News this Week

Science  24 Jun 2005:
Vol. 308, Issue 5730, pp. 1848
  1. EUROPEAN UNION

    Political Crisis Puts Europe's Research Ambitions in Doubt

    1. Martin Enserink

    The marathon summit that failed and plunged the European Union into disarray last week also dealt a severe blow to aspirations for European science policy, unveiled just 2 months ago by the European Commission—most notably to its plan to double the E.U.'s science budget. Disappointed researchers say the fiasco shows that politicians are only paying lip service to the so-called Lisbon strategy, which aims to revamp Europe's economy through research, innovation, and economic reforms.

    “What a nightmare,” says French biologist Frédéric Sgard, vice president of Euroscience, an organization of European researchers that has lobbied for major new investments in science. The failure could spell the end of the plan, hailed by many scientists, for a European Research Council (ERC) to fund basic research. The 2-day meeting in Brussels, aimed at hashing out an E.U. budget for 2007–13, ended in bitter acrimony primarily because the United Kingdom refused to pay more into the E.U.'s coffers if negotiations on the union's agricultural subsidies weren't reopened—a condition unacceptable to France, the subsidies' main beneficiary. The stalemate deepened a crisis opened 3 weeks ago by the French and Dutch “no” votes on the proposed European Constitution.

    In April, the European Commission had rolled out its proposal for Framework 7 (FP7), the most ambitious of the E.U.'s research programs yet. At €73 billion, the 7-year program would have more than doubled the E.U.'s annual expenditure on research and innovation. But disagreements about the broader budget clouded the plan's future from the start (Science, 15 April, p. 342). In an attempt to solve the looming crisis, Luxembourg, which currently holds the E.U. presidency, recently proposed growing the entire “competitiveness” budget—which includes research—at a much slower pace, which would result in €43 billion or less for FP7.

    No love lost.

    Britain's Tony Blair and France's Jacques Chirac disagreed bitterly at last week's summit meeting.

    CREDIT: THIERRY ROGE/REUTERS

    The Luxembourg compromise failed last week, but few countries protested the cuts that it would have made in research and innovation, Sgard says, making it very unlikely they will reserve more money for science in any future agreement. What's more, with Britain assuming the rotating presidency for 6 months on 1 July, any compromise on member contributions and farm subsidies seems unlikely. That will, in turn, hamstring the discussion about FP7 in the European Parliament, which has just started, says Giles Chichester, chair of the Committee on Industry, Research, and Energy: “It would be extremely difficult if we don't know how much money we're talking about. We're in uncharted territory here.”

    The European Commission doesn't have a plan B, says a spokesperson for Research Commissioner Janez Potocnik. Until an agreement is reached on a new budget, the commission will continue preparing for FP7 based on the original proposal, she says. Member states' unwillingness to pay for the ambitious science policy they say they support has been “a huge disappointment” for Potocnik, who had tried hard to rally leaders behind FP7, according to a source close to the commissioner.

    Potocnik's predecessor Philippe Busquin, the architect of the commission's current science policy, is equally dismayed. Busquin, now a member of the European Parliament, calls the Luxembourg plan “unacceptable”—all the more so because it would leave agricultural subsidies almost intact. “That's a budget of the past instead of the future,” Busquin says. “This way, Europe will stagnate.”

    Experts can only speculate about what might be sacrificed in a science budget that falls far short of the commission's €73 billion proposal. One “prime target” would be the European Research Council, a new body to fund basic, investigator-driven research in a Europe-wide competition, Chichester predicts. “It's always easier to cut something if you haven't started it yet,” he says. But doing so would risk demoralizing and alienating the scientific community, which fought hard for the ERC; even major cuts in its proposed €1.7 billion annual budget would rob the council of its credibility, says Danish mathematician Mogens Flensted-Jensen, vice chair of the expert group that proposed the ERC in 2003.

    Still, Helga Nowotny, chair of the European Research Advisory Board, does see some hope. The crisis will force politicians to rethink what European unification is all about; research, innovation, and education may well benefit if scientists keep pressing their case. What's more, she notes that the United Kingdom is a strong proponent of shifting E.U. funds from farms to labs. Even if the British cannot foster a new agreement when they chair the union during their presidency, “they will certainly put research back on the map,” Nowotny says.

  2. CONDENSED MATTER PHYSICS

    Tiny Whirlpools Prove Atoms Flow Freely

    1. Adrian Cho

    Most researchers would rather not poke holes in their own experiments, but a team of physicists is happy to have done just that. Stirring a cloud of ultracold atoms, the physicists produced an array of tiny whirlpools that pierced the cloud and proved that the atoms in it had formed a “superfluid,” a strange quantum-mechanical soup that flows without any resistance and refuses to rotate. The observation confirms that atoms can join in pairs and behave much like the free-flowing electrons in a superconductor, an effect that physicists have been racing to witness (Science, 8 August 2003, p. 750).

    “It's a fantastic experiment, really heroic,” says Deborah Jin, a physicist at JILA, a laboratory run by the National Institute of Standards and Technology and the University of Colorado, Boulder. Last year, Jin and her team showed that atoms in a gas could pair like the electrons in a superconductor (Science, 6 February 2004, p. 741), but experimenters had not proved that the paired atoms actually flowed without resistance. The new results provide “conclusive evidence for superfluidity,” Jin says.

    To generate the vortices, Martin Zwierlein, Wolfgang Ketterle, and colleagues at the Massachusetts Institute of Technology in Cambridge first used laser beams and magnetic fields to chill atoms of the isotope lithium-6 to within billionths of a degree of absolute zero. The atoms hovered in a vacuum chamber, trapped in a laser beam, and the researchers applied a magnetic field to make them interact. Tuning the strength of the field, the physicists coaxed the atoms to pair to form a “Fermi condensate.” The subtle pairing occurs even though the atoms cannot bind to form molecules.

    Smoking gun.

    Array of vortices proves that paired atoms form a superfluid.

    CREDIT: ANDRE SCHIROTZEK/MIT

    The researchers then tried to rotate the cloud by tickling it with another laser, much as one might set a golf ball spinning by brushing it with a feather, as they report this week in Nature. Had the lithium-6 been an ordinary fluid, the cloud would have rotated as a whole, just as water will rotate along with a slowly turning drinking glass. A superfluid resists rotation, however, because it is essentially a quantum wave that can possess only quantized amounts of rotation. Turn its container fast enough, and a superfluid admits one quantum of rotation in the form of a tiny whirlpool, or “vortex.” Turn faster still, and the vortices proliferate and form a triangular array. That is what Zwierlein and Ketterle observed in the cloud of atoms, although not without a lot of work. “It was bloody difficult,” Ketterle says. “We were actually close to giving up.”

    A Fermi condensate is a cousin of a Bose-Einstein condensate, a superfluid that forms when, instead of pairing, particles pile into a single quantum wave. By changing the magnetic field, physicists can now transform a Fermi condensate of atoms into a Bose-Einstein condensate of loosely bound molecules and probe the connection between the two superfluids, says Henk Stoof, a theorist at Utrecht University in the Netherlands: “How you go from one limit to the other is very important.” The tunable superfluid could even mimic more exotic superfluids, such as the paired-up neutrons coursing through the hearts of neutron stars.

  3. INFECTIOUS DISEASES

    Lapses Worry Bird Flu Experts

    1. Dennis Normile,
    2. Martin Enserink*
    1. With reporting by Gong Yidong of China Features in Beijing.

    Global health experts trying to stave off a deadly pandemic of avian flu are alarmed by recent actions they see as counterproductive and even dangerous. Vietnam has been slow to report 10 new human cases, and farmers in China have reportedly been giving an antiviral drug to chickens that may have made the virus resistant to one of the few drugs available to fight human flu. If confirmed, China's actions would be “very, very dangerous,” says Ilaria Capua of the Istituto Zooprofilattico Sperimentale della Venezie in Legnaro, Italy.

    Vietnam has found another possible case of human-to-human transmission of the H5N1 virus among a total of 10 new cases it reported in a 1-week period—6 weeks or more after they were originally detected. The Ministry of Health officially notified the World Health Organization (WHO) of three new human H5N1 cases on 8 June, but the most recent of those had been detected on 26 April. On 14 June, Vietnam reported three more human cases that had turned up during the last 2 weeks of May. And on 17 June, the ministry reported four additional cases that had emerged between 1 and 17 June.

