Moving one step at a time, has potential applications in molecular computing

A molecule has been designed to move in a straight line on a flat surface by closely mimicking human walking. The "nano-walker" could allow massive storage of information on a tiny chip, say its creators at UC Riverside. It also, they say, demonstrates that concepts from the macroscale world we inhabit can be duplicated at the scale of atoms and molecules.

The research, led by Ludwig Bartels, will be published in next month's issue of Physical Review Letters.

A UC Riverside news release reports:

The molecule—9,10-dithioanthracene or "DTA"—has two linkers that act as feet. Obtaining its energy from heat supplied to it, the molecule moves such that only one of the linkers is lifted from the surface; the remaining linker guides the motion of the molecule and keeps it on course. Alternating the motions of its two "feet," DTA is able to walk in a straight line without the assistance of nano-rails or nano-grooves for guidance.

"Similar to a human walking, where one foot is kept on the ground while the other moves forward and propels the body, our molecule always has one linker on the surface it is on, which prevents the molecule from stumbling to the side or veering off course," said Bartels, assistant professor of chemistry and a member of UCR's Center for Nanoscale Science and Engineering. "In tests, DTA took more than 10,000 steps without losing its balance once. Our work proves that molecules can be designed deliberately to perform certain dynamic tasks on surfaces."

Bartels explained that, ordinarily, molecules move in every unpredictable direction when supplied with thermal energy. "DTA only moves along one line, however, and retains this property even if pushed or pulled aside with a fine probe." Bartels said. "This offers an easy realization of a concept for molecular computing proposed by IBM in the 1990s, in which every number is encoded by the position of molecules along a line similar to an abacus, but about 10 million times smaller. IBM abandoned this concept, partly because there was no way to manufacture the bars of the abacus at molecule-sized spacing.

"DTA does not need any bars to move in a straight line and, hence, would allow a much simpler way of creating such molecular memory, which would be more than 1000 times more compact than current devices."

The research team is now trying to build a molecular ratchet that could convert random thermal oscillation into directed motion.

source: bh

Nanowires detect cancer molecules

Atomic configurations of silicon nanowires created through assembly of silicon clusters, and connected to aluminum electrodes.

Could pinpoint type of cancer even with just one hundred-billionth of the protein in a drop of blood Molecular markers indicating cancer in the body can be detected by arrays of silicon nanowires, according to Harvard University researchers. The researchers say that the special nanowires can even detect cancer markers when they constitute just one hundred-billionth of the protein in a drop of blood.

Reporting in the journal Nature Biotechnology (read abstract), the researchers say that the nanowires could also pinpoint the type of cancer present with a speed not currently available.

"This is one of the first applications of nanotechnology to healthcare and offers a clinical technique that is significantly better than what exists today," says researcher Charles Lieber. "A nanowire array can test a mere pinprick of blood in just minutes, providing a nearly instantaneous scan for many different cancer markers. It's a device that could open up substantial new possibilities in the diagnosis of cancer and other complex diseases."

According to a Harvard news release:

Lieber and colleagues linked slender nanowires conducting a small current with antibody receptors for certain cancer markers—such as prostate specific antigen (PSA), PSA-a1-antichymotrypsin, carcinoembryonic antigen and mucin-1. When these telltale proteins come into contact with a receptor, it sparks a momentary change in conductance that gives a clear indication of the marker's presence. The detectors differentiate among various cancer markers both through the specific receptors used to snag them and because each binds its receptor for a characteristic length of time before dislodging.

"Our results show that these devices are able to distinguish among molecules with near-perfect selectivity," Lieber says, adding that the risk of false readings is minimized by the incorporation of various control nanowires.

The scientists also fitted some nanowires in the arrays with nucleic acid receptors for telomerase, an enzyme inactive in most of the body's somatic cells but active in at least 80 percent of known human cancers. In testing of extracts from as few as 10 tumor cells, these receptors allowed real-time monitoring of telomerase binding and activity.

source: morover

Parkinson's gene therapy shows success in humans

First study to use a viral vector for treating adult neurological disease

A gene therapy for Parkinson's disease has shown promise in early stage clinical trials. According to treatment developer Neurologix, Inc., the 12-patient Phase I trial is the world's first study to use a viral vector for the treatment of an adult neurological disease.

A Neurologix news release reports:

[T]he vector was injected into a specific target site in the brain in order to transfer a gene to treat Parkinson's disease. The gene encodes glutamic acid decarboxylase (GAD), an enzyme which synthesizes the major inhibitory neurotransmitter in the brain, (gamma)-aminobutyric acid (GABA).

Under the FDA-sanctioned trial protocol, patients with advanced Parkinson's disease received unilateral (one side of the brain) infusion of AAV-GAD via a hair-thin catheter into the subthalamic nucleus (STN), a deep brain structure known to function abnormally in Parkinson's patients. According to the interim findings, Neurologix's STN AAV-GAD treatment appears to be safe and well-tolerated in advanced Parkinson's disease, with no evidence of adverse effects or immunologic reaction related to the study treatment. Furthermore, patients in the trial, at one year, exhibited a statistically significant improvement (27%, p = .04) in motor function on the side of their body correlating to the treated part of the brain, as measured by the Unified Parkinson Disease Rating Scale (UPDRS). In contrast, the untreated side evidenced no significant improvement in the UPDRS score. Also, activities of daily living (ADL), another standard measure of Parkinson's severity which is recorded by the patients themselves, showed a strong trend toward statistical improvement (p= .06).

In addition, fluorodeoxyglucose (FDG)-PET scans at one year revealed that the treated side of the brain exhibited a statistically significant decrease in abnormal metabolism, while the untreated side showed a further increase in abnormal metabolism. The imaging results were considered similar to those achieved with STN Deep Brain Stimulation, an FDA-approved treatment which currently represents the preferred surgical approach for advanced Parkinson's disease. This data provides solid biological support for the observed clinical improvements.

The research was presented at the 19th Annual Symposia on the Etiology, Pathogenesis and Treatment of Parkinson's Disease and Other Movement Disorders.

In a statement, Neurologix cofounders Michael G. Kaplitt and Matthew J. During commented: "While the primary objective of any Phase I trial is to demonstrate safety, the FDA's requirement of unilateral infusion of AAV-GAD allowed us the unique opportunity to compare treated and untreated sides of the brain. In essence, the untreated side acted as a control. The combined clinical and imaging data provide powerful evidence that this treatment appears to be efficacious, as well as safe, at the current dose levels."

Pending final results from the Phase I study, Neurologix plans to submit to the FDA a pivotal trial protocol for using the treatment approach for Parkinson's.

source : betterhuman

Human genes create Down's syndrome mice

Nearly complete chromosome introduced to produce most successful disease model yet Scientists have introduced most of a human chromosome into mice to produce the most successful model yet of Down's syndrome. The researchers say their work—published in Science—could aid studies into Down's and other chromosomal diseases.

Previously, it has only been possible to place chromosome fragments into mouse cells, according to a BBC News report.

Led by Victor Tybulewicz at the National Institute for Medical Research and Elizabeth Fisher from the Institute of Neurology at University College London, the UK researchers have now added about 90% of the 250 genes on human chromosome 21 into mice.

They introduced the genes into mouse embryonic stem cells.

They then used the cells to create a strain of mice carrying the extra human chromosome.

The mice have problems with memory, brain function and heart formation similar to those of people with Down's syndrome.

Researchers can now work with the mouse model to better understand Down's, such as by removing genes to see which are responsible for particular aspects of the disease.

source: betterhumans

Stem cells may repair spinal cord injury

Stem cells may repair spinal cord injury

Injections of human stem cells seem to directly repair some of the damage caused by spinal cord injury, according to research that helped partially paralyzed mice walk again. The researchers of the University of California, Irvine simulated common spinal cord injuries in mice by bruising their backbones at a specific point." Immediately after the injury, nerve cells inside die and others lose their ability to pass on signals," explained lead researcher Aileen Anderson. And then they used stem cells taken from the neural tissue of aborted foetuses. When injected into the body, they can develop into any type of nervous tissue. "The actual cells that we transplanted, the human cells, are the ones that are making myelin," said Prof Anderson, "We're extremely excited about these cells."

In tests, half of the 68 mice used were injected with around 75,000 stem cells above and below the injury site. The animals' behaviour was then assessed over the next few months.

"Animals that didn't get stem cells could only walk a little, and even though they improved slightly over the first two to three weeks, they were really struggling," said Prof Anderson. "The mice that got stem cells go from stepping just occasionally to stepping all the time."

The experiment suggests that stem cells could be used to repair spinal damage in people who have suffered damaging accidents or disease, although further studies, including safety tests, are needed before the treatment can go into human trials.

source: china net

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Stem cells bridge spinal cord gap

Washington - Injections of human stem cells seem to directly repair some of the damage caused by spinal cord injury, according to research that helped partially paralyzed mice walk again. The experiment, reported Monday, isn't the first to show that stem cells offer tantalizing hope for spinal cord injury - other scientists have helped mice recover, too. But the new work went an extra step, suggesting the connections that the stem cells form to help bridge the damaged spinal cord are key to recovery.

