1.Clinical Significance of Various Pathogens Identified in Patients Experiencing Acute Exacerbations of COPD: A Multi-center Study in South Korea
Hyun Woo JI ; Soojoung YU ; Yun Su SIM ; Hyewon SEO ; Jeong-Woong PARK ; Kyung Hoon MIN ; Deog Kyeom KIM ; Hyun Woo LEE ; Chin Kook RHEE ; Yong Bum PARK ; Kyeong-Cheol SHIN ; Kwang Ha YOO ; Ji Ye JUNG
Tuberculosis and Respiratory Diseases 2025;88(2):292-302
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.
2.Kernel Conversion Improves the Correlation between the Extent of Emphysema and Clinical Parameters in Chronic Obstructive Pulmonary Disease: A Multicenter Cohort Study
Tai Joon AN ; Youlim KIM ; Hyun LEE ; Hyeon-Kyoung KOO ; Naoya TANABE ; Kum Ju CHAE ; Kwang Ha YOO
Tuberculosis and Respiratory Diseases 2025;88(2):303-309
Background:
Computed tomography (CT) scans are utilized to assess emphysema, a prominent phenotype of chronic obstructive pulmonary disease (COPD). Variability in CT protocols and equipment across hospitals can impact accuracy. This study aims to implement kernel conversion across different CT settings and evaluate changes in the correlation between the emphysema index pre- and post-kernel conversion, along with clinical measures in COPD patients.
Methods:
Data were extracted from the Korea COPD Subgroup Study database, which included CT scan images from 484 COPD patients. These images underwent kernel conversion. Emphysema extent was quantified using the percentage of low-attenuation areas (%LAA-950) determined by a deep learning-based program. The correlation between %LAA-950 and clinical parameters, including lung function tests, the modified Medical Research Council (mMRC), 6-minute walking distance (6MWD), COPD assessment test (CAT), and the St. George’s Respiratory Questionnaire for COPD (SGRQ-c), was analyzed. Subsequently, these values were compared across various CT settings.
Results:
A total of 484 participants were included. Kernel conversion significantly reduced the variance in %LAA-950 values (before vs. after: 12.6±11.0 vs. 8.8±11.9). Post-kernel conversion, %LAA-950 demonstrated moderate correlations with forced expiratory volume in 1 second (r=–0.41), residual volume/total lung capacity (r=0.42), mMRC (r=0.25), CAT score (r=0.12), SGRQ-c (r=0.21), and 6MWD (r=0.15), all of which were improved compared to the unconverted dataset (all p<0.01).
Conclusion
CT images processed through kernel conversion enhance the correlation between the extent of emphysema and clinical parameters in COPD.
3.Clinical Significance of Various Pathogens Identified in Patients Experiencing Acute Exacerbations of COPD: A Multi-center Study in South Korea
Hyun Woo JI ; Soojoung YU ; Yun Su SIM ; Hyewon SEO ; Jeong-Woong PARK ; Kyung Hoon MIN ; Deog Kyeom KIM ; Hyun Woo LEE ; Chin Kook RHEE ; Yong Bum PARK ; Kyeong-Cheol SHIN ; Kwang Ha YOO ; Ji Ye JUNG
Tuberculosis and Respiratory Diseases 2025;88(2):292-302
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.
4.Kernel Conversion Improves the Correlation between the Extent of Emphysema and Clinical Parameters in Chronic Obstructive Pulmonary Disease: A Multicenter Cohort Study
Tai Joon AN ; Youlim KIM ; Hyun LEE ; Hyeon-Kyoung KOO ; Naoya TANABE ; Kum Ju CHAE ; Kwang Ha YOO
Tuberculosis and Respiratory Diseases 2025;88(2):303-309
Background:
Computed tomography (CT) scans are utilized to assess emphysema, a prominent phenotype of chronic obstructive pulmonary disease (COPD). Variability in CT protocols and equipment across hospitals can impact accuracy. This study aims to implement kernel conversion across different CT settings and evaluate changes in the correlation between the emphysema index pre- and post-kernel conversion, along with clinical measures in COPD patients.
