Expression of the cell cycle regulation proteins p53 and p21WAF1 in different types of non-dysplastic leukoplakias

OBJECTIVES: The aim of this study was to analyze the immunolabeling of two cell cycle protein regulators, p53 and p21WAF1, in non-dysplastic leukoplakias with different epithelial alterations: acanthosis, hyperkeratosis and acanthosis combined with hyperkeratosis, and compare them with dysplastic leukoplakias. MATERIAL AND METHODS: This was a prospective cohort study involving 36 patients with oral homogeneous leukoplakias. excisional biopsies were performed and the patients remain under clinical follow-up. The leukoplakias were divided into four groups: 6 acanthosis, 9 hyperkeratosis, 10 acanthosis combined with hyperkeratosis, and 11 epithelial dysplasias. Paraffin-embebeded sections were immunostained for p53 and p21WAF1. Five hundred cells from the basal layer and 500 from the parabasal layer were counted to determine the percentage of positive cells. A qualitative analysis was also carried out to determine the presence or absence of immunohistochemical staining in the intermediate and superficial layers. Groups were compared with ANOVA (

The use of tissue engineering in dentistry

Avanços na área de biologia molecular e celular têm contribuído para o desenvolvimento de técnicas de reparo ou, até mesmo, de regeneração de órgãos e tecidos injuriados por doenças, traumas e deformidades congênitas. A engenharia tecidual é um campo interdisciplinar que aplica princípios da engenharia, biologia e ciências clínicas para o desenvolvimento de substitutos biológicos que possam manter, restaurar, ou melhorar a função de órgãos e tecidos. Essa nova ciência está embasada em três pontos: células, matrizes biocompatíveis e moléculas bioativas responsáveis pelos sinais morfogênicos. As células usualmente empregadas são as células-tronco. Buscamos neste artigo atualizar os cirurgiões dentistas no conceito de engenharia tecidual e em que contesto está sendo pesquisada na Odontologia, mais especificamente nas áreas que envolvem periodonto e polpa.Advances in molecular and cellular biology have contributed to the development of techniques to repair, or even regenerate, organs and tissues that have been injured by diseases, traumas and congenital deformities. Tissue engineering is an interdisciplinary field that applies the principles of engineering, biology and the clinical sciences to the development of biological substitutes that are able to maintain, restore or improve the function of organs and tissues. This new science is based on three components: cells, biocompatible matrices and bioactive molecules which are responsible for morphogenic signals. The cells most often used are stem cells. This article is aimed to bring dental surgeons up to date on tissue engineering concepts and the context in which tissue engineering is being studied within Dentistry; specifically, areas related to periodontium and pulp

The effect of different histological techniques in studies involving measurements

O trabalho analisa as alterações dimensionais decorrentes das diferentes técnicas de processamento histológico em estruturas complexas como a mandíbula, que abriga diferentes tecidos mineralizados e diferentes tecidos moles. A partir dos resultados obtidos conclui-se que, em estudos que envolvem mensurações em cortes histológicos é necessário considerar que a técnica de inclusão em parafina produz contração no material, o mesmo ocorrendo, porém em menor escala com material congelado, quando comparados com material não descalcificado.This research makes an analysis of the dimensional changes produced by different technical histologic procedure in a complex structure like mandible that has hard tissues and soft one. From the results it was concluded that in studies where measurements are supposed to be performed it is necessary to take into account that paraffin embedding produces contraction as does frezing technic although in a smaller amount, when these are compared to material that has not been decalcified

Immunohistochemical analysis of the patterns of p53 and PCNA expression in odontogenic cystic lesions

Objective: the role of p53 expression in odontogenic lesions has not been fully determined, but has been associated with cell proliferation. The purpose of this study was to analyze p53 and proliferating cell nuclear antigen (PCNA) expression in 4 different odontogenic lesions. Design: expression of p53 and PCNA was analyzed in radicular and dentigerous cysts, odontogenic keratocysts, and calcifying odontogenic cysts (Gorlin cysts) using monoclonal antibodies for detection of p53 and PCNA. Results: PCNA expression was significantly greater in the basal layer of radicular cysts and in the suprabasal layer of odontogenic keratocysts; the percentage of p53 positive cells was significantly greater in the suprabasal layer of odontogenic keratocysts. Conclusions: The patterns of p53 and PCNA expression in dentigerous and radicular cysts were similar although the two lesions are of different origin. In odontogenic keratocysts and Gorlin cysts, results indicate a different pattern of tumor growth

Quantifìcação de AgNORs e expressão do PCNA em ceratocisto odontogênico

Para realização deste estudo foram selecionados quinze casos de Ceratocisto Odontogênico e submetidos à técnica histoquímica de AgNOR e à técnica imuno-histoquímica do PCNA. Observou-se que o Ceratocisto Odontogênico possui uma média de 1,84 AgNORs por núcleo e que 74,98% das células são positivas ao PCNA. Uma característica constante foi que tanto para o AgNOR quanto para o PCNA a camada suprabasal apresentou médias estatisticamente superiores à camada basal. Conclui-se, portanto, que o Ceratocisto Odontogênico é uma lesão benigna com proliferação do epitélio, principalmente na camada suprabasal

Evaluation of cell proliferation rate in non-dysplastic leukoplakias

Objective: Analyze whether the most frequent cases of non-dysplastic leukoplakias, hyperkeratosis (H), acanthosis (A), and hyperkeratosis with acanthosis (HA) have similar cell proliferation rates and to compare them with epithelial dysplastic (ED) leukoplakias and normal oral epithelium (NOE).Study design: The sample comprised 10 cases of normal oral epithelium, 10 cases of hyperkeratosis, 10 cases of acanthosis, 10 cases of hyperkeratosis with acanthosis and 10 cases of epithelial dysplasia. The mean number of AgNORs per nucleus (mAgNOR) and the mean percentage of cells with 1, 2, 3 and 4 or more AgNORs per nucleus (pAgNOR) were recorded. Results: The results of mAgNOR showed differences between disorders in the evaluation of the basal layer, of the parabasal layer, and in the overall evaluation. mAgNOR and pAgNOR=2 increased progressively from normal oral epithelium to hyperkeratosis with acanthosis, hyperkeratosis, acanthosis and epithelial dysplasia (p<0.05). Cell proliferation rate was different between different subtypes of non-dysplastic leukoplakias and this group presented a higher proliferative behavior when compared to normal oral epithelium. Conclusion: It may be suggested that non-dysplastic leukoplakias had different characteristics regarding cell proliferation rates and sometimes showed a proliferative behavior similar to that found in epithelial dysplasia. More studies should be conduced to increase knowledge about the biological profile of non-dysplastic leukoplakias, especially as it pertains to acanthosis

Nodular fasciitis: Case report with immunohistochemical analisys

A fascite nodular é uma lesão benigna de células fusiformes que freqüentemente é confundida com lesões malignas. O relato do caso clínico coincide com os aspectos clínicos, microscópicos e imunohistoquímicos. Os autores salientam que a definição do diagnóstico desta lesão deve ser realizado a partir de suas características microscópicas que orientam a definição do painel imunohistoquímico.Nodular fasciitis is a benign lesion composed of fusiform cells frequently misdiagnosed as malignant lesion. This report of case have similar clinical, microscopic and immunohistochemical with the literature reviewed. The immunohistochemical pannel should be decided upon the microscopic appearence of the lesion