October 2009

methadone – a man-made opiate that used to treat heroin addiction. See also buprenorphine.

meningitis – inflammation (-itis) of the meninges (part of fluid that surrounds the brain). Meningitis can be caused by different infections – ie bacterial meningitis (from bacterial infection), viral meningitis (form a virus) etc.

Tmax – the time taken for a drug to reach the highest (maximum) concentration. What happens when you take a drug?

T1/2 (half-life) –  the time taken a drug to clear from the highest concentration to half this level. Drugs have different half-lives in different compartments (ie half-life in blood can be different from the half-life inside a cell). It take …

Minimum Effective Concentration (MEC) – the lower level of a drug in the body that will still be effective. What happens when you take a drug?

median (average) – where the results are all arranged in numerical order and the middle of the range is taken as the (median) average. See mean. What is an average.

mean (average) – where all the results are added together, and then divided by the number of results to find the (mean) average. See median. What is an average.

matched – in clinical trials matched refers to each group having similar age, gender, ethnicity, HIV duration, health etc in a study.

malignant – dangerous. A malignant cancer is a dangerous cancer that is growing.

malaria – a parasite infection of red blood cells.

macrophage – large white blood cell that engulfs or ‘eats’ infectious organisms and waste material from dead cells.

lymphoma – name for a cancer in the lymphatic system. Cancer: lymphoma and sarcoma

lymphocyte – medical term for a white (clear) immune cell in blood, lymph or lymph tissue. Two main types of lymphocyte are B cells and T cells. CD4 cells and CD8 cells are both types of T cells. Sometimes a …

lumbar puncture – taking a sample of spinal fluid by inserting a needle into the body at the base of the spine. Also called a spinal tap.

log value – a number expressed as a factor of 10 – ie 2 logs = 10 x 10=100; 3 logs = 10 x 10 x 10=1000. This measurement is used when needing to include very large and very small …

lipodystrophy – body fat changes, including fat loss (from arms, legs, buttocks and face) and/or fat gain (in abdomen, breasts and shoulders). The lipodystrophy syndrome also includes metabolic changes in lipid and glucose metabolism.

lipoatrophy – fat loss in your arms, legs or face. Lipoatrophy is a type of lipodystrophy.

lipid – medical term for fat. The term ‘blood lipids’ refers to cholesterol and triglyceride levels in blood.

lesion – damage to a part of the body.

latent – not active at present, resting. Latently infected CD4 cells are CD4 cells that are infected with HIV but which are resting. HIV drugs do not work on resting cells.