Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.

Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.

Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.

Background: and Purpose: This clinical practice guideline provides evidence-based recommendations for treatment of dementia, focusing on cholinesterase inhibitors and N-methyl-D-aspartate (NMDA) receptor antagonists for Alzheimer’s disease (AD) and other types of dementia. Methods: Using the Population, Intervention, Comparison, Outcomes (PICO) framework, we developed key clinical questions and conducted systematic literature reviews. A multidisciplinary panel of experts, organized by the Korean Dementia Association, evaluated randomized controlled trials and observational studies. Recommendations were graded for evidence quality and strength using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Results: Three main recommendations are presented: (1) For AD, cholinesterase inhibitors (donepezil, rivastigmine, galantamine) are strongly recommended for improving cognition and daily function based on moderate evidence; (2) Cholinesterase inhibitors are conditionally recommended for vascular dementia and Parkinson’s disease dementia, with a strong recommendation for Lewy body dementia; (3) For moderate to severe AD, NMDA receptor antagonist (memantine) is strongly recommended, demonstrating significant cognitive and functional improvements. Both drug classes showed favorable safety profiles with manageable side effects. Conclusions This guideline offers standardized, evidence-based pharmacologic recommendations for dementia management, with specific guidance on cholinesterase inhibitors and NMDA receptor antagonists. It aims to support clinical decision-making and improve patient outcomes in dementia care. Further updates will address emerging treatments, including amyloid-targeting therapies, to reflect advances in dementia management.

Background: and Purpose: Dementia subtypes, including Alzheimer’s dementia (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia (FTD), pose diagnostic challenges. This review examines the effectiveness of 18 F-Fluorodeoxyglucose Positron Emission Tomography ( 18 F-FDG PET) in differentiating these subtypes for precise treatment and management. Methods: A systematic review following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines was conducted using databases like PubMed and Embase to identify studies on the diagnostic utility of 18 F-FDG PET in dementia. The search included studies up to November 16, 2022, focusing on peer-reviewed journals and applying the goldstandard clinical diagnosis for dementia subtypes. Results: From 12,815 articles, 14 were selected for final analysis. For AD versus FTD, the sensitivity was 0.96 (95% confidence interval [CI], 0.88–0.98) and specificity was 0.84 (95% CI, 0.70–0.92). In the case of AD versus DLB, 18F-FDG PET showed a sensitivity of 0.93 (95% CI 0.88-0.98) and specificity of 0.92 (95% CI, 0.70–0.92). Lastly, when differentiating AD from non-AD dementias, the sensitivity was 0.86 (95% CI, 0.80–0.91) and the specificity was 0.88 (95% CI, 0.80–0.91). The studies mostly used case-control designs with visual and quantitative assessments. Conclusions 18 F-FDG PET exhibits high sensitivity and specificity in differentiating dementia subtypes, particularly AD, FTD, and DLB. This method, while not a standalone diagnostic tool, significantly enhances diagnostic accuracy in uncertain cases, complementing clinical assessments and structural imaging.

Background: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) exert a substantial burden on patients and healthcare systems; however, data related to the frequency of AECOPD in the Korean population are limited. Therefore, this study aimed to describe the frequency of severe, and moderate or severe AECOPD, as well as clinical and demographic characteristics of patients with chronic obstructive pulmonary disease (COPD) in South Korea. Methods: Data from patients aged > 40 years with post-bronchodilator forced expiratory volume in 1 second (FEV 1 )/forced vital capacity ≤ 70% of the normal predicted value from the Korea COPD Subgroup Study database were analyzed (April 2012 to 2021). The protocol was based on the EXAcerbations of COPD and their OutcomeS International study. Data were collected retrospectively for year 0 (0–12 months before study enrollment) based on patient recall, and prospectively during years 1, 2, and 3 (0–12, 13–24, and 25–36 months after study enrollment, respectively). The data were summarized using descriptive statistics. Results: Data from 3,477 Korean patients (mean age, 68.5 years) with COPD were analyzed.Overall, most patients were male (92.3%), former or current smokers (90.8%), had a modified Medical Research Council dyspnea scale score ≥ 1 (83.3%), and had moderate airflow limitation (54.4%). The mean body mass index (BMI) of the study population was 23.1 kg/m 2 , and 27.6% were obese or overweight. Hypertension was the most common comorbidity (37.6%). The mean blood eosinophil count was 226.8 cells/μL, with 21.9% of patients having ≥ 300 cells/μL. A clinically insignificant change in FEV 1 (+1.4%) was observed a year after enrollment. Overall, patients experienced a mean of 0.2 severe annual AECOPD and approximately 1.1 mean moderate or severe AECOPD. Notably, the rates of severe AECOPD remained generally consistent over time. Compared with patients with no exacerbations, patients who experienced severe exacerbations had a lower mean BMI (21.7 vs.23.1 kg/m2 ; P < 0.001) and lower lung function parameters (all Pvalues < 0.001), but reported high rates of depression (25.5% vs. 15.1%; P = 0.044) and anxiety (37.3% vs. 16.7%; P < 0.001) as a comorbidity. Conclusion Findings from this Korean cohort of patients with COPD indicated a high exacerbation burden, which may be attributable to the unique characteristics of the study population and suboptimal disease management. This highlights the need to align clinical practices with the latest treatment recommendations to alleviate AECOPD burden in Korea.

