484 research outputs found

    Emerging challenges of the impacts of pharmaceuticals on aquatic ecosystems: A diatom perspective.

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    Pharmaceuticals are a ubiquitous group of emerging pollutants of considerable importance due to their biological potency and potential to elicit effects in wildlife and humans. Pharmaceuticals have been quantified in terrestrial, marine, fresh, and transitional waters, as well as the fauna and macro-flora that inhabit them. Pharmaceuticals can enter water ways through different human and veterinary pathways with traditional wastewater treatment, unable to completely remove pharmaceuticals, discharging often unknown quantities to aquatic ecosystems. However, there is a paucity of available information regarding the effects of pharmaceuticals on species at the base of aquatic food webs, especially on phytoplankton, with research typically focussing on fish and aquatic invertebrates. Diatoms are one of the main classes of phytoplankton and are some of the most abundant and important organisms in aquatic systems. As primary producers, diatoms generate ∼40 % of the world's oxygen and are a vital food source for primary consumers. Diatoms can also be used for bioremediation of polluted water bodies but perhaps are best known as bio-indicators for water quality studies. However, this keystone, non-target group is often ignored during ecotoxicological studies to assess the effects of pollutants of concern. Observed effects of pharmaceuticals on diatoms have the potential to be used as an indicator of pharmaceutical-induced impacts on higher trophic level organisms and wider ecosystem effects. The aim of this review is to present a synthesis of research on pharmaceutical exposure to diatoms, considering ecotoxicity, bioremediation and the role of diatoms as bio-indicators. We highlight significant omissions and knowledge gaps which need addressing to realise the potential role of diatoms in future risk assessment approaches and help evaluate the impacts of pharmaceuticals in the aquatic environment at local and global scales

    Limited replication of human cytomegalovirus in a trophoblast cell line.

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    Several viruses, including human cytomegalovirus (HCMV), are thought to replicate in the placenta. However, there is little understanding of the molecular mechanisms involved in HCMV replication in this tissue. We investigated replication of HCMV in the extravillous trophoblast cell line SGHPL-4, a commonly used model of HCMV replication in the placenta. We found limited HCMV protein expression and virus replication in SGHPL-4 cells. This was associated with a lack of trophoblast progenitor cell protein markers in SGHPL-4 cells, suggesting a relationship between trophoblast differentiation and limited HCMV replication. We proposed that limited HCMV replication in trophoblast cells is advantageous to vertical transmission of HCMV, as there is a greater opportunity for vertical transmission when the placenta is intact and functional. Furthermore, when we investigated the replication of other vertically transmitted viruses in SGHPL-4 cells we found some limitation to replication of Zika virus, but not herpes simplex virus. Thus, limited replication of some, but not all, vertically transmitted viruses may be a feature of trophoblast cells

    Inhibition of human cytomegalovirus replication by interferon alpha can involve multiple anti-viral factors

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    The shortcomings of current direct-acting anti-viral therapy against human cytomegalovirus (HCMV) has led to interest in host-directed therapy. Here we re-examine the use of interferon proteins to inhibit HCMV replication utilizing both high and low passage strains of HCMV. Pre-treatment of cells with interferon alpha (IFNα) was required for robust and prolonged inhibition of both low and high passage HCMV strains, with no obvious toxicity, and was associated with an increased anti-viral state in HCMV-infected cells. Pre-treatment of cells with IFNα led to poor expression of HCMV immediate-early proteins from both high and low passage strains, which was associated with the presence of the anti-viral factor SUMO-PML. Inhibition of HCMV replication in the presence of IFNα involving ZAP proteins was HCMV strain-dependent, wherein a high passage HCMV strain was obviously restricted by ZAP and a low passage strain was not. This suggested that strain-specific combinations of anti-viral factors were involved in inhibition of HCMV replication in the presence of IFNα. Overall, this work further supports the development of strategies involving IFNα that may be useful to inhibit HCMV replication and highlights the complexity of the anti-viral response to HCMV in the presence of IFNα

    Lymphocyte subsets and the role of Th1/Th2 balance in stressed chronic pain patients

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    Background: The complex regional pain syndrome (CRPS) and fibromyalgia (FM) are chronic pain syndromes occurring in highly stressed individuals. Despite the known connection between the nervous system and immune cells, information on distribution of lymphocyte subsets under stress and pain conditions is limited. Methods: We performed a comparative study in 15 patients with CRPS type I, 22 patients with FM and 37 age- and sex-matched healthy controls and investigated the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes. Results: Lymphocyte numbers did not differ between groups. Quantitative analyses of lymphocyte subpopulations showed a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS (p < 0.01) and FM (p < 0.05) patients as compared with healthy controls. Additionally, CRPS patients were characterized by a lower percentage of IL-2-producing T cell subpopulations reflecting a diminished Th1 response in contrast to no changes in the Th2 cytokine profile. Conclusions: Future studies are warranted to answer whether such immunological changes play a pathogenetic role in CRPS and FM or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients. Copyright (c) 2008 S. Karger AG, Basel