    Peter Horby, an epidemiologist in WHO's Hanoi office, says Vietnamese officials have quickly asked for help when there were obvious changes in the virus's behavior, as when numerous mild cases of the disease emerged this spring. But he says it has been frustrating that these same officials have been less forthcoming in reporting the details of what they apparently see as more routine cases.

    Some bird flu experts are equally alarmed by China's veterinary use of the human antiviral drug amantadine, as reported in the 18 June Washington Post. According to the article, drugmakers and other sources in China admitted that the drug has been sold cheaply to farmers and given to poultry both as a treatment and a prophylactic since the late 1990s.

    Drug habit.

    Chinese farmers routinely administered an antiviral drug to poultry, according to a news report.

    CREDIT: GREG BAKER/AP PHOTO

    Most of the H5N1 strains isolated in the current outbreak in Asia are resistant to amantadine, but establishing a firm link with China's use of the drug would require extensive data on where, when, and how much of the drug was used, notes Klaus Stöhr, WHO's global influenza coordinator. K. Y. Yuen, a virologist at the University of Hong Kong, says the misuse of antivirals, such as amantadine, does raise the risk of fostering resistance. But he says the genetic mutation associated with amantadine resistance has been reported in viruses not exposed to the drug, which suggests that other factors might be at work as well.

    Still, given the threat of a pandemic and the dearth of flu drugs—the only alternative to amantadine and a cousin is oseltamivir, or Tamiflu, which is more expensive and harder to produce—antivirals should probably not be used for animal flu infection at all, Stöhr says. They aren't licensed for use in poultry and would do little to contain the virus anyway if not accompanied by strict biosecurity measures, adds Capua.

    Xu Shixing, a Chinese Ministry of Agriculture official, says the ministry never approved the use of amantadine for poultry, as was claimed in the Post article.

    In yet another reminder of the virus's expanding geographical grip, Indonesia confirmed its first human case of H5N1 infection last week, the fourth country to do so.

  4. EUROPEAN PATENTS

    BRCA2 Claim Faces New Challenge

    1. Eliot Marshall

    A patent on the breast cancer gene BRCA2—a symbol of assertive U.S. biotechnology—faces a major challenge in the European Patent Office (EPO) in Munich, Germany, on 29 June. European clinical groups say the patent—licensed to Myriad Genetics of Salt Lake City, Utah—should be dismissed for legal and ethical reasons, including the fact that it is limited to diagnoses in Ashkenazi Jewish women. They hope this will stall the company's licensing push in Europe. The case is being watched as a test of how enforceable human gene patents will be in Europe.

    The controversial patent is a fragment of what was once a broad package of Myriad claims covering the genes BRCA1 and BRCA2. Although Myriad has exclusive rights to commercialize tests based on BRCA1 and BRCA2 in the United States, European clinics have resisted signing up for licenses. (The patents are owned by an array of groups, including the University of Utah Research Foundation.) European opponents have chipped away at Myriad's claims; their challenge based on sequence errors in a description of BRCA1, for example, helped scuttle that patent in Europe.

    In January, EPO approved a whittled-down version of the patent request on BRCA2, awarding the company “use of an isolated nucleic acid” on chromosome 13 “for diagnosing a predisposition to breast cancer in Ashkenazi Jewish women in vitro.” Continuing an anti-Myriad campaign already 5 years old, the Institut Curie in Paris and 19 other groups interested in gene testing have contested the new BRCA2 patent. (EPO is following standard practice in letting opponents argue against the patent after it has been awarded.) Many clinics have resisted the company's efforts to sell licenses because they seemed one-sided and based on weak claims, says geneticist Gert-Jan van Ommen of the Center of Human and Clinical Genetics at Leiden University Medical Center in the Netherlands. He says doctors object to paying Myriad for something they could do themselves. (A test now costs about $2800.) Myriad requires physicians to send patients' DNA samples to Utah, where the company keeps them. This does “not sit well,” says van Ommen, because Europeans had contributed a great deal to BRCA research.

    Opposed.

    Gert Matthijs says the BRCA2 patent is “not acceptable.”

    CREDIT: F. REINHOLD

    Last week the opponents recruited a new ally, the European Society for Human Genetics (ESHG) in Vienna, Austria. It has asked EPO to dismiss Myriad's BRCA2 patent because it explicitly claims a mutation in Ashkenazi Jewish women. The chair of ESHG's patenting and licensing committee, human geneticist Gert Matthijs of the University of Leuven, Belgium, says that seeking ownership of a mutation in an ethnic group “is not acceptable to most geneticists.”

    Dominique Stoppa-Lyonnet of the Institut Curie adds that it would compel a doctor to ask a woman about her ancestry before offering a consultation: “This is discrimination,” she believes. Besides, Stoppa-Lyonnet says, it is impractical: Many people of Ashkenazi descent don't know their ancestry.

    Myriad declined to comment because the matter is under legal review. However, a legal brief filed last year on the company's behalf by the firm Vossius & Partner in Munich argues that Myriad and collaborators spent “millions of dollars” to characterize BRCA2 and released the data freely for public use. Women across the globe have benefited, the brief says. It further argues that focusing on the Ashkenazi population makes testing for breast cancer risk more efficient and affordable.

    If the past is a guide, the EPO technical group will make its decision known quickly, says spokesperson Rainer Osterwalder. Either side can appeal for a final high-level EPO review.

  5. NUCLEAR SCIENCE

    RHIC Gets Nod Over JLab in Worst-Case DOE Scenario

    1. Charles Seife

    Earlier this year, the Department of Energy posed an agonizing question to a panel of nuclear physicists: If its budget doesn't get any better, which of two major DOE facilities should be shut down? Last week the panel delivered a verdict, showing a “slight preference” for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, New York, over the Thomas Jefferson National Accelerator Facility (JLab) in Newport News, Virginia. But adopting that choice, it warned DOE officials, would create a damaging rift within the nuclear science community.

    “It would be a dagger in the heart of international nuclear physics if this would happen,” says Tony Thomas, JLab's chief scientist. “It would create a deep chasm within the U.S. nuclear science community as well as an international chasm.” And the so-called winner is barely more joyful. “It would be really bad if we succumbed to the temptation to break into camps,” says Sam Aronson, associate director for high-energy and nuclear physics at Brookhaven. “We've always managed to get past difficult budget situations; we should not take the opportunity to fight with each other.”

    The trouble began in February after President George W. Bush proposed cutting nuclear physics at DOE by more than 8%, to $371 million. That drop would translate into a drastic reduction in run times for the two main nuclear physics facilities in the United States, RHIC at Brookhaven and CEBAF at JLab. And although Congress seems inclined to restore the cuts this year, DOE is expecting lean times for at least the rest of the decade. So in March, DOE asked its nuclear science advisory committee for help in dealing with such a scenario (Science, 29 April, p. 615).

    At risk.

    A continued tight budget could force DOE to shut its Thomas Jefferson National Accelerator Facility.

    CREDIT: PHOTO COURTESY OF JEFFERSON LAB

    The budget outlook gave the panel little flexibility, says Texas A&M physicist Robert Tribble, who chaired the subcommittee that made the call: “There's simply no way we can sustain JLab and RHIC operations at meaningful levels and still have a future.” The panel's “slight preference” for keeping RHIC alive was based on the fact that the instrument was still in the “discovery phase” after creating the quark-gluon plasma (Science, 22 April, p. 479).

    The potential for a schism is based on the fact that RHIC and CEBAF do very different types of nuclear-physics experiments. The former uses heavy ions to probe the conditions of nuclear matter in the early universe, whereas the latter uses electron beams to look at things such as the structure of the proton. Shutting down one would deprive a large chunk of the U.S. nuclear science community of a place to do research, dividing it into haves and have-nots. Picking one branch of research at the expense of another is divisive, says JLab's Thomas.

    The silver lining in the dark clouds gathering over nuclear science is a positive reaction from Congress so far this year. The House of Representatives has approved a 2006 spending bill that brings much of DOE's nuclear science budget close to current levels (Science, 27 May, p. 1241). Last week, a Senate panel added back even more, according to Dennis Kovar, DOE's associate director in charge of nuclear physics. At those funding levels—appropriately adjusted for inflation—Tribble says that DOE need not shut down a facility, although he warns that run times at the facilities would still suffer. And level funding won't help a major new experiment being planned. The Rare Isotope Accelerator, says the panel, “can proceed only with a significant influx of new money.”