Surprisingly, they didn't just form new nerve cells. They also formed cells that create the biological insulation that nerve fibers need to communicate. A number of neurological diseases, such as multiple sclerosis, involve loss of that insulation, called myelin.

"The actual cells that we transplanted, the human cells, are the ones that are making myelin," explained lead researcher Aileen Anderson of the University of California, Irvine. "We're extremely excited about these cells."

The research is reported in Monday's issue of Proceedings of the National Academy of Sciences.

Stem cells are building blocks that turn into different types of tissue. Embryonic stem cells in particular have made headlines recently, as scientists attempt to harness them to regenerate damaged organs or other body parts. They're essentially a blank slate, able to turn into any tissue given the right biochemical instructions.

But they're not the only type of stem cell. Dr. Anderson and colleagues used fetal neural stem cells, a type that are slightly more developed than embryonic stem cells because they're destined to make cells for the central nervous system.

The researchers injured the spinal cords of mice and nine days later injected some with the human neural stem cells.

Four months later, the treated mice could again step normally with their hind paws. Mice given no treatment or an injection with an unrelated cell showed no improvement.

The question was what sparked that improvement. Injections of stem cells might simply stimulate the body to produce some healing factor, or they might directly repair damage themselves.

So Dr. Anderson injected the animals with diphtheria toxin, which kills only human cells, not mouse cells. The improvements in walking disappeared, suggesting it was the cells themselves responsible for recovery.

"It was striking," Dr. Anderson said.

Finally, the researchers analyzed the actual mouse spinal cords to see what the human stem cells had turned into. The hope was that they would make neurons, or nerve cells, and some did.

But the bulk of the injected stem cells formed oligodendrocytes, a different type of cell that forms myelin, the insulation coating that is key for nerve fibres to transmit the electrical signals they use to communicate.

The toxin step was key to ensuring the transplanted cells themselves are functioning, and all researchers must provide such evidence because different types of stem cells almost certainly will work by different mechanisms in different tissues, said Dr. Doug Kerr, a Johns Hopkins University neurologist who is performing similar spinal cord research with embryonic stem cells.

Much more research must be done before testing stem cells in people with spinal cord injuries, cautioned Dr. Anderson. One question is how soon after an injury cells must be administered to have any effect - no one knows how nine days in a mouse's life correlates to the post-injury period for a person. Also, the mice were bred to avoid immune system destruction of the human cells, and suppressing a person's immune system because of similar transplant rejection risk poses big problems.

"The last thing we want to do is take someone who's living a productive life - if confined, we all understand that - and make them worse," said Dr. Anderson, who said the work also shows the need to study all types of stem cells. "The exciting part is the potential is there."

The research was funded by the nonprofit Christopher Reeve Foundation and the National Institutes of Health. StemCells Inc. of Palo Alto, Calif., provided the fetal-derived stem cells.

source: globeandmail

Genetic mapping to give horses a winning edge

Genetic Map

Dublin - Scientists will soon be able to furnish race horse buyers with a genetic map before they fork out millions of dollars for a young thoroughbred that may never race, a panel of eminent researchers said on Monday. Having established that The Darley Arabian, a colt imported from Syria 300 years ago, is responsible for 95 percent of the Y-chromosomes in all male thoroughbreds, scientists believe it will not be long before they can screen out equine ailments.

"When people are spending millions in a sales ring for a thoroughbred, you might want to take a look at its engine as well," said Dr Emmeline Hill of University College London, who conducts research in animal genetics. "Genetic profiling will give you an extra level of information that wasn't there before."

Technology allowing buyers to exploit performance-enhancing genetic mutations and avoid inherited diseases that have curtailed many a horse's career should become a reality within her lifetime, she added.

Research is made easier by two centuries of record keeping, the old bones of former champions and a level of inbreeding that means the world's half-a-million thoroughbreds get almost all their genes from just 28 horses.

"It is a very narrow population and this is pretty much unique," said Professor Patrick Cunningham of Trinity College Dublin, who specialises in breeding programmes for horses and other livestock.

He added that in future conditions such as pulmonary bleeding under stress could be avoided.

"People will certainly select against that," he told journalists at the British Association for the Advancement of Science festival in Dublin. "Quite a number of horses never make it to the track because they break down in training."

A 200-year-old register identifying the parentage of purebred horses, known as the Stud Book, provided a useful launch pad for research that may soon move on to studying the remains of early champions.

"We now have the tools in terms of genetic markers and genetic maps," said Professor Matthew Binns of London's Royal Veterinary College. "Now there are collections of bones of many of these ancient thoroughbreds that will enable us to get handles on some of these key animals."

But given that genes are believed to account for just one third of a horse's performance, science can only achieve so much according to Cunningham. Producing genetic duplicates of former winners, for example, would stray beyond horse-racing's stringent rules and into the realms of science fiction.

"If you cloned Northern Dancer and put him out to race, he might end up just being an also-ran," Cunningham said of the Canadian-bred Kentucky Derby winner considered to be one of the greatest studs of the 20th century.

by: Paul Hoskins
source: iol

Work on Stem Cells, DNA Research Honored

Two scientists who first identified stem cells and two others who did pioneering work in DNA research have won prestigious medical awards. The $50,000 prizes from the Albert and Mary Lasker Foundation will be presented Friday in New York. The prize for basic medical research will be shared by Ernest McCulloch and James Till of the Ontario Cancer Institute and the University of Toronto for their pioneering identification of a stem cell. Stem cells can give rise to specialized cell types, and scientists are studying them in hopes of creating tissue to treat diseases like diabetes and Parkinson's.

The work of McCulloch and Till set the stage for today's stem cell research, the Lasker foundation said. By the early 1970s, they showed clearly that a single type of bone marrow stem cell could create red cells, white cells and platelets. Their work explained the effect of bone marrow transplantation, used to treat people with leukemia or other blood cancers.

The Lasker prize for clinical medical research will be shared by two scientists from the United Kingdom, Sir Alec Jeffreys of the University of Leicester and Sir Edwin Southern of Oxford University.

Jeffreys discovered in 1984 that individuals' DNA differed in particular sites, where the chemical sequence that makes up the genetic code exhibited variable numbers of repeats. That meant a DNA sample could be linked to the person it came from, as is now well known from court cases and identification of victims of mass disasters. He also showed that people inherit the identifying signals from their parents.

Such "genetic fingerprinting ... has helped solve crimes, settle paternity and immigration disputes, establish the bases of inherited diseases, enhance transplantation biology, save endangered species, establish human origins and migrations and advance countless other beneficial endeavors," the Lasker foundation said.

Southern, in the mid 1970s, devised a now-standard lab technique that allows scientists to detect specific bits of genetic code within an organism's overall DNA. Jeffreys used it in his work, and it played a crucial role in mapping the human genome, the foundation said.

The Lasker public service award, which carries no honorarium, will be presented to Nancy Brinker, founder and president of the Susan G. Komen Breast Cancer Foundation.

She has "created one of the world's great foundations devoted to fighting breast cancer and dramatically increased public awareness about this devastating disease," the Lasker foundation said.

source: the national

Mutation Rate In A Gene On The X Chromosome Holds Promise For Testing Cancer Risk

The X-Cromosome

The study is published in the September 15 issue of Cancer Research, a journal of the American Association for Cancer Research. "The mutation rate is widely believed to be a critical factor in the development of cancer, but it has been extremely difficult to study in human cells," says Dr. Araten. "The ultimate goal of our project is to develop a test for the mutation rate. If successful, we may be able identify individuals at high risk for cancer and find ways to decrease their risk." In the new study, supported by a grant from the Doris Duke Charitable Foundation, Dr. Araten found that the chance of a mutation in the PIG-A gene each time a cell divides ranges from about 1 in 3 million to about 1 in 300,000 in cells from individuals without a genetic predisposition to cancer. Among some people with Fanconi anemia and ataxia telangiectasia, conditions involving defects in DNA repair, which predisposes them to cancer, the probability of mutations was close to 1 in 100,000 to 1 in 20,000 per cell division, according to the study.

In order to find the mutations in the PIG-A gene, Dr. Araten took advantage of some unique properties of this gene that can be exploited with an instrument called a flow cytometer, which rapidly sifts through millions of cells to identify the rare mutants. This tool uses a laser to light up antibodies attached to surface proteins on cells; PIG-A mutants lack some of these proteins and do not fluoresce.

In human cells there are two functional copies for most genes and therefore two mutations would be required to identify a rare mutant. Because each mutation is so rare, two mutations would be unlikely to occur in the same cell in a screening test, making detection nearly impossible. However, the PIG-A gene is on the X-chromosome, which is present in only one copy in male cells and there is only one functional copy in female cells. Therefore, cells with only a single mutation in PIG-A can be identified.

"The higher the mutation rate, the more quickly cells will acquire the mutations that cause cancer," says Dr. Araten. "With a test for the mutation rate, we may be able to enroll patients at high risk in screening programs to identify cancers at an early, curable stage. We may also be able to develop medications that decrease the mutation rate."

Source: New York University Medical Center and School of Medicine

Nanotech material toxicity debated

Are the materials used in nanotechnology entirely new substances? A growing number of environmentalists think so and are urging more regulation in the production and use of nanomaterials.

