Purpose: Human epidermal growth factor receptor 2 (HER2) is amplified or overexpressed in various malignancies, including breast and gastric cancers, and is associated with poor prognosis. Although HER2-targeted therapies, such as trastuzumab, improve outcomes in HER2-positive tumors, resistance often develops, and HER2-low tumors remain largely untargeted. Trastuzumab deruxtecan (T-DXd; DS-8201a) is a HER2-targeted antibody-drug conjugate with potent activity in HER2-positive and HER2-low tumors. This study evaluates its antitumor mechanisms and efficacy in HER2-positive, HER2-low, and homologous recombination deficiency (HRD)–associated models. Materials and Methods: Effects of T-DXd were assessed in cancer cell lines with diverse HER2 expression and HRD status. In vivo efficacy was evaluated using a xenograft model derived from HER2-low SNU-601 gastric cancer cells. Results: T-DXd reduced HER2 phosphorylation and downstream signaling (AKT, ERK) in HER2-positive cells. It induced DNA damage accumulation, as evidenced by increased γH2AX and p-Chk1 expression, and triggered apoptosis through cleaved poly(ADP-ribose) polymerase and caspase-3 activation, confirmed by annexin V staining. Similar effects were observed in HER2-low cells, with greater sensitivity in HRD cells. In xenografts, T-DXd reduced tumor volume by up to 80% at 4 mg/kg and 10 mg/kg. Histological analyses showed decreased Ki-67 and increased apoptosis. Furthermore, T-DXd induced G2/M cell cycle arrest and nuclear anaplasia, suggesting disruption of chromosomal stability as a potential antitumor mechanism. No significant toxicity, including body weight loss, was observed. Conclusion These findings highlight T-DXd’s effectiveness in HER2-low and HRD tumors, supporting its broader clinical application, including strategies targeting DNA damage repair pathways.

Background: Korean YouTube videos on dental hygiene cover diverse topics and user reactions. Therefore, this study aimed toidentify the overall trends in YouTube content related to dental hygiene and analyze users’ key interests and emotional responses. Methods: YouTube videos were searched using keywords for “Department of Dental Hygiene” (Chi-wi-saeng-hak-gwa and Chi-wi-saeng-gwa) and “Dental Hygienist” (Chi-gwa-wi-saeng-cha and Chi-wi-saeng-sa). The top 98 videos with the highest number of views were selected and categorized into main themes and sub-themes. Relevant comments were collected through crawling, refinement, and analysis. In total, 246 extracted words were visualized using a word cloud and sentiment analysis was conducted for comments on the top five themes. Results: Although not statistically significant, videos related to “Occupation” were the most frequent, whereas "Major” videos showed higher average views, comments, and likes. By sub-theme, daily vlogs such as “Daily life of professional” had the highest number of videos and comments; school introduction videos such as “Major introduction” had the highest number of views; and informational videos such as “Job hunting tips” had the highest number of likes. Frequently appearing comment words included “Dental clinic,” “Curious,” “Go for it” (Hwa-i-ting), “Study, “Help,” “Employment” and “Patient.” The sentiment analysis showed that neutral responses were the most prevalent in comments across all topics, although positive responses outnumbered negative responses. The topic with the highest positive sentiments was “Daily life of professional.” Conclusion Users showed notable interest in dental hygiene majors and school life and responded most positively to everydaycontent.

