For patients with heart failure, end-stage is heart transplantation is often the only Chance for a cure. However, there are far fewer donor organs than needed. Therefore, physicians research for many years to solve the Problem through the Transplantation of pig hearts. Pigs are useful as donors, especially because your metabolism to the the people similar to.
The method is currently tested, especially in baboons, before you can come in people. The Problem is that The animals have survived so far to a maximum of 57 days, if your heart has been replaced.
Now a researcher reports Reichart’s team of the Munich heart surgeon Bruno and veterinarian Eckhard Wolf in the scientific magazine “Nature” progress. They had changed with the new technology of genetically – specifically, it was a question of possible rejection reactions after Transplantation to suppress – pig hearts in baboons transplanted. There they replaced the original heart of the animals for a longer period of time.
Reduced blood pressure body conserve
Of five animals were terminated according to the report, the scientists two even after 90 days in good health, as your attempt. Two animals lived even 195 and 182 days, so a good half a year before they were killed. Heart and liver function had been normal, rejection reactions did not exist. An animal died, however, after 51 days of a thrombosis.
Reichart, 1983 succeeded the first heart-lung transplantation in Germany, has been working for a long time with the subject and was for many years the Board of management of the special research group for Xenotransplantation of the German research Foundation (DFG). For the current Experiments, the Team had chosen a new approach in Transplantation: to cool, Instead of, as usual, the heart with ice, it was connected to a circuit with a 8 degree Celsius warm blood substitute liquid, so that it was before and during the Operation, oxygen is supplied to the.
This was, possibly, also in the case of conventional transplants, in humans, a way to improve the success, said Reichart.
artificial heart as a last resort, DPA artificial heart: life-saver in the chest
The team of scientists to Reichart and Wolf reduced in the experiments, the blood pressure of the baboons in the Operation – on the pigs of the usual values. This served to protect the transplanted heart.
The researchers had to solve another Problem: baboons are smaller than pigs. This circumstance could lead to Betgaranti the surgery, the pig’s heart grows too strong, and thus, in primates, fatal liver damage may occur. Therefore, the researchers gave them a drug to the growth curb. That would be when people are superfluous, because his heart is in the size corresponds approximately to the pig’s heart.
The overall result is a milestone on the way to a possible Transplantation of pig hearts in people, the scientists. As a General rule, the time is fulfilled, with the Survival of three months by the International transplantation society established a requirement for clinical Trials.
researchers want to Reichart in addition to the heart and kidney transplant
About three years would take more preparations before the first clinical studies in selected patients could be possible, “if everything goes well”. Only further animal testing would have to follow, so the researchers. According to the guidelines for clinical studies, six out of ten animals should be of at least the Three-month period. This can be achieved in half a year, said Reichart. “We hope that we are in the spring done with it.”
in Parallel, it is now about to test new immunosuppressants. “We need a humanized anti-body, we need to use in the next two years,” said Reichart. “We hope that we get approval to make pilot studies.” Not only the pig’s heart, but also kidneys to be transplanted. In Parallel, it will take more years, until the animal donor organs used than the standard method, and animals were able to be produced especially for the purpose.
animal-donor organs would have many benefits, said Reichart. The entire Microbiology of the donor organ, in contrast to donor hearts of dead people. This will lower the risk of infections. The receiver could be prepared in peace. “This is the Elegant of Xenotransplantation: In contrast to human transplant, everything is known in advance.”
Independent experts evaluate the study as an important step on the way to a transplant in humans. Four of the five baboons seemed to tolerate the transplant well without developing serious infections due to immunosuppression, said the Berlin transplant expert, Christoph Knosalla, in a “Nature”comment. Therefore, this technique could work in humans, if the Xenotransplantation – advanced exchange across Species boundaries – far enough to start the first clinical Trials.
The Aachen-based physician, Rene Tolba, called the results “clinically highly relevant”. “The first clinical indication for such Xenotransplantation could be the so-called “Bridge to transplant”. A critical heart patient waiting for a donor organ would be offered a transplant of a pig heart as a Bridge.” For this time, however, even now, mechanical pumps can be used.
Sabine Dobel, dpa/chs
