• Title, Summary, Keyword: molecular epidemiology

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Expression of Toll-like Receptor 9 Increases with Progression of Cervical Neoplasia in Tunisian Women - A Comparative Analysis of Condyloma, Cervical Intraepithelial Neoplasia and Invasive Carcinoma

  • Fehri, Emna;Ennaifer, Emna;Ardhaoui, Monia;Ouerhani, Kaouther;Laassili, Thalja;Rhouma, Rahima Bel Haj;Guizani, Ikram;Boubaker, Samir
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6145-6150
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    • 2014
  • Toll-like receptors (TLRs) are expressed in immune and tumor cells and recognize pathogen-associated molecular patterns. Cervical cancer (CC) is directly linked to a persistent infection with high risk human papillomaviruses (HR-HPVs) and could be associated with alteration of TLRs expression. TLR9 plays a key role in the recognition of DNA viruses and better understanding of this signaling pathway in CC could lead to the development of novel immunotherapeutic approaches. The present study was undertaken to determine the level of TLR9 expression in cervical neoplasias from Tunisian women with 53 formalin-fixed and paraffin-embedded specimens, including 22 samples of invasive cervical carcinoma (ICC), 18 of cervical intraepithelial neoplasia (CIN), 7 of condyloma and 6 normal cervical tissues as control cases. Quantification of TLR9 expression was based on scoring four degrees of extent and intensity of immunostaining in squamous epithelial cells. TLR9 expression gradually increased from CIN1 (80% weak intensity) to CIN2 (83.3% moderate), CIN3 (57.1% strong) and ICC (100% very strong). It was absent in normal cervical tissue and weak in 71.4% of condyloma. The mean scores of TLR9 expression were compared using the Kruskall-Wallis test and there was a statistical significance between normal tissue and condyloma as well as between condyloma, CINs and ICC. These results suggest that TLR9 may play a role in progression of cervical neoplasia in Tunisian patients and could represent a useful biomarker for malignant transformation of cervical squamous cells.

Association between nutrient intake and thyroid cancer risk in Korean women

  • Cho, Young Ae;Lee, Jeonghee;Kim, Jeongseon
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.336-341
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    • 2016
  • BACKGROUND/OBJECTIVES: The incidence of thyroid cancer has increased in many countries, including Korea. International differences in the incidence of thyroid cancer may indicate a role of diet, but findings from previous studies are inconclusive. Therefore, we aimed to investigate the roles of nutrients in thyroid cancer risk in Korean women. SUBJECTS/METHODS: We conducted a case-control study comprising 113 cases and 226 age-matched controls. Nutrient intake was assessed using a validated food frequency questionnaire, and the association between nutrient intake and thyroid cancer risk was estimated using a logistic regression model. RESULTS: We found that high calcium intake was associated with a reduced risk of thyroid cancer (OR [95% CI] = 0.55 [0.35-0.89]). Significant associations were observed among subjects who were older than 50 years, had low BMI, and had low calorie intake. However, other nutrients included in this study did not show any significant associations with thyroid cancer risk. CONCLUSION: This study suggested a possible protective effect of calcium on thyroid cancer risk. Well-designed prospective studies are required to confirm these findings.

Issues in the Design of Molecular and Genetic Epidemiologic Studies

  • Fowke, Jay H.
    • Journal of Preventive Medicine and Public Health
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    • v.42 no.6
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    • pp.343-348
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    • 2009
  • The final decision of study design in molecular and genetic epidemiology is usually a compromise between the research study aims and a number of logistical and ethical barriers that may limit the feasibility of the study or the interpretation of results. Although biomarker measurements may improve exposure or disease assessments, it is necessary to address the possibility that biomarker measurement inserts additional sources of misclassification and confounding that may lead to inconsistencies across the research literature. Studies targeting multi-causal diseases and investigating gene-environment interactions must not only meet the needs of a traditional epidemiologic study but also the needs of the biomarker investigation. This paper is intended to highlight the major issues that need to be considered when developing an epidemiologic study utilizing biomarkers. These issues covers from molecular and genetic epidemiology (MGE) study designs including cross-sectional, cohort, case-control, clinical trials, nested case-control, and case-only studies to matching the study design to the MGE research goals. This review summarizes logistical barriers and the most common epidemiological study designs most relevant to MGE and describes the strengths and limitations of each approach in the context of common MGE research aims to meet specific MEG objectives.

