(n.) A rare metallic element of the aluminium group found in some minerals, as certain pyrites, and also in the lead-chamber deposit in the manufacture of sulphuric acid. It is isolated as a heavy, soft, bluish white metal, easily oxidized in moist air, but preserved by keeping under water. Symbol Tl. Atomic weight 203.7.
Example Sentences:
(1) Thallium-201, a radiopharmaceutical that possesses many of the characteristics of potassium analogues, at present is receiving the greatest attention as a regional blood flow indicator.
(2) Distant ischemia was distinguished from peri-infarctional ischemia by the presence of transient thallium defects in, or slow thallium washout from myocardium not supplied by the infarct-related coronary artery.
(3) In 89 patients, a symptom-limited exercise electrocardiogram (ECG) and thallium scintigraphy were performed 4 weeks after they had undergone successful PTCA.
(4) The results of quantitative analysis of planar thallium-201 stress scintigraphy are superior to those of visual analysis.
(5) Qualitative planar 201-thallium (201Tl) scans, coronary angiography, or both were also performed (median between studies 11 days).
(6) Eight of 16 patients with thallium redistribution had cardiac events, whereas there were no such events in 32 patients whose thallium scan either was normal or showed only persistent defects (P less than 0.0001).
(7) A method of poisoning cats with thallium is described.
(8) Normal thallium uptake on single photon emission computed tomographic scintigraphy early in the hospital course predicted myocardial viability in the region of the aneurysm.
(9) Before surgery, 15 patients had myocardial perfusion defects during exercise that completely normalized at rest, one patient had both reversible and fixed perfusion defects, two patients had fixed defects only, and two patients had normal exercise and rest thallium scans.
(10) This analysis suggests that the reported sensitivity of thallium scintigraphy is higher and the specificity lower than that expected in clinical practice because of the presence of workup bias and the inappropriate inclusion of post-infarct patients.
(11) Thus, estimation of total % thallium uptake is a simple index which yields useful diagnostic clinical information.
(12) When combined with atrial pacing, 2-D echocardiography and thallium 201 perfusion imaging are of similar value for diagnosing the presence of CAD in patients with stable chest pain.
(13) We evaluated the role of thallium-201 single-photon emission-computed tomography (SPECT) in diagnosis, differential diagnosis and follow-up of 33 patients with primary brain tumors.
(14) By contrast, in 11 patients with no previous myocardial infarction and normal left ventricular function at rest (Subgroup B), initial uptake of both tracers was inverse: poststenotic N-13 glutamate uptake increased with decreasing thallium-201 uptake during exercise-induced ischemia (r = -0.64, p less than 0.05) and was closely correlated with the percent thallium-201 redistribution (r = 0.74, p less than 0.01).
(15) This subset of patients showed the least dynamic anterior wall contraction (P less than 0.001) and the highest incidence of thallium-201 perfusion defects (P less than 0.05) and of recurrent cardiac arrest (P less than 0.05).
(16) Thallium imaging was much more likely to be positive (p less than 0.01) in patients with a cardiac complication; however, there was a significant number of patients with cardiac complications who had a positive history or electrocardiogram for myocardial infarction.
(17) Intravenous dipyridamole-thallium imaging unmasks ischemia in patients unable to exercise adequately.
(18) Over a two year period, 67 patients undergoing carotid or aortic surgery were investigated preoperatively with dipyridamole-thallium scan.
(19) Morphometric analysis of hepatocytes from thallium-treated rats disclosed a 3-fold increase in the volume density of the lysosomal compartment and a 1.3-fold increase in the volume density of mitochondrial.
(20) Segmental analysis of the planar thallium-201 images was performed in a blinded fashion with agreement by consensus.
Thallous
Definition:
(a.) Of or pertaining to thallium; derived from, or containing, thallium; specifically, designating those compounds in which the element has a lower valence as contrasted with the thallic compounds.
