Walking restored in paralysed mice with spinal injury

Agencies
July 23, 2018

Boston, Jul 23: Scientists have successfully restored the ability to walk in mice that were paralysed after a spinal cord injury, an advance that may pave the way for similar treatments in humans.

Most people with spinal cord injury are paralysed from the injury site down, even when the cord is not completely severed.

Researchers at Boston Children's Hospital in the US provided insight into why the spared portions of the spinal cord do not keep working.

They also show that a small-molecule compound, given systemically, can revive these circuits in paralysed mice, restoring their ability to walk.

"For this fairly severe type of spinal cord injury, this is most significant functional recovery we know of. We saw 80 per cent of mice treated with this compound recover their stepping ability," said Zhigang He, from Boston Children's Hospital.

Many animal studies looking to repair spinal cord damage have focused on getting nerve fibres, or axons, to regenerate, or to getting new axons to sprout from healthy ones.

While impressive axon regeneration and sprouting have been achieved their impacts on the animals' motor function after a severe injury are less clear.

Some studies have tried using neuromodulators such as serotonergic drugs to simulate the spinal circuits, but have gotten only transient, uncontrolled limb movement.

Researchers took another approach, inspired by the success of epidural electrical stimulation-based strategies, the only treatment known to be effective in patients with spinal cord injury.

This treatment applies a current to the lower portion of the spinal cord; combined with rehabilitation training, it has enabled some patients to regain movement.

"Epidural stimulation seems to affect the excitability of neurons," said He.

"However, in these studies, when you turn off the stimulation, the effect is gone. We tried to come up with a pharmacologic approach to mimic the stimulation and better understand how it works," he said.

Researchers selected a handful of compounds that are already known to alter the excitability of neurons, and are able to cross the blood-brain barrier.

They gave each compound to paralysed mice in groups of 10 via intraperitoneal injection.

All mice had severe spinal cord injury, but with some nerves intact. Each group (plus a control group given a placebo) was treated for eight to ten weeks.

One compound, called CLP290, had the most potent effect, enabling paralysed mice to regain stepping ability after four to five weeks of treatment. Electromyography recordings showed that the two relevant groups of hind-limb muscles were active.

The animals' walking scores remained higher than the controls' up to two weeks after stopping treatment. Side effects were minimal.

"We are very excited by this direction. We want to test this kind of treatment in a more clinically relevant model of spinal cord injury," said He.

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News Network
February 4,2020

Toronto, Feb 4: People who text while walking face a higher risk of an accident than those listening to music or talking on the phone, a study has found.

The study, published in the journal Injury Prevention, found that smartphone texting is linked to compromised pedestrian safety, with higher rates of 'near misses', and failure to look left and right before crossing a road.

Researchers from the University of Calgary in Canada call for a more thorough approach to exploring the impact of distracted pedestrian behaviours on crash risk.

Worldwide, around 270,000 pedestrians die every year, accounting for around a fifth of all road traffic deaths, according to the researchers.

'Pedestrian distraction' has become a recognised safety issue as more and more people use their smartphones or hand held devices while walking on the pavement and crossing roads, they said.

The researchers looked for published evidence to gauge the potential impact on road safety of hand-held or hands-free device activities.

This included talking on the phone, text messaging, browsing and listening to music.

From among 33 relevant studies, they pooled the data from 14 -- involving 872 people -- and systematically reviewed the data from another eight.

The analysis showed that listening to music wasn't associated with any heightened risk of potentially harmful pedestrian behaviours.

Talking on the phone was associated with a small increase in the time taken to start crossing the road, and slightly more missed opportunities to cross the road safely.

The researchers found that text messaging emerged as the potentially most harmful behaviour.

It was associated with significantly lower rates of looking left and right before or while crossing the road, and with moderately increased rates of collisions, and close calls with other pedestrians or vehicles, they said.

Texting also affected the time taken to cross a road, and missed opportunities to cross safely, but to a lesser extent, according to the researchers.

The review of the eight observational studies revealed that the percentage of pedestrians who were distracted ranged from 12 to 45 per cent, they said.

It also found behaviours were influenced by several factors, including gender, time of day, solo or group crossing, and walking speed.

The researchers acknowledge "a variety of study quality issues" which limit the generalisability of the findings.

