Eye Study Is a Small but Crucial Advance for Stem-Cell Therapy

Safety first: Robert Lanza, chief scientific officer of Advanced Cell Technology, says the two patients in an early stage of a stem-cell study have shown no negative side effects from the treatment.
Advanced Cell Technology

BIOMEDICINE

The results show that the treatment can be safe, but whether it can be effective is another question.

• BY KAREN WEINTRAUB

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The first published clinical trial of stem-cell therapy is a tremendous boon to the company leading the experiment—but it's only a small step forward for the field.

In a paper published this week in The Lancet, scientists from the David Geffen School of Medicine at the University of California, Los Angeles, and from Advanced Cell Technology, in Marlborough, Massachusetts, reported that two patients each safely received injections of embryonic stem cells into an eye.

Stem-cell research in patients suffered a major blow recently, when one leading company,Geron, pulled out of a pioneering spinal cord repair study. The new study is more limited in scope, focusing on treatment that is easier to study and less problematic.  

The new study was written three months after treating the patients, both of whom have degenerative eye diseases and limited sight. Another three months has now passed, andRobert Lanza, chief scientific officer of Advanced Cell Technology, says both are still doing well, with no apparent side effects.

Lanza says Advanced Cell Technology would not commercialize the work itself, but would look to partner with a company that would.

The intent of the study was to show that the treatment is safe, not to look at its effectiveness. But Lanza, the paper, and a related commentary also published in The Lancet all cited the women's reports of benefits from the procedure. One woman's vision improved enough to see a hand waved in front of her face; the other climbed from 20/500 to 20/320 on an eye chart.

Kevin Eggan, an associate professor of stem cell and regenerative biology at Harvard University, says he's surprised that The Lancetpublished such preliminary results, and that scientists are talking about the treatment's effectiveness at such an early stage of research.

"I wouldn't say the data is super convincing that these cells are doing much," says Eggan, also a principal investigator with the Harvard Stem Cell Institute. Only two patients were studied, and in one of the patients, the cells appeared to have had no biological effect, despite her report of improvement. "For myself, I would have felt a lot more comfortable if I had several people telling the same story."

This research is important, Eggan says, because it shows that at least some patients can safely receive cells derived from human embryonic stem cells. The implanted cells did not grow uncontrollably and did not trigger development of a teratoma—a benign tumor that contains other bodily tissues. "The cells are there, they're surviving, and they're persisting. They're not growing out of control, and they're not growing a teratoma."

In the study, human embryonic stem cells were coaxed into becoming retinal pigment epithelium, or RPE cells. They were carefully examined for impurities or potential dangers, and then injected into one eye in each patient. The two received 50,000 RPE cells each. The next round of patients will receive 100,000 RPE cells, and later patients in the trial will be given 200,000 cells each.

Of the 24 people in the trial, half have dry, age-related macular degeneration—the most common cause of vision loss in older Americans—and half have Stargardt macular dystrophy, a far rarer disorder that strikes children and teenagers. There are no effective medical treatments for either condition. Lanza says the company will soon begin another round of research in the U.K. involving 24 patients with the same conditions.

The therapy is aimed at preventing loss of photoreceptors in the eye. Because the trial patients have already lost most of their receptors, they are less likely to benefit than people who have retained more vision, Lanza says.

The eye is a logical organ for testing stem-cell therapies because it is immunoprivileged, meaning it is unlikely to mount an immune response to foreign cells. The eye is also easy to see into, to check for progress and problems.

Ellen Feigal, senior vice president of research and development for the California Institute of Regenerative Medicine, describes the new study as "good for the field."

"It's a very good initial step in the process to evaluate a therapy for its safety and effectiveness," she says.

