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Objective:To determine the adverse effects of continuous circulatory support on liver and kidney function in experimental animals using left ventricular assist devices (LVAD).Methods:Six healthy experimental sheep were selected and implanted with HeartCon type LVAD. The liver and kidney indexes of experimental sheep before and 70 days after operation were detected, including urea (UREA), creatinine (CREA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL), and the functional changes of liver and kidney were evaluated.Results:The preoperative levels of UREA, CREA, ALT, AST and TBIL in the six experimental sheep were (4.60±1.51) mmol/L, (94.80±23.10) μmol/L, (16.20±6.87) U/L, (82.60±17.33) U/L, and (0.52±0.25) μmol/L, respectively. Compared with the indexes before the LVAD implantation, there was no significant change in CREA levels in experimental sheep after the implantation (all P>0.05). After the implantation, the levels of UREA, ALT, AST and TBIL increased to varying degrees within 1 to 14 days after the implantation. At the end of the study, the levels of UREA, ALT, AST and TBIL have returned to the preoperative levels, and the differences were not statistically significant (all P>0.05). Conclusions:Within the 70 days of continuous circulatory support with HeartCon-type LVAD, no evidence of adverse effects of continuous flow LVAD on the liver and kidney function of experimental animals was found. HeartCon-type LVADs are able to provide adequate circulatory support to maintain proper end-organ function.
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Objective To explore the biodistribution and quantitative value of 18F-Flurpiridaz in mini-swine,and compare with 13N-NH3 · H2O.Methods Ten Bama mini-swine were divided into normal group and myocardial infarction group (n=5 in each group).Normal group was not treated and myocardial infarction group was modeled by thoracotomy and coronary artery ligation.Both groups were preceded by 13N-NH3 · H2O imaging,followed by 18F-Flurpiridaz imaging (time interval ＞40 min).Injection dosage of 2 tracers was the same (185-370 MBq).18F-Flurpiridaz whole-body PET/CT imaging was also performed in normal group.Biological distribution of 18F-Flurpiridaz was observed,and the ratio of radioactive uptake of 18F-Flurpiridaz between myocardium and adjacent tissues or organs was calculated.Image quality score and rest myocardial blood flow (rMBF) of 2 imaging tracers in normal group were measured and compared.MPI image quality score,cardiac function parameters such as summed rest score (SRS),myocardial infarction area percentage,total perfusion defect (TPD),and left ventricular ejection fraction (LVEF) of 2 imaging tracers were compared in myocardial infarction group.Data was analyzed by paired t test.Results In normal group,18F-Flurpiridaz in the myocardium was clearly observed,with high radioactive uptake maintaining within 2 h postinjection.The radioactivity count ratios of left ventricular myocardium to cardiac pool,the lungs and liver were high (5.19-12.87,4.17-50.51,2.08-6.92).The quality of 18F-Flurpiridaz MPI images in both groups was excellent (10/10).The rMBF (ml · g-1 · min-1) in different regions of left ventricle measured by 18F-Flurpiridaz and 13N-NH3 · H2O imaging were not significantly different (left anterior descending:0.98±0.06 vs 0.92±0.13;left circumflex:0.98±0.05 vs 0.88±0.12;right coronary artery:0.95±0.07 vs 0.88±0.15;left ventricle:0.96±0.07 vs 0.90±0.13;t values:from-1.70 to-0.90,all P＞0.05).There was no significant difference in SRS,myocardial infarction area percentage,TPD,rMBF or LVEF between 18F-Flurpiridaz and 13N-NH3 · H2O (SRS:10.6±4.1 vs 9.2±4.6;myocardial infarction area percentage:(15.2±9.0)％ vs (12.6±6.6)％;TPD:(11.6±6.3)％ vs (9.6±3.9)％;LVEF:(68.6±11.1)％ vs (71.4±11.3)％;t values:-2.33-2.75,all P＞0.05).Conclusions Comparing with 13N-NH3 · H2O,18F-Flurpiridaz has the advantages of good MPI image quality,accurate measurement of cardiac function parameters and quantitative potential of myocardial blood flow,which make it as a promising positron myocardial perfusion imaging agent.
