Identifying inflamed carotid plaques using in vivo USPIO-enhanced MR imaging to label plaque macrophages.

Background: Inflammation within atherosclerotic lesions contributes to plaque instability and vulnerability to rupture. We set out to evaluate the use of a macrophage labeling agent to identify carotid plaque inflammation by in vivo magnetic resonance imaging (MRI).

Methods And Results: Thirty patients with symptomatic severe carotid stenosis scheduled for carotid endarterectomy underwent multi-sequence MRI of the carotid bifurcation before and after injection of ultrasmall superparamagnetic particles of iron oxide (USPIOs).

MRI-derived measurements of fibrous-cap and lipid-core thickness: the potential for identifying vulnerable carotid plaques in vivo.

Vulnerable plaques have thin fibrous caps overlying large necrotic lipid cores. Recent studies have shown that high-resolution MR imaging can identify these components. We set out to determine whether in vivo high-resolution MRI could quantify this aspect of the vulnerable plaque.

In vivo detection of macrophages in human carotid atheroma: temporal dependence of ultrasmall superparamagnetic particles of iron oxide-enhanced MRI.

Unlabelled: Background- It has been suggested that inflammatory cells within vulnerable plaques may be visualized by superparamagnetic iron oxide particle-enhanced MRI. The purpose of this study was to determine the time course for macrophage visualization with in vivo contrast-enhanced MRI using an ultrasmall superparamagnetic iron oxide (USPIO) agent in symptomatic human carotid disease.

Methods: Eight patients scheduled for carotid endarterectomy underwent multisequence MRI of the carotid bifurcation before and 24, 36, 48, and 72 hours after Sinerem (2.

Hypoxic induction of cox-2 regulates proliferation of human pulmonary artery smooth muscle cells.

Chronic hypoxia-induced pulmonary hypertension results partly from proliferation of smooth muscle cells in small peripheral pulmonary arteries. Therefore, we examined the effect of hypoxia on growth of pulmonary artery smooth muscle cells (PASMCs) from human distal pulmonary arteries. Initial studies identified that serum-induced proliferation of explant-derived PASMCs was inhibited under hypoxic conditions (3-4 kPa in medium).

Histopathology of cardiac xenograft rejection in the pig-to-baboon model.

Background: The use of pig organs transgenic for human decay accelerating factor (hDAF) has largely overcome the problems of hyperacute rejection. With improved immunosuppressive protocols, life supporting grafts are showing greater survival times bringing the possibility of clinical xenotransplantation closer. Examination of the histopathology of the rejection process provides insight into the underlying mechanism and may suggest ways in which new immunosuppressive strategies should be directed.

Posttransplant lymphoproliferative disorder associated with primate gamma-herpesvirus in cynomolgus monkeys used in pig-to-primate renal xenotransplantation and primate renal allotransplantation.

Background: A series of immunosuppressed cynomolgus monkeys were used in porcine-to-primate and primate-to-primate renal transplantation. In a number of animals nodal and extranodal lymphomas as well as areas of lymphoid hyperplasia in multiple organs (posttransplant lymphoproliferative disorder, PTLD) were recorded.

Methods: PTLD was characterized with respect to manifestation sites, histopathology, immunophenotype, and association with primate Epstein Barr-like Virus by in situ hybridization and quantitative polymerase chain reaction.