RESUMEN
We here describe the use of a continuous Percoll density gradient in preparing a fraction of consistently more than 95% rat somatotrophs. Recovery was about 50% and cell viability 98-99.5%. Two groups of somatotrophs were identified, one (74-82%, type II) heavily and another (18-26%, type I) sparsely granulated. Freshly prepared somatotrophs responded to growth hormone-releasing factor but the responsiveness was greatly enhanced after 3 days' culture. Electron microscopy revealed a well-preserved morphological integrity in both freshly prepared and cultured somatotrophs. culture reduced the average granule profile area and granule volume density of type II cells. This population of pure and well-functioning somatotrophs is suited for studies on the cellular mechanisms involved in growth hormone secretion.
Asunto(s)
Adenohipófisis/citología , Animales , Separación Celular/métodos , Células Cultivadas , Centrifugación por Gradiente de Densidad , Hormona del Crecimiento/análisis , Hormona del Crecimiento/metabolismo , Hormona Liberadora de Hormona del Crecimiento/fisiología , Masculino , Adenohipófisis/análisis , Adenohipófisis/fisiología , Adenohipófisis/ultraestructura , Povidona , Ratas , Ratas Endogámicas , Dióxido de SilicioRESUMEN
OBJECTIVE: Surgical management is intended to eliminate or block infection originating in the root canals. The root end is customarily sealed to prevent pathogenic products remaining in the root canal from reaching the periradicular tissues. The purpose of this study was to evaluate the microbiologic and radiographic outcomes of surgical treatment of periradicular pathosis associated with teeth with necrotic pulps. STUDY DESIGN: One tooth from each of 10 patients was root-end resected and root-end filled without prior root canal treatment. One year postoperatively, the outcomes were assessed radiographically and the root canals were sampled for bacteria. RESULTS: Radiographic examination showed complete or incomplete (scar tissue) healing in 5 teeth and uncertain healing in the other 5 teeth. Bacteriologic samples from the root canals were positive in 9 of the 10 cases. CONCLUSIONS: In teeth with necrotic pulps, treatment of periradicular pathosis by surgery and root-end filling may show radiographic evidence of satisfactory healing 1 year postoperatively. However, viable bacteria may persist in the canals, constituting a potential risk factor for recurrence of periradicular pathosis.