Search results for "ROSAT"
showing 10 items of 520 documents
Fine-scale spatial genetic structure analysis of the black truffle T uber aestivum and its link to aroma variability
2015
Truffles are symbiotic fungi in high demand by food connoisseurs. Improving yield and product quality requires a better understanding of truffle genetics and aroma biosynthesis. One aim here was to investigate the diversity and fine-scale spatial genetic structure of the Burgundy truffle Tuber aestivum. The second aim was to assess how genetic structuring along with fruiting body maturation and geographical origin influenced single constituents of truffle aroma. A total of 39 Burgundy truffles collected in two orchards were characterized in terms of aroma profile (SPME-GC/MS) and genotype (microsatellites). A moderate genetic differentiation was observed between the populations of the two o…
Data from: Fine-scale spatial genetic dynamics over the life-cycle of the tropical tree Prunus africana
2014
Studying fine-scale spatial genetic patterns across life stages is a powerful approach to identify ecological processes acting within tree populations. We investigated spatial genetic dynamics across five life stages in the insect-pollinated and vertebrate-dispersed tropical tree Prunus africana in Kakamega Forest, Kenya. Using six highly polymorphic microsatellite loci, we assessed genetic diversity and spatial genetic structure (SGS) from seed rain and seedlings, and different sapling stages to adult trees. We found significant SGS in all stages, potentially caused by limited seed dispersal and high recruitment rates in areas with high light availability. SGS decreased from seed and early…
Host-based divergence in populations of the pea aphid: insights from nuclear markers and the prevalence of facultative symbionts.
2003
In North America, the pea aphid Acyrthosiphon pisum encompasses ecologically and genetically distinct host races that offer an ideal biological system for studies on sympatric speciation. In addition to its obligate symbiont Buchnera, pea aphids harbour several facultative and phylogenetically distant symbionts. We explored the relationships between host races of A. pisum and their symbiotic microbiota to gain insights into the historical process of ecological specialization and symbiotic acquisition in this aphid. We used allozyme and microsatellite markers to analyse the extent of genetic differentiation between populations of A. pisum on pea, alfalfa and clover in France. In parallel, we…
Colonoscopy and reduction of colorectal cancer risk by molecular tumor subtypes: a population-based case-control study
2020
AbstractObjectiveIn previous studies, the protective effect of colonoscopy was generally stronger for distal than for proximal colorectal cancer (CRC). This study aimed to investigate whether the association of colonoscopy and CRC risk varies according to major molecular pathological features and pathways of CRC.DesignPopulation-based case-control study from Germany, including 2132 patients with a first diagnosis of CRC and information on major molecular tumor markers, and 2486 control participants without CRC. Detailed participant characteristics were collected by standardized questionnaires and information on previous colonoscopy was derived from medical records. Polytomous logistic regre…
Genetic variation and urine cadmium levels: ABCC1 effects in the Strong Heart Family Study
2021
Abstract Genetic effects are suspected to influence cadmium internal dose. Our objective was to assess genetic determinants of urine cadmium in American Indian adults participating in the Strong Heart Family Study (SHFS). Urine cadmium levels and genotyped short tandem repeat (STR) markers were available on 1936 SHFS participants. We investigated heritability, including gene-by-sex and smoking interactions, and STR-based quantitative trait locus (QTL) linkage, using a variance-component decomposition approach, which incorporates the genetic information contained in the pedigrees. We also used available single nucleotide polymorphisms (SNPs) from Illumina’s Metabochip and custom panel to ass…
Thymidylate synthase gene promoter polymorphisms are associated with TSmRNA expressions but not with microsatellite instability in colorectal cancer
2005
Abstract BACKGROUND: Microsatellite instability (MSI) is a biological characteristic of most tumours, being involved in 85% of hereditary non-polyposis colorectal cancer (HNPCC). It also occurs in 10-15% of sporadic colorectal cancers (CRC). HNPCC appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. MSI is also associated with a better response of CRC to adjuvant chemotherapy with fluoropyrimidines. We investigated any relationship between the MSI status and the TSmRNA expression, the polymorphisms of 5-Fluorouracil (5-FU cellular target, the enzyme thymidylate synthase (TS) and TS expression evaluated by…
Retinoblastoma epidemiology: Does the evidence matter?
2007
It has been proposed that retinoblastoma is 'caused' by two sequential mutations affecting the RB1 gene, but this is a rather outdated view of cancer aetiology that does not take into account a large amount of new acquisitions such as chromosomal and epigenetic alterations. Retinoblastoma remains probably the only cancer in which the rather simplistic 'two hit' mutational model is still considered of value, although cancer is known to be associated with genomic and microsatellite instability, defects of the DNA mismatch repair system, alterations of DNA methylation and hystone acethylation/deacethylation, and aneuploidy. Moreover, as it is shown herein, the predictions made by the 'two hit'…
Genotype and phenotype analysis of Friedreich's ataxia compound heterozygous patients
2000
Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FR…
Update on autoimmune hepatitis
2009
Autoimmune hepatitis (AIH) is a necroinflammatory liver disease of unknown etiology that occurs in children and adults of all ages. Characteristics are its autoimmune features, hyperglobulinemia (IgG), and the presence of circulating autoantibodies, as well as a response to immunosuppressant drugs. Current treatment consists of prednisone and azathioprine and in most patients this disease has become very treatable. Over the past 2 years, a couple of new insights into the genetic aspects, clinical course and treatment of AIH have been reported, which will be the focus of this review. In particular, we concentrate on genome-wide microsatellite analysis, a novel mouse model of AIH, the evaluat…
Colorectal cancer with microsatellite instability: Right-sided location and signet ring cell histology are associated with nodal metastases, and extr…
2021
Colorectal cancer (CRC) with microsatellite instability (MSI) accounts for 15-18 % of all CRCs and represents the category with the best prognosis. This study aimed at determining any possible clinical/pathological features associated with a higher risk of nodal metastasization in MSI-CRC, and at defining any possible prognostic moderators in this setting. All surgically resected CRCs of the last 20 years (mono-institutional series) with a PCR-based diagnosis of MSI, with and without nodal metastasis, have been retrieved for histological review, which was performed following WHO guidelines. Furthermore, the most important prognostic moderators have been investigated with a survival analysis…