901 research outputs found

    A cDNA microarray approach to decipher sunflower (Helianthus annuus) responses to the necrotrophic fungus Phoma macdonaldii

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    To identify the genes involved in the partial resistance of sunflower (Helianthus annuus) to the necrotrophic fungus Phoma macdonaldii, we developed a 1000‐element cDNA microarray containing carefully chosen genes putatively involved in primary metabolic pathways, signal transduction and biotic stress responses. A two‐pass general linear model was used to normalize the data and then to detect differentially expressed genes. This method allowed us to identify 38 genes differentially expressed among genotypes, treatments and times, mainly belonging to plant defense, signaling pathways and amino acid metabolism. Based on a set of genes whose differential expression was highly significant, we propose a model in which negative regulation of a dual‐specificity MAPK phosphatase could be implicated in sunflower defense mechanisms against the pathogen. The resulting activation of the MAP kinase cascade could subsequently trigger defense responses (e.g. thaumatin biosynthesis and phenylalanine ammonia lyase activation), under the control of transcription factors belonging to MYB and WRKY families. Concurrently, the activation of protein phosphatase 2A (PP2A), which is implicated in cell death inhibition, could limit pathogen development. The results reported here provide a valuable first step towards the understanding and analysis of the P. macdonaldii–sunflower interaction

    A Gamma-Herpesvirus Glycoprotein Complex Manipulates Actin to Promote Viral Spread

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    Viruses lack self-propulsion. To move in multi-cellular hosts they must therefore manipulate infected cells. Herpesviruses provide an archetype for many aspects of host manipulation, but only for alpha-herpesviruses in is there much information about they move. Other herpesviruses are not necessarily the same. Here we show that Murine gamma-herpesvirus-68 (MHV-68) induces the outgrowth of long, branched plasma membrane fronds to create an intercellular network for virion traffic. The fronds were actin-based and RhoA-dependent. Time-lapse imaging showed that the infected cell surface became highly motile and that virions moved on the fronds. This plasma membrane remodelling was driven by the cytoplasmic tail of gp48, a MHV-68 glycoprotein previously implicated in intercellular viral spread. The MHV-68 ORF58 was also required, but its role was simply transporting gp48 to the plasma membrane, since a gp48 mutant exported without ORF58 did not require ORF58 to form membrane fronds either. Together, gp48/ORF58 were sufficient to induce fronds in transfected cells, as were the homologous BDLF2/BMRF2 of Epstein-Barr virus. Gp48/ORF58 therefore represents a conserved module by which gamma-herpesviruses rearrange cellular actin to increase intercellular contacts and thereby promote their spread

    The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

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    Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

    Performance deficits of NK1 receptor knockout mice in the 5 choice serial reaction time task: effects of d Amphetamine, stress and time of day.

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    Background The neurochemical status and hyperactivity of mice lacking functional substance P-preferring NK1 receptors (NK1R-/-) resemble abnormalities in Attention Deficit Hyperactivity Disorder (ADHD). Here we tested whether NK1R-/- mice express other core features of ADHD (impulsivity and inattentiveness) and, if so, whether they are diminished by d-amphetamine, as in ADHD. Prompted by evidence that circadian rhythms are disrupted in ADHD, we also compared the performance of mice that were trained and tested in the morning or afternoon. Methods and Results The 5-Choice Serial Reaction-Time Task (5-CSRTT) was used to evaluate the cognitive performance of NK1R-/- mice and their wildtypes. After training, animals were tested using a long (LITI) and a variable (VITI) inter-trial interval: these tests were carried out with, and without, d-amphetamine pretreatment (0.3 or 1 mg/kg i.p.). NK1R-/- mice expressed greater omissions (inattentiveness), perseveration and premature responses (impulsivity) in the 5-CSRTT. In NK1R-/- mice, perseveration in the LITI was increased by injection-stress but reduced by d-amphetamine. Omissions by NK1R-/- mice in the VITI were unaffected by d-amphetamine, but premature responses were exacerbated by this psychostimulant. Omissions in the VITI were higher, overall, in the morning than the afternoon but, in the LITI, premature responses of NK1R-/- mice were higher in the afternoon than the morning. Conclusion In addition to locomotor hyperactivity, NK1R-/- mice express inattentiveness, perseveration and impulsivity in the 5-CSRTT, thereby matching core criteria for a model of ADHD. Because d-amphetamine reduced perseveration in NK1R-/- mice, this action does not require functional NK1R. However, the lack of any improvement of omissions and premature responses in NK1R-/- mice given d-amphetamine suggests that beneficial effects of this psychostimulant in other rodent models, and ADHD patients, need functional NK1R. Finally, our results reveal experimental variables (stimulus parameters, stress and time of day) that could influence translational studies

