A bold experiment

A handful of Alzheimer’s patients signed up for a bold experiment: They let scientists beam sound waves into the brain to temporarily jiggle an opening in its protective shield.

The so-called blood-brain barrier prevents germs and other damaging substances from leaching in through the bloodstream – but it can block drugs for Alzheimer’s, brain tumors and other neurologic diseases, too.

Canadian researchers last week reported that early hints that technology called focused ultrasound can safely poke holes in that barrier – holes that quickly sealed back up – a step toward one day using the non-invasive device to push brain treatments through.

“It’s been a major goal of neuroscience for decades, this idea of a safe and reversible and precise way of breaching the blood-brain barrier,” said Dr. Nir Lipsman, a neurosurgeon at Toronto’s Sunnybrook Health Sciences Centre who led the study. “It’s exciting.”

The findings were presented at the Alzheimer’s Association International Conference in Chicago and published in Nature Communications.

This first-step research, conducted in just six people with mild to moderate Alzheimer’s, checked if patients’ fragile blood vessels could withstand the breach without bleeding or other side effects – it didn’t test potential therapies.

More safety testing is needed but “it’s definitely promising,” said Dr. Eliezer Masliah of the National Institute on Aging, who wasn’t involved with the study. “What is remarkable is that they could do it in a very focused way, they can target a very specific brain region.”

Alzheimer’s isn’t the only target. A similar safety study is underway in Lou Gehrig’s disease. And researchers are testing if the tool helps more chemotherapy reach the right spot in people with a deadly brain tumour called glioblastoma.

“We don’t want to broadly open the blood-brain barrier everywhere. We want to open the blood-brain barrier where we want the treatment to be delivered,” explained Dr. Graeme Woodworth of the University of Maryland Medical Center, who will lead a soon-to-begin brain tumour study.

Scientists have long tried different strategies to overcome the blood-brain barrier with little success. The brain’s blood vessels are lined with cells that form tight junctions, almost like a zipper. The barrier lets in select small molecules. Often, treatments for

What’s a man to do? Equally important, what’s a doctor to advise when the PSA test is reported elevated? Or should men even be screened for this test? During the last 10 years there’s been considerable fliplopping about it. Now a large study from the United Kingdom, reported in The Journal of the American Medical Association has new recommendations about PSA testing.

First, this shocking finding. The study showed that men who take the PSA test are just as likely to die of prostate cancer as those who do not have the test! Moreover, some men who do take a PSA are exposed to unnecessary treatment and develop complications that are very annoying.

It’s also worth knowing that if the test is positive for prostate malignancy, it may be wrong. The elevation may be due to an inflammation of the gland, increased size of the prostate (benign prostatic hypertrophy), having sex 24 hours before the test. There’s even some evidence that riding a bicycle 48 hours before the test can increase PSA.

So, what’s new about the British study? First, it’s a large one of 400,000 men, aged 50 to 69. Part of the group agreed to a one-time test. Of this group, 11 per cent had abnormal PSA and most agreed to a biopsy. Another group of the same age range were not offered a test and served as a control group. Ten years later the number of men who had died of prostate cancer was nearly identical.

What should men do? The decision to have, or not have, the test must always be left to the patient and his doctor. The general consensus among experts is that men should ask their doctor about testing at age 50. But males at higher risk should start earlier. And that, if the decision is to test, it should continue every two to four years until age 75.

This statistical study questions