17 resultados para oval

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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Background/Aims: Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC. Methods: Adult Sprague-Dawley rats, weighing 250-300 g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM). Results: US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells. Conclusions: This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy. (C) 2008 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

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Purpose: To evaluate the cement thickness around oval and circular posts luted in oval post spaces prepared with different drills/tips. Methods: Extracted premolars were endodontically treated and obturated, then randomly divided into three groups (n = 5) according to the tips/drills used for post-space preparation and to the type of fiber post luted: medium grit oval tip + oval posts, fine grit oval tip + oval posts, Mtwo Post File drill + circular posts. The specimens were sectioned in horizontal slices; one slice per canal third was chosen for each post-space, resulting in three slices for each specimen. The distances between the canal wall and the post perimeter were measured on SEM images of each slice. Results: The fine grit tip + oval post group obtained statistically significant lower cement thicknesses than the other groups (P < 0.05), in particular in the apical third. The MtwoPF + circular post group showed the highest cement thickness, comparable to that of the medium tip + oval post group. A good post fitting in oval-shaped canals can be obtained using a fine grit oval tip combined with oval posts. (Am J Dent 2009;22:290-294).

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This study evaluates the effect on post space debridement in oval-shaped canals of an experimental ultrasonic tip with oval section (Satelec) compared with a circular ultrasonic tip (KaVo). Thirty teeth with an oval-shaped canal were endodontically treated and obturated and then randomly divided into 3 groups (n = 10) according to the procedure used for post space debridement: Satelec tip, Largo #2 drill + KaVo file, and Largo #2 drill + water. Debris and dentin tubules were evaluated by assigning scores to scanning electron microscope post spaces images; lower scores corresponded to fewer debris and higher number of open tubules. The Satelec group showed significantly lower debris and open tubules scores than KaVo group (p < .05) and control group (p < .05), which differed significantly between each other (p < .05). Also the debris and open tubules scores in different post space regions differed significantly among the experimental groups (p < .001). The oval ultrasonic tip resulted in a better post space debridement than a circular ultrasonic tip in oval-shaped canals.

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Introduction: The aim of this study was to evaluate the root canal preparation in flat-oval canals treated with either rotary or self-adjusting file (SAF) by using micro-tomography analysis. Methods: Forty mandibular incisors were scanned before and after root canal instrumentation with rotary instruments (n = 20) or SAF (n = 20). Changes in canal volume, surface area, and cross-sectional geometry were compared with preoperative values. Data were compared by independent sample t test and chi(2) test between groups and paired sample t test within the group (alpha = 0.05). Results: Overall, area, perimeter, roundness, and major and minor diameters revealed no statistical difference between groups (P > .05). In the coronal third, percentage of prepared root canal walls and mean increases of volume and area were significantly higher with SAF (92.0%, 1.44 +/- 0.49 mm(3), 0.40 +/- 0.14 mm(2), respectively) than rotary instrumentation (62.0%, 0.81 +/- 0.45 mm(3), 0.23 +/- 0.15 mm2, respectively) (P < .05). SAF removed dentin layer from all around the canal, whereas rotary instrumentation showed substantial untouched areas. Conclusions: In the coronal third, mean increases of area and volume of the canal as well as the percentage of prepared walls were significantly higher with SAF than with rotary instrumentation. By using SAF instruments, flat-oval canals were homogenously and circumferentially prepared. The size of the SAF preparation in the apical third of the canal was equivalent to those prepared with #40 rotary file with a 0.02 taper. (J Endod 2011;37:1002-1007)

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Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

