Screening for HER2 breast cancer

There are different types of breast cancer, some much more aggressive than others. There are also a variety of treatment regiments, so identifying the type of cancer quickly and accurately is critical. To complicate matters further, tumors that develop from circulating cancer cells are not always identical to the original tumor. Until recently, it has been impossible to screen blood for elusive, migrating cancer cells. Now, Benjamin Thierry and colleagues from the University of South Australia have developed a device for screening cancer cells circulating in blood.

In particular, the researchers were looking for ways to determine whether patients were positive for HER2, a protein associated with a very aggressive type of breast cancer. If these patients are treated early enough with the HER2 blocker trastuzumab (Herceptin), their prognosis improves tremendously. However, at over $50,000/year, Herceptin is too expensive to give to every breast cancer patient, considering that only the 20 to 25% of patients who overexpress HER2 would benefit.

Traditionally, HER2 status is determined via biopsy of the primary breast tumor. As I stated, this can yield misleading results. Twenty percent of the time, secondary tumors that result from metastasis do not match the primary tumor. In order to be certain whether or not a patient will benefit form Herceptin, doctors must isolate and test all circulating cancer cells as well as the primary tumor, something that has been impossible.

To that end, Thierry and his team have developed a disposable microfluidic device that can capture cancer cells but not normal blood cells. When tested in breast cancer cell lines, the device captured about 80% of cancer cells circulating in blood samples. If the device is equally effective in human trials, it means that doctors will be much closer to knowing whether any cells in their patients’ bodies would respond to Herceptin treatment, knowledge that could save many lives.

Remembering false memories

Memory is notoriously unreliable. It’s common to clearly remember an event one way, only to discover (upon watching a replay or rereading a journal entry) that we were completely wrong. Isabel Lindner of the University of Cologne, Gerald Echterhoff of Jacobs University Bremen, Patrick Davidson of the University of Ottawa and Matthias Brand of the University of Duisburg-Essen have now added an item to the list of ways memory can be fooled. Apparently, watching other people perform an action makes people 'remember' doing it themselves.

The researchers showed a group of volunteers a video of other people performing simple actions, such as shuffling cards. In some cases, the subjects had performed that same action themselves, in others they hadn’t. When questioned two weeks later, many of the volunteers distinctly remembered doing things they had only observed. This was true even when the volunteers were primed ahead of time with the knowledge that this phenomenon could occur. The scientists called this effect ‘observation-inflation’.

This effect could be a result of the ‘mirror neuron system’. These neurons fire when an individual either performs an act, or observes another person performing that act. They are believed to be involved in empathizing with others, as they allow us to literally put ourselves in another's place. Now it appears that not only can we imagine what it would be like to perform an action upon seeing someone else do it, but we think we’re the ones who did it!

Deceptive Robots

Ronald Arkin and Alan Wagner of the Georgia Institute of Technology have successfully coached robots in the art of deception.

The engineers began working on robot deception in order to give robots an added tool in handling their various tasks. An obvious application would be for a military robot to trick enemy soldiers about troop strength or location. However, the researchers also foresee non-military uses, such as using deception to calm disaster victims while they are being rescued.

So far, the team has managed to get one robot to trick another robot into thinking it was hiding in one place, when in reality it was somewhere else. The hiding robot deliberately knocked over some markers to indicate a false trail. Needless to say, the researchers have a bit of work ahead of them before they take their deceptive robots on the road. If the picture below is indicative, even my dog could penetrate this level of duplicity. To be fair, it's still early days.

Georgia Tech Regents professor Ronald Arkin (left) and research engineer Alan Wagner with their robots. The black robot intentionally knocked down the red marker to deceive the red robot into thinking it was hiding down the left corridor. Instead, the black robot is hiding inside the box in the center pathway.

Credit: Georgia Tech Photo: Gary Meek

This line of research does open up a slew of ethical questions. Is it better to falsely reassure victims? And what do robots with the ability to deliberately deceive say about our understanding of intelligence and the theory of mind?

According to Arkin:

We have been concerned from the very beginning with the ethical implications related to the creation of robots capable of deception and we understand that there are beneficial and deleterious aspects. We strongly encourage discussion about the appropriateness of deceptive robots to determine what, if any, regulations or guidelines should constrain the development of these systems.

