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When the Genome Gets Personal

By Nonie Arora

It has been almost ten years since the first draft sequence of the human genome was completed in 2003, and some patients are starting to see benefits in clinic.

Dean Nancy Andrews

Dr. Nancy Andrews, Dean of the School of Medicine, recently spoke to undergraduate students about “When the Genome Gets Personal” over a hearty dinner of chicken stuffed with goat cheese, rice pilaf, and caramelized brussel sprouts. She was the latest guest in the 2012 Chautauqua West Lecture Series.

Andrews explained how DNA sequencing analysis can lead to a new diagnosis for patients. Even if the disease is not treatable, a diagnosis can mean a lot to patients and families, said Andrews.

“We are pushing boundaries between taking care of patients and doing research. The lines are blurry,” she said. Researchers want to sequence patient DNA to find causes for genetic diseases and, at times, to help individual patients who don’t have a diagnosis, according to Andrews.

She said it is easy to find variations in DNA sequence, but much, much harder to know how to interpret the changes. One of the tricky situations researchers face is telling parents or patients what they have found when they are not certain of the finding’s significance. She chairs a committee at Duke that is working on standards to help guide researchers to know what to report and how to design informed consent forms.

Andrews said DNA sequencing is already being used in clinical care: about $5 billion a year is spent on clinical sequencing. However, this sequencing is highly focused on genes relevant to the clinical situation; insurance companies will not yet support exploratory whole-genome sequencing. Andrews pointed out that there is a potential for exploitation by private for-profit companies with DNA sequencing capability, which may overstate their claims or capabilities.

Complicated scenarios can arise when sequencing is done in families. Among other issues, “There is a very real possibility of learning dad is not the biological father,” Andrews said.

Example of a pedigree generated from discussion of family history with patients, modified from Wikimedia Commons

Andrews said that clinical geneticists are going to need algorithms for interpreting sequence data and standard principles for revealing information for patients. These are under development at Duke and across the country.

Ultimately, Andrews thinks that personalized medicine “shouldn’t just be about genetics and genomics but [it should] also incorporate many other types of clinical data, including imaging studies and patient preferences, as well as a deep understanding of environmental factors.”

 

 

New Technologies Threaten Cognitive Liberty

By Nonie Arora

Nita Farahany, Duke Law School Professor

Where do we draw the lines when it comes to new technologies in neuroscience?

Duke Law professor Nita Farahany is setting out to answer this question through an exploration of something she calls cognitive liberty. She spoke to a crowd of physicians, nurses, faculty members, and students at the last Trent Center Humanities in Medicine Lecture Series event.

“What does it mean if our conscious awareness of making a decision happens after the decision has already been made by our brains? Does that tell us anything about the concepts of responsibility or freedom of thought?” Farahany asked.

She doesn’t buy into the idea that we are absolved of responsibility because we are essentially predetermined machines, even if scientists like Benjamin Libet have shown that there is brain activity before conscious awareness. She argues that although some things are predetermined, we still have the flexibility of choice. For instance, having many fast-twitch muscle fibers may be a precondition of becoming a world-class track athlete, but the choice remains of whether to train extremely hard to reach the goal.

“We are more than preprogrammed bits and bytes,” Farahany said. Under the assumption that we retain flexibility of our thoughts, Farahany is exploring how those thoughts ought to be protected.

Although neuroscience is still in its infancy, it holds the potential to detect and tamper with memories, she said. But she hopes to explore what types of rights we ought to retain and what limitations there ought to be on the technology.

Farahany said that the mind might hold a lot of information that is very valuable to the government and to businesses. She pointed out that our brains can uniquely identify speakers and sounds. New technologies could detect this information, which could be very valuable to a criminal investigation. But it is it permissible to detect our recognition of objects or people?

Eyewitness testimony has a high rate of falsity and sometimes witnesses lack memories of key information. However, what if false memories could be planted in eyewitnesses easily? Most people would agree that it would be impermissible for the government to create its own “star witness,” Farahany maintained.

