730 research outputs found

    Sex-specific associations of adiposity with cardiometabolic traits in the UK: A multi-life stage cohort study with repeat metabolomics

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    Background Sex differences in cardiometabolic disease risk are commonly observed across the life course but are poorly understood and may be due to different associations of adiposity with cardiometabolic risk in females and males. We examined whether adiposity is differently associated with cardiometabolic trait levels in females and males at 3 different life stages. Methods and findings Data were from 2 generations (offspring, Generation 1 [G1] born in 1991/1992 and their parents, Generation 0 [G0]) of a United Kingdom population-based birth cohort study, the Avon Longitudinal Study of Parents and Children (ALSPAC). Follow-up continues on the cohort; data up to 25 y after recruitment to the study are included in this analysis. Body mass index (BMI) and total fat mass from dual-energy X-ray absorptiometry (DXA) were measured at mean age 9 y, 15 y, and 18 y in G1. Waist circumference was measured at 9 y and 15 y in G1. Concentrations of 148 cardiometabolic traits quantified using nuclear magnetic resonance spectroscopy were measured at 15 y, 18 y, and 25 y in G1. In G0, all 3 adiposity measures and the same 148 traits were available at 50 y. Using linear regression models, sex-specific associations of adiposity measures at each time point (9 y, 15 y, and 18 y) with cardiometabolic traits 3 to 6 y later were examined in G1. In G0, sex-specific associations of adiposity measures and cardiometabolic traits were examined cross-sectionally at 50 y. A total of 3,081 G1 and 4,887 G0 participants contributed to analyses. BMI was more strongly associated with key atherogenic traits in males compared with females at younger ages (15 y to 25 y), and associations were more similar between the sexes or stronger in females at 50 y, particularly for apolipoprotein B-containing lipoprotein particles and lipid concentrations. For example, a 1 standard deviation (SD) (3.8 kg/m2) higher BMI at 18 y was associated with 0.36 SD (95% confidence interval [CI] = 0.20, 0.52) higher concentrations of extremely large very-low-density lipoprotein (VLDL) particles at 25 y in males compared with 0.15 SD (95% CI = 0.09, 0.21) in females, P value for sex difference = 0.02. By contrast, at 50 y, a 1 SD (4.8 kg/m2) higher BMI was associated with 0.33 SD (95% CI = 0.25, 0.42) and 0.30 SD (95% CI = 0.26, 0.33) higher concentrations of extremely large VLDL particles in males and females, respectively, P value for sex difference = 0.42. Sex-specific associations of DXA-measured fat mass and waist circumference with cardiometabolic traits were similar to findings for BMI and cardiometabolic traits at each age. The main limitation of this work is its observational nature, and replication in independent cohorts using methods that can infer causality is required. Conclusions The results of this study suggest that associations of adiposity with adverse cardiometabolic risk begin earlier in the life course among males compared with females and are stronger until midlife, particularly for key atherogenic lipids. Adolescent and young adult males may therefore be high priority targets for obesity prevention efforts

    An intra-neural microstimulation system for ultra-high field magnetic resonance imaging and magnetoencephalography.

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    BACKGROUND: Intra-neural microstimulation (INMS) is a technique that allows the precise delivery of low-current electrical pulses into human peripheral nerves. Single unit INMS can be used to stimulate individual afferent nerve fibres during microneurography. Combining this with neuroimaging allows the unique monitoring of central nervous system activation in response to unitary, controlled tactile input, with functional magnetic resonance imaging (fMRI) providing exquisite spatial localisation of brain activity and magnetoencephalography (MEG) high temporal resolution. NEW METHOD: INMS systems suitable for use within electrophysiology laboratories have been available for many years. We describe an INMS system specifically designed to provide compatibility with both ultra-high field (7T) fMRI and MEG. Numerous technical and safety issues are addressed. The system is fully analogue, allowing for arbitrary frequency and amplitude INMS stimulation. RESULTS: Unitary recordings obtained within both the MRI and MEG screened-room environments are comparable with those obtained in 'clean' electrophysiology recording environments. Single unit INMS (current <7μA, 200μs pulses) of individual mechanoreceptive afferents produces appropriate and robust responses during fMRI and MEG. COMPARISON WITH EXISTING METHOD(S): This custom-built MRI- and MEG-compatible stimulator overcomes issues with existing INMS approaches; it allows well-controlled switching between recording and stimulus mode, prevents electrical shocks because of long cable lengths, permits unlimited patterns of stimulation, and provides a system with improved work-flow and participant comfort. CONCLUSIONS: We demonstrate that the requirements for an INMS-integrated system, which can be used with both fMRI and MEG imaging systems, have been fully met

    Influence of inflammatory polyarthritis on quantitative heel ultrasound measurements.

