Assessing energy metabolism in the ischemic rat heart with hyperpolarized 13C pyruvate

This position paper argues that deep collaboration must be a part of any humanities visualization project and it investigates the nature and the place of such collaboration. I re-introduce the term "previsualization” to refer to the interdisciplinary, transmedial critical work that underlies the design and implementation of, as well as the critical reflection on, visualization. I argue for seeing previsualization more than just in its temporal sense of a “first step” of building visual systems, but as a necessary process of digital humanities modelling that contributes to critical linkages between visualization and the humanities research tradition. Finally, I discuss the tension inherent in visual systems between their specificity and generalizability and the need to remain critical as they grow

The formulation of hyperpolarized 13C pyruvate solutions influences the labeling of myocardial metabolites in vivo

In developing an intact rat model for myocardial ischemia using hyperpolarized 13C pyruvate, different compound formulations were evaluated. Infusion of 4-hydroxy-TEMPO-polarized sodium [1-13C]pyruvate was compared to an equivalent dose of buffered trityl radical-polarized [1-13C]pyruvic acid. Whereas higher levels of polarization and MRS signal were obtained with trityl radical, the metabolite signals normalized to total signal were lower. In particular, [1-13C]lactate signal relative to total signal was markedly higher using TEMPO-polarized pyruvate. [13C]bicarbonate and [1-13C]alanine signals were affected to a lesser degree. This study demonstrates the composition of the infused hyperpolarized pyruvate solution can significantly affect its metabolism in vivo