434 research outputs found
Favorable outcome of early treatment of new onset child and adolescent migraine-implications for disease modification.
There is evidence that the prevalence of migraine in children and adolescents may be increasing. Current theories of migraine pathophysiology in adults suggest activation of central cortical and brainstem pathways in conjunction with the peripheral trigeminovascular system, which ultimately results in release of neuropeptides, facilitation of central pain pathways, neurogenic inflammation surrounding peripheral vessels, and vasodilatation. Although several risk factors for frequent episodic, chronic, and refractory migraine have been identified, the causes of migraine progression are not known. Migraine pathophysiology has not been fully evaluated in children. In this review, we will first discuss the evidence that early therapeutic interventions in the child or adolescent new onset migraineur, may halt or limit progression and disability. We will then review the evidence suggesting that many adults with chronic or refractory migraine developed their migraine as children or adolescents and may not have been treated adequately with migraine-specific therapy. Finally, we will show that early, appropriate and optimal treatment of migraine during childhood and adolescence may result in disease modification and prevent progression of this disease
Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists
Background
 
Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded.
Methods
 
We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis.
Findings
 
Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis.
Conclusion
 
Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice
Intrinsic paramagnetic meissner effect due to s-wave odd-frequency superconductivity
In 1933, Meissner and Ochsenfeld reported the expulsion of magnetic flux, the
diamagnetic Meissner effect, from the interior of superconducting lead. This
discovery was crucial in formulating the Bardeen-Cooper-Schrieffer (BCS) theory
of superconductivity. In exotic superconducting systems BCS theory does not
strictly apply. A classical example is a superconductor-magnet hybrid system
where magnetic ordering breaks time-reversal symmetry of the superconducting
condensate and results in the stabilisation of an odd-frequency superconducting
state. It has been predicted that under appropriate conditions, odd-frequency
superconductivity should manifest in the Meissner state as fluctuations in the
sign of the magnetic susceptibility meaning that the superconductivity can
either repel (diamagnetic) or attract (paramagnetic) external magnetic flux.
Here we report local probe measurements of faint magnetic fields in a Au/Ho/Nb
trilayer system using low energy muons, where antiferromagnetic Ho (4.5 nm)
breaks time-reversal symmetry of the proximity induced pair correlations in Au.
From depth-resolved measurements below the superconducting transition of Nb we
observe a local enhancement of the magnetic field in Au that exceeds the
externally applied field, thus proving the existence of an intrinsic
paramagnetic Meissner effect arising from an odd-frequency superconducting
state.J.W.A.R. acknowledges financial support from the Royal Society through a University Research Fellowship. J.W.A.R. and A.D.B. acknowledge financial support from the UK EPSRC through NanoDTC EP/G037221/1 and the Leverhulme Trust through an International Network Grant (IN-2013-033). A.D.B. also acknowledges additional financial support from the Schiff Foundation. X.L.W. and J.H.Z. acknowledge support from the MOST of China (2015CB921500). J.L. acknowledges support from the Outstanding Academic Fellows programme at NTNU, the Norwegian Research Council Grant (205591, FRINAT, 216700). J. L., J.W.A.R, and A.D.B. finally acknowledge support from the COST Action MP-1201 'Novel Functionalities through Optimized Confinement of Condensate and Fields.' S.L. and M.G.F. acknowledge the support of the EPSRC through Grant No. EP/J01060X. The muSR measurements were performed at the Swiss Muon Source (SµS), at the Paul Scherrer Institute in Villigen, Switzerland. The project has also received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under the NMI3-II Grant number 283883.This is the final version of the article. It first appeared from APS via http://dx.doi.org/10.1103/PhysRevX.5.04102
Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin
X-Ray Spectroscopy of Stars
(abridged) Non-degenerate stars of essentially all spectral classes are soft
X-ray sources. Low-mass stars on the cooler part of the main sequence and their
pre-main sequence predecessors define the dominant stellar population in the
galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense,
of X-ray spectra from the solar corona. X-ray emission from cool stars is
indeed ascribed to magnetically trapped hot gas analogous to the solar coronal
plasma. Coronal structure, its thermal stratification and geometric extent can
be interpreted based on various spectral diagnostics. New features have been
identified in pre-main sequence stars; some of these may be related to
accretion shocks on the stellar surface, fluorescence on circumstellar disks
due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot
stars clearly dominate the interaction with the galactic interstellar medium:
they are the main sources of ionizing radiation, mechanical energy and chemical
enrichment in galaxies. High-energy emission permits to probe some of the most
important processes at work in these stars, and put constraints on their most
peculiar feature: the stellar wind. Here, we review recent advances in our
understanding of cool and hot stars through the study of X-ray spectra, in
particular high-resolution spectra now available from XMM-Newton and Chandra.
