TIME EUROPE
January 15, 2000, Vol. 157 No. 2
The Hunt for Cures
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10
That story, in fact, has inspired trials of nearly two dozen new biotech medicines. IDEC Pharmaceuticals in San Diego, for example, has zeroed in on the interactions between cd4 T cells and apcs to make antibody drugs against lupus and RA. The company's anti-RA antibody selectively switches off T cells involved in autoimmune responses by binding the cd4 molecule on their surfaces. Amgen, of Thousand Oaks, Calif., has a drug that blocks Interleukin-1, another molecule that promotes inflammation.
Thanks to technologies spawned by genomics, the list of potential drug targets is growing rapidly. Human Genome Sciences and Seattle-based ZymoGenetics, for instance, are independently developing drugs to inhibit a newly discovered factor that stimulates B cells and is produced copiously in RA and lupus patients.
Encouraged by these successes, drug companies are starting to turn to the lesser known autoimmune diseases. Remicade, for example, is used to alleviate the intestinal inflammation caused by Crohn's disease, and drugs against the potentially systemic disorders scleroderma and Sjogren's syndrome are well along in clinical trials. None of these treatments is a cure, of course, but anything that can put the brakes on a runaway immune system has to be considered a good start.
Obesity
Healthy Genes Could Mean Smaller Jeans
By JEFFREY KLUGER
If you don't have a weight problem, you have more than your diet or your gym to thank. You also owe a nod to your leptin gene. And while you're at it, tip a hat to your mc4 receptors and your pc1 enzymes and your pomc peptides. Hard to figure out the role this alphabet soup of stuff plays in helping keep you thin? Don't feel bad. It's all new to scientists too.
Nutritionists know that the two great pillars of weight control ‹ diet and exercise ‹ can't be all there is to avoiding obesity. Why else could two otherwise healthy people eat identical foods, keep identically active and still see the numbers on the scale move in opposite directions? For years much of this has been explained with hand-waving references to body types and metabolism ‹ broadly accurate, but cold comfort to the estimated 61% of Americans who are overweight or obese and want to have their weight controlled, not merely explained.
Now, however, explanations are coming. As scientists hack deeper into the underbrush of the human genome, they are at last beginning to understand the genetics of weight regulation ‹ and how the whole system can go awry. With that understanding, they believe, it may be possible to develop drugs that do the job balky genes fail to do ‹ controlling a problem that decades of fad diets and self-help books have never solved. Says molecular biologist Jeffrey Friedman of the Howard Hughes Medical Institute at Rockefeller University in New York City: "Genomics will identify the players in this system, eventually leading to new targets and new treatments."
It was the discovery of leptin in 1994 that got the genetic study of obesity rolling, and it was Friedman's research team that was responsible. Studying the genome of a rare strain of hugely obese mice, the investigators found that all of them shared a defect in a gene that coded for a previously unknown hormone released by body fat. When a normal animal gains too much weight, the hormone signals the brain to turn down the appetite rheostat. When fat stores drop, the hormone is shut off, causing appetite to rebound. In the gene-damaged mice, there was no leptin at all, causing them to eat and eat without satiation. "We called the hormone leptin," Friedman says, "after the Greek word leptos, for thin."
The announcement of leptin's discovery was big news to biologists, particularly after Friedman administered it to the obese mice and saw their weight drop by a dramatic 30% within as little as two weeks. A next, obvious step was to look for humans with the same defective gene. In Britain, endocrinologist Stephen O'Rahilly of the University of Cambridge did find a pair of leptin-deficient children, one of whom at age 9 weighed a staggering 208 lbs. After modest leptin treatments were begun, both children began dropping weight at a steady rate that sometimes exceeded 4 lbs. a month.
So leptin is the answer to obesity ‹ right? Not quite. Only a tiny percentage of obese people have a defect in the leptin gene. Clinical trials with leptin treatments conducted by Amgen, a biotech in Thousand Oaks, Calif., have led to weight reduction in some subjects, but the drug does not remain in the body long enough to do any lasting good. While more testing is under way using a leptin drug with a longer half-life, many scientists are coming to believe that the real secret may be found not in leptin itself but in the complicated steps it follows as it does its appetite-regulating work.
MORE >>
For more stories from TIME's special report, check out time.com/health
This edition's table of contents
TIME Europe home
More stories from TIME Europe and related links
E-mail us at mail@timeatlantic.com
Like what you're reading?
Click here to try 4 FREE ISSUES of TIME
|
|
|
|
COVER STORY
Special Report: The Future of Medicine
With the mapping of the human genome the process by which new drugs are developed is being turned upside down. These drugs will also change our lives
Brave New Pharmacy
Using high-speed robots and the secrets of the human genome, scientists are changing forever the way they discover new medicine
The Hunt for Cures
Genetic information could lead to treatments for everything from AIDS to obesity
EUROPE
Prague Winter
When Jiri Hodac was named director of state television, Czech journalists saw a return to government meddling in the media
See Vous in Court
France is the latest nation to join the litigation game
Going up in Smoke
Switzerland, land of luxury watches and bank secrecy, has a new growth industry: marijuana
UNITED STATES
The True Blue Bush Cabinet
Its ethnic and gender balance is correct, but can a divided nation deal with the superconservative bent?
BUSINESS
Transparency has its Price
Executives at many German companies are finding it hard to adjust to the more rigorous financial disclosure required by global investors
On Spreading the Word
When it comes to selling merchandise, word-of-mouth marketing may be a company's best weapon
Essay: Meat Matters
Critics of industrialized farming may be forgetting about world hunger, writes TIME's Rod Usher
THE ARTS
Rebel with a Cause
The real-lifestory of an anti-Mafia activist in Sicily makes for a handsome film with a political message
The Upmarketeer's Tale
Bernard Arnault built his house by selling at deluxe prices and in his book he's still giving nothing away
The Art of Noise
For Europe's freely improvised music, the only rule is no rule
DEPARTMENTS
Techwatch
World Watch
WHAT DO YOU THINK?
E-mail us at mail@timeatlantic.com
|
|
