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Biomedical subjects

R Lancaster

Publications and source records attributed to R Lancaster.

29 records · Page 2Linked to original sources
PubMed1976

The effect of pindolol on plasma renin activity and blood pressure in hypertensive patients.

1 The effect of pindolol administered to twenty-six patients with hypertension of unknown origin was compared with respect to blood pressure and plasma renin activity change after increase of the dose over a period of 6 weeks. 2 There was no clear correlation between the fall of plasma renin activity, which in some patients was very marked, and the fall in blood pressure. Some patients with a fall in plasma renin activity did not drop their pressure. Conversely, some with a fall of pressure did not drop their plasma renin activity. 3 The addition of hydrochlorothiazide to the pindolol finally caused further lowering of the blood pressure in all but one patient and the plasma renin activity rose in all but two patinets. There was no clear correlation between change in plasma renin activity and the effect on blood pressure.

Adult↗
PubMedDate not supplied

Brain dynamics, psychophysiological uncertainty and behavioral learning.

The present paper takes a first step toward the integration of recent findings on brain dynamics and learning into established fields of psychophysiological science. Leading-edge studies of brain dynamics have shown that the brain manifests an inherent variability and that, when new stimuli (i.e., "problems") are presented to the organism, brain chaos increases. Similarly, many previous studies using a wide variety of physiological and behavioral measures have shown that "psychophysiological uncertainty" is associated with novel stimuli, novice behavioral performance, and new stimulus-stimulus and response-stimulus contingencies. Such uncertainty may ultimately be resolved through some form of learning. Along with the general changes in physiological and behavioral activity, increases in brain chaos may usher the organism into an exploratory mode which serves as a catalyst for learning.

Animals↗
PubMedDate not supplied

Renal function, body fluid volumes, renin, aldosterone, and noradrenaline during treatment of hypertension with pindolol.

Sixteen hypertensive patients received pindolol (10-45 mg/day); mean +/- SD, 28.75 +/- 15.22) for 3-8 weeks in a placebo-controlled, single-blind, crossover study. Supine and standing blood pressures (BP) were lowered, whereas effective renal plasma flow and glomerular filtration rates (estimated from the clearances of Hippuran and EDTA during oral water loading) did not change consistently. "Blood volume" (calculated from 125I-human serum albumin space and microhaematocrit) increased, with a corresponding reduction in serum albumin but without a change in body weight or "total body water" (T2O space). The results suggest a transfer of water from the interstitial to the intravascular compartment. This was supported by estimates of "extracellular fluid volume" (EDTA space) and "interstitial volume" (EDTA) minus human serum albumin spaces) in 3 subjects. The changes produced in "blood volume" correlated with those in BP. Plasma levels of noradrenaline, renin activity, and aldosterone were reduced, as was renal aldosterone excretion. There was no correlation between the changes produced by pindolol in BP and these hormone levels. Pindolol treatment reduced serum calcium concentration. There was a strong positive correlation between changes in BP and serum calcium and renal calcium excretion.

Adult↗