44 research outputs found

    Placental syncytiotrophoblast constitutes a major barrier to vertical transmission of Listeria monocytogenes.

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    Listeria monocytogenes is an important cause of maternal-fetal infections and serves as a model organism to study these important but poorly understood events. L. monocytogenes can infect non-phagocytic cells by two means: direct invasion and cell-to-cell spread. The relative contribution of each method to placental infection is controversial, as is the anatomical site of invasion. Here, we report for the first time the use of first trimester placental organ cultures to quantitatively analyze L. monocytogenes infection of the human placenta. Contrary to previous reports, we found that the syncytiotrophoblast, which constitutes most of the placental surface and is bathed in maternal blood, was highly resistant to L. monocytogenes infection by either internalin-mediated invasion or cell-to-cell spread. Instead, extravillous cytotrophoblasts-which anchor the placenta in the decidua (uterine lining) and abundantly express E-cadherin-served as the primary portal of entry for L. monocytogenes from both extracellular and intracellular compartments. Subsequent bacterial dissemination to the villous stroma, where fetal capillaries are found, was hampered by further cellular and histological barriers. Our study suggests the placenta has evolved multiple mechanisms to resist pathogen infection, especially from maternal blood. These findings provide a novel explanation why almost all placental pathogens have intracellular life cycles: they may need maternal cells to reach the decidua and infect the placenta

    SRFR1 Negatively Regulates Plant NB-LRR Resistance Protein Accumulation to Prevent Autoimmunity

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    Plant defense responses need to be tightly regulated to prevent auto-immunity, which is detrimental to growth and development. To identify negative regulators of Resistance (R) protein-mediated resistance, we screened for mutants with constitutive defense responses in the npr1-1 background. Map-based cloning revealed that one of the mutant genes encodes a conserved TPR domain-containing protein previously known as SRFR1 (SUPPRESSOR OF rps4-RLD). The constitutive defense responses in the srfr1 mutants in Col-0 background are suppressed by mutations in SNC1, which encodes a TIR-NB-LRR (Toll Interleukin1 Receptor-Nucleotide Binding-Leu-Rich Repeat) R protein. Yeast two-hybrid screens identified SGT1a and SGT1b as interacting proteins of SRFR1. The interactions between SGT1 and SRFR1 were further confirmed by co-immunoprecipitation analysis. In srfr1 mutants, levels of multiple NB-LRR R proteins including SNC1, RPS2 and RPS4 are increased. Increased accumulation of SNC1 is also observed in the sgt1b mutant. Our data suggest that SRFR1 functions together with SGT1 to negatively regulate R protein accumulation, which is required for preventing auto-activation of plant immunity

    Low back pain in 17 year olds has substantial impact and represents an important public health disorder: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Prevalence of low back pain (LBP) rises rapidly during adolescence, reaching adult levels by the age of 18. It has been suggested that adolescent LBP is benign with minimal impact, despite limited evidence.</p> <p>Methods</p> <p>The aim of this study was to investigate the impact of LBP and the influence of chronicity, gender and presence of other spinal pain comorbidities at age 17. Subjects (n = 1283) were categorised according to experiencing current and chronic LBP, gender and presence of other areas of spinal pain. LBP impact was ascertained via questions regarding seeking professional assistance, using medication, missing school/work, limited normal or recreational physical activity and health related quality of life (HRQOL).</p> <p>Results</p> <p>12.3% of participants reported current but not chronic LBP, while 19.9% reported current chronic LBP. LBP was more commonly reported by females than males. Other spinal pain comorbidities were common in the LBP groups. Impact was greater in subjects with chronic LBP, in females and in those with other spinal pain comorbidities.</p> <p>Conclusion</p> <p>LBP, and particularly chronic LBP, has a significant negative impact at 17 years. It is commonly associated with care seeking, medication use, school absenteeism, and reduced HRQOL. These findings support that adolescent LBP is an important public health issue that requires attention.</p

