Failing Heart Cells (IMAGE) Cincinnati Children's Hospital Medical Center Caption This microscopic image shows a population of donated heart cells from an adult heart failure patient who underwent reparative surgery. The purity of the failing fibroblast cells was confirmed by testing for fibroblast markers vimentin and actin (red and green colors, respectively). Researchers tested an experimental treatment for cardiac injury in the cells in research published by the Journal of the American College of Cardiology. Credit Cincinnati Children's Usage Restrictions Must credit image to Cincinnati Children's. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.