990 resultados para Polarized-light microscopy


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Natural or synthetic materials may be used to aid tissue repair of fracture or pathologies where there has been a loss of bone mass. Polymeric materials have been widely studied, aiming at their use in orthopaedics and aesthetic plastic surgery. Polymeric biodegradable blends formed from two or more kinds of polymers could present faster degradation rate than homopolymers. The purpose of this work was to compare the biological response of two biomaterials: poly(L-lactic acid)PLLA and poly(L-lactic acid)PLLA/poly(ethylene oxide)PEO blend. Forty four-week-old rats were divided into two groups of 20 animals, of which one group received PLLA and the other PLLA/PEO implants. In each of the animals, one of the biomaterials was implanted in the proximal epiphysis of the right tibia. Each group was divided into subgroups of 5 animals, and sacrificed 2, 4, 8 and 16 weeks after surgery, respectively. Samples were then processed for analysis by light microscopy. Newly formed bone was found around both PLLA and PLLA/PEO implants. PLLA/PEO blends had a porous morphology after immersion in a buffer solution and in vivo implantation. The proportion 50/50 PLLA/PEO blend was adequate to promote this porous morphology, which resulted in gradual bone tissue growth into the implant.

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In order to investigate the occurrence of Hepatozoon infection in Neotropical felids from Brazil, blood from the jugular or cephalic vein was taken from 29 non-domestic felids including ocelot (Leopardus pardalis), little spotted cat (Leopardus tigrinus), margay (Leopardus wiedii), and jaguarondi (Puma yagouaroundi) from the Northeast region of Brazil. Hepatozoon infection was confirmed by light microscopy and molecular techniques. The results showed five naturally infected felids. Partial sequences of the 18S rRNA gene of the Hepatozoon sp. from these felids were further analyzed. Sequences revealed that the isolates found are closely related to Hepatozoon sp. from domestic cats in Spain. Hepatozoon species from Neotropical felids were identified molecularly and characterized for the first time. This is also the first report of Hepatozoon infection in a little spotted cat. (C) 2007 Elsevier B.V. All rights reserved.

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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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The aim of this study was to describe the morphology, morphometry and ultrastructure of segments of thoracic and abdominal aorta portions in four male and female paca (Cuniculus paca). Parts of the segments were examined by light microscopy and part by scanning electron microscopy. Thickness measurements of the tunica intima and media complex and tunica adventitia of the aorta were taken. In all animals the thickness values for the tunica intima and media complex of the cranial thoracic aorta were significantly higher (mean: 702.19 mu m) when compared to the values of other aortic segments analyzed (means: 354.18 mu m; 243.55 mu m). The layers of the vessel walls show variations in structure and thickness, presumably due to an adaptation to functionaldemand.

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

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Barreto R.S.N., Miglino M.A., Meirelles F.V., Visintin J.A., Silva S.M., Burioli K.C., Fonseca R., Bertan C., Assis Neto A.C. & Pereira F.T.V. 2009. [Characterization of the caruncular fusion in gestations of natural and cloned bovine conceptuses.] Caracterizacao da fusao caruncular ern gestacoes naturais e de conceptos bovinos clonados. Pesquisa Veterinaria Brasileira 29(10):779-787. Laboratorio de Morfofisiologia da Placenta e Embriao, Faculdade de Zootecnia, Universidade Estadual Paulista, SP294 Km 651, Dracena, SP 17900-000, Brazil. E-mail: fverechia@dracena.unesp.brThe objective of the study was to compare the characteristics of the caruncular fusion in gestations of non-cloned and cloned conceptuses. The non-cloned conceptuses were divided according to the gestation period: Group 1 (2 to 3 months; n=9),II (4 to 6; n=9); III (7 to 8; n=10) and IV (9 n=7). The cloned conceptuses formed the Group V: 9 months; n=4. The caruncles were observed macroscopically (number and dimensions: length, width and height), microscopically and submitted to statistical analysis (5% of significance). We observed three types of macroscopic caruncular fusions: oval (morphologically normal); two united adjacent caruncles and the lobulated type, characterized by regions with several united caruncles presenting a false fusion or deformation of the caruncular parenchyma. The length of the caruncles was 1.55 +/- 0.57; 2.45 +/- 0.55; 4.66 +/- 2.0 and 5.72 +/- 1.90cm for the groups 1, 11, 111, IV respectively. As for the height, the caruncles presented a lineal growth during the gestation: 0.40 +/- 0.15; 0.57 +/- 0.21; 1.0 +/- 0.48 and 1.80 +/- 0.91cm, for the respective groups 1, 11, 111 and IV. The width of the caruncles was similar between the groups I and 11 (0.97 +/- 0.30 e 1.42 +/- 0.71 cm) and the groups III and IV (2.68 +/- 1.22 and 3.52 +/- 1.16cm). When the group V was compared to the IV, the caruncles of the group V presented a larger length (5.72 +/- 1.90 vs. 7.88 +/-.13cm) and width (3.52 +/- 1.16 vs. 4.93 +/- 1.46cm), however they were similar in height (1.80 +/- 0.91 and 2.25 +/- 0.67cm). We verified that in gestations of cloned conceptuses the caruncles presented a larger development than in gestations of non-cloned conceptuses. The fusioned caruncles presented measurements statistically similar to the isolated ones in all the parameters and groups. Under light microscopy, we observed the formation of a stromal axis from the basis of the caruncle to the apex of the fusional fissure, with the histological constitution similar to the endometrial stroma. Three microscopic shapes were also unpublished defined: true fusion with a single axis evident below the fusional fissure; pseudofusion with a double axis in H shape and false fusion with absence of the axis. The first two formats were associated to the oval and lobulated caruncles and the last one to the false fusion with deformation of the caruncle parenchyma. The fusional axis increased in size along the gestation among the groups I, II, III and IV. The group V presented a larger length and width of the axis when compared to the group IV. Thus, in gestations of cloned conceptuses a destruction of the lateral epithelium of the caruncles is associated to an incompetence in the maternal-fetal interdigitation, that compromises the cotyledonary fusion. We suggest that, in gestations derived of cloned conceptuses, the increase of the size of the caruncular fusions is possibly associated to a compensatory mechanism for the metabolic exchanges between mother and fetus, in reason of the smallest number of isolated caruncles.

