Secrets unlocked, many new discoveries waiting: today’s medicine will look primitive

Press, 26 December 1985, Page 13

Secrets unlocked, many new discoveries waiting: today’s medicine will look primitive

By

BARBARA MOFFETT,

National

Geographic News Service

well-programmed computers. Meanwhile, health specialists say, more physicians will cease being repairmen. By 2000, Americans may spend as much time and money on prevention of illness as on treatment, and look to changes in lifestyle, not technology, for their well-being. “We have it within ourselves to control our cardiac destiny,” says Dr Robert I. Levy of Colombia University. He believes that education about smoking and diet, especially cholesterol, will help bring heart disease down as a No. one cause of death within 15 to 20 years.

A new generation of drugs will . aim at preventing and curing disease rather than treating symptoms. Made more by biologists and computer scientists than chemists, these drugs will be cloned from the body’s own genes, hormones, and enzymes, and will mimic nature to cure ills. The next century also will see a new wave of vaccines to prevent such illnesses as chickenpox, malaria, and hepatitis — and even tooth decay.

Viruses, which cause a range of illnesses including the common cold, herpes, and A.1.D.5., will remain a challenge. Although researchers recently described for the first time the complex architecture of a human cold virus, they are a long way from developing a vaccine for virus-related diseases. Areas of medical research with great significance for the future include:

THE BRAIN - “As heart disease and cancer become more treatable, a major health problem over the next 50 years will be degenerative diseases of the brain,” says Dr Richard Jed Wyatt, chief of neuropsychiatry at the National Institute of Mental Health. Some experts expect cases of Alzheimer’s disease, a type of dementia, to triple in the next 75 years as the population ages. But an explosion of research on the brain, one of the last frontiers of medical science, will offer eventual cures for some of today’s most feared disorders. For example, a recent discovery that the brain has

at least 50 and perhaps hundreds of neurotransmitters — chemicals that direct much of its function — probably will lead to new treatments or cures for Parkinson’s disease, epilepsy, schizophrenia, chronic pain, and even Alzheimer’s. The workings of the mind, once thought intangible and invisible, will be traced with new scanners. “We’re in the process of demystifying the brain. By the year 2000 we may know exactly what is happening, say, in my brain while I’m talking to you,” says Dr Katherine Bick, deputy director of the National Institute of Neurological and Communicative Disorders and Stroke.

Future drugs will literally refresh our memories. “Using certain drugs, we now can make animals remember better, and I believe that before long we’ll help humans with memory problems,” forecasts Dr. James L. McGaugh, director of the Centre for the Neurdbiblogy of Learning at the University of California, Irvine. Several United States drug manufacturers already are researching these “cognitive

enhancers.” One of the most ambitious areas of brain research is an effort to make a damaged brain “whole” through special surgery. Dr Wyatt has found that rats suffering symptoms of Parkinson’s disease — a deficiency of a neurotransmitter that afflicts 500,000 Americans — can recover if affected brain tissue is surgically replaced by new cells. If the process works in rhesus monkeys, Dr Wyatt believes, it eventually should work in humans. One scientist predicts that such transplants will be routine for some brain diseases by 2000 if ethical questions are resolved.

GENETICS — Gene by gene, scientists are mapping the human body. The number of identified genes is roughly doubling every two years and, although the rate will slow, many of the significant ones will have been located by the turn of the century. Last year, for example, scientists found the gene that corresponds to the fatal Huntington’s disease.

