Abstract: The objective of this study was to analyze the quality of videos on oral lichen planus (OLP) available in YouTube™. A cross-sectional analytical study was conducted by searching the video sharing platform YouTube™. Videos aimed at clarifying the etiological and clinical characteristics, diagnostic criteria, treatment, and prognosis of OLP were included. A total of 481 videos were retrieved and 37 were included in the study according to the selection criteria established. Most of the videos evaluated (86.5%; n = 32) were produced by independent users. The average reliability was 1.8 and quality assessment classified only three videos (8.1%) as having good/excellent quality. A significant correlation was observed between the length of the video analyzed and its quality and reliability (p < 0.05), as well as between the reliability and usefulness of the video (p = 0.03). YouTube™ has become a leading source of information for the general population. However, a significant number of these videos have a low quality. Students, professionals, and healthcare providers must be more actively involved in providing clear, accurate, and reliable evidence-based information in an accessible language in order to enable significant improvement in patient care delivery.

SUMMARY: Mesenchymal cells (MCs) exhibit great regenerative potential due to their intrinsic properties and ability to restore tissue function, either directly through transdifferentiation or indirectly through paracrine effects. This study aimed to evaluate morphometric and phenotypic changes in MCs grown with facial nerve-conditioned medium in the presence or absence of fibroblast growth factor 2 (FGF-2). For quantitative phenotypic analysis, the expression of GFAP, OX-42, MAP-2, β-tubulin III, NeuN, and NF-200 was analyzed by immunocytochemistry. Cells cultured with facial nerve-conditioned medium in the presence of FGF-2 expressed GFAP, OX-42, MAP-2, β-tubulin III, NeuN, and NF-200. On average, the area and perimeter of GFAP-positive cells were higher in the group cultured with facial nerve-conditioned medium compared to the group cultured with conditioned medium and FGF-2 (p=0.0001). This study demonstrated the plasticity of MCs for neuronal and glial lineages and opens up new research perspectives in cell therapy and trans.differentiation.

RESUMEN: Las células mesenquimales (CM) exhiben un gran potencial regenerativo debido a sus propiedades intrínsecas y la capacidad de restaurar la función del tejido, ya sea directamente, a través de la transdiferenciación, o indirectamente, a través de efectos parácrinos. Este estudio tuvo como objetivo evaluar los cambios morfométricos y fenotípicos en CM cultivadas con medio condicionado por nervio facial en presencia o ausencia de factor de crecimiento de fibroblastos 2 (FGF-2). Para el análisis fenotípico cuantitativo, se analizó la expresión de GFAP, OX-42, MAP-2, β-tubulina III, NeuN y NF-200 mediante inmunocitoquímica. Las células cultivadas con medio condicionado por el nervio facial en presencia de FGF-2 expresaban GFAP, OX-42, MAP-2, β-tubulina III, NeuN y NF-200. En promedio, el área y el perímetro de las células positivas para GFAP fueron mayores en el grupo cultivado con medio condicionado por el nervio facial en comparación con el grupo cultivado con medio acondicionado y FGF-2 (p = 0,0001). Este estudio demostró la plasticidad de CM para linajes neuronales y gliales y abre nuevas perspectivas de investigación en terapia celular y transdiferenciación.

RESUMO Objetivo Avaliar o efeito do laser de baixa intensidade na proliferação e na viabilidade de células-tronco derivadas de tecido adiposo murinas previamente submetidas à criopreservação. Métodos Células-tronco derivadas de tecido adiposo foram isoladas da região inguinal de três camundongos, submetidas à criopreservação em soro fetal bovino com 10% de dimetilsulfóxido por 30 dias e, depois, descongeladas e mantidas em condições normais de cultivo. As células cultivadas foram irradiadas ou não (controle) com um laser de diodo InGaAIP nos intervalos de zero e 48 horas, utilizando duas densidades de energia diferentes (0,5 e 1,0J/cm2). A proliferação celular foi avaliada pelo método de exclusão de azul de tripan e ensaio MTT, nos intervalos de zero, 24, 48 e 72 horas após a primeira aplicação do laser. A viabilidade celular e a apoptose das células previamente criopreservadas submetidas à laserterapia foram avaliadas por citometria de fluxo. Resultados Os Grupos Irradiados (0,5 e 1,0J/cm2) apresentaram aumento da proliferação celular (p<0,05) quando comparados ao Grupos Controle, porém não foi observada diferença significativa entre as duas densidades de energia. A citometria de fluxo revelou percentagem de células viáveis superior a 99% em todos os grupos. Conclusão O laser de baixa intensidade tem efeitos estimuladores sobre a proliferação de células-tronco derivadas de tecido adiposo previamente submetidas à criopreservação.

