Inhibition of the membrane repair protein annexin-A2 prevents tumor invasion and metastasis

Cancer cells are exposed to major compressive and shearing forces during invasion and metastasis, leading to extensive plasma membrane damage. To survive this mechanical stress, they need to repair membrane injury efficiently. Targeting the membrane repair machinery is thus potentially a new way to prevent invasion and metastasis. We show here that annexin-A2 (ANXA2) is required for membrane repair in invasive breast and pancreatic cancer cells. Mechanistically, we show by fluorescence and electron microscopy that cells fail to reseal shear-stress damaged membrane when ANXA2 is silenced or the protein is inhibited with neutralizing antibody. Silencing of ANXA2 has no effect on proliferation in vitro, and may even accelerate migration in wound healing assays, but reduces tumor cell dissemination in both mice and zebrafish. We expect that inhibiting membrane repair will be particularly effective in aggressive, poor prognosis tumors because they rely on the membrane repair machinery to survive membrane damage during tumor invasion and metastasis. This could be achieved either with anti-ANXA2 antibodies, which have been shown to inhibit metastasis of breast and pancreatic cancer cells, or with small molecule drugs.

Muscle-only versus chimeric musculocutaneous gastrocnemius pedicled flap in complex orthoplastic reconstructions of the knee region: A retrospective study

BACKGROUND

The knee region represents a challenging area of soft tissue reconstruction. Specifically, in the context of total knee arthroplasty (TKA) or following high-energy trauma with fractures and hardware fixation, soft tissue defects can expose critical structures such as joint, bone or tendon, besides the implant/plates themselves, with dramatic consequences in terms of postoperative infection and hardware contamination.

METHODS

A retrospective study was conducted on a prospectively maintained database from January 2016 to February 2021. Inclusion criteria involved all patients who underwent an implant-associated infection of the knee and upper third of the leg coupled with a soft tissue reconstruction (STR) using the traditional gastrocnemius muscle (GM) pedicled flap or the chimeric GM-MSAP (medial sural artery perforator) flap.

RESULTS

Thirty-eight patients were included (group A, GM flap, 22 patients; group B, chimeric GM-MSAP flap, 16 patients). No statistically significant differences were detected in terms of age, comorbidities, defect size, follow-up, and flap complications. A statistically significant difference was seen among the groups in terms of successful flap re-raise (required because of a persistent infection of the implant or in a two-stage procedure setting, including the use of a cemented spacer) in favour of the GM-MSAP group.

CONCLUSION

The chimeric GM-MSAP, being safer to reraise if required, can be a significantly more powerful tool in those cases in which a two-stage procedure is planned or when there is a high probability for secondary intervention need, reducing the need to convert to either free flap coverage or amputation.

Discrimination between biological motion with and without social intention: a pilot study using visual scanning in healthy adults

Human beings have a detailed understanding of others' action and body language allowing them to adapt their behaviour for effective social interaction. A proper selection of human motion deserving a social intention over the many human motion surrounding them may be executed by overt visual-spatial attention. The aim of this study was to characterize eye movements in 32 healthy adults while exploring Social and Non-social human biological motion using an eye tracking method according to two paradigms. The "preferential looking paradigm" revealed that the first fixation is more often on the Non-social Motion than Social Motion but the first fixations duration are longer on Social Motion. Moreover, with the same paradigm, subjects spent a greater looking time percentage on Social Motion than Non-social Motion, no matter whether discrimination between categories was asked for or not. In the "blocks paradigm" the looking time percentage varied by the body parts (chests, pelvis and legs) and its distribution was different between categories. Eye movements revealed a spontaneous, fast and durable bias of overt visual-spatial attention favouring the perception of Social Motion and a different visual scanpath for Social compared to Non-social human biological motion. These findings constitute a basis for the investigation of a 'social intention' bias in perception of human biological motion.

