(a.) Having two units of combining power; bivalent. Cf. Valence.
Example Sentences:
(1) Binding is inhibited by divalent and trivalent cations (Cd2+ and La3+ being most potent) and other calcium channel drugs (1,4 dihydropyridines, phenylalkylamines, benzothiazepines).
(2) Although GTP most potently inhibited [125I]beta h-endorphin binding in the presence of sodium, inhibition of [125I]beta h-endorphin binding by GTP was also observed in the presence of the monovalent cations lithium and potassium, but not the divalent cations magnesium, calcium, or manganese.
(3) When the concentration of Ca2+ in the medium was raised to 10 mM was the only extracellular divalent cation present, the depolarization in response to A23187 was increased to 11-8 mV.
(4) Protons and divalent cations show synergistic effects on the destabilization of liposomes composed of unsaturated phosphatidylethanolamine and oleic acid (Düzgünes et al., Biochemistry (1985) 24, 3091).
(5) The enzyme is active over a wide range of pH, does not require divalent cations, and is inhibited by sulfhydryl-reactive agents.
(6) In order to determine the specific action of cadmium on bone metabolism, the effect of cadmium on alkaline phosphatase activity, a marker enzyme of osteoblasts, was compared with that of other divalent heavy metal ions, i.e., zinc, manganese, lead, copper, nickel and mercury (10 microM each), using cloned osteoblast-like cells, MC3T3-E1.
(7) The sensitivity to ionic strength, divalent metal ions and polylysine of release of fluorescent markers from liposomes and of haemoglobin from intact erythrocytes has been assayed.
(8) The enzyme is quite thermoresistant in the presence of other proteins, has an optimal temperature of 60 degrees, needs monovalent cations for optimal activity, is insensitive to EDTA, and is inhibited by divalent cations; it has no associated exonuclease activity.
(9) preference of template primer and divalent metal ion, RNA- or DNA-dependent DNA polymerase activity, RNase H activity, and the processive mode of DNA synthesis.
(10) It can be dissociated from the spores using divalent metal chelators and will reassemble on the spores in the presence of calcium.
(11) The presence of Ca2+ in silica gel is responsible for this improved yield of prostaglandin as the divalent metal ion stabilized prostaglandin synthetase activity in a remarkable way.
(12) In view of the above findings, it was hypothesized that polyamines in general took the place of divalent cations in causing membrane stabilization.
(13) The effects of monovalent and divalent cations on the hemolytic activity of Cerebratulus lacteus toxin A-III were studied.
(14) Other divalent metal ions displace Mn2+ from the high affinity sites in the following order of effectiveness: Ca greater than Mg = Zn = Co greater than Sr greater than Ni.
(15) Parameters observed were divalent association rate constants, affinity and autoradiography of isoelectric focusing (IEF) spectra.
(16) At low concentrations, the current-voltage relations are inwardly rectifying, but they become more ohmic if a small amount of divalent cations is added externally.
(17) Divalent cations (2 mM-Ni2+, 1 mM-Ba2+ or 2 mM-Ca2+) reduced only the outward current in the Tris Na(+)-free solution, while in the 150 mM-Na+ solution, they reduced both the inward and outward components of the current which had a reversal potential of around -10 mV.
(18) Cs (IC50 = 5-6 mM) prevented toxin binding, as did the divalent cations Ba and Ca (IC50 = 4-6 and 9-13 mM, respectively).
(19) Similar results were obtained in studies with the intact divalent radiolabelled Leu3a antibody.
(20) After renaturation of polypeptides, the gel was incubated with [gamma-32P]ATP and divalent cations.
Peroxide
Definition:
(n.) An oxide containing more oxygen than some other oxide of the same element. Formerly peroxides were regarded as the highest oxides. Cf. Per-, 2.
Example Sentences:
(1) The hypothesis that proteins are critical targets in free radical mediated cytolysis was tested using U937 mononuclear phagocytes as targets and iron together with hydrogen peroxide to generate radicals.
(2) The data indicate that ebselen is likely to be useful in the therapy of inflammatory conditions in which reactive oxygen species, such as peroxides, play an aetiological role.
(3) Furthermore, high-density catalase-positive--but not catalase-negative--E. coli can survive and multiply in the presence of competitive, peroxide-generating streptococci.
(4) Studies were conducted in isolated, buffer-perfused rat lungs to determine if prostaglandin (PG) E1 attenuated pulmonary edema provoked by hydrogen peroxide (H2O2).
(5) Spontaneous lipid peroxidation in washed human spermatozoa was induced by aerobic incubation at 32 C and measured by malonaldehyde production; loss of motility during the incubation was determined simultaneously.
(6) Changes in the plasma lipid composition are observed in patients and animals with malignancy and certain other diseases that are consistent with peroxidation of plasma lipoprotein lipids.
(7) Phenobarbital pretreatment increased peroxidation due to exposure of the cells to CCl4 but not that associated with NADPH addition.
(8) Both fatty acid composition and the degree of lipid peroxidation were measured in this study in 23 OTC fish oil preparations.
(9) With the use of two methods, measurement of conjugated dienes and thiobarbituric acid reactivity, brain lipid peroxidation could be documented as a result of exposure to CO at a concentration sufficient to cause unconsciousness.
(10) In the cytochrome P-450-reconstituted system, CCl4 stimulated NADPH-dependent lipid peroxidation of the system containing the P-450 form to a much greater extent than that of the system containing the P-448 form.
(11) The in vivo hepatic lipid peroxide content of rats was increased by aspirin or 4-pentenoic acid (4-PA) administration but was decreased by clofibrate (CPIB) administration.
(12) A water based 5% benzoyl peroxide gel (Benzac W5) was compared with topical 1% clindamycin phosphate solution (Cleocin T) in the treatment of acne vulgaris using a randomized, investigator blind study design.
(13) M & B 22948, a guanosine 3',5'-cyclic monophosphate (cGMP)-selective phosphodiesterase inhibitor, enhanced the vasodilation or relaxation to the peroxide in both preparations.
(14) Accordingly, the 30-fold differences in aging rate among the mammalian species could be determined in part by peroxidation defense processes.
(15) Hence, the 2-NOF:N-acetoxy-N-2-fluorenylacetamide ratios reflect the relative contributions of the two peroxidative pathways to the metabolism of N-OH-2-FAA.
(16) Vanadate-dependent oxidation of either pyridine nucleotide was inhibited by the addition of either superoxide dismutase or catalase, indicating that both superoxide and hydrogen peroxide may be intermediates in the process.
(17) Compared with 39 control subjects, 39 antioxidant-supplemented men experienced the following net reductions during the double-blind period: 20% (P = 0.012) in serum lipid peroxides, 24% (P = 0.035) in ADP-induced platelet aggregation, 42% (P = 0.040) in the rate of ATP release during aggregation, 51% (P = 0.018) in serum (platelet-produced) thromboxane B2, and 29% (P = 0.024) in plasma beta-thromboglobulin concentration.
(18) Protection against O2 toxicity was assessed in terms of lethality and pulmonary edema and of lung lipid peroxidation (assessed by measuring malondialdehyde).
(19) Serum GSSRase activity, however, was significantly decreased while serum vitamin E, and lipid peroxidation levels were significantly increased.
(20) From these results it is suggested that the lipid peroxidation of the brush-border membranes by addition of dithiothreitol plus Fe2+ is sensitively changed with change in ionic strength.