| IC | icteric, icterus; immune complex; immunoconjugate; immunocytochemistry; immunocytotoxicity; impedanc... |
|---|---|
| ICA | Institute of Clinical Analysis; internal carotid artery; intracranial aneurysm; islet cell antibody |
| ICAb | islet cell antibody |
| ICSA | islet cell surface antibody |
| IPITA | International Pancreas and Islet Transplant Association |
| islet | A small island. (05 Mar 2000) |
|---|---|
| islet cell | <pathology> Cells of the Islets of Langerhans within the pancreas. See: A cells, B-cells, D cells. (18 Nov 1997) |
| islet cell adenoma | <tumour> A benign neoplasm of the pancreas composed of tissue similar in structure to that of the islets of Langerhans; it may contain functioning beta cells, and may cause hypoglycaemia. See: insulinoma. Synonym: nesidioblastoma. (05 Mar 2000) |
| islet cell antibodies | In first-degree relatives of probands with insulin-dependent diabetes mellitus the presence of high titre ICA of the IgG cytoplasmic variety (IgG -ICA) and ICA of the complement-fixing subgroup (CF-ICA) confer a relative risk of 75 for development of insulin-dependent diabetes mellitus. The presence of ICA combined with a decrease in the first-phase of insulin secretion ( less than 25 micro U/mL) is predictive with a 95% likelihood of the development of insulin-dependent diabetes mellitus within 12 months. Reproducible results among laboratories are possible with careful attention to selection of the human pancreas as substrate as well as to the use of dilutions to generate standard curves and to the conversion of results to units. The prozone phenomena described elsewhere are not common in our experience. Fifty percent of relatives with a single positive ICA test will develop insulin-dependent diabetes mellitus within 10 years, and 60-80% of relatives with both ICA and insulin autoantibodies (IAA) will develop insulin-dependent diabetes mellitus within 10 years. The predictive value for health of negative results for ICA and IAA is almost 99%. Strong, persistently positive ICA (i.e., 40 JDF U or greater), especially if accompanied by markedly decreased insulin secretion, are the best predictors of subsequent development of insulin-dependent diabetes mellitus. The 64 kD beta-cell autoantigen long thought to be an important target for ICA is not yet available from expression cloning despite efforts by several groups.13 ICA positivity correlates with rapid loss of C-peptide secretory capacity in newly diagnosed ICA-positive insulin-dependent diabetes mellitus. The predictive values of ICA for development of insulin-dependent diabetes mellitus within 10 years in first-degree relatives of patients with insulin-dependent diabetes mellitus increase from 40% at low levels of ICA to 100% at high levels, whereas the sensitivity is 88% at low levels and 31% at high levels. In general, the risk of insulin-dependent diabetes mellitus in relatives of probands increases with titre of ICA, is greater in multiplex families, and is increased in those less than 10 years of age with positive ICA. Although the prevalence of ICA in Japanese with autoimmune thyroid disease resembles that in Caucasians, the incidence of insulin-dependent diabetes mellitus in the Japanese population is only 1/30 - 1/50 that in Caucasians. Prediabetics positive for ICA and IAA have increased suppressor-inducer (CD45R) and decreased helper-inducer (CDw29) peripheral blood lymphocytes. In two randomised, prospective, placebo-controlled studies of recent-onset insulin-dependent diabetes mellitus, cyclosporine immunosuppression increased the rate of non-insulin-requiring remissions as well as beta-cell function during drug treatment. Although 12 months of cyclosporine therapy decreases titres of ICA and insulin antibodies (IA) and increases glucagon-stimulated levels of serum C-peptide, the determination of ICA and IA and HLA-DR type are of no predictive value in selecting recent- onset insulin-dependent diabetes mellitus. Patients for cyclosporine immunointervention. Genetic control of autoimmunity in insulin-dependent diabetes mellitus is reviewed. EIA for autoantibodies to a 64 kD islet-cell protein is promising for prediction of insulin-dependent diabetes mellitus, but sensitivity and specificity are still suboptimal. See also: insulin antibodies. (05 Mar 2000) |
