1,721,059 research outputs found
Efficacy of serum procalcitonin in evaluating severity of community-acquired pneumonia in childhood.
No full textCatching the pneumococcus : Studies focusing on carriage, epidemiology and microbiological methods
Full text linkAbstractThe purpose of this study was to develop sensitive and specific laboratory diagnostic methods for the demonstration of pneumococcal surface antigens or pneumococcus-specific antibodies in clinical samples. The work took account of epidemiological aspects of both pneumococcal disease and nasopharyngeal carriage of pneumococcus.We first compared the sensitivity of pneumococcal culture and antigen detection methods in nasopharyngeal samples in a developing country setting and then investigated the possibility of improving the sensitivity of the antigen detection by introducing an enrichment step in the procedure. — Further investigations were designed to determine the validity of pneumolysin-specific immune complex bound antibody assay as a tool for diagnosing pneumococcal ALRI in a developing country setting. Finally, we developed an enzyme immunoassay for the detection of pneumococcal capsular polysaccharide antigens, using type-specific antibodies produced in-house in rabbits through immunisation with an in-house-produced pneumococcal whole cell vaccine. The method was tested in nasopharyngeal and middle ear fluid samples.The first results indicated that antigen detection might be more sensitive than culture in demonstrating pneumococci in URT, particularly in children with prior antimicrobial therapy. Antigen detection is a feasible method for studies on pneumococci in developing countries. For type-specific demonstration of S. pneumoniae, detection of pneumococcal antigen after an enrichment step proved a sensitive method that can be applied for epidemiologic study purposes, e.g., in vaccine trials, in areas without ready access to a good microbiology laboratory.Determination of IC-bound pneumolysin IgG antibodies appears to be a useful method for species-specific diagnosis of pneumococcal infections. The results indicating pneumococcal aetiology in ALRI patients in this study compare well with the best results obtained by the use of lung aspirates. Increasing the number of serial samples improves the sensitivity of the assay, but even two samples provide more positive findings than other methods currently in routine use. Criteria of positivity need to be confirmed in subsequent larger studies with both healthy controls and patients with confirmed pneumococcal disease. It is also important to control the findings in patients with pneumonia of non-pneumococcal origin.The novel enzyme immunoassay was shown to work well with enrichment culture samples, with an almost 100% sensitivity compared with the culture. Middle ear fluid samples were too diluted for the enzyme immunoassay method used, and only 74% sensitivity compared with culture was achieved. Provided that adequate samples can be obtained, the method will be a useful complement to the current laboratory methods used to diagnose pneumococcal disease.With the existence of a broad spectrum of microbiological and immunological methods, it is imperative to seek international consensus for standard methods to demonstrate pneumococcus. Otherwise it is very difficult to compare results from different clinical studies. A WHO Working Group recently proposed a standard method for detecting upper respiratory carriage of pneumococcus, but a lot of work remains to be done in other areas of research on pneumococcal infections.Academic Dissertation to be presented with the assent of the Faculty of Medicine, University of Oulu, for public discussion in the Great Auditorium of the Faculty of Medicine, on June 28th, 2003, at 12 noon.Abstract
The purpose of this study was to develop sensitive and specific laboratory diagnostic methods for the demonstration of pneumococcal surface antigens or pneumococcus-specific antibodies in clinical samples. The work took account of epidemiological aspects of both pneumococcal disease and nasopharyngeal carriage of pneumococcus.
We first compared the sensitivity of pneumococcal culture and antigen detection methods in nasopharyngeal samples in a developing country setting and then investigated the possibility of improving the sensitivity of the antigen detection by introducing an enrichment step in the procedure. — Further investigations were designed to determine the validity of pneumolysin-specific immune complex bound antibody assay as a tool for diagnosing pneumococcal ALRI in a developing country setting. Finally, we developed an enzyme immunoassay for the detection of pneumococcal capsular polysaccharide antigens, using type-specific antibodies produced in-house in rabbits through immunisation with an in-house-produced pneumococcal whole cell vaccine. The method was tested in nasopharyngeal and middle ear fluid samples.
The first results indicated that antigen detection might be more sensitive than culture in demonstrating pneumococci in URT, particularly in children with prior antimicrobial therapy. Antigen detection is a feasible method for studies on pneumococci in developing countries. For type-specific demonstration of S. pneumoniae, detection of pneumococcal antigen after an enrichment step proved a sensitive method that can be applied for epidemiologic study purposes, e.g., in vaccine trials, in areas without ready access to a good microbiology laboratory.
