214 research outputs found

    Streaming contents and RSS feed in a pedagogical environment

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    A group of university teachers have been developing several contents using streaming technology, since it promotes the support of pedagogical activity as a dynamic resource and due to the fact that is oriented to a model of shared learning contents. Now, a new challenge can be stated: the share and the reutilization of these learning contents. Apart from being an enhanced experience only concerning the sharing of knowledge, it promotes a desired partnership inter/intra-department. In this context the RSS technology introduces a new dimension in the access to streaming media contents. The RSS is a format to syndicate contents enabling users to be aware of new contents that are periodically published. The RSS technology, through the use of RSS Aggregators or RSS Readers, help the user to keep up to date all their favourite information sources that provide their contents as RSS feeds. In the scope of the streaming media contents the definition of RSS feeds enable the students to be up to date of new educational resources that are provided by the teacher. Therefore the students instead of checking the updates that are published in several educational information resources can locally see the new resources that are described and provided in the RSS feed. Some preliminaries results are presented and discussed

    Tenascina e fibronectina em adenoma pleomórfico de glândula salivar

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    OBJECTIVES: To analyze the expression and distribution pattern of extracellular matrix components in pleomorphic adenomas of the major and minor salivary glands and to compare the morphological findings of these tumors with the immunohistochemical expression, considering the different types of stroma predominating in each case. METHODS AND RESULTS: The expression of tenascin (TN) and fibronectin (FN) was analyzed in 23 cases of pleomorphic adenomas, 11 major and 12 minor salivary gland tumors, by the streptavidin-biotin method using anti-tenascin and anti-fibronectin antibodies. In addition, the immunohistochemical results were correlated with the morphological findings of the lesions. All cases analyzed were immunoreactive for the antibodies used. Fibronectin showed strong labeling in fibrous and chondroid stroma, while labeling was weak in hyaline and myxoid stroma. Tenascin expression was more intense in fibrous and chondroid stroma and moderate in hyaline and myxoid stroma. CONCLUSIONS: No difference in the expression of these proteins was observed between major and minor salivary gland tumors.OBJETIVO: Analisar a expressão e o padrão de distribuição de componentes da matriz extracelular em adenomas pleomórficos de glândula salivar maior e menor e comparar os achados morfológicos destes tumores com a expressão imuno-histoquímica considerando os diferentes tipos de estromas presentes em cada caso. MÉTODOS E RESULTADOS: A expressão da tenascina (TN) e fibronectina (FN) foi analisada em 23 casos de adenomas pleomórficos, sendo 11 tumores em glândula salivar maior e 12 em glândula salivar menor, utilizando-se o método da estreptoavidina-biotina para os anticorpos anti-tenascina e anti-fibronectina. Os resultados imuno-histoquimicos foram correlacionados com os achados morfológicos das lesões. Todos os casos foram imunorreativos para a fibronectina mostrando forte expressão nos estromas fibrosos e condróides, embora fraca marcação tenha sido evidenciada nos estromas hialinos e mixóides. A expressão da tenascina foi mais intensa nos estromas condróides e fibrosos, sendo moderada nos estromas hialino e mixóide. CONCLUSÕES: Não houve diferença na expressão destas proteínas entre os tumores de glândula salivar maior e menor

    Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

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    The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens. OBJECTIVES: The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated. MATERIAL AND METHODS: DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique. RESULTS: From the 27 cases, 9 (33.3%) were HPV-positive and 18 (66.0%) HPV-negative. HPV 18 was the most prevalent viral type (100% cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38). CONCLUSIONS: The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells

    The recurrence of odontogenic keratocysts in pediatric patients is associated with clinical findings of Gorlin-Goltz Syndrome

