• Korean Journal of Culture and Social Issue
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• v.9 no.spc
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• pp.107-122
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• 2003

The object of this study is to evaluate the prevailing physical and psychosocial conditions regarding occupational low back injury. This study consists of two parts. In the first part of the study, analytic biomechanical model and NIOSH guidelines are applied to evaluate risk levels of low back injury for automobile assembly jobs. Total of 246 workers are analysed. There are 20 jobs having greater back compressive forces than 300kg at L5/S1. Also, there are 44 jobs over Action Limit with respect to 1981 NIOSH guidelines. The relationship between psychosocial factors and low back injury was examined in the second part of the study. A battery of questionnaires concerning the psychosocial stress based on PWI (Psychosocial Well-being Index) and musculoskeletal pain symptoms at low back was completed by 246 workers at the same plant. Results showed that 207 out 246 workers experienced the symptoms and 27 workers were diagnosed as patients. Two groups(low stressed, high stressed) based on PWI score had no significant relationships with both symptoms and results of diagnosis. The relationships between physical work load and psychosocial stress were also analysed. Specifically, some postural factors(vertical deviation angle of forearm, horizontal deviation angle of upperarm, vertical deviation angle of thigh, etc) were highly correlated with psychosocial stress. The results illustrated that PWI scores were associated with some physical workloads. However, psychosocial stress levels couldn't be well related with the pain symptom as well as the actual incidence of low back injury since pain or discomfort regarding low back injury were more complex than that of other musculoskeletal disorders.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 1997.06b
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• pp.8-10
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• 1997

