18% reduction in prostate cancer risk associated with SGLT2i use (HR, 0.82; 95% CI, 0.67 to 0.99). Subgroup analyses revealed that body mass index (BMI) significantly influenced the effect of SGLT2i on prostate cancer risk, with a more pronounced reduction in the subgroup with a BMI <25 kg/m2 (P=0.037).
Conclusion
The use of SGLT2is in Korean male patients with T2DM is associated with a lower risk of prostate cancer.
8.Structured Integration of an Artificial Intelligence-Based System for the Optical Diagnosis of Colorectal Polyps
Hae Yeon KANG ; Soonwhan KANG ; Goh Eun CHUNG ; Dong Hoon BAEK ; Hong Sub LEE ; Jinbae PARK ; Sun Young YANG ; Seon Hee LIM ; Ji Min CHOI ; Jung KIM ; Jung Ho BAE
Gut and Liver 2026;20(1):86-96
Background/Aims:
Recent advances in computer-aided diagnosis (CADx) systems have demonstrated expert-level accuracy in the optical diagnosis of colorectal polyps. High-confidence (HC) diagnoses have been defined as those made within 3 seconds without hesitation, and these systems have been shown to improve diagnostic accuracy. We aimed to evaluate the performance of endoscopists with varying levels of experience in diagnosing colorectal polyps with the assistance of a new CADx system applying the 3-second rule and without artificial intelligence assistance.
Methods:
In this multicenter ex vivo study, 35 endoscopists assessed 100 polyps (51 adenomas, 39 hyperplastic polyps, 10 sessile serrated lesions) using narrow-band imaging video clips on an online platform. Assessments consisted of individual endoscopist diagnosis and CADx-assisted diagnosis. HC assignments followed the 3-second rule in both phases. Performance metrics included HC accuracy, HC rate, and adherence to the Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) and Simple Optical Diagnosis Accuracy (SODA) thresholds.
Results:
HC diagnostic accuracy improved from 78.3% (95% confidence interval [CI], 76.6% to 80.0%) to 89.8% (95% CI, 88.6% to 90.9%) with CADx assistance (p<0.001). The proportion of HC predictions increased from 64.2% to 75.4% (p<0.001). Novice endoscopists showed marked improvement with CADx (74.1% vs 88.8%; p<0.001). CADx-assisted diagnoses nearly met SODA and PIVI thresholds under the 3-second rule. Additional analysis demonstrated that CADx assistance significantly improved interobserver agreement and ground truth, particularly for novices (κ=0.37 to κ=0.65; p<0.001).
Conclusions
Integrating CADx with the 3-second rule significantly enhances the performance of endoscopists in the optical diagnosis of colorectal polyps, with the greatest benefit observed among novice endoscopists.
9.Establishing Epidemiological Cutoff Values for Helicobacter pylori Strains in Korea: A Model-Based Analysis of Antibiotic Resistance Patterns
Jin Hee NOH ; Jung Mogg KIM ; Hwoon-Yong JUNG ; Ji Yong AHN ; Sun Mi LEE ; Seong Woo JEON ; Yong Hwan KWON ; Jeong Hoon LEE ; Kee Don CHOI ; Eun Jeong GONG
Gut and Liver 2026;20(1):47-58
Background/Aims:
The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization.
Methods:
The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics.
Results:
The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline.
Conclusions
This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.
10.Korean Large Language Models for Medical Question Answering on Arthritis: Fine-tuning and Comparative Evaluation
Healthcare Informatics Research 2026;32(2):125-133
Objectives:
Large language models (LLMs) are increasingly being used for medical question-answering (QA) tasks. However, most models are trained primarily on English-language data, which limits their effectiveness in non-English clinical contexts. In healthcare settings such as Korea, LLMs adapted to both the local language and the medical domain are needed. This study aimed to evaluate the performance of Korean-native and multilingual LLMs fine-tuned on Korean arthritis-related medical QA data and to examine the impact of language and domain adaptation.
Methods:
A dataset of 5,451 Korean QA pairs related to arthritis was constructed from a public medical corpus (AI Hub). Five LLMs (Mi:dm, EXAONE, Kanana, HyperCLOVAX, and LLaMA) were fine-tuned under identical conditions using Low-Rank Adaptation with 4-bit quantization. Model performance was evaluated on 597 validation samples using BERTScore-F1 and SBERT similarity, along with a qualitative evaluation of clinical correctness, safety, and response completeness.
Results:
EXAONE and HyperCLOVAX showed comparable quantitative performance in semantic accuracy and contextual consistency. Mi:dm achieved lower similarity-based scores than EXAONE and HyperCLOVAX but showed the highest performance in the qualitative evaluation, particularly for clinical correctness. Kanana exhibited moderate performance with limited domain adaptability. LLaMA showed the lowest performance in Korean medical QA, although it achieved the largest relative improvement, indicating challenges in adaptation to Korean clinical contexts.
Conclusions
Domain-specific fine-tuning and Korean-oriented model design improved performance in Korean arthritis medical QA. EXAONE and HyperCLOVAX achieved the highest semantic similarity, whereas Mi:dm demonstrated superior clinical correctness and safety in the qualitative evaluation. General multilingual LLaMA remained limited despite substantial gains, supporting the development of disease-specific Korean medical LLMs.

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