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The elements related to the morphology of the liver of paca (Cuniculus paca), the second largest rodent of the Brazilian fauna, were observed; this species present zootechnical potential. Eight animals from the animals sector of Faculdade de Ciencias Agrarias e Veterinarias - Campus of Jaboticabal - UNESP, which is duly certified by IBAMA as an experimental breeding institute, were used. Through a dissection procedure, it was found that the liver of the paca is located in the cranial portion of the abdomen, immediately after the diaphragm, to which it is connected by the triangular, coronary, and falciform ligaments, having its bigger part located right to the medium plan. The liver of this rodent presents the following lobation: right lateral lobe, right medial lobe, quadrate lobe, left medial lobe, and left lateral lobe, besides the caudate lobe formed by the papillary process of caudate lobe and the caudate process of caudate lobe. Gallbladder is located between the quadrate and right medial lobes. Fragments of this organ were collected, fixed, and histologically prepared, being the samples analyzed through light microscopy. It was microscopically observed that intralobular connective tissue is scarce, basically it consists polyhedral hepatocytes organized into cords interposed between sinusoids and the portal triads are found in the lobe, consisting of the portal vein, hepatic artery, and biliary duct.

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Cholesteryl ester storage disease (CESD) is a rare disorder of familial incidence characterized by the accumulation of cholesteryl ester and triglycerides in the liver, intestine and bone marrow. Until now only 21 cases have been reported in the literature. We present a 9 months old girl presenting with increased abdominal girth. She had normal liver function tests and increased cholesterol and triglycerides serum levels. The liver biopsy showed many cholesterol cristals seen as needle shaped cristals under polarized light. This is the youngest patient being diagnosed clinically in the literature.

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Two cases of polymorphous low-grade adenocarcinoma of the papillary type, from minor salivary glands were studied by light microscopy and immunohistochemistry. One case exhibited a predominance of the papillary pattern, whereas the other presented the following patterns of histological appearance: papillary, solid, pseudocystic and tubular. Utilizing the peroxidase-antiperoxidase (PAP) method, the intermediate filament vimentin, keratin and S100 protein were observed in tumor cells. The immunohistochemical analysis revealed two types of neoplastic cells: myoepithelial and luminal.

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This study was conducted to observe the rat subcutaneous connective tissue reaction to the implanted dentin tubes filled with calcium hydroxide or mineral trioxide aggregate. The animals were sacrificed after 7 and 30 days, and the specimens were prepared for morphological study. Some undecalcified specimens were prepared for histological analysis with polarized light and Von Kossa technique for calcium. The results were similar for both studied materials. At the tube openings, there were Von Kossa-positive granules that were birefringent to polarized light. Next to these granulations, there was an irregular tissue like a bridge that was Von Kossa-positive. The dentin walls of the tubes exhibited in the tubules a structure highly birefringent to polarized light, usually like a layer and at different depths. It is possible that the mechanism of action of both materials has some similarity. Copyright © 1999 by The American Association of Endodontists.

