Background: Research on the relationship between the progression of interstitial lung abnormalities (ILA) and serum biomarkers, including white blood cell differential counts and Krebs von den Lungen-6 (KL-6), is limited. This study aimed to examine the clinical characteristics of patients with ILA and evaluate the association between disease progression and serum biomarkers. Methods: This retrospective cohort study analyzed data from 159 patients (63 with ILA and 74 with interstitial lung diseases) between October 2021 and September 2022. Data collected included clinical characteristics, pulmonary function tests, chest computed tomography (CT), complete blood cell counts, and KL-6 levels. In 52 of these patients who had previously undergone chest CT, the utility of serum biomarkers in reflecting radiologic progression was assessed using receiver operating characteristic curve analysis. Results: Patients with ILA exhibited clinical characteristics similar to those with idiopathic pulmonary fibrosis. Serum KL-6 levels did not correlate with forced vital capacity or diffusing capacity of the lung for carbon monoxide in patients with ILA. Among the 52 patients with ILA, 13 demonstrated radiologic progression. Serum KL-6 displayed moderate predictive performance, with area under the curves ranging from 0.57 to 0.89 (p=0.014) for radiologic progression. Levels of KL-6 greater than 400 U/mL were more frequently observed in patients with radiologic progression (61.5% vs. 20.5%, p=0.006). In multivariate analysis, age and KL-6 were independently associated with radiologic progression in patients with ILA. Conclusion Serum KL-6 levels may serve as a potential indicator of ILA progression in asymptomatic patients. Those with KL-6 levels exceeding 400 U/mL should be closely monitored for radiologic progression.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Objectives: This study investigated changes in toothbrushing in adolescents in response to public health policy changes during coronavirus disease 2019 (COVID-19) focusing on behavioral trends before, during, and after policy enforcement according to socio-demographic subgroups. Methods: Data from the Korean Youth Risk Behavior Survey (2018–2024) were divided into 3 periods: before (2018–2019), during (2020–2022), and after (2023–2024) the implementation of COVID-19 school restrictions. A total of 354 943 middle and high school students were included. The primary outcome variable was self-reported toothbrushing after lunch at school. Multivariable logistic regression was conducted, adjusting for confounders such as sex, academic performance, school level, school type, handwashing, and oral health status (toothache and gum bleeding). Results: The compliance rate for toothbrushing declined significantly during the restriction period across all groups. It varied by sex, school type, school level, health-related behaviors (drinking, smoking, handwashing), and oral health status. Female students, middle schoolers, students in single-sex schools, non-smokers, and those practicing hand hygiene showed higher compliance. After restrictions were lifted, toothbrushing rates improved but remained lower than pre-pandemic levels. Recovery of the toothbrushing rate was observed in most groups, particularly among female students, high schoolers, and those with positive health-related behaviors. However, academic performance and oral health status were not significantly associated with recovery rate in adjusted analyses. Conclusions This study highlights that adolescents’ health behaviors are highly sensitive to environmental and policy changes. Variations in compliance and recovery rates underscore the need for adolescent-centered policies that account for both compliance and recovery, especially during crises such as pandemics.

Biliary tract cancer (BTC) is an uncommon, heterogeneous malignancy with increasing incidence and mortality. Most patients present with advanced disease, which limits curative treatment options and contributes to a poor prognosis. Recent advances in molecular profiling and immuno-oncology have substantially reshaped the therapeutic landscape of BTC by providing deeper insight into its molecular and immunological features. In particular, the incorporation of immune checkpoint inhibitors, such as durvalumab and pembrolizumab, into first-line gemcitabine-cisplatin therapy has demonstrated clinically meaningful survival benefits. Phase III trials, including TOPAZ-1 and KEYNOTE-966, reported significant improvements in overall survival and progression-free survival compared with gemcitabine-cisplatin alone, establishing chemoimmunotherapy as a new standard of care for advanced BTC. The advent of targeted therapies has further expanded treatment options. Agents directed against fibroblast growth factor receptor 2 (FGFR2) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, and human epidermal growth factor receptor 2 (HER2) overexpression have enabled precision-based approaches for patients harboring actionable molecular alterations. These developments highlight the critical role of comprehensive molecular profiling in guiding individualized treatment strategies. Despite these advances, important challenges remain, largely because of the relative rarity of BTC and the inherent limitations of small, heterogeneous study populations. Future research should prioritize large-scale, multicenter, prospective trials to optimize therapeutic sequencing and combination strategies. Furthermore, the routine integration of next-generation sequencing into clinical practice is essential to fully realize the potential of molecularly tailored therapies. This review summarizes the latest evidence on immunotherapy and targeted therapy for BTC and discusses their clinical implications for improving patient outcomes.

