Recovery of phosphonate surface contaminants from glass using a simple vacuum extractor with a solid-phase microextraction fiber.

Recovery of chemical contaminants from fixed surfaces for analysis can be challenging, particularly if it is not possible to acquire a solid sample to be taken to the laboratory. A simple device is described that collects semi-volatile organic compounds from fixed surfaces by creating an enclosed volume over the surface, then generating a modest vacuum. A solid-phase microextraction (SPME) fiber is then inserted into the evacuated volume where it functions to sorb volatilized organic contaminants.

Activity-dependent γ-aminobutyric acid release controls brain cortical tissue slice metabolism.

Vigabatrin (γ-vinyl-GABA) is an irreversible inhibitor of the enzyme γ-aminobutyric acid (GABA) transaminase. It has been shown to increase levels of GABA in brain and result in increased release of GABA from nonsynaptic sources following activation. Here, we use a guinea pig cortical tissue slice model to identify the metabolic sequelae of vigabatrin when incubated with tissue slices alone or when the tissue slices were activated by ligands with targeted activating mechanisms.

Dynamic imaging of the effector immune response to listeria infection in vivo.

Host defense against the intracellular pathogen Listeria monocytogenes (Lm) requires innate and adaptive immunity. Here, we directly imaged immune cell dynamics at Lm foci established by dendritic cells in the subcapsular red pulp (scDC) using intravital microscopy. Blood borne Lm rapidly associated with scDC.

Support for nursing and midwifery students: a special case?

In order to address attrition amongst nursing and midwifery students, three Scottish universities were funded to employ Pastoral Care Support Advisers (PSA). This paper presents the findings of an evaluation which explored nursing and midwifery students' support needs and their experience of the PSA service. Telephone and focus group interviews were carried out with staff (n=14) and students (n=25).

Statistical integration of 1H NMR and MRS data from different biofluids and tissues enhances recovery of biological information from individuals with HIV-1 infection.

Nuclear magnetic resonance (NMR) spectroscopy is widely used in metabonomics studies, but optimal recovery of latent biological information requires increasingly sophisticated statistical methods to identify quantitative relationships within these often highly complex data sets. Statistical heterospectroscopy (SHY) extracts latent relationships between NMR and mass spectrometry (MS) data from the same samples. Here we extend this concept to identify novel metabolic correlations between different biofluids and tissues from the same individuals.

The N-ethyl-N-nitrosourea-induced Goldenticket mouse mutant reveals an essential function of Sting in the in vivo interferon response to Listeria monocytogenes and cyclic dinucleotides.

Type I interferons (IFNs) are central regulators of the innate and adaptive immune responses to viral and bacterial infections. Type I IFNs are induced upon cytosolic detection of microbial nucleic acids, including DNA, RNA, and the bacterial second messenger cyclic-di-GMP (c-di-GMP). In addition, a recent study demonstrated that the intracellular bacterial pathogen Listeria monocytogenes stimulates a type I IFN response due to cytosolic detection of bacterially secreted c-di-AMP.

Pyruvate carboxylation in different model systems studied by (13)C MRS.

Pyruvate carboxylation is of great importance in the brain since it is responsible for adding net carbons to the tricarboxylic acid cycle following removal of carbon backbone for synthesis of the two most abundant neurotransmitters, glutamate and GABA. Despite having such a pivotal role, there is still much uncertainty in the exact metabolic details about where and how this carbon is returned. Pyruvate carboxylation has been studied in various model systems of the brain and (13)C magnetic resonance spectroscopy is an excellent tool for doing this.

γ-Hydroxybutyrate and the GABAergic footprint: a metabolomic approach to unpicking the actions of GHB.

Gamma-hydroxybutyrate is found both naturally in the brain and self-administered as a drug of abuse. It has been reported to act at endogenous γ-hydroxybutyrate (GHB) receptors and GABA(B) receptors [GABA(B)R], and may also be metabolized to GABA. Here, the metabolic fingerprints of a range of concentrations of GHB were measured in brain cortical tissue slices and compared with those of ligands active at GHB and GABA-R using principal components analysis (PCA) to identify sites of GHB activity.

Intracavity parametric generation of nanosecond terahertz radiation using quasi-phase-matching.

