1,770 research outputs found
Increased platelet reactivity in idiopathic pulmonary fibrosis is mediated by a plasma factor
Introduction Idiopathic Pulmonary Fibrosis (IPF) is a progressive, incurable fibrotic interstitial lung disease with a prognosis worse than many cancers. Its pathogenesis is poorly understood. Activated platelets can release pro-fibrotic mediators that have the potential to contribute to lung fibrosis. We determine platelet reactivity in subjects with IPF compared to age-matched controls. Methods Whole blood flow cytometry was used to measure platelet-monocyte aggregate formation, platelet P-selectin expression and platelet fibrinogen binding at basal levels and following stimulation with platelet agonists. A plasma swap approach was used to assess the effect of IPF plasma on control platelets. Results Subjects with IPF showed greater platelet reactivity than controls. Platelet P-selectin expression was significantly greater in IPF patients than controls following stimulation with 0.1 µM ADP (1.9% positive ±0.5 (mean ± SEM) versus 0.7%±0.1; p = 0.03), 1 µM ADP (9.8%±1.3 versus 3.3%±0.8; p<0.01) and 10 µM ADP (41.3%±4.2 versus 22.5%±2.6; p<0.01). Platelet fibrinogen binding was also increased, and platelet activation resulted in increased platelet-monocyte aggregate formation in IPF patients. Re-suspension of control platelets in plasma taken from subjects with IPF resulted in increased platelet activation compared to control plasma. Conclusions IPF patients exhibit increased platelet reactivity compared with controls. This hyperactivity may result from the plasma environment since control platelets exhibit increased activation when exposed to IPF plasma
Impairments in motor coordination without major changes in cerebellar plasticity in the Tc1 mouse model of Down syndrome
Down syndrome (DS) is a genetic disorder arising from the presence of a third copy of human chromosome
21 (Hsa21). Recently, O’Doherty et al. [An aneuploid mouse strain carrying human chromosome 21 with Down
syndrome phenotypes. Science 309 (2005) 2033–2037] generated a trans-species aneuploid mouse line (Tc1)
that carries an almost complete Hsa21. The Tc1 mouse is the most complete animal model for DS currently
available. Tc1 mice show many features that relate to human DS, including alterations in memory, synaptic
plasticity, cerebellar neuronal number, heart development and mandible size. Because motor deficits are
one of the most frequently occurring features of DS, we have undertaken a detailed analysis of motor behaviour
in cerebellum-dependent learning tasks that require high motor coordination and balance. In addition,
basic electrophysiological properties of cerebellar circuitry and synaptic plasticity have been investigated.
Our results reveal that, compared with controls, Tc1 mice exhibit a higher spontaneous locomotor activity,
a reduced ability to habituate to their environments, a different gait and major deficits on several measures
of motor coordination and balance in the rota rod and static rod tests. Moreover, cerebellar long-term
depression is essentially normal in Tc1 mice, with only a slight difference in time course. Our observations
provide further evidence that support the validity of the Tc1 mouse as a model for DS, which will help us to
provide insights into the causal factors responsible for motor deficits observed in persons with DS
Altered sensory innervation and pain hypersensitivity in a model of young painful arthritic joints: short- and long-term effects
BACKGROUND: Early life experience can cause long-term alterations in the nociceptive processes underlying chronic pain, but the consequences of early life arthritic joint inflammation upon the sensory innervation of the joint is not known. Here, we measure pain sensitivity and sensory innervation in a young, juvenile and adult rodent model of arthritic joints and test the consequences of joint inflammation in young animals upon adult arthritic pain and joint innervation. METHODS: Unilateral ankle joint injections of complete Freund's adjuvant (CFA) (6-20 µl) were performed in young, postnatal day (P)8, adolescent (P21) and adult (P40) rats. A separate cohort of animals were injected at P8, and again at P40. Hindpaw mechanical sensitivity was assessed using von Frey monofilaments (vF) for 10 days. Nerve fibres were counted in sections through the ankle joint immunostained for calcitonin gene-related peptide (CGRP) and neurofilament 200 kDa (NF200). RESULTS: Ankle joint CFA injection increased capsular width at all ages. Significant mechanical pain hypersensitivity and increased number of joint CGRP + ve sensory fibres occurred in adolescent and adult, but not young, rats. Despite the lack of acute reaction, joint inflammation at a young age resulted in significantly increased pain hypersensitivity and CGRP+ fibre counts when the rats were re-inflamed as adults. CONCLUSIONS: Joint inflammation increases the sensory nociceptive innervation and induces acute pain hypersensitivity in juvenile and adult, but not in young rats. However, early life joint inflammation 'primes' the joint such that adult inflammatory pain behaviour and nociceptive nerve endings in the joint are significantly increased. Early life joint inflammation may be an important factor in the generation and maintenance of chronic arthritic pain
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An investigation into the impact of using various techniques to estimate Arctic surface air temperature anomalies
Time series of global and regional mean Surface Air Temperature (SAT) anomalies are a common metric used to estimate recent climate change. Various techniques can be used to create these time series from meteorological station data. The degree of difference arising from using five different techniques, based on existing temperature anomaly dataset techniques, to estimate Arctic SAT anomalies over land and sea ice were investigated using reanalysis data as a testbed. Techniques which interpolated anomalies were found to result in smaller errors than non-interpolating techniques relative to the reanalysis reference. Kriging techniques provided the smallest errors in estimates of Arctic anomalies and Simple Kriging was often the best kriging method in this study, especially over sea ice. A linear interpolation technique had, on average, Root Mean Square Errors (RMSEs) up to 0.55 K larger than the two kriging techniques tested. Non-interpolating techniques provided the least representative anomaly estimates. Nonetheless, they serve as useful checks for confirming whether estimates from interpolating techniques are reasonable. The interaction of meteorological station coverage with estimation techniques between 1850 and 2011 was simulated using an ensemble dataset
