Objective To investigate the effect of lacosamide on expression of Nav1 .8 in dorsal root ganglia (DRG) in a rat model of chronic neuropathic pain.Methods Thirty-six female specific-pathogen-free (SPF)SD rats were randomly assigned into 3 groups ( n = 12 each): sham operation group (group S), model group (group M) and lacosamide group (group L) . Chronic neuropathic pain was produced by insertion of a small stainless steel rod (4.00 mm in length and 0.63 mm in diameter) into the L, intervertebral foramen in the rat, producing a chronic steady compression of the DRG in M and L groups. The mechanical threshold was measured 2 days before operation and on the 2, 4, 6, 7, 8, 9 and 10 days after operation (T0-7 ) . Intraperitoneal lacosamide 20mg/kg (in normal saline 0.5 ml) was injected at T4-7, twice a day in S and L groups. In group M, normal saline 0.5 ml was injected at T4-7 twice a day and the mechanical threshold was measured after the last administration everyday . The L, DRG on the operated side was removed after measurement of pain threshold to detect the expression of Na, 1.8 mRNA and protein by RT-PCR and immuno-histochemistry respectively. Results Compared with group S, the mechanical pain threshold was significantly decreased at T1-7 and the expression of Navl .8 mRNA and protein was up-regulated in M and L groups ( P < 0.05) . Compared with group M, the mechanical pain threshold was significantly increased at T4-7 and the expression of Nav 1.8 mRNA and protein was down-regulated in group L ( P < 0.05) . Conclusion The mechanism by which lacosamide reduces chronic neuropathic pain is related to the down-regulation of the expression of Nav 1.8 in rat DRG.

Objective To investigate the effectiveness of cis-diamminedichloroplatinum (DDP) combined with hyperthennia in killing liver tumor cells and its influence on erythrocytes in vitro. Methods Cultured liver tumor cells (2 ml) were mixed with erythrocyte suspension (10 ml) and then the mixture was separated into 6 centrifuge tubes with 2 ml in each one. The centrifuge tubes were randomly divided into A-F groups and the experiment was repeated for 30 times. Normal saline 2 ml was added in A and D groups. DDP 2 ml (200 μg/ml) was added in B and E groups. DDP 2 ml (400 μg/ml) was added in C and F groups. The cells were then incubated in warm bath of 37 ℃ for 30 min in A, B and C groups and in warm bath of 42 ℃ for 30 min in the other three groups.After hyperthermic treatment, tumor cells were isolated from erythrocytes using density gradient centrifugation, the inhibition rate of tumor cells was determined by MTT method and the clone formation of tumor cells was checked.The erythrocyte osmotic fragility and content of 2,3-diphosphoglyceric acid in erythrocytes were measured. Results The inhibition rate of tumor cells was gradually increased, while the rate of tumor cell clone formation decreased with the increase in the temperature and DDP concentrations ( P < 0.01) . The rate of tumor cell clone formation was more than 98% and no clone formation was tested in group F. There was no significant difference in the content of 2,3-diphosphoglyceric acid in erythrocytes between before and after hyperthermic treatment in group F ( P >0.05 ) . The rate of hemolysis of erythrocytes was less than 1 % in the 0.68 % sodium chloride solution in group F.Conclusion DDP 200 μg/ml combined with hyperthermic treatment with temperature of 42 ℃ for 30 min can make the liver tumor cells lose the capability of proliferation, however, it exerts slight effect on erythrocyte membrane and no influence on the oxygen-carrying capacity of erythrocytes.

