1. Bell J, Abdul-Rahman O, Buttross S. {{Autism and vaccines: search for cause amidst controversy}}. {J Miss State Med Assoc};2011 (Feb);52(2):35-38.
2. Kaluzna-Czaplinska J, Michalska M, Rynkowski J. {{Homocysteine level in urine of autistic and healthy children}}. {Acta Biochim Pol};2011 (Mar 11)
Homocysteine is an amino acid, which plays several important roles in human physiology and is an important biomarker for possible deficiencies of various vitamins (vitamin B6 and B12, folic acid). In this work GC-MS method was used to determine the levels of homocysteine in the urine of autistic and healthy children. The levels of homocysteine in urine samples from 34 autistic and 21 healthy children were 2.36 +/- 1.24 and 0.76 +/- 0.31 (mmol mol(-1) creatinine), respectively. The higher level of homocysteine in autistic children may indicate deficiencies of folic acid and vitamins B6 and B12 in nutrition of these children. The results of this work were taken into consideration in the nutrition of autistic children treated in the Navicula Centre of Diagnosis and Therapy of Autism in Lodz (Poland).
3. King CR. {{A novel embryological theory of autism causation involving endogenous biochemicals capable of initiating cellular gene transcription: A possible link between twelve autism risk factors and the autism ‘epidemic’}}. {Med Hypotheses};2011 (Mar 7)
Human alpha-fetoprotein is a pregnancy-associated protein with an undetermined physiological role. As human alpha-fetoprotein binds retinoids and inhibits estrogen-dependent cancer cell proliferation, and because retinoic acid (a retinol metabolite) and estradiol (an estrogen) can both initiate cellular gene transcription, it is hypothesized here that alpha-fetoprotein functions during critical gestational periods to prevent retinoic acid and maternal estradiol from inappropriately stimulating gene expression in developing brain regions which are sensitive to these chemicals. Prenatal/maternal factors linked to increased autism risk include valproic acid, thalidomide, alcohol, rubella, cytomegalovirus, depression, schizophrenia, obsessive-compulsive disorder, autoimmune disease, stress, allergic reaction, and hypothyroidism. It will be shown how each of these risk factors may initiate expression of genes which are sensitive to retinoic acid and/or estradiol – whether by direct promotion or by reducing production of alpha-fetoprotein. It is thus hypothesized here that autism is not a genetic disorder, but is rather an epigenetic disruption in brain development caused by gestational exposure to chemicals and/or conditions which either inhibit alpha-fetoprotein production or directly promote retinoic acid-sensitive or estradiol-sensitive gene expression. This causation model leads to potential chemical explanations for autistic brain morphology, the distinct symptomatology of Asperger’s syndrome, and the differences between high-functioning and low-functioning autisms with regard to mental retardation, physical malformation, and sex ratio. It will be discussed how folic acid may cause autism under the retinoic acid/estradiol model, and the history of prenatal folic acid supplementation will be shown to coincide with the history of what is popularly known as the autism epidemic. It is thus hypothesized here that prenatal folic acid supplementation has contributed to the post-1980 increase in US autism diagnoses. In addition to explaining the epidemic within the wider retinoic acid/estradiol model of causation, this theory leads to potential explanations for certain genetic findings in autism, autistic regression, and changing trends in autism symptomatology with regard to mental retardation, wheat allergy, and gastrointestinal problems.
4. Paula CS, Fombonne E, Gadia C, Tuchman R, Rosanoff M. {{Autism in Brazil: perspectives from science and society}}. {Rev Assoc Med Bras};2011 (Jan-Feb);57(1):2-5.
5. Ruta L, Ingudomnukul E, Taylor K, Chakrabarti B, Baron-Cohen S. {{Increased serum androstenedione in adults with autism spectrum conditions}}. {Psychoneuroendocrinology};2011 (Mar 11)
Molecular and behavioural evidence points to an association between sex-steroid hormones and autism spectrum conditions (ASC) and/or autistic traits. Prenatal androgen levels are associated with autistic traits, and several genes involved in steroidogenesis are associated with autism, Asperger Syndrome and/or autistic traits. Furthermore, higher rates of androgen-related conditions (such as Polycystic Ovary Syndrome, hirsutism, acne and hormone-related cancers) are reported in women with autism spectrum conditions. A key question therefore is if serum levels of gonadal and adrenal sex-steroids (particularly testosterone, estradiol, dehydroepiandrosterone sulfate and androstenedione) are elevated in individuals with ASC. This was tested in a total sample of n=166 participants. The final eligible sample for hormone analysis comprised n=128 participants, n=58 of whom had a diagnosis of Asperger Syndrome or high functioning autism (33 males and 25 females) and n=70 of whom were age- and IQ-matched typical controls (39 males and 31 females). ASC diagnosis (without any interaction with sex) strongly predicted androstenedione levels (p<0.01), and serum androstenedione levels were significantly elevated in the ASC group (Mann-Whitney W=2677, p=0.002), a result confirmed by permutation testing in females (permutation-corrected p=0.02). This result is discussed in terms of androstenedione being the immediate precursor of, and being converted into, testosterone, dihydrotestosterone, or estrogens in hormone-sensitive tissues and organs.
6. Schipul SE, Keller TA, Just MA. {{Inter-regional brain communication and its disturbance in autism}}. {Front Syst Neurosci};2011;5:10.
