NK Cell-Based Immunotherapies in Cancer

With the development of technologies that can transform immune cells into therapeutic modalities, immunotherapy has remarkably changed the current paradigm of cancer treatment in recent years. NK cells are components of the innate immune system that act as key regulators and exhibit a potent tumor cytolytic function. Unlike T cells, NK cells exhibit tumor cytotoxicity by recognizing non-self, without deliberate immunization or activation. Currently, researchers have developed various approaches to improve the number and anti-tumor function of NK cells. These approaches include the use of cytokines and Abs to stimulate the efficacy of NK cell function, adoptive transfer of autologous or allogeneic ex vivo expanded NK cells, establishment of homogeneous NK cell lines using the NK cells of patients with cancer or healthy donors, derivation of NK cells from induced pluripotent stem cells (iPSCs), and modification of NK cells with cutting-edge genetic engineering technologies to generate chimeric Ag receptor (CAR)-NK cells. Such NK cell-based immunotherapies are currently reported as being promising anti-tumor strategies that have shown enhanced functional specificity in several clinical trials investigating malignant tumors. Here, we summarize the recent advances in NK cell-based cancer immunotherapies that have focused on providing improved function through the use of the latest genetic engineering technologies. We also discuss the different types of NK cells developed for cancer immunotherapy and present the clinical trials being conducted to test their safety and efficacy.

Comparison of Long Term Follow-up Chest CT Imaging in Adult and Pediatric Patients with Humidifier Disinfectant-related Lung Injury

Background@#To compare the chest computed tomography (CT) images of children and adults in families with clusters of humidifier disinfectant-related lung injury (HDLI) after cessation of exposure to humidifier disinfectant (HD). @*Methods@#We reviewed medical records of 19 families with 43 patients (21 adults, 22 children) among families, which had at least one adult and one child with HDLI. Each family was exposed to the same HD exposure environment. @*Results@#In adults, centrilobular nodules were predominant (95.2%) in chronic HDLI findings after cessation of exposure to HD, however, in children, normal pattern was most prevalent on chest CT (45.5%), followed by centrilobular nodule (36.4%), bizarre lung cysts (36.4%), and reticulation (13.6%). @*Conclusion@#Unlike the known chronic HDLI finding of adults, centrilobular nodules were only present in 36.4% of children. The frequency of bizarre lung cysts were significantly greater in children than that in adults after cessation of similar exposure to HD. Thus, bizarre lung cysts may be useful as another novel finding of chronic HDLI in children who have no history of pulmonary infection or other perinatal disorder such as hyaline membrane disease or other interstitial lung disease.

Effects of job stress on symptoms of bipolar spectrum disorder in an electronic parts manufacturing company

Background@#Mental illness is known to be caused by genetic, biological, and environmental risk factors. Although previous studies have established the link between mental illness and job stress, most of them are limited to major depression disorder. Therefore, this study examined the relationship between job stress and bipolar spectrum disorder (BSD). @*Methods@#This is a cross-sectional study based on a survey conducted in April 2017 at an electronic parts manufacturing company in Busan. In a total of 441 workers, the degree of BSD was identified using the Korean version of the Mood Disorder Questionnaire, and the degree of job stress was identified using the Korean Occupational Stress Scale Short Form.This study also identified general characteristics of workers and job-related factors. The χ2 test and Fisher's exact test was conducted to determine the differences among the variables, based on BSD. Multiple logistic regression analysis was conducted to determine the influence of independent variables on BSD. @*Results@#Cross-analysis showed significant differences between the BSD high-risk and lowrisk groups regarding age, sex, occupation, smoking, problem drinking, job stress total score, occupational climate, and major depression disorder symptom. In addition, the significant differences between the BSD high-risk and low-risk groups about job stress were observed in terms of job demand, job insecurity, and occupational climate. A multiple logistic regression analysis revealed that the high-risk group in the job stress group had a higher effect on BSD than the low-risk group (odds ratio [OR]: 2.32, 95% confidence interval [CI]: 1.10–4.88). Among the categories of job stress, high-risk groups in 3 areas—job demand (OR: 2.56, 95% CI: 1.27–5.17), job insecurity (OR: 4.42, 95% CI: 1.19–16.42), and occupational climate (OR:2.55, 95% CI: 1.29–5.05)—were more likely to have an impact on BSD than the low-risk groups. @*Conclusions@#This study demonstrated that the high-risk groups of job stress total score, job demand, job insecurity, and occupational climate had a more significant effect on BSD than the low-risk groups. As workers with BSD may have difficulties in their work and personal lives, there is a need to manage job stress to prevention of BSD.

