274 research outputs found

    Characterization of HSP90 isoforms in transformed bovine leukocytes infected with Theileria annulata

    Get PDF
    HSP90 chaperones are essential regulators of cellular function, as they ensure the appropriate conformation of multiple key client proteins. Four HSP90 isoforms were identified in the protozoan parasite Theileria annulata. Partial characterisation was undertaken for three and localisation confirmed for cytoplasmic (TA12105); endoplasmic reticulum (TA06470) and apicoplast (TA10720) forms. ATPase activity and binding to the HSP90 inhibitor geldanamycin, were demonstrated for recombinant TA12105 and all three native forms could be isolated to varying extents by binding to geldanamycin beads. Because it is essential, HSP90 is considered a potential therapeutic drug target. Resistance to the only specific Theileriacidal drug is increasing and one challenge for design of drugs that target the parasite is to limit the effect on the host. An in vitro cell culture system that allows comparison between uninfected bovine cells and the T. annulata-infected counterpart was utilised to test the effects of geldanamycin and the derivative 17-AAG. T. annulata-infected cells had greater tolerance to geldanamycin than uninfected cells yet exhibited significantly more sensitivity to 17-AAG. These findings suggest that parasite HSP90 isoform (s) can alter the drug sensitivity of infected host cells and that members of the Theileria HSP90 family are potential targets worthy of further investigation

    Spatio-temporal Gaussian process models for extended and group object tracking with irregular shapes

    Get PDF
    Extended object tracking has become an integral part of many autonomous systems during the last two decades. For the first time, this paper presents a generic spatio-temporal Gaussian process (STGP) for tracking an irregular and non-rigid extended object. The complex shape is represented by key points and their parameters are estimated both in space and time. This is achieved by a factorization of the power spectral density function of the STGP covariance function. A new form of the temporal covariance kernel is derived with the theoretical expression of the filter likelihood function. Solutions to both the filtering and the smoothing problems are presented. A thorough evaluation of the performance in a simulated environment shows that the proposed STGP approach outperforms the state-of-the-art approach, with up to 90% improvement in the accuracy in position, 95% in velocity and 7% in the shape, while tracking a simulated asymmetric non-rigid object. The tracking performance improvement for a non-rigid irregular real object is up to 43% in position, 68% in velocity, 10% in the recall and 115% in the precision measures

    Structural heterogeneity in twinned Yb 2− x

    Full text link

    Not Hot, but Sharp: Dissociation of Pinprick and Heat Perception in Snake Eye Appearance Myelopathy

    Get PDF
    Following a traumatic spinal cord injury, a 53-year-old male developed a central cord syndrome with at-level neuropathic pain. Magnetic resonance imaging revealed a classical “snake eye” appearance myelopathy, with marked hyperintensities at C5-C7. Clinical examination revealed intact pinprick sensation coupled with lost or diminished thermal/heat sensation. This dissociation could be objectively confirmed through multi-modal neurophysiological assessments. Specifically, contact heat evoked potentials were lost at-level, while pinprick evoked potentials were preserved. This pattern corresponds with that seen after surgical commissural myelotomy. To our knowledge, this is the first time such a dissociation has been objectively documented, highlighting the diagnostic potential of multi-modal neurophysiological assessments. In future studies, a comprehensive assessment of different nociceptive modalities may help elucidate the pathophysiology of neuropathic pain

    MRI and CT imaging biomarkers of cerebral amyloid angiopathy in lobar intracerebral hemorrhage

