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Biomedical subjects

D Levine

Publications and source records attributed to D Levine.

At least 163 records · Page 9Linked to original sources
PubMed1977

Elimination of canrenone in congestive heart failure and chronic liver disease.

The elimination half-life (T1/2) of canrenone, the principal unconjugated metabolite of spironolactone, was 59 h (range 32-105 h) in 5 patients with chronic liver disease and 37 h (range 19-48 h ) in 7 patients withcongestive heart failure. In comparison the T1/2 in normal subjects was 13.5-24 h in previous reports and 20.5 h in the present study, However there was no evidence of greater cumulation of canrenone in the plasma of those patients with a prolonged T1/2.

Aged↗
PubMed1977

Treatment environment and staff ideology in two British mental hospitals.

Hypotheses were derived from assumptions inherent in two contrasting conceptions of a treatment environment, attitudinal and ecological. Research was conducted in two different British mental hospitals, using scales from the OMI and the CTE. As predicted, the OMI scales were related only to staff attributes and did not discriminate among environments of institutions or units that differed in program, philosophy, organization, or type of patients. CTE scales distinguished between hospital treatment environments and wards. There was slight evidence that observed attributes influenced ecological measures of the objective treatment environment, or that staff ideology had any substantial impact upon treatment environments.

Adult↗
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

Furosemide and bumetanide: a study of responses in normal English and German subjects.

Diuretic responses to oral administration of 1 mg bumetanide and 40 mg furosemide were determined in double-blind, crossover balanced trials in 10 normal English subjects and 6 normal German subjects. In each experiment the 0- to 8-hr urine volume and sodium excretion were significantly higher after bumetanide, potassium excretion did not differ, and the Na/K ratio, although higher after bumetanide, was not significantly different by analysis of variance. In German subjects the diuretic and natriuretic responses to both drugs were greater and the potassium excretion less than in English subjects. In the English, the pretreatment 24-hr urinary Na/K ratio correlated with the urinary Na/K ratio response to both drugs and with the potassium excretion after furosemide. The mean plasma uric acid before treatment correlated with the Na/K ratio and potassium excretion after furosemide. Aldosterone excretion did not correlate with response to either diuretic. The mean pretreatment 24-hr log10 Na/K ratio in the two treatment periods of the English and German subjects correlated with the mean sodium excretion, potassium excretion, and log10 Na/K after the two diuretics, thus providing a partial explanation for intersubject and interstudy variation. Pretreatment log10 Na/K could also explain intrasubject variation, justifying its use as a covariate in covariance analysis. This demonstrated that at this dose ratio the urinary log10 Na/K ratio response to bumetanide was significantly higher than that to furosemide.

Aldosterone↗
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

Plasma uric acid concentration related to the urinary excretion of aldosterone and of electrolytes in normal subjects.

1. The relations between the concentration of plasma uric acid and urinary excretion of aldosterone, sodium and potassium, were studied in ten healthy males on a diet containing 160 mmol of sodium and 90 mmol of potassium per day. 2. Plasma uric acid correlated positively with aldosterone excretion and this correlation was statistically independent of sodium and potassium excretion. 3. Plasma uric acid correlated positively with potassium excretion and negatively with the urinary sodium/potassium ratio. There was no significant simple correlation with sodium excretion but the partial correlation of plasma uric acid and sodium excretion was negative and significant when excretion of aldosterone and potassium were held constant.

Adult↗
PubMed1975

Proteins of bacteriophage phi6.

We investigated the protein composition of the lipid-containing bacteriophage phi 6. We also studied the synthesis of phage-specific proteins in the host bacterium Pseudomonas phaseolicola HB10Y. The virion was found to contain 10 proteins of the following molecular weights: P1, 93,000; P2, 88,000; P3, 84,000; P4, 36,800; P5, 24,000; P6, 21,000; P7, 19,900; P8, 10,500; P9, 8,700; and P10, less than 6,000. Proteins P3, P9, and P10 were completely extracted from the virion with 1% Triton X-100. Protein P6 was partially extracted. Proteins P8 and P9 were purified by column chromatography. The amino acid composition of P9 was determined and was found to lack methionine. Labeling of viral proteins with [35S]methionine in infected cells indicated that proteins P5, P9, P10, and P11 lacked methionine. Treatment of host cells with UV light before infection allowed the synthesis of P1, P2, P4, and P7; however, the extent of viral protein synthesis fell off exponentially with increasing delay time between irradiation and infection. Treatment of host cells with rifampin during infection allowed preferential synthesis of viral proteins, but the extent of synthesis also fell off exponentially with increasing delay time between the addition of rifampin and the addition of radioactive amino acids. All of the virion proteins were seen in gels prepared from rifampin-treated infected cells. In addition, two proteins, P11 and P12, were observed; their molecular weights were 25,200 and 20,100, respectively. Proteins P1, P2, P4, and P7 were synthesized early, whereas the rest began to increase at 45 min post-infection.

Amino Acids↗