Objective:To compare our self-designed elastic syndesmosis hook plate (ESHP) and suture-button technique in treatment of injury to the distal tibiofibular syndesmosis.Methods:A retrospective study was conducted of the 53 patients who had been treated at Military Orthopaedic Center, 909 Hospital of Joint Service Support Force of PLA for ankle fractures complicated with syndesmosis injury by ESHP or suture-button technique from March 2013 to March 2017. Of them, 28 were treated by ESHP (ESHP group: 15 males and 13 females aged from 26 to 60 years) and 25 by suture-button technique (suture-button group: 14 males and 11 females aged from 24 to 59 years). The 2 groups were compared in terms of syndesmosis fixation time, postoperative incision bleeding, hospital stay, and ankle dorsiflexion and plantarflexion and ankle function by Baird-Jackson scoring at 3, 6, 12 months after surgery. Postoperative complications were observed.Results:The 2 groups were comparable because there was no statistically significant deference in general data between the 2 groups ( P>0.05). Surgery went on uneventfully in all the patients. The syndesmosis fixation time [(9.7±2.2) min] and postoperative incision bleeding [(49.3±10.4) mL] in the ESHP group were significantly less than in the suture-button group [(16.2±1.4) min and (62.4±6.3) mL] ( P<0.05); the maximum plantar flexion (29.9°±1.3°) and Baird-Jackson scores (87.2±2.9) at 3 months after surgery in the ESHP group were significantly greater than in the suture-button group (22.8°±1.3° and 78.7±4.1) ( P<0.05). There were no significant differences between the 2 groups in hospital stay, maximum plantar flexion at postoperative 6 or 12 months, maximum dorsiflexion at postoperative 3, 6 or 12 months, or Baird-Jackson scores at postoperative 6 or 12 months (all P>0.05). This cohort was followed up for 12 to 14 months (average, 12.5 months). All fractures united during follow-up and all the implants were removed around postoperative 12 months. Follow-up within 12 months observed internal fixation failure caused by metal fatigue in one case in the ESHP group, and internal fixation irritation in one case, internal fixation failure in 2 cases and internal fixation sinking and osteolysis in one case in the suture-button group. Conclusion:Compared with the suture-button technique, treatment of injury to the distal tibiofibular syndesmosis with ESHP may lead to shorter fixation time, less postoperative bleeding and complications, and faster functional recovery of the ankle.

This study is to investigate the impairment and possible mechanism of endothelium-dependent relaxation of mice mesenteric arteries induced by mmLDL. Wire myography was employed to examine endothelial function of mesenteric arteries. Ultramicrostructure of mesenteric vascular beds were detected by transmission electron microscope. The results showed that endothelium cell edema and peeling, vascular elastic membrane fracture traces in mmLDL group. Endothelium-dependent relaxation was decreased in a time-dependent and dose-dependent manner by using mmLDL, compared with normal arteries. In endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation, the Rmax and pIC50 were decreased from (63 +/- 5) % and 6.42 +/- 0.09 of normal saline control to (31 +/- 3) % and 5.67 +/- 0.07 in mmLDL group (P < 0.001, P < 0.001), respectively. In nitric oxide (NO)-mediated relaxation, the Rmax and pIC50 were decreased from (45 +/- 4) % and 5.93 +/- 0.08 in normal saline control to (32 +/- 4) % and 5.43 +/- 0.11 in mmLDL group (P < 0.05, P < 0.01), respectively. There is no significant alteration of prostacyclin I2 (PGI2) pathway between these two groups. In conclusion, mmLDL induced the impairment of the ultramicrostructure of mesenteric vascular endothelium cell as well as the endothelium-dependent relaxation. The latter includes the dysfunction of NO- and EDHF pathway mediated endothelium-dependent relaxation.