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Objectives: Evaluate the cytotoxic effect of the three dental adhesive systems. Methods: The immortalized mouse odontoblast cell line (MDPC-23) was plated (30,000 cell/cm 2) in 24 well dishes, allowed to grow for 72 h, and counted under inverted light microscopy. Uncured fresh adhesives were added to culture medium to simulate effects of unset adhesive. Three adhesives systems were applied for 120 min to cells in six wells for each group: Group 1) Single Bond (3M), Group 2) Prime & Bond 2.1 (Dentsply), and Group 3) Syntac Sprint (Vivadent). In the control group, PBS was added to fresh medium. The cell number was counted again and the cell morphology was assessed under SEM. In addition, the adhesive systems were applied to circles of filter paper, light-cured for 20 s, and placed in the bottom of 24 wells (six wells for each experimental materials and control group). MDPC-23 cells were plated (30,000 cell/cm 2) in the wells and allowed to incubate for 72 h. The zone of inhibition around the filter papers was measured under inverted light microscopy; cell morphology was evaluated under SEM; and the MTT assay was performed for mitochondrial respiration. Results: The fresh adhesives exhibited more toxic (cytopathic effects) to MDPC-23 cells than polymerized adhesives on filter papers, and as compared to the control group. The cytopathic effect of the adhesive systems occurred in the inhibition zone around the filter papers, which was confirmed by the MTT assay and statistical analysis (ANOVA) combined with Fisher's PLSD test. In the control group, MDPC-23 cells were dense on the plastic substrate and were in contact with the filter paper. In the experimental groups, when acid in the adhesive systems was removed by changing the culture medium, or when the adhesives were light-cured, some cells grew in the wells in spite of the persistent cytotoxic effect. Significance: All dentin adhesive systems were cytotoxic odontoblast-like cells. Both acidity and non-acidic components of these systems were responsible for the high cytopathic effect of those dental materials. © 1999 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.

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The objective of the present study was to analyze the prospective alterations of the testis and epididymis in a defined strain of alcoholic rats in order to contribute to our understanding of the effects of chronic alcoholism on reproduction. The testis and epididymis of the animals were submitted to morphological analysis by macroscopy, light microscopy and electron microscopy and to morphometric analysis. The UCh rats showed atrophy of the epithelium and reduction of testis and epididymis weight, liver hypertrophy and fat infiltration and alterations of the hypothalamus-pituitary axis. Ethanol induces changes in the weight and in the epithelium of the testis and epididymis and in the hypothalamus-pituitary axis of the UCh rats.

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To study translocation of Xylella fastidiosa to citrus rootstocks, budsticks from citrus variegated chlorosis (CVC)-affected cv. Pera sweet orange (Citrus sinenesis (L.) Osb.) were top grafted on 15 citrus rootstocks. Disease symptoms were conspicuous 3 months later on all 15 rootstocks tested. The presence of X. fastidiosa was confirmed by light microscopy, double-antibody sandwich enzyme-linked immunosorbent assays, and polymerase chain reaction in rootlets and main roots of CVC-symptomatic Pera sweet orange in 11 of the 15 rootstocks tested. These results suggest that bacterial translocation from the aerial plant parts to the root system occurs but is not essential for X. fastidiosa to induce symptoms in the aerial parts. Bacterial translocation to the roots was not correlated with CVC leaf-symptom severity in the Pera scion. To determine if CVC disease could be transmitted by natural root grafts, two matched seedlings of each of four sweet orange cultivars (Pera, Natal, Valencia, and Caipira) were transplanted into single pots. One seedling rootstock of each pair was inoculated by top grafting with a CVC-contaminated budstick while the other seedling rootstock was cut but not graft inoculated. Transmission of X. fastidiosa from an inoculated plant to a noninoculated plant sharing the same pot was observed in all four sweet orange cultivars tested. Transmission was confirmed by observation of natural roots grafts between the two plants, presence of X. fastidiosa in the root grafts, and disease development in the uninoculated plants. This is the first report of transmission of CVC disease through natural root grafts.

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The purpose of the study was to evaluate the biocompatibility of two current adhesive resins and a calcium hydroxide cement. Fifty-four polyethylene tubes were filled with these dental materials, which were hand-mixed or light-cured according to the manufacturer's directions: group 1-Clearfill Liner Bond 2 (Kuraray); group 2-Single Bond (3M); and group 3-calcium hydroxide cement (Dycal-Dentsply). The materials were implanted into dorsal connective tissue of rats, which were killed 7, 30, and 60 days after the implantation procedure. The implant sites were excised, immersed in buffered Karnovsky's fixative, and processed using routine histological techniques. Sections of 6 μm thickness were stained with hematoxylin and eosin and assessed under light microscopy. Both adhesive resins at 7 days elicited a moderate/intense inflammatory reaction that decreased over time. Fibrous capsules surrounding the tubes were observed at 30 days. Half of the samples in groups 1 and 2 showed thin fibrous capsule formation containing macrophages, capillaries, lymphocytes, fibroblasts, and collagen fibers. Connective tissue healing was observed even though many specimens exhibited a persistent inflammatory reaction mediated by macrophages and giant cells at the 60-day evaluation. Dycal allowed complete healing at 30 days with only a thin fibrous capsule. In conclusion, all experimental materials were successfully walled off by the connective tissue of the rat. However the adhesive resins may release particulates that may, in turn, induce a persistent local inflammatory reaction. Consequently, in this specific condition, these materials cannot be regarded as biocompatible. Dycal was less irritating than the adhesive resins and was better tolerated by the connective tissue. Copyright © 2000 by The American Association of Endodontists.