Propranolol, a beta-blocker that may stop consolidation of fear. Courtesy of Mind Disorders

While many may worry about enhancement of selves or memories, diminishing memories is another concern. The drug propranolol, a beta-blocker, has significant promise for people who have suffered from a traumatic experience because it can block consolidation of fear, said Farahany. For instance, rape victims who take propranolol may be less likely to develop post-traumatic stress disorder. “When given the opportunity to intentionally diminish experience of an emotion, should [people] be able to do so?” she asked. Compensation through the tort system is based upon the degree of suffering. Would the compensation for a victim of a rape be decreased by using the drug? Alternatively, do victims have a responsibility to reduce their own suffering by taking the drug?

There are many more questions to answer, and Farahany hopes to do so with her framework of cognitive liberty that considers the pillars of self-determination, consent, freedom of thought, and risks and benefits to individuals and society when deciding where to draw the lines.

 

Gecko's stick inspires adhesives and even superheroes

By Ashley Yeager

A single hair on a gecko’s foot has enough “stickiness” to pick up an ant. Credit: Kellar Autumn, Lewis & Clark College.

Sticky feet driving you up the wall?

Well, maybe not. But they are for Cicak, or Gecko-Man. After a few sips of coffee contaminated by a virus-infected gecko, a loser lab scientist suddenly becomes a Malaysian superhero, sticking to walls, using his tongue to scale skyscrapers and even eating bugs.

“Gecko feet are nature’s best adhesion and removal device,” said Lewis & Clark College biologist Kellar Autumn. He gave the keynote speech during the awards ceremony of the third annual Abhijit Mahato photo contest on Nov. 7.

While Autumn riled up the audience with his images and videos of the science behind gecko feet and their inspiration for new adhesives, robots and superheroes, he also used the talk to remind the photographers in the audience that appearance and scientific images can be misleading.

The science of how geckos climb up walls and across ceilings is at least a 200-year-old question, one that even Aristotle tried to answer. In the late 1960s, one scientist took some scanning electron microscope images of gecko feet and thought they revealed suction cups as the mechanism that let geckos scale walls and ceilings. But that idea was wrong.

It wasn’t until Autumn and his collaborators began looking more closely at the creature’s feet in the late nineties and early 2000s that scientists realized it wasn’t suction, but nanometer-scale interactions between a surface and the gecko’s foot hairs, or setae, that let them stick, release and climb. His team took a single gecko foot hair and made the first direct measurement of its adhesive function. Turns out the stickiness in one hair is so strong it can lift the weight of an ant.

The team also discovered that geckos release their feet as they climb by changing the angle of their feet hairs. That means that the contact geometry of setae are more important that any other factor in their ability to climb, Autumn said, adding that the discovery demonstrated “we could make this stuff.”

Tom Cruise climbs a skyscraper with “gecko gloves: in MI:Ghost Protocol. Image courtesy of: Danny Baram.

He showed videos of both the kinematics and kinetics of the way geckos climb and compared and contrasted the physics the creatures use to the human-engineered “nanopimples” and wedge-shaped nanoridges that resemble geckos’ sticky feet. The animal’s foot physics is “different than pretty much everything else out there,” Autumn said, though he did describe several developing projects to try to mimic the animals’ movements.

Still, he said, he’s convinced that “had geckos not evolved their sticky feet, humans would not have invented adhesive nanostructures.” And, there’s no way we’d have gecko gloves or could even think of gecko band-aides and the other cool applications of gecko-feet science, he said.

Citations:

“Adhesive force of a single gecko foot-hair.” Autumn, K., et. al. (2000). Nature 405, 681-685.

“Evidence for van der Waals adhesion in gecko setae.” Autumn, K., et. al. (2002). Proc. Natl. Acad. Sci. USA 99, 12252-12256.

“Evidence for self-cleaning in gecko setae.” Hansen, W. and Autumn, K. (2005). Proc. Nat. Acad. Sci. U. S. A. 102, 385-389.

Even ferns get Gaga

by Ashley Mooney

Biology professor Kathleen Pryer discussed the sex lives of ferns with a group of students Monday in the Center for LGBT Life.

“We’re trying to develop a new lifecycle (of ferns) that we hope textbooks will pick up,” Pryer said. “There are a range of ways that ferns have sex and each of these has is own evolutionary consequences and genetic outcomes.”

At the lunchtime lecture, Pryer also revealed her lab’s newly discovered fern species, Gaga germanotta, named after pop star Lady Gaga.

