1.   Heart tissue has a complex architecture that includes blood vessels and connective tissue, as well as muscle cells.

2.   As a control experiment, they implanted miniature kidneys and heart tissue not from clones into the cows.

3.   A heart attack occurs when a blood flow stops because of a clogged blood vessel, often away from the heart, resulting in damage to heart tissue.

4.   Adenovirus causes colds, pinkeye and myocarditis, an inflammation of heart tissues.

5.   But heart muscle cells have been grown from mouse embryonic stem cells and successfully integrated with the heart tissue of a living mouse.

6.   But some evidence suggests that antibodies produced by the body to fight the bacteria also react with heart tissue.

7.   But studies have shown that parts of this protein elicit antibodies that react with heart tissue.

8.   Doctors hope to inject patients with stem cells, then signal them to grow into new heart tissue.

9.   In one of the studies, apparently functional heart tissue was regenerated from the injected cells, the first such success in some two decades of effort.

10.   Subsequent tests showed that his heart tissue was severely scarred.