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Biomedical subjects

S Roux

Publications and source records attributed to S Roux.

176 records · Page 10Linked to original sources

Antiapomorphine and locomotor effects of neuroleptics in rhesus monkeys.

Intramuscular injections of apomorphine (1 mg/kg) cause marked behavioral effects in rhesus monkeys including hyperactivity, repetitive stereotyped movements, chewing, tongue movements, licking, biting and vocalization. These effects occur within minutes of the injection and last 90-100 min. The antiapomorphine and locomotor depressant activity of chlorpromazine, haloperidol, MD 790501, sultopride and thioridazine, injected IM 1 hr before apomorphine, were assessed using a standardized rating procedure. All compounds antagonized the effects of apomorphine but differed in terms of potency and their relative effects on locomotor activity. The experimental compound MD 790501, a new benzamide derivative, was not only the most potent compound tested but, compared with its antagonism of apomorphine, caused the least marked depression of locomotor activity.

Animals↗

[Various factors affecting the onset of paroxysmal nocturnal interictal activities in primary generalized epilepsy in adults].

The relationships between the states of vigilance and the interictal EEG, paroxysmal activities (PA) were studied in 20 adults with generalized primary epilepsy. Each patient was submitted to 1-5 nocturnal polygraphic recordings. Sleep and waking modify the PA densities: 8 patients had a waking PA increase, 7 a sleep PA increase and 5 exhibited no differences of PA density between sleep and waking. Within these groups there was also an influence of slow wave sleep stages on PA densities. The function of auto-correlation of PA did not exhibit any periodicity even after correction of the effects of the states of vigilance. In patients monitored several nights the evolution of the PA densities during the successive sleep cycles throughout the night did not usually reveal a clear and stable pattern.

Adolescent↗

Event-related potentials evoked by sensory stimulation in normal mentally retarded and autistic children.

Evoked potentials (EPs) and slow potentials (SPs) were recorded during two sessions of sound (S) and light (L) conditioning (habituation: S alone; conditioning: coupling of SL; extinction: S alone after SL series). 125 children from 0 to 15 were examined: 82 exhibited signs of autistic behaviour and/or mental retardation; 43 were normally adapted. Two studies were performed. The first was an analysis of relationships: 65 clinical characters were noted for each child with behaviour scales and psychometric tests, 88 electrophysiological data were measured on averaged tracings. The second compared with t and chi 2 square methods the electrophysiological data of 3 groups clinically defined for age and typical syndrome. Results of the two studies supplemented each other. From the clinical point of view 3 major groups appeared: (1) autism, (2) mental retardation, (3) normal adaptation. From an electrophysiological point of view 2 major groups could be defined: (1) few conditioned EPs with small amplitude, generalized conditioned SPs, small unconditioned EPs, generalized unconditioned SPs, conditioning 'to time'; (2) many conditioned EPs, many conditioned rhythmic potentials, absence of generalized SPs, many localized vertex negative SPs (CNVs), large unconditioned EPs, no conditioning to time. Some differences were observed in generalized SPs, small and positive in mentally retarded children, negative or positive in autistic children. EP and SP data clearly help to differentiate pathological groups from a normal group but are insufficient to distinguish the autistic from the mentally retarded children.

Adolescent↗

Event-related slow potentials evoked during ankle jerk conditioning in wakefulness and NREM sleep.

Slow cortical potentials related to the ankle jerk and to its conditioning were studied in 40 adults while awake and during NREM sleep. A weak sound (S) was used as conditioned stimulus, while the ankle jerk, evoked either by Achilles tendon percussion (P) or by electrical stimulation of the sciatic nerve (H), served as unconditioned or 'imperative' stimulus. During waking, responses to simple stimuli (S, P, H) were mostly negative. During S-P and S-H pairs, responses to S were mainly negative, resembling the CNV, while these to P or to H became mostly positive, like the CNV resolution or the positive phase of the motor potential. During NREM sleep, responses to simple as well as to paired stimuli showed mostly a biphasic (negative-positive) morphology resembling the K complex. The conditioned slow potential changes obtained by pairing a sound with the ankle jerk therefore seem to be abolished during NREM sleep. This absence of conditioning can be related to the absence of habituation during NREM sleep. In 35% of the cases, however, positive slow waves were evoked by paired sounds during sleep. The possible significance of these phenomena is discussed.

