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Gene Detection (gene + detection)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

The skin as a mirror of the ageing process in the human organism , results of the ageing research in the German National Genome Research Network 2

EXPERIMENTAL DERMATOLOGY, Issue 8 2006
CH. C. Zouboulis
Intrinsic human skin ageing is influenced by the individual genetic predisposition and reflects degradation processes of the body. Hormones are decisively involved in intrinsic ageing with reduced secretion of pituitary, adrenal glands, and gonads, which leads to characteristic body and skin phenotypes. A number of advances were recently made in understanding skin ageing mechanisms and major molecular changes, especiallly of the extracellular matrix, were identified. Gene expression patterns compatible with mitotic misregulation and alterations in intracellular transport and metabolism were identified in fibroblasts of ageing humans and humans with progeria. Age-associated changes of extracellular matrix of the skin correlate well with changes been detected in the extracellular matrix of other organs of the human body. Within the National Genome Research Network 2 (NGFN-2) in Germany, the explorative project ,Genetic etiology of human longevity' targets the identification of age-related molecular pathways. For this purpose, skin models of ageing are used. Expression profiling employing cDNA microarrays from known and novel genes and RT-PCR are employed for gene detection and confirmation. Among the potential candidate genes several interesting target genes have been identified. The evaluation of ageing-associated genes in skin models will facilitate the understanding of global molecular ageing mechanisms in the future. [source]

Occurrence and diversity of nitrogen-fixing Sphingomonas bacteria associated with rice plants grown in Brazil

FEMS MICROBIOLOGY LETTERS, Issue 1 2009
Sandy Sampaio Videira
Abstract So far, the occurrence of nitrogen-fixing Sphingomonas bacteria has been restricted to three strains of Sphingomonas azotifigens. In this work, a group of 46 Sphingomonas -like isolates, which originated from two rice varieties grown in two soils in Brazil, were characterized based on morphological, physiological and genetic analyses. The PCR genus specifically applied indicated that all 46 isolates belonged to the Sphingomonas genus and confirmed the results based on the yellow pigment of the colonies grown on potato agar medium and the BIOLOG data. It was also observed that 22 isolates are nitrogen-fixing bacteria as determined by the acetylene reduction method and confirmed by nifH gene detection. The genetic diversity based on the 16S rRNA analysis (amplified rDNA restriction analysis) showed that the isolates formed two distinct groups at a similarity value of 60%. Furthermore, five clusters at 60% similarity were observed with the 16S,23S intergenic space (ribosomal intergenic space analysis) analysis. Sequencing of the 16S rRNA gene and nifH fragments showed that most of the 22 nitrogen-fixing isolates formed clusters apart from that of the S. azotifigens. This is the first report on the occurrence of nitrogen-fixing Sphingomonas bacteria associated with rice grown in Brazil. [source]

Effect of including environmental data in investigations of gene-disease associations in the presence of qualitative interactions

GENETIC EPIDEMIOLOGY, Issue 6 2010
Elizabeth Williamson
Abstract Complex diseases are likely to be caused by the interplay of genetic and environmental factors. Despite this, gene-disease associations are frequently investigated using models that focus solely on a marginal gene effect, ignoring environmental factors entirely. Failing to take into account a gene-environment interaction can weaken the apparent gene-disease association, leading to loss in statistical power and, potentially, inability to identify genuine risk factors. If a gene-environment interaction exists, therefore, a joint analysis allowing the effect of the gene to differ between groups defined by the environmental exposure can have greater statistical power than a marginal gene-disease model. However, environmental data are subject to measurement error. Substantial losses in statistical power for detecting gene-environment interactions can arise from measurement error in the environmental exposure. It is unclear, however, what effect measurement error may have on the power of the joint analysis. We consider the potential benefits, in terms of statistical power, of collecting concurrent environmental data within large cohorts in order to enhance gene detection. We further consider whether these benefits remain in the presence of misclassification in both the gene and the environmental exposure. We find that when an effect of the gene is apparent only in the presence of the environmental exposure, the joint analysis has greater power than a marginal gene-disease analysis. This comparative increase in power remains in the presence of likely levels of misclassification of either the gene or environmental exposure. Genet. Epidemiol. 34:552,560, 2010. © 2010 Wiley-Liss, Inc. [source]

Detecting genotype combinations that increase risk for disease: Maternal-Fetal genotype incompatibility test

GENETIC EPIDEMIOLOGY, Issue 1 2003
Janet S. Sinsheimer
Abstract Biological mechanisms that involve gene-by-environment interactions have been hypothesized to explain susceptibility to complex familial disorders. Current research provides compelling evidence that one environmental factor, which acts prenatally to increase susceptibility, arises from a maternal-fetal genotype incompatibility. Because it is genetic in origin, a maternal-fetal incompatibility is one possible source of an adverse environment that can be detected in genetic analyses and precisely studied, even years after the adverse environment was present. Existing statistical models and tests for gene detection are not optimal or even appropriate for identifying maternal-fetal genotype incompatibility loci that may increase the risk for complex disorders. We describe a new test, the maternal-fetal genotype incompatibility (MFG) test, that can be used with case-parent triad data (affected individuals and their parents) to identify loci for which a maternal-fetal genotype incompatibility increases the risk for disease. The MFG test adapts a log-linear approach for case-parent triads in order to detect maternal-fetal genotype incompatibility at a candidate locus, and allows the incompatibility effects to be estimated separately from direct effects of either the maternal or the child's genotype. Through simulations of two biologically plausible maternal-fetal genotype incompatibility scenarios, we show that the type-I error rate of the MFG test is appropriate, that the estimated parameters are accurate, and that the test is powerful enough to detect a maternal-fetal genotype incompatibility of moderate effect size. Genet Epidemiol 24:1,13, 2003. © 2003 Wiley-Liss, Inc. [source]

Feasibility of COL1A1-PDGFB fusion gene detection to evaluate surgical margins in dermatofibrosarcoma protuberans

THE JOURNAL OF DERMATOLOGY, Issue 7 2009
Masae SHIRAI
No abstract is available for this article. [source]

Fetal RHD genotyping in maternal serum during the first trimester of pregnancy

BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2002
Jean-Marc Costa
Summary., Fetal RHD genotype determination is useful in the management of sensitized RhD-negative pregnant women. It can be ascertained early during pregnancy by chorionic villus sampling (CVS) or amniocentesis. However, these procedures are invasive, resulting both in an increased risk of fetal loss and in an increased severity of immunization due to fetomaternal haemorrhage. A reliable determination of RHD genotype by fetal DNA analysis in maternal serum during the first trimester of pregnancy is reported in this study. One hundred and six sera from RhD-negative pregnant women were obtained during the first trimester of pregnancy. These sera were tested for the presence of RHD gene using a new real-time polymerase chain reaction assay and the results compared with those obtained later in pregnancy on amniotic fluid cells and by RHD serology of the new-born. All sera from women carrying a RhD-positive fetus (n = 62) gave positive results for RHD gene detection and sera from women carrying a RhD-negative fetus (n = 40) were negative. The high level of accuracy of fetal RHD genotyping obtained in this study could enable this technique to be offered on a routine basis for the management of RhD-negative patients during the first trimester of pregnancy. [source]