• Title/Summary/Keyword: genetic association studies

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Gene-Gene Interaction Analysis for the Accelerated Failure Time Model Using a Unified Model-Based Multifactor Dimensionality Reduction Method

  • Lee, Seungyeoun;Son, Donghee;Yu, Wenbao;Park, Taesung
    • Genomics & Informatics
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    • v.14 no.4
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    • pp.166-172
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    • 2016
  • Although a large number of genetic variants have been identified to be associated with common diseases through genome-wide association studies, there still exits limitations in explaining the missing heritability. One approach to solving this missing heritability problem is to investigate gene-gene interactions, rather than a single-locus approach. For gene-gene interaction analysis, the multifactor dimensionality reduction (MDR) method has been widely applied, since the constructive induction algorithm of MDR efficiently reduces high-order dimensions into one dimension by classifying multi-level genotypes into high- and low-risk groups. The MDR method has been extended to various phenotypes and has been improved to provide a significance test for gene-gene interactions. In this paper, we propose a simple method, called accelerated failure time (AFT) UM-MDR, in which the idea of a unified model-based MDR is extended to the survival phenotype by incorporating AFT-MDR into the classification step. The proposed AFT UM-MDR method is compared with AFT-MDR through simulation studies, and a short discussion is given.

Sequencing and Characterization of Divergent Marbling Levels in the Beef Cattle (Longissimus dorsi Muscle) Transcriptome

  • Chen, Dong;Li, Wufeng;Du, Min;Wu, Meng;Cao, Binghai
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.2
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    • pp.158-165
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    • 2015
  • Marbling is an important trait regarding the quality of beef. Analysis of beef cattle transcriptome and its expression profile data are essential to extend the genetic information resources and would support further studies on beef cattle. RNA sequencing was performed in beef cattle using the Illumina High-Seq2000 platform. Approximately 251.58 million clean reads were generated from a high marbling (H) group and low marbling (L) group. Approximately 80.12% of the 19,994 bovine genes (protein coding) were detected in all samples, and 749 genes exhibited differential expression between the H and L groups based on fold change (>1.5-fold, p<0.05). Multiple gene ontology terms and biological pathways were found significantly enriched among the differentially expressed genes. The transcriptome data will facilitate future functional studies on marbling formation in beef cattle and may be applied to improve breeding programs for cattle and closely related mammals.

TERT rs2736098 Polymorphism and Cancer Risk: Results of a Meta-analysis

  • Qi, Hao-Yu;Zou, Peng;Zhao, Lin;Zhu, Jue;Gu, Ai-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3483-3488
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    • 2012
  • Objective: Several studies have demonstrated associations between the TERT rs2736098 single nucleotide polymorphisms (SNPs) and susceptibility to cancer development. However, there are conflicting results. A systematic meta-analysis was therefore performed to establish the cancer risk associated with the polymorphism. Methods: In this meta-analysis, a total of 6 case-control studies, including 5,567 cases and 6,191 controls, were included. Crude odds ratios with 95% confidence intervals were used to assess the strength of associations in several genetic models. Results: Our results showed no association reaching the level of statistical significance for overall risk. Interestingly, in the stratified analyses (subdivided by ethnicity), significantly increased risks were found in the Asian subgroup which indicates the TERT rs2736098 polymorphism may have controversial involvement in cancer susceptibility. Conclusions: Overall, this meta-analysis indicates that the TERT rs2736098 polymorphism may have little involvement in cancer susceptibility.