| islet cell antigen-related protein-tyrosine phosphatase | <enzyme> Receptor-like autoantigen found in insulin-dependent diabetes; genbank l76258 Registry number: EC 3.1.3.- Synonym: iar ptp (26 Jun 1999) |
| islet-cell-stimulating antibodies | <immunology> Autoantibodies to a putative beta-cell receptor; stimulate the release of insulin both in rodents and man; may be analogous to the thyroid stimulating antibodies that cause grave's hyperthyroidism Synonym: icsta (05 Dec 1998) |
| islet neogenesis-associated protein | <chemical> Constituent of ilotropin; stimulates proliferation of pancreatic ductal cells in vitro; from hamsters and humans; amino acid sequence given in first source Synonym: ingap protein, ingap gene product (05 Dec 1998) |
| islet tissue | <anatomy> Groups of cells found within the pancreas: A cells and B-cells secrete insulin and glucagon. See: D cells. (18 Nov 1997) |
| amyloid | Glycoprotein deposited extracellularly in tissues in amyloidosis. The glycoprotein may either derive from light chain of immunoglobulin (AIO (amyloid of immune origin): 5-18 kD glycoprotein, product of a single clone of plasma cells, the N terminal part of lambda or kappa light chain) or, in what used to be referred to as AUO, amyloid of unknown origin, from serum amyloid A (SAA), one of the acute phase proteins that increases many fold in inflammation. The polypeptides are organised as a _ pleated sheet making the material rather inert and insoluble. Minor protein components are also found. Should be distinguished from _ amyloid deposited in the brain and that is derived from amyloid precursor protein (see amyloidogenic glycoprotein. (18 Nov 1997) |
| amyloid A-degrading serine protease | <enzyme> Reduced in amyloidosis associated with rheumatoid arthritis Registry number: EC 3.4.21.- Synonym: amyloid a-degrading activity, aad-protease (26 Jun 1999) |
| amyloid angiopathy | Deposition of acellular hyaline material in small arteries and arterioles of the leptomeninges and cerebral cortex in the elderly with resulting predilection for recurrent lobar intraparenchymal haematomas. (05 Mar 2000) |
| amyloid beta-protein | A 4 kD protein, 39-43 amino acids long, expressed by a gene located on chromosome 21. It is the major protein subunit of the vascular and plaque amyloid filaments in individuals with alzheimer's disease and in aged individuals with trisomy 21 (down syndrome). The protein is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue. (12 Dec 1998) |
| amyloid beta-protein precursor | A precursor to the amyloid-beta protein (beta/a4). Alterations in the expression of the amyloid beta-protein precursor (abpp) gene, located on chromosome 21, plays a role in the development of the neuropathology common to both alzheimer disease and down syndrome. Abpp is associated with the extensive extracellular matrix secreted by neuronal cells. Upon cleavage, this precursor produces three proteins of varying amino acid lengths: 695, 751, and 770. The beta/a4 (695 amino acids) or beta-amyloid protein is the principal component of the extracellular amyloid in senile plaques found in alzheimer disease, down syndrome and, to a limited extent, in normal aging. (12 Dec 1998) |
| amyloid bodies of the prostate | An obsolete term for small masses of colloid material often present in the tubules of the gland. See: corpus amylaceum. (05 Mar 2000) |
| amyloid corpuscle | One of a number of small ovoid or rounded, sometimes laminated, bodies resembling a grain of starch and found in nervous tissue, in the prostate, and in pulmonary alveoli; of little pathological significance, and apparently derived from degenerated cells or proteinaceous secretions. Synonym: amniotic corpuscle, amylaceous corpuscle, amyloid corpuscle, colloid corpuscle. (05 Mar 2000) |