Biorheology - Volume 46, issue 1

Authors: Meiselman, Herbert J.

Article Type: Research Article

Keywords: Red cell, aggregation, depletion model, aggregability, Poiseuille

DOI: 10.3233/BIR-2009-0522

Citation: Biorheology, vol. 46, no. 1, pp. 1-19, 2009

Authors: Zeng, Wen | Li, Li | Yuan, Wei | Wei, Yong | Mi, Jianhong | Sun, Jiansen | Wen, Can | Zhang, Wei | Ying, Dajun | Zhu, Chuhong

Article Type: Research Article

Abstract: Objective: To determine if A20, a zinc finger protein that mediates the inflammatory response, affects monocyte-endothelial cell–cell interactions induced by low shear flow. Methods: Primary cultured endothelial cells (EC) were transfected with an A20 expression vector, and the VCAM-1, ICAM-1 and IL-8 mRNA, and protein expression levels in A20-transfected EC lysates were checked by PCR array and ELISA, respectively. CD14-positive monocyte migration toward and adhesion to EC were measured using a parallel plate flow chamber. Results: Low shear stress, defined as 0.2 Pa for 6 h, normally increases VCAM-1, ICAM-1 and IL-8 expression in EC and allows for …binding of monocytes to EC. We found that overexpression of A20 in EC inhibits their normal expression of VCAM-1, ICAM-1 and IL-8 under low shear stress conditions. We also found that A20 inhibits IκBα degradation in EC following low shear stress exposure and that it attenuates the rolling and EC adhesive properties of shear-induced monocytes as compared with untransfected control EC. The results demonstrate that A20 overexpression in EC inhibits low shear flow-induced monocyte–EC interactions. These findings may be useful in the development of therapeutic agents aimed at treating chronic inflammatory diseases like atherosclerosis. Show more

Keywords: A20 gene, monocyte, atherosclerosis, VCAM-1, hemodynamics, IκBα

DOI: 10.3233/BIR-2009-0523

Citation: Biorheology, vol. 46, no. 1, pp. 21-30, 2009

Authors: Fam, H. | Kontopoulou, M. | Bryant, J.T.

Article Type: Research Article

Abstract: Rheological measurements were conducted on hyaluronic acid (HA)/bovine calf serum (BCS) solutions that can be used as analogues of synovial or periprosthetic fluid. The presence of HA affected profoundly the rheological properties of the solutions, with increased concentrations and higher molecular weight of HA leading to higher viscosities as well as more pronounced shear thinning in steady-shear flow. In dynamic oscillatory flow, the elastic character of the solutions became more pronounced and the cross-over frequency decreased upon increasing concentration and molecular weight of HA. The relevance of these results in the context of appropriate selection of a lubricating environment that …mimics physiological conditions is discussed. Show more

Keywords: Viscosity, viscoelasticity, arthritis, viscosupplementation

DOI: 10.3233/BIR-2009-0521

Citation: Biorheology, vol. 46, no. 1, pp. 31-43, 2009

Authors: Zeiter, Stephan | Lezuo, Patrick | Ito, Keita

Article Type: Research Article

Abstract: Bioactive factors, such as TGF β and BMP-2, as well as mechanical factors i.e. compressive loading and hydraulic pressure, have been shown to induce and/or modulate chondrogenesis of bone marrow derived mesenchymal stromal cells (BMSCs). Since these factors are intracellularly transduced through different mechanisms, it is hypothesized that TGF β, BMP-2 and hydraulic pressure may act synergistically on chondrogenic differentiation of BMSCs. Aggregates of bovine BMSC were cultured in the presence of 10 ng/ml TGF β1 , 50 ng/ml BMP-2 or both. Half of the samples were loaded for 4 hours per day with 0.5–3 MPa cyclic hydraulic pressure at …1 Hz. After 14 days of culture/loading, gene expression of chondrogenic genes was assessed. DNA as well as glycosaminoglycan (GAG) content of the pellets were analysed. Neither pressure nor BMP-2 had an influence on GAG/DNA content. However, cells responded to the presence of TGF β1 with an up-regulation of chondrogenic genes and GAG/DNA of the aggregates increased compared to controls demonstrating the cells ability to respond to external stimuli. The used concentrations of BMP-2 and parameters for pressure were neither able to induce nor modulate chondrogenesis of bovine BMSCs and thus no synergistic effects were observed. Show more

Keywords: Chondrogenesis, mechanobiology, bone marrow, stem cell, growth factors

DOI: 10.3233/BIR-2009-0520

Citation: Biorheology, vol. 46, no. 1, pp. 45-55, 2009

Authors: Braun, F.N.

Article Type: Short Communication

Abstract: The pathology of the disease cystic fibrosis is known to be associated very generally with ionic imbalance in the mucosal secretion which lines the respiratory tract, so-called airway surface liquid (ASL). The imbalance is caused by mutation of a transmembrane protein (CFTR) implicated in the control of ion traffic across the airway epithelium. It is feasible that CFTR malfunction undermines a putative phase-separated texture of healthy ASL which is apparent in electron microscopy images. A molecular statistical description of ASL is presented here with the aim of illustrating this hypothesis at the phenomenological level. The model predicts that a volume …criterion and a salt criterion must be met in order to achieve the phase-separated texture. These predictions help to rationalise the findings of clinical trials. In conjunction with further experimental investigation, molecular statistical approaches in this spirit have the potential to play a useful role in the drive towards treatment strategies. Show more

Keywords: Mucosal sol–gel transition, ion regulation, Donnan statistics, osmotic thermodynamics

DOI: 10.3233/BIR-2009-0524

Citation: Biorheology, vol. 46, no. 1, pp. 57-61, 2009

Authors: Grossin, Nicolas | Wautier, Marie-Paule | Wautier, Jean-Luc

Article Type: Review Article

Abstract: Red blood cell (RBC) adhesion to endothelium is increased in diabetes mellitus and is correlated with the severity of vascular complications. Microangiopathy is the most frequent complications in patients suffering from diabetes mellitus. Elevated glucose concentration increases the oxidation phenomenon and advanced glycation end product (AGE) formation. Plasma proteins, structural proteins and also RBC proteins can be glycated such as glycated hemoglobin and RBC membrane proteins. Interaction of plasmatic AGE or RBC bearing AGE with the receptor for AGE (RAGE) alters vascular function leading to a vascular hyperpermeability inflammatory reaction including oxidant stress and cytokine production. Reactive oxygen species (ROS) …react with nitric oxide (NO) limiting its vasodilatory effect and NO synthase function is altered. All these factors may be at the origin of high blood pressure which is deleterious for the eye and kidney vasculature. AGE can act directly on vascular function but also through RAGE. AGE binding to RAGE alters endothelial cell function stimulating NADPH oxidase and reactive oxygen species production. Limiting oxidation, reducing AGE formation or interaction with RAGE is achievable by drugs already used for hypertension or diabetes, but new treatment by NO modulators may limit the deleterious effect of RBC adhesion to endothelium. Show more

Keywords: Diabetic vasculopathy, nitric oxide, advanced glycation end products (AGE), reactive oxygen species, receptor for AGE (RAGE), red blood cells

DOI: 10.3233/BIR-2009-0519

Citation: Biorheology, vol. 46, no. 1, pp. 63-72, 2009

Article Type: Other

DOI: 10.3233/BIR-2009-0525

Citation: Biorheology, vol. 46, no. 1, pp. 73-73, 2009

Article Type: Other

DOI: 10.3233/BIR-2009-0526

Citation: Biorheology, vol. 46, no. 1, pp. 75-76, 2009