Science

Share this

The Ebola Virus and the related Marburgvirus have been diverging for over 16 million years, according to a recent study by the University of Buffalo. Although filoviruses were once thought to date back only 10,000 years, new research using more reliable dating methods has shown that the origins of the virus go much deeper than the beginnings of large-scale human agriculture.

“An understanding of the timescale of evolution is critical for comparative virology but remains elusive for many RNA viruses,” wrote the authors of the report.

Experts had at one time believed that filoviruses came about around 10,000 years ago, and coincided with the rise in human agriculture.

According to the research of Professor Derek Taylor and others at the University of Buffalo, the viruses date back to the Miocene Epoch–16 to 23 million years ago.

Read more: Ebola Genome Sequencing Being Undertaken by Harvard Team to Discover Weaknesses in Virus Genome, Which Has Already Mutated Hundreds of Times 

“Filoviruses are far more ancient than previously thought,” said Taylor. “These things have been interacting with mammals for a long time–several million years.”

The science of measuring the age of diseases is still developing. Previous dating relied on mutation rates.

“Age estimates based on mutation rates can severely underestimate divergences for ancient viral genes that are evolving under strong purifying selection,” the researchers wrote in their report.

“Paleoviral dating, however, can provide minimum age estimates for ancient divergence, but few orthologous paleoviruses are known within clades of extant viruses.”

“For example, ebolaviruses and marburgviruses are well-studied mammalian pathogens, but their comparative biology is difficult to interpret because the existing estimates of divergence are controversial.”

The researchers looked at the paloviral elements of two genes in the ebolavirus family, and found that ebolavirus diverged from marburgvirus in the early Miocene.

The scientists searched within the viral genes in rodents preserved through fossilization.

“These rodents have billions of base pairs in their genomes, so the odds of a viral gene inserting itself at the same position in different species at different times are very small,” Taylor said. “It’s likely that the insertion was present in the common ancestor of these rodents.”

The knowledge may help scientists create better vaccines for Ebola victims. It could also help create programs that better identify emerging pathogens by providing insight into which host species serve the virus as “reseviors” for related pathogens.

“When they first started looking for reservoirs for Ebola, they were crashing through the rainforest, looking at everything–mammals, insects, other organisms,” said Taylor. The more we know about the evolution of filovirus-host interactions, the more we can learn about who the players might be in the system.”

By Andrew Stern

Photo: NIAID

Share this

According to a new report by scientists at the University of Bristol, additional daylight savings could have public health benefits. The study looked at daylight savings increases as a possible public health intervention, and found evidence that an increase would increase physical activity among children.

“This study provides the strongest evidence to date that, in Europe and Australia, evening daylight plays a role in increasing physical activity in the late afternoon and early evening – the ‘critical hours’ for children’s outdoor play. Introducing additional daylight savings measures would affect each and every child in the country, every day of the year, giving it a far greater reach than most other potential policy initiatives to improve public health,” said Dr. Anna Goodman, Lecturer at the London School of Hygiene & Tropical Medicine at the University of Bristol and one of the researchers on the project.

The study, “Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively measured physical activity among 23,000 children from 9 countries,” was authored by the University of Bristol’s Anna Goodman, Angie S Page and Ashley R Coope, and was published in the International Journal of Behavioural Nutrition and Physical Activity. The study was funded by the UK National Prevention Research Initiative, and Anna Goodman’s contribution was funded by the National Institute for Health Research.

In the research, over 23,000 children aged 5-16 years were studied in nine countries (England, Australia, USA, Norway, Denmark, Estonia, Switzerland, Brazil and Madeira, and Portugal). The scientists looked at physical activity data before and after the clocks changed. The data was matched to the time of sunset, as well as daily precipitation, humidity, wind speed, temperature and other weather characteristics.

Independent of weather factors, longer evening daylight was found to be associated with a modest but not insignificant increase in daily physical activity. The associations were consistently observed in five European, four English and two Australian samples, where children added two minutes of physical activity per day as a result of longer evening sunlight.

Although two minutes may at first seem a small amount of time, two minutes per child in a large population can amount to millions of minutes of extra physical activity per day, the researchers noted.

“We therefore conclude that, by shifting the physical activity mean of the entire population, the introduction of additional daylight saving measures could yield worthwhile public health benefits,” the researchers wrote.

“While the introduction of further daylight savings measures certainly wouldn’t solve the problem of low physical activity, we believe they are a step in the right direction,” said senior author Ashley Cooper, Professor of Physical Activity and Public Health at the University of Bristol.

By Heidi Woolf

Share this

In a world first, movement and sensation have been returned to a man who was paralyzed four years ago. After a pioneering cell transplant using special cells that naturally regenerate, 40-year-old Darek Fidyka is walking again.

“When you can’t feel almost half your body, you are helpless, but when it starts coming back it’s like you are born again,” said Fidyka, who is now able to walk with the support of a frame. Fidyka said the restoration of his legs was “an incredible experience.”

Fidyka, now 40, was paralyzed after being stabbed multiple times in his back during an attack in 2010. He remained paralyzed with no signs of recovery for two years after the accident, despite extensive physiotherapy.

Scientists took olfactory ensheathing cells (OECs) from one of Fidyka’s olfactory bulbs, grew the cells in culture, and micro-injected about 500,000 cells (an amount that can be conceptualized as a drop of liquid) into the gap in Fidyka’s spinal chord to stimulate repair and regrowth. The team made about 100 micro-injections above and below the injury site.

OECs are part of the sense of smell. They are nerve fibers that constantly regenerate.

The treatment was successful after about three months. Fidyka began putting on muscle in his thigh. After six months, Fidyka took his first steps along the parallel bars.

Two years after treatment, Fidyka can walk outside using a frame. Bladder, bowel and sexual function has also partially recovered.

The scientists involved believe that OECs provided a pathway whereby fibers around the injury site can reconnect–essentially using the nerve grafts to bridge the gap.

“You are making history now,” lead scientist Prof Geoff Raisman, chair of neural regeneration at University College London’s Institute of Neurology, told Fidyka. “To me, this is more impressive than a man walking on the moon.”

“We’re at the point now of where Barnard was with the first heart operation,” said Chef David Nicholls, who funded a great deal of the research through the organization UK Stem Cell Foundation (UKSCF), which Nichols founded after his son was paralyzed in a swimming accident in 2003.

“It’s amazing to see how regeneration of the spinal cord, something that was thought impossible for many years, is becoming a reality,” said Dr Pawel Tabakow, consultant neurosurgeon at Wroclaw University Hospital, who led the Polish research team.

The scientists are currently undertaking the next leg of their research: a controlled clinical trial involving 10 patients.

“The first patient is an inspirational and important step, which brings years of laboratory research towards the clinical testbed,” said Sir Richard Sykes, chair of the UK Stem Cell Foundation. “To fully develop future treatments that benefit the 3 million paralysed globally will need continued investment for wide scale clinical trials.”

The research was supported by the Nicholls Spinal Injury Foundation (NSIF) and the UKSCF, and the most recent report on Fidyka was published in Cell Transplantation.

By Heidi Woolf