[Effects of mitochondrial division inhibitor on neurological function and neuronal apoptosis in rats after cardiopulmonary resuscitation].

OBJECTIVE: To investigate the effects of mitochondrial division inhibitor 1 (mdivi-1) in rats after cardiopulmonary resuscitation (CPR) and its mechanism. METHODS: Fifty Sprague-Dawley (SD) rats were randomly (random number table) divided into sham group (n = 8), cardiac arrest (CA) model group (n = 14), dimethyl sulfoxide post-treatment control group (DMSO group, n = 14), and mdivi-1 post-treatment group (mdivi-1 group, n = 14). Asphyxial CA was reproduced in animals, and they were resuscitated by CPR. In the mdivi-1 group or DMSO group, the animals were given mdivi-1 (1.2 mg/kg) or DMSO (0.1%) intravenously after restoration of spontaneous circulation ( ROSC ). The neurological functions were assessed using neurological deficit score (NDS) determined at 24, 48 and 72 hours after CPR. The brain tissues were harvested at 72 hours after CPR. The histopathologic changes were assessed by hematoxylin and eosin (HE) staining, and the normal neuron was counted. The neuronal apoptosis was assessed with terminal dexynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and the expressions of cytochrome C (Cyt-C) protein in mitochondria and cytoplasm from hippocampus were determined by Western Blot. RESULTS: NDS in all experiment groups was gradually increased after CPR, and they were significantly lower than those of the sham group at 24, 48, and 72 hours (51.5 ± 3.7 vs. 80.0 ± 0.0, 59.3 ± 3.6 vs. 80.0 ± 0.0, 66.7 ± 2.6 vs. 80.0 ± 0.0, all P < 0.05). The number of normal pyramidal neurons in the hippocampal CA1 region was markedly reduced (cells/HP: 4.4 ± 1.1 vs. 23.1 ± 4.0, P < 0.05), the apoptotic index was significantly increased [(86.9 ± 6.9)% vs. (3.4 ± 0.8)%, P < 0.05], the expressions of Cyt-C in mitochondria were significantly decreased (A value: 0.46 ± 0.18 vs. 1.00 ± 0.00, P < 0.05), and the expressions of Cyt-C in cytoplasm were significantly up-regulated (A value: 6.65 ± 0.21 vs. 1.00 ± 0.00, P < 0.05). Compared with the CA group, NDS at 24 hours and 48 hours in mdivi-1 group was slightly increased (55.2 ± 3.3 vs. 51.5 ± 3.7, 64.7 ± 2.4 vs. 59.3 ± 3.6, both P > 0.05), and it was significantly increased at 72 hours (74.5 ± 2.3 vs. 66.7 ± 2.6, P < 0.05), the number of normal pyramidal neurons in the hippocampal CA region was markedly increased (cells/HP: 16.2 ± 2.4 vs. 4.4 ± 1.1, P < 0.05), the apoptotic index was dramatically reduced [(42.3 ± 3.9 )% vs. (86.9 ± 6.9 )%, P < 0.05], the expressions of Cyt-C in mitochondria were significantly increased (A value: 0.83 ± 0.22 vs. 0.46 ± 0.18, P < 0.05), and the expressions of Cyt-C in cytoplasm were significantly decreased (A value: 3.84 ± 0.47 vs. 6.65 ± 0.21, P < 0.05). There was no statistically significant difference in above indexes between CA group and DMSO group. CONCLUSION: By inhibiting mitochondrial Cyt-C apoptotic pathway to reduce neuronal apoptosis in rats after CA-CPR, mdivi-1 can improve brain function after CPR.

Effects of carbon monoxide releasing molecule-2 on post-resuscitation myocardial dysfunction / 中华急诊医学杂志

Objective To investigate the protective role of carbon monoxide releasing molecule-2 (CORM-2) in post-resuscitation myocardial dysfunction (PRMD) in rat models of cardiopulmonary resuscitation (CPR).Methods Cardiopulmonary resuscitation model was established after cardiac arrest induced by ventricular fibrillation.Male healthy Sprague-Dawley (SD) rats were randomly (random number) divided into 4 groups according to random number table:control group,CORM-2 group,inactive CORM-2 (iCORM-2) group and Sham group,in which the equal volume (1 mL) of 0.2％ DMSO,50 μmol/kg CORM-2,50 μmol/kg iCORM-2 and 0.2％ DMSO were respectively administered into the rats of these groups after resuscitation.The ejection fraction (EF) of left ventricle and myocardial performance index (MPI) were measured to detect the myocardial function by echocardiography at 12 hours after resuscitation.Mitochondrial respiration was assessed with Clark oxygen electrode at the same time.Western blot was used to determine the ratio of mitochondrial cytochrome c (cyt c) to cytoplasmic cyt c as well as caspase-3 level.Multiple comparisons were made by analysis of variance.Results Compared with the control group,higher EF and MPI,higher state Ⅲ respiration rate and respiratory control rate (RCR) of mitochondria,and decreased ratio of mitochondrial cytc/cytoplasmic cyt c and lower caspase-3 level were observed in the CORM-2 group (P ＜ 0.05).However,there were no significant differences in above biomarkers found between iCORM-2 group and control group (P ＞ 0.05).Conclusions The CO released from CORM-2 might improve mitochondrial respiration and PRMD by inhibition of myocardial apoptosis via a mitochondrial pathway.

