| limit dextrin | The polysaccharide fragments remaining at the end (limit) of exhaustive hydrolysis of amylopectin or glycogen by alpha-1,4-glucan maltohydrolase, which cannot hydrolyze the alpha-1,6 bonds at branch points; accumulates in individuals with type III glycogen storage disease. Synonym: dextrin limit. (05 Mar 2000) |
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| limit dextrinase | <enzyme> An enzyme with action similar to that of isoamylase; it cleaves 1,6-alpha-glucosidic linkages in pullalan, amylopectin, and glycogen, and in alpha-and beta-amylase limit-dextrins of amylopectin and glycogen. Compare: isoamylase. Synonym: limit dextrinase, pullulanase, R enzyme. (05 Mar 2000) |
| limit dextrinosis | Glycogenosis due to amylo-1,6-glucosidase deficiency, resulting in accumulation of abnormal glycogen with short outer chains in liver and muscle. Synonym: Cori's disease, debranching deficiency limit dextrinosis, limit dextrinosis, Forbes' disease. (05 Mar 2000) |
| limit of resolution | 1. <optics> The resolution of an optical system defines the closest proximity of two objects that can be seen as two distinct regions of the image. This limit depends upon the Numerical Aperture of the optical system, the contrast step between objects and background and the shape of the objects. The often quoted Airy limit applies only to self luminous discs. 2. <genetics> The smallest map distance measurable by an experiment involving a certain number of classified recombinant progency. (10 Mar 1998) |
| absorbed dose | The amount of energy absorbed per unit mass of irradiated material at the target site; in radiation therapy, the former unit for absorbed dose is the rad; the current (S.I.) unit is the gray. (05 Mar 2000) |
| air dose | The radiation dose, expressed in roentgens, delivered at a point in free air. Synonym: air dose. (05 Mar 2000) |
| bone marrow dose | The cumulative dose to the blood-forming organ from therapeutic or nuclear fallout irradiation; the presumed leukemogenic dose. (05 Mar 2000) |
| booster dose | A dose given at some time after an initial dose to enhance the effect, said usually of antigens for the production of antibodies. (05 Mar 2000) |
| breast dose in mammography | <radiology> 180 mrad / view -- mid-breast dose, guideline: less than 1 rad for 2-view exam (12 Dec 1998) |
| maintenance dose | In chemotherapy, systematic dosage at a level that maintains protection against exacerbation. (05 Mar 2000) |
| genetically significant dose | <physics, radiobiology> The genetically significant dose is that which, if received by every member of the population, would be expected to produce the same genetic injury to the population as do the actual doses received by the individuals irradiated. Thus, the genetically significant dose is the dose equivalent to the gonads weighted for the age and sex distribution in those members of the irradiated population expected to have offspring. The genetically significant dose is expressed in sieverts (or rem). Acronym: GSD (06 Aug 1998) |
| maximal dose | <pharmacology> The largest amount of a drug or physical procedure that an adult can take with safety. (05 Mar 2000) |
| maximum permissible dose | <radiobiology> Defined by the International Commission on Radiological Protection as the greatest dose of radiation which, in the light of present knowledge, is not expected to cause detectable bodily injury to a person at any time during his lifetime. This dose has been reduced with each Commission report. The MPD is given in terms of acute or chronic exposure of the whole body or of organs, systems, or regions of the body, and differs for persons who are occupationally exposed versus the public at large. (05 Mar 2000) |
| median effective dose | The dose that produces the desired effect; when followed by a subscript (generally "ED50"), it denotes the dose having such an effect on a certain percentage (e.g., 50%) of the test animals; ED50 is the median effective dose, in radiation protection, the sum of the equivalent doses in all tissues and organs of the body weighted for tissue effects of radiation. The unit of effective dose is the sievert (Sv), epilation dose, the minimum amount of radiation sufficient to produce hair loss, usually in 10 to 14 days. (05 Mar 2000) |
| gonadal dose | The exposure dose to the male or female gonad, usually from incidental secondary radiation in diagnostic or therapeutic irradiation, or from whole-body irradiation. Synonym: gonadal dose. (05 Mar 2000) |