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Biomedical subjects

R Spiegel

Publications and source records attributed to R Spiegel.

At least 109 records · Page 6Linked to original sources
PubMed1981

Induction of complement receptor expression in cell lines derived from human undifferentiated lymphomas. II. Characterization of the induced complement receptors and demonstration of the simultaneous induction of EBV receptor.

We have studied the specificity of complement receptors induced by theophylline in 2 cell lines derived from undifferentiated lymphomas, one of Burkitt's type, and compared it to that of complement receptors in other cell types. Both C3b and C3d receptors were induced. The induced C3b receptor differed from the C3b receptor of mature normal lymphocytes, polymorphonuclear leukocytes and the cells of a nodular lymphoma in 2 respects. Firstly, it bound C3b much less avidly (by a factor of several hundred-fold) and secondly, we were unable to demonstrate C4b binding. EBV receptors were induced at the same time as complement receptors, and permitted the conversion of a greater fraction of cells to EBNA positivity after experimental infection with EBV. The induction of receptors was not associated with a change in the fluidity of the plasma membranes and our data do not favor a different orientation of induced receptors within the membrane as compared to receptors of other cell types--a potential explanation for the different specificities. Our findings are consistent with the possibility that the complement receptors of lymphocyte precursors differ from these of mature lymphocytes.

Binding, Competitive↗
PubMed1980

Characterization of ergot and non-ergot serotonin antagonists by prolactin and growth hormone profiles during wakefulness and sleep.

In order to further clarify the involvement of serotonin in the control of secretion of pituitary lactogens, diurnal and sleep prolactin (PRL) and growth hormone (GH) profiles were investigated in healthy subjects treated with ergot and non-ergot serotonin antagonists. A group of 10 subjects received a single oral dose of 2 mg each of pizotifen, methysergide, and the dopaminergic drug bromocriptine as reference substance, in comparison with placebo. Blood was collected at hourly intervals for 6 h. Another group of 10 individuals received either a placebo, 2.5 mg bromocriptine (n = 6) twice daily for 4 days or pizotifen (n = 10) 0.5 mg 3 times daily for 12 days before undergoing EEG recording and blood sampling during night sleep. The diurnal plasma profiles of PRL and GH were not modified by pizotifen, a non-ergot drug. Methysergide and bromocriptine, two ergot derivatives, significantly (P < 0.01 and P < 0.001 respectively) suppressed the basal secretion of PRL throughout the trial and increased plasma GH significantly (P < 0.01). The sleep profile of PRL was not modified by pizotifen but there was a moderate reduction in GH reaching the level of significance (P < 0.02) between hours 1 and 2 of sleep. Bromocriptine suppressed completely PRL secretion throughout the entire sleep period and significantly (P < 0.05) prolonged the secretory profile of GH. The results indicate the presence in the ergot molecule of a dopaminergic moiety responsible for PRL inhibition and GH stimulation. This effect is independent of the serotonin active component of the drug.

Adult↗
PubMed1980

[Effect of high single doses of bromocriptine in schizophrenic patients with elevated serum prolactin levels and extrapyramidal side effects associated with neuroleptic treatment (author's transl)].

The purpose of the present study was to investigate the effect of bromocriptine in single doses of 20 and 30 mg on the unwanted effects most frequently caused by neuroleptics: elevated prolactin levels and extrapyramidal disturbances. 111 chronic schizophrenics were included in the investigations, 58 of them being treated with haloperidol and 53 with chlorpromazine. It was found that a single dose of 30 mg bromocriptine brought about a statistically significant decrease in the prolactin levels of patients treated with haloperidol but produced no more than a downward tendency in patients receiving chlorpromazine (the initial prolactin levels of both groups of patients were equal.) The effect of bromocriptine on EPS disturbances was more marked in the chlorpromazine group, but side effects such as nausea and agitation also occurred more frequently in this group. These results show that there is no correlation between the reduction in prolactin levels produced by bromocriptine and an improvement in unwanted EPS effects. This supports the hypothesis that the effect of neuroleptics on the prolactin secreting cells of the anterior pituitary and their effect on the EPS are mediated by different sets of receptors.

Adult↗
PubMed1980

Central effects of guanfacine and clonidine during wakefulness and sleep in healthy subjects.

1. Three double-blind studies in young normotensive male volunteers were carried out: a study in ten awake subjects, comparing guanfacine 2.0 and 4.0 mg with clonidie 0.15 and 0.30 mg and placebo; and two polygraphic sleep studies each with six subjects, comparing guanfacine 1.0 and 2.0 mg with placebo, and clonidine 0.15 and 0.30 mg with placebo, respectively. 2. In awake subjects, both drugs reduced systolic blood pressure without significantly altering diastolic blood pressure, pulse rate and objective performance parameters. 'Side-effects' such as tiredness, decreased inclination to work, and dryness of the mouth were somewhat more frequent after the higher clonidine dose than after both doses of guanfacine, and peaked 2 h after clonidine but only 4-6 h after guanfacine. 3. Clonidine 0.15 and 0.30 mg given in the evening was followed by a substantial and dose-dependent reduction in rapid eye movement (REM) sleep. Guanfacine 1.0 mg did not alter REM sleep and 2.0 mg of guanfacine had less effect than both doses of clonidine in this respect. Clonidine's effect on REM sleep began after about 2 h, whereas guanfacine's action on REM sleep began 5 h after the dose. 4. Guanfacine and clonidine possess a qualitatively similar pattern of activity with regard to the parameters studied; but the central effects are less pronounced and occur later after guanfacine than after clonidine in equiactive doses.

