RESUMO
The mechanisms of secondary brain injury after traumatic brain injury (TBI) are complex and are the result of multiple factors. Protecting the blood-brain barrier (BBB) and ameliorating cerebral edema are two key factors for improving the prognosis of TBI patients. The BBB is regulated by the hedgehog pathway through Scube2 and Shh protein. Matrix metalloproteinase-9 (MMP-9) influences the transport system and enzyme system of vascular endothelial cells, possibly via the hedgehog pathway. The present study aimed to investigate the role and mechanism of MMP-9 in TBI via the hedgehog pathway. Eighty male Sprague-Dawley rats were used to establish a murine model of TBI. Subsequently, the effect of SB-3CT-a specific inhibitor of MMP-9-was assessed via Western blotting, real-time PCR, immunofluorescence, apoptotic assays, and neurological scoring. The results showed that, compared with those of the sham-operation group, the mRNA and protein levels of MMP-9 were significantly increased after TBI, while the expressions of Scube2 and Shh were decreased. Application of SB-3CT at 24 h after TBI significantly reduced neuronal apoptosis and BBB permeability, while increasing expressions of Scube2 and Shh. In conclusion, these findings demonstrate an influence of TBI-induced MMP-9 upregulation in the induction of post-traumatic nerve and BBB injury, which may be partially mediated by Scube2 and Shh via the hedgehog pathway.
Assuntos
Barreira Hematoencefálica/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Encéfalo/metabolismo , Proteínas Hedgehog/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Compostos Heterocíclicos com 1 Anel/administração & dosagem , Masculino , Inibidores de Metaloproteinases de Matriz/administração & dosagem , RNA Mensageiro , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Sulfonas/administração & dosagemRESUMO
BACKGROUND: Local antibiotic therapy has gained increasing attraction in the prevention and treatment of fracture infection. However, no reports have used local antibiotic therapy in the management of early infection after fracture fixation with retention of implants. METHODS: The present surgical technique report the use of antibiotic impregnated bone cement in the management of early infection after fracture fixation. Initially, the fractures were fixed with plates. The average time from initial procedure to debridement was15 days (range 9 to 25 days). The infections were treated with irrigation, debridement, and retention of the implant. The lateral surface of the plates was coated with antibiotic cement and the bone defect was filled with antibiotic cement spacer after thorough debridement. RESULTS: Ten patients underwent this technique. The mean follow-up was 2.0 years (range 6 months to 4 years). The bone union rate was 100%, and the average time to bone healing was5.5 months.There was recurrence of infection in one patient before bone healing, but the implants were left in place until bone healed, and the infection was eradicated after implant removal. CONCLUSION: Coating the plate with antibiotic cement is a simple technique which may play a role in the management of early infection after fracture fixation.
