Channel Catchments Cluster. Recent developments in tools and techniques for water quality management in the France (Channel) England region

The Channel Catchments Cluster (3C) aims to capitalise on outputs from some of the recent projects funded through the INTERREG IVa France (Channel) England programme. The river catchment basins draining into the Channel region drain an area of 137,000km2 and support a human population of over 19M. Throughout history, these catchments, rivers and estuaries have been centres of habitation, developed through commerce and industry, providing transport links to hinterland areas. These catchments also provide drinking water and food through provision of agriculture, fisheries and aquaculture. In addition, many parts of the region are also economically important now for the tourism and leisure industries. Consequently, there is a need to manage the balance of these many and varied human activities within the catchments, rivers, estuaries and marine areas to ensure that they are maintained or restored to good environmental condition . This document highlights some of the recent work carried out by projects within the INTERREG IVa programme that provide tools and techniques to assist in the achievement of these goals

Truncated human endothelin receptor A produced by alternative splicing and its expression in melanoma

In this study, reverse transcriptase polymerase chain reaction was used to amplify human endothelin receptor A (ETA) and ETB receptor mRNA. A truncated ETA receptor transcript with exons 3 and 4 skipped was found. The skipping of these two exons results in 109 amino acids being deleted from the receptor. The truncated receptor was expressed in all tissues and cells examined, but the level of expression varied. In melanoma cell lines and melanoma tissues, the truncated receptor gene was the major species, whereas the wild-type ETA was predominant in other tissues. A 1.9-kb ETA transcript was identified in melanoma cell lines by Northern blot, which was much smaller than the transcript in heart and in other tissues reported previously (4.3 kb). The cDNA coding regions of the truncated and wild-type ETA receptors were stably transfected into Chinese hamster ovary (CHO) cells. The truncated ETA receptor-transfected CHO cells did not show binding affinity to endothelin 1 (ET-1) or endothelin 3 (ET-3). The function and biological significance of this truncated ETA receptor is not clear, but it may have regulatory roles for cell responses to ETs

Sedentary Behavior and Cardiovascular Disease Risk: Mediating Mechanisms.

Sedentary behavior has a strong association with cardiovascular disease (CVD) risk, which may be independent of physical activity. To date, the mechanism(s) that mediate this relationship are poorly understood. We hypothesize that sedentary behavior modifies key hemodynamic, inflammatory, and metabolic processes resulting in impaired arterial health. Subsequently, these vascular impairments directly and indirectly contribute to the development of CVD

Relationship Between Sedentary Behavior and Physical Activity at Work and Cognition and Mood

Background: Sedentary behavior is negatively associated with cognition and mood. Adults often engage in high levels of sedentary behavior at work through sitting, which may impact productivity. Consequently, replacing sitting with standing and physical activity (PA) is recommended. However, the associations between sitting, standing, and PA at work and cognition and mood are unknown; this study, therefore, aimed to explore these relationships. Methods: A total of 75 healthy full-time workers (33 male, mean [SD]; 33.6 [10.4] y, 38 [7] work hr/wk) wore sedentary behavior (activPAL) and PA (SenseWear Pro) monitors for 7 days and recorded their work hours. The day after this monitoring period, participants completed cognitive tests (executive function, attention, and working memory) and mood questionnaires (affect, alert, content, and calm). Multiple linear regression analyses examined the associations between cognition and mood and the time spent sitting, standing, and in each PA intensity during work hours, weekday leisure time, and weekends. Results: Workplace sitting, standing, or PA were not significantly associated with cognition or mood (P > .05). No significant associations were observed between these variables during weekday leisure time or weekends (P > .05). Conclusions: In a cohort of healthy workers, workplace sitting, standing, and PA are not associated with cognition or mood. Further research in this population is needed, examining the influence of workplace behaviors on cognition and mood, because this will contribute to evidence-based workplace guidelines to increase productivity

Reproducibility of four frequently used local heating protocols to assess cutaneous microvascular function.

