1.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.
2.Twig-Like Middle Cerebral Artery : Acquired Lesion Rather than Congenital Anomaly
Yung Ki PARK ; Byul-Hee YOON ; Eui-Hyun HWANG ; Jae Hoon KIM ; Hee In KANG ; Yu Deok WON ; Jin Whan CHEONG
Journal of Korean Neurosurgical Society 2026;69(1):51-60
Objective:
: A twig-like middle cerebral artery (T-MCA) is a rare condition characterized by steno-occlusion of the M1 segment of the middle cerebral artery (MCA) with nearby collateral arterial networks. Despite unclear pathophysiology, it is often classified as a congenital anomaly caused by failure of fusion of the plexiform MCA arterial plexus. We aimed to improve understanding of the pathophysiology of T-MCAs by analyzing incidental T-MCA findings and their natural history.
Methods:
: A retrospective chart review was performed between January 2011 and December 2023 at three medical centers treating both ischemic and hemorrhagic strokes. Patients with suspected MCA lesions were selected through radiology reports from computed tomography, magnetic resonance angiography, and digital subtraction imaging.
Results:
: We identified 51 T-MCA cases from a radiology report search spanning 13 years across three medical centers. The study included 9875 patients with ischemic stroke and 2097 with hemorrhagic stroke. Of the 51 T-MCA cases, incidental findings accounted for 25 (49.0%), ischemic stroke for 18 (35.3%), and hemorrhagic strokes accounted for eight cases (15.7%). T-MCA related ischemic and hemorrhagic strokes accounted for 0.18–0.38% of all strokes. The RNF213.R4810K mutation was identified in seven of 15 patients (46.7%) tested. We found three cases of a de-novo T-MCA that progressed from a normal MCA architecture.
Conclusion
: T-MCAs may represent an acquired secondary anomaly rather than a congenital lesion, followed by steno-occlusion of the focal MCA with new arterial network formation. Both Moyamoya angiopathy and chronic atherosclerosis likely contributed to disease progression. Formation of a microaneurysm, dilatation of the lenticulostriate artery, and hemodynamic stress can lead to stroke.
3.Feasibility and Preliminary Efficacy of Digital Cognitive Training in Parkinson’s Disease With Mild Cognitive Impairment: A Pilot Study
Dongje LEE ; Hang-Rai KIM ; Yu Jeong PARK ; Yisuh AHN ; Daeho LEE ; Jungyeun LEE ; Su Jin CHUNG ; Seung Yeon KIM ; Yeji HWANG ; Ji Young YUN ; Jin Whan CHO ; Kyum-Yil KWON ; Seong-Beom KOH ; Sung Hoon KANG
Journal of Movement Disorders 2026;19(1):76-80
Objective:
Cognitive impairment is common in patients with Parkinson’s disease (PD), and few pharmacological options are available for treating this condition. We evaluated the effects of a digital cognitive training program (SUPERBRAIN), which was previously shown to be effective in populations at risk of Alzheimer’s disease, on cognitive function in individuals with PD.
Methods:
Twenty-three individuals with PD and mild cognitive impairment (PD-MCI) from four clinics were randomized to the intervention (n=16) or control (n=7) groups. The intervention group completed a 12-week, home-based, tablet-based cognitive training program (25–30 min/day, 7 days/week). Cognitive outcomes were assessed using the Seoul Neuropsychological Screening Battery pre- and post-intervention.
Results:
The adherence rate was 79.36%. The intervention group showed significant improvements in the Seoul Verbal Learning Test (SVLT) delayed recall and the Controlled Oral Word Association Test, while no changes were observed in the control group. Analysis of covariance confirmed greater SVLT improvement in the intervention group (F statistic=7.15, p=0.015, partial η2=0.28).
Conclusion
SUPERBRAIN is feasible and can improve cognitive function in individuals with PD-MCI.
4.Molecular determinants of outcome to gemcitabine, cisplatin, and nab-paclitaxel in patients with advanced biliary tract cancer
Daeseong KIM ; Nam Suk SIM ; Seonjeong WOO ; Min Hwan KIM ; Choong-kun LEE ; Seung Soo HONG ; Sung Hyun KIM ; Ho Kyoung HWANG ; Chang Moo KANG ; Woo Jung LEE ; Jung Hyun JO ; Taek CHUNG ; Sohyun HWANG ; Beodeul KANG ; Jung Sun KIM ; Chang-Il KWON ; Sangwoo KIM ; Hong Jae CHON ; Chang Gon KIM ; Young Nyun PARK ; Hye Jin CHOI
Clinical and Molecular Hepatology 2026;32(2):721-736
Background/Aims:
Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC.