ABSTRACT Objective To evaluate the effect of low-level laser irradiation on proliferation and viability of murine adipose-derived stem cells previously submitted to cryopreservation. Methods Adipose-derived stem cells were isolated from inguinal fat pads of three mice, submitted to cryopreservation in fetal bovine serum with 10% dimethylsulfoxide for 30 days and then thawed and maintained in normal culture conditions. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at zero and 48 hours, using two different energy densities (0.5 and 1.0J/cm2). Cell proliferation was evaluated by trypan blue exclusion method and MTT assay at intervals of zero, 24, 48, and 72 hours after the first laser application. Cell viability and apoptosis of previously cryopreserved cells submitted to laser therapy were evaluated by flow cytometry. Results The Irradiated Groups (0.5 and 1.0J/cm2) showed an increased cell proliferation (p<0.05) when compared to the Control Group, however no significant difference between the two energy densities was observed. Flow cytometry revealed a percentage of viable cells higher than 99% in all groups. Conclusion Low-level laser irradiation has stimulatory effects on the proliferation of adipose-derived stem cells previously submitted to cryopreservation.

Bone remodeling is a process regulated by the interaction between cells and various molecules such as parathyroid hormone (PTH). The aim of the study was to evaluate the effect of different doses of PTH on osteoclast activity in a culture model of bone organs. Six-day-old male C57BL/6 mice (n=14) were euthanized and the calvariae were dissected and sectioned in the middle, keeping the periosteal and endosteal. The bone fragments were divided into three groups: Group I (control - without adding PTH), Group II (addition of 3 nM PTH) and Group III (30 nM PTH), all cultured in aMEM for up to 72 h osteoclast activity was evaluated by biochemical quantification of calcium released in the culture medium at intervals of 24, 48, and 72 h and by histomorphometric analysis of bone resorption lacunae at 72 h our results show that group II exhibited significantly higher values of calcium levels in the medium compared to group I (p<0.05) in all intervals, also being higher for group III at 24 hours (p<0.05). Group II promoted a greater demineralization area (22068 ± 2193 mm2) than those found in group I (2084 ± 38 mm2) and group III (8952 ± 246 mm2), with statistically significant difference (p<0.001) among all groups. We concluded that in culture model of bone organs PTH promotes higher bone resorption when administered in lower doses.

La remodelación ósea es un proceso regulado por la interacción entre las células y varias moléculas como la hormona paratiroidea (PTH). El objetivo de este estudio fue evaluar el efecto de diferentes dosis de PTH sobre la actividad de los osteoclastos en un modelo de cultivo de órganos óseos. Se sacrificaron ratones C57BL/6 machos, de 6 días de edad (n = 14), y se disecaron y seccionaron las calvarias, manteniendo el periostio y endostio. Los fragmentos óseos se dividieron en tres grupos: Grupo I (control - sin adición de PTH), Grupo II (adición de 3 mM de PTH) y Grupo III (30 nM de PTH), todos cultivados en aMEM hasta 72 horas. La actividad de los osteoclastos se evaluó mediante la cuantificación bioquímica de calcio liberado en medio de cultivo, a intervalos de 24, 48 y 72 horas, y por análisis histomorfométrico de las lagunas de resorción ósea a las 72 horas. Nuestros resultados muestran que el grupo II exhibió valores significativamente más altos de calcio en el medio, comparado con el grupo I (p <0.05) en todos los intervalos, siendo también más alto para el grupo III a las 24 horas (p <0.05). El grupo II promovió una mayor área de desmineralización (22068 ± 2193 mm2) que los encontrados en el grupo I (2084 ± 38 mm2) y en el grupo III (8952 ± 246 mm2), con diferencia estadísticamente significativa (p <0,001) entre todos los grupos. Concluimos que en el modelo de cultivo de órganos óseos la PTH promueve una mayor resorción ósea cuando se administra en dosis más bajas.

