PBS高端访谈:阿尔茨海默症的发现及预防

 　　JUDY WOODRUFF: Alzheimer's disease remains 1 among the most devastating 2 diseases that medicine has yet to crack. There's no known cure or treatment that has substantially helped curb 3 memory loss and the decline in cognitive 4 skills. One in eight Americans over the age of 65 has Alzheimer's now.

　　Researchers are hoping they can find a more promising 5 future by intervening well before any symptoms show.
　　Jeffrey Brown has the story.
　　JAMIE TYRONE: This photograph is a picture of my father and myself at a father/daughter dance at school.
　　JEFFREY BROWN: At age 48, Jamie Tyrone decided 6 on a whim 7 to sign up for a study that offered genetic 9 testing for 22 diseases.
　　JAMIE TYRONE: This is at my wedding day.
　　10 ways to eat and drink your way to a better brain
　　JEFFREY BROWN: The results were shocking and life-changing.
　　JAMIE TYRONE: My genetic status is that I have a 91 percent lifetime risk of getting Alzheimer's disease.
　　JEFFREY BROWN: Alzheimer's, a debilitating 10 form of dementia, wasn't even on Tyrone's radar 11 screen. She'd had no symptoms. And hearing the news sent her into an emotional tailspin.
　　JAMIE TYRONE: I was very, very lonely and very, very isolated 12. And at one point, I was told that it's probably best not to talk about it because you might be discriminated 13 against. And so I went into a really dark hole.
　　JEFFREY BROWN: All this began five years ago, ironically, just as her father began showing signs of mental confusion.
　　JAMIE TYRONE: Want to look up at me, dad? I'm taking a picture of you.
　　JEFFREY BROWN: Tyrone watched as his health quickly declined. He was eventually diagnosed with Alzheimer's.
　　JAMIE TYRONE: When my father was still alive, and I looked at him, all I saw was my destiny. And I was frightened for me, but I was more afraid for my family, because I didn't want -- I didn't want them to go through what we were going through with my father.
　　JEFFREY BROWN: And her story is now part of a new approach to experimental Alzheimer's research, treating people for the disease before they show a single symptom.
　　WOMAN: I'm going to ask you a bunch of questions that just look at various aspects of memory and thinking. And I want you to just take your time and relax.
　　JEFFREY BROWN: Tyrone volunteered for a biomarker study at Banner Alzheimer's Institute in Arizona. Here, she is given cognitive tests, medical screening, and brain imaging.
　　JAMIE TYRONE: I panic every time I go through it, because I'm like, oh, my goodness, if I forget something, do I have Alzheimer's?
　　WOMAN: Immediately, you were able to recall that.
　　JEFFREY BROWN: So far, her tests have been encouraging.
　　WOMAN: So, you got 27 out of 30, which is considered normal.
　　JAMIE TYRONE: Yay!
　　JEFFREY BROWN: The biomarker study Tyrone entered is part of an ambitious goal set by Banner to prevent and even eradicate 14 the disease.
　　DR. PIERRE TARIOT, Director, Banner Alzheimer's Institute: It's incurable 15, it's debilitating, it's relentless 16, and it's unacceptable.
　　JEFFREY BROWN: Dr. Pierre Tariot is on a team of doctors that launched the Alzheimer's prevention initiative.
　　We think the best way to find an end to Alzheimer's disease, without losing another generation, is moving earlier. The most important studies to do are in people that don't have any manifest symptoms yet.
　　JEFFREY BROWN: One new study will involve people with no symptoms, but at high risk, because they carry two copies of a gene 8 called APOE-e4.
　　DR. PIERRE TARIOT: There's credible 17 evidence that lifestyle variables matter.
　　JEFFREY BROWN: And while Jamie Tyrone fits that genetic profile, she is too young to participate. The trial will track people 60 to 75 years old.
　　DR. PIERRE TARIOT: If we learn that making this red goes away or preventing it from even occurring...
