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AIDS Essay, Research Paper

AIDS

AIDS (acquired immunodeficiency syndrome) is a disease caused by a

virus- HIV (human immunodiciency virus). The first cases in this country came to

light in the early eighties. Although the origins of AIDS remains uncertain it

is thought to have emerged decades ago in sub-Saharan Africa. There is a

closely related virus (simian immunodeficiency virus, or SIV) that is found

among monkeys in that particular area which AIDS is thought to have evolved from

(Combating AIDS 353). When the virus first emerged in the United States it was

localized to the male homosexual and IV drug user communities. This

localization very quickly disappeared .

AIDS is becoming a global epidemic. No country is safe from it. There

has been AIDS cases reported around the world, in such places as the Caribbean,

Southeast Asia, Southeast Mediterranean , and Oceania. This helps to show that

AIDS knows no geographical boundries (Folks). This disease has been likened to

the Black Plaque that decimated Europe during the middle ages. By April 1984,

scientists had identified the virus responsible for AIDS and by March 1995

developed a blood test for it (Combating AIDS 355). This quick progress in the

battle even lead Heckler, the secretary of health and human services, to say

that a cure was just a few years away. Today, no cure is available and no sure

treatment for AIDS symptoms is at hand. People are still contracting and dying

from AIDS at an alarming rate. AIDS is a fatal disease that does not kill the

patient. Its principle source of infection is the HIV virus which is a

retrovirus. This means that the protein coat contains RNA instead of DNA and

when the virus injects its genetic material into the host cell, it must first

cause the cell to transcribe, using a unique enzyme called reverse transcriptase,

it into complementary- DNA (c-DNA) before replication can occur. The virus is

spherical in shape and is made of two parts: an envelop and core. The envelop

is similar to a typical cell membrane (bilipid layer) imbedded with three

proteins. The core section is bullet-shaped surrounded by a protein. Inside is

the genetic material, RNA, covered by another protein (Combating AIDS 354). The

HIV virus attacks the human helper T-cell or CD4-lymphocyte (part of the human

immune defense system). This cell normally attacks and destroys foreign

proteins and viruses. The normal CD4 T-lymphocyte is impervious to the HIV

virus but if this cell produces a CD4 receptor molecule the HIV virus then has

an entry into the cell. It attaches to the CD4 receptors on the cell surface.

A portion of the virus then penetrates the cell membrane, fuses with it and then

the HIV virus injects its core into the cell. Proteins in the core cause the

receptor cell to manufacture the viral c-DNA. This c-DNA then becomes a part of

the cells genetic material. When this happens what is known as a provirus is

formed. This provirus can remain unexpressed for years which is why a lot of

HIV positive people do not show AIDS symptoms for years. When some activator

stimulates the provirus, then viral RNA and the HIV proteins are synthesized and

new HIV viruses are produced (Nowak 964).

When activated, the virus causes a suppression of the immune system so

that one or more “opportunistic” diseases can gain a foothold. It is one of

these diseases which eventually kills the patient. An “opportunistic ” disease

is one which a normal person’s immune system can successfully defend against.

When something occurs that damages the immune system, then these diseases abound

(Folks).

One of the symptoms of full blown AIDS is dementia. This was thought to

be caused by encephalitis (inflammation of the brain). New evidence suggests

that the AIDS virus itself destroys neurons in the brain even though it does

not infect them. In laboratory findings the level of neurons in the brains of

dead AIDS patients was forty percent less than in non AIDS brains. The brains

of dead AIDS patients showed signs of HIV but the majority did not show signs of

encephalitis. It is proposed that the protein coat on HIV may interfere with

VIP (a brain protein) which some neurons need in order to send signals (Walker

311).

There are many areas of research in determining what causes the

activation of HIV. New evidence supports the theory that there is a cofactor

involved with the accelerated onset of AIDS. This cofactor is thought to be a

mycoplasma-a primitive bacteria. The effect seems to be indirect. The

mycoplasma seems to stimulate the cell to produce substances called cytokine.

Certain cytokines are immune system simulators that are known to activate HIV.

To test the theory, scientist conducted an experiment in which human CD4

lymphocytes were infected with a mycoplasma, or HIV alone began dying off but

eventually recovered. The cells with both died off but did not recover. This

seems to indicate that something about the mycoplasma infection promotes the

growth of HIV (Ezzell 133).

Another suspected cofactor is Herpesvirus-6. This is a virus that is

normally carried by most people. It infects CD4 cells and causes them to

produce the CD4 receptor molecule. The CD4 cell, normally a killer cell is

itself destroyed by the herpesvirus-6. In those cells not destroyed, the

herpesvirus-6 may actually work in

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