We address issues related to coronal structure, flares, the composition of
coronal plasma, X-ray production in accretion streams and outflows, X-rays from
single OB-type stars, massive binaries, magnetic hot objects and evolved WR
stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures
  (partly multiple); some corrections made after proof stag
The Lung Screen Uptake Trial (LSUT): protocol for a randomised controlled demonstration lung cancer screening pilot testing a targeted invitation strategy for high risk and ‘hard-to-reach’ patients
Background Participation in low-dose CT (LDCT) lung cancer screening offered in the trial context has been poor, especially among smokers from socioeconomically deprived backgrounds; a group for whom the risk-benefit ratio is improved due to their high risk of lung cancer. Attracting high risk participants is essential to the success and equity of any future screening programme. This study will investigate whether the observed low and biased uptake of screening can be improved using a targeted invitation strategy. Methods/design A randomised controlled trial design will be used to test whether targeted invitation materials are effective at improving engagement with an offer of lung cancer screening for high risk candidates. Two thousand patients aged 60–75 and recorded as a smoker within the last five years by their GP, will be identified from primary care records and individually randomised to receive either intervention invitation materials (which take a targeted, stepped and low burden approach to information provision prior to the appointment) or control invitation materials. The primary outcome is uptake of a nurse-led ‘lung health check’ hospital appointment, during which patients will be offered a spirometry test, an exhaled carbon monoxide (CO) reading, and an LDCT if eligible. Initial data on demographics (i.e. age, sex, ethnicity, deprivation score) and smoking status will be collected in primary care and analysed to explore differences between attenders and non-attenders with respect to invitation group. Those who attend the lung health check will have further data on smoking collected during their appointment (including pack-year history, nicotine dependence and confidence to quit). Secondary outcomes will include willingness to be screened, uptake of LDCT and measures of informed decision-making to ensure the latter is not compromised by either invitation strategy. Discussion If effective at improving informed uptake of screening and reducing bias in participation, this invitation strategy could be adopted by local screening pilots or a national programme. Trial registration This study was registered with the ISRCTN (International Standard Registered Clinical/soCial sTudy Number : ISRCTN21774741) on the 23rd September 2015 and the NIH ClinicalTrials.gov database (NCT0255810) on the 22nd September 2015
Brane-World Gravity
The observable universe could be a 1+3-surface (the "brane") embedded in a
1+3+\textit{d}-dimensional spacetime (the "bulk"), with Standard Model
particles and fields trapped on the brane while gravity is free to access the
bulk. At least one of the \textit{d} extra spatial dimensions could be very
large relative to the Planck scale, which lowers the fundamental gravity scale,
possibly even down to the electroweak ( TeV) level. This revolutionary
picture arises in the framework of recent developments in M theory. The
1+10-dimensional M theory encompasses the known 1+9-dimensional superstring
theories, and is widely considered to be a promising potential route to quantum
gravity. At low energies, gravity is localized at the brane and general
relativity is recovered, but at high energies gravity "leaks" into the bulk,
behaving in a truly higher-dimensional way. This introduces significant changes
to gravitational dynamics and perturbations, with interesting and potentially
testable implications for high-energy astrophysics, black holes, and cosmology.
Brane-world models offer a phenomenological way to test some of the novel
predictions and corrections to general relativity that are implied by M theory.
