692 resultados para secreção de néctar
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Palestra a convite
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The present study examines the chemical composition and their effects on free radicals, inflammation, angiogenesis, coagulation, VEGF effects and cellular proliferation of a polysaccharides from alga Sargassum vulgare. The sulfated polysaccharide was extracted from brown seaweed by proteolysis with enzymes maxataze. The presence of proteins and sugars were observed in crude polysaccharides. Fractionation of this crude extract was made with growing concentration of acetone (0.3-1.5 v) and produced four groups of polysaccharides. Anionic polysaccharides from brown seaweed Sargassum vulgare, SV1and PSV1 were fractionated (SV1) and purified (PSV1), and displayed with high total sugars and sulfate content and very low level of protein. This fucan SV1 contains low levels of protein and high carbohydrate and sulfate content. This polysaccharides prolonged activated partial thromboplastin time (aPTT) at 50 μg (>240 s). SV1 was found to have no effect on prothrombin time (PT), corresponding to the extrinsic pathway of coagulation. SV1 exhibits high antithrombotic action in vivo, with a concentration ten times higher than heparin. Polysaccharides from S. vulgare promoted direct inhibition enzymatic activity of thrombin and stimulated enzymatic activity of FXa. SV1 showed optimal inhibitory activity of thrombin (50.2±0.28%) at a concentration of 25 μg/mL. Its antioxidant action on scavenging radicals by DPPH was (22%), indicating the polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups and displays strong anti-inflammatory action on all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration. Angiogenesis is a dynamic process of proliferation and differentiation. It requires endothelial proliferation, migration, and tube formation. In this context, endothelial cells are a preferred target for several studies and therapies. The antiangiogenic efficacy of polysaccharides was examined in vivo in the chick chorioallantoic membrane (CAM) model by using fertilized eggs. Decreases in the density of the capillaries were assessed and scored. The results showed that SV1 and PSV1 have an inhibitory effect on angiogenesis. These results were also confirmed by inhibition tubulogenesis in rabbit aorta endothelial cell (RAEC) in matrigel. These compounds were assessed in Apoptosis assay (Annexin V - FITC / PI) and cell viability by MTT assay of RAEC. These polysaccharides do not affect the viability and do not have apoptotic or necrotic action. RAEC cell when incubated with SV1 and PSV1showed inhibition of VEGF secretion, observed when compounds were incubated at 25, 50 and 100 μg/μL. The VEGF secretion with the RAEC cell line for 24 h, was more effective for PSV1 at 50 μg/μL(71.4%) than SV1 100 μg/μL (75.9%). SV1 and PSV1 had an antiproliferative action (47%) against tumor cell line HeLa. Our results indicate that these sulfated polysaccharides have antiangiogenic and antitumoral actions
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La investigación sobre interacciones colibrí-planta se llevó a cabo en el Área Protegida Trinacional Montecristo, entre los meses de abril a agosto de 2013, en dos tipos de hábitat Sub-caducifolio y Ripario, ubicados entre los 730-900 msnm. La metodología comprendió las fases de campo y de laboratorio. Para la realización de los muestreos se seleccionaron dos transectos en el Hábitat Ripario y cuatro en el Hábitat Sub-caducifolio. La fase de campo se realizó mensualmente utilizando las metodologías de Observación directa para comprobar las interacciones y estudiar el comportamiento de los colibríes y la Captura con redes de neblina para obtener los granos de polen y verificar las especies de plantas que los colibríes polinizan. De acuerdo a los resultados obtenidos en el estudio, se identificó una comunidad de colibríes de cinco especies en total, interactuando con 24 especies de plantas de cinco estratos diferentes. El color de las flores o brácteas preferidas por los colibríes para visitar fue el blanco y luego el rojo, no pudiendo cumplirse a cabalidad el síndrome de ornitofilia. Las familias de plantas más representativas importantes para estas aves son la Fabaceae, Bromeliaceae y Rubiaceae. En base a las interacciones registradas entre colibríes y plantas, se identificaron a las especies de colibrí Amazilia beryllina y Chlorostilbon canivetii como generalistas. Asimismo, se identificó a las plantas Pitcairnia imbricata y Cornutia pyramidata como especies generalistas por poseer interacciones con la mayoría de los colibríes registrados. Se capturaron tres especies de colibríes, de los cuales dos fueron identificados como polinizadores, pues estaban acarreando en su cuerpo los granos de polen de tres especies de plantas que presentan síndrome de ornitofilia. Con esta investigación se logró obtener la primera Colección Palinológica para El Salvador de plantas registradas como interactuantes con colibríes. Se determinó una mayor diversidad de colibríes para el hábitat Sub-caducifolio durante la época estudiada en base a curvas de rarefacción del índice de Shannon-Wiener y curvas de acumulación de especies. La relación entre las variables riqueza de colibríes y plantas interactuantes fue mayor en el hábitat Subcaducifolio, asimismo se estableció la relación entre la riqueza de colibríes y palinomorfos. Además se identificó a la especie Amazilia beryllina realizando interacciones depredativas (robo de néctar) en Sanchezia speciosa.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
