Saturday, July 14, 2007

Protein to fight tooth decay

A MOUTHWASH based on a protein found in children with kidney failure could help protect young teeth. Pediatric dentist Kerrod Hallett hopes to start trials of the mouthwash in five to 12-year-olds at Gold Coast and Townsville schools next month. The mouthwash is based on a protein called urease, found in high levels in the saliva of children with chronic renal failure. "We've noticed in these children over a number of years that their teeth were not decayed," Associate Professor Hallett said. "We believe there's something in their saliva that's stopping germs from growing in their mouths and we think the material responsible is a by-product of urea called urease."

Because the children's kidneys fo not function properly, they are unable to excrete urea from the body effectively. "The body's got to get rid of urease somehow so the next best avenue is to get rid of it in saliva," Professor Hallett said.

He has been working with Oral Biotechnologies, a company in Portland, Oregon, to produce the mouthwash containing a synthetic version of urease, fluoride and sodium hypochlorite to mask the taste. A human trial of 250 children at Musgrave Hill State School on the Gold Coast and Vincent State School in Townsville will begin once Professor Hallett receives the first batch of mouthwash. Half will receive the experimental mouthwash once a day by a dental therapist for a month and half will be given a placebo rinse.

Professor Hallett said researchers will test the plaque of the children's teeth before treatment and 120 days afterwards for levels of a bacteria known as mutans streptococci (MS). MS is found in high levels in children with dental decay. The State Government has provided $300,000 over three years for the trial.

Professor Hallett said about half of all Queensland children had varying degrees of tooth decay when they started school. About 2000 pre-schoolers a year in Queensland need a general anaesthetic before the age of four to remove decayed baby teeth.


Gene therapy reported to wipe out pancreatic cancer in mice

A newly engineered therapy, which embeds a gene in pancreatic cancer cells, shrinks or eradicates tumors, inhibits the deadly disease's spread and prolongs survival in mice, researchers say. "This vehicle, or vector, is so targeted and robust. that it can be used for therapy and perhaps for imaging" of tumors, said MienChie Hung of The University of Texas M. D. Anderson Cancer Center in Houston, Texas. Hung is senior author of a study on the therapy, published in the July 9 edition of the research journal Cancer Cell.

The system is an example of gene therapy -- the insertion of genes into the body in order to correct some genetic malfunction. Gene therapy is still in its infancy despite some early successes; the U.S. Food and Drug Administration has not yet approved any such therapies.

Researchers call the new system for pancreatic cancer a versatile expression vector, nicknamed VISA. It includes a gene known to kill cancer cells, along with molecular components that target the gene's activity to the disease tissue. The components are all packaged in a fatty ball called a liposome, which is delivered intravenously.

"We are working to bring it to a clinical trial," said M. D. Anderson's James Abbruzzese, a member of the research team. He estimates it will take a year or two to complete FDA requirements for a Phase I clinical trial, which could serve as a first step to approval.

About 37,000 cases of pancreatic cancer are diagnosed annually in the United States. Early diagnosis is extremely hard, so the disease is often discovered at a late stage after it already has spread, or metastasized. Fewer than four percent of patients survive five years after diagnosis, one of the lowest cancer survival rates.

In a test of the therapy against two aggressive lines of pancreatic cancer in two different types of mice, researchers loaded the VISA system with a mutant version of a gene named Bik. The gene produces a protein molecule that naturally forces cancer cells to kill themselves. The team created the more lethal mutant and named it BikDD. Untreated mice in both experiments all died within 40 days. The VISABikDD mice lived much longer, researchers said, with at least half surviving for 14 months with no detectable sign of cancer recurrence.



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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