Objective To investigate the influence of enamel matrix proteins (EMPs) on the attachment, prol iferation and pre-mRNA of type I collagen synthesis of cultured human dermal fibroblast cells. Methods Human dermal fibroblast cells were obtained from human acrobystia and cultured in DMEM medium with 10% FBS. The 3rd to 6th passage cells were used. Ninety-six-well plates and 6-well plates were pre-coated with different concentrations of EMPs (50, 100, 150 and200 μg/ mL). ① The cell attachment experiment: 0.2 mL cells suspension at the concentration of 1 × 106/mL was added to the pre-coated 96-well plates as the experimental groups (groups A, B, C and D based on different concentrations of EMPs). At 1.5, 3.0, and 4.5 hours after inoculation, the attached cells were measured by MTT method. ② The cell prol iferation experiment: 0.2 mL cells suspension at the concentration of 5 × 104/mL was added to the pre-coated 96-well plates as the experimental groups (groups A1, B1, C1 and D1 based on the different concentrations of EMPs). At 2, 4, 6 and 8 days after inoculation, the cells were measured by MTT method. ③ The synthesis experiment of pre-mRNA: 2 mL cells at the concentration of 1 × 106/mL was added to the pre-coated 6-well plates as the experimental groups (groups A2, B2, C2 and D2 based on different concentrations of EMPs). At 5 days after inoculation, the synthesis of pre-mRNA was measured by RT-PCR method. Human dermal fibroblast cells were added to the un-coated plates as the control groups. Results ① The cell attachment experiment: There were significant differences in attachment cells between the control group, group A and the groups B, C and D (P lt; 0.05). There were no significant difference between group A and control group (P lt; 0.05). ② The cell prol iferation experiment: At 2 days, there were no significant differences in absorbance between the control group and the experimental groups (P gt; 0.05); at 4 days and 6 days, the absorbance of groups B1 (0.598 ± 0.020 and 0.639 ± 0.016 ), C1 (0.582 ± 0.017 and 0.641 ± 0.020) and D1 (0.574 ± 0.021and 0.635 ± 0.021) was significantly higher than that of the control group (0.548 ± 0.021 and 0.605 ± 0.019, P lt; 0.05); at 8 days, the absorbance of group B1 (0.629 ± 0.012) and group C1 (0.631 ± 0.014) was significantly higher than that of the control group (0.606 ± 0.031, P lt; 0.05). ③ The synthesis experiment of pre-mRNA: The synthesis of type I collage pre-mRNA of groups B2, C2 and D2 was significantly higher than that of the control group. Conclusion EMPs stimulate human dermal fibroblast cell attachment, prol iferation and synthesis of type I collage pre-mRNA, and its maximal effect can be achieved at the concentration of 100 μg /mL.
ObjectiveTo investigate the clinical results and complication prevention of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of single-segment severe lumbar spinal stenosis (LSS).MethodsThe clinical data of 112 patients with severe LSS treated with MIS-TLIF between January 2010 and January 2017 were retrospectively analyzed. There were 43 males and 69 females, aged 52-81 years, with an average age of 65.3 years. The disease duration ranged from 4 to 126 months, with an average of 10.5 months. Clinical manifestations: 104 cases of low back pain, 91 cases of nervous intermittent claudication of both lower limbs, 21 cases of unilateral nerve root pain and/or numbness, and 5 cases of cauda equina nerve injury. The 112 cases were all severe central spinal stenosis, including 32 cases with lateral recess stenosis, 20 cases with foramen stenosis, 9 cases with ossification of ligamentum flavum, 38 cases with disc herniation; 14 cases with two complications and 5 cases with three. Stenosis segment: L3, 4 in 6 cases, L4, 5 in 89 cases, and L5, S1 in 17 cases. Surgical methods included bilateral decompression through bilateral approach (60 cases), bilateral decompression through unilateral approach (15 cases), and unilateral decompression (37 cases). The operation time, intraoperative blood loss, visual analogue scale (VAS) score of low back pain and leg pain, Oswestry disability index (ODI) score, fusion rate, and surgical complications were recorded. At last follow-up, the lumbar fusion was evaluated by Bridwell method, grades Ⅰ and Ⅱ were expressed as fusion.ResultsThe operation time was 83-186 minutes (mean, 126.8 minutes), and the intraoperative blood loss was 65-630 mL (mean, 163.1 mL). All the 112 patients were followed up 25-49 months, with an average of 35.1 months. The VAS score of low back pain and leg pain and ODI score at each time point after operation were significantly improved when compared with preoperative scores (P<0.05). There was no significant difference between the VAS score of low back pain and leg pain and ODI score at the other time points except 1 month after operation (P<0.05). At last follow-up, 2 cases of cauda equina nerve injury recovered and 3 cases partially recovered. According to Bridwell classification criteria, 58 cases were grade Ⅰ, 47 cases were grade Ⅱ, and 7 cases were grade Ⅲ. The fusion rate was 93.8%. Perioperative complications included 5 cases of incision complications (superficial infection in 3 cases, hematoma formation in 2 cases), 19 cases of internal fixator complications (intraoperative end plate fracture in 8 cases, fusion cage sinking in 11 cases at last follow-up), and 15 cases of neurological complications (dural sac tear in 10 cases, transient neurological symptoms of lower extremities aggravated in 5 cases). Conclusion MIS-TLIF treatment of single-level severe LSS can achieve good clinical results, while there is a risk of serious complications. Full understanding of the clinical and imaging features of the disease and reasonable and careful operation are helpful to control the occurrence of cauda equina nerve damage.