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Biomedical subjects

R Tissot

Publications and source records attributed to R Tissot.

At least 55 records · Page 3Linked to original sources
PubMed1986

Differential effects of acute and chronic administration of haloperidol on substance P and enkephalins in diverse rat brain areas.

Rats received 10 mg/kg/day of haloperidol during up to 9.5 weeks. Substance P, Leu- and Met-enkephalins, were studied in brain using immunohistochemical methods. Haloperidol modified the peptides immunoreactivity in most brain areas. The time necessary to observe the effects of haloperidol on the peptides varied individually, depending on the peptide and the brain area. Moreover, inversions of these effects were often observed, generally occurring between in 5th and 7th day of drug administration. Substance P was increased after haloperidol in the hypophysis, a finding hereto not described. This descriptive study identified none of these three peptides as a single and specific target for dopaminergic receptor blockade. Methodological issues in evaluating the effects of neuroleptics on brain peptides are discussed.

Amygdala↗
PubMed1986

In vitro effects of ionophores and inhibitors of main sodium and calcium movements on tyrosine and tryptophan transport by human erythrocytes.

Peripheral models using blood cells might be biochemical markers in various psychiatric illnesses. In previous papers we reported a deficit of tyrosine and tryptophan transport in red cells incubated in plasma from depressed patients. In the present study we investigated the role played by sodium and calcium in these transports by using inhibitors and ionophores of the main movements of these electrolytes. We also studied the contribution of phloretin-sensitive countertransport, which has been described as low in psychiatric conditions.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1985

[The speech of hebephrenic patients (maladjustment between assimilation and accommodation)].

Previous studies indicate that schizophrenic thought processes show a disturbance in the balance between assimilation and accommodation, as Piaget uses these terms. The authors postulated that this phenomenon could also account for the typical language disorders of hebephrenics, particularly semantic slippage. Every fourth word was deleted from linguistic material produced by eight controls and thirteen hebephrenics (Silverman). Three judges were then asked to fill in the blanks. The deleted words used by the subjects were compared with the replacement words chosen by the judges. The comparison revealed such disorders in hebephrenic speech as semantic alteration (metaphorical and metonymic) of the linguistic tropic type and syntax disorders including inhibition of the expansion of phrases introduced by functional monemes (morphemes), whether primary or secondary. These observations confirm those of other authors, more especially those of Roch Lecours et al. On the basis of Martinet's functional linguistics, Chomsky's generative grammar and Piaget's cognitive psychology, the authors conclude that the psychopathology underlying hebephrenic speech is a disturbance of language rather than of parole and that hebephrenic syntactical distortions are linked to the disturbance in the balance between assimilation and accommodation characteristic of schizophrenic thought processes.

Adult↗
PubMed1984

DSIP in the treatment of withdrawal syndromes from alcohol and opiates.

The hypothesis for this therapeutic use of delta sleep-inducing peptide (DSIP) was based on several animal studies conducted by Tissot. He showed that morphine, alcohol, pentobarbital as well as DSIP, when injected directly into the bulbo-mesencephalo-thalamic recruiting system, induced slow-wave sleep with numerous spindles. In all cases, this effect was reversed by Naloxone. Thus, it has been postulated that DSIP possesses an agonistic activity on opiate receptors and might be of value in the treatment of withdrawal syndromes. Therefore, DSIP was administered intravenously to 107 inpatients presenting with symptoms of alcohol (n = 47) or opiate (n = 60) withdrawal. The assessment of effect was based on the clinical evaluation by the physician and the nursing staff. Approximately 13% of the patients from the first and 22% from the second group did not fulfil the requirements for the evaluation of treatment. In, respectively, 97 and 87% of opiate and alcohol addicts, the clinical symptoms and signs disappeared after DSIP administration or improved markedly and rapidly. Anxiety, however, was slower to decrease. On the average, the clinical symptomatology had a more prolonged course and a higher number of DSIP injections were required for opiate addicts than for alcoholics. Tolerance to the DSIP treatment was good, aside from headaches reported by a few patients.

Adult↗
PubMed1984

[Activation of the diffuse thalamic projection system by GABA-ergic stimulation].

