Objective To study the regulating mechanisms of cobaltous chloride (CoCl2)induced hypoxia on muscle atrophy.Methods The mouse skeletal C2C12 myotube line was used as the cell model and divided into a control group,a CoCl2 group,a 3-Methyladenine(3MA)group and a CoCl2+3MA group.The control group was not given any treatment,the CoCl2 group was treated with 200 μM CoCl2 to induce hypoxia,and the 3MA group or CoCl2+3MA group was treated with 5 mM 3MA in the absence or presence of 200 μM CoCl2.The Giemsa stain was conducted to observe the morphology of myotubes.The multifunctional microplate reader was utilized to quantify the reactive oxygen species (ROS)expression.The autophagosome was observed by using the transmission electron microscopy.The mRNA and protein expression of hypoxia-inducible factor-1α(HIF-1α),Bcl2/adenovirus E1B19kDa interacting protein 3(BNIP3),microtubule associated protein1 light chain 3(LC3)were detected using the quantitative real time polymerase chain reaction (QRT-PCR)and Western blotting (WB).Moreover,3-Methyladenine(3MA)was used to suppress autophagy and the expression of muscle atrophy F-box(MAF-bx)was detected.Results More spindly ring-shaped myotubes were formed in the control group,while CoCl2 induced myotubes atrophy and rupture.The expression of ROS increased significantly in the CoCl2 group compared with the control group(t=-4.965,P=0.008).Transmission electron microscopy results showed autophagosome formation induced by CoCl2,and significant improvement in the HIF-1α,BNIP3 and LC3 in the CoCl2 group compared with the control group(P＜0.05).The protein expression of MAFbx decreased when co-cultured with CoCl2 and 3MA(F=18.246,P=0.001).Conclusions The skeletal muscle atrophy caused by CoCl2 induced hypoxia may be associated with autophagy promoted by the HIF-1α/BNIP3 signal pathway,and inhibition of hypoxia induced autophagy can partly reduce the atrophy in skeletal C2C12 myotubes.

Objective:To study the dynamic changes of cellular immune function in peripheral blood of trauma patients and its role in the evaluation of traumatic complications.Methods:A prospective cohort study design was conducted. Patients with blunt trauma admitted to Chongqing Emergency Medical Center from November 2019 to January 2020 were consecutively enrolled. The peripheral blood samples were collected at 1, 3, 5, 7, and 14 days after injury. The expressions of CD64, CD274, and CD279 on the surface of neutrophils, lymphocytes, and monocytes as well as CD3 +, CD4 + and CD8 + T lymphocyte subsets were measured by flow cytometry. The trauma patients were divided into different groups according to the injury severity score (ISS) and sepsis within 28 days after injury, respectively. The dynamic changes of cellular immune function in different time points after injury and differences between different groups were compared. Furthermore, the correlation with acute physiology and chronic health evaluation Ⅱ (APACHEⅡ), sequential organ failure assessment (SOFA), and ISS were evaluated by Pearson correlation analysis. Results:A total of 42 patients with trauma were finally enrolled, containing 8 severe trauma patients with ISS greater than 25 scores, 17 patients with ISS between 16 and 25 scores, and 17 patients with ISS less than 16 scores. The sepsis morbidity rates were 14.3% (n = 6) within 28 days after injury. CD64 index and CD4 +T lymphocyte subsets were significantly increased at different time points after trauma (H = 15.464, P = 0.004; F = 2.491, P = 0.035). The CD64 index and positive rates of CD279 in neutrophils, lymphocytes, and monocytes were increased with the severity of injury at day 1 and day 3 after injury, respectively. At the first day after injury, CD64 index were 2.81±1.79, 1.77±0.92, 3.49±1.09; positive rate of CD279 in neutrophils were 1.40% (0.32%, 2.04%), 0.95% (0.44%, 2.70%), 12.73% (3.00%, 25.20%); positive rate of CD279 in lymphocytes were 3.77% (3.04%, 5.15%), 4.71% (4.08%, 6.32%), 8.01% (4.59%, 11.59%); positive rate of CD279 in monocytes were 0.57% (0.24%, 1.09%), 0.85% (0.22%, 1.25%), 6.74% (2.61%, 18.94%) from mild to severe injury groups, respectively. The CD64 index in