Pubmed du 05/07/13

Pubmed du jour

2013-07-05 12:03:50

1. {{Reassurance from Sweden about autism and IVF}}. {BMJ};2013;347:f4239.

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2. Bjorklund G. {{The role of zinc and copper in autism spectrum disorders}}. {Acta Neurobiol Exp (Wars)};2013;73(2):225-236.

Autism spectrum disorders (ASDs) are a group of developmental disabilities that can cause significant social, communication and behavioral challenges. Several studies have suggested a disturbance in the copper (Cu) and zinc (Zn) metabolism in ASDs. Zinc deficiency, excess Cu levels, and low Zn/Cu ratio are common in children diagnosed with an ASD. The literature also suggests that mercury accumulation may occur as a cause or consequence of metallothionein (MT) dysfunction in children diagnosed with an ASD, which may be one of the causes of Zn deficiency. MTs are proteins with important functions in metal metabolism and protection. Zinc and Cu bind to and participate in the control of the synthesis of MT proteins. Studies indicate that the GABAergic system may be involved in ASDs, and that Zn and Cu may play a role in this system.

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3. Dziembowska M, Pretto DI, Janusz A, Kaczmarek L, Leigh MJ, Gabriel N, Durbin-Johnson B, Hagerman RJ, Tassone F. {{High MMP-9 activity levels in fragile X syndrome are lowered by minocycline}}. {Am J Med Genet A};2013 (Jul 3)

Fragile X syndrome (FXS) is a neurodevelopmental disorder characterized by lack of the FMR1 protein, FMRP, a translational repressor. Its absence leads to up-regulation of locally translated proteins involved in synaptic transmission and plasticity, including the matrix metalloproteinase-9 (MMP-9). In the Fmr1 knock-out (KO), a mouse model of FXS, an abnormal elevated expression of MMP-9 in the brain was pharmacologically down-regulated after treatment with the tetracycline derivative minocycline. Moreover, the rescue of immature dendritic spine morphology and a significant improvement of abnormal behavior were associated with down-regulation of MMP-9. Here, we report on high plasma activity of MMP-9 in individuals with FXS. In addition, we investigate MMP-9 changes in patients with FXS who have gone through a minocycline controlled clinical trial and correlate MMP-9 activity to clinical observations. The results of this study suggest that, in humans, activity levels of MMP-9 are lowered by minocycline and that, in some cases, changes in MMP-9 activity are positively associated with improvement based on clinical measures. (c) 2013 Wiley Periodicals, Inc.

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4. Feinstein NW. {{Making sense of autism: Progressive engagement with science among parents of young, recently diagnosed autistic children}}. {Public Underst Sci};2012 (Sep 5)

This exploratory study examines the significance of science to parents whose children were recently diagnosed with an autism spectrum disorder. It asks: (1) In what manner did science emerge in parents’ concerns and resources as they attempted to understand and advocate for their children? (2) Did some parents engage with science in a qualitatively deeper or more intense manner? Using longitudinal data from interviews and a novel data collection strategy called engagement mapping, it shows that parents asked questions and used resources that were strongly associated with science, but these were vastly outnumbered by « near-science » concerns and resources that mingled meanings from science and daily life. Several parents in the study wove together concerns and resources in an iterative pattern referred to here as progressive engagement with science.

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5. Ghanizadeh A, Derakhshan N. {{N-acetylcysteine for treatment of autism, a case report}}. {J Res Med Sci};2012 (Oct);17(10):985-987.

There are a limited number of Food and Drug Administration (FDA)-approved medications for the treatment of autism. Meanwhile, oxidative stress and neuroinflammation are supposed to play a causative role in autism. N-acetylcysteine may provide cystine, a precursor for glutathione (GSH), which is an important antioxidant factor in the brain. We here report a child with autism, whose symptoms were markedly decreased after taking oral N-acetylcysteine 800 mg/day, in three divided doses. His social interaction was significantly increased. The score of social impairment on a visual analog scale decreased from 10 to 6 in the two-month trial. The aggressive behaviors decreased from 10 to 3. This case suggests that N-acetylcysteine may decrease some symptoms of autism.

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6. Jackson BL, Blackwood EM, Blum J, Carruthers SP, Nemorin S, Pryor BA, Sceneay SD, Bevan S, Crewther DP. {{Magno- and Parvocellular Contrast Responses in Varying Degrees of Autistic Trait}}. {PLoS One};2013;8(6):e66797.

