Implementation of a Power Down Initiative in 34 Operating Rooms.

Operating rooms (ORs) use energy-intensive equipment such as anesthesia gas machines, patient monitors, and lights. They are major contributors to an institution's carbon footprint; yet ORs are unoccupied 40% of the time. Implementing an initiative to power down electrical devices can reduce energy consumption, equipment failure, and financial outlay.

Vascular endothelial cell morphology and alignment regulate VEGF-induced endothelial nitric oxide synthase activation.

Nitric oxide (NO) production by endothelial nitric oxide synthase (eNOS) inhibits platelet and leukocyte adhesion while promoting vasorelaxation in smooth muscle cells. Dysfunctional regulation of eNOS is a hallmark of various vascular pathologies, notably atherosclerosis, often associated with areas of low shear stress on endothelial cells (ECs). While the link between EC morphology and local hemodynamics is acknowledged, the specific impact of EC morphology on eNOS regulation remains unclear.

Learning Environments and Evidence-Based Practices in Bioengineering and Biomedical Engineering.

This paper provides a synopsis of discussions related to the Learning Environments track of the Fourth BME Education Summit held at Case Western Reserve University in Cleveland, Ohio in May 2019. This summit was organized by the Council of Chairs of Bioengineering and Biomedical Engineering, and participants included over 300 faculty members from 100+ accredited undergraduate programs. The Learning Environments track had six interactive workshops that provided facilitated discussion and provide recommendations in the areas of: (1) Authentic project/problem identification in clinical, industrial, and global settings, (2) Experiential problem/project-based learning within courses, (3) Experiential learning in co-curricular learning settings, (4) Team-based learning, (5) Teaching to reach a diverse classroom, and (6) innovative platforms and pedagogy.

Coordinated regulation of endothelial calcium signaling and shear stress-induced nitric oxide production by PKCβ and PKCη.

Background: Protein Kinase C (PKC) is a promiscuous serine/threonine kinase regulating vasodilatory responses in vascular endothelial cells. Calcium-dependent PKCbeta (PKCβ) and calcium-independent PKCeta (PKCη) have both been implicated in the regulation and dysfunction of endothelial responses to shear stress and agonists.

Objective: We hypothesized that PKCβ and PKCη differentially modulate shear stress-induced nitric oxide (NO) production by regulating the transduced calcium signals and the resultant eNOS activation.

TRPC channel-derived calcium fluxes differentially regulate ATP and flow-induced activation of eNOS.

Endothelial dysfunction, characterised by impaired nitric oxide (NO) bioavailability, arises in response to a variety of cardiovascular risk factors and precedes atherosclerosis. NO is produced by tight regulation of endothelial nitric oxide synthase (eNOS) activity in response to vasodilatory stimuli. This regulation of eNOS is mediated in part by store-operated calcium entry (SOCE).

Effect of spatial heterogeneity and colocalization of eNOS and capacitative calcium entry channels on shear stress-induced NO production by endothelial cells: A modeling approach.

Introduction: Colocalization of endothelial nitric oxide synthase (eNOS) and capacitative Ca entry (CCE) channels in microdomains such as cavaeolae in endothelial cells (ECs) has been shown to significantly affect intracellular Ca dynamics and NO production, but the effect has not been well quantified.

Methods: We developed a two-dimensional continuum model of an EC integrating shear stress-mediated ATP production, intracellular Ca mobilization, and eNOS activation to investigate the effects of spatial colocalization of plasma membrane eNOS and CCE channels on Ca dynamics and NO production in response to flow-induced shear stress. Our model examines the hypothesis that subcellular colocalization of cellular components can be critical for optimal coupling of NO production to blood flow.

A dynamic computational network model for the role of nitric oxide and the myogenic response in microvascular flow regulation.

Objectives: The effect of NO on smooth muscle cell contractility is crucial in regulating vascular tone, blood flow, and O delivery. Quantitative predictions for interactions between the NO production rate and the myogenic response for microcirculatory blood vessels are lacking.

Methods: We developed a computational model of a branching microcirculatory network with four representative classes of resistance vessels to predict the effect of endothelium-derived NO on the microvascular pressure-flow response.

Nitrite-Mediated Hypoxic Vasodilation Predicted from Mathematical Modeling and Quantified from Studies in Rat Mesentery.

