78 research outputs found

    Laterally Orienting C. elegans Using Geometry at Microscale for High-Throughput Visual Screens in Neurodegeneration and Neuronal Development Studies

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    C. elegans is an excellent model system for studying neuroscience using genetics because of its relatively simple nervous system, sequenced genome, and the availability of a large number of transgenic and mutant strains. Recently, microfluidic devices have been used for high-throughput genetic screens, replacing traditional methods of manually handling C. elegans. However, the orientation of nematodes within microfluidic devices is random and often not conducive to inspection, hindering visual analysis and overall throughput. In addition, while previous studies have utilized methods to bias head and tail orientation, none of the existing techniques allow for orientation along the dorso-ventral body axis. Here, we present the design of a simple and robust method for passively orienting worms into lateral body positions in microfluidic devices to facilitate inspection of morphological features with specific dorso-ventral alignments. Using this technique, we can position animals into lateral orientations with up to 84% efficiency, compared to 21% using existing methods. We isolated six mutants with neuronal development or neurodegenerative defects, showing that our technology can be used for on-chip analysis and high-throughput visual screens

    Relationship between the morphology of the foveal avascular zone, retinal structure, and macular circulation in patients with diabetes mellitus

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    Diabetic Retinopathy (DR) is an extremely severe and common degenerative disease. The purpose of this study was to quantify the relationship between various parameters including the Foveal Avascular Zone (FAZ) morphology, retinal layer thickness, and retinal hemodynamic properties in healthy controls and patients with diabetes mellitus (DM) with and with no mild DR (MDR) using Spectral-Domain Optical Coherence Tomography (Spectralis SDOCT, Heidelberg Engineering GmbH, Germany) and the Retinal Function Imager (Optical Imaging, Ltd., Rehovot, Israel). Our results showed a higher FAZ area and diameter in MDR patients. Blood flow analysis also showed that there is a significantly smaller venous blood flow velocity in MDR patients. Also, a significant difference in roundness was observed between DM and MDR groups supporting the development of asymmetrical FAZ expansion with worsening DR. Our results suggest a potential anisotropy in the mechanical properties of the diabetic retina with no retinopathy that may trigger the FAZ elongation in a preferred direction resulting in either thinning or thickening of intraretinal layers in the inner and outer segments of the retina as a result of autoregulation. A detailed understanding of these relationships may facilitate earlier detection of DR, allowing for preservation of vision and better clinical outcomes

    Prothymosin alpha: a ubiquitous polypeptide with potential use in cancer diagnosis and therapy

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    The thymus is a central lymphoid organ with crucial role in generating T cells and maintaining homeostasis of the immune system. More than 30 peptides, initially referred to as “thymic hormones,” are produced by this gland. Although the majority of them have not been proven to be thymus-speciWc, thymic peptides comprise an eVective group of regulators, mediating important immune functions. Thymosin fraction Wve (TFV) was the Wrst thymic extract shown to stimulate lymphocyte proliferation and diVerentiation. Subsequent fractionation of TFV led to the isolation and characterization of a series of immunoactive peptides/polypeptides, members of the thymosin family. Extensive research on prothymosin (proT) and thymosin 1 (T1) showed that they are of clinical signiWcance and potential medical use. They may serve as molecular markers for cancer prognosis and/or as therapeutic agents for treating immunodeWciencies, autoimmune diseases and malignancies. Although the molecular mechanisms underlying their eVect are yet not fully elucidated proT and T1 could be considered as candidates for cancer immunotherapy. In this review, we will focus in principle on the eventual clinical utility of proT, both as a tumor biomarker and in triggering anticancer immune responses. Considering the experience acquired via the use of T1 to treat cancer patients, we will also discuss potential approaches for the future introduction of proT into the clinical setting

    The V471A polymorphism in autophagy-related gene ATG7 modifies age at onset specifically in Italian Huntington disease patients

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    The cause of Huntington disease (HD) is a polyglutamine repeat expansion of more than 36 units in the huntingtin protein, which is inversely correlated with the age at onset of the disease. However, additional genetic factors are believed to modify the course and the age at onset of HD. Recently, we identified the V471A polymorphism in the autophagy-related gene ATG7, a key component of the autophagy pathway that plays an important role in HD pathogenesis, to be associated with the age at onset in a large group of European Huntington disease patients. To confirm this association in a second independent patient cohort, we analysed the ATG7 V471A polymorphism in additional 1,464 European HD patients of the “REGISTRY” cohort from the European Huntington Disease Network (EHDN). In the entire REGISTRY cohort we could not confirm a modifying effect of the ATG7 V471A polymorphism. However, analysing a modifying effect of ATG7 in these REGISTRY patients and in patients of our previous HD cohort according to their ethnic origin, we identified a significant effect of the ATG7 V471A polymorphism on the HD age at onset only in the Italian population (327 patients). In these Italian patients, the polymorphism is associated with a 6-years earlier disease onset and thus seems to have an aggravating effect. We could specify the role of ATG7 as a genetic modifier for HD particularly in the Italian population. This result affirms the modifying influence of the autophagic pathway on the course of HD, but also suggests population-specific modifying mechanisms in HD pathogenesis

