Purpose: Feeding intolerance (FI) is a prevalent clinically sequential condition in preterm infants. To clarify its relationship with the gut microbiota, we compared microbial diversity and taxonomic composition at 2 and 4 weeks of age in infants born before 32 weeks of gestation. Methods: Between August 2021 and December 2022, we prospectively enrolled infants who delivered before 32 weeks of gestation and were admitted to the neonatal intensive care unit at CHA Bundang Medical Center. Forty-four preterm infants were grouped based on the presence (n=16) or absence (n=28) of FI. Fecal samples were obtained at 2 and 4 weeks after birth and analyzed using 16S rRNA gene sequencing to determine microbial profiles. Results: Microbial α-diversity and β-diversity did not differ significantly between groups at either time point. At the genus level, Staphylococcus was significantly more abundant in the FI group than in the feeding tolerance group at 2 weeks postnatal age (P=0.016). Linear discriminant analysis effect size revealed that Staphylococcus, Pseudomonas, and Escherichia were markedly enriched in the FI group at all time points. Conclusion Early colonization by potentially pathogenic genera, particularly Staphylococcus, may precede the development of FI in preterm infants. These findings highlight the potential microbial composition associated with FI and may provide preliminary insights for future microbiome-targeted research in neonatal care.

BACKGROUND/OBJECTIVES: This study aimed to use plasma metabolites to identify clusters of breast cancer survivors and to compare their dietary characteristics and health-related factors across the clusters using unsupervised machine learning. SUBJECTS/METHODS: A total of 419 breast cancer survivors were included in this crosssectional study. We considered 30 plasma metabolites, quantified by high-throughput nuclear magnetic resonance metabolomics. Clusters were obtained based on metabolites using 4 different unsupervised clustering methods: k-means (KM), partitioning around medoids (PAM), self-organizing maps (SOM), and hierarchical agglomerative clustering (HAC). The t-test, χ2 test, and Fisher’s exact test were used to compare sociodemographic, lifestyle, clinical, and dietary characteristics across the clusters. P-values were adjusted through a false discovery rate (FDR). RESULTS: Two clusters were identified using the 4 methods. Participants in cluster 2 had lower concentrations of apolipoprotein A1 and large high-density lipoprotein (HDL) particles and smaller HDL particle sizes, but higher concentrations of chylomicrons and extremely large very-low-density-lipoprotein (VLDL) particles and glycoprotein acetyls, a higher ratio of monounsaturated fatty acids to total fatty acids, and larger VLDL particle sizes compared with cluster 1. Body mass index was significantly higher in cluster 2 compared with cluster 1 (FDR adjusted-PKM < 0.001; PPAM = 0.001; PSOM < 0.001; and PHAC = 0.043). CONCLUSION The breast cancer survivors clustered on the basis of plasma metabolites had distinct characteristics. Further prospective studies are needed to investigate the associations between metabolites, obesity, dietary factors, and breast cancer prognosis.

Purpose: This study examined associations between timing of marital dissolution, duration since marital dissolution, and self-rated health among marriage immigrants in South Korea who live in single-person households. Methods: This cross-sectional study employed a secondary analysis of data from the 2021 Korean National Multicultural Family Survey. We performed binary logistic regression analyses to examine the relationships between the variables of interest while controlling for social support, economic well-being, psychological well-being, and sociodemographic characteristics. Data from 407 marriage immigrant single-person households were included in the analyses. Results: Marriage immigrants’ self-rated health fluctuated over time but generally exhibited a downward trend following marital dissolution. After controlling for confounders, marital dissolution after age 50 and longer duration since dissolution (e.g., 3-6 years and 9+ years) were associated with increased odds of poor self-rated health. Unemployment and depressive symptoms significantly increased the odds of poor self-rated health, while higher social support had a protective effect. Conclusion Transitioning to singlehood after marital dissolution may have long-term negative health consequences, particularly for those experiencing this transition later in life. Proactive interventions focusing on social support and health resource acquisition within the initial 3 years of separation may be crucial to mitigate health decline.

Background/Aims: Studies on the clinical outcomes after detecting low-grade dysplasia (LGD) in patients with inflammatory bowel disease (IBD) are insufficient. This study evaluated the clinical features, frequency, and risk factors for advanced neoplasia in patients with IBD after an LGD diagnosis. Methods: The medical records of 166 patients with IBD from six university hospitals in Korea from 2010 to 2019 were reviewed retrospectively. LGD was diagnosed in all patients during surveillance. The frequency and risk factors for advanced neoplasia were evaluated, and the clinical features of patients with and without advanced neoplasia were compared. Results: Advanced neoplasia developed in 12 patients (six with large LGD, three with tubulovillous adenoma, and three with high-grade dysplasia), and all cases developed from UC. Patients with advanced neoplasia had significantly higher Mayo scores, and colitis-associated dysplasia was more common than sporadic lesions (83.3% vs. 29.9%; p<0.001). Multivariate analysis showed that colitis-associated LGD significantly increased the risk of developing advanced neoplasia (odds ratio [OR], 10.516; 95% confidence interval [CI], 2.064–53.577). Among patients with colitis-associated lesions, a significant risk factor for advanced neoplasia was a prior history of LGD (OR, 9.429; 95% CI, 1.330–66.863). Conclusions Advanced neoplasia developed in 7.2% of patients with IBD and LGD. Most advanced neoplasms developed from colitis-associated lesions, and the risk was higher in patients with a history of LGD before index colonoscopy.

