271 research outputs found

    P2X₃ Knock-Out Mice Reveal a Major Sensory Role for Urothelially Released ATP

    Get PDF
    The present study explores the possible involvement of a purinergic mechanism in mechanosensory transduction in the bladder using P2X₃ receptor knock-out (P2X₃ ⁻⁄⁻) and wild-type control (P2X₃ âș⁄âș) mice. Immunohistochemistry revealed abundant nerve fibers in a suburothelial plexus in the mouse bladder that are immunoreactive to anti-P2X₃. P2X₃ -positive staining was completely absent in the subepithelial plexus of the P2X₃ ⁻⁄⁻ mice, whereas staining for calcitonin gene-related peptide and vanilloid receptor 1 receptors remained. Using a novel superfused mouse bladder–pelvic nerve preparation, we detected a release of ATP proportional to the extent of bladder distension in both P2X₃ ⁻⁄⁻ mice, whereas staining for calcitonin gene-related peptide and vanilloid receptor 1 receptors remained. Using a novel superfused mouse bladder–pelvic nerve preparation, we detected a release of ATP proportional to the extent of bladder distension in both P2X₃ âș⁄âș and P2X₃ ⁻⁄⁻ mice, although P2X₃ ⁻⁄⁻ bladder had an increased capacity compared with that of the P2X₃ âș⁄âș bladder. The activity of multifiber pelvic nerve afferents increased progressively during gradual bladder distension (at a rate of 0.1 ml/min). However, the bladder afferents from P2X₃ ⁻⁄⁻ mice showed an attenuated response to bladder distension. Mouse bladder afferents of P2X₃ âș⁄âș, but not P2X₃ ⁻⁄⁻, were rapidly activated by intravesical injections of P2X agonists (ATP or α,ÎČ-methylene ATP) and subsequently showed an augmented response to bladder distension. By contrast, P2X antagonists [2â€Č,3â€Č-O-(2,4,6-trinitrophenyl)-ATP and pyridoxal 5-phosphate 6-azophenyl-2â€Č,4â€Č-disulfonic acid] and capsaicin attenuated distension-induced discharges in bladder afferents. These data strongly suggest a major sensory role for urothelially released ATP acting via P2X₃ receptors on a subpopulation of pelvic afferent fibers

    The effect of timing and composition of gestational weight gain in obese pregnant women on infant birth weight: A prospective cohort study.

    Get PDF
    Introduction: CK2 is a protein kinase implicated in several essential cellular processes, over-expressed in cancer and described to regulate insulin signaling cascade. Recently CK2 has been described to negatively regulate thermogenesis (Shinoda K et al, 2015, Cell Metabolism) and to inhibit insulin release (Rossi M et al, 2015, PNAS). Nevertheless, the role of CK2 in adipose tissue (AT) and its involvement in human obesity development and therapy has been poorly investigated. Methods: Our multi-disciplinary team performed biochemical analysis of signaling pathways by WB and in vitro kinase activity assays, and glucose handling studies using glucose uptake assay and IF in adipocyte cultures and glucose and insulin tolerance test in mice. Moreover we quantify CK2 expression/activity in human AT specimens of 27 obese patients, clinically characterized, in 12 obese patients underwent relevant weight loss and 11 normal-weight controls. Results: We proved that CK2 amount and activity were not influenced by insulin stimulation and that CK2 activity was efficiently inhibited by specific inhibitors, structurally unrelated. We worked with CX-4945, a CK2 inhibitor currently used in cancer clinical trials, using the minimal concentration (2.5 \u192 dM) and pre-treatment time (1hr) able to efficiently inhibit CK2 activity, avoiding any cytotoxic effect. Pharmacological inhibition of CK2 did not significantly affect in vitro adipogenic differentiation or expression profiling of mature adipocytes. Conversely, we showed that in human and murine adipocytes CK2-inhibition decreases the insulin-induced glucose uptake by counteracting Akt-signaling and GLUT4-translocation to the plasma membrane. We compared CK2 expression and activity in different mouse tissues highlighted that white skeletal muscle fibres and liver contained the highest quantity of this kinase. CK2 was expressed more in brown AT than in white AT depots. We show that CK2 promotes insulin-signaling in mouse AT, liver and skeletal muscle and that in vivo acute treatment with CX-4945 impairs glucose- tolerance in mice. Studies in tissues of ob/ob and db/db mice highlights an up-regulation of CK2 expression and activity only in WAT. CK2 hyper-activation is strongly evident also in SAT and VAT of obese patients and weight loss obtained by bariatric surgery or hypocaloric diet reverts CK2 up-regulation to normal level. Conclusion: We show that CK2 is involved in insulin sensitivity, glucose handling and remodeling of WAT. Moreover we identify CK2 hyper-activation as a hallmark of human obesity, suggesting a new potential therapeutic target for metabolic diseases

