阅读理解

　　Scientists say they were able to reduce the effect of the AIDS with a drug first designed to treat other conditions．AIDS damages the protection system so the body cannot fight viruses inside the body．At present, medicines can reduce HIV to levels low enough to keep people alive．But these drugs are not a cure．Small amounts of the virus still remain in human’s body．If it wakes up again, the virus can become active and begin to copy itself, so people must continue to take medicine．

　　A new study has been carried out on four patients．They had already taken medicine for more than two years．The researchers first improved the effect of the drug．Then in addition, they gave the patient another one, valproic acid(丙戊酸)．Valproic acid is used to help epilepsy(癫痫病)patients．Some people with depression(抑郁症)also take the drug to calm themselves down．

　　But valproic acid has also been shown to block something that helps HIV, the AIDS virus, to hide．The patients took the medicine twice a day for three months．

　　Over this time, the researchers say the amount of the virus was reduced by nearly seventy-five percent in three of the four people．But the numbers returned to earlier levels when the treatment ended．

　　Valproic acid has some serious dangers, especially for women who will soon give birth．Doctor Margolis says more study is needed into its use against AIDS．But the scientists do say that their early finding suggests that new methods will produce a cure of HIV in the future．Some other scientists, however, say it is too early to talk of cure for a virus that is so difficult to destroy．They say a cure would have to make the patients healthy again and the virus might not hide only in the protection system．

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