Monday June 24, 2019

A Landmark Study Links Herpes 6 and 7 with Alzheimer’s Disease

The findings also showed multiple points of overlap between virus-host interactions and genes associated with Alzheimer's risk

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For the study, published in the journal Nature, the team engineered a hydrogel that can swell those lymphatic vessels.
For the study, published in the journal Nature, the team engineered a hydrogel that can swell those lymphatic vessels. (IANS)

Scientists have found up to two times higher level of human herpes virus among people with Alzheimer’s disease, suggesting the potential role of the viruses in the development of the progressive brain disorder.

Herpes virus causes contagious sores, most often around the mouth or on the genitals.

The study found unusually increased level of human herpesvirus named human herpesvirus 6A (HHV-6A) and human herpesvirus 7 (HHV-7 ) in the brains of the people with Alzheimer’s than those without the disorder.

“The hypothesis that viruses play a part in brain disease is not new, but this is the first study to provide strong evidence,” said Richard J. Hodes, Director from the US National Institutes of Health.

“Our work identified specific biological networks that offer new testable hypotheses regarding the role of microbial defense and innate immune function in the pathophysiology of Alzheimer’s,” said Joel Dudley from the Institute for Next Generation Healthcare at the Icahn School of Medicine at Mount Sinai.

alzheimers
Patient of Alzheimer’s. Pixabay

The findings also showed multiple points of overlap between virus-host interactions and genes associated with Alzheimer’s risk. Multiple viruses impact the biology of Alzheimer’s disease across domains such as DNA, RNA and proteins.

“If it becomes evident that specific viral species directly contribute to an individual’s risk of developing Alzheimer’s or their rate of progression once diagnosed, then this would offer a new conceptual framework for understanding the emergence and evolution of Alzheimer’s at individual, as well as population, levels,” Dudley explained.

In the study, published in the journal Neuron, the team initially performed RNA sequencing on four brain regions in more than 600 samples of postmortem tissue from people with and without Alzheimer’s to quantify which genes were present in the brain, and whether any were associated with the onset and progression of Alzheimer’s.

Also Read: Parkinson’s Identified Gene to Combat Alzheimer’s

Using different computational approaches, the team uncovered a complex network of unexpected associations, linking specific viruses with different aspects of Alzheimer’s biology.

They examined the influence of each virus on specific genes and proteins in brain cells, and identified associations between specific viruses and amyloid plaques, neurofibrillary tangles, and clinical dementia severity.

Further, they incorporated 800, RNA sequencing samples and observed a persistent increase of HHV-6A and HHV-7 in samples from individuals with Alzheimer’s. (IANS)

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Virtual Reality Can Identify Early Alzheimer’s More Accurately

The researchers are now working towards developing apps for detecting the disease and monitoring its progression

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In Alzheimer's disease, patients start losing memory. Pixabay

Virtual reality (VR) technology can identify early Alzheimer’s disease more accurately than ‘gold standard’ cognitive tests currently in use, says a study.

The findings, published in the journal Brain, highlight the potential of new technologies to help diagnose and monitor conditions such as Alzheimer’s disease.

“These results suggest a VR test of navigation may be better at identifying early Alzheimer’s disease than tests we use at present in clinic and in research studies,” said study lead author Dennis Chan, Professor at the University of Cambridge in Britain.

The researchers developed and trialled a VR navigation test in patients at risk of developing dementia.

For the study, the research team recruited 45 patients with mild cognitive impairment (MCI). Patients with MCI typically exhibit memory impairment.

They took samples of cerebrospinal fluid (CSF) to look for biomarkers of underlying Alzheimer’s disease in their MCI patients, with 12 testing positive. The researchers also recruited 41 healthy controls for comparison.

A lady suffering from Alzheimer’s. Flickr

All of the patients with MCI performed worse on the navigation task than the healthy controls. However, the study yielded two crucial additional observations.

First, MCI patients with positive CSF markers — indicating the presence of Alzheimer’s disease, thus placing them at risk of developing dementia — performed worse than those with negative CSF markers at low risk of future dementia.

Also Read- Avoid Eating Too Much Potato Chips During Pregnancy: Study

Secondly, the VR navigation task was better at differentiating between these low and high risk patients with mild cognitive impairment than a battery of currently-used tests considered to be gold standard for the diagnosis of early Alzheimer’s, the study said.

The researchers are now working towards developing apps for detecting the disease and monitoring its progression.

“We live in a world where mobile devices are almost ubiquitous, and so app-based approaches have the potential to diagnose Alzheimer’s disease at minimal extra cost and at a scale way beyond that of brain scanning and other current diagnostic approaches,” Chan said. (IANS)