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: 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.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a 5-year survival low of 2% in advanced cases. Despite being a fatal disease, there is a lack of a good predictor of prognosis which can aid in the management of patients. The tumor microenvironment of PDAC, including immune cells, plays a vital role in the progression and invasiveness of PDAC. Cluster of differentiation 47 (CD47) which has a “don’t eat me signal” to macrophages through receptor signal regulatory protein alpha, prevents immune cell surveillance of cancer cells. This contributes to the immune escape and invasiveness of cancer. Methods: We obtained pancreatic cancer tissue microarray samples from 98 patients treated in Hanyang University Hospital. The diagnosis was proven by a tissue biopsy obtained after surgical resection. Immunohistochemical staining was done using CD47 antibody. Data was analyzed using R software ver. 4.3.3. Results: In a study of 98 patients with PDAC, CD47 expression (54.1%) was significantly correlated with advanced disease stage. Positive CD47 expression was associated with lower overall survival (P = 0.028) and disease-free survival (P = 0.005) in all patients. In advanced-stage patients, CD47 remained a predictor of lower overall survival (P = 0.012) and diseasefree survival (P = 0.023). Multivariate analysis identified positive CD47 expression as an independent factor affecting overall survival (P = 0.048). These results emphasize CD47’s prognostic relevance in PDAC, particularly in advanced stages. Conclusion Positive CD47 expression in PDAC indicates an advanced stage of the disease and independently predicts poor outcomes. This highlights CD47’s role as a crucial prognostic marker in advanced PDAC stages.

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: 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.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a 5-year survival low of 2% in advanced cases. Despite being a fatal disease, there is a lack of a good predictor of prognosis which can aid in the management of patients. The tumor microenvironment of PDAC, including immune cells, plays a vital role in the progression and invasiveness of PDAC. Cluster of differentiation 47 (CD47) which has a “don’t eat me signal” to macrophages through receptor signal regulatory protein alpha, prevents immune cell surveillance of cancer cells. This contributes to the immune escape and invasiveness of cancer. Methods: We obtained pancreatic cancer tissue microarray samples from 98 patients treated in Hanyang University Hospital. The diagnosis was proven by a tissue biopsy obtained after surgical resection. Immunohistochemical staining was done using CD47 antibody. Data was analyzed using R software ver. 4.3.3. Results: In a study of 98 patients with PDAC, CD47 expression (54.1%) was significantly correlated with advanced disease stage. Positive CD47 expression was associated with lower overall survival (P = 0.028) and disease-free survival (P = 0.005) in all patients. In advanced-stage patients, CD47 remained a predictor of lower overall survival (P = 0.012) and diseasefree survival (P = 0.023). Multivariate analysis identified positive CD47 expression as an independent factor affecting overall survival (P = 0.048). These results emphasize CD47’s prognostic relevance in PDAC, particularly in advanced stages. Conclusion Positive CD47 expression in PDAC indicates an advanced stage of the disease and independently predicts poor outcomes. This highlights CD47’s role as a crucial prognostic marker in advanced PDAC stages.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a 5-year survival low of 2% in advanced cases. Despite being a fatal disease, there is a lack of a good predictor of prognosis which can aid in the management of patients. The tumor microenvironment of PDAC, including immune cells, plays a vital role in the progression and invasiveness of PDAC. Cluster of differentiation 47 (CD47) which has a “don’t eat me signal” to macrophages through receptor signal regulatory protein alpha, prevents immune cell surveillance of cancer cells. This contributes to the immune escape and invasiveness of cancer. Methods: We obtained pancreatic cancer tissue microarray samples from 98 patients treated in Hanyang University Hospital. The diagnosis was proven by a tissue biopsy obtained after surgical resection. Immunohistochemical staining was done using CD47 antibody. Data was analyzed using R software ver. 4.3.3. Results: In a study of 98 patients with PDAC, CD47 expression (54.1%) was significantly correlated with advanced disease stage. Positive CD47 expression was associated with lower overall survival (P = 0.028) and disease-free survival (P = 0.005) in all patients. In advanced-stage patients, CD47 remained a predictor of lower overall survival (P = 0.012) and diseasefree survival (P = 0.023). Multivariate analysis identified positive CD47 expression as an independent factor affecting overall survival (P = 0.048). These results emphasize CD47’s prognostic relevance in PDAC, particularly in advanced stages. Conclusion Positive CD47 expression in PDAC indicates an advanced stage of the disease and independently predicts poor outcomes. This highlights CD47’s role as a crucial prognostic marker in advanced PDAC stages.

