The role of platelet-endothelial cell adhesion molecule-1 in atheroma formation varies depending on the site-specific hemodynamic environment.

Objective: Polymorphisms in the platelet-endothelial cell adhesion molecule (PECAM-1)-1 gene are linked to increased risk of coronary artery disease. Because PECAM-1 has been demonstrated to form a mechanosensory complex that can modulate inflammatory responses in murine arterial endothelial cells, we hypothesized that PECAM-1 contributes to atherogenesis in a shear-dependent and site-specific manner.

Approach And Results: ApoE(-/-) mice that were wild-type, heterozygous, or deficient in PECAM-1 were placed on a high-fat diet.

Subharmonic contrast intravascular ultrasound for vasa vasorum imaging.

The feasibility of subharmonic contrast intravascular ultrasound (IVUS) imaging was investigated using a prototype nonlinear IVUS system and the commercial contrast agent Definity . The system employed a mechanically scanned commercial catheter with a custom transducer element fabricated to have sensitivity at both 15 and 30 MHz. Experiments were conducted at a fundamental frequency of 30 MHz (F30; 25% bandwidth), with on-axis pressures ranging from 0.

Contrast harmonic intravascular ultrasound: a feasibility study for vasa vasorum imaging.

Objective: We sought to investigate feasibility of vasa vasorum imaging using the novel technique of contrast harmonic intravascular ultrasound.

Methods: Prototype intravascular ultrasound (IVUS) instrumentation was developed for the sensitive detection of micro-bubble contrast agents. The technique, "harmonic" imaging, involves transmitting ultrasound at 20 MHz (fundamental) and detecting contrast signals at 40 MHz (second harmonic).

Shear stress biology of the endothelium.

The relationships between blood flow, mechanotransduction, and the localization of arterial lesions can now be advanced by the incorporation of new technologies and the refinement of existing methods in imaging modalities, computational modeling, fluid dynamics, and high throughput genomics and proteomics. When combined with traditional cell and molecular technologies, a powerful palette of investigative approaches is available to address shear stress biology of the endothelium at levels extending from nanoscale subcellular detailed mechanistic responses through to higher organizational levels of regional endothelial phenotypes and heterogeneous vascular beds.