111 research outputs found

    Ī±<sub>1L</sub>-adrenoceptors mediate contraction of human erectile tissue

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    Ī±1-adrenoceptor antagonists can impact upon sexual function and have potential in the treatment of erectile dysfunction. Human erectile tissue contains predominantly Ī±1A-adrenoceptors, and here we examined whether contractions of this tissue are mediated by the functional phenotype, the Ī±1L-adrenoceptor. Functional experiments using subtype selective agonists and antagonists, along with radioligand ([3H]tamsulosin) binding assays, were used to determine the Ī±1-adrenoceptor population. A61603, a Ī±1A-adrenoceptor agonist, was a full agonist with a potency 21-fold greater than that of noradrenaline. The Ī±1A- and Ī±1D-adrenoceptor antagonist tamsulosin antagonized noradrenaline responses with high affinity (pKDĀ =Ā 9.7Ā Ā±Ā 0.3), whilst BMY7378 (100Ā nM) (Ī±1D-adrenoceptor antagonist) failed to antagonize responses. In contrast, relatively low affinity estimates were obtained for both prazosin (pKDĀ =Ā 8.2Ā Ā±Ā 0.1) and RS17053 (pKDĀ =Ā 6.9Ā Ā±Ā 0.2), antagonists which discriminate between the Ī±1A- and Ī±1L-adrenoceptors. [3H]Tamsulosin bound with high affinity to the receptors of human erectile tissue (pKDĀ =Ā 10.3Ā Ā±Ā 0.1) with a receptor density of 28.1Ā Ā±Ā 1.4Ā fmolĀ mgāˆ’1 protein. Prazosin displacement of [3H]tamsulosin binding revealed a single homogenous population of binding sites with a relatively low affinity for prazosin (pKiĀ =Ā 8.9). Taken together these data confirm that the receptor mediating contraction in human erectile tissue has the pharmacological properties of the Ī±1L-adrenoceptor. Keywords: Erectile tissue, Ī±1-adrenoceptor subtypes, Ī±1L-adrenoceptor, Tamsulosin, Prazosi

    Characterisation of the R2R3 Myb subgroup 9 family of transcription factors in tomato

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    Tomato (Solanum lycopersicum) has many epidermal cell outgrowths including conical petal cells and multiple types of trichomes. These include the anther-specific trichome mesh which holds the anthers connate. The R2R3 Myb Subgroup 9 family of transcription factors is involved in development of epidermal cell outgrowths throughout the angiosperms. No previous study has examined all members of this transcription factor family in a single species. All 7 R2R3 Myb Subgroup 9 genes were isolated from tomato. They were ectopically expressed in tobacco to assess their ability to induce epidermal cell outgrowth. Endogenous expression patterns were examined by semi-quantitative RT-PCR at different stages of floral development relative to the development of anther trichomes. We report variation in the degree of epidermal cell outgrowth produced in transgenic tobacco by each ectopically expressed gene. Based on expression profile and ectopic activity, SlMIXTA-2 is likely involved in the production of leaf trichomes. SlMIXTA-2 is expressed most strongly in the leaves, and not expressed in the floral tissue. SlMYB17-2 is the best candidate for the regulation of the anther trichome mesh. SlMYB17-2 is expressed strongly in the floral tissue and produces a clear phenotype of epidermal cell outgrowths when ectopically expressed in tobacco. Analysis of the phenotypes of transgenic plants ectopically expressing all 7 genes has revealed the different extent to which members of the same transcription factor subfamily can induce cellular outgrowth

    Automatic categorization of diverse experimental information in the bioscience literature

