Immunotoxic, genotoxic, and endocrine disrupting impacts of polyamide microplastic particles and chemicals

Due to their exceptional properties and cost effectiveness, polyamides or nylons have emerged as widely used materials, revolutionizing diverse industries, including industrial 3D printing or additive manufacturing (AM). Powder-based AM technologies employ tonnes of polyamide microplastics to produce complex components every year. However, the lack of comprehensive toxicity assessment of particulate polyamides and polyamide-associated chemicals, especially in the light of the global microplastics crisis, calls for urgent action. This study investigated the physicochemical properties of polyamide-12 microplastics used in AM, and assessed a number of toxicity endpoints focusing on inflammation, immunometabolism, genotoxicity, aryl hydrocarbon receptor (AhR) activation, endocrine disruption, and cell morphology. Specifically, microplastics examination by means of field emission scanning electron microscopy revealed that work flow reuse of material created a fraction of smaller particles with an average size of 1-5 µm, a size range readily available for uptake by human cells. Moreover, chemical analysis by means of gas chromatography high-resolution mass spectrometry detected several polyamide-associated chemicals including starting material, plasticizer, thermal stabilizer/antioxidant, and migrating slip additive. Even if polyamide particles and chemicals did not induce an acute inflammatory response, repeated and prolonged exposure of human primary macrophages disclosed a steady increase in the levels of proinflammatory chemokine Interleukin-8 (IL-8/CXCL-8). Moreover, targeted metabolomics disclosed that polyamide particles modulated the kynurenine pathway and some of its key metabolites. The p53-responsive luciferase reporter gene assay showed that particles per se were able to activate p53, being indicative of a genotoxic stress. Polyamide-associated chemicals triggered moderate activation of AhR and elicited anti-androgenic activity. Finally, a high-throughput and non-targeted morphological profiling by Cell Painting assay outlined major sites of bioactivity of polyamide-associated chemicals and indicated putative mechanisms of toxicity in the cells. These findings reveal that the increasing use of polyamide microplastics may pose a potential health risk for the exposed individuals, and it merits more attention.

Is the mental health of older adults receiving care from their children related to their children's dual burden of caregiving and work stress? A linked lives perspective

OBJECTIVES

Mental health problems are a major concern in the older population in Sweden, as is the growing number of older adults aging alone in their homes and in need of informal care. Using a linked lives perspective, this study explored if older parents' mental health is related to their children's dual burden of informal caregiving and job strain.

METHODS

Data from a nationally representative Swedish survey, SWEOLD, were used. Mental health problems in older age (mean age 88) were measured with self-reported 'mild' or 'severe' anxiety and depressive symptoms. A primary caregiving adult child was linked to each older parent, and this child's occupation was matched with a job exposure matrix to assess job strain. Logistic regression analyses were conducted with an analytic sample of 334.

RESULTS

After adjusting for covariates, caregiving children's lower job control and greater job strain were each associated with mental health problems in their older parents (OR 2.52, p = 0.008 and OR 2.56, p = 0.044, respectively). No association was found between caregiving children's job demands and their older parents' mental health (OR 1.08, p = 0.799).

CONCLUSION

In line with the linked lives perspective, results highlight that the work-life balance of informal caregiving adult children may play a role in their older parent's mental health.

Per- and polyfluoroalkyl substances (PFAS) in sludge from wastewater treatment plants in Sweden - First findings of novel fluorinated copolymers in Europe including temporal analysis

Thousands of per- and polyfluoroalkyl substances (PFAS) are on the global market, while only a minor proportion is monitored regularly in the environment. Wastewater treatment plants (WWTPs) have been suggested to be a point source for PFAS to the environment due to emission of effluent and sludge. In this study, 81 PFAS including two rarely studied perfluoroalkyl sulfonamide-based (FASA) copolymers were analyzed in sludge samples to understand the usage of PFAS in the society. Sludge samples (n = 28) were collected at four WWTPs in Sweden between 2004 and 2017. The total levels of 79 measured PFAS were between 50 and 1124 ng/g d.w. All sludge samples showed detectable levels of both C8- and C4-FASA-based copolymers. The concentrations of the FASA-based copolymers were proposed to be reported in fluorinated side-chain equivalents (FSC eq.), in order to compare the levels of the copolymers with the other neutral and anionic PFAS, as no authentic standards were available. The concentrations of the FASA-based copolymers in sludge were between 1.4 and 22 ng FSC eq./g d.w. A general predomination of precursor and intermediate compounds was observed. A lower contribution of perfluoroalkyl carboxylic acids was noted for the WWTPs more influenced by domestic emission when compared with more influenced by industrial emission. An overall declining trend in the total PFAS concentration was seen between the years 2004 and 2017. The present study observed a shift from the C8-based chemistry toward shorter chain lengths, included a declining trend for C8-FASA-based copolymer over the entire study period. These findings further demonstrate the occurrence of side-chain fluorinated copolymers in Sweden and that sludge is a useful matrix to reflect the usage of PFAS in society and the potential for environmental exposure.

