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Fábio Souto Almeida Luciana Elizalde Leticia Maria Souto Silva Jarbas Marçal Queiroz 《Revista Brasileira de Entomologia》2019,63(4):296-301
Ants can influence soil fertility and the spatial distribution of seeds, with possible effects on seedling recruitment. The ant species Pachycondyla striata Fr. Smith, 1858 and Odontomachus chelifer (Latreille, 1802) co-occur in many forest areas in the Neotropics. We assessed soil fertility and seed bank structure in soil samples close and distant (control) from ant nests in forest fragments. We also assessed the richness and abundance of seedlings on nests and control sites. In soil samples from ant nests, the concentration of phosphorus and potassium were respectively 55.6% and 36% higher than in control sites. Aluminium was 11–15% lower in soil samples from ant nests. In the greenhouse, soils from ant nests had higher plant abundance and species richness, but the same species composition in comparison with control sites. Although more plants emerged from soil samples of O. chelifer nests, in the field, the density and richness of seedlings were similar for the two ant species studied. Seedlings in the nest sites were, on average, 1.8 times more abundant and 1.6 times richer in species than in control sites. Our results showed that ant species can play a key role in seedling recruitment in forest fragments, where other animals with equivalent and positive effects, such as mammals, are missing. 相似文献
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125.
Bruno de Souza Gonçalves Jéssica M. de Moura Valadares Silmara L. G. Alves Simone C. Silva Luciana P. Rangel Vanessa F. Cortes José A. F. P. Villar Leandro A. Barbosa Hérica de Lima Santos 《Journal of cellular biochemistry》2019,120(10):17108-17122
Recently, cardiotonic steroids (CTS) have been shown to lead to the activation of Na,K-ATPase at low concentrations in brain, promoting neuroprotection against ischemia. We report here the results of the use of digoxin and its semisynthetic derivatives BD-14, BD-15, and BD-16 against partial chemical ischemic induction followed by reperfusion in murine neuroblastoma cells neuro-2a (N2a). For chemical ischemic induction, sodium azide (5 mM) was used for 5 hours, and then reperfusion was induced for 24 hours. Na,K-ATPase activity and protein levels were analyzed in membrane preparation of N2a cells pretreated with the compounds (150 nM), in the controls and in induced chemical ischemia. In the Na,K-ATPase activity and protein levels assays, the steroids digoxin and BD-15 demonstrated a capacity to modulate the activity of the enzyme directly, increasing its levels of expression and activity. Oxidative parameters, such as superoxide dismutase (SOD) activity, lipid peroxidation (thiobarbituric acid reactive substance), glutathione peroxidase (GPx), glutathione (GSH) levels, hydrogen peroxide content, and the amount of free radicals (reactive oxygen species) during induced chemical ischemia were also evaluated. Regarding the redox state, lipid peroxidation, hydrogen peroxide content, and GPx activity, we have observed an increase in the chemical ischemic group, and a reduction in the groups treated with CTS. SOD activity increased in all treated groups when compared to control and GSH levels decreased when treated with sodium azide and did not change with CTS treatments. Regarding the lipid profile, we saw a decrease in the content of phospholipids and cholesterol in the chemical ischemic group, and an increase in the groups treated with CTS. In conclusion, the compounds used in this study demonstrate promising results, since they appear to promote neuroprotection in cells exposed to chemical ischemia. 相似文献
126.
Luciana Gabriel Nogueira Ronaldo Honorato Barros Santos Barbara Maria Ianni Alfredo Inácio Fiorelli Eliane Conti Mairena Luiz Alberto Benvenuti Amanda Frade Eduardo Donadi Fabrício Dias Bruno Saba Hui-Tzu Lin Wang Abilio Fragata Marcelo Sampaio Mario Hiroyuki Hirata Paula Buck Charles Mady Edimar Alcides Bocchi Noedir Antonio Stolf Jorge Kalil Edecio Cunha-Neto 《PLoS neglected tropical diseases》2012,6(10)
Background
Chronic Chagas cardiomyopathy (CCC), a life-threatening inflammatory dilated cardiomyopathy, affects 30% of the approximately 8 million patients infected by Trypanosoma cruzi. Even though the Th1 T cell-rich myocarditis plays a pivotal role in CCC pathogenesis, little is known about the factors controlling inflammatory cell migration to CCC myocardium.Methods and Results
Using confocal immunofluorescence and quantitative PCR, we studied cell surface staining and gene expression of the CXCR3, CCR4, CCR5, CCR7, CCR8 receptors and their chemokine ligands in myocardial samples from end-stage CCC patients. CCR5+, CXCR3+, CCR4+, CCL5+ and CXCL9+ mononuclear cells were observed in CCC myocardium. mRNA expression of the chemokines CCL5, CXCL9, CXCL10, CCL17, CCL19 and their receptors was upregulated in CCC myocardium. CXCL9 mRNA expression directly correlated with the intensity of myocarditis, as well as with mRNA expression of CXCR3, CCR4, CCR5, CCR7, CCR8 and their ligands. We also analyzed single-nucleotide polymorphisms for genes encoding the most highly expressed chemokines and receptors in a cohort of Chagas disease patients. CCC patients with ventricular dysfunction displayed reduced genotypic frequencies of CXCL9 rs10336 CC, CXCL10 rs3921 GG, and increased CCR5 rs1799988CC as compared to those without dysfunction. Significantly, myocardial samples from CCC patients carrying the CXCL9/CXCL10 genotypes associated to a lower risk displayed a 2–6 fold reduction in mRNA expression of CXCL9, CXCL10, and other chemokines and receptors, along with reduced intensity of myocarditis, as compared to those with other CXCL9/CXCL10 genotypes.Conclusions
Results may indicate that genotypes associated to reduced risk in closely linked CXCL9 and CXCL10 genes may modulate local expression of the chemokines themselves, and simultaneously affect myocardial expression of other key chemokines as well as intensity of myocarditis. Taken together our results may suggest that CXCL9 and CXCL10 are master regulators of myocardial inflammatory cell migration, perhaps affecting clinical progression to the life-threatening form of CCC. 相似文献127.