Adult↗

[Measurement of homovanillic acid in urine of newborns and in older children].

In this study, the urinary H.V.A. of new borns and of older children was measured. The urinary H.V.A. titer of the new borns was found to be significantly greater than in older children. Moreover the increase is more pronounced when those infants are born prematurely. Former studies have shown that the metabolism of central nervous system catecholamine reflected by the urinary titers of H.V.A. is as accurate as titers measured in the CSF. Recently several authors have found increased titers of urinary H.V.A. in autistic children. It is therefore possible that the elevated urinary H.V.A. titers in the new born are due to an immaturity of the dopaminergic structures. Blocking these structures provokes an accelerated catecholamine turnover, thereby increasing the levels of catecholamines metabolites (most notably H.V.A.).

Adolescent↗

Chimeric receptors as a tool for luminescent measurement of biological activities of steroid hormones.

Some applications of chimeric cellular models are presented to study the biological activities of steroid hormones. We have used several chimeric constructs encoding the DNA binding domain of Gal4 yeast protein fused to the hormone binding domain of various steroid receptors (MR, PR, GR and ER). Interactions of these chimeric receptors with a 17-mer DNA sequence, specific for Gal-4, control expression of the firefly luciferase as a reporter gene. Stable transfected cell lines expressing the firefly luciferase under the control of different steroids were established and an efficient and easy sub-cloning was allowed with the help of an imaging system using a single-photon-counting camera. In the cell lines obtained, the bioluminescent response can be easily measured and thus used to measure specific biological activities of steroid agonists or antagonists. We observed that the responses are effector-concentration-dependent and their biological activities will be compared to those of native receptors.

Animals↗

Cortical evoked potentials as indicators of auditory-visual cross-modal association in young adults.

Auditory evoked potentials (AEPs) were studied from scalp locations Cz and Oz on 37 adults aged 20-22 years during sensori-sensorial association of a weak sound (S) and a strong flash of light (L). After sound alone repetition (habituation), S-L association modified AEP: first, it caused a generalized orienting response expressed as increasing of Cz and Oz amplitude AEPs. Then, this pattern gave way to an activation limited to the Oz lead: the increase of amplitude was then concomitant with shortened latencies when compared to sound-alone-habituated responses. Inter-individual differences were observed since these occipital modifications were recorded only on 26 subjects. The other 11 subjects did not exhibit any occipital modifications following S-L association. For them, the main modification was a strong decrease of Cz AEP induced by S-L association. These two groups also differed in their capacity to ignore irrelevant stimuli which is higher in the first group (AEP amplitude habituation with sound-alone repetition) than in the second one (no AEP habituation).

Adult↗

Prospects for exosomes in immunotherapy of cancer.

Exosomes are nanometer sized membrane vesicles invaginating from multivesicular bodies and secreted from epithelial and hematopoietic cells. They were first described "in vitro" but vesicles with the hallmarks of exosomes are present in vivo in germinal centers and biological fluids. Their protein and lipid composition are unique and could account for their expanding functions such as eradication of obsolete proteins, antigen presentation or "Trojan horses" for viruses or prions. Exosome secretion could be a regulated process participating in the transfer of molecules inbetween immune cells. Despite numerous questions pertaining to their biological relevance, the potential of dendritic cell derived-exosomes as cell-free cancer vaccines is currently being assessed. This review will summarize the composition and formation of exosomes, preclinical data, Phase I trials and optimization protocols for improving their immunogenicity in tumor bearing patients.

Animals↗

[Early signs of autism and family films: a new study by informed evaluators and those unaware of the diagnosis].

