Reduced length of nodes of Ranvier and altered proteoglycan immunoreactivity in prefrontal white matter in major depressive disorder and chronically stressed rats

Major depressive disorder (MDD) and chronic unpredictable stress (CUS) in animals feature comparable cellular and molecular disturbances that involve neurons and glial cells in gray and white matter (WM) in prefrontal brain areas. These same areas demonstrate disturbed connectivity with other brain regions in MDD and stress-related disorders. Functional connectivity ultimately depends on signal propagation along WM myelinated axons, and thus on the integrity of nodes of Ranvier (NRs) and their environment. Various glia-derived proteoglycans interact with NR axonal proteins to sustain NR function. It is unclear whether NR length and the content of associated proteoglycans is altered in prefrontal cortex (PFC) WM of human subjects with MDD and in experimentally stressed animals. The length of WM NRs in histological sections from the PFC of 10 controls and 10 MDD subjects, and from the PFC of control and CUS rats was measured. In addition, in WM of the same brain region, five proteoglycans, tenascin-R and NR protein neurofascin were immunostained or their levels measured with western blots. Analysis of covariance and t-tests were used for group comparisons. There was dramatic reduction of NR length in PFC WM in both MDD and CUS rats. Proteoglycan BRAL1 immunostaining was reduced at NRs and in overall WM of MDD subjects, as was versican in overall WM. Phosphacan immunostaining and levels were increased in both in MDD and CUS. Neurofascin immunostaining at NRs and in overall WM was significantly increased in MDD. Reduced length of NRs and increased phosphacan and neurocan in MDD and stressed animals suggest that morphological and proteoglycan changes at NRs in depression may be related to stress exposure and contribute to connectivity alterations. However, differences between MDD and CUS for some NR related markers may point to other mechanisms affecting the structure and function of NRs in MDD.

Increased SERCA2a sub-cellular heterogeneity in right-ventricular heart failure inhibits excitation-contraction coupling and modulates arrhythmogenic dynamics

The intracellular calcium handling system of cardiomyocytes is responsible for controlling excitation-contraction coupling (ECC) and has been linked to pro-arrhythmogenic cellular phenomena in conditions such as heart failure (HF). SERCA2a, responsible for intracellular uptake, is a primary regulator of calcium homeostasis, and remodelling of its function has been proposed as a causal factor underlying cellular and tissue dysfunction in disease. Whereas adaptations to the global (i.e. whole-cell) expression of SERCA2a have been previously investigated in the context of multiple diseases, the role of its spatial profile in the sub-cellular volume has yet to be elucidated. We present an approach to characterize the sub-cellular heterogeneity of SERCA2a and apply this approach to quantify adaptations to the length-scale of heterogeneity (the distance over which expression is correlated) associated with right-ventricular (RV)-HF. These characterizations informed simulations to predict the functional implications of this heterogeneity, and its remodelling in disease, on ECC, the dynamics of calcium-transient alternans and the emergence of spontaneous triggered activity. Image analysis reveals that RV-HF is associated with an increase in length-scale and its inter-cellular variability; simulations predict that this increase in length-scale can reduce ECC and critically modulate the vulnerability to both alternans and triggered activity. This article is part of the theme issue 'The cardiomyocyte: new revelations on the interplay between architecture and function in growth, health, and disease'.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Adolescents' dietary behaviour: The interplay between home and school food environments

In the UK, school food standards have looked to improve the nutritional profile of school food provision and the choices made; however, adolescents' choices tend to bias towards micronutrient poor and energy dense options. This study aimed to explore how adolescents make their school food choices, along with how they engage with their environments whilst selecting food. Seven focus group interviews took place with adolescents (n = 28; 13-14 years) in a secondary school in Northern England. Discussions with participants were audio-recorded, transcribed verbatim and then analysed using an inductive thematic approach. Six themes emerged from the data: (1) parents' and adolescents' roles in the home food environment, (2) burgeoning food autonomy, (3) school food choice factors, (4) social aspects of school food, (5) home versus school, (6) food knowledge & beliefs. Adolescents identified two distinct environments during the focus group discussions: the home and school environments. Adolescents juxtaposed the two, in terms of food provision, food choices, rules and customs surrounding food choice. This juxtaposition emerged as an indirect but important influence on adolescents' school food choices. The school and home environments both (in)directly influence adolescents' school food choices, which involve an integration of multiple, often conflicting influences. Adolescents may adopt a number of unhelpful dietary rationalisations as they try to manage and reconcile these influences. Consultation, together with consideration of relevant food choice models, is required to identify opportunities to influence adolescents' food choices at school.

