64 research outputs found

    Evaluation of known and novel inhibitors of Orai1-mediated store operated Ca2+ entry in MDA-MB-231 breast cancer cells using a Fluorescence Imaging Plate Reader assay

    Get PDF
    The Orai1 Ca2+ permeable ion channel is an important component of store operated Ca2+ entry (SOCE) in cells. It's over-expression in basal molecular subtype breast cancers has been linked with poor prognosis, making it a potential target for drug development. We pharmacologically characterised a number of reported inhibitors of SOCE in MDA-MB-231 breast cancer cells using a convenient Fluorescence Imaging Plate Reader (FLIPR) assay, and show that the rank order of their potencies in this assay is the same as those reported in a wide range of published assays. The assay was also used in a screening project seeking novel inhibitors. Following a broad literature survey of classes of calcium channel inhibitors we used simplified ligand structures to query the ZINC on-line database, and following two iterations of refinement selected a novel Orai1-selective dichlorophenyltriazole hit compound. Analogues of this were synthesized and evaluated in the FLIPR assay to develop structure-activity relationships (SAR) for the three domains of the hit; triazole (head), dichlorophenyl (body) and substituted phenyl (tail). For this series, the results suggested the need for a lipophilic tail domain and an out-of-plane twist between the body and tail domains. (C) 2016 Elsevier Ltd. All rights reserved

    Analgesic treatment of ciguatoxin-induced cold allodynia

    Get PDF
    Ciguatera, the most common form of nonbacterial ichthyosarcotoxism, is caused by consumption of fish that have bioaccumulated the polyether sodium channel activator ciguatoxin. The neurological symptoms of ciguatera include distressing, often persistent sensory disturbances such as paraesthesias and the pathognomonic symptom of cold allodynia. We show that intracutaneous administration of ciguatoxin in humans elicits a pronounced axon-reflex flare and replicates cold allodynia. To identify compounds able to inhibit ciguatoxin-induced Na-v responses, we developed a novel in vitro ciguatoxin assay using the human neuroblastoma cell line SH-SY5Y. Pharmacological characterisation of this assay demonstrated a major contribution of Na(v)1.2 and Na(v)1.3, but not Na(v)1.7, to ciguatoxin-induced Ca2+ responses. Clinically available Nav inhibitors, as well as the K(v)7 agonist flupirtine, inhibited tetrodotoxin-sensitive ciguatoxin-evoked responses. To establish their in vivo efficacy, we used a novel animal model of ciguatoxin-induced cold allodynia. However, differences in the efficacy of these compounds to reverse ciguatoxin-induced cold allodynia did not correlate with their potency to inhibit ciguatoxin-induced responses in SH-SY5Y cells or at heterologously expressed Nav1.3, Na(v)1.6, Na(v)1.7, or Na(v)1.8, indicating cold allodynia might be more complex than simple activation of Na-v channels. These findings highlight the need for suitable animal models to guide the empiric choice of analgesics, and suggest that lamotrigine and flupirtine could be potentially useful for the treatment of ciguatera. (C) 2013 International Association for the Study of Pain. Published by Elsevier B. V. All rights reserved

    Prevalence of pain in the departments of surgery and oncohematology of a paediatric hospital that has joined the project "Towards pain free hospital"

    Get PDF
    Background. Among hospitalized adults and children pain is undertreated. This study wants to assess the effectiveness of pain therapy in two departments of a large children's hospital. Materials and Methods. During a single day work three committees, administering a questionnaire to patients or parents, have evaluated the adherence to international recommendations (JCI and WHO) in the management of analgesic therapy. Patient demographics, prevalence and intensity (moderate and/or severe) of pain (during hospitalization, 24 hours before and at the time of the interview), analgesia (type, route, duration and frequency of administration) and Pain Management Index (=analgesic score-pain score) were recorded. Results. 75 patients participated in the study (age: 2 months up to 24 years, mean 7.8 ± 6). During hospitalization 43 children (57%) had no pain while 32 (43%) have experienced pain. 22 children (29 %) had pain 24 hours before and 12 (16%) at the time of the interview. The average value of the PMI was -0.8±1.3 with a minimum of -3 and a maximum of +2: 60% (19) of the children had a PMI less than 0 (undertreated pain) while 40% (13) had a value=or > 0. Out of 32 patients who needed an analgesic therapy 14 (44%) received an around-the-clock dosing, 8 (25%) an intermittent therapy and 10 (31%) no treatment.17 (77 %) were the single drug therapy and 5 (23%) the multimodal ones. Conclusion. The prevalence of pain in the two departments is high. The main cause is that knowledge is not still well translated into clinical practice

    Multiple sodium channel isoforms mediate the pathological effects of Pacific ciguatoxin-1

