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Schizophrenia is a severe psychiatric disorder with a world-wide prevalence of 1%. The pathophysiology of the illness is not understood, but is thought to have a strong genetic component with some environmental influences on aetiology. To gain further insight into disease mechanism, we used microarray technology to determine the expression of over 30 000 mRNA transcripts in post-mortem tissue from a brain region associated with the pathophysiology of the disease (Brodmann area 10: anterior prefrontal cortex) in 28 schizophrenic and 23 control patients. We then compared our study (Charing Cross Hospital prospective collection) with that of an independent prefrontal cortex dataset from the Harvard Brain Bank. We report the first direct comparison between two independent studies. A total of 51 gene expression changes have been identified that are common between the schizophrenia cohorts, and 49 show the same direction of disease-associated regulation. In particular, changes were observed in gene sets associated with synaptic vesicle recycling, transmitter release and cytoskeletal dynamics. This strongly suggests multiple, small but synergistic changes in gene expression that affect nerve terminal function.

Pichia pastoris is a methylotrophic yeast increasingly important in the production of therapeutic proteins. Expression vectors are based on the methanol-inducible AOX1 promoter and are integrated into the host chromosome. In most cases high copy number integration has been shown to be important for high-level expression. Since this occurs at low frequency during transformation, we previously used DNA dot blot screens to identify suitable clones. In this paper we report the use of vectors containing the Tn903 kanr gene conferring G418-resistance. Initial experiments demonstrated that copy number showed a tight correlation with drug-resistance. Using a G418 growth inhibition screen, we readily isolated a series of transformants, containing progressively increasing numbers (1 to 12) of a vector expressing HIV-1 ENV, which we used to examine the relationship between copy number and foreign mRNA levels. Northern blot analysis indicated that ENV mRNA levels from a single-copy clone were nearly as high as AOX1 mRNA, and increased progressively with increasing copy number so as to greatly exceed AOX1 mRNA. We have also developed protocols for the selection, using G418, of high copy number transformants following spheroplast transformation or electroporation. We anticipate that these protocols will simplify the use of Pichia as a biotechnological tool.

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Figure 2Effect of chronic treatment of rats with albuterol (a-d) or PGE 2 (e and f) on lung function in anesthetized rats. Animals were given albuterol, PGE 2 (open bars; both 40 µg/kg/h) or vehicle (filled bars) for 7 days and then instrumented for the measurement of lung function. ACh (500 µg/kg intravenously) was administered and the maximum increase in overflow pressure was measured. When baseline lung function was reestablished, albuterol (Alb; 100 µg/kg; a and f), PGE 2 (PG; 300 µg/kg; b and e), forskolin (F; 300 µg/kg; c), or IBMX (300 µg/kg; d) was given intravenously, and 5 minutes later, ACh was administered again and any change in overflow pressure was noted. Each bar represents the mean ± SEM of four independent determinations. A P < 0.05, significant protection of ACh-induced bronchoconstriction.