158 research outputs found

    Chromatin modification of Apaf-1 restricts the apoptotic pathway in mature neurons

    Get PDF
    Although apoptosis has been extensively studied in developing neurons, the dynamic changes in this pathway after neuronal maturation remain largely unexplored. We show that as neurons mature, cytochrome c– mediated apoptosis progresses from inhibitor of apoptosis protein–dependent to –independent regulation because of a complete loss of Apaf-1 expression. However, after DNA damage, mature neurons resynthesize Apaf-1 through the cell cycle–related E2F1 pathway and restore their apoptotic potential. Surprisingly, we find that E2F1 is sufficient to induce Apaf-1 expression in developing but not mature neurons. Rather, Apaf-1 up-regulation in mature neurons requires both chromatin derepression and E2F1 transcriptional activity. This differential capacity of E2F1 to induce Apaf-1 transcription is because of the association of the Apaf-1 promoter with active chromatin in developing neurons and repressed chromatin in mature neurons. These data specifically illustrate how the apoptotic pathway in mature neurons becomes increasingly restricted by a novel mechanism involving the regulation of chromatin structure

    SULPHATED POLYSACCHARIDES (SPS) FROM THE GREEN ALGA ULVA FASCIATA EXTRACT MODULATES LIVER AND KIDNEY FUNCTION IN HIGH FAT DIET-INDUCED HYPERCHOLESTEROLEMIC RATS

    Get PDF
    Objective: Hypercholesterolemia (HC) was frequently associated with oxidative stress, and release of inflammatory cytokines is to determine the hypolipidemic effects of sulphated polysaccharides from seaweed Ulva fasciata algal extracts through measuring the activities of some parameters related to liver and kidney functions in the serum of hypercholesterolemic rats as compared to normal one.Methods: Different groups of rats were administered a high cholesterol diet. Liver and kidney functions, inflammatory cytokines (TNF-α, CRP, MPO and IL-10), oxidative stress (GSH, MDA and NO), in addition to cell adhesion molecules (ICAM-1 and VCAM-1) were assessed before and after treatment with the algal polysaccharides. In addition, histological examination of liver and kidney were performed to confirm the biochemical findings.Results: The obtained results showed that oxidative stress and inflammatory markers associated with hypercholesterolemia were significantly increased in HC-rats. The histopathological examination of liver and kidney demonstrated severe degeneration with diffuse vacuolar degeneration, necrosis and the presence of fatty droplets. In addition; nephron-histological examination revealed, mild glomerular injury with mild vascular and inflammatory changes. Treatment with the algal sulphated polysaccharides effectively improved these disorders and diminished the formation of fatty liver, as well as renal dysfunction more than the reference drug; fluvastatin. Conclusion: It could be concluded that the consumption of UFP (Ulva fasciata polysaccharides), may be associated with attenuation of inflammatory markers, amelioration of fatty liver and improvement of renal dysfunction, that in turn lead to counteract hypercholesterolemia and its related disorders; such as obesity, and heart disease.Keywords: Non-alcoholic fatty liver disease, Seaweed, Ulva fasciata, Hypercholesterolemia, Hypolipidemic activity, Sulphated polysaccharides (SPs

    Chemical Profile of Cyperus laevigatus and Its Protective Effects against Thioacetamide-Induced Hepatorenal Toxicity in Rats

    Get PDF
    Cyperus species represent a group of cosmopolitan plants used in folk medicine to treat several diseases. In the current study, the phytochemical profile of Cyperus laevigatus ethanolic extract (CLEE) was assessed using UPLC-QTOF–MS/MS. The protective effect of CLEE at 50 and 100 mg /kg body weight (b.w.) was evaluated on hepatorenal injuries induced by thioacetamide (100 mg/kg) via investigation of the extract’s effects on oxidative stress, inflammatory markers and histopathological changes in the liver and kidney. UPLC-QTOF–MS/MS analysis of CLEE resulted in the identification of 94 compounds, including organic and phenolic acids, flavones, aurones, and fatty acids. CLEE improved the antioxidant status in the liver and kidney, as manifested by enhancement of reduced glutathione (GSH) and coenzyme Q10 (CoQ10), in addition to the reduction in malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxy-2â€Č-deoxyguanosine (8OHdG). Moreover, CLEE positively affected oxidative stress parameters in plasma and thwarted the depletion of hepatorenal ATP content by thioacetamide (TAA). Furthermore, treatment of rats with CLEE alleviated the significant increase in plasma liver enzymes, kidney function parameters, and inflammatory markers. The protective effect of CLEE was confirmed by a histopathological study of the liver and kidney. Our results proposed that CLEE may reduce TAA-hepatorenal toxicity via its antioxidant and anti-inflammatory properties suppressing oxidative stress

