857 research outputs found

    MicroRNA-155 regulates monocyte chemokine and chemokine receptor expression in Rheumatoid Arthritis

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    Objectives: To test the hypothesis that miR-155 regulates monocyte migratory potential via modulation of chemokine and chemokine receptor expression in rheumatoid arthritis (RA); and thereby is associated with disease activity. Methods: miR-155 copy-number in monocytes from peripheral blood (PB) of healthy (n=22), RA (n=24), and RA synovial fluid (SF; n=11) were assessed by real time- PCR using synthetic miR-155 as quantitative standard. To evaluate the functional impact of miR-155, human monocytes were transfected with control or miR-155 mimic and the effect on transcript levels, and production of chemokines was evaluated by TLDA and multiplex assays. A comparative study evaluated constitutive chemokine receptor expression in miR-155-/- and wild-type murine (CD115+Ly6C+Ly6G-) monocytes. Results: Compared with healthy monocytes, miR-155 copy-number was higher in RA PB and SF monocytes (PB p<0.01, and SF p<0.0001). MiR-155 copy-number in RA PB monocytes were higher in ACPA positive compared with ACPA negative patients (p=0.033) and correlated (95% C.I.) with DAS28 (ESR), R=0.728 (0.460, 0.874), with tender, R=0.631 (0.306, 0.824) and swollen, R=0.503 (0.125, 0.753) joint counts. Enforced-expression of miR-155 in RA monocytes stimulated the production of CCL3, CCL4, CCL5, CCL8; up-regulated CCR7 expression and down-regulated CCR2. Conversely, miR155-/- monocytes showed down-regulated CCR7 and upregulated CCR2 expression. Conclusions: Given the observed correlations with disease activity, these data provide strong evidence that miR-155 can contribute to RA pathogenesis by regulating chemokine production and pro-inflammatory chemokine receptor expression, thereby promoting inflammatory cell recruitment and retention in the RA synovium

    N-methyl-N-alkylpyrrolidinium nonafluoro-1-butanesulfonate salts : Ionic liquid properties and plastic crystal behaviour

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    A series of N-methyl-N-alkylpyrrolidinium nonafluoro-1-butanesulfonate salts were synthesised and characterised. The thermophysical characteristics of this family of salts have been investigated with respect to potential use as ionic liquids and solid electrolytes. N-Methyl-N-butylpyrrolidinium nonafluoro-1-butanesulfonate (p1,4NfO) has the lowest melting point of the family, at 94 &deg;C. Electrochemical analysis of p1,4 NfO in the liquid state shows an electrochemical window of ~6 V. All compounds exhibit one or more solid&ndash;solid transitions at sub-ambient temperatures, indicating the existence of plastic crystal phases.<br /

    Ultrasound and Microbubbles Promote the Retention of Fluorescent Compounds in the Small Intestine

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    Focused ultrasound (US) is a novel means to increase the passage of medication through the wall of the small intestine. The purpose of this study was to determine whether US and microbubbles (MBs) can facilitate delivery of macromolecular therapeutic agents across the intestinal epithelium in vitro and in vivo. In vitro experiments involved delivery of compounds across a cell monolayer, namely Caco-2 cells cultured on ThinCert filters. The cells were cultured for a minimum of 3 weeks to mimic the polarised intestinal epithelium. A suspension of dextran with or without MBs, prepared in growth medium, was introduced into the apical chamber of the ThinCert with a syringe pump through a channel in the centre of a miniature focused US transducer (4 MHz, 1 MPa PNP). Each in vivo experiment involved a tethered endoscopic capsule with an US transducer and a delivery channel inserted into the small intestine of a terminally anaesthetised pig via a surgical stoma. The amount of fluorescent dextran delivered across the Caco-2 monolayer when employing US, MBs and dextran was higher than the amount delivered with dextran alone. With this approach, fluorescent marking of the wall of the small intestine was achieved in vivo by applying US and MBs. Our work indicates that US has potential for application in targeted treatment of gastrointestinal disease and oral drug delivery

    Cervical spine injuries and collar complications in severely injured paediatric trauma patients

