In order to evaluate the clinical significance of the acid-base disturbance complicating hepatic encephalopathy, arterial blood gas and electrolyte levels were determined in 33 patients with encephalopathy due to various hepatic disorders. It was found the respiratory alkalosis occurred in 31 cases(93.9%) and respiratory acidosis complicated with metabolic acidosis in 2 cases (6.06%). In the 31 cases of respiratory alkalosis, there were 4 cases(12.12%) of simple respiratory alkalosis, 18 cases(54.55%) complicated with metabolic alkalosis, 3 cases(9.09%) complicated with metabolic acidosis, and 6 cases complicated with both metabolic alkalosis and acidosis. In addition, the arterial blood pH of 29 cases (87.87%) was above the normal value of 7.45. The main type of acid-base disturbance found in hepatic encephalopathy was alkalosis. Its occurrence was closely related to hypoxemia, hyperammonemia, and elevated blood level of progesterone in the case of respiratory alkalosis and to salt-limited diet and improper administration of diuretics and alkalite drugs in the case of metabolic alkalosis. Metabolic acidosis was usually the result of severe complitions. In alkalosis, there was frequently an elevation of blood free ammonia, which could penetrate the blood-brain barrier easily and induce coma and encephalopathy. Therefore energetic correction of alkalosis would be valuable to prevent hepatic encephalopathy. Effective treatment of the primary disease, correction of hyperventilation.correction of disturbances of blood electrolytes, and administration of arginine hydrochloride and potasium chloride would be appropriate measures in dealing with alkalosis.

Objective To observe the changes of surface ECG and cell couplings between sinoatrial node cells and myocardial cells following transplantion of pedicled autologous sinoatrial node tissue graft into the right ventricle of a canine model of complete atrioventricular block. Methods Ten healthy dogs were randomized into transplantation group and control group. Pedicled autologous sinoatrial node tissue grafts were transplanted into the right ventricle in the transplantation group, while the sinoatrial nodes were only excised in the control group after placement of temporary myocardial pacing wires. The changes of surface ECG were observed at 1, 2, 3 and 4 weeks postoperatively. At 4 weeks, complete atrioventricular block was induced in the dogs by radiofrequency ablation of the His bundle. The heart rate of the dogs in both groups were recorded after the injection of isoproternol (ISO) from the femoral vein, and the transplanted tissue graft was observed under optical and transmission electron microscopes. Results No significant changes occurred in the surface ECG. All the dogs showed ECG waveforms specific of complete heart block after the ablation, and the ventricular heart rates were similar between the two groups (P>0.05). The ventricular heart rate did not undergo obvious changes after ISO injection (P>0.05). The transplanted pedicled autologous sinoatrial node survived in the dogs and the sinoatrial node cells established desmosome junctions with the myocardial cells, but the number of junctions was not sufficient to support heart pacing. Conclusions Desmosome junction can occur between ventricular myocardial cells and sinoatrial node cells at the edge of transplanted pedicled autologous sinoatrial node tissue.

Objective To observe the changes of surface ECG and cell couplings between sinoatrial node cells and myocardial cells following transplantion of pedicled autologous sinoatrial node tissue graft into the right ventricle of a canine model of complete atrioventricular block. Methods Ten healthy dogs were randomized into transplantation group and control group. Pedicled autologous sinoatrial node tissue grafts were transplanted into the right ventricle in the transplantation group, while the sinoatrial nodes were only excised in the control group after placement of temporary myocardial pacing wires. The changes of surface ECG were observed at 1, 2, 3 and 4 weeks postoperatively. At 4 weeks, complete atrioventricular block was induced in the dogs by radiofrequency ablation of the His bundle. The heart rate of the dogs in both groups were recorded after the injection of isoproternol (ISO) from the femoral vein, and the transplanted tissue graft was observed under optical and transmission electron microscopes. Results No significant changes occurred in the surface ECG. All the dogs showed ECG waveforms specific of complete heart block after the ablation, and the ventricular heart rates were similar between the two groups (P>0.05). The ventricular heart rate did not undergo obvious changes after ISO injection (P>0.05). The transplanted pedicled autologous sinoatrial node survived in the dogs and the sinoatrial node cells established desmosome junctions with the myocardial cells, but the number of junctions was not sufficient to support heart pacing. Conclusions Desmosome junction can occur between ventricular myocardial cells and sinoatrial node cells at the edge of transplanted pedicled autologous sinoatrial node tissue.

OBJECTIVETo observe the changes of surface ECG and cell couplings between sinoatrial node cells and myocardial cells following transplantion of pedicled autologous sinoatrial node tissue graft into the right ventricle of a canine model of complete atrioventricular block.

METHODSTen healthy dogs were randomized into transplantation group and control group. Pedicled autologous sinoatrial node tissue grafts were transplanted into the right ventricle in the transplantation group, while the sinoatrial nodes were only excised in the control group after placement of temporary myocardial pacing wires. The changes of surface ECG were observed at 1, 2, 3 and 4 weeks postoperatively. At 4 weeks, complete atrioventricular block was induced in the dogs by radiofrequency ablation of the His bundle. The heart rate of the dogs in both groups were recorded after the injection of isoproternol (ISO) from the femoral vein, and the transplanted tissue graft was observed under optical and transmission electron microscopes.

RESULTSNo significant changes occurred in the surface ECG. All the dogs showed ECG waveforms specific of complete heart block after the ablation, and the ventricular heart rates were similar between the two groups (P>0.05). The ventricular heart rate did not undergo obvious changes after ISO injection (P>0.05). The transplanted pedicled autologous sinoatrial node survived in the dogs and the sinoatrial node cells established desmosome junctions with the myocardial cells, but the number of junctions was not sufficient to support heart pacing.

