Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

Objective: To investigate the associations between T2-weighted imaging (T2WI) features and clinicopathologic characteristics in invasive breast cancer, as well as their relationship with treatment response to neoadjuvant chemotherapy (NAC). Materials and Methods: This retrospective study included 179 women with invasive breast cancer who underwent preoperative 3T breast MRI between November 2020 and February 2021. Intratumoral T2 signal intensity (SI) and peritumoral edema were graded on T2WI, and T2 relaxation times were calculated both including and excluding necrotic or cystic areas. T2 relaxation times were compared across T2 SI grades using the Kruskal–Wallis test. Associations between T2 features and clinicopathologic factors were assessed using chi-square tests and logistic regression analyses. In patients who received NAC (n = 68), associations between T2 features and NAC outcomes were also evaluated. Results: Higher intratumoral T2 SI and peritumoral edema grades were significantly associated with longer T2 relaxation times (P < 0.001). Intratumoral T2 SI grades were associated with higher clinical T category, axillary lymph node metastasis, and tumor multiplicity (all P < 0.05). Longer intratumoral T2 relaxation times were associated with higher clinical T category, hormone receptor (HR) negativity, and the triple-negative subtype (all P < 0.05), even after excluding necrotic or cystic areas.Higher peritumoral edema grades were associated with advanced clinical T category, HR negativity, and the triple-negative subtype (all P < 0.05). T2 relaxation times of peritumoral edema showed no significant associations, except with higher clinical T category (P = 0.005) and estrogen receptor status (P = 0.030). In the NAC subgroup, higher intratumoral T2 SI grades and longer T2 relaxation times were significantly associated with disease progression during NAC (P < 0.05), but not with non-pathologic complete response. Peritumoral edema showed no significant association with NAC outcomes (P > 0.05). Conclusion T2-weighted MRI features were associated with clinicopathologic factors, including clinical T category, HR status, triple-negative subtype, and disease progression during NAC.

We explored the utility of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) sequencing as a noninvasive diagnostic tool for detecting central nervous system (CNS) involvement in patients with diffuse large B-cell lymphoma (DLBCL). Secondary CNS involvement in DLBCL, although rare (~5% of cases), presents diagnostic and prognostic challenges during systemic disease progression or relapse. Effective treatment is impeded by the blood–brain barrier. This was a prospective cohort study (Samsung Lymphoma Cohort Study III) involving 17 patients with confirmed CNS involvement. High-throughput sequencing was conducted using targeted gene panels designed to detect low-frequency variants and copy number alterations pertinent to lymphomas in ctDNA extracted from archived CSF samples. Despite challenges such as low DNA concentrations affecting library construction, the overall variant detection rate was 76%. Detected variants included those in genes commonly implicated in CNS lymphoma, such as MYD88. The study highlights the potential of CSF ctDNA sequencing to identify CNS involvement in DLBCL, providing a promising alternative to more invasive diagnostic methods such as brain biopsy, which are not always feasible. Further validation is necessary to establish the clinical utility of this method, which could significantly enhance the management and outcomes of DLBCL patients with suspected CNS involvement.

Background: Circulating tumor DNA (ctDNA) is a potential biomarker in pancreatic ductal adenocarcinoma (PDAC). However, studies on residual ctDNA in patients post-chemotherapy are limited. We assessed the prognostic value of residual ctDNA in metastatic PDAC relative to that of carbohydrate antigen 19-9 (CA19-9). Methods: ctDNA analysis using a targeted next-generation sequencing panel was performed at baseline and during chemotherapy response evaluation in 53 patients. Progression-free survival (PFS) and overall survival (OS) were first evaluated based on ctDNA positivity at baseline. For further comparison, patients testing ctDNA-positive at baseline were subdivided based on residual ctDNA into ctDNA responders (no residual ctDNA post-chemotherapy) and ctDNA non-responders (residual ctDNA post-chemotherapy). Additional survival analysis was performed based on CA19-9 levels. Results: The baseline ctDNA detection rate was 56.6%. Although clinical outcomes tended to be poorer in patients with baseline ctDNA positivity than in those without, the differences were not significant. Residual ctDNA post-chemotherapy was associated with reduced PFS and OS. The prognosis of ctDNA responders was better than that of non-responders but did not significantly differ from that of ctDNA-negative individuals (no ctDNA both at baseline and during post-chemotherapy). Compared with ctDNA responses to che-motherapy, a ≥ 50% decrease in the CA19-9 level had less effect on both PFS and OSbased on hazard ratios and significance levels. ctDNA could be monitored in half of the patients whose baseline CA19-9 levels were within the reference range. Conclusions Residual ctDNA analysis post-chemotherapy is a promising approach for predicting the clinical outcomes of patients with metastatic PDAC.