By naming a species after somebody outside of the world of scientific research, Pryer said she wanted to give Lady Gaga a namesake that will recall her activism efforts.

“The work that she’s done, the money that she’s put behind the Born This Way foundation, I think is incredible,” Pryer said. “She’s a real champion for justice and equality, and I wanted to do this so that she would have a scientific namesake—something that will last forever long after she’s gone.”

Lady Gaga also bears some likeness to a fern gametophyte, which is a fern early in its developmental cycle. At the 2010 Grammys, Lady Gaga wore a costume that strongly resembles a gametophyte, Pryer said.

The new species is part of a genus containing 19 species that were originally listed as cheilanthes. True cheilanthes—ones that have kept their original designation—are South American ferns that are nearly indistinguishable from Gaga ferns in appearance. Their differences, she said, are in their DNA.

“When we line up all our sequence data [of the Gaga ferns]… in a particular gene there is a string of GAGA,” she said. “The closest relatives of the genus Gaga doesn’t have that synapomorphy.”

Flowering plants—the most diverse types of plants on the planet with approximately 350,000 species—reproduce using seeds. Ferns on the other hand reproduce through spores contained on the undersides of their leaves.

Pryer noted that many people do not understand the vast diversity of ferns. There are about 12,000 species, including the typical forest ferns, aquatic ferns, desert ones and ferns that are the size of trees.  Pryer’s main focus has been on desert ferns—most of which appear similar but have different DNA patterns.

Beyond the variation in appearance of fern species, Pryer said the plants have multiple mating strategies, even though textbooks usually only teach one form.

Pryer describing the fern lifecycle often depicted in textbooks. Credit: Ashley Mooney.

One of the lifecycles they’re investivating involves a bisexual gametophyte, which is usually the first gametophyte in a population to mature. It forms a notch where it produces archegonia while antheridia develop on the outside. Most ferns have archegonium—the female component where eggs are located—and antheridia, which contain sperm. The gametophyte emits a pheromone that signals to all nearby developing gametophytes that they should become male.

Pryer said the diversity she found in ferns is only one type of sexual diversity in the world, and she hopes that a common interest in such differences will connect her field with the general population.

“We live in this world and we’re all interested in diversity in many different ways,” she said. “This makes a connection between what [scientists] do and human diversity and it also makes people who are Gaga fans say, ‘hey, what’s up with these botanists.’ I’m hoping that we can engage the two communities. When people talk about interdisciplinary work, I’m taking it to ‘the edge of glory.’”

YouTube Video about the naming: 19 Species of Ferns Named for Lady Gaga

Duke Today coverage: http://today.duke.edu/2012/10/gagafern

 

Refereed physics for Twitter and Facebook, maybe

By Ashley Yeager

These library stacks of science journals are going out of style as more publishers opt for online-only, open access formats. Credit: UCSF.

When journal publishers send peer-reviewed tweets, they’ll have truly entered the digital age. They’re not there yet, but that doesn’t mean they’re not trying, said Gene Sprouse, editor-and-chief of the American Physical Society(APS) and a physics professor at Stony Brook University.

Sprouse, speaking at an Oct. 17 physics colloquium, described how the Internet is changing the way scientists share their research. They used to submit papers to journals, have their ideas vetted by other scientists, and then see their arguments and data in print — or not. He said it has been this way since the 1660s when the first journal, Philosophical Transactions, was first published.

But with online journals available right on researchers’ desktop and open-access digital archives, such as arXiv.org, journal editors, like those at the helm of magazines and newspapers, are trying to figure out how to shift print publications online while still making a profit.

“Eventually print journals will disappear,” Sprouse said, explaining that sans paper, authors and publishers could include new types of content like movies and active graphics in their articles. But even with new media features, “what physicists want is rapid acceptance of their paper into a prestigious journal with no hassles during peer review. They want attention for their work, and they want it widely distributed.”

To meet those demands in the new media landscape, APS has developed a Creative Commons license for authors to share their articles on their personal web sites and encourages them to publish pre-prints in online digital archives, such as arXiv.org.

Hoping to merge the prestige of the “baby Nature” journals – Nature Photonics, Nature Optics, Nature Physics, etc. – with the open-access model of the Public Library of Science, or PLOS, journals, the society has also created Physical Review X.

