الفهرس 
IONIZING RADIATIONOnly 14 pages are availabe for public view
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Abstract
T
he advent of complex and prolonged coronary interventional procedures has increased levels of radiation exposure among cardiac catheterization working staff, who due to close contact with patients, have the highest potential risk of receiving a long-term exposure to low level ionizing radiation that greatly increases the risk of health hazards. Although a causative link has long been established between exposure to ionizing radiation and the risk of mortality from many forms of cancer, recently there is emerging evidence of excess risk of cardiovascular disease at much lower radiation doses and occurring a long time after radiation exposure and in various occupationally-exposed groups.
The aim of this work was to evaluate the dose of radiation exposure to cardiac catheterization participating in cardiac catheterization procedures in a three busy teaching hospitals. Individual annual collective dose information was measured by thermoluminscent personal dosimeters (TLD) for those technicians and found to be ranging between 4.6 and 7.8 mSv/y.
Recent studies have identified populations of multipotent progenitor cells, nerve progenitor cells (NPC) adult stem cells-called endothelial progenitor cells (EPCs) that circulate in peripheral blood. EPCs and NPC counteract ongoing risk factor-induced endothelial cell injury and nerve cell injury respectively, and in response to acute hypoxia are mobilized from bone marrow (BM) to peripheral blood and participate in endothelial and nerve cell repair and regeneration and also in tissue neovascularization. The chemokine for EPCs is termed Stromal Derived growth factor (SDF-1), while the chemokine for NPCs is nerve growth factor (NGF).
Until now, no study has investigated EPCs, NPC numbers nor SDF-1 and NGF levels in the blood of cardiac catheterization technicians exposed to radiation. Thus the aim of the present study is to investigate EPCs and NECs in circulating blood and plasma SDF-1 and NGF in the peripheral blood of cardiac catheterization staff and find out if such cells are mobilized due to radiation exposure. EPCs surface markers were identified as the CD34, CD133 and kinase domain receptors (KDR). NECs was measured in terms of Nestin and CD45. Lipid peroxidation as a marker for endothelial damage and amyloid beta peptide as a marker of nerve tissue damage were also assayed.
Venous blood samples were obtained from 70 cardiac catheterization physician, technicians and nurses exposed to x-ray during fluoroscopy procedures at Al Azhar University and Ain Shams Universities and Heart National Institute in Embaba. The control group involved 30 persons not exposed to ionizing radiation.
Results showed that plasma lipid peroxidation (8.5 ± 3.1 vs. 3.8 ± 1.5) was significantly higher among CC staff compared to controls, AB42 (12.4 ± 4.5 vs. 14.7 ± 4.7) was non-significantly higher among CC staff compared to controls SDF-1α (533.8 ± 70.9 vs. 494 ± 38.7) was significantly higher among cardiac catheterization staff compared to controls respectively. Similarly, EPCs: CD34 (50.8 ± 7.5 vs. 44 ± 8.3), CD133 (52.25 ± 9.2 vs. 45.1 ± 9.4) KDR (44.6 ± 11.6 vs. 38.8 ± 7.4) were also significantly higher among cardiac catheterization staff compared to the controls.
NGF was significantly higher among CC staff compared to controls (116.54 ± 14.4 vs. 108.8 ± 10.3). NECs measured in terms of Nestin (12.5 ± 2.7 vs. 9.2 ± 3) and CD45 (49.1 ± 10.5 vs. 42.7 ± 13) were also significantly higher among C staff compared to controls.
It is found that among cardiac catheterization staff, the numbers of circulating progenitor cells had increased and accordingly there was an increased capacity for tissue repair. In conclusion, the present work shows that exposure to radiation, well within permissible levels, stimulates regenerative processes as indicated by the increase in EPCs and NEC conclusion mbers together with SDF-1 and NGF plasma levels.