Since the initial individualization of infantile autism by Kanner, subsequent work has attempted to define the age at which disorders appear, their symptomatology and their specificity. Initially, retrospective studies based on questionnaires and interviews with parents were conducted in order to determine the age of at which the first signs appeared. Combined with interviews, clinical observations have provided incontestable aid for describing the early signs of autism. The study of home movies taken by parents before their infant's disorders were recognized has led to a new approach to the initials signs of autism. Our study is a continuation of work in our Child Psychiatry Unit under way since 1984. The aim of this work is the symptomatological and comparative analysis of home movies of 14 autistic and 10 normal infants, during the first two years of their life. Each film was scored for the 0-8, 9-17 and 18-24 month periods. Based on the use of the Infant Behavioral Summarized Evaluation (IBSE), this study confirms prior data and also shows the emergence of very early disorders, perceptible within the first few months even by blind evaluators: a docile baby, showing no overt manifestations, not seeking contact, with an absence of pre-language. Even so, the results require caution when interpreting for methodological reasons which are discussed.

Autistic Disorder↗

[Rett syndrome and autism. Early comparative evaluation for signs of autism using family movies].

Rett's syndrome progresses in 4 stages: the first signs of the disorder appear after a period of 6 to 7 months, during which development is considered to be normal. This asymptomatic period is apparently an essential criterion of the diagnosis, but some parents have reported some prodromes. In stage II of the disease (before 3 years), signs common with autism dominate the clinical picture and the diagnosis of the latter was often formulated. Our working hypothesis is that the pedopsychiatric analysis of home movies of young girls with Rett's syndrome, taken by the parents before the age of 2, may be able to show early clinical signs. The present study involved examining home movies of children subsequently diagnosed as having Rett's syndrome (n = 9) in comparison to those of autistic (n = 9) and normal (n = 9) children, using semiological evaluation tools (IBSE, BFE). The persons scoring were not advised of the diagnosis. The observations were thus situated before the disorders and/or at the time of their appearance. The study confirms the asymptomatic interval between birth and the first signs of the disease, it defines the mode of onset and shows the disturbance of certain functions such as intent and imitation, more pronounced in Rett's syndrome children between 12 and 18 months. At this age, it also enables Rett's and autistic children to be differentiated on the basis of the different involvement of the "cognition" function and unusual posture, more pronounced in these girls. It does not, however, differentiate Rett's from autism between 6 and 12 months and it is thus not surprising that at this stage the diagnosis of rett's syndrome or autism may be a source of confusion.

Adolescent↗

[Further clinical evaluations elicited by functional biological investigations in childhood autism].

As childhood autism is usually considered as a developmental disorder, complete assessment of each patient requires non only clinical examination but various biological investigations: EEG and evoked potentials recordings, biochemical dosages and sometimes, cerebral blood flow measures, molecular biologic explorations.... These investigations help to understand neurophysiological dysfunctionings which underly different autistic syndromes. It therefore seems necessary to develop quantified clinical tools which could allow closer matching between clinical evaluations and biological numerical data. These complementary evaluations must be both simple and quick to perform in medical practice, as they are added to an already heavy clinical examination. The main tools used in our bioclinical Department are described here. For each child, psychiatric, pediatric and neurological examination was performed. Different scales were progressively elaborated and validated to complete and precise behavioral parameters. Attention and perception were evaluated by a Behavior Summarized Evaluation (BSE) scale, association and imitation by appropriate scales, language by the Pre-Verbal Behavior Summarized Evaluation (PV-BSE) scale, early symptoms by the Infant Behavior Summarized Evaluation (t-BSE) scale. The main neurophysiological dysfunctionings were grouped in a Behavioral Functional Inventory (BFI). Clinical genetic data were scored in a summarized assessment carrying both on the antecedents and on the somatic abnormalities. The completed clinical data were gathered in a Quantified Multidimensional Assessment (QMA), with four axes: socialization, communication, cognition and neurological observation. These clinical evaluations provide behavioral details that can be integrated into a bioclinical database and give an objective approach to the heterogeneity of autism. They invite both clinicians and biologists to deepen the description of individual profiles which allow better understanding of physiopathological mechanisms in autistic children.

Attention↗