For the first time, researchers have created lungs in the lab and successfully transplanted them into pigs.
These bioengineered lungs, described online in Science Translational Medicine, developed healthy blood vessels that allowed pigs to live for several weeks after surgery without medical complications. That’s a significant improvement from previous efforts: Lab-grown lungs implanted in rodents failed within hours, before the lungs could develop the complex blood vessel network necessary for long-term survival.
If the new procedure can be adapted for humans, with bioengineered lungs grown from a patient’s own cells, that could reduce the risk of organ rejection and slash wait times for organ transplants. In the United States, where about 1,500 people currently are on a waiting list for a lung transplant, the average wait is a few months.
“This study really brings the whole research field to the next level,” says Xi “Charlie” Ren, a biomedical engineer at Carnegie Mellon University in Pittsburgh not involved in the work.
For the study, immunologist Joan Nichols at the University of Texas Medical Branch at Galveston and colleagues built lungs for four pigs by first using a sugar and detergent mixture to strip the cells from lungs of donor pigs. That left sterilized, pearly white, lung-shaped scaffolds made of the intercellular proteins. (In humans, researchers envision using donated organs or 3-D printing made-to-fit lung scaffolding.) The researchers then repopulated each scaffold with blood vessel and lung tissue cells from the pig destined to receive that organ.
Each engineered lung grew for 30 days inside a bioreactor tank, pumped full of nutrient cocktails that helped cells stick to the scaffold and multiply in the right spots. The researchers then replaced the left lung of each pig with the bioengineered version.
After surgery, Nichols’ team allowed one pig to survive for 10 hours, another for two weeks, a third for a month and the fourth for two months. At each pig’s demise, the researchers did an autopsy on the animal to see how the new lungs integrated into the pigs’ bodies over time. None of the animals was given immunosuppressant drugs, and none of the transplants was rejected. Inside a pig’s body, the bioengineered lung’s blood vessels plugged into to the animal’s natural circulatory system, supplying the organ with oxygen and nutrients to survive.
The animals’ post-op recovery was “pretty amazing,” Ren says. The pig that lived two months after surgery didn’t experience any breathing problems, and its lung transplant was colonized by bacteria that inhabit normal pig lungs — signs that the tissue was developing normally and integrating well into the body.
But these lab-grown lungs aren’t quite ready for prime time, says Laura Niklason, a biomedical engineer at Yale University not involved in the work. While the bioengineered lungs linked up with the pigs’ circulatory systems, the organs weren’t connected with the animals’ pulmonary arteries — which carry low-oxygen blood for the lungs to replenish with oxygen from air breathed in. That left the pigs to rely on their natural right lungs for air after surgery.
“The next step is hooking the organ up to the pulmonary artery” to ensure that bioengineered lungs get oxygen into the blood as well as normal lungs, Niklason says.
In other research, a new study has found that people’s IQ scores have started to deteriorate after climbing steadily since Wold War Two.
The fall, which equates to about seven points per generation, is believed to have begun with those born in 1975, according to the first authoritative study of the phenomenon.
The drop in scores marks the end of a trend – known as the Flynn effect – which has seen average IQs rise for the past 60 to 70 years by roughly three points a decade.
Scientists have described the results as ‘impressive’ but ‘pretty worrying’, according to the Times.
The decline is do with a difference in technique in the way languages and maths are taught in schools, scientists have suggested.
However, it could also be down to people spending more time on technological devices instead of reading books.
Stuart Ritchie, a psychologist at the University of Edinburgh who did not take part in the research, told the newspaper: ‘This is the most convincing evidence yet of a reversal of the Flynn Effect.
‘If you assume their model is correct, the results are impressive, and pretty worrying.’
However IQ scores might have fallen since the turn of the millennium, according to previous studies.
Two British studies suggested that the fall was between 2.5 and 4.3 points every ten years.
But due to limited research, their results were not widely accepted.
In the latest study Ole Rogeburg and Bernt Bratsberg, of the Ragnar Frisch Centre for Economic Research in Oslo, found that Norwegian men’s IQs are lower than the scores of their fathers when they were the same age.
The pair analysed the scores from a standard IQ test of over 730,000 men – who reported for national service between 1970 and 2009.
The research has been published in the Proceedings of the National Academy of Sciences of the United States of America Journal (PNAS).
The findings come after scientists revealed in December 2017 that regularly eating fish improves children’s intelligence as well as helping them to sleep better.
They found that nine to 11-year-olds who eat it at least once a week scored almost 5 points higher in IQ tests to those who ‘seldom’ do.
In this study by US researchers, more than 500 children were asked about how often they had consumed fish in the past month – with options ranging from ‘never’ to ‘at least once per week’.
They then took part in an IQ test which also considered such as verbal and written communication skills.
After taking into consideration factors such as their parental education, occupation and marital status, it found children who eat fish least once a week score 4.8 points higher than those who never do.
Even those whose meals sometimes include fish scored 3.3 points higher.
James E Windsor, Overpasses News Desk
August 3rd, 2018