Protein C is a protein in plasma that enters into the cascade of biochemical events leading to the formation of a clot. Deficiency of protein C results in thrombotic (clotting) disease and excess platelets with recurrent thrombophlebitis (inflammation of the vein that occurs when a clot forms). The clot can break loose and travel through the blood stream (thromboembolism) to the lungs causing a pulmonary embolism, brain causing a stroke (cerebrovascular accident), heart causing an early heart attack, skin causing what in the newborn is called neonatal purpura fulminans, the adrenal gland causing hemorrhage with abdominal pain, abnormally low blood pressure (hypotension), and salt loss. Protein C deficiency is due to possession of one gene (heterozygosity) in chromosome band 2q13-14. The possession of two such genes (homozygosity) is usually lethal.
- Thrombotic thrombocytopenic purpura (TTP)
A life-threatening disease involving embolism and thrombosis (plugging) of the small blood vessels in the brain and kidneys and other organs. It is most commonly caused by inhibition of the enzymes ADAMTS13 which normally serves to break up a blood protein called Von Willebrand Factor into smaller pieces. TTP is characterized by platelet microthrombi (tiny […]
A substance made by platelets that causes blood clotting and constriction of blood vessels. It also encourages platelet aggregation. There are two thromboxanes. Thromboxane A2 (TXA2) is active but is very unstable and has a half-life of only 30 seconds before it undergoes hydrolysis to form thromboxane B2 (TXB2) which is inactive. The thromboxanes are […]
- Thromboxane A2
The active type of thromboxane. Abbreviated TXA2.
- Thromboxane B2
The inactive product of thromboxane. Abbreviated TXB2
A clot in a blood vessel or within the heart.