Michael Spallek

The impact of shift work induced chronic circadian disruption on IL-6 and TNF-α immune responses

AIMSleep disturbances induce proinflammatory immune responses, which might increase cardiovascular disease risk. So far the effects of acute sleep deprivation and chronic sleep illnesses on the immune system have been investigated. The particular impact of shift work induced chronic circadian disruption on specific immune responses has not been addressed so far.MethodsPittsburgh-Sleep-Quality-Index (PSQI) questionnaire and blood sampling was performed by 225 shift workers and 137 daytime workers. As possible markers the proinflammatory cytokines IL-6 and TNF-α and lymphocyte cell count were investigated. A medical examination was performed and biometrical data including age, gender, height, weight, waist and hip circumference and smoking habits were collected by a structured interview.ResultsShift workers had a significantly higher mean PSQI score than day workers (6.73 vs. 4.66; p < 0.001). Day workers and shift workers had similar serum levels of IL-6 (2.30 vs. 2.67 resp.; p = 0.276), TNF-α (5.58 vs. 5.68, resp.; p = 0.841) or lymphocytes count (33.68 vs. 32.99, resp.; p = 0.404). Furthermore there were no differences in cytokine levels (IL-6 p = 0.761; TNF-α p = 0.759) or lymphocyte count (p = 0.593) comparing the sleep quality within the cohorts. When this calculation of sleep quality was stratified by shift and day workers irrespective of their sleep quality day workers and shift workers had similar serum levels of IL-6, TNF-α or lymphocytes count. Multiple linear regression analysis showed a significant correlation of lymphocytes count and smoking habits.ConclusionShift work induces chronic sleep debt. Our data reveals that chronic sleep debt might not always lead to an activation of the immune system, as we did not observe differences in lymphocyte count or level of IL-6 or TNF-α serum concentration between shift workers and day workers. Therefore chronic sleep restriction might be eased by a long-term compensating immune regulation which (in healthy) protects against an overstimulation of proinflammatory immune mechanisms and moderates metabolic changes, as they are known from short-term sleep deprivation or sleep related breathing disorders.

Scientometric analysis and combined density-equalizing mapping of environmental tobacco smoke (ETS) research.

Background Passive exposure to environmental tobacco smoke (ETS) is estimated to exert a major burden of disease. Currently, numerous countries have taken legal actions to protect the population against ETS. Numerous studies have been conducted in this field. Therefore, scientometric methods should be used to analyze the accumulated data since there is no such approach available so far. Methods and Results A combination of scientometric methods and novel visualizing procedures were used, including density-equalizing mapping and radar charting techniques. 6,580 ETS-related studies published between 1900 and 2008 were identified in the ISI database. Using different scientometric approaches, a continuous increase of both quantitative and qualitative parameters was found. The combination with density-equalizing calculations demonstrated a leading position of the United States (2,959 items published) in terms of quantitative research activities. Charting techniques demonstrated that there are numerous bi- and multilateral networks between different countries and institutions in this field. Again, a leading position of American institutions was found. Conclusions This is the first comprehensive scientometric analysis of data on global scientific activities in the field of environmental tobacco smoke research. The present findings can be used as a benchmark for funding allocation processes.

Shift work and pathological conditions

Shift work exerts major influences on the physiological functions of the human body. These are primarily mediated by the disruption of circadian rhythms since most body functions are circadian rhythmic. Next to the disturbances caused by changes in the circadian system, shift work has also been suggested to be related to a number of other health disorders. The present study summarizes recently published data on the potential relationship between disorders and shift working.

