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Rectal breathing: Ventilation alternative increases blood oxygen levels in pigs



Flushing trillions of tiny oxygen bubbles through the rectum increases blood oxygen in pigs and could be an alternative to ventilation for people with damaged lungs


15 December 2021

Pigs recover from low blood oxygen levels after fatty bubbles are introduced into their rectum

Tyler Stableford Photography/Getty Images

The injection of trillions of tiny oxygen bubbles into the rectum has been shown to raise blood oxygen levels and lower carbon dioxide levels in pigs whose lungs were damaged by smoke. The researchers are now seeking the go-ahead to do safety tests of the procedure in healthy volunteers.

The approach could help people, whatever the cause of their low blood oxygen. For instance, people with covid-19 often come into hospitals with very low oxygen levels, says Robert Scribner at Respirogen, a Colorado-based company set up to commercialise the approach.

“This could be a good bridging therapy to raise the oxygen saturation in those patients,” he says, and it might mean they don’t need to be put on a ventilator, which can have many harmful side effects.

While the pig tests lasted only a few hours, the treatment should work over longer periods, says team member Keely Buesing at the University of Nebraska Medical Center.

“There’s no reason why you couldn’t just cycle these oxygen microbubbles in and out of the body,” she says. “With the colonic delivery method, it could in theory be a long-term sustaining therapy for severely injured patients, we just haven’t tested it out to those time points.”

The key to the approach is that the oxygen is enclosed in micrometre-sized bubbles of fat, says team member Mark Borden at the University of Colorado, Boulder, who originally developed these microbubbles in the 1990s to improve ultrasound scans. Compared with pure oxygen gas, the tiny bubbles enormously increase the surface area and allow much more oxygen to diffuse through the colon into the bloodstream, he says.

For the pig tests, 12 pigs weighing between 40 and 50 kilograms were exposed to smoke. After two days, their blood oxygen saturation had dropped to 66 per cent on average. Colonic infusion of microbubbles in six pigs raised this to 81 per cent after 150 minutes. In the animals that weren’t treated, oxygen saturation fell to 53 per cent. The pigs were kept sedated throughout the procedure.

In addition, blood carbon dioxide levels fell in the treated pigs as it diffused into the microbubbles, while it kept rising in the animals that weren’t treated. This is important because high carbon dioxide has many adverse effects including impairing thinking, says Buesing.

“Your mental status declines to a point where you can no longer protect your airway,” she says.

Takanori Takebe at the Tokyo Medical and Dental University carried out a similar study in pigs earlier this year, but using a fluid called perfluorocarbon that can hold high levels of oxygen. He says the advantage of using oxygen microbubbles instead is that it should be easier to get regulatory approval than with perfluorocarbon, but that further studies will be needed to confirm how effective it is.

Takebe is continuing to develop the perfluorocarbon approach. His group has set up a company called EVA Therapeutics, which is planning to do a human trial in 2022.

The Respirogen team thinks oxygen microbubbles will prove to be more effective than perfluorocarbon. Perfluorocarbon – made famous by its portrayal as a breathing liquid in the film The Abyss – can hold a lot of oxygen, Borden says, but it doesn’t release it all, and might not remove carbon dioxide.

Reference: bioRxiv, DOI: 10.1101/2021.12.08.466665

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Solar storms may cause up to 5500 heart-related deaths in a given year



In an approximate 11-year cycle, the sun blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field, which may disrupt our body clock and ultimately affect our heart


17 June 2022

A solar storm

Jurik Peter/Shutterstock

Solar storms that disrupt Earth’s magnetic field may cause up to 5500 heart-related deaths in the US in a given year.

The sun goes through cycles of high and low activity that repeat approximately every 11 years. During periods of high activity, it blasts out charged particles and magnetised plasma that can distort Earth’s magnetic field.

These so-called solar storms can cause glitches in our power grids and bring down Earth-orbiting satellites. A handful of studies have also hinted that they increase the risk of …

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UK Covid infection rate rising, with more than a million cases in England | Coronavirus



Coronavirus infections are rising in the UK, figures have revealed, with experts noting the increase is probably down to the more transmissible BA.4 and BA.5 Omicron variants.