Adult↗
PubMed1980

On psychotherapy of patients with problems of hostility.

Psychotherapy often involves the person's recognition of the hostility, the role of reaction formation to hurtful situations and relationships, and transferential expression--and for the therapist, countertransference. Generally, underlying hostility is the wish to be free of it, granted the difficulty of some paranoid patients. Ambulatory therapy may be inadequate, and other resources, including hospitalization, may be required. The ethical issue of social responsibility transcending the obligation of confidentiality may arise.

Adult↗
PubMed1979

[A new geriatric battery test].

Both the clinical and the experimental field of geriatrics are in need of an instrument to test the cognitive abilities of people aged 60 and above. By means of a pre-test of the new geriatric test-battery, those abilities, which generally decrease with age, are tested first in order to obtain a testability rating for a particular patient. The geriatric test-battery, which is based on a theory of a 4 dimensional intelligence clearly delineating the differential development of specific cognitive abilities into old age, allows a precise, differentiated assessment of the cognitive abilities of the elderly. Considering the particular characteristics of the old person, the geriatric test-battery was given a new form which minimizes the feeling of being threatened by the test and at the same time maximizes motivation. The geriatric test-battery is pleasant for both the patient and the tester, it is simple to administer, can easily be given to physically impaired or bedridden patients, and is not time consuming.

Aged↗
PubMed1979

Hypnotic efficacy of temazepam: a long-term sleep laboratory evaluation.

1 Temazepam was evaluated in a strictly defined insomniac patient population under sleep laboratory conditions. Two protocols were used: a short-term (26-night) and a long-term (54-night) protocol evaluated the efficacy of the drug administered at night at 15 mg (short-term study) and 30 mg (long-term study), respectively. 2 Temazepam seemed to be both safe and effective at doses of 15 and 30 mg with up to 5 weeks of ingestion. 3 Suppression of slow wave sleep was observed at the high dose, but no suppression of REM sleep, found in studies with other benzodiazepines, was noted. 4 No evidence was found for development of tolerance or rebound effects.

Adult↗
PubMed1978

Longitudinal mixing in pulmonary airways--normal subjects respiring at a constant flow.

We have measured the impulse response of helium and sulfur hexafluoride in the airways of five normal human subjects at a respiratory flow of 400 ml/s. The longitudinal mixing of the inert gases was characterized by the increased volume variance of the expired concentration response. This parameter was measured over the largest possible range of airway penetrations, 30-290 ml. Employing a symmetrical model of the airway geometry, we have computed the values of a mean mixing coefficient from the volume variance data. This mixing coefficient is largest in the large airways and decreases rapidly with increasing penetration; it may be as much as 4,000 times greater than the molecular diffusivity; and it is relatively independent of the inert gas tested, at least up to an airway penetration of 180 ml. These observations are consistent with several preivously proposed mixing mechanisms including axial streaming, turbulent dispersion, and mixing by geometric asymmetry. However, the latter observation appears to rule out the importance of laminar dispersion since mixing by this mechanism is inversely dependent on the molecular diffusivity.

Humans↗
PubMed1976

Self-reports versus sleep laboratory findings in 122 drug-free subjects with complaints of chronic insomnia.

The authors compared the sleep laboratory recordings of 122 drug-free subjects who complained of chronic insomnia with the subjects' estimates of their habitual sleep characteristics and their estimated sleep time on the morning after sleeping in the laboratory. Most subjects consistently underestimated the amount of time they slept and overestimated the amount of time it took them to get to sleep in comparison with laboratory data. All subjects consistently underestimated the number of arousals they experienced. The authors discuss the implications of these findings for the treatment and definition of insomnia and for further research.

Adolescent↗
PubMed1976

Polygraphic sleep studies in rats and humans: their use in psychopharmacological research.

The effects of selected centrally acting drugs on sleep after single administration to rats and humans were studied using polygraphic sleep recording techniques. D-Amphetamine, a stimulant, had similar effects in both species: reduction of total sleep time, of N(non-)REM- and particularly REM (rapid eye movement)-sleep, increased restlessness during sleep. The psychodepressants mesoridazine and, in particular, nitrazepam had relatively little effects on sleep stages. In doses which did not cause side effects they reduced restlessness during sleep. The most typical effect of the antidepressant imipramine was a dose dependent reduction of REM-sleep duration in both species, without impairment of NREM-sleep. The central dopamine agonist, bromocriptin, had little effect on sleep and did not reduce total sleep and REM-sleep. These examples suggest that polygraphic sleep studies are a sensitive and stable method for the study of centrally acting drugs. The specificity of the model is illustrated by its ability to differentiate chemically and pharmacologically different drug classes. The validity of the model, i.e., its ability to allow predictions from the laboratory conditions to the therapeutic situation, varies in different drug classes. Investigations in normal subjects and animals appear to be relevant for the study of CNS-stimulants, whereas for CNS-depressants studies in sleep-disturbed subjects or animals are more likely to provide dependable results.

Adult↗