| gram-molecular weight | Molecular weight expressed in grams. Compare: mole. (05 Mar 2000) |
|---|---|
| molecular weight | The sum of the atomic weight's of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units. See: atomic weight. Synonym: molecular mass, molecular weight ratio, relative molecular mass. (05 Mar 2000) |
| molecular weight ratio | The sum of the atomic weight's of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units. See: atomic weight. Synonym: molecular mass, molecular weight ratio, relative molecular mass. (05 Mar 2000) |
| heparin, low-molecular-weight | <chemical> Heparin fractions with a molecular weight usually between 4000 and 6000 kD. These low-molecular-weight fractions are effective antithrombotic agents. Their administration reduces the risk of haemorrhage, they have a longer half-life, and their platelet interactions are reduced in comparison to unfractionated heparin. They also provide an effective prophylaxis against postoperative major pulmonary embolism. Pharmacological action: anticoagulant, fibrinolytic agent. (12 Dec 1998) |
| kininogen, high-molecular-weight | A plasma protein, molecular weight of 110 kD, that normally exists in plasma in a 1:1 complex with prekallikrein. Hmwk is split by plasma kallikrein to produce bradykinin. The complex is a cofactor in the activation of coagulation factor xii. The product of this reaction, xiia, in turn activates prekallikrein to kallikrein. (12 Dec 1998) |
| kininogen, low-molecular-weight | A protein, molecular weight 50 kD, located in various normal tissues. Upon cleavage by kallikrein or other kallikreins, it forms kallidin. Kallidin, in turn, is converted into bradykinin. (12 Dec 1998) |
| GI-tract target lesion | <radiology> Metastatic melanoma, primary neoplasm, spindle cell tumour (benign or malignant), lymphoma, carcinoid, carcinoma, metastasis, breast carcinoma, lung carcinoma, renal carcinoma, Kaposi's sarcoma, eosinophilic granuloma, ectopic pancreas (12 Dec 1998) |
| molybdenum target tube | An X-ray tube with an anode surface made of molybdenum instead of tungsten, used in mammography. (05 Mar 2000) |
| target | 1. An object fixed as goal or point of examination. 2. In the ophthalmometer, the mire. Synonym: target organ. 4. Anode of an X-ray tube. See: X-ray. Origin: It. Targhetta, a small shield (05 Mar 2000) |
| target behaviour | Operant in behaviour modification therapy, the prescribed behaviour. (05 Mar 2000) |
| target cell | An erythrocyte in target cell anaemia, with a dark centre surrounded by a light band that again is encircled by a darker ring; it thus resembles a shooting target; such cell's also appear after splenectomy. A cell lysed by cytotoxic T lymphocytes, as in graft rejection. Synonym: Mexican hat cell. (05 Mar 2000) |
| target cell anaemia | Any anaemia with a conspicuous number of target cells in the peripheral blood; characteristic of the thalassaemias and also found in several haemoglobinopathies. (05 Mar 2000) |
| target gland | The effector that functions when stimulated by the internal secretion of another gland or by some other stimulus. (05 Mar 2000) |
| target lesions of liver/spleen | <radiology> Lymphosarcoma (including Kaposi sarcoma), melanoma (12 Dec 1998) |
| target organ | A tissue or organ upon which a hormone exerts its action; generally, a tissue or organ with appropriate receptors for a hormone. Synonym: target. (05 Mar 2000) |