Since Hess's first conclusive experiment of a sleep-inducing effect by median thalamic low-frequency stimulation, many studies have shown that this is due to the activity of the thalamic diffuse projection system. Activation of this system results in an augmentation of thalamo-cortical IPSP. Benzodiazepines, generally considered as GABAergic mediators, increase the system's activity. Therefore it seemed reasonable to postulate a GABAergic transmission within this system. In support of this hypothesis, micro-injections of SL 75.102 (a specific GABAergic agonist) in the rabbit thalamus increase the spindle-rich slow wave sleep, producing a sleep graph similar to those induced by anesthetics. When injected intravenously to rabbits, at doses between 80 and 300 mk/kg, SL 75.102 shows potent anesthetic qualities.

Animals↗
PubMed1984

[Choice of symptoms in neuroses. Psychosomatic syndromes].

We think that we have collected a certain amount of arguments in support of the following hypothesis: Without assuming if it is in itself the cause of neuroses, the way of being and of thinking in this world, characteristic of our times' positivistic technico-industrial culture seems to promote a more or less artificial and unconscious anti-anxiety behaviour leading to the psychosomatic syndromes. This way of being in the world and of thinking it is symptomatic of a discrepancy between the exogen (primacy of assimilation) and the endogen (primacy of accommodation) assimilation/accommodation balance. The non-decoupling of the exogen and endogen accommodation leads to a rigid content of concepts and limits the mind process to consider only the materially possible, leading to a regressive causality. Its' ultimate term is the object in which the essence includes the existence, the "causa sui" that is none other than the patient's body. Inability to take into account what is structurally possible makes it difficult to approach the notions of chance and of great numbers, proceeding on to apprehend the time in a way akin to Aristoteles', where the future is reduced to chance. This type of thinking limits the world's understanding to what is materially possible. Outside this, just everything is possible, including the possible the occult sciences account for.

Acculturation↗
PubMed1983

Delta sleep-inducing peptide in the rat brain: an immunohistological microscopic study.

The authors have developed a method which makes it possible, for the first time, to visualize the delta sleep-inducing peptide in histological preparations and study it under the light and fluorescence microscope. Their research builds on Monnier 's discovery, in 1963, of a humoral hypnogenic factor in rabbits which was subsequently isolated and identified as a nonapeptide. Dubbed delta sleep-inducing peptide (DSIP), this factor was later detected in rat brain by radioimmunoassay but has eluded histological visualization until recently. In their work, the authors used an anti-DSIP antiserum suitable for immunohistological purposes. Two indirect immunohistological methods (PAP and immunofluorescence) allowed them to visualize, for the first time, structures containing specific DSIP-like immunoreactivity in some areas of the rat brain: indusium griseum, nucleus septi lateralis, hippocampus, striae longitudinales of Lancisi , bandeletta diagnalis of Broca, pallidum, hypothalamus, hypophysis and neocortex. Some DSIP pathways seem likely: (1) indusium griseum - striae longitudinales - hippocampus; (2) nucleus septi lateralis - striae longitudinales , bandeletta diagonalis - hippocampus; (3) neurons of the pyramidal layer of the hippocampus - gyrus dentatus; (4) pallidum - commissura of Ganser - hypothalamus. The possible correlations between DSIP neurons and neurons with other neurotransmitters are discussed. In preliminary clinical trials, DSIP has shown promise for the treatment of insomnia and the opiate and alcohol withdrawal syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Successful treatment of withdrawal symptoms with delta sleep-inducing peptide, a neuropeptide with potential agonistic activity on opiate receptors.

It has been postulated that delta sleep-inducing peptide (DSIP) possesses an agonistic activity on opiate receptors and might be of value in the treatment of withdrawal syndromes. To test this hypothesis, DSIP (25 nmol/kg) was injected intravenously as sole treatment to 67 patients presenting withdrawal symptoms (28 from ethyl alcohol, 39 from opiates). 27% of the patients were lost or unsuitable for evaluation. From the 49 evaluable patients, DSIP produced a beneficial effect in 48 (22 alcoholics and 26 from 27 opiate addicts), with an immediate onset of action, a good and lasting suspension of the somatic symptoms and signs. Anxiety resolved more slowly, within hours. No major side-effect occurred. DSIP offers a new physiologically-based approach for the treatment of established withdrawal syndrome.

Adult↗
PubMed1982

Exchange mechanism of tyrosine between plasma and red blood cells in normal subjects and psychiatric patients.