In this review article, we summarize recent progress toward understanding disturbances in functional and anatomical brain connectivity in autism. Autism is a neurodevelopmental disorder affecting language, social interaction, and repetitive behaviors. Recent studies have suggested that limitations of frontal-posterior brain connectivity in autism underlie the varied set of deficits associated with this disorder. Specifically, the underconnectivity theory of autism postulates that individuals with autism have a reduced communication bandwidth between frontal and posterior cortical areas, which constrains the psychological processes that rely on the integrated functioning of frontal and posterior brain networks. This review summarizes the recent findings of reduced frontal-posterior functional connectivity (synchronization) in autism in a wide variety of high-level tasks, focusing on data from functional magnetic resonance imaging studies. It also summarizes the findings of disordered anatomical connectivity in autism, as measured by a variety of techniques, including distribution of white matter volumes and diffusion tensor imaging. We conclude with a discussion of the implications of these findings for autism and future directions for this line of research.
7. Semrud-Clikeman M, Fine J. {{Presence of Cysts on Magnetic Resonance Images (MRIs) in Children With Asperger Disorder and Nonverbal Learning Disabilities}}. {J Child Neurol};2011 (Mar 11)
The main purpose of this study was to report the existence of previously unidentified brain cysts or lesions in children with nonverbal learning disabilities, Asperger syndrome, or controls. The authors compared the incidence of cysts or lesions on magnetic resonance images (MRIs) in 28 children with nonverbal learning disability, 26 children with Asperger syndrome, and 24 typical controls for abnormalities. In this study, the authors found 25% of children previously diagnosed with nonverbal learning disability to have unsuspected brain abnormalities generally including cysts or lesions in the occipital region, compared with approximately 4% in the Asperger syndrome or control group. The cysts/lesions were found mainly in the occipital lobe, an area responsible for visual/spatial reasoning. It is appropriate to speculate that there might be a connection between anomalous brain development and skill differences among these groups.
8. Weinstein M, Ben-Sira L, Levy Y, Zachor DA, Itzhak EB, Artzi M, Tarrasch R, Eksteine PM, Hendler T, Bashat DB. {{Abnormal white matter integrity in young children with autism}}. {Hum Brain Mapp};2011 (Apr);32(4):534-543.
This study investigated white matter integrity in young children with autism using diffusion tensor imaging (DTI). Twenty-two children with autism, mean age 3:2 years, and 32 controls, mean age 3:4 years, participated in the study. Tract-based spatial statistics (TBSS) revealed white matter abnormalities in several distinct clusters within the genu and body of the corpus callosum (CC), left superior longitudinal fasciculus (SLF) and right and left cingulum (Cg). TBSS-VOIs analysis was performed in the clusters where differences in fractional anisotropy (FA) were detected to investigate the relationship between changes in FA and diffusivity indices. In all VOIs, increase in FA was caused by a decrease in radial diffusivity (Dr), while no changes in axial diffusivity (Da) or mean diffusivity (MD) were observed. Tractography analysis was applied to further study the CC, SLF, and Cg. Witelson parcellation scheme was used for the CC. Significant increase in FA was seen in children with autism in the mid-body of the CC as well as in the left Cg. It is suggested that such abnormal white matter integrity in young children with autism may adversely affect connectivity between different brain regions and may be linked to some of the behavioral impairments apparent in autism. Hum Brain Mapp, 2011. (c) 2010 Wiley-Liss, Inc.
9. Yerys BE, Wallace GL, Jankowski KF, Bollich A, Kenworthy L. {{Impaired Consonant Trigrams Test (CTT) performance relates to everyday working memory difficulties in children with Autism Spectrum Disorders}}. {Child Neuropsychol};2011 (Mar 7):1-9.
Individuals with Autism Spectrum Disorders (ASD) often struggle with complex tasks, such as those requiring divided attention (simultaneously completing two independent tasks) that also place high demands on working memory. Prior research shows that divided attention is impaired in adults and children with ASD and is related to ASD and comorbid attention deficit/hyperactivity disorder (ADHD) symptoms, but the impact on everyday functioning is unclear. Because ADHD symptoms are associated with poor divided attention and working memory performance in children with ASD, we also examined ADHD symptoms as moderators of divided attention performance. We examined performance on the Consonant Trigrams Test (CTT) between high-functioning 8- to 13-year-olds with ASD (n = 28) and typically developing controls (n = 18) matched on age and IQ. In the ASD group, we also correlated performance with ADHD symptoms and behavior ratings of everyday working memory. CTT performance in children with ASD was significantly worse than in matched controls. A significant correlation between CTT performance and everyday working memory was observed, but CTT performance was not related to comorbid ADHD symptoms in the ASD group. Divided attention with high working-memory demands is a relative weakness in children with high-functioning ASD; this weakness relates to everyday functioning, and it is independent from ADHD symptoms. That ADHD symptoms are not associated with divided attention performance is inconsistent with one prior investigation, which likely results from using different divided attention tasks in the two studies.
10. Zoccante L, Viviani A, Ferro A, Cerini R, Cerruti S, Rambaldelli G, Bellani M, Dusi N, Perlini C, Boscaini F, Pozzi Mucelli R, Tansella M, Della Bernardina B, Brambilla P. {{Increased left parietal volumes relate to delayed language development in autism: a structural mri study}}. {Funct Neurol};2010 (Oct-Dec);25(4):217-221.
The neural basis of language and motor deficits in autism is still not completely clear. The aim of this study was to explore the involvement of the parietal lobe in language and motor development in autism, in view of the recognized role of this region in language and imitation functions. Twenty-eight autistic children underwent an extensive clinical assessment and an MRI examination. A significant direct correlation between age at first word and left parietal gray matter volumes was found (r=0.50, p=0.007). Conversely, age at reaching milestones of motor development, such as the ability to sit and to walk unaided, was not significantly associated with parietal size, after correcting for chronological age and for gender. To the best of our knowledge, this is the first structural MRI report demonstrating a role of left parietal gray matter volumes in delayed language development in autistic children representative of the ‘real world’ autistic population.
