51 research outputs found

    Testing for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in a European family-based study

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    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

    Intrinsic and extrinsic factors influencing large African herbivore movements

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    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

    Radiofrequency ablation of bone tumours

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    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

    Analysis of a T-cell receptor V beta segment implicated in susceptibility to rheumatoid arthritis: V beta 2 germline polymorphism does not encode susceptibility.

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    OBJECTIVES--The assessment of allelic polymorphism of the T cell receptor gene segment, TCRBV2S1, in rheumatoid arthritis. METHODS--A total of 136 patients with rheumatoid arthritis (RA) (ACR criteria) and 150 controls were TCRBV2S1 genotyped using a nested PCR amplification strategy followed by single-strand conformation polymorphism (SSCP) analysis. RESULTS--The SSCP typing method detected two previously unknown alleles of the TCRBV2S1 gene segment. The TCRBV2S1 allele, genotype and inferred phenotype frequencies were similar in the RA patients and controls. No differences were apparent after the RA patients had been partitioned according to their HLA-DR genotypes. CONCLUSIONS--SSCP analysis is a rapid and efficient method of typing T cell receptor germline polymorphisms. Allelic polymorphism of the T cell receptor variable segment, TCRBV2S1, does not influence susceptibility to RA

    Phylogeography and conservation genomics of the African lion (Panthera leo) at a continental and local scale based on mitochondrial and nuclear molecular markers

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    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
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