Background/Aims: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global health, exacerbated metabolic health issues, and altered lifestyle behaviors. This study examined the sex-specific impact of the COVID-19 outbreak on the incidence of metabolic syndrome using data from the Korea National Health and Nutrition Examination Survey (KNHANES). Methods: Data from the KNHANES VII (2018) and VIII (2019–2021), including 15,499 participants, were analyzed. The study population was stratified by sex, and further subdivisions were conducted based on the timeframe relative to the COVID-19 outbreak. Variables such as age, education level, household income, smoking status, and high-risk drinking were analyzed to assess their influence on the prevalence of metabolic syndrome. Results: The overall prevalence of metabolic syndrome significantly increased from 28.11% before the outbreak to 29.69% after the outbreak. Both males and females reported significant increases in waist circumference and fasting glucose levels. Age and education level differentially influenced the prevalence of metabolic syndrome between the sex. Smoking was significantly associated with increased prevalence in males, whereas high-risk drinking was associated with increased prevalence in males and decreased prevalence in females. Conclusions The COVID-19 pandemic has significantly increased the prevalence of metabolic syndrome with notable sex-specific differences. These findings highlight the need for sex-specific public health interventions to mitigate the impact of the pandemic on metabolic health.

Background: The defense and veterans pain rating scale (DVPRS) is a pain assessment tool combining a numerical rating scale (NRS) with descriptive words, colors, and facial expressions. This study aimed to validate the Korean version of the DVPRS (K-DVPRS) for postoperative pain assessment. Methods: This study included patients who underwent elective laparoscopic or robotic abdominal surgery. The original DVPRS was translated into Korean using a forward-backward method. Pain intensities at rest and during coughing were assessed at 24 and 48 hours postoperatively using the NRS and K-DVPRS, respectively. The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire was also used. The validity, reliability, and responsiveness of the K-DVPRS were evaluated. Results: Of the 174 patients screened, 150 were enrolled, and 148 completed the study. The K-DVPRS had strong convergent validity with the NRS at 24 and 48 hours postoperatively (ρ: 0.75 to 0.78, all P < 0.001). Construct validity was confirmed by significant differences in pain scores based on surgical extent and duration. The internal consistency was acceptable (Cronbach’s alpha: 0.77 and 0.85 at 24 and 48 hours, respectively), and test-retest reliability at 24 hours was excellent (intraclass correlation coefficient: 0.90 at rest and 0.95 during coughing).Responsiveness, measured by Cliff’s effect size, was high from preoperative to 24 hours postoperatively and moderate from 24 to 48 hours. At 48 hours, the K-DVPRS had stronger correlations with the EQ-5D-5L index and EQVAS than with the NRS. Conclusions The K-DVPRS is a valid, reliable, and responsive tool for assessing postoperative pain in Korean patients.

Background: Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD. Methods: This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests. Results: Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030). Conclusion This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.

Background: The oxygen reserve index (ORi) noninvasively measures oxygen levels within the mild hyperoxia range. To evaluate whether a degree of increase in the ORi during preoxygenation for general anesthesia is associated with the occurrence of postoperative pulmonary complications (PPCs). Methods: We enrolled 154 patients who underwent preoperative pulmonary function tests and were scheduled for elective surgery under general anesthesia. We aimed to measure the increase in ORi during preoxygenation before general anesthesia and analyze its association with PPCs. Results: PPCs occurred in 76 (49%) participants. Multivariate logistic regression analysis revealed that the three-minute preoxygenation ORi was significantly associated with PPCs (Odds ratio [OR]: 0.02, 95% CI [0.00–0.16], P < 0.001). The areas under the curve (AUC [95% CI]) in the receiver operating characteristic curve analysis for the three-minute preoxygenation ORi for PPCs were 0.64 (0.55–0.73). After a subgroup analysis, multivariate logistic regression showed that the three-minute preoxygenation ORi was significantly associated with PPCs among patients who underwent thoracic surgery (OR: 0.01, 95% CI [0.00–0.19], P = 0.006). The AUC of the three-minute preoxygenation ORi for PPCs was 0.72 (0.57–0.86) in patients who underwent thoracic surgery. Conclusions A low ORi measured after 3 min of preoxygenation for general anesthesia was associated with an increased risk of PPCs, including those undergoing thoracic surgery. This study demonstrated the potential of ORi, measured after oxygen administration, as a tool for evaluating lung function that complements traditional lung function tests and scoring systems.

