Objective To evaluate the efficacy and safety of parent-controlled analgesia for postoperative pain management in pediatric patients. Methods Five hundred and seven ASA Ⅰ or Ⅱ pediatric patients aged 10 months to 8 yr, weighting 8.5-34.0 kg, undergoing lower limb operations performed under general anesthesia combined with caudal block were assigned into 2 age groups: group PCIA-P ( < 6 yr, n = 308) and group PCIA ( ≥6yr, n = 199). Anesthesia was induced with intravenous midazolam 1 mg/kg, ketamine 2 mg/kg and propofol 2 mg/kg. Laryngeal mask airway (LMA) was introduced or the patients were intubated. After induction, caudal block was performed with 0.25% bupivacaine 2.5 mg/kg with adrenaline 1:400 000. The patients received PCA with morphine after operation. The PCA pump was controlled by parent in group PCIA-P and by patient in group PCIA. The PCA regimen included a background infusion of morphine at a rate of 15μg~(-1)·kg~(-1)·h, a bolus of 15μg/kg and a 10 min lockout interval. The vital signs, pain score, sedation score, number of attempts, morphine dosage and side effects were recorded. Results The two groups were comparable with respect to the rate of satisfactory analgesia, level of sedation, number of attempts, morphine dosage and side effects. The rates of satisfactory analgesia were 72.7% and 80.2% in group PCIA-P vs 77.9% and 78.9% in group PCIA at 24 and 48 h after operation respectively ( P > 0.05) . Conclusion Parent-controlled analgesia could be used safely and effectively in children after orthopedic surgery.

Objective To establish the pharmacodynamic model of sevoflurane with bispectral index (BIS) as the effective index in pediatric patients.Methods Thirteen ASA physical status Ⅰ or Ⅱ pediatric patients,aged 4-9 yr,weighing 12-39 kg,undergoing non-cardiac surgery,were selected in the study.The pediatric patients sequentially inhaled 1％,5 ％ and 1％ sevoflurane via a face mask and each concentration was inhaled for 15 min.BIS value,HR,BP and SpO2 were automatically recorded every 10 s.Based on nonlinear mixed effect modeling,the population pharmacodynamic model of sevoflurane was established using NONMEM software.The effect of age on the pharmacodynamic parameters was evaluated using a stepwise forward addition then backward elimination modeling approach.The standard for model improvement was defined as a decrease in the value of the objective function by more than 3.84.Results Twelve pediatric patients,aged 4.0-8.5 yr,weighing 12.8-38.0 kg,with body height of 92-135 cm,were enrolled in this study and the data which were enrolled comprised 2964 effective concentration-time-BIS points.The model was not improved significantly with any covariates (age,body height,and body weight) introduced (P ＞ 0.05).The estimated parameters of the final pharmacodynamic model of sevoflurane were as follows:ke0 =O.516/min ; EC50 (BIS50) =2.11％ ; γ =2.46 ; E0 =74.6 ; EMAx =11.2.Conclusion The pharmacodynamic model of sevoflurane is successfully established with BIS as the effective index in pediatric patients,and the analysis for each parameter of the model indicates that the sensitivity to sevoflurane is lower,but the blood-brain equilibration time of the drug is shorter and the onset and recovery are faster in children than in adults.

Objective:To investigate the effect of diallyl trisulfide (DATS) on the expression of folate receptor α (FRα) in human gastric cancer cells and the related regulatory mechanism.Methods:Human gastric cancer cell lines BGC823 and AGS were selected, BGC823 cells were treated with 10, 20, 40, 80 μmol/L DATS for 48 hours, and AGS cells were treated with 5, 10, 20, 40 μmol/L DATS for 48 hours. Cells treated with 6 μmol/L histone deacetylase (HDAC) inhibitor trichostatin A (TSA) were used as positive control for epigenetic study, and cells untreated with DATS were used as negative control. The apoptosis of gastric cancer cells induced by DATS was detected by flow cytometry. After BGC823 and AGS cells were treated by DATS for 48 hours, they were replaced with DATS-free cell culture medium and cultured for different time to detect the changes in FRα protein expression. BGC823 and AGS cells were treated with 6 μmol/L TSA or 40 μmol/L DATS. The protein expression levels of FRα, HDAC1 and HDAC2, and histone H3 lysine 9 acetylation (H3K9ac) and histone H4 lysine 5 acetylation (H4K5ac) were detected by Western blot. BGC823 cells were inoculated into BALB/c nude mice to establish tumor bearing model. The nude mice in DATS group were injected intraperitoneally with 10 mg/kg DATS for 16 days, and then the protein in tumor-bearing tissues was extracted to detect the expression of target protein, while the control group was injected with equal dose of 0.9% NaCl solution.Results:The expressions of FRα protein in BGC823 and AGS cells were up-regulated in a dose-dependent way after gradient concentrations of DATS treatment ( F = 65.68, P < 0.01; F = 26.65, P < 0.01). After changing the cell culture medium without DATS, the expressions of FRα protein in BGC823 and AGS cells gradually decreased and returned to the initial levels ( F = 74.57, P < 0.01; F = 30.92, P < 0.01). With the increase of DATS concentration, the apoptosis rates of BGC823 and AGS cells increased ( F = 32.95, P < 0.01; F = 38.97, P < 0.01). After TSA treatment, FRα protein expressions in BGC823 and AGS cells were up-regulated by 4.5 times ( t = -12.62, P < 0.01) and 3.6 times ( t = -10.00, P < 0.01). After 40 μmol/L and 20 μmol/L DATS treatment, the expression level of FRα protein in BGC823 and AGS cells was up-regulated (both P < 0.01), the expressions of HDAC1 and HDAC2 were inhibited (all P < 0.01), and the levels of H3K9ac and H4K5ac acetylation modification increased (all P < 0.01). The results of tumor-bearing nude mice experiment showed that the volume of transplanted tumor in DATS group was smaller than that in the control group [(214±39) mm 3 vs. (577±98) mm 3], and the difference was statistically significant ( t = 4.86, P < 0.01). Compared with the control group, FRα protein expression in the transplanted tumor tissues of DATS group was up-regulated about 2 times ( t = -5.29, P < 0.01), and the expression levels of HDAC1 and HDAC2 proteins were down-regulated ( t = 9.36, P < 0.01; t = 9.88, P < 0.01). Conclusions:DATS up-regulates the expression of FRα protein in human gastric cancer BGC823 and AGS cells in a dose-dependent and reversible manner. The mechanism may be related to the effect of DATS on histone acetylation modification in tumor cells.