Analysis and characterization of novel fluorinated compounds used in surface treatments products

Side-chain fluorinated polymers are speculated to be potential precursors to other non-polymeric aliphatic per- and polyfluoroalkyl acids (PFAAs). Limited knowledge of environmental occurrence of this compound class is partly due to lack of structural information and authentic standards. In this study, two novel fluorinated compounds, suspected to be side-chain fluorinated copolymers used in two commercial technical mixtures (Scotchgard™ Pre-2002 formulation and Scotchgard™ Post-2002 formulation) were analyzed and characterized in order to provide information to facilitate detection and quantification. The commercial mixtures were analyzed using tandem mass spectrometry and high-resolution mass spectrometry; besides already reported C4- and C8-fluoroalkylsulfonamido (FASA) side-chains, a proposed structure was determined for the perfluorooctane (C8) sulfonamide-urethane copolymer in the Pre-2002 formulation. Structural isomers were also observed for C4- and C8-FASA-based copolymers. Total fluorine analysis revealed that the Scotchgard™ Pre-2002 Formulation contained a fluorine content of 0.5% and 1.8% for the Scotchgard™ Post-2002 Formulation. The equivalent FASA side-chain content was determined to be 0.8% for Pre-2002 and 3.1% for Post-2002. Both C4- and C8-FASA-based copolymers underwent hydrolysis and oxidation and were transformed to their respective perfluoroalkyl side chain, which suggest that transformation products can be analyzed for example after total oxidizable precursor (TOP) assay. Both compounds were shown to strongly sorb to sediment particles, which also gives indications about their environmental fate and transport pathways.

Examination of aryl hydrocarbon receptor (AhR), estrogenic and anti-androgenic activities, and levels of polyaromatic compounds (PACs) in tire granulates using in vitro bioassays and chemical analysis

Tire granulates recovered from end-of-life tires contain a complex mixture of chemicals, amongst them polyaromatic compounds (PACs), of which many are recognized to be toxic and persistent in the environment. Only a few of these PACs are regularly monitored. In this study a combined approach of chemical analysis and a battery of CALUX® in vitro bioassays was used to determine PAC concentrations and estrogenic, (anti)-androgenic and aryl hydrocarbon receptor (AhR) activities in tire granulates. Tire granulates from a recycling company was analyzed for PAHs, alkyl-PAHs, oxy-PAHs and heterocyclic PACs (NSO-PACs), in total 85 PACs. The concentrations of PACs were between 42 and 144 mg/kg, with major contribution from PAHs (74-88%) followed by alkyl-PAHs (6.6-20%) and NSO-PACs (1.8-7.0%). The sum of eight priority PAHs were between 2.3 and 8.6 mg/kg, contributing with 4.7-8.2% of ∑PACs. Bioassay analysis showed presence of AhR agonists, estrogen receptor (ERα) agonists, and androgen receptor (AR) antagonists in the tire granulate samples. Only 0.8-2.4% of AhR-mediated activities could be explained by the chemical analysis. Benzo[k+j]fluoranthenes, benzo[b]fluoranthene, indeno[1,2,3-cd]pyrene, 2-methylchrysene, and 3-methylchrysene were the major contributors to the AhR-mediated activities. The high contribution (98-99%) of unknown bioactive compounds to the bioassay effects in this study raises concerns and urges for further investigations of toxicants identification and source apportionment.

Extractable organofluorine analysis: A way to screen for elevated per- and polyfluoroalkyl substance contamination in humans?

The ubiquitous occurrence of a few per- and polyfluoroalkyl substances (PFAS) in humans and the environment has been previously reported. However, the number of PFAS humans and the environment are potentially exposed to is much higher, making it difficult to investigate every sample in detail. More importantly, recent studies have shown an increasing fraction of potentially unknown PFAS in human samples. A screening tool for identifying samples of concern that may contain high PFAS levels, to be studied more thoroughly, is needed. This study presents a simplified workflow to detect elevated PFAS levels using extractable organofluorine (EOF) analysis. A fluorine mass balance analysis on samples with high EOF, targeting 63 PFAS, can then confirm the PFAS contamination. Whole blood samples from a cohort of individuals with historical drinking water contamination from firefighting foams (n = 20) in Ronneby (Sweden) and a control group (n = 9) with background exposure were used as a case study. The average EOF concentration in the Ronneby group was 234 ng/mLF (<107-592 ng/mLF) vs 24.8 ng/mLF (17.6-37.8 ng/mL F) in the control group. The large difference (statistically significant, p < 0.05) in the EOF levels between the exposed and control groups would have made it possible to identify samples with high PFAS exposure only using EOF data. This was confirmed by target analysis, which found an average ∑PFAS concentration of 346 ng/mL in the exposed group and 7.9 ng/mL in the control group. The limit of quantification for EOF analysis (up to 107 ng/mLF using 0.5 mL whole blood) did not allow for the detection of PFAS levels in low or sub parts per billion (ng/mL) concentrations, but the results indicate that EOF analysis is a suitable screening method sensitive enough to detect elevated/significant/exposure above background levels by known or unknown PFAS.

High incidence of inappropriate alarms in patients with wearable cardioverter-defibrillators: findings from the swiss WCD registry

Introduction

The wearable cardioverter defibrillator (WCD) uses surface electrodes built into the vest to detect underlying arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts.

Purpose

The aim of this study was to assess the alarm burden in patients and its possible impact on clinical outcomes.

Methods

The Swiss WCD Registry is a nationwide, retrospective, observational registry. Patients were included from December 2011 until February 2018. Clinical characteristics and data from the WCDs, including alarm burden were analysed. Recordings ≥30 seconds of length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia or artefact.

