صفحه 1 از جانب 21 نتایج
BACKGROUND
Cellular debris, an indicator of cell death, appears in limb buds of gestational day 12 rabbit embryos 4 hr after either a subcutaneous injection of hydroxyurea to pregnant rabbits or an injection of hydroxyurea into the exocoelomic cavities of the embryos. This episode of early cell
The 2.8 A crystal structure of hydroxylamine oxidoreductase of a nitrifying chemoautotrophic bacterium, Nitrosomonas europaea, is described. Twenty-four haems lie in the centre bottom of the trimeric molecule, localized in four clusters within each monomer. The haem clusters within the trimer are
The rat conceptus biotransforms N-methyl-N-(7-propoxynaphthalene-2-ethyl)hydroxylamine (QAB) in vitro to 7-propoxynaphthalen-2-ylacetic acid (QAA) and six more (M1 to M6) metabolites. Thus far, M4 has been identified as N-demethyl-QAB and M6 as N-desoxy-QAB. We investigated which of these two
Hydroxylamine (HA) is an important reducing agent that is used in several industries. HA is a moderate irritant and a powerful inducer of methemoglobinemia. HA has been shown to react readily with DNA in vitro. Several chemical derivatives of HA are potent developmental toxicants, whereas HA has
Aromatic and heteroaromatic amines (ArNH(2)) represent a class of potential mutagens that after being metabolically activated covalently modify DNA. Activation of ArNH(2) in many cases starts with N-hydroxylation by P450 enzymes, primarily CYP1A2. Poor understanding of structure-mutagenicity
Halorhodopsin is a retinal protein with a seven-transmembrane helix and acts as an inward light-driven Cl(-) pump. In this study, structural state of the solubilized halorhodopsin (NpHR) from the biomembrane of mutant strain KM-1 of Natronomonas pharaonis in nonionic detergent was investigated. A
Mono-, dicarboxylic acid-, and D-glucose transport were measured in brush border vesicles from renal cortex after treatment with reagents known to modify terminal amino, lysyl, epsilon-amino, guanidino, serine/threonine, histidyl, tyrosyl, tryptophanyl and carboxylic residues. All three
Generation of superoxide radicals by the mitochondrial respiratory chain of cardiomyocites isolated from rat heart and treated with saponin was studied. The rate of O2- production was measured by electron paramagnetic resonance (EPR) spectroscopy using hydroxylamine TEMPONE-H as spin trap. A device
Although the Gram-negative, anaerobic periodontopathogen Porphyromonas gingivalis must withstand nitrosative stress, which is particularly high in the oral cavity, the mechanisms allowing for protection against such stress are not known in this organism. In this study, microarray analysis of P.
In order to estimate the size of the cavity remaining around the heme of the 3A3-microperoxidase 8 (MP8) hemoabzyme, the formation of 3A3-MP8-Fe(II)-nitrosoalkane complexes upon oxidation of N-monosubstituted hydroxylamines was examined. This constituted a new reaction for hemoabzymes and is the
Corynebacterium matruchotii is a microbial inhabitant of the oral cavity associated with dental calculus formation. It produces membrane-associated proteolipid capable of inducing hydroxyapatite formation in vitro. This proteolipid was purified from chloroform:methanol extracts by chromatography on
The manganese-containing (MnSOD) and iron-containing (FeSOD) superoxide dismutases from Escherichia coli are extensively (greater than 95%) inactivated by treatment with phenylglyoxal. The relatively high concentrations of phenylglyoxal and high pH required for optimal inactivation suggest that
OBJECTIVE
The objectives of the present work were to improve the cyclotron production yield of (89)Zr using a solution target, develop a practical synthesis of the hydroxamate resin used to process the target, and develop a biocompatible medium for (89)Zr elution from the hydroxamate
The complete amino acid sequence of winged bean basic agglutinin (WBA I) was obtained by a combination of manual and gas-phase sequencing methods. Peptide fragments for sequence analyses were obtained by enzymatic cleavages using trypsin and Staphylococcus aureus V8 endoproteinase and by chemical
The absorption and self-assembly of a dithiocarbamate calix[4]arene derivative (DTCX) on Ag nanoparticles (NPs) was characterized in this work by surface-enhanced Raman scattering (SERS). This study was carried out on Ag NPs prepared by chemical reduction of silver nitrate with two different