종양은 아직 그 발생 원인과 기작이 정확히 밝혀져 있지 않으므로 정확한 정의를 내리는 것은 어려우나 일반적으로 종양이란 정상 세포가 갖고 있는 세포 분열의 특이성을 상실하여 일어나는 조직의 자율적인 과잉 성장을 말한다. 이와 같은 세포의 비정상적인 증식에 의한 종양을 임상 및 병리 형태학적으로 양서 종양과 악성종양으로 분류한다. 양성 종양을 일으키는 종양 세포는 정상 세포와 비슷할 뿐 아니라 그 주변 세포들과 확실한 경계를 이루고 있으며 증식도 느리며 다른 부위로의 전이가 없다. 이에 반해 악성종양은 일반적으로 증식도 빠르고 이형의 세포로서 주변의 조직으로 확산, 전이될 뿐만 아니라 최종적으로 숙주인 개체를 사망시킨다. 악성종양은 다시 상피 조직에서 유례한 암, 비상피 조직에서 유래된 육종, 백혈구에서 유래된 백혈병 등으로 구별하지만 그의 본질은 거의 같으며 모든 악성종양은 통속적으로 암이라고 불리운다. 종양의 발생원인으로 크게 3가지로 나눌 수 있는데 화학물질, 바이러스 및 유전적 요인에 의한 것으로 알려졌다. 최초의 발암물질로 알려진 benzopyrene에 의한 발암 등 연구에 의해 화학적 발암원들은 직접 발암 물질로 작용하는 것이 아니라, 일단 체내에서 대사된 후 이들 대사 산물일 DNA 등에 작용함으로써 발암이 유도 되는 것으로 밝혀졌다. 이와 같이 화학적 변화를 거친 후에야 DNA에 영향을 미치는 것외에 다른 화학물질들은 또 다른 기작을 통해 암을 유발하는데 쥐의 피부에 benzopyrene을 한 번 처리하면 암을 유발하지 않으나 여기에 phorbol ester를 처리하면 높은 빈도로 암이 형성된다. 여기서 benzopyrene과 같이 세포의 DNA에 돌연변이를 일으키는 작용을 하는 발암물질을 발암개시제라 하고 phorbol ester처럼 그 자체로는 발암능이 없으나 발암개시제에 노출된 세포에 영향을 미쳐 발암능을 크게 강화시켜 주는 것을 발암촉진제라고 한다. 암은 세포증식 제어계에 DNA가 이상을 일으킨 현상을 말하는 데 이와 같은 DNA의 변형된 유전정보에 의해 암과 관련된 단백질을 합성하므로 이 DNA를 암유전자라 부르며 바이러스에서 유래된 것을 V-one 그리고 세포에서 유래된 것을 c-one이라 한다. 암유전자는 본래 암을 형성하기 위한 것이 아니라 증식제어 유전자로서 변이나 비정상으로 활성화 됨으로써 암을 유발시키므로 proto-oncogene이라 부른다. 또한 고등동물의 유전자 중에는 세포성장을 억제하는 유전자들이 있으며 이들은 세포의 성장 생존 분화를 조절하는 것으로 생각되고 있다. 따라서 이들 유전자는 세포의 암변형을 억제하는 기능을 가지고 있다. 이들 유전자의 이상으로 세포성장 억제기능이 상실되면 세포의 과잉 성장이 초래되면 결과적으로 암으로 유발하는 것으로 추측되고 있다. 최근의 연구에 의하면 암세포에서 암억제 유전자의 이상과 암유전자의 활성화가 함께 발견 되면서 정상세포가 암으로 변형되는 과정에는 암억제 유전자의 이상과 암유전자의 활성화가 동시에 관여한 가능성이 높은 것으로 알려져 있다. 정상 세포가 암을 유발하기 위해서는 발암의 다단계설에서와 같이 여러 단계의 변과가 필요한데 여러 가지 요인에 의해 정상세포의 염색체가 변화되어 정상세포들이 가지고 있는 세포분열의 특이성을 상실하고 증식이 빠르고 저항력이 강한 세포가 선택 되어지고 비정상 서ㅔ포으 과잉 분여러에 의해 종양이 형성되며 이어서 혈관의 신생을 촉진하는 맥관형성, 전이 등이 과정을 거쳐 신체의 다른 부위로 전이된다. 20세기 초까지는 암은 노화와 함께 자연발생적으로 일어나는 피할 수 없는 질병으로 여겨졌으며 그 치료도 조기에 발견된 암환자에게 외과적인 치료를 하는 것이 최선의 방법 이었다. 그러나 현재에는 암환자의 80% 이상이 환경적 요인에 의해 암이 발생 된다고 믿어지고 있다. 과거 치료에 중점을 둔 것에서 점차 예방의 가능성과 그 방법의 모색에 관심을 갖게 되었으며 치료적인 면에서도 외과적 수술 이외에 방사선 치료, 항암제의 투여 등 약물요법, 면역요법의 이용 이외에 더 나아가 gene theraph 및 tumor vaccines 개발에 대한 관심도 증가되고 있다. 국제암연구협회에서는 인간에게 발암이 가능한 물질의 종류를 정기적으로 발표하고 있는데 지금까지 발암 가능성이 높다고 널리 알려진 위험요인을 크게 나누어 보면 다음과 같다. 흡연, 음주, 식이요인, 호르몬 및 기타 요인으로 약물, 자외선 등을 들 수 있는데 현재까지 이들 요인에 의한 발암 기작이 완전히 규명된 것은 아니지만 이들에 의한 발암의 확률이 높다는 것은 사실이므로 이 위험요인에 노출되는 것을 방지함으로써 암발생을 예방할 수 있을 것이다. 암발생의 예방법으로는 암발생 자체를 예방하는 것과 이미 발생한 암환자를 조기 발견하고 치료하는 방법이 있을 수 있다. 현재까지의 여러 연구 결과들을 보면 유전적인 요인을 제외한 대부분의 발암 위험인자들은 개개인의 생활습관과 밀접히 관련되어 있음을 알 수 있다. 이를 바탕으로 1992년 대한 암협회에서는 '암 예방 14개 권장 사항'을 발표하여 국민 홍보활동을 하고 있는데 그 내용의 반 이상이 식생활 습관과 관련되어 있을 정도이므로 암예방에 있어서의 식품의 역할이 매우 크다 할 수 있다. 따라서 건전한 생활습관과 더불어 적절한 식품의 섭취는 암예방을 위한 기본이 될 것이다.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.511-525
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• 1995

