78 research outputs found

    Mirror image serum lipid carrier protein profiles in pup and lactating mother Atlantic grey seals reflect contrasting resource mobilisation challenges

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    Funding: The work was funded from core support given to the Sea Mammal Research Unit, Scottish Oceans Institute, from the Natural Environmental Research Council (United Kingdom).True, phocid seals have the shortest known lactations relative to body mass, during which mass transfer of adipose stores from mother to offspring occurs at an unrivalled rate and extent. The mothers of most species of seal fast until weaning whilst their pups gorge on the most fat-rich milks known. This results in a dramatic reduction in maternal blubber mass while pups may triple their body weights before weaning. Mothers mobilise their blubber fat, transport it via blood to their mammary glands and into milk, whilst pups transfer fat in the opposite direction, from their intestines, via blood, to their blubber. Using proteomic analysis of mother and pup sera from Atlantic grey seals, we find that this mirror image flux of lipids between mothers and pups is reflected in an almost inverse relationship in the proteins in their blood specialised to transport fats, lipids, and fat-soluble vitamins. For instance, apolipoproteins ApoB-48/100, ApoA-II and ApoA-IV, which are structural components of the main lipid carrier complexes such as chylomicrons and HDL particles, occur at much higher levels in pups than mothers. Meanwhile, carriers of fat-soluble vitamins such as retinol- and vitamin D-binding proteins are lower in pups and gradually build towards weaning. In contrast, sex hormone-binding globulin occurs at remarkably high relative concentrations in pups. There are therefore dramatic differences between, and an unrealised complexity in, the balance of proteins involved in the rapid transfer of fats and other lipids from mother to pups in preparing their offspring for their post-weaning fasts on land and eventual survival at sea before they can feed again.Publisher PDFPeer reviewe

    Uncomplicated Plasmodium vivax malaria: mapping the proteome from circulating platelets

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    Background: Thrombocytopenia is frequent in Plasmodium vivax malaria but the role of platelets in pathogenesis is unknown. Our study explores the platelet (PLT) proteome from uncomplicated P. vivax patients, to fingerprint molecular pathways related to platelet function. Plasma levels of Platelet factor 4 (PF4/CXCL4) and Von Willebrand factor (VWf), as well as in vitro PLTs—P. vivax infected erythrocytes (Pv-IEs) interactions were also evaluated to explore the PLT response and effect on parasite development. Methods: A cohort of 48 patients and 25 healthy controls were enrolled. PLTs were purified from 5 patients and 5 healthy controls for Liquid Chromatography–Mass spectrometry (LC–MS/MS) analysis. Plasma levels of PF4/CXCL4 and VWf were measured in all participants. Additionally, P. vivax isolates (n = 10) were co-cultured with PLTs to measure PLT activation by PF4/CXCL4 and Pv-IE schizonts formation by light microscopy. Results: The proteome from uncomplicated P. vivax patients showed 26 out of 215 proteins significantly decreased. PF4/CXCL4 was significantly decreased followed by other proteins involved in platelet activation, cytoskeletal remodeling, and endothelial adhesion, including glycoprotein V that was significantly decreased in thrombocytopenic patients. In contrast, acute phase proteins, including SERPINs and Amyloid Serum A1 were increased. High levels of VWf in plasma from patients suggested endothelial activation while PF4/CXCL4 plasma levels were similar between patients and controls. Interestingly, high levels of PF4/CXCL4 were released from PLTs—Pv-IEs co-cultures while Pv-IEs schizont formation was inhibited. Conclusions: The PLT proteome analyzed in this study suggests that PLTs actively respond to P. vivax infection. Altogether, our findings suggest important roles of PF4/CXCL4 during uncomplicated P. vivax infection through a possible intracellular localization. Our study shows that platelets are active responders to P. vivax infection, inhibiting intraerythrocytic parasite development. Future studies are needed to further investigate the molecular pathways of interaction between platelet proteins found in this study and host response, which could affect parasite control as well as disease progression

    Rapid changes in Atlantic grey seal milk from birth to weaning – immune factors and indicators of metabolic strain

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    True seals have the shortest lactation periods of any group of placental mammal. Most are capital breeders that undergo short, intense lactations, during which they fast while transferring substantial proportions of their body reserves to their pups, which they then abruptly wean. Milk was collected from Atlantic grey seals (Halichoerus grypus) periodically from birth until near weaning. Milk protein profiles matured within 24 hours or less, indicating the most rapid transition from colostrum to mature phase lactation yet observed. There was an unexpected persistence of immunoglobulin G almost until weaning, potentially indicating prolonged trans-intestinal transfer of IgG. Among components of innate immune protection were found fucosyllactose and siallylactose that are thought to impede colonisation by pathogens and encourage an appropriate milk-digestive and protective gut microbiome. These oligosaccharides decreased from early lactation to almost undetectable levels by weaning. Taurine levels were initially high, then fell, possibly indicative of taurine dependency in seals, and progressive depletion of maternal reserves. Metabolites that signal changes in the mother’s metabolism of fats, such as nicotinamide and derivatives, rose from virtual absence, and acetylcarnitines fell. It is therefore possible that indicators of maternal metabolic strain exist that signal the imminence of weaning.Publisher PDFPeer reviewe