Short period of mild hypothermia improves resuscitation outcome in a porcine model of prolonged ventricular fibrillation / 中华急诊医学杂志

Objective To investigate the resuscitation outcome after a short period of mild hypothermia in porcine model of prolonged ventricular fibrillation (VF).Methods Fourteen male healthy domestic swine weighting 34 to 36 kg were used.VF was induced electrically and maintained untreated for 11 mins,followed by manual cardiopulmonary resuscitation (CPR) procedure.Two investigators initiated chest compression and bag-valve mask ventilation in pattern of 2 min rotation.A biphasic wave of 120 J electric defibrillation (ED) was attempted 6 mins after CPR.If there was no return of spontaneous circulation (ROSC),CPR was restored and ED was delivered when necessarily.Resuscitation was considered unsuccessful if absence of ROSC for 12 mins.However,if ROSC occurred,animals were randomly (random number) diveded into normothermia (NT) group and hypothermia treatment (CH) group.Animals in CH group were immediately cooled by using intravenous infusion of ice-cold saline and surface cooling.Core temperature was reduced to 32-34 degrees centigrade within 120 mins and maintained at this level for 2 h.Active rewarming was completed within 2 h until baseline body temperature was reached.Data of hemodynamic variables,blood-gas analysis and blood lactate before VF of two groups were recorded.Meawhile,cardiac output (CO),heart rate and Tc after ROSC were recorded.Neurological defect scores (NDS) were evaluated every 24 h until 96 h after ROSC.Variables were compared using either Fisher test or repeated measures analysis of variance,followed by Bonferroni for multiple comparisons.A two-sided P value ＜0.05 was regarded statistically significant.Results There was no significant difference in body weight,mean arterial pressure,CO,pH,pressure of end-tidal carbon dioxide (ETCO2) and lactate between groups before VF.In the period of CPR,there were also no significant difference in total resuscitation time,first shock success rate,ROSC rate,shock ROSC rate,total number of shock and doses of epinephrine.However,animals in CH group survived longer time than that in NT groups [(96.00 ± 0.00) hvs.(49.71 ±43.65) h,P=0.031].Meanwhile,the survival rate of 96 h was significantly higher in CH than that in NT (P ＜ 0.05).For neurological function,there was a obviously better NDS in CH group than that in NT group within ROSC 96 h (P ＜ 0.05).Conclusion Even a short duration of 2 hour mild hypothermia could improve resuscitation outcome in porcine model of 11 minute VF.

Suppression of inflammatory damage to the brain after global cerebral ischemia by transplanted mesenchymal stem cells via secretion of TSG-6

Objective: Numerous studies have shown that bone marrow-derived mesenchymal stem cells (MSCs) enhance neurological recovery after cerebral ischemia. However, the mechanisms are still not clear. The present study aimed to investigate the beneficial effects of MSCs on global cerebral ischemia induced by cardiac arrest (CA) and the underlying mechanisms. Methods: Rats subjected to asphyxial CA were injected intravenously with MSCs (5×106 ) at 2 hours after resuscitation. Whole brain histopathologic damage scores (HDS) were assessed by histopathology at 3 and 7 days after resuscitation. The distribution of donor MSCs in the brain was evaluated. The expression of tumor necrosis factor-α-induced protein 6 (TSG-6) and pro-inflammatory cytokines in cerebral cortex was assayed. After intravenous infusion of TSG-6 siRNA-MSCs, HDS and pro-inflammatory cytokines were reevaluated at 7 days after resuscitation. Results: Intravenously administered MSCs significantly reduced whole brain HDS after global cerebral ischemia. Immunofluorescence microscopy revealed that donor MSCs were primarily found in cerebral cortex and expressed TSG-6. MSCs treatment significantly increased the expression of TSG-6 and reduced the expression of pro-inflammatory cytokines in cerebral cortex. In addition, intravenous infusion of TSG-6 siRNA-MSCs failed to attenuate brain inflammation. Conclusion: Systemically administered MSCs reduced inflammatory damage to brain in rats with global cerebral ischemia via secretion of TSG-6.

The mobilization of stem cells promote the recovery of the ischemia brain injury after cardiopulmonary resuscitation / 中华急诊医学杂志

Objective To explore the therapeutic potential and mechanism of stem cells mobilized by granulocyte colony-stimulating factor (G-CSF) and AMD3100 to repair global cerebral ischemia injuries in a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR).Methods Cardiac arrest was induced by asphyxia.Fifty-six SD rats were randomly assigned into four groups:G-CSF group,G-CSF + AMD3100 group,CPR control group and sham operated group.The animals were sacrificed at 3d and 6d after CPR respectively.The neurological status and morphological changes of damaged cerebrum,the apoptosis of nerve cells and vascular endothelial growth factor (VEGF) expressed in brain tissue and capillary density in hippocampus and temporal lobe cortex were measured and analyzed by means of neurological deficit score (NDS),adhesive tape removal test (TRT),ELISA,MRI and immunofluorescence.Results NDS in G-CSF + AMD3100 group (61.4 ± 10.7) was significantly higher than that in CPR control group (49.9 ± 10.4) at 3 d after CPR (P ＜0.05).And less time consumption for TRT found in G-CSF + AMD3100 group (85.5 ±28.9) s rather than was in CPR control group (148.1 ± 23.8) s and G-CSF group (118.5 ± 30.4) s (P ＜ 0.05).The severity of cerebral injury assessed by MRI was significantly milder at both 3 d and 6 d in the two stem cell mobilization groups.The apoptosis rate of nerve cells in G-CSF + AMD3100 group (0.23 ± 0.06) was significantly lower than that in G-CSF group (0.34 ±0.08) at 3 d after CPR,and that in both stem cell mobilization groups was lower than that in CPR control group (0.44 ± 0.09) (P ＜ 0.05).At 3 d and 6 d after CPR,the levels of VEGF in brain tissue were (106.2 ±23.3) pg/mL and (79.9 ± 18.4) pg/mL in G-CSF + AMD3100 group,and were (50.6 ± 13.7) pg/mL and (73.9 ± 16.6) pg/mL in G-CSF group,which were both significantly higher than that in CPR control group (23.1 ± 10.2) pg/mL and (36.2 ± 12.8) pg/mL (P ＜0.05).At 3 d after CPR,the cerebral capillary density (351.8 ±67.9) branches in every high power field (A/HPF) was significantly higher in G-CSF + AMD3100 group than that (301.4 ± 77.3) A/HPF in G-CSF group and (250.4 ± 48.0) A/HPF in CPR control group (P ＜ 0.05).The cerebral capillary density in G-CSF group elevated to (348.4 ±76.7) A/HPF at 6 d after CPR which was significantly higher than that at 3 d (P ＜0.05),and there was no difference between that at 3 d and 6 d in G-CSF + AMD3100 group.Conclusions The mobilization stem cells improve the impaired neurological function.The increased expression of VEGF in brain tissue,the neo-vascularization promoted by the mobilized stem cells and the inhibition of nerve cell apoptosis may be associated with the protective effects of the stem cell mobilization.

