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Biomedical subjects

D Reese

Publications and source records attributed to D Reese.

24 records · Page 2Linked to original sources
PubMed1987

Action of trapidil on the heart contractility: relationship to the cyclic nucleotide metabolism.

The relationship between the cardiotonic action of trapidil (RocornalR) and cyclic nucleotide metabolism was studied in the isolated rat heart. The contractility of the heart was increased in a concentration-dependent manner by this drug (ED50 20/microM). Parallel with the mechanical changes the tissue levels of cyclic AMP were increased, which was associated with an activation of the cAMP-dependent protein kinase. Cyclic GMP was enhanced only at a drug concentration of 1 mM. The present findings support the hypothesis that the cyclic nucleotide system is involved in the functional action of trapidil on cardiac tissue.

Animals↗
PubMed1987

Transient activation of cyclic AMP-dependent protein kinase and phosphorylase during the cardiac cycle in the canine myocardium in situ and the effect of propranolol.

The activity ratio of cyclic AMP-dependent protein kinase and glycogen phosphorylase were determined at various stages of the contraction cycle in the canine heart in situ. Both activity ratios vary transiently throughout the contraction-relaxation cycle, the higher values occurring during systole. The rise in the activity ratio of protein kinase was found to coincide with the maximum in the level of cyclic AMP. Propranolol pretreatment prevents the transient in the level of the nucleotide as well as in the activity ratio of the kinase indicating i) a causal relationship between these changes and ii) a neurohumoral, beat-to-beat regulation by catecholamines. Contrary the activity ratio of phosphorylase retains, in the presence of propranolol, its transient changes during the cardiac cycle, probably caused by a Ca2+-mediated activation of phosphorylase kinase during the contraction process.

Animals↗
PubMedDate not supplied

Pursuit eye movements in late-onset esotropia.

Horizontal, smooth pursuit eye movements were recorded from adults and children with infantile and late-onset esotropia using a remote, video-based, eye-movement recording system. Each subject monocularly tracked a 0.5-degree target moving back and forth on a video monitor at a constant velocity of 10 degrees, over a range of 12 degrees. Each subject's nasal and temporal gain (eye velocity/target velocity) was measured. Confirming the results of previous studies, we found that infantile esotropes had asymmetrical pursuit eye movements (nasal gain greater than temporal gain) while late-onset esotropes had symmetrical gains. However, unlike previous investigators, we found that half of the late-onset esotropes had impaired pursuit gain. The magnitude of the pursuit abnormality and the amount of refractive error were correlated--patients with the highest refractive error had the lowest pursuit gain.

Adult↗