133 research outputs found

    Research governance in placebo-controlled trials: Is the EMA/ICH position consistent in itself and in accordance with the declaration of helsinki?

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    The European Medicines Agency and the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use are powerful international institutions for the regulation of biomedical research. Although not directly concerned with the ethical aspects of research, both institutions have disseminated position papers on ethical issues relating to the use of placebos in clinical trials. What appears initially to be guidance on the methodology of placebo-controlled trials (with very technical content) clearly has some far-reaching implications for the extent of risk patients can be expected to be subjected to in such trials. On the basis of this guidance, this article questions how much additional harm to patients would be acceptable in placebo-controlled trials in comparison with active-control trials. The article will show that the instruments provided in the guidance are unsuitable, remaining unclear on vital points and thereby leaving patients, researchers and research ethics committees without appropriate direction. In conclusion, placebo-controlled trials urgently need more. © The Author(s) 2014

    Der Einfluss obstruktiver Schlafapnoe und kontinuierlicher positiver Atemwegsdruck-Therapie auf das nasale Mikrobiom

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    Hintergrund und Ziele: Die obstruktive Schlafapnoe (OSA) ist eine hĂ€ufige schlafbezogene Atmungsstörung (1-3) und ein wichtiger kardiovaskulĂ€rer Risikofaktor (4-7). Der Goldstandard fĂŒr die Diagnose der OSA ist die Polysomnographie. Die wichtigste Therapieoption ist die kontinuierliche positive Atemwegsdruck-Therapie (CPAP-Therapie), bei welcher durch kontinuierlichen Überdruck die oberen Atemwege offengehalten werden (8). Da es nur durch eine dauerhafte Nutzung der CPAP-Therapie zu einer langfristigen Besserung kommt, ist eine hohe TherapieadhĂ€renz (Compliance) erforderlich (9). Jedoch fĂŒhrt unter anderem die wĂ€hrend der Therapie auftretende rhinitische Beschwerdesymptomatik mit Reizung der nasalen Schleimhaut hĂ€ufig zu TherapieabbrĂŒchen (10). Auch eine Dysbiose des nasalen Mikrobioms kann eine Reizung der Schleimhaut mit lokaler EntzĂŒndung und Ödem begĂŒnstigen. Das Ziel der Studie liegt darin, einen möglichen Zusammenhang zwischen obstruktiver Schlafapnoe und nasalem Mikrobiom zu erfassen sowie im Weiteren zu untersuchen, ob eine VerĂ€nderung des Mikrobioms unter einer CPAP-Therapie auftritt. Methoden: Im Zeitraum von August 2017 bis April 2018 wurden an der Klinik fĂŒr Hals-Nasen- Ohrenheilkunde, Kopf- und Halschirurgie des UniversitĂ€tsklinikum Erlangen insgesamt 39 Patienten in die Studie eingeschlossen. In der ersten Gruppe befanden sich 22 Patienten (n = 22) mit erstmalig polysomnographisch gesicherter OSA ohne bisherige CPAP-Therapie (Einschlusskriterium). Die Patienten dieser Gruppe wurden entsprechend des Schweregrades der obstruktiven Schlafapnoe nach gĂŒltigen Kriterien der American Academy of Sleep Medicine (AASM) in jeweilige Untergruppen (mittelgradige und schwergradige OSA) eingeteilt (11). In der Kontrollgruppe befanden sich 17 gesunde Probanden (n = 17), die bisher eine unauffĂ€llige Schlafgeschichte sowie keine Symptome einer akuten oder chronischen Rhinosinusitis aufwiesen (Einschlusskriterien). Als Ausschlusskriterien fĂŒr die Studienteilnahme galten eine zentrale oder gemischte Schlafapnoe, ein Alter 90 Jahre sowie vorherige chirurgische oder anderweitige Behandlungen an den oberen Atemwegen, welche aufgrund von OSA durchgefĂŒhrt wurden. Ebenfalls