Monday, August 06, 2007

Heart discovery to save millions of lives

AUSTRALIA'S top heart specialists believe they have found a treatment to stop heart disease in its tracks, potentially saving millions of lives worldwide. Experts from the Victor Chang Cardiac Research Institute and Sydney's St Vincent's Hospital will today unveil the groundbreaking discovery which involves using adult stem cells from patients to repair their own hearts. The world-first treatment has been shown to generate new blood vessels and repair dead tissue in the heart. Importantly, the changes appear to be permanent.

Heart disease is the world's biggest killer, claiming 17 million lives a year. In Australia, there are 3.5 million sufferers and 50,000 die annually, 35 per cent of all deaths.

The new treatment involves injecting patients with a hormone to release beneficial stem cells from their bone marrow into their bloodstream. Then the patients are put on a treadmill to encourage the cells to travel to the heart, where they create new blood vessels to restore circulation and boost heart function. Evidence has also shown the hormone -- Granulocyte Colony Stimulating Factor -- can also actively rescue and protect struggling heart muscles from dying. It has passed safety tests and entered the second phase of human trials last week.

Professor David Ma, head of blood and stem-cell research at St Vincent's, said the development of the treatment was amazing. "It's amazing because a few years back when we started this study our whole hypothesis was different," he said. "It's quite exciting -- it's given us a new direction to attack the situation. "Because of the study results and more evidence coming out in the past couple of years, we have changed our emphasis." He explained how the hormone could stimulate blood vessels to grow in the heart as well as protecting and rescuing heart muscles from dying.

Prof Ma said the findings were significant because heart disease was already a huge problem in developed nations, like the US and Britain, but was also rapidly growing in developing countries, like India and China.

Professor Bob Graham, head of the Victor Chang Cardiac Research Institute, said the early findings were "very promising". Speaking from the US, where he was meeting international specialists last week, Prof Graham said: "At the moment we are restricting it to the most severe patients but if it works and is safe for those patients, hopefully we can broaden it. "The nice thing about this trial is that the drug is already on the market -- although it hasn't been used for this application." The hormone is commonly used to help cancer patients recover after chemotherapy.

Dr Sharon Chih, cardiology research fellow at St Vincent's, is co-ordinating the trial. Forty patients with severe angina -- or chest pain from a lack of blood and oxygen supply to the heart -- are being tested with the treatment against a placebo in a double-blind, crossover trial. They will be treated for three weeks and checked with MRI scans to assess the treatment's effectiveness. Poor diet and lack of exercise, as well as smoking, are major contributors to heart disease in Western countries. But the incidence is spreading to developing nations.


Nerve gas antidote made by goats

Scientists have genetically modified goats to make a drug in their milk that protects against deadly nerve agents such as sarin and VX. These poisons are known collectively as organophosphates - a group of chemicals that also includes some pesticides used in farming. So far, the GM goats have made almost 15kg of a drug which binds to and neutralises organophosphate molecules. Details appear in Proceedings of the National Academy of Sciences journal.

The drug, called recombinant butyrylcholinesterase, could be used as a protective "prophylactic" drug and also to treat people after exposure to nerve gas. The US Department of Defense is funding the development effort by biotech firm PharmAthene to the tune of $213m. It regards the drug as a promising way to protect its troops against exposure to nerve agents on the battlefield. Butyrylcholinesterase could also be stockpiled for use in the event of a terrorist attack on a city with chemical weapons.

It is an enzyme that is made in small quantities by the human body. The compound can be purified from blood, but the yields are poor. However, the team at PharmAthene has been able to produce butyrylcholinesterase in large, commercial quantities and, the company says, at a reasonable cost. "It is a very difficult molecule to produce. There is a long history of people trying to produce this in everything from insects to yeast to bacteria and mammalian cells," said Dr Solomon Langermann of PharmAthene, a co-author on the PNAS paper. "None of them has been able to produce anything beyond milligram amounts. In the goat, we can make two or three grams per litre."

The researchers inserted DNA for making the human form of butyrylcholinesterase into a "vector" molecule. This vector is then introduced into a goat embryo. This allows the human gene to be incorporated into the goat's DNA sequence. The resulting female animals, all healthy, produced large quantities of butyrylcholinesterase in their milk.

The high yields are partly down to "control elements" - stretches of DNA added, along with the human gene, to the vector molecule. These control elements regulate how much of the enzyme the goat produces and ensure that most of it is produced in the milk, rather than in other tissues.

Once the enzyme was purified from milk, the scientists injected it into guinea pigs, and saw that it remained active in the bloodstream. The commercial name given to the butyrylcholinesterase enzyme is Protexia. Dr Langermann said that Protexia was more effective than the combination of the drugs atropine and 2-PAM currently carried by soldiers for protection against nerve agents. "Those (older) drugs get cleared from the blood very rapidly. Even if the soldier were to survive, they would have very severe neurological damage," he told BBC News. "With Protexia, you would survive and be able to go back on the battlefield."

It is also effective against a variety of different organophosphate poisons. The product is still several years from entering use; it needs to pass a safety trial and seek approvals from the US government.



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.


No comments: