Specific sensitivity of the skin to ultraviolet B (UVB) rays is one of the mechanisms responsible for widespread skin damage. This study tested whether 1,3,5-trihydroxybenzene (THB), a compound abundant in marine products, might inhibit UVB radiationinduced NADPH oxidase 4 (NOX4) in both human HaCaT keratinocytes and mouse dorsal skin and explore its cytoprotective mechanism. The mechanism of action was determined using western blotting, immunocytochemistry, NADP + /NADPH assay, reactive oxygen species (ROS) detection, and cell viability assay. THB attenuated UVB-induced NOX4 expression both in vitro and in vivo, and suppressed UVB-induced ROS generation via NADP + production, resulting in increased cell viability with decreased apoptosis. THB also reduced the expression of UVB-induced phosphorylated AMP-activated protein kinase (AMPK) and phosphorylated c-Jun N-terminal kinase (JNK). THB suppressed UVB-induced NOX4 expression and ROS generation by inhibiting AMPK and JNK signaling pathways, thereby inhibiting cellular damage. These results showed that THB could be developed as a UV protectant.

Background: This study aimed to investigate the changes of incidence and treatment of choice for hyperthyroidism from 2003 to 2018 and explore the treatment-related complications and concomitant comorbidities in South Korea using data from the National Health Insurance Service. Methods: This is a retrospective observational study. Hyperthyroidism was defined as a case having two or more diagnostic codes of thyrotoxicosis, with antithyroid drug intake for more than 6 months. Results: The average age-standardized incidence of hyperthyroidism from 2003 to 2018 was 42.23 and 105.13 per 100,000 men and women, respectively. In 2003 to 2004, hyperthyroidism was most often diagnosed in patients in their 50s, but in 2017 to 2018, people were most often diagnosed in their 60s. During the entire period, about 93.7% of hyperthyroidism patients were prescribed with antithyroid drugs, and meanwhile, the annual rates of ablation therapy decrease from 7.68% in 2008 to 4.56% in 2018. Antithyroid drug-related adverse events, mainly agranulocytosis and acute hepatitis, as well as complications of hyperthyroidism such as atrial fibrillation or flutter, osteoporosis, and fractures, occurred more often in younger patients. Conclusion In Korea, hyperthyroidism occurred about 2.5 times more in women than in men, and antithyroid drugs were most preferred as the first-line treatment. Compared to the general population, hyperthyroid patients may have a higher risk of atrial fibrillation or flutter, osteoporosis, and fractures at a younger age.

Objectives: . Thyroid cancer is the most common endocrine tumor, with rapidly increasing incidence worldwide. However, its transcriptomic characteristics associated with immunological signatures, driver fusions, and recurrence markers remain unclear. We aimed to investigate the transcriptomic characteristics of advanced papillary thyroid cancer. Methods: . This study included 282 papillary thyroid cancer tumor samples and 155 normal samples from Chungnam National University Hospital and Seoul National University Hospital. Transcriptomic quantification was determined by high-throughput RNA sequencing. We investigated the associations of clinical parameters and molecular signatures using RNA sequencing. We validated predictive biomarkers using the Cancer Genome Atlas database. Results: . Through a comparison of differentially expressed genes, gene sets, and pathways in papillary thyroid cancer compared to normal tumor-adjacent tissue, we found increased immune signaling associated with cytokines or T cells and decreased thyroid hormone synthetic pathways. In addition, patients with recurrence presented increased CD8+ T-cell and Th1-cell signatures. Interestingly, we found differentially overexpressed genes related to immune-escape signaling such as CTLA4, IDO1, LAG3, and PDCD1 in advanced papillary thyroid cancer with a low thyroid differentiation score. Fusion analysis showed that the PI3K and mitogen-activated protein kinase (MAPK) signaling pathways were regulated differently according to the RET fusion partner genes (CCDC6 or NCOA4). Finally, we identified HOXD9 as a novel molecular biomarker that predicts the recurrence of thyroid cancer in addition to known risk factors (tumor size, lymph node metastasis, and extrathyroidal extension). Conclusion . We identified a high association with immune-escape signaling in the immune-hot group with aggressive clinical characteristics among Korean thyroid cancer patients. Moreover, RET fusion differentially regulated PI3K and MAPK signaling depending on the partner gene of RET, and HOXD9 was found to be a recurrence marker for advanced papillary thyroid cancer.

