We analyzed the special characteristics of postgraduate education for anesthesiology majors based on the current situation of medical postgraduate education.Next,we introduced the ‘ sandwich' teaching method and discussed how it can promote students' subjective initiative by transforming various learning patterns.Finally,the effectiveness of study was elevated by ‘sandwich' teaching method.

Objective To investigate whether diazoxide preconditioning can exert protective effect on myocardium against ischemia-reperfusion injury in immature rabbits and the possible mechanism. Methods Twenty-one healthy 3-4 week old white rabbits of either sex were randomly divided into 3 groups : group Ⅰ control ( n = 8) ; group Ⅱ diazoxide preconditioning ( n = 8) and group Ⅲ diazoxide + 5-HD preconditioning ( n = 5) . The animals were anesthetized with intraperitoneal pentobarbital 50 mg?kg-1 and heparized (150 IU?kg-1). The hearts were excised and connected to Langendorff apparatus and passively perfused with normothermic (37℃), oxygenated (95% O2 , 5% CO2) Krebs-Henseleit buffer (KHB) at a constant perfusion pressure of 70cmH2O. A latex balloon was inserted via left atrium into left ventricle and filled with water. The left ventricular end-diastolic pressure (LVEDP) was maintained at 10 mm Hg. In group I cardiac arrest was induced with St Thomas Ⅱ solution after the heart was perfused with KHB for 30 min. In group 11 after being perfused with KHB for 15 min, the hearts were perfused with diazoxide 100?mol?L-1 for 5 min followed by 10 min wash-out with KHB , then cardiac arrest was induced as in group Ⅰ . In group Ⅲ after being perfused with KHB for 15 min, the hearts were perfused with diazoxide 100?mol?L-1 and 5-HD 100?mol?L-1 for 5 min, followed by 10 min wash-out with KHB, then the cardiac arrest was induced as in group Ⅰ and Ⅱ . All hearts were subjected to 30 min ischemia followed by 45 min reperfusion after cardiac arrest. Coronary flow (CF), HR, left ventricular developed pressure (LVDP) and dp / dt max were measured after the hearts were perfused with KHB for 15 min (baseline) and at 5, 10, 15, 30, 45 min after reperfusion was resumed. Coronary effluent was collected at 5 min after reperfusion was resumed for determination of myocardial enzymes, CK, LDH and AST. At the end of experiment myocardial specimen was obtained for determination of ATP content and ultrastructure examination. Results There was no significant difference in the baseline hemodynamic parameters among the three groups. The rates of recovery of LVDP and ? dp / dt max after reperfusion were significantly higher in group Ⅱ than those in group I and Ⅲ ( P 0.05 ) , Conclusion Diazoxide can protect myocardium from ischemia-reperfusion injury by opening the mitochondrial KATP channel in immature rabbits.

ObjectiveTo investigate the effect of cardiopulmonary bypass (CPB) on the secretory function of islet cells in rabbits.MethodsTwenty adult New Zealand white rabbits of both sexes,weighing 2.5-3.0kg,were randomly divided into 2 groups ( n =10 each):sham operation group (group S) and CPB group.The rabbits were anesthetized with 3％ pentobarbital sodium 30 mg/kg.Blood samples were collected from the left femoral artery at 5 min after anesthesia (T1),immediately before CPB (T2 ),immediately after aortic clamping (T3 ),and at 5,35 and 75 min after aortic unclamping (T4-6) in the two groups for determination of levels of blood glucose,insulin and glucagons.Insulin resistance index was calculated.ResultsCompared with group S,the blood glucose concentration and levels of insulin and glucagons and insulin resistance index at T3-6 were significantly increased in group CPB ( P ＜ 0.05).ConclusionAlthough increase in blood glucose enhances the secretion of insulin in islet β cells,hyperglycemia cannot be compensated completely by the increased insulin during CPB in rabbits.The increase in blood glucose may be related to islet α cell resistance.

