美国国家公共电台 NPR Doctor Launches Vision Quest To Help Astronauts' Eyeballs

 

SCOTT SIMON, HOST:

You would expect a trip into space would change a person - their heart, their soul, but their eyeballs? For years, a north Texas doctor has been trying to find out what causes this vision change among astronauts. Her latest research may provide some clues. Lauren Silverman from member station KERA in Dallas reports.

LAUREN SILVERMAN, BYLINE¹: After spending six months on the International Space Station, Michael Barratt had a strange request when he finally stepped foot on Earth. He wanted a spinal² tap.

MICHAEL BARRATT: Yep, it ranked right up there with a hot shower.

SILVERMAN: Barratt isn't a masochist. He's a NASA astronaut who, while flying hundreds of miles above the Earth in 2009, noticed his vision was changing. He was struggling to read checklists.

BARRATT: When you're reading in Russian, in small print, in a dark place and your visual acuity³ starts to tank, I mean, you notice it (laughter).

SILVERMAN: Barratt is also a curious physician, which brings us back to his request for a spinal tap to check the pressure in his brain. He knew he wasn't the first astronaut whose vision had changed while in space. And he hoped sticking a needle into his back might provide a clue to his vision loss. The theory - micro-gravity raises pressure in the head and reshapes the eyeballs.

BARRATT: This is a medical issue that affects a large percentage of people who fly in space and for which we are now making very expensive mission decisions - how we're going to go to Mars and whatnot - so the stakes are extremely high.

SILVERMAN: Scientists know that when people go into space, the fluid normally below their hearts goes into their heads. But is it creating enough pressure to damage the eyes, to squish them and affect the optic nerve? Dr. Benjamin Levine has been on a mission to find out at UT Southwestern Medical Center and Texas Health Resources in Dallas. Instead of sticking needles in astronauts' backs, though, he wanted to stick them inside people's brains.

BENJAMIN LEVINE: Basically - and that's what we did. We didn't actually do the drilling, but we found people who'd had holes put in their brain.

SILVERMAN: Levine found eight healthy cancer survivors⁵ who already had ports in their heads - once used to deliver chemotherapy. Then he convinced them to get on a plane for a sort of extreme rollercoaster ride to simulate zero gravity.

UNIDENTIFIED MAN #1: (Unintelligible).

SILVERMAN: You know that feeling of weightlessness when you drop on a roller coaster?

UNIDENTIFIED MAN #2: Woo.

SILVERMAN: Well, these folks did that except they plunged⁶ 8,000 feet in 30 seconds, dozens of times, all in the name of science.

TRENT BARTON: I enjoyed each and every rotation⁷ that we did.

SILVERMAN: Trent Barton, a lymphoma survivor⁴ from Dallas, went on the wild trip above the Texas-Mexico border. Here he is talking during the car ride after the flight.

BARTON: And that was a lot gadgets⁸ on me. I had things hooked up to both arms. This blood pressure on my finger that was literally⁹ tracking blood in and out of my finger.

SILVERMAN: Most importantly, he had a needle in that port in his head monitoring the pressure in the fluid surrounding his brain. Remember, they're testing the hypothesis that pressure inside the brain at zero gravity is so high it damages the eyes and...

LEVINE: The main idea is wrong.

SILVERMAN: Turns out, Levine says, spaceflight doesn't cause pressure to be that much higher than it is when you or I are standing¹⁰ up. But it is a little higher. The research is published in The Journal of Physiology¹¹.

LEVINE: We now think that perhaps this mild but persistent¹² pressure may be the thing that's stimulating¹³ remodeling behind the eye and causing the visual impairment.

SILVERMAN: See, unlike us earthlings, astronauts never get to rest their brains in lower pressure. When they're standing up, the fluid won't go to their feet. So researchers like Levine are now trying to find a way to give these astronauts' brains a rest.

LEVINE: We've been working with Under Armour¹⁴, the garment company, to come up with a soft, almost like a sleeping sack or a pair of trousers, that you can put on at night, hook up to a vacuum cleaner, suck the blood and the fluid into the feet and unload the heart and the brain while you're sleeping.

SILVERMAN: Astronaut and doctor Mike Barratt says he'd be willing to try the sleeping sack, but he also wants to do more tests on the International Space Station to better understand intracranial pressure, especially before we send astronauts deeper into space. As for his eyesight six years post-fight...

BARRATT: It's my right eye that has apparently¹⁵ been permanently¹⁶ remodeled. Other than that, I'm totally normal.

SILVERMAN: He's still the same curious doctor. He just sees things a bit differently since returning to Earth. For NPR, I'm Lauren Silverman in Dallas.

1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

3 acuity   

n.敏锐，（疾病的）剧烈

参考例句：

• We work on improving visual acuity.我们致力于提高视觉的敏锐度。
• The nurse may also measure visual acuity.护士还可以检查视敏度。

4 survivor   

n.生存者，残存者，幸存者

参考例句：

• The sole survivor of the crash was an infant.这次撞车的惟一幸存者是一个婴儿。
• There was only one survivor of the plane crash.这次飞机失事中只有一名幸存者。

5 survivors   

幸存者，残存者，生还者( survivor的名词复数 )

参考例句：

• The survivors were adrift in a lifeboat for six days. 幸存者在救生艇上漂流了六天。
• survivors clinging to a raft 紧紧抓住救生筏的幸存者

6 plunged   

v.颠簸( plunge的过去式和过去分词 )；暴跌；骤降；突降

参考例句：

• The train derailed and plunged into the river. 火车脱轨栽进了河里。
• She lost her balance and plunged 100 feet to her death. 她没有站稳，从100英尺的高处跌下摔死了。

7 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

8 gadgets   

n.小机械，小器具（ gadget的名词复数 ）

参考例句：

• Certainly. The idea is not to have a house full of gadgets. 当然。设想是房屋不再充满小配件。 来自超越目标英语 第4册
• This meant more gadgets and more experiments. 这意味着要设计出更多的装置，做更多的实验。 来自英汉非文学 - 科学史

9 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

10 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

11 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

12 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

13 stimulating   

adj.有启发性的，能激发人思考的

参考例句：

• shower gel containing plant extracts that have a stimulating effect on the skin 含有对皮肤有益的植物精华的沐浴凝胶
• This is a drug for stimulating nerves. 这是一种兴奋剂。

14 armour   

（=armor）n.盔甲；装甲部队

参考例句：

• His body was encased in shining armour.他全身披着明晃晃的甲胄。
• Bulletproof cars sheathed in armour.防弹车护有装甲。

15 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

16 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。