The impact of a high versus a low glycaemic index breakfast cereal meal on verbal episodic memory in healthy adolescents

In this study, healthy adolescents consumed a) a low glycaemic index (G.I.) breakfast cereal meal, or b) a high G.I. breakfast cereal meal, before completing a test of verbal episodic memory in which the memory materials were encoded under conditions of divided attention. Analysis of remembering/forgetting indices revealed that the High G.I. breakfast group remembered significantly more items relative to the Low G.I. breakfast group after a long delay. The superior performance observed in the High G.I. group, relative to the Low G.I. group, may be due to the additional glucose availability provided by the high G.I. meal at the time of memory encoding. This increased glucose availability may be necessary for effective encoding under dual task conditions

Identification of the Molecular Mechanism by which TLR Ligation and IFN-γ Synergize to Induce Mig

Monokine Induced by Interferon- (MIG), a CXC chemokine, is a potent inducer of T-cell chemotaxis and activation and has been implicated in the host response to viral infections and tumor immunity as well as in the pathogenesis of autoimmunity and transplant rejection. Although it is known that the Toll-Like Receptor-4 (TLR-4) ligand LPS synergizes with IFN-γ to induce MIG expression in macrophages, the molecular mechanisms responsible for the synergy have yet to be elucidated. We determined that the marked synergy between LPS and IFN-γ on MIG mRNA expression in mouse macrophages is a result of LPS-induced NF-κB and IFN-γ-induced STAT. The synergy was not dependent on new protein synthesis, was independent of TNF-α, and occurred at the level of gene transcription. We identified 2 NF-κB sites located at -154 and -129 of the MIG promoter proximal to the -responsive element that mediated this effect. Finally, we demonstrated that other TLR ligands (zymosan, double stranded RNA and CpG) synergized with IFN-γ to induce MIG in an NF-κB dependent fashion. These data emphasize the ability of bacterial and viral products to activate/modify immune responses and promote adaptive T cell immunity through the NF-κB pathway

The silicon supplement 'Monomethylsilanetriol' is safe and increases the body pool of silicon in healthy Pre-menopausal women.

BACKGROUND: Monomethylsilanetriol (MMST) has been used for decades as an oral silicon supplement for bone and connective tissue health, although there are no formal data on its in vivo utilisation or safety following sustained dosing. METHODS: To investigate whether MMST contributes to the body pool of silicon and, secondly, to establish its safety following 4 weeks' supplementation in humans, twenty-two healthy pre-menopausal women (22-38 years) were recruited and supplemented with MMST at the maximum daily recommended dose (10.5 mg Si/day) for 4 weeks in a double-blind, randomised, placebo-controlled, cross-over design (i.e. 8 weeks in total). Fasting serum and urine samples were collected at baseline and at the end of the 4-week supplementation/placebo periods for analysis of total silicon by inductively coupled plasma optical emission spectrometry, MMST by proton nuclear magnetic resonance spectroscopy and full serum biochemistry. Participants also reported on, by questionnaire, their health, well-being and quality of life at 0, 4 and 8 weeks. RESULTS: Overall, 4-weeks supplementation with MMST significantly increased total fasting Si concentrations in serum and urine (P ≤ 0.003; paired t-test). MMST was semi-quantifiable in serum and quantifiable in urine, but only accounted for ca. 50% and 10%, respectively, of the increased total-Si concentration. There were no reported adverse effects (i.e. changes to health and well-being) or serum biochemical changes with MMST versus placebo. CONCLUSIONS: Our data indicate that oral MMST is safe, is absorbed and undergoes sufficient metabolism in vivo to raise fasting serum silicon levels, consistent with other well absorbed forms of dietary silicon (e.g. orthosilicic acid). It thus appears to be a suitable silicon supplement

Synthesis of oxetane- and azetidine-containing spirocycles related to the 2,5-diketopiperazine framework

A simple two-step sequence is used to efficiently make novel spirocyclic analogues of the diketopiperazine nucleus. Conjugate addition of chiral α-amino esters to nitroalkenes, generated from oxetan-3-one or N-Boc-azetidin-3-one, followed by nitro group reduction provides, after spontaneous cyclization, the spirocycles in good overall yields. These rigid scaffolds can be functionalized by selective N-alkylations as well as by carbonyl reduction to the corresponding piperazines

Effectiveness of common household cleaning agents in reducing the viability of human influenza A/H1N1

In the event of an influenza pandemic, the majority of people infected will be nursed at home. It is therefore important to determine simple methods for limiting the spread of the virus within the home. The purpose of this work was to test a representative range of common household cleaning agents for their effectiveness at killing or reducing the viability of influenza A virus

Ultrasmall silica nanoparticles directly ligate the T cell receptor complex.

