152 research outputs found
Peripheral Administration of the Soluble TNF Inhibitor XPro1595 Modifies Brain Immune Cell Profiles, Decreases Beta-Amyloid Plaque Load, and Rescues Impaired Long-Term Potentiation in 5xFAD Mice
Clinical and animal model studies have implicated inflammation and peripheral immune cell responses in the pathophysiology of Alzheimerâs disease (AD). Peripheral immune cells including T cells circulate in the cerebrospinal fluid (CSF) of healthy adults and are found in the brains of AD patients and AD rodent models. Blocking entry of peripheral macrophages into the CNS was reported to increase amyloid burden in an AD mouse model. To assess inflammation in the 5xFAD (Tg) mouse model, we first quantified central and immune cell profiles in the deep cervical lymph nodes and spleen. In the brains of Tg mice, activated (MHCII+, CD45high, and Ly6Chigh) myeloid-derived CD11b+ immune cells are decreased while CD3+ T cells are increased as a function of age relative to non-Tg mice. These immunological changes along with evidence of increased mRNA levels for several cytokines suggest that immune regulation and trafficking patterns are altered in Tg mice. Levels of soluble Tumor Necrosis Factor (sTNF) modulate blood-brain barrier (BBB) permeability and are increased in CSF and brain parenchyma post-mortem in AD subjects and Tg mice. We report here that in vivo peripheral administration of XPro1595, a novel biologic that sequesters sTNF into inactive heterotrimers, reduced the age-dependent increase in activated immune cells in Tg mice, while decreasing the overall number of CD4+ T cells. In addition, XPro1595 treatment in vivo rescued impaired long-term potentiation (LTP) measured in brain slices in association with decreased AÎČ plaques in the subiculum. Selective targeting of sTNF may modulate brain immune cell infiltration, and prevent or delay neuronal dysfunction in AD
Tower and Aircraft Eddy Covariance Measurements of Water Vapor, Energy, and Carbon Dioxide Fluxes during SMACEX
Abstract
A network of eddy covariance (EC) and micrometeorological flux (METFLUX) stations over corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] canopies was established as part of the Soil MoistureâAtmosphere Coupling Experiment (SMACEX) in central Iowa during the summer of 2002 to measure fluxes of heat, water vapor, and carbon dioxide (CO2) during the growing season. Additionally, EC measurements of water vapor and CO2 fluxes from an aircraft platform complemented the tower-based measurements. Sensible heat, water vapor, and CO2 fluxes showed the greatest spatial and temporal variability during the early crop growth stage. Differences in all of the energy balance components were detectable between corn and soybean as well as within similar crops throughout the study period. Tower networkâaveraged fluxes of sensible heat, water vapor, and CO2 were observed to be in good agreement with area-averaged aircraft flux measurements
Safety of lumbar puncture in comatose children with clinical features of cerebral malaria
Objective: We assessed the independent association of lumbar puncture (LP) and death in Malawian children admitted to the hospital with the clinical features of cerebral malaria (CM). Methods: This was a retrospective cohort study in Malawian children with clinical features of CM. Allocation to LP was nonrandom and was associated with severity of illness. Propensity score-based analyses were used to adjust for this bias and assess the independent association between LP and mortality. Results: Data were available for 1,075 children: 866 (80.6%) underwent LP and 209 (19.4%) did not. Unadjusted mortality rates were lower in children who underwent LP (15.3% vs 26.7% in the no-LP group) but differences in covariates between the 2 groups suggested bias in LP allocation. After propensity score matching, all covariates were balanced. Propensity score-based analyses showed no change in mortality rate associated with LP: by inverse probability weighting, the average risk reduction was 2.0% at 12 hours (95% confidence interval -1.5% to 5.5%, p = 0.27) and 1.7% during hospital admission (95% confidence interval -4.5% to 7.9%, p = 0.60). Undergoing LP did not change the risk of mortality in subanalyses of children with severe brain swelling on MRI or in those with papilledema. Conclusion: In comatose children with suspected CM who were clinically stable, we found no evidence that LP increases mortality, even in children with objective signs of raised intracranial pressur
Comparing Breast Cancer Multiparameter Tests in the OPTIMA Prelim Trial: No Test Is More Equal Than the Others
Background: Previous reports identifying discordance between multiparameter tests at the individual patient level have been largely attributed to methodological shortcomings of multiple in silico studies. Comparisons between tests, when performed using actual diagnostic assays, have been predicted to demonstrate high degrees of concordance. OPTIMA prelim compared predicted risk stratification and subtype classification of different multiparameter tests performed directly on the same population.
