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.

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.

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.

Objective: To propose the utilization of virtual tooth models (VTMs) created by combining tooth root data from cone-beam computed tomography (CBCT) and crown data gathered through intraoral scanning to assess inter-root distance and angulation during orthodontic treatment when repeated radiographic monitoring becomes necessary. Methods: Patients with planned dental implant placement in edentulous areas during or after orthodontic treatment and who underwent intraoral and CBCT scans at the pretreatment and posttreatment stages were selected. Tooth models were fabricated by merging intraorally scanned crowns with the corresponding CBCT-scanned roots from the pretreatment. Tooth positions posttreatment was estimated by integrating models into posttreatment intraoral scans. Moreover, the actual positions were obtained from posttreatment CBCTs. Discrepancies in the estimated and actual tooth positions, including interradicular distances and inter-root angulations, were compared. Results: The minimum inter-radicular distance between two adjacent teeth demonstrated no significant difference between the estimated and actual tooth positions. The difference in inter-root angulation was not statistically significant. Most interradicular distances measured at each landmark revealed no significant differences between the estimated and actual tooth positions, except at the buccolingual midpoint of the cemento-enamel junction, where a slight discrepancy was observed. Conclusions The tooth position of VTMs demonstrated clinically acceptable accuracy compared to CBCT scans. Additionally, VTMs can benefit both clinicians and patients by enabling accurate assessment of the inter-radicular space for dental implant placement without repeated CBCT scans.

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.

Objective: Cardiac arrest and cardiopulmonary resuscitation (CA/R) lead to whole-body ischemia and reperfusion (IR) injury, causing multiple organ dysfunction, including ischemic spinal cord injury. The thoracic spinal cord levels are crucial for maintaining the sympathetic functions vital for life. This study examined blood-spinal cord barrier (BSCB) leakage and astrocyte endfeet (AEF) disruption and their effects on survival, physiological variables, and neuronal damage/death in the intermediate zone (IMZ) at the seventh thoracic spinal cord level after asphyxial CA/R in rats. Methods: The rats underwent whole-body IR injury by asphyxial CA/R. Kaplan-Meier analysis was conducted to assess the cumulative survival post-CA/R. The histological changes post-CA/R were evaluated using immunohistochemistry, histofluorescence, and double histofluorescence. Results: No significant differences in body weight, mean arterial pressure, and heart rate were found between the sham and CA/R groups post-CA/R. The survival rates in the CA/R group at 12, 24, and 48 hours were 62.58%, 36.37%, and 7.8%, respectively. Neuronal loss and BSCB leakage began 12 hours post-CA/R, increasing with time. Reactive astrogliosis appeared at 12 hours and increased, while AEF disruption around blood vessels was evident at 48 hours. Conclusion The survival rate declined significantly by 48 hours post-CA/R. Neuronal loss and BSCB leakage in the thoracic spinal cord IMZ was evident at 12 hours and significant by 48 hours, aligning with AEF disruption. Neuronal loss in the thoracic spinal cord IMZ post-CA/R may be related to BSCB leakage and AEF disruption.

Endometrial cancer commonly metastasizes to the pelvic and para-aortic lymph nodes, vagina, peritoneum, and lungs. Unusual sites of metastasis include the bone, brain, abdominal wall, muscles, and intra-abdominal organs. To our knowledge, there have been no documented cases of synchronous or metachronous metastasis of endometrial cancer to the renal pelvis or colon. Metastatic tumors in the renal pelvis and colon indicate nonspecific radiological findings, making them difficult to distinguish from primary tumors. We describe a case of a 55-year-old female previously treated for endometrial cancer, who was subsequently found to have metastatic masses in the renal pelvis and colon. The two masses were initially misidentified as primary urothelial carcinoma and colon adenocarcinoma.