| membrane fracture | 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) |
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| chance fracture | <radiology> Horizontal fracture through vertebra (body, pedicles, laminae), sudden deceleration with lap-only seatbelt, usually L1 or L2 (12 Dec 1998) |
| Gosselin's fracture | V-shaped fracture of distal end of tibia. (05 Mar 2000) |
| chauffer's fracture | A fracture of the wrist that is characterised by an oblique fracture of the radial styloid. (27 Sep 1997) |
| chauffeur's fracture | <radiology> Radial styloid fracture due to direct blow, (so named because of trauma from hand-cranked starters) see: wrist fractures (12 Dec 1998) |
| chisel fracture | <radiology> Incomplete fracture of radial head (intra-articular) due to fall on outstretched hand (12 Dec 1998) |
| greenstick fracture | The bending of a bone with incomplete fracture involving the convex side of the curve only. (05 Mar 2000) |
| growing fracture | Linear skull fracture in a young child which increases in size, usually as the result of an associated dural tear and arachnoid cyst formation within the fracture line. (05 Mar 2000) |
| pertrochanteric fracture | A fracture through the great trochanter of the femur; a form of extracapsular hip fracture. (05 Mar 2000) |
| Guerin's fracture | A fracture of the facial bones in which there is a horizontal fracture at the base of the maxillae above the apices of the teeth. Synonym: horizontal fracture, Le Fort I fracture. (05 Mar 2000) |
| chopart fracture-dislocation | <radiology> A fracture-dislocation occuring through the hindfoot-midfoot joint (i.e., tarsonavicular and calcaneocuboid joints) (12 Dec 1998) |
| gutter fracture | A long, narrow, depressed fracture of the skull. (05 Mar 2000) |
| clay shoveler's fracture | <radiology> Avulsion fracture of spinous process of C7 or T1, sudden load on a flexed spine, may occur secondary to rotational injury see: cervical spine fractures (12 Dec 1998) |
| closed fracture | A fracture in which skin is intact at site of fracture. Synonym: simple fracture. (05 Mar 2000) |
| closed skull fracture | Fracture with intact overlying scalp and/or mucous membranes. Synonym: simple skull fracture. (05 Mar 2000) |