451 research outputs found
Interaction of the Papillomavirus E2 Protein with Mitotic Chromosomes
AbstractThe bovine papillomavirus E2 transactivator protein is a multifunctional protein that activates viral transcription, cooperates in initiation of viral DNA replication, and is required for long-term episomal maintenance of viral genomes. We have shown previously that the E2 transactivator protein and bovine papillomavirus type 1 genomes are associated with mitotic chromosomes and have proposed that E2 links the genomes to cellular chromosomes to ensure segregation to daughter nuclei. In this study, we show that E2 is associated with cellular chromosomes at all stages of mitosis. We also further map the regions of E2 that are required for this association. The transactivation domain of E2 is necessary and sufficient to mediate the interaction with mitotic chromosomes; the DNA binding domain, and the flexible hinge region that separates the two domains, is not required. Furthermore, mutation of previously identified phosphorylation sites (serine residues 235, 298, and 301) has no effect on the ability of the E2 protein to bind mitotic chromosomes
Guard Automata for the Verification of Safety and Liveness of Distributed Algorithms
Distributed algorithms typically run over arbitrary many processes and may involve unboundedly many rounds, making the automated verification of their correctness challenging. Building on domain theory, we introduce a framework that abstracts infinite-state distributed systems that represent distributed algorithms into finite-state guard automata. The soundness of the approach corresponds to the Scott-continuity of the abstraction, which relies on the assumption that the distributed algorithms are layered. Guard automata thus enable the verification of safety and liveness properties of distributed algorithms
Human Bocavirus Infection, Canada
Human Bocavirus was detected in 18 (1.5%) of 1,209 respiratory specimens collected in 2003 and 2004 in Canada. The main symptoms of affected patients were cough (78%), fever (67%), and sore throat (44%). Nine patients were hospitalized; of these, 8 (89%) were <5 years of age
Guard Automata for the Verification of Safety and Liveness of Distributed Algorithms (long version)
Distributed algorithms typically run over arbitrary many processes and may involve unboundedly many rounds, making the automated verification of their correctness challenging. Building on domain theory, we introduce a framework that abstracts infinite-state distributed systems that represent distributed algorithms into finite-state guard automata. The soundness of the approach corresponds to the Scott-continuity of the abstraction, which relies on the assumption that the distributed algorithms are layered. Guard automata thus enable the verification of safety and liveness properties of distributed algorithms
Bioengineered embryoids mimic post-implantation development in vitro.
The difficulty of studying post-implantation development in mammals has sparked a flurry of activity to develop in vitro models, termed embryoids, based on self-organizing pluripotent stem cells. Previous approaches to derive embryoids either lack the physiological morphology and signaling interactions, or are unconducive to model post-gastrulation development. Here, we report a bioengineering-inspired approach aimed at addressing this gap. We employ a high-throughput cell aggregation approach to simultaneously coax mouse embryonic stem cells into hundreds of uniform epiblast-like aggregates in a solid matrix-free manner. When co-cultured with mouse trophoblast stem cell aggregates, the resulting hybrid structures initiate gastrulation-like events and undergo axial morphogenesis to yield structures, termed EpiTS embryoids, with a pronounced anterior development, including brain-like regions. We identify the presence of an epithelium in EPI aggregates as the major determinant for the axial morphogenesis and anterior development seen in EpiTS embryoids. Our results demonstrate the potential of EpiTS embryoids to study peri-gastrulation development in vitro
Congenital lung malformations: correlation between prenatal and postnatal imaging and pathological findings
Aim: Congenital lung malformations are a common finding during prenatal ultrasonography (US). Investigations were completed by means of prenatal MRI and postnatal computed tomographic (CT) scan. The purpose of this study was to compare these prenatal findings with postnatal findings and pathological findings after surgical resection.Materials and methods: Prenatal examinations and postnatal CTscan results of congenital malformations were compared with pathological findings.Results: From 2007 to 2013, 39 prenatally diagnosed congenital lung malformations were resected: 18 congenital cystic adenomatoid malformation, eight pulmonary sequestration, five bronchogenic cyst, one bronchial atresia and six complex lesions. Correlation between imaging and diagnosis was as follows: congenital cystic adenomatoid malformation was seen in 17/17 patients using postnatal CT, in 10/15 patients using prenatal MRI and in 17/18 patients using prenatal US. Correlation between imaging and diagnosis was as follows: bronchogenic cyst was seen in 3/5, 3/5 and 3/5 patients, pulmonary sequestration was seen in 7/9, 5/9 and 4/9 patients, and complex lesion was seen in 4/5, 3/6, and 2/6 patients using postnatal CT, prenatal MRI, and prenatal US, respectively. Overall, 32/37 cases were diagnosed by means of postnatal CT, 21/36 cases were diagnosed by means of prenatal MRI and 26/39 cases were diagnosed by means of prenatal US.Conclusion: Discordance between imaging data and definitive diagnosis is not rare. Our results suggest that postnatal CT scan is the most sensible and specific examination. Before birth, US seems better compared with MRI for description of the lesion. MRI seems to be useful in case of complex lesions and pulmonary sequestration.Keywords: congenital lung malformation, imaging, prenata
Swine Influenza (H3N2) Infection in a Child and Possible Community Transmission, Canada
Seropositivity to the same strain was demonstrated in the child and in multiple other community members
Incidence and prevalence of drug-resistant epilepsy : a systematic review and meta-analysis
Objective To evaluate the incidence and prevalence of drug-resistant epilepsy (DRE) as well as its predictors and correlates, we conducted a systematic review and meta-analysis of observational studies.
Methods Our protocol was registered with PROSPERO, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology reporting standards were followed. We searched MEDLINE, Embase, and Web of Science. We used a double arcsine transformation and random-effects models to perform our meta-analyses. We performed random-effects meta-regressions using study-level data.
Results Our search strategy identified 10,794 abstracts. Of these, 103 articles met our eligibility criteria. There was high interstudy heterogeneity and risk of bias. The cumulative incidence of DRE was 25.0% (95% confidence interval [CI]: 16.8–34.3) in child studies but 14.6% (95% CI: 8.8–21.6) in adult/mixed age studies. The prevalence of DRE was 13.7% (95% CI: 9.2–19.0) in population/community-based populations but 36.3% (95% CI: 30.4–42.4) in clinic-based cohorts. Meta-regression confirmed that the prevalence of DRE was higher in clinic-based populations and in focal epilepsy. Multiple predictors and correlates of DRE were identified. The most reported of these were having a neurologic deficit, an abnormal EEG, and symptomatic epilepsy. The most reported genetic predictors of DRE were polymorphisms of the ABCB1 gene.
Conclusions Our observations provide a basis for estimating the incidence and prevalence of DRE, which vary between populations. We identified numerous putative DRE predictors and correlates. These findings are important to plan epilepsy services, including epilepsy surgery, a crucial treatment option for people with disabling seizures and DRE
Triple Reassortant H3N2 Influenza A Viruses, Canada, 2005
Since January 2005, H3N2 influenza viruses have been isolated from pigs and turkeys throughout Canada and from a swine farmer and pigs on the same farm in Ontario. These are human/classical swine/avian reassortants similar to viruses that emerged in US pigs in 1998 but with a distinct human-lineage neuraminidase gene
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