Methods:
Data were extracted from the Korea COPD Subgroup Study database, which included CT scan images from 484 COPD patients. These images underwent kernel conversion. Emphysema extent was quantified using the percentage of low-attenuation areas (%LAA-950) determined by a deep learning-based program. The correlation between %LAA-950 and clinical parameters, including lung function tests, the modified Medical Research Council (mMRC), 6-minute walking distance (6MWD), COPD assessment test (CAT), and the St. George’s Respiratory Questionnaire for COPD (SGRQ-c), was analyzed. Subsequently, these values were compared across various CT settings.
Results:
A total of 484 participants were included. Kernel conversion significantly reduced the variance in %LAA-950 values (before vs. after: 12.6±11.0 vs. 8.8±11.9). Post-kernel conversion, %LAA-950 demonstrated moderate correlations with forced expiratory volume in 1 second (r=–0.41), residual volume/total lung capacity (r=0.42), mMRC (r=0.25), CAT score (r=0.12), SGRQ-c (r=0.21), and 6MWD (r=0.15), all of which were improved compared to the unconverted dataset (all p<0.01).
Conclusion
CT images processed through kernel conversion enhance the correlation between the extent of emphysema and clinical parameters in COPD.
5.Predictors for the Development of Hypergastrinemia in Maintenance Treatment for Mild Gastroesophageal Reflux Disease Using a Half-dose Proton Pump Inhibitor
Da Hyun JUNG ; Young Hoon YOUN ; Hye-Kyung JUNG ; Kwang Jae LEE
Journal of Neurogastroenterology and Motility 2025;31(1):119-128
Background/Aims:
Serum gastrin levels may be elevated following proton pump inhibitor (PPI) therapy. We aim to elucidate the predictors for the development of hypergastrinemia in maintenance treatment for mild gastroesophageal reflux disease (GERD) using a half-dose PPI.
Methods:
This study analyzed data from a prospective randomized trial to compare continuous versus on-demand maintenance treatment modalities in patients with mild GERD. Age, sex, body mass index, Helicobacter pylori infection, serum gastrin levels, pepsinogen (PG) I/II ratios, total days of PPI intake, and weight-based PPI dosage (mg/kg) were evaluated.
Results:
Data from 293 patients who completed a randomized trial were analyzed (continuous group, n = 147 vs on-demand group, n = 146). In univariate analysis, age (P < 0.001), H. pylori infection (P = 0.012), baseline gastrin levels (P < 0.001), and baseline PG ratios (P = 0.016) significantly correlated with post-treatment gastrin levels. In multivariate analysis, age, baseline gastrin levels, and baseline PG ratios were independently associated with final serum gastrin levels. In univariate analysis, age (P = 0.018), H. pylori infection (P = 0.028), baseline gastrin levels (P = 0.011), and baseline PG ratios (P = 0.031) significantly correlated with the development of hypergastrinemia. In multivariate analysis, age, baseline gastrin levels, and baseline PG ratios were independently associated with the development of hypergastrinemia.
Conclusion
Old age, high baseline serum gastrin levels, and low baseline PG ratios are significant predictors of the development of hypergastrinemia in maintenance treatment for mild GERD using a half-dose PPI.
6.Long-Term Incidence of Gastrointestinal Bleeding Following Ischemic Stroke
Jun Yup KIM ; Beom Joon KIM ; Jihoon KANG ; Do Yeon KIM ; Moon-Ku HAN ; Seong-Eun KIM ; Heeyoung LEE ; Jong-Moo PARK ; Kyusik KANG ; Soo Joo LEE ; Jae Guk KIM ; Jae-Kwan CHA ; Dae-Hyun KIM ; Tai Hwan PARK ; Kyungbok LEE ; Hong-Kyun PARK ; Yong-Jin CHO ; Keun-Sik HONG ; Kang-Ho CHOI ; Joon-Tae KIM ; Dong-Eog KIM ; Jay Chol CHOI ; Mi-Sun OH ; Kyung-Ho YU ; Byung-Chul LEE ; Kwang-Yeol PARK ; Ji Sung LEE ; Sujung JANG ; Jae Eun CHAE ; Juneyoung LEE ; Min-Surk KYE ; Philip B. GORELICK ; Hee-Joon BAE ;
Journal of Stroke 2025;27(1):102-112
Background:
and Purpose Previous research on patients with acute ischemic stroke (AIS) has shown a 0.5% incidence of major gastrointestinal bleeding (GIB) requiring blood transfusion during hospitalization. The existing literature has insufficiently explored the long-term incidence in this population despite the decremental impact of GIB on stroke outcomes.
