174 research outputs found
Progress in Understanding and Treating SCN2A-Mediated Disorders
Advances in gene discovery for neurodevelopmental disorders have identified SCN2A dysfunction as a leading cause of infantile seizures, autism spectrum disorder, and intellectual disability. SCN2A encodes the neuronal sodium channel NaV1.2. Functional assays demonstrate strong correlation between genotype and phenotype. This insight can help guide therapeutic decisions and raises the possibility that ligands that selectively enhance or diminish channel function may improve symptoms. The well-defined function of sodium channels makes SCN2A an important test case for investigating the neurobiology of neurodevelopmental disorders more generally. Here, we discuss the progress made, through the concerted efforts of a diverse group of academic and industry scientists as well as policy advocates, in understanding and treating SCN2A-related disorders
Center of mass, spin supplementary conditions, and the momentum of spinning particles
We discuss the problem of defining the center of mass in general relativity
and the so-called spin supplementary condition. The different spin conditions
in the literature, their physical significance, and the momentum-velocity
relation for each of them are analyzed in depth. The reason for the
non-parallelism between the velocity and the momentum, and the concept of
"hidden momentum", are dissected. It is argued that the different solutions
allowed by the different spin conditions are equally valid descriptions for the
motion of a given test body, and their equivalence is shown to dipole order in
curved spacetime. These different descriptions are compared in simple examples.Comment: 45 pages, 7 figures. Some minor improvements, typos fixed, signs in
some expressions corrected. Matches the published version. Published as part
of the book "Equations of Motion in Relativistic Gravity", D. Puetzfeld et
al. (eds.), Fundamental Theories of Physics 179, Springer, 201
Quantitative imaging of concentrated suspensions under flow
We review recent advances in imaging the flow of concentrated suspensions,
focussing on the use of confocal microscopy to obtain time-resolved information
on the single-particle level in these systems. After motivating the need for
quantitative (confocal) imaging in suspension rheology, we briefly describe the
particles, sample environments, microscopy tools and analysis algorithms needed
to perform this kind of experiments. The second part of the review focusses on
microscopic aspects of the flow of concentrated model hard-sphere-like
suspensions, and the relation to non-linear rheological phenomena such as
yielding, shear localization, wall slip and shear-induced ordering. Both
Brownian and non-Brownian systems will be described. We show how quantitative
imaging can improve our understanding of the connection between microscopic
dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of
methodology. Submitted for special volume 'High Solid Dispersions' ed. M.
Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009);
22 pages, 16 fig
Hyperinsulinaemia as long-term predictor of death and ischaemic heart disease in nondiabetic men: The Malmö Preventive Project.
Objectives. Prospective studies have indicated that hyperinsulinaemia/insulin resistance is a risk factor for ischaemic heart disease (IHD), the risk decreasing with time of follow-up. Few studies have so far investigated the role of hyperinsulinaemia in the prediction of long-term total mortality. Setting. Section of Preventive Medicine, Department of Medicine, University Hospital, Malmö, Sweden. Subjects. A total of 6074 nondiabetic, middle-aged, healthy Swedish males. Screening examination. We determined IHD risk factors including blood glucose and plasma insulin before and 2 h after an oral glucose tolerance test (OGTT). Total follow-up time was 19 years. Hyperinsulinaemia was defined as values above the 10th decentile of fasting or 2 h insulin concentration. Main outcome measures. Total mortality and cardiac event (CE) rate for IHD. Results. Unadjusted relative risks (RRs) for both death and CE were J-shaped with the highest relative risk (RR: 1.4-1.6) in the hyperinsulinaemic group compared with all other men. The RRs for death and CE were significant for fasting insulin but became nonsignificant after adjustment for other risk factors and also with a longer follow-up. The risk of death in hyperinsulinaemic men, defined on the basis of 2-h insulin level, increased with time of follow-up and was still significantly increased after 19 years [RR: 1.32 (95% CI: 1.05-1.65], even after adjustment for other risk factors. Conclusions. Fasting hyperinsulinaemia was a predictor of total mortality and IHD in nondiabetic men, although not more significantly after adjustment for other risk factors and with lengthening of follow-up time. The 2-h postglucose hyperinsulinaemia appeared to be a stronger and independent predictor of mortality over long-term follow-up. These findings support the view that insulin resistance with associated cluster of risk factors predicts increased long-term risk of mortality and IHD