Nitric oxide (NO) generated from nitrite through nitrite reductase activity in red blood cells has been proposed to play a major role in hypoxic vasodilation. However, we have previously predicted from mathematical modeling that much more NO can be derived from tissue nitrite reductase activity than from red blood cell nitrite reductase activity. Evidence in the literature suggests that tissue nitrite reductase activity is associated with xanthine oxidoreductase (XOR) and/or aldehyde oxidoreductase (AOR).

Nitric oxide release by deoxymyoglobin nitrite reduction during cardiac ischemia: A mathematical model.

Interactions between cardiac myoglobin (Mb), nitrite, and nitric oxide (NO) are vital in regulating O storage, transport, and NO homeostasis. Production of NO through the reduction of endogenous myocardial nitrite by deoxygenated myoglobin has been shown to significantly reduce myocardial infarction damage and ischemic injury. We developed a mathematical model for a cardiac arteriole and surrounding myocardium to examine the hypothesis that myoglobin switches functions from being a strong NO scavenger to an NO producer via the deoxymyoglobin nitrite reductase pathway.

Cholesterol Enrichment Impairs Capacitative Calcium Entry, eNOS Phosphorylation & Shear Stress-Induced NO Production.

Endothelial dysfunction, characterized by decreased production or availability of nitric oxide (NO), is widely believed to be the hallmark of early-stage atherosclerosis. In addition, hypercholesterolemia is considered a major risk factor for development of atherosclerosis and is associated with impaired flow-induced dilation. However, the mechanism by which elevated cholesterol levels leads to decreased production of NO is unclear.

A mathematical model for the role of NO in enhancing nitric oxide bioavailability following nitrite infusion.

Nitrite infusion into the bloodstream has been shown to elicit vasodilation and protect against ischemia-reperfusion injury through nitric oxide (NO) release in hypoxic conditions. However, the mechanism by which nitrite-derived NO escapes scavenging by hemoglobin in the erythrocyte has not been fully elucidated, owing in part to the difficulty in measuring the reactions and transport on NO in vivo. We developed a mathematical model for an arteriole and surrounding tissue to examine the hypothesis that dinitrogen trioxide (NO) acts as a stable intermediate for preserving NO.

Mathematical model for shear stress dependent NO and adenine nucleotide production from endothelial cells.

We developed a mass transport model for a parallel-plate flow chamber apparatus to predict the concentrations of nitric oxide (NO) and adenine nucleotides (ATP, ADP) produced by cultured endothelial cells (ECs) and investigated how the net rates of production, degradation, and mass transport for these three chemical species vary with changes in wall shear stress (τw). These simulations provide an improved understanding of experimental results obtained with parallel-plate flow chambers and allows quantitative analysis of the relationship between τw, adenine nucleotide concentrations, and NO produced by ECs. Experimental data obtained after altering ATP and ADP concentrations with apyrase were analyzed to quantify changes in the rate of NO production (RNO).

An in vitro model of the tumor-lymphatic microenvironment with simultaneous transendothelial and luminal flows reveals mechanisms of flow enhanced invasion.

The most common cancers, including breast and skin, disseminate initially through the lymphatic system, yet the mechanisms by which tumor cells home towards, enter and interact with the lymphatic endothelium remain poorly understood. Transmural and luminal flows are important biophysical cues of the lymphatic microenvironment that can affect adhesion molecules, growth factors and chemokine expression as well as matrix remodeling, among others. Although microfluidic models are suitable for in vitro reconstruction of highly complex biological systems, the difficult assembly and operation of these systems often only allows a limited throughput.

Emotional Eating, Nonpurge Binge Eating, and Self-Efficacy in Healthy Perimenopausal Women.

Purpose: To examine the relationships among nonpurge binge eating, emotional eating, and diet-related self-efficacy in perimenopausal women, a population at risk for weight gain.

Design Of Study: Descriptive correlational study.

Method: Secondary analysis of baseline data for a weight gain prevention intervention, Mindful Restaurant Eating, with a sample of healthy perimenopausal women (n = 43).

Shear stress-induced NO production is dependent on ATP autocrine signaling and capacitative calcium entry.

Flow-induced production of nitric oxide (NO) by endothelial cells plays a fundamental role in vascular homeostasis. However, the mechanisms by which shear stress activates NO production remain unclear due in part to limitations in measuring NO, especially under flow conditions. Shear stress elicits the release of ATP, but the relative contribution of autocrine stimulation by ATP to flow-induced NO production has not been established.

Change to a standardized airway clearance protocol for children with bronchiolitis leads to improved care.

