2,770 research outputs found
Cytotoxic and pro-inflammatory early effects of mineral fibres on human alveolar epithelial and immune cells
When interacting with macrophages and epithelial lung cells, inhaled harmful particles trigger the pro-inflammatory process which, in turn, promotes the recruitment of circulating monocytes at the site of injury and their subsequent differentiation towards a macrophage phenotype. In this study, we evaluated the early cytotoxic and pro-inflammatory effect of three well-known carcinogenic fibres (i.e., crocidolite, chrysotile and erionite) on human THP-1 naïve monocytes and A549 alveolar epithelial cells, mimicking the recruitment and engagement of circulating monocytes at the site of fibre deposition. In both cell lines, all fibres showed significant direct cytotoxicity, with crocidolite and chrysotile inducing a higher time-dependent increase of the oxidative stress respect to erionite. Moreover, the direct exposure to the three fibres prompted the activation of THP-1 naïve monocytes towards the M0 pro-inflammatory phenotype, upregulating the gene expression of differentiation markers and promoting the release of pro-inflammatory cytokines. Finally, we evaluated the differentiation and activation of THP-1 naïve cells in response to conditioned media from fibre-treated A549 alveolar epithelial cells and M0-THP-1 macrophages. Interestingly, the exposure to chrysotile-treated media promoted the highest upregulation of pro-inflammatory mediators, suggesting that the soluble factors secreted in response to this fibre cause a stronger recruitment and activation of naïve monocytes
Simulated microgravity induces nuclear translocation of Bax and BCL-2 in glial cultured C6 cells
Alterations in the control of apoptotic processes were observed in cells during space flight or under simulated microgravity, the latter obtained with the 3D-Random Positioning Machine (3D-RPM). Usually the proteins Bax and Bcl-2, act as pro- or anti-apoptotic regulators. Here we investigated the effects of simulated microgravity obtained by the 3D-RPM on cell viability, localization and expression of Bax and Bcl-2 in cultures of glial cancerous cells. We observed for the first time a transient cytoplasmic/nuclear translocation of Bax and Bcl-2 triggered by changing gravity vector. Bax translocates into the nucleus after 1 h, is present simultaneously in the cytoplasm after 6 h and comes back to the cytoplasm after 24 h. Bcl-2 translocate into the nucleus only after 6 h and comes back to the cytoplasm after 24 h. Physiological meaning, on the regulation of apoptotic event and possible applicative outcomes of such finding are discussed
Bridging the gap between toxicity and carcinogenicity of mineral fibres by connecting the fibre parameters to the key characteristics of carcinogens: A comprehensive model inspiring asbestos-induced cancer prevention strategies
Background: Today, many research groups in the world are struggling to fully understand the mechanisms leading to the carcinogenesis of hazardous mineral fibres, like asbestos, in view of devising effective cancer prevention strategies and therapies. Along this research line, our work attempts the completion of a model aimed at evaluating how, and to what extent, physical-crystal-chemical and morphological parameters of mineral fibres prompt adverse effects in vivo leading to carcinogenesis. Methods: In vitro toxicology tests that deliver information on the 10 key characteristics of carcinogens adopted by the International Association for Research on Cancer (IARC) have been systematically collected for a commercial chrysotile, standard UICC crocidolite and wollastonite. The analysis of the in vitro data allowed us to assess the major fibre parameters responsible for alterations in the key characteristics of carcinogens for each investigated fibre and the intensity of their effect. Results: Crystal habit and density of the fibres affect exposure but are not major parameters contributing to the KCs. For chrysotile, besides length, we found that fibre parameters that greatly contribute to the KCs are the surface area and the dissolution rate with the related velocity of release of metals (namely iron). For crocidolite, they are the fibre length, iron content and related parameters like the ferrous iron content, iron nuclearity, transition metals content and zeta potential. Conclusions: The results of our study can be a starting point for developing personalized cancer screening and prevention strategies as long as the nature of the fibre of the exposed patient is known. We can speculate on a future personalized prevention therapy targeting the fibres with surface-engineered nanocarriers with active complexes that are selective for the surface charge of the fibres. For chrysotile, a complex with deferasirox that can chelate Fe2+ and deferoxamine that preferentially chelates Fe3+ is proposed with the anchorage to the silica chrysotile surface driven by aspartic acid. For crocidolite, deferiprone chelating both Fe3+ and Fe2+ combined with lysine to attract the silica crocidolite surface is proposed
Occupational exposure to electromagnetic fields in magnetic resonance environment: an update on regulation, exposure assessment techniques, health risk evaluation, and surveillance
Magnetic resonance imaging (MRI) is one of the most-used diagnostic imaging methods worldwide. There are ∼50,000 MRI scanners worldwide each of which involves a minimum of five workers from different disciplines who spend their working days around MRI scanners. This review analyzes the state of the art of literature about the several aspects of the occupational exposure to electromagnetic fields (EMF) in MRI: regulations, literature studies on biological effects, and health surveillance are addressed here in detail, along with a summary of the main approaches for exposure assessment. The original research papers published from 2013 to 2021 in international peer-reviewed journals, in the English language, are analyzed, together with documents published by legislative bodies. The key points for each topic are identified and described together with useful tips for precise safeguarding of MRI operators, in terms of exposure assessment, studies on biological effects, and health surveillance. Graphical abstract: [Figure not available: see fulltext.