Atopic dermatitis (AD) is the most prevalent inflammatory skin condition, with approximately 80% of cases originating in childhood and some emerging in adulthood. In South Korea, the estimated prevalence of AD ranges between 10% and 20% in children and 1% and 3% in adults. Severe/recalcitrant AD manifests as a chronic, relapsing skin disorder, persisting with uncontrolled symptoms even after topical steroid treatment. Corticosteroids and systemic immunosuppression, conventionally the standard care for difficult-to-treat diseases, cause numerous undesirable side effects. When AD persists despite topical steroid application, systemic therapies like cyclosporine or systemic steroids become the second treatment strategy. The desire for targeted treatments, along with an enhanced understanding of AD’s pathophysiology, has spurred novel therapeutic development. Recent advances introduce novel systemic options, such as biological agents and small-molecule therapy, tailored to treat severe or recalcitrant AD. Notably, dupilumab, a monoclonal antibody inhibiting interleukin 4 and 13, marked a transformative breakthrough upon gaining approval from the U.S. Food and Drug Administration (FDA) in 2017, leading to a paradigm shift in the systemic treatment of AD. Furthermore, both dupilumab and Janus kinase inhibitors, including baricitinib, abrocitinib, and tofacitinib, now approved by the Korean FDA, have established their applicability in clinical practice. These innovative therapeutic agents have demonstrated favorable clinical outcomes, effectively addressing moderate to severe AD with fewer side reactions than those associated with previous systemic immunosuppressants. This review summarizes the latest advancements and evidence regarding systemic treatments for AD, including newly approved drugs in Korea.

Objectives: Excess deaths, an indicator that compares total mortality rates before and during a pandemic, offer a comprehensive view of the pandemic’s impact. However, discrepancies may arise from variations in estimating expected deaths. This study aims to compare excess deaths in Korea during the coronavirus disease 2019 pandemic using 3 methods and to analyze patterns using the most appropriate method. Methods: Expected deaths from 2020 to 2022 were estimated using mortality data from 2015-2019 as reference years. This estimation employed 3 approaches: (1) simple average, (2) age-adjusted average, and (3) age-adjusted linear regression. Excess deaths by age, gender, and cause of death were also presented. Results: The number of excess deaths varied depending on the estimation method used, reaching its highest point with the simple average and its lowest with the age-adjusted average. Age-adjusted linear regression, which accounts for both the aging population and declining mortality rates, was considered most appropriate. Using this model, excess deaths were estimated at 0.3% for 2020, 4.0% for 2021, and 20.7% for 2022. Excess deaths surged among individuals in their 20s throughout the pandemic, largely attributed to a rise in self-harm and suicide. Additionally, the results indicated sharp increases in deaths associated with “endocrine, nutritional, and metabolic diseases” and “symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified.” Conclusions Substantial variations in excess deaths were evident based on estimation method, with a notable increase in 2022. The heightened excess deaths among young adults and specific causes underscore key considerations for future pandemic responses.

Purpose: We aimed to assess the real-world efficacy of nab-paclitaxel in metastatic breast cancer patients. Materials and Methods: This is a retrospective study performed in two tertiary referral hospitals in Korea. Patients with metastatic breast cancer treated with nab-paclitaxel (Abraxane®) between March 2016 and March 2020 were enrolled. Results: A total of 102 patients with metastatic breast cancer were included. Patients were heavily pre-treated with a median of four prior lines of chemotherapy (5 lines when including endocrine therapy in hormone-receptor-positive patients), and 66 patients (64.7%) were exposed to taxanes in the metastatic setting. According to St. Gallen molecular subtypes, 36 patients (35.3%) were luminal A, 28 (27.5%) were luminal B, 18 (17.7%) were human epidermal growth factor receptor 2–positive and 20 (19.6%) had triple-negative disease. Fifty patients (49.0%) were treated with a 3-weekly regimen (260 mg/m2 on day 1 every 3 weeks), and 52 (51.0%) were treated with a weekly regimen (100 mg/m2 every week). Objective response rate was 22.9%. After a median follow-up of 22.0 months, median progression-free survival (PFS) was 4.0 months (95% confidence interval [CI], 2.6 to 4.8) and median overall survival was 8.7 months (95% CI, 7.5 to 11.2). Patients treated with weekly regimen had longer PFS compared to 3-weekly regimen (5.5 vs. 2.3 months, p < 0.001). Multivariate analysis revealed the treatment regimen as an independent prognostic factor for PFS. There was no grade 3 or 4 hypersensitivity reaction. Conclusion This real-world data shows that nab-paclitaxel is a reasonable treatment option in heavily pre-treated and/or taxane-exposed metastatic breast cancer patients.

