Left anterior fascicular block（LAFB） is a heart disease identifiable from an abnormal electrocardiogram（ECG）. It has been reported that LAFB is associated with an increased risk of heart failure. Non-specific intr...Left anterior fascicular block（LAFB） is a heart disease identifiable from an abnormal electrocardiogram（ECG）. It has been reported that LAFB is associated with an increased risk of heart failure. Non-specific intraventricular conduction delay due to the lesions of the conduction bundles and slow cell to cell conduction has also been considered as another cause of heart failure. Since the location and mechanism of conduction delay have notable variability between individual patients, we hypothesized that the impaired conduction in the ventricular myocardium may lead to abnormal ECGs similar to LAFB ECG patterns. To test this hypothesis, based on a computer model with a three dimensional whole-heart anatomical structure, we simulated the cardiac exciting sequence map and 12-lead ECG caused by the block in the left anterior fascicle and by the slowed conduction velocity in the ventricular myocardium. The simulation results showed that the typical LAFB ECG patterns can also be observed from cases with slowed conduction velocity in the ventricular myocardium. The main differences were the duration of QRS and wave amplitude. In conclusion, our simulations provide a promising starting point to further investigate the underlying mechanism of heart failure with LAFB, which would provide a potential reference for LAFB diagnosis.展开更多
Bacteria often use multiple transcription factors to regulate specific biological processes.Biosynthesis of heat-stable antifungal factor(HSAF)is regulated by multiple factors in Lysobacter enzymogenes.However,the mec...Bacteria often use multiple transcription factors to regulate specific biological processes.Biosynthesis of heat-stable antifungal factor(HSAF)is regulated by multiple factors in Lysobacter enzymogenes.However,the mechanism of HSAF biosynthesis regulation remains largely unknown.In this study,we screened a potential HSAF biosynthesis regulator,RecX,by a DNA pull-down assay.Deletion of recX resulted in a significant increase in the production of HSAF,and overexpression of recX significantly suppressed HSAF production.Importantly,our results showe that RecX directly binds to the promoter region of the lafB gene to inhibit its transcription and thus decreases HSAF production in L.enzymogenes.These findings reveal the novel mechanism of RecX regulation of antifungal antibiotic production in L.enzymogenes.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.61527811 and 61701435)
文摘Left anterior fascicular block（LAFB） is a heart disease identifiable from an abnormal electrocardiogram（ECG）. It has been reported that LAFB is associated with an increased risk of heart failure. Non-specific intraventricular conduction delay due to the lesions of the conduction bundles and slow cell to cell conduction has also been considered as another cause of heart failure. Since the location and mechanism of conduction delay have notable variability between individual patients, we hypothesized that the impaired conduction in the ventricular myocardium may lead to abnormal ECGs similar to LAFB ECG patterns. To test this hypothesis, based on a computer model with a three dimensional whole-heart anatomical structure, we simulated the cardiac exciting sequence map and 12-lead ECG caused by the block in the left anterior fascicle and by the slowed conduction velocity in the ventricular myocardium. The simulation results showed that the typical LAFB ECG patterns can also be observed from cases with slowed conduction velocity in the ventricular myocardium. The main differences were the duration of QRS and wave amplitude. In conclusion, our simulations provide a promising starting point to further investigate the underlying mechanism of heart failure with LAFB, which would provide a potential reference for LAFB diagnosis.
基金supported by the grants from the Natural Science Special Research Fund of Guizhou University,Special Post([2022]50)the National Natural Science Foundation of China(32260653).
文摘Bacteria often use multiple transcription factors to regulate specific biological processes.Biosynthesis of heat-stable antifungal factor(HSAF)is regulated by multiple factors in Lysobacter enzymogenes.However,the mechanism of HSAF biosynthesis regulation remains largely unknown.In this study,we screened a potential HSAF biosynthesis regulator,RecX,by a DNA pull-down assay.Deletion of recX resulted in a significant increase in the production of HSAF,and overexpression of recX significantly suppressed HSAF production.Importantly,our results showe that RecX directly binds to the promoter region of the lafB gene to inhibit its transcription and thus decreases HSAF production in L.enzymogenes.These findings reveal the novel mechanism of RecX regulation of antifungal antibiotic production in L.enzymogenes.
