975 research outputs found

    Accelerating vaccine development and deployment: report of a Royal Society satellite meeting.

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    The Royal Society convened a meeting on the 17th and 18th November 2010 to review the current ways in which vaccines are developed and deployed, and to make recommendations as to how each of these processes might be accelerated. The meeting brought together academics, industry representatives, research sponsors, regulators, government advisors and representatives of international public health agencies from a broad geographical background. Discussions were held under Chatham House rules. High-throughput screening of new vaccine antigens and candidates was seen as a driving force for vaccine discovery. Multi-stakeholder, small-scale manufacturing facilities capable of rapid production of clinical grade vaccines are currently too few and need to be expanded. In both the human and veterinary areas, there is a need for tiered regulatory standards, differentially tailored for experimental and commercial vaccines, to allow accelerated vaccine efficacy testing. Improved cross-fertilization of knowledge between industry and academia, and between human and veterinary vaccine developers, could lead to more rapid application of promising approaches and technologies to new product development. Identification of best-practices and development of checklists for product development plans and implementation programmes were seen as low-cost opportunities to shorten the timeline for vaccine progression from the laboratory bench to the people who need it

    Potential research participants’ use of information during the consent process : a qualitative pilot study of patients enrolled in a clinical trial

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    There is increasing evidence that clinical trial participants are uninformed about the trials in which they participate, raising ethical concerns regarding informed consent. The aim of this pilot study was to explore clinical trial participants’ use of consent discussions and information sheets when considering participating in clinical trials research. A qualitative, interview-based pilot study was designed in order to elicit, through dialogue, details of the reasons for participants’ use of, and preferences regarding, different modes of information provision. Semi-structured interviews were undertaken with two different groups of patients who were participants in the Reinforcement of Closure of Stoma Site trial. The first group comprised newly-consented trial participants, who had been recruited up to 72 hours before our interview; the second group comprised patients attending a follow-up clinic 12 months after joining the trial. Thirteen participants were recruited in total: three newly-consented patients, and ten follow-up patients. The study found that participants’ use of consent discussions to gain information about clinical trials was varied, and that they only minimally used information sheets after providing initial consent for the trial. Participants demonstrated varying degrees of knowledge about the trial, with some having forgotten that they were still involved in the trial. Participants reported a high level of trust in medical staff as a reason for not seeking more information about the trial. Some participants reported dissatisfaction with the timing of information provision. Some were amenable to novel ways of receiving trial information, such as web-based methods. The pilot study demonstrated the feasibility of a larger study into the provision of information to prospective clinical trial participants. The results suggest that considering alternative ways of providing information and the appropriateness of existing information provision may be acceptable to and useful for potential trial participants

    Change Point Problem for Censored Data

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    Department of Probability and Mathematical StatisticsKatedra pravděpodobnosti a matematické statistikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

    The challenges of Plasmodium vivax human malaria infection models for vaccine development

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    Controlled Human Malaria Infection models (CHMI) have been critical to advancing new vaccines for malaria. Stringent and safe preparation of a challenge agent is key to the success of any CHMI. Difficulty producing the Plasmodium vivax parasite in vitro has limited production of qualified parasites for CHMI as well as the functional assays required to screen and down-select candidate vaccines for this globally distributed parasite. This and other challenges to P. vivax CHMI (PvCHMI), including scientific, logistical, and ethical obstacles, are common to P. vivax research conducted in both non-endemic and endemic countries, with additional hurdles unique to each. The challenges of using CHMI for P. vivax vaccine development and evaluation, lessons learned from previous and ongoing clinical trials, and the way forward to effectively perform PvCHMI to support vaccine development, are discussed

    Naturally-acquired and vaccine-induced human monoclonal antibodies to plasmodium vivax Duffy binding protein inhibit invasion of Plasmodium knowlesi (pvdbpor) transgenic parasites

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    The Duffy antigen receptor for chemokines (DARC) expressed on erythrocytes is central to Plasmodium vivax (Pv) invasion of reticulocytes. Pv expresses a Duffy binding protein (PvDBP) on merozoites, a DARC ligand, and their protein-protein interaction is central to vivax blood stage malaria. Here we compared the functional activity of humAbs derived from naturally exposed and vaccinated individuals for the first time using easily cultured P. knowlesi (Pk) that had been genetically modified to replace its endogenous PkDBP orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. This transgenic parasite requires DARC to invade human erythrocytes but is not reticulocyte restricted. Using this model, we evaluated the invasion inhibition potential of 12 humAbs (9 naturally acquired; 3 vaccine-induced) targeting PvDBP individually and in combinations using growth inhibition assays (GIAs). The PvDBP-specific humAbs demonstrated 70-100% inhibition of PkPvDBPOR invasion with the IC50 values ranging from 51 to 338 ÎĽg/mL for the 9 naturally acquired (NA) humAbs and 33 to 99 ÎĽg/ml for the 3 vaccine-induced (VI) humAbs. To evaluate antagonistic, additive, or synergistic effects, six pairwise combinations were performed using select humAbs. Of these combinations tested, one NA/NA (099100/094083) combination demonstrated relatively strong additive inhibition between 10-100 ÎĽg/mL; all combinations of NA and VI humAbs showed additive inhibition at concentrations below 25 ÎĽg/mL and antagonism at higher concentrations. None of the humAb combinations showed synergy. This PkPvDBPOR model system enables efficient assessment of NA and VI humAbs individually and in combination

