394 research outputs found
An end-to-end framework for real-time automatic sleep stage classification.
Sleep staging is a fundamental but time consuming process in any sleep laboratory. To greatly speed up sleep staging without compromising accuracy, we developed a novel framework for performing real-time automatic sleep stage classification. The client-server architecture adopted here provides an end-to-end solution for anonymizing and efficiently transporting polysomnography data from the client to the server and for receiving sleep stages in an interoperable fashion. The framework intelligently partitions the sleep staging task between the client and server in a way that multiple low-end clients can work with one server, and can be deployed both locally as well as over the cloud. The framework was tested on four datasets comprising ≈1700 polysomnography records (≈12000 hr of recordings) collected from adolescents, young, and old adults, involving healthy persons as well as those with medical conditions. We used two independent validation datasets: one comprising patients from a sleep disorders clinic and the other incorporating patients with Parkinson's disease. Using this system, an entire night's sleep was staged with an accuracy on par with expert human scorers but much faster (≈5 s compared with 30-60 min). To illustrate the utility of such real-time sleep staging, we used it to facilitate the automatic delivery of acoustic stimuli at targeted phase of slow-sleep oscillations to enhance slow-wave sleep
Transcatter X-Ray Technique for the Inspection of Insulated, Oil-Carrying Pipelines
Pipelines are subjected to corrosion and require periodic inspection. These pipes are generally covered with an insulating material, that is contained within a metal jacket. The removal of the insulating material is costly, and can hazardous if asbestos is the material being removed. Because a large number of pipes need to be inspected, a cost effective technique for the characterization of corrosion under insulation is desirable
CFTR founder mutation causes protein trafficking defects in Chinese patients with cystic fibrosis
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Associations between a fetal imprinted gene allele score and late pregnancy maternal glucose concentrations
We hypothesised that some of the genetic risk for gestational diabetes (GDM) is due to the fetal genome affecting maternal glucose concentrations. Previously, we found associations between fetal IGF2 gene variants and maternal glucose concentrations in late pregnancy.
In the present study, we tested associations between SNP alleles from 15 fetal imprinted genes and maternal glucose concentrations in late pregnancy in the Cambridge Baby Growth and Wellbeing cohorts (1160 DNA trios).
Four fetal SNP alleles with the strongest univariate associations: paternally-transmitted IGF2 rs10770125 (P-value = 2 × 10) and INS rs2585 (P-value = 7 × 10), and maternally-transmitted KCNQ1(OT1) rs231841 (P-value = 1 × 10) and KCNQ1(OT1) rs7929804 (P-value = 4 × 10), were used to construct a composite fetal imprinted gene allele score which was associated with maternal glucose concentrations (P-value = 4.3 × 10, n = 981, r = 2.0%) and GDM prevalence (odds ratio per allele 1.44 (1.15, 1.80), P-value = 1 × 10, n = 89 cases and 899 controls). Meta-analysis of the associations including data from 1367 Hyperglycaemia and Adverse Pregnancy Outcome Study participants confirmed the paternally-transmitted fetal IGF2/INS SNP associations (rs10770125, P-value = 3.2 × 10, rs2585, P-value = 3.6 × 10) and the composite fetal imprinted gene allele score association (P-value = 1.3 × 10), but not the maternally-transmitted fetal KCNQ1(OT1) associations (rs231841, P-value = 0.4; rs7929804, P-value = 0.2).
