okay, I was in the US last week and got to see those lovely campaign, mud-slinging adverts. One of these mentioned a certain gubenatorial (sp) candidate was against stem cell research.

Color me stupid (again), but where do these mysterious stem cells come from? Aren't they taken from the placenta that gets thrown out anyway?

I don't intend for this to be a debate over whether stem cell research is good/bad. I just have this question. TIA. :)

Stem cells can come from various places, and the placenta is one of them (I think you can also get some from the umbilical cord). But the most useful stem cells unfortunately do come from fetuses, hence the controversy.

They are foetus that would be discarded anyways due to women having abortions. Scientists don't go around stealing babies from mums, they just harvest the unwanted babies - ie aborted foetus etc.

You can get them from placenta, umbilical cord, bone marrow, early human embryo. The last one is the controversial one, but also the most valuable to research. They are still finding new sources for stem cells, but nothing will have the ultimate potential of an embryonic stem cell. :)

(I think you can also get some from the umbilical cord) Yes you can, I read pretty recently that some English soccer (or football) players were storing stem cells from their childrens umbilical cords in case they got hurt.

Thanks all. You are so smart. :thumb: Now I am, too.

I'm pretty sure that they can be harvested from a certain area of the brain even in adulthood.

There are adult stem cells, although I never heard of harvesting them from the brain. I could be wrong though.

I agree that the debate comes from using embryonic stem cells, because one of the sources for embryonic stem cells are abortions. However, even if you are against abortion, most people who are against stem cell research are opposed to using any embroyonic stem cells regardless of where they come from. Every day fertility clinics throw out unused human embryos, ones that were produced by couples who have since got pregnant and will not use the embryos. It's the dumpster or research, and I can't understand why some people will chose the dumpster.

I agree. Since they were going to be aborted anyway, and since they are no longer living, why not harvest them? Less meals for rats...

I am very pro stem-cell research. The explanation I have heard for people being against using embryonic stem cells is that they are concerned people would sell them like some people sell their blood.

Ok, I happen to know a bit about this issue, so I'll clear some things up.

Every adult has stem cells dedicated to every tissue type in their body, meaning you have bone marrow stem cells that can produce more bone marrow, you have brain stem cells that can produce more brain cells (albeit very slowly), and so on. Everyone has them, and they can be harvested, though some would kill the patient if you tried, like brain stem cells. These can still be harvested from corpses if it is done quickly enough. These can only produce one type of cell and there are issues with tissue compatability.

More generalized stem cells (ones that can produce different types of cells and even more stem cells) can be harvested from the placenta, the umbilical cord, and the embryo (if it is harvested at an early stage, the more develped the foetus is, the more of these cells have become specialized). The embryo has the most and they are the most versatile, with the lowest risk of tissue rejection.

There are serious problems with the embryonic stem cells (the ones that are being debated over, I don't think anyone has a problem with umbilical cord stem cell research). The first is that it requires killing a living embryo. On top of that, with laws on this area being unclear, there are fears that women will get pregnant just to sell the embryo to the researchers, or that researchers will fertalize and grow the embryos in-vitro specifically for that purpose. This is the bulk of the controversy.

The other serious problem with embryonic stem cells is that they are unpredictable. If these cells are placed in the brain of someone with Alzheimer's, for example, they are more likely to cause seisures than to cure the Alzheimer's. They also have a nasty tendency to turn into tumors. Scientists are confident they can work around this, but there hasn't been much improvement yet. The other types of stem cells almost never do this, so there is a growing non-religious movement to ban embryonic stem cell research in order to move the focus onto the other types of stem cells. These are harder to get, and have more issues with rejection, but seem far less likely to cause drastic side-effects.

True, should have remembered that. Embryonic stemcells are for anything. They have the possibility to become anything, where as those found in adult tissue are specific in their intent, they will do what theyre intended to do.

If I recall correctly from my psyc lectures then there are areas on the surface of the human brain in certain areas that are similar to embryonic stemcells but without the high unpredictability. Theyre unpredictable but not as unpredictable as embryonic stemcells.

On the other hand there hasn't been as much opportunity to conduct research with embryonic stem cells as plenty of countries ban it...

I'm under the impression that they aren't gained through abortions but from leftover IVF embryos. Getting them through abortions sounds unnecessarily messy and difficult...

What is the earliest stage that stem cells can be taken from embryonic material?

Is it possible to make pre-living embryo for the sole purpose of stem cell harvesting? Or is that in with the 'when does life begin' argument?

If there is a way of harvesting these cells that doesn't bother the majority in a population, then the possibilities are endless. Who knows what we will achieve?

Is it possible to make pre-living embryo for the sole purpose of stem cell harvesting? Or is that in with the 'when does life begin' argument? Bingo. For those who believe that life begins at conception, this arguement falls apart. Obviously, you need a post-conception fertilized egg before you can start getting stem cells.

I'm under the impression that they aren't gained through abortions but from leftover IVF embryos. Getting them through abortions sounds unnecessarily messy and difficult... Leftover IVF embryoes are by far the most desirable choice, but the problem with that is it's currently illegal in the U.S. There is a ban on transferring or selling any body part (which these embryos are considered) to some other party, meaning it's actually illegal for someone to donate the embryos, which they have no intnetion of ever using, for scientific research.

I thought it was only illegal to sell them. I thought you could donate them, such as donating your body to science when you die, but trying to make profit off it was the illegal part.

There was legislation earlier this year in Congress that would have allowed the donation of unused embryos (provided you did not profit from it, as you said), but Bush vetoed it, and it didn't get the 2/3 majority needed to override the veto. So no, you can't donate them even.

Anyway, regardless of the morality of it, there are other reasons to restrict embryonic stem cell research.

Is it possible to make pre-living embryo for the sole purpose of stem cell harvesting? Or is that in with the 'when does life begin' argument? Strictly speaking, the tissue has to be living or it is pointless. We're talking about putting living cells into a person with the express intent that those cells grow and replicate. The issue of when it becomes a distinct, seperate individual is another issue.