Comparison of risk-assessment tools for cardio-cerebrovascular diseases (CVD) in male shipyard workers: a cross-sectional study

BACKGROUND: Periodic revision of assessment tools is essential to ensure risk assessment reliability and validity. Despite the recent revision of the Korea Occupational Safety and Health Agency (KOSHA) 2018, there is no evidence showing that the revision is superior to other cardio-cerebrovascular diseases (CVDs) risk-assessment tools for workplace health management. We conducted a comparative analysis using the Framingham risk score (FRS) as a gold standard to identify the most relevant CVDs risk-assessment tool for workplace health management. METHODS: We included 4,460 shipyard workers who had undergone a workers' health examination during January–December 2016. Risk levels for CVDs were calculated based on the FRS, KOSHA 2013, KOSHA 2017, KOSHA 2018 (2 methods), National Health Screening Program health risk appraisal (NHS HRA) 2017, and NHS HRA 2018. Study participants were categorized into low-risk, moderate-risk, or high-risk groups. Sensitivity, specificity, correlation, and agreement of each risk-assessment tool were calculated compared with the FRS as a gold standard. For statistical analyses, Spearman's rank correlation coefficient and the linearly weighted kappa coefficient were calculated. RESULTS: Sensitivity of the risk assessments was highest in the KOSHA 2018 (health risk appraisal [HRA]). The FRS showed correlation coefficients of 0.354 with the KOSHA 2013, 0.396 with the KOSHA 2017, 0.386 with the KOSHA 2018, 0.505 with the KOSHA 2018 (HRA), 0.288 with the NHS HRA 2017, and 0.622 with the NHS HRA 2018. Kappa values, calculated to examine the agreement in relation to the KOSHA 2013, KOSHA 2017, KOSHA 2018, KOSHA 2018 (HRA), NHS HRA 2017, and NHS HRA 2018 with the FRS, were 0.268, 0.322, 0.352, 0.136, 0.221, and 0.559, respectively. CONCLUSIONS: The NHS HRA 2018 risk calculation method is a useful risk-assessment tool for CVDs, but only when appropriate classification criteria are applied. In order to enhance the risk-group identification capability of the KOSHA guideline, we propose to apply the classification criteria set in this study based on the risk group definition of the 2018 Korean Society of Hypertension guidelines for the management of hypertension instead of the current classification criteria of the KOSHA 2018.

The effect of shift work on high sensitivity C-reactive protein level among female workers

BACKGROUND: This study assessed the association between shift work and high-sensitivity C-reactive protein (hs-CRP) level, a risk factor for cardiovascular disease (CVD), in female workers in electronics manufacturing services (EMS). METHODS: Female EMS workers who received special medical examinations for workers in Gyeongnam, Korea between January 2017 and December 2017 were enrolled in this study. Their age, marital status, education level, alcohol consumption, smoking habit, regular exercise, quality of sleep, work stress, and depression were investigated, and blood tests were conducted. The t- and χ2 tests were conducted to compare the general and biochemical characteristics between daytime and shift worker groups. Age-adjusted partial correlation analysis was performed to examine the linear relationship between hs-CRP level and other risk factors for CVDs. In addition, the difference in hs-CRP levels according to work schedule was analyzed by ANCOVA after adjusting for variables that could affect the hs-CRP level. RESULTS: Although the average hs-CRP levels did not differ significantly between daytime and shift workers (0.92 ± 1.87 and 1.07 ± 2.20 mg/dL, respectively), shift workers tended to show a higher hs-CRP level (p = 0.067). After adjusting for variables that can affect the hs-CRP level, the estimated average hs-CRP level was significantly higher in shift workers (1.325 ± 0.156 mg/dL) than that in daytime workers (0.652 ± 0.350 mg/dL) (p = 0.003). CONCLUSIONS: The results of this study identified a relationship between shift work and hs-CRP level increase in women. Because multiple studies have reported associations between increased hs-CRP and CVD, follow-up of hs-CRP may help early detection of CVD in shift workers.