Methods: Three hundred thirteen women with early breast cancer were randomized to standard (chemotherapy and endocrine therapy) or test-directed (chemotherapy if Oncotype DX recurrence score >25) treatment. Risk stratification was also determined with Prosigna (PAM50), MammaPrint, MammaTyper, NexCourse Breast (IHC4-AQUA), and conventional IHC4 (IHC4). Subtype classification was provided by Blueprint, MammaTyper, and Prosigna.
Results: Oncotype DX predicted a higher proportion of tumors as low risk (82.1%, 95% confidence interval [CI] = 77.8% to 86.4%) than were predicted low/intermediate risk using Prosigna (65.5%, 95% CIâ=â60.1% to 70.9%), IHC4 (72.0%, 95% CIâ=â66.5% to 77.5%), MammaPrint (61.4%, 95% CIâ=â55.9% to 66.9%), or NexCourse Breast (61.6%, 95% CIâ=â55.8% to 67.4%). Strikingly, the five tests showed only modest agreement when dichotomizing results between high vs low/intermediate risk. Only 119 (39.4%) tumors were classified uniformly as either low/intermediate risk or high risk, and 183 (60.6%) were assigned to different risk categories by different tests, although 94 (31.1%) showed agreement between four of five tests. All three subtype tests assigned 59.5% to 62.4% of tumors to luminal A subtype, but only 121 (40.1%) were classified as luminal A by all three tests and only 58 (19.2%) were uniformly assigned as nonluminal A. Discordant subtyping was observed in 123 (40.7%) tumors.
Conclusions: Existing evidence on the comparative prognostic information provided by different tests suggests that current multiparameter tests provide broadly equivalent risk information for the population of women with estrogen receptor (ER)âpositive breast cancers. However, for the individual patient, tests may provide differing risk categorization and subtype information
OPTIMA: A prospective randomized trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in early breast cancer
Background: Multi-parameter gene expression assays (MPAs) are widely used to estimate individual patient residual risk in hormone-sensitive HER2-negative node-negative early breast cancer, allowing patients with low risk to safely avoid chemotherapy. Evidence for MPA use in node-positive breast cancer is limited. OPTIMA (Optimal Personalised Treatment of early breast cancer usIng Multi-parameter Analysis) aims to validate MPAâs as predictors of chemotherapy sensitivity in a largely node-positive breast cancer population
Benchmarking global biodiversity of decapod crustaceans (Crustacea: Decapoda)
A new assessment of the global biodiversity of decapod Crustacea (to 31 December 2022) records 17,229 species in 2,550 genera and 203 families. These figures are derived from a well-curated dataset maintained on the online platform DecaNet, a subsidiary of the World Register of Marine Species (WoRMS). Distinct phases are recognised in the discovery process (as measured by species descriptions) corresponding to major historical and geopolitical time periods, with the current rate of species descriptions being more than three times higher than in the Victorian age of global exploration. Future trends are briefly explored, and it is recognised that a large number of species remain to be discovered and described
Short Timescale Evolution of the Polarized Radio Jet during V404 Cygni's 2015 Outburst
We present a high time resolution, multi-frequency linear polarization
analysis of Very Large Array (VLA) radio observations during some of the
brightest radio flaring (~1 Jy) activity of the 2015 outburst of V404 Cygni.
