216 research outputs found

    Isolation and characterization of galactinol synthases from hybrid poplar

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    The raffinose family of oligosaccharides (RFOs) serve as transport carbohydrates in the phloem, storage compounds in sink tissues, and putative biological agents to combat both abiotic and biotic stress in several plant species. To investigate further the functional roles of this class of compounds in trees, two cDNAs encoding galactinol synthase (GolS, EC 2.4.1.123), which catalyses the first step in the biosynthesis of RFOs, were identified and cloned from hybrid poplar (Populus alba×grandidentata). Phylogenetic analyses of the Populus GolS isoforms with other known GolS proteins suggested a putative role for these enzymes during biotic or abiotic stress in hybrid poplar. The predicted protein sequences of both isoforms (Pa×gGolSI and Pa×gGolSII) showed characteristics of GolS proteins from other species, including a serine phosphorylation site and the ASAAP pentapeptide hydrophobic domain. Kinetic analyses of recombinant Pa×gGolSI and Pa×gGolSII resulted in Km values for UPD-galactose of 0.80 and 0.65 mM and Vmax values of 657.5 and 1245 nM min−1, respectively. Pa×gGolSI inherently possessed a broader pH and temperature range when compared with Pa×gGolSII. Interestingly, spatial and temporal expression analyses revealed that Pa×gGolSII transcript levels varied seasonally, while Pa×gGolSI did not, implying temperature-regulated transcriptional control of this gene in addition to the observed thermosensitivity of the respective enzyme. This evidence suggested that Pa×gGolSI may be involved in basic metabolic activities such as storage, while Pa×gGolSII is probably involved in seasonal mobilization of carbohydrates

    Learning through exchange about organic agriculture - case of Europe and Australia

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    LEAFSE is the catch word for an innovative program of exchange study for young Australians and Europeans, with organic agriculture as the focal point of their Masters level studies. Two years ago, the European Commission and the Australian Department of Education, Science and Technology (DEST) came up with the call for applications for a pilot project to support international mobility of tertiary students between the two continents. The grand aims set for the exchange included providing students with an international outlook and a range of perspectives, preparing them for the global marketplace, enable their understanding and empathy for different cultures and traditions and foster exchange of information. A number of us with an interest and an already existing academic network in organic agriculture proposed LEAFSE - Learning through Exchange - Agriculture, Food Systems and Environment, a winning project, which was chosen as the single pilot project from a field of well over a dozen contenders. Within the broader theme of Agriculture, Food Systems and Environment, we named organic farming as the focal point of the exchange, and we were aware of the immense possibilities for learning through exchange inter-continentally in this field. Under this project, Master's level students from EU study for a semester at a partner university in Australia, and students from Australia study for a semester at a partner university in EU. The partners in the programme are, from Europe: • The Royal Veterinary and Agricultural University, Denmark • University of Wales, Aberystwyth, United Kingdom • Wageningen University and Research Centre, The Netherlands • University of Kassel, Witzenhausen, Germany, and from Australia: • University of Western Sydney, New South Wales • University of New England, New South Wales • University of Western Australia, Western Australia • University of Queensland, Queensland The project has an innovative but manageable framework for mobility of the students, a joint programme of study which incorporates many novel elements including holistic thinking, experiential and integrated learning and use of newer tools of communication technologies, and above all, a structure that fosters a high degree of inter-cultural understanding and network building. When completed, the pilot phase of the project would have enabled exchange of 36 students from each continent, nine from each participating institution. The respective government agencies provide the students with an adequate stipend to cover travel and living expenses for six months of study. The project has been running on target and the results of the first year of exchange have been more than impressive. This presentation will be a joint effort by the faculty and a number of participating students to demonstrate the cultural, agricultural, pedagogic, and practical lessons that have been learnt from this exchange in the field of organic farming. It will also highlight some of the challenges which need to be overcome in our efforts towards shaping sustainable agricultural and food systems which are cognizant of our respective environments

    Antibody Response After Third Vaccination With mRNA-1273 or BNT162b2: Extension of a Randomized Controlled SARS-CoV-2 Noninferiority Vaccine Trial in Patients With Different Levels of Immunosuppression (COVERALL-2).

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    Extension of the COVERALL (COrona VaccinE tRiAL pLatform) randomized trial showed noninferiority in antibody response of the third dose of Moderna mRNA-1273 vaccine (95.3% [95% confidence interval {CI}, 91.9%-98.7%]) compared to Pfizer-BioNTech BNT162b2 vaccine (98.1% [95% CI, 95.9%-100.0%]) in individuals with different levels of immunosuppression (difference, -2.8% [95% CI, -6.8% to 1.3%])

    Antibody Response After the Third SARS-CoV-2 Vaccine in Solid Organ Transplant Recipients and People Living With HIV (COVERALL-2).