Autistic tendency has been associated with altered visual perception, especially impaired visual motion sensitivity and global/local integration, as well as enhanced visual search and local shape recognition. However, the neurophysiological mechanisms underlying these abnormalities remain poorly defined. The current study recruited 29 young adults displaying low, middle or high autistic trait as measured by Baron-Cohen’s Autism spectrum Quotient (AQ), and measured motion coherence thresholds psychophysically, with manipulation of dot lifetime and stimulus contrast, as well as nonlinear cortical visual evoked potentials (VEPs) over a range of temporal luminance contrast levels from 10% to 95%. Contrast response functions extracted from the major first order and second order Wiener kernel peaks of the VEPs showed consistent variation with AQ group, and Naka-Rushton fits enabled contrast gain and semi-saturation contrasts to be elicited for each peak. A short latency second order response (previously associated with magnocellular processing) with high contrast gain and a saturating contrast response function showed higher amplitude for the High AQ (compared with Mid and Low groups) indicating poorer neural recovery after rapid stimulation. A non-linearity evoked at longer interaction times (previously associated with parvocellular processing) with no evidence of contrast saturation and lower contrast gain showed no difference between autism quotient groups across the full range of stimulus contrasts. In addition, the short latency first order response and a small, early second order second slice response showed gain and semi-saturation parameters indicative of magnocellular origin, while the longer latency first order response probably reflects a mixture of inputs (including feedback from higher cortical areas). Significant motion coherence (AQ group) * (dot lifetime) interactions with higher coherence threshold for limited dot lifetime stimuli is consistent with atypical magnocellular functioning, however psychophysical performance for those with High AQ is not explained fully, suggesting that other factors may be involved.

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7. Lau NM, Green PH, Taylor AK, Hellberg D, Ajamian M, Tan CZ, Kosofsky BE, Higgins JJ, Rajadhyaksha AM, Alaedini A. {{Markers of Celiac Disease and Gluten Sensitivity in Children with Autism}}. {PLoS One};2013;8(6):e66155.

OBJECTIVE: Gastrointestinal symptoms are a common feature in children with autism, drawing attention to a potential association with celiac disease or gluten sensitivity. However, studies to date regarding the immune response to gluten in autism and its association with celiac disease have been inconsistent. The aim of this study was to assess immune reactivity to gluten in pediatric patients diagnosed with autism according to strict criteria and to evaluate the potential link between autism and celiac disease. METHODS: Study participants included children (with or without gastrointestinal symptoms) diagnosed with autism according to both the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview, Revised (ADI-R) (n = 37), their unaffected siblings (n = 27), and age-matched healthy controls (n = 76). Serum specimens were tested for antibodies to native gliadin, deamidated gliadin, and transglutaminase 2 (TG2). Affected children were genotyped for celiac disease associated HLA-DQ2 and -DQ8 alleles. RESULTS: Children with autism had significantly higher levels of IgG antibody to gliadin compared with unrelated healthy controls (p<0.01). The IgG levels were also higher compared to the unaffected siblings, but did not reach statistical significance. The IgG anti-gliadin antibody response was significantly greater in the autistic children with gastrointestinal symptoms in comparison to those without them (p<0.01). There was no difference in IgA response to gliadin across groups. The levels of celiac disease-specific serologic markers, i.e., antibodies to deamidated gliadin and TG2, did not differ between patients and controls. An association between increased anti-gliadin antibody and presence of HLA-DQ2 and/or -DQ8 was not observed. CONCLUSIONS: A subset of children with autism displays increased immune reactivity to gluten, the mechanism of which appears to be distinct from that in celiac disease. The increased anti-gliadin antibody response and its association with GI symptoms points to a potential mechanism involving immunologic and/or intestinal permeability abnormalities in affected children.