This study suggests that polymorphic variation in fetal imprinted genes, particularly in the IGF2/INS region, contribute a small but significant part to the risk of raised late pregnancy maternal glucose concentrations.This work was supported by the Evelyn Trust (grant number EW9035322); Diabetes UK (grant number 11/0004241); the Wellbeing of Women (the Royal College of Obstetricians and Gynaecologists, UK) (grant number RG1644); the Medical Research Council (grant number 7500001180); European Union Framework 5 (grant number QLK4-1999-01422); the Mothercare Charitable Foundation (grant number RG54608); Newlife Foundation for Disabled Children (grant number 07/20); the World Cancer Research Fund International (grant number 2004/03); and the National Institute for Health Research Cambridge Biomedical Research Centre. The HAPO Study work was supported by the National Institutes of Health (grant numbers HD-34242, HD-34243, HG-004415, and CA-141688); the Institutes of Health Research–INMD (grant number 110791); and by the American Diabetes Association
Hepatocyte-intrinsic SMN deficiency drives metabolic dysfunction and liver steatosis in spinal muscular atrophy
This work was supported by an Agency for Science, Technology and Research (A*STAR) CDF grant number C210112024 (to CJJY). Acknowledgments to Dave Wee, Edward Manser, Frederick Bard, and Uttam Surana from A*STAR for scientific discussions and to Shaye Moore from Boston Children’s Hospital for assistance with editing and submission.Peer reviewe
Image-guided versus blind corticosteroid injections in adults with shoulder pain: A systematic review
<p>Abstract</p> <p>Background</p> <p>Corticosteroid injections can be performed blind (landmark-guided) or with image guidance, and this may account for variable clinical outcomes. The objective of this study was to assess the effectiveness and safety of image-guided versus blind corticosteroid injections in improving pain and function among adults with shoulder pain.</p> <p>Methods</p> <p>MEDLINE, the Cochrane Controlled Trials Register and EMBASE were searched to May 2010. Additional studies were identified by searching bibliographies of shortlisted articles. Search items included blind, landmark, anatomical, clinical exam, image-guided, ultrasound, fluoroscopy, steroid injection, frozen shoulder, random allocation, randomized controlled trial (RCT) and clinical trial.</p> <p>Randomized controlled studies comparing image-guided versus blind (landmark-guided) corticosteroid shoulder injections that examined pain, function and/or adverse events were included. Independent extraction was done by two authors using a form with pre-specified data fields, including risk of bias appraisal. Conflicts were resolved by discussion. The decision to pool data was based on assessment of clinical design homogeneity. When warranted, studies were pooled under a random-effects model.</p> <p>Results</p> <p>Two RCTs for pain, function and adverse events (n = 101) met eligibility criteria. No serious threats to validity were found. Both trials compared ultrasound-guided versus landmark-guided injections and were judged similar in clinical design. Low to moderate heterogeneity was observed: shoulder pain I<sup>2 </sup>= 60%, function I<sup>2 </sup>= 22%. A meta-analysis demonstrated greater improvement with ultrasound-guided injections at 6 weeks after injection in both pain (mean difference = 2.23 [95% CI: 1.27, 3.18]), as assessed with a 0 to 10 visual analogue scale, and shoulder function (standardised mean difference = 1.09 [95% CI: 0.61, 1.57]) as assessed with shoulder function scores. Although more adverse events (all mild) were reported with landmark-guided injections, the difference was not statistically significant (risk ratio = 0.20 [95% CI: 0.04, 1.13]).</p> <p>This review was only based on two moderate-sized trials. Blinding of patients was not performed in both trials, causing some risk of bias in outcome assessment since primary endpoints were wholly or partially patient-reported.</p> <p>Conclusion</p> <p>There is a paucity of RCTs on image-guided versus landmark-guided corticosteroid shoulder injections examining pain, function and adverse events. In this review, patients who underwent image-guided (ultrasound) injections had statistically significant greater improvement in shoulder pain and function at 6 weeks after injection. Image-guided (ultrasound) corticosteroid injections potentially offer a significantly greater clinical improvement over blind (landmark-guided) injections in adults with shoulder pain. However, this apparent benefit requires confirmation from further studies (adequately-powered and well-executed RCTs).</p
IAP Display: A Simple Method to Identify Mouse Strain Specific IAP Insertions
