Taking stock of animal experiments
Scientists tell us they're working hard to reduce the number of animals they use in laboratory experiments, replace them with alternatives wherever possible, and refine those experiments to minimise suffering.
This is the doctrine of the 3R's, and it forms the basis of the public's ongoing - qualified - support for medical research involving animals.
And yet the overall number of experiments continues to rise. The latest Home Office figures show the number of procedures carried out on laboratory animals rose 6% last year to 3.2 million.
Scientists explain this apparent contradiction by pointing to the enormous increase in the amount of research being done. Recent advances in genetics have allowed scientists to model human diseases in animals much more precisely - inserting the individual genes they suspect are responsible for conditions into rats and mice.
As a result researchers claim they're doing more, and better, work on wider variety of diseases. And if money's the crtieria, they might have a case. By 2010 the Medical Research Council's budget will top £682 million, while the National Institute for Health Research will spend a whopping £992 million.
But what about the other side of the coin? The commitment to reduce, replace and refine?
I talked to Professor Mike Emerson from Imperial College London, who's experimenting with imaging techniques in his work on Pulmonary Embolism. In the past he's used mice to study the progress of the disease, inducing clots to form in the lungs, and dissecting the animals to assess the performance of drugs designed to cure the condition. But by purchasing a simple probe that can be suspended over the mouse's chest he estimates he's reduced the number of animals he uses by 70-80 percent.
Along the corridor Professor Sian Harding is using human embryonic stem cells to replace animals in her work on heart disease. By stimulating a cluster of stem cells to develop into heart cells - cardiac myocytes - Professor Harding can study the progress of disease in a petri dish. And because these are living human tissues the results are even better than those provided by animal models - typically in rats.
But perhaps the most contentious issue surrounding the use of animals in medical experiments relates to their welfare. The conditions they're kept in and the level of pain and suffering they endure.
At Oxford, where the University's new Biomedical Sciences Building opened last month, a great deal of effort has gone into the design of the animal facilities. When the primates finally move in next year they will be housed in social groups, and in cages that feature climbing frames, tyres, ropes and perches.
The head of veterinary services at Oxford, Sarah Wolfensohn, argues that's both better for the animals and better for scientists since stressed or unhealthy subjects tend to produce less valuable results.