Results

A total of 10'653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0±1.6 months. Among these, the episode duration was 30 seconds or more in 2996 (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate arrhythmia detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) supraventricular tachycardia). Two-hundred and seven patients (45.0%) had 3 or more alarms per month, whereas 49 patients (10.7%) had 1 or more alarms per day. Body mass index (BMI) was significantly higher in patients with 3 or more alarms per month (p=0.002, 25.6 vs. 27.3 kg/m2) High alarm burden was not associated with a lower average daily wear time (20.8 hours vs 20.7 hours, p=0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs 47.3%, p=0.156).

Conclusions

In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden did not lead to a decreased adherence, as determined by average daily wear-times. Obesity was significantly associated with a higher alarm burden.

Funding Acknowledgement

Type of funding sources: None.

Organofluorine Mass Balance Analysis of Whole Blood Samples in Relation to Gender and Age

Studies have highlighted the increasing fraction of unidentified organofluorine (UOF) compounds in human blood, whose health effects are not known. In this study, 130 whole blood samples from the Swedish general population were analyzed for extractable organofluorine (EOF) and selected per- and polyfluoroalkyl substances (PFAS). Organofluorine mass balance analysis revealed that 60% (0-99%) of the EOF in female samples could not be explained by the 63 monitored PFAS; in males, 41% (0-93%) of the EOF was of unidentified origin. Significant differences between both age groups and gender were seen, with the highest fraction of UOF in young females (70% UOF, aged 18-44), which is contrary to what has been reported in the literature for commonly monitored compounds (e.g., perfluorooctane sulfonic acid, PFOS). Increasing the number of monitored PFAS did not lead to a large decrease of the UOF fraction; the seven highest PFAS (C8-C11 PFCAs, C6-C8 PFSAs) accounted for 98% of sum 63 PFAS. The high fraction of UOF in human samples is of concern, as the chemical species of these organofluorine compounds remain unknown and thus their potential health risks cannot be assessed.

Combustion ion chromatography for extractable organofluorine analysis

Combustion ion chromatography (CIC) has found a role in environmental analytical chemistry for fluorine content analysis. It is used for extractable organofluorine (EOF) analysis to evaluate perfluoroalkyl and polyfluoroalkyl substances (PFASs) and other organofluorine burden. The prevailing assumption has been that all PFASs are incinerated in CIC and matrix components have no impact on this process, but this has not been experimentally evaluated. In this work, the combustion efficiencies of 13 different PFASs were determined (66–110%). A notable difference was observed between calibrating the CIC with inorganic fluorine or organofluorine. Potential interferences from cations and coextracted matrix components from whole blood and surface water samples were evaluated. These observations should be acknowledged when performing EOF analysis using CIC, overlooking either non-100% combustion efficiencies or the differences in calibrating the CIC with inorganic fluorine or organofluorine could lead to underestimating EOF content and through that to misguide policy decisions.

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Combustion efficiencies of PFASs were in the range of 66–110%

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There was difference between calibration with inorganic fluorine and organofluorine

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Matrix had no discernable effect on combustion efficiency

Short intense psychological stress induced by skydiving does not impair intestinal barrier function

Background and aim

Psychological stress has been shown to increase intestinal permeability and is associated with the development of gastrointestinal disorders. This study aimed to investigate skydiving as an alternative model to analyse the effect of acute psychological stress on intestinal barrier function.

Materials and methods

Twenty healthy subjects participated in a tandem skydive followed by a negative control visit, of which 19 (9 females and 10 males, 25.9 ± 3.7 years) were included in the study. Intestinal permeability was assessed by a multi-sugar urinary recovery test. Sucrose recovery and lactulose/rhamnose ratio in 0-5h urine indicated gastroduodenal and small intestinal permeability, respectively, and sucralose/erythritol ratio in 5-24h urine indicated colonic permeability. Blood samples were taken to assess markers associated with barrier function. This study has been registered at ClinicalTrials.gov (NCT03644979) on August 23, 2018.

Results

Skydiving resulted in a significant increase in salivary cortisol levels directly after skydiving compared to the control visit. Cortisol levels were still increased two hours after landing, while cortisol levels before skydiving were not significantly different from the baseline at the control visit. Skydiving did not induce a significant increase in gastroduodenal, small intestinal or colonic permeability. There was also no significant increase in plasma intestinal and liver fatty acid-binding proteins, suggesting no damage to the enterocytes.

Discussion

These results show that the acute intense psychological stress induced by skydiving does not affect intestinal permeability in healthy subjects. Future models aiming to investigate the effect of stress on human intestinal barrier function should consider a more sustained exposure to the psychological stressor.

IL-23 promotes T-cell mediated cardiac inflammation but protects the heart from fibrosis

Introduction

Cardiac inflammation varies widely and, in some cases, triggers autoimmune myocarditis and further inflammatory dilated cardiomyopathy (iDCM) and heart failure. In children, myocarditis leads to cardiomyopathy in almost half of affected individuals and up to 20% of sudden death cases in young adults have been reported to be due to myocarditis. IL-12 and IL-23 belong to the same family of cytokines known to mediate inflammatory conditions. Both regulate the differentiation of T cells: IL-12 promotes towards IFN-gamma-producing Th-1 cells, while IL-23 induces IL-17-producing Th-17 cells. Heart-reactive CD4+Th17 cells play a leading role in the development of myocarditis, however, literature reports excessiveness of IL-23 in Th17-derived IL-17 production. Therapeutic strategies blocking IL-23 were suggested as a promising approach, though the specific role of IL-23 in pathogenesis is unclear and the long-term perspectives stay elusive.

