Blood-thinner: A common name for an anticoagulant agent used to prevent the formation of blood clots. Blood-thinners do not really thin the blood. They prevent it from clotting.
Blood-thinners (anticoagulants) have various uses. Some are used for the prophylaxis (prevention) of thromboembolic disorders; others are used for the treatment of thromboembolism. (Thrombi are clots. Emboli are clots that break free, travel through the bloodstream, and lodge in a vessel.) The anticoagulant drugs used for these clinical purposes include:
Intravenous heparin — which acts by inactivating thrombin and several other clotting factors required for a clot to form;
Oral anticoagulants such as warfarin and dicumarol — which act by inhibiting the liver’s production of vitamin K dependent factors crucial to clotting.
Anticoagulant solutions are also used for the preservation of stored whole blood and blood fractions. These anticoagulants include heparin and acid citrate dextrose (commonly called ACD).
Anticoagulants are also used to keep laboratory blood specimens from clotting. These agents include not only heparin but also several agents that make calcium ions unavailable to the clotting process and so prevent the formation of clots; these agents include ethylenediaminetetraacetic acid (commonly called EDTA), citrate, oxalate and fluoride.
- Bloody nose
Bloody nose: Bleeding from the blood vessels of the nose. The nose is rich in blood vessels and is situated in a vulnerable position on the face. As a result, any trauma to the face can cause bleeding, which may be profuse. Nosebleeds can also occur spontaneously when the nasal membranes dry out, crust, and […]
- Bloody show
Bloody show: Literally, the appearance of blood, a classic sign of impending labor. The bloody show ‘consists of blood-tinged mucus created by extrusion and passage of the mucous plug that filled the cervical canal during pregnancy.
- Bloody sputum
Bloody sputum: Coughed up blood or bloody mucus. Bloody sputum can be caused by infection in the lungs and airways, such as acute bronchitis or pneumonia, or cancer. Whenever bloody sputum is present and cannot be attributed to a curable infectious condition, a complete lung evaluation is warranted, including bronchoscopy, to be certain cancer is […]
- Blot, Northern
Blot, Northern: A technique in molecular biology, used mainly to separate and identify pieces of RNA. Called a Northern blot only because it is similar to a Southern blot (which is named after its inventor, the British biologist M.E. Southern). There is also a Western blot.
- Blot, Southern
Blot, Southern: A test commonly used in molecular biology and genetics, the purpose of the test being to check for a match between DNA molecules. In the Southern blot technique, DNA fragments are separated by a method called agarose gel electrophoresis, transferred (blotted) onto membrane filters, and hybridized with complementary radiolabeled probes. The aim is […]