WORCESTER, Massachusetts -- A team of scientists at the Worcester Polytechnic Institute in Massachusetts transformed spinach leaves into beating heart tissue.First, they used detergent to strip the spinach leaves of their cells, making them translucent.Then, they seeded the spinach veins with human heart tissue.After several days, the muscle cells began to beat.If you watch closely, you can see the cells move as the red dye courses through the spinach veins.The scientists hope their research could one day help treat heart attack patients.