ausgeschlossen wurden Patienten mit akuten oder chronischen Erkrankungen, die eine eingeschrĂ€nkte Studienteilnahme zur Folge gehabt hĂ€tten, Patienten mit psychischen BeeintrĂ€chtigungen und Schwangere. In der Kontrollgruppe und in der OSA-Gruppe (vor Beginn einer CPAP-Therapie) wurden Abstriche zur Beurteilung des nasalen Mikrobioms und dessen Zusammensetzung im Bereich der Riechschleimhaut entnommen. In der OSA-Gruppe wurden zusĂ€tzlich im Verlauf nach 3 bis 6 sowie 6 bis 9 Monaten unter CPAP-Therapie Abstriche entnommen. Die Abstrichtupfer enthielten einen DNA-Stabilisator, sodass die DNA nach entsprechender Lagerung im Verlauf extrahiert, mittels Polymerasekettenreaktion (PCR) vervielfĂ€ltigt und sequenziert werden konnte. Anschließend erfolgte die Auswertung mithilfe des Online Tools „Microbiomeanalyst“ und SPSS. MessgrĂ¶ĂŸen waren dabei die absolute und relative Bakterienlast, die Quantifizierung der Bakterienfamilien sowie die Artenvielfalt (BiodiversitĂ€t) des nasalen Mikrobioms. Ergebnisse und Beobachtungen: Im Vergleich der OSA-Gruppe mit der Kontrollgruppe konnten kein signifikanter Unterschied bezĂŒglich der absoluten Bakterienlast sowie der BiodiversitĂ€t (α-DiversitĂ€t und ÎČ-DiversitĂ€t) beobachtet werden. Bei der Analyse der Untergruppen jedoch wiesen Patienten mit schwergradiger OSA im Vergleich zur Kontrollgruppe einen erhöhte α-DiversitĂ€t auf, wohingegen das nasale Mikrobiom von Patienten mit mittelgradiger OSA eine geringere α- DiversitĂ€t zeigte. Insgesamt waren die am hĂ€ufigsten vorkommenden Bakterienfamilien in allen Gruppen Corynebacteriaceae, Carnobacteriaceae und Staphylococceae. Im weiteren Vergleich mittels linearer Diskriminanzanalyse (LDA) zeigte sich im nasalen Mikrobiom der OSA-Gruppe ein signifikant höheres Vorkommen der Bakterienfamilie Xanthoerbacteraceae (p = 0,011) im Vergleich zur Kontrollgruppe. In der Kontrollgruppe wiederum traten die Bakterienfamilien Brucellaceae (p = 0,006), Burkholderiales incertae sedis (p = 0,002) und Eryspelothrichaceae (p = 0,021) signifikant hĂ€ufiger auf. Bei den OSA-Patienten mit CPAP- Therapie zeigte sich im longitudinalen Vergleich sowohl nach 3 bis 6 Monaten als auch nach 6 bis 9 Monaten kein signifikanter Unterschied in der α-DiversitĂ€t (p = 0,116) und ÎČ-DiversitĂ€t (p = 0,971). In der Analyse der Untergruppen zeigten die Proben von Patienten mit mittelgradiger OSA (im Gegensatz zu Patienten mit schwergradiger OSA) eine statistisch signifikante Zunahme der α-DiversitĂ€t nach 3 bis 6 Monaten (p = 0,018), wĂ€hrend nach 6 bis 9 Monaten keine weiteren VerĂ€nderungen festgestellt wurden. Ferner nahm die Anzahl der Bakterien, fĂŒr die in der linearen Diskriminanzanalyse ein signifikanter Unterschied zwischen moderater und schwerer OSA gefunden wurde, wĂ€hrend der CPAP-Behandlung ab. Schlussfolgerungen: Zusammenfassend zeigte sich ein Anstieg der BiodiversitĂ€t und eine Angleichung der Zusammensetzung des nasalen Mikrobioms von OSA-Patienten unter der CPAP-Therapie. Die eben genannten beobachteten Effekte können als Teil des therapeutischen Effekts oder auch als begĂŒnstigender Faktor der unerwĂŒnschten Nebenwirkungen der CPAP-Therapie gewertet werden. Wie bereits beschrieben kommt es unter CPAP-Therapie hĂ€ufig zu TherapieabbrĂŒchen aufgrund auftretender Nebenwirkungen wie unter anderem einer rhinitischen Beschwerdesymptomatik und darauffolgender mangelnder Compliance. Das Ziel weiterfĂŒhrender Untersuchungen sollte sein, ob durch die Modifikation des Mikrobioms, beispielsweise durch eine Probiotika-Therapie oder eine Mikrobiota- Transplantation, die Verbesserung der CPAP-Compliance erreicht werden kann

    Increased serum levels of procollagen type III peptide in severely injured patients

