OBJECTIVE: This study investigated the driving habits of taxi drivers, in order to examine the characteristics of human factors causing traffic accidents and unsafe driving behavior and to determine any relevancy among them. METHOD: Taxi drivers (N=335) answered a questionnaire investigating various measures of human factors, unsafe driving behaviors, and number of traffic accident experiences in the previous year. In factor analysis, the characteristics of human factors were classified into 5 common factors: job, mental health, age, health habit and sleep factor. A contextual mediated model was proposed to distinguish the distal (5 common factors) and proximal (unsafe driving behaviors) factors in predicting traffic accident involvement by hierarchical multiple regression. RESULT: In hierarchical multiple regression, job factor(beta: 0.122), sleep factor (beta: 0.114) and unsafe driving behaviors (beta: 0.018) yielded a direct effect on the rate of traffic accidents. Mental health factor beta: 6.429), job factor (beta: 1.319) and health habit factor(beta: 1.177) yielded a indirect effect on the rate of traffic accidents by unsafe driving behaviors. CONCLUSION: Various human factors co-related by the unique characteristics that exist in the taxi service industry have significant effects on the rate of traffic accidents mediated by unsafe driving behaviors. Therefore a proper countermeasure against these factors should be established in order to effectively reduce the rate of taxi accidents.
Accidents, Traffic* ; Humans* ; Mental Health ; Questionnaires

The purpose of this study is to investigate the relationship between the self-reported musculoskeletal symptoms and related factors among VDT operators in bank. The subjects were 950 women workers. The characteristics of subjects were 26.6 years of average age, 5.7 years of average VDT use duration and 6.5 hours of daily VDT use time. The results were as follows. The prevalence of self-reported musculoskeletal symptoms more than severe in Likert scale were 51.4%, 43.9% at the shoulder, 38.3%, 31.8% at the lower back, 38.0%, 31.3% at the neck, 31.2%, 25.2% at the upper back, 21.7%, 16.5% at the wrist and 13.6%, 8.8% at the fingers (while on duty, after home-coming). General characteristic variables affecting the musculoskeletal symptoms were married, number of child and daily house-working time. Work-related factors affecting the musculoskeletal symptoms were VDT working career, daily working time, daily VDF use time, VDF use time without rest, daily work-load and regular rest. As the result of the multiple logistic regression analysis, daily working time, daily VDT use time and VDT working career were significant variables accounting for the musculoskeletal symptoms.
Child ; Cumulative Trauma Disorders ; Female ; Fingers ; Humans ; Logistic Models ; Neck ; Prevalence* ; Shoulder ; Wrist

PURPOSE: The effects of biological subtypes within breast cancer on prognosis are influenced by age at diagnosis. We investigated the association of young age with locoregional recurrence (LRR) between patients with luminal subtypes versus those with nonluminal subtypes. MATERIALS AND METHODS: Medical records of 524 breast cancer patients with positive lymph nodes between 1999 and 2010 were reviewed retrospectively. All patients received curative surgery and adjuvant chemotherapy based on contemporary guidelines. Radiation was delivered for patients who underwent breast conserving surgery or those who had four or more positive lymph nodes after mastectomy. Adjuvant hormone therapy was administered to 413 patients with positive hormone receptors according to their menstrual status. RESULTS: During median follow-up of 84 months, the 10-year locoregional recurrence-free survival rate (LRRFS) was 84.3% for all patients. Patients < 40 years showed significantly worse 10-year LRRFS than those ≥ 40 years (73.2% vs. 89.0%, respectively; p=0.01). The negative effect of young age on LRRFS was only observed in luminal subtypes (69.7% for < 40 years vs. 90.8% for ≥ 40 years; p < 0.01). Multivariate analysis using luminal subtypes ≥ 40 years as a reference revealed luminal subtypes < 40 years were significantly associated with increased risk of LRR (hazard ratio, 2.33; p < 0.01). CONCLUSION: Young breast cancer patients with positive lymph nodes had a higher risk of LRR than those aged ≥ 40 years. This detrimental effect of young age on LRR was confined in luminal subtypes.
Age Factors ; Breast Neoplasms* ; Breast* ; Chemotherapy, Adjuvant ; Diagnosis ; Follow-Up Studies ; Humans ; Lymph Nodes ; Mastectomy ; Mastectomy, Segmental ; Medical Records ; Multivariate Analysis ; Neoplasm Recurrence, Local ; Phenobarbital* ; Prognosis ; Recurrence* ; Retrospective Studies ; Survival Rate

