1,469 research outputs found

    A staged screening of registered drugs highlights remyelinating drug candidates for clinical trials

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    There is no treatment for the myelin loss in multiple sclerosis, ultimately resulting in the axonal degeneration that leads to the progressive phase of the disease. We established a multi-tiered platform for the sequential screening of drugs that could be repurposed as remyelinating agents. We screened a library of 2,000 compounds (mainly Food and Drug Administration (FDA)-approved compounds and natural products) for cellular metabolic activity on mouse oligodendrocyte precursors (OPC), identifying 42 molecules with significant stimulating effects. We then characterized the effects of these compounds on OPC proliferation and differentiation in mouse glial cultures, and on myelination and remyelination in organotypic cultures. Three molecules, edaravone, 5-methyl-7-methoxyisoflavone and lovastatin, gave positive results in all screening tiers. We validated the results by retesting independent stocks of the compounds, analyzing their purity, and performing dose-response curves. To identify the chemical features that may be modified to enhance the compounds' activity, we tested chemical analogs and identified, for edaravone, the functional groups that may be essential for its activity. Among the selected remyelinating candidates, edaravone appears to be of strong interest, also considering that this drug has been approved as a neuroprotective agent for acute ischemic stroke and amyotrophic lateral sclerosis in Japan

    Leptomeningitis in a person with radiologically isolated syndrome and latent tuberculosis. A case report with implications for clinical research

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    A 39-year-old man, followed with serial MRI of CNS for a radiologically isolate syndrome (RIS, a recently described condition considered a subclinical form of MS), was hospitalized for the occurrence of a leptomeningitis. Routine blood tests and contrast enhanced total body CT scan were unremarkable. Cerebrospinal fluid (CSF) examination showed increase of cells (22 mononuclear cells/mm3), albumin (294 mg/L), immunoglobilins G (161 mg/L) and Link Index (1.9), with 17 oligoclonal bands. Microbiological examinations of CSF (including those for Koch’s Bacillus) were negative. The Mantoux reaction and the QuantiFERON test were positive, featuring a latent tuberculosis (TB). The patient started prophylaxis with rifampicin and isoniazid for four months, until a new MRI showed the disappearance of the leptomeningeal enhancement, and the stability of white matter brain and spinal cord lesions. Two other MRI scans showed a new brain Gd-enhancing lesion nine month after anti-tubercular therapy and, after additional six months, new cerebral and spinal cord areas. This case provides the following suggestions about the effects of TB infection and related therapies on the underlying autoimmune status: the infection, while actively present, did not exacerbate the RIS condition; the worsening nine months after the prophylaxis discontinuation might have been the ‘natural’ evolution of RIS condition. Alternative speculative hypotheses include a remote effect of the infection, of isoniazid (that was reported in some cases to trigger MS), or the result of the clearance of the infection itself. Irrespective of the existence of any interaction between RIS and TB infection, It seems important to collect cases with MS-related diseases and concomitant infections, that may provide clues about disease pathogenesis and treatment

    Genome-Wide Multiple Sclerosis Association Data and Coagulation

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    The emerging concept of a crosstalk between hemostasis, inflammation, and immune system prompt recent works on coagulation cascade in multiple sclerosis (MS). Studies on MS pathology identified several coagulation factors since the beginning of the disease pathophysiology: fibrin deposition with breakdown of blood brain barrier, and coagulation factors within active plaques may exert pathogenic role, especially through the innate immune system. Studies on circulating coagulation factors showed complex imbalance involving several components of hemostasis cascade (thrombin, factor X, factor XII). To analyze the role of the coagulation process in connection with other pathogenic pathways, we implemented a systematic matching of genome-wide association studies (GWAS) data with an informative and unbiased network of coagulation pathways. Using MetaCore (version 6.35 build 69300, 2018) we analyzed the connectivity (i.e., direct and indirect interactions among two networks) between the network of the coagulation process and the network resulting from feeding into MetaCore the MS GWAS data. The two networks presented a remarkable over-connectivity: 958 connections vs. 561 expected by chance; z-score = 17.39; p-value < 0.00001. Moreover, genes coding for cluster of differentiation 40 (CD40) and plasminogen activator, urokinase (PLAU) shared both networks, pointed to an integral interplay between coagulation cascade and main pathogenic immune effectors. In fact, CD40 pathways is especially operative in B cells, that are currently a major therapeutic target in MS field. The potential interaction of PLAU with a signal of paramount importance for B cell pathogenicity, such as CD40, suggest new lines of research and pave the way to implement new therapeutic targets

