1,721,010 research outputs found
Lungenfunktionsveränderungen asbestexponierter Arbeiter, eine systematische Übersicht und Metaanalyse
No full textBackground: A continuing controversy exists about whether, asbestos exposure is associated with significant lung function impairments when major radiological abnormalities are lacking. We conducted a systematic review and meta-analysis in order to assess whether asbestos exposure is related to impairment of lung function parameters independently of the radiological findings.
Methods: MEDLINE was searched from its inception up to April 2010. We included studies that assessed lung function parameters in asbestos exposed workers and stratified subjects according to radiological findings. Estimates of VC, FEV1 and FEV1/VC with their dispersion measures were extracted and pooled.
Results: Our meta-analysis with data from 9,921 workers exposed to asbestos demonstrates a statistically significant reduction in VC, FEV1 and FEV1/VC, even in those workers without radiological changes. Less severe lung function impairments are detected if the diagnoses are based on (high resolution) computed tomography rather than the
less sensitive X-ray images. The degree of lung function impairment was partly related to the proportion of smokers included in the studies.
Conclusions: Asbestos exposure is related to restrictive and obstructive lung function impairment. Even in the absence of radiological evidence of parenchymal or pleural diseases there is a trend for functional impairment
Asthma bronchiale und COPD verursacht durch Irritanzien am Arbeitsplatz – ein evidenzbasierter Ansatz
No full textWRA is a frequent occupational lung disease in an industrialized environment. It is subdivided into OA and work-aggravated asthma. The main objective of this study was to give an evidence-based overview of the literature on irritative agents, professions or work-sites causing irritant-induced OA and/or occupational COPD.
The key question of this study was: Which respiratory airborne agents cause irritant-induced OA or occupational COPD, and on what level of evidence can such findings be supported?
A database search provided 450 studies dealing with irritant-induced OA or occupational COPD.
An evidence-based approach was realized by applying two suitable grading systems. The modified SIGN grading was used for rating the quality of all considered studies individually. The modified RCGP three-star system was applied for grading each irritant agent with regard to cause irritant-induced OA or occupational COPD. This permitted all study types of different scientific strength.
Irritant-induced OA was the focus of most studies and was the predominant diagnosis. Different ways of confirming irritant-induced OA were used by the author. SIC and lung function tests were the most important diagnostic instruments. Occupational COPD was mainly not the specified target. Some studies described respiratory symptoms such as chronic bronchitis which may be associated with COPD. One of the few studies which focused on occupational COPD was a large retrospective cohort study on diesel exhaust.
According to the SIGN grading system more than half of the publications represent non-scientific studies and were rated with the lowest level, this comprises case reports/case series and occupational disease statistics. The highest level realized by SIGN grading was 2+, which means a well-conducted scientific study with a low risk of confounding or bias. On the basis of the modified RCGP three-star grading, strengths of evidence of the individual/ mixed agent, profession or work-site could be identified. The highest evidence achieved was two stars.
Only a few agents, professions or work-sites were found with moderate evidence level for causing irritant-induced OA or occupational COPD. These include chlorine, welding fumes or construction work (see Table 5, chapter “Results”). For most agents only limited evidence was found, e.g. for acids, acrylates or diesel exhaust (see Table 7, chapter “Results”).
It is possible that not all relevant studies were found in the literature search. Other limitations of this work may be due to the possibility that selection and information bias cannot be totally excluded.
In conclusion, the diagnosis of irritant-induced OA should be especially considered if there has been a single or repeated exposures to high concentration or chronic exposures to moderate (in the TLV ranges) concentrations of an identified irritative agent without evidence of an IgE-mediated pathomechanism.
The diagnosis of occupational COPD should be considered if there have been mainly chronic exposures to an agent capable of causing occupational COPD, not reversible chronic airway disease is found, there is a temporal relationship between the period of exposure and development of COPD, and no other cause of COPD is obviously present.