    Priority for the Worse Off and the Social Cost of Carbon

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    The social cost of carbon (SCC) is a monetary measure of the harms from carbon emission. Specifically, it is the reduction in current consumption that produces a loss in social welfare equivalent to that caused by the emission of a ton of CO2. The standard approach is to calculate the SCC using a discounted-utilitarian social welfare function (SWF)—one that simply adds up the well-being numbers (utilities) of individuals, as discounted by a weighting factor that decreases with time. The discounted-utilitarian SWF has been criticized both for ignoring the distribution of well-being, and for including an arbitrary preference for earlier generations. Here, we use a prioritarian SWF, with no time-discount factor, to calculate the SCC in the integrated assessment model RICE. Prioritarianism is a well-developed concept in ethics and theoretical welfare economics, but has been, thus far, little used in climate scholarship. The core idea is to give greater weight to well-being changes affecting worse off individuals. We find substantial differences between the discounted-utilitarian and non-discounted prioritarian SCC

    Laboratory observations of double-diffusive convection using high-frequency broadband acoustics

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    Author Posting. © The Author(s), 2008. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Experiments in Fluids 46 (2009): 355-364, doi:10.1007/s00348-008-0570-9.High-frequency broadband (200-300 kHz) acoustic scattering techniques have been used to observe the diffusive regime of double-diffusive convection in the laboratory. Pulse compression signal processing techniques allow 1) centimetre-scale interface thickness to be rapidly, remotely, and continuously measured, 2) the evolution, and ultimate merging, of multiple interfaces to be observed at high-resolution, and 3) convection cells within the surrounding mixed layers to be observed. The acoustically measured interface thickness, combined with knowledge of the slowly-varying temperatures within the surrounding layers, in turn allows the direct estimation of double-diffusive heat and buoyancy fluxes. The acoustically derived interface thickness, interfacial fluxes and migration rates are shown to support established theory. Acoustic techniques complement traditional laboratory sampling methods and provide enhanced capabilities for observing the diffusive regime of double-diffusion in the ocean.Funding for this project was provided by the Ocean Acoustics program at the Office of Naval Research, and by the WHOI Cecil and Ida Greene Technology Award

    The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin motifs) family

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    The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin motifs) enzymes are secreted, multi-domain matrix-associated zinc metalloendopeptidases that have diverse roles in tissue morphogenesis and patho-physiological remodeling, in inflammation and in vascular biology. The human family includes 19 members that can be sub-grouped on the basis of their known substrates, namely the aggrecanases or proteoglycanases (ADAMTS1, 4, 5, 8, 9, 15 and 20), the procollagen N-propeptidases (ADAMTS2, 3 and 14), the cartilage oligomeric matrix protein-cleaving enzymes (ADAMTS7 and 12), the von-Willebrand Factor proteinase (ADAMTS13) and a group of orphan enzymes (ADAMTS6, 10, 16, 17, 18 and 19). Control of the structure and function of the extracellular matrix (ECM) is a central theme of the biology of the ADAMTS, as exemplified by the actions of the procollagen-N-propeptidases in collagen fibril assembly and of the aggrecanases in the cleavage or modification of ECM proteoglycans. Defects in certain family members give rise to inherited genetic disorders, while the aberrant expression or function of others is associated with arthritis, cancer and cardiovascular disease. In particular, ADAMTS4 and 5 have emerged as therapeutic targets in arthritis. Multiple ADAMTSs from different sub-groupings exert either positive or negative effects on tumorigenesis and metastasis, with both metalloproteinase-dependent and -independent actions known to occur. The basic ADAMTS structure comprises a metalloproteinase catalytic domain and a carboxy-terminal ancillary domain, the latter determining substrate specificity and the localization of the protease and its interaction partners; ancillary domains probably also have independent biological functions. Focusing primarily on the aggrecanases and proteoglycanases, this review provides a perspective on the evolution of the ADAMTS family, their links with developmental and disease mechanisms, and key questions for the future

    Outcome and human epidermal growth factor receptor (HER) 1–4 status in invasive breast carcinomas with proliferation indices evaluated by bromodeoxyuridine labelling