It’s the society’s first online-only, fully open-access journal. The one-year-old publication, which charges authors $1,500 per accepted article, is already comparable in prestige to APS’s other leading journal, Physical Review Letters. The difference is that now authors have an open-access journal to submit to at APS, which is important as more funders push researchers to submit to that type of publication, Sprouse said.

The society isn’t ignoring Twitter and Facebook either. When asked when the society would post the first refereed physics tweet, Sprouse said he couldn’t really say because he personally doesn’t use social media. But, APS, he added quickly, is working on its social media strategy and would “welcome any advice from those of you exploring that realm.”

Stem Cells Raise Tricky Questions

By Nonie Arora

Medicine is about more than difficult diagnoses and cutting-edge research. Research and treatments often raise tricky moral questions.

Jeremy Sugarman Credit: Berman Institute for Bioethics

Dr. Jeremy Sugarman, the founding director for the Trent Center for Bioethics, returned to campus last week to give a talk on the ethics of stem cell research and treatment for the Humanities in Medicine Lecture Series.

“Stem cells are a hot topic that have captured the imagination of people around the world,” he said.

“Is it better to use leftover embryos from IVF or to create them for research?” Sugarman asked. He said there is little consensus on this issue, and the question remains whether there is a moral distinction between discarded embryos or those created for research purposes. There is also the thorny issue of whether it is morally acceptable to destroy embryos to create human embryonic stem cells, said Sugarman, who is now at the Berman Institute for Bioethics at Johns Hopkins University.

Amidst the controversy surrounding the moral status of embryos, there has also been scientific controversy within the stem cell field. Sugarman spoke of Hwang Woo-Suk, who claimed to have cloned human embryos and extracted their stem cells. However, his data was fabricated, Sugarman said. Sugarman elicited laughs from the packed audience when he joked about Woo-Suk’s former title “Supreme Scientist of Korea,” an honor that was later revoked. The laughter was tempered by the understanding of how unethical it is to fake any research, but especially on this scale. Still, Sugarman says Woo-Suk’s example serves to show the effectiveness of peer review in realizing false claims.

Human Embryonic Stem Cells. Source: "Follow the Money – The Politics of Embryonic Stem Cell Research." Russo E, PLoS Biology Vol. 3/7/2005, e234 http://dx.doi.org/10.1371/journal.pbio.0030234

Another issue many people are concerned about are chimeras – organisms that have parts from two different genetic lines. Already, bone marrow transplants create human-to-human chimeras, Sugarman explained. Some people have qualms about combining materials from human and non-human animals.

Other countries differ from the U.S. in policies on what can be done with human embryonic stem cells. For instance, in Germany it is a criminal offense to destroy an embryo to create a human embryonic stem cell line. It is also illegal for a German citizen to do such work abroad, Sugarman said. He brought up this point to illustrate why local oversight within academic institutions is necessary to not only make sure that research is “ethically and scientifically sound” but to also be certain that researchers are being protected.

Ethics in delivering care is equally important. “The desire for access to investigational treatments abounds, especially for devastating disorders,” according to Sugarman. But this is no reason for unsafe treatments to be delivered to patients. “It turns out some stem cell-based interventions are being delivered to patients without sufficient published data regarding safety or efficacy,” he explained.

Ultimately, scientific and commercial interests will be considered along with the hopes of patients and politicians when it comes to stem cell research and treatments, Sugarman said.

Crossing the Valley of Death

By Nonie Arora

David Adams shared his concerns about the output of America’s drug development pipeline at last month’s Science and Society Journal Club at the Institute for Genome Science and Policy (IGSP).

When it costs more than $1 billion to bring a drug to market with many failures along the way, “many (drug) companies are focused on de-risking,” according to Adams, an Associate Professor of Medicine in the Division of Medical Oncology.

Adams said the pharmaceutical industry seems to be counting on biotech companies and academia to help drugs cross the “Valley of Death” in anticancer drug development, but that has yet to happen.

While the rate of publication and quantity of scientific data continue to increase rapidly, not enough funding is being devoted to the “translational” research, which helps an idea make it from the lab to the clinic, Adams said.

Example of a tissue chip project sponsored through NCATS to improve drug safety. Credit to NCATS website.

