the-use-ex-vivo-chandler-loop-apparatus-to-assess-biocompatibility

The Use of the <em>Ex Vivo</em> Chandler Loop Apparatus to Assess the Biocompatibility of Modified Polymeric Blood Conduits

The foreign body reaction occurs when a synthetic surface is introduced to the body. It is characterized by adsorption of blood proteins and the ...

using-gfp-tagged-tmem184a-construct-for-confirmation-heparin-receptor

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

When novel proteins are identified through affinity-based isolation and bioinformatics analysis, they are often largely uncharacterized. Antibodies ...

The Children's Hospital of Philadelphia

University of Pennsylvania Perelman School of Medicine

DeSales University

The prevalence of exercise-induced bronchoconstriction is reported to be high among recreational and elite athletes, yet diagnosis is often symptom-based. Indirect challenges such as the laboratory exercise challenge provide objective criteria for proper diagnosis and treatment. However, a standardized protocol using appropriate exercise intensity, duration, and dry air inhalation is often not implemented, and thus a false-negative test may result. This article reviews and describes the symptom-based diagnosis, the exercise challenge, and other indirect challenges such as eucapnic voluntary hyperpnea, hypertonic saline inhalation, and inhaled powdered mannitol as methods to diagnose and evaluate exercise-induced bronchoconstriction. Advantages and disadvantages of each diagnostic procedure are presented.

Exercise and other indirect challenges to demonstrate asthma or exercise-induced bronchoconstriction in athletes.

Vascular endothelial cells and their actin microfilaments align in the direction of fluid shear stress (FSS) in vitro and in vivo. To determine whether cofilin, an actin severing protein, is required in this process, the levels of phospho-cofilin (serine-3) were evaluated in cells exposed to FSS. Phospho-cofilin levels decreased in the cytoplasm and increased in the nucleus during FSS exposure. This was accompanied by increased nuclear staining for activated LIMK, a cofilin kinase. Blocking stress kinases JNK and p38, known to play roles in actin realignment during FSS, decreased cofilin phosphorylation under static conditions, and JNK inhibition also resulted in decreased phospho-cofilin during FSS exposure. Inhibition of dynamic changes in cofilin phosphorylation through cofilin mutants decreased correct actin realignment. The mutants also decreased barrier integrity as did inhibition of the stress kinases. These results identify the importance of cofilin in the process of actin alignment and the requirement for actin realignment in endothelial barrier integrity during FSS.

Actin realignment and cofilin regulation are essential for barrier integrity during shear stress.

Published data provide strong evidence that heparin treatment of proliferating vascular smooth muscle cells results in decreased signaling through the ERK pathway and decreases in cell proliferation. In addition, these changes have been shown to be mimicked by antibodies that block heparin binding to the cell surface. Here, we provide evidence that the activity of protein kinase G is required for these heparin effects. Specifically, a chemical inhibitor of protein kinase G, Rp-8-pCPT-cGMS, eliminates heparin and anti-heparin receptor antibody effects on bromodeoxyuridine incorporation into growth factor stimulated cells. In addition, protein kinase G inhibitors decrease heparin effects on ERK activity, phosphorylation of the transcription factor ELK-1, and heparin-induced MKP-1 synthesis. Although transient, the levels of cGMP increase in heparin treated cells. Finally, knock down of protein kinase G also significantly decreases heparin effects in growth factor activated vascular smooth muscle cells. Together, these data indicate that heparin effects on vascular smooth muscle cell proliferation depend, at least in part, on signaling through protein kinase G. © 2014 Wiley Periodicals, Inc.

Joshua B. Slee

Division of Cardiology,
Department of Pediatrics,
Division of Cardiology, Department of Pediatrics

The Children's Hospital of Philadelphia

The Use of the Ex Vivo Chandler Loop Apparatus to Assess the Biocompatibility of Modified Polymeric Blood Conduits

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

Joshua B. Slee

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Division of Cardiology,Department of Pediatrics,Division of Cardiology, Department of Pediatrics

The Children's Hospital of Philadelphia

The Use of the Ex Vivo Chandler Loop Apparatus to Assess the Biocompatibility of Modified Polymeric Blood Conduits

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

Division of Cardiology,
Department of Pediatrics,
Division of Cardiology, Department of Pediatrics