Background: TP53 mutations are associated with poor prognosis in myelodysplastic neoplasm (MDS) and AML. The updated 5th WHO classification and International Consensus Classification (ICC) categorize TP53-mutated MDS and AML as unique entities. We conducted a multicenter study in Korea to investigate the characteristics of TP53-mutated MDS and AML, focusing on diagnostic aspects based on updated classifications. Methods: This study included patients aged ≥ 18 yrs who were diagnosed as having MDS(N = 1,244) or AML (N = 2,115) at six institutions. The results of bone marrow examination, cytogenetic studies, and targeted next-generation sequencing, including TP53, were collected and analyzed. Results: TP53 mutations were detected in 9.3% and 9.2% of patients with MDS and AML, respectively. Missense mutation was the most common, with hotspot codons R248/ R273/G245/Y220/R175/C238 accounting for 25.4% of TP53 mutations. Ten percent of patients had multiple TP53 mutations, and 78.4% had a complex karyotype. The median variant allele frequency (VAF) of TP53 mutations was 41.5%, with a notable difference according to the presence of a complex karyotype. According to the 5th WHO classification and ICC, the multi-hit TP53 mutation criteria were met in 58.6% and 75% of MDS patients, respectively, and the primary determinants were a TP53 VAF > 50% for the 5th WHO classification and the presence of a complex karyotype for the ICC. Conclusions Collectively, we elucidated the molecular genetic characteristics of patients with TP53-mutated MDS and AML, highlighting key factors in applying TP53 mutation-related criteria in updated classifications, which will aid in establishing diagnostic strategies.

Background: Pig red blood cells (RBCs) are rapidly eliminated when transfused into nonhuman primates (NHPs) because of immune reactions involving antibody binding and complement activation. We assessed the relationship between post-transfusion hemolysis and complement activation. Methods: RBCs for transfusion were prepared from wild-type (WT) and genetically modified pigs and NHPs. After the withdrawal of 25% of the blood volume, NHPs received transfusions of WT (N = 4), triple knockout (TKO, N = 8), and TKO pig RBCs expressing human CD55 and CD39 (TKO/hCD55.hCD39, N = 4). Additional groups received repeated xenotransfusions (ReXTf, N = 3), NHP RBC transfusions (N = 3), or a saline infusion (N = 4).Blood samples were collected at multiple time points to measure Hb and complement fragment (C3a, C4a, and factor Bb) levels and agglutination titers. Results: Hb levels were restored by transfusions but not by saline infusion. The degree of complement activation varied with the type of transfused RBCs, with significant increases in C3a and factor Bb levels immediately after xenotransfusions but not allotransfusions.These increases were particularly notable in ReXTf and negatively correlated with Hb levels on post-transfusion day 1 (ρ = –0.547 and –0.556; P = 0.0187 and 0.0165, respectively).In TKO/hCD55.hCD39 pig RBC transfusions, C3a and factor Bb peak levels were delayed until post-transfusion day 3, unlike in TKO pig RBC transfusions. Conclusions Post-transfusion complement activation varies depending on prior sensitization and genetic modifications in pig RBCs. Monitoring complement activation can provide insight into the survival and compatibility of transfused RBCs in NHPs.

Although oxidative stress is the main pathophysiology of the development of diabetic neuropathy, oral administration of antioxidants has given disappointing results. Here, we hypothesized that local delivery of antioxidants would provide protective effects on Schwann cells due to the high concentration of local lesions. We prepared alpha-tocopherol (ATF)-loaded liposomes and tested their skin penetration after sonication. An in vitro study using IMS-32 cells was conducted to determine the level of reactive oxygen species (ROS) scavenging effects of ATF-liposomes. ATF reduced ROS in high-glucose-exposed IMS-32 cells in a dosedependent manner. ATF-liposomes also reduced the ROS level in vitro and ultrasound irradiation enhanced delivery to the dermis in porcine ear skin. This study showed that it is feasible to deliver ATF through the skin and can effectively reduce ROS. This model is worthy of development for clinical use.

