A computer image mapping parts of the brain.

Strokes cause brain damage within three minutes, scientists reported, casting doubt on the common public perception that all strokes can be medically treated within three hours.
The findings show that prevention is the best strategy for one of the top killers in the developed world, said Dr. Tim Murphy, a neuroscientist at the University of British Columbia in this Western Canadian city, AFP reported.
“There’s a lot of thinking, ’if I’ve had a stroke I’ve got to get to the hospital and I’ll be OK as long as I get there in three hours,“ Murphy told AFP.
Some people can be helped within that time, but “I’m saying, there are structural changes that happen very early on, and so the best thing is to manage risk factors and alter lifestyle,“ Murphy said.
About 80 percent of strokes are ischemic, and are caused by a clot blocking blood flow to the brain, according to the Heart and Stroke Foundation of Canada, which helped to fund the research.
Such strokes are most often treated by clot-busting drugs (trombolytic therapy), if given in hospital within three hours.
“But the reality is, not everyone is a candidate for clot busting drugs, they don’t always work,“ said Murphy.
Murphy said researchers induced strokes in laboratory mice by blocking blood flow to the brains of the animals. At the same time, they used a high-tech imaging technique, two-photon excitation microscopy, to create a “movie“ that revealed the impact.
The mice experienced a “massive electrical discharge, called ischemic depolarizations, a wave of activity that spreads across the brain,“ and then experienced swelling in brain nerve cells, called neurons, said Murphy.
Normal connections between such cells are “a beautiful chain of wiring between one neuron and another that look like trees with elegant branches,“ said Murphy. “After a stroke they look like sausages (or) like beads on a string, and there’s no neuronal activity.“
Murphy said research shows quickly replacing the blood flow to the lab mice can reverse most nerve-cell damage, but some six percent of the connections can never return to normal.
The three-minute window before brain damage from a stroke doesn’t give people enough time to even call for help, said Murphy. “We can’t treat in three minutes.“
But the findings may help people undergoing surgery that can trigger ischemic stroke, he said, because the three-minute window shows the urgent need for preventive measures.
Risk factors for stroke include smoking, being overweight, physical inactivity, alcoholism, diabetes, stress and cholesterol, said the foundation.
Strokes are the fourth leading cause of death in Canada, striking as many as 50,000 people and killing 16,000 annually in a population of 3.3 million.

An artist's concept of the Moonlite mission in an image courtesy of the British National Space Centre (BNSC).

British and US scientists said they were exploring plans for a joint lunar mission that would use an orbiter to fire missile-like penetrators into the moon’s surface.
The Moon Lightweight Interior and Telecoms Experiment, or MoonLITE, would put a satellite into orbit around the moon. Three or four projectiles packed with scientific instruments would then be fired and embed just below the lunar surface, the British National Space Center and NASA said in a statement.
The scientists said MoonLITE could deliver important information about the moon’s structure, such as the size of the lunar core and the source of lunar seismic activity, AP said.
The mission would also provide an opportunity to test the space communications network needed for future robotic or human explorers.
NASA and the British space center said more study and a definitive cost estimate were needed before making a decision on whether to proceed with the proposed mission.
The statement came a day after the government’s space minister, Ian Pearson, said officials were reconsidering a 1986 decision for Britain not to pursue its own manned space flights.
Britain doesn’t want to be left out of an “international wave of new space exploration in the next 10 to 20 years,“ Pearson said while announcing plans for a new space research center to be built near Oxford.
He said a review of manned spaceflight options would come out either this year or next, and in the meantime Britain would likely remain focused on robotic space exploration.

New research by scientists at the University of North Carolina (UNC) at Chapel Hill shows for the first time that an important family of proteins known to function at the cell surface also functions at a site within the cell.
The findings have potential implications for drug development as they involve G protein-coupled receptors (GPCRs). These molecules are the target of forty to fifty percent of modern medicinal drugs, such as antihistamines and drugs for high blood pressure, ScienceDaily wrote.
The study identified the first protein to activate the G-protein signaling pathway from within a cell. In humans, reactions to everything from taste and smell to stimulants like adrenaline or caffeine requires G-protein signaling.
Until now, the only known way to turn on a G-protein was via a receptor sitting on a cell’s surface membrane. This receptor acts like a telegraph operator, accepting outside signals and relaying them inside the cell. It converts an external signal, like caffeine, into action--in this case, a nerve signal to the brain.
More than half of all drugs, from asthma and heart medicine to antidepressants, target G-protein receptors. Discovering a protein that activates G-proteins from inside a cell could open up an entirely new pathway for drug development, said Henrik Dohlman, Ph.D., senior study author and a professor of biochemistry and biophysics in UNC’s School of Medicine.
“No drug is 100 percent effective, 100 percent free of side effects and 100 percent safe. The more options we have biochemically, the more selective we can be in designing new drugs. If we can find another way of modulating G-proteins, we could expand the drug targets that are available to pharmacology,“ Dohlman said.
Despite 20 years of study, G-protein signaling continues to produce surprises. The advent of the human genome project revealed that some three percent of our DNA is dedicated to these messenger molecules. However, the genomic data also drew biologists away from the research technique the UNC team used to discover the new protein, Dohlman said. “People stopped looking for things that could activate G-proteins using functional criteria,“ he said. Instead, they searched for new receptors and activators based on common genetic patterns.
Mike Lee, a graduate student in the UNC School of Medicine’s department of pharmacology, identified the new protein, called Arr4, in yeast cells. Lee employed a mutant form of G-protein to search for any messengers inside the yeast cell with an affinity for G-proteins.
“We went looking for things that could activate G-proteins but don’t resemble known receptors,“ Lee said.