Example Sentences:
(1) Overall, thallous chloride Tl 201 perfusion scanning had a sensitivity of 75% and a specificity of 91% for coronary heart disease compared with 56% sensitivity and 86% specificity with exercise-induced ST segment depression on the ECG.
(2) The change in distribution of cardiac output in septic shock was examined by radionuclide imaging with thallium 201 thallous chloride (201Tl) which allows noninvasive evaluation of relative blood flow to various organs except for the brain.
(3) Dual radionuclide imaging of the neck (Tc-99m pertechnetate and TI-201 thallous chloride) was performed in 22 patients with chemical evidence of hyperparathyroidism (elevated blood calcium and parathormone [PTH] levels).
(4) This study evaluated thallous chloride Tl 201 single-photon-emission computed tomography in a series of 48 patients following blunt chest trauma.
(5) The monovalent thallous ion (Tl) was evaluated at the frog end plate in vitro with intracellular microelectrodes.
(6) Twenty-nine patients with primary hyperparathyroidism underwent double-tracer subtraction scanning after injection of 201Tl as thallous chloride for thyroid and parathyroid images followed by 99mtechnetium as sodium pertechnetate for thyroid images prior to surgical exploration of the neck.
(7) The high lung activity and early myocardial redistribution within the 1st hour contributed to the failure of 99mTc-TBI to detect 16 segmental defects seen in the immediate post-exercise thallous chloride scan.
(8) The locus of thallium affection is assumed to be a mitochondrial membrane with a specific affinity to the thallous ion.
(9) A mixture (0.1 ml) of 201Tl+ (thallous+ chloride-) and 99mTc-pertechnetate- (Na+ pertechnetate-) was given, by which 99mTc-pertechnetate- served as a reference substance with negligible intracellular accumulation.
(10) Gentamicin-thallous-carbonate (GTC) medium contained (per liter): 40.0 g of Trypticase soy agar, 5.0 g of KH(2)PO(4), 2.0 g of NaHCO(2), 1.0 g of glucose, 1.0 g of esculin, 0.5 g of thallous acetate (TA), 0.5 g of ferric citrate, 0.75 ml of Tween 80, and 2.5 mg of gentamicin sulfate.
(11) The patients were imaged after sequential IV injection of 201Tl-thallous chloride (74 MBq) and 99mTc-pertechnetate (222 MBq) using a gamma camera with a pinhole collimator.
(12) In this article the author reviews the biologic characteristics, the imaging protocols and the clinical usefulness of thallous chloride Tl 201, 99mTc-sestamibi and 99mTc-teboroxime (not yet available in Canada), as well as their complementary roles in the detection of coronary artery disease.
(13) Optically pure (R)-(-)-m-trimethylacetoxy-alpha-[(methylamino)methyl]benzyl alcohol hydrochloride was synthesized by the following sequence: (R)-(-)-phenylephrine was condensed with acetone in the presence of calcium carbide to give an oxazolidine derivative and then treated with thallous ethoxide in ether followed by trimethylacetyl chloride to yield the phenolic ester.
(14) In addition, a thallous-azide combination at pH 6.5 was used successfully for the primary isolation of Str.
(15) We have since progressed to the fields of research involving pharmacological stress testing with intravenous dipyridamole and use of technetium-based isonitrile as an alternative to the conventional myocardial perfusion agent, thallous chloride.
(16) The properties of this channel in solutions which do not contain thallous ion are consistent with the predictions of Läuger's theory for singly occupied pores (P. Lüger, 1973, Biochim.
(17) Application of either divalent cations (cobalt, cadmium) or monovalent thallous ions to the bath, even in mM concentrations, did not change these waveforms significantly.
(18) Thallous acetate-citrate (TAC) agar, a selective medium for isolating enterococci from frozen foods, was evaluated.
(19) SR channel properties in the presence of thallous ion can, however, be explained by a model which postulates the existence of two external modulatory sites on the channel, without implying double-occupancy in the permeation pathway.
(20) Three days later these animals ran on a treadmill, and 201-thallous chloride was injected into the right atrium at peak exercise.