Gene deficiency in activating Fcγ receptors influences the macrophage phenotypic balance and reduces atherosclerosis in mice

Immunity contributes to arterial inflammation during atherosclerosis. Oxidized low-density lipoproteins induce an autoimmune response characterized by specific antibodies and immune complexes in atherosclerotic patients. We hypothesize that specific Fcγ receptors for IgG constant region participate in atherogenesis by regulating the inflammatory state of lesional macrophages. In vivo we examined the role of activating Fcγ receptors in atherosclerosis progression using bone marrow transplantation from mice deficient in γ-chain (the common signaling subunit of activating Fcγ receptors) to hyperlipidemic mice. Hematopoietic deficiency of Fcγ receptors significantly reduced atherosclerotic lesion size, which was associated with decreased number of macrophages and T lymphocytes, and increased T regulatory cell function. Lesions of Fcγ receptor deficient mice exhibited increased plaque stability, as evidenced by higher collagen and smooth muscle cell content and decreased apoptosis. These effects were independent of changes in serum lipids and antibody response to oxidized low-density lipoproteins. Activating Fcγ receptor deficiency reduced pro-inflammatory gene expression, nuclear factor-κB activity, and M1 macrophages at the lesion site, while increasing anti-inflammatory genes and M2 macrophages. The decreased inflammation in the lesions was mirrored by a reduced number of classical inflammatory monocytes in blood. In vitro, lack of activating Fcγ receptors attenuated foam cell formation, oxidative stress and pro-inflammatory gene expression, and increased M2-associated genes in murine macrophages. Our study demonstrates that activating Fcγ receptors influence the macrophage phenotypic balance in the artery wall of atherosclerotic mice and suggests that modulation of Fcγ receptor-mediated inflammatory responses could effectively suppress atherosclerosis

Facile Preparation of Optically Tailored Hybrid Nanocomposite

Lead sulfide nanoparticles (PbS NPs) have been synthesized directly in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) semiconducting polymer by a simple low temperature method. Hybrid solutions with different concentrations of PbS with respect to the polymer have been prepared and characterized first in solution and then as thin film nanocomposites deposited on quartz substrates by spin coating. Quenching of photoluminescence emission is observed both in solutions and thin films when the ratio of PbS NPs increases with respect to the polymer, suggesting the occurrence of Dexter energy transfer from the polymer to the PbS NPs. Optical absorption is markedly increased for hybrid solutions compared to pure polymer. In thin nanocomposite films an enhancement of absorbance is observed with increasing PbS NPs concentration, which is more pronounced below 400 nm. The reported results could lead to the development of a method for tailoring the optical response of devices based on PbS NP-polymer nanocomposite by controlling the PbS NP concentration inside the polymer matrix

Transfusion of human platelets treated with Mirasol pathogen reduction technology does not induce acute lung injury in mice

Pathogen reduction technology (PRT) has been developed in an effort to make the blood supply safer, but there is controversy as to whether it may induce structural or functional changes to platelets that could lead to acute lung injury after transfusion. In this study, we used a commercial PRT system to treat human platelets that were then transfused into immunodeficient mice, and the development of acute lung injury was determined. P-selectin expression was higher in the Mirasol PRT-treated platelets compared to control platelets on storage day 5, but not storage day 1. Transfusion of control vs. Mirasol PRT-treated platelets (day 5 of storage, 109 platelets per mouse) into NOD/SCID mice did not result in lung injury, however transfusion of storage day 5 platelets treated with thrombin receptor-activating peptide increased both extravascular lung water and lung vascular permeability. Transfusion of day 1 platelets did not produce lung injury in any group, and LPS priming 24 hours before transfusion had no effect on lung injury. In a model of transfusion-related acute lung injury, NOD/SCID mice were susceptible to acute lung injury when challenged with H-2Kd monoclonal antibody vs. isotype control antibody. Using lung intravital microscopy, we did not detect a difference in the dynamic retention of platelets in the lung circulation in control vs. Mirasol PRT-treated groups. In conclusion, Mirasol PRT produced an increase in Pselectin expression that is storage-dependent, but transfusion of human platelets treated with Mirasol PRT into immunodeficient mice did not result in greater platelet retention in the lungs or the development of acute lung injury. Copyright

Películas fluorescentes azules basadas en derivados de poli-2,7-fluorenofenilideno

