Characterisation of microparticles and nitro-oxidative stress in cardiometabolic disease

Polycystic ovary syndrome (PCOS) is a common condition characterised by hyperandrogenism, oligo/anovulation and defects in insulin secretion and sensitivity. PCOS patients also have an increased prevalence of hypertension, dyslipidaemia and endothelial dysfunction, a state associated with decreased nitric oxide bioavailability and increased oxidative stress. Using women with PCOS as a model of predisposition to cardiovascular disease (CVD), the aim of this thesis was to provide a clearer understanding of mechanisms that may predispose individuals to endothelial dysfunction, and ultimately CVD. PCOS patients were compared to healthy controls in an observational study, which involved a comprehensive assessment of biochemical nitro-oxidative stress indices and a detailed characterisation of circulating microparticles (MPs). There was little evidence to suggest that women with PCOS have an increased oxidative stress compared to age/BMI-matched controls. However, PCOS patients did display elevated levels of annexin V positive MPs that were predominantly derived from platelets. In vitro studies investigated the effect of several metabolic stressors akin to those found in PCOS on endothelial-derived MP characteristics and function. Human endothelial (HECV) cells were exposed to oxidative, hypoxic, hyperandrogenic and metabolic stressors. Each metabolic stressor affected MP generation uniquely, suggesting MP characteristics and function reflect parental cell conditions. In order to determine whether circulating MP levels could be modulated in a clinical cohort, the effect of apheresis on circulating MP levels was investigated in patients with established CVD (familial hypercholesterolaemia). Apheresis decreased circulating levels of MPs and was associated with a decreased thrombin generation capacity in these patients. The data in this thesis thus provide evidence that young women with PCOS have an elevated concentration of annexin V positive MPs, even though there is little biochemical evidence for nitro-oxidative stress. Further studies are needed to assess the effect of this increase in circulating MPs on cardiovascular clinical end-points. In vitro experiments showed that the cellular stress condition is reflected in the MP characteristics, whereby each pathological stressor resulted in a unique MP phenotype. Furthermore, in patients with established CVD, apheresis reduced circulating levels of MPs. In conclusion, an elevated annexin V positive MP population may represent a novel mechanism by which cardiovascular risk is increased in patients with PCOS. These findings could have future implications for use as biomarkers, in diagnosis and therapeutics

Nitrate pharmacokinetics: taking note of the difference

Copyright © 2015 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Nitric Oxide: Biology and Chemistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Nitric Oxide: Biology and Chemistry (2015), DOI: 10.1016/j.niox.2015.04.006It is now recognised that administration of oral nitrate (NO3(-)), in its various forms, increases the level of nitric oxide (NO) metabolites in the circulation of humans. Its application to modulate physiology and alleviate cardiovascular dysfunction in some patients is now recorded and shows particular promise in hypertension, in modifying platelet activation/aggregation, and in conditions where tissue ischemia prevails. The potential of oral NO3(-) to modify exercise/performance via elevation of plasma nitrite concentration ([NO2(-)]) has been applied across a range of human test systems. Herein we discuss how the choice of NO3(-) source, route of administration and resulting pharmacokinetics might influence the outcome of physiological measures and potentially contribute to discrepancies in performance trials. There are but a few examples of detailed pharmacokinetic data on which the majority of researchers base their test protocols in different cohorts/settings. We compare and contrast the results of key publications with the aim of highlighting a consensus of our current understanding and critical considerations for those entering the field

Toward Exosome-Based Therapeutics: Isolation, Heterogeneity, and Fit-for-Purpose Potency

Exosomes are defined as submicron (30–150 nm), lipid bilayer-enclosed extracellular vesicles (EVs), specifically generated by the late endosomal compartment through fusion of multivesicular bodies with the plasma membrane. Produced by almost all cells, exosomes were originally considered to represent just a mechanism for jettisoning unwanted cellular moieties. Although this may be a major function in most cells, evolution has recruited the endosomal membrane-sorting pathway to duties beyond mere garbage disposal, one of the most notable examples being its cooption by retroviruses for the generation of Trojan virions. It is, therefore, tempting to speculate that certain cell types have evolved an exosome subclass active in intracellular communication. We term this EV subclass “signalosomes” and define them as exosomes that are produced by the “signaling” cells upon specific physiological or environmental cues and harbor cargo capable of modulating the programming of recipient cells. Our recent studies have established that signalosomes released by mesenchymal stem/stromal cells (MSCs) represent the main vector of MSC immunomodulation and therapeutic action in animal models of lung disease. The efficacy of MSC-exosome treatments in a number of preclinical models of cardiovascular and pulmonary disease supports the promise of application of exosome-based therapeutics across a wide range of pathologies within the near future. However, the full realization of exosome therapeutic potential has been hampered by the absence of standardization in EV isolation, and procedures for purification of signalosomes from the main exosome population. This is mainly due to immature methodologies for exosome isolation and characterization and our incomplete understanding of the specific characteristics and molecular composition of signalosomes. In addition, difficulties in defining metrics for potency of exosome preparations and the challenges of industrial scale-up and good manufacturing practice compliance have complicated smooth and timely transition to clinical development. In this manuscript, we focus on cell culture conditions, exosome harvesting, dosage, and exosome potency, providing some empirical guidance and perspectives on the challenges in bringing exosome-based therapies to clinic

Methodological pluralism in qualitative research: Reflections on a meta-study

A short report is provided of a meta-study of methodological pluralism in qualitative research; that is, of the use of two or more qualitative methods to analyse the same data set. Ten eligible papers were identified and assessed. Their contents are described with respect to theory, methods and findings, and their possible implications discussed in relation to a series of wider debates in qualitative research more generally