We report the use of quasi-phase-matching techniques based on periodically-poled MgO:LiNbO(3) for the generation of nanosecond duration pulses of terahertz radiation in intracavity optical parametric oscillators. Multiple idler-waves are generated with temporal studies indicating that the initiating process is the expected parametric down-conversion, but followed by cascaded difference frequency generation. A number of grating geometries have been explored, revealing the presence of dual solutions for the quasi-phase-matching process in the general case.

Corpus callosum morphology and its relationship to cognitive function in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1) is associated with cognitive dysfunction and structural brain abnormalities such as an enlarged corpus callosum. This study aimed to determine the relationship between corpus callosum morphology and cognitive function in children with neurofibromatosis type 1 using quantitative neuroanatomic imaging techniques. Children with neurofibromatosis type 1 (n = 46) demonstrated a significantly larger total corpus callosum and corpus callosum index compared with control participants (n = 30).

Listeriolysin O is necessary and sufficient to induce autophagy during Listeria monocytogenes infection.

Background: Recent studies have suggested that autophagy is utilized by cells as a protective mechanism against Listeria monocytogenes infection.

Methodology/principal Findings: However we find autophagy has no measurable role in vacuolar escape and intracellular growth in primary cultured bone marrow derived macrophages (BMDMs) deficient for autophagy (atg5-/-). Nevertheless, we provide evidence that the pore forming activity of the cholesterol-dependent cytolysin listeriolysin O (LLO) can induce autophagy subsequent to infection by L.

Interaction of Cowpea mosaic virus (CPMV) nanoparticles with antigen presenting cells in vitro and in vivo.

Background: Plant viruses such as Cowpea mosaic virus (CPMV) are increasingly being developed for applications in nanobiotechnology including vaccine development because of their potential for producing large quantities of antigenic material in plant hosts. In order to improve efficacy of viral nanoparticles in these types of roles, an investigation of the individual cell types that interact with the particles is critical. In particular, it is important to understand the interactions of a potential vaccine with antigen presenting cells (APCs) of the immune system.

IGFBP-5 induces epithelial and fibroblast responses consistent with the fibrotic response.

Fibrosis involves activation of fibroblasts, increased production of collagen and fibronectin and transdifferentiation into contractile myofibroblasts. The process resembles aspects of wound-healing but remains unresolved and can be life-threatening when manifest in the kidneys, lungs and liver, in particular. The causes are largely unknown, but recent suggestions that repetitive micro-injury results in the eventual failure of epithelial cell repair due to replicative senescence are gaining favour.

Bootstrap quantification of cardiac pulsation artifact in DTI.

While several studies have shown the benefit of cardiac gating in diffusion MRI with single-shot EPI acquisition, cardiac gating is still not commonly used. This is probably because it requires additional time and many investigators may not be convinced that cardiac gating is worth the extra effort. Here, we tested a clinically feasible protocol with a minimal increase in scan time, and quantified the effect of cardiac gating under partial or full Fourier acquisition.

Rottlerin inhibits (Na+, K+)-ATPase activity in brain tissue and alters D-aspartate dependent redistribution of glutamate transporter GLAST in cultured astrocytes.

The naturally occurring toxin rottlerin has been used by other laboratories as a specific inhibitor of protein kinase C-delta (PKC-delta) to obtain evidence that the activity-dependent distribution of glutamate transporter GLAST is regulated by PKC-delta mediated phosphorylation. Using immunofluorescence labelling for GLAST and deconvolution microscopy we have observed that D-aspartate-induced redistribution of GLAST towards the plasma membranes of cultured astrocytes was abolished by rottlerin. In brain tissue in vitro, rottlerin reduced apparent activity of (Na+, K+)-dependent ATPase (Na+, K+-ATPase) and increased oxygen consumption in accordance with its known activity as an uncoupler of oxidative phosphorylation ("metabolic poison").

Dynamic changes in brain bioenergetics during obstructive sleep apnea.

