Human Immune Deficiency Virus

Genetic material. Viruses carry genetic material in the form of single-stranded (ss) or double-stranded (ds) linear or circular RNA or DNA. The genetic material of virus specifies virus proteins. These proteins may be structural pro- 

As it is the outer surface of the virus particle, whether nucleocapsid or envelope, that first makes contact with the membrane of the host cell, its structure and properties are of vital importance in understanding the process of infection. In general, naked (envelope-free) viruses are resistant and survive well in the outside world they may also be bile-resistant, allowing infection through the alimentary canal. Enveloped viruses are more susceptible to environmental factors such as drying, gastric acidity, and bile. These differences in susceptibility influence the ways in which these viruses can be transmitted. 

Viruses, like all pathogens, show host specificity, usually infecting only one or a restricted range of host species. The initial basis of specificity is the ability of the virus particle to attach to the host cell. If the amount of infectious virus is measured over a period of time in the host, it is seen to fall, after an initial lag period, remain low for a period of time, and then rise to even higher levels. The period during which the amount of virus is low is referred to as the eclipse period. The virus infection cycle can be divided into several events. 

Adsorption (Binding). The process of adsorption by a host cell depends first upon the operation of general intermolecular forces, then upon more specific interactions between the molecules of the nucleocapsid or the virus membrane and the molecules of the host cell membrane. In most cases there has 

Penetration. After fusion of viral and host membranes, or uptake into a phagosome, the virus particle is carried into the cytoplasm across the plasma membrane. This penetration process is an active one that requires expenditure of energy by the cell. At this stage the envelope and the capsid are shed, and the viral nucleic acids are released. The uncoating of virus accounts for the drop in infectious virus assayed, because the uncoated virus cannot withstand the assay conditions. 

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The virus that causes AIDS, the Human Immune Deficiency Virus (HIV) is a retrovirus. Instead of double-stranded DNA it uses single-stranded RNA to store its genetic information. HIV uses the enzyme reverse transcriptase to convert its RNA into DNA in order to replicate. 

An example of the rational approach to drug design is provided by the development of HIV (human immune deficiency virus) protease inhibitors. HIV protease cleaves viral polyproteins - the initial products of translation - into the individual protein components and thus is essential for... 

This enzyme hydrolyses proteins and plays an important role in the replication of the human immune deficiency virus. It belongs to the family of aspartic proteases. It catalyses the reaction... 

HIV human immune deficiency virus HPV human papillomavirus HSV herpes simplex virus ICAM intercellular adhesion molecule IL interleukin IL-la interleukin 1 a LNA locked nucleic acid mRNA messenger RNA NK natural killer PKC protein kinase C ply rC poly ribocytosine PNA peptide nucleic acid poly rl poly ribinosine PTHrP parathyroid hormone-related peptide thermal melting temperature change in relative to DNA TAR transactivator response element VSV vesicular stomatitis virus... 

Chiba, M. Nishime, J.A. Lin, J.H. Potent and selective inactivation of human liver microsomal cytochrome P-450 isoforms by L-754,394, an investigationed human immune deficiency virus protease inhibitor. J.Pharmacol.Exp.Ther., 1995, 275, 1527—1534... 

Agents which are potentially hazardous when personnel are contaminated by a fraction of the vial contents. This category includes radiochemicals, self-replicating pathogens and untreated or untested blood or tissue samples which may be contaminated with hepatitis virus, human immune deficiency virus, etc. 

Wiley CA, MasUah E, Morey M, Lemere C, DeTeresa R, Grafe M, Hansen L, Terry R (1991) Neocorfical damage during HIV infection. Ann Neurol 29(6) 651-657 Wiley CA, Schrier RD, Nelson JA, Lampert PW, Oldstone MB (1986) Cellular localization of human immunodeficiency virus infection within the brains of acquired immune deficiency syndrome patients. Proc Natl Acad Sci USA 83(18) 7089-7093 Williams K, Westmoreland S, Greco J, Ratai E, Lentz M, Kim WK, Fuller RA, Kim JP, Autissier... 