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    Background: Curation of information from bioscience literature into biological knowledge databases is a crucial way of capturing experimental information in a computable form. During the biocuration process, a critical first step is to identify from all published literature the papers that contain results for a specific data type the curator is interested in annotating. This step normally requires curators to manually examine many papers to ascertain which few contain information of interest and thus, is usually time consuming. We developed an automatic method for identifying papers containing these curation data types among a large pool of published scientific papers based on the machine learning method Support Vector Machine (SVM). This classification system is completely automatic and can be readily applied to diverse experimental data types. It has been in use in production for automatic categorization of 10 different experimental datatypes in the biocuration process at WormBase for the past two years and it is in the process of being adopted in the biocuration process at FlyBase and the Saccharomyces Genome Database (SGD). We anticipate that this method can be readily adopted by various databases in the biocuration community and thereby greatly reducing time spent on an otherwise laborious and demanding task. We also developed a simple, readily automated procedure to utilize training papers of similar data types from different bodies of literature such as C. elegans and D. melanogaster to identify papers with any of these data types for a single database. This approach has great significance because for some data types, especially those of low occurrence, a single corpus often does not have enough training papers to achieve satisfactory performance. Results: We successfully tested the method on ten data types from WormBase, fifteen data types from FlyBase and three data types from Mouse Genomics Informatics (MGI). It is being used in the curation work flow at WormBase for automatic association of newly published papers with ten data types including RNAi, antibody, phenotype, gene regulation, mutant allele sequence, gene expression, gene product interaction, overexpression phenotype, gene interaction, and gene structure correction. Conclusions: Our methods are applicable to a variety of data types with training set containing several hundreds to a few thousand documents. It is completely automatic and, thus can be readily incorporated to different workflow at different literature-based databases. We believe that the work presented here can contribute greatly to the tremendous task of automating the important yet labor-intensive biocuration effort

    Virus Infection of Plants Alters Pollinator Preference: A Payback for Susceptible Hosts?

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    Plant volatiles play important roles in attraction of certain pollinators and in host location by herbivorous insects. Virus infection induces changes in plant volatile emission profiles, and this can make plants more attractive to insect herbivores, such as aphids, that act as viral vectors. However, it is unknown if virus-induced alterations in volatile production affect plant-pollinator interactions. We found that volatiles emitted by cucumber mosaic virus (CMV)-infected tomato (Solanum lycopersicum) and Arabidopsis thaliana plants altered the foraging behaviour of bumblebees (Bombus terrestris). Virus-induced quantitative and qualitative changes in blends of volatile organic compounds emitted by tomato plants were identified by gas chromatography-coupled mass spectrometry. Experiments with a CMV mutant unable to express the 2b RNA silencing suppressor protein and with Arabidopsis silencing mutants implicate microRNAs in regulating emission of pollinator-perceivable volatiles. In tomato, CMV infection made plants emit volatiles attractive to bumblebees. Bumblebees pollinate tomato by 'buzzing' (sonicating) the flowers, which releases pollen and enhances self-fertilization and seed production as well as pollen export. Without buzz-pollination, CMV infection decreased seed yield, but when flowers of mock-inoculated and CMV-infected plants were buzz-pollinated, the increased seed yield for CMV-infected plants was similar to that for mock-inoculated plants. Increased pollinator preference can potentially increase plant reproductive success in two ways: i) as female parents, by increasing the probability that ovules are fertilized; ii) as male parents, by increasing pollen export. Mathematical modeling suggested that over a wide range of conditions in the wild, these increases to the number of offspring of infected susceptible plants resulting from increased pollinator preference could outweigh underlying strong selection pressures favoring pathogen resistance, allowing genes for disease susceptibility to persist in plant populations. We speculate that enhanced pollinator service for infected individuals in wild plant populations might provide mutual benefits to the virus and its susceptible hosts.Major funding for this project was provided to JPC by the Leverhulme Trust (Grant numbers RPG-2012-667 and F/09741/F: https://www. leverhulme.ac.uk/). Additional funding to JPC and studentships to support JHW and SCG came from the Biotechnological and Biological Sciences Research Council (Grant number BB/J011762/1: http://www.bbsrc.ac.uk/). Other additional funding was obtained from the Isaac Newton Trust (http://www. newtontrust.cam.ac.uk/: grant number 12.07/I to AMM).This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/:10.1371/journal.ppat.100579

    An Arabidopsis flavonoid transporter is required for anther dehiscence and pollen development

