Streptokinase Health Dictionary

A protein that acts as a catalyst for the body’s metabolic processes. The body contains thousands of enzymes, with each cell producing several varieties. The ?rst enzyme was obtained in a reasonably pure state in 1926. Since then, several hundred enzymes have been obtained in pure crystalline form. They are present in the digestive ?uids and in many of the tissues, and are capable of producing in small amounts the transformation on a large scale of various compounds. Examples of enzymes are found in the PTYALIN of saliva and DIASTASE of pancreatic juice which split up starch into sugar; the PEPSIN of the gastric juice and the trypsin of pancreatic juice which break proteins into simpler molecules and eventually into the constituent amino acids; and the thrombin of the blood which causes coagulation.

The diagnosis of certain disorders can be helped by measuring the concentrations of various enzymes in the blood. After a heart attack (myocardial infarction – see HEART, DISEASES OF), raised levels of heart enzymes occur as a result of damage to the cells of the heart muscle. Some inherited diseases such as GALACTOSAEMIA and PHENYLKETONURIA are the result of de?ciencies of certain enzymes.

Enzymes can be a useful part of treatment for some disorders. STREPTOKINASE, for example, is used to treat THROMBOSIS; wound-dressings containing papain from the pawpaw fruit – this contains protein-digesting enzymes – assist in the healing process; and pancreatic enzymes can be of value to patients with malabsorption caused by disorders of the PANCREAS.... enzyme

A group of drugs, also known as thrombolytics, with the ability to break down the protein FIBRIN, the prime constituent of blood clots (see THROMBUS; THROMBOSIS). They are used to disperse blood clots that have formed in the vessels of the circulatory system. The group includes STREPTOKINASE, alteplase and reteplase. The drugs work by activating PLASMINOGEN to form PLASMIN which degrades ?brin and breaks up the blood clot (see COAGULATION).... fibrinolytic drugs

The formation of a thrombus (BLOOD CLOT) in one part of the circulatory system from which a portion becomes detached and lodges in another blood vessel, partially or completely obstructing the blood ?ow (an EMBOLISM). Most commonly a thrombus is formed in the veins of the leg – DEEP VEIN THROMBOSIS (DVT)

– and the embolism lodges in the pulmonary (lung) circulation. PULMONARY EMBOLISM is a potentially fatal condition and requires urgent anticoagulant treatment (see ANTICOAGULANTS) and sometimes surgery. Extended periods lying in bed or prolonged sitting in a con?ned position such as a car or aeroplane can cause DVT; venous thromboses in the legs may occur after surgery and preventive anticoagulant treatment with HEPARIN and warfarin is often used. Similar treatment is needed if a thrombus develops. STREPTOKINASE is also used to treat thromboembolism.... thromboembolism

The breakdown of a BLOOD CLOT by enzymic activity (see ENZYME). Naturally occurring enzymes limit the enlargement of clots, and drugs – for example, STREPTOKINASE – may be given to ‘dissolve’ clots (e.g. following a coronary THROMBOSIS – see under HEART, DISEASES OF). The drug needs to be given within 6–12 hours to be e?ective in reducing the death rate, so prompt diagnosis and transfer to hospital is essential: a short ‘door-to-needle’ time. An unwanted e?ect may be increased risk of bleeding, especially in the elderly. It has been used in trials in patients with PULMONARY EMBOLISM and with peripheral arterial disease, but its value in these conditions is uncertain.... thrombolysis

adj. describing a group of drugs that are capable of breaking down the protein fibrin (see fibrinolysis), which is the main constituent of blood clots, and are therefore used to disperse blood clots (thrombi) that have formed within the circulation, most notably after myocardial infarction. They include *streptokinase, *urokinase, *alteplase, reteplase, and tenecteplase. Possible side-effects include bleeding at needle puncture sites, headache, backache, blood spots in the skin, and allergic reactions.... fibrinolytic

obstruction of the *pulmonary artery or one of its branches by an *embolus, usually a blood clot derived from *phlebothrombosis of the leg veins (deep vein thrombosis). Large pulmonary emboli result in acute heart failure or sudden death. Smaller emboli cause death of sections of lung tissue, pleurisy, and haemoptysis (coughing of blood). Minor pulmonary emboli respond to the *anticoagulant drugs heparin and warfarin. Major pulmonary embolism is treated by *embolectomy or by dissolution of the blood clot with an infusion of *streptokinase. Recurrent pulmonary embolism may result in *pulmonary hypertension.... pulmonary embolism

n. an enzyme produced by some haemolytic bacteria of the genus Streptococcus that is capable of liquefying pus. See also streptokinase.... streptodornase

(tPA, TPA) a natural protein, found in the body and able to be manufactured by genetic engineering, that can break up a thrombus (see thrombolysis). It requires the presence of *fibrin as a cofactor and is able to activate *plasminogen on the fibrin surface, which distinguishes it from the other plasminogen activators, *streptokinase and *urokinase. tPAs include reteplase and tenecteplase, given to treat acute myocardial infarction, and *alteplase.... tissue-type plasminogen activator

n. a genus of Gram-positive nonmotile spherical bacteria occurring in chains. Most species are saprophytes; some are pathogenic. Many pathogenic species are haemolytic, i.e. they have the ability to destroy red blood cells in blood agar. This provides a useful basis for classifying the many different strains. Strains of S. pyogenes (the ?-haemolytic streptococci) are associated with many infections, including *scarlet fever, and produce many *exotoxins. Strains of the ?-haemolytic streptococci are associated with bacterial *endocarditis. The species S. pneumoniae (formerly Diplococcus pneumoniae) – the pneumococcus – is associated with serious diseases, including pneumonia, pneumococcal *meningitis, and septicaemia; it is also a common bacterial cause of ear infections (see also pneumococcal vaccine). It occurs in pairs, surrounded by a capsule (see quellung reaction). S. mutans has been shown to cause dental caries. See also Lancefield classification; streptokinase. —streptococcal adj.... streptococcus