Zur Wirksamkeit von Umweltzonen: Design einer Studie zur Ermittlung der Schadstoffkonzentrationsänderung für Staubpartikel (PM10) und andere Größen durch Einführung von Umweltzonen in 20 deutschen Städten

ZusammenfassungEs ist unbekannt bzw. umstritten, ob die in Deutschland seit 2008 eingeführten Umweltzonen die gemessene Luftbelastung verringerten. Von EUGT wurde daher eine Untersuchung initiiert, die zunächst für den Zeitraum bis Ende 2009 eine Analyse von Luftmessdaten zur Wirksamkeit der Umweltzonen durchführen soll und die a)alle Umweltzonen aus den bisherigen in Deutschland durchgeführten Studien berücksichtigt (Berlin, Bremen, Hannover, Köln, Ludwigsburg, Mannheim, München, Stuttgart, Tübingen)b)Luftmessdaten aus weiteren Umweltzonen einbezieht (Augsburg, Dortmund, Duisburg, Düsseldorf, Essen, Frankfurt, Herrenberg, Ilsfeld, Karlsruhe, Reutlingen, Wuppertal)c)die Auswertung adjustiert mit Referenzmesstellen auf Basis der Einzelmessungen und unter Berücksichtigung von Kovari-ablen durchführtd)neben einem multiplikativen Störungsansatz im Wesentlichen einen additiven Störeinfluss ansetzt. In dieser Untersuchung soll somit in einem ersten Schritt der Einfluss der Fahrverbote (Stufe 1) für Fahrzeuge der Schadstoffgruppe 1 (ohne Plakette) auf die Schadstoffkonzentration in ausgewählten Umweltzonen untersucht werden.Die zentrale Beobachtungseinheit besteht aus vier einander paarweise zugeordneten Messwerten: gematchte Quadrupel aus zwei Index- und zwei Referenzmesswerten. Die Indexstationen liegen innerhalb, Referenzstationen außerhalb der Umweltzonen. Ein Index- und der zeitgleiche Referenzmesswert liegen in der Beobachtungsphase mit aktiver Umweltzone, das andere zeitgleiche Paar liegt davor (Umweltzone nicht aktiv) und hat einen zeitlichen Abstand von 364 Tagen (oder Vielfachen von 364 Tagen, Wochentag und Uhrzeit konstant) zu dem ersten Paar.Für den Zeitraum von ca. 2005 bis 2009 sollen kontinuierliche Halbstundenmessungen zu PM10, undgravimetrisch ermittelte Tageswerte zu PM10 und PM2.5 in der Studie analysiert werden. Entsprechende Messwerte für NO2, NO, CO und O3 (testweise SO2) sowie 4-Wochen-Messwerte, gewonnen mit NO2-Passivsammlern, werden miterfasst, aber nicht primär augewertet. Als meteorologische Größen werden Temperatur, Luftfeuchte, Luftgeschwindigkeit und Windrichtung mitgeführt. Individuelle Charakteristika der Umweltzonen werden als Kovariablen in Regressionsanalysen der Quadrupel berücksichtigt (Differenzwertmethode im Zwei-Perioden-Fall).Die Studie wird von einem Projektbegleitkreis unter Beteiligung der kooperierenden Landeseinrichtungen begleitet. Ergebnisse werden bis Ende 2011 erwartet.AbstractWhether low emission zones as introduced in Germany since 2008 lower the measured concentrations of air pollutions is unknown or disputed. An investigation was started as a EUGT project that covers the period up to the end of 2009 and will perform an in-depth statistical analysis of air pollutant data. The study a)will cover low emission zones from all investigations published up to now (Berlin, Bremen, Hannover, Köln, Ludwigsburg, Mannheim, München, Stuttgart, Tübingen)b)will cover other low emission zones (Augsburg, Dortmund, Duisburg, Düsseldorf, Essen, Frankfurt, Herrenberg, Ilsfeld, Karlsruhe, Reutlingen, Wuppertal)c)will perform regression analyses on the basis of the individual measurement data taking covariates into accountd)will rely mainly on the assumption of an additive effect of confounders but will explore multiplicative models also. Thus, this investigation will study in a first step the effect of “tier 1”, i.e., only allowing vehicles of emission group 2 or higher (with “sticker”) to enter the zones.The central unit of observation will consist of four pairwise corresponding measurement values: matched quadrupels of two index- and two reference values. Index stations are inside, reference stations measure outside the low emission zones. One index value and the simultaneous reference value are measured during the period the zone is operative, the other pair is measured before activating the low emission zone. The pairs have a difference in time of 364 days or a multiple of 364 days keeping the weekday and time constant.For the period from about 2005 until 2009 continuous half-hour measurement values of PM10, gravimetrically determined daily measurements of PM10 and PM2.5 will be analysed. NO2, NO, CO und O3 (testing SO2), and additional measurements of NO2 with sampling periods of about 4 weeks will be collected, too. Data on dry temperature, humidity, wind speed and wind direction will be collected. Individual characteristics of the low emission zones will be taken into account as covariates in the regression analyses of the quadruples (difference score method in the two-period case).The study is monitored by an advisory group including representatives of all cooperating state institutions. Results are expected until the end of 2011.

