307 research outputs found

    A combinatorial TIR1/AFB–Aux/IAA co-receptor system for differential sensing of auxin

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    The plant hormone auxin regulates virtually every aspect of plant growth and development. Auxin acts by binding the F-box protein transport inhibitor response 1 (TIR1) and promotes the degradation of the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) transcriptional repressors. Here we show that efficient auxin binding requires assembly of an auxin co-receptor complex consisting of TIR1 and an Aux/IAA protein. Heterologous experiments in yeast and quantitative IAA binding assays using purified proteins showed that different combinations of TIR1 and Aux/IAA proteins form co-receptor complexes with a wide range of auxin-binding affinities. Auxin affinity seems to be largely determined by the Aux/IAA. As there are 6 TIR1/AUXIN SIGNALING F-BOX proteins (AFBs) and 29 Aux/IAA proteins in Arabidopsis thaliana, combinatorial interactions may result in many co-receptors with distinct auxin-sensing properties. We also demonstrate that the AFB5–Aux/IAA co-receptor selectively binds the auxinic herbicide picloram. This co-receptor system broadens the effective concentration range of the hormone and may contribute to the complexity of auxin response

    GM and KM immunoglobulin allotypes in the Galician population: new insights into the peopling of the Iberian Peninsula

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    <p>Abstract</p> <p>Background</p> <p>The current genetic structure of Iberian populations has presumably been affected by the complex orography of its territory, the different people and civilizations that settled there, its ancient and complex history, the diverse and persistent sociocultural patterns in its different regions, and also by the effects of the Iberian Peninsula representing a refugium area after the last glacial maximum. This paper presents the first data on <it>GM </it>and <it>KM </it>immunoglobulin allotypes in the Galician population and, thus, provides further insights into the extent of genetic diversity in populations settled in the geographic extremes of the Cantabrian region of northern Spain. Furthermore, the genetic relationships of Galicians with other European populations have been investigated.</p> <p>Results</p> <p>Galician population shows a genetic profile for <it>GM </it>haplotypes that is defined by the high presence of the European Mediterranean <it>GM</it>*<it>3 23 5* </it>haplotype, and the relatively high incidence of the African marker <it>GM*1,17 23' 5*</it>. Data based on comparisons between Galician and other Spanish populations (mainly from the north of the peninsula) reveal a poor correlation between geographic and genetic distances (<it>r </it>= 0.30, <it>P </it>= 0.105), a noticeable but variable genetic distances between Galician and Basque subpopulations, and a rather close genetic affinity between Galicia and Valencia, populations which are geographically separated by a long distance and have quite dissimilar cultures and histories. Interestingly, Galicia occupies a central position in the European genetic map, despite being geographically placed at one extreme of the European continent, while displaying a close genetic proximity to Portugal, a finding that is consistent with their shared histories over centuries.</p> <p>Conclusion</p> <p>These findings suggest that the population of Galicia is the result of a relatively balanced mixture of European populations or of the ancestral populations that gave rise to them. This would support the importance of the migratory movements that have taken place in Europe over the course of recent human history and their effects on the European genetic landscape.</p

    Phylogeographic pattern and extensive mitochondrial DNA divergence disclose a species complex within the Chagas disease vector Triatoma dimidiata.

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    ABSTARCT: Previous studies have shown that "bioequivalent" generic products of vancomycin are less effective in vivo against Staphylococcus aureus than the innovator compound. Considering that suboptimal bactericidal effect has been associated with emergence of resistance, we aimed to assess in vivo the impact of exposure to innovator and generic products of vancomycin on S. aureus susceptibility. A clinical methicillin-resistant S. aureus (MRSA) strain from a liver transplant patient with persistent bacteremia was used for which MIC, minimum bactericidal concentration (MBC), and autolytic properties were determined. Susceptibility was also assessed by determining a population analysis profile (PAP) with vancomycin concentrations from 0 to 5 mg/liter. ICR neutropenic mice were inoculated in each thigh with ∼7.0 log(10) CFU. Treatment with the different vancomycin products (innovator and three generics; 1,200 mg/kg of body weight/day every 3 h) started 2 h later while the control group received sterile saline. After 24 h, mice were euthanized, and the thigh homogenates were plated. Recovered colonies were reinoculated to new groups of animals, and the exposure-recovery process was repeated until 12 cycles were completed. The evolution of resistance was assessed by PAP after cycles 5, 10, 11, and 12. The initial isolate displayed reduced autolysis and higher resistance frequencies than S. aureus ATCC 29213 but without vancomycin-intermediate S. aureus (VISA) subpopulations. After 12 cycles, innovator vancomycin had significantly reduced resistant subpopulations at 1, 2, and 3 mg/liter, while the generic products had enriched them progressively by orders of magnitude. The great capacity of generic vancomycin to select for less susceptible organisms raises concerns about the role of therapeutic inequivalence of any antimicrobial on the epidemiology of resistance worldwide

    A promising method for identifying cross-cultural differences in patient perspective: the use of Internet-based focus groups for content validation of new Patient Reported Outcome assessments