Effects of mitochondrial division inhibitor on neurological function and neuronal apoptosis in rats after cardiopulmonary resuscitation / 中华危重病急救医学

Objective To investigate the effects of mitochondrial division inhibitor 1 (mdivi-1) in rats after cardiopulmonary resuscitation (CPR) and its mechanism.Methods Fifty Sprague-Dawley (SD) rats were randomly (random number table) divided into sham group (n =8),cardiac arrest (CA) model group (n =14),dimethyl sulfoxide post-treatment control group (DMSO group,n =14),and mdivi-1 post-treatment group (mdivi-1 group,n =14).Asphyxial CA was reproduced in animals,and they were resuscitated by CPR.In the mdivi-1 group or DMSO group,the animals were given mdivi-1 (1.2 mg/kg) or DMSO (0.1％) intravenously after restoration of spontaneous circulation (ROSC).The neurological functions were assessed using neurological deficit score (NDS) determined at 24,48 and 72 hours after CPR.The brain tissues were harvested at 72 hours after CPR.The histopathologic changes were assessed by hematoxylin and eosin (HE) staining,and the normal neuron was counted.The neuronal apoptosis was assessed with terminal dexynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining,and the expressions of cytochrome C (Cyt-C) protein in mitochondria and cytoplasm from hippocampus were determined by Western Blot.Results NDS in all experiment groups was gradually increased after CPR,and they were significantly lower than thoseo.f the sham group at 24,48,and 72 hours (51.5±3.7 vs.80.0±0.0,59.3±3.6 vs.80.0±0.0,66.7±2.6 vs.80.0±0.0,all P ＜ 0.05).The number of normal pyramidal neurons in the hippocampal CA1 region was markedly reduced (cells/HP:4.4± 1.1 vs.23.1 ± 4.0,P ＜ 0,05),the apoptotic index was significantly increased [(86.9 ± 6.9)％ vs.(3.4 ± 0.8)％,P ＜ 0.05],the expressions of Cyt-C in mitochondria were significantly decreased (A value:0.46±0.18 vs.1.00±0.00,P ＜ 0.05),and the expressions of Cyt-C in cytoplasm were significantly up-regulated (A value:6.65±0.21 vs.1.00±0.00,P ＜ 0.05).Compared with the CA group,NDS at 24 hours and 48 hours in mdivi-1 group was slightly increased (55.2 ± 3.3 vs.51.5 ± 3.7,64.7 ± 2.4 vs.59.3 ± 3.6,both P ＞ 0.05),and it was significantly increased at 72 hours (74.5±2.3 vs.66.7 ± 2.6,P ＜ 0.05),the number of normal pyramidal neurons in the hippocampal CA1 region was markedly increased (cells/HP:16.2±2.4 vs.4.4± 1.1,P ＜ 0.05),the apoptotic index was dramatically reduced [(42.3 ± 3.9)％ vs.(86.9 ± 6.9)％,P ＜ 0.05],the expressions of Cyt-C in mitochondria were significantly increased (A value:0.83 ± 0.22 vs.0.46 ± 0.18,P ＜ 0.05),and the expressions of Cyt-C in cytoplasm were significantly decreased (A value:3.84±0.47 vs.6.65±0.21,P ＜ 0.05).There was no statistically significant difference in above indexes between CA group and DMSO group.Conclusion By inhibiting mitochondrial Cyt-C apoptotic pathway to reduce neuronal apoptosis in rats after CA-CPR,mdivi-1 can improve brain function after CPR.

Comparison of myocardial injures between asphyxia and ventricular fibrillation models of cardiac arrests / 中华急诊医学杂志

Objective To compare the difference in cardiac injuries between asphyxia and ventricular fibrillation modes in different periods after cardiac arrest (CA).Methods The model was established in Cardiopulmonary Resuscitation Lab,Sun Yat-sen University.A total of 35 male SD rats were used to produce the asphyxia or ventricular fibrillation (VF) cardiac arrest models randomly.Both of the two modes were induced 8 minutes cardiac arrest.The myocardial HE stains,mitochondrial respiratory control ratio (RCR),and echocardiography were observed at 4 h,24 h and 72 h after ROSC (restoration of spontaneous circulation).The results were expressed as (-x ± s),t test was performed to compare between two groups,and one way analysis of variance was used to compare multiple groups.P ＜ 0.05 was considered as significant difference.Results HE stains showed damages were more serious in the VF mode than in asphyxia mode at 4 h,and both of them had a disorderly-arranged myocardium at 72 h.RCR in VF mode became worse at 4 h,and RCR resumed at 24 h in both modes without significant difference compared with the sham operated rats.The echocardiography showed VF mode had a lower left ventricular ejection fraction (LVEF) than asphyxia mode at 4 h (29.68％ vs.42.16％,P =0.03),and there was no difference in LVEF between VF mode and the sham operated rats at 24 h,however no difference in LVEF between the asphyxia and sham operated rats at 72 h.Both of them had a thicker left ventricular anterior wall than the sham operated rats at 72 h (2.41 mm vs.1.72 mm,P=0.013; 2.61 mmvs.1.72 mm,P=0.007),and there was no significant difference between them.Conclusions The ventricular fibrillation mode has a more severe injuries in early period,but it recovers sooner than asphyxia one.Both of two groups get compensatory left ventricular hypertrophy in later period of ROSC.