Effects of job stress on symptoms of bipolar spectrum disorder in an electronic parts manufacturing company

Background@#Mental illness is known to be caused by genetic, biological, and environmental risk factors. Although previous studies have established the link between mental illness and job stress, most of them are limited to major depression disorder. Therefore, this study examined the relationship between job stress and bipolar spectrum disorder (BSD). @*Methods@#This is a cross-sectional study based on a survey conducted in April 2017 at an electronic parts manufacturing company in Busan. In a total of 441 workers, the degree of BSD was identified using the Korean version of the Mood Disorder Questionnaire, and the degree of job stress was identified using the Korean Occupational Stress Scale Short Form.This study also identified general characteristics of workers and job-related factors. The χ2 test and Fisher's exact test was conducted to determine the differences among the variables, based on BSD. Multiple logistic regression analysis was conducted to determine the influence of independent variables on BSD. @*Results@#Cross-analysis showed significant differences between the BSD high-risk and lowrisk groups regarding age, sex, occupation, smoking, problem drinking, job stress total score, occupational climate, and major depression disorder symptom. In addition, the significant differences between the BSD high-risk and low-risk groups about job stress were observed in terms of job demand, job insecurity, and occupational climate. A multiple logistic regression analysis revealed that the high-risk group in the job stress group had a higher effect on BSD than the low-risk group (odds ratio [OR]: 2.32, 95% confidence interval [CI]: 1.10–4.88). Among the categories of job stress, high-risk groups in 3 areas—job demand (OR: 2.56, 95% CI: 1.27–5.17), job insecurity (OR: 4.42, 95% CI: 1.19–16.42), and occupational climate (OR:2.55, 95% CI: 1.29–5.05)—were more likely to have an impact on BSD than the low-risk groups. @*Conclusions@#This study demonstrated that the high-risk groups of job stress total score, job demand, job insecurity, and occupational climate had a more significant effect on BSD than the low-risk groups. As workers with BSD may have difficulties in their work and personal lives, there is a need to manage job stress to prevention of BSD.

A case of extensor pollicis longus (EPL) tendon rupture in an automotive assembly line worker: an ergonomic evaluation through job strain index (JSI) and musculoskeletal risk factor survey

BACKGROUND: We report a case of extensor pollicis longus (EPL) tendon rupture caused by repetitive motions and awkward posture on hand and wrist joints. CASE PRESENTATION: A 47-year-old right-handed man who worked for 15 years in an assembly line at an automotive manufacturing company has been diagnosed with a complete tear of right EPL tendon. We investigated the patient's occupational history in detail and evaluated the tasks ergonomically through musculoskeletal risk factors survey and job strain index (JSI) using the 22 task-related videos recorded by the patient. Three out of the 12 tasks (25%) were identified as high-risk work on the hand and wrist in the musculoskeletal risk factors survey in 2016. Among the 22 tasks analyzed by JSI, 11 tasks (50%) were evaluated as probably hazardous. In addition, he used localized vibration tools in 19 (86.4%) out of 22 tasks. CONCLUSION: We concluded the patient's disease was probably caused by repetitive motion and improper posture of the hand and wrist, and the hand-arm vibration is a possible cause as well.

