NADPH-oxidase-derived ROS alters cell migration by modulating adhesions dynamics.

BACKGROUND INFORMATION: Cell migration requires the coordinated activation of structural and signalling molecules, such as the RhoGTPase Rac1. It is known that the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex assembly, which generates reactive oxygen species (ROS) at the cell membrane, also relies on Rac1 activation, indicating a possible effect of ROS during cell migration. In this study, we evaluated the effect of NADPH-oxidase-derived ROS on the migration process. RESULTS: Using time-lapse videos of CHO.K1 cells plated on fibronectin (2 µg/ml) or collagen (5 µg/cm2 ), we observed that depletion of ROS by N-acetyl-cysteine (NAC, 10 mM), an unspecific antioxidant, or diphenyliodonium (DPI, 10 µM), a NADPH-oxidase inhibitor, induced a ∼50% decrease in migration speed and severely impacted migration directionality. Then, we analysed the effects of NADPH oxidase on three migratory events: protrusion rate, adhesion process and signalling pathways related to cell migration. DPI induced an increase of ∼3 protrusion/cell, which were 2× faster but had a ∼50% retraction when compared with control. By pull-down assay, we observed no changes on Rac1 activation, indicating that ROS-mediated effects were related to downstream molecules, such as adhesion-related molecules. A reduction of the adhesion marker FAK-Y397 levels in cells treated with NAC and DPI was observed. In order to analyse adhesion dynamics, CHO.K1 cells transfected with paxillin-GFP analysed with total internal reflectance fluorescence (TIRF) indicated that DPI (5 µM) induced larger adhesions when compared with control. CONCLUSION: These results indicate that the local generation of NADPH-oxidase-derived ROS can modulate cell migration due to changes on adhesion dynamics and signalling. SIGNIFICANCE: This study highlights the physiological requirement of ROS for cell migration and the potential use of these molecules as targets to modulate the cell migration process at different diseases.

Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma.

Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization.

A importância de um protocolo preventivo no atendimento odontológico de pacientes fissurados: uma revisão sistemática da literatura / The importance of a preventive protocol in dental care of patients with cleft lip and palate: a systematic review of literature

Objetivo: O objetivo deste estudo foi revisar sistematicamente na literatura publicações relacionadas ao protocolo de atendimento do cirurgião-dentista frente a pacientes com fissura labiopalatal. Métodos: Foram revisados artigos publicados até março de 2018, nas línguas inglesa, portuguesa e espanhola, obtidos por meio de buscas nas bases eletrônicas PubMed, Scopus, LILACS, Bireme, SciELO e busca manual nas referências dos artigos encontrados. Resultados: A busca resultou em 141 artigos, onde após a aplicação dos critérios de exclusão foram obtidos quatro artigos. Os artigos selecionados eram de revisão de literatura, o que impossibilitou a realização de uma revisão sistemática da literatura. Todos os artigos foram lidos na íntegra e resultaram em um protocolo de atendimento dividido de acordo com as fases de erupção dental, com ênfase na prevenção. O protocolo foi separado em: fase pré-eruptiva e de dentição decídua, dentadura mista e dentição permanente. Na fase pré-eruptiva e de dentição decídua a orientação é dar ênfase na prevenção, na fase de dentadura mista tem-se o início da ortodontia preventiva além da manutenção das ações preventivas e na fase de dentição permanente trabalha-se novamente com a prevenção inicia-se a ortodontia fixa e quando necessário a realização de cirurgia ortognática. Conclusão: Em relação aos achados, fica evidente a importância da prevenção durante todas as fases, visando a manutenção do perímetro da arcada, e manutenção da integridade dos dentes permanentes. O cirurgião-dentista deve estar apto a realizar o atendimento tendo como base um protocolo para efetuar o manejo correto conforme a faixa etária e a fase de erupção dental em que o paciente se encontra. O aprimoramento do cirurgião-dentista na abordagem aos pacientes portadores de fissura labiopalatal deve ser constante, bem como a criação de vínculo afetivo com o paciente e a família visando um tratamento preciso e humanizado. (AU)