Visual perception in children: human, animal and virtual movement activates different cortical areas

This study was designed to relate visual perception of motion (HUMAN, ANIMAL and VIRTUAL) to cortical activity (qEEG parameters). Thirty-four healthy right-handed children (29 months-94 months, mean age 5 years) viewed a video film showing a still image (a lake) and animated images with human, animal and virtual movement. EEGs were recorded while the children watched the video film. The power values of each frequency band theta 1: 3.5-5.5 Hz, theta 2: 5.5-7.5 Hz, alpha 1: 7.5-10.5 Hz, alpha 2: 10.5-13 Hz, beta 1: 13-18 Hz, beta 2: 18-25 Hz and beta 3: 25-35 Hz were analyzed in a four-way repeated-measures ANOVA (age x hemisphere x electrode x type of activation). Three main results were obtained: (1) younger children (< 5 years) showed higher power spectral values than older children; (2) there was specificity for real human movement in the left hemisphere; and (3) activations in the left- and right-hemispheres were different according to the movement visualized. These results indicate that in healthy children, human, animal and virtual movement activates different cortical areas.

Regulation of cognitive activity and early communication development in young autistic, mentally retarded, and young normal children

Based on the Piagetian framework, this study examined regulation of cognitive activity and developmental communication profiles and their interrelationship in groups of autistic, mentally retarded, and normal children of comparable overall, verbal, and oculo-manual developmental ages (from 6 to 24 months). Regulation of activity was assessed with both an object permanence test and an original behavior grid, and development of communication skills with the Guidetti-Tourrette scales (French adaptation of the Seibert-Hogan scales). The results showed evidence of certain types of dysregulation of cognitive activity and a general delay in communication ability in autistic children compared to the other two groups. Moreover, although the intensity of some of these disorders decreased in relation to the developmental levels of social interaction and joint attention in normal children, they were related to both high and low levels of development of social interaction only in autistic children. These findings raise the hypothesis of a relationship between a disorder of disengaging from an activity and developmental levels of social interaction noted at two transitory periods of early development (12 and 24 months) only in children with autism. Developmental and neuropsychological interpretations of this particular pattern are proposed.

Electroencephalographic activity during perception of motion in childhood

The purpose of the present study was to relate observations of biological motion to cortical activity by evaluation of the association of quantified electroencephalogram (qEEG) parameters with a video film projection. Thirty right-handed healthy children (2-8-year-olds) viewed a video film showing still shots and moving shots with human movement or object movement. The EEG was recorded while children watched the video movie and was then subjected to spectral analysis; the spectral powers for theta, alpha and beta bands were matched with corresponding sequences of video film. The power values of each frequency band were analysed in a four-way repeated-measures ANOVA (Age x Hemisphere x Electrode x Sequence). Three main results were obtained: (i) younger children (2-4-year-olds) had higher power spectral values than older children (5-8-year-olds); (ii) greater EEG desynchronization of the left hemisphere was observed; (iii) observation of biological movement was related to a significant decrease in theta 1 and theta 2 power values of EEG in fronto-temporal and central regions of the left hemisphere compared with visual perception of still shots or nonhuman movement. These results indicated some support for the theory that the sensori-motor cortex and Broca's area are activated during visual observation of human motion.

Plasma fatty acid levels in autistic children

Phospholipid fatty acids are major structural components of neuronal cell membranes, which modulate membrane fluidity and hence function. Evidence from clinical and biochemical sources have indicated changes in the metabolism of fatty acids in several psychiatric disorders. We examined the phospholipid fatty acids in the plasma of a population of autistic subjects compared to mentally retarded controls. Our results showed a marked reduction in the levels of 22: 6n-3 (23%) in the autistic subjects, resulting in significantly lower levels of total (n-3) polyunsaturated fatty acids (PUFA) (20%), without significant reduction in the (n-6) PUFA series, and consequently a significant increase in the (n-6)/(n-3) ratio (25%). These variations are discussed in terms of potential differences in PUFA dietary intake, metabolism, or incorporation into cellular membranes between the two groups of subjects. These results open up interesting perspectives for the investigation of new biological indices in autism. Moreover, this might have new therapeutic implications in terms of child nutrition.

