4 resultados para Polissacarideos microbianos
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
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
Resumo:
The development of epidemiological practices in the last years of the nineteenth and early twentieth century was characterized by both an influence of medical geography and the emergence of microbes and vectors of diseases. Both theories were used to explain outbreaks in Rio Grande do Norte specially in Natal. In this process were organized new institutions linked to public health, unhealthy spaces and prescribed hygiene measures. The redefinitions of the spaces were linked to updated elements of Hippocratic medicine such as aerism and emphasis on medical topography. How the physicians of the town were organized in the face of new meanings and fields of expertise in the demarcation of diseases and regulation of their own practices against the illegal medical practitioners? Likewise, the very occurrence of epidemics mobilized people, urban institutions and apparatuses. But how the Hippocratic legacy that leads to the idea of bad air originated by swamps from the eighteenth and nineteenth century has been linked to new microbial assumptions and disease vectors in the early twentieth century? How an invader from Africa, (the mosquito A. gambiae) mobilized transnational efforts to combat malaria and redefined the epidemiological practices? The aim of this work is to understand how epidemiological practices redefine the way we define spaces, practices and disease from both an approach influenced by a relational history of spaces and a theoretical synergy which includes topics in Science Studies, Post Structuralist Geography and some elements of Feminist Studies. Documentary research were surveyed in the reports of the provincial presidents, government posts to the Provincial Assembly, specialized medical articles and theses, and documents from the Rockefeller Foundation and national and international journals. In this regard shall be given to both material and discursive aspects of space-related practical epidemiological that Natal as much (in general) Rio Grande do Norte between bad air and malaria.
Resumo:
Periodontal disease is a complex inflammatory and infectious condition that immune host, front of the microbial aggressions, can lead to disease progression, resulting in tissue destruction. The tissue damage induces the release of regulatory molecules, which protective roles and / or destructive, including proteins VEGF (vascular endothelial growth factor vascular) and HIF-1 α (hypoxia-induced factor α -1). Thus, this study investigated, quantitatively and comparatively, the immunohistochemical expression of VEGF (vascular endothelial growth factor) and HIF-1 α (hypoxia induced factor 1-α), proteins involved in inflammation, angiogenesis and hypoxia, in human gingival tissues. Therefore, 75 samples of gingival tissues were examined. Thirty samples were chronic periodontitis, 30 with chronic gingivitis and 15 healthy gingival. After sections analysis, positives and negatives inflammatory and endothelial cells in the connective tissue were counted and converted into percentage. Data were statistically analyzed using Kruskal-Wallis test and Spearman correlation. The results showed that both proteins marked. It was observed higher immunoreactivity for HIF-1 α at chronic gingivitis and periodontitis specimens compared to healthy sites, however, no statistically significant differences were observed among them (p>0.05). The VEGF immunostaining showed similarity among the cases of periodontitis, gingivitis and healthy gingiva. Moderate and positive correlation statistically significant differences were verified for the expressions of VEGF and HIF-1α in gingival health (r = 0,529, p = 0.04). Thus, it can be conclude that possibly the route of HIF-1 α, is activated in periodontal disease may have involvement of the protein in pathogenesis and progression of disease, and that activation of VEGF, can be in addition to being triggered transcription by HIF-1 α may be also influenced by other additional factors such as the action of periodontal microorganisms endotoxins
Resumo:
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