The pharmaceutical industry has cut down on translational research, Adams said. Essentially, companies don’t want to take on projects unless they have a very high probability of success.

He also said that the National Institutes of Health (NIH) is generally risk adverse and tends to fund projects that represent “the next logical step,” rather than going for higher-risk, but potentially higher-gain ideas. The National Center for Translational Sciences (NCATS), established by the NIH director Francis Collins last year, is a promising step, Adams said.

When researchers design their cancer studies, many times they “don’t really take into account tumor physiology because we live in this era of molecular biology,” Adams said. He believes accounting for tumor physiology is very important. For example, doctors are rarely able to monitor how much drug makes it to a tumor, but translational research could solve this problem, said Adams.

Adams said drug development is also hampered by a human tendency toward  “technological lock-in.”

 

Personal Genome Machine Sequencer Credit: Benchmarks, a publication of the National Cancer Institute

“Why do we not change the way that we do things when there is compelling evidence to do so?”  He argued that:

1) people resist change in research and clinical environments because they are creatures of habit and convenience,

2) academics and clinicians often operate in silos rather than multidisciplinary teams that would enhance communication, and

3) we are obsessed with technology, as evidenced by genomics.

Adams said a new area to watch out for is theranostics: compounds that combine a therapeutic and diagnostic in the same formulation. Another area is miniaturization of electronics to permit real-time measurement of drug activity in and around tumors. An implantable radiation dose monitoring system is already commercially available and implantable sensors for management of diabetes are in the pipeline.

Ultimately, greater emphasis on translational research and breaking technological and organizational lock-in may help us cross this “Valley of Death,” he said.

'Chicken' Logic Secures Planes, Trains and Ports

By Ashley Yeager

U.S. goalkeeper Hope Solo deflects a penalty kick. Credit: AP

Soccer penalty kicks, ‘Chicken’ and other games may thwart terrorist attacks, drug smugglers and even freeloaders trying to board trains without tickets.

It’s not so much the intensity and adrenaline of the games that lead to better security, but the logic the players use, says Vincent Conitzer, a professor of computer science and economics at Duke.

This logic is called game theory and now scientists are using it to compute solutions for security issues, Conitzer explained at a July 11 talk with undergraduates completing summer research projects on campus.

During the talk, Conitzer gave a brief overview of game theory using real-world examples, such as penalty kicks in soccer and a set of drivers playing chicken. In the soccer example, he described a “zero-sum game” between the goalie and the kicker, where no matter the outcome, one player wins and the other loses.

But in the case of chicken, in which two cars drive straight at each other until one of the drivers “chickens out” and diverts course, the stakes of each choice are a bit higher. If both drivers stay straight, they crash. It’s no longer a zero-sum game.

When it comes to preventing security problems, there are more angles of attack, smuggler entry points and ways to board a train than the simple left, right or straight of these game examples.

Cars and buses wait to clear a security checkpoint at LAX. Credit: cardatabase.net

To make predictions about what the bad guys will do in the security scenarios, Conitzer is working with Milind Tambe and his group at USC. The team has designed game theory algorithms to set the schedule of security checkpoints and canine rounds at LAX airport, smuggler-scouting in Boston Harbor and even methods for preventing terrorist attacks in Mumbai.

Tambe “treats the problem of Mumbai personally” since that is his home city, Conitzer said, adding that he is only directly involved in this project with the USC group.

While the talk focused mainly on security applications, Conitzer also thinks that some “surprising new applications have yet to emerge” from the work. The new uses won’t necessarily help win a game of chicken or score a penalty kick.

But they could help scientists understand how to better use incentives to designgames with only good outcomes, such as encouraging smart energy use.

Citation: “Computing Game-Theoretic Solutions and Applications to Security.” Conitzer, V. In Proceedings of the 26th National Conference on Artificial Intelligence (AAAI-12), Toronto, ON, Canada, 2011.

CSI-House teams could make better medical diagnoses

By Ashley Yeager

Comparing a child's DNA to his parents' could help with identification of hard-to-diagnose genetic diseases. Credit: Henrik Jonsson/iStockphoto

Dr. Gregory House, star of House, M.D., and the lab techs on CSI never fail at their jobs. But that’s Hollywood. In real life, diagnosing illnesses and sequencing DNA isn’t so straightforward. It doesn’t always lead to a happy ending either, especially for children who are sick but can’t be diagnosed, even by gifted, real-life doctors.