Women who drink tea may be protecting themselves from a build-up of artery-clogging plaque, so lowering their risk for heart disease and stroke, findings from a French study suggest.
Dr. Mahmoud Zureik and colleagues found that older women who reported drinking at least three cups of tea a day were less likely to have plaque in the carotid arteries in their neck than those drinking less tea, Reuters reported.
The investigators, all with INSERM, France’s national institute for medical research, report their findings in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.
Zureik’s team analyzed ultrasound measures of carotid artery plaque among 2,613 men and 3,984 women, aged about 73 years old on average, in relation to tea drinking and other dietary habits, and medical and personal history obtained during in-person interviews conducted from 1999 to 2001.
Carotid plaques were evident in 44 percent of female non-tea-drinkers, in 42.5 percent of women who reported drinking 1 to 2 cups of tea daily, and in only 33.7 percent of those who reported drinking 3 or more cups per day.
The association between fewer instances of carotid plaques and increased daily tea consumption was independent of other dietary habits, major vascular risk factors, age, area of residence, and education, the investigators note.
“There was no association of tea consumption with carotid plaques in men,“ the team found.
The investigators did not gather data on the types of tea consumed or the duration of tea drinking among participants, and they are unclear why the association occurred among women and not men.

There are only between 400 and 1,000 great hamsters left, living near the eastern city of Strasbourg.

France has earmarked 500,000 euros (735,000 dollars) to save the great hamster, a species threatened with extinction through loss of habitat in its native Alsace, the ecology ministry said.
There are only between 400 and 1,000 great hamsters (Cricetus cricetus) left, living near the eastern city of Strasbourg, and at least 1,500 are needed to reach a threshold of viability, AFP said.
Also known as the European hamster, the burrowing creature is about the size of a guinea pig, with a black belly and light brown back.
The money will mainly go towards protecting areas where the remaining hamster colonies live and to encourage local farmers to grow alfalfa, the hamsters’ food of choice, the ministry said in a press release.
France had been strongly warned by the European Commission last October to beef up action to save the creature, protected under Europe’s “Natura 2000“ law.

Researchers have developed what they believe is the first blood test that accurately detects ovarian cancer at an early stage, Reuters reported.
“The ability to recognize almost 100 percent of new tumors will have a major impact on the high death rates of this cancer,“ senior author Dr. Gil Mor, from Yale University School of Medicine in New Haven, Connecticut, said in a statement.
“We hope this test will become the standard of care for women having routine examinations.“
In 2005, Mor’s team first described a panel of biomarkers that can detect stage I and II ovarian cancer.
In the present trial, reported in the medical journal Clinical Cancer Research, the researchers expanded the panel from four proteins to six, and used a sophisticated assay system to measure protein levels in 362 healthy women and 156 patients newly diagnosed with ovarian cancer.
Alone, none of the biomarkers could distinguish the cancer patients from the healthy comparison group, the researchers report. When all six biomarkers were measured, however, the test identified 95 percent of the cancer patients.
A larger evaluation of the biomarker assay is currently underway.

A bizarre relationship between a gecko and a sap-sucking insect has been caught on camera for the first time. The day gecko, which lives in the forests of Madagascar, has been recorded begging a bug for its dinner, BBC reported.
The lizard repeatedly nods its head at the insect, called a plant hopper, until it flicks over small balls of honeydew for the gecko to dine upon.
It is not yet understood why the insect so willingly offers up honeydew at the lizard’s behest.
Some believe that the presence of the hungry geckos may keep other predators away from the insect.
The footage was recorded for the BBC One series Life In Cold Blood.
It took the crew several attempts to capture this strange behaviour on camera as plant hoppers are very well camouflaged.