The Role of Autophagy in Eosinophilic Airway Inflammation

  • Jinju Lee;Hun Sik Kim
    • IMMUNE NETWORK
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    • v.19 no.1
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    • pp.5.1-5.12
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    • 2019
  • Autophagy is a homeostatic mechanism that discards not only invading pathogens but also damaged organelles and denatured proteins via lysosomal degradation. Increasing evidence suggests a role for autophagy in inflammatory diseases, including infectious diseases, Crohn's disease, cystic fibrosis, and pulmonary hypertension. These studies suggest that modulating autophagy could be a novel therapeutic option for inflammatory diseases. Eosinophils are a major type of inflammatory cell that aggravates airway inflammatory diseases, particularly corticosteroid-resistant inflammation. The eosinophil count is a useful tool for assessing which patients may benefit from inhaled corticosteroid therapy. Recent studies demonstrate that autophagy plays a role in eosinophilic airway inflammatory diseases by promoting airway remodeling and loss of function. Genetic variant in the autophagy gene ATG5 is associated with asthma pathogenesis, and autophagy regulates apoptotic pathways in epithelial cells in individuals with chronic obstructive pulmonary disease. Moreover, autophagy dysfunction leads to severe inflammation, especially eosinophilic inflammation, in chronic rhinosinusitis. However, the mechanism underlying autophagy-mediated regulation of eosinophilic airway inflammation remains unclear. The aim of this review is to provide a general overview of the role of autophagy in eosinophilic airway inflammation. We also suggest that autophagy may be a new therapeutic target for airway inflammation, including that mediated by eosinophils.

Association between the HSPA1B ±1267A/G Polymorphism and Cancer Risk: a Meta-analysis of 14 Case-Control Studies

  • Kuang, Dan;Chen, Wei;Song, Yue-Zhang;Yu, Yan-Yan;Zhang, Dong-Ying;Wu, Lang;Tang, Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6855-6861
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    • 2014
  • Background: Previous epidemiological studies have suggested a potential role of the $HSPA1B{\pm}1267A/G$ polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk. Materials and Methods: We retrieved relevant articles from PubMed, EMBASE, ISI Web of Science, Chinese Biomedical Literature and Chinese National Knowledge Infrastructure. Studies were selected using specific criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess those associations. All analyses were performed using STATA software. Results: Fourteen case-control studies, including 1, 834 cancer cases and 2, 028 controls were included in this meta-analysis. Overall, the results indicated that the G allele of HSPA1B gene ${\pm}1267A/G$ was significantly associated with an increased cancer risk in all genetic models (G vs A: OR=1.51, 95%CI 1.17-1.95, p=0.001; GG vs AA: OR=2.93, 95%CI 1.50-5.74, p=0.002; AG vs AA: OR=1.48, 95%CI 1.10-1.98, p=0.009; GG/AG vs AA: OR=1.69, 95%CI 1.22-2.33, p=0.001; GG vs AG/AA: OR=2.31, 95%CI 1.24-4.32, p=0.009). In the subgroup analysis stratified by ethnicity, a significant association was identified in Caucasians (G vs A: OR=1.35, 95%CI 1.08-1.69, p=0.008; GG/AG vs AA: OR=1.36, 95%CI 1.09-1.70, p=0.007), but not in Asians. In the stratified analysis by cancer types, individuals with the G allele showed an increased risk of hepatocellular carcinoma compared with carriers of the A allele (OR=2.40, 95%CI 1.47-3.91, p<0.001). Inversely, individuals with the GG genotype showed a decreased risk of gastric cancer compared with carriers of the AG/GG genotypes (GG vs AG/AA: OR=0.39, 95%CI 0.20-0.70, p=0.007). Conclusions: This meta-analysis suggests associations between the HSPA1B ${\pm}1267A/G$ polymorphism and risk of cancer. However, this association might be Caucasian-specific and the G allele of this polymorphism probably increases risk of hepatocellular carcinoma while decreasing risk of gastric cancer. Further well-designed studies based on larger sample sizes are needed to validate these findings.

Mouse Models of Gastric Carcinogenesis

  • Yu, Sungsook;Yang, Mijeong;Nam, Ki Taek
    • Journal of Gastric Cancer
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    • v.14 no.2
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    • pp.67-86
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    • 2014
  • Gastric cancer is one of the most common cancers in the world. Animal models have been used to elucidate the details of the molecular mechanisms of various cancers. However, most inbred strains of mice have resistance to gastric carcinogenesis. Helicobacter infection and carcinogen treatment have been used to establish mouse models that exhibit phenotypes similar to those of human gastric cancer. A large number of transgenic and knockout mouse models of gastric cancer have been developed using genetic engineering. A combination of carcinogens and gene manipulation has been applied to facilitate development of advanced gastric cancer; however, it is rare for mouse models of gastric cancer to show aggressive, metastatic phenotypes required for preclinical studies. Here, we review current mouse models of gastric carcinogenesis and provide our perspectives on future developments in this field.

