Organ transplants between species

The inter-species organ transplant project is nearing its feasibility as the world's first pig herd has been genetically modified to promise new therapies for many diseases. Scientists have had initial success in transplanting their organs in baboons, and may in the next few years begin experiments on humans .

David Ayares with a million-dollar pig (big picture) and hereditary pig herd (Photo: Laborer)

At Revivicor Farm on Blue Ridge Hill, the flock of pig-eared ears - a genetic marker - is growing rapidly."They are millions of dollars of pigs, " said David Ayares, the rancher and director of Revivicor Biotechnology Company, saying: " Their DNA has been calibrated with specialized genes. There are alpha-1-galactose sugars, which make the human body always reject their tissues and organs . '. He explains: 'Our bodies carry special antibodies that will quickly recognize this type of sugar and will react to elimination in just a few minutes. Therefore, the gene has been corrected, and there will be modifications of genes that function to create another pathway in the next herd . On a near day, their organs will be safe for transplanting. transplant into human body . '.

Positive signals

Early realizing the possibility of cross-species transplants to be a future biological breakthrough, through Revivicor joint venture partners, Pittburgh University Medical Center (UPMC) has boldly invested in each field. This controversy.'Organ transplants between species are a potential problem that many people can do' - said Dr. Thomas E. Starzi, veteran transplant specialist at UPMC. He is one of the pioneers in finding interdisciplinary alternatives to improve the serious shortage of organ transplant needs. 'UPMC and Revivicor are having initial successes, promising future plans .' - he added.

In the future, the organs of pigs will be implanted safely for humans (Photo: Laborer) In experiments at UPMC, genetically modified pig hearts have progressed well in about 3 months after transplanting in monkeys. Dog heads, and some have longer lifespans . This success is expected to grow longer, possibly up to 6 months or more after scientists have made other corrections. in pig genome.

Market 6 billion dollars

Since 2004, monkeys' kidney transplant experiments in UPMC are headed by Dr. Massimo Trucco. Researchers here are planning a pig heart transplant for patients with severe heart failure to replace mechanical pumps. According to Revivicor estimates, the market for future transplanted pig organs is estimated to be worth at least $ 6 billion. UPMC, Revivicor and the US Food and Drug Administration (FDA) plan to have clinical trials on humans within the next few years . The first goal is to use specialized production cells. insulin of pig kidneys to improve insulin levels in type 1 diabetics; and there were about 40 patients at Mexican Children's Hospital who received pig kidney cell transplants in the last 5 years, some of which significantly reduced the need for insulin supplementation .

According to a survey by the US Department of Health, there are currently more than 90,000 people waiting for organ transplantation across the country, and it is estimated that about 6,300 people died in 2005 while waiting for the transplant agency. Experts estimate that only about half of the donor source is approved by the employer, especially kidneys and hearts .

From monkeys to pigs

UPMC's concern about organ transplants among species is not new. In 1992, under the direction of GS-TS Starzi and Dr John J. Fung, surgeons at Pittburgh University grafted baboons into a 35-year-old male patient. He lived 70 days. Another case of liver transplantation from baboons to humans was also done in 1993, but the recipient died after 26 days due to infection .

Baby Fae girl's chest is placed in the heart of a baboon in 1984 (Photo: BBC) The organ transplant effort between different species begins with the world famous case, Baby Baby Fae . On October 26, 1984, doctors at Loma Linda University Medical Center, California, placed this girl's heart in the heart of a baboon. After a few healthy days with a good heart, her body began to increase the reaction to eliminate foreign objects, and she died after 20 days of heart transplant . 'There is a lot of promise about implantability future interdisciplinary agencies, only thing . this field cannot bring about a one-way success as our wishes' - Dr Christopher McGregor, a transplant specialist at Mayo Hospital, to speak.

With this ambition, at least 8 companies are pursuing research projects on organ transplants among species. And the pig organ has emerged as a promising path, because the size of their organs is very suitable for the human body, pigs are less controversial than monkeys, because they are often slaughtered. .

Anticoagulant genes

In an article in the Transplantation issue in November of last year, Cooper said six of the eight baboons receiving genetic corrected pig heart transplants lived nearly six months. However, they must suffer from the immune system's elimination reaction, mainly blood clots in small blood vessels. These blood clots are getting bigger and eventually killing experimental animals.

Currently, scientists at Pittburgh University have inserted an anticoagulant gene from humans to help pigs solve this problem. Researchers at Imperial College London have also succeeded in experiments on this ability in rodents."This anticoagulant gene helps prevent all common elimination reactions when organ transplantation is performed," Cooper said. Revivicor is currently working at the FDA's request to ensure there are no 100 specific viruses and bacteria in their swine herd, which can be dangerous for recipients .

New Horizons

UPMC researchers have seen a promising horizon with Highmark Inc. health insurance. $ 1.5 million in sponsorship as part of a new funding plan, while Fujisawa Investments for Entrepreneurship LP also invested $ 500,000 . And, last September, Revivicor was signed with Zimmer Holdings Inc., an Indiana surgical company to use pig cells for transplantation, to repair damaged cartilage, ligaments, bones and tissue. These transplants are extracted from pig skin, some to treat hernias and dislocated joint muscles in accidents. According to experts, when these cells die, their bodies are still used to stimulate cell growth in and around the joints .

Prospects than stem cells

According to Dr. David Kc.Cooper at the University of Pittsburgh - an organ transplant specialist, who taught at Harvard University, organ transplantation between species is much more feasible than stem cells, and other scientists also give It is possible to replace any type of human body cell from this 'raw material' source. 'Creating a heart, a kidney or a liver . from stem cells can now carry the concept of science fiction - he said. That can only be realized in 50 or 100 years. However, with pigs, at least we have organs available, especially when they show good performance in animal experiments. '

Dr Cooper also said that genetic pig hearts could provide temporary relief for patients with congestive heart failure, a common disease in people. A heart cannot pump enough blood to organs in the body.Some people with this disease are currently treated with a mechanical solution, which is an artificial pumping device inserted into the abdomen.According to Cooper, in some special cases, the use of pig heart can help patients survive longer than artificial pumping equipment.

Gia Dao