    An anemic budget would have ramifications for the next generation of U.S. nuclear scientists, too, say physicists. “If you close either [RHIC or JLab] at this time,” says David Armstrong, a nuclear physicist at the College of William and Mary in Williamsburg, Virginia, “I in good conscience could not advise my students to pursue a career in nuclear science.”

  6. TAIWAN

    New University President Has Links to Paranormal Research

    1. Lei Du*
    1. Lei Du is a freelance writer in Shandong Province, China.

    JINAN, CHINA—The Taiwan government has chosen a devotee of research into paranormal phenomena to lead its premier university. Lee Si-chen, a semiconductor physicist at National Taiwan University (NTU), says he plans to end his current experiments of parapsychology once he takes office this week as NTU's 16th president. But faculty members are worried that those experiments, prominently displayed on Lee's CV and Web site, will undermine his efforts to make NTU, founded in 1928, a world-class institution.

    Lee, 52, previously dean of academic affairs at NTU, is well regarded for his work in solid state physics. “Professor Lee has certainly made several important contributions to semiconductor heterojunction device physics,” says James Harris, a semiconductor physicist at Stanford University in California. Trained at Stanford and a fellow of the Institute of Electrical and Electronics Engineers (IEEE), the leading international society for electrical and electronics engineers, Lee says he wants to make NTU one of the world's top 100 universities by wooing top-ranked scientists from around the globe and building new research and teaching facilities.

    In conjunction with his administrative and scientific labors, however, Lee has maintained an active interest in the paranormal. His research into Qigong (a Chinese practice combining meditation and breathing exercises) has favorably examined claims that so-called external Qi is capable of altering the nature of materials without any physical contact. He has also explored the phenomenon of “finger-reading,” which purports that school-aged children can be trained to visualize numbers, Chinese characters, and symbols written on paper that is wadded up and placed in their hands.

    That work bothers some of his colleagues. This spring, Yang Shin-nan, a physicist and delegate to the university's faculty senate, wrote an open letter expressing his fear that Lee's appointment could damage the university's reputation. NTU physicist Kao Yeong-Chuan, a longtime critic of Lee's paranormal research, says that he was “shocked that Professor Lee could get enough votes to become one of the two finalists.” Kao is willing to cut Lee some slack, but he says that “extra-ordinary claims must be backed up by extraordinary evidence.”

    Lee, who was appointed to a 4-year term, defends his line of investigation. “Everybody is welcome to reasonably challenge other people's research, but not to reject all unusual phenomena bluntly and arrogantly,” he says, adding that most of his studies on finger-reading were done to confirm the work of others. “Scientists should not be forbidden from exploring the unknown frontier.”

    Lee acknowledges, however, that findings have been inconsistent because human beings are “unsteady.” And although he would like to find more quantifiable metrics for studying such phenomena, he says he plans to terminate his experiments “for the sake of a peaceful campus.”

  7. BEHAVIOR

    Bird Alarm Calls Size Up Predators

    1. Greg Miller

    A great horned owl may look like a more fearsome predator than a puny pygmy owl, but for small, agile birds such as chickadees, the maneuverable pygmy owl is probably the more lethal threat. Now, on page 1934, researchers report that black-capped chickadees have a sophisticated system of alarm calls that conveys information about the size of potential predators. The calls appear to help the chickadees mount a coordinated defense that is calibrated to the predatory threat.

    Chickadees are social birds, and they gang up to “mob” predators and drive them away. “They dive-bomb the predator and make a lot of noise,” says study author Christopher Templeton, currently a Ph.D. student at the University of Washington, Seattle. While Templeton was working at the University of Montana, he and his adviser, behavioral ecologist Erick Greene, noticed that chickadees responded differently to the sight of different predators. “They really harassed some predators and just ignored others,” Templeton says.

    The researchers suspected that the chickadees' calls might organize their defense. The birds make two different alarm calls: a soft, high-pitched “seet” call and the louder namesake “chick-a-dee” call. A previous study found that the “seet” call indicates the presence of predators flying overhead. The “chick-a-dee” call is used in a variety of situations, from signaling the presence of stationary predators to identifying flockmates.

    On guard.

    Black-capped chickadees vary their alarm calls according to the size of the predator that has been spotted.

    CREDIT: C. N. TEMPLETON ET AL., SCIENCE

    The researchers recorded more than 5000 calls that birds made when various predators—including owls, hawks, and falcons from a local wildlife rehabilitation center—were placed in their woodsy outdoor enclosure. The recordings showed that, among other changes, the birds made more “chick-a-dee” calls and incorporated more “dee” syllables into each call when they saw a small raptor with a short wingspan. A 70-gram pygmy owl, for instance, might elicit four “dees” at the end of a call, whereas a 1.4-kilogram great horned owl might elicit only two. But not all small birds elicited more “dees”: A harmless quail elicited fewer than two “dees” per call, on average. The researchers hypothesize that more “dees” mean more danger.

    Next, the team played back recorded alarm calls through a hidden speaker and watched the chickadees' reaction. The birds mounted a more vigorous mobbing response when they heard a small predator alarm call. More birds got involved, and they approached closer to the speaker and kept up the mobbing for a longer period of time in response to a small predator alarm call than in response to a large predator call.

    “The work … shows us that even very common species that we may take for granted have evolved to have very elaborate and exacting systems of communication,” says James Hare, who studies ground squirrel alarm calls at the University of Manitoba in Winnipeg, Canada. Historically, researchers have thought alarm calls signaled information about either the type of predator or the degree of threat, says Daniel Blumstein of the University of California, Los Angeles, who studies marmot communication. The new study helps break down this “false dichotomy” by showing that chickadee calls tell of both, Blumstein says.

    It also adds to evidence that complex communication arises in the animal kingdom wherever there's a need. “These results should begin to redress the still-pervasive bias that sophisticated signaling can only arise amongst our primate kin,” says Christopher Evans, an animal behavior researcher at Macquaire University in Sydney, Australia.

  8. MARINE BIOLOGY

    Microbe May Push Photosynthesis Into Deep Water

    1. John Bohannon*
    1. John Bohannon is a science writer based in Berlin.

    The announcement this week of a bacterium that appears to derive energy from light despite living in the inky depths of an ocean threatens to overthrow the dogma that photosynthesis depends on the sun. The microbe may also offer clues about life on early Earth—or on other planets.

    Not everyone is convinced yet that the bacterium, discovered in 2003, is a natural resident of the deep sea. But if true, it could be a crucial piece of the puzzle of how photo-synthesis evolved. “The results break new ground and are indeed surprising,” says Bob Buchanan, a microbiologist at the University of California, Berkeley.

    Since their discovery in 1977, deep-sea hydrothermal vents have offered up a surprising menagerie, including 2-meter tubeworms and eyeless crabs, that thrives near the caustic 350°C effluent that burps out. In the late 1980s, Cindy Van Dover, a marine biologist at the College of William and Mary in Williamsburg, Virginia, found a vent-dwelling eyeless shrimp with a light-sensitive patch on its back. Because of the superheated water, vents glow with infrared radiation, but the shrimp's light-gathering pigments seemed geared for much higher frequencies of light.

    The explanation came in 1996 when a team led by Alan Chave, an oceanographer at the Woods Hole Oceanographic Institution (WHOI) in Massachusetts, proved that the water around the vents produces additional light. The extra glow is too weak to be detected by human eyes but has a frequency well into the visible spectrum. Researchers still don't agree on the mechanism by which the vents make this deep-sea illumination, but its discovery prompted another question: Does the phenomenon sustain any life?

    Bacteria 80 meters below the surface of the Black Sea eke out a living from similarly dim light. These so-called green sulfur bacteria have the most efficient photosynthesis known, sponging up every stray photon that penetrates the water column. So, in an effort partly funded by NASA's Astrobiology Institute, Van Dover teamed up with Thomas Beatty, a microbiologist at the University of British Columbia in Vancouver, Canada, Robert Blankenship, a biochemist at Arizona State University in Tempe, and others to see if similar bacteria were living off the vent light. In 2003, they descended 2.4 kilometers in the WHOI research submarine Alvin to retrieve samples from a pair of vents that lie along the volcanically active Pacific Ridge. Back on the ship, they added the samples to various nutrient media to see what might grow.

