RESUMO
PURPOSE: To evaluate the marginal microleakage and the infiltration ability of pit-and-fissure sealants by applying the conventional sealing technique in comparison to using an additional bonding agent. MATERIALS AND METHODS: Extracted non-carious permanent molars (n = 60) were first stored in sterile saline solution and then assigned to one of two groups: group C (control) was sealed (Helioseal F) by using the conventional technique, while in group BA (bonding agent), a bonding agent (OptiBond FL) was additionally applied prior to sealing. The teeth were thermocycled (1000 cycles, 5°C to 55°C, dwell time 30 s), then varnished and immersed in 5% methylene blue solution for 24 h. After embedding and sectioning each tooth into 6-12 slices, the presence of microleakage, unfilled areas, and air bubbles trapped in the sealant were assessed with a stereomicroscope. RESULTS: A higher proportion of microleakage was found under sealants applied without the additional use of the bonding agent. A statistically significant difference in microleakage was noted between the groups (p = 0.045). Regarding the presence of unfilled areas, a statistically significant difference between the groups was observed (p < 0.001), especially since no unfilled areas were found at all in the samples of the group using the bonding agent. Regarding the amount of air bubbles trapped in the sealant, no statistically significant difference was observed between the two groups (p = 0.829). CONCLUSION: Under these in vitro conditions, sealant procedures using an additional bonding agent applied beforehand significantly improved fissure infiltration and microleakage prevention significantly.
Assuntos
Colagem Dentária/métodos , Infiltração Dentária/prevenção & controle , Selantes de Fossas e Fissuras/química , Cimentos de Resina/química , Condicionamento Ácido do Dente/métodos , Corantes , Resinas Compostas/química , Esmalte Dentário/ultraestrutura , Infiltração Dentária/classificação , Fluorescência , Humanos , Processamento de Imagem Assistida por Computador/métodos , Cura Luminosa de Adesivos Dentários/instrumentação , Teste de Materiais , Azul de Metileno , Ácidos Fosfóricos/química , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
There is evidence that insulin-like growth factor-binding protein (IGFBP-2), a modulator of the actions of IGFs, also has IGF-independent effects in human tumor cell lines. These involve specific binding of IGFBP-2 to alpha5beta1-integrin, followed by alterations in the phosphorylation status of downstream signaling molecules. Previously, IGFBP-2 has also been shown to be associated with cell proliferation, adhesion and migration. Here, we investigated direct effects of IGFBP-2 on apoptosis and alterations in the expression of related proteins. The breast cancer cell line Hs578T, which shows no IGFBP-2 production of its own and is independent of the IGF-I receptor, was treated with human recombinant IGFBP-2 in order to study the changes in gene expression induced by IGFBP-2. The methods employed for this purpose were oligonucleotide microarrays, real-time RT-PCR, western blotting, and immunoassays. Out of the 440 genes covered by the Oligo GEArray Human Cancer Microarray OHS-802, the expression of 77 genes was directly influenced by IGFBP-2. By the use of real-time quantitative RT-PCR, the gene expression of Nuclear Factor (NF)kappaB, p53, transforming growth factor beta (TGF beta-1), LAMB1 (Laminin, Beta 1), Bcl-2, and IIp45 was found to be significantly upregulated (by 1.2- to 3.05-fold; all P < 0.001). Accordingly, NFkappaB, p53, and TGF beta-1 proteins, as measured by Western blotting and immunoassay, were upregulated > 1.5-fold. By using an ELISA-based and a flow cytometry-based apoptosis assay, IGFBP-2 was found to have a pro-apoptotic effect on Hs578T cells. Our results suggest that IGFBP-2-induced gene expressions are of functional significance for proliferation, cell adhesion, cell migration and apoptosis, and showed that IGFBP-2 can promote apoptosis in tumor cells independent of IGF.
Assuntos
Neoplasias da Mama/metabolismo , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Somatomedinas/metabolismo , Animais , Apoptose/genética , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Dados de Sequência Molecular , NF-kappa B/genética , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
OBJECTIVE: To investigate the role of the insulin-like growth factors (IGF) system during the differentiation of human pulp-derived fibroblasts (HPF). METHODS: Primary HPF were cultured for 24 days in DMEM medium with IGF-I or IGF-II (50 ng/ml each). Cell growth and morphology, alkaline phosphatase (ALP) activity, the concentration of free deoxypyridinoline (DPD), IGF-I, -II, IGFBP-2 and -3 were studied. The number of (125)I-IGF-I binding sites was estimated by Scatchard analysis. RESULTS: Light-microscopically visible nodules emerged during differentiation. Simultaneously, the ALP activity increased steadily between days 8 and 24, while the DPD concentration decreased by about 50%. The HPF produced high concentrations of IGF-II (2.00-1.30 microg/10(6) cells) but low IGF-I, IGFBP-2. IGFBP-2 was not changed, IGFBP-3 increased by 65% during differentiation. The number of IGF binding sites increased from 8,500 +/- 55 per cell (day 8) up to 22,000 +/- 570 (day 24). CONCLUSION: The increasing number of IGF-binding sites accompanied by alterations in the biochemical bone markers during the differentiation of HPF suggests an autocrine/paracrine role for the IGFs in the formation of dentinal hard tissue.