Purpose

We aim to explore the role IL-23 compared to IL-12 in the manifestation of cardiac autoimmune myocarditis.

Methodology

We use dendritic cell (DC) model of experimental autoimmune myocarditis in IL-12 and IL-23-deficient mice. Mice were injected with bone marrow-derived in vitro activated and loaded with cardiac-specific peptide DCs. This model mimics natural processes taking place during heart inflammation and provides a unique method to address the role of DCs-derived cytokines. Cardiac inflammation, as well as remodeling and heart function, were analysed at the acute and chronic stages of the disease.

Results

Surprisingly, all mice developed acute myocarditis, though wt receiving IL-23−/−bmDCs showed a twofold decrease in heart-infiltrating T cells and lower numbers of Th17 population. Further decrease of heart-infiltrating T cells appeared upon total systemic IL-23 deficiency. In comparison to IL-12, directly inducing differentiation of IFN-gamma–producing Th1, IL-23 cannot induce Th17 differentiation. None of the two cytokines affect proliferation, though, IL-23 activates T cell migratory potential and increases T cell migration by twofold. At the same time, deficiency of IL-23-production by bmDCs leads to lower migration of T cells. We also show an involvement of RhoA, and the other Rho GTPases, in the mechanism of migration as blocking revoke the IL-23 effect on T cells. Moreover, we further observed more fibrosis and worse heart functioning in IL-23−/−, but not IL-12−/− mice at the chronic stage what underlines the importance of IL-23-dependent T cell trafficking in the resolution of the acute stage of autoimmune myocarditis.

Conclusion

Our observations underline IL-23 as an important cytokine responsible for T cell trafficking and resolution of the inflammation in autoimmune myocarditis. Therapeutic approaches involving inflammatory cytokine targeting are a promising clinical perspective though IL-23 deficiency might lead to increased cardiac remodeling and iDCM progression.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Swiss National Science Foundation

Effects of Melagatran, a New Low-molecular-weight Thrombin Inhibitor, on Thrombin and Fibrinolytic Enzymes

Melagatran, a new, competitive and rapid inhibitor of thrombin with a molecular mass of 429 Da is described. Melagatran is well tolerated when administered in very high doses, and the oral bioavailability in the dog is relatively high. The aim of the study was to determine, in the preclinical setting, the degree of selectivity against the fibrinolytic system required for entering the clinical development phase. Melagatran was compared with two structurally similar thrombin inhibitors, inogatran and H 317/86. The potent inhibition of thrombin by melagatran was demonstrated by a low inhibition constant (Ki) for thrombin (0.002 μmol/l) and prolongation of clotting time to twice the control value in coagulation assays at low concentrations (0.010, 0.59 and 2.2 μmol/l for thrombin time, activated partial thromboplastin time and prothrombin time, respectively). Furthermore, thrombin-induced platelet aggregation was inhibited at the same concentration (IC50-value 0.002 μmol/l) as the Ki-value for thrombin. In two assays of global fibrinolysis, inhibition was observed at a concentration of 1.1 μmol/l in a euglobulin plasma fraction model, while no inhibition was observed at a concentration of ≤10 μmol/l in a plasma model. In an in vivo model of endogenous fibrinolysis in the rat, inhibition of fibrinolysis was observed at ≥1.0 μmol/l. In all assays, except the Ki-ratio determinations, the compounds could be graded with regard to selectivity against the fibrinolytic system: inogatran > melagatran > H 317/86. For melagatran, inhibition of fibrinolysis was not observed at concentrations below the upper limit of the proposed therapeutic plasma concentration interval (<0.5 μmol/l). Thus, melagatran seems to have a sufficient selectivity against the fibrinolytic system, while H 317/86 was considered to be insufficient for clinical development.

Contribution of precursor compounds to the release of per- and polyfluoroalkyl substances (PFASs) from waste water treatment plants (WWTPs)

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs, precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well. Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids (PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters (PAPs) were 15-20ng/g dry weight, the sum of fluorotelomer sulfonic acids (FTSAs) was 0.8-1.3ng/g, and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2ng/g. Persistent PFSAs and PFCAs were detected at 1.9-3.9ng/g and 2.4-7.3ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%, respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment.

Randomized assessment of imatinib in patients with acute ischaemic stroke treated with intravenous thrombolysis

BACKGROUND

Imatinib, a tyrosine kinase inhibitor, has been shown to restore blood-brain barrier integrity and reduce infarct size, haemorrhagic transformation and cerebral oedema in stroke models treated with tissue plasminogen activator. We evaluated the safety of imatinib, based on clinical and neuroradiological data, and its potential influence on neurological and functional outcomes.

