Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, can exhibit significant ecological flexibility that is likely reflective of a dynamic genome. Using whole-genome Bp microarrays, we examined patterns of gene presence and absence across 94 South East Asian strains isolated from a variety of clinical, environmental, or animal sources. 86% of the Bp K96243 reference genome was common to all the strains representing the Bp “core genome”, comprising genes largely involved in essential functions (eg amino acid metabolism, protein translation). In contrast, 14% of the K96243 genome was variably present across the isolates. This Bp accessory genome encompassed multiple genomic islands (GIs), paralogous genes, and insertions/deletions, including three distinct lipopolysaccharide (LPS)-related gene clusters. Strikingly, strains recovered from cases of human melioidosis clustered on a tree based on accessory gene content, and were significantly more likely to harbor certain GIs compared to animal and environmental isolates. Consistent with the inference that the GIs may contribute to pathogenesis, experimental mutation of BPSS2053, a GI gene, reduced microbial adherence to human epithelial cells. Our results suggest that the Bp accessory genome is likely to play an important role in microbial adaptation and virulence.

A lterations in the ABL tyrosine kinase are characteristic genetic events in multiple forms of leukemia. In humans, leukemogenic forms of ABL arise from chromosomal translocations. In the resulting fusion proteins, residues encoded by the first exon of ABL are replaced by sequence from the BCR protein, resulting in 185-kDa and 210-kDa isoforms or, less frequently, from the TEL protein (1). In chronic myelogenous leukemia, p210 BCR͞ABL is found in 95% of all cases (2). These same hybrid proteins can transform cultured cells and induce leukemia in mice. ABL sequences encoding tyrosine kinase activity are essential for transformation (3)(4)(5). Also present are ABL regulatory sequences, including Src homology (SH)3, SH2, and actin-binding domains. The fusion of ABL with BCR leads to increased kinase activity and an apparent shift in subcellular localization (6), changes that alter the magnitude and characteristics of downstream signals.BCR͞ABL-induced transformation depends on its continued expression (7-9). Dominant negative-acting proteins that block BCR͞ABL-mediated transformation of cultured cells have been described (10)(11)(12)(13)(14). These proteins typically rely on disruption of broadly used signaling components required indirectly for BCR͞ ABL function. Ideally, an effective BCR͞ABL inhibitor should directly suppress the activity that most closely correlates with transformation. The ABL kinase-specific inhibitor STI-571, for instance, has shown promise as an effective BCR͞ABL-suppressing drug (15).We propose an alternate approach to inhibition of BCR͞ABL and downstream pathways, using modular peptides to combine tyrosine phosphatase and ABL-binding functions resulting in efficient ABL-targeted tyrosine phosphatases.Protein tyrosine phosphatases (PTPs) (16, 17) might act as BCR͞ABL inhibitors through the dephosphorylation of ABL and͞or its substrates. Overexpression of PTP1B inhibit fibroblast transformation by p210 BCR͞ABL (18), and this effect may be caused, in part, by direct dephosphorylation of BCR͞ABL (19). SHP1 (SHPTP1) also can interact with and partially inhibit the function of c-ABL (20) and BCR͞ABL (21). These phosphatases may be endogenous down-regulators of ABL that can inhibit BCR͞ABL. Their effectiveness as BCR͞ABL suppressers is moderate, however, and may be tempered by deleterious effects from overexpression. The inhibition potency of these phosphatases might be improved markedly if they could be liberated from normal regulation and targeted to BCR͞ABL.RIN1 is both a substrate and binding partner of ABL (22). RIN1 also interacts with BCR͞ABL, and this association is detected in leukemia-derived cell (23). The ABL binding domain (ABD) of RIN1 interacts with both the SH3 and SH2 domains of ABL (ref.23; this work). We have used the RIN1-ABD as an ''escort'' peptide to deliver the SHP1 tyrosine phosphatase catalytic domain to BCR͞ABL. The resulting escort͞inhibitor (ABD͞SHP1c) showed potent suppressive activity against BCR͞ABL in a variety of assays including leukemogenesis. These results sug...

