• Title, Summary, Keyword: epidemiological studies

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Modulation of MnSOD in Cancer: Epidemiological and Experimental Evidences

  • Kim, Ae-Kyong
    • Toxicological Research
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    • v.26 no.2
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    • pp.83-93
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    • 2010
  • Since it was first observed in late 1970s that human cancers often had decreased manganese superoxide dismutase (MnSOD) protein expression and activity, extensive studies have been conducted to verify the association between MnSOD and cancer. Significance of MnSOD as a primary mitochondrial antioxidant enzyme is unquestionable; results from in vitro, in vivo and epidemiological studies are in harmony. On the contrary, studies regarding roles of MnSOD in cancer often report conflicting results. Although putative mechanisms have been proposed to explain how MnSOD regulates cellular proliferation, these mechanisms are not capitulated in epidemiological studies. This review discusses most recent epidemiological and experimental studies that examined the association between MnSOD and cancer, and describes emerging hypotheses of MnSOD as a mitochondrial redox regulatory enzyme and of how altered mitochondrial redox may affect physiology of normal as well as cancer cells.

Digital Epidemiology: Use of Digital Data Collected for Non-epidemiological Purposes in Epidemiological Studies

  • Park, Hyeoun-Ae;Jung, Hyesil;On, Jeongah;Park, Seul Ki;Kang, Hannah
    • Healthcare Informatics Research
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    • v.24 no.4
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    • pp.253-262
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    • 2018
  • Objectives: We reviewed digital epidemiological studies to characterize how researchers are using digital data by topic domain, study purpose, data source, and analytic method. Methods: We reviewed research articles published within the last decade that used digital data to answer epidemiological research questions. Data were abstracted from these articles using a data collection tool that we developed. Finally, we summarized the characteristics of the digital epidemiological studies. Results: We identified six main topic domains: infectious diseases (58.7%), non-communicable diseases (29.4%), mental health and substance use (8.3%), general population behavior (4.6%), environmental, dietary, and lifestyle (4.6%), and vital status (0.9%). We identified four categories for the study purpose: description (22.9%), exploration (34.9%), explanation (27.5%), and prediction and control (14.7%). We identified eight categories for the data sources: web search query (52.3%), social media posts (31.2%), web portal posts (11.9%), webpage access logs (7.3%), images (7.3%), mobile phone network data (1.8%), global positioning system data (1.8%), and others (2.8%). Of these, 50.5% used correlation analyses, 41.3% regression analyses, 25.6% machine learning, and 19.3% descriptive analyses. Conclusions: Digital data collected for non-epidemiological purposes are being used to study health phenomena in a variety of topic domains. Digital epidemiology requires access to large datasets and advanced analytics. Ensuring open access is clearly at odds with the desire to have as little personal data as possible in these large datasets to protect privacy. Establishment of data cooperatives with restricted access may be a solution to this dilemma.

Comparison of Questionnaire Items Used to Evaluate the Level of Occupational and Environmental Exposure in Questionnaires for Epidemiological Studies (국내 주요 역학 연구에서 사용된 설문지의 직업적, 환경적 노출 문항 비교)

  • Lim, Jiyeon;Yoon, Hyung-Suk;Park, Mansuk;Hong, Young Seoub;Lee, Jong-Koo;Oh, Se-Eun;Kang, Daehee;Lee, Kyoung-Mu
    • Journal of Environmental Health Sciences
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    • v.42 no.2
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    • pp.71-84
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    • 2016
  • Objectives: Exposure assessment using questionnaires is effective in large-scale epidemiological studies. However, a limited number of studies have evaluated the questionnaires used in epidemiologic studies in terms of occupational and environmental exposure. The purpose of this study was to summarize and evaluate questionnaire items included in major epidemiological studies conducted in Korea with regard to occupational and environmental exposure. Methods: A total of 12 studies (four cohort studies, six large-scale cross-sectional surveys, and two panel studies) were selected for this study. Various questionnaire items related with occupational and environmental items were collected and summarized into tables. Results: Although job type and address were included in almost all of the studies, the information on occupational or environmental exposure to specific risk factors was collected in a limited number of studies. Moreover, questionnaire items were not standardized, warranting a continuous effort to develop questionnaires and evaluate their validity. Conclusion: Our results suggest that validated questionnaire items focusing on occupational and environmental exposure need to be developed in order to enhance the availability of the information collected from questions in epidemiological studies.

