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.

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: 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/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.

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.

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.