Methods:
We analyzed the data from a cohort of patients with AIS admitted to 14 hospitals as part of a nationwide multicenter prospective stroke registry between 2011 and 2013. These patients were followed up for up to 6 years. The occurrence of major GIB events, defined as GIB necessitating at least two units of blood transfusion, was tracked using the National Health Insurance Service claims data.
Results:
Among 10,818 patients with AIS (male, 59%; mean age, 68±13 years), 947 (8.8%) experienced 1,224 episodes of major GIB over a median follow-up duration of 3.1 years. Remarkably, 20% of 947 patients experienced multiple episodes of major GIB. The incidence peaked in the first month after AIS, reaching 19.2 per 100 person-years, and gradually decreased to approximately one-sixth of this rate by the 2nd year with subsequent stabilization. Multivariable analysis identified the following predictors of major GIB: anemia, estimated glomerular filtration rate <60 mL/min/1.73 m2 , and a 3-month modified Rankin Scale score of ≥4.
Conclusion
Patients with AIS are susceptible to major GIB, particularly in the first month after the onset of AIS, with the risk decreasing thereafter. Implementing preventive strategies may be important, especially for patients with anemia and impaired renal function at stroke onset and those with a disabling stroke.
7.The Risk of Dementia after Anesthesia Differs according to the Mode of Anesthesia and Individual Anesthetic Agent
Seung-Hoon LEE ; Won Seok William HYUNG ; Surin SEO ; Junhyung KIM ; Changsu HAN ; Kwang-Yeon CHOI ; HyunChul YOUN ; Hyun-Ghang JEONG
Clinical Psychopharmacology and Neuroscience 2025;23(1):65-75
Objective:
Multiple cohort studies have investigated the potential link between anesthesia and dementia. However, mixed findings necessitate closer examination. This study aimed to investigate the association between anesthesia exposure and the incidence of dementia, considering different anesthesia types and anesthetic agents.
Methods:
This nationwide cohort study utilized data from the South Korean Health Insurance Review and Assessment Service database, covering 62,541 participants, to investigate the correlation between anesthesia exposure and dementia incidence.
Results:
Results revealed an increased risk of dementia in individuals who underwent general (hazard ratio [HR], 1.318;95% confidence interval [CI], 1.061−1.637) or regional/local anesthesia (HR, 2.097; 95% CI, 1.887−2.329) compared to those who did not. However, combined general and regional/local anesthesia did not significantly increase dementia risk (HR, 1.097; 95% CI, 0.937−1.284). Notably, individual anesthetic agents exhibited varying risks; desflurane and midazolam showed increased risks, whereas propofol showed no significant difference.
Conclusion
This study provides unique insights into the nuanced relationship between anesthesia, individual anesthetic agents, and the incidence of dementia. While confirming a general association between anesthesia exposure and dementia risk, this study also emphasizes the importance of considering specific agents. These findings under-score the need for careful evaluation and long-term cognitive monitoring after anesthesia.
8.Surgical Outcomes of Suspension Arthroplasty with Dermal Allograft Interposition after Trapeziectomy: Comparison with Ligament Reconstruction and Interposition Using the Flexor Carpi Radialis Tendon
Shin Woo CHOI ; Joo-Yul BAE ; Hyun June LEE ; Ha Sung PARK ; Yun Jae KIM ; Jae Kwang KIM
Clinics in Orthopedic Surgery 2025;17(2):317-323
Background:
Trapeziectomy with suspension arthroplasty is a reliable treatment for thumb carpometacarpal (CMC) osteoarthritis.We modified the suture suspension technique to add further support to maintain the arthroplasty space by interposition of the dermal allograft. Our aim was to investigate the surgical outcomes of our technique of suspension arthroplasty with dermal allograft interposition (SADI) compared with those of traditional ligament reconstruction with tendon interposition (LRTI) using a half-sling of the flexor carpi radialis (FCR) tendon.
