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Polymorphism Site (polymorphism + site)
Selected AbstractsNeurocognitive variation in smoking behavior and withdrawal: genetic and affective moderatorsGENES, BRAIN AND BEHAVIOR, Issue 1 2009D. E. Evans A burgeoning literature suggests that attentional factors are associated with smoking behavior (e.g. direct nicotine effects and smoking withdrawal). This study examined differences in attentional processing between nonsmokers, satiated smokers and overnight nicotine-deprived smokers by comparing the amplitude of the P300 (P3) component of the event-related brain potential (ERP) elicited during a go,nogo task. We also examined the moderating effects of a common dopamine receptor genotype and state negative affect (SNA) on this ERP index of attention. Nonsmokers relative to smokers had greater nogo P3 amplitude. Carrying the A1 allele at the dopamine receptor D2 (DRD2) Taq1A polymorphism site moderated the effects of withdrawal on nogo P3 amplitude, suggesting the A1 allele is a vulnerability marker for withdrawal-related attentional deficits. Increased SNA also predicted attenuated P3 amplitude among deprived smokers. These findings suggest that DRD2 status and SNA moderate the effects of smoking status and withdrawal on neurocognitive variation during attentional processing. This research contributes to a better understanding of the role of individual differences and attentional processing in smoking behavior. [source] Association of CTLA-4 gene polymorphism with oral submucous fibrosis in TaiwanJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 4 2004Yi-Ning Shin Background:, Oral submucous fibrosis (OSF) is an insidious, pre-cancerous, chronic disease that may affect the entire oral cavity and sometimes extend to the pharynx. It has been reported to be associated with immune function. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4; CD (cluster of differentiation) 152) is a negative regulator of T-lymphocyte activation. Particular genotypes of the locus encoding the CTLA-4 glycoprotein have been associated with susceptibility to various autoimmune diseases. This study was designed to investigate the role of CTLA-4 polymorphism in susceptibility to OSF. Methods:, We genotyped 62 patients with OSF and 147 healthy controls for allelic determinants at the exon 1 +49 polymorphism site by restriction fragment length polymorphism. Genotype and phenotype frequencies were evaluated with Chi-squared test. Results:, The G allele at position +49 of exon 1 was significantly associated with OSF. The frequency of A/A homozygotes was higher in controls than in patients (17.0% vs. 3.2%; ,2 = 7.65, P = 0.02); the G phenotype was more frequent in patients than in controls (96.8% vs. 83.0%; ,2 = 9.31, P = 0.002). Compared with controls, the G allele genotype and phenotype frequencies were increased in patients with OSF. Conclusion:, This is the first report that the CTLA-4 +49 G allele confers an increased risk of OSF in Taiwan. [source] Association of vitamin D receptor gene polymorphisms in Chinese patients with generalized aggressive periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 3 2008S. Li Background and Objective:, The clinical features suggest that genetic factors may have a strong influence on susceptibility to aggressive periodontitis. The aim of this study was to investigate the association of vitamin D receptor gene polymorphisms with generalized aggressive periodontitis in Chinese patients. Material and Methods:, A restriction fragment length polymorphism (RFLP) for 10,438,141 C to T (rs1544410, BsmI), 10,382,063 A to G (rs731236, TaqI), 10,382,143 C to A (rs7975232, ApaI) and 10,416,201 A to G (rs2228570, FokI) of vitamin D receptor gene was analysed by polymerase chain reaction, followed by digestion with restriction enzymes and gel electrophoresis. The genotypes of 51 generalized aggressive periodontitis patients and 53 periodontally healthy control subjects were analysed. The genotypic and allelic frequencies of each polymorphism site for the patients and control subjects were compared. Results:, The distribution of vitamin D receptor FokI genotypes and alleles between the two groups was significantly different (p = 0.043 and p = 0.012, respectively). The F allele seemed to increase the susceptibility of aggressive periodontitis (odds ratio = 2.02, 95% confidence interval = 1.16,3.50) in Chinese patients. There was no significant difference in the genotype distribution or the allele frequencies of vitamin D receptor BsmI, ApaI and TaqI between two groups. Conclusion:, The study indicates that FokI polymorphism of vitamin D receptor gene might be associated with generalized aggressive periodontitis in Chinese patients. In addition, the carriage of F allele increases the risk of developing generalized aggressive periodontitis. [source] Putative association of a TLR9 promoter polymorphism with atopic eczemaALLERGY, Issue 7 2007N. Novak Background:, Toll-like receptors (TLR) play a pivotal role in the induction of first-line defense mechanisms of the innate immune system and trigger adaptive immune responses to microbial pathogens. Genetic variations in innate immunity genes have been reported to be associated with a range of inflammatory