Review of carcinogenicity of hexavalent chrome and proposal of revising approval standards for an occupational cancers in Korea

BACKGROUND: The objective of this study is to suggest revised recognition standards for occupational disease due to chromium (VI) by reflecting recent domestic and international research works and considering domestic exposure status with respect to target organs, exposure period, and cumulative exposure dose in relation to the chromium (VI)-induced occupational disease compensation. METHODS: In this study, the reports published by major international institutions such as World Health Organization (WHO) International Agency for Research on Cancer (IARC) (2012), Occupational Safety and Health Administration (OSHA) (2006), National Institute for Occupational Safety and Health (NIOSH) (2013), American Conference of Governmental Industrial Hygienists (ACGIH) (2004), National Toxicology Program (NTP) (2014), and Agency for Toxic Substances and Disease Registry (ASTDR) (2012) were reviewed and the recent research works searched by PubMed were summarized. RESULTS: Considering the recent research works and the domestic situation, only lung cancer is conserved in the legislative bill in relation to chromium (VI), and the exposure period is not included in the bill. Nasal and paranasal sinus cancer was excluded from the list of cancers that are compensated as the chromium (VI)- induced occupational disease, while lung cancer remains in the list. In the view of legislative unity, considering the fact that only the cancers having sufficient evidence are included in the conventional list of cancers compensated as occupational disease, nasal and paranasal sinus cancer having limited evidence were excluded from the list. The exposure period was also removed from the legislative bill due to the insufficient evidence. Recent advices in connection with cumulative exposure dose were proposed, and other considerable points were provided with respect to individual occupational relevance. CONCLUSIONS: It is suggested that the current recognition standard which is “Lung cancer or nasal and paranasal sinus cancer caused by exposure to chromium (VI) or compounds thereof (exposure for two years or longer), or nickel compounds” should be changed to “Lung cancer caused by exposure to chromium (VI) or compounds thereof, and lung cancer or nasal and paranasal sinus cancer caused by exposure to nickel compounds”.

An aggravated return-to-work case of organic solvent induced chronic toxic encephalopathy

BACKGROUND: Organic solvent-induced chronic toxic encephalopathy (CTE) is known as a non-progressive disorder that does not progress after diagnosis. The authors present a case those symptoms worsened after continued exposure to organic solvent after returning to work. Because such a case has not been reported in South Korea to the best of our knowledge, we intend to report this case along with literature review. CASE PRESENTATION: A 59-year-old man, who performed painting job at a large shipyard for 20 years, was receiving hospital treatment mainly for depression. During the inpatient treatment, severe cognitive impairment was identified, and he visited the occupational and environmental medicine outpatient clinic for assessing work relatedness. In 1984, at the age of 27, he began performing touch-up and spray painting as a shipyard painter. Before that he had not been exposure to any neurotoxic substances. In 2001, at the age of 44, after 15 years of exposure to mixed solvents including toluene, xylene and others, he was diagnosed with CTE International Solvent Workshop (ISW) type 2A. After 7 years of sick leave, he returned to work in 2006. And he repeated return-to-work and sick leave in the same job due to worsening of depressive symptoms. He had worked four times (2006–2010, 2011–2011, 2011–2011, 2016–2017) for a total of 5 years as a shipyard painter after first compensation. During the return-to-work period, the mean values of the mixed solvent index ranged from 0.57 to 2.15, and except for a one semiannual period, all mean values were above the standard value of 1. We excluded other diseases that can cause cognitive impairment like central nervous system diseases, brain injury, psychological diseases and metabolic diseases with physical examinations, laboratory tests, and brain image analysis. And finally, throughout neuropsychological tests, an overall deterioration in cognitive function was identified compared to 2002, and the deterioration types was similar to that often shown in the case of CTE; thus a diagnosis of CTE (ISW) type 3 was made. CONCLUSION: This case is showing that CTE can go on with continued exposure to mixed solvents. Appropriate “fitness to work” should be taken to prevent disease deterioration especially for the sick leave workers.

