989 resultados para Marina Silva
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The analysis of both morphogenetic and structural characteristics of pasture allows us to understand the response patterns of the plant to the environment. Thus, this study was conducted to evaluate the associations between the morphogenetic and structural characteristics of Brachiaria decumbens under continuous grazing by cattle. The development of individual tillers in pastures was evaluated under two grazing management strategies during three seasons (winter, spring and summer). Pearson correlations between variables were estimated. The lengths of leaf and stem, number of tillers and leaves per tiller, rates of leaf appearance and elongation of leaf and stem of B. decumbens were positively correlated. There was a negative relationship between appearance and lifespan of leaves (r = -0.89). However, positive correlations between leaf appearance rate and number of tillers (r = 0.64) and between length of stem and leaf senescence rate (r = 0.63) were determined. The B. decumbens modifies its morphogenesis to better adapt to climate and grazing management.
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This work evaluated the effects of high moisture silage, extrusion and corn and sorghum drying with and without tannin, on the chemical composition and ruminal digestion of dry matter. The experimental design was completely randomized in 3x3 factorial scheme (kinds of grains: processing), for the chemical composition and degradability and three blocks (animals) through in situ method. It was verified significant difference between kinds of grains and processing in relation to the chemical composition, except for crude protein and mineral matter. The contents of etherextract in the three types of grains, were reduced significantly with the high moisture silage, extrusion and drying in relation to the humid material. For the contents of phenols, total and condensed tannin there was effect of hybrid, processing and interaction, and the most elevated contents were found in sorghum with tannin. Although grain composition has been similar, the interaction in ruminal ambient associated to the tannin, promoted differences in the dry matter degradability. It was concluded that sorghum without tannin may be ensiled or extruded, while the sorghum with tannin, must be extruded to improve the degradability and availability of nutrients.
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In order to evaluate the effects of replacement of dried corn (GSM) for silage moisture corn (HMCS) on production and milk composition were used five Holstein cows, primiparous with a mean of 112 days post delivery, confined in Tie Stall, for 70 days. We used five diets according to NRC to 17.5% CP (DM) and 2.4 Mcal / kg DM, the 40:60 ratio of roughage and concentrate containing soybean meal, sugar cane silage and hay and substitution levels of the GSM HMCS the following treatments: a) 0%, 2) 25%, 3) 50%, 4) 75% and 5) 100%. Milk production and dry matter intake (DMI) were recorded daily. The animals were milked daily 6:00 and 18:00 h, and milk samples collected from consecutive milkings of each experimental period of 14 days (four days of collection). The experimental design was a 5x5 Latin square and the data analyzed by the statistical program SAS. Body weight (508 kg), milk (23.6 kg), corrected milk (22.7 kg), DMI (17.13 kg) showed no significant difference, but the intakes of neutral detergent fiber (6.67 kg), and detergent acid (3.39 kg), feed efficiency for the production of milk (milk 1.41 kg / day) urea nitrogen (17.67 mg / dL) differ, thus indicating that HMCS is more efficient than GSM in the diet of dairy cows not alter the production and milk composition.
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Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26 ± 2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38 ± 4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44 ± 3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P < 0.01). Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis. © 2013 Yvana Cristina Jorge et al.
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We have previously shown that the subunit 1 of Leishmania amazonensis RPA (LaRPA-1) alone binds the G-rich telomeric strand and is structurally different from other RPA-1. It is analogous to telomere end-binding proteins described in model eukaryotes whose homologues were not identified in the protozoan's genome. Here we show that LaRPA-1 is involved with damage response and telomere protection although it lacks the RPA1N domain involved with the binding with multiple checkpoint proteins. We induced DNA double-strand breaks (DSBs) in Leishmania using phleomycin. Damage was confirmed by TUNEL-positive nuclei and triggered a G1/S cell cycle arrest that was accompanied by nuclear accumulation of LaRPA-1 and RAD51 in the S phase of hydroxyurea-synchronized parasites. DSBs also increased the levels of RAD51 in non-synchronized parasites and of LaRPA-1 and RAD51 in the S phase of synchronized cells. More LaRPA-1 appeared immunoprecipitating telomeres in vivo and associated in a complex containing RAD51, although this interaction needs more investigation. RAD51 apparently co-localized with few telomeric clusters but it did not immunoprecipitate telomeric DNA. These findings suggest that LaRPA-1 and RAD51 work together in response to DNA DSBs and at telomeres, upon damage, LaRPA-1 works probably to prevent loss of single-stranded DNA and to assume a capping function.