Association study of the NF1 gene and autistic disorder

Neurofibromatosis type 1 (NF1) is increased about 150-fold in autistic patients. The aim of this study was to test for an association between the NF1 locus and autistic disorder. The allele distributions of three markers of the NF1 gene were studied in 85 autistic patients and 90 controls. No differences in allele distributions were observed. However, we found a new allele (allele 5) of the GXAlu marker in four autistic patients. Allele 5 was absent in a larger control population (213 individuals). The patients with allele 5 had a more severe clinical picture, mainly in the fields of motility and tonus. Our preliminary results suggest that the NF1 region is not a major susceptibility locus for autism. However, the GXAlu marker of the NF1 gene appears as a possible candidate for a susceptibility locus in a small subgroup of severely affected autistic patients. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:729-732, 1999.

Observation and execution of movement: similarities demonstrated by quantified electroencephalography

Quantified electroencephalography (qEEG) was used to compare cerebral electrical variations while human subjects (10 males and 10 females) were observing and executing finger movements and while they were resting. Video recording enabled elimination of subjects performing involuntary movements. EEGs were recorded from 14 sites in seven frequency bands: theta 1, theta 2, alpha 1, alpha, beta 1, beta 2 and beta 3. Analyses were performed on logarithmically transformed absolute spectral power values. Both observation and execution of finger movements involved a decrease in spectral power compared with resting. This decrease was significant only for the alpha 1 frequency band (7.5-10.5 Hz) and it involved nine of the 14 electrode locations (F7, F8, F4, T6, T5, C3, C4, P3 and P4). This indicates that the motor cortex and the frontal cortex are specifically activated by both observation and execution of finger movements. These results provide evidence that observation and execution of movement share the same cortical network.

[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.

Perception of motion and qEEG activity in human adults

This study was designed to relate visual perception of motion to cortical activity, by evaluation of the association of quantified electroencephalogram (qEEG) parameters with a video film projection. The EEG was recorded from 14 sites according to the International 10-20 system and a common average reference was used. Forty right-handed volunteers (mean age = 24 years) were examined. The video film consisted of 20 s sequences showing still shots and moving shots with human movements or object movements. The EEG was then subjected to spectral analysis; the spectral powers for the theta, alpha and beta bands were calculated for 14 s epochs and compared with sequences of the video film. All analyses were based on logarithmically transformed absolute spectral power values. The power values of each frequency band were analysed in a 3-way repeated measure ANOVA (Hemisphere x Electrode x Sequence). The results were represented by EEG cartography. Significant decreases in the alpha 1, beta 1 and beta 2 power values of EEG in centro-parietal regions of both hemispheres were shown during perception of human motion sequences. This suggests participation of the sensorimotor cortex during visual observation of human motion.

Sry and the testis: molecular pathways of organogenesis

The gene Sry acts as a switch, initiating pathways leading to the differentiation of a testis rather than an ovary from the indifferent gonad (genital ridge) in mammals. The early events following Sry expression include rapid changes in the topographical organization of cells in the XY gonad. Sry must therefore initiate signaling pathways that direct male-specific patterns of proliferation, migration, cell-cell organization, and vascularization. We have identified an increase in male-specific proliferation by 12.0 days post coitum, while proliferation in the female gonad declines. We have also observed male-specific cell migration from the mesonephros into the gonad in a composite organ culture system in which gonads from wild-type mice (CD1) and mesonephroi from a transgenic strain expressing beta-galactosidase in all its cells (ROSA26) were grafted together in vitro at the indifferent stage of gonadogenesis. Migration depends on an active signal that requires the presence of a Y chromosome in the gonadal portion of the graft. The signals that trigger migration operate over considerable distances, suggesting either a long-range diffusible factor or the involvement of a rapid and efficient relay mechanism. Identification of the somatic cells contributed from the mesonephros with cell-specific markers indicated that some of the migrating cells were endothelial, revealing differences in processes of vascularization between male and female gonads. A second distinct population of migrating cells lay in close apposition to endothelial cells, and a third population occupied positions circumscribing areas of condensing Sertoli cells.

