Monday, September 17, 2007

New hope for blood cancer treatment

A WORLD breakthrough by Australian researchers - solving the riddle why some people do not respond to a "magic bullet" for chronic myeloid leukemia - holds new hope for treating a variety of cancers. Scientists have been puzzled why most patients have excellent responses to a recently developed drug, Glivec, but some do not respond well. Glivec is a tiny molecule targeting a specific enzyme which triggers leukemia in blood cells, blocking it and killing off the leukemic cells. The drug has had dramatic success in about two-thirds of patients but researchers have been baffled why other people don't respond as well.

However, work by researchers at the Hanson Institute and the Institute of Medical and Veterinary Science in Adelaide has found the reason. IMVS haematologist Professor Tim Hughes said Glivec specifically blocked the rogue enzyme in leukemia cells. "The development of 'targeted drugs' has been a huge development in anti-cancer therapy in the past decade, and we have been looking at how we can make further improvements in the field," he said. "The two-thirds of patients had great responses purely by switching off the enzyme, but we were mystified why one-third did not respond as well.

"We recently found the reason: the one-third just don't take up the drug into their leukaemic cells as efficiently, even though they are given exactly the same dose. "You can give two patients exactly the same dose but the amount that actually gets into the leukaemia cells will vary greatly. "Remarkably, the leukaemic cell itself determines how much of the drug is able to enter - the drug depends on the cell saying: 'Come inside and destroy me'."

Glivec is taken as a tablet which enters the bloodstream and finds its way to leukaemia cells, entering the cells and blocking the faulty enzyme. The discovery that some people's cells do not take it up as efficiently as others has led the Adelaide team to examine drug transport pathways into blood cells.

Researcher Deb White has now developed a blood test that can detect each patient's efficiency at taking up the drug. The test requires only 10ml of blood, takes just 24 hours and is being patented by the IMVS for expected worldwide commercial use. Patients identified as not being likely to respond well to standard doses of Glivec may be given higher doses or put on newer targeted drugs now coming into use, increasing survival rates.

The discovery that some people's cells do not accept cancer drugs as well as others has important implications for a range of cancers including some gastric and lung cancers. "We are moving towards individualised therapy, where we can predict what dose of a cancer drug each different person needs for maximum effect," Prof Hughes said. "I think with this tailored approach we may get a success rate greater than 90 per cent in chronic myeloid leukaemia."

The work has been published in the international journal Blood and already has attracted wide attention from haematologists.


Blueberry the super brain food?

Groan! Yet another bright-eyed hymn of praise to the miracle powers of fruits and berries. We would all be living to 150 if a fraction of it were true

BLUEBERRIES are being hailed by experts as a superfood that can slow the ageing process and even stall the onset of Alzheimer's disease. Researchers say a cup of blueberries a day will keep the mind young, with a study finding they can slow ageing in the brain. But, if a punnet of berries is too much to stomach, spinach, walnuts or grapefruit juice will also keep the mind healthy, the study found.

Professor James Joseph, from Tufts University in Boston, believes blueberries could be the key to a youthful mind. "We don't as yet understand fully the mechanisms involved in these behavioral/neuronal communication benefits of the berries," he said. "But our recent studies suggest that berries may actually reduce the signals created by inflammatory and oxidative stressors and increase the signals that are important in facilitating information concerned with learning and memory. "We've been testing on old rodents and have had positive results, but early trials on human brains are showing that people's reaction times can increase," he said.

A study by CSIRO researchers also found bush nuts and berries - which are a rich source of antioxidants - could help reduce the risk of cancers.



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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