Einrichtung einer Umweltzone und ihre Wirksamkeit auf die PM10-Feinstaubkonzentration — eine Pilotanalyse am Beispiel München

ZusammenfassungSeit Einführung der Umweltzonen in Deutschland im Jahr 2008 stellt sich die Frage nach ihrer Effizienz zur Feinstaubreduktion. In dieser Pilotstudie wurden Messdaten vor und nach Einführung der Umweltzone in München (Oktober 2007 bis Januar 2008 vs. Oktober 2008 bis Januar 2009) mithilfe gematchter Messwerte-Quadrupel analysiert. Basierend auf einer publizierten Methodik (Morfeld et al. 2011) wurden kontinuierliche Halbstundenmessungen von PM10-Staubkonzentrationen zeitgleich ermittelt an innerhalb der Umweltzone gelegenen Indexstationen und außerhalb positionierten Referenzstationen (Hintergrundbelastung). Diese jeweils gematchten Messwertequadrupel wurden vergleichend ausgewertet mit Hilfe der Differenzwertmethode im Zwei-Perioden-Fall. Zusätzlich wurden meteorologische Größen (Mischungsschichthöhe, Niederschlagsmenge, Luftgeschwindigkeit) sowie Basisdaten an Index- und Referenzstationen regressionstechnisch berücksichtigt. Die Auswertemethodik wurde mittels einer Analyse von Simulationsdaten vorab erfolgreich geprüft.Insgesamt konnten 26438 Quadrupel für den Auswertezeitraum zusammengestellt werden. Als PM10-Mittelwerte ergaben sich an 5 Indexstationen vor bzw. nach Einführung der Umweltzone 33.9 μg/m3 bzw. 39.0 μg/m3 und 24.6 μg/m3 bzw. 30.5 μg/m3 an einer Referenzstation außerhalb der Münchener Umweltzone. Ein additives Modell ermittelte unter Berücksichtigung von Kovariablen eine durchschnittliche PM10-Staubkonzentrationsänderung von +0.017 μg/m3 (0.95-CI: −0.33 μg/m3, +0.37 μg/m3), ein multiplikatives Modell schätzte den relativen Effekt durch die Einführung der Umweltzone auf −0.5 % (0.95-CI: −0.12 %, +0.30 %).Die mit diesem methodischen Auswerteansatz erzielten Ergebnisse unterscheiden sich relevant von den Befunden einer früheren Analyse auf der Basis derselben Messdaten der Münchner Umweltzone von Cyrys et al. (2009). Aufgrund der hier erzielten Ergebnisse lassen sich die Befunde von Cyrys et al. (2009) nicht als Beweis für eine Effektivität der Umweltzone heranziehen. Vielmehr ist der methodische Ansatz für eine wissenschaftlich belastbare Bewertung der Wirksamkeit von Umweltzonen entscheidend. Eine sorgfältige Datenauswahl und stringente Auswerteregeln müssen beachtet werden, um Fehlschlüsse hinsichtlich der PM10-Konzentrationsänderungen zu vermeiden.AbstractSince the introduction of low emission zones in Germany in 2008 the question of their efficiency has been debated. In this pilot study, measurement data collected before and after the introduction of the low emission zone in Munich (October 2007 until January 2008 vs. October 2008 until Januar 2009) were analysed on the basis of matched quadruples. Applying previously described methods (Morfeld et al. 2011), continuously measured half-hour fine dust concentration data (PM10) — simultaneously determined at an index station situated inside the low emission zone and a reference station outside of the zone — were contrasted and analysed (difference score method in the two-period case). Meteorological parameters (height of the inversion base, amount of precipitation, wind velocity) as well as baseline data of index and reference stations were taken into account as covariates in regression analyses. The statistical approach was successfully validated in an analysis of simulated data.26438 quadrupels could be matched for analysis. Averages of PM10 concentration values before (after) introducing the low emission zone were 33.9 μg/m3 (39.0 μg/m3) at 5 index stations and 24.6 μg/m3 (30.5 μg/m3) at 2 reference stations. Taking covariates into account, an additive model estimated the change in concentration associated to the introduction of the low emission zone as +0.017 μg/m3 (0.95-CI: −0.33 μg/m3, +0.37 μg/m3), multiplicative model estimated the relative effect as −0.5% (0.95-CI: −0.12%, +0.30%).The results of this study differ relevantly from the findings of an earlier investigation by Cyrys et al. (2009) who analyzed the same data. This analysis does not prove the effectiveness of Munich’s low emission zone. This study also points out that the methodological approach is crucial for a scientifically reliable evaluation of the efficacy of low emission zones. Strict rules need to be followed in order to prevent from misinterpretations.

