Monday, May 07, 2007

Blindness cure for some?

A British hospital has made the world's first attempt to treat blindness with a revolutionary gene therapy. Surgeons at the Moorfields Eye Hospital in London operated on Robert Johnson, who was born with a rare sight disorder known as Leber's congenital amaurosis (LCA), which deteriorates with age. Mr Johnson, 23, who had genes inserted into one eye, could see only outlines during the day and very little at night before having the procedure yesterday. He is one of a dozen young patients selected for the first clinical trial to test the new therapy, which has already proved successful at restoring the sight of dogs in tests.

It will be months before the researchers know whether their work has been a success, but it is thought that the therapy could be used to treat a wide range of inherited sight disorders in adults and children. The LCA disorder is caused by a defect in a gene called RPE65, which prevents the light-sensitive layer of cells in the retina at the back of the eye from working properly. Usually these are cells that detect light, but in Mr Johnson's case they are damaged and prevent him from seeing properly.

The operation, conceived by researchers from University College London, involved injecting working copies of the defective gene into the back of the eye. Surgeons used a harmless virus or "vector" to carry the gene into the cells. It is hoped that the replacement genes will enable the retina to detect light - and eventually restore Mr Johnson's sight. The trial, funded by the Department of Health, involves 12 adults and children with LCA, for which there are currently no effective treatments.

During preliminary studies, the vision of dogs with the defect was restored to the extent that they were able to walk through a maze without difficulty; something they could not do before the treatment. The purpose of the Moorfields trial is to find out how safe and effective the intervention is for humans. The researchers hope that their work could lead to ways to treat more common sight problems, such as age-related macular degeneration, which affects about 250,000 Britons. Most previous gene therapies have been developed in an attempt to treat different types of cancer.

Before surgery, Mr Johnson told the BBC that he had mixed feelings. He said: "It's very difficult to say how I'm feeling. I keep ranging from extreme nervousness to a bit of excitement."

Professor Robin Ali, the lead researcher, based at the Institute of Ophthalmology, has spent 15 years working with colleagues developing the technique. He said yesterday: "I can't help feeling somewhat apprehensive. There is so much riding on it and we have all been waiting for a very long time." His colleague, James Bainbridge, who carried out the surgery, said that there was no guarantee that it would be a success. However, he added: "It is very encouraging that we can deliver genes to an extremely fragile site in the eye without complications."

The surgery required incredible precision. Robert Maclaren, the assistant surgeon, said yesterday that he was pleased with how things went. "We couldn't have asked for a better result," he said. Professor Ali added: "There are many forms of retinal degeneration, meaning the use of gene therapy treatments must be individually developed, then tested in a separate clinical trial specifically for that disease. "However, the results from this first human trial are likely to provide an important basis for many more gene therapy protocols in the future."


Left-handed women 'may not live as long'

A study suggests that women who are left-handed have a higher risk of dying, particularly from cancer and cerebrovascular disease - damage to an artery in the brain or an artery that supplies blood to the brain. While it could be a chance finding and the evidence is far from conclusive, numerous reports have associated left-handedness with various disorders and, in general, a shorter life span, Dutch researchers note in their report in the journal Epidemiology. "Left-handers are reported to be underrepresented in the older age groups, although such findings are still much debated," write Dr Made Ramadhani and colleagues from University Medical Centre Utrecht. It is estimated that about one in 10 people are lefties.

Among 12,178 middle-aged Dutch women the researchers followed for nearly 13 years, 252 died. When left-handed women were compared with the other women, and the data were adjusted for a number of potentially confounding factors, lefties had a 40 per cent higher risk of dying from any cause, a 70 per cent higher risk of dying from cancer, and a 30 per cent higher risk of dying from diseases of the circulatory system. Left-handed women also had a two-fold increased risk of dying from breast cancer, close to a five-fold increased risk of dying from colorectal cancer, and more than a three-fold higher risk of cerebrovascular mortality.

The underlying mechanisms remain elusive, although genetics and environmental factors may be involved, Ramadhani and colleagues suggest. Much of the research into handedness and mortality has been fuelled by the hypothesis that left-handedness is the result of an insult suffered during pre-natal life, which ultimately leads to the early death.



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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