Methods:
Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy.
Results:
With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC.
Conclusions
Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.
5.Network meta-analysis and validation study of expanded liver transplantation criteria for hepatocellular carcinoma: Significant role of alpha-fetoprotein
Dongman YU ; Yeongseok HWANG ; Jin-Sung JU ; Subin HEO ; Seon-Ok KIM ; Sang Hyun CHOI ; Gi-Won SONG ; Jihyun AN ; Ju Hyun SHIM
Clinical and Molecular Hepatology 2026;32(2):751-771
Background/Aims:
Various expanded criteria (EC) for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) have been proposed to avoid the narrow nature of the Milan criteria (MC). To investigate which EC predicts more favorable outcomes in terms of overall survival (OS) and recurrence-free survival (RFS), we conducted a network meta-analysis (NMA).
Methods:
A database search was conducted on PubMed, Embase, and the Cochrane Library, to identify studies comparing OS and RFS between patients within the MC and those exceeding the MC but within the EC. Hazard ratios (HRs) were pooled using a random-effects NMA and validated in an in-house cohort of 1,008 LT recipients.
Results:
Among 22,466 articles identified, 35 studies with 45 pairwise comparisons were included in the NMA along with 8 different EC. The University of California San Francisco (HR, 1.43; 95% CI, 1.19–1.71), Up-to-Seven (HR, 1.50; 95% CI, 1.15–1.97), and Hangzhou criteria (HR, 1.69; 95% CI, 1.11–2.57) showed inferior OS to the MC. The MC ranked highest for both OS and RFS, followed by Metroticket 2.0 for OS and the Asan criteria for RFS. In the validation cohort, both Metroticket 2.0 and AFP model yielded more favorable HCC-specific mortality than other EC.
Conclusions
Several EC, of which those of Metroticket 2.0 were the best, yielded comparable outcomes to the MC. AFP-based EC such as Metroticket 2.0 and AFP model appeared to be useful in both the NMA and the validation cohort, suggesting a potential role in identifying selected low-risk patients beyond the MC.
6.Diagnostic and prognostic performance of PAK1 methylation in patients with hepatocellular carcinoma undergoing liver transplantation
Shin HWANG ; Hyo Jung KO ; Eunyoung TAK ; Kyoung-Jin LEE ; Yun-Kyu LEE
Clinical Transplantation and Research 2026;40(1):104-115
Background:
DNA methylation is under investigation as an early diagnostic biomarker for cancers such as hepatocellular carcinoma (HCC). p21-activated protein kinase 1 (PAK1) demonstrates a high methylation tendency in HCC. We assessed the diagnostic and prognostic performance of PAK1 methylation in liver transplantation (LT) recipients with and without HCC.
Methods:
To assess PAK1 methylation, stored pretransplant blood samples from LT recipients were analyzed by droplet digital polymerase chain reaction.
Results:
This study included 274 patients with HCC and 100 control patients without the disease. Ten-year survival rates in the HCC and control groups were 60.5% and 80.6%, respectively (P=0.001). The 10-year HCC recurrence rate was 39.0%. Ten-year survival rates in the HCC recurrence and nonrecurrence groups were 13.3% and 91.2%, respectively (P<0.001); median PAK1 methylation levels in the control and HCC groups were 50.0 and 108.0 copies (P=0.102). The area under the receiver operating characteristic curve was 0.599, and the Youden J index was 0.199, indicating 57.9% sensitivity and 62.0% specificity at a cutoff of 78 copies. With a cutoff of 5 copies, sensitivity was 94.1% and specificity was 14.0%. The positive likelihood ratio was 1.09 and the negative likelihood ratio was 0.42, indicating diagnostic accuracy below α-fetoprotein and protein induced by vitamin K absence or antagonist-II. PAK1 cutoffs of 5 and 10 copies did not affect HCC recurrence, but a cutoff of 2 copies appeared associated with lower recurrence.
