1.Optimizing extraction of microbial DNA from urine: Advancing urinary microbiome research in bladder cancer
Chuang-Ming ZHENG ; Ho Won KANG ; Seongmin MOON ; Young Joon BYUN ; Won Tae KIM ; Yung Hyun CHOI ; Sung-Kwon MOON ; Xuan-Mei PIAO ; Seok Joong YUN
Investigative and Clinical Urology 2025;66(3):272-280
Purpose:
This study aimed to evaluate and optimize microbial DNA extraction methods from urine, a non-invasive sample source, to enhance DNA quality, purity, and reliability for urinary microbiome research and biomarker discovery in bladder cancer.
Materials and Methods:
A total of 302 individuals (258 with genitourinary cancers and 44 with benign urologic diseases) participated in this study. Urine samples were collected via sterile catheterization, resulting in 445 vials for microbial analysis. DNA extraction was performed using three protocols: the standard protocol (SP), water dilution protocol (WDP), and chelation-assisted protocol (CAP). DNA quality (concentration, purity, and contamination levels) was assessed using NanoDrop spectrophotometry.Microbial analysis was conducted on 138 samples (108 cancerous and 30 benign) using 16S rRNA sequencing. Prior to sequencing on the Illumina MiSeq platform, Victor 3 fluorometry was used for validation.
Results:
WDP outperformed other methods, achieving significantly higher 260/280 and 260/230 ratios, indicating superior DNA purity and reduced contamination, while maintaining reliable DNA yields. CAP was excluded due to poor performance across all metrics. Microbial abundance was significantly higher in WDP-extracted samples (p<0.0001), whereas SP demonstrated higher alpha diversity indices (p<0.01), likely due to improved detection of low-abundance taxa. Beta diversity analysis showed no significant compositional differences between SP and WDP (p=1.0), supporting the reliability of WDP for microbiome research.
Conclusions
WDP is a highly effective and reliable method for microbial DNA extraction from urine, ensuring high-quality and reproducible results. Future research should address sample variability and crystal precipitation to further refine microbiome-based diagnostics and therapeutics.
2.Self-Reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire
Hee Kyung YANG ; Shin Hae PARK ; Haeng-Jin LEE ; Sook-Young KIM ; Hyo Jung GYE ; So Young KIM ; Sun Young SHIN ; Key Hwan LIM ;
Korean Journal of Ophthalmology 2024;38(3):194-202
Purpose:
To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population.
Methods:
The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS.
Results:
The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery.
Conclusions
The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.
3.Traumatic hematoma-based pseudoaneurysm of the superficial temporal artery in a 7-year-old boy: a case report
Dae Hwan PARK ; June Key LEE ; Bong Soo BAIK ; Wan Suk YANG ; Sun Young KIM
Archives of Craniofacial Surgery 2023;24(1):32-36
The superficial temporal artery (STA), the terminal branch of the external carotid artery, is divided into the frontal (anterior) and parietal (posterior) branches. The frontal branch of the STA is located superficially on the anterior region of the scalp, making it especially susceptible to trauma. Here, we report a traumatic pseudoaneurysm of the STA in a 7-year-old boy who was injured in a minor car accident. A physical examination showed only a small bruise on the patient’s forehead, and all vital signs were stable at the emergency room of our medical center. A facial computed tomography scan showed no significant findings. However, the boy later re-visited the hospital with slight swelling on the right forehead, and an ultrasonography scan revealed a hematoma near the right temporal artery. The resected hematoma (approximately 2 cm) was diagnosed as a traumatic pseudoaneurysm. Awareness of the possibility of a traumatic pseudoaneurysm in the STA may prevent a circumspect diagnosis in the future.
4.Specialty impact on residents’ perceived quality of life, stress, and job satisfaction: a comparative study
Bo Young KIM ; Inah YOON ; Seong John HAN ; Suk-Kyung HONG ; Sehoon CHOI ; Hyo-Jin KWON ; Eun Key KIM
Annals of Surgical Treatment and Research 2023;105(4):188-197
Purpose:
Specialty choice in residency training has a significant impact on an individual’s career and satisfaction, as well as the supply-demand imbalance in the healthcare system. The current study aimed to investigate the quality of life (QOL), stress, self-confidence, and job satisfaction of residents, and to explore factors associated with such variables, including postgraduate year, sex, and especially specialty, through a cross-sectional survey.
Methods:
An online survey was administered to residents at 2 affiliated teaching hospitals. The survey had a total of 46 items encompassing overall residency life such as workload, QOL, stress, confidence, relationship, harassment, and satisfaction. Related survey items were then reconstructed into 4 key categories through exploratory factor analysis for comparison according to group classification.
Results:
The weekly work hours of residents in vital and other specialties were similar, but residents in vital specialties had significantly more on-call days per month. Residents in vital specialties had significantly lower scores for QOL and satisfaction. Specifically, vital-surgical residents had significantly lower QOL scores and higher stress scores than the other specialty groups. Satisfaction scores were also lowest among vital-surgical residents, with a marginal difference from vital-medical, and a significant difference from other-surgical residents. Female residents had significantly lower satisfaction scores than their male counterparts.
Conclusion
Residents in vital specialties, particularly vital-surgical specialties, experience significantly worse working conditions across multiple dimensions. It is necessary to improve not only the quantity but also the quality of the system in terms of resource allocation and prioritization.
5.The work and socioeconomic burden of emergency physicians in the COVID-19 pandemic: 2020 Korean Emergency Physician Survey
In Hwan YEO ; Mi Jin LEE ; Tae Jin SIM ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):67-75
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.
6.Analysis of factors influencing emergency physician’s choice of specialty again using machine learning method
Jee Young PARK ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):57-66
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.
7.The workload of emergency physician using Korean Emergency Physician Survey
Yoo Sang YOON ; DongWoo SON ; Ji Hun KANG ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Hyung Min LEE ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):49-56
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.
8.Analysis of work, life, and occupation perception of emergency physician by generations
Jun Se PARK ; Beom Sok SEO ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Hyung Min LEE ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):38-48
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.
9.The prevalence and related factors of depression in emergency physicians of Korea: results from the 2020 Korean Emergency Physician Survey
Dae Sung LIM ; Song Yi PARK ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Yoo Sang YOON ; Kyung Hye PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Ji Hun KANG ; Woo Jin JUNG ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):29-37
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.
10.What does it take to work healthy as an emergency physician?
Min Seok JANG ; Hyung Min LEE ; Kwang Hyun CHO ; In Byung KIM ; Mi Jin LEE ; Yoo Sang YOON ; Kyung Hye PARK ; Song Yi PARK ; Hong Jae KIM ; Dong Hoon KEY ; Beom Sok SEO ; Young Min JOO ; Chang Gun JEE ; Suk Jae CHOI ; In Hwan YEO ; Ji Hun KANG ; Woo Jin JUNG ; Dae Sung LIM ; Eu Sun LEE
Journal of the Korean Society of Emergency Medicine 2022;33(4):20-28
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.

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