RESUMO
Our aim was to compare the osteogenic potential of mononuclear cells harvested from the iliac crest combined with bovine bone mineral (BBM) (experimental group) with that of autogenous cancellous bone alone (control group). We studied bilateral augmentations of the sinus floor in 6 adult sheep. BBM and mononuclear cells (MNC) were mixed and placed into one side and autogenous bone in the other side. Animals were killed after 8 and 16 weeks. Sites of augmentation were analysed radiographically and histologically. The mean (SD) augmentation volume was 3.0 (1.0) cm(3) and 2.7 (0.3) cm(3) after 8 and 16 weeks in the test group, and 2.8 (0.3) cm(3) (8 weeks) and 2.8 (1.2) cm(3) (16 weeks) in the control group, respectively. After 8 weeks, histomorphometric analysis showed 24 (3)% BBM, and 19 (11)% of newly formed bone in the test group. The control group had 20 (13%) of newly formed bone. Specimens after 16 weeks showed 29 (12%) of newly formed bone and 19 (3%) BBM in the test group. The amount of newly formed bone in the control group was 16 (6%). The results show that mononuclear cells, including mesenchymal stem cells, in combination with BBM as the biomaterial, have the potential to form bone.
Assuntos
Aumento do Rebordo Alveolar/métodos , Matriz Óssea/transplante , Substitutos Ósseos/uso terapêutico , Seio Maxilar/cirurgia , Células-Tronco Mesenquimais/fisiologia , Minerais/uso terapêutico , Animais , Matriz Óssea/patologia , Remodelação Óssea/fisiologia , Bovinos , Contagem de Células , Fluoresceínas , Corantes Fluorescentes , Ósteon/patologia , Maxila/patologia , Maxila/cirurgia , Seio Maxilar/patologia , Osteoclastos/patologia , Osteogênese/fisiologia , Ovinos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Transplante Autólogo , Transplante HeterólogoRESUMO
Flavocytochrome P450 BM3 is a bacterial P450 system in which a fatty acid hydroxylase P450 is fused to a mammalian-like diflavin NADPH-P450 reductase in a single polypeptide. The enzyme is soluble (unlike mammalian P450 redox systems) and its fusion arrangement affords it the highest catalytic activity of any P450 mono-oxygenase. This article discusses the fundamental properties of P450 BM3 and how progress with this model P450 has affected our comprehension of P450 systems in general.