The saturable mechanism of tyrosine (TYR) uptake by the membrane of red blood cells incubated at 37 degrees C has been studied in normal subjects and psychiatric patients. This uptake is markedly inhibited by incubation at 0 degree C, and weakly inhibited by iodoacetic acid and ouabain. The uptake of TYR is significantly lower in unipolar- and bipolar-depressed patients, and significantly higher in schizophrenics compared to normal controls. These results indicate a possible disturbance of functional capacity of membrane transport in some psychiatric diseases.

Biological Transport↗
PubMed1981

[Opiate receptors and sleep. II. Effects of micro-injection of ethyl alcohol and pentobarbital in the median thalamus, periaqueductal gray matter and nucleus of the tractus solitarius of the rabbit (author's transl)].

There is an analogy between sleep EEGs produced by microinjections of morphine in the bulbo-mesencephalo-thalamic recruiting system and EEGs seen during anesthetic-induced sleep. Many studies in the last 10 years have claimed cross-tolerance and cross-dependence between opiates and ethyl alcohol. Opiates, ethyl alcohol and pentobarbital have many common metabolic actions in the central nervous system. Like morphine, microinjections of optimal equimolar doses of ethyl alcohol and pentobarbital in the bulbo-mesencephalo-thalamic sleep-inducing system of the rabbit produce sleep EEGs with abundant fast activity, which is blocked by naloxone (2 mg/kg i.v.) or by microinjections (160 micrograms) into the same structures. However, there is neither binding nor displacement by naloxone of ethyl alcohol or pentobarbital from the opiate receptor. It is thus probable that, via an as yet unknown mechanism, ethyl alcohol and pentobarbital promote the release of endorphins or peptides, which are specific ligands of all or some opiate receptors.

Animals↗
PubMed1981

Antidepressants and serotonin neurons of the raphe.

Reserpine + nialamid administration to the rat induces a strong yellow fluorescence of the neuronal bodies of the raphe, due to serotonin (5-HT) accumulation. Under these conditions, administration of clomipramine (an antidepressant drug acting preferentially on 5-HT-mediated neurons) induces a decrease of intraneuronal fluorescence and its interneuronal diffusion. On this pattern we administered new antidepressant drugs which act on 5-HT neurons in a much more intensive way than clomipramine (fluvoxamine, clovoxamine, LM 5008, citalopram, Ro 11-2465). To varying degrees, we observed in the raphe, in addition to a decrease in intraneuronal fluorescence and interneuronal diffusion, the presence of a yellow fluorescence in capillary walls. It seems that under these antidepressants, 5-HT, which is outside neuronal bodies because of uptake blockade, is partly caught by the capillary walls. In these walls rich in monoamine oxydase, 5-HT would be catabolized, 5HIAA dispersed in the blood and thus, this 'capillary effect' could correspond to a loss of 5-HT in the raphe. Antidepressant drugs preferentially acting upon noradrenaline (NA) neurons do not, in this model, induce analogous phenomena in NA cell bodies of the locus coeruleus. So the 'capillary effect' differentiates antidepressant drugs acting specifically on 5-HT or NA neurons. It may be considered together with other parameters which also indicate asymmetries on the modes of action of antidepressant drugs, such as effects on monoamine turnover (increase for NA and decrease for 5-HT) and on receptor sensitivity (decrease for NA and increase for 5-HT).

Animals↗
PubMed1981

[Opiate receptors and sleep. III. Effects of microinjections of DSIP (delta-sleep peptide) in the median thalamus, Periaqueductal gray matter and nucleus of the tractus solitarius of the rabbit (author's transl)].

In the rabbit, microinjections of DSIP (delta-sleep peptide) at optimal doses in the median thalamus, periaqueductal gray matter (22.5 nmol), and nucleus of the tractus solitarius (15.0 nmol) produce slow-wave sleep with abundant recruiting spindles. As is seen with morphine, this effect is blocked by naloxone (160 micrograms intracerebrally; i.c.). At least in the rabbit, DSIP is probably a neurotransmitter or a neuromodulator of the bulbothalamic system inducing slow-wave sleep and particularly recruiting spindles. It is likely to restore slow-wave sleep after supraoptimal awakening i.c. microinjections of morphine.

Animals↗