comprising repeated individual years (1979-2011). All techniques were found to have larger RMSEs for earlier station coverages. This supports calls for increased data sharing and data rescue, especially in sparsely observed regions such as the Arctic
Aging, jamming, and the limits of stability of amorphous solids
Apart from not having crystallized, supercooled liquids can be considered as
being properly equilibrated and thus can be described by a few thermodynamic
control variables. In contrast, glasses and other amorphous solids can be
arbitrarily far away from equilibrium and require a description of the history
of the conditions under which they formed. In this paper we describe how the
locality of interactions intrinsic to finite-dimensional systems affects the
stability of amorphous solids far off equilibrium. Our analysis encompasses
both structural glasses formed by cooling and colloidal assemblies formed by
compression. A diagram outlining regions of marginal stability can be adduced
which bears some resemblance to the quasi-equilibrium replica meanfield theory
phase diagram of hard sphere glasses in high dimensions but is distinct from
that construct in that the diagram describes not true phase transitions but
kinetic transitions that depend on the preparation protocol. The diagram
exhibits two distinct sectors. One sector corresponds to amorphous states with
relatively open structures, the other to high density, more closely-packed
ones. The former transform rapidly owing to there being motions with no free
energy barriers; these motions are string-like locally. In the dense region,
amorphous systems age via compact activated reconfigurations. The two regimes
correspond, in equilibrium, to the collisional or uniform liquid and the so
called landscape regime, respectively. These are separated by a spinodal line
of dynamical crossovers. Owing to the rigidity of the surrounding matrix in the
landscape, high-density part of the diagram, a sufficiently rapid pressure
quench adds compressive energy which also leads to an instability toward
string-like motions with near vanishing barriers. (SEE REST OF ABSTRACT IN THE
ARTICLE.)Comment: submitted to J Phys Chem
Multifocal Aggressive Squamous Cell Carcinomas Induced by Prolonged Voriconazole Therapy: A Case Report
Voriconazole is a treatment for severe fungal infections. Prolonged voriconazole therapy may induce skin reactions, with 1% of severe photosensitivity accidents. Recently the imputability of voriconazole in skin carcinogenesis has been suggested. This report concerns a 55-year-old man suffering from pulmonary aspergillosis who presented a phototoxic reaction a few months after introduction of voriconazole, followed by multiple squamous cell carcinomas of sun-exposed skin areas. After voriconazole discontinuation, no new carcinoma was observed. The detection of EBV and HPV in skin lesions was negative. Exploration of gene mutations involved in skin carcinogenesis showed two variants of the MICR gene. The occurrence of multiple, recurrent, aggressive squamous cell carcinomas is rare with voriconazole, but its imputability is strongly suggested. A plausible hypothesis is that several factors including voriconazole uptake, immunosuppression, and genetic background could explain the phenotype of fast-developing skin carcinomas. Voriconazole therapy should be accompanied by stringent photoprotection and skin monitoring
Optical response of superfluid state in dilute atomic Fermi-Dirac gases
We theoretically study the propagation of light in a Fermi-Dirac gas in the
presence of a superfluid state. BCS pairing between atoms in different
hyperfine levels may significantly increase the optical linewidth and line
shift of a quantum degenerate Fermi-Dirac gas and introduce a local-field
correction that, under certain conditions, dramatically dominates over the
Lorentz-Lorenz shift. These optical properties could possibly unambiguously
sign the presence of the superfluid state and determine the value of the BCS
order parameter.Comment: 5 pages, 2 figure
COPD in young patients: A pre-specified analysis of the four-year trial of tiotropium (UPLIFT)
SummaryWhilst recent large-scale studies have provided much evidence on the natural history and therapeutic response in patients with chronic obstructive pulmonary disease (COPD), relatively little is known about the effect in younger patients.We report a pre-specified post-hoc analysis of 356 patients with COPD ≤ 50 years old from the four year randomised, double blind placebo controlled Understanding Potential Long Term Impact on Function with Tiotropium (UPLIFT) trial. Inclusion criteria included a post-bronchodilator forced expiratory volume in 1 s (FEV1) of ≤70%, FEV1/FVC < 0.70, age ≥40 years, and smoking history of ≥10 pack years.Younger patients had a mean FEV1 of 1.24 L (39% predicted) and an impaired health-related quality of life (St. George’s Respiratory Questionnaire (SGRQ)) compared to the entire UPLIFT population. There were 40.2% women and 51.1% current smokers in the younger age group. Tiotropium was associated with a sustained improvement in spirometry and SGRQ. Mean decline in post-bronchodilator FEV1 was 58 ml/year (placebo) vs. 38 ml/year (tiotropium) (p = 0.01). Corresponding values for pre-bronchodilator FEV1 were 41 ml/year (placebo) compared with 34 ml/year (tiotropium) (p = 0.34). The hazard ratio (95%CI) for an exacerbation in the younger age group was 0.87(0.68, 1.13)). The rate of exacerbations was reduced by tiotropium (rate ratio (95%CI) = 0.73(0.56, 0.95)).Tiotropium resulted in sustained bronchodilation, improved quality of life, and a decreased exacerbation rate in younger patients. Tiotropium also resulted in a significant reduction in the decline in post-bronchodilator FEV1, suggesting possible disease modification by tiotropium in younger patients with COPD
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