Objective To make sciatic nerve traction injury models of rabbit , in order to prospectively evaluate possibility and accuracy of diffusion tensor tracking (DTT) in sciatic nerve injures. Methods The right sciatic nerves of 32 New Zealand white rabbits were selected for traction injury , and the left sciatic nerves were the sham operation side. DTI scan was performed before and after the operation on 1st day , 3rd day, and 1 week, 2, 3, 4, 6 and 8th week respectively, and DTT was reconstructed. Then the length of reconstructed fiber tracts and fiber density index were calculated. After the MRI scan , the sciatic nerve was removed to perform pathologic examination at different time points. Results The difference of the length of reconstructed fiber tracts between nerve traction injury and sham operation side was significant at 1 day~2weeks after operation (P<0.05), while the difference was not significant at 3~8 weeks.The fiber density index of nerve traction injury and sham operation side was significantly different at 1 day~8 weeks(P<0.05). 1day after operation, myelin sheath of traction portion was obviously twisting. 3 days after operation , a large amount of myelin sheath broke down. 2 weeks after operation , axon, myelin sheath degeneration and regeneration coexisted at the same time. 8 weeks after operation , nerve fibers regenerated and restored to normal structure. Conclusion The length time curve and density index-time curve of nerve traction injury are consistent with the changes of pathology , which can be used as a supplementary method to evaluate the degeneration and regeneration in nerve injury.

Objective To explore the characteristics of diffusion weighted imaging (DWI) of lumbar sacral nerve roots (LSNR)in normal and degenerative lumbosacral vertebrae. Methods The research recruited 20 normal volunteers and 31 patients with spinal stenosis on conventional MRI and DWI scans in lumbosacral spine. We measured the areas from lumbar 3 to sacral 1 at the intervertebral spaces and reconstructed the 3D maximum intensity projection (MIP) and counted the apparent diffusion coefficient (ADC)of LSNR and ganglions. Results In the control group, 196 (98%) LSNR ran symmetrically and lateroinferiorly and 200 ganglions were well defined on MIP of DWI. In the patients group, 74 LSNR showed changes of compression on both T1WI and T2WI, in which DWI appeared thin and distorted in 59 (80%). The ADC value of LSNR were(1.70 ± 0.40)× 10-3 mm2/s and(1.98 ± 0.57) × 10-3 mm2/s separately in normal volunteers and patients (P=0.000), while the ADC values of ganglions were(1.42 ± 0.21)× 10-3 mm2/s and (1.54 ± 0.53)× 10-3 mm2/s respectively in normal volunteers and patients (P=0.000). Conclusion DWI can display the pattern and course of LSNR and ganglions, which indicate that ADC values of compressed LSNR and ganglions are higher than normal ones.

Objective:To analyze and summarize the clinical effects of 3D printed porous titanium-alloy prosthesis implantation in the treatment of long bone defects of lower extremities.Methods:We retrospectively studied the clinical cases with lower extremity bone defect treated by 3D printed porous titanium prostheses from December 2017 to November 2021. 18 patients who were followed up for more than 12 months were included in this study. The enrolled patients included 12 males and 6 females, with an average of 48.9±22.5 years (range, 13-79 years), and an average body mass index of 23.1±4.3 kg/m 2 (range, 17.2-27.1 kg/m 2). There were 14 osteomyelitis-derived bone defects and 4 nonunion-derived bone defects. The bone defect locations included 10 cases of femur and 8 cases of tibia. The average bone defect distance was 13.9±9.7 cm (range, 5.8-31.2 cm), and the proportion of the defect length to the long bone (femur of tibia) was average 33.7%±16.8% (range, 15.0%-63.0%). The clinical efficacy was comprehensively evaluated through gross observation, imaging evaluation, changes in the total length of lower extremities and long bones, femorotibial angle (FTA) measurement, lower extremity functional scale (LEFS), satisfaction, complications and other indicators, focusing on the stabilization mechanism of the prosthesis and the regeneration of new bone. Results:All 18 patients were followed up for 12-35 months, with an average of 16.3 months. Postoperative X-rays at 1, 3, 12 and 24 months showed that new bone could gradually creep along the prosthesis surface. The preoperative bone defect length of long bone and total length of lower limb were respectively 39.4±4.0 cm and 80.5±5.7 cm, which were different from those of the healthy side by 1.6±1.0 cm and 1.5±1.1 cm. One week after implantation, the length of long bone and lower limb was 39.9±3.5 cm and 80.9±6.2 cm, respectively, and the average difference was 1.0±0.6 cm and 0.9±1.1 cm compared with the healthy side. At the last follow-up, the length of long bone and lower limb was 39.7±3.6 cm and 80.9±7.8 cm, with an average difference of 1.8±1.1 cm and 1.0±0.7 cm from the healthy side. There were no significant differences in the length of long bone and lower limbs at the three time points before surgery, one week after surgery and the last follow-up ( F=0.12, 0.04; P>0.05). The average FTA of the affected limb was 174.7° (173.9°, 175.5°), 175.2°(173.5°, 176.4°), and 175.0°(173.5°, 176.3°) at three time nodes, before surgery, one week after surgery and the last follow-up, respectively, and there was no significant statistical difference in pairwise comparison ( Z=0.01, P>0.05). Patients had a mean LEFS score of 50 (46, 51) at the last follow-up, significantly higher than the preoperative score of 20 (17, 21) ( Z=-5.56, P<0.001). The mean satisfaction score of the 18 patients at the last follow-up was 9.7. Two patients (11.1%) had screw fractures but all 3D printed porous titanium alloy prostheses remained stable without significant loosening or displacement. Two patients (11.1%) had nail channel infection of external fixator, all patients with channel infection were cured by intravenous antibiotics combined with local disinfection and dressing change. Conclusion:The implantation of 3D printed porous titanium-alloy prosthesis could efficiently and safely repair the long bone defects of the lower extremities. The prosthesis could maintain stable in the early and middle postoperative period. The length of the long bones and lower limbs did not change significantly with the weight-bearing and functional exercise of the limbs. The new bone could gradually crawl and grow from both ends of the defect, and the patient's limb function recovered significantly, and the patient's satisfaction was high.

