Native LESA TWIMS-MSI:Spatial, Conformational, and Mass Analysis of Proteins and Protein Complexes

We have previously demonstrated native liquid extraction surface analysis (LESA) mass spectrometry imaging of small intact proteins in thin tissue sections. We also showed calculation of collision cross sections for specific proteins extracted from discrete locations in tissue by LESA traveling wave ion mobility spectrometry (TWIMS). Here, we demonstrate an integrated native LESA TWIMS mass spectrometry imaging (MSI) workflow, in which ion mobility separation is central to the imaging experiment and which provides spatial, conformational, and mass information on endogenous proteins in a single experiment. The approach was applied to MSI of a thin tissue section of mouse kidney. The results show that the benefits of integration of TWIMS include improved specificity of the ion images and the capacity to calculate collision cross sections for any protein or protein complex detected in any pixel (without a priori knowledge of the presence of the protein).</p

Systemic reduction in glutathione levels occurs in patients with primary open-angle glaucoma

PURPOSE. To assess the level of plasma glutathione in patients with untreated primary open-angle glaucoma. METHODS. Twenty-one patients with newly diagnosed primary open-angle glaucoma and 34 age- and gender-matched control subjects were subjected to a blood analysis to detect the level of circulating glutathione in its reduced and oxidized forms. The effect of age, gender, and systemic blood pressure on circulating glutathione levels was also analyzed. RESULTS. Age had a negative effect on the level of both reduced and total glutathione (P = 0.002, r = -0.52 and P = 0.002, r = -0.52, respectively) in control subjects but not in patients with glaucoma (P > 0.05, r = 0.27, and P > 0.05, r = 0.22, respectively). In the control group, men demonstrated higher levels of both reduced and total glutathione than did women (P = 0.024 and P = 0.032, respectively). After correction for age and gender influences on blood glutathione levels, patients with glaucoma exhibited significantly lower levels of reduced and total glutathione than did control subjects (P = 0.010, F = 7.24 and P = 0.006, F = 8.38, respectively). No differences between study groups were observed in either oxidized glutathione levels or redox index (P > 0.05, F = 0.50; and P > 0.05, F = 0.30, respectively). CONCLUSIONS. Patients with glaucoma exhibit low levels of circulating glutathione, suggesting a general compromise of the antioxidative defense. Copyright © Association for Research in Vision and Ophthalmology

Datasets of whole cell and mitochondrial oxysterols derived from THP-1, SH-SY5Y and human peripheral blood mononuclear cells using targeted metabolomics

The raw datasets of oxysterol quantifications from whole cell and mitochondrial fractions of THP-1 monocytes and macrophages, neuronal-like SH-SH5Y cells and human peripheral blood mononuclear cells are presented. Oxysterols were quantified using a new liquid chromatography-mass spectrometry (LC-MS) and multiple reaction monitoring analysis published in the article “A quantitative LC-MS/MS method for analysis of mitochondrial-specific oxysterol metabolism” in Redox Biology [1]. This method showed improved extraction efficiency and recovery of mono and dihydroxycholesterols from cellular matrix. The datasets derived from the three cell lines are included in the appendix. These datasets provide new information about the oxysterol distribution in THP-1 monocytes and macrophages, SH-SY5Y cells and peripheral blood mononuclear cells. These datasets can be used as a guide for oxysterol distribution in the three cell lines for future studies, and can used for future method optimization, and for comparison of oxysterol recovery with other analytical techniques

Investigating neuropsychological and reward-related deficits in a chronic corticosterone-induced model of depression

Chronic stress is a known risk factor for the development of major depression (MDD) and is commonly used to induce a depression-like phenotype in rodents. Similar phenotypic effects are also observed in rodents when treated chronically with the stress hormone corticosterone. In this study, we investigated the neuropsychological consequences of chronic corticosterone treatment in male rats using two translational rodent assays of affective bias, the judgement bias task (JBT) and affective bias test (ABT). We also used the reward learning assay (RLA) and sucrose preference test (SPT) to quantify reward-related behaviours. Negative biases in decision-making were observed in the chronic corticosterone-treated group but only when the treatment was given shortly before each behavioural session. The same dose of corticosterone, when given daily after completion of the behavioural session had no effects. Chronic corticosterone treatment did not potentiate negative affective biases in the ABT induced by either an acute pharmacological or stress manipulation but both reward learning and reward sensitivity were blunted. Analysis of the brain tissue from animals receiving chronic corticosterone found reduced hippocampal neurogenesis consistent with previous studies suggesting corticosterone-induced neurotrophic deficits. Taken together, these data suggest chronic corticosterone treatment induces neuropsychological effects related to changes in reward learning, memory and negative biases in decision making, but these decision-making biases depend on whether rewarding outcomes were experienced during the acute effects of the drug. These findings suggest an important interaction between psychological and biological factors resulting in negative biases in decision-making in this model