Conclusions
These data suggest that PAK1 methylation is not a clinically useful biomarker for HCC in LT recipients. New DNA methylation biomarkers are required for early diagnosis.
7.Acute Heart Failure Across the Ejection Fraction Spectrum: Phenotypes, Management, and Outcomes From Nationwide KorHF III Registry
Huijin LEE ; Eung Ju KIM ; Seong Woo HAN ; Seong-Mi PARK ; Hyung-Seop KIM ; Myung-Chan CHO ; Hyo-Suk AHN ; Mi-Seung SHIN ; Seok-Jae HWANG ; Jin-Ok JEONG ; Dong Heon YANG ; Junho HYUN ; Jin Oh CHOI ; Hae-Young LEE ; Byung-Su YOO ; Seok-Min KANG ; Dong-Ju CHOI ; Hyun-Jai CHO ;
International Journal of Heart Failure 2026;8(1):43-55
Background and Objectives:
Clinical characteristics and outcomes in acute heart failure (AHF) vary by phenotype. We assessed phenotype-specific features, treatment patterns, and outcomes in a nationwide Korean cohort.
Methods:
The Korean Heart Failure III registry prospectively enrolled 7,351 AHF admissions at 47 hospitals. Among 6,777 patients with available left ventricular ejection fraction (EF), phenotypes were defined as heart failure with reduced EF (HFrEF, ≤40%), mildly reduced EF (HFmrEF,41–49%), or preserved EF (HFpEF, ≥50%). The primary endpoint was a 12-month composite of all-cause death or heart transplantation, evaluated from index admission and, among hospital survivors, from discharge. We used inverse probability weighting (multinomial generalized boosted models with stabilized, trimmed weights) and weighted Cox proportional-hazards models to estimate hazard ratios (HRs).
Results:
Phenotype distribution was 58.9% HFrEF, 13.6% HFmrEF, and 27.5% HFpEF. Crude 12-month composite rates from index admission were 13.4% (HFrEF), 12.7% (HFmrEF), and 16.8% (HFpEF). After weighting, from index admission, HFmrEF (HR, 0.892; 95% confidence interval [CI], 0.731–1.088) and HFpEF (HR, 1.101; 95% CI, 0.939–1.291) did not differ from HFrEF; from discharge, HFpEF had modestly higher risk (HR, 1.207; 95% CI, 1.008–1.445) whereas HFmrEF did not (HR, 1.039; 95% CI, 0.844–1.279). Hyponatremia and chronic kidney disease were consistent adverse markers, while angiotensin-converting enzyme inhibitor/ angiotensin II receptor blocker use at discharge was protective.
Conclusions
Across the EF spectrum, phenotypes showed distinct profiles and risk. Postdischarge risk was modestly higher in HFpEF, supporting phenotype-tailored care and systematic discharge optimization in Korean patients with AHF.
8.Biomimetic Architectural Cover Accelerates `Osseointegration of Titanium Implants
Su-Jin KIM ; Eun Chae KIM ; Weon-Young CHOI ; Seung-Jae LEE ; Je-Hwang RYU
Journal of Bone Metabolism 2026;33(1):30-39
Background:
Although various surface modifications enhance titanium (Ti) implant osseointegration, achieving rapid bone formation comparable to native healing remains challenging. Current strategies primarily focus on micro-scale topography, often overlooking the critical role of macroscopic three-dimensional (3D) architecture in osteoconduction.
Methods:
We hypothesized that mimicking native bone’s porous architecture is key to accelerating osseointegration. First, we verified the impact of structural continuity by comparing standard Ti implants with decellularized bone grafts in a mouse calvaria defect model. Subsequently, we developed a biomimetic polycaprolactone (PCL)-based 3D architectural cover (Cover-type) and evaluated its osseointegration efficacy in a rat femur model against conventional Ti implants.
Results:
The mouse study confirmed that decellularized bone integrated significantly faster than Ti, highlighting the necessity of 3D continuity. In the rat model, micro-computed tomography analysis indicated a clear trend of increased bone formation in the Cover-type group, though statistical significance was limited by sample size. However, histological analysis confirmed a statistically significant enhancement in bone-to-implant contact compared to controls (P<0.05). The PCL structure served as a scaffold for cell migration, effectively bridging the implant-bone gap.
