Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model, experimental autoimmune encephalomyelitis (EAE). This study investigates the role of high mobility group box 1 (HMGB1) in oligodendrocyte precursor cells (OPCs) in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier (BBB) by using OPC-specific HMGB1 knockout (KO) mice. We found that HMGB1 released from OPCs promotes BBB disruption, subsequently allowing increased immune cell infiltration. The migration of CD4+ T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes (OLs). OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS, leading to less damage to the myelin sheath and mitigated EAE progression. CD4+ T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs. Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
Animals ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; HMGB1 Protein/deficiency* ; Mice, Knockout ; Oligodendrocyte Precursor Cells/immunology* ; Mice, Inbred C57BL ; CD4-Positive T-Lymphocytes/immunology* ; Cell Movement ; Blood-Brain Barrier/immunology* ; Mice ; Myelin Sheath/pathology* ; Disease Models, Animal ; Coculture Techniques ; Oligodendroglia/metabolism* ; Female ; Cells, Cultured

Background: Cutaneous angiosarcoma, a rare malignant tumor, is associated with high mortality and poor prognosis. Objective: This study aimed to analyze the clinicopathologic features of cutaneous angiosarcoma and identify the prognostic factors influencing survival. Methods: Medical records of patients diagnosed with cutaneous angiosarcoma between January 1995 and March 2023 were retrospectively reviewed. Demographic data, clinicopathologic features, and treatment modalities were analyzed to evaluate the correlation with overall survival (OS) and progression-free survival (PFS). A total of 70 patients were included in the study. Results: Their mean age at diagnosis was 71 years (range, 41–91 years). Of them, 57 (81.4%) were males. Five-year OS and PFS rates were 29.0% and 10.7%, respectively. In univariate analysis, a mass in the frontal area of the scalp showed significant associations with poorer PFS (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.07–3.55; p=0.029) and poorer OS (HR, 2.42; 95% CI, 1.22–4.80; p=0.011). Mass size exceeding 3 cm had a notable impact on PFS (HR, 3.41; 95% CI, 1.32–8.82; p=0.011) and remained a significant independent adverse prognosticator in multivariate analysis (HR, 4.55; 95% CI, 1.22–16.99; p=0.024). Conclusion Cutaneous angiosarcoma is characterized by an unfavorable prognosis, with a larger mass size identified as an independent prognostic factor.

Sensitive skin (SS) is increasingly recognized as a complex syndrome characterized by discomfort and heightened sensitivity to otherwise harmless stimuli, such as environmental changes, physical contact, and cosmetic products. This condition poses challenges in both diagnosis and treatment due to its variable presentation and subjective nature. The pathophysiological features of SS include neurogenic inflammation and small fiber neuropathy, largely driven by the hyperactivation of sensory nerves. This hyperactivation is closely associated with transient receptor potential (TRP) channels, particularly TRPV1, which contribute to the exaggerated sensory responses seen in SS. Furthermore, psychological factors like stress and anxiety, along with environmental stressors such as pollution and ultraviolet exposure, play significant roles in exacerbating symptoms. The diverse and individualized responses to stimuli make it difficult to establish standardized diagnostic criteria for SS, necessitating a combination of subjective diagnostic tools (e.g., the Sensitive Scale-10) and objective assessments (e.g., transepidermal water loss and lactic acid sting test) to accurately identify and assess SS. This paper provides a comprehensive review of SS, covering its definition, prevalence, pathogenesis, diagnostic challenges, and management strategies, and highlights the importance of personalized care in effectively managing SS and improving patient quality of life.

Background: There is a growing demand for extending dosing intervals of dupilumab injections in patients with atopic dermatitis (AD) due to treatment burden and side effects. However, studies on successful dose reduction in real-world settings are lacking. Objective: To assess the efficacy of a patient-centered dupilumab tapering regimen and to propose guidelines for target patients, appropriate intervals, and timing for tapering. Methods: This single-center retrospective study included moderate to severe adult AD patients who underwent at least 16 weeks of dupilumab treatment. Interval prolongation was considered in controlled patients assessed by Eczema Area and Severity Index (EASI) score and serum inflammatory markers after at least 40 weeks of treatment with a standard regimen. Logistic regression model with generalized estimating equations was used to compare repetitive measurements over time between the two groups. Results: A total of 52 patients were included with 11 patients extending intervals to 3–4 weeks without flare-ups. The mean duration of dupilumab treatment before tapering was 53.27 weeks. The tapering group exhibited significantly lower body mass index. All patients of the tapering group showed EASI scores under 4 and immunoglobulin E (IgE) levels under 1,000 IU/mL at week 40. EASI scores and IgE levels remained consistently low after dose reduction, with a mean follow-up time of 14.36 months. Conclusion Patients with extended dosing intervals demonstrated sustained effectiveness. Dose tapering might be a valuable option for non-obese patients with positive clinical response characterized by an EASI score under 4 and IgE levels under 1,000 at week 40.

Purpose: The COVID-19 (coronavirus disease 2019) pandemic led to significant changes in clinical clerkships, including reduced ward rounds. We aimed to determine how the pandemic–induced changes in the clinical practice environment affect the clinical performance of medical students. Methods: We analyzed objective structured clinical examination scores of third- and fourth-year medical students from 2019–2020 and 2020–2021 across six stations by the Seoul–Gyeonggi Consortium. Clinical, communication, and ability scores were measured and analyzed using repeated-measures multivariate analysis of variance. Results: The interaction between clinical practice progress and pandemic-induced changes significantly affected physical examination and medical history scores, though the differences were not substantial. Patient-physician interaction significance varied by measurement period. Clinical communication ability also showed significant differences based on the measurement period and practical experience. Conclusion During the pandemic, alternative learning methods, including self–learning, simulation/practice, and peer role–play, helped improve medical competency in areas such as history–taking and physical examination. However, these were less effective in improving patient–physician interactions or clinical communication efficacy. Alternative learning methods have limitations, and they cannot replace direct patient encounters in clinical practice.

Purpose: The COVID-19 (coronavirus disease 2019) pandemic led to significant changes in clinical clerkships, including reduced ward rounds. We aimed to determine how the pandemic–induced changes in the clinical practice environment affect the clinical performance of medical students. Methods: We analyzed objective structured clinical examination scores of third- and fourth-year medical students from 2019–2020 and 2020–2021 across six stations by the Seoul–Gyeonggi Consortium. Clinical, communication, and ability scores were measured and analyzed using repeated-measures multivariate analysis of variance. Results: The interaction between clinical practice progress and pandemic-induced changes significantly affected physical examination and medical history scores, though the differences were not substantial. Patient-physician interaction significance varied by measurement period. Clinical communication ability also showed significant differences based on the measurement period and practical experience. Conclusion During the pandemic, alternative learning methods, including self–learning, simulation/practice, and peer role–play, helped improve medical competency in areas such as history–taking and physical examination. However, these were less effective in improving patient–physician interactions or clinical communication efficacy. Alternative learning methods have limitations, and they cannot replace direct patient encounters in clinical practice.