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8. Lotan M, Reves-Siesel R, Eliav-Shalev RS, Merrick J. {{Osteoporosis in Rett syndrome: a case study presenting a novel management intervention for severe osteoporosis}}. {Osteoporos Int};2013 (Jul 5)

The present article describes a successful novel therapeutic intervention with Aredia with one child with Rett syndrome, after suffering from six pathological fractures within less than 3 years due to severe osteoporosis. Since the initiation of the treatment (3 years ago), the child has not suffered any fractures. Patients with chronic diseases and those with disabilities or on anticonvulsant medications are at risk for low bone density and possibly for the resultant pathologic fractures that define osteoporosis in children. Individuals with Rett syndrome (RS) have been shown to have low bone mineral density (or osteopenia) at a young age. If osteoporosis occurs in a girl with RS, it can inflict pain and seriously impair the child’s mobility and quality of life. The present article describes a case study of a child with RS (showing an average of 1.75 fractures annually for the 4 years preceding the treatment) before and after a treatment with Aredia. Patient received 30 mg/day for 3 days on a once every 3-month cycle. There was a 45 % improvement in bone mass density (BMD) values from pre-post-intervention. The child had no fractures in the 3 years posttreatment. This finding is significant (p < 0.03). The BMD Z-scores of the child showed severe osteoporosis (Z-score of -3.8) at pre-intervention and are elevated to osteopenia levels (Z-score of -1.3) at post-intervention measurements. All measurements suggest that the treatment successfully reversed the osteoporotic process and prevented further fractures. This change caused great relief to the child and her family and an improvement in their quality of life. The findings support the ability (in one case) to reverse the progression of osteoporosis in individuals with Rett syndrome showing severe osteoporosis with multiple fractures.

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9. Lukose R, Brown K, Barber CM, Kulesza RJ, Jr. {{Quantification of the Stapedial Reflex Reveals Delayed Responses in Autism}}. {Autism Res};2013 (Jul 3)

Autism is a developmental disorder characterized, in part, by sensory abnormalities. It is well established that most if not all patients with autism have problems with auditory processing, ranging from deafness to hyperacusis, and physiological testing of auditory function (i.e. auditory brain stem responses) implicates brain stem dysfunction in autism. Additionally, previous research from this lab has revealed significantly fewer auditory brain stem neurons in autistic subjects as young as 2 years of age. These observations have led us to hypothesize that objective, noninvasive measures of auditory function can be used as an early screening tool to identify neonates with an elevated risk of carrying a diagnosis of autism. Here, we provide a detailed quantitative investigation of the acoustic stapedial reflex (ASR), a three- or four-neuron brain stem circuit, in young autistic subjects and normal developing controls. Indeed, we find significantly lower thresholds, responses occurring at significantly longer latency and right-left asymmetry in autistic subjects. The results from this investigation support deficits in auditory function as a cardinal feature of autism and suggest that individuals with autism can be identified by their ASR responses. Autism Res 2013, : -. (c) 2013 International Society for Autism Research, Wiley Periodicals, Inc.

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10. Menashe I, Larsen EC, Banerjee-Basu S. {{Prioritization of Copy Number Variation Loci Associated with Autism from AutDB-An Integrative Multi-Study Genetic Database}}. {PLoS One};2013;8(6):e66707.

Copy number variants (CNVs) are thought to play an important role in the predisposition to autism spectrum disorder (ASD). However, their relatively low frequency and widespread genomic distribution complicates their accurate characterization and utilization for clinical genetics purposes. Here we present a comprehensive analysis of multi-study, genome-wide CNV data from AutDB (http://mindspec.org/autdb.html), a genetic database that accommodates detailed annotations of published scientific reports of CNVs identified in ASD individuals. Overall, we evaluated 4,926 CNVs in 2,373 ASD subjects from 48 scientific reports, encompassing approximately 2.12×109 bp of genomic data. Remarkable variation was seen in CNV size, with duplications being significantly larger than deletions, (P = 3×10-105; Wilcoxon rank sum test). Examination of the CNV burden across the genome revealed 11 loci with a significant excess of CNVs among ASD subjects (P<7×10-7). Altogether, these loci covered 15,610 kb of the genome and contained 166 genes. Remarkable variation was seen both in locus size (20 – 4950 kb), and gene content, with seven multigenic (>/=3 genes) and four monogenic loci. CNV data from control populations was used to further refine the boundaries of these ASD susceptibility loci. Interestingly, our analysis indicates that 15q11.2-13.3, a genomic region prone to chromosomal rearrangements of various sizes, contains three distinct ASD susceptibility CNV loci that vary in their genomic boundaries, CNV types, inheritance patterns, and overlap with CNVs from control populations. In summary, our analysis of AutDB CNV data provides valuable insights into the genomic characteristics of ASD susceptibility CNV loci and could therefore be utilized in various clinical settings and facilitate future genetic research of this disorder.