OBJECTIVE: To explore the molecular mechanism of curcumin in inhibiting the nucleotide-binding oligomerization domain like receptor family pyrin domain-containing(NLRP3) inflammatory bodies induced by silica(SiO_2) in mouse alveolar macrophages(AM). METHODS: AMs were isolated from the bronchoalveolar lavage fluid of specific pathogen free C57 BL/6 mice and divided into 6 groups. Among them, the AM of the control group received no stimulation; the AM in the SiO_2 stimulation group was stimulated with SiO_2 suspension at the final mass concentration of 50 mg/L; the AM in nuclear factor(NF-κB)inhibition group was pretreated with 5-(4-fluorophenyl)-2-urea-thiophene-3-formamide with a final concentration of 200 nmoL/L for 1 hour, the AM in the low-, medium-and high-dose curcumin groups were pretreated with curcumin with the final concentrations of 20, 40 and 50 μmol/L for 1 hour, respectively, and then stimulated with SiO_(2 )suspension with a final concentration of 50 mg/L. Samples were collected after 6 hours of incubation. The mRNA expression of NLRP3 inflammasome related genes such as NLRP3, Caspase-1 and interleukin(IL)-1β was detected by real-time fluorescence quantitative polymerase chain reaction. The secretion level of maturation IL-1β(mIL-1β) and IL-18 in AM was detected by enzyme-linked immunosorbent assay. The protein expression and secretion level of cleaved Caspase-1, precursor-IL-1β(pro-IL-1β) and mIL-1β were analyzed by Western blotting. RESULTS: The mRNA relative expression of NLRP3, Caspase-1 and IL-1β, and the secretion levels of mIL-1β and IL-18, and the protein relative expression of Caspase-1, pro-IL-1β and mIL-1β, as well as the secretion levels of cleaved Caspase-1 and mIL-1β increased in the SiO_2 stimulated group compared with the control group(P<0.05). Except for the relative expression and the secretion level of cleaved Caspase-1, the other 8 indexes in the NF-κB inhibition group were lower than that in the SiO_2 stimulation group(P<0.05). Except for the relative expression of cleaved Caspase-1 and mIL-1β proteins in the low-dose curcumin group, the relative expression of all the above 10 indexes was lower in the three curcumin treated groups than that in the SiO_2 stimulation group(P<0.05). In addition, all the above indexes decreased with the increase of curcumin intervention dose(P<0.05). The mRNA relative expression of NLRP3 and IL-1β, and the protein relative expression of pro-IL-1β increased in the medium-dose curcumin group(P<0.05), the secretion levels of mIL-1β and IL-18, as well as the protein relative expression and secretion levels of cleaved Caspase-1 and mIL-1β decreased(P<0.05), compared with the NF-κB inhibition group. CONCLUSION: Curcumin can inhibit SiO_2-induced AM NLRP3 inflammasome activation in a dose-response relationship. This process may be related to the inhibition of NF-κB signaling pathway by curcumin and the down-regulating NLRP3 inflammasome-related genes at the transcriptional level. The important mechanism may be that curcumin directly blocks the activation, assembly, and downstream shearing of NLRP3 in inflammasomes.