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Background: Although hypercaloric interventions are associated with nutritional, endocrine, metabolic, and cardiovascular disorders in obesity experiments, a rational distinction between the effects of excess adiposity and the individual roles of dietary macronutrients in relation to these disturbances has not previously been studied. This investigation analyzed the correlation between ingested macronutrients (including sucrose and saturated and unsaturated fatty acids) plus body adiposity and metabolic, hormonal, and cardiovascular effects in rats with diet-induced obesity. Methods: Normotensive Wistar-Kyoto rats were submitted to Control (CD; 3.2 Kcal/g) and Hypercaloric (HD; 4.6 Kcal/g) diets for 20 weeks followed by nutritional evaluation involving body weight and adiposity measurement. Metabolic and hormonal parameters included glycemia, insulin, insulin resistance, and leptin. Cardiovascular analysis included systolic blood pressure profile, echocardiography, morphometric study of myocardial morphology, and myosin heavy chain (MHC) protein expression. Canonical correlation analysis was used to evaluate the relationships between dietary macronutrients plus adiposity and metabolic, hormonal, and cardiovascular parameters. Results: Although final group body weights did not differ, HD presented higher adiposity than CD. Diet induced hyperglycemia while insulin and leptin levels remained unchanged. In a cardiovascular context, systolic blood pressure increased with time only in HD. Additionally, in vivo echocardiography revealed cardiac hypertrophy and improved systolic performance in HD compared to CD; and while cardiomyocyte size was unchanged by diet, nuclear volume and collagen interstitial fraction both increased in HD. Also HD exhibited higher relative β-MHC content and β/α-MHC ratio than their Control counterparts. Importantly, body adiposity was weakly associated with cardiovascular effects, as saturated fatty acid intake was directly associated with most cardiac remodeling measurements while unsaturated lipid consumption was inversely correlated with these effects. Conclusion: Hypercaloric diet was associated with glycemic metabolism and systolic blood pressure disorders and cardiac remodeling. These effects directly and inversely correlated with saturated and unsaturated lipid consumption, respectively. © 2013 Oliveira Junior et al.; licensee BioMed Central Ltd.
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Twenty-five specimens of the freshwater red alga Compsopogon were collected from locations in North America, South America, Europe, Asia, Australasia and Oceania, and from an aquarium, with the goal of determining genetic diversity among specimens and ascertaining the number of phylogenetic species. Specimens were morphologically identified as having either the 'caeruleus' morphology, with regular polyhedral cortical cells, or the 'leptoclados' morphology, with irregular cortical cells with rhizoidal outgrowths. The 'leptoclados' morphology has been used by some researchers to distinguish the genus Compsopogonopsis from Compsopogon, or at least to distinguish C. leptoclados from other Compsopogon species. Sequence data for the rbcL gene and cox1 barcoding region were obtained for most specimens. In addition, SSU and partial LSU (barcode) rDNA were explored for a few specimens, but all sequences were identical. For the 25 newly generated and eight previously published rbcL gene data, there were seven unique haplotypes, but the sequence divergence was very low (≤7 bp, ≤ 0.7%). One haplotype was widespread, represented by 21 specimens from diverse locations in all regions sampled. Likewise, the 22 new and one previously published cox1 barcode region sequences yielded seven unique haplotypes with little sequence divergence (≤13 bp, ≤ 2.0%). One haplotype was widespread, being shared among 16 specimens from all regions. The combined molecular and morphological data showed no genetic differentiation between the 'caeruleus' and 'leptoclados' morphologies. The ubiquitous distribution of Compsopogon in tropical/subtropical regions and its low genetic variation are probably facilitated by the alga's ability to tolerate a wide range of stream conditions and its propagation via asexual spores. Given the findings of previous culture-based studies, morphometric research and field observations, coupled with the results of our study, we conclude there is only a single monospecific genus worldwide and that the species is correctly called C. caeruleus, since this is the oldest validly published name; all other previously described species of Compsopogon and Compsopogonopsis are synonyms. © 2013 British Phycological Society.