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    BACKGROUND: There are few data concerning the impact of inflammatory polyarthritis (IP) on quantitative heel ultrasound (QUS) measurements. The aims of this analysis were i) to determine the influence of IP on QUS measurements at the heel and, ii) among those with IP to determine the influence of disease related factors on these measurements. METHODS: Men and women aged 16 years and over with recent onset IP were recruited to the Norfolk Arthritis Register (NOAR). Individuals with an onset of joint symptoms between 1989 and 1999 were included in this analysis. At the baseline visit subjects underwent a standardised interview and clinical examination with blood taken for rheumatoid factor. A population-based prospective study of chronic disease (EPIC-Norfolk) independently recruited men and women aged 40 to 79 years from the same geographic area between 1993 and 1997. At a follow up assessment between 1998 and 2000 subjects in EPIC-Norfolk were invited to have quantitative ultrasound measurements of the heel (CUBA-Clinical) performed. We compared speed of sound (SOS) and broadband ultrasound attenuation (BUA), in those subjects recruited to NOAR who had ultrasound measurements performed (as part of EPIC-Norfolk) subsequent to the onset of joint symptoms with a group of age and sex matched non-IP controls who had participated in EPIC-Norfolk. Fixed effect linear regression was used to explore the influence of IP on the heel ultrasound parameters (SOS and BUA) so the association could be quantified as the mean difference in BUA and SOS between cases and controls. In those with IP, linear regression was used to examine the association between these parameters and disease related factors. RESULTS: 139 men and women with IP and 278 controls (mean age 63.2 years) were studied. Among those with IP, mean BUA was 76.3 dB/MHz and SOS 1621.8 m/s. SOS was lower among those with IP than the controls (difference = -10.0; 95% confidence interval (CI) -17.4, -2.6) though BUA was similar (difference = -1.2; 95% CI -4.5, +2.1). The difference in SOS persisted after adjusting for body mass index and steroid use. Among those with IP, disease activity as determined by the number of swollen joints at baseline, was associated with a lower SOS. In addition SOS was lower in the subgroup that satisfied the 1987 ACR criteria. By contrast, disease duration, steroid use and HAQ score were not associated with either BUA or SOS. CONCLUSIONS: In this general population derived cohort of individuals with inflammatory polyarthritis there is evidence from ultrasound of a potentially adverse effect on the skeleton. The effect appears more marked in those with active disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Altered SMRT levels disrupt vitamin D3 receptor signalling in prostate cancer cells.

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    We hypothesized that key antiproliferative target genes for the vitamin D receptor (VDR) were repressed by an epigenetic mechanism in prostate cancer cells resulting in apparent hormonal insensitivity. To explore this possibility, we examined nuclear receptor corepressor expression in a panel of nonmalignant and malignant cell lines and primary cultures, and found frequently elevated SMRT corepressor mRNA expression often associated with reduced sensitivity to 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)2D3). For example, PC-3 and DU-145 prostate cancer cell lines had 1.8-fold and twofold increases in SMRT mRNA relative to normal PrEC cells (P<0.05). Similarly, 10/15 primary tumour cultures (including three matched to normal cells from the same donors) had elevated SMRT mRNA levels; generally NCoR1 and Alien were not as commonly elevated. Corepressor proteins often have associated histone deacetylases (HDAC) and reflectively the antiproliferative action of 1alpha,25(OH)2D3 can be restored by cotreatment with low doses of HDAC inhibitors such as trichostatin A (TSA, 15 nM) to induce apoptosis in prostate cancer cell lines. To decipher the transcriptional events that lead to these cellular responses, we undertook gene expression studies in PC-3 cells after cotreatment of 1alpha,25(OH)2D3 plus TSA after 6 h. Examination of known VDR target genes and cDNA microarray analyses revealed cotreatment of 1alpha,25(OH)2D3 plus TSA cooperatively upregulated eight (out of 1176) genes, including MAPK-APK2 and GADD45alpha. MRNA and protein time courses and inhibitor studies confirmed these patterns of regulation. Subsequently, we knocked down SMRT levels in PC-3 cells using a small interfering RNA (siRNA) approach and found that GADD45alpha induction by 1alpha,25(OH)2D3 alone became very significantly enhanced. The same distortion of gene responsiveness, with repressed induction of GADD45alpha was found in primary tumour cultures compared and to matched peripheral zone (normal) cultures from the same donor. These data demonstrate that elevated SMRT levels are common in prostate cancer cells, resulting in suppression of target genes associated with antiproliferative action and apparent 1alpha,25(OH)2D3-insensitivity. This can be targeted therapeutically by combination treatments with HDAC inhibitors

