Differential Orientation of 10T1/2 Mesenchymal Cells on Non-Uniform Stretch Environments

Non-uniform stress and strain fields are prevalent in many tissues in vivo, and often exacerbated by disease or injury. These mechanical gradients potentially play a role in contributing to pathological conditions, presenting a need for experimental tools to allow investigation of cell behavior within non-uniformly stimulated environments. Herein, we employ two in vitro cell-stretching devices (one previously published; one newly presented) capable of subjecting cells to cyclic, non-uniform stretches upon the surface of either a circular elastomeric membrane or a cylindrical PDMS tube. After 24 hours of cyclic stretch, 10T1/2 cells on both devices showed marked changes in long-axis orientation, with tendencies to align parallel to the direction of minimal deformation. The degree of this response varied depending on location within the stretch gradients. These results demonstrated the feasibility of conducting cell mechanobiology investigations with the two novel devices, while also highlighting the experimental capabilities of non-uniform mechanical environments for these types of studies. Such capabilities include robust data collection for developing mechanobiological dose-response curves, signal threshold identification, and potential spatial targeting for drug delivery.     

Recent advances in the chemistry of certain blood constituents

Reviews of Physiology, Biochemistry and Pharmacology -     

Identification of the acrylate porphyrin S-411 from meconium

A new porphyrin isolated from calf and foal meconium has been characterized as a tris-(2-carboxyethyl)-mono-(2-carboxyvinyl)-tetramethyl porphin, that is as an analogue of coproporphyrin in which one propionate group has been replaced by an acrylate group. The porphyrin is mainly a type III isomer and its possible significance in haem biosynthesis is discussed.     

Discounting of delayed hypothetical money and food: effects of amount

Delay discounting research determines how the value of an outcome is affected by delay to its receipt. Research so far shows that consumable outcomes are discounted more steeply by delay than money. Prior studies, however, have used large amounts of the outcomes (e.g. 100 dollars worth) that would not typically be consumed in one bout, unlike the corresponding amount of money (e.g. 100 dollars ). This experiment examined whether small amounts of food would be discounted more steeply than money, as occurs with larger amounts. One hundred and two adults indicated their preferences in a series of choices for two hypothetical outcome types: immediate versus delayed food and immediate versus delayed money. Participants made choices involving either relatively small maximum amounts of food (10 dollars worth) and money (10 dollars) or for relatively large maximum amounts of food (100 dollars worth) and money (100 dollars ). In the within-subject comparisons, food was discounted more steeply by delay than money for both groups. In the between-subject comparisons, different amounts of the commodities were affected similarly by delay. Overall, these results suggest that steeper discounting of consumable outcomes than money is a fairly robust phenomenon, occurring with relatively small amounts of outcomes as well as with larger amounts.