Background: This study investigates changes in infection control organizations and the roles of infection control nurses in healthcare institutions during the prolonged COVID-19 pandemic. It aims to provide evidence for preparing effective responses to future emerging infectious diseases. Methods: A survey was conducted from August 9 to 27, 2021, targeting infection control nurses working in infection control departments of general hospitals in South Korea with more than 100 beds. Results: A total of 118 (38.3%) healthcare institutions responded, and 113 questionnaires ultimately analyzed. Changes in infection control organizations observed during the COVID-19 pandemic included alterations in infection control department staffing (34.5%), work arrangements (92.0%), IT systems development (45.1%), facilities and equipment (92.9%), and systems for responding to emerging infectious diseases (99.1%). Over 50% of infection control tasks were performed either frequently or daily during the pandemic, with the most significant workload increase observed in epidemiological investigations (77.9%). The most challenging task for infection control nurses was establishing and operating epidemic management systems (82.3%). Among personal factors hindering their work, a sense of responsibility for their duties scored the highest (mean 4.73/5 points). The primary structural and environmental barrier was insufficient staffing (mean 4.36/5 points). The most critical need for improving infection control efforts was increased staffing in infection control departments and enhanced administrative support (mean 4.63/5 points). Conclusion The COVID-19 pandemic brought significant changes to infection control organizations and the roles of infection control nurses. Based on the lessons learned, healthcare institutions must systematically restructure infection control organizations and enhance the expertise of infection control nurses to respond effectively to future outbreaks of emerging infectious diseases.

Background: This study investigates changes in infection control organizations and the roles of infection control nurses in healthcare institutions during the prolonged COVID-19 pandemic. It aims to provide evidence for preparing effective responses to future emerging infectious diseases. Methods: A survey was conducted from August 9 to 27, 2021, targeting infection control nurses working in infection control departments of general hospitals in South Korea with more than 100 beds. Results: A total of 118 (38.3%) healthcare institutions responded, and 113 questionnaires ultimately analyzed. Changes in infection control organizations observed during the COVID-19 pandemic included alterations in infection control department staffing (34.5%), work arrangements (92.0%), IT systems development (45.1%), facilities and equipment (92.9%), and systems for responding to emerging infectious diseases (99.1%). Over 50% of infection control tasks were performed either frequently or daily during the pandemic, with the most significant workload increase observed in epidemiological investigations (77.9%). The most challenging task for infection control nurses was establishing and operating epidemic management systems (82.3%). Among personal factors hindering their work, a sense of responsibility for their duties scored the highest (mean 4.73/5 points). The primary structural and environmental barrier was insufficient staffing (mean 4.36/5 points). The most critical need for improving infection control efforts was increased staffing in infection control departments and enhanced administrative support (mean 4.63/5 points). Conclusion The COVID-19 pandemic brought significant changes to infection control organizations and the roles of infection control nurses. Based on the lessons learned, healthcare institutions must systematically restructure infection control organizations and enhance the expertise of infection control nurses to respond effectively to future outbreaks of emerging infectious diseases.

Background: This study investigates changes in infection control organizations and the roles of infection control nurses in healthcare institutions during the prolonged COVID-19 pandemic. It aims to provide evidence for preparing effective responses to future emerging infectious diseases. Methods: A survey was conducted from August 9 to 27, 2021, targeting infection control nurses working in infection control departments of general hospitals in South Korea with more than 100 beds. Results: A total of 118 (38.3%) healthcare institutions responded, and 113 questionnaires ultimately analyzed. Changes in infection control organizations observed during the COVID-19 pandemic included alterations in infection control department staffing (34.5%), work arrangements (92.0%), IT systems development (45.1%), facilities and equipment (92.9%), and systems for responding to emerging infectious diseases (99.1%). Over 50% of infection control tasks were performed either frequently or daily during the pandemic, with the most significant workload increase observed in epidemiological investigations (77.9%). The most challenging task for infection control nurses was establishing and operating epidemic management systems (82.3%). Among personal factors hindering their work, a sense of responsibility for their duties scored the highest (mean 4.73/5 points). The primary structural and environmental barrier was insufficient staffing (mean 4.36/5 points). The most critical need for improving infection control efforts was increased staffing in infection control departments and enhanced administrative support (mean 4.63/5 points). Conclusion The COVID-19 pandemic brought significant changes to infection control organizations and the roles of infection control nurses. Based on the lessons learned, healthcare institutions must systematically restructure infection control organizations and enhance the expertise of infection control nurses to respond effectively to future outbreaks of emerging infectious diseases.

