New blood test to tell how long will you live

 

 

 Researchers claim to have developed a new controversial `lifespan` test that can tell how long a person will live by determining the rate of ageing.
The blood test estimates how fast someone is ageing by measuring the length of microscopic structures at the ends of each chromosome called telomeres, which keep each chromosome from falling apart when cells divide

Telomeres shorten after each cell division and animal studies have shown that a high percentage of short telomeres in blood cells is associated with a shorter-than-normal life expectancy, which is why blood tests could provide a guide to ageing and life expectancy.

More than 100 Britons have already taken the revolutionary blood test to see how fast they are ageing, and which might be used in the future to indicate statistically how long they have got left to live,

The company behind the test believes that thousands will further take the 650 pounds blood check in UK next year, and millions more worldwide will be tested by the end of the decade.

It also expects the test to be used as part of the standard medical check-up required by insurance companies, just as they now ask about family history of disease and whether someone is a smoker or obese.

"We consider that this will become as standard a medical diagnostic test as cholesterol testing is now," said Stephen Matlin, chief executive of Life Length, which is based in Madrid.

"If you look at cholesterol testing since the early 1980s, in a period of 15 years testing volume went from nothing to about 100 million a year,"
However, some experts have warned that there is still not enough known about telomere testing to provide people with any meaningful medical advice, and one Nobel prize-winner has warned that 99 per cent of people who take the test will not gain any benefit.

"Today there are 500 million cholesterol tests a year. If we do one per cent of this, we are doing well. We hope to be testing millions of people by 2020,"
The company plans to lower the price of the test by 20 per cent a year for the next five years so that it costs no more than about 65 pounds by 2017, bringing it within the price range of millions of new customers.

Now, drug to reverse `permanent` deafness

Harvard scientists have developed a drug which they claim can cure permanent deafness by stimulating the inner ear.

The drug, codenamed LY411575, works by triggering the regeneration of sensory hair cells.
Until now it has not been possible to restore the cells once they have been lost due to factors such as loud noise exposure, infection and toxic drugs

This type of deafness, often suffered by rock musicians and DJs, is generally assumed to be irreversible.

Scientists succeeded in partially restoring hearing to mice that had been deafened by loud noise and believe the research could lead to effective treatments for acute noise-induced deafness in humans.

The tiny sensory hairs in the cochlea are vital to hearing. Sound vibrations transferred from the eardrum shake the hairs, causing nerve messages to be fired to the brain.

Without the hairs, the hearing pathway is blocked and no signals are received by the brain`s auditory centre.

While birds and fish are capable of regenerating sound-sensing hair cells, mammals are not.

The new approach involves reprogramming inner ear cells by inhibiting a protein called Notch.

Previous laboratory research had shown that Notch signals help prevent stem cells in the cochlea transforming themselves into new sensory hair cells.

The new drug suppresses Notch. Mice with noise-induced hearing loss generated functioning sensory hair cells after the drug was injected into their damaged cochleas.

"We show that hair cells can be regenerated from the surrounding cells in the cochlea," lead researcher Dr Albert Edge, from Harvard Medical School in the US, said.

"These cells, called supporting cells, transdifferentiate into hair cells after inhibition of the Notch signalling pathway, and the new hair cell generation results in a recovery of hearing in the region of the cochlea where the new hair cells appear,"

"The significance of this study is that hearing loss is a huge problem affecting 250 million worldwide," Edge added.

A green fluorescent protein was used to label the newly generated hair cells. Electronic measurements of auditory brainstem responses confirmed that three months after treatment, lost hair cells had been replaced and were working.

Improvement in hearing was seen over a wide range of frequencies.

"The missing hair cells had been replaced by new hair cells after the drug treatment, and analysis of their location allowed us to correlate the improvement in hearing to the areas where the hair cells were replaced,"