1.Facet Effusion-Incorporating Grading System:A Modified Magnetic Resonance Imaging-Based Classification That Enhances Surgical Prognostication in Lumbar Foraminal Stenosis
Sung Taeck KIM ; Dong-Ho KANG ; Hyoungmin KIM ; Bong-Soon CHANG ; Jae Hun KIM ; Seonpyo JANG ; Jun-Yeop LEE ; Sam Yeol CHANG
Clinics in Orthopedic Surgery 2026;18(1):71-77
Background:
The conventional magnetic resonance imaging (MRI) grading system for foraminal stenosis (FS), known as the Lee classification, was introduced in 2010 and is widely utilized in clinical practice. Previous studies have reported that the conventional grading system for FS lacks prediction ability for surgical treatment. The purpose of this study was to develop a novel MRI grading system for lumbar FS with improved prediction ability for surgical treatment by incorporating facet effusion to indicate segmental instability.
Methods:
We retrospectively reviewed patients diagnosed with lumbar FS between 2011 and 2017 who had a follow-up period of at least 5 years. The FS severity was assessed using a conventional MRI grading system developed by Lee et al. We recorded whether the patient underwent surgical treatment for FS during the follow-up period and the time from the initial diagnosis to surgery. Survival analysis using a Kaplan-Meier curve and log-rank test was performed to verify the impact of FS severity on the surgical treatment. We performed additional survival analysis after modifying the grading system by incorporating the presence of excessive facet joint effusion assessed using axial MRI. We also compared the discrimination ability of the modified and conventional grading systems using Uno’s concordance index (C-index).
Results:
In total, 235 patients with a mean age of 63.7 years were included in this study. During the mean follow-up period of 8.1 years, 63 patients underwent surgical treatment for FS. The conventional grading system revealed no significant difference in survival between the grade 2 and 3 groups (p = 0.104). Conversely, the modified grading system revealed a significant difference in survival between the new grade 2 and 3 groups (p < 0.001). After modification, the discrimination ability, assessed using Uno’s Cindex, significantly improved from 0.69 to 0.73.
Conclusions
The Facet Effusion-Incorporating Grading System, which adds excessive facet joint effusion to the conventional MRI grading framework, demonstrated improved predictive value for surgical treatment and better discriminatory ability compared with the original system.
2.Delayed Retroperitoneal Hematoma Following Intradiscal Electrothermal Therapy: A Case Report of a Rare Complication
Jun-Yong CHA ; Yun-Young PARK ; Jin-Uk KIM ; Jun-Ho LEE ; Seong-Hwan MUN ; Gun AHN ; Il-Tae JANG
The Nerve 2026;12(1):36-40
Intradiscal electrothermal therapy (IDET) is a minimally invasive procedure used to treat discogenic back pain and offers an alternative to surgical intervention in selected patients. Although it is generally considered safe, rare but significant complications can occur and may be difficult to diagnose because their symptoms overlap with those of other spinal conditions. We describe the case of a 69-year-old woman who presented with severe lower back and left buttock pain that was unresponsive to conservative treatment. Magnetic resonance imaging revealed disc bulging with a high-intensity zone at the L4–5 and L5–S1 levels. IDET was performed at the L4–5 level, resulting in initial pain relief. However, the patient returned 7 days later with recurrent pain. Despite undergoing percutaneous epidural neuroplasty at the left L5–S1 level, a medial branch block, and a piriformis muscle block, her symptoms persisted. Further evaluation with spinal computed tomography revealed a retroperitoneal hematoma near the left psoas muscle. Referred pain from the hematoma mimicked discogenic pain, resulting in delayed diagnosis and unnecessary interventions. The patient remained hemodynamically stable and gradually improved with conservative management alone. This case highlights retroperitoneal hematoma as a rare complication of IDET and emphasizes the importance of accurate and timely diagnosis in patients with persistent or worsening symptoms after spinal procedures. Clinicians should consider non-discogenic sources of pain when treatment outcomes deviate from expected patterns.