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Objective@#To explore the biodistribution and quantitative value of 18F-Flurpiridaz in mini-swine, and compare with 13N-NH3·H2O.@*Methods@#Ten Bama mini-swine were divided into normal group and myocardial infarction group (n=5 in each group). Normal group was not treated and myocardial infarction group was modeled by thoracotomy and coronary artery ligation. Both groups were preceded by 13N-NH3·H2O imaging, followed by 18F-Flurpiridaz imaging (time interval >40 min). Injection dosage of 2 tracers was the same (185-370 MBq). 18F-Flurpiridaz whole-body PET/CT imaging was also performed in normal group. Biological distribution of 18F-Flurpiridaz was observed, and the ratio of radioactive uptake of 18F-Flurpiridaz between myocardium and adjacent tissues or organs was calculated. Image quality score and rest myocardial blood flow (rMBF) of 2 imaging tracers in normal group were measured and compared. MPI image quality score, cardiac function parameters such as summed rest score (SRS), myocardial infarction area percentage, total perfusion defect (TPD), and left ventricular ejection fraction (LVEF) of 2 imaging tracers were compared in myocardial infarction group. Data was analyzed by paired t test.@*Results@#In normal group, 18F-Flurpiridaz in the myocardium was clearly observed, with high radioactive uptake maintaining within 2 h postinjection. The radioactivity count ratios of left ventricular myocardium to cardiac pool, the lungs and liver were high (5.19-12.87, 4.17-50.51, 2.08-6.92). The quality of 18F-Flurpiridaz MPI images in both groups was excellent (10/10). The rMBF (ml·g-1·min-1) in different regions of left ventricle measured by 18F-Flurpiridaz and 13N-NH3·H2O imaging were not significantly different (left anterior descending: 0.98±0.06 vs 0.92±0.13; left circumflex: 0.98±0.05 vs 0.88±0.12; right coronary artery: 0.95±0.07 vs 0.88±0.15; left ventricle: 0.96±0.07 vs 0.90±0.13; t values: from -1.70 to -0.90, all P>0.05). There was no significant difference in SRS, myocardial infarction area percentage, TPD, rMBF or LVEF between 18F-Flurpiridaz and 13N-NH3·H2O (SRS: 10.6±4.1 vs 9.2±4.6; myocardial infarction area percentage: (15.2±9.0)% vs (12.6±6.6)%; TPD: (11.6±6.3)% vs (9.6±3.9)%; LVEF: (68.6±11.1)% vs (71.4±11.3)%; t values: -2.33-2.75, all P>0.05).@*Conclusions@#Comparing with 13N-NH3·H2O, 18F-Flurpiridaz has the advantages of good MPI image quality, accurate measurement of cardiac function parameters and quantitative potential of myocardial blood flow, which make it as a promising positron myocardial perfusion imaging agent.
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Objective The purpose of this study was to evaluate the hemodynamic effects of an extra-thoracic paraaortic counterpulsation device(ETPACD) with various capacities in an animal model with acute heart failure.Methods The acute heart failure model was successfully induced by snaring branch of anterior descending coronary artery in sheep(weighting 35-42 kg,n =8).The ETPACD is a single port,40 ml,60 ml and 80 ml stroke volume blood chamber designed to be connected to descending aorta through a valveless graft and placed extra-thorax.The hemodynamic indices of 40 ml,60 ml and 80 ml stroke volume were recorded respectively during counterpulsation assistance.Results 40 ml,60 ml and 80 ml ETPACD increased cardiac output 36.98％ (P =0.009),34.16％ (P =0.012) and 53.26％ (P =0.000) respectively,80 ml compared with 60 ml and 40 ml respectively P =0.001,P =0.005.And on diastolic mean aortic pressure 43.40％ (P =0.000)、63.20％ (P =0.000) and 78.76％ (P =0.000),80ml compared with 60ml and 40ml respectively P =0.329,P =0.025.The ETPACD (40 ml,60 ml and 80 ml) increased left carotid artery flow 45.19％ (P =0.007) 、61.51％ (P =0.001) and 81.50％(P=0.000),80 ml compared with 60ml and40 ml respectively P=0.016,P =0.000.Conclusion This study demonstrated that ETPACD (40 ml,60 ml and 80 ml) provided benefit of circulatory support in acute heart failure with better effect on hemodynamic parameters provided by 80 ml.Therefore,ETPACD with larger stroke volume may become a promising counterpulsation device for treatment of heart failure.