BACKGROUND: Skin microvascular responses to local heating are frequently used to assess microvascular function. Several local heating protocols have been developed, all varying slightly in execution. The aim of this study was to determine the inter-day reproducibility of the four most commonly used local heating protocols in healthy young subjects. METHODS: Fifteen, healthy males (28±5yrs, BMI 25±2kg/m(2)) attended two experimental trials 2-7days apart. During each trial, baseline and maximal thermally stimulated forearm skin responses were examined simultaneously at four sites on the dominant forearm using laser Doppler flowmetry (LDF). The following heating protocols were adopted: 1. Rapid 39°C (0.5°C/5s), 2. Rapid 42°C (0.5°C/5s) 3. Gradual 42°C (0.5°C/2min 30s) and 4. Slow 42°C (0.5°C/5min). The coefficient of variation (CV) was calculated for absolute flux, cutaneous vascular conductance (CVC; flux/mean arterial pressure, MAP) and CVC expressed as a percentage of maximal CVC at 44°C (%CVCmax) at three different time points; baseline (33°C), plateau (39/42°C) and maximal (44°C). RESULTS: Reproducibility of baseline flux, CVC and %CVCmax was 17-29% across all protocols. During the plateau, Rapid, Gradual and Slow 42°C demonstrated a reproducibility of 13-18% for flux and CVC and 5-11% for %CVCmax. However, Rapid 39°C demonstrated a lower reproducibility for flux, CVC and %CVCmax (all 21%). Reproducibility at 44°C was 12-15% for flux and CVC across all protocols. CONCLUSION: This is the first study examining inter-day reproducibility across four local heating protocols. The good-to-moderate reproducibility of the Rapid, Gradual and Slow 42°C protocols support their (simultaneous) use to assess microvascular function. Using Rapid 39°C may require a greater number of subjects to detect differences within subjects

Effect of different walking break strategies on superficial femoral artery endothelial function.

Breaking up prolonged sitting with physical activity (PA) breaks prevents conduit artery dysfunction. However, the optimal break strategy to achieve this, in terms of the frequency or duration of PA, is not known. This study assessed the effect of breaking up sitting with different PA break strategies on lower limb peripheral artery endothelial function. Fifteen participants (10 male, 35.8 ± 10.2 years, BMI: 25.5 ± 3.2 kg m-2 ) completed, on separate days, three 4-h conditions in a randomized order: (1) uninterrupted sitting (SIT), (2) sitting with 2-min light-intensity walking breaks every 30 min (2WALK), or (3) sitting with 8-min light-intensity walking breaks every 2 h (8WALK). At baseline and 4 h, superficial femoral artery function (flow-mediated dilation; FMD), blood flow, and shear rate (SR) were assessed using Doppler ultrasound. For each condition, the change in outcome variables was calculated and data were statistically analyzed using a linear mixed model. There was no significant main effect for the change in FMD (P = 0.564). A significant main effect was observed for the change in blood flow (P = 0.022), with post hoc analysis revealing a greater reduction during SIT (-42.7 ± 14.2 mL·min) compared to 8WALK (0.45 ± 17.7 mL·min; P = 0.012). There were no significant main effects for mean, antegrade, or retrograde SR (P > 0.05). Superficial femoral artery blood flow, but not FMD, was reduced following uninterrupted sitting. This decline in blood flow was prevented with longer duration, less frequent walking breaks rather than shorter, more frequent breaks suggesting the dose (duration and frequency) of PA may influence the prevention of sitting-induced decreases in blood flow

Are acute sitting-induced changes in inflammation and cerebrovascular function related to impaired mood and cognition?

