Plasm Health Dictionary

The name applied to the straw-coloured ?uid portion of the BLOOD composed of a solution of various inorganic salts of sodium, potassium, calcium, etc., as well as SERUM and ?brinogen, the material which produces clotting (see COAGULATION). When the plasma is clotted, the thinner ?uid separating from the clot is the serum.... plasma

See PLASMA EXCHANGE.... plasmapheresis

These are cells that produce ANTIBODIES and occur in bone-forming tissue as well as the lining of the gastrointestinal tract and the lungs. The cells develop in LYMPH NODES, SPLEEN and BONE MARROW when T-lymphocytes (see IMMUNITY) are stimulated by antigens (see ANTIGEN) to produce the precursor cells from which plasma cells originate.... plasma cells

Also called ?brinolysin, this is an ENZYME that digests the protein FIBRIN. It dissolves blood clots (see COAGULATION) and so is present in the blood in the form of PLASMINOGEN, an inactive precursor.... plasmin

A precursor of PLASMIN, an ENZYME that digests the protein FIBRIN – the main constituent of blood clots (see COAGULATION). When tissue is damaged, activators are released which provoke the conversion of plasminogen into plasmin.... plasminogen

The general term applied to minute protoplasmic cells, and particularly to those which cause MALARIA and allied diseases.... plasmodium

Also known as plasmapheresis. The removal of the circulating PLASMA from the patient. It is done by removing blood from a patient and returning the red cells with a plasma expander. The plasma exchange is carried out through an in-dwelling CANNULA in the femoral vein, and the red cells and plasma are separated by a hemonetics separator. Usually a sequence of three or four sessions is undertaken, at each of which 2–3 litres of plasma are removed. The lost plasma can either be replaced by human serum albumin (see ALBUMINS) or a plasma expander.

In autoimmune disorders, disease is due to damage wrought by circulating ANTIBODIES or sensitised lymphocytes (see LYMPHOCYTE). If the disease is due to circulating humoral antibodies, removal of these antibodies from the body should theoretically relieve the disorder. This is the principle on which plasma exchange was used in the management of autoimmune diseases due to circulating antibodies. Such disorders include Goodpasture’s syndrome, SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) and MYASTHENIA GRAVIS. One of the problems in the use of plasma exchange in the treatment of such diseases is that the body responds to the removal of an antibody from the circulation by enhanced production of that antibody by the immune system. It is therefore necessary to suppress this homeostatic response with cytotoxic drugs such as AZATHIOPRINE. Nevertheless, remissions can be achieved in autoimmune diseases due to circulating antibodies by the process of plasma exchange.... plasma exchange

This procedure is sometimes used instead of blood TRANSFUSION. PLASMA – the ?uid part of blood from which the cells have been separated

– may be dried and in powder form kept almost inde?nitely; when wanted it is reconstituted by adding sterile distilled water. In powder form it can be transported easily and over long distances. Transfusion of plasma is especially useful in the treatment of SHOCK. One advantage of plasma transfusion is that it is not necessary to carry out testing of blood groups before using it.... plasma transfusion

Any self -replicating genetic component of a cell, e.g. bacteria, which is outside the chromosomes.... plasmid

A generic description of any discrete agents in cells that have genetic functions. They include plasmagenes (self-reproducing copies of a nuclear gene existing outside the cell nucleus) and viruses.... plasmids

A natural PROTEIN that occurs in the body. It has the property of breaking down a THROMBUS in a blood vessel (see THROMBOLYSIS). It is e?ective only in the presence of FIBRIN and activates plasminogen, which occurs normally on the surface of the ?brin. TPA is an important thrombolytic treatment immediately after a myocardial infarction (see HEART, DISEASES OF).... tissue plasminogen activator (tpa, tpa)

Proteins present in blood plasma, including albumin, blood clotting proteins, and immunoglobulins.... plasma proteins

See tissue plasminogen activator.... plasminogen activator

A substance produced by body tissues that prevents abnormal blood clotting. Also called , it is produced by the inner lining of blood vessels. can be prepared artificially for use as a thrombolytic drug, which is called alteplase. This is used in the treatment of myocardial infarction, severe angina pectoris, and arterial embolism, including pulmonary embolism. Possible side effects include bleeding or the formation of a haematoma at the injection site and an allergic reaction. (See also fibrinolysis.)... tissue-plasminogen activator

an endoscopic procedure used predominantly to control bleeding in the gastrointestinal tract. secondary to angiodysplasia and bleeding following polypectomy. Occasionally it is used in the debulking of tumours not amenable to surgery. An intermittent stream of argon gas is delivered through a catheter in the endoscope and ionized by a monopolar electrical current producing a controlled release of thermal energy. This causes coagulation in the adjacent tissues.... argon plasma coagulation

... blood plasma see plasma.

the substance postulated by 19th-century biologists (notably Weismann) to be transmitted via the gametes from one generation to the next and to give rise to the body cells.... germ plasm

a type of *electrocoagulation used to arrest haemorrhage or destroy abnormal tissue. A stream of inert gas, such as argon or helium, is ionized, thereby carrying electrical energy to adjacent tissue; there is no physical contact between the plasma coagulation apparatus and the tissue.... plasma coagulation

n. a malignant tumour of plasma cells, often known as a ‘solitary myeloma’. Although usually occurring as a single tumour in bone marrow or more rarely soft tissue (extramedullary plasmacytoma), it may be multiple, in which case it is classified as a multiple myeloma. All of these tumours may produce the abnormal gammaglobulins that are characteristic of myeloma, and they may progress to widespread myeloma. The soft-tissue tumours often respond to radiotherapy and to such drugs as thalidomide and cyclophosphamide; the bone tumours are typically less responsive.... plasmacytoma

n. a phospholipid, found in brain and muscle, similar in structure to *lecithin and *cephalin.... plasmalogen

enzymes that convert the inactive substance *plasminogen to the active enzyme *plasmin, which digests blood clots (see fibrinolysis). There are two types of plasminogen activators, *tissue-type plasminogen activator (tPA) and urokinase-like plasminogen activator (uPA). See blood coagulation.... plasminogen activators

n. see trophoblast.... plasmoditrophoblast

n. a process occurring in bacteria and plants in which the protoplasm shrinks away from the rigid cell wall when the cell is placed in a *hypertonic solution. Plasmolysis is due to withdrawal of water from the cell by *osmosis.... plasmolysis

(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