Biomedical subjects

J R Compton

Publications and source records attributed to J R Compton.

4 recordsLinked to original sources

PubMed2005

Transcriptional induction of cholinesterase expression and protection against chemical warfare nerve agents.

We investigated whether transcriptional inducers could enhance the expression of acetylcholinesterase (AChE) in cell lines to achieve protection against organophosphate (OP) poisoning. Trichostatin A (TSA), an inhibitor of histone deacetylase that de-condenses chromatin and increases the binding of transcription factors and mRNA synthesis, induced three- to four-fold extracellular and 8-10-fold intracellular AChE expression at the optimal dose of 165-333 nM in Neuro 2A cells. Pre-treatment with TSA protected against OP exposure. Thus, transcriptional inducers, such as TSA, up-regulate AChE, which then can scavenge the OP and protect the cells from OP-induced toxicity, and are potential novel ways to treat chemical warfare nerve agent (CWNA) exposure.

Animals↗

PubMed1984

The effect of square wave exposure profiles upon the performance of passive organic vapor monitoring badges.

Three commercially available passive organic vapor monitoring badges were exposed to ethyl benzene vapor in a dynamic test atmosphere characterized by well defined square wave concentration profiles having periods of 2, 6, and 10 minutes. These concentrations fluctuations between zero and 150 ppm caused no significant bias in the TWA concentration indicated by the badges. A slight, but statistically significant, interaction between badge type and exposure profile is attributable to random analytical error in the data provided by one badge type.

Air Pollutants, Occupational↗

PubMed1982

Analysis of the effect of temporal frequency on the dichoptic visual-evoked response.

When observers with normal binocularity view reversing black and white checkerboard patterns, the amplitude of the resulting binocular visual-evoked response (VER) is significantly greater than the amplitude of either corresponding monocular response. When the same checkerboard pattern is dichoptically presented with an interocular luminance difference (1.3 to 2.0 log units), the amplitude of the dichoptic VER is significantly less than either monocular response. In a previous study, we attributed this effect to interference between the monocular components of the binocular response resulting from a phase shift induced by the interocular luminance difference. To test this hypothesis, dichoptic VER's were recorded for three temporal frequencies (1.88, 3.75, and 7.5 Hz). The results obtained support the phase shift interpretation.

Adult↗

PubMed1982

Interocular luminance differences and the binocular pattern-reversal visual-evoked response.

Although the visual-evoked response (VER) is frequently used to assess binocularity, the contribution of the monocular components to the binocular VER is poorly understood. To more fully elucidate this relationship, we examined checkerboard (14 min arc checks) pattern-reversal (3.75 Hz) VERs evoked from observers with normal binocularity, with conditions in which interocular luminance differences (from 0.3 to 2.0 log units) were established. When compared with monocular VERs obtained with similar luminances, the binocular response was always less than the sum of the component monocular responses. In addition, the amplitude of the binocular signal was dependent on the amount of interocular luminance the difference. For interocular luminance differences of less than 0.6 log units the amplitude of the binocular response was consistently greater than either corresponding monocular VER. When the interocular luminance difference was 1.3 log units or greater the amplitude of the binocular response fell below the level of either corresponding monocular response. Furthermore, it does not appear that these results can be attributed to a passive spread of electrical potentials from monocular cortical cell populations. We therefore suggest that these results indicate the activity of a binocular neural process.

Adult↗