Based on the estimated population-attributable risk due to occupational exposures for OA and occupational COPD, which are still considerably underreported occupational diseases, strategies designed to prevent these disorders should receive high priority in global efforts to reduce their burden. This study might amplify adequate diagnostic procedures and may help to optimize primary and secondary prevention. Since there is still a lack of knowledge on the causative role of irritant agents and conditions, more research should focus on this issue in order to improve further respective evidence-based diagnostic procedures and preventive strategies
Lung functional failures of aircraft crew members after “fume event”: diagnostics and biomonitoring
No full textEducators stress and job strain caused by night employment - Results of a questionnaire and a field study
No full textVerbesserung der Latex-Allergie-Diagnostik mittels rekombinanter Allergene
No full textIn Deutschland werden derzeit pro Jahr ca. 200 Anzeigen wegen des Verdachts auf eine latexbedingte Berufskrankheit der Haut oder der Atemwege erstattet. Die Hauttestdiagnostik erfolgt mit nativen Extrakten der Latexmilch. Für die serologische Diagnostik, z.B. mittels CAP, werden bisher natürliche Allergene - z.T. bereits ergänzt durch rekombinantes Hev b 5- eingesetzt. Schwankungen hinsichtlich der Qualität und der Quantität der einzelnen Allergene in den Extrakten und der wenig standardisierten Extraktionsverfahren können zu falsch postitiven oder falsch negativen Befunden führen. Ziel dieser Studie war daher die Etablierung eines sensitiven und spezifischen, auf rekombinaten Latexallergenen basierenden Assays, der eine leichte Standardisierbarkeit und eine Unabhängigkeit von den Naturextrakten ermöglicht.
In der vorliegenden Arbeit haben wir aus Blättern des Gummibaums Hevea brasiliensis die Gesamt-RNA isoliert. Mittels spezifischer Primer wurde anschließend cDNA bekannter Latexallergene über RT-PCR amplifiziert und in den bakteriellen Expressionsvektor pQE30UA kloniert. Die Überprüfung der Identität des Inserts erfolgte anhand von Sequenzierungen. Die Lysate der rekombinanten Latexallergenen-exprimierenden Bakterien wurden im ELISA direkt zur Beschichtung der ELISA-Platten eingesetzt. Lysate der GPDH-exprimierenden Bakterien dienten zur Hintergrunderfassung. Für die CAP-Analytik wurde das rekombinate Latexallergen Hev b 6 über Ni-NTA-Agarose gereinigt, biotinyliert und an Streptavidin-CAPs gekoppelt. Das vorhandene, gut definierte Kollektiv aus 120 Beschäftigten im Gesundheitswesen mit anamnestichen Hinweisen auf eine Latexallergie wurde mittels ELISA und teilweise mittels CAP-Analytik auf spezifische Antikörper (IgE) gegen Latex untersucht. Die Ergebnisse dieser Studie mit den rekombinanten Allergenen bestätigten in verschiedenen Teilkolektiven aus dem Gesundheitswesen im Wesentlichen die bisherigen Ergebnisse in der Literatur, die überwiegend mit nativen Latexallergenen durchgeführt wurden.
Als Minor-Allergene (<50% der Patienten sensibilisiert) wurden rHev b 1, 3, 7 und 8 identifiziert. Dagegen stellen rHev b 5 und 6 Majorallergene dar. Auch das kürzlich bekannt gewordenen Hev b 13 konnte in seiner nativen Form als Major-Allergen identifiziert werden. Im Gegensatz hierzu zeigte das rekombinante Hev b 13 eine wesentlich geringere Allergenität.
Der Einsatz rekombinanter Allergene als Basis für eine verbesserte Diagnostik der Latexallergie vereinfacht die Standardisierung, gewährleistet Unabhängigkeit von den Naturextrakten und macht komplizierte Reinigungsverfahren hinfällig. Rekombinante Allergene ermöglichen darüber hinaus die Durchführung einer am individuellen Sensibilisierungsmuster orientierten spezifischen Immuntherapie, Voraussetzung für derartige Anwendungen ist jedoch, dass die rekombinante Form der Allergene sich immunologisch gleichartig wie die native Form verhält und auch die IgE-Antikörper der Latexallergene binde. Dies lies sich in den vorliegenden Untersuchung für Hev b 1, 3, 5, 6, 7 und 8, nicht jedoch für Hev b 13 belegen
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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