Quaternization of poly-(9,9-bis(6’-bromohexyl)fluorenephenylene by treatment with trimethylamine gas was used to obtain a water soluble ammonium salt copolymer. The neutral copolymer containing fluorene/phenylene alternating repeating units was obtained by a palladiumcatalyzed Suzuki coupling reaction. This strategy could be applied to prepare water soluble conjugated polymers with the ability to change the charge functionality. The polymers were characterized by gel permeation chromatography (GPC), 1H and 13C NMR spectroscopy, FT-IR spectroscopy, and thermogravimetric analysis (TGA). The neutral polymer was stable to over 300ºC, while the cationic polymer begins to degrade at 120ºC with a progressive loss of mass at 290ºC. The optical properties of the polymers were investigated in solution and solid phases by UV/VIS and fluorescent spectroscopy. Mesoporous silica thin films were prepared as a host matrix for the fluorescent copolymers.<br><br>La cuaternización del poli-(9,9-bis(6’-bromohexilo)fluorenofenileno) por tratamiento de trimetilamina gaseosa se emplea para obtener una sal de amonio del copolímero precursor soluble en agua. El copolímero neutro contiene unidades alternantes repetitivas de fluoreno/ fenilideno obtenidas mediante una acoplamiento de Suzuki con Pd (II). Los polímeros se caracterizaron por cromatografía de permeación (GPC), espectroscopia RMN de 1H y 13C , espectroscopia IR transformada de Fourier y análisis termogravimétrico (ATG). El polímero neutro mantiene la estabilidad hasta los 300ºC, mientras el derivado catiónico comienza a descomponer a 120ºC, con una progresiva perdida de masa hasta los 290ºC. Las propiedades ópticas de los polímeros se estudiaron en disolución y en películas mediante espectroscopias UV/VIS y de fluorescencia. Las películas delgadas de sílice mesoporosa se prepararon como materiales receptores de los copolímeros fluorescentes

The Immune System of Marine Organisms as Source for Drugs against Infectious Diseases.

The high proliferation of microorganisms in aquatic environments has allowed their coevolution for billions of years with other living beings that also inhabit these niches. Among the different existing types of interaction, the eternal competition for supremacy between the susceptible species and their pathogens has selected, as part of the effector division of the immune system of the former ones, a vast and varied arsenal of efficient antimicrobial molecules, which is highly amplified by the broad biodiversity radiated, above any others, at the marine habitats. At present, the great recent scientific and technological advances already allow the massive discovery and exploitation of these defense compounds for therapeutic purposes against infectious diseases of our interest. Among them, antimicrobial peptides and antimicrobial metabolites stand out because of the wide dimensions of their structural diversities, mechanisms of action, and target pathogen ranges. This revision work contextualizes the research in this field and serves as a presentation and scope identification of the Special Issue from Marine Drugs journal "The Immune System of Marine Organisms as Source for Drugs against Infectious Diseases"

Estudio de la defoliación específica del ovino en pastoreo y su efecto sobre la estructura de pastos de puerto en Cantabria

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Eficacia de distintos métodos de recuperación de pasto de puerto invadidos por lecherina (Euphorbia polygalifolia)

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Interaction between Poly(9,9-bis(6′-N,N,N-trimethylammonium)hexyl)fluorene phenylene) Bromide and DNA as Seen by Spectroscopy, Viscosity, and Conductivity: Effect of Molecular Weights and DNA Secondary Structure

The interaction between three poly(9,9-bis(6-N,N,N-trimethylammonium)hexyl)fluorene phenylene) bromide (HTMA-PFP) samples of different molecular weights (Mn = 14.5, 30.1 and 61.3 kg/mol) and both dsDNA and ssDNA secondary structures has been studied using UV−visible absorption and fluorescence spectroscopies (including steady-state, time-resolved, and anisotropy measurements for the latter), viscosity, and electrical conductivity in 4% (v/v) DMSO−water mixtures. At low nucleic acid concentrations, formation of a 1:1 complex in terms of HTMA-PFP repeat units and DNA bases occurs. This interaction results in quenching of polymer emission. For higher molar ratios of DNA to HTMA-PFP, corresponding to charge neutralization, a second process is observed that is attributed to aggregate formation. From the changes in the absorption spectra, the polymer aggregation constant and the aggregate absorption spectra were calculated by applying an iterative method. Polymer aggregation dramatically quenches HTMA-PFP fluorescence in the region of the electroneutrality point. Under these conditions, the ratio of the emission intensity at 412 nm (maximum) to that at 434 nm (I412/I434) reaches a minimum, the electrical conductivity decreases, and the viscosity of the solution remains constant, showing that the DNA concentration can be determined through various HTMA-PFP physicochemical properties. With respect to the photophysical parameters (emission quantum yield, shape and shift of emission spectra), no significant differences were observed between dsDNA and ssDNA or with conjugated polymer or DNA molecular weight. The two short-lived components in the fluorescence decays are attributed to the presence of aggregates. Aggregates are also suggested to be responsible for the decrease in the fluorescence anisotropy through interchain exciton migration