E-Learning in der medizinischen Ausbildung – Ein Vergleich der Medien Onlinekurs und PDF

Das Ziel der vorliegenden Arbeit war die Evaluation des k-MED Onlinekurses „Grundlagen der Magnetresonanz-Tomographie“ des Fachbereichs Radiologie der Philipps-Universität Marburg. Für die Hypothese, dass Onlinekurse mit Animationen und interaktiven Übungsaufgaben gleichwertigen Lernskripten ohne entsprechende Elemente überlegen sind, sollte ein Beleg gefunden werden. Die Onlinekurse wurden auf Basis des lizenzfreien Lern-Management-Systems ILIAS (k-MED) realisiert. Die kontrollierte, randomisierte und experimentelle Studie wurde in Form eines Kreuzversuches angelegt. Im Sommersemester 2007 wurden 131 Studierende des Grundlagenkurses der Radiologie in zwei Gruppen A (66 Probanden) und B (65 Probanden) eingeteilt. Zwei inhaltlich verschiedenen Onlinekursen wurden zwei gleichwertige PDF-Dokumente gegenübergestellt. Beide Medien wurden über eine Lernplattform zur Nutzung angeboten. Die Gruppe A erhielt den Onlinekurs „Grundlagen der Strahlendiagnostik“ und das PDF „Grundlagenkurs der Magnetresonanz-Tomographie“. Die Gruppe B erhielt den Onlinekurs Schlussfolgerung/Zusammenfassung 43 „Grundlagenkurs der Magnetresonanz-Tomographie“ und das PDF „Grundlagen der Strahlendiagnostik“. Damit standen jeder Gruppe beide Medien (Onlinekurs und Lernskript) zur Verfügung. Aufgrund der Teilergebnisse der Abschlussklausur konnte der Lernerfolg zu den jeweiligen Themen und Medien im Vergleich zwischen den beiden Gruppen bewertet werden. Zusätzlich gab es einen selbst erstellten Online-Fragebogen, der auf freiwilliger Basis beantwortet werden konnte. Als Anreiz für das Ausfüllen des Fragebogens wurde den Studierenden nach der kompletten Bearbeitung ein Punkt für die Abschlussklausur gutgeschrieben. Die Rücklaufquote der Umfrage lag bei 100%. Die Auswertung des Fragebogens ergab, dass die Studierenden mit 87% das Lernen mit Lernskripten in der Ausbildung als sinnvoll erachteten. Bei den Onlinekursen stimmten dem nur 77,1% zu. Die gleiche Tendenz zeigte sich bei der Frage, ob die Studierenden es begrüßen würden, wenn mehr Onlinekurse bzw. Lernskripte im Rahmen ihrer Ausbildung zur Verfügung gestellt werden würden. Dem stimmten bei den Lernskripten 84,7% zu, bei den Onlinekursen nur 61,1%. Weiterhin erachteten 80% die Ausdruckbarkeit von Lernmedien als wichtig. Den Vorzug bestimmter Computermedien gaben 26,7% der Befragten den Onlinekursen, 23,7% bevorzugten Lernskripte und 39,7% sprachen sich für beide Lernmedien gleichermaßen aus. Diese Zahlen wurden durch die häufigste Freitextantwort des Fragebogens bestätigt, in der die Studierenden für jede Lerneinheit auf der k-MEDPlattform ein gleichwertiges Lernskript als PDF forderten. Die technischen Voraussetzungen für die Umsetzung von Computer basiertem Lernen konnten laut Umfrage im Sommersemester 2007 als ausreichend erfüllt betrachtet werden. 96% der Studienteilnehmer verfügten über einen eigenen Internetanschluss. 92% hatten einen DSL- oder vergleichbar schnellen Zugang zum Internet. Überraschend waren die Ergebnisse zum Lernerfolg in Bezug auf die beiden elektronischen Medien. Zwischen den beiden Gruppen und damit zwischen den beiden Medien Onlinekurs und Lernskript als PDF konnte in Bezug auf den Lernerfolg kein statistisch signifikanter Unterschied festgestellt werden. Aufwändig erstellte Onlinekurse mit Texten, Bildern, Animationen und interaktiven Übungsaufgaben ergaben keinen signifikanten Vorteil in Bezug auf den Lernerfolg gegenüber den gleichwertigen Kursen als PDF-Dokument mit ausschließlich Texten, Bildern Zusammenfassung 44 und einfachen Übungsaufgaben. Die Hypothese, dass multimediale Onlinekurse gleichwertigen PDF-Dokumenten überlegen sind, konnte somit nicht bestätigt werden. Wenn aufwändige und damit teure Onlinekurse gegenüber einfacheren Lernskripten (z.B. zum Download als PDF angeboten) keine Vorteile in Bezug auf den Lernerfolg der Studierenden haben, stellt sich die Frage, inwiefern es sich weiterhin lohnt, in die Erstellung neuer Onlinekurse zu investieren. Lernskripte lassen sich u.a. bei Bedarf einfach ausdrucken, offline am Bildschirm bearbeiten, sie bieten eine umfangreiche Suchfunktion und die Möglichkeit Abschnitte zu markieren oder mit Notizen zu versehen. Hyperlinks und Lesezeichen sorgen für eine einfache und übersichtliche Navigation. Das Format unterstützt technische Hilfsmittel zur Barrierefreiheit bei z.B. Sehbehinderungen. PDF-Dokumente lassen sich einfach über kostenlose Programme erstellen und bearbeiten. Es ist ein plattformunabhängiges Online- und Offline-Format und kann somit auf allen gängigen Betriebssystemen über den kostenlosen Acrobat Reader von Adobe geöffnet und bearbeitet werden. Damit ist das Format neben Desktop Computern, Notebooks, Netbooks und E-Book-Readern auch für kompakte Computersysteme wie PDAs, Handhelds und Smartphones geeignet. Die vielen Möglichkeiten und die kostengünstige Erstellung machen aus dem weit verbreiteten, aber bislang für das E-Learning unterschätzten Format ein hochinteressantes Medium für zukünftige elektronische und mobile Lernprojekte. Die vermehrte Bereitstellung von Lernskripten als PDF wäre also nicht nur eine sinnvolle Maßnahme zur Steigerung der wirtschaftlichen Effizienz der elektronischen Lehre, sie böte zudem auch viele weitere Vorteile gegenüber den hierarchisch und linear aufgebauten multimedialen Onlinekursen der k-MED-Plattform

