3 ms·

I haven't studied medicin, but have a smattering of chemistry so I follow the subject a bit. The article miss the probably most interesting aspect. In fifteen

by berntb 15y ago

I haven't studied medicin, but have a smattering of chemistry so I follow the subject a bit. The article miss the probably most interesting aspect. In fifteen years, there will almost certainly be organs grown from stem cells, which allows transplants without immunity problems. What would happen to the first example in the article when the hearth and kidneys are replaced? When growth factors and (more or less) young stem cells start repairing the brain damage and the Parkinsons? It might take twenty years. It will still be in time for most people on HN when you grow old. Anyway, it is probably only of academic interest to me (old health problems will probably get me).

polyfractal 15y ago
Edit: I don't think everyone should be downvoting the parent. It's a logical statement from someone outside the field - you see "organs grown in XYZ lab!" all the time in the press. As a biologist, I can tell you that home-grown organs are waaay more than 15 years away. Currently, we can grow skin pretty well. Mostly because skin likes to grow and is very simple in structure. We are making progress on growing liver tissue, again because liver cells are particularly robust and the liver is not a strongly organized tissue. It is (mostly) a big blog of heterogeneous cells that does not require complicated geometry and organization. Anything past those two are wishful thoughts. I'm not discounting the advances that we have made in growing organs. We've done some very cool work, but it is certainly a long way away. Once the basic science is established, it will still take a long time to get widespread medical approval. Re: "repairing" the brain makes growing an organ look trivial. The difference is like building a house vs repairing CERN's LHC.
- joering2 15y ago
  interesting. can you explain bit more why repairing brain would be that complicated (asked by someone that never touched biology [me]) side note: your Cloudera job post has cudazi tags visible.
  - polyfractal 15y ago
    Sure. With a lot of organs, the function is a relatively mundane process. The heart pumps. The liver filters. The skin grows and dies and grows some more. This simplifies things a bit. The challenge is to get all the right cells in the right places. Heart cells need to be arranged specifically so that the heart can pump. Wikipedia has a good animated gif of how the conduction wave flows through the heart [1]. Fortunately, this is a surmountable challenge. You can throw progenitor cells into a pre-built scaffold and they tend to organize like they should. This is because most organs in your body are built of relatively interchangeable parts. E.g. Most of your heart is the same kind of muscle cell. The brain is a bit different. First, the type of damage is very dependent on the disease state. Have we lost entire neurons? What regions are affected? Are our neurons de-mylenating? Second, your brain is unique to you. Sure, we both share stereotyped architecture: we both have a hippocampus, a cerebral cortex, a cerebellum, etc etc. The structure inside each region is pretty stereotyped too - we both have cortical bundles in our neocortex. But when you drill down to the cellular level, we are very, very different. Each neuron I possess in my brain has a unique (and dynamic) synaptic arbor that connects to thousands of other, unique neurons. If I suffer a stroke and a portion of my brain dies, you can't simply throw more neurons in to compensate. Effectively, neurons are not interchangeable parts like heart muscle cells. You need to coax those neurons to: A) live in relatively hostile environment B) synapse to appropriate neuronal populations C) weight those synapses correctly. [1]http://en.wikipedia.org/wiki/File:ECG_Principle_fast.gif http://en.wikipedia.org/wiki/File:ECG_Principle_fast.gif Side note: Thanks for the heads-up on the Cloudera post - I just migrated themes and servers last night :)
    - loup-vaillant 15y ago
      (I'm a programmer, I know little about biology) Another way to look at it is the information theoretic perspective: when organ X is damaged? what information do you need to grow it back? If X is anything but the brain (and maybe part of the spine), the information you need can almost always be picked from somewhere else (Stem cells plus standard human anatomy). We can't do that now, but in principle it should work. But if you lose part of your brain, then it's a tougher challenge, because your personal memories, skills and more are stored in it. The only way to recover that would be to use the redundancy your brain might feature. Otherwise, it's lost. Sometimes, you cannot recover a code from a burned piece of paper. Now, if your brain just suffers a terminal illness, but the information is still there, then healing you may be as difficult as copying your whole soul into a computer, synapse per synapse. (Or it may not: we do have way to slow down —not heal— Parkinson, for instance.)
- ricree 15y ago
  I seem to remember some promising experiments that grew replacement hearts on an existing extracellular matrix. While they were still a long way from being true replacements, they showed enough functionality to look like a promising direction. Did that not pan out, or are there other major hurdles that would prevent this from being viable within a couple decades?
- berntb 15y ago
  >>Anything past those two are wishful thoughts. hardly just skin and liver! It is easy to find information about e.g. therapies for horses' joints. This link is about humans, just a few years from patients. http://news.bbc.co.uk/2/hi/health/1809322.stm http://news.bbc.co.uk/2/hi/health/1809322.stm There are people walking around with bladders and (built with a scaffold) throats. There are grown muscle patches for hearts, etc. (I didn't mean to replace parts of the brain surgically of course, stem cells rebuild damaged areas after strokes.) (I assume you aren't claiming that Parkinson won't be cured in 20 years?) Do you have any references? What are the show stoppers to scale to more complex tissue? The field obviously moves fast. Muscles like the heart and "simple" organs like kidneys should probably be possible. Is blood supply not solvable? Edit: Sorry for coming back a few hours later. (I was downvoted a while? :-) )
- berntb 15y ago
  Here is a group working on muscle with 3D printers. As I wrote in previous comment, building simple organs (hardly eyes) seems to move quite fast. http://www.technologyreview.com/biomedicine/39687/?%3C http://www.technologyreview.com/biomedicine/39687/?%3C

