Brain abscess in children - epidemiology, predisposing factors and management in the modern medicine era.

AIMS: Brain abscess is rare in children. Predisposing factors are found in almost 85% of cases. Overall, 25% of brain abscesses develop in children, mostly in the 4-7 years age group. Our study aimed to characterize children with brain abscesses treated in our hospital, identify risk factors, pathogens and short-term outcome. METHODS: A retrospective cohort of 20 years period, (1989-2009) included 27 children (0-18 years). Medical records were analysed for age, gender, presenting symptoms and signs, predisposing factors, laboratory tests, imaging, microbiology results, treatment and outcome. RESULTS: Of all the children, 63% (17/27) were male patients; mean age was 7.9 years and 52% were referred from other hospitals. Predisposing factors were identified in 81%, congenital heart disease and otitis were rare and sinusitis was found in 22% of the children. Main symptoms and signs included headaches, fever, neurological signs convulsions, (41%, 81%, 78% and 41% respectively). In 30% of cases, cultures were sterile. All patients were operated in addition to antibiotic treatment. Outcome was good with low mortality rate (3.7%). CONCLUSIONS: Manifestations of brain abscess may be subtle. A high index of suspicion and early imaging are warranted, different predisposing factors may reflect early intervention for congenital heart diseases. Mortality is rare in the modern medicine era.

4-Coumarate:coenzyme A ligase in hybrid poplar. Properties of native enzymes, cDNA cloning, and analysis of recombinant enzymes.

The enzyme 4-coumarate:coenzyme A ligase (4CL) is important in providing activated thioester substrates for phenylpropanoid natural product biosynthesis. We tested different hybrid poplar (Populus trichocarpa x Populus deltoides) tissues for the presence of 4CL isoforms by fast-protein liquid chromatography and detected a minimum of three 4CL isoforms. These isoforms shared similar hydroxycinnamic acid substrate-utilization profiles and were all inactive against sinapic acid, but instability of the native forms precluded extensive further analysis. 4CL cDNA clones were isolated and grouped into two major classes, the predicted amino acid sequences of which were 86% identical. Genomic Southern blots showed that the cDNA classes represent two poplar 4CL genes, and northern blots provided evidence for their differential expression. Recombinant enzymes corresponding to the two genes were expressed using a baculovirus system. The two recombinant proteins had substrate utilization profiles similar to each other and to the native poplar 4CL isoforms (4-coumaric acid > ferulic acid > caffeic acid; there was no conversion of sinapic acid), except that both had relatively high activity toward cinnamic acid. These results are discussed with respect to the role of 4CL in the partitioning of carbon in phenylpropanoid metabolism.

A meristem-related gene from tomato encodes a dUTPase: analysis of expression in vegetative and floral meristems.

A meristem-specific gene coding for deoxyuridine triphosphatase (EC 3.6.1.23) (dUTPase) in tomato was isolated, and its developmental expression in vegetative and floral apices was monitored. An 18-kD polypeptide, P18, was isolated as a consequence of its accumulation in arrested floral meristems of anantha mutant plants. The corresponding cDNA isolated from an expression library exhibited a 40 to 60% similarity with the pseudoprotease sequences of poxviruses, genes that have been suggested to encode dUTPases. Enzymatic tests and conservation of peptide motifs common to bacterial and viral genes verified that the P18 cDNA clone indeed represents a eukaryotic dUTPase. Immunogold localization and in situ hybridization experiments showed that polypeptides and transcripts of dUTPase are maintained at high levels in apical meristematic cells of vegetative and floral meristems. dUTPase gene activity is also high in the potentially meristematic cells of the provascular and vascular system. Its expression is lower in the immediate parenchymal derivatives of the apical meristematic cells, and this downregulation marks, perhaps, the transition from totipotency to the first differentiated state.