Sunday, February 18, 2007



VACCINES AGAINST BAD HABITS?

Vaccinations have long had a starring role in preventing a variety of diseases. But now, researchers are aiming the needle at a new set of targets-smoking, obesity, and illicit drugs. These vaccines, currently in development, could give people a novel way to boost their health and vanquish their vices.

Vaccines have been doing their part to eradicate disease since the 18th century, typically by jump-starting the immune system to fight infectious bacteria and viruses such as those that cause the flu, cholera, or tetanus. But in 1974, narcotics researcher C. Robert Schuster, then at the University of Chicago, and his colleagues published the first evidence that vaccines could rev up the immune system against a different type of target-heroin. In a twist on their typical preventive role, these vaccines stop substances from satisfying an already-addicted user's cravings.

Normally, the immune system doesn't recognize heroin and other drugs as foes worthy of attack. That's because drug molecules are significantly smaller than the foreign proteins on bacteria and viruses that trigger the body to defend itself, says immunologist Michael Owens of the University of Arkansas for Medical Sciences in Little Rock. "In general, the cutoff in size for the immune system to recognize something as foreign will be about 10,000 daltons in weight. Most drugs of abuse are less than 500 [daltons]," he says. One dalton is about the weight of a single hydrogen atom.

To get the immune system fired up to fight heroin, Schuster and his team decided to make a vaccine by attaching heroin molecules to something that reliably triggers a response in healthy people and other animals. They used a protein from cows' blood. When the immune system senses the large, foreign protein with drug molecules piggybacked onto them, it pumps out a variety of antibodies, explains Owen. Some antibodies recognize pieces of the protein, but others home in on the drug. "The small drug molecules are just along for the ride," adds vaccine researcher Kim Janda of the Scripps Research Institute in La Jolla, Calif., but the immune system generates antibodies against them nonetheless.

After Schuster's team gave the vaccine to heroin-addicted rhesus monkeys that could self-administer the drug by pushing a lever, the animals did so significantly less often than they had previously. The researchers hypothesized that the vaccine somehow prevented the monkeys from getting high, taking away their incentive to keep using the drug.

However, notes Owens, the idea of vaccinating against illegal drugs didn't immediately catch on. Methadone, a drug that satisfies heroin's cravings without causing a high, was already in use in the 1970s for treating heroin addiction, and Schuster's team wasn't seeing as strong an effect with its vaccine. Over the next few decades, however, researchers began to see the value of Schuster's approach for treating other types of addiction. For example, vaccines to help smokers such as Harrison quit are now advancing through clinical trials.

One of these vaccines, called NicVax and manufactured by Nabi Biopharmaceuticals in Boca Raton, Fla., works by attaching multiple nicotine molecules to a protein taken from Pseudomonas aeruginosa, a species of bacteria that occasionally infects people. When a smoker lights up and draws the addictive drug into his or her bloodstream, antibodies glom on to individual nicotine molecules, explains Nabi scientist Henrik Rasmussen. As a result, the formerly tiny molecules morph into clumps made of nicotine and antibodies. Those clusters are far too big to cross the blood-brain barrier and stimulate the brain's feel-good centers, an action that normally cements nicotine's addictive power.

Smokers still experience the typical array of withdrawal symptoms, including cravings for cigarettes. But after learning that cigarettes are no longer satisfying, Rasmussen notes, people find that their cravings quickly decline. "People can still smoke, but they don't get the rush, they don't feel good, and they don't keep the addiction. You take away the reason they smoke," he says.

After the promising results in animals, Nabi scientists began a series of clinical trials 4 years ago to test whether NicVax is safe and effective in people. In 2005, the company released its latest results. Sixty-four smokers who were all interested in quitting participated in that trial. Some of them received various doses of the vaccine, delivered in a series of injections over 6 weeks. Others got a series of placebo shots.