Considerations for patient selection: Prepectoral versus subpectoral implant-based breast reconstruction

BACKGROUND@#In recent years, breast implants have been frequently placed in the subcutaneous pocket, in the so-called prepectoral approach. We report our technique of prepectoral implant-based breast reconstruction (IBR), as well as its surgical and aesthetic outcomes, in comparison with subpectoral IBR. We also discuss relevant considerations and pitfalls in prepectoral IBR and suggest an algorithm for the selection of patients for IBR based on our experiences.@*METHODS@#We performed 79 immediate breast reconstructions with a breast implant and an acellular dermal matrix (ADM) sling, of which 47 were subpectoral IBRs and 32 were prepectoral IBRs. Two-stage IBR was performed in 36 cases (20 subpectoral, 16 prepectoral), and direct-to-implant IBR in 43 cases (27 prepectoral, 16 subpectoral). The ADM sling supplemented the inferolateral side of the breast prosthesis in the subpectoral group and covered the entire anterior surface of the breast prosthesis in the prepectoral group.@*RESULTS@#The postoperative pain score was much lower in the prepectoral group than in the subpectoral group (1.78 vs. 7.17). The incidence of seroma was higher in the prepectoral group (31.3% vs. 6.4%). Other postoperative complications, such as surgical site infection, flap necrosis, implant failure, and wound dehiscence, occurred at similar rates in both groups. Animation deformities developed in 8.5% of patients in the subpectoral group and rippling deformities were more common in the prepectoral group (21.9% vs. 12.8%).@*CONCLUSIONS@#The indications for prepectoral IBR include moderately-sized breasts with a thick well-vascularized mastectomy flap and concomitant bilateral breast reconstruction with prophylactic mastectomy.

Bilateral cleft lip repair with simultaneous premaxillary setback and primary limited rhinoplasty / 대한악안면성형재건외과학회지

BACKGROUND: Functional closure of the orbicularis oris muscle and esthetic reconstruction of nasolabial components are impossible in patients with severely deformed premaxilla. Here, we review a surgical strategy for patients with unremedied premaxilla retrospectively. RESULTS: Vomerine ostectomy and premaxillary setback with nasolabial repair were performed in 12 patients with bilateral cleft lip and palate. The mean age of patients was 21.7 months. The extent of ostectomy varied between 3 and 11 mm. There were no serious complications from defective perfusion to the premaxilla or the philtral flap. The follow-up period ranged from 2 to 25 months. Proper positioning of the premaxilla and satisfactory nasolabial esthetics were achieved in all patients. CONCLUSIONS: We performed nasolabial repair after premaxillary setback without jeopardizing the premaxillary segment or the philtral flap. Our surgical strategy could be recommended in poor socio-economic circumstances due to the cost effectiveness of limiting the number of surgeries.

Changes of depression and job stress in workers after merger without downsizing

BACKGROUND: Since the 1980s, restructuring, which includes downsizing, closures, mergers, and privatization, has expanded worldwide, and various studies have investigated its effect on health. However, previous studies have mainly focused on restructuring accompanied by massive lay-offs, and the effect of a merger on workers’ health is still controversial. This study aims to investigate changes in worker depression and job stress after a merger without downsizing, which is unusual in Korea. METHODS: Repeated surveys were done in April 2014, April 2015, and April 2016 involving the participation of 209 subjects. Participants were divided into two groups, which were comprised of blue-collar workers (104) and white-collar workers (105). Sociodemographic characteristics, including age, education level, job tenure, gender, marital status, smoking status, and alcohol consumption, were measured via a survey. To determine the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was employed, and to investigate job stress, the Korean Occupational Stress Scale-Short Form (KOSS-SF) was used. For statistical analyses, Pearson’s chi-square test, the Student’s t-test, and repeated measure analysis of variance (ANOVA) were performed. RESULTS: The results showed that depression (CES-D, F[2, 400] = 0.466, p = 0.628) was changed but without significance and job stress (KOSS-SF, F[1.899, 379.831] = 3.192, p = 0.045) were significantly different. The between-group difference in the CES-D score between the blue- and white-collar workers by survey administration time was not statistically significant (F = 0.316, p = 0.574). The interaction between the survey time and occupational group was also not statistically significant (F = 0.967, p = 0.381). The between-group difference in the KOSS-SF total score was not statistically significant (F = 1.132, p = 0.289), and the interaction between the survey administration time and occupational group was also not significant (F = 0.817, p = 0.437). In the job stress subgroup analyses Job insecurity and Lack of reward showed a significant difference by survey administration time. CONCLUSION: This study showed that a merger without massive downsizing can cause negative health effects such as an changes in depression and increase in job stress. To improve the health of workers, both the immediate negative effects on health, and the long-term effects or their resolution over time should be considered prior to the merger.