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.

Purpose: The aim of this study was to investigate the occurrence of dry eye syndrome (DES) in children under 18 years old before and during the COVID-19 pandemic using nationwide population-based cohort analysis. Methods: This study utilized the database provided by the Korea Disease Control and Prevention Agency and the Korean National Health Insurance Service. We used claims-based data for patients diagnosed with COVID-19 between October 8, 2020, and December 31, 2021, and those without a diagnosis of COVID-19. DES cases were defined as having at least one diagnosis of H0411 or H1621 based on the International Classification of Diseases, 10th Revision codes. The primary outcome was the evaluation of the hazard ratio for DES between the COVID-19 season and the non–COVID-19 season. Results: A total of 198,486 individuals from the COVID-19 season cohort and 211,828 individuals from the non–COVID-19 season cohort were included in the study. There were no differences in characteristics between the COVID-19 season cohort and the non–COVID-19 season cohort (all standardized mean difference, <0.1). The cumulative incidence of DES during the COVID-19 season was significantly higher than that during the non–COVID-19 season. The COVID-19 season DES incidence rate was 6,419.64 per 100,000 person-years and non–COVID-19 season DES incidence rate was 5,804.88 per 100,000 person-years. In addition, children aged 13 to 18 years, female sex, those living in metropolitan areas, and those with diabetes mellitus had a higher risk of DES. Conclusions The prevalence of diagnosed DES in children increased during the COVID-19 pandemic compared to previous years. Children aged 13 to 18 years, female sex, those living in metropolitan areas, and those with diabetes mellitus had a higher risk of DES. Further studies are needed to directly analyze the potential factors associated with the increased prevalence of DES.

Purpose: The aim of this study was to investigate the occurrence of dry eye syndrome (DES) in children under 18 years old before and during the COVID-19 pandemic using nationwide population-based cohort analysis. Methods: This study utilized the database provided by the Korea Disease Control and Prevention Agency and the Korean National Health Insurance Service. We used claims-based data for patients diagnosed with COVID-19 between October 8, 2020, and December 31, 2021, and those without a diagnosis of COVID-19. DES cases were defined as having at least one diagnosis of H0411 or H1621 based on the International Classification of Diseases, 10th Revision codes. The primary outcome was the evaluation of the hazard ratio for DES between the COVID-19 season and the non–COVID-19 season. Results: A total of 198,486 individuals from the COVID-19 season cohort and 211,828 individuals from the non–COVID-19 season cohort were included in the study. There were no differences in characteristics between the COVID-19 season cohort and the non–COVID-19 season cohort (all standardized mean difference, <0.1). The cumulative incidence of DES during the COVID-19 season was significantly higher than that during the non–COVID-19 season. The COVID-19 season DES incidence rate was 6,419.64 per 100,000 person-years and non–COVID-19 season DES incidence rate was 5,804.88 per 100,000 person-years. In addition, children aged 13 to 18 years, female sex, those living in metropolitan areas, and those with diabetes mellitus had a higher risk of DES. Conclusions The prevalence of diagnosed DES in children increased during the COVID-19 pandemic compared to previous years. Children aged 13 to 18 years, female sex, those living in metropolitan areas, and those with diabetes mellitus had a higher risk of DES. Further studies are needed to directly analyze the potential factors associated with the increased prevalence of DES.