[Latent imitation of human movements presented on a videoscopic screen, disclosed by electroencephalographic mapping in the spectator]

Trend to imitate human movement is studied here by EEG mapping. The effects of three kinds of situations are compared: a movement on a TV screen is presented to the subject; a movement is realized by the experimenter in front of the subject; the subject is asked to perform a movement. These three situations elicited important modifications in alpha 1 rhythms over the centroparietal area of the scalp. These results are discussed according to neurophysiological and neuropsychological data, including the possible role of frontal lobe in imitation. Preliminary experiments in psychopathology concern imitation disturbances in autistic children.

Immunoreactivity of sera to a peptide derived from the serotonin 5-HT1A receptor in a group of children with developmental disorders: possible role in non-autistic epilepsy

The presence of autoantibodies against the serotoninergic 5-HT1A receptor has been reported in serum from an autistic child using radioligand binding studies. It is now well established that, in cardiovascular diseases with an autoimmune component, patients present in their sera autoantibodies directed against the second extracellular loop of some G-protein coupled membrane receptors. We thus investigated by an enzyme-immunoassay method the presence of anti-5-HT1A receptor antibodies in sera of children with developmental disorders using synthetic peptides corresponding to the first and the second extracellular loops of this receptor. The population of children with developmental disorders was divided in autistic children with or without EEG abnormalities, and in non-autistic children with or without EEG abnormalities. We found that 6 out of 10 sera of non-autistic children with an abnormal EEG recognized the second extracellular loop of the 5-HT1A receptor. This is significantly higher than the other groups of children with developmental disorders or a healthy control group. These observations support the existence of an autoimmune component in epilepsy.

Male-specific cell migration into the developing gonad

BACKGROUND

The gene Sry acts as a developmental switch, initiating a pathway of gene activity that leads to the differentiation of testis rather than ovary from the indifferent gonad (genital ridge) in mammalian embryos. The early events following Sry expression include rapid changes in the topographical organization of cells in the XY gonad. To investigate the contribution of mesonephric cells to this process, gonads from wild-type mice (CD1), and mesonephroi from a transgenic strain ubiquitously expressing beta-galactosidase (ROSA26), were grafted together in vitro. After culture, organs were fixed and stained for beta-galactosidase activity to identify cells contributed from the mesonephros to the male or female gonad.

RESULTS

Migration of mesonephric cells occurred into XY but not XX gonads from 11.5-16.5 days post coitum (dpc). Somatic cells contributed from the mesonephros were distinguished by their histological location and by available cell-specific markers. Some of the migrating cells were endothelial; a second population occupied positions circumscribing areas of condensing Sertoli cells; and a third population lay in close apposition to endothelial cells.

CONCLUSIONS

OFFgration from the mesonephros to the gonad is male specific at this stage of development and depends on an active signal that requires the presence of a Y chromosome in the gonad. The signals that trigger migration operate over considerable distances and behave as chemoattractants. We suggest that migration of cells into the bipotential gonad may have a critical role in initiating the divergence of development towards the testis pathway.

Serotonin and autism: biochemical and molecular biology features

Whole blood and urinary levels of serotonin (5-hydroxytryptamine; 5-HT) and the derivative urinary 5-hydroxyindoleacetic acid (5-HIAA) were measured in normal and autistic subjects. An association was tested between autism and a marker coding for the 5-HT2A serotonergic receptor gene. Significant group (high urinary 5-HT and low whole blood 5-HT in autism) and age effects (urinary 5-HT decrease with age) were found. Moreover, whole blood 5-HT levels were correlated with clinical state. No differences in allele and genotype frequencies for the 5-HT2A receptor marker were found in this autistic population compared with age-matched healthy students.

Autism and genetics: clinical approach and association study with two markers of HRAS gene

Twin studies and familial aggregation studies indicate that genetic factors could play a role in infantile autism. In an earlier study, we identified a possible positive association between autism and a c-Harvey-ras (HRAS) oncogene marker at the 3' end of the coding region. In an attempt to confirm this finding, we studied a larger population, well-characterized clinically and genetically. We report a positive association between autism and two HRAS markers, the 3' marker used in the initial study and an additional marker in exon 1.