disorders. Deficiencies on the level of immunity receptors such as pathogen-recognition receptors are suspected to affect the maturation of our immune system and to avail thereby the high prevalence of atopic diseases and susceptibility of atopic patients to microbial infections. Aims of the study:, We evaluated TLR9 as susceptibility gene for atopic eczema (AE). Methods:, Analyses of four tag single-nucleotide polymorphisms in two panels of families containing a total of 483 parent-affected offspring trios as well as a cohort of 274 unrelated adult AE cases and 252 hypernormal population-based controls have been performed. Results:, In both family cohorts, polymorphism C-1237T, which is located within the promoter region of the TLR9 gene, was significantly associated with AE, in particular the intrinsic subtype of AE. No associations were seen in the case,control cohort. Luciferase reporter gene assays revealed significantly higher promoter activity of the TT allelic variant at this single nucleotide polymorphism site. Conclusion:, These observations suggest that the TLR9 promoter polymorphism C-1237T might affect AE susceptibility in particular in patients with the intrinsic variant of AE. [source] ,-Interferons and the single nucleotide polymorphisms: A milestone to tailor-made therapy for chronic hepatitis CHEPATOLOGY RESEARCH, Issue 5 2010Yasuhito Tanaka Type III interferons (IFN) (IFN-,1, -,2, -,3/interleukin [IL]-29, -28A, -28B) are cytokines with type I IFN-like antiviral activities. Most cells have expressed both type I and III IFN following Toll-like receptor (TLR) stimulation or viral infection, whereas the ability of cells to respond to IFN-, was restricted to a specific subset of cells. It was reported that signal transduction pathway of IFN-, was similar to that of IFN-,/, although a receptor adapted by IFN-, were distinct from that of IFN-,/,. However, the clinical significance and the role of each IFN-, were unclear. Recent genome-wide association studies (GWAS) of the human whole genome revealed several single nucleotide polymorphism sites (SNP) strongly associated with the response to pegylated IFN-, (PEG-IFN) plus ribavirin (RBV) treatment in chronic hepatitis C patients. The SNP, which are located near the IL-28B gene of chromosome 19, were discovered simultaneously by three independent studies opening a new prospective in hepatitis C research. The present review highlights significant insights that can be derived from the GWAS approach, and summarizes current knowledge of in vitro and in vivo study on the role of IFN-, in antiviral effect. [source] Inferences from DNA data: population histories, evolutionary processes and forensic match probabilitiesJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 2 2003Ian J. Wilson Summary. We develop a flexible class of Metropolis,Hastings algorithms for drawing inferences about population histories and mutation rates from deoxyribonucleic acid (DNA) sequence data. Match probabilities for use in forensic identification are also obtained, which is particularly useful for mitochondrial DNA profiles. Our data augmentation approach, in which the ancestral DNA data are inferred at each node of the genealogical tree, simplifies likelihood calculations and permits a wide class of mutation models to be employed, so that many different types of DNA sequence data can be analysed within our framework. Moreover, simpler likelihood calculations imply greater freedom for generating tree proposals, so that algorithms with good mixing properties can be implemented. We incorporate the effects of demography by means of simple mechanisms for changes in population size and structure, and we estimate the corresponding demographic parameters, but we do not here allow for the effects of either recombination or selection. We illustrate our methods by application to four human DNA data sets, consisting of DNA sequences, short tandem repeat loci, single-nucleotide polymorphism sites and insertion sites. Two of the data sets are drawn from the male-specific Y-chromosome, one from maternally inherited mitochondrial DNA and one from the , -globin locus on chromosome 11. [source] Three nuclear genes for phylogenetic, SNP and population genetic studies of molluscs and other invertebratesMOLECULAR ECOLOGY RESOURCES, Issue 1 2010A. AUDZIJONYTE Abstract The study reports new primers capable of amplifying fragments from three nuclear protein-coding genes in a variety of deep-sea molluscs and annelids , adenine nucleotide translocase (Ant), calmodulin (Cal) and cyclophilin A (CycA). The Ant primers appear to be restricted to bivalve molluscs, whereas the Cal and CycA primers also amplified appropriate gene fragments from Lepetodrilus gastropod molluscs and Osedax polychaete worms. The amplified fragment of Cal contains an intron in the molluscs, but no intron was detected in the Ant and CycA fragments from any of the tested animals. DNA sequences generated by the three primer sets exhibited one to 15 single nucleotide polymorphism sites in deep-sea vesicomyid clams and Osedax boneworms. The observed levels of polymorphism indicate that the genes are likely to be useful in both population genetic and phylogenetic analyses of different invertebrate taxa. [source] | |||||||||||||