6,064 research outputs found

    Regulation of macrophage and granulocyte proliferation. Specificities of prostaglandin E and lactoferrin

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    Hemopoietic colony-forming cells committed to macrophage differentiation (M-CFC) are selectively and differentially inhibited by prostaglandin E (PGE). A hierarchy of sensitivity was observed among murine CFC stimulated by colony-stimulating factors (CSF) which differ in their ability to initiate proliferation of morphologically distinct colony types, or stimulated by CSF provided by macrophage feeder layers. Inhibition of macrophage colony formation to 50 percent levels occurred with PGE concentrations between 10(-8) and 10(-9) M, and was still evident at 10(-10) -10(-11) M PGE concentrations. The growth of mixed colonies containing both macrophages and neutrophils was less sensitive to the inhibitory effects of PGE, however, the monocytoid component of these colonies was reduced in the presence of PGE. Neutrophil progenitor cell proliferation was not influenced by PGE concentrations below 10(-6) M, regardless of time of addition of PGE, whereas clonal macrophage expansion, as well as clone size, was sensitive to inhibition by PGE when added as late as 3 d after culture initiation. Prostaglandin F(2α), was not inhibitory to colony formation. Experimental evidence for a selective role of macrophage PGE in the regulation of macrophage colony formation was directly provided by utilizing resident peritoneal macrophages as a source of CSF for bone marrow target cell overlays. Simultaneous morphological analysis of colonies proliferating in bilayer culture in response to increasing concentrations of macrophages, and direct measurements of PGE synthesized by an identical number of macrophages maintained in liquid culture demonstrate that a specific decline in macrophage colony formation occurs coincident with a linear increase in macrophage PGE synthesis. Inhibition of macrophage PGE synthesis by indomethacin results in the specific enhancement of macrophage colony formation. Furthermore, macrophage PGE synthesis is induced by CSF preparations with the selective capacity to differentially stimulate macrophage proliferation, but not by those which preferentially stimulate granulocyte colony formation. In comparison to the effects of PGE on M-CFC, polymorphonuclear granulocyte-derived lactoferrin (LF) reduces macrophage production of colony-stimulating activities for macrophage, mixed macrophage- neutrophil and neutrophil colony formation. The ability of LF to reduce macrophage PGE synthesis, presumably by decreasing CSF production, suggests that LF and PGE can interact in the control of macrophage and granulocyte proliferation

    Factors Influencing Pregnancy and Postpartum Weight Management in Women of African and Caribbean Ancestry Living in High Income Countries: Systematic Review and Evidence Synthesis Using a Behavioral Change Theoretical Model

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    Background: Women of black African heritage living in high income countries (HIC) are at risk of obesity and weight-related complications in pregnancy. This review aimed to synthesize evidence concerning attitudes to weight management-related health behaviors in pregnancy and postpartum, in women of black African ancestry, living in high-income countries. / Methods: A systematic review of the literature and thematic evidence synthesis using the Capability-Opportunity-Motivation Behavioral change theoretical model (COM-B). Databases searched included MEDLINE, EMBASE, Web of Science, and Scopus. The CASP tool was used to assess quality. / Results: Twenty-four papers met the selection criteria, most of which were from the US. Motivational factors were most commonly described as influencers on behavior. Normative beliefs about “eating for two,” weight gain being good for the baby, the baby itself driving food choice, as well as safety concerns about exercising in pregnancy, were evident and were perpetuated by significant others. These and other social norms, including a cultural acceptance of larger body shapes, and daily fast food, created a challenge for healthy behavior change. Women also had low confidence in their ability to lose weight in the postpartum period. Behavior change techniques, such as provision of social support, use of credible sources, and demonstration may be useful to support change. / Conclusions: The women face a range of barriers to engagement in weight-related health behaviors at this life-stage. Using a theoretical behavior change framework can help identify contextual factors that may limit or support behavior change

    Nutrition Strategies for Triathlon

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    Contemporary sports nutrition guidelines recommend that each athlete develop a personalised, periodised and practical approach to eating that allows him or her to train hard, recover and adapt optimally, stay free of illness and injury and compete at their best at peak races. Competitive triathletes undertake a heavy training programme to prepare for three different sports while undertaking races varying in duration from 20 min to 10 h. The everyday diet should be adequate in energy availability, provide CHO in varying amounts and timing around workouts according to the benefits of training with low or high CHO availability and spread high-quality protein over the day to maximise the adaptive response to each session. Race nutrition requires a targeted and well-practised plan that maintains fuel and hydration goals over the duration of the specific event, according to the opportunities provided by the race and other challenges, such as a hot environment. Supplements and sports foods can make a small contribution to a sports nutrition plan, when medical supplements are used under supervision to prevent/treat nutrient deficiencies (e.g. iron or vitamin D) or when sports foods provide a convenient source of nutrients when it is impractical to eat whole foods. Finally, a few evidence-based performance supplements may contribute to optimal race performance when used according to best practice protocols to suit the triathlete’s goals and individual responsiveness