Purpose: This study was conducted to update the practice guidelines for intravenous infusion therapy published in 2017, focusing on the most recent evidence for peripheral intravenous infusion therapy. Methods: The guideline update was conducted using the 22-step methodology. Results: The updated guidelines consist of 17 domains and 235 recommendations (including 284 sub-recommendations). The domains are as follows: general instructions (5 items), peripheral catheter selection (7), catheter insertion site selection (11), management during peripheral catheter insertion (10), post-insertion management (30), perfusion and locking (17), blood sampling via peripheral catheters(6), exchange and removal of peripheral catheters (6), infusion set management (14), add-on devices (32), complications (25), chemotherapy infusions (10), PCA infusions (7), parenteral nutrition (20), transfusion therapy (23), education (5), and documentation and reporting (7). The evidence levels for these recommendations are as follows: 27(9.5%) at level I, 3 (1.1%) at level I A/P, 118 (41.5%) at level II, and 136 (47.9%) at level III.Recommendation grades are categorized as follows: 30 (10.6%) at level A, 118 (41.5%) at level B, and 136(47.9%) at level C. Of these, 73 (25.7%) recommendations were newly developed, 49 (17.3%) underwent major revisions, and 147 (51.7%) underwent minor revisions. Conclusion The updated practice guideline, based on the latest evidence, is anticipated to enhance nursing practice related to peripheral intravenous infusion therapy.

Background: The 5th edition of WHO classification (WHO5) renamed pituitary adenoma as pituitary neuroendocrine tumor (PitNET), aligning with NET nomenclature from other sites.This study investigated the clinicopathological characteristics of surgically resected PitNET based on the WHO5 classification. Methods: A retrospective analysis was conducted on 210 cases of surgically resected and pathologically confirmed PitNET treated at Seoul National University Hospital from 2021 to 2023. The tumors were graded using the French five-tiered grading system proposed by Trouillas et al. Detailed information on grade 3 metastatic PitNET cases is provided. Results: The cohort’s median age was 53 years (age range: 8–84 years), with a male-to-female ratio of 1:1.1. Mean tumor size was 2.5 cm (range: 0.1–6.5 cm). Macroadenomas predominated (91.9%), followed by microadenoma (6.7%), and giant tumors (1.4%), with 56.2% extending suprasellarly. SF1-lineage PitNET was most prevalent (49.5%), followed by PIT1-lineage (23.3%) and TPIT-lineage (17.1%). Null cell tumors (5.7%) and unclassified plurihormonal PitNET (4.3%) were rare. PIT1-lineage PitNET comprised somatotrophs (47.0%), mature plurihormonal PIT1 lineage tumors (18.4%), thyrotrophs (16.3%), immature PIT1-lineage tumors (16.3%), and acidophilic stem cell tumors (n=1), however, there was no lactotroph PitNET. Among SF1-lineage tumors, serologically non-functional tumors predominated (79%), while, immunohistochemically, 71.2% were gonadotrophin (FSH/LH)-positive.Tumor grades by the French five-tiered classification system were distributed as follows:grade 1a (58.1%), 1b (17.6%), 2a (16.2%), 2b (7.1%), and 3 (1.0%). Two cases of metastatic corticotroph PitNET were observed: The first case, a 50-year-old female had liver metastasis and experienced tumor recurrence 7 years after his initial diagnosis of PitNET, ultimately dying 9.5 years later. The primary tumor appeared bland, but the metastatic tumor exhibited a high mitotic rate and a Ki-67 index was 48%. The second case involved a 44-year-old man with metastases to the paranasal sinus, liver, and bone. Despite showing initial bland histopathology and a low proliferation index, this tumor displayed aggressive behavior.The patient had a recurrence 1.5 years after diagnosis, with additional metastases emerging 3 years later. He survived for 8.0 years and is currently disease-free following surgery, chemotherapy, and radiotherapy. Conclusion This comprehensive analysis of surgically resected PitNETs using the new WHO5 classification provides valuable insights into the distribution of the subtypes in the surgical cohort. Key findings were the predominant gonadotroph PitNET, the absence of lactotroph PitNET, and the rarity of null cell tumors in surgical cases. The lack of lactotrophs was mainly due to medical treatment. This study highlights the discrepancy between serological and immunohistochemical findings of SF1-lineage PitNETs. While metastatic PitNET cases showed poor prognosis, the predictive value of the French grading system for PitNET requires further validation through extended follow-up.