The science of healing is developing so quickly that it has become almost a cliché to describe a particular operation as a "breakthrough". Yet there is no doubt that the first successful transplant of a human windpipe, constructed partly from stem cells, is an astonishing milestone – one that could indeed mark the start of a new era in medicine.
At long last, the glint in a researcher's eye has been turned into a significant advance in the clinic. Forget all the fuss about embryos and angst about playing God: this is unadulterated good news. We have proved that scientists can now fashion organs using a patient's own cells, eliminating the problems with rejection that have always plagued transplants. Today it is a trachea – tomorrow it could be a colon, even a heart.
The venture was a textbook example of international collaboration, drawing on the talents of teams in Spain, Italy and Britain. To recap; the operation, on 30-year-old tuberculosis patient Claudia Castillo, took place in Barcelona, where doctors also had collected a three-inch segment of trachea from a 51-year-old donor who had died of a cerebral hemorrhage. They used a technique developed in Padua to strip the windpipe of its donor's original cells, a procedure that took six weeks, to create a "scaffold". At the same time, a team in Bristol used a "bioreactor" dreamt up in Milan to grow stem cells removed from Castillo's bone marrow. These cells were "seeded" into the donated windpipe, disguising the 'foreign' tissue that remained so Castillo's body would accept it as her own.
There is a desperate need for this kind of advance. In Britain, about 8,000 people are on the waiting list for an organ transplant. Around 3,200 such operations are carried out every year – but roughly 1,000 of those on the list will die before they get a transplant. And that is only the start of the problem: after a transplant, there is a high risk of rejection as the recipient's immune system reacts against the donor organ. Immunosuppressant drugs are used to limit this but their side-effects include high blood pressure, diabetes and kidney failure, vulnerability to infections, osteoporosis, and cancer. In all, the drugs cut life expectancy by an average of 10 years.
As we now know, Claudio Castillo experienced no such problems: two months after the surgery, which took place in June, her lungs were functioning just as well as those of most young women her age. The result, says Martin Birchall, professor of surgery at Bristol University, leaves us "on the verge of a new age in surgical care". But what will that new age look like? Even before this week's announcement, there has been a steady trickle of advances that reveal the potential of this medical revolution. There are attempts to free insulin-dependent diabetics from reliance on needles, by using injections of their own stem cells. Trials are under way in Britain on more than 90 patients to test the use of stem cells to help repair damaged hearts. Prof John Martin of University College London who is leading the project, says things are "going well".- telegraph
What would you do differently if you knew you never had to die of old age?
No comments:
Post a Comment