Ovarian cancer in a former asbestos textile factory worker: a case report

BACKGROUND: The International Agency for Research on Cancer (IARC) defined that asbestos is a group 1 substance that causes lung cancer, mesothelioma (pleura and peritoneum), laryngeal cancer, and ovarian cancer in humans. Many studies on lung cancer, and mesothelioma caused by asbestos exposure have been conducted, but there was no case report of ovarian cancer due to asbestos exposure in Korea. We describe a case of ovarian cancer caused by asbestos exposure in a worker who worked at an asbestos textile factory for 3 years and 7 months in the late 1970s. CASE PRESENTATION: A 57-year-old woman visited the hospital because she had difficulty urinating. Ovarian cancer was suspected in radiologic examination, and exploratory laparotomy was performed. She was diagnosed with epithelial ovarian cancer. The patient did not undergo postoperative chemotherapy and recovered. She joined the asbestos factory in March 1976 and engaged in asbestos textile twisting and spinning for 1 year, 2 years and 7 months respectively. In addition, she lived near the asbestos factory for more than 20 years. There was no other specificity or family history. CONCLUSION: Considering the patient’s occupational and environmental history, it is estimated that she had been exposed to asbestos significantly, so we determined that ovarian cancer in the patient is highly correlated with the occupational exposure of asbestos and environmental exposure is a possible cause as well. Social devices are needed to prevent further exposure to asbestos. It is also necessary to recognize that ovarian cancer can occur in workers who have previously been exposed to asbestos, and the education and social compensation for those workers are needed.

Antidepressants Use in Schizophrenia: Clinical Correlates and Prescription Profiles / 신경정신의학

OBJECTIVES: To identify recent prescription patterns, as well as the demographic and clinical correlates of antidepressants (ADs) usage in schizophrenic patients. METHODS: A total of 297 patients diagnosed with schizophrenia enrolled at Seoul National Hospital in 2013. Brief Psychiatric Rating Scale (BPRS) was used to evaluate current psychiatric symptoms. Bivariate comparisons were used to assess the usage of concomitant psychotropics, demographic and clinical characteristics of ADs users compared with non-users. Multivariate analysis of covariance was performed consecutively. RESULTS: The rate of ADs usage was 26.3% and the most commonly used ADs were selective serotonin reuptake inhibitors. ADs users more often took benzodiazepine than ADs non-users (p=0.005), whereas there were no significant demographic and other clinical difference between the two groups. Regarding BPRS, somatic concern (p=0.022), anxiety (p=0.001) and depressive mood (p=0.009) scores were higher, and excitement (p=0.006) and hostility (p=0.04) scores were lower among ADs users compared to non-users, although there was no significant difference in the other scores of BPRS between the two groups. Moreover, among 5 components of BPRS, scores of affective symptoms (p < 0.001) were significantly higher, and scores of activation symptoms (p=0.014) were significantly lower in ADs users compared to non-users. CONCLUSION: This study suggests that the usage of ADs could be related to affective symptoms regardless of positive and negative symptoms of schizophrenia. Further studies are required in order to confirm the clinical correlates of ADs usage and the interactions between affective symptoms and psychotic symptoms.

Residency programs and the outlook for occupational and environmental medicine in Korea

OBJECTIVES: This study investigated the implementation of training courses and the overall outlook for occupational and environmental medicine (OEM) in Korea. We described the problems facing OEM residency programs in Korea, and reviewed studies dealing with the specialty of occupational health in developed countries in order to suggest directions of improvement for the OEM training courses. METHODS: We surveyed 125 OEM residents using a questionnaire in August 2012. A total of 23 questions about the training environment, residency programs, preferred institutions for post-licensure employment, and the outlook for OEM specialists were included in the questionnaire and analyzed according to the type of training institution and residency year. Responses from 88 residents (70.4 %) were analyzed. RESULTS: The major responsibilities of OEM residents were found to vary depending on whether they were trained in research institutes or in hospitals. OEM residents had a lower level of satisfaction with the following training programs: toxicology practice (measurements of biological markers, metabolites, and working environments), and OEM practice (environmental diseases and clinical training involving surgery). When asked about their eventual place of employment, OEM residents preferred institutions providing special health examinations or health management services. OEM residents reported a positive outlook for OEM over the next 5 years, but a negative outlook for the next 10 years. CONCLUSIONS: Although a standardized training curriculum for OEM residents exists, this study found differences in the actual training courses depending on the training institution. We plan to standardize OEM training by holding a regional conference and introducing open training methods, such as an open hospital system. Use of Korean-language OEM textbook may also reduce differences in the educational programs of each training institution. Toxicology practice, environmental diseases, and clinical training in surgery are areas that particularly need improvement in OEM residency training programs.