    Group Visits: Promoting Adherence to Diabetes Guidelines

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    BACKGROUND: Current diabetes management guidelines offer blueprints for providers, yet type 2 diabetes control is often poor in disadvantaged populations. The group visit is a new treatment modality originating in managed care for efficient service delivery to patients with chronic health problems. Group visits offer promise for delivering care to diabetic patients, as visits are lengthier and can be more frequent, more organized, and more educational. OBJECTIVE: To evaluate the effect of group visits on clinical outcomes, concordance with 10 American Diabetes Association (ADA) guidelines [American Diabetes Association, Diabetes Care, 28:S4–36, 2004] and 3 United States Preventive Services Task Force (USPSTF) cancer screens [U.S. Preventive Services Task Force, http://www.ahrq.gov/clinic/uspstf/resource.htm, 2003]. RESEARCH DESIGN AND METHODS: A 12-month randomized controlled trial of 186 diabetic patients comparing care in group visits with care in the traditional patient–physician dyad. Clinical outcomes (HbA1c, blood pressure [BP], lipid profiles) were assessed at 6 and 12 months and quality of care measures (adherence to 10 ADA guidelines and 3 USPSTF cancer screens) at 12 months. RESULTS: At both measurement points, HbA1c, BP, and lipid levels did not differ significantly for patients attending group visits versus those in usual care. At 12 months, however, patients receiving care in group visits exhibited greater concordance with ADA process-of-care indicators (p < .0001) and higher screening rates for cancers of the breast (80 vs. 68%, p = .006) and cervix (80 vs 68%, p = .019). CONCLUSIONS: Group visits can improve the quality of care for diabetic patients, but modifications to the content and style of group visits may be necessary to achieve improved clinical outcomes

    An Essential Role for the Proximal but Not the Distal Cytoplasmic Tail of Glycoprotein M in Murid Herpesvirus 4 Infection

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    Murid herpesvirus-4 (MuHV-4) provides a tractable model with which to define common, conserved features of gamma-herpesvirus biology. The multi-membrane spanning glycoprotein M (gM) is one of only 4 glycoproteins that are essential for MuHV-4 lytic replication. gM binds to gN and is thought to function mainly secondary envelopment and virion egress, for which several predicted trafficking motifs in its C-terminal cytoplasmic tail could be important. We tested the contribution of the gM cytoplasmic tail to MuHV-4 lytic replication by making recombinant viruses with varying C-terminal deletions. Removing an acidic cluster and a distal YXXΦ motif altered the capsid distribution somewhat in infected cells but had little effect on virus replication, either in vitro or in vivo. In contrast, removing a proximal YXXΦ motif as well completely prevented productive replication. gM was still expressed, but unlike its longer forms showed only limited colocalization with co-transfected gN, and in the context of whole virus appeared to support gN expression less well. We conclude that some elements of the gM cytoplasmic tail are dispensible for MuHV-4 replication, but the tail as a whole is not

    An improved parameter estimation and comparison for soft tissue constitutive models containing an exponential function