PRIN 2017 Fibres - A Multidisciplinary Mineralogical, Crystal-Chemical and Biological Project. What have we learned after four years of research?
This opening paper introduces the contributions of this special issue on mineral fibres and reports a gallery of the major results accomplished within the multidisciplinary project PRIN (PROGETTI DI RICERCA DI RILEVANTE INTERESSE NAZIONALE) 2017 “FIBRES: a multidisciplinary mineralogical, crystal-chemical and biological project to amend the paradigm of toxicity and cancerogenicity of mineral fibres” by the six different Research Units from the Universities of Ancona, Genova, Modena, Rome, Pisa-Parma, and Urbino. The main goal of the project was to increase the knowledge of the mechanisms by which mineral fibres, with special attention to asbestos and fibrous erionite, prompt adverse effects in vivo, linking the fibres’ crystal-chemical-physical parameters to their toxicity/carcinogenicity potential and recasting the existing mechanistic ‘fibre toxicity paradigms’. This special issue contains specific contributions from each Research Unit of the project. The implications of the findings of the project are beyond the advance of the knowledge in the world of mineralogy/crystallography and constitute a remarkable progress in the understanding of the biological activity of mineral fibres in vivo
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
The large trans-Neptunian object 2002 TC302 from combined stellar occultation, photometry, and astrometry data
Context. Deriving physical properties of trans-Neptunian objects is important for the understanding of our Solar System. This requires observational efforts and the development of techniques suitable for these studies. Aims. Our aim is to characterize the large trans-Neptunian object (TNO) 2002 TC302. Methods. Stellar occultations offer unique opportunities to determine key physical properties of TNOs. On 28 January 2018, 2002 TC302 occulted a mv ~ 15.3 star with designation 593-005847 in the UCAC4 stellar catalog, corresponding to Gaia source 130957813463146112. Twelve positive occultation chords were obtained from Italy, France, Slovenia, and Switzerland. Also, four negative detections were obtained near the north and south limbs. This represents the best observed stellar occultation by a TNO other than Pluto in terms of the number of chords published thus far. From the 12 chords, an accurate elliptical fit to the instantaneous projection of the body can be obtained that is compatible with the near misses. Results. The resulting ellipse has major and minor axes of 543 ± 18 km and 460 ± 11 km, respectively, with a position angle of 3 ± 1 degrees for the minor axis. This information, combined with rotational light curves obtained with the 1.5 m telescope at Sierra Nevada Observatory and the 1.23 m telescope at Calar Alto observatory, allows us to derive possible three-dimensional shapes and density estimations for the body based on hydrostatic equilibrium assumptions. The effective diameter in equivalent area is around 84 km smaller than the radiometrically derived diameter using thermal data from Herschel and Spitzer Space Telescopes. This might indicate the existence of an unresolved satellite of up to ~300 km in diameter, which is required to account for all the thermal flux, although the occultation and thermal diameters are compatible within their error bars given the considerable uncertainty of the thermal results. The existence of a potential satellite also appears to be consistent with other ground-based data presented here. From the effective occultation diameter combined with absolute magnitude measurements we derive a geometric albedo of 0.147 ± 0.005, which would be somewhat smaller if 2002 TC302 has a satellite. The best occultation light curves do not show any signs of ring features or any signatures of a global atmosphere.Funding from Spanish projects AYA2014-56637-C2-1-P, AYA2017-89637-R, from FEDER, and Proyecto de Excelencia de la Junta de Andalucía 2012-FQM1776 is acknowledged. We would like to acknowledge financial support by the Spanish grant AYA-RTI2018-098657-JI00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE) and the financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV- 2017-0709). Part of the research received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378 and from the ERC programme under Grant Agreement no. 669416 Lucky Star. The following authors acknowledge the respective CNPq grants: FB-R 309578/2017-5; RV-M 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3; MA 427700/2018-3, 310683/2017-3, 473002/2013-2. This study was financed in part by the Coordenação de Aperfeiaçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). GBR acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016, MA FAPERJ grant E-26/111.488/2013 and ARGJr FAPESP grant 2018/11239-8. E.F.-V. acknowledges support from the 2017 Preeminent Postdoctoral Program (P3) at UCF. C.K., R.S., A.F-T., and G.M. have been supported by the K-125015 and GINOP-2.3.2-15-2016-00003 grants of the Hungarian National Research, Development and Innovation Office (NKFIH), Hungary. G.M. was also supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant PD-128 360. R.K. and T.P. were supported by the VEGA 2/0031/18 grant
Arecoline induces TNF-alpha production and Zonula Occludens-1 redistribution in mouse Sertoli TM4 cells
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