Purpose: 17β-Estradiol (E2) supplementation suppresses MC38 tumor growth by downregulating the expression of programmed death-ligand 1 (PD-L1). This study aims to figure out the gut microbiota that respond to anti–PD-L1 and/or estrogen treatment in MC38 colon cancer model. Materials and Methods: A syngeneic colon tumor model was developed by injection of MC38 cells into C57BL/6 background male and female mice. Three days before MC38 cells injection, E2 was supplemented to male mice daily for 1 week. Male and female mice with MC38 tumors (50-100 mm3) were injected with anti–PD-L1 antibody. Fresh feces were collected 26 days after injection of MC38 cells and 16S rRNA metagenomics sequencing of DNA extracted from feces was used to assess gut microbial composition. Results: At the taxonomic family level, Muribaculaceae was enriched only in the MC38 male control group. In male mice, linear discriminant analysis effect size analysis at the species level revealed that the four microorganisms were commonly regulated in single and combination treatment with anti–PD-L1 and/or E2; a decrease in PAC001068_g_uc and PAC001070_s (family Muribaculaceae) and increase in PAC001716_s and PAC001785_s (family Ruminococcaceae). Interestingly, in the anti–PD-L1 plus E2 group, a decrease in opportunistic pathogens (Enterobacteriaceae group) and an increase in commensal bacteria (Lactobacillus murinus group and Parabacteroides goldsteinii) were observed. Furthermore, the abundance of Parabacteroides goldsteinii was increased in both males and females in the anti–PD-L1 group. Conclusion Our results suggest that gut microbial changes induced by the pretreatment of estrogen before anti–PD-L1 might contribute to treatment of MC38 colon cancer.

Purpose: Sex hormones are known to affect the gut microbiota. Previously, we reported that endogenous and exogenous testosterone are associated with colorectal cancer (CRC) development and submucosal invasion. In the present study, we investigated whether the gut microbiota is affected by orchiectomy (ORX) and testosterone propionate (TP) administration using an azoxymethane/dextran sulfate sodium (AOM/DSS)-induced CRC mouse model. Materials and Methods: Gut microbiota was evaluated by means of 16S rRNA gene sequencing of stool DNA extracted from feces that were obtained at 13 weeks after AOM injection (from 22-week-old animals) and stored in a gas-generating pouch. Results: The increase in microbial diversity (Chao1 and Phylogenetic Diversity index) and Firmicutes/Bacteroidetes (F/B) ratio upon AOM/DSS treatment in ORX mice was significantly decreased by TP supplementation. The ratio of commensal bacteria to opportunistic pathogens was lower in the TP-administered females and ORX mice than in the AOM/DSS group. Opportunistic pathogens (Mucispirillum schaedleri or Akkermansia muciniphila) were identified only in the TP group. In addition, microbial diversity and F/B ratio were higher in male controls than in female and ORX controls. Flintibacter butyricus, Ruminococcus bromii, and Romboutsia timonensis showed similar changes in the male control group as those in the female and ORX controls. Conclusion In conclusion, testosterone determines the dysbiosis of gut microbiota, which suggests that it plays a role in the sex-related differences in colorectal carcinogenesis.

It is unclear whether young adults with chronic obstructive pulmonary disease (COPD) are at an increased risk of rapid lung function decline. A total of 2,934 Korean adults aged 40–49 years who had consecutive lung function measurements were included. COPD was defined as pre-bronchodilator forced expiratory volume in 1 second (FEV 1 )/forced vital capacity < lower limit of normal. The risk of rapid decline in FEV 1 , defined as ≥ 60 mL/year, was assessed using multivariable logistic regression analysis. In the multivariable model, a significantly higher risk of rapid decline in FEV 1 was observed for the COPD group compared with the non-COPD group (adjusted odds ratio, 1.89; 95% confidence interval, 1.18–2.95), which was especially significant in subjects with FEV 1 less than the median value (< 110%pred) (P interaction = 0.017) and inactive physical activity (P interaction = 0.039). In conclusion, the risk of rapid FEV 1 decline was higher in young adults with COPD than in those without COPD, especially in those with FEV 1 less than the median value and inactive physical activity.

Langerhans cell histiocytosis (LCH) is reported less frequently in adults than in children. The most common site of involvement in adults is the bone, accounting for 30-50% of cases. The gastrointestinal tract is very rare, accounting for approximately 2%. We present a case of Langerhans cell histiocytosis that simultaneously invaded multiple organs, including the stomach and colon, in an adult. A 37-year-old woman with no underlying disease complained of chest discomfort and a palpable right submandibular mass. A right Level II neck mass and mediastinal LN enlargement were confirmed on the pharynx and chest CT scan. Multiple subepithelial masses with central ulceration and erosion were observed in the corpus and fundus on the esophagogastroduodenoscopy and in the right colon on the colonoscopy. The histopathology findings were the same in each tissue biopsied from the stomach, colon, and right neck lymph nodes. Langerhans cells with classical reniform nuclei and prominent eosinophils invaded the normal glands, and S100 and CD1a were positive in the immunohistochemical stain. Gastrointestinal involvement of LCH in adults is rare, asymptomatic,and can involve multiple digestive organs simultaneously, so upper endoscopy and colonoscopy should be considered for a diagnosis.