To elucidate some DNA adducts as a biological marker for workers of chromate pigment, the effects of chromium exposure on the formation of 8-hydroxydeoxyguanosine(8-OH-dG) and sister chromatid exchanges(SCEs) frequency in 38 workers of a pigment plant in Bucheon which utilized lead chromates, were examined. The chromium contents of venous blood and urine were measured as working environmental exposure level. The concentrations of 8-OH-dG in DNA isolated from lymphocytes were determined with high performance liquid chromatography and electrochemical detector and denoted as a molar ratio of 8-OH-dG to deoxyguanosine(dG). The SCEs frequency were analyzed in DNA isolated from lymphocytes. A significant correlation was found between creatinine adjusted urine chromium concentration and the molar ratio of 8-OH-dG to dG(r=0.47, p<0.01). After adjusting the current smoking habit, the correlation coefficient was increased(r=0.62, p<0.05). However, there was no significant correlation between the SCE frequency and chromium exposure. This significant results between molar ratio of 8-OH-dG to dG and chromium exposure are in good agreement with in vitro studies that support the importance of DNA adduct formation for the carcinogenic effect of chromium.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.441-446
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• 2009

Background: Side clamping of ascending aorta during proximal graft anastomosis in coronary bypassing surgery in-creases the risk of direct aortic injury as well as embolization of intimal atheroma. Heartstring proximal sealing system (Guidant Corporation, Santa Clara, Calif), developed to avoid aortic side clamping, may minimize risks of such complications. The aim of the current study is to compare the surgical outcomes of the two proximal anastomosis techniquesi.e., Heartstring system versus aortic side clamping in off pump coronary bypassing' surgery (OPCAB). Material and Method: From January 2003 to August 2008, 499 patients underwent OPCAB. Of them, proximal graft anastomosis was performed using Heartstring system in 182 patients (Group I) and conventional manual anastomosis in 317 patients (Group II). The two groups were compared for postoperative major complications and mortality. Result: Two groups showed similar characteristics in terms of preoperative demographic data, left ventricular ejection fraction, renal function and history of diabetes, hypertension and smoking. Although there was no inter-group difference in the history of cerebral ischemia (p=0.48), preoperative brain magnetic resonance angiography revealed greater incidence of severe carotid artery stenosis (>75% of lumen) in the Group I than in the. Group II (44.5% in the Group I and 30.0% in the Group II, p=0.003). There were no inter-group differences in postoperative mortality (p=0.40) and complications (p=0.47) including neurologic events (3 in the Group land 2 in the Group II, p=0.258). Whereas neurologic events all comprised transient ischemic attacks in the Group I, they comprised multiple embolic strokes in the Group II. One patient in the Group II experienced aortic dissection during proximal anastomosis which resulted in ascending aortic replacement. Conclusion: Although proximal anastomosis using Heartstring system did not show statistically significant benefit over aortic side clamping, the. absence of embolic stroke maybe a definite benefit which may be better defined through further studies over a larger cohort.

• Journal of agricultural medicine and community health
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• v.34 no.1
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• pp.87-100
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• 2009

Objectives: This study was conducted to suggest the way to improve the tobacco control program of public health centers in Korea. Methods: A survey with a self-administered questionnaire was conducted among 246 persons in charge of tobacco control work in public health centers nationwide in December, 2006. Frequency analysis was performed with a final sample of 212 respondents with SPSS 12.0 for Windows. Results: The duration of engagement in tobacco control work was less than 3 years among 86.7% of respondents, and 87.3% of respondents had other duties besides tobacco control. Almost all public health centers conducted a campaign with posters or leaflets, and smoking prevention education among adolescents. The actual priority for programs was based on the community diagnosis in only 33.5% of the cases. Only 1.9% of respondents complained lack of budget, on the other hand, 44.7% of respondents appealed insufficient number of personnel. The route of knowledge and skill was largely dependent on self-learning or information from colleague. Collaboration with other related department was done well in 39.5% of the cases. The majority of respondents was satisfied with the general support from central government. Conclusions: To improve the tobacco control program of public health centers, it is needed the reinforcement of capacity and specialty among personnel, priority setting and performance of programs based on the scientific evidence, induction of community participation, utilization of community human resources, development of education and training course for practical skill, effective networking among departments.