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.
Epidemiologic Studies* ; Humans ; Korea* ; Radiation Exposure* ; Seoul*

OBJECTIVES: We aimed to assess the radiation exposure for epidemiologic investigation in residents exposed to radiation from roads that were accidentally found to be contaminated with radioactive cesium-137 (137Cs) in Seoul. METHODS: Using information regarding the frequency and duration of passing via the 137Cs contaminated roads or residing/working near the roads from the questionnaires that were obtained from 8875 residents and the measured radiation doses reported by the Nuclear Safety and Security Commission, we calculated the total cumulative dose of radiation exposure for each person. RESULTS: Sixty-three percent of the residents who responded to the questionnaire were considered as ever-exposed and 1% of them had a total cumulative dose of more than 10 mSv. The mean (minimum, maximum) duration of radiation exposure was 4.75 years (0.08, 11.98) and the geometric mean (minimum, maximum) of the total cumulative dose was 0.049 mSv (<0.001, 35.35) in the exposed. CONCLUSIONS: An individual exposure assessment was performed for an epidemiological study to estimate the health risk among residents living in the vicinity of 137Cs contaminated roads. The average exposure dose in the exposed people was less than 5% of the current guideline.
Epidemiologic Studies* ; Humans ; Korea* ; Radiation Exposure* ; Seoul*

OBJECTIVES: To investigate the chronological subjective symptoms and related factors in ex-workers who were occupationally exposed to Carbon disulfide. METHODS: One hundred and seventy-seven subjects (147 males and 30 females) were randomly selected among ex-workers and interviewed by well trained doctors, who filled out a structured questionnaire developed by authors on the subjective symptoms. The questionnaire was composed of symptoms in the head and neck, and those of the neuro-psychological, respiratory, endocrine, musculoskeletal, and reproductive systems. Other factors such as general and occupational characteristics including work department, work duration, duration since cessation of exposure, and compensation for occupational disease were also investigated. RESULTS: The mean subject age was 55.4 years. The mean cumulative exposure index (CEI) was 38.96 +/- 31.18. CEI was significantly higher in the compensated group (47.61 +/- 32.51) than in the non-compensated group (26.81 +/- 24.75)(p=0.000). Symptom complaints were significantly higher in the compensated group in all organ systems, and their incidence increased gradually until 10 years after cessation of work, and then decreased. The mean duration for cessation of exposure at the time of compensation was 10.97 years. The significantly different factors between the compensated group and the non-compensated group were total cumulative exposure index and the time interval between the cessation of work and the time of compensation. CONCLUSION: Our findings suggest that total cumulative exposure index and the time interval between the cessation of work and the time of compensation may be important factors affecting the compensation for occupational disease. Therefore, further studies will be necessary.
Carbon Disulfide* ; Carbon* ; Compensation and Redress* ; Head ; Humans ; Incidence ; Male ; Neck ; Occupational Diseases ; Occupations* ; Poisoning* ; Questionnaires

