Effects of polycythemia on systemic endothelial function in chronic hypoxic lung disease.

Chronic obstructive pulmonary disease (COPD) is a major risk factor for cardiovascular disease. Polycythemia, a common complication of hypoxic COPD, may affect systemic vascular function by altering blood viscosity, vessel wall shear stress (WSS), and endothelium-derived nitric oxide (NO) release. Here, we evaluated the effects of hypoxia-related polycythemia on systemic endothelial function in patients with COPD.

[Whole blood viscosity measurement in acute myocardial infarction: feasibility and significance].

Thrombolytic agents and new antiplatelet drugs used in acute myocardial infarction (AMI) could change whole blood viscosity. The aim of this pilot trial is to compare blood viscosity at four shear rate levels among three groups of patients: AMI receiving thrombolysis with alteplase (n: 10), AMI eligible for primary angioplasty with abciximab (n: 10), healthy volunteers (n: 10). Viscosity measurement was obtained in 30 minutes with a Couette hemoviscosimeter.

Endothelial dysfunction in patients with sickle cell disease is related to selective impairment of shear stress-mediated vasodilation.

Interactions between the endothelium and erythrocytes may contribute to the vascular complications of sickle cell disease (SCD). Endothelium-derived nitric oxide (NO) plays a major role in the regulation of vasomotor tone in response to wall shear stress (WSS) variations and pharmacologic stimuli. However, little is known about endothelial NO production in patients with steady-state SCD.

[A study of leukocyte chemotaxis in a glass micropipette].

Chemotaxis, the directional locomotion of a cell toward a source of a chemical gradient, is an important phenomenon occurring for mobilizing immune cells at sites of infection and injury. This phenomenon has been simulated in analyzing the movement in vitro of a chemoattracted cell inside a glass micropipette. A microneedle filled with fMLP, N-formyl-methionyl-leucyl-phenylalanine, at a concentration of 9.

Effects of two low-osmolar contrast media, ioxaglate and iopamidol, on erythrocyte membrane elasticity.

Rationale And Objectives: The effect of ioxaglate and iopamidol, two recently developed low-osmolality contrast media, on the shear elasticity of erythrocyte membranes was studied at an iodine concentration of 300 mg/mL and at a 20% volume concentration and compared with that obtained for control solutions matched in osmolality.

Methods: The authors used a micromanipulation technique, which consists of visualizing deformations of individual erythrocytes when gently aspirated into the tip of a glass micropipette by an accurately controlled pressure. An erythrocyte membrane shear elasticity modulus mu was then deduced.