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    Odontogenic keratocyst (OKC) is an odontogenic developmental cyst that presents distinct clinical behavior. This lesion has been described as dental cysts with keratinization since the 1930s, however the term "OKC" was established in 1956. This study aims to determine the frequency and features of OKC in children aged 0 to 14 years in an oral pathology service in Brazil. A retrospective study was performed to review cases of OKC in children diagnosed between 1986 and 2017. Clinical data were evaluated from medical records (gender, race, age, anatomical location, treatment, radiographic findings and follow-up). Ninety-seven cases of OKC were diagnosed in a 31-year-period in all age groups and 10 were found in children (10.3%). Age ranged from 2 to 14 years (mean age=10.5±3.5), with 8 males and 2 females. The most frequent location was the anterior region of the mandible (n=4). Patients were predominantly asymptomatic. Moreover, in two children, clinical findings of Gorlin-Goltz Syndrome were observed. The most commonly used treatment was enucleation followed by curettage. In all cases of Gorlin-Goltz Syndrome were observed recurrences and occurrence of new keratocysts. Although uncommon in pediatric patients, OKC should be considered a differential diagnosis in cases of osteolytic lesions in gnathic bones. Thus, the periodic assessment of children by dentists and pediatricians is essential to get a correct diagnosis and early treatment to avoid greater mutilation of these patients

    Odontogenic tumors: analysis of 127 cases

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    De uma série de 5.289 casos de lesões orais e dos maxilares diagnosticadas no Laboratório de Patologia Oral da Faculdade de Odontologia da Universidade Federal do Rio Grande do Norte no período de 30 anos (1970-1999), foram analisados 127 casos de tumores odontogênicos confirmados histologicamente. A lesão mais freqüente foi o odontoma (50,40%) seguida pelo ameloblastoma (30,70%). A prevalência de tumores odontogênicos foi maior nas mulheres e o pico de incidência ocorreu na segunda e terceira décadas de vida. A localização anatômica mais comum foi a mandíbula e não foram encontrados casos de tumores malignos.One hundred and twenty-seven cases of histologically confirmed odontogenic tumors were retrieved from a total of 5,289 oral and maxillary lesions diagnosed at the Division of Oral Pathology, Federal University of Rio Grande do Norte, during a period of 30 years (l970-l999). The most common histological diagnosis was odontoma (50.40%), followed by ameloblastoma (30.70%). The prevalence of odontogenic tumors was greater in females and the peak incidence occurred in the second and third decades of life. The main anatomical location was the mandible, and no malignant tumors were found

    Clinicopathological analysis of odontogenic tumors over 22 years period : experience of a single center in northeastern Brazil

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    Odontogenic tumors (OTs) are uncommon neoplastic lesions of the maxilla and mandible, which present difficult diagnosis and therapeutics. This paper aims to determine the frequency and distribution of OTs, over a period of 22 years, at a public university in Northeastern Brazil. We reviewed all cases of OTs from oral pathology laboratory of Federal University of Rio Grande do Norte (UFRN), from 1996 to 2017. The tumors were classified according to the latest (2017) World Health Organization Classification of Tumors. Data on age, gender, anatomic site, symptomatology, radiographic findings and tumor size were analyzed. In the analyzed period, 247 cases of OTs were diagnosed. Epithelial tumors were more common with 127 cases (51.8%). The most common tumors were ameloblastoma (n = 112 / 45.4%), odontoma (n = 89 / 36.1%) and odontogenic myxoma (n = 17 / 6.9%). Malignant odontogenic tumors were extremely rare in the studied population with only 2 cases (0.8%) of diagnosed carcinomas. These tumors were diagnosed in a wide age range, from 5 to 81 years, being more common in the second and third decades of life. In general, the mandible was the most affected anatomic site (n = 162/66%) and the mandible:maxilla ratio was of 2:1. Ameloblastoma was the tumor with the highest number of symptomatic cases (n = 26) and with the highest mean size (cm) with 4.5cm. Odontogenic tumors were rare in the sample studied (2.2%), with ameloblastoma and odontoma being the most common tumors. Continuous studies that show the characteristics of these lesions are fundamental, especially after modifications in the international classification

    Immunohistochemical analysis of bone resorption regulators (RANKL and OPG), angiogenic index, and myofibroblasts in syndrome and non-syndrome odontogenic keratocysts

