1,720,978 research outputs found
Trial of 2009 influenza A (H1N1) monovalent MF59-adjuvanted vaccine
No full textBACKGROUND: The 2009 pandemic influenza A (H1N1) virus has emerged to cause the first pandemic of the 21st century. Development of effective vaccines is a public health priority.METHODS: We conducted a single-center study, involving 176 adults, 18 to 50 years of age, to test the monovalent influenza A/California/2009 (H1N1) surface-antigen vaccine, in both MF59-adjuvanted and nonadjuvanted forms. Subjects were randomly assigned to receive two intramuscular injections of vaccine containing 7.5 microg of hemagglutinin on day 0 in each arm or one injection on day 0 and the other on day 7, 14, or 21; or two 3.75-microg doses of MF59-adjuvanted vaccine, or 7.5 or 15 microg of nonadjuvanted vaccine, administered 21 days apart. Antibody responses were measured by means of hemagglutination-inhibition assay and a microneutralization assay on days 0, 14, 21, and 42 after injection of the first dose.RESULTS: The most frequent local and systemic reactions were pain at the injection site and muscle aches, noted in 70% and 42% of subjects, respectively; reactions were more common with the MF59-adjuvanted vaccine than with nonadjuvanted vaccine. Three subjects reported fever, with a temperature of 38 degrees C or higher, after either dose. Antibody titers, expressed as geometric means, were higher at day 21 among subjects who had received one dose of MF59-adjuvanted vaccine than among those who had received one dose of nonadjuvanted vaccine (P<0.001 by the microneutralization assay). By day 21, hemagglutination-inhibition and microneutralization antibody titers of 1:40 or more were seen in 77 to 96% and 92 to 100% of subjects receiving MF59-adjuvanted vaccine, respectively, and in 63 to 72% and 67 to 76% of those receiving nonadjuvanted vaccine, respectively. By day 42, after two doses of vaccine, hemagglutination-inhibition and microneutralization antibody titers of 1:40 or more were seen in 92 to 100% and 100% of recipients of MF59-adjuvanted vaccine, respectively, and in 74 to 79% and 78 to 83% of recipients of nonadjuvanted vaccine, respectively.CONCLUSIONS: Monovalent 2009 influenza A (H1N1) MF59-adjuvanted vaccine generates antibody responses likely to be associated with protection after a single dose is administered. (ClinicalTrials.gov number, NCT00943358)
C-reactive protein level and microbial aetiology in patients hospitalised with acute exacerbation of COPD.
No full textBoth viruses and bacteria are thought to cause exacerbations of chronic obstructive pulmonary disease (COPD); however, the relative importance of each remains uncertain. C-reactive protein (CRP) levels increase during exacerbations but the relationship with aetiology is not established. We aimed to explore the relationship between serum CRP and the rate of detection of viruses and bacteria. This was a prospectively recruited, observational study of patients hospitalised with exacerbations of COPD. Nasopharyngeal swabs were tested for respiratory viruses by reverse transcriptase-PCR. Sputum and blood were collected for bacterial culture and urine tested for pneumococcal antigen. CRP levels were measured on sera. CRP and other factors associated with viral, bacterial or mixed detection were assessed using multiple logistic regression analysis. 264 patients with exacerbations of COPD were studied: 26% tested positive for respiratory viruses only, 13% had bacteria only, 12% had mixed viral/bacterial detection, and 49% had no pathogens detected. CRP level and temperature were strongly associated with viral detection rate (p<0.001 and p=0.004, respectively) and mixed viral/bacterial detection rate (p=0.02 and p=0.03, respectively) on multivariate analysis. Bacterial detection rate was not associated with CRP level or body temperature. This study supports the role of viruses as important aetiological agents causing exacerbations of COPD
Adults hospitalised with acute respiratory illness rarely have detectable bacteria in the absence of COPD or pneumonia; viral infection predominates in a large prospective UK sample.