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Folhas de Myrcia multiflora (Lam.) DC. são usadas na medicina popular como hipoglicemiantes. O objetivo deste trabalho foi caracterizar morfológica e anatomicamente as folhas desta planta, de modo que os dados obtidos possam ser utilizados como referência em exames de controle de qualidade de amostras de fármacos, com vistas a verificar a autenticidade. Folhas inteiras foram diafanizadas e coradas para o estudo da nervação. Secções transversais do pecíolo e transversais e paradérmicas da lâmina foliar foram analisadas em microscópio óptico (MO) e a superfície do limbo foi observada, também, em microscopia eletrônica de varredura (MEV). Foram aplicados testes histoquímicos em material fresco, para identificação e localização de glicídios, amido, taninos, lignina, cristais e sílica. Morfologicamente, a folha é simples, oval-elíptica, com margem inteira, base aguda, ápice acuminado e textura cartácea. A venação é do tipo camptódromo-broquidódromo. Anatomicamente, a folha é hipostomática, com mesofilo compacto e dorsiventral, com três estratos de parênquima paliçádico. A epiderme é uniestratificada, silicificada em algumas regiões e as células exibem paredes anticlinais retas. Em posição subepidérmica ocorrem numerosas cavidades secretoras de óleos essenciais. Os feixes vasculares são colaterais e acompanhados por séries cristalíferas. Os dados obtidos são comparados com os de outras espécies de Myrtaceae e conclui-se que as características morfológicas e anatômicas de M. multiflora contribuem para a diagnose.

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Potamotrygon tatianae sp. nov., is described from Río Madre de Díos, Peru, upper Rio Madeira basin. The new species is distinguished from all congeners by a unique combination of characters, including its dorsal color pattern formed by a relatively slender, highly convoluted, beige to dark brown vermicular pattern, a single row of dorsal tail spines, and a relatively longer tail posterior to caudal stings. Potamotrygon tatianae sp. nov., occurs sympatrically with other species of Potamotrygon (P. falkneri, P. orbignyi and P. motoro). From the similar species P. falkneri, P. tatianae sp. nov., is further distinguished by the absence of circular, reniform, and oval spots, by its proportionally much longer tail, by having dorsal tail spines in one irregular row, and by features of the ventral lateral-line canal, dermal denticles and neurocranium. From P. orbignyi, the new species is distinct by lacking a reticulate pattern on dorsal disc and by the presence of two angular cartilages. From P. motoro, P. tatianae sp. nov., is further separated by the lack of ocelli formed by strong black concentric rings, by the more flattened aspect of its head and disc, and by having smaller and more numerous teeth. The discovery of a new species that so closely resembles a congeneric form in color pattern, a feature highly variable within the latter, highlights the importance of examining large series of individuals and of detailed morphological analyses in revealing the potentially highly cryptic nature of the diversity within the family.

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The occipital dysplasia has been characterized by a dorsal enlargement of the foramen magnum which can vary in size and shape. Clinical signs may be present or not in animals with occipital dysplasia. The purpose of this study was to radiographically analyze the morphology and morphometry of the foramen magnum of thirty healthy dogs. This study chose to use fifteen Yorkshire terrier dogs and fifteen Toy Poodle dogs in order to characterize the radiographic aspects of the foramen magnum and contribute to the diagnosis and critical analysis of the occipital dysplasia importance. According to the foramen magnum morphology and tracings, it was possible to classify the radiographic aspects into different shapes varing from oval and quadrangular. Out of 26 (86.7%) animals had a dorsal enlargement and 4 (13.3%) showed normal foramen magnum. Animals without any clinical signs that are radiographically classified as dysplastic dogs may simply represent an anatomic variation of the foramen magnum.

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The starch of maca (Lepidium meyenii Walpers) presented oval and irregular morphology, with granule size between 7.4 and 14.9 mu m in length and 5.8 and 9.3 mu m in diameter. The isolated starch showed the following features: purity of 87.8%, with 0.28% lipids, 0.2% fibre and 0.12% fixed mineral residue, and no protein detected; the ratio between the amylose and amylopectin contents were 20:80: the solubility at 90 degrees C was 61.4%, the swelling power was 119.0g water/g starch and the water absorption capacity was 45.9 g water/g starch; the gel turbidity rose 44% during the storing time; the gelatinization temperature was 47.7 degrees C and the transition enthalpy 6.22 J/g; the maximum viscosity reached 1260 UB at 46.4 degrees C, with breakdown, setback and consistence of 850, 440 and -410 UB, respectively. The low gelling temperature and the stability during gel refrigeration could be adequate for foods requiring moderate temperature process, but not for frozen food. (C) 2008 Elsevier Ltd. All rights reserved.

