General knowledge on stem cells
Ok so you’re reading the newspaper or you’re watching the news and they’re talking about some new medical technology, some breakthrough treating congestive heart failure or re-growing muscle tissue in wounded soldiers. I bet that the story is going to mention that this new type of therapy uses stem cells
And like most people, you’re going to listen and just nod your head agreeably without actually knowing what stem cells are because who has time to know what stem cells are? Today, we’re sparing some time to learn those.
You have different types of stem cells in your body. They’re muscle cells, skin cells, liver cells, and brain cells. The basic cells that give rise to this type of cells in the organs are called stem cells.
Most of these cells have to be replaced once in a while. One type of stem cell is an egg cell from a woman that has been fertilized by a sperm from a man.
This single stem cell called zygote is a first cell in a developing human being. It’s also called toti-potent stem cells because it confirms any type of cell in the body as well as the umbilical cord and the placenta.
After a zygote has divided a few times, it becomes an early stage embryo called a Blastocyst. Embryonic stem cell comes from inside the blastocyst. Your taste-buds, for instance, are replaced every 10 days or so, skin cells are replaced every couple of weeks and liver cells turn over every 300-500 days.
Another one that are replacing the old ones and the repairing of damaged tissue are adult stem cells, also called somatic stem cells.
The different sorts of cells, skin cells, liver cells, retina cells, muscle cells and intestine cells, they have very specific jobs and they’re built in very specific ways to do those jobs, different shapes, sizes, contents.
It means you can’t just stick a muscle into a damaged liver and expect it to start breaking down your alcohol for you.
Somatic cells on the other hand haven’t decided what they’re going to be. They are undifferentiated. They haven’t specialized yet.
There are different types of adult stem cells some can become more different kinds of things than others.
Pluripotent adult stem cells can become many different types of stem cells all over the body, however, they’re really hard to track down because they are really few of them in each organ or tissue.
There are also multi-potent adult stem cells which are more common in the body but restricted in the kind of cell they can become.
It is kind of like the difference between graduating from trade school where you have been trained to do a few different possible jobs and graduating with the degree in philosophy i.e. equally unprepared for all jobs. So yes, stick a Pluripotent cell into a liver and it just happily becomes a liver cell.
Embryonic stem cells are Pluripotent. These are the cells inside a human embryo when it is a blastocyst, basically a tiny human cell of 4-5 days old which is destroyed in the process of removing the stem cells from inside it.
Those embryonic cells are obtained from in-vitro fertilization clinics that fertilize eggs outside of the mother’s body for couples who are having trouble conceiving.
Naturally these clinics have some left-over fertilized eggs so with the donor’s permission they are given to scientists doing stem cell research.
Now the main advantage of embryonic stem cells is that while adult stem cells can be grown in a culture for a time, meaning they can be multiplied over and over in a nutrient solution, they can’t grow as long or as fast as the embryonic cells which can be maintained indefinitely in the right condition.
After just 6 months in culture a single wad of 30 embryonic stem cells will have yielded millions of stem cells which can go on to develop into pretty much any type of cell in the body.
Also adult stem cells if used in some sorts of transplant therapies, it is more likely to be rejected than embryonic stem cells.
Embryonic stem cells are used by researchers all over the world to figure out how to repair or replace damaged cells and organ and create new drugs but regulations have taken their toll.
There are only about 35 stem cell lines of identical pluripotent stem cells that are available for federally funded research in America whereas Europe has couple thousand.