Nurses at a pediatric hospital identified the liberal utilization of deep nasopharyngeal (NP) suction as the primary airway clearance modality in young children with bronchiolitis. This invasive practice lacked supporting evidence and a standardized approach. Nurses created an interdisciplinary team to develop a less invasive airway clearance protocol.

Antimicrobial efficacy and wound-healing property of a topical ointment containing nitric-oxide-loaded zeolites.

Topical delivery of nitric oxide (NO) through a wound dressing has the potential to reduce wound infections and improve healing of acute and chronic wounds. This study characterized the antibacterial efficacy of an ointment containing NO-loaded, zinc-exchanged zeolite A that releases NO upon contact with water. The release rate of NO from the ointment was measured using a chemiluminescence detection system.

Preventing neuronal damage and inflammation in vivo during cortical microelectrode implantation through the use of poloxamer P-188.

Objective: The aim of this study was to test the efficacy of Poloxamer P188 to reduce cell death and immune response associated with mechanical trauma to cells during implantation of a chronic recording electrode.

Approach: Ceramic multi-site recording electrodes were implanted bilaterally into 15 adult male Long-Evans rats. One of each pair was randomly assigned to receive a coating of Poloxamer while the other was treated with saline.

Fractional-order time series models for extracting the haemodynamic response from functional magnetic resonance imaging data.

The postprocessing of functional magnetic resonance imaging (fMRI) data to study the brain functions deals mainly with two objectives: signal detection and extraction of the haemodynamic response. Signal detection consists of exploring and detecting those areas of the brain that are triggered due to an external stimulus. Extraction of the haemodynamic response deals with describing and measuring the physiological process of activated regions in the brain due to stimulus.

Porcine intact and wounded skin responses to atmospheric nonthermal plasma.

Thermal plasma is a valued tool in surgery for its coagulative and ablative properties. We suggested through in vitro studies that nonthermal plasma can sterilize tissues, inactive pathogens, promote coagulation, and potentiate wound healing. The present research was undertaken to study acute toxicity in porcine skin tissues.

Force dependent internalization of magnetic nanoparticles results in highly loaded endothelial cells for use as potential therapy delivery vectors.

Purpose: To investigate the kinetics, mechanism and extent of MNP loading into endothelial cells and the effect of this loading on cell function.

Methods: MNP uptake was examined under field on/off conditions, utilizing varying magnetite concentration MNPs. MNP-loaded cell viability and functional integrity was assessed using metabolic respiration, cell proliferation and migration assays.

Nitric oxide signaling in the microcirculation.

Several apparent paradoxes are evident when one compares mathematical predictions from models of nitric oxide (NO) diffusion and convection in vasculature structures with experimental measurements of NO (or related metabolites) in animal and human studies. Values for NO predicted from mathematical models are generally much lower than in vivo NO values reported in the literature for experiments, specifically with NO microelectrodes positioned at perivascular locations next to different sizes of blood vessels in the microcirculation and NO electrodes inserted into a wide range of tissues supplied by the microcirculation of each specific organ system under investigation. There continues to be uncertainty about the roles of NO scavenging by hemoglobin versus a storage function that may conserve NO, and other signaling targets for NO need to be considered.

Microfluidic Device for Capture and Isolation of Single Cells.

We describe a microfluidic device capable of trapping, isolating, and lysing individual cells in parallel using dielectrophoretic forces and a system of PDMS channels and valves. The device consists of a glass substrate patterned with electrodes and two PDMS layers comprising of the microfluidic channels and valve control channels. Individual cells are captured by positive dielectrophoresis using the microfabricated electrode pairs.

Glycated collagen alters endothelial cell actin alignment and nitric oxide release in response to fluid shear stress.

People with diabetes suffer from early accelerated atherosclerosis, which contributes to morbidity and mortality from myocardial infarction, stroke, and peripheral vascular disease. Atherosclerosis is thought to initiate at sites of endothelial cell injury. Hyperglycemia, a hallmark of diabetes, leads to non-enzymatic glycosylation (or glycation) of extracellular matrix proteins.

Modeling O₂-dependent effects of nitrite reductase activity in blood and tissue on coupled NO and O₂ transport around arterioles.

Recent evidence in the literature suggests that tissues play a greater role than blood in reducing nitrite to NO under ischemic or hypoxic conditions. Our previous mathematical model for coupled NO and O(2) transport around an arteriole, modified to include superoxide generation from dysfunctional endothelium, was developed further to include nitrite reductase activity in blood and tissue. Steady-state radial and axial NO and pO(2) profiles in the arteriole and surrounding tissue were simulated for different blood flow rates and arterial blood pO(2) values.