"Given the ubiquity of smartphones, social media, apps, digital video and streaming music, which has infiltrated most aspects of daily life, distracted walking and street cross will be a road safety issue for the foreseeable future," the researchers noted.

"And as signage and public awareness campaigns don't seem to alter pedestrian behaviour, establishing the relationship between distracted walking behaviour and crash risk is an essential research need," they said.

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Agencies
March 15,2020

Should you let your babies "cry it out" or rush to their side? Researchers have found that leaving an infant to 'cry it out' from birth up to 18 months does not adversely affect their behaviour development or attachment.

The study, published in the Journal of Child Psychology and Psychiatry, found that an infant's development and attachment to their parents is not affected by being left to "cry it out" and can actually decrease the amount of crying and duration.

"Only two previous studies nearly 50 or 20 years ago had investigated whether letting babies 'cry it out' affects babies' development. Our study documents contemporary parenting in the UK and the different approaches to crying used," said the study's researcher Ayten Bilgin from the University of Warwick in the UK.

For the study, the researchers followed 178 infants and their mums over 18 months and repeatedly assessed whether parents intervened immediately when a baby cried or let the baby let it cry out a few times or often.

They found that it made little difference to the baby’s development by 18 months.

The use of parent’s leaving their baby to ‘cry it out’ was assessed via maternal report at term, 3, 6 and 18 months and cry duration at term, 3 and 18 months.

Duration and frequency of fussing and crying was assessed at the same ages with the Crying Pattern Questionnaire.

According to the researchers, how sensitive the mother is in interaction with their baby was video-recorded and rated at 3 and 18 months of age.

Attachment was assessed at 18 months using a gold standard experimental procedure, the strange situation test, which assesses how securely an infant is attached to the major caregiver during separation and reunion episodes.

Behavioural development was assessed by direct observation in play with the mother and during assessment by a psychologist and a parent-report questionnaire at 18 months.

Researchers found that whether contemporary parents respond immediately or leave their infant to cry it out a few times to often makes no difference on the short - or longer term relationship with the mother or the infants behaviour.

This study shows that 2/3 of mum's parent intuitively and learn from their infant, meaning they intervene when they were just born immediately, but as they get older the mother waits a bit to see whether the baby can calm themselves, so babies learn self-regulation.

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Agencies
July 7,2020

The World Health Organization (WHO) is reviewing a report that suggested its advice on the novel coronavirus needs updating after some scientists told the New York Times there was evidence the virus could be spread by tiny particles in the air.

The WHO says the Covid-19 disease spreads primarily through small droplets, which are expelled from the nose and mouth when an infected person breaths them out in coughs, sneezes, speech or laughter and quickly sink to the ground.

In an open letter to the Geneva-based agency, 239 scientists in 32 countries outlined the evidence they say shows that smaller exhaled particles can infect people who inhale them, the newspaper said on Saturday.

Because those smaller particles can linger in the air longer, the scientists - who plan to publish their findings in a scientific journal this week - are urging WHO to update its guidance, the Times said.

"We are aware of the article and are reviewing its contents with our technical experts," WHO spokesman Tarik Jasarevic said in an email reply on Monday to a Reuters request for comment.

The extent to which the coronavirus can be spread by the so-called airborne or aerosol route - as opposed to by larger droplets in coughs and sneezes - remains disputed.

Any change in the WHO's assessment of the risk of transmission could affect its current advice on keeping one-metre physical distancing. Governments, which also rely on the agency for guidance policy, may also have to adjust public health measures aimed at curbing the spread of the virus.

"Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence," Benedetta Allegranzi, the WHO's technical lead for infection prevention and control, was quoted as saying in the New York Times.

WHO guidance to health workers, dated June 29, says that SARS-CoV-2, the virus that causes Covid-19, is primarily transmitted between people through respiratory droplets and on surfaces.

But airborne transmission via smaller particles is possible in some circumstances, such as when performing intubation and aerosol-generating procedures, it says.

Medical workers performing such procedures should wear heavy-duty N95 respiratory masks and other protective equipment in an adequately ventilated room, the WHO says.

Officials at South Korea's Centers for Disease Control said on Monday they were continuing to discuss various issues about Covid-19, including the possible airborne transmission. They said more investigations and evidence were needed.

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