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    BACKGROUND After basic immunization with 2 mRNA SARS-CoV-2 vaccine doses, only a small proportion of patients who are severely immunocompromised generate a sufficient antibody response. Hence, we assessed the additional benefit of a third SARS-CoV-2 vaccine in patients with different levels of immunosuppression. METHODS In this observational extension of the COVERALL trial (Corona Vaccine Trial Platform), we recruited patients from the Swiss HIV Cohort Study and the Swiss Transplant Cohort Study (ie, lung and kidney transplant recipients). We collected blood samples before and 8 weeks after the third SARS-CoV-2 vaccination with either mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech). The primary outcome was the proportion of participants showing an antibody response (Elecsys Anti-SARS-CoV-2 S test; threshold ≥100 U/mL) 8 weeks after the third SARS-CoV-2 vaccination. We also compared the proportion of patients who reached the primary outcome from basic immunization (the first and second vaccines) to the third vaccination. RESULTS Nearly all participants (97.2% [95% CI, 95.9%-98.6%], 564/580) had an antibody response. This response was comparable between mRNA-1273 (96.1% [95% CI, 93.7%-98.6%], 245/255) and BNT162b2 (98.2% [95% CI, 96.7%-99.6%], 319/325). Stratification by cohort showed that 99.8% (502/503) of people living with HIV and 80.5% (62/77) of recipients of solid organ transplants achieved the primary endpoint. The proportion of patients with an antibody response in solid organ transplant recipients improved from the second vaccination (22.7%, 15/66) to the third (80.5%, 62/77). CONCLUSIONS People living with HIV had a high antibody response. The third vaccine increased the proportion of solid organ transplant recipients with an antibody response. Clinical Trials Registration. NCT04805125 (ClinicalTrials.gov)

    Antibody Response After Third Vaccination With mRNA-1273 or BNT162b2: Extension of a Randomized Controlled SARS-CoV-2 Noninferiority Vaccine Trial in Patients With Different Levels of Immunosuppression (COVERALL-2)

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    Extension of the COVERALL (COrona VaccinE tRiAL pLatform) randomized trial showed noninferiority in antibody response of the third dose of Moderna mRNA-1273 vaccine (95.3% [95% confidence interval {CI}, 91.9%-98.7%]) compared to Pfizer-BioNTech BNT162b2 vaccine (98.1% [95% CI, 95.9%-100.0%]) in individuals with different levels of immunosuppression (difference, -2.8% [95% CI, -6.8% to 1.3%])

    Antibody Response After the Third SARS-CoV-2 Vaccine in Solid Organ Transplant Recipients and People Living With HIV (COVERALL-2)

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    BACKGROUND After basic immunization with 2 mRNA SARS-CoV-2 vaccine doses, only a small proportion of patients who are severely immunocompromised generate a sufficient antibody response. Hence, we assessed the additional benefit of a third SARS-CoV-2 vaccine in patients with different levels of immunosuppression. METHODS In this observational extension of the COVERALL trial (Corona Vaccine Trial Platform), we recruited patients from the Swiss HIV Cohort Study and the Swiss Transplant Cohort Study (ie, lung and kidney transplant recipients). We collected blood samples before and 8 weeks after the third SARS-CoV-2 vaccination with either mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech). The primary outcome was the proportion of participants showing an antibody response (Elecsys Anti-SARS-CoV-2 S test; threshold ≥100 U/mL) 8 weeks after the third SARS-CoV-2 vaccination. We also compared the proportion of patients who reached the primary outcome from basic immunization (the first and second vaccines) to the third vaccination. RESULTS Nearly all participants (97.2% [95% CI, 95.9%-98.6%], 564/580) had an antibody response. This response was comparable between mRNA-1273 (96.1% [95% CI, 93.7%-98.6%], 245/255) and BNT162b2 (98.2% [95% CI, 96.7%-99.6%], 319/325). Stratification by cohort showed that 99.8% (502/503) of people living with HIV and 80.5% (62/77) of recipients of solid organ transplants achieved the primary endpoint. The proportion of patients with an antibody response in solid organ transplant recipients improved from the second vaccination (22.7%, 15/66) to the third (80.5%, 62/77). CONCLUSIONS People living with HIV had a high antibody response. The third vaccine increased the proportion of solid organ transplant recipients with an antibody response. Clinical Trials Registration. NCT04805125 (ClinicalTrials.gov)