Physical Agents and Occupational Disease Compensation: Noise, Vibration, Radiation, and Other Physical Agents

The context of specific criteria for the recognition of occupational diseases (ODs) due to physical agents in the Enforcement Decree of the Industrial Accident Compensation Insurance Act (ED-IACIA) and the Labor Standard Act (LSA) does not describe definite disease along with the agents but listed symptoms or obscure clinical conditions. Moreover, the needs for an amendment of these Acts have recently attracted renewed interest. To establish agreed criteria for compensable ODs due to physical agents, we reviewed the criteria for recognizing ODs on the basis of International Labor Organization (ILO) documents and European Union (EU) guideline. After providing a brief review of the history of OD outbreaks due to physical exposure in South Korea and the responses to them, we describe the basis for the recent amendments to the IACI Act and LSA and assess their appropriateness. On the basis of these findings, this study could be helpful for determining and compensating process of ODs. However, further work is required to ascertain the scientific relationship between diseases caused by physical agents and the exposure criteria.

Risk factors of musculoskeletal symptoms in university hospital nurses

OBJECTIVES: The purpose of this study was to investigate musculoskeletal symptom prevalence in university hospital nurses and explore the relation between musculoskeletal symptom prevalence and work related factors. METHODS: A structured questionnaire was conducted with 620 nurses in a university hospital to look into the characters of responsibility and musculoskeletal symptom prevalence. The questionnaire respondents numbered 534, so the response rate was 86.1%. Among the respondents, three who gave insincere answers were excluded. The final study population was 531 respondents. ANSI Z-365 checklist was applied to look into ergonomic characteristics, and Korean Occupational Stress Scale Short Form was employed to measure job stress. RESULTS: In the case of the whole body, symptom prevalence amounted to 70.8%. Regarding each body region, shoulder symptom prevalence accounted for the highest, or 44.8%, waist 40.7%, and neck 33.3% in order. According to multiple logistic regression analysis, in the case of the whole body, the group with a high ANSI checklist grade had odds ratio of 3.59 (95% CI 1.48 ~ 8.76), and the group with high job stress had 3.19 (95% CI 2.01 ~ 5.07). CONCLUSION: Regarding the occupational factors related to musculoskeletal symptoms of university hospital nurses, it was found that ANSI Z-365 checklist high risk group, total job tenure, department, shiftworks, and job stress had high relation with musculoskeletal symptoms. It is necessary to find an ergonomic solution and a stress reduction plan to prevent musculoskeletal disease.

Epidemiology and Causation / 고신대학교의과대학학술지

In medicine and public health areas, it is essential for researchers and clinicians to investigate causal relationships dealing with the terms of cause, causation and causality. In treating a patient, the treatment will be given based on the assumption that that treatment will cause an improvement or cure of the patient. For diagnosis, we need a causation concept to associate diseases with etiologic factors such as genetic, environmental, occupational and other components. The prevention and intervention of a disease involve the selecting process of probable causal factors too. The causal problem is one of main issues in philosophy since ancient Greek. Aristotle theorized material, formal, efficient, and formal causes. Francis Bacon and Descartes mainly used induction and deduction, respectively. Hume denied the capacity of inductive methodologies to find truth. Among philosophers of science, the debates whether we can find objective truth or not will be continued. This causation can be two subsets, ontological and epistemological (or methodological). Traditional philosophical approaches mainly focus on ontological problems, such as what is causation?; are there causal laws? In general, scientific or epidemiological approaches are dealing with the epistemological dimension, i.e, causation criteria; test for a causal hypothesis. For clinicians and researchers in medical and public health, it would be a good chance to review and re-think the notions of cause, causation and causality. Also there will be helpful understanding of more detail informations about the methodology such as causal inference, Hill's criteria and Rothman's causal pie model.