Informed Consent' in Public Health Activities: Based on the Universal Declaration on Bioethics and Human Rights, UNESCO (공중보건 활동에서의 '사전 동의' 문제 - 유네스코 <생명윤리 및 인권에 관한 선언>을 중심으로 -)

  • Meng, Kwang-Ho
    • Journal of Preventive Medicine and Public Health
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    • v.41 no.5
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    • pp.339-344
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    • 2008
  • Objectives : The objective of this paper is to discuss the importance of obtaining informed consent for conducting epidemiological studies and public health activities, based on the Report of the UNESCO's Working Group on Informed Consent. Methods : The Report of the UNESCO's Working Group on Informed Consent was reviewed and discussed in connection with the ethical considerations of public health activities and epidemiological research. Results : It was at the Nuremberg Trial for the German war criminals of the Second World War that the principle of 'consent' was first stated as a consequence of the medical abuses carried out during the War. As a result of the Trial, the Nuremberg Code came out in 1947. Since then, various international declarations or ethical principles on 'informed consent' have been developed and published. These ethical principles on 'informed consent' have mostly to do with the clinical research that involves human subjects, and not with epidemiological studies and public health activities. However, UNESCO recently issued a comprehensive Report on Informed Consent based on the Universal Declaration on Bioethics and Human Rights adopted in 2005, and this included detailed guidelines on informed consent in epidemiological studies and public health activities. Conclusions : Universal Declaration on Bioethics and Human Rights emphasizes the principle of autonomy to protect the human rights of the human subjects involved in any public health activities and epidemiological research. As a practical guideline, obtaining informed consent is strongly recommended.

Linear Mixed Models in Genetic Epidemiological Studies and Applications (선형혼합모형의 역할 및 활용사례: 유전역학 분석을 중심으로)

  • Lim, Jeongmin;Won, Sungho
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.295-308
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    • 2015
  • We have experienced a substantial improvement in and cost-drop for genotyping that enables genetic epidemiological studies with large-scale genetic data. Genome-wide association studies have identified more than ten thousand causal variants. Many statistical methods based on linear mixed models have been developed for various goals such as estimating heritability and identifying disease susceptibility locus. Empirical results also repeatedly stress the importance of linear mixed models. Therefore, we review the statistical methods related with to linear mixed models and illustrate the meaning of their estimates.

Association between Smoking and Mortality: Khon Kaen Cohort Study, Thailand

  • Kamsa-ard, Siriporn;Promthet, Supannee;Lewington, Sarah;Burrett, Julie Ann;Sherliker, Paul;Kamsa-ard, Supot;Wiangnon, Surapon;Parkin, Donald Maxwell
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2643-2647
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    • 2013
  • Background: Despite anti-smoking campaigns, smoking prevalence among Thai males aged 30 or older is high, at around 50%. The purpose of this study was to determine the relationship between smoking and mortality in a rural Thai community. Materials and Methods: Subjects enrolled into the Khon Kaen cohort study between 1990 and 2001 were followed up for their vital status until $16^{th}$ March 2012. The death resource was from the Bureau of Policy and Strategy, Ministry of Interior, Thailand. A Cox proportional hazards model was used to analyse the association between smoking and death, controlling for age, education level and alcohol drinking, and confidence intervals were calculated using the floating risk method. Results: The study recruited 5,962 male subjects, of whom 1,396 died during a median 13.5 years of follow-up. Current smokers were more likely to die than never smokers after controlling for age, education level and alcohol drinking (HR, 95%CI: 1.41, 1.32-1.51), and the excess mortality was greatest for lung cancer (HR, 95%CI: 3.51, 2.65-4.66). However, there was no increased risk with increasing dose of tobacco, and no difference in risk between smokers of yamuan (hand-rolled cigarettes) and manufactured tobacco. Conclusion: Mortality from cancer, particularly lung cancer, and from all causes combined is dependent on smoking status among men in rural Thailand, but the relative risks are lower than have been reported from studies in high income countries, where the tobacco epidemic is more established.

The Literature Study on the Relationship between Tinnitus and Temporomandibular disorder (이명과 악관절장애간의 상호관계 문헌연구)

  • Kim, Bong-Hyun;Nam, Hae-Jeong
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.24 no.3
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    • pp.74-83
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    • 2011
  • Objective : We investigated relationship between tinnitus and temporomandibular disorder(TMD) and tried to find approach possibility in oriental medicine. Method : We searched Pubmed, Scopus, The Cocharane library and additional sources for published and unpublished trials. Search word was "Tinnitus and TMD" Result : We investigated 18 studies. We divided these studies into three parts, epidemiological studies, mechanical studies and treatment studies. In many epidemiological studies. there was significant relationship between tinnitus and TMD. The mechanism was not clear but in recently several studies proposed neurological approach. TMD treatment showed significant improvement in tinnitus accompanied by TMD. Conclusion : In tinnitus accompanied by TMD, TMD treatment can be available to resolve or reduce tinnitus. Especially in oriental medicine acupuncture can be applied to treat this.

