Prenatal alcohol exposure reduces mandibular calcium and phosphorus concentrations in newborn rats.

Previous studies suggest that prenatal alcohol exposure affects fetal bone development, including bone quality. This study evaluated the chemical composition of mandibles from newborn rats after maternal 20% alcohol consumption before and throughout gestation. Nine rats were initially distributed into three groups: an Alcohol group, Pair-fed group, and Control group. The groups were fed prespecified diets for 8 weeks before and the 3 weeks during pregnancy. At age 5 days, eight newborns from each group were euthanized (total, n = 24). Using energy dispersive spectrometry, we evaluated samples of mandibles from newborns to identify changes in bone mineralization, specifically Ca and P concentrations. Ca and P concentrations were lower in the Alcohol group than in the Control and Pair-fed groups (P = 0.003 and P = 0.001, respectively). In summary, alcohol exposure before and throughout gestation reduces mandibular Ca and P concentrations in newborn rats. (J Oral Sci 58, 439-444, 2016).

Periodontal response to subgingival restorations in dogs with periodontitis.

The aim of this study was to evaluate the periodontal response to subgingival restorations in dogs with naturally occurring periodontitis. At the baseline, the experimental teeth from three dogs (2nd and 3rd upper premolars and 2nd, 3rd and 4th lower premolars) were randomly assigned to Resin-modified Glass Ionomer Cement (RMGIC) and Amalgam (AM) restorations or controls (CT) at the buccal sites with (SUPRA+) or without mechanical supragingival plaque control (SUPRA) and maintained for 90 days. Clinical [Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), and Gingival Margin Recession (GMR)], histological (connective tissue inflammatory and epithelium condition) and histometric evaluation (distance between the apical border of the cavity and the bone level and between the apical extension of the epithelium and the bone level) were performed by a calibrated blinded examiner. Better clinical (especially regarding CAL) and histological results (unaltered epithelium and less severe inflammatory connective tissue) were observed associated with RMGIC sites. Histometric evaluation showed less bone loss associated to RMGIC. Overall, SUPRA+ sites presented less inflammatory response. It could be concluded that in dogs with periodontitis, subgingival RMGIC restorations, especially in the presence of supragingival plaque control, elicited better periodontal response than AM restorations.

Periodontal response to subgingival restorations in dogs with periodontitis

The aim of this study was to evaluate the periodontal response to subgingival restorations in dogs with naturally occurring periodontitis. At the baseline, the experimental teeth from three dogs (2nd and 3rd upper premolars and 2nd, 3rd and 4th lower premolars) were randomly assigned to Resin-modified Glass Ionomer Cement (RMGIC) and Amalgam (AM) restorations or controls (CT) at the buccal sites with (SUPRA+) or without mechanical supragingival plaque control (SUPRA-) and maintained for 90 days. Clinical [Periodontal Probing Depth (PPD), Clinical Attachment Loss (CAL), and Gingival Margin Recession (GMR)], histological (connective tissue inflammatory and epithelium condition) and histometric evaluation (distance between the apical border of the cavity and the bone level and between the apical extension of the epithelium and the bone level) were performed by a calibrated blinded examiner. Better clinical (especially regarding CAL) and histological results (unaltered epithelium and less severe inflammatory connective tissue) were observed associated with RMGIC sites. Histometric evaluation showed less bone loss associated to RMGIC. Overall, SUPRA+ sites presented less inflammatory response. It could be concluded that in dogs with periodontitis, subgingival RMGIC restorations, especially in the presence of supragingival plaque control, elicited better periodontal response than AM restorations.

O objetivo do presente estudo foi avaliar a resposta do periodonto a restaurações subgengivais em cães com diagnóstico de periodontite. No início do estudo, os dentes experimentais de três cães (2o e 3o molares superiores e 2o, 3o e 4o premolares inferiores) foram randomicamente designados para restauração com cimento de ionômero de vidro modificado por resina (CIVMR), amálgama (AM) ou Controle (CT) nos sítios vestibulares submetidos (SUPRA+) ou não (SUPRA-) a controle mecânico de placa supragengival e mantidos por 90 dias. Avaliações clínicas [Profundidade de Sondagem (PS), Nível de Inserção Clínica (NIC), Recessão Gengival (RG)], histológicas (condições inflamatórias do tecido epitelial e conjuntivo) e histométricas (distância entre a margem apical da cavidade e o nível ósseo e entre a extensão apical do epitélio e o nível ósseo) foram realizadas por examinador calibrado e cego. Melhores resultados clínicos (especialmente quanto à PI) e histológicos (epitélio sem alterações e tecido conjuntivo com menor severidade de infiltrado inflamatório) foram observados em associação a sítios restaurados com CIVMR. A avaliação histométrica mostrou menor perda óssea associada a restauração com CIVMR. Todos os sítios SUPRA+ exibiram menor resposta inflamatória. Pode ser concluído que, em cães com periodontite, restaurações subgengivais realizadas com CIVMR, especialmente na presença de controle mecânico de placa supragengival, apresentaram melhor resposta do periodonto quando comparadas com restaurações de amálgama.