    A light at home.

    Deep-sea hydrothermal vents such as this one emit a mysterious glow (right) that may support photosynthetic bacteria.

    CREDITS: NOAA; (RIGHT) DELANEY, SMITH, VAN DOVER, CANN & FOSTER

    Defying the long odds, the team now describes the first example of an organism that seems to live off a light source other than the sun. The bacterium—known as GSB1 for the time being—requires light, sulfur, and CO2 to grow, the team reports online 28 June in the Proceedings of the National Academy of Sciences.

    To help culture the exotic bacterium, the team recruited Jörg Overmann, a microbiologist at the University of Munich, Germany, and discoverer of the Black Sea green sulfur bacteria. Although oxygen is thought to be toxic to all green sulfur bacteria, they unexpectedly found that GSB1 seems unbothered by it. The team proposes that the turbulent vent environment makes exposure to oxygen-rich water unavoidable for the bacterium, requiring it to adapt.

    The big question, according to Euan Nisbet, an Archaean geologist at Royal Holloway, University of London, U.K., is whether GSB1 is a missing link in the evolution of photosynthesis. “Of what use is half of photosynthesis?” he asks, referring to Darwin's puzzle of how evolutionary change through baby steps can create complex structures such as eyes that require multiple parts to function. Nisbet argues that a deep-sea microbe on the early anoxic Earth could have developed a primitive method for detecting the direction of the vents through infrared radiation, setting the stage for a later vent microbe to develop an inefficient version of photosynthesis as a supplement to its main food. Then, “one of these preadapted cells might have drifted into rather shallower water, well away from the hydrothermal vents, to survive by using sunlight just as modern Black Sea bacteria do. And after that, the sky's the limit,” Nisbet says.

    Another open question, says Buchanan, is whether GSB1 “is a long-term resident in the area surrounding the vent or whether it … spends much of its life elsewhere.” To quash such doubts, Beatty is planning a mission to isolate photosynthesizers from other vents.

    And what about the vent glow that may power such microbes? Its source remains “quite a speculative issue,” says Chave, with explanations ranging from chemical reactions in the vent effluent to sonoluminescence, the flash produced by imploding bubbles. Little work has been done on the phenomenon since its discovery, “both because defining the mechanism would require some difficult measurements … and because interest has waned,” says Chave. He hopes, however, that GSB1's discovery “will regalvanize the interest.”

  9. NEUROLOGY

    Autistic Brains Out of Synch?

    1. Ingrid Wickelgren

    Autism researchers are hot on the idea that autism results from abnormal communications between brain regions rather than a broken part of the brain

    Fourteen-year-old Benjamin Garbowit memorizes long lists of ingredients from food labels but has trouble understanding the point of even simple storybooks. The eighth grader from Short Hills, New Jersey, struggles through a conversation with a stranger, offering mostly one-word utterances. And he is confused by common gestures such as a pat on the head from his mother. “What does it mean?” he wants to know. “Is it love?”

    Benjamin has autism, a disorder that has long mystified parents, doctors, and scientists alike because of the diverse deficits, and occasional talents, that accompany it. Although the most glaring problems appear in social interactions, serious shortcomings also show up in reasoning tasks that require integrating different types of information. Autistic individuals may memorize facts easily but find complex concepts elusive.

    Researchers have struggled to find an overarching conception of the disorder. And in the past 3 years, they have accumulated tantalizing data suggesting that the problems in autism result from poor connections in the brain areas rather than from defects in a specific brain region. “A confluence of investigations point to a model of autism in which different brain regions are not talking to each other very well,” says Martha Herbert, a pediatric neurologist at Harvard Medical School in Boston. “This is a big paradigm shift, because people have been looking for the ‘brain address’ of the problem in autism.”

    Imaging experiments show a lack of cooperation between different brain areas, as well as abnormalities in the volume and distribution of the white matter that insulates neuronal signals. Other studies have found oddities in the organization, number, and size of neurons in certain brain regions that could give rise to connectivity problems. “It's the most exciting set of developments in the field to date,” comments Helen Tager-Flusberg, an autism researcher at Boston University School of Medicine.

    So far, the studies are largely suggestive, and skeptics say that connectivity theory does not get to the bottom of autism. Yet if the theory is correct, it suggests a new approach to molecular studies of the disease. For instance, researchers might look for genes that perturb the development of neural connections rather than genes that map to specific behaviors.

    Meanwhile, the work may enable more precise diagnosis of the disorder and a new way to test the efficacy of behavioral therapies or future drugs. “We're very close to finding a biological marker for autism using brain morphology and activation,” says Marcel Just, a cognitive neuroscientist at Carnegie Mellon University in Pittsburgh, Pennsylvania.

    Just the facts.

    Benjamin Garbowit, 14, knows the populations of many nations but struggles with the point of even simple stories.

    CREDIT: I. WICKELGREN

    Incommunicado

    The idea that faulty connections are at the core of autism is implied in a psychological theory proposed in the 1980s by developmental neuropsychologist Uta Frith of University College London. Frith noted that many autistic behaviors can be explained by a person obsessing with details and not integrating the particulars—whether they be words, facts, or visual details—to determine their broader meaning. Frith theorized that this tendency resulted from a lack of “top-down” mental processing. In the autistic brain, the theory went, the brain's frontal lobes—which play a central role in organizing, planning, directing attention, and guiding behavior—are not communicating properly with the more detail-oriented areas at the back of the brain.

    It was not until 2002 that Frith and her colleagues reported the first evidence for connectivity problems in autism. The researchers used positron emission tomography (PET) to scan the brains of 10 high-functioning autistic people and 10 controls while they tried to interpret the actions of two triangles on a computer screen. Under different conditions, the triangles moved randomly, interacted in straightforward ways such as dancing or chasing, or appeared to use mental strategies such as coaxing or tricking that autistic people typically do not recognize.

    As expected, the autistics did not describe the triangles' “intentions” as well as the normal subjects did, and they showed less activation in frontal brain regions involved in understanding the mental states of others. In addition, the scientists found that a visual region was not in synch with the mental-strategy network in the autistic brains, “as if there were some sort of bottleneck” in communications, Frith says.

    The latest data, from functional magnetic resonance imaging (fMRI), suggest that other parts of the brain are on nonspeaking terms as well. (Unlike PET, in which brain activation in each area is averaged over the course of a task, fMRI samples activation levels as often as once a second, enabling researchers to correlate the patterns of activation of different brain regions in time.) Just's lab at Carnegie Mellon, along with Nancy Minshew at the University of Pittsburgh School of Medicine, imaged the brains of 17 high-functioning autistic people and 17 controls as they answered questions about sentences. During this task, the activated brain areas showed far less synchrony in the autistic brains than in the brains of controls, they reported last August in Brain. “Some of the regions aren't linked up,” Minshew concludes.

    When the Pittsburgh teams used fMRI to test the ability to remember faces, they saw more varied connectivity abnormalities. In the autistic brains, links were weak between the front of the brain and the parietal lobe, between frontal regions and posterior perceptual brain areas, and between the face-processing brain region and other areas, the team reported in May at the International Meeting for Autism Research in Boston. They also described connectivity abnormalities in the brain network involved in the triangle task. “In study after study, we see a lower degree of synchronization in autistic brains,” Just says.

    Copycat smarts.

    The autistic brain (right) shows very little cooperation between brain areas when volunteers try to perform copycat finger movements. In controls (left), various brain regions, including the site of “mirror neurons” (arrow), work together during the exercise.

    CREDIT: MICHELE VILLALOBOS AND RALPH-AXEL MÜLLER/SAN DIEGO STATE UNIVERSITY

    This phenomenon could explain why autistic people have trouble carrying out certain actions. Ralph-Axel Müller, a cognitive neuroscientist at San Diego State University in California, and his colleagues recently scanned the brains of eight autistic males and eight controls while they watched an image of a hand on a computer screen. Each time a blue dot appeared on a finger, the subject tried to press a button with the same finger on his hand. As expected, the autistic males performed worse than controls. Their brains also showed a lack of synchrony between visual areas in the back of the brain and the inferior frontal cortex, which governs action planning and other functions. The results suggest that neural circuits for action plans may not be fully intact in autism, the researchers reported in the 15 April issue of Neuroimage.