    Get PDF
    BACKGROUND: Cerebral amyloid angiopathy (CAA), a common cause of intracerebral hemorrhage (ICH), is diagnosed using the Boston criteria including magnetic resonance imaging (MRI) biomarkers (cerebral microbleeds (CMBs) and cortical superficial siderosis (cSS). The simplified Edinburgh criteria include computed tomography (CT) biomarkers (subarachnoid extension (SAE) and finger-like projections (FLPs)). The underlying mechanisms and diagnostic accuracy of CT compared to MRI biomarkers of CAA are unknown. METHODS: We included 140 survivors of spontaneous lobar supratentorial ICH with both acute CT and MRI. We assessed associations between MRI and CT biomarkers and the diagnostic accuracy of CT- compared to MRI-based criteria. RESULTS: FLPs were more common in patients with strictly lobar CMB (44.7% vs 23.5%; p = 0.014) and SAE was more common in patients with cSS (61.3% vs 31.2%; p = 0.002). The high probability of the CAA category of the simplified Edinburgh criteria showed 87.2% (95% confidence interval (CI): 78.3-93.4) specificity, 29.6% (95% CI: 18.0-43.6) sensitivity, 59.3% (95% CI: 38.8-77.6) positive predictive value, and 66.4% (95%: CI 56.9-75.0) negative predictive value, 2.3 (95% CI: 1.2-4.6) positive likelihood ratio and 0.8 (95% CI 0.7-1.0) negative likelihood ratio for probable CAA (vs non-probable CAA), defined by the modified Boston criteria; the area under the receiver operating characteristic curve (AUROC) was 0.62 (95% CI: 0.54-0.71). CONCLUSION: In lobar ICH survivors, we found associations between putative biomarkers of parenchymal CAA (FLP and strictly lobar CMBs) and putative biomarkers of leptomeningeal CAA (SAE and cSS). In a hospital population, CT biomarkers might help rule-in probable CAA (diagnosed using the Boston criteria), but their absence is probably not as useful to rule it out, suggesting an important continued role for MRI in ICH survivors with suspected CAA

    Electronic structure of fluorides: general trends for ground and excited state properties

    Full text link
    The electronic structure of fluorite crystals are studied by means of density functional theory within the local density approximation for the exchange correlation energy. The ground-state electronic properties, which have been calculated for the cubic structures CaF2CaF_{2},SrF2SrF_{2}, BaF2BaF_{2}, CdF2CdF_{2}, HgF2HgF_{2}, β\beta -PbF2PbF_{2}, using a plane waves expansion of the wave functions, show good comparison with existing experimental data and previous theoretical results. The electronic density of states at the gap region for all the compounds and their energy-band structure have been calculated and compared with the existing data in the literature. General trends for the ground-state parameters, the electronic energy-bands and transition energies for all the fluorides considered are given and discussed in details. Moreover, for the first time results for HgF2HgF_{2} have been presented

    Cerebral Small Vessel Disease and Functional Outcome Prediction after Intracerebral Haemorrhage

    Get PDF
    OBJECTIVE: To determine whether CT-based cerebral small vessel disease (SVD) biomarkers are associated with 6-month functional outcome after intracerebral hemorrhage (ICH), and whether these biomarkers improve the performance of pre-existing ICH score. METHODS: We included 864 patients with acute ICH from a multicentre, hospital-based prospective cohort study. We evaluated CT-based SVD biomarkers (white matter hypodensities [WMH]; lacunes; brain atrophy; and a composite SVD burden score) and their associations with poor 6-month functional outcome (modified Rankin Scale [mRS] score >2). The area under the receiver operating characteristic curve (AUROC) and Hosmer-Lemeshow test were used to assess discrimination and calibration of the ICH score with and without SVD biomarkers. RESULTS: In multivariable models (adjusted for ICH score components), WMH presence (OR 1.52, 95%CI 1.12-2.06), cortical atrophy presence (OR 1.80, 95%CI 1.19-2.73), deep atrophy presence (OR 1.66, 95%CI 1.17-2.34), and severe atrophy (either deep or cortical) (OR 1.94, 95%CI 1.36-2.74) were independently associated with poor functional outcome. For the ICH score, the AUROC was 0.71 (95%CI 0.68-0.74). Adding SVD markers did not significantly improve ICH score discrimination; for the best model (adding severe atrophy) the AUROC was 0.73 (95%CI 0.69-0.76). These results were confirmed when considering lobar and non-lobar ICH, separately. CONCLUSIONS: The ICH score has acceptable discrimination for predicting 6-month functional outcome after ICH. CT biomarkers of SVD are associated with functional outcome but adding them does not significantly improve ICH score discrimination
    corecore