Molecular Epidemiology of Cryptococcus neoformans/Cryptococcus gattii Complex Isolates from Pigeon Droppings in Korea

  • Chang, Kyungsoo
    • Biomedical Science Letters
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    • v.19 no.3
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    • pp.213-223
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    • 2013
  • The objectives of this study are to develop a molecular diagnosis to differentiate serotypes and mating-types of C. neoformans/C. gattii complex isolates from pigeon droppings in Korea and to elucidate molecular epidemiology of the isolates. Phenotypes and genotypes of C. neoformans/C. gattii complex isolates were identified by biochemical properties and PCR using specific CNLAC1 gene, respectively. To classify serotypes and mating-types of C. neoformans/C. gattii complex isolates, the five reference strains and thirty-three isolates in Korea were investigated by restriction fragment length polymorphism (RFLP) analysis using CNLAC1 gene for varieties, by random amplified polymorphic DNA (RAPD) for serotyping, and by PCR using specific primer sets for mating typing. All isolates in Korea were belonged to C. neoformans var. grubii (serotype A) by RFLP and RAPD patterns which showed high sensitivity and specificity. Therefore, RFLP and RFLP were available to differentiate varieties and serotypes of C. neoformans. Amplification patterns of the five reference strains by specific PCR for mating typing were differentiable, and all isolates were classified into $MAT{\alpha}$. All C. neoformans environmental isolates in Korea were Cr. neoformans serotype A and $MAT{\alpha}$ which is a more virulent pathogen. This study suggests that RFLP and RAPD are rapid and correct molecular diagnosis tools for epidemiology of C. neoformans/C. gattii complex isolates.

Status and Determinants of Health Literacy among Adolescents in Guangdong, China

  • Ye, Xiao-Hua;Yang, Yi;Gao, Yan-Hui;Chen, Si-Dong;Xu, Ya
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8735-8740
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    • 2014
  • Background: Previous studies for non-communicable disease cotrol, including cancer, have mostly relied on health literacy in adults. However, limited studies are available for adolescents. This study aimed to assess the status and determinants of health literacy in in-school adolescents in Guangdong, China. Materials and Methods: A total of 3,821 students aged 13-25 years were selected by multi-stage cluster sampling. After the questionnaire of health literacy was answered, the total scores for health knowledge (18 questions), skills (5 questions) and behaviors (14 questions) were determined. The total scores for health literacy and each subscale were recoded into adequate and inadequate subgroups, and logistic regression models were used to identify factors associated with each outcome variable. Results: The prevalence of adequate health literacy was 14.4%, and the prevalences for adequate knowledge, skills and behavior were 22.4%, 64.7% and 6.6%, respectively. Students coming from prestigious schools and having parents with higher education had higher odds of having adequate knowledge, skills and behaviors. Female students had higher odds of having adequate knowledge and behaviors. Students in grade 7-8 had higher odds of having adequate knowledge and skills. The health knowledge was positive associated with health skills (odds ratio [OR] =2.1, 95% confidence interval [CI] 1.7-2.5) and behaviors (OR=3.0, 95%CI 2.3-4.0), and health skills were positive associated with health behaviors (OR=2.6, 95%CI 1.8-3.8). Conclusions: Further efforts should be made to increase adolescents' health knowledge and behaviors, especially for low grade and male students in non-prestigious schools.

Type-Specific Human Papillomavirus Distribution in Invasive Squamous Cervical Carcinomas in Tunisia and Vaccine Impact

  • Ennaifer, Emna;Salhi, Faten;Laassili, Thalja;Fehri, Emna;Alaya, Nissaf Ben;Guizani, Ikram;Boubaker, Samir
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6769-6772
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    • 2015
  • Background: High risk human papillomaviruses (HPVs) are the leading cause of cervical cancer (CC) and Pap smear screening has not been successful in preventing CC in Tunisia. HPV vaccination that targets HPV16 and 18 offers a new efficient prevention tool. Identification of HPV types in CC is thus essential to determine the impact of HPV vaccine implementation. The aim of this study is to provide specific data from Tunisia. Materials and Methods: A total of 89 histological confirmed paraffin embedded samples isolated from patients with CC diagnosed between 2001 and 2011 were collected from five medical centres from Northern and Southern Tunisia. HPV DNA was detected using a nested PCR (MY09/MY11-GP5+/GP6+) and genotyping was assessed using a reverse blot line hybridisation assay that enables the detection of 32 HPV types. Results: HPV DNA was detected in all samples. Twelve high risk types were detected; HPV16 and/or 18 were predominant, accounting together for 92.1% of all the CC cases (HPV16: 83.1%). Single infections accounted for 48.8% of the cases and were mostly linked to HPV 16 (32.6%) and less frequently to HPV 18 (2.4%). The other high risk HPV single infections were linked to HPV 35 (4.6%), 45 (4.6%), 58 (2.3%) and 59 (2.3%). Multiple infections with mixing of 2 to 4 genotypes predominately featrued HPV16 and/or 18 with HPV 35 and 45 (96.6 %) and less frequently with HPV 59, 40, 66, 73 and 58. There was no statistically significant variation in the relative distribution of HPV types with age. Conclusions: These results strongly indicate that prophylactic HPV vaccines can have a major impact in preventing CC in Tunisia.