    Part of the communication failure could be with so-called mirror neurons, which are heavily involved in imitating behaviors (Science, 13 May, p. 945). “It appears that the mirror-neuron system is impaired in autism because the long fiber tracts that connect to the mirror neurons are not as well organized,” Müller speculates. If so, that could explain the failure to imitate spoken words, for example, and might account for some of the language delays in autism.

    Faulty wiring

    Anatomical evidence is also bolstering the idea that disparate brain regions do not communicate efficiently in autism. For instance, Harvard's Herbert and her colleagues saw a large excess of white matter, which contains the nerve fibers insulated with myelin, in the brains of 14 autistic boys aged 5 to 11 compared to 14 normal boys in a structural MRI study reported in the April 2004 Annals of Neurology. Frontal areas showed the greatest excesses. The prefrontal lobe, the area devoted to the most complex processing, had 36% more white matter in the autistic brains compared to a 22% enlargement in the occipital lobe at the back of the brain, indicating that autistic brains sport irregularities in their white matter and particularly in the lobes that integrate different types of information.

    This surfeit of white matter was concentrated at the brain's surface, where short- and medium-range nerve fibers abound. Deeper, longer stretches of white matter, such as the nerve fibers that connect the two halves of the brain, were not enlarged in the autistic boys they examined. This suggests that individual brain regions—particularly the prefrontal cortex, devoted to complex processing—may have hyperefficient internal communications but don't interact well with distant brain regions, such as those in the other hemisphere.

    Herbert thinks the culprit may lie in the white matter itself, but it's too early to decide, she says, whether the abnormality relates to myelin production, neuronal fibers, or some other white-matter component. Herbert did not see any evidence of additional gray matter, which is dense with neurons, in the school-age autistic brains she studied.

    But others have found gray-matter abnormalities in autism, suggesting that the excess white matter might reflect a normal amount of wrapping on a larger number of nerve fibers. Autistic toddlers have on average 12% more gray matter in their cerebral cortex, according to a 2001 study by neuroscientist Eric Courchesne of the University of California, San Diego, and his colleagues. In unpublished postmortem studies, Courchesne's group has found a large excess of a special class of pyramidal neurons in the frontal cortex.

    Courchesne sees an imbalance in neuronal numbers between the front and back of the brain as a potential root cause of autism. If neurons that process sensory signals at the rear of the brain try to communicate with too many frontal neurons, their connections to that lobe may be too diffuse and lose their impact. That would greatly impair the ability of the frontal cortex to integrate sensory information, direct attention, plan, organize, and perform its other functions.

    Dancing triangles.

    A volunteer tries to interpret the motives of two interacting triangles in an MRI simulator. (left) Autistic people show lower synchrony between areas of a brain network (blue lines) during this task than do controls (red lines).

    CREDITS: MARCEL JUST/CARNEGIE MELLON UNIVERSITY

    The theory that autism results primarily from a gray-matter imbalance is also consistent with findings from the lab of neuroscientist Manuel Casanova, now at the University of Louisville School of Medicine in Kentucky. In 2002, Casanova and his colleagues published data showing abnormalities in postmortem autistic brains in cortical minicolumns. These are groups of 80 to 100 cells that extend inward from the brain's surface and function as information processing units. The nine autistic brains that Casanova's team examined had many more—but much smaller—minicolumns than nine control brains had in certain portions of the frontal and temporal lobes, the researchers reported in Neurology. Having more minicolumns would create an abundance of short connective fibers relative to long ones, perhaps accounting for the disproportionate increase in white matter relative to gray matter in autistic brains.

    And in unpublished findings from seven autistic and seven control brains, Casanova and Christoph Schmitz of the University of Maastricht in the Netherlands and their colleagues found that the autistic brains also had smaller cells in their minicolumns. Smaller cells carry shorter axons, bolstering the hypothesis that autism results from too many short-range connections and not enough long ones.

    Even if a neuronal imbalance is to blame, no one knows how it arises. Courchesne and others hypothesize that it might result from a problem in the pruning, or elimination, of neurons and synapses early in life. Work from Courchesne's lab from 2003 suggests that most of the abnormal brain growth in autism occurs from birth to age 3. This may leave an unruly excess of neurons and circuitry in certain brain regions.

    Not too deep.

    Autistic brains contain an excess of surface white matter (yellow), which contains relatively short neuronal fibers, but do not show an enlargement of deeper white matter (white), where the longest fibers reside.

    CREDIT: MGH/CENTER FOR MORPHOMETRIC ANALYSIS

    More questions than answers

    Despite the converging evidence, not everyone is convinced that faulty connections lie at the heart of autism. Geraldine Dawson, an autism researcher at the University of Washington, Seattle, suggests that connectivity problems in autism might be an effect—rather than a cause—of an earlier dysfunction in the brain, such as a defect in brain systems that govern social reward and affect an infant's attention to faces and speech. Such a defect, Dawson says, “will influence the development of speech and face perception, which ultimately will affect the development of the complex, integrated brain circuitry that underlies language and social development.”

    Even if connectivity problems are at the root of autism, the theory needs fleshing out. Abnormalities in brain connectivity have also shown up in attention deficit hyperactivity disorder (ADHD), schizophrenia, and dyslexia. To get to the heart of autism, researchers now need to pinpoint which particular white matter—or gray matter—abnormalities are the problem in autism versus, say, dyslexia or ADHD, skeptics point out.

    Even so, proponents argue that the theory at least points researchers in the right direction. “It's a much more valid way of looking at impairments in autism. It's where the field of autism has to go,” Müller says. And no matter where connectivity theory leads, the autism field is energized by the concept. Says Courchesne: “People smell something really exciting. They are seeing that there is a very interesting, if complex, story emerging.”

  10. PHARMACOGENOMICS

    Going From Genome to Pill

    1. Robert F. Service

    A new medicine for African Americans with heart failure hints at what the drug industry sees as the enormous payoff from pharmacogenomics

    Last week an advisory panel to the U.S. Food and Drug Administration (FDA) took an unprecedented step in recommending approval of a drug for a single racial group. The drug, a combination pill called BiDil that contains two heart-failure medications, had failed to help patients in the general population live longer. But in a clinical trial last year, BiDil decreased the risk of death among African Americans by 43%. That was sufficient evidence to convince the panel that BiDil should be approved to treat African-American patients with heart failure. FDA was widely expected to follow the recommendation this week.

    By backing BiDil, the FDA panel gave another push to pharmacogenomics, an approach that promises to revolutionize both drug discovery and patient care. African Americans have a higher likelihood of developing hypertension and other conditions related to heart failure. However, whether that's due to genes, the environment, or some complex interplay isn't yet known. Still, BiDil represents the latest example of the industry's push to target drugs to subgroups of patients who, based largely on their genetic makeup, are most likely to benefit (Science, 24 October 2003, p. 594). In recent months studies have shown potential benefits of medicines targeted to patients with specific genotypes for treating cancer and heart disease. Other studies have helped doctors properly dose a wide variety of compounds already on the market. “I think that the use of pharmacogenomics will have a profound effect,” says Gary Peltz, head of genetics and genomics research at Roche's Palo Alto, California, lab. “It hasn't hit yet. [But] we're clearly on the road.”

    To date, pharmacogenomic therapies represent a trifling portion of pharmaceutical sales, some $3.65 billion in a $550 billion market. That won't change unless scientists overcome an array of challenges, from untangling the genetics behind complex diseases such as diabetes to altering practices that could disqualify patients for health insurance based on their genes. There are also concerns that approval of drugs based on race, a sociological trait, will increase racial stereotypes and bolster the discredited notion that there are fundamental genetic differences between races. But those problems, say drug industry officials, pale in comparison to the projected benefits to patients—and to the industry. “Every major pharmaceutical company is reorganizing or has reorganized their clinical paradigm” to test drugs in conjunction with tracking genes or other molecular markers of disease, says Ronald Salerno, who directs regulatory affairs for Wyeth Pharmaceuticals in Collegeville, Pennsylvania. “This is the way drugs will be developed in the future.”

