Unit 2 Section A.doc

Section A AIDS, Recent Advances in Research and Treatment艾滋病在研究和治疗方面的新进展History艾滋病的历史Acquired Immune Deficiency Syndrome (AIDS) was first clinically observed in 1981 in the United States. The initial cases were a cluster of injecting drug users and homosexual men with no known cause of impaired immunity who showed symptoms of Pneumocystis carinii pneumonia (PCP), a rare opportunistic infection that was known to occur in people with very compromised immune systems. Soon thereafter, an unexpected number of gay men developed a previously rare skin cancer called Kaposi's sarcoma (KS). Many more cases of PCP and KS emerged, alerting U.S. Centers for Disease Control and Prevention (CDC) and a CDC task force was formed to monitor the outbreak. 1981年，美国确诊了第一例获得性免疫缺陷综合征（即艾滋病）。

最初的病例是一群不知什么原因免疫力受损的注射吸毒者和男同性恋者，他们表现出卡氏肺孢子虫肺炎的症状，据称这是一种发生在免疫系统严重受损人群中的罕见的机会性感染此后不久，许多男同性恋者出乎意料地得了一种以前很少见的叫卡波济肉瘤的皮肤癌后来出现了更多的卡氏肺孢子虫肺炎和卡波济肉瘤病例，给美国疾病控制与预防中心（CDC）发出了警报，于是，成立了一个特别小组去监测艾滋病的爆发In the early days, the CDC did not have an official name for the disease, often referring to it by way of the diseases that were associated with it, for example, lymphadenopathy, the disease after which the discoverers of HIV originally named the virus. They also used Kaposi's Sarcoma and Opportunistic Infections, the name by which a task force had been set up in 1981. At one point, the CDC coined the phrase “the 4H disease”, since the syndrome seemed to affect Haitians, homosexuals, hemophiliacs, and heroin users. In the general press, the term "GRID", which stood for gay-related immune deficiency, had been coined. However, after determining that AIDS was not isolated to the gay community, it was realized that the term GRID was misleading and the term AIDS was introduced at a meeting in July 1982. By September 1982 the CDC started referring to the disease as AIDS. 在早期，美国疾病控制与预防中心对这种疾病并没有一个官方的名字，谈及这种疾病时通常用与之相关的疾病代替，比如：淋巴结病，人体免疫缺陷病毒的发现者最初就是以这种疾病给该病毒命名的。

他们同样也使用过卡波济肉瘤和机会性感染，1981年一个特别小组成立时就是用的这个名称美国疾病控制与预防中心曾经创造过一个短语——“4H疾病”，因为这种综合征似乎更易感染这四种人——海地人，同性恋者，血友病患者和吸食毒品者在普通报刊中，创造了一个术语“GRID”，表示与同性恋有关的免疫缺陷然而，在人们确定AIDS并非仅存在于同性恋群体中后，认识到“GRID” 这个术语容易引起误解于是，在1982年7月召开的一次会议上首次引入AIDS这个术语到1982年9月，美国疾病控制与预防中心开始把这种疾病称作艾滋病（AIDS）In 1983, two separate research groups led by Robert Gallo and Luc Montagnier independently declared that a novel retrovirus may have been infecting AIDS patients, and published their findings in the same issue of the journal Science. Gallo claimed that a virus his group had isolated from an AIDS patient was strikingly similar in shape to other human T-lymphotropic viruses (HTLVs) his group had been the first to isolate. Gallo’s group called their newly isolated virus HTLV-III. At the same time, Montagnier’s group isolated a virus from a patient presenting with swelling of the lymph nodes of the neck and physical weakness, two characteristic symptoms of AIDS. Contradicting the report from Gallo’s group, Montagnier and his colleagues showed that core proteins of this virus were immunologically different from those of HTLV-I. Montagnier's group named their isolated virus lymphadenopathy-associated virus (LAV). As these two viruses turned out to be the same, in 1986, LAV and HTLV-III were renamed HIV. Since that time, the number of people infected with the causative virus of the syndrome and of those who die from the various consequences of the infection, has grown considerably.1983年，由罗伯特·加洛和吕克·蒙塔尼耶领导的两个独立的研究小组宣称一种新的逆转录病毒可能感染艾滋病患者，并将他们的研究结果发表在同一期的《科学》杂志上。

加洛称，他的研究小组从艾滋病患者体内分离出一种病毒，与他们在世界上首度分离出的那些其他人类T淋巴细胞病毒（HTLV）在形状上惊人地相似加洛研究小组将这一新分离的病毒称为HTLV-III型病毒与此同时，蒙塔尼耶研究小组从一个身体虚弱，颈部淋巴结肿胀（艾滋病的两大典型症状）的患者体内分离出一种病毒与加洛研究小组的报告相反的是，蒙塔尼耶和他的同事指出这种病毒的核心蛋白在免疫学上不同于HTLV-I型蒙塔尼耶研究小组把他们分离出来的病毒命名为淋巴腺病相关病毒（LAV）由于这两种病毒实际上属于同一种病毒，于是，1986年LAV病毒和HTLV-III型病毒被重新命名为HIV病毒从那以后，感染艾滋病致病病毒和死于这种感染各种各样后果的人数大幅增加Research on AIDS艾滋病方面的研究In the 1980s and 1990s, researchers were able to establish that the principal target for the maladies associated with AIDS is the immune system. Since then, much research has been directed towards pinpointing the changes in the human immune system due to infection, seeking ways of reversing these changes, or supplementing the compromised immune system to hold the infection in check.二十世纪八、九十年代，研究人员证实，艾滋病相关疾病的主要攻击目标是免疫系统。

自那时起，许多研究开始转向探究感染前后人类免疫系统的变化情况，寻求扭转这些变化的方法，或增强受损免疫系统的免疫力使之能够抑制这种感染The particular immune system component that has been implicated in the progression of AIDS is a type of T cell called the CD4 T cell. This cell, which is activated following recognition of the virus by the immune system, functions in the destruction of the cells that have been infected by the virus. Over time, however, the number of CD4 cells declines. If the decline decreases the T cell count to below 200 per microliter of blood, the number of infective virus particles goes up steeply and the immune system breaks down. This loss of the ability to fight off foreign organisms leaves the patient open to life-threatening illnesses that normally would be rou。