Alcohols as a Means to Inhibit the Formation of Precipitates in Blends of Biodiesel and Fossil Diesel Fuel

The European diesel fuel specification limits the biodiesel content to 7 %. It is, however, desirable to increase the amount of renewables in the transport sector; therefore blending with a higher biogenic fuel content is of interest. Blending of fuels can lead to chemical reactions between fuel components and may result in undesired products. In detail, aged biodiesel from unsaturated FAME and fossil diesel fuels can form oligomers and precipitations with a maximum in the range of B10 to B20. Precursors are oligomers that can be separated from the biodiesel or the blends in an amount of up to 20 %. These oligomers seem to have potency for chemical reactions with fuel components or the engine oil. To prevent tentative problems in the fuel filter, the injecting system and the combustion process itself, the formation of oligomers should be disabled in blends. Alcohols have been proven and tested to dis-solve precipitations in the fuel. However, flash point problems occur, in case the alcohols have too low boiling points. In our tests, some alcohols could be identified to reach the demands of the diesel fuel standard EN 590. As acceptable monovalent alcohols, the longer-chained alcohols 1-octanol, 3-methyl-1-butanol (isoamyl alcohol) and 2-hexyldecan-1-ol were found. The blends with these alcohols both showed acceptable flashpoints according to DIN EN 590 and could prevent the occurrence of precipi-tates when added in a rather low concentration of about 6 to 8 %. Additionally, engine tests were carried out to monitor regulated and non-regulated emissions. The emissions of selected blends (B10+6OctOH, B10+8IsoamylOH, B10+8HexdecOH) were analyzed by using a single cylinder test engine (Farymann Diesel 18W, TIER 4, agricultural 5-mode test). All of these blends showed less NOx emissions than the pure B10 blend without addition of alcohol. For the CO, HC and PM emissions, no remarkable changes could be found. In the case of non-regulated emis-sions, no relevant changes were observed in carbonyl and PAH emissions, relative to the B10 blend without addition of alcohol. In the result, some blends from biodiesel, diesel fuel and alcohols tend to be appropriate to suppress chemical reactions in the fuel and probably in the engine oil. Further research is necessary to explain the chemical interactions that are responsible for the formation of oligomers and their reaction products. Not only chemical but physical bonds can play important roles and are in the focus of current research

CAR T-cell therapy and critical care : A survival guide for medical emergency teams.