Repetitive collapse of the upper airway during obstructive sleep apnea/hypopnea (OSA) exposes the brain of sufferers to frequent, transient, hypoxic episodes. The loss of cerebrovascular reactivity in sleep, and particularly in OSA, means that physiologic compensatory mechanisms may not ensure adequate brain oxygen levels. This (31)P magnetic resonance spectroscopy study, of 13 males with severe, untreated OSA undertaken after overnight sleep deprivation, represents the first, seconds time-scale analysis of human brain bioenergetics during transient hypoxia and demonstrates that a moderate degree of oxygen desaturation during sleep has significant effects on brain bioenergetic status.

Now I know my ABC. A systems neurochemistry and functional metabolomic approach to understanding the GABAergic system.

Here, we describe use of a reductionist brain model, the brain tissue slice, to generate snapshots of functional metabolism in response to a pharmacological (GABAergic) perturbation. Tissue slices prepared from Guinea pig cerebral cortex were incubated for 1 h in the presence of [3-13C]-pyruvate and ligands with affinity for GABA receptors. The resultant patterns of 13C flux and metabolite levels were measured by 13C/1H NMR spectroscopy, generating 'metabolic fingerprints' for each ligand.

Metabolic effects of blocking lactate transport in brain cortical tissue slices using an inhibitor specific to MCT1 and MCT2.

A novel inhibitor of lactate transport, AR-C122982, was used to study the effect of inhibiting the monocarboxylate transporters MCT1 and MCT2 on cortical brain slice metabolism. We studied metabolism of L-[3-13C]lactate, and D-[1-13C]glucose under a range of conditions. Experiments using L-[3-13C]lactate showed that the inhibitor AR-C122982 altered exchange of lactate.

Metabolite profiling of the intraerythrocytic malaria parasite Plasmodium falciparum by (1)H NMR spectroscopy.

NMR spectroscopy was used to identify and quantify compounds in extracts prepared from mature trophozoite-stage Plasmodium falciparum parasites isolated by saponin-permeabilisation of the host erythrocyte. One-dimensional (1)H NMR spectroscopy and four two-dimensional NMR techniques were used to identify more than 50 metabolites. The intracellular concentrations of over 40 metabolites were estimated from the (1)H NMR spectra of extracts prepared by four extraction methods: perchloric acid, methanol/water, methanol/chloroform/water, and methanol alone.

Understanding your inhibitions: effects of GABA and GABAA receptor modulation on brain cortical metabolism.

A targeted neuropharmacological, (1)H/(13)C NMR spectroscopy and multivariate statistical approach was used to examine the effects of exogenous GABA and ligands at the GABA(A) receptor family on brain metabolism in the Guinea pig cortical tissue slice. All ligands at GABA(A) receptors generated metabolic patterns which were distinct from one another with the major variance in the data arising because of metabolic work (shown by net flux into Krebs cycle byproducts and increased metabolic pool sizes). Three major clusters of metabolic signatures were identified which corresponded to: (i) activity at phasic (synaptic) GABA(A) receptors, dominated by alpha1-containing receptors and responsive to GABA at 10 micromol/L; (ii) activity at perisynaptic receptors, dominated by response to high (40 micromol/L) GABA and the superagonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol hydrochloride, and C, activity at extrasynaptic receptors, dominated by response to low (0.

Chemical addressability of ultraviolet-inactivated viral nanoparticles (VNPs).

Background: Cowpea Mosaic Virus (CPMV) is increasingly being used as a nanoparticle platform for multivalent display of molecules via chemical bioconjugation to the capsid surface. A growing variety of applications have employed the CPMV multivalent display technology including nanoblock chemistry, in vivo imaging, and materials science. CPMV nanoparticles can be inexpensively produced from experimentally infected cowpea plants at high yields and are extremely stable.

Induction of angiogenesis by murine resistin: putative role of PI3-kinase and NO-dependent pathways.

Unlabelled: Adipose tissue is a highly active endocrine organ, secreting bioactive molecules, adipokines, into the circulation. Obesity results in dysregulated adipokine secretion, contributing to pathophysiologies associated with this disorder, including insulin resistance and cardiovascular disease.

Objectives: To establish whether resistin, a novel bioactive molecule produced by murine adipose tissue, and implicated in insulin resistance in rodents, can induce angiogenic responses in aortic tissues and endothelial cells in vitro, and to investigate the signal transduction pathways involved in these responses.