BACKGROUND: Secretion of various neurotrophic factors by Schwann cells plays important roles in neural regeneration. However, the secretion capability is affected by many factors. To seek a feasible method for promoting nerve growth factor secretion by Schwann cells is a key of regeneraion following neurologic defect.OBJECTIVE: To explore the effects of methylprednisolone(solu-medrol) on the secreted function of Schwann cells of cultured rats.METHODS: Schwann cells were isolated and cultured by enzyme digestion method. Cell growth was observed under an inverted phase contrast microscope. Following passage, purity of some Schwann cells was identified using S-100 protein immunity. Other Schwann cells were regulated using cell counting plate into 1×10~9/L, and incubated in a 6-well culture plate (15 wells) for further incubation. Following 4 days of culture, different concentrations of solu-medrol (10~(-3), 10~(-4), 10~(-6), 10~(-8) mol/L) were administrated to the cell, while blank control group (1 well) was given no drug. 24, 48 and 72 hours after administration, reverse trancription-polymerase chain reaction (RT-PCR) was used in the detection of the levels of nerve growth factor mRNA.RESULTS AND CONCLUSION: Number of primarily cultured cells was significantly increased at day 7, and 80% cells were confluent. Subcultured cells were spindle-shaped, with 2 thin long processes, showing positive fluorescence staining. Fibroblasts were round or flat, showing negative reaction of fluorescence staining. Reserve transcription-polymerase chain reaction demonstrated that nerve growth factor number at 72 hours affected by 10~(-8) mol/L radiosone was increased compared with the blank control group and other concentrations and other time points (P < 0.05). Number of nerve growth factor was reduced following treatment of 10~(-3) mol/L radiosone compared with the blank control group and other concentrations (P < 0.05). These results suggested that high concentration of solu-medrol prohibits secreted function of Schwann's cells, but long time and low dosage solu-medrol promotes secreted function of Schwann's cells.

In this study we calculate theoretically and use FEM to simulate the effect of plate position relative to bending direction on the overall bending stiffness of the composite system plate-bone. The results show that for different bending directions the effect of the modulus of elasticity of the plate is negligible. Changing the position of a plate will often alter the stress obviously. During the operation, the steel plate should be assigned onto the tension side of the bone.
Bone Plates ; Finite Element Analysis ; Fracture Fixation, Internal ; methods ; Models, Biological ; Stainless Steel ; Stress, Mechanical ; Tensile Strength