Publications by authors named "David Thomson"

A new series of ligands for the glucocorticoid receptor (GR) is described. SAR development was guided by docking 3 into the GR active site and optimizing an unsubstituted phenyl ring for key interactions found in the steroid A-ring binding pocket. To identify compounds with an improved side effect profile over marketed steroids the functional activity of compounds was evaluated in cell based assays for transactivation (aromatase) and transrepression (IL-6).

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We have recently reported the discovery of a novel class of glucocorticoid receptor (GR) antagonists, exemplified by 3, containing a 1,2-dihydroquinoline molecular scaffold. Further SAR studies of these antagonists uncovered chemical modifications conveying agonist functional activity to this series. These agonists exhibit good GR binding affinity and are selective against other nuclear hormone receptors.

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AMP-activated protein kinase (AMPK) is an energy sensing/signaling protein that, when activated, increases ATP production by stimulating glucose uptake and fatty acid oxidation while at the same time inhibiting ATP = consuming processes such as protein synthesis. Chronic activation of AMPK inhibits expression of lipogenic enzymes in the liver and enhances expression of mitochondrial oxidative enzymes in skeletal muscle. Deficiency of muscle LKB1, the upstream kinase of AMPK, results in greater fluctuation in energy charge during muscle contraction and decreased capacity for exercise at higher work rates.

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The glucocorticoid receptor (GR) is involved in the transcriptional regulation of genes associated with inflammation, glucose homeostasis, and bone turnover through the association with ligands, such as corticosteroids. GR-mediated gene transcription is regulated or fine-tuned via the recruitment of co-factors including coactivators and corepressors. Current therapeutic approaches to targeting GR aim to retain the beneficial anti-inflammatory activity of the corticosteroids while eliminating negative side effects.

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The synthesis and in vitro activities of a series of succinyl-nitrile-based inhibitors of Cathepsin S are described. Several members of this class show nanomolar inhibition of the target enzyme as well as cellular potency. The inhibitors displaying the greatest potency contain N-alkyl substituted piperidine and pyrrolidine rings spiro-fused to the alpha-carbon of the P1 residue.

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A 76-year-old man was admitted to the acute medical take with a long history of tiredness. He described slowed thinking, constipation, aching thighs, dry skin, a hoarse voice, hair loss and 10 kilograms of unintentional weight loss. He had lived in Spain for 7 years and his daughter had persuaded him to return to the UK for a medical check-up.

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We report on the nuclear receptor binding affinities, cellular activities of transrepression and transactivation, and anti-inflammatory properties of a quinol-4-one and other A-ring mimetic containing nonsteroidal class of glucocorticoid agonists.

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Alpha-methyltryptamine sulfonamides were identified as human glucocorticoid receptor (hGR) ligands in an ultra high throughput screening (UHTS) campaign. Described will be the hit-to-lead activities, including parallel and single point analog synthesis to map the scaffold. Ligands were identified that exhibited 30 nM binding to hGR.

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What are the molecular signals induced by muscle contraction that result in an increase in GLUT4, hexokinase 2, mitochondrial oxidative enzymes, and other adaptations to endurance exercise training? Could repetitive activation of AMP-activated protein kinase (AMPK) be responsible in part? There is substantial evidence for a role of AMPK in inducing adaptations to endurance training: 1) AMPK is activated in response to muscle contraction; 2) chronic chemical activation of AMPK results in increases in GLUT4, hexokinase 2, UCP-3, and citric acid cycle enzymes; 3) muscle contraction and chemical activation of AMPK both result in increases in PGC-1alpha, a transcriptional coactivator involved in stimulation of mitochondrial biogenesis; and 4) increases in muscle PGC-1 alpha, delta-aminolevulinic acid synthetase, and mitochondrial DNA induced by chronic creatine phosphate depletion in wild-type mice are not observed in dominant-negative AMPK mice. These observations lend credence to the hypothesis that AMPK activation induced by muscle contraction is responsible in part for adaptations to endurance exercise training.

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Spectra and coherences are standard measures of association within and between time series. These measures have several advantages over their time-domain counterparts, not the least of which is the ability to derive and estimate confidence intervals. However, comparing spectra and coherences between two groups of observation is a problem that has not received much attention.

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Multitaper methods for a scan-free spectrum estimation that uses a rotational shear interferometer are investigated. Before source spectra can be estimated the sources must be detected. A source detection algorithm based upon the multitaper F-test is proposed.

