Efeitos da toxicidade sistêmica produzida pelo flúor: estudo em modelo animal / Effects of systemic toxicity produced by fluoride: in vivo study

Este estudo buscou verificar possíveis alterações sistêmicas causadas pelo flúor administrado em diferentes concentrações. Foi utilizado um modelo de estudo animal, no qual foram selecionados 60 rattus norvegicus, aleatoriamente divididos em 4 grupos, sendo três grupos testes (receberam água fluoretada nas concentrações de 0,7 ppm F; 1,2 ppm F e 2,0 ppm F), e um grupo controle que recebeu água destilada. Para análise histomorfológica por microscopia óptica, os ratos foram submetidos a dissecação dos seguintes órgãos: intestino alto (duodeno), rim e fígado. Os resultados obtidos após a avaliação descritiva comparativa dos grupos de estudo evidenciaram alterações morfológicas em todos os grupos testes, concluindo, desta forma, que o flúor administrado, nestas concentrações, pode ser tóxico.

This study sought to verify possible systemic changes caused by fluoride administered at different concentrations. An animal model was used in which 60 rattus norvegicus were randomly divided into 4 groups, with three test groups receiving fluoridated water at the different concentrations (0.7 ppm F, 1.2 ppm F and 2, 0 ppm F), and a control group receiving distilled water. A histomorphological analysis was performed by light microscopy after the dissection of the following rat organs: the large intestine (duodenum), the kidney and the liver. The results obtained after the comparative descriptive evaluation of the study groups showed morphological changes in all the test groups, concluding that the fluoride administered at these concentrations could be toxic.

Cell proliferation markers at the invasive tumor front of oral squamous cell carcinoma: comparative analysis in relation to clinicopathological parameters of patients.

OBJECTIVES: To evaluate the number of AgNORs per nucleus and the expression of Ki-67 at the tumor invasion front (TIF) in relation to clinical parameters (TNM), TIF classification and the prognosis of oral squamous cell carcinomas in an Uruguayan population. MATERIAL AND METHODS: This study was conducted through a retrospective survey from 2000 to 2010 at the National Institute of Cancer Montevideo, Uruguay and included 40 patients. The samples were obtained from the resection of the tumor and the TIF was defined according with Bryne, et al.5 (1992). Expression of Ki-67 was assessed by the percentage of positive tumor cells and the AgNOR was recorded as the mean AgNOR (mAgNOR) and the percentage of AgNOR per nucleus (pAgNOR). All analyzes were performed by a blinded and calibrated observer. RESULTS: No statistically significant association was observed between immunostaining of Ki-67 and AgNOR with the different types of TIF, regional metastasis and patients prognosis, however it was observed an increase in Ki-67 expression associated with worse patient's clinical staging, although not statistically significant. CONCLUSIONS: Our results suggest that proliferation markers as AgNOR and Ki-67 are not prognostic markers at the tumor invasive front of carcinoma of oral squamous cell.

Prevalence of oral lesions diagnosed at the ULBRA Canoas of Dental Diagnosis Service / Prevalência das lesões bucais observadas no Serviço de Diagnóstico Bucal da ULBRA Canoas

Objective: To evaluate the prevalence of oral lesions diagnosed at the ULBRA Canoas of Dental Diagnosis Service, from 2010 to 2016. Methods: This is a cross-sectional descriptive study based on the analysis of the biopsy files, filed in the Laboratory of Histology of ULBRA Canoas. A database was created with all the information collected in the biopsy record and the analysis of the data was performed by the STATA data processor. Results: The sample consisted of 405 patients, mean age was 45.7 years (18.6%); The majority of the patients were female (52.0%); and caucasian (81.2%). The majority of the lesions presented rosea staining (25.7%), defined limits and sessile base (32.6%), firm consistency (25.4%). The most frequent groups of oral lesions were: soft tissue neoplasms (20.5%), reactional lesions (17.5%), periapical pathologies (11.8%) and potentially malignant lesions (11.8%). Among the soft tissue neoplasms the most prevalent were fibroma (43.4%) and papiloma (31.3%). Conclusion: Thus, this study emphasizes the importance of knowledge by dentistry on the prevalence of oral lesions in the metropolitan region of Porto Alegre, such knowledge is essential for oral health care actions to be based on the epidemiological profile and frequency of lesions observed in this population.

