Economist: Feed a virus, starve a bacterium
经济学人：感染病毒时进食 感染细菌时禁食
燕山大学 刘立军
Science and technology: Medical treatment: Feed a virus, starve a bacterium
An old wives' tale gets some support from medical science.
Whether it is best to (Q1) feed a fever and (Q2) starve a cold, or vice versa, varies with the grandparent being asked.
Medicine has decided that it is always a bad idea to (Q3) deny food to the ill.
Now a new study suggests that by (Q4) ignoring such old wives' tales, medics may have missed a trick.
A paper just published in Cell by a team of researchers led by Ruslan Medzhitov at Yale University suggests that force-feeding mice infected with influenza (Q5) keeps them alive—but doing the same to mice with (Q6) bacterial infections is (Q7) fatal.
Dr. Medzhitov was inspired by experiments conducted not by medics, but by (Q8) zoologists.
Most animals (Q9) instinctively respond to infection by cutting back on food, and a slew of studies in recent years have shown that when diseased animals are force-fed they are more likely to die than if they are allowed to abstain.
But Dr. Medzhitov wondered whether that held true for all types of disease.
To (Q10) investigate, he and his team infected one group of mice with a murine influenza virus, and the other with Listeria monocytogenes, a bacterium that causes (Q11) food poisoning.
Some mice in each group were force-fed rodent chow, while others were force-fed nutrition-free saline.
Every single mouse that was infected with the bacterium died if they were given food, but half survived on the saline.
The (Q12) results of the viral infection were less stark, but still clear: 77.8% of infected mice survived if given food, but only 10% did so when given saline.
One clue as to what might be going on lies in the fact, identified in earlier research, that cells infected with bacteria often (Q13) prefer to burn fat instead of glucose, their usual fuel.
Further experiments led the team to confirm that glucose specifically was the key to survival in both viral and bacterial infections.
As with the rodent chow, mice with bacterial infections that were fed glucose died.
But infected mice fed a version of glucose that they could not metabolise lived.
Again, those results were nearly reversed in mice suffering from a viral infection.
All of those fed the unusable variant of glucose died within ten days; 40% of those fed the ordinary stuff (Q14) survived.
The glucose seemed to (Q15) make no difference to the bugs, nor to the (Q16) immune systems of the mice.
Instead, it altered the biology of the infected cells.
In viral infections, many infested cells were (Q17) committing suicide, a cellular scorched-earth strategy designed to slow the spread of the virus.
Providing glucose seemed to bolster their ability to fight the infection without resorting to such drastic measures.
The opposite was true for bacteria. Burning fat protected infected mice.
But swamping the cells with glucose caused them to produce prodigious quantities of highly reactive chemicals known as free radicals, which damage cells.
That collateral damage made survival less likely.
The precise biological details of why glucose is good for viral infections and bad for bacterial ones are not yet known.
And Dr. Medzhitov's results will have to be tested in (Q18) humans before medics can apply them.
But they are a useful (Q19) reminder that there is sometimes (Q20) genuine wisdom hidden in folksy homilies.
VOCABULARY
1. medic n. 医生
2. influenza n. 流感
3. slew n. 许多，大量
4. abstain v. 戒绝；抑制 If you abstain from something, usually something you want to do, you deliberately do not do it.
5. murine adj. 鼠科的
6. monocytogene n. 单核细胞增多性李司忒氏菌
7. rodent n. 啮齿动物 Rodents are small mammals which have sharp front teeth. Rats, mice, and squirrels are rodents.
8. chow n.食物 Food can be referred to as chow. 例如：Help yourself to some chow. 吃什么请自便。
9. saline n. (technical 术语) a mixture of salt in water 盐水
10. stark adj. very different to sth. in a way that is easy to see （指区别）明显的，鲜明的。例如：
· stark differences 鲜明的区别
· Social divisions in the city are stark. 城市里各社会阶层有明确的分野。
· The good weather was in stark contrast to the storms of previous weeks. 这时的好天气和前几个星期的暴风雨形成鲜明的对比。
11. glucose n. 葡萄糖 Glucose is a type of sugar that gives you energy.
12. metabolise v. 使发生新陈代谢
13. bolster v. ~ sth. (up) to improve sth. or make it stronger 改善；加强。例如：
· to bolster sb.'s confidence/courage/morale增加某人的信心 / 勇气 / 士气
· Falling interest rates may help to bolster up the economy. 利率下降可能有助于激活经济。
14. swap v. 淹没;浸没 If something swamps a place or object, it fills it with water. 例如：
· A rogue wave swamped the boat. 凶猛的海浪淹没了船只。
· The Ventura river burst its banks, swamping a mobile home park. 本图拉河的河水冲破堤岸，淹没了活动房区。
15. prodigious adj. (formal) very large or powerful and causing surprise or admiration 巨大的；伟大的。【同义词】colossal, enormous 例如：
· a prodigious achievement/memory/talent惊人的成就 / 记忆力 / 才华
· Laser discs can store prodigious amounts of information. 激光磁盘能够贮存大量信息。
【派生词】prodigiously adv. 例如：
· a prodigiously talented musician有惊人天赋的音乐家
16. collateral adj. concomitant 附带的
17. folksy adj.