Objective To investigate the effect of Shenfu injectio on insulin resistance in rabbits undergoing cardiopulmonary bypass (CPB) . Methods Thirty New Zealand white rabbits of both sexes weighing 2.2-2.5 kg were randomly divided into 3 groups (n = 10 each): group I sham operation (group S); group Ⅰ CPB and group Ⅰ CPB + Shenfu injectio (group SFI). In group IE (group SFI) Shenfii injectio 10 ml/kg was injected intraperitoneally (IP) once a day for 2 days and at 30 min before anesthesia. In group Ⅱ and Ⅲ the duration between aortic cross-clamping and unclamping was 60 min. MAP was maintained at 50-60 mm Hg during CPB. The plasma glucose and insulin concentrations were measured immediately after induction of anesthesia (T_1), immediately after aortic cross-clamping (T_2) , and at 5, 35 and 75 min after aortic unclamping (T_3, T_4 , T_5) and insulin resistance index (HOMA-IR) was calculated. The expression of insulin receptor substrate-1 (IRS-1), phosphatidyl-inositol 3 kinase (PI3Kp85) and glucose transporters (CLUT4) in skeletal muscle was detected at 150 min of CPB by immuno-histochemistry. Results Compared with the baseline values at T_1 , plasma glucose and insulin concentrations and HOMA-IR were significantly increased at T_(2-5) in all 3 groups ( P < 0.05) . CPB significantly increased the plasma glucose and insulin concentrations and HOMA-IR at T_(2-5) in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). The expression of PI3Kp85 and GLUT4 in muscle was significantly decreased in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). Shenfu injectio significantly decreased plasma glucose concentration and HOMA-IR and increased plasma insulin concentration in group fD as compared with group Ⅱ . Shenfu injectio significantly attenuated the CPB-induced changes in IRS-1, PI3Kp85 and GLUT4 expression in muscle. Conclusion Shenfu injectio can ameliorate CPB-induced insulin resistance and the mechanism may be related to the up-regulation of the expression of insulin signal transduction molecules in skeletal muscle.

Objective To investigate the effects of preconditioning with different concentrations of nerve growth factor (NGF)-β on ischemia-reperfusion (I/R) injury in isolated rat hearts.Methods Thirty-two male Sprague-Dawley rats weighing 200-300 g,aged 8-10 weeks,were anesthetized with intraperitoneal 10％ chloral hydrate 300 mg/kg and heparin 500 IU/kg.Their hearts were excised and perfused in a Langendorff apparatus with K-H solution oxygenated with 95％ O2-5％ CO2 at 37 ℃.After 10 min of stabilization,the isolated hearts were randomly divided into 4 groups (n=8 each): I/R group and different concentrations of NGF-β groups (groups N1-N3).In group I/R,the hearts were continuously perfused with K-H solution for 30 min,perfusion was suspended for 30 min followed by 120 min reperfusion.In groups N1-N3,the hearts were continuously perfused with K-H solution containing NGF-β0.1,0.2 and 0.4 ng/ml,respectively,for 20 min,followed by 10 min washout,and perfusion was suspended for 30 min followed by 120 min reperfusion.HR,Left ventricular end-diastolic pressure (LV-EDP),left ventricular developed pressure (LVDP) and + dp/dtmax were measured at the end of 10 min stabilization (baseline,T1),immediately before suspension of perfusion (T2),and at 5,30,60 and 120 min of reperfusion (T3-6).The activities of creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH) in the coronary effluent were measured at T1 and T3-T6.Myocardial tissues were obtained at T6 for detection of apoptosis (by TUNEL) and for microscopic examination.Apoptotic index (AI) was calculated.Results Compared with the baseline value at T1,LVDP and + dp/dtmax were significantly decreased,and LVEDP and activities of LDH and CK-MB were significantly increased at T3-T6 in each group,HR was significantly decreased in groups I/R,N2 and N3,while HR was significantly increased in group N1 (P ＜ 0.05).Compared with group I/R,LVDP,+ dp/dtmax and HR were significantly increased,LVEDP,activities of LDH and CK-MB and AI were significantly decreased in group N1,LVDP,+ dp/dtmax and HR were significantly decreased,and activities of LDH and CK-MB were significantly increased in group N2,and LVDP,+ dp/dtmax and HR were significantly decreased,and LVEDP,activities of LDH and CK-MB and Al were significantly increased in group N3 (P ＜ 0.05).LVDP,+ dp/dtmax and HR were significantly lower,and LVEDP,activities of LDH and CK-MB and AI were significantly higher in groups N2 and N3 than in group N1,and in group N3 than in group N2 (P ＜ 0.05).The pathologic changes were reduced in group N1 compared with I/R,N2 and N3 groups.Conclusion Preconditioning with the optimum concentration of NGF-β can at-tenuate I/R injury in isolated rat hearts,however,the injury can be aggravated when the concentration is too large,and inhibition of apoptosis in myocardial cells is involved in the mechanism of myocardial protection.

