67 research outputs found
Testing for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in a European family-based study
INTRODUCTION:
A candidate gene approach, in a large case-control association study in the Dutch population, has shown that a 480 kb block on chromosome 4q27 encompassing KIAA1109/Tenr/IL2/IL21 genes is associated with rheumatoid arthritis. Compared with case-control association studies, family-based studies have the added advantage of controlling potential differences in population structure. Therefore, our aim was to test this association in populations of European origin by using a family-based approach.
METHODS:
A total of 1,302 West European white individuals from 434 trio families were genotyped for the rs4505848, rs11732095, rs6822844, rs4492018 and rs1398553 polymorphisms using the TaqMan Allelic discrimination assay (Applied Biosystems). The genetic association analyses for each SNP and haplotype were performed using the Transmission Disequilibrium Test and the genotype relative risk.
RESULTS:
We observed evidence for association of the heterozygous rs4505848-AG genotype with rheumatoid arthritis (P = 0.04); however, no significance was found after Bonferroni correction. In concordance with previous findings in the Dutch population, we observed a trend of undertransmission for the rs6822844-T allele and rs6822844-GT genotype to rheumatoid arthritis patients. We further investigated the five SNP haplotypes of the KIAA1109/Tenr/IL2/IL21 gene region. We observed, as described in the Dutch population, a nonsignificant undertransmission of the AATGG haplotype to rheumatoid arthritis patients.
CONCLUSIONS:
Using a family-based study, we have provided a trend for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in populations of European descent. Nevertheless, we failed to replicate a significant association of this region in our rheumatoid arthritis family sample. Further investigation of this region, including detection and testing of all variants, is required to confirm rheumatoid arthritis association
An operational model for capturing grape ripening dynamics to support harvest decisions
Grape ripening is a critical phenological phase during which many metabolites that impact wine quality accumulate in the berries. Major changes in berry composition include a rapid increase in sugar and a decrease in malic acid content and concentration. Its duration is highly variable depending on grapevine variety, climatic parameters, soil type and management practices. Together with the timing of mid-veraison, this duration determines when grapes can be harvested.
Viticulturists and winemakers monitor the sugar-to-total acidity ratio (S/TA) during grape ripening and start harvesting grapes when this ratio reaches the optimum value for the desired wine style. The S/TA ratio evolves linearly as a function of thermal summation during the first four weeks following the onset of ripening. The linearity of the evolution of the S/TA ratio as a function of thermal time during the first four weeks following mid-veraison is applied in this study on two large data sets encompassing (1) 53 varieties studied during 10 years with two to four replicates for each combination of year and cultivar and (2) two varieties, cultivated on three soil types over 13 years. Grape ripening speed is highly variable. The effects of the year impact ripening speed more than the effects of the soil or the variety, although all three effects are highly significant. Grape ripening speed decreases with berry weight and also varies with vine water status. By using this approach, viticulturists and winemakers can assess four weeks after mid-veraison, for each individual vineyard parcel, at what speed grape ripening progresses. Combined with precise mid-veraison scoring, expertise from previous vintages and complementary approaches like sensory assessment of berries, it allows harvest date estimates to be fine-tuned. The results of this study can also be used to identify slow ripening varies, which are better performing in warm climates and, thus, better adapted to climate change
Intrinsic and extrinsic factors influencing large African herbivore movements
This document is the Accepted Manuscript version of the following article: Jan A. Venter, Herbert H. T. Prins, Alla Mashanova, Willem F. de Boer, and Rob Slotow, 'Intrinsic and extrinsic factors influencing large African herbivore movements', Ecological Informatics, Vol. 30: 257-262, November 2015, doi: https://doi.org/10.1016/j.ecoinf.2015.05.006. This manuscript version is made available under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.Understanding environmental as well as anthropogenic factors that influence large herbivore ecological patterns and processes should underpin their conservation and management. We assessed the influence of intrinsic, extrinsic environmental and extrinsic anthropogenic factors on movement behaviour of eight African large herbivore species. A cumulative odds ordinal logistic regression was used to determine the effect of season, feeding niche, number of vegetation types, home range size, and fences on the number of exponential distributions observed. When animals faced the trade-off between forage quality and quantity during the dry season, they moved further between forage areas and water sources in order to get to better forage, which added to the number of movement scales observed. Elephants had a lower number of movement scales, compared to all the other feeding types, which could be attributed to them being able to switch between browse and graze. The number of movement scales increased in more heterogeneous areas. Animals with larger home ranges, which are also larger species, and animals more restricted by fences, had fewer movement scales. In order for managers to effectively manage protected areas and associated biodiversity they need take cognisance of the different scales animals operate under, and the different factors that may be important for different species.Peer reviewe
Structural and Thermo-mechanical Evaluation of Two Engineering Thermoplastic Polymers in Contact with Ethanol Fuel from Sugarcane
Prevalence and Distribution of Autoimmune Diseases in 368 Rheumatoid Arthritis Families
International audienceObjective. To investigate whether frequency of rheumatoid arthritis (RA) and/or other autoimmune (AI) disorders was increased in RA French Caucasian families among the first- (FDR) and second-degree relatives (SDR), and to test whether the presence of AI disease family history identified a specific RA subset. Methods. We conducted telephone interviews to obtain histories of AI diseases among the FDR and SDR of 368 RA probands, belonging either to trio or affected sib-pair (ASP) families. All the AI diagnoses were confirmed by the physician of the affected relative. Results. Probands of the ASP families were characterized by older age at RA onset, longer disease duration, and larger family size versus trio families. In the trio families, the prevalence of AI diseases was 6.05% (4.76%-7.57%) in FDR and 2.40% (1.85%-3.06%) in SDR. In ASP families, the prevalence of AI diseases was, respectively, 10.24% (8.68%-11.97%) and 1.79% (1.41%-2.25%). The most frequent AI diseases among relatives were RA, thyroid AI diseases, and vitiligo. In trio families, a proband with a mean age of RA onset \backslashtextless 30 years was associated with AI disease prevalence in the relatives, and male gender was associated with prevalence of RA among the FDR. Conclusion. The prevalence of AI diseases is increased, particularly among FDR, in French RA families, and some characteristics of the RA proband seem to be associated with prevalence of AI diseases in families
Radiofrequency ablation of bone tumours
AbstractThe indications for radiofrequency bone ablation in the case of benign tumours (osteoid osteoma, osteoblastoma) are curative, whereas for bone metastases, the prime aim is palliative analgesia. The failure rate for osteoid osteomas is low (<15%), and 70 to 90% of patients with metastases experience considerable relief, but if the treatment fails, it can be offered again. In the spine, heating can damage neighboring nerve structures, which means they need to be protected (CO2 dissection). Radiofrequency ablation may be combined with an injection of cement. The osteonecrosis resulting from heating is painful and justifies performing the procedure under general anesthesia
Phylogeography and conservation genomics of the African lion (Panthera leo) at a continental and local scale based on mitochondrial and nuclear molecular markers
Presented at the 9th international wildlife ranching symposium: wildlife - the key to prosperity for rural communities, held on 12-16 September 2016 at Hotel Safari & the Safari Court, Windhoek, Namibia.The African lion (Panthera leo) is listed as "vulnerable" by the IUCN Red List, mainly threatened by indiscriminate killing, primarily as a result of retaliatory or pre-emptive killing to protect human life and livestock, and prey base depletion. Habitat loss and conversion has led to a number of subpopulations becoming small and isolated. With the weakened connectivity between the main strongholds, genetic drift and loss of genetic diversity could affect the genetic health of the species. In the present study, we investigated the evolutionary history of the species at different scales of time and space. A total of 182 samples were used, including a larger number of 77 samples from Tanzanian protected areas. The mitochondrial cytochrome b gene was sequenced and the specimens were genotyped for 11 microsatellites and more than 9,000 SNPs. The preliminary results indicate that the lion is structured into two lineages at the continental scale (West-Central vs South-Eastern), a pattern observed within many other large African savanna species displaying large distribution ranges. Pleistocene climatic oscillations and biogeographical barriers were proposed as the main factors to have driven the lineage sorting. The first results based on microsatellites highlighted that the Tanzanian population displayed good level of genetic diversities with no signs of inbreeding. Indication of isolation-by-distance nevertheless highlighted a potential future impact of fragmentation on the population genetic health. SNPs allowed to identify 3 populations of lions in Tanzania, geographically structured. Using various molecular markers, the present work will further explore the taxonomy and the evolutionary history of the African lion for bringing insights in its conservation requirements
The R620W Polymorphism of the Protein Tyrosine Phosphatase 22 Gene in Autoimmune Thyroid Diseases and Rheumatoid Arthritis in the Tunisian Population
International audienceBackground: Protein tyrosine phosphatase (PTPN22) is involved in the negative regulation of T-cell responsiveness. The association of a coding variant of the PTPN22 gene (R620W) with a number of autoimmune diseases has been described. Aim: The present study investigated whether PTPN22 gene polymorphism was also involved in the genetic predisposition to autoimmune thyroid diseases (AITDs) and rheumatoid arthritis (RA) in a Tunisian case control study. Subjects and methods: DNA samples from 150 patients affected with RA, 204 patients affected with AITDs and 236 healthy controls were genotyped for PTPN22 R620W polymorphism (1858C/T). Genotyping was performed by the polymerase chain reactionrestriction fragment length polymorphism method. Results: No significant differences in T allele frequency (2.3% in RA patients and 1% in AITDs patients vs 2.6% in controls; p=0.85 and p=0.08, respectively) and in genotype frequencies were detected between RA patients and controls (p=0.15) and between AITDs patients (p=0.11). Stratifying patients affected with AITDs according to their phenotype (Graves' disease and Hashimoto's thyroiditis) and RA patients according to the presence of rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (ACPA) did not show any significant association with PTPN22 R620W allele (p\backslashtextgreater0.05). Conclusion: Our data suggest that the PTPN22 C1858T single nucleotide polymorphism has no or minor effect on RA and AITDs susceptibility in the Tunisian population. © 2009 Informa UK Ltd
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