Nanoparticles and nanomaterials -- tiny substances measured by the millionth of a millimeter -- often display unusual properties that might someday radically improve manufacturing, energy production, electronics and medicine.

Because the potential for nanomaterials is still not entirely understood, environmentalists warn of equally unknown effects on human health and the environment.

Nanomaterials are assembled on the molecular level from known chemicals such as carbon, iron or titanium. As materials get smaller, they gain larger surfaces in relation to their mass, which can provide greater durability and flexibility. At the nanoscale level, materials also often assume properties unlike their bulk-sized counterparts -- usually inert substances can become chemical catalysts or bond with other particles in ways not previously possible.

The debate over potential health and environment risks of nanomaterials may heat up further when the Environmental Protection Agency holds a public hearing in Washington on Sept. 29 on recommendations for voluntary nanotechnology safety guidelines scheduled to take effect in 2006. A group of 17 advocacy groups -- including Greenpeace, the Natural Resources Defense Council and the Sierra Club -- say the agency's proposal for voluntary self-regulation will not provide enough protection against potentially toxic nanomaterials.

"Nanotechnology is advancing. There's no labeling, there's no tracking, no inventory -- and the government can't tell you what's in consumer products," said Jennifer Sass, senior scientist at the Natural Resources Defense Council.

New substances

According to the EPA's request for comments on its proposed voluntary regulation of nanomaterials, "some nanoscale materials are new chemical substances subject to notification requirements" under the Toxic Substances Control Act.

The agency's request for comments also stated that "other nanoscale materials are existing chemical substances that may enter commerce without notification."

The 17 public interest groups headed by the Natural Resources Defense Council say all engineered nanomaterials should be considered as new chemical substances under the Toxic Substances Control Act, because nanomaterials assume different molecular properties than related, bulk-sized materials. The EPA, the groups say, should adopt stringent evaluation standards to prevent possibly harmful nanomaterials from entering human organs and the environment.

The advocacy coalition also says nanomaterials should be considered as potentially harmful until proven otherwise -- and cites laboratory tests showing that nano-sized particles can quickly enter cell walls, lungs and the bloodstream. Nanotechnology advocates such as the President's Council of Advisors on Science and Technology believe any potential risks are outweighed by scientific advances that may provide extraordinary treatments for cancer and solutions for problems such environmental cleanup.

'Little risk'

In a May 2005 report on the state on National Nanotechnology Initiative, the presidential advisory council stated that developments in nanotechnology "pose little risk to the public or the environment."

The report notes that 4 percent -- $40 million -- of the $1 billion in federal funds earmarked for nanotechnology research will go to research on the societal and environmental effects of nanomaterials.

In the note to President Bush that accompanied the report, the authors wrote that "social concerns and risks to human health and the environment (are) being wisely acknowledged and addressed."

One of the authors of the report, Floyd Kvamme, co-chair of the council and a longtime Silicon Valley venture capitalist, believes that the rapid evolution of nanotechnology will allow potential problems to be identified quickly.

"How can you learn much about it if you don't work with it? Most advances in science have had an upside and a downside," he said. "There will be a continuing flow of knowledge. Nanotechnology will become better defined."

Stringent oversight asked

Kvamme said that stringent regulatory oversight proposed by environmentalists could interrupt advances in nanotechnology.

"When you're doing something different, government can't be looking over your shoulder," he said. Instead, Kvamme and his colleagues believe the most critical safety issues are to be found in workplaces that manufacture or research nanomaterials. Kvamme believes voluntary regulations will provide in-house health and safety officers at nanotechnology companies enough guidance to manage new and potentially toxic substances.

"You've got to be careful. We encouraged workforce issues in the report," Kvamme said. "Small particles have always been with us, like the gold filings on medieval stained-glass windows. This (nanotechnology) is chemistry to a large extent. Health officers will know what to look out for."

In addition to co-chairing the advisory council, Kvamme is an emeritus partner of the venture capital firm Kleiner Perkins Caufield & Byers, which has investments in nanotechnology companies. Health and environment advocates worry that voluntary regulation will mean different levels of conformity to safety standards through in-house environmental health officers.

Matthew Nordan, vice president of research at the nanotechnology analysis firm Lux Research, is also wary about emphasizing workplaces issues over other potential environmental problems.

"I think these folks missed a trick," said Nordan about the assumption that manufacturing environments will provide the most exposure to nanomaterials.

Nordan believes that some of the areas of potential environmental hazards suggested by advocacy groups are real problems -- but also says that not all nanomaterials have the same properties or pose similar toxic risks. Most of the particles in nanomaterials are fixed or sealed into products, which make exposure unlikely, he said.

Free nanoparticles

Rather, Nordan asserts that toxic exposure risks will come from free nanoparticles, which are not sealed into products and can easily enter the human body or other organisms.

"Mass release of free nanomaterials is not a good idea. Disposal is probably the most important issue. The fear I have is what happens 30 years from now when these products are in landfills," he said.

Flora Chow, senior chemist at the Chemical Control Division at the EPA's Office of Pollution Prevention and Toxics, agrees that there are potential risks associated with nanomaterials, but said the agency does not have enough information to provide a complete regulatory framework for nanotechnology.

"There's so many unknowns about these chemicals. We don't know about toxicity, exposure to the environment. The database for these types of materials is so thin, you really can't do modeling on this," she said.

"The EPA has a challenge here," said Nordan at Lux Research. A lack of oversight, he said, could cause liability and insurance problems as the nanotechnology industry grows.

The EPA's Chow said that industry and public advocacy groups will be given the opportunity to comment upon nanomaterial self-regulation at the Sept. 29 meeting. A follow-up meeting is scheduled Oct. 12, and industry and advocacy groups are invited to attend.

"We should get a good dialogue going," Chow said.

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Toxic or not?

Different nanomaterials carry varying degrees of potential toxic risk.

Unlikely to be toxic

-- Silicon nanowires used in applications like solar energy.

Potentially toxic

-- Nano-zinc oxide used in some sunscreens may damage skin cells.

Potentially very toxic

-- Single-walled nanotubes used to strengthen automotive components.

Source: Lux Research Inc.

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All opposed

The Environmental Protection Agency is working on voluntary guidelines for nanomaterial safety, which are slated to go into effect sometime in 2006.

A total of 17 health and environmental organizations have issued a joint statement opposing nonbinding regulation of nanomaterials. Members of this umbrella group are:

Beyond Pesticides/NCAMP, Breast Cancer Fund, Center for Environmental Health, Clean Production Action, the Endocrine Disruption Index, Environmental Health Fund, Environmental Health Project, Ecology Center, Environmental Research Foundation, ETC Group, Greenpeace, Institute for Agriculture & Trade Policy, Maryland Pesticide Network, the Natural Resources Defense Council, Rachel Carson Council Inc., Science and Environmental Health Network, ScienceCorps, Sierra Club.

Source: Chronicle research

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Practically speaking

According to the President's Council of Advisors on Science and Technology, nanomaterial-based products have a range of applications that can help the environment and human health. Some applications listed by the advisory group include:

-- New drug therapies such as drug delivery through cell walls.

-- Improved medical diagnostic devices.

-- Long-lasting rechargeable batteries.

-- Cost-effective solar cells.

-- Highly efficient water-to-hydrogen conversion.

-- Conversion of energy from thermal and chemical sources in the environment.

-- Better water purification.

Source: President's Council of Advisors on Science and Technology

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Source: SFGATE

No single gene for ageing

According to professor Thomas Kirkwood of the University of Newcastle, there is no single gene for ageing. Throughout time, Humans have used energy to get food, produce offspring and survive danger - not to repair and maintain cells. So the maintenance system in the body slowly breaks down.

This topic was of great interest at the seminar for ageing at the conference "Functional genomics and disease" taking place in Oslo, Norway. Thomas Kirkwood is the director of the internationally recognised Institute of Ageing and Health (IAH).

Developmentally it has been more important for humans to invest energy in reproduction and not in maintenance or repair of the body over time.

But genetic factors do exist. "Approximately 25 percent of how a person ages is inherited from parents," says Kirkwood. "Stress, environment, nutrition, lifestyle and immunity play an additional role. Great variation between individuals can be seen in organisms such as round worms - and in humans."

Studies of ageing also give insight into the causes of cancer, because cancer and ageing have the same background causes, thinks Vilhelm Bohr, professor at the University of Baltimore in the United States.

"Cancer is more frequent with age. We must understand the causes of ageing to be able to understand why we have cancer," points out Bohr during his presentation at the conference.

Kirkwood's paper was presented at the "Functional genomics and disease" conference - Genetics Conference, Oslo, Norway, University of Oslo and European Science Foundation (ESF)

SOURCE: Medical News

Scientists Block Viruses From Entering Cells

Participation of human defensins and cathelicidin/LL-37 in innate host defense and adaptive immunity against microbial invasion

First identified more than 20 years ago at UCLA, defensins are peptides naturally produced by the immune system to ward off viruses. However, it was unclear how defensins worked. Now UCLA and NIH scientists have discovered that a specific defensin called retrocyclin-2 (RC2) binds to carbohydrate-containing proteins in cell membranes. This mechanism erects molecular barricades that block attacking viruses from entering and infecting the cell. RC2 stops the virus in its tracks, preventing it from replicating and spreading throughout the body.

