If this had been done with embryonic stem cells, it would be on the front page of the New York Times, but I doubt the "Gray Lady" will even report the story. But Secondhand Smoke will: Adult stem cells have now proven successful in treating acute renal failure in rats. Not only that, but they do so without having to be first differentiated into a specific kind of cell. This could be very good news for suffering patients who want treatments brought quickly to the clinic. If differentiation isn't required for adult stem cells to provide medical benefit, the time from experimentation to actual clinical availability is likely to be considerably shortened.
This isn't something that embryonic stem cells appear to be able to do safely. One of the big problems with using ES cells in treatments is that their differentiation cannot be controlled, as a consequence of which, they often cause deadly tumors in animal studies.
Moreover, if differentiation is not needed to gain benefit from adult stem cells, it is an arrow through the heart of one of the biggest arguments made by promoters of embryonic stem cells. This argument is that ES cells exhibit "plasticity," that is, they have the ability, as the advocates often say, to "become any kind of cell in the body." This ubiquitous assertion omits an essential modifier, "in theory," and hence, is a scientifically inaccurate statement. Scientists think this will be possible--they just haven't been able to do it yet.
But I digress. This adult stem cell success is not the first experiment in which stem cells aided regeneration of tissues and organs when injected in their undifferentiated state. If this proves true over a wide swath of conditions--still to be demonstrated--the "plasticity" argument will be deflated.
According to the story, human trials may not be very far off. Let's hope it all works out. A lot of lives could be saved if our own bone marrow or other stem cells could treat acute kidney failure.