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论文作者:留学生论文论文属性:短文 essay登出时间:2010-06-15编辑:vshellyn点击率:4343
论文字数:论文编号:org201006152005559723语种:英语 English地区:泰国价格:免费论文
The AIDS virus is one of the most deadly and most wide spread diseases in the
modern era. The disease was first found in 1981 as doctors around the United States
began to report groups of young, homosexual men developing a rare pneumonia
caused by an organism called Penumocystis carini. These patients then went on to
develop many other new and rare complications that had previously been seen only in
patients with severely damaged immune systems. The Center for Disease Control in
the United States named this new epidemic the acquired immunodeficiency syndrome
and defined it by a specific set of symptoms. In 1983, researchers finally identified the
virus that caused AIDS. They named the virus the human immunodeficiency virus, or
HIV. AIDS causes the immune system of the infected patient to become much less
efficient until it stops working altogether.
The first drug that was approved by the American Food and Drug
administration for use in treating the AIDS virus is called AZT, which stands for
azido-thymidine. AZT was released under the brand name of Retrovir and it's chemical
name is Zidovudine, or ZDV. The structural name of AZT is 3'-azido-3'-
deoxythymidine. AZT works by inhibiting the process of copying DNA in cells. More
specifically, AZT, inhibits the reverse transcriptase enzyme, which is involved in the
DNA replication process. When DNA is replicating in a cell, there is a specific enzyme
that works along one side of the original DNA strand as the DNA is split into two
strands, copying each individual nucleotide. This enzyme is only able to work in one
direction along the nucleotide string, therefore a different enzyme, or rather a series of
different enzymes is required to work in the opposite direction. Reverse transcriptase
is one of the enzymes that is required to work in the opposite direction. AZT works by
bonding to the reverse transcriptase enzyme, thereby making it unable to bond with
the nucleotide string and making it unable to fulfill it's role. This whole process is used
by the HIV virus to replicate itself so that it can continue to infect more cells.
AZT was originally developed over 20 years ago for the treatment of lukemia.
The concept behind this was that the AZT was supposed to terminate the DNA
synthesis in the growing lukemia lymphocytes, thereby stopping the disease. AZT was
rejected at this point because it failed to lengthen the lives of test animals.
The problem with the AZT drug is that it is not perfect. First of all, AZT will
not bond to each and every reverse transcriptase enzyme in the body, and therefore it
cannot shut down the HIV production completely. The reason for this is because to
put enough AZT in the patient to completely shut down the HIV production would
probably kill the patient. The second, and most serious problem with AZT is that it
also goes into normal, healthy cells and will inhibit their reverse transcriptase enzyme
and will therefore inhibit their ability to produce new, healthy cells. However, AZT
does have an ability to specifically target HIV infected cells to a certain degree so that
it does not kill each and every cell i本论文由英语论文网提供整理,提供论文代写,英语论文代写,代写论文,代写英语论文,代写留学生论文,代写英文论文,留学生论文代写相关核心关键词搜索。