| OPCAB | Off-pump coronary artery bypass grafting |
|---|---|
| PGR | Pulse Generated Run-off |
| TTO | Time Trade OFF |
| ordered on-random off mechanism | A scheme for substrate binding and product release for multisubstrate enzymes; for a two-substrate two-product enzyme with this mechanism, the individuals have to bind to the enzyme in a distinct order; however, once the products are formed they may dissociate from the enzyme in either order. It has been suggested that pyruvate kinase has such a mechanism. The random on-ordered off mechanism is simply the reverse of this mechanism. (05 Mar 2000) |
|---|---|
| Gant's clamp | A right-angled clamp used in haemorrhoidectomy. (05 Mar 2000) |
| Gaskell's clamp | An instrument for crushing the atrioventricular bundle in experimental animals and thus producing heart block. (05 Mar 2000) |
| Rankin's clamp | A three-bladed clamp used in resection of colon. (05 Mar 2000) |
| gingival clamp | A springlike metal piece encircling or grasping the cervix of a tooth and shaped so as to retract the gingival tissue. (05 Mar 2000) |
| patch clamp | <physiology> A specialised and powerful variant of voltage clamping, in which a patch electrode of relatively large tip diameter (5m) is pressed tightly against the plasma membrane of a cell, forming an electrically tight, gigohm seal. The current flowing through individual ion channels can then be measured. Different variants on this technique allow different surfaces of the plasma membrane to be exposed to the bathing medium: the contact just described is a cell attached patch. If the electrode is pulled away, leaving just a small disc of plasma membrane occluding the tip of the electrode, it is called an inside out patch. If suction is applied to a cell attached patch, bursting the plasma membrane under the electrode, a whole cell patch (similar to an intracellular recording) is formed. If the electrode is withdrawn from the whole cell patch, the membrane fragments adhering to the electrode reform a seal across the tip, forming an outside out patch. (15 Mar 2000) |
| patch-clamp techniques | An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used. (15 Mar 2000) |
| Payr's clamp | A clamp used in gastrectomy or enterectomy. (05 Mar 2000) |
| glucose clamp technique | <technique> Maintenance of a constant blood glucose level by perfusion or infusion with glucose or insulin. It is used for the study of metabolic rates (e.g., in glucose, lipid, amino acid metabolism) at constant glucose concentration. (12 Dec 1998) |
| voltage clamp | <physiology, technique> A technique in electrophysiology, in which a microelectrode is inserted into a cell and current injected through the electrode so as to hold the cells membrane potential at some predefined level. The technique can be used with separate electrodes for voltage sensing and current passing, for small cells, the same electrode can be used for both. Voltage clamp is a powerful technique for the study of ion channels. See: patch clamp. (18 Nov 1997) |
| Goldblatt's clamp | A clamp applied experimentally to the renal artery to damp pulse pressure and thereby produce chronic hypertension by activation of the renin-angiotensin system. (05 Mar 2000) |
| right angle clamp | A clamp with a short 90 |
| rubber dam clamp | A springlike metal piece encircling or grasping the cervix of a tooth and so shaped as to prevent a rubber dam from coming off the tooth. (05 Mar 2000) |
| rubber dam clamp forceps | A forceps with pronged jaws designed to engage the jaws of a rubber dam clamp so that they may be separated to pass over the widest buccolingual contour of a tooth. Synonym: rubber dam clamp forceps. (05 Mar 2000) |
| rubber shod clamp | A small rubber-tipped clamp that holds sutures in place during surgery. (05 Mar 2000) |