Objective To evaluate the effect of pretreatment with nerve growth factor-beta (NGF-β) on ischemia-reperfusion (I/R) injury in isolated rat hearts by comparing it with NGF-β preconditioning.Methods Pathogen-free male Sprague-Dawley rats,weighing 200-300 g,aged 8-10 weeks,were anesthetized with intraperitoneal 10％ chloral hydrate 300 mg/kg.Their hearts were excised and perfused in a Langendorff apparatus with KH solution aerated with 95％ O2 and 5％ CO2 at 37℃.Twenty-four isolated rat hearts were randomly divided into 3 groups (n =8 each) using a random number table:I/R group,NGF-β pretreatment group (group NGFPt) and NGF-β preconditioning group (group NGFPc).The hearts were perfused with K-H solution for 10 min (equilibration) in each group.In group I/R,the hearts were continuously perfused with K-H solution for 30 min.The hearts were continuously perfused with K-H solution containing NGF 0.1 μg/ml for 20 min before ischemia in group NGF-Pt.The hearts were continuously perfused with K-H solution containing NGF 0.1 μg/ml for 20 min followed by 10 min washout before ischemia in group NGFPc.The perfusion was suspended for 30 min followed by 120 min of reperfusion with K-H solution in each group.HR,left ventricular end-diastolic pressure (LVEDP),left ventricular developed pressure (LVDP) and + dp/dtmax were measured at the end of 10 min equilibration (baseline,T1),immediately before suspension of perfusion (T2),and at 5,30,60 and 120 min of reperfusion (T3-6).The activities of creatine kinase isoenzyme-MB (CK-MB) and lactate dehydrogenase (LDH) in coronary effluent were measured at T1 and T3-6.Myocardial specimens were obtained at T6 for detection of myocardial apoptosis (by TUNEL) and for microscopic examination.Apoptotic index (AI) was calculated.Results Compared with the baseline value at T1,+ dp/dtmax was significantly decreased,and LVEDP and activities of CK-MB and LDH were increased at T3-6 in each group,LVDP and HR were decreased at T3-6 in group I/R,LVDP was decreased at T3,4 in group NGFPt and at T3-6 in group NGFPc,and HR was increased at T2-6 in NGFPt and NGF Pc groups (P ＜ 0.05).Compared with group I/R,LVDP,+ dp/dtmax and HR were significantly increased and LVEDP and activities of CK-MB and LDH and AI were decreased in NGFPt and NGFPc groups (P ＜ 0.05).Compared with group NGFPc,LVDP,+ dp/dtmax and HR were significantly increased,while the LDH activity and AI were decreased (P ＜ 0.05) and no significant changes were found in LVEDP and CK-MB activity in group NGFPt (P ＞ 0.05).The pathologic changes of myocardium were significantly reduced in NGFPt and NGFPc groups as compared with I/R group.Conclusion Pretreatment with 0.1 μg/ml NGF-β attenuates I/R injury in isloated rat hearts,and the efficacy is superior to that of NGF-β preconditioning.

Objective To investigate the blood-saving effect of controlled low central venous pressure (CLCVP) in different types of hepatectomy.Methods Ninety ASA physical status Ⅰ or Ⅱ patients of both sexes,aged 37-76 yr,weighing 40-75 kg,undergoing elective hepatectomy,were divided into 6 groups according to the surgical approach and whether CLCVP was used during surgery (n =15 each):CLCVP1-3 groups and nonCLCVP1-3 groups (NCLCVP1-3 groups).The standard hepatectomy,half liver resection and irregular hepatectomy were performed in CLCVP1-3 groups,respectively,with CLCVP.The standard hepatectomy,half liver resection and irregular hepatectomy were performed in NCLCVP1-3 groups,respectively,without CLCVP.In CLCVP1-3 groups,from skin incision to the end of liver resection,CVP was maintained ≤ 5 cm H2 O through adjustment of the position,fluid restriction and iv infusion of nitroglycerin,and norepinephrine was infused simultaneously to maintain mean arterial pressure ≥ 60 mm Hg.In NCLCVP1-3 groups CVP was maintained at 6-12 cm H2O.Intraoperative blood loss and blood transfusion were recorded.Results Compared with NCLCVP1-3 groups,intraoperative blood loss was significantly decreased in CLCVP1-3 groups (P ＜ 0.05).Compared with NCLCVP3 group,the amount of blood transfusion was significantly decreased,the constituent ratio of intraoperative blood loss ＜ 200 ml was increased,and the constituent ratio of intraoperative blood loss ＞ 1000 ml was decreased in group CLCVP3 (P ＜ 0.05).Conclusion CLCVP can decrease the intraoperative blood loss and blood transfusion in patients undergoing irregular hepatectomy.

