Liao Xiao-xing

Model of cardiac arrest in rats by transcutaneous electrical epicardium stimulation

OBJECTIVE To establish a new model of cardiac arrest (CA) in rats by transcutaneous electrical epicardium stimulation. METHODS Two acupuncture needles connected to the anode and cathode of a stimulator were transcutaneously inserted into the epicardium as electrodes. The stimulating current was steered to the epicardium and the stimulation was maintained for 3 min to induce CA. Cardiopulmonary resuscitation (CPR) was performed at 6 min after a period of nonintervention. RESULTS CA was successfully induced in a total of 20 rats. The success rate of induction was 12/20 at the current intensity of 1 mA; and reached 20/20 when the current intensity was increased to 2 mA. After the electrical stimulation, the femoral blood pressure quickly dropped below 25 mmHg and the arterial pulse waveform disappeared. The average time from the electrical stimulation to CA induction was 5.10 (+/-2.81) s. When the electrical stimulation stopped, 18/20 rats had ventricular fibrillation and 2/20 rats had pulseless electrical activity. CPR was performed for averagely 207.4 (+/-148.8) s. The restoration of spontaneous circulation (ROSC) was 20/20. The death rate within 4h after ROSC was 5/20, and the 72-h survival rate was 10/20. There were only two cases of complications, a minor muscle contraction and a minor lung lobe injury. CONCLUSION The model of CA in rats induced by transcutaneous electrical epicardium stimulation is a stable model that requires low-intensity current and has fewer complications. This model may provide another option for experimental research of CA induced by malignant arrhythmia (especially VF).

Effects of therapeutic hypothermia on coagulopathy and microcirculation after cardiopulmonary resuscitation in rabbits

OBJECTIVE The aim of this study was to investigate the effects of therapeutic hypothermia (TH) on coagulopathy and cerebral microcirculation disorder after cardiopulmonary resuscitation (CPR) in rabbits. METHODS Cardiac ventricular fibrillation was induced by alternating current in 24 New Zealand rabbits, and hypothermia was induced by surface cooling or normothermia (NT) was maintained for 12 hours after the return of spontaneous circulation (ROSC). Several physiologic indexes were measured before CPR and at 4, 8, and 12 hours after ROSC. The microcirculation flow in the cerebral cortex was measured with a PERIMED Multichannel Laser Doppler system (Perimid, Sweden), and glomerular fibrin deposition was determined by microscopy. RESULTS Compared with the NT group, the prothrombin time, activated partial thromboplastin time, and international normalized ratio in the TH group were increased; there were no differences in anti-thrombin-III, protein C, and d-dimer indexes. The microcirculation flow in the cerebral cortex before CPR and after ROSC at 4, 8, and 12 hours was 401.60 ± 11.76, 258.86 ± 34.58, 317.59 ± 23.36, and 371.98 ± 5.79 mL/min, respectively, in the NT group, and 398.18 ± 12.91, 336.19 ± 19.27, 347.76 ± 13.80, and 383.78 ± 3.29 mL/min, respectively, in the TH group. There were apparent disparities at each checkpoint after ROSC in these 2 groups (4 hours: P = .001; 8 hours: P = .011; 12 hours: P = .009). The Pearson correlation test showed that the microcirculation flow in the cerebral cortex was positively correlated with activated partial thromboplastin time after ROSC (4 hours: r = 0.503, P = .033; 8 hours: r = 0.565, P = .035; 12 hours: r = 0.774, P = .009), but not with other coagulation parameters. CONCLUSIONS Therapeutic hypothermia might cause coagulant dysfunction but concomitantly improves the microcirculation flow in the cerebral cortex, which might be an effect of TH that results in cerebral protection.

