531 research outputs found

    Significance of herpesvirus immediate early gene expression in cellular immunity to cytomegalovirus infection

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    Interstitial pneumonia linked with reactivation of latent human cytomegalovirus due to iatrogenic immunosuppression can be a serious complication of bone marrow transplantation therapy of aplastic anaemia and acute leukaemia1. Cellular immunity plays a critical role in the immune surveillance of inapparent cytomegalovirus infections in man and the mouse1−7. The molecular basis of latency, however, and the interaction between latently or recurrently infected cells and the immune system of the host are poorfy understood. We have detected a so far unknown antigen in the mouse model. This antigen is found in infected cells in association with the expression of the herpesvirus 'immediate early' genes and is recognized by cytolytic T lymphocytes (CTL)8. We now demonstrate that an unexpectedly high proportion of the CTL precursors generated in vivo during acute murine cytomegalovirus infection are specific for cells that selectively synthesize immediate early proteins, indicating an immunodominant role of viral non-structural proteins

    Geographic and ecologic heterogeneity in elimination thresholds for the major vector-borne helminthic disease, lymphatic filariasis

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    <p>Abstract</p> <p>Background</p> <p>Large-scale intervention programmes to control or eliminate several infectious diseases are currently underway worldwide. However, a major unresolved question remains: what are reasonable stopping points for these programmes? Recent theoretical work has highlighted how the ecological complexity and heterogeneity inherent in the transmission dynamics of macroparasites can result in elimination thresholds that vary between local communities. Here, we examine the empirical evidence for this hypothesis and its implications for the global elimination of the major macroparasitic disease, lymphatic filariasis, by applying a novel Bayesian computer simulation procedure to fit a dynamic model of the transmission of this parasitic disease to field data from nine villages with different ecological and geographical characteristics. Baseline lymphatic filariasis microfilarial age-prevalence data from three geographically distinct endemic regions, across which the major vector populations implicated in parasite transmission also differed, were used to fit and calibrate the relevant vector-specific filariasis transmission models. Ensembles of parasite elimination thresholds, generated using the Bayesian fitting procedure, were then examined in order to evaluate site-specific heterogeneity in the values of these thresholds and investigate the ecological factors that may underlie such variability</p> <p>Results</p> <p>We show that parameters of density-dependent functions relating to immunity, parasite establishment, as well as parasite aggregation, varied significantly between the nine different settings, contributing to locally varying filarial elimination thresholds. Parasite elimination thresholds predicted for the settings in which the mosquito vector is anopheline were, however, found to be higher than those in which the mosquito is culicine, substantiating our previous theoretical findings. The results also indicate that the probability that the parasite will be eliminated following six rounds of Mass Drug Administration with diethylcarbamazine and albendazole decreases markedly but non-linearly as the annual biting rate and parasite reproduction number increases.</p> <p>Conclusions</p> <p>This paper shows that specific ecological conditions in a community can lead to significant local differences in population dynamics and, consequently, elimination threshold estimates for lymphatic filariasis. These findings, and the difficulty of measuring the key local parameters (infection aggregation and acquired immunity) governing differences in transmission thresholds between communities, mean that it is necessary for us to rethink the utility of the current anticipatory approaches for achieving the elimination of filariasis both locally and globally.</p

    Defining Potential Therapeutic Targets in Coronavirus Disease 2019: A Cross-Sectional Analysis of a Single-Center Cohort

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    OBJECTIVES: Multiple mechanisms have been proposed to explain disease severity in coronavirus disease 2019. Therapeutic approaches need to be underpinned by sound biological rationale. We evaluated whether serum levels of a range of proposed coronavirus disease 2019 therapeutic targets discriminated between patients with mild or severe disease. DESIGN: A search of ClinicalTrials.gov identified coronavirus disease 2019 immunological drug targets. We subsequently conducted a retrospective observational cohort study investigating the association of serum biomarkers within the first 5 days of hospital admission relating to putative therapeutic biomarkers with illness severity and outcome. SETTING: University College London, a tertiary academic medical center in the United Kingdom. PATIENTS: Patients admitted to hospital with a diagnosis of coronavirus disease 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-six patients were recruited, 44 (51%) with mild disease and 42 (49%) with severe disease. We measured levels of 10 cytokines/signaling proteins related to the most common therapeutic targets (granulocyte-macrophage colony-stimulating factor, interferon-α2a, interferon-β, interferon-γ, interleukin-1β, interleukin-1 receptor antagonist, interleukin-6, interleukin-7, interleukin-8, tumor necrosis factor-α), immunoglobulin G antibodies directed against either coronavirus disease 2019 spike protein or nucleocapsid protein, and neutralization titers of antibodies. Four-hundred seventy-seven randomized trials, including 168 different therapies against 83 different pathways, were identified. Six of the 10 markers (interleukin-6, interleukin-7, interleukin-8, interferon-α2a, interferon-β, interleukin-1 receptor antagonist) discriminated between patients with mild and severe disease, although most were similar or only modestly raised above that seen in healthy volunteers. A similar proportion of patients with mild or severe disease had detectable spike protein or nucleocapsid protein immunoglobulin G antibodies with equivalent levels between groups. Neutralization titers were higher among patients with severe disease. CONCLUSIONS: Some therapeutic and prognostic biomarkers may be useful in identifying coronavirus disease 2019 patients who may benefit from specific immunomodulatory therapies, particularly interleukin-6. However, biomarker absolute values often did not discriminate between patients with mild and severe disease or death, implying that these immunomodulatory treatments may be of limited benefit