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    Objective The aim of this study was to immunohistochemically analyse bone resorption regulators (receptor activator of nuclear factor kappa B ligand [RANKL] and osteoprotegerin [OPG]), angiogenic index, and myofibroblasts in Gorlin syndrome-related odontogenic keratocysts (SOKCs) and non-syndrome odontogenic keratocysts (NSOKCs). Study design Twenty-two SOKCs, 22 primary NSOKCs, and eight recurrent NSOKCs were evaluated by immunohistochemistry using anti-RANKL and anti-OPG antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-CD34 antibody. Anti-α-smooth muscle actin (α-SMA) antibody was used for the identification of myofibroblasts. Results Analysis of the expression of RANKL and OPG in the epithelial lining and fibrous capsule did not reveal significant differences between groups (P > 0.05). In the epithelial lining, the RANKL/OPG ratio was RANKL 0.05). In the fibrous capsule, the ratio was RANKL = OPG in most primary (81.8%) and recurrent NSOKCs (75.0%) and in most SOKCs (45.5%) (P > 0.05). No significant differences in the angiogenic index or number of myofibroblasts were observed between primary NSOKCs, recurrent NSOKCs, and SOKCs (P > 0.05). Conclusions The present results suggest that differences in the biological behaviour of SOKCs and NSOKCs may not be related to the expression of RANKL and OPG, to the RANKL/OPG ratio, to the angiogenic index, or to the number of myofibroblasts in these lesions

    Immunohistochemical expression of vascular endothelial growth factor and matrix metalloproteinase-9 in radicular and residual radicular cysts

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    OBJECTIVE: This study assessed and compared the immunoexpression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in radicular cysts (RCs) and residual radicular cysts (RRCs), relating them to the angiogenic index and the intensity of the inflammatory infiltrate. MATERIAL AND METHODS: Twenty RCs and 10 RRCs were evaluated by immunohistochemistry using anti-VEGF and anti-MMP-9 antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-von Willebrand factor antibody. RESULTS: The expression of both VEGF and MMP-9 was higher in RCs than in RRCs. RCs and RRCs presented strong epithelial expression of VEGF, irrespective of the intensity of the inflammatory infiltrate. Lesions with strong expression of MMP-9 showed significantly higher number of immunopositive cells for VEGF (

    Expression of glucose transporters 1 and 3 in metastatic and non-metastatic lower lip squamous cell carcinoma

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    Este estudo objetivou avaliar a imunoexpressão dos transportadores de glicose 1 (GLUT-1) e 3 (GLUT-3) em carcinomas de células escamosas de lábio inferior (CCELI) metastáticos e não-metastáticos. Vinte CCELIs com metástase nodal regional e 20 CCELI sem metástase foram selecionados. Foram analisados a distribuição da imunomarcação e o percentual de imunorreatividade para GLUT-1 e GLUT-3 no centro tumoral e no front de invasão tumoral. A maioria dos tumores (70%) revelou marcação para GLUT-1 em áreas periféricas dos ninhos, lençóis e ilhas de células neoplásicas, ao passo que GLUT-3 revelou predomínio de marcação em áreas centrais (72.5%). Um alto percentual de células positivas para GLUT-1 foi observado no front de invasão e no centro tumoral das lesões metastáticas e não-metastáticas (p>0,05). O percentual de células positivas para GLUT-1 foi superior ao percentual de células positivas para GLUT-3, tanto no front de invasão (p0,05). Em conclusão, os resultados do presente estudo sugerem um importante papel para GLUT-1 na absorção de glicose nos CCELIs, embora esta proteína não pareça estar envolvida na progressão destes tumores. Por outro lado, a expressão de GLUT-3 pode representar um mecanismo secundário para a absorção de glicose nos CCELIs

    Botryoid odontogenic cyst: a clinicopathologic study of 10 cases

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    Botryoid odontogenic cyst is a rare multilocular variant of lateral periodontal cysts. In this study, a series of 10 cases of botryoid odontogenic cysts retrieved from the archives of the Postgraduation Program in Oral Pathology, Federal University of Rio Grande do Norte (Brazil), were reviewed for epidemiologic data, clinical presentation, radiographic and histopathologic characteristics, treatment, and recurrence
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