Biomedical subjects

C E Byrne

Publications and source records attributed to C E Byrne.

2 recordsLinked to original sources

PubMed2002

The contribution of genetic factors to thrombotic and bleeding outcomes in coronary patients randomised to IIb/IIIa antagonists.

Genetic variants are risk factors for coronary disease, but their role in recurrent events and in response to treatment is less clear. We genotyped genetic variants implicated in primary coronary disease in 924 Caucasians with acute coronary syndromes participating in the OPUS-TIMI16 trial of the GPIIb/IIIa antagonist orbofiban. These were the platelet glycoprotein (GP) receptors GPIIIa, GPIa, GPIbalpha; platelet ligands beta-fibrinogen and von Willebrand Factor (vWF); interleukins (IL) IL-1RN, and IL-6; adhesion proteins E-selectin and P-selectin; and metalloproteinase MMP-9. Cox modelling of all genetic variants demonstrated no significant impact on the composite endpoint (P = 0.88), which included myocardial infarction (MI), death, recurrent ischemia, urgent revascularisation and stroke, but a significant impact on recurrent myocardial infarction alone (chi(2) = 20.4, 10 df, P = 0.04). There was a significant interaction of the polymorphisms with orbofiban treatment influencing bleeding outcomes (P = 0.004). Thus, genetic polymorphisms may be associated with subsequent myocardial infarction, and may also be associated with treatment-associated bleeding among coronary patients.

Alanine↗

PubMed1991

Does primate motion perception depend on the magnocellular pathway?

This study examined the importance of the primate magnocellular retinocortical pathway in the perception of moving stimuli. A portion of the magnocellular pathway was permanently and selectively interrupted by ibotenic acid injections in the LGN of macaque monkeys. We then tested contrast sensitivity for detecting moving stimuli, as well as two indices of motion perception, contrast sensitivity for opposite direction discrimination and speed difference thresholds, in the affected portion of the visual field. Magnocellular lesions greatly reduced detection contrast sensitivity at high temporal and low spatial frequencies and had a similar effect on contrast sensitivity for opposite direction discrimination under these same stimulus conditions. Consequently, opposite direction discriminations could be made at contrast threshold, suggesting that magnocellular lesions reduced the visibility of stimuli used to test direction perception, but did not act directly on direction perception. Magnocellular lesions also elevated speed difference thresholds under some stimulus conditions. However, this deficit was reduced or eliminated by raising the contrast of the test stimulus. Together, these findings suggest that magnocellular lesions reduce the visibility of stimuli used to test motion perception but that they do not appear to alter motion perception otherwise.

Animals↗