Nonspecific Building Related Illnesses / 대한산업의학회지

Nonspecific building related illnesses (NBRI) are an array of diverse symptoms related to working in particular buildings. There are numerous contributing factors, including basic factors (temperature, humidity and ventilation) as well as chemicals, dust, microorganisms, and psychosocial factors. At the individual level, taking a careful history is the essential first step. After ruling out other diseases, clinicians can start the symptomatic treatment for NBRI. If a relationship to the building is suspected, a walk through evaluation is very helpful. At the group level, standardized questionnaires and investigations of the building environment can be applied simultaneously. If the prevalence of symptoms are greater than that of general population, appropriate interventions have to be provided for prevention and group health care. In both approaches, it is essential to periodically follow up with symptomatic patients and work environments after an intervention. For the management of NBRI, taking care of the patient's symptoms and maintaining a good indoor environment are important. To achieve this goal, cooperation among workers, building managers, employers and occupational health staff is crucial.

Estimation of Demand and Supply for Occupational and Environmental Medicine Specialties in Korea (I): Estimation of Supply / 대한산업의학회지

OBJECTIVES: To estimate the supply of occupational and environmental medicine specialties in the target year of 2020. METHODS: We adopted alternative projection models combined with a demographic method as a supply forecasting method. The model uses data selected primarily from the database of the Korean Society of Occupational and Environmental Medicine (KSOEM), a survey for certified members of KSOEM, audit data from the Ministry of Employment and Labor (MOEL) and Hospital Accreditation. We assumed five viable alternatives in supply forecasting. RESULTS: Depending on the assumptions, the total occupational and environmental medicine specialties supply ranged from 706 by low-level supply estimates to 754 by high-level supply estimates in 2020. Among them, approximately 81% were estimated to engage themselves in agency for health management and periodic health examinations for workers exposed to hazards. CONCLUSIONS: The study results suggest that the supply of occupational and environmental medicine specialties is related to the policy of MOEL. Further studies are needed concerning overall policy about health and safety and for the newly demanded market.

Estimation of Demand and Supply for Occupational and Environmental Medicine Specialties in Korea (II): Demand Estimation and Demand-Supply Balance / 대한산업의학회지

OBJECTIVES: To estimate the demand and demand-supply balances of occupational and environmental medical specialties (OEMS) in the target year of 2020. METHODS: We adopted a new OEMS demand model based on the situations of periodic workers' health examination (PHE) agencies, health management agencies (HMA), and legal enforcement for health and safety systems in Korea. The model uses data selected primarily from the database of the Korean Society of Occupational and Environmental Medicine (KSOEM), a survey for certified members of KSOEM, statistics and internal documents from the Ministry of Employment and Labor (MOEL). RESULTS: From the data and assumptions, newly demanded OEMS were 193 for workers who had received PHE, and 205 based on total workers for PHE in 2020 for PHE. But no OEMS for HMA area is demanded. Comparing with the calculated numbers of supply estimates, the demand was slightly higher, but could be balanced if MOEL kept consistent and unchanging policies. CONCLUSIONS: The study results suggest that the demand-supply balance of OEMS is mainly influenced by the policy of MOEL. Further studies are needed examining more detailed data and statistics about PHE agencies, HMA and considering MOEL policies are needed to configuring more sophisticated and need-included estimation.

The Effects of the Structural Unemployment on Health-related Behavior and Health / 대한산업의학회지

OBJECTIVES: This study aimed to examine the effects of unemployment on health-related behavioral changes and worker's health, and to produce the basic data that is needed to formulate the necessary measures for reducing the health hazards and social costs caused by unemployment. METHODS: A questionnaire survey was conducted with a group of 123 people who had lost their jobs due to structural unemployment (the unemployment group) and with a group of 155 employed people (the employment group). The 36-Item Short-Form Health Survey (SF-36) was used as a tool for evaluating the demographic characteristics, the health-related behaviors and the health level. RESULTS: Irregular mealtimes and increased smoking and drinking rates were observed in the unemployment group (P<0.05). The results of the logistic regression analysis that was conducted after correcting for the confounding variable showed that in the unemployment group, unlike in the employment group, the odds ratio of the group with a low health level score on the SF-36 has a significant difference in "Role limitation resulting from physical problems" (OR 2.20, 95% CI=1.01~4.78), "Role limitation resulting from emotional problems" (OR 4.51, 95% CI=1.90~10.69) and "Mental health" (OR 3.43, 95% CI=1.52~7.74) among the eight lower areas. CONCLUSIONS: Unemployment causes a negative change in health-related behaviors and lower levels of mental and physical health. Systematic research must be conducted to promote good health among unemployed workers and to reduce their social costs.