3.Muscle Loss Driven by Extracellular Signal-Regulated Kinase Suppression via β-Adrenergic Activation in High-Normal Catecholamine Status
Jieun LEE ; Ju Yeon KWAK ; Ho Yeop LEE ; Ji Sun MOON ; Hyo Ju JANG ; Ha Thi NGA ; Thi Linh NGUYEN ; Alfin Mohammad ABDILLAH ; Junglyun KIM ; Sihwan KIM ; Yong Ryoul YANG ; Jeong Eun LEE ; Hyon-Seung YI
Endocrinology and Metabolism 2026;41(2):319-332
Background:
Catecholamines play a crucial role in muscle biogenesis, but their persistent elevation is linked to muscle wasting, which is poorly understood. This study aimed to investigate the association between catecholamine levels and age-related muscle loss.
Methods:
This retrospective study evaluated the plasma levels of two catecholamines, metanephrine and normetanephrine, and the clinical characteristics of 830 patients with adrenal incidentaloma on computed tomography (CT). Cross-sectional CT data at the L3 lumbar vertebrae were used to measure muscle areas. In vitro studies on C2C12 myotubes were conducted to examine β-adrenergic receptor signaling pathways and their role in myogenesis.
Results:
Men had significantly higher mean metanephrine levels of 0.17 nmol/L and normetanephrine levels of 0.63 nmol/L than women (P<0.05). Total abdominal muscle area was negatively correlated with catecholamine levels in both men and women, with the strongest negative correlation between normetanephrine levels and total abdominal muscle area in men (r=–0.31, P<0.001). Similarly, the strongest negative correlation between visceral fat area and metanephrine was observed in men (r=–0.25, P=0.004). Clenbuterol, a β-adrenergic receptor agonist, inhibited myogenesis, including myotube formation by extracellular signal-regulated kinase (ERK) suppression in C2C12 myoblasts. Conversely, β-blockers increased myogenesis via increasing ERK phosphorylation in C2C12 cells. These findings suggest that β-adrenergic modulation influences skeletal muscle differentiation, with ERK phosphorylation.
Conclusion
Catecholamine levels are associated with age, sex, muscle mass, and fat mass. Monitoring catecholamine levels, particularly in older men and in individuals with reduced muscle mass, may help manage age-related muscle loss and lead to individualized treatment strategies.
4.Exosomes from Human Embryonic Stem Cell-Derived Mesenchymal Stem Cells Protect Lung Epithelium and Attenuate Fibrosis
Sangryul CHA ; Jooyeon LEE ; Jimin JANG ; Yeongcheol KIM ; Dahee HAN ; Seok-Ho HONG ; Seung-Jin KIM ; Dae-Hee LEE ; Chung Hyeun MA ; Han Pil LEE ; Se-Ran YANG
International Journal of Stem Cells 2026;19(1):66-82
Idiopathic pulmonary fibrosis (IPF) is characterized by maladaptive epithelial–mesenchymal crosstalk and progressive extracellular matrix accumulation, whereas currently available antifibrotic agents merely decelerate functional decline.This study investigated whether exosomes derived from human mesenchymal stem cells derived from embryonic stem cells (ESC-MSCs) restore epithelial stress responses and attenuate fibrotic remodeling. Human IPF lung transcriptomes were integrated with a bleomycin-induced murine model analyzed by RNA sequencing and protein signaling, together with cigarette smoke extract-induced injury in A549 epithelial cells. ESC-MSCs-derived exosomes exhibited typical morphology and size distribution, enrichment of tetraspanins, and absence of endoplasmic reticulum contamination, consistent with high-purity preparations. Across human IPF and bleomycin-injured lungs, transcriptomic profiling revealed prominent enrichment of extracellular matrix and cytoskeletal gene programs, whereas mitogen-activated protein kinase (MAPK) and Smad families displayed only modest alterations at the mRNA level. In vivo administration of exosomes during the fibrotic remodeling phase, via either intravenous or intratracheal delivery, resulted in improved body weight, reduced lung weight-to-body weight ratios, and decreased collagen deposition and Ashcroft scores. These structural and functional improvements were accompanied by suppression of profibrotic and mesenchymal markers and selective attenuation of activator protein-1 (AP-1) activity. In epithelial injury models, ESC-MSCs-derived exosomes enhanced cell viability, restored redox homeostasis, and constrained stress-induced mesenchymal gene expression and MAPK phosphorylation in both co-treatment and post-treatment settings. Collectively, these data support an epithelial-centered mechanism in which ESC-MSCs-derived exosomes re-establish oxidative balance and selectively restrict AP-1-driven stress signaling, thereby secondarily limiting extracellular matrix accumulation and fibrotic remodeling.
