489 research outputs found

    Heat flow and calculus on metric measure spaces with Ricci curvature bounded below - the compact case

    Get PDF
    We provide a quick overview of various calculus tools and of the main results concerning the heat flow on compact metric measure spaces, with applications to spaces with lower Ricci curvature bounds. Topics include the Hopf-Lax semigroup and the Hamilton-Jacobi equation in metric spaces, a new approach to differentiation and to the theory of Sobolev spaces over metric measure spaces, the equivalence of the L^2-gradient flow of a suitably defined "Dirichlet energy" and the Wasserstein gradient flow of the relative entropy functional, a metric version of Brenier's Theorem, and a new (stronger) definition of Ricci curvature bound from below for metric measure spaces. This new notion is stable w.r.t. measured Gromov-Hausdorff convergence and it is strictly connected with the linearity of the heat flow.Comment: To the memory of Enrico Magenes, whose exemplar life, research and teaching shaped generations of mathematician

    Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery

    Get PDF
    Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug's pharmacology and identify potentially suitable therapeutic populations. The need to use a comprehensive battery of pain models is highlighted by studies whereby only a single pain model, thought to relate to the clinical situation, demonstrates lack of efficacy. No single experimental model can mimic the complex nature of clinical pain. The integrated, multi-modal pain task battery presented here encompasses the electrical stimulation task, pressure stimulation task, cold pressor task, the UVB inflammatory model which includes a thermal task and a paradigm for inhibitory conditioned pain modulation. These human pain models have been tested for predicative validity and reliability both in their own right and in combination, and can be used repeatedly, quickly, in short succession, with minimum burden for the subject and with a modest quantity of equipment. This allows a drug to be fully characterized and profiled for analgesic effect which is especially useful for drugs with a novel or untested mechanism of action. Perioperative Medicine: Efficacy, Safety and Outcom

    Repression of SOX6 transcriptional activity by SUMO modification

    Get PDF
    AbstractSOX6 plays key functions in several developmental processes, including neurogenesis and skeleton formation. In this report, we show that SOX6 is modified in vitro and in vivo by small ubiquitin-related modifier (SUMO) on two distinct sites. Mutation of both sites abolished SOX6 sumoylation and increased SOX6 transcriptional activity. SUMO dependent repression of SOX6 transcription was promoted by UBC9 whereas siRNA to UBC9, cotransfection of inactive UBC9 or a SUMO protease increased SOX6 transcriptional activity. Furthermore, co-expression of SOX6 with SUMO2 results in the appearance of SOX6 in a punctate nuclear pattern that colocalized with promyelocytic leukemia protein, which was partially abolished by mutations in SOX6 sumoylation sites

    What Do “None,” “Mild,” “Moderate,” “Severe,” and “Very Severe” Mean to Patients With Cancer? Content Validity of PRO-CTCAEℱ Response Scales

    Get PDF
    Accurate capture of the symptom experience is essential to gauging efficacy, safety, and tolerability of cancer treatments. The Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE) was developed by the National Cancer Institute to allow direct patient self-reporting of symptomatic adverse events in cancer clinical trials. Its content validity has been established in accordance with recommended practices for novel patient-reported outcome (PRO) instruments

    Demonstration of an anti-hyperalgesic effect of a novel pan-Trk inhibitor PF-06273340 in a battery of human evoked pain models

    Get PDF
    AIMInhibitors of nerve growth factor (NGF) reduce pain in several chronic pain indications. NGF signals through tyrosine kinase receptors of the tropomyosin-related kinase (Trk) family and the unrelated p75 receptor. PF-06273340 is a small molecule inhibitor of Trks A, B and C that reduces pain in nonclinical models, and the present study aimed to investigate the pharmacodynamics of this first-in-class molecule in humans.METHODSA randomized, double-blind, single-dose, placebo- and active-controlled five-period crossover study was conducted in healthy human subjects (NCT02260947). Subjects received five treatments: PF-06273340 50mg, PF-06273340 400 mg, pregabalin 300 mg, ibuprofen 600 mg and placebo. The five primary endpoints were the pain detection threshold for the thermal pain tests and the pain tolerance threshold for the cold pressor, electrical stair and pressure pain tests. The trial had predefined decision rules based on 95% confidence that the PF-06273340 effect was better than that of placebo.RESULTSTwenty subjects entered the study, with 18 completing all five periods. The high dose of PF-06273340 met the decision rules on the ultraviolet (UV) B skin thermal pain endpoint [least squares (LS) mean vs. placebo: 1.13, 95% confidence interval: 0.64–1.61], but not on the other four primary endpoints. The low dose did not meet the decision criteria for any of the five primary endpoints. Pregabalin (cold pressor and electrical stair tests) and ibuprofen (UVB thermal pain) showed significant analgesic effects on expected endpoints.CONCLUSIONSThe study demonstrated, for the first time, the translation of nonclinical effects into man in an inflammatory pain analgesic pharmacodynamic endpoint using a pan-Trk inhibitor.Stemcel biology/Regenerative medicine (incl. bloodtransfusion

