| MBLA | methylbenzyl linoleic acid; mouse-specific bone-marrow-derived lymphocyte antigen |
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| NBI | neutrophil bactericidal index; no bone injury; non-battle injury |
| NBM | no bowel movement; normal bone marrow; normal bowel movement; nothing by mouth |
| NBME | National Board of Medical Examiners; normal bone marrow extract |
| PBM | peak bone mass; peripheral basement membrane; peripheral blood mononuclear [cell]; placental basemen... |
| Fc receptors | <immunology> Receptors for the Fc portion of immunoglobulins. Fc_R (30 kD) is the receptor for serum and secretory IgA1 or IgA2 and is expressed on most myeloid cells and subpopulations of T and B-cells. Fc_RI (CD64) High affinity receptor (72 kD on gels) for monomeric IgG1 found on monocytes, macrophages and some neutrophils. The extracellular portion has three immunoglobulin superfamily C2 domains, in contrast to Fc_RII, Fc_RIII that have only two. Involved in antibody dependent cell killing and in clearance of immune complexes. Fc_RII (CD32) Low affinity receptor 40 kD) for aggregated IgG that exists in several sub types coded by three closely related genes, A, B and C. All forms are found on monocytes, the B forms (that are alternatively spliced) are found on B-cells, the A and C forms are present on neutrophils. Binding of aggregated IgG will trigger phagocytosis and the oxidative burst in neutrophils. Fc_RIII (CD16) is the low affinity receptor (50-80 kD on gels) for aggregated IgG. It is found in transmembrane and GPI linked forms. The transmembrane form associates with the _ subunit of Fc_RI or the TCR_ chain and on B-cells with the _ chain of Fc_RI. Has structural similarity with Fc_RI, Fc_RII and Fc_RI_. Binding of aggregated IgG or IgG antigen complexes mediates phagocytosis or antibody dependent cellular cytotoxicity. Fc_RI is a heteromeric high affinity receptor for IgE found on mast cells and basophils. The _ chain (45-65 kD on gels, 25 kD of polypetide) is N glycosylated and has two immunoglobulin C2 loops in addition to the transmembrane domain, the _ chain (32 kD) has four transmembrane domains, the _ subunit is a homodimer (8 kD monomer) identical to the _ subunit of CD16 and has similarity with _ and _ chains associated with the T-cell receptor. Binding of antigen to the IgE Fc_R complex triggers the release of histamine and various inflammatory mediators. Fc_RIIa & b CD23) Low affinity receptor (45 kD) for IgE. Both a and b are present on mature B-cells, the b form on monocytes, IL-4 activated macrophages, eosinophils, platelets and dendritic cells. The protein has a C type lectin domain that mediates IgE binding and can be cleaved from the membrane to yield an active soluble form. (18 Nov 1997) |
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| low-density lipoprotein receptors | Receptors on the surface of cells, especially liver cells, which bind to low density lipoprotein and promote clearance of LDL from the plasma. (05 Mar 2000) |
| acute reflex bone atrophy | Atrophy of bones, commonly of the carpal or tarsal bones, following a slight injury such as a sprain. See: causalgia, reflex sympathetic dystrophy. Synonym: acute reflex bone atrophy, posttraumatic osteoporosis, Sudeck's syndrome. Origin: L. English sweat (05 Mar 2000) |
| air-bone gap | The difference between the threshold for hearing acuity by bone conduction and by air conduction. (05 Mar 2000) |
| Albrecht's bone | A small bone between the basioccipital and basisphenoid. (05 Mar 2000) |
| allogeneic bone marrow transplant | <haematology, procedure> A bone marrow transplant using marrow collected from a matched healthy donor, usually a brother or sister. The risks associated with the transplant increase with age and 50 years of age is generally regarded as the upper limit. (13 Nov 1997) |
| alveolar bone | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| alveolar bone loss | The resorption of bone in the supporting structures of the maxilla or mandible as a result of periodontal disease. (12 Dec 1998) |
| alveolar supporting bone | alveolar process |
| amyloidosis: bone manifestations | <radiology> Joint pain without radiographic findings, osteoporosis, especially in axial skeleton, lytic lesions that destroy cortex and invade soft tissue, wrist, scaphoid and lunate lesions that may extend into the carpal tunnel, inducing the classic complaints of carpal tunnel syndrome amyloid arthropathy Differential diagnosis: pigmented villonodular synovitis, synovial chondromatosis, rheumatoid arthritis, TB (12 Dec 1998) |
| aneurysmal bone cyst | <radiology> ABC, 10 - 30 yrs, 75% before skeletal maturity, sites: long bones; also, flat bones Findings: metaphyseal if unfused, metaepiphyseal after fusion, lytic, expansile, thin, continuous rim, thin internal bony strands (12 Dec 1998) |
| ankle bone | 1. <anatomy> The astragalus. 2. <surgery> A variety of clubfoot (Talipes calcaneus). See the Note under Talipes. 1. A slope; the inclination of the face of a work. 2. <geology> A sloping heap of fragments of rock lying at the foot of a precipice. Origin: L, the ankle, the ankle bone. (26 Nov 1998) |
| anterior condyloid canal of occipital bone | The canal through which the hypoglossal nerve emerges from the skull. Synonym: canalis hypoglossalis, anterior condyloid canal of occipital bone, anterior condyloid foramen. (05 Mar 2000) |
| anterior surface of petrous part of temporal bone | The surface of the petrous part of the temporal bone contributing to the floor of the middle cranial fossa. Synonym: facies anterior partis petrosae ossis temporalis. (05 Mar 2000) |
| apex of petrous part of temporal bone | The irregular antero-medial extremity of the petrous part on which the anterior end of the carotid canal opens. Synonym: apex partis petrosae ossis temporalis. (05 Mar 2000) |