O108 Central adiposity influences serum calcium concentrations and increases risk of kidney stone disease

Introduction

Serum calcium (SCa) and adiposity are associated with kidney stone disease (KSD). We used conventional and genetic epidemiological approaches to further understanding of these relationships.

Methods

Waist-hip ratio (WHR), a marker of central adiposity, SCa and KSD data were analysed by adjusted linear regression using UK Biobank participants. Univariable, multivariable and mediation Mendelian randomisation (MR) were undertaken using 316 and 246 genetic instruments for WHR and SCa, respectively.

Results

Observational analyses of 3,466 KSD cases and 489,944 controls showed that participants of normal BMI (20–25kg/m2) but in the fifth quintile for WHR have greater risk of incident KSD compared to the first quintile (HR=1.39 (95%CI=1.18–1.63)). After adjustment for sex, age, serum vitamin D, and phosphate, higher WHR was positively associated with SCa (ß=0.04, 95%=CI 0.04–0.05, P<0.001). Univariable MR demonstrated that relative risk of KSD increases with increasing WHR and SCa; 1 standard deviation (SD) increases relative risk by 46% (95%CI=1.27–1.67, P=5.9e-8) and 63% (95%CI=1.37–1.93, P=2.0E-8), respectively. A 1 SD increase in WHR increases SCa by 0.11mmol/L (95%CI=0.07–0.14, P=1.8e-8). Multivariable MR revealed that SCa and WHR independently increase KSD relative risk (OR=1.71, 95%CI=1.49–1.96, P<0.001 and OR=1.41, 95%CI=1.17–1.69, P<0.001 respectively). Mediation MR established that 14% of the effect of WHR on KSD risk is mediated via alterations in SCa.

Conclusion

Central adiposity is causally linked to KSD, partly by raising SCa. Mechanisms by which central adiposity increases KSD risk, independent of and via SCa, remain to be revealed and may identify novel therapeutic methods for KSD.

Take-home message

Central adiposity and serum calcium are independent, causal risk factors for kidney stone disease. One mechanism by which central obesity increases risk of kidney stone disease is by influencing serum calcium concentrations.

Estimated glucose disposal rate as a candidate biomarker for thrombotic biomarkers in T1D: a pooled analysis

PURPOSE

To determine the utility of estimated glucose disposal rate (eGDR) as a candidate biomarker for thrombotic biomarkers in patients with type 1 diabetes (T1D).

METHODS

We reanalysed baseline pretreatment data in a subset of patients with T1D from two previous RCTs, consisting of a panel of thrombotic markers, including fibrinogen, tissue factor (TF) activity, and plasminogen-activator inhibitor (PAI)-1, and TNFα, and clinical factors (age, T1D duration, HbA1c, insulin requirements, BMI, blood pressure, and eGDR). We employed univariate linear regression models to investigate associations between clinical parameters and eGDR with thrombotic biomarkers.

RESULTS

Thirty-two patients were included [mean ± SD age 31 ± 7 years, HbA1c of 58 ± 9 mmol/mol (7.5 ± 0.8%), eGDR 7.73 ± 2.61]. eGDR negatively associated with fibrinogen (P < 0.001), PAI-1 concentrations (P = 0.005), and TF activity (P = 0.020), but not TNFα levels (P = 0.881). We identified 2 clusters of patients displaying significantly different characteristics; 56% (n = 18) were categorised as 'higher-risk', eliciting significantly higher fibrinogen (+ 1514 ± 594 μg/mL; P < 0.001), TF activity (+ 59.23 ± 9.42 pmol/mL; P < 0.001), and PAI-1 (+ 8.48 ± 1.58 pmol/dL; P < 0.001), HbA1c concentrations (+ 14.20 ± 1.04 mmol/mol; P < 0.001), age (+ 7 ± 3 years; P < 0.001), duration of diabetes (15 ± 2 years; P < 0.001), BMI (+ 7.66 ± 2.61 kg/m²; P < 0.001), and lower mean eGDR (- 3.98 ± 1.07; P < 0.001).

CONCLUSIONS

Compared to BMI and insulin requirements, classical surrogates of insulin resistance, eGDR is a suitable and superior thrombotic risk indicator in T1D.

TRIAL REGISTRATION

ISRCTN4081115; registered 27 June 2017.

Effects of antibiotic treatment on antimicrobial resistance in pig microbiomes: a longitudinal study

 

The United Kingdom has prohibited the prophylactic use of antibiotics in agriculture but they are still critical for disease control. It is thus vital to understand the effects of antibiotic treatment on antimicrobial resistance (AMR) spread. Hi-C metagenomic sequencing can help identify AMR genes in animal microbiomes and assign plasmid-based genes to their bacterial hosts. Leveraging Hi-C, we sequence antibiotically-treated pig microbiomes through time to identify dynamic trends in AMR gene prevalence. Fecal samples were collected at time points prior to and following antibiotic treatment in 6 farms across England when pigs presented with illness. Control samples were collected from 2 of these farms at multiple time points without treatment. Samples were processed using a bioinformatic pipeline that outputs assemblies with information on taxonomic classification and presence/absence of an AMR allele. 115 AMR alleles across 11 antibiotic classes were included. The bacterial species in highest abundance/farm belonged to order Bacteroidales (45.9-53.1%). Tetracycline resistance alleles showed the highest prevalence/farm (28.4-52.8%). No significant association between bacterial species abundance and time point, and AMR allele prevalence and time point was found in all farms (χ2 p&gt;.05). The distribution of the number of AMR alleles/assembly was significantly higher between the first and last time point in 4/6 treated farms and 1/2 control farms (Wilcoxan rank sum p &lt;.01). A higher difference in the proportion of assemblies with greater than 6 AMR alleles between the first and last time point was observed in 1 treated farm (.17 95% CI .013-.21) compared to its control (.03 95% CI .023-.033). Slight acquisition of AMR alleles was observed but we see minimal temporal fluctuations in bacterial species abundance and AMR allele prevalence overall implying that the microbiome is fairly robust to antibiotic treatment. This encourages its responsible use for disease control.

Key messages

Ensuring that the responsible use of antibiotics does not drastically affect AMR mobilization is key to preserving the efficacy of therapeutics in agriculture. While acquisition of resistance genes over time is seen it cannot conclusively be tied to treatment; Minimal microbiome perturbation post treatment implies that therapeutic antibiotic use is warranted.

An economic evaluation of an intervention to increase demand for medical male circumcision among men aged 25-49 years in South Africa

BACKGROUND

Studies estimate that circumcising men between the ages of 20-30 years who have exhibited previous risky sexual behaviour could reduce overall HIV prevalence. Demand creation strategies for medical male circumcision (MMC) targeting men in this age group may significantly impact these prevalence rates.

OBJECTIVES

The objective of this study is to evaluate the cost-effectiveness and cost-benefit of an implementation science, pre-post study designed to increase the uptake of male circumcision for ages 25-49 at a fixed MMC clinic located in Gauteng Province, South Africa.

METHODS

A health care provider perspective was utilised to collect all costs. Costs were compared between the standard care scenario of routine outreach strategies and a full intervention strategy. Cost-effectiveness was measured as cost per mature man enrolled and cost per mature man circumcised. A cost-benefit analysis was employed by using the Bernoulli model to estimate the cases of HIV averted due to medical male circumcision (MMC), and subsequently translated to averted medical costs.

RESULTS

In the 2015 intervention, the cost of the intervention was $9445 for 722 men. The total HIV treatment costs averted due to the intervention were $542,491 from a public care model and $378,073 from a private care model. The benefit-cost ratio was 57.44 for the public care model and 40.03 for the private care model. The net savings of the intervention were $533,046 or $368,628 - depending on treatment in a public or private setting.

CONCLUSIONS

The intervention was cost-effective compared to similar MMC demand interventions and led to statistically significant cost savings per individual enrolled.

677 Quick, Simple and just as Effective – Comparing PM:L3 Ratio to NELA, P-POSSUM and NSQIP Scores for Emergency Laparotomy

Aim

Multiple tools (NELA, P-POSSUM, ACS-NSQIP) are available to assess mortality risks in patients requiring emergency laparotomy(1–3), but they are time-consuming to perform and have had limited uptake in routine clinical practice in many countries(4). Simpler measures, including psoas muscle:L3 vertebrae (PM:L3) ratio(5,6), may be useful alternates. This measure is quick to perform, requiring no special skills or equipment apart from basic CT viewing software.

Method

We performed an analysis on all patients in the Hunter Emergency Laparotomy Audit (HELA) database, from January 2016 to December 2017. HELA is a retrospective review of all emergency laparotomy undertaken in a discrete area in NSW, Australia. Patients with an available CT abdomen were included (N = 500/562). A single slice axial CT image at the L3 endplate level was analysed using ImageJ® software to measure the area of L3 and bilateral psoas muscles. This can be done using normal PACS software in routine practice.