The NIH/UCLA team used human and animal cell lines to demonstrate RC2's protection against the influenza virus. The team's earlier studies suggest that RC2 offers great promise as the lead compound for new antiviral drugs to fight off HIV and herpes, as well. Unlike antibodies, however, defensins are not pathogen specific. In addition to blocking viruses, RC2 also kills several bacteria that are highly resistant to conventional antibiotics.

Authors of the study include Dr. Robert Lehrer, Distinguished Professor of Medicine at the David Geffen School of Medicine at UCLA, and Leonid Chernomordik, Ph.D., section chief of Membrane Biology, Laboratory of Cellular and Molecular Biophysics, who led the NIH team.

###
FUNDING: The National Institute of Child Health and Human Development and NIH's Intramural Research Program supported the research. The W.M. Keck Foundation established the UCLA Functional Proteomics Center, which also participated in the study.


SOURCE: ScienceDaily

A molecule expressed by nerve cells may protect against Alzheimer's disease by reducing the risk of plaque formation in the brain. In Alzheimer's disease, protein plaques in the brain accumulate. They are derived from the amyloid precursor protein (APP). It is chopped into smaller fragments including amyloid beta peptide. Amyloid beta forms plaques that destroy nerve cells.

Thomas Willnow of the Max Delbrück Center for Molecular Medicine (MDC) and colleagues have now shown that a molecule called sorLa (for "sorting protein-related receptor"), binds to APP in nerve cells and prevents its dissection into amyloid beta peptide.

They have also shown that genetically modified mice that can't produce sorLA have increased levels of amyloid beta peptide.

And in the brain of patients who died from Alzheimer's, nerve cells had not produced sorLA while the nerve cells of a control group had.

The researchers conclude that producing little or no sorLA in the brain is linked with uncontrolled production of amyloid beta peptide and a likely acceleration of onset and progression of neurodegenerative processes.

Research is now directed towards finding substances that can increase production of sorLA in the brain.

SOURCE: Proceedings of the National Academy of Sciences.

Human brain still evolving

The human brain is continuing to evolve, apparently moving towards ever-greater intelligence.

In two related papers published in the journal Science, University of Chicago researchers report that two genes linked to brain size are rapidly evolving in humans.



"Our studies indicate that the trend that is the defining characteristic of human evolution-the growth of brain size and complexity-is likely still going on," says Bruce Lahn, lead researcher for both papers and an investigator at the Howard Hughes Medical Institute. "Meanwhile, our environment and the skills we need to survive in it are changing faster then we ever imagined. I would expect the human brain, which has done well by us so far, will continue to adapt to those changes."

In evolution, some individuals first acquire a genetic mutation and then, if it confers a benefit, it spreads.

"We're seeing two examples of such a spread in progress," says Lahn. "In each case, it's a spread of a new genetic variant in a gene that controls brain size. This variant is clearly favored by natural selection."

A news release describes the research in detail:

Lahn previously showed that there was accelerated evolution in humans among numerous genes, including microcephalin and abnormal spindle-like microcephaly-associated (ASPM). Both of these genes regulate brain size and therefore "were good candidates to look for signatures of selection. We indeed found such signatures when we compared humans to other species," he said. "As a natural extension of that, we asked, could it be that selection on these genes is still ongoing in humans?"

In the two Science papers, the researchers looked at variations of microcephalin and ASPM within modern humans. They found evidence that the two genes have continued to evolve. For each gene, one class of variants has arisen recently and has been spreading rapidly because it is favored by selection.

For microcephalin, the new variant class emerged about 37,000 years ago and now shows up in about 70 percent of present-day humans. For ASPM, the new variant class arose about 5,800 years ago and now shows up in approximately 30 percent of today's humans.

These time windows are extraordinarily short in evolutionary terms, indicating that the new variants were subject to very intense selection pressure that drove up their frequencies in a very brief period of time-both well after the emergence of modern humans about 200,000 years ago. Each variant emerged around the same time as the advent of "cultural" behaviors. The microcephalin variant appears along with the emergence of such traits as art and music, religious practices and sophisticated tool-making techniques, which date back to about 50,000 years ago. The ASPM variant coincides with the oldest-known civilization, Mesopotamia, which dates back to 7000 BC.

"Microcephalin," the authors wrote in one of the papers, "has continued its trend of adaptive evolution beyond the emergence of anatomically modern humans. If selection indeed acted on a brain-related phenotype, there could be several possibilities, including brain size, cognition, personality, motor control or susceptibility to neurological/psychiatric diseases."

"The next step is to find out what biological difference imparted by this genetic difference causes selection to favor that variation over the others," Lahn said.

The study was based on surveys of more than 1,000 people representing 59 ethnic populations worldwide.

For each gene, the scientists identified a large number of different copies. One class, called haplogroup D, shows two distinct characteristics. First, they are very young and therefore nearly identical. Second, despite recent emergence they have spread rapidly.

There were also geographic differences, which may spark controversy. For haplogroup D of ASPM, the researchers found a higher frequency in Europeans and surrounding populations including North Africans, Middle Easterners and South Asians. Meanwhile, they found a lower incidence in East Asians, New World Indians and sub-Saharan Africans. For microcephalin, the researchers found that haplogroup D is more abundant in populations outside of sub-Saharan Africa.

The researchers emphasize, however, that very little is known about the impact of the variants, and they may prove to have little to do with cognition or intelligence.

Furthermore, they stress that the study looked at only two genes, and that genetic variations within a population are often almost as great as the differences between groups.

SOURCE: BetterHuman

How DHA fights Alzheimer's

Finding provides insight into developing new treatments for neurodegenerative disease

Docosahexaenoic Acid (DHA) under Polarized Light

In a report to be published in the Journal of Clinical Investigation, Nicolas Bazan and colleagues from Louisiana State University have shown a mechanism by which DHA is neuroprotective.

The researchers have shown that DHA decreases levels of pathogenic peptides called Abeta peptides while increasing the synthesis of a protective DHA-derived messenger called neuroprotectin D1 (NPD1).

NPD1 inhibits apoptosis triggered by Abeta peptides.

In a human brain with Alzheimer's, the researchers showed that DHA and NPD1 were reduced in vulnerable brain regions.

This, they say, suggests that NPD1 is a key regulator of cell survival, a finding that could provide insight into developing new treatments for neurodegenerative diseases.

Source: BetterHuman

NYU researchers discover mechanism linking color vision and cancer genes

Biologists at New York University have discovered a system by which a random choice between two distinct cellular fates in the fruit fly eye becomes firmly established. Surprisingly, the genes involved are known ’tumor suppressor genes’, i.e. genes that are inactivated in some forms of cancer due to uncontrolled cell proliferation. Because the fly eye is highly amenable to genetic analysis, these findings, published in the latest issue of Cell, could help decipher the mechanisms by which genes that control cell proliferation and cell growth are themselves regulated.

In this study, researchers from Dr. Claude Desplan’s laboratory in the Center for Developmental Genetics at NYU Biology used the fly eye to understand the mechanism that affects the choice between photoreceptors that allows color discrimination: A given color photoreceptor can randomly decide to express a blue, or a green photopigment, but expressing both would lead to sensory confusion. Therefore, a switch mechanism ensures that photoreceptors make an unambiguous decision. Interestingly, the genes involved in this switch appear to be part of a tumor suppressor pathway.

Researchers have recently uncovered processes by which groups of genes work together to affect the number and size of cells. These genes are often affected in cancers where cells proliferate in an uncontrolled manner. Less clear, however, are the upstream mechanisms that control this genetic activity: Understanding the regulation of these pathways is essential as it would enhance our ability to control processes by which cancer cells replicate or die. Although the photoreceptors have long completed their last cell division, they appear to re-utilize the genetic pathways known to control cell proliferation and cell size to achieve a stable state.

"These genes form a bistable loop that insures a robust commitment of color photoreceptors that does allow ambiguity," said Desplan, the study’s corresponding author. "This represents an unexpected role for genes known to control cell proliferation and cell growth."

SOURCE: Innovation Reports

British nanotech to revolutionise chips

Nanowires Structure

Researchers at Imperial College London, Durham University and the University of Sheffield have announced a breakthrough in computer chip design that could revolutionise the industry. The new design has computing nodes linked by nano-wires in a structure similar to neurons and axons in the human brain.

In research published in the journal Science the researchers claim that the chip will combine the storage capability of a hard drive with the low cost of memory cards, potentially increasing memory capacity by 200 times from an average of 500MB to around 100GB.

The breakthrough came when the team found they could reproduce the key functions of conventional microchips using only the 'spin' of electrons, which is responsible for magnetism, rather than the 'charge' across a transistor that traditional microchips use.

This allowed the team to build 3D 'stacked' processors, an approach lead researcher Russell Cowburn, professor of nanotechnology in Imperial's department of physics, compares to using cupboards instead of table tops for storing goods.

"Traditionally we have used electronics for microchips and magnetism for hard disk drives," he explained.

"This discovery allows us to combine these two approaches to make a new generation of 3D microchips that can store so much more information than a flat 2D surface."