The relationship between serum vitamin D levels and sleep quality in fixed day indoor field workers in the electronics manufacturing industry in Korea

BACKGROUND: Although recent studies have investigated the influence of vitamin D on sleep patterns, there is a lack of research on the relationship between vitamin D and sleep patterns in Korean workers. This study focused on the relationship between serum vitamin D levels and sleep in fixed day indoor field workers in the electronics manufacturing industry in Korea. METHODS: The 1472 subjects who were included in this study were selected from fixed day workers in the electronics manufacturing industry who had received a worker’s special health examination at a hospital in Changwon, South Gyeongsang Province between January 2015 and December 2015. Nighttime workers and those who showed symptoms of depression were excluded from this study. The sociodemographic and lifestyle variables of the participants were investigated, including age, sex, marital status, level of education, body mass index, smoking habits, alcohol consumption habits, and regular exercise. Work-related factors were evaluated, such as employee tenure and occupational stress. Serum 25-hydroxyvitamin D was measured as an indicator of vitamin D levels, and quality of sleep was evaluated using the Pittsburgh Sleep Quality Index (PSQI) translated into Korean. RESULTS: The subjects had a mean serum vitamin D level of 13.70 ± 5.93 ng/mL. Vitamin D deficiency, defined as a serum vitamin D level of <10 ng/mL, was found in 24.8% of males and significantly more frequently in females (47.6%). Poor sleep quality was reported by 19.8% of participants with serum vitamin D levels ≥10 ng/mL and by 21.7% of those with serum vitamin D levels <10 ng/mL, which was a significant difference (P = .007). Multiple logistic regression analysis adjusting for significant variables found that poor sleep quality was more likely in those with vitamin D deficiency than those with higher serum vitamin D levels (odds ratio = 1.36; 95% CI, 1.01–1.82). A comparison of serum vitamin D levels and PSQI components showed that the mean scores for subjective sleep quality, sleep latency, and sleep duration were significantly higher in the vitamin D-deficient participants, indicating that the vitamin D-deficient participants had poorer sleep quality. CONCLUSIONS: This study investigated serum vitamin D levels in fixed day indoor field workers in the manufacturing industry in Korea and analyzed the relationship of vitamin D deficiency with sleep quality. A significant correlation was found between serum vitamin D deficiency and poor sleep quality. Based on the results of this study, sleep disorder management for workers can be improved by providing regular examinations checking their serum vitamin D levels and supplying vitamin D to workers with serum vitamin D deficiency to enhance their quality of sleep.

Bone Scintigraphy in the Diagnosis of Rheumatoid Arthritis: Is There Additional Value of Bone Scintigraphy with Blood Pool Phase over Conventional Bone Scintigraphy?

We aimed to investigate the value of bone scintigraphy with additional blood pool phase (BSBP), compared with conventional bone scintigraphy (CBS), in the assessment of rheumatoid arthritis (RA). A total of 242 patients (43 males, 199 females; 14-78 years) with arthralgia, and underwent BSBP were retrospectively analyzed. On the first physical examination, active arthritis was found in 128 of the 242 patients. Clinical diagnosis was made by a rheumatologist on the basis of the 1987 American College of Rheumatology (ACR) criteria, which are considered to be the gold standard. The diagnostic performances and prognostic value of BSBP and CBS were analyzed in the total patients with arthralgia and in the patients with arthritis. The sensitivity of BSBP (84.2%, 80/95) were significantly higher than that of CBS (74.8%, 72/95) in the patients with arthralgia (P = 0.039). When BSBP was interpreted with the results of elevated/positive anti-CCP antibody, its accuracy over CBS also became significantly higher (86.0%, 208/242 vs. 83.1%, 201/242 respectively, P = 0.021). The diagnostic odds ratio of BSBP positivity was higher than CBS positivity in the patients with arthralgia (26.0, 12.9-52.4 vs. 21.1, 10.8-41.3) and with arthritis (12.0, 4.9-29.4 vs. 10.0, 4.2-23.4). Both BSBP and CBS appear to provide acceptable accuracy and comparable diagnostic performance for diagnosis of RA. However, in the patients with arthralgia, BSBP was found to be more sensitive than CBS and more accurate when interpreted with the result of anti-CCP antibody. This could help physicians diagnose RA in daily clinical practice.

Erratum to: The relationship between quality of sleep and night shift rotation interval

There was an error in one of the author names in this article. The publisher apologises for any inconvenience caused.