Objetivos: Avaliar a prevalência de lesões bucais observadas no Serviço de Diagnóstico Bucal da ULBRA Canoas no período de 2010 a 2016. Métodos: estudo transversal descritivo a partir da análise das fichas de biópsia arquivadas no laboratório de Histologia da ULBRA Canoas. Foi criada uma base de dados com todas as informações coletadas na ficha de biópsia e a análise dos dados foi realizada pelo processador de dados STATA. Resultados: A amostra foi composta por 405 pacientes, média de idade foi de 45,7 anos (18,6%); a maioria dos pacientes era do sexo feminino (52,0%); e de raça branca (81,2%). O tipo de biópsia de maior prevalência foi a excisional/total (78,3%) A maioria das lesões apresentavam coloração rósea (25,7%), limites definidas e base séssil (32,6%), consistência firme (25,4%) e superfície lisa (46,4%), por fim, os grupos mais frequentemente encontrados de lesões bucais foram: neoplasias de tecido mole 83 (20,5%), lesões reacionais 71 (17,5%), patologias periapicais 48 (11,8%) e lesões potencialmente malignas 48 (11,8%). Dentre as neoplasias de tecido mole as mais prevalentes foram fibroma 36 (43,4%) e papiloma 26 (31,3%). Conclusão: Este estudo ressalta a importância do conhecimento pelos cirurgiões-dentistas sobre a prevalência de lesões bucais na região metropolitana de Porto Alegre, com intuito de promover ações de assistência à saúde bucal, que possam estar baseadas no perfil epidemiológico e na frequência das lesões observadas nesta população.

Cell proliferation markers at the invasive tumor front of oral squamous cell carcinoma: comparative analysis in relation to clinicopathological parameters of patients

Abstract Objectives To evaluate the number of AgNORs per nucleus and the expression of Ki-67 at the tumor invasion front (TIF) in relation to clinical parameters (TNM), TIF classification and the prognosis of oral squamous cell carcinomas in an Uruguayan population. Material and Methods This study was conducted through a retrospective survey from 2000 to 2010 at the National Institute of Cancer Montevideo, Uruguay and included 40 patients. The samples were obtained from the resection of the tumor and the TIF was defined according with Bryne, et al.5 (1992). Expression of Ki-67 was assessed by the percentage of positive tumor cells and the AgNOR was recorded as the mean AgNOR (mAgNOR) and the percentage of AgNOR per nucleus (pAgNOR). All analyzes were performed by a blinded and calibrated observer. Results No statistically significant association was observed between immunostaining of Ki-67 and AgNOR with the different types of TIF, regional metastasis and patients prognosis, however it was observed an increase in Ki-67 expression associated with worse patient's clinical staging, although not statistically significant. Conclusions Our results suggest that proliferation markers as AgNOR and Ki-67 are not prognostic markers at the tumor invasive front of carcinoma of oral squamous cell.

Expression of E-cadherin and involucrin in leukoplakia and oral cancer: an immunocytochemical and immunohistochemical study.

To assess the immunocytochemical and immunohistochemical correlation of adhesion (E-cadherin) and cell differentiation (involucrin) molecules in oral leukoplakia and oral squamous cell carcinoma. Cytological samples and biopsies were obtained from male and female patients aged over 30 years with oral leukoplakia (n = 30) and oral squamous cell carcinoma (n = 22). Cell scrapings and the biopsy were performed at the site of the lesion and histological slides were prepared for the immunocytochemical analysis of exfoliated oral mucosal cells and for the immunohistochemical analysis of biopsy tissues using E-cadherin and involucrin. Spearman's correlation and kappa coefficients were used to assess the correlation and level of agreement between the techniques. Immunostaining for E-cadherin and involucrin by both techniques was similar in the superficial layers of the histological sections compared with cell scrapings. However, there was no statistical correlation and agreement regarding the immunocytochemical and immunohistochemical expression of E-cadherin and involucrin in oral leukoplakia (R = 0.01, p = 0.958) (Kappa = 0.017, p = 0.92) or in oral squamous cell carcinoma (R = 0.26, p = 0.206) (Kappa = 0.36, p = 0.07). The immunoexpression of E-cadherin and involucrin in tissues is consistent with the expression patterns observed in exfoliated oral mucosal cells, despite the lack of a statistically significant correlation. There is an association of the histopathological characteristics of leukoplakia with the expression E-cadherin and of the microscopic aspects of oral squamous cell carcinoma with immunohistochemical expression of involucrin.