The team is currently working with commercial partners to develop a new generation of computer hardware, and a spokeswoman confirmed that products should be on the market within the next few years.

SOURCE: PCW

IVF may alter gene to make children taller

In Vitro Fertilization

Children born through in vitro fertilisation grow to be four centimetres taller as adults than their naturally conceived counterparts, according to research announced yesterday. The findings, presented to the Fertility Society of Australia's annual meeting, suggest that something during the IVF process changes the way genes are expressed, making a child grow more. The results are based on a small New Zealand study that involved single IVF births, at term, that used fresh, not frozen, embryos.

The Auckland children, aged four to 10 69 IVF and 71 non-IVF produced another surprising result: the IVF children had lower levels of "bad" cholesterol and higher levels of "good" cholesterol, which meant a lower risk of heart disease in adulthood, researcher Harriet Miles said.
Tests showed the IVF children had higher levels of growth factor in their blood and were taller for their age than the controls, more so when adjusted for parental height.
Dr Miles said the reason for the height difference was unknown. "People have different theories ... our favourite is that maybe something in the IVF process does change the expression of the genes. We wouldn't want to speculate too much because we are looking into it."
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She said researchers from the University of Auckland's Liggins Institute planned further investigations such as examining results from other IVF centres and frozen embryos "to see if they have a difference".
Dr Miles said the study was sparked by IVF sheep and cattle births, which sometimes produced large animals, and the growing link between human IVF cases and Beckwith-Wiedemann syndrome, a genetic disease that causes overgrowth.
Monash IVF medical director Gab Kovacs said the study was well designed, with a useful number of IVF subjects that needed to be followed up.

SOURCE: The Age

Nanoscale machines move liquid mountains

Controlled by light, transport the equivalent of world's tallest buildings

A molecular shuttle system

For the first time, nanoscale machines have moved macroscale objects—droplets of liquid that they can even transport up a slope. Researchers working on the project say that the feat is equivalent to a conventional mechanical machine using a millimeter displacement of pistons to lift an object twice the height of the world's tallest building.The scientists, from Edinburgh, Groningen and Bolognam, covered a gold surface with synthetic molecular "shuttles." Components of the shuttles move up and down by a millionth of a millimeter when exposed to ultraviolet light. This occurs because a chemical reaction takes place in one part of the molecule that causes it to repel another part. The changes in position alter the surface tension of a droplet of liquid placed on the gold surface.

In this way, the researchers have used their shuttles to shift microliter drops of diiodomethane both across a flat surface and up a one millimeter, 12-degree slope against the force of gravity.

While a tiny movement, it's considered a large leap forward for nanotechnology, as until now molecular machines largely haven't interacted with objects in the everyday world.

"Nature uses molecular machines in virtually every biological process and, when we learn how to build and control such structures, we will surely find they have the potential to revolutionize molecular-based technologies, from health care to 'smart' materials," says principal researcher David Leigh of the University of Edinburgh. "Molecular machines could be used to make artificial muscles, surfaces that change their properties in response to electricity or light or even—one day in the future—to move objects about a room using a laser pointer."

The research was announced at the BA Festival of Science in Dublin, and was reported in the journal Nature Materials.

Human stem cells become unstable in the lab

Human embryonic stem cell colonies in different stages of development.

Stem cells cultured for long periods in the lab develop genetic changes in areas known to be involved in human cancers, researchers are warning. The potential therapeutic benefits of human embryonic stem cells, which so many researchers are pinning their hopes on, should perhaps come with a “best before date”, US-based researchers suggest. “It seems that there must be something in the cell culture that turns on some genetic pathways, which in the body would normally be modulated,” says Aravinda Chakravarti, who led the research at the Johns Hopkins University School of Medicine in Baltimore, US.

“We don’t know why stem cells are so sensitive to mutations in vitro, or even if it is just stem cells that show such mutations over time, but certainly the medium in which they are cultured needs to be investigated,” he adds.

Metabolic function
The research is a setback for stem cell science and contradicts an earlier study which found no significant changes to the genomes of lab-cultured stem cells. Chakravarti and colleagues found serious genetic alterations in eight of the nine cell lines they cultured, including large DNA deletions and amplifications in certain regions of the genome over time.

They also found mutations in the mitochondrial DNA, which could affect the metabolic functions of the cells, as well as changes in the patterns of DNA methylation – the process which chemically alters which genes are “switched on or off”.

This sort of alteration in how genes are expressed, called epigenetic inheritance, had been seen in lab-cultured embryonic stem cells from mice, but a previous study in human cultured embryonic stem cells had concluded that the genome was very stable over time.

Huge implications
Chakravarti and colleagues followed the lines of stem cells as they were cultured, examining them twice – first at an average of 35 passages (after the cells had divided 35 times) and then 20 passages later. In the latter testing of cells, they found 90% showed changes in patterns of methylation, 22% had mutations in mitochondrial DNA and 50% had major deletions or amplifications in the DNA.

“Perhaps if stem cells are transplanted therapeutically, they should be restricted to early passage stem cell lines,” Chakravarti suggests.

But much of the current research into therapeutic uses for stem cell lines involves growing the lines until they differentiate into a tissue type – Chakravarti’s research could have huge implications for this emerging field of medical research.

“The first thing it should lead to is a greater understanding of what happens when we culture cells – it may be that stem cells don’t turn out to be especially sensitive to mutations,” he told New Scientist.

Journal reference: Nature Genetics (DOI: 10.1038/ng1631)

SOURCE: NewScientist

Silicon Nanotechnology to Combat Biowarfare Agents

Image: Schematic of a fabricated 4X4 electrical biosensor array. (Courtesy of Infotonics Technology, Designed by Philippe Fauchet)

In fall 2001, several letters containing deadly spores were sent to targeted spots across the county. The documents threatened the lives of postal workers, government administrative workers, officials and others. Countless other letters were sent which contained harmless white powder. At that time, swabbing for anthrax and sending the samples to the few labs that could test them took an excruciating amount of time - particularly for the people who were awaiting the results.

Researchers at the University of Rochester are developing a smart-system
that would detect - and combat - the biowarfare agents. Research finds early
detection and diagnosis is critical to ensure public safety and minimize the
impact of agents such as anthrax. The biosensors will be able to function
remotely inside buildings. The prototype development is a combination of
nanoscience, nanotechnology and optics and fills an imminent national security
need, researchers say.

Today, an upstate New York consortium of
businesses; Eastman Kodak Co., Xerox Corp. and Corning Inc.; universities; and
state and federal agencies such as the Department of Energy, the Department of
Homeland Security and NASA is getting close to unveiling a prototype that could
change the face of biowarfare detection going forward.

"Smart sensors
are the key to detecting terrorist threats," said David R. Smith, Chief
Executive Officer of Infotonics Technology Center in Canandaigua, New York.
Infotonics is one of five centers of excellence across the state charged with
making cutting-edge advances in fields such as nanotechnology.

Philippe
Fauchet is the director of the University of Rochester's Center for Future
Health. He leads a research team that is finding a fast, cost-effective method
to test for agents like anthrax and plague.

According to Fauchet's
proposal to Infotonics, the group is developing smart responsive sensors that
will form a flexible portable platform capable of detecting and identifying the
presence of multiple biological or chemical agents. The sensors will wander
through buildings conducting a search. They will not only detect the agents but
respond by releasing counteracting drugs. If the sensors can be mass-produced
reliably and inexpensively, they would have a wide range of applications - from
protecting at-risk personnel to monitoring water quality, Fauchet explained.


The key focus of the research is on transforming the sensors into
microsystems that can be easily deployed and operated. The devices will be
optimized for sensitivity, speed and specificity, Fauchet said. "Examples of
these technologies include porous silicon electrical sensors containing pores
ranging from a few nanometers to microns whose complex impedance responds in
seconds to exposure to various targets each with a specific signature," Fauchet
explained.



Image: Scanning electron micrographs of 1-D and 2-D photonic bandgap structures made of silicon and used in biosensing (Courtesy of Infotonics Technology, Designed by Philippe Fauchet)

Infotonics' chief Smith said the center - which
has been up and running for 15 months - continues to work diligently to invest
in Homeland Security research as one of its four initiatives. The others are:
Biotechnology, Information and Communication and Defense and Aerospace.


At its inception, Infotonics invested in 13 projects worth a combined
$4.5 million in an effort to take them through the euphemistic "valley of death"
from the conceptual stage to the marketplace. One year later, executives are
optimistic about the biowarfare detection sensors and the implications for
future advances in technology that could make the country more secure.


"Philippe's work has been one of our most successful research
investments," Smith marveled. "He's delivering really great stuff."



by Allison M. Coopsr
source: PhysOrg.com

Artificial intelligence decodes DNA

An artificial intelligence program has helped decode DNA by peering into mammalian cells and determining where they read genetic information. The program was developed by researcher Brendan Frey and colleagues of the University of Toronto. A news release describes their work: To hunt for genetic instructions, Frey, along with Professor Timothy Hughes and researchers from Mount Sinai Hospital and the Hospital for Sick Children in Toronto, explored samples from 37 mouse tissues.