Methods:
This retrospective study enrolled 26 patients (29 thumbs) with thumb CMC arthritis who underwent trapeziectomy with traditional LRTI using the FCR tendon (15 thumbs; LRTI group) or SADI (14 thumbs; SADI group) between January 2017 and May 2022. Patient-reported outcomes (visual analog scale; the Disabilities of the Arm, Shoulder and Hand score; and patient-rated wrist evaluation), grip strength, and scaphometacarpal distance were measured at baseline and 3 and 12 months postoperatively. The operation time was checked by reviewing medical records. All measurements were compared between the 2 groups.
Results:
Between baseline and 12-month postoperative follow-up, all patient-reported outcomes significantly improved in both groups. Patient-reported outcomes, grip strength, and scaphometacarpal distance showed no differences between the 2 groups at all follow-up assessments, except for the scaphometacarpal distance being significantly greater in the SADI group at 3 months postoperatively. The operation time was significantly shorter in the SADI group. No complication was observed in either group.
Conclusions
Our modified suture suspension arthroplasty technique using dermal allograft interposition results in markedly shorter surgical times with similar surgical outcomes compared with those of traditional LRTI using the FCR tendon. This procedure appears to be an effective alternative treatment for thumb CMC arthritis.
9.Comparison of Landmark-Based Versus Transverse Carpal Ligament Penetrating Corticosteroid Injection for Bilateral Carpal Tunnel Syndrome:A Prospective Randomized Trial
Seung Hyun LEE ; Jae Kwang KIM ; Young Ho SHIN
Clinics in Orthopedic Surgery 2025;17(3):497-505
Background:
This study aimed to compare the effectiveness and complications between classic palmaris longus tendon landmark-based corticosteroid injection (CI) and transverse carpal ligament (TCL)-penetrating CI for carpal tunnel syndrome (CTS).
Methods:
We performed a landmark-based CI on one hand and a TCL-penetrating CI on the other side after randomization in 30 consecutive patients with bilateral CTS. The pain visual analog scale (VAS) and the Boston Carpal Tunnel Questionnaire (BCTQ) were assessed at baseline, 4 weeks, and 3 and 6 months after injection. Skin hypopigmentation of the injection site was evaluated using the modified Vancouver scar scale (mVSS). Pain during needle insertion was evaluated using a VAS for each hand.
Results:
The mean patient age was 56 ± 11 years (range, 32–77 years), and 27 patients (90.0%) were women. The pain VAS, BCTQ scores, and the incidence of skin hypopigmentation were not significantly different between the 2 groups after injection, but the mean mVSS scores were significantly higher in the landmark-based CI group at all time points. The pain VAS score during needle insertion was significantly higher in the TCL-penetrating CI group.
Conclusions
When comparing the pain VAS and BCTQ scores, the difference between the 2 groups was not statistically significant. TCL-penetrating CI causes considerable pain during needle insertion but causes less severe skin hypopigmentation than landmark-based CI in CTS treatment.
10.Preclinical testing of a new radiofrequency ablation device in a porcine perianal fistula model
Sunseok YOON ; Jung-Woo CHOI ; Yongtaik SON ; Hyun Soon LEE ; Kwang Dae HONG
Annals of Coloproctology 2025;41(1):84-92
Purpose:
Anorectal fistulas present a treatment challenge, with conventional surgical methods potentially resulting in complications such as fecal incontinence. To improve patient outcomes, more effective and minimally invasive therapies are critically needed. In this study, an optimal porcine model for the creation of anorectal fistulas was developed and used to evaluate the efficacy of radiofrequency ablation (RFA) therapy.
Methods:
Two distinct but related experiments were conducted. In the first experiment, a reliable and standardized porcine anorectal fistula model was developed. In the second, the healing process was assessed, and outcomes were compared between the RFA-treated group and the control group using the established porcine model.
Results:
The results indicated that a 3.5-cm fistula tract length and a 14-day evaluation period following seton removal are optimal for the porcine anorectal fistula model. In the second experiment, the RFA group tended to exhibit better outcomes regarding fistula closure, although the differences were not statistically significant. Histopathologically, no significant difference in inflammation grade was observed between groups; however, scar tissue was more predominant in the RFA group.
Conclusion
The findings suggest that RFA therapy may offer potential benefits in the treatment of anorectal fistulas, as demonstrated using a porcine model. To validate these results and explore the mechanisms of action underlying RFA therapy for anorectal fistulas, further research involving larger sample sizes and a more robust study design is required.

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