Objective To investigate the effects of mild hypothermic cardiopulmonary bypass(CPB) on bax and bcl-2 protein expression and neuronal apoptosis in hippooampus CA1 region in rats. Methods Healthy male SD rats weighing 380-420g were randomly divided into 3 groups: (1)post-CPB 1h group (n=6); (2) post-CPB 6h group (n=6) and (3) sham CPB group(n=5). The animals were anesthetized with intraperitoneal fentanyl 150?g?kg~(-1), midazolam 1 mg?kg~(-1) and vecurunium 0.1 mg?kg~(-1), intubated and mechanically ventilated. Left femoral artery was cannulated for heparinizafion, BP monitoring and blood sampling. Artery in the tail and right jugular vein were cannulated for CPB. The animals in group 1 and 2 underwent 2 h mild hypothermic (26-28℃) CPB at a flow of 160 ml?kg~(-1)?min~(-1). 1h(group 1) and 6h(group 2) after CPB 4% polymerized formaldehyde was injected via the artery in the tail. Brains were immediately removed. Bax and bcl-2 protein expression in hippocampus CA1 region was determined by immuno-histochemistry method and neuronal apoptosis by TUNEL technique. Ultrastructural changes were examined with electron microscope. Results (1)Bax and Bcl-2 protein expressions were significantly higher in group 1(1h after CPB)than in sham CPB group. Bax protein expression was significantly higher but bcl-2 protein expression was significantly lower in group 2 than in group 1. bax/bcl-2 ratio in group 2(at 6h after CPB)was significantly higher than that in group 1(at 1h after CPB). (2) Neuronal apoptosis was significantly increased in group 1 and 2 compared to sham CPB group. (3) Electron microscopy showed that some mitochondria were moderately or severely swollen with vacuolizafion and decreased number of mitochondrial at 1h after CPB and at 6h after CPB there was shrinkage of neuronal cells with irregular shape of nucleus, notches in nuclear membrane and margination of nucleoli. Conclusion CPB induces upregulation of both bax and bcl-2 protein expression with predominance of the pro-apoptotic gene Bax leading to increased neuronal apoptosis, indicating that CPB can cause brain injury.

Objective To investigate the safety of inhalation of isoflurane (ISO) or sevoflurane (SEVO) mixed with nitric oxide (NO) during mechanical ventilation.Methods Thirty-six healthy piglets of both sexes weighing 7-11 kg were randomly allocated to one of 6 groups ( n = 6 each): (1) control group was mechanically ventilated with O2; (2) NO group inhaled 20 ppm NO; (3) ISO group inhaled 1.3 MAC isoflurane; (4) ISO + NO group 1.3 MAC isoflurane + 20 ppm NO; (5) SEVO group inhaled 1.3 MAC sevoflurane and (6) SEVO + NO group inhaled 1.3 MAC sevoflurane + 20 ppm NO. The animals were mechanically ventilated with IPPV (VT 10 ml?kg-1 , RR 30-40 bpm, I: E 1:2) for 4 h in the all 6 groups. The animals were premedicated with atropine 0.02 mg?kg-1 i.m. . The Ⅳ line was established for fluid and drug administration. An additional dose of ketamine 10 mg?kg-1 was given i.v. before tracheostomy. 4F S-G catheter was placed in pulmonary artery via right internal jugular vein for hemodynamic monitoring. Femoral artery was cannulated for BP monitoring and collection of artrerial blood samples. MAP, HR, CVP, right ventricular pressure (RVP), PCWP, MPAP and total compliance of respiratory system (Crs), Paw, VT and PET CO2 were recorded before (T0 ) and at 1, 2, 3, 4 h of ventilation (T1-4). Blood samples were taken at T0 , T2 and T4 for determination of Met Hb and NO2- /NO3- . The animals were killed at the end of 4 h mechanical ventilation and the lungs were removed for determination of wet/dry(W/D) lung weight ratio, broncho-alveolar lavage fluid (BALF) and microscopic examination. BALF was collected for determination of surface tension and concentrations of saturated phosphate (DSPC) , total phosphate (TPL) total protein (TP) and white cell count. Results Crs was significantly decreased at the end of ventilation (T4 ) as compared with the baseline (T0) in group 3,4,5 and 6, while there was no significant change in Crs in group 1 and 2. DSPC/TP was significantly lower in group 3,4,5 and 6 than in group 1 ( P 0.05 ) . Conclusion 1.3 MAC isoflurane or sevoflurane mixed with 20 ppm NO can be used safely during mechanical ventilation.

desflurane. The one of hepatotoxic mechanism of inhatational anesthetics may be to inhibit the proliferation and albumin secretion.