Avaliação da superexpressão da proteína p53 e das mutações no éxon 8 do gene TP53 em carcinomas mamários caninos e glândulas normais / Evaluation of immunohistochemical over expression of p53 protein and of mutations in exon 8 of Tp53 gene in canine mammary carcinomas and normal mammary glands

This study was undertaken with the aim to evaluate the p53 expression, applying the immunohistochemical technique to malignant primary mammary neoplasms histopathologically diagnosed in female dogs, and to investigate exon 8 of the Tp53 suppressor gene for mutation types by means of PCR-RFLP pattern of bands. Nineteen healthy mammary glands were used as a control group (group 1). Samples from 18 cases diagnosed with malignant mammary tumors (group 2), and the contralateral mammary glands (group 3) were collected during the UFRPE Veterinary Hospital routine. The tumors were diagnosed by histopathology and subdivided into grades of malignity. The streptavidin-biotin peroxidase method was used to analyze the immunohistochemical expression of p53, evaluated according to the location and intensity of stain. Expression of p53 protein was not observed in the samples of group 1. On the contrary, it was observed in all malignant tumors; the protein p53 was localized either only in the nucleus or in the nucleus and in the cytoplasm, in samples of group 2. In group 3, expression of p53 protein was observed in the tumors (2 samples) and in normal mammary tissues (4 samples). For the molecular analyses, genomic DNA was extracted and submitted to PCR-RFLP with the following endonuclease enzymes: AluI, BsoBI, DdeI and SmaI. The band pattern showed polymorphism between groups, but not between histological variants of tumors. This polymorphism detected mutations in the fragment studied - exon 8 of Tp53 - which could account for changes in nucleotides, located in the restriction sites of the endonuclease enzymes. In conclusion, the immunoexpression of p53 had no relationship with histological subtype or malignity grade, but it can be related to the presence of mammary tumors in female dogs. The PCR-RFLP technique can be an important tool for the study of mammary carcinogenesis in bitches because the polymorphism obtained may allow early diagnosis in tissues of mammary glands.

Este estudo foi realizado com o objetivo de avaliar a expressão da proteína p53, pela técnica de imuno-histoquímica, em neoplasmas mamários malignos em cadelas, além de investigar mutações no éxon 8 do gene supressor Tp53 por meio do padrão de bandas obtidas por PCR-RFLP. Dezenove mamas de cadelas saudáveis foram usadas como controle (Grupo 1). Amostras de 18 casos de tumores malignos (Grupo 2) e suas glândulas mamárias contralaterais (Grupo 3) foram obtidas na rotina do Hospital Veterinário da UFRPE. Os tumores foram identificados histologicamente e classificados em graus de malignidade. O método da estreptoavidina-biotina peroxidase foi utilizado para a análise da expressão de p53 por imuno-histoquímica, de acordo com a localização e intensidade da coloração. A expressão da proteína p53 não foi observada nas amostras do Grupo 1, mas foi encontrada em todas as amostras de tumores malignos (Grupo 2) seja só no núcleo, ou também no citoplasma. No Grupo 3, a expressão foi observada em quatro amostras normais e em duas que apresentavam tumor. Para a análise molecular, o DNA genômico foi extraído e submetido à PCR-RFLP com as seguintes endonucleases: AluI, BsoBI, DdeI e SmaI. O padrão de bandas foi polimórfico entre os grupos, mas não entre as variantes tumorais. Esse polimorfismo detectou mutações no fragmento estudado - éxon 8 do gene Tp53 - que podem resultar em alterações nos nucleotídeos, localizados nos sítios de restrição das enzimas. Esses achados levam a conclusão de que a imunoexpressão da p53 não tem relação com o subtipo histológico ou grau de malignidade do tumor, mas sim com a presença dos tumores no tecido mamário de cadelas. A PCR-RFLP pode ser usada como importante ferramenta para o estudo da carcinogênese mamária na cadela, possibilitando gerar diagnósticos precoces através do polimorfismo obtido com endonucleases de restrição pré-selecionadas.