| universal donor | In blood grouping, a person belonging to group O; i.e., one whose erythrocytes do not contain either agglutinogen A or B and are, therefore, not agglutinated by plasma containing either of the ordinary isoagglutinins, alpha or beta. (05 Mar 2000) |
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| universal gas constant | <radiobiology> R = 8.314 x 10^7 ergs per degree C per mole. (09 Oct 1997) |
| universal infantilism | Dwarfism generally associated with hypogonadism; may be caused by deficient secretion of anterior pituitary hormones. Synonym: Lorain's disease, proportionate infantilism, universal infantilism. (05 Mar 2000) |
| universal instability | <radiobiology> Low-frequency instability resulting from the presence of density gradients perpendicular to the magnetic field lines. An instability of this type is generally localised and usually has a small rate of growth. (09 Oct 1997) |
| universal numerical notation for teeth | <dentistry> The universal numerical notation is an alternative numerical notation for teeth. In this notation, your upper right third molar is designated as tooth#1, and then you number each tooth sequentially moving right to left and down across your mouth. (08 Jan 1998) |
| universal precautions | Prudent standard preventive measures to be taken by professional and other health personnel in contact with persons afflicted with a communicable disease, to avoid contracting the disease by contagion or infection. Precautions are especially applicable in the diagnosis and care of aids patients. (12 Dec 1998) |
| universal solvent | A substance sought by the alchemists, and claimed by some to have been found, supposedly capable of dissolving all substances; sometimes, in a physiological sense, applied to water. (05 Mar 2000) |
| universal tube | A straight, cylindrical glass vial that holds about 25 millilitres and istopped with a screw-on cap. (09 Oct 1997) |
| bird face | bird face, abnormal shortness or recession of the mandible (27 Sep 1997) |
| masklike face | The expressionless or masklike facies characteristic of parkinsonism. Synonym: masklike face. (05 Mar 2000) |
| partial face-sparing lipodystrophy | A syndrome beginning at puberty that resembles total lipodystrophy but is inherited as an autosomal or X-linked dominant form. (05 Mar 2000) |
| regions of face | The topographical subdivisions of the face, including nasal, oral, mental, orbital, infraorbital, buccal, and zygomatic. Synonym: regiones faciales. (05 Mar 2000) |
| P face | Method of specimen preparation for the electron microscope in which rapidly frozen tissue is cracked so as to produce a fracture plane through the specimen. The surface of the fracture plane is then shadowed by heavy metal vapour, strengthened by a carbon film and the underlying specimen is digested away, leaving a replica that can be picked up on a grid and examined in the transmission electron microscope. The great advantage of the method is that the fracture plane tends to pass along the centre of lipid bilayers and it is therefore possible to get en face views of membranes that reveal the pattern of Integral membrane proteins. The E face is the outer lamella of the plasma membrane viewed as if from within the cell, the P face the inner lamella viewed from outside the cell. Fracture planes also often pass along lines of weakness such as the interface between cytoplasm and membrane, so that outer and inner membrane surfaces can be viewed. Further information about the structure can be revealed by freeze etching. Extremely rapid freezing followed by deep etching has allowed the structure of the cytoplasm to be studied without the artefacts that might be introduced by fixation. (18 Nov 1997) |
| moon face | The round, usually red face, with large jowls, seen in Cushing's disease or in exogenous hyperadrenocorticalism. Moon shaped face, moon facies. (05 Mar 2000) |
| whistling face syndrome | Congenital association of skeletal defects (ulnar deviation of hands with camptodactyly, talipes equinovarus, and frontal bone defects) and characteristic facies (protrusion of lips as in whistling, sunken eyes with hypertelorism, and small nose); autosomal dominant inheritance. Synonym: craniocarpotarsal dysplasia, Freeman-Sheldon syndrome, whistling face syndrome. (05 Mar 2000) |