Changes in CD4+CD25+ Tregs in the pathogenesis of atherosclerosis in ApoE−/− mice

The goal of this study was to observe the pathological characteristics of atherosclerotic plaques in the aortic walls of ApoE−/− and C57BL/6J mice and the changes of CD4+CD25+ regulatory T cells (Tregs) in atherosclerotic mice. Twenty ApoE−/− mice were split into high-fat diet (AH) and normal diet (AN) groups and 10 C57BL/6J male mice were designated as the control group (BN). The serum concentrations of IL-10 and TGF-β1 were detected by enzyme-linked immunosorbent assay; paraffin sections of the aorta were stained with hematoxylin & eosin, and morphometric parameters were measured using the Image Pro Plus 6.0 system. Verhoeff stain was used to observe the distribution of elastic fibers, and immunohistochemical staining was performed to verify the phenotype of the forkhead box protein 3 (Foxp3+) CD25+ cells in the atherosclerotic tissue. The proportion of CD4+CD25+ Tregs in the spleen was calculated by flow cytometry. The thickness of the intima, the intima/media ratio, the plaque area, and the plaque/lumen ratio of mice in AN group were significantly larger than those of mice in BN group. The thickness of the intima, the plaque area, and the plaque/lumen ratio of the mice in AH group were significantly increased compared with those of the AN group mice. The serum concentrations of IL-10 and TGF-β1 and the percentage of splenic CD4+CD25+ Tregs in AN group mice were significantly decreased compared with the control group. The serum concentrations of IL-10 and TGF-β1 and the percentage of splenic CD4+CD25+ Tregs in the mice in AH group were significantly decreased compared with those in AN group. The proportions of Foxp3+ and CD25+ cells within the total lymphocyte population were significantly decreased in AH group mice compared with those in AN group mice. Atherosclerosis in an experimental mouse model was correlated with Treg depletion in the lymphoid tissues and plaques, indicating the important antiatherosclerotic role of CD4+CD25+ Tregs. Impact statement In this article, we conclude that Tregs decreased with atherosclerosis (AS) as determined in ApoE knockout mice fed a high fat diet. It is an important matter for understanding the AS pathology.

GW24-e3511 Efficacy and prognosis of low molecular weight heparin (LMWH) in the treatment for the patients with chronic cor pulmonale during acute attack

Objectives To investigate the efficacy and prognosis of low molecular weight heparin (LMWH) in the treatment for the patients with chronic cor pulmonale during acute attack. Methods 320 cases patients with chronic cor pulmonale during acute attack, were at random divided into study group (167 cases) and control group (153 cases) all the patients in two groups were given the same routine treatments such as anti-infection, expectorant, relieving spasm, balancing hydro-electrolytic disorder, low flow oxygen inhalation, and conventional digitals, diuretics, vasodilators therapy. In study group, besides routine treatment, low molecular weight heparin (LMWH) was given. compared clinical features, laboratory results in the two groups before and after the treatment. We followed up these cases during 90 days after treatment, the patients in both groups were observed for comparison of the clinical effect, major adverse events rate, complication, stroke and the death of 90 days. Results Clinical features, laboratory results in study group were markedly improved after the treatment than those in control group (91% VS 82%) (P < 0.05), the patient in control group was associated with an increase numbers of hospitalisation and shorter time interval for readmission for the patients with chronic cor pulmonale during acute attack (P < 0.05). Morbidity from brain stroke is more frequent in control group than those in study group, 11/167 VS 3/153 (P < 0.05). Conclusions Low molecular weight heparin (LMWH) was effective to the patients with chronic cor pulmonale during acute attack.

GW24-e0338 The effects of activation of autophagy on the neuron injury after return of spontaneous circulation from ventricular fibrillation in Wistar rats

Objectives To investigate the effects of activation of Autophagy on cerebral injury after cardiopulmonary resuscitation (CPR) in Wistar rat. Methods First 36 healthy adult male Wistar rats were induced ventricular fibrillation (VF) by alternating current for 7 minutes and then received CPR. Before VF (0) and at 1, 2, 4, 8 and 12 hours after return of spontaneous circulation (ROSC), cerebral cortex were harvested to determine the expressions of beclin-1 and LC3II by Weston blot. Further 60 healthy adult male Wistar rats were used to observe the effects of Autophagy activator Rapamycine (Rapamycine group, 20), Autophagy inhibitor 3-Methyladenine (3-MA group, 20) and Normal saline (Control group, 20) on the expressions of beclin-1, LC3II and the formation of autophagic vacuole in the cerebral cortex after ROSC. The neurologic deficit score (NDS) was used to evaluate the neurologic function at 24, 48 and 72h respectively after ROSC. The numbers of viable neurons and apoptotic neurons in the parietal cortex were counted by H&E staining and TUNEL staining after 72h. One-way ANOVA was used for the expressions of beclin-1 and LC3II and neurons counting. Rank sum test was used for NDS. Results The expressions of beclin-1 and LC3 II were significantly lower at 2 and 4h after ROSC than the levels before VF (P < 0.05). The expressions of beclin-1 and the conversion of LC3 II in cerebral cortex at 2 and 4h after ROSC in the Rapamycine group were significantly higher than that in Control group and 3-MA group (P < 0.05). The numbers of autophagic vacuole in the Rapamycine group at 2 and 4h after ROSC were significantly higher than the Control and 3-MA group. The number of viable neurons at 72h after ROSC in the Rapamycine group was 19 ± 516 ± 4/400pixs, higher than 16 ± 4/400pixs in Control group and 15 ± 3/400pixs in 3-MA group (P < 0.05). The number of the TUNEL positive cells in the Rapamycine group was 12 ± 4/400pixs and was lower than 15 ± 6/400pixs in the Control group and 17 ± 5/400pixs in 3-MA group (P < 0.05). The NDS scores of animals in Control group and 3-MA group at 24, 48 and 72h after ROSC were inferior to Rapamycine group. Conclusions The Autophagy of neurons in the cerebral cortex was attenuated in Wistar rats after ROSC. The activation of Autophagy can decrease the number of apoptotic neurons, preserve viable neurons and improve neurologic function.

EFFECTS OF THE APPLICATION OF ULINASTAIN ON THE ACTIVATION OF NF-κB AFTER CARDIAC ARREST

Objectives The aim of this study was to investigate the incidence of systemic inflammatory response syndrome (SIRS) after cardiopulmonary resuscitation (CPR) and to assess the affection of Ulinastain on SIRS after CPR. Methods Forty patients experienced CPR and survival more than 48 h after ROSC were randomized into Ulinastain group and control group. The level of blood nuclear factor-kappa B (NF-κB), IL-6, TNF-α of the patients was measured. All patients were evaluated by SIRS diagnosis standard and their general organ functions were examined. Results Activation of NF-κB, IL-6 and TNF-α of patients experienced CPR were significantly higher than normal people (p<0.05). The Ulinastain group had significantly lower blood level of NF-κB, IL-6, TNF-α than control group (p<0.05). Only 20% patients receiving Ulinastain suffered SIRS after CPR, compared to 65% patients in the control group (p<0.05). Ulinastain infusion caused a significant decrease in mean blood level of CK, AST, ALT and Cr than the control group (p<0.05) . Conclusions Ulinastain applied after CPR plays a role in inhibition of inflammatory mediators and may be one reason for the lower incidence of SIRS.

COMPARISON OF TIMI, PURSUIT AND GRACE RISK SCORES IN PATIENTS PRESENTING EMERGENCY DEPARTMENT WITH NON-ST-ELEVATION ACUTE CORONARY SYNDROME

Objectives Risk stratification for patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) is a difficult challenge for physicians. This study was to compare, the prognostic value of three clinical risk scores, the GRACE, PURSUIT and TIMI score in NSTE-ACS patients. Methods Pub Med was systematically searched for the TIMI, PURSUIT and GRACE risk score studies, especially the UA/NSTEMI studies. 8 eligible studies with 25 247 people were formally appraised. The GRACE scores, PURSUIT scores and TIMI score were subsequently divided into low, intermediate and high equivalent strata to facilitate comparison. The study endpoint was cardiac event in hospital, at short term (30-days) and over longer term (360-day) follow-up. χ2 test and Wilcoxon (Gehan) Statistic were used for statistical analysis where appropriate. Results In-hospital cardiac event rates in all risk scores were of no statistically significant difference. At 30-day follow-up, in low risk group, TIMI performs better than the other two risk scores (TIMI vs PURSUIT, p<0.001; TIMI vs GRACE, p < 0.001; TIMI > PURSUIT, GRACE in event rate); in intermediate group, TIMI performs than the others again (TIMI vs PURSUIT, p<0.001; TIMI vs GRACE p < 0.001; TIMI > PURSUIT, GRACE in event rate); but in the high risk group, PURSUIT performs best (TIMI vs PURSUIT, p=0.023; PURSUIT vs GRACE, p=0.005; PURSUIT>TIMI, GRACE in event rate). At 1-year follow-up, there is no statistical significance among each low risk group; TIMI and PURSUIT performs better in the intermediate group (PURSUIT vs GRACE, p=0.0091; TIMI vs GRACE, p=0.009; PURSUIT, TIMI>GRACE in event rate), but in the high risk group, PURSUIT and GRACE performs better (TIMI vs PURSUIT, p=0.012; TIMI vs GRACE, p < 0.001; GRACE > PURSUIT>TIMI). Conclusions In NSTE-ACS population, TIMI risk score can be widely applied. At 30-day PURSUIT are better than others in the high-risk group. GRACE is superior at long term follow-up in high risk group.

e0186 Study on the mechanism of inhibitory effect of CTLA-4Ig fusion protein on atherosclerosis in apoe deficient mice

Objective To investigate the mechanism of inhibitory effect of CTLA-4Ig fusion protein on atherosclerosis in mice with an apolipoprotein-E gene defect fed on cholesterol diet. Methods 30 male 10-week-old apoE(-/-) mice were fed on cholesterol diet and divided into CTLA-4Ig treatment group, IgG1 group and PBS group at random, 10 in each. The three groups were given intraperitoneal injection of CTLA-4Ig (10 μg per time), Rat-IgG1 (10 μg per time), (and) PBS (100 μl per time) respectively, twice a week, for 12 weeks. Followed by a 12-week treatment, the whole aorta from the root to crotch of iliac artery was separated after anaesthesia with the intraperitoneal injection of 1% pentobarbital and the whole (total) blood was taken to obtain serum. Subsequently, the area ratio of plaque and lumen, the thickness ratio of endangium and tunica media, the lipid-soaking extent intra-plaque and the content of collagen fibrils and smooth muscle cells intra-plaque were analysed by image-processing soft. The serum concentration of total cholesterol, CRP, sICAM-1, IFN-γ, IL-10, and TGF-β1 were measured. Results There were typical atherosclerotic plaque in apoE(-/-) mice fed on cholesterol diet after 12 weeks and it was light in the CTLA-4Ig group. There were statistical value of difference in the area ratio of plaque and lumen, the thickness ratio of endangium and tunica media, the lipid-soaking extent intra-plaque, and the content of collagen fibrils in three groups (p all<0.05). It was found that the area ratio of plaque and lumen, the thickness ratio of endangium and tunica media, and the lipid-soaking extent intra-plaque were significant lower and the content of collagen fibrils was higher in the CTLA-4Ig group than those in the IgG1 group and PBS group (p all<0.05), but there was no significant difference in those between the IgG1 group and PBS group (p all>0.05). There were no significant difference in content of smooth muscle cells in three groups (p>0.05). There were no significant difference in serum concentration of total cholesterol in three groups (p>0.05). There were statistical value of difference in the serum concentration of CRP, sICAM-1, IFN-γ, IL-10, and TGF-β1 in all three groups (p all<0.05). It was found that CTLA-4Ig could decrease the serum concentration of CRP, sICAM-1 and IFN-γ and increase IL-10 and TGF-β1, but IgG1 and PBS. Conclusions CTLA-4Ig fusion protein could inhibit the (del) atherosclerosis progression in apoE(-/-) mice fed on cholesterol diet and its effect might be associated with blocking B7/CD28, anti-inflammation, promoting Th2 polarisation and affecting regulate T cells.

