Stem Cells 101

With the recent news that scientists have seemingly reversed paralysis in rats with stem cell therapy, most people, while intrigued, don't really know what stem cell therapy is. Here is a look at this amazing technology and its uses.

What Are Stem Cells?

The human body has dozens of different types of cells—over 200 hundred in fact. There's peripolar cells, which make up the kidneys. There's white blood cells, monocytes, which are part of the immune system, among other things. Microglial cells are part of the central nervous system. Every one of these specialized cells is generated from the zygote, the single cell that results when a sperm cell unites with an egg. The zygote then quickly develops, dividing itself over and over until it becomes a ball of cells known as a blastocyst. This blastocyst contains all of the cell types necessary to make a human being, including the cells that build the placenta and umbilical cord. At this point these cells, called totipotent cells, the ones that form the placenta and umbilical cord, are no longer present. Instead, the cells are multipotent, which means they can each generate a few different types of specialized cells.

Stem cells are able to replicate, making copies of themselves, and stem cells can differentiate into the specialized cells needed to make up the human body's organs, skin, and all of the required life systems. The stem cells that are in your body from the fetal stage through adulthood are these specialized cells, and they can change as one ages.

How Are Stem Cells Used To Treat Medical Conditions?

Stem cell therapy is relatively new to the medical world, having only been in existence outside the laboratory for about thirty years. The most common use is in the treatment of cancers like leukemia and lymphoma. The traditional treatment for these diseases, chemotherapy, presents with significant side effects, namely it cannot distinguish between healthy cells and cancerous cells. Because of this cytotoxicity, healthy cells are killed right along with the cancerous cells. With stem cell therapy, healthy bone marrow cells from a donor are given to the patient. The new cells replace the dying cells, and they also stimulate the body's immune system. This generated immune system response then works to kill the cancerous cells.

Scientists are hard at work researching the other ways stem cells can be used to treat diseases such as Parkinson's disease, Alzheimer's disease, brain and spinal cord injuries, diabetes, arthritis, AIDS, and more.