    Fulminant Staphylococcus lugdunensis septicaemia following a pelvic varicella-zoster virus infection in an immune-deficient patient: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>The deadly threat of systemic infections with coagulase negative <it>Staphylococcus lugdunensis </it>despite an appropriate antibiotic therapy has only recently been recognized. The predominant infectious focus observed so far is left-sided native heart valve endocarditis, but bone and soft tissue infections, septicaemia and vascular catheter-related bloodstream infections have also been reported. We present a patient with a fatal <it>Staphylococcus lugdunensis </it>septicaemia following zoster bacterial superinfection of the pelvic region.</p> <p>Case presentation</p> <p>A 71-year old male diagnosed with IgG kappa plasmocytoma presented with a conspicuous weight loss, a hypercalcaemic crisis and acute renal failure. After initiation of haemodialysis treatment his condition improved rapidly. However, he developed a varicella-zoster virus infection of the twelfth thoracic dermatome requiring intravenous acyclovir treatment. Four days later the patient presented with a fulminant septicaemia. Despite an early intravenous antibiotic therapy with ciprofloxacin, piperacillin/combactam and vancomycin the patient died within 48 hours, shortly before the infective isolate was identified as <it>Staphylococcus lugdunensis </it>by polymerase chain reaction.</p> <p>Conclusion</p> <p>Despite <it>S. lugdunensis </it>belonging to the family of coagulase-negative staphylococci with an usually low virulence, infections with <it>S. lugdunensis </it>may be associated with an aggressive course and high mortality. This is the first report on a <it>Staphylococcus lugdunensis </it>septicaemia following a zoster bacterial superinfection of the pelvic region.</p

    Search for Quantum Gravity Using Astrophysical Neutrino Flavour with IceCube

    Full text link
    Along their long propagation from production to detection, neutrino states undergo quantum interference which converts their types, or flavours. High-energy astrophysical neutrinos, first observed by the IceCube Neutrino Observatory, are known to propagate unperturbed over a billion light years in vacuum. These neutrinos act as the largest quantum interferometer and are sensitive to the smallest effects in vacuum due to new physics. Quantum gravity (QG) aims to describe gravity in a quantum mechanical framework, unifying matter, forces and space-time. QG effects are expected to appear at the ultra-high-energy scale known as the Planck energy, EP≡1.22×1019E_{P}\equiv 1.22\times 10^{19}~giga-electronvolts (GeV). Such a high-energy universe would have existed only right after the Big Bang and it is inaccessible by human technologies. On the other hand, it is speculated that the effects of QG may exist in our low-energy vacuum, but are suppressed by the Planck energy as EP−1E_{P}^{-1} (∌10−19\sim 10^{-19}~GeV−1^{-1}), EP−2E_{P}^{-2} (∌10−38\sim 10^{-38}~GeV−2^{-2}), or its higher powers. The coupling of particles to these effects is too small to measure in kinematic observables, but the phase shift of neutrino waves could cause observable flavour conversions. Here, we report the first result of neutrino interferometry~\cite{Aartsen:2017ibm} using astrophysical neutrino flavours to search for new space-time structure. We did not find any evidence of anomalous flavour conversion in IceCube astrophysical neutrino flavour data. We place the most stringent limits of any known technologies, down to 10−4210^{-42}~GeV−2^{-2}, on the dimension-six operators that parameterize the space-time defects for preferred astrophysical production scenarios. For the first time, we unambiguously reach the signal region of quantum-gravity-motivated physics.Comment: The main text is 7 pages with 3 figures and 1 table. The Appendix includes 5 pages with 3 figure

    Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing

    Get PDF
    We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011–2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2Ξ23=0.51±0.05 and Δm232=2.41±0.07×10−3  eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties
    • 

    corecore