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Pig kidney works in human patient in 'potential miracle'******
In this September 25 image courtesy of NYU Langone Health, the surgical team examines the genetically engineered pig kidney for signs of rejection.
A US medical team has succeeded in temporarily attaching a pig's kidney to a person, a transplant breakthrough hailed as a "potential miracle" by the surgeon who led the procedure.
The surgery, carried out on September 25, involved a genetically modified donor animal and a brain-dead patient on a ventilator whose family had given permission for the two-day experiment, for the sake of advancing science.
"It did what it's supposed to do, which is remove waste and make urine," Robert Montgomery, director of the transplant institute at New York University Langone, told AFP.
Critically, the organ was able to reduce the level of the molecule creatinine, a key indicator of kidney health that was elevated in the patient prior to the transplant.
Montgomery carried out the surgery with several colleagues over the course of around two hours.
They joined the kidney to blood vessels on the top of one of the patient's legs, so that they could observe it and take biopsy samples.
The patient had wanted to be an organ donor and their family was initially disappointed when told their loved one's organs were not suitable, said Montgomery.
But "they felt a sense of relief that this was another opportunity for donation," he said. The patient was taken off the ventilator and passed away following the 54-hour test.
The genetically engineered pig kidney is prepared to allow for urine production.
'Important intermediate step'
Earlier research has shown that kidneys from pigs are viable in nonhuman primates for up to a year, but this was the first time it had been attempted with a human patient.
The donor pig belonged to a herd that had undergone a genetic editing procedure to knock out a gene that produces a particular sugar, which would otherwise have triggered a strong immune response and led to organ rejection.
The editing was performed by biotech firm Revivicor, a subsidiary of United Therapeutics.
"It is still a question what would happen three weeks from now, three months, three years," said Montgomery.
"The only way we're really going to be able to answer that is to move this into a living human trial. But I think this is a really important intermediate step, which tells us that at least initially, things are probably going to be okay."
He plans to submit the findings to a scientific journal in the next month, and says a clinical trial could take place in around a year or two.
The news was welcomed cautiously by outside experts, who nonetheless said they would like to see the peer-reviewed data before drawing firm conclusions.
"This news is a significant scientific achievement in the xenotransplantation field," Hynek Mergental, a surgeon at the University of Birmingham in Britain, said in a statement.
If confirmed, "it would be a major step forward in the organ transplant field that might solve the critical shortage of donor organs," he added.
A genetically engineered pig kidney is cleaned and prepared for transplant into a person.
The news comes amid a dire shortage of transplant organs.
According to official US data, there are nearly 107,000 Americans awaiting an organ – 90,000 of whom need a kidney. Seventeen Americans die each day while waiting for an organ.
To meet demand, doctors have long been interested in so-called xenotransplantation, or cross-species organ donation, with experiments tracing back to the 17th century.
Early research focused on harvesting organs from primates – for example, a baboon heart was transplanted into a newborn known as "Baby Fae" in 1984, but she survived only 20 days.
Today, pig heart valves are widely used in humans, and pig skin is grafted on human burn victims.
Pigs make the ideal donors because of their size, their rapid growth and large litters, and the fact they are already raised as a food source, said Montgomery.
World leaders gather in Glasgow for make******
Police officers patrol Glasgow Green near the Scottish Event Centre in Glasgow, Scotland, on Saturday, ahead of the United Nations COP26 climate summit.。
World leaders began descending on the Scottish city of Glasgow yesterday for the United Nations COP26 summit, billed as a make-or-break chance to save the planet from the most calamitous effects of climate change.。
Delayed by a year due to the COVID-19 pandemic, COP26 aims to keep alive a target of capping global warming at 1.5 degrees Celsius above pre-industrial levels – the limit scientists say would avoid its most deadly consequences.。
Meeting that goal, agreed in Paris to much fanfare in 2015, will require a surge in political momentum and diplomatic heavy-lifting to make up for the insufficient action and empty pledges that have characterized much of global climate politics.。
The conference needs to secure more ambitious pledges to further cut emissions, lock in billions in climate finance, and finish the rules to execute the Paris Agreement with the unanimous nod of the nearly 200 countries that signed it.。
"Let's be clear – there is a serious risk that Glasgow will not deliver," UN Secretary General Antonio Guterres told leaders of the Group of 20 rich nations last week. "Even if recent pledges were clear and credible – and there are serious questions about some of them – we are still careening towards climate catastrophe."
The existing pledges to cut emissions would see the planet's average temperature rise 2.7 degrees this century, which the UN says would supercharge the destruction that climate change is already causing by intensifying storms, exposing more people to deadly heat and floods, killing coral reefs and destroying natural habitats.。
The signals ahead of COP26 have been mixed. A new pledge last week from China, the world's biggest polluter, was labelled a missed opportunity that will cast a shadow over the two-week summit. Announcements from Russia and Saudi Arabia were also lackluster.。
The return of the United States, the world's biggest economy, to UN climate talks will be a boon to the conference, after a four-year absence under president Donald Trump.。
But like many world leaders, President Joe Biden will arrive at COP26 without firm legislation in place to deliver his own climate pledge as Congress argues over how to finance it and new uncertainty about whether US agencies can even regulate greenhouse gas emissions.。
Leaders of the G20 meeting in Rome this weekend will say they aim to cap global warming at 1.5 degrees, but will largely avoid firm commitments, according to a draft statement.。
The joint statement reflects tough negotiations, but details few concrete actions to limit carbon emissions.。
The G20, which includes Brazil, China, India, Germany and the US, accounts for about 80 percent of global greenhouse gas emissions, but hopes the Rome meeting might pave the way to success in Scotland have dimmed considerably.。
Adding to the challenging geopolitical backdrop, a global energy crunch has prompted China to turn to highly polluting coal to avert power scarcity, and left Europe seeking more gas, another fossil fuel.。
Ultimately, negotiations will boil down to questions of fairness and trust between rich countries whose greenhouse gas emissions caused climate change, and poor countries being asked to de-carbonize their economies with insufficient financial support.。
COVID-19 has exacerbated the divide between rich and poor. A lack of vaccines and travel curbs mean some representatives from the poorest countries cannot attend.。
COVID-19 will make this UN climate conference different from any other, as 25,000 delegates from governments, companies, civil society, indigenous peoples, and the media will fill the event venue.。
World leaders will kick start COP26 today with two days of speeches that could include some new emissions-cutting pledges, before technical negotiators lock horns over the Paris accord rules. Any deal is likely to be struck hours or even days after the event's November 12 finish date.。