About 3500 illnesses have been linked to genetic defects, including many forms of mental retardation, and future scientists for the first time may be able to treat them. Beyond that, genetic mapping will help explain a broad range of biological functions, such as the process that causes chromosomes to rearrange themselves and trigger cancer, says one of the mappers, Dr Frank Ruddle of Yale University. Although ethical questions loom, the new knowledge should yield advances for future health care, among them genetic vaccines and drugs, prenatal screening, and early warnings of predisposition to certain adult diseases, even those caused by a combination of hereditary traits. ‘‘Now, for instance, we have to tell the whole population to cut down on fats,” says Dr Arno G. Motulsky, director of the Centre for Inherited Diseases at the University of Washington, Seattle. “When we can detect genetic predisposition to heart disease, we’ll be able to target those people at risk, and the rest may be able to eat as much fat as they want.” Many future prescription drugs will be genetically based, creations

of a “genemachine.” Now able to make a small gene in less than a day ( the device can recreate genes already in existence or synthesise genes unknown to nature, says Dr SE. Hood of the California te of Technology.

If present animal studies succeed, doctors in the twenty-first century will likely practice “gene therapy,” inserting normal genes to correct mistakes in patients’ genetic makeup. In the next year or two, the first trial of human gene therapy will be conducted on A.D.A. deficiency, a life-threatening enzyme shortage. “If gene therapy works with A.D.A., any hereditary disease could theoretically be treated with gene therapy,” says Dr W. French Anderson, chief of the National Heart, Lung, and Blood Institute’s molecular hematology laboratory. Eventually the treatment could be ,simple: “A visiting nurse could cure sickle-cell anemia in a population with injections into the bloodstream,” Dr Anderson says. Like tuberculosis and polio, most genetic disorders could be virtually banished.

Ethical concerns envelop gene therapy, especially the question of using it to change future offspring and “enhancement gene engineering” — insertion of a gene to improve a trait such as intelligence. But such tampering is unlikely, even in the distant future. “Personality and intelligence are the products of dozens of genes, along with environmental influcences,” Dr Anderson adds. “Changing them is just too complicated.”

CANCER — this complex disease will continue to kill and cripple us into the next century, but it will be more curable. The National Cancer Institute foresees that if research strategies succeed, cure rates should rise to an average of 75 per cent by the year 2000, up from about 50 per cent today. > Research is progressing in dozens of directions. Scientists now know that some cancers are , triggered by oncogenes, normal ‘ genes that turn malignant: They are starting to attack cancer with cells called monoclonal antibodies; these single-purpose molecules, armed with radioactive isotopes or

drugs, can seek out and destroy a tumor. Other pioneer treatments seek to exploit the body’s natural defenses against malignancies. Research on immune substances known as tumor necrosis factor, which destroys cancerous cells while leaving normal cells intact, may lead to radical new approaches to cancer therapy. Combinations of surgery, radiation, and chemotherapy, commonly used today, will continue to be staples of future cancer treatment, the specialists say, but they will be more refined and humane. “One of the main advances over the next 15 years will be a better way to determine who will respond to chemotherapy and who won’t,” predicts Dr Bruce A. Chabner of the National Cancer Institute. By 2000, some cancers, especially breast and ovarian cancers, should be highly curable, but lung cancer will remain a major killer. And the AJ.D.S. virus, which can lead .to malignancies, is a worrisome ques- ' tion mark in future cancer rates, Dr Chabner adds. “We’ll go about controlling cancer one disease at a time,” he says.

But there probably will be no general cure. ARTIFICIAL ORGANS - Like a repaired car, the human body of 2000 will be made up of replaceable parts. “There is no organ which won’t be replaced in the future,” says Dr Pierre Galletti, who has developed artificial organs at Brown University. Parts that will commonly be replaced in the future include heart, lungs, kidney, pancreas, blood vessels, ears, ana maybe eyes. Eventually, Dr Galletti says, man-made parte will replace the liver and even sections of the brain and nervous system. Tomorrow’s artificial organs will be made of more sophisticated materials than today’s. “Bioartificial organs,” hybrids of * natural transplants and artificial parte, may help stop tissue rejection by encapsulating donor material in plastic. Mainly because of a donor short- „ age, natural-heart, transplants will wane; says Dr Willem J.‘ Kolff of the University of Utah. Soon after 2000, he believes, thousands of people will live with miniaturised artificial hearts.