The student majoring in Medical Biological Technique will be mainly engaged in the practical work of biological technique industry after graduation in the future.In order to bind the theories on the practical biological techniques in designs of contents and roundly improve students' practical ability in classes as well as enriching the communication among students,our college offers an immunologic techniques experiment classes with 36 hours per semester,which has also undergone a reasonable project teaching innovation. This proved to result in a satisfactory outcome in improving the students' practical a

Objective Discussion leukoreduction of red blood cells suspended in two different storage bag placement and he-molysis rate impact on the supernatant free hemoglobin (FHb),to ensure the clinical transfusion is safe and effective.Meth-ods Selected 20 donors to sample 400 ml whole blood per person to make leukodepleted red blood cells,which were evenly divided into 10 bags.The 10 bags were randomly divided into two groups,one to the upright position,one group of horizon-tal.The two groups were stored under the same conditions.Respectively,in the 7,14,21,28,35 day,randomly removed one storage bag from each group,FHb and red blood cell hemolysis rate were measured and analyzed statistically.Results FHb and hemolysis rate results stored in the first 21 days of testing,uprightgroup were (217.310±48.477)mg/L and (0.250± 0.056)%,respectively horizontal group (173.972±39.027)mg/L and (0.189±0.045)%,the results set upright than hori-zontal group,the results were statistically(t=3.114,P =0.003<0.05 and t=3.798,P =0.001<0.05),the difference was statistically significant.Conclusion In the blood storage period,storage bags can be placed horizontally to reduce the de-struction of red blood cells,blood storage is more favorable.

Objective: To explore the effects of BPA on the expression of N-cadherin, Vimentin and FSHR in rat Sertoli cells. Methods: Primary Sertoli cells collected from prepuberty rats (18-21 d) were cultured for 48 h, and then they were treated with 0, 30, 50, 70 μmol/L BPA respectively for 24 h. The methods of MTT, real-time quantitative PCR and Western blotting were utilized to measure the cell ability of Sertoli cells, the mRNA and protein expression levels of N-cadherin, Vimentin and FSHR respectively. Results: Compared with control, the cell abilities of Sertoli cells in 50 μmol/L BPA group and 70 μmol/L BPA group increased significantly (P<0.05) . The cell abilities of Sertoli cells decreased with the increases of exposure doses of BPA. Compared with control, the expression of N-cadherin mRNA only increased in 30 μmol/L BPA group (P<0.05) , the expression of Vimentin mRNA decreased significantly in all doses group of BPA (P<0.05) , the expression of FSHR mRNA increased in all doses group of BPA (P<0.05) . Compared with the control, the protein levels of N-cadherin increased significantly in 50 μmol/L BPA group (P<0.05) , the protein levels of Vimentin decreased significantly in all doses group of BPA (P<0.05) , the protein levels of FSHR decreased significantly in 50 μmol/L BPA group and 70 μmol/L BPA group (P<0.05) . Conclusion The mechanism of testicular toxicity from BPA might be the alterations of N-cadherin, Vimentin and FSHR by disturbing normal spermatogenesis.

