Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

Objective To investigate the effect of E2 signaling in myofibers on muscular macrophage efferocytosis in mice with cardiotoxin-induced acute skeletal muscle injury.Methods Female wild-type C57BL/6 mice with and without ovariectomy and male C57BL/6 mice were given a CTX injection into the anterior tibial muscle to induce acute muscle injury,followed by intramuscular injection of β-estradiol(E2)or 4-hydroxytamoxifen(4-OHT).The changes in serum E2 of the mice were detected using ELISA,and the number,phenotypes,and efferocytosis of the macrophages in the inflammatory exudates and myofiber regeneration and repair were evaluated using immunofluorescence staining and flow cytometry.C2C12 cells were induced to differentiate into mature myotubes,which were treated with IFN-γ for 24 before treatment with β-Estradiol or 4-OHT.The treated myotubes were co-cultured with mouse peritoneal macrophages in a 1:2 ratio,followed by addition of PKH67-labeled apoptotic mouse mononuclear spleen cells induced by UV irradiation,and macrophage efferocytosis was observed using immunofluorescence staining and flow cytometry.Results Compared with the control mice,the female mice with ovariectomy showed significantly increased mononuclear macrophages in the inflammatory exudates,with increased M1 cell percentage,reduced M2 cell percentage and macrophage efferocytosis in the injured muscle,and obviously delayed myofiber regeneration and repair.In the cell co-culture systems,treatment of the myotubes with β-estradiol significantly increased the number and proportion of M2 macrophages and macrophage efferocytosis,while 4-OHT treatment resulted in the opposite changes.Conclusion In injured mouse skeletal muscles,myofiber E2 signaling promotes M1 to M2 transition to increase macrophage efferocytosis,thereby relieving inflammation and promoting muscle regeneration and repair.

Paroxysmal sympathetic hyperactivity (PSH) is mainly secondary to a variety of acquired brain injuries, with the highest incidence of traumatic brain injury. Multiple symptoms such as paroxysmal tachycardia, shortness of breath, hypertension, hyperthermia and dystonia can occur simultaneously and repeatedly. The pathophysiological mechanism of PSH is complex. At present, drug treatment is mainly used to control symptoms; however, the combined use of multiple drugs will bring different degrees of toxic and side effects to multiple organs such as liver, kidney and lung while inhibiting sympathetic excitement. This paper mainly reviews the recent advance in non-drug treatment of PSH after craniocerebral injury from 4 aspects: nutritional support, hyperbaric oxygen therapy, avoidance of adverse stimulation and family support to standardize the PSH comprehensive management, and reduce episodes in order to improve prognosis and provide reference for clinical treatment.

Since 2010, the incidence of severe fever with thrombocytopenia syndrome (SFTS) has been increased. Owing the progress in diagnosis and treatment, the overall mortality of SFTS in China has decreased, while the mortality in critical SFTS patients is still high. In order to provide guidance and working procedures for clinicians to diagnose and treat critical SFTS, the National Medical Center for Major Public Health Events invited experts to discuss and formulate this consensus based on their experience and up-to-date knowledge on SFTS.

ObjectiveTo investigate epidemiological characteristics and influencing factors of non-suicidal self-injury （NSSI） behaviors among middle school students in Jiangmen. MethodsA total of 1 220 middle school students in Jiangmen were selected for the study through stratified random sampling from November to December 2020. The self-compiled general demographic questionnaire， Coping Style Scale for Middle School Students， Olweus Bully/Victim Questionnaire （BVQ）， Social Support Scale for Adolescents， and Center for Epidemiologic Studies-Depression Scale （CES-D） were used for the assessment. Then binary Logistic regression analysis was performed to screen the factors influencing NSSI behaviors in students. ResultsA total of 204 middle school students （16.72%） were found to be engaged in NSSI behaviors， of whom 67 were male and 137 were female. There were statistically significant differences between the NSSI group and the non-NSSI group in terms of gender， school period， lodging， peer relationship and academic performance （χ²=22.162， 7.247， 6.541， 45.787， 25.097， P<0.05 or 0.01）. Compared with the non-NSSI group， the NSSI group scored higher on CES-D （t=-14.240） and BVQ （t=-5.952）， lower on Social Support Scale for Adolescents （t=9.238）. Within the Coping Style Scale for Middle School Students， NSSI group had lower problem-focused coping score （t=7.148） and higher emotion-focused coping score （t=-7.038） than those of non-NSSI group. The detection rates of school bullying， verbal and relational bullying were higher in NSSI group compared with non-NSSI group （χ²=34.215， 29.785，16.465）. The differences were statistically significant （P<0.01）. Binary Logistic regression showed that depression （OR=1.090， P<0.01） and school bullying （OR=1.492， P<0.05） entered into the regression model. ConclusionThe situation of NSSI behaviors of middle school students in Jiangmen is serious， and depression and school bullying are risk factors affecting NSSI behaviors in students.

Osteonecrosis is the most common disorder in femoral head and scaphoid. However, avascular necrosis (AVN) in metacarpal head is a rare disease. In the present study, a 14-year-old male patient complained of right-hand pain with a limited range of motion for one month. Physical examination showed that the active flexion was 70° and the extension was limited to 30° of the metacarpophalangeal (MCP) joints. The grip strength decreased to 60% of the contralateral hand. X-rays demonstrated flattening and sclerotic changes in the long finger and ring finger of metacarpal head. CT scanning indicated cystic, osteochondral defects and sclerotic changes in metacarpal head. Imaging examination further confirmed the diagnosis of AVN in the long metacarpal finger and ring finger. After conservative treatments including splint immobilization, non-steroidal anti-inflammatory drugs (NSAIDs) and physiotherapy, the local pain symptoms of the MCP joint gradually disappeared. The range of motion of MCP joint returned to normal with the grip strength score as 105% of the contralateral hand. MRI confirmed excellent remodeling and regeneration in the metacarpal head at two years later. The clinical characteristics, diagnosis and treatments of AVN of metacarpal head were reviewed. Although radiograph examination is commonly used, early-stage osteonecrosis of the metacarpal head should be confirmed by MRI. Given the rarity of this disorder, there is no consensus on the treatments. Metacarpal necrosis is the more common disorder in adolescent patients with a history of trauma. Considering the potential of bone remodeling, juveniles with metacarpal head necrosis could recover by conservative treatments.