Chimeric antigen receptor (CAR) T‑cells are genetically engineered to give T‑cells the ability to attack specific cancer cells, and to improve outcome of patients with refractory/relapsed aggressive B‑cell malignancies. To date, several CAR T‑cell products are approved and additional products with similar indication or extended to other malignancies are currently being evaluated. Side effects of CAR T‑cell treatment are potentially severe or even life-threatening immune-related toxicities, specifically cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Consequently, medical emergency teams (MET) are increasingly involved in the assessment and management of CAR T‑cell recipients. This article describes the principles of CAR T‑cell therapy and summarizes the main complications and subsequent therapeutic interventions aiming to provide a survival guide for METs with a proposed management algorithm

Pulmonary Hypertension in Patients with Chronic Kidney Disease on Dialysis and without Dialysis: Results of the PEPPER-Study

Pulmonary hypertension (PH) is common in patients with dialysis-dependent chronic kidney disease and is an independent predictor of mortality. However, specific hemodynamics of the pulmonary circulation, changes induced by hemodialysis and characterization into pre- or postcapillary PH have not been evaluated in patients with chronic kidney disease. We assessed consecutive patients with end-stage chronic kidney disease in WHO FC≥II with dyspnea unexplained by other causes on hemodialysis (group 1, n = 31) or without dialysis (group 2, n = 31) using right heart catheterization (RHC). In group 1, RHC was performed before and after dialysis. In end-stage chronic kidney disease, prevalence of precapillary PH was 13% (4/31), and postcapillary PH was discovered in 65% (20/31). All four cases of precapillary PH were unmasked after dialysis. In group 2, two cases of precapillary PH were detected (6%), and postcapillary PH was diagnosed in 22 cases (71%). This is the first study examining a large cohort of patients with chronic kidney disease invasively by RHC for the prevalence of PH. The prevalence of precapillary PH was 13% in patients with end-stage kidney disease. That suggests careful screening for precapillary PH in this selected patient population. RHC should be performed after hemodialysis

Haematopoietic cell transplantation in Switzerland, changes and results over 20 years: a report from the Swiss Blood Stem Cell Transplantation Working Group for Blood and Marrow Transplantation registry 1997-2016.

In 1997, the Swiss Blood Stem Cell Transplantation Group (SBST) initiated a mandatory national registry for all haematopoietic stem cell transplants (HCTs) in Switzerland. As of 2016, after 20 years, information was available for 7899 patients who had received an HCT (2781 allogeneic [35%] and 5118 autologous [65%]). As some patients had more than one transplant the total number of transplants was 3067 allogeneic and 6448 autologous. We compared patient characteristics and outcome of the first decade (1997-2006) and second decade (2007-2016) of the registry. There were numerous changes over time. For allogeneic HCT, transplant rates, and therefore use of HCT technology, increased from 14 to 21.8 HCTs per 1 million inhabitants per year from the first to the second decade. Likewise autologous HCTs increased from 24.8 to 37.2 annually corrected for population growth. Allogeneic transplant recipients were older (38.4 vs 48.3 years) and more frequently had unrelated donors in the second decade. Similarly, age increased for recipients of autologous HCT (50.8 vs 56.4 years). Analysis of outcome showed that the probabilities of overall and progression-free survival were stable over time, in spite of the treatment of older and higher risk patients. In multivariate analysis, nonrelapse mortality decreased in recipients of allogeneic HCT (relative risk 0.68, 95% confidence interval 0.52-0.87) over the two decades. Improvement in adjusted nonrelapse mortality compensated for the fact that higher risk patients were treated in more recent years, resulting in similar overall survival. Five-year survival probabilities were 56% (53-59%) in the first and 54% (51-57%) in the second decade for allogeneic HCT, and 59% (57-61%) in the first and 61% (59-63%) in the second decade for autologous HCT. Detailed analyses of changes over time are presented. This study included all HCTs performed in Switzerland during the period of observation and the data are useful for quality assurance programmes, healthcare cost estimation and healthcare planning. Between 50 and 60% of patients were long-term survivors after both types of HCT, indicating growing populations of surviving patients requiring long-term care and observation

Absence of Susceptibility Vessel Sign in Patients With Malignancy-Related Acute Ischemic Stroke Treated With Mechanical Thrombectomy.

