PubMed Health⌕ Search

Biomedical subjects

L Ramsay

Publications and source records attributed to L Ramsay.

30 records · Page 2Linked to original sources
PubMed1977

Spironolactone and canrenoate-K: relative potency at steady state.

Relative dose ratios of the mineralocorticoid antagonists spironolactone (100 mg and 200 mg daily) and canrenoate-K (200 mg daily) at steady state were defined in six healthy subjects with fludrecortisone as the mineralocorticoid agonist. The urine log 10 Na/K responses during spironolactone treatments were consistent with the law of mass action. The potency of canrenoate-K was 0.68 (95% C.L. 0.53 to 0.89) that of spironolactone on a weight basis. Approximately 72% of the renal antimineralocorticoid activity of spironolactone could attributed to the metabolite canrenone. The results at steady state are contrasted with those of a previously study comparing single doses of spironolactone and canrenoate-K.

Administration, Oral↗
PubMed1977

Plasma uric acid and plasma albumin in healthy subjects.

In healthy male subjects there was a positive correlation between plasma uric acid and plasma albumin (r = 0 - 43, P less than 0 - 005, n = 49) when repeated measurements of both variables were used for each subject. Changes in plasma albumin induced by in vivo ultrafiltration were not accompanied by changes in plasma uric acid. The correlation of plasma uric acid with plasma albumin cannot be attributed to protein binding of urate. The two variables are probably related indirectly through a common association with an unknown factor or factors.

Adolescent↗
PubMed1976

Antagonism of endogenous mineralocorticoids in normal subjects by prorenoate potassium and spironolactone.

The pharmacological activity of single oral doses of a new aldosterone antagonist, prorenoate potassium, has been compared with spironolactone and placebo in a balanced double-blind crossover study in six healthy subject. Endogenous mineralocorticoids were stimulated by administration of frusemide followed by dietary sodium restriction, and the urinary excretion of electrolytes in response to prorenoate potassium, spironolactone and placebo was measured over a 24 hour period. Significant activity of prorenoate potassium and spironolactone was observed between 2 - 24 hours after medication, with peak activity at 6 - 8 hours. The active drugs significantly increased sodium excretion and the sodium : potassium (Na/K) ratio, but changes in potassium excretion were not significant. The total urine Na/K response to prorenoate potassium 45 mg was significantly greater than to spironolactone 100 mg.

Adult↗
PubMed1976

Spironolactone and potassium canrenoate in normal man.

The pharmacological activity of single doses of the two aldosterone antagonists, potassium canrenoate and spironolactone, was examined in two studies in healthy volunteers. Both drugs were active in reversing urinary electrolyte changes induced by fludrocortisone in periods 2 to 16 hr after treatment. Potassium canrenoate was significantly less potent that spironolactone on a weight or molar basis, with best estimates of the relative potency potassium canrenoate: spironolactone of approximately 0.3:1. On a weight basis the two drugs yielded plasma levels of the metabolite canrenone which were approximately equivalent. The results indicate that canrenone is not the principal pharmacologically active metabolite of spironolactone. Our study suggests that a major part of the renal antimineralocorticoid activity of spironolactone may be attributable to minor sulfur-containing metabolites or their precursors having a high renal clearance that affords access to their site of activity via the renal tubular fluid.

Canrenoic Acid↗
PubMed1976

Prolactin, diuretics and urinary electrolytes in normal subjects.

The relationship of plasma prolactin concentration and renal electrolyte excretion has been investigated in six normal male volunteers. In two studies, 80 mg frusemide were administered at 18.00 h on Day 1 and followed by dietary sodium restriction. In study A, after 38 h of sodium depletion, a second dose of frusemide was administered at 08.00 h on Day 3. In study B, after 14 h of sodium depletion, the effect of administration of 100 mg spironolactone or 45 mg prorenoate potassium (another aldosterone antagonist) at 08.00 h on Day 2 was compared with that of a placebo. After the first dose of frusemide in study A, the mean plasma prolactin concentration correlated negatively with the urinary Na and K excretion over 5 h. After 38 h sodium depletion, the plasma prolactin concentration correlated positively with urinary Na excretion following the second dose of frusemide. In study B, after Na depletion for 14 h the plasma prolactin concentration of 08.00 h on Day 2 had a positive correlation with the 24 h urinary log10 Na:K ratio following placebo administration and had negative correlations with the true urinary log10 Na:K ratio following spironolactone and prorenoate potassium administration. Neither acute Na deprivation nor the administration of single doses of frusemide, spironolactone or proprenoate potassium appeared to affect the normal circadian rhythm of plasma prolactin concentrations which remained constant for each subject throughout the 3 months covered by the investigation. The correlations of plasma prolactin concentration to renal excretion of electrolytes, with no evidence for a negative feedback control mechanism, suggest an indirect relationship between prolactin and renal function.

Adult↗
PubMed1975

Relative potency of prorenoate and spironolactone in normal man.

The potency of single doses of a new aldosterone antagonist, prorenoate, in reversing the renal effects of the synthetic mineralocorticoid fludrocortisone was compared to that of spironolactone in a double-blind balanced crossover study in 12 healthy subjects. The potency of prorenoate potassium as related to elevation of the urinary log 10 10 Na/K ratio (2.69:1) and as related to potassium retention (3.75:1) was significantly higher than that of spironolactone. Prorenoate produced greater natriuresis (1.64:1) but the difference was not significant. There was evidence for a qualitative difference between spironolactone and prorenoate; the latter significantly more potent in retaining potassium than in increasing sodium excretion. The simple methodology described is based on standard bioassay principles, yielded a valid and sensitive comparison of the two drugs, and should prove useful in the evaluation of other aldosterone antagonists.

Adolescent↗
PubMedDate not supplied

Clinical research and the culture of collaboration.

This article aims to share some of the strategies and principles that facilitated the completion of an experimental research project undertaken at the Liverpool Health Service (formerly Liverpool Hospital) in the South West of Sydney. The experience demonstrated the interdependence of the academic and clinical nurse practitioners undertaking the project. A collaborative approach to nursing research in which complementarity of participants is recognised and valued is recommended.

Clinical Nursing Research↗
PubMedDate not supplied

Nurses facilitating reconciliation through education.

In 1996, Health of Indigenous Australian Peoples, was introduced as a compulsory unit in a Bachelor of Health Science in Nursing course and as an elective unit for students from other courses. The first cohort of students in the unit were surveyed to determine whether their attitudes to 21 issues that affect the health of Aboriginal people were more appropriate at the end of the unit than they had been before the unit. The findings were that the student group's post-unit attitudes were more appropriate in all 21 areas. The results support a recommendation that units designed to increase health workers understanding of issues that affect the health of Aboriginal people must be compulsory if reconciliation is to be achieved between Aboriginal and non-Aboriginal people.

Adult↗