|Medical Dictionary - Dictionary of Medicine and Human Biology|
σ, upper case Σ
The compound formed by the demethylation of S-adenosyl-l-methionine.
S-adenosyl-l-methionine (SAM, AdoMet) (a-den′o-sil-me-thi′o-nen)
Condensation product of adenosine and l-methionine involving replacement of the &cbond;OPO3H2 of adenylic acid by &cbond;S+(CH3)CH2CH2CH(NH3+)CO2 of methionine; a sulfonium compound bearing a methyl group that is transferred in transmethylation reactions. SEE ALSO: methionine adenosyltransferase, aka active methionine.
A compound formed by the binding of nitric oxide with hemoglobin; release and uptake of the nitric oxide group produce changes in vascular resistance and blood flow, which assist in oxygen homeostasis.
An acidic, calcium-binding protein characterized by its partial solubility in saturated ammonium sulfate; stains for S. are used in the differential diagnosis of melanomas, which are commonly positive for S..
Symbol for sulfur-35.
Symbol for first heart sound.
Symbol for entropy.
Symbol for second heart sound.
Symbol for third heart sound.
Symbol for fourth heart sound.
SYN: summation gallop.
Symbol for flotation constant.
Abbreviation of L. sinister, left; L. semis, half; second; as a subscript, denotes steady state.
Abbreviation for L. sine, without.
Abbreviation for sinuatrial.
Abbreviation for sacroanterior position.
The seed of Schoenocaulon officinale (family Liliaceae), a plant of the shores of the Gulf of Mexico and Caribbean Sea; it yields cevadine, veratridine, and several other alkaloids; has been used externally as a parasiticide. SYN: cevadilla. [Sp. cevadilla, ult. fr. L. cibus, food]
Albert B., Polish-U.S. virologist, 1906–1993. See S. vaccine, S.-Feldman dye test.
Raymond J.A., French dermatologist, 1864–1938. See S. agar, S. pastils, under pastil, S.-Noiré instrument.
Sandy; gritty. [L. sabulosus, fr. sabulum, coarse sand]
Foulness of the stomach or mouth resulting from decomposed food. [L. sand]
Relating to saburra.
Rapid eye movement to redirect the line of sight. [Fr. s., sudden check of a horse]
Jerky. See s. movement.
Relating to a sac. [L. saccus, sac]
A salt or ester of saccharic acid.
The presence of sugar in the sweat. [sacchar- + G. ephidrosis, a slight perspiration]
Relating to sugar.
saccharic acid (sak′a-rik)
Term used to denote the class of dicarboxy sugar acids.
S. are classified as mono-, di-, tri-, and polysaccharides according to the number of monosaccharide groups composing them. See carbohydrates.
The process of saccharifying.
To convert starch or cellulose or other polysaccharides into sugar. [sacchari- + L. facio, to make]
An instrument for determining the amount of sugar in a solution; it may be a polarimeter, a hygrometer, or a container in which the solution is fermented and the amount estimated by the volume of CO2 produced. SYN: saccharometer. [(sacchari- + G. metron, measure]
In dilute aqueous solution it is 300–500 times sweeter than sucrose; used as a noncaloric sweetening agent (sugar substitute); s. sodium and s. calcium have the same use. SYN: benzosulfimide.
saccharine (sak′a-ren, -rin, -rin)
Relating to sugar; sweet.
saccharo-, sacchar-, sacchari-
Combining forms denoting sugar (saccharide). [G. sakcharon, sugar]
saccharogen amylase (sak′a-ro-jen)
Capable of hydrolyzing or otherwise breaking down a sugar molecule. [saccharo- + G. lysis, loosening]
Relating to saccharometabolism.
Metabolism of sugar; the process of utilization of sugar in cells.