severe injury group was significantly higher than that in moderate group, and the positive rates of CD279 in neutrophils, lymphocytes and monocytes of severe injury patients were higher than those in other two groups (all P < 0.05). At 3rd day after injury, compared to moderate group, severe injury patients had significantly higher CD64 index and positive rate of CD279 in lymphocytes [4.58±2.41 vs. 2.43±1.68, 7.35% (5.90%, 12.28%) vs. 4.63% (3.26%, 6.06%), both P < 0.05]. Compared with the non-sepsis patients, the sepsis patients had significantly higher CD64 index and positive rate of CD279 in monocytes at day 1 after injury [4.06±1.72 vs. 2.36±1.31, 3.29% (1.14%, 12.84%) vs. 0.67% (0.25%, 1.48%), both P < 0.05], and positive rate of CD279 in lymphocytes significantly higher at 3rd day after injury [8.73% (7.52%, 15.82%) vs. 4.67% (3.82%, 6.21%), P < 0.05]. In addition, correlation analysis showed that positive rate of CD279 in lymphocytes was positively correlated with SOFA and ISS, respectively (r values were 0.533 and 0.394, both P < 0.05), positive rate of CD279 in monocytes was positively correlated with APACHEⅡ, SOFA and ISS scores, respectively (r values were 0.579, 0.452 and 0.490, all P < 0.01), positive rate of CD279 in neutrophils was positively correlated with APACHEⅡ and ISS, respectively (r values were 0.358 and 0.388, both P < 0.05). Conclusions:CD64 index and CD279 expression in neutrophils, lymphocytes, and monocytes are significantly related to the severity and prognosis of trauma. Dynamic monitoring the cellular immune function may be helpful for assessing the prognosis of trauma patients.

Objective To compare the therapeutic effects between anterior internal fixator (INFIX) and external fixator (EXFIX) for anterior pelvic ring fracture.Methods A retrospective study was conducted on the 66 patients with anterior pelvic ring fracture who had been treated surgically from January 2016 to June 2017 at Department of Spinal Surgery,Hospital Affiliated to Southwest Medical University and at Department of Orthopedics,Union Hospital Affiliated to Tongji Medical College.They were divided into an observation group and a control group according to their fixation of the anterior pelvic ring.In the observation group of 33 cases fixated with INFIX,there were 20 males and 13 females,aged from 32 to 47 years (38.8 ±4.8 years).By the Tile's classification,15 of them belonged to type B and 18 to type C.In the control group of another 33 patients fixated with EXFIX,there were 19 males and 14 females,aged from 33 to 48 years (39.5 ±4.6 years).By the Tile's classification,14 of them belonged to type B and 19 to type C.The 2 groups were compared in terms of postoperative fracture reduction,pelvic function and complications.Results The 66 patients were followed up for an average of 13.7 months(from 12 to 18 months).According to the Matta criteria for fracture reduction,21 cases were excellent,9 good,2 fair and one poor in the observation group (excellent and good rate:90.9％);18 cases were excellent,8 good,5 fair and 2 poor in the control group (excellent and good rate:78.8％).The difference was statistically significant between the 2 groups (P ＜ 0.05).The pelvic function assessed by the Majeed criteria at the final follow-up was excellent in 21 cases,good in 10,fair in one and poor in one in the observation group (excellent and good rate:93.9％);it was excellent in 17 cases,good in 9,fair in 4 and poor in 3 in the control group (excellent and good rate:78.8％).The difference was also statistically significant between the 2 groups (P ＜ 0.05).The incidence of injury to the lateral femoral cutaneous nerve was 9.1％ (3/33) for the observation group and 6.1％ (2/33) for the control group,showing no significant difference between the 2 groups (P ＞ 0.05).The incidences of screw loosening and pin track infection were significantly lower in the observation group than in the control group[0 versus 24.2％ (8/33) and 0 versus 18.2％ (6/33),respectively] (both P ＜ 0.05).Conclusion Compared with EXFIX,INFIX can lead to better clinical outcomes and fewer operative complications in the treatment of anterior pelvic ring fractures.