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【medical-news】哈佛医学院：2007年五大医学事件
Important scientific breakthroughs are often the result of several discoveries coming together in just the right combination. So it is with our five nominees for health and medical significance in 2007. Several items on our list have come about because of the slow, steady accretion of basic research findings and trial results. Some involve politics, which is almost always a grind — especially when it comes to health care. And with some we’re intentionally marking trends, not a single event. Sometimes the Eureka moments come when you realize that there isn’t always a splashy breakthrough but many events on a continuum — a lot that came before and even more to follow.
1. Did we learn a lesson from Avandia?
The FDA is supposed to allow drugs on the market only if they are safe and effective. In 2007, rosiglitazone (Avandia), became the latest medication found to have serious side effects that weren’t apparent when it was approved.
Like insulin and other diabetes drugs, rosiglitazone and a similar drug, pioglitazone (Actos), lower blood sugar. Studies published in 2007 confirmed some earlier evidence that both drugs could, in rare instances, cause liver and heart failure. The surprise came with study results showing that rosiglitazone — but not pioglitazone — markedly increases the risk of heart attack, as well as overall risk of dying from heart disease. The absolute risk is small: about one additional heart attack or cardiac death in 1,000 people taking the drug. The FDA put a “black box” warning on it, but rosiglitazone stayed on the market, unlike rofecoxib (Vioxx), the COX-2 painkiller that was pulled off in 2004 when it was found to cause heart problems.
No drug is entirely safe, and it would be impractical to require studies large enough to identify all of a drug’s problems as a condition of approval. Instead, the FDA needs more money — and clout — to make sure drugs are monitored for safety after they’re on the market and to take prompt action if necessary. Congress passed legislation in 2007 that would give the agency that funding and power, as well as make some other important reforms (a requirement that all clinical trials be recorded in a central registry, for example). Time will tell whether these changes make a difference and restore lost confidence in medication safety.
2. Waking up to a new health habit: Sleep
None of us needs a study to tell us that we feel better after a good night’s sleep. But research is showing that getting enough sleep — between seven and nine hours a night for most people — is one of the pillars of good health, along with exercise, eating plenty of fruit and vegetables, and staying slim.
No one study made a big splash in 2007, but the evidence has reached a critical mass. Studies have linked short and poor sleep to many modern maladies: diabetes, heart disease, high blood pressure, inflammation, stroke. Short sleep may be a factor in the obesity epidemic: sleep lab studies have shown that it alters the activity of leptin, the “fullness” hormone, and ghrelin, the “appetite” hormone.
Meanwhile, scientists are beginning to understand the sleeping brain and the role it plays in our mental lives and health. One popular theory is that we need sleep to store — and possibly attach meaning to — our memories. So if you make sleep a priority, you might improve your memory and your health.
3. Putting out the fire
When it’s under control, inflammation is a normal part of our immune response. But when it gets out of control, inflammation causes disease and pain, and fanning the flames is a protein called tumor necrosis factor-alpha (TNF-alpha).
In the 1990s, researchers genetically engineered a protein that blocks TNF-alpha. The FDA approved the fruits of this labor, etanercept (Enbrel), in 1998.
Now two others — infliximab (Remicade) and adalimumab (Humira) — are on the market, and a third — certolizumab — is waiting in the wings.
The medications have greatly improved the treatment of several inflammatory conditions, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis (a condition that affects the spine and the sacroiliac joints), and Crohn’s disease, a bowel disorder. A combination of a TNF-alpha blocker and methotrexate, a standard antirheumatic drug, is twice as effective as methotrexate alone in the treatment of rheumatoid arthritis. Sales of the TNF-alpha blockers have more than tripled since 2002, according to IMS Health.
The TNF-alpha blockers have serious drawbacks: they’re expensive ($10,000 to $25,000 annually per patient), can result in serious infections, and have been linked to cancer, particularly lymphoma. But by tackling inflammation at its roots, they may be paving the way for a new approach to treating many diseases. In 2007, National Institutes of Health researchers proposed using TNF-alpha inhibition to treat brain diseases with an inflammatory component, such as Alzheimer’s and Parkinson’s disease.
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作者:admin@医学,生命科学 2011-05-07 05:14
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