ABSTRACT
Background: The caveolin-1 protein (structural component of membrane caveolae) plays important roles in sev-eral biological functions, such as endocytosis, cell adhesion, and cell signaling. However, this protein has been as-sociated with mechanisms of tumorigenesis in several neoplasms. The expression patterns and roles of caveolin-1in the oral epithelium and in embryonic and odontogenic tumor tissues are still unclear.Material and Methods: The expression of caveolin-1 was evaluated in samples of the normal gingival epithelium(n=7), human tooth germ (TG) (n=12), ameloblastoma (AM) (n=83), and ameloblastic carcinoma (AC) (n=9) byimmunohistochemistry. Additionally, AM samples were analyzed by qRT-PCR and Western blot.Results: Most TG (91.7%), AM (73.5%) and AC (100%) samples showed diverse patterns of immunohistochemicalpositivity for caveolin-1, while only one gingival sample was positive. The transcript levels of cav-1 were signifi-cantly upregulated by 14.9-fold in AM tissue (P = 0.0014) compared to those in normal gingival epithelial tissue,as shown by qRT-PCR. Presence of caveolin-1 protein was confirmed by Western blot analysis. The caveolin-1immunoexpression patterns throughout the stages of TG show its importance during odontogenesis.Conclusions: The overexpression of caveolin-1 in AM and AC compared to its expression in normal gingivalepithelium (adult tissue) suggests a possible role of caveolin-1 in protumoral events, but due to the similar immu-noexpression observed in AM and AC, caveolin-1 may not necessarily participate in the malignant transformationprocess. However, future studies are needed to clarify and confirm these hypotheses.(AU)
Subject(s)
Humans , Male , Female , Ameloblastoma , Caveolin 1 , Immunohistochemistry , Odontogenic Tumors , Oral Health , Oral Medicine , Pathology, Oral , CarcinomaABSTRACT
El presente trabajo tiene como finalidad la valoración estudiantil respecto al uso de WhatsApp (WAP) y los Entornos Virtuales de Aprendizaje (EVA) en la Facultad de Odontología (FO), de la Udelar (Montevideo - Uruguay). Se realizó estudio descriptivo observacional en estudiantes de la generación 2016 - FO - UdelaR. Se utilizó una encuesta con 5 items en relación a tres aplicaciones tecnológicas (WhatsApp, Plataforma Moodle y Polimedias), fueron valorados de 0-12 puntos. En WhatsApp se consultó acerca de la posibilidad de consultar dudas, compartir imágenes, informarse, interactuar con el docente y compañeros, dando como resultado en cada item un puntaje promedio de 10.77-10.63-10.63-10.63 y 9.20 respectivamente. En EVA se consultaron los mismos ítems salvo el dos (fue acceder a presentaciones de clase), recibiendo un puntaje promedio de 8.53-11.27-10.33-9.47 y 5.53. Se percibe un alto grado de aceptación entre las diferentes tecnologías, con un mayor grado de aceptación en cuanto a la comunicación de WhatsApp frente a la plataforma Moodle.
The aim of this work was to have students evaluate the use of WhatsApp (WAP) and a Virtual Learning Environment (VLE) at the School of Dentistry, UdelaR (Montevideo - Uruguay). An observational descriptive study was conducted on students from the 2016 generation. A survey with five items was implemented, including three technological applications (WhatsApp, Moodle Platform and Polimedias), which were rated 0 to 12 points. As for WhatsApp, we asked about the possibility of clarifying doubts, sharing images, getting information, interacting with the teacher and classmates. The average score obtained was 10.77-10.63-10.63-10.63 and 9.20 for each item, respectively. In the VLE, the same items were included except for number two (access to class presentations), receiving an average score of 8.53-11.27-10.33-9.47 and 5.53. There is a high degree of acceptance of the different technologies, WhatsApp communication being more widely accepted than communication in the Moodle platform.
Subject(s)
Students, Dental , Education, DistanceABSTRACT
El objetivo de este estudio fue conocer la expresión de MCM4-5-6 en gérmenes dentarios humanos en estado de campana. Materiales y Métodos Se obtuvieron preparados histológicos de 4 maxilares fetales incluidos en parafina en el archivo de bloques de la cátedra de Histología de la Facultad de Odontología, UdelaR. Se procedió al corte de los mismos en secciones para técnica de rutina (HE) y de IHQ para MCM 4, 5 y 6. Resultados: Las diferentes regiones del órgano del esmalte mostraron 100 % de positividad en el estrato intermedio, una variación de 100 % a 0 % en el epitelio interno del órgano del esmalte, desde el sector cervical al sector incisal del mismo, y0% tanto en el retículo estrellado como en el epitelio externo del órgano del esmalte. Conclusiones: Los resultados obtenidos permitieron evidenciar y confirmar la acción proliferativa de las diferentes zonas del órgano del esmalte.
The aim of this study was to determine the expression of MCM4-5-6 in human tooth germs in the bell stage. Materials and methods: Histological samples were collected from four fetal maxillae placed in paraffin at the block archive of the Histology Department of the School of Dentistry, UdelaR. Sections were made for HE routine technique and for immunohistochemistry technique for MCM4-5-6. Results: Different regions of the enamel organ showed 100% positivity in the intermediate layer, a variation from 100% to 0% in the inner epithelium from the cervical loop to the incisal area, and 0% in the stellar reticulum as well as the outer epithelium. Conclusions: The results show and confirm the proliferative action of the different areas of the enamel organ.
Subject(s)
Tooth Germ , Cell Proliferation , Minichromosome Maintenance Complex Component 4 , Minichromosome Maintenance Complex Component 5 , Minichromosome Maintenance Complex Component 6ABSTRACT
La formación de nuevas células se genera a partir de células preexistentes a través de una serie ordenada de eventos denominada ciclo celular. El control de este es fundamental para la integridad del genoma, por lo que hay múltiples proteínas regulando este proceso. Actualmente, se conoce que el complejo MCM2-7 tiene un rol esencial en la replicación del ADN, específicamente involucrado en la proliferación, durante el ciclo celular. La identificación inmunohistoquimica de las proteínas de este complejo a nivel tisular, podría ser una herramienta muy útil, para usarlos como biomarcadores y así comprender uno de los mecanismos biológicos que se ven afectados en el cáncer. Nuestro objetivo es realizar una revisión del complejo MCM2-7, ya que estas proteínas como se ha descrito, podrían comportarse como buenos marcadores biológicos de proliferación celular, y así poder realizar un buen diagnóstico, pronóstico y futuros blancos terapéuticos de aquellas lesiones principalmente neoplásicas , principalmente las que asientan a nivel de la mucosa bucal.
New cells are formed from preexisting cells through an ordered series of events called cell cycle. As the control of this cycle is fundamental for genome integrity, multiple proteins regulate this process. We currently know that the MCM2-7 complex has a major role in DNA replication in the cell cycle, in particular regarding proliferation. The immunohistochemical identification of the proteins in this complex on tissues may be useful, as they could be used as biomarkers and would help us understand one of the biological mechanisms affected in cancer processes. Our aim is to collect the existing evidence regarding the members of the MCM2-7 complex, since these proteins could be effective biological cell proliferation markers, which would help practitioners make accurate diagnosis, prognosis and future therapeutic targets of lesions that are mainly neoplastic, especially in the oral mucosa.
Subject(s)
Cell Proliferation , Minichromosome Maintenance ProteinsABSTRACT
Background: Mismatch repair proteins (MMRPs) are a group of nuclear enzymes that participate in the repair of base mismatches that occur during DNA replication in all proliferating cells. The most studied MMRPs are hMSH2 and hMLH1, which are known to be highly expressed in normal tissues. A loss of MMRPs leads to the accumulation of DNA replication errors in proliferating cells. Ki-67 is a biomarker regarded to be the gold-standard tool for determining cell proliferation by immunohistochemical methods. The aim of this study was to investigate the immunohistochemical expression of hMLH1, hMSH2 and Ki-67 proteins in ameloblastomas and tooth germs, to contribute to the understanding of the development of this odontogenic neoplasm. Material and Methods: Immunohistochemical assays to determine the presence of proteins hMSH2, hMLH1 and Ki-67 were performed in 80 ameloblastomas (40 solid and 40 unicystic) and five tooth germs. Results: Unicystic ameloblastomas showed higher MMRP expression (hMLH1: 62.5 ± 43.4; hMSH2: 83.3 ± 47.8) than did solid ameloblastomas (hMLH1: 59.4 ± 13.5; hMSH2: 75.8 ± 40.2). Additionally, the cell proliferation index assessed by Ki-67 was inversely proportional to the expression of MMRP. Comparison between tooth germs and ameloblastoma revealed significantly higher expression of hMLH1, hMSH2 and Ki-67 in tooth germs (p=0.02). Conclusions: The differences of MMRP and Ki-67 immunoexpression between ameloblastomas and tooth germ suggest that alterations in the MMRP mechanisms could participate in the biological behavior of ameloblastomas (AU)
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Subject(s)
Humans , Male , Female , Ameloblastoma/diagnosis , Tooth Germ/pathology , Ki-67 Antigen/analysis , Immunohistochemistry/methods , ImmunohistochemistryABSTRACT
Ameloblastic fibrodentinoma (AFD) is considered a mixed odontogenic tumor that is characterized by conserved epithelial and ectomesenchymal neoplastic components. AFD is composed of long narrow cords and islands of odontogenic epithelium; the epithelial strands lie in a myxoid cell-rich ectomesenchymal tissue with stellate-shaped fibroblasts that exhibit long slender cytoplasmic extensions that resemble dental papilla. The lesions show the presence of dysplastic dentin. Although AFD is a rare entity and its very existence is not completely accepted, based on the extent of histodifferentiation, it is considered to represent a stage between ameloblastic fibroma and ameloblastic fibroodontoma. This study aimed to provide a histopathological and immunohistochemical characterization of this infrequent tumor. A large panel of antibodies including amelogenin, Ck 19, calretinin, syndecan-1, E-cadherin, MSH2, histone H3, and Ki-67 was used to illustrate the nature of the tumor.
