Analysis of Morphology and Structural Remodeling of Astrocytes

Author(s):  
Tatjana C. Jakobs
2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Patrick Marx ◽  
Yu Sang ◽  
Hua Qin ◽  
Qingjing Wang ◽  
Rongkai Guo ◽  
...  

2012 ◽  
Vol 67 (6) ◽  
pp. 370-376 ◽  
Author(s):  
Cristina Granziera ◽  
Hakan Ay ◽  
Susan P. Koniak ◽  
Gunnar Krueger ◽  
A. Gregory Sorensen

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Smoczynska ◽  
H.D.M Beekman ◽  
R.W Chui ◽  
S Rajamani ◽  
M.A Vos

Abstract Background Atrial fibrillation (AF) is the most common cardiac arrhythmia treated in clinical practice. Structural remodeling is characterized by atrial enlargement and contributes to the therapeutic resistance in patients with long-standing AF. Purpose To study the atrial arrhythmogenic and echocardiographic consequences induced by volume overload in the complete chronic atrioventricular block (CAVB) dog. Methods Echocardiographic and electrophysiological data was obtained in 14 anaesthetized Mongrel dogs, in acute AV-block (AAVB), after 6 weeks of CAVB (CAVB6) and CAVB10. Left atrial (LA) volume was determined with 2D echocardiography by using the biplane method. An electrocardiogram and monophasic action potentials (MAP) at the right atrial (RA) free wall were recorded. Atrial effective refractory period (AERP) was determined by continuous programmed electrical stimulation (PES) of 20 beats with a cycle length of 400 ms and an extrastimulus with decremental design until refractoriness was reached. A continuous PES protocol of 20 beats with an extrastimulus 5 ms longer than the AERP was applied for 150 seconds to trigger AF. After 5 min without arrhythmias, autonomic neuromodulation was performed by intravenous infusion (IV) of acetylcholine (1,5μg/kg/min to 6,0μg/kg/min) for 20 min followed by prompt IV infusion of isoprenaline (3μg/min) until the atrial heart rate increased by 20 bpm. PES with an extrastimulus was repeated for 150 seconds to induce AF. Results LA volume increased from 13.7±3.2 ml at AAVB to 20.5±5.9 ml* at CAVB6, and 22.7±6.0 ml* at CAVB10 (Fig. 1A). AERP was similar at AAVB, CAVB6, and CAVB10 (115.8±11.9, 117.3±11.7, and 106.8±12.1 ms respectively). Repetitive AF paroxysms of >10 seconds were induced in 1/14 (7%) dogs at AAVB, 1/11 (9%) at CAVB6, and 5/10 (50%)* at CAVB10 (*p<0.05) upon PES (Fig. 1B). Combined neuromodulation and PES did not increase the AF inducibility rate, but prolonged the longest episode of AF in the inducible dogs from 55±49 seconds to 236±202 seconds* at CAVB10 (Fig. 1C). LA volume was higher in inducible dogs 25.0±4.9 ml compared to 18.4±4.2 ml in non-inducible dogs at CAVB10. Conclusion Sustained atrial dilation forms a substrate for repetitive paroxysms of AF. Neuro-modulation prolongs AF episode duration in susceptible dogs. This animal model can be used to study structural remodeling of the atria and possible therapeutic advances in the management of AF. Figure 1 Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Amgen Research


2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Janek Salatzki ◽  
Isabelle Mohr ◽  
Jannick Heins ◽  
Mert H. Cerci ◽  
Andreas Ochs ◽  
...  

Abstract Background Systemic effects of altered serum copper processing in Wilson Disease (WD) might induce myocardial copper deposition and consequently myocardial dysfunction and structural remodeling. This study sought to investigate the prevalence, manifestation and predictors of myocardial tissue abnormalities in WD patients. Methods We prospectively enrolled WD patients and an age-matched group of healthy individuals. We applied cardiovascular magnetic resonance (CMR) to analyze myocardial function, strain, and tissue characteristics. A subgroup analysis of WD patients with predominant neurological (WD-neuro+) or hepatic manifestation only (WD-neuro−) was performed. Results Seventy-six patients (37 years (27–49), 47% women) with known WD and 76 age-matched healthy control subjects were studied. The prevalence of atrial fibrillation in WD patients was 5% and the prevalence of symptomatic heart failure was 2.6%. Compared to healthy controls, patients with WD had a reduced left ventricular global circumferential strain (LV-GCS), and also showed abnormalities consistent with global and regional myocardial fibrosis. WD-neuro+ patients presented with more severe structural remodeling and functional impairment when compared to WD-neuro− patients. Conclusions In a large cohort, WD was not linked to a distinct cardiac phenotype except CMR indexes of myocardial fibrosis. More research is warranted to assess the prognostic implications of these findings. Trial registration: This trial is registered at the local institutional ethics committee (S-188/2018).


1995 ◽  
Vol 15 (1) ◽  
pp. 16-18 ◽  
Author(s):  
Wu Yong-ping ◽  
Che Dong-yuan ◽  
Zhang Wan-rong ◽  
Li Wen-ying

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Terrence Pong ◽  
Joy Aparicio Valenzuela ◽  
Kevin J Cyr ◽  
Cody Carlton ◽  
Sasank Sakhamuri ◽  
...  

Introduction: Spatiotemporal differences in atrial activity are thought to contribute to the maintenance of atrial fibrillation (AF). While recent evidence has identified changes in dominant frequency (DF) during the transition from paroxysmal to persistent AF, little is known about the frequency characteristics of the epicardium during this transition. The purpose of this study was to perform high-resolution mapping of the atrial epicardium and to characterize changes in frequency activity and structural organization during the transition from paroxysmal to persistent AF. Hypothesis: In a porcine model of persistent AF, we tested the hypothesis that the epicardium undergoes spatiotemporal changes in atrial activity and structural organization during persistent AF. Methods: Paroxysmal and persistent AF was induced in adult Yorkshire swine by atrial tachypacing. Atrial morphology was segmented from magnetic resonance imaging and high-resolution patient-specific flexible mapping arrays were 3D printed to match the epicardial contours of the atria. Epicardial activation and DF mapping was performed in four paroxysmal and four persistent AF animals using personalized mapping arrays. Histological analysis was performed to determine structural differences between paroxysmal and persistent AF. Results: The left atrial epicardium was associated with a significant increase in DF between paroxysmal and persistent AF (6.5 ± 0.2 vs. 7.4 ± 0.5 Hz, P = 0.03). High-resolution spatiotemporal mapping identified organized clusters of DF during paroxysmal AF which were lost during persistent AF. The development of persistent AF led to structural remodeling with increased atrial epicardial fibrosis. The organization index (OI) significantly decreased during persistent AF in both the left atria (0.3 ± 0.03 vs. 0.2 ± 0.03, P = 0.01) and right atria (0.33 ± 0.04 vs. 0.23 ± 0.02, P = 0.02). Conclusions: In the porcine model of persistent AF, the epicardium undergoes structural remodeling with increased epicardial fibrosis, reflected by changes in atrial organization index and dominant frequency.


2012 ◽  
Author(s):  
M. E. Rettmann ◽  
D. R. Holmes ◽  
M. S. Gunawan ◽  
X. Ge ◽  
R. A. Karwoski ◽  
...  

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