    Improving the odds

    Although pharmacogenomics only recently entered the lexicon, the notion of treating populations based on the genes involved in health and disease dates from the 1950s. That's when researchers caught an initial glimpse that the speed at which different people metabolized drugs in their system was linked to genetics. But it took another 40 years to progress from those hints to medicines. In 1997, Genentech's Herceptin was approved to fight a form of breast cancer in which cancer cells overexpressed a protein called the HER2 receptor. In 2001, Novartis won approval for Gleevec to treat a form of cancer called chronic myeloid leukemia, in which an aberrant gene triggers a proliferation of white blood cells. And last year, ImClone's Erbitux went on sale to fight colon cancer by targeting a growth factor receptor on tumor cells. Since 1996, doctors have also genotyped the HIV viruses present in AIDS patients to help them select the best combination of drugs to treat the disease. The completion of the human genome project in 2001 allowed drugmakers to scan humanity's entire genetic sequence for links to a wide swath of diseases.

    Breakdown.

    Drug-metabolizing enzymes, such as CYP2C9 (structure above), come in many versions. People who are poor metabolizers break down drugs slowly, increasing toxicity concerns. Ultrametabolizers break them down quickly, lowering the chance that the drug will work. Intermediate and extensive metabolizers fall in the middle.

    SOURCE: GENELEX CORPORATION; (STRUCTURE) RESEARCH COLLABORATORY FOR STRUCTURAL BIOINFORMATICS

    Although pharmacogenomics is expected to be useful throughout the drug development pipeline, its greatest effect at present is on how clinical trials are conducted. In particular, it's helping researchers identify which patients are most likely to benefit from a drug. Better screening of novel compounds for efficacy, toxicity, and side effects should mean fewer compounds falling by the wayside once they enter late-stage trials, the biggest component of the $1-billion-plus cost of bringing the average drug to market. “If we can get the attrition rate down, even the most reluctant managers will shift,” says Mitch Martin, who heads genomic research at Roche's Nutley, New Jersey, R&D center.

    Having a better idea of the likely beneficiaries of a drug also increases the odds of identifying the best therapeutic dose. Take the example of warfarin, a blood-thinning compound used by 2.1 million Americans every year to lower the risk of heart attack and stroke. Too little of the drug can be ineffective, but too much of it can cause dangerous internal bleeding and other potentially fatal consequences. Moreover, there is a 120-fold difference in the dosages given to different patients depending on the suite of enzymes each patient carries that break down the compound. Finding the right dose depends largely on repeated blood tests and a lot of trial and error.

    That may soon change. This month, researchers at the University of Washington, Seattle, and Washington University in St. Louis, Missouri, reported in the New England Journal of Medicine that as much as 25% of this dosage difference can be explained by variations in a gene encoding an enzyme involved in blood clotting called vitamin K epoxide reductase complex, subunit 1 (VKORC1). After examining medical records and blood samples from more than 550 patients and sequencing their VKORC1 genes, the researchers found 10 common variants of the gene. Patients clustered into three groups requiring high, medium, or low dosages. These clusters, it turned out, were closely linked to racial heritage. African Americans were most likely to have a genetic makeup requiring a large dose of the drug, whereas Asian Americans more often required a low dose and European Americans were split between the two groups.

    The bottom line for physicians is both obvious and subtle, Martin says: Genotyping patients can save lives, and finding the right dosage may help get a drug through clinical trials. A traditionally run clinical trial will select a dosage that ensures safety for all participants, Peltz points out. If 10% of patients can tolerate only a low dose of a particular drug, that dosage will become the standard of care. That means 90% of patients won't receive an optimal dose, decreasing the chance that the drug will be shown to be effective. “The real value is in increasing the probability of bringing a compound to market,” says Nicholas Dracopoli, a pharmacogenomics expert at Bristol-Myers Squibb in Princeton, New Jersey.

    Another major role for pharmacogenomics is expected far upstream in the process: helping companies determine which among the myriad possible proteins and other compounds in the body make the best targets for drugs. Traditionally, drug target hunters would work with mice and other animals to knock out the gene for each target individually or overexpress it to determine its effect on the animal's health. But animal models often don't mimic human disease closely enough. With pharmacogenomics, however, researchers who identify a gene that may be involved in a disease can look to see if a common variant is shared by a large number of patients and then identify the protein involved. “It's a way for us to put all the targets on the same playing field and see which ones confer risk and rank-order them,” says Martin. “We're going to use this because we think it will help us make better decisions.”

    Picking winners

    Even so, most industry experts agree that the technology is not yet ripe for a complex disease such as diabetes, which is triggered by a wide range of genetic and environmental causes. That's also true for conditions such as hypertension, in which doctors can already get a rapid readout on the effectiveness of a drug just by performing a simple test, such as checking a patient's blood pressure.

    By contrast, cancer seems a promising target. “In oncology patients, it's very important to treat with an optimal therapy in the first cycle,” Dracopoli says. “Every time it fails, the tumor becomes more systemic, more drug-resistant, and harder to treat.”

    The fact that cancer is typically initially examined with a biopsy and, in some cases, surgery gives doctors tissue samples that can be used to genotype the cells present. In theory, says Dracopoli, the next step would be to select a drug most appropriate for combating that form of cancer. Last month, for example, researchers led by Michael Heinrich of Oregon Health and Science University in Portland reported new evidence of Gleevec's ability to treat a form of gastrointestinal cancer, abbreviated GIST. Gleevec works by inhibiting a protein called KIT, which is abnormally expressed in GIST and fuels tumor growth by signaling cancer cells to keep growing. The majority of GIST patients initially respond well to Gleevec. But after 2 years, more than half develop resistance to the drug.

    In a previous study, Heinrich's team found that patients with a mutation on a region of the KIT gene called exon 11 were far more likely to respond well to Gleevec over time than were patients with a different mutation on exon 9. In a paper he presented at the American Society for Clinical Oncology (ASCO) meeting in May, Heinrich confirmed this result with a much larger set of patients and also revealed the best dosing for GIST patients. Meanwhile, in another study at the same meeting, researchers led by George Demetri of the Dana-Farber Cancer Institute in Boston, Massachusetts, reported that a Pfizer compound called Sutent was more likely to improve the outcome among GIST patients with a KIT mutation on exon 9.

    Not so simple.

    People with different forms of the enzyme CYP2D6 respond differently to some antidepressants, such as imipramine, but similarly to others, such as sertraline. In the graph above, the normal dose is 100%. Poor metabolizers of imipramine, for example, can only tolerate 25% of that amount.

    SOURCE: GENELEX CORPORATION

    Another major push for pharmacogenomics research is deciphering the genetics behind the metabolism of different drugs in the body. A classic example is a compound known as 6-mercaptourine, or 6-MP. The drug has long been used to treat children with a form of blood cancer known as childhood acute lymphocytic leukemia (ALL). But one in every 300 children has a variant of a gene for an enzyme called thiopurine methyltransferase that prevents 6-MP from being metabolized. In those patients, the drug builds up and in many cases has proven fatal. Beginning in the 1980s, researchers led by Richard Weinshilboum at the Mayo Clinic in Rochester, Minnesota, flagged the genetic link to the slow metabolism of 6-MP. Now doctors increasingly run genetic tests on ALL patients before giving them 6-MP to weed out the patients who shouldn't receive the drug.

    That same strategy is also being used to unravel the genetics behind a broad range of drug-metabolism enzymes, known as cytochrome P450s, that are present primarily in the liver and kidneys. The impact could be dramatic: Variations in just one of these enzymes, known as CYP2D6, have a broad effect on drug metabolism, according to a report this month in Nature Reviews Drug Discovery by health policy experts Kathryn Phillips and Stephanie Van Bebber of the University of California, San Francisco. “The most commonly used drugs metabolized by CYP2D6 account for 189 million prescriptions and $12.8 billion annually in expenditures in the U.S., which represent approximately 5% to 10% of total utilization and expenditures for outpatient prescription drugs,” the authors conclude.

    Whether researchers can tie patients' responses to all these drugs to variations in CYP2D6 genes remains to be seen. But they have made some progress. Researchers led by Matthew Goetz, a medical oncologist at the Mayo Clinic in Rochester, Minnesota, reported at the ASCO meeting that genotyping drug-metabolism enzymes can drastically reduce the risk of toxic side effects from a standard chemotherapy regimen containing three cancer drugs, called irinotecan, oxaliplatin, and capecitabine. Despite the drugs' antitumor benefits, their combined use can be lethal for some patients. But Goetz's team found that genetic variants of an enzyme abbreviated UGT1A1 determined what dose of irinotecan could be tolerated, as well as whether the drug works with the others.