They used microarraysdevices that probe for DNA sequences using complimentary nucleic acids to light up regions of DNA that were being read by cells in diverse body parts such as the heart, lungs and brain. When nearby regions in the DNA have similar patterns of activity, this indicates they likely belong to a gene.
"We were able to feed the patterns into an artificial intelligence computer program developed in my group," Frey says. "The computer analysis identified thousands of instructions and changed our view of how genes work." For example, their analysis showed that a region of the fourth chromosome which was thought to contain four short genes actually contains a single very long gene, which is now thought to be involved in the assembly of large protein molecules in the nucleus. By better understanding this and other genes, researchers hope to learn how these genes malfunction and cause disease.
The program also revealed a startling discovery: there are no new protein-coding genes to be discoveredthe genetic instructions that are largely responsible for managing cells, determining everything from eye colour to disease. By analysing the data and inferring the most likely genes based on user-programmed variables, the program matched what research has taken 30 years to discover. "This flies in the face of research that says there are many more protein-coding genes to be discovered," Hughes says. "We've reached a milestone in gene exploration."
Frey and colleagues have received a CDN $22-million grant to further their efforts, which will allow them to look into such things as the exploration of what functions the new genes perform and how the cell determines whether or not a gene should be read from the DNA.

SOURCE: Nature Genetics

Nanobiotechnology Under Pressure to Justify the Enormous Private and Public Funding it Has Received

Nanotechnology has received as much media attention than any other science sector since the space race of the 1960s. This hype has attracted large sums of reactionary' public and venture capital funding, and has brought in its wake tremendous pressure on market participants to deliver results. The onus is now on participants in the nanobiotechnology applications sector to incorporate extensively researched technologies into commercially viable products.

New analysis from Frost & Sullivan , World Nanobiotechnology Market, reveals that Sales of nanomaterials for use in nanobiotechnology applications generated revenues of USD 750.0 million in 2004. This figure is projected to reach USD 2,056.5 million in 2011. Nanobiotechnology deals with nanomaterials and their applications in life sciences. Breakthrough applications in nano-scale therapeutics, drug delivery systems, and nano-scale scaffolds for tissue reconstruction are surfacing from laboratories into the development phase. Industry participants need to focus on collaborating well with interdisciplinary research partners to ensure sustainable growth of this emerging market, says Frost & Sullivan Industry Analyst Phil Webster. Such enterprising market strategies are the need of the hour, since many alternative technologies are posing a significant challenge to the nanobiotechnology sector. Conventional therapeutics, liposomes, and monoclonal antibodies are all established therapies and already have regulatory compliance and case law in place, unlike nanobiotechnology, which gives them a competitive edge. As an emerging segment, nanobiotechnology holds great potential in the treatment of neurological disorders and cancer, which are areas of unmet medical need. Most nanobiotechnology products that have satisfied regulatory requirements to date are cosmetics and medicinal creams, which use metallic nanoparticles to improve absorption. Reformulated compounds that use nanoemulsion delivery systems have gained legislative approval and are commercially available. In February 2005, the first nanoparticulate therapeutic reached the market, a major step in the development of the nanobiotechnology market. With improving regulatory climate, market participants are drawing up plans for novel nanobiotechnology products. While devising new applications for nanobiotechnology, competing companies will have to take into account the costs of nanomaterials. Since nanomaterials have not generated much demand owing to the small quantities in which they are required, it is unfeasible to establish large-scale automated manufacturing systems. Reactionary funding is proving essential to the establishment of the nanobiotechnology market. Significant public and private investment in nanobiotechnology are sponsoring research projects in academia and facilitating the establishment of start-up and spin-off companies for commercialising nanobiotechnology applications. The funds have been used to set up sound infrastructure, particularly in the United States and Europe, for small companies to network and collaborate, says Mr Webster. It is essential for industry participants to be aware of what funding sources are available and where, as this indicates hot spots of business opportunity. The World Nanobiotechnology Market, part of the Biotechnology subscription, research service specifically focuses on nanobiotechnology rather than visualisation and diagnostics applications. It analyses nanomaterial markets specific to the nanobiotechnology sector as well as application of these nanomaterials in pure therapeutics, drug delivery systems, and tissue reconstruction.

SOURCE: Science Daily

Nanotechnology Presents Possibility of Implantable Artificial Kidney

Researchers have developed a human nephron filter (HNF) that would eventually make possible a continuously functioning, wearable or implantable artificial kidney.


Actual dialysis methods

This study is published in the latest issue of Hemodialysis International. The HNF is the first application in developing a renal replacement therapy (RRT) to potentially eliminate the need for dialysis or kidney transplantation in end-stage renal disease patients. The HNF utilizes a unique membrane system created through applied nanotechnology. In the ideal RRT device, this technology would be used to mimic the function of natural kidneys, continuously operating, and based on individual patient needs. No dialysis solution would be used in the device. Operating 12 hours a day, seven days a week, the filtration rate of the HNF is double that of conventional hemodialysis administered three times a week. The HNF system, by eliminating dialysate and utilizing a novel membrane system, represents a breakthrough in renal replacement therapy based on the functioning of native kidneys, say researchers. The enhanced solute removal and wearable design should substantially improve patient outcomes and quality of life. According to the study, nearly 900,000 patients worldwide suffer from end-stage renal disease and require treatment through dialysis or transplantation. Animal studies using this technology are scheduled to begin in the next 1-2 years with clinical trials to follow subsequently.

About Hemodialysis International

Adipose tissue stem cells could be used to treat injured or damaged tissues

"Now there is a sense of validation and growing enthusiasm from an increasing number of international researchers who view adipose tissue as a potentially valuable source of therapeutic cells."


Micrographs of adipose (fat) tissue and regenerative cells from adipose tissue (blue stained)

By University of Virginia Health System, National and international scientists, including those from the University of Virginia Health System, will announce findings from a significant number of studies showing that adult stem cells from adipose tissue (fat) could eventually be used to treat injured or damaged tissues. They will present their research findings at the Omni Hotel in Charlottesville, Virginia, September 10-13, during the third annual International Fat Applied Technology Society conference, The Role of Adipose Tissue in Regenerative Medicine: Opportunities for Clinical Therapy. Reporters are invited to attend and a press room will be open to meet their needs.In total, 47 research abstracts will be presented from both academia and the private sector. Findings suggest that adipose-derived stem cells can be used to repair or regenerate new blood vessels, cardiac muscle, nerves, bones and other tissue, potentially helping heart attack victims, patients with brain and spinal cord injuries and people with osteoporosis. The work to be presented reflects a growing number of researchers who believe that adipose tissue (fat) will be a practical and appealing source of stem cells for regenerative therapies of the future."Five years ago we were seen as mavericks," says Dr. Adam Katz, plastic surgeon at the University of Virginia Health System, co-founder and president of the International Fat Applied Technology Society, and conference coordinator. "Now there is a sense of validation and growing enthusiasm from an increasing number of international researchers who view adipose tissue as a potentially valuable source of therapeutic cells.

Source: R&PG News

U of T Research Uncovers Genetic Instructions to Build Life

Life at its most basic level - millions of chemical building blocks holding hereditary information - is controlled by genetic instructions, or genes, responsible for healthy development and protection against disease. By feeding biological data into an artificial intelligence program, University of Toronto researchers have uncovered these instructions to build mammalian life. A paper appearing in the Aug. 28 issue of Nature Genetics describes how researchers used an experimental procedure to peer into a mammalian cell and identify where the cell was reading genetic information.

Efforts such as the Human Genome Project have revealed strings of DNA that contain the instructions controlling life, but the instructions themselves are hidden and cannot be found by studying DNA alone. By uncovering the genes, science is one step closer to targeting diseases such as cancer, where genetic instructions go haywire.
"What the big research efforts in the past decade have done is create a large DNA textbook that contains within it instructions on how to build humans," says Professor Brendan Frey of the Edward S. Rogers Sr. Department of Electrical and Computer Engineering. "However, these projects haven't revealed exactly where and how cells read instructions from DNA. This is difficult because over 90 per cent of DNA within a mammalian cell is thought to perform no function." To hunt for genetic instructions, Frey, along with Professor Timothy Hughes and researchers from Mount Sinai Hospital and the Hospital for Sick Children in Toronto, explored samples from 37 mouse tissues to explore. They used microarrays - devices that probe for DNA sequences using complimentary nucleic acids - to light up regions of DNA that were being read by cells in diverse body parts such as the heart, lungs and brain. When nearby regions in the DNA have similar patterns of activity, this indicates they likely belong to a gene. "We were able to feed the patterns into an artificial intelligence computer program developed in my group," Frey says. "The computer analysis identified thousands of instructions and changed our view of how genes work." For example, their analysis showed that a region of the fourth chromosome which was thought to contain four short genes actually contains a single very long gene, which is now thought to be involved in the assembly of large protein molecules in the nucleus. By better understanding this and other genes, researchers hope to learn how these genes malfunction and cause disease. The program also revealed a startling discovery: there are no new protein-coding genes to be discovered - the genetic instructions that are largely responsible for managing cells, determining everything from eye colour to disease. By analysing the data and inferring the most likely genes based on user-programmed variables, the program matched what research has taken 30 years to discover. "This flies in the face of research that says there are many more protein-coding genes to be discovered," Hughes says. "We've reached a milestone in gene exploration." Frey says that while their work closes a chapter in genomics research, it opens several other major chapters, including the exploration of what functions the new genes perform and how the cell determines whether or not a gene should be read from the DNA. Further, the same piece of DNA can be read in different ways, leading to instructions that can have quite different consequences. To further investigate these issues, Frey and Hughes are collaborating with U of T Professor Benjamin Blencowe of the Banting and Best Department of Medical Research, Professor Robert Hegele at Robarts Research Institute and Professor Stephen Scherer at the Hospital for Sick Children. Genome Canada just announced they will support this effort with a $22-million grant. "I think that genomics research is one of the most compelling areas of science today," Frey says. "Many people I talk to, from my seven-year-old son to university students across multiple disciplines, are excited when they find out that we now have the capability to develop an understanding of one of the most fundamental aspects of life."