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    OBJECTIVES: This proof of concept (POC) study was designed to evaluate the use of an Internet-based bulletin board technology to aid parallel cross-cultural development of thematic content for a new set of patient-reported outcome measures (PROs). METHODS: The POC study, conducted in Germany and the United States, utilized Internet Focus Groups (IFGs) to assure the validity of new PRO items across the two cultures – all items were designed to assess the impact of excess facial oil on individuals' lives. The on-line IFG activities were modeled after traditional face-to-face focus groups and organized by a common 'Topic' Guide designed with input from thought leaders in dermatology and health outcomes research. The two sets of IFGs were professionally moderated in the native language of each country. IFG moderators coded the thematic content of transcripts, and a frequency analysis of code endorsement was used to identify areas of content similarity and difference between the two countries. Based on this information, draft PRO items were designed and a majority (80%) of the original participants returned to rate the relative importance of the newly designed questions. FINDINGS: The use of parallel cross-cultural content analysis of IFG transcripts permitted identification of the major content themes in each country as well as exploration of the possible reasons for any observed differences between the countries. Results from coded frequency counts and transcript reviews informed the design and wording of the test questions for the future PRO instrument(s). Subsequent ratings of item importance also deepened our understanding of potential areas of cross-cultural difference, differences that would be explored over the course of future validation studies involving these PROs. CONCLUSION: The use of IFGs for cross-cultural content development received positive reviews from participants and was found to be both cost and time effective. The novel thematic coding methodology provided an empirical platform on which to develop culturally sensitive questionnaire content using the natural language of participants. Overall, the IFG responses and thematic analyses provided a thorough evaluation of similarities and differences in cross-cultural themes, which in turn acted as a sound base for the development of new PRO questionnaires

    How is genetic testing evaluated? A systematic review of the literature

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    open8Given the rapid development of genetic tests, an assessment of their benefits, risks, and limitations is crucial for public health practice. We performed a systematic review aimed at identifying and comparing the existing evaluation frameworks for genetic tests. We searched PUBMED, SCOPUS, ISI Web of Knowledge, Google Scholar, Google, and gray literature sources for any documents describing such frameworks. We identified 29 evaluation frameworks published between 2000 and 2017, mostly based on the ACCE Framework (n = 13 models), or on the HTA process (n = 6), or both (n = 2). Others refer to the Wilson and Jungner screening criteria (n = 3) or to a mixture of different criteria (n = 5). Due to the widespread use of the ACCE Framework, the most frequently used evaluation criteria are analytic and clinical validity, clinical utility and ethical, legal and social implications. Less attention is given to the context of implementation. An economic dimension is always considered, but not in great detail. Consideration of delivery models, organizational aspects, and consumer viewpoint is often lacking. A deeper analysis of such context-related evaluation dimensions may strengthen a comprehensive evaluation of genetic tests and support the decision-making process.openPitini, Erica*; de Vito, Corrado; Marzuillo, Carolina; D’Andrea, Elvira; Rosso, Annalisa; Federici, Antonio; Di Maria, Emilio; Villari, PaoloPitini, Erica; de Vito, Corrado; Marzuillo, Carolina; D’Andrea, Elvira; Rosso, Annalisa; Federici, Antonio; Di Maria, Emilio; Villari, Paol

    Insects as Stem Engineers: Interactions Mediated by the Twig-Girdler Oncideres albomarginata chamela Enhance Arthropod Diversity

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    Background: Ecosystem engineering may influence community structure and biodiversity by controlling the availability of resources and/or habitats used by other organisms. Insect herbivores may act as ecosystem engineers but there is still poor understanding of the role of these insects structuring arthropod communities. Methodology/Principal Findings: We evaluated the effect of ecosystem engineering by the stem-borer Oncideres albomarginata chamela on the arthropod community of a tropical dry forest for three consecutive years. The results showed that ecosystem engineering by O. albomarginata chamela had strong positive effects on the colonization, abundance, species richness and composition of the associated arthropod community, and it occurred mainly through the creation of a habitat with high availability of oviposition sites for secondary colonizers. These effects cascade upward to higher trophic levels. Overall, ecosystem engineering by O. albomarginata chamela was responsible for nearly 95 % of the abundance of secondary colonizers and 82 % of the species richness. Conclusions/Significance: Our results suggest that ecosystem engineering by O. albomarginata chamela is a keystone process structuring an arthropod community composed by xylovores, predators and parasitoids. This study is the first to empirically demonstrate the effect of the ecosystem engineering by stem-boring insects on important attributes o

    Impact of COVID-19 pandemic on asthma symptoms and management: A prospective analysis of asthmatic children in Ecuador

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    Background Asthma affects up to 33% of children in Latin American settings. The ongoing COVID-19 pandemic has had a significant impact on access to and use of health services. We aimed to evaluate the impact of the COVID-19 lockdown on asthma exacerbations, medical facility visits, and use of asthma medications in children. Methods We used data from a prospective cohort of 213 children aged 5–17 years in 3 Ecuadorian cities and analysed the impact of the COVID-19 lockdown on asthma. Outcomes (asthma exacerbations, emergency room [ER] visits, planned and unplanned outpatient visits, and use of inhaled corticosteroids and Beta-2 agonists) were analysed using repeated Poisson counts (ie, number of events per participant before and during the COVID-19 lockdown). Results During compared to before lockdown: a) the number of asthma exacerbations remained constant (IRR, 0.87; 95% CI: 0.72–1.05; p = 0.152); b) outpatient visits (IRR 0.26, 95% CI 0.14–0.47, p < 0.001) declined 74% while ER visits declined 89% (IRR 0.11, 95% CI 0.04–0.32, p < 0.001); and c) there was no change in inhaled corticosteroids use (IRR 1.03, 95% CI 0.90–1.16, P = 0.699) while Beta-2 agonist use increased (IRR 1.32, 95% CI 1.10–1.58, P = 0.003). Conclusions In a cohort of Ecuadorian children with asthma, health services attendance decreased dramatically after COVID-19 lockdown, but asthma exacerbations and use of inhaled corticosteroids were unchanged. Future analyses will address the question of the effect of SARS-CoV-2 infection on asthma exacerbations and control in this paediatric population
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