300 resultados para COLLAGEN FIBERS


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The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.

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Spindle cell lipoma is a benign lipomatous neoplasm, which rarely occurs in the oral cavity. The aims of this paper are to report a case of spindle cell lipoma located in buccal mucosa and discuss the main clinical, histological, and immunohistochemical findings of this entity. Thus, we report a 4-year history of an asymptomatic smooth surface nodule in an elderly Caucasian man with clinical hypothesis of fibroma. The histopathological examination showed spindle cells, mature adipose tissue, and many mast cells in a stroma of connective tissue presenting ropey collagen fibers bundles. After immunohistochemical analysis, the final diagnosis was spindle cell lipoma.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Accidents caused by thermal, chemical, electrical or radioactive agents cause skin lesions causing burns of varying degrees. The therapeutic approach aims to restore damaged tissues and involves a wide range of products on the market. This study aims to evaluate the use of biological dressing, biotech product developed at the Blood Center of Botucatu / UNESP obtained from fresh frozen plasma or platelet concentrate with in vitro addition of thrombin and calcium gluconate. This addition in the platelet concentrate, intended to release the active growth factors of the platelets granules on the healing process. The study of the effectiveness of Platelet Gel home made in Wistar rats was established, in agreement with scald burns, comparing efficacy and cost of Platelet Gel with usual hospital -based treatment collagenase + chloramphenicol plus cost analysis through pharmacoeconomics. We used 25 Wistar rats were divided into 3 treatment groups: Group A, Collagenase + Chloramphenicol; Group B, Platelet Gel and C, control. The products were applied every other day for 30 days in animals. In group A, there was the presence of erythema and crust in all animals. The exudates was indentified 2/10 animals. For the Group B, we observed the presence of erythema and crust at all and no presence of exudates. In group C all the animals showed erythema with no presence of exudates and scab occurred in 1/10. Statistical analysis showed significant difference ( p < 0.0 ) for crust formation between Groups B and C. In the histological analysis, group A showed a slight amount of blood vessels and collagen fibers, moderate amounts of macrophages and fibroblasts was observed while B and C groups showed moderate amounts of blood vessels, macrophages and fibroblasts and discreet presence of collagen fibers. The re-epithelialization occurred in most animals of all groups without significant statistical differences. For the aspects of pharmacoeconomics, the platelet gel presented a better cost - effectiveness in relation to treatment based on collagenase / chloramphenicol. In light of the ethical aspects of the raw material is the result of spontaneous blood donation, the proposal should have biological dressings productions the responsibility of public blood transfusion centers for free distribution. This may point to the production chain of Brazilian blood banks like special blood components for use no intravenous.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Bases Gerais da Cirurgia - FMB

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Absence of enteric neurons is associated with thickening of the intestinal muscularis externa in Chagas' disease. The thickening is due to hyperplasia and hypertrophy of the smooth muscle cells and increased extracellular matrix components. The influence of the nervous system on the structure of the smooth muscle cells and its associated matrix has been poorly investigated. An experimental model of denervation of the ileum in rats was performed by application of the surfactant agent benzalkonium chloride that selectively destroys the myenteric plexus. Three months later, ileal tissue samples were obtained and studied by histochemistry and transmission electron microsocopy. Sham operated rats were used as controls. The diameter of collagen fibrils was evaluated in electron micrographs. The histopathological analysis showed thickening of the muscular layer. The thin and weakly arranged collagen and reticulin fibers surrounding the smooth muscle cells, observed in control cases by Picrosirius polarization (PSP) stain method, corresponded to a population of loosely packed thin collagen fibrils of uniform diameters (mean = 29.16 nm) at the ultrastructural level. In contrast, the thick and strongly birefringent fibers around the muscle cells, observed in the treated group, stained by PSP, corresponded to densely packed thicker fibrils with large variation in diameter (mean = 39.41 nm). Comparison of the data demonstrated statistically significant difference between the groups suggesting that the replacement of loosely arranged reticulin fibers by fibrous tissue (with typical collagen fiber), may alter the biomechanical function resulting in impairment of muscular contraction. (c) 2007 Elsevier Ltd. All rights reserved.

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In order to observe collagen and elastic fibers simultaneously, sections of human aorta, skin, lung, liver, and bladder were stained by Sirius red and analyzed by fluorescence microscopy. In all cases, the fibers of collagen presented the characteristic fluorescent red-orange color that results from the interaction of this extracellular protein with the dye, whereas elastic fibers showed strong green fluorescence (intrinsic fluorescence). This method efficiently detects collagen and elastic fibers when these two structures are present and could have valuable applications in processes that involves both fibers.