Feb. 6, 2001 -- Mirror, mirror on the wall, what will be the greatest medical advance of all? Will it be an injection-free way to treat diabetes? A cure for genetic lung diseases like emphysema? An early diagnostic test for Alzheimer's disease or osteoarthritis?
The answer depends largely on whom you ask. One thing is clear, however: The next 25 years will mark an exciting time for medical research, and no specialty or disease will be untouched by changes afoot in research labs across the country. This is the message of experts speaking at a media briefing on medical research in the 21st century, sponsored by TheJournal of the American Medical Association and the Albert and Mary Lasker Foundation.
Advances in imaging technologies and biotechnology and the mapping of the human genome have already given birth to new medical disciplines and new therapies for existing diseases. The Human Genome Project is an international research program designed to construct detailed genetic and physical maps of the human genome. In theory, this will help scientists develop new therapies to correct the genetic abnormalities that can cause disease.
Though significant challenges remain, including understanding disorders with both genetic and environmental causes, "the possibilities for progress in medical science and the opportunities for medical research have never been greater," says David G. Nathan, MD, President Emeritus of Dana-Farber Cancer Institute and the Robert A. Stranahan Distinguished Professor of Pediatrics at Harvard Medical School, both in Boston.
The field of neurology has been completely transformed by molecular genetics, which lets researchers understand the genes causing neurological diseases, says Eric R. Kandel, MD, the winner of last year's Nobel Prize in Medicine.
Psychiatry has been intrinsically changed by new brain imaging techniques that enable researchers to see how areas of the brain are affected by psychiatric illnesses, explains Kandel, who is University Professor at Columbia University College of Physicians and Surgeons in New York City and a senior investigator at the Howard Hughes Medical Institute.
As scientists continue identifying the genes responsible for neurological and psychiatric illnesses, they will get closer to developing new therapies that can turn a gene off like a light switch and prevent or reverse certain diseases, Kandel says. Specific genes encode proteins that, in turn, may cause disease.
And this is especially important now because "as the population ages, diseases of the nervous system are likely to become even more abundant than they are now," he says. Diseases of the nervous system include Parkinson's disease, Alzheimer's disease, and Huntington's disease.
As it stands, nearly 500,000 Americans suffer a stroke each year. Alzheimer's disease affects more than 4 million people, and about 17 million people suffer from serious depression. Millions of Americans are afflicted with other psychiatric or neurological disorders, including drug and alcohol abuse, schizophrenia, brain tumors, and epilepsy.
The 21st century will usher in an intimate partnership between psychiatry and neurology, and this union will result in better treatments for autism, mental retardation, Alzheimer's disease, Parkinson disease, drug and alcohol abuse, and a laundry list of other brain diseases, Kandel predicts.
"The futures of psychiatry and neurology are bound together because both are concerned with disorders of the brain," he says. "We will re-think the training of neurologists and psychiatrists and bring them closer together [through a] common training program that devotes itself to the fact that these are related disorders."
Mapping of the humane genome and the advent of molecular medicine have also given rise to a new field called "biomedical engineering," says Linda Griffith, PhD, associate professor of chemical engineering and bioengineering at the Massachusetts Institute of Technology in Cambridge.
Biomedical engineering is the application of engineering principles to problems in clinical medicine and surgery, she explains.
"Biomedical engineering will have a huge impact on medicine, but it will also touch our lives with other technologies that may be developed, including agriculture and pharmaceutical [technologies]," she tells WebMD.
"We have a whole new science, so now we can have a whole new engineering," she says. The end result, Griffith predicts, will be earlier diagnosis and improved treatment for a whole host of diseases.
For example, researchers are working toward developing "lab on a chip" technology so they can diagnose conditions earlier using markers and blood samples.
"This technology can put 1,000 different components of blood on a chip and use the information to predict disease risk," she says. "Companies are already trying to do this."
For example, researchers may one day be able to detect Alzheimer's disease in early adulthood by testing for specific markers.
"It's a slow inflammatory process. You don't realize you have a significant problem until you have pain all the time, and by the time that happens, your joint needs to be replaced," Griffith tells WebMD. "If you could detect it earlier, there are more options on how to treat it."
Instead of joint replacement surgery, which does not provide relief for very long, doctors may be able to transplant cells that can help reverse damage, she explains.
With diabetes, researchers may be able to transplant islet cells instead of relying on insulin injections to keep blood sugar, or glucose, levels in check, she says. Islet cells are tiny insulin factories that produce insulin in response to blood glucose. These islets sense the level of glucose in the bloodstream and produce insulin in precise proportion to that level. Therefore, after a meal, blood sugar levels will rise significantly, and the islets will release a large amount of insulin.
Ronald G. Crystal, MD, a senior faculty member of the Weill Medical College of Cornell University in New York City and the chief of pulmonary and critical care medicine at New York Hospital, says that there have been major advances in treating lung disease in the past 25 years.
And "in the next 25 years, we will understand the lung as an integrated organ that has to have the defenses to protect us against a hostile environment," he says. "There is no question of the impact that the knowledge of the genome will bring to the understanding of the lung and the susceptibility to asthma and other pulmonary disorders."
Certain genetic diseases of the lung, including emphysema and cystic fibrosis, will be cured by gene therapy in the next 25 years, predicts Crystal.
In fact, "if we knew that [former first lady] Eleanor Roosevelt had a genetic susceptibility to tuberculosis, we could have protected her from it, and if we knew that [actors] Humphrey Bogart and John Wayne had susceptibility to lung cancer, we could have convinced them not to smoke," he says.
And scientists may improve success rates of lung transplantation by learning how to grow new lung cells from existing lungs, he says. This will eliminate the problems of having too few organs available for donation and of the transplant recipients' bodies rejecting the foreign organs they receive.
Currently, researchers are working on ideal ways to deliver such novel therapies as well as grappling with the ethical issues that come with the new technology.
Thanks to the mapping of the human genome, "genetic prediction of individuals' risks of disease and responsiveness to drugs will reach the medical mainstream in the next decade or so," write Francis S. Collins, MD, PhD, and Victor A. McKusick, MD, in TheJournal of the American Medical Association. Collins is director of the National Human Genome Research Institute at the National Institutes of Health in Bethesda, Md., and McKusick, widely regarded as the father of modern clinical genetics, is University Professor at Johns Hopkins University School of Medicine in Baltimore.
"The development of designer drugs, based on the genomic approach to targeting molecular pathways that are disrupted in disease, will follow soon after," they write.
They point out that other obstacles will also need to be overcome, including fear of discrimination based on genetics as well as other ethical, legal, and social issues.