Objective To investigate the features of intravertebral vacuum phenomenon (IVP)in vertebral compression fractures (VCFs). Methods Two hundred and nine patients with VCFs underwent percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP). The biopsies and the images of X-ray, CT, MRI of VCFs were obtained. The consistency between IVP and osteonecrosis on histology and the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and Youden index of IVP for diagnosing local osteonecrosis in VCFs were analyzed. Fisher exact probability test was used to analyze the coherence between IVP and osteonecrosis. Results Histological examination revealed 146(69.9%) osteoporoses, 10 (4.8%) osteonecroses with osteoporoses, 53 (25.4%) neoplasms. Prior to surgery,10 cases of IVP were found. Plain radiograph showed horizontally oriented lucent cleft in the vertebral body;CT further confirmed the location of gas;T_1-weighted MR image appeared hypointensity,while the signal intensity of T_2-weighted MR image differed, depending on the duration of recumbency. Nine of 10 patients with IVP showed osteonecrosis on histology, while 9 of 10 patients with osteonecrosis contained IVP. The association of osteonecrosis on histology and the IVP was statistically significant(P <0.01). The PPV, NPV, sensitivity, specificity, and Youden index for diagnosing local osteonecrosis was 90% (9/10), 99.5% (198/199), 90.0% (9/10), 99.5% (198/199), and 0.9, respectively. Conclusion The IVP is stongly suggestive of local osteonecrosis in vertebral compression fracture.

Research based learning (RBL) is a brand new teaching mode implicated by Shanghai Jiaotong University School of Medicine specifically designed for clinical undergraduates.The nature of RBL is about exploring unknown knowledge and designing and executing comprehensive experiments.RBL aims at creating an open,active student participation,and close student-mentor interaction teaching mode.IBL includes literature study,research aim selection,experiment design and implementation,statistical analysis,results and conclusions,final report writing and defense of the report.Our experience indicates that RBL can substantially improve students' scientific logic and critical thinking and experimental skills,and develop the spirit of a team-player.This scientific training enables students to receive more comprehensive scientific training,facilitate their subsequent clinical research and practice,and assist them to participate in more international scientific exchanges.We propose that the RBL mode should be adopted for clinical student education in other universities.

Objective To evaluate the impact of the percentage of residual blasts in bone marrow at the end of induction chemotherapy ( T1 ) or during myelosuppression phase (T2) on prognosis of de novo acute myeloid leukemia(AML) (non M3) in 105 cases.To refine AML risk-stratification by combining the percentage of residual blast cells (T1 or/and T2) with cytogenetic data based the South West Oncology Group (SWOG) criteria.Methods The data of 105 de novo AML ( non M3 ) patients hospitalized between January 1st 1999 and February 1st 2008 were retrospectively reviewed.Results were analyzed with SPSS15.0 software.Results ( 1 ) Patients were divided into two subgroups by a cutoff of 5% residual bone marrow blasts at T1 or 12 time point.Patients with percentage of residual bone marrow blast cells <5% had better complete remission (CR) rate,relapse-free survival (RFS) and overall survival (OS) than the patients with percentage ≥5% at T1 or T2.The percentage of residual bone marrow blast cells at T1 was correlated with that at T2.(2) The prognosis of patients with intermediate karyotypes with percentage < 5 % at T1 or T2 was similar to that of the patients with favorable karyotypes.The patients with intermediate karyotypes and percentage of residual bone marrow blasts ≥5% at TI or T2 are defined as a subgroup with prognosis similar to that of patients with unfavorable karyotypes.(3) COX regression analysis showed that the percentage of residual bone marrow blasts at T1 or T2 is an independent prognostic factor of AML.The percentage of residual bone marrow blasts at T1 may be more helpful in prognostification than that at T2.Conclusion AML patients with percentage of residual bone marrow blasts < 5% after induction chemotherapy ( T1 or T2) have better CR rate,RFS,OS than the patients with percentage ≥5% at the same time point.Combination of cytogenetics and percentage of residual bone marrow blasts at T1 or T2 is helpful to divide patients with intermediate karyotypes into two subgroups with different prognosis.Thus,a better decision of treatment strategy can be designed.

Knockout is an important method for gene function study, while vector is the core of gene knockout. In order to obtain an effective vector for rapid construction of mutant and essentiality identification of the corresponding gene, we constructed a recombinant plasmid named plDM-T based on the temperature-sensitive and replication- defective plasmid plDM1 by inserting an Xcm I adapter into the EcoR I and Pst I sites of pIDM1. Digesting with Xcm I, pIDM-T can be prepared as a linear T-vector for PCR products cloning and be used to knockout the corresponding gene in the genome with insertion duplication mutagenesis. After the verification of temperature sensitivity of the replication of the plasmid, we cloned two Salmonella pullorum genes eno and ybdr into the constructed pIDM-T, and two recombinant plasmids pIDM-T_eno and pIDM-T_ybdr were identified. The recombinant plasmids were then transformed into S. pullorum strain CVCC527 and the IPC (Integration rate per cell) values were calculated. As a result, we identified the eno gene as an essential gene and the ybdr as a non-essential gene in CVCC527. We verified the correctness of recombination site in ybdr recombinant 527 clones (Sal delta ybdr) by PCR and sequencing. The pIDM-T vector can be used for gene knockout in S. pullorum, as well as the identification of essentiality of the corresponding genes, which offers an effective and rapid tool for gene function study in Salmonella.
Cloning, Molecular ; Gene Knockout Techniques ; Genetic Vectors ; genetics ; metabolism ; Plasmids ; genetics ; Recombinant Proteins ; genetics ; metabolism ; Recombination, Genetic ; Salmonella ; classification ; genetics

