Grow Your Own Heart Valves 180
jcr writes "Medical researchers in Britain have succeeded in growing a heart valve from adult stem cells taken from bone marrow. The research is being reported in the journal of the Royal Society today. Growing a heart value from your own cells means that tissue rejection isn't an issue."
Re:Won't be legal in the US (Score:3, Informative)
Re:Whole heart next? (Score:5, Informative)
Until the last two or three years (if I remember correctly, the time frame may be off), with adult stem cells, they can grow a limited set of tissues only. Even now it takes work to make adult stem cells able to differentiate into any other cells. Embryonic stemm cells however can change into anything, without any modification. They are much easier to work with, and as of a couple of years ago they were the only option.
I can't remember if they can now make adult stem cells omni-potential, or just increase their potential to add just a few more cell types.
Re:Tissue Rejection Not an Issue (Score:5, Informative)
Re:Tissue Rejection Not an Issue (Score:2, Informative)
When I was getting ready to have my aortic valve replaced, the surgeon showed me a porcine valve; in appearance it is nothing like leather, but rather an incredibly thin and flexible structure. The aortic valve is not like a flap valve, but more like three little plastic grocery bags hung from the sides of a pipe. When blood flows one way, the leaflets collapse against the wall; when it flows the other way, whap, they fill up and block the tube.
There is no rejection problem with porcine or bovine heart valves because everything except the collagen has been chemically leached out of them; there's no distinctly cow/pig cell material left for the human immune system to react to. Same for a human-tissue replacement valve (harvested from a cadaver). Nevertheless, I think a lot of people opt for the mechanical valve (and a lifetime of coumadin) because of the "ick" factor.
The reliability figures I got from researching medical journals was that my porcine valve should last 15 years (not 5). At the time (2002) I told the doctor, "Great, by the time I need another, they'll be able to grow it from my own cells." I am just delighted this is proving to be true!
p. s. I also predicted that by 2017 they would be installing new valves using minimally-invasive, arthroscopic surgery -- not opening the chest like a book. There has been progress on that front, too...
Re:Whole heart next? (Score:3, Informative)
It wasn't meant in an angry tone. This is exactly a question, raised 1.5 years ago in my law school Health Law class, somebody else posed to a PhD Bio-ethicist. He avoided answering the question, and I thought somebody here could pose an answer. Whenever somebody's right of autonomy is stripped and the person reduced to property status, we call it slavery. (Voluntary renunciation of autonomy would be indentured servitude.) Arguably, the embryo is a person (or would be left to his one devices). Destroying the embryo to create stem cells is not voluntary, and it reduces the embryo to mere property. Thus, how is it not slavery?
The great question is "when does life begin?" The bio-ethicist argued after 21 days, and he based his argument on our decision point for when somebody is dead (e.g. brain activity, not "mostly dead/all dead"). My question to him was "what happens if we harvested all embryos before day 21?" (An obvious ad absurdium argument, but it underscores the distinction between establishing "life at 21" verse "death at no-brain function.) He ended up conceding that the 21 days was arbitrary.
As for baiting someone into a flamewar: by that definition, half of
Re:Whole heart next? (Score:3, Informative)
The clause, 'without any modification' is flat out wrong, applied to either type of stem cell.
I'm not a stem cell researcher myself, but It's my understanding that adult stem (AS) cells are actually easier to work with. In addition they're clearly more readily available. That being said, this is all the bleeding edge of medical and life science and *nothing* is 'easy'
I'll concede that ES cells certainly have the most potiential for manipulation, and there are valuable things to be learned about cell development from their study. However, this manipulation is difficult, at best, and from my own research, the resulting treatments are much more difficult to apply to human patients. (Less so where somehow a patient may have his/her own ES cells available, of course, but this is currently a rare occurrence)
God willing, (or science, if you prefer) we will soon have the break-throughs we so desperately desire for the treatment and cure to so many of the diseases you read about in the news. Whether it comes from ES or AS cells, or some other unrelated research doesn't much matter except to those who care more for politics than saving lives.
I will freely disclose that I morally oppose ES cell research when the cells are obtained through IVF, cloning, and abortions, but that is mainly because I morally oppose those procedures. HOWEVER, my beliefs are my own, and I have no problem that other people do not share those beliefs. I only care about the truth and moral and intellectual honesty, both of which tend to be cast aside by ideologues on both sides of this particular issue.