Disorders of regulation of cognitive activity in autistic children

Infantile autism is a pervasive developmental disorder characterized by disturbances concerning not only the areas of socialization and communication ("aloneness") but also the ability to modify and change behavior ("need for sameness"). In most recent studies, various abnormal and deviant cognitive activities, such as the ability to regulate one's behavior, were considered as accounting for these signs. In this report, we examined the regulation of cognitive activity, from a developmental perspective in comparing autistic with mentally retarded children matched in a pairwise manner by global, verbal, and nonverbal developmental ages. All children were tested with tasks adapted from the Object Permanence Test which corresponds to Piaget's sensorimotor development Stages IV to VI. Results showed that autistic children had a pervasive difficulty in maintenance set, made more perseverative errors when the abstraction degree of task was higher, and were more variable in their behavioral strategies. Discussion is focused on the interests and limits of these tasks for the examination of regulation activity from diagnostic and developmental perspectives. Finally, interpretations about recent neuropsychological and neurophysiological works, and additional interdisciplinary studies are suggested.

Association study with two markers of a human homeogene in infantile autism

Epidemiological data and family studies in autism show that there is a genetic susceptibility factor in the aetiology of this syndrome. We carried out an association study in infantile autism. Two markers of the homeogene EN2 involved in cerebellar development were tested in a population of 100 autistic children and in a population of 100 control children. With the MP4 probe showing a PvuII polymorphism, significant differences in the allele frequencies between the two populations were found (chi 2 = 7.99, df = 1, p < 0.01). With the MP5 probe showing an SstI polymorphism, no difference appeared (chi 2 = 1.17, not significant). Several clinical examinations allowed us to characterise the autistic children. Most of them had high scores for autistic behaviour and language disorders but low scores for neurological syndromes. Two children had a significant family history and six children had confirmed syndromes or diseases of genetic origin. Discriminant analysis between clinical and molecular data did not give significant results. These preliminary results must be supported by further analyses of this gene and by studies of its potential involvement in the pathophysiology of the autistic syndrome.

Catecholaminergic metabolism and autism

The authors determined levels of dopamine (DA) and its derivatives homovanillic acid (HVA), 3-4 dihydroxyphenylacetic acid (DOPAC), 3 methoxytyramine and norepinephrine + epinephrine (NE + E) in the urine, and DA, E and NE in the whole blood of 50 autistic children aged between 1 year 11 months and 16 years. An association was tested for between markers coding for the enzymes and D3 dopaminergic receptor genes implicated in the monoaminergic pathway and autism, using restriction fragment-length polymorphism. There were significant modifications of catecholamine metabolites, but no difference for allele frequencies of the genes coding for tyrosine hydroxylase, dopamine beta hydroxylase and DRD3 in this population compared with a healthy school population matched for chronological age. However, some of the data encourage a more complete study of chromosome 11.

Blind ratings of early symptoms of autism based upon family home movies

Ratings of family home movies of 12 infants (0 to 2 years old) who were later diagnosed as autistic and 12 normal infants were performed by two diagnosis-blind psychiatrists with Infant Behavior Summarized Evaluation scale. The objective was to identify early symptoms of autism and their intensity and frequency before and after 1 year of age. Several pathological types of behavior related to socialization, communication, motility, and attention were noted during the first year of infant life and differentiated autistic and normal groups. These same differentiating behaviors, observed again in the second year, were more intense and associated with other pathological types of behavior, in particular, gaze avoidance, hypoactivity, and absence of emotional expressions. Analysis of the evolution of behavioral pathology in autistic children as a group during the 2 first years of life confirms the persistence of and the increase in some types of abnormality related to socialization, communication, motility, and attention functions. The limitations and values of this study concerning the early identification of autistic symptoms and functional impairments from home movies for diagnosis and establishing individualized treatment program are discussed.

