ABSTRACT
Introduction: Seed-based analysis has shown that transcutaneous auricular vagus nerve stimulation (taVNS) can modulate the dysfunctional brain network in patients with major depressive disorder (MDD). However, the voxel-based neuropsychological mechanism of taVNS on patients with first-episode MDD is poorly understood. The objective of this study was to assess the effects of an 8-week course of taVNS on patients with first-episode MDD. Methods: Twenty-two patients with first-episode MDD accepted an 8-week course of taVNS treatment. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were performed before and after treatment. Voxel-based analyses were performed to characterize spontaneous brain activity. Healthy controls (n=23) were recruited to minimize test-retest effects. Analysis of covariance (ANCOVA) was performed to ascertain treatment-related changes. Then, correlations between changes in brain activity and the Hamilton Depression Rating Scale (HAM-D)/Hamilton Anxiety Scale (HAM-A) remission rate were estimated. Results: Significant group-by-time interactions on voxel-based analyses were observed in the inferior ventral striatum (VSi) and precuneus. Post-hoc analyses showed that taVNS inhibited higher brain activity in the VSi, while upregulating it in the precuneus. Functional connectivity (FC) between the VSi and precuneus decreased. Positive correlations were found between the HAM-D remission rate and changes in brain activity in the VSi. Conclusion: taVNS reduced the FC between VSi and precuneus by normalizing the abnormal spontaneous brain activity of VSi in first-episode MDD patients.
ABSTRACT
Objective To quantitatively evaluate the associations of infarct size, regional myocardial function examined by cardiac magnetic resonance feature tracking (CMR-FT) strain analysis with infarct location in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention.Methods Cardiac magnetic resonance images were retrospectively analyzed in 95 consecutive STEMI patients with successful reperfusion. The patients were divided into the anterior wall myocardial infarction (AWMI) and nonanterior wall myocardial infarction (NAWMI) groups. Infarct characteristics were assessed by late gadolinium enhancement. Global and regional strains and associated strain rates in the radial, circumferential and longitudinal directions were assessed by CMR-FT based on standard cine images. The associations of infarct size, regional myocardial function examined by CMR-FT strain analysis with infarct location in STEMI patients were evaluated by the Spearman or Pearsonmethod. Results There were 44 patients in the AWMI group and 51 in the NAWMI group. The extent of left ventricular enhanced mass was significantly larger in patients with AWMI compared with the NAWMI group (24.47±11.89, 21.06±12.08 %LV; t=3.928, P = 0.008). In infarct zone analysis, strains in the radial, circumferential and longitudinal directions were remarkably declined in the AWMI group compared with the NAWMI group (z=-20.873, -20.918, -10.357, all P < 0.001). The volume (end-systolic volume index), total enhanced mass and extent of enhanced mass of the left ventricular were correlated best with infarct zone strain in the AWMI group (all P < 0.001). Conclusion In STEMI patients treated by percutaneous coronary intervention, myocardial damage is more extensive and regional myocardial function in the infarct zone is lower in the AWMI group compared with the NAWMI group.
Subject(s)
Humans , Anterior Wall Myocardial Infarction/therapy , ST Elevation Myocardial Infarction/pathology , Contrast Media , Retrospective Studies , Ventricular Function, Left , Magnetic Resonance Imaging, Cine/methods , Gadolinium , Magnetic Resonance Imaging , Myocardial Infarction/diagnostic imaging , Magnetic Resonance Spectroscopy , Percutaneous Coronary Intervention , Stroke VolumeABSTRACT
This study aimed to examine the functional role of microRNA-20 (miR-20) and its potential target,Kir6.1,in ischemic myocardiocytes.The expression of miR-20 was detected by real-time PCR.Myocardiocytes were stained with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) reagent for apoptosis evaluation.Western blotting was used to detect the Kit6.1 protein in ischemic myocardiocytes transfected with miR-20 mimics or inhibitors.Luciferase reporter gene assay was performed to confirm the targeting effect of miR-20 on KCNJ8.The results showed that miR-20 was remarkably down-regulated,while the KATP subunit Kir6.1 was significantly up-regulated,during myocardial ischemia.The miR-20 overexpression promoted the apoptosis of ischemic myocardiocytes,but showed no such effect on normal cells.Under ischemic condition,myocardiocytes transfected with miR-20 mimics expressed less Kir6.1.On the contrary,inhibiting miR-20 increased the expression of Kir6.1 in the cells.Co-transfection of miR-20 mimics with the KCNJ8 3’-UTR plasmid into HEK293 cells consistently produced less luciferase activity than transfection of the plasmid alone.It was concluded that miR-20 may regulate myocardiac ischemia by targeting KATP subunit Kir6.1 to accelerate the cell apoptosis.Therefore miR-20 may serve as a therapeutic target for myocardial ischemic disease.