Cruciate ligament: density-equalizing mapping and scientometrics as a measure of the current scientific evaluation

The topic “cruciate ligament” is of increasing interest due to improved diagnostic methods and the necessity to cure “modern” leisure time sports injuries. Publications have increased strongly since the 1990s. In this respect, it is difficult for a scientist to obtain an overview of a topic he/she is interested in. Scientometrics is a relatively new method to evaluate research efforts, to detect single areas of interest and to quantify the scientific impact of publications according to a particular topic. By comparing quantitative (i.e. number of published items) and qualitative factors (i.e. h-index, Impact-Factor or Citation rate), it is possible to evaluate this analysis methodically. In the period 1903–2007, a number of 9,806 published items were included in the ISI-Web referring to “cruciate ligament”. The publications were published by 59 countries demonstrating the USA, Germany and the UK as the most productive ones. The “American Journal of Sports Medicine” was determined to be the most prolific journal and “WOO, SLY” as the most prolific author dealing with “cruciate ligament”. The USA, Sweden, Finland and Norway take a leading position in citation per item rankings. In this respect, further analysis of the citations revealed the tendency of a disproportional high self-citation rate for some countries (e.g. Sweden, Finland). Self-citations lead to high average citations rates and distort further qualitative parameters (i.e. Impact-Factor, h-index). In this respect, the value of these parameters should be considered from a critical point of view. Furthermore, it might be useful to establish parameters which limit co-authorship and exclude self-citations to obtain more sustainable results.

Mobile air quality studies (MAQS) in inner cities: particulate matter PM10 levels related to different vehicle driving modes and integration of data into a geographical information program

