(n.) An elementary substance; a metal which combined with oxygen forms lime. It is of a pale yellow color, tenacious, and malleable. It is a member of the alkaline earth group of elements. Atomic weight 40. Symbol Ca.
Example Sentences:
(1) In studies of calcium metabolism in 13 unselected patients with untreated sarcoidosis all were normocalcaemic but five had hypercalcuria.
(2) After stimulation with lipopolysaccharide and calcium ionophore A23187, culture supernatants of clones c18A and c29A showed cytotoxic activity against human melanoma A375 Met-Mix and other cell lines which were resistant to the tumor necrosis factor, lymphotoxin and interleukin 1.
(3) The half-life of 45Ca in the various calcium fractions of both types of bone was 72 hours in both the control and malnourished groups except the calcium complex portion of the long bone of the control group, which was about 100 hours.
(4) Calcium alginate dressings have been used in the treatment of pressure ulcers and leg ulcers.
(5) of PLA2 caused marked degranulation of mast cells in the rat mesentery which was facilitated by addition of calcium ion (10 mM) but antagonized by pretreating with three antiinflammatory agents.
(6) Thus adrenaline, via pre- and post-junctional adrenoceptors, may contribute to enhanced vascular smooth muscle contraction, which most likely is sensitized by the elevated intracellular calcium concentration.
(7) It includes preincubation of diluted plasma with ellagic acid and phospholipids and a starting reagent that contains calcium and a chromogenic peptide substrate for thrombin, Tos-Gly-Pro-Arg-pNA.
(8) The results show that endolymph is extremely inhomogenous with respect to calcium potentials.
(9) The occupation of the high affinity calcium binding site by Ca(II) and Mn(II) does not influence the Cu(II) binding process, suggesting that there is no direct interaction between this site and the Cu(II) binding sites.
(10) This was unlike the action of the calcium channel blocker, cadmium, which reduced the calcium action potential and the a.h.p.
(11) Increases in extracellular calcium antagonized the negative inotropic effect.
(12) Plasma membranes were isolated from rat kidney and their transport properties for sodium, calcium, protons, phosphate, glucose, lactate, and phenylalanine were investigated.
(13) In experiments performed to determine whether PtdIns(4,5)P2 hydrolysis induced by TRH may have been caused by the elevation of [Ca2+]i, the following results were obtained: the effect of TRH to decrease the level of PtdIns(4,5)P2 was not reproduced by the calcium ionophore A23187 or by membrane depolarization with 50 mM K+; the calcium antagonist TMB-8 did not inhibit the TRH-induced decrease in PtdIns(4,5)P2; and, most importantly, inhibition by EGTA of the elevation of [Ca2+]i did not inhibit the TRH-induced decrease in PtdIns(4,5)P2.
(14) The distribution of gelsolin, a calcium-dependent actin-severing and capping protein, in the retina of the developing and adult rabbit was studied.
(15) In K+-depolarized basilar arteries, ifenprodil competitively antagonized the response to Ca2+, and this was enhanced by pre-incubation in calcium hopantenate.
(16) Thirty of the 32 women of the calcitonin group and 27 of 28 women of the calcium group finished treatment.
(17) The influence of calcium ions on the electrophoretic properties of phospholipid stabilized emulsions containing various quantities of the sodium salts of oleic acid (SO), phosphatidic acid (SPA), phosphatidylinositol (SPI), and phosphatidylserine (SPS) was examined.
(18) Hypercalcitoninemia was the most pronounced in patients with cardiac rhythm disorders and a simultaneous reduction in total serum calcium.
(19) The effects of low doses of dihydropyridine (DHP) calcium channel antagonists nimodipine, nifedipine, (-)-R-202-791, and amlodipine, the DHP calcium channel agonist BAY K 8644 were investigated on clonic convulsions to pentylenetetrazole (PTZ) in mice.
(20) A comprehensive review of the roentgenographic features of calcium pyrophosphate crystal deposition disease (pseudogout) is presented.
Strontium
Definition:
(n.) A metallic element of the calcium group, always naturally occurring combined, as in the minerals strontianite, celestite, etc. It is isolated as a yellowish metal, somewhat malleable but harder than calcium. It is chiefly employed (as in the nitrate) to color pyrotechnic flames red. Symbol Sr. Atomic weight 87.3.
(n.) A radioactive isotope of strontium produced by certain nuclear reactions, and constituting one of the prominent harmful components of radioactive fallout from nuclear explosions; also called radiostrontium. It has a half-life of 28 years.
Example Sentences:
(1) Specimens of human bone from the site exhibited lower strontium levels and strontium-to-calcium ratios than deer specimens from the same site, reinforcing paleodemographic evidence that the human populations that inhabited this site included substantial amounts of meat in their diets.
(2) Revascularisation was evaluated with radioactive microspheres; formation of new bone was assessed by incorporation of strontium, and resorption was assessed by measuring the reduction of graft weight.
(3) Compared with the transected control group, resection decreased strontium absorption per unit weight of mucosa (specific absorption) in the proximal segment.
(4) Human spermatozoa incubated in a strontium- or lanthanum-based medium, or T6 + 10% maternal human serum (HS) supplemented with 12 mM 8-bromo cyclic guanosine 3,5'-monophosphate and 10 mM imidazole for a 4-hour period before transfer to fresh T6 + 10% HS for a further 6 hours, demonstrated a significant increase (P less than 0.05) in acrosomal loss compared with T6 + 10% HS for a total 10-hour incubation.
(5) Concentration factors of strontium-90 in aquatic organisms and substrates are higher in a dystrophic lake than in the other types.
(6) In the absence of calcium, other divalent cations such as magnesium, strontium, or manganese were not efficient substitutes for calcium.
(7) A similar effect was obtained by strontium, but magnesium was ineffective.4.
(8) The predicted fallout of strontium-90 in 1970 is less than 1 percent of that during the peak year 1963.
(9) The decontamination of strontium was checked by applying non-dispersive fluorescence X-ray analysis using 133Ba as irradiating source.
(10) Strontium ions, added to a calcium-deficient bathing solution, were shown to attenuate the increased 45Ca uptake by the lens.
(11) Results are presented to show that calcium and strontium act at the same site but strontium is a more sensitive probe for that site.
(12) The elements added to increase radiopacity in the composite materials are barium, strontium, zinc, zirconium, and ytterbium.
(13) Heat-induced release of dipicolinic acid occurred much faster with barium and strontium spores than with calcium spores.
(14) Annual dose rates of 27 millirads to bone and 4 millirads to the whole body correspond to the highest average concentrations of strontium-90 and cesium-137 so far observed.
(15) Strontium (2.5 mM) significantly attenuated the response to CCK-OP and bethanechol, but not to KCl.
(16) Strontium can replace calcium in a number of physiological and biochemical processes.
(17) A high percentage of the strontium retained during both oral and intravenous administration was excreted in 30 days after the discontinuation of the strontium administration and there was no evidence of long term retention.
(18) Enhanced HR with strontium was greater with basophils from normal subjects than from subjects with allergic rhinitis.
(19) In vascular smooth muscle that does not contract spontaneously, similar deposits of strontium were only seen if the muscle was depolarized during or glycerinated before exposure to the strontium-containing solution.
(20) The results of a study of 975 pterygia treated surgically and immediately with Strontium 90 are presented.