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ObjectiveAn out-thoracic paraaortic counterpulsation device(PACD) developed in the Reseach Center of our hospital was evaluated for its hemodynamic effects in an animal model with induced acute heart failure.MethodsEight healthy adult sheep with a weight of 38.5 to 54.5 kg were used as models for acute heart failure by snaring branches of coronary arteries.Thoracotomy was performed through the space under the left 4th rib.A Satinski clamp was used for partially clamping the descending aorta, and the Dacron vascular graft of out-thoracic PACD was sutured end-to-side to the descending aorta.The out-thoracic PACD used in this study had a blood chamber that was separated from the gas chamber by a movable polyurethane membrane .A stroke volume of 60 ml could be pumped when it was fully inflated.A 4F multipurpose catheter was inserted through the left ventricular apex for measuring and recording left ventricular pressures.A standard 40-ml intraaortic balloon was inserted into the descending aorta via the surgically exposed left femoral artery.Baseline hemodynamic data were collected after the model for acute heart failure was created without mechanical support.Mechanical support was randomly initiated either by the IABP or by the out-thoracic PACD in each experimental phase.Both devices were driven by the same console and synchronization with electrocardiogram was performed.Hemodynamic indexes and left carotid artery flow were calculated at baseline (device off) and during the period of 1 : 2 support for the 60-ml out-thoracic PACD and 40-ml IABP in the same animal.Baseline and support modes for devices were maintained for 15 minutes individually to ensure that a steady-state was achieved.ResultsBoth out-thoracic PACD and IABP resulted in a increase in the cardiac output (17.79％ with out-thoracic PACD vs.13.46％ with IABP, P =0.803) and the mean diastolic aortic pressure (29.48％ with out-thoracic PACD vs.15.01％ with IABP, P = 0.001).The use of out-thoracic PACD also led to a greater reduction in left ventricular end-diastolic pressure (35.09％ with out-thoracic PACD vs.15.79％ with IABP, P = 0.004).Meanwhile the out-thoracic PACD increased left carotid artery flow (14.52％ with out-thoracic PACD vs.6.70％ with IABP, P =0.006).No evidence of hemolysis, thrombus formation or major organ injury was identified during the experiment.ConclusionThe study indicated that a 60-ml out-thoracic PACD, which providing an improved mechanical circulatory support, was superior to a 40-ml IABP in the setting of experimental acute heart failure.This device may be used as a desirable alternative for the long-term mechanical support in patients with severe heart failure or those waiting for a heart transplantation, owing to its properties of low cost,easily to be implanted and removed, as well as a high biocompatibility.
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Objective To study the changes of reactive astrocytosis after heat shock protein 70 (HSPT0) was blocked by anti-HSP70 antibody. Methods We established cell model of scratch inju-ries by in situ culture and prurification of rat astrocytcs. Anti-HSP70 antibody was added into the nutrient medium at once after injury for intervention (intervention group). Then, immunocytochemical staining of glial fibrillary acidic protein (GFAP) was done at different time points in control group and intervention group to observe astrocytosis and morphologic changes, mRNA expression of GFAP was observed by means of reverse transcriptase-polymerase chain reaction (RT-PCR). Results Compared with the con-trol group, average cell area, average dentritic length and number of dentrities of astrocytes were signifi-cantly reduced in the intervention group(P < 0.05 or P < 0.01), with down-regulated mRNA expression of GFAP (P < 0.05). Conclusion HSP70 plays a facilitative role in reactive astrocytosis after injury of astrocytes. Reactive astrocytosis can be controlled to some extent by blocking HSP70 with anti-HSP70 antibody.