Giant cell fibroma is a benign oral fibrous tumor and it is typically an asymptomatic sessile or pedunculated mass that is usually less than 1 cm in diameter. The lesion consists of uninflamed fibrous tissue in which there are numerous large uninucleated or multinucleated spindle- and stellate-shaped cells with prominent basophilic cytoplasm. The purpose of this paper is to report a case of a gingival giant cell fibroma of abnormal size. A 31-year-old white woman was referred to the dental service for evaluation of a growth on the mandibular gingival. The intraoral examination revealed a 3.0 × 1.5 cm exophytic gingival mass located in the lingual gingiva of the right mandibular permanent first and second molars. The differential diagnosis included peripheral ossifying fibroma, peripheral giant cell granuloma, and giant cell fibroma. Complete surgical excision of the lesion was performed and the diagnosis of giant cell fibroma was made. No complications or recurrence of the lesion have been noted after 4 years of follow-up. Although giant cell fibromas are benign lesions in which simple surgical excision is curative, it is very important that dental and medical professionals recognize it in light of the frequency of occurrence and the need for a precise diagnosis.

El fibroma de células gigantes es un tumor fibroso benigno de la mucosa bucal que típicamente se presenta como una masa asintomática sésil o pediculada generalmente menos de 1 cm de diámetro. La lesión consiste en tejido fibroso no inflamado en el que se encuentran numerosas células fusiformes y estrelladas de gran tamaño, mononucleares o multinucleadas con prominente citoplasma basófilo. El propósito de este trabajo es describir el caso de un fibroma gingival de células gigantes de tamaño inusual. Una mujer blanca de 31 años de edad se presentó al servicio dental para la evaluación de un crecimiento en la encía mandibular. El examen clínico intrabucal reveló una masa gingival exofítica de 3,0 cm x 1,5 cm situado en la encía lingual en el área de los primeros y segundos molares permanentes mandibulares del lado derecho. El diagnóstico diferencial incluyó fibroma osificante periférico, granuloma periférico de células gigantes y fibroma de células gigantes. Se realizó la escisión quirúrgica completa de la lesión y el diagnóstico definitivo fue de fibroma de células gigantes. No se han observado complicaciones o recurrencia de la lesión después de 4 años de seguimiento. Aunque los fibromas de células gigantes son lesiones benignas en las que la escisión quirúrgica simple es curativa, es muy importante que los profesionales dentales y médicos reconozcan la necesidad de un diagnóstico preciso en vista de la frecuencia de aparición.

Objetivo : Avaliar o efeito da terapia com laser de baixa intensidade sobre a proliferação e as possíveis alterações morfológicas nucleares em células-tronco mesenquimais de camundongos. Métodos : Células-tronco mesenquimais derivadas da medula óssea e do tecido adiposo foram submetidas a duas aplicações (T0 e T48 horas) de laser de baixa intensidade (660nm; doses de 0,5 e 1,0J/cm2). O ensaio de azul de tripan foi utilizado para a avaliação da viabilidade celular, e curvas de crescimento foram usadas para avaliar a proliferação das células em zero, 24, 48, e 72 horas. Alterações nucleares foram avaliadas por coloração com DAPI (4-6-diamidino-2-fenilindolo) em 72 horas. Resultados : As células-tronco mesenquimais derivadas da medula óssea responderam a terapia com laser de forma dose-dependente. Um maior crescimento celular foi observado quando as células foram irradiadas com dose de 1,0J/cm2, especialmente depois de 24 horas (p<0,01). As células-tronco mesenquimais derivadas do tecido adiposo responderam melhor à dose de 1,0J/cm2, com maior proliferação após 48 (p<0,05) e 72 horas (p<0,01). Nem alterações nucleares nem a mudança significativa na viabilidade celular foi detectada nos grupos estudados. Conclusão : Laser de baixa intensidade estimulou a proliferação de células-tronco mesenquimais sem causar alterações nucleares. A bioestimulação de células-tronco mesenquimais por laserterapia pode ser uma ferramenta importante para a terapia regenerativa e a engenharia tecidual.