Importance of Meta-Analysis and Practical Obstacles in Oncological and Epidemiological Studies: Statistics Very Close but Also Far!

  • Tanriverdi, Ozgur;Yeniceri, Nese
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1303-1306
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    • 2015
  • Studies of epidemiological and prognostic factors are very important for oncology practice. There is a rapidly increasing amount of research and resultant knowledge in the scientific literature. This means that health professionals have major challenges in accessing relevant information and they increasingly require best available evidence to make their clinical decisions. Meta-analyses of prognostic and other epidemiological factors are very practical statistical approaches to define clinically important parameters. However, they also feature many obstacles in terms of data collection, standardization of results from multiple centers, bias, and commentary for intepretation. In this paper, the obstacles of meta-analysis are briefly reviewed, and potential problems with this statistical method are discussed.

Association Between Gestational Diabetes Mellitus and Subsequent Risk of Cancer: a Systematic Review of Epidemiological Studies

  • Tong, Gui-Xian;Cheng, Jing;Chai, Jing;Geng, Qing-Qing;Chen, Peng-Lai;Shen, Xin-Rong;Liang, Han;Wang, De-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.10
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    • pp.4265-4269
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    • 2014
  • Purpose: This study aimed at summarizing epidemiological evidence of the association between gestational diabetes mellitus (GDM) and subsequent risk of cancer. Materials and Methods: We searched Medline, Embase, Cancer Lit and CINAHL for epidemiological studies published by February 1, 2014 examining the risk of cancer in patients with history of GDM using highly inclusive algorithms. Information about first author, year of publication, country of study, study design, cancer sites, sample sizes, attained age of subjects and methods used for determining GDM status were extracted by two researchers and Stata version 11.0 was used to perform the meta-analysis and estimate the pooled effects. Results: A total of 9 articles documented 5 cohort and 4 case-control studies containing 10,630 cancer cases and 14,608 women with a history of GDM were included in this review. Taken together, the pooled odds ratio (OR) between GDM and breast cancer risk was 1.01 (0.87-1.17); yet the same pooled ORs of case-control and cohort studies were 0.87 (0.71-1.06) and 1.25 (1.00-1.56) respectively. There are indications that GDM is strongly associated with higher risk of pancreatic cancer (HR=8.68) and hematologic malignancies (HR=4.53), but no relationships were detected between GDM and other types of cancer. Conclusions: Although GDM increases the risk of certain types of cancer, these results should be interpreted with caution becuase of some methodological flaws. The issue merits added investigation and coordinated efforts between researchers, antenatal clinics and cancer treatment and registration agencies to help attain better understanding.

No Association Between Tea Consumption and Risk of Renal Cell Carcinoma: A Meta-analysis of Epidemiological Studies

  • Hu, Zheng-Hui;Lin, Yi-Wei;Xu, Xin;Chen, Hong;Mao, Ye-Qing;Wu, Jian;Xu, Xiang-Lai;Zhu, Yi;Li, Shi-Qi;Zheng, Xiang-Yi;Xie, Li-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1691-1695
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    • 2013
  • Objective: To evaluate the association between tea consumption and the risk of renal cell carcinoma. Methods: We searched PubMed, Web of Science and Scopus between 1970 and November 2012. Two evaluators independently reviewed and selected articles based on predetermined selection criteria. Results: Twelve epidemiological studies (ten case-control studies and two cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of tea consumption, the overall relative risk (RR) of renal cell carcinoma for the highest level of tea consumption was 1.03 (95% confidence interval [CI] 0.89-1.21). In subgroup meta-analyses by study design, there was no significant association between tea consumption and renal cell carcinoma risk in ten case-control studies using adjusted data (RR=1.08, 95% CI 0.84-1.40). Furthermore, there was no significant association in two cohort studies using adjusted data (RR=0.95, 95% CI 0.81-1.12). Conclusion: Our findings do not support the conclusion that tea consumption is related to decreased risk of renal cell carcinoma. Further prospective cohort studies are required.