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Objective:To investigate changes in arterial acid-base and electrolytes after repeated episodes of ventricular fibrillation (VF) and defibrillation in a swine model.Methods:Sixteen Peking white swine, weighting (32±2.5) kg, were placed with temporary pacemaker electrodes via the left femoral vein into the right ventricle after anesthesia. Then VF was electrically induced by using a programmed electrical stimulation instrument. An arterial cannula was inserted into the left femoral artery to measure mean arterial blood pressure and cardiac output using a PiCCO monitor, with blood samples collected. The pigs were randomly divided into two group: the manual defibrillation group (MD, n=8) and the automated external defibrillation group (AED, n=8). The first defibrillation was attempted with the manufacturer’s dose (150 J) for 15 s after the successful induction of VF in the MD group. If spontaneous circulation was not recovered, 2-min chest compression and subsequent defibrillation (200 J) were attempted. For the AED group, the defibrillation was delivered following voice prompts of the AED. After the return of spontaneous circulation, the pig was allowed to stabilize for 30 min, followed by the induction of the next episode of VF. The above process was repeated five times. Arterial blood gas, cardiac biomarkers, and hemodynamic variables were measured at 30 min after the return of spontaneous circulation. Results:All pigs were successfully induced VF five times and defibrillated successfully. There were no significant changes in heart rate and mean arterial blood pressure between the two groups after repeated episodes of VF and defibrillation. Compared with baseline measurements, cardiac output tended to decrease after repeated episodes of VF and defibrillation but was not statistically significant (all P>0.05). There were no significant differences in arterial pH, HCO 3-, sodium, and lactic acid in the two groups between each measurement time point and baseline values after repeated VF (all P>0.05), but potassium levels in the two groups decreased with time, and the difference was statistically significant compared with the baseline measurement (all P<0.05). There were no significant differences in myoglobin, creatine kinase isoenzyme-MB, and cardiac troponin I for the two groups compared with baseline values after repeated episodes of VF and defibrillation or various episodes of VF between the two groups (all P > 0.05). Conclusions:Repeated episodes of VF and defibrillation have no significant effect on pH balance, but significantly decrease blood potassium. Clinical approaches (MD vs. AED) do not affect defibrillation effect, with no significant differences in hemodynamic variables and myocardial injuries.
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Cystic echinococcosis (CE) caused by E. granulosus is a serious helminthic zoonosis in humans, livestock and wildlife. Xinjiang is one of high endemic province for CE in China. A total of 55 sheep and cattle livers containing echinococcal cysts were collected from slaughterhouses in Changji and Yining City, northern region of Xinjiang. PCR was employed for cloning 2 gene fragments, 12S rRNA and CO1 for analysis of phylogenetic diversity of E. granulosus. The results showed that all the samples collected were identified as G1 genotype of E. granulosus. Interestingly, YL5 and CJ75 strains were the older branches compared to those strains from France, Argentina, Australia. CO1 gene fragment showed 20 new genotype haploids and 5 new genotype haplogroups (H1-H5) by the analysis of Network 5.0 software, and the YLY17 strain was identified as the most ancestral haplotype. The major haplotypes, such as CJ75 and YL5 strains, showed identical to the isolates from Middle East. The international and domestic trade of livestock might contribute to the dispersal of different haplotypes for E. granulosus evolution.
Subject(s)
Animals , Cattle , Humans , Abattoirs , Argentina , Australia , China , Clone Cells , Cloning, Organism , Echinococcosis , Echinococcus granulosus , Echinococcus , France , Genetic Variation , Genotype , Haploidy , Haplotypes , Helminths , Liver , Livestock , Middle East , Polymerase Chain Reaction , SheepABSTRACT
Objective To reveal the changes of catecholamine and lactate levels in myocardial interstitial fluid during cardiopulmonary resuscitation in order to prove the protective effects of sildenafil pretreatment on post-resuscitation myocardial function in swine model of ventricular fibrillation (VF).Methods Twenty-four swine were randomly (random number) divided into three groups:saline group,sildenafil group and shame operation group.Sildenafil in dose of 0.5 mg/kg dissolved in 40 mL of saline was given to swine once intraperitoneally 40 min prior to VF in sildenafil group.The equivalent volume of saline (0.9％ NaC1) alone was administered instead in saline groups.There was no treatment in shame operation group.After ventricular fibrillation untreated for 8 min,open-chest cardiopulmonary resuscitation was initiated.The hemodynamic variables were recorded at baseline,4 min,1 h and 6 h after restoration of spontaneous circulation (ROSC).The interstitial fluid from the left ventricle wall was collected by using the microdialysis tubes at given intervals,in which the levels of dopamine,norepinephrine,epinephrine,and lactate were measured.The samples for pathological examination were taken at 24 hours after ROSC.Results The levels of catecholamine and lactate in the sildenafil group were lower than those in saline group at all different intervals (P ＜ 0.05 or P ＜ 0.01).The cumulative defibrillation energy was lower in the sildenafil group than that in the saline group (P ＜ 0.05).The hemodynamic changes and myocardial histological damage in sildenafil group were milder than those in saline group (P ＜ 0.05).The pathologic changes of myocardium and mitochondria in saline group were more severe than those in sildenafil group.Conclusions Sildenafil pretreatment prior to VF can effectively reduce endogenous catecholamine secretion and lactate levels in myocardial tissue,protecting the myocardium and improving post-resuscitation myocardial function.