No full textObjectives: Many adult patients hospitalised with acute respiratory illness have viruses detected but the overall importance of viral infection compared to bacterial infection is unclear.Methods: Patients were recruited from two acute hospital sites in Leicester (UK) over 3 successive winters. Samples were taken for viral and bacterial testing.Results: Of the 780 patients hospitalised with acute respiratory illness 345 (44%) had a respiratory virus detected. Picornaviruses were the most commonly isolated viruses (detected in 23% of all patients). Virus detection rates exceeded 50% in patients with exacerbation of asthma (58%), acute bronchitis and Influenza-like-illness (64%), and ranged from 30 to 50% in patients with an exacerbation of COPD (38%), community acquired pneumonia (36%) and congestive cardiac failure (31%). Bacterial detection was relatively frequent in patients with exacerbation of COPD and pneumonia (25% and 33% respectively) but was uncommon in all other groups. Antibiotic use was high across all clinical groups (76% overall) and only 21% of all antibiotic use occurred in patients with detectable bacteria.Conclusions: Respiratory viruses are the predominant detectable aetiological agents in most hospitalised adults with acute respiratory illness. Antibiotic usage in hospital remains excessive including in clinical conditions associated with low rates of bacterial detection. Efforts at reducing excess antibiotic use should focus on these groups as a priority.Registered International Standard Controlled Trial Number: 21521552
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Cost-effectiveness and value of information analyses of neuraminidase inhibitors for the treatment of influenza
No full textObjectives: To assess the cost-effectiveness of alternative strategies for the treatment of suspected influenza in otherwise healthy adults and to identify future research priorities using value of information analysis.Methods: A decision model was used to estimate the costs and effects, in terms of quality-adjusted life-years (QALYs) of amantadine, zanamivir, and oseltamivir for the treatment of influenza in otherwise healthy adults using data predominantly from meta-analysis of randomized controlled trials. Probabilistic sensitivity analysis using Monte Carlo simulation was conducted. The expected value of perfect information for the entire model and for individual parameters was calculated.Results: Based on mean costs and effects, zanamivir is dominated by oseltamivir. The incremental cost-effectiveness ratio for amantadine (compared with no treatment) is £11,000 and £44,000 for oseltamivir (compared with amantadine). The probability that amantadine is cost-effective at a willingness to pay of £30,000 per QALY is 0.74, falling to 0.49 at £20,000 per QALY. Global expected value of perfect information (EVPI) is £2 m over 15 years if a willingness to pay threshold of £30,000 per QALY is assumed rising to £9.6 m at £45,000 per QALY. EVPI for only one parameter exceeds £500,0000 at £30,000 per QALY: the quality of life for untreated influenza.Conclusions: At traditionally accepted values of willingness to pay for health benefits, it is unlikely that additional research would be an efficient use of scarce resources. The only exception to this would be to examine the health-related quality of life impact of influenza in an untreated patient group. If a higher threshold value were acceptable, there are a small group of parameters that may warrant further investigation. These would, however, require comparative, potentially expensive, research studies.<br/
Viral load is strongly associated with length of stay in adults hospitalised with viral acute respiratory illness
Full text linkBackground: respiratory viruses are detectable in a large proportion of adults hospitalised with acute respiratory illness. For influenza and other viruses there is evidence that viral load and persistence are associated with certain clinical outcomes but it is not known if there is an association between viral load and hospital length of stay. Methods: 306 adults hospitalised with viral acute respiratory illness were studied. Associations between viral load and length of stay were examined. Multiple linear regression analysis was performed to control for age, comorbidity, influenza vaccine status, duration of illness prior to hospitalisation, bacterial co-infection, clinical group and virus subtype.Results: high viral load was associated with a longer duration of hospitalisation for all patients (p <0.0001). This remained significant across all virus types and clinical groups and when adjusted for age, comorbidity, duration of illness prior to hospitalisation, bacterial co-infection and other factors. Conclusions: high viral loads are associated with prolonged hospital length of stay in adults with viral acute respiratory illness. This further supports existing evidence demonstrating that viral acute respiratory illness is a viral load driven process and suggests that viral load could be used in clinical practise to predict prolonged hospitalisation and prioritise antivirals. International Standard Randomised Controlled Trial Number (ISRCTN): 21521552<br/
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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