    A large animal model for a failed two-stage revision of intramedullary nail-related infection by methicillin-resistant Staphylococcus aureus

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    The treatment of chronic orthopaedic device-associated infection (ODRI) often requires multiple surgeries and prolonged antibiotic therapy. Despite this extensive treatment protocol, the procedure is associated with significant failure rates. Currently, no large animal model is available that recapitulates a failed revision. Therefore, our aim was to establish a large animal model for failed treatment of an ODRI in order to serve as a testbed for future interventional strategies. Adult Swiss Alpine sheep received an intramedullary nail in the tibia and a localised inoculum of either a methicillin-sensitive or methicillin-resistant Staphylococcus aureus (MSSA, MRSA respectively). After 8 weeks, when chronic infection had been established, the animals underwent a staged revision with debridement and temporary placement of an antibiotic-loaded cement spacer. Antibiotics were delivered systemically in a standard or pathogen-adapted manner. Debridement and implant exchange alone failed to treat the MSSA infection. Neither local therapy alone nor systemic therapy alone were effective in resolving infection with MSSA, but a combination of local and systemic therapy was effective against it. MRSA infection was not resolved by the combination of local and systemic antibiotics (standard or pathogen-adapted). A model for failed revision of MRSA infection is described despite the use of local and systemic antibiotics. Novel interventions may be assessed using this model, including antibiotic and non-antibiotic interventions

    A large animal model for a failed two-stage revision of intramedullary nail-related infection by methicillin-resistant Staphylococcus aureus

    No full text
    The treatment of chronic orthopaedic device-associated infection (ODRI) often requires multiple surgeries and prolonged antibiotic therapy. Despite this extensive treatment protocol, the procedure is associated with significant failure rates. Currently, no large animal model is available that recapitulates a failed revision. Therefore, our aim was to establish a large animal model for failed treatment of an ODRI in order to serve as a testbed for future interventional strategies. Adult Swiss Alpine sheep received an intramedullary nail in the tibia and a localised inoculum of either a methicillin-sensitive or methicillin-resistant Staphylococcus aureus (MSSA, MRSA respectively). After 8 weeks, when chronic infection had been established, the animals underwent a staged revision with debridement and temporary placement of an antibiotic-loaded cement spacer. Antibiotics were delivered systemically in a standard or pathogen-adapted manner. Debridement and implant exchange alone failed to treat the MSSA infection. Neither local therapy alone nor systemic therapy alone were effective in resolving infection with MSSA, but a combination of local and systemic therapy was effective against it. MRSA infection was not resolved by the combination of local and systemic antibiotics (standard or pathogen-adapted). A model for failed revision of MRSA infection is described despite the use of local and systemic antibiotics. Novel interventions may be assessed using this model, including antibiotic and non-antibiotic interventions

    Genetic Isolation of Hypothalamic Neurons that Regulate Context-Specific Male Social Behavior.

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    Nearly all animals engage in a complex assortment of social behaviors that are essential for the survival of the species. In mammals, these behaviors are regulated by sub-nuclei within the hypothalamus, but the specific cell types within these nuclei responsible for coordinating behavior in distinct contexts are only beginning to be resolved. Here, we identify a population of neurons in the ventral premammillary nucleus of the hypothalamus (PMV) that are strongly activated in male intruder mice in response to a larger resident male but that are not responsive to females. Using a combination of molecular and genetic approaches, we demonstrate that these PMV neurons regulate intruder-specific male social behavior and social novelty recognition in a manner dependent on synaptic release of the excitatory neurotransmitter glutamate. These data provide direct evidence for a unique population of neurons that regulate social behaviors in specific contexts

    Extending group technology to the identification and the analysis of enterprises networks

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    This paper proposes a practical tool for the identification and analysis of industrial networks among a set of enterprises already linked by trade relationships. The methodology extends the group technology (GT) and the production flow analysis (PFA) approach, widely applied in organising the production inside industrial plants. The main advantage of this approach is the small set of data needed to get a feasible solution. An heuristic procedure, sketched at several degrees of analysis, allows not only the identification of the industrial network, but also, with the contribution of other analytical and theoretical studies, the exploitation of potential or existing organisational structure. If properly supported by other studies covering remaining aspects (social, political) of industrial organisation, the tool could be practically useful in recognising possible improvements in the organisation of a given set of enterprises, or also could be used as an investigation instrument for public bodies in exploiting existing or hidden potential industrial network
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