Navegando por Palavras-chave "histochemistry"
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- ItemSomente MetadadadosHistochemical and ultrastructural study of collagen fibers in mouse pubic symphysis during late pregnancy(Elsevier B.V., 2004-01-01) Pinheiro, M. C.; Moraes, S. G.; Battlehner, C. N.; Caldini, E. G.; Toledo, OMS [UNIFESP]; Joazeiro, P. P.; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Reference is usually made to the parallel orientation towards the main line of exerted tension at the pubic joint in mice, for supporting forces applied to the joint. Despite the wealth of morphological information about the extracellular matrix in this joint, little is known regarding the involvement of the crimp of collagen fibers in the dramatic transformations occurring in this region during the last 3 days of pregnancy. Examination of the collagenous architecture suggests that the biomechanical properties are directly related to fibril diameters, composition of ground substance and changes in the bundle morphology, particularly in the crimp structure. the purpose of this study was to further describe the transformation of the collagen fibers of the pubic symphysis during late mouse pregnancy. We examined the architecture of collagen fibers in the symphysis and pubic ligament through the Picrosirius-polarization method and also through scanning electron microscopy to directly visualize and measure the crimping from pregnant and virgin mice. the crimp angle and the length of five consecutive crimps were measured according to Patterson-Kane et al. [Connect. Tissue Res. 36 (1997) 253]. It could be demonstrated that the angles progressively decreased and the crimp length increased, denoting that the fibers have untwisted during the relaxation process. Our findings suggest that a disruption of the helical arrangement of the collagen containing fibers may contribute to explaining the rapid remodeling that occurs at the end of pregnancy and that is responsible for an increase in pliancy and length of the pubic ligament in mice. (C) 2004 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosHistochemical and ultrastructural study of the extracellular matrix fibers in patellar tendon donor site scars and normal controls(Editrice Compositori Bologna, 1996-04-01) Battlehner, Cláudia Naves; Carneiro Filho, Mario [UNIFESP]; Ferreira Junior, Jorge Mario da Costa; Saldiva, Paulo Hilário Nascimento [UNIFESP]; Montes, Gregorio Santiago; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); BUTANTAN INSTLesions of the anterior cruciate ligament are extremely common and frequently demand surgical treatment in order to avoid disabling sequels. The use of a central one-third of the patellar tendon as an autograft for surgical reconstruction of a damaged cruciate ligament is common. Although several investigations in human and animal models have demonstrated long-term graft viability, there have been cases of loosening and rupture of the graft. In these occasions, a new substitute for the torn structure must be found. Owing to its inherent accessibility, the patellar tendon has been elected one of the choices of donor tissue. In order to evaluate the characteristics of the remaining scar, we performed a histochemical and ultrastructural study using biopsy material obtained from the central one-third of the donor tendon of 8 patients. This material was analyzed by comparing the ultrastructural picture with the results obtained using the specific method for collagen-containing fibers (Picrosirius-polarization) by light microscopy; four normal patellar tendons were used as controls. Despite the resemblance with the normal tissue, our results show that Phr healed tissue does nor restore the tendon ad integrum, neither at the light microscopic nor at the electron microscopic levels. Structural differences can be responsible for biomechanical alterations. Impaired biomechanical properties can, at least partly, explain some of the clinical complications observed in patients submitted to this surgical technique. However, without performing biomechanical studies in this kind of tendons, we are neither allowed to encourage nor to reject the use of scars as donor tissue for a second surgery.
- ItemSomente MetadadadosMorphometry and acetylcholinesterase activity of the myenteric plexus of the wild mouse Calomys callosus(Assoc Bras Divulg Cientifica, 1997-05-01) Maifrino, Laura Beatriz Mesiano [UNIFESP]; Prates, José Carlos [UNIFESP]; DeSouza, R. R.; Liberti, E. A.; Universidade de São Paulo (USP); INST DANTE PAZZANESE CARDIOL; Universidade Federal de São Paulo (UNIFESP)The myenteric plexus of the digestive tract of the wild mouse Calomys callosus was examined using a histochemical method that selectively stains nerve cells, and the acetylcholinesterase (AChE) histochemical technique in whole-mount preparations, Neuronal density was 1,500 +/- 116 neurons/cm(2) (mean +/- SEM) in the esophagus, 8,900 +/- 1,518 in the stomach, 9,000 +/- 711 in the jejunum and 13,100 +/- 2,089 in the colon, The difference in neuronal density between the esophagus and other regions was statistically significant, The neuron profile area ranged from 45 to 1,100 mu m(2). The difference in nerve cell size between the jejunum and other regions was statistically significant. AChE-positive nerve fibers were distributed within the myenteric plexus which is formed by a primary meshwork of large nerve bundles and a secondary meshwork of finer nerve bundles, Most of the nerve cells displayed AChE activity in the cytoplasm of different reaction intensities. These results are important in order to understand the changes occurring in the myenteric plexus in experimental Chagas' disease.
- ItemSomente MetadadadosUltrastructural and biochemical changes of the medial pterygoid muscle induced by unilateral exodontia(Elsevier B.V., 2008-07-01) Bazan, Emmanuel [UNIFESP]; Mardegan Issa, Joao Paulo; Watanabe, Ii-sei; Alberto Mandarim-de-Lacerda, Carlos; Aparecida Del Bel, Elaine; Iyomasa, Mamie Mizusaki; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Universidade do Estado do Rio de Janeiro (UERJ)The aim of the present study was to investigate the histological, biochemical and ultrastructural effects of occlusal alteration induced by unilateral exodontia on medial pterygoid muscle in guinea pigs, Cavia porcellus. Thirty (n = 30) male guinea pigs (450 g) were divided into two groups: experimental-animals submitted to exodontia of the left upper molars, and sham-operated were used as control. the duration of the experimental period was 60 days. Medial pterygoid muscles from ipsilateral and contralateral side were analyzed by histological (n = 10), histochernical (n = 10), and ultrastructural (n = 10) methods. the data were submitted to statistical analysis. When the ipsilateral side was compared to the control group, it showed a significantly shorter neuromuscular spindle length (P < 0.05), lower oxidative metabolic activity, and microvessel constriction, in spite of the capillary volume and surface density were not significantly different (P > 0.05). in the contralateral side, the neuromuscular spindles showed significantly shorter length (P < 0.05), the fibers reflected a higher oxidative capacity, the blood capillaries showed endothelial cell emitting slender sprouting along the pre-existing capillary, and significantly higher blood capillary surface density, and volume density (V-v = 89% Mann-Whitney test, P < 0.05). This finding indicated a complex morphological and functional medial pterygoid muscle adaptation to occlusal alteration in this experimental model. Considering that neuromuscular spindles are responsible for the control of mandibular positioning and movements, the professional should consider if these changes interfere in the success of clinical procedures in medical field involving stomatognathic structures. (c) 2007 Elsevier B.V. All rights reserved.