Only 9 percent of the placebo group successfully laid off cigarettes for 30 days-a standard criterion that the U. S. Food and Drug Administration uses to define smoking cessation. However, of those smokers who got the highest vaccine dose, 33 percent passed the 30-day test of success. Moreover, even smokers who got the vaccine but didn't quit smoking, lit up significantly fewer cigarettes after the trial than smokers who got the placebo did.

Nabi is currently performing a similar trial with 300 smokers at nine sites across the country. The company expects to announce the results of this larger study in April or May, says spokesperson Tom Rathjen.

With the market hot for new smoking-cessation products, Nabi has some competition. Two other companies-Cytos Biotechnology of Zurich and Celtic Pharma of Hamilton, Bermuda-are developing their own versions of nicotine vaccines. Celtic is also working toward a vaccine based on similar technology to fight cocaine addiction. All these vaccines are currently going through clinical trials.

If these vaccines eventually head to the market, they'll be welcomed by addicted people, who currently have few effective treatment options, says vaccine researcher Janda. He and his team saw a similar possibility for people struggling against obesity.

However, these vaccines also have their disadvantages, says Owens. It can take weeks or months for an antibody to reach an effective concentration in the blood, so a patient's response to these treatments would be delayed. Furthermore, long-lasting antibodies aren't always desirable. For example, in the case of the antiobesity vaccine, doctors would need to end patients' treatments once they reached their target weight, rather than have patients continue to drop pounds.

With that in mind, Owens, Janda, and other researchers are crafting vaccines that work in a different way. Rather than prompting the body to create its own antibodies, these passive vaccines consist of custom-made antibodies to be pumped directly into a patient's bloodstream. They'd go to work right away against a habit-driving substance but then degrade and be cleared from the circulation in a few weeks, says Owens.

Janda's team is planning to develop a passive version of its antighrelin vaccine, while Owens and his colleagues have such vaccines in the works against a variety of addictive drugs, such as phencyclidine (PCP), methamphetamine, and cocaine. Each of these vaccines has had some success in limiting the amounts of drugs that addicted lab animals choose to self-administer.

More here




New York City Bans Science

This article is from last December but it is still very much to the point

The New York City Board of Health this week banned the use of trans fats by restaurants. The decision is directly traceable back to the "research" of Harvard University's Alberto Ascherio and Walter Willett, the promoters-in-chief of trans fats hysteria.

Now that the Board has deemed their dubious trans fats research suitable for dictating public policy, New Yorkers ought to hope that Ascherio and Willett don't press the Board to implement some of their other published research that is similar in "quality" to their trans fats work.

New Yorkers could, for example, see restaurants banned from serving potatoes, peas, peanuts, beans, lentils, orange juice and grapefruit juice. Ascherio-Willett reported an increase in the risk of heart disease among consumers of these foods in the Annals of Internal Medicine (June 2001). Although none of those slight correlations were statistically meaningful -- and, in all probability, were simply meaningless chance occurrences -- a similar shortcoming didn't seem to matter to the Board when it came to their trans fats research.

Indian restaurants could be banned from cooking with sunflower oil. Ascherio-Willett once found that consumers of Indian food cooked in sunflower oil were up to 3 times more likely to suffer heart attacks than consumers of Indian food cooked in mustard oil (American Journal of Clinical Nutrition, April 2004).

Sure it was only one study and even they acknowledged the need for more research -- but that didn't stop Ascherio-Willett from recommending the switch in cooking oils.

Red meat might disappear, too. Ascherio-Willett reported a 63 percent increase in the risk of type 2 diabetes associated with iron intake from red meat (American Journal of Clinical Nutrition, Jan. 2004). They didn't bother to verify how much iron from red meat any of the study subjects consumed and, therefore, don't actually have a firm basis for linking red meat consumption with the disease - but what the heck, they don't really know the quantity of trans fats consumed by any of those study subjects either.

