(n.) A white, bitter, crystallizable substance, obtained from coffee. It is identical with the alkaloid theine from tea leaves, and with guaranine from guarana.
Example Sentences:
(1) Blood was collected from pups and dams to determine its caffeine concentration.
(2) When caffeine evokes a contraction, and only then, crayfish muscle fibers become refractory to a second challenge with caffeine for up to 20 min in the standard saline (5 mM K(o)).
(3) As expected, chronic administration led to complete tolerance to caffeine's locomotor stimulant effect, while subchronic administration produced sensitization.
(4) Caffeine and 6-methylaminopurine riboside (6-N-methyladenosine differentially inhibit uptake of radioactivity from adenosine and inosine, and thus the vesicles apparently possess seperate transport systems for uptake of radioactivity from purine nucleosides and from uridine.
(5) The inositol 1,4,5-trisphosphate (IP3) binding inhibitor, heparin, has no effect on ryanodine binding, and ryanodine and caffeine do not influence the binding of [3H]IP3, which is enriched in the cerebellar fractions.
(6) Post-labeling addition of 1 mM caffeine increased perpetuated blocks to a frequency of about 10% of the initial number of dimers in 4 h in XP16KO-II cells, but not in XP16KO-I and normal cells.
(7) Thus, in human lymphocytes the frequencies of chromatid aberrations induced by most clastogenic agents were strongly enhanced when caffeine was given during the G2 phase, but little affected by post-treatments with caffeine during the S phase.
(8) The Na(+)-induced Ca++ release from the sarcolemmal vesicles was stimulated with caffeine in a concentration-dependent manner; about 80% increase in the activity was observed at 0.1 mM caffeine.
(9) All other dietary constituents, such as protein, fiber, fluid, minerals (including Ca, Mg, Na, K, and P), and caffeine intake, were kept constant.
(10) All calcium, magnesium, and zinc contents per bone decreased in the 1- and 2-mg caffeine groups as compared to either controls or 0.5-mg caffeine group, whereas phosphorus stayed relatively constant regardless of the different levels of caffeine intake.
(11) In the presence of agents that inhibit sarcoplasmic reticulum (SR) function (10 mM caffeine, 100-500 nM ryanodine), reduction of the [Na] gradient produced increases in contractile force similar to that observed in the absence of caffeine or ryanodine.
(12) On the basis of these findings, it is suggested that screening for malignant hyperpyrexia by in vitro pharmacological testing of skeletal muscle should be carried out at 37 degrees C, and should include exposure of the sample to halothane, caffeine, suxamethonium and potassium rather than to halothane alone.
(13) The mechanism responsible for the potentiated anti-inflammatory and mild analgesic activity of aspirin remains unknown since caffeine did not alter the plasma salicylate levels or prostaglandin synthetase inhibition produced by aspirin.
(14) Their pups continued to consume the caffeine diet until 50 days.
(15) The pups were divided into caffeine and noncaffeine groups.
(16) In this study, eight patients participated in a standardized protocol to assess the effects of caffeine on seizures in ECT.
(17) These patients may have an increased risk of cardiovascular and cerebral excitation associated with higher concentrations of caffeine, which could complicate withdrawal from alcohol.
(18) were elevated significantly (P less than 0.05 at 0.3, 0.6 and 1 h after injection) when caffeine 5 or 10 mg kg-1 i.v.
(19) This study supports the findings of others in that caffeine restriction is an effective means of management of breast pain associated with fibrocystic disease.
(20) Aminophylline and caffeine can mimic this effect; however, papaverine and 1-methyl-3-isobutylxanthine, at concentrations inhibitory to phosphodiesterase, are without effect on glucocorticoid receptor binding to DNA.
Venom
Definition:
(n.) Matter fatal or injurious to life; poison; particularly, the poisonous, the poisonous matter which certain animals, such as serpents, scorpions, bees, etc., secrete in a state of health, and communicate by thing or stinging.
(1) Addition of phospholipase A2 from Vipera russelli venom led to a significant increase in the activity of guanylate cyclase in various rat organs.
(2) Four new monochain phospholipases were purified from the Oxyuranus scutellatus (taipan) venom.
(3) The antibodies were used for identifying cross-reacting proteins in individual C. s. scutulatus and other Crotalus venoms and to isolate Mojave toxin.
(4) Analysis of the product by equilibrium density centrifugation and processive hydrolysis with snake venom phosphodiesterase suggested that the noncomplementary nucleotides were present in phosphodiester linkage.
(5) The structure of the oligonucleotide-adenylate was determined by enzymatic digestion with base-nonspecific nuclease and venom phosphodiesterase.
(6) Admission venom levels also correlated with the extent of local swelling and the occurrence of tissue necrosis at the site of the bite.
(7) omega-Conotoxin GVIA is a peptide purified from the venom of the marine snail, Conus geographus, that specifically blocks voltage-sensitive calcium channels in neurons.
(8) The potential use of ancrod, a purified isolate from the venom of the Malaysian pit viper, Agkistrodon rhodostoma, in decreasing the frequency of cyclic flow variations in severely stenosed canine coronary arteries and causing thrombolysis of an acute coronary thrombus induced by a copper coil was evaluated.
(9) We developed a continuous spectrophotometric assay of the phospholipase A2 activity specific for choline plasmalogen using rat liver lysoplasmalogenase and horse liver alcohol dehydrogenase as coupling enzymes and Naja naja venom phospholipase A2 as a source of the phospholipase A2 activity.
(10) Two polypeptides (protein S5C1 and toxin S5C10) were purified from Dendroaspis jamesoni kaimosae venom.
(11) Weighed amounts of lyophilized venom from each snake were compared chronologically for variation in isoelectric focusing patterns, using natural and immobilized gradients.
(12) The presence of proteins antigenically related to Bothrops asper myotoxins in various snake venoms, mainly from South America, was investigated by using polyclonal and monoclonal antibodies.
(13) Phospholipase A2 from cobra venom (Naja naja naja) is a homogeneous, heat-stable enzyme that has a monomer molecular weight of only 11,000 and contains one histidine and one tryptophan residue.
(14) Surprisingly, whole-rat envenomation, using very large doses of venom, produced little dye leakage even though obvious symptoms of neurotoxic action were observed.
(15) Most double-helical segments were reactive to cobra venom ribonuclease to some degree; the exceptions were the five "long-range" helices that are probably compactly folded within the structure.
(16) Phospholipase A2 has been purified from the venom of Horned viper (Cerastes cerastes) by gel permeation chromatography followed by reverse-phase HPLC.
(17) Protamine sulphate in vitro antagonized anticoagulant properties but did not protect mice from toxic envenomation; because venom was also neurotoxic and showed a curare like effect at the neuromuscular junction.
(18) Only the enzyme from Naja naja naja (cobra) venom was found to be activated significantly by phosphorylcholine-containing compounds when hydrolyzing phosphatidylethanolamine.
(19) Factor X activator of Vipera russelli venom and esterase of T. mucrosquamatus venom did not have any effect on prothrombin.
(20) IgE antibodies from patients allergic to Vespula usually cross-react with V. crabro venom.