71 research outputs found

    Vascular endothelial growth factor: an angiogenic factor reflecting airway inflammation in healthy smokers and in patients with bronchitis type of chronic obstructive pulmonary disease?

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    <p>Abstract</p> <p>Background</p> <p>Patients with bronchitis type of chronic obstructive pulmonary disease (COPD) have raised vascular endothelial growth factor (VEGF) levels in induced sputum. This has been associated with the pathogenesis of COPD through apoptotic and oxidative stress mechanisms. Since, chronic airway inflammation is an important pathological feature of COPD mainly initiated by cigarette smoking, aim of this study was to assess smoking as a potential cause of raised airway VEGF levels in bronchitis type COPD and to test the association between VEGF levels in induced sputum and airway inflammation in these patients.</p> <p>Methods</p> <p>14 current smokers with bronchitis type COPD, 17 asymptomatic current smokers with normal spirometry and 16 non-smokers were included in the study. VEGF, IL-8, and TNF-α levels in induced sputum were measured and the correlations between these markers, as well as between VEGF levels and pulmonary function were assessed.</p> <p>Results</p> <p>The median concentrations of VEGF, IL-8, and TNF-α were significantly higher in induced sputum of COPD patients (1,070 pg/ml, 5.6 ng/ml and 50 pg/ml, respectively) compared to nonsmokers (260 pg/ml, 0.73 ng/ml, and 15.4 pg/ml, respectively, p < 0.05) and asymptomatic smokers (421 pg/ml, 1.27 ng/ml, p < 0.05, and 18.6 pg/ml, p > 0.05, respectively). Significant correlations were found between VEGF levels and pack years (r = 0.56, p = 0.046), IL-8 (r = 0.64, p = 0.026) and TNF-α (r = 0.62, p = 0.031) levels both in asymptomatic and COPD smokers (r = 0.66, p = 0.027, r = 0.67, p = 0.023, and r = 0.82, p = 0.002, respectively). No correlation was found between VEGF levels in sputum and pulmonary function parameters.</p> <p>Conclusion</p> <p>VEGF levels are raised in the airways of both asymptomatic and COPD smokers. The close correlation observed between VEGF levels in the airways and markers of airway inflammation in healthy smokers and in smokers with bronchitis type of COPD is suggestive of VEGF as a marker reflecting the inflammatory process that occurs in smoking subjects without alveolar destruction.</p

    Large-scale climatic phenomena drive fluctuations in macroinvertebrate assemblages in lowland tropical streams, Costa Rica: The importance of ENSO events in determining long-term (15y) patterns

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    Understanding how environmental variables influence the distribution and density of organisms over relatively long temporal scales is a central question in ecology given increased climatic variability (e.g., precipitation, ENSO events). The primary goal of our study was to evaluate long-term (15y time span) patterns of climate, as well as environmental parameters in two Neotropical streams in lowland Costa Rica, to assess potential effects on aquatic macroinvertebrates. We also examined the relative effects of an 8y whole-stream P-enrichment experiment on macroinvertebrate assemblages against the backdrop of this long-term study. Climate, environmental variables and macroinvertebrate samples were measured monthly for 7y and then quarterly for an additional 8y in each stream. Temporal patterns in climatic and environmental variables showed high variability over time, without clear inter-annual or intra-annual patterns. Macroinvertebrate richness and abundance decreased with increasing discharge and was positively related to the number of days since the last high discharge event. Findings show that fluctuations in stream physicochemistry and macroinvertebrate assemblage structure are ultimately the result of large-scale climatic phenomena, such as ENSO events, while the 8y P-enrichment did not appear to affect macroinvertebrates. Our study demonstrates that Neotropical lowland streams are highly dynamic and not as stable as is commonly presumed, with high intra- and inter-annual variability in environmental parameters that change the structure and composition of freshwater macroinvertebrate assemblages.This study was financed by National Science Foundation (DEB 1122389) to Catherine M. Pringle. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR

    Biological screening to identify antifungal agents produced by Streptomyces sp. isolated from the Caatinga Biome.