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11. Mueller S, Keeser D, Samson AC, Kirsch V, Blautzik J, Grothe M, Erat O, Hegenloh M, Coates U, Reiser MF, Hennig-Fast K, Meindl T. {{Convergent Findings of Altered Functional and Structural Brain Connectivity in Individuals with High Functioning Autism: A Multimodal MRI Study}}. {PLoS One};2013;8(6):e67329.

Brain tissue changes in autism spectrum disorders seem to be rather subtle and widespread than anatomically distinct. Therefore a multimodal, whole brain imaging technique appears to be an appropriate approach to investigate whether alterations in white and gray matter integrity relate to consistent changes in functional resting state connectivity in individuals with high functioning autism (HFA). We applied diffusion tensor imaging (DTI), voxel-based morphometry (VBM) and resting state functional connectivity magnetic resonance imaging (fcMRI) to assess differences in brain structure and function between 12 individuals with HFA (mean age 35.5, SD 11.4, 9 male) and 12 healthy controls (mean age 33.3, SD 9.0, 8 male). Psychological measures of empathy and emotionality were obtained and correlated with the most significant DTI, VBM and fcMRI findings. We found three regions of convergent structural and functional differences between HFA participants and controls. The right temporo-parietal junction area and the left frontal lobe showed decreased fractional anisotropy (FA) values along with decreased functional connectivity and a trend towards decreased gray matter volume. The bilateral superior temporal gyrus displayed significantly decreased functional connectivity that was accompanied by the strongest trend of gray matter volume decrease in the temporal lobe of HFA individuals. FA decrease in the right temporo-parietal region was correlated with psychological measurements of decreased emotionality. In conclusion, our results indicate common sites of structural and functional alterations in higher order association cortex areas and may therefore provide multimodal imaging support to the long-standing hypothesis of autism as a disorder of impaired higher-order multisensory integration.

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12. Russo AJ. {{Correlation Between Hepatocyte Growth Factor (HGF) and Gamma-Aminobutyric Acid (GABA) Plasma Levels in Autistic Children}}. {Biomark Insights};2013;8:69-75.

There is much support for the role of Gamma-Aminobutyric acid (GABA) in the etiology of autism. Recent research has shown that hepatocyte growth factor (HGF) modulates GABAergic inhibition and seizure susceptibility. This study was designed to determine and correlate plasma levels of HGF, GABA, as well as symptom severity, in autistic children and neurotypical controls. Plasma from 48 autistic children and 29 neurotypical controls was assessed for HGF and GABA concentration using ELISAs. Symptom severity was assessed in these autistic individuals and compared to HGF and GABA concentrations. We previously reported that autistic children had significantly decreased levels of HGF. In this study, the same autistic children had significantly increased plasma levels of GABA (P = 0.002) and decreased HGF levels correlated with these increased GABA levels (r = 0.3; P = 0.05). High GABA levels correlated with increasing hyperactivity (r = 0.6; P = 0.0007) and impulsivity severity (r = 0.5; P = 0.007), tip toeing severity (r = 0.35; P = 0.03), light sensitivity (r = 0.4; P = 0.02), and tactile sensitivity (r = 0.4; P = 0.01). HGF levels did not correlate significantly with any symptom severity. These results suggest an association between HGF and GABA levels and suggest that plasma GABA levels are related to symptom severity in autistic children.

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13. Shimada S, Okamoto N, Nomura S, Fukui M, Shimakawa S, Sangu N, Shimojima K, Osawa M, Yamamoto T. {{Microdeletions of 5.5 Mb (4q13.2-q13.3) and 4.1 Mb (7p15.3-p21.1) associated with a saethre-chotzen-like phenotype, severe intellectual disability, and autism}}. {Am J Med Genet A};2013 (Jul 4)

We observed a patient with a Saethre-Chotzen-like phenotype with severe neurological features. Saethre-Chotzen syndrome (acrocephalosyndactyly type III; SCS; OMIM #101400) is an autosomal dominant craniosynostosis syndrome characterized by craniofacial and mild limb abnormalities. The phenotypic features of chromosomal microdeletions involving the 7p21.1, where the twist homolog 1 gene (TWIST1) responsible for SCS is located, are recognized as a contiguous gene deletion syndrome with SCS and other phenotypic manifestations. In this study, we identified microdeletions in 4q13.2 and 7p21.1 in a patient with SCS and severe neurological features including developmental delay and autistic behavior. In comparison to other SCS patients with intragenic mutations or small deletions in 7p21.1, neurological features seen in this patient were extremely severe, likely modified by a concurrent deletion of 4q13.2. Both microdeletions were de novo and paternal in origin. Further information on such concurrent chromosomal deletions should be accumulated for better understanding of the mechanism. (c) 2013 Wiley Periodicals, Inc.