• Journal of agricultural medicine and community health
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• v.34 no.1
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• pp.13-23
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• 2009

Objective: The objective of this study was to evaluate the association of social support with health status and health behavior. Methods:　This study was conducted with 79 elderly people in Gunja-ri, Dongsan-myun, Chuncheon. We performed face to face interview which was composed of socio-demographic characteristics, social support, health status and health behavior. The association between social support and result variables was analysed by Chi-square test and logistic regression. We used SAS ver9.1 for statistic analysis. Results: Mean age of the study population was 72.0$\pm$7.0, social support score was 14.3$\pm$4.7 with full marks of 20 and 36.25% of the total population were shown to have depression. When the social support score was changed, depression (p=0.0007) and physical exercise (p=0.0312) showed significant difference. The self-rated health status was significantly related to the relationship with family members (OR=0.25, 95% CI=0.07-0.95) and the quality of sleep was also significantly associated to the relationship with family members (OR=0.21, 95% CI=0.06-0.73). The physical exercise was done significantly less in the group without close friends than in the group with many close friends (OR=0.21, 95% CI=0.05-0.94) and the depression was significantly more in the group without community participation than in the group with community participation (OR=4.79, 95% CI=1.62-14.15). Conclusions: Through this study, we could conclude that the social support factors are associated with health status and health behavior. Therefore, to improve the health status of rural elderly, we need to approach to develop social support.

• Sleep Medicine and Psychophysiology
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• v.9 no.1
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• pp.48-55
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• 2002

Objective: Stress is known to be a common cause of short-term insomnia and insomniacs often complain that stress induces sleep problems. However, previous studies on the correlation between stress and sleep do not show consistent results. We aimed to investigate the effects of minor stressful events on sleep among college students. Method: Physically and mentally healthy college student volunteers filled out a self-assessment questionnaire to evaluate their stress and sleep. To find out the status of average stress and sleep, the volunteers filled out K-DSI and daily sleep assessments on three consecutive days. In addition, we surveyed the amount of caffeine beverage intake and assessed the degree of depression and anxiety. Results: The total number of students participating in this study was 202, 101 men and 101 women. Minor stress turned out to significantly affect non-restorative sleep and secondary symptoms of insomnia (awakening difficulty, displeasure, feeling of dissatisfaction with sleep, physical uneasiness or pain at awakening, daytime sleepiness, depressive moods, tiredness and concentration difficulty). However, global PSQI score, self-reported sleeping hours, sleep latency, awakening frequency, frequency and duration of napping, were not explained by stress scores. Conclusion: In this study, minor stresses seemed to affect sleep, especially secondary symptoms caused by non-restorative sleep. We can thus infer that minor stresses impair the restorative effects of sleep by inducing arousal, and the direct relationship the two can be confirmed by polysomnogram.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.88-97
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• 2003

