| line of vision | The straight line extending from the object seen, through the centre of the pupil, to the macula lutea of the retina. Synonym: line of vision. (05 Mar 2000) |
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| abdominal muscle deficiency syndrome | <syndrome> Congenital absence (partial or complete) of abdominal muscles, in which the outline of the intestines is visible through the protruding abdominal wall; in males, genitourinary anomalies (urinary tract dilation and cryptorchidism) are also found; genetics unclear. (05 Mar 2000) |
| adult lactase deficiency | Onset of lactase deficiency, with resulting milk intolerance and malabsorption, in adulthood. Inherited forms may not be manifested until adulthood; any process that damages the intestinal lining cells can cause lactase deficiency in adults. (05 Mar 2000) |
| alpha-1 antitrypsin deficiency | <chest medicine> Deficiency of the protease inhibitor alpha-1 antitrypsin, leads primarily to degradation of elastin of the alveolar walls, as well as other structural proteins of a variety of tissues. The lack of this protein leads to damage of various organs, but mainly to the lung and liver. symptoms may become apparent at a very early age or in adulthood, manifesting either as shortness of breath or liver related symptoms (jaundice, fatigue, fluid in the abdomen, mental changes, or gastrointestinal bleeding). There are several options for treatment of the lung disease, including replacement of the missing protein. Treatment of the liver disease is a well-timed liver transplant (12 Dec 1998) |
| alpha-1-proteinase deficiency | Absence of a serum proteinase inhibitor that may cause nodular non-suppurative panniculitis. (05 Mar 2000) |
| alpha-antitrypsin deficiency | <enzyme> A specific enzyme (alpha 1 antitrypsinase) that when absent genetically can result in panacinar emphysema (lung disease) and liver disease. There is no specific treatment for this condition other than supportive care for the liver and lung complications. Medications such as alpha-1proteinase inhibitor is given regularly to these patients. Incidence: approximately 1 in 10,000. (02 Jan 1998) |
| anaemia, iron deficiency | Deficiency of iron results in anaemia because iron is necessary to make haemoglobin, the key molecule in red blood cells responsible for the transport of oxygen. In iron deficiency anaemia, the red cells are unusally small (microcytic) and pale (hypochromic). Characteristic features of iron deficiency anaemia in children include failure to thrive (grow) and increased infections. The treatment of iron deficiency anaemia, whether it be in children or adults, is with iron and iron-containing foods. Food sources of iron include meat, poultry, eggs, vegetables and cereals (especially those fortified with iron). According to the National Academy of Sciences, the Recommended Dietary Allowances of iron are 15 milligrams per day for women and 10 milligrams per day for men. Anaemia characterised by low or absent iron stores, low serum iron concentration, elevated free erythrocyte porphorin, low transferrin saturation, elevated transferrin, low serum ferritin, low haemoglobin concentration or haematocrit, and hypochromic microcytic red blood cells. Symptoms may include pallor, angular stomatitis and other oral lesions, gastrointestinal complaints, retinal haemorrhages and exudates, and thinning and brittleness of the nails. Among the causes of iron-deficiency anaemia are inadequate iron intake, impaired iron absorption, increased blood loss and increased requirements such as infancy, pregnancy, and lactation. (12 Dec 1998) |
| antibody deficiency disease | <syndrome> Any of a group of disorders associated with a defective antibody production due to defects in the B-type lymphocyte system or in T-type lymphocytes; chief manifestation is an increased susceptibility to infection by various microorganisms. See: agammaglobulinaemia, hypogammaglobulinaemia, immunodeficiency. Synonym: antibody deficiency disease. (05 Mar 2000) |
| antibody deficiency syndrome | <syndrome> Any of a group of disorders associated with a defective antibody production due to defects in the B-type lymphocyte system or in T-type lymphocytes; chief manifestation is an increased susceptibility to infection by various microorganisms. See: agammaglobulinaemia, hypogammaglobulinaemia, immunodeficiency. Synonym: antibody deficiency disease. (05 Mar 2000) |
| antitrypsin deficiency | Deficiency of a1-antitrypsin, a glycoprotein of the postalbumin region of human serum. Many forms are known which may be moderate (40 to 60% of normal activity) or severe (less than 10% of normal), all autosomal dominant; the severe form is often associated with familial emphysema or hepatic cirrhosis. (05 Mar 2000) |
| arch length deficiency | The difference between the available circumference of the dental arch and that required to accommodate the succedaneous teeth in proper alignment. (05 Mar 2000) |
| arginase deficiency | <biochemistry> Arginase is the fifth enzyme of the urea cycle and catalyses the hydrolysis of arginine to ornithine and urea as the final step in the detoxification of ammonia. Deficiency of the enzyme results in hyperargininaemia and episodic hyperammonaemia, leading to moderate to severe mental retardation and spasticity. at least two isozymes of arginase exist in man. AI (the enzyme deficient in the disorder) is cytosolic and found primarily in liver and red blood cells, whereas AII is mitochondrial and found predominantly in kidney but also to a lesser extent in liver, brain, and other tissues. While AII activity appears to be induced in AI deficiency, it is only partially effective in maintaining urea cycle function. The normal in vivo function of AII is unclear. Arginase deficiency is diagnosed by observing high arginine concentrations on either qualitative or quantitative plasma or urine amino acid analysis. The diagnosis is confirmed by finding markedly decreased or absent arginase activity in an isotopic red blood cell enzymatic assay. The AI gene has been cloned, sequenced, and localised to human chromosome band 6q23. (17 Dec 1997) |
| ascorbic acid deficiency | A condition due to a dietary deficiency of ascorbic acid (vitamin c), characterised by malaise, lethargy, and weakness. As the disease progresses, joints, muscles, and subcutaneous tissues may become the sites of haemorrhage. Ascorbic acid deficiency frequently develops into scurvy in young children fed unsupplemented cow's milk exclusively during their first year. It develops also commonly in chronic alcoholism. (cecil textbook of medicine, 19th ed, p1177) (12 Dec 1998) |
| beta-d-glucuronidase deficiency | A rare deficiency of beta-d-glucuronidase; an autosomal recessive disorder with several allelic forms, characterised by abnormal mucopolysaccharide metabolism leading to progressive mental deterioration, splenic and hepatic enlargement, and dysostosis multiplex. Synonym: mucopolysaccharidase. (05 Mar 2000) |
| brancher deficiency glycogenosis | Type of glycogen storage disease, due to deficiency of amylo-1,4-1,6-transglucosidase (brancher enzyme). Synonym: brancher deficiency glycogenosis, debrancher deficiency. (05 Mar 2000) |