Background and Purpose Clots rich in platelets and fibrin retrieved from patients with acute ischemic stroke (AIS) have been shown to be independently associated with the absence of the susceptibility vessel sign (SVS) on MRI and active malignancy. This study analyzed the association of SVS and the presence of active malignancy in patients with AIS who underwent mechanical thrombectomy (MT). Methods This single-center, retrospective, and cross-sectional study included consecutive patients with AIS with admission MRI treated with MT between January 2010 and December 2018. SVS status was evaluated on susceptibility-weighted imaging. Adjusted odds ratios (aORs) were calculated to determine the association between absent SVS and the presence of active or occult malignancy. The performance of predictive models incorporating and excluding SVS status was compared using areas under the receiver operating characteristics curve (auROC). Results Of 577 patients with AIS with assessable SVS status, 40 (6.9%) had a documented active malignancy and 72 (12.5%) showed no SVS. The absence of SVS was associated with active malignancy (aOR 4.85, 95% CI 1.94-12.11) or occult malignancy (aOR 11.42, 95% CI 2.36-55.20). The auROC of predictive models, including demographics and common malignancy biomarkers, was higher but not significant (0.85 vs. 0.81, p = 0.07) when SVS status was included. Conclusion Absence of SVS on admission MRI of patients with AIS undergoing MT is associated with malignancy, regardless of whether known or occult. Therefore, the SVS might be helpful in detecting paraneoplastic coagulation disorders and occult malignancy in patients with AIS

RAS-pathway mutation patterns define epigenetic subclasses in juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is an aggressive myeloproliferative disorder of early childhood characterized by mutations activating RAS signaling. Established clinical and genetic markers fail to fully recapitulate the clinical and biological heterogeneity of this disease. Here we report DNA methylome analysis and mutation profiling of 167 JMML samples. We identify three JMML subgroups with unique molecular and clinical characteristics. The high methylation group (HM) is characterized by somatic PTPN11 mutations and poor clinical outcome. The low methylation group is enriched for somatic NRAS and CBL mutations, as well as for Noonan patients, and has a good prognosis. The intermediate methylation group (IM) shows enrichment for monosomy 7 and somatic KRAS mutations. Hypermethylation is associated with repressed chromatin, genes regulated by RAS signaling, frequent co-occurrence of RAS pathway mutations and upregulation of DNMT1 and DNMT3B, suggesting a link between activation of the DNA methylation machinery and mutational patterns in JMML

Intestinal B-cells license metabolic T-cell activation in NASH microbiota/antigen-independently and contribute to fibrosis by IgA-FcR signalling

BACKGROUND & AIMS The progression of nonalcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH diets (for example, choline-deficient high-fat diet, CD-HFD) or chow diet for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and μMT mice (containing B cells only in the gastrointestinal tract) were fed a CD-HFD, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with NAFL, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and scRNA-Seq analysis were performed in liver and gastrointestinal tissue for immune cells in mice and humans. RESULTS Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen-specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B-cells and showed a positive correlation between IgA levels and activated FcRγ+ hepatic myeloid cells as well extent of liver fibrosis. CONCLUSIONS Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for treating NASH. IMPACT AND IMPLICATIONS Nonalcoholic steatohepatitis (NASH) is a chronic inflammatory condition on the rise and can lead to hepatocellular carcinoma (HCC), the 3rd most common cause of cancer-related death worldwide. Currently, there is no effective treatment for this progressive disease that correlates with a marked risk of HCC mortality and carries a substantial healthcare burden. To date, among all the solid tumours, especially in HCC, the incidence and mortality rates are almost the same, making it crucial to find curative treatments for chronic diseases, such as NASH, which highly predispose to tumorigenesis. We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we could show that the absence of B cells prevented HCC development. B-cell intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets in combinatorial NASH therapies against inflammation and fibrosis