BACKGROUND:Some studies have shown that the double-bundle posterior cruciate ligament reconstruction is not superior to the single-bundle posterior cruciate ligament reconstruction, and stil has some deficiencies difficult to overcome. Which is better, double-bundle reconstruction or single-bundle reconstruction? There is no uniform conclusion. OBJECTIVE:To perform a prospective cohort study on the clinical efficacy and safety of autologous single- and double-bundle posterior cruciate ligament reconstruction. METHODS:Totaly 81 patients with posterior cruciate ligament injury were randomly divided into single-bundle reconstruction group (n=41) and double-bundle reconstruction group (n=40). The knee stability, Lysholm score, Tegner score, hospital stay, operation time, fever days and number of puncture cases were compared between the two groups before and 24 months after reconstruction. RESULTS AND CONCLUSION:Compared with the single-bundle reconstruction group, the knee stability was significantly worse in the double-bundle reconstruction group (F=4.362,P=0.000); the operation time, hospital stay and number of puncture cases were also higher in the double-bundle reconstruction group (P < 0.05). At 24 months after reconstruction, the Lysholm and Tegner scores were both increased significantly in the two groups (P < 0.05), but there was no difference between the two groups (P > 0.05). These findings indicate that both single- and double-bundle reconstruction under arthroscopy is safe and effective treatment for posterior cruciate ligament injury, but the double-bundle reconstruction is not recommended as the preferred surgical procedure because of longer time and larger trauma.

5-Flucytosine (5-FC) could be changed to 5-fluorouracil (5-FU) by cytosine deaminase (CD), the latter is able to kill cancer cells. However, there is no efficient method to deliver the CD gene into the tumor cells, which hampers the application of the suicide gene system. In this experiment, for the first time, the NDV has been utilized as a vector to deliver the CD gene into the cancer cells, the virus can infect the cancer cells specifically, replicate and assemble, while the cytosine deaminase is expressed. Then the CD converts the prodrug 5-FC into 5-FU to achieve the purpose of inhibiting tumor. Firstly, the whole genome of E. coli JM109 was extracted, and the CD gene was obtained by cloning method. Then the CD and IRES-EGFP were ligated into the pEE12.4 expression vector to become a recombinant pEE12.4IE-CD eukaryotic expression plasmid. The human liver cancer cells were transfected with the plasmid. The cells were treated with different concentrations of 5-FC, MTT method was used to determine the killing effect of CD/5-FC system on the human liver cancer cells. The cell deaths were 18.07%, 42.98% and 62.20% respectively when the concentrations of prodrug were at 10, 20 and 30 mmol x L(-1). In 5-FC acute toxicity experiment, Kunming mice were injected with different concentrations of 5-FC at intervals of 1:0.5. The LD50 of 5-FC through iv injection was determined by improved Karber's method, the LD50 was 507 mg x kg(-1) and the 95% confidence limit was 374-695 mg x kg(-1). According to the maximum LD0 dose of the LD50, the maximum safe dose was 200 mg x kg(-1). Body weight and clinic symptoms of the experimental animals were observed. These results laid the foundation to verify the antitumor effect and safety of CD/5-FC system in animal models. The CD gene was ligated into the NDV (rClone30) carrier, then the tumor-bearing animal was established to perform the tumor inhibiting experiment. The result showed that the recombinant rClone30-CD/5-FC system has a high antitumor activity in vivo. To summarize, CD gene has been cloned and its bioactivity has been confirmed in the mammalian cells. It is the first time in this study to utilize the recombinant NDV to deliver the CD gene into the tumor cells; our result proves the rClone30-CD/5-FC system is a potential method for cancer therapy.

Objective To develop the measuring system used for the parameters of onboard oxygen supply equipment in the hypobaric chamber. Methods The programmable controller was applied to acquisition, processing and analysis of the data from the sensor. The host computer was used to accomplish control and information display. Results The system could display the parameters through digital, simulating meters, and recording curve. The numerical value in the recording curve was marked by the date and time. All data were saved in the computer for futural analysis and procession. Conclusion The measurement system of oxygen supply parameters can satisfy the desired requirements for the performance and precision.

