8 comments

  • csr861 hour ago
    Retina is a good example of this. Zebrafish can regrow damaged retina, but while mammals have the same stem cells (Muller glia), they dont repair the retina, but form scar tissue. There is a lot of research and I think they have managed to modify rat genome, so that their retina has showns some repair abilities. The problem is that it often causes tumors.<p>I have other retina permanently damaged, and suffer from double vision when looking small objects like text.
    • cortesoft1 hour ago
      Ah, I was wondering the evolutionary reason why those genes would have gone dormant.<p>Cancer is a sensible answer.
      • Sharlin47 minutes ago
        Yep, the unfortunate flipside of &quot;let&#x27;s use stem cells to rebuild stuff&quot; is always &quot;let&#x27;s use stem cells to give us cancer&quot;. Technology might help alleviate the cancer part compared to blind evolution, hopefully.
      • api9 minutes ago
        Some aging mechanisms like telomeres are also mechanisms to prevent cancer by limiting cell division.<p>It looks like one of the optimization edges walked by evolution is a conflict between longevity and the ability to repair and regenerate versus not getting cancer.<p>It’s easy to make human cell lines immortal, but that will kill you.
  • stevenwoo2 hours ago
    I’m surprised this does not mention humans can grow back the tips of their fingers (past the white part of cuticle) <a href="https:&#x2F;&#x2F;www.npr.org&#x2F;sections&#x2F;health-shots&#x2F;2013&#x2F;06&#x2F;10&#x2F;190385484&#x2F;chopped-how-amputated-fingertips-sometimes-grow-back" rel="nofollow">https:&#x2F;&#x2F;www.npr.org&#x2F;sections&#x2F;health-shots&#x2F;2013&#x2F;06&#x2F;10&#x2F;1903854...</a> Supposed to be only kids but I’ve chopped off a few mm by accident it came back as an adult or I can’t tell the difference.
    • roarcher1 hour ago
      Does your fingerprint look normal? When I was a kid I was goofing around with a pair of scissors and lopped off a good chunk of the pad of one finger. Thirty years later my fingerprint looks like a bunch of little dots at that location. The ridges never grew back properly.
      • VladVladikoff1 hour ago
        Same. Chopped off the tip of my thumb with an axe, it’s healed but very scarred and fingerprint is not normal.
    • adamors1 hour ago
      The exact same thing happened to me. I chopped off a good half a cm with an axe when splitting firewood about 5 years ago. After no less than 6 months there wasn’t any sign of the mutilation.
    • KellyCriterion2 hours ago
      2 years I ago I sliced maybe 1.5mm frommy thumb-tip; when taking off the bandage, I could clearly see the &quot;straight cut&quot; and that some material was missing.<p>Until today, it recovered completely
      • oniony2 hours ago
        What, last night?
      • delfinom1 hour ago
        Lol, I once sharpened my knives and went to cook. During the prep I said, &quot;wow I wonder how sharp the knife is&quot;, next thing you know, i cut about 1&#x2F;4&quot; of my finger tip off, right through the finger nail with zero resistance.<p>Besides the blood getting everywhere and needing superglue to stop it, it grew back completely fine.
        • catlikesshrimp1 hour ago
          &quot;During the prep I said, &quot;wow I wonder how sharp the knife&quot;&quot; Is there something missing in the story? (drugs, coercion, self harm ideas, anything) I have had my fair share of avoidable cuts, but none of them included looking at the edge before happening.
          • coryrc59 minutes ago
            The way you asked that question is wholly inappropriate for a public forum and also rude.
          • rpastuszak1 hour ago
            Irony deficiency
          • delfinom1 hour ago
            I didn&#x27;t look at the edge, I was just thinking of that idea while slicing some vegetables and coincidentally not paying attention at the same time.
    • stymaar1 hour ago
      Liver as well, but I have no idea if that&#x27;s the same underlying phenomenon.
  • david-gpu1 hour ago
    Not a single mention of the work on limb regeneration by Professor Michael Levin&#x27;s lab at Tufts?<p><a href="https:&#x2F;&#x2F;as.tufts.edu&#x2F;biology&#x2F;tufts-center-regenerative-and-developmental-biology&#x2F;people" rel="nofollow">https:&#x2F;&#x2F;as.tufts.edu&#x2F;biology&#x2F;tufts-center-regenerative-and-d...</a>
    • joedevon32 minutes ago
      Was waiting for your comment.
  • anticensor2 hours ago
    The trick is to make regeneration fast enough to heal the wound without making fast enough to cause cancer. Maybe even supported by provisional fibrosis.
    • ck_one1 hour ago
      Does that mean zebra fish with their ability to regrow the retina get cancer at a higher rate?
