{'fraction_non_alphanumeric': 0.039483675018982534, 'fraction_numerical': 0.012148823082763858, 'mean_word_length': 5.793814432989691, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
University of Groningen Molecular adaptations in human atrial fibrillation Brundel,

Background: Atrial fibrillation (AF) is accompanied by electrical, structural and ion-channel protein remodeling. We tested whether calcium activated neutral protease, calpain, is involved in AF-induced remodeling. Therefore, calpain activity and localization in atrial tissue of patients with paroxysmal and persistent AF were determined, and correlated with remodeling processes. Methods and Results: Right atrial appendages were obtained from patients with paroxysmal (n=7, PAF), persistent (n=10, CAF) lone AF and controls in sinus rhythm (n=10) and used for measuring tissue calpain activity with a fluorogenic calpain specific substrate. Calpain I localization was studied by immunohistochemistry. Ion-channel protein expression was determined by slot-blot analysis. Structural changes were quantified by counting atrial myocytes showing degeneration or hibernation. Rate adaptation was calculated from atrial effective refractory periods (AERPs) at 5 basic cycle lengths. Tissue calpain activity was significantly increased in PAF (2-fold, p<0.001) and CAF (3-fold, p<0.001), mainly due to calpain I activation. Calpain I was localized in the cytosol, intercalated discs and nucleus of cardiomyocytes. Patients with AF showed