    The pharmaceutical death-ride of dihydroartemisinin

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    In the 2010 second edition of WHO's guidelines for the treatment of malaria, the relatively new fixed dose combination dihydroartemisinin-piperaquine is included as one of the recommended artemisinin combination therapies. However, experimental testing demonstrates that, due to its intrinsic chemical instability, dihydroartemisinin is not suitable to be used in pharmaceutical formulations. In addition, data show that the currently available dihydroartemisinin preparations fail to meet the internationally accepted stability requirements. At a time when many efforts aim to ban counterfeit and substandard drugs from the malaria market, the obvious question rises how WHO and public-private partnerships, such as Medicine for Malaria venture (MMV), can support the production and marketing of anti-malarial drugs that do not even meet the International Pharmacopoeia requirements

    Molecular Mechanism of Action of Antimalarial Benzoisothiazolones: Species-Selective Inhibitors of the Plasmodium spp. MEP Pathway enzyme, IspD

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    The methylerythritol phosphate (MEP) pathway is an essential metabolic pathway found in malaria parasites, but absent in mammals, making it a highly attractive target for the discovery of novel and selective antimalarial therapies. Using high-throughput screening, we have identified 2-phenyl benzo[d]isothiazol-3(2H)-ones as species-selective inhibitors of Plasmodium spp. 2-C-methyl-D-erythritol-4-phosphate cytidyltransferase (IspD), the third catalytic enzyme of the MEP pathway. 2-Phenyl benzo[d]isothiazol-3(2H)-ones display nanomolar inhibitory activity against P. falciparum and P. vivax IspD and prevent the growth of P. falciparum in culture, with EC50 values below 400 nM. In silico modeling, along with enzymatic, genetic and crystallographic studies, have established a mechanism-of-action involving initial non-covalent recognition of inhibitors at the IspD binding site, followed by disulfide bond formation through attack of an active site cysteine residue on the benzo[d]isothiazol-3(2H)-one core. The species-selective inhibitory activity of these small molecules against Plasmodium spp. IspD and cultured parasites suggests they have potential as lead compounds in the pursuit of novel drugs to treat malaria

    Implementation of personalised medicine policies in mental healthcare: results from a stated preference study in the UK

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    Background Public support for the implementation of personalised medicine policies (PMPs) within routine care is important owing to the high financial costs involved and the potential for redirection of resources from other services. Aims We aimed to determine the attributes of a PMP most likely to elicit public support for implementation. We also aimed to determine whether such support differed between a depression PMP and one for cystic fibrosis. Method In a discrete-choice experiment, paired vignettes illustrating both the current model of care (CMoC) and a hypothetical PMP for either depression or cystic fibrosis were presented to a representative sample of the UK public (n = 2804). Each vignette integrated varying attributes, including anticipated therapeutic benefit over CMoC, and the annual cost to the taxpayer. Respondents were invited to express their preference for either the PMP or CMoC within each pair. Results The financial cost was the most important attribute influencing public support for PMPs. Respondents favoured PMP implementation where it benefited a higher proportion of patients or was anticipated to be more effective than CMoC. A reduction in services for non-eligible patients reduced the likelihood of support for PMPs. Respondents were more willing to fund PMPs for cystic fibrosis than for depression. Conclusions Cost is a significant factor in the public's support for PMPs, but essential caveats, such as protection for services available to PMP-ineligible patients, may also apply. Further research should explore the factors contributing to condition-specific nuances in public support for PMPs

