708 research outputs found

    PREPARATION, IDENTIFICATION AND BIOLOGICAL PROPERTIES OF NEW FLUORIDE NANOCOMPOUNDS

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    Indexación: Web of Science; Scopus.Nanoparticles (NPs) of new fluoride (SrF2 and MgF2) nanocompounds were synthesized by the simple chemical method of precipitation in ethanol. Synthesis of the strontium fluoride (SrF2)-magnesium oxide (MgO) nanocomposite was achieved through the ultrasonic method. These prepared nanopowders were characterized through Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). FT-IR confirmed the purity of the synthesized fluoride NPs by evaluation of the vibrations, and UV-Visible showed the intense absorption peaks of NPs. PXRD analysis indicated the average of particle size, and SEM demonstrated a nearly spherical morphology of the NPs. The antibacterical properties of the nanopowders on Staphylococcus Aureus, Bacillus Subtilis and E. Aklay bacteria were studied, with the strongest effect by the magnesium fluoride (MgF2) NPs and the SrF2-MgO nanocomposite.http://ref.scielo.org/yfr3f

    Edge-Illumination X-Ray Dark-Field Tomography

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    Dark-field imaging is an x-ray technique used to highlight subpixel, typically micrometer-scale, density fluctuations. It is often used alongside standard attenuation-based and also phase-contrast x-ray imaging, which both see regular use in tomography. We present x-ray dark-field computed tomography (CT) with a laboratory edge-illumination setup. The dark-field contrast is shown to increase linearly with the x-ray path length through the imaged object, a prerequisite for the use of standard tomographic reconstruction approaches. A multimaterial, custom-built phantom is used to show how dark-field contrast CT can complement attenuation contrast CT for the separation of materials based on their microstructure. As an example of a more complex, biological sample, we present a model rat heart. We show, by comparison with attenuation contrast tomography, that dark-field enables the identification of additional structures undetected through the attenuation contrast channel, as well as offering a consistently sharper reconstructed image

    Telocytes in minor salivary glands of primary Sjogren’s syndrome: association with the extent of inflammation and ectopic lymphoid neogenesis

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    It has been recently reported that telocytes, a stromal (interstitial) cell subset involved in the control of local tissue homeostasis, are hampered in the target organs of inflammatory/autoimmune disorders. Since no data concerning telocytes in minor salivary glands (MSGs) are currently available, aim of the study was to evaluate telocyte distribution in MSGs with normal architecture, non-specific chronic sialadenitis (NSCS) and primary Sjögren’s syndrome (pSS)-focal lymphocytic sialadenitis. Twelve patients with pSS and 16 sicca non-pSS subjects were enrolled in the study. MSGs were evaluated by haematoxylin and eosin staining and immunofluorescence for CD3/CD20 and CD21 to assess focus score, Tarpley biopsy score, T/B cell segregation and germinal center (GC)-like structures. Telocytes were identified by immunoperoxidase-based immunohistochemistry for CD34 and CD34/platelet-derived growth factor receptor α double immunofluorescence. Telocytes were numerous in the stromal compartment of normal MSGs, where their long cytoplasmic processes surrounded vessels and encircled both the excretory ducts and the secretory units. In NSCS, despite the presence of a certain degree of inflammation, telocytes were normally represented. Conversely, telocytes were markedly reduced in MSGs from pSS patients compared to normal and NSCS MSGs. Such a decrease was associated with both worsening of glandular inflammation and progression of ectopic lymphoid neogenesis, periductal telocytes being reduced in the presence of smaller inflammatory foci and completely absent in the presence of GC-like structures. Our findings suggest that a loss of MSG telocytes might have important pathophysiological implications in pSS. The specific pro-inflammatory cytokine milieu of pSS MSGs might be one of the causes of telocyte loss

    The onset site of rheumatoid arthritis: the joints or the lung?

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    The etiopathogenesis of rheumatoid arthritis (RA) is not yet fully elucidated and the site of inflammation onset is still a matter of debate. The presence of autoantibodies as well as clinical manifestations, such as interstitial lung disease, before the onset of arthritis seems to be in favour of the hypothesis that initial pathogenic events take place in tissues other than the joint. In this review article we summarize the most recent literature on extra-synovial autoimmunity triggers eventually leading to RA, with particular focus on the role of the lung. To date, anti-cyclic citrullinated peptide antibodies (ACPAs) are considered central players in RA pathogenesis and represent the gold-standard for disease diagnosis. Lungs and mucosae are exposed to environmental stimuli such as dusts and smoke which have been shown to foster citrullination of peptides in lungs thereby triggering the production of ACPA. In addition, other mechanisms of disease pathogenesis independent of citrullination play an important role. Deeper knowledge of these processes could represent a huge step forward in the management of RA, with dramatic impact on diagnosis, prevention, prognostic stratification and treatment of the disease

    FRI0565 PREVALENCE AND SIGNIFICANCE OF ANTIBODIES AGAINST CITRULLINATED ALPHA-ENOLASE (ANTI-CEP1) IN CONNECTIVE TISSUE DISEASES.