Objective:To compare postoperative analgesic effect of flurbiprofen axetil and parecoxib sodium in patients with humeral shaft fracture in painless ward.Methods:All of 200 hospitalized humeral fractures patients were retrospectively studied in the painless ward of the Forth Medical Center of PLA General Hospital from January 2017 to September 2019 , the clinical effects of flurbiprofen axetil and parecoxib were compared.Results:Postoperative visual analogue scale (VAS) scores after 3 d of two groups of patients were significantly lower, compared with preoperative results: (4.26±0.96) scores vs. (6.09±1.38) scores, (4.04±1.19) scores vs. (6.04±1.11) scores, and the differences were statistical significantly ( P<0.01). Postoperative VAS score after 3 d of two groups had no statistical significance ( P>0.05). Two groups had different degree of adverse reactions after operation, and flurbiprofen axetil group had singnificant gastrointestinal adverse reaction: 22 patients vs. 3 patients( P<0.05). The number of patients in the parecoxib group were more than that in the flubiprofen axetil group without troubled sleep: 20 patients vs. 8 patients. Two groups of patients were satisfied with the pain care during hospitalization. Conclusions:Two analgestic drugs can obtain obvious analgesic effect in the treatment of bones surgery. The side effects and sleep disturbance in the flurbiprofen axetil group are higher than those in the parecoxib group. Good pain control can improve patients satisfaction with pain care.

Objective To compare the ear baric function between 4000m altitude chamber test with inhaling air and 6900m altitude chamber test with inhaling pure oxygen.Methods Eleven healthy male volunteers attended two tests as two groups by self-comparison. As the air group the volunteers inhaled air at 4000m, while as the pure oxygen group they inhaled pure oxygen at 6900m altitude, and the time interval between the two tests was more than two weeks. During the test, the volunteers breathed air or pure oxygen at random for 1h, and then were exposed at a speed of 20m/s to the target altitude for 5min. Hereafter they were sent back to the ground at the same speed. The changes of subjective symptoms, degree of tympanic congestion, acoustic immitance index and pure-tone auditory threshold were recorded before and after the test. The acoustic impedance index and pure-tone threshold were statistically analyzed.ResultsFour volunteers (4 ears) in air group and 7 volunteers (7 ears) in pure oxygen group reported ear pain in altitude chamber exposures, respectively. The pain-triggering altitude was higher in the pure oxygen group. Immediately after tests, there were 3 (3 ears) and 5 volunteers (5 ears) with Ⅲ degree congestion of the tympanic membrane in the two groups respectively. Four volunteers (6 ears) developed gradually aggravated hemorrhages after altitude exposure. And the tympanic membrane congestion difference between groups was statistically significant at 3 and 24h after tests (P<0.01). The type A tympanogram appeared in 11 (15 ears) and 11 (14 ears) volunteers respectively immediately after tests. The increase of static compliance value was significantly greater in pure oxygen group than in air group immediately after tests (P<0.05), the decrease of middle ear pressure was more significant in pure oxygen group than in air group at 3 and 24h after tests (P<0.05). Both the two altitude exposure tests resulted in eustachian tube dysfunction. At 3 and 24h after the tests, the increase of individual frequency pure-tone threshold was significantly higher in pure oxygen group than in air group (P<0.05).Conclusion Breathing pure oxygen and lifting height could increase the screening degree of ear baric function test in hypobaric chamber, and have greater influence on degree of tympanic congestion, acoustic immittance and pure-tone auditory threshold in 24 hours.

To investigate the cell-killing effect and its possible mechanism of rClone30-hDR5 in combination with TRAIL on human hepatic carcinoma (HCC) cell line, first of all, recombinant plasmid pee12.4-hDR5 was introduced into HepG2 cells by liposome transfection. After five rounds of screening by flow cytometry, HepG2 cells expressing high levels of DR5 on cell surface were isolated. The cytotoxicity of TRAIL to selected cells was higher than that of TRAIL to HepG2 cells by MTT method (P < 0.01). The result suggested that the cloned hDR5 gene had biological activity. MTT assay showed that, rClone30- hDR5 in combination with TRAIL more efficiently inhibited the tumor growth of HepG2 cells compared to rClone30-hDR5 or TRAIL in vitro. The results of Annexin V-FITC/PI staining and Quantitative Real-time PCR indicated that rClone30-hDR5 in combination with TRAIL significantly increased the mRNA levels of caspase 3 and caspase 8, and induced the apoptosis of tumor cells. HepG2 cells were infected with rClone30-hDR5 or rClone30 at MOI of 1. The expression of hDR5 on tumor surface increased significantly by rClone30-hDR5 compared to that by rClone30, which contributed to the sensitivity to TRAIL. In conclusion, rClone30-hDR5 in combination with TRAIL has potential application value in cancer treatment.