Expression of E-cadherin and involucrin in leukoplakia and oral cancer: an immunocytochemical and immunohistochemical study

Abstract To assess the immunocytochemical and immunohistochemical correlation of adhesion (E-cadherin) and cell differentiation (involucrin) molecules in oral leukoplakia and oral squamous cell carcinoma. Cytological samples and biopsies were obtained from male and female patients aged over 30 years with oral leukoplakia (n = 30) and oral squamous cell carcinoma (n = 22). Cell scrapings and the biopsy were performed at the site of the lesion and histological slides were prepared for the immunocytochemical analysis of exfoliated oral mucosal cells and for the immunohistochemical analysis of biopsy tissues using E-cadherin and involucrin. Spearman’s correlation and kappa coefficients were used to assess the correlation and level of agreement between the techniques. Immunostaining for E-cadherin and involucrin by both techniques was similar in the superficial layers of the histological sections compared with cell scrapings. However, there was no statistical correlation and agreement regarding the immunocytochemical and immunohistochemical expression of E-cadherin and involucrin in oral leukoplakia (R = 0.01, p = 0.958) (Kappa = 0.017, p = 0.92) or in oral squamous cell carcinoma (R = 0.26, p = 0.206) (Kappa = 0.36, p = 0.07). The immunoexpression of E-cadherin and involucrin in tissues is consistent with the expression patterns observed in exfoliated oral mucosal cells, despite the lack of a statistically significant correlation. There is an association of the histopathological characteristics of leukoplakia with the expression E-cadherin and of the microscopic aspects of oral squamous cell carcinoma with immunohistochemical expression of involucrin.

Toxic effects of carbamide peroxide on the dentin-pulp complex / Efeitos tóxicos produzidos pelo peróxido de carbamida sobre o complexo dentino-pulpar

The objective of the present study was to evaluate the toxicity of carbamide peroxide on the dentin-pulp complex in the teeth of young, male rats using this medication in different doses that are considered clinical and subclinical. The methodology used was a comparative histological analysis between the control group and the test groups. The test groups were characterized by the ingestion of carbamide peroxide, in different concentrations, in the water supplied to them for a period of 40 days. The concentrations were: 1.9 mg/ml (test 1), 0.95 mg/ml (test 2), 0.71 mg/ml (test 3), 0.47 mg/ml (test 4) and 0.24 mg/ml (test 5). The results in the test groups showed a decrease in the odontoblast layer as well as changes in its morphology, and thickening of the pre-dentin layer. This demonstrates that different concentrations of carbamide peroxide may cause signifi cant changes in the dentin-pulp complex.

O objetivo deste estudo foi avaliar a toxicidade do peróxido de carbamida sobre o complexo dentino-pulpar de dentes de ratos machos jovens, com o uso desta medicação em diferentes doses consideradas clínicas e subclínicas. A metodologia utilizada foi uma análise histológica comparativa entre o grupo controle e grupos testes, que se caracterizavam pela ingestão de peróxido de carbamida na água de abastecimento em diferentes concentrações: 1,9 mg/ml (teste1), 0,95 mg/ml (teste 2), 0,71 mg/ml (teste 3), 0,47 mg/ml (teste 4) e 0,24 mg/ml (teste 5) durante um período de 40 dias. Os resultados mostraram que os grupos testes apresentavam uma diminuição na camada de odontoblastos, assim como alterações na sua morfologia e espessamento da camada de pré-dentina, demonstrando que o peróxido de carbamida em diferentes concentrações pode provocar alterações signifi cativas no complexo dentino-pulpar.

