Abstract The aim of our study was to isolate populations of keratinocyte stem cells based on the expression of cell surface markers and to investigate whether the culture could affect their phenotype. keratinocytes from human oral mucosa were sorted based on the expression of the epithelial stem cell markers p75NTR and CD71. We also examined the co-expression of other epithelial stem markers such as integrins β1 and α6 and their stem cell-like proprieties in in vitro assays. Three passages after being sorted by MACS, more than 93% of the p75NTR+ve cells lost the expression of p75NTR, while 5.46% of the p75NTR-ve gained it. Within the small population of the p75NTR+ve cells, 88% co-expressed other epithelial stem cell markers such as integrins β1 and α6, while only 28% of p75NTR-ve cells co-expressed these markers. These results were confirmed by sorting cells by FACS. Additionally, when double staining was used for sorting cells, 99% of the p75NTR+veCD71-ve and 33% of the p75NTR-veCD71+ve cells expressed both integrins, but just one week after culture, only 1.74% of the p75NTR+veCD71-ve cells still expressed p75NTR and only 0.32% still expressed CD71. Similar results were obtained when co-culturing p75NTR+ve and p75NTR-ve populations before analysis. Our results suggest that phenotype changes may be part of an intrinsic cellular mechanism to conserve levels of protein expression as they may found in the human body. In addition, in vitro culture may not offer ideal conditions for epithelial stem cell maintenance due to phenotype changes under standard culture conditions.
Abstract Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evaluated the immunohistochemical expression of CD90(Thy-1) and P75NTR stem cell markers in multicystic and unicystic ameloblastomas. Seventeen (17) samples of ameloblastomas (multicystic, n = 10; unicystic, n = 7) were submitted to immunohistochemical reactions and graded semi-quantitatively. The Kolmogorov-Smirnov test was used to verify possible differences in CD90 and P75NTR expressions between multicystic and unicystic ameloblastomas (p < 0.05). CD90 immunostaining was observed in all multicystic ameloblastoma specimens (n = 10), in the cytoplasm of the fibroblasts and vascular endothelial cells of the tumor stroma, near the neoplastic odontogenic epithelia. The staining of stromal CD90 was significantly higher in multicystic than in unicystic ameloblastomas (p = 0.003). Nuclear P75NTR immunostaining was observed in all ameloblastoma specimens. A significant difference was seen in the epithelial staining of P75NTR between multicystic and unicystic types (p = 0.007). The increased expression of CD90 and P75NTR found in multicystic ameloblastomas suggests a behavioral biological difference between multicystic and unicystic ameloblastomas, as well as a difference in ameloblastoma development.
INTRODUCTION: Dental fluorosis is a disturbance of high prevalence caused by the ingestion of fluoride ions present mainly in toothpaste. Preventive measures to avoid it are still controversial. Thus, knowing the impact that fluorosis can cause on the population's quality of life it is important for planning public health policies.OBJECTIVE: To evaluate the impact of dental fluorosis on the quality of life of children and adolescents.MATERIAL AND METHOD: We studied 300 subjects aged 8 to 12 years divided into 4 groups: children (8-10 years) and adolescents (10 to 12 years) with and without fluorosis. The diagnosis of fluorosis was performed according to the index Thylstrup and Fejerskov and quality of life was evaluated using Child Perceptions Questionnaire 8-10 and 11-14. The socio-demographic characteristics of the patients were also evaluated. For inclusion in the sample, selected patients should present eight permanent incisors with crowns fully erupted. Patients who had extensive restorations, fractured teeth, other dental enamel defects and who wore braces were excluded.RESULT: Fluorosis was present in 64.7% of the patients analyzed and in most cases (80.3%) was mild or very mild. In children, the average overall score of the questionnaire was 15.9 for the group without fluorosis and 18.3 for the group with fluorosis (p = 0.255). The teenagers' score in the group without fluorosis was 26.1, while the group with fluorosis was 22.7 (p = 0.104).CONCLUSION: Dental fluorosis caused impact on the quality of life of the population analyzed only in the functional domain.
