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Successful Stem Cell Replacement of Windpipe
thepacketmaster writes "In what is being hailed as a medical milestone, CNN reports a woman suffering from long-term tuberculosis had her lower trachea and bronchial tube replaced by tissue grown from her own stem cells. A team from the universities of Barcelona, Spain; Bristol, England; and Padua and Milan, Italy, decided to go ahead with the surgery instead of having to remove her left lung. The operation, reported Wednesday in the British medical journal The Lancet, has been hailed as a major leap for medicine that could offer new hope for patients suffering from serious illness."
FTA:
While this procedure still does require a donor organ, it basically only uses the donor as a collagen framework to grow the patient's cells into.
Could the next step be fabricating the collagen frame, perhaps through 3D printing?
Your mind is clear / The things that you fear / Will fade with how much you / Believe what you hear
I found this part at least as interesting as the stem cells:
To create the new windpipe, the team took a seven-centimeter (2.75-inch) segment of trachea from a 51-year-old who had died. Over a six-week period, the team then removed all the cells from the donor trachea, because those cells could lead to rejection of the organ after transplant.
All that remained of the donor's stripped-down trachea was a matrix of collagen, a sort of scaffolding onto which the team then put Castillo's own stem cells -- along with cells taken from a healthy part of her trachea.
So there's still a donor involved, but there's less risk of rejection. We're still a ways from growing sophisticated organs from scratch, but this is an interesting implementation detail.
From what some friends of mine at Bristol Uni have been saying, yes this was done with non-embryonic stem cells, but embryonic stem cells would raise the likelihood of success in such cases as they are more likely to adapt to the required level.
And as to whether or not usage of embryonic stem cells is morally questionable, doesn't that depend on a huge set of variables, such as how the cells are harvested (you can save embryonic stem cells from the birth of a living baby for example), and your own personal beliefs?
If they're replicating stem cells from people who are already at high risk of breast cancer, doesn't that increase it even more (more generations == shorter telomeres)?
Not really. Stem cells, like most cancer cells, produce telomerase and tend to have significantly longer telomeres than surrounding tissue. While this declines slowly with age, the cells in waist fat should be no more dangerous than those in breast fat in the same person.
Oh, and I'm not aware of any definitive link between breast size and cancer risk, so I have no idea if transferring fat from the waist -- who hears talk of belly fat cancer? -- to the breasts poses ay risk in itself. I doubt it, though.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
I'm a biologist. I consider an undifferentiated ball of frog cells at the equivalent stage a frog individual. Later this week my students will be using corn kernals in a genetics experiment, because they are individual corn plants. Why make an exception for humans? Now, you can argue about wheather undeveloped humans deserve protection, but that they are human on a basic level isn't at issue.
but embryonic stem cells would raise the likelihood of success in such cases as they are more likely to adapt to the required level.
IANAB (I am not a biologist), but if the possibility set of the patient-harvested polypotent stem cells include trachea cells, I don't see why you would need pluripotent stem cells in order for it to be a "success"?
Sadly, your friends are wrong in that if embryonic stem cells had been used in this case, that it somehow would have had a higher chance of success. The very fact that the safer and stabler ASCs (adult stem cells) were used in this operation means that the patient won't reject the organ, and the patient won't get cancer. Embryonic stem cells are too unstable in their pluripotency for them to be usable, and always go cancerous (tumor rates is one of the measures that is used to determine how well the embryonic cells have been accepted by the test mice/rats -- more tumors means that more embryonic cells lived).
you can save embryonic stem cells from the birth of a living baby for example
Sorry, but you cannot harvest truly pluripotent cells without destroying the embryo. You can get polypotent ASCs that are very nearly the equivalent of pluripotent embryonic stem cells by using cord blood stem cells, but you cannot actually gain pluripotent stem cells without destroying the living organism.
This is why many people (such as myself) are truly puzzled as to why so many people aren't more excited about ASC research -- it is usable today, and the cancer and rejection risks are so much lower than ESCs. As you noted, ASCs harvested from live births through cord blood have more than enough polypotency to treat even many neurological disorders, and they are far superior in their cancer-potential-stability.
Therapeutic cloning has a host of problems all its own -- in addition to the fact that "there is no such thing as a normal clone", the large number of donor embryos that would be required for ever person treated. We have a limited supply of unused living human embryos that we've built up over the years through IVF treatments, but if therapeutic cloning became widespread, there's no way IVF surplus would keep up with the demand. Harvesting aborted humans is another option, but that wouldn't work so well for the cloning part since the aborted organism is largely dead, and is often aborted later on in the development cycle, when performing a wholesale cloning operation is no longer feasible (though I've heard things about some clinics being able to offset costs by selling aborted human embryonic biomatter for research).
Cord blood is a great way to get near-pluripotent ASCs that still maintain most of an ESC's potentiality, but have increased availability and the added stability of being further on down the specialization line. Increased supply means increased odds of finding a matching donor (similar to how bone marrow transplants are done today).