Evaluation of Guided Bone Regeneration in Critical Defects Using Bovine and Porcine Collagen Membranes: Histomorphometric and Immunohistochemical Analyses.

Guided bone regeneration (GBR) is a technique used to facilitate bone regeneration, which uses a biocompatible membrane acting as a physical barrier to prevent the adjacent connective tissue from invading the bone defect. The aim of this study was to evaluate and compare the effectiveness of bovine and porcine collagenous membranes as barriers to connective tissue invasion during the repair of critical bone defects in rat calvaria, using histological, histometric, and immunohistochemical analyses. For this study, 72 rats were divided into three groups: clot group (CG), bovine collagen group (BCG), and porcine collagen group (PCG). Analyses were performed on days 7, 15, 30, and 60. The histological results showed that the PCG exhibited bone neoformation starting from day 7, and after 30 days of repair, the surgical defect was completely filled in some animals. For the BCG, there was little bone neoformation activity in the initial periods, and from day 30 onwards, there was an increase in bone neoformation, with a greater increase on day 60. The data obtained in the histometric analysis reveal that, on day 30, the neoformed bone area did not vary greatly between the PCG and the BCG, though both varied from the CG. By day 60, the PCG presented a greater area of neoformation than the BCG. These results were corroborated by the immunohistochemistry results. In view of the results obtained, it can be concluded that all membranes studied in this research promoted GBR.

Adenoma de paratireóide em caso de hiperparatireoidismo primário no idoso: relato caso / Parathyroid adenoma in primary hyperparathyroidism in the elderly: case report

O hiperparatireoidismo primario é um distúrbio comum do metabolismo ósseo, envolvendo os íons e fósforo, causado pelo aumento nos níveis circulantes de paratormônio. Sua principal causa é o adenoma de paratireóide, representando 80-85% dos casos. Relato de caso de uma paciente idosa com adenoma de paratireóide, e revisão da literatura onde são abordados os atuais critérios diagnósticos e de indicação cirúrgica para o hiperparatireoidismo primário. O diagnóstico de hiperparatireoidismo primário deve ser lembrado em todo paciente com osteoporose severa ou naqueles que se apresentam com fraturas espontâneas ou após trauma mínimo (trauma igual ou menor que o equivalente a uma queda do próprio nível). Para pacientes idosos assintomáticos, sem perda de função renal ou de massa óssea significativa, pode ser indicado apenas o manejo ambulatorial. Entretanto, quando indicado, o tratamento cirúrgico – através da remoção do tecido paratireóideo hiperfuncionante – ainda é o padrão.