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A pill to deal with painful memories?
Imagine being plagued with bad memories, images of such terrible trauma — an accident or an instance of abuse — that they produce an uncontrollable emotional reaction. Now imagine being able to wipe away the pain of those memories.
Scientists are working on a way to do just that. By studying how we lay down our memories, research shows that it is possible to select and alter the way memories are stored in our minds. Roger Pitman, a psychiatrist at Harvard University, has already shown that giving certain drugs to victims of trauma when they were brought in to hospital meant that they were less likely to develop conditions such as post-traumatic stress disorder (PTSD).
Now he believes he can even cure PTSD sufferers years after the event. “Our theory about PTSD is that there’s an excess of stress hormone that sears the memory too deeply into the brain,” said Dr Pitman. “If we can block the effects of those stress hormones, we may be able to prevent people from getting these overly strong memories that can become PTSD.”
The work takes advantage of the way memories — essentially networks of brain cells that each store information on a single event or object — are formed.
Beating bird flu
The prospects for preventing millions of deaths in a flu pandemic have improved with the recent announcement by US scientists that they have engineered a vaccine that protects mice from the sort of strains that killed people in Turkey.
Suryaprakash Sambhara of the Centres for Disease Control in Atlanta and Suresh Mittal from Purdue University wrote in an article published online by the Lancet that they had found a way of making a vaccine that protects against not just one but different strains of the virus.
The vaccine was created by genetically modifying a common cold virus, producing a protein called H5HA which is a component of H5N1 — bird flu. The standard method of production in the past has been to grow a virus strain in millions of fertilized chickens’ eggs, harvest it, purify it and kill it for use in vaccine.
The process takes six months and an estimated 4 billion eggs would be needed to immunize 1.2 billion people, the number thought to be at high risk from a pandemic. The researchers found that vaccinated mice did not die when infected with H5N1.
The H5HA vaccine generated specific T cells (a type of while blood cell that fights infections) — something that conventional flu vaccines do not do. The fact that the vaccine also appears to protect against more than one strain of H5N1 is important because bird flu is adept at mutating.
Red meat linked to cancer
Eating large quantities of red meat can increase your risk of bowel cancer by producing substances in the gut that damage DNA, a study revealed last week.
A comparison of cells from the lining of the colon shows that people who eat a diet high in high red meat have a “significant” increase in levels of DNA damage compared with vegetarians. This damage can increase the risk of developing cancer, say researchers at the Medical Research Council’s (MRC) Dunn human nutrition unit in Cambridge.
The finding follows a major European study last year which indicated that people who eat two portions of red or processed meat a day increase their risk of bowel cancer by 35 per cent compared with those who eat one portion weekly. The research, partly funded by the MRC, monitored the diets of nearly half a million men and women in 10 countries over five years.
The scientists monitored 21 volunteers, who each undertook three 15-day diets. The researchers found that when the red meat diet was compared with the vegetarian diet, there was a “consistent and significant” increase in DNA damage, while damage was intermediate with the red meat/high fibre diet.
The damage was specific to substances called N-nitrosocompounds (NOC) found in increased levels in the large bowel of eaters of red meat. — Dawn/The Guardian News Service
Robotic revolution
Nine years after suffering a major stroke, Chicago resident Bill Journey finally put away his cane. That cane was supposed to be a fixture in his life.
Stroke patients generally have a three-month window for rapid recovery of limb function. After six months, progress tends to be slow or non-existent.
Journey, 67, a retired electrician, found new strength and balance by working with a 500-pound, four-wheeled robot named KineAssist. A few times each week, he would take tentative steps while the robot supported and guided his body. Three weeks later, he was surprised to discover that he could walk on his own — with neither robot nor cane.
KineAssist is just one of a legion of smart machines poised to bring physical therapy, a field that relies heavily on rubber bands, exercise mats and dumbbells, into the high-tech age. Researchers envision a day when robots will become standard equipment in rehabilitation centres, giving stroke patients — and possibly patients with spinal cord injuries — a chance to take their recovery further than previously possible.
The KineAssist, developed at the Rehabilitation Institute of Chicago, is essentially a hip brace and harness that connects to a rolling bank of wires and motors. The whole thing could fit in the back of a mini-van with the seats down.
When a patient steps forward, backward or to the side, the robot follows, using sensors in the brace to detect the patient’s speed and position. If the patient leans too far or loses balance, the brace catches him.
“Think about how you learned to walk,” says James Patton, co-director of the rehabilitation institute’s robotics lab. “You have to fall many times before you learn.” Human therapists, he adds, aren’t always able to prevent or break such falls, despite their dedication: “They just don’t have enough hands to do the therapy,” he says. — Dawn/LAT-WP News Service (c) Los Angeles Times
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