Scientists have managed to protect and regenerate the part of the brain that is damaged in Parkinson's disease, by genetically engineering cells to bypass the blood-brain barrier.
The blood-brain barrier protects the brain from harmful substances, but also prevents drugs from entering, so experimental treatments have involved injecting drugs directly into the brain.
The drugs can be sneaked past the blood-brain barrier by engineering and implanting progenitor brain cells derived from stem cells to produce and deliver a critical growth factor that has already shown clinical promise for treating Parkinson's disease.
Writing in the journal Gene Therapy, University of Wisconsin-Madison neuroscientist Clive Svendsen and his colleagues describe experiments that demonstrate that engineered human brain progenitor cells, transplanted into the brains of rats and monkeys, can effectively integrate into the brain and deliver medicine where it is needed.
"This work shows that stem cells can be used as drug delivery vehicles in the brain," says Svendsen. The new study, Svendsen argues, proves that progenitor cells--cells that can now be made in large quantities in the laboratory--can be crafted to help clinicians deliver drugs where they are needed most in the body. Delivering medicine to the brain, whose blood-brain barrier effectively excludes more than 70 percent of all drugs, would be an especially valuable use for the cells. Such a new method may be useful for treating a number of neurodegenerative diseases beyond Parkinson', he says.
Read the full story in the Wisconsin-Madison press release, Engineered stem cells show promise for sneaking drugs into the brain at BrightSurf or NewScientist's 'Trojan cells' treat brain diseases from the inside article.
A study conducted at the San Francisco VA Medical Center has identified a protein found in both mice and humans that appears to play a key role in protecting neurons from oxidative stress, a toxic process linked to neurodegenerative illnesses including Alzheimer's and Parkinson's diseases.
The study, led by Raymond Swanson, MD, chief of neurology and rehabilitation services at SFVAMC, identified the protein--known as EAAC1 in mice and as EAAT3 in humans--as the main mechanism through which the amino acid cysteine is transported into neurons.
EACC1-deficient mice were found to have many conditions which also occur in Alzheimer's patients, such as abnormally enlarged ventricles, fewer neurons in the hippocampus, and that all neurons in the hippocampus and cortex showed evidence of oxidative stress. They also found that it took ten times less hydrogen peroxide--a powerful oxidant--to kill slices from the EAAC1-deficient mice, indicating that these were ten times as vulnerable to oxidative stress.
The good news is that, for several days, a group of gene-deficient mice were fed N-acetylcysteine, an oral form of cysteine that is readily taken up by neurons. When their neuron slices were compared with slices from untreated gene-deficient mice, it was found that N-acetylcysteine (NAC) "had completely corrected the biochemical defect" in their neurons, recounts Swanson. "Their glutathione levels were normal, their ability to withstand hydrogen peroxide toxicity was normal, and the oxidants we saw in the neurons in response to oxidative challenges were normal."
NAC is a form of the amino acid cysteine which enhances the production of the glutathione, one of the body's powerhouse antioxidants.
Read the full Key brain antioxidant linked to Alzheimer's and Parkinson's article at BrightSurf.
A new study, conducted at Vanderbilt by chemical engineers Peter T. Cummings and Alberto Striolo and published in December 2005 in Biophysical Journal, raises a red flag regarding the safety of buckyballs when dissolved in water.
It reports the results of a detailed computer simulation that finds buckyballs bind to the spirals in DNA molecules in an aqueous environment, causing the DNA to deform, potentially interfering with its biological functions and possibly causing long-term negative side effects in people and other living organisms
Researchers caution that the simulations do not prove that buckyballs actually do any damage in the real world. But the work does raise another concern about possible dangers of nanotechnology.
“The binding energy between DNA and buckyballs is quite strong,” Cummings says. “We found that the energies were comparable to the binding energies of a drug to receptors in cells.”
It turns out that buckyballs have a stronger affinity for DNA than they do for themselves. “This research shows that if buckyballs can get into the nucleus, they can bind to DNA,” Cummings says. “If the DNA is damaged, it can be inhibited from self-repairing.”
The worry is that even familiar materials, such as carbon, might have completely different health effects at the nanoscale. One recent study, for instance, found that buckyballs accumulate in the brains of largemouth bass and cause cell damage.
See the detailed Computer simulation shows buckyballs deform DNA on BrightSurf and
Buckyballs could disrupt functioning of DNA at NewScientist
Acetaminophen, the popular painkiller found in Tylenol and similar products, is now the leading cause of acute liver failure in the US - and almost half of those cases are accidental overdoses.
Between 1998 and 2003, the proportion of cases of liver failure caused by the drug nearly doubled.
Of the 275 people with acetaminophen poisoning, in a recent study, 8 per cent received a liver transplant, 65 per cent survived without one and 27 per cent died. People who intentionally overdosed had similar damage to those who overdosed accidentally. That suggests a clear threshold for what constitutes a safe dose of the drug.
Many of the people who had accidentally poisoned themselves did so by taking just 10 grams of the medication each day for about three days - the equivalent of about 20 pills per day instead of the recommended eight, an overdose that might be less serious with other drugs. Other people had unwittingly taken two products that both contained the drug.
