Estimation of Viscous Dissipative Stresses Induced by a Mechanical Heart Valve Using PIV Data

Li, Chi-Pei; Lo, Chi‐Wen; Lu, Po‐Chien

doi:10.1007/s10439-009-9867-y

Cited by 27 publications

(18 citation statements)

References 40 publications

(54 reference statements)

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“…These cells display structural and functional barrier properties owing to their high expression of tight junction proteins and high transendothelial resistance, thus resembling the BBB (Brown et al, 2007; Li et al, 2010). The MS1 microvascular endothelial cell line is derived from mouse pancreatic islets.…”

Section: Methodsmentioning

confidence: 99%

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

Kapitulnik¹,

Benaim²,

Sasson³

2012

Front. Pharmacol.

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Unconjugated bilirubin (UCB) is a neurotoxic degradation product of heme. Its toxic effects include induction of apoptosis, and ultimately neuronal cell death. However, at low concentrations, UCB is a potent antioxidant that may protect cells and tissues against oxidative stress by neutralizing toxic metabolites such as reactive oxygen species (ROS). High glucose levels (hyperglycemia) generate reactive metabolites. Endothelial cell dysfunction, an early vascular complication in diabetes, has been associated with hyperglycemia-induced oxidative stress. Both glucose and UCB are substrates for transport proteins in microvascular endothelial cells of the blood-brain barrier (BBB). In the current study we show that UCB (1–40 μM) induces apoptosis and reduces survival of bEnd3 cells, a mouse brain endothelial cell line which serves as an in vitro model of the BBB. These deleterious effects of UCB were enhanced in the presence of high glucose (25 mM) levels. Interestingly, the bEnd3 cells exhibited an increased sensitivity to the apoptotic effects of UCB when compared to the MS1 microcapillary endothelial cell line. MS1 cells originate from murine pancreatic islets of Langerhans, and are devoid of the barrier characteristics of BBB-derived endothelial cells. ROS production was increased in both bEnd3 and MS1 cells exposed to high glucose, as compared with cells exposed to normal (5.5 mM) glucose levels. While UCB (0.1–40 μM) did not alter ROS production in cells exposed to normal glucose, relatively low (“physiological”) UCB concentrations (0.1–5 μM) attenuated ROS generation in both cell lines exposed to high glucose levels. Most strikingly, higher UCB concentrations (20–40 μM) increased ROS generation in bEnd3 cells exposed to high glucose, but not in similarly treated MS1 cells. These results may be of critical importance for understanding the vulnerability of the BBB endothelium upon exposure to increasing UCB levels under hyperglycemic conditions.

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Section: Methodsmentioning

confidence: 99%

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

Kapitulnik¹,

Benaim²,

Sasson³

2012

Front. Pharmacol.

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“…They applied their model to prosthetic valve data by Liu et al [28] and investigated the relationship between true stress on blood cells and the measurable macroscopic stresses. Reynolds stresses are not small enough to directly capture the microscopic flow field in which hemolysis happens [27,[29][30][31]. Moreover, the stress distribution on the surface of the cell was affected by complicated local plasma flow around each cell.…”

Section: Introductionmentioning

confidence: 99%

Reynolds Stresses and Hemolysis in Turbulent Flow Examined by Threshold Analysis

Ozturk

O’Rear

Papavassiliou

2016

Fluids

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Abstract:Use of laminar flow-derived power law models to predict hemolysis with turbulence remains problematical. Flows in a Couette viscometer and a capillary tube have been simulated to investigate various combinations of Reynolds and/or viscous stresses power law models for hemolysis prediction. A finite volume-based computational method provided Reynolds and viscous stresses so that the effects of area-averaged and time-averaged Reynolds stresses, as well as total, viscous, and wall shear on hemolysis prediction could be assessed. The flow computations were conducted by using Reynolds-Averaged Navier-Stokes models of turbulence (k-ε and k-ω SST) to simulate four different experimental conditions in a capillary tube and seven experimental conditions in a Couette viscometer taken from the literature. Power law models were compared by calculating standard errors between measured hemolysis values and those derived from power law models with data from the simulations. In addition, suitability of Reynolds and viscous stresses was studied by threshold analysis. Results showed there was no evidence of a threshold value for hemolysis in terms of Reynolds and viscous stresses. Therefore, Reynolds and viscous stresses are not good predictors of hemolysis. Of power law models, the Zhang power law model (Artificial Organs, 2011, 35, 1180-1186 gives the lowest error overall for the hemolysis index and Reynolds stress (0.05570), while Giersiepen's model (The International journal of Artificial Organs, 1990, 13, 300-306) yields the highest (6.6658), and intermediate errors are found through use of Heuser's (Biorheology, 1980, 17, 17-24) model (0.3861) and Fraser's (Journal of Biomechanical Engineering, 2012, 134, 081002) model (0.3947).

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“…Nevertheless, for the most part, blood flow interacts with the valve when it is fully open, so even moderate thrombogenic conditions occurring during the main forward flow can potentially affect the patient's health. This is the reason why the main forward flow is still paid so much attention in recent experimental [25][26][27][28]31,32 and numerical 6,23,28,31,[33][34][35] investigation.…”

Section: Introductionmentioning

confidence: 99%

High-Resolution Measurement of the Unsteady Velocity Field to Evaluate Blood Damage Induced by a Mechanical Heart Valve

Bellofiore

Quinlan

2011

Ann Biomed Eng

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Estimation of Viscous Dissipative Stresses Induced by a Mechanical Heart Valve Using PIV Data

Cited by 27 publications

References 40 publications

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

Endothelial Cells Derived from the Blood-Brain Barrier and Islets of Langerhans Differ in their Response to the Effects of Bilirubin on Oxidative Stress Under Hyperglycemic Conditions

Reynolds Stresses and Hemolysis in Turbulent Flow Examined by Threshold Analysis

High-Resolution Measurement of the Unsteady Velocity Field to Evaluate Blood Damage Induced by a Mechanical Heart Valve

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