Background: Although the orofacial-function improvement exercise (OFIE; oral exercise) was first introduced in Korea 10 years prior, it is still not covered by medical insurance, and no detailed survey on the dissemination of related programs has been conducted. Therefore, this study investigated the actual status of the education and practice of OFIE among the elderly and at elderly welfare institutions in the Seoul and Gyeonggi Provinces. Methods: Senior citizens aged more than 65 years old, public health centers (total of 69) and elderly welfare institutions (including nursing homes and elderly welfare centers, total of 56) per administrative area in the Seoul and Gyeonggi Provinces were targeted. We analyzed 200 elderly people and 93 institutions who agreed to participate in the survey. For the elderly, general characteristics, experience and route, current practice, and necessity regarding OFIE were investigated. For institutions, the history and plan of education programs on OFIE were investigated. Results: Regardless of the general characteristics, both the rate of experience and practice for OFIE were low overall; moreover, although they felt it was necessary, they had insufficient motivation for its implementation. Moreover, only a few institutions which were operating the education about OFIE regardless of the COVID-19 situation. Conclusion Although OFIE is necessary for the elderly, its distribution remains insufficient. Therefore, further efforts are needed to expand the education and raise the awareness of oral exercise among elderly individuals and senior welfare institutions.

Background: To identify work–family balance and level of happiness among married women dental hygienists in Seoul and Gyeonggi Province. The goal of this study is to use the outcome as basic data to determine the compatibility of dental hygienists with work and family, systems, and improvement of happiness levels. Methods: From July 3 to August 10, 2020, 250 dental hygienists in Seoul and Gyeonggi Province were targeted. The questionnaire comprised 65 questions, including general characteristics (perception of work–family balance, perception of work–family balance system, job satisfaction, parenting type, happiness level) whether or not they were implemented. The results were obtained through a self-control questionnaire. Results: The perception of work–family balance was significantly different in job rank and average income, while that of the work– family balance system had significant differences in workplace type, total work experience, current job work experience, childcare system status, and parental leave period. Happiness level and job satisfaction were significantly different in job rank, average income, and childcare system status. Additionally, the perception of work–family balance and that of the work–family balance system showed a positive correlation with job satisfaction and happiness level. Finally, the perception of married women dental hygienists toward work–family compatibility was determined, where the higher the satisfaction with the job, the higher the level of happiness. Conclusion To improve the work–family balance and job satisfaction of dental hygienists and their levels of happiness, changes in social perception and improvement of the working environment such as proper staffing, flexible work systems, and incentive systems should be considered.

Background: Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification. Methods: Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier). Results: On WHO classification, H&E staining exhibited ‘fair agreement’ (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems. Conclusions Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

A previous pharmacogenomic analysis identified cromolyn, an anti-allergic drug, as an effective anti-fibrotic agent that acts on hepatocytes and stellate cells. Furthermore, cromolyn was shown to be a G protein-coupled receptor 35 (GPR35) agonist. However, it has not been studied whether anti-fibrotic effects are mediated by GPR35. Therefore, in this study, the role of GPR35 in hepatic fibrosis was investigated through the use of lodoxamide, another anti-allergic drug and a potent GPR35 agonist. Longterm treatment with carbon tetrachloride induced hepatic fibrosis, which was inhibited by treatment with lodoxamide. Furthermore, CID2745687, a specific GPR35 antagonist, reversed lodoxamide-mediated anti-fibrotic effects. In addition, lodoxamide treatment showed significant effects on the mRNA expression of collagen Iα1, collagen Iα2, and TGF-β1 in the extracellular matrix. However, a transforming growth factor α (TGF-α) shedding assay revealed lodoxamide not to be a potent agonist of mouse GPR35 in vitro. Therefore, these results showed anti-fibrotic effects of lodoxamide in mice and raise concerns how lodoxamide protects against liver fibrosis in vivo and whether GPR35 is involved in the action.