Monoamines (serotonin and catecholamines) and their derivatives in infantile autism: age-related changes and drug effects

Levels of dopamine (DA) and its derivatives homovanillic acid (HVA), 3-4 dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3MT) and norepinephrine+epinephrine (NE + E), and serotonin (5HT) and its derivative 5-hydroxyindolacetic acid (5HIAA) were determined from the urine of 156 autistic children aged two to 12 years 6 months, and compared with those of age-matched mentally retarded non-autistic and normal controls. Very significant group and age effects were found for DA, HVA, 3MT, NE + E and 5HT. High HVA, 3MT, NE + E and 5HT levels were found in autistic and non-autistic children. The DA, HVA, 3MT, NE + E, 5HT and 5HIAA levels decreased significantly with age in the three groups. Significantly decreased levels of DA and HVA were observed in autistic children on haloperidol, compared with non-medicated autistic children. The results are discussed in relation to the hypothesis of a maturation defect of monoaminergic systems in autism.

Unimodal and crossmodal reactivity in autism: presence of auditory evoked responses and effect of the repetition of auditory stimuli

Using auditory evoked responses, this work compares the reactivities to unimodal and crossmodal stimuli and the main neurocognitive functions most often disturbed in autism. With the aim of testing the hypothesis that the deficit in the ability to form crossmodal associations in autism is linked to a cognitive abnormality, auditory evoked responses to simple and to crossmodal (auditivo-visual) stimuli were recorded in 30 autistic children and compared with those of 30 normal and 30 mentally retarded children. Relationships between electrophysiological reactivity and neurocognitive functions showed that the cognitive deficit in the ability to maintain crossmodal associations is preceded by a more elementary perceptive abnormality in autistic children.

[Development in the metabolism of dopamine and its derivatives. Application to gross development disorders]

Dopamine (DA) and its metabolites homovanillic acid (HVA) in total, free and conjugated forms, dihydroxyphenylacetic acid (DOPAC) in total, free and conjugated forms, and 3 methoxytyramine (3 MT) levels were determined in the urine of autistic children from 2 years 8 months to 12 years of age and compared to those in normal children of identical age. Very significant group and age effects were found for DA, HVA and 3 MT. In the discussion, results are related to the hypothesis of a disorder in the maturation of the dopaminergic systems in infantile autism.

Electrophysiological evidence of different abilities to form cross-modal associations in children with autistic behavior

This study evaluates the amplitudes of auditory evoked responses and the variability of evoked responses, using a signal-to-noise ratio (SNR) method applied to individual evoked potential in a cross-modal (sound and light) association paradigm in 17 children with autistic behavior matched for sex and chronological age with normal children. Auditory evoked responses were smaller in children with autistic behavior than in normal children. The modifications of amplitudes and of SNR during cross-modal associations allowed the separation of children with autistic behavior into 3 subgroups who presented different patterns of ability to form cross-modal associations. These 3 subgroups of children presented different clinical profiles demonstrating that the differences observed in the ability to form cross-modal associations can be related to differences in the main psychophysiological functions such as attention, intention, motility, association, contact and communication.

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).

Electrophysiological effects of fenfluramine or combined vitamin B6 and magnesium on children with autistic behaviour

The authors compared the effects of fenfluramine or combined vitamin B6 and magnesium treatment on the evoked potential conditioning of 12 children whose autistic behaviour had improved clinically following treatment. The children who were clinically sensitive to combined vitamin B6 and magnesium developed a conditioning phenomenon and the fenfluramine-sensitive children showed an enhancement of the Cz evoked response amplitude. Results are discussed with reference to behaviour modifications observed during treatment.