5.Multifactorial Risk Assessment for the Survival of Endodontically Treated Abutments in Removable Partial Dentures: A Retrospective Study
Seo-Yeon LEE ; Jin-Young JANG ; Hye-Jin KIM ; Ran-Ah KIM ; Sun-Ho KIM ; Jeong-Hee KIM
Journal of Korean Dental Science 2026;19(1):23-34
Objective:
This study aimed to evaluate the survival of removable partial dentures (RPDs) abutment teeth that had undergone root canal treatment (RCT) and to identify the factors influencing survival.
Materials and Methods:
Records from the Veterans Health Service Medical Center were reviewed to identify patients who received RPDs between 2014 and 2015 and had root canal-treated abutment teeth. Preoperative variables included patient demographics, tooth location, and periapical radiolucency, while postoperative variables included RPD classification, opposing dentition, crown-root ratio (CRR), root canal filling quality, post placement, and restoration type. Statistical analysis was performed using the Kaplan-Meier method and Cox proportional hazards models.
Results:
A total of 776 root canal-treated abutment teeth from 341 patients using RPDs (mean age, 72.03 years) were included. In the multivariate analysis, tooth-related conditions such as arch type and tooth location, presence of a periapical lesion, and presence of a core were significantly associated with poor prognosis. Kaplan-Meier survival analysis revealed that the 3-, 5-, 7-, and 10-year survival rates for all teeth were 93.5%, 84.4%, 77.1%, and 60.0%, respectively.
Conclusion
Arch type and tooth position, preoperative periapical radiolucency, and type of restoration are significantly associated with prognosis in patients with RPDs in whom the abutment teeth have previously undergone RCT.
6.Clinical Characteristics and Survival Data of Korean Malignant Melanoma in Situ:A Single-Center Experience with 156 Patients (2008∼2021)
Jin Seon BANG ; Jin Ho KIM ; Do Young PARK ; Seok-Jong LEE ; Nam Gyoung HA ; Dae-Lyong HA ; Yong Hyun JANG ; Weon Ju LEE ; Jun Young KIM
Korean Journal of Dermatology 2026;64(1):10-17
Background:
Although patients with malignant melanoma in situ (MIS) have a high survival rate, a risk of recurrence or upstaging remains. Thus, a comprehensive understanding of its prognosis is essential for optimal patient management.
Objective:
To investigate the clinical characteristics and survival outcomes of Korean patients with MIS.
Methods:
We retrospectively analyzed the medical records and photographs of patients with MIS treated at a single tertiary center between 2008 and 2021. Clinical features, including diagnosis, treatment, recurrence, and mortality, were examined.
Results:
A total of 156 patients with MIS were included, with a mean age of 59.3 years. The most common subtype was acral lentiginous melanoma (80.8%). Delayed diagnosis was associated with subungual MIS (SUMis; p <0.05). Among the subtypes other than SUMis, 77.3% met three or more of the ABCD criteria for melanoma.Hutchinson’s sign was observed in 67.3% of cases of SUMis. Ulceration was present in only two cases (1.3%).Recurrence occurred in nine patients (5.8%), with four (2.6%) experiencing relapse after 5 years. Upstaging was observed in two patients (1.3%) due to intralymphatic or regional nodal metastasis occurring at 19 and 10 months post-treatment. The 5-year and 10-year melanoma-specific/overall survival rates were 100.0/96.9% and 100.0/89.0%, respectively.
