Purpose: Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN. Materials and Methods: Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods. Results: The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%). Conclusions EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.

Background/Aims: Post-infectious irritable bowel syndrome (PI-IBS) is characterized by chronic gastrointestinal symptoms that arise following an episode of infectious enteritis. The incidence rates vary, ranging from 5% to 32% and the risk factors are not well known. We aim to investigate the incidence and risk factors of PI-IBS in enteritis patients admitted to university hospitals in Korea. Methods: This multi-center prospective study was conducted in patients hospitalized for infectious enteritis. Each patient underwent 1 outpatient visit and 3 telephone surveys during the first year after discharge to determine if PI-IBS occurred within the follow-up period. Results: In the 3-month survey, 7 out of 354 patients (2%) were diagnosed with PI-IBS, and after 1 year, only 1 patient met the criteria for IBS.No statistically significant difference was found between the PI-IBS group and the non-PI-IBS group in terms of age, sex, underlying diseases, medication history, gastrointestinal symptoms, enteritis location, causative strain, hospitalization and treatment periods, and laboratory findings. Female sex (P = 0.003), enteropathogenic Escherichia coli (EPEC) infection (P = 0.044), and a longer total treatment period (P = 0.018) were independent risk factors for diarrhea lasting ≥ 3 months after enteritis. Conclusions The incidence of PI-IBS in Korea was relatively low, and most cases improved over time. No risk factors associated with the development of PI-IBS were found. However, persistent diarrhea after enteritis was associated with female sex, EPEC infection, and severe or long-lasting enteritis. IBS symptoms may persist after severe enteritis but usually improve with time.

We report a rare and diagnostically challenging case of a 39-year-old male patient who presented with symptoms of dizziness and headaches, without any focal neurological symptoms. Initial imaging studies suggested a germ cell tumor, and an endoscopic biopsy led to a preliminary diagnosis of a pineal parenchymal tumor of intermediate differentiation. However, histological evaluation following surgical resection revealed the final diagnosis to be an ectopic pituitary neuroendocrine tumor (PitNET), a condition that is exceedingly rare. Ectopic PitNETs are uncommon tumors that develop outside the normal anatomical location of the pituitary gland. Their atypical presentation often leads to misdiagnosis as other intracranial neoplasms. This case highlights the diagnostic challenges posed by ectopic PitNETs and contributes to the limited literature on this rare condition. It underscores the importance of maintaining a broad differential diagnosis in patients presenting with atypical intracranial neoplasms.

Purpose: Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection. Materials and Methods: Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee. Results: A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors. Conclusion Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.

Objectives: . Head and neck squamous cell carcinoma (HNSCC) exhibits high recurrence rates, particularly in cases of radioresistant HNSCC (RR-HNSCC). Non-thermal plasma (NTP) therapy effectively suppresses the progression of HNSCC. However, the therapeutic mechanisms of NTP therapy in treating RR-HNSCC are not well understood. In this study, we explored the regulatory role of NTP in the RR-HNSCC signaling pathway and identified its signature genes. Methods: . After constructing two RR-HNSCC cell lines, we prepared cell lysates from cells treated or not treated with NTP-activated media (NTPAM) and performed RNA sequencing to determine their mRNA expression profiles. Based on the RNA sequencing results, we identified differentially expressed genes (DEGs), followed by a bioinformatics analysis to identify candidate molecules potentially associated with NTPAM therapy for RR-HNSCC. Results: . NTPAM reduced RR-HNSCC cell viability in vitro. RNA sequencing results indicated that NTPAM treatment activated the reactive oxygen species (ROS) pathway and induced ferroptosis in RR-HNSCC cell lines. Among the 1,924 genes correlated with radiation treatment, eight showed statistical significance in both the cell lines and The Cancer Genome Atlas (TCGA) cohort. Only five genes—ABCC3, DUSP16, PDGFB, RAF1, and THBS1—showed consistent results between the NTPAM data sequencing and TCGA data. LASSO regression analysis revealed that five genes were associated with cancer prognosis, with a hazard ratio of 2.26. In RR-HNSCC cells, NTPAM affected DUSP16, PDGFB, and THBS1 as activated markers within 6 hours, and this effect persisted for 12 hours. Furthermore, enrichment analysis indicated that these three DEGs were associated with the extracellular matrix, transforming growth factor-beta, phosphoinositide 3-kinase/protein kinase B, and mesenchymal-epithelial transition factor pathways. Conclusion . NTPAM therapy exerts cytotoxic effects in RR-HNSCC cell lines by inducing specific ROS-mediated ferroptosis. DUSP16, PDGFB, and THBS1 were identified as crucial targets for reversing the radiation resistance induced by NTPAM therapy, providing insights into the mechanisms and clinical applications of NTPAM treatment in RR-HNSCC.

