Objective　To obtain staphylococcal enterotoxin B (SEB) mutant with normal antigenicity but low toxicity. Methods　Using PCR technique, normal SEB (SEB-N) gene which was amplified from S. aureus S6B. SEB mutant gene (SEB-M) was prepared from the same strain, but one nucleotide in SEB gene was changed from asparagine (N23) to serine (S23). SEB-N and SEB-M were cloned into procaryotic expression vector pTrc99A then and transferred into E. coli JM109. SEB-N and SEB-M which were cloned into plasmid were sequenced directly by dideoxynucleotide method. The crude expressed proteins were identified by double agar immunodiffusion. The level of IL-2 in supernatants of mouse splenocytes stimulated by crude expressed proteins was determined by ELISA. Results　SEB-N and SEB-M were obtained through PCR. The sequence of SEB-N was changed with non site-directed mutagenesis, threonine at the residue 150 of SEB-N was replaced with alanine (ACT→GCT, T150A). As being expected, at the residue 23 of SEB-M, serine substituted for asparagine (AAT→AGT, N23S) with site-directed mutagenesis. Double agar immunodiffusion showed obvious precipitin line with anti-SEB by both crude SEB-N and SEB-M mutant proteins could produce, but not by non-recombinant strain. ELISA demonstrated that the level of IL-2 in supernatant of mouse splenocytes stimulated by natural SEB protein (containing equal amount of JM109P crude protein) was 40 times as much as that stimulated by SEB-M and 12.5 times as much as that stimulated by SEB-N. Conclusions　We obtained two recombinant strains which produced T150A and N23S mutant SEB protein. The mutant proteins showed binding ability to anti-SEB as the normal protein. However, their biological activity as superantigen decreased sharply. We consider that it is promising for further study of molecular adjuvant or superantigen vaccine.

The anti proliferation effects of four different concentrations of tea polyphenols on PG cell lines were determined with MTT assay. Laser scanning confocal mircroscopy and flow cytometry techniques were used to determine the changes in intracellular calcium concentration, GJIC, Cx43 expression, and cell cycle distribution after treatment with tea polyphenols. The results showed that four different concentrations dose dependently inhibited the proliferation of PG cell lines. It caused a decline in the proportion of cells in S and G2/M phase, blocked the cell cycle progression in G0/G1 phase, and reduced the proliferation index of PG cell lines. Compared with control group, intracellular calcium concentration, GJIC and Cx43 expression were gradually increased ascended with an increase in tea polyphenols concentration. The results suggested that tea polyphenol could inhibit growth of PG cell lines. The mechanism of anti tumor is associated with an up regulation of GJIC of PG cell line.

Objective To develop an all-in-one multifunctional thoracolumbar fixation rescue vest for land and water rescue of thoracolumbar injury and investigate its application effect.Methods According to the thoracolumbar physiological curve,type Ⅰ thoracolumbar fixation rescue vest with keel and inflatable airbag and type Ⅱ thoracolumbar fixation rescue vest with additional lifesaving balloon and inflatable cylinder were developed using thermoplastic polyurethane (TPU)-nylon composites and polycarbonate (PC) as the main materials.Clinical application of type Ⅰ thoracolumbar fixation rescue vest in 532 cases of thoracolumbar injury was discussed.Type Ⅱ thoracolumbar fixation rescue vest were tested at marine rescue and related parameters measured were automatic inflation time,buoyancy force,floating time,floating condition and victims' face orientation.Clinical outcome was quantified by the MacNab standard,and VAS for pain was recorded.Results According to the MacNab standard,excellent outcome was achieved for all cases.VAS improved from 8.2 points to 2 points after the bracing was applied,showing 100％ improvements.The brace into the water showed automatic inflation time of 3-5 seconds and maximum buoyancy force of 100 kg,and ensured a 90 kg dummy of floating over 96 hours.At marine rescue,the wounded in braced condition showed face upward with 24-hour buoyancy loss ≤5％ and freedom of movement.Conclusions The multifunctional thoracolumbar fixation rescue vest provides dual immobilization and ensures marine rescue for its automatic inflation device.This invention provides the feasibility to remove,transport and evacuate the thoracolumbar fracture patients in cabin.

Objective To explore whether the Chinese medicine Guben Yiliu III can improve the effect of gemcit -abine on human pancreatic cancer xenograft in nude mice . Methods Nude mice with transplanted human pancreatic cancer were divided randomly into 4 groups: control group, gemcitabine treatment group , combined ( Guben Yiliu III +gemcitabine) group, and Guben Yiliu III group, 10 mice in each group.The gemcitabine group and combined group were treated with gemcitabine from the 8th day after transplantation in a dose of 100 mg/kg by i.p.injection, twice a week. Guben Yiliu III and combined groups were given the aqueous solution of Guben Yiliu III granules p .o.since the 8th day af-ter transplantation .Result The inhibition rate of transplanted tumor in the three treatment groups were 48.9% in the gemcitabine group , 68.9%in the combined group , and 28.0%in the Guben Yiliu III group .The combined group showed a significantly higher inhibition rate than the gemcitabine group (P<0.05).The gemcitabine group, combined group and Guben Yiliu III group showed a significantly slower growth rate than the control group .However, the combined treatment group showed a pronounced side effect and body weight loss than the other 3 groups .Conclusions The Chinese medicine Guben Yiliu III can improve the inhibitory effect of gemcitabine on nude mice with human pancreatic cancer xenograft in the auxilla of nude mice .