Conclusion
Although the survival rates of patients with MIS are high, long-term and close follow-up after treatment is essential because of the possibility of late recurrence and rare instances of intralymphatic or regional nodal metastasis. Additionally, the presence of clinical ulceration is highly suggestive of invasive melanoma.
7.Remission of diabetes with glutamic acid decarboxylase antibody positivity that developed after the administration of olanzapine: a case report
Kyuho KIM ; Soo Hyun SEO ; Yun Ji HONG ; Woojae MYUNG ; Bomi KIM ; Chang Ho AHN ; Sung Hee CHOI ; Hak Chul JANG ; Tae Jung OH
Precision and Future Medicine 2026;10(1):51-56
Olanzapine is a second-generation antipsychotic drug associated with the development of type 2 diabetes. However, the development and remission of diabetes with glutamic acid decarboxylase (GAD) antibody (Ab) positivity related to olanzapine treatment have not been reported. Here, we present the case of a 33-year-old man taking olanzapine who was diagnosed with diabetes with GAD Ab positivity complicated by diabetic ketoacidosis (DKA). After discontinuation of the drug and tight glycemic control, his diabetes remitted, and the GAD Ab became negative spontaneously after 18 months. The classification of diabetes is challenging because of overlapping autoimmune and metabolic features. Olanzapine may have contributed to pancreatic β-cell apoptosis, which could potentially trigger autoimmunity and the development of type 1 diabetes-like features (DKA as the initial presentation, a low C-peptide level, and GAD Ab positivity). The rapid amelioration of hyperglycemia and weight reduction may be responsible for the remission of diabetes after the discontinuation of olanzapine.
8.Psychometric Properties of the Mixed State Severity Index for Patients With Mood Disorder
Woojae MYUNG ; Hyeona YU ; Hyo Shin KANG ; Daseul LEE ; Junwoo JANG ; Jakyung LEE ; Joohyun YOON ; Yun Seong PARK ; Hyun A RYOO ; Ye Rim KIM ; Kwang Ho PARK ; Chan Woo LEE ; Yoonjeong JANG ; Kimyoung KIM ; Nara LEE ; Sanghoon HONG ; Hong-Hee WON ; Tae Hyon HA ; Jungkyu PARK
Psychiatry Investigation 2026;23(1):106-117
Objective:
This study aimed to develop a reliable and valid Mixed State Severity Index (MSSI) to assess mood instability in patients with mood disorders and determine cutoff scores.
Methods:
Twenty-one items were selected based on Koukopoulos’ criteria for mixed depressive episode, historically referred to as agitated depression, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision mixed features criteria. The MSSI was administered to 242 patients (major depressive disorder [n=92], bipolar disorder [BD] I [n=78], and BD II [n=72]) and 726 controls.
Results:
The MSSI demonstrated high internal consistency (α=0.78–0.90). Exploratory factor analysis revealed a stable four-factor structure. Based on receiver operating characteristic analysis, optimal cutoff scores were identified to distinguish mood disorder groups from controls, ranging from 19.5 to 27.5 depending on diagnosis.
Conclusion
The MSSI is a reliable and valid instrument for assessing the severity of mixed features in patients with mood disorders. The established cutoff scores enhance its clinical utility, providing robust diagnosis and treatment planning support.
9.Applying National Whole-genome Sequencing Findings for Rare Diseases in Clinical Practice: The Imperative of a Multidisciplinary Approach
Kyung Sun PARK ; Sunghwan SHIN ; Jong-Ho PARK ; Young-Eun KIM ; Won Kyung KWON ; Min-Kyung SO ; Changhee HA ; Ja-Hyun JANG ; Taeheon LEE ; Chang-Seok KI ; Yoonjung KIM ; Kyung-A LEE ; Inho PARK ; Sejoon LEE ; Hong-Hee WON ; ; Jong-Won KIM
Annals of Laboratory Medicine 2026;46(1):94-103
Background:
As nationwide government-led whole-genome sequencing (WGS) projects progress, optimizing the clinical integration of large-scale WGS results is crucial. We explored how the initial analysis from Korea’s First WGS Pilot Study for Rare Diseases was applied in clinical practice, and then we reanalyzed the data comprehensively at Samsung Medical Center (SMC) Seoul, Korea.