Amanda Ferreira da Silva Mendes Luciana Cardoso Cidade Maria Luiza Peixoto de Oliveira Wagner Campos Otoni Walter Dos Santos Soares-Filho Marcio Gilberto Cardoso Costa 《Plant Cell, Tissue and Organ Culture》2009,97(3):331-336
Identification of beta-lactam antibiotics that have negligible effects on plant regeneration is a critical step towards the
establishment of a reliable Agrobacterium-mediated transformation protocol for perennial trees. In the present report, we have evaluated the effects of the novel beta-lactam
antibiotics meropenem and timentin on plant regeneration of a perennial woody fruit plant, Citrus sinensis, in comparison with the commonly used beta-lactam cefotaxime. It was observed that, in contrast to cefotaxime, meropenem
and timentin had a positive or no detrimental effect on the shoot regeneration from epicotyl explants. Residual effects of
the beta-lactams from shoot regeneration medium also affected the subsequent ability of the roots to elongate. The addition
of meropenem and/or timentin in the rooting medium mostly improved or did not affect the rooting ability of the adventitious
shoots. These data indicated that meropenem and timentin can positively replace cefotaxime in Agrobacterium-mediated transformation of C. sinensis. 相似文献
128.
Jesus LM Abreu PR Almeida MC Brito LC Soares SF de Souza DE Bernardo LC Fonseca AS Bernardo-Filho M 《Acta biologica Hungarica》2006,57(2):191-200
Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds. 相似文献
129.
Failure of Helicobacter pylori treatment is a growing problem in daily practice. Aim: To evaluate the efficacy of two new regimes as second‐line options in a randomized and prospective study. Methods: Patients in whom a first eradication regime containing clarithromycin had failed were included. After performing gastroscopy and a 13C‐urea breath test (UBT), the patients were randomized to receive a combination of 20 mg of rabeprazole, 500 mg of levofloxacin, and 200 mg (two tablets) of furazolidone administered once daily for 10 days (RLF) or the combination of 20 mg of rabeprazole, 120 mg (two tablets) of bismuth subcitrate, 100 mg of doxycycline, and 200 mg of furazolidone, administered twice daily for 10 days (RBDF). Clinical examinations and new UBT were performed 60 days after therapy. Results: Sixty patients were included (mean age, 46 years, 57% females). Two patients were excluded: one because of adverse effects and another as a result of protocol violation. Compliance was similar in both groups (90% took all medications correctly). Side‐effects (96% mild) were observed in 87% of the patients and were comparable between groups, except diarrhea, which was more frequent in group RLF (p= .025). Intention‐to‐treat cure rates were 77% (95% confidence interval (CI): 62–93%) in the RLF group and 83% (95% CI: 68–97%) in the RBDF group (p= .750). Per‐protocol cure rates were 80% (95% CI: 65–95%) in the RLF group and 82% (95% CI: 67–96%) in the RBDF group (p= 1.0). Conclusions: Both once‐daily triple (rabeprazole, levofloxacin, and furazolidone) and twice‐daily quadruple therapy (rabeprazole, bismuth subcitrate, doxycycline, and furazolidone) for 10 days achieved encouraging results. Subsequent studies should be performed to evaluate antibiotic resistance, doses, dosing intervals, duration of treatment, and safety of these two regimes. 相似文献
130.
Tullio Palmerini Luciana Tomasi Chiara Barozzi Diego Della Riva Andrea Mariani Nevio Taglieri Ornella Leone Claudio Ceccarelli Stefano De Servi Angelo Branzi Philippe Genereux Gregg W. Stone Jasimuddin Ahamed 《PloS one》2013,8(12)