• Journal of Environmental Health Sciences
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• v.40 no.4
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• pp.265-278
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• 2014

Microbes such as bacteria, fungi, archaea, protists, and viruses are ubiquitous and people are exposed to them continuously. Endotoxin is a component of the outer membrane of Gram-negative bacteria and a potent proinflammaotry substance. When a person is exposed to environmental endotoxin, an innate immune response is initiated upon the initial recognition and this response produces various inflammatory mediators and recruits inflammatory cells to the exposed tissues. A purified chemical form of endotoxin is called lipopolysaccharide (LPS), and the lipid A portion of the molecule is a biologically active moiety. Exposure to endotoxin may result in various complex health effects depending on time, route, and dose of exposure, as well as host susceptibility. Gene-environment interactions play important roles in health effects of endotoxin exposure, e.g. development or aggravation of asthma. To accurately assess exposure to endotoxin in environmental or epidemiologic studies, methods of sampling, extraction, and analysis must be carefully selected since the selected methods may substantially affect analytical results and there is no internationally-agreed standard method to date. The lack of a standardized method hampers the establishment of exposure-response relationships. While an internationally-agreed health-based exposure limit does not exist, the Dutch Expert Committee on Occupational Safety recently recommended $90EU/m^3$ as a health-based occupational exposure limit. The current article reviews various scientific issues on how we measure environmental endotoxin and the health effects of endotoxin exposure.

• Journal of Oral Medicine and Pain
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• v.39 no.3
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• pp.107-114
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• 2014

Purpose: This study want to draw conclusion based on data taken from national health insurance and determined the distribution and direction of patients treated at private clinics. Methods: The author's research spanned and compared the nationally insured patients by sexes, diagnoses, age groups and cases per year (2005, 2009, and 2013). Subjects were 3,536 patients of a private clinic in Seoul that were covered under national insurance. Results: There was no disparity across sexes nor cases, but both were on the decline. The most common dental conditions were pulpitis and dental caries at 38.4% and 16.4%, respectively. Both have decreased. Despite a drop in overall patients, the percentage of patients under 10 years old jumped substantially. Of overall age groups, teens were most prevalent at 33.5%, second and third being those in their forties and fifties (14.2% and 12.0%, respectively). Conclusions: The major illnesses that plague patients are pulpitis, dental caries, eruption disorder, gingivitis and periodontitis: the wane of pulpitis cases (a considerable percentage) and the actual numbers of patients has contributed to the general decrease in cases.

• Toxicological Research
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• v.32 no.1
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• pp.21-33
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• 2016

Dichlorodiphenyltrichloroethane (DDT) is still used in certain areas of tropics and subtropics to control malaria and other insect-transmitted diseases. DDT and its metabolites have been extensively studied for their toxicity and carcinogenicity in animals and humans and shown to have an endocrine disrupting potential affecting reproductive system although the effects may vary among animal species in correlation with exposure levels. Epidemiologic studies revealed either positive or negative associations between exposure to DDT and tumor development, but there has been no clear evidence that DDT causes cancer in humans. In experimental animals, tumor induction by DDT has been shown in the liver, lung, and adrenals. The mechanisms of hepatic tumor development by DDT have been studied in rats and mice. DDT is known as a non-genotoxic hepatocarcinogen and has been shown to induce microsomal enzymes through activation of constitutive androstane receptor (CAR) and to inhibit gap junctional intercellular communication (GJIC) in the rodent liver. The results from our previously conducted 4-week and 2-year feeding studies of p,p'-DDT in F344 rats indicate that DDT may induce hepatocellular eosinophilic foci as a result of oxidative DNA damage and leads them to hepatic neoplasia in combination with its mitogenic activity and inhibitory effect on GJIC. Oxidative stress could be a key factor in hepatocarcinogenesis by DDT.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.170-179
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• 1994