Read the full story at NewScientist.
Now you can repel those annoying teenagers while leaving nice fortysomethings and retirees go about their business unmolested.
Howard Stapleton's "Mosquito" invention emits an ultrasonic sound which can be heard by most kids and teenagers but is inaudible to the majority of adults over 30 due to the inevitable deterioration of hearing with age.
See Inventor deploys hoodie-busting sonic weapon at The Register.
Researchers have succeeded in building an ultrasensitive metal detector by embedding tiny magnets in silicon.
The creation relies on tiny magnets lying in a scaffolding of about 4 square millimetres of silicon. When a tiny magnet senses another magnetic object within range, it turns slightly and exerts a force on the equally tiny fingers of silicon supporting it.
To detect these forces, the researchers look at how the resonance frequency of the silicon crystal has changed. From these signals they can deduce the presence of metals.
At present, the device can pick up on a plumber's wrench up to 5 metres away, says Steve Simon, executive vice-president of engineering, research and development at mPhase Technologies. The ultimate goal is to shrink the electronics of the device down to a single chip, and make it sensitive to objects the size of a rifle more than 30 metres away.
See, Nature's "Metal detectors get shrinking feeling" article.
Armed dolphins may be loose in the Gulf of Mexico, freed by hurricane Katrina.
Experts who have studied the U.S. Navy's cetacean training exercises fear that as many as 36 escaped mammals could be carrying 'toxic dart' guns. Dolphins, considered one of the species with intelligence second only to man's, now threaten divers and surfers. The U.S. Navy admits it has been training dolphins for military purposes, but has refused to confirm that any are missing.
The Navy started the Cetacean Intelligence Mission in 1989, outfitting dolphins with harness and electrodes, and teaching them to protect Trident subs in harbor. Dolphins have been used to detect mines near an Iraqi port. It is apparent the government has been working on using dolphins as weapons.
The mystery surfaced when a separate group of dolphins was washed from a commercial oceanarium on the Mississippi coast during Katrina. Eight were found with the navy's help, but the dolphins were not returned until US navy scientists had examined them.
Learn more at The Observer's "Armed and dangerous - Flipper the firing dolphin let loose by Katrina" or LiveScience's "Armed Dolphins Said Set Loose in Gulf by Katrina" article.
High doses of vitamin E may help mice live longer, according to a new study by Spanish and Argentinean researchers.
Male mice given the vitamin lived an average 40% longer than their peers and showed a much higher level of acrobatic prowess when they performed on a high-wire tightrope, the researchers found. The improvements were due to the vitamin’s antioxidant properties, they say.
But long life is not necessarily associated with quality, so Ana Novarro and colleagues from the University of Cadiz in Spain, and Alberto Boveris and colleagues from the University of Buenos Aires in Argentina, looked at the creatures’ abilities to perform various tests.
They found that those on the vitamin E diet were better than the others at crossing a 50 centimetre-high wire tightrope and negotiating a T-shaped maze. And as they reached a grand old age, the differences were more stark – while those on a normal diet deteriorated rapidly, the mice given regular vitamin E continued to perform well, performing up to 45% better at tests.
Vitamin E gives mice a longer, more acrobatic life at NewScientist.
"Miracle mice" that can regenerate amputated limbs or damaged vital organs have been created, making them able to recover from injuries that would kill or permanently disable normal animals.
The experimental animals are unique among mammals in their ability to regrow their heart, toes, joints and tail.
And when cells from the test mouse are injected into ordinary mice, they too acquire the ability to regenerate, the US-based researchers say.
The research leader, Ellen Heber-Katz, professor of immunology at the Wistar Institute, a US biomedical research centre, said the ability of the mice at her laboratory to regenerate organs appeared to be controlled by about a dozen genes.
"It is quite remarkable. The only organ that did not grow back was the brain.
"When we injected fetal liver cells taken from those animals into ordinary mice, they too gained the power of regeneration. We found this persisted even six months after the injection."
In another test some of the tail was cut off, and this also regenerated. Then the researchers used a cryoprobe to freeze parts of the animals' hearts, and watched them grow back again. A similar phenomenon was observed when the optic nerve was severed and the liver partially destroyed.
Read the full 'Miracle mouse' can grow back lost limbs article at The Sunday Times (UK) or the
It's a miracle: mice regrow hearts article at The Australian
A gene which appears to be a "master control gene for the skin" may hold the key to youth, suggests a new study in mice. The finding could lead to breakthroughs in anti-ageing strategies, skin care and even chemotherapy.
The gene p63, a sister gene to the cancer suppressing p53 gene, was found to accelerate ageing in adult mice when it was "switched off" by researchers.
"There might be great things we can do to keep our skin looking healthy and young looking," said Alea Mills, an assistant professor at Cold Spring Harbor Laboratory. But she cautions that previous studies have shown that too much p63 can lead to cancer, so a "fine balance" needs to be struck.
Mills says the p63 gene is very similar between humans and mice. "We think that p63 is likely to play a fundamental role in maintaining human skin as well."
See the Master gene for skin may hold key to youth article at NewScientist