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Background-Direct brain biopsy is rarely indicated during acute stroke. This study uses peripheral blood mononuclear cells (PBMCs) to determine whether a systemic gene expression profile could be demonstrated in patients with acute ischemic stroke. Methods and Results-Using oligonucleotide microarrays, we compared the gene expression profile of an index cohort of 20 patients with confirmed ischemic stroke on neuroimaging studies with that of 20 referent subjects. Validation studies used quantitative real-time polymerase chain reaction to measure the levels of 9 upregulated genes in the index cohort, and an independent cohort of 9 patients and 10 referent subjects was prospectively studied to determine the accuracy of the Prediction Analysis for Microarrays list to classify stroke. After correction for multiple comparisons with the Bonferroni technique, 190 genes were significantly different between the stroke and referent groups. Broad classes of genes included white blood cell activation and differentiation (Ϸ60%), genes associated with hypoxia and vascular repair, and genes potentially associated with an altered cerebral microenvironment. Real-time polymerase chain reaction confirmed increased mRNA expression in 9 of 9 upregulated stroke-associated genes in the index cohort. A panel of 22 genes derived from the Prediction Analysis for Microarrays algorithm in the index cohort classified stroke in the validation cohort with a sensitivity of 78% and a specificity of 80%.

We have assessed intubating conditions after administration of Org 9426 (rocuronium) 600 micrograms kg-1 at 60 or 90 s in groups of 20 patients anaesthetized with thiopentone, nitrous oxide in oxygen and small doses of fentanyl, and compared the data with those obtained after suxamethonium 1 mg kg-1 in similar groups of patients. The influence of prior suxamethonium administration on the potency of Org 9426 was studied also by constructing a dose-response curve. Intubating conditions after Org 9426 were found to be clinically acceptable (good or excellent) in 95% of patients at 60 s and in all patients at 90 s and in all patients at both times after suxamethonium. The average time for the onset of block following Org 9426 at this dose was 89 s (which is shorter than with any of the currently available non-depolarizing neuromuscular blocking drugs); the duration of clinical relaxation (25% recovery of twitch height) 30 min. Prior administration of suxamethonium did not appear to influence the potency of Org 9426.

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1. Methylglyoxal synthase was purified over 1500-fold from glycerol-grown Escherichia coli K 12 strain CA 244. The purified enzyme was inactivated by heat or proteolysis, had a molecular weight of approx. 67000, a pH optimum of 7.5 and was specific for dihydroxyacetone phosphate with K(m) 0.47mm. 2. The possibility that a Schiff-base intermediate was involved in the reaction mechanism was investigated but not confirmed. 3. The purified enzyme lost activity, especially at low temperature, but could be stabilized by P(i). Two binding sites for P(i) may be present on the enzyme. Of other compounds tested only the substrate, dihydroxyacetone phosphate, and bovine serum albumin showed any significant stabilizing effect. 4. Phosphoenolpyruvate, 3-phosphoglycerate, PP(i) and P(i) were potent inhibitors of the enzyme. Kinetic experiments showed that PP(i) was apparently a simple competitive inhibitor, but inhibition by the other compounds was more complex. In the presence of P(i) the enzyme behaved co-operatively, with at least three binding sites for dihydroxyacetone phosphate. 5. It is proposed that methylglyoxal synthase and glyceraldehyde 3-phosphate dehydrogenase play important roles in the catabolism of the triose phosphates in E. coli. Channelling of dihydroxyacetone phosphate via methylglyoxal would not be linked to ATP formation and could be involved in the uncoupling of catabolism and anabolism.

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Homoprotocatechuate (HPC; 3,4-dihydroxyphenylacetate) is catabolized to Krebs cycle intermediates via extradiol (meta-) cleavage and the necessary enzymes are chromosomally encoded in a variety of bacteria. Based on an analysis of the cloned pathway genes, the Escherichia coli C hpc gene cluster was thought to be arranged in two gene blocks transcribed from a central, divergent, operator/promoter region, which was negatively regulated by the Hpc repressor. By a variety of techniques including expression of cloned hpc genes in pUC18/19 vectors, unidirectional deletion subcloning, hybridization studies and nucleotide sequencing it has now been shown that the hpc pathway structural genes are transcribed in one direction. These experiments have also indicated that a decarboxylase and an isomerase of the pathway are encoded by a single gene (hpcE) and have established the exact structural gene order as hpcRphpcECBDGH. The position of the putative regulatory gene, hpcR, is upstream of the first structural gene (hpcE) for the Hpc pathway enzymes. The deduced open reading frame for the Hpc repressor specifies a protein of 148 amino acids with a subunit molecular weight of 17 kDa. The region between hpcR and the first gene for the pathway enzymes has a sequence similar to that for catabolite activator protein (CAP) binding. This region is immediately upstream of a promoter for the pathway structural genes, which has been identified by transcript mapping.

Escherichia coli K12 grows on 2-phenylethylamine as sole carbon and energy source by converting it, via phenylacetaldehyde, to phenylacetic acid. Phenylacetaldehyde was formed by the action of an inducible amine oxidase and catalase activity was increased sixfold, presumably to ensure removal of the H202 that was expected to be a product of the amine oxidation. The phenylacetaldehyde was oxidized to phenylacetic acid by an inducible NAD+-dependent dehydrogenase. Mutants defective in phenylacetaldehyde dehydrogenase cannot grow on 2-phenylethylamine as carbon and energy source but can still use it as a nitrogen source.