    Influence of arthritis and non-arthritis related factors on areal bone mineral density (BMDa) in women with longstanding inflammatory polyarthritis: a primary care based inception cohort

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    <p>Abstract</p> <p>Background</p> <p>The aim of this analysis was to determine the relative influence of disease and non-disease factors on areal bone mineral density (BMD<sub>a</sub>) in a primary care based cohort of women with inflammatory polyarthritis.</p> <p>Methods</p> <p>Women aged 16 years and over with recent onset inflammatory polyarthritis were recruited to the Norfolk Arthritis Register (NOAR) between 1990 and 1993. Subjects were examined at both baseline and follow up for the presence of tender, swollen and deformed joints. At the 10<sup>th </sup>anniversary visit, a sub-sample of women were invited to complete a bone health questionnaire and attend for BMD<sub>a </sub>(Hologic, QDR 4000). Linear regression was used to examine the association between BMD<sub>a </sub>with both (i) arthritis-related factors assessed at baseline and the 10<sup>th </sup>anniversary visit and (ii) standard risk factors for osteoporosis. Adjustments were made for age.</p> <p>Results</p> <p>108 women, mean age 58.0 years were studied. Older age, decreasing weight and BMI at follow up were all associated with lower BMD<sub>a </sub>at both the spine and femoral neck. None of the lifestyle factors were linked. Indices of joint damage including 10<sup>th </sup>anniversary deformed joint count and erosive joint count were the arthritis-related variables linked with a reduction in BMD<sub>a </sub>at the femoral neck. By contrast, disease activity as determined by the number of tender and or swollen joints assessed both at baseline and follow up was not linked with BMD<sub>a </sub>at either site.</p> <p>Conclusion</p> <p>Cumulative disease damage was the strongest predictor of reduced femoral bone density. Other disease and lifestyle factors have only a modest influence.</p

    Simulation of an SEIR infectious disease model on the dynamic contact network of conference attendees

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    The spread of infectious diseases crucially depends on the pattern of contacts among individuals. Knowledge of these patterns is thus essential to inform models and computational efforts. Few empirical studies are however available that provide estimates of the number and duration of contacts among social groups. Moreover, their space and time resolution are limited, so that data is not explicit at the person-to-person level, and the dynamical aspect of the contacts is disregarded. Here, we want to assess the role of data-driven dynamic contact patterns among individuals, and in particular of their temporal aspects, in shaping the spread of a simulated epidemic in the population. We consider high resolution data of face-to-face interactions between the attendees of a conference, obtained from the deployment of an infrastructure based on Radio Frequency Identification (RFID) devices that assess mutual face-to-face proximity. The spread of epidemics along these interactions is simulated through an SEIR model, using both the dynamical network of contacts defined by the collected data, and two aggregated versions of such network, in order to assess the role of the data temporal aspects. We show that, on the timescales considered, an aggregated network taking into account the daily duration of contacts is a good approximation to the full resolution network, whereas a homogeneous representation which retains only the topology of the contact network fails in reproducing the size of the epidemic. These results have important implications in understanding the level of detail needed to correctly inform computational models for the study and management of real epidemics

    Sternalis muscle: an underestimated anterior chest wall anatomical variant

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    Over the recent years, an increased alertness for thorough knowledge of anatomical variants with clinical significance has been recorded in order to minimize the risks of surgical complications. We report a rare case of bilateral strap-like sternalis muscle of the anterior chest wall in a female cadaver. Its presence may evoke alterations in the electrocardiogram or confuse a routine mammography. The incidental finding of a sternalis muscle in mammography, CT, and MRI studies must be documented in a patient's medical records as it can be used as a pedicle flap or flap microvascular anastomosis during reconstructive surgery of the anterior chest wall, head and neck, and breast. Moreover, its presence may be misdiagnosed as a wide range of benign and malignant anterior chest wall lesions and tumors
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