Objective : To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Methods : Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm2). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4’-6-diamidino-2-phenylindole) at 72 hours. Results : Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm2, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm2, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Conclusion : Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering.

Angioleiomiomas são tumores mesenquimais benignos derivados de músculo liso que raramente ocorrem na cavidade oral. Relatamos um caso de angioleiomioma na gengiva maxilar. A lesão era indolor, com superfície lobulada, consistência fibrosa e firme à palpação. O exame histológico mostrou massa tumoral encapsulada, composta por grandes canais vasculares de diferentes calibres, circundados por paredes espessas de células fusiformes dispostas de forma irregular, as quais se apresentavam imunopositivas para actina de músculo liso. A distinção entre angioleiomioma e outros tumores de células fusiformes algumas vezes é difícil e, por essa razão, enfatizamos seu diagnóstico diferencial histológico.

Angioleiomyomas are benign mesenchymal tumors derived from smooth muscle, which rarely occur in the oral cavity. We report a case of an angioleiomyoma occurring in the maxillary gingiva. The lesion was painless, with a lobulated surface, fibrous in consistency, and firm upon palpation. Microscopic examination showed an encapsulated tumor mass composed of large vascular channels of varying calibers, surrounded by thick walls of irregularly arranged, spindle-shaped cells, which were immunopositive for smooth-muscle actin. It is sometimes difficult to differentiate an angioleiomyoma from other spindle-cell tumors, thus we emphasize its histological differential diagnosis.

AIM: To evaluate the proliferative capacity of mesenchymal cells derived from human periodontal ligament on polished and plasma-treated titanium surfaces. METHODS: Eighteen titanium disks were polished and half of them (n=9) were submitted to plasma nitriding using the cathodic cage technique. Mesenchymal cells were isolated from periodontal ligament of impacted third molars (n=2) and cultured on titanium disks (polished and nitrided) and on a plastic surface as a positive control of cell proliferation. Cell proliferation was analyzed and growth curves were constructed for the different groups by determining the number of cells adhered to the different surfaces at 24, 48 and 72 h after plating. RESULTS: Higher cell number was observed for the nitrided surface at 24 and 48 h. However, no statistically significant difference in cell proliferation was observed between the two different surface treatments (p>0.05). CONCLUSIONS: We concluded that plasma nitriding produced surfaces that permitted the proliferation of human periodontal ligament mesenchymal cells. Associated to other physical and chemical properties, it is possible to assume the feasibility of plasma nitriding method and its positive effect on the early cellular events of osseointegration.

INTRODUÇÃO: A técnica de criopreservação tem como característica cessar reversivelmente todas as funções biológicas dos tecidos vivos em baixas temperaturas e tem sido aplicada a diversas células humanas, visando à sua utilização posterior. OBJETIVO: Avaliar a proliferação de células mesenquimais do ligamento periodontal humano após a criopreservação por dois diferentes protocolos. MÉTODO: As células do ligamento periodontal foram obtidas a partir de dois dentes (terceiros molares) hígidos, com indicação de remoção cirúrgica. Após o processamento, as células foram cultivadas em placas de Petri e mantidas a 37 °C em 5% de CO2, até atingirem 70-90% de confluência, com troca de meio a cada três dias. Na primeira passagem, as células foram divididas em dois grupos e criopreservadas: Grupo -80 °C - criopreservação em ultrafreezer por 45 dias; Grupo -196 °C - criopreservação em nitrogênio líquido por 45 dias. Decorrido esse tempo, as células dos dois grupos foram descongeladas e plaqueadas para o experimento. A curva de crescimento dos grupos estudados foi traçada a partir de contagem em Câmara de Neubauer e pelo método de ensaio do MTT, nos intervalos de 24, 48 e 72 horas. Os resultados foram analisados por meio do teste de Mann‑Whitney, com nível de significância de 5%. RESULTADO: Verificou-se um crescimento ascendente nos dois protocolos utilizados, porém uma maior taxa proliferativa foi verificada no grupo criopreservado em nitrogênio líquido (p < 0,05). CONCLUSÃO: Ambos os protocolos de criopreservação estudados foram eficazes, porém a criopreservação em nitrogênio líquido (-196 °C) manteve uma maior taxa de proliferação celular em todos os intervalos de tempo.

