Dr. Gary Small
University of California, Los Angeles

An estimated five million Americans suffer from Alzheimer's disease, and millions more have mild cognitive impairments that put them at risk for future memory decline. Dr. Small's revolutionary work with PET scans revealing Alzheimer's lesions in the brain has led to a better understanding of the development of the disease. The scans reveal brain plaques and tangles - the physical evidence of Alzheimer's disease - in living humans. This technology can identify people most likely to benefit from prevention treatments even though they may not develop Alzheimer's disease for years. Brain scanning technology could also help bring new anti-Alzheimer's drugs to market sooner and less expensively, and enable quick adjustment of a drug dosage or a switch to another medication when indicated.

Dr. Small describs brain-boosting techniques, such as mental exercise, stress reduction, healthy diet, and physical exercise, for improving memory performance and lowering risk for future cognitive decline.

Dr. Rudolf Jaenisch
Whitehead Institute for Biomedical Research

Building on the current science of embryonic stem cell research, Dr. Jaenisch invites us to look at the next chapter in the progression of this science. Dr. Jaenisch is a leader in the field of therapeutic cloning, also called somatic cell nuclear transfer (SCNT), in which the genetic information from one cell is transplanted into an unfertilized egg from which DNA has been removed. When placed in a Petri dish, this egg develops into a blastocyst - one of the first stages of embryo development - from which embryonic or pluripotent stem cells can be taken.

Embryonic stem (ES) cells are derived from early-stage embryos and can grow indefinitely in culture. Existing human ES cells have been generated from "excess" IVF embryos that were donated for research. ES cells are pluripotent, which means they have the potential to become all cell types of the body. This ability provides these cells with an enormous potential for research aimed at understanding human development and treating human diseases.

One of the great promises of ES cells is their potential for use in developing new therapies for debilitating diseases such as cancer, diabetes, and Parkinson's. To realize this potential, much research is needed to learn how to differentiate the embryonic cells into cells that could be used for transplantation.

Using a form of SCNT called "altered nuclear transfer," Dr. Jaenisch created an embryo-like entity that was genetically incapable of implanting in a uterus. Although this entity was not a viable embryo, it did yield perfectly healthy embryonic stem cells. Dr. Jaenisch's therapeutic cloning research has used mice exclusively. One day this research may lead to therapies for currently untreatable human diseases.

Dr. David Fisher
Dana-Farber Cancer Institute

Skin cancer is a common and potentially deadly human malignancy whose incidence is linked to sun exposure. It is, in principle, among the most preventable of human cancers. However, certain features of skin cells complicate our understanding of how best to prevent the disease and how to cure it.

Dr. Fisher’s research shows us clues to skin cancer treatment as well as prevention. These insights have been gained through the study of natural events affecting skin: the process of hair graying and the sun-tanning response. Through analyses of these normal events in everyday life, new opportunities have been identified for both prevention and treatment of skin cancers.