Objective: To observe the effects of neuromuscular blockade after combining atracurium (ATC) with veeuronium (VEC). Method: Fifty-four patients undergoing elective abdominal surgery(ASA grade Ⅰ-Ⅱ) were allocated randomly into 3 groups. After induction with intravenous midazolam-etomidate-fentanyl, neuromuscular blockade was measured with the train of four (TOF) to the ulnar nerve by monitoring the contraction of musculus adductor pollicis. The onset time and the peak effect were observed. According to the dose-effect relationships of the combination of ATC and VEC and that of either ATC or VEC given alone,the ED_(50) and ED_(95) were caeulated. The isogram and algebraic methods were used to analyse interaction between them. Result: The fraction ED_(50) values of ATC and VEC in combination were 52.26 and 11.71?g/kg respectively, The algebraic subtotal of combinations was 0.75

Objective To evaluate the effects of bupivacaine and ropivacaine on guinea pig papillary muscle action potential Methods The guinea pig papillary muscle preparation was exposed to ropivacaine (1, 3 or 5?g?ml -1 ) or bupivacaine ( 1, 3 and 5?g?ml -1 ) respectively, to measure maximum rate of depolarization (Vmax ), action potential amplitude (APA),action potential duration at 50% of repolarization(APD 50 ), and action potential duration at 90% of repolarization(APD 90 ) Results Vmax significantly decreased after exposure to both agents at all concentrations, Vmax decreased by 27 4% with ropivacaine at 5?g?ml -1 , and the degree was similar to that with bupivacaine at 3 ?g?ml -1 (28 4%) ,but was significantly lower than that with bupivacaine at 5 ?g?ml -1 (42 6%) (P

Objective To evaluate the efficacy of epidural block combined with general anesthesia for elderly upper abdominal surgery Methods Thirty-four elderly patients ,scheduled for elective upper abdominal surgery, ASA grade Ⅰ-Ⅱ, were divided randomly into study group (groupⅠ) and control group (group Ⅱ) In both groups anesthesia was induced with introvenous diazepam 0 1mg?kg -1, fentanyl 5?g?kg -1, etomidate 3mg?kg -1, atracurium 0 2 mg?kg -1 and succinylcholine 2 mg?kg -1, and was maintained with intravenous infusion of propofol 4-10ml/h and/or inhalation of 1% isoflurane and intermittent bolus of atracurium In groupⅠ epidural block was performed before induction Hemodynamics was measured with impendence cardiography and electroencephagram were monitored and intraoperative awareness, postoperative restlessness and anesthetic dosage were recorded, also the concentrations of plasma vasopressin and blood glucose were determined at pre-operation, incision and the end of surgery Results In group Ⅰ MAP,CO,HR incresed slightly during intubation, incision and extubation, and systemic vascular resistance (SVR) decreased during operation , but SVR was increased abruptly after extubation in group Ⅱ There were unsignificant changes in thoracic fluid index(TFI), stroke volume(SV), ejection volume index(EVI), EVI/TFI ratio in both groups during whole procedures SEF was recovered more earlier in group Ⅰthan that of in group Ⅱ after extubation The vasopressin and glucose levels increased significantly after-extubation compared with those before operation in group Ⅱ Conclusions The epidural block combined with general anesthesia can be more effectvely and safely applied to elderly upper abdominal surgery

Ⅳ, SVR and PVR decreased markedly at the same time MERO 2 and MDO 2/MVO 2 dod not change significantly but MVO 2/MDO 2 showed a tendency of decreasing after the inotropics administration compared with the control group Electronic microscopy examinations: 30min after the inotropics were stoped, the myocardial ultrastructure of ischemic area did not improved significantly in group Ⅱ and Ⅲversus the group Ⅰ, but in group Ⅵ, Ⅴ and Ⅳ, the interstitial and intracellular edema reduced markedly, the capillary stasis vanished, and very few vacuole could be seen in mitochondria Conclusions 1 The response of stunned myocardium to ? agonists decreases 2 Inotropic can restore regional work by restoring mechanical synchrony and improving energy efficiency, the effects of combined inotropics are better than the inotropics given alone in myocardial stunning

