Quantitative magnetic resonance image analysis of the cerebellum in macrocephalic and normocephalic children and adults with autism. J Int Neuropsychol Soc
ABSTRACT A detailed morphometric analysis of the cerebellum in autism with and without macrocephaly. Four subject groups (N = 65; male; IQs > or = 65; age 7 to 26 years) were studied with quantitative MRI; normocephalic and macrocephalic individuals with autism without mental retardation were compared to normocephalic and benign macrocephalic typically developing individuals. Total cerebellum volumes and surface areas of four lobular midsagittal groups were measured. Independent t-tests between autism and control subjects matched for head size revealed no significant differences. Multivariate analyses of variance were also performed, using the diagnostic group as the fixed factor, cerebellar measures as the dependent variables and total intracranial volume, total brain volume, age, verbal IQ, and performance IQ as covariates. No significant differences were found; however, a trend was noted in which macrocephalic individuals with autism consistently exhibited slightly smaller cerebellar volume or surface area when compared to individuals with benign macrocephaly. In autism, with and without macrocephaly, cerebellar structures were found to be proportional to head size and did not differ from typically developing subjects.
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ABSTRACT: Autism Spectrum Disorder (ASD) is a group of behaviourally defi ned neurodevelopmental disorders of childhood onset characterised by impairments in communication and social reciprocity as well as a range of distinctive non-social symptoms. Despite including some of the most heritable disorders in psychiatry, it has proved difficult to identify risk genes for ASD, and to build models for the neurobiological mechanisms through which putative risk factors might operate to give rise to the ASD behavioural phenotype. In this chapter we detail why measures of brain anatomy derived from structural magnetic resonance images have been put forward as potential alternative endophenotypes that might increase our ability to identify risk genes and associated brain mechanisms for ASD. We then examine the progress that has been made so far in identifying neurostructural endophenotypes for ASD, and consider some of the challenges and opportunities presented by this new line of research in ASD neurobiology.
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ABSTRACT: We describe the isolation and characterization of a new biosynthetic gene, MET2, from the methylotrophic yeast Pichia pastoris. The predicted product of PpMET2 is significantly similar to its Saccharomyces cerevisiae counterpart, ScMET2, which encodes homoserine-O-transacetylase. The ScMET2 was able to complement the P. pastoris met2 strain; however, the converse was not true. Expression vectors based on PpMET2 for the intracellular and secreted production of foreign proteins and corresponding auxotrophic strains were constructed and tested for use in heterologous expression. The expression vectors and corresponding strains provide greater flexibility when using P. pastoris for recombinant protein expression.FEMS Yeast Research 08/2005; 5(10):935-42. DOI:10.1016/j.femsyr.2005.03.009 · 2.44 Impact Factor