14 research outputs found
Estudo citogenetico em bovinos da raca Holandesa preta e branca portadores ou nao do virus da leucose bovina.
Extração de RNA de biópsias de glândula mamária e de células do leite para detectar a expressão de k-caseÃna em bovinos.
Biopolymer-based membranes associated with osteogenic growth peptide for guided bone regeneration
Barrier membranes for guided bone regeneration (GBR) mainly promote mechanical maintenance of bone defect space and induce
osteopromotion. Additionally, biopolymer-based membranes may provide greater bioactivity and biocompatibility due to their similarity to
extracellular matrix (ECM).In this study, biopolymers-based membranes from bacterial cellulose (BC) and collagen (COL) associated with
osteogenic growth peptide (OGP(10–14)) were evaluated to determine in vitro osteoinductive potential in early osteogenesis; moreover, histological
study was performed to evaluate the BC–COL OGP(10–14) membranes on bone healing after GBR in noncritical defects in rat femur. The results
showed that the BC–COL and BC–COL OGP(10–14) membranes promoted cell proliferation and alkaline phosphatase activity in osteoblastic cell
cultures. However, ECMmineralization was similar between cultures grown on BC OGP(10–14) and BC–COL OGP(10–14) membranes. In vivo
results showed that all the membranes tested, including the peptide-free BC membrane, promoted better bone regeneration than control group.
Furthermore, the BC–COL OGP(10–14) membranes induced higher radiographic density in the repaired bone than the other groups at 1, 4 and 16
weeks. Histomorpho-metric analyses revealed that the BC–COL OGP(10–14) induced higher percentage of bone tissue in the repaired area at 2 and 4
weeks than others membranes. In general, these biopolymer-based membranes might be potential candidates for bone regeneration applications
Nanoscale surface modifications of medically-relevant metals: state-of-the art and perspectives
Treatment With a Growth Factor–Protein Mixture Inhibits Formation of Mineralized Nodules in Osteogenic Cell Cultures Grown on Titanium
Despite wide clinical application, the efficacy of platelet-rich plasma (PRP) for repairing bone defects and enhancing osseointegration of metal implants is still subject of debate. This study aimed to evaluate the effects of a well-defined PRP-like mixture containing platelet-derived growth factor-BB, transforming growth factor (TGF)-β1, TGF-β2, albumin, fibronectin, and thrombospondin [growth factors (GFs) + proteins] on the development of the osteogenic phenotype on titanium (Ti) in vitro. Human alveolar bone-derived osteoblastic cells were subcultured on Ti discs and exposed during the first 7 days to osteogenic medium supplemented with GFs + proteins and to osteogenic medium alone thereafter up to 14 days. Control cultures were exposed to only osteogenic medium. Dose–response experiments were carried out using rat primary calvarial cells exposed to GFs + proteins and 1:10 or 1:100 dilutions of the mixture. Treated human-derived cell cultures exhibited a significantly higher number of cycling cells at days 1 and 4 and of total cells at days 4 and 7, significantly reduced alkaline phosphatase (ALP) activity at days 4, 7, and 10, and no Alizarin red–stained areas (calcium deposits) at day 14, indicating an impairment in osteoblast differentiation. Although the 1:10 and 1:100 dilutions of the mixture restored the proliferative activity of rat-derived osteogenic cells to control levels and promoted a significant increase in ALP activity at day 10 compared with GFs + proteins, mineralized nodule formation was only observed with the 1:100 dilution (∼50% of the control). These results showed that a PRP-like protein mixture inhibits development of the osteogenic phenotype in both human and rat osteoblastic cell cultures grown on Ti. (J Histochem Cytochem 57:265–276, 2009
Osteopetrosis Complicated by Osteomyelitis of the Maxilla and Mandible: Light and Electron Microscopic Findings
This report presents a case of osteopetrosis in a 25-year-old male, which was complicated by the development of osteomyelitis in the maxilla and mandible following traumatic injury and tooth extractions. The osteomyelitis in the mandible was refractory to marginal resection and antibiotic therapy. Partial resection with mandible reconstruction was then carried out. Light and backscattered electron scanning microscopy revealed sclerosis of spongy bone and variations in mineral density of the bone matrix. There was also a prominent periosteal bone formation in regions affected by osteomyelitis. An 18-month follow-up showed absence of active infections in the face and oral structures, with a focal area of bone exposure in the right parasymphysis. However, development of anemia and bone marrow deficiency will likely affect prognosis. The importance of preventive oral health care and dental/periodontal managements in osteopetrosis is emphasized