Patterico's Pontifications

1/13/2008

Of Mice and Men

Filed under: Miscellaneous — DRJ @ 1:46 pm

[Guest post by DRJ]

Scientists from the University of Minnesota Center for Cardiovascular Repair have successfully coaxed the hearts of dead rats to beat again, providing hope that genetically engineered organs may someday be feasible:

“U.S. researchers say they have coaxed hearts from dead rats to beat again in the laboratory and said the discovery may one day lead to customized organ transplants for people.

“The hope would be we could generate an organ that matched your body,” said Doris Taylor of the University of Minnesota Center for Cardiovascular Repair. Her study, which appeared on Sunday in the journal Nature Medicine, offers a way to fulfill the promise of using stem cells — the body’s master cells — to grow tailor-made organs for transplant.

Taylor and colleagues used a process called decellularization to wash away existing cells from the hearts of dead rats while leaving the basic collagen structure intact.

They injected this gelatin-like scaffold with heart cells from newborn rats, fed them a nutrient-rich solution and left them in the lab to grow. Four days later, the hearts started to contract.

The researchers used a pacemaker to coordinate the contractions. They hooked up the hearts to a pump so they were being filled with fluids and added a bit of pressure to simulate blood pressure. Eight days later, the hearts started to pump.

“I have got to tell you, that was the home run,” Taylor said in a telephone interview.”

If that doesn’t get your heart beating, you should have watched the Chargers 28-24 victory over the Colts – without LaDainian Tomlinson and Philip Rivers, both of whom left early with knee injuries. Next up for the Chargers: The Patriots.

Are the Patriots living a charmed life or what?

— DRJ

6 Responses to “Of Mice and Men”

  1. Interesting and hopeful post, but I have been burned again and again with these kinds of reports—particularly when stem cells are involved (the stem cell debate is much more political than scientific, I fear). I’ll be interested in reading the actual journal article (attention Dr. K.!) and see what is being left out. Note the first paragraph: “U.S. researchers say they have coaxed hearts from dead rats to beat again in the laboratory…”

    They just used a dead mouse’s heart to create a mold or scaffold on which living cells could grow and “fill it in.” The living cells were obtained from another source. The “filled in” heart tissue began to beat (which is indeed a very hopeful result). So “dead hearts” were not beating again. That sounds like of zombi-like.

    This seems like a minor point, but it is not, given all the people looking for medical miracles. Medicine is advancing quickly, but I am (for now) very dubious about this sort of thing. Remember John Edwards selling people on stem cells curing all kinds of neurological diseases in the next few years?

    A couple of years ago, a similar approach was used to create bladders, which are VERY simple compared to a heart. I haven’t read any follow ups to that work..even though it had been used in human patients..

    http://en.wikipedia.org/wiki/Artificial_bladder

    On the other hand, look at this article:

    http://news.scotsman.com/ViewArticle.aspx?articleid=2822957

    Here, the claim is for the creation of artificial livers. Not so. These are small bits of livers that can be used to test liver toxicity of various drugs (which is a good use). If bladders are simple, hearts are complicated, and livers incredibly complex. But in now way do the results mean that we will be transplanting these little livers into people with liver problems.

    The bladder business is in human patients. I pray it works well. The mouse hearts? Can’t tell much from the report. The liver article gives false hope.

    I applaud and respect medical science, but we must be VERY conservative in our “promises” to the public.

    Whoops. Another sermon. Apologies all around.

    Eric Blair (31f4be)

  2. Scientists from the University of Minnesota Center for Cardiovascular Repair have successfully coaxed the hearts of dead rats to beat again

    Maybe there’s hope for Harry Reid after all!

    daleyrocks (906622)

  3. How about if the Chargers just go and beat the Patriots on their field? Payback could be very sweet.

    Charlie (03643a)

  4. The Chargers have their work cut out for them but they are an explosive team.

    DRJ (517d26)

  5. The work on artificial organs has involved creating a scaffolding of some sort that allows the new cells to arrange themselves. The trouble with liver is the circulation, which is very complex. The heart is actually pretty simple except for the conduction system and the article suggests that the conduction system is not regenerated. If they can keep the acellular structure intact, this is really big news. Acellular arteries have been used for years as grafts. The host’s own cells grow into the graft.

    A recent report on liver bioengineering:
    Additionally, culturing hepatocytes on three dimensional matrices permits culture in a flow bioreactor system with increased function and survival of the cultured cells. Based on bioreactor technology, bioartificial liver devices (BAL) are developed for extracorporeal liver support. Although BALs improved clinical and metabolic conditions, increased patient survival rates have not been proven yet. For intra-corporeal liver replacement, a concept which combines Tissue Engineering using three-dimensional, highly porous matrices with cell transplantation could be useful. In such a concept, whole liver mass transplantation, long term engraftment and function as well as correction of a metabolic defect in animal models could be achieved with a principally reversible procedure. Future studies have to investigate, which environmental conditions and transplantation system would be most suitable for the development of artificial functional liver tissue including blood supply for a potential use in a clinical setting.

    The mouse heart study may be very important

    Mike K (86bddb)

  6. DRJ, yup, they are charmed and dominate this year, the eyes of the world are on pats this year.

    james conrad (7cd809)


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