Urinary dopamine metabolites as indicators of the responsiveness to fenfluramine treatment in children with autistic behavior

Modifications in serotonin and dopamine metabolism were evaluated in 13 children with autistic behavior and related to their responsiveness to fenfluramine treatment. A double-blind medication-placebo crossover design was used. Each patient received 1.5 mg/kg fenfluramine daily for 3 months followed and preceded by placebo for 1 month. Clinical improvement was observed in 6 children (responders). It included reduction of behavioral symptoms such as motor activity, anxiety, mood disturbances, and distractibility. Modifications of serotonin (5-HT), dopamine (DA), and DA metabolites [homovanillic acid (HVA) and dihydroxyphenylacetic acid (DOPAC)] were assessed at urinary levels. Responders and nonresponders showed a significant decrease of urinary 5-HT levels on fenfluramine. The main differences between the two groups of subjects were found with HVA, the major metabolite of DA. Fenfluramine significantly increased HVA levels in responders whereas no significant modification was found in nonresponders. Moreover the initial level of HVA (lower in responders) significantly differentiated the two groups. These results suggest that the clinical response to fenfluramine could be related to the dopaminergic action of this drug and that urinary DA metabolite levels could be considered as indicators of the responsiveness to fenfluramine treatment in children with autistic behavior.

Auditory evoked responses and their modifications during conditioning paradigm in autistic children

Auditory evoked responses (AERs) were recorded from 16 autistic children (ages 2-10 years) and age-matched normal and retarded controls. In order to test the ability to form auditory-visual cross-modal associations, often impaired in autism, the effects on AERs of coupling sound and light were studied with a paradigm that did not require the cooperation of the subject. Several differences between groups were found concerning the frequency and the amplitudes of present AERs. The pattern characterizing the effects on AERs of coupling sound and light (conditioning phenomenon) was observed for both autistic and normal controls, and not for retarded children. Results suggest that autistic children may have a real but slow learning ability.

[Significance of clinical and biological markers in autistic syndromes in children]

Several biological theories were proposed to explain symptoms of childhood autism in terms of monoamine metabolic dysfunction. Clinical, electrophysiological and biochemical markers which support the dopaminergic hypothesis will be given in this paper. A factorial analysis, performed on the 'behavior summarized evaluation' (BSE, scoring behavioral data), exhibits a first component corresponding to the autistic DSM III criteria, and also shows that the disturbances of attention and perception belonged to this component. So, as well as communication, selective attention, perception and gestures, usually considered as regulated by the dopaminergic system are deeply modified and appeared as primary symptoms in autistic syndromes. Many electrophysiological data recorded in autistic children suggest both faulty modulation of sensory input and deficiency in dealing with sensory cross-modal association which have been related to a dysfunctioning of the dopaminergic system. Elevated homovanillic acid levels, the main dopamine metabolite, have been attributed to a reduced re-uptake of dopamine related to a 'longer occupation' of the receptors which is in agreement with the electrophysiological 'sensory overload'. The relationships found between these markers are discussed. Such an approach would contribute to a better understanding of the underlying mechanism of autism.

[Electrophysiologic aspects of infantile autism]

Since the first description of infantile autism by Kanner, many physiopathological hypotheses have been suggested to explain this syndrome. In order to confirm these hypotheses, a lot of biological technics have been used among which the cerebral electroencephalography plays a leading part. The authors describe the main electroencephalographical technics used in autistic children. For each sort of examination, the physiopathological contribution has been studied. Then, these electrophysiological data have been confronted with neuroanatomical hypotheses (temporal, frontal, mesencephalic functional troubles) or neurobiochemical hypotheses (dysfunctioning of the corresponding dopaminergic systems).

Vitamin B6, magnesium, and combined B6-Mg: therapeutic effects in childhood autism

This article reports the behavioral, biochemical, and electrophysiological effects of four therapeutic crossed-sequential double-blind trials with 60 autistic children: Trial A--vitamin B6 plus magnesium/magnesium; Trial B--vitamin B6 plus magnesium; Trial C--magnesium; and Trial D--vitamin B6. Therapeutic effects were controlled using behavior rating scales, urinary excretion of homovanillic acid (HVA), and evoked potential (EP) recordings. The behavioral improvement observed with the combination vitamin B6-magnesium was associated with significant modifications of both biochemical and electrophysiological parameters: the urinary HVA excretion decreased, and EP amplitude and morphology seemed to be normalized. These changes were not observed when either vitamin B6 or magnesium was administered alone.