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Biomedical subjects

E Singer

Publications and source records attributed to E Singer.

At least 73 records · Page 4Linked to original sources
PubMed1976

Mepiprazole, a new psychotropic drug: effects on uptake and retention of monoamines in rat brain synaptosomes.

The influence of mepiprazole (EMD 16,923), a new pyrazol-ylalkyl-piperazine derivative, on the uptake of 3H-norepinephrine (NE), 3H-dopamine (DA), and 3H-serotonin (5-HT) into rat brain synaptosomes from cerebral cortex, corpus striatum, and hypothalamus was investigated in comparison with several psychotropic drugs, including oxypertine, d-amphetamine, imipramine, desipramine, chlorimipramine, amitriptyline, and chlorpromazine in vitro. Mepiprazole was a relatively weak inhibitor of monoamine uptake and exhibited its strongest action on the hypothalamic 5-HT uptake, being almost equipotent with desipramine (IC50 = 0.9 MUM). Furthermore, the influence of the drugs on the retention of 3H-amines previously taken up by whole rat brain synaptosomes was studied. Unlike the tricyclic antidepressants, mepiprazole as well as oxypertine and d-amphetamine markedly increased the efflux of radioactivity during a 20-min incubation at 37 degrees C at low concentrations (10(-6) to 10(-5) M), whereas at 10(-4) M all drugs greatly enhanced the efflux. The ability of mepiprazole to increase 5-HT concentration at the receptor level by a combination of neuronal uptake inhibition and release is discussed in relationship to the central actions of the drug.

Animals↗
PubMed1976

Replicating psychiatric ratings through multiple regression analysis: The Midtown Manhattan Restudy.

This paper examines three related questions: First, can psychiatrists' judgments be successfully predicted by multiple regression techniques? Second, assuming that they can, are such ratings a valid measure of mental health for the same sample at a later point in time? Third, what is the relation between mental health ratings made in 1954 and such subsequently reported behavioral outcomes as nervous breakdown, mental hospitalization, or seeking professional help for emotional problems? The evidence presented warrants two conclusion. (1) The computer-derived mental health ratings are an adequate substitute for the original ratings. The regression equation accounts for 69 percent of the variance in those ratings; and the computer-derived ratings behave in the same way as the psychiatrists' ratings in relation to other variables. (2) However, neither the psychiatrists' ratings nor the computer-derived ratings are very accurate in predicting subsequent self-reported behavior indicative of mental impairment.

Adult↗
PubMed1976

Sociopsychological factors influencing response to levodopa therapy for Parkinson's disease.

This article examines the effect of a series of physical and sociopsychological variables on the response shown by Parkinson patients to levodopa therapy. Of the ten major variables examined, six measure relatively enduring personality adaptations: suggestibility, passivity, self-expectations, stigma, attitudes toward illness, and the perception of the expectations of others. Four are illness-related characteristics: diagnosis (primary or secondary parkinsonism); the existence of health problems in addition to Parkinson's disease; whether or not the patient was hospitalized at the beginning of treatment; and symptom improvement as rated by the patient's physician. Age, sex, severity and duration of disease, and use of anti-Parkinson drugs in addition to levodopa were controlled in all of the analyses. The effect of levodopa therapy was assessed in four major areas: activity, social participation, depression, and enjoyment of life. Findings can be summarized as follows: Five of the six personality variables do, in fact, modify the amount of social or psychological change shown by Parkinson patients treated with levodopa. The only one which fails to have such an effect is passivity; this may reflect a measurement problem. However, only two of the four illness-related characteristics which were examined made a difference in treatment outcome: diagnosis and symptomatic improvement, as rated by the patient's physician.

Adaptation, Psychological↗
PubMed1976

[Change of a releasing mechanism involved in pre-catching behavior during the development of Salamandra salamandra (L.)].

Preycatching behaviour in salamanders (Salamandra salamandra L.) was studied before (60 larvae) and after metamorphosis (50 juveniles) to find out whether there are differences in releasing mechanisms depending on the developmental stage. Responses to prey dummies of different size, shape and orientation were recorded. With advancing age salamanders respond more selectively, preferring "wormlike" dummies. The releasing mechanism is narrowed down during 10 months after metamorphosis. This is not caused by learning processes.

Animals↗
PubMedDate not supplied

Parameter estimation for a prosthetic ankle.

The mechanical parameters of a model of an energy storage and return ankle prosthesis are estimated for normal level walking by means of an optimization procedure. The walking cycle is divided into six fields, such that the power does not change sign within each field; the transition between successive fields occurs at zero power. The optimal spring stiffness as a function of time, is found by optimizing a quadratic cost function to minimize the difference between the estimated ankle moments and the moments in normal walking. The optimization is subjected to four continuous constraints within each field and to two continuity constraints for the transitions between successive fields. The time-varying spring stiffness and the implications of additional external energy are discussed and are presented as recommendations for the designer.

Ankle Joint↗