New electron interactions observed

THE UNIVERSITY OF NEW SOUTH WALES

Scientists have spotted electrons interacting in new ways at the quantum level. Image: alengo/iStockphoto Physicists at the University of New South Wales have observed a new kind of interaction that can arise between electrons in a single-atom silicon transistor. The findings, published this week in the journalPhysical Review Letters, offer a more complete understanding of the mechanisms for electron transport in nanostructures at the atomic level. The study is already available on arXiv.  “We have been able to study some of the most complicated transport mechanisms that can arise up to the single atom level,” says lead author Dr Giuseppe C. Tettamanzi, from the School of Physics at UNSW. The results indicate that quantum electronics could be driven by the orbital nature of electrons, and not just the spin or the charge as was previously thought, he says, which opens the door for a new type of electronics to be explored. The study, in collaboration with scientists from the ICMM in Madrid and the Kavli Institute in The Netherlands, describes how a single electron bound to a dopant atom in a silicon matrix can interact with many electrons throughout the transistor. In these geometries, electron-electron interactions can be dominated by something called the Kondo effect. Conventionally, this arises from the spin degree of freedom, which represents an angular momentum intrinsic to each electron and is always in the up or in the down state. However, researchers also observed that similar interactions could arise through the orbital degree of freedom of the electron. This describes the wave-like function of an electron and can be used to help determine an electrons’ probable location around the atom’s nucleus. Importantly, by applying a strong magnetic field, the researchers were able to tune this effect to eliminate the spin-spin interactions while preserving the orbital-orbital interactions. The Kondo effect is considered one of the most complex phenomena found in solid-state physics, says Tettamanzi. In bulk material it causes an increase in electrical resistivity – the ease of current flow – at certain temperatures. But in nanostructures, like the system studied here, it allows for the precise quantifications of electron interactions up to the single elements.  “By tuning the effect in two different symmetries of the fundamental state of the system…we have observed a symmetry crossover identical to those seen in high-energy physics,” says Tettamanzi. “In our case this crossover was observed simply by using a semiconductor device which is not too different from the transistor you use daily to send your emails.” Tettamanzi, who was recently awarded a prestigious ARC Discovery Early Career Researcher Award, will now investigate another transport mechanism that can arise in quantum dots and single atom transistors called “quantised charge pumping”. The idea here is to create a current flowing through a nanostructure without applying a voltage between the leads, but by applying varying potentials at one or more gates of the transistor, in an apparent violation of Ohm’s law. Editor's Note: Original news release can be found here.

Native trees store carbon longer

JOSHUA RAMPLING, SCIENCENETWORK WA

Many carbon sequestration programs use just one type of non-native tree, but may not be long-lasting and could miss out on biodiversity benefits. Image: AdirondackZack/iStockphoto New research into the carbon sequestration abilities of native tree species was undertaken by Greening Australia, and will hopefully make native species more attractive and viable option for carbon farming. Prior to the study there had been little research into the levels of carbon which local non-timber species of trees are able to sequester carbon, and most large scale reforestations used non-native species of trees. Greening Australia’s Justin Jonson who co-authored the paper says the use of a single species for large scale land-use change does not offer the best long-term outcomes and focus on more than just carbon sequestration. He says monocultural reforestation for carbon capturing does not provide the secondary benefits that the use of native species is able to achieve. The use of native species to create a more natural woodland system will provide a habitat that can support local fauna and provide a range of benefits to biodiversity. Mr Jonson says native species can also provide evidence of permanence which is untested in monoculture carbon farming. Under Australia’s Carbon Farming Initiative carbon stores must be held for at least 100 years to meet the standards set. If the carbon is released back into the atmosphere before this time there are no benefits gained. “The carbon pools have to be a permanent entity, they have to be able to stand climactic and environmental conditions for up to 100 years.” Jonson says. “What is untested in these monoculture style plantations of high growth species... is that there are no plantings that go back even 50 years.” “The only thing we have certainty on, that we know can persist for more than 100 years are the natural systems that have persisted for many hundreds of years and that is why they endure.” Mr Jonson says there is a responsibility by the industry and the government to think long-term about any reforestation initiatives. “You need to think about future generations when you are talking about permanent land use change,” he says. “Whatever we put in at the beginning we are stuck with.” The study—based in the area between the Stirling Ranges and the Fitzgerald River National Parks north-east of Albany—filled a knowledge gap on the level of carbon native species sequesters. The area is part of a large conservation initiative called the Gondwana Link which is trying to reconnect the remaining fragmented native bushland in the South of Western Australia. Editor's Note: Original news release can be found here.

Flight building

Journey Through Human Organs

shirdi wale Sai Baba

New Magnetic Soap Could Clean Oil Spills With No Suds Left Behind

By Rebecca Boyle

Oil Spill Cleanup Sea turtle experts clean a small Kemp's ridley turtle with a toothbrush in June 2010, during the Deepwater Horizon oil spill. A new magnetic soap could be used to clean animals after a spill, and can be recovered using a magnet so that none of the detergents remain in the environment.Deepwater Horizon Response via Flickr

A newly designed metallic soap reacts to a magnetic field, a first in soap research that could lead to better control of cleanup chemicals in situations like aquatic oil spills. A magnet can overcome both gravity and the surface tension between water and oil to draw the soap away, ensuring it can be recovered after it’s used.

One of the main concerns in cleaning up oil spills (and other industrial waste) is the addition of new chemicals into the environment. Dispersants and surfactants — the technical word for soap — can also harm plants and animals, so researchers have long been looking for easy ways to retrieve them or break them down. Some soaps respond to changes in pH, others may break down in sunlight, and so on.

For the first time, scientists have developed a magnetic one, which can conceivably be hoovered up with a magnet after it’s done cleaning. It is made of iron-rich salts that dissolve in water and a host of other inert soapy solutions, the same types found in mouthwash or fabric softener, according to the University of Bristol. The iron creates metallic centers inside the soap particles.

