| ion exchange chromatography | <procedure> Separation of molecules by absorption and desorption from charged polymers. An important technique for protein purification. For small molecules the support is usually polystyrene, but for macromolecules, cellulose, acrylamide or agarose supports give less non-specific absorption and denaturation. Typical charged residues are CM carboxymethyl) or DEAE (diethylaminoethyl). (27 Oct 1998) |
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| ion exchange resin | <chemistry> A resin of polymers that havefixed charged groups which is used in chromatographic columns to separate ions. (27 Oct 1998) |
| ion exchange resins | <chemistry> High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ion exchange) with either cations or anions. See: ion exchange, ion exchanger. (12 Dec 1998) |
| exchange | 1. To part with give, or transfer to another in consideration of something received as an equivalent; usually followed by for before the thing received. "Exchange his sheep for shells, or wool for a sparking pebble or a diamond." (Locke) 2. To part with for a substitute; to lay aside, quit, or resign (something being received in place of the thing with); as, to exchange a palace for cell. "And death for life exchanged foolishly." (Spenser) "To shift his being Is to exchange one misery with another." (Shak) 3. To give and receive reciprocally, as things of the same kind; to barter; to swap; as, to exchange horses with a neighbor; to exchange houses or hats. "Exchange forgiveness with me, noble Hamlet." (Shak) Synonym: To barter, change, commute, interchange, bargain, truck, swap, traffic. Origin: Cf.OF. Eschangier, F. Echanger. See Exchange. 1. The act of giving or taking one thing in return for another which is regarded as an equivalent; as, an exchange of cattle for grain. 2. The act of substituting one thing in the place of another; as, an exchange of grief for joy, or of a scepter for a sword, and the like; also, the act of giving and receiving reciprocally; as, an exchange of civilities or views. 3. The thing given or received in return; especially, a publication exchanged for another. 4. The process of setting accounts or debts between parties residing at a distance from each other, without the intervention of money, by exchanging orders or drafts, called bills of exchange. These may be drawn in one country and payable in another, in which case they are called foreign bills; or they may be drawn and made payable in the same country, in which case they are called inland bills. The term bill of exchange is often abbreviated into exchange; as, to buy or sell exchange. A in London is creditor to B in new York, and C in London owes D in New York a like sum. A in London draws a bill of exchange on B in New York; C in London purchases the bill, by which A receives his debt due from B in New York. C transmits the bill to D in New York, who receives the amount from B. 5. A mutual grant of equal interests, the one in consideration of the other. Estates exchanged must be equal in quantity, as fee simple for fee simple. 6. The place where the merchants, brokers, and bankers of a city meet at certain hours, to transact business. In this sense often contracted to 'Change. Arbitration of exchange. See Arbitration. Bill of exchange. See Bill. Exchange broker. See Broker. Par of exchange, the established value of the coin or standard of value of one country when expressed in the coin or standard of another, as the value of the pound sterling in the currency of France or the United States. The par of exchange rarely varies, and serves as a measure for the rise and fall of exchange that is affected by the demand and supply. Exchange is at par when, for example, a bill in new York, for the payment of one hundred pounds sterling in London, can be purchased for the sum. Exchange is in favor of a place when it can be purchased there at or above par. Telephone exchange, a central office in which the wires of any two telephones or telephone stations may be connected to permit conversation. Synonym: Barter, dealing, trade, traffic, interchange. Origin: OE. Eschange, eschaunge, OF. Eschange, fr. Eschangier, F. Echanger, to exchange; pref. Ex- out + F. Changer. See Change, and cf. Excamb. Source: Websters Dictionary (01 Mar 1998) |
| arterial transfusion | Direct transfusion from an artery of the donor into an artery of the receptor. (05 Mar 2000) |
| blood component transfusion | The transfer of blood components such as erythrocytes, leukocytes, platelets, and plasma from a donor to a recipient or back to the donor. This process differs from the procedures undertaken in plasmapheresis and types of cytapheresis (plateletpheresis and leukapheresis) where, following the removal of plasma or the specific cell components, the remainder is transfused back to the donor. (12 Dec 1998) |
| blood transfusion | The process of infusing blood products into a patient to raise the individuals concentration of red blood cells. Blood is typed (A, B, O or AB) and crossmatched (mixed together to see if its compatible) prior to transfusion. (27 Sep 1997) |
| blood transfusion, autologous | Reinfusion of blood or blood products derived from the patient's own circulation. (12 Dec 1998) |
| blood transfusion, intrauterine | Transfusion of rh-negative blood into the peritoneal cavity of an unborn infant in the treatment of foetal erythroblastosis (erythroblastosis, foetal) in utero. (12 Dec 1998) |
| blood transfusion reaction | This refers to an immune response against transfused blood cells. Antigens, on the surface of red blood cells, are recognised as foreign proteins and can stimulate sensitised lymphocytes to produce antibodies to the red blood cell antigens. This triggers a complex immunological reaction that results in the destruction of the transfused red blood cell. The blood groups (A, B, AB, O) are classified on the basis of the presence of surface antigens on the red blood cell. Type A blood has A antigens. The plasma component of the blood contains the antibodies against all other blood group antigens other that its own. Another type of surface antigen is known as Rh factor. Rh factor is either present (Rh positive) or absent (Rh negative). Rh compatibility is another requirement for blood transfusion. Symptoms and findings of a transfusion reaction include flank pain, fever, chills, bloody urine, rash, low blood pressure, dizziness and fainting. (27 Sep 1997) |
| reciprocal transfusion | An attempt to confer immunity by transfusing blood taken from a donor into a receiver suffering from the same affection, the balance being maintained by transfusing an equal amount from the receiver to the donor. (05 Mar 2000) |
| mediate transfusion | Transfusion into a patient of blood previously obtained from a donor and stored in a suitable container. Synonym: mediate transfusion. (05 Mar 2000) |
| peritoneal transfusion | The injection of saline solution or other fluid into the peritoneal cavity. (05 Mar 2000) |
| placental transfusion | Return to the newborn via the umbilical vessels some of the foetal placental blood. (05 Mar 2000) |
| platelet transfusion | The transfer of blood platelets from a donor to a recipient or reinfusion to the donor. (12 Dec 1998) |