Expression of tumor necrosis factor-α-induced protein 6 after transplantation of mesenchymal stem cells in a rat model of cardiopulmonary resuscitation / 中华急诊医学杂志

Objective To investigate the effects of bone marrow mesenchymal stem cells (MSCs)treatment on TSG-6 in a rat model of cardiopulmonary resuscitation (CPR).Methods Sprague Dawley (SD) rats were randomly (random number) divided into sham group,phosphate buffer solution (PBS)-treated group and MSCs-treated group.Animals were subjected to asphyxial cardiac arrest followed by CPR.In PBS-treated group or MSCs-treated group,animals were injected intravenously with PBS or MSCs at 2h after resuscitation.Neurological deficit scores (NDS) were assessed at 1,3 and 7 d after CPR.Serum S-100B was assayed using enzyme linked immunosorbent assay (ELISA).Immunofluorescence was performed to detect donor MSCs and the expression of TSG-6 in brain.TSG-6 and proinflammatory cytokines in brain were assayed using real time reverse transcription-polymerase chain reaction (RT-PCR).Western blot analysis was performed to measure the levels of neutrophil elastase (NE) in brain.Multiple comparisons were made by analysis of variance.Results At 3d and 7d,MSCs-treated group demonstrated higher NDS than PBS-treated group (P ＜ 0.01),and serum S-100B levels significantly reduced in MSCs-treated group compared with PBS-treated group (P ＜ 0.01).DAPI-labeled MSCs migrated into the ischemic brain and some DAPI + cells colocalized with TSG-6.Compared with PBS-treated group,MSCs treatment significantly up-regulated the expression of TSG-6 and reduced the expression of NE and proinflammatory cytokines in brain at 3 d and 7 d after CPR (P ＜ 0.05).Conclusion Systemically administered MSCs suppressed inflammatory responses in brain after CPR and improved neurological function in rats possibly via induction of TSG-6.

Studying the establishment of rat model of asphyxial cardiac arrest and the efficacy of CPR / 中华急诊医学杂志

Objective To study the establishment of rat model of asphyxia-cardiac arrest and efficacy of CPR in order to find the length of optimum time of asphyxia to cause injury.Methods One hundred and twenty-six male Sprague-Dawley rats were randomly (random number) divided into sham operation group and experimental groups.Cardiac arrest was induced by asphyxiation after intravenous injection of vecuronium bromide.The experimental groups were assigned into AP4 (four-minute asphyxia period),AP6 and AP8 subgroups in accordance with different lengths of time of asphyxia subjected to.In these groups,CPR,including pre-cordial compression and synchronized mechanical ventilation,was initiated 4,6 and 8 min after asphyxia-induced cardiac arrest,respectively.The successful ratio of resuscitation and hemodynamic variables were recorded.Brain water content,neural deficit scores (NDS),imaging changes on MR,pathological changes of brain tissue and neuronal apoptosis were evaluated at 1 d,3 d and 7 days after ROSC.All the data were analyzed by single-factor analysis of variance or Chi-square test.P ＜ 0.05 was considered statistically significant.Result The lowest NDS occurred at 1 d after ROSC,brain water content and imaging changes on MR were most obvious at 3 d after ROSC,while pathological changes of brain tissue and neuronal apoptosis increased and reached the peak at 7d after ROSC.The survival rates after 24 hours of AP4,AP6 and AP8 groups were 85％,75％ and 45％,respectively.The rate of ROSC and survival rate of AP8 group were significantly lower than those of other groups (P ＜0.01).The longer time of asphyxia the severer pathological changes of brain tissue,brain edema,neural deficit,and magnetic resonance imaging changes in all experimental groups.As compared to other groups,the brain damage index of AP8 group was most serious,while that of AP6 group was moderate.Conclusions The rat model following asphyxia-induced cardiac arrest and cardiopulmonary resuscitation was established successfully.From the evidence of survival rate and damage grade of brain tissue,asphyxia for 6 min may be the rational length of ischemic time in this model.

The differences in brain damage between asphyxial nd ventricular fibrillation cardiac arrests

Objective: Asphyxia and ventricular fibrillation are the two most prevalent causes of cardiac arrest. The study investigated the differences in brain damage after cardiac arrest between asphyxial and ventricular fibrillation cardiac arrests in rats. Methods: Male healthy Sprague-Dawley rats were randomly assigned to the asphyxial group (cardiac arrest of 6 min, n=15), ventricular fibrillation group (cardiac arrest of 6 min, n=15) and sham group (n=5). Neurologic deficit scores and tape removal test were evaluated at 1, 3 and 7 days after cardiopulmonary resuscitation from three groups. Serum S-100B and brain histopathologic damage scores were also examined. Results: There were no differences in neurologic performance at 1, 3 and 7 days after cardiopulmonary resuscitation between the asphyxial group and ventricular fibrillation group (P>0.05, respectively). Serum S-100B level was higher in the asphyxial group at 1, 3 and 7 days, compared with the ventricular fibrillation group (P<0.05, respectively). There were significantly higher histopathologic damage scores at 1, 3 and 7 days in the asphyxial group compared with the ventricular fibrillation group (P<0.05, respectively). Conclusion: Asphyxial cardiac arrest has worse morphologic brain damage compared with ventricular fibrillation cardiac arrest, but the functional brain damage caused by asphyxial cardiac arrest is similar to that caused by ventricular fibrillation cardiac arrest.

Study of the effects of mild hypothermia on improvement of cardiomyocyte contractility after ischemia-reperfusion in rats / 中华急诊医学杂志

Objective To study the effects of mild hypothermia on cardiomyocyte contractility improvement after ischemia-repeffusion injury and on the preservation of well-functioning mitochondrial respiratory capability.Methods A total of 50 newborn SD rats 1 ～ 2 days after delivery were sacrificed and their hearts taken to preserved in 4 ℃ cold D-hanks buffer solution with 0.12％ pancreatic proteinase and collagenase and then processed with 37 ℃ water bath to collect the cardiomyocytes cultured in DMEM medium with 10％ FBS for 5 days.The cardiomyocytes of rats were subjected to ischemia/reperfusion,in vitro,by oxygen and glucose deprivation(OGD)/oxygen and glucose restoration(OGR).The cardiomyocytes of rats after ischemia/reperfusion were divided into three groups:control group,hypothemia group and normothermia group.Contractile frequency and velosity were determined before OGD and 0 h,0.5h,1 h,1.5 h and 2 h after OGR.Ultrastructure changes of cardiomyocytes and mitochondrion were observed under transmission electron microscope(TEM)0 h and 2 h after OGR as well as assessment ot respiratory rate and respiratory control rate(RCR)with Clark oxygen electrode in each group.All data were analyzed with statistical software of SPSS 13.0.Results Contractile function of cardiomyocytes in hypothermia group and normothermia group declined to nadir at 0 h after OGR(P =0.000)and the contractile function of cardiomyocytes in hypothermia group was improved one hour later,compared with the normothermia group(P =0.000).Obvious swelling of mitochondrion was observed under TEM in normothermia group with little alteration after OGR.The RCR assessments indicated respiratory function in normothermia group was impaired after OGR(P =0.000)and this may be responsible for contractility dysfunction.Conclusions Mild hypothemia used after ischaemia can optimize the contractility of cardiomyocytes after a normothermia OGR,and the well-functioning respiratory capability of mitochondrion may be preserved in this process.

Comparison of cardiac arrest induced by ventricular fibrillation or induced by asphyxia in rats / 中华急诊医学杂志

Objective To compare the changes of physiological parameters after cardiac arrest caused by asphyxia with that of cardiac arrest induced by ventricular fibrillation in rats and assess the values of the parameters on predicting ROSC and 24 h survival rate. Method Two groups of Sprague-Dwaley rats, which randomly (ramdom number) included 30 animals in each group, were investigated. Cardiac arrest were induced by asphyxia (AS group) or ventricular fibrillation(VF group). PETCO2, aortic pressure, left ventricular pressure and ECG of limb lead Ⅱ were recorded continuously, dP/dt4o was calculated with the windaq software. The parameters were compared between the two groups at baseline, precordial compression(PC) 10 s, PC 1 min, PC 3 min, ROSC 1 h and ROSC 2 h. The relations were explored between the parameters and ROSC/24 h survival rate. Results PETCO2,aortic pressure, left ventricular pressure and ECG have distinctive changes in the two groups. In group VF, PETCO2 of ROSC rats at BL, PC 1 min and PC 3 min were higher than those of Non-ROSC rats (P ＜ 0.05); PETCO2of 24 h survival rats at ROSC 1 h and ROSC 2 h were higher than those of 24 h death rats (P ＜ 0.05), which were not observed in the group AS. dP/dt40 and - dP/dt40 at ROSC 1 h and ROSC 2 h in group VF were higher than those in group AS (P ＜ 0.05). Conclusions Physiological parameters after cardiac arrest caused by asphyxia or that of cardiac arrest induced by ventricular fibrillation in rats have unique features respectively. PETCO2 in cardiac arrest caused by ventricular fibrillation may predict ROSC and 24 h survival rate. Researchers have to select the appropriate cardiac arrest model according their research purposes and clinical requirments.

Effect of heme oxygenase-1 on hypoxia-reoxygenation injury in cultured neonatal rat cardiomyocytes / 中华麻醉学杂志

Objective To investigate the effect of heme oxygenase-1 (HO-1) on hypoxia-reoxygenation (H/R) injury in cultured neonatal rat cardiomyocytes. Methods Primary cultured neonatal rat cardiomyocytes were randomly divided into4 groups: Ⅰ control group (group C), Ⅱ H/R group, Ⅲ hemin group and Ⅳ hemin+zinc protoporphyrin (ZnPP) group. In group H/R, the cardiomyocytes were exposed to 2 h of hypoxia followed by 6 h of reoxygenation. Hemin was added to the culture medium with a final concentration of 20 μmol/L 24 h before hypoxia and immediately before hypoxia in group hemin. Hemin and ZnPP were added to the culture medium with final concentrations of 20 μmol/L 24 h before hypoxia and immediately before hypoxia in group Henin + ZnPP. The cells were incubated in 35 mm culture dishes (2 ml in each dish) and 50 ml culture flasks (3 ml in each flask)(45 dishes and 3 flasks in each group). The HO-1 expression, cell survival rate, LDH activity, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were detected after the end of reoxygenation. Results Compared with group C, the LDH activity, MDA level and HO-1 expression were significantly increased, while the cell survival rate and SOD activity decreased in the other three groups ( P ＜ 0.05). Compared with group H/R,the LDH activity and MDA level were significantly decreased, while the HO-1 expression, cell survival rate and SOD activity increased in group hemin ( P ＜ 0.05 ), but no significant change was found in group hemin + ZnPP (P ＞0.05). H/R injury was obvious in group H/R and hemin + ZnPP, but was significantly attenuated in group hemin. Conclusion HO-1 can protect cardiomyocytes against H/R injury in neonatal rats.

The experimental probe into the construction of oxygen glucose deprivation/reoxygenation model of hippocampal neurons of rat in vitro / 中华急诊医学杂志

Objective To establish the oxygen glucose deprivation (OGD)/reoxygenation experimental model of hippocatnpal neurons of rat in vitro, and to try to identify the length of time for producing optimum injury in this model. Method The primary hippocampal neurons of newborn Sprague-Dawley rats were cultured for 7 days and randomly (random number) divided into a control group and OGD groups. The OGD groups were assigned into 1 h, 2 h, 4 h, 6h, 8 h and 10 h subgroups in accordance with different lengths of time for oxygen glucose deprivation. The neurons of OGD groups were placed into a tri-gas incubator containing 0.5% oxygen and the culture medium was substituted with the glucose-free Earle' s balanced salt solution, simulating cerebral ischemia injury in vivo. The morphology of neurons was observed after reoxygenation for 24 hours. The MIT assay was used to determine the rate of survived cells derived from the value of optical density (OD) of cells. The lactate dehydro-genase (LDH) content in culture medium was detected to evaluate the neuron injury. The apoptotic rate of neurons was measured by using flow cytometry. Dunnett-test and Spearman correlation analysis were used to analyze the data with SPSS version 16.0 soft ware package. Results The morphological damage of neurons in OGD groups aggravated gradually, optical density and cell survival rate decreased (rs= -0.961 and rs = -0.966, P <0.01), and the amount of LDH increased (rs = 0.990, P <0.01) with longer duration of exposure to oxygen glucose deprivation, and the rate of neuron apoptosis increased obviously which was significantly statistical difference in com-parison with the control group (P < 0.05). Under the setting of oxygen glucose deprivation for 6 hours, the apop-tosis rate of neurons approximated to 50% . Conclusions The oxygen glucose deprivation/reoxygenation model of rat's hippocampal neurons in vitro was established successfully. From the findings of morphological changes and apoptosis rate of neurons, the oxygen glucose deprivation for 6 hours may be the suitable length of time for inducing neuron injury in this model.

Preliminary observation of the expressions of SOCS-1 and SOCS-3 in myocardium of patients with sudden cardiac death / 中华急诊医学杂志

Objective To investigate the expressions and clinical significanees of suppressors of cytokine signaling-1 (SOCS-1) and SOCS-3 in myocardium of patients with sudden cardiac death (SCD). Method This study included myocardial autopsy specimens of 24 patients admitted between 2005 and 2006. Of them, 9 cases had the findings of autopsy examination consistent with coronary atberosclerosis (non-myocardial infarction) leading to SCD (non-MI group), 7 patients died of acute myocardial infarction (MI group) and 8 patients died of traffic accidents and trauma The expressions of SOCS-1 mRNA and SOCS-3 mRNA in the myocardium of non-MI and con-trol group were detected by using RT-PCR. The levels of SOCS-1 protein and SOCS-3 protein were detected by us-ing immunohistochemistry. Statistical analysis were performed by using SPSS version 13.0 software and the data were processed with ANOVA test. Results The expressions of SOCS-1 mRNA and SOCS-3 mRNA in non-MI and MI groups were were significantly higher than those in control group (0. 788±0. 101) and (0. 741±0.111) vs.(0.436±0.044) (P <0.01); (0.841±0.092) and (0.776±0.070) vs.(0.454±0.076), P <0.01, re-spectively). The antibody-positive cells of SOCS-1 protein in myocardium of non-MI group and MI group were significantly higher than those in myoeardium of control group (320.00±48.48) and (347.14±70.88) vs.(42.50±10.35) (P < 0.01), respectively. The antibody-positive cells of SOCS-3 protein in myoeardium of non-MI group and MI group were significantly higher than those in myocardium of control group (381.11±59.25) vs.(40.00±10.69), (P < 0.01)and (332.86±111.91) vs. (40.00±10.69), (P =0.001). Conclusions The expressions of SOCS rnRNA and SOCS-3 mRNA in myoeardium of patients with SCD from coronary diseases are significantly increased contributing to the pathogenesis of SCD.

The epidemiological analysis of patients in pre-hospital medical care in large and medium-sized cities in China / 中华急诊医学杂志

Objective To investigate the epidemiological information of patients in pre-hospital medical care for our large and medium-sized cities and probe the patients' characteristic. Method The data in 2008 were exported from the computer databases of 8 large and medium-sized cities' emergency medical centers in our country.The thorough records of data were conducted to statistical analysis. Results ( 1 ) The scheduling time, running time, rescue time, returning time, total time and service radius in the pre-hospital medical care group were 2.16± 1.10(min), 14.01 ±6.82(min), 12.12±5.96(min), 14.08± 6.85(min), 42.34± 20.21(min)and 8.50±4.18(km), and the above parameter in the non-death group were 2.19 ± 1.13(min), 14.15 ± 7.14(min),11.60±6.72(min), 14.92 ±6.89(min), 41.86± 19.53(minutes) and 8.63±4.31(Km), and the above parameter in the death group were 2.10± 1.08(min), 13.68 ± 7.14(min), 25.25 ± 12.34(min), 13.75±6.48(min), 54.74 ± 25.47(min) and 7.86± 3.91(Km), and the above parameter in the non-sudden cardiac death group were2.09± 1.03(min), 13.58±6.78(min), 25.53± 12.34(min), 13.60± 6.54(min), 53.79±23.77(min) and 7.67 ± 3.86(Km), and the above parameter in the sudden cardiac death group were 2.12 ±1.02(min), 14.10±7.05(min), 24.79± 12.08(min), 13.79±6.61(min), 54. 80 ± 25. 36( min) and 7.90±3.92(Km) respectively. The scheduling time, running time, returning time and service radius in the death group were less than those of the non-death group, but the rescue time and total time of the former were more than those of the latter respectively ( P ＜ 0.05 or P ＜ 0. 001 ). The scheduling time and returning time didn' t have significant difference between the sudden cardiac death group and the non-sudden cardiac death group respectively ( P ＞ 0.05), but the running time, total time and service radius of the sudden cardiac death group were more than those of the non-sudden cardiac death group, and the rescue time of the former was less than that of the latter respectively ( P ＜ 0.05 or P ＜ 0.001 ). (2)The patients' amount in pre-hospital medical care group, the non-death group, the death group, the non-sudden cardiac death group and the sudden cardiac death group were at most in first quarter, and the least time slice of patients' amount were 4:00～ 6:00, 4:00～6:00, 4:00～ 6:00, 22:00～ 24:00, 2:00～4:00 respectively, and the most time slice of patients' amount were 20:00～ 22:00, 20:00～22:00, 8:00～ 10:00, 2:00 ～ 4:00, 8:00 ～ 10:00 respectively. (3)In 241 876 cases of pre-hospital medical care group, the patients' amount of trauma was at most, whose age grades was by far among21 ～50, and the others in sequence were nervous system, circulatory system, other group, digestive system, respiratory system and poisoning group respectively, whose age grades in nervous system, circulatory system and respiratory system was by far above 51, especially above 70. The patients' age grades in other group and digestive system had two climax age groups, which the one was 21 ～ 30, and the other was above 70. The patients' age grades in poisoning group was by far among 21 ～ 50, which the patients' amount of acute alcoholism was at the most. (4) In 12 568 cases of death group, the death amount of circulatory system, other group, respiratory system, nervous system and digestive system ranked at the lst,2nd,4th,5th 8th respectively, whose age grades was by far above 51, especially above 70,and the patients' amount of sudden cardiac death was at the most in the death amount of circulatory system. The death amount of trauma and poisoning group ranked at the 3rd, 6th respectively, whose age grades was by far among 21 ～ 50. (5)The total amount, the death amount and the sudden cardiac death amount of male patients were more than those of female patients. (6)The percentage of the death group to the pre-hospital medical care group was 5.20%, and the percentage of the sudden cardiac death group to the pre-hospital medical care group was 1.29%,and the percentage of the sudden cardiac death group to the death group was 24.87 %, and the percentage of the sudden cardiac death group to the circulatory system group was 67.33 %. Conclusions ( 1 )The trauma and the sudden cardiac death are the overriding reason of disease and the overriding reason of death in our large and medium-sized cities respectively. (2) It is very important to cut the death rate of the middle-old age patients by strengthening prevention and cure of cardiovascular and cerebrovascular diseases, discerning the critical illness early and improving the level of pre-hospital medical care. (3)It is a strong method to decrease the total amount and the death amount of the trauma, especially in traffic accident, by strengthening safety in production, observing traffic regulation and enhancing the legal awareness.

Effects of δ-opioid receptor agonist DADLE On primary cultured rat's cortical neurons following hypoxia injury / 中华急诊医学杂志

Objective To study the protective effect of δ-opioid receptor agonist DADLE Oil hypoxia-in-duced injury of rat cortical neuronfl.Method Cortical neuron,q cultured for 8,lays were assessed by MAP2 im-munofluorescenee and randonly divided into hypoxia group(n=6),and DADLE preconditioning plus hypoxia group(n=6),normoxia group(n=6),and DADLE preconditioning plus normoxia group(n=6).The cells in hyoo O'oup Were cultured in a hyooxic incubator containing I%02,5%c02,and 94%N2 at 37℃.The cens in DADLE preconditioning groups Wel'preconditioned with 10 ttmol/L DADLE before culture.The cells in normoxia group were cultured in an incubator COntaining95%air and 5%c02 at 37℃.The survival rate ofneu.rOllS cultured for 72 hours was analyzed with hochest-33258 staining,and lactate dehydrogenase(LDH)release Wills detected.Glucose in the culture medium was detected to assess glucose/energy metabolism.The data of LDH re.1ease and ducose level were analyzed by A.NOVA.and cell survival rates wG:qanalyzed by Chi-square Tests.Re.vtats When cortical neurons were cultured for 8 davs,95%the cells were cortical neurous as assayed by MAP2 immunofluorescence·Cell survival rate was significantly higher in DADLE preconditioning Cus hypoxia group than in hypoxia group[(71.88±1.77)%vs.(43.58±3.07)%(P<0.05)].LDH release was significantly lower in DADLE preconditioning plus hypoxh group than in hypoxgroup[(3824.27±294.86)vs.(4516.59±605.02),P<0.05].Glucose level in the culture medium was significantly higher in DADLE preconditioning plus hypoxia group than in hypoxia group[(11.92-4-2.05)mmol/L vs.(9.88±0.71)mmol/L,P<0.051.Conclusions 6-opioid receptor agonist DADLE Can protect rat cortical neurons from hypoxia injury, which might be the mechanism of reducing glucose/energy metabolism in cortical neurons during the period of hypoxia.

Effects of Xuebijing injection on intestinal mucosal morphology in rats with sepsis / 中华急诊医学杂志

Objective To observe the effect of injecting Xuebijing via different routes, as either treatment or pretreatment, on changes in intestinal mucosal morphology in a rat model of sepsis. Method Ninety-one healthy Sprague-Dawley rats were randomly divided into five groups: 1) control group ( n = 7) , 2) sepsis group ( n = 21) , 3) intragastric pretreatment group ( n = 21) , 4) intravenous pretreatment group (n = 21) , and 5) intravenous treatment group (n = 21) . Except for the control group, the other groups were further divided into three sub-groups for assessment at 3, 6 and 12 h post-operation ( n = 7 per group) . Sepsis was induced by cecal ligation and puncture (CLP) . For the intragastric pretreatment group, Xuebijing injection (5 mL/kg) was administered via intragastric injection 2 hours before CLP. For the intravenous pretreatment group, Xuebijing injection (5 mL/kg)was administered via the caudal vein 2 hours before CLP. For the intravenous treatment group, Xuebijing injection (5 mL/kg) was intravenously infused 2 hours after CLP. The control group received no treatment. The ileum was removed from all rats for measurement. The rats were sacrificed at 3, 6 or 12 h after operation to obtain the ileum.Intestinal mucosal damage index and morphological changes in the intestinal mucosa were detected by light microscopy and electron microscopy. Analysis of variance was used to compare the groups. P -values < 0.05 were considered to indicate statistically significant differences. Results Intestinal mucosal damage was significantly reduced in and the three treatment groups compared with the untreated sepsis group (3h, F =53.35; 6h, F =74.93; 12 h, F - 171.27; P =0.000). Intestinal damage was significantly reduced in the intravenous pretreatment group compared with the intragastric pretreatment group (3 h, F = 53.35,P =0.036; 6 h, F = 74.93,P =0.039; 12 h, F = 171.27, P =0.042). Conclusions Irrespective of the route, the administration of Xuebijing protected against intestinal mucosal damage and intravenous pretreatment exerted the most effective protection against intestinal mucosal damage in this rat model of sepsis.