Hypertrophic obstructive cardiomyopathy(HOCM)is a hereditary cardiac disorder characterized primarily by septal hypertrophy and left ventricular outflow tract obstruction.Traditional therapeutic modalities,such as medications and surgeries,do not yield satisfactory outcomes in a subset of patients.The advancements have been made in novel treatments,including new drugs and percutaneous intramyocardial septal radiofrequency ablation(PIMSRA),still need further observation to obtain long-term efficacy and safety.In recent years,stereotactic body radiation therapy(SBRT)has emerged as an innovative non-invasive approach for treating HOCM.Studies indicate that SBRT allows for precise targeting of the hypertrophied septal region,causing both direct and indirect damage to targeted myocardial cells.This can alleviate left ventricular outflow tract obstruction and myocardial ischemia,fulfilling the therapeutic objective.For those with HOCM who neither respond well to medications nor are surgical candidates,SBRT offers a potential new therapeutic alternative.However,the latent risks of radiation therapy persist,such as the onset of radiation-induced heart disease(RIHD).The preliminary investigations guarantee the safety and feasibility of SBRT in HOCM management,an increased volume of clinical studies and prolonged follow-up data are essential to evaluate its real efficacy and potential hazards.In addition,research regarding the therapeutic mechanisms of SBRT for HOCM,optimal dosages and treatment durations,indications and contraindications,prevention of complications,and enhancing the precision of radiation therapy,still needs to be further exploration,to determine the best therapeutic strategies.

Objective:To observe the clinical effect of retrograde distal tibial intramedullary nail fixation in the treatment of proximal ankle fracture of the distal tibia.Methods:A three-dimensional CT examination of 40 adult tibias was performed to measure anatomical indicators such as the posterior medial posterior torsion angle of the distal tibia, the height of torsion, and the height of the safety zone for nail placement. Based on the anatomy database of the human skeleton model, a retrograde distal tibial nail and its supporting instruments were developed in accordance with the anatomical characteristics of the distal tibia and the proximal ankle of Chinese people. From June 2019 to June 2023, a total of 25 patients with distal tibial proximal ankle fractures treated with retrograde intramedullary nail internal fixation in the 909th Hospital were retrospectively analyzed. There were 18 males and 7 females, aged 41.3±10.8 years (range, 22-65 years). The sample size was 1∶1 matched according to gender and age. Twenty-five patients with distal tibial proximal ankle fractures who underwent antegrade intramedullary nail fixation during the same period were matched, including 20 males and 5 females, aged 41.2±9.4 years (range 19-60 years). The reduction quality, postoperative Baird-Jackson score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score, ankle range of motion and complications were observed.Results:All patients were successfully operated and followed up for 14.4±3.5 months (range, 12-24 months). The intraoperative blood loss and hospitalization time in retrograde intramedullary nail group were 33.12±7.38 ml and 10.32±1.75 d, less than 49.04±10.22 ml and 13.16±2.69 d in antegrade intramedullary nail group, and the difference was statistically significant ( P<0.05). The reduction quality was excellent in 23 cases and good in 2 cases in the retrograde intramedullary nail group, and was excellent in 17 cases and good in 8 cases in the anterograde intramedullary nail group. The proportion of excellent reduction quality in the retrograde intramedullary nail group was higher than that in the anterograde intramedullary nail group, and the difference was statistically significant (χ 2=4.500, P=0.034). The Baird-Jackson score and AOFAS ankle and hindfoot score in the retrograde intramedullary nail group were 85.6±2.5 and 85.8±3.3 at 3 months after operation, lower than those at 1 year after operation 95.3±3.1 and 95.8±3.6, and the difference was statistically significant ( P<0.05). The Baird-Jackson score and AOFAS ankle and hindfoot score of the antegrade intramedullary nail group were 85.1±3.3 and 86.1±2.5 at 3 months after operation, lower than 95.2±2.7 and 94.9±3.5 at 1 year after operation, and the difference was statistically significant ( P<0.05). There was no significant difference in Baird-Jackson score and AOFAS ankle and hindfoot score between the two groups at 3 months and 1 year after operation ( P>0.05). At the last follow-up, there was no ankle stiffness, neurovascular injury, deep vein thrombosis, infection or breakage of internal fixation in the two groups. Conclusion:The treatment of distal tibial proximal ankle fractures with retrograde intramedullary nail fixation has satisfactory reduction quality, good postoperative function recovery, and is helpful for early postoperative rehabilitation.