That’s exactly why geneticist David Goldstein has teamed with pediatrician Vandana Shashi to combine a little House and CSI to identify apparent genetic diseases and quickly end some families’ diagnostic odysseys.

So far, the team has provided likely genetic diagnoses in six of 12 children it has worked with, said Goldstein at a Cardiovascular Research Center Seminar Series talk on June 27.

The children were referred to Shashi for a pilot study where she would record their symptoms, or phenotypic behavior, much like House. Then, Goldstein and his team at the Center for Human Genome Variation collected DNA samples from the children and both of their biological parents.

Using next-generation genetic sequencers, as well as traditional DNA scanners, Goldstein and his team looked for genetic variations between the children’s and parents’ complete genome. Like looking at DNA to identify a criminal, Goldstein and his genetics team are scouring the sequences for genetic fingerprints of the diseases disrupting the children’s lives.

Once variations were identified, the entire team looked for known diseases with similar gene mutations and symptoms. Goldstein explained that the study not only pinpointed the undiagnosed congenital diseases in some patients but also presented new genes that could also be linked to the illnesses. The study’s success has led to the creation of the Genome Sequencing Clinic.

The clinic will begin to help the families of the 50,000 children (out of the four million) born each year in the US with difficult-to-diagnose genetic diseases. These types of studies will likely be the “earliest drivers for large-scale genetic sequencing,” Goldstein said.

But, he cautioned, “there’s a whole lot of junk,” or variation, in DNA. Every genome has the narrative potential for devastating diseases, and that means that House-CSI teams, like Shashi and Goldstein’s, need to be extremely careful when making diagnoses, especially if the results will influence treatment, he said.

Citation: Clinical application of exome sequencing in undiagnosed genetic conditions. Need, A. et. al. 2012. J. Med Genet. 49:6 353-361. doi:10.1136/jmedgenet-2012-100819

Betting on Bayesball

By Ashley Yeager

Derek Jeter, upper left, and Alex Rodriguez, lower right, anticipate a grounder in a 2007 game . Credit: Wikimedia.

New York Yankees shortstop Derek Jeter has five golden gloves. Alex Rodriquez, a Yankees shortstop and third baseman, has three.

It wasn’t a surprise then when Sayan Mukherjee asked a crowd at Broad Street Café who was a better mid-fielder and Jeter got a few more cheers.

The question, and response, prompted Mukherjee, a statistician who studies machine learning, to launch into a discussion about intuition and statistics in sports, specifically in baseball. Mukherjee spoke on June 12 as part of Periodic Tables: Durham’s Science Café.

He admitted he was a Yankees fan, which elicited some booing. Laughing it off, he then showed a complex statistical equation his colleague, Shane Jensen at the University of Pennsylvania, and others use to calculate a player’s success at fielding ground and fly balls.

On the next slide, Mukherjee showed the results. Rodriquez was clearly on top, and Jeter closer to the bottom. “Jeter doesn’t have as big a range as other players, that’s all I’m suggesting,” Mukherjee said.

Of course, these statistics, called sabermetrics, aren’t new to Jeter and other players. The numbers, based on Bayesian statistics, are exactly what the Oakland A’s baseball team used in 2002 to build a winning team. And, when new numbers came out in 2008, the stats ranked Jeter fairly low as a defensive player. He responded by saying there was a “bug” in the model.

“He has a point. The exact conditions for each play are not the same, so it’s hard to truly compare them,” Mukherjee said. The equation, however, is a way to measure factors of the game, rather than rely on intuition, and statisticians are trying to add more factors to make the model more realistic. The next factor they want to add will account for the different designs of ballparks, Mukherjee said.

He added, though, that these stats don’t really put players’ jobs at jeopardy. Judging by the crowd’s first response, people obviously still rely on intuition when it comes to picking their favorite players. The cold, hard numbers therefore affect how players approach their game – ie Jeter’s post-2007 season focus on a training program to combat the effects of age, Mukherjee said.

The data also affect people betting on the games. “Betting is huge, in any sport,” Mukherjee said, and the numbers, it seems, can affect how people choose to risk their money, but not their team loyalty.

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