Evaluation of Propidium Monoazide Real-Time PCR for Viablity of Mycobacterium leprae / 나학회지

BACKGROUND: Conventional acid-fast bacilli (AFB) staining cannot differentiate viable from dead cells. Propidium monoazide (PMA) is a photoreactive DNA-binding dye that inhibits PCR amplification by DNA modification. OBJECT: The author evaluated whether PMA real-time PCR is suitable for the viablity of Mycobacterium leprae (M. leprae) in specimens of cultivation in mouse foot pads. METHODS: A total of 55 diluted suspensions from mouse foot pads were quadruplicated and subjected to PMA treatment and/or heat inactivation, and were also tested to compare the ΔCT values (CT value in PMA-treated samples-CT value in non-PMA-treated samples). Real-time PCR was performed using QuantiTect SYBR® Green PCR Kits(Qiagen, USA), and the CT value changes after PMA treatment were compared between PMA treatment and/or heat inactivation groups. RESULTS: The increase in the CT value after PMA treatment was significant in heat inactivated group(4.26) and non-heat inactivated group(1.12)(both P = 0.000). In the ROC curve analysis, the cutoff ΔCT value for maximum sensitivity (100%) and specificity (97.1%) for differentiating dead from live cells was 2.41 CONCLUSIONS: PMA real-time PCR is a useful approach for evaluating viablity of M. leprae.

Anxiety symptoms and occupational stress among young Korean female manufacturing workers

BACKGROUND: The prevalence of anxiety disorders has been increasing in South Korea, with recent studies reporting anxiety disorders as the most common mental disorder among all South Korean females. Anxiety disorders, which are independent risk factors of suicidal ideation and suicide attempts, are significantly correlated with productivity loss, high medical costs, impaired work performance, and frequent worker absence, and thus are potentially serious problems affecting the health of South Korean female workers. In previous studies, anxiety disorders were shown to have a significant correlation with occupational stress. This study seeks to examine the prevalence of anxiety symptoms as well as the relationship between occupational stress and anxiety symptoms among South Korean female manufacturing workers. METHODS: A structured self-reported questionnaire was administered to 1,141 female workers at an electrical appliance manufacturing plant. The questionnaire collected data on general characteristics, health behaviors, sleep quality, job characteristics (shift work, shift work schedule, and job tenure), occupational stress, and anxiety symptoms. Sleep quality was measured using the Pittsburgh Sleep Quality Index, occupational stress with the Korean Occupational Stress Scale-Short Form (KOSS-SF), and anxiety symptoms with the Korean version of the Beck Anxiety Inventory. A chi square test was conducted to determine the distribution differences in anxiety symptoms based on general characteristics, health behaviors, job characteristics, and sleep quality. A linear-by-linear association test was used to determine the distribution differences between anxietysymptoms and the levels of occupational stress. Last, logistic regression analysis was used in order to determine the association between occupational stress and anxiety symptoms. RESULTS: The prevalence of anxiety symptoms was 15.2 %. In the multivariate logistic regression analysis that adjusted for sleep quality and general characteristics, a significantassociation was found for those with anxiety disorders; the odds ratios (OR) were significantly higher the greater the total KOSS-SF score (moderate-risk group OR=2.85, 95 % CI=1.79-4.56; high-risk group OR=5.34, 95 % CI=3.59-7.96). In addition, excluding insufficient job control, all other KOSS-SF subscales were significantly associated with anxiety symptoms, and a relatively high OR was seen in the high-risk group for job demand (OR=3.19, 95 % CI=2.27-4.49), job insecurity (OR=4.52, 95 % CI=2.86-7.13), and occupational culture (OR=4.52, 95 % CI=2.90-7.04). CONCLUSION: There was a significant association between anxiety symptoms and occupational stress stemming from the psychosocial work environment among these South Korean female manufacturing workers. Future longitudinal studies are needed to examine the association between the occupational stress caused by the psychosocial work environment and the incidence of anxiety disorders and anxiety symptoms. Furthermore, intervention programs that aim to address the prevalence of anxiety symptoms and improve the psychosocial work environment, especially for younger female manufacturing workers, are needed.

