243 research outputs found

    Paradigm shift in the diagnosis of peste des petits ruminants: scoping review

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    Peste des petits ruminants virus causes a highly contagious disease, which poses enormous economic losses in domestic animals and threatens the conservation of wild herbivores. Diagnosis remains a cornerstone to the Peste des petits ruminants Global Control and Eradication Strategy, an initiative of the World Organisation for Animal Health and the Food and Agriculture Organisation. The present review presents the peste des petits ruminants diagnostic landscape, including the practicality of commercially available diagnostic tools, prototype tests and opportunities for new technologies. The most common peste des petits ruminants diagnostic tools include; agar gel immunodiffusion, counter-immunoelectrophoresis, enzyme-linked immunosorbent assays, reverse transcription polymerase chain reaction either gel-based or real-time, reverse transcription loop-mediated isothermal amplification, reverse transcription recombinase polymerase amplification assays, immunochromatographic lateral flow devices, luciferase immunoprecipitation system and pseudotype-based assays. These tests vary in their technical demands, but all require a laboratory with exception of immunochromatographic lateral flow and possibly reverse transcription loop-mediated isothermal amplification and reverse transcription recombinase polymerase amplification assays. Thus, we are proposing an efficient integration of diagnostic tests for rapid and correct identification of peste des petits ruminants in endemic zones and to rapidly confirm outbreaks. Deployment of pen-side tests will improve diagnostic capacity in extremely remote settings and susceptible wildlife ecosystems, where transportation of clinical samples in the optimum cold chain is unreliable

    <i>Mare Geneticum</i>: balancing governance of marine genetic resources in international waters

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    A fair and effective regime regulating benefit-sharing of marine genetic resources (MGR) in areas beyond national jurisdiction (ABNJ) must consider the inclusion of developing states, support scientific research and safeguard investments of the private sector. The present innovative proposal ensures a delicate balance through an approach based on open access, albeit with limitations. Access to MGR in ABNJ is facilitated, but conditional on the public release of collected samples and raw data. Adoption of the open access principle guarantees a powerful form of non-monetary benefit-sharing. The balance is maintained by the option for an extended embargo period, allowing samples and data to be kept confidential for a certain period, against payment to a biodiversity contribution fund. Monetary benefit-sharing, as a sector-negotiated percentage on revenue, could be imposed at the point of product commercialisation, and would offer a tangible payment system with a low transaction cost

    Usefulness of serum HE4 in endometriotic cysts

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    Usefulness of serum HE4 in endometriotic cyst

    Structural basis for the high specificity of a Trypanosoma congolense immunoassay targeting glycosomal aldolase

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    Background : Animal African trypanosomosis (AAT) is a neglected tropical disease which imposes a heavy burden on the livestock industry in Sub-Saharan Africa. Its causative agents are Trypanosoma parasites, with T. congolense and T. vivax being responsible for the majority of the cases. Recently, we identified a Nanobody (Nb474) that was employed to develop a homologous sandwich ELISA targeting T. congolense fructose-1,6-bisphosphate aldolase (TcoALD). Despite the high sequence identity between trypanosomatid aldolases, the Nb474-based immunoassay is highly specific for T. congolense detection. The results presented in this paper yield insights into the molecular principles underlying the assay's high specificity. Methodology/Principal findings : The structure of the Nb474-TcoALD complex was determined via X-ray crystallography. Together with analytical gel filtration, the structure reveals that a single TcoALD tetramer contains four binding sites for Nb474. Through a comparison with the crystal structures of two other trypanosomatid aldolases, TcoALD residues Ala77 and Leu106 were identified as hot spots for specificity. Via ELISA and surface plasmon resonance (SPR), we demonstrate that mutation of these residues does not abolish TcoALD recognition by Nb474, but does lead to a lack of detection in the Nb474-based homologous sandwich immunoassay. Conclusions/Significance : The results show that the high specificity of the Nb474-based immunoassay is not determined by the initial recognition event between Nb474 and TcoALD, but rather by its homologous sandwich design. This (i) provides insights into the optimal set-up of the assay, (ii) may be of great significance for field applications as it could explain the potential detection escape of certain T. congolense strains, and (iii) may be of general interest to those developing similar assays

    Exploiting nanobodies and Affimers for superresolution imaging in light microscopy