INTRODUCTION: Cryopreservation aims to stop reversibly the biological functions of living tissues at low temperatures, and is an important resource for the storage of human cells for later use. AIM: To assess the proliferation of mesenchymal cells from human periodontal ligament cryopreserved by two different protocols. METHOD: Periodontal ligament cells were obtained from third molars with an indication for surgical removal. After processing, cells were grown and maintained at 37 °C in 5% CO2 until they reached 70-90% confluency, with medium changing every three days. In the first passage cells were divided into two groups, according to the protocol used: Group -80 °C - cryopreserved in ultrafreezer for 45 days, Group -196 °C - cryopreserved in liquid nitrogen for 45 days. After this time, cells from both groups were thawed and plated for the experiment. The growth curve of the groups was drawn from counting cells in a Neubauer chamber and by the MTT assay method, in the intervals of 24, 48 and 72 hours. The data were analyzed using the Mann-Whitney test with a significance level of 5%. RESULT: There was an upward cell growth in both protocols used, but a higher proliferative rate was observed in group cryopreserved in liquid nitrogen (p < 0.05). CONCLUSION: Cryopreservation has proven to be an effective technique for the storage and of mesenchymal cells from the periodontal ligament, especially when stored at a temperature of -196 °C.

The objective of this study was to evaluate the effectiveness of virtual learning as an approach to teaching human embryology. For this purpose, clinical cases comprising the six major topics of human embryology were organized into a blog in order to complement the content discussed in the classroom. Scientific articles were made available to reinforce theoretical contents and ethical-humanistic issues were addressed in discussion forums. The mean grades of the students at the end of the semester were compared with those of the previous semester when the method had not been applied. Student perceptions of blog effectiveness were evaluated using an electronic questionnaire. A substantial increase in mean grades was observed compared to the previous class. Analysis of the questionnaires showed that the students considered the blog to be a practical and useful learning tool. In conclusion, the use of clinical cases in a virtual learning environment is an effective tool to teach human embryology.

El objetivo del trabajo fue evaluar la eficacia de un método de enseñanza de la Embriología en ambiente virtual. Para complementar el contenido discutido en clases, fueron organizados en un blog, casos clínicos abordando seis ejes temáticos de Embriología Humana. Artículos científicos estuvieron disponibles para consolidación de los contenidos teóricos y el eje ético-humanístico fue abordado en foros de discusión. Al final del semestre la media de las notas de los alumnos fue comparada con la media de un semestre anterior donde la metodología no fue utilizada. La percepción de los alumnos con relación a la eficacia del uso del blog en el aprendizaje fue evaluada a través de un cuestionario electrónico. Se observó aumento considerable de la media de las notas al ser comparadas con las notas del período lectivo anterior. El análisis de los cuestionarios reveló que los alumnos consideraron el blog como un instrumento práctico y útil de aprendizaje. Se concluye que esta metodología representó una herramienta eficiente em la enseñanza de los contenidos de Embriología Humana.

