| focal sclerosis with hyalinosis | <nephrology> A kidney disorder that results in fibrosis and scarring in the kidney glomerulus. The cause is unknown but some cases can result from reflux nephropathy. The clinical manifestation of this kidney disorder is nephrotic syndrome. Symptoms include weight gain, swelling, hypertension and foamy urine. High blood cholesterol and triglyceride levels are also seen with this disorder. Treatment has included the use of corticosteroids and immunosuppressives. Antihypertensive agents and diuretics may also be necessary. Over one-half will develop chronic renal failure within 10 years of diagnosis. (27 Sep 1997) |
|---|---|
| focal segmental glomerulosclerosis | <nephrology> A kidney disorder that results in fibrosis and scarring in the kidney glomerulus. The cause is unknown but some cases can result from reflux nephropathy. The clinical manifestation of this kidney disorder is nephrotic syndrome. Symptoms include weight gain, swelling, hypertension and foamy urine. High blood cholesterol and triglyceride levels are also seen with this disorder. Treatment has included the use of corticosteroids and immunosuppressives. Antihypertensive agents and diuretics may also be necessary. Over one-half will develop chronic renal failure within 10 years of diagnosis. (27 Sep 1997) |
| focal seizure | <neurology> A brief temporary alteration in movement, sensation or autonomic nerve function caused by abnormal electrical activity in a localised area of the brain. Focal seizures (i.e. Partial or Jacksonian seizures) usually cause no change in awareness or alertness. An example of a focal (partial) seizure would be rhythmic muscle contractions in one area of the body: lip smacking, mouth movements, drooling, head turning, eye movements or seemingly purposeful movements (for example picking at clothes). Other presentations may be strictly sensory with abnormal numbness, tingling or a crawling sensation to the skin. More unusual symptoms include changes in speech, thought, personality, mood, sensation of deja vu or hallucinations. (05 Jan 1998) |
| focal spot | The site of bombardment by electrons and emission of X-rays from the anode of an X-ray tube. See: focal spot size. (05 Mar 2000) |
| focal spot size | The measured size of a focal spot, a function of its actual size and the angulation of the anode surface. See: focal spot. (05 Mar 2000) |
| foci | Plural of focus. The origin or centre of a disseminated disease. (16 Dec 1997) |
| focimeter | An instrument to measure the power and cylindrical axis of a spectacle lens. Synonym: focimeter, vertometer. Origin: Lens + G. Metron, measure (05 Mar 2000) |
| focus | Group of (frequently neoplastic) cells, identifiable by distinctive morphology or histology. (18 Nov 1997) |
| focus groups | A method of data collection and a qualitative research tool in which a small group of individuals are brought together and allowed to interact in a discussion of their opinions about topics, issues, or questions. (12 Dec 1998) |
| focus, principal | <physics> The point at which a lens focuses an axial object point. Synonymous with focal point. (05 Aug 1998) |
| focus-forming assay | <investigation> A lab technique used to find out if a particular piece of DNA contains oncogenes (genes which are associated with cancer). This is done by putting the DNA into animal cells which normally show contact inhibition, or which stop growing when they come into physical contact with other cells or reach a certain density in the culture. If the cells lose contact inhibition and form areas of densely-packed cells (called foci) after receiving the DNA, it means that the DNA did contain oncogenes. (05 Jan 1997) |
| focus-forming unit | A measurement of the concentration of live virus in a given amount of fluid. This is measured by spreading a known amount of the fluid over a layer of cultured cells which are infected by the virus, then counting the number of areas in the culture which look infected. (09 Oct 1997) |
| focused grid | A grid in which the divergent beam of X-rays from a particular distance range will be parallel to the lead strips. (05 Mar 2000) |
| focusing device | <microscopy> A device which effectively increases the angular aperture of the electron beam illuminating the object, rendering the focus more critical. (05 Aug 1998) |
| focusing glass | <microscopy> A hand magnifier, used at the focal plane of a camera, usually with the ground glass removed. Its purpose is to examine the image for critical focus. It is, as a rule, a low-power magnifier so mounted that it is in focus when supported on a piece of clear glass at the focal plane of the cam- era, for studying the image. It operates equally well on the aerial image. (05 Aug 1998) |