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Objective Two different transthoracic impedances were made with an adjustable impedance instrument to compare the success rate of defibrillation,heart and skin damage in a porcine model.Methods A total of sixteen pigs were randomly (random number) divided into two groups:low impedance group (about 50 Ω,n =8) and high impedance group (about 100 Ω,n =8).Defibrillation (recommended 150 J) was first attempted at 15 s after induction of ventricular fibrillation (VF).If spontaneous circulation was not recovered,2-minute chest compression and subsequent defibrillation attempts (maximum 200 J) were attempted.Model animal kept stabilization for 30 min after return of spontaneous circulation before induction of the next episode of VF,which was induced five episodes in each pig.Results In the low impedance group,VF was induced 39 times,39 of 43 attempted defibrillations were successful.In the high impedance group,VF was induced 40 times,40 of 70 attempted defibrillations were successful.The current and success rate of the first defibrillation were (34.9 ±3.2) A and 94.9％ respectively in the low impedance group,while those of the high impedance group were (19.1 ±2.1) A and 50％ respectively (both P ＜ 0.05).There were no significant differences in skin damage between two groups,but myocardial injury was lighter in the high impedance group.Conclusions Success rate of the first defibrillation with recommend 150 J obviously decreases with the increase of transthoracic impedance.The main factor of myocardial injury is current instead of the numbers of defibrillation.
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Objective To evaluate the infection rate and influencing factors of Hepatitis E Virus among different occupational population in nanjiang region of Xinjiang. Methods A cross-sectional survey was carried out in occupational population and non-occupational population having a close contact with livertock. Serum IgG antibodies against hepatitis E virus was tested by indirect enzyme-linked immunosorbent assay , and logistic regression model was used to analyze the risk factors of HEV infection. Results The result showed that the total positive rate was 51.88% and 317 out of 611 subjects were anti-HEV IgG positive. Non-occupational population had the lowest positive rate (35.90%), followed by the stock man of intensive nursery (24.14%), stock man of scattered nursery (76.00%), livestock and meat salesperson (79.37%) and slaughterman (81.53%). Multivariate logistic regression analysis showed that close contact with livestock , eating out and without frequent hand washing increased the risk of HEV infection . And HEV infection rate decreased in the population with professional training. Conclusion It is noticeable that promoting good health habits and cutting off animal-contact transmission are effective measures for the prevention of hepatitis E.
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Objective:To investigate the infection status and influencing factors of hepatitis E virus infection among different occupational populations in Xinjiang region,and to provide a available evidence for control of hepatitis E.Methods:A randomly sampling survey was carried out in the population of public health practitioners, the serum IgG antibodies against hepatitis E virus in 1 720 samples were tested by indirect enzyme-linked immunosorbent assay,and the experimental data was analyzed with SPSS 19.0 software;the differences of infection rates between genders,ages and occupations were analyzed.Results:Among 1 720 subjects,440 persons were anti-HEV IgG positive,and the total positive rate was 25.58%;the positive rate of males (27.99%)was higher than that of females (23.35%),and the IgG positive rate was increased along with the age;there were significant differences of the anti-HEV-IgG antibody positive rates between the populations with different ages (χ2 =118.262, P = 0.000 ). There was a statistically significant difference of infection rate of hepatitis E between different occupational populations (χ2 = 98.262,P = 0.000),the slaughterman had the highest positive rate (81.53%), followed by the livestock and meat salesperson (79.37%),food service population (30%),supermarket population (11.21%)and others (9.03%).Conclusion:The hepatitis E infection rate is high among the public health practitioners in Xinjiang region,and occupation,age and gender are the major influencing factors of hepatitis E infection rate.
