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Biomedical subjects

J Volavka

Publications and source records attributed to J Volavka.

At least 109 records · Page 6Linked to original sources

Naloxone, tardive dyskinesia, and endogenous beta-endorphin.

The subjects were 13 psychiatric inpatients with tardive dyskinesia. Each subject participated in two sessions. Either naloxone (10 mg) or placebo was administered intravenously during each session. In a subset of subjects (n = 7), blood samples for beta-endorphin were drawn before and at 30 and 60 minutes after the injection. The Abnormal Involuntary Movement Scale was administered before and at 10, 20, 40, 60, 120, and 360 minutes after the injection. Double-blind procedures were maintained throughout the experiment. Neither naloxone nor placebo had any appreciable effect on the involuntary movements. Naloxone elicited a significant increase in the plasma beta-endorphin.

Adult↗

EEG antecedents of thievery.

In Gothenburg studies using clinical and electroencephalographic techniques have been undertaken continuously since 1958 on a large number of individuals of all ages. All individuals studied were without impairment to the central nervous system, according to a number of well-defined defined clinical criteria, and were termed normal. The term "normal" is used primarily because it is short. As part of the continued investigation, information has been gathered from social bureaus in Gothenburg and from federal registers. It was observed that youths and children who were found guilty of theft showed EEG abnormalities of some kind (in the EEGs taken several years earlier) statistically significantly more often than other youths and children belonging to our normal material. Among the characteristics discovered by EEG can be noted paroxysmal activity during sleep, slow alpha activity and spectral-analytical measurements corresponding to lower EEG ages than the individuals' actual ages.

Adolescent↗

Effect of piracetam on EEG spectra of boys with learning disorders.

Piracetam was compared with placebo in a double-blind cross-over study of 30 learning disabled boys. Power spectral analyses revealed that piracetam caused a decrease in the amount of delta activity and an increase in the average EEG frequency. This result is in agreement with those obtained by other workers in adult patients. Some clinical effects of piracetam may be mediated by increased alertness and/or decreased fatigue.

Adolescent↗

Effects of caffeine on resting EEG and response to sine wave modulated light.

A double blind, placebo controlled study was designed to assess transient caffeine effects on spontaneous and evoked brain activity in man. Twelve normal males received 200 mg caffeine citrate or placebo on separate occasions. EEG from left and right occipital regions was recorded in the absence of stimulation and during the response to sine wave modulated light (SML). The photic stimulation frequencies were 5, 10, 15, 18 and 24 c/sec. EEG power at frequencies corresponding to fundamental and selected harmonics of stimulation frequencies was obtained. The time course of response to SML was studied over a period of 2 min. Caffeine reduced the EEG power under resting conditions and during SML stimulation. This reduction was statistically significant at 10 and 15 c/sec. At 24 c/sec, caffeine reduced the fundamental SML response, but not the resting EEG power. Evaluation of the SML response time course did not reveal any consistent tendencies. It appears that the response is sustained in a stable way over the period of 2 min.

Adult↗

Naloxone fails to affect short-term memory in man.

The effects of naloxone on memory were studied in 26 healthy male volunteers. Either placebo, or 10 mg, or 20 mg of naloxone was given iv on separate occasions. Ten minutes after each injection, the subjects listened to 8 lists of words (10 words on each list). Immediate recall, delayed recall, and delayed recognition were not affected by naloxone within 60 minutes of its administration. These results provide no support for the hypothesis that edorphins play a role in the short-term auditory memory in man.

Adult↗

EEG and other effects of naltrexone and heroin in man.

This paper reviews older results on EEG and behavioral effects of heroin and opiate antagonists in exaddicts, and presents new findings on the effects of naltrexone in men who have never been addicted. Ten normal volunteers were given on three separate occasions placebo, 50 mg or 100 mg of naltrexone. The average alpha frequency was significantly slower after naltrexone than after placebo. Naltrexone elicited a significant reduction of breathing rate and oral temperature. Those results indicate that naltrexone does not act as a pure narcotic antagonist in non-addicted men.

Auditory Threshold↗

Endorphins, dopamine, and schizophrenia.

The theory that alterations of dopaminergic synaptic transmission may play a role in the pathogenesis of schizophrenia is widely accepted. A more recent theory links the endorphin system to the etiology of schizophrenia. We propose that these two theories may be combined into a single model. Recent neurochemical and pharmacological findings have indicated close functional relationships between the endorphin and dopamine systems. Endorphins modulate dopaminergic synaptic transmission by exerting both presynaptic and postsynaptic effects. On the molecular level, this modulation may involve the activity of nucleotide cyclases and protein phosphorylation systems. Thus, the dopaminergic neuronal hyperactivity, currently believed to be related to schizophrenia, may be caused by a primary alteration in the endorphin system. Several hypotheses about the nature of that alteration have been advanced and tested in therapeutic experiments with schizophrenic patients. These experiments have not yet yielded definitive results.

Antipsychotic Agents↗

Profile of Mood States: the factors and their physiological correlates.

Spontaneously occurring mood states and various physiological indices were evaluated on three occasions in a group of eight healthy males. Results reveal that significant positive correlations exist among five of the six factors comprising the Profile of Mood States (POMS). This finding is related to previous research on the POMS and varied methodologies utilized in those reports. Reliable positive correlations of the POMS factors Depression and Tension with heart rate and diastolic blood pressure were obtained. The Anger factor of the POMS also correlated positively and significantly with heart rate. These findings are discussed in terms of the relationship between POMS factors and anxiety.

Adrenocorticotropic Hormone↗