10 research outputs found
Cognitive Information Processing
Contains reports on four research projects.Providence Gravure, Inc. (Grant)International Business Machines Corporation (Grant
Cognitive Information Processing
Contains goals, background, research activities on one research project and reports on three research projects.Center for Advanced Television StudiesAmerican Broadcasting CompanyAmpex CorporationColumbia Broadcasting SystemsHarris CorporationHome Box OfficePublic Broadcasting ServiceNational Broadcasting CompanyRCA CorporationTektronix3M CompanyProvidence Gravure Co. (Grant)International Business Machines, Inc
Protein Sulfenylation: A Novel Readout of Environmental Oxidant Stress
Oxidative
stress is a commonly cited mechanism of toxicity of environmental
agents. Ubiquitous environmental chemicals such as the diesel exhaust
component 1,2-naphthoquinone (1,2-NQ) induce oxidative stress by redox
cycling, which generates hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>). Cysteinyl thiolate residues on regulatory proteins are subjected
to oxidative modification by H<sub>2</sub>O<sub>2</sub> in physiological
contexts and are also toxicological targets of oxidant stress induced
by environmental contaminants. We investigated whether exposure to
environmentally relevant concentrations of 1,2-NQ can induce H<sub>2</sub>O<sub>2</sub>-dependent oxidation of cysteinyl thiols in regulatory
proteins as a readout of oxidant stress in human airway epithelial
cells. BEAS-2B cells were exposed to 0–1000 μM 1,2-NQ
for 0–30 min, and levels of H<sub>2</sub>O<sub>2</sub> were
measured by ratiometric spectrofluorometry of HyPer. H<sub>2</sub>O<sub>2</sub>-dependent protein sulfenylation was measured using
immunohistochemistry, immunoblotting, and isotopic mass spectrometry.
Catalase overexpression was used to investigate the relationship between
H<sub>2</sub>O<sub>2</sub> generation and protein sulfenylation in
cells exposed to 1,2-NQ. Multiple experimental approaches showed that
exposure to 1,2-NQ at concentrations as low as 3 ÎĽM induces
H<sub>2</sub>O<sub>2</sub>-dependent protein sulfenylation in BEAS-2B
cells. Moreover, the time of onset and duration of 1,2-NQ-induced
sulfenylation of the regulatory proteins GAPDH and PTP1B showed significant
differences. Oxidative modification of regulatory cysteinyl thiols
in human lung cells exposed to relevant concentrations of an ambient
air contaminant represents a novel marker of oxidative environmental
stress
Are Psychotherapies for Young People Growing Stronger? Tracking Trends Over Time for Youth Anxiety, Depression, Attention-Deficit/Hyperactivity Disorder, and Conduct Problems
Nontuberculous Mycobacteria in the Biofilm Microbiome of Private Well and Premise Plumbing
Investigating mitochondrial dysfunction in human lung cells exposed to redox-active PM components
Prokaryotic Hydrocarbon Degraders
Hydrocarbons have been part of the biosphere for millions of years, and a diverse group of prokaryotes has evolved to use them as a source of carbon and energy. To date, the vast majority of formally defined genera are eubacterial, in 7 of the 24 major phyla currently formally recognized by taxonomists (Tree of Life, http://tolweb.org/Eubacteria. Accessed 1 Sept 2017, 2017); principally in the Actinobacteria, the Bacteroidetes, the Firmicutes, and the Proteobacteria. Some Cyanobacteria have been shown to degrade hydrocarbons on a limited scale, but whether this is of any ecological significance remains to be seen – it is likely that all aerobic organisms show some basal metabolism of hydrocarbons by nonspecific oxygenases, and similar “universal” metabolism may occur in anaerobes. This chapter focuses on the now quite large number of named microbial genera where there is reasonably convincing evidence for hydrocarbon metabolism. We have found more than 320 genera of Eubacteria, and 12 genera of Archaea. Molecular methods are revealing a vastly greater diversity of currently uncultured organisms – Hug et al. (Nat Microbiol 1:16048, 2016) claim 92 named bacterial phyla, many with almost totally unknown physiology – and it seems reasonable to believe that the catalog of genera reported here will be substantially expanded in the future