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    Objectives: To determine the serum concentrations of procollagen type in peptide in severely injured patients with different outcomes and to evaluate the relationship between serum procollagen type III peptide concentrations, sources of increased posttraumatic fibrotic activity (wounds, lung, liver, kidney), and decreased elimination of procollagen type III peptide (liver). Design: Prospective study. Setting: Surgical ICU, university hospital. Patients: Fifty-seven patients (mean injury severity score: 38.5 points, range 13 to 75 points), between 16 and 70 yrs of age, treated in our institution within 6 hrs after the accident. Measurements: Serial measurements were started on admission and continued on a 6-hr basis. After 48 hrs, the monitoring interval was extended to 24 hrs until recovery (but at least until day 14) or death. At each point of evaluation, pulmonary and circulatory function parameters and chest radiographs (once a day) were evaluated, the results were recorded, and blood samples were drawn to determine procollagen type III peptide, total bilirubin, creatinine, [gamma]-glutamyl transferase, polymorphonuclear elastase, and other parameters. Statistic evaluation was done with the Wilcoxon test, Spearman rank correlation, and a multiple regression model. Results: Mean procollagen type m peptide serum concentrations (+/- sd) were significantly different in patients who died (8.0 +/- 3.8 U/mL) compared with those patients who survived with organ failure (2.7 +/- 1.3 U/mL) or without complications (1.4 +/- 0.5 U/mL), respectively. Significant correlations of procollagen type HI peptide concentrations with the serum bilirubin concentrations (r = .7), days with need of mechanical ventilation (r = .64), Pao2/Fio2 ratio (r = -.6), polymorphonuclear elastase (r = .6), serum creatinine concentrations (r = .55), and injury severity score (r = .33) were observed. There was a tendency toward higher serum procollagen type III peptide concentrations in patients with severe skeletal injuries. Conclusions: Serum procollagen type III peptide concentrations in severely injured patients may be considerably increased in correlation with injury severity and outcome. Procollagen type III peptide serum concentrations seem to reflect the sum of increased collagen formation from wound healing and fibrogenesis of mediator-related organ damage (especially lung) and decreased procollagen type HI peptide excretion due to impaired liver function. Further data are necessary to evaluate the role of hepatic elimination in these patients

    The Virtual Tutor: Tasks for conversational agents in Online Collaborative Learning Environments

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    Online collaborative learning environments are becoming increasingly popular in higher education. E-tutors need to supervise, guide students and look out for conflicts within the online environment to ensure a successful learning experience. Web-based platforms allow for interactive elements such as conversational agents to disencumber the e-tutor. Repeatable tasks, which do not require a human response, can be automatized by these systems. The aim of this study is to identify and synthesize the tasks an e-tutor has and to investigate the automatisation potential with conversational agents. Using a design science research approach a literature review is conducted, identifying 13 tasks. Subsequently, a matrix is established, contrasting the tasks with requirements for the use of conversational agents. Furthermore, a virtual tutor framework is developed, clarifying the agent type selection, the technical structure and components for a prototype development in an online collaborative learning environment

    Off-label, off-limits? Parental awareness and attitudes towards off-label use in paediatrics

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    Off-label drug use in paediatrics is associated with an increased risk of adverse drug reactions. Any risk–benefit analysis has to be based on value judgments that should include parents' views. However, nothing is known so far about the parents' perspective on this critical issue. Therefore, a quantitative survey with parents of healthy and chronically ill children was carried out (n = 94). Knowledge about the practise of off-label use is generally poor in both groups. Surprisingly, this is also true for the parents of children with chronic disease. Nine percent of the parents of chronically ill children and 20% of the parents of healthy children would refuse treatment with an off-label drug. Parents who have poor knowledge about the practise of off-label use tend to refuse to volunteer their child for study participation. Therefore, the information of parents on the off-label use of drugs is important to meet ethical standards and to increase the parents' acceptance of medical studies with children

    White top-emitting organic light-emitting diodes with solution-processed nano-particle scattering layers

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    The authors are grateful to Novaled GmbH (Dresden) for financial support and material supply. M. C. Gather acknowledges financial support from the Scottish Founding Council through SUPA.A random scattering approach to enhance light extraction in white top-emitting organic light-emitting diodes (OLEDs) is reported. Through solution processing from fluorinated solvents, a nano-particlescattering layer (NPSL) can be deposited directly on top of small molecule OLEDs without affecting their electrical performance. The scattering length for light inside the NPSL is determined from transmission measurements and found to be in agreement with Mie scattering theory. Furthermore, the dependence of the light outcoupling enhancement on electron transport layer thickness is studied. Depending on the electron transport layer thickness, the NPSL enhances the external quantum efficiency of the investigated white OLEDs by between 1.5 and 2.3-fold. For a device structure that has been optimized prior to application of the NPSL, the maximum external quantum efficiency is improved from 4.7% to 7.4% (1.6-fold improvement). In addition, the scattering layer strongly reduces the undesired shift in emission color with viewing angle.Publisher PDFPeer reviewe

    Inflammatory mediators, infection, sepsis, and multiorgan failure after severe trauma

