29 research outputs found

    An endangered tree fern increases beta-diversity at a fine scale in the Atlantic Forest Ecosystem

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    R.N. and T.S.S. were funded by the Brazilian Government research support agency Coordenação de Aperfeiçoamento de Pessoal de NĂ­vel Superior (CAPES). A.E.M. acknowledges the ERC (BioTIME 250189 and BioCHANGE 727440) and the Royal Society. A.R.K. is funded by the Brazilian Science Without Borders scheme/CAPES (109113-1), D.M.S.M. acknowledges the CNPq (Fellowship of Research productivity 307839/2014-1).Some species make substantial contribution to habitat heterogeneity, supporting species coexistence. Dicksonia sellowiana Hook., an endangered tree fern, is a known phorophyte for epiphytes, has the potential to be such a taxon. We tested the hypothesis that D. sellowiana increases plant diversity in Brazilian Restinga forest, a biodiversity hotspot, by augmenting the habitat heterogeneity at a fine scale. To do this we quantified α-diversity and ÎČ-diversity in three habitat types: on the tree fern trunks, immediately beneath the trunks and away from the trunks. In total, 40 ferns were sampled. Overall we recorded 2602 individuals belonging to 61 phanerophyte species in 30 families. The number of individuals sampled varied among habitats but rarefaction showed that richness did not differ. In contrast, species composition varied markedly amongst habitats. Both statistical approaches detected high levels of ÎČ-diversity, particularly between the species found in the vicinity of the fern, and those in the samples away from the trunks. Indicator species analysis was used to identify the species characteristic of the different habitats. About 30% of the species were exclusively found in “away plots”, 17% were exclusively “below plots” and 15% were found only on the trunks, 13% were found on the trunks and below them, 12% on “bellow” and “away plots”, 10% of species occurred in all areas and 3% were found on trunks and “away plots”. Our results lead us to conclude that the endangered fern D. sellowiana plays an important role in promoting habitat heterogeneity within the Restinga forest. As this iconic species is threatened, its overexploitation may lead to impoverishment of plant communities. Conservation effort towards both the area and this species are crucial to maintaining Restinga plant diversity.PostprintPeer reviewe

    Differential regulation of PGC-1α expression in rat liver and skeletal muscle in response to voluntary running

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    <p>Abstract</p> <p>Background</p> <p>The beneficial actions of exercise training on lipid, glucose and energy metabolism and insulin sensitivity appear to be in part mediated by PGC-1α. Previous studies have shown that spontaneously exercised rats show at rest enhanced responsiveness to exogenous insulin, lower plasma insulin levels and increased skeletal muscle insulin sensitivity. This study was initiated to examine the functional interaction between exercise-induced modulation of skeletal muscle and liver PGC-1α protein expression, whole body insulin sensitivity, and circulating FFA levels as a measure of whole body fatty acid (lipid) metabolism.</p> <p>Methods</p> <p>Two groups of male Wistar rats (2 Mo of age, 188.82 ± 2.77 g BW) were used in this study. One group consisted of control rats placed in standard laboratory cages. Exercising rats were housed individually in cages equipped with running wheels and allowed to run at their own pace for 5 weeks. At the end of exercise training, insulin sensitivity was evaluated by comparing steady-state plasma glucose (SSPG) concentrations at constant plasma insulin levels attained during the continuous infusion of glucose and insulin to each experimental group. Subsequently, soleus and plantaris muscle and liver samples were collected and quantified for PGC-1α protein expression by Western blotting. Collected blood samples were analyzed for glucose, insulin and FFA concentrations.</p> <p>Results</p> <p>Rats housed in the exercise wheel cages demonstrated almost linear increases in running activity with advancing time reaching to maximum value around 4 weeks. On an average, the rats ran a mean (Mean ± SE) of 4.102 ± 0.747 km/day and consumed significantly more food as compared to sedentary controls (<it>P </it>< 0.001) in order to meet their increased caloric requirement. Mean plasma insulin (<it>P </it>< 0.001) and FFA (<it>P </it>< 0.006) concentrations were lower in the exercise-trained rats as compared to sedentary controls. Mean steady state plasma insulin (SSPI) and glucose (SSPG) concentrations were not significantly different in sedentary control rats as compared to exercise-trained animals. Plantaris PGC-1α protein expression increased significantly from a 1.11 ± 0.12 in the sedentary rats to 1.74 ± 0.09 in exercising rats (<it>P </it>< 0.001). However, exercise had no effect on PGC-1α protein content in either soleus muscle or liver tissue. These results indicate that exercise training selectively up regulates the PGC-1α protein expression in high-oxidative fast skeletal muscle type such as plantaris muscle.</p> <p>Conclusion</p> <p>These data suggest that PGC-1α most likely plays a restricted role in exercise-mediated improvements in insulin resistance (sensitivity) and lowering of circulating FFA levels.</p

    Modified drug release system based on Sulindac and layered double hydroxide: An in vivo Raman investigation

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    In this study, the capability of a Layered Double Hydroxide (LDH) to promote the modified-release of Sulindac (Sul), a non-steroid anti-inflammatory drug, was followed by Raman spectroscopy through in vitro and in vivo assays. The drug and the LDH-Sul system were pressed into pellets and their dissolution under controlled conditions was monitored in vitro for 80 h. For the in vivo assays, LDH-drug and LDH-CI (with chloride in the interlayer space) pellets were implanted between the external and internal oblique muscles of Wistar rats. The pellets were removed after 7, 21, 28 and 35 days from implantation and up to 21 days there was an increase in the amount of intercalated carbonate ions as followed over time by Raman microscopy. The carbonate ions are from the extracellular fluid (conjunctive tissue) and replace the chloride ions between the LDH layers. The same kind of ion exchange was observed for LDH-Sulindac: ca. 50% of the drug was released in vivo after 21 days, whereas in vitro the same amount of drug was delivered within 24h. The release kinetics was much slower in the in vivo assay due to a significantly smaller hydrodynamic interaction inside the muscle. (C) 2016 Elsevier B.V. All rights reserved.Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, Av Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Cirurgia, R Pedro de Toledo 9,781 Vila Clementino, BR-04039032 Sao Paulo, SP, BrazilDepartamento de Cirurgia, Universidade Federal de São Paulo, R. Pedro de Toledo, 9°, 781, Vila Clementino, 04039-032, São Paulo, SP, BrazilWeb of Scienc

    Correlation between infection rate of triatominies and Chagas Disease in Southwest of Bahia, Brazil: a warning sign?

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    ABSTRACT Chagas disease, caused by the Trypanosoma cruzi, has a wide distribution in South America, and its main method of control is the elimination of triatomines. It is presented here the geographic distribution and the rate of natural infection by T. cruzi of triatomines collected and evaluated from 2008 to 2013 in southwest of Bahia. Triatomines were captured in the intradomiciliary and peridomiciliary areas of five cities located in the southwest of Bahia state, identified, and analyzed for the presence of trypanosomatids in their feces. During the study period the number of patients suspected for acute Chagas disease was recovered from the Notifiable Diseases Information System (SINAN). 8966 triatomines were captured and identified as belonging to eight species. Twenty-six presented themselves infected, being Triatoma sordida the most abundant and with the highest percentage of infection by T. cruzi. Tremedal was the city with the highest number of cases of acute Chagas' disease reported to SINAN. All cities showed triatomines infected with T. cruzi, so there is considerable risk of vectorial transmission of Chagas disease in the southwestern Bahia state, evidencing the need for vector transmission control programs and preventive surveillance measures
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