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    Motivated by the well-known result that stiffness of soft tissue is proportional to the stress, many of the constitutive laws for soft tissues contain an exponential function. In this work, we analyze properties of the exponential function and how it affects the estimation and comparison of elastic parameters for soft tissues. In particular, we find that as a consequence of the exponential function there are lines of high covariance in the elastic parameter space. As a result, one can have widely varying mechanical parameters defining the tissue stiffness but similar effective stress–strain responses. Drawing from elementary algebra, we propose simple changes in the norm and the parameter space, which significantly improve the convergence of parameter estimation and robustness in the presence of noise. More importantly, we demonstrate that these changes improve the conditioning of the problem and provide a more robust solution in the case of heterogeneous material by reducing the chances of getting trapped in a local minima. Based upon the new insight, we also propose a transformed parameter space which will allow for rational parameter comparison and avoid misleading conclusions regarding soft tissue mechanics

    Evaluation of adjunctive HPV testing by Hybrid Capture II(® )in women with minor cytological abnormalities for the diagnosis of CIN2/3 and cost comparison with colposcopy

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    BACKGROUND: As a proportion of high grade cervical intraepithelial neoplasia (CIN2/3) are associated with equivocal cervical smears, which show borderline or mild dyskaryosis, follow up with repeat smears, colposcopy and biopsy is required. Since infection with oncogenic Human Papilloma Virus (HR HPV) has been found to be associated with the development of cervical cancer, HRHPV testing appears to be an alternative. OBJECTIVE: The present study assesses if HRHPV testing can predict CIN2/3 in women referred for mild dyskaryosis and borderline cytological changes in an health authority with a referral policy to colposcopy after one single mild dyskaryotic Pap smear. STUDY DESIGN: The HPV DNA Hybrid Capture II (Digene/Abbott, Maidenhead) was evaluated on 110 consenting women with mild dyskaryosis and 23 women with persistent borderline changes, who were referred for colposcopy between May and November 2001. A cost comparison between two referral policies was performed. RESULTS: CIN2/3 was diagnosed histologically in 30 of 133 women (22%) with minor cytological abnormalities. As the Receiver Operator Characteristics plot suggested a cut-off of 3 pg/ml the HRHPV HCII was evaluated at 3 RLU (relative light units) and at the manufacturer's recommendation of 1 RLU. At both cut-offs sensitivity and negative predictive value were high at 97%. Specificity was low at 37% at a cut-off of 1 pg/ml and 46% at a cut-off of 3 RLU. To remain cost neutral in comparison to immediate colposcopy the costs for one HR HPV HC II must not exceed £34.37 per test at a cut off of 3 pg/ml. CONCLUSION: The negative likelihood ratio (NLR) was of good diagnostic value with 0.089 at 1 RLU and 0.072 at 3 RLU, which reduces the post-test probability for CIN2/3 to 2% in this population. Women with minor cytological disorders can be excluded from colposcopy on a negative HR HPV result. Specificity can be improved by restricting HR HPV testing to women with persistent borderline cytological changes or to women over 30 years

    Multiple Functions for ORF75c in Murid Herpesvirus-4 Infection

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    All gamma-herpesviruses encode at least one homolog of the cellular enzyme formyl-glycineamide-phosphoribosyl-amidotransferase. Murid herpesvirus-4 (MuHV-4) encodes 3 (ORFs 75a, 75b and 75c), suggesting that at least some copies have acquired new functions. Here we show that the corresponding proteins are all present in virions and localize to infected cell nuclei. Despite these common features, ORFs 75a and 75b did not substitute functionally for a lack of ORF75c, as ORF75c virus knockouts were severely impaired for lytic replication in vitro and for host colonization in vivo. They showed 2 defects: incoming capsids failed to migrate to the nuclear margin following membrane fusion, and genomes that did reach the nucleus failed to initiate normal gene expression. The latter defect was associated with a failure of in-coming virions to disassemble PML bodies. The capsid transport deficit seemed to be functionally more important, since ORF75c− MuHV-4 infected both PML+ and PML− cells poorly. The original host enzyme has therefore evolved into a set of distinct and multi-functional viral tegument proteins. One important function is moving incoming capsids to the nuclear margin for viral genome delivery
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