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.

PURPOSE: Endometriosis is defined as functioning endometrial tissue outside of the uterus. Endometriosis of the appendix is uncommon. Its clinical presentation varies from asymptomatic to acute abdominal pain. The aims of this study were to describe our experience of managing patients with appendiceal endometriosis and to review the clinical characteristics of this medical condition. METHODS: Five cases of appendiceal endometriosis diagnosed between January 2007 and December 2012 were retrospectively reviewed. Patients treated for intra-abdominal endometriosis were excluded. RESULTS: The mean age at diagnosis was 33.8 years old. One patient was in the second trimester of pregnancy. Two patients were asymptomatic. Three patients had clinical symptoms including two with acute pain in the right lower quadrant and one with abdominal discomfort. Four patients showed appendiceal abnormalities in imaging studies including two cases of suspected mucocele and two cases of appendiceal infection. There were no suspicions of endometriosis of the appendix based on preoperative imaging studies. Three patients underwent appendectomy due to clinical symptoms, and two underwent incidental appendectomy combined with another operation. None of the patients received adjuvant therapy. CONCLUSION: Appendiceal endometriosis should be included in the differential diagnosis for acute abdominal pain, especially when women of childbearing age present with clinical symptoms of acute appendicitis.
Abdomen, Acute ; Abdominal Pain ; Acute Pain ; Appendectomy ; Appendicitis ; Appendix* ; Diagnosis ; Diagnosis, Differential ; Endometriosis* ; Female ; Humans ; Mucocele ; Pregnancy ; Pregnancy Trimester, Second ; Retrospective Studies ; Uterus

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.

PURPOSE: To determine the impact of noise on heart rate variability (HRV) in men, with a focus on the noise type rather than on noise intensity. MATERIALS AND METHODS: Forty college-going male volunteers were enrolled in this study and were randomly divided into four groups according to the type of noise they were exposed to: background, traffic, speech, or mixed (traffic and speech) noise. All groups except the background group (35 dB) were exposed to 45 dB sound pressure levels. We collected data on age, smoking status, alcohol consumption, and disease status from responses to self-reported questionnaires and medical examinations. We also measured HRV parameters and blood pressure levels before and after exposure to noise. The HRV parameters were evaluated while patients remained seated for 5 minutes, and frequency and time domain analyses were then performed. RESULTS: After noise exposure, only the speech noise group showed a reduced low frequency (LF) value, reflecting the activity of both the sympathetic and parasympathetic nervous systems. The low-to-high frequency (LF/HF) ratio, which reflected the activity of the autonomic nervous system (ANS), became more stable, decreasing from 5.21 to 1.37; however, this change was not statistically significant. CONCLUSION: These results indicate that 45 dB(A) of noise, 10 dB(A) higher than background noise, affects the ANS. Additionally, the impact on HRV activity might differ according to the noise quality. Further studies will be required to ascertain the role of noise type.
Adaptation, Psychological ; Confounding Factors (Epidemiology) ; Environment ; Heart Rate/*physiology ; Humans ; Male ; *Noise ; Questionnaires ; Stress, Psychological/physiopathology ; Young Adult

OBJECTIVES: To investigate the effects of smoking on hearing loss among workers exposed to occupational noise. METHODS: From the results of a special workers health examination performed in 2011, we enrolled 8,543 subjects exposed to occupational noise and reviewed the findings. Using self-reported questionnaires and health examination results, we collected data on age, smoking status, disease status, height, weight, and biochemistry and pure tone audiometry findings. We divided the workers into 3 groups according to smoking status (non-smoker, ex-smoker, current smoker). Current smokers (n = 3,593) were divided into 4 groups according to smoking amount (0.05-9.9, 10-19.9, 20-29.9, > or =30 pack-years). We analyzed the data to compare hearing thresholds between smoking statuses using analysis of covariance (ANCOVA) after controlling for confounder effects. RESULTS: According to ANCOVA, the hearing thresholds of current smokers at 2 k, 3 k, and 4 kHz were significantly higher than that of the other groups. Multiple logistic regression for smoking status (reference: non-smokers) showed that the adjusted odds ratios of current smokers were 1.291 (95% confidence interval [CI]: 1.055-1.580), 1.180 (95% CI: 1.007-1.383), 1.295 (95% CI: 1.125-1.491), and 1.321 (95% CI: 1.157-1.507) at 1 k, 2 k, 3 k, and 4 kHz, respectively. Based on smoking amount, the adjusted odds ratios were 1.562 (95% CI: 1.013-2.408) and 1.643 (95% CI: 1.023-2.640) for the 10-19.9 and > or =30 pack-years group, respectively, at 1 kHz (reference: 0.05-9.9 pack-years). At 2 kHz, the adjusted odds ratios were increased statistically significantly with smoking amount for all groups. At all frequencies tested, the hearing thresholds of noise-exposed workers were significantly influenced by current smoking, in particular, the increase of hearing loss at low frequencies according to smoking amount was more prevalent. CONCLUSIONS: Current smoking significantly influenced hearing loss at all frequencies in workers exposed to occupational noise, and heavier smoking influenced low-frequency hearing loss more greatly. There was a dose-response relationship between smoking amount and low-frequency hearing thresholds; however, this was not observed for high-frequency hearing thresholds. Therefore, well-designed prospective studies are needed to clarify the effects of smoking on the degree of hearing loss.
Audiometry ; Biochemistry ; Hearing Loss* ; Hearing* ; Logistic Models ; Noise, Occupational* ; Odds Ratio ; Smoke ; Smoking* ; Tobacco Products* ; Surveys and Questionnaires

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

Segmental C1-2 screw fixation using C1 lateral mass screws and C2 pedicle screws is a technically demanding procedure which can cause injuries to the vertebral artery or neural structures as well as massive bleeding from the epidural venous plexus. In particular, this procedure is more difficult in revision cases because of the lack of normal anatomical landmarks, adhesion, and bleeding. The authors report a case of a patient in whom preoperative surgical simulation and planning using computer software was very helpful in the direct screwing of the atlas and axis for a revision of atlantoaxial fusion.
Axis, Cervical Vertebra ; Computer Simulation* ; Hemorrhage ; Humans ; Vertebral Artery

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*

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: 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.