Effects of Soy Product Intake and Interleukin Genetic Polymorphisms on Early Gastric Cancer Risk in Korea: A Case-Control Study

  • Yang, Sarah;Park, Yoon;Lee, Jeonghee;Choi, Il Ju;Kim, Young Woo;Ryu, Keun Won;Sung, Joohon;Kim, Jeongseon
    • Cancer Research and Treatment
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    • v.49 no.4
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    • pp.1044-1056
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    • 2017
  • Purpose The current study investigated whether the combined effects of soy intake and genetic polymorphisms of interleukin (IL) genes modify gastric cancer risk. Materials and Methods A total of 377 cases and 754 controls of Korean origin were included in the analysis. Soy consumption was assessed using a semi-quantitative food frequency questionnaire. Seven variants of IL10 (rs1800871), IL2 (rs2069763 and rs2069762), IL13 (rs6596090 and rs20541), and IL4R (rs7205663 and rs1805010) were genetically analyzed. To analyze the combined effect of soy intake and genetic polymorphisms, a low-intake group and high-intake group of each type of soy were categorized based on the intake level of the control group. Interactions between soy products and these genetic variants were analyzed by a likelihood ratio test, in which a multiplicative interaction term was added to the logistic regression model. Results A higher intake of nonfermented soy products was associated with a reduced cancer risk (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.43 to 0.90), and the reduced risk was only apparent in males (OR, 0.44; 95% CI, 0.27 to 0.71). None of the IL genetic polymorphisms examined were independently associated with gastric cancer risk. Individuals with a minor allele of IL2 rs2069762 and a higher intake of nonfermented soy food had a decreased risk of gastric cancer (OR, 0.46; 95% CI, 0.31 to 0.68) compared to those with a lower intake ($p_{interaction}=0.039$). Conclusion Based on the genetic characteristics of the studied individuals, the interaction between IL2 rs2069762 and nonfermented soy intake may modify the risk of gastric cancer.

Molecular epidemiology and virulence changes of infectious hematopoietic necrosis virus (IHNV) in East Asia (동아시아 지역에 있어 전염성조혈기괴사증 바이러스 (IHNV)의 분자역학 및 병독성의 변화)

  • Nishizawa, Toyohiko
    • Journal of fish pathology
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    • v.31 no.1
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    • pp.1-8
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    • 2018
  • Causative agent of infectious hematopoietic necrosis (IHN) belonging to genus Novirhabdovirus (Rhabdoviridae). Economic losses caused by IHNV are serious in mainly Oncorhynchus spp. including rainbow trout O. mykiss and Atrantic salmon Salmo salar. IHNV was initially found by endemic presence in U.S. West Coast for sockeye salmon fry O. nerka and chinook salmon fry O. tshawytscha in the 1950s, and it has spread to Japan, Korea and Taiwan in the 1970s, and also to Italy and France in the 1990s. Currently, IHNV is detectable in many parts of the world, including Russia and South America. Mortality due to IHNV infection in fish with ${\leq}0.5g$ of body weight reaches 60% to 100%, while the mortality reduces by fish growing. In recent years, onset of IHNV infection has increased also in fish with large sizes. Here, we introduce molecular epidemiology and virulence changes of IHNV in East Asia, furthermore, we discuss on future prospects in IHNV researches.

Molecular epidemiology of norovirus in South Korea

  • Lee, Sung-Geun;Cho, Han-Gil;Paik, Soon-Young
    • BMB Reports
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    • v.48 no.2
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    • pp.61-67
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    • 2015
  • Norovirus is a major cause of viral gastroenteritis and a common cause of foodborne and waterborne outbreaks. Norovirus outbreaks are responsible for economic losses, most notably to the public health and food industry field. Norovirus has characteristics such as low infectious dose, prolonged shedding period, strong stability, great diversity, and frequent genome mutations. Besides these characteristics, they are known for rapid and extensive spread in closed settings such as hospitals, hotels, and schools. Norovirus is well known as a major agent of food-poisoning in diverse settings in South Korea. For these reasons, nationwide surveillance for norovirus is active in both clinical and environmental settings in South Korea. Recent studies have reported the emergence of variants and novel recombinants of norovirus. In this review, we summarized studies on the molecular epidemiology and nationwide surveillance of norovirus in South Korea. This review will provide information for vaccine development and prediction of new emerging variants of norovirus in South Korea.