    Enantiopure Dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophenes: Reaching High Magnetoresistance Effect in OFETs

    Get PDF
    Chiral molecules are known to behave as spin filters due to the chiral induced spin selectivity (CISS) effect. Chirality can be implemented in molecular semiconductors in order to study the role of the CISS effect in charge transport and to find new materials for spintronic applications. In this study, the design and synthesis of a new class of enantiopure chiral organic semiconductors based on the well-known dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene (DNTT) core functionalized with chiral alkyl side chains is presented. When introduced in an organic field-effect transistor (OFET) with magnetic contacts, the two enantiomers, (R)-DNTT and (S)-DNTT, show an opposite behavior with respect to the relative direction of the magnetization of the contacts, oriented by an external magnetic field. Each enantiomer displays an unexpectedly high magnetoresistance over one preferred orientation of the spin current injected from the magnetic contacts. The result is the first reported OFET in which the current can be switched on and off upon inversion of the direction of the applied external magnetic field. This work contributes to the general understanding of the CISS effect and opens new avenues for the introduction of organic materials in spintronic devices

    Nutrient cycling in bedform induced hyporheic zones

    Get PDF
    The hyporheic zone is an ecotone connecting the stream and groundwater ecosystem that plays a significant role for stream biogeochemistry. Water exchange across the stream-sediment interface and biogeochemical reactions in the streambed concur to affect subsurface solute concentrations and eventually nutrient cycling in the fluvial corridor. In this paper we investigate the interplay of hydrological and biogeochemical processes in a duned streambed and their effect on spatial distribution of solutes. We employ a numerical model to simulate the turbulent water flow and the pressure distribution over the dunes, and then to evaluate the flow field and the biogeochemical reactions in the hyporheic sediments. Sensitivity analyses are performed to analyze the influence of hydrological and chemical properties of the system on solute reaction rates. The results demonstrate the effect of stream velocity and sediment permeability on the chemical zonation. Changing sediment permeability as well as stream velocity directly affects the nutrient supply and the residence times in the streambed, thus controlling the reaction rates under the dune. Stream-water quality is also shown to influence the reactive behavior of the sediments. In particular, the availability of dissolved organic carbon determines whether the streambed acts as a net sink or source of nitrate. This study represents a step towards a better understanding of the complex interactions between hydrodynamical and biogeochemical processes in the hyporheic zon

    First-Order Contaminant Removal in the Hyporheic Zone of Streams: Physical Insights from a Simple Analytical Model

    Full text link
    A simple analytical model is presented for the removal of stream-borne contaminants by hyporheic exchange across duned or rippled streambeds. The model assumes a steady-state balance between contaminant supply from the stream and first-order reaction in the sediment. Hyporheic exchange occurs by bed form pumping, in which water and contaminants flow into bed forms in high-pressure regions (downwelling zones) and out of bed forms in low-pressure regions (upwelling zones). Model-predicted contaminant concentrations are higher in downwelling zones than upwelling zones, reflecting the strong coupling that exists between transport and reaction in these systems. When flow-averaged, the concentration difference across upwelling and downwelling zones drives a net contaminant flux into the sediment bed proportional to the average downwelling velocity. The downwelling velocity is functionally equivalent to a mass transfer coefficient, and can be estimated from stream state variables including stream velocity, bed form geometry, and the hydraulic conductivity and porosity of the sediment. Increasing the mass transfer coefficient increases the fraction of streamwater cycling through the hyporheic zone (per unit length of stream) but also decreases the time contaminants undergo first-order reaction in the sediment. As a consequence, small changes in stream state variables can significantly alter the performance of hyporheic zone treatment systems

