acidification

The process of making or becoming an acid. An acid is a substance that gives off hydrogen ions in water and forms salts by combining with certain metals.

acid-base equilibrium

In medicine, the state of having the right amount of acid and base in the blood and other body fluids. Keeping a normal acid-base equilibrium is important for the body to work the way it should. Also called acid-base balance.

acid-base balance

In medicine, the state of having the right amount of acid and base in the blood and other body fluids. Keeping a normal acid-base balance is important for the body to work the way it should. Also called acid-base equilibrium.

acid

A chemical that gives off hydrogen ions in water and forms salts by combining with certain metals. Acids have a sour taste and turn certain dyes red. Some acids made by the body, such as gastric acid, can help organs work the way they should. An example of an acid is hydrochloric acid. Acidity is measured on a scale called the pH scale. On this scale, a value of 7 is neutral, and a pH value of less than 7 to 0 shows increasing acidity.

achlorhydria

A lack of hydrochloric acid in the digestive juices in the stomach. Hydrochloric acid helps digest food.

ACF

Clusters of abnormal tube-like glands in the lining of the colon and rectum. ACF form before colorectal polyps and are one of the earliest changes that can be seen in the colon that may lead to cancer. Also called aberrant crypt foci.

acetyl-L-carnitine hydrochloride

A form of the natural substance carnitine that is being studied as a way to prevent tissue damage caused by chemotherapy. Carnitine is made in muscle and liver tissue and is found in certain foods, such as meat, poultry, fish, and some dairy products. It is used by many cells in the body to make energy from fat. Also called acetyl-L-carnitine and ALCAR.

acetyl-L-carnitine

A form of the natural substance carnitine that is being studied as a way to prevent tissue damage caused by chemotherapy. Carnitine is made in muscle and liver tissue and is found in certain foods, such as meat, poultry, fish, and some dairy products. It is used by many cells in the body to make energy from fat. Also called acetyl-L-carnitine hydrochloride and ALCAR.

acetylcysteine

A drug usually used to reduce the thickness of mucus and ease its removal. It is also used to reverse the toxicity of high doses of acetaminophen. Also called N-acetyl-L-cysteine and N-acetylcysteine.

acetylcholine

A chemical made by some types of nerve cells. It is used to send messages to other cells, including other nerve cells, muscle cells, and gland cells. It is released from the nerve ending and carries signals to cells on the other side of a synapse (space between nerve cells and other cells). Acetylcholine helps control memory and the action of certain muscles. It is a type of neurotransmitter.

acetylation

A chemical reaction in which a small molecule called an acetyl group is added to other molecules. Acetylation of proteins may affect how they act in the body.

acetyl group

A small molecule made of two carbon, three hydrogen, and one oxygen atoms. Acetyl groups are added to or removed from other molecules and may affect how the molecules act in the body.

acetone

A chemical substance found naturally in small amounts in plants, trees, volcanoes, and forest fires. Acetone is also made by the body when fats are broken down. It is also found in tobacco smoke, car exhaust, and trash landfills. In industry, acetone is used in some plastics, fibers, medicines, household cleaners, glues, and nail polish removers. Being exposed to high levels of acetone may irritate the skin, eyes, nose, throat, and lungs. It can cause headaches, nausea, vomiting, dizziness, confusion, loss of consciousness, and other health problems.

acetic acid

    An acid found in vinegar. Acetic acid is also used to dissolve substances needed to make some medicines and other products, such as plastics.

acetate

A form of acetic acid (an acid found in vinegar).

acetaminophen

A drug that reduces pain and fever (but not inflammation). It belongs to the family of drugs called analgesics.

ACE inhibitor

A drug that is used to lower blood pressure. An ACE inhibitor is a type of antihypertensive agent. Also called angiotensin-converting enzyme inhibitor.

Accolate

A drug used to prevent and treat symptoms of asthma. It blocks substances that cause inflammation in the lungs. It is a type of antiasthmatic agent and a leukotriene receptor antagonist. Also called zafirlukast

accelerated-fraction radiation therapy

Radiation treatment in which the total dose of radiation is divided into small doses and the treatments are given more than once a day. The total dose of radiation is also given over a shorter period of time (fewer days) compared to standard radiation therapy.

accelerated radiation therapy

Radiation treatment in which the total dose of radiation is given over a shorter period of time (fewer days) compared to standard radiation therapy.