科学家尝试开发治疗嗜睡病新药

短语讲解：

1. Brain infection leads to inflammation and death.

lead to导致, 引起
例句：An ordinary cold can soon lead to a fever.
一场普通的感冒很快便会引起高烧。

2. So Kennedy and his colleagues combined melarsoprol with another chemical, cyclodextrin.

combine with与…结合
例句：If he can combine his ability with hard work, he should be very successful.
如果他能把自己的才能和勤奋结合起来, 必定会很有成就。

3. And we believe - although we don't know for sure - that one of the main reasons why it's less toxic is that there isn't this sudden rush of drug into the body, and thereby producing less toxic effects.

for sure无疑
例句：The fighting was over for sure.
战斗确实结束了。

4. In testing on laboratory mice, Kennedy says the combination retained the effectiveness of melarsoprol, without the frequently fatal side effects.

side effect副作用
例句：This medicine has no side effect.
这种药没有副作用。

5. If it all works out, he says the melarsoprol-cyclodextrin combination could lower the cost of treatment by reducing hospital stays.

work out作出; 制订出
例句：The plan has already been worked out, and could be put into operation at a moment's notice.
计划已经拟好并立即可以付诸实施。