Objective To determine if activation of AMP-activated protein kinase (AMPK) is involved in ropivacaine-induced reactive oxygen species (ROS) production and apoptosis in human neuroblastoma cell line SHSY5Y.Methods SH-SY5Y cell line was purchased from cell center of Shanghai life Science Research Institute,Chinese Academy of Sciences and cultured in DMEM/F12 liquid culture medium containing 15 % bovine calf serum at 37 ℃ in incubator filled with 5% CO2 . Plasmids pGPU6/GFP/Neo-shRNA AMPKα2 and pEGFP-N1-AMPKα2were transfected into the SH-SY5Y cell line. The expression of AMPKα2 was determined by Western blot analysis.The SH-SY5Y cells transfected with recombinant plasmids were exposed to 3 mol/L ropivacaine. Intracellular ROS was detected by flow cytometry. Cell viability was quantitatively determined by MTT colorimetry assay. Apoptosis was assessed by flow cytometry and Hoechst33258 staining. Results The plasmid pEGFP-N1-AMPKα2 upregulated while pGPU6/GFP/Neo-shRNA AMPKα2 down-regulated the expression of AMPKα2 ( P < 0.01). Down-regulation of AMPKα2 expression attenuated while up-regulation of. AMPKα2 expression promoted intracellular ROS production and cell apoptosis induced by ropivacaine ( P < 0.01) . Conclusion AMPK probably mediates ROS production and cell apoptosis induced by ropivacaine.

Objective To explore the difference in the effect of isoflurane inhalation on long-term cognitive function between male and female rate.Methods Forty-two SD rats (22 female, 20 male) that exhibited normal spontaneous activity and behaved normally in passive avoidance and Morris water maze tests were used in this study. They were divided into 2 sex groups:group female (group F) and group male (group M). Each group was further divided into 2 subgroups: control subgroup (Fc, Mc groups) and isoflurane group (Fs, Ms groups). The animals were anesthetized with 3 % isoflurane in O2 for 2 h in the 2 study subgroups, while the control subgroups inhaled O2 for 2 h. The spontaneous activity test was performed at 1, 30, 60 and 90 d, while the passive avoidance task was performed at 2, 30, 60 and 90 d after isoflurane anesthesia. Morris water maze test was performed for 5 consecutive days at 3-7 d, 31-35 d, 61-65 d, and 91-95 d after isoflurane anesthesia.Results In spontaneous activity test the total distance and the speed were significantly decreased at 1 d after isoflurane anesthesia in both Fs and Ms subgroups as compared with Fc and Mc subgroups. There was no significant difference in the number of error and latency after isoflurane anesthesia compared with the control subgroups in both male and female rats in the passive avoidance task. In Morris water maze test the escape latency and swimming distance were significantly prolonged at 1 and 31 d after isoflurane anesthesia as compared with control subgroup in female rats and at 3-6d, 31-34 d and 61 d after isoflurane anesthesia as compared with control subgroup in male rats, and were significantly longer after isoflurane anesthesia in male than in female rats. Conclusion Two hour 3.0% isoflurane anesthesia can impair long-term cognitive function and the impairment is greater in male than in female rats.

Objective To investigate the effect of isoflurane inhalation during gestation period on plasticity of hippo-campal synapses in offspring rats. Methods Ten healthy pregnant SD rats at 14 day gestation were randomly divided into 2 gorups ( n = 5 each): control group (group C) and isoflurane group (group I). The rats in group C were mechanically ventilated with O2 while in group I the rats inhaled 1.3% isoflurane in O2 for 2 h a day until labor. Four weeks after birth 4 offspring rats from each pregnant rats (2 male, 2 female) were tested for learning and memory abilities using Morris water maze. Then the offspring rats were sacrificed and hippocampi isolated. The synaptic structure of hippocampal CA1 area was examined by trans-electron microscopy. Results Morris water maze test showed that the escape latency was significantly shorter and the number of times of spanning flat roof greater in group C than in group I. The structure of hippocampus was intact in group C but incomplete in group I. Meanwhile the thickness of synaptic density was significantly decreased in group I. Conclusion Isoflurane anesthesia of pregnant rats may induce learning and memory disabilities in offspring rats by inhibiting the plasticity of synaptic structure in hippocampus.

