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A chromosomal disease, often associated with mental retardation, in which the tip of the long arm of the X chromosome can separate from the rest of the genetic material. This is the most common of the X-linked mental retardation syndromes. Most males and 30% of females with this syndrome are mentally retarded. Males also develop greatly enlarged testicles (macro-orchidism), enlarged ears, and a prominent jaw.
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(fră-jĭl′ĭ-tăs) [L.] Fragility.
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(fră-jĭl′ĭt-ē) Brittleness; having the property of being readily broken, injured, or damaged.
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bone f., bony f. Any structural defect of bone that increases the likelihood of fracture. Common diseases that increase bone fragility include osteoporosis and osteomalacia.
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capillary f. A breakdown of capillaries with hemorrhage into almost any site but most noticeably in the skin.
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f. of red blood cells The tendency of red blood cells to rupture. This is determined by subjecting the cells to different concentrations of saline in laboratory tests.
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If red blood cells are placed in distilled water, they swell rapidly and burst because they normally are suspended in a solution of much greater osmotic pressure. This phenomenon is called hemolysis. If they are suspended in a solution of normal saline, the cells retain their normal shape and do not burst. If they are placed in successively weaker solutions of saline, a point is reached at which some of the cells burst and liberate their hemoglobin within a given length of time. Finally, at a given dilution, all the cells have burst within the allotted time, which is usually 2 hr. Normal blood cells begin to hemolyze in about 0.44% saline solution, and complete hemolysis occurs in about 0.35% solution.
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(frăg′mĕnt) A part broken off a larger entity.
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Fab f. Area on an immunoglobulin (antibody) to which antigens bind. The enzyme papain splits antibodies into three fragments, two Fab fragments, each of which is antigen-specific, and an Fc or crystallizable fragment, which is involved in secondary antibody activities such as activating complement.
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immunoglobulin f. The portion of the IgG molecule that contains an antibody-combining site. Specific fragments are obtained by treating the molecule with the enzyme papain under specified conditions. The resultant fragments are designated "F(zz) Fragment, " where zz represents the specific fragment. SYN: immunoglobulin isotype.
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fragment antigen binding
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ABBR: Fab. Area on an immunoglobulin (antibody) to which antigens bind.
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(frăg″mĕn-tā′shŭn) [L. fragmentum, detached part] Breaking up into pieces.
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sleep f. Arousals and awakenings that disrupt the normal stages and architecture of sleep. These events, which occur commonly in patients who have sleep apnea ...