METHODS

A phase II randomized trial was performed in patients with acute ischaemic stroke treated with intravenous thrombolysis. A total of 60 patients were randomly assigned to four groups [3 (active): 1 (control)]; the active treatment groups received oral imatinib for 6 days at three dose levels (400, 600 and 800 mg). Primary outcome was any adverse event; secondary outcomes were haemorrhagic transformation, cerebral oedema, neurological severity on the National Institutes of Health Stroke Scale (NIHSS) at 7 days and at 3 months and functional outcomes on the modified Rankin scale (mRS).

RESULTS

Four serious adverse events were reported, which resulted in three deaths (one in the control group and two in the 400-mg dose group; one patient in the latter group did not receive active treatment and the other received two doses). Nonserious adverse events were mostly mild, resulting in full recovery. Imatinib ameliorated neurological outcomes with an improvement of 0.6 NIHSS points per 100 mg imatinib (P = 0.02). For the 800-mg group, the mean unadjusted and adjusted NIHSS improvements were 4 (P = 0.037) and 5 points (P = 0.012), respectively, versus controls. Functional independence (mRS 0-2) increased by 18% versus controls (61 vs. 79; P = 0.296).

CONCLUSION

This phase II study showed that imatinib is safe and tolerable and may reduce neurological disability in patients treated with intravenous thrombolysis after ischaemic stroke. A confirmatory randomized trial is currently underway.

Temporal trends of PFSAs, PFCAs and selected precursors in Australian serum from 2002 to 2013

Per- and polyfluoroalkyl substances (PFASs) are a family of compounds that includes numerous compound classes. To date, only a subset of these PFASs have been studied thoroughly in the general population. In this study, pooled serum samples from Australia collected in 2002-2013 were analyzed for PFASs according to gender and age (age categories of 0-4 years, 5-15 years, 16-30 years, 31-45 years, 46-60 years, and >60 years), in total 54 pooled samples and 4920 individuals. Compound classes included were perfluorocarboxylic acids (PFCAs), perfluorosulfonic acids (PFSAs), and two groups of PFCA precursor compounds; polyfluoroalkyl phosphate diesters (diPAPs), and fluorotelomer sulfonic acids (FTSAs). Several PFASs that were not reported in previous studies of Australian serum samples were found in this sample set including; diPAPs, FTSAs, perfluoropentane sulfonic acid (PFPeS), perfluoroheptane sulfonic acid (PFHpS), perfluoroheptane carboxylic acid (PFHpA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorotridecanoic acid (PFTrDA). Various temporal trends were observed with a significant reduction (p < 0.05) between 2002 and 2013 for 8:2 FTSA, perflurohexane sulfonic acid (PFHxS), PFHpS, PFOS, and perflurooctanoic acid (PFOA). Levels of longer-chained PFDA and PFUnDA started to decrease more recently, between 2006 and 2013, while PFDoDA increased during the same time period. Higher levels in younger age groups (0-4 and 5-15 years) compared to adults (>15 years) were found for 8:2 FTSA and PFHpA, while levels of PFHpS, PFOS, PFUnDA, PFDoDA and PFTrDA were higher in adult age groups compared to younger age groups. Gender-specific patterns were seen for PFOA, PFHxS, PFHpS and PFOS, where levels were lower in women. Changes in manufacturing processes were reflected in the temporal time trends, and differences in bioaccumulation potential between homologues could be associated with age trends. Our results emphasize the importance of including emerging classes of PFASs in biomonitoring studies.

Soluble Vascular Cell Adhesion Molecule-1 (VCAM-1) as a Biomarker in the Mouse Model of Experimental Autoimmune Myocarditis (EAM)

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

Production and turnover of ectomycorrhizal extramatrical mycelial biomass and necromass under elevated CO2 and nitrogen fertilization

Extramatrical mycelia (EMM) of ectomycorrhizal fungi are important in carbon (C) and nitrogen (N) cycling in forests, but poor knowledge about EMM biomass and necromass turnovers makes the quantification of their role problematic. We studied the impacts of elevated CO2 and N fertilization on EMM production and turnover in a Pinus taeda forest. EMM C was determined by the analysis of ergosterol (biomass), chitin (total bio- and necromass) and total organic C (TOC) of sand-filled mycelium in-growth bags. The production and turnover of EMM bio- and necromass and total C were estimated by modelling. N fertilization reduced the standing EMM biomass C to 57% and its production to 51% of the control (from 238 to 122 kg C ha(-1)  yr(-1) ), whereas elevated CO2 had no detectable effects. Biomass turnover was high (˜13 yr(-1) ) and unchanged by the treatments. Necromass turnover was slow and was reduced from 1.5 yr(-1) in the control to 0.65 yr(-1) in the N-fertilized treatment. However, TOC data did not support an N effect on necromass turnover. An estimated EMM production ranging from 2.5 to 6% of net primary production stresses the importance of its inclusion in C models. A slow EMM necromass turnover indicates an importance in building up forest humus.