    Is a little enough? Paucity of immune proteins in serum of precocial neonates of a marine carnivoran—the Atlantic grey seal

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    Mammalian mothers usually provide their offspring with large quantities of immunoglobulins (antibodies) for circulation in blood, either trans-placentally before birth, via colostrum briefly thereafter, or, less commonly, from milk. Neonates of true, phocid seals, however, are peculiarly impoverished in serum immunoglobulins, the levels of which slowly increase but do not reach adult levels by the time of weaning. We investigated whether grey seal (Halichoerus grypus) neonates compensate through an elevation or rapid maturation in levels of serum innate immune factors, namely acute phase and complement proteins. Instead, their sera contained remarkably low levels of acute phase proteins (including C-reactive protein, haptoglobin, hemopexin, ceruloplasmin, orosomucoid), compared to their mothers, that barely increased to adult levels by weaning. For complement, there was a strong demarcation between the early activation and amplification cascade components (present at normal adult levels in pups) and the late lytic membrane attack complex and regulatory proteins (consistently at low relative levels). Phocid neonates therefore differ dramatically from land Carnivorans, such as dogs and cats, in early life immune protection. That neonatal phocids survive this apparent vulnerability to infections between birth and weaning prompts questions as to what other mechanisms protect them, and the adaptive value of their seeming vulnerability

    Limited Impact of the Protein Corona on the Cellular Uptake of PEGylated Zein Micelles by Melanoma Cancer Cells

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    The formation of a protein layer corona on the nanoparticle surface upon entry into a biological environment was shown to strongly influence the interactions with cells, especially affecting the uptake of nanomedicines. In this work, we present the impact of the protein corona on the uptake of PEGylated zein micelles by cancer cells, macrophages, and dendritic cells. Zein was successfully conjugated with poly(ethylene glycol) (PEG) of varying chain lengths (5K and 10K) and assembled into micelles. Our results demonstrate that PEGylation conferred stealth effects to the zein micelles. The presence of human plasma did not impact the uptake levels of the micelles by melanoma cancer cells, regardless of the PEG chain length used. In contrast, it decreased the uptake by macrophages and dendritic cells. These results therefore make PEGylated zein micelles promising as potential drug delivery systems for cancer therapy

    Interventions to support the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic: a mixed methods systematic review

