Immunodeficiency syndrome causative agent

Secondary immunodeficiencies (9) are much more common than primary ones and frequently occur as a result of immaturity of the immune system in premature infants, immunosuppressive therapy, or surgery and trauma. Illnesses, particularly when prolonged and serious, have been associated with secondary immunodeficiencies, some of which may be reversible. Acquked immune deficiency syndrome (AIDS) (10—12) may be considered a secondary immunodeficiency disease caused by the human immunodeficiency vimses HIV-1 or HIV-2. Hitherto unknown, the disease began to spread in the United States during the latter part of the 1970s. The agent responsible for this infection has been isolated and identified as a retrovims. 

Viruses are small infectious agents composed of a nucleic acid genome (DNA or RNA) encased by structural proteins and in some cases a lipid envelope. They are the causative agents of a number of human infectious diseases, the most important for public health today being acquired immunodeficiency syndrome (AIDS), hepatitis, influenza, measles, and vituses causing diarrhoea (e.g., rotavirus). In addition, certain viruses contribute to the development of cancer. Antiviral drugs inhibit viral replication by specifically targeting viral enzymes or functions and are used to treat specific virus-associated diseases. 

The human immunodeficiency vims (HIV) is the causative agent of the acquired immunodeficiency syndrome (AIDS). HIV is a retrovirus, whose replication includes the transcription of the single-stranded RNA genome into double stranded DNA (reverse transcription) and the covalent insertion of the DNA... 

Acquired immune deficiency syndrome (AIDS) was initially described in the USA in 1981, although sporadic cases probably occurred for at least two decades prior to this. By 1983, the causative agent, now termed human immunodeficiency virus (HIV), was identified. HIV is a... 

Acquired immunodeficiency syndrome (AIDS), a degenerative disease of the immune and central nervous systems, is responsible for a rapidly growing fatality rate in the world population. Although no cure has been found, research worldwide is aimed at developing strategies for chemotherapy. The causative agent is the human immunodeficiency virus... 

The human immunodeficiency virus (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS), a disease that has claimed the lives of tens of millions of people since the 1980s. Because of the vast impact of AIDS on global health, HIV and its molecular biology have been intensely studied to determine potential drug targets for intervention. 

In 1997, it was estimated that 30 million adults were infected with the human immunodeficiency virus (HIV) worldwide, with increments of five people infected every minute. It is estimated that approximately 7% of the population of sub-Saharan Africa has been infected. The incubation of the disease is 7 to 8 years. Currently available drugs for acquired immunodeficiency syndrome (AIDS) and HIV are zidovudine, didanosine, lamivudine, and stavudine. The causative agent for AIDS is generally an HIV virus, which is transmitted by sexual contact, blood and blood products, the use of contaminated drug needles, and from mother to fetus. 

The most daunting claim to fame for a human retrovirus came in the early 1980s, when teams of researchers in France and the United States jointly identified human immunodeficiency virus (HIV-1) as the etiologic agent in the human acquired immunodeficiency syndrome called AIDS. HIV infection of human T cells eventually results in T-cell death and loss of these important cells from the immune system. AIDS patients with extremely low numbers of T cells are highly susceptible to opportunistic infectious diseases, which are often the underlying cause of death due to AIDS. 

Retroviruses are RNA-DNA viruses that require host-cell genome integration to complete their replication cycle. The retroviral enzyme reverse transcriptase is an RNA-dependent DNA polymerase that has important uses in recombinant DNA methodologies such as the synthesis of complementary DNA (cDNA). The human immunodeficiency virus (HIV) is the etiologic agent that causes acquired immunodeficiency syndrome (AIDS) in humans. HIV infects and destroys human T cells, which are required for immune system functions. 

In order to combat the Human immunodeficiency virus (HIV), the causative agent of the debilitating disease acquired immune deficiency syndrome (AIDS), colossal amount of money, manpower time and energy have been dedicated to research on compounds which can be developed as therapeutic agents. 

A key strategy in the treatment of acquired immunodeficiency syndrome (AIDS) has been to develop specific inhibitors that selectively block the actions of enzymes unique to the human immunodeficiency virus (HIV), which causes AIDS. Many laboratories are working on this approach to the development of therapeutic agents. Three key enzymes are current targets for AIDS therapy—reverse transcriptase, integrase, and protease. 

By the end of 1997, the World Health Organization announced that about thirty million cases of acquired immunodeficiency syndrome (AIDS) have been reported worldwide with approximately an equal number of unreported cases. These numbers are escalating fast. Due to high mortality and morbidity rates of AIDS, special attention has been and still being paid towards the discovery and development of therapeutic agents to either cure the cause or alleviate the symptoms of this syndrome. 

Within 1-3 years after the discovery of human immunodeficiency virus (HIV) as the causative agent of acquired immune deficiency syndrome (AIDS) (1,2), the CD4 molecule was identified as the primary HIV receptor (3). HIV was shown to enter target cells by an initial binding event between the envelope glycoprotein (Env) molecules on the viral membrane and CD4 molecules on the target cell surface, followed by direct, pH-independent membrane fusion. Yet as early as 1986, it became clear that the Env-CD4 interaction was not sufficient to promote the fusion reaction (4-6) several lines of evidence indicated that the target cell must contain an additional human-specific cofactor (7-11), presumably a coreceptor. ... 

The Epstein-Barr virus (EBV) is a B-cell lymphotropic herpesvirus that induces a usually asymptomatic infection and is carried by more than 90% of adults. However, EBV is the causative agent for Burkitt s lymphoma and nasopharyngeal carcinoma and is involved in a number of acquired immunodeficiency syndrome (AIDS)-associated lymphomas. EBV can induce immortalization of B cells in vitro to generate lymphoblastoid cell lines (LCLs), a model for the carcinogenic potential... 

During the early 1980s, a disease called acquired immune deficiency syndrome, commonly known as AIDS, began to claim an alarming number of lives. An HlV-1 virus (human immunodeficiency virus type 1) is now known to be the AIDS-causing agent... 

In 1983 the move to develop red cell substitutes intensified when it was recognized that the acquired immune deficiency syndrome (AIDS) could be transmitted by the blood-bome human immunodeficiency vims (HIV). Concern for the nation s blood supply followed. Since that time other retrovimses have been identified, efforts to screen blood not only for these agents but also for vimses that cause hepatitis have intensified, the indications for transfusion have been reevaluated, and the use of blood products has become much more efficient. More carehil screening of donors, testing of all donated units, and a general awareness in the donor population have all contributed to a decreased risk from transfusion-contracted AIDS. 

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