Validation of a registry-derived risk algorithm based on treatment protocol as a proxy for disease risk in childhood acute lymphoblastic leukemia
Effects of immunomodulatory drugs on TNF-α and IL-12 production by purified epidermal langerhans cells and peritoneal macrophages
<p>Abstract</p> <p>Background</p> <p>Langerhans cells constitute a special subset of immature dendritic cells localized in the epidermis that play a key role in the skin's immune response. The production of cytokines is a key event in both the initiation and the regulation of immune responses, and different drugs can be used to remove or modify their production by DC and, therefore, alter immune responses in a broad spectrum of diseases, mainly in human inflammatory and autoimmune diseases. In the present study, we examined the effects of prednisone, thalidomide, cyclosporine A, and amitriptyline, drugs used in a variety of clinical conditions, on the production of TNF-α, IL-10, and IL-12 by purified epidermal Langerhans cells and peritoneal macrophages in BALB/c mice.</p> <p>Findings</p> <p>All drugs inhibited TNF-α production by Langerhans cells after 36 hours of treatment at two different concentrations, while prednisone and thalidomide decreased IL-12 secretion significantly, amitriptyline caused a less pronounced reduction and cyclosporine A had no effect. Additionally, TNF-α and IL-12 production by macrophages decreased, but IL-10 levels were unchanged after all treatments.</p> <p>Conclusions</p> <p>Our results demonstrate that these drugs modulate the immune response by regulating pro-inflammatory cytokine production by purified epidermal Langerhans cells and peritoneal macrophages, indicating that these cells are important targets for immunosuppression in various clinical settings.</p
Understanding emotionally relevant situations in primary care dental practice: 1. Clinical situations and emotional responses
Background and aims. The stressful nature of dental practice is well established. Much less information is available on the coping strategies used by dentists and the emotions which underlie the stressful experience. Previous research has been almost exclusively questionnaire-based, limiting the range of emotions explored. This study used qualitative methods to explore the full extent of emotions and coping strategies associated with stressful events in primary dental practice.
Method. Semi-structured interviews were conducted with 20 dentists in Lincoln and the surrounding area. Verbatim transcriptions were analysed using thematic analysis.
Results. Participants reported a wide variety of stressful situations, consistent with the existing literature, which were associated with a diverse range of negative emotional responses including anxiety, anger and sadness. Dentists tended to have more difficulty identifying positive events and emotions. The designation of a situation as stressful or otherwise was dependent on the dentist's personal interpretation of the event. Data relating to the effects of stressors and the coping strategies used by dentists will be presented in subsequent papers.
Conclusion. The situations which dentists find difficult are accompanied by a diverse set of emotions, rather than omnipresent 'stress.' This has implications for stress management programmes for those in dental practic
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APOE genotype influences insulin resistance, apolipoprotein CII and CIII according to plasma fatty acid profile in the Metabolic Syndrome
Metabolic markers associated with the Metabolic Syndrome (MetS) may be affected by interactions between the APOE genotype and plasma fatty acids (FA). In this study, we explored FA-gene interactions between the missense APOE polymorphisms and FA status on metabolic markers in MetS. Plasma FA, blood pressure, insulin sensitivity and lipid concentrations were determined at baseline and following a 12-week randomized, controlled, parallel, dietary FA intervention in 442 adults with MetS (LIPGENE study). FA-APOE gene interactions at baseline and following change in plasma FA were assessed using adjusted general linear models. At baseline E4 carriers had higher plasma concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (apo B) compared with E2 carriers; and higher TC, LDL-C and apo B compared with E3/E3. Whilst elevated plasma n-3 polyunsaturated FA (PUFA) was associated with a beneficially lower concentration of apo CIII in E2 carriers, a high proportion of plasma C16:0 was associated with insulin resistance in E4 carriers. Following FA intervention, a reduction in plasma long-chain n-3 PUFA was associated with a reduction in apo CII concentration in E2 carriers. Our novel data suggest that individuals with MetS may benefit from personalized dietary interventions based on APOE genotype
Bivariate genome-wide association analysis implicates pleiotropic effects at the SREBF1/TOM1L2 locus on bone mineral density and lean mass in children
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