(1) (especially North American English) simple, friendly and informal 淳朴友好自然的；朴实热情随意的。例如：
· They wanted the store to have a folksy small-town image. 他们希望这家商店具有小城镇那种朴实热情的形象。
(2) (sometimes disapproving) done or made in a traditional style that is typical of simple customs in the past 有民间传统的；有民间风味的；土里土气的。例如：
· a folksy ballad 有民间风味的歌谣
18. homily n. (formal, often disapproving) a speech or piece of writing giving advice on the correct way to behave, etc. （有关规矩等的）说教，说教作品。例如：
· She delivered a homily on the virtues of family life. 她进行了一场家庭生活美德方面的说教。
QUESTIONS
Fill in the blanks with the words or phrases in the news.
Science and technology: Medical treatment: Feed a virus, starve a bacterium
An old wife's tale gets some support from medical science.
Whether it is best to (Q1) ________________________ and (Q2)________________, or vice versa, varies with the grandparent being asked.
Medicine has decided that it is always a bad idea to (Q3)_______________________ to the ill.
Now a new study suggests that by (Q4) _________________________ such old wives' tales, medics may have missed a trick.
A paper just published in Cell by a team of researchers led by Ruslan Medzhitov at Yale University suggests that force-feeding mice infected with influenza (Q5) _____________ them _______________________—but doing the same to mice with (Q6) _____________________ infections is (Q7)_______________.
Dr. Medzhitov was inspired by experiments conducted not by medics, but by (Q8) ___________________.
Most animals (Q9) _______________________ respond to infection by cutting back on food, and a slew of studies in recent years have shown that when diseased animals are force-fed they are more likely to die than if they are allowed to abstain.
But Dr. Medzhitov wondered whether that held true for all types of disease.
To (Q10) _____________________, he and his team infected one group of mice with a murine influenza virus, and the other with Listeria monocytogenes, a bacterium that causes (Q11) ______________________________.
Some mice in each group were force-fed rodent chow, while others were force-fed nutrition-free saline.
Every single mouse that was infected with the bacterium died if they were given food, but half survived on the saline.
The (Q12) _____________________ of the viral infection were less stark, but still clear: 77.8% of infected mice survived if given food, but only 10% did so when given saline.
One clue as to what might be going on lies in the fact, identified in earlier research, that cells infected with bacteria often (Q13)_____________________ fat instead of glucose, their usual fuel.
Further experiments led the team to confirm that glucose specifically was the key to survival in both viral and bacterial infections.
As with the rodent chow, mice with bacterial infections that were fed glucose died.
But infected mice fed a version of glucose that they could not metabolise lived.
Again, those results were nearly reversed in mice suffering from a viral infection.
All of those fed the unusable variant of glucose died within ten days; 40% of those fed the ordinary stuff (Q14) ______________________.
The glucose seemed to (Q15) _________________________ to the bugs, nor to the (Q16) _____________________________ of the mice.
Instead, it altered the biology of the infected cells.
In viral infections, many infested cells were (Q17)______________________________, a cellular scorched-earth strategy designed to slow the spread of the virus.
Providing glucose seemed to bolster their ability to fight the infection without resorting to such drastic measures.
The opposite was true for bacteria. Burning fat protected infected mice.
But swamping the cells with glucose caused them to produce prodigious quantities of highly reactive chemicals known as free radicals, which damage cells.
That collateral damage made survival less likely.
The precise biological details of why glucose is good for viral infections and bad for bacterial ones are not yet known.
And Dr. Medzhitov's results will have to be tested in (Q18)____________________ before medics can apply them.
But they are a useful (Q19) ________________________ that there is sometimes (Q20) ________________________________ hidden in folksy homilies.
KEY
| Question | Key |
| Q1 | feed a fever |
| Q2 | starve a cold |
| Q3 | deny food |
| Q4 | ignoring |
| Q5 | keeps … alive |
| Q6 | bacterial |
| Q7 | fatal |
| Q8 | zoologists |
| Q9 | instinctively |
| Q10 | investigate |
| Q11 | food poisoning |
| Q12 | results |
| Q13 | prefer to burn |
| Q14 | survived |
| Q15 | make no difference |
| Q16 | immune systems |
| Q17 | committing suicide |
| Q18 | humans |
| Q19 | reminder |
| Q20 | genuine wisdom |