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Dead bodies may provide plentiful source of stem cells
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After death, your stem cells could still save lives
here too, through the choice of which digit to bet on, either as neural fluctuations, as with the coin flip, or as other uncertainty from a random number generator. Page thinks that is a claim too far, though. “One could conceptually imagine a case where quantum mechanics is not relevant for choosing which digit we are talking about.” Our understanding of the multiverse is far from settled, says Srednicki. “The multiverse is an unruly beast and we would like to tame it, but I don’t think anyone has drawn blood yet.” ■
STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY
work, we need a replacement, but we can’t deduce one from concepts we already have.” Alexander Vilenkin of Tufts University in Medford, Massachusetts, doubts there is a replacement. “If you know the wave function of the universe, you still have to decide which copy is you,” he says. “I think there is no way to do it.” As a result, he is sanguine about continuing with conventional probability in multiverse calculations. Albrecht admits that a single example of a system that can be described in purely conventional terms would lend support to this argument, but he says he hasn’t encountered one yet. “I’ve been challenging people for a couple of years now,” he says. One that comes close is placing a bet on the value of the millionth digit of pi. It is easy to calculate
A PERSON’S organs can be used after they die, and now their stem cells might be harvested too. Huge numbers of stem cells can be mined from bone marrow up to five days after death and used in a variety of life-saving treatments. Human bone marrow contains mesenchymal stem cells (MSCs), which can develop into a variety of cell types, including bone, cartilage and fat. They can be transplanted from one person to another, with the type of cell they form depending on where in the body they are injected. Cells injected into the heart, for example, can become healthy cardiac tissue, a useful therapy for people with chronic heart conditions. Unlike other tissue transplants, MSCs tend not to be rejected by the recipient’s immune system. In fact, MSCs appear to pacify immune cells. This has made MSC treatments invaluable for children vulnerable to graft-versus-host disease, in which transplants aimed at treating –The penny has dropped– diseases such as leukaemia attack the child instead. Such therapies require huge this exactly – it is 5, as it happens – numbers of cells, though, and it can be but if neither party knows that in advance, it becomes a probability difficult to obtain a sufficient amount from a living donor. Could cadavers be problem, and conventional the answer? After death, most cells in probability says there is a 1 in 10 the body shut down within a couple chance of winning the bet. of days. But since MSCs live in an Albrecht and Phillips say environment that is normally very quantum effects come into play
low in oxygen, Gianluca D’Ippolito and his colleagues at the University of Miami, Florida, wondered if they might survive longer. To investigate, D’Ippolito’s team kept the finger bones of two cadavers for five days. The researchers then extracted MSCs from the marrow of each bone and let them grow in a dish. After five weeks they were able to transform the stem cells into cartilage, cells that form bone, and fat cells. D’Ippolito presented the results at the World Stem Cell Summit in West Palm Beach, Florida, last month. The team are now trying to get the cells to become nerve and intestinal cells, too. While only limited amounts of bone marrow can be taken from a living donor, a cadaver represents a plentiful source of cells, D’Ippolito says. “From one donor, you could take the whole spine, for example. You are going to end up with billions of cells.” Paolo Macchiarini, who researches regenerative medicine at the Karolinska Institute in Stockholm, Sweden, describes the work as an excellent advance but says that the cells may not be as healthy as they seem. Their DNA may be affected by the death of surrounding tissue and exposure to low temperatures. “We need to make sure the cells are safe,” he says. Corneal stem cells taken from the eyes shortly after death have already been used to treat blindness in people whose condition results from injury and scarring, but Chris Mason at University College London sees a potential hurdle in using MSCs in such therapy. “The work is novel and intriguing… but it would be better to use a living donor,” he says. That’s partly because medical regulators oppose treating individuals with stem cells from more than one source. “You can always go back and get more stem cells from a living donor if you need them, but if you use a cadaver, you’ll eventually run out.” –Stem cells live on– Jessica Hamzelou ■ 5 January 2013 | NewScientist | 9