The targeting of DNA methylation in cancer using DNA hypomethylating drugs has been well known to sensitize cancer cells to chemotherapy and immunotherapy by affecting multiple pathways. Herein, we investigated the combinational effects of DNA hypomethylating drugs and ionizing radiation (IR) in human sarcoma cell lines both in vitro and in vivo. Clonogenic assays were performed to determine the radiosensitizing properties of two DNA hypomethylating drugs on sarcoma cell lines we tested in this study with multiple doses of IR. We analyzed the effects of 5-aza-dC or SGI-110, as DNA hypomethylating drugs, in combination with IR in vitro on the proliferation, apoptosis, caspase-3/7 activity, migration/invasion, and Western blotting using apoptosis- or autophagy-related factors. To confirm the combined effect of DNA hypomethylating drugs and IR in our in vitro experiment, we generated the sarcoma cells in nude mouse xenograft models. Here, we found that the combination of DNA hypomethylating drugs and IR improved anticancer effects by inhibiting cell proliferation and by promoting synergistic cell death that is associated with both apoptosis and autophagy in vitro and in vivo. Our data demonstrated that the combination effects of DNA hypomethylating drugs with radiation exhibited greater cellular effects than the use of a single agent treatment, thus suggesting that the combination of DNA hypomethylating drugs and radiation may become a new radiotherapy to improve therapeutic efficacy for cancer treatment.

Objective: This study evaluated the anxiety, work, and socioeconomic burden of emergency physicians (EP) during the coronavirus disease 2019 (COVID-19) pandemic in South Korea. Methods: A cross-sectional observational study was conducted using data from the 2020 Korean Emergency Physician Survey that included the following domains: hospital resources of suspected COVID-19 patients, availability of personal protective equipment, levels of home and workplace anxiety, the severity of work burnout, identification of stressors, changes in personal environments, and measures to decrease stress/anxiety. Results: Totally, 855 eligible participants were enrolled in the study. A statistically significant deterioration was observed in response to decreased working income or an unstable employment situation (0.46±0.88 points). The median number of patients with confirmed COVID-19 was 2.72. The risk of infection during emergency department (ED) work was found to be significantly increased (P<0.01). Of the 751 respondents (91.4%) who reported patient contact during their survey phase, 516 (62.8%) reported having taken the COVID-19 reverse transcription polymerase chain reaction test. The major factors that affected worsening of the work burden were determined to be unsuitable inter-hospital transfer arrangements for febrile patients (3.46±1.06 before vs. 1.99±1.16 after the pandemic, P<0.01) and delayed consultation for patients with fever or respiratory symptoms in the ED (3.20±1.06 before vs. 2.66±1.10 after the pandemic, P<0.01). Conclusion During the peak phase, the COVID-19 pandemic induced substantial workplace and socioeconomic burdens for Korean EPs. The sustained impact of the pandemic on the wellness of EPs deserves further investigation to guide targeted interventions.

Objective: Machine learning is emerging as a new alternative in various scientific fields and is potentially a new method of interpretation. Using the Light Gradient Boosting Machine (LightGBM), we analyzed the factors that influence the rechoice of emergency medicine responders. The survey is a cross-sectional study which provides an accurate understanding of a responder's current status. However, the results may vary depending on the composition, format, and question, and the relationship between the answers may be unclear. Methods: This study evaluated the modified 2020 Korean Emergency Physician Survey raw data. We applied the preferred model for random relationship check, random forest, support vector machine, and LightGBM models. The stacking ensemble model was used for the final decision process. Results: ‘It is fun working in an emergency room’was the most selected response factor for re-choice, followed by ‘interesting major’. The physical burden of age and lack of identity had a negative impact, whereas burnout and emotional stress factors had a lesser effect. Anxiety caused by the coronavirus disease 2019 (COVID-19) is thought to have a significant impact on this decision making. Conclusion Establishing the identity of emergency medicine and being faithful to its fundamental mission is a way to increase the rate of re-choice. Decreasing the burden of workload modified according to age is recommended to establish career longevity. The method of machine learning presents us with a new possibility of checking the relevance of survey results quickly and easily.

Objective: It has been reported that emergency physicians experience high levels of depression and psychological burnout due to night shifts and tend to consider early retirement. This study intended to check working hours and intensity, individual health, satisfaction, and overall welfare, given the increase in the numbers of emergency physicians. Methods: The study used the results of the ‘2020 Korean Emergency Physician Survey (KEPS)’ conducted from January 15 to February 26, 2021, which targeted 2,138 emergency physicians registered with the Korean Society of Emergency Medicine. The survey was conducted online through the web and mobile application. Results: One thousand three hundred seven out of the 2,167 emergency physicians (60.3%) registered at the society responded. The average age of the respondents was 42.6 years, and there were 1,148 male emergency physicians and 158 female emergency physicians. The average professional experience was 8.2 years, with 325 professors, 122 commissioned doctors, 648 public servants of which 90 had military service, and 45 medical practitioners. Conclusion In conclusion, the number of working hours of emergency physicians showed a decreasing trend compared to 2010 and 2015. However, emergency physicians often expected early retirement. This suggests that, while the absolute working hours are decreasing, the actual working intensity has not decreased. For the proper development of the emergency medical system, it is necessary to establish a stable working environment for emergency physicians. A systematic study is needed on the working hours and work intensity of emergency physicians.