The impact of ultrasmall nanoparticles (<10-nm diameter) on the immune system is poorly understood. Recently, ultrasmall silica nanoparticles (USSN), which have gained increasing attention for therapeutic applications, were shown to stimulate T lymphocytes directly and at relatively low-exposure doses. Delineating underlying mechanisms and associated cell signaling will hasten therapeutic translation and is reported herein. Using competitive binding assays and molecular modeling, we established that the T cell receptor (TCR):CD3 complex is required for USSN-induced T cell activation, and that direct receptor complex-particle interactions are permitted both sterically and electrostatically. Activation is not limited to αβ TCR-bearing T cells since those with γδ TCR showed similar responses, implying that USSN mediate their effect by binding to extracellular domains of the flanking CD3 regions of the TCR complex. We confirmed that USSN initiated the signaling pathway immediately downstream of the TCR with rapid phosphorylation of both ζ-chain-associated protein 70 and linker for activation of T cells protein. However, T cell proliferation or IL-2 secretion were only triggered by USSN when costimulatory anti-CD28 or phorbate esters were present, demonstrating that the specific impact of USSN is in initiation of the primary, nuclear factor of activated T cells-pathway signaling from the TCR complex. Hence, we have established that USSN are partial agonists for the TCR complex because of induction of the primary T cell activation signal. Their ability to bind the TCR complex rapidly, and then to dissolve into benign orthosilicic acid, makes them an appealing option for therapies targeted at transient TCR:CD3 receptor binding.These studies were supported by grants from the UK Medical Research Council (Grant number MR/R005699/1) and the Natural Sciences and Engineering Research Council of Canada, as well as through sponsorship from HS Pharmaceuticals LLC

2D Cine DENSE with Low Encoding Frequencies Accurately Quantifies Cardiac Mechanics with Improved Image Characteristics

BACKGROUND: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. The encoding frequency (ke) maps the measured phase to tissue displacement while the strength of the encoding gradients affects image quality. 2D cine DENSE studies have used a ke of 0.10 cycles/mm, which is high enough to remove an artifact-generating echo from k-space, provide high sensitivity to tissue displacements, and dephase the blood pool. However, through-plane dephasing can remove the unwanted echo and dephase the blood pool without relying on high ke. Additionally, the high sensitivity comes with the costs of increased phase wrapping and intra-voxel dephasing. We hypothesized that ke below 0.10 cycles/mm can be used to improve image characteristics and provide accurate measures of cardiac mechanics. METHODS: Spiral cine DENSE images were obtained for 10 healthy subjects and 10 patients with a history of heart disease on a 3 T Siemens Trio. A mid-ventricular short-axis image was acquired with different ke: 0.02, 0.04, 0.06, 0.08, and 0.10 cycles/mm. Peak twist, circumferential strain, and radial strain were compared between acquisitions employing different ke using Bland-Altman analyses and coefficients of variation. The percentage of wrapped pixels in the phase images at end-systole was calculated for each ke. The dephasing of the blood signal and signal to noise ratio (SNR) were also calculated and compared. RESULTS: Negligible differences were seen in strains and twist for all ke between 0.04 and 0.10 cycles/mm. These differences were of the same magnitude as inter-test differences. Specifically, the acquisitions with 0.04 cycles/mm accurately quantified cardiac mechanics and had zero phase wrapping. Compared to 0.10 cycles/mm, the acquisitions with 0.04 cycles/mm had 9 % greater SNR and negligible differences in blood pool dephasing. CONCLUSIONS: For 2D cine DENSE with through-plane dephasing, the encoding frequency can be lowered to 0.04 cycles/mm without compromising the quantification of twist or strain. The amount of wrapping can be reduced with this lower value to greatly simplify the input to unwrapping algorithms. The strain and twist results from studies using different encoding frequencies can be directly compared

SENSE EPI reconstruction with 2D phase error correction and channel-wise noise removal

Nyquist ghost; Denoising; DiffusionFantasma de Nyquist; Eliminación de ruido; DifusiónFantasma de Nyquist; Eliminació de soroll; DifusióPurpose To develop a robust reconstruction pipeline for EPI data that enables 2D Nyquist phase error correction using sensitivity encoding without incurring major noise artifacts in low SNR data. Methods SENSE with 2D phase error correction (PEC-SENSE) was combined with channel-wise noise removal using Marcenko–Pastur principal component analysis (MPPCA) to simultaneously eliminate Nyquist ghost artifacts in EPI data and mitigate the noise amplification associated with phase correction using parallel imaging. The proposed pipeline (coined SPECTRE) was validated in phantom DW-EPI data using the accuracy and precision of diffusion metrics; ground truth values were obtained from data acquired with a spin echo readout. Results from the SPECTRE pipeline were compared against PEC-SENSE reconstructions with three alternate denoising strategies: (i) no denoising; (ii) denoising of magnitude data after image formation; (iii) denoising of complex data after image formation. SPECTRE was then tested using high -value (i.e., low SNR) diffusion data (up to  s/mm ) in four healthy subjects. Results Noise amplification associated with phase error correction incurred a 23% bias in phantom mean diffusivity (MD) measurements. Phantom MD estimates using the SPECTRE pipeline were within 8% of the ground truth value. In healthy volunteers, the SPECTRE pipeline visibly corrected Nyquist ghost artifacts and reduced associated noise amplification in high -value data. Conclusion The proposed reconstruction pipeline is effective in correcting low SNR data, and improves the accuracy and precision of derived diffusion metrics.EPSRC-funded UCL Centre for Doctoral Training in Medical Imaging, Grant/Award Number: EP/L016478/