1. Barbaro J, Dissanayake C. {{Developmental Profiles of Infants and Toddlers with Autism Spectrum Disorders Identified Prospectively in a Community-Based Setting}}. {J Autism Dev Disord};2012 (Feb 7)
This prospective, longitudinal, study charted the developmental profiles of young children with Autism Spectrum Disorders (ASD) identified through routine developmental surveillance. 109 children with Autistic Disorder (AD), ‘broader’ ASD, and developmental and/or language delays (DD/LD) were assessed using the Mullen Scales of Early Learning (MSEL) at 12-months (n = 10 assessments), 18-months (n = 45 assessments), and 24-months (n = 99 assessments). The children with AD performed most poorly, overall, than the ASD and DD/LD groups on the MSEL. Furthermore, the children with AD/ASD displayed an uneven cognitive profile, with poorer performance on verbal (particularly receptive language) relative to nonverbal skills. There was also evidence of developmental slowing in verbal skills from 18- to 24-months for children on the spectrum, especially those with AD. Given that the poor receptive, relative to expressive, language profile emerges very early in life for children with AD/ASD, this cognitive profile may serve as an additional red flag to social attention and communication deficits. Receptive language should therefore be stringently monitored in any developmental surveillance program for autism spectrum disorders in the second year of life.
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2. Caffarelli C, Gonnelli S, Tanzilli L, Hayek J, Vichi V, Franci B, Lucani B, Nuti R. {{The relationship between serum ghrelin and body composition with bone mineral density and QUS parameters in subjects with Rett syndrome}}. {Bone};2012 (Jan 27)
Several studies have reported that females with Rett’s syndrome frequently have marked decreases in bone mineral density (BMD). However, the pathogenesis of impaired bone status in RTT girls remains controversial. This study aimed to investigate whether ghrelin, an orexigenic peptide secreted by the stomach, was associated with body composition parameters, bone mineral density and quantitative ultrasound (QUS) in girls with Rett’s syndrome. In 123 Rett girls (13.6+/-8.2years) and in 55 similar age range controls we evaluated ghrelin serum levels, 25OHD, quantitative ultrasound parameters at phalanxes by Bone Profiler-IGEA (amplitude dependent speed of sound: AD-SoS and bone transmission time: BTT), total body bone mineral density (BMD-WB) by Hologic QDR 4500. Whole body mineral content (BMC-WB), BMC-WB/height, fat mass (FM), fat percentage and lean mass (LM) were determined by using the same DXA device. We found that serum ghrelin levels were significantly higher in the Rett patients with respect to the control group (p<0.05). In Rett girls ghrelin serum levels were inversely correlated with both age (R(2)=0.17, p<0.001) and BMI (R(2)=0.14, p<0.001). Moreover, in Rett subjects the values of BMD-WB, BMC-WB, BMC-WB/height and QUS parameters were significantly lower than in control subjects. Fat mass and lean mass were lower in Rett subjects than in controls, but the difference reached the statistical significance only for lean mass. In Rett girls ghrelin serum levels were not predictors of bone status. Instead, we found that in Rett subjects, lean mass, age and 25OHD were significant independent predictors of BMC-WB/h, whereas both age and height were independent predictors of BMD-WB. Moreover, AD-SoS was predicted by age, fat percentage and height; while BTT was predicted only by height. In conclusion, our findings indicate that ghrelin levels were higher in Rett girls with respect to healthy controls, and negatively associated with both DXA and QUS parameters. However, in our study ghrelin was not found to be an independent predictor of bone mass, so supporting the hypothesis that ghrelin is elevated in Rett subjects in a compensatory manner.
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3. Cannon B, Pan C, Chen L, Hadd AG, Russell R. {{A Dual-Mode Single-Molecule Fluorescence Assay for the Detection of Expanded CGG Repeats in Fragile X Syndrome}}. {Mol Biotechnol};2012 (Feb 7)
Fragile X syndrome is the leading cause of inherited mental impairment and is associated with expansions of CGG repeats within the FMR1 gene. To detect expanded CGG repeats, we developed a dual-mode single-molecule fluorescence assay that allows acquisition of two parallel, independent measures of repeat number based on (1) the number of Cy3-labeled probes bound to the repeat region and (2) the physical length of the electric field-linearized repeat region, obtained from the relative position of a single Cy5 dye near the end of the repeat region. Using target strands derived from cell-line DNA with defined numbers of CGG repeats, we show that this assay can rapidly and simultaneously measure the repeats of a collection of individual sample strands within a single field of view. With a low occurrence of false positives, the assay differentiated normal CGG repeat lengths (CGG( N ), N = 23) and expanded CGG repeat lengths (CGG( N ), N = 118), representing a premutation disease state. Further, mixtures of these DNAs gave results that correlated with their relative populations. This strategy may be useful for identifying heterozygosity or for screening collections of individuals, and it is readily adaptable for screening other repeat disorders.
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4. Carey MJ. {{Comment on « timing of increased autistic disorder cumulative incidence »}}. {Environ Sci Technol};2012 (Feb 7);46(3):1948-1949.
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5. Clayton TA. {{Metabolic differences underlying two distinct rat urinary phenotypes, a putative role for gut microbial metabolism of phenylalanine and a possible connection to autism}}. {FEBS Lett};2012 (Feb 1)
A novel explanation is proposed for the metabolic differences underlying two distinct rat urinary compositional phenotypes i.e. that these may arise from differences in the gut microbially-mediated metabolism of phenylalanine. As part of this hypothesis, it is further suggested that elements of the mammalian gut microbiota may convert phenylalanine to cinnamic acid, either by means of an ammonia lyase-type reaction or by means of a three step route via phenylpyruvate and phenyllactate. The wider significance of such conversions is discussed with similar metabolism of tryptophan and subsequent glycine conjugation potentially explaining the origin of trans-indolylacryloylglycine, a postulated marker for autism.