Objective: As the history of emergency medicine grows longer, emergency medicine specialists are observed to comprise various age groups. There have been no prior studies on the generation shift analysis of emergency medicine specialists. Our study is designed to identify the characteristics of each generation and predict the generation shift in emergency medicine physicians. Methods: The analysis was based on the results of the 2020 survey of emergency medicine specialists. The study was conducted on 1,307 respondents and finally, the responses of 967 people were analyzed after excluding 199 who were not in charge of emergency room treatments and 141 who gave incomplete responses. The respondents were divided into four groups based on the following generations: first generation (1996-1999), second generation (2000-2008), third generation (2009-2014), and fourth generation (2015-2020), classified by the year in which they acquired their emergency medicine board license. The intergenerational difference analysis was done using the Kruskall-Wallis test. Results: The first generation was characterized by a high proportion of university hospital professors, large non-clinical activity hours, a few night shifts, higher social contributions, low satisfaction with the training and education environment, and a high retirement age compared to the later generations. In the second generation, the characteristics of the first, third, and fourth generations were generally mixed. The third and fourth generations showed similar characteristics overall, though there were differences in some categories. Conclusion There were significant differences by generation in the working environments, motivation for application, and retirement age. This is the first study that quantifies generational differences. Considering these trends, a discussion about the work environment needs to be initiated.

Objective: Emergency physicians are constantly exposed to night shifts and stress due to the nature of their work, resulting in health problems such as substance abuse, depression, and suicidal ideation. To date, depression in Korean emergency physicians has never been investigated. The present study endeavors to identify the prevalence and factors related to depression in emergency physicians in Korea. Methods: The present study retrospectively analyzed data from the 2020 Korean Emergency Physician Survey. The prevalence of depression was evaluated using the PHQ-9 (Patient Healthcare Questionnaire-9). Multivariable logistic regression analysis was used to identify the factors related to depression and other variables. Results: The overall response rate of the survey was 61.3% (1,307/2,138). A total of 1,102 respondents completed the PHQ- 9 and were analyzed. The prevalence of depression was 27.0% (95% confidence interval [CI], 27.8-33.6). Following factors were found to be associated with depression: military service as the type of position (odds ratio [OR], 0.316; 95% CI, 0.126- 0.794), schedule satisfaction (OR, 0.523; 95% CI, 0.356-0.769), health perspective (OR, 0.408; 95% CI, 0.252-0.662), weekly exercise (OR, 0.879; 95% CI, 0.774-0.998), sleep quality (OR, 4.728; 95% CI, 3.329-6.715), regular diet (OR, 0.380; 95% CI, 0.239-0.605), nighttime snacking (OR, 1.607; 95% CI, 1.124-2.298), and job satisfaction (OR, 0.456; 95% CI, 0.305-0.682). Conclusion More than a quarter of respondents had depression. Job satisfaction, schedule satisfaction, and a healthy lifestyle were negatively related to depression. However, poor sleep quality showed a significantly positive association, which suggests the necessity for a long-term follow-up.

Objective: Unlike the temporary nature of an emergency resident's job, the position of an emergency physician is one of a lifelong commitment requiring stability and persistence. However, it is hard to pursue a healthy lifestyle because of the 24 hours a day, 7 days a week (24/7) working schedule. The emergency room environment demands high physical and mental stamina, and hence the health problems of emergency physicians have a significant impact on the patient’s outcome. Our study was designed to analyze the emergency physician’s health status and influencing factors based on the data from the 2020 Korean Emergency Physician Survey. Methods: Based on the results of the survey, the factors affecting health were classified into several categories, such as personal character, working conditions, lifestyle, and emotional status. Statistical methods have been used to determine whether these factors can affect self-rated health. Results: The self-rated health worsened for emergency physicians in their 40s rather than in their 30s. However, drinking, smoking, and eating patterns had no effect on self-rated health. Also, the actual number of shifts was observed to bear no relationship with health. Sleeping, wellness, and mood affected self-rated health. Physicians who felt they were unhealthy, expected an early retirement because of the burden of night shifts. Conclusion Emergency physicians in Korea have a low self-rated health status. Mental stress, exercise, and sleep had an impact on the status. Physicians who served long-term night shifts saw a deleterious effect on their sleep and mood, and this damage was cumulative. The career longevity of an emergency physician thus requires a reasonable night shift schedule and age-modified adjustments.