NEWS&ANALYSIS heart, lung, liver, or kidney transplant,” says Neil Huband, a spokesman for the program. In many countries, women without a uterus could opt to have a surrogate mother bear their child—although not in Sweden, where surrogacy is banned. The Swedish trial showed that the risks to the donor are real. To ensure a good blood flow and reduce the risk of thrombosis, the team opted to transplant not just the womb but also its long veins and arteries, which were attached directly to the large blood vessels deep in the recipient’s pelvis. This greatly complicated the donor operations, however;
they took 10 to 13 hours. In one “extremely difficult” case, the paper says, a 58-year-old donor developed a fistula between her urethra and her vagina, a condition which can lead to incontinence. She had to have a second round of surgery after 4.5 months. Problems arose in two recipients as well: One had to have her transplant removed because of a uterine infection, the other after thrombosis. Catsanos, the ethicist, calls the complications “disconcerting.” “It just amplifies the problems that already exist,” she says. But Brännström believes the risks for the donor are manageable. “I would say
that for a novel procedure this complicated, there were few complications,” he says. And the operation time will come down to 5 or 6 hours once surgeons become more experienced, he says. The Swedish team is now carrying out standard IVF treatment on the seven women. Brännström declined to discuss whether there have been any pregnancies so far, saying the publicity would put unnecessary pressure on the patients. –RICHARD ORANGE Richard Orange is a freelance journalist in Gothenburg, Sweden.
Downloaded from www.sciencemag.org on March 28, 2014
P L A N E TA R Y S C I E N C E
CREDIT: NASA/JPL-CALTECH
Search for Martian Life Clears Another Hurdle THE WOODLANDS, TEXAS—Members of the Curiosity Mars rover’s science team have announced a milestone in their search for signs of ancient life on Mars. After carefully checking recent results, the researchers said last week at the annual Lunar and Planetary Science Conference here, they are now reasonably confident that contaminants brought from Earth cannot entirely explain certain carbon compounds Curiosity spotted in martian rock. If so, these simple organic compounds— chlorine-carrying methane and the like— either came with the tons of never-alive cosmic debris that sifts onto every planetary body or are something far more exciting: remains of martian life from eons ago, when a habitable lake and a rushing stream graced the rover’s now-dry landing site. To reach that conclusion, scientists had to clear some daunting hurdles. First, they had to account for the effects of perchlorate, a corrosive, oxidizing compound that is pervasive on Mars and, when heated, can chew up any complex organic matter into little bits (Science, 12 April 2013, p. 138). They also had to reckon with known sources of contamination in Curiosity’s Sample Analysis at Mars (SAM) instrument package (Science, 31 August 2012, p. 1032). A chemical reagent brought along for future analyses of organics had somehow leaked into the system, and gases driven off soil and rock samples were reacting with a polymer used to prepare compounds for identification by mass spectrometry. As a result, the rover was making its own organics, including the small chlorinated methanes and the sizable compound chlorobenzene. To sort out which of the device’s detections are truly martian, the team instructed SAM
to run blanks: analyses made with empty sample vials. They flushed both blanks and real samples with inert gas and warmed them to drive off the contaminating reagent. On Earth, they ran samples containing known organics through a SAM apparatus under Mars-like conditions. And on the rover, they tried experiments such as analyzing samples three times as big as normal to see whether the yield of particular organics would triple as well.
is martian as well. Or as one of his slides pointedly put it: “The detection of reduced organic compounds in Martian near-surface samples is a significant step.” Some experts outside the 400-strong Curiosity team are more guarded. “The case for a martian source of carbon builds,” responded meteoriticist Mark Sephton of Imperial College London by e-mail. He was not at the meeting but read the four pages of abstracts describing the results.
Pay dirt. The Curiosity rover first drilled into martian rock at this spot on its way to 5-kilometer-high Mount Sharp. More drilling and much checking have yielded traces of martian organic matter.
At the meeting, Caroline Freissinet and Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a score of fellow SAM team members reported that the latest results are persuasive. The new findings offer “compelling” evidence that some of the carbon-containing compounds SAM recently detected such as chlorinated methane, ethane, and propane came from organic matter in ancient martian rock, not from earthly contamination, Freissinet said. And Glavin said that other results are “a good indication” that some of the chlorobenzene
www.sciencemag.org
SCIENCE
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Published by AAAS
The case could build further if Curiosity strikes a richer vein of organic matter in future samples. Or SAM team members could try a more sophisticated technique to separate out the organic compounds in rock before the pervasive oxidizing agent chews them up. The next opportunity to drill a new sample will come within a few months when Curiosity is likely to pause on its way to its ultimate target, Mount Sharp. –RICHARD A. KERR With additional reporting by Emily Lakdawalla, a freelance journalist in Los Angeles, California.