Seminário de Integração como Dispositivo Pedagógico de Inovação Curricular no Ensino da Saúde: a Percepção do Estudante sobre o Paciente / Integration Seminars as Pedagogical Devices for Curricular Innovation in Health Education: Student Perceptions of Patients

RESUMO Pesquisa exploratória documental de abordagem qualitativa cujo objetivo foi compreender como está se constituindo a formação do estudante de Odontologia em relação ao cuidado em saúde, a partir de uma atividade de ensino interdisciplinar ocorrida no segundo ano da formação do cirurgião-dentista. Foi realizado um levantamento retrospectivo do material produzido pelos estudantes do terceiro semestre do curso de Odontologia da Universidade Federal do Rio Grande do Sul, no Seminário de Integração IV, de 2006 a 2013. O corpus de análise foi formado por relatos de acompanhamento de pacientes e narrativas. Foram analisados 95 relatos de casos de pacientes e 67 narrativas pelo método da análise temática de conteúdo de Bardin. A análise do material resultou em 17 unidades de significação/categorias emergentes. A inclusão das narrativas no Seminário de Integração como estratégia metodológica de ensino na saúde trouxe a qualificação dos relatos e aproximou os estudantes do ser humano a ser cuidado, passando por sua queixa principal, história de vida e subjetividades. Currículos inovadores e integrados na área da saúde devem ser acompanhados permanentemente com base na experiência concreta nesta e em outras instituições de educação superior do País.

ABSTRACT This documentary exploratory research project with a qualitative approach aimed to understand how dental students are being trained in terms of healthcare, by means of an interdisciplinary teaching activity held in the second year of dental school. A retrospective survey was performed from the material produced by the students during the third semester of the dentistry course at the Federal University of Rio Grande do Sul, by means of the IV Integration Seminar held in 2006-2013. The analysis corpus consisted of reports featuring patient monitoring and narratives. We analyzed 95 patient case reports and 67 narratives using the thematic analysis method on Bardin content. Analysis of the material resulted in 17 meaning units/emerging categories. The inclusion of narratives in the Integration Seminar as a methodological strategy for health education facilitated the qualification of reports and brought students closer to the human beings under care, by means of exposing the students to the patients’ chief complaint, life history and subjective factors. The specific experiences of this study as well as those of other Brazilian educational institutions suggest that innovative and integrated curricula in the healthcare field must be implemented on a permanent basis.

Immunopathological response in external dental resorption / Resposta imunopatológica das reabsorções dentárias externas: revisão da literatura

The study of root resorption and its immunopathogenesis is extremely important for preserving teeth within the oral cavity. Resorption may be infl ammatory or by substitution and it can be triggered by traumatism, induced movement of teeth, periapical disease, periodontal treatment and whitening of non-vital teeth. During odontogenesis, dentin is protected from the immune system and later this protection is provided externally by the cementum, cementoblasts and enamel and internally by the odontoblastic layer. After the process of deciduous root resorption, dentin proteins that have not been yet been presented to the immune system become sequestered antigens that can induce autoimmune responses and play a role in etiopathogenesis of dental resorption. When their protective barriers are missing, hormones and cells that are present during infl ammatory processes induce activation of clasts which, when unbalanced, no longer perform physiological bone remodeling and begin to provoke an immunopathological response that causes dental resorption. The main objective of this paper is to present the results of a review of the literature, discussing and elucidating important aspects of external root resorption and conducting an in-depth study of the role of immunopathological response in resorption.

O estudo das reabsorções radiculares e a sua imunopatogenia são de suma importância para a manutenção dos órgãos dentários na cavidade bucal. As reabsorções são de caráter infl amatório ou por substituição, sua ocorrência pode ser conseqüência de traumatismos, movimentação dentária induzida, periapicopatias, tratamento periodontal e clareamento de dentes sem vitalidade. Na odontogênese, a dentina fi ca protegida do sistema imunológico, posteriormente, essa proteção é dada, externamente: pelo cemento, cementoblastos e esmalte; internamente pela camada odontoblástica. Após o processo de rizólise, as proteínas da dentina, que não foram apresentadas ao sistema imunológico, tornam-se um antígeno seqüestrado, o qual pode induzir respostas auto-imunes e participar da etiopatogenia das reabsorções dentárias. Na ausência de suas barreiras de proteção os hormônios e células presentes no processo infl amatório induzem a ativação dos clastos que, em desequilíbrio, deixam de sofrer a remodelação óssea fi siológica para promover uma resposta imunopatológica produzindo as reabsorções dentárias. Diante isto, o objetivo principal deste trabalho é, por meio de uma revisão na literatura, discutir e esclarecer aspectos importantes acerca das reabsorções radiculares externas, bem como um estudo aprofundado sobre a resposta imunopatológica das reabsorções.