e0004 Hydrogen sulfide inhabits neurons apoptosis in rats after cardiopulmonary resuscitation

Objective To investigate the effects of hydrogen sulfide (H2S) on brain injury after cardiopulmonary resuscitation (CPR) in rats by examining neurons apoptosis. Methods The 40 male SD rats were randomly divided into experimental and control groups equally. In control group, CPR was performed with Utstein mode at 6 min after CA. On this basis, sodium hydrosulfide was administrated to the rats after restoration of spontaneous circulation in experimental group. On seventh day after CPR, neurons apoptosis was examined using terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling (TUNEL) staining and the expression of caspase-3 was detected by the immunohistochemical strepto avidin biotinperoxidase complex (SABC) method in cortex, hippocampus CA1 region and cerebellum of the rats. Results 1. There were 12 and 10 rats completed the experiment in the experimental and control group respectively. Their fate between the two groups was no significant difference (χ2=0.404, p=0.376). 2. On seventh day after CPR, The serum concentrations of H2S was 9.12±3.17 μmol/l in the experimental group and the contrast was 3.72±1.05 μmol/l, the difference between the two groups had statistic significance (t=5.136, p=0.000). 3. Compared with the control group, the experimental groups neurons apoptosis index and the sum of integrated optical density (IOD) of caspase-3 in cortex, hippocampus CA1 region and cerebellum were obviously reduced (p<0.05). Conclusion After CPR, H2S can inhabit neurons apoptosis and its mechanism may be through caspase-3 pathway. It may play a role in the treatment of the brain injury after CA.

e0006 Effects of neotype peritoneal cooling on the injured of intestinal mucous after cardiopulmonary resuscitation in rabbits

Objective To explore whether the peritoneal cooling after cardiopulmonary resuscitation could improve the injured of intestinal mucous in rabbits. Methods 36 adult New Zealand rabbits were induced ventricular fibrillation by AC current. After the restore of spontaneous circulation (ROSC), rabbits were randomly divided into three groups according to the way of body temperature controlling, that is, nomothermia group (NT), surface cooling group (SC) and peritoneal cooling group (PC). The changing of tympanic temperature and peritoneal temperature were observed after ROSC. The animals were sacrificed by over anaesthesia after ROSC for 12 h, the end ileum was removed and fixed in formalin, the histological injured and the expression of TNF-a and VCAM-1 in ileum were observed by H.E staining and immune chemical methods. Results 12 animals in each group, 9 in group NT, 10 in group SC and 9 in group PC were successfully resuscitated; all animals were on mechanical ventilation for 2 to 4 h. 5, 6 and 8 animals in each group respectively survived to the end of the experiment. The temperatures of tympanic and peritoneal cavity of animals in group NT were maintained in normal range. The tympanic temperature of animals in group SC and PC was arrived target temperatures at 29±6.55 min and 62±8.27 min. During the stage of maintenance of hypothermia, the tympanic and peritoneal temperatures of animals in group SC were in range 33 to 35°C, while the peritoneal temperatures of animals in group PC were in range 31 to 34°C, 1 to 2°C lower than the tympanic temperature. The scores of histological injured of ileum were 1.43±0.53 in group PC, 3.4±0.55 in group NT and 3.17±0.41 in group SC. The differences among them were significantly, PC versus SC, p<0.000; PC versus NT, p<0.000; while SC versus NT, p=0.30. The expression of TNF-a in ileum was 9.98±1.79% in group NT, 5.87±1.43% in group SC and 3.78±0.53% in group PC, the differences among them were significantly. The phenomenon of the expression of VCAM-1 was little like the TNF-a, 3.78±0.53% in group PC was significantly from the 8.53±1.53% in group NT and 5.92±1.06% in group SC. Conclusion The neotype peritoneal cooling can improve the injured of ileum mucous beside quickly induce hypothermia after ROSC in rabbits.