RESUMO
AIM: To assess the shaping ability of the new XP-endo Shaper instrument after different working times. METHODOLOGY: Ten mesial roots of mandibular molars were scanned in a micro-computed tomographic device and prepared using the XP-endo Shaper instrument up to the working length (WL) according to the manufacturer's recommendation. Then, each specimen was subjected to an extra 15, 30 and 45 s of active instrumentation at the WL. Postoperative scans were performed after canal preparation at each time-point. Then, the registered pre- and postoperative datasets were examined to evaluate the percentages of volume and surface area of the instrumented canal, surface area of noninstrumented canal areas and the volume of removed dentine. Repeated measures general linear model was used to compare the differences in either the increase or the reduction of the parameters amongst the time-points. Alpha-error was set at 5%. RESULTS: Extending the period of XP-endo Shaper active instrumentation at WL significantly influenced several parameters such as volume (P < 0.001) and surface area (P < 0.001) of the instrumented canal, surface area of noninstrumented canal areas (P < 0.001), and volume of removed dentine (P < 0.001). CONCLUSIONS: Extending the activation time of XP-endo Shaper instruments at WL resulted in a more comprehensive root canal preparation, increasing the volume and surface area of root canal preparation and the volume of removed dentine.
Assuntos
Instrumentos Odontológicos , Dente Molar/cirurgia , Preparo de Canal Radicular/instrumentação , Desenho de Equipamento , Humanos , Técnicas In Vitro , Dente Molar/diagnóstico por imagem , Microtomografia por Raio-XRESUMO
A circadian rhythm in the activity of nitrate reductase (NR; EC 1.6.6.1) isolated from the marine dinoflagellate Gonyaulax polyedra is shown to be attributable to the daily synthesis and destruction of the protein. The enzyme was purified in three steps: gel filtration on S-300 Sephacryl, an Affigel-Blue column, and a diethylaminoethyl ion-exchange column. Undenatured protein shows a molecular mass of about 310 kD; based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the enzyme appears to be composed of six possibly identical subunits. The amino acid composition of the G. polyedra NR is very similar to that reported for the NR of barley leaves, Chlorella vulgaris, and Ankistrodesmus braunii. The experiments reported indicate that the cellular expression of NR is under circadian control. In extracts of cells grown under either constant dim light or a light-dark cycle, the activity of NR exhibits a daily rhythm, peaking at midday phase, as does photosynthesis. Staining with affinity-purified polyclonal antibodies, raised in rabbits against purified NR, shows that the amount of protein changes by a factor of about 10, with the maximum occurring in midday phase.
Assuntos
Ritmo Circadiano , Dinoflagellida/enzimologia , Nitrato Redutases/metabolismo , Aminoácidos/análise , Animais , Anticorpos/farmacologia , Dinoflagellida/fisiologia , Nitrato Redutase , Nitrato Redutases/antagonistas & inibidores , Nitrato Redutases/química , Nitrato Redutases/isolamento & purificação , Proteínas/metabolismo , CoelhosRESUMO
Relata-se um caso de Histiocitose Sinusal com Linfadenopatia Maciça (SH ML) diagnosticado em criança de 8 anos. Depois de apresentados aspectos clínicos, säo comentados os resultados de exames laboratoriais e radiográficos, os quais complementam a fundamentaçäo do diagnóstico, que se baseou principalmente na histologia de linfonodos cervical. O processo regrediu paulatinamente e resultou em cura espontânea