    Get PDF
    This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Human intoxication with the seafood poison ciguatoxin, a dinoflagellate polyether that activates voltage-gated sodium channels (NaV), causes ciguatera, a disease characterised by gastrointestinal and neurological disturbances. We assessed the activity of the most potent congener, Pacific ciguatoxin-1 (P-CTX-1), on NaV1.1–1.9 using imaging and electrophysiological approaches. Although P-CTX-1 is essentially a non-selective NaV toxin and shifted the voltage-dependence of activation to more hyperpolarising potentials at all NaV subtypes, an increase in the inactivation time constant was observed only at NaV1.8, while the slope factor of the conductance-voltage curves was significantly increased for NaV1.7 and peak current was significantly increased for NaV1.6. Accordingly, P-CTX-1-induced visceral and cutaneous pain behaviours were significantly decreased after pharmacological inhibition of NaV1.8 and the tetrodotoxin-sensitive isoforms NaV1.7 and NaV1.6, respectively. The contribution of these isoforms to excitability of peripheral C- and A-fibre sensory neurons, confirmed using murine skin and visceral single-fibre recordings, reflects the expression pattern of NaV isoforms in peripheral sensory neurons and their contribution to membrane depolarisation, action potential initiation and propagation

    Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

    Get PDF
    Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk

    SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries

    Get PDF
    We present high-cadence UV, optical, and near-infrared data on the luminous Type II-P supernova SN2017gmr from hours after discovery through the first 180 days. SN2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical light-curve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early light curve indicates a ∼500 Re progenitor radius, consistent with a rather compact red supergiant, and latetime luminosities indicate that up to 0.130±0.026 Me of 56Ni are present, if the light curve is solely powered by radioactive decay, although the 56Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multipeaked emission lines of Hα and [O I] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first 2 days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta

    A small-molecule inhibitor of the NLRP3 inflammasome for the treatment of inflammatory diseases

    Get PDF
    The NOD-like receptor (NLR) family, pyrin domain-containing protein 3 (NLRP3) inflammasome is a component of the inflammatory process, and its aberrant activation is pathogenic in inherited disorders such as cryopyrin-associated periodic syndrome (CAPS) and complex diseases such as multiple sclerosis, type 2 diabetes, Alzheimer's disease and atherosclerosis. We describe the development of MCC950, a potent, selective, small-molecule inhibitor of NLRP3. MCC950 blocked canonical and noncanonical NLRP3 activation at nanomolar concentrations. MCC950 specifically inhibited activation of NLRP3 but not the AIM2, NLRC4 or NLRP1 inflammasomes. MCC950 reduced interleukin-1 beta (IL-1 beta) production in vivo and attenuated the severity of experimental autoimmune encephalomyelitis (EAE), a disease model of multiple sclerosis. Furthermore, MCC950 treatment rescued neonatal lethality in a mouse model of CAPS and was active in ex vivo samples from individuals with Muckle-Wells syndrome. MCC950 is thus a potential therapeutic for NLRP3-associated syndromes, including autoinflammatory and autoimmune diseases, and a tool for further study of the NLRP3 inflammasome in human health and disease

    Investigating the properties of stripped-envelope supernovae; what are the implications for their progenitors?

    Get PDF
    We present observations and analysis of 18 stripped-envelope supernovae observed during 2013-2018. This sample consists of five H/He-rich SNe, six H-poor/He-rich SNe, three narrow lined SNe Ic, and four broad lined SNe Ic. The peak luminosity and characteristic time-scales of the bolometric light curves are calculated, and the light curves modelled to derive 56Ni and ejecta masses (MNi and Mej). Additionally, the temperature evolution and spectral line velocity curves of each SN are examined. Analysis of the [O I] line in the nebular phase of eight SNe suggests their progenitors had initial masses ☉. The bolometric light curve properties are examined in combination with those of other SE events from the literature. The resulting data set gives the Mej distribution for 80 SE-SNe, the largest such sample in the literature to date, and shows that SNe Ib have the lowest median Mej, followed by narrow-lined SNe Ic, H/He-rich SNe, broad-lined SNe Ic, and finally gamma-ray burst SNe. SNe Ic-6/7 show the largest spread of Mej ranging from ∼1.2-11 M☉, considerably greater than any other subtype. For all SE-SNe ej> = 2.8 ± 1.5 M☉ which further strengthens the evidence that SE-SNe arise from low-mass progenitors which are typically ☉ at the time of explosion, again suggesting MZAMS ☉. The low ej> and lack of clear bimodality in the distribution implies ☉ progenitors and that envelope stripping via binary interaction is the dominant evolutionary pathway of these SNe

    Pharmacological characterisation of alpha-conotoxins with therapeutic potential

    No full text
    • …
    corecore