The VLA simultaneously captured the radio evolution in two bands (each with two
1 GHz base-bands), recorded at 5/7 GHz and 21/26 GHz, allowing for a broadband
polarimetric analysis. Given the source's high flux densities, we were able to
measure polarization on timescales of ~13 minutes, constituting one of the
highest temporal resolution radio polarimetric studies of a black hole X-ray
binary (BHXB) outburst to date. Across all base-bands, we detect variable,
weakly linearly polarized emission (<1%) with a single, bright peak in the
time-resolved polarization fraction, consistent with an origin in an evolving,
dynamic jet component. We applied two independent polarimetric methods to
extract the intrinsic electric vector position angles and rotation measures
from the 5 and 7 GHz base-band data and detected a variable intrinsic
polarization angle, indicative of a rapidly evolving local environment or a
complex magnetic field geometry. Comparisons to the simultaneous,
spatially-resolved observations taken with the Very Long Baseline Array at 15.6
GHz, do not show a significant connection between the jet ejections and the
polarization state.Comment: 24 pages, 9 figures, accepted by MNRA
Characterisation of paediatric brain tumours by their MRS metabolite profiles
1Hâmagnetic resonance spectroscopy (MRS) has the potential to improve the noninvasive diagnostic accuracy for paediatric brain tumours. However, studies analysing large, comprehensive, multicentre datasets are lacking, hindering translation to widespread clinical practice. Singleâvoxel MRS (pointâresolved singleâvoxel spectroscopy sequence, 1.5 T: echo time [TE] 23â37 ms/135â144 ms, repetition time [TR] 1500 ms; 3 T: TE 37â41 ms/135â144 ms, TR 2000 ms) was performed from 2003 to 2012 during routine magnetic resonance imaging for a suspected brain tumour on 340 children from five hospitals with 464 spectra being available for analysis and 281 meeting quality control. Mean spectra were generated for 13 tumour types. MannâWhitney Uâtests and KruskalâWallis tests were used to compare mean metabolite concentrations. Receiver operator characteristic curves were used to determine the potential for individual metabolites to discriminate between specific tumour types. Principal component analysis followed by linear discriminant analysis was used to construct a classifier to discriminate the three main central nervous system tumour types in paediatrics. Mean concentrations of metabolites were shown to differ significantly between tumour types. Large variability existed across each tumour type, but individual metabolites were able to aid discrimination between some tumour types of importance. Complete metabolite profiles were found to be strongly characteristic of tumour type and, when combined with the machine learning methods, demonstrated a diagnostic accuracy of 93% for distinguishing between the three main tumour groups (medulloblastoma, pilocytic astrocytoma and ependymoma). The accuracy of this approach was similar even when data of marginal quality were included, greatly reducing the proportion of MRS excluded for poor quality. Children's brain tumours are strongly characterised by MRS metabolite profiles readily acquired during routine clinical practice, and this information can be used to support noninvasive diagnosis. This study provides both key evidence and an important resource for the future use of MRS in the diagnosis of children's brain tumours
Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites.
Halide perovskite materials have promising performance characteristics for low-cost optoelectronic applications. Photovoltaic devices fabricated from perovskite absorbers have reached power conversion efficiencies above 25 per cent in single-junction devices and 28 per cent in tandem devices1,2. This strong performance (albeit below the practical limits of about 30 per cent and 35 per cent, respectively3) is surprising in thin films processed from solution at low-temperature, a method that generally produces abundant crystalline defects4. Although point defects often induce only shallow electronic states in the perovskite bandgap that do not affect performance5, perovskite devices still have many states deep within the bandgap that trap charge carriers and cause them to recombine non-radiatively. These deep trap states thus induce local variations in photoluminescence and limit the device performance6. The origin and distribution of these trap states are unknown, but they have been associated with light-induced halide segregation in mixed-halide perovskite compositions7 and with local strain8, both of which make devices less stable9. Here we use photoemission electron microscopy to image the trap distribution in state-of-the-art halide perovskite films. Instead of a relatively uniform distribution within regions of poor photoluminescence efficiency, we observe discrete, nanoscale trap clusters. By correlating microscopy measurements with scanning electron analytical techniques, we find that these trap clusters appear at the interfaces between crystallographically and compositionally distinct entities. Finally, by generating time-resolved photoemission sequences of the photo-excited carrier trapping process10,11, we reveal a hole-trapping character with the kinetics limited by diffusion of holes to the local trap clusters. Our approach shows that managing structure and composition on the nanoscale will be essential for optimal performance of halide perovskite devices
Genetic risk for neurodegenerative disorders, and its overlap with cognitive ability and physical function
Neurodegenerative disorders are associated with impaired cognitive function and worse physical health outcomes. This study aims to test whether polygenic risk for Alzheimerâs disease, Amyotrophic Lateral Sclerosis (ALS), or frontotemporal dementia (FTD) is associated with cognitive function and physical health in the UK Biobank, a cohort of healthy individuals. Group-based analyses were then performed to compare the top and bottom 10% for the three neurodegenerative polygenic risk scores; these groups were compared on the cognitive and physical health variables. Higher polygenic risk for AD, ALS, and FTD was associated with lower cognitive performance. Higher polygenic risk for FTD was also associated with increased forced expiratory volume in 1s and peak expiratory flow. A significant group difference was observed on the symbol digit substitution task between individuals with high polygenic risk for FTD and high polygenic risk for ALS. The results suggest some overlap between polygenic risk for neurodegenerative disorders, cognitive function and physical health
- âŠ