X-linked autism risk

Study after study has shown a genetic component for autism spectrum disorder (ASD). So far, the data hasn’t explained why boys suffer from the condition more frequently than girls. However, that may be changing. Doctors and researchers from the Centre for Addiction and Mental Health and from the Hospital for Sick Children, both in Toronto, have found a gene on the X chromosome that is associated with some types of ASD.

As I’m sure you know, girls have two X chromosomes, whereas boys have only one. This means that if a girl and a boy each inherit a mutation on one X chromosome, the girl may be able to compensate with the normal version of the gene on her other X. The boy, on the other hand, will have no choice but to express the mutant phenotype. Such traits are called ‘sex-linked’ or ‘X-linked’, and occur most often in males. Females only express sex-linked traits if they inherit the same mutation from both parents (and thus have it on both of their X chromosomes).

By comparing the gene sequences of 2000 ASD patients to that of thousands of controls, the scientists discovered that about 1% of boys with ASD carried a mutation on the PTCHDI gene located on the X chromosome. Sisters carrying the same mutation on only one of their X chromosomes were not affected. Obviously, this one mutation cannot be responsible for the overall difference in numbers between ASD-affected boys and girls. However, it may be only the first of many X-linked genes involved in ASD.

On the face of it, the fact that ASD is looking more and more like a series of genetic disorders can be discouraging. After all, there’s little that can be done to prevent a baby from inheriting these mutations. However, there is a silver lining. Because very young babies can be tested for genetic mutations, once researchers know what sequences to screen for, therapeutic treatments can begin immediately. There is evidence that early intervention is extremely beneficial in helping kids with ASD.

Image above: Chromosomes from a human female. Note the two identical X chromosomes. In males, there would be one large and one small chromosome in that position.

Physical fitness boosts kids’ brain power

It’s no surprise that a fit body is important for a fit mind. Art Kramer and Laura Chaddock led a team of scientists from the University of Illinois in determining just how the two connect. For nine and ten year old kids, it’s through the hippocampus.

The hippocampus is a paired structure within the brain that is involved in both spatial navigation and long-term memory. Studies done on either animals or older humans have shown that exercise can increase the size of the hippocampus. The University of Illinois wanted to see whether the same was true for children, and whether such a difference would translate to increased brain power.

To begin with, the researchers had a bunch of nine and ten year old children run on a treadmill, and measured their oxygen usage. More fit individuals at any age will use oxygen more efficiently. They next had MRIs taken of the kids’ brains, specifically measuring the size of their hippocampuses. Finally, they had the kids take some memory tests.

The physically fit children had hippocampuses that were up to 12% larger in volume than the sedentary kids, and also did better on the memory tests. This suggests that rather than cutting physical education to make room in the budget and time schedule for more academics, schools should make every effort to increase opportunities for improving student fitness.

Super sensitive artificial skin

Stanford researchers led by Zhenan Bao have developed an artificial skin that can detect the slightest changes in pressure. The material was successful in registering the weight of small insects.

Previous attempts to make artificial skin were often done with very thin, continuous sheets of rubber or film. Sensors using this type of skin could not be made sensitive enough to detect tiny changes in weight. The innovation of the Stanford team was to craft a thin elastic rubber sheet into a grid of miniscule pyramids, up to 25 million per square centimeter, sandwiched between electrodes. The slightest change in pressure resulted in the compression and re-expansion of the tiny pyramids, which altered the electric flow and could be detected by sensors. By altering the shape of the pyramids, the scientists were able to change the range of sensitivity.

Caption: The sensor is sensitive enough to easily detect this butterfly positioned on a sheet of the sensors.

Credit: Linda Cicero, Stanford University News Service

So far, the team has created a patch of ‘skin’ about seven centimeters across. It mimics both the pressure sensitivity and the response rate of human skin. In addition, it appears to be flexible enough to be used as a covering for a variety of surfaces.

Needless to say, there are myriad uses for such exquisitely sensitive artificial skin. Besides the obvious usage in prosthetics, the pressure sensitive system could also revolutionize robotic surgeries, create pressure-sensitive bandages, help athletes improve their grips…you name it!