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    Study design:A retrospective registry review.Objectives:To determine the incidence of cervical spine (CS) injuries and collar complications in severely injured paediatric trauma patients.Setting:Regional Trauma Centre, Children\u27s Hospital.Methods:A retrospective review of 365 paediatric severe trauma patients (0-17 years), defined as an Injury Severity Score (ISS)ā‰„12, admitted to the paediatric intensive care unit (PICU).Results:Clinically significant CS injuries occurred in 5% (n=18/365) of trauma patients, in 9% (n=13/149) of traumatic brain injury (TBI) patients and in 11% (n=6/56) of in-hospital trauma deaths. CS injuries were suspected before imaging in 33% (n=6/18) of patients based on either motor/sensory impairment or shock. CS injuries were deemed unstable in 61% (n=11/18) of patients. Patients with CS injuries had higher ISS, and longer PICU and hospital stays (P\u3c0.05). CS collar complications occurred in 10% of patients, mainly identified by day 6 and consisting of either erythema or ulcers. Patients with CS collar complications were older and more likely to have TBI, lower Glasgow Coma Scale (GCS) scores, longer PICU and hospital stays, and increased days to CS clearance (P\u3c0.05). Three CS X-rays, together with flexion/extension views, were used most frequently for CS clearance.Conclusion: CS injuries were prevalent in severely injured paediatric trauma patients, particularly in those with TBI and in nonsurvivors. CS collar complications were associated with a lower GCS and longer CS clearance times. Attention to CS collar management protocols and earlier CS clearance with computed tomography/magnetic resonance imaging in obtunded patients might reduce CS collar complications. Ā© 2013 International Spinal Cord Society. All rights reserved

    Cervical spine injuries and collar complications in severely injured paediatric trauma patients

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    Study design:A retrospective registry review.Objectives:To determine the incidence of cervical spine (CS) injuries and collar complications in severely injured paediatric trauma patients.Setting:Regional Trauma Centre, Children\u27s Hospital.Methods:A retrospective review of 365 paediatric severe trauma patients (0-17 years), defined as an Injury Severity Score (ISS)ā‰„12, admitted to the paediatric intensive care unit (PICU).Results:Clinically significant CS injuries occurred in 5% (n=18/365) of trauma patients, in 9% (n=13/149) of traumatic brain injury (TBI) patients and in 11% (n=6/56) of in-hospital trauma deaths. CS injuries were suspected before imaging in 33% (n=6/18) of patients based on either motor/sensory impairment or shock. CS injuries were deemed unstable in 61% (n=11/18) of patients. Patients with CS injuries had higher ISS, and longer PICU and hospital stays (P\u3c0.05). CS collar complications occurred in 10% of patients, mainly identified by day 6 and consisting of either erythema or ulcers. Patients with CS collar complications were older and more likely to have TBI, lower Glasgow Coma Scale (GCS) scores, longer PICU and hospital stays, and increased days to CS clearance (P\u3c0.05). Three CS X-rays, together with flexion/extension views, were used most frequently for CS clearance.Conclusion: CS injuries were prevalent in severely injured paediatric trauma patients, particularly in those with TBI and in nonsurvivors. CS collar complications were associated with a lower GCS and longer CS clearance times. Attention to CS collar management protocols and earlier CS clearance with computed tomography/magnetic resonance imaging in obtunded patients might reduce CS collar complications. Ā© 2013 International Spinal Cord Society. All rights reserved

    Effects of resistance exercise, collagen ingestion and circulating oestrogen concentration on collagen synthesis in a female athlete: a case report.

