Background Atrial tachyarrhythmia (AT) is a common complication in patients who have undergone a Fontan operation. In this study, we investigated whether abnormal Ca2+ handling contributes to the Fontan operation-rela...Background Atrial tachyarrhythmia (AT) is a common complication in patients who have undergone a Fontan operation. In this study, we investigated whether abnormal Ca2+ handling contributes to the Fontan operation-related atrial arrhythmo-genic substrate. Methods Mongrel dogs were randomly assigned to sham and Fontan groups. The Fontan operation model was developed by performing an atriopulmonary anastomosis. After 14 days, an electrophysiological study was performed to evaluate the AT vulnerability. Ca2+ handling properties were measured by loading atrial cardiomyocytes (CMs) with fura-2 AM. The L-type Ca2+ (ICa?L) and Na+–Ca2+ exchanger (INCX) currents of the CMs were recorded by the whole-cell patch-clamp technique. The key Ca2+ handling proteins expression was assessed by Western blotting. Results The AT inducibility was higher in the Fontan group than in the sham group (85.71 vs. 14.29%, P < 0.05). The Fontan operation resulted in decreased Ca2+ transient (CaT) amplitude and sarcoplasmic reticulum (SR) Ca2+ content, but in enhanced diastolic intracellular Ca2+ concentration and SR Ca2+ leak in the atrial CMs. The spontaneous CaT events, triggered ectopic activity and INCX density were increased, but ICa?L density was reduced in CMs from the Fontan atria (all P<0.05). Additionally, the Fontan operation resulted in decreased SR Ca2+ ATPase expression and Cav1.2 expression, but in increased NCX1 and Ser2814-phosphorylated ryanodine receptor 2. The calmodulin-dependent protein kinase II expres-sion and function were markedly enhanced in the Fontan atria. Conclusion The Fontan operation caused atrial CM Ca2+ handling abnormalities that produced arrhythmogenic-triggered activity and increased vulnerability to AT in experimental Fontan dogs.展开更多
To realize and raise sharing property of database′s resource, it is necessary to introduce concurrent operation. But without control on the concurrent operation, it will result in a series of problems. This paper ana...To realize and raise sharing property of database′s resource, it is necessary to introduce concurrent operation. But without control on the concurrent operation, it will result in a series of problems. This paper analyses the causes leading to these problems with the example, and sets up Petri Nets models based on both trasaction control and activity control according to the characteristics of the Petri Nets to solve the problems.展开更多
In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reordin...In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.展开更多
文摘Background Atrial tachyarrhythmia (AT) is a common complication in patients who have undergone a Fontan operation. In this study, we investigated whether abnormal Ca2+ handling contributes to the Fontan operation-related atrial arrhythmo-genic substrate. Methods Mongrel dogs were randomly assigned to sham and Fontan groups. The Fontan operation model was developed by performing an atriopulmonary anastomosis. After 14 days, an electrophysiological study was performed to evaluate the AT vulnerability. Ca2+ handling properties were measured by loading atrial cardiomyocytes (CMs) with fura-2 AM. The L-type Ca2+ (ICa?L) and Na+–Ca2+ exchanger (INCX) currents of the CMs were recorded by the whole-cell patch-clamp technique. The key Ca2+ handling proteins expression was assessed by Western blotting. Results The AT inducibility was higher in the Fontan group than in the sham group (85.71 vs. 14.29%, P < 0.05). The Fontan operation resulted in decreased Ca2+ transient (CaT) amplitude and sarcoplasmic reticulum (SR) Ca2+ content, but in enhanced diastolic intracellular Ca2+ concentration and SR Ca2+ leak in the atrial CMs. The spontaneous CaT events, triggered ectopic activity and INCX density were increased, but ICa?L density was reduced in CMs from the Fontan atria (all P<0.05). Additionally, the Fontan operation resulted in decreased SR Ca2+ ATPase expression and Cav1.2 expression, but in increased NCX1 and Ser2814-phosphorylated ryanodine receptor 2. The calmodulin-dependent protein kinase II expres-sion and function were markedly enhanced in the Fontan atria. Conclusion The Fontan operation caused atrial CM Ca2+ handling abnormalities that produced arrhythmogenic-triggered activity and increased vulnerability to AT in experimental Fontan dogs.
文摘To realize and raise sharing property of database′s resource, it is necessary to introduce concurrent operation. But without control on the concurrent operation, it will result in a series of problems. This paper analyses the causes leading to these problems with the example, and sets up Petri Nets models based on both trasaction control and activity control according to the characteristics of the Petri Nets to solve the problems.
基金supported by the National Natural Science Foundation of China (Grant Nos.31371106 and 91632110)HZAU Independent Innovation Fund (2014BQ019).
文摘In vito fber photometry is a powerful technique to analyze the dy namics of population neurons during fiunctional study of neuroscience.Here,we introduced a detailed protocol for fiber photometry-based calciun reording in freely moving mice,covering from virus injection,fiber stub insertion,optogenetical stimulation to data procurement and analysis.Furthemnore,we applied this protocol to explore neuronal activity of mice latenal-posterior(LP)thalaric nucleus in response to optogenetical stimulation of primary visual cortex(V1)neurons,and explore axon clusters activity of optogenetically evoked V1 neurons.Final confirmation of virus-based protein expression in V1 and precise fber insertion indicated that the surgery procedure of this protocol is reliable for functional calcium recording.The scripts for data analysis and some tips in our protocol are provided in details.Together,this protocol is simple,low-cost,and effective for neuronal activity detection by fiber photometry,which will hep neuroscience researchers to carry out fiunctional and behavioral study in vivo.