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6. Davis TE, 3rd, Moree BN, Dempsey T, Hess JA, Jenkins WS, Fodstad JC, Matson JL. {{The effect of communication deficits on anxiety symptoms in infants and toddlers with autism spectrum disorders}}. {Behav Ther};2012 (Mar);43(1):142-152.
Autism spectrum disorders (ASDs) are life-long developmental disorders characterized by impairments in the development of reciprocal social and communication skills, abnormal language development, and a restricted repertoire of behaviors and interests. While it has been known for some time that children with ASD can evince elevated rates of anxiety symptoms, little research has been conducted on whether deficits in communication skills affect the range of anxiety symptoms in infants and toddlers with ASD. This study represents a first attempt to determine whether deficits in communication skills have an effect on the expression of anxiety in infants and toddlers with autistic disorder and pervasive developmental disorder-not otherwise specified. Seven hundred thirty-five infants were evaluated with respect to the nature and extent of anxiety symptoms and developmental functioning. Both receptive and expressive communication skills appeared to play a significant role in the manifestation of anxiety symptoms.
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7. Lee TL, Raygada MJ, Rennert OM. {{Integrative gene network analysis provides novel regulatory relationships, genetic contributions and susceptible targets in autism spectrum disorders}}. {Gene};2012 (Jan 26)
Autism spectrum disorders (ASDs) are a group of diseases exhibiting impairment in social drive, communication/language skills and stereotyped behaviors. Though an increased number of candidate genes and molecular interactions have been identified by various approaches, the pathogenesis remains elusive. Based on clinical observations, data from accessible GWAS and expression datasets we identified ASDs gene candidates. Integrative gene network and a novel CNV-centric Node Network (CNN) analysis method highlighted ASDs-associated key elements and biological processes. Functional analysis identified neurological functions including synaptic cholinergic receptor (CHRNA) families, dopamine receptor (DRD2), and correlations between social behavior and oxytocin related pathways. CNN analysis of genome-wide genetic and expression data identified inheritance-related clusters related to PTEN/TSC1/FMR1 and mTor/PI3K regulation. Integrative analysis identified potential regulators of networks, specifically TNF and beta-estradiol, suggesting a potential central role in ASDs. Our data provide information on potential disease mechanisms, and key regulators that may generate novel postulations, and diagnostic molecular biomarkers.
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8. McDonald ME, Paul JF. {{Response to comment on « timing of increased autistic disorder cumulative incidence »}}. {Environ Sci Technol};2012 (Feb 7);46(3):1950-1951.
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9. Peterson CC, Wellman HM, Slaughter V. {{The Mind Behind the Message: Advancing Theory-of-Mind Scales for Typically Developing Children, and Those With Deafness, Autism, or Asperger Syndrome}}. {Child Dev};2012 (Feb 3)
Children aged 3-12 years (n = 184) with typical development, deafness, autism, or Asperger syndrome took a series of theory-of-mind (ToM) tasks to confirm and extend previous developmental scaling evidence. A new sarcasm task, in the format of H. M. Wellman and D. Liu’s (2004) 5-step ToM Scale, added a statistically reliable 6th step to the scale for all diagnostic groups. A key previous finding, divergence in task sequencing for children with autism, was confirmed. Comparisons among diagnostic groups, controlling age, and language ability, showed that typical developers mastered the 6 ToM steps ahead of each of the 3 disabled groups, with implications for ToM theories. The final (sarcasm) task challenged even nondisabled 9-year-olds, demonstrating the new scale’s sensitivity to post-preschool ToM growth.
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10. Sokhadze EM, Baruth JM, Sears L, Sokhadze GE, El-Baz AS, Casanova MF. {{Prefrontal Neuromodulation Using rTMS Improves Error Monitoring and Correction Function in Autism}}. {Appl Psychophysiol Biofeedback};2012 (Feb 7)
One important executive function known to be compromised in autism spectrum disorder (ASD) is related to response error monitoring and post-error response correction. Several reports indicate that children with ASD show reduced error processing and deficient behavioral correction after an error is committed. Error sensitivity can be readily examined by measuring event-related potentials (ERP) associated with responses to errors, the fronto-central error-related negativity (ERN), and the error-related positivity (Pe). The goal of our study was to investigate whether reaction time (RT), error rate, post-error RT change, ERN, and Pe will show positive changes following 12-week long slow frequency repetitive TMS (rTMS) over dorsolateral prefrontal cortex (DLPFC) in high functioning children with ASD. We hypothesized that 12 sessions of 1 Hz rTMS bilaterally applied over the DLPFC will result in improvements reflected in both behavioral and ERP measures. Participants were randomly assigned to either active rTMS treatment or wait-list (WTL) groups. Baseline and post-TMS/or WTL EEG was collected using 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. ERN in TMS treatment group became significantly more negative. The number of omission errors decreased post-TMS. The RT did not change, but post-error RT became slower. There were no changes in RT, error rate, post-error RT slowing, nor in ERN/Pe measures in the wait-list group. Our results show significant post-TMS differences in the response-locked ERP such as ERN, as well as behavioral response monitoring measures indicative of improved error monitoring and correction function. The ERN and Pe, along with behavioral performance measures, can be used as functional outcome measures to assess the effectiveness of neuromodulation (e.g., rTMS) in children with autism and thus may have important practical implications.