Background: Severe acute respiratory syndrome coronavirus 2, an RNA virus, exhibits variations in transmission power, severity rate, and vaccine effectiveness due to its mutable nature. We investigated the field epidemiological characteristics of the delta and omicron variants of coronavirus disease 2019 (COVID-19) clusters in a long-term care hospital. Materials and Methods: This study aimed to investigate the incidence, fatality, and vaccination effectiveness of confirmed COVID-19 cases caused by delta and omicron variants. The investigation focused on patients admitted to two long-term care hospitals in a Seoul autonomous district, comparing and analyzing relevant factors. Results: Among the COVID-19 cases, 101 (34.3%) exhibited delta variants, while 193 (65.4%) showcased omicron variants. The incidence rate of omicron variants, compared to delta variants, was 2.24 times higher (95% confidence interval [CI], 1.68–3.00). This elevation was particularly notable in women across all age groups, patients, workers, and individuals with a history of three or more vaccinations. Deaths were reported in 13 cases (52.0%) with the delta variant and 12 cases (48.0%) with the omicron variant. The fatality rate of the omicron variant, in comparison to the delta variant, was 0.09 times (95% CI, 0.44–2.26), indicating no significant difference. No discernible variations in variables were observed. Conclusion The noteworthy surge in outbreaks among female patients, workers engaged in outdoor activities, and the apparent ineffectiveness of vaccination against omicron mutations underscore the need for careful consideration in formulating quarantine measures.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments. In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics. Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections. Nonsusceptibility to minocycline may occur through the efflux pump, TetB. The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs). We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes. Materials and Methods: Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L). Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes. Results: Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the PK-PD criteria. The minocycline minimum inhibitory concentration (MIC)50 /MIC90 was 1/8 mg/L. tetB was present in 49% of isolates and was associated with a higher minocycline MIC (MIC50/90 2/8 mg/L vs. 1/2 mg/L). No clear correlation was observed between tetB positivity and tigecycline MIC. Nine MLSTs were identified, with significant differences in tetB carriage rates between the major sequence types. Notably, ST191, associated with non-tetB carriage and greater susceptibility to minocycline, declined over the study period (P=0.004), while ST451, associated with tetB carriage, increased. Conclusion tetB was present in 49% of CRAB isolates and was associated with higher MICs and non-susceptibility by both CLSI and PK-PD criteria. However, absence of tetB was not a reliable predictor of minocycline PK-PD susceptibility. Additionally, shifts over time towards genotypes with reduced minocycline susceptibility were observed. Further research is needed to correlate these findings with clinical outcomes and identify additional resistance mechanisms.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.

Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Purpose: This study aimed to evaluate the performance of a clinical ladder system in a tertiary hospital by examining how nurses' clinical competence and perceptions of the system affect organizational commitment. Methods: The study involved 394 nurses working at a tertiary hospital. Data were collected from May 3 to July 10, 2023, using a self-reported questionnaire. Statistical analyses, including descriptive statistics, independent t-tests, one-way ANOVA, Kruskal-Wallis test, Scheffé post-hoc test, Pearson correlation, and hierarchical regression analysis, were performed using SPSS 27.0. Results: Nurses who applied for promotion to the CN III level and current CN III nurses reported higher clinical competence, perceptions of the clinical ladder system, and organizational commitment than those who did not and those at lower levels (p<.001). A positive correlation existed among all independent variables.Controlling for general characteristics, the effects of clinical competence and perceptions of the clinical ladder system explained 49% of organizational commitment variance (Adjusted R 2 =.49, F=33.43, p<.001). Conclusion Greater clinical competence and positive perceptions of the clinical ladder system are likely to enhance organizational commitment, emphasizing its effectiveness in fostering better organizational outcomes.