Just for fun: Crazy Libration Orbits

NASA has successfully sent a satellite (ARTEMIS-P1) into an 'Earth-Moon libration orbit'. This means that the satellite does not orbit either Earth or the moon, but instead orbits two of the five Earth-moon Lagrangian points (regions of space where a satellite can remain stationary with respect to two large bodies). Needless to say, this 'orbit' requires close monitoring and maintenance from the ground.

Illustrations of Artemis-P1 libration orbits.

Credit: NASA/Goddard.

Engulfing companion star leads to stellar youthful look

Astronomers can usually distinguish young from old stars in a number of ways. Joel Kastner of the Rochester Institute of Technology (RIT) led a team of cosmologists from RIT, UCLA, Berkelely, Observatoire Astronomique de Strasbourg and Laboratoire d’Astrophysique de Grenoble in uncovering a case of misleading stellar advertising.

The star in question, BP Piscium (BP Psc), has at least a couple of the hallmarks of youth. It is orbited by a disk of gas and dust that could one day coalesce into planets and moons, and it is ejecting powerful jets of material from its poles. Both of these attributes normally belong only to very young stars.

On the other hand, there were a few anomalies that made the astronomers say, ‘hmmm’. For one thing, BP Psc is giving off orders of magnitude fewer X-rays than should be expected. Rather than up to a few thousand per day, the Chandra X-ray Observatory only counted 18. That’s normal for an older star, not a young one. Among the other oddities were the facts that BP Psc is not located among other young stars, and that there isn’t enough lithium on its surface.

After much observation, the astronomers have a working hypothesis to explain BP Psc’s youthful appearance. They propose that BP Psc is actually a billion-year old star in its ‘red giant stage’, the stage at which stars of a certain size run out of fuel and expand tremendously. The sun is expected to undergo this expansion in about 5 billion years, at which point it will extend up to the current orbit of the Earth. In the course of expanding, BP Psc engulfed any planets it might have had, plus at least one companion star. That swallowed star resulted in both the disk of material surrounding BP Psc and the several light year long jets spouting from its poles.

One interesting possible result would be the formation of young planets around an old star. It had been thought that planet formation could only occur during the early stages of stellar evolution, when the disk of gas and dust surrounding the baby star starts to coalesce. However, Grandpa BP Psc also has such an orbiting disk and could potentially have a second family of planets to replace any that were engulfed.

Left: The composite image shows X-ray and optical data for BP Piscium (BP Psc). Chandra X-ray Observatory data are colored in purple, and optical data from the 3-meter Shane telescope at Lick Observatory are shown in orange, green and blue.

Right: An artists’s impression of a close-up view. For clarity a narrow jet is shown, but the actual jet is probably much wider, extending across the inner regions of the disk.

Credit: X-ray: NASA/CXC/RIT/J. Kastner et al. Optical: UCO/Lick/STScI/M. Perrin et al. Illustration: CXC/M. Weiss

New weapon against MRSA: insect brains

Simon Lee and others from the University of Nottingham have identified molecules in the brains of cockroaches and locusts that can kill drug resistant bacteria, such as MRSA.

MRSA, which stands for either methicillin-resistant or multidrug-resistant Staphylococcus aureus, is a huge problem, particularly in hospitals. As the name implies, the bacteria are partially or entirely immune to almost all known antibiotics, and thus are very difficult to kill. Lee and his team tried the novel approach of exposing the bacteria to insect brains.

More specifically, the researchers first identified some novel molecules within the insect tissues, and then determined their toxicity to both MRSA and to Escherichia coli. They found that the new compounds killed 90% of the bacteria, all without harming human cells. More studies are being done to understand exactly how this works. The scientists are hopeful that the insect brain components can lead to a new line of defense against bacterial invaders.

Interestingly, this isn’t the first insect product to fight MRSA. I previously wrote a post about the antibacterial properties of bee glue.

Visualizing water molecules

Model of graphene

If you look extremely closely, there’s a coating of water a few molecules thick on most surfaces. Although scientists know the water is there, it has been extremely difficult to see the water, not only because it’s in microscopically thin layers, but also because the water tends to slide around. Ke Xu, Peigen Cao and James Heath of Caltech have devised a novel way of trapping and examining the surface water.

Originally, the team was simply studying graphene (a one-atom-thick carbon lattice) layered onto atomically flat surfaces (mica). When they noticed nanoscale structures that grew in prevalence under high humidity and disappeared under completely dry conditions, they realized they’d found a way to visualize the thinnest layers of water.