Objective To evaluate the roles of K ATP channels in desflurane-induced myocardial protection from anoxia/reoxygenation injury Methods Primary cultured rat myocardial cells were randomly allocated to four groups: control group(A): without any treatment; anoxia/reoxygenation group(B): reoxygenation of 1 h following anoxia of 2 h; desflurane preconditioning group(C): 20 min of 9% desflurane preconditioning followed by 10 min washout before anoxia/reoxygenation and K ATP channel blocker group(D): adding glybenclamide at final concentration of 12?g/ml to culture medium 10 min before the same procedures as group C The activities of lactic dehydrogenase (LDH) and creatine kinase (CK), rates of cell viability and apoptosis, contents of cellular malondiadehyde (MDA) and adenosine triphosphate (ATP), and intracellular free calcium concentration were measured Results Compared with control group, anoxia/reoxygenation caused great increases of levels of LDH, CK, apoptosis and MDA ,and decreases of ATP and cell viability (P

Objective To investigate the effects of regional myocardial stunning on systemic hemodynamics and myocardial oxygen balance Methods Thirty three open chest anesthetized dogs were subjected to 15min left anterior descending (LAD) coronary artery occlusion under normal temperature, the systemic hemodynamics, coronary blood flow (CBF), myocardial oxygen delivery(MDO 2) and consumption(MVO 2)were determined following reperfusion Results MAP decreased slightly during LAD occlusion, but returned to baseline following reperfusion CO, SV and LVSWI reduced rapidly after LAD occlusion, increased slightly 5min following reperfusion, followed by a more severe reduction , with the progressive increases of SVR and PVR during whole periods At the early stage of reperfusion (5min), CBF, MDO 2 and MVO 2 increased significantly, then decreased rapidly 10min following reperfusion Myocardial oxygen extraction rate remained stable during whole procedures Histological changes of ischemic area 30min following reperfusion showed interstitial and intracellular edema, mitochondrial vacuolization, and capillary stasis under electronic microscopy Conclusions Regional myocardial stunning may resulte in sinificant changes of systemic hemodynamics; at the early stage of reperfusion, oxygen consumption paradox occurres ,but MDO 2 matches MVO 2 10min following myocardial reperfusion

Objective To observe the effects of desflurane, sevoflurane and isoflurane on hepatic oxygen balance and hepatic blood flow Methods Fifteen pigs were randomly divided into three groups: A desflurane group(n=5), B sevoflurane group(n=5), C isoflurane group(n=5) This study observed the effects of desflurane, sevoflurane and isoflurane on systemic and hepatic blood flow and oxygen balance with different concentrations using continuous thermodilution cardiac output monitor and ultrasonic Doppler blood flow monitorResults ①Hepatic blood flow: total hepatic blood flow(THBF) decreased dose-dependently in three groups without significant differences between groups The effects of desflurnae and sevoflurane on THBF were same as those on cardiac output(CO), while the effect of sevoflurane on THBF was larger than that on CO ②Oxygen balance: both systemic oxygen delivery(DO_2) and hepatic oxygen delivery(HDO_2) decreased significantly with the increasing of inhalation concentrations, systemic oxygen delivery(VO_2) and hepatic oxygen consumption(HVO_2) decreased significantly only at high concentration The effects of desflurnae and sevoflurane on HVO_2 and HDO_2 were same as those on VO_2 and DO_2, while the effect of sevoflurane on HDO_2 was larger than that on DO_2, but the effect of sevoflurane on HVO_2 was still same as that on VO_2Conclusions Because of the dose-dependently decreased hepatic blood flow, hepatic oxygen delivery decreases significantly, but hepatic oxygen consumption can be maintained well by self-regulation of hepatic oxygen extraction ratio,indicating that there is almost no influence on hepatic intracellular respiration and metabolism