(1) A new type of Escherichia coli mutant which shows increased sensitivity to methyl methane sulfonate but not to UV light or to gamma rays was isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine.
(2) Sec-alpha-halo-nitro compounds are active antibacterial and antifungal agents, and the sec-bromo derivatives are the most active and stable.
(3) A series of 2-styryl-5-nitro-1-vinylimidazoles carrying alkylaminomethyl or amidino functions in the 4 position of the styryl ring was prepared and evaluated for antitrypanosomal activity in mice infected with Trypanosoma rhodesiense.
(4) The effects of Ng-nitro-L-arginine were reversed by L-arginine.
(5) The best compound was trans-alpha-[[(4-bromotetrahydro-2H-pyran-3-yl) amino]methyl]-2-nitro-1H-imidazole-1-ethanol (18), which, due to its activity and log P value, is a candidate for additional in vivo studies.
(6) In addition, cell lines exhibiting increased resistance to N-methyl-N'-nitro-N-nitrosoguanidine have been derived from a cell line expressing the Ada protein methylphosphotriester repair function.
(7) It is likely that nitro substitution at the 6-position of 5-MeC interferes with the structural requirements of the 1,2-diol-3,4-epoxide which are necessary for specific DNA interactions.
(8) After mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine and penicillin selection, two kinds of B(12) transport mutant were isolated from this strain.
(9) AOAA-induced (0.25 mumol-1 mumol) striatal lesions in adult rats displayed excitotoxic characteristics and could be prevented by the N-methyl-D-aspartate (NMDA) receptor antagonists (-)-2-amino-7-phosphono-heptanoate (AP7; 0.25 mumol) or kynurenate (KYNA; 0.5 mumol), but not by the non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX; 0.25 mumol).
(10) The oxidation of the anion radical intermediate by O2 to the parent nitro compound is proposed to account for the well-known O2 inhibition of microsomal nitroreductase.
(11) The complexes are produced by attachment of a carbon of the butenolide ring to an aromatic carbon of the nitro compound with formation of a charge-delocalized cyclohexadienate anion.
(12) With these compounds, the spin density at the nitro group was greater than with nifurtimox, nitrofurazone and nitrofurantoin.
(13) Amino and nitro groups, introduced at position-4 of estrone 3-methyl ether were particularly carcinostatic, a property not shared by 4-bromoestrone 3-methyl ether.
(14) The labeled egg albumin was hydrolyzed in 6N HCl at 110 degrees C for 24 h. The hydrolysate was lyophilized, derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole, a fluorogenic reagent for amines, and subjected to HPLC.
(15) Nitroreductases must therefore be able to compete successfully with molecular oxygen for the MISO nitro radical-anion in such tissues.
(16) It has been suggested that under aerobic conditions the aziridine ring is primarily responsible for aerobic toxicity, whereas under hypoxic conditions, the aziridine moiety combined with a reduced 2-nitro moiety produces a bifunctional agent (I. J. Stratford et al., Br.
(17) N omega-Nitro-L-arginine methyl ester (NAME) (10(-5) to 5 x 10(-4) M) abolished ijps in both tissues, an effect overcome by 10(-3) M L-arginine but not D-arginine.
(18) The incidence, number, and histological types of gastric cancers induced by N-methyl-N'-nitro-N-nitrosoguanidine and the tissue norepinephrine concentration of the gastric wall were investigated in spontaneously hypertensive rats and in control Wistar Kyoto rats and Wistar rats.
(19) A nitroreductase enzyme has been isolated from Walker 256 rat carcinoma cells which can convert 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB 1954) to a cytotoxic DNA interstrand crosslinking agent by reduction of its 4-nitro group to the corresponding hydroxylamino species (Roberts JJ et al., Biochem Biophys Res Commun 140: 1073-1078, 1986; Knox RJ et al., Biochem Pharmacol 37: 4661-4669, 1988).