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    Microbial secondary metabolites have been considered a promising natural source to disclose biologically active compounds, which can be applied in the pharmaceutical and agroindustrial sectors. Actinobacterias have played an important role in the historical advances of antibiotics and antifungals development1,2. Besides the wide application in the medicinal field as an antifungal agent, it can be also used as a natural alternative to inhibit the pathogenic microorganism?s growth in agriculture. On the other hand, now concerning the citrus fruits market, an inefficient fungi infection control results in a significant profit loss. This study shows the antibiosis screening assays of 196 microorganism?s crude extracts in order to identify antifungal activity against Colletotrichum gloeosporioides fungi. The Streptomyces sp. Caat 5-35 crude extract presented the highest antifungal activity (Figure 1-A). Mass spectrometry (MS) is an important dereplication process tool of these metabolites in the crude extract. It allows fast and sensitive analysis and provides valuable structural information. The active crude extract was fractionated in a preparative HPLC method and bioassays were performed in all the fractions in order to identify the active fraction. The Fr16 fraction exhibited notable antimicrobial activity by disk diffusion method assay. The chromatogram LC-MS/MS for the active fraction presented only one peak at 5.16 minutes, which corresponds to the ionic species [M+H]+ of m/z 521.2. Spectroscopic UV, NMR 1D and 2D data confirm that the active compound is the Albofungin3

    Feeding propolis or essential oils (cashew and castor) to bulls: performance, digestibility, and blood cell counts

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    Background: in cattle production systems, antibiotics are commonly fed to cattle to prevent diseases, metabolic disorders, and to improve feed efficiency. Considerable effort has been devoted towards developing alternatives to the use of antibiotics. Objective: to evaluate the effect of propolis or cashew and castor oils on animal performance, feed intake, digestibility, and blood cell counts of young bulls. Methods: bulls were kept in a feedlot for 49 days. Starting on the 40th day, feces were sampled for five days to estimate digestibility using indigestible dry matter (DM) as a marker. Bulls were fed a control diet (CON) with sorghum silage (41% DM) and cracked corn, soybean meal, glycerine, limestone, and mineral salt. The propolis-supplemented group (PRO) received 3 g/animal/d in the concentrate. The essential oils-supplemented group (OIL) received 3 g/animal/d (1.5 g cashew oil + 1.5 g castor oil) added to the concentrate. Results: final body weight, average daily gain and feed efficiency were better for bulls fed the OIL diet. Propolis or essential oils had no effect on feed intake and digestibility. There was no effect of propolis or essential oils on blood cell counts. Red blood cell concentration was greater in the last day of the experiment, while the number of white blood cells was lower. Conclusions: dietary addition of propolis did not affect bull performance or feed efficiency. The addition of essential oils improved performance. Feed intake, digestibility, and blood cell counts were similar in all treatments.Antecedentes: no sistema de produção de bovinos, os antibióticos são fornecidos aos bovinos para prevenir doenças e perturbações metabólicas e melhorar a eficiência alimentar. Consideráveis esforços têm sido realizados para desenvolver produtos alternativos aos antibióticos. Objetivo: avaliar o efeito de produtos alternativos: própolis, óleos de caju e mamona no desempenho animal, ingestão de alimentos, digestibilidade e células sanguíneas de toros jovens. Métodos: os animais foram confinados durante 49 dias. No quadragésimo dia de confinamento, as fezes foram amostradas por cinco dias para determinar a digestibilidade (matéria seca indigestível foi usada como indicador). Os animais foram alimentados com uma dieta controle (CON) com silagem de sorgo (41% da matéria seca) e milho moído, farelo de soja, glicerina, calcário e sal mineral. O grupo própolis (PRO) recebeu 3 g/animal/d dieta. O grupo com óleos essenciais (OIL) receberam 3 g/animal/d (1,5 g de óleo de mamona + 1,5 g de óleo de caju) na dieta. Resultados: o peso final, o ganho médio diário e a eficiência alimentar foram melhores para os animais alimentados com a dieta OIL. Própolis ou óleos essenciais não tiveram efeito na ingestão de alimentos e digestibilidade aparente. Não houve efeito de própolis ou dos óleos essenciais na dieta nos valores de células sanguíneas. A concentração de células vermelhas foi maior no último dia do experimento, enquanto que a concentração de células brancas foi menor. Conclusões: a adição de própolis na dieta dos animais em sistema intensivo de produção não teve efeito sobre o desempenho animal e eficiência alimentar. A adição de óleos essenciais melhorou o desempenho animal. A ingestão de alimentos, digestibilidade e células sanguíneas foram similares em todos os tratamentos
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