Barohn RJ, Gronseth GS et al (1993) Peripheral nervous system involvement in a large cohort of human immunodeficiency virus-infected individuals. Arch Neurol 50(2) 167-171 Behar R, Wiley C et al (1987) Cytomegalovirus polyradiculoneuropathy in acquired immune deficiency syndrome. Neurology 37(4) 557-561... 

There is much concern for the safety of personnel handling articles contaminated with pathogenic viruses such as hepatitis B virus (HB V) and human immunodeficiency vims (HIV) which causes acquired immune deficiency syndrome (AIDS). Some agents have been recommended for disinfection of HBV and HIV depending on the circumstances and level of contamination these are hsted in Table 10.4. Disinfectants must be able to treat rapidly and reliably accidental spills of blood, body fluids or secretions from HIV infected patients. Such spills may contain levels of HIV as high as lO" infectious units/ml. Recent evidence Irom the Medical Devices Agency evaluation of disinfectants against HIV indicated that few chemicals could destroy the vims in a... 

The human immunodeficiency virus (HIV lymphadenopathy-associated virus, LAV human T-cell lymphotrophic virus type 3, HTLV III) is responsible for acquired immune deficiency syndrome (AIDS see Chapter 3). Because of the hazard and difficulties of growing the virus outside humans, a different approach has to be examined for determining viral sensitivity to disinfectants. 

Document any risk factors for allergic reactions such as chronic urticaria, liver or kidney disease, human immunodeficiency virus, or any other immune deficiencies. 

The acquired immune deficiency syndrome (AIDS) was first recognized in 1981, and described in a cohort of young homosexual men with significant immune deficiency. Since then, human immunodeficiency virus type 1 (HIV-1) has been clearly identified as the major cause of AIDS.1 HIV-2 is much less prevalent than HIV-1, but also causes AIDS. HIV primarily targets CD4+ lymphocytes, which are critical to proper immune system function. If left untreated, patients experience a prolonged asymptomatic period followed by rapid, progressive immunodeficiency. Therefore, most complications experienced by patients with AIDS involve opportunistic infections and cancers. 

AIDS, acquired immune deficiency syndrome HIV, human immunodeficiency virus. (Adapted from the DHHS Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents, April 7, 2005.)... 

Kalyanaraman, D. Mann, G. D. Sidhu, R. E. Stahl, S. Zolla-Prazner, J. Leibowitch, and M. Popovic, Isolation of human T-cell leukemia virus in acquired immune deficiency syndrome (AIDS), Science 220 865 (1983). 

Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome... 

AIDS, acquired immune deficiency syndrome HIV, human immunodeficiency virus PGL, persistent generalized lymphadenopathy. 

Acquired immune deficiency syndrome Human immunodeficiency virus... 

In a biopsy of an AIDS patient s enlarged thymus (P4), the adipose involuted thymus, with persistence of many Hassall s corpuscles, was judged to be a large lymphoid follicular hyperplasia. This follicular hyperplasia was similar to that described for lymph nodes, spleen, and other lymphoid tissues at earlier stages of human immunodeficiency virus infection, before the development of acquired immune deficiency syndrome. Human immunodeficiency virus RNA and p 24 were detected in the hyperplastic germinal centers (lymphocytes and follicular dendritic infected cells) and also in many cells that may have been either lymphocytes or epithelial cells in the interfollicular areas. 

The disease known as acquired immune deficiency S5mdrome (AIDS) was first reported in 1981, and the virus that causes it continues to create formidable challenges to the biomedical research and public health communities around the world. Globally, about 14,000 individuals are newly infected daily with one of the nine known subtypes of human immunodeficiency vims (HIV) that cause AIDS. Cumulatively, as of the year 2004, the vims has infected more than 70 million individuals, killing about 30 million and leaving another 40 million with an infection that is ultimately fatal. More than 90% of these infections have occurred in the developing world, where access to antiretroviral therapy is minimal. 

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