RESUMO
OBJECTIVE： To study the improvement effects and its mechanism of erythropoietin derivative helix B surface peptide （HBSP） on epirubicin-induced myocardial injury in rats. METHODS： SD rats were randomly divided into control group， model group， erythropoietin （EPO） group and HBSP group， with 10 rats in each group. Except for control group， other groups were given epirubicin 2.5 mg/kg intraperitoneally， once a week， for consecutive 6 weeks to induce myocardial injury model. EPO group and HBSP groups were given rhEPO 5 000 u/kg or HBSP 60 μg/kg intraperitoneally， 3 times a week （one day before medication， first day and third day after medication of epirubicin）， for consecutive 6 weeks. At the beginning of the first administration， the rats were weighed at the 11th week. The cardiac function was measured by echocardiography [left ventricular end-diastolic diameter （LVIDd）， ejection fraction （EF）， fractional shortening （FS） and cardiac output（CO）]. The serum levels of troponin I （cTnI） and amino-terminal B-type natriuretic peptide （NT-proBNP） were determined by ELISA. mRNA expression of PI3K and Akt in myocardial tissue was detected by RT-PCR. The protein expression of p-PI3K and p-Akt in rat myocardium were detected by Western blot. RESULTS： During research period， two rats died in model group， one in EPO group and none in HBSP group. Compared with control group， body weight， the levels of EF， FS and CO were decreased significantly in model group， while the contents of LVIDd and cTnI， NT-proBNP were increased significantly； mRNA expression of PI3K and Akt as well as protein expression of p-PI3K and p-Akt were decreased significantly， above differences were statistical significant （P＜0.05）. Compared with model group， body weight， the levels of EF， FS and CO were increased significantly in EPO group and HBSP group， while the contents of LVIDd and cTnI， NT-proBNP were decreased significantly； mRNA expression of PI3K and Akt as well as protein expression of p-PI3K and p-Akt were increased significantly， above differences were statistical significant （P＜0.05）. Compared with EPO group， the contents of cTnI and NT-proBNP were decreased significantly in HBSP group， with statistical significance （P＜0.05）. CONCLUSIONS： HBSP can improve myocardial injury in rats as much as EPO， and has less toxity. Their mechanism may be related to the activation of PI3K/Akt signaling pathway.
RESUMO
Objective To evaluate the effects of different time courses and depths of acute normovolemic hemodilution (ANH) with hematocrit (Hct) on injury to the mucous membrane of small intestines in rabbits.Methods Thirty-two adult rabbits,weighing 2.0-2.5 kg,were randomly divided into 4 groups (n=8 each) using a random number table:control group (group C),Hct 18％ group (H1 group),Hct 15％ group (H2 group) and Hct 12％ group (H3 group).The animals were anesthetized with iv 20％ urethane 4 ml/kg,tracheostomized and mechanically ventilated.Blood samples were taken from the left femoral artery.Blood withdrawn from the femoral artery =2 ×body weight× body fluid per kilogram × (initial Hct-target Hct) ÷ (initial Hct+target Hct),and was simultaneously replaced with the equal volume of 6％ hydroxyethyl starch 130/0.4 infused over 30 min via the left femoral vein until the target Hct was achieved in H1,H2 and H3 groups.At 30 min of stabilization after puncture (T0) and 2,4 and 8 h after ANH (T1-3),blood samples were obtained from the superior mesenteric artery and vein for blood gas analysis and for determination of plasma concentrations of tumor necrosis factor-α (TNF-α) in the superior mesenteric vein.Oxygen extraction rate (ERO2) was calculated.Small intestinal mucosal tissues were obtained at T3 to observe the pathological changes with light microscope.Results Compared with those at T0,the plasma concentrations of TNF-α at T3 and ERO2 at T1-3 were significantly increased in H1 group,and the plasma concentrations of TNF-α at T3 and ERO2 at T1-3 were increased in H2 and H3 groups.The injury to the mucous membrane of small intestine was mild in group H1,and was severe in H2 and H3 groups.Conclusion ANH performed with 6％ hydroxyethyl starch causes injury to the mucous membrane of small intestine when Hct is 18％ and the time course ≥ 8 h,and when Hct ≤ 15％ and the time course ≥ 2 h in the rabbits.
