763 research outputs found
A survey of X-ray emission from 100 kpc radio jets
We have completed a Chandra snapshot survey of 54 radio jets that are
extended on arcsec scales. These are associated with flat spectrum radio
quasars spanning a redshift range z=0.3 to 2.1. X-ray emission is detected from
the jet of approximately 60% of the sample objects. We assume minimum energy
and apply conditions consistent with the original Felten-Morrison calculations
in order to estimate the Lorentz factors and the apparent Doppler factors. This
allows estimates of the enthalpy fluxes, which turn out to be comparable to the
radiative luminosities.Comment: Conference Proceedings IAU Symposium No. 313, Extragalactic jets from
every angle, pp. 219-224, 4 figure
Corticosterone Regulates Both Naturally Occurring and Cocaine‐Induced Dopamine Signaling by Selectively Decreasing Dopamine Uptake
Stressful and aversive events promote maladaptive reward‐seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our laboratory and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine\u27s effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast‐scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine
The American English version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)
The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the American English language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach\u2019s alpha, interscale correlations, test\u2013retest reliability, and construct validity (convergent and discriminant validity). A total of 315 JIA patients (5.1% systemic, 31.1% oligoarticular, 34% RF negative polyarthritis, 29.8% other categories) and 98 healthy children, were enrolled in three centres. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the American English version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research
The 4th NextGen Therapies for SJIA and MAS: part 1 the elephant in the room: diagnostic/classification criteria for systemic juvenile idiopathic arthritis and adult-onset still's disease
Currently, the criteria used to classify patients with SJIA are different from those used for AOSD. However, it has been recognized that the existing terms are too narrow, subdividing the Still's population unnecessarily between pediatric-onset and adult-onset disease and excluding an appreciable group of children in whom overt arthritis is delayed or absent. Government regulators and insurers rely upon the guidance of subject experts to provide disease definitions, and when these definitions are flawed, to provide new and better ones. The classification session at the NextGen 2022 conference helped to serve this purpose, establishing the need for a revised definitional system that transcends the fault lines that remain in existing definitions
Multiagency approaches to preventing sudden unexpected death in infancy (SUDI): a review and analysis of UK policies
Background Recent reviews of sudden unexpected deaths in infancy (SUDI) in England recommend a multiagency working (MAW) approach to prevention but lack clear guidance around how this might be implemented.Aims In England, local authorities commission and oversee public health services. This review examines how local authority policies address implementation of MAW for SUDI prevention to understand local variations and identify strengths and weaknesses.Methods Using a comprehensive list of all metropolitan, county, unitary councils and London boroughs in England, we systematically searched local authority websites for relevant published documents and submitted freedom of information (FOI) requests where policies or guidance for SUDI prevention had not been sourced online. We extracted data from documents using a standardised form to summarise policy contents which were then collated, described and appraised.Findings We searched the websites of 152 council and London boroughs, identifying 36 relevant policies and guidelines for staff. We submitted 116 FOI requests which yielded 64 responses including six valid documents: 45% (52/116) of local authorities did not respond. Seventeen councils shared the same guidance under safeguarding partnerships; removal of duplicates resulted in 26 unique documents. Only 15% (4/26) of the documents included a detailed plan for how MAW approaches were to be implemented despite 73% (19/26) of the documents mentioning the importance of engaging the MAW in raising awareness of safe sleep for babies with vulnerable families. Five areas of variation were identified across policies: (1) scope, (2) responsibilities, (3) training, (4) implementation and (5) evaluation.Conclusions There are discrepancies between local authorities in England in whether and how MAW for SUDI prevention is carried out. Strengths and weaknesses of approaches are identified to inform future development of MAW for SUDI prevention
Safety of celecoxib and nonselective nonsteroidal anti-inflammatory drugs in juvenile idiopathic arthritis: results of the phase 4 registry
Background
This study aimed to assess long-term safety and developmental data on juvenile idiopathic arthritis (JIA) patients treated in routine clinical practice with celecoxib or nonselective nonsteroidal anti-inflammatory drugs (nsNSAIDs). Methods
Children aged ≥2 to \u3c18 years with rheumatoid-factor–positive or –negative polyarthritis, persistent or extended oligoarthritis, or systemic arthritis were enrolled into this prospective, observational, multicenter standard-of-care registry. Eligible patients were newly or recently prescribed (≤6 months) an nsNSAID or celecoxib. Enrolled patients were followed to the end of the study, whether they remained on the original NSAID, switched, or discontinued therapy altogether. All adverse events (AEs) regardless of severity were captured in the database. Results
A total of 274 patients (nsNSAID, n = 219; celecoxib, n = 55) were observed for 410 patient-years of observation. Naproxen, meloxicam, and nabumetone were the most frequently used nsNSAIDs. At baseline, the celecoxib group was older, had a numerically longer median time since diagnosis, and a numerically higher proportion of patients with a history of gastrointestinal-related NSAID intolerance. AEs reported were those frequently observed with NSAID treatment and were similar across groups (nsNSAIDs: 52.0%; celecoxib: 52.9%). Twelve unique patients experienced a total of 18 serious AEs; the most frequent were infections, and none was attributed to NSAID use. Conclusions
The safety profile of celecoxib and nsNSAIDs appears similar overall. The results from this registry, ongoing pharmacovigilance, and the phase 3 trial that led to the approval of celecoxib for children with JIA provide evidence that the benefit-risk for celecoxib treatment in JIA remains positive
TCR repertoire sequencing identifies synovial Treg cell clonotypes in the bloodstream during active inflammation in human arthritis
Objectives The imbalance between effector and regulatory T (Treg) cells is crucial in the pathogenesis of autoimmune arthritis. Immune responses are often investigated in the blood because of its accessibility, but circulating lymphocytes are not representative of those found in inflamed tissues. This disconnect hinders our understanding of the mechanisms underlying disease. Our goal was to identify Treg cells implicated in autoimmunity at the inflamed joints, and also readily detectable in the blood upon recirculation. Methods We compared Treg cells of patients with juvenile idiopathic arthritis responding or not to therapy by using: (i) T cell receptor (TCR) sequencing, to identify clonotypes shared between blood and synovial fluid; (ii) FOXP3 Treg cell-specific demethylated region DNA methylation assays, to investigate their stability and (iii) flow cytometry and suppression assays to probe their tolerogenic functions. Results We found a subset of synovial Treg cells that recirculated into the bloodstream of patients with juvenile idiopathic and adult rheumatoid arthritis. These inflammation-associated (ia)Treg cells, but not other blood Treg cells, expanded during active disease and proliferated in response to their cognate antigens. Despite the typical inflammatory-skewed balance of immune mechanisms in arthritis, iaTreg cells were stably committed to the regulatory lineage and fully suppressive. A fraction of iaTreg clonotypes were in common with pathogenic effector T cells. Conclusions Using an innovative antigen-agnostic approach, we uncovered a population of bona fide synovial Treg cells readily accessible from the blood and selectively expanding during active disease, paving the way to non-invasive diagnostics and better understanding of the pathogenesis of autoimmunity
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The ModFOLD4 server for the quality assessment of 3D protein models
Once you have generated a 3D model of a protein,
how do you know whether it bears any resemblance
to the actual structure? To determine the usefulness
of 3D models of proteins, they must be assessed in
terms of their quality by methods that predict their
similarity to the native structure. The ModFOLD4
server is the latest version of our leading independent
server for the estimation of both the global and
local (per-residue) quality of 3D protein models. The
server produces both machine readable and graphical
output, providing users with intuitive visual
reports on the quality of predicted protein tertiary
structures. The ModFOLD4 server is freely available
to all at: http://www.reading.ac.uk/bioinf/ModFOLD/
MolProbity: all-atom structure validation for macromolecular crystallography
MolProbity structure validation will diagnose most local errors in macromolecular crystal structures and help to guide their correction
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