The neuraminidase (NA) inhibitor (NAI) oseltamivir (OST) is the most widely used influenza antiviral drug. Several NA amino acid substitutions are reported to reduce viral susceptibility to OST in in vitro assays. However, whether there is a correlation between the level of reduction in susceptibility in vitro and the efficacy of OST against these viruses in vivo is not well understood. In this study, a ferret model was utilised to evaluate OST efficacy against circulating influenza A and B viruses with a range of in vitro generated 50% inhibitory concentrations (IC 50) values for OST. OST efficacy against an A(H1N1)pdm09 and an A(H1N1) pdm09 virus with the H275Y substitution in neuraminidase was also tested in the macaque model. The results from this study showed that OST had a significant impact on virological parameters compared to placebo treatment of ferrets infected with wild-type influenza A viruses with normal IC 50 values (~1 nM). However, this efficacy was lower against wild-type influenza B and other viruses with higher IC 50 values. Differing pathogenicity of the viruses made evaluation of clinical parameters difficult, although some effect of OST in reducing clinical signs was observed with influenza A(H1N1) and A(H1N1)pdm09 (H275Y) viruses. Viral titres in macaques were too low to draw conclusive results. Analysis of the ferret data revealed a correlation between IC 50 and OST efficacy in reducing viral shedding but highlighted that the current WHO guidelines/criteria for defining normal, reduced or highly reduced inhibition in influenza B viruses based on in vitro data are not well aligned with the low in vivo OST efficacy observed for both wild-type influenza B viruses and those with reduced OST susceptibility.

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Oral poster abstractsMethods: 49 pregnancies that were diagnosed with a PF anomaly in our neurosonography unit between 2009-2010 were included in this study. Follow up was carried out and an amniocentesis was offered and a fetal MRI was performed based on our study protocol. Ages and Stages Questionnaires (ASQ) was performed to assess neurodevelopmental outcome on non-syndromic and chromosomally normal infants. An abnormal ASQ was considered if one or more areas were below the cut-off for the infant's age. Results: Our sample consisted on 29 Megacisterna magna (MM), 14 Blake's pouch cyst (BPC) and 6 Dandy-Walker malformation (DWM) that were excluded for analysis. Mean age at diagnosis was 27.6 weeks and mean PF size was 11.5 mm with 32% of the cases presenting an increasing size throughout the follow-up. Associated intra and extracranial malformations were found in 32.7% and 46.7% respectively 16.1% of the cases showed an abnormal karyotype. The evaluation of the neurodevelopment was performed at a mean age of 16.2 months (4.9-26.3) obtaining an abnormal score in 25% of the cases. No-significant differences were found between MM and BPC cases or in the presence or absence of associated intra or extracranial anomalies. Conclusions: Based on this preliminary report, it should be taken into consideration that MM and BPC can present an impaired neurodevelopment, although long-term follow-up studies and larger sample size studies should be delivered to confirm this notion. Objectives: The IFN is an internet-based ''virtual conference room'' collaboration of 21 academic institutions from 12 countries, established in January 2008. Monthly interactive case and topic discussions are presented by professionals in prenatal ultrasound and MRI, pediatric neurology and neurosurgery, genetics, and perinatal pathology. We wish to report the cumulative experience of our network over the past 3 years. Methods: Videoconferences lasted 75 min each, in which 2 or 3 institutions presented prenatally detected pathologies of the fetal CNS. High-resolution images were made available to participants. OP14.03Cases and topic presentations highlighted unusual presentations, diagnostic dilemmas, conceptual challenges pertaining to diagnosis and management, region-specific management diversity affected by local resources and abortion laws, and new methodologies. Results: 54 presentations were delivered in 29 meetings, including cerebral congenital anomalies (n = 10), posterior fossa anomalies (n = 8), disorders of neuronal migration (n = 2), infectious pathologies (n = 3), vascular pathologies (n = 5), metabolic disorders (n = 2), tumors (n = 5), genetic diseases (n = 3), spinal disorders (n = 3), fetal movement disorder (n = 1), and unknown etiologies (n = 3). Topic presentations focused on tractography, 3D ultrasound, comparison of ultrasound vs. MRI (n = 2), prognostication of spina bifida, first trimester CNS development, and diagnosis of posterior fossa anomalies. On a scale of 1 (disagree) to 5 (agree), respondents (n = 24) rated the fo...

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