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Marcelo A. Scelzo, Marina Z. Fantucci, and Fernando L. Mantelatto (2010) Spermatophore and gonopore morphology of the southwestern-Atlantic hermit crab Pagurus exilis (Benedict, 1892) (Anomura, Paguridae). Zoological Studies 49(3): 421-433. The form and function of the spermatophore have been used as a complementary tool in studies of the reproductive biology and systematics of hermit crabs. In this context, we describe the spermatophore and gonopore morphology of Pagurus exilis. The spermatophores were extracted from the distal part of the vas deferens of specimens collected in Argentina and Brazil. The spermatophores were composed of 3 major regions: a main ampulla (with a sperm capsule inside and an accessory ampulla at the base), a stalk, and a pedestal. Each spermatophore had a distinct dorsolateral suture line around the ampulla, where the rupture occurs to release the sperm. The spermatophore total length was 1.5 times the main ampulla length. The main ampulla was oval and slightly flattened. A triangular accessory ampulla extended from the main ampulla base to the pedestal on 1 side, and contained no to several sperm. The stalk is short and flattened, and as wide as the main ampulla. One to 3 spermatophores were found attached to each pedestal, which was almost oblong in shape. The dimensions of the spermatophore and its component parts were directly influenced by the size of the hermit crab. Gonopores of males were covered by long pappose setae, while female gonopores bore a few short cuspidate setae. Specimens from Brazil and Argentina had the same spermatophore morphology, corroborating the previously observed absence of genetic differences between the both populations. The spermatophore morphology of this species has similarities with the broad general pattern of the Paguridae, being most similar to one of the (at least) 3 patterns of spermatophore morphology described for Pa gurus. http://zoolstud.sinica.edu.tw/Journals/49.3/421.pdf

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The longest open reading frame of PKHD1 (polycystic kidney and hepatic disease 1), the autosomal recessive polycystic kidney disease (ARPKD) gene, encodes a single-pass, integral membrane protein named polyductin or fibrocystin. A fusion protein comprising its intracellular C-terminus, FP2, was previously used to raise a polyclonal antiserum shown to detect polyductin in several human tissues, including liver. In the current study, we aimed to investigate by immunohistochemistry the detailed polyductin localization pattern in normal (ductal plate [DP], remodelling ductal plate [RDP], remodelled bile ducts) and abnormal development of the primitive intrahepatic biliary system, known as ductal plate malformation (DPM). This work also included the characterization of polyductin expression profile in various histological forms of neonatal and infantile cholestasis, and in cholangiocellular carcinoma (CCC) and hepatocellular carcinoma (HCC). We detected polyductin expression in the intrahepatic biliary system during the DP and the RDP stages as well as in DPM. No specific staining was found at the stage of remodelled bile ducts. Polyductin was also detected in liver biopsies with neonatal cholestasis, including mainly biliary atresia and neonatal hepatitis with ductular reaction as well as congenital hepatic fibrosis. In addition, polyductin was present in CCC, whereas it was absent in HCC. Polyductin was also co-localized in some DP cells together with oval stem cell markers. These results represent the first systematic study of polyductin expression in human pathologies associated with abnormal development of intrahepatic biliary tree, and support the following conclusions: (i) polyductin expression mirrors developmental properties of the primitive intrahepatic biliary system; (ii) polyductin is re-expressed in pathological conditions associated with DPM and (iii) polyductin might be a potential marker to distinguish CCC from HCC.

