77 research outputs found

    Use of passive samplers to detect Organochlorine Pesticides in air and water at Wetland Mountain region sites (S-SE Brazil)

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    Low-density polyethylene (LDPE) passive samplers were deployed in upland surface waters and the overlying atmosphere during May and June 2012, to determine the transport and trends of freely dissolved and gaseous organochlorine pesticides (OCPs) along altitudinal gradients in mountain regions in south and southeast Brazil. Gaseous OCP concentrations were dominated by hexachlorobenzene (3.0 to 29 pg.m-3) and endosulfans (Æ©= α-endosulfan + ÎČ-endosulfan + endosulfan sulphate, 170 to 260 pg.m-3), whereas freely dissolved endosulfans were significantly higher than all other OCPs (p \u3c 0.001). The presence of some target pesticides at the highest elevation sites indicated their efficient high-altitude transport from regional sources. Air-water exchange gradients indicated net deposition of most volatile and recently banned OCPs (e.g., HCB, endosulfan) over Brazilian mountains. Moreover, the exposure of these sites to large-scale continental airflows with varying source contributions may partly explain the atmospheric deposition of selected OCPs over upland freshwaters at tropical and subtropical mountains sites in Brazil. These findings, couple with LDPE passive air and water sampling measurements, point out the potential inputs from distant sources of semi-volatile chemicals to the two high-altitude sites

    LTBP2 null mutations in an autosomal recessive ocular syndrome with megalocornea, spherophakia, and secondary glaucoma

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    The latent TGFÎČ-binding proteins (LTBPs) and fibrillins are a superfamily of large, multidomain proteins with structural and TGFÎČ-signalling roles in the extracellular matrix. Their importance is underscored by fibrillin-1 mutations responsible for Marfan syndrome, but their respective roles are still incompletely understood. We report here on two families where children from healthy, consanguineous parents, presented with megalocornea and impaired vision associated with small, round, dislocated lenses (microspherophakia and ectopia lentis) and myopia, as well as a high-arched palate, and, in older children, tall stature with an abnormally large arm span over body height ratio, that is, associated features of Marfan syndrome. Glaucoma was not present at birth, but was diagnosed in older children. Whole genome homozygosity mapping followed by candidate gene analysis identified homozygous truncating mutations of LTBP2 gene in patients from both families. Fibroblast mRNA analysis was consistent with nonsense-mediated mRNA decay, with no evidence of mutated exon skipping. We conclude that biallelic null LTBP2 mutations cause the ocular phenotype in both families and could lead to Marfan-like features in older children. We suggest that intraocular pressures should be followed-up in young children with an ocular phenotype consisting of megalocornea, spherophakia and/or lens dislocation, and recommend LTBP2 gene analysis in these patients

    Caloric Restriction Is More Efficient than Physical Exercise to Protect from Cisplatin Nephrotoxicity via PPAR-Alpha Activation

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    The antineoplastic drug cisplatin promotes renal injury, which limits its use. Protocols that reduce renal cisplatin toxicity will allow higher doses to be used in cisplatin treatment. Here, we compare physical exercise and caloric restriction (CR) as protocols to reduce cisplatin renal injury in mice. Male C57BL/6 were divided into four groups: Control, cisplatin, exercise + cisplatin, and 30% CR + cisplatin. Animals were injected with a single dose of cisplatin (20 mg/kg i.p.) and sacrificed 96 h after injection. Quantitative real time PCR, histological analyses, immunohistochemistry, and biochemical measurements were performed to investigate renal injury, necrosis, apoptosis, and inflammatory mechanisms. Both protocols protected against cisplatin renal injury, but CR was more effective in reducing uraemia and renal necrosis. The CR + Cisplatin group exhibited reduced serum IL-1 beta and INF-alpha levels. No differences were noted in the renal mRNA expression of cytokines. Both interventions reduced apoptosis, but only the CR + Cisplatin group decreased TNFR2 protein expression. PPAR-ci was activated in mice after CR. An antagonist of PPAR-alpha blocked the protective effect of CR. Both interventions attenuated the nephrotoxicity caused by cisplatin injection, but CR + Cisplatin showed a better response by modulating TNFR2. Moreover, part of the CR benefit depends on PPAR-alpha activation.FAPESP (Fundacao de Apoio a Pesquisa do Estado de Sao Paulo)CAPES/DAADUniv Fed Sao Paulo, Dept Biofis, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Disciplina Nefrol, Sao Paulo, BrazilUniv Sao Paulo, Inst Ciencias Biomed, Dept Immunol, Sao Paulo, BrazilUniv Sao Paulo, Dept Clin Med, Sao Paulo, BrazilUniv Fed Pelotas, Escola Nutr, Dept Nutr, Pelotas, BrazilMax Delbruck Ctr Mol Med, Berlin, GermanyUniv Fed Sao Paulo, Dept Biofis, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Med, Disciplina Nefrol, Sao Paulo, BrazilFAPESP: 2013/06207-6FAPESP: 2015/20082-7CAPES/DAAD: 427/15Web of Scienc