    Compact High-Velocity Clouds at High Resolution

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    Six examples of the compact, isolated high-velocity clouds catalogued by Braun & Burton (1999) and identified with a dynamically cold ensemble of primitive objects falling towards the barycenter of the Local Group have been imaged with the Westerbork Synthesis Radio Telescope; an additional ten have been imaged with the Arecibo telescope. The imaging reveals a characteristic core/halo morphology: one or several cores of cool, relatively high-column-density material, are embedded in an extended halo of warmer, lower-density material. Several of the cores show kinematic gradients consistent with rotation; these CHVCs are evidently rotationally supported and dark-matter dominated. The imaging data allows several independent estimates of the distances to these objects, which lie in the range 0.3 to 1.0 Mpc. The CHVC properties resemble what might be expected from very dark dwarf irregular galaxies.Comment: 12 pages, 7 figures, to appear in "The Chemical Evolution of the Milky Way: Stars versus Clusters", eds. F. Matteuchi and F. Giovannelli, Kluwer Academic Publisher

    Investigation of SLA4A3 as a candidate gene for human retinal disease.

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    SLC4A3 has been shown to cause retinal degeneration in a genetically engineered knockout mouse, and in a naturally occurring form of canine progressive retinal atrophy considered to be the equivalent of retinitis pigmentosa in humans (RP). This study was undertaken to investigate if SLC4A3 coding variants were implicated in human retinal degeneration. SLC4A3 exons were amplified and sequenced in 200 patients with autosomal recessive retinal degeneration who had no known molecular diagnosis for their condition, which included 197 unrelated individuals with suspected RP and three individuals with other forms of retinal disease. Three rare variants were identified that were predicted to be potentially pathogenic, however each variant was heterozygous in a single patient and therefore not considered disease-causing in isolation. Of these three variants, SNP-3 was the rarest, with an allele frequency of 7.06 x 10(-5) (>46,000 exomes from the ExAC database). In conclusion, no compound heterozygous or homozygous potentially pathogenic variants were identified that would account for recessive RP or retinal degeneration in this cohort, however the possibility remains that the rare variants identified could be acting with as yet undiscovered mutations in introns or regulatory regions. SLC4A3 remains an excellent candidate gene for human retinal degeneration, and with the advent of whole exome and whole genome sequencing of cohorts of molecularly unsolved patients with syndromic and non-syndromic forms of retinal degeneration, SLC4A3 may yet be implicated in human disease

    Parentage test in broad-snouted caimans (Caiman latirostris, Crocodylidae) using microsatellite DNA

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    In this study, microsatellite markers, developed for Alligator mississipiensis and Caiman latirostris, were used to assess parentage among individuals from the captive colony of Caiman latirostris at the University of São Paulo, in Piracicaba, São Paulo, Brazil. Many of the females in the colony were full siblings, which made maternal identification difficult due to genotypic similarity. Even so, the most likely mother could be identified unambiguously among offspring in most of the clutches studied. Two non-parental females displayed maternal behavior which would have misled managers in assigning maternity based on behavior alone. This set of variable loci demonstrates the utility of parentage testing in captive propagation programs

    UCL Qualitative health research symposium 2017: collaboration in qualitative health research

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    In recent years, there have been increasing calls for collaboration between academia and the wider healthcare community in health research. This is largely driven by efforts to engage the public in the “co-production” of evidence-based healthcare and healthcare decision-making, as well as penetrate borders between disciplines. As a result, traditional "lone researcher" models of qualitative health research have shifted to include research teams which are increasingly made up of qualitative researchers alongside quantitative researchers, members of the public, health professionals, policy-makers and other stakeholders. In these ways, health research is assumed to be more relevant, ethically justifiable, and broadly applicable. However, such collaborations may be complex and may create challenges. To date, there has been limited critical consideration of these challenges and little is known about the assumptions and effectiveness of these collaborations. We organised a one-day symposium to explore themes related to engagement, co-production and collaborative meaning making in qualitative health research. The oral presentations and posters used examples of collaborative studies to critically explore the processes used to carry out research as a diverse team. The discussions throughout the day alluded to the need to understand the multiple forms and levels of patient and public involvement in research, and distinguish between patient representatives and members of the public. Collaborative research requires flexibility, and might lead the researcher to occupy “mediating” roles such as that of the “cultural broker” or “boundary spanner”. The symposium created a forum to critically reflect on current approaches to inform improved ways of collaborating and engaging with diverse stakeholders to meaningfully impact on health and healthcare delivery. We should continue to search for ways to unpack the concept of “collaboration” to identify the purpose of collaborative relationships, the required activities and the actors involved
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