    Predicted distribution and burden of podoconiosis in Cameroon

    Get PDF
    Introduction: Understanding the number of cases of podoconiosis, its geographical distribution and the population at risk are crucial to estimating the burden of this disease in endemic countries. We assessed each of these using nationwide data on podoconiosis prevalence in Cameroon. Methods: We analysed data arising from two cross-sectional surveys in Cameroon. The dataset was combined with a suite of environmental and climate data and analysed within a robust statistical framework, which included machine learning-based approaches and geostatistical modelling. The environmental limits, spatial variation of predicted prevalence, population at risk and number of cases of podoconiosis were each estimated. Results: A total of 214,729 records of individuals screened for podoconiosis were gathered from 748 communities in all 10 regions of Cameroon. Of these screened individuals, 882 (0.41%; 95%CI 0.38-0.44) were living with podoconiosis. High environmental suitability for podoconiosis was predicted in three regions of Cameroon (Adamawa, North West and North). The national population living in areas environmentally suitable for podoconiosis was estimated at 5.2 (95% Confidence Interval [CI]: 4.7-5.8) million, which corresponds to 22.3% of Cameroon’s population in 2015. Countrywide, in 2015, the number of adults estimated to be suffering from podoconiosis was 41,556 (95% CI, 1,170- 240,993). Four regions (Central, Littoral, North and North West) contributed 61.2% of the cases. Conclusion: In Cameroon, podoconiosis is more widely distributed geographically than was initially expected. The number of cases and the population at risk are considerable. Expanding morbidity management and follow up of cases is of utmost necessity. Promotion of footwear use and regular foot hygiene should be at the forefront of any intervention plan

    Pharmacokinetics and pharmacodynamics of multiple doses of BG00010, a neurotrophic factor with anti-hyperalgesic effects, in patients with sciatica

    Get PDF
    AIMS: BG00010 is a protein in the glial cell line-derived neurotrophic factor (GDNF) family. It is a selective ligand for the GDNF family receptor alpha-3 (GFRα3) co-receptor that normalizes cellular changes resulting from damage or disease, and potentially alleviates neuropathic pain. The main objectives of this study were to evaluate the pharmacokinetic and safety profiles and to determine the effects on pain of ascending doses of intravenous injections of BG00010 in patients with sciatica.METHODS: This was a randomized, blinded, placebo-controlled multiple-dose study in subjects with sciatica. In Part I (16 patients), four IV dose levels were examined (50, 150, 400, 800 Όg kg(-1) ) and in Part II (12 patients), three dose levels were examined (400, 600 and 1200 Όg kg(-1) ). Safety and efficacy assessments were used as endpoints.RESULTS: The BG00010 concentration-time data indicated relatively low inter-patient variability and there was a dose-dependent (not dose-proportional) increase in serum exposure from 150 to 1200 Όg kg(-1) . The effective half-life was between 40 and 60 h. The most frequently occurring adverse events (AEs) reported by patients receiving BG00010 were headache (67-83%), feeling hot (50-100%), and pruritus (42-67%). Most AEs were mild; no serious AEs or AEs leading to discontinuation occurred. Higher dose regimens of BG00010 resulted in greater pain reduction than placebo or lower dose regimens, although a clear dose-response relationship was not seen.CONCLUSIONS: The pharmacokinetic profile of BG00010 was characterized by low intra-patient variability. These data from a small sample suggest that BG00010 may have a benefit for patients with sciatica.TRIAL REGISTRATION: ClinicalTrials.gov NCT00961766 NCT01405833.Perioperative Medicine: Efficacy, Safety and Outcom

    Nucleation of a sodium droplet on C60

    Full text link
    We investigate theoretically the progressive coating of C60 by several sodium atoms. Density functional calculations using a nonlocal functional are performed for NaC60 and Na2C60 in various configurations. These data are used to construct an empirical atomistic model in order to treat larger sizes in a statistical and dynamical context. Fluctuating charges are incorporated to account for charge transfer between sodium and carbon atoms. By performing systematic global optimization in the size range 1<=n<=30, we find that Na_nC60 is homogeneously coated at small sizes, and that a growing droplet is formed above n=>8. The separate effects of single ionization and thermalization are also considered, as well as the changes due to a strong external electric field. The present results are discussed in the light of various experimental data.Comment: 17 pages, 10 figure

    Quantifying Beta‐Galactosylceramide Kinetics in Cerebrospinal Fluid of Healthy Subjects Using Deuterium Labeling

    Get PDF
    Therapeutics promoting myelin synthesis may enhance recovery in demyelinating diseases, such as multiple sclerosis. However, no suitable method exists to quantify myelination. The turnover of galactosylceramide (myelin component) is indicative of myelination in mice, but its turnover has not been determined in humans. Here, six healthy subjects consumed 120 mL 70% D2 O daily for 70 days to label galactosylceramide. We then used mass spectrometry and compartmental modeling to quantify the turnover rate of galactosylceramide in cerebrospinal fluid. Maximum deuterium enrichment of body water ranged from 1.5-3.9%, whereas that of galactosylceramide was much lower: 0.05-0.14%. This suggests a slow turnover rate, which was confirmed by the model-estimated galactosylceramide turnover rate of 0.00168 day-1 , which corresponds to a half-life of 413 days. Additional studies in patients with multiple sclerosis are needed to investigate whether galactosylceramide turnover could be used as an outcome measure in clinical trials with remyelination therapies.PharmacologyAnalytical BioScience
    • 

    corecore