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    Background:Anti-cyclic citrullinated peptide (anti-CCP) auto-antibodies represent the current gold standard for the diagnosis of rheumatoid arthritis (RA). However, growing evidence suggests that a variety of other citrullinated self-proteins may act as autoantigens and lead to the production of autoantibodies (1). Furthermore, autoantibodies believed to be RA-specific have been detected also in patients with connective tissue diseases (CTDs). We recently demonstrated that antibodies against citrullinated alpha-enolase (anti-CEP1) are a biomarker of erosive disease and RA-associated interstitial lung disease (2).Objectives:The purpose of this study was to investigate the prevalence and possible prognostic value of anti-CEP-1 in patients with CTDs.Methods:Two hundred and twelve consecutive patients with CTDs (51 systemic lupus erythematosus (SLE), 85 primary Sjogren's syndrome (pSS) and 76 systemic sclerosis (SSc)) were studied and compared to 97 sex and age matched normal controls (NC) and 267 patients with RA. Anti-CEP1 IgG were detected in serum samples with a commercial ELISA kit (Euroimmun).Results:The overall prevalence of anti-CEP1 in CTDs was 7% (15/212 patients). In detail, these antibodies were detectable in 4 out of 85 pSS (5%), 5 out of 51 SLE (10%) and 6/76 SSc (8%). The prevalence and the titer of anti-CEP1 in CTDs was significantly higher compared to NC and significantly lower compared to RA. Anti-CEP1 positive patients did not display a specific clinical and serological picture. Unlike in RA, anti-CEP1 did not correlate with CTD-associated ILD.Conclusion:This is the first study assessing anti-CEP1 in a large cohort of patients with CTDs. We demonstrated that the association of these autoantibodies with ILD is specific for RA since it is not observed in SLE, pSS and SSc. Furthermore, although being significantly more prevalent and at higher titer compared to NC, anti-CEP1 do not allow to discriminate different patient subsets displaying peculiar clinical or serological phenotypes. Based on our results, the application of anti-CEP1 in CTDs is not advisable, however larger studies may possibly identify correlations not evident in our cohort.References:[1] Bonifacio AF, Alunno A, La Paglia GMC, Valentini E, Leone MC, Bartoloni E, Gerli R. Novel autoantibodies in rheumatoid arthritis. Reumatismo 2019;71(1):1-12[2] Alunno A, Bistoni O, Pratesi F, La Paglia GMC, Puxeddu I, Migliorini P, Gerli R. Anti-citrullinated alpha enolase antibodies, interstitial lung disease and bone erosion in rheumatoid arthritis. Rheumatology (Oxford). 2018;57(5):850-855Disclosure of Interests:Alessia Alunno: None declared, Francesco Carubbi Speakers bureau: Francesco Carubbi received speaker honoraria from Abbvie and Celgene outside this work., Onelia Bistoni: None declared, Matteo Antonucci: None declared, Elena Bartoloni Bocci: None declared, Roberto Giacomelli Grant/research support from: Actelion, Pfizer, Speakers bureau: Abbvie, Roche, Actelion, BMS, MSD, Ely Lilly, SOBI, Pfizer, Roberto Gerli: None declare

    The RNA Helicase DDX6 Controls Cellular Plasticity by Modulating P-Body Homeostasis

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    Post-transcriptional mechanisms have the potential to influence complex changes in gene expression, yet their role in cell fate transitions remains largely unexplored. Here, we show that suppression of the RNA helicase DDX6 endows human and mouse primed embryonic stem cells (ESCs) with a differentiation-resistant, “hyper-pluripotent” state, which readily reprograms to a naive state resembling the preimplantation embryo. We further demonstrate that DDX6 plays a key role in adult progenitors where it controls the balance between self-renewal and differentiation in a context-dependent manner. Mechanistically, DDX6 mediates the translational suppression of target mRNAs in P-bodies. Upon loss of DDX6 activity, P-bodies dissolve and release mRNAs encoding fate-instructive transcription and chromatin factors that re-enter the ribosome pool. Increased translation of these targets impacts cell fate by rewiring the enhancer, heterochromatin, and DNA methylation landscapes of undifferentiated cell types. Collectively, our data establish a link between P-body homeostasis, chromatin organization, and stem cell potency

    Altered Immunoregulation in Rheumatoid Arthritis: The Role of Regulatory T Cells and Proinflammatory Th17 Cells and Therapeutic Implications

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    In recent years several studies investigated the role of T lymphocyte subpopulations in the pathogenesis of rheumatoid arthritis (RA). Pathogenic Th17 cells mediate pannus growth, osteoclastogenesis, and synovial neoangiogenesis; hence they are key players in the development of the disease. On the other hand, regulatory T (Treg) cells are a T cell subset whose peculiar function is to suppress autoreactive lymphocytes. The imbalance between Th17 and Treg cells has been identified as a crucial event in the pathogenesis of RA. In addition, the effects of currently employed RA therapeutic strategies on these lymphocyte subpopulations have been extensively investigated. This review article aims to discuss current knowledge on Treg and Th17 cells in RA and possible implications of their therapeutic targeting in this disorder
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