Archive for July, 2008
Autopsies usually point to a cause of death, but now a study of brain tissue collected during these procedures may explain an underlying cause of major depression and suicide, according to University of Western Ontario researcher.
Led by Michael O. Poulter, a professor in the Department of Physiology and Pharmacology in the Schulich School of Medicine & Dentistry and scientist at Robarts Research Institute, the international research group also includes Hymie Anisman of the Neuroscience Research Institute at Carleton University.
This international study is the first to show that proteins that modify DNA directly are more highly expressed in the brains of people who commit suicide. These proteins are involved in chemically modifying DNA in a process called epigenomic regulation. The paper is published in Biological Psychiatry.
The researchers compared the brains of people who committed suicide with those of a control group who died suddenly, from heart attacks and other causes.
They found that the genome in depressed people who had committed suicide was chemically modified by a process that is normally involved in regulating the essential characteristics of all cells in the body.
“We have about 40,000 genes in every cell and the main reason a brain cell is a brain cell is because only a small fraction of the genes are turned on,” says Poulter. “The remaining genes that are not expressed are shut down by an epigenetic process called DNA methylation.”
The rate of methylation in the suicide brains was found to be much greater than that of the control group. Importantly, one of the genes they studied was shown to be heavily chemically modified and its expression was reduced. This particular gene plays a major role in regulating brain activity.
“Interestingly enough, adds Poulter, the nature of this chemical modification is long term and hard to reverse, and this fits with depression.
“The whole idea that the genome is so malleable in the brain is surprising. Finding that epigenetic mechanisms continue to influence gene expression is pretty unusual,” says Poulter. “These observations open an entirely new avenue of research and potential therapeutic interventions.”
Leading the fight is Gunnery Sgt Michael Burghardt, known as ‘Iron Mike’ or just ‘Gunny’. He is on his third tour in Iraq. He had become a legend in the bomb disposal world after winning the Bronze Star for disabling 64 IEDs and destroying 1,548 pieces of ordnance during his second tour.
Then, on September 19, he got blown up. He had arrived at a chaotic scene after a bomb had killed four US soldiers. He chose not to wear the bulky bomb protection suit. ‘You can’t react to any sniper fire and you get tunnel-vision,’ he explains. So, protected by just a helmet and standard-issue flak jacket, he began what bomb disposal officers term ‘the longest walk’, stepping gingerly into a 5 foot deep and 8foot wide crater.
The earth shifted slightly and he saw a Senao base station with a wire leading from it. He cut the wire and used his 7 inch knife to probe the ground. ‘I found a piece of red detonating cord between my legs,’ he says. ‘That’s when I knew I was screwed.’
Realizing he had been sucked into a trap, Sgt Burghardt, 35, yelled at everyone to stay back. At that moment, an insurgent, probably watching through binoculars, pressed a button on his mobile phone to detonate the secondary device below the sergeant’s feet. ‘A chill went up the back of my neck and then the bomb exploded,’ he recalls. ‘As I was in the air I remember thinking, ‘I don’t believe they got me.’ I was just ticked off they were able to do it. Then I was lying on the road, not able to feel anything from the waist down.’
His colleagues cut off his trousers to see how badly he was hurt. None could believe his legs were still there. ‘My dad’s a Vietnam vet who’s paralyzed from the waist down,’ says Sgt Burghardt. ‘I was lying there thinking I didn’t want to be in a wheelchair next to my dad and for him to see me like that. They started to cut away my pants and I felt a real sharp pain and blood trickling down. Then I wiggled my toes and I thought, ‘Good, I’m in business.’ ‘As a stretcher was brought over, adrenaline and anger kicked in. ‘I decided to walk to the helicopter. I wasn’t going to let my team-mates see me being carried away on a stretcher.’ He stood and gave the insurgents who had blown him up a one-fingered salute. ‘I flipped them one. It was like, ‘OK, I lost that round but I’ll be back next week’.’
Copies of a photograph depicting his defiance, taken by Jeff Bundy for the Omaha World-Herald, adorn the walls of homes across America and that of Col John Gronski, the brigade commander in Ramadi, who has hailed the image as an exemplar of the warrior spirit.
Sgt Burghardt’s injuries – burns and wounds to his legs and buttocks – kept him off duty for nearly a month and could have earned him a ticket home. But, like his father – who was awarded a Bronze Star and three Purple Hearts for being wounded in action in Vietnam – he stayed in Ramadi to engage in the battle against insurgents who are forever coming up with more ingenious ways of killing Americans.
Barack Obama declared yesterday that he would shift “the central front in the War on Terror” from Iraq to Afghanistan, promising a “new era of international co-operation” in which America would once more lead — rather than alienate — the rest of the world.
Mr Obama said yesterday that he wanted to secure the border, adding: “We need more troops, more helicopters, more satellites, more Predator drones.” He reiterated that the US forces should be ready to cross into Pakistan without permission “to take out high-level terrorist targets like bin Laden if we have them in our sights”.
not alienate the world
You merge those two quotes, I can’t
A slice of cool, fresh watermelon has effects similar to the impotence drug Viagra, researchers say.
Watermelons contain an ingredient called citrulline that can trigger production of a compound that helps relax the body’s blood vessels, similar to what happens when a man takes Viagra, said scientists in Texas, one of the United States’ top producers of the seedless variety.
Found in the flesh and rind of watermelons, citrulline reacts with the body’s enzymes when consumed in large quantities and is changed into arginine, an amino acid that benefits the heart and the circulatory and immune systems.
“Arginine boosts nitric oxide, which relaxes blood vessels, the same basic effect that Viagra has, to treat erectile dysfunction and maybe even prevent it,” said Bhimu Patil, a researcher and director of Texas A&M’s Fruit and Vegetable Improvement Centre. “Watermelon may not be as organ-specific as Viagra, but it’s a great way to relax blood vessels without any drug side effects.”
Todd Wehner, who studies watermelon breeding at North Carolina State University, said anyone taking Viagra shouldn’t expect the same result from watermelon.
“It sounds like it would be an effect that would be interesting but not a substitute for any medical treatment,” Wehner said.