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Impaired overload-induced protein synthesis and growth in aged fast-twitch skeletal muscle may result from diminished responsiveness of signalling intermediates controlling protein translation. Yet, potential age-related signalling decrements have never been examined in direct parallel with impaired overload-induced muscle growth in any model. To this end, we used Western blotting to examine the contents and phosphorylation states of mammalian target of rapamycin (mTOR) and its downstream translational signalling intermediates, 70 kDa ribosomal protein S6 kinase (S6k), ribosomal protein S6 (rpS6), eukaryotic elongation factor 2 (eEF2), and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), in conjunction with impaired growth in 1 week overloaded fast-twitch plantaris muscles (via unilateral gastrocnemius ablation) of old (O; 30 months) versus young adult (YA; 8 months) male Fischer344 x Brown Norway rats.

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The purpose of this study was to determine whether the incidence of influenza in Ontario, Canada has decreased following the introduction of the Universal Influenza Immunization Campaign (UIIC) in 2000. All laboratory-confirmed influenza cases in Ontario, from January 1990 to August 2005 were analyzed using multitaper time series analysis. We found that there has not been a decrease in the mean monthly influenza rate following the introduction of the UIIC (109.

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We report the discovery of a novel class of glucocorticoid receptor (GR) ligands based on 1,2-dihydroquinoline molecular scaffold. The compounds exhibit good GR binding affinity and selectivity profile against other nuclear hormone receptors.

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Eighteen Caucasian (white, Middle East and Asian) children diagnosed by paediatric rheumatologists in the UK and France as having systemic juvenile idiopathic arthritis (sJIA) were enrolled in this open label, single dose trial. All patients had evidence of continued symptoms and disease activity for at least three months while receiving >0.2 mg/kg/day of prednisolone, or its equivalent, prior to recruitment.

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An asymmetric route was developed for the synthesis of a class of novel glucocorticoid receptor ligand derivatives 1. The key step of this synthesis involves a diastereoselective addition of chiral sulfoxide anion to a trifluoromethyl ketone precursor. The resulting diastereomers are readily separable and can be converted to the corresponding chiral epoxide and chiral alkyne intermediates (2 and 3).

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Compound 1, a potent glucocorticoid receptor ligand, contains a quaternary carbon bearing trifluoromethyl and hydroxyl groups. This paper describes the effect of replacing the trifluoromethyl group on binding and agonist activity of the GR ligand 1. The results illustrate that replacing the CF3 group with a cyclohexylmethyl or benzyl group maintains the GR binding potency.

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Skeletal muscle mass declines with age, as does the potential for overload-induced fast-twitch skeletal muscle hypertrophy. Because 5'-AMP-activated protein kinase (AMPK) activity is thought to inhibit skeletal muscle protein synthesis and may therefore modulate muscle mass and hypertrophy, the purpose of this investigation was to examine AMPK phosphorylation status (a marker of AMPK activity) and its potential association with the attenuated overload-induced hypertrophy observed in aged skeletal muscle. One-week overload of fast-twitch plantaris and slow-twitch soleus muscles was achieved in young adult (8 mo; n = 7) and old (30 mo; n = 7) Fischer344 x Brown Norway male rats via unilateral gastrocnemius ablation.

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Latitudinal gradients in population dynamics can arise through regional variation in the deterministic components of the population dynamics and the stochastic factors. Here, we demonstrate an increase with latitude in the contribution of a large-scale climate pattern, the North Atlantic Oscillation (NAO), to the fluctuations in size of populations of two European hole-nesting passerine species. However, this influence of climate induced different latitudinal gradients in the population dynamics of the two species.

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Spring temperatures in temperate regions have increased over the past 20 years and many organisms have responded to this increase by advancing the timing of their growth and reproduction. However, not all populations show an advancement of phenology. Understanding why some populations advance and others do not will give us insight into the possible constraints and selection pressures on the advancement of phenology.

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The specificity of the immune response relies on processing of foreign proteins and presentation of antigenic peptides at the cell surface. Inhibition of antigen presentation, and the subsequent activation of T-cells, should, in theory, modulate the immune response. The cysteine protease Cathepsin S performs a fundamental step in antigen presentation and therefore represents an attractive target for inhibition.

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Based on its roots in military air evacuation, helicopter emergency medical services (HEMS) has always been emphasized as a tool for trauma transportation. Despite much discussion regarding resource allocation for HEMS, a literature search found little recent systematic review of pertinent studies. As HEMS utilization is subject to increased scrutiny in a health care dollar-conscious environment, it was felt that a compendium of available outcomes-related literature could assist those assessing utility of HEMS trauma transport.

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