• Journal of Preventive Veterinary Medicine
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• v.42 no.4
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• pp.177-181
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• 2018

Disulfiram is a drug used to treat alcohol dependence. Recent studies have shown that disulfiram also has anti-cancer effects. Considering that many anti-cancer agents have side effects, including immunosuppression, it is important to check if disulfiram has some cytotoxicity to immune cells. In this study, mouse spleen cells were treated with disulfiram and the metabolic activity was measured. Disulfiram increased the cell death of spleen cells according to annexin V-FITC/PI staining analysis. In addition, disulfiram decreased the mitochondrial membrane potential of spleen cells. The toxicity of disulfiram was concentration dependent. Interestingly, disulfiram affected the population of lymphocytes and the subset of spleen cells was altered. This study provides clinicians and researchers with valuable information regarding the toxicity of disulfiram to mouse spleen cells, particularly lymphocytes.

• Journal of Preventive Medicine and Public Health
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• v.56 no.4
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• pp.303-311
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• 2023

Traditional mediation analysis, which relies on linear regression models, has faced criticism due to its limited suitability for cases involving different types of variables and complex covariates, such as interactions. This can result in unclear definitions of direct and indirect effects. As an alternative, causal mediation analysis using the counterfactual framework has been introduced to provide clearer definitions of direct and indirect effects while allowing for more flexible modeling methods. However, the conceptual understanding of this approach based on the counterfactual framework remains challenging for applied researchers. To address this issue, the present article was written to highlight and illustrate the definitions of causal estimands, including controlled direct effect, natural direct effect, and natural indirect effect, based on the key concept of nested counterfactuals. Furthermore, we recommend using 2 R packages, 'medflex' and 'mediation', to perform causal mediation analysis and provide public health examples. The article also offers caveats and guidelines for accurate interpretation of the results.

• Journal of Preventive Medicine and Public Health
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• v.45 no.5
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• pp.323-328
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• 2012

Objectives: Economic growth and development of medical technology help to improve the average life expectancy, but the western diet and rapid conversions to poor lifestyles lead an increasing risk of major chronic diseases. Coronary heart disease mortality in Korea has been on the increase, while showing a steady decline in the other industrialized countries. An age-period-cohort analysis can help understand the trends in mortality and predict the near future. Methods: We analyzed the time trends of ischemic heart disease mortality, which is on the increase, from 1985 to 2009 using an age-period-cohort model to characterize the effects of ischemic heart disease on changes in the mortality rate over time. Results: All three effects on total ischemic heart disease mortality were statistically significant. Regarding the period effect, the mortality rate was decreased slightly in 2000 to 2004, after it had continuously increased since the late 1980s that trend was similar in both sexes. The expected age effect was noticeable, starting from the mid-60's. In addition, the age effect in women was more remarkable than that in men. Women born from the early 1900s to 1925 observed an increase in ischemic heart mortality. That cohort effect showed significance only in women. Conclusions: The future cohort effect might have a lasting impact on the risk of ischemic heart disease in women with the increasing elderly population, and a national prevention policy is need to establish management of high risk by considering the age-period-cohort effect.

• Journal of Society of Preventive Korean Medicine
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• v.20 no.3
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• pp.31-43
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• 2016

Objectives : It focuses on what the consumers expected Korean medicine to improve on, and analyzes patients' impressions. Methods : This research is based on the Ministry of Health and Welfare's Survey on Usage of Korean Medicine (2008, 2011, and 2014) and was new analysis for our research objective. Results : The general consensus among the consumers was uncertainty of effectiveness, expensive costs, side effects, need for expertise, lack of scientific evidence, expansion of diseases treated, and improvement of equipment. Consumers distrusted Korean medicine due to its uncertainty of its effectiveness, expensive costs, side effects, and lack of scientific evidence for its effectiveness, and avoided using Korean medicine. Conclusions : These results seem to be a combination of the Korean medicinal doctors treating patients not based on evidence but on their individual experiences, lack of health insurance for Korean medicine resulting in expensive costs, lack of research on toxicity and safety of Korean medicine, and lack of scientific and clinical studies for evidence-based research. To solve these problems, the Korean medicine community needs to standardize treatments based on evidence, and look to Chinese medicine for possible solutions.