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they took 10 to 13 hours. In one “extremely difficult” case, the paper says, a 58-year-old donor developed a fistula between her urethra and her vagina, a condition which can lead to incontinence. She had to have a second round of surgery after 4.5 months. Problems arose in two recipients as well: One had to have her transplant removed because of a uterine infection, the other after thrombosis. Catsanos, the ethicist, calls the complications “disconcerting.” “It just amplifies the problems that already exist,” she says. But Brännström believes the risks for the donor are manageable. “I would say
that for a novel procedure this complicated, there were few complications,” he says. And the operation time will come down to 5 or 6 hours once surgeons become more experienced, he says. The Swedish team is now carrying out standard IVF treatment on the seven women. Brännström declined to discuss whether there have been any pregnancies so far, saying the publicity would put unnecessary pressure on the patients. –RICHARD ORANGE Richard Orange is a freelance journalist in Gothenburg, Sweden.
Downloaded from www.sciencemag.org on March 28, 2014
P L A N E TA R Y S C I E N C E
CREDIT: NASA/JPL-CALTECH
Search for Martian Life Clears Another Hurdle THE WOODLANDS, TEXAS—Members of the Curiosity Mars rover’s science team have announced a milestone in their search for signs of ancient life on Mars. After carefully checking recent results, the researchers said last week at the annual Lunar and Planetary Science Conference here, they are now reasonably confident that contaminants brought from Earth cannot entirely explain certain carbon compounds Curiosity spotted in martian rock. If so, these simple organic compounds— chlorine-carrying methane and the like— either came with the tons of never-alive cosmic debris that sifts onto every planetary body or are something far more exciting: remains of martian life from eons ago, when a habitable lake and a rushing stream graced the rover’s now-dry landing site. To reach that conclusion, scientists had to clear some daunting hurdles. First, they had to account for the effects of perchlorate, a corrosive, oxidizing compound that is pervasive on Mars and, when heated, can chew up any complex organic matter into little bits (Science, 12 April 2013, p. 138). They also had to reckon with known sources of contamination in Curiosity’s Sample Analysis at Mars (SAM) instrument package (Science, 31 August 2012, p. 1032). A chemical reagent brought along for future analyses of organics had somehow leaked into the system, and gases driven off soil and rock samples were reacting with a polymer used to prepare compounds for identification by mass spectrometry. As a result, the rover was making its own organics, including the small chlorinated methanes and the sizable compound chlorobenzene. To sort out which of the device’s detections are truly martian, the team instructed SAM
to run blanks: analyses made with empty sample vials. They flushed both blanks and real samples with inert gas and warmed them to drive off the contaminating reagent. On Earth, they ran samples containing known organics through a SAM apparatus under Mars-like conditions. And on the rover, they tried experiments such as analyzing samples three times as big as normal to see whether the yield of particular organics would triple as well.
is martian as well. Or as one of his slides pointedly put it: “The detection of reduced organic compounds in Martian near-surface samples is a significant step.” Some experts outside the 400-strong Curiosity team are more guarded. “The case for a martian source of carbon builds,” responded meteoriticist Mark Sephton of Imperial College London by e-mail. He was not at the meeting but read the four pages of abstracts describing the results.
Pay dirt. The Curiosity rover first drilled into martian rock at this spot on its way to 5-kilometer-high Mount Sharp. More drilling and much checking have yielded traces of martian organic matter.
At the meeting, Caroline Freissinet and Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a score of fellow SAM team members reported that the latest results are persuasive. The new findings offer “compelling” evidence that some of the carbon-containing compounds SAM recently detected such as chlorinated methane, ethane, and propane came from organic matter in ancient martian rock, not from earthly contamination, Freissinet said. And Glavin said that other results are “a good indication” that some of the chlorobenzene
www.sciencemag.org
SCIENCE
VOL 343
Published by AAAS
The case could build further if Curiosity strikes a richer vein of organic matter in future samples. Or SAM team members could try a more sophisticated technique to separate out the organic compounds in rock before the pervasive oxidizing agent chews them up. The next opportunity to drill a new sample will come within a few months when Curiosity is likely to pause on its way to its ultimate target, Mount Sharp. –RICHARD A. KERR With additional reporting by Emily Lakdawalla, a freelance journalist in Los Angeles, California.
28 MARCH 2014
1419