TRANSMISSION OF C-BAND VARIANTS IN JAPANESE QUAIL

  • Sohn, S.H.;Fechheimer, N.S.;Nestor, K.E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.2
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    • pp.171-174
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    • 1995
  • Heteromorphisms of chromosome banding patterns can be useful markers for gene mapping and other kinds of genetic studies. In Japanese quail, the centromere region of chromosome No. 4 is the site of a heteromorphism. One form of the C-band at this region is relatively small ("a" form); an alternative form is much larger ("b" form). To identify the transmission patterns, all possible matings were made between birds with karyotype a/a, a/b, and b/b. The outcome from all crosses are entirely consistent with the expectation from simple Mendelian transmission. No evidence was found for segregation distortion or gametic selection. This dimorphism, therefore, is a reliable marker.

Crop-Animal Production Systems in Tropical Regions - Review -

  • Devendra, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.2
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    • pp.265-276
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    • 2000
  • Crop-animal systems which form the backbone of agriculture in the tropics are discussed with reference to their characteristics, economic importance of animals, genesis and types of crop-animal systems, relevance and potential importance, and priorities for research and development. These production systems are found across all agroecological zones: rain-fed temperate and highland systems, semi-arid and arid tropics, and sub-humid and humid tropics: the last four are priority areas in Asia. The potential importance of these systems in Asia is reflected in their advantages, synergism and complimentarity, economic benefits and contribution to sustainability. Illustrative case studies are cited which are appropriate to the two broad types of mixed farming systems: systems combining animals and annual cropping, and systems combining animals with perennial cropping with reference to Indonesia, Philippines, Malaysia, Sri Lanka, China and Nigeria. Priorities for research and development should address more complete use of the animal genetic resources, intensive utilisation of the feed resources, development-oriented utilisation of research results, minimizing animal diseases, and implementation of appropriate institutional and policy issues.

Growth Hormone Therapy in Adults with Prader-Willi Syndrome

  • Cho, Sung Yoon
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.1 no.2
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    • pp.49-53
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    • 2015
  • Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder characterized by hypothalamic-pituitary dysfunction. Many features of PWS indicate a deficiency in growth hormone (GH) production, and these findings provide a rationale for GH therapy in PWS. It is possible that rhGH therapy could have beneficial effects in adults with PWS, similar to those in adults with GH deficiency (GHD) of non-syndromic cause. However, there is a paucity of data on the use of GH in adults with PWS. Here, the previous studies about efficacy and safety of rhGH therapy in PWS adults are summarized. Briefly, rhGH therapy in PWS adults may improve body composition, leading to increased lean body mass and decreased fat mass, as well as decreased subcutaneous and visceral adiposity without overall changes in body mass index. There may be at least transient deterioration in glucose homoeostasis in some PWS patients on rhGH therapy, which requires further study. In addition, clinical care guidelines for rhGH therapy in adults with PWS were suggested.

Tetra Primer ARMS PCR Optimization to Detect Single Nucleotide Polymorphisms of the CYP2E1 Gene

  • Suhda, Saihas;Paramita, Dewi Kartikawati;Fachiroh, Jajah
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3065-3069
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    • 2016
  • Single nucleotide polymorphism (SNP) detection has been used extensively for genetic association studies of diseases including cancer. For mass, yet accurate and more economic SNP detection we have optimized tetra primer amplification refractory mutation system polymerase chain reaction (ARMS PCR) to detect three SNPs in the cytochrome P450 2E1 (CYP2E1) gene locus; i.e. rs3813865, rs2070672 and rs3813867. The optimization system strategies used were (1) designing inner and outer primers; (2) determining of their optimum primer concentration ratios; and (3) determining of the optimum PCR annealing temperature. The tetra primer ARMS PCR result could be directly observed using agarose gel electrophoresis. The method succesfully determined three SNPs in CYP2E1 locus, the results being consistent with validation using DNA sequencing and restriction fragment length polymorphisms (RFLP).