    Treatment of symptomatic macromastia in a breast unit

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    BACKGROUND: Patients suffering from symptomatic macromastia are usually underserved, as they have to put up with very long waiting lists and are usually selected under restrictive criteria. The Oncoplastic Breast Surgery subspeciality requires a cross-specialty training, which is difficult, in particular, for trainees who have a background in general surgery, and not easily available. The introduction of reduction mammaplasty into a Breast Cancer Unit as treatment for symptomatic macromastia could have a synergic effect, making the scarce therapeutic offer at present available to these patients, who are usually treated in Plastic Departments, somewhat larger, and accelerating the uptake of oncoplastic training as a whole and, specifically, the oncoplastic breast conserving procedures based on the reduction mammaplasty techniques such as displacement conservative techniques and onco-therapeutic mammaplasty. This is a retrospective study analyzing the outcome of reduction mammaplasty for symptomatic macromastia in our Breast Cancer Unit. METHODS: A cohort study of 56 patients who underwent bilateral reduction mammaplasty at our Breast Unit between 2005 and 2009 were evaluated; morbidity and patient satisfaction were considered as end points. Data were collected by reviewing medical records and interviewing patients. RESULTS: Eight patients (14.28%) presented complications in the early postoperative period, two of them being reoperated on. The physical symptoms disappeared or significantly improved in 88% of patients and the degree of satisfaction with the care process and with the overall outcome were really high. CONCLUSION: Our experience of the introduction of reduction mammaplasty in our Breast Cancer Unit has given good results, enabling us to learn the use of different reduction mammaplasty techniques using several pedicles which made it possible to perform oncoplastic breast conserving surgery. In our opinion, this management policy could bring clear advantages both to patients (large-breasted and those with a breast cancer) and surgeons

    Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR

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    Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR

    How portuguese and american teachers plan for literacy instruction

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    This study explored American and Portuguese elementary teachers' preferences in planning for literacy instruction using the Language Arts Activity Grid (LAAG; Cunningham, Zibulsky, Stanovich, & Stanovich, 2009), on which teachers described their preferred instructional activities for a hypothetical 2-h language arts block. Portuguese teachers (N = 186) completed Portuguese versions of a background questionnaire and LAAG electronically, in Survey Monkey; American teachers (N = 102) completed identical English measures using paper and pencil. Results showed that teachers in both groups usually addressed comprehension and reading fluency on their LAAGs and that they also allocated the most time to these two areas. However, American teachers were more likely to include teacher-directed fluency activities, whereas Portuguese teachers were more likely to include fluency activities that were not teacher directed. Significantly more American than Portuguese teachers addressed phonics in their planning, whereas significantly more Portuguese than American teachers addressed writing processes such as revision. Both groups of educators demonstrated large variability in planning, with many teachers omitting important components of literacy identified by researchers, for writing as well as reading. The study highlights the importance of providing teachers with comprehensive, research-based core literacy curricula as well as professional development on key components of literacy. Study findings also suggest significant relationships between orthographic transparency and teachers' instructional planning.This research was supported by a 2-year grant from the Foundation Francisco Manuel dos Santos in Portugal as well as by a Connecticut State University research grant in the U.S.A. We would like to express our sincere gratitude to these funding agencies as well as to the teachers and school districts who participated in the study and sent messages of interest about our research. In addition, warm thanks to our research assistants for their help with data collection, coding, and analysis, and to Anne Cunningham for providing us with inspiration as well as guidance in this work.info:eu-repo/semantics/publishedVersio

    Genomic markers to tailor treatments: waiting or initiating?

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    The decade since the publication of the Human Genome Project draft has ended with the discovery of hundreds of genomic markers related to diseases and phenotypes. However, the project has not yet delivered on its promise to tailor treatments for individuals. The number of genomic markers in clinical practice is very small. The number of markers to guide treatment decisions is even smaller. In order to speed up discovery and validation of genomic treatment selection markers, we call for considering the brilliant potential of randomized clinical trials. If biomedical research community can collaborate in organizing large-scale consortium of clinical trials associated with well-designed biobanks, these studies would soon act as huge laboratories for investigating genomic medicine; a big step forward towards personalizing medicine

    Решение оптимизационных задач для систем массового обслуживання с отказами в условиях неопределенности

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    Построены математические модели расчета показателей качества функционирования вычислительных сетей, которые можно представить в виде сетей массового обслуживания с отказами. Сформулированы задачи оптимизации показателей качества функционирования таких сетей при заданных ограничениях на максимальную пропускную способность каналов связи и на выделяемые для модернизации сети ресурсы. Построены алгоритмы, которые позволяют решать поставленные оптимизационные задачи в рамках оговоренных ограничений
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