Results

PM:L3 ratios in this cohort have a mean of 1.082 (95%CI 1.042-1.122; range 0.141-3.934). PM:L3 ratio is significantly lower (p &lt; 0.00001) in those patients who did not survive beyond 30 days (mean 0.865 [95% CI 0.746-0.984 ]) and 90 days (mean 0.888 [95%CI 0.768-1.008]) compared to patients that survived these periods (30 day mean 1.106 [95% vs. 1.033-1.179], 90 day mean 1.112 [95% CI 1.070-1.154]) . These associations are similar to those calculated by established risk assessment models.

Conclusions

PM:L3 ratio is a reliable, quick and easy risk assessment tool to identify high risk patients undergoing emergency laparotomy.

678 Can patients have their old life back? Using PM:L3 ratio to predict discharge destination of emergency laparotomy survivors

Aim

Psoas muscle:L3 vertebra (PM:L3) ratio is a relatively new risk assessment tool for emergency laparotomy(1,2) based upon the proven concept that sarcopenia – as diagnosed by low skeletal muscle index(3–6), psoas muscle density(7–9) or total psoas area(10–13) in a single axial slice CT image – correlates with increasing risks of bad outcomes in surgery. This study looks into the association between PM:L3 ratio of emergency laparotomy patients from home and their discharge destination.

Method

We performed an analysis on patients in the Hunter Emergency Laparotomy Audit (HELA) database, from January 2016 to December 2017. HELA is a retrospective review of all emergency laparotomy undertaken in a discrete area in NSW, Australia. All patients admitted from home, survived to be discharged from hospital and had an available CT abdomen were included (N = 433/562). A single slice axial CT image at the L3 endplate level was analysed using ImageJ® software to measure the area of L3 and bilateral psoas muscles.

Results

PM:L3 ratio is significantly lower in the group of patient discharged to a care facility than the group discharging back to their previous home residence (mean 0.951 vs. mean 1.128, p &lt; 0.001). Upon further analysis, the PM:L3s are divided into quartiles and stratified by sex. There is an association between lower PM:L3 and risk of discharging into a care facility (Q1 22.45%, Q2 19.59%, Q3 19.10%, Q4 5.71%).

Conclusions

PM:L3 ratio can predict the discharge destination of patients undergoing emergency laparotomy.

O20 Quick, simple and just as effective—comparing pm: L3 ratio to NELA, P-POSSUM and NSQIP scores in assessing mortality risk for emergency laparotomy

Introduction

Multiple tools (NELA, P-POSSUM, ACS-NSQIP) are available to assess mortality risks in patients requiring emergency laparotomy(1–3), but they are time-consuming to perform and have had limited uptake in routine clinical practice in many countries(4). Simpler measures, including psoas muscle: L3 vertebrae (PM: L3) ratio(5,6), may be useful alternates. This measure is quick to perform, requiring no special skills or equipment apart from basic CT viewing software.

Method

We performed an analysis on all patients in the Hunter Emergency Laparotomy Audit (HELA) database, from January 2016 to December 2017. HELA is a retrospective review of all emergency laparotomy undertaken in a discrete area in NSW, Australia. Patients with an available CT abdomen were included (N = 500/562). A single slice axial CT image at the L3 endplate level was analysed using ImageJ® software to measure the area of L3 and bilateral psoas muscles. This can be done using normal PACS software in routine practice.

Result

PM: L3 ratios in this cohort have a mean of 1.082 (95%CI 1.042–1.122; range 0.141–3.934). PM: L3 ratio is significantly lower (P &lt; 0.00001) in those patients who did not survive beyond 30 days (mean 0.865 [95% CI 0.746–0.984]) and 90 days (mean 0.888 [95%CI 0.768–1.008]) compared to patients that survived these periods (30 day mean 1.106 [95% vs. 1.033–1.179], 90 day mean 1.112 [95% CI 1.070–1.154]). These associations are similar to those calculated by established risk assessment models.

Conclusion

PM: L3 ratio is a reliable, quick and easy risk assessment tool to identify high risk patients undergoing emergency laparotomy.

Take-home Message

PM: L3 ratio is a reliable, quick and easy risk assessment tool to identify high risk patients undergoing emergency laparotomy. It is comparable to NELA, P-POSSUM and ACS-NSQIP.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

[Mitochondrial DNA copy number of leucocytes as ageing marker and risk factors for age-related diseases in human.]

