Objective To investigate the risk factors for ligamentum flavum hypertrophy(LFH)and its correlation with clinical symptoms in patients with degenerative lumbar spinal stenosis(DLSS).Methods The clinical and imaging data of 79 patients with DLSS were collected.Patients were divided into four groups based on LFH severity.Quantitative parameters,including lumbar lordosis(LL),sacral slope(SS),facet tropism,facet joint effusion,intervertebral height index,dural sac cross-sectional area(CSA),epidural fat area,and fat infiltration rate(FIR)of the paraspinal muscle were measured on imaging.One-way analysis of variance was used to compare the differences in these parameters among groups.Multiple linear regression analysis was performed to identify the risk fac-tors for LFH,and the correlation between LFH severity and clinical manifestations was analyzed.Results The results of one-way analy-sis of variance showed that there were statistically significant differences among the four groups of patients in terms of sex,body mass index(BMI),LL,epidural fat area and FIR of the multifidus(MF).Multiple linear regression analysis identified that BMI,LL,and epidural fat area as independent risk factors for LFH.Correlation analysis indicated a weak positive association between LFH and dis-ease duration(r=-0.231,P=0.041).Conclusion In DLSS patients,LFH is weakly correlated with disease duration,while BMI,LL,and epidural fat area are risk factors for LFH.

Objective To investigate the risk factors for ligamentum flavum hypertrophy(LFH)and its correlation with clinical symptoms in patients with degenerative lumbar spinal stenosis(DLSS).Methods The clinical and imaging data of 79 patients with DLSS were collected.Patients were divided into four groups based on LFH severity.Quantitative parameters,including lumbar lordosis(LL),sacral slope(SS),facet tropism,facet joint effusion,intervertebral height index,dural sac cross-sectional area(CSA),epidural fat area,and fat infiltration rate(FIR)of the paraspinal muscle were measured on imaging.One-way analysis of variance was used to compare the differences in these parameters among groups.Multiple linear regression analysis was performed to identify the risk fac-tors for LFH,and the correlation between LFH severity and clinical manifestations was analyzed.Results The results of one-way analy-sis of variance showed that there were statistically significant differences among the four groups of patients in terms of sex,body mass index(BMI),LL,epidural fat area and FIR of the multifidus(MF).Multiple linear regression analysis identified that BMI,LL,and epidural fat area as independent risk factors for LFH.Correlation analysis indicated a weak positive association between LFH and dis-ease duration(r=-0.231,P=0.041).Conclusion In DLSS patients,LFH is weakly correlated with disease duration,while BMI,LL,and epidural fat area are risk factors for LFH.

Objective To investigate the potential value of exosomes derived from rat ectoderm mesenchymal stem cells(EMSCs-exo)for repairing secondary spinal cord injury.Methods EMSCs-exo were obtained using ultracentrifugation from EMSCs isolated from rat nasal mucosa,identified by transmission electron microscope,nanoparticle tracking analysis(NTA),and Western blotting,and quantified using the BCA method.Neonatal rat microglia purified by differential attachment were induced with 100 μg/L lipopolysaccharide(LPS)and treated with 37.5 or 75 mg/L EMSCs-exo.PC12 cells were exposed to 400 μmol/L H2O2 and treated with EMSCs-exo at 37.5 or 75 mg/L.The protein and mRNA expressions of Arg1 and iNOS in the treated cells were determined with Western blotting and qRT-PCR,and the concentrations of IL-6,IL-10,and IGF-1 in the supernatants were measured with ELISA.The viability and apoptosis of PC12 cells were detected using CCK-8 assay and flow cytometry.Results The isolated rat EMSCs showed high expressions of nestin,CD44,CD105,and vimentin.The obtained EMSCs-exo had a typical cup-shaped structure under transmission electron microscope with an average particle size of 142 nm and positivity for CD63,CD81,and TSG101 but not vimentin.In LPS-treated microglia,EMSCs-exo treatment at 75 mg/L significantly increased Arg1 protein level and lowered iNOS protein expression(P<0.05).EMSCs-exo treatment at 75 mg/L,as compared with the lower concentration at 37.5 mg/L,more strongly increased Arg1 mRNA expression and IGF-1 and IL-10 production and decreased iNOS mRNA expression and IL-6 production in LPS-induced microglia,and more effectively promoted cell survival and decreased apoptosis rate of H2O2-induced PC12 cells(P<0.05).Conclusion EMSCs-exo at 75 mg/L can effectively reduce the proportion of M1 microglia and alleviate neuronal apoptosis under oxidative stress to promote neuronal survival,suggesting its potential in controlling secondary spinal cord injury.

Objective To investigate the potential value of exosomes derived from rat ectoderm mesenchymal stem cells(EMSCs-exo)for repairing secondary spinal cord injury.Methods EMSCs-exo were obtained using ultracentrifugation from EMSCs isolated from rat nasal mucosa,identified by transmission electron microscope,nanoparticle tracking analysis(NTA),and Western blotting,and quantified using the BCA method.Neonatal rat microglia purified by differential attachment were induced with 100 μg/L lipopolysaccharide(LPS)and treated with 37.5 or 75 mg/L EMSCs-exo.PC12 cells were exposed to 400 μmol/L H2O2 and treated with EMSCs-exo at 37.5 or 75 mg/L.The protein and mRNA expressions of Arg1 and iNOS in the treated cells were determined with Western blotting and qRT-PCR,and the concentrations of IL-6,IL-10,and IGF-1 in the supernatants were measured with ELISA.The viability and apoptosis of PC12 cells were detected using CCK-8 assay and flow cytometry.Results The isolated rat EMSCs showed high expressions of nestin,CD44,CD105,and vimentin.The obtained EMSCs-exo had a typical cup-shaped structure under transmission electron microscope with an average particle size of 142 nm and positivity for CD63,CD81,and TSG101 but not vimentin.In LPS-treated microglia,EMSCs-exo treatment at 75 mg/L significantly increased Arg1 protein level and lowered iNOS protein expression(P<0.05).EMSCs-exo treatment at 75 mg/L,as compared with the lower concentration at 37.5 mg/L,more strongly increased Arg1 mRNA expression and IGF-1 and IL-10 production and decreased iNOS mRNA expression and IL-6 production in LPS-induced microglia,and more effectively promoted cell survival and decreased apoptosis rate of H2O2-induced PC12 cells(P<0.05).Conclusion EMSCs-exo at 75 mg/L can effectively reduce the proportion of M1 microglia and alleviate neuronal apoptosis under oxidative stress to promote neuronal survival,suggesting its potential in controlling secondary spinal cord injury.