Peace and the healing process.
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Biomedical subjects
Publications and source records attributed to J Hume.
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1. Current-clamp experiments were carried out with guinea-pig papillary muscles to determine the dependence of depolarization-induced automaticity on endogenous catecholamines. 2. Catecholamine depletion was produced by pre-treatment of animals with 6-hydroxydopamine and confirmed by fluorimetric assay of right ventricular tissue. Papillary muscles from depleted animals demonstrated a marked suppression of depolarization-induced automaticity for maximum diastolic potentials less negative than -55 mV. This suppression was completely reversed by noradrenaline but not by tyramine. 3. In normal tissue, noradrenaline and tyramine had much smaller effects on automaticity arising from maximum diastolic potentials negative to -55 mV than on repetitive activity arising positive to this level. 4. L-propranolol in concentrations of 2-3 x 10(-7) M reduced repetitive activity in the less negative range of maximum diastolic potential. No evidence of direct membrane depression was observed at these doses and the effect was reversed by application of noradrenaline. 5. D-propranolol, the isomer with much lower beta-receptor blocking potency, required twentyfold higher concentrations to depress automaticity and this was accompanied by evidence of direct membrane depression, i.e. reduction of upstroke velocity of action potentials. 6. These results show that automaticity induced in guinea-pig papillary muscles by depolarization positive to -55 mV is strongly dependent upon endogenous catecholamines. 7. The hypothesis that endogenous catecholamines facilitate depolarization-induced automaticity through an increase in calcium conductance was modelled using numerical techniques. It was found that changes in calcium conductance caused changes in the model which closely parallelled the experimental effects of catecholamine depletion and beta-blockade. The effects of changes in delayed rectification in the model did not accurately reproduce the experimental results.
Preoperative cross match guidelines were developed from a review of elective surgical hemotherapy. Six elective surgical procedures were studied prospectively to determine the effectiveness of the recommendations. All six procedures demonstrated a substantial reduction in preoperative cross match ordering during the study period, although for only one procedure was the guidelines' recommendation followed strictly. For those procedures that rarely required hemotherapy, an ABO-Rh typing and an antibody detection test were recommended as a preoperative study without a cross match. Through education of the clinical staff, successful establishment of these guidelines can lead to substantial monetary savings, reduced blood outdating, and a decreased blood bank workload with a more appropriate allocation of the technologists' time and effort.
This article describes how a nurse-led clinic to care for patients with glaucoma was set up and provides some initial evidence of its success. The authors also explain how they have developed the clinic further and their plans for the future.