Microfluidics platform for measurement of volume changes in immobilized intestinal enteroids

Intestinal enteroids are ex vivo primary cultured single-layer epithelial cell spheroids of average diameter ∼150 μm with luminal surface facing inward. Measurement of enteroid swelling in response to secretagogues has been applied to genetic testing in cystic fibrosis and evaluation of drug candidates for cystic fibrosis and secretory diarrheas. The current measurement method involves manual addition of drugs and solutions to enteroids embedded in a Matrigel matrix and estimation of volume changes from confocal images of fluorescently stained enteroids. We developed a microfluidics platform for efficient trapping and immobilization of enteroids for quantitative measurement of volume changes. Multiple enteroids are trapped in a “pinball machine-like” array of polydimethylsiloxane posts for measurement of volume changes in unlabeled enteroids by imaging of an extracellular, high-molecular weight fluorescent dye. Measurement accuracy was validated using slowly expanding air bubbles. The method was applied to measure swelling of mouse jejunal enteroids in response to an osmotic challenge and cholera toxin-induced chloride secretion. The microfluidics platform allows for parallel measurement of volume changes on multiple enteroids during continuous superfusion, without an immobilizing matrix, and for quantitative volume determination without chemical labeling or assumptions about enteroid shape changes during swelling.     

Individuelle und kontextuelle Prädiktoren des Fachwissenserwerbs zum Internen Rechnungswesen im Hochschulstudium

In our study, we examine some theoretically relevant personal factors as predictors of students’ acquisition of knowledge of management accounting, a key area of business and economics studies in higher education. We modeled and assessed business and economics students’ knowledge of management accounting in Germany using an internationally proven accounting test that has been translated and adapted and comprehensively validated for higher education in Germany. A review of the international literature showed that potential predictors might include not only learning opportunities students have used during and prior to higher education, but also students’ socio-cultural background and gender. These factors were assessed in a survey of 1012 students studying at 23 institutions of higher education. Not surprisingly, a multilevel analysis confirmed that among the learning opportunities a course in management accounting has the greatest effect on students’ knowledge of management accounting. But when other potential predictors are controlled, completion of a commercial vocation training prior to university studies shows a positive effect, as well.