Study on the effects of nitrilotriproprionic acid and 4,5-dihydroxy-1,3-benzene disulphonate on the fractionation of beryllium in human serum using graphite furnace atomic absorption spectrometry

<p>Abstract</p> <p>Background</p> <p>Occupational exposure to beryllium may cause Chronic Beryllium Disease (CBD), a lung disorder initiated by an electrostatic interaction with the MHC class II human leukocyte antigen (HLA). Molecular studies have found a significant correlation between the electrostatic potential at the HLA-DP surface and disease susceptibility. CBD can therefore be treated by chelation therapy. In this work, we studied the effect of two complexing agents, nitrilotriproprionic acid (NTP) and 4,5-dihydroxy-1,3-benzene disulphonate (Tiron), on the fractionation of beryllium in human serum analysed by graphite furnace atomic absorption spectrometry (GFAAS).</p> <p>Results</p> <p>We found the average serum beryllium concentration of fourteen non-exposed individuals to be 0.53 (± 0.14) μg l^-1, with 21 (± 3)% of the beryllium mass bound to the low molecular weight fraction (LMW), and 79 (± 3)% bound to the high molecular weight fraction (HMW). The addition of Tiron increased the beryllium mass in the HMW fraction, while NTP was not seen to have any influence on the fractionation of beryllium between the two fractions. NTP was, however, shown to complex 94.5% of the Be mass in the LMW fraction. The beryllium GFAAS detection limit, calculated as three times the standard deviation of 10 replicates of the lowest standard (0.05 μg L^-1), was 6.0 (± 0.2) ng L^-1.</p> <p>Conclusion</p> <p>The concentration of beryllium or its fractionation in human serum was not affected by sex or smoking habit. On average, three quarters of the beryllium in serum were found in the HMW fraction. Of the two ligands tested, only Tiron was effective in mobilising beryllium under physiological conditions, thus increasing the Be content in the HMW fraction.</p

Post-traumatic anxiety associates with failure of the innate immune receptor TLR9 to evade the pro-inflammatory NFκB pathway

Post-traumatic anxiety notably involves inflammation, but its causes and functional significance are yet unclear. Here, we report that failure of the innate immune system Toll-like receptor 9 (TLR9) to limit inflammation is causally involved with anxiety-associated inflammation and that peripheral administration of specific oligonucleotide activators of TLR9 may prevent post-traumatic consequences in stressed mice. Suggesting involvement of NFκB-mediated enhancement of inflammatory reactions in the post-traumatic phenotype, we found association of serum interleukin-1β increases with symptoms severity and volumetric brain changes in post-traumatic stress disorder patients. In predator scent-stressed mice, the moderate NFκB-activating oligonucleotides mEN101 and its human ortholog BL-7040, but not the canonic NFκB activator oligonucleotide ODN1826, induced anxiolytic effects. In stressed mice, peripherally administered mEN101 prevented delayed stress-inducible serum interleukin-1β increases while limiting stress-characteristic hippocampal transcript modifications and the anxiety-induced EGR1-mediated neuronal activation. Attesting to the TLR9 specificity of this response, BL-7040 suppressed NFκB-mediated luciferase in transfected cells co-expressing TLR9, but not other TLRs. Furthermore, TLR9−/− mice were mEN101 and BL-7040 resistant and presented unprovoked anxiety-like behavior and anxiety-characteristic hippocampal transcripts. Our findings demonstrate functional relevance of TLR9 in protecting stressed mammals from overreacting to traumatic experiences and suggest using oligonucleotide-mediated peripheral TLR9 activation to potentiate the innate immune system and prevent post-traumatic inflammation and anxiety

Employment and work schedule are related to telomere length in women

This note advances knowledge of the threshold of prox-boundedness of a function; an important concern in the use of proximal point optimization algorithms and in determining the existence of the Moreau envelope of the function. In finite dimensions, we study general prox-bounded functions and then focus on some useful classes such as piecewise functions and Lipschitz continuous functions. The thresholds are explicitly determined when possible and bounds are established otherwise. Some calculus rules are constructed; we consider functions with known thresholds and find the thresholds of their sum and composition