    Quantification of the groundwater-surface water interaction by analysing temperature gradients in the streambed of the Aa river, Belgium

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    The aim of this research is to gain better insight in the diverse physical and biological processes in margins, inundation areas and the hyporheic zone of water courses on a local scale. Data and results presented are from a multidisciplinary study on exchange processes in river ecosystems in which biologists, hydrologists, ecologists and engineers cooperate.Groundwater and eco-biochemical models are integrated in order to determine the exchange of water, dissolved compounds and particulate matter. Several of these processes occur simultaneously and result in feedback to other processes; hence most of the investigations aim to determine net rates of exchange. GIS is used for data management, while FEMME (Soetaert et al., 2002) serves as a platform for the integration of the different models such as MODFLOW, DAFLOW, Delft3D, and WetSpa.An innovative but cost-effective method for field investigation is the measurement of streambed temperatures profiles, which lead to a delineation and quantification of the groundwater discharge on a local scale. For the Aa River site in Belgium, a typical low land river system, combinations of longitudinal and cross-sectional measurements of temperature profiles have been conducted. Along a 1400 m long section, 5 vertical measurements of up to 80-100 cm deep into the river bottom have been performed bi-monthly between August 2004 and February 2007 at 14 measurement points and 5 cross-sections. With this information we assessed the vertical component of the groundwater flux and the spatial and temporal variability of the groundwater-surface water exchange.A streambed temperature survey does not lead directly to an estimation of the groundwater flux. Additional information, especially thermodynamic parameters of the soilwater matrix are necessary.The groundwater fluxes were calculated as point values at the measurement locations on basis of an analytical solution presented by Arriaga et al. (2006), and which is solved with the help of Microsoft Excel Solver and MATLAB. The fundamental heat flow equation was also introduced in a diagenetic model, setup in FEMME and used to compare with the Arriaga et al. (2006) solution. Interpolation of the point estimates results in net groundwater fluxes on the scale of the surveyed area. These results show discharge as well as recharge dependent on the location along the section and the season. The upper reach shows in general higher discharge rates and no change in direction of the groundwater flow, whereas the lower reach is characterized by lower flow rates and a change of direction of flow

    Temporal controls on silicic acid utilisation along the West Antarctic Peninsula

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    The impact of climatic change along the Antarctica Peninsula has been widely debated in light of atmospheric/oceanic warming and increases in glacial melt over the past half century. Particular concern exists over the impact of these changes on marine ecosystems, not only on primary producers but also on higher trophic levels. Here we present a record detailing the historical controls on the biogeochemical cycling of silicic acid [Si(OH)4] on the west Antarctica Peninsula margin, a region in which the modern phytoplankton environment is constrained by seasonal sea-ice. We demonstrate that Si(OH)4 cycling through the Holocene alternates between being primarily regulated by sea-ice or glacial discharge from the surrounding grounded ice-sheet. With further climate-driven change and melting forecast for the 21st Century, our findings document the potential for biogeochemical cycling and multi-trophic interactions along the peninsula to be increasingly regulated by glacial discharge, altering food-web interactions

    Multi-system neurological disease is common in patients with OPA1 mutations

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    Additional neurological features have recently been described in seven families transmitting pathogenic mutations in OPA1, the most common cause of autosomal dominant optic atrophy. However, the frequency of these syndromal ‘dominant optic atrophy plus’ variants and the extent of neurological involvement have not been established. In this large multi-centre study of 104 patients from 45 independent families, including 60 new cases, we show that extra-ocular neurological complications are common in OPA1 disease, and affect up to 20% of all mutational carriers. Bilateral sensorineural deafness beginning in late childhood and early adulthood was a prominent manifestation, followed by a combination of ataxia, myopathy, peripheral neuropathy and progressive external ophthalmoplegia from the third decade of life onwards. We also identified novel clinical presentations with spastic paraparesis mimicking hereditary spastic paraplegia, and a multiple sclerosis-like illness. In contrast to initial reports, multi-system neurological disease was associated with all mutational subtypes, although there was an increased risk with missense mutations [odds ratio = 3.06, 95% confidence interval = 1.44–6.49; P = 0.0027], and mutations located within the guanosine triphosphate-ase region (odds ratio = 2.29, 95% confidence interval = 1.08–4.82; P = 0.0271). Histochemical and molecular characterization of skeletal muscle biopsies revealed the presence of cytochrome c oxidase-deficient fibres and multiple mitochondrial DNA deletions in the majority of patients harbouring OPA1 mutations, even in those with isolated optic nerve involvement. However, the cytochrome c oxidase-deficient load was over four times higher in the dominant optic atrophy + group compared to the pure optic neuropathy group, implicating a causal role for these secondary mitochondrial DNA defects in disease pathophysiology. Individuals with dominant optic atrophy plus phenotypes also had significantly worse visual outcomes, and careful surveillance is therefore mandatory to optimize the detection and management of neurological disability in a group of patients who already have significant visual impairment
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