Background: A healthcare system’s collapse due to a pandemic, such as the coronavirus disease 2019 (COVID-19), can expose healthcare workers (HCWs) to various mental health problems. This study aimed to investigate the impact of the COVID-19 pandemic on the depression and anxiety of HCWs. Methods: A nationwide questionnaire-based survey was conducted on HCWs who worked in healthcare facilities and public health centers in Korea in December 2020. Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure depression and anxiety. To investigate factors associated with depression and anxiety, stepwise multiple logistic regression analysis was performed. Results: A total of 1,425 participating HCWs were included. The mean depression score (PHQ-9) of HCWs before and after COVID-19 increased from 2.37 to 5.39, and the mean anxiety score (GAD-7) increased from 1.41 to 3.41. The proportion of HCWs with moderate to severe depression (PHQ-9 ≥ 10) increased from 3.8% before COVID-19 to 19.5% after COVID-19, whereas that of HCWs with moderate to severe anxiety (GAD-7 ≥ 10) increased from 2.0% to 10.1%. In our study, insomnia, chronic fatigue symptoms and physical symptoms after COVID-19, anxiety score (GAD-7) after COVID-19, living alone, and exhaustion were positively correlated with depression. Furthermore, post-traumatic stress symptoms, stress score (Global Assessment of Recent Stress), depression score (PHQ-9) after COVID-19, and exhaustion were positively correlated with anxiety. Conclusion In Korea, during the COVID-19 pandemic, HCWs commonly suffered from mental health problems, including depression and anxiety. Regularly checking the physical and mental health problems of HCWs during the COVID-19 pandemic is crucial, and social support and strategy are needed to reduce the heavy workload and psychological distress of HCWs.

Background: As the coronavirus disease 2019 (COVID-19) pandemic is ongoing, heavy workload of healthcare workers (HCWs) is a concern. This study investigated the workload of HCWs responding to the COVID-19 outbreak in South Korea. Methods: A nationwide cross-sectional survey was conducted from September 16 to October 15, 2020, involving 16 healthcare facilities (4 public medical centers, 12 tertiary-care hospitals) that provide treatment for COVID-19 patients. Results: Public medical centers provided the majority (69.4%) of total hospital beds for COVID-19 patients (n = 611), on the other hand, tertiary care hospitals provided the majority (78.9%) of critical care beds (n = 57). The number of beds per doctor (median [IQR]) in public medical centers was higher than in tertiary care hospitals (20.2 [13.0, 29.4] versus 3.0 [1.3, 6.6], P = 0.006). Infectious Diseases physicians are mostly (80%) involved among attending physicians. The number of nurses per patient (median [interquartile range, IQR]) in tertiarycare hospitals was higher than in public medical centers (4.6 [3.4–5] vs. 1.1 [0.8–2.1], P =0.089). The median number of nurses per patient for COVID-19 patients was higher than the highest national standard in South Korea (3.8 vs. 2 for critical care). All participating healthcare facilities were also operating screening centers, for which a median of 2 doctors, 5 nurses, and 2 administrating staff were necessary. Conclusion As the severity of COVID-19 patients increases, the number of HCWs required increases. Because the workload of HCWs responding to the COVID-19 outbreak is much greater than other situations, a workforce management plan regarding this perspective is required to prevent burnout of HCWs.

Objective: The aim of this study was to estimate the progress of insomnia prevalence and incidence over the past several years. Also, this study compared survival rates between individuals with and without insomnia. Methods: The National Health Insurance Service-National Sample Cohort (NHIS-NSC) from 2002–2013 was used for this study. Prevalent cases of insomnia were defined using ICD-10 codes F51.0 or G47.0, or a prescription of sedatives. Cox’s proportional hazard analysis was conducted to compare survival rates between insomnia patients and people without insomnia. Results: In 2013, there were 46,167 (5.78%) insomnia patients over 20 years old in this cohort. Insomnia was more common among women and the elderly. Annual incidence over the past several years remained steady but the prevalence increased. The survival of insomnia patients was lower than that of people without insomnia, and the hazard ratio for overall mortality was 1.702 (p<0.001). Conclusion This large-scale population-based cohort study provided current epidemiologic indicators of insomnia in the Korean general population.

OBJECTIVE: The present study aimed to examine the potential mediating effect of income level on the association between noise exposure and insomnia. METHODS: 706 individuals were evaluated in conjunction with 2014 noise map data from Seoul, South Korea. Cross-sectional analysis was performed to examine differences in noise level according to household income, while three separate logistic regression models were used to examine factors influencing insomnia. Odds ratios (ORs) were calculated after adjusting for depression, anxiety, auditory acuity and noise sensitivity in the first model. Analyses were adjusted for sociodemographic variables in the second model, lifestyle factors and medical illnesses in the third model. RESULTS: Noise level was significantly associated with an increased risk of insomnia in the low-income group, although no such association was observed in the high-income group. Groups exposed to >60 dB of noise (Lden; day-evening-night equivalent) exhibited a 1.79-fold increase in the incidence of insomnia relative to those exposed to <50 dB. The result was significant after adjusting sociodemographic variables, although not significant when adjusted for lifestyle factors and medical illnesses. CONCLUSION: Individuals with low income may be more vulnerable to the deleterious effects of noise exposure on health. Various aspects including income should be considered to ascertain the influence of noise on insomnia.
Anxiety ; Cross-Sectional Studies ; Depression ; Family Characteristics ; Incidence ; Korea ; Life Style ; Logistic Models ; Mental Health ; Negotiating ; Noise* ; Odds Ratio ; Seoul ; Sleep Initiation and Maintenance Disorders*