Association between serum vitamin D and depressive symptoms among female workers in the manufacturing industry

BACKGROUND: Vitamin D has been known to maintain the body's balance of calcium and phosphorus as well as skeletal health. There has been increasing emphasis on the importance of vitamin D as recent studies have been reporting the specific functions of vitamin D in the cerebral nervous system and the association between the level of serum vitamin D and depressive symptoms. However, there is currently a paucity of research investigating the association between serum vitamin D and depressive symptoms in Korean subjects. Consequently, this study has aimed to determine the level of serum vitamin D and explore the association between serum vitamin D and depressive symptoms in Korean female workers. METHOD: A medical examination, questionnaire, anthropometric measurements, and a blood test were conducted between February 3 and March 7, 2014 in 1054 subjects among female workers in the manufacturing industry who underwent physical examinations in a university hospital. From this data, we identified the level of serum vitamin D and investigated the association between serum vitamin D deficiency and depressive symptoms. RESULTS: The average serum vitamin D level of the 1054 subjects was 9.07 +/- 3.25 ng/mL, and the number of subjects in the serum vitamin D deficiency group with less than 10 ng/mL was 721 (68.4 %). The odds ratio of the depressive symptom group with a CES-D score of 16 or above being in the deficiency group with a serum vitamin D level less than 10 ng/mL was found to be 1.55 (95 % CI = 1.15-2.07). CONCLUSION: 68.4 % of female workers in the manufacturing industry were in the deficiency group with serum vitamin D levels less than 10 ng/mL. Additionally, we identified an association between serum vitamin D deficiency and depressive symptoms. In the future, if serum vitamin D deficiency is checked regularly in workers, we expect to achieve better outcomes in managing their depressive symptoms.

The relationship between quality of sleep and night shift rotation interval

BACKGROUND: Shift work is closely related with workers' health. In particular, sleep is thought to be affected by shift work. In addition, shift work has been reported to be associated with the type or direction of shift rotation, number of consecutive night shifts, and number of off-duty days. We aimed to analyze the association between the night shift rotation interval and the quality of sleep reported by Korean female shift workers. METHODS: In total, 2,818 female shift workers from the manufacturing industry who received an employee physical examination at a single university hospital from January to August in 2014 were included. Subjects were classified into three groups (A, B, and C) by their night shift rotation interval. The quality of sleep was measured using the Korean version of the Pittsburgh Sleep Quality Index (PSQI). Descriptive analysis, univariate logistic regression, and multivariate logistic regression were performed. RESULTS: With group A as the reference, the odds ratio (OR) for having a seriously low quality of sleep was 1.456 (95% CI 1.171-1.811) and 2.348 (95% CI 1.852-2.977) for groups B and C, respectively. Thus, group C with the shortest night shift rotation interval was most likely to have a low quality of sleep. After adjustment for age, obesity, smoking status, alcohol consumption, exercise, being allowed to sleep during night shifts, work experience, and shift work experience, groups B and C had ORs of 1.419 (95% CI 1.134-1.777) and 2.238 (95% CI 1.737-2.882), respectively, compared to group A. CONCLUSION: Our data suggest that a shorter night shift rotation interval does not provide enough recovery time to adjust the circadian rhythm, resulting in a low quality of sleep. Because shift work is influenced by many different factors, future studies should aim to determine the most optimal shift work model and collect accurate, prospective data.

Anti-tumor Effects of Vascular Endothelial Growth Factor Receptor-3 Inhibitor on Oral Cancer Cells

Sex Differences in Lifestyle Factors of Metabolic Syndrome in Korean Adults

BACKGROUND: Metabolic syndrome is a major risk factor for cardiovascular disease. The combination of an aging population with a chronic diseased population is leading to an increase in the mortality rate due to cardiovascular diseases. The purpose of this study was to assess the prevalence of metabolic syndrome in the Korean population and to evaluate its related factors for sex differences. METHODS: From April 2007 to December 2008, a total of 2,729 volunteers aged 40-69 years living in Changwon city underwent a clinical examination at a hospital in Changwon, Korea. Metabolic syndrome was diagnosed following the criteria defined in Circulation 2009. The clinical examination included measuring anthropometric variables and cardiovascular risk factors, while lifestyle factors were assessed through a questionnaire. RESULTS: The prevalence of metabolic syndrome in our sampling pool was 25.2% with a break down by sex showing a rate of 30.2% in men and 22.2% in women. Related factors associated with metabolic syndrome common to both sex were age, self-health assessment, and alcohol consumption. Sleep duration seemed to be a related factor in men, while income, education, and menstruation status played significant roles in women. CONCLUSIONS: To better manage metabolic syndrome, men need to be educated on alcohol use and women of low socioeconomic status require particular attention as do the aging population and postmenopausal women.