    Oxygen Recovery Kinetics in the Forearm Flexors of Multiple Ability Groups of Rock Climbers

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    Fryer, SM, Stoner, L, Dickson, TG, Draper, SB, McCluskey, MJ, Hughes, JD, How, SC, and Draper, N. Oxygen recovery kinetics in the forearm flexors of multiple ability groups of rock climbers. J Strength Cond Res 29(6): 1633-1639, 2015-The purpose of this study was to determine muscle tissue oxidative capacity and recovery in intermediate, advanced, and elite rock climbers. Forty-four male participants performed (a) sustained and (b) intermittent contractions at 40% of maximal volitional contraction (MVC) on a sport-specific fingerboard until volitional fatigue. Near-infrared spectroscopy was used to assess muscle tissue oxygenation during both the exercise and the 5-minutes passive recovery period, in the flexor digitorum profundus (FDP) and flexor carpi radialis (FCR). During the sustained contraction only, muscle tissue deoxygenation (O2 debt) in the FDP and FCR was significantly greater in elite climbers compared with the control, intermediate, and advanced groups (FDP: 32 vs. 15, 19, 22%; FCR: 19 vs. 11, 8, 15%, respectively). However, elite climbers had a significantly quicker time to half recovery (T1/2) than the control and intermediate groups in the FDP (8 vs. 95 and 47 seconds, respectively) and the FCR (7 vs. 30 and 97 seconds, respectively) because the O2% recovered per second being significantly greater (FDP: 4.2 vs. 0.7 and 0.3; FCR: 4.8 vs. 0.1 and 0.2, respectively). Furthermore, during the intermittent contraction, T1/2 in elite climbers was significantly quicker compared with the control and intermediate groups in the FDP (8 vs. 93 and 83 seconds, respectively) and FCR (16 vs. 76 and 50 seconds, respectively). Consequently, lower-level climbers should focus training on specific intermittent fatigue protocols. Competition or elite climbers should make use of appropriate rests on route to aid recovery and increase the chances of reaching the next hold

    Nucleon Axial Form Factor from Lattice QCD

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    Results for the isovector axial form factors of the proton from a lattice QCD calculation are presented for both point-split and local currents. They are obtained on a quenched 163×2416^{3} \times 24 lattice at β=6.0\beta= 6.0 with Wilson fermions for a range of quark masses from strange to charm. We determine the finite lattice renormalization for both the local and point-split currents of heavy quarks. Results extrapolated to the chiral limit show that the q2q^2 dependence of the axial form factor agrees reasonably well with experiment. The axial coupling constant gAg_A calculated for the local and the point-split currents is about 6\% and 12\% smaller than the experimental value respectively.Comment: 8 pages, 5 figures (included in part 2), UK/93-0

    Human basigin (CD147) does not directly interact with SARS-CoV-2 spike glycoprotein

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    Basigin, or CD147, has been reported as a co-receptor used by SARS-CoV-2 to invade host cells. Basigin also has a well-established role in Plasmodium falciparum malaria infection of human erythrocytes where it is bound by one of the parasite’s invasion ligands, reticulocyte binding protein homolog 5 (RH5). Here, we sought to validate the claim that the receptor binding domain (RBD) of SARS-CoV-2 spike glycoprotein can form a complex with basigin, using RH5-basigin as a positive control. Using recombinantly expressed proteins, size exclusion chromatography and surface plasmon resonance, we show that neither RBD nor full-length spike glycoprotein bind to recombinant human basigin (either expressed in E. coli or mammalian cells). Given the immense interest in SARS-CoV-2 therapeutic targets, we would caution the inclusion of basigin in this list on the basis of its reported direct interaction with SARS-CoV-2 spike glycoprotein. Importance Reducing the mortality and morbidity associated with COVID-19 remains a global health priority. Critical to these efforts is the identification of host factors that are essential to viral entry and replication. Basigin, or CD147, was previously identified as a possible therapeutic target based on the observation that it may act as a co-receptor for SARS-COV-2, binding to the receptor binding domain of the spike protein. Here, we show that there is no direct interaction between the RBD and basigin, casting doubt on its role as a co-receptor and plausibility as a therapeutic target

    Multiplication and Growth Inhibition Activity Assays for the Zoonotic Malaria Parasite, Plasmodium knowlesi.

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    Malaria remains a major cause of morbidity and mortality globally. Clinical symptoms of the disease arise from the growth and multiplication of Plasmodium parasites within the blood of the host. Thus in vitro assays to determine how drug, antibody and genetic perturbations affect the growth rate of Plasmodium parasites are essential for the development of new therapeutics and improving our understanding of parasite biology. As both P. falciparum and P. knowlesi can be maintained in culture with human red blood cells, the effect of antimalarial drugs and inhibitory antibodies that target the invasion capacity of Plasmodium parasites are routinely investigated by using multiplication assays or growth inhibition assays against these two species. This protocol gives detailed step-by-step procedures to carry out flow cytometry-based multiplication assays and growth inhibition activity assays to test neutralizing antibodies based on the activity of the parasite enzyme lactate dehydrogenase of Plasmodium knowlesi adapted to human red blood cell culture. Whilst similar assays are well established for P. falciparum, P. knowlesi is more closely related to all other human infective species ( Pacheco et al., 2018 ) and so can be used as a surrogate for testing drugs and vaccines for other malaria species such as P. vivax, which is the most widespread cause of malaria outside of Africa, but cannot yet be cultured under laboratory conditions
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