The voltage-gated Na channel subtype Nav1.7 is important for pain and itch in rodents and humans. We previously showed that a Nav1.7-targeting monoclonal antibody (SVmab) reduces Na currents and pain and itch responses in mice. Here, we investigated whether recombinant SVmab (rSVmab) binds to and blocks Nav1.7 similar to SVmab. ELISA tests revealed that SVmab was capable of binding to Nav1.7-expressing HEK293 cells, mouse DRG neurons, human nerve tissue, and the voltage-sensor domain II of Nav1.7. In contrast, rSVmab showed no or weak binding to Nav1.7 in these tests. Patch-clamp recordings showed that SVmab, but not rSVmab, markedly inhibited Na currents in Nav1.7-expressing HEK293 cells. Notably, electrical field stimulation increased the blocking activity of SVmab and rSVmab in Nav1.7-expressing HEK293 cells. SVmab was more effective than rSVmab in inhibiting paclitaxel-induced mechanical allodynia. SVmab also bound to human DRG neurons and inhibited their Na currents. Finally, potential reasons for the differential efficacy of SVmab and rSVmab and future directions are discussed.
Animals ; Antibodies, Monoclonal ; therapeutic use ; Biotin ; metabolism ; Cells, Cultured ; Disease Models, Animal ; Female ; Ganglia, Spinal ; cytology ; HEK293 Cells ; Humans ; Hybridomas ; chemistry ; Hyperalgesia ; drug therapy ; Male ; Mice ; Mice, Inbred C57BL ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism ; NAV1.7 Voltage-Gated Sodium Channel ; chemistry ; immunology ; metabolism ; Neuralgia ; drug therapy ; metabolism ; Protein Binding ; drug effects ; Recombinant Proteins ; biosynthesis ; therapeutic use ; Sensory Receptor Cells ; drug effects ; physiology

BACKGROUND: Industrial pollution may affect the heavy metal body burden of people living near industrial complexes. We determined the average concentrations of atmospheric heavy metals in areas close to and distant from industrial complexes in Korea, and the body concentrations of these heavy metals in residents living near and distant from these facilities. METHODS: The atmospheric data of heavy metals (lead and cadmium) were from the Regional Air Monitoring Network in Ulsan. We recruited 1,148 participants, 872 who lived near an industrial complex (“exposed” group) and 276 who lived distant from industrial complexes (“non-exposed” group), and measured their concentrations of blood lead, urinary cadmium, and urinary total mercury. RESULTS: The results showed that atmospheric and human concentrations of heavy metals were higher in areas near industrial complexes. In addition, residents living near industrial complexes had higher individual and combined concentrations (cadmium + lead + mercury) of heavy metals. CONCLUSION: We conclude that residents living near industrial complexes are exposed to high concentrations of heavy metals, and should be carefully monitored.
Body Burden ; Cadmium ; Environmental Exposure ; Humans ; Korea ; Metals, Heavy ; Ulsan

BACKGROUND: Recently, noise coming from the neighborhood via floor wall has become a great social problem. The noise between the floors can be a cause of physical and psychological problems, and the different types of floor impact sound (FIS) may have the different effects on the human's body and mind. The purpose of this study is to assess the responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact. METHODS: Ten men and 5 women were enrolled in our study, and the English listening test was performed under the twelve different types of FIS, which were made by the combinations of bang machine (B), tapping machine (T), impact ball (I) and sound-proof mattress (M). The 15 subjects were exposed to each FIS for about 3 min, and the subjective annoyance, performance ability (English listening test), cortisol level of urine/saliva and heart rate variability (HRV) were examined. The sound pressure level (SPL) and frequency of FIS were analyzed. Repeated-measures ANOVA, paired t-test, Wilcoxon signed rank test were performed for data analysis. RESULTS: The SPL of tapping machine (T) was reduced with the soundproof mattress (M) by 3.9–7.3 dBA. Impact ball (I) was higher than other FIS in low frequency (31.5–125 Hz) by 10 dBA, and tapping machine (T) was higher than other FIS in high frequency (2–4 k Hz) by 10 dBA. The subjective annoyance is highest in the combination of bang machine and tapping machine (BT), and next in the tapping machine (T). The English listening score was also lowest in the BT, and next in T. The difference of salivary cortisol levels between various types of FIS was significant (p = 0.003). The change of HRV parameters by the change of FIS types was significant in some parameters, which were total power (TP) (p = 0.004), low frequency (LF) (p = 0.002) and high frequency (HF) (p = 0.011). CONCLUSIONS: These results suggest that the human's subjective and objective responses were different according to FIS types and those combinations.
Female ; Heart Rate ; Humans ; Hydrocortisone ; Male ; Noise ; Pilot Projects* ; Residence Characteristics ; Social Problems ; Statistics as Topic ; Task Performance and Analysis*