Objective To investigate the efficacy of dexmedetomidine-assisted topical anesthesia in patients undergoing bronchoalveolar lavage ( BAL). Methods Twenty-four ASA Ⅱ or Ⅲ patients in ICU, aged 24-64 yr, weighing 50-80 kg, scheduled for BAL, were randomly divided into 2 groups ( n = 12 each) : topical anesthesia group (group A) , topical anesthesia + dexmedetomidine group (group B) . In group A, 0.9% normal saline 5 ml was injected intravenously 30 min before operation, 2% lidocaine 5-10 ml was given via a tracheal tube or cannula 5 min before operation and then an increment of 2% lidocaine 5 ml was given using fibreoptic bronchoscope every 15-30 min as required (the total amount was within 20 ml) . In group B, dexmedetomidine 0.5-1.0 μg/kg was injected (time of injection≥ 10 min) followed by infusion at 0.1-0.5 μg·kg-1 ·h-1 and the topical anesthesia was performed as the method described in group A. The time of lavage, adverse reactions and adverse cardiovascular events were recorded. Blood samples were taken 20 min before lavage, 20 min after the start of lavage and 20 min after the end of lavage (T1-3 ) for determination of the concentrations of plasma catecholamine and serum cortisol. Results The incidences of adverse reactions and adverse cardiovascular events were significantly lower and the operation time was significantly shorter in group B than in group A ( P < 0.05). The concentrations of plasma catecholamine and serum cortisol were significantly higher at T2，3 in group A, while lower at T2，3 in group B than at T1 ( P < 0.05) . The concentrations of plasma catecholamine and serum cortisol were significantly lower in group B than in group A ( P < 0.05). Conclusion Dexmedetomidine-assisted topical anesthesia can be used safely and effectively in BAL.

Objective To investigate the effect of injection of air into the epidural space on the subarachnoid puncture during the combined spinal-epidural anesthesia (CSEA) .Methods Two hundred and ten ASA Ⅰ or Ⅱ parturients who were at full term with a singleton fetus, aged 20-42 yr, weighing 57-82 kg (height 152-170cm) , undergoing cesarean section under CSEA, were randomly divided into 3 groups ( n = 70 each) : hanging drop technique group (group Ⅰ ) and injection of small volume of air group (group Ⅱ ) and injection of large volume of air group ( group Ⅲ ) . The epidural space was indentified using hanging drop technique in group Ⅰ and using loss of resistance to air technique in Ⅱ and Ⅲ groups. Injection of air was stopped as soon as the clear loss of resistance identified the epidural space in group Ⅱ , whereas all 4 ml of air was injected in group Ⅲ . After the epidural space was confirmed at L3,4 interspace, a 25-gauge spinal needle protruding 14 mm beyond the 18-gauge epidural needle was introduced through the epidural needle. Subarachnoid placement was confirmed by backflow of cerebrospinal fluid (CSF) . If no backflow of CSF was observed, the spinal needle was withdrawn and an epidural catheter was inserted through the epidural needle to perform epidural anesthesia. Successful subarachnoid puncture, failures to observe backflow of CSF and adverse reactions were recorded. Results The three groups were comparable with respect to age, height, body weight and gestation weeks. The success rate of subarachnoid puncture was 91% ,93% and 79% in Ⅰ ,Ⅱ and Ⅲ groups respectively, and it was significantly higher in Ⅰ and Ⅱ groups than in group Ⅲ ( P < 0.05) . There was no significant difference in the success rate of subarachnoid puncture between Ⅰand Ⅱ groups ( P > 0.05) . Bilateral segmental analgesia presented in all cases who received only epidural anesthesia after no backflow of CSF was observed, and the expected analgesia also presented in all cases in whom back flow of CSF was observed. No adverse reactions occurred. Conclusion Injection of air into the epidural space is related to the success of subarachnoid puncture during CSEA and injection of a large volume of air lowers the success rate.

Objective To determine the median effective doae (ED50) for motor block after intrathecal ropivacaine and bupivacaine. Methods Sixty ASA Ⅰ or Ⅱ patients, aged 18-64, weighing 46-75 kg, undergoing elective urological surgery under combined spinal-epidural anesthesia, were randomized into 2 groups ( n = 30each) receiving intrathecal 0.5% ropivacaine and 0.5% bupivacaine respectively. The ED50 was determined by up-down sequential allocation. The initial dose was 4 mg. Each time the dose increased/decreased by 1 mg. Efficacy was determined by the occurrence of any motor block in either lower extremity (modified Bromage scale > 0)within 5 or 10 min after the spinal injection. Results The intrathecal ED50 for motor block was 6.68 mg for ropivacaine (95% confidence interval 6.27-7.13 mg) and 4.07 mg for bupivacaine (95% confidence interval 3.56-4.47mg) . The relative motor blocking potency ratio was ropivacaine/bupivacaine 0.61. Conclusion The potency of intrathecal ropivacaine is lower than that of bupivacaine for motor block.

