RESUMEN
AIM: The purpose of this study is to present data on a series of peripheral odontogenic fibroma, WHO (World Health Organization)-type (POF), in Brazilians and to compare the results with previously reported studies. METHODS: The study sample was made from the number of POF cases and its synonymies diagnosed from 1950 to 2004 at the Oral Pathology Service of the Federal University of Minas Gerais. The cases were reviewed in hematoxylin-eosin stain and the histological features were evaluated in accordance with the classification WHO. Patient's data about gender, age and race and the lesion's clinical data were obtained from the biopsy request forms, after the definite diagnosis of POF. RESULTS: Seventeen diagnoses of POF were found. Data showed that POF has a higher prevalence in females (88.2%), occurring in the second and fourth decades of life (29.4% each), and in Caucasians (64.7%). The most common location was the posterior region of the mandible (41.1%). It was an asymptomatic lesion (23.5%) with an average size of 1.1 to 2.0 cm (35.2%). The histological findings were: 1) fibroblastic tissue high cellularity (58.8%); 2) scarce odontogenic epithelium (64.7%); 3) inflammation (94.1%) and 4) absence of calcification (58.8%). CONCLUSIONS: Clinical and histological data of POF in Brazilians showed important characteristcs for its diagnosis. This epidemiological data will generate a substantial contribution to the clinical, histological diagnosis and behavior of this lesion.
Asunto(s)
Fibroma/patología , Neoplasias Maxilomandibulares/patología , Tumores Odontogénicos/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Brasil , Niño , Femenino , Fibroma/clasificación , Humanos , Neoplasias Maxilomandibulares/clasificación , Masculino , Persona de Mediana Edad , Tumores Odontogénicos/clasificación , Estudios RetrospectivosRESUMEN
Uptake by the dopamine transporter (DAT) is the primary pathway for the clearance of extracellular dopamine (DA) and consequently for regulating the magnitude and duration of dopaminergic signaling. Amphetamine (AMPH) has been shown to decrease simultaneously DAT cell-surface expression and [(3)H]DA uptake. We have shown that insulin and its subsequent signaling through the phosphatidylinositol 3-kinase (PI3K)-dependent pathway oppose this effect of AMPH by promoting increased cell-surface expression. Here, we used human embryonic kidney 293 cells stably expressing the human DAT (hDAT cells) to investigate the downstream cellular components important for this effect of insulin. Akt is a protein kinase effector immediately downstream of PI3K. Both overexpression of a dominant-negative mutant of Akt (K179R) and the addition of 1-(5-chloronaphthalene-1-sulfonyl)-1H-hexahydro-1,4-diazepine HCl (ML9), a pharmacological inhibitor of Akt, decreased cell-surface expression of DAT, suggesting a role of basal Akt signaling in the homoeostasis of DAT. Moreover, expression of a constitutively active Akt mutant reduced the ability of AMPH to decrease hDAT cell-surface expression as well as [(3)H]DA uptake. In contrast, overexpression of K179R blocked the ability of insulin to oppose AMPH-induced reduction of hDAT cell-surface expression and [(3)H]DA uptake, as did ML9. Our data demonstrate that hDAT cell-surface expression is regulated by the insulin signaling pathway and that Akt plays a key role in the hormonal modulation of AMPH-induced hDAT trafficking and in the regulation of basal hDAT cell-surface expression.