It's not looking good for dairy products either. Ascherio-Willett reported in the Annals of Neurology (Dec. 2002) that consumption of dairy products was associated with an 80 percent increase in the risk of Parkinson's Disease among men. Although they concluded at the time that the finding needed further evaluation, why should the Board wait for more research? That could take forever. If the inconsistent and contradictory trans fats research doesn't require further evaluation, I can't imagine why it would be necessary for dairy products.

Regular (sugar-sweetened) soft drinks ought to be history as well. Willett linked them with weight gain and diabetes in women (Journal of the American Medical Association, Aug. 25, 2004). It didn't even matter that the same study also inexplicably linked diet soft drinks with a similar risk of diabetes.

It's really odd that when their research inadvertently debunks itself and other food myths, almost no one learns of it. And that's true for their trans fats research, as well. The Board's notice of its decision to ban trans fats tries to bolster its case by playing on popular misconceptions about saturated fat. The notice states that, "trans fat appears even worse than saturated fat." The Board apparently isn't familiar with the several Ascherio-Willett studies that fail to link saturated fat with heart disease and stroke.

The public's 30-year long fear of saturated fat and the Board's statement is, in fact, without a scientific basis. It's simply astounding that the Board can get away with exploiting one debunked myth to help propagate another.

Just to show that not all the Ascherio-Willett research is about simply banning foods - after all, it is possible that at some point the public will tire of being nannied - the Board may want to consider requiring restaurant patrons to order caffeinated coffee with every meal. One Ascherio-Willett study reported that the risk of type 2 diabetes was reduced by a statistically significant 54 percent among men who consumed 6 or more cups of coffee per day (Annals of Internal Medicine, Jan. 6, 2004). The Board might also want to mandate the daily consumption of pizza by men. Ascherio-Willett reported that men who consume more than 10 servings of pizza per week reduce their risk of prostate cancer by one-third (Journal of the National Cancer Institute, Dec. 1995).

It's not that either coffee or pizza is a proven "health" food - far from it - but the Board should consider their great distraction potential. Just as the ancient Roman emperors distracted citizens with bread and circuses while taking away their freedoms, the Board could easily distract New Yorkers with coffee and pizza as it dismantles consumer choice in restaurants bit by bit. Come to think of it, why is the Board's trans fats ban limited to restaurants? What about grocery stores and convenience shops? If trans fats are so bad, why should you be able to purchase food in a store that is too dangerous to be served in a restaurant?

The Board's trans fats ban has dramatically lowered the bar for scientific proof. It's such a sad spectacle that the Board of Health ought to be renamed the Bored of Science.

Source




Brain can repair nerve cells

The first firm evidence that the adult human brain can make new nerve cells has been discovered by scientists, raising the prospect of a new approach to treating neurological diseases such as Parkinson's and Alzheimer's.

While it has long been known that the brains of adult mice and rats are capable of producing new neurons from stem cells, previous research has been unable to establish whether a similar capacity exists in humans. A study led by Maurice Curtis of the University of Auckland in New Zealand has now shown that this exists. The findings are published in the journal Science.

Mark Baxter, Wellcome Trust senior research fellow at Oxford University, said: "This opens another direction by which we may discover ways to repair human brains that are damaged from injury or diseases, and underscores the importance of animal research in guiding biomedical research in humans."

Source

Journal abstract follows:

Human Neuroblasts Migrate to the Olfactory Bulb via a Lateral Ventricular Extension

By Maurice A. Curtis et al.

The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone (SVZ) cells reach the olfactory bulb in rodents. However, the RMS in the adult human brain has been elusive. Here we demonstrate the presence of a human RMS, which is unexpectedly organized around a lateral ventricular extension reaching the olfactory bulb (OB), and illustrate the neuroblasts in it. The RMS ensheathing the lateral olfactory ventricular extension, as seen by MRI, cell specific markers and electron microscopy, contains progenitor cells with migratory characteristics and cells which incorporate BrdU and become mature neurons in the OB.

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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? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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