INTRODUÇÃO: A fluorose dentária é um distúrbio de alta prevalência decorrente da ingestão de íons fluoretos. Medidas preventivas para evitá-la ainda são controversas. Assim, conhecer o impacto que a fluorose pode causar na qualidade de vida de indivíduos é importante para o planejamento de políticas públicas de saúde.OBJETIVO: Avaliar o impacto da fluorose dentária sobre a qualidade de vida relacionada à saúde bucal (QVRSB) de crianças e adolescentes.MATERIAL E MÉTODO: Foram avaliados 300 indivíduos na faixa etária de 8 a12 anos. O diagnóstico de fluorose foi realizado segundo o índice Thylstrup e Fejerskov e a qualidade de vida foi avaliada utilizando os questionários de Percepção da Criança 8-10 e 11-14. Foram incluídos pacientes com oito incisivos permanentes com coroas totalmente irrompidase excluídos os que apresentavam restaurações extensas, dentes fraturados, outros defeitos do esmalte dentário e os que usavam aparelho ortodôntico fixo. Os dados foram analisados no programa SPSS(r) (versão 18; Chicago, IL) e realizaram-se os teste Qui-quadrado, Fisher e Mann-Whitney. Foram considerados significantes valores de p<0,05.RESULTADO: A prevalência de fluorose foi 64,7%, sendo os graus leve e muito leve responsáveis por 80,3% dos casos. Crianças e adolescentes não tiveram impacto na QVRSB no escore geral e domínios sintomas orais, bem-estar emocional e social (p>0,05). Entretanto, apresentaram impacto no domínio limitação funcional (p = 0,039 e 0,013) para crianças e adolescentes respectivamente).CONCLUSÃO: Foi observada associação entre fluorose e qualidade de vida apenas no domínio funcional.
Dental pulp has been identified as a novel and promising stem cell source. The following systematic review presents and summarises in vivo studies that have used stem cells from the dental pulp of permanent and deciduous teeth to repair or regenerate non-dental tissues. An electronic customised search was performed using 4 different databases (Entrez PubMed, Cab Abstracts, Scopus and Web of Science). Only full-text research manuscripts published in English between the years of 2000 and 2012 were included. The manuscripts were retrieved based on the following keywords and/or abbreviations: [Stem Cells from Human Exfoliated Deciduous teeth (SHED)] AND/OR [Dental Pulp Stem Cells (DPSC)] AND [tissue regeneration] AND [tissue repair]. Only manuscripts involving in vivo applications of SHED or DPSC for the repair and/or regeneration of non-dental tissues were included. The search strategy produced 2309 papers, from which 14 were eligible according to the predetermined inclusion and exclusion criteria. Although human tissue was the source of cells in half of the studies included in our review, all of the studies involved transplantation into animals of other species, such as pigs, rats and mice. Most of the manuscripts reported the successful use of DPSCs or SHED for non-dental tissue repair or regeneration. While these cell populations represent promising alternative sources of stem cells for tissue engineering and cell-based regenerative medicine therapies, it is not yet possible to guarantee the appropriate clinical management of this technique.
PURPOSE: To analyze the effects of aqueous ozone irrigation over bone healing in hyperglycemia-induced rats. METHODS: Forty-eight male Wistar rats were allocated into Group H (hyperglycemic) or Group N (control). Monocortical bone wound were performed on femurs' anterolateral face. Wounds were treated with a trans-operatory single irrigation of 100ml of aqueous ozone [0.004mg/ml] whereas control groups received 100ml of pure water (Milli-Q®). Histomorphological and histomorphometrical analyses were accomplished after seven, 14 and 21 days. Kruskal-Wallis and Mann-Whitney statistical tests were applied for bone neoformation quantification and assessment. RESULTS: Aqueous ozone wounds irrigated revealed diffuse hemorrhage and increased neoformed of blood vessels number. There was no statistical significant difference in bone trabeculae neoformation. After seven and 14 days, the number of osteoclasts was higher in aqueous ozone groups than in those treated with pure water. CONCLUSION: Independently of blood glucose levels, aqueous ozone allowed an increase in blood vessels neoformation and osteoclast migration, without affect bone trabeculae neoformation.
Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor.