Cytokine dependence of B cell memory formation : a study in mice with emphasis on IgG1, and IgE

Mammals are born with virtually no self-generated immune protection. Immediately after birth they are more or less protected by antibodies that have crossed the placenta or are derived from the colostrum. This so called passive-immunization only holds for a limited period after birth. When the new-born is exposed to environmental antigens the immune-defense systems are gradually built up_ This natural form of active immunization can be mimicked by a deliberate introduction of antigens into the host in order to provoke protective immune responses prior to a natural encounter with those antigens [Clark, 1991

Studies on the promotion of nickel—alumina coprecipitated catalysts: I. Titanium oxide

A series of TiO2-promoted nickel—alumina catalysts has been prepared and characterized. The promoter was added in various proportions to a calcined coprecipitated nickel—alumina material by adsorption of the acetylacetonate complex of titanium, followed by further calcination and reduction. The structure of the resultant materials was similar to that of the unpromoted coprecipitated nickel—alumina. The chemisorption properties of the catalyst and its behaviour in the CO/H2 reaction were characteristic of a strong metal-support interaction (SMSI) reported in the literature for Ni/TiO2. The strong adsorption of both carbon monoxide and hydrogen were suppressed while the activity for carbon monoxide hydrogenation was increased, the activation energy being lowered. The higher activity, however, was relatively unstable under reaction conditions

Modulation of systemic cytokine levels by implantation of alginate encapsulated cells

The availability of cell lines that are transfected with IL-4, IL-5 and IFN-γ cytokine genes permits the prolonged in vivo delivery of functional cytokines in relatively large doses for the modulation of specific immune responses. Oft

The Effect of IFN-γ, Alum and Complete Freund Adjuvant on TNP-KLH Induced Ig.G1, IgE and IgG2a Responses in Mice

Adjuvants are considered to play an important role in directing the isotype and amount of antibodies produced upon immunization by conducting the development of either Th-1 or Th-2 cells upon T-cell stimulation. This is based on the different cytokine production patterns that were observed after in vitro resttmulation of T cells isolated from mice immunized with antigen either adsorbed on alum or emulsified in complete Freund adjuvant (CFA). However, other studies suggest that primarily the type of antigen determines which isotypes are produced and to what extent. In these studies, however, IgE was not determined. Therefore, this study examined whether alum and CFA influenced the amount and/or ratio of IgG1, IgE and IgG2a produced after TNP-KLH immunization. Similar levels of IgG1, IgE and IgG2a antibodies were found upon immunization with TNP-KLH either adsorbed on alum or emulsified in CFA. Moreover, administration of IFN-γ in combination with TNP-KLH adsorbed on alum did not increase the amount of IgG2a produced. IFN-γ treatment resulted in an increased IL-6 and decreased IFN-γ production by spleen cells upon Con A stimulation, whereas it did not change the IL-4 production in similar conditions. The presented results suggest that upon immunization with TNP-KLH high IL-4 levels are produced, resulting in an antibody response that is dominated by IgG1, independent of the adjuvant employed. The IL-4 inducing property of TNP-KLH is substantiated by the finding that repeated immunization of mice with TNP-KI, without adjuvant, increases the serum total IgE level. The presented data suggest that the carrier part of TNP-KLH preferentially results in Th-2 cell activity after which the adjuvant merely enhances the antibody responses generated

Electrochemical deprotonation of phosphate on stainless steel

Voltammetric experiments performed in phosphate buffer at constant pH 8.0 on platinum and stainless steel revealed clear reduction currents, which were correlated to the concentrations of phosphate. On the basis of the reactions proposed previously, a model was elaborated, assuming that both H2PO4 and HPO4 2 underwent cathodic deprotonation, and including the acid–base equilibriums. A kinetic model was derived by analogy with the equations generally used for hydrogen evolution. Numerical fitting of the experimental data confirmed that the phosphate species may act as an efficient catalyst of hydrogen evolution via electrochemical deprotonation. This reaction may introduce an unexpected reversible pathway of hydrogen formation in the mechanisms of anaerobic corrosion. The possible new insights offered by the electrochemical deprotonation of phosphate in microbially influenced corrosion was finally discussed

The combined impact of urban heat island, thermal bridge effect of buildings and future climate change on the potential overwintering of Phlebotomus species in a Central European metropolis

Leishmaniasis is one of the most important emerging vector-borne diseases in Western Eurasia. Although winter minimum temperatures limit the present geographical distribution of the vector Phlebotomus species, the heat island effect of the cities and the anthropogenic heat emission together may provide the appropriate environment for the overwintering of sand flies. We studied the climate tempering effect of thermal bridges and the heat island effect in Budapest, Hungary. Thermal imaging was used to measure the heat surplus of heat bridges. The winter heat island effect of the city was evaluated by numerical analysis of the measurements of the Aqua sensor of satellite Terra. We found that the surface temperature of thermal bridges can be at least 3-7 °C higher than the surrounding environment. The heat emission of thermal bridges and the urban heat island effect together can cause at least 10 °C higher minimum ambient temperature in winter nights than the minimum temperature of the peri-urban areas. This milder micro-climate of the built environment can enable the potential overwintering of some important European Phlebotomus species. The anthropogenic heat emission of big cities may explain the observed isolated northward populations of Phlebotomus ariasi in Paris and Phlebotomus neglectus in the agglomeration of Budapest

Individual particle morphology, coatings, and impurities of black carbon aerosols in Antarctic ice and tropical rainfall

© 2016 American Geophysical Union. All Rights Reserved. Black carbon (BC) aerosols are a large source of climate warming, impact atmospheric chemistry, and are implicated in large-scale changes in atmospheric circulation. Inventories of BC emissions suggest significant changes in the global BC aerosol distribution due to human activity. However, little is known regarding BC's atmospheric distribution or aged particle characteristics before the twentieth century. Here we investigate the prevalence and structural properties of BC particles in Antarctic ice cores from 1759, 1838, and 1930 Common Era (C.E.) using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The study revealed an unexpected diversity in particle morphology, insoluble coatings, and association with metals. In addition to conventionally occurring BC aggregates, we observed single BC monomers, complex aggregates with internally, and externally mixed metal and mineral impurities, tar balls, and organonitrogen coatings. The results of the study show BC particles in the remote Antarctic atmosphere exhibit complexity that is unaccounted for in atmospheric models of BC