艾滋病英語作文:艾滋病未解之謎2000字
In the 20years since the first cases of AIDS were detected, scientists say they have learned more about this viral disease than any other.
Yet Peter Piot, who directs the United Nations AIDS program, and Stefano Vella of Rome, president of the International AIDS Society, and other experts say reviewing unanswered questions could prove useful as a measure of progress for AIDS and other diseases.
Among the important broader scientific questions that remain:
Why does AIDS predispose infected persons to certain types of cancer and infections?
A long-standing belief is that cancer cells constantly develop and are held in check by a healthy immune system. But AIDS has challenged that belief. People with AIDS are much more prone to certain cancers like non-Hodgkins lymphomas and Kaposi’s sarcoma , but not to breast, colon and lung, the most common cancers in the United States. This pattern suggests that an impaired immune system, at least the type that occurs in AIDS, does not allow common cancers to develop.
What route does HIV take after it enters the body to destroy the immune system?
When HIV is transmitted sexually, the virus must cross a tissue barrier to enter the body. How that happens is still unclear. The virus might invade directly or be carried by a series of different kinds of cells.
Eventually HIV travels through lymph vessels to lymph nodes and the rest of the lymph system. But what is not known is how the virus proceeds to destroy the body’s CD-4cells that are needed to combat invading infectious agents.
How does HIV subvert the immune sys-tem?
Although HIV kills the immune cells sent to kill the virus, there is widespread variation in the rate at which HIV infected people become ill with AIDS. So scientists ask:Can the elements of the immune system responsible for that variability be identified?If so, can they be used to stop progression to AIDS in infected individuals and possibly prevent infection in the first place?
What is the most effective anti-HIV therapy?
In theory, early treatment should offer the best chance of preserving immune function. But the new drugs do not completely eliminate HIV from the body so the medicines, which can have dangerous side effects, will have to be taken for a lifetime and perhaps changed to combat resistance. The new policy is expected to recommend that treatment be deferred until there are signs the immune system is weakening.
Is a vaccine possible?
There is little question that an effective vaccine is crucial to controlling the epidemic . Yet only one has reached the stage of full testing, and there is wide controversy over the degree of protection it will provide. HIV strains that are transmitted in various areas of the world differ genetically. It is not known whether a vaccine derived from one type of HIV will confer protection against other types.
In the absence of a vaccine, how can HIV be stopped?
Without more incisive , focused behavioral research, prevention messages alone will not stop the global epidemic.
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預防艾滋病作文:預防艾滋病 你我同參與700字
近年來,我們對艾滋病這個詞可以説是即熟悉又陌生,熟悉是因為我們聽到這個詞的名字太多了,陌生是因為我們對艾滋病的瞭解和認識極少。艾滋病是什麼,説實話我並不太瞭解,但是我知道艾滋病並不像傳聞中的那樣可怕,這幾天和同學們在一起研讀了一些關於艾滋病方面的內容,使...
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艾滋病作文:與艾滋病的大戰作文600字
今天在家閒着沒事做,不知是胡思亂想還是怎麼,我怎麼突然想到了艾滋病,然後就不知覺地睡着了。我做了這樣一個夢,我居然成了一個人體內的淋巴細胞,這個人得了艾滋病,艾滋病菌可是專門破壞人體的淋巴細胞!啊,我這個夢怎麼這麼慘,突然,一個淋巴對我説:艾滋病菌正在向我們這兒...
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撐起愛心的大傘——為艾滋病人遮風擋雨1000字
無情的歲月風蝕了阿嫂所有繽飛的夢想,踏上無邊的人生道路,他經歷了艱難困苦,本想給兒子娶個漂亮媳婦。然而,一個災難性的意外不幸發生在她身上。前天,醫生説他的血液裏有艾滋病毒抗體。當時,她的兒子驚呆了,阿嫂眼含着晶瑩般的淚珠囁嚅説了三個子沒什麼。在與猖獗的病...
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預防艾滋病作文:艾滋病——世界之泣1000字
艾滋病,已成了全世界人民共同關心的一個話題。怎樣預防艾滋病,也就成了大家更為關注的話題。大家都知道艾滋病的可怕,都稱它為魔鬼。那麼,艾滋病到底是怎樣的一個魔鬼?通俗的講,艾滋病是人體免疫系統被一種叫做HIV的病毒所破壞,因此身體喪失了抵抗力,不能與那些對生命...