Background/Aims: Direct-acting antivirals (DAAs) effectively eradicate hepatitis C virus. This study investigated whether metabolic dysfunction influences the likelihood of fibrosis regression after DAA treatment in patients with chronic hepatitis C (CHC). Methods: This multicenter, retrospective study included 8,819 patients diagnosed with CHC who were treated with DAAs and achieved a sustained virological response (SVR) between January 2014 and December 2022. Fibrosis regression was defined as a 20% reduction in noninvasive surrogates for liver fibrosis, such as liver stiffness (LS) measured by vibration-controlled transient elastography (VCTE) and the fibrosis-4 (FIB-4) score. Hypercholesterolemia (h-TC) was defined as >200 mg/dL. Results: The median age of the study population was 59.6 years, with a predominance of male patients (n=4,713, 57.3%). Genotypes 1, 2, and others were confirmed in 3,872 (46.2%), 3,487 (41.6%), and 1,024 (12.2%) patients, respectively. Diabetes mellitus (DM) was present in 1,442 (17.2%) patients and the median LS was 7.50 kPa (interquartile range, 5.30–12.50). Multivariate analysis revealed that the presence of DM and pre-DAA h-TC were independently associated with a decreased probability of fibrosis regression by VCTE. Additionally, pre-DAA h-TC was independently associated with a decreased probability of fibrosis regression by the FIB-4. Conclusions Metabolic dysfunction has an unfavorable influence on fibrosis regression in patients with CHC who achieve SVR after DAA treatment.

Background/Aims: Small bowel capsule endoscopy (SBCE) has become the standard for initial evaluation in the diagnosis of small bowel lesions. Although optimal visualization of the mucosa is important, patients experience difficulty in consuming a large volume of bowel preparation agents. This study aimed to compare the efficacy and safety of 1-L polyethylene glycol (PEG) with ascorbic acid (AA) and 2-L PEG with AA. Methods: In this prospective, multicenter, non-inferiority study, patients who received SBCE were randomly assigned to consume 1-L PEG with AA or 2-L PEG with AA for small bowel preparation. The primary outcome was adequate small bowel visibility quality (SBVQ). The secondary outcomes included diagnostic yield, cecal complete rate, and adverse events. Results: One hundred and forty patients were enrolled in this study, 70 patients per group. In the per-protocol analysis, there were no significant differences in the adequate SBVQ rate (94.0% vs 94.3%; risk difference, –0.3; 95% confidence interval, –8.1 to 7.6; p=1.000), diagnostic yield rate (49.3% vs 48.6%, p=0.936), or cecal complete rate (88.1% vs 92.9%, p=0.338) between the 1-L PEG with AA group and 2-L PEG with AA group. The incidence of adverse events did not differ significantly between the groups (12.9% vs 11.9%, p=0.871). Conclusions One liter-PEG with AA is not inferior to 2-L PEG with AA in terms of adequate SBVQ for SBCE. One liter-PEG with AA can be recommended as the standard method for bowel cleansing for SBCE.

Background/Aims: The study investigated the incidence, risk factors, and clinical outcomes of chronic antibiotic-refractory pouchitis (CARP) in Korean patients with ulcerative colitis (UC). Methods: This single-center retrospective study included patients with UC who underwent total proctocolectomy with ileal pouch-anal anastomosis at the Asan Medical Center in Korea between January 1987 and December 2022. The primary outcomes were endoscopic remission and pouch failure. The Cox’s proportional hazard model was used to identify the risk factors for CARP. Results: The clinical data of 232 patients were analyzed. The most common cause of surgery was steroid refractoriness (50.9%), followed by dysplasia/colorectal cancer (26.7%). Among 74 patients (31.9%) with chronic pouchitis (CP), 31 (13.4%) had CARP, and 43 (18.5%) had chronic antibiotic-dependent pouchitis (CADP). The most frequent endoscopic phenotype was focal inflammation of the pouch (CP, 47.3%; CARP, 35.5%; CADP, 55.8%). Patients with CARP were less likely to use concomitant probiotics than patients with CADP (29.0% vs 72.1%, p<0.01). The endoscopic remission rate of CP, CARP, and CADP was 14.9%, 9.7%, and 18.6%, respectively.The pouch failure rate associated with CP, CARP, and CADP was 13.5%, 16.1%, and 11.6%, respectively. Current smoking status (adjusted hazard ratio [aHR], 2.96; 95% confidence interval [CI], 1.27 to 6.90; p=0.01) and previous use of biologics/small molecules (aHR, 2.40; 95% CI, 1.05 to 5.53; p=0.04) were significantly associated with CARP development. Conclusions UC patients who were current smokers and previously used biologics/small molecules had a higher risk of developing CARP. Concomitant use of probiotics was less likely to be associated with CARP development.