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Obesity is increasing, reaching epidemic levels in many regions of the world. Studies have shown that consumption of peanuts influences on weight control and this influence may be due to the action of trypsin inhibitors sacietogênica that condition increased plasma colescistocinina (CCK). Moreover, the peanut has other health benefits, and these assignments are guaranteed to increase their production and consumption of several of its products, including the paçoca peanut. The aim of this study was to identify the presence of a trypsin inhibitor in paçoca peanut and evaluate its effect on food intake, weight gain and histomorphological changes in swiss mice (n = 8) and Wistar rats (n = 6). Experimental diets were prepared based on the AIN-93G and supplemented with tack or peanut trypsin inhibitor partially purified paçoca peanut (AHTI). After each treatment, the animals were anesthetized and euthanized, their bloods were collected by cardiac puncture for the determination of CCK and other biochemical parameters (glucose, triglycerides, total cholesterol, high density lipoprotein, low density lipoprotein, glutamic-pyruvic transaminase, glutamic oxaloacetic transaminase and albumin) and their pancreas removed for histologic and morphometric analysis. The supplementation with paçoca peanut and the AHTI showed a decrease of body weight gain and food intake in both mice and rats, due to the satiety, since the animals showed no evidence of impairment of nutritional status conditioned by consumption the AHTI. There were also observed biochemical or morphological important when compared with controls. However, AHTI led to increased secretion of CCK, a peptide sacietogênico. Thus, these results indicate that AHTI present in paçoca peanut, is able to enhance the secretion of plasma CCK and thereby reduce the weight gain associated with lower food intake of experimenta animals
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Dissertação (mestrado)—Universidade de Brasília, Programa de Pós-Graduação em Ciências da Saúde, 2015.
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Chromobacterium violaceum is a free-living bacillus, Gram-negative commonly found in water and sand of tropical and subtropical regions. One of its main characteristic it's the ability to produce the purple pigment named violacein, that shows countless biological activities. In 2003, the genome of this organism was totally sequenced and revealed important informations about the physiology of this bacteria. However, few post-genomics studies had been accomplished. This work evaluated the protein profile of C. violaceum cultivated in LB medium at 28ºC that allowed the identification and characterization of proteins related to a possible secretion system that wasn't identified and characterized yet in C. violaceum, to the quorum sensing system, to regulatory process of transcription and translation, stress adaptation and biotechnological potential. Moreover, the response of the bacteria to UVC radiation was evaluated. The comparison of the protein profile, analyzed through 2-D electrophoresis, of the control group versus the treatment group allowed the identification of 52 proteins that arose after stress induction. The obtained results enable the elaboration of a stress response pathway in C. violaceum generated by the UVC light. This pathway, that seems to be a general stress response, involves the expression of proteins related to cellular division, purine and pirimidine metabolism, heat chock or chaperones, energy supply, regulation of biofilm formation, transport, regulation of lytic cycle of bacteriophages, besides proteins that show undefined function. Despite the response present similarities with the classic SOS response of E. coli, we still cannot assert that C. violaceum shows a SOS-like response, mainly due to the absence of characterization of a LexA-like protein in this organism
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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014
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Tese de Doutoramento em Ciências Veterinárias na especialidade de Sanidade Animal
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Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2014
Multifactorial approach to non-viral gene therapy: development of an efficient system for the retina
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Tese de Doutoramento, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2016
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, Programa de Pós-Graduação em Patologia Molecular, 2016.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Biologia Molecular, 2016.
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Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz
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Butterflies are insects known, in a variety of environments and for easy visual identification. The adult form may be frequently found in flowers looking for nectar. However, for many species of Heliconius (Lepidoptera, Nymphalidae) to visit the flower also represents the collecting of pollen, an important source of protein for adults. The protein obtained from the pollen allows the maintenance of physiological processes that increase the performance of the individual, promoting greater longevity and egg production. For males, proteins can also be part in your investment in reproductive success and fitness of offspring through a nutritional contribution that is transferred to the female in the act of mating as a nuptial present. It is known that this protein contains essential to the performance of the female oviposition, however the proportion of content and specific importance to the monogamous and polygamous species is not known yet. Whereas the species studied in this work have different patterns of mating in the strategy was to verify a significant difference in the quality of the spermatophore, and H. erato and H. melpomene, on the amount of protein present in this structure, indicating a difference in investment between the male reproductive strategies