INTRODUÇÃO: O tecido adiposo obtido por lipoaspiração pode ser uma fonte acessível de células-tronco, para posterior aplicação clínica na regeneração tecidual. O processo de criopreservação mantém essas células vivas por longos períodos, sem prejuízo a suas funções. O objetivo deste estudo foi avaliar a influência de um protocolo de criopreservação na proliferação das células-tronco derivadas do tecido adiposo. MÉTODO: Fragmentos de tecido adiposo de camundongos foram submetidos a digestão enzimática e as células foram cultivadas em meio α-MEM (do inglês Minimum Essential Medium), suplementado com 10% de soro fetal bovino (SFB), e mantidas a 37ºC em 5% de dióxido de carbono. No primeiro subcultivo, uma alíquota de 1x10(6) células foi criopreservada em SFB com 10% de dimetilsulfóxido por 30 dias, e outro grupo permaneceu em cultura. No terceiro subcultivo, as células dos dois grupos (não-criopreservadas e criopreservadas) foram plaqueadas e a viabilidade celular e as curvas de crescimento foram estabelecidas a partir de contagem em hemocitômetro e pelo ensaio de MTT, nos intervalos de 24 horas, 48 horas e 72 horas. A avaliação da morfologia nuclear foi realizada pela marcação por DAPI. Os dados foram analisados estatisticamente, com nível de significância de 5%. RESULTADOS: Observou-se padrão de crescimento celular ascendente em ambos os grupos, sem diferença significante ao longo do experimento (P > 0,05). Não houve alteração considerável da viabilidade celular e danos nucleares também não foram observados nos grupos estudados. CONCLUSÕES: O protocolo de criopreservação avaliado mostrou-se eficaz para manter a integridade das células-tronco de tecido adiposo, permitindo seu armazenamento para uso posterior.

BACKGROUND: Adipose tissue obtained by liposuction may be an accessible source of stem cells for future clinical application in tissue regeneration. Cryopreservation maintains stem cells in a live state for long periods of time, without impairing their function. The aim of this study was to assess the effect of a cryopreservation protocol on the proliferation of adipose-derived stem cells. METHODS: Fragments of mouse adipose tissue were subjected to enzymatic digestion in order to isolate cells that were then cultured in minimum essential medium (α-MEM) supplemented with 10% fetal bovine serum (FBS). Cells were maintained at 37°C in 5% carbon dioxide (CO2). At the first passage, an aliquot of 1 × 10(6) cells was cryopreserved in FBS with 10% dimethylsulfoxide (DMSO) for 30 days, whereas the remaining cells were seeded and maintained in culture. When these cells reached the third passage, the 2 groups of cells (cryopreserved and non-cryopreserved) were seeded for experiments. Cell viability and proliferation curves were established at intervals of 24, 48, and 72 hours by counting cells with a hemocytometer and MTT assay. Nuclear morphology was assessed by DAPI staining. The data were statistically analyzed, with a significance level of 5%. RESULTS: Increasing cellular proliferation was observed in both groups, with no significant difference throughout the experiment (P > 0.05). There was no significant change in cell viability and signs of nuclear damage were not detected in both the groups studied. CONCLUSIONS: The cryopreservation protocol analyzed was effective for maintaining the integrity of adipose-derived stem cells, allowing their storage for later use.

INTRODUÇÃO: A remodelação óssea é regulada por várias citocinas e hormônios, como a vitamina D3. Essa vitamina, em particular, regula positiva e negativamente a expressão do ligante do receptor ativador do fator nuclear kappa-B (RANKL) e da osteoprotegerina (OPG), respectivamente, e é usada como um indutor da formação de osteoclastos in vitro. OBJETIVO: Estudar o efeito da vitamina D (VitD) sobre a atividade osteoclástica em cultura de calvárias. MATERIAL E MÉTODO: Fragmentos de calvária de camundongos foram cultivados com meio básico (controle) ou com meio contendo VitD (10 nM: baixa dose; 100 nM: alta dose). Após os intervalos de 24, 48 e 72 horas, o meio de cultura foi coletado para dosagem de cálcio e os fragmentos foram fixados para análise em microscopia confocal. RESULTADOS: Observou-se que a adição de VitD nas duas dosagens promoveu aumento nos níveis de cálcio no meio, porém só foram encontradas diferenças estatisticamente significativas entre alta e baixa dose no intervalo de 24 horas. Na microscopia, foram observadas áreas de desmineralização mais amplas nos fragmentos de calvária cultivados com altas doses de VitD. CONCLUSÃO: A VitD promove aumento da atividade osteoclástica in vitro, de modo concentração-efeito.

