It was reported previously that zinc-deficient mice show impaired lymphopoiesis. At the same time, monocyte numbers in these animals are increased, indicating a negative impact of zinc on monocyte development. Here, we investigate the role of zinc homeostasis in the differentiation of myeloid precursors into monocytes. Reduced gene expression of several zinc transporters, predominantly from the Zip family, was observed during 1 alpha, 25-dihydroxyvitamin D(3) (1,25D(3))-induced differentiation of HL-60 cells. This was accompanied by a reduction of intracellular-free zinc, measured by FluoZin-3. Amplifying this reduction with the zinc chelator TPEN or zinc-depleted cell-culture medium enhanced 1,25D(3)-induced expression of monocytic surface markers CD11b and CD14 on HL-60, THP-1, and NB4 cells. In contrast, differentiation of NB4 cells to granulocytes was not zinc-sensitive, pointing toward a specific effect of zinc on monocyte differentiation. Further, monocyte functions, such as TNF-alpha secretion, phagocytosis, and oxidative burst, were also augmented by differentiation in the presence of TPEN. The second messenger cAMP promotes monocyte differentiation. We could show that zinc inhibits the cAMP-synthesizing enzyme adenylate cyclase, and chelation of zinc by TPEN increases cAMP generation after stimulation with the adenylate cyclase activator forskolin. Based on our in vitro results and the in vivo observations from the literature, we suggest a model in which the intracellular-free zinc concentration limits AC activity, and the decrease of zinc after 1,25D(3) treatment promotes differentiation by relieving AC inhibition. Thus, cellular zinc homeostasis acts as an endogenous modulator of monocyte differentiation.

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Aim Because the field of information systems (IS) research is vast and diverse, structuring it is a necessary precondition for any further analysis of artefacts. To structure research fields, taxonomies are a useful tool. Approaches aiming to develop sound taxonomies exist, but they do not focus on empirical development. We aimed to close this gap by providing the CAFE methodology, which is based on quantitative content analysis. Subject and methods Existing taxonomies are used to build a coding scheme, which is then validated on an IS project database. After describing the methodology, it is applied to develop a telemedicine taxonomy. Results The CAFE methodology consists of four steps, including applicable methods. It helps in producing quantitative data for statistical analysis to empirically ground any newly developed taxonomy. By applying the methodology, a taxonomy for telemedicine is presented, including, e.g. application types, settings or the technology involved in telemedicine initiatives. Conclusion Taxonomies can serve in identifying both components and outcomes to analyse. As such, our empirically sound methodology for deriving those is a contribution not only to evaluation research but also to the development of future successful telemedicine or other digital applications.

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For more than 150 years, shake flasks are used in research and development as reaction chambers for chemical and microbiological reactions. An uncountable number of experiments has been performed in shake flasks—a suitable tool for laboratory scale—and, therefore, a lot of data and knowledge was achieved. Owing to its simple but advantageous design, the shake—also called Erlenmeyer—flask represents an appropriate tool for cultivation of biomass in biotechnological laboratories. Recently, more engineering efforts have been performed to describe conditions in shake flasks such as gas transfer or power consumption. Further innovative approaches were developed to either enable larger shaking systems for production or monitor growth‐related parameters online, and at line. Moreover, disadvantages of this technology such as less regulation and controlling possibilities or limitations in gassing/degassing have to be taken into account. The focus of this article is to give fundamental information about the most important issues in shake flask technology for biotechnological applications. Starting with a short historical introduction, the authors highlight the most commonly used types of different flask and closure types, volumes, etc. Subsequently, functions and the introduction of important shaking‐related parameters such as shaking diameter and shaking frequency are given. Before ending up with the innovative potential of modern investigations concerning this significant technology, advantages and disadvantages of shake flask applications are discussed.