After death, your stem cells could still save lives
here too, through the choice of which digit to bet on, either as neural fluctuations, as with the coin flip, or as other uncertainty from a random number generator. Page thinks that is a claim too far, though. “One could conceptually imagine a case where quantum mechanics is not relevant for choosing which digit we are talking about.” Our understanding of the multiverse is far from settled, says Srednicki. “The multiverse is an unruly beast and we would like to tame it, but I don’t think anyone has drawn blood yet.” ■
STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY
work, we need a replacement, but we can’t deduce one from concepts we already have.” Alexander Vilenkin of Tufts University in Medford, Massachusetts, doubts there is a replacement. “If you know the wave function of the universe, you still have to decide which copy is you,” he says. “I think there is no way to do it.” As a result, he is sanguine about continuing with conventional probability in multiverse calculations. Albrecht admits that a single example of a system that can be described in purely conventional terms would lend support to this argument, but he says he hasn’t encountered one yet. “I’ve been challenging people for a couple of years now,” he says. One that comes close is placing a bet on the value of the millionth digit of pi. It is easy to calculate
A PERSON’S organs can be used after they die, and now their stem cells might be harvested too. Huge numbers of stem cells can be mined from bone marrow up to five days after death and used in a variety of life-saving treatments. Human bone marrow contains mesenchymal stem cells (MSCs), which can develop into a variety of cell types, including bone, cartilage and fat. They can be transplanted from one person to another, with the type of cell they form depending on where in the body they are injected. Cells injected into the heart, for example, can become healthy cardiac tissue, a useful therapy for people with chronic heart conditions. Unlike other tissue transplants, MSCs tend not to be rejected by the recipient’s immune system. In fact, MSCs appear to pacify immune cells. This has made MSC treatments invaluable for children vulnerable to graft-versus-host disease, in which transplants aimed at treating –The penny has dropped– diseases such as leukaemia attack the child instead. Such therapies require huge this exactly – it is 5, as it happens – numbers of cells, though, and it can be but if neither party knows that in advance, it becomes a probability difficult to obtain a sufficient amount from a living donor. Could cadavers be problem, and conventional the answer? After death, most cells in probability says there is a 1 in 10 the body shut down within a couple chance of winning the bet. of days. But since MSCs live in an Albrecht and Phillips say environment that is normally very quantum effects come into play
low in oxygen, Gianluca D’Ippolito and his colleagues at the University of Miami, Florida, wondered if they might survive longer. To investigate, D’Ippolito’s team kept the finger bones of two cadavers for five days. The researchers then extracted MSCs from the marrow of each bone and let them grow in a dish. After five weeks they were able to transform the stem cells into cartilage, cells that form bone, and fat cells. D’Ippolito presented the results at the World Stem Cell Summit in West Palm Beach, Florida, last month. The team are now trying to get the cells to become nerve and intestinal cells, too. While only limited amounts of bone marrow can be taken from a living donor, a cadaver represents a plentiful source of cells, D’Ippolito says. “From one donor, you could take the whole spine, for example. You are going to end up with billions of cells.” Paolo Macchiarini, who researches regenerative medicine at the Karolinska Institute in Stockholm, Sweden, describes the work as an excellent advance but says that the cells may not be as healthy as they seem. Their DNA may be affected by the death of surrounding tissue and exposure to low temperatures. “We need to make sure the cells are safe,” he says. Corneal stem cells taken from the eyes shortly after death have already been used to treat blindness in people whose condition results from injury and scarring, but Chris Mason at University College London sees a potential hurdle in using MSCs in such therapy. “The work is novel and intriguing… but it would be better to use a living donor,” he says. That’s partly because medical regulators oppose treating individuals with stem cells from more than one source. “You can always go back and get more stem cells from a living donor if you need them, but if you use a cadaver, you’ll eventually run out.” –Stem cells live on– Jessica Hamzelou ■ 5 January 2013 | NewScientist | 9