RESUMO
Objective To compare the efficacy of different target concentrations of etomidate in combination with midazolam,fentanyl and rocuronium used to induce anesthesia for tracheal intubation.Methods Eighty ASA Ⅰ or Ⅱ and Mallampati Ⅰ or Ⅱ patients of both sexes,aged 25-50 yr,weighing 57-76 kg,scheduled for elective non-cardiac surgery under general anesthesia,were randomly allocated into 4 groups according to the target effect-site concentration of etomidate (n =20 each) ∶ 0.5 μg/ml group (group E0.5),0.7 μg/ml group (group E0.7),0.9μg/ml group (group E0.9) and 1.1 μg/ml group (group E1.1).The patients were unpremedicated.Anesthesia was induced with midazolam 0.05 mg/kg,fentanyl 3 μg/kg,rocuronium 0.6 mg/kg and etomidate given by target-controlled infusion.When the effect-site concentration of etomidate reached 0.5,0.7,0.9 or 1.1 μg/ml,endotracheal intubation was performed.Auditory evoked potential index was recorded before induction of anesthesia (baseline),immediately before intubation,during insertion of the laryngoscope,and at 1,3 and 5 min after intubation.Myoclonus,injection pain,the requirement for vasoactive agents and burst suppression (BS) were recorded during induction of anesthesia.Results Compared with group E0.5,the requirement for urapidil was significantly decreased in group E0.7,the requirement for esmolol and urapidil was significantly decreased and the incidence of BS was increased in group E0.9,the requirement for esmolol and urapidil was significantly decreased,and the requirement for atropine and ephedrine and incidence of BS were increased in group E1.1 (P ＜ 0.05).The incidence of BS was significantly higher in group E0.9,and the requirement for atropine and incidence of BS were significantly higher in group E1.1 than in group E0.7 (P ＜ 0.05).The incidence of BS was significantly higher in group E1.1 than in group E0.9 (P ＜ 0.05).There was no significant difference in auditory evoked potential index and incidences of myoclonus and injection pain among the four groups (P ＞ 0.05).Conclusion The optimum target concentration of etomidate is 0.7μg/ml when combined with midazolam,fentanyl and rocuronium used to induce anesthesia.
RESUMO
Objective To evaluate the accuracy of auditory evoked potential index (AAI) in monitoring the anesthetic depth during isoflurane anesthesia.Methods Thirty ASA Ⅰ or Ⅱ patients aged 18-55 years and undergoing elective surgery under general anesthesia were enrolled in this study. The patients were unpremedicated. Anesthesia was induced with midazolam 0.05 mg/kg, fentanyl 3 μg/kg and propofol 1 mg/kg. Tracheal intubation was facilitated with recuronium 0.1 mg/kg. The patients were mechanically ventilated (VT:40 mm Hg. Anesthesia was maintained with isoflurane inhalation and intermittent intravenous boluses of vecuronium. Isoflurane was started with high-flow (FGF, 3 L/min) for 12 min followed by low-flow (LGF, 0.5 L/min). The inspired isoflurane concentration was set at 3%. The electrocardiogram (ECG), mean arterial pressure (MAP), heart rate (HR), pulse oxygen saturation (SpO2), end-tidal isoflurane concentration and AAI were continuously monitored during anesthesia and recorded before induction of anesthesia (baseline, To ), immediately after induction (T1), immediately before isoflurane inhalation (T2), at 3 min(T3), 6 min (T4), 9 min (T5) and 12 min (T6) during high-flow wash-in and at the end-tidal isoflurane concentrations of 0.8 MAC (T7), 1.0 MAC (T8) and 1.3 MAC (T9) during low-flow inhalation of isoflurane, respectively.Results AAI decreased gradually while the end-tidal isoflurane concentration increased during high-flow wash-in. And AAI was negatively correlated with the end-tidal isoflurane concentrations ( r = -0.896, P ＜ 0.01 ) during low-flow inhalation of isoflurane anesthesia.
RESUMO
Objective To study the extracellular signal-regulated kinase 1/2(ERK1/2) expression of renal cells in epilepsy rats induced by kainic acid,and elucidate the mechanism of renal injury caused by epilepsy.Methods 70 male Wistar rats were randomly divided into two groups:epilepsy group and control group,35 rats in each group.Rat epilepsy model was prepared by injection of kainic acid into amygdala under three-dimensional positioning devices.At different time points(0,2,6,12 and 24 h) after epilepsy spasm,the renal tissue specimens were immediately prepared for immunohistochemistry.The ERK1/2 expression of rat renal cells was calculated and compared with control group.Results The ERK1/2 expression(gray value) of renal tubular epithelial cells in epilepsy rats began to increase gradually after epilepsy spasm.It reached peak at 6 h after epilepsy spasm.The ERK1/2 expression of renal tubular epithelial cells in epilepsy rats was significantly higher than at 0 h(P0.05).There were no major pathological changes in kidney of rats with epilepsy stained with HE.Conclusion ERK1/2 activation may have important role in the renal injury caused by epilepsy.Inhibition of the activation of ERK1/2 may lead to the renal protection.