    Finally, pharmacogenomics is also opening up new markets for biomarker companies with the tests needed to draw the link. Last December, for example, FDA approved a new gene chip from Roche called the AmpliChip, which tests for common variants of two important genes for drug metabolism, CYP2D6 and CYP2C19. A Seattle, Washington, company called Genelex recently started marketing an alternative test directly to consumers.

    Despite these and other enticing results, even pharmacogenomics proponents warn against expecting a medical revolution. “It's not something that's going to change the world in 3 years,” says Scott Weiss, a pharmacogenomics researcher at Harvard Medical School in Boston. Among the hurdles, Weiss and others say, is that studies linking genes to disease outcome are time-consuming and expensive. That means higher costs in the short run.

    Doctors also must be trained to use and properly interpret genetic tests. “Doctors have to buy in,” says Wyeth's Salerno. One reason they might resist, Salerno suggests, is a fear of being second-guessed by lawyers. “If someone gets injured from an adverse event [from taking a drug], will that person ask why the doctor didn't check my genotype?” Salerno asks. Finally, patients must become comfortable with the notion not only of having their genomes tested but also with the possibility that insurance companies might exclude coverage for a particular disease, arguing that a genetic link makes it a preexisting condition.

    Many of these changes will take time. But that's fine, Salerno says, because the field of pharmacogenomics is still young. “This is not a fad,” Salerno says. “This is going to be a cornerstone of future medicine.”

  11. CENTRAL ASIA

    Visions of a Biotech Empire on the Kazakh Steppe

    1. Richard Stone

    Kazakhstan has enlisted a U.S.-trained biologist to clear out the cobwebs and create a modern biotechnology industry

    ASTANA, KAZAKHSTAN—When Erlan Ramanculov moved from Colorado to Kazakhstan in 2004, he and his wife had one main objective: to raise their daughters in his native land. He took a position managing four struggling biological institutes in Almaty, the largest city in this oil-rich Central Asian country. Sometimes, though, as the 38-year-old molecular biologist dealt with a stultifying bureaucracy, he wondered whether he'd erred in leaving the United States. He'd spent 11 years at Texas A&M University in College Station and the U.S. Centers for Disease Control and Prevention in Fort Collins, Colorado, becoming a topflight researcher on phages, viruses that infect bacteria.

    Then in February, Ramanculov was tapped to build a national biotech program with resources far beyond anything he could have imagined back in the States. The government has approved plans and is now reviewing financing for a $50 million Life Science and Biotech Center of Excellence, supported in part by the World Bank, with a flagship research facility to be built in Astana, the nation's capital. Ramanculov, director of the new center, has enlisted an advisory board to set research directions and has begun wooing top Kazakh expatriate and foreign scientists. “The center will be a testing ground for new principles, fully integrated into the world scientific community,” says Kazakhstan's reform-minded deputy science minister Azamat Abdimomunov, who has championed the project.

    The challenges are formidable. The most obvious is acquiring hardware: Kazakh researchers are mostly making do with Soviet-era equipment. They also must overcome Western concerns about proliferation. Subsumed in Ramanculov's center is an institute in Stepnogorsk that was once the world's largest biological weapons production facility; U.S. State Department officials have urged Kazakh officials not to let its weapons experts get lost in the shuffle.

    Young Turkics

    The driving force behind Kazakhstan's planned biotech revolution is Abdimomunov, a 29-year-old political scientist trained at Harvard University's John F. Kennedy School of Government. Since his appointment in January, the blunt-spoken Abdimomunov, keen on flow charts and Venn diagrams, has floated plans for stricter evaluations of institutes. He also wants to infuse fresh blood by expanding a popular program, Bolashak (for “the future”), which pays tuition and stipends for elite university students to study abroad.

    Dark past, bright future?

    The former bioweapons complex at Stepnogorsk is part of a radical overhaul of Kazakhstan's biotech program led by Erlan Ramanculov (inset).

    CREDITS: R. STONE

    The new biotech center is his boldest move yet, in part because it is a rebuke to Stepnogorsk. The “Progress” Technopark established in Stepnogorsk in 2002 was supposed to usher in a biotech marvel, producing everything from amino acids to vodka. But a science ministry document says that despite large cash infusions, it has “failed to produce any result.” “Unfortunately, we have been more successful at dismantling equipment than putting things together,” acknowledges Progress president Valeriy Shimanayev. The science ministry plans to dissolve Technopark this month.

    Abdimomunov faults local managers and a U.S. assistance effort that he claims paid short shrift to commercialization. He vented his frustrations to one U.S. State Department official in what both sides called an “uncomfortable” encounter this spring. “The American side should have expressed a greater desire to assist us,” Shimanayev says. Comments a U.S. official: “You can't just keep pouring aid in forever.”

    State will keep a close eye on the new biotech center because, the official says, “there are people in Stepnogorsk who we don't want to see go without work.” The United States, Canada, and other countries have thrown a lifeline to a few dozen key weaponeers at Stepnogorsk, primarily through the International Science and Technology Center (ISTC), a multilateral fund. How to balance nonproliferation concerns and Kazakhstan's biotech aspirations is to be discussed at a meeting this month between U.S., ISTC, and Canadian officials.

    Ramanculov aims to make the most of Kazakhstan's decaying infrastructure. He plans to seek World Bank help to raise standards across a wide front. “Every research group in Kazakhstan is a monopolist in its own small field. Nobody in the country can judge their work,” Ramanculov says, adding that a lack of competitiveness has fostered poor science and a dearth of investment. The science ministry plans to rate scientists by citation index. “We're changing the rules of the game: People are going to have to work harder,” Ramanculov says. Still, he says, “we cannot produce a cutting-edge research facility from our local cadres. We have to bring people in here.”

    That will be no mean feat. Winters on the steppe here are fiercely cold, windy, and snowy, whereas summers are hot and buggy. Ramanculov hopes six-figure salaries will lure talent. “We need to bring in a few big guys,” he says. Ramanculov will also be able to rope in 40 Bolashak-trained biologists in a few years when they return home from their studies. His former Ph.D. supervisor thinks he can succeed. Ramanculov “is a risk taker” with “tremendous drive and resolve,” says Ry Young, a phage biologist at Texas A&M. “If this project can be successfully done, it will get done. Few people can resist his personality.”

    Having secured land on the Ishim River, Ramanculov has hired a Singapore-based firm, Jurong Consultants, to draw up designs for the research center and apartments for scientists. Construction is slated to begin next year. By next month, Ramanculov says, outside advisers will recommend areas in which the center might compete globally. “Whatever we do will be good,” he says, “because not enough has been done in Kazakhstan.” The changes sweeping Kazakh science have convinced Ramanculov that coming home was the right decision after all.

  12. CELL BIOLOGY

    The Ins and Outs of Exosomes

    1. Jennifer Couzin

    Cells spit out these mysterious vesicles, but what they do and whether they boast medical uses, such as in cancer vaccines, is up in the air

    MONTREAL, CANADA—”Alice in Blunderland” is how biochemist Rose Johnstone describes her 1970s investigations into curious, lipid-encased particles burped out by the sheep red blood cells she was studying. Baffled by the material, which resembled “little florets” under a microscope, Johnstone, of McGill University in Montreal, nevertheless pursued them, gradually drawing in a small cohort of scientists. She anointed the vesicles exosomes; unlike similar-looking structures called endosomes, which carry material into cells, these particles seemed to cart stuff away.

    Three decades later, exosomes are beginning to surrender their secrets. Scientists now know that they have been conserved across species, suggesting useful, even life-preserving functions. Exosomes secreted by white blood cells, for example, appear to mediate immune responses, activating and perhaps also suppressing the immune system. Indeed, cancer physicians are already trying to exploit exosomes to trigger immune response against a variety of tumors. And other researchers are exploring whether these vesicles assist the spread of HIV and prions.

    In one indication of the exosome's coming of age, the first-ever meeting* devoted to these particles was held here last month, organized by Johnstone and sponsored by the Leukemia and Lymphoma Society. About two dozen biologists from eight countries converged in a classroom at McGill University for 2 days of spirited discussion. Although exosomes are no longer dismissed as simple cell fragments, their biological significance remains tantalizing but uncertain. “Many people think exosomes are pieces of cell running around with no specific function,” said Sebastian Amigorena of the Curie Institute in Paris. “I want to believe they're doing something.”

