It is usually seen that when there is a cut on the finger, the skin on it is replaced after some time. Similarly if, due to some injury bleeding has occurred, body can very well replenish the stock of blood cells through the self capacity of the body to form new blood cells. But this may not happen, if a body part is lost. There are no new fingers formed once again if one is lost in an accident. Also a badly burnt skin can not grow again, though irreparable scars can exist.
Stem cells Research promises to help people for the loses due to many such non-rewinding mishaps. Not only reformation of lost body parts, stem cells can cure diseases like Leukemia, Alzheimer's disease, diabetes, heart strokes etc. Stem cell therapy can regenerate the brain cells which may die in Alzheimer's disease. Similarly in the case of Leukemia, where the white blood cells suffer, is treated by killing the cancerous cell, can also be cured by stem cells.
Heart diseases which take a toll of a good number of people in America can be dealt through the adult stem cells. Heart strokes, whenever they happen, leave the patient's heart damaged and in such cases the tissues of the heart have to replaced. Researches have proved that injecting ones own stem cells in the heart can produce the cells effectively. As the body may not always adjust to some foreign tissues, employing ones own tissue to replace the damaged ones is a safer bet. There is always a check by the body to verify anything new that is introduced in it.
Embryonic stem cells are also an option for building up damaged cells. The answer to lost body parts are found in therapeutic cloning. In this process cells of the damaged body parts are extracted from the growing embryo and are injected to form the new copy of the body part.