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Objective To evaluate the effects of ulinastatin (UTI) on brain protection after cardiopulmonary resuscitation in a porcine model.Methods A total of 20 female swine were induced to make ventricular fibrillation (VF) by programmed stimulation method,and CPR was stared after 8 mins after VF.Swine after ROSC (return of spontaneous circulation) were randomly (random number) divided into two groups,namely UTI group and control group.In UTI group,UTI was administered slowly in a dose of 100 000 U dissolved in 5 ml saline immediately after resuscitation and then given every 3 h until 24 h after CPR (UTI not given at the time of 24 h) ; and 5 ml saline was used instead in control group.Venous blood samples were taken separately before VF,immediate after resuscitation and 3 h,12 h and 24 h after ROSC for detecting levels of TNF-o and IL-1β.Cerebral performance category (CPC) scores were assessed 24 h after ROSC,and subsequently the swine were sacrificed to get brain specimens for histopathological and ultrastructural examination under ordinary light microscope.Results Fifteen of twenty domestic swine were successfully rescued 8 mins after ventricular fibrillation.Swine of UTI group (n =8) and control group (n =7) were all survived over 24 h.Both TNF-α and IL-1β levels were significantly lower in UTI group than those in control group at intervals of 3 h,12 h and 24 h after ROSC (P ＜0.05).Twenty-four hours after ROSC,CPC scores of swine were higher in UTI group than those in control group (P ＜ 0.05).The brain injury 24 h after ROSC was significantly attenuated in UTI group than that in control group.Conclusions UTI can reduce the injury of brain tissue and improve the recovery of cerebral function after CPR.
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ObjectiveTo study the role of catecholamine in genesis of myocardium injury after organophosphorus poisoning (OP) in order to elucidate the underlying mechanisms of OP-induced cardiotoxicity.Methods Of 92 patients with severe acute dichlorvos poisoning,41 were consecutively enrolled for study and followed up for three months. The levels of serum creatine kinase isoenzyme myocardium (CK-MB),cardiac troponin Ⅰ (cTnI),acetylcholinesterase (AChE),acetylcholine (Ach),epinephrine and norepinephrine were assayed on the 1st,3rd and 5th days after admission and on the day of discharge.Electrocardiography was recorded every day after admission.ResultsOf them,37 (90.2％ )patients survived and four ( 9.8％ ) patients died during treatment.Sinus tachycardia was found in 37 (90.2％ ) patients and ST-T changes in 33 (80.4％ ) patients.CK-MB and cTnI levels peaked 3 days after admission,and then decreased to normal levels.Serum Ach,epinephrine and norepinephrine peaked on the 1st day after admission and then decreased.ConclusionsSevere acute dichlorvos poisoning is associated with myocardial dysfunction likely caused by increase in catecholamine levels.
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Objective In order to extrapolate the respiratory dysfunction of patients in early stage of acute organophosphorus pesticide poisoning (AOPP),transpulmonary thermodilution technique was used in swine models of severe acute dichlorvos poisoning (SADP) to evaluate respiratory function.Methods Twenty healthy female swine were randomly divided into dichlorvos ( n =7 ),atropine ( n =7 ) and control (n =6) groups.In the dichlorvos group,the swine were administered with 80％ emulsified dichlorvos (100mg/kg) via the gastric tube toinduce SADP.In the atropine group,swinewere administered with dichlorvos,and 0.5h later,atropine was injected to obtain and maintain atropinization.The swine of control group were administered with saline solution instead.Arterial and venous blood samples were collected 0,0.5,1,2,4 and 6 hours after modeling for blood gas analysis and detecting acetylcholinesterase levels.Both extravascular lung water index (EVLWI) and pulmonary vascular permeability index ( PVPI ) were measured by using PiCCO (pulse indicator continuous cardiac output ). At the termination of the experiment,the animals were sacrificed and the lung wet/dry weight ratio was determined and histopathological changes of lung tissue were also observed under microscope.Results In the dichlorvos group,EVLWI and PVPI were substantially increased from 0.5 h to 6 h after modeling but PaO2/FiO2 decreased from 0-6 h after modeling.In the atropine group,EVLWI and PVPI increased initially,but then they decreased 1 h afterwards and PaO2/FiO2 was also gradually decreased from 0-1 h.In both dichlorvos group and atropine group,the EVLWI was negatively correlated with PO2/FiO2 and positively correlated with PVPI.Compared with the control group,the lung wet/dry weight ratio increased markedly in the dichlorvos group and mildly increased in the atropine group.Meanwhile,the histopathological changes of lung tissue were obvious in the dichlorvos group and mild in the atropine group.Conclusions SADP swine experienced substantial changes in respiratory function. EVLWI was a reliable and valuable indicator for evaluating respiratory function in the early stage of AOPP.
