Because WHO EDX is specifically set up to discuss xenotransplantation, I feel it fosters a kind of tunnel vision that unintentionally presents a picture of xenotransplants or nothing. I would like to focus (again) on investing more of our resources in learning how to prevent diseases like diabetes which cause the demand for human donor
organs to outstrip the supply. (N.B. This is in no way intended to blame or overlook the needs of people already needing organ replacements because the treatment they received has not produced satisfactory results, but to point out that others might be spared in the future, leaving more organs available for their needs, if a higher proportion of our research were to be directed toward looking for causes.) We need to find out why the incidence of diabetes, asthma and other diseases is increasing.

In his response to the Paradis report in SCIENCE, 1999:285,
1236-1241, Edward Moore, M.D., Consultant in Public Health, Scotland, names diabetes as "the leading cause of premature organ failure" and cites an estimate (Mandrup-Poulson, T: Diabetes, BMJ, 1998 316 1221-5) that the number of cases in the UK will double from 1.5 to 3 million in the next 15 years.  I think we need to look into why this seems to be the case.

Studies in Sweden, Finland, Canada and the US indicate that cows'
milk given to IDDM-susceptible newborns may be a factor. There may well be other dietary and environmental factors that afford the disease the toehold it needs to dominate someone's life. The effect of increased use of vaccines at an ever younger age needs to be investigated.

I don't think anyone has responded to my earlier suggestion that human islet cells could be grown using existing cell culture techniques, which would be a lot cleaner and less expensive than genetically manipulating pigs to more resemble humans, and, as has also been proposed, genetically manipulating humans to more resemble pigs.  Culturing cells could afford an endless supply of islet cells with less chance for contamination.

Since making that suggestion, I have learned that Alberto Hayek, Professor of Pediatrics and Director of Whittier Islet Research Laboratory at UC-San Diego Medical School, and colleagues have succeeded in culturing insulin-producing islet cells from both adult islet cells and fetal stem cells. Using HTP9 as a matrix, nicotinamide as a stimulator and trehalose to assist cells to survive freezing, this
lab has succeeded in expanding fetal cells by a factor of 200 and adult islet cells by a factor of 1,000. I cite this only as an indication that we don't want to be so narrowly focused on pig cells that we lose sight of other solutions to the cell and organ supply problem we are trying to solve.

The current issue, September 1999, of Scientific American has an article on "neo-organs" describing how the body can be induced to make its own repairs by inserting something like a growth factor molecule in a wound or failing organ. It also mentions the possibility of inserting a polymerase scaffold with starter cells to repair an organ . So far we have only fabricated skin, cartilage, bone, ligament and tendon tissues, but this technique holds future promise.

To answer Al Gordon's request to "show me what evidence exists for the promise held by closed-loop insulin pumps", I refer to "Diabetes" in Johns Hopkins Internet lay publication Intelihealth, last updated July 15, 1999 in which it is stated that "Implantable pumps have been used by hundreds of people with good results". They are still considered experimental, however. There have been problems with clogged catheters as well as skin infections at the site
of the implant. Compared to all the problems with raising pigs in sterile conditions, inserting organs that have evolved to serve a different species with different characteristics from humans, and overcoming rejection problems, the problems with implanted insulin pumps appear, superficially at least, to be easier to solve. The Intelihealth report continues: "This research is leading, ideally, to an implantable artificial pancreas" once researchers have "figured out how to make an automated internal glucose sensor part of the package." We all know, however, that such optimistic claims can take years to materialize and may wind up being set aside if funding dries up or a more promising technology comes along.

Still, it is part of the total range of possibilities that need to be
considered alongside xenotransplants.

Bina Robinson
CIVITAS: Citizens for Planetary Health
civitas@linkny.com


          xenotransplant index    Autumn 1999 issue of The Civil Abolitionist