by berntb 15y ago

polyfractal 15y ago

Edit: I don't think everyone should be downvoting the parent. It's a logical statement from someone outside the field - you see "organs grown in XYZ lab!" all the time in the press. As a biologist, I can tell you that home-grown organs are waaay more than 15 years away. Currently, we can grow skin pretty well. Mostly because skin likes to grow and is very simple in structure. We are making progress on growing liver tissue, again because liver cells are particularly robust and the liver is not a strongly organized tissue. It is (mostly) a big blog of heterogeneous cells that does not require complicated geometry and organization. Anything past those two are wishful thoughts. I'm not discounting the advances that we have made in growing organs. We've done some very cool work, but it is certainly a long way away. Once the basic science is established, it will still take a long time to get widespread medical approval. Re: "repairing" the brain makes growing an organ look trivial. The difference is like building a house vs repairing CERN's LHC.

joering2 15y ago
interesting. can you explain bit more why repairing brain would be that complicated (asked by someone that never touched biology [me]) side note: your Cloudera job post has cudazi tags visible.
- polyfractal 15y ago
  Sure. With a lot of organs, the function is a relatively mundane process. The heart pumps. The liver filters. The skin grows and dies and grows some more. This simplifies things a bit. The challenge is to get all the right cells in the right places. Heart cells need to be arranged specifically so that the heart can pump. Wikipedia has a good animated gif of how the conduction wave flows through the heart [1]. Fortunately, this is a surmountable challenge. You can throw progenitor cells into a pre-built scaffold and they tend to organize like they should. This is because most organs in your body are built of relatively interchangeable parts. E.g. Most of your heart is the same kind of muscle cell. The brain is a bit different. First, the type of damage is very dependent on the disease state. Have we lost entire neurons? What regions are affected? Are our neurons de-mylenating? Second, your brain is unique to you. Sure, we both share stereotyped architecture: we both have a hippocampus, a cerebral cortex, a cerebellum, etc etc. The structure inside each region is pretty stereotyped too - we both have cortical bundles in our neocortex. But when you drill down to the cellular level, we are very, very different. Each neuron I possess in my brain has a unique (and dynamic) synaptic arbor that connects to thousands of other, unique neurons. If I suffer a stroke and a portion of my brain dies, you can't simply throw more neurons in to compensate. Effectively, neurons are not interchangeable parts like heart muscle cells. You need to coax those neurons to: A) live in relatively hostile environment B) synapse to appropriate neuronal populations C) weight those synapses correctly. [1]http://en.wikipedia.org/wiki/File:ECG_Principle_fast.gif http://en.wikipedia.org/wiki/File:ECG_Principle_fast.gif Side note: Thanks for the heads-up on the Cloudera post - I just migrated themes and servers last night :)
  - loup-vaillant 15y ago
    (I'm a programmer, I know little about biology) Another way to look at it is the information theoretic perspective: when organ X is damaged? what information do you need to grow it back? If X is anything but the brain (and maybe part of the spine), the information you need can almost always be picked from somewhere else (Stem cells plus standard human anatomy). We can't do that now, but in principle it should work. But if you lose part of your brain, then it's a tougher challenge, because your personal memories, skills and more are stored in it. The only way to recover that would be to use the redundancy your brain might feature. Otherwise, it's lost. Sometimes, you cannot recover a code from a burned piece of paper. Now, if your brain just suffers a terminal illness, but the information is still there, then healing you may be as difficult as copying your whole soul into a computer, synapse per synapse. (Or it may not: we do have way to slow down —not heal— Parkinson, for instance.)
ricree 15y ago
I seem to remember some promising experiments that grew replacement hearts on an existing extracellular matrix. While they were still a long way from being true replacements, they showed enough functionality to look like a promising direction. Did that not pan out, or are there other major hurdles that would prevent this from being viable within a couple decades?
berntb 15y ago
>>Anything past those two are wishful thoughts. hardly just skin and liver! It is easy to find information about e.g. therapies for horses' joints. This link is about humans, just a few years from patients. http://news.bbc.co.uk/2/hi/health/1809322.stm http://news.bbc.co.uk/2/hi/health/1809322.stm There are people walking around with bladders and (built with a scaffold) throats. There are grown muscle patches for hearts, etc. (I didn't mean to replace parts of the brain surgically of course, stem cells rebuild damaged areas after strokes.) (I assume you aren't claiming that Parkinson won't be cured in 20 years?) Do you have any references? What are the show stoppers to scale to more complex tissue? The field obviously moves fast. Muscles like the heart and "simple" organs like kidneys should probably be possible. Is blood supply not solvable? Edit: Sorry for coming back a few hours later. (I was downvoted a while? :-) )
berntb 15y ago
Here is a group working on muscle with 3D printers. As I wrote in previous comment, building simple organs (hardly eyes) seems to move quite fast. http://www.technologyreview.com/biomedicine/39687/?%3C http://www.technologyreview.com/biomedicine/39687/?%3C