Background: This study investigates changes in infection control organizations and the roles of infection control nurses in healthcare institutions during the prolonged COVID-19 pandemic. It aims to provide evidence for preparing effective responses to future emerging infectious diseases. Methods: A survey was conducted from August 9 to 27, 2021, targeting infection control nurses working in infection control departments of general hospitals in South Korea with more than 100 beds. Results: A total of 118 (38.3%) healthcare institutions responded, and 113 questionnaires ultimately analyzed. Changes in infection control organizations observed during the COVID-19 pandemic included alterations in infection control department staffing (34.5%), work arrangements (92.0%), IT systems development (45.1%), facilities and equipment (92.9%), and systems for responding to emerging infectious diseases (99.1%). Over 50% of infection control tasks were performed either frequently or daily during the pandemic, with the most significant workload increase observed in epidemiological investigations (77.9%). The most challenging task for infection control nurses was establishing and operating epidemic management systems (82.3%). Among personal factors hindering their work, a sense of responsibility for their duties scored the highest (mean 4.73/5 points). The primary structural and environmental barrier was insufficient staffing (mean 4.36/5 points). The most critical need for improving infection control efforts was increased staffing in infection control departments and enhanced administrative support (mean 4.63/5 points). Conclusion The COVID-19 pandemic brought significant changes to infection control organizations and the roles of infection control nurses. Based on the lessons learned, healthcare institutions must systematically restructure infection control organizations and enhance the expertise of infection control nurses to respond effectively to future outbreaks of emerging infectious diseases.

Two open-label, randomized, two-period crossover studies were conducted to investigate the pharmacokinetic (PK) properties, safety, and bioequivalence of the test formulation (KD4004), a new fixed-dose combination (FDC) formulation of dapagliflozin and metformin extended release (XR) tablets, relative to the reference formulation (10 mg dapagliflozin/1,000 mg metformin XR FDC tablet) in healthy subjects under fasting (Part A) and fed (Part B) conditions. After giving the dose, serial blood samples were collected for a period of 48 hours. Primary PK parameters (AUC 0-t and C max ) were used to assess bioequivalence between two dapagliflozin/metformin XR (10/1,000 mg) FDC formulations under fed and fasting conditions. Safety and tolerability were also evaluated. Part A and Part B were completed by 32 and 37 subjects, respectively. Bioequivalence of the two FDC formulations of dapagliflozin and metformin XR tablets was established in both the fasted and the fed conditions as the 90% confidence interval of the ratios of adjusted geometric means for AUC 0-t and C max were contained within the predefined range of 0.800–1.250 bioequivalence criteria. Single-dose administration of dapagliflozin and metformin XR was safe and well tolerated as the two FDC formulations. In conclusion, both FDC formulations of dapagliflozin and metformin XR tablets were bioequivalent in fed and fasted subjects. All treatments were well tolerated.

Purpose: We aimed to identify factors influencing smoking cessation success among cancer patients registered in an inpatient smoking cessation program at a single cancer center. Materials and Methods: The electronic medical records of enrolled patients with solid cancer were retrospectively reviewed. We evaluated factors associated with 6-month smoking cessation. Results: A total of 458 patients with cancer were included in this study. Their mean age was 62.9±10.3 years, and 56.3% of the participants had lung cancer. 193 (42.1%) had not yet begun their main treatment. The mean number of counseling sessions for the participants was 8.4±3.5, and 46 (10.0%) patients were prescribed smoking cessation medications. The 6-month smoking cessation success rate was 48.0%. Multivariate analysis showed that younger age (<65 years), cohabited status, early stage, and the number of counseling sessions were statistically significant factors affecting 6-month smoking cessation success (p<0.05). Initiation of a cessation program before cancer treatment was significantly associated with cessation success (odds ratio, 1.66; 95% confidence interval, 1.02–2.70; p=0.040). Conclusion Smoking cessation intervention must be considered when establishing a treatment plan immediately after a cancer diagnosis among smokers.