In order to enhance the antitumor efficacy of recombinant Newcastle disease virus, rNDV-IL15 was rescued in this study. Recombinant plasmid prNDV-IL15 was constructed, and BHK21 cells were transfected with the recombinant plasmid. Finally, the recombinant Newcastle disease virus rNDV-IL15 was successfully rescued. The growth curves of these two recombinant viruses were determined. Murine melanoma B16F10 cells were infected with rNDV-IL15 at MOI of 0.1, and the expression level of IL15 in the supernatant was detected by ELISA. The antitumor efficacy of rNDV-IL15 and rNDV was compared in vitro and in vivo. Results showed that prNDV-IL15 was constructed and recombinant virus rNDV-IL15 was successfully rescued. The growth curve of rNDV-IL15 showed that the growth of rNDV-IL15 had not been changed after insertion of IL15 gene. Results showed that there was high level of IL15 expression in the supernatant of rNDV-IL5-infected B16F10 cells (1 044.3 +/- 27.7 ng x mL(-1)). rNDV-IL15 and rNDV significantly inhibited the growth of B16F10 cells in vitro in a time-dependent manner. However, there was no significant difference between them. In animal experiments, rNDV-IL15 efficiently suppressed tumor growth in vivo when compared with rNDV, and the difference was statistically significant. The results suggested that rNDV-IL15 is a more effective antitumor agent.

Objective To study the methods and clinical effect of lateral less invasive stabilization system(LISS)plate combined with medial buttress plate in distal femoral fractures patients with comminuted medial cortex.Methods The clinical data of 25 distal femoral fractures patients with comminuted medial cortex from June 2014 to December 2015 were retrospectively analyzed, and all patients were treated with lateral LISS plate combined with medial buttress plate. According to the AO fracture classification,A3 type was in 10 cases,C2 type was in 9 cases,and C3 type was in 6 cases.The knee joint function at 3,6 and 12 months after operation was evaluated according to American hospital for special surgery (HSS) knee joint function score, and the clinical effect was evaluated 12 months after operation.Results The patients were followed up 18-36 months,with an average of 23.4 months.The operation time was (80 ± 22) min, intraoperative bleeding was (395 ± 56) ml, and the average hospitalization time after operation was 5.6 d.All patients got bone union,and the bone union time was 16-30 months,with an average of 18.7 months.All patients had no incision infection,no fracture and delayed union.The HSS knee joint function scores at 3,6 and 12 months were(84.3 ± 7.8),(89.3 ± 7.2) and(97.9 ± 4.3)scores.The incidence of complications was 24%(6/25),and the excellent and good rate was 84%(21/25).Patients felt satisfied.Conclusions The clinical effect of lateral LISS plate combined with medial buttress plate in distal femoral fractures patients with comminuted medial cortex is good.

Traumatic rib fractures are the most common injury in thoracic trauma. Previously，the patients with traumatic rib fractures were mostly treated non-surgically，of which 50%，especially those combined with flail chest presented chronic pain or chest wall deformities and over 30% had long-term disabilities，being unable to retain a full-time job. In the past two decades，thanks to the development of internal fixation material technology，the surgical treatment of rib fractures has achieved good outcomes. However，there are still some problems in clinical treatment，including inconsistency in surgical treatment and quality control in medical services. The current consensuses on the management of regional traumatic rib fractures published at home and abroad mainly focus on the guidance of the overall treatment decisions and plans，and relevant clinical guidelines abroad lacks progress in surgical treatment of rib fractures in recent years. Therefore，the Chinese Society of Traumatology affiliated to Chinese Medical Association and Chinese College of Trauma Surgeons affiliated to Chinese Medical Doctor Association，in conjunction with national multidisciplinary experts，formulate the Chinese Consensus for Surgical Treatment of Traumatic Rib Fractures（2021）following the principle of evidence-based medicine，scientific nature and practicality. This expert consensus puts forward some clear，applicable，and graded recommendations from aspects of preoperative imaging evaluation，surgical indications，timing of surgery，surgical methods，rib fracture sites for surgical fixation，internal fixation methods and material selections，treatment of combined injuries in rib fractures，in order to provide references for surgical treatment of traumatic rib fractures.