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Biomedical subjects

M Lichtsteiner

Publications and source records attributed to M Lichtsteiner.

36 records · Page 2Linked to original sources
PubMed1985

3H-Imipramine binding sites in platelets of hospitalized psychiatric patients.

The density of platelet 3H-imipramine binding sites has been proposed as a biological marker in psychiatry. We report the range of platelet 3H-imipramine binding in 55 psychiatric patients and 11 control subjects. All blood samples were withdrawn at 2300 h (on the day of hospital admission for patients). With the use of a slight modification of a previously described 3H-imipramine binding method, a mean B max of 1,510 fmole/mg protein (range: 390-5,560; median: 1,450) and a mean Kd of 2.0 nM (range: 0.6-17.0; median: 1.4) were determined for psychiatric patients. For the controls, a mean B max of 1,590 fmole/mg protein (range: 870-2,570; median: 1,440) and a mean Kd of 1.4 nM (range 0.8-2.4; median 1.4) were determined. When patients were subdivided based on ICD-9 psychiatric diagnoses, no significant differences between distinct subgroups of psychiatric patients with respect to B max or Kd values for platelet 3H-imipramine binding could be established. Similarly, no significant difference between psychiatric patients and controls was obtained.

Adolescent↗
PubMed1984

3H-imipramine and 3H-cyano-imipramine binding in rat brain tissue: effect of long-term antidepressant administration.

3H-imipramine and 3H-cyano-imipramine binding was determined in brain homogenates of rats which had been treated for 21 days with imipramine or desimipramine. When compared to control animals, long-term administration of these antidepressants did not induce any alteration in the maximal number of 3H-imipramine or 3H-cyano-imipramine binding sites. However, a transient increase in the apparent dissociation constant was observed. Such findings are discussed in respect to previous studies, which have been highly contraversial.

Animals↗
PubMed1983

Individually housed rats exceed group-housed animals in rotational movements when exposed to a novel environment.

Individually and group-housed rats of both sexes were compared in respect to spontaneous rotational movements when exposed to a novel environment. Thereby, individually housed animals showed a higher number of rotational movements than group-housed controls. During an L12:D12 cycle, such movements occurred most frequently at the beginning of the dark phase, when locomotor activity was highest. It is assumed that these rotations are part of the hyperreactivity toward a novel environment induced by long-term individual housing.

Animals↗
PubMed1983

Regional distribution of [3H]imipramine binding sites in the CNS of Roman high and low avoidance rats.

The high affinity binding of [3H]imipramine to membranes was compared in 7 brain regions from two psychogenetically selected rat lines (RHA/Verh, RLA/Verh). A significantly higher binding in RHA/Verh rats, as compared to RLA/Verh rats, was found in cortex and striatum. All other regions, except hypothalamus, showed a trend in the same direction (RHA/Verh greater than RLA/Verh). In the hypothalamus, however, [3H]imipramine binding for RLA/Verh rats significantly exceeded that found in RHA/Verh animals.

Animals↗
PubMed1983

Instant shift from continuous flow assistance to paracorporeal diaphragm type pulsatile assistance.

Experiments were conducted implementing a special technique for shifting instantaneously from continuous flow to pulsatile flow assistance by using the assistant heart and obtaining the following results: Within only a few minutes, the shift could easily be made from one type of flow assistance to another on calves with normal hearts. In the 10 calves in which ventricular failure was produced, this instantaneous shift from continuous to pulsatile flow assistance brought about remarkable improvements in their hemodynamics. At the occurrence ventricular fibrillation in 6 of the calves, the return to sinus rhythm was possible with aid of this shift mechanism.

Acute Disease↗
PubMed1982

Behavioural comparisons between individually- and group-housed male rats: effects of novel environments and diurnal rhythm.

Individually-housed rats, when compared with group-housed controls, have been previously shown to be hyper-reactive when exposed to an openfield at the beginning of the dark-phase; this was not due to elevated spontaneous activity. In the present experiments locomotor and rearing activities were determined immediately after exposing animals to a novel environment, and after 6 and 24 h of habituation to the test-environment. Additionally, after 24 h of adaptation, animals' responses towards a modification of the test-environment were examined. Four parallel experiments were carried out, each starting at a different time in the light/dark cycle. Individually-housed rats were hyper-reactive in novel environments and showed a slower habituation at all time points tested. Part of behavioural parameters show clearcut day/night variations, but differences between individually- and group-housed rats do not seem to be influenced by the time of day.

Animals↗
PubMed1982

Different reaction patterns in individually and socially reared rats during exposures to novel environments.

Individually and group-reared male rats were behaviourally compared after various periods of different housing, (i) during a first exposure to the new environment, and (ii) after habituation (two repetition trials) to the situation, during a fourth exposure in a slightly modified test-box. Compared to group-housed controls an elevated locomotor activity upon the first exposure and a reduced reaction in response to the slight modifications were found in individually housed rats.

Aging↗
PubMed1981

3H-Diazepam binding sites in Roman high- and low-avoidance rats.

The binding of 3H-diazepam to membrane benzodiazepine receptors was examined in 2 psychogenetically selected lines of rats, which differ according to the selection criterion in avoidance behaviour (RHA/Verh greater than RLA/Verh) and, in addition, in emotionality (RHA/Verh less than RLA/Verh). RHA/Verh rats tended to show higher specific diazepam binding in all CNS-subregions when compared with RLA/Verh animals. Significant differences were found in the cortex, striatum, hippocampus, thalamic region and pons-medulla. These results reinforce the contention that a system involving benzodiazepine receptors may play a role in emotional behaviour.

Animals↗
PubMed1978

Specific in vivo binding of d-LSD in rat brain.

A reproducible in vivo d-LSD binding method in rat brain is described, with high affinity (Kd of 5 pmoles/g wet wt), stereospecificity (d- vs. 1-LSD) and regional selectivity. It may be a useful adjunct to in vitro methods for measuring changes in turnover at the synaptic level related to the intact receptor.

Animals↗
PubMed1977

Diurnal and seasonal variations in human platelet serotonin in man.

Platelet serotonin (5-HT) was found to be an individually constant parameter correlating with the uptake of exogenous 5-HT. A pronounced diurnal pattern of 5-HT, with a minimum in the afternoon and higher values in the morning and evening, was similar to the diurnal variations in plasma free tryptophan. Platelet 5-HT was significantly higher at 8 a.m. than 4 p.m. in spring but no longer in autumn, and was similar in both men and women. It appeared that peripheral diurnal variations in 5-HT were opposite in phase to the central 5-HT rhythm.

Adult↗