The graphene lies down so tightly over the flat surface of the mica that any anomalies, such as water molecules, are essentially shrink-wrapped and become visible under an atomic force microscope.

To their surprise, the researchers found that as the humidity increased, the first layer of water deposited was a two-molecule thick layer of ice. This was true even at room temperature. On top of that, a second two-molecule thick layer of ice was deposited. Only on top of that would you finally get liquid droplets of water, if the humidity were high enough.

The scientists hope to use their method to look at proteins and other larger molecules.

Atomic force micrograph of ~1 micrometer wide x 1.5 micrometers (millionths of a meter) tall area. The ice crystals (lightest blue) are 0.37 nanometers (billionths of a meter) high, which is the height of a 2-water molecule thick ice crystal. Detailed analysis of such images reveals that this first layer of water is ice, even at room temperature. At high humidity levels, a second layer of water will coat the first layer, also as ice. At very high humidity levels, additional layers of water will coat the surface as droplets.

Credit: Heath group/Caltech

Transcontinental anesthesia

The world’s first example of transcontinental patient treatment was achieved last month. Thomas Hemmerling and his team from McGill University, Montreal, collaborated with Cedrick Zaouter and his team from Pisa University in remotely treating patients in Pisa.

Each patient's room contains four cameras that track vital signs. At a remote computer station called the ‘anesthesia cockpit’, doctors monitor and control the patient’s anesthesia levels. The process can be overridden at any time by doctors on the scene.

Caption: This anesthesia cockpit in Montreal is controlling anesthesia in Pisa.

Credit: Dept. of Anesthesia, McGill University

Although most people would prefer to have their anesthesiologist in the room with them personally checking their vital signs, not everyone lives in an area where such specialists are accessible. Once this system gets perfected, small rural hospitals will be able to offer a much wider range of services.

Just for fun: Oldest living things on Earth

Rachel Sussman is an artist who has made it her life’s mission to photograph the oldest living things on Earth. To that end, she has traveled all around the world, categorizing organisms that have lived for over 2000 years.

Here’s an example of her work: a 2000 year old sunland baobab tree from Limpopo Province, South Africa.

You can view the rest of her portfolio, read her blog, or see a map showing where she found the various organisms. Better yet, watch her TED talk, below.

Face blindness

Face blindness, or prosopagnosia, can be the result of a brain injury or can be present from birth (developmental prosopagnosia, or DP). In extreme cases, patients cannot recognize loved ones or people they see every day. People with this condition cannot store a 3D map of a person’s face. Thus, every slight change in position makes a face appear to be of a completely different person.

Yunjo Lee and Hugh Wilson of York University plus Bradley Duchaine from University College London and Ken Nakayama from Harvard University studied a family with DP. They found that although the subjects could read facial expressions, and one member was even an artist with the ability to render detailed sculptured faces, they had great difficulty in recognizing the same face under different lighting conditions.

Sufferers of prosopagnosia often develop coping mechanisms, such as pretending to recognize people. They also latch onto distinctive features, such as long red hair, and hope the person doesn’t change those attributes.

One of the most famous sufferers of prosopagnosia is the neurologist Oliver Sacks, who wrote Awakenings, and The Man who mistook his wife for a hat. You can hear him and artist Chuck Close, who also has the condition, discuss living with prosopagnosia on this episode of Radiolab.

Just for fun: Turkish demolition

This demolition of an 80-year-old flour mill in Cankiri, central Turkey, took place about a year ago. It was supposed to be a controlled demolition, meaning that the building was expected to collapse down upon itself. Not so much. Luckily, no one was hurt.

Hat tip: The Young Turks.

Global isotope shortage

At a recent National Meeting of the American Chemical Society, Robert Archer of the National Isotope Development Center led a team of scientists in identifying a global isotope shortage. This is already having implications in the medical community and beyond.

Isotopes are chemical elements with varying numbers of neutrons. For example, carbon has an atomic number of 6, meaning it normally has 6 protons and 6 neutrons. This type of carbon is known as carbon-12. However, carbon atoms can have 7 or even 8 neutrons (carbon-13 and carbon-14 respectively). Among those isotopes, carbon-14 is radioactive, meaning that it decays in a specific amount of time, whereas carbon-12 and carbon-13 are stable and will not decay.