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.61-65
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• 2008

Although dietary intake of pregnant is supposed to have beneficial effects on development of infants, it may be harmful for fetal growth and development since specific food is a common source of toxicants including heavy metal. The purpose of this study was to investigate the association of maternal food intake and mid-pregnancy and their newborns blood lead levels. Pregnant women of 18-20 weeks of gestation were recruited from prenatal clinic in Seoul, Cheonan and Ulsan. In 422 pregnant women, dietary intake during pregnancy was assessed by a 24-hour recall method. Blood sample from pregnant (18-20 wks) and their cord blood at delivery were collected. Blood leas levels were analyzed by atomic-absorption spectrometry methods. Pregnant blood lead levels whose meat and meat products intake were in the highest quartile was significantly higher compared to the lowest quartile. Maternal meat and meat products intake was positively correlated maternal blood lead level (r=0.120, P=0.014). After adjusting for age, maternal blood lead level was positively correlated with their newborn blood lead level (r=0.303, P=0.030). As maternal food intake effects on blood lead levels of pregnant, careful regulation of food intake during pregnancy is perceives to be important in order to bring about desirable pregnancy outcomes.

• Journal of Preventive Medicine and Public Health
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• v.39 no.5
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• pp.389-396
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• 2006

Objectives: A community-based, cross-sectional survey was conducted to determine theprevalence of osteoporosis and to evaluate the effects of body composition, health behaviors and reproductive history on bone density in postmenopausal women. Methods: The study subjects were 362 postmenopausal women, aged 45 years old or over, who were invited to the hospital. Information on their socio-demographic characteristics and the potential risk factors such as their past medical history, smoking, alcohol intake, exercise, diet and menstrual/reproductive histories were collected by trained interviewers. Weight, height, the body mass index ($kg/m^{2}$), and body composition variables were measured. Bone mineral density of the lumbar spine was measured by dual energy X-ray absorptiometry (DXA). Results: The prevalence of osteoporosis was 30.6% in the $45{\sim}64$ years old women, 52.5% in the elderly women aged $65{\sim}74$, and 68.7% in the women aged 75 years or over. After adjustment for the effect of potential covariates, those women in the highest 25% (4th quartile) of the lean body mass are less likely to have osteoporosis (aOR=0.31, 95% CI=0.12-0.76), compared with the lowest quartile group. More parity also had significantly detrimental effects on osteoporosis. Conclusions: These findings suggest that the prevalence of osteoporosis in postmenopausal women increased with age from 46.3% of those aged 45-64 to 68.7% for those aged 75 and over. Lean body mass and parity appeared significant contributor to bone mineral density in postmenopausal women in this population.

• Journal of Preventive Medicine and Public Health
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• v.40 no.1
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• pp.59-63
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• 2007

Objectives : Nitrogen dioxide $(NO_2)$ has been inconsistently associated with gradual decreases in lung function. Here, we studied the effects of $NO_2$ exposure in asthmatics by examining the association between changes in lung function and concentrations of $NO_2$ which were personally measured. Methods : Peak expiratory flow (PEF) and daily personal exposures to $NO_2$ were recorded on 28 patients with asthma (confirmed by methacholine provocation test) over 4 weeks. We used generalized estimating equations to assess the relationship between personal $NO_2$ exposure and PEF, adjusting for potential confounders such as age, gender, outdoor particulate matter, temperature, humidity, and exposure to environmental tobacco smoke. Results : The personal $NO_2$ exposures were higher than the corresponding ambient levels. The mean personal: ambient ratio for $NO_2$ was 1.48. The personal $NO_2$ exposures were not associated with the morning PEF, evening PEF, or the diurnal PEF variability. However, environmental tobacco smoke was negatively associated with both the morning and evening PEF. Conclusions : Among the asthmatic adults who participated in this study, we found no apparent impact of personal $NO_2$ exposures on the peak expiratory flow.