(20) In contrast, nordihydroguaiaretic acid, metyrapone, NG-monomethyl-L-arginine, and nitro-L-arginine all attenuated the relaxation to acetylcholine; however, indomethacin had no effect on acetylcholine-induced relaxations.
Univalent
Definition:
(a.) Having a valence of one; capable of combining with, or of being substituted for, one atom of hydrogen; monovalent; -- said of certain atoms and radicals.
Example Sentences:
(1) Experiments indicated that complement deposition altered functionally bivalent IgG3 antibody in the immune complex into a univalent one.
(2) Equilibrium measurements of interactions of anti-DNP antibodies, prepared using DNP-PLL and several DNP-proteins for immunization, with DNP(0.6)-PLL(240) and with the univalent hapten, epsilon-DNP-L-lysine, were made utilizing the technique of fluorescence quenching.
(3) Explicit expressions are derived which describe the binding of a univalent ligand to equivalent and independent sites on each state of an acceptor undergoing indefinite self-association that is governed by an isodesmic equilibrium constant KI.
(4) A computer model was constructed which can generate all of the common univalent behaviours.
(5) In these male cells there was no decrease of chiasmata or increase of autosomal univalents with age, and there were some interstrain differences.
(6) Two homogeneous univalent hapten-protein conjugates, prepared by the covalent attachment of a single 2,4-dinitrophenyl (DNP-) or 2,4,6-trinitrophenyl (TNP-) side chain to the cysteine-SH in the active site of the enzyme papain, have been found to exhibit large Cotton effects in the wavelength region of the absorption bands of the DNP or TNP groups.
(7) Equivalent concentrations of binding sites of the bivalent F(ab)2 and univalent Fab fragments of anti-CEA were identical to the immunoglobulin G fraction in the standard inhibition curve.
(8) At a hydrophobic surface, molecules move apart and local water becomes strongly bonded, inert, and viscous and accumulates large cations, univalent anions, and compatible solutes.
(9) Of particular interest in that regard is the observation that the traditional logit-log analyses yield linear plots with the predicted slope of unity even though antigen univalence is an implicit assumption in their application.
(10) (3) The two stable states of the nerve membrane, which are readily demonstrable in TEA-treated or internally perfused squid giant axons, are shown to represent bivalent cation-rich and univalent cation-rich states of the nerve membrane.
(11) Only benzaldehyde dehydrogenase I is activated by K(+) and certain other univalent cations.
(12) Male meiosis in Mesostoma ehrenbergii ehrenbergii (2x = 10) is characterized by extreme restriction of chiasma formation; 3 pairs of chromosomes form bivalents at metaphase I which are associated by single very distally localized chiasma, while two pairs of chromosomes remain as unpaired univalents.
(13) Human red blood cells (RBCs) that are deficient in an integral membrane-associated protein ("stomatin") of apparent molecular mass 31 Kd show a catastrophic increase in passive membrane permeability to the univalent cations Na+ and K+ and are stomatocytic in shape.
(14) We demonstrate that shifts of the conductance-voltage (g-V) characteristic of PG films produced by changes of univalent or divalent cation concentrations result from changes of the membrane surface potential on one or both sides.
(15) The electrical resistances and rates of self-exchange of univalent critical ions across several types of collodion matrix membranes of high ionic selectivity were studied over a wide range of conditions.
(16) The steady-state solutions (Kirchhoff-Hill theorem) yield expressions for the relationship between the small signal conductance of univalent ions and the concentration of these ions in the external bathing medium (a saturation curve) and for the ionic currents and the steady-state current-voltage curve (N-shaped).
(17) The incidence of oocytes with univalents in the slides made by Tarkowski's method was much higher than in those made by ours in both age and strain groups (P less than 0.05-0.001).
(18) Our findings support the assumption that the altered activity of the Na-K-ATPase (modified by the presence of Ca-2+) is responsible for the univalent cation activation of the CaATPase.
(19) Under the conditions used univalent cations (Na(+),K(+) and Li(+)) inhibited the binding.
(20) The k-absorption edge spectrum of LyCuLP was consistent with the coordination of univalent copper.