1.Simulating the effects of reducing transfer latency from the intensive care unit on intensive care unit bed utilization in a Korean Tertiary Hospital
Jaeyoung CHOI ; Song-Hee KIM ; Ryoung-Eun KO ; Gee Young SUH ; Jeong Hoon YANG ; Chi-Min PARK ; Joongbum CHO ; Chi Ryang CHUNG
Acute and Critical Care 2025;40(1):18-28
Background:
Latency in transferring patients from intensive care units (ICUs) to general wards impedes the optimal allocation of ICU resources, underscoring the urgency of initiatives to reduce it. This study evaluates the extent of ICU transfer latency and assesses the potential benefits of minimizing it.
Methods:
Transfer latency was measured as the time between the first transfer request and the actual ICU discharge at a single-center tertiary hospital in 2021. Computer-based simulations and cost analyses were performed to examine how reducing transfer latency could affect average hourly ICU bed occupancy, the proportion of time ICU occupancy exceeds 80%, and hospital costs. The first analysis evaluated all ICU admissions, and the second analysis targeted a subset of ICU admissions with longer transfer latency, those requiring infectious precautions.
Results:
A total of 7,623 ICU admissions were analyzed, and the median transfer latency was 5.7 hours. Eliminating transfer latency for all ICU admissions would have resulted in a 32.8% point decrease in the proportion of time ICU occupancy exceeded 80%, and a potential annual savings of $6.18 million. Eliminating transfer latency for patients under infectious precautions would have decreased the time ICU occupancy exceeded 80% by 13.5% points, and reduced annual costs by a potential $1.26 million.
Conclusions
Transfer latency from ICUs to general wards might contribute to high ICU occupancy. Efforts to minimize latency for all admissions, or even for a subset of admissions with particularly long transfer latency, could enable more efficient use of ICU resources.
3.Chromosomal Rearrangements in 1,787 Cases of Acute Leukemia in Korea over 15 Years
DongGeun SON ; Ho Cheol JANG ; Young Eun LEE ; Yong Jun CHOI ; Joo Heon PARK ; Ha Jin LIM ; Hyun-Jung CHOI ; Hee Jo BAEK ; Hoon KOOK ; Mihee KIM ; Ga-Young SONG ; Seo-Yeon AHN ; Sung-Hoon JUNG ; Deok-Hwan YANG ; Je-Jung LEE ; Hyeonug-Joon KIM ; Jae-Sook AHN ; Myung-Geun SHIN
Annals of Laboratory Medicine 2025;45(4):391-398
Background:
Chromosomal alterations serve as diagnostic and prognostic markers in acute leukemia. Given the evolving landscape of chromosomal abnormalities in acute leukemia, we previously studied these over two periods. In this study, we investigated the frequency of these abnormalities and clinical trends in acute leukemia in Korea across three time periods.
Methods:
We retrospectively analyzed data from 1,787 patients with acute leukemia (319 children and 1,468 adults) diagnosed between 2006 and 2020. Conventional cytogenetics, FISH, and multiplex quantitative PCR were used for analysis. The patient groups were divided according to the following three study periods: 2006–2009 (I), 2010–2015 (II), and 2016–2020 (III).
Results:
Chromosomal aberrations were detected in 92% of patients. The PML::RARA translocation was the most frequent. Over the 15-yr period, chromosomal aberrations showed minimal changes, with specific fusion transcripts being common among patients.ALL was more prevalent in children than in adults and correlated significantly with the ETV6::RUNX1 and RUNX1::RUNX1T1 aberrations. The incidence of ALL increased during the three periods, with PML::RARA remaining common.
Conclusions
The frequency of chromosomal abnormalities in acute leukemia has changed subtly over time. Notably, the age of onset of adult AML has continuously increased. Our results may help in establishing diagnoses and clinical treatment strategies and developing various molecular diagnostic platforms.
