Effects of mycophenolate mofetil on key pattern of coronary restenosis: a cascade of in vitro and ex vivo models

BACKGROUND: Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid (MPA), is a rationally designed immunosuppressive drug. The current study investigates the effect of MMF on key pattern of restenosis in a cascade of in vitro and ex vivo models. METHODS: Part I of the study investigated in northern blot and cytoflow studies the effect of MMF (50, 100, 150, 200, 250, and 300 μg/mL) on TNF-α induced expression of intercellular adhesion molecule 1 (ICAM-1) in human coronary endothelial cells (HCAEC) and human coronary medial smooth muscle cells (HCMSMC). Part II of the study applied a human coronary 3D model of leukocyte attack, the 3DLA-model. HCAEC and HCMSMC were cultured on both sides of a polycarbonate filters, mimicking the internal elastic membrane. Leukocyte attack (LA) was carried out by adding human monocytes (MC) on the endothelial side. The effect of MMF (50 μg/mL) on adhesion and chemotaxis (0.5, 1, 2, 3, 4, 6, and 24 h after LA) and the effect on proliferation of co-cultured HCMSMC (24 h after LA) was studied. In part III of the study a porcine coronary organ culture model of restenosis (POC-model) was used. After ex vivo ballooning MMF (50 μg/mL) was added to the cultures for a period of 1, 2, 3, 4, 5, 6, and 7 days. The effect on reactive cell proliferation and neointimal thickening was studied at day 7 and day 28 after ballooning. RESULTS: Expression of ICAM-1 in northern blot and cytoflow studies was neither clearly inhibited nor stimulated after administration of MMF in the clinical relevant concentration of 50 μg/mL. In the 3DLA-model 50 μg/mL of MMF caused a significant antiproliferative effect (p < 0.001) in co-cultured HCMSMC but had no effect on MC-adhesion and MC-chemotaxis. In the ex vivo POC-model neighter reactive cell proliferation at day 7 nor neointimal hyperplasia at day 28 were significantly inhibited by MMF (50 μg/mL). CONCLUSION: Thus, the data demonstrate a significant antiproliferative effect of clinical relevant levels of MMF (50 μg/mL) in the 3DLA-model. The antiproliferative effect was a direct antiproliferative effect that was not triggered via reduced expression of ICAM-1 or via an inhibition of MC-adhesion and chemotaxis. Probably due to technical limitations (as e.g. the missing of perfusion) the antiproliferative effect of MMF (50 μg/mL) could not be reproduced in the coronary organ culture model. A cascade of focused in vitro and ex vivo models may help to gather informations on drug effects before large experimental studies are initiated

Nonsimilar solution of the laminar boundary layer in an oscillatory flow by an integral matrix method

The development of a numerical procedure for the treatment of nonsimilar, unsteady, laminar boundary layers is presented. The solution is obtained from the laminar, isothermal, incompressible boundary layer equations employing a modification of the integral matrix procedure of Bartlett and Kendall. Solutions of example problems are presented for steady Blasius and Howarth flows, and for oscillating Blasius flow. Agreement with the known classical results is satisfactory and establishes the general feasibility of the method. Core storage requirements of 130,000 bytes allow consideration of as many as 25 nodal points across the boundary layer, 50 time increments per oscillation cycle and 50 streamwise stations. Solution of oscillating Blasius flow considering 8 nodal points and 16 time increments requires 13.49 seconds for one streamwise station utilizing IBM 360/67 time sharing capabilities.http://www.archive.org/details/nonsimilarsoluti00gastLieutenant, United States NavyApproved for public release; distribution is unlimited

It Wasn't Me: External Error Attribution Dampens Efferent-Based Predictions but not Proprioceptive Changes in Hand Localization

Knowing ones limb location is crucial in order to produce efficient movements. When a movement error is experienced, people account for whether the source of the error is external or internal in nature. When the error is clearly not caused by oneself, it is intuitive to correct for these errors without updating internal models for movement or estimating the position of the effector. That is, there should be reduced or no reliance on implicit learning. However, merely inducing explicit adaptation does not affect measures of implicit learning. Here, we use different visual manipulations that make the external nature of the error clear, and test how these manipulations affect both motor behaviour and hand location estimates. We manipulate the extent of external error attribution in four ways, while participants learn to perform a 30-degree visuomotor rotation task: a Non-instructed control group that receives neither instructions nor different visual stimuli, an Instructed group that receives a counter strategy for dealing with the rotation, a Cursor Jump group that sees the cursor misalignment mid-reach on every training trial, and a Hand View group that sees both the misaligned cursor and their actual hand on every trial. Although an initial advantage in learning is seen for the Instructed group, performance across all groups are not different by the end of training, suggesting that any effects observed for changes in motor behaviour and hand localization are due to the manipulations. During reaches without visual feedback about the cursor location, participants are instructed to perform reaching movements, while either including or excluding any strategy they may have developed during adaptation training to counter for the visuomotor rotation. All groups show awareness of the nature of the perturbation except for the Non-instructed group. Implicit changes in motor behaviour, measured with reach aftereffects, persist for all groups but are greatly reduced for the Hand View group. For hand localization, participants either generate their own movement (allowing for hand localization with both afferent-based proprioceptive information and efferent-based predictions of sensory consequences) or a robot moves their hand (allowing for only proprioceptive information). We find that afferent-based changes in hand localization persists across all groups, but efferent-based changes are reduced for only the Hand View group. These results show that the brain incorporates source attribution for estimating the position of the effector during motor learning, and that proprioceptive recalibration during hand localization is an implicit process impervious to external error attribution