RÉSUMÉ
BACKGROUND:Schwann cells are important celllines in the process of repairing peripheral nerve injury, and human amniotic homogenate supernatant is shown to secrete a variety of cytokines, which could promote the proliferation of Schwann cells. OBJECTIVE:To investigate the effect of different concentrations of human amniotic homogenate supernatant on the proliferation of rat Schwann cell96. METHODS:Schwann cell96 was cultured with high-glucose DMEM containing 20%fetal bovine serum, and the second generation of Schwann cell96 was applied for experiments. The cultured cells were divided into five groups according to different volume fractions of human amniotic homogenate supernatant (0%, 10%, 15%, 20%, 25%) in the medium. RESULTS AND CONCLUSION:The total protein concentration of human amniotic homogenate supernatant was 675μg/mL, in which the concentration of epidermal growth factor, basic fibroblast growth factor and vascular endothelial growth factor were respectively (470.625±2.546), (4.121±0.026) and (0.172±0.002) ng/L. At 1-7 days, the cellproliferation rate of the 10%and 15%concentration groups was greater than that in 20%and 25%concentration groups (P0.05). Low concentrations (10%, 15%) of human amniotic homogenate supernatant promote the proliferation of Schwann cell96, while high concentrations (20%, 25%) of human amniotic homogenate supernatant inhibit cellproliferation.
RÉSUMÉ
Objective:To analyse the drug resistance of Stenotrophomonas maltophilia(Sm) for rational application of antibiotics in clinics. Methods:Antimicrobial susceptibility tests were processed by K-B method, metallo-?-lactamases (MBLs) were screened by synergic method, and extended-spectrum ?-lactamases (ESBL) were detected by double disk synergy test. Results:42 Sm strains were completely resistant to imipenem, highly resistant to cefotaxime (CTX), amikacin (AMK), aztreonam (ATM) and piperacillin-tazobactam (TZP) (the resistance rates were 92%,83%,78% and 64%, respectively). They showed low resistance rates to sulfamethoxazole/trimethoprim(SMZ/TMP), cefoperazone/sulbactam(CFS), ciprofloxacin (CIP) and ticarcillin/clavulanate (TIM)(26%,16%,12% and 9%, respectively). There were 71.43% strains of Sm producing ESBL, 80.95% producing MBL, and 57.14% producing both ESBL and MBL. Conclusion:There are many kinds of mechanism contributing to the drug resistance of Sm, to which more attention should be paid by clinicians.