Prognosis good for more medical breakthroughs

THE BALTIMORE EVENING SUN

THE PROSPECT of relieving human suffering has never been greater, thanks to an unprecedented bounty of medical breakthroughs. Recent advances are not only quelling the demons of the mind and soothing the agonies of the flesh, but they are promising to change the very way medicine is practiced.

A revolution is in the offing. For the first time, physicians have access to the genetic code -- the cornerstone of an individual's health -- and they are using it to steer a new course for medicine.

They can now look for the genes that are involved in almost all diseases and devise ways to prevent those diseases from occurring. Or they can use the genes to duplicate the body's own pharmacy -- the hormones and proteins that keep it operating in good repair -- to restore health.

Meanwhile, some of medicine's most recalcitrant problems already are beginning to dissolve under the onslaught of new technologies and new discoveries.

In the last year and a half, for instance, new drugs, some of them already the fruits of genetic engineering, are enabling doctors to such things as subdue previously untreatable cases of schizophrenia, preventstrokes and spinal-cord injury paralysis, and reverse heart disease and some crucial aspects of aging.

Following are some of the most promising recent developments that have the remarkable ability to save lives, prevent incapacitation and improve the quality of life.

The gene machine

Using the powerful tools of molecular biology, scientists are busy searching for disease-causing genetic defects with startling success and are devising ways to correct them. The gene that causes cystic fibrosis, for example, was discovered by researchers from the University of Michigan and Toronto Children's Hospital in September 1989.

A year later, other scientists from the Universities of Michigan and Iowa used gene therapy to cure cystic fibrosis in the laboratory, opening the door to the first effective treatment for the most common inherited disease in North America.

The floodgates opened. In rapid order, scientists discovered the genes responsible for causing osteoarthritis, which affects 16 million Americans; spinal muscular atrophy, a childhood crippler; Alport syndrome, which affects the kidneys; and hypertrophic cardiomyopathy, a disease that can lead to a ruptured aneurysm (the cause of death for college basketball star Hank Gathers).

For many of these diseases, discovering their genetic roots means they no longer are hopeless disorders. Typical of the change is the old pessimistic view that osteoarthritis was due to the inevitable wear and tear on joints. That notion is being replaced by the discovery of the disease's genetic flaw, and that is going to lead to a lot more promising research in ways to prevent the crippling disorder.

Nobel Laureate James D. Watson, co-discoverer of the double helix structure of genes and director of the National Center for Human Genome Research, is spearheading a $3-billion, 15-year effort to decipher the approximately 100,000 genes that orchestrate the construction and maintenance of every human.

Of all the advances in genetic medicine, none is more exciting than gene therapy.

Anti-aging drug

Increasing frailty, marked by the loss of muscle, was thought to be an inescapable price of aging. But two teams of researchers have shown that is not necessarily so and that elderly people can regain some of their lost muscle power and vigor.

The most dramatic turnaround was reported in July by researchers from the Medical College of Wisconsin in Milwaukee, who injected 21 men between the ages of 61 and 81 with human growth hormone. The experiment only became possible with the development of genetic engineering, which made ample supplies of the hormone available for the first time. The hormone, secreted by the pituitary gland, declines as people age. The test subjects had stopped making it altogether.

Within six months the patients regained as much muscle mass as they had lost over the preceding two decades, and they reported feeling better, Dr. Daniel Rudman says. Furthermore, the new muscle growth came from fat deposits, thereby reducing unwanted flab, he says.

Experts warn, however, that although these findings are encouraging, they are not a fountain of youth. More research will have to be done to determine just how valuable growth hormone may be in reversing one of the biggest signposts of aging.

Ready for immediate use as a muscle builder is exercise. Maria Fiatarone and her Tufts University colleagues found that intense weight training had a similar effect as growth hormone. Elderly subjects who exercised for 15 minutes three times a week, doing such things as lifting nearly 50-pound weights with their legs, showed increased muscle strength and size. After eight weeks their walking pace speeded up by 50 percent.

Preventing strokes

A clot-thinning drug that costs less than 50 cents a day may be able to prevent between 43,000 and 64,500 strokes each year, according to the results of a multicenter study. Such a reduction could reduce the nation's hospital bill by $500 million

annually.

In tests with 420 patients with atrial fibrillation, a common heart disorder that greatly increases the risk of stroke, the blood-thinner warfarin was 86 percent effective in preventing strokes, Dr. J. Philip Kistler of Massachusetts General Hospital reported.

Reversing heart disease

The first conclusive evidence that cholesterol-lowering drugs along with dietary control can reverse heart disease in women was reported in late 1990, about a year after similar results were reported in men. These findings come on top of earlier ones showing that lowering the bad form of cholesterol, known as low-density lipoproteins, can retard the buildup of fatty de

posits in the coronary arteries.

The latest good news supports the belief that lowering cholesterol levels will delay or reverse atherosclerosis and thus ward off heart disease, says Dr. John P. Kane of the University of California at San Francisco, who headed the cholesterol-lowering study in women.

AZT -- Anti-AIDS drug

AZT, the only approved anti-AIDS drug, took on an important new role in medicine's campaign to change AIDS from a fatal disease into a treatable one. Based on studies showing that lower doses of the drug significantly slow the progression of AIDS in patients with early symptoms and delay the onset of symptoms in infected persons, federal health officials are recommending wider use of AZT.

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