Protective role of heme oxygenase in myocardial dysfunction postresuscitation / 中华急诊医学杂志

Objective To study the cardioprotection effects of heme oxygenase-1(HO-1)on cardiopulmonary resuscitation(CPR).Method Male Sprague-Dawley rats were asphyxiated for 9 minutes and resuscitated.Rats wefe randomly divided into 4 groups,namely,sham asphysiation group,CPR group,Hemin group and Heroin +ZnPP group(zinc protoporyphyrin IX).Resuscitated groups were further divided into two subgroups according to various intervals:6 hours and 24 hours after resuscitation.Hemodynamic was observed.Serum creatine phosphokinase-MB(CPK-MB)and lactate dehydrogenase were determined.HO-1 in heart tissue homogenates was assayed.Ultrastructure of rats hearts was examined.Statical evaluation was performed with analysis of variance.Results The mean blood pressure(MBP)in resuscitated groups was significantly reduced after resuscitation,hadn't any difference between supgroups.The scores of dp/dt 40 and-dp/dt were significantly decreased in CPR group and Hemin+ZnPP group after resuscitation(all P＜0.05),but dP/dt40 in Heroin group did nol differ significantly after resuscitation.and-dp/dt decreased only 0.5 hours and one hour after resuscitation and returned to baseline values two hours after resuscitation.The scores of dp/dt 40and-dp/dt in Heroin group at different intervals after resuscitation were significantly higher than those in CPR group and Hemin+ZnPP group(all P＜0.05).Serum CPK-MB and LDH in CPR group and Hemin+ZnPP group at 6 hours and 24 hours after resuscitation were significantly higher than those in Hemin group(all P＜0.05).The cardiac tissue ultrastructure of rats in Hemin group was more intact than that of CPB group and Hemin+ZnPP goup.HO-1 levels in heart tissue homogenates of Hemin group at 6 hours and 24 hours after resuscitation were significantly higher than those in CPR group and Heroin+ZnPP group(all P＜0.05).Conclusions HO-1 expression induced by Heroin can effectively improve post-resuscitation myocardial dysfunction,alleviate cardiac injury,keep the ultrassructure integrity of cardiac myocytes.It may be a new approach to treat myocardial dysfunction after resuscitation.

Changes of matrix metalloproteinase-9 and blood brain barrier in cardiopulmonary resuscitation rats and effects of MMP-9 inhibitor on them / 中华急诊医学杂志

Objective To explore the changes of matrix metalloproteinase-9 and blood brain barrier in cardiopulmonary resuscitation rats and effects of MMP-9 inhibitor on them.Method One hundred and twenty Sprague-Dawley(SD) rats were randomly divided into 3 groups:the sham-operated group,the resuscitation with treatment group and the resuseimfion without treatment group as control.The experiment was made in the animal experiment center of Sun Yat-sen University in Gtlangzhou.The rat eardiopulmonary resuscitation model was made by clipping trachea until asphyxia,and the restoration of spontaneous circulation(ROSC)Was defined by restoration of superventricular rhythm and mean artery pressure (MAP)≥60 mmHg for more than 5 min utes.The rats of sham-operated group were anesahetized only and endotracheal intubation WaS performed.In the resuscitation with treaUnent group ss-3cr(25,ng/ks body weight)Was given intraperitoneally after ROSC.The rats were sacrificed and samples of the brain tissue were taken inmaediately and 3 h,9 h,24 h and 48 h later.After that,the expression of MMP-9 and MMP-9 mRNA in brain tissue were detected.Water oontent and Evans blue in brain tissue Were observed.The uhmmicrostructure of brain tissue was observed under electron microscope.Analysis ofvariance wilE, done with Spssll.0 software.Results 11le expressions of MMP.9 and MMP-9m RNA ofbraintissueiUthe shanloperated group didn't show significant changees in all specimens taken at different intervals and neither the water content and tvans blue did.The Pvalue were 1.0000,0.6831,0.7124 and 0.99r75,respectively.There was no u1.tramicrostruclure change in the sham-operated group.The expressions of MMP_9 and MMP-9 mRNA in the resuscitation control group obviously increased after eardiopulmonary resuscitation,80 did the water content and Evans blue content.Compared with sham-operated group,the P value were 0.0264,0.0163,0.0000 and 0.0412,respee.tively.111e elge of ultmmicrostmeture in the resuscitation control group at different intervals were obvious.The changes of obove biomarkers in the resuscitation treatment group Was siroilar to but less in magnitude than those in the resuscitation control group.The P valHe were 0.0392,0.0373,0.O004 and 0.0180,respectively.Conclusions The expressions of MMP-9 and MMP.9 mRNA obviously increases in the cerebral ischemia model of rats with CPR,and reaches peak at 24 h.Water content and Evans blue content in brain risque obviously increases in the cerebral ischemia model of rats with CPR.BBB iS destroyed.and the peak time iS at 24 h.The injury of ultrami.crostructure of brain tissue under electron microscope iS obvious,and the peak time is at 24 h.The SB-3CT.specif-iC inhibitor of MMP-9 could decrease the expression of MMP-9 and decrease cerebral edema in the cerebral is.chemia modeJ of rats with CPR,and the protection from cerebral isehemia/reperfusion injury after CPR is obvious.