    The secondary metabolite euplotin c induces apoptosis-like death in the marine ciliated protist euplotes vannus

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    The sesquiterpenoid euplotin C is a secondary metabolite produced by the ciliated protist Euplotes crassus and provides a mechanism for damping populations of potential competitors. Indeed, E. crassus is virtually resistant to its own product while different non-producer species representing an unbiased sample of the marine, interstitial, ciliate diversity are sensitive. For instance, euplotin C exerts a marked disruption of different homeostatic mechanisms in Euplotes vannus. We demonstrate by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay that euplotin C quickly decreases viability and mitochondrial function of E. vannus with a very high efficacy and at micromolar potency. In addition, euplotin C induces apoptosis in E. vannus as 4,6-diamino-2-phenylindole and Terminal Transferase dUTP Nick End Labeling staining show the rapid condensation and fragmentation of nuclear material in cells treated with euplotin C. These effects occur without detectable permeabilisation or rupture of cell membranes and with no major changes in the overall morphology, although some traits, such as vacuolisation and disorganised microtubules, can be observed by transmission electron microscopy. In particular, E. vannus show profound changes of the mitochondrial ultrastructure. Finally, we also show that caspase activity in E. vannus is increased by euplotin C. These data elucidate the pro-apoptotic role of euplotin C and suggest a mechanism for its impact on natural selection.L'articolo è disponibile sul sito dell'editore http://onlinelibrary.wiley.com

    Role of the Adrenergic System in a Mouse Model of Oxygen-induced Retinopathy: Antiangiogenic Effects of Beta-adrenoreceptor Blockade

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    METHODS. Propranolol was administered subcutaneously and picropodophyllin (PPP) intraperitoneally. Intravitreal injections of vascular endothelial growth factor (VEGF) were performed. Messengers of -ARs, VEGF, its receptors, IGF-1 and IGF-1R were measured with quantitative RT-PCR. VEGF content was determined with ELISA. -ARs, hypoxia-inducible factor (HIF)-1 , occludin, and albumin were measured with Western blot. Retinal localization of 3-ARs was determined by immunohistochemistry. Retinopathy was assessed by scoring fluorescein-perfused retinas, and plasma extravasation was visualized by Evans blue dye

    Large-Area Nanocrystalline Caesium Lead Chloride Thin Films: A Focus on the Exciton Recombination Dynamics

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    Caesium lead halide perovskites were recently demonstrated to be a relevant class of semiconductors for photonics and optoelectronics. Unlike CsPbBr3 and CsPbI3, the realization of high-quality thin films of CsPbCl3, particularly interesting for highly efficient white LEDs when coupled to converting phosphors, is still a very demanding task. In this work we report the first successful deposition of nanocrystalline CsPbCl3 thin films (70–150 nm) by radio frequency magnetron sputtering on large-area substrates. We present a detailed investigation of the optical properties by high resolution photoluminescence (PL) spectroscopy, resolved in time and space in the range 10–300 K, providing quantitative information concerning carriers and excitons recombination dynamics. The PL is characterized by a limited inhomogeneous broadening (~15 meV at 10 K) and its origin is discussed from detailed analysis with investigations at the micro-scale. The samples, obtained without any post-growth treatment, show a homogeneous PL emission in spectrum and intensity on large sample areas (several cm2). Temperature dependent and time-resolved PL spectra elucidate the role of carrier trapping in determining the PL quenching up to room temperature. Our results open the route for the realization of large-area inorganic halide perovskite films for photonic and optoelectronic devices

    Peripheral Biomarkers in Manifest and Premanifest Huntington’s Disease

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    Huntington's disease (HD) is characterized by clinical motor impairment (e.g., involuntary movements, poor coordination, parkinsonism), cognitive deficits, and psychiatric symptoms. An inhered expansion of the CAG triplet in the huntingtin gene causing a pathogenic gain-of-function of the mutant huntingtin (mHTT) protein has been identified. In this review, we focus on known biomarkers (e.g., mHTT, neurofilament light chains) and on new biofluid biomarkers that can be quantified in plasma or peripheral blood mononuclear cells from mHTT carriers. Circulating biomarkers may fill current unmet needs in HD management: better stratification of patients amenable to etiologic treatment; the initiation of preventive treatment in premanifest HD; and the identification of peripheral pathogenic central nervous system cascades
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