Midline palatal fractures compromise maxillary transverse stability and cause oro-nasal communication. We report a successful minimally invasive reconstruction based on AO CMF principles. A 60-year-old male with Le Fort II and midline palatal fractures following a fall exhibited nasal regurgitation. Associated facial fractures were managed conservatively, while the palatal fracture was addressed with a customized acrylic splint fabricated via model-based virtual surgery to restore pre-traumatic occlusion.Intraoperatively, segments were repositioned through manual reduction, followed by intermolar wire ligation and splint fixation. Nasal regurgitation resolved by postoperative day 4. Evaluation at 10 days confirmed anatomical arch width restoration. Stable occlusion was maintained throughout the 6-week splinting period. Closed reduction using customized splints and interdental ligation is an effective, minimally invasive alternative for managing midline palatal fractures, particularly when open reduction is challenging.

Subglottic stenosis (SGS) and tracheal stenosis (TS) are rare conditions that can cause significant breathing difficulties and, if not properly managed, may lead to life-threatening complications. Despite their clinical importance, debate continues regarding the optimal management of adult SGS and TS, and no comprehensive guidelines have been established to date. The Korean Bronchoesophagological Society appointed a task force to develop clinical practice guidelines with the goal of providing evidence-based recommendations for managing SGS and TS in adults. The task force conducted a systematic review of the relevant literature by searching PubMed, Embase, and the Cochrane Library using predefined search terms aligned with key clinical questions. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, which also informed the formulation and reporting of the recommendations. The strength of each recommendation reflects the guideline panel’s confidence that the benefits of an intervention outweigh its risks for eligible patients. After drafting the guidelines, feedback was obtained through Delphi questionnaires completed by members of the Korean Bronchoesophagological Society. Ultimately, the committee developed 17 evidence-based recommendations across four categories: initial evaluation, medical management, surgical treatment, and postoperative management and rehabilitation. These guidelines aim to support clinicians in delivering optimal care to adult patients with SGS and TS.

Background: The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments. Materials and Methods: We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19. Results: During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis. Conclusion Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.

Background/Aims: Self-expandable metallic stents (SEMSs) are widely used as palliative or bridge to surgery treatments in patients with malignant colorectal obstruction (MCO). Stent occlusion is more common with uncovered stents, but stent migration is more common with covered stents. Our purpose was to compare the efficacy and safety of a newly designed covered SEMS with an uncovered proximal flared end (CSEMS-UPF) with that of the conventional uncovered SEMS (UCSEMS) in the treatment of MCO. Methods: This prospective randomized trial was conducted at a tertiary-care academic hospital. We enrolled 87 patients with stage 4 cancer and MCO: colorectal cancer in 60 patients and extracolonic cancer in 27 patients. Insertion of UCSEMS was randomly assigned to 43 patients, and 44 patients received the CSEMS-UPF. The primary outcome was the duration of stent patency after successful placement. The secondary outcomes were the number of patients with technical and clinical success and early and late complications from the stent insertion. Results: The median patency of the stent did not differ between the UCSEMS and CSEMS-UPF groups (484 [231–737] days vs. 216 [66–366] days, P= 0.242). The technical and clinical success rates did not differ significantly between the groups, either (100.0% vs. 93.2%, respectively, P= 0.241; 100.0% vs. 92.7%, respectively, P= 0.112), nor did the early (n = 2 [4.7%] vs. n = 4 [9.8%], P> 0.999) or late (n = 12 [27.9%] vs. n = 15 [36.6%], P> 0.999) stent complication rates differ between the groups. Conclusions The UCSEMS and newly developed CSEMS-UPF are similarly effective treatments for MCO, with no differences in the stent migration or occlusion rates (Clinical trial registration number: NCT02640781).

Background: and Purpose The National Brain Biobank of Korea (NBBK) is a brain bank consortium supported by the Korea Disease Control and Prevention Agency and the Korea National Institute of Health, and was launched in 2015 to support research into neurodegenerative disease dementia (NDD). This study aimed to introduce the NBBK and describes clinicopathological correlations based on analyses of data collected from the NBBK. Methods: Four hospital-based brain banks have been established in South Korea: Samsung Medical Center Brain Bank (SMCBB), Seoul National University Hospital Brain Bank (SNUHBB), Pusan National University Hospital Brain Bank (PNUHBB), and Myongji Hospital Brain Bank (MJHBB). Clinical and pathological data were collected from these brain banks using standardized protocols. The prevalence rates of clinical and pathological diagnoses were analyzed in order to characterize the clinicopathological correlations. Results: Between August 2016 and December 2023, 185 brain specimens were collected and pathologically evaluated (SNUHBB: 117; PNUHBB: 27; SMCBB: 34; MJHBB: 7). The age at consent was 70.8±12.6 years, and the age at autopsy was 71.7±12.4 years. The four-most-common clinical diagnoses were Alzheimer’s disease (AD) dementia (20.0%), idiopathic Parkinson’s disease (15.1%), unspecified dementia (11.9%), and cognitively unimpaired (CU) (11.4%).Most cases of unspecified dementia had a pathological diagnosis of central nervous system (CNS) vasculopathy (31.8%) or AD (31.8%). Remarkably, only 14.2% of CU cases had normal pathological findings. The three-most-common pathological diagnoses were AD (26.5%), CNS vasculopathy (14.1%), and Lewy body disease (13.5%). Conclusions These clinical and neuropathological findings provide a deeper understanding of the mechanisms underlying NDD in South Korea.