    Nonregistration, discontinuation, and nonpublication of randomized trials: A repeated metaresearch analysis

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    BACKGROUND We previously found that 25% of 1,017 randomized clinical trials (RCTs) approved between 2000 and 2003 were discontinued prematurely, and 44% remained unpublished at a median of 12 years follow-up. We aimed to assess a decade later (1) whether rates of completion and publication have increased; (2) the extent to which nonpublished RCTs can be identified in trial registries; and (3) the association between reporting quality of protocols and premature discontinuation or nonpublication of RCTs. METHODS AND FINDINGS We included 326 RCT protocols approved in 2012 by research ethics committees in Switzerland, the United Kingdom, Germany, and Canada in this metaresearch study. Pilot, feasibility, and phase 1 studies were excluded. We extracted trial characteristics from each study protocol and systematically searched for corresponding trial registration (if not reported in the protocol) and full text publications until February 2022. For trial registrations, we searched the (i) World Health Organization: International Clinical Trial Registry Platform (ICTRP); (ii) US National Library of Medicine (ClinicalTrials.gov); (iii) European Union Drug Regulating Authorities Clinical Trials Database (EUCTR); (iv) ISRCTN registry; and (v) Google. For full text publications, we searched PubMed, Google Scholar, and Scopus. We recorded whether RCTs were registered, discontinued (including reason for discontinuation), and published. The reporting quality of RCT protocols was assessed with the 33-item SPIRIT checklist. We used multivariable logistic regression to examine the association between the independent variables protocol reporting quality, planned sample size, type of control (placebo versus other), reporting of any recruitment projection, single-center versus multicenter trials, and industry versus investigator sponsoring, with the 2 dependent variables: (1) publication of RCT results; and (2) trial discontinuation due to poor recruitment. Of the 326 included trials, 19 (6%) were unregistered. Ninety-eight trials (30%) were discontinued prematurely, most often due to poor recruitment (37%; 36/98). One in 5 trials (21%; 70/326) remained unpublished at 10 years follow-up, and 21% of unpublished trials (15/70) were unregistered. Twenty-three of 147 investigator-sponsored trials (16%) reported their results in a trial registry in contrast to 150 of 179 industry-sponsored trials (84%). The median proportion of reported SPIRIT items in included RCT protocols was 69% (interquartile range 61% to 77%). We found no variables associated with trial discontinuation; however, lower reporting quality of trial protocols was associated with nonpublication (odds ratio, 0.71 for each 10% increment in the proportion of SPIRIT items met; 95% confidence interval, 0.55 to 0.92; p = 0.009). Study limitations include that the moderate sample size may have limited the ability of our regression models to identify significant associations. CONCLUSIONS We have observed that rates of premature trial discontinuation have not changed in the past decade. Nonpublication of RCTs has declined but remains common; 21% of unpublished trials could not be identified in registries. Only 16% of investigator-sponsored trials reported results in a trial registry. Higher reporting quality of RCT protocols was associated with publication of results. Further efforts from all stakeholders are needed to improve efficiency and transparency of clinical research

    Down-regulation of the myo-inositol oxygenase gene family has no effect on cell wall composition in Arabidopsis

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    The enzyme myo-inositol oxygenase (MIOX; E.C. 1.13.99.1) catalyzes the ring-opening four-electron oxidation of myo-inositol into glucuronic acid, which is subsequently activated to UDP-glucuronic acid (UDP-GlcA) and serves as a precursor for plant cell wall polysaccharides. Starting from single T-DNA insertion lines in different MIOX-genes a quadruple knockdown (miox1/2/4/5-mutant) was obtained by crossing, which exhibits greater than 90% down-regulation of all four functional MIOX genes. Miox1/2/4/5-mutant shows no visible phenotype and produces viable pollen. The alternative pathway to UDP-glucuronic acid via UDP-glucose is upregulated in the miox1/2/4/5-mutant as a compensatory mechanism. Miox1/2/4/5-mutant is impaired in the utilization of myo-inositol for seedling growth. The incorporation of myo-inositol derived sugars into cell walls is strongly (>90%) inhibited. Instead, myo-inositol and metabolites produced from myo-inositol such as galactinol accumulate in the miox1/2/4/5-mutant. The increase in galactinol and raffinose family oligosaccharides does not enhance stress tolerance. The ascorbic acid levels are the same in mutant and wild type plants
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