Conclusions
These findings suggest that providing a bone-like 3D environment via a PCL cover may enhance histological osseointegration, rather than relying solely on surface chemistry.
9.Nationwide Trends in Coronary Artery Bypass Grafting in the Republic of Korea, 2005–2022: A Comparison with International Data
Min Ho JU ; Jun Ho LEE ; Yun Jin KIM ; Ho Jin KIM ; Ho Young HWANG ; Sang Yoon YEOM ; Hee Jung KIM ; Young-Nam YOUN ; Wook Sung KIM ; Man-Jong BAEK ; Hyun Keun CHEE ;
Journal of Chest Surgery 2026;59(1):7-16
Coronary artery bypass grafting (CABG) remains a key revascularization strategy for ischemic heart disease; however, nationwide trends in the Republic of Korea have not been thoroughly investigated. Using data from the Korean National Health Insurance Service, we analyzed adult patients who underwent isolated CABG between 2005 and 2022. We evaluated surgical volume, patient demographics, procedural strategies (off-pump vs. onpump), and outcomes. International comparisons were conducted using national cardiac surgery registry data. A total of 51,923 CABG cases were identified. Annual surgical volume declined until 2013 but gradually increased thereafter, reaching 3,717 cases in 2022. Despite this recovery, Korea’s per capita CABG rate remains among the lowest worldwide.In contrast, more than 60% of procedures were performed off-pump—the highest rate worldwide. Over time, the average patient age and prevalence of diabetes increased, whereas in-hospital mortality showed a modest decline. Compared with other countries, the Republic of Korea demonstrated a uniquely low procedural volume and a strong preference for off-pump CABG. This nationwide analysis highlights Korea’s distinctive CABG practice patterns and provides valuable insights for optimizing future clinical and policy decisions in cardiac surgical care.
10.National Trends in the Prevalence of Suicide Attempts Among Adolescents by Self-Perceived Weight, 2005–2023: A Nationwide Representative Study in South Korea
Jinyoung JEONG ; Hyunjee KIM ; Hyesu JO ; Hyeon Jin KIM ; Jaeyu PARK ; Jaehyeong CHO ; Jiyoung HWANG ; Seoyoung PARK ; Damiano PIZZOL ; Lee SMITH ; Sang Youl RHEE ; Selin WOO ; Dong Keon YON
Psychiatry Investigation 2026;23(1):48-62
Objective:
Suicide is a leading cause of death among adolescents, and despite the need to distinguish between suicidal consideration and suicide attempts, research focused on suicide attempts remains insufficient. Therefore, this study aims to investigate the influence of self-perceived weight on suicide attempts.
Methods:
This study utilized data from the Korea Youth Risk Behavior Web-based Survey for its analysis from 2005 to 2023, including a total of 1,156,728 participants. This study utilized various analytical methods to examine the influence of self-perceived weight on suicide attempts. We estimated weighted prevalence and used linear regression to assess temporal trend β coefficients and their differences (βdiff) with 95% confidence intervals (CIs), and survey-weighted logistic regression to estimate weighted odds ratios (wORs) and 95% CIs for the association between self-perceived weight and suicide attempts.
Results:
A comparison of suicide attempts based on self-perceived weight suggested that individuals who perceived themselves as overweight (weighted prevalence, 3.97% [95% CI, 3.89 to 4.04]) had the highest rate of suicide attempts, followed by those who perceived themselves as underweight (3.36% [95% CI, 3.28 to 3.44]), while those who perceived themselves as having a normal weight (3.20% [95% CI, 3.14 to 3.27]) had the lowest rate. Additionally, females (underweight: 4.47% [95% CI, 4.32 to 4.62]; normal weight: 3.91% [95% CI, 3.81 to 4.01]; overweight: 5.23% [5.11 to 5.35]) experienced more suicide attempts than males (underweight: 2.73% [95% CI, 2.65 to 2.82]; normal weight: 2.43% [95% CI, 2.35 to 2.51]; overweight: 2.60% [95% CI, 2.52 to 2.69]).
Conclusion
Findings from the present study suggest that self-perceived weight was associated with suicide attempts and interaction analyses indicated a potential sex-based difference in the impact of body image distortion. Therefore, this study suggests the introduction of programs and campaigns aimed at correcting distorted self-perceived weight.

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