Elevation change, mass balance, dynamics and surging of Langjökull, Iceland from 1997 to 2007

ABSTRACTGlaciers and ice caps around the world are changing quickly, with surge-type behaviour superimposed upon climatic forcing. Here, we study Iceland's second largest ice cap, Langjökull, which has both surge- and non-surge-type outlets. By differencing elevation change with surface mass balance, we estimate the contribution of ice dynamics to elevation change. We use DEMs, in situ stake measurements, regional reanalyses and a mass-balance model to calculate the vertical ice velocity. Thus, we not only compare the geodetic, modelled and glaciological mass balances, but also map spatial variations in glacier dynamics. Maps of emergence and submergence velocity successfully highlight the 1998 surge and subsequent quiescence of one of Langjökull's outlets by visualizing both source and sink areas. In addition to observing the extent of traditional surge behaviour (i.e. mass transfer from the accumulation area to the ablation area followed by recharge of the source area), we see peripheral areas where the surge impinged upon an adjacent ridge and subsequently retreated. While mass balances are largely in good agreement, discrepancies between modelled and geodetic mass balance may be explained by inaccurate estimates of precipitation, saturated adiabatic lapse rate or degree-day factors. Nevertheless, the study was ultimately able to investigate dynamic surge behaviour in the absence of in situ measurements during the surge.In situ mass balance survey is a joint effort of the Glaciology Group, Institute of Earth Sciences, University of Iceland and the National Power Company (Landsvirkjun). We thank Philippe Crochet and Tómas Jóhannesson from the Icelandic Meteorological Office for providing the gridded climate data and for useful discussions about the climatology of Langjökull. The 2007 lidar data were collected by the UK Natural Environment Research Council Airborne Research and Survey Facility (Grant IPY 07-08). Additional funding was provided by the United States National Science Foundation (Grant No. DGE-1038596), St Catharine’s, St John’s and Trinity Colleges and the University of Cambridge B.B. Roberts and Scandinavian Studies Funds. We thank Cameron Rye for initial help coding the mass balance model.This is the author accepted manuscript. The final version is available from Cambridge University Press via https://doi.org/10.1017/jog.2016.5

Elevation Change, Mass Balance, Dynamics, and Surging of Langjökull, Iceland from 1997 to 2007

Glaciers and ice caps around the world are changing quickly, with surge-type behaviour superimposed upon climatic forcing. Here, we study Iceland’s second largest ice cap, Langjökull, which has both surge- and non-surge-type outlets. By differencing elevation change with surface mass balance, we estimate the contribution of ice dynamics to elevation change. We use DEMs, in situ stake measurements, regional reanalyses, and a mass balance model to calculate the vertical ice velocity. Thus, we not only compare the geodetic, modelled, and glaciological mass balances, but also map spatial variations in glacier dynamics. Maps of emergence and submergence velocity successfully highlight the 1998 surge and subsequent quiescence of one of Langjökull’s outlets by visualizing both source and sink areas. In addition to observing the extent of traditional surge behaviour (i.e., mass transfer from the accumulation area to the ablation area followed by recharge of the source area), we see peripheral areas where the surge impinged upon an adjacent ridge and subsequently retreated. While mass balances are largely in good agreement, discrepancies between modelled and geodetic mass balance may be explained by inaccurate estimates of precipitation, saturated adiabatic lapse rate, or degree day factors. Nevertheless, the study was ultimately able to investigate dynamic surge behaviour in the absence of in situ measurements during the surge.In situ mass balance survey is a joint effort of the Glaciology Group, Institute of Earth Sciences, University of Iceland and the National Power Company (Landsvirkjun). We thank Philippe Crochet and Tómas Jóhannesson from the Icelandic Meteorological Office for providing the gridded climate data and for useful discussions about the climatology of Langjökull. The 2007 lidar data were collected by the UK Natural Environment Research Council Airborne Research and Survey Facility (Grant IPY 07-08). Additional funding was provided by the United States National Science Foundation (Grant No. DGE-1038596), St Catharine’s, St John’s and Trinity Colleges and the University of Cambridge B.B. Roberts and Scandinavian Studies Funds. We thank Cameron Rye for initial help coding the mass balance model.This is the author accepted manuscript. The final version is available from Cambridge University Press via https://doi.org/10.1017/jog.2016.5

2008-2009 Mostly Music: Ravel

Date & Time: Saturday, January 24, 2009 at 7:30 pm & Sunday, January 25, 2009 at 4:00 pmhttps://spiral.lynn.edu/conservatory_mostlymusic/1004/thumbnail.jp

Doing gender locally: The importance of ‘place’ in understanding marginalised masculinities and young men’s transitions to ‘safe’ and successful futures

Observable anxieties have been developing about the position of boys and young men in contemporary society in recent years. This is expressed as a crisis of masculinity, in which place is often implicitly implicated, but is rarely considered for its role in the shaping of young men’s practices, trajectories and aspirations. Drawing on research conducted with young people who accessed a range of social care support services, this article argues that transition means different things for young men in different locales and that local definitions of masculinity are required to better understand young men’s lives and the opportunities available to them. The authors argue that home life, street life, individual neighbourhoods, regions and nations all shaped the young men’s identities and the practices they (and the staff working with them) drew on in order to create successful futures and ‘safe’ forms of masculinity. It is suggested that this place-based approach has the potential to re-shape the ‘crisis’ discourse surrounding masculinity and the anxieties associated with young men