A influência das células mioepiteliais benignas no potencial de invasão do adenocarcinoma ductal: estudo in vitro / The influence of the benign myoepithelial cells in the invasive potential of ductal adenocarcinoma: in vitro study

A invasão tumoral é um complexo processo biológico influenciado não só pelas células tumorais como também pelas células do microambiente. Dentre elas, as células mioepiteliais parecem modular negativamente o crescimento e a invasão tumoral por promover a regulação da progressão do ciclo celular além de secretar altos níveis de moléculas supressoras de tumor, como inibidores de proteinases e inibidores angiogênicos. O objetivo deste trabalho foi avaliar a influência das células mioepiteliais (CM) neoplásicas benignas do adenoma pleomórfico de glândula salivar no potencial de invasão das células epiteliais malignas do adenocarcinoma ductal (AD) por meio de ensaios de invasão in vitro utilizando a técnica de cultivo celular. Para isso, células do AD (HS578T, ATCC) foram cultivadas no compartimento superior de câmaras transwell sobre insertos com membranas (poros de 8µm) cobertas por Matrigel. No grupo controle, foi utilizado meio DMEM e nos grupos experimentais, meios condicionados de 3 culturas primárias de CM (AP3, AP4 e AP8). Após 48 horas, foi realizada a análise quantitativa do índice de invasão das células malignas e do número absoluto de células que invadiram. Os resultados evidenciaram que as células do AD apresentaram índice de invasão de 42,02% e, quando suplementadas com meio condicionado de CM, este foi de 25,77% (AP4), 26,77% (AP8) e 34,63% (AP3), com diferença estatisticamente significante (p<0,05) entre todos os grupos e o grupo controle, além de uma redução no número de células que invadiram de 523,66 no grupo controle para 233,5 (AP4), 183,5 (AP8) e 34,63 (AP3), porém esta redução não mostrou diferença estatística (p>0,05) entre todos os grupos. Concluiu-se que o meio condicionado de CM pode apresentar um papel supressor no processo de invasão in vitro das células do AD

Tumoral invasion is a complex biologic process influenced not only by tumoral cells but by cells in the microenvironment as well. Among these, the myoepithelial cells appear to negatively modulate tumor growth and invasion by promoting regulation of cell cycle progression, in addition to secreting high levels of tumor suppressor molecules, such as protease inhibitors and angiogenesis inhibitors. The aim of this study was to evaluate the influence of benign myoepithelial cells of pleomorphic adenoma of the salivary gland (MC) on the invasion potential of malignant epithelial cells of ductal adenocarcinoma (DA) by means of an in vitro invasion assay method using the cell culture technique. For this purpose, cells from the DA (HS578T, ATCC) were grown in DMEM medium in the top compartment of the Transwell chamber on inserts with filters (8µm pore size) covered with Matrigel. Conditioned medium of 3 strains of primary cultures of MC was added. After 48 hours, a quantitative analysis of the invasion rate of malignant cells and absolute number of cells that invaded was performed. The results showed that the DA cells presented an invasion rate of 42.02% and when supplemented with conditioned medium of the MC the rates were 25.77% (AP4), 26.77% (AP8) and 34.63% (AP3) and this difference being statistically significant (p<0,05) in all groups, beyond a reduction in the absolute number cells that invaded, from 523.63 in the control group to 233.4 (AP4), 183.5 (AP8) and 316.83 (AP3), however this reduction being not statistically significant (p>0,05) in all groups. It was concluded that conditioned medium of the MC could play a suppressive role in the invasion process in vitro of DA cells