There is evidence that onset time and potency of the non-depolarizing neuromuscular blocking agents are related. The relationship between onset time and the rate of recovery has been less well studied. In this experiment, the myodynamie response of adductor pollicis to single electric stimulation of wrist ulnar nerve, served as the parameter of neuromuscular blockade, and with the isolated forearm technique being used, the onset and offset times of vecuronium, pancuronium, mivacuronium or doxacurium were recorded in four adult healthy volunteers respectively. The results indicated that there was a positive correlation between onset and offset times (r=0.958, P

Objective: To study the effects ot intravenous 1％ procaine on cortex. Method: Ten patients,aged 29-59 years,for elective surgical operations,were observed the changes of spectral edge frequency(SEF), medium power frequency (MPF)and ? rate(?R)on power spectral analysis and bispectral index(Bl)on bispectral analysis during intravenous propofol 4 mg?kg~(-1)? h~(-1) purely for 15 min,intravenous combination of 1％ procaine 1mg?kg~(-1)?min~(-1) and propofol for 30 min, then intravenous propofol 4mg?kg~(-1)?h~(-1)purely for 15min. Result: SEF,MPF and BI values during combination stage were lower significantly (15.46?1.87Hz, 7.21?2.01Hz, 68.77?7.99 respectively)than the values during other two stages(stage 1 and stage 2 were 21.36?2.79Hz,11.55?2.62Hz,85.6?8.84 and 20.59?3.10Hz, 9.5?3.44Hz, 84.97?8.71 respectively, P

Objective To study the sedation efficacy of propofol combined with midazolam and /or fentanyl in fibreoptic choledochoscope. Methods Ninty outpatients were randomly divided into three groups. Group PF (n=31)was given fentanyl 0. 05 m.g plus propofol 1 mg/kg intravenously, group PM (n=29) midazolam 2 mg plus propofol 1 mg/kg, and group PMF(n=30) fentanyl 0. 05 mg, midazolam 2 mg and propofol 1 mg/kg. Propofol 20 mg was used when needed. HR,MAP,SpO_2,sedation scores and amnesia were recorded. Results All patients were awakened in 20 minutes after procedures. The recovery time was shorter in group PF than that in the other two groups. There were 21(67. 70%) patients in group PF, who were aware of surgery. Fifteen(48. 4%) patients were satisfied in group PF. Conclusion Propofol combined with midazolam and /or fentanyl in fibreoptic choledochoscope has better sedation without any obvious side effects.

Objective To investigate the changes in cerebral cAMP and PKA levels during development of acute opioid tolerance induced by remifentanil and to determine whether post-receptor cAMP/PKA signaling pathway is involved in the process. Methods Fifty-six male Kunming mice weighing 25-35 g were randomly divided into 5 groups: group Ⅰ control (C) (n=8); group Ⅱ received morphine infused intraperitoneally (IP) at 0.6 μg'kg-1·min-1 for 120min(M) (n=8); group Ⅲ,Ⅳ,Ⅴ received remifentnil infused IP at 0.4, 0.8 and 1.6 μg·kg-1·min-1 for 120 min(R1=8, R2n=8; R3 n=24).Control group received IP infusion of normal saline. Tail-flick test was performed td measure the response of animals to a thermal nociceptive stimulus before IP infusion, at 30, 60, 90 and 120 min after beginning of IP infusion and at 15, 30, 45 and 60 min after termination of IP infusion. Eight animals were decapitated at 60 min after termination of IP infusion in all 5 groups and the other 16 animals in group R3 were decapitated at 30 and 45 min after termination of IP infusion (n=8 each) for determination of intracellular contents of cAMP and activities of PKA in cerebral cortex and inferior colliculus-striatum by ELISA or radioactive isotope [32p,] ATP-catalyzing assay. Results The tail-flick latency was significantly prolonged during IP infusion as compared with the baseline before infusion in group M, R1 , R2 and R3 but became significantly shorter at 30 and 45 min after infusion than the baseline values in group R1, R2 and R3indicating hyperalgesia after remifentauil infusion. The cerebral contents of cAMP and PKA activities at 60 min after termination of infusion were comparable or decreased in group M, R1, R2 and R3 as compared with group C. There was no significant difference in cerebral cAMP contents and PKA activities at 30, 60 and 45 min after IP remifentanil infusion in group R3. Conclusion Remifentanil can induce acute hyperalgesic effect on mice, and there is no up-regulation of post-receptor cAMP/PKA signaling pathway in the acute opioid tolerance, which is not similar to that chronic opioid tolerance.