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    Background Evidence from disease epidemics shows that healthcare workers are at risk of developing short‐ and long‐term mental health problems. The World Health Organization (WHO) has warned about the potential negative impact of the COVID‐19 crisis on the mental well‐being of health and social care professionals. Symptoms of mental health problems commonly include depression, anxiety, stress, and additional cognitive and social problems; these can impact on function in the workplace. The mental health and resilience (ability to cope with the negative effects of stress) of frontline health and social care professionals ('frontline workers' in this review) could be supported during disease epidemics by workplace interventions, interventions to support basic daily needs, psychological support interventions, pharmacological interventions, or a combination of any or all of these. Objectives Objective 1: to assess the effects of interventions aimed at supporting the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic. Objective 2: to identify barriers and facilitators that may impact on the implementation of interventions aimed at supporting the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic. Search methods On 28 May 2020 we searched the Cochrane Database of Systematic Reviews, CENTRAL, MEDLINE, Embase, Web of Science, PsycINFO, CINAHL, Global Index Medicus databases and WHO Institutional Repository for Information Sharing. We also searched ongoing trials registers and Google Scholar. We ran all searches from the year 2002 onwards, with no language restrictions. Selection criteria We included studies in which participants were health and social care professionals working at the front line during infectious disease outbreaks, categorised as epidemics or pandemics by WHO, from 2002 onwards. For objective 1 we included quantitative evidence from randomised trials, non‐randomised trials, controlled before‐after studies and interrupted time series studies, which investigated the effect of any intervention to support mental health or resilience, compared to no intervention, standard care, placebo or attention control intervention, or other active interventions. For objective 2 we included qualitative evidence from studies that described barriers and facilitators to the implementation of interventions. Outcomes critical to this review were general mental health and resilience. Additional outcomes included psychological symptoms of anxiety, depression or stress; burnout; other mental health disorders; workplace staffing; and adverse events arising from interventions. Data collection and analysis Pairs of review authors independently applied selection criteria to abstracts and full papers, with disagreements resolved through discussion. One review author systematically extracted data, cross‐checked by a second review author. For objective 1, we assessed risk of bias of studies of effectiveness using the Cochrane 'Risk of bias' tool. For objective 2, we assessed methodological limitations using either the CASP (Critical Appraisal Skills Programme) qualitative study tool, for qualitative studies, or WEIRD (Ways of Evaluating Important and Relevant Data) tool, for descriptive studies. We planned meta‐analyses of pairwise comparisons for outcomes if direct evidence were available. Two review authors extracted evidence relating to barriers and facilitators to implementation, organised these around the domains of the Consolidated Framework of Implementation Research, and used the GRADE‐CERQual approach to assess confidence in each finding. We planned to produce an overarching synthesis, bringing quantitative and qualitative findings together. Main results We included 16 studies that reported implementation of an intervention aimed at supporting the resilience or mental health of frontline workers during disease outbreaks (severe acute respiratory syndrome (SARS): 2; Ebola: 9; Middle East respiratory syndrome (MERS): 1; COVID‐19: 4). Interventions studied included workplace interventions, such as training, structure and communication (6 studies); psychological support interventions, such as counselling and psychology services (8 studies); and multifaceted interventions (2 studies). Objective 1: a mixed‐methods study that incorporated a cluster‐randomised trial, investigating the effect of a work‐based intervention, provided very low‐certainty evidence about the effect of training frontline healthcare workers to deliver psychological first aid on a measure of burnout. Objective 2: we included all 16 studies in our qualitative evidence synthesis; we classified seven as qualitative and nine as descriptive studies. We identified 17 key findings from multiple barriers and facilitators reported in studies. We did not have high confidence in any of the findings; we had moderate confidence in six findings and low to very low confidence in 11 findings. We are moderately confident that the following two factors were barriers to intervention implementation: frontline workers, or the organisations in which they worked, not being fully aware of what they needed to support their mental well‐being; and a lack of equipment, staff time or skills needed for an intervention. We are moderately confident that the following three factors were facilitators of intervention implementation: interventions that could be adapted for local needs; having effective communication, both formally and socially; and having positive, safe and supportive learning environments for frontline workers. We are moderately confident that the knowledge or beliefs, or both, that people have about an intervention can act as either barriers or facilitators to implementation of the intervention. Authors' conclusions There is a lack of both quantitative and qualitative evidence from studies carried out during or after disease epidemics and pandemics that can inform the selection of interventions that are beneficial to the resilience and mental health of frontline workers. Alternative sources of evidence (e.g. from other healthcare crises, and general evidence about interventions that support mental well‐being) could therefore be used to inform decision making. When selecting interventions aimed at supporting frontline workers' mental health, organisational, social, personal, and psychological factors may all be important. Research to determine the effectiveness of interventions is a high priority. The COVID‐19 pandemic provides unique opportunities for robust evaluation of interventions. Future studies must be developed with appropriately rigorous planning, including development, peer review and transparent reporting of research protocols, following guidance and standards for best practice, and with appropriate length of follow‐up. Factors that may act as barriers and facilitators to implementation of interventions should be considered during the planning of future research and when selecting interventions to deliver within local settings

    Mitochondrial Phenotypes in Purified Human Immune Cell Subtypes and Cell Mixtures

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    Using a high-throughput mitochondrial phenotyping platform to quantify multiple mitochondrial features among molecularly defined immune cell subtypes, we quantify the natural variation in mitochondrial DNA copy number (mtDNAcn), citrate synthase, and respiratory chain enzymatic activities in human neutrophils, monocytes, B cells, and naĂŻve and memory T lymphocyte subtypes. In mixed peripheral blood mononuclear cells (PBMCs) from the same individuals, we show to what extent mitochondrial measures are confounded by both cell type distributions and contaminating platelets. Cell subtype-specific measures among women and men spanning four decades of life indicate potential age- and sex-related differences, including an age-related elevation in mtDNAcn, which are masked or blunted in mixed PBMCs. Finally, a proof-of-concept, repeated-measures study in a single individual validates cell type differences and also reveals week-to-week changes in mitochondrial activities. Larger studies are required to validate and mechanistically extend these findings. These mitochondrial phenotyping data build upon established immunometabolic differences among leukocyte subpopulations, and provide foundational quantitative knowledge to develop interpretable blood-based assays of mitochondrial health

    Consumers\u27 Misunderstanding of Health Insurance.

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    We report results from two surveys of representative samples of Americans with private health insurance. The first examines how well Americans understand, and believe they understand, traditional health insurance coverage. The second examines whether those insured under a simplified all-copay insurance plan will be more likely to engage in cost-reducing behaviors relative to those insured under a traditional plan with deductibles and coinsurance, and measures consumer preferences between the two plans. The surveys provide strong evidence that consumers do not understand traditional plans and would better understand a simplified plan, but weaker evidence that a simplified plan would have strong appeal to consumers or change their healthcare choices
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