Objective To evaluate the effects of nerve growth factor-beta (NGF-β) pretreatment on cell apoptosis induced by endoplasmic reticulum stress during ischemia-reperfusion in isolated rat hearts.Methods Male Sprague-Dawley rats,weighing 180-220 g,were anesthetized with intraperitoneal 10％ chloral hydrate 300 mg/kg.The hearts were excised and perfused in a Langendorff apparatus with K-H solution aerated with 95％ O2 and 5％ CO2 at 37 ℃.Thirty-two isolated rat hearts were randomly divided into 4 groups (n =8 each) using a random number table:control group (group C),I/R group,NGF-β pretreatment group (group N) and NGF-β combined with K252a (trkA receptor antagonist) pretreatment group (group N + K).In group C,the hearts were continuously perfused with K-H solution for 195 min.The hearts were perfused with K-H solution for 45 min in group I/R.In N and N + K groups,the hearts were perfused with K-H solution for 15 min,and then with K-H solution containing 0.1 μg/ml NGF-β and 0.1 μg/ml NGF-β mixed with 100 nmol/L K252a,respectively,for 30 min.The perfusion was suspended for 30 min followed by 120 min of reperfusion with K-H solution in I/R,N and N + K groups.HR,left ventricular end-diastolic pressure (LVEDP),left ventricular developed pressure (LVDP) and + dp/dtmax were measured at the end of 15 min equilibration (baseline) and at 5,30,60 and 120 min of reperfusion.Myocardial specimens were obtained at 120 min of reperfusion for detection of myocardial apoptosis (by TUNEL) and expression of glucose-related protein 78 (GRP78),CCAAT/enhancer-binding protein homologous protein (CHOP),and caspase-12 (by Western blot analysis).Apoptosis index was calculated.Results Compared with group C,HR,LVDP and + dp/dtmax were significantly decreased,and LVEDP,apoptosis index and expression of GRP78 and CHOP were increased in I/R and N groups,and the expression of caspase-12 was upregulated in I/R group.Compared with group I/R,HR,LVDP,and + dp/dtmax were significantly increased,and LVEDP,apoptosis index and expression of GRP78,CHOP and caspase-12 were decreased in group N,and the expression of GRP78 was down-regulated in group N + K.There was no significant difference in cardiac function indexes between group I/R and N + K.Compared with group N,HR,LVDP and + dp/dtmax were significantly decreased,and LVEDP,apoptosis index,and expression of GRP78,CHOP and caspase-12 were increased in group N + K.Conclusion NGF-β pretreatment can protect the isolated rat hearts against ischemia-reperfusion injury,and inhibition of the endoplasmic reticulum stress-triggered cell apoptosis after activating trkA receptors is involved in the mechanism.

Aim To investigate the anti-apoptotic effect of NGF on H9 c2 cardiac myocytes in a hypoxia / reox-ygenation injury model and its mechanism. Methods The H9 c2 cardiac myocytes were randomly divided into five groups:control group ( C group) , hypoxia/reoxy-genation group ( H/R group) , NGF group ( N group) , NGF+LY294002 group ( N+L group) and LY294002 group( L group) . Each group received the correspond-ing treatment. Cell survival rate was tested by cell counter kit-8 methods. Apoptotic rate was evaluated by propidium iodide ( PI ) staining and flow cytometry (FCM). The levels of Caspase-12, p-Akt/Akt were e-valuated by Western blot. Results The NGF group could significantly protect the H9 c2 cardiac myocytes under the hypoxia / reoxygenation injury with increased cell survival rate. It also decreased the apoptotic per-centage, upregulated the level of p-Akt/Akt and inhib-ited the expression of Caspase-12 . As the specific in-hibitor of PI3k receptor, LY294002 decreased the level of p-Akt. Conclusion NGF has the effect of anti-ap-optosis on H9 c2 cardiac myocytes exposed to hypoxia /reoxygenation injury via PI3k-Akt signal pathway.