Objective To discover new-structure active molecules in order to provide candidate compounds for anti-radiation drug research.Methods Conformational fixation and functional group conversion strategies were used to modify the structure of Ex-RAD before substituted 2H-benzopyran-3-formylaniline compounds were designed and synthesized.The anti-radiation activities of the synthesized compounds were screened via irradiated cell survival models and the cytotoxicity of the active compounds was examined.Western blotting assay was used to investigate the effects of the optimal compound on the expressions of apoptosis related proteins in irradiated cells.The anti-radiation activity of the optimal compound was evaluated through irradiated mice models.Results Twenty-one target compounds were synthesized,eight of which were found to significantly improve the survival of irradiated cells.Four compounds were selected for re-screening and cytotoxicity evaluation.Compound D19 was determined as the optimal compound that could affect the expressions of apoptosis related proteins in irradiated AHH-1 cells by Western blotting assay.Compared with the radiation group,the 30-day survival rate of D19 treated mice irradiated with 8.6 Gy of whole-body radiation increased by 70%.D19 showed protective effect on the blood system of non-lethal dose irradiated mice.Conclusion The novel compound D19 has shown strong anti-radiation activity and deserves more research.

Objective:To investigate the clinical efficacy of distal tibiofibular screw fixation combined with ligament repair for the treatment of ankle fracture accompanied with distal tibiofibular syndesmosis injuries.Methods:A retrospective cohort analysis was made on clinical data of 72 patients with ankle fracture accompanied with distal tibiofibular syndesmosis injuries admitted to 909th Hospital of Joint Service Support Force of PLA from September 2017 to September 2020, including 38 males and 34 females, aged 19-65 years [(42.5±12.2)years]. The fracture was type B in 30 patients, type C 1 in 29 and type C2 in 13 according to Danis-Weber classification. A total of 36 patients were treated by distal tibiofibular screw fixation combined with ligament repair (fixation+repair group) and 24 patients by distal tibiofibular screw fixation (fixation group). Operation time, intraoperative blood loss and hospital stay were recorded. Visual analogue scale (VAS), American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score and ankle range of motion (ROM) were determined at 1, 3 months postoperatively and at the final follow-up. Complications were documented. Results:All patients were followed up for 12-22 months [(15.9±2.2)months]. There were no significant differences in operation time, intraoperative blood loss and hospital stay between the two groups (all P>0.05). VAS in fixation+repair group was (3.1±1.0)points and (2.1±0.6)points at 1, 3 months postoperatively, significantly lower than (3.9±0.8)points and (2.6±0.8)points in fixation group (all P<0.05), but the score showed no significant difference between the two groups at the final follow-up ( P>0.05). AOFAS score in fixation+repair group was (64.7±4.0)points, (73.2±3.4)points and (87.2±3.4)points at 1, 3 months postoperatively and at the final follow-up, significantly higher than (60.1±4.9)points, (70.2±1.9)points and (84.1±2.6)points in fixation group (all P<0.05). There was no significant difference in the ROM between the two groups at 1 month postoperatively ( P>0.05), but the ROM at 3 months postoperatively and at the final follow-up in fixation+repair group [(44.4±2.9)° and (52.3±2.5)°, respectively] was significantly higher than that in fixation group [(41.4±2.7)° and (50.1±2.7)°, respectively] (all P<0.05). There was 1 patient with internal fixation loosening in fixation+repair group, with the incidence of complications of 3% (1/36). While the incidence of complications was significantly lhigher in fixation group [17%(6/36)], including 2 patients with re-separation of distal tibiofibular syndesmosis, 2 with internal fixation loosening and 2 with internal fixation breakage ( P<0.05). Conclusion:Compared with distal tibiofibular screw fixation, distal tibiofibular screw fixation combined with ligament repair for the treatment of ankle fracture accompanied with distal tibiofibular syndesmosis injuries is effective to early relieve ankle pain, improve ankle function and ROM, and reduce occurrence of complications.