Purpose: Sedentary behaviour is negatively associated with mood and cognition, yet how acute sitting contributes to these overall associations is unknown. Since sitting heightens inflammation and impairs cerebrovascular function, this study investigated the hypothesis that these sitting-induced changes are related to impaired mood and cognition. Methods: Twenty-five healthy desk workers (18 male, 28.3 ± 7.5 years, BMI: 24.2 ± 3.3 kg∙m-2) were recruited. During laboratory visit one, participants were familiarised with cognitive performance tests measuring executive function, attention and working memory. During laboratory visit two, participants completed 6 h of continuous, uninterrupted sitting. At baseline and after 6 h, serum markers of inflammation, middle cerebral artery blood flow velocity (MCAv), cerebrovascular carbon dioxide reactivity (CVR), dynamic cerebral autoregulation (CA), cognitive performance and mood (positive and negative affect, alert, contented and calm) were assessed. Data were analysed using paired-samples t tests and correlation analyses. Results: Following sitting, C-reactive protein (∆-1.0 µg/ml) and tissue plasminogen activator (∆-360.4 pg/ml) decreased (p  0.05). The observed changes in inflammation and cerebrovascular function were not related to changes in mood (p > 0.05). Conclusion: Alterations in inflammation or cerebrovascular function following six hours of prolonged, uninterrupted sitting are not related to the observed reductions in mood, indicating other mechanisms underlie the relationship between acute sitting and mood disturbances

Cerebral and peripheral vascular differences between pre- and post-menopausal women

Objective: Menopause is associated with lower peripheral vascular function however cerebrovascular responses to this time-period are unclear. We aimed to describe peripheral vascular and cerebrovascular differences between pre- and post-menopausal women. Methods: Fifty pre- and post-menopausal women (N=100) underwent assessments of cerebral blood flow, cerebrovascular reactivity and autoregulation, carotid artery reactivity, brachial and femoral artery flow-mediated dilation and carotid, brachial and femoral artery intima-media thickness. Comparisons were made between pre- and post-menopausal women followed by a secondary-analysis (N=20) between late-pre-menopausal women and those within five years of menopause using a general linear model. Results: Cerebral blood flow (-11 [-17, -4 cm/s]; p=0.03) and carotid reactivity (-2.3 [-4.3, - 0.3%] p=0.03) were lower post-menopause compared to pre-menopause while cerebrovascular reactivity and autoregulation did not differ (p>0.05). Post-menopausal women had a larger carotid (0.16 [0.13, 0.20 mm] p<0.001), brachial (0.07 [0.03, 0.11mm] p=0.004) and femoral artery intima-media-thickness (0.09 [0.05, 0.14 mm] p=0.04), alongside lower brachial (-2.3 [-3.9, -0.7%] p=0.004) and femoral artery flow-mediated dilation (-3.0 [-4.3, - 1.8 %] p<0.001). In the secondary-analysis, early-post-menopausal women had a lower femoral artery flow-mediated dilation (-1.9 [-3.9, -0.0 %] p=0.05) and larger carotid intimamedia-thickness (0.07 [0.00, 0.14 mm] p=0.03) compared to late-pre-menopausal women. Conclusions: Cerebral blood flow, carotid artery reactivity, peripheral vascular function and structure are negatively affected by age. Preliminary data indicates that femoral artery function and carotid artery structure may be potentially impaired in early-post-menopause compared with late-pre-menopause. These findings suggest that conduit arteries susceptible to atherosclerosis may be important targets for lifestyle intervention in early menopause

Alloactivation of naïve CD4⁺ CD8⁻ CD25⁺T regulatory cells: Expression of CD8α identifies potent suppressor cells that can promote transplant tolerance induction

