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Biomedical subjects

K M Dewar

Publications and source records attributed to K M Dewar.

45 records · Page 3Linked to original sources
PubMed1980

Preliminary experience with ICI 35 868 as an i.v. induction agent: comparison with althesin.

In a small open dose-finding study the i.v. dose of ICI 35 868 required to induce anaesthesia in healthy adults was 2 mg kg-1. Comparison of this dose with Althesin 0.05 ml kg-1 for i.v. induction, both injected over 30 s suggests that they have similar effects on heart rate, arterial pressure and breathing. The mean times to loss of eyelash reflex were 57 +/- SD 10.1 s (ICI 35 868) and 46 +/- 3.9s (Althesin). The new drug was associated with pain and discomfort on injection in seven of 10 patients, but with less involuntary movement than occurred with Althesin.

Adolescent↗
PubMed1979

Glycopyrrolate as a premedicant: comparison with atropine.

A double-blind comparison of glycopyrrolate with atropine as the anticholinergic component of premedication was made in 200 patients undergoing minor or intermediate surgical procedures. Glycopyrrolate was associated with a smaller increase in heart rate, but there was no difference between the drugs in respect of cardiac arrhythmia, change in arterial pressure, control of secretions in the upper respiratory tract, frequency of nausea and vomiting after operation or subjective well-being of the patients.

Adolescent↗
PubMed1977

Recognition memory for single tones with and without context.

Sequences of seven tones were presented, and recognition memory for individual tones of each sequence was tested under varying degrees of context. With no context, the test required recognition of a tone isolated from the sequence; with full context, the tone to be recognized was embedded in the original sequence. A series of three experiments demonstrated that recognition memory was far more accurate under full-context conditions than under no-context conditions and that the superiority was not wholly attributable to the serial position information or the order information provided by the full context. It is suggested that in addition to the processing of limited information for the pitch of isolated tones, pattern (or relational) information is abstracted from a tone sequence and is retrieved in the presence of full context.

Association↗
PubMedDate not supplied

Dopamine receptor alterations correlate with increased GABA levels in adult rat neostriatum: effects of a neonatal 6-hydroxydopamine denervation.

The effects of neonatal intracerebroventricular 6-hydroxydopamine (6-OHDA) injection on the densities of dopamine (DA) receptors and GABA levels were determined in the rostral neostriatum of adult rats. Measurement of GABA turnover indicated that increased tissue GABA in the DA-lesioned neostriatum is a consequence of higher GABA synthesis rate (205%). Binding experiments with [3H]SCH23390 (D1 receptors) and [3H]raclopride (D2 receptors) point to a correlation between tissue GABA content and altered DA receptors. Three months after the lesion there was a 27% decrease in D1 receptors and a 22% increase in D2 receptors. In control neostriatum, GABA levels were inversely related to D2 receptors and this relationship was reversed after 6-OHDA treatment. In contrast, the positive correlation between GABA and D1 receptors remained unchanged after the lesion. Irreversible blockade of DA receptors by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) decreased both D1 and D2 sites (73-87%) in both control and lesioned neostriatum, but increased GABA levels by 25% only in animals which have received 6-OHDA just after birth. Following acute inhibition of DA synthesis or of DA catabolism, GABA levels remained unchanged. The present results indicated that DA depletion by itself is not the cause for the increase in GABA levels. The augmented GABAergic activity following neonatal 6-OHDA is seemingly influenced primarily by DA receptor status; presumably, changes in D2 receptor properties during maturation may be a principal cause for an increase in neostriatal GABA content.

Animals↗