4.Clinical Pharmacogenetic Testing and Application:2024 Updated Guidelines by the Korean Society for Laboratory Medicine
John Hoon RIM ; Young-gon KIM ; Sollip KIM ; Rihwa CHOI ; Jee-Soo LEE ; Seungman PARK ; Woochang LEE ; Eun Young SONG ; Soo-Youn LEE ; Sail CHUN ;
Annals of Laboratory Medicine 2025;45(2):121-132
In the era of precision medicine, pharmacogenetics has substantial potential for addressing inter-individual variability in drug responses. Although pharmacogenetics has been a research focus for many years, resulting in the establishment of several formal guidelines, its clinical implementation remains limited to several gene–drug combinations in most countries, including Korea. The main causes of delayed implementation are technical challenges in genotyping and knowledge gaps among healthcare providers; therefore, clinical laboratories play a critical role in the timely implementation of pharmacogenetics. This paper presents an update of the Clinical Pharmacogenetic Testing and Application guidelines issued by the Korean Society for Laboratory Medicine and aims to provide the necessary information for clinical laboratories planning to implement or expand their pharmacogenetic testing. Current knowledge regarding nomenclature, gene–drug relationships, genotyping technologies, testing strategies, methods for clinically relevant information delivery, QC, and reimbursements has been curated and described in this guideline.
5.A Novel Fibrinogen Assay Using Recombinant Batroxobin and Carboxymethyl Chitosan:Carboxymethyl Chitosan Stimulates the Enzymatic Activity of Recombinant Batroxobin
Jung-Ah KIM ; Eunhye KO ; Yongje WOO ; Young-Doug SOHN ; Jong-Tak KIM ; Jaewoo SONG ; Rojin PARK
Annals of Laboratory Medicine 2025;45(5):484-492
Background:
The Clauss assay is widely used to quantify blood fibrinogen levels in clinical laboratories. However, by relying on thrombin as the main reagent, the Clauss assay is susceptible to interference from thrombin inhibitors, such as heparin or direct thrombin inhibitors. Here, we developed an innovative fibrinogen assay utilizing both recombinant batroxobin (rBat) and carboxymethyl chitosan (CMCS).
Methods:
Various biopolymers were tested to identify a suitable candidate that could enhance rBat-induced fibrin clot formation. Chromogenic substrate hydrolysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that CMCS potentiated rBat activity. Consequently, we formulated a novel fibrinogen assay reagent, ANYFIB.C, comprising rBat and CMCS. We compared ANYFIB.C fibrinogen with an established reagent (HemosIL fibrinogen-C) with 96 clinical samples using an ACL-TOP 700 coagulation analyzer. We also evaluated the interfering effects of thrombin inhibitors on fibrinogen measurements.
Results:
CMCS significantly enhanced the enzymatic activity of rBat and dose-dependently reduced plasma clotting times. ANYFIB.C fibrinogen levels were comparable with those of HemosIL fibrinogen-C, with the 95% confidence intervals of the Passing–Bablok regres-sion intercept and slope being −7.4797 to 6.0185 and 0.9581 to 1.0116, respectively. Nosignificant interference was observed with heparin concentrations up to 10 U/mL or dabigatran concentrations up to 600 µg/L in the ANYFIB.C fibrinogen assays. In contrast, the HemosIL fibrinogen-C reagent demonstrated inhibitory interference at dabigatran concentrations as low as 150 µg/L.
Conclusions
Our results suggest that ANYFIB.C (a mixture of CMCS and rBat) can be used to measure blood fibrinogen levels effectively and protect from thrombin inhibitor interference.
6.Progressive tooth pattern changes in Cilk1-deficient mice depending on Hedgehog signaling.