A Case of Rheumatoid Arthritis with Unilateral Knee Synovial Hypertrophy in Hemiplegia

A 64-year-old woman suffering right hemiplegia came in with pain and swelling on her left knee, general weakness and poor oral intake for 2 months. On physical examination we were able to palpate a mass with irregular margin around the left suprapatellar area. From the results of the magnetic resonance imaging (MRI), synovial proliferative disease, infectious arthritis, or gouty arthritis was suspected. We performed a blood laboratory test to detect rheumatologic diseases, knee joint aspiration, and bone scan for differential diagnosis, and were able to diagnose rheumatoid arthritis (RA) from the results of blood laboratory, physical examination, and bone scan. Consequently, we started medications for controlling RA. Herein, we report a case of rheumatoid arthritis with unilateral knee synovial hypertrophy in hemiplegia. If a right hemiplegic patient has recurrent pain on the left knee and synovial hypertrophy, and fails to respond to treatment for osteoarthritis, early detection by evaluation for rheumatic disease is crucial to prevent severe sequelae influencing rehabilitation of hemiplegia.

Basal cell adenoma misdiagnosed as an adenoid cystic carcinoma in the parotid gland

Basal cell adenoma (BCA) of the parotid gland is a rare benign tumor. In the parotid gland, BCA is occasionally difficult distinguish from adenoid cystic carcinoma in terms of clinical and pathological perspectives. An adenoid cystic carcinoma of the parotid gland grows slowly but spreads persistently to the surrounding tissues, particularly along the perineural spaces. In the present case, BCA of the parotid gland was misdiagnosed as an adenoid cystic carcinoma. We discuss the reason for such a misdiagnosis, and present a method for making a correct diagnosis.

The Relationship of Serum Vitamin D Levels and the Framingham Risk Score among Male Workers in the Manufacturing Sector / 대한산업의학회지

OBJECTIVES: A growing body of evidence states that vitamin D deficiencies may adversely affect cardiovascular disease, however data from Korean workers are lacking. The purpose of this study was to investigate the vitamin D level of the Korean worker and the relationship between vitamin D levels and the Framingham Risk Score. METHODS: 11,448 male workers who visited a university hospital for health screening between March 2010 and August 2011, were enrolled in the study. We measured their of serum vitamin D(25(OH)D) levels and calculated their Framingham Risk Score. RESULTS: The mean serum vitamin D(25(OH)D) level of the surveyed workers was 13.03+/-6.47 ng/mL. 12.4% of the total workers had adequate vitamin D levels. It was found that the lower the vitamin D level, the higher the risk of cardiovascular disease. The Framingham Risk Score and vitamin D levels were found to be significantly related (OR=1.39, 95% CI 1.14~1.68) through a multivariate logistic regression analysis. CONCLUSIONS: 87.6% of workers possessed inappropriate vitamin D levels. Management for this high risk group in regards to cardiovascular disease should be included in the evaluation and vitamin D levels should be corrected.

The Relationship between Fish Consumption and Blood Mercury Levels in Residents of Busan Metropolitan City and Gyeongnam Province / 農村醫學 地域保健

OBJECTIVES: The objective of this study was to identify the relationship between fish consumption and blood mercury levels in a sample of adult Koreans. METHODS: The study subjects were 299 residents of Busan (male: 65, female: 234) and 185 residents of Namhae (male: 69, female: 116), South Korea. Demographic characteristics, current smoking, current drinking, fish consumption per week, past history of amalgam treatment, and residential district were recorded by trained interviewers in June and July, 2009. We considered a portion of fish to be equivalent to 70 gm weight, and calculated amounts of fish consumed per week. Using chi-square tests, t-tests, ANOVA, and multiple linear regression analysis, we estimated the relationships between blood mercury levels and amount of fish consumed per week and other factors. RESULTS: The mean blood mercury level of our subjects was 6.61 microgram/L, higher than the criterion defined by the United States Environmental Protection Agency (EPA) (5.8 microgram/L). In multiple linear regression analysis, residential district and amount of fish consumed per week were associated with blood mercury levels. However, marital status, current drinking, and gender, and age were not associated with blood mercury levels. CONCLUSIONS: In conclusion, we suggest the implementation of systematic and periodic population-based studies to decrease the risks of mercury poisoning among South Koreans who consume fish as a regular part of the diet.

The Effect of Silk Fibroin/Nano-hydroxyapatite/Corn Starch Composite Porous Scaffold on Bone Regeneration in the Rabbit Calvarial Defect Model

0.05).CONCLUSION: The rabbit calvarial defect was not successfully repaired by silk fibroin/nano-hydroxyapatite/corn starch composite scaffold and may have been due to an inflammatory reaction caused by silk powder. In the future, the development of composite bone graft material based on various components should be performed with caution.

Pathologic Fractures of the Mandible