| Fischer projection formula | <biochemistry> Of sugars, representations, by projection, of cyclic sugars, or derivatives thereof, in which the carbon chain is depicted vertically. The lowest-numbered asymmetric carbon atom (C-1 in aldoses; C-2 in 2-ketoses, e.g., fructose) is drawn at the top, and the rest of the carbon atoms of the chain are drawn in sequence below the top carbon atom. For each carbon atom, depicted in projection as lying in the plane of the paper, the carbon-to-carbon bond(s), which actually point away from the viewer, are drawn as vertical lines. The left-hand and right-hand bonds of each carbon atom, which actually point toward the viewer, are, in projection, depicted as horizontal lines. The conventions for the Fischer formulas of cyclic sugars are as follows: 1) if the highest-numbered asymmetric carbon atom has its OH (or its replacement) lying to the right, as is the 2-OH of d-glyceraldehyde, the sugar has the d configuration; if the OH is to the left, the sugar has the l configuration. 2) On the anomeric carbon atom (C-1 in the aldoses; C-2 in the 2-ketoses), an OH or substituted OH that lies to the right, with the OH of the highest-numbered asymmetric carbon atom also to the right is defined to be a; if it is to the left, with the OH of the highest-numbered carbon atom still to the right, it is b; the reverse applies if the latter OH is to the left. 3) The orientation of a terminal CH2OH group in the aldoses carries no configurational significance, as it contains no asymmetric carbon atom. (05 Mar 2000) |
|---|---|
| Fischer's sign | <clinical sign> An obsolete sign: in tuberculosis of the mediastinal or peri-bronchial glands, after bending the patient's head as far back as possible, auscultation over the manubrium sterni will sometimes reveal a continuous loud murmur caused by the pressure of the enlarged glands on the large mediastinal vessels. Synonym: Fischer's symptom. (05 Mar 2000) |
| Fischer's symptom | <clinical sign> An obsolete sign: in tuberculosis of the mediastinal or peri-bronchial glands, after bending the patient's head as far back as possible, auscultation over the manubrium sterni will sometimes reveal a continuous loud murmur caused by the pressure of the enlarged glands on the large mediastinal vessels. Synonym: Fischer's symptom. (05 Mar 2000) |
| Fischer, Emil | <person> German chemist and Nobel laureate, 1852-1919. See: Fischer projection formulas of sugars, Kiliani-Fischer synthesis, Kiliani-Fischer reaction. (05 Mar 2000) |
| Fischer, Louis | <person> U.S. Paediatrician, 1864-1944. See: Fischer's sign, Fischer's symptom. (05 Mar 2000) |
| fisetic | <chemistry> Pertaining to fustet or fisetin. Source: Websters Dictionary (01 Mar 1998) |
| fisetin | <chemistry> A yellow crystalline substance extracted from fustet, and regarded as its essential colouring principle. Synonym: fisetic acid. Origin: G. Fisettholz a species of fustic. Source: Websters Dictionary (01 Mar 1998) |
| fish | A physical mappingapproach that uses fluorescent tags to detect hybridisation of probes with metaphasechromosomes and with the less-condensed somatic interphase chromatin. (09 Oct 1997) |
| FISH Analysis | <molecular biology, technique> Use of a DNA or RNA probe todetect the presence of the complementaryDNA sequence in cloned bacterial or cultured eukaryotic cells.Also used for locating geneson chromosomes. The process is: Prepare microscope slide with cells in metaphase of mitosis, Treat slide with a weak base. Thus denaturing the DNA. Pour radioactively labelled probe onto the slide. Expose slide to photographic emulsion for a few days or weeks. Develop emulsion. (13 Oct 1997) |
| fish berry | The seeds of Anamirta paniculata which contain the amaroid, picrotoxin; a CNS and respiratory stimulant, used in veterinary medicine as an antidote to barbiturates. Name derived from the use of bruised berries thrown into streams to poison or incapacitate fish. (05 Mar 2000) |
| fish bowl granuloma | Localised nodular skin inflammation (small reddish raised areas of skin) caused by a bacterium called mycobacterium marinum. Fish bowl granuloma is typically acquired by occupational or recreational exposure to salt or fresh water, often resulting from minor trauma during caring for aquariums. The diagnosis is suggested by the history of exposure and confirmed by culturing tissue specimens which yield the microscopic organism, mycobacterium marinum. The infection can be treated with a variety of antibiotics, including doxycycline, minocycline, clarithromycin, rifampin, and trimethoprim-sulfamethoxazole. Also called swimming pool granuloma. (12 Dec 1998) |
| fish diseases | Diseases of freshwater, marine, hatchery or aquarium fish. This term includes diseases of both teleosts (true fish) and elasmobranchs (sharks, rays and skates). (12 Dec 1998) |
| fish elevation | The elevation of a fish above the stream bed measured at the tip of the fish's snout. See: focal point. (09 Oct 1997) |
| fish eye disease | <disease> An inherited disorder resulting in low HDL cholesterol and corneal opacities; also, low LCAT activity. (05 Mar 2000) |
| fish flour | A flour made of pulverised, dried fish or fish parts. (12 Dec 1998) |