Objective:To explore the changes in the expression of Tau protein and phosphorylated Tau (p-Tau) protein in neurons after spinal cord ischemia-reperfusion injury (SCII).Methods:Ninety-six healthy adult SD rats were randomly divided into a sham operation group ( n=48) and a SCII group ( n=48). Based on the reperfusion time of 3 h, 6 h, 12 h, 24 h, 48 h and 72 h, the SCII group was divided into 6 subgroups ( n=8 per subgroup). Immunohistochemical staining was used to observe the apoptosis of spinal cord neurons in the L 4-L 5 segments and the expression of Tau protein and p-Tau protein. Results:In the sham operation group, the neuron cells were intact, mainly concentrated in the gray matter. Tau protein was seen in a small number of neuron cells, and a small amount of filamentous p-Tau protein in the pernucleus and cytoplasm. There was no significant difference between Tau protein and p-Tau protein expression in neurons at each time point ( P>0.05). In the SCII group, scattered Tau protein was seen in the apoptotic cells while there was a strong positive expression of Tau protein in the non-apoptotic cells. The expression of Tau protein in the SCII group gradually increased after injury, reaching a peak at 48h and plateauing at 72 h, and was significantly different between any 2 time points (except for 72 h) ( P<0.05). In the SCII group, the positive expression of p-Tau protein was observed in the cytoplasm of the apoptotic cells in strips and sheets. It increased rapidly within 6 h but did not change significantly after 6 h, showing no significant difference between any 2 time points afterwards ( P>0.05). There was a statistically significant difference in the expression of Tau protein and p-Tau protein between the SCII group and the sham operation group at each time point ( P<0.05). Conclusion:It is hopeful to reduce the severity of spinal cord injury by regulating the expression of Tau protein and p-Tau protein within 6 to 48 hours after SCII.

Objective:To compare the clinical effects between proximal humerus internal locking system (PHILOS) inverted and a posterior single plate in the anterior percutaneous minimally invasive internal fixation for distal humeral shaft fractures.Methods:A retrospective study was conducted to analyze the data of 65 patients with distal humeral shaft fracture who had been treated from January 2018 to May 2021 at Department of Orthopaedics, The Second Hospital of Fuzhou. The patients were assigned into 2 groups according to different treatment methods. In the observation group of 30 cases subjected to anterior percutaneous minimally invasive internal fixation with PHILOS inverted: 20 males and 10 females with an age of (41.5±11.6) years; type A in 5 cases, type B in 14 cases, and type C in 11 cases by AO fracture classification. In the control group of 35 cases subjected to anterior percutaneous minimally invasive internal fixation with a posterior single plate: 23 males and 12 females with an age of (39.9±11.2) years; type A in 7 cases, type B in 17 cases, and type C in 11 cases by AO fracture classification. The preoperative general data, operation time, intraoperative blood loss, total incision length, fracture healing time, and shoulder and elbow VAS scores, Constant-Murley shoulder function score, Mayo elbow performance score (MEPS), and complications at the last follow-up were recorded and compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). There were no significant differences either in operation time, fracture healing time, or shoulder or elbow VAS pain score, Constant-Murley shoulder function score, or MEPS at the last follow-up between the 2 groups ( P>0.05). The intraoperative blood loss was (59.7±26.6) mL in the observation group and (165.7±86.4) mL in the control group, and the total incision length was (10.7±2.1) cm in the observation group and (18.6±2.7) cm in the control group, showing statistically significant differences between the 2 groups ( P<0.01). There was no injury to the radial nerve or musculocutaneous nerves, incision infection or fracture nonunion in the observation group. There were 4 cases of iatrogenic radial nerve injury, 2 cases of incision infection and 1 case of fracture nonunion in the control group, yielding a complication rate of 20.0% (7/35). The difference in the incidence of complications was significant between the 2 groups ( P<0.01). Conclusion:In the treatment of distal humeral shaft fracture with anterior percutaneous minimally invasive internal fixation, PHILOS inverted has advantages of less soft tissue damage, less intraoperative bleeding, and a lower risk of iatrogenic radial nerve injury than the posterior single plate.