We used quantitative real-time PCR method to analyse mtDNA copy number in a random subsample (n=996; 358 men aged 66,31±7,24 years; 468 women aged 67,62±7,1 years) selected from a population cohort (n=9 630) examined at baseline in international project HAPIEE in Novosibirsk, Russia, in 2003-2005. The participants were re-examined after 12 years in 2015-2017. The average relative number of mtDNA copies in peripheral blood leukocytes was greater in women than in men, independently of age and smoking (p=0,001). mtDNA copy number was inversely correlated with age both in men (p=0,005) and women (p<0,001). In age adjusted analysis, mtDNA copy number was inversely associated with waist, hip and heart rate in both sexes. In addition, mtDNA copy number in women was inversely associated with triglycerides and glucose, aterogenity index and positively with HDL cholesterol. In men, mtDNA copy number was positively associated with physical activity. The age-adjusted mean of mtDNA copy number among male never-smokers was greater than in smokers (p=0,003), and the mean mtDNA copy number was lower in women with diabetes than in women without diabetes (p=0,005). In both sexes, subjects with baseline history of hypertension had lower mtDNA copy number after 12-year follow-up than those without hypertension (p=0,05). This broadly supports the hypothesis that mtDNA copy number may act as biomarker of ageing.

BOS is associated with decreased HDAC2 from steroid resistant lymphocytes in the small airways

Immunosuppression therapies including corticosteroids fail to prevent bronchiolitis obliterans syndrome (BOS), primarily a disease of the small airways, following lung transplantation. We reported increases in steroid-resistant proinflammatory lymphocytes and their loss of histone deacetylase 2 (HDAC2), an important mediator of steroid action, in the blood of stable lung transplant recipients. We noted similar increases in the steroid-resistant lymphocytes in both the blood and small airways in BOS compared with the large airways. We hypothesized that these small airway cells would also exhibit a loss of HDAC2, and that these changes could be reversed by treatment with theophylline (HDAC2 activator). Blood, bronchoalveolar lavage and large and small airway brushings were collected from lung transplant patients with BOS (n = 12) or stable lung function (n = 18) and healthy aged-matched controls (n = 13). Intracellular proinflammatory cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF)-α and HDAC2 were measured in CD8⁺ T, natural killer (NK) T-like and NK cells from cultured small airway brushings ± 5 mg/l theophylline ± 1 µM prednisolone using flow cytometry. Increased small airway CD8 T, NK T-like and NK cells were identified in BOS versus stable transplant and controls. In BOS, these cells exhibited increased IFN-γ/TNF-α and a loss of HDAC2. HDAC2 expression by small airway CD8⁺ T cells correlated with forced expiratory volume in 1 s (FEV₁ ) (R = 0·880, P = 0·031). Theophylline and prednisolone synergistically up-regulated HDAC2 in CD8⁺ T cells. BOS is associated with loss of HDAC2 from steroid-resistant proinflammatory CD8⁺ T, NK T-like and NK cells in the small airways. Therapeutically increasing HDAC2 in these lymphocytes may reduce steroid resistance and improve graft survival.

Bronchiolitis obliterans syndrome is associated with increased p-glycoprotein expression and loss of glucocorticoid receptor from steroid-resistant proinflammatory CD8+ T cells

Immunosuppressive therapy fails to suppress the production of proinflammatory cytokines, particularly by CD8+ T cells, in stable lung transplant recipients and those undergoing chronic rejection, suggesting that some patients may become relatively resistant to immunosuppressants such as glucocorticoids (GC). We have shown loss of GC receptor (GCR) from the CD8+ cells, and we hypothesized that the drug membrane efflux pump, p-glycoprotein-1 (Pgp), may also be involved in lymphocyte steroid resistance following lung transplant. Pgp/GCR expression and interferon (IFN)-γ/tumour necrosis factor (TNF)-α proinflammatory cytokine production was measured in blood lymphocytes from 15 stable lung transplant patients, 10 patients with bronchiolitis obliterans syndrome (BOS) and 10 healthy aged-matched controls (± prednisolone ± Pgp inhibitor, cyclosporin A ± GCR activator, Compound A) using flow cytometry. Both Pgp+ and Pgp- lymphocyte subsets from all subjects produced IFN-γ/TNF-α proinflammatory cytokines. Pgp expression was increased in CD8+ Pgp+ T cells and correlated with IFN-γ/TNF-α expression and BOS grade. Reduced GCR was observed in CD8+ Pgp- T, natural killer (NK) T-like and NK cells from stable patients compared with controls, and reduced further in CD8+ Pgp- T cells in BOS. The addition of 2·5 ng/ml cyclosporin A and 1 µM prednisolone inhibit IFN-γ/TNF-α production significantly by CD8+ Pgp+ T cells from BOS patients. The addition of 10 µM Compound A and 1 µM prednisolone inhibit IFN-γ/TNF-α production significantly by CD8+ Pgp- T cells from BOS patients. BOS is associated with increased Pgp expression and loss of GCR from steroid-resistant proinflammatory CD8+ T cells. Treatments that inhibit Pgp and up-regulate GCR in CD8+ T cells may improve graft survival.

