Reliable infarction of the middle cerebral artery territory in C57BL/6 mice using pterygopalatine artery ligation and filament optimization – The PURE-MCAo model

Current techniques for inducing intraluminal filamentous middle cerebral artery occlusion (fMCAo) in mice produce highly variable results and often cause additional infarcts in the posterior cerebral artery (PCA) territory. The aim of the current study was to develop a novel procedure to overcome these shortcomings. Male C57BL/6 mice were subjected to 60 min of fMCAo with cerebral blood flow monitored by laser Doppler flowmetry. The influence of the length of the occlusion filament coating and the combination of common carotid artery (CCA) or pterygopalatine artery (PPA) ligation on lesion volume and functional outcome 24 h after reperfusion was evaluated. The use of appropriate filament and PPA ligation while maintaining CCA perfusion prevented the development of infarcts in the PCA area, resulted in pure MCA infarcts (68.3 ± 14.5 mm3) and reduced the variability of infarct volumes by more than half (from 26–38% to 14% standard deviation/mean). Using an improved fMCAo procedure, we were able to produce PCA area-unaffected reproducible (PURE) infarcts exclusively in the MCA territory. Thus PURE-MCAo reduced outcome variability by more than 50%. Our results may thus help to reduce the number of animals in preclinical stroke research and to increase the reproducibility of the fMCAo model

The effect of mindfulness-based interventions on telomere length and telomerase activity: A systematic review and meta-analysis

Systematic review and meta-analysis of the effect of mindfulness-based interventions on telomere length and telomerase activit

The effect of mindfulness-based interventions on telomere length and telomerase activity: A systematic review and meta-analysis

Systematic review and meta-analysis of the effect of mindfulness-based interventions on telomere length and telomerase activit

The Effects of Mindfulness-Based Interventions on Telomere Length and Telomerase Activity: A Systematic Review and Meta-Analysis

Abstract Objectives Previous meta-analyses suggested that mindfulness-based interventions (MBIs) may have beneficial effects on telomere length (TL) and telomerase activity (TA), two biological markers of cellular aging and cell stress. The present review aimed to provide the most comprehensive synthesis of the available evidence to date and tested a number of important effect moderators. Method Twenty-five studies (18 RCTs, 1 RCT and cohort study, 6 non-randomized studies) with 2099 participants in total were obtained with a systematic literature search, 10 studies had not been included in any previous meta-analysis. Effect sizes were aggregated with random-effects models, the risk of bias was evaluated with standardized checklists, and the most influential moderators were identified with a machine-learning approach. Results On average, MBIs had small-to-medium effects on TL (g = 0.23, 95% CI = [0.07, 0.39], p = 0.006) and TA (g = 0.37 [0.01, 0.73], p = 0.046), which, however, were driven by retrospective case–control studies with experienced meditators (TL) and by studies without control interventions and studies from Asia (TA). Most studies had an unclear risk of bias and low analytic power, and there was an indication of publication bias among the TL studies. Conclusions TL may not be a useful outcome to assess the efficacy of common MBIs. Effects on TA were smaller than previously assumed and may not be specific for MBIs; TA likely is increased by other active interventions as well. More high-quality and high-powered studies, which also apply open-science practices, are needed to move the field forward. </jats:sec