CONCLUSIONDesmosome junction can occur between ventricular myocardial cells and sinoatrial node cells at the edge of transplanted pedicled autologous sinoatrial node tissue.

Animals ; Atrioventricular Block ; physiopathology ; surgery ; Cardiotonic Agents ; pharmacology ; Dogs ; Electrocardiography ; Female ; Heart Rate ; drug effects ; Heart Ventricles ; surgery ; Intercellular Junctions ; Isoproterenol ; pharmacology ; Male ; Myocardium ; cytology ; Sinoatrial Node ; cytology ; transplantation ; Tissue Transplantation ; Transplantation, Autologous

Given that current axial flow blood pumps have certain structural defects,resulting in poor performance and inferior blood compatibility,an integrated axial flow blood pump is developed,and its geometry is optimized using computational fluid dynamics method.The study also investigates the effects of different operational parameters on the performance of the blood pump and compares with experimental data to determine the optimal conditions.Additionally,the flow patterns of the blood pump are comprehensively analyzed for further revealing the internal flow phenomena,and the behavior of red blood cells in the blood flow and their response to shear stress are simulated using discrete phase model to evaluate the blood compatibility of the blood pump.The study shows that the novel blood pump performed well in terms of head.Under the optimal condition with a rotational speed of 9 000 r/min and a flow rate of 6.24 L/min,the blood pump improves the head by 16%as compared with the original structure,and reaches 25%efficiency,which can meet the physiological needs of most people.The pressure gradient and velocity gradient in most areas within the blood pump are smooth,and the internal flow patterns are generally stable,effectively avoiding the occurrence of hemolysis.The optimized blood pump can ensure high-level performance and favorable flow field characteristics while maintaining superior blood compatibility,which provides important reference for the structural optimization of axial flow blood pumps.

Objective: By modeling ischemic foot ulcers in experimental rabbits, the mechanism of healing in animal models was investigated. Methods: Sixty healthy male clean grade New Zealand rabbits were 3 months. The weight range was 2.1-2.5 kg. Randomly draw auording to the number, the experimental rabbits were randomly divided into 4 groups, namely, no ischemia-no ulcer-no intervention group (group A), no ischemia-no ulcer-no intervention group (group B), no ischemia-no ulcer-no intervention group (group C) and no ischemia-ulcer-intervention group (group D), with 15 rabbits in each group. Ischemic foot ulcers experimental rabbit building complete after 24 h, will naturally exposed ischemic foot ulcers in the low frequency electromagnetic field on experimental rabbit 7 d feeding experiment, the experimental rabbits ischemia crus muscle and the ulcer base were collected, and plasma by enzyme-linked immunosorbent assay (ELISA) verification tests in experimental rabbit plasma hypoxia-inducible factor 1 alpha subunit (HIF-1α), matrix metalloproteinases 9 (MMP-9) and soluble leukocyte differentiation antigen 40 ligand 1 (sCD40L1) expression level, while detecting ulcer healing area change, hematoxylin-eosin staining was used to detect and analyzed the pathological changes of ulcerated skin. Measurement data were expressed as mean±standard deviation (Mean±SD), one-way analysis of variance was used for comparison between groups, and LSD method was used for pairwise comparison. Results: The concentration of MMP-9 and sCD40L1 in group D were (40.510±10.155) ng/ml and (44.580±19.138) ng/ml, respectively. Concentrations in group C were (93.210±17.838) ng/ml and (318.500±52.680) ng/ml, respectively. Group D was significantly lower than group C, and the difference was statistically significant (P< 0.000 1). The concentrations of HIF-1α in group D was (249.700±71.824) ng/ml, and that in group C was (124.830±20.110) ng/ml. The concentration in group D was significantly higher than that in group C, and the difference was statistically significant (P< 0.000 1). The concentrations of HIF-1α, MMP-9 and sCD40L1 in group B were (181.590±31.927), (78.950±16.652) and (173.670±43.048) ng/ml, respectively. The concentrations of group A were (35.420±9.916), (32.700±6.449) and (47.440±11.831) ng/ml, respectively. The concentration in group B was significantly higher than that in group A, the difference was statistically significant(P<0.000 1). The concentration of HIF-1α in group D was (249.700±71.824) ng/ml, and the concentration of group A was (35.420±9.916) ng/ml. The concentration of group D was significantly higher than that of group A, and the difference was statistically significant (P=0.000 1). The concentration of the MMP-9 in the group D was compared with the concentration of group A, and the difference was not statistically significant (P=0.207). The concentration of sCD40L1 in group D was (44.580±19.138) ng/ml, and that in group A was (47.440±11.831) ng/ml. The difference between group D and group A was not statistically significant(P=0.858). The healing area of ulcer was (1.855±0.394) cm² in group D and (0.653±0.269) cm² in group C. Group D was significantly higher than group C, and the difference was statistically significant (P<0.000 1). Hematoxylin-eosin staining results of ulcer skin showed that the epithelial of ischemic foot ulcer was significantly atrophied, hyperkeratinized, and the acinous cell layer was atrophied with a small amount of obvious inflammatory cell infiltration and hyperplasia of small vessels. After intervention, the symptoms were relieved. Conclusion Low frequency electromagnetic fields can promote the expression of HIF-1α in experimental rabbits, inhibit the expression of MMP-9 and sCD40L1, and promote the healing of ischemic foot ulcer.