A Case of Chronic Renal Failure and Renal Cancer in a Worker Exposed to Lead / 대한산업의학회지

INTRODUCTION: Studies evaluating rats and mice have provided convincing evidence that renal adenoma and carcinoma are induced by oral doses of lead acetate and lead subacetate, as well as by parenteral doses of lead phosphate. In addition, at least 2 cases of kidney cancer associated with heavy exposure to lead have been reported. However, there is still not enough information to confirm or rule out an association between kidney cancer and exposure to lead. CASE REPORT: In this study, we describe a case of kidney cancer in 54-year-old male worker that was exposed to lead-stearate while employed in the polyvinyl chloride processing industry for 17 years. The patient presented with gout and hypertension. Further examination revealed proteinuria, glucose in the urine and elevated blood urea nitrogen/creatinine levels. Renal ultrasonography, renal computed tomography and renal biopsy revealed chronic renal failure and renal cell cancer. CONCLUSION: We concluded that the gout and chronic renal failure in this case was caused by chronic lead exposure. However, further study is required to determine if the renal cancer was induced by lead exposure.

Work Related Factors Affecting Perceived Fatigue in Male Metal Assemblers / 대한산업의학회지

OBJECTIVES: To find work related factors affecting perceived fatigue among male metal product assemblers. METHODS: The study subjects were metal product assemblers from three metal product companies (476 car parts assemblers, 610 car engine assemblers, 454 ship engine assemblers). From the total of 1,540 subjects, 1,136 (73.8%) were included and 38 respondents with insufficient replies were excluded. Associations between fatigue score and other variables (general characteristics, job related factors, workload, job stresses) were investigated in terms of the concept of multidimensional fatigue construct by self administered questionnaire. Using MFS (Multidimensional Fatigue Scale), JCQ (Job Content Questionnaire), and Borg's scale, we estimated the fatigue, job stress, and workload, respectively. Fatigue score was estimated by 'sum of fatigue' in MFS. Associations were tested by linear regression analysis using SAS v.8.0. RESULTS: In this study, the fatigue related factors were older age, longer working hours per week, higher workload, higher job demand, lower decision latitude, and lower supervisor support. CONCLUSIONS: Prolonged working hours, higher workload, higher job demand, poor supervisor support and lower decision latitude were fatigue related factors among the male metal product assemblers of this study.

Reliability and Validity of Questionnaire for Assessing Physical Workloads / 대한산업의학회지

OBJECTIVES: The aims of the study were to make a questionnaire for assessing physical workloads and to evaluate its reliability and validity. METHODS: A total of 220 workers (foundry workers 30, large vehicle assemblers 30, shipyard workers 75, and automobile manufacturers 80) completed a self-administered questionnaire and took examinations for physical work capacity and working heart rate. We excluded data with insufficient responses or incorrect physical work capacity and working heart rate. Finally, the data of 154 workers (70.0%) were used for our study. In order to evaluate the reliability and validity of the questionnaire, we used statistical analyses including the scaling assumption test and a comparison with the objective tool for physical workload which was evaluated by working energy expenditure. RESULTS: The items of the questionnaire in the same categories had close distribution in the evaluation of the scaling assumption. The item internal consistency was 0.41-0.73 for posture factor, and 0.62-0.79 for non-posture factor. The item discriminate validity was 100%. Cronbach's alphacoefficient of the total items was 0.73 (0.58 for posture factor and 0.74 for nonposture factor). In the correlation between working energy expenditure and questions, general physical activity (p=0.008), proportion of the workday with hands above shoulder (p=0.002), proportion of the workday with trunk bent (p=0.028), proportion of the workday with awkward posture (p=0.048), sweating after work (p=0.006), total scales (p=0.003) and Borg scale (p=0.011) all had statistical significance. CONCLUSIONS: Our questionnaire for assessing physical workloads demonstrated statistically significant reliability and validity. But the questions for the proportions of the workday with sitting work posture and with static posture should be modified via a larger study.