BackgroundParticulate matter (PM) is assumed to exert a major burden on public health. Most studies that address levels of PM use stationary measure systems. By contrast, only few studies measure PM concentrations under mobile conditions to analyze individual exposure situations.MethodsBy combining spatial-temporal analysis with a novel vehicle-mounted sensor system, the present Mobile Air Quality Study (MAQS) aimed to analyse effects of different driving conditions in a convertible vehicle. PM10 was continuously monitored in a convertible car, driven with roof open, roof closed, but windows open, or windows closed.ResultsPM10 values inside the car were nearly always higher with open roof than with roof and windows closed, whereas no difference was seen with open or closed windows. During the day PM10 values varied with high values before noon, and occasional high median values or standard deviation values due to individual factors. Vehicle speed in itself did not influence the mean value of PM10; however, at traffic speed (10 – 50 km/h) the standard deviation was large. No systematic difference was seen between PM10 values in stationary and mobile cars, nor was any PM10 difference observed between driving within or outside an environmental (low emission) zone.ConclusionsThe present study has shown the feasibility of mobile PM analysis in vehicles. Individual exposure of the occupants varies depending on factors like time of day as well as ventilation of the car; other specific factors are clearly identifiably and may relate to specific PM10 sources. This system may be used to monitor individual exposure ranges and provide recommendations for preventive measurements. Although differences in PM10 levels were found under certain ventilation conditions, these differences are likely not of concern for the safety and health of passengers.

Bidirectional Assessment of Stress, job satisfaction and work ability of Educators in day care centres: a real-time observation study - the study protocol (BASE)

BackgroundOccupational demands of educators are not very well researched. Nevertheless their work is subject to several requirements. Whether these demands have an effect on the work ability and the health status of employees has also not been examined. Furthermore it is unclear if the ownership type of day care centres have an influence on job satisfaction and work ability of the pedagogical staff and what kind of resources do exist. Previous studies were mainly based on questionnaire data. Objective data does not exist. Therefore the aim of this investigation is to collect precise data relating to work of educators.MethodsEffects of different types of ownership of day care centres on job satisfaction and work ability of educators will be assessed with the help of objective real time studies in combination with multi-level psycho diagnostic measurements.DiscussionThe present study is the first of its kind. Up to now there are no computer-based real time studies on workflow of pedagogical staff with regard to assess their work-related stress. Following an exhaustive documentation of educators work processes the day-to-day task can be estimated and approaches for prevention can be developed. This can substantially contribute to an overall improvement of child care in Germany.

Giftschlangenbisse — eine globale Herausforderung

ZusammenfassungGiftschlangen kommen in vielen Regionen der Welt vor und haben zahlreiche Lebensräume erobert. Sie sind weltweit für etwa 2,5 Millionen Bisse und 100 000 Todesfälle verantwortlich. Die epidemiologische Erfassung der Unfälle mit Giftschlangen erfolgt in den meisten Ländern nur lückenhaft.Im Falle einer Vergiftung ist die Vielfalt an Symptomen komplex und keineswegs vorhersehbar. Die zur Verfügung stehenden Therapiemöglichkeiten sind begrenzt.Der vorliegende Übersichtsartikel befasst sich mit Giftschlangenbissen und der Wirkung von Schlangengift beim Menschen.SummaryVenomous snakes exist in many regions of the world and have conquered various habitats. About 2.5 Million humans suffer from snake bite accidents worldwide and approximately 100.000 of those bitten die. In most countries, the epidemiological registration of snake bite accidents is generally incomplete.In case of envenomation, symptoms are complex, may vary and are by no means predictable. Therapeutical options are limited.The current review explores the importance of venomous snake bites and action of snake venom in humans.

Introduction of a low-emission zone and the effect on air pollutant concentration of particulate matter (PM10) — a pilot study in Munich