Intracisternal A-type particle (IAP) elements are high copy number long terminal repeat (LTR) rodent retrotransposons. Some IAP elements can transpose, and are responsible for ~12% of spontaneous mouse mutations. Inbred mouse strains show variation in genomic IAP distribution, contributing to inter-strain genetic variability. Additionally IAP elements can influence the transcriptional regulation of neighbouring genes through their strong LTR promoter, effecting phenotypic variation. This genetic and phenotypic variability can translate into experimental variability between mouse strains. For example, it has been demonstrated that strain-specific genetic/epigenetic factors can interact to yield variable responses to drugs. Therefore, in experimental contexts it is essential to unequivocally identify mouse strains. Recently it was estimated that any two inbred strains share only ~40% of their IAP insertions. Of the remaining 60%, some insertions will be strain specific, fixed during inbreeding. These fixed insertions can be exploited as genetic markers to identify inbred strains, if they can be identified simply and efficiently. Here, we report the development of a PCR-based system allowing direct acquisition of strain-specific IAP insertions. In a pilot study, we identified 21 IAP loci, genotyped IAP insertions at 9 loci, and discovered two strain-specific insertions that could reliably identify these strains
Assessment of HIF-1α expression and release following endothelial injury in-vitro and in-vivo
Background: Endothelial injury is an early and enduring feature of cardiovascular disease. Inflammation and hypoxia may be responsible for this, and are often associated with the up-regulation of several transcriptional factors that include Hypoxia Inducible Factor-1 (HIF-1). Although it has been reported that HIF-1α is detectable in plasma, it is known to be unstable. Our aim was to optimize an assay for HIF-1α to be applied to in vitro and in vivo applications, and to use this assay to assess the release kinetics of HIF-1 following endothelial injury.
Methods: An ELISA for the measurement of HIF in cell-culture medium and plasma was optimized, and the assay used to determine the best conditions for sample collection and storage. The results of the ELISA were validated using Western blotting and immunohistochemistry (IHC). In vitro, a standardized injury was produced in a monolayer of rat aortic endothelial cells (RAECs) and intracellular HIF-1α was measured at intervals over 24 hours. In vivo, a rat angioplasty model was used. The right carotid artery was injured using a 2F Fogarty balloon catheter. HIF-1α was measured in the plasma and in the arterial tissue (0, 1, 2, 3 and 5 days post injury).
Results: The HIF-1α ELISA had a limit of detection of 2.7 pg/ mL and was linear up to 1000 pg/ mL. Between and within-assay coefficient of variation values were less than 15%. HIF-1α was unstable in cell lysates and plasma, and it was necessary to add a protease inhibitor immediately after collection, and to store samples at -800C prior to analysis. The dynamics of HIF-1α release were different for the in vitro and in vivo models. In vitro, HIF-1α reached maximum concentrations approximately 2h post injury, whereas peak values in plasma and tissues occurred approximately 2 days post injury, in the balloon injury model.
Conclusion: HIF-1α can be measured in plasma, but this requires careful sample collection and storage. The carotid artery balloon injury model is associated with the transient release of HIF-1α into the circulation that probably reflects the hypoxia induced in the artery wall
Oxygen Tension Modulates Neurite Outgrowth in PC12 Cells Through A Mechanism Involving HIF and VEGF
Cell-based approaches are a promising therapeutic strategy for treating injuries to the nervous system, but the optimal means to promote neurite extension and direct cellular behavior are unclear. Previous studies have examined the behavior of neural-like cells in ambient air (21% oxygen tension), yet these conditions are not representative of the physiological oxygen microenvironment of neural tissues. We hypothesized that neuronal differentiation of a model neural cell line (PC12) could be controlled by modulating local oxygen tension. Compared to ambient conditions, PC12 cells cultured in reduced oxygen exhibited significant increases in neurite extension and total neurite length, with 4% oxygen yielding the highest levels of both indicators. We confirmed neurite extension was mediated through oxygen-responsive mechanisms using small molecules that promote or inhibit HIF-1α stabilization. The hypoxic target gene Vegf was implicated as a neurotrophic factor, as neurite formation at 21% oxygen was mimicked with exogenous VEGF, and a VEGF-neutralizing antibody attenuated neurite formation under reduced oxygen conditions. These findings demonstrate that behavior of neural-like cells is driven by the oxygen microenvironment via VEGF function, and suggest promising approaches for future applications in neural repair
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