The research was funded by the Premier's Research Excellence Award, the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation.
Brendan Frey Edward S. Rogers Sr. Department of Electrical and Computer Engineering 416-978-7001 frey@psi.utoronto.ca
Karen KellyU of T Public Affairs416-978-6974k.kelly@utoronto.ca

SOURCE: University Of Toronto

Mouse Genome Much More Complex Than Expected

More than 100 scientists from Australia, Asia, Europe and the US have been probing the genome of the mouse in a joint study lasting several years. Their results in some aspects have completely overturned geneticists' traditional assumptions. The findings are available in the prestigious journal Science on 2nd September. The general conclusion of the study is that the genome of mammals is much more complex than was hitherto supposed. The genetic material of mammals, the DNA, can be compared to an enormous encyclopedia containing the complete blueprint of the animal in question. Yet this comparison is misleading: over the past few years it has been realised that on most pages of the encyclopedia there is no information at all: they contain a chaotic sequence of letters. Mixed in among these pages there are intelligible pages from time to time, the genes.

The DNA encyclopedia is stored in the nuclei of the cells. If the body is to produce a specific protein, the appropriate page of the encyclopedia is copied (rewritten or 'transcribed'). Only the copies can leave the cell nucleus. They consist of a DNA-like material known as mRNA. Each mRNA contains the blueprint for precisely one specific protein -- this at least has been the traditional doctrine.
Three years ago the DNA of the mouse was completely sequenced. An international research team consisting of more than 100 scientists has been attempting since then to isolate and analyse the entire mRNA transcripts in the mouse. Their most astonishing finding is that more than 60 per cent of all mRNAs are not protein blueprints at all. 'We don't know what the function of these RNAs is,' the Bonn neurobiologist Professor Andreas Zimmer admits. However, they seem to be extremely important: even in such different organisms as hens and mice these ostensibly so unimportant RNAs are very similar. If they really had no function they would have mutated during the course of evolution so quickly that there would nowadays be hardly any similarity between them.
The scientists came across an additional interesting phenomenon when they tried to find the 'original sources' of the mRNA copies in the DNA encyclopedia: information and nonsense are apparently not distributed randomly. Instead there are entire chapters with many different protein blueprints, which are separated by long passages devoid of meaning -- Professor Zimmer talks of transcription 'forests' and 'deserts'.
Although the DNA encyclopedia only has a few tens of thousands of intelligible 'pages', the researchers counted more than 180,000 different mRNAs. 'The genetic information is arranged on the DNA in a very complex way,' Professor Zimmer concludes. For example, the 'copiers' in the cell nucleus combine the different 'paragraphs' in the DNA encyclopedia with each other in different ways. Thus there may be several different mRNA copies derived from the same page, which in turn serve as a blueprint for different proteins.
Only twice as many genes as a threadworm?
This observation might also explain the big question why mammals only have about twice as many genes as threadworms, which have a much simpler structure. 'Our study calls into question the classic view that one gene contains the information for exactly one protein,' Professor Zimmer explains. 'Mammals frequently use the selfsame place on the DNA several times over, as a partial blueprint, so to speak, for different proteins. It is becoming more and more evident that mammal genes do not have any clearly defined limits

SOURCE: University Of Bonn

Nanoshuttles move droplets uphill

A paper by a group of European researchers in the September issue of Nature Materials shows how to transform light-induced molecular motion into macroscopic motion of liquid droplets. Biasing the random motion of molecules is no easy task for chemists, even as we approach the nanotechnology era. Harnessing directional molecular motion and transforming it into measurable mechanical movement is even more of a challenge, although it is commonplace for biological molecular motors found in nature.

David Leigh and colleagues have now developed a surface that is covered with wholly synthetic molecular shuttles that shift position when exposed to light. The movement of droplets is not a direct effect of the change in position that occurs within the individual shuttle molecules. Rather, it is an ensemble effect that results from the change in surface wettability after most of the shuttle molecules change position. The phenomenon is so efficient that it generates enough energy to move a microlitre droplet up a twelve-degree slope*. This work represents a key technological breakthrough, and may prove useful in lab-on-a-chip environments, or for performing chemical reactions on a tiny scale without reaction vessels.

Authors: David A. Leigh (University of Edinburgh, UK) Donald Fitzmaurice (University College Dublin, Ireland)

Source: Nature Publishing Group

Researchers produce strong, transparent carbon nanotube sheets

Nanotubes Structures


Carbon nanotubes are like minute bits of string, and untold trillions of these invisible strings must be assembled to make useful macroscopic articles that can exploit the phenomenal mechanical and electronic properties of the individual nanotubes. In the Aug. 19 issue of the prestigious journal Science, scientists from the NanoTech Institute at UTD and a collaborator, Dr. Ken Atkinson from Commonwealth Scientific and Industrial Research Organization (CSIRO), a national laboratory in Australia, report such assembly of nanotubes into sheets at commercially useable rates. Starting from chemically grown, self-assembled structures in which nanotubes are aligned like trees in a forest, the sheets are produced at up to seven meters per minute by the coordinated rotation of a trillion nanotubes per minute for every centimeter of sheet width. By comparison, the production rate for commercial wool spinning is 20 meters per minute. Unlike previous sheet fabrication methods using dispersions of nanotubes in liquids, which are quite slow, the dry-state process developed by the UTD-CSIRO team can use the ultra-long nanotubes needed for optimization of properties. Strength normalized to weight is important for many applications, especially in space and aerospace, and this property of the nanotube sheets already exceeds that of the strongest steel sheets and the Mylar and Kapton sheets used for ultralight air vehicles and proposed for solar sails for space applications, according to the researchers. The nanotube sheets can be made so thin that a square kilometer of solar sail would weigh only 30 kilograms. While sheets normally have much lower strength than fibers or yarns, the strength of the nanotube sheets in the nanotube alignment direction already approaches the highest reported values for polymer-free nanotube yarns. The nanotube sheets combine high transparency with high electronic conductivity, are highly flexible and provide giant gravimetric surface areas, which has enabled the team to demonstrate their use as electrodes for bright organic light emitting diodes for displays and as solar cells for light harvesting. Electrodes that can be reversibly deformed over 100 percent without losing electrical conductivity are needed for high stroke artificial muscles, and the Science article describes a simple method that makes this possible for the nanotube sheets. The use of the nanotube sheets as planar incandescent sources of highly polarized infrared and visible radiation is also reported in the Science article. Since the nanotube sheets strongly absorb microwave radiation, which causes localized heating, the scientists were able to utilize a kitchen microwave oven to weld together plexiglas plates to make a window. Neither the electrical conductivity of the nanotube sheets nor their transparency was affected by the welding process -- which suggests a novel way to imbed these sheets as transparent heating elements and antennas for car windows. The nanotube sheets generate surprisingly low electronic noise and have an exceptionally low dependence of electronic conductivity on temperature. That suggests their possible application as high-quality sensors - which is a very active area of nanotube research. "Rarely is a processing advance so elegantly simple that rapid commercialization seems possible, and rarely does such an advance so quickly enable diverse application demonstrations," said the article's corresponding author, Dr. Ray H. Baughman, Robert A. Welch Professor of Chemistry and director of the UTD NanoTech Institute. "Synergistic aspects of our nanotube sheet and twisted yarn fabrication technologies likely will help accelerate the commercialization of both technologies, and UTD and CSIRO are working together with companies and government laboratories to bring both technologies to the marketplace." The breakthroughs resulted from the diverse expertise of the article's co-authors. Dr. Mei Zhang and Dr. Shaoli Fang, NanoTech Institute research scientists, first demonstrated the nanotube sheet fabrication process, and this result was translated into diverse applications by the entire team. The other team members include Dr. Anvar Zakhidov, associate director of the NanoTech Institute; Christopher Williams, Zakhidov's graduate student from the UTD Physics Department; Dr. Sergey Lee and Dr. Ali Aliev, research scientists at NanoTech Institute, in addition to Atkinson and Baughman. The applications possibilities seem even much broader than the present demonstrations, Baughman said. For example, researchers from the Regenerative Neurobiology Division at Texas Scottish Rite Hospital for Children, Dr. Mario Romero, Director, and Dr. Pedro Galvan-Garcia, Senior Researcher Associate, and Dr. Larry Cauller, associate professor in UTD's neuroscience program, have initial evidence suggesting that healthy cells grow on these sheets - so they might eventually be applied as scaffolds for tissue growth. Baughman said that numerous other applications possibilities exist and are being explored at UTD, including structural composites that are strong and tough; supercapacitors, batteries, fuel cells and thermal-energy-harvesting cells exploiting giant-surface-area nanotube sheet electrodes; light sources, displays, and X-ray sources that use the nanotube sheets as high-intensity sources of field-emitted electrons; and heat pipes for electronic equipment that exploit the high thermal conductivity of nanotubes. Multifunctional applications like nanotube sheets that simultaneously store energy and provide structural reinforcement for a side panel of an electrically powered vehicle also are promising, he said. UTD researchers began collaborating with their counterparts at CSIRO last year. In November 2004, the organizations achieved a breakthrough by downsizing to the nanoscale methods used to spin wool and other fibers to produce futuristic yarns made from carbon nanotubes. The latest research was funded by the Defense Advanced Research Projects Agency, an agency of the United States Department of Defense, the U.S. Air Force Office of Scientific Research, the Texas Advanced Technology Program, the Robert A. Welch Foundation and the Strategic Partnership for Research in Nanotechnology.

