VOA标准英语2012--Math May Determine Best HIV Drug Combinations

Math May Determine Best HIV Drug Combinations

Treating people infected with the AIDS virus involves using a combination of antiretroviral drugs. But some combinations work better than others. Now, a mathematical formula has been developed that may eventually help doctors decide which drugs to use.
Prescribing a cocktail¹ of drugs has become the gold standard in preventing HIV from replicating². It’s called HAART, which stands for highly active antiretroviral therapy. The cocktail combinations may be changed periodically to prevent the virus from building up resistance.
The new math
The new mathematical formula is based on a 5-year analysis of how the drugs keep HIV in check.
Dr. Robert Siliciano, senior study investigator³ and a specialist in infectious disease, said, “I’ve always been interested in why some combinations of HIV drugs work well and some don’t. Most of the progress in the HIV treatment field in terms of deciding which treatments should be used in patients has been based on empirical studies – trial and error clinical trials – in which different combinations are tested against each other. And you look at how many patients after one year of treatment have (an) undetectable level of virus.”
Siliciano is a professor of medicine at Johns Hopkins University.
“There hasn’t been a lot of theoretical basis of why some combinations should work better than others. [With] what we know about how the virus replicates⁴, it should be possible at least to predict some aspects of treatment outcome, specifically how well the drugs actually inhibit⁵ the virus,” he said.
What works, what doesn’t
The study analyzed⁶ how well individual drugs and drug combinations inhibit infection. Researchers then fed that data into computers and applied⁷ their mathematical formula.
“The standard way to do this is to look at the amount of drug that gives you 50 percent inhibition. That turns out to be a very poor way of doing it because at least some of the drugs are actually extremely good and they cause way, way more than 50 percent inhibition,” he said.
In fact, some drugs are more than 99 percent effective in inhibiting⁸ HIV from replicating. Those are the antiretrovirals included in the study.
“Because the virus replicates exponentially,” said Siliciano, “it can increase very, very quickly, and so that’s why you need that extremely high level of inhibition.”
Siliciano and his fellow researchers used 19 drugs and came up with well over 800 treatment combinations. He said while more study of the mathematical formula is needed, he foresees two uses. The first, of course, is treatment.
“Actually most of the people who have HIV infection are not on treatment right now. And treatments are not available in many areas. And the treatments are very costly⁹ and complicated. So if you really understand how well individual drugs and drug combinations work, it may be possible to figure out what is the simplest treatment that would be effective and that could be made more widely available,” he said.
The formula could also help prevent drug resistance.
“Resistance is a very big problem when people either don’t get an adequate supply of drugs or don’t take the drugs correctly. Resistance can develop very easily. And the current ways of evaluating what to do for patients who have resistance need to be improved and this mathematical analysis I think gives us a way to do that,” he said.
He said the next focus will be to come up with a drug regimen against which HIV is unable to develop any resistance.

1 cocktail   

n.鸡尾酒；餐前开胃小吃；混合物

参考例句：

• We invited some foreign friends for a cocktail party.我们邀请了一些外国朋友参加鸡尾酒会。
• At a cocktail party in Hollywood,I was introduced to Charlie Chaplin.在好莱坞的一次鸡尾酒会上，人家把我介绍给查理·卓别林。

2 replicating   

复制( replicate的现在分词 )； 重复； 再造； 再生

参考例句：

• Applications create these partitions for storing and replicating data. 应用程序创建这些分区用来储存和复制数据。
• The closest real things to these creatures were bits of self-replicating RNA. 最贴近这些造物的实物是能做一点微不足道的自复制的核糖核酸。

3 investigator   

n.研究者，调查者，审查者

参考例句：

• He was a special investigator for the FBI.他是联邦调查局的特别调查员。
• The investigator was able to deduce the crime and find the criminal.调查者能够推出犯罪过程并锁定罪犯。

4 replicates   

复制( replicate的第三人称单数 )； 重复； 再造； 再生

参考例句：

• The bluetongue virus replicates in the insect. 蓝舌病病毒在这种昆虫体内繁殖。
• The chameleon's skin replicates the pattern of its surroundings. 变色龙的皮肤可随环境的模式而改变颜色。

5 inhibit   

vt.阻止，妨碍，抑制

参考例句：

• Don't let ego and greed inhibit clear thinking and hard work.不要让自我和贪婪妨碍清晰的思维和刻苦的工作。
• They passed a law to inhibit people from parking in the street.他们通过一项法令以阻止人们在街上停车。

6 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

7 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

8 inhibiting   

抑制作用的，约束的

参考例句：

• The high cost of borrowing is inhibiting investment by industry in new equipment. 借款的高成本抑制了企业对新设备的投资。
• The pesticides affect the nervous system by inhibiting the enzyme cholinesterase. 这类农药抑制胆碱酯酶而影响神经系统。

9 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。