(n.) The regular form which a substance tends to assume in solidifying, through the inherent power of cohesive attraction. It is bounded by plane surfaces, symmetrically arranged, and each species of crystal has fixed axial ratios. See Crystallization.
(n.) The material of quartz, in crystallization transparent or nearly so, and either colorless or slightly tinged with gray, or the like; -- called also rock crystal. Ornamental vessels are made of it. Cf. Smoky quartz, Pebble; also Brazilian pebble, under Brazilian.
(n.) A species of glass, more perfect in its composition and manufacture than common glass, and often cut into ornamental forms. See Flint glass.
(n.) The glass over the dial of a watch case.
(n.) Anything resembling crystal, as clear water, etc.
(1) Such a signal must be due to a small ferromagnetic crystal formed when the nerve is subjected to pressure, such as that due to mechanical injury.
(2) A comprehensive review of the roentgenographic features of calcium pyrophosphate crystal deposition disease (pseudogout) is presented.
(3) CW Nd:YAG light transmitted by fiber optic cable and sapphire crystal was applied transsclerally to the ciliary body of pigmented and albino rabbits.
(4) The crystal structure of the biological stain, "acridine orange," has been determined.
(5) Urinalysis revealed a low pH, increased ketones and bilirubin excretion, dark yellowish change in color, the appearance of "leaflet-shaped" crystals and increased red blood cells and epithelial cells in the urinary sediment, increased water intake, decreased specific gravity and decreased sodium, potassium and chloride in the urine.
(6) Early in the regression process, cholesterol esters are reduced at least partly by hydrolysis to yield cholesterol, some of which may crystallize and inhibit rapid regression.
(7) Here we determine the position of bound ADP diffused into the recA crystal.
(8) The virus material in these crystals had been subjected to treatment with EDTA at pH 8.0 before crystallization at pH 6.5.
(9) Results obtained show that chlorophyll is more active than other inhibitors studied and suggest a higher surface adsorption intensity on the primary sources of the crystal surface.
(10) The "Mg(2+)-Sarkosyl crystals" (M band) technique distinguishes between membrane-bound and free intracellular DNA.
(11) The molecular structure of the hexagonal crystal form of porcine pepsin (EC 3.4.23.1), an aspartic proteinase from the gastric mucosa, has been determined by molecular replacement using the fungal enzyme, penicillopepsin (EC 3.4.23.6), as the search model.
(12) In vitro experiments show that these macromolecules are able to interact with specific faces of different crystals, influencing both nucleation and crystal growth.
(13) 2 Each of the drugs significantly increased leucocyte cyclic AMP content within 3 h of the injection of crystals.
(14) For Kevin Phillips, just like Wilfried Zaha, this might have been his final act as a Crystal Palace player.
(15) In ancillary studies, multiple cycles of direct dissolution of UCB crystals revealed a progressive decrease in aqueous solubility of UCB as fine crystals were removed; this effect was minimal in CHCl3.
(16) Six dogs were instrumented with electromagnetic flow probes and subendocardial ultrasonic crystals.
(17) The crystallization of the lipase was successfully carried out.
(18) The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution.
(19) The crystal structure of proteolytically modified human ACT has been solved at 2.7-A resolution (Baumann et al., 1991).
(20) These observations support our hypothesis that calcium pyrophosphate dihydrate crystal deposition in joints is regulated by the physical chemical gel state of the connective tissue matrix.
Tophus
Definition:
(n.) One of the mineral concretions about the joints, and in other situations, occurring chiefly in gouty persons. They consist usually of urate of sodium; when occurring in the internal organs they are also composed of phosphate of calcium.
(n.) Calcareous tufa.
Example Sentences:
(1) Seven-to-14-week-old pullets from this facility had multifocal renal tubular necrosis leading to interstitial fibrosis, tophus formation, and tubular dilation.
(2) A rare case of gouty tophus localized to the temporomandibular joint is reported on by which alimentary troubles were caused.
(3) After 1 month, the kidneys showed the previously described histologic features of urate-blockade nephropathy characterized by intratubular deposits, tubular injury, and an exudative response consisting of neutrophilic granulocytes with early tophus formation.
(4) The authors report a rare case of tophus situated in the optic nerve and coexisting with aneurysm of the anterior communicating artery.
(5) We describe an elderly woman presenting acutely with tophus formation mimicking infection, in whom diuretic therapy was responsible for her disease.
(6) Almost all the sites of tophus-like deposits of CPPD crystals and the degenerated matrix containing low concentrations of scattered CPPD crystals stained strongly with Sudan III.
(7) In the gout tophus, macrophage migration appears to be at a relatively low level and effectively terminates once these cells have been recruited into the corona.
(8) Tophus formation at the temporomandibular joint with extension into the fossa infratemporalis has been mentioned only three times in the world literature.
(9) A case of extradural gouty tophus in the lumbar region in a teen-age girl is presented as an addition to the differential diagnosis of erosive lesions of the spinal canal.
(10) Both tophus-derived and synthetic crystals appeared to be weak hemolytic agents.
(11) Endoscopic biopsy revealed a tophus of the true vocal cord with characteristic birefringent crystalline deposits and giant cell granuloma.
(12) Monosodium urate monohydrate (MSUM) crystals derived from a tophus surgically removed from patients suffering from gout and MSUM prepared from a supersaturated solution of sodium urate were studied and compared with respect to their ability to: (1) stimulate chemiluminescence (CL) production by human polymorphonuclear (PMN) cells, (2) induce hemolysis of the human red blood cells and (3) induce inflammation when injected in the rat paw and knee joint.
(13) -In the present paper, the authors report on the extraordinary location of an urate tophus in the fossa infratemporalis - in this case, there was even destruction of the middle base of the skull - which had been misinterpreted for years, having been diagnosed as a primary disease of the parotid gland.
(14) A burn precipitated one bulla, showing that local tissue injury can be a factor in tophus localization.
(15) Subcutaneous cholesterol crystal deposition with tophus formation is extremely rare and has been described in a patient with scleroderma and calcinosis cutis.
(16) The findings suggest that acini of macrophages are formed and that active cellular transport of urate from the interstitial fluid into the central zones of these structures accounts for the focal nature of crystallization within the tophus.
(17) A typical gouty tophus with birefringent, dichroic, needle shaped crystals was found in a resected calcified aortic valve on routine histological examination.
(18) Fresh tophaceous material from a patient with gout contained significant levels of TNF alpha and cells cultured from the tophus produced TNF alpha in vitro.
(19) Evidence of an axial skeletal tophus causing an irritative radiculopathy via mass effect is presented.
(20) Each of those formulations of a pathogenetic role for crystals may be true in a given case, analogous to the etiology of primary and secondary forms of hyperuricemia and to sodium urate crystal deposition coexistent with osteoarthritis (tophus formation in Heberden's nodes).