This review analyzes the geometry, dynamics and perturbations of simple
brane-world models for cosmology and astrophysics, mainly focusing on warped
5-dimensional brane-worlds based on the Randall--Sundrum models. We also cover
the simplest brane-world models in which 4-dimensional gravity on the brane is
modified at \emph{low} energies -- the 5-dimensional Dvali--Gabadadze--Porrati
models. Then we discuss co-dimension two branes in 6-dimensional models.Comment: A major update of Living Reviews in Relativity 7:7 (2004)
  "Brane-World Gravity", 119 pages, 28 figures, the update contains new
  material on RS perturbations, including full numerical solutions of
  gravitational waves and scalar perturbations, on DGP models, and also on 6D
  models. A published version in Living Reviews in Relativit
Racism as a determinant of health: a systematic review and meta-analysis
Despite a growing body of epidemiological evidence in recent years documenting the health impacts of racism, the cumulative evidence base has yet to be synthesized in a comprehensive meta-analysis focused specifically on racism as a determinant of health. This meta-analysis reviewed the literature focusing on the relationship between reported racism and mental and physical health outcomes. Data from 293 studies reported in 333 articles published between 1983 and 2013, and conducted predominately in the U.S., were analysed using random effects models and mean weighted effect sizes. Racism was associated with poorer mental health (negative mental health: r = -.23, 95% CI [-.24,-.21], k = 227; positive mental health: r = -.13, 95% CI [-.16,-.10], k = 113), including depression, anxiety, psychological stress and various other outcomes. Racism was also associated with poorer general health (r = -.13 (95% CI [-.18,-.09], k = 30), and poorer physical health (r = -.09, 95% CI [-.12,-.06], k = 50). Moderation effects were found for some outcomes with regard to study and exposure characteristics. Effect sizes of racism on mental health were stronger in cross-sectional compared with longitudinal data and in non-representative samples compared with representative samples. Age, sex, birthplace and education level did not moderate the effects of racism on health. Ethnicity significantly moderated the effect of racism on negative mental health and physical health: the association between racism and negative mental health was significantly stronger for Asian American and Latino(a) American participants compared with African American participants, and the association between racism and physical health was significantly stronger for Latino(a) American participants compared with African American participants.<br /
L-Plastin nanobodies perturb matrix degradation, podosome formation, stability and lifetime in THP-1 macrophages
Podosomes are cellular structures acting as degradation ‘hot-spots’ in monocytic cells. They appear as dot-like structures at the ventral cell surface, enriched in F-actin and actin regulators, including gelsolin and L-plastin. Gelsolin is an ubiquitous severing and capping protein, whereas L-plastin is a leukocyte-specific actin bundling protein. The presence of the capping protein CapG in podosomes has not yet been investigated. We used an innovative approach to investigate the role of these proteins in macrophage podosomes by means of nanobodies or Camelid single domain antibodies. Nanobodies directed against distinct domains of gelsolin, L-plastin or CapG were stably expressed in macrophage-like THP-1 cells. CapG was not enriched in podosomes. Gelsolin nanobodies had no effect on podosome formation or function but proved very effective in tracing distinct gelsolin populations. One gelsolin nanobody specifically targets actin-bound gelsolin and was effectively enriched in podosomes. A gelsolin nanobody that blocks gelsolin-G-actin interaction was not enriched in podosomes demonstrating that the calcium-activated and actin-bound conformation of gelsolin is a constituent of podosomes. THP-1 cells expressing inhibitory L-plastin nanobodies were hampered in their ability to form stable podosomes. Nanobodies did not perturb Ser5 phosphorylation of L-plastin although phosphorylated L-plastin was highly enriched in podosomes. Furthermore, nanobody-induced inhibition of L-plastin function gave rise to an irregular and unstable actin turnover of podosomes, resulting in diminished degradation of the underlying matrix. Altogether these results indicate that L-plastin is indispensable for podosome formation and function in macrophages
The Architecture of the Adhesive Apparatus of Cultured Osteoclasts: From Podosome Formation to Sealing Zone Assembly
BACKGROUND: Osteoclasts are bone-degrading cells, which play a central role in physiological bone remodeling. Unbalanced osteoclast activity is largely responsible for pathological conditions such as osteoporosis. Osteoclasts develop specialized adhesion structures, the so-called podosomes, which subsequently undergo dramatic reorganization into sealing zones. These ring-like adhesion structures, which delimit the resorption site, effectively seal the cell to the substrate forming a diffusion barrier. The structural integrity of the sealing zone is essential for the cell ability to degrade bone, yet its structural organization is poorly understood. PRINCIPAL FINDINGS: Combining high-resolution scanning electron microscopy with fluorescence microscopy performed on the same sample, we mapped the molecular architecture of the osteoclast resorptive apparatus from individual podosomes to the sealing zone, at an unprecedented resolution. Podosomes are composed of an actin-bundle core, flanked by a ring containing adhesion proteins connected to the core via dome-like radial actin fibers. The sealing zone, hallmark of bone-resorbing osteoclasts, consists of a dense array of podosomes communicating through a network of actin filaments, parallel to the substrate and anchored to the adhesive plaque domain via radial actin fibers. SIGNIFICANCE: The sealing zone of osteoclasts cultured on bone is made of structural units clearly related to individual podosomes. It differs from individual or clustered podosomes in the higher density and degree of inter-connectivity of its building blocks, thus forming a unique continuous functional structure connecting the cell to its extracellular milieu. Through this continuous structure, signals reporting on the substrate condition may be transmitted to the whole cell, modulating the cell response under physiological and pathological conditions
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