Determination of IC-bound pneumolysin IgG antibodies appears to be a useful method for species-specific diagnosis of pneumococcal infections. The results indicating pneumococcal aetiology in ALRI patients in this study compare well with the best results obtained by the use of lung aspirates. Increasing the number of serial samples improves the sensitivity of the assay, but even two samples provide more positive findings than other methods currently in routine use. Criteria of positivity need to be confirmed in subsequent larger studies with both healthy controls and patients with confirmed pneumococcal disease. It is also important to control the findings in patients with pneumonia of non-pneumococcal origin.
The novel enzyme immunoassay was shown to work well with enrichment culture samples, with an almost 100% sensitivity compared with the culture. Middle ear fluid samples were too diluted for the enzyme immunoassay method used, and only 74% sensitivity compared with culture was achieved. Provided that adequate samples can be obtained, the method will be a useful complement to the current laboratory methods used to diagnose pneumococcal disease.
With the existence of a broad spectrum of microbiological and immunological methods, it is imperative to seek international consensus for standard methods to demonstrate pneumococcus. Otherwise it is very difficult to compare results from different clinical studies. A WHO Working Group recently proposed a standard method for detecting upper respiratory carriage of pneumococcus, but a lot of work remains to be done in other areas of research on pneumococcal infections
Association of respiratory syncytial virus infection with asthma and atopic allergy
Full text linkAbstractRespiratory syncytial virus (RSV) infection may be associated with the development of asthma and atopy. The aim of the present study was to investigate this association and the related immunological mechanisms.Seventy-six children admitted to Oulu University Hospital in 1991–1994 for an RSV infection at an age of less than 12 months and healthy controls were called for a visit at the age of 6–10 years. Twenty subjects (26%) had asthma compared with 12 controls (16%) (difference 11%, 95% confidence interval (CI) –3% to 24%). Asthma had been diagnosed significantly earlier in the subjects. Eight per cent of the subjects had at least one positive skin prick test as compared with 43% of the controls (difference –35%, 95% CI –50% to –19%). Serum concentrations of interferon-γ and soluble intercellular adhesion molecule -1 were significantly higher among the subjects than among the controls and among the subjects with asthma or current wheezing than among the corresponding controls.All children born in Finland in 1986–1995 were arranged in birth cohorts by month and year of birth and grouped by exposure to an RSV epidemic at age 0–6 months, resulting in 97 exposed and 23 unexposed cohorts. The proportions of children taking asthma medication or receiving special reimbursement for asthma medication in 1995–2002 were similar in the unexposed and exposed cohorts.Altogether 47 children born between August and November 2001 with a cord blood sample taken were admitted to hospital (n = 26) or seen in an outpatient department (n = 21) for RSV infection before the age of six months. Twenty-eight children had some other respiratory viral infection and 84 children formed a group of healthy controls. High scores on a factor combining the cord blood interleukin-6 and interleukin-8 responses (as derived by factor analysis) were shown in logistic regression analysis to predict hospitalization for RSV infection by comparison with the healthy controls (odds ratio 2.29, 95% CI 1.21 to 4.33).We suggest that RSV does not induce asthma but inborn features of immunity affect the severity of RSV infection and the postinfectious development of asthma.Academic dissertation to be presented, with the assent of the Faculty of Medicine of the University of Oulu, for public defence in Auditorium 12 of the Department of Paediatrics, on June 13th, 2008, at 12 noon.Abstract
Respiratory syncytial virus (RSV) infection may be associated with the development of asthma and atopy. The aim of the present study was to investigate this association and the related immunological mechanisms.
Seventy-six children admitted to Oulu University Hospital in 1991–1994 for an RSV infection at an age of less than 12 months and healthy controls were called for a visit at the age of 6–10 years. Twenty subjects (26%) had asthma compared with 12 controls (16%) (difference 11%, 95% confidence interval (CI) –3% to 24%). Asthma had been diagnosed significantly earlier in the subjects. Eight per cent of the subjects had at least one positive skin prick test as compared with 43% of the controls (difference –35%, 95% CI –50% to –19%). Serum concentrations of interferon-γ and soluble intercellular adhesion molecule -1 were significantly higher among the subjects than among the controls and among the subjects with asthma or current wheezing than among the corresponding controls.
All children born in Finland in 1986–1995 were arranged in birth cohorts by month and year of birth and grouped by exposure to an RSV epidemic at age 0–6 months, resulting in 97 exposed and 23 unexposed cohorts. The proportions of children taking asthma medication or receiving special reimbursement for asthma medication in 1995–2002 were similar in the unexposed and exposed cohorts.