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Ethnopharmacological relevance Dragon's blood is a dark-red sap produced by species from the genus Croton (Euphorbiaceae), which has been used as a famous traditional medicine since ancient times in many countries, with scarce data about its safe use in humans. In this research, we studied genotoxicity and clastogenicity of Croton palanostigma sap using the comet assay and micronucleus test in cells of mice submitted to acute treatment. Material and methods HPLC analysis was performed to identify the main components of the sap. The sap was administered by oral gavage at doses of 300 mg/kg, 1000 mg/kg and 2000 mg/kg. For the analysis, the comet assay was performed on the leukocytes and liver cells collected 24 h after treatment, and the micronucleus test (MN) on bone marrow cells. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). Results and conclusion The alkaloid taspine was the main compound indentified in the crude sap of Croton palanostigma. The results of the genotoxicity assessment show that all sap doses tested produced genotoxic effects in leukocytes and liver cells and also produced clastogenic/aneugenic effects in bone marrow cells of mice at the two higher doses tested. The PCE/NCE ratio indicated no cytotoxicity. The data obtained suggest caution in the use of Croton palanostigma sap by humans considering its risk of carcinogenesis. © 2013 Elsevier B.V. All rights reserved.
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Vaccinia virus (VACV), the etiological agent of an exanthematic disease, has been associated with several bovine outbreaks in Brazil since the end of the global vaccination campaign against smallpox. It was previously believed that the vaccine virus used for the WHO global campaign had adapted to an unknown wild reservoir and was sporadically re-emerging in outbreaks in cattle and milkers. At present, it is known that Brazilian VACV is phylogenetically different from the vaccinia virus vaccinal strain, but its origin remains unknown. This study assessed the seroprevalence of orthopoxviruses in domestic and wild animals and farmers from 47 farms in three cities in the southwest region of the state of São Paulo with or without official reports of outbreaks in cattle or humans. Our data indicate a low seroprevalence of antibodies in wild animals and raise interesting questions about the real potential of wild rodents and marsupials as VACV reservoirs, suggesting other routes through which VACV can be spread. © 2013 The Author(s).
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Background: Although skeletal muscle atrophy and changes in myosin heavy chain (MyHC) isoforms have often been observed during heart failure, their pathophysiological mechanisms are not completely defined. In this study we tested the hypothesis that skeletal muscle phenotype changes are related to myogenic regulatory factors and myostatin/follistatin expression in spontaneously hypertensive rats (SHR) with heart failure. Methods: After developing tachypnea, SHR were subjected to transthoracic echocardiogram. Pathological evidence of heart failure was assessed during euthanasia. Age-matched Wistar-Kyoto (WKY) rats were used as controls. Soleus muscle morphometry was analyzed in histological sections, and MyHC isoforms evaluated by electrophoresis. Protein levels were assessed by Western blotting. Statistical analysis: Student's t test and Pearson correlation. Results: All SHR presented right ventricular hypertrophy and seven had pleuropericardial effusion. Echocardiographic evaluation showed dilation in the left chambers and left ventricular hypertrophy with systolic and diastolic dysfunction in SHR. Soleus weight and fiber cross sectional areas were lower (WKY 3615±412; SHR 2035±224 μm2; P < 0.001), and collagen fractional volume was higher in SHR. The relative amount of type I MyHC isoform was increased in SHR. Myogenin, myostatin, and follistatin expression was lower and MRF4 levels higher in SHR. Myogenin and follistatin expression positively correlated with fiber cross sectional areas and MRF4 levels positively correlated with I MyHC isoform. Conclusion: Reduced myogenin and follistatin expression seems to participate in muscle atrophy while increased MRF4 protein levels can modulate myosin heavy chain isoform shift in skeletal muscle of spontaneously hypertensive rats with heart failure. © 2012 Elsevier B.V.
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