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Objective Gasp was defined as a pathology respiration during cardiac arrest. This study was to investigate its effect on hemodynamics during CPR. Method Twelve domestic pigs, weighening (30 ± 1) kg,were anaesthetized. After tracheal intubation and mechanical ventilation, continuous respiratory variables were recorded. An artery catheter was inserted for reference blood samples and measuring aortic artery pressure (AOP).Right atrial pressure (RAP) and cardiac output (CO) were detected by Swan-Ganz catheter. Ventricular fibrillation (VF) was induced by programmed electrical stimulation instruments. After 4 minutes untreated VF, standard 30:2 CPR was done for 12 minutes and the parameters were recorded. Results pH, PaCO2 and lactic acid increased and PaO2 decreased progressively during CPR, whereas PaO2 was up to 50mmHg during the whole protocol. Gasps were observed in 10 animals, but weaken gradually; the left 2 animals with no gasp did not restore of spontaneous circulation (ROSC). Standard CPR could produce passive ventilation more than dead space (VD), but its tidal volume decreased gradually, which led to the percentage of rescue ventilation increased progressively. Positive correlations were found between CO, coronary perfusion pressure (CPP) and minute ventilation of gasps (MVg) (r was 0.736 and 0.721 respectively, both P ＜0.01); negative correlation were found between RAP and MVg (r= -0. 744, P ＜ 0.01). Conclusions Standard CPR could maintain 12 minutes oxygenation of body; compressions could produce enough passive ventilation more than VD; gasps were benefit to ROSC by increasing CO, CPP and decreasing RAP.
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Objective Amiodarone was diluted to release the side effect of hypotension in clinic, but this maybe unsuitable during cardiopulmonary resuscitation (CPR). This study was designed to observe the effects of undiluted amiodarone, diluted amiodarone, and CPR alone on ventricular fibrillation (VF) in a pig model. MethodsVF was induced in 21 pigs. The animals were randomly (random mumber) divided into 3 groups after VF 3 min.① CPR group ( n= 7): standard CPR; ② undiluted amiodarone group ( n= 7): undiluted amiodarone (5 mg/kg)bolus within 3 s, then 20 mL saline flush into the peripheral vein, CPR was started after observed 30 s; ③ diluted amiodarone group ( n = 7): amiodarone was dissolved in 20 mL saline and bolus with 30 s. Defibrillation was attempted at VF 5 min. Results The restoration of spontaneous circulation (ROSC) of CPR and undiluted amiodarone groups were higher than diluted group (85.7％ vs. 71.4％ vs. 42.9％), but the differences were not significant (all P ＞0.05). The defibrillation energy and timesof CPR group were higher than that of undiluted amiodarone (P= 0.009) and diluted group ( P = 0. 170). The mean arterial pressure of undiluted amiodarone were lower than diluted and CPR groups at ROSC 10 min (all P ＜0.05), but the differences of undiluted and diluted groups were not significant after ROSC 0.5 h. Conclusions In this study, undiluted amiodaronecan effectively reduced the defibrillation times and energy. Although diluted amiodaronecan release the side effect of hypotension which was transient, it didn't significantly improved cardiac electric activity and delayed to start CPR.
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Objective To establish a stabile normal model of cardiac arrest (CA) by programmed electrical stimulation(PES). Method Eighteen healthy domestic swine were anesthesiased with propofol. Ventrieular fibril-lation (VF) was induced by PES through right ventricle after tracheal intubation. The PES mode is S1S2 (300/200 ms), 40 V, and-10 ms step length. Results VF was successfully induced in 16 of eighteen swine with the method of PES. The extent of coupling interval of S1S2 was between 110 and 190 ms (168±23) ms. VF occurred in 2 swines when S1S1 (350 ms) stimulus was used to decide if the electrede was placed in right ventricle. All the swine were successfully defibrillated after 3 minutes of untreated VF. Conclusions This swine model of VF is easy to repeat and orerase, and has little injury on the heart. Therefore PES is a good method to make animal car-diac arrest model.