Led by Bristol professor Julian Eastoe, the team tested their soap by placing it in a test tube and pouring in a less-dense organic solvent material on top, so the soap was sandwiched at the bottom. They placed a magnet near the test tube and watched the soap levitate through the less-dense layers and reach the magnet. The team wanted to investigate how this worked, so they examined the iron soap at the Institut Laue-Langevin, a French research facility that uses a neutron beam for imaging experiments. The researchers learned that clumping soap particles brought about their magnetic properties, according to a news release from ILL.

The magnetic soap probably won’t be appearing on supermarket shelves anytime soon, but it’s an interesting breakthrough that could lead to new cleanup solutions for a wide range of industries. A paper on the soap was published in the journal Angewandte Chemie.

Magnetic Soap: A magnet attracts the soap away from other solutions, including oil and water.  Institut Laue-Langevin

[via New Scientist]

World's Most Powerful X-Ray Laser Super-Heats Aluminum Foil to 3.6 Million Degrees

Creating and observing super-hot solid plasma could lead to a greater understanding of fusion processes

By Rebecca Boyle

SLAC Chamber This photograph shows the interior of a Linac Coherent Light Source SXR experimental chamber, set up for an investigation to create and measure a form of extreme, 2-million-degree matter known as “hot, dense matter.” The central part of the frame contains the holder for the material that will be converted by the powerful LCLS laser into hot, dense matter. To the left is an XUV spectrometer and to the right is a small red laser set up for alignment and positioning. University of Oxford/Sam Vinko

In two separate studies, the world’s most powerful X-ray laser has been used to build the first atomic X-ray laser pulse, as well as to superheat and control a clump of 2-million-degree matter. The atomic laser could be used to watch biological molecules at work, while the creation of hot dense matter could be used to understand the processes of nuclear fusion.

Researchers at the SLAC National Accelerator Laboratory used the Linac Coherent Light Source, a rapid-fire X-ray laser, to flash-heat a small piece of aluminum foil and create a solid plasma known as hot dense matter. A team led by Sam Vinko, a postdoc at Oxford University, took the temperature of this matter — 2 million degrees Celsius, or 3.6 million degrees Fahrenheit — and the whole process took about a trillionth of a second. The measurements will lead to more accurate models of how hot dense matter forms and behaves. These models could help scientists understand — and maybe someday recreate — the process of nuclear fusion that fuels the sun, according to a news release from SLAC.

Scientists can create plasma from gases using conventional lasers, but you need a super-powerful laser to create a plasma from a solid material. The LCLS’ ultra-short wavelengths of light can penetrate a dense solid and look at it, all at the same time. The LCLS is underground in Palo Alto and covers a distance of a little more than a mile. It can create intense bursts of X-ray radiation more than a billion times brighter than any other laser source.

In a separate study, the LCLS was harnessed to build the first-ever atomic-scale X-ray laser, a feat that could open up a whole new field of atomic imaging.

Since the laser was invented more than 50 years ago, scientists have tried to lase at shorter wavelengths, but it’s difficult to do because shorter wavelengths require faster atom pumping. But free-electron lasers in the X-ray range can produce superfast pulses of intense energy, so this pumping is now feasible. Scientists from Lawrence Livermore National Laboratory used the LCLS to give a pumped-up kick to a cluster of neon atoms. This knocked some electrons up to higher energy states and created a cascade of X-ray emissions — a mini atomic-sized laser.

The atomic laser’s light is much more pure, and its pulses are much shorter, so it could be used to tease out sharp details of atomic-scale interactions and phase changes that would otherwise be impossible to see.

Both papers were published today in Nature.

Rainforest Expedition Turns Up 46 New Creatures, Including This Cowboy Frog

By Rebecca Boyle

Howdy, Cowboy Frog This frog was found in a night survey in a remote area of Suriname. Paul Ouboter/Conservation International

Scientists trekking through the Suriname rainforest, one of the last road-free wilderness areas in the world, turned up a host of animals that conservation biologists believe are new to science. This little guy was just one of them.

This khaki-colored frog has white fringes on its legs and a spur on the heel, earning it the nickname “cowboy frog.” It looks pretty similar to another tree frog, the “convict tree frog,” but it doesn’t have the convict’s black and white stripes. Scientists from Conservation International discovered the cowboy frog on a small branch during a night survey in a swampy area of the Koetari River.

A new type of spiny catfish, henceforth known as the “armored catfish,” was about to be eaten as a snack until one of the scientists noted its unusual appearance. The local guide who was about to chow down was instead told to preserve the fish as a specimen. The team found a couple other types of catfish, too.

The team also found a new species of katydid, which they nicknamed the “Crayola katydid” for its bright colors. They are the only katydids known to employ chemical defenses, according to Conservation International. There’s a shiny water beetle and some damselflies to round out the list.

Speckly Katydid: Katydids in the same genus as this one are the only katydids known to employ chemical defenses, which are effective at repelling bird and mammalian predators.  Piotr Naskrecki/Conservation International

[Conservation International via BBC]