Biomedical subjects

A Duchon

Publications and source records attributed to A Duchon.

3 recordsLinked to original sources

PubMed2007

Cre/loxP-mediated chromosome engineering of the mouse genome.

Together with numerous other genome modifications, chromosome engineering offers a very powerful tool to accelerate the functional analysis of the mammalian genome. The technology, based on the Cre/loxP system, is used more and more in the scientific community in order to generate new chromosomes carrying deletions, duplications, inversions and translocations in targeted regions of interest. In this review, we will present the basic principle of the technique either in vivo or in vitro and we will briefly describe some applications to provide highly valuable genetic tools, to decipher the mammalian genome organisation and to analyze human diseases in the mouse.

Animals↗

PubMed1992

The human visual system averages speed information.

It has been known for many years that human observers are unable to detect modest accelerations and decelerations in moving visual stimuli. We find that human observers can integrate speeds over many dots, moving at different speeds, producing a global speed percept analogous to the global direction percept first reported by Williams, D. W. and Sekuler, R. (1984, Vision Research, 24, 55-62). We measured speed discrimination for random dot stimuli which contained many different speeds. Our results show that observers always base their discrimination on the mean speed of the stimulus; changes in other stimulus characteristics (e.g. mode) are not detected. Moreover, discrimination thresholds for the global mean speed derived from many different speeds are comparable to those obtained with stimuli in which all dots move at the same speed suggesting that the internal noise associated with the encoding of speed information is quite high.

Differential Threshold↗

PubMed1988

Oxygen free radical involvement in ischemia and reperfusion injury to brain.

Evidence is presented which implicates increased oxygen free radicals during ischemia reperfusion of gerbil brain. Salicylate, which reacts with hydroxyl free radicals to yield dihydroxybenzoic acid (DHBA), was used as an in vivo trap. Brain ischemia for at least 5 min followed by reperfusion yielded significantly increased brain DHBA. Without reperfusion or with only 2 min of ischemia and then reperfusion, the production of DHBA was not increased. Increased levels of DHBA in brain correlated with ischemia reperfusion-mediated behavioral modification of gerbils, but salicylate administration did not protect against the behavior changes.

Animals↗