Halophytes are expected to possess abundant secondary metabolites and various biological activities because of habitat in extreme environments. In this study, we collected 14 halophytes (Asparagus oligoclonos, Calystegia soldanella, Carex pumila, Chenopodium glaucum, Elymus mollis, Glehnia littoralis, Limonium tetragonum, Messerschmidia sibirica, Rosa rugosa, Salsola komarovii, Spergularia marina, Suaeda glauca, Suaeda maritima, and Vitex rotundifolia) native to Korea and compared their total polyphenol contents, antioxidant and anti-inflammatory activities. The total polyphenol contents of R. rugosa (27.28%) and L. tetragonum (13.17%) were significantly higher than those of the other 12 halophytes and L. tetragonum, R. rugosa, and M. sibirica showed significantly greater antioxidant activities than the other 11 halophytes, as determined by DPPH (2,2-diphenyl-1-picrylhydrazyl). A. oligoclonos, E. mollis, and C. pumila showed significantly greater anti-inflammatory activities than the other 11, as determined by NO (Nitric oxide) and PGE₂ (Prostaglandin E₂) levels. In contrast, these three extracts had normal and low total polyphenol contents among the 14 halophytes. Consequently, the total polyphenol content in the 14 studied halophytes appeared to be related to antioxidant, but not anti-inflammatory activity levels.
Apiaceae ; Calystegia ; Caryophyllaceae ; Chenopodiaceae ; Chenopodium ; Ecosystem ; Elymus ; Korea ; Plumbaginaceae ; Rosa ; Salsola ; Salt-Tolerant Plants ; Vitex

PURPOSE: This study aimed to evaluate the effects of i) the extent of peri-implant bone defects and ii) the application of bone cement on implant stability with respect to the measurement direction. METHODS: In 10 bovine rib bones, 4 implant osteotomies with peri-implant bone defects of various widths were prepared: i) no defect (D0), ii) a 2-mm-wide defect (D2), iii) a 4-mm-wide defect (D4), and iv) a 8-mm-wide defect (D8). The height of all defects was 10 mm. Implant stability quotient (ISQ) values and Periotest values (PTVs) were measured after implant placement and bone cement application. RESULTS: With increasing defect width, decreased ISQs and increased PTVs were observed. Statistically significant differences were found between groups D0 and D8, D0 and D4, and D2 and D8. Prior to bone cement application, inconsistent PTVs were found in group D8 depending on the measurement direction. Bone cement increased the implant stability. CONCLUSION: Peri-implant bone deficits measuring around 50% of the implant surface compromised implant stability. Clinically, PTVs should be cautiously interpreted in implants with large peri-implant defects due to inconsistent recordings with respect to the measurement direction.
Alveolar Bone Loss ; Bone Transplantation ; Dental Implants ; In Vitro Techniques ; Models, Anatomic ; Osteotomy ; Ribs

BACKGROUND/AIMS: Many patients are diagnosed with cryptogenic hepatocellular carcinoma (HCC) without metabolic syndrome (MS). We investigated the risk factors for cryptogenic HCC in patients with a low body mass index (BMI) or without MS. METHODS: Thirty-six patients were diagnosed with cryptogenic HCC over a 10-year period at a tertiary research hospital. Data including BMI score and risk factors for MS were analyzed retrospectively. Patients with fewer than two risk factors for MS (n = 16) were compared with those with two or more risk factors (n = 20). Patients with high BMI (> or = 23 kg/m2, n = 20) were also compared with those with lower BMI (n = 16). RESULTS: Patients with fewer than two risk factors for MS were significantly more likely to smoke and be hepatitis B surface antibodies (anti-HBs)-positive vs. patients with two or more risk factors. However, only smoking was statistically significant on multivariate analysis. Peaks of BMI were observed in two regions. Lower BMI was significantly associated with the presence of anti-HBs compared with high BMI, although this association was not statistically significant on multivariate analysis. CONCLUSIONS: Smoking is a potential risk factor for cryptogenic HCC in patients without MS. Remote hepatitis B virus infection may be a risk factor for cryptogenic HCC in patients without MS or with a low BMI.
Aged ; Aged, 80 and over ; *Body Mass Index ; Carcinoma, Hepatocellular/*epidemiology ; Chi-Square Distribution ; Female ; Hepatitis B/diagnosis/epidemiology ; Hepatitis B Antibodies/blood ; Hepatitis B Surface Antigens/immunology ; Humans ; Liver Neoplasms/*epidemiology ; Logistic Models ; Male ; Metabolic Syndrome X/*epidemiology ; Middle Aged ; Multivariate Analysis ; Odds Ratio ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Smoking/adverse effects/epidemiology ; Time Factors