Glossary of Medical Terms

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Cyanocobalamin helps make red blood cells, DNA, RNA, energy, and tissues, and keeps nerve cells healthy. It is found in liver, meat, eggs, poultry, shellfish, milk, and milk products. Cyanocobalamin is water-soluble (can dissolve in water) and must be taken in every day. Not enough cyanocobalamin can cause certain types of anemia (a condition in which the number of red blood cells is below normal) and neurologic disorders. It is being studied with folate in the prevention and treatment of some types of cancer. Also called cobalamin and vitamin B12.

A plant compound that contains sugar and produces cyanide.

Blue-colored skin caused by too little oxygen in the blood.

A substance being studied in the treatment of some types of cancer. It blocks certain enzymes involved in cell division and may kill cancer cells. It may also prevent the growth of new blood vessels that tumors need to grow. It is a type of protein kinase inhibitor and a type of antiangiogenesis agent.

A period of treatment followed by a period of rest (no treatment) that is repeated on a regular schedule. For example, treatment given for one week followed by three weeks of rest is one cycle of treatment. When this cycle is repeated multiple times on a regular schedule, it makes up a course of treatment. Also called treatment cycle.

A chronic condition that affects neutrophils (a type of white blood cell). In cyclic neutropenia, the number of neutrophils in the blood goes in cycles from normal to low and back to normal again. Symptoms include fever, inflamed mucous membranes in the mouth, and infections. Also called periodic neutropenia.

A protein that helps control cell division. It is found in higher than normal amounts in several types of cancer cells. Measuring the amount of cyclin-D1 in blood cells may help to diagnose cancer or plan cancer treatment. Cyclin-D1 is a cell cycle protein and a type of tumor marker.

COX inhibitor. A type of drug that is used to treat inflammation and pain, and is being studied in the prevention and treatment of cancer. Cyclo-oxygenase inhibitors belong to the family of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). Also called COX inhibitor.

An enzyme that speeds up the formation of substances that cause inflammation and pain. It may also cause tumor cells to grow. Some tumors have high levels of cyclooxygenase-2 and blocking its activity may reduce tumor growth. Also called COX-2 and prostaglandin-endoperoxide synthase 2.

A nonsteroidal anti-inflammatory drug used to relieve pain and inflammation. Cyclooxygenase-2 inhibitors are being studied in the prevention of colon polyps, and as anticancer drugs. Also called COX-2 inhibitor.