It is fairly common knowledge that certain reptiles, such as the salamander, are able to regrow severed limbs. Such an ability has always been though impossible in mammals, including humans. But pioneering research by Robert O. Becker has shown that such an ability to regenerate limbs does exist in humans, albeit to a limited extent.
One of the most common reasons for children being admitted to hospital is the loss of a finger from some accident such as being wedged in a car door or sliced off by a fan. The standard technique is to just stitch some skin over the wound or, if the tip of the finger is still available, to rebuild the finger using microsurgery. Neither method results in a fully-functioning finger.
However, by pure accident Cynthia Illingworth at the Sheffield Children's Hospital noticed that in some children the finger would grow back. Just by doing nothing and letting the body heal itself, by 1974 Illingworth had documented hundreds of cases of regenerated fingers in children.
The criteria for this to happen are that just the tip of the finger be lost – the region from the fingernail down to the very first joint – and that the child be under eleven years of age. If the finger is sliced below the first joint then regeneration does not take place. If the skin is stitched back over the cut the finger will also not grow back. Also, the younger the child the quicker is the regrowth.
A small number of physicians took up this technique but further research was not funded. The term 'stem cell' is now in common use and this regeneration is the amazing ability of cells to not only differentiate from being a stem cell to one specific type, such as bone or cartilage or blood, but the ability for some cells to dedifferentiate from a specific type back into stem cells and then transform themselves into a different cell type. In the 1970's this was considered heretical, but even today the non-invasive techniques pioneered by Becker have been left to rot.
The Body Electric is a great book about what it is like to be a real scientist in pursuit of knowledge to help humanity. The grand thesis is that we are not just flesh and bones but also a complex and subtle electromagnetic system. The regeneration of a child's fingertip was proof that humans and salamanders had some common mechanisms. Becker was able to heal severely broken bones that would not heal naturally by the simple stimulation with a very low electric current. He was also able to destroy bacterial infections without antibiotics using similar methods. Read the book – it is eye-opening stuff.
Such simple yet powerful techniques should by now be in widespread use. Sadly they are not. We can all speculate on what vested interests are served by using complex surgery and pharmaceuticals instead of gently stimulating the body electric.