Source: University of Texas at Dallas

Switching between liquid and gel

Twisted nanostructures are an important biological motif-just think of the DNA double helix or proteins with helical sections important to their function. Researchers are anxious to produce artificial helices, which could be useful in nanotechnological applications. Korean researchers have now successfully created a molecular system that can even form helices on demand, turning the initially liquid solution into a gel.

A team at Yonsei University in Seoul, Korea, headed by Myongsoo Lee, have developed a special type of molecule as the basic building block for their helices. This involves a base consisting of three aromatic rings which is bent like a boomerang. The central ring has a long, branched side-chain hanging from it. When a silver salt is added to a solution of these molecules, complexes form between the molecules and the positively charged silver ions; the boomerangs really get a hold on the silver ions. If the negatively charged counterion in the silver salt is boron tetrafluoride (BF4), the complexes pile up into long, twisted columns. The BF4 ions fit exactly into the cavity that remains inside the belly of the helices and stabilize them. This results in a surprise: The liquid turns into a jelly-like mass. How does this happen? It turns out that the helices aggregate into regular bundles of fibers, which get tangled up with each other to form an interwoven, three-dimensional network. The liquid remains trapped inside this fibrous framework; this forms a gel, a kind of intermediate between a liquid and a solid. If a fluoride salt is then added to the gel, it liquefies. This is a result of the enormous attraction of the fluoride ions (F) for the silver ions, which are lured out of their complexes. The fibrous aggregates collapse back into individual molecules. This effect is reversible if the fluoride ions are trapped by the addition of other salts. If salts containing the C2F5CO2 ion are added to the gel, it also liquefies. Electron microscopy images show that in this case, the phenomenon has a different cause. The complexes do not fall apart into individual molecules, but form a different structure instead. Instead of interwoven helical columns, they form individual zigzagging bands. The reason for this change instructure is the difference in size of the anions: C2F5CO2 is bigger than BF4 and thus does not fit into the cavity inside the helices, which are thus not stabilized. The result of all this is the birth of a new type of intelligent nanomaterial whose properties can be switched solely by the choice of counterion.

SOURCE: Angewandte Chemie International Edition

Carbon Nanotube Electronics Will Lead to .6 Billion in Business

IBM is evaluating the potential of carbon nanotubes as the basis of a future nanoelectronics technology, as shown, for example, in this computer illustration of a top-gated field effect transistor

According to a new report from NanoMarkets LC, a market research and consulting firm based here, the unique electrical, thermal and physical properties of carbon nanotubes (CNTs) will create .6 billion in new business for the electronics and semiconductor sectors by 2009.

NanoMarkets' research
indicates that carbon nanotubes are already becoming a key enabling technology
that electronics firms should not dismiss as being a long way off.
The report, "Carbon Nanotube Electronics, A Technology Analysis
and Market Forecast," says that the biggest near-term opportunities for
"nanotube electronics" will come from the sensor, display and memory sectors.
Each of these markets will include more than 0 million in CNT-based products by
2007:
Nanotubes are already being used to produce tiny sensors,
potentially capable of distinguishing a single molecule. This could make
nanotubes the material of choice for the highly sensitive sensors required for
medical and homeland security applications. The low power consumption of
nanotube sensors also makes them ideal choice for battery-powered sensor
networks.
Nanotube-based field emission displays combine the high-quality
video of CRTs with the flatness of LCD and plasma displays, but without the
burn-in and poor viewing angles associated with today's flat-panel displays.
Samsung will release its CNT-driven television in 2006. Other large electronics
firms that are developing such displays include Hitachi , Sony, Mitsubishi and
Toshiba.
Nanotube-based memories will combine the speed of SRAM with the
non-volatility of Flash, which should allow them to quickly penetrate the
laptop, mobile phone and PDA markets. NanoMarkets believes this market could
generate hundreds of millions of dollars in revenue.
NanoMarkets also notes that CNT-based interconnects and thermal
management could help provide CMOS with a much needed enabling technology as it
moves to 45-nm and 22-nm nodes. Nanotube-based logic, processors, interconnects
and thermal management solutions are already the subject of intense research by
IBM, Intel and NEC which believe that their work in this field will help CMOS
scale to smaller feature sizes.

SOURCE: Physics Today

Nanotechnology cuts windscreen fog

Scientists at the Massachusetts Institute of Technology have come up with a high-tech solution to stop car windows and windscreens (and spectacles) from fogging up. They have developed a polymer coating of silica nanoparticles which can be applied to glass surfaces for a permanent solution which works in all light conditions,remaining fully translucent.

Previous proposals to solve the problem have involved the use of titanium dioxide, but this only works in the presence of ultraviolet light.
The polymer coating attracts water droplets and forces them to flatten into a transparent sheet rather than forming into drops or globules; it has anti-reflective properties which can reduce glare and maximize the light passing through. The MIT team has now applied for a patent, and says that "at least two" major car manufacturers and the US military have expressed interest in using the technology.
SOURCE: 4car

Scientists Decipher Chimp DNA

Scientists have deciphered the DNA of the chimpanzee, the closest living relative of humankind, and made comprehensive comparisons with the human genetic blueprint. It's a step toward finding a biological answer to a key question: What makes us human? There are no firm answers yet about how humans picked up key traits such as walking upright and developing complex language. But the work has produced a long list of DNA differences with the chimp and some hints about which ones might be crucial.

"We've got the catalog, now we just have to figure it out," said Dr. Robert Waterston of the University of Washington School of Medicine in Seattle. "It's not going to be one gene. It's going to be an accumulation of changes."

He is senior author of one of several related papers appearing in Thursday's issue of the journal Nature and being published online Thursday by the journal Science.

In the papers, Waterston presents a draft of the newly deciphered sequence of the chimp genome, in which an international team of researchers identified virtually all the roughly 3 billion building blocks of chimp DNA.

"It's a huge deal," said Dr. Francis Collins, director of the National Human Genome Research Institute, which provided some support for the project. "We now have the instruction book of our closest relative."

He said the work will help scientists analyze human DNA for roots of disease.

While the DNA comparisons don't firmly identify specific differences that played a big role in producing humans, they do indicate promising areas, said Bruce Lahn, who studies human evolution genetics at the University of Chicago but didn't participate in the project. Lahn said the research refutes a few previous ideas while providing new and better evidence for others.

Humans and chimps have evolved separately since splitting from a common ancestor about 6 million years ago, and their DNA remains highly similar -- about 96 percent to almost 99 percent identical, depending on how the comparison is made.

Still, the number of genetic differences between a human and a chimp is about 10 times more than between any two humans, the federal genome institute says. It's the differences -- some 40 million -- that attract the attention of scientists.

Waterston and colleagues, for example, looked for genes that apparently have changed more quickly in humans than in chimps or rodents, indicating they might have been particularly important in human evolution. They found evidence of rapid change in some genes that regulate the activity of other genes, telling them when and in what tissues to become active, for example.

It would make sense that changes in these regulatory genes could have a broad impact on how organisms develop, playing a key role in human evolution, Waterston said.

With help from the chimp DNA, his team also uncovered several regions of human DNA that apparently contain beneficial genetic changes that spread rapidly among humans within the past 250,000 years. One area contains a gene called FOXP2, which previous work has suggested is involved in acquiring speech.

Svante Paabo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues report in the Science paper that genes active in the brain have changed more in the human lineage than in the chimp lineage. That wasn't the case for genes from other organs such as the heart and liver.

In a telephone interview, Paabo said that in general, "I'm still sort of taken aback by how similar humans and chimps are" in their DNA. "I'm still amazed, when I see how special humans are and how we have taken over this planet, that we don't find stronger evidence for a huge difference in our genomes."

He said he believes the key differences between the species will prove to be subtle things such as patterns of gene activity and how proteins interact.

In fact, Waterston and co-authors said they hoped documenting the overall similarity of chimp and human genomes will encourage action to save chimps and other great apes in the wild:

"We hope that elaborating how few differences separate our species will broaden recognition of our duty to these extraordinary primates that stand as our siblings in the family of life."



SOURCE: Associated Press