BACKGROUND:Platelet-rich plasma contains high concentrations of growth factors that stimulate proliferation and migration of various cell types. Earlier experiments demonstrated that local ...platelet-rich plasma administration activates Schwann cells to improve axonal regeneration at a transected peripheral nerve lesion. However, the optimal concentration of human platelet-rich plasma for activation of human Schwann cells has not been determined, and mechanisms by which platelet-rich plasma activates Schwann cells remain to be clarified.
METHODS:Human Schwann cells were cultured with various concentrations of platelet-rich plasma in 5% fetal bovine serum/Dulbecco’s Modified Eagle Medium. Cell viability, microchemotaxis, flow cytometry, and quantitative real-time polymerase chain reaction assays were performed to assess proliferation, migration, cell cycle, and neurotrophic factor expression of the human Schwann cells, respectively. Human Schwann cells were co-cultured with neuronal cells to assess their capacity to induce neurite extension. Neutralizing antibodies for platelet-derived growth factor-BB (PDGF-BB) and insulin-like growth factor-1 (IGF-1) were added to the culture to estimate contribution of these cytokines to human Schwann cell stimulation by platelet-rich plasma.
RESULTS:An addition of platelet-rich plasma at 5% strongly elevated proliferation, migration, and neurotrophic factor production of human Schwann cells. Both PDGF-BB and IGF-1 may be involved in mitogenic effect of platelet-rich plasma on human Schwann cells, and PDGF-BB may also play an important role in the migration-inducing effect of platelet-rich plasma. Neutralization of both PDGF-BB and IGF-1 cancelled the promoting effect of platelet-rich plasma on neurite-inducing activity of human Schwann cells.
CONCLUSION:This study may suggest the optimal concentration of platelet-rich plasma for human Schwann cell stimulation and potential mechanisms underlying the activation of human Schwann cells by platelet-rich plasma, which may be quite useful for platelet-rich plasma therapy for peripheral nerve regeneration.
CLINICAL QUESTION/LEVEL OF EVIDENCE:Therapeutic, V.
Abstract Objective To explore the indication and application of computer-assisted navigation in oral and maxillofacial surgery. Patients and methods One hundred and four patients including 34 ...zygomatic-orbital-maxillary fractures, 27 unilateral TMJ ankylosis, 29 craniofacial fibrous dysplasia, 9 mandibular angle hypertrophia, 3 cartilage/bone tumours of jaw and 2 cases with facial foreign bodies were enrolled in this study. CT scans were performed and data was saved in DICOM (digital imaging and communications in medicine) format. The osteotomy lines, amount and range of resection, the reduction position of bony segments and the reconstruction morphology was determined and displayed by preoperative simulation with mirroring and superimposing procedures. All operations were performed under the guidance of navigation system. The accuracy of navigation was evaluated by comparing the postoperative CT 3-D model with preoperative surgical planning. Results Through registration, an accurate match between the intraoperative anatomy and the CT images was achieved. The systematic error checked by computer was within 1 mm. All operations were performed successfully with the guidance of real-time navigation. The mean error between virtual simulation and surgical results was 1.46 ± 0.24 mm. All patients healed uneventfully and function and profile was improved significantly. Conclusions With the opportunity to perform preoperative planning, surgical simulation and postoperative prediction, computer-assisted navigation shows great value in improving the accuracy of maxillofacial surgery, reducing operation risk and postsurgical morbidity, and restoring facial symmetry. It is regarded as a valuable technique in these potentially complicated procedures.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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