Elevated monocytes in patients with critical limb ischemia diminish after bypass surgery.

Background: Mononuclear cells (MNC) increase neovascularization and ulcer healing after injection into an ischemic extremity. Circulating MNC are composed of lymphocytes (85%), monocytes (15%), and endothelial progenitor cells (EPC; 0.03%).

Limb ischemia after iliac ligation in aged mice stimulates angiogenesis without arteriogenesis.

Objective: Older patients are thought to tolerate acute ischemia more poorly than younger patients. Since aging may depress both angiogenesis and arteriogenesis, we determined the effects of age on both angiogenesis and arteriogenesis in a model of severe acute limb ischemia.

Methods: Young adult (3-months-old) and aged (18-months-old) C57BL/6 mice underwent right common iliac artery and vein ligation and transection.

Control of blood vessel identity: from embryo to adult.

Arteries and veins have been historically defined by the direction of blood flow and oxygen tension within the vessel, in addition to their functional, hemodynamic, and anatomical differences. It is now known that the molecular identity of these vessels is genetically predetermined, with specific molecular pathways activated during the development of arteries and veins. Eph-B4 is a determinant of venous differentiation and Ephrin-B2 is a determinant of arterial differentiation.

Endothelial progenitor cells: a primer for vascular surgeons.

Endothelial progenitor cells (EPCs) participate in vascular healing during both acute injury and chronic disease. The quantity and quality of circulating EPCs correlate inversely with the severity of vascular disease, such that reduced number and/or function of EPCs are significant independent risk factors for impaired healing capacity, dysfunctional endothelium, and progression of atherosclerosis and vascular disease. EPC therapy assists healing of cardiac and limb ischemia and has great potential for improving the quality of life and longevity of patients with severe cardiovascular and peripheral vascular disease who are not candidates for conventional revascularization procedures.