Radioactive isotopes (radioisotopes) are particularly useful in medicine. They are used to both diagnose and treat a variety of illnesses, most notably cancer. In particular, eight out of ten procedures rely on one specific radioisotope: technetium-99m. This element has a half-life of only six hours. This means that in six hours, half the radioactivity that was injected into the body is gone. In twelve hours, 75% is gone, and in 48 hours there is less than 1% remaining. In other words, all traces of radioactivity are quickly cleared from the body.

One consequence of its short half-life is that technetium-99m can’t be stockpiled but must be constantly manufactured and rushed to waiting hospitals. Unfortunately, the main production site for technetium-99m and other important radioisotopes is the Chalk River facility in Ontario Canada, a facility that has been shut down since 2009.

Researchers are hoping that Chalk River will reopen soon, but in the meantime, doctors have been scrambling to come up with other, often less than ideal, treatments for their patients. The shortage has also called attention to the fact that less than 15% of the isotopes used in U.S. hospitals are produced domestically.

Uncooperative bacteria lessen infection severity

Staphylococcus aureus bioflim on the surface of a catheter

Normally benign bacteria, such as Staphylococcus aureus, which ordinarily live peaceably on our skin, can become deadly due to a process known as ‘quorum sensing’. Researchers led by Steve Diggle of the Centre for Biomolecular Sciences have discovered that when bacteria opt out of quorum sensing, infection severity is decreased.

Bacteria (and some other organisms) use quorum sensing to coordinate their activities. In the case of bacteria, the main repercussions are that the bacteria can now converge into biofilms, and can now produce toxins. The biofilms are exceedingly difficult to kill and are the bane of hospitals around the world. The toxins, well, you can imagine how damaging they can be. Think ‘flesh-eating bacteria’.

It turns out that limiting oneself to a particular position within a biofilm framework and expending the energy to make toxins isn’t necessarily the best strategy for a young bacteria making its way in the world. For this reason, a few S. aureus bacteria don’t participate in quorum sensing. Because these bacteria don’t produce biologically costly toxins, they can concentrate their resources on replicating themselves. In short, the non-quorum sensing bacteria quickly out-compete their toxin-producing brethren. This leads to an overall reduction in disease severity.

The researchers hope they can turn this competition to their advantage in fighting infection. If doctors can encourage bacteria to be less cooperative, there would be fewer deadly effects of infection.

For trauma, advantage—female

It’s well established that females recover more easily from traumatic injury than do males. Ed Childs led a team of scientists from Texas A& M in discovering why. Their work on rats showed that it’s estrogen that makes the difference.

Trauma (a physical assault on the body) can lead to extreme blood loss. This in turn, can result in hemorrhagic shock, a condition in which there is not enough blood to service all the body tissues. It is often associated with vascular hyperpermeability, in essence, an increased leakiness of blood out of blood vessel walls. The next step is often death.

Estrogen appears to prevent vascular hyperpermeability, probably due to effects on the cells mitochondria. Female rats have estrogen receptors on their mitochondria, but males do not. When those receptors were blocked, females faired no better than males in recovering from blood loss.

Photo Attribution : © Glenn Francis, www.PacificProDigital.com

Edible clothing

Kingston University student Emily Crane has taken fashion design to a new level with her edible creations. She does much of her work in a freezer, experimenting with types of gelatin, seaweed and food dyes. She has collaborated with both chemists and chefs in concocting new kinds of edible fabric.

One of her earlier works was a bubble dress, shown below modeled by her sister. Yes, it’s made of bubbles. That dress lasted only seven minutes before melting. Not something to wear to a party.

Felicity Crane in the bubble dress.

Credit: Kingston University

Her later attempts to grow food into clothing have been more permanent. Eventually, Crane hopes to design and sell clothing growing kits. As she says,

People would be able to buy packs which would include everything they need to cultivate their own uniquely tailored outfits.

Depending on the type of party, guests could even eat their outfits. Though that might not catch on. I suspect that the clothing, while technically edible, wouldn’t necessarily be particularly tasty.

If you happen to be in town during London Fashion Week (starting Friday Sept. 17^th) you can see her work on display.