• Journal of Preventive Medicine and Public Health
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• v.20 no.2 s.22
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• pp.236-246
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• 1987

n-Hexane and benzene are organic compounds which have been widely used as industrial solvents. However, they are also increasingly recognized as important pollutants in working environment. The purpose of this study is tp analyze neurotoxicity of benzene and n-hexane. In this study, tibial nerve of Sprague-Dawley rats were observed after exposing them to two different concentrations of these compounds (6000 ppm of n-hexane and 2000 ppm of benzene) which were known to be the levels to cause subacute toxicity for the three different periods; two weeks, four weeks, and six weeks. The following results were obtained from the analysis of variance, Duncan's multiple comparison test, and regression analysis: 1) Myelin sheath thickness of nerve fiber for two n-hexane exposed groups (four weeks and six weeks) were both reduced compared with the control group and the benzene exposed group. 2) There were positive relationships between nerve fiber diameter and myelin sheath thickness for both exposed and control groups. 3) There was no significant difference in myelin sheath thickness from equal diameter nerve fibers between benzene exposed group and control group, but the greater number of thin myelin sheath were observed for n-hexane exposed group compared with control group. Thus, it is concluded that n-hexane tends to reduce the rate of growth of nerve fiber more than the benzene and control group. While these results shed light on understanding the effects of benzene and n-hexane, the duration of exposure was not long enough to apply these results to real working environments. In addition, to further understand the mechanims of nerve degeneration caused by organic solvents, both epidemiological and biochemical studies should accompanied by this kind of study.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3465-3470
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• 2014

Background: Previous studies have generated conflicting evidence regarding associations between family history and survival after gastric cancer surgery. In this study, we investigated this question using a meta-analysis. Materials and Methods: To identify relevant studies, PubMed and Embase databases were searched up to June 2013. Two reviewers independently assessed search results and data extraction of included studies. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival (OS) were calculated based on fixed- or random-effects models. Homogeneity of effects across studies was assessed using $x^2$ test statistics and quantified by $I^2$. Results: A total of five studies were selected according to the inclusion criteria. The total number of patients included was 2,030, which ranged from 145 to 598 per study. There was no significant difference in OS by family history of cancer (HR=0.83, 95%CIs=0.50-1.38), but subgroup analysis of patients with a first-degree family history of cancer (HR=0.74, 95%CIs=0.60-0.93) and gastric cancer family history (HR=0.56, 95%CIs=0.41-0.76) tended to show better OS in these patients. Conclusions: This meta-analysis suggests that a first-degree family history of cancer or gastric cancer family history is associated with better survival of gastric cancer patients after surgery, after a systematic review of five previous studies. These results can be applied by clinicians when counselling patients regarding their risk of death from gastric cancer. Further study is needed to investigate the underlying mechanism between family history and survival in gastric cancer patients.

• Archives of Pharmacal Research
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• v.29 no.6
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• pp.490-496
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• 2006

This study aimed to evaluate in vitro effects of Rheum undulatum L. root on the development of dental caries, especially its effects on viability, dental plaque formation, and glycolytic acid production of Streptococcus mutans and Streptococcus sobrinus. Methanol extract of Rheum undulatum L. root and its fractions were prepared and tested. Among the test extract and fractions, dichloromethane fraction (DF) showed the most active antibacterial activity (inhibition zone: 13-17 mm) against S. mutans and S. sobrinus in a disc diffusion method. Minimal inhibitory concentrations (MICs) of DF against these bacteria ranged from 0.25 to 0.5 mg/mL. Furthermore, DF significantly inhibited the caries-inducing factors of these bacteria. At sub-MIC levels, DF inhibited in vitro dental plaque formation by S. mutans and S. sobrinus ($IC_{50}$= 0.079 and 0.142 mg/mL, respectively), which was caused, in part, by the inhibitory effect on the activity of glucosyltransferases. A significant reduction of glycolytic acid production was found at the concentration as low as 0.032 mg/mL for S. mutans and 0.063 mg/mL for S. sobrinus. The possible bioactive compounds that are inducing in vitro anti-cariogenic activity of DF are unknown. Based on the preliminary phytochemical analysis, the activity of DF may be related to the presence of anthraquinones, cardiac glycosides, coumarines, sterols/terpenes, and phenolics. These results indicate that DF is probably useful for the control of dental plaque formation and subsequent dental caries development.