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14. van Rijn S, Stockmann L, Borghgraef M, Bruining H, van Ravenswaaij-Arts C, Govaerts L, Hansson K, Swaab H. {{The Social Behavioral Phenotype in Boys and Girls with an Extra X Chromosome (Klinefelter Syndrome and Trisomy X): A Comparison with Autism Spectrum Disorder}}. {J Autism Dev Disord};2013 (Jul 4)

The present study aimed to gain more insight in the social behavioral phenotype, and related autistic symptomatology, of children with an extra X chromosome in comparison to children with ASD. Participants included 60 children with an extra X chromosome (34 boys with Klinefelter syndrome and 26 girls with Trisomy X), 58 children with ASD and 106 controls, aged 9 to 18 years. We used the Autism Diagnostic Interview, Social Responsiveness Scale, Social Anxiety Scale and Social Skills Rating System. In the extra X group, levels of social dysfunction and autism symptoms were increased, being in between controls and ASD. In contrast to the ASD group, the extra X group showed increased social anxiety. The effects were similar for boys and girls with an extra X chromosome.

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15. Wang CC, Lin HC, Chan YH, Gean PW, Yang YK, Chen PS. {{5-HT1A-receptor agonist modified amygdala activity and amygdala-associated social behavior in a valproate-induced rat autism model}}. {Int J Neuropsychopharmacol};2013 (Jul 3):1-13.

Accumulating evidence suggests that dysfunction of the amygdala is related to abnormal fear processing, anxiety, and social behaviors noted in autistic spectrum disorders (ASDs). In addition, studies have shown that disrupted brain serotonin homeostasis is linked to ASD. With a valproate (VPA)-induced rat ASD model, we investigated the possible role of amygdala serotonin homeostasis in autistic phenotypes and further explored the underlying mechanism. We first discovered that the distribution of tryptophan hydroxylase immunoreactivity in the caudal raphe system was modulated on postnatal day (PD) 28 of the VPA-exposed offspring. Then, we found a significantly higher serotonin transporter availability in the amygdala of the VPA-exposed offspring on PD 56 by using single photon emission computed tomography and computed tomography co-registration following injection of 123I-labeled 2-((2-(dimethylamino)methyl)phenyl)thio)-5-iodophenylamine(123I[ADAM]). Furthermore, treatment with 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A receptor agonist, increased social interaction and improved fear memory extinction in the VPA-exposed offspring. 8-OH-DPAT treatment also reversed the characteristics of miniature excitatory post-synaptic currents as well as paired pulse facilitation observed in lateral amygdala slices. These results provided further evidence to support the role of the amygdala in characteristic behavioral changes in the rat ASD model. The serotonergic projections that modulate the amygdala function might play a certain role in the development and treatment of behavioral symptoms exhibited in individuals with ASD.

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16. Wu MS, McGuire JF, Arnold EB, Lewin AB, Murphy TK, Storch EA. {{Psychometric Properties of the Children’s Yale-Brown Obsessive Compulsive Scale in Youth with Autism Spectrum Disorders and Obsessive-Compulsive Symptoms}}. {Child Psychiatry Hum Dev};2013 (Jul 5)

The psychometric properties of the Children’s Yale-Brown Obsessive Compulsive Scale (CY-BOCS) were investigated in 46 treatment-seeking youth, 7-15 years of age, who were diagnosed with an autism spectrum disorder (ASD) and exhibited obsessive-compulsive symptoms. The CY-BOCS Total score exhibited good internal consistency, with differing internal consistencies observed on the Obsession Severity scale (alpha = 0.86) and Compulsion Severity scale (alpha = 0.59). Good to excellent inter-rater reliability was observed for the CY-BOCS Total score and both Severity scales. Convergent and divergent validity of the CY-BOCS Total score and both Severity scales were satisfactory. Insight into obsessive-compulsive symptoms was moderately associated with the CY-BOCS Total score. The CY-BOCS demonstrated treatment sensitivity, demonstrating significant changes in obsessive-compulsive symptoms within a subsample of youth receiving cognitive-behavioral treatment. Overall, the CY-BOCS demonstrated adequate psychometric properties and utility in assessing obsessive-compulsive symptoms in youth with ASD and clinically significant obsessive-compulsive symptoms.

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