Objective:To investigate the related factors that affect the timing and prognosis of early tracheostomy in patients with multiple rib fractures.Methods:A retrospective case series study was conducted on medical data of 222 patients with multiple rib fractures who underwent tracheostomy in Affiliated Hospital of Yangzhou University from February 2013 to October 2019，including 160 males and 66 females，with the age of 18 to 85 years ［（49.5 ± 16.3）years］. According to the practice management guidelines for tracheostomy timing and the use of propensity score matching technology，there were 118 patients with tracheostomy within 7 days of tracheal intubation （early group） and 104 patients with tracheostomy after 7 days of tracheal intubation （late group） before matching，and there were 87 patients in early group and 87 patients in late group after matching. Data were compared between groups including the gender，age，underlying disease，injury severity score （ISS），Glasgow coma score （GCS），number of fractured ribs，total number of rib fractures （NTRF），first rib fracture，flail chest，traumatic brain injury，combined injuries （spine，maxillofacial，sternum），acute respiratory distress syndrome （ARDS），volume fraction of pulmonary contusion（VPC），blood lactic acid （within 24 hours of admission），hemothorax，pneumothorax，mechanical ventilation time，duration of tracheostomy，time from tracheal intubation to incision，length of hospital stay，length of stay in ICU，closed thoracic drainage，number of fiberoptic bronchoscopy，multi-drug resistant bacteria infection，ventilator-associated pneumonia，antibiotic use time，duration of sedative and analgesic drugs used and 28-day mortality. The multivariate Logistic regression analysis was used to predict independent risk factors for early tracheostomy. The Pearson method was used to compare the relationship between multiple factors. The receiver operating characteristic （ROC） curve was used to predict indicators that affect the prognosis of patients with early tracheostomy，and calculate the best cut-off value. The Kaplan-Meier single factor and COX multivariate survival were used to analyze the relevant factors affecting the 28-day mortality of patients.Results:（1） In early group，the NTRF，ARDS and VPC were higher than those in late group，and the time from tracheal intubation to incision and 28-day mortality rate were lower than those in late group （ P < 0.05），while the two groups showed no significant differences in the gender，age，underlying diseases and ISS （ P > 0.05）. （2） The multivariate Logistic regression analysis showed that there was statistical significance in NTRF （ OR = 1.775，95% CI 1.439-2.188），ARDS（ OR = 3.740，95% CI 1.441-9.711），VPC （ OR = 1.087，95% CI 1.052-1.124） （ P < 0.05）； the Pearson method analysis showed a significant correlation between VPC and NTRF （ r = 0.369， P < 0.05） and a low degree of correlation between ARDS and VPC （ r = 0.179， P < 0.05），but there was no significant correlation between ARDS and NTRF （ r = 0.132， P > 0.05）. （3） The ROC curve analysis showed that the area under the curve （AUC） of the VPC and NTRF ［AUC = 0.832 （95% CI 0.770-0.893），AUC = 0.804 （95% CI 0.740-0.868）］ were significantly higher than those of the number of rib fractures ［AUC = 0.437（95% CI 0.352-0.523），GCS ［AUC = 0.519 （95% CI 0.432-0.605）］ and ISS ［AUC = 0.484 （95% CI 0.398-0.571）］ （ P < 0.05）. After calculating the Yorden index，the best cut-off value for VPC was 23.9，and the best cut-off value for NTRF was 8.5. （4） The Kaplan-Meier single factor and multivariate COX model survival analysis showed that the 28-day survival ratio of patients with early tracheostomy was significantly better than that of late tracheostomy （ P < 0.05）. Conclusions:The NTRF，ADRS and VPC are independent risk factors for the timing and prognosis of early tracheostomy. There is a significant correlation between VPC and NTRF. The VPC ≥ 23.9% and or NTRF ≥ 8.5 can be used to predict early tracheostomy in patients with multiple rib fractures. Early tracheostomy may benefit the 28-day survival of patients with multiple rib fractures.

Objective:To investigate the immune characteristics of SARS-CoV-2 membrane (M) protein, especially the possibility of inducing antibody-dependent enhancement effect (ADE).Methods:Full-length SARS-CoV-2 M protein was prepared by prokaryotic expression system and purified. BALB/c mice were immunized subcutaneously three times (on day 1, day 14 and day 21) by purified M protein. Serum samples were collected before immunization and after each immunization. The specificity of immune sera against M protein was identified by Western blot, and the antibody titers were detected by ELISA and neutralization test. In the presence of anti-M protein serum, the proliferation of SARS-CoV-2 in dendritic cells, nature killer cells, T and B cells was detected in vitro. Results:The immune sera from BALB/c mice immunized with purified full-length M protein of SARS-CoV-2 specifically recognized viral M protein. The titer of anti-whole virus antibody in immune sera was about 1∶400, but the antibody could not neutralize live virus. Moreover, the antibody could not help the virus to infect and proliferate in the various types of immune cells with Fc receptor (FcR).Conclusions:Non-neutralizing antibody induced by M protein could not cause ADE through FcR pathway.