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Fully Functional Bioengineered Tooth Grown In a Mouse
A couple of weeks back the Wall Street Journal reported on the first organ grown in vivo from stem cells — a tooth in the mouth of a mouse. Reader cdrpsab spotted the news on the MedGadget blog; the research had been reported earlier in the PNAS. From the WSJ: "The researchers at the Tokyo University of Science created a set of cells that contained genetic instructions to build a tooth, and then implanted this 'tooth germ' into the mouse's empty tooth socket. The tooth grew out of the socket and through the gums, as a natural tooth would. Once the engineered tooth matured, after 11 weeks, it had a similar shape, hardness and response to pain or stress as a natural tooth, and worked equally well for chewing. The researchers suggested that using similar techniques in humans could restore function to patients with organ failure."
Of course, we all grow teeth at the beginning of our lives, but this friend of mine grew a new tooth when he was in his thirties. He had an extraction, and about two years later, a new one came in. He wasn't one of those people who start out with three ranks of teeth (that's pretty rare too, but not quite as rare a growing a new one as an adult. I think his case got written up in some dental journal.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
They're horrible, and I live in the United States, a culture where teeth are perfect and white or you are nothing. My wife has beautiful teeth, and despite the fact that we have nearly identical brushing and dental care habits, my teeth are horrid, yellow, and falling to pieces, hers are beautiful, white, and basically no cavities.
Sorry - not all teeth are created equal.
So here I am, 30-something, fairly affluent, and having horrid teeth. You think I wouldn't hesitate to spend a few Gs replacing my craptastic old teeth with new teeth with zero chance of rejection? Sure, they will go yellow quickly, just like the last ones did, but that means I'm in my 80s or later before my teeth are in any way unusual. And effectively, that means good teeth for life.
I've been waiting for this kind of treatment. Where do I sign up?
I have no problem with your religion until you decide it's reason to deprive others of the truth.
The problem with growing organs is that in order to get cells to multiply you have to disable certain genes in those cells, or at least reset their counters. Which genes ? Well those that guard against cancer ...
Our bodies go to great lengths to prevent cells from multiplying anywhere and it is only allowed by the human DNA in very specific cases : blood production in the bone marrow, when a woman becomes pregnant, and just before a woman gives birth. There are others, but those are major modifications of human cell's normal reproduction. The body goes to great lengths to prevent cell division in organs once a human being is born, instead choosing to do the bulk of the necessary divisions before birth and then letting those already-existing cells enlarge instead of divide to make a child grow. That's not to say there is no cell division involved in growing a child, but a lot less than you'd think from the size difference.
All 3 of those exceptions are also major causes of cancer : leukemia, endometrial cancer and breast cancer.
Getting stuff to grow is easy, just kill of the p70 gene. Getting stuff to grow safely is hard. Very very hard. Loads of research still need to be done before this can really be risked in a live human being.
As a Type 1 diabetic myself it really makes my day when something new and cool like this pops up on my screen. I vaguely remember some doctor-or-some-such saying a few years back that diabetes is a disease that should have been cured (or at least fixable) 30 years ago. If not for the fact that medical companies have an income from insulin, needles, and other paraphernalia as stable as WoW subscriptions and probably a goodly bit bigger, it probably would have. Though I am pleased to see there have been actual, tangible improvements made in the few years I've lived with this damned malfunction, it scares and annoys the hell out of me that all the big money goes into making a disease/malfunction that kills more people than either cancer or AIDS a bit more manageable instead of fucking fixing it.
Fix 1 (don't know the current status of gene replacement therapy, but seems doable):
Why can't they just get the DNA of some thousand diabetes type 1 patients and healthy people on record, analyze it for the bits that stick out in diabetics, and use a virus to replace the defect bits? Isn't this the general idea behind gene replacement therapy? Follow up with auto-immune drugs used for transplant patients so we get rid of all the T-cells made for killing insulin producing cells, and transplant/grow a pancreas. I don't know.. it seems so god damned simple, yet IAJARG (I Am Just Another Random Geek) so I'm probably wrong.
Fix 2 (bit of a hazzle, but uses everyday techniques that any semi-large hospitals should have expertise on):
What about this? Transplanted organs are rejected by the auto-immune system. The little bastards are produced in the bone marrow (right?). This would mean that if my entire auto-immune system is wiped clean (with drugs every hospital has) and my bone marrow is replaced with donated marrow from a healthy person, I would in effect have that persons auto-immune system. As far as I can see, the new bone marrow isn't going to reject itself. It might reject the entire body it has been transplanted into but blood cancer is one of the least fatal cancers these days, right? Bone marrow transplant can't be that dangerous..? Again, transplant a pancreas (preferably from the same donor) or grow a new one. A couple of years of vaccinations and being sick and on antibiotics 24/7 later.. Voila, defective auto immune system is out, new one is up and running, new pancreas is in and the damned immune system doesn't attack it!
Could someone smarter than me please inform me why a disease, seemingly so simple to fix, remains uncured to this day with no big breakthroughs on the up-and-coming? Everyone gets their dose of daily cancer/AIDS/COPD/anti-drug propaganda. Everyone gets a visit now and then from someone collecting money for cancer research projects. At the same time, most people I talk to think diabetes means I have to take one shot a day (or a few pills) and the reply to how serious a condition it actually is usually boils down to "You can die from diabetes..? *disbelief*", "You sure you aren't making that up?" or "LOL, why haven't I ever heard of anyone dying of it then?".
My ex was a biologist, and told me that the way the healing of wounds is implemented is that cells multiply when there aren't other cells next to them. If there is a hole, then the cells will divide to fill in the gap, with the signal to stop occuring when the dividing cells finally close up the hole. The problem is that that signal to stop gets screwed up somehow sometimes - either it's not produced, or its ignored. There is only a small probability of this happening, but if you are repeatedly wounded, then the probability increases. Some people have a habit of biting the insides of their cheeks. I understand that doing so can cause cancers where you bite.
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I can see Toonol's worries here. The ovaries contain single cells that ought to grow into a whole being when fertilized. Sometimes, these go wrong, and you get something else. These other things are usually hair, teeth, or occasionally eyes (eeww!). However, you don't get a fingernail or a kidney or a brain. This is probably because hair, teeth and eyes can be 'seeded' from a single cell, where other organs probably develop from a coordinated modification of a set of cells.
This is not to say that there isn't come magic genetic 'sudo' command that allows you to ask for a left kidney, medium size, but we haven't seen any sign of it yet.