Monkeypox resurges in the Congo

Human monkeypox is caused by a virus related to the smallpox virus. In fact, the two viruses are so similar that vaccination against smallpox virus also protects against monkeypox. However, there haven’t been any routine smallpox vaccinations since 1980, and in that time, monkeypox has resurged with a vengeance.

Anne Rimoin of UCLA and an international team of doctors and scientists have been tracking the rate of monkeypox infection in the Democratic Republic of Congo. They compared data gathered between 2006/2007 with data from 1981 to 1986, just after smallpox vaccination ceased. They found a 20-fold increase in human monkeypox in the region.

There have also been a few cases of monkeypox in the US, most notably in 2003, when 93 people were infected from domestic prairie dogs (none died). I should point out here, that despite the name, monkeypox is not exclusively a primate virus. It just happened to be first identified in laboratory monkeys. It actually spreads even more readily through rodents, which makes it a greater danger in most parts of the world.

Although monkeypox is generally milder than smallpox was, it does have a fatality rate of somewhere between 1 and 10%. In comparison, over 80% of infected children died of smallpox, and up to 60% of infected adults.

Rimoin and her colleagues believe that the poor infrastructure within the Congo concealed the increase of monkeypox there. That doesn’t bode well for preventing the disease from spreading to the rest of the world, especially since populations are unlikely to resume smallpox vaccination.

Insect tummy rumbles

Igor Sokolov and a team of physicists from Clarkson University have used atomic force microscopy to listen to the inside of insects.

Atomic force microscopy (AFM), also known as scanning force microscopy, permits the visualization of objects 1000 times smaller than light microscopes. In essence, the AFM consists of a tiny probe that feels its way across the surface of the object to be displayed. The surface contours are fed to a detector and then translated into an image. The same technique can be used to pick up extremely high frequency sounds.

The Clarkson team placed an AFM probe on the exoskeleton of various insects and recorded the sounds of their internal organs. The recordings were made at up to 1000 hertz (cycles per second), far greater than the previous attempts (5 hertz) to listen in to insects.

Rendering of a ladybug being recorded by the atomic force microscope (AFM) probe.

Credit: Image courtesy of Clarkson University.

Although the researchers claim that their work could lead to advances in insect control (and who knows, maybe it could), I think they just thought it would be cool to try the AFM on some insects.

You can listen to a few of the recordings here. The three sound files are from a mosquito, a fly and a ladybug respectively. I had to turn the sound all the way up to hear anything from the mosquito, but your ears may be better than mine.

Just for fun: Painted Greek Statues

Most people picture ancient Greek sculptures as pristine white marble. In fact, the Greeks would have considered an unpainted sculpture to be as unfinished as an unpainted canvas. Married archeologists Vinzenz Brinkmann and Ulrike Koch-Brinkmann have made it their two decade long mission to uncover and display the original Greek colors.

Here's a sample of their work:

Reconstruction created by Vinzenz Brinkmann.

Ants versus elephants

Ants are ferocious protectors of their territory. In sub-Saharan Africa, that territory is often an acacia tree of the species Acacia drepanolobium. These trees provide the ants with not only shelter, but also food in the form of sweet nectar. Not surprisingly, the ants are unwilling to allow giant herbivores, such as elephants, to consume the trees. But do ants really have a chance to defend their trees against these massive predators? According to a new study by Todd Palmer and Jacob Goheen from the Universities of Florida, British Columbia and Wyoming, the answer is a definitive yes.

The researchers noticed that elephants were decimating certain trees, but leaving others entirely alone. The difference seemed to be whether the trees were harboring ants. Further experiments removing ants from trees confirmed that the elephants like Acacia drepanolobium just as much as any other trees, they just don’t like ants. It turns out that elephants don’t like ants crawling up the insides of their trunks. Who knew?

Elephants can do tremendous damage to ecosystems. Unchecked, they can turn entire wooded areas into grasslands. Because the elephants may be avoiding the ant-infested trees by smell, scientists hope they can develop an elephant repellant to control feeding patterns and keep the elephants out of agricultural areas.

You can see Todd Palmer explaining his research in the video here.

Above: A Whistling Thorn (Acacia drepanolobium) with ant-containing galls.

Photo by Nevit Dilmen, Tanzania, 8 August 2010.