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    FLOWER FLAVONOID TRANSPORTER (FFT) encodes a multidrug and toxin efflux family transporter in Arabidopsis thaliana. FFT (AtDTX35) is highly transcribed in floral tissues, the transcript being localized to epidermal guard cells, including those of the anthers, stigma, siliques and nectaries. Mutant analysis demonstrates that the absence of FFT transcript affects flavonoid levels in the plant and that the altered flavonoid metabolism has wide-ranging consequences. Root growth, seed development and germination, and pollen development, release and viability are all affected. Spectrometry of mutant versus wild-type flowers shows altered levels of a glycosylated flavonol whereas anthocyanin seems unlikely to be the substrate as previously speculated. Thus, as well as adding FFT to the incompletely described flavonoid transport network, it is found that correct reproductive development in Arabidopsis is perturbed when this particular transporter is missing

    Collaborating with front-line healthcare professionals: the clinical and cost effectiveness of a theory based approach to the implementation of a national guideline

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    Background Clinical guidelines are an integral part of healthcare. Whilst much progress has been made in ensuring that guidelines are well developed and disseminated, the gap between routine clinical practice and current guidelines often remains wide. A key reason for this gap is that implementation of guidelines typically requires a change in the behaviour of healthcare professionals ā€“ but the behaviour change component is often overlooked. We adopted the Theoretical Domains Framework Implementation (TDFI) approach for supporting behaviour change required for the uptake of a national patient safety guideline to reduce the risk of feeding through misplaced nasogastric tubes. Methods The TDFI approach was used in a pre-post study in three NHS hospitals with a fourth acting as a control (with usual care and no TDFI). The target behavior identified for change was to increase the use of pH testing as the first line method for checking the position of a nasogastric tube. Repeat audits were undertaken in each hospital following intervention implementation. We used Zouā€™s modified Poisson regression approach with robust standard errors to estimate risk ratios for the use of pH testing. The projected return on investment (ROI) was also calculated. Results Following intervention implementation, the use of pH first line increased significantly across intervention hospitals [risk ratio (95% CI) ranged from 3.1 (1.14 to8.43) pā€‰<ā€‰.05, to 8.14 (3.06 to21.67) pā€‰<ā€‰.001] compared to the control hospital, which remained unchanged [risk ratio (CI)ā€‰=ā€‰.77 (.47-1.26) pā€‰=ā€‰.296]. The estimated savings and costs in the first year were Ā£2.56 million and Ā£1.41 respectively, giving an ROI of 82%, and this was projected to increase to 270% over five years. Conclusion The TDFI approach improved the uptake of a patient safety guideline across three hospitals. The TDFI approach is clinically and cost effective in comparison to the usual practice

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Exacerbated leishmaniasis caused by a viral endosymbiont can be prevented by immunization with Its viral capsid

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    Recent studies have shown that a cytoplasmic virus called Leishmaniavirus (LRV) is present in some Leishmania species and acts as a potent innate immunogen, aggravating lesional inflammation and development in mice. In humans, the presence of LRV in Leishmania guyanensis and in L. braziliensis was significantly correlated with poor treatment response and symptomatic relapse. So far, no clinical effort has used LRV for prophylactic purposes. In this context, we designed an original vaccine strategy that targeted LRV nested in Leishmania parasites to prevent virus-related complications. To this end, C57BL/6 mice were immunized with a recombinant LRV1 Leishmania guyanensis viral capsid polypeptide formulated with a T helper 1-polarizing adjuvant. LRV1-vaccinated mice had significant reduction in lesion size and parasite load when subsequently challenged with LRV1+ Leishmania guyanensis parasites. The protection conferred by this immunization could be reproduced in naĆÆve mice via T-cell transfer from vaccinated mice but not by serum transfer. The induction of LRV1 specific T cells secreting IFN-Ī³ was confirmed in vaccinated mice and provided strong evidence that LRV1-specific protection arose via a cell mediated immune response against the LRV1 capsid. Our studies suggest that immunization with LRV1 capsid could be of a preventive benefit in mitigating the elevated pathology associated with LRV1 bearing Leishmania infections and possibly avoiding symptomatic relapses after an initial treatment. This novel anti-endosymbiotic vaccine strategy could be exploited to control other infectious diseases, as similar viral infections are largely prevalent across pathogenic pathogens and could consequently open new vaccine opportunities
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