Atherosclerosis, a multifactorial disease, is closely related to lipid nutrition , Data from well known epidemiological studies including Seven Country , Framinghsam Study and several intervention trials have confirmed that serum cholesterol is the major risk factor and elevation of LDL-cholesterol level is most undesriable. On the basis of results concurring in that dietary saturated fat and cholesterol increase serum cholesterol while polyunsaturated fat decrease it, changes in serum choesterol level have been predicted by regression equations developed by Keys et al. and other investigators. Effects of individual fatty acids on the level of serum cholesterol have been further differentiated by chain length, cis-trans isomers and n-6 vs n-3 polyunsaturated fatty acids. Among them the effect of n-3 fatty acids has been well recogniaed as antiplatelet activity, thus reducing the incidence of atherosclerosis. Role of vitamin E in prevention of atherosclerosis has been evovled from works showing that LDL oxdiation stimulates formation of ateroma and also from epidemiologic studies. Dietary recommendations at present are : (ⅰ) 30 and 10 cal % as upper limit of total and saturated fat intakes, respectively (ⅱ) no more than 300 mg cholesterol/day, (ⅲ) 1-2 g of n-3 fatty acid/day and (ⅳ) some increase RDA of vitamin E which is 8-10 TE.

• Journal of Acupuncture Research
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• v.18 no.5
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• pp.164-178
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• 2001

Objective : To research the trends of the study related to bee venom and arthritis, and to establish the hereafter direction of the study on bee venom herval acupuncture. Method : We searched in PubMed, with bee venom and arthritis (with abstract). Results : 1. We searched15 Papers, and the pattern of the was as fallows: Experimental study(13 Papers), Epidemiologic study(2), Review study(1). 2. The type of the experimental studies(12 Papers) was as follows: In vivo(6 Paper), In vitro(6). And the involved components of bee venom were as follows: Bee venom itself(6 Papers), Melittin(3), PLAP(1), PLAP & Melittin(1), Adolapin(1). 3. Among the experimental studies(12 Papers), the mechanism of inflammation was 10 papers (Inhibition 7, Inducer 3), and the effect of bee venom herbal acupuncture therapy were 2 papers.

• Journal of Oral Medicine and Pain
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• v.43 no.3
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• pp.61-69
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• 2018

Obstructive sleep apnea (OSA) is a relatively common, but greatly underdiagnosed sleep-related breathing disorder, characterized by recurrent collapse of the upper airway during sleep. OSA has been associated with a variety of cardiometabolic disease, such as hypertension, coronary artery disease, cardiac arrhythmia, cerebrovascular disease and metabolic dysfunction. Neurocognitive impairment, including excessive daytime sleepiness, increased risk of motor vehicle accidents, is also related to OSA. Sleep fragmentation and related arousals during sleep lead to intermittent hypoxia, sympathetic activation, oxidative stress, systemic inflammation and metabolic dysregulation which provide biological plausibility to this pathologic mechanism. Extensive studies demonstrated that OSA is a modifiable risk factor for the above mentioned diseases and oral appliances (OAs), although continuous positive air pressure (CPAP) is a first-line therapy of OSA, are not inferior to CPAP at least in mild OSA, and may be an alternative to CPAP in CPAP-intolerant subjects with OSA. The goal of this article is to provide a current knowledge of pathologic link between OSA and cardiovascular disease, focusing on intermittent hypoxia, sympathetic activation, oxidative stress and metabolic dysregulation. Then, previous epidemiologic studies will be reviewed to understand the causal relationship between OSA and cardiovascular disease. Finally, the effects of OAs will be updated via recent metaanalyses compared to CPAP.

• Journal of Preventive Medicine and Public Health
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• v.40 no.2
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• pp.95-101
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• 2007

Focusing on complex diseases of public health significance, strategic issues regarding the on-going Korean Genome Cohort were reviewed: target size and diseases, measurements, study design issues, and follow-up strategy of the cohort. Considering the epidemiologic characteristics of Korean population as well as strengths and drawbacks of current research environment, we tried to tailor the experience of other existing cohorts into proposals for this Korean study. Currently 100,000 individuals have been participating the new Genome Cohort in Korea. Target size of de novo collection is recommended to be set as between 300,000 to 500,000. This target size would allow acceptable power to detect genetic and environmental factors of moderate effect size and possible interactions between them. Family units and/or special subgroups are recommended to parallel main body of adult individuals to increase the overall efficiency of the study. Given that response rate to the conventional re-contact method may not be satisfactory, successful follow-up is the main key to the achievement of the Korean Genome Cohort. Access to the central database such as National Health Insurance data can provide enormous potential for near-complete case detection. Efforts to build consensus amongst scientists from broad fields and stakeholders are crucial to unleash the centralized database as well as to refine the commitment of this national project.

