الفهرس 
Introduction and Aim of the workOnly 14 pages are availabe for public view
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Abstract
Atherosclerotic heart disease is a chronic life-threatening disease,
which is characterized by reduced blood supply to the heart as a result of
the accumulation of atheromatous plaques within the walls of the arteries
that supply the myocardium.
Progressive atherosclerosis in the coronary arteries may lead to
intimal thickening and eventual artery occlusion. Coronary artery
occlusion can cause acute myocardial ischemia as a result of reduced
oxygen supply or increased oxygen demand. Convincing evidence
indicates that atherosclerosis is associated with endothelial dysfunction at
the early stage of the disease process.
More recently, it has become clear that circulating endothelial
progenitor cells are an alternative mechanism for maintenance and repair
of the endothelium, these cells are recruited from the bone marrow,
circulate in the peripheral blood, and can differentiate into mature cells
with endothelial characteristics.
Postnatal vasculogenesis is the formation of new blood vessels
from bone marrow-derived endothelial progenitor cells (EPCs). This
process is regulated, in part, through chemokine signaling gradients that
guide these EPCs to areas of ischemia/injury.
Chemokines, a cytokine subset, are inflammatory mediators
specifically involved in trafficking of many different cell types including
immune cells and stem cells. Recent studies have shown that ionizing
radiation (IR) can affect CXC chemokine expression in human
fibroblasts.