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Gene therapy restores eyesight

Gene therapy restores eyesight
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Restoring sight to people suffering from a rare kind of eye disease – researchers at the University of Oxford have just published the results of a trial, which suggests that tinkering with people’s genes can stop the condition – choroideremia – from causing blindness.

The aim of the new therapy is to replace a defective gene with a healthy one. The defective gene causes the pigment cells in the retina to stop working and eventually die. As the disease progresses, the retina begins to shrink, leading to blindness.

The operation involves detaching the patient’s retina and injecting a virus containing the healthy gene under the retina.

“The choroideremia gene is important for making a protein known as REP1 and when that protein is deficient in the retina the cells gradually die throughout life and they die from the outside in, so patients develop tunnel vision, it gets narrower and narrower and eventually it goes. The concept of gene therapy is to put that protein back into those cells by using a virus to carry the missing gene,” says Robert MacLaren, Professor of Ophthalmology at Oxford University.

Researchers have treated nine patients so far.

It is estimated that the disease affects one in every 50,000 people. Doctors hope the procedure could eventually be used as a therapy for retinitis pigmentosa – a far more common eye disease which affects hundreds of thousands of people in the world.

“As a result of the trial there is very real and tangible hope that I will continue to be able to see and that is just a massive advance and has actually made a significant difference to the way I approach my life now,” says gene therapy trial patient Toby Stroh.

According to says Jonathan Wyatt, another trial patient: “I can now read an iPad without having it magnified, which is amazing.”

Researchers say that, while it’s too soon to say if the benefits of the gene therapy will last, the improvement in the eyesight of the patients who took part in the trial has remained unchanged for two years, without any side effects.

Understanding why bees are disappearing

Better understanding what is causing the collapse of bee colonies around the world.

Scientists in Australia are fitting thousands of honey bees with tiny sensors as part of a project that will track the movements and habits of several generations of bees. The aim is to shed light on the causes of a condition known as Colony Collapse Disorder.

The sensors are fitted in open air, or, for better results, inside a lab.

“Bees are very sensitive to heat. So we bring them to the lab, we chill them down, then we attach the sensors while they’re sleeping. This is just like carrying a little backpack,” says Paulo de Souza, researcher at the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

The bees are placed in a fridge, which sends them to sleep. The sensors are then carefully placed onto their backs before they are returned to the hive.

About a third of the food regularly eaten by humans requires pollination. It’s hoped the sensors will provide farmers and fruit growers with an insight into bee behaviour, the impact of pesticides and what conditions are best for productivity.

“For the first time we’ll actually know where they go,” says apple grower, John Evans.

“Because in the past, we see a white box and we see bees entering and leaving but what they do in the meantime, we’ve no idea.”

The next stage of the project is to build smaller sensors, which could be attached to insects such as fruit flies, mosquitoes and tiny winged insects.