HEALTH

Weekender

Common cold stopped by experimental approch

SCIENTISTS think they have found a way to stop the common cold and closely related viruses which can cause paralysis.
Instead of trying to attack them directly, the researchers targeted an essential protein inside our cells which the viruses need to replicate.
The approach gave “complete protection” in experiments on mice and human lung cells.
However, the US-based researchers are not ready for trials in people.
The common-cold challenge
Tackling the common cold has been a massive problem in medicine.
Most colds are caused by rhinoviruses, but there are around 160 different types and they mutate so easily they rapidly become resistant to drugs, or learn to hide from the immune system.
This has led to the idea of “host-directed therapy” – essentially making our bodies inhospitable for the cold viruses.
An individual virus does not have everything it needs to replicate. Instead, it is dependent on infecting another cell and stealing some of the parts inside.
It is why scientists still argue whether viruses are truly alive.
A team at Stanford University and the University of California, San Francisco, found one of the components which the viruses were dependent upon.
Viral dependency
Scientists started with human cells and then used gene-editing to turn off instructions inside our DNA one-by-one.
These modified cells were then exposed to a range of enteroviruses – this includes the rhinoviruses which cause the common cold, and more dangerous viruses that are closely related to polio and can cause paralysis.
All the viruses were unable to replicate inside cells which had the instructions for a protein (called methyltransferase SETD3) switched off.
The scientists then created genetically modified mice which were completely unable to produce that protein.
“Lacking that gene protected the mice completely from viral infection,” associate professor Jan Carette, from Stanford, told the BBC.
“These mice would always die [without the mutation], but they survived and we saw a very strong reduction in viral replication and very strong protection.”
The protein these viruses were dependent upon normally has a role in the intricate “scaffolding” which organises the inside of the body’s cells, called the cytoskeleton.
The findings, published in the journal Nature Microbiology, showed the genetically modified mice were healthy, despite lacking the protein for their whole lives.
When do we get a cure?
The plan is not to produce genetically modified humans, but to find a drug which can temporarily suppress the protein, and provide protection.
“We have identified a fantastic target that all enteroviruses and rhinoviruses require and depend on. Take that away and the virus really has no chance,” said Prof Carette.
He added: “This is a really good first step – the second step is to have a chemical that mimics this genetic deletion.
“I think development can go relatively quickly.”
Exactly what role the protein plays in the viral replication is still uncertain, and will require further research.
For most people the common cold is more of an inconvenience than a threat to their health, but in asthmatics it can make their symptoms much worse and some of the enteroviruses can causes paralysis if they spread to the brain.
Prof Jonathan Ball, a virologist at the University of Nottingham, who was not involved in the work, said the study was “neat” but scientists would need to be certain the approach was safe.
“There is increasing interest in developing treatments that target these host proteins, because it can potentially overcome virus mutation – one of the major barriers to developing effective broadly active antivirals.
“But of course, viruses are very adaptable and it is conceivable that even a host-targeting treatment might not keep them at bay for long.” –BBC


Physical fitness linked to better brain function

THE largest and most detailed study of its type concludes that there are links between physical fitness and improved cognitive performance. The researchers also show that this boost in mental powers is associated with white matter integrity.
Over recent years, there has been a great deal of research into how bodily fitness might influence the mind.
For instance, studies have concluded that physical fitness can reduce the risk of dementia, relieve depressive symptoms, and more.
There is also evidence that physical activity boosts the cognitive performance of healthy individuals, people of different ages, and participants with cognitive impairments.
Similarly, some studies have shown positive links between physical fitness and changes in brain structure.
The authors of the latest study in this field, who published their findings in Scientific Reports, note that previous studies had certain limitations.
As an example, researchers could associate low levels of physical fitness with higher blood pressure. If a study finds that high physical fitness has links with cognitive abilities, scientists could argue that in fact, it is lower blood pressure that boosts cognitive power.
The same could apply for several factors that have links with fitness, such as body mass index (BMI), blood glucose levels, and education status.
Also, most studies concentrate on only one marker of mental performance at a time, such as memory.
As the authors of the current study explain, “studies investigating associations between [physical fitness], white matter integrity, and multiple differential cognitive domains simultaneously are rare.”
A fresh look at fitness and the brain
The latest experiment, carried out by scientists from University Hospital Muenster in Germany, attempts to fill in some of the gaps. Using a large sample of healthy people, the scientists retested the links between physical fitness, brain structure, and a wide range of cognitive domains.
They also wanted to ensure that they accounted for as many confounding variables as possible. Additionally, the scientists wanted to understand whether the link between cognitive ability and physical fitness was associated with white matter integrity.
White matter in the brain relays messages between disparate parts of the brain and coordinates communication throughout the organ.
To investigate, the researchers took data from the Human Connectome Project, which includes MRI brain scans from 1,206 adults with an average age of 28.8.
Some of these participants also underwent further tests. In total, 1,204 participants completed a walking test in which they walked as quickly as they could for 2 minutes. The researchers noted the distance.
A total of 1,187 participants also completed cognitive tests. In these, the scientists assessed the volunteers’ memory, reasoning, sharpness, and judgment, among other parameters.
Overall, the researchers showed that individuals who performed better in the 2-minute walking test also performed significantly better in all but one of the cognitive tasks.
Importantly, this relationship was significant even after controlling for a range of factors, including BMI, blood pressure, age, education level, and sex.
The researchers also associated this cognitive improvement with higher levels of fitness with improvements in the structural integrity of white matter.
The current study has many strengths, not least the extensive database of MRIs. Dr. Repple explains that “normally when you are dealing with MRI work, a sample of 30 is pretty good, but the existence of this large MRI database allowed us to eliminate possibly misleading factors and strengthened the analysis considerably.”
However, because researchers carried out the tests at one point in time, it is not possible to see how fitness and cognitive ability changes over time.
It is also not possible to say that becoming fitter causes a boost in cognitive ability.
Future studies will need to ask whether increasing an individual’s level of fitness also increases cognitive ability. – Medical News Today