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    We investigated the effects of resistance exercise (RE), hydrolysed collagen (HC) ingestion and circulating oestrogen concentration on collagen synthesis in a naturally menstruating female CrossFit athlete. In a double-blind, randomised cross-over design, the participant (36 years; height 1.61 m; mass 82.6 kg) consumed 0 or 30 g HC prior to performing back-squat RE when endogenous circulating oestrogen concentration was low (onset of menses, OM) and high (late follicular phase, LF) during two consecutive menstrual cycles. Ten 5-mL blood samples were collected during each of the four interventions to analyse concentrations of serum 17Ī²-oestradiol, and biomarkers of type I collagen turnover, that is serum procollagen type I N-terminal propeptide (PINP, a biomarker of collagen synthesis) and plasma Ī²-isomerised C-terminal telopeptide of type I collagen (Ī²-CTX, a biomarker of collagen breakdown), as well as the serum concentration of 18 collagen amino acids. 17Ī²-Oestradiol concentration was 5-fold higher at LF (891 Ā± 116 pmol Lāˆ’1) than OM (180 Ā± 13 pmol Lāˆ’1). The PINP concentration Ɨ time area under the curve (AUC) was higher in the 30 g HC OM intervention (201 Ī¼g Lāˆ’1 h) than the 30 g HC LF (144 Ī¼g Lāˆ’1 h), 0 g HC OM (151 Ī¼g Lāˆ’1 h) and 0 g HC LF (122 Ī¼g Lāˆ’1 h) interventions. Ī²-CTX concentration decreased 1.4-fold from pre-RE to 6 h post-RE in all interventions. Thus, high circulating oestrogen concentration was associated with lower collagen synthesis following RE in this female athlete. Ingesting 30 g HC, however, augmented the collagen synthesis response at LF and particularly at OM. Highlights: What is the central question of this study? Does resistance exercise-induced collagen synthesis vary according to circulating oestrogen concentration in a naturally menstruating female athlete, and if so, does hydrolysed collagen ingestion have any impact? What is the main finding and its importance? Exercise-induced collagen synthesis was low when circulating oestrogen concentration was high and vice versa. However, ingesting 30 g hydrolysed collagen prior to exercise reduced the negative effect of oestrogen on collagen synthesis. As high circulating oestrogen has been associated with greater injury risk in females, supplementing exercise with hydrolysed collagen may help protect these tissues from injury

    Cell-Free Synthesis of the Mitochondrial ADP/ATP Carrier Protein of Neurospora crassa

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    ADP/ATP carrier protein was synthesized in heterologous cell-free systems programmed with Neurospora poly(A)-containing RNA and homologous cell-free systems from Neurospora. The apparent molecular weight of the product obtained in vitro was the same as that of the authentic mitochondrial protein. The primary translation product obtained in reticulocyte lysates starts with formylmethionine when formylated initiator methionyl-tRNA (fMet-tRNAfMet) was present. The product synthesized in vitro was released from the ribosomes into the postribosomal supernatant. The evidence presented indicates that the ADP/ATP carrier is synthesized as a polypeptide with the same molecular weight as the mature monomeric protein and does not carry an additional sequence

    11 beta-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle

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    OBJECTIVE: Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11beta-HSD1 inhibitors improve insulin sensitivity. \ud RESEARCH DESIGN AND METHODS: Rodent and human cell cultures, whole-tissue explants, and animal models were used to determine the impact of glucocorticoids and selective 11beta-HSD1 inhibition upon insulin signaling and action. \ud RESULTS: Dexamethasone decreased insulin-stimulated glucose uptake, decreased IRS1 mRNA and protein expression, and increased inactivating pSer307^{307} insulin receptor substrate (IRS)-1. 11beta-HSD1 activity and expression were observed in human and rodent myotubes and muscle explants. Activity was predominantly oxo-reductase, generating active glucocorticoid. A1 (selective 11beta-HSD1 inhibitor) abolished enzyme activity and blocked the increase in pSer307^{307} IRS1 and reduction in total IRS1 protein after treatment with 11DHC but not corticosterone. In C57Bl6/J mice, the selective 11beta-HSD1 inhibitor, A2, decreased fasting blood glucose levels and improved insulin sensitivity. In KK mice treated with A2, skeletal muscle pSer307^{307} IRS1 decreased and pThr308^{308} Akt/PKB increased. In addition, A2 decreased both lipogenic and lipolytic gene expression.\ud CONCLUSIONS: Prereceptor facilitation of glucocorticoid action via 11beta-HSD1 increases pSer307^{307} IRS1 and may be crucial in mediating insulin resistance in skeletal muscle. Selective 11beta-HSD1 inhibition decreases pSer307^{307} IRS1, increases pThr308^{308} Akt/PKB, and decreases lipogenic and lipolytic gene expression that may represent an important mechanism underpinning their insulin-sensitizing action

    Outlook and appraisal [March 1993]

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    The end of the recession is at hand, but the size and timing of proposed tax increases may limit the speed of recovery and so reduce further the prospects for the three million unemployed in Britain
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