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Biomedical subjects

A Frazer

Publications and source records attributed to A Frazer.

At least 109 records · Page 6Linked to original sources
PubMed1980

Monoamine oxidase inhibitors and serotonin uptake inhibitors: differential effects on [3H]serotonin binding sites in rat brain.

Rats were administered either monoamine oxidase inhibitors or serotonin uptake inhibitors for either 1, 4 or 16 days. The binding of [3H]serotonin to brain homogenates and the concentration of serotonin in brain was measured at these times. Treatment with inhibitors of serotonin uptake did not change the specific binding of [3H]serotonin in either cerebral cortex or hippocampus, nor did it produce any consistent alterations in the concentration of serotonin in the cerebral cortex. In contrast, monoamine oxidase inhibitors capable of inhibiting A-type monoamine oxidase significantly decreased [3H]serotonin binding after both 4 and 16 days of treatment; serotonin concentrations were significantly elevated at all time intervals. Inhibitors of B-type monoamine oxidase had no effect on either [3H]serotonin binding or serotonin concentrations in cerebral cortex. The reduction in labeled serotonin binding caused by monoamine oxidase inhibitors is due to a decrease in the maximum number of specific binding sites with no change in the affinity of the binding sites for labeled serotonin.

Amitriptyline↗
PubMed1980

Prediction of dosage of lithium carbonate: use of a standard predictive method.

The nomogram developed by Cooper and associates used to predict the dose of Lithium Carbonate (Li+) which is needed to attain therapeutic Li+ concentrations has, in general, proven to be accurate and clinically useful. However, there may be some patients in whom the pharmacokinetic disposition of Li+ varies sufficiently so that accurate dosage predictions cannot be made; a report of one such patient is given.

Bipolar Disorder↗
PubMed1979

The erythrocyte lithium-plasma lithium ratio in patients with primary affective disorder.

Increasing attention has been given to the significance of intra-cellular concentrations of the lithium ion in patients treated with this drug. The erythrocyte has been the most common cell investigated because of its accessibility and certain similarities between the ion transport mechanisms of this cell and the neuron. Intraerythrocyte lithium is expressed as the ratio of lithium in the cell to the plasma lithium concentration (lithium ratio). The lithium ratio has been reported to be related to a number of clinical variables, including treatment response, clinical state, side-effects, toxicity, diagnosis, and electrophysiological effects. We have investigated the lithium ratio in a large series of patients with a primary affective disorder and in a smaller control group. We found a significantly higher mean lithium ratio in the bipolar diagnostic group than in the unipolar and control groups. There was a trend, not statistically significant, in the unipolar and bipolar groups for females to have higher lithium ratios than males. While not diagnostic, the lithium ratio appears to be another biological variable where bipolar patients, as a group, differ from normals and others with an affective disorder.

Bipolar Disorder↗
PubMed1979

Plasma and erythrocyte cations in affective illness.

Plasma and erythrocyte cations (sodium and magnesium) were studied in groups of patients with an affective disorder and in normal subjects. Baseline determinations were obtained before initiation of treatment for mania or depression. In a subgroup of patients, sequential measurements of cations were made during treatment with lithium carbonate. No differences were found in intraerythrocyte sodium or magnesium among any of the patient groups and controls. Patients with a primary affective disorder had significantly higher plasma sodium than control subjects. Neither baseline cation concentrations nor changes in cation concentration during treatment with lithium correlated with treatment response. Gender was shown to be a significant variable affecting intraerythrocyte cation concentrations.

Bipolar Disorder↗
PubMed1978

Red blood cell Li+ to plasma Li+ ratios. Are they related to plasma Li+ concentrations?

The relationship between the lithium ratio (ratio of lithium in blood cells to that in plasma) and plasma lithium concentration was examined in a group of male inpatients taking lithium carbonate for affective disorders. The lithium ratio was found to increase in the majority of these patients as plasma lithium concentration increased. However, the magnitude of variation of the lithium ratio with plasma lithium concentration observed in these patients is not sufficient to seriously affect the value of determining the lithium ratio in the clinical situation.

Erythrocytes↗
PubMed1978

Erythrocyte concentrations of the lithium ion: clinical correlates and mechanisms of action.

When lithium carbonate is administered to individuals, there is considerable intersubject variation in the extent of accumulation of Li+ by erythrocytes. The primary reason for this is differences in the activity of a Li+-Na+ counterflow system, which, under clinical conditions, removes Li+ from the cell. It appears that some bipolar patients accumulate more Li+ in their red cells than either unipolar depressives or normal controls. The precise clinical characteristics of the bipolar patients who accumulate relatively large amounts of erythrocyte Li+ need to be clarified in future research. Finally, the measurement of red cell concentrations of Li+, in addition to the usual plasma measurement, can be used as an indicator of patient compliance.

Biological Transport, Active↗