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After three days of discussions about stem cell machinery, the organizers concluded the Keystone meeting on stem cell biology today by treating participants to data showing what these cells can already do in humans. These efforts appear not quite as differentiated as stem cells themselves, but are hopefully on their way to becoming so.

Tonight, Michele De Luca from the Veneto Eye Bank Foundation and the University of Modena in Italy presented a series of stomach-churning videos and images illustrating how he and his colleagues used autologous stem cells to correct both blindness and a rare, blistering skin disease. In a study involving nearly 200 people blinded after burns depleted their stores of limbal stem cells, stem cell transplants corrected the vision of the majority of patients, even several years after the operation. Another man with epidermolysis bullosa (EB), a disease in which the slightest trauma causes major damage to the skin, received transplants of his own genetically corrected epidermal stem cells, and experienced major improvements in the areas that received the transplant. Four months after the procedure, "there is a complete regeneration of the epidermis," De Luca told the audience. (Indeed, the pictures showed remarkable differences between the swaths of treated and untreated skin.) De Luca said he plans to continue the experiment, transplanting the rest of the patient?s skin "step by step."

Following De Luca?s presentation, Ronald McKay from the National Institutes of Health estimated that as early as within the next several months, researchers might obtain dopamine neurons from human embryonic stem cells -- a potentially major advance for people diagnosed with Parkinson?s disease. However, he and his co-presenter, Olle Lindvall from the Wallenberg Neuroscience Center in Lund, Sweden, cautioned against immediate enthusiasm. Lindvall noted that one first has to demonstrate that these new cells work, and work better than existing therapies, to justify testing them in humans. McKay agreed, noting that, despite the immediate need, it?s vital to first understand the developmental biology of the system before proceeding to the clinic.

We even saw promising data from studies of man?s best friend, the dog -- in this case, golden retrievers with a form of muscular dystrophy. Curiously, the experiments, conducted by Giulio Cossu from the University La Sapienza in Italy, and his colleagues, showed that transplants of wild type donor stem cells appeared to work better than autologous, corrected stem cell transplants -- a finding deemed "amazing" by an audience member during the Question & Answer period following the presentation.