HIV strains that preferentially infect macrophages in cell culture experiments. They readily fuse with cells that have both CD4 and CCR5 molecules on their surfaces, whereas the same viral isolates fail to fuse with cells expressing only CD4. These isolates are the main strains found in patients during the symptom-free stage of HIV disease.

A non-invasive, non-x-ray diagnostic technique that provides computer-generated images of the body's internal tissues and organs.

Also referred to as secondary prophylaxis. A therapy that prevents reoccurrence of an infection that has been brought under control.

Decreased intestinal absorption resulting in loss of appetite, muscle pain, and weight loss.

A generalized, nonspecific feeling of discomfort.

Removal of the foreskin of the penis. Studies have shown that this can significantly reduce the risk of HIV and other STIs.

Refers to cells or tumours growing in an uncontrolled fashion. Such growths may spread to and disrupt nearby normal tissue, or reach distant sites via the bloodstream. By definition, cancers are always malignant, and the term "malignancy" implies cancer.

A granulocyte found in tissue. The contents of the mast cells, along with those of basophils, are responsible for the symptoms of allergy.

A subset of T lymphocytes that have been exposed to specific antigens and can then proliferate (i.e., reproduce) on subsequent immune system encounters with the same antigen.

Membranes surrounding the brain or spinal cord. Part of the so-called "blood-brain barrier."

An inflammation of the meninges (membranes surrounding the brain or spinal cord), which may be caused by a bacterium, fungus, or virus.

The chemical changes in living cells by which energy is provided for vital processes and activities and new material is assimilated.

The spread of a disease (e.g., cancer) from an original site to other sites in the body.

Microscopic living organisms, including bacteria, protozoa, viruses, and fungi.

An agent (e.g., a chemical or antibiotic) that destroys microbes. Research is being carried out to evaluate the use of rectal and vaginal microbicides to inhibit the transmission of sexually transmitted infections, including HIV.

A cream that a woman can apply intravaginally in order to reduce her risk of sexually transmitted infection. No microbicide product has yet been shown to be effective in reducing susceptibility to HIV, but roughly 20 products are currently being tested in clinical trials.

The smallest particle of a compound that has all the chemical properties of that compound. Molecules are made up of two or more atoms, either of the same element or of two or more different elements.

A disease of the skin and mucous membranes caused by a poxvirus (molluscum contagiosum virus, MCV) infection. It is characterized by pearly white or flesh-colored papules (bumps) on the face, neck, and genital region. In persons living with HIV, molluscum contagiosum is often a progressive disease, resistant to treatment. When CD4+ cells fall below 200, the lesions tend to proliferate and spread.

A large white blood cell that ingests microbes or other cells and foreign particles. When a monocyte enters tissues, it develops into a macrophage.

The condition of being diseased or sick; also the incidence of disease or rate of sickness.

Anything that concerns or pertains to mucous membranes and the skin (e.g., mouth, eyes, vagina, lips, or anal area).

Moist layer of tissue lining the digestive, respiratory, urinary, and reproductive tracts-all the body cavities with openings to the outside world except the ears.

Resistance to infection across the mucous membranes. Dependent on immune cells and antibodies present in the lining of the urogenital tract, gastrointestinal tract, and other parts of the body exposed to the outside world.

Moist layer of tissue lining the digestive, respiratory, urinary, and reproductive tracts-all the body cavities with openings to the outside world except the ears.

A strain of TB that does not respond to two or more standard anti-TB drugs. MDR-TB usually occurs when treatment is interrupted, thus allowing organisms in which mutations for drug resistance have occurred to proliferate.

Also referred to as multi-drug rescue therapy. Salvage or rescue regimens containing 6 or more antiretroviral drugs for patients who have had previous treatment. The hypothesis is that patients with multiple drugs exposure and failures are unlikely to be infected with virus that is resistant to all drugs in the rescue regimen.

During the course of HIV disease, mutated HIV strains may emerge in an infected individual. These mutated strains may differ widely in their ability to infect and kill different cell types, as well as in their rate of replication. Of course, HIV does not mutate into another type of virus.

Diffuse muscle pain or tenderness, usually accompanied by malaise (vague feeling of discomfort or weakness).

Diffuse muscle pain or tenderness, usually accompanied by malaise (vague feeling of discomfort or weakness).

Diffuse muscle pain or tenderness, usually accompanied by malaise (vague feeling of discomfort or weakness).

Any bacterium of the genus Mycobacterium or a closely related genus.

1. A common opportunistic infection caused by two very similar mycobacterial organisms, Mycobacterium avium and Mycobacterium intracellular (MAI), found in soil and dust particles.
2. A bacterial infection that can be localized (limited to a specific organ or area of the body) or disseminated throughout the body. It is a life-threatening disease, although new therapies offer promise for both prevention and treatment. MAC disease is extremely rare in persons who are not infected with HIV. It generally occurs when the CD4+ T cell count falls below 50.

Any disease caused by a fungus.

A substance that sheathes nerve cells, acting as an electric insulator that facilitates the conduction of nerve impulses.

Any disease of the spinal cord.

Suppression of bone marrow activity, causing decreased production of red blood cells (anemia), white blood cells (leukopenia), or platelets (thrombocytopenia). Myelosuppression is a side effect of some drugs, such as AZT.

Destructive to bone marrow.

Refers to the heart's muscle mass.

Progressive muscle weakness. Myopathy may arise as a toxic reaction to AZT or as a consequence of the HIV infection itself.