A genus of budding yeasts (family Saccharomycetaceae); an ascomycete. S. cerevisiae is used to produce brewer's yeast and ethanol. S. cerevisiae is a very rare pathogen in humans. [saccharo- + G. mykes, fungus]
The family of yeasts; that group of fungi comprising the ascomycetes which possess a predominantly unicellular thallus, reproduce asexually by budding, transverse division, or both, and produce ascospores in an ascus, originating from a zygote or pathogenetically from a single somatic cell. The term yeastlike fungus is often applied to fungi that are not known to form ascospores, but otherwise possess the characteristics of yeasts; such forms are properly placed with the Fungi Imperfecti unless methods of sexual reproduction are known; e.g., Cryptococcus neoformans.
A derivative of α-ketoglutarate and l-lysine that is an intermediate in l-lysine catabolism; elevated in cases of saccharopinuria. s. dehydrogenase two enzymes that are used in the pathway of l-lysine catabolism; the first isoform catalyzes the reversible conversion of l-lysine, α-ketoglutarate, and NADH to s. and NAD+; the other isoform reversibly catalyzes to conversion of s. and NAD+ to l-glutamate, NADH, and l-α-aminoadipate δ-semialdehyde. A deficiency of one of these isoforms is associated with familial hyperlysinemia and saccharopinuria.
Elevated levels of saccharopine in the urine; associated with a variant of familial hyperlysinuria.
SYN: sucrose. [Mod. L. fr. G. sakcharon] s. canadense SYN: maple sugar. s. lactis SYN: lactose.
Pouched; sac-shaped. SYN: saccular, sacculated. [L. saccus, sack, + forma, form]
1. A structure formed by a group of sacs. 2. The formation of a sac or pouch. s. of colon SYN: haustra of colon, under haustrum.
1. [TA] The smaller of the two membranous sacs in the vestibule of the labyrinth, lying in the spherical recess; it is connected with the cochlear duct by a very short tube, the ductus reuniens, and with the utriculus by the beginning of the ductus endolymphaticus and the ductus utriculosaccularis that joins it. 2. The immense bag-shaped structure formed by peptidoglycans as part of the cell wall of certain microorganisms. SYN: sacculus [TA] , sacculus proprius, sacculus vestibuli. [L. sacculus] laryngeal s. [TA] a small diverticulum provided with mucous glands extending upward from the ventricle of the larynx between the vestibular fold and the lamina of the thyroid cartilage; it is a vestigial structure, being a much larger structure interdigitating with the neck musculature in some of the great apes, where it serves as a resonating chamber. SYN: sacculus laryngis [TA] , appendix ventriculi laryngis, Hilton sac, laryngeal pouch, s. of larynx. s. of larynx SYN: laryngeal s..
Relating to the sacculus and the membranous cochlea.
sacculus, pl .sacculi (sak′u-lus, -li) [TA]
SYN: saccule. [L. dim. of saccus, sac] s. alveolaris, pl .sacculi alveolares [TA] SYN: alveolar sac (1) . s. communis SYN: utricle. s. endolymphaticus SYN: endolymphatic sac. s. lacrimalis SYN: lacrimal sac. s. laryngis [TA] SYN: laryngeal saccule. s. proprius SYN: saccule. s. vestibuli SYN: saccule.
saccus, pl .sacci (sak′us, sak′si) [TA]
SYN: sac (1) . [L. a bag, sack] s. conjunctivalis [TA] SYN: conjunctival sac. s. endolymphaticus [TA] SYN: endolymphatic sac. s. lacrimalis [TA] SYN: lacrimal sac. s. reuniens SYN: sinus venosus. s. vaginalis an embryonic peritoneal fossa indicating the site where the processus vaginalis peritonei extends through the anterior abdominal wall during descent of the testis.
Bernard, U.S. neurologist, 1858–1944. See Tay-S. disease.
Hans, German bacteriologist, 1877–1945. See S.-Georgi test.
Maurice D., U.S. radiologist, *1909. See Hill-S. lesion.
Benjamin, U.S. physician, 1896–1939. See Libman-S. endocarditis, Libman-S. syndrome.
In the direction of the sacrum. [sacr- + L. ad, to]
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