Objective To investigate the effect of sevoflurane preconditioning-postconditioning on thromboxane A2 and prostaglandin I2 during myocardial ischemia-reperfusion (I/R) in rats. Methods Fifty healthy male Wistar rats weighing 250-280 g were randomly divided into 5 groups (n = 10 each) : sham operation group (group S) , I/R group, sevoflurane preconditioning group (group Spr), sevoflurane postconditioning group (group Spo)and combination of sevoflurane preconditioning and postconditioning group (group Spr + po). Myocardial I/R was produced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 2 h reperfusion in anesthetized rats. In group S the anterior descending branch was only exposed but not ligated. Group Spr received 15 min inhalation of 2.5 % sevoflurane and 15 min wash-out 30 min before ischemia. Group Spo received 5 min inhalation of 2.5% sevoflurane 1 min before reperfusion. Arterial blood samples were taken at 2 h of reperfusion for determination of the levels of MB isoenzyme of creatine kinase (CK-MB) , lactate dehydrogenase (LDH) , cardiac troponin I (cTnI), thromboxane B2(TXB2), and 6-keto-prostaglandin (6-keto-PGF1α) and platelet maximum aggregation rate. TXB2/6-keto-PGF1α ratio was calculated. The myocardial tissues were taken for microscopic examination. Mitochondria] injury was assessed by using Flameng score and stereology (Specific surface, δ and Numerical density on area, NA) .Results Compared with group S, the levels of CK-MB, LDH, cTnI, TXE2 and 6-ketoPGF1α, TXB2/6-keto-PGF1α ratio, platelet maximum aggregation rate and Flameng score were significantly increased, while δ and NA were significantly decreased in group I/R (P < 0.05 or 0.01) . The levels of CK-MB,LDH and cTnI, TXB2/6-keto-PGF1α ratio and Flameng score were significantly lower, and 6-keto-PGF1α level, δand NA were significantly higher in Spr and Spo groups than in group I/R ( P < 0.05 or 0.01) . The levels of CKMB, LDH, cTnI and TXB2 , TXB2/6-keto-PGF1α ratio, platelet maximum aggregation rate and Flameng score were significantly lower and 6-keto-PGF1α level,δ and NA were significantly higher in group Spr + po than in Spr and Spo groups(P < 0.05). Conclusion Sevoflurane preconditioning-postconditioning can reduce myocardial I/R injury through inhibiting the release of thromboxane A2 and promoting the release of prostaglandin I2 in rats.

Objective To investigate the effects of calcitonin gene-related peptide (CGRP) combined with norepinephrine (NE) on L-type calcium current (LCa-l) in rat ventricular myocytes. Methods Ventricular myocytes were isolated from SD rats (weighing 260-280 g) by retrograde perfusion of the heart via the aorta with an enzyme-containing solution as previously described. Whole-cell patch-clamp recording was made using Axopatch 200B amplifier. The cells were perfused for 1 min with Tyrode solution containing CGRP 1 × 10-7 mol/L (group CGRP) , NE 1 × 10-6 mol/L (group NE), or CGRP 1 × 10-7 mol/L + NE 1 × 10-6 mol/L (group CN) and again washed with Tyrode solution. ICa-L was recorded 1 min before and 1 min after the cells were perfused and 1 min after the cells were washed. I-V curve of ICa-L was made after the cells were perfused with solution containing CGRP or NE alone. Results CGRP significantly inhibited the peak of ICa-L, while NE significantly promoted the peak of ICa-L(P < 0.05) . The peak of ICa-L was significantly decreased 1 min after the cells were perfused in group CGRP,while increased 1 min after the cells were perfused in group NE compared with group CN ( P < 0.05). CGRP made the I-V curve of ICa-L move up-ward, while NE made the I-V curve of ICa-L move down-ward. Conclusion CGRP can weaken the promotion of ICa-L induced by NE in rat ventricular myocytes.