Occurrence and spatial distribution of chemical contaminants in edible fish species collected from UK and proximate marine waters

The occurrence of a range of regulated and emerging organic environmental contaminants was investigated in 182 samples of edible marine fish sampled mainly from UK marine regions, but extending northerly to the coast of Norway and south to the Algarve. These species (sprats, mackerel, turbot, halibut, herring, grey mullet, sea bass, grey mullet, sardines, etc.) are among those considered to be at the highest risk of contamination with regulated contaminants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, dioxins), and polychlorinated biphenyls (PCBs), but the occurrence of polybrominated diphenylethers (PBDEs) and polybrominated biphenyls (PBBs) was also investigated. Sub-sets of samples (50-75) were also analysed for emerging contaminants: polychlorinated naphthalenes (PCNs), polybrominated and mixed halogenated dibenzo-p-dioxins, dibenzofurans and biphenyls (PBDD/Fs, PXDD/Fs and PXBs) and perfluoroalkyl substances (PFAS). Contaminant occurrence varied with species and location, but all measured contaminants were detected, with sprats, sea bass, sardines, mackerel, and herring showing higher tissue concentrations. The concentrations of the different contaminants in the various samples were mapped utilising the GPS coordinate data of the capture locations to visualise spatial distribution levels. In terms of catch location, fish sampled from the coasts of southern Britain, north-western France and the Irish Sea appeared to contain proportionately higher levels of some contaminants - e.g. samples from the Irish Sea tended to show higher PCN concentrations, whereas higher levels of PCBs were observed in some fish sampled off the coasts of northern France. Similarly, samples of mullet from the southeast coast of UK showed much higher concentrations of BDE-99 than the other regions. In terms of occurrence trends, PCDD/F and PCB concentrations show a modest decline over the last decade but where limited background data is available for emerging contaminants, there is no evidence of downward trends.

Temperature dependence of the single photon emission from interface-fluctuation GaN quantum dots

The temperature dependent single photon emission statistics of interface-fluctuation GaN quantum dots are reported. Quantum light emission is confirmed at temperatures up to ~77 K, by which point the background emission degrades the emission purity and results in a measured g⁽²⁾ (0) in excess of 0.5. A discussion on the extent of the background contamination is also given through comparison to extensive data taken under various ambient and experimental conditions, revealing that the quantum dots themselves are emitting single photons with high purity.

The challenge of teaching undergraduates evidence-based veterinary medicine

The Royal College of Veterinary Surgeons now lists 'How to evaluate evidence' as a day one competence for newly qualified vets. In this article, representatives from each of the veterinary schools in the UK discuss how the challenge of delivering and assessing the concepts of evidence-based veterinary medicine in a crowded undergraduate curriculum can be met.

Observation of Reverse Saturable Absorption of an X-ray Laser

A nonlinear absorber in which the excited state absorption is larger than the ground state can undergo a process called reverse saturable absorption. It is a well-known phenomenon in laser physics in the optical regime, but is more difficult to generate in the x-ray regime, where fast nonradiative core electron transitions typically dominate the population kinetics during light matter interactions. Here, we report the first observation of decreasing x-ray transmission in a solid target pumped by intense x-ray free electron laser pulses. The measurement has been made below the K-absorption edge of aluminum, and the x-ray intensity ranges are 10^{16} -10^{17}  W/cm^{2}. It has been confirmed by collisional radiative population kinetic calculations, underscoring the fast spectral modulation of the x-ray pulses and charge states relevant to the absorption and transmission of x-ray photons. The processes shown through detailed simulations are consistent with reverse saturable absorption, which would be the first observation of this phenomena in the x-ray regime. These light matter interactions provide a unique opportunity to investigate optical transport properties in the extreme state of matters, as well as affording the potential to regulate ultrafast x-ray free-electron laser pulses.

Efficacy of a Probiotic-Prebiotic Supplement on Incidence of Diarrhea in a Dog Shelter: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Diarrhea is the most frequent morbidity affecting kenneled dogs in animal shelters. Diarrhea impacts animal welfare and the finances of the shelter as they must treat, clean, and house affected animals until recovered.

HYPOTHESIS/OBJECTIVES

Supplementing dogs entering an animal shelter with a probiotic-prebiotic, known as a synbiotic, will decrease the incidence of diarrhea.