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    BACKGROUND: We have shown previously that whereas overexpression of human epidermal growth factor receptor (HER)1, HER2 and HER3 is associated with poor prognosis in breast cancer, HER4 is associated with a good prognosis. Cell proliferation is a key component of aggressive cancers and is driven by growth factors. In this study, bromodeoxyuridine (BrdU)-derived proliferation indices are correlated with clinical outcome and HER1–4 status for further clarification of the differing roles for the HER family at a biological level. METHODS: Seventy-eight invasive breast cancers had BrdU labelling in vivo to determine the BrdU labelling index (BLI) and the potential tumour doubling time (T(pot)). Long-term clinical follow-up was available for these patients. We used immunohistochemistry to establish the HER1–4 status in 55 patients from the BrdU cohort. RESULTS: We demonstrate a significant correlation between high BLI values and breast cancer-specific death (P = 0.0174). Low T(pot )times were also significantly correlated with breast cancer-specific death (P = 0.0258). However, BLI did not independently predict survival in Cox's multiple regression analysis when combined with other prognostic factors such as size, grade and nodal status. Tumours found to be positive for HER1, HER2 or HER3 had significantly (P = 0.041) higher labelling indices, with HER1 also showing significantly higher indices when considered independently (P = 0.024). Conversely, HER4 positivity was significantly correlated (P = 0.013) with low BLI values, in line with previous data associating this receptor with good prognosis tumours. CONCLUSIONS: These results support the hypothesis that HER1–3 are associated with driving tumour proliferation, whereas HER4 is involved in a non-proliferative or even protective role

    Personal values and involvement in problem behaviors among Bahamian early adolescents: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Few studies, particularly in developing countries, have explored the relationship between adolescents and parental values with adolescent problem behaviors. The objectives of the study are to (1) describe adolescents' personal values, their problem behaviors, and the relationships thereof according to gender and (2) examine the relationship between parental values, adolescent values, and adolescents' problem behaviors among sixth-grade students and one of their parents.</p> <p>Methods</p> <p>The data used in these analyses were from the baseline assessment of a school-based HIV risk reduction intervention being conducted and evaluated among sixth grade students and one of their parents across 9 elementary schools in The Bahamas. Personal values were measured by the Portrait Values Questionnaire (PVQ). Seven reported problem behaviors were queried from the students, which included physical fight with a friend, drank alcohol, beer, or wine, smoked a cigarette, pushed or carried any drugs, carried a gun, knife, screwdriver or cutlass to use as a weapon, had sex and used marijuana or other illicit drugs over the past 6 months. Multilevel modeling for binary data was performed to estimate the associations between adolescent and parental values and adolescent problem behaviors.</p> <p>Results</p> <p>Among 785 students, 47% of the students reported at least one problem behavior. More boys (54%) reported having one or more problem behaviors than girls (41%, p < 0.01). Boys compared to girls expressed a higher level of self-enhancement (means score: 36.5 vs. 35.1; p = 0.03), while girls expressed a higher level of self-transcendence (42.3 vs. 40.7; p = 0.03). The results of multilevel modeling indicates that boys with a higher level of self-enhancement and girls with a higher level of openness to change and a lower level of conservation were more likely to report engagement in problem behaviors. Only two parental values (self-transcendence and conservation) were low or modestly correlated with youth' values (openness to change and self-enhancement). Parental-reported values documented limited association on adolescents' reported values and behaviors.</p> <p>Conclusion</p> <p>In designing interventions for reducing adolescents' problem behaviors, it may be important to understand the values associated with specific problem behaviors. Further exploration regarding lack of association between adolescent and parental values and problem behaviors is needed.</p

    Neonatal Mortality and Prevalence of Practices for Newborn Care in a Squatter Settlement of Karachi, Pakistan: A Cross-Sectional Study

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    Background: During the past two decades there has been a sustained decline in child and infant mortality, however neonatal mortality has remained relatively unchanged. Almost all neonatal deaths (99%) occur in developing countries, where the majority are delivered at homes. Evidence suggests that these deaths could be prevented by simple, inexpensive practices and interventions during the pregnancy, delivery and postnatal period. In Pakistan over the last decade extensive efforts have been made by the international donors and government to implement these practices. However, limited attempts have been made to explore if these efforts have made a difference at the grass root level. This study assessed the burden of neonatal mortality and prevalence of practices for newborn care in a squatter settlement of Karachi, Pakistan.Methodology/Principal Findings: A community based cross-sectional study was performed. A pre-tested structured questionnaire was administered to 565 women who had recently delivered. Information was collected on neonatal morbidity, mortality and practices of women regarding care during pregnancy, child birth and for newborn, till 28th day of birth. Although 70% of women mentioned receiving antenatal care by a skilled provider, only 54.5% had four or more visits. Tetanus toxoid was received by 79% of women while only 56% delivered at a health care facility by a skilled attendant. Newborn care practices like bathing the baby immediately after birth (56%), giving pre-lacteals (79.5%), late initiation of breast feeding (80.3%), application of substances on umbilical cord (58%) and body massage (89%) were common. Most neonates (81.1%) received BCG injection and polio drops after birth. Neonatal mortality rate was 27/1000 live births with the majority of deaths occurring during the first three days of life.Conclusion: Even after years of efforts by government and nongovernmental sector to reduce newborn morbidity and mortality, inadequate antenatal care, home deliveries and unhealthy newborn care practices are highly prevalent. This leads us to important questions of why practices and behaviors have not changed. Who is responsible and what strategies are needed to bring this change
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