The figures from the Office for National Statistics (ONS), based on swabs collected from randomly selected households, reveal that in the week ending 11 June an estimated one in 50 people in the community in England are thought to have had Covid – around 1.13 million people.

The figure is even higher, at one in 45, in both Wales and Northern Ireland, while it was highest in Scotland where, in the week ending 10 June, one in 30 people are thought to have been infected.

While the figures remain below the peak levels of infection seen earlier this year, when around one in 13 people in England had Covid, the findings are a rise on the previous week where one in 70 people in England were thought to be infected. Furthermore, the data reveals increases in all regions of England, except the north-east, and across all age groups.

Experts say that a key factor in the increase is probably the rise of the Covid variants of concern BA.4 and BA.5.

“Infections have increased across all four UK nations, driven by rising numbers of people infected with the BA.4 and BA.5 Omicron variants,” said Kara Steel, senior statistician for the Covid-19 Infection Survey.

While Steel said it remained too early to say if this was the start of another wave, others have warned it may already have begun, with increased mixing and travelling among other factors fuelling a rise in cases.

Among concerns scientists have raised are that BA.4, BA.5 and another variant on the rise, BA.2.12.1, replicate more efficiently in human lung cells than BA.2.

Prof Azra Ghani, an epidemiologist at Imperial College London, said the latest figures were not surprising, and might rise further.

“This increase in infection prevalence is likely due to the growth of the BA.4 and BA.5 Omicron subvariants, which as we have seen elsewhere in Europe, appear to be able to escape immunity generated from previous Omicron subvariants,” she said.

“It is therefore possible that we will continue to see some growth in infection prevalence in the coming weeks and consequently an increase in hospitalisations, although these subvariants do not currently appear to result in any significantly changed severity profile. This does however serve as a reminder that the Covid-19 pandemic is not over.”

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NHS to offer women in England drug that cuts recurrence of breast cancer | Breast cancer



Thousands of women in England with breast cancer are to benefit from a new pill on the NHS which reduces the risk of the disease coming back.

The National Institute for Health and Care Excellence (Nice) has given the green light to abemaciclib, which cuts the chance of breast cancer returning after a patient has had surgery to remove a tumour.

Trials showed that patients who had the drug with hormone therapy had a more than 30% improved chance of their cancer not coming back after surgery, compared with hormone therapy alone.

“It’s fantastic thousands of women with this type of primary breast cancer will now have an additional treatment option available on the NHS to help further reduce the risk of the disease coming back,” said Delyth Morgan, the chief executive of charity Breast Cancer Now.

“The fear of breast cancer returning or spreading to other parts of their body and becoming incurable can cause considerable anxiety for so many women and their loved ones.

“New effective treatments such as abemaciclib, which can offer more women the chance to further reduce the risk of the disease recurring, are therefore extremely welcome and this is an important step change in the drug options available for this group of patients.”

The twice-a-day pill is suitable for women with hormone receptor-positive, HER2-negative, node-positive early breast cancer at high risk of recurrence who have had surgery. About 4,000 women will benefit initially, Nice said.

Helen Knight, the interim director of medicines evaluation at Nice, said the draft recommendation came less than a month after abemaciclib received its licence.

“The fact that we have been able to produce draft recommendations so quickly is testament to the success of our ambition to support patient access to clinically and cost effective treatments as early as possible,” said Knight. “Until now there have been no targeted treatments for people with this type of breast cancer.

“Abemaciclib with hormone therapy represents a significant improvement in how it is treated because being able to have a targeted treatment earlier after surgery will increase the chance of curing the disease and reduce the likelihood of developing incurable advanced disease.”

Abemaciclib works by targeting and inhibiting proteins in cancer cells which allow the cancer to divide and grow. It normally costs £2,950 for a packet of 56 150mg-tablets, but the manufacturer, Eli Lilly, has agreed an undisclosed discounted price for NHS England.

“Thanks in part to this latest deal struck by NHS England, NHS patients will be able to access another new targeted drug for a common and aggressive form of breast cancer,” said Prof Peter Johnson, the cancer director of NHS England.

“Abemaciclib, when used alongside a hormone therapy, offers a new, doubly targeted, treatment option, helping to increase the chances of beating the cancer for good, as well as meeting the NHS’s commitment to delivering improved cancer care under our long-term plan.”

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