Minjae KYEONG ; Ju-Kyung JEONG ; Dinuka ADASOORIYA ; Shiqi KAN ; Jiwoo KIM ; Jieun SONG ; Sihyeon PARK ; Suyeon JE ; Seok Jun MOON ; Young-Bum PARK ; Hyuk Wan KO ; Eui-Sic CHO ; Sung-Won CHO
International Journal of Oral Science 2025;17(1):71-71
Primary cilia function as critical sensory organelles that mediate multiple signaling pathways, including the Hedgehog (Hh) pathway, which is essential for organ patterning and morphogenesis. Disruptions in Hh signaling have been implicated in supernumerary tooth formation and molar fusion in mutant mice. Cilk1, a highly conserved serine/threonine-protein kinase localized within primary cilia, plays a critical role in ciliary transport. Loss of Cilk1 results in severe ciliopathy phenotypes, including polydactyly, edema, and cleft palate. However, the role of Cilk1 in tooth development remains unexplored. In this study, we investigated the role of Cilk1 in tooth development. Cilk1 was found to be expressed in both the epithelial and mesenchymal compartments of developing molars. Cilk1 deficiency resulted in altered ciliary dynamics, characterized by reduced frequency and increased length, accompanied by downregulation of Hh target genes, such as Ptch1 and Sostdc1, leading to the formation of diastemal supernumerary teeth. Furthermore, in Cilk1-/-;PCS1-MRCS1△/△ mice, which exhibit a compounded suppression of Hh signaling, we uncovered a novel phenomenon: diastemal supernumerary teeth can be larger than first molars. Based on these findings, we propose a progressive model linking Hh signaling levels to sequential changes in tooth patterning: initially inducing diastemal supernumerary teeth, then enlarging them, and ultimately leading to molar fusion. This study reveals a previously unrecognized role of Cilk1 in controlling tooth morphology via Hh signaling and highlights how Hh signaling levels shape tooth patterning in a gradient-dependent manner.
Animals
;
Hedgehog Proteins/physiology*
;
Mice
;
Signal Transduction/physiology*
;
Tooth, Supernumerary
;
Molar
;
Cilia/physiology*
;
Odontogenesis/physiology*
;
Patched-1 Receptor
;
Protein Serine-Threonine Kinases/physiology*
;
Mice, Knockout
;
Adaptor Proteins, Signal Transducing
7.Clinical Exome-Based Redefinition and Reclassification of Retinitis Pigmentosa
Hyo Song PARK ; Kyung KIM ; Dongwook LEE ; Jong-Young LEE ; Jeong Nam CHOI ; Jin Ha KIM ; Jung Woo HAN ; Tae Kwann PARK
Journal of Korean Medical Science 2025;40(16):e54-
Background:
Because of the low prevalence of inherited retinal diseases, reports on the distribution of retinitis pigmentosa (RP)-related genes in Korean patients are scarce. The aim of this study was to determine the mutation spectrum and allele frequency and observe the final diagnoses in a Korean cohort clinically diagnosed with RP.
Methods:
We used whole-exome sequencing (WES) to analyze a Korean cohort of 100 unrelated patients clinically diagnosed with RP. The possible pathogenicity of each variant was assessed based on the guidelines of the American College of Medical Genetics and Genomics and Association for Molecular Pathology, in-silico prediction tools, known clinical phenotypes, and inheritance patterns.
Results:
Definite causative genes were detected in 60/100 patients (60.0%). Of these 60 cases, USH2A was the most common causative gene (14/60, 23.3%), followed by EYS (13/60, 21.7%) and RP1 (6/60, 10.0%). The clinical diagnosis was redefined in 9 of the 60 probands (15.0%) with causative genes after WES. Five of the 60 patients (8.3%) carried a causative variant in CHM, and the clinical diagnosis was redefined as choroideremia. Leber congenital amaurosis was diagnosed in 2/60 probands (3.3%), and RDH12 and RPGRIP1 were the causative genes in each patient. One patient (1/60, 1.7%) was diagnosed with Bietti’s crystalline dystrophy, with CYP4V2 identified as the causative gene. In another patient (1/60, 1.7%), ABCA4 variants were detected with clinical findings suggestive of cone-rod dystrophy.
Conclusion
This study reports the mutational spectrum of a cohort of Korean patients with a clinical diagnosis of RP who were referred for genetic testing. This study adds valuable data regarding the frequency of genes as well as their relation to the age of symptom onset and relation to other inherited retinal degenerations.
8.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.
9.Clinical Exome-Based Redefinition and Reclassification of Retinitis Pigmentosa
Hyo Song PARK ; Kyung KIM ; Dongwook LEE ; Jong-Young LEE ; Jeong Nam CHOI ; Jin Ha KIM ; Jung Woo HAN ; Tae Kwann PARK
Journal of Korean Medical Science 2025;40(16):e54-
Background:
Because of the low prevalence of inherited retinal diseases, reports on the distribution of retinitis pigmentosa (RP)-related genes in Korean patients are scarce. The aim of this study was to determine the mutation spectrum and allele frequency and observe the final diagnoses in a Korean cohort clinically diagnosed with RP.