Objective:To assess the clinical effects of closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique in the treatment of the fifth metacarpal neck fracture.Methods:In this retrospective study, 26 patients with the fifth metacarpal neck fracture were treated by closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique at Department of Orthopaedics, Central Hospital of Karamay from August 2015 to October 2017. They were 23 males and 3 females, aged from 12 to 53 years with an average age of 25.2 years. In the intramedullary nailing, a Kirschner wire pre-bent by 10° to 15° was inserted from the base of the fifth metacarpal into the medullary canal before closed reduction. After satisfactory reduction was achieved, the Kirschner wire was inserted across the fracture site into the metacarpal head for further reduction and fixation using rod rotation technique. After operation, a plaster was applied to protect the fixation for 2 weeks. Functional exercise was started after removal of the plaster. The Kirschner wire was not removed under local anaesthesia at the outpatient department until about 10 to 16 weeks postoperation when X-ray showed fracture healing. Records of their operation time, head/shaft angle of the fifth affected metacarpal, active range of motion of the metacarpophalangeal joints and Total Active Movement (TAM) of hand function at the last follow-up were collected.Results:Their operation time averaged 21 minutes (from 12 to 35 minutes). Anatomical reduction was achieved in 23 cases but not in 3 ones whose metacarpal head/shaft angle and alignment were obviously improved. Follow-ups for 6 to 29 months (average, 15.8 months) showed all the patients obtained solid fracture healing with no infection or delayed fracture healing. The head/shaft angle was improved significantly from preoperative 61.2°±11.2° to postoperative 14.7°±3.5° ( P<0.05) which was not significantly different from that of the healthy side (14.6°±1.7°)( P>0.05). The active range of motion of the metacarpophalangeal joint was 89.3°±4.2° after fixation removal, not significantly different from that of the healthy side (90.7°±1.5°) ( P>0.05). According to TAM scores at the last follow-up, 22 cases were rated as excellent, 3 as good and one as fair. Conclusion:In the treatment of the fifth metacarpal neck fracture, closed reduction and intramedullary fixation with antegrade Kirschner wire plus rod rotation technique is effective, because it is simple and limitedly invasive, and leads to limited complications, low costs and secondary reduction.

To explore the immobilization of target proteins for screening libraries of ligand mixtures, magnetic submicron particles (MSP) functionalized with Ni²⁺-NTA and carboxyl were compared for the immobilization of Mycobacterium tuberculosis dihydrofolate reductase (MtDHFR). MtDHFR fused with 6×His was expressed, purified and characterized for kinetics. MtDHFR was immobilized on Ni²⁺-NTA-functionalized MSP directly and carboxyl-functionalized MSP upon activation. The immobilization capacity, residual activity, thermostability and affinities for putative inhibitors were characterized. MtDHFR immobilized on Ni²⁺-NTA-functionalized MSP retained about 32% activity of the free one with the immobilization capacity of (93±12) mg/g of MSP (n=3). Ni²⁺ and EDTA synergistically inhibited MtDHFR activity, while Fe³⁺ had no obvious interference. MtDHFR immobilized on carboxyl-functionalized MSP retained (87±4)% activity of the free one with the immobilization capacity of (8.6±0.6) mg/g MSP (n=3). In 100 mmol/L HEPES (pH 7.0) containing 50 mmol/L KCl, there was no significant loss of the activities of the free and immobilized MtDHFR after storage at 0 °C for 16 h, but nearly 60% and 35% loss of their activities after storage at 25 °C for 16 h, respectively. The inhibition effects of methotrexate on the immobilized and free MtDHFR were consistent (P>0.05). The immobilization of MtDHFR on carboxyl-functionalized MSP was thus favorable for higher retained activity and better thermostability, with promise for rapid screening of its ligand mixtures.
Enzyme Stability ; Enzymes, Immobilized ; Hydrogen-Ion Concentration ; Kinetics ; Ligands ; Magnetite Nanoparticles ; Mycobacterium tuberculosis ; Temperature ; Tetrahydrofolate Dehydrogenase

Autophagy is a dynamic process that allows recycling of long-lived proteins and damaged organelles into biosynthetic materials for maintaining the normal cellular homeostasis. Recently, accumulating evidence has indicated that autophagy played important roles in the pathogenesis of neuronal diseases. In this article, the research progress of autophagy in the pathogenesis and regulation mechanism of common nervous system diseases were reviewed to deepen the understanding of autophagy, and arouse researchers' attention on dynamic regulation of autophagy and alleviating autophagic flow injury.

An auxiliary training system was explored for the development of creativity of long-termsystem medical undergraduates through scientific researches in spare time.In practice,professionals from research groups of different disciplines were recruited for developing wide-scope theoretical and technical bases of the undergraduates through training among these research groups followed by focused researches on topics of the running projects of these professionals.The undergraduates were engaged in a serial of research activities,including the discovery of problems for reasoning out scientific research projects,the writing of their project proposals,the summary of their data and the writing of reports,to develop their creativity and their qualification for scientific researches.