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Although cigarette smoking and alcohol consumption increase risk for head and neck cancers, there have been few attempts to model risks quantitatively and to formally evaluate cancer site-specific risks. The authors pooled data from 15 case-control studies and modeled the excess odds ratio (EOR) to assess risk by total exposure (pack-years and drink-years) and its modification by exposure rate (cigarettes/day and drinks/day). The smoking analysis included 1,761 laryngeal, 2,453 pharyngeal, and 1,990 oral cavity cancers, and the alcohol analysis included 2,551 laryngeal, 3,693 pharyngeal, and 3,116 oval cavity cancers, with over 8,000 controls. Above 15 cigarettes/day, the EOR/pack-year decreased with increasing cigarettes/day, suggesting that greater cigarettes/day for a shorter duration was less deleterious than fewer cigarettes/day for a longer duration. Estimates of EOR/pack-year were homogeneous across sites, while the effects of cigarettes/day varied, indicating that the greater laryngeal cancer risk derived from differential cigarettes/day effects and not pack-years. EOR/drink-year estimates increased through 10 drinks/day, suggesting that greater drinks/day for a shorter duration was more deleterious than fewer drinks/day for a longer duration. Above 10 drinks/day, data were limited. EOR/drink-year estimates varied by site, while drinks/day effects were homogeneous, indicating that the greater pharyngeal/oral cavity cancer risk with alcohol consumption derived from the differential effects of drink-years and not drinks/day.

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In this report, we describe a case of disseminated sporotrichosis that was diagnosed by fine-needle aspiration biopsy (FNAB). The cytologic smears exhibited a large number of macrophages, few polymorphonuclear neutrophils and numerous round or oval, sometimes elongated, isolated and scattered yeast-like structures localized extracellularly or inside macrophages. These structures were clearly visualized by Giemsa and Papanicolaou methods. Cultures from skin biopsy material revealed,fungal colonies which were subsequently identified as Sporothrix schenckii. The cytologic aspects, the correlation with histologic findings and the differential cytologic diagnosis were reviewed.

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Upper premolars restored with endodontic posts present a high incidence of vertical root fracture (VRF). Two hypotheses were tested: (1) the smaller mesiodistal diameter favors stress concentration in the root and (2) the lack of an effective bonding between root and post increases the risk of VRF. Using finite element analysis, maximum principal stress was analyzed in 3-dimensional intact upper second premolar models. From the intact models, new models were built including endodontic posts of different elastic modulus (E = 37 or E = 200 GPa) with circular or oval cross-section, either bonded or nonbonded to circular or oval cross-section root canals. The first hypothesis was partially confirmed because the conditions involving nonbonded, low-modulus posts showed lower tensile stress for oval canals compared to circular canals. Tensile stress peaks for the nonbonded models were approximately three times higher than for the bonded or intact models, therefore confirming the second hypothesis. (J Endod 2009;35:117-120)

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P>Objective To evaluate the influence of apical size on cleaning of the apical third of curved canals prepared with rotary instruments. Methodology Forty-four mesiobuccal canals of maxillary molars teeth were instrumented to different apical sizes (30, 0.02; 35, 0.02; 40, 0.02; 45, 0.02) using a crown-down technique. After canal preparation, the apical thirds of the roots were submitted to histological processing and examination. The specimens were analysed at 40x magnification and the images were submitted to morphometric analysis with an integration grid to evaluate the percentage of debris and uninstrumented root canal walls. The action of the instruments on the root canal walls was assessed based on the surface regularity, abrupt change on the continuity of root canal walls, and partial or total pre-dentine removal. The results were statistically compared using one-way anova with post hoc Tukey test. Pearson`s correlation was performed to identify potential correlations between values. Results The percentage of uninstrumented root canal dentine was higher when apical enlargement was performed with instruments 30, 0.02 taper (55.64 +/- 4.62%) and 35, 0.02 taper (49.03 +/- 5.70%) than with instruments 40, 0.02 taper (38.08 +/- 10.44%) and 45, 0.02 taper (32.65 +/- 8.51%) (P < 0.05). More debris were observed when apical enlargement was performed with instruments 30, 0.02 taper (34.62 +/- 9.49%) and 35, 0.02 taper (25.33 +/- 7.37%) (P < 0.05). There was a significant correlation between the amount of remaining debris and the perimeter of uninstrumented root canal dentine (r = 0.9130, P < 0.001). Conclusion No apical enlargement size allowed the root canal walls to be prepared completely. Apical third cleanliness could be predicted by instrument diameter.