Aim: This study sought to systematically review publications in the literature related to the Dentist's Protocol as regards palatal cleft patients. Methods:This study reviewed articles published up to March 2018, in English, Portuguese, and Spanish, obtained through data searches on PubMed, Scopus, LILACS, Bireme, SciELO, as well as through a manual search in the references of the identified articles. Results: The search resulted in 141 articles; after the application of the exclusion criteria, four articles were selected. The selected articles were literature reviews, making it impossible to conduct a systematic review of the literature. All of the obtained articles were read in full, resulting in a care protocol that was divided according to the dental eruption stages, with emphasis on prevention. The protocol was divided into: the pre-eruptive and deciduous dentition stage, mixed denture, and permanent dentition. In the pre-eruptive and deciduous dentition stage, the dental advice is to emphasize prevention; in the mixed dentition stage, there is the beginning of preventive orthodontics as well as the maintenance of preventive actions; while in the permanent dentition stage, one again works with prevention. fixed orthodontics is begun, and when necessary, orthognathic surgery is also applied. Conclusion: Regarding the findings, the importance of prevention during all stages is clear, in an attempt maintain the perimeter of the dental arch and the integrity of the permanent teeth. The dentist should be able to perform the service based on a protocol for the correct handling according to the age range and dental eruption stage of the patient. The improvement of the dentist in providing dental care to patients with cleft lip and palate should be constant, as should the creation of an affective bond with the patient and the family, aimed at providing a precise and humanized treatment. (AU)

Odontogenic tumors: a 14-year retrospective study in Santa Catarina, Brazil.

Odontogenic tumors (OTs) are lesions that develop exclusively on maxillary bones, and form a heterogeneous group. They vary from hamartomatous lesions to benign and malign tumors. Although they are rarely observed in dentistry clinics, it is extremely important for the dentist to be aware of them. The aim of this study was to investigate the incidence of odontogenic tumors diagnosed in the population of Florianópolis, Santa Catarina, Brazil. Cases of odontogenic tumors were selected from the anatomopathological diagnostic services at Federal University of Santa Catarina from 1998 to 2011. Clinical data on these cases were collected from biopsy reports and patient files. Seventy-eight cases of odontogenic tumors were surveyed. Of these diagnoses, 51% were keratocystic odontogenic tumors (KCOTs); the remaining cases were mainly ameloblastomas and odontomas. The most frequently observed lesion in this retrospective study was KCOT (more than half of cases). Thus, this study shows that modifying the classification of the OTs altered the frequency of the lesions, possibly making KCOT the most common lesion observed in diagnostic services worldwide.

Cell block technique as an additional tool in the diagnosis of ameloblastoma.

The objective of this study was to evaluate the cytological content of ameloblastomas of the jaw. Nine cases of ameloblastoma were punctured, and the intralesional material was processed using the cell block technique. After centrifugation, the pellet obtained from the punctured material was fixed in formaldehyde and routinely processed to inclusion in paraffin. The obtained sections were stained with haematoxylin and eosin (H&E). Immunohistochemical reactions against anti-pan-cytokeratin (AE1/AE3) were performed to measure the presence of epithelial cells. Cytological analyses of the obtained slides revealed the presence of epithelial cells (as evidenced by AE1/AE3 labelling) and acellular amorphous eosinophilic materials. These cytological findings, in light of clinical and imaging data, can be helpful in the presumptive diagnosis of this disease entity by eliminating other possible diagnoses. Nonetheless further studies are needed in order to determine the nature of the acellular amorphous eosinophilic material and to ascertain the immunoprofile of epithelial cells.

Tufted angioma in children: report of two cases and a review of the literature.

Tufted angioma (TA) is a benign vascular tumor with endothelial origin. It is extremely rare in oral mucosa; only seven cases have been reported in the literature so far. Here, we describe two cases of tufted angioma observed in children and we also present a review of the literature about this pathology, concerning the differential diagnosis and management of this lesion in children.

