What’s the News: When vampire bats bite their victims, their saliva releases an enzyme called desmoteplase, or DSPA, into the bloodstream, which causes blood to flow more readily. Several years ago, scientists realized that the same enzyme that gives bats more blood for their bite may also help stroke victims by breaking down blood clots. Dubbed Draculin, this blood-clot-bashing drug has now entered a phase 2 study: In hospitals across the country, scientists are currently comparing Draculin with traditional anticoagulants to see if it increases the three-hour window doctors have to treat post-stroke blood clots. “This is one of the studies that actually extends that window up to 9 hours,” says lead researcher Michel Torbey. “We’re hoping the bat saliva, in itself, dissolves the clot with lower risk of bleeding in the brain afterwards.” Read More
Is plain old aspirin the best medicine to ward off cancer? A new study in The Lancet says that it could definitely help, but researchers urge caution before anybody goes on a low-dose aspirin regimen for this reason.
The study, led by Oxford’s Peter Rothwell, is actually a review of eight previous studies that compared people on regular doses of low-dose aspirin to those on a placebo. The researchers who initially performed the studies were investigating questions like whether the aspirin regimen was effective in lowering the risk of heart disease. But in doing so, they kept detailed records on the more than 25,000 people who were involved in the studies—including their causes of death.
Deaths from esophageal cancer were reduced by 60% in the aspirin-takers (who took the drug for at least five years), compared with the placebo group. Lung cancer deaths were reduced by 30%, colorectal cancer deaths were cut by 40% and prostate cancer deaths were lowered by 10%, compared with the patients who got placebo. What’s more, the longer people took aspirin, the greater their reduction in cancer risk. [TIME]
The United States is still bogged down in uncertainty over which stem cell science the government can and can’t fund, but that doesn’t mean the march of research has ground to a halt. This week brought news of two new human stem cell treatments that are going forward.
In Britain, a former truck driver in his 60s who suffered a stroke has now become the first person to receive an experimental stem cell treatment for the condition. Doctors injected two million fetal stem cells developed by British company ReNeuron into his brain with the hope of stimulating the growth of brain cells and blood vessels.
The patient received a very low dose of stem cells in an initial trial to assess the safety of the procedure. Over the next year, up to 12 more patients will be given progressively higher doses – again primarily to assess safety – but doctors will be looking closely to see if the stem cells have begun to repair their brains and if their condition has improved. [BBC News]
If those treatments go well, those higher doses could go as high as 10 to 20 million cells. ReNeuron scientist John Sinden explains that the fetal cells were taken from a 12-week-old fetus, and were already destined to become brain cells. This treatment is thought to have fewer uncertainties than those that use embryonic stem cells, which can grow into any type of cell and which can sometimes cause tumors.
This week brings more vindication for a childhood full of bumps, bruises, and going outside, rather than sterile modern living. In a long-term study published in The Proceedings of the Royal Society B, U.S. researchers suggest that over-cleanliness could make babies more prone to inflammation later in life, and in turn raise the risk for stroke and heart disease.
Thomas McDade’s team studied more than 1,500 people in the Philippines who had health surveys at age two and then again at age 20. The team tested them for C-reactive protein (CRP), a marker of inflammation. They found that the more pathogens the people had encountered before age 2, the less CRP they had at age 20. Every episode of diarrhoea back then cut the chance of higher CRP later by 11 per cent; every two months spent in a place with animal faeces cut it by 13 per cent. Being born in the dusty, dirty dry season cut the chance by a third [New Scientist].
Stroke patients with damaged vision may be able to restore their sight with the help of computer exercises based on the phenomenon known as blindsight–when a person with vision loss senses something they cannot actually see [Reuters]. Lead researcher Krystel Huxlin explains that people with blindsight may not be able to consciously perceive a visual stimulus, yet when they’re forced to answer questions about it their answers are often correct.
Researchers studied patients whose strokes had damaged their primary visual cortex, and whose impaired vision limits some everyday activities like reading and driving. “This is a type of brain damage that clinicians and scientists have long believed you simply can’t recover from. It’s devastating, and patients are usually sent home to somehow deal with it the best they can” [CBC], says Huxlin. The primary visual cortex is the gateway to the rest of the brain for most of the visual information that comes through the eyes, Huxlin said. That area passes visual information along to dozens of other parts of the brain, which then makes sense of the information, allowing people to see [Bloomberg].