Altogether 47 children born between August and November 2001 with a cord blood sample taken were admitted to hospital (n = 26) or seen in an outpatient department (n = 21) for RSV infection before the age of six months. Twenty-eight children had some other respiratory viral infection and 84 children formed a group of healthy controls. High scores on a factor combining the cord blood interleukin-6 and interleukin-8 responses (as derived by factor analysis) were shown in logistic regression analysis to predict hospitalization for RSV infection by comparison with the healthy controls (odds ratio 2.29, 95% CI 1.21 to 4.33).
We suggest that RSV does not induce asthma but inborn features of immunity affect the severity of RSV infection and the postinfectious development of asthma
Acute rhinosinusitis during upper respiratory infection in children
Full text linkAbstractAcute rhinosinusitis is estimated to be one of the most common diseases in childhood. Still, the diagnostics and clinical relevance of this disease are controversial.Bacterial rhinosinusitis cannot be differentiated from mere rhinitis on clinical grounds alone. Abnormal radiologic findings have been found to be common in child and adult volunteers without sinus symptoms and in adults during viral upper respiratory infection. In children, the results of the few placebo-controlled studies on the benefit of antimicrobial treatment of clinically diagnosed acute rhinosinusitis are controversial. Bacteriologic cultures obtained from the middle meatus by rigid nasal endoscopy have been introduced as a way to determine the bacteriology of the maxillary sinus in adults, but they have not been studied in children with acute symptoms. In this thesis, incidental paranasal abnormalitites were found to be common in healthy school children examined by magnetic resonance imaging (MRI). Some of these abnormalities resolved during a follow-up period of 6 months, but new abnormalities appeared in some children. MRI abnormalities of the paranasal sinuses were found to be much more common in children with acute upper respiratory infections, and most of these abnormalities resolve spontaneously. Children with acute rhinosinusitis confirmed clinically and by imaging did not benefit from cefuroxime treatment as compared to placebo. Pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis) in the nasal middle meatus during acute upper respiratory infection predicted longer duration of the symptoms and signs of common cold.Based on these findings, imaging methods should not be used in the diagnostics of acute rhinosinusitis in children. Similarily, incidental imaging findings of abnormalities in the paranasal sinuses or in children with symptoms of acute rhinosinusitis are not an indication for antimicrobial treatment. Because middle meatal pathogenic bacteria were found to predict prolonged symptoms of upper respiratory infection, a randomized controlled trial is needed to evaluate the clinical value of middle meatal culture in identifying the children who would benefit from antimicrobial treatment during acute respiratory infection.Academic Dissertation to be presented with the assent of the Faculty of Medicine, University of Oulu, for public discussion in the Auditorium 7 of Oulu University Hospital, on November 18th, 2005, at 12 noonAbstract
Acute rhinosinusitis is estimated to be one of the most common diseases in childhood. Still, the diagnostics and clinical relevance of this disease are controversial.
Bacterial rhinosinusitis cannot be differentiated from mere rhinitis on clinical grounds alone. Abnormal radiologic findings have been found to be common in child and adult volunteers without sinus symptoms and in adults during viral upper respiratory infection. In children, the results of the few placebo-controlled studies on the benefit of antimicrobial treatment of clinically diagnosed acute rhinosinusitis are controversial. Bacteriologic cultures obtained from the middle meatus by rigid nasal endoscopy have been introduced as a way to determine the bacteriology of the maxillary sinus in adults, but they have not been studied in children with acute symptoms.
In this thesis, incidental paranasal abnormalitites were found to be common in healthy school children examined by magnetic resonance imaging (MRI). Some of these abnormalities resolved during a follow-up period of 6 months, but new abnormalities appeared in some children. MRI abnormalities of the paranasal sinuses were found to be much more common in children with acute upper respiratory infections, and most of these abnormalities resolve spontaneously. Children with acute rhinosinusitis confirmed clinically and by imaging did not benefit from cefuroxime treatment as compared to placebo. Pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis) in the nasal middle meatus during acute upper respiratory infection predicted longer duration of the symptoms and signs of common cold.
Based on these findings, imaging methods should not be used in the diagnostics of acute rhinosinusitis in children. Similarily, incidental imaging findings of abnormalities in the paranasal sinuses or in children with symptoms of acute rhinosinusitis are not an indication for antimicrobial treatment. Because middle meatal pathogenic bacteria were found to predict prolonged symptoms of upper respiratory infection, a randomized controlled trial is needed to evaluate the clinical value of middle meatal culture in identifying the children who would benefit from antimicrobial treatment during acute respiratory infection
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
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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