BACKGROUND: The need of efficient resource management and full-time accessibility to resources has increased with the development of industry, resulting in the increase of shift workers. Previous researches of past decades show that there are various health effects on shift workers. However, the definition and the form of shift work have varied from each research and occupational harmful factors except for shift work have not been excluded completely in previous researches. Therefore, in this research, we tried to find out the effect of shift work focusing on the hypertension. To complement previously mentioned weakness of other researches, we performed our research on participants to whom we could minimize other risk factors excluding shift work. METHODS: This research examined 1,953 petrochemical plant male workers (shift work 1,075, day worker 878) who did medical checkup from 1st Jan. 2014 to 31th Dec. 2014 in a general hospital located in Ulsan, based on their medical records and questionnaires. With the questionnaire, we found out their basic information including age, social status, occupational history, and we took their physical measurements. RESULTS: Compared to day workers, shift workers' odds ratio of developing hypertension was 1.31 (95% CI 0.98–1.75). After adjusting confounding variables, adjusted odds ratio for entire subjects was 1.51 (95% CI 1.11–2.06). Also, for subjects who were in continuous service for over 20 years, odds ratio was 1.51 (95% CI 1.08–2.11). CONCLUSIONS: Shift workers had a higher chance of hypertension than day workers do. Particularly, the longer the workers work continuously, the risk of hypertension getting higher.
Complement System Proteins ; Confounding Factors (Epidemiology) ; Employment ; Hospitals, General ; Humans ; Hypertension* ; Male ; Medical Records ; Odds Ratio ; Plants ; Risk Factors ; Ulsan

BACKGROUND: Lead and cadmium are harmful heavy metals that are used for a variety of occupational purposes. Considering their potentially hazardous effects on health, studies on the association between exposure to these two heavy metals and health disorders have been actively conducted. This study aimed to determine the association between blood lead and cadmium levels and blood pressure in workers exposed to lead and cadmium in a smelter. METHODS: Nine hundred and sixty-three male workers who worked in a smelter, and underwent medical examinations at the Ulsan University Hospital between January 1 and December 31, 2014, were selected as participants. Among them, 310 subjects whose data on height, weight, blood pressure, fasting blood glucose, lipid profile, and blood lead and cadmium levels were available and who answered the questionnaire were selected as the final participants. We investigated the drinking habit, smoking status, exercise adequacy, and family history of hypertension of these workers using formal questionnaires. A statistical analysis was conducted using Student's t-test, analysis of variance, and linear or logistic regression. RESULTS: The association between blood lead and cadmium levels and blood pressure was analyzed through statistical adjustment of the risk factors of hypertension. Results showed an association between blood cadmium level and blood pressure elevation. However, blood lead level was found to be not correlated with blood pressure elevation. CONCLUSIONS: This study shows the association between blood cadmium level and systolic blood pressure (SBP) and diastolic blood pressure (DBP) elevation. TRIAL REGISTRATION: IRB No. 2017–03-037. Retrospectively Registered 30 March 2017.
Blood Glucose ; Blood Pressure* ; Cadmium* ; Cross-Sectional Studies* ; Drinking ; Ethics Committees, Research ; Fasting ; Humans ; Hypertension ; Logistic Models ; Male ; Metals, Heavy ; Osmeriformes* ; Retrospective Studies ; Risk Factors ; Smoke ; Smoking ; Ulsan

Porphyromonas gingivalis (P. gingivalis) has a strong association with the pathogenesis of periodontal disease. Recurrence of periodontal disease following therapy is attributed to numerous factors, and of growing interest is the potential problem of intracellular bacteria that are able to persist and multiply within the host cell, thereby facilitating relapse of infection. The effect of antibiotic therapy in controlling P. gingivalis is questionable. Accordingly, while metronidazole is very effective against anaerobic extracellular P. gingivalis by disrupting the DNA of anaerobic microbial cells, this antibiotic does not effectively penetrate into mammalian cells to inhibit intracellular bacteria. Therefore in the present study, a modified porphyrin-linked metronidazole adducts, developed in our laboratory, was used to kill intracellular P. gingivalis. A series of experiments were performed, including cytotoxicity assays and cellular uptake of adducts by flow cytometry coupled with live cell imaging analysis, P. gingivalis invasion and elimination assays, and the analysis of colocalization of P. gingivalis and porphyrin-linked metronidazole by confocal laser scanning microscopy. Findings indicated that P. gingivalis and porphyrin-linked metronidazole were colocalized in the cytoplasm, and this compound was able to kill P. gingivalis intracellular with a sufficient culture time.This is a novel antimicrobial approach in the elimination of P. gingivalis from the oral cavity.