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    The relation of (multiple) organ failure (OF) to the release of inflammatory mediators and the incidence of infection and sepsis was studied prospectively in 100 patients with multiple trauma (injury severity score=37). Sixteen patients died of OF, 47 patients survived OF, and 37 patients had no OF. Fifteen (24%) of the patients with OF showed no signs of infection. In patients with early onset of OF (n=45), infection followed with a lag of 2 or more days. In 16 (44%) of these patients, infection led to a deterioration in organ function. With late onset of OF (n=18), infection preceded OF in nine patients. Polymorphonuclear leukocyte—elastase, neopterin, C-reactive protein, lactate, antithrombin III, and phospholipase A discriminated significantly among the three outcome groups. Of all factors, only polymorphonuclear leukocyte—elastase showed a difference between patients with and without infection or sepsis, respectively. These data indicate that infection might not play a crucial role in the pathogenesis of posttraumatic OF in a substantial portion of patients with trauma. Early OF, especially, seems to be mainly influenced by the direct sequelae of tissue damage and shock (eg, the release of inflammatory mediators). Since infection and sepsis did not lead to an augmented release of mediators in patients with trauma, the role of both entities remains unclear

    Orientation of OLED emitter molecules revealed by XRD

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    We thank Dr. Lutz Wilde at Fraunhofer IPMS, Center Nanoelectronic Technologies, Dresden for carrying out the GIXRD measurements. CM acknowledges funding by the Graduate Academy of the TU Dresden and by the European Commission through a Marie SkƂodowska Curie individual fellowship (703387).Thin films of the phosphorescent emitters Ir(ppy)3 and Ir(ppy)2(acac) are investigated by GIXRD and GIWAXS. Both molecules form crystalline grains and exhibit a preferred orientation that is pertained even when doped into a host.Postprin

    KonditionalitĂ€t in der gemeinsamen europĂ€ischen Schuldenaufnahme: NGEU: Vorbild fĂŒr ein verstetigtes Instrument?

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    Über das Next Generation EU Programm ist eine gemeinsame Schuldenaufnahme unter dem Dach der EU-KOMMISSION erstmals in großem Umfang ermöglicht worden. Auch wenn stets betont worden ist, dass NGEU eine Maßnahme einmaliger Natur ist, so beschreiben einige EU-AmtstrĂ€ger:innen, wie etwa der EU-Kommissar fĂŒr Wirtschaft, PAOLO GENTILONI, sowie EMMANUEL MACRON und MARIO DRAGHI, welche fiskalischen Möglichkeiten die Verstetigung eines solchen Programms bieten könnte. Der Beitrag untersucht daher, welche Bedingungen mit der gemeinsamen Schuldenaufnahme verbunden sind und ob diese KonditionalitĂ€t fĂŒr eine kĂŒnftige Schuldenaufnahme aus fiskalpolitischer Sicht adĂ€quat ist. Daraus sollen Bedingungen abgeleitet werden, die bei einer kĂŒnftigen gemeinsamen Schuldenaufnahme zu beachten sind.Through the Next Generation EU Program, joint borrowing under the umbrella of the EU Commission has been made possible on a large scale for the first time. Although it has always been stressed that NGEU is a one-off measure, some EU officials, such as EU Commissioner for Economic Affairs PAOLO GENTILONI, as well as EMMANUEL MACRON and MARIO DRAGHI, describe the fiscal opportunities that the continuation of such a program could offer. The paper therefore examines the conditions associated with joint debt borrowing and whether this conditionality is adequate for future debt borrowing from a fiscal policy perspective. From this, the paper aims to derive conditions that need to be observed for future joint debt borrowing

    High-performance organic light-emitting diodes comprising ultrastable glass layers

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    Organic light-emitting diodes with ultrastable glass emission layers show increased efficiency and device stability. Organic light-emitting diodes (OLEDs) are one of the key solid-state light sources for various applications including small and large displays, automotive lighting, solid-state lighting, and signage. For any given commercial application, OLEDs need to perform at their best, which is judged by their device efficiency and operational stability. We present OLEDs that comprise functional layers fabricated as ultrastable glasses, which represent the thermodynamically most favorable and, thus, stable molecular conformation achievable nowadays in disordered solids. For both external quantum efficiencies and LT lifetimes, OLEDs with four different phosphorescent emitters show >15% enhancements over their respective reference devices. The only difference to the latter is the growth condition used for ultrastable glass layers that is optimal at about 85% of the materials' glass transition temperature. These improvements are achieved through neither material refinements nor device architecture optimization, suggesting a general applicability of this concept to maximize the OLED performance, no matter which specific materials are used
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