  • NotGMan1 hour ago
    In a study they figured out that organs seem to have an electrical potential range as a signature&#x2F;command for stem cells for which organ to build and where.<p>In a frog they were able to grow legit eyes in the gut just by artificialy inducing a certain voltage in that area. No need for any cell transplantations: the voltage really seems to be the only signal needed.<p>This might also be how it might be done in the future in humans: block scar tissue then induce voltage with the signature of the organ you wish to regrow.<p><a href="https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;22159581&#x2F;" rel="nofollow">https:&#x2F;&#x2F;pubmed.ncbi.nlm.nih.gov&#x2F;22159581&#x2F;</a>
  • ranger_danger2 hours ago
    Wasn&#x27;t this proven many years ago by a random guy who used a &quot;extra-cellular matrix&quot; of stem cells to regrow his severed finger, nail and all?<p>Found it: <a href="http:&#x2F;&#x2F;news.bbc.co.uk&#x2F;2&#x2F;hi&#x2F;7354458.stm" rel="nofollow">http:&#x2F;&#x2F;news.bbc.co.uk&#x2F;2&#x2F;hi&#x2F;7354458.stm</a>
    • lazyasciiart2 hours ago
      No, the end of your finger just can grow back. <a href="https:&#x2F;&#x2F;www.npr.org&#x2F;sections&#x2F;health-shots&#x2F;2013&#x2F;06&#x2F;10&#x2F;190385484&#x2F;chopped-how-amputated-fingertips-sometimes-grow-back" rel="nofollow">https:&#x2F;&#x2F;www.npr.org&#x2F;sections&#x2F;health-shots&#x2F;2013&#x2F;06&#x2F;10&#x2F;1903854...</a><p>Dude&#x27;s brother had him throw his product on the finger as it did so, definitely an astute marketing trick. <a href="https:&#x2F;&#x2F;www.theguardian.com&#x2F;science&#x2F;2008&#x2F;may&#x2F;01&#x2F;finger.claim" rel="nofollow">https:&#x2F;&#x2F;www.theguardian.com&#x2F;science&#x2F;2008&#x2F;may&#x2F;01&#x2F;finger.claim</a>
      • ranger_danger1 hour ago
        &quot;I don&#x27;t know how it works, so it must be fake news.&quot;<p>To be fair, the person being skeptical is just a surgeon, this is not a peer-reviewed study or anything actually scientific.<p>Your NPR link even shows that scientists realize there are still unknowns:<p>&gt; &quot;We think that nail stem cells may a have a special function to induce the whole regeneration process, including nerve attraction and growth of the bone,&quot; Ito say.<p>A cursory search seems to say that typical regrowth of a nail takes 4-6 months, but Spievak claimed his only took 4 weeks.<p>Can we say definitively that his &quot;pixie dust&quot; had nothing to do with it? I don&#x27;t think so. Can we say it <i>did</i> have something to do with it? Also unknown... but the answer right now IMO certainly isn&#x27;t a scientific &quot;no.&quot;
  • nryoo3 hours ago
    [dead]
  • buddhistdude1 hour ago
    Maybe that&#x27;s what Jesus used on the people that he healed
    • cheema331 hour ago
      &gt; Maybe that&#x27;s what Jesus used on the people that he healed<p>I think this is what all <i>healers</i> used. They were all way ahead of their time and clearly misunderstood.
    • petesergeant44 minutes ago
      In the whole Christian tradition, God&#x2F;Jesus generally does not go for organ or limb regeneration. Two counter examples are a healed ear in Luke (but this may well have been resumption of hearing? details are a little light), and then a single Spanish example in the 1600s.<p>For His own mysterious reasons, He simply doesn’t go in for that stuff, however much intercessionary prayer ends up in His inbox.
    • krapp1 hour ago
      Jesus, if he existed, didn&#x27;t actually heal anyone or perform any miracles. That&#x27;s mythology, not reality.
      • buddhistdude1 hour ago
        How do you know?
        • kennyadam59 minutes ago
          I think to claim that 2000 years ago there was one person who performed miracles and&#x2F;or healed people that nobody else could, with no actual evidence it was done and nobody else has been able to do it since, you need a better response to someone questioning it than “oh were you there? prove it didn’t happen.”
          • buddhistdude50 minutes ago
            No I don&#x27;t because I&#x27;m not claiming that I know that it happened
        • krapp1 hour ago
          Because I&#x27;m a grownup who knows the difference between reality and make-believe.
          • buddhistdude1 hour ago
            I take from this that you don&#x27;t, otherwise you would explain it
            • krapp1 hour ago
              You&#x27;re the one who believes magic is real, it&#x27;s up to you to explain it. Extraordinary claims and such.