ANIMALS

Seven hundred and seventy-three dogs entering an animal shelter in the United Kingdom.

METHODS

A prospective double-blind, randomized, placebo-controlled trial.

RESULTS

Statistical difference was found between the groups across 3 measures of diarrhea incidence. First, the mean percentage of scored days per dog that were scored as diarrhea throughout their stay was 2.0% in the synbiotic group and 3.2% in the placebo group (P = .0022). Second, the occurrence of diarrhea within the first 14 days' stay was 18.8% in the synbiotic product group and 27.2% in the placebo group (P = .0008). Third, the occurrence of ≥2 consecutive days of diarrhea within the first 14 days' stay was 4.6% in the synbiotic product group and 8.0% in the placebo group (P = .0300).

CONCLUSIONS AND CLINICAL IMPORTANCE

Supplementing healthy dogs entering an animal shelter with a synbiotic supplement significantly decreased the incidence of diarrhea in this trial. Animal shelters can use synbiotic supplements to improve animal welfare and decrease costs involved in cleaning and housing animals as well as potentially decreasing veterinary intervention.

Measurements of continuum lowering in solid-density plasmas created from elements and compounds

The effect of a dense plasma environment on the energy levels of an embedded ion is usually described in terms of the lowering of its continuum level. For strongly coupled plasmas, the phenomenon is intimately related to the equation of state; hence, an accurate treatment is crucial for most astrophysical and inertial-fusion applications, where the case of plasma mixtures is of particular interest. Here we present an experiment showing that the standard density-dependent analytical models are inadequate to describe solid-density plasmas at the temperatures studied, where the reduction of the binding energies for a given species is unaffected by the different plasma environment (ion density) in either the element or compounds of that species, and can be accurately estimated by calculations only involving the energy levels of an isolated neutral atom. The results have implications for the standard approaches to the equation of state calculations.

Saturable absorption of an x-ray free-electron-laser heated solid-density aluminum plasma

High-intensity x-ray pulses from an x-ray free-electron laser are used to heat and probe a solid-density aluminum sample. The photon-energy-dependent transmission of the heating beam is studied through the use of a photodiode. Saturable absorption is observed, with the resulting transmission differing significantly from the cold case, in good agreement with atomic-kinetics simulations.

X-ray transmission movies of spontaneous dynamic events

We describe a new x-ray radiographic imaging system which allows for continuous x-ray transmission imaging of spontaneous dynamic events. We demonstrate this method on thermal explosions in three plastic bonded formulations of the energetic material octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. We describe the x-ray imaging system and triggering developed to enable the continuous imaging of a thermal explosion.

Lung cancer is associated with decreased expression of perforin, granzyme B and interferon (IFN)-γ by infiltrating lung tissue T cells, natural killer (NK) T-like and NK cells

There is a limited understanding how of lung cancer cells evade cytotoxic attack. Previously, we have shown reduced production of the cytotoxic mediator granzyme B by CD8(+) T cells in lung cancer tissue. We hypothesized that lung cancer would be further associated with decreased production of granzyme B, perforin and proinflammatory cytokines by other cytotoxic lymphocytes, natural killer (NK) T-like and NK cells, and that this would result from soluble mediators released by the cancer cells. Lung cancer and non-cancer tissue from five patients was identified by experienced pathologists. Tumour necrosis factor (TNF)-α, interferon (IFN)-γ, granzyme B and perforin were measured in CD4 and CD8(+) T, NK T-like cells and NK cells by flow cytometry. Correlation between cancer stage and granzyme B was analysed retrospectively for 21 patients. The effects of soluble factors released by lung cancer cells on production of cytotoxic mediators and cytokines was assessed, and the role of prostaglandin E2 (PGE)2 /COX investigated using indomethacin inhibition. There were significantly decreased percentages of T, NK T-like and NK cells expressing perforin, TNF-α and IFN-γ in cancer versus non-cancer tissue, and of CD8(+) T cells and CD8(+) NK T-like cells expressing granzyme B (e.g. NK T-like cells: non-cancer 30% ± 7 versus cancer 6% ± 2·5). Cancer cells released soluble factors that inhibited granzyme B, perforin and IFN-γ production that was partially associated with the PGE2 /COX2 pathway. Thus, lung cancer is associated with decreased expression of granzyme B, perforin and IFN-γ by infiltrating T cells, NK T-like and NK cells, possibly as a result of soluble factors produced by the cancer cells including PGE2 . This may be an important immune evasion mechanism.

Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source

This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by using an absolute detector temporarily placed at the downstream end of the instrument. This provides an estimation of the reflectivity of all x-ray optical elements in the beamline and provides the absolute photon number per bandwidth per pulse. This parameter is important for many experiments that need to understand the trade-offs between high energy resolution and high flux, such as experiments focused on studying materials via resonant processes. Furthermore, the results are compared with the LCLS diagnostic gas detectors to test the limits of linearity, and observations are reported on radiation contamination from spontaneous undulator radiation and higher harmonic content.

Up-regulation of alternate co-stimulatory molecules on proinflammatory CD28null T cells in bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) is associated with lack of immunosuppression of T cell proinflammatory cytokines and increased T cell granzyme B. Repeated antigen-driven proliferation down-regulates T cell CD28. We hypothesized that down-regulation of CD28 and up-regulation of alternate co-stimulatory molecules (CD134, CD137, CD152 and CD154) on T cells may be associated with BOS. Co-stimulatory molecules, granzyme B, perforin and intracellular cytokines were measured by flow cytometry on T cells from stable lung transplant patients (n = 38), patients with BOS (n = 20) and healthy controls (n = 10). There was a significant increase in the percentage of CD4/28(null) and CD8/28(null) T cells producing granzyme B, interferon (IFN)-γ and tumour necrosis factor (TNF)-α in BOS compared with stable patients. Down-regulation of CD28 was associated with steroid resistance and up-regulation of CD134, CD137, CD152 and CD154 on CD4(+) T cells and CD137 and CD152 on CD8(+) T cells. There was a significant correlation between increased CD28(null) /CD137 T cells producing IFN-γ, TNF-α with BOS grade (r = 0·861, P < 0·001 for CD28(null) /CD137 IFN-γ/CD8) and time post-transplant (r = 0·698, P < 0·001 for CD28(null) /CD137 IFN-γ/CD8). BOS is associated with down-regulation of CD28 and up-regulation of alternate co-stimulatory molecules on steroid-resistant peripheral blood proinflammatory CD4(+) and CD8(+) T cells. Therapeutic targeting of alternate co-stimulatory molecules on peripheral blood CD28(null) T cells and monitoring response using these assays may help in the management of patients with BOS.

Measurement of an exciton Rabi rotation in a single GaN/Al(x)Ga(1-x)N nanowire-quantum dot using photoluminescence spectroscopy: evidence for coherent control

Experimental observation of excited state exciton Rabi rotation in a single GaN quantum dot is presented. The dot is embedded in a site-controlled GaN/AlGaN nanowire. Damped oscillation is observed in the power-dependent spectra of the quantum-dot ground state upon resonant pumping of an excited state that had been identified by photoluminescence excitation spectroscopy. A discussion on the origins of the damping is given.

Lessons and insights from ABO-incompatible lung transplantation

With ABO blood group incompatibility (ABOi) between donor and recipient becoming a part of mainstream living-donor renal transplantation, the applicability of ABOi to other areas of transplantation is being reconsidered. Here we present a case of inadvertent ABOi lung retransplantation managed successfully with initial plasmapheresis, antithymocyte globulin and intravenous immunoglobulin; and subsequently with oral cyclophosphamide and sirolimus in addition to tacrolimus and prednisolone. Interestingly, in the setting of solid levels of tacrolimus and sirolimus, the patient developed a fatal thrombotic microangiopathy of uncertain origin subsequent to the cessation of cyclophosphamide at 9 years posttransplant. It is apparent that ABOi lung transplantation can result in surprisingly successful long-term outcomes. Low pretransplant antibody titers likely aid this and, in pediatric neonatal or infant cases, this may not be uncommon. We must proceed cautiously as there are significant risks. Understanding the monitoring, prevention and treatment of lung transplant antibody-mediated rejection, while avoiding the long-term complications of overimmunosuppression, will be the keys to the success of future cases.

Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV

We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/c<p(T)<22 GeV/c, using a statistical method to subtract decay photons from the inclusive photon sample. The direct photon nuclear modification factor R(AA) was calculated as a function of p(T) for different Au+Au collision centralities using the measured p+p direct photon spectrum and compared to theoretical predictions. R(AA) was found to be consistent with unity for all centralities over the entire measured p(T) range. Theoretical models that account for modifications of initial direct photon production due to modified parton distribution functions in Au and the different isospin composition of the nuclei predict a modest change of R(AA) from unity. They are consistent with the data. Models with compensating effects of the quark-gluon plasma on high-energy photons, such as suppression of jet-fragmentation photons and induced-photon bremsstrahlung from partons traversing the medium, are also consistent with this measurement.