The purified elementary bodies of C. pneumoniae TW-183 were used for immunization of male BALB/c mice, the spleen cells of these mice were fused with SP2/0 cells and the hybrid cells were cloned by limiting dilution. One clone that secreted the C. pneumoniae monoclonal antibody (Cpn-McAb) stably was obtained finally. The Cpn-McAb belonged to IgG2b class and anti-Cpn-MOMP; the outcome of micro-immunofluorescence showed its weak cross reaction with the C. psittaci elementary body but it has no cross reaction with C. trachoma elementary body. It has the same speciality of the imported Cpn-McAb. For the evaluation of Cpn-McAb, the peripheral blood mononuclear cell specimens of 454 patients were detected by self-made Cpn-McAb and imported Cpn-McAb at the same time. The positive rates of Cpn-antigen were 53.3% for self-made Cpn-McAb and 52.6% for imported Cpn-McAb,showing high concordance between them (Kappa=0.714). The results showed that self-made Cpn-McAb has almost the same high specificity and sensitivity as imported Cpn-McAb, so the self-made Cpn-McAb may replace imported Cpn-McAb to detect Cpn specific antigen and be helpful to diagnosing and treating the clinical diseases associated with Cpn infection.
Animals ; Antibodies, Bacterial ; immunology ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Antibody Specificity ; Chlamydia Infections ; diagnosis ; microbiology ; Chlamydophila pneumoniae ; immunology ; Hybridomas ; secretion ; Male ; Mice ; Mice, Inbred BALB C

Objective: To establish and verify the validity of a finite element(FE) model of fragment injury in swine mandibular composite tissue. Methods: Swine facial composite tissue digital information was obtained by 3D CT,the 3D model and the cylinder fragment with the diameter and height of 5. 5 mm were reconstructed and designed in mimics15. 0. The right mandibular angle region was impacted by the fragment with velocities in finite element analysis software. A two stage light gas gun was used to launch the same shape 30CrMnSi alloy fragment with the speed of 831,1 120 and 1 536 m/s respectively to impact swine mandibular angle area. The actual damage area and acceleration at jaw were measured and compared with the digital simulation results. Results: Compared with the data of digital simulation the fragment with the speed of 831,1 120 and 1 536 m/s resulted in the larger mandibular damage area of entry in the in vivo experiment by 13. 4％,23. 6％ and 22. 3％; that of exit by 18. 7％,23. 0％ and 26. 5％; the smallar accelaration peak by 16. 7％,15. 3％ and 14. 6％,respectively. Conclusion: A digital model of the swine mandible composite tissue fragment injury model is established. The simulation results of the FE model are consistent similar to those of the in vivo test data.

Objective    To analyze the outcomes of surgical repair for mixed total anomalous pulmonary venous connection (TAPVC). Methods    Between 2006 and 2018, a total of 51 patients with mixed TAPVC underwent surgery in our hospital. Patients with such associated anomalies as single ventricle and tetralogy of Fallot were excluded. There were 35 males and 16 females with a median age of 102.0 (59.0, 181.0) days and a median weight of 5.0 (4.1, 6.4) kg. Patients were divided into three categories based on the anatomy: "3+1" pattern (n=38, three pulmonary veins drained at one site, and the other drained at the opposite site); "2+2" pattern (n=9, the pulmonary veins from each lung joined to form a confluence and drained at separate sites); bizarre pattern (n=4, the anatomy could not be classified into the above two patterns). Results    There was no in-hospital death. The median follow-up was 41.0 (18.0, 86.5) months. Postoperative pulmonary venous obstruction occurred in 10 patients. Kaplan-Meier survival curves showed no statistically significant difference in postoperative pulmonary venous obstruction among the three groups (P=0.239). Cox risk regression showed that preoperative pulmonary venous obstruction was significantly associated with postoperative pulmonary venous obstruction (P=0.024). Conclusion    Mixed TAPVC has various anatomic morphologies and requires individualized surgery.

Objective    To compare the outcomes of sutureless technique and conventional technique in the surgical repair for infracardiac total anomalous pulmonary venous connection (TAPVC). Methods    The clinical data of 46 consecutive patients with infracardiac TAPVC undergoing surgical repair in our hospital between June 2014 and April 2019 were retrospectively analyzed. Patients with combined congenital cardiac anomalies such as single ventricle and tetralogy of Fallot were excluded. Patients were divided into a conventional technique group and a sutureless technique group according to the surgical techniques. There were 35 patients in the conventional technique group, including 28 males (80.0%) and 7 females (20.0%) with a median age of 21 (8, 42) d and a median weight of 3.6 (3.0, 4.0) kg. There were 11 patients in the sutureless technique group, including 8 males (72.7%) and 3 females (27.3%) with a median age of 14 (6, 22) d and a median weight of 3.5 (2.9, 3.6) kg. The curative effect of the two groups was compared. Results    There were 5 deaths (10.9%) in the conventional technique group, including 4 in-hospital deaths (8.7%) and 1 late death (2.2%). Overall mortality of the conventional technique group (14.3%, 5/35) was higher than that of the sutureless technique group (0.0%, 0/11), although the difference was not statistically significant (P=0.317). Cox regression analysis showed that sex (P=0.042), age at repair (P=0.028), cardiopulmonary bypass time (P=0.007), aortic cross-clamping time (P=0.018) and duration of ventilation (P=0.042) were risk factors for postoperative mortality. The median follow-up was 18.00 (5.00, 37.75) months. Postoperative pulmonary venous obstruction occurred in 22 patients of the conventional technique group, which was significantly more than that of the sutureless technique group (P=0.000). Conclusion    For infracardiac TAPVC, sutureless technique can reduce the incidence of postoperative pulmonary venous obstruction compared with conventional technique.