Objective To investigate the effects of midazolam on extracellular signal-regulated kinase 1 (ERK1),ERK2 and cyclic AMP response element binding protein (CREB) phosphorylation in hippocampal in rats.Methods Eighty male SD rats weighing 250-300 g were randomly divided into 2 groups ( n = 40) : group control (group C) and group midazolam (group M).The animals underwent a continuous multi-trial inhibitory avoidance training .The times of trial needed for each animal to attain the learning criterion ( 100 s) were recorded.Each animal was given intraperitoneal midazolam 3 mg/kg or normal saline 2 ml/kg at 15 min before training.The memory retention was tested at 0.5,1,2 and 24 h (n = 8,at each time point)after the training session and the memory latency was recorded.The animals were sacrificed 15 min after administration (T0) and after the memory testing (T1-4) and hippocampns was obtained for determination of phosphorylated ERK1 (p-ERK1),p-ERK2 and p-CREB expression.Results Compared with group C,the times of trial to attain the learning criterion were significantly increased,memory latency shortened at T2-4,ERK1 phosphorylation decreased at T0,3.4 while ERK2 and CREB phosphorylation decreased at T0-4.Conclusion Midazolam can inhibit ERK1,ERK2 and CREB phosphorylation in hippocampal in rats.

Objective: To investigate the changes of gastric intramucosal pH(pHi)and the association with hemody namics and oxygen utilization during cardiopulmonary bypass (CPB). Method: Adults (n=15)free of hepatic, pulmonary,and renal diseases undergoing nonemergent heart surgery,were selected. After induction of general anesthesia and endotracheal intubation,a tonometer nasogastric tube was positioned in the stomach to determine the intramucosal pH. Hemodynamics and oxygen utilization data and phi were measured at four times:30 minutes after induction of anesthesia; 15 minutes after termination of cardiopulmonary bypass; at the terminal of the surgery;and 1 day after the surgery. Result: Cardiac index significantly increased(P

Objective: To study the effects of the different doses of midazolam in fibreoptic gastroscopy on sedation, respiratory and circulatory function. Method: One hundred and four outpatients undergoing fibreoptic gastroscopy were randomly divided into four groups. The control group(N)was not given drugs, the other groups were intravenously given midazolam 0.07mg/kg(MS),0.05mg/kg(M),diazepam 10mg(D)respectively. The sedative scores, symptom, amnesia,HR,MAP and blood gases were observed. Result: The sedative scores of MS,M and D groups were much better than that of control group. There were significant differences in sedative scores,amnesia and sedative period between MS group and D group or M group. MAP decreased one minute after administering the drugs in MS,D and M groups significantly. The results of blood gases analysis of all groups were in normal ranges. Conclusion: Midazolam 0.07mg/kg can produce safe and effective sedation for fibreoptic gastroscopy.

Objective To evaluate the effect of lidocaine on delayed neuroal death after global cerebral ischemia. Methods Global cerebral ischemia was induced by the occlusions of bilateral commom carotid and vertebral arteries . Twenty-five rabbits were randomly divided into three groups:sham operative group (SH group,n=5) without the four-vessel occlusion; ischemia group(IS group,n=10) with intravenous normal saline of 15 ml followed by the four-vessel occlusion for 5 min; lidocaine group (LI group,n=10) with intravenous lidocaine of 10mg/kg followed by the four-vessel occlusion for 5 min. Three days later, every cerebrum was resected and stained using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and hematoxylin-eosin (HE) methods,to count the amount of the positive stained cells of hippocampus. Results The positive cell amount of HE staining (ischemic change cells) was correlated with that of TUNEL staining (apoptosis cells) (r=0.915).Compared with that in SH group, the amount of apoptosis cells increased significantly in IS and LI groups (P

Objective To study the effect of variant concentrations of lidocaine on voltage-dependent sodium current in dissociated hippocampal neurons of the ratMethods Voltage-dependent sodium currents in dissociated hippocampal neurons of the rat were recorded by whole-cell configuration of the patch clamp when a series of doses of lidocaine (10 -5mol/L-10 -2mol/L) were appliedResults Lidocaine reduced the amplitude of sodium current in a dose-dependent manner, with EC50 of (039?005)mmol/LConclusions Voltage-dependent sodium channel is related to cerebral protective effect of lidocaine, but has nothing to do with its nervous toxicity

Objective To observe the time profile of the changes of mRNA of ? and ? subunit of acetylcholine receptor (AChR) in skeletal muscle and the level of calcitonin gene related peptide (CGRP) in spinal motoneuron after upper motoneuron injury. Method The spinal cord of adult male Wistar rats was transected on the lower thoracic segment. The spinal cords below the transection level and soleus muscles were sampled 0,1,2,4,7 and 14 days after surgery, respectively, to detect the levels of mRNA of ? and ? subunit of acetylcholine receptor in soleus muscle using Northern blot method,and CGRP level in spinal motoneuron using radioimmunoassay.Results The levels of mRNA of ? and ? subunit of acetylcholine receptor siginificantly increased after surgery, but the level of mRNA of ? subunit increased earlier and higher than ? subunit. The level of CGRP in spinal motoneuron markedly reduced after surgery, was maintained at 50 80% of normal level since the 2nd day after surgery. Conclusions The levels of AChR ? and ? subunit in skeletal muscle significantly increase after upper motoneuron injury, the expression of which CGRP may regulate.