Odontogenic tumors: a 14-year retrospective study in Santa Catarina, Brazil

Odontogenic tumors (OTs) are lesions that develop exclusively on maxillary bones, and form a heterogeneous group. They vary from hamartomatous lesions to benign and malign tumors. Although they are rarely observed in dentistry clinics, it is extremely important for the dentist to be aware of them. The aim of this study was to investigate the incidence of odontogenic tumors diagnosed in the population of Florianópolis, Santa Catarina, Brazil. Cases of odontogenic tumors were selected from the anatomopathological diagnostic services at Federal University of Santa Catarina from 1998 to 2011. Clinical data on these cases were collected from biopsy reports and patient files. Seventy-eight cases of odontogenic tumors were surveyed. Of these diagnoses, 51% were keratocystic odontogenic tumors (KCOTs); the remaining cases were mainly ameloblastomas and odontomas. The most frequently observed lesion in this retrospective study was KCOT (more than half of cases). Thus, this study shows that modifying the classification of the OTs altered the frequency of the lesions, possibly making KCOT the most common lesion observed in diagnostic services worldwide.

Aplicabilidade da técnica de cell block na avaliação citológica do conteúdo de lesões de aspecto cístico dos maxilares / Applicability of cell block technique for cytological evaluation of biological material collected from maxillary cystic lesions

INTRODUÇÃO: A busca por novos métodos que auxiliem e simplifiquem de maneira eficaz o diagnóstico de lesões maxilares, cistos e tumores, objetiva beneficiar os pacientes e facilitar a atuação dos profissionais da área de diagnóstico bucal. Além dos dados clínicos, radiográficos e histopatológicos classicamente utilizados nos protocolos de investigação das lesões maxilares, a adaptação de técnicas já consagradas na medicina pode ser de grande valia. A técnica de cell block se propõe a auxiliar nesse processo, pois consiste na análise citológica de materiais, efusões e líquidos, coletados de lesões passíveis de punção aspirativa, como cistos e tumores císticos dos maxilares. OBJETIVO: Demonstrar a aplicabilidade da técnica de cell block para avaliação citológica de material biológico coletado a partir de lesões císticas dos maxilares. RESULTADOS: Das 20 lesões, das quais o conteúdo foi processado pela técnica, a avaliação citológica de cinco casos de tumores odontogênicos ceratocísticos (TOCs) demonstrou a presença predominante de ceratina, sempre com áreas de paraceratina. Nos demais casos (cinco cistos dentígeros, cinco cistos radiculares e cinco cistos residuais) foi observada a presença de hemácias, células inflamatórias e fendas de cristais de colesterol. CONCLUSÃO: A avaliação citológica, a partir da técnica de cell block, foi útil no estabelecimento do diagnóstico diferencial entre TOC e demais lesões estudadas, cistos radicular, residual e dentígero.

INTRODUCTION: The search for new methods that aid and optimize the diagnosis of cystic and tumoral maxillary lesions aims to benefit both patients and professionals from oral diagnosis. In addition to clinical, radiographic and histological findings traditionally used in research protocol for maxillary lesions, the adaptation of widely used medical techniques may be very helpful. The cell block procedure streamlines this process, inasmuch as it consists of cytopathological analysis of materials, liquids and effusions, collected from aspirated lesions such as maxillary cysts and cystic maxillary tumors. OBJECTIVE: To demonstrate the applicability of cell block technique for cytological assessment of biological material collected from cystic maxillary lesions. RESULTS: The cytological evaluation revealed that five out of 20 lesions, whose content had been processed by this technique, were odontogenic keratocystic tumors (TOCs), predominantly with keratin and always with parakeratin areas. In the other cases (five dentigerous, five radicular and five residual cysts) there were erythrocytes, inflammatory cells, and cholesterol clefts. CONCLUSION: The cytological assessment through cell block technique was useful as to establishing the differential diagnosis between TOC and other lesions, radicular, residual and dentigerous cysts.