Browsing by Author "Vergara, Cristian"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Clinical and genetic features of hereditary periodic fever syndromes in Hispanic patients: the Chilean experience
    (2012) Vergara, Cristian; Borzutzky, Arturo; Gutierrez, Miguel A.; Iacobelli, Sergio; Talesnik, Eduardo; Martinez, Maria E.; Stange, Lilith; Basualdo, Javier; Maluje, Viviana; Jimenez, Renato; Wiener, Roberto; Tinoco, Javier; Jarpa, Elena; Arostegui, Juan I.; Yaguee, Jordi; Alvarez-Lobos, Manuel
    Hereditary periodic fever syndromes (HPFS) are rare genetic diseases characterized by recurrent episodes of inflammation. Little information is available concerning HPFS in Latin American Hispanic population. The purpose of this study was to determine the clinical and genetic features of HPFS in Chilean population. A multicenter retrospective study of Hispanic Chilean patients with genetically confirmed HPFS was performed. We included 13 patients, 8 with familial Mediterranean fever (FMF) and 5 with TNF receptor-associated periodic syndrome (TRAPS), evaluated at rheumatology or pediatric rheumatology clinics between January 2007 and December 2010. Median age of symptoms onset was 8 years (range 1-35) and 8 years (range 0.3-21) for FMF and TRAPS, respectively. Median duration of fever was 3 days (range 2.5-15) for FMF and 21 days (range 9.5-30) for TRAPS. Genotyping of the MEFV gene in FMF patients revealed a homozygous M694V missense mutation in one patient, and heterozygous missense mutations in seven patients: M694V (n = 3), E148Q, R717H, A744S, and A511V. Sequencing of the TNFRSF1A gene in TRAPS patients revealed heterozygous missense mutations in four patients: T50M, C30R, R92Q, and IVS3+30:G -> A, and a two-base pair deletion (IVS2-17_18del2bpCT) in one patient. Mutation in MEFV R717H and mutations in TNFRSF1A IVS2-17_18del2bpCT and IVS3+30:G -> A are novel and have not been described previously. This study reports the largest series of genetically confirmed HPFS in Latin America, and adds evidence regarding the clinical and genetic characteristics of patients with FMF and TRAPS in Hispanic population. Mutations identified in MEFV and TNFRSF1A genes include defects reported in other ethnicities and novel mutations.
  • No Thumbnail Available
    Item
    Natural forests loss and tree plantations: large-scale tree cover loss differentiation in a threatened biodiversity hotspot
    (2020) Altamirano, Adison; Miranda, Alejandro; Aplin, Paul; Carrasco, Jaime; Catalan, German; Cayuela, Luis; Fuentes-Castillo, Taryn; Hernandez, Angela; Martinez-Harms, Maria J.; Peluso, Franco; Prado, Marco; Reyes-Riveros, Rosa; Van Holt, Tracy; Vergara, Cristian; Zamorano-Elgueta, Carlos; Di Bella, Carlos
    Distinguishing between natural forests from exotic tree plantations is essential to get an accurate picture of the world's state of forests. Most exotic tree plantations support lower levels of biodiversity and have less potential for ecosystem services supply than natural forests, and differencing them is still a challenge using standard tools. We use a novel approach in south-central of Chile to differentiate tree cover dynamics among natural forests and exotic tree plantations. Chile has one of the world's most competitive forestry industry and the region is a global biodiversity hotspot. Our collaborative visual interpretation method combined a global database of tree cover change, remote sensing from high-resolution satellite images and expert knowledge. By distinguishing exotic tree plantation and natural forest loss, we fit spatially explicit models to estimate tree-cover loss across 40 millions of ha between 2000 and 2016. We were able to distinguish natural forests from exotic tree plantations with an overall accuracy of 99% and predicted forest loss. Total tree cover loss was continuous over time, and the disaggregation revealed that 1 549 909 ha of tree plantations were lost (mean = 96 869 ha year(-1)), while 206 142 ha corresponded to natural forest loss (mean = 12 884 ha year(-1)). Mostly of tree plantations lost returned to be plantation (51%). Natural forests were converted mainly (75%) to transitional land covers (e.g. shrubland, bare land, grassland), and an important proportion of these may finish as tree plantation. This replacement may undermine objectives of increasedcarbon storage and biodiversity. Tree planting as a solution has gained increased attention in recen years with ambitious commitments to mitigate the effects of climate change. However, negative outcomes for the environment could result if strategies incentivize the replacement of natural forests into other land covers. Initiatives to reduce carbon emissions should encourage differentiating natural forests from exotic tree plantations and pay more attention on protecting and managing sustainably the former.