Background : Although smoking is a major cause of chronic obstructive pulmonary disease (COPD), only 10-20% of cigarette smokers develop symptomatic COPD, which suggests the presence of genetic susceptibility. This genetic susceptibility to COPD might depend on variations in the activities of the enzyme that detoxify hazardous chemical products, such as microsomal epoxide hydrolase (mEPHX) and glutathione-S transferase M1 subunit (GSTM1) genes. Methods : The genotypes of 58 patients with COPD, and 79 age matched control subjects, were determined by a polymerase chain reaction, followed by restriction fragment length polymorphism (PCR-RFLP) for the mEPHX, and multiplex PCR for the GSTM1. Results : GSTM1 was deleted in 53.3% of the subjects. There was no difference in GSTM1 deletion rates between the COPD patients (32/58, 55.2%) and the control subjects (41/79, 51.9%). The combination patterns of two polymorphisms of mEPHX showed slow enzyme activity in 29(21.2%), normal in 73(53.3%) and fast in 32(23.4%). The COPD group (7/57, 12.3%) showed a significantly lower incidence of slow enzyme activity compared to the control subjects (22/77, 28.6%, p<0.05). However, when the COPD and control groups were compared with smokers only, there were no significant differences in the genotypes of GSTM1 and mEPHX. Conclusion : The genotypes of GSTM1 and mEPHX were not significant risk factors of COPD in this cohort of study.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.560-569
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• 2003

Background : A large number of pollutants such as sulfur dioxide, nitric oxide, carbon monoxide, particulate matter, and ozone influence on the body. These pollutants put a burden on the lung and the sequelae resulting from the oxidative stress are thought to contribute to the development of fibrotic lung disease, emphysema, chronic bronchitis and lung cancer. Also, carbon monoxide generated from the incomplete combustion of carbon-containing compounds is an important component of air pollution caused by traffic exhaust fumes and has the toxic effect of tissue hypoxia and produce various systemic and neurologic complications. The objective of this study is to compare the difference of pulmonary function and serum carboxyhemoglobin(CO-Hb) level between the traffic policemen and clerk policemen. Method : Three hundred and twenty-nine of traffic policemen, and one hundred and thirty clerk policemen were included between 2001 May and 2002 August. The policemen who took part in this study were asked to fill out a questionnaire which included questions on age, smoking, drinking, years of working, work-related symptoms and past medical history. The serum CO-Hb level was measured by using carboxyoximeter. Pulmonary function test was done by using automated spirometer. Additional tests, such as elecrocardiogram, urinalysis, chest radiography, blood chemistry, and CBC, were also done. Results : $FEV_1(%)$ was $97.1{\pm}0.85%$, and $105.7{\pm}1.21%$(p<0.05). FVC(%) was $94.6{\pm}0.67%$, and $102.1{\pm}1.09%$, respectively(p<0.05). Serum CO-Hb level was $2.4{\pm}0.06%$, and $1.8{\pm}0.08%$(p<0.05). After correction of confounding factors (age, smoking), significant variables were FVC(%), $FEV_1(%)$ and serum CO-Hb level(%)(p<0.05). Conclusion : Long exposure to air pollution may influence the pulmonary function and serum CO-Hb level. But, further prospective cohort study will be needed to elucidate detailed influences of specific pollutants on pulmonary function and serum carboxyhemoglobin level.

• Journal of agricultural medicine and community health
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• v.38 no.2
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• pp.116-129
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• 2013

Objectives: This study was performed to identify the associations of social capital with suicidal thoughts and attempts in Korean communities with poor health. Methods: We used the data from community health interviews conducted at 40 administrative sections (dong, eup, or myeon) with high mortality from August to October in 2010, 2011, and 2012 as part of the Health Plus Happiness Plus Projects in Gyeongsangnam-do Province. The 8,800 study subjects composed of 220 adults systematically sampled from each administrative section were asked if they had thought about suicide or had attempted suicide within 1 year. The social participation was measured with 'participation in formal and/or informal group' and trust using responses to three questions about trust of others. Results: The prevalence of suicidal ideation and attempt within 1 year were 10.4% and 0.8%, respectively. The logistic regression analysis revealed that those who participated in only informal groups, or had highest trust level reported less suicidal ideation, or attempt after adjusting for socio-demographic factors (sex, age, marital status, occupation, and food affordability), self-rated health, and health behaviors (smoking, alcohol drinking, and exercise). Conclusions: This study suggested social capital such as social participation and trust was associated with less suicide ideation and attempt. More studies are warranted for the association of social capital with suicidal behavior.