ObjectiveTo explore the clinical application and effectiveness of antibiotic-loaded cement spacer combined with free fibular graft in the staged treatment of infectious long bone defect in the lower extremity. MethodsA retrospective analysis was made on the clinical data from 12 patients with infectious long bone defect in the lower extremity between June 2010 and June 2012. Of the 12 cases, there were 9 males and 3 females with an average age of 33 years (range, 19-46 years), including 3 cases of femoral shaft bone defect, 7 cases of tibial shaft bone defect, and 2 cases of metatarsal bone defect. The causes were traffic accident injury in 7 cases, crashing injury in 3 cases, and machine extrusion injury in 2 cases. The length of bone defect ranged from 6 to 14 cm (mean, 8 cm). The soft tissue defect area ranged from 5.0 cm×3.0 cm to 8.0 cm×4.0 cm companied with tibial shaft and metatarsal bone defect in 9 cases. The sinus formed in 3 femoral shaft bone defects. The time between injury and operation was 1-4 months (mean, 2 months). At first stage, antibiotic-loaded cement spacer was placed in the bone defect after debridement and the flaps were used to repair soft tissue defect in 9 cases; at second stage (6 weeks after the first stage), defect was repaired with free fibular graft (7-22 cm in length, 14 cm on average) after antibiotic-loaded cement spacer removal. The area of the cutaneous fibular flap ranged from 6.0 cm×4.0 cm to 10.0 cm×5.0 cm in 10 cases. ResultsAll wounds healed by first intention, and the healing time was 12-18 days, 14 days on average. Twelve cases were followed up 12-36 months (mean, 17 months). Bone healing time ranged from 4 to 6 months (5.5 months on average). The cutaneous fibular flap had good appearance. The function at donor site was satisfactory; no dysfunction of the ankle joint or tibial stress fracture occurred after operation. The mean Enneking score was 25 (range, 20-28) at last follow-up. ConclusionInfection can be well controlled with the antibiotic-loaded cement spacer during first stage operation, and free fibular graft can increase the bone defect healing rate at second stage. Staged treatment is an optimal choice to treat infectious long bone defect in the lower extremity.
ObjectiveTo observe the effect of lentivirus-mediated cyclooxygenase 2 (COX-2) and Aggrecanase-1 silencing and insulin-like growth factor 1 (IGF-1) in BMSCs after injecting into the knee joint cavity in cynomolgus monkeys with knee osteoarthritis (OA). MethodsBMSCs were isolated from the bone marrow of 10 donors. The lentivirus vector expressing genes of COX-2, Aggrecanase-1, and IGF-1 were constructed, and transfected into the third generation human BMSCs at 40 multiplicity of infection (virus group); BMSCs transfected with lentivirus-empty vector served as blank-virus group. The growth status and number of BMSCs were observed under inverted phase contrast microscope, and normal BMSCs were used as normal control group. At 1 week after transfected, the mRNA expressions of COX-2, Aggrecanase-1, and IGF-1 were detected with RT-PCR. Nine 3-year-old cynomolgus monkeys were selected to establish the OA model according to Hulth modeling method, and were randomly divided into 3 groups (n=3). At 6 weeks after remodeling, the right knee joint cavity was injected accordingly with 1 mL BMSCs (about 1×107 cells) in virus group and blank-virus group, with 1 mL of normal saline in the blank control group; the left knee served as normal controls. The general condition was observed after injection; at 1, 4, and 6 weeks, the concentrations of prostaglandin E2 (PGE2), IL-1, Aggrecanase-1, and IGF-1 of double knee liquid were detected with ELISA; at 6 weeks, MRI, general observation, histology method, and immunohistochemistry method were used to detect the knee cartilage changes and the expressions of COX-2, Aggrecanase-1, and IGF-1 were measured with RT-PCR. ResultsNo significant difference was found in cell morphology and growth curve between 2 groups after transfection. By RT-PCR, COX-2, and Aggrecanase-1 expressions were significantly reduced, IGF-1 expression was significantly increased in virus group when compared with normal control group and the blank-virus group (P < 0.05). All monkeys survived to the end of the experiment after injection. When compared with blank-virus group and blank control group, the concentrations of PGE2, Aggrecanase-1, and IL-1 significantly decreased and the concentration of IGF-1 significantly increased in the virus group (P < 0.05), but the indicators in 3 groups were significantly higher than those in the normal control group (P < 0.05). MRI showed that abnormal articular surface with high density could be found in virus group, blank-virus group, and blank control group, while the virus group had the minimum area. Gross observation and histological observation showed that the cartilage morphology of virus group, blank-virus group, and blank control group was accordance with early OA articular cartilage changes, but virus group was better than blank-virus group and blank control group in repair degree, whose improved Pineda score was significantly lower (P < 0.05). Immunohistochemical staining showed that the virus group had deeper dyeing with occasional brown particles and more chondrocytes than blank-virus group and blank control group. By RT-PCR, COX-2 and Aggrecanase-1 mRNA expressions of cartilage in virus group were significantly decreased, and IGF-1 expression was significantly increased when compared with blank control group and the blank-virus group (P < 0.05). ConclusionLentivirus-mediated multi-genes co-transfection in BMSCs can inhibit the expressions of COX-2 mRNA and Aggrecanase-1 mRNA, and enhance the IGF-1 mRNA expression, which decreases the concentration of inflammatory factors, and protects the joint cartilage effectively.
The real-time monitoring of cerebral hemorrhage can reduce its disability and fatality rates greatly. On the basis of magnetic induction phase shift, we in this study used filter and amplifier hardware module, NI-PXI data-acquisition system and LabVIEW software to set up an experiment system. We used Band-pass sample method and correlation phase demodulation algorithm in the system. In order to test and evaluate the performance of the system, we carried out saline simulation experiments of brain hemorrhage. We also carried out rabbit cerebral hemorrhage experiments. The results of both saline simulation and animal experiments suggested that our monitoring system had a high phase detection precision, and it needed only about 0.030 4s to finish a single phase shift measurement, and the change of phase shift was directly proportional to the volume of saline or blood. The experimental results were consistent with theory. As a result, this system has the ability of real-time monitoring the progression of cerebral hemorrhage precisely, with many distinguished features, such as low cost, high phase detection precision, high sensitivity of response so that it has showed a good application prospect.