BspA is an abundant surface protein from Lactobacillus fermentum BR11, and is required for normal cystine uptake. In previous studies, a mutant strain deficient in BspA (L. fermentum PNG201) was found to be sensitive to oxidative stress. In this study, the biochemical basis for this was explored. It was found that under aerobic batch culture conditions in de Mann-Rogosa-Sharpe medium, both L. f...

The photo-induced formation of peroxide ions on the surface of cubic Ln2O3 (Ln = Nd, Sm, Gd) was studied by in situ microprobe Raman spectroscopy using a 325 nm laser as excitation source. It was found that the Raman bands of peroxide ions at 833-843 cm(-1) began to grow at the expense of the Ln(3+)-O(2-) bands at 333-359 cm(-1) when the Ln2O3 samples under O2 were continuously irradiated with ...

A fundamental study of the stability of hydrogen peroxide-based gels, thickened using cross-linked polyacrylic acid polymers, will be presented. Recent systematic experiments will demonstrate that excellent long-term stability of such gels can be achieved. The study evaluates different types of crosslinked polyacrylic acid polymers (as well as an associative acrylic polymer), several commercial...

Excessive generation of free radicals has been implicated in several pathological conditions. We demonstrated previously that peroxide-generated free radicals decrease calcium-dependent high K(+)-evoked L[3H]-glutamate release from synaptosomes while increasing calcium-independent basal release. The present study evaluates the nonvesicular release of excitatory amino acid neurotransmitters, usi...

Lactoperoxidase and thiocyanate were shown to protect Escherichia coli and three oral streptococcal species from the bactericidal effect of hydrogen peroxide under aerobic conditions. Lactoperoxidase in the absence of thiocyanate was also protective for two of the bacterial species in a dilution medium but potentiated hydrogen peroxide toxicity for the other two under the same conditions. The p...

A new method for the determination of glutathione peroxidase activity in erythrocytes was developed. The present method was applied to the measurement of hydrogen peroxide removal rates by glutathione peroxidase in erythrocytes at 70 microM hydrogen peroxide under simulated in vivo conditions. The removal rates by glutathione peroxidase in mouse erythrocytes were twenty-times faster than those ...

A brightness of 76% (initially 57%) was reached with a charge of 4.5% hydrogen peroxide based on thermomechanical pulp in 10 min with microwave heating, compared to 45 min with water-bath heating. The maximum brightness attained with water-bath heating (78%) was nearly one point higher than that obtained with microwave heating, albeit after twice the time (120 min vs. 60 min). Under similar con...

The results of research carried out on rats, assessing the influence of chronic intoxication with ethanol, methanol, and ethylene glycol on hydrogen peroxide concentration in internal organs – brain, lungs, liver, kidney, and heart – are presented in this paper. It was shown that the organ most exposed to the detrimental activity of ethanol, methanol, and ethylene glycol is the heart: the great...

Understanding intracellular redox chemistry requires new tools for the site-specific visualization of intracellular oxidation. We have developed a spatially-resolved intracellular sensor of hydrogen peroxide, HyPer-Tau, for time-resolved imaging in live cells. This sensor consists of a hydrogen peroxide-sensing protein tethered to microtubules. We demonstrate the use of the HyPer-Tau sensor for...

To determine the regulatory role of p72syk in lymphocyte activation, peripheral blood lymphocytes were treated with 10 mM hydrogen peroxide. Hydrogen peroxide induced a rapid elevation of p72syk activity (4-6-fold) and a dramatic increase in tyrosine phosphorylation of a number of cellular proteins, including phospholipase C gamma 1 (PLC gamma 1) and p72syk. Monoclonal antibodies to PLC gamma 1...