Data collection and storage in long-term ecological and evolutionary studies : The Mongoose 2000 system

Studying ecological and evolutionary processes in the natural world often requires research projects to follow multiple individuals in the wild over many years. These projects have provided significant advances but may also be hampered by needing to accurately and efficiently collect and store multiple streams of the data from multiple individuals concurrently. The increase in the availability and sophistication of portable computers (smartphones and tablets) and the applications that run on them has the potential to address many of these data collection and storage issues. In this paper we describe the challenges faced by one such long-term, individual-based research project: the Banded Mongoose Research Project in Uganda. We describe a system we have developed called Mongoose 2000 that utilises the potential of apps and portable computers to meet these challenges. We discuss the benefits and limitations of employing such a system in a long-term research project. The app and source code for the Mongoose 2000 system are freely available and we detail how it might be used to aid data collection and storage in other long-term individual-based projects.Peer reviewe

Dendritic cell phenotype in severe asthma reflects clinical responsiveness to glucocorticoids

Background: Subsets of patients with severe asthma remain symptomatic despite prolonged, high dosage glucocorticoid therapy. We hypothesised that the clinical glucocorticoid sensitivity of these asthmatics is reflected in differences in peripheral blood dendritic cell subsets.Objective: To compare peripheral blood leukocyte populations using flow cytometry at baseline and after 2 weeks of systemic glucocorticoid (steroid) treatment to identify immunological differences between steroid sensitive (SS) and steroid resistant (SR) asthmatics.Methods: Adult severe asthmatics (SS n=12; SR n=23) were assessed for their response to two weeks of therapy with oral prednisolone. Peripheral blood was obtained before and after therapy and stained for lymphocyte (CD3, CD19, CD4, CD8 and Foxp3) and dendritic cell markers (Lineage negative [CD3, CD14, CD16, CD19, CD20, CD56], HLA-DR+, CD304 CD11c, ILT3 and CD86).Results: A higher median frequency of myeloid DCs (mDCs) but not plasmacytoid DCs (pDCs) was observed in the blood of SR as compared to SS asthmatics (p=0.03). Glucocorticoid therapy significantly increased median B cell, but not T cell numbers in both cohorts, with a trend for increased numbers of Foxp3+ Tregs in SS (p=0.07), but not SR subjects. Oral prednisolone therapy significantly reduced the median numbers and frequencies of total DCs and pDCs in both SS and SR asthmatics. Interestingly the expression of HLA-DR and ILT3 was also reduced on pDCs in all patients. In contrast,therapy increased the median frequency of mDCs in SS, but reduced it in SR asthmatics.Conclusions: Myeloid DC frequency is elevated in SR compared with SS asthmatics, and mDC show a differential response to oral prednisolone therapy.<br/

Screen-time during the after-school period: a contextual perspective

Sedentary screen-time is an increasingly prevalent behaviour, associated with a range of adverse health outcomes. Sedentary time and screen-use increase during adolescence, making this age group a prime target for behaviour change interventions. Better understanding the context in which sedentary screen-behaviours occur is important for ensuring future interventions have maximum impact. This study aimed to describe the prevalence of adolescents’ sedentary screen-time in the after-school and weekday evening periods, and to examine associations between contextual factors (location within the home and who they were with) and after-school/evening screen-time. Time that UK adolescents (N = 204, aged 11 or 12 years, 61.4% girls) spent using various screens was measured using a detailed three-day time-use diary completed at home. Adolescents reported the start and end time for each screen-based activity, where they were, and who they were with. Weekday (Monday-Friday) data were analysed with a focus on the after-school (3–6 pm) and evening periods (6–10.45 pm). Young adolescents spend around a third of their weekday evening leisure-time using screens, with boys engaging in slightly more screen-use than girls. The majority of after-school and weekday evening time at home was spent with family or siblings, with less than 1% spent with friends. Adolescents who spent more time alone after school reported greater screen-use. Greater time spent at home, in the lounge (living room) or bedroom was associated with greater screen-use. These findings highlight the value of devising family-based health-promotion interventions which target after-school/leisure-time screen-use in an effort to reduce young adolescents’ sedentary recreational screen-time behaviours