ZusammenfassungSeit Einführung der Umweltzonen in Deutschland im Jahr 2008 stellt sich die Frage nach ihrer Effizienz zur Feinstaubreduktion. In dieser Pilotstudie wurden Messdaten vor und nach Einführung der Umweltzone in München (Oktober 2007 bis Januar 2008 vs. Oktober 2008 bis Januar 2009) mithilfe gematchter Messwerte-Quadrupel analysiert. Basierend auf einer publizierten Methodik (Morfeld et al. 2011) wurden kontinuierliche Halbstundenmessungen von PM10-Staubkonzentrationen zeitgleich ermittelt an innerhalb der Umweltzone gelegenen Indexstationen und außerhalb positionierten Referenzstationen (Hintergrundbelastung). Diese jeweils gematchten Messwertequadrupel wurden vergleichend ausgewertet mit Hilfe der Differenzwertmethode im Zwei-Perioden-Fall. Zusätzlich wurden meteorologische Größen (Mischungsschichthöhe, Niederschlagsmenge, Luftgeschwindigkeit) sowie Basisdaten an Index- und Referenzstationen regressionstechnisch berücksichtigt. Die Auswertemethodik wurde mittels einer Analyse von Simulationsdaten vorab erfolgreich geprüft.Insgesamt konnten 26438 Quadrupel für den Auswertezeitraum zusammengestellt werden. Als PM10-Mittelwerte ergaben sich an 5 Indexstationen vor bzw. nach Einführung der Umweltzone 33.9 μg/m3 bzw. 39.0 μg/m3 und 24.6 μg/m3 bzw. 30.5 μg/m3 an einer Referenzstation außerhalb der Münchener Umweltzone. Ein additives Modell ermittelte unter Berücksichtigung von Kovariablen eine durchschnittliche PM10-Staubkonzentrationsänderung von +0.017 μg/m3 (0.95-CI: −0.33 μg/m3, +0.37 μg/m3), ein multiplikatives Modell schätzte den relativen Effekt durch die Einführung der Umweltzone auf −0.5 % (0.95-CI: −0.12 %, +0.30 %).Die mit diesem methodischen Auswerteansatz erzielten Ergebnisse unterscheiden sich relevant von den Befunden einer früheren Analyse auf der Basis derselben Messdaten der Münchner Umweltzone von Cyrys et al. (2009). Aufgrund der hier erzielten Ergebnisse lassen sich die Befunde von Cyrys et al. (2009) nicht als Beweis für eine Effektivität der Umweltzone heranziehen. Vielmehr ist der methodische Ansatz für eine wissenschaftlich belastbare Bewertung der Wirksamkeit von Umweltzonen entscheidend. Eine sorgfältige Datenauswahl und stringente Auswerteregeln müssen beachtet werden, um Fehlschlüsse hinsichtlich der PM10-Konzentrationsänderungen zu vermeiden.AbstractSince the introduction of low emission zones in Germany in 2008 the question of their efficiency has been debated. In this pilot study, measurement data collected before and after the introduction of the low emission zone in Munich (October 2007 until January 2008 vs. October 2008 until Januar 2009) were analysed on the basis of matched quadruples. Applying previously described methods (Morfeld et al. 2011), continuously measured half-hour fine dust concentration data (PM10) — simultaneously determined at an index station situated inside the low emission zone and a reference station outside of the zone — were contrasted and analysed (difference score method in the two-period case). Meteorological parameters (height of the inversion base, amount of precipitation, wind velocity) as well as baseline data of index and reference stations were taken into account as covariates in regression analyses. The statistical approach was successfully validated in an analysis of simulated data.26438 quadrupels could be matched for analysis. Averages of PM10 concentration values before (after) introducing the low emission zone were 33.9 μg/m3 (39.0 μg/m3) at 5 index stations and 24.6 μg/m3 (30.5 μg/m3) at 2 reference stations. Taking covariates into account, an additive model estimated the change in concentration associated to the introduction of the low emission zone as +0.017 μg/m3 (0.95-CI: −0.33 μg/m3, +0.37 μg/m3), multiplicative model estimated the relative effect as −0.5% (0.95-CI: −0.12%, +0.30%).The results of this study differ relevantly from the findings of an earlier investigation by Cyrys et al. (2009) who analyzed the same data. This analysis does not prove the effectiveness of Munich’s low emission zone. This study also points out that the methodological approach is crucial for a scientifically reliable evaluation of the efficacy of low emission zones. Strict rules need to be followed in order to prevent from misinterpretations.