　　JEFFREY BROWN: Last summer, the study received a big boost, $33.2 million from the National Institutes of Health.
　　DR. PIERRE TARIOT: We and others really think that the way to put this disease behind us is to find therapies that attack the underlying 18 biology, and apply them in the right way at the right time. And if we can do that, we may be able to help preserve identity and preserve autonomy, which are the goals.
　　The areas that are blue are essentially 19 little amyloid protein deposits.
　　JEFFREY BROWN: One long-held hypothesis is that a buildup of amyloid protein in the brain is the main culprit in the onset 20 of Alzheimer's. These new trials will test drugs aimed at halting that progression.
　　DR. PIERRE TARIOT: We will be comparing change in people who get active treatment vs. a placebo 21 or sham 22 treatment, and our hypothesis is the active experimental treatment will slow down or possibly even prevent the otherwise almost certain loss of memory and other thinking ability.
　　JEFFREY BROWN: To this point, drug trials to treat people who already have the disease have proven disappointing, thus the change in thinking.
　　DR. PIERRE TARIOT: There has been a significant paradigm 23 shift in just the last couple of years. Maybe using these promising experimental agents at a time when the disease has already ravaged 24 the brain is too late, so maybe what we ought to do is intervene at the very beginning, before the damaged has occurred, and before symptoms have emerged. And so that's a big change. That's a real pivot 25 in the field.
　　JEFFREY BROWN: It also raises new ethical 26 considerations to administer Alzheimer's treatment to people with no current symptoms.
　　DR. PIERRE TARIOT: In every case, it boils down to the ability for everybody to appreciate the potential risks and the potential benefits, benefits for oneself, benefits for one's family or future generations.
　　WOMAN: You're going to draw trees in the background. Yours is looking great.
　　JEFFREY BROWN: For people who already have Alzheimer's, the institute creates environments, like this art class, where patients can feel productive and successful.
　　JAN DOUGHERTY, Family and Community Services, Banner Alzheimer's Institute: I think it works for people with Alzheimer's because every day they face failure, because their memory, their brain can't keep pace. But as I tell people with this disease, look, not all of your brain is not working. There are parts that work beautifully, and I think art is one of those areas that work beautifully
　　JEFFREY BROWN: According to the Alzheimer's Association, 5.2 million Americans are affected 27 by the disease. A new diagnosis 28 is made every 68 seconds, and the number of cases is expected to triple by 2050.
　　DR. PIERRE TARIOT: The World Health Organization has labeled Alzheimer's disease as the coming pandemic of Western societies in this century, predicting that as we age successfully, the numbers will become so extraordinary that unless we find a way to put it behind us, it could overwhelm our societies.
　　JEFFREY BROWN: Feeling overwhelmed by her husband's diagnosis is something Judy Starbuck is familiar with.
　　JUDY STARBUCK: I have periods of great grief, great grief, of loss. You know, they say start planning to make a life for yourself. And I don't want to.
　　JEFFREY BROWN: Starbuck volunteered for the prevention trials, but was found to carry no risk and therefore didn't qualify. In fact, researchers acknowledge it may be tricky 29 to find volunteers. So the Banner Institute has created an online Alzheimer's prevention registry.
　　JESSICA LANGBAUM, Principal Scientist, Banner Alzheimer's Institute: One of the biggest challenges is just finding enough people to participate. Typically, research studies often take place in people who already have the disease, and here we're trying to do prevention-focused studies.
　　JEFFREY BROWN: Jamie Tyrone says she can't help being optimistic.
　　JAMIE TYRONE: Oh, my goodness. What it means is that there's hope, there's actual hope. There is a possibility that there may be a prevention in my lifetime, and my family won't have to go through what we have in the past. So, that's very, very promising and very, very exciting.
　　JEFFREY BROWN: The prevention trials are expected to begin in 2015.
　　GWEN IFILL: You can learn more about Alzheimer's prevention, including how to eat your way to a healthier brain. That's on our Health page.