    Unexpected finds

    Most cell biologists enter the exosome field after they stumble across the particles in their experiments. That was the case for Johnstone. She and her colleagues first saw what she would later call exosomes while hunting for an elusive amino acid transporter. Examining blood drawn from sheep, they saw that the immature red blood cells were ejecting “tons of stuff” after binding to an antibody, says Johnstone. The red blood cells of chicks, piglets, frogs, rats, and humans all produced these vesicles. Her group ultimately reported in 1983 that exosomes help nascent red blood cells develop by carting away proteins that are no longer needed.

    But exosomes lingered in obscurity until 1996. That year, Graça Raposo and Hans Geuze of Utrecht University in the Netherlands and their colleagues reported that other blood cells, called B cells, secrete exosomes that offer up antigens—tiny bits of pathogens—to the T cells of the immune system. Such antigen presentation is a key initial step in launching an immune response. And exosomes were found to sport the crucial major histocompatibility complex molecules that bind to and display antigens, just as dendritic cells of the immune system do. Indeed, the presence of these immune molecules is one of the identifying signatures of an exosome, along with a characteristic lipid membrane.

    Taking shape.

    Microscopic vesicles called exosomes are secreted from many cell types, everything from intestinal cells to blood to cancer cells; here, exosomes appear as cup-shaped vesicles (left) or are labeled as black dots inside a larger cell structure (right). Scientists are only beginning to piece together their functions and importance.

    CREDITS: B. FÉVRIER AND G. RAPOSO, CURRENT OPINION IN CELL BIOLOGY 16, 1 (2004), ELSEVIER LTD.

    Raposo later moved to the Curie Institute, where she and her exosomes attracted other scientists interested in the role these vesicles play in T cell activation. One question is whether exosomes need a partner to arouse T cells, and if so, how that dance is choreographed. Clotilde Théry of the Curie Institute believes that exosomes and dendritic cells work in concert. She and her colleague Laurence Zitvogel, of Paris's Gustave Roussy Institute, have found that, like a relay racer handing off a baton, exosomes in a test tube pass certain antigens onto dendritic cells. The dendritic cells then use those antigens to activate T cells. Whether this also happens inside an animal is unknown.

    Dendritic cells themselves appear to produce exosomes, as do an ever-lengthening list of other cell types. For instance, cells at the outer edges of the intestine and cancer cells have also been shown to secrete the vesicles.

    Lassoing a skittish target

    Finding that additional cell types make exosomes has only added to confusion over what they do. Further complicating matters is that the particles are maddeningly awkward to work with. “It's difficult to manipulate [and] purify them,” says Amigorena.

    Aled Clayton of Cardiff University in Wales, U.K., who has followed up on reports that cancer cells secrete exosomes, can attest to that. He theorizes that these exosomes might suppress the immune system rather than activate it, letting the cancer flourish. But despite examining exosomes ejected by various cancer cells, including breast cancer and mesothelioma, he can't produce sufficient data to back up the conjecture. After months of painstaking work with the particles, “we've failed miserably at generating any immune responses from exosomes,” he confessed at the meeting.

    While most exosome researchers have focused on the vesicles' apparent ability to switch on the immune system, Clayton and others continue to probe whether the vesicles play an opposing role in immune suppression. Last month, in the Journal of Immunology, molecular biologist Paul Robbins of the University of Pittsburgh, Pennsylvania, reported that exosomes he stumbled across while studying gene therapy for arthritis could heal the autoimmune disease. Trying to understand why delivering gene therapy to one arthritic joint in a mouse helps nearby joints too, Robbins and his colleagues noticed small vesicles traveling from treated joints to untreated joints. “I thought it was cell debris,” says Robbins. But when he and his team culled these vesicles from dendritic cells and reinjected them, they found that a single injection into an arthritic animal eliminated the disease. “Our exosomes are very suppressive,” says Robbins.

    Switching on.

    Experiments suggest that exosomes can help activate T cells like this one, but debate continues over how they do so.

    CREDIT: STEM JEMS/PHOTO RESEARCHERS INC.

    Supporting that premise, Helen O'Neill of Australian National University in Canberra told the Montreal gathering of studies showing that exosomes appear to reflect the behavior of the cells that release them; immature dendritic cells and their exosomes, which Robbins used, tend to suppress immunity, whereas mature ones and their exosomes stimulate it. Work by Amigorena, Théry, and others published in March in Blood did not find this distinction, however.

    These finer questions were sometimes overshadowed by more fundamental ones. Do all the vesicles being classed as exosomes really fall into that category? In other words, is everyone studying the same thing? Meeting participants reached no consensus on whether the definition of an exosome should be based on the vesicle's chemical makeup, on how it was formed, or on its purpose. Cell biologist Stephen Gould of Johns Hopkins University in Baltimore, Maryland, argued for a broad characterization. “The more narrow you make the definition, the less interesting this field will be to everyone else,” he said.

    Tackling cancer

    Such fuzziness hasn't stopped oncologists from incorporating exosomes into so-called cancer vaccines, which seek to trigger immune response against tumors. One strategy involves filtering exosomes produced by dendritic cells from a patient's blood. The theory is that these exosomes, produced by dendritic cells that can activate the immune system, sport tumor antigens and can induce a strong immune attack on an individual's cancer if redelivered in sufficient volume.

    A Menlo Park, California, company called Anosys, co-founded by Jean-Bernard Le Pecq, funded a small trial in lung cancer and another in melanoma before folding this spring. The exosomes failed to help most of the melanoma patients, Zitvogel, who ran the trial, reported in Montreal. But those with lung cancer fared relatively well, Le Pecq noted, with a handful surviving several years—unusually long for people with the aggressive cancer. One unexpected complication was that not enough exosomes for an individualized vaccine could be extracted from the blood of every volunteer.

    Meanwhile, oncologist Malcolm Adams of Cardiff University is working with Zitvogel to launch an ovarian cancer trial of an exosome-based vaccine. Their strategy is slightly different from that used in the lung cancer and melanoma trials: Here, exosomes will be harvested from tumor cells in abdominal fluid. Such cells and their exosomes should bear antigens specific to the individual's cancer. And if the exosomes are administered along with a substance that stimulates the immune system, the vesicles may train the immune system to recognize cancer cells as foreign and attack the cells, suggest Adams and Zitvogel.

    Some exosome biologists are investigating whether the particles play a nefarious role in infectious diseases, such as spreading viruses from cell to cell. In 2003, Gould and his colleagues published a provocative theory about HIV dubbed the “Trojan exosome hypothesis.” They proposed that retroviruses, such as HIV, hide as exosomes secreted from an infected cell.

    In Gould's theory, the HIV exosomes are released from an infected cell and drift toward one that's not infected. That cell takes them up, internalizing the deadly virus. The theory doesn't discount that HIV can directly infect cells, but it suggests that exosomes offer an alternative way for the virus to spread. In Montreal, Gould reported that exosomes bud from domains in the plasma membrane of T cells, which HIV infects. Bolstering his theory, he's also found that HIV Gag, a protein the virus needs to exit a cell, congregates in exosomes.

    But HIV researcher Michael Marsh of University College London questions parts of the Trojan exosome hypothesis. Although Marsh believes that HIV and other retroviruses might assemble in the same endosomal cell compartments that spit out exosomes, he says he's never seen the exosome budding from the cell surface that Gould reports.

    In addition to HIV, exosomes may act as infectious pawns for prions, misshapen proteins suspected in several neurodegenerative conditions such as “mad cow disease.” Raposo has recently published data indicating that exosomes act as vehicles for prion transport between cells. She noted that prions appear to accumulate in endosomes as they near the point of spilling their exosome cargo. Exosomes “probably have something to do with transmission of the infectious agent,” she says. In the case of ingested beef causing mad cow disease in people, this could mean ferrying prions from the gut to the central nervous system.

    Raposo's prion work—which, she says, elucidates “the dark side” of exosomes—hints at the breadth of potential roles for these vesicles in health and disease. But like so much exosome work, it remains dogged by uncertainties and questions.

    • *Exosomes: Biological Significance, Montreal, Canada, 20–21 May.

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