Friday, October 06, 2006


If you think small, non-random samples tell you anything

A new DNA-based allergy vaccine can offer long-lasting relief to hay fever sufferers after just six injections, American scientists have claimed. Patients receiving the experimental vaccine showed an average 60 per cent reduction in typical allergy symptoms, such as sneezing, runny nose, watering eyes and itching for at least two years, compared with those receiving a placebo. Researchers at the Johns Hopkins University School of Medicine, in Baltimore, Maryland, believe that a six-injection treatment with the new vaccine, known as AIC, could offer a significant improvement over traditional allergen immunotherapy, which can require several years of weekly or bi-weekly injections.

AIC contains a short piece of DNA known as an "immunostimulatory sequence" that can modify immune system reactions and reduce the typical symptoms of ragweed allergy, more commonly known as hay fever. The experimental therapy also holds the promise of one day eliminating the need for traditional allergy medicines such as nasal steroids and antihistamines. The study, published today in The New England Journal of Medicine, was conducted during two hay fever seasons using 25 volunteers, aged 23 to 60, with a demonstrated history of ragweed allergy.

Fourteen people received the vaccine, administered as six weekly injections, while eleven others received placebo injections. During the test period, allergic symptoms were monitored and recorded, down to how often volunteers' noses ran and how many times they sneezed. Relief from allergic symptoms was as pronounced in the second year as in the first, even though no more vaccine was administered.

Hay fever is estimated to affect more than seven million Britons. Like other allergies it is caused by an overreaction of the immune system to an otherwise harmless substance, such as tree and plant pollens. In allergic individuals, antibodies known as IgE are responsible for mediating the allergic response.

In the current study, the researchers found that, like standard immunotherapy, AIC blocks the seasonal rise in ragweed-specific IgE in people who are allergic. Investigators at the University of California, in San Diego, had observed previously that a particular sequence of DNA, derived from bacteria, shuts down a T-helper cell (Th2) involved in the body's inflammatory response. It is thought that the vaccine lessens the immune system's excessive reactions to inhaled allergens by stimulating protective cells that turn off the Th2 helper cells. Together, the researchers believe, these results hint that AIC is successfully reprogramming the immune system to tolerate the presence of allergen, without overreacting.

Peter Creticos, medical director of the Johns Hopkins Asthma and Allergy Centre, said that the vaccine worked by suppressing acute allergic reactions such as sneezing, and by helping the body better regulate the chronic inflammation that causes itchy eyes and a runny nose. "Long-lasting relief can be achieved with a concise, six-week injection regimen, as opposed to the current, tedious, four to five-year course of treatment with allergen immunotherapy," Dr Creticos said. "And we're not just treating the symptoms, we're targeting the fundamental defects in the immune system that cause allergy."

Further studies are under way to examine the drug's lasting effects in a larger group of participants. "Our hope is that we can one day provide a long-term cure for hay fever and other chronic inflammatory diseases," Dr Creticos said.


Overeating 'like drug addiction'

An attempt to demonize people who enjoy their food

For obese people overeating is akin to drug addiction, research suggests. Scans on seven overweight people revealed the regions of the brain that controlled satiety were the same as those in drug addicts craving drugs. The US team who carried out the research said the findings could potentially help to uncover new treatments for obesity. The work, led by a New York scientist, is published in the Proceedings of the National Academy of Sciences.

The researchers looked at brain impulses in seven overweight individuals. [Wow! What an impressive sample-size! And carefully randomized too, of course] They had all been previously fitted with a weight-reduction device called an implantable gastric stimulator (IGS). The implant sends electronic signals to the vagus nerve which then relays messages of satiety to the brain, thus reducing the desire to eat.

To study the interaction between the stomach and the brain, the volunteers received two brain scans spaced two weeks apart, one when the implant was turned on and the other while it was switched off. While the volunteers were feeling full and the implant was turned on, the scan revealed an increased metabolism in the hippocampus, an area of the brain associated with emotional behaviour, learning and memory, the orbitofrontal cortex and the striatum.

Lead researcher Dr Gene-Jack Wang, at the Brookhaven National Laboratory, New York, said: "As soon as we saw these scans, immediately it reminded me of what we had studied in drug abuse when people were under a craving situation - the same areas in the brain lit up." He said this supported the idea that there were commonalities in the brain circuitry that underlay food intake and compulsive drug intake. Although the study was small, he added, it would help to further understand the desire to eat and obesity. "It gives us another channel to understand how to treat or prevent obesity."

Professor Jimmy Bell, of the molecular imaging group at Hammersmith Hospital, said: "This is a very interesting paper. "There is a lot of research going on around the world looking for biomarkers - anything that will tell you directly what is going on in a biological process - to understand the relationship between appetite, satiety and emotional factors that control what we eat, and when we eat and how much we eat. "I do not think it is surprising they have found a link between drug addiction and overeating. In a way you can think of eating as a 'necessary addiction' - if we were not addicted to eating, most of us would stop eating."



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? [/sarcasm].


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