Cardiac magnetic field map topology quantified by Kullback-Leibler entropy identifies patients with clinically suspected myocarditis.

Background: Myocarditis is a condition that can have severe adverse outcomes and lead to sudden cardiac death if remaining undetected. This study tested the capability of cardiac magnetic field mapping to detect patients with clinically suspected myocarditis. This could open up the way for rapid, non-invasive, and cost-effective screening of suspected cases before a gold standard assessment via endomyocardial biopsy. Methods: Historical cardiac magnetic field maps (n = 97) and data from a state-of-the-art magnetocardiography device (n = 30) were analyzed using the Kullback-Leibler entropy (KLE) for dimensionality reduction and topological quantification. Linear discriminant analysis was used to discern between patients with ongoing myocarditis and healthy controls. Results: The STT segment of a magnetocardiogram, i.e., the section between the end of the S wave and the end of the T wave, was best suited to discern both groups. Using a 250-ms excerpt from the onset of the STT segment gave a reliable classification between the myocarditis and control group for both historic data (sensitivity: 0.83, specificity: 0.85, accuracy: 0.84) and recent data (sensitivity: 0.69, specificity: 0.88, accuracy: 0.80) using the KLE to quantify the topology of the cardiac magnetic field map. Conclusion: The implementation based on KLE can reliably distinguish between clinically suspected myocarditis patients and healthy controls. We implemented an automatized feature selection based on LDA to replace the observer-dependent manual thresholding in previous studies.

Preterm human amnion epithelial cells have limited reparative potential.

The collection and use of stem cells from the fetal membranes as cell therapy for a variety of lung diseases, including preterm lung disease, have been previously proposed. To date, only cells from term amnion have been assessed. In the setting of a future therapy for the preterm neonate, it would be ideal if autologous cells could be given. However, the reparative and anti-inflammatory actions of stem cells isolated from preterm amnions have not been evaluated. In this study, with a view to developing an autologous cell therapy for preterm lung injury, we compared the differentiation potential and efficacy of term versus preterm human amnion epithelial cells (hAECs) to protect against inflammation and fibrosis in a bleomycin mouse model of lung injury. We found that, unlike term hAECs, preterm hAECs did not differentiate into a lung lineage following culture in small airway growth media. Preterm hAECs also exerted significantly less protective effects than term hAEC following acute lung injury. Specifically, preterm hAEC did not improve Ashcroft scoring or collagen deposition in the lung despite a reduction in activated myofibroblasts. Term hAECs expressed double the levels of HLA-G compared to preterm hAECs. These findings indicate that while hAECs can be isolated from term and preterm amnions in similar numbers, they bear distinctive characteristics, which may impact upon their clinical use.