动物实验 z-bo 2020-09-14 307

　　Don’t use the donated lungs for transplantation due to severe damage. However, after the researchers used live pigs to supply blood to these lungs, they regained their vitality. Researchers say this technology will triple the number of transplantable lungs. Related papers were published in "Natural Medicine".

　　The lungs began to degenerate after death. If the deceased chooses to donate his lungs, the organ must be transplanted to the recipient as soon as possible. James Fields of the University of Manchester said: "The lung is one of the most fragile and difficult organs to preserve."

　　According to "New Scientist", most donated lungs can stay outside the body for several hours. However, most cells are still severely degraded and cannot be safely used for transplantation. According to the American Lung Association, in the United States, only about 28% of donated lungs meet the criteria for transplantation. Current strategies to increase available lung sources include the use of extracorporeal lung perfusion (EVLP) to support lung function before transplantation. This technology can provide oxygen and nutrients without interruption, but Gordana Vunjak-Novakovic of Columbia University in New York still fails for many people.

　　Vunjak-Novakovic and his colleagues wanted to know whether the performance of the source would be improved if the human lungs are connected to living organisms and other working organs that can provide nutrients and remove harmful substances. I would like to know. To find out, the research team obtained lungs from six donors that did not meet the transplant criteria, including one and two lungs. Five hours after using the EVLP device, one of the lungs broke down, and the research team had been away from the body for 24 hours before receiving the device.

　　The research team connected these lungs to the circulatory system of anesthetized pigs for 24 hours. Researchers use test tubes to introduce pig blood into human lungs. At the same time, a ventilator is used to pump air into the lungs and apply immunosuppressants to these pigs to prevent rejection by the immune system.

　　According to previous research by Vunjak-Novakovic, this process does not seem to have a lasting effect on pigs. Previous experiments have shown that these pigs can walk around, play with toys and eat when connected to equipment used to support the lungs of other pigs. Before receiving "treatment", all lungs had many white areas, indicating that the tissue was dead and unable to inject enough oxygen into the blood. However, after 24 hours of connection, these lungs seem to have changed. The Vunjak-Novakovic team conducted a series of tests and found that the lung cells, tissue structure and oxygen supply capacity have been significantly improved, and even the lungs that have been cultured in vitro for nearly two days seem to be recovering.

　　"Not 100% normal, but close enough," Vunjak-Novakovic said. In theory, these lungs look healthy enough for transplantation, but the potential clinical application of this method should be evaluated, that is, whether the residual pig cells and factors in the lungs will cause the transplant recipient. She said more research is needed, such as evaluation. Immune response or disease transmission. Based on this, Vunjak-Novakovic plans to use medical pigs that will not hide harmful pathogens that can be transmitted to humans. However, this does not necessarily mean that the pig cells in the lungs are completely depleted. Fields warned that the current study found that the lungs of pigs contain white blood cells that can stimulate the recipient's immune response.