Methods:
A prospective cohort study designed to collect WGS data under a Korean national initiative was conducted from August 2020 to December 2021. We focused on patients with rare diseases recruited from 16 university hospitals. The participants included 5,000 individuals (2,200 probands and 2,800 family members). The initial WGS data and diagnostic reference reports (from 682 probands and 484 family members), generated based on the First Korean WGS Pilot Study for Rare Diseases, were subsequently reanalyzed by SMC.
Results:
The initial analysis of the First Korean WGS Pilot Study data revealed a diagnostic rate of 17%. Upon receiving these results, the SMC conducted two rounds of reanalysis, increasing the diagnostic rate from 15% in the first analysis, to 18% in the second, and finally to 24% in the third (P = 1.6 × 10 −5 ). Key factors in improving the genetic diagnosis included increased detection of novel (likely) pathogenic variants (P = 1.0 × 10 −4 ), improved diagnostic rates with larger family recruitment (P = 0.004), and refined clinical information for more precise genotype–phenotype correlation analysis (40%).
Conclusions
Although national WGS projects lay a foundation for rare disease diagnosis, hospital-level reanalysis and multidisciplinary collaborations are crucial for optimizing diagnostic outcomes.
10.Detection of Fusion Genes Using RNA Sequencing in Acute Leukemia
Hyun-Young KIM ; Boram KIM ; Min-Seung PARK ; Jong-Ho PARK ; Hee Young JU ; Keon Hee YOO ; Jun Ho JANG ; Chul Won JUNG ; Hee-Jin KIM
Annals of Laboratory Medicine 2026;46(3):257-269
Background:
Fusion genes are major drivers of acute leukemia. Conventional diagnostics are limited in detecting the diverse fusions included in recently updated acute leukemia classifications. We evaluated the fusion detection performance of RNA sequencing (RNAseq) compared with that of conventional diagnostics in patients with acute leukemia.
Methods:
We retrospectively obtained the data of 101 patients with acute leukemia who underwent conventional diagnostics (i.e., karyotyping, FISH, or multiplex reverse transcription PCR) at diagnosis at Samsung Medical Center, Seoul, Korea, between September 2022 and September 2023. Whole RNA-seq was performed using the Illumina Stranded mRNA Prep kit (Illumina, San Diego, CA, USA). The concordance, sensitivity, and specificity of RNA-seq for fusion gene detection were compared with those of conventional diagnostics.
Results:
RNA-seq helped identify 52 fusion genes in 51 (50.5%) of 101 patients, with detection rates of 40.7%, 70.3%, 37.5%, and 50% in acute myeloid leukemia, B-cell acute lymphoblastic leukemia, T-cell acute lymphoblastic leukemia, and mixed-phenotype acute leukemia, respectively. RNA-seq showed 83.3% sensitivity and 80.8% concordance with conventional diagnostics; it missed eight fusions, likely because of low transcript abundance or enhancer hijacking. RNA-seq also helped clarify three previously unspecified rearrangements and detected 12 fusions (21.4%) in 56 cases that tested negative with conventional diagnostics, including four novel (KMT2A::THAP12 , RUNX1::PRPF19 , MLLT10::UBE2L6, and FUS::ZNF362) and three rare (HNRNPH1::ERG, RUNX1::USP42, and ETV6::NCOA2) fusions.
Conclusions
This was the first study to evaluate the performance of whole RNA-seq in fusion detection in patients with acute leukemia in Korea. Incorporating RNA-seq into diagnostic workflows may facilitate earlier and more precise therapeutic decisions and improve prognostic assessment in patients with acute leukemia.

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