    NG2 antigen is involved in leukemia invasiveness and central nervous system infiltration in MLL-rearranged infant B-ALL

    Get PDF
    Mixed-lineage leukemia (MLL)-rearranged (MLLr) infant B-cell acute lymphoblastic leukemia (iMLLr-B-ALL) has a dismal prognosis and is associated with a pro-B/mixed phenotype, therapy refractoriness and frequent central nervous system (CNS) disease/relapse. Neuron-glial antigen 2 (NG2) is specifically expressed in MLLr leukemias and is used in leukemia immunophenotyping because of its predictive value for MLLr acute leukemias. NG2 is involved in melanoma metastasis and brain development; however, its role in MLL-mediated leukemogenesis remains elusive. Here we evaluated whether NG2 distinguishes leukemia-initiating/propagating cells (L-ICs) and/or CNS-infiltrating cells (CNS-ICs) in iMLLr-B-ALL. Clinical data from the Interfant cohort of iMLLr-B-ALL demonstrated that high NG2 expression associates with lower event-free survival, higher number of circulating blasts and more frequent CNS disease/relapse. Serial xenotransplantation of primary MLL-AF4 + leukemias indicated that NG2 is a malleable marker that does not enrich for L-IC or CNS-IC in iMLLr-B-All. However, NG2 expression was highly upregulated in blasts infiltrating extramedullar hematopoietic sites and CNS, and specific blockage of NG2 resulted in almost complete loss of engraftment. Indeed, gene expression profiling of primary blasts and primografts revealed a migratory signature of NG2 + blasts. This study provides new insights on the biology of NG2 in iMLLr-B-ALL and suggests NG2 as a potential therapeutic target to reduce the risk of CNS disease/relapse and to provide safer CNS-directed therapies for iMLLr-B-ALL

    Long-term morphological and hormonal follow-up in a single unit on 115 patients with adrenal incidentalomas

    Get PDF
    We investigated the natural course of adrenal incidentalomas in 115 patients by means of a long-term endocrine and morphological (CT) follow-up protocol (median 4 year, range 1–7 year). At entry, we observed 61 subclinical hormonal alterations in 43 patients (mainly concerning the ACTH–cortisol axis), but confirmatory tests always excluded specific endocrine diseases. In all cases radiologic signs of benignity were present. Mean values of the hormones examined at last follow-up did not differ from those recorded at entry. However in individual patients several variations were observed. In particular, 57 endocrine alterations found in 43 patients (37.2%) were no longer confirmed at follow-up, while 35 new alterations in 31 patients (26.9%) appeared de novo. Only four alterations in three patients (2.6%) persisted. Confirmatory tests were always negative for specific endocrine diseases. No variation in mean mass size was found between values at entry (25.4±0.9 mm) and at follow-up (25.7±0.9 mm), although in 32 patients (27.8%) mass size actually increased, while in 24 patients (20.8%) it decreased. In no case were the variations in mass dimension associated with the appearance of radiological criteria of malignancy. Kaplan–Meier curves indicated that the cumulative risk for mass enlargement (65%) and for developing endocrine abnormalities (57%) over time was progressive up to 80 months and independent of haemodynamic and humoral basal characteristics. In conclusion, mass enlargement and the presence or occurrence over time of subclinical endocrine alterations are frequent and not correlated, can appear at any time, are not associated with any basal predictor and, finally, are not necessarily indicative of malignant transformation or of progression toward overt disease

    Postoperative outcomes in oesophagectomy with trainee involvement

    Get PDF
    BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery
    • 

    corecore