Therapy with alloantigen-specific CD4+ CD25+ T regulatory cells (Treg) for induction of transplant tolerance is desirable, as naïve thymic Treg (tTreg) are not alloantigen-specific and are weak suppressor cells. Naïve tTreg from DA rats cultured with fully allogeneic PVG stimulator cells in the presence of rIL-2 express IFN-gamma receptor (IFNGR) and IL-12 receptor beta2 (IL-12Rβ2) and are more potent alloantigen-specific regulators that we call Ts1 cells. This study examined additional markers that could identify the activated alloantigen-specific Treg as a subpopulation within the CD4+ CD25+ Foxp3+ Treg. After culture of naïve DA CD4+ CD8− CD25+ T cells with rIL-2 and PVG alloantigen, or rIL-2 without alloantigen, CD8α was expressed on 10–20% and CD8β on <5% of these cells. These cells expressed ifngr and Il12rb2. CD8α+ cells had increased Ifngr that characterizes Ts1 cells as well was Irf4, a transcription factor induced by TCR activation. Proliferation induced by re-culture with rIL-12 and alloantigen was greater with CD4+ CD8α+ CD25+ Treg consistent with the CD8α+ cells expressing IL-12R. In MLC, the CD8α+ fraction suppressed responses against allogeneic stimulators more than the mixed Ts1 population, whereas the CD4+ CD8− CD25+ T cells were less potent. In an adoptive transfer assay, rIL-2 and alloantigen activated Treg suppress rejection at a ratio of 1:10 with naïve effector cells, whereas alloantigen and rIL-2 activated tTreg depleted of the CD8α+ cells were much less effective. This study demonstrated that expression of CD8α by rIL-2 and alloantigen activation of CD4+ CD8− CD25+ Foxp3+ T cells was a marker of activated and potent Treg that included alloantigen-specific Treg

Plasmodium vivax: paroxysm-associated lipids mediate leukocyte aggregation

<p>Abstract</p> <p>Background</p> <p>Paroxysms are recurrent febrile episodes, characteristic of <it>Plasmodium vivax </it>infections, which coincide with the rupture of schizont-infected erythrocytes in the patients' circulation. The present study describes the formation of prominent aggregates of leukocytes <it>in vitro </it>in the presence of parasite and host factors released during paroxysms.</p> <p>Methods</p> <p>Whole blood cells from uninfected malaria-naïve donors were incubated with plasma taken during a paroxysm or normal human plasma as a control and cell smears were observed under the microscope for the presence of leukocyte aggregates. Plasma factors involved in mediating the leukocyte aggregation were identified using immune depletion and reconstitution experiments. Furthermore, biochemical characterization was carried out to determine the chemical nature of the active moieties in plasma present during paroxysms.</p> <p>Results</p> <p>Leukocyte aggregates were seen exclusively when cells were incubated in plasma collected during a paroxysm. Immune depletion and reconstitution experiments revealed that the host cytokines TNF-alpha, GM-CSF, IL-6 and IL-10 and two lipid fractions of paroxysm plasma comprise the necessary and sufficient mediators of this phenomenon. The two lipid components of the paroxysm plasmas speculated to be of putative parasite origin, were a phospholipid-containing fraction and another containing cholesterol and triglycerides. The phospholipid fraction was dependent upon the presence of cytokines for its activity unlike the cholesterol/triglyceride-containing fraction which in the absence of added cytokines was much more active than the phospholipids fraction. The biological activity of the paroxysm plasmas from non-immune patients who presented with acute <it>P. vivax </it>infections was neutralized by immune sera raised against schizont extracts of either <it>P. vivax </it>or <it>Plasmodium falciparum</it>. However, immune sera against <it>P. vivax </it>were more effective than that against <it>P. falciparum </it>indicating that the parasite activity involved may be antigenically at least partially parasite species-specific.</p> <p>Conclusion</p> <p>Leukocyte aggregation was identified as associated with paroxysms in <it>P. vivax </it>infections. This phenomenon is mediated by plasma factors including host-derived cytokines and lipids of putative parasite origin. The characteristics of the phospholipid fraction in paroxysm plasma are congruent with those of the parasite-derived, TNF-inducing GPI moieties described by others. The more active cholesterol/triglyceride(s), however, represent a novel malarial toxin, which is a new class of biologically active lipid associated with the paroxysm of <it>P. vivax </it>malaria.</p