Category Archives: Research

Health, Medical, Research, Science, United States

Eye tests may detect early onset of Alzheimer’s…

AMYLOID PLAQUES

Two new eye tests in America are being trialled that one day may help doctors to detect the very early stages of Alzheimer’s disease.

Newly released research has revealed that non-invasive retinal testing is now being trialled by scientists in the U.S. that could help flag up the condition by alerting clinicians to the presence of amyloid plaque deposits, a known biological marker of the disease.

Early stage testing could mean that patients are diagnosed or registered as high-risk up to twenty years before noticeable symptoms begin, helping patients get treatment before memory loss develops.

Scientists generally accept that amyloid plaques (a type of residual protein deposit) in the brain are a key marker of the disease.

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Neurologists have believed for a long time that there is a correlation between the amounts of amyloid in the eye and residual protein deposits in the brain. The argument for this correlating factor is a strong one because the retina is formed from the same tissue as the brain when a foetus is developing in the womb.

To confirm this theory, two tests have been developed and trials are currently underway. The tests are known as the Retinal Amyloid Index (by NeuroVision) and the Sapphire II (by Cognoptix).

Ocular based examinations through the years have been used to detect and diagnose Alzheimer’s at any early stage through methods such as optic nerve cupping, pupillary response to tropicamide dilation and ocular muscle movement. However, all have failed to withstand the test of time in terms of sensitivity and specificity.

Professor Keith Black is chairman of the Department of Neurosurgery at Cedars-Sinai Medical Centre in Los Angeles, and co-founder of NeuroVision. He says that if people are going to get Alzheimer’s they begin to develop the hallmarks, such as amyloid deposits, in their 50s.

Professor Black said:

… The key for having an effective treatment for AD is early detection. You want to prevent those brain cells from being killed or dying in the first place.

The Sapphire II test works by measuring the amount of photons (i.e. light particles) captured when scanning the eyes. The amount of photons captured directly correlates with the amount of amyloid in the eye.

Experts state that the Sapphire II is currently in phase one of two in clinical feasibility trials, and that phase three is expected to begin in 2014.

Approximately 800,000 people in Britain suffer from Alzheimer’s and other forms of dementia. The number of cases is predicted to double within a generation.

There is no cure for Alzheimer’s disease and existing drugs can only alleviate symptoms. The condition is diagnosed by memory tests and, in some cases, through brain scans.

Presently, the disease can only be confirmed by a post-mortem examination, which reveals the presence of harmful amyloid plaques in the brain.

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Health, Medical, Research, Science

British scientists unlock the secret DNA genetics of 30 cancers…

MUTATIONAL SIGNATURES

Scientists in the UK have achieved a ‘profound’ and major breakthrough in the fight against cancer that could lead to new treatments and possibly even its prevention.

Despite significant advances, very little is known about what triggers cancer, which kills around half the 325,000 Britons diagnosed with it each year.

But British scientists believe they have unlocked the DNA secrets of 30 of the most common forms of the disease. This will now bring us closer in understanding their causes.

In the biggest analysis yet of its kind, the researchers compared DNA from more than 7,000 cancer patients around the world. The cases included the most common forms, including breast, bowel, lung and prostate, which account for more than half of those diagnosed in Britain.

Cancer is caused by mutations in DNA. These mutations are caused by such things as tobacco in the case of lung or throat cancer, and excess ultraviolet light in the case of skin cancer. Researchers looked for patterns in the genetic code of the tumours made by these mutations.

Analysis of the 7,000 DNA samples revealed 21 patterns that between them were responsible for 30 cancers. Working out which food, drink, habit or other external factor causes them could lead to new ways of preventing the disease.

Knowing more about the genetics of cancer should also speed the search for new treatments – and some existing drugs might also work better in those whose tumours are caused by particular patterns.

Certain patterns in the tumour DNA were expected, such as the one caused by smoking; but others were surprising, including one believed to be caused by a protein that helps us fight infections.

Some of the patterns were only found in one type of cancer, while others, such as the marks left by ageing, were found in many different tumours.

Although further research may reveal more patterns – or ‘mutational signatures’ – the scientists, from the Wellcome Trust Sanger Institute near Cambridge, believe they have found most of them.

Professor Mike Stratton, the lead researcher, said:

… This compendium of mutational signatures and consequent insights into the mutational processes underlying them has profound implications for the understanding of cancer development, with potential applications in disease prevention and treatment.

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Health, Medical, Research, Science

New biological marker could detect Alzheimer’s disease ten years before symptoms appear…

EARLY TEST FOR DETECTING ALZHEIMER’S

Scientists are hoping that a new test could detect Alzheimer’s disease at least a decade before symptoms appear. That would pave the way for early treatment.

Researchers have discovered that a fall in levels of a certain type of genetic material could signal an increased risk and propensity of developing Alzheimer’s.

The biological markers are found within the cerebral spinal fluid (CSF) some 10 years before signs of dementia become apparent.

There are approximately 800,000 people with dementia in the UK, and current trends suggest that one in three people over 65 will die from the degenerative disease.

Presently, the only accurate method to diagnose the disease is by post-mortem neuropathological analysis, although other functional tests (such as memory and brain tests) can be used to determine whether drugs or other forms of treatment may help.

Researchers at Spain’s CSIC Institute of Biomedical Research of Barcelona believe they may have found a biological marker that could suggest the disease process is underway before symptoms start to appear.

Scientists found a drop in the content of mitochondrial DNA (mtDNA) –genetic material present in the energy centre of cells – in spinal fluid may be a sign for the disease.

They suggest that diminishing mtDNA levels reflect the reduced ability of mitochondria to power brain cells, thus triggering their death.

The drop in the concentration of mtDNA precedes the appearance of other recognised biochemical Alzheimer’s biomarkers, suggesting the process of Alzheimer’s disease starts earlier than previously thought and that mtDNA depletion may be one of the earliest predictors.

Researchers have previously been unable to detect the genetic material in spinal fluid, but they used a new technique to amplify tiny amounts. The research study was first reported in the journal Annals of Neurology.

The researchers at CSIC now hope other labs and hospitals will be able to replicate the results.

They say by finding a way to block the degeneration, clinicians may be able to diagnose and treat the disease before symptoms even appear.

Lead author Dr Ramon Trullas, said:

… If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer’s.

… The discovery of a fall in levels of a certain type of genetic material could signal an increased risk of developing Alzheimer’s.

… This discovery may enable us to search for more effective treatments that can be administered during the pre-clinical stage.

Dr Marie Janson of Alzheimer’s Research UK, the UK’s leading dementia research charity, said:

… Problems with mitochondria have already been linked to Alzheimer’s, which is why Alzheimer’s Research UK is currently funding research to further examine this link.

… This small study suggests that decreased mitochondrial DNA in cerebrospinal fluid may indicate the earliest stages of Alzheimer’s, but more work is needed to confirm this in larger groups of people.

… It would be useful to see further studies investigate changes in mitochondrial DNA over time, to determine how long before symptoms such changes might be detected.

… We know Alzheimer’s begins to develop before symptoms appear, and the ability to detect the disease at this stage is crucial for recruiting the right people for clinical trials of potential new treatments.

 

The discovery of a fall in levels of a certain type of genetic material could signal an increased risk of developing Alzheimer's disease. Image shows a CT scan of the brain of someone with Alzheimer's.

The discovery of a fall in levels of a certain type of genetic material could signal an increased risk of developing Alzheimer’s disease. Image shows a CT scan of the brain of someone with Alzheimer’s.

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