INTRODUCTION: Bone remodeling is controlled by various cytokines and hormones, such as vitamin D3, which regulates receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) expression levels positively and negatively. It is also used as an inducer of osteoclast formation in vitro. OBJECTIVE: To evaluate the effect of vitamin D (VitD) on osteoclastic activity in cultured calvariae. MATERIAL AND METHOD: Fragments of mice calvaria were cultured in basic medium (control) or VitD-containing medium (10 nM: low dose; 100 nM: high dose). After intervals of 24, 48 and 72 hours, the culture medium was collected for calcium measurement and the fragments were fixed for confocal microscopy. RESULTS: It was observed that the addition of vitamin D in both concentrations promoted an increase of calcium levels in the medium. Nonetheless, statistically significant differences between high and low doses were detected only in the 24-hour interval. In the microscopic analysis, areas of demineralization were more extensive among calvariae cultured with high doses of VitD. CONCLUSION: VitD increases osteoclastic activity in vitro in a dose-dependent effect.

Nesse estudo, a expressão do antígeno nuclear de proliferação celular (PCNA) e da proteína p53, foi analisada em 16 casos de ameloblastoma e 8 casos de tumor odontogênico adenomatóide (TOA). Os casos de ameloblastoma eram do tipo sólido e, do ponto de vista morfológico, apresentavam-se nos diferentes subtipos histológicos. Em alguns casos, contudo, havia mais de um subtipo histológico na mesma lesão. As lesões foram então categorizadas em função da predominância dos achados histológicos, tendo sido identificados 7 casos de ameloblastoma com padrão folicular, 4 plexiformes, 3 foliculares + acantomatosos e 2 de células basais.Todas as lesões exibiram positividade para o PCNA e para a proteína p53, embora a expressão imunoistoquímica para o PCNA tenha sido mais forte nos casos de ameloblastoma folicular, enquanto a expressão da proteína p53 tenha se apresentou mais forte em ameloblastomas do subtipo plexiforme. A análise estatística (ANOVA e Teste de Tukey) não revelou diferença signficante (p>0.05) entre os tipos histológicos do ameloblastoma. Estes achados sugerem que os padrões histológicos do ameloblastoma não apresentaram correlação direta com o comportamento clinico e, conseqüentemente, com o prognóstico destas lesões. Os resultados também indicam que o ameloblastoma tem maior potencial proliferativo do que o TOA, o que contribui para explicar sua característica mais agressiva e invasiva.

In this study, proliferating cell nuclear antigen (PCNA) and p53 protein expressions were analyzed in 16 cases of ameloblastoma and 8 cases of adenomatoid odontogenic tumor (AOT). The cases of ameloblastoma consisted of solid type tumors and histologic arrangements of different subtypes were observed. In some specimens, more than one histologic subtype was identified in the same lesion, and each tumor was categorized according to the predominant cell pattern. The odontogenic tumors were grouped as follows: follicular ameloblastoma (n=7), plexiform ameloblastoma (n=4), acanthomatous + follicular ameloblastoma (n=3), basal cell ameloblastoma (n=2), adenomatoid odontogenic tumor (n=8). PCNA immunohistochemical expression revealed stronger quantitative labeling index for the follicular ameloblastoma, while for p53 protein the strongest quantitative labeling index was detected in the plexiform type. Nevertheless, statistical analysis using ANOVA and Tukey's test did not detect significant differences (p>0.05) among the histologic subtypes of ameloblastoma. The findings of this study suggest that the different histologic patterns of ameloblastoma did not show a direct correlation with their clinical behavior and consequently with the prognosis of the cases. The results also indicated that the ameloblastoma has greater proliferative potential than the AOT, which can contribute to explain its more aggressive and invasive characteristics.