Design and fabrication of 3-D printed conductive polymer structures for THz polarization control

In this paper, we numerically and experimentally demonstrate the inverse polarization effect in three-dimensional (3-D) printed polarizers for the frequency range of 0.5 - 2.7 THz. The polarizers simply consist of 3-D printed strip lines of conductive polylactic acid (CPLA, Proto-Pasta) and do not require a substrate or any further metallic deposition. The experimental and numerical results show that the proposed structure acts as a broadband polarizer between the range of 0.3 THz to 2.7 THz, in which the inverse polarization effect is clearly seen for frequencies above 0.5 THz. In the inverse polarization effect, the transmission of the transverse electric (TE) component exceeds that of the TM component, in contrast to the behavior of a typical wire-grid polarizer. We show how the performance of the polarizers depends on the spacing and thickness of the CPLA structure; extinction ratios higher than 20 dB are achieved. This is the first report using CPLA to fabricate THz polarizers, demonstrating the potential of using conductive polymers to design THz components efficiently and robustly

The potential of research drawing on clinical free text to bring benefits to patients in the United Kingdom: a systematic review of the literature

Background: The analysis of clinical free text from patient records for research has potential to contribute to the medical evidence base but access to clinical free text is frequently denied by data custodians who perceive that the privacy risks of data-sharing are too high. Engagement activities with patients and regulators, where views on the sharing of clinical free text data for research have been discussed, have identified that stakeholders would like to understand the potential clinical benefits that could be achieved if access to free text for clinical research were improved. We aimed to systematically review all UK research studies which used clinical free text and report direct or potential benefits to patients, synthesizing possible benefits into an easy to communicate taxonomy for public engagement and policy discussions. Methods: We conducted a systematic search for articles which reported primary research using clinical free text, drawn from UK health record databases, which reported a benefit or potential benefit for patients, actionable in a clinical environment or health service, and not solely methods development or data quality improvement. We screened eligible papers and thematically analyzed information about clinical benefits reported in the paper to create a taxonomy of benefits. Results: We identified 43 papers and derived five themes of benefits: health-care quality or services improvement, observational risk factor-outcome research, drug prescribing safety, case-finding for clinical trials, and development of clinical decision support. Five papers compared study quality with and without free text and found an improvement of accuracy when free text was included in analytical models. Conclusions: Findings will help stakeholders weigh the potential benefits of free text research against perceived risks to patient privacy. The taxonomy can be used to aid public and policy discussions, and identified studies could form a public-facing repository which will help the health-care text analysis research community better communicate the impact of their work

The Local Group dwarf Leo T: HI on the brink of star formation

We present Giant Meterwave Radio Telescope (GMRT) and Westerbork ynthesis Radio Telescope (WSRT) observations of the recently discovered Local Group dwarf galaxy, Leo T. The peak HI column density is measured to be 7x10^20 cm^-2, and the total HI mass is 2.8Xx10^5 Msun, based on a distance of 420 kpc. Leo T has both cold (~ 500 K) and warm (~ 6000 K) HI at its core, with a global velocity dispersion of 6.9 km/s, from which we derive a dynamical mass within the HI radius of 3.3x10^6 Msun, and a mass-to-light ratio of greater than 50. We calculate the Jeans mass from the radial profiles of the HI column density and velocity dispersion, and predict that the gas should be globally stable against star formation. This finding is inconsistent with the half light radius of Leo T, which extends to 170 pc, and indicates that local conditions must determine where star formation takes place. Leo T is not only the lowest luminosity galaxy with on-going star formation discovered to date, it is also the most dark matter dominated, gas-rich dwarf in the Local Group.Comment: 6 pages, 7 figures, accepted for publication in MNRAS on November 15th 2007, full resolution version at: http://www.ast.cam.ac.uk/~eryan/leot.pdf . Typographical error in sound speed equation has led to a new Figure 6 and minor changes to the tex