Methods:
We used whole-exome sequencing (WES) to analyze a Korean cohort of 100 unrelated patients clinically diagnosed with RP. The possible pathogenicity of each variant was assessed based on the guidelines of the American College of Medical Genetics and Genomics and Association for Molecular Pathology, in-silico prediction tools, known clinical phenotypes, and inheritance patterns.
Results:
Definite causative genes were detected in 60/100 patients (60.0%). Of these 60 cases, USH2A was the most common causative gene (14/60, 23.3%), followed by EYS (13/60, 21.7%) and RP1 (6/60, 10.0%). The clinical diagnosis was redefined in 9 of the 60 probands (15.0%) with causative genes after WES. Five of the 60 patients (8.3%) carried a causative variant in CHM, and the clinical diagnosis was redefined as choroideremia. Leber congenital amaurosis was diagnosed in 2/60 probands (3.3%), and RDH12 and RPGRIP1 were the causative genes in each patient. One patient (1/60, 1.7%) was diagnosed with Bietti’s crystalline dystrophy, with CYP4V2 identified as the causative gene. In another patient (1/60, 1.7%), ABCA4 variants were detected with clinical findings suggestive of cone-rod dystrophy.
Conclusion
This study reports the mutational spectrum of a cohort of Korean patients with a clinical diagnosis of RP who were referred for genetic testing. This study adds valuable data regarding the frequency of genes as well as their relation to the age of symptom onset and relation to other inherited retinal degenerations.
10.Consensus Statements on Tinnitus Assessment and Treatment Outcome Evaluation: A Delphi Study by the Korean Tinnitus Study Group
Oak-Sung CHOO ; Jung Mee PARK ; Euyhyun PARK ; Jiwon CHANG ; Min Young LEE ; Ho Yun LEE ; In Seok MOON ; Jae-Jun SONG ; Kyu-Yup LEE ; Jae-Jin SONG ; Eui-Cheol NAM ; Shi Nae PARK ; Hyun Joon SHIM ; Yoon Chan RAH ; Jae-Hyun SEO
Journal of Korean Medical Science 2025;40(7):e93-
Background:
Tinnitus is a multifactorial condition with no universally accepted assessment guidelines. The Korean Tinnitus Study Group previously established consensus statements on the definition, classification, and diagnostic tests for tinnitus. As a continuation of this effort, this study aims to establish expert consensus on tinnitus assessment and treatment outcome evaluation, specifically tailored to the Korean clinical context.
Methods:
A modified Delphi method involving 26 otology experts from across Korea was used. A two-round Delphi survey was conducted to evaluate statements related to tinnitus assessment before and after treatment. Statements were rated on a scale of 1 to 9 for the level of agreement. Consensus was defined as ≥ 70% agreement (score of 7–9) and ≤ 15% disagreement (score of 1–3). Statistical measures such as content validity ratio and Kendall’s coefficient of concordance (W) were calculated to assess agreement levels.
Results:
Of the 46 assessment-related statements, 17 (37%) reached consensus, though overall pre-treatment assessments showed weak agreement (Kendall’s W = 0.319). Key areas of agreement included the use of the visual analogue scale, numeric rating scale, and validated questionnaires for pre-treatment evaluation. Five statements, such as the use of computed tomography, magnetic resonance imaging, and angiography for diagnosing pulsatile tinnitus, achieved over 90% agreement. For treatment outcome measurements, 8 of 12 statements (67%) reached a consensus, with moderate agreement (Kendall’s W = 0.513). Validated questionnaires and psychoacoustic tests were recommended for evaluating treatment effects within 12 weeks. While standardized imaging for pulsatile tinnitus and additional clinical tests were strongly recommended, full consensus was not achieved across all imaging modalities.
Conclusion
This study provides actionable recommendations for tinnitus assessment and treatment evaluation, emphasizing the use of standardized tools and individualized approaches based on patient needs. These findings offer a practical framework to enhance consistency and effectiveness in tinnitus management within Korean clinical settings.

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