Optimization of a test setup for examining blood damage caused by high shear forces

If blood pumps are applied in the human body or extracorporeal, blood damage can be caused by shear forces that act on the blood during the delivery. For an accelerated development of blood pumps with help of simulations there is a need for reliable limit values for shear forces. To determine these limit values a shear force test setup was built at the Institute for Multiphase Processes. In the context of the presented master thesis the former test setup peripheral devices were evaluated, possible blood damage mechanisms were considered, blood analysis in different experiments to identify the blood damage caused by different elements were made and peripheral devices were replaced. At the same time the shear chamber was constructional reengineered in a project thesis [1]. We were able to show, that in former works the blood damage caused by test setup peripheral devices had heterodyned the results. Finally the test setup was rebuilt with the results and a test was made. Two findings of the thesis are a reduction of about 60% of the number of components in the blood-conveying tube system and an application of a new fluid seal.SFB-TR37 - Q2SFB-TR37 - B4EXC 62/

Inhibition of PI3K improves contractility in alpha1-adrenergically stimulated myocardium

Neue Studien haben demonstriert, dass Phosphoinositide 3-Kinasen (PI3K) eine grundsätzliche Rolle in der Regulierung myocardialer Kontraktilität spielen. Jedoch, auch wenn bekannt ist, dass es unter alpha1-adrenerger Stimulation zu einer PI3K Aktivierung kommt, ist der Einfluss der PI3K nach alpha1-adrenergen Stimulation auf den inotropen Effekt unklar. Isoliertes ventrikuläre Kaninchenherzmuskelzellen wurden mit dem PI3K Hemmstoff Wortmannin inkubiert (WM, 0.1 µ Mol/L)). Die Stimulation mit dem alpha1 Agonisten Phenylephrin (PE, 10 µ Mol/L) veranlasste eine signifikant stärkere Zunahme der Kontraktilität in WMbehandelten Herzmuskelzellen im Vergleich zur Kontrollgruppe. (Verkürzungsfraktion in % der Ruhezellänge: 6.14 +/-0.33 %; n=26 vs. 4.85 +/0.33 %; n=26, P <0.05). Außerdem verstärkte die WM-Inkubation bedeutsam die positive Inotrope-Wirkung von PE in intakten Muskelstreifen aus Kaninchen-Herzen. Mechanistisch konnte gezeigt werden, dass in WM-inkubierten Kerzmuskelzellen PE die Phospholamban (PLN) Phosphorylierung und die intrazelluläre Ca2 + Konzentration im Vergleich mit den Kontrollezellen signifikant verstärkt. Zusammengefasst konnte diese Studie erstmalig zeigen, dass es durch Hemmung der PI3K, durch einen Anstieg der PLN Phosphorylierung und der Ca2 + Konzentration, zu einem signifikanten Anstieg der Kontraktilität in alpha1-adrenerg stimuliertem Kaninchenmyokard kommt. Diese Erkenntnis könnte von klinischer Relevanz in der Therapie der Herzinsuffizienztherapie sein

Lehmspritzverfahren Dokumentation und Auswertung einer innovativen Lehmbautechnik am Beispiel der Sanierung und Modernisierung von Gebaeuden

SIGLEAvailable from TIB Hannover: RO 5830(23) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekMinisterium fuer Bauen und Wohnen des Landes Nordrhein-Westfalen, Duesseldorf (Germany)DEGerman

A novel CD44 antibody identifies an epitope that is aberrantly expressed on acute lymphoblastic leukaemia cells

Previous studies have shown that the antibody 7H9D6 identifies CD44, a glycoprotein receptor for hyaluronic acid. 7H9D6 recognizes an epitope of CD44 that is not always present on CD44 molecules. The 7H9D6 antibody bound to the hyaluronic acid binding domain of CD44 and inhibited cell adhesion to immobilized hyaluronic acid. However, the expression of the 7H9D6 epitope was not sufficient for hyaluronic acid binding. Immunofluorescent staining with 7H9D6 revealed a punctate surface staining pattern, suggesting that CD44 molecules recognized by 7H9D6 are located in clusters on the cell surface. In contrast, other CD44 antibodies produced a uniform staining pattern. Early bone marrow B cells were negative for 7H9D6 but reactive with other CD44 monoclonal antibodies. In contrast, leukaemic cells from 65% of patients (28 of 43) with B lineage acute lymphoblastic leukaemia bound 7H9D6. Patients expressing the 7H9D6 epitope on their leukaemic cells had an increased risk of death (HR 3.5 95% CI 1.1-10.9, P = 0.029) and of disease relapse (HR 3.2 95% CI 1.2-8.5, P = 0.017) when corrected for white cell count. This antibody may be useful for the detection of residual disease in B lineage acute lymphoblastic leukaemia and as a prognostic indicator and for the study of CD44 function.Linda J Bendall ; Alexander James ; Andrew Zannettino ; Paul J Simmons ; David J Gottlieb ; Kenneth F Bradstoc