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    Antibodies have long been the main approach used for localizing proteins of interest by light microscopy. In the past 5 yr or so, and with the advent of superresolution microscopy, the diversity of tools for imaging has rapidly expanded. One main area of expansion has been in the area of nanobodies, small single-chain antibodies from camelids or sharks. The other has been the use of artificial scaffold proteins, including Affimers. The small size of nanobodies and Affimers compared with the traditional antibody provides several advantages for superresolution imaging

    Soluble aggregates present in cerebrospinal fluid change in size and mechanism of toxicity during Alzheimer’s disease progression

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    Abstract: Soluble aggregates of amyloid-β (Aβ) have been associated with neuronal and synaptic loss in Alzheimer’s disease (AD). However, despite significant recent progress, the mechanisms by which these aggregated species contribute to disease progression are not fully determined. As the analysis of human cerebrospinal fluid (CSF) provides an accessible window into the molecular changes associated with the disease progression, we characterised soluble aggregates present in CSF samples from individuals with AD, mild cognitive impairment (MCI) and healthy controls using a range of sensitive biophysical methods. We used super-resolution imaging and atomic force microscopy to characterise the size and structure of the aggregates present in CSF and correlate this with their ability to permeabilise lipid membranes and induce an inflammatory response. We found that these aggregates are extremely heterogeneous and exist in a range of sizes, varying both structurally and in their mechanisms of toxicity during the disease progression. A higher proportion of small aggregates of Aβ that can cause membrane permeabilization are found in MCI CSF; in established AD, a higher proportion of the aggregates were larger and more prone to elicit a pro-inflammatory response in glial cells, while there was no detectable change in aggregate concentration. These results show that large aggregates, some longer than 100 nm, are present in the CSF of AD patients and suggest that different neurotoxic mechanisms are prevalent at different stages of AD

    The state of professionalisation of midwifery in Belgium: A discussion paper.

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    AIM: To describe the state of the professionalisation of midwifery in Belgium, and to formulate recommendations for advancing the midwifery profession. METHODS: A descriptive overview of maternity care in Belgium and the professionalisation of midwifery through an analysis of relevant policy and academic texts, underpinned by Greenwood's sociological criteria for a profession: (1) own body of knowledge, (2) recognised authority, (3) broader community sanctions, (4) own code of ethics and (5) professional culture sustained by formal professional associations. From these insights, recommendations for advancing the midwifery profession in Belgium are formulated. FINDINGS: Current strengths of the professionalisation of midwifery in Belgium included unified midwifery education programmes, progress in midwifery research and overarching national documents for guiding midwifery education, practice and regulation. In contrast however challenges, such as the limited recognition of midwives' roles by its clientele, limitations of midwives' competencies and autonomy, lacking development of advanced roles in maternity care practice and a lack of unity of the organisation and its members, were also identified. Based on these, recommendations are made to strengthen Belgian midwifery. CONCLUSIONS: Recommendations for advancing the midwifery profession in Belgium includes in particular increasing public awareness of midwives' roles and competencies, implementing the full scope of midwifery practice and monitoring and advancing this practice. Thus, professional autonomy over both midwifery practice and working conditions should be enhanced. United midwifery organisations, together with women's groups, other maternity care professionals and policy-makers as equal partners are key to bring about changes in the Belgian maternity care landscape

    The development and optimisation of Nanobody based electrochemical immunosensors for IgG

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    Biosensors are increasingly heralded for their potential to create inexpensive diagnostic devices which are sensitive, selective and easy to use. One of the key categories of biosensor are immunosensors, which have historically used antibodies as bioreceptors. Though widely used, antibodies bring inherent limitations such as variability, limited stability and their reliance on animal sources. This has led to the development of alternative immuno-reagents such as non-antibody binding proteins (NABPs). These are low molecular weight proteins which largely avoid the aforementioned advantages of antibodies. They are commonly produced by bacteria enabling the use of DNA technology to manipulate bioreceptors at the molecular level. Single chain VHHs (commonly known as nanobodies) are an antibody derived NABP adapted from camelid heavy chain antibodies which are the isolated binding domain. Whilst nanobodies have been used for diagnostic and therapeutic applications, they have limited demonstration in biosensors. In this study, both antibodies and nanobodies were used to construct a biosensor. In addition nanobody performance was optimised by introducing a novel peptide spacer. The role of nanobody orientation and spacing was thus investigated and spacer length was optimised, leading to an increase in the sensitivity of the biosensor
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