• Journal of Gastric Cancer
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• v.18 no.4
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• pp.328-338
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• 2018

The incidence of gastroesophageal junction adenocarcinoma (GEJAC) in Western countries has increased in recent decades, in addition to a rise in the incidence of esophageal adenocarcinoma (EAC). Gastroesophageal reflux disease (GERD), obesity, smoking, alcohol consumption, and low Helicobacter pylori (HP) infection rate have been nominated as risk factors for such cancers. Among these risk factors, the increased prevalence of GERD and obesity and the decreased prevalence of HP infection are of special interest owing to the currently increasing prevalence of GEJAC in Western countries. Although similar trends in the prevalence of GERD, obesity, and HP infection are observed in Asian countries after a time lag from Western countries, it is still uncertain if the prevalence of GEJAC in Asian countries is increasing, especially in Korea. The incidence of GERD in Korea is currently increasing; it was below 3% in the 1990s. The incidence of obesity in the Korean population is increasing owing to the adoption of westernized lifestyles, including food preferences, and the HP infection rate in Korea is known to be decreasing. Therefore, based on logical extrapolation of observations of Western countries, the incidence of GEJAC will increase in Korea. However, the proportion of GEJAC among other upper gastrointestinal malignancies in Korea appears to be currently unchanged compared with that in the 1990s. Presently, there is a lack of epidemiologic studies on this issue in this region; therefore, more studies are needed to clarify the characteristics of these tumors and to improve clinical outcomes for patients with these tumors.

• Safety and Health at Work
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• v.12 no.2
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• pp.174-183
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• 2021

Background: Toluene diisocyanate (TDI) is a highly reactive chemical that causes sensitization and has also been associated with increased lung cancer. A risk assessment was conducted based on occupational epidemiologic estimates for several health outcomes. Methods: Exposure and outcome details were extracted from published studies and a NIOSH Health Hazard Evaluation for new onset asthma, pulmonary function measurements, symptom prevalence, and mortality from lung cancer and respiratory disease. Summary exposure-response estimates were calculated taking into account relative precision and possible survivor selection effects. Attributable incidence of sensitization was estimated as were annual proportional losses of pulmonary function. Excess lifetime risks and benchmark doses were calculated. Results: Respiratory outcomes exhibited strong survivor bias. Asthma/sensitization exposure response decreased with increasing facility-average TDI air concentration as did TDI-associated pulmonary impairment. In a mortality cohort where mean employment duration was less than 1 year, survivor bias pre-empted estimation of lung cancer and respiratory disease exposure response. Conclusion: Controlling for survivor bias and assuming a linear dose-response with facility-average TDI concentrations, excess lifetime risks exceeding one per thousand occurred at about 2 ppt TDI for sensitization and respiratory impairment. Under alternate assumptions regarding stationary and cumulative effects, one per thousand excess risks were estimated at TDI concentrations of 10 - 30 ppt. The unexplained reported excess mortality from lung cancer and other lung diseases, if attributable to TDI or associated emissions, could represent a lifetime risk comparable to that of sensitization.

• Journal of Korean Academy of Nursing
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• v.52 no.4
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• pp.451-463
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• 2022

Purpose: This study examined the reciprocal relationships between depression and income, and gender differences in these relationships among older adults in South Korea. Methods: Using 2015 to 2019 of the Korea Welfare Panel Study (KoWePS), we studied 6,070 older adults (2,394 men and 3,676 women) aged 60 years over in 2015. The generalized estimating equation was employed to explore the effect of an individual income on depression and the reverse causal link-that of depression on income. Results: The study found the reciprocal relationships between income and depression. Income has a significant impact on depression. Higher-income was linked to decreased risks of the Center for Epidemiologic Studies Depression (CES-D) scores among older adults (B = - 0.121, p < 0.001). Estimates of the reverse causal link show that higher CES-D scores were also linked to income reduction among Korean older adults (B = - 0.007, p < 0.001). In addition, we also observed gender differences in the impact of income on depression but not in the reverse causal link. Income has more detrimental to psychological consequence for older men (B = - 0.108, p < 0.001) than older women (B = - 0.057, p < 0.001). Conclusion: The finding implies that both psychological and social protection policies for the elderly are needed in view of gender perspective.