    Galaxy And Mass Assembly (GAMA): end of survey report and data release 2

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    The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low-redshift galaxies. Covering an area of ~286 deg^2 (split among five survey regions) down to a limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238,000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm - 1 m. Here we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component S\'ersic fits, stellar masses, Hα\alpha-derived star formation rates, environment information, and group properties for all galaxies with r < 19.0 mag in two of our survey regions, and for all galaxies with r < 19.4 mag in a third region (72,225 objects in total). The database serving these data is available at http://www.gama-survey.org/

    Osteoporosis: the current status of mesenchymal stem cell-based therapy

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    Do community pharmacists have the attitudes and knowledge to support evidence based self-management of low back pain?

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    Background In many countries, community pharmacists can be consulted without appointment in a large number of convenient locations. They are in an ideal position to give advice to patients at the onset of low back pain and also reinforce advice given by other healthcare professionals. There is little specific information about the quality of care provided in the pharmacy for people with back pain. The main objectives of this survey were to determine the attitudes, knowledge and reported practice of English pharmacists advising people who present with acute or chronic low back pain. Methods A questionnaire was designed for anonymous self-completion by pharmacists attending continuing education sessions. Demographic questions were designed to allow comparison with a national pharmacy workforce survey. Attitudes were measured with the Back Beliefs Questionnaire (BBQ) and questions based on the Working Backs Scotland campaign. Questions about the treatment of back pain in the community pharmacy were written (or adapted) to reflect and characterise the nature of practice. In response to two clinical vignettes, respondents were asked to select proposals that they would recommend in practice. Results 335 responses from community pharmacists were analysed. Middle aged pharmacists, women, pharmacy managers and locums were over-represented compared to registration and workforce data. The mean (SD) BBQ score for the pharmacists was 31.37 (5.75), which was slightly more positive than in similar surveys of other groups. Those who had suffered from back pain seem to demonstrate more confidence (fewer negative feelings, more advice opportunities and better advice provision) in their perception of advice given in the pharmacy. Awareness of written information that could help to support practice was low. Reponses to the clinical vignettes were generally in line with the evidence base. Pharmacists expressed some caution about recommending activity. Most respondents said they would benefit from more education about back pain. Conclusion Those sampled generally expressed positive attitudes about back pain and were able to offer evidence based advice. Pharmacists may benefit from training to increase their ability and confidence to offer support for self-care in back pain. Further research would be useful to clarify the representativeness of the sample

    Micronutrient deficiencies in African soils and the human nutritional nexus: opportunities with staple crops

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    A synthesis of available agronomic datasets and peer-reviewed scientific literature was conducted to: (1) assess the status of micronutrients in sub-Saharan Africa (SSA) arable soils, (2) improve the understanding of the relations between soil quality/management and crop nutritional quality and (3) evaluate the potential profitability of application of secondary and micronutrients to key food crops in SSA, namely maize (Zea mays L.), beans (Phaseolus spp. and Vicia faba L.), wheat (Triticum aestivum L.) and rice (Oryza sativa L.). We found that there is evidence of widespread but varying micronutrient deficiencies in SSA arable soils and that simultaneous deficiencies of multiple elements (co-occurrence) are prevalent. Zinc (Zn) predominates the list of micronutrients that are deficient in SSA arable soils. Boron (B), iron (Fe), molybdenum (Mo) and copper (Cu) deficiencies are also common. Micronutrient fertilization/agronomic biofortification increases micronutrient concentrations in edible plant organs, and it was profitable to apply fertilizers containing micronutrient elements in 60-80% of the cases. However, both the plant nutritional quality and profit had large variations. Possible causes of this variation may be differences in crop species and cultivars, fertilizer type and application methods, climate and initial soil conditions, and soil chemistry effects on nutrient availability for crop uptake. Therefore, micronutrient use efficiency can be improved by adapting the rates and types of fertilizers to site-specific soil and management conditions. To make region-wide nutritional changes using agronomic biofortification, major policy interventions are needed
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