Comparison of PFASs contamination in the freshwater and terrestrial environments by analysis of eggs from osprey (Pandion haliaetus), tawny owl (Strix aluco), and common kestrel (Falco tinnunculus)

The level of PFAS (per- and polyfluorinated alkyl substances) contamination in freshwater and terrestrial Swedish environments in 2013/2014 was assessed by analyzing a range of perfluorinated alkyl acids, fluorotelomer acids, sulfonamides, sulfonamidoethanols and polyfluoralkyl phosphate diesters (diPAPs) in predator bird eggs. Stable isotopes ((13)C and (15)N) were analyzed to elucidate the dietary source. The tawny owl (Strix aluco, n=10) and common kestrel (Falco tinnunculus, n=40), two terrestrial species, and the osprey (Pandion haliaetus, n=30), a freshwater specie were included. In addition, a temporal trend (1997-2001, 2008-2009, 2013) in osprey was studied as well. The PFAS profile was dominated by perfluorooctane sulfonic acid (PFOS) in eggs from osprey and tawny owl, while for common kestrel perfluorinated carboxylic acids (∑PFCA) exceeded the level of PFOS. PFOS concentration in osprey eggs remained at the same level between 1997 and 2001 and 2013. For the long-chained PFCAs, there were a significant increase in concentrations in osprey eggs between 1997 and 2001 and 2008-2009. The levels of PFOS and PFCAs were about 10 and five times higher, respectively, in osprey compared to tawny owl and common kestrel. Evidence of direct exposure from PFCA precursor compounds to birds in both freshwater and terrestrial environment was observed. Low levels of diPAPs were detected in a few samples of osprey (<0.02-2.4ng/g) and common kestrel (<0.02-0.16ng/g) eggs, and 6:2 FTSA was detected in a majority of the osprey eggs (<6.3-52ng/g). One saturated telomer acid (7:3 FTCA), which is a transformation marker from precursor exposure, was detected in all species (<0.24-2.7ng/g). The (15)N data showed higher levels in osprey eggs compared to tawny owl and common kestrel, indicating that they feed on a 2-3 times higher trophic level. We conclude that ospreys are continuously exposed to PFAS at levels where adverse toxic effects have been observed in birds.

Discovery of AZD8165 – a clinical candidate from a novel series of neutral thrombin inhibitors

A novel series of neutral thrombin inhibitors has been developed using a selection process based on docking experiments and property calculations and predictions.

World-Wide Indoor Exposure to Polyfluoroalkyl Phosphate Esters (PAPs) and other PFASs in Household Dust

Human exposure to perfluorooctanoic acid (PFOA) and other per- and polyfluoroalkyl substances (PFASs) is ongoing and in some cases increasing, despite efforts made to reduce emissions. The role of precursor compounds such as polyfluorinated phosphate esters (PAPs) has received increasing attention, but there are knowledge gaps regarding their occurrence and impact on human exposure. In this study, mono-, di-, and triPAPs, perfluorinated alkyl acids (PFAAs), saturated, and unsaturated fluorotelomer carboxylic acids (FTCA/FTUCAs), perfluoroalkane sulfonamides, and sulfonamidethanols (FOSA/FOSEs), and one fluorotelomer sulfonic acid (FTSA)) were compared in household dust samples from Canada, the Faroe Islands, Sweden, Greece, Spain, Nepal, Japan, and Australia. Mono-, di-, and triPAPs, including several diPAP homologues, were frequently detected in dust from all countries, revealing an ubiquitous spread in private households from diverse geographic areas, with significant differences between countries. The median levels of monoPAPs and diPAPs ranged from 3.7 ng/g to 1 023 ng/g and 3.6 ng/g to 692 ng/g, respectively, with the lowest levels found in Nepal and the highest in Japan. The levels of PAPs exceeded those of the other PFAS classes. These findings reveal the importance of PAPs as a source of PFAS exposure worldwide.

Reflections of older people living in nursing homes

AIM

To explore experiences of ageing in older people living in nursing homes, based on the gerotranscendence theory.

METHOD

Interviews were held with 14 people aged between 80 and 96 years. The results were analysed using content analysis.

FINDINGS

The findings were divided into three categories: the self, the cosmic dimension, and social and personal relationships. These three categories were underpinned by eight subcategories. Most participants described improved knowledge about themselves, decreased concern about body and appearance, acceptance and appreciation of life, and less regard for social norms. A fewer participants described a greater affinity with past generations, or thought that the borders between past and present had become blurred.

CONCLUSION

This study provides a better understanding of how people experience old age. It also indicates how healthcare professionals could apply the gerotranscendence theory of ageing as a conversation model to enable care to be adjusted according to older people's wishes.

Perfluoroalkyl substances (PFASs) in food and water from Faroe Islands

Diet and drinking water are suggested to be major exposure pathways for perfluoroalkyl substances (PFASs). In this study, food items and water from Faroe Islands sampled in 2011/2012 were analyzed for 11 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonic acids (PFSAs). The food samples included milk, yoghurt, crème fraiche, potatoes, fish, and fish feed, and the water samples included surface water and purified drinking water. In total, nine PFCAs and four PFSAs were detected. Generally, the levels of PFAS were in the lower picogram per gram range. Perfluorobutanoic acid was a major contributor to the total PFASs concentration in water samples and had a mean concentration of 750 pg/L. Perfluoroundecanoic acid (PFUnDA) was predominating in milk and wild fish with mean concentrations of 170 pg/g. Perfluorooctane sulfonic acid (PFOS) was most frequently detected in food items followed by PFUnDA, perfluorononanoic acid, and perfluorooctanoic acid (PFOA). Levels of PFUnDA and PFOA exceeded those of PFOS in milk and fish samples. Prevalence of long-chain PFCAs in Faroese food items and water is confirming earlier observations of their increase in Arctic biota. Predominance of short-chain and long-chain homologues indicates exposure from PFOS and PFOA replacement compounds.

