Microglial Cell Activation Increases Saturated and Decreases Monounsaturated Fatty Acid Content,but Both Lipid Species are Proinflammatory

Neuroinflammation is a component of age-related neurodegenerative diseases and cognitive decline. Saturated (SFA) and monounsaturated (MUFA) fatty acids are bioactive molecules that may play different extrinsic and intrinsic roles in neuroinflammation, serving as exogenous ligands for cellular receptors, or endogenous components of cell structural, energetic and signaling pathways. We determined the fatty acyl profile of BV2 microglial cells before and after acute activation with lipopolysaccharide (LPS). We also investigated the effect of SFA and MUFA pretreatment on the production of an invasive, neurotoxic phenotype in BV2 cells. Acute activation of BV2 microglia resulted in an increase in the relative content of SFA (12:0, 16:0, 18:0, 20:0, 22:0, and 24:0 increased significantly), and a relative decrease in the content of MUFA (16:1n7, 18:1n7, 18:1n9, 20:1n9, 24:1n9 decreased significantly). In agreement, the major stearoyl-CoA desaturase (SCD) isoform in BV2 cells, SCD2, was significantly down-regulated by LPS. We next treated cells with SFA (16:0 or 18:0) or MUFA (16:1n7 or 18:1n9), and found that levels of secreted IL6 were increased, as was secreted MMP9-mediated proteolytic activity. To test the functional significance, we treated SH-SY5Y neuronal cells with conditioned medium from BV2 cells pretreated with fatty acids, and found a small but significant induction of cell death. Our findings suggest differential intrinsic roles for SFA and MUFA in activated microglial cells, but similar extrinsic roles for these fatty acid species in inducing activation. Expansion of SFA is important during microglial cell activation, but either supplemental SFA or MUFA may contribute to chronic low-grade neuroinflammation.     

Optimal Design of Blocked and Split-Plot Experiments for Fixed Effects and Variance Component Estimation

In general, modeling data from blocked and split-plot response surface experiments requires the use of generalized least squares and the estimation of two variance components. The literature on the optimal design of blocked and split-plot response surface experiments, however, focuses entirely on the precise estimation of the fixed factor effects and completely ignores the necessity to estimate the variance components as well. To overcome this problem, we propose a new Bayesian optimal design criterion which focuses on both the variance components and the fixed effects. A novel feature of the criterion is that it incorporates prior information about the variance components through log-normal or beta prior distributions. The resulting designs allow for a more powerful statistical inference than traditional optimal designs. In our algorithm for generating optimal blocked and split-plot designs, we implement efficient quadrature approaches for the numerical approximation of the new optimal design criterion. Supplementary materials for this article are available online.     

Closed‐Loop Transmit Diversity Techniques for Small Wireless Terminals and Their Performance Assessment in a Flat Fading Channel

Closed‐loop transmit diversity is considered an important technique for improving the link budget in the third generation and future wireless communication standards. This paper proposes several transmit diversity algorithms suitable for small wireless terminals and presents performance assessment in terms of average signal‐to‐noise ratio (SNR) and outage improvement, convergence, and complexity of operations. The algorithms presented herein are verified using data from measured indoor channels with variable antenna spacing and the results explained using measured radiation patterns for a two‐element array. It is shown that for a two‐element array, the best among the proposed techniques provides SNR improvement of about 3 dB in a tightly spaced array (inter‐element spacing of 0.1 wavelength at 2 GHz) typical of small wireless devices. Additionally, these techniques are shown to perform significantly better than a single antenna device in an indoor channel considering realistic values of latency and propagation errors.     

Removing peanut allergens by tannic acid

Tannic acid (TA) forms insoluble complexes with proteins. The aims here were to remove major peanut allergens as insoluble TA complexes and determine if they would dissociate and release the allergens at pH 2 and 8 (gut pH). Release of the allergens in the gut could lead to absorption and consequently an allergic reaction. TA (0.25, 0.5, 1, and 2 mg/ml) was added to a peanut butter extract (5 mg/ml; pH 7.2), stirred, and centrifuged. The precipitates were then suspended in buffer at pH 2, centrifuged, re-suspended at pH 8, and centrifuged. Supernatants from each step were analysed by SDS–PAGE, ELISA, and Western blots. The effect of NaCl (1 M) on complexes was also determined. Results showed that complexes formed at a TA concentration >0.5 mg/ml did not release major peanut allergens at pH 2 and 8, regardless of 1 M NaCl being present or not. IgE binding of the extracts was reduced substantially, especially at a TA concentration of 1–2 mg/ml. Animal or clinical studies are still needed before TA can find an application in the development of low-allergen peanut products/beverages or the removal of peanut allergens due to accidental ingestion.