135 resultados para Strip of ducts


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The salivary glands of termites are composed of several secretory acini connected by ducts. These glands, in the Brazilian termite Serritermes serrifer, were examined through the electron microscope. The ultrastructure of worker salivary acinus revealed central ductule cells and four different types of cells. Cells of type I contain an abundance of electron-lucid vacuoles of various sizes which fuse to form enormous vacuolar structures that fill up most of the cell. Cells of type II are narrow cells in which the secretion is contained in small clear vacuoles of approximately equal diameter. Both of these cellular types have numerous Golgi bodies and rough endoplasmic reticulum. Type III or parietal cells have an apical plasma membrane deeply infolded and lined by microvilli. This type of cell is located in the acinar periphery and occurs in pairs. Cells of type IV are completely filled with electrondense secretion. The secretory granules can be small in some cells or large and similar to fingerprints in others. This is the first report of the occurrence of these spiral or concentric rings of dense material in the salivary gland of Isoptera.

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Purpose: To evaluate the surface roughness and staining of a glass ionomer cement when subjected to different finishing procedures. Materials and Methods: Sixty-four discs of Chem-Fil II glass ionomer cement were submitted to staining test with methylene blue by spectrophotometry and roughness test by profilometry. Four groups were evaluated: Mylar matrix (control), Sof-Lex discs, Enhance points, and diamond bur. Results: Staining and roughness test, analyzed by ANOVA and Tukey's test, showed that the best surface was obtained when the material cured in contact with the Mylar matrix strip or when treated with Sof-Lex discs. The poorest results were obtained after using the diamond bur.

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This work presents the application of a scalar finite element formulation for Ex (TE-like) modes in anisotropic planar and channel waveguides with diagonal permittivity tensor, diffused in both transversal directions. This extended formulation considers explicitly both the variations of the refractive index and their spatial derivates inside of each finite element. Dispersion curves for Ex modes in planar and channel waveguides are shown, and the results compared with solutions obtained by other formulations.

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Several leaf anatomical features are potentially systematically informative within both the family Vochysiaceae and the order Myrtales, notably tracheoidal idioblasts, mucilage cells and secretory canals. Tracheoids with spiral wall thickenings are present in the mesophyll of most species of Vochysia, and also occur in several other families of Myrtales. Mucilage cells are common in the leaf epidermis in some Vochysiaceae. Secretory ducts are present in the midrib in Salvertia and Vochysia, which are apparently closely related, although Salvertia also shares some leaf anatomical characters with Qualea and Callisthene. Anatomical data do not support the segregation of Ruizterania from Qualea; leaves of R. albiflora leaves are very similar to those of Q. paraensis in venation pattern, and leaf and stem anatomy. Different venation patterns are characteristic of sections within the genus Qualea, but within the large genus Vochysia, leaf anatomy is variable even within a subsection. Amongst other Myrtales, leaf anatomy of Vochysiaceae most closely resembles that of Combretaceae and Onagraceae. © 2002 The Linnean Society of London.

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Trichilia catigua A. Juss. - Meliaceae has been traditionally used as a tonic and digestive medicine. Some Brazilian pharmaceutical firms use this species to produce phytopharmaceuticals and alcoholic beverages. The aim of this work is to determine its geographical distribution and characterise the environments where catuaba is found in the state of Paraná, in order to support the domestication strategy for the agricultural production of this species. Based on the literature, botanical collections and field observations it was established, that five species of the genus occurring in Paraná, which were identified as T casaretti, T catigua, T claussenii, T elegans, T pallida and another supposed to be T pattens. Trichilia catigua occurs within a wide but defined strip in the state. By evaluating data of climate; soil types; natural vegetation formations; mean, maximum and minimum temperatures; relative humidity; rainfall; altitudes and evapotranspiration the strip may be localised above latitude 25° in the central and Eastern regions of the state and above latitude 26° in South-western Parana. In general, T catigua was found to occur on fertile, organic-matter-rich soils and predominantly under forest canopies.

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OBJECTIVES: Pleomorphic adenomas are the most frequent type of epithelial salivary gland neoplasms, and their malignant counterpart, the carcinoma in pleomorphic adenomas, is much less common. Beta-catenin is a cell adhesion molecule associated with the invasion and metastasis of carcinomas of the head and neck, esophagus. The objective of this study was to detect the expression of beta-catenin in pleomorphic adenomas, carcinomas in pleomorphic adenomas and normal salivary glands to discuss its role in the development of these two lesions. STUDY DESIGN: The expression of beta-catenin (BD Transduction Laboratories) was analyzed by immunohistochemistry in formalin-fixed, paraffin embedded specimens by the avidin-biotin-peroxidase complex method in 16 pleomorphic adenomas (12 from minor salivary glands), 3 carcinomas in pleomorphic adenomas (all from palate) and 10 normal salivary glands as control group (5 from major and 5 from minor salivary glands). RESULTS: All cases of glands, adenomas and carcinomas in pleomorphic adenomas have membranous and cytoplasmic immunostaining. Nuclear beta-catenin immunostaining was not observed. The antibody presented a fine granular arrangement in the cytoplasm and cellular membrane of duct and acinic cells. Higher beta-catenin index rates were seen mainly in salivary gland ducts and in ductal structures in the adenomas and carcinomas in pleomorphic adenomas. There was protein loss in pleomorphic adenomas and cytoplasmic accumulation in carcinoma in pleomorphic adenomas. CONCLUSIONS: The present study showed participation of the loss of beta-catenin adhesion molecule in the development of pleomorphic adenoma, and that the cytoplasmic accumulation of the molecule takes part in the malignant transformation of the pleomorphic adenoma into carcinoma in pleomorphic adenoma.

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The growth of the mouse parotid glands during 7 and 35 days of postnatal life was studied by morphometric methods. The mass of the gland, the volume of each morphological compartment, and the cell number in each compartment were evaluated. The data obtained for each evaluated dimension were adjusted by an exponential equation, of the type Y = a.e KX, thus permitting the calculation of their mean duplication time (T D), i.e., an estimation of their growth rate. Analysis of the results showed a marked 1,424% increase in the gland mass during the whole studied period, with T D = 7.10 days. This growth occurred by increases in absolute volume of acini, intercalated ducts, striated ducts, excretory ducts and stroma, with percentual increases of 3,048%, 417%, 2,662%, 2,594% and 367%, respectively, and T Ds of 5.62, 11.71, 5.55, 5.47 and 14.45 days, respectively. Analysis of the cell number growth in each compartment showed increases of 1,904%, 285%, 1,228%, 1,090% and 286%, respectively, and T Ds of 6.62, 20.40, 7.19, 7.26 and 14.51 days, respectively. Based on the present results, we concluded that the growth of the mouse parotid glands from day 7 to day 35 of age occurred by intense cell accumulation, mainly in the acini, striated ducts and excretory ducts, with a growth rate sensibly higher than that of the intercalated ducts and stroma.

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Background. Mucocele is a lesion that involves the salivary glands and respective current ducts caused mainly by traumas in the affected area. Two different histological forms can be found: extravasation phenomenon and mucus-retention cyst where the former is the most frequently observed involving minor salivary glands such as the glands present in the anterior portion of the ventral surface of the tongue (glands of Blandin-Nuhn). Case Report. This report describes a large lesion involving the ventral surface of the tongue that was definitively diagnosed by histological examination as extravasation mucocele. Conclusion. Important concepts are reviewed to help clinicians correctly diagnose and treat this pathology. © 2006 The Authors.

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A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven μm-thick histological sections stained with hematoxylin-eosin (HE) and Calleja showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Myosin-Va is a Ca 2+/calmodulin-regulated unconventional myosin involved in the transport of vesicles, membranous organelles, and macromolecular complexes composed of proteins and mRNA. The cellular localization of myosin-Va has been described in great detail in several vertebrate cell types, including neurons, melanocytes, lymphocytes, auditory tissues, and a number of cultured cells. Here, we provide an immunohistochemical view of the tissue distribution of myosin-Va in the major endocrine organs. Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells. Weak to moderate staining has been detected in steroidogenic cells of the adrenal cortex, ovary, and Leydig cells. Myosin-Va has also been localized to non-endocrine cells, such as the germ cells of the seminiferous epithelium and maturing oocytes and in the intercalated ducts of the exocrine pancreas. These data provide the first systematic description of myosin-Va localization in the major endocrine organs of rat. © 2008 Springer-Verlag.

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This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC) activated solely by chemical reaction (control group) or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram) or composite (Artglass) disc. Light curing was carried out using conventional halogen light (XL2500) for 40 s (QTH); light emitting diodes (Ultrablue Is) for 40 s (LED); and Xenon plasma arc (Apollo 95E) for 3 s (PAC). Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height) was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37°C), the samples (n = 5) were sectioned for hardness (KHN) measurements, taken in a microhardness tester (50 gF load 15 s). The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05). The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values. © 2009 Sociedade Brasileira de Pesquisa Odontológica.

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This study evaluated the effect of different light energy densities on conversion degree (CD) and Knoop hardness number (KHN) of RelyX ARC (RLX) resin cement. After manipulation according to the manufacturer's instructions, RLX was inserted into a rubber mold (0.8 mm X 5 mm) and covered with a Mylar strip. The tip of the lightcuring unit (LCU) was positioned in contact with the Mylar surface. Quartz-tungsten-halogen (QTH) and light-emitting diode (LED) LCUs with light densities of 10, 20 and 30 J/cm2 were used to light-cure the specimens. After light curing, the specimens were stored dry in lightproof containers at 37°C. After 24 hours, the CD was analyzed by FT-Raman and, after an additional 24-hours, samples were submitted to Knoop hardness testing. The data of the CD (%) and KHN were submitted to two-way ANOVA and the Tukey's test (α=0.05). QTH and LED were effective light curing units. For QTH, there were no differences among the light energy densities for CD or KHN. For LED, there was a significant reduction in CD with the light energy density set at 10 J/cm2. KHN was not influenced by the lightcuring unit and by its light energy density. © Operative Dentistry.

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Mucocele forms because of salivary gland mucous extravasation or retention and is usually related to trauma in the area of the lower lips. Ruptured ducts release the mucous that accumulates into adjacent tissues, leading to swelling. This report describes a large mucocele involving the lower lip, which was produced in a child by incorrect use of a pacifier. A few important concepts are discussed to help clinicians in the diagnosis and treatment of this pathology. © 2010 Dermatology Online Journal.

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The CMS silicon tracker, consisting of 1440 silicon pixel and 15 148 silicon strip detector modules, has been aligned using more than three million cosmic ray charged particles, with additional information from optical surveys. The positions of the modules were determined with respect to cosmic ray trajectories to an average precision of 3-4 microns RMS in the barrel and 3-14 microns RMS in the endcap in the most sensitive coordinate. The results have been validated by several studies, including laser beam cross-checks, track fit self-consistency, track residuals in overlapping module regions, and track parameter resolution, and are compared with predictions obtained from simulation. Correlated systematic effects have been investigated. The track parameter resolutions obtained with this alignment are close to the design performance. © 2010 IOP Publishing Ltd and SISSA.