Shared physical custody after family split-up: implications for health and well-being in Swedish schoolchildren

AIM

In Sweden, shared physical custody following a parental separation has emerged as means for children to keep close relationships with both parents. Previous studies show that children benefit from regular contact with both parents, who share responsibility for their social, emotional and economic welfare. In this study, we investigate any associations between family arrangements, that is, two-parent, single and shared physical custody families and child health outcomes and whether this association was modified by parent-child communication.

METHODS

Data on 11- to 15-year-old children from the 2005/2006 and 2009/2010 Swedish Health Behaviour in School-aged Children survey were analysed using multivariate logistic regression.

RESULTS

Children in shared physical custody were more likely than children in two-parent families to report multiple health complaints (OR 1.26) and low well-being (OR 1.71). When variables of parent-child communication were entered in the model, the initial differences remained between children living in shared physical custody and those living in two-parent families.

CONCLUSION

Children in shared physical custody and single-parent families are more at risk of negative outcomes compared with children in two-parent families. This association was not modified by parent-child communication in children in shared custody families, indicating that the communication equals that in two-parent family children.

Human dietary exposure to perfluoroalkyl substances in Catalonia, Spain. Temporal trend

In this study, we assessed the levels of 18 perfluoroalkyl substances (PFASs) in the most widely consumed foodstuffs in Catalonia, Spain, as well as the total dietary intake of these compounds. Forty food items were analysed. Only perfluoropentanoic acid (PFPeA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctanoicdecanoic acid (PFOcDA) were not detected in any sample. Perfluorooctane sulfonate (PFOS) was the compound found in the highest number of samples (33 out of 80), followed by perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA) and perfluorodecane sulfonic acid (PFDS). Fish and shellfish was the food group in which more PFASs were detected and where the highest PFAS concentrations were found. The highest dietary intakes corresponded to children, followed by male seniors, with values of 1787 and 1466ng/day, respectively. For any of the age/gender groups of the population, the Tolerable Daily Intakes (TDIs) recommended by the EFSA were not exceeded. In general terms, PFAS levels found in the current study are lower than the concentrations recently reported in other countries.

Health outcomes among Swedish children: the role of social capital in the family, school and neighbourhood

AIM

The aim of the study was to explore the extent to which Swedish children's perceptions of social capital in the family, school and neighbourhood predicted health complaints and well-being.

METHODS

The study used data from the Swedish Health Behaviour in School-aged Children survey. The sample consisted of 3926 children aged 11-15 years. Correlations and hierarchical multiple linear regression were performed.

RESULTS

Higher degrees of family, school and neighbourhood social capital corresponded to lower levels of health complaints and higher levels of well-being. Social capital in these three spheres had a cumulative effect on children's health and well-being.

CONCLUSIONS

Social capital in the family, school and neighbourhood matters for children's health and well-being and the contributions from each context seem to be additive. Besides the family context, investments for improving child health should primarily be in the school, focusing on social relations and on creating safe and cohesive school environments. Neighbourhood social capital is also of importance and so must be taken into consideration when planning child health promotion interventions.

Perceptions of community trust and safety - consequences for children's well-being in rural and urban contexts

AIM

To explore the associations between subjective well-being and perceptions of community trust and safety amongst children in rural and urban areas.

METHODS

The study used self-reported data from the 2001/2002 Swedish cross-national WHO study Health Behaviour in School-aged Children. The sample consisted of 3852 children aged 11-15 years, living in different residential areas. Bivariate analyses and multivariate logistic regression were performed.

RESULTS

The results indicated that a greater proportion of children in urban areas perceived low community trust and safety, compared with children in rural areas. Further, the multivariate analysis revealed that perceived community trust and safety significantly impacts upon children's subjective well-being in both rural and urban contexts.

CONCLUSION

Children's perceptions of trust and safety have different magnitudes in urban and rural areas. The associations of perceptions of community trust and safety for children's subjective well-being are relevant in both urban and rural areas. As perceptions of low trust and safety in the community seem to be related to low subjective well-being, efforts to encourage community trust and safety should be included amongst the key priorities in community health promotion.

Growing up in rural community--children's experiences of social capital from perspectives of wellbeing

INTRODUCTION

People are influenced by the neighborhood in which they live. The neighborhood may be particularly important for children's wellbeing because of the constraints it imposes on their patterns of daily activities. Furthermore, the neighborhood is a central context for social development, being a place where children form networks and learn social skills and values. The aim of this study was to describe how social capital in the neighborhood is perceived by children living in rural areas, and to reveal what this adds to their sense of wellbeing.

METHODS

The study had a descriptive research design with a qualitative approach. Seven single-sex focus group interviews were conducted with children the in 6th grade (aged 11-12 years). Data were analyzed using deductive content analysis.

RESULTS

The children perceived a lack of social capital due to environmental and social constraints in their everyday lives. However, their wellbeing was enhanced by strong cohesion in the neighborhood. In addition, settings such as the school, the natural environment, and sporting associations were highly valued and emerged as crucial factors for enhancing the children's wellbeing. The spatial isolation that characterizes rural areas created a special context of social network structures, cohesion and trust, but was also a breeding ground for exclusion and social control. The stories revealed paradoxical feelings of living in a good and safe area that simultaneously felt isolated and restricted.

CONCLUSIONS

From a rural perspective, this study reveals the complexity of the children's perceptions of their social environment, and the ways in which these perceptions have both positive and negative effects on wellbeing. The results highlight how important it is for health professionals in rural areas to consider the complex influence of bonding social capital on children's wellbeing, and to be aware that it can promote exclusion as well as cohesion.

School demands and subjective health complaints among Swedish schoolchildren: a multilevel study

OBJECTIVES

As children spend a great deal of their time in school, the climate in the classroom can constitute a resource, but also a risk factor in the development of the pupils' health. The aim of the present study was to determine the extent to which demands in the classroom are associated with subjective health complaints in Swedish schoolchildren.

METHODS

Data from the 2001/2002 and 2005/2006 Swedish cross-national Health Behaviour in School-aged Children (HBSC) survey were analysed using a multilevel logistic regression technique.

RESULTS

The study demonstrated a substantial variation between school classes in pupils' subjective health complaints. In school classes with high demands, the odds of having subjective health complaints was about 50% higher than in school classes with low demands. Further, the results indicated that these effects were mediated by sex so as to girls being more affected by high levels of demands in the school class.

CONCLUSIONS

The findings are important since they point at the crucial role that teachers play in creating a favourable school climate. Therefore interventions aiming at supporting teachers to set realistic demands and expectations are one way to improve the school climate. Such interventions should also make clear the need to take into consideration the fact that the school class effect was mediated by sex, i.e. girls being more vulnerable to high level of school class demands.

Tissue plasminogen activator-mediated PDGF signaling and neurovascular coupling in stroke

The use of tissue plasminogen activator (tPA) as a thrombolytic treatment in ischemic stroke is limited largely due to concerns for hemorrhagic complications. The underlying mechanisms are still unknown, but evidence is beginning to emerge that tPA interacts with key regulators of the neurovascular unit (NVU), and that these interactions may contribute to the undesirable side effects associated with the use of tPA in ischemic stroke. Understanding these connections and tPA's normal function within the NVU may offer new insights into future therapeutic approaches.

PDGF-C and -D and their receptors PDGFR-alpha and PDGFR-beta in atherosclerotic human arteries

BACKGROUND

Platelet derived growth factors (PDGFs) are mitogens for fibroblasts and smooth muscle cells. This growth factor family contains four members PDGF-A, PDGF-B, PDGF-C and PDGF-D. Biology of recently discovered PDGF-C and PDGF-D is not well-established. Here we studied the expression of PDGF-C and PDGF-D and their receptors PDGFR-alpha and PDGFR-beta in normal and atherosclerotic human arteries.

MATERIALS AND METHODS

Human arterial samples from amputations and autopsies were classified according to the atherosclerotic stage and the expression of PDGF-C and PDGF-D proteins and their receptors was studied by immunohistochemistry. In situ hybridization and reverse transcriptase-PCR were used to study mRNA expression.

RESULTS

Both growth factors were expressed in medial smooth muscle cells (SMCs) in normal arteries and atherosclerotic lesions. However, clear differences were found in the expression profiles in endothelium: PDGF-C was strongly expressed in endothelial cells in both normal arteries and lesions whereas PDGF-D was only weakly expressed in endothelium. PDGF-C expression was very prominent in lesion macrophages. PDGF-D was expressed throughout the artery wall in lesions. PDGFR-alpha expression was strong in endothelium and in lesion macrophage-rich areas, whereas PDGFR-beta was mostly expressed in SMCs.

CONCLUSIONS

Our results suggest that PDGF-C may play an important role in endothelium in normal and atherosclerotic arteries and in macrophages in lesions. PDGF-D was expressed in all types of lesions with the same intensity and thus differs from the expression of PDGF-C.

Serine peptide phosphoester prodrugs of cyclic cidofovir: synthesis, transport, and antiviral activity

Cidofovir (HPMPC, 1), a broad-spectrum antiviral agent, is currently used to treat AIDS-related human cytomegalovirus (HCMV) retinitis and has recognized therapeutic potential for orthopox virus infections, but is limited by its low oral bioavailability. Cyclic cidofovir (2) displays decreased nephrotoxicity compared to 1, while also exhibiting potent antiviral activity. Here we describe in detail the synthesis and evaluation as prodrugs of four cHPMPC dipeptide conjugates in which the free POH of 2 is esterified by the Ser side chain alcohol group of an X-L-Ser(OMe) dipeptide: 3 (X=L-Ala), 4 (X=L-Val), 5 (X=L-Leu), and 6 (X=L-Phe). Perfusion studies in the rat establish that the mesenteric permeability to 4 is more than 20-fold greater than to 1, and the bioavailability of 4 is increased 6-fold relative to 1 in an in vivo murine model. In gastrointestinal and liver homogenates, the cHPMPC prodrugs are rapidly hydrolyzed to 2. Prodrugs 3, 4, and 5 are nontoxic at 100 microM in HFF and KB cells and